get rid of global "struct bb_applet *current_applet"
[oweals/busybox.git] / shell / ash.c
index 0704353f5289822db3cfcd3745c48822fb2973b9..af96c4d1da2365077ce4fd4441db598219c9a07d 100644 (file)
@@ -31,7 +31,6 @@
  *
  */
 
-
 /*
  * The follow should be set to reflect the type of system you have:
  *      JOBS -> 1 if you have Berkeley job control, 0 otherwise.
  * a quit signal will generate a core dump.
  */
 #define DEBUG 0
-
-
 #define IFS_BROKEN
-
 #define PROFILE 0
-
-#include "busybox.h"
+#if ENABLE_ASH_JOB_CONTROL
+#define JOBS 1
+#else
+#define JOBS 0
+#endif
 
 #if DEBUG
 #define _GNU_SOURCE
 #endif
-
-#include <sys/types.h>
-#include <sys/ioctl.h>
-#include <sys/param.h>
-#include <sys/resource.h>
-#include <sys/stat.h>
-#include <sys/wait.h>
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include <stdarg.h>
-#include <stddef.h>
-#include <assert.h>
-#include <ctype.h>
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <limits.h>
+#include "busybox.h" /* for struct bb_applet */
 #include <paths.h>
 #include <setjmp.h>
-#include <signal.h>
-/*#include <stdint.h>*/
-#include <time.h>
 #include <fnmatch.h>
-
-#ifdef CONFIG_ASH_JOB_CONTROL
-#define JOBS 1
-#else
-#undef JOBS
-#endif
-
-#if JOBS || defined(CONFIG_ASH_READ_NCHARS)
+#if JOBS || ENABLE_ASH_READ_NCHARS
 #include <termios.h>
 #endif
-
-#include "cmdedit.h"
-
-#ifdef __GLIBC__
-/* glibc sucks */
-static int *dash_errno;
-#undef errno
-#define errno (*dash_errno)
-#endif
+extern char **environ;
 
 #if defined(__uClinux__)
 #error "Do not even bother, ash will not run on uClinux"
 #endif
 
-#if DEBUG
-#define _DIAGASSERT(assert_expr) assert(assert_expr)
-#else
-#define _DIAGASSERT(assert_expr)
-#endif
 
+/* ============ Misc helpers */
 
-#ifdef CONFIG_ASH_ALIAS
-/*      alias.h       */
+#define xbarrier() do { __asm__ __volatile__ ("": : :"memory"); } while (0)
 
-#define ALIASINUSE      1
-#define ALIASDEAD       2
+/* C99 say: "char" declaration may be signed or unsigned default */
+#define signed_char2int(sc) ((int)((signed char)sc))
 
-struct alias {
-       struct alias *next;
-       char *name;
-       char *val;
-       int flag;
-};
 
-static struct alias *lookupalias(const char *, int);
-static int aliascmd(int, char **);
-static int unaliascmd(int, char **);
-static void rmaliases(void);
-static int unalias(const char *);
-static void printalias(const struct alias *);
+/* ============ Shell options */
+
+static const char *const optletters_optnames[] = {
+       "e"   "errexit",
+       "f"   "noglob",
+       "I"   "ignoreeof",
+       "i"   "interactive",
+       "m"   "monitor",
+       "n"   "noexec",
+       "s"   "stdin",
+       "x"   "xtrace",
+       "v"   "verbose",
+       "C"   "noclobber",
+       "a"   "allexport",
+       "b"   "notify",
+       "u"   "nounset",
+       "\0"  "vi"
+#if DEBUG
+       ,"\0"  "nolog"
+       ,"\0"  "debug"
 #endif
+};
+
+#define optletters(n) optletters_optnames[(n)][0]
+#define optnames(n) (&optletters_optnames[(n)][1])
 
-/*      cd.h  */
+enum { NOPTS = ARRAY_SIZE(optletters_optnames) };
 
+static char optlist[NOPTS] ALIGN1;
 
-static void    setpwd(const char *, int);
+#define eflag optlist[0]
+#define fflag optlist[1]
+#define Iflag optlist[2]
+#define iflag optlist[3]
+#define mflag optlist[4]
+#define nflag optlist[5]
+#define sflag optlist[6]
+#define xflag optlist[7]
+#define vflag optlist[8]
+#define Cflag optlist[9]
+#define aflag optlist[10]
+#define bflag optlist[11]
+#define uflag optlist[12]
+#define viflag optlist[13]
+#if DEBUG
+#define nolog optlist[14]
+#define debug optlist[15]
+#endif
 
-/*      error.h      */
 
+/* ============ Misc data */
 
-/*
- * Types of operations (passed to the errmsg routine).
- */
+static char nullstr[1] ALIGN1;  /* zero length string */
+static const char homestr[] ALIGN1 = "HOME";
+static const char snlfmt[] ALIGN1 = "%s\n";
+static const char illnum[] ALIGN1 = "Illegal number: %s";
 
+static char *minusc;  /* argument to -c option */
 
-static const char not_found_msg[] = "%s: not found";
+/* pid of main shell */
+static int rootpid;
+/* shell level: 0 for the main shell, 1 for its children, and so on */
+static int shlvl;
+#define rootshell (!shlvl)
+/* trap handler commands */
+static char *trap[NSIG];
+static smallint isloginsh;
+/* current value of signal */
+static char sigmode[NSIG - 1];
+/* indicates specified signal received */
+static char gotsig[NSIG - 1];
+static char *arg0; /* value of $0 */
 
 
-#define E_OPEN  "No such file"          /* opening a file */
-#define E_CREAT "Directory nonexistent" /* creating a file */
-#define E_EXEC  not_found_msg+4         /* executing a program */
+/* ============ Interrupts / exceptions */
 
 /*
  * We enclose jmp_buf in a structure so that we can declare pointers to
@@ -162,16 +160,11 @@ static const char not_found_msg[] = "%s: not found";
  * to an inner scope, set handler to point to a jmploc structure for the
  * inner scope, and restore handler on exit from the scope.
  */
-
 struct jmploc {
        jmp_buf loc;
 };
-
-static struct jmploc *handler;
+static struct jmploc *exception_handler;
 static int exception;
-static volatile int suppressint;
-static volatile sig_atomic_t intpending;
-
 /* exceptions */
 #define EXINT 0         /* SIGINT received */
 #define EXERROR 1       /* a generic error */
@@ -179,12 +172,24 @@ static volatile sig_atomic_t intpending;
 #define EXEXEC 3        /* command execution failed */
 #define EXEXIT 4        /* exit the shell */
 #define EXSIG 5         /* trapped signal in wait(1) */
-
-
+static volatile int suppressint;
+static volatile sig_atomic_t intpending;
 /* do we generate EXSIG events */
 static int exsig;
 /* last pending signal */
-static volatile sig_atomic_t pendingsigs;
+static volatile sig_atomic_t pendingsig;
+
+/*
+ * Sigmode records the current value of the signal handlers for the various
+ * modes.  A value of zero means that the current handler is not known.
+ * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
+ */
+
+#define S_DFL 1                 /* default signal handling (SIG_DFL) */
+#define S_CATCH 2               /* signal is caught */
+#define S_IGN 3                 /* signal is ignored (SIG_IGN) */
+#define S_HARD_IGN 4            /* signal is ignored permenantly */
+#define S_RESET 5               /* temporary - to reset a hard ignored sig */
 
 /*
  * These macros allow the user to suspend the handling of interrupt signals
@@ -192,291 +197,229 @@ static volatile sig_atomic_t pendingsigs;
  * much more efficient and portable.  (But hacking the kernel is so much
  * more fun than worrying about efficiency and portability. :-))
  */
-
-#define xbarrier() ({ __asm__ __volatile__ ("": : :"memory"); })
-#define INTOFF \
-       ({ \
+#define INT_OFF \
+       do { \
                suppressint++; \
                xbarrier(); \
-               0; \
-       })
-#define SAVEINT(v) ((v) = suppressint)
-#define RESTOREINT(v) \
-       ({ \
-               xbarrier(); \
-               if ((suppressint = (v)) == 0 && intpending) onint(); \
-               0; \
-       })
-#define EXSIGON() \
-       ({ \
-               exsig++; \
-               xbarrier(); \
-               if (pendingsigs) \
-                       exraise(EXSIG); \
-               0; \
-       })
-/* EXSIG is turned off by evalbltin(). */
+       } while (0)
 
+/*
+ * Called to raise an exception.  Since C doesn't include exceptions, we
+ * just do a longjmp to the exception handler.  The type of exception is
+ * stored in the global variable "exception".
+ */
+static void raise_exception(int) ATTRIBUTE_NORETURN;
+static void
+raise_exception(int e)
+{
+#if DEBUG
+       if (exception_handler == NULL)
+               abort();
+#endif
+       INT_OFF;
+       exception = e;
+       longjmp(exception_handler->loc, 1);
+}
 
-static void exraise(int) ATTRIBUTE_NORETURN;
-static void onint(void) ATTRIBUTE_NORETURN;
+/*
+ * Called from trap.c when a SIGINT is received.  (If the user specifies
+ * that SIGINT is to be trapped or ignored using the trap builtin, then
+ * this routine is not called.)  Suppressint is nonzero when interrupts
+ * are held using the INT_OFF macro.  (The test for iflag is just
+ * defensive programming.)
+ */
+static void raise_interrupt(void) ATTRIBUTE_NORETURN;
+static void
+raise_interrupt(void)
+{
+       int i;
+       sigset_t mask;
 
-static void sh_error(const char *, ...) ATTRIBUTE_NORETURN;
-static void exerror(int, const char *, ...) ATTRIBUTE_NORETURN;
+       intpending = 0;
+       /* Signal is not automatically re-enabled after it is raised,
+        * do it ourself */
+       sigemptyset(&mask);
+       sigprocmask(SIG_SETMASK, &mask, 0);
+       /* pendingsig = 0; - now done in onsig() */
 
-static void sh_warnx(const char *, ...);
+       i = EXSIG;
+       if (gotsig[SIGINT - 1] && !trap[SIGINT]) {
+               if (!(rootshell && iflag)) {
+                       signal(SIGINT, SIG_DFL);
+                       raise(SIGINT);
+               }
+               i = EXINT;
+       }
+       raise_exception(i);
+       /* NOTREACHED */
+}
 
-#ifdef CONFIG_ASH_OPTIMIZE_FOR_SIZE
+#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
 static void
-inton(void) {
+int_on(void)
+{
        if (--suppressint == 0 && intpending) {
-               onint();
+               raise_interrupt();
        }
 }
-#define INTON inton()
-static void forceinton(void)
+#define INT_ON int_on()
+static void
+force_int_on(void)
 {
        suppressint = 0;
        if (intpending)
-               onint();
+               raise_interrupt();
 }
-#define FORCEINTON forceinton()
+#define FORCE_INT_ON force_int_on()
 #else
-#define INTON \
-       ({ \
+#define INT_ON \
+       do { \
                xbarrier(); \
-               if (--suppressint == 0 && intpending) onint(); \
-               0; \
-       })
-#define FORCEINTON \
-       ({ \
+               if (--suppressint == 0 && intpending) \
+                       raise_interrupt(); \
+       } while (0)
+#define FORCE_INT_ON \
+       do { \
                xbarrier(); \
                suppressint = 0; \
-               if (intpending) onint(); \
-               0; \
-       })
-#endif /* CONFIG_ASH_OPTIMIZE_FOR_SIZE */
-
-/*      expand.h     */
+               if (intpending) \
+                       raise_interrupt(); \
+       } while (0)
+#endif /* ASH_OPTIMIZE_FOR_SIZE */
 
-struct strlist {
-       struct strlist *next;
-       char *text;
-};
+#define SAVE_INT(v) ((v) = suppressint)
 
+#define RESTORE_INT(v) \
+       do { \
+               xbarrier(); \
+               suppressint = (v); \
+               if (suppressint == 0 && intpending) \
+                       raise_interrupt(); \
+       } while (0)
 
-struct arglist {
-       struct strlist *list;
-       struct strlist **lastp;
-};
+#define EXSIGON \
+       do { \
+               exsig++; \
+               xbarrier(); \
+               if (pendingsig) \
+                       raise_exception(EXSIG); \
+       } while (0)
+/* EXSIG is turned off by evalbltin(). */
 
 /*
- * expandarg() flags
+ * Ignore a signal. Only one usage site - in forkchild()
  */
-#define EXP_FULL        0x1     /* perform word splitting & file globbing */
-#define EXP_TILDE       0x2     /* do normal tilde expansion */
-#define EXP_VARTILDE    0x4     /* expand tildes in an assignment */
-#define EXP_REDIR       0x8     /* file glob for a redirection (1 match only) */
-#define EXP_CASE        0x10    /* keeps quotes around for CASE pattern */
-#define EXP_RECORD      0x20    /* need to record arguments for ifs breakup */
-#define EXP_VARTILDE2   0x40    /* expand tildes after colons only */
-#define EXP_WORD        0x80    /* expand word in parameter expansion */
-#define EXP_QWORD       0x100   /* expand word in quoted parameter expansion */
-
-
-union node;
-static void expandarg(union node *, struct arglist *, int);
-#define rmescapes(p) _rmescapes((p), 0)
-static char *_rmescapes(char *, int);
-static int casematch(union node *, char *);
-
-#ifdef CONFIG_ASH_MATH_SUPPORT
-static void expari(int);
-#endif
-
-/*      eval.h       */
-
-static char *commandname;              /* currently executing command */
-static struct strlist *cmdenviron;     /* environment for builtin command */
-static int exitstatus;                 /* exit status of last command */
-static int back_exitstatus;            /* exit status of backquoted command */
-
-
-struct backcmd {                /* result of evalbackcmd */
-       int fd;                 /* file descriptor to read from */
-       char *buf;              /* buffer */
-       int nleft;              /* number of chars in buffer */
-       struct job *jp;         /* job structure for command */
-};
+static void
+ignoresig(int signo)
+{
+       if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
+               signal(signo, SIG_IGN);
+       }
+       sigmode[signo - 1] = S_HARD_IGN;
+}
 
 /*
- * This file was generated by the mknodes program.
+ * Signal handler. Only one usage site - in setsignal()
  */
+static void
+onsig(int signo)
+{
+       gotsig[signo - 1] = 1;
+       pendingsig = signo;
 
-#define NCMD 0
-#define NPIPE 1
-#define NREDIR 2
-#define NBACKGND 3
-#define NSUBSHELL 4
-#define NAND 5
-#define NOR 6
-#define NSEMI 7
-#define NIF 8
-#define NWHILE 9
-#define NUNTIL 10
-#define NFOR 11
-#define NCASE 12
-#define NCLIST 13
-#define NDEFUN 14
-#define NARG 15
-#define NTO 16
-#define NCLOBBER 17
-#define NFROM 18
-#define NFROMTO 19
-#define NAPPEND 20
-#define NTOFD 21
-#define NFROMFD 22
-#define NHERE 23
-#define NXHERE 24
-#define NNOT 25
-
+       if (exsig || (signo == SIGINT && !trap[SIGINT])) {
+               if (!suppressint) {
+                       pendingsig = 0;
+                       raise_interrupt();
+               }
+               intpending = 1;
+       }
+}
 
 
-struct ncmd {
-      int type;
-      union node *assign;
-      union node *args;
-      union node *redirect;
-};
+/* ============ Stdout/stderr output */
 
+static void
+outstr(const char *p, FILE *file)
+{
+       INT_OFF;
+       fputs(p, file);
+       INT_ON;
+}
 
-struct npipe {
-      int type;
-      int backgnd;
-      struct nodelist *cmdlist;
-};
+static void
+flush_stdout_stderr(void)
+{
+       INT_OFF;
+       fflush(stdout);
+       fflush(stderr);
+       INT_ON;
+}
 
+static void
+flush_stderr(void)
+{
+       INT_OFF;
+       fflush(stderr);
+       INT_ON;
+}
 
-struct nredir {
-      int type;
-      union node *n;
-      union node *redirect;
-};
+static void
+outcslow(int c, FILE *dest)
+{
+       INT_OFF;
+       putc(c, dest);
+       fflush(dest);
+       INT_ON;
+}
 
+static int out1fmt(const char *, ...) __attribute__((__format__(__printf__,1,2)));
+static int
+out1fmt(const char *fmt, ...)
+{
+       va_list ap;
+       int r;
 
-struct nbinary {
-      int type;
-      union node *ch1;
-      union node *ch2;
-};
-
-
-struct nif {
-      int type;
-      union node *test;
-      union node *ifpart;
-      union node *elsepart;
-};
-
-
-struct nfor {
-      int type;
-      union node *args;
-      union node *body;
-      char *var;
-};
-
-
-struct ncase {
-      int type;
-      union node *expr;
-      union node *cases;
-};
-
-
-struct nclist {
-      int type;
-      union node *next;
-      union node *pattern;
-      union node *body;
-};
-
-
-struct narg {
-      int type;
-      union node *next;
-      char *text;
-      struct nodelist *backquote;
-};
-
-
-struct nfile {
-      int type;
-      union node *next;
-      int fd;
-      union node *fname;
-      char *expfname;
-};
-
-
-struct ndup {
-      int type;
-      union node *next;
-      int fd;
-      int dupfd;
-      union node *vname;
-};
-
-
-struct nhere {
-      int type;
-      union node *next;
-      int fd;
-      union node *doc;
-};
-
-
-struct nnot {
-      int type;
-      union node *com;
-};
-
-
-union node {
-      int type;
-      struct ncmd ncmd;
-      struct npipe npipe;
-      struct nredir nredir;
-      struct nbinary nbinary;
-      struct nif nif;
-      struct nfor nfor;
-      struct ncase ncase;
-      struct nclist nclist;
-      struct narg narg;
-      struct nfile nfile;
-      struct ndup ndup;
-      struct nhere nhere;
-      struct nnot nnot;
-};
+       INT_OFF;
+       va_start(ap, fmt);
+       r = vprintf(fmt, ap);
+       va_end(ap);
+       INT_ON;
+       return r;
+}
 
+static int fmtstr(char *, size_t, const char *, ...) __attribute__((__format__(__printf__,3,4)));
+static int
+fmtstr(char *outbuf, size_t length, const char *fmt, ...)
+{
+       va_list ap;
+       int ret;
 
-struct nodelist {
-       struct nodelist *next;
-       union node *n;
-};
+       va_start(ap, fmt);
+       INT_OFF;
+       ret = vsnprintf(outbuf, length, fmt, ap);
+       va_end(ap);
+       INT_ON;
+       return ret;
+}
 
+static void
+out1str(const char *p)
+{
+       outstr(p, stdout);
+}
 
-struct funcnode {
-       int count;
-       union node n;
-};
+static void
+out2str(const char *p)
+{
+       outstr(p, stderr);
+       flush_stderr();
+}
 
 
-static void freefunc(struct funcnode *);
-/*      parser.h     */
+/* ============ Parser structures */
 
 /* control characters in argument strings */
-#define CTL_FIRST '\201'        /* first 'special' character */
 #define CTLESC '\201'           /* escape next character */
 #define CTLVAR '\202'           /* variable defn */
 #define CTLENDVAR '\203'
@@ -486,7 +429,6 @@ static void freefunc(struct funcnode *);
 #define CTLARI  '\206'          /* arithmetic expression */
 #define CTLENDARI '\207'
 #define CTLQUOTEMARK '\210'
-#define CTL_LAST '\210'         /* last 'special' character */
 
 /* variable substitution byte (follows CTLVAR) */
 #define VSTYPE  0x0f            /* type of variable substitution */
@@ -505,11848 +447,10912 @@ static void freefunc(struct funcnode *);
 #define VSTRIMLEFTMAX   0x9             /* ${var##pattern} */
 #define VSLENGTH        0xa             /* ${#var} */
 
-/* values of checkkwd variable */
-#define CHKALIAS        0x1
-#define CHKKWD          0x2
-#define CHKNL           0x4
-
-#define IBUFSIZ (BUFSIZ + 1)
-
-/*
- * NEOF is returned by parsecmd when it encounters an end of file.  It
- * must be distinct from NULL, so we use the address of a variable that
- * happens to be handy.
- */
-static int plinno = 1;                  /* input line number */
+static const char dolatstr[] ALIGN1 = {
+       CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0'
+};
 
-/* number of characters left in input buffer */
-static int parsenleft;                  /* copy of parsefile->nleft */
-static int parselleft;                  /* copy of parsefile->lleft */
+#define NCMD 0
+#define NPIPE 1
+#define NREDIR 2
+#define NBACKGND 3
+#define NSUBSHELL 4
+#define NAND 5
+#define NOR 6
+#define NSEMI 7
+#define NIF 8
+#define NWHILE 9
+#define NUNTIL 10
+#define NFOR 11
+#define NCASE 12
+#define NCLIST 13
+#define NDEFUN 14
+#define NARG 15
+#define NTO 16
+#define NCLOBBER 17
+#define NFROM 18
+#define NFROMTO 19
+#define NAPPEND 20
+#define NTOFD 21
+#define NFROMFD 22
+#define NHERE 23
+#define NXHERE 24
+#define NNOT 25
 
-/* next character in input buffer */
-static char *parsenextc;                /* copy of parsefile->nextc */
+union node;
 
-struct strpush {
-       struct strpush *prev;   /* preceding string on stack */
-       char *prevstring;
-       int prevnleft;
-#ifdef CONFIG_ASH_ALIAS
-       struct alias *ap;       /* if push was associated with an alias */
-#endif
-       char *string;           /* remember the string since it may change */
+struct ncmd {
+       int type;
+       union node *assign;
+       union node *args;
+       union node *redirect;
 };
 
-struct parsefile {
-       struct parsefile *prev; /* preceding file on stack */
-       int linno;              /* current line */
-       int fd;                 /* file descriptor (or -1 if string) */
-       int nleft;              /* number of chars left in this line */
-       int lleft;              /* number of chars left in this buffer */
-       char *nextc;            /* next char in buffer */
-       char *buf;              /* input buffer */
-       struct strpush *strpush; /* for pushing strings at this level */
-       struct strpush basestrpush; /* so pushing one is fast */
+struct npipe {
+       int type;
+       int backgnd;
+       struct nodelist *cmdlist;
 };
 
-static struct parsefile basepf;         /* top level input file */
-#define basebuf bb_common_bufsiz1       /* buffer for top level input file */
-static struct parsefile *parsefile = &basepf;  /* current input file */
+struct nredir {
+       int type;
+       union node *n;
+       union node *redirect;
+};
 
+struct nbinary {
+       int type;
+       union node *ch1;
+       union node *ch2;
+};
 
-static int tokpushback;                 /* last token pushed back */
-#define NEOF ((union node *)&tokpushback)
-static int parsebackquote;             /* nonzero if we are inside backquotes */
-static int doprompt;                   /* if set, prompt the user */
-static int needprompt;                 /* true if interactive and at start of line */
-static int lasttoken;                  /* last token read */
-static char *wordtext;                 /* text of last word returned by readtoken */
-static int checkkwd;
-static struct nodelist *backquotelist;
-static union node *redirnode;
-static struct heredoc *heredoc;
-static int quoteflag;                  /* set if (part of) last token was quoted */
-static int startlinno;                 /* line # where last token started */
+struct nif {
+       int type;
+       union node *test;
+       union node *ifpart;
+       union node *elsepart;
+};
 
-static union node *parsecmd(int);
-static void fixredir(union node *, const char *, int);
-static const char *const *findkwd(const char *);
-static char *endofname(const char *);
+struct nfor {
+       int type;
+       union node *args;
+       union node *body;
+       char *var;
+};
 
-/*      shell.h   */
+struct ncase {
+       int type;
+       union node *expr;
+       union node *cases;
+};
 
-typedef void *pointer;
+struct nclist {
+       int type;
+       union node *next;
+       union node *pattern;
+       union node *body;
+};
 
-static char nullstr[1];                /* zero length string */
-static const char spcstr[] = " ";
-static const char snlfmt[] = "%s\n";
-static const char dolatstr[] = { CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' };
-static const char illnum[] = "Illegal number: %s";
-static const char homestr[] = "HOME";
+struct narg {
+       int type;
+       union node *next;
+       char *text;
+       struct nodelist *backquote;
+};
 
-#if DEBUG
-#define TRACE(param)    trace param
-#define TRACEV(param)   tracev param
-#else
-#define TRACE(param)
-#define TRACEV(param)
-#endif
+struct nfile {
+       int type;
+       union node *next;
+       int fd;
+       union node *fname;
+       char *expfname;
+};
 
-#if !defined(__GNUC__) || (__GNUC__ == 2 && __GNUC_MINOR__ < 96)
-#define __builtin_expect(x, expected_value) (x)
-#endif
+struct ndup {
+       int type;
+       union node *next;
+       int fd;
+       int dupfd;
+       union node *vname;
+};
 
-#define xlikely(x)       __builtin_expect((x),1)
+struct nhere {
+       int type;
+       union node *next;
+       int fd;
+       union node *doc;
+};
 
+struct nnot {
+       int type;
+       union node *com;
+};
 
-#define TEOF 0
-#define TNL 1
-#define TREDIR 2
-#define TWORD 3
-#define TSEMI 4
-#define TBACKGND 5
-#define TAND 6
-#define TOR 7
-#define TPIPE 8
-#define TLP 9
-#define TRP 10
-#define TENDCASE 11
-#define TENDBQUOTE 12
-#define TNOT 13
-#define TCASE 14
-#define TDO 15
-#define TDONE 16
-#define TELIF 17
-#define TELSE 18
-#define TESAC 19
-#define TFI 20
-#define TFOR 21
-#define TIF 22
-#define TIN 23
-#define TTHEN 24
-#define TUNTIL 25
-#define TWHILE 26
-#define TBEGIN 27
-#define TEND 28
+union node {
+       int type;
+       struct ncmd ncmd;
+       struct npipe npipe;
+       struct nredir nredir;
+       struct nbinary nbinary;
+       struct nif nif;
+       struct nfor nfor;
+       struct ncase ncase;
+       struct nclist nclist;
+       struct narg narg;
+       struct nfile nfile;
+       struct ndup ndup;
+       struct nhere nhere;
+       struct nnot nnot;
+};
 
-/* first char is indicating which tokens mark the end of a list */
-static const char *const tokname_array[] = {
-       "\1end of file",
-       "\0newline",
-       "\0redirection",
-       "\0word",
-       "\0;",
-       "\0&",
-       "\0&&",
-       "\0||",
-       "\0|",
-       "\0(",
-       "\1)",
-       "\1;;",
-       "\1`",
-#define KWDOFFSET 13
-       /* the following are keywords */
-       "\0!",
-       "\0case",
-       "\1do",
-       "\1done",
-       "\1elif",
-       "\1else",
-       "\1esac",
-       "\1fi",
-       "\0for",
-       "\0if",
-       "\0in",
-       "\1then",
-       "\0until",
-       "\0while",
-       "\0{",
-       "\1}",
+struct nodelist {
+       struct nodelist *next;
+       union node *n;
 };
 
-static const char *tokname(int tok)
-{
-       static char buf[16];
+struct funcnode {
+       int count;
+       union node n;
+};
 
-       if (tok >= TSEMI)
-               buf[0] = '"';
-       sprintf(buf + (tok >= TSEMI), "%s%c",
-                       tokname_array[tok] + 1, (tok >= TSEMI ? '"' : 0));
-       return buf;
-}
-
-/*      machdep.h    */
-
-/*
- * Most machines require the value returned from malloc to be aligned
- * in some way.  The following macro will get this right on many machines.
- */
-
-#define SHELL_SIZE (sizeof(union {int i; char *cp; double d; }) - 1)
 /*
- * It appears that grabstackstr() will barf with such alignments
- * because stalloc() will return a string allocated in a new stackblock.
+ * Free a parse tree.
  */
-#define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE)
+static void
+freefunc(struct funcnode *f)
+{
+       if (f && --f->count < 0)
+               free(f);
+}
 
-/*
- * This file was generated by the mksyntax program.
- */
 
+/* ============ Debugging output */
 
-/* Syntax classes */
-#define CWORD 0                 /* character is nothing special */
-#define CNL 1                   /* newline character */
-#define CBACK 2                 /* a backslash character */
-#define CSQUOTE 3               /* single quote */
-#define CDQUOTE 4               /* double quote */
-#define CENDQUOTE 5             /* a terminating quote */
-#define CBQUOTE 6               /* backwards single quote */
-#define CVAR 7                  /* a dollar sign */
-#define CENDVAR 8               /* a '}' character */
-#define CLP 9                   /* a left paren in arithmetic */
-#define CRP 10                  /* a right paren in arithmetic */
-#define CENDFILE 11             /* end of file */
-#define CCTL 12                 /* like CWORD, except it must be escaped */
-#define CSPCL 13                /* these terminate a word */
-#define CIGN 14                 /* character should be ignored */
+#if DEBUG
 
-#ifdef CONFIG_ASH_ALIAS
-#define SYNBASE 130
-#define PEOF -130
-#define PEOA -129
-#define PEOA_OR_PEOF PEOA
-#else
-#define SYNBASE 129
-#define PEOF -129
-#define PEOA_OR_PEOF PEOF
-#endif
+static FILE *tracefile;
 
-#define is_digit(c)     ((unsigned)((c) - '0') <= 9)
-#define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
-#define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
+static void
+trace_printf(const char *fmt, ...)
+{
+       va_list va;
 
-/* C99 say: "char" declaration may be signed or unsigned default */
-#define SC2INT(chr2may_be_negative_int) (int)((signed char)chr2may_be_negative_int)
+       if (debug != 1)
+               return;
+       va_start(va, fmt);
+       vfprintf(tracefile, fmt, va);
+       va_end(va);
+}
 
-/*
- * is_special(c) evaluates to 1 for c in "!#$*-0123456789?@"; 0 otherwise
- * (assuming ascii char codes, as the original implementation did)
- */
-#define is_special(c) \
-    ( (((unsigned int)c) - 33 < 32) \
-                        && ((0xc1ff920dUL >> (((unsigned int)c) - 33)) & 1))
+static void
+trace_vprintf(const char *fmt, va_list va)
+{
+       if (debug != 1)
+               return;
+       vfprintf(tracefile, fmt, va);
+}
 
-#define digit_val(c)    ((c) - '0')
+static void
+trace_puts(const char *s)
+{
+       if (debug != 1)
+               return;
+       fputs(s, tracefile);
+}
 
-/*
- * This file was generated by the mksyntax program.
- */
+static void
+trace_puts_quoted(char *s)
+{
+       char *p;
+       char c;
 
-#ifdef CONFIG_ASH_OPTIMIZE_FOR_SIZE
-#define USE_SIT_FUNCTION
-#endif
+       if (debug != 1)
+               return;
+       putc('"', tracefile);
+       for (p = s; *p; p++) {
+               switch (*p) {
+               case '\n':  c = 'n';  goto backslash;
+               case '\t':  c = 't';  goto backslash;
+               case '\r':  c = 'r';  goto backslash;
+               case '"':  c = '"';  goto backslash;
+               case '\\':  c = '\\';  goto backslash;
+               case CTLESC:  c = 'e';  goto backslash;
+               case CTLVAR:  c = 'v';  goto backslash;
+               case CTLVAR+CTLQUOTE:  c = 'V'; goto backslash;
+               case CTLBACKQ:  c = 'q';  goto backslash;
+               case CTLBACKQ+CTLQUOTE:  c = 'Q'; goto backslash;
+ backslash:
+                       putc('\\', tracefile);
+                       putc(c, tracefile);
+                       break;
+               default:
+                       if (*p >= ' ' && *p <= '~')
+                               putc(*p, tracefile);
+                       else {
+                               putc('\\', tracefile);
+                               putc(*p >> 6 & 03, tracefile);
+                               putc(*p >> 3 & 07, tracefile);
+                               putc(*p & 07, tracefile);
+                       }
+                       break;
+               }
+       }
+       putc('"', tracefile);
+}
 
-/* number syntax index */
-#define  BASESYNTAX  0  /* not in quotes */
-#define  DQSYNTAX    1  /* in double quotes */
-#define  SQSYNTAX    2  /* in single quotes */
-#define  ARISYNTAX   3  /* in arithmetic */
+static void
+trace_puts_args(char **ap)
+{
+       if (debug != 1)
+               return;
+       if (!*ap)
+               return;
+       while (1) {
+               trace_puts_quoted(*ap);
+               if (!*++ap) {
+                       putc('\n', tracefile);
+                       break;
+               }
+               putc(' ', tracefile);
+       }
+}
 
-#ifdef CONFIG_ASH_MATH_SUPPORT
-static const char S_I_T[][4] = {
-#ifdef CONFIG_ASH_ALIAS
-       {CSPCL, CIGN, CIGN, CIGN},              /* 0, PEOA */
-#endif
-       {CSPCL, CWORD, CWORD, CWORD},           /* 1, ' ' */
-       {CNL, CNL, CNL, CNL},                   /* 2, \n */
-       {CWORD, CCTL, CCTL, CWORD},             /* 3, !*-/:=?[]~ */
-       {CDQUOTE, CENDQUOTE, CWORD, CWORD},     /* 4, '"' */
-       {CVAR, CVAR, CWORD, CVAR},              /* 5, $ */
-       {CSQUOTE, CWORD, CENDQUOTE, CWORD},     /* 6, "'" */
-       {CSPCL, CWORD, CWORD, CLP},             /* 7, ( */
-       {CSPCL, CWORD, CWORD, CRP},             /* 8, ) */
-       {CBACK, CBACK, CCTL, CBACK},            /* 9, \ */
-       {CBQUOTE, CBQUOTE, CWORD, CBQUOTE},     /* 10, ` */
-       {CENDVAR, CENDVAR, CWORD, CENDVAR},     /* 11, } */
-#ifndef USE_SIT_FUNCTION
-       {CENDFILE, CENDFILE, CENDFILE, CENDFILE},       /* 12, PEOF */
-       {CWORD, CWORD, CWORD, CWORD},           /* 13, 0-9A-Za-z */
-       {CCTL, CCTL, CCTL, CCTL}                /* 14, CTLESC ... */
+static void
+opentrace(void)
+{
+       char s[100];
+#ifdef O_APPEND
+       int flags;
 #endif
-};
-#else
-static const char S_I_T[][3] = {
-#ifdef CONFIG_ASH_ALIAS
-       {CSPCL, CIGN, CIGN},                    /* 0, PEOA */
-#endif
-       {CSPCL, CWORD, CWORD},                  /* 1, ' ' */
-       {CNL, CNL, CNL},                        /* 2, \n */
-       {CWORD, CCTL, CCTL},                    /* 3, !*-/:=?[]~ */
-       {CDQUOTE, CENDQUOTE, CWORD},            /* 4, '"' */
-       {CVAR, CVAR, CWORD},                    /* 5, $ */
-       {CSQUOTE, CWORD, CENDQUOTE},            /* 6, "'" */
-       {CSPCL, CWORD, CWORD},                  /* 7, ( */
-       {CSPCL, CWORD, CWORD},                  /* 8, ) */
-       {CBACK, CBACK, CCTL},                   /* 9, \ */
-       {CBQUOTE, CBQUOTE, CWORD},              /* 10, ` */
-       {CENDVAR, CENDVAR, CWORD},              /* 11, } */
-#ifndef USE_SIT_FUNCTION
-       {CENDFILE, CENDFILE, CENDFILE},         /* 12, PEOF */
-       {CWORD, CWORD, CWORD},                  /* 13, 0-9A-Za-z */
-       {CCTL, CCTL, CCTL}                      /* 14, CTLESC ... */
+
+       if (debug != 1) {
+               if (tracefile)
+                       fflush(tracefile);
+               /* leave open because libedit might be using it */
+               return;
+       }
+       strcpy(s, "./trace");
+       if (tracefile) {
+               if (!freopen(s, "a", tracefile)) {
+                       fprintf(stderr, "Can't re-open %s\n", s);
+                       debug = 0;
+                       return;
+               }
+       } else {
+               tracefile = fopen(s, "a");
+               if (tracefile == NULL) {
+                       fprintf(stderr, "Can't open %s\n", s);
+                       debug = 0;
+                       return;
+               }
+       }
+#ifdef O_APPEND
+       flags = fcntl(fileno(tracefile), F_GETFL);
+       if (flags >= 0)
+               fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
 #endif
-};
-#endif /* CONFIG_ASH_MATH_SUPPORT */
+       setlinebuf(tracefile);
+       fputs("\nTracing started.\n", tracefile);
+}
 
-#ifdef USE_SIT_FUNCTION
+static void
+indent(int amount, char *pfx, FILE *fp)
+{
+       int i;
 
-#define U_C(c) ((unsigned char)(c))
+       for (i = 0; i < amount; i++) {
+               if (pfx && i == amount - 1)
+                       fputs(pfx, fp);
+               putc('\t', fp);
+       }
+}
 
-static int SIT(int c, int syntax)
+/* little circular references here... */
+static void shtree(union node *n, int ind, char *pfx, FILE *fp);
+
+static void
+sharg(union node *arg, FILE *fp)
 {
-       static const char spec_symbls[] = "\t\n !\"$&'()*-/:;<=>?[\\]`|}~";
-#ifdef CONFIG_ASH_ALIAS
-       static const char syntax_index_table[] = {
-               1, 2, 1, 3, 4, 5, 1, 6,         /* "\t\n !\"$&'" */
-               7, 8, 3, 3, 3, 3, 1, 1,         /* "()*-/:;<" */
-               3, 1, 3, 3, 9, 3, 10, 1,        /* "=>?[\\]`|" */
-               11, 3                           /* "}~" */
-       };
-#else
-       static const char syntax_index_table[] = {
-               0, 1, 0, 2, 3, 4, 0, 5,         /* "\t\n !\"$&'" */
-               6, 7, 2, 2, 2, 2, 0, 0,         /* "()*-/:;<" */
-               2, 0, 2, 2, 8, 2, 9, 0,         /* "=>?[\\]`|" */
-               10, 2                           /* "}~" */
-       };
-#endif
-       const char *s;
-       int indx;
+       char *p;
+       struct nodelist *bqlist;
+       int subtype;
 
-       if (c == PEOF)          /* 2^8+2 */
-               return CENDFILE;
-#ifdef CONFIG_ASH_ALIAS
-       if (c == PEOA)          /* 2^8+1 */
-               indx = 0;
-       else
-#endif
-               if (U_C(c) >= U_C(CTLESC) && U_C(c) <= U_C(CTLQUOTEMARK))
-                       return CCTL;
-       else {
-               s = strchr(spec_symbls, c);
-               if (s == 0 || *s == 0)
-                       return CWORD;
-               indx = syntax_index_table[(s - spec_symbls)];
+       if (arg->type != NARG) {
+               out1fmt("<node type %d>\n", arg->type);
+               abort();
        }
-       return S_I_T[indx][syntax];
-}
+       bqlist = arg->narg.backquote;
+       for (p = arg->narg.text; *p; p++) {
+               switch (*p) {
+               case CTLESC:
+                       putc(*++p, fp);
+                       break;
+               case CTLVAR:
+                       putc('$', fp);
+                       putc('{', fp);
+                       subtype = *++p;
+                       if (subtype == VSLENGTH)
+                               putc('#', fp);
 
-#else   /* USE_SIT_FUNCTION */
-
-#define SIT(c, syntax) S_I_T[(int)syntax_index_table[((int)c)+SYNBASE]][syntax]
-
-#ifdef CONFIG_ASH_ALIAS
-#define CSPCL_CIGN_CIGN_CIGN                           0
-#define CSPCL_CWORD_CWORD_CWORD                        1
-#define CNL_CNL_CNL_CNL                                2
-#define CWORD_CCTL_CCTL_CWORD                          3
-#define CDQUOTE_CENDQUOTE_CWORD_CWORD                  4
-#define CVAR_CVAR_CWORD_CVAR                           5
-#define CSQUOTE_CWORD_CENDQUOTE_CWORD                  6
-#define CSPCL_CWORD_CWORD_CLP                          7
-#define CSPCL_CWORD_CWORD_CRP                          8
-#define CBACK_CBACK_CCTL_CBACK                         9
-#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE                 10
-#define CENDVAR_CENDVAR_CWORD_CENDVAR                 11
-#define CENDFILE_CENDFILE_CENDFILE_CENDFILE           12
-#define CWORD_CWORD_CWORD_CWORD                       13
-#define CCTL_CCTL_CCTL_CCTL                           14
-#else
-#define CSPCL_CWORD_CWORD_CWORD                        0
-#define CNL_CNL_CNL_CNL                                1
-#define CWORD_CCTL_CCTL_CWORD                          2
-#define CDQUOTE_CENDQUOTE_CWORD_CWORD                  3
-#define CVAR_CVAR_CWORD_CVAR                           4
-#define CSQUOTE_CWORD_CENDQUOTE_CWORD                  5
-#define CSPCL_CWORD_CWORD_CLP                          6
-#define CSPCL_CWORD_CWORD_CRP                          7
-#define CBACK_CBACK_CCTL_CBACK                         8
-#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE                  9
-#define CENDVAR_CENDVAR_CWORD_CENDVAR                 10
-#define CENDFILE_CENDFILE_CENDFILE_CENDFILE           11
-#define CWORD_CWORD_CWORD_CWORD                       12
-#define CCTL_CCTL_CCTL_CCTL                           13
-#endif
+                       while (*p != '=')
+                               putc(*p++, fp);
 
-static const char syntax_index_table[258] = {
-       /* BASESYNTAX_DQSYNTAX_SQSYNTAX_ARISYNTAX */
-       /*   0  PEOF */      CENDFILE_CENDFILE_CENDFILE_CENDFILE,
-#ifdef CONFIG_ASH_ALIAS
-       /*   1  PEOA */      CSPCL_CIGN_CIGN_CIGN,
-#endif
-       /*   2  -128 0x80 */ CWORD_CWORD_CWORD_CWORD,
-       /*   3  -127 CTLESC       */ CCTL_CCTL_CCTL_CCTL,
-       /*   4  -126 CTLVAR       */ CCTL_CCTL_CCTL_CCTL,
-       /*   5  -125 CTLENDVAR    */ CCTL_CCTL_CCTL_CCTL,
-       /*   6  -124 CTLBACKQ     */ CCTL_CCTL_CCTL_CCTL,
-       /*   7  -123 CTLQUOTE     */ CCTL_CCTL_CCTL_CCTL,
-       /*   8  -122 CTLARI       */ CCTL_CCTL_CCTL_CCTL,
-       /*   9  -121 CTLENDARI    */ CCTL_CCTL_CCTL_CCTL,
-       /*  10  -120 CTLQUOTEMARK */ CCTL_CCTL_CCTL_CCTL,
-       /*  11  -119      */ CWORD_CWORD_CWORD_CWORD,
-       /*  12  -118      */ CWORD_CWORD_CWORD_CWORD,
-       /*  13  -117      */ CWORD_CWORD_CWORD_CWORD,
-       /*  14  -116      */ CWORD_CWORD_CWORD_CWORD,
-       /*  15  -115      */ CWORD_CWORD_CWORD_CWORD,
-       /*  16  -114      */ CWORD_CWORD_CWORD_CWORD,
-       /*  17  -113      */ CWORD_CWORD_CWORD_CWORD,
-       /*  18  -112      */ CWORD_CWORD_CWORD_CWORD,
-       /*  19  -111      */ CWORD_CWORD_CWORD_CWORD,
-       /*  20  -110      */ CWORD_CWORD_CWORD_CWORD,
-       /*  21  -109      */ CWORD_CWORD_CWORD_CWORD,
-       /*  22  -108      */ CWORD_CWORD_CWORD_CWORD,
-       /*  23  -107      */ CWORD_CWORD_CWORD_CWORD,
-       /*  24  -106      */ CWORD_CWORD_CWORD_CWORD,
-       /*  25  -105      */ CWORD_CWORD_CWORD_CWORD,
-       /*  26  -104      */ CWORD_CWORD_CWORD_CWORD,
-       /*  27  -103      */ CWORD_CWORD_CWORD_CWORD,
-       /*  28  -102      */ CWORD_CWORD_CWORD_CWORD,
-       /*  29  -101      */ CWORD_CWORD_CWORD_CWORD,
-       /*  30  -100      */ CWORD_CWORD_CWORD_CWORD,
-       /*  31   -99      */ CWORD_CWORD_CWORD_CWORD,
-       /*  32   -98      */ CWORD_CWORD_CWORD_CWORD,
-       /*  33   -97      */ CWORD_CWORD_CWORD_CWORD,
-       /*  34   -96      */ CWORD_CWORD_CWORD_CWORD,
-       /*  35   -95      */ CWORD_CWORD_CWORD_CWORD,
-       /*  36   -94      */ CWORD_CWORD_CWORD_CWORD,
-       /*  37   -93      */ CWORD_CWORD_CWORD_CWORD,
-       /*  38   -92      */ CWORD_CWORD_CWORD_CWORD,
-       /*  39   -91      */ CWORD_CWORD_CWORD_CWORD,
-       /*  40   -90      */ CWORD_CWORD_CWORD_CWORD,
-       /*  41   -89      */ CWORD_CWORD_CWORD_CWORD,
-       /*  42   -88      */ CWORD_CWORD_CWORD_CWORD,
-       /*  43   -87      */ CWORD_CWORD_CWORD_CWORD,
-       /*  44   -86      */ CWORD_CWORD_CWORD_CWORD,
-       /*  45   -85      */ CWORD_CWORD_CWORD_CWORD,
-       /*  46   -84      */ CWORD_CWORD_CWORD_CWORD,
-       /*  47   -83      */ CWORD_CWORD_CWORD_CWORD,
-       /*  48   -82      */ CWORD_CWORD_CWORD_CWORD,
-       /*  49   -81      */ CWORD_CWORD_CWORD_CWORD,
-       /*  50   -80      */ CWORD_CWORD_CWORD_CWORD,
-       /*  51   -79      */ CWORD_CWORD_CWORD_CWORD,
-       /*  52   -78      */ CWORD_CWORD_CWORD_CWORD,
-       /*  53   -77      */ CWORD_CWORD_CWORD_CWORD,
-       /*  54   -76      */ CWORD_CWORD_CWORD_CWORD,
-       /*  55   -75      */ CWORD_CWORD_CWORD_CWORD,
-       /*  56   -74      */ CWORD_CWORD_CWORD_CWORD,
-       /*  57   -73      */ CWORD_CWORD_CWORD_CWORD,
-       /*  58   -72      */ CWORD_CWORD_CWORD_CWORD,
-       /*  59   -71      */ CWORD_CWORD_CWORD_CWORD,
-       /*  60   -70      */ CWORD_CWORD_CWORD_CWORD,
-       /*  61   -69      */ CWORD_CWORD_CWORD_CWORD,
-       /*  62   -68      */ CWORD_CWORD_CWORD_CWORD,
-       /*  63   -67      */ CWORD_CWORD_CWORD_CWORD,
-       /*  64   -66      */ CWORD_CWORD_CWORD_CWORD,
-       /*  65   -65      */ CWORD_CWORD_CWORD_CWORD,
-       /*  66   -64      */ CWORD_CWORD_CWORD_CWORD,
-       /*  67   -63      */ CWORD_CWORD_CWORD_CWORD,
-       /*  68   -62      */ CWORD_CWORD_CWORD_CWORD,
-       /*  69   -61      */ CWORD_CWORD_CWORD_CWORD,
-       /*  70   -60      */ CWORD_CWORD_CWORD_CWORD,
-       /*  71   -59      */ CWORD_CWORD_CWORD_CWORD,
-       /*  72   -58      */ CWORD_CWORD_CWORD_CWORD,
-       /*  73   -57      */ CWORD_CWORD_CWORD_CWORD,
-       /*  74   -56      */ CWORD_CWORD_CWORD_CWORD,
-       /*  75   -55      */ CWORD_CWORD_CWORD_CWORD,
-       /*  76   -54      */ CWORD_CWORD_CWORD_CWORD,
-       /*  77   -53      */ CWORD_CWORD_CWORD_CWORD,
-       /*  78   -52      */ CWORD_CWORD_CWORD_CWORD,
-       /*  79   -51      */ CWORD_CWORD_CWORD_CWORD,
-       /*  80   -50      */ CWORD_CWORD_CWORD_CWORD,
-       /*  81   -49      */ CWORD_CWORD_CWORD_CWORD,
-       /*  82   -48      */ CWORD_CWORD_CWORD_CWORD,
-       /*  83   -47      */ CWORD_CWORD_CWORD_CWORD,
-       /*  84   -46      */ CWORD_CWORD_CWORD_CWORD,
-       /*  85   -45      */ CWORD_CWORD_CWORD_CWORD,
-       /*  86   -44      */ CWORD_CWORD_CWORD_CWORD,
-       /*  87   -43      */ CWORD_CWORD_CWORD_CWORD,
-       /*  88   -42      */ CWORD_CWORD_CWORD_CWORD,
-       /*  89   -41      */ CWORD_CWORD_CWORD_CWORD,
-       /*  90   -40      */ CWORD_CWORD_CWORD_CWORD,
-       /*  91   -39      */ CWORD_CWORD_CWORD_CWORD,
-       /*  92   -38      */ CWORD_CWORD_CWORD_CWORD,
-       /*  93   -37      */ CWORD_CWORD_CWORD_CWORD,
-       /*  94   -36      */ CWORD_CWORD_CWORD_CWORD,
-       /*  95   -35      */ CWORD_CWORD_CWORD_CWORD,
-       /*  96   -34      */ CWORD_CWORD_CWORD_CWORD,
-       /*  97   -33      */ CWORD_CWORD_CWORD_CWORD,
-       /*  98   -32      */ CWORD_CWORD_CWORD_CWORD,
-       /*  99   -31      */ CWORD_CWORD_CWORD_CWORD,
-       /* 100   -30      */ CWORD_CWORD_CWORD_CWORD,
-       /* 101   -29      */ CWORD_CWORD_CWORD_CWORD,
-       /* 102   -28      */ CWORD_CWORD_CWORD_CWORD,
-       /* 103   -27      */ CWORD_CWORD_CWORD_CWORD,
-       /* 104   -26      */ CWORD_CWORD_CWORD_CWORD,
-       /* 105   -25      */ CWORD_CWORD_CWORD_CWORD,
-       /* 106   -24      */ CWORD_CWORD_CWORD_CWORD,
-       /* 107   -23      */ CWORD_CWORD_CWORD_CWORD,
-       /* 108   -22      */ CWORD_CWORD_CWORD_CWORD,
-       /* 109   -21      */ CWORD_CWORD_CWORD_CWORD,
-       /* 110   -20      */ CWORD_CWORD_CWORD_CWORD,
-       /* 111   -19      */ CWORD_CWORD_CWORD_CWORD,
-       /* 112   -18      */ CWORD_CWORD_CWORD_CWORD,
-       /* 113   -17      */ CWORD_CWORD_CWORD_CWORD,
-       /* 114   -16      */ CWORD_CWORD_CWORD_CWORD,
-       /* 115   -15      */ CWORD_CWORD_CWORD_CWORD,
-       /* 116   -14      */ CWORD_CWORD_CWORD_CWORD,
-       /* 117   -13      */ CWORD_CWORD_CWORD_CWORD,
-       /* 118   -12      */ CWORD_CWORD_CWORD_CWORD,
-       /* 119   -11      */ CWORD_CWORD_CWORD_CWORD,
-       /* 120   -10      */ CWORD_CWORD_CWORD_CWORD,
-       /* 121    -9      */ CWORD_CWORD_CWORD_CWORD,
-       /* 122    -8      */ CWORD_CWORD_CWORD_CWORD,
-       /* 123    -7      */ CWORD_CWORD_CWORD_CWORD,
-       /* 124    -6      */ CWORD_CWORD_CWORD_CWORD,
-       /* 125    -5      */ CWORD_CWORD_CWORD_CWORD,
-       /* 126    -4      */ CWORD_CWORD_CWORD_CWORD,
-       /* 127    -3      */ CWORD_CWORD_CWORD_CWORD,
-       /* 128    -2      */ CWORD_CWORD_CWORD_CWORD,
-       /* 129    -1      */ CWORD_CWORD_CWORD_CWORD,
-       /* 130     0      */ CWORD_CWORD_CWORD_CWORD,
-       /* 131     1      */ CWORD_CWORD_CWORD_CWORD,
-       /* 132     2      */ CWORD_CWORD_CWORD_CWORD,
-       /* 133     3      */ CWORD_CWORD_CWORD_CWORD,
-       /* 134     4      */ CWORD_CWORD_CWORD_CWORD,
-       /* 135     5      */ CWORD_CWORD_CWORD_CWORD,
-       /* 136     6      */ CWORD_CWORD_CWORD_CWORD,
-       /* 137     7      */ CWORD_CWORD_CWORD_CWORD,
-       /* 138     8      */ CWORD_CWORD_CWORD_CWORD,
-       /* 139     9 "\t" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 140    10 "\n" */ CNL_CNL_CNL_CNL,
-       /* 141    11      */ CWORD_CWORD_CWORD_CWORD,
-       /* 142    12      */ CWORD_CWORD_CWORD_CWORD,
-       /* 143    13      */ CWORD_CWORD_CWORD_CWORD,
-       /* 144    14      */ CWORD_CWORD_CWORD_CWORD,
-       /* 145    15      */ CWORD_CWORD_CWORD_CWORD,
-       /* 146    16      */ CWORD_CWORD_CWORD_CWORD,
-       /* 147    17      */ CWORD_CWORD_CWORD_CWORD,
-       /* 148    18      */ CWORD_CWORD_CWORD_CWORD,
-       /* 149    19      */ CWORD_CWORD_CWORD_CWORD,
-       /* 150    20      */ CWORD_CWORD_CWORD_CWORD,
-       /* 151    21      */ CWORD_CWORD_CWORD_CWORD,
-       /* 152    22      */ CWORD_CWORD_CWORD_CWORD,
-       /* 153    23      */ CWORD_CWORD_CWORD_CWORD,
-       /* 154    24      */ CWORD_CWORD_CWORD_CWORD,
-       /* 155    25      */ CWORD_CWORD_CWORD_CWORD,
-       /* 156    26      */ CWORD_CWORD_CWORD_CWORD,
-       /* 157    27      */ CWORD_CWORD_CWORD_CWORD,
-       /* 158    28      */ CWORD_CWORD_CWORD_CWORD,
-       /* 159    29      */ CWORD_CWORD_CWORD_CWORD,
-       /* 160    30      */ CWORD_CWORD_CWORD_CWORD,
-       /* 161    31      */ CWORD_CWORD_CWORD_CWORD,
-       /* 162    32  " " */ CSPCL_CWORD_CWORD_CWORD,
-       /* 163    33  "!" */ CWORD_CCTL_CCTL_CWORD,
-       /* 164    34  """ */ CDQUOTE_CENDQUOTE_CWORD_CWORD,
-       /* 165    35  "#" */ CWORD_CWORD_CWORD_CWORD,
-       /* 166    36  "$" */ CVAR_CVAR_CWORD_CVAR,
-       /* 167    37  "%" */ CWORD_CWORD_CWORD_CWORD,
-       /* 168    38  "&" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 169    39  "'" */ CSQUOTE_CWORD_CENDQUOTE_CWORD,
-       /* 170    40  "(" */ CSPCL_CWORD_CWORD_CLP,
-       /* 171    41  ")" */ CSPCL_CWORD_CWORD_CRP,
-       /* 172    42  "*" */ CWORD_CCTL_CCTL_CWORD,
-       /* 173    43  "+" */ CWORD_CWORD_CWORD_CWORD,
-       /* 174    44  "," */ CWORD_CWORD_CWORD_CWORD,
-       /* 175    45  "-" */ CWORD_CCTL_CCTL_CWORD,
-       /* 176    46  "." */ CWORD_CWORD_CWORD_CWORD,
-       /* 177    47  "/" */ CWORD_CCTL_CCTL_CWORD,
-       /* 178    48  "0" */ CWORD_CWORD_CWORD_CWORD,
-       /* 179    49  "1" */ CWORD_CWORD_CWORD_CWORD,
-       /* 180    50  "2" */ CWORD_CWORD_CWORD_CWORD,
-       /* 181    51  "3" */ CWORD_CWORD_CWORD_CWORD,
-       /* 182    52  "4" */ CWORD_CWORD_CWORD_CWORD,
-       /* 183    53  "5" */ CWORD_CWORD_CWORD_CWORD,
-       /* 184    54  "6" */ CWORD_CWORD_CWORD_CWORD,
-       /* 185    55  "7" */ CWORD_CWORD_CWORD_CWORD,
-       /* 186    56  "8" */ CWORD_CWORD_CWORD_CWORD,
-       /* 187    57  "9" */ CWORD_CWORD_CWORD_CWORD,
-       /* 188    58  ":" */ CWORD_CCTL_CCTL_CWORD,
-       /* 189    59  ";" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 190    60  "<" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 191    61  "=" */ CWORD_CCTL_CCTL_CWORD,
-       /* 192    62  ">" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 193    63  "?" */ CWORD_CCTL_CCTL_CWORD,
-       /* 194    64  "@" */ CWORD_CWORD_CWORD_CWORD,
-       /* 195    65  "A" */ CWORD_CWORD_CWORD_CWORD,
-       /* 196    66  "B" */ CWORD_CWORD_CWORD_CWORD,
-       /* 197    67  "C" */ CWORD_CWORD_CWORD_CWORD,
-       /* 198    68  "D" */ CWORD_CWORD_CWORD_CWORD,
-       /* 199    69  "E" */ CWORD_CWORD_CWORD_CWORD,
-       /* 200    70  "F" */ CWORD_CWORD_CWORD_CWORD,
-       /* 201    71  "G" */ CWORD_CWORD_CWORD_CWORD,
-       /* 202    72  "H" */ CWORD_CWORD_CWORD_CWORD,
-       /* 203    73  "I" */ CWORD_CWORD_CWORD_CWORD,
-       /* 204    74  "J" */ CWORD_CWORD_CWORD_CWORD,
-       /* 205    75  "K" */ CWORD_CWORD_CWORD_CWORD,
-       /* 206    76  "L" */ CWORD_CWORD_CWORD_CWORD,
-       /* 207    77  "M" */ CWORD_CWORD_CWORD_CWORD,
-       /* 208    78  "N" */ CWORD_CWORD_CWORD_CWORD,
-       /* 209    79  "O" */ CWORD_CWORD_CWORD_CWORD,
-       /* 210    80  "P" */ CWORD_CWORD_CWORD_CWORD,
-       /* 211    81  "Q" */ CWORD_CWORD_CWORD_CWORD,
-       /* 212    82  "R" */ CWORD_CWORD_CWORD_CWORD,
-       /* 213    83  "S" */ CWORD_CWORD_CWORD_CWORD,
-       /* 214    84  "T" */ CWORD_CWORD_CWORD_CWORD,
-       /* 215    85  "U" */ CWORD_CWORD_CWORD_CWORD,
-       /* 216    86  "V" */ CWORD_CWORD_CWORD_CWORD,
-       /* 217    87  "W" */ CWORD_CWORD_CWORD_CWORD,
-       /* 218    88  "X" */ CWORD_CWORD_CWORD_CWORD,
-       /* 219    89  "Y" */ CWORD_CWORD_CWORD_CWORD,
-       /* 220    90  "Z" */ CWORD_CWORD_CWORD_CWORD,
-       /* 221    91  "[" */ CWORD_CCTL_CCTL_CWORD,
-       /* 222    92  "\" */ CBACK_CBACK_CCTL_CBACK,
-       /* 223    93  "]" */ CWORD_CCTL_CCTL_CWORD,
-       /* 224    94  "^" */ CWORD_CWORD_CWORD_CWORD,
-       /* 225    95  "_" */ CWORD_CWORD_CWORD_CWORD,
-       /* 226    96  "`" */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE,
-       /* 227    97  "a" */ CWORD_CWORD_CWORD_CWORD,
-       /* 228    98  "b" */ CWORD_CWORD_CWORD_CWORD,
-       /* 229    99  "c" */ CWORD_CWORD_CWORD_CWORD,
-       /* 230   100  "d" */ CWORD_CWORD_CWORD_CWORD,
-       /* 231   101  "e" */ CWORD_CWORD_CWORD_CWORD,
-       /* 232   102  "f" */ CWORD_CWORD_CWORD_CWORD,
-       /* 233   103  "g" */ CWORD_CWORD_CWORD_CWORD,
-       /* 234   104  "h" */ CWORD_CWORD_CWORD_CWORD,
-       /* 235   105  "i" */ CWORD_CWORD_CWORD_CWORD,
-       /* 236   106  "j" */ CWORD_CWORD_CWORD_CWORD,
-       /* 237   107  "k" */ CWORD_CWORD_CWORD_CWORD,
-       /* 238   108  "l" */ CWORD_CWORD_CWORD_CWORD,
-       /* 239   109  "m" */ CWORD_CWORD_CWORD_CWORD,
-       /* 240   110  "n" */ CWORD_CWORD_CWORD_CWORD,
-       /* 241   111  "o" */ CWORD_CWORD_CWORD_CWORD,
-       /* 242   112  "p" */ CWORD_CWORD_CWORD_CWORD,
-       /* 243   113  "q" */ CWORD_CWORD_CWORD_CWORD,
-       /* 244   114  "r" */ CWORD_CWORD_CWORD_CWORD,
-       /* 245   115  "s" */ CWORD_CWORD_CWORD_CWORD,
-       /* 246   116  "t" */ CWORD_CWORD_CWORD_CWORD,
-       /* 247   117  "u" */ CWORD_CWORD_CWORD_CWORD,
-       /* 248   118  "v" */ CWORD_CWORD_CWORD_CWORD,
-       /* 249   119  "w" */ CWORD_CWORD_CWORD_CWORD,
-       /* 250   120  "x" */ CWORD_CWORD_CWORD_CWORD,
-       /* 251   121  "y" */ CWORD_CWORD_CWORD_CWORD,
-       /* 252   122  "z" */ CWORD_CWORD_CWORD_CWORD,
-       /* 253   123  "{" */ CWORD_CWORD_CWORD_CWORD,
-       /* 254   124  "|" */ CSPCL_CWORD_CWORD_CWORD,
-       /* 255   125  "}" */ CENDVAR_CENDVAR_CWORD_CENDVAR,
-       /* 256   126  "~" */ CWORD_CCTL_CCTL_CWORD,
-       /* 257   127      */ CWORD_CWORD_CWORD_CWORD,
-};
-
-#endif  /* USE_SIT_FUNCTION */
-
-/*      alias.c      */
-
-
-#define ATABSIZE 39
-
-static int     funcblocksize;          /* size of structures in function */
-static int     funcstringsize;         /* size of strings in node */
-static pointer funcblock;              /* block to allocate function from */
-static char   *funcstring;             /* block to allocate strings from */
-
-static const short nodesize[26] = {
-      SHELL_ALIGN(sizeof (struct ncmd)),
-      SHELL_ALIGN(sizeof (struct npipe)),
-      SHELL_ALIGN(sizeof (struct nredir)),
-      SHELL_ALIGN(sizeof (struct nredir)),
-      SHELL_ALIGN(sizeof (struct nredir)),
-      SHELL_ALIGN(sizeof (struct nbinary)),
-      SHELL_ALIGN(sizeof (struct nbinary)),
-      SHELL_ALIGN(sizeof (struct nbinary)),
-      SHELL_ALIGN(sizeof (struct nif)),
-      SHELL_ALIGN(sizeof (struct nbinary)),
-      SHELL_ALIGN(sizeof (struct nbinary)),
-      SHELL_ALIGN(sizeof (struct nfor)),
-      SHELL_ALIGN(sizeof (struct ncase)),
-      SHELL_ALIGN(sizeof (struct nclist)),
-      SHELL_ALIGN(sizeof (struct narg)),
-      SHELL_ALIGN(sizeof (struct narg)),
-      SHELL_ALIGN(sizeof (struct nfile)),
-      SHELL_ALIGN(sizeof (struct nfile)),
-      SHELL_ALIGN(sizeof (struct nfile)),
-      SHELL_ALIGN(sizeof (struct nfile)),
-      SHELL_ALIGN(sizeof (struct nfile)),
-      SHELL_ALIGN(sizeof (struct ndup)),
-      SHELL_ALIGN(sizeof (struct ndup)),
-      SHELL_ALIGN(sizeof (struct nhere)),
-      SHELL_ALIGN(sizeof (struct nhere)),
-      SHELL_ALIGN(sizeof (struct nnot)),
-};
-
-
-static void calcsize(union node *);
-static void sizenodelist(struct nodelist *);
-static union node *copynode(union node *);
-static struct nodelist *copynodelist(struct nodelist *);
-static char *nodesavestr(char *);
-
-
-static int evalstring(char *, int mask);
-union node;     /* BLETCH for ansi C */
-static void evaltree(union node *, int);
-static void evalbackcmd(union node *, struct backcmd *);
-
-static int evalskip;                   /* set if we are skipping commands */
-static int skipcount;           /* number of levels to skip */
-static int funcnest;                   /* depth of function calls */
-
-/* reasons for skipping commands (see comment on breakcmd routine) */
-#define SKIPBREAK      (1 << 0)
-#define SKIPCONT       (1 << 1)
-#define SKIPFUNC       (1 << 2)
-#define SKIPFILE       (1 << 3)
-#define SKIPEVAL       (1 << 4)
-
-/*
- * This file was generated by the mkbuiltins program.
- */
-
-#if JOBS
-static int bgcmd(int, char **);
-#endif
-static int breakcmd(int, char **);
-static int cdcmd(int, char **);
-#ifdef CONFIG_ASH_CMDCMD
-static int commandcmd(int, char **);
-#endif
-static int dotcmd(int, char **);
-static int evalcmd(int, char **);
-#ifdef CONFIG_ASH_BUILTIN_ECHO
-static int echocmd(int, char **);
-#endif
-#ifdef CONFIG_ASH_BUILTIN_TEST
-static int testcmd(int, char **);
-#endif
-static int execcmd(int, char **);
-static int exitcmd(int, char **);
-static int exportcmd(int, char **);
-static int falsecmd(int, char **);
-#if JOBS
-static int fgcmd(int, char **);
-#endif
-#ifdef CONFIG_ASH_GETOPTS
-static int getoptscmd(int, char **);
-#endif
-static int hashcmd(int, char **);
-#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
-static int helpcmd(int argc, char **argv);
-#endif
-#if JOBS
-static int jobscmd(int, char **);
-#endif
-#ifdef CONFIG_ASH_MATH_SUPPORT
-static int letcmd(int, char **);
-#endif
-static int localcmd(int, char **);
-static int pwdcmd(int, char **);
-static int readcmd(int, char **);
-static int returncmd(int, char **);
-static int setcmd(int, char **);
-static int shiftcmd(int, char **);
-static int timescmd(int, char **);
-static int trapcmd(int, char **);
-static int truecmd(int, char **);
-static int typecmd(int, char **);
-static int umaskcmd(int, char **);
-static int unsetcmd(int, char **);
-static int waitcmd(int, char **);
-static int ulimitcmd(int, char **);
-#if JOBS
-static int killcmd(int, char **);
-#endif
-
-/*      mail.h        */
-
-#ifdef CONFIG_ASH_MAIL
-static void chkmail(void);
-static void changemail(const char *);
-#endif
-
-/*      exec.h    */
-
-/* values of cmdtype */
-#define CMDUNKNOWN      -1      /* no entry in table for command */
-#define CMDNORMAL       0       /* command is an executable program */
-#define CMDFUNCTION     1       /* command is a shell function */
-#define CMDBUILTIN      2       /* command is a shell builtin */
-
-struct builtincmd {
-       const char *name;
-       int (*builtin)(int, char **);
-       /* unsigned flags; */
-};
-
-
-#define COMMANDCMD (builtincmd + 5 + \
-       2 * ENABLE_ASH_BUILTIN_TEST + \
-       ENABLE_ASH_ALIAS + \
-       ENABLE_ASH_JOB_CONTROL)
-#define EXECCMD (builtincmd + 7 + \
-       2 * ENABLE_ASH_BUILTIN_TEST + \
-       ENABLE_ASH_ALIAS + \
-       ENABLE_ASH_JOB_CONTROL + \
-       ENABLE_ASH_CMDCMD + \
-       ENABLE_ASH_BUILTIN_ECHO)
-
-#define BUILTIN_NOSPEC  "0"
-#define BUILTIN_SPECIAL "1"
-#define BUILTIN_REGULAR "2"
-#define BUILTIN_SPEC_REG "3"
-#define BUILTIN_ASSIGN  "4"
-#define BUILTIN_SPEC_ASSG  "5"
-#define BUILTIN_REG_ASSG   "6"
-#define BUILTIN_SPEC_REG_ASSG   "7"
-
-#define IS_BUILTIN_SPECIAL(builtincmd) ((builtincmd)->name[0] & 1)
-#define IS_BUILTIN_REGULAR(builtincmd) ((builtincmd)->name[0] & 2)
-#define IS_BUILTIN_ASSIGN(builtincmd) ((builtincmd)->name[0] & 4)
-
-/* make sure to keep these in proper order since it is searched via bsearch() */
-static const struct builtincmd builtincmd[] = {
-       { BUILTIN_SPEC_REG      ".", dotcmd },
-       { BUILTIN_SPEC_REG      ":", truecmd },
-#ifdef CONFIG_ASH_BUILTIN_TEST
-       { BUILTIN_REGULAR       "[", testcmd },
-       { BUILTIN_REGULAR       "[[", testcmd },
-#endif
-#ifdef CONFIG_ASH_ALIAS
-       { BUILTIN_REG_ASSG      "alias", aliascmd },
-#endif
-#if JOBS
-       { BUILTIN_REGULAR       "bg", bgcmd },
-#endif
-       { BUILTIN_SPEC_REG      "break", breakcmd },
-       { BUILTIN_REGULAR       "cd", cdcmd },
-       { BUILTIN_NOSPEC        "chdir", cdcmd },
-#ifdef CONFIG_ASH_CMDCMD
-       { BUILTIN_REGULAR       "command", commandcmd },
-#endif
-       { BUILTIN_SPEC_REG      "continue", breakcmd },
-#ifdef CONFIG_ASH_BUILTIN_ECHO
-       { BUILTIN_REGULAR       "echo", echocmd },
-#endif
-       { BUILTIN_SPEC_REG      "eval", evalcmd },
-       { BUILTIN_SPEC_REG      "exec", execcmd },
-       { BUILTIN_SPEC_REG      "exit", exitcmd },
-       { BUILTIN_SPEC_REG_ASSG "export", exportcmd },
-       { BUILTIN_REGULAR       "false", falsecmd },
-#if JOBS
-       { BUILTIN_REGULAR       "fg", fgcmd },
-#endif
-#ifdef CONFIG_ASH_GETOPTS
-       { BUILTIN_REGULAR       "getopts", getoptscmd },
-#endif
-       { BUILTIN_NOSPEC        "hash", hashcmd },
-#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
-       { BUILTIN_NOSPEC        "help", helpcmd },
-#endif
-#if JOBS
-       { BUILTIN_REGULAR       "jobs", jobscmd },
-       { BUILTIN_REGULAR       "kill", killcmd },
-#endif
-#ifdef CONFIG_ASH_MATH_SUPPORT
-       { BUILTIN_NOSPEC        "let", letcmd },
-#endif
-       { BUILTIN_ASSIGN        "local", localcmd },
-       { BUILTIN_NOSPEC        "pwd", pwdcmd },
-       { BUILTIN_REGULAR       "read", readcmd },
-       { BUILTIN_SPEC_REG_ASSG "readonly", exportcmd },
-       { BUILTIN_SPEC_REG      "return", returncmd },
-       { BUILTIN_SPEC_REG      "set", setcmd },
-       { BUILTIN_SPEC_REG      "shift", shiftcmd },
-       { BUILTIN_SPEC_REG      "source", dotcmd },
-#ifdef CONFIG_ASH_BUILTIN_TEST
-       { BUILTIN_REGULAR       "test", testcmd },
-#endif
-       { BUILTIN_SPEC_REG      "times", timescmd },
-       { BUILTIN_SPEC_REG      "trap", trapcmd },
-       { BUILTIN_REGULAR       "true", truecmd },
-       { BUILTIN_NOSPEC        "type", typecmd },
-       { BUILTIN_NOSPEC        "ulimit", ulimitcmd },
-       { BUILTIN_REGULAR       "umask", umaskcmd },
-#ifdef CONFIG_ASH_ALIAS
-       { BUILTIN_REGULAR       "unalias", unaliascmd },
-#endif
-       { BUILTIN_SPEC_REG      "unset", unsetcmd },
-       { BUILTIN_REGULAR       "wait", waitcmd },
-};
-
-#define NUMBUILTINS  (sizeof (builtincmd) / sizeof (struct builtincmd) )
-
-static const char *safe_applets[] = { 
-       "[", "test", "echo", "cat",
-       "ln", "cp", "touch", "mkdir", "rm",
-       "cut", "hexdump", "awk", "sort",
-       "find", "xargs", "ls", "dd",
-       "chown", "chmod"
-};
-
-
-struct cmdentry {
-       int cmdtype;
-       union param {
-               int index;
-               const struct builtincmd *cmd;
-               struct funcnode *func;
-       } u;
-};
-
-
-/* action to find_command() */
-#define DO_ERR          0x01    /* prints errors */
-#define DO_ABS          0x02    /* checks absolute paths */
-#define DO_NOFUNC       0x04    /* don't return shell functions, for command */
-#define DO_ALTPATH      0x08    /* using alternate path */
-#define DO_ALTBLTIN     0x20    /* %builtin in alt. path */
-
-static const char *pathopt;     /* set by padvance */
-
-static void shellexec(char **, const char *, int)
-    ATTRIBUTE_NORETURN;
-static char *padvance(const char **, const char *);
-static void find_command(char *, struct cmdentry *, int, const char *);
-static struct builtincmd *find_builtin(const char *);
-static void hashcd(void);
-static void changepath(const char *);
-static void defun(char *, union node *);
-static void unsetfunc(const char *);
-
-#ifdef CONFIG_ASH_MATH_SUPPORT_64
-typedef int64_t arith_t;
-#define arith_t_type (long long)
-#else
-typedef long arith_t;
-#define arith_t_type (long)
-#endif
-
-#ifdef CONFIG_ASH_MATH_SUPPORT
-static arith_t dash_arith(const char *);
-static arith_t arith(const char *expr, int *perrcode);
-#endif
-
-#ifdef CONFIG_ASH_RANDOM_SUPPORT
-static unsigned long rseed;
-static void change_random(const char *);
-# ifndef DYNAMIC_VAR
-#  define DYNAMIC_VAR
-# endif
-#endif
-
-/*      init.h        */
-
-static void reset(void);
-
-/*      var.h     */
-
-/*
- * Shell variables.
- */
-
-/* flags */
-#define VEXPORT         0x01    /* variable is exported */
-#define VREADONLY       0x02    /* variable cannot be modified */
-#define VSTRFIXED       0x04    /* variable struct is statically allocated */
-#define VTEXTFIXED      0x08    /* text is statically allocated */
-#define VSTACK          0x10    /* text is allocated on the stack */
-#define VUNSET          0x20    /* the variable is not set */
-#define VNOFUNC         0x40    /* don't call the callback function */
-#define VNOSET          0x80    /* do not set variable - just readonly test */
-#define VNOSAVE         0x100   /* when text is on the heap before setvareq */
-#ifdef DYNAMIC_VAR
-# define VDYNAMIC        0x200   /* dynamic variable */
-# else
-# define VDYNAMIC        0
-#endif
-
-struct var {
-       struct var *next;               /* next entry in hash list */
-       int flags;                      /* flags are defined above */
-       const char *text;               /* name=value */
-       void (*func)(const char *);     /* function to be called when  */
-                                       /* the variable gets set/unset */
-};
-
-struct localvar {
-       struct localvar *next;          /* next local variable in list */
-       struct var *vp;                 /* the variable that was made local */
-       int flags;                      /* saved flags */
-       const char *text;               /* saved text */
-};
-
-
-static struct localvar *localvars;
-
-/*
- * Shell variables.
- */
-
-#ifdef CONFIG_ASH_GETOPTS
-static void getoptsreset(const char *);
-#endif
-
-#ifdef CONFIG_LOCALE_SUPPORT
-static void change_lc_all(const char *value);
-static void change_lc_ctype(const char *value);
-#endif
-
-
-#define VTABSIZE 39
-
-static const char defpathvar[] = "PATH=/usr/local/bin:/usr/bin:/sbin:/bin";
-#ifdef IFS_BROKEN
-static const char defifsvar[] = "IFS= \t\n";
-#define defifs (defifsvar + 4)
-#else
-static const char defifs[] = " \t\n";
-#endif
-
-
-static struct var varinit[] = {
-#ifdef IFS_BROKEN
-       { 0,    VSTRFIXED|VTEXTFIXED,           defifsvar,      0 },
-#else
-       { 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "IFS\0",        0 },
-#endif
-
-#ifdef CONFIG_ASH_MAIL
-       { 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL\0",       changemail },
-       { 0,    VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH\0",   changemail },
-#endif
-
-       { 0,    VSTRFIXED|VTEXTFIXED,           defpathvar,     changepath },
-       { 0,    VSTRFIXED|VTEXTFIXED,           "PS1=$ ",       0          },
-       { 0,    VSTRFIXED|VTEXTFIXED,           "PS2=> ",       0          },
-       { 0,    VSTRFIXED|VTEXTFIXED,           "PS4=+ ",       0          },
-#ifdef CONFIG_ASH_GETOPTS
-       { 0,    VSTRFIXED|VTEXTFIXED,           "OPTIND=1",     getoptsreset },
-#endif
-#ifdef CONFIG_ASH_RANDOM_SUPPORT
-       {0, VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
-#endif
-#ifdef CONFIG_LOCALE_SUPPORT
-       {0, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_ALL\0", change_lc_all },
-       {0, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_CTYPE\0", change_lc_ctype },
-#endif
-#ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY
-       {0, VSTRFIXED | VTEXTFIXED | VUNSET, "HISTFILE\0", NULL },
-#endif
-};
-
-#define vifs varinit[0]
-#ifdef CONFIG_ASH_MAIL
-#define vmail (&vifs)[1]
-#define vmpath (&vmail)[1]
-#else
-#define vmpath vifs
-#endif
-#define vpath (&vmpath)[1]
-#define vps1 (&vpath)[1]
-#define vps2 (&vps1)[1]
-#define vps4 (&vps2)[1]
-#define voptind (&vps4)[1]
-#ifdef CONFIG_ASH_GETOPTS
-#define vrandom (&voptind)[1]
-#else
-#define vrandom (&vps4)[1]
-#endif
-#define defpath (defpathvar + 5)
-
-/*
- * The following macros access the values of the above variables.
- * They have to skip over the name.  They return the null string
- * for unset variables.
- */
-
-#define ifsval()        (vifs.text + 4)
-#define ifsset()        ((vifs.flags & VUNSET) == 0)
-#define mailval()       (vmail.text + 5)
-#define mpathval()      (vmpath.text + 9)
-#define pathval()       (vpath.text + 5)
-#define ps1val()        (vps1.text + 4)
-#define ps2val()        (vps2.text + 4)
-#define ps4val()        (vps4.text + 4)
-#define optindval()     (voptind.text + 7)
-
-#define mpathset()      ((vmpath.flags & VUNSET) == 0)
-
-static void setvar(const char *, const char *, int);
-static void setvareq(char *, int);
-static void listsetvar(struct strlist *, int);
-static char *lookupvar(const char *);
-static char *bltinlookup(const char *);
-static char **listvars(int, int, char ***);
-#define environment() listvars(VEXPORT, VUNSET, 0)
-static int showvars(const char *, int, int);
-static void poplocalvars(void);
-static int unsetvar(const char *);
-#ifdef CONFIG_ASH_GETOPTS
-static int setvarsafe(const char *, const char *, int);
-#endif
-static int varcmp(const char *, const char *);
-static struct var **hashvar(const char *);
-
-
-static int varequal(const char *a, const char *b) {
-       return !varcmp(a, b);
-}
-
-
-static int loopnest;            /* current loop nesting level */
-
-/*
- * The parsefile structure pointed to by the global variable parsefile
- * contains information about the current file being read.
- */
-
-
-struct redirtab {
-       struct redirtab *next;
-       int renamed[10];
-       int nullredirs;
-};
-
-static struct redirtab *redirlist;
-static int nullredirs;
-
-extern char **environ;
-
-/*      output.h     */
-
-
-static void outstr(const char *, FILE *);
-static void outcslow(int, FILE *);
-static void flushall(void);
-static void flusherr(void);
-static int  out1fmt(const char *, ...)
-    __attribute__((__format__(__printf__,1,2)));
-static int fmtstr(char *, size_t, const char *, ...)
-    __attribute__((__format__(__printf__,3,4)));
-
-static int preverrout_fd;   /* save fd2 before print debug if xflag is set. */
-
-
-static void out1str(const char *p)
-{
-       outstr(p, stdout);
-}
-
-static void out2str(const char *p)
-{
-       outstr(p, stderr);
-       flusherr();
-}
-
-/*
- * Initialization code.
- */
-
-/*
- * This routine initializes the builtin variables.
- */
-
-static void initvar(void)
-{
-       struct var *vp;
-       struct var *end;
-       struct var **vpp;
-
-       /*
-        * PS1 depends on uid
-        */
-#if defined(CONFIG_FEATURE_COMMAND_EDITING) && defined(CONFIG_FEATURE_SH_FANCY_PROMPT)
-       vps1.text = "PS1=\\w \\$ ";
-#else
-       if (!geteuid())
-               vps1.text = "PS1=# ";
-#endif
-       vp = varinit;
-       end = vp + sizeof(varinit) / sizeof(varinit[0]);
-       do {
-               vpp = hashvar(vp->text);
-               vp->next = *vpp;
-               *vpp = vp;
-       } while (++vp < end);
-}
-
-static void init(void)
-{
-
-      /* from input.c: */
-      {
-             basepf.nextc = basepf.buf = basebuf;
-      }
-
-      /* from trap.c: */
-      {
-             signal(SIGCHLD, SIG_DFL);
-      }
-
-      /* from var.c: */
-      {
-             char **envp;
-             char ppid[32];
-             const char *p;
-             struct stat st1, st2;
-
-             initvar();
-             for (envp = environ ; envp && *envp ; envp++) {
-                     if (strchr(*envp, '=')) {
-                             setvareq(*envp, VEXPORT|VTEXTFIXED);
-                     }
-             }
-
-             snprintf(ppid, sizeof(ppid), "%d", (int) getppid());
-             setvar("PPID", ppid, 0);
-
-             p = lookupvar("PWD");
-             if (p)
-             if (*p != '/' || stat(p, &st1) || stat(".", &st2) ||
-                 st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
-                     p = 0;
-             setpwd(p, 0);
-      }
-}
-
-/* PEOF (the end of file marker) */
-
-enum {
-       INPUT_PUSH_FILE = 1,
-       INPUT_NOFILE_OK = 2,
-};
-
-/*
- * The input line number.  Input.c just defines this variable, and saves
- * and restores it when files are pushed and popped.  The user of this
- * package must set its value.
- */
-
-static int pgetc(void);
-static int pgetc2(void);
-static int preadbuffer(void);
-static void pungetc(void);
-static void pushstring(char *, void *);
-static void popstring(void);
-static void setinputfd(int, int);
-static void setinputstring(char *);
-static void popfile(void);
-static void popallfiles(void);
-static void closescript(void);
-
-
-/*      jobs.h    */
-
-
-/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
-#define FORK_FG 0
-#define FORK_BG 1
-#define FORK_NOJOB 2
-
-/* mode flags for showjob(s) */
-#define SHOW_PGID       0x01    /* only show pgid - for jobs -p */
-#define SHOW_PID        0x04    /* include process pid */
-#define SHOW_CHANGED    0x08    /* only jobs whose state has changed */
-
-
-/*
- * A job structure contains information about a job.  A job is either a
- * single process or a set of processes contained in a pipeline.  In the
- * latter case, pidlist will be non-NULL, and will point to a -1 terminated
- * array of pids.
- */
-
-struct procstat {
-       pid_t   pid;            /* process id */
-       int     status;         /* last process status from wait() */
-       char    *cmd;           /* text of command being run */
-};
-
-struct job {
-       struct procstat ps0;    /* status of process */
-       struct procstat *ps;    /* status or processes when more than one */
-#if JOBS
-       int stopstatus;         /* status of a stopped job */
-#endif
-       uint32_t
-               nprocs: 16,     /* number of processes */
-               state: 8,
-#define JOBRUNNING      0       /* at least one proc running */
-#define JOBSTOPPED      1       /* all procs are stopped */
-#define JOBDONE         2       /* all procs are completed */
-#if JOBS
-               sigint: 1,      /* job was killed by SIGINT */
-               jobctl: 1,      /* job running under job control */
-#endif
-               waited: 1,      /* true if this entry has been waited for */
-               used: 1,        /* true if this entry is in used */
-               changed: 1;     /* true if status has changed */
-       struct job *prev_job;   /* previous job */
-};
-
-static pid_t backgndpid;        /* pid of last background process */
-static int job_warning;         /* user was warned about stopped jobs */
-#if JOBS
-static int jobctl;              /* true if doing job control */
-#endif
-
-static struct job *makejob(union node *, int);
-static int forkshell(struct job *, union node *, int);
-static int waitforjob(struct job *);
-static int stoppedjobs(void);
-
-#if ! JOBS
-#define setjobctl(on)   /* do nothing */
-#else
-static void setjobctl(int);
-static void showjobs(FILE *, int);
-#endif
-
-/*      main.h        */
-
-
-/* pid of main shell */
-static int rootpid;
-/* shell level: 0 for the main shell, 1 for its children, and so on */
-static int shlvl;
-#define rootshell (!shlvl)
-
-static void readcmdfile(char *);
-static int cmdloop(int);
-
-/*      memalloc.h        */
-
-
-struct stackmark {
-       struct stack_block *stackp;
-       char *stacknxt;
-       size_t stacknleft;
-       struct stackmark *marknext;
-};
-
-/* minimum size of a block */
-#define MINSIZE SHELL_ALIGN(504)
-
-struct stack_block {
-       struct stack_block *prev;
-       char space[MINSIZE];
-};
-
-static struct stack_block stackbase;
-static struct stack_block *stackp = &stackbase;
-static struct stackmark *markp;
-static char *stacknxt = stackbase.space;
-static size_t stacknleft = MINSIZE;
-static char *sstrend = stackbase.space + MINSIZE;
-static int herefd = -1;
-
-
-static pointer ckmalloc(size_t);
-static pointer ckrealloc(pointer, size_t);
-static char *savestr(const char *);
-static pointer stalloc(size_t);
-static void stunalloc(pointer);
-static void setstackmark(struct stackmark *);
-static void popstackmark(struct stackmark *);
-static void growstackblock(void);
-static void *growstackstr(void);
-static char *makestrspace(size_t, char *);
-static char *stnputs(const char *, size_t, char *);
-static char *stputs(const char *, char *);
-
-
-static char *_STPUTC(int c, char *p) {
-       if (p == sstrend)
-               p = growstackstr();
-       *p++ = c;
-       return p;
-}
-
-#define stackblock() ((void *)stacknxt)
-#define stackblocksize() stacknleft
-#define STARTSTACKSTR(p) ((p) = stackblock())
-#define STPUTC(c, p) ((p) = _STPUTC((c), (p)))
-#define CHECKSTRSPACE(n, p) \
-       ({ \
-               char *q = (p); \
-               size_t l = (n); \
-               size_t m = sstrend - q; \
-               if (l > m) \
-                       (p) = makestrspace(l, q); \
-               0; \
-       })
-#define USTPUTC(c, p)   (*p++ = (c))
-#define STACKSTRNUL(p)  ((p) == sstrend? (p = growstackstr(), *p = '\0') : (*p = '\0'))
-#define STUNPUTC(p)     (--p)
-#define STTOPC(p)       p[-1]
-#define STADJUST(amount, p)     (p += (amount))
-
-#define grabstackstr(p) stalloc((char *)(p) - (char *)stackblock())
-#define ungrabstackstr(s, p) stunalloc((s))
-#define stackstrend() ((void *)sstrend)
-
-#define ckfree(p)       free((pointer)(p))
-
-/*      mystring.h   */
-
-
-#define DOLATSTRLEN 4
-
-static char *prefix(const char *, const char *);
-static int number(const char *);
-static int is_number(const char *);
-static char *single_quote(const char *);
-static char *sstrdup(const char *);
-
-#define equal(s1, s2)   (strcmp(s1, s2) == 0)
-#define scopy(s1, s2)   ((void)strcpy(s2, s1))
-
-/*      options.h */
-
-struct shparam {
-       int nparam;             /* # of positional parameters (without $0) */
-       unsigned char malloc;   /* if parameter list dynamically allocated */
-       char **p;               /* parameter list */
-#ifdef CONFIG_ASH_GETOPTS
-       int optind;             /* next parameter to be processed by getopts */
-       int optoff;             /* used by getopts */
-#endif
-};
-
-
-#define eflag optlist[0]
-#define fflag optlist[1]
-#define Iflag optlist[2]
-#define iflag optlist[3]
-#define mflag optlist[4]
-#define nflag optlist[5]
-#define sflag optlist[6]
-#define xflag optlist[7]
-#define vflag optlist[8]
-#define Cflag optlist[9]
-#define aflag optlist[10]
-#define bflag optlist[11]
-#define uflag optlist[12]
-#define viflag optlist[13]
-
-#if DEBUG
-#define nolog optlist[14]
-#define debug optlist[15]
-#endif
-
-#ifndef CONFIG_FEATURE_COMMAND_EDITING_VI
-#define setvimode(on) viflag = 0   /* forcibly keep the option off */
-#endif
-
-/*      options.c */
-
-
-static const char *const optletters_optnames[] = {
-       "e"   "errexit",
-       "f"   "noglob",
-       "I"   "ignoreeof",
-       "i"   "interactive",
-       "m"   "monitor",
-       "n"   "noexec",
-       "s"   "stdin",
-       "x"   "xtrace",
-       "v"   "verbose",
-       "C"   "noclobber",
-       "a"   "allexport",
-       "b"   "notify",
-       "u"   "nounset",
-       "\0"  "vi",
-#if DEBUG
-       "\0"  "nolog",
-       "\0"  "debug",
-#endif
-};
-
-#define optletters(n) optletters_optnames[(n)][0]
-#define optnames(n) (&optletters_optnames[(n)][1])
-
-#define NOPTS (sizeof(optletters_optnames)/sizeof(optletters_optnames[0]))
-
-static char optlist[NOPTS];
-
-
-static char *arg0;                     /* value of $0 */
-static struct shparam shellparam;      /* $@ current positional parameters */
-static char **argptr;                  /* argument list for builtin commands */
-static char *optionarg;                /* set by nextopt (like getopt) */
-static char *optptr;                   /* used by nextopt */
-
-static char *minusc;                   /* argument to -c option */
-
-
-static void procargs(int, char **);
-static void optschanged(void);
-static void setparam(char **);
-static void freeparam(volatile struct shparam *);
-static int shiftcmd(int, char **);
-static int setcmd(int, char **);
-static int nextopt(const char *);
-
-/*      redir.h      */
-
-/* flags passed to redirect */
-#define REDIR_PUSH 01           /* save previous values of file descriptors */
-#define REDIR_SAVEFD2 03       /* set preverrout */
-
-union node;
-static void redirect(union node *, int);
-static void popredir(int);
-static void clearredir(int);
-static int copyfd(int, int);
-static int redirectsafe(union node *, int);
-
-/*      show.h     */
-
-
-#if DEBUG
-static void showtree(union node *);
-static void trace(const char *, ...);
-static void tracev(const char *, va_list);
-static void trargs(char **);
-static void trputc(int);
-static void trputs(const char *);
-static void opentrace(void);
-#endif
-
-/*      trap.h       */
-
-
-/* trap handler commands */
-static char *trap[NSIG];
-/* current value of signal */
-static char sigmode[NSIG - 1];
-/* indicates specified signal received */
-static char gotsig[NSIG - 1];
-
-static void clear_traps(void);
-static void setsignal(int);
-static void ignoresig(int);
-static void onsig(int);
-static int dotrap(void);
-static void setinteractive(int);
-static void exitshell(void) ATTRIBUTE_NORETURN;
-
-
-static int is_safe_applet(char *name)
-{
-       int n = sizeof(safe_applets) / sizeof(char *);
-       int i;
-       for (i = 0; i < n; i++)
-               if (strcmp(safe_applets[i], name) == 0)
-                       return 1;
-
-       return 0;
-}
-
-
-/*
- * This routine is called when an error or an interrupt occurs in an
- * interactive shell and control is returned to the main command loop.
- */
-
-static void
-reset(void)
-{
-      /* from eval.c: */
-      {
-             evalskip = 0;
-             loopnest = 0;
-      }
-
-      /* from input.c: */
-      {
-             parselleft = parsenleft = 0;      /* clear input buffer */
-             popallfiles();
-      }
-
-      /* from parser.c: */
-      {
-             tokpushback = 0;
-             checkkwd = 0;
-      }
-
-      /* from redir.c: */
-      {
-             clearredir(0);
-      }
-
-}
-
-#ifdef CONFIG_ASH_ALIAS
-static struct alias *atab[ATABSIZE];
-
-static void setalias(const char *, const char *);
-static struct alias *freealias(struct alias *);
-static struct alias **__lookupalias(const char *);
-
-static void
-setalias(const char *name, const char *val)
-{
-       struct alias *ap, **app;
-
-       app = __lookupalias(name);
-       ap = *app;
-       INTOFF;
-       if (ap) {
-               if (!(ap->flag & ALIASINUSE)) {
-                       ckfree(ap->val);
-               }
-               ap->val = savestr(val);
-               ap->flag &= ~ALIASDEAD;
-       } else {
-               /* not found */
-               ap = ckmalloc(sizeof (struct alias));
-               ap->name = savestr(name);
-               ap->val = savestr(val);
-               ap->flag = 0;
-               ap->next = 0;
-               *app = ap;
-       }
-       INTON;
-}
-
-static int
-unalias(const char *name)
-{
-       struct alias **app;
-
-       app = __lookupalias(name);
-
-       if (*app) {
-               INTOFF;
-               *app = freealias(*app);
-               INTON;
-               return 0;
-       }
-
-       return 1;
-}
-
-static void
-rmaliases(void)
-{
-       struct alias *ap, **app;
-       int i;
-
-       INTOFF;
-       for (i = 0; i < ATABSIZE; i++) {
-               app = &atab[i];
-               for (ap = *app; ap; ap = *app) {
-                       *app = freealias(*app);
-                       if (ap == *app) {
-                               app = &ap->next;
-                       }
-               }
-       }
-       INTON;
-}
-
-static struct alias *
-lookupalias(const char *name, int check)
-{
-       struct alias *ap = *__lookupalias(name);
-
-       if (check && ap && (ap->flag & ALIASINUSE))
-               return NULL;
-       return ap;
-}
-
-/*
- * TODO - sort output
- */
-static int
-aliascmd(int argc, char **argv)
-{
-       char *n, *v;
-       int ret = 0;
-       struct alias *ap;
-
-       if (argc == 1) {
-               int i;
-
-               for (i = 0; i < ATABSIZE; i++)
-                       for (ap = atab[i]; ap; ap = ap->next) {
-                               printalias(ap);
-                       }
-               return 0;
-       }
-       while ((n = *++argv) != NULL) {
-               if ((v = strchr(n+1, '=')) == NULL) { /* n+1: funny ksh stuff */
-                       if ((ap = *__lookupalias(n)) == NULL) {
-                               fprintf(stderr, "%s: %s not found\n", "alias", n);
-                               ret = 1;
-                       } else
-                               printalias(ap);
-               } else {
-                       *v++ = '\0';
-                       setalias(n, v);
-               }
-       }
-
-       return ret;
-}
-
-static int
-unaliascmd(int argc, char **argv)
-{
-       int i;
-
-       while ((i = nextopt("a")) != '\0') {
-               if (i == 'a') {
-                       rmaliases();
-                       return 0;
-               }
-       }
-       for (i = 0; *argptr; argptr++) {
-               if (unalias(*argptr)) {
-                       fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
-                       i = 1;
-               }
-       }
-
-       return i;
-}
-
-static struct alias *
-freealias(struct alias *ap) {
-       struct alias *next;
-
-       if (ap->flag & ALIASINUSE) {
-               ap->flag |= ALIASDEAD;
-               return ap;
-       }
-
-       next = ap->next;
-       ckfree(ap->name);
-       ckfree(ap->val);
-       ckfree(ap);
-       return next;
-}
-
-static void
-printalias(const struct alias *ap) {
-       out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
-}
-
-static struct alias **
-__lookupalias(const char *name) {
-       unsigned int hashval;
-       struct alias **app;
-       const char *p;
-       unsigned int ch;
-
-       p = name;
-
-       ch = (unsigned char)*p;
-       hashval = ch << 4;
-       while (ch) {
-               hashval += ch;
-               ch = (unsigned char)*++p;
-       }
-       app = &atab[hashval % ATABSIZE];
-
-       for (; *app; app = &(*app)->next) {
-               if (equal(name, (*app)->name)) {
-                       break;
-               }
-       }
-
-       return app;
-}
-#endif /* CONFIG_ASH_ALIAS */
-
-
-/*      cd.c      */
-
-/*
- * The cd and pwd commands.
- */
-
-#define CD_PHYSICAL 1
-#define CD_PRINT 2
-
-static int docd(const char *, int);
-static int cdopt(void);
-
-static char *curdir = nullstr;          /* current working directory */
-static char *physdir = nullstr;         /* physical working directory */
-
-static int
-cdopt(void)
-{
-       int flags = 0;
-       int i, j;
-
-       j = 'L';
-       while ((i = nextopt("LP"))) {
-               if (i != j) {
-                       flags ^= CD_PHYSICAL;
-                       j = i;
-               }
-       }
-
-       return flags;
-}
-
-static int
-cdcmd(int argc, char **argv)
-{
-       const char *dest;
-       const char *path;
-       const char *p;
-       char c;
-       struct stat statb;
-       int flags;
-
-       flags = cdopt();
-       dest = *argptr;
-       if (!dest)
-               dest = bltinlookup(homestr);
-       else if (dest[0] == '-' && dest[1] == '\0') {
-               dest = bltinlookup("OLDPWD");
-               flags |= CD_PRINT;
-       }
-       if (!dest)
-               dest = nullstr;
-       if (*dest == '/')
-               goto step7;
-       if (*dest == '.') {
-               c = dest[1];
-dotdot:
-               switch (c) {
-               case '\0':
-               case '/':
-                       goto step6;
-               case '.':
-                       c = dest[2];
-                       if (c != '.')
-                               goto dotdot;
-               }
-       }
-       if (!*dest)
-               dest = ".";
-       if (!(path = bltinlookup("CDPATH"))) {
-step6:
-step7:
-               p = dest;
-               goto docd;
-       }
-       do {
-               c = *path;
-               p = padvance(&path, dest);
-               if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
-                       if (c && c != ':')
-                               flags |= CD_PRINT;
-docd:
-                       if (!docd(p, flags))
-                               goto out;
-                       break;
-               }
-       } while (path);
-       sh_error("can't cd to %s", dest);
-       /* NOTREACHED */
-out:
-       if (flags & CD_PRINT)
-               out1fmt(snlfmt, curdir);
-       return 0;
-}
-
-
-/*
- * Update curdir (the name of the current directory) in response to a
- * cd command.
- */
-
-static const char * updatepwd(const char *dir)
-{
-       char *new;
-       char *p;
-       char *cdcomppath;
-       const char *lim;
-
-       cdcomppath = sstrdup(dir);
-       STARTSTACKSTR(new);
-       if (*dir != '/') {
-               if (curdir == nullstr)
-                       return 0;
-               new = stputs(curdir, new);
-       }
-       new = makestrspace(strlen(dir) + 2, new);
-       lim = stackblock() + 1;
-       if (*dir != '/') {
-               if (new[-1] != '/')
-                       USTPUTC('/', new);
-               if (new > lim && *lim == '/')
-                       lim++;
-       } else {
-               USTPUTC('/', new);
-               cdcomppath++;
-               if (dir[1] == '/' && dir[2] != '/') {
-                       USTPUTC('/', new);
-                       cdcomppath++;
-                       lim++;
-               }
-       }
-       p = strtok(cdcomppath, "/");
-       while (p) {
-               switch(*p) {
-               case '.':
-                       if (p[1] == '.' && p[2] == '\0') {
-                               while (new > lim) {
-                                       STUNPUTC(new);
-                                       if (new[-1] == '/')
-                                               break;
-                               }
-                               break;
-                       } else if (p[1] == '\0')
-                               break;
-                       /* fall through */
-               default:
-                       new = stputs(p, new);
-                       USTPUTC('/', new);
-               }
-               p = strtok(0, "/");
-       }
-       if (new > lim)
-               STUNPUTC(new);
-       *new = 0;
-       return stackblock();
-}
-
-/*
- * Actually do the chdir.  We also call hashcd to let the routines in exec.c
- * know that the current directory has changed.
- */
-
-static int
-docd(const char *dest, int flags)
-{
-       const char *dir = 0;
-       int err;
-
-       TRACE(("docd(\"%s\", %d) called\n", dest, flags));
-
-       INTOFF;
-       if (!(flags & CD_PHYSICAL)) {
-               dir = updatepwd(dest);
-               if (dir)
-                       dest = dir;
-       }
-       err = chdir(dest);
-       if (err)
-               goto out;
-       setpwd(dir, 1);
-       hashcd();
-out:
-       INTON;
-       return err;
-}
-
-/*
- * Find out what the current directory is. If we already know the current
- * directory, this routine returns immediately.
- */
-static char * getpwd(void)
-{
-       char *dir = getcwd(0, 0);
-       return dir ? dir : nullstr;
-}
-
-static int
-pwdcmd(int argc, char **argv)
-{
-       int flags;
-       const char *dir = curdir;
-
-       flags = cdopt();
-       if (flags) {
-               if (physdir == nullstr)
-                       setpwd(dir, 0);
-               dir = physdir;
-       }
-       out1fmt(snlfmt, dir);
-       return 0;
-}
-
-static void
-setpwd(const char *val, int setold)
-{
-       char *oldcur, *dir;
-
-       oldcur = dir = curdir;
-
-       if (setold) {
-               setvar("OLDPWD", oldcur, VEXPORT);
-       }
-       INTOFF;
-       if (physdir != nullstr) {
-               if (physdir != oldcur)
-                       free(physdir);
-               physdir = nullstr;
-       }
-       if (oldcur == val || !val) {
-               char *s = getpwd();
-               physdir = s;
-               if (!val)
-                       dir = s;
-       } else
-               dir = savestr(val);
-       if (oldcur != dir && oldcur != nullstr) {
-               free(oldcur);
-       }
-       curdir = dir;
-       INTON;
-       setvar("PWD", dir, VEXPORT);
-}
-
-/*      error.c   */
-
-/*
- * Errors and exceptions.
- */
-
-/*
- * Code to handle exceptions in C.
- */
-
-
-
-static void exverror(int, const char *, va_list)
-    ATTRIBUTE_NORETURN;
-
-/*
- * Called to raise an exception.  Since C doesn't include exceptions, we
- * just do a longjmp to the exception handler.  The type of exception is
- * stored in the global variable "exception".
- */
-
-static void
-exraise(int e)
-{
-#if DEBUG
-       if (handler == NULL)
-               abort();
-#endif
-       INTOFF;
-
-       exception = e;
-       longjmp(handler->loc, 1);
-}
-
-
-/*
- * Called from trap.c when a SIGINT is received.  (If the user specifies
- * that SIGINT is to be trapped or ignored using the trap builtin, then
- * this routine is not called.)  Suppressint is nonzero when interrupts
- * are held using the INTOFF macro.  (The test for iflag is just
- * defensive programming.)
- */
-
-static void
-onint(void) {
-       int i;
-
-       intpending = 0;
-       i = EXSIG;
-       if (gotsig[SIGINT - 1] && !trap[SIGINT]) {
-               if (!(rootshell && iflag)) {
-                       signal(SIGINT, SIG_DFL);
-                       raise(SIGINT);
-               }
-               i = EXINT;
-       }
-       exraise(i);
-       /* NOTREACHED */
-}
-
-static void
-exvwarning(const char *msg, va_list ap)
-{
-        FILE *errs;
-
-        errs = stderr;
-        fprintf(errs, "%s: ", arg0);
-        if (commandname) {
-                const char *fmt = (!iflag || parsefile->fd) ?
-                                       "%s: %d: " : "%s: ";
-                fprintf(errs, fmt, commandname, startlinno);
-        }
-        vfprintf(errs, msg, ap);
-        outcslow('\n', errs);
-}
-
-/*
- * Exverror is called to raise the error exception.  If the second argument
- * is not NULL then error prints an error message using printf style
- * formatting.  It then raises the error exception.
- */
-static void
-exverror(int cond, const char *msg, va_list ap)
-{
-#if DEBUG
-       if (msg) {
-               TRACE(("exverror(%d, \"", cond));
-               TRACEV((msg, ap));
-               TRACE(("\") pid=%d\n", getpid()));
-       } else
-               TRACE(("exverror(%d, NULL) pid=%d\n", cond, getpid()));
-       if (msg)
-#endif
-               exvwarning(msg, ap);
-
-       flushall();
-       exraise(cond);
-       /* NOTREACHED */
-}
-
-
-static void
-sh_error(const char *msg, ...)
-{
-       va_list ap;
-
-       va_start(ap, msg);
-       exverror(EXERROR, msg, ap);
-       /* NOTREACHED */
-       va_end(ap);
-}
-
-
-static void
-exerror(int cond, const char *msg, ...)
-{
-       va_list ap;
-
-       va_start(ap, msg);
-       exverror(cond, msg, ap);
-       /* NOTREACHED */
-       va_end(ap);
-}
-
-/*
- * error/warning routines for external builtins
- */
-
-static void
-sh_warnx(const char *fmt, ...)
-{
-       va_list ap;
-
-       va_start(ap, fmt);
-       exvwarning(fmt, ap);
-       va_end(ap);
-}
-
-
-/*
- * Return a string describing an error.  The returned string may be a
- * pointer to a static buffer that will be overwritten on the next call.
- * Action describes the operation that got the error.
- */
-
-static const char *
-errmsg(int e, const char *em)
-{
-       if(e == ENOENT || e == ENOTDIR) {
-
-               return em;
-       }
-       return strerror(e);
-}
-
-
-/*      eval.c  */
-
-/*
- * Evaluate a command.
- */
-
-/* flags in argument to evaltree */
-#define EV_EXIT 01              /* exit after evaluating tree */
-#define EV_TESTED 02            /* exit status is checked; ignore -e flag */
-#define EV_BACKCMD 04           /* command executing within back quotes */
-
-
-static void evalloop(union node *, int);
-static void evalfor(union node *, int);
-static void evalcase(union node *, int);
-static void evalsubshell(union node *, int);
-static void expredir(union node *);
-static void evalpipe(union node *, int);
-static void evalcommand(union node *, int);
-static int evalbltin(const struct builtincmd *, int, char **);
-static int evalfun(struct funcnode *, int, char **, int);
-static void prehash(union node *);
-static int bltincmd(int, char **);
-
-
-static const struct builtincmd bltin = {
-       "\0\0", bltincmd
-};
-
-
-/*
- * Called to reset things after an exception.
- */
-
-/*
- * The eval command.
- */
-
-static int
-evalcmd(int argc, char **argv)
-{
-       char *p;
-       char *concat;
-       char **ap;
-
-       if (argc > 1) {
-               p = argv[1];
-               if (argc > 2) {
-                       STARTSTACKSTR(concat);
-                       ap = argv + 2;
-                       for (;;) {
-                               concat = stputs(p, concat);
-                               if ((p = *ap++) == NULL)
-                                       break;
-                               STPUTC(' ', concat);
-                       }
-                       STPUTC('\0', concat);
-                       p = grabstackstr(concat);
-               }
-               evalstring(p, ~SKIPEVAL);
-
-       }
-       return exitstatus;
-}
-
-
-/*
- * Execute a command or commands contained in a string.
- */
-
-static int
-evalstring(char *s, int mask)
-{
-       union node *n;
-       struct stackmark smark;
-       int skip;
-
-       setinputstring(s);
-       setstackmark(&smark);
-
-       skip = 0;
-       while ((n = parsecmd(0)) != NEOF) {
-               evaltree(n, 0);
-               popstackmark(&smark);
-               skip = evalskip;
-               if (skip)
-                       break;
-       }
-       popfile();
-
-       skip &= mask;
-       evalskip = skip;
-       return skip;
-}
-
-
-
-/*
- * Evaluate a parse tree.  The value is left in the global variable
- * exitstatus.
- */
-
-static void
-evaltree(union node *n, int flags)
-{
-       int checkexit = 0;
-       void (*evalfn)(union node *, int);
-       unsigned isor;
-       int status;
-       if (n == NULL) {
-               TRACE(("evaltree(NULL) called\n"));
-               goto out;
-       }
-       TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
-           getpid(), n, n->type, flags));
-       switch (n->type) {
-       default:
-#if DEBUG
-               out1fmt("Node type = %d\n", n->type);
-               fflush(stdout);
-               break;
-#endif
-       case NNOT:
-               evaltree(n->nnot.com, EV_TESTED);
-               status = !exitstatus;
-               goto setstatus;
-       case NREDIR:
-               expredir(n->nredir.redirect);
-               status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
-               if (!status) {
-                       evaltree(n->nredir.n, flags & EV_TESTED);
-                       status = exitstatus;
-               }
-               popredir(0);
-               goto setstatus;
-       case NCMD:
-               evalfn = evalcommand;
-checkexit:
-               if (eflag && !(flags & EV_TESTED))
-                       checkexit = ~0;
-               goto calleval;
-       case NFOR:
-               evalfn = evalfor;
-               goto calleval;
-       case NWHILE:
-       case NUNTIL:
-               evalfn = evalloop;
-               goto calleval;
-       case NSUBSHELL:
-       case NBACKGND:
-               evalfn = evalsubshell;
-               goto calleval;
-       case NPIPE:
-               evalfn = evalpipe;
-               goto checkexit;
-       case NCASE:
-               evalfn = evalcase;
-               goto calleval;
-       case NAND:
-       case NOR:
-       case NSEMI:
-#if NAND + 1 != NOR
-#error NAND + 1 != NOR
-#endif
-#if NOR + 1 != NSEMI
-#error NOR + 1 != NSEMI
-#endif
-               isor = n->type - NAND;
-               evaltree(
-                       n->nbinary.ch1,
-                       (flags | ((isor >> 1) - 1)) & EV_TESTED
-               );
-               if (!exitstatus == isor)
-                       break;
-               if (!evalskip) {
-                       n = n->nbinary.ch2;
-evaln:
-                       evalfn = evaltree;
-calleval:
-                       evalfn(n, flags);
-                       break;
-               }
-               break;
-       case NIF:
-               evaltree(n->nif.test, EV_TESTED);
-               if (evalskip)
-                       break;
-               if (exitstatus == 0) {
-                       n = n->nif.ifpart;
-                       goto evaln;
-               } else if (n->nif.elsepart) {
-                       n = n->nif.elsepart;
-                       goto evaln;
-               }
-               goto success;
-       case NDEFUN:
-               defun(n->narg.text, n->narg.next);
-success:
-               status = 0;
-setstatus:
-               exitstatus = status;
-               break;
-       }
-out:
-       if ((checkexit & exitstatus))
-               evalskip |= SKIPEVAL;
-       else if (pendingsigs && dotrap())
-               goto exexit;
-
-       if (flags & EV_EXIT) {
-exexit:
-               exraise(EXEXIT);
-       }
-}
-
-
-#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
-static
-#endif
-void evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__));
-
-
-static void
-evalloop(union node *n, int flags)
-{
-       int status;
-
-       loopnest++;
-       status = 0;
-       flags &= EV_TESTED;
-       for (;;) {
-               int i;
-
-               evaltree(n->nbinary.ch1, EV_TESTED);
-               if (evalskip) {
-skipping:         if (evalskip == SKIPCONT && --skipcount <= 0) {
-                               evalskip = 0;
-                               continue;
-                       }
-                       if (evalskip == SKIPBREAK && --skipcount <= 0)
-                               evalskip = 0;
-                       break;
-               }
-               i = exitstatus;
-               if (n->type != NWHILE)
-                       i = !i;
-               if (i != 0)
-                       break;
-               evaltree(n->nbinary.ch2, flags);
-               status = exitstatus;
-               if (evalskip)
-                       goto skipping;
-       }
-       loopnest--;
-       exitstatus = status;
-}
-
-
-
-static void
-evalfor(union node *n, int flags)
-{
-       struct arglist arglist;
-       union node *argp;
-       struct strlist *sp;
-       struct stackmark smark;
-
-       setstackmark(&smark);
-       arglist.lastp = &arglist.list;
-       for (argp = n->nfor.args ; argp ; argp = argp->narg.next) {
-               expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD);
-               /* XXX */
-               if (evalskip)
-                       goto out;
-       }
-       *arglist.lastp = NULL;
-
-       exitstatus = 0;
-       loopnest++;
-       flags &= EV_TESTED;
-       for (sp = arglist.list ; sp ; sp = sp->next) {
-               setvar(n->nfor.var, sp->text, 0);
-               evaltree(n->nfor.body, flags);
-               if (evalskip) {
-                       if (evalskip == SKIPCONT && --skipcount <= 0) {
-                               evalskip = 0;
-                               continue;
-                       }
-                       if (evalskip == SKIPBREAK && --skipcount <= 0)
-                               evalskip = 0;
-                       break;
-               }
-       }
-       loopnest--;
-out:
-       popstackmark(&smark);
-}
-
-
-
-static void
-evalcase(union node *n, int flags)
-{
-       union node *cp;
-       union node *patp;
-       struct arglist arglist;
-       struct stackmark smark;
-
-       setstackmark(&smark);
-       arglist.lastp = &arglist.list;
-       expandarg(n->ncase.expr, &arglist, EXP_TILDE);
-       exitstatus = 0;
-       for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) {
-               for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) {
-                       if (casematch(patp, arglist.list->text)) {
-                               if (evalskip == 0) {
-                                       evaltree(cp->nclist.body, flags);
-                               }
-                               goto out;
-                       }
-               }
-       }
-out:
-       popstackmark(&smark);
-}
-
-
-
-/*
- * Kick off a subshell to evaluate a tree.
- */
-
-static void
-evalsubshell(union node *n, int flags)
-{
-       struct job *jp;
-       int backgnd = (n->type == NBACKGND);
-       int status;
-
-       expredir(n->nredir.redirect);
-       if (!backgnd && flags & EV_EXIT && !trap[0])
-               goto nofork;
-       INTOFF;
-       jp = makejob(n, 1);
-       if (forkshell(jp, n, backgnd) == 0) {
-               INTON;
-               flags |= EV_EXIT;
-               if (backgnd)
-                       flags &=~ EV_TESTED;
-nofork:
-               redirect(n->nredir.redirect, 0);
-               evaltreenr(n->nredir.n, flags);
-               /* never returns */
-       }
-       status = 0;
-       if (! backgnd)
-               status = waitforjob(jp);
-       exitstatus = status;
-       INTON;
-}
-
-
-
-/*
- * Compute the names of the files in a redirection list.
- */
-
-static void
-expredir(union node *n)
-{
-       union node *redir;
-
-       for (redir = n ; redir ; redir = redir->nfile.next) {
-               struct arglist fn;
-               memset(&fn, 0, sizeof(struct arglist));
-               fn.lastp = &fn.list;
-               switch (redir->type) {
-               case NFROMTO:
-               case NFROM:
-               case NTO:
-               case NCLOBBER:
-               case NAPPEND:
-                       expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
-                       redir->nfile.expfname = fn.list->text;
-                       break;
-               case NFROMFD:
-               case NTOFD:
-                       if (redir->ndup.vname) {
-                               expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
-                               if (fn.list != NULL)
-                                       fixredir(redir, fn.list->text, 1);
-                               else
-                                       sh_error("redir error");
-                       }
-                       break;
-               }
-       }
-}
-
-
-
-/*
- * Evaluate a pipeline.  All the processes in the pipeline are children
- * of the process creating the pipeline.  (This differs from some versions
- * of the shell, which make the last process in a pipeline the parent
- * of all the rest.)
- */
-
-static void
-evalpipe(union node *n, int flags)
-{
-       struct job *jp;
-       struct nodelist *lp;
-       int pipelen;
-       int prevfd;
-       int pip[2];
-
-       TRACE(("evalpipe(0x%lx) called\n", (long)n));
-       pipelen = 0;
-       for (lp = n->npipe.cmdlist ; lp ; lp = lp->next)
-               pipelen++;
-       flags |= EV_EXIT;
-       INTOFF;
-       jp = makejob(n, pipelen);
-       prevfd = -1;
-       for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
-               prehash(lp->n);
-               pip[1] = -1;
-               if (lp->next) {
-                       if (pipe(pip) < 0) {
-                               close(prevfd);
-                               sh_error("Pipe call failed");
-                       }
-               }
-               if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
-                       INTON;
-                       if (pip[1] >= 0) {
-                               close(pip[0]);
-                       }
-                       if (prevfd > 0) {
-                               dup2(prevfd, 0);
-                               close(prevfd);
-                       }
-                       if (pip[1] > 1) {
-                               dup2(pip[1], 1);
-                               close(pip[1]);
-                       }
-                       evaltreenr(lp->n, flags);
-                       /* never returns */
-               }
-               if (prevfd >= 0)
-                       close(prevfd);
-               prevfd = pip[0];
-               close(pip[1]);
-       }
-       if (n->npipe.backgnd == 0) {
-               exitstatus = waitforjob(jp);
-               TRACE(("evalpipe:  job done exit status %d\n", exitstatus));
-       }
-       INTON;
-}
-
-
-
-/*
- * Execute a command inside back quotes.  If it's a builtin command, we
- * want to save its output in a block obtained from malloc.  Otherwise
- * we fork off a subprocess and get the output of the command via a pipe.
- * Should be called with interrupts off.
- */
-
-static void
-evalbackcmd(union node *n, struct backcmd *result)
-{
-       int saveherefd;
-
-       result->fd = -1;
-       result->buf = NULL;
-       result->nleft = 0;
-       result->jp = NULL;
-       if (n == NULL) {
-               goto out;
-       }
-
-       saveherefd = herefd;
-       herefd = -1;
-
-       {
-               int pip[2];
-               struct job *jp;
-
-               if (pipe(pip) < 0)
-                       sh_error("Pipe call failed");
-               jp = makejob(n, 1);
-               if (forkshell(jp, n, FORK_NOJOB) == 0) {
-                       FORCEINTON;
-                       close(pip[0]);
-                       if (pip[1] != 1) {
-                               close(1);
-                               copyfd(pip[1], 1);
-                               close(pip[1]);
-                       }
-                       eflag = 0;
-                       evaltreenr(n, EV_EXIT);
-                       /* NOTREACHED */
-               }
-               close(pip[1]);
-               result->fd = pip[0];
-               result->jp = jp;
-       }
-       herefd = saveherefd;
-out:
-       TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
-               result->fd, result->buf, result->nleft, result->jp));
-}
-
-#ifdef CONFIG_ASH_CMDCMD
-static char ** parse_command_args(char **argv, const char **path)
-{
-       char *cp, c;
-
-       for (;;) {
-               cp = *++argv;
-               if (!cp)
-                       return 0;
-               if (*cp++ != '-')
-                       break;
-               if (!(c = *cp++))
-                       break;
-               if (c == '-' && !*cp) {
-                       argv++;
-                       break;
-               }
-               do {
-                       switch (c) {
-                       case 'p':
-                               *path = defpath;
-                               break;
-                       default:
-                               /* run 'typecmd' for other options */
-                               return 0;
-                       }
-               } while ((c = *cp++));
-       }
-       return argv;
-}
-#endif
-
-static int isassignment(const char *p)
-{
-       const char *q = endofname(p);
-       if (p == q)
-               return 0;
-       return *q == '=';
-}
-
-#ifdef CONFIG_ASH_EXPAND_PRMT
-static const char *expandstr(const char *ps);
-#else
-#define expandstr(s) s
-#endif
-
-/*
- * Execute a simple command.
- */
-
-static void
-evalcommand(union node *cmd, int flags)
-{
-       struct stackmark smark;
-       union node *argp;
-       struct arglist arglist;
-       struct arglist varlist;
-       char **argv;
-       int argc;
-       const struct strlist *sp;
-       struct cmdentry cmdentry;
-       struct job *jp;
-       char *lastarg;
-       const char *path;
-       int spclbltin;
-       int cmd_is_exec;
-       int status;
-       char **nargv;
-       struct builtincmd *bcmd;
-       int pseudovarflag = 0;
-
-       /* First expand the arguments. */
-       TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
-       setstackmark(&smark);
-       back_exitstatus = 0;
-
-       cmdentry.cmdtype = CMDBUILTIN;
-       cmdentry.u.cmd = &bltin;
-       varlist.lastp = &varlist.list;
-       *varlist.lastp = NULL;
-       arglist.lastp = &arglist.list;
-       *arglist.lastp = NULL;
-
-       argc = 0;
-       if (cmd->ncmd.args)
-       {
-               bcmd = find_builtin(cmd->ncmd.args->narg.text);
-               pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd);
-       }
-
-       for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
-               struct strlist **spp;
-
-               spp = arglist.lastp;
-               if (pseudovarflag && isassignment(argp->narg.text))
-                       expandarg(argp, &arglist, EXP_VARTILDE);
-               else
-                       expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
-
-               for (sp = *spp; sp; sp = sp->next)
-                       argc++;
-       }
-
-       argv = nargv = stalloc(sizeof (char *) * (argc + 1));
-       for (sp = arglist.list ; sp ; sp = sp->next) {
-               TRACE(("evalcommand arg: %s\n", sp->text));
-               *nargv++ = sp->text;
-       }
-       *nargv = NULL;
-
-       lastarg = NULL;
-       if (iflag && funcnest == 0 && argc > 0)
-               lastarg = nargv[-1];
-
-       preverrout_fd = 2;
-       expredir(cmd->ncmd.redirect);
-       status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH|REDIR_SAVEFD2);
-
-       path = vpath.text;
-       for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
-               struct strlist **spp;
-               char *p;
-
-               spp = varlist.lastp;
-               expandarg(argp, &varlist, EXP_VARTILDE);
-
-               /*
-                * Modify the command lookup path, if a PATH= assignment
-                * is present
-                */
-               p = (*spp)->text;
-               if (varequal(p, path))
-                       path = p;
-       }
-
-       /* Print the command if xflag is set. */
-       if (xflag) {
-               int n;
-               const char *p = " %s";
-
-               p++;
-               dprintf(preverrout_fd, p, expandstr(ps4val()));
-
-               sp = varlist.list;
-               for(n = 0; n < 2; n++) {
-                       while (sp) {
-                               dprintf(preverrout_fd, p, sp->text);
-                               sp = sp->next;
-                               if(*p == '%') {
-                                       p--;
-                               }
-                       }
-                       sp = arglist.list;
-               }
-               full_write(preverrout_fd, "\n", 1);
-       }
-
-       cmd_is_exec = 0;
-       spclbltin = -1;
-
-       /* Now locate the command. */
-       if (argc) {
-               const char *oldpath;
-               int cmd_flag = DO_ERR;
-
-               path += 5;
-               oldpath = path;
-               for (;;) {
-                       find_command(argv[0], &cmdentry, cmd_flag, path);
-                       if (cmdentry.cmdtype == CMDUNKNOWN) {
-                               status = 127;
-                               flusherr();
-                               goto bail;
-                       }
+                       if (subtype & VSNUL)
+                               putc(':', fp);
 
-                       /* implement bltin and command here */
-                       if (cmdentry.cmdtype != CMDBUILTIN)
+                       switch (subtype & VSTYPE) {
+                       case VSNORMAL:
+                               putc('}', fp);
                                break;
-                       if (spclbltin < 0)
-                               spclbltin = IS_BUILTIN_SPECIAL(cmdentry.u.cmd);
-                       if (cmdentry.u.cmd == EXECCMD)
-                               cmd_is_exec++;
-#ifdef CONFIG_ASH_CMDCMD
-                       if (cmdentry.u.cmd == COMMANDCMD) {
-
-                               path = oldpath;
-                               nargv = parse_command_args(argv, &path);
-                               if (!nargv)
-                                       break;
-                               argc -= nargv - argv;
-                               argv = nargv;
-                               cmd_flag |= DO_NOFUNC;
-                       } else
-#endif
+                       case VSMINUS:
+                               putc('-', fp);
                                break;
-               }
-       }
-
-       if (status) {
-               /* We have a redirection error. */
-               if (spclbltin > 0)
-                       exraise(EXERROR);
-bail:
-               exitstatus = status;
-               goto out;
-       }
-
-       /* Execute the command. */
-       switch (cmdentry.cmdtype) {
-       default:
-               /* Fork off a child process if necessary. */
-               if (!(flags & EV_EXIT) || trap[0]) {
-                       INTOFF;
-                       jp = makejob(cmd, 1);
-                       if (forkshell(jp, cmd, FORK_FG) != 0) {
-                               exitstatus = waitforjob(jp);
-                               INTON;
+                       case VSPLUS:
+                               putc('+', fp);
                                break;
+                       case VSQUESTION:
+                               putc('?', fp);
+                               break;
+                       case VSASSIGN:
+                               putc('=', fp);
+                               break;
+                       case VSTRIMLEFT:
+                               putc('#', fp);
+                               break;
+                       case VSTRIMLEFTMAX:
+                               putc('#', fp);
+                               putc('#', fp);
+                               break;
+                       case VSTRIMRIGHT:
+                               putc('%', fp);
+                               break;
+                       case VSTRIMRIGHTMAX:
+                               putc('%', fp);
+                               putc('%', fp);
+                               break;
+                       case VSLENGTH:
+                               break;
+                       default:
+                               out1fmt("<subtype %d>", subtype);
                        }
-                       FORCEINTON;
-               }
-               listsetvar(varlist.list, VEXPORT|VSTACK);
-               shellexec(argv, path, cmdentry.u.index);
-               /* NOTREACHED */
-
-       case CMDBUILTIN:
-               cmdenviron = varlist.list;
-               if (cmdenviron) {
-                       struct strlist *list = cmdenviron;
-                       int i = VNOSET;
-                       if (spclbltin > 0 || argc == 0) {
-                               i = 0;
-                               if (cmd_is_exec && argc > 1)
-                                       i = VEXPORT;
-                       }
-                       listsetvar(list, i);
-               }
-               if (evalbltin(cmdentry.u.cmd, argc, argv)) {
-                       int exit_status;
-                       int i, j;
-
-                       i = exception;
-                       if (i == EXEXIT)
-                               goto raise;
-
-                       exit_status = 2;
-                       j = 0;
-                       if (i == EXINT)
-                               j = SIGINT;
-                       if (i == EXSIG)
-                               j = pendingsigs;
-                       if (j)
-                               exit_status = j + 128;
-                       exitstatus = exit_status;
-
-                       if (i == EXINT || spclbltin > 0) {
-raise:
-                               longjmp(handler->loc, 1);
-                       }
-                       FORCEINTON;
+                       break;
+               case CTLENDVAR:
+                       putc('}', fp);
+                       break;
+               case CTLBACKQ:
+               case CTLBACKQ|CTLQUOTE:
+                       putc('$', fp);
+                       putc('(', fp);
+                       shtree(bqlist->n, -1, NULL, fp);
+                       putc(')', fp);
+                       break;
+               default:
+                       putc(*p, fp);
+                       break;
                }
-               break;
-
-       case CMDFUNCTION:
-               listsetvar(varlist.list, 0);
-               if (evalfun(cmdentry.u.func, argc, argv, flags))
-                       goto raise;
-               break;
        }
-
-out:
-       popredir(cmd_is_exec);
-       if (lastarg)
-               /* dsl: I think this is intended to be used to support
-                * '_' in 'vi' command mode during line editing...
-                * However I implemented that within libedit itself.
-                */
-               setvar("_", lastarg, 0);
-       popstackmark(&smark);
-}
-
-static int
-evalbltin(const struct builtincmd *cmd, int argc, char **argv) {
-       char *volatile savecmdname;
-       struct jmploc *volatile savehandler;
-       struct jmploc jmploc;
-       int i;
-
-       savecmdname = commandname;
-       if ((i = setjmp(jmploc.loc)))
-               goto cmddone;
-       savehandler = handler;
-       handler = &jmploc;
-       commandname = argv[0];
-       argptr = argv + 1;
-       optptr = NULL;                  /* initialize nextopt */
-       exitstatus = (*cmd->builtin)(argc, argv);
-       flushall();
-cmddone:
-       exitstatus |= ferror(stdout);
-       clearerr(stdout);
-       commandname = savecmdname;
-       exsig = 0;
-       handler = savehandler;
-
-       return i;
 }
 
-static int
-evalfun(struct funcnode *func, int argc, char **argv, int flags)
+static void
+shcmd(union node *cmd, FILE *fp)
 {
-       volatile struct shparam saveparam;
-       struct localvar *volatile savelocalvars;
-       struct jmploc *volatile savehandler;
-       struct jmploc jmploc;
-       int e;
+       union node *np;
+       int first;
+       const char *s;
+       int dftfd;
 
-       saveparam = shellparam;
-       savelocalvars = localvars;
-       if ((e = setjmp(jmploc.loc))) {
-               goto funcdone;
+       first = 1;
+       for (np = cmd->ncmd.args; np; np = np->narg.next) {
+               if (!first)
+                       putc(' ', fp);
+               sharg(np, fp);
+               first = 0;
+       }
+       for (np = cmd->ncmd.redirect; np; np = np->nfile.next) {
+               if (!first)
+                       putc(' ', fp);
+               dftfd = 0;
+               switch (np->nfile.type) {
+               case NTO:      s = ">>"+1; dftfd = 1; break;
+               case NCLOBBER: s = ">|"; dftfd = 1; break;
+               case NAPPEND:  s = ">>"; dftfd = 1; break;
+               case NTOFD:    s = ">&"; dftfd = 1; break;
+               case NFROM:    s = "<";  break;
+               case NFROMFD:  s = "<&"; break;
+               case NFROMTO:  s = "<>"; break;
+               default:       s = "*error*"; break;
+               }
+               if (np->nfile.fd != dftfd)
+                       fprintf(fp, "%d", np->nfile.fd);
+               fputs(s, fp);
+               if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
+                       fprintf(fp, "%d", np->ndup.dupfd);
+               } else {
+                       sharg(np->nfile.fname, fp);
+               }
+               first = 0;
        }
-       INTOFF;
-       savehandler = handler;
-       handler = &jmploc;
-       localvars = NULL;
-       shellparam.malloc = 0;
-       func->count++;
-       funcnest++;
-       INTON;
-       shellparam.nparam = argc - 1;
-       shellparam.p = argv + 1;
-#ifdef CONFIG_ASH_GETOPTS
-       shellparam.optind = 1;
-       shellparam.optoff = -1;
-#endif
-       evaltree(&func->n, flags & EV_TESTED);
-funcdone:
-       INTOFF;
-       funcnest--;
-       freefunc(func);
-       poplocalvars();
-       localvars = savelocalvars;
-       freeparam(&shellparam);
-       shellparam = saveparam;
-       handler = savehandler;
-       INTON;
-       evalskip &= ~SKIPFUNC;
-       return e;
 }
 
-
-static int goodname(const char *p)
+static void
+shtree(union node *n, int ind, char *pfx, FILE *fp)
 {
-       return !*endofname(p);
-}
+       struct nodelist *lp;
+       const char *s;
 
-/*
- * Search for a command.  This is called before we fork so that the
- * location of the command will be available in the parent as well as
- * the child.  The check for "goodname" is an overly conservative
- * check that the name will not be subject to expansion.
- */
+       if (n == NULL)
+               return;
+
+       indent(ind, pfx, fp);
+       switch (n->type) {
+       case NSEMI:
+               s = "; ";
+               goto binop;
+       case NAND:
+               s = " && ";
+               goto binop;
+       case NOR:
+               s = " || ";
+ binop:
+               shtree(n->nbinary.ch1, ind, NULL, fp);
+               /* if (ind < 0) */
+                       fputs(s, fp);
+               shtree(n->nbinary.ch2, ind, NULL, fp);
+               break;
+       case NCMD:
+               shcmd(n, fp);
+               if (ind >= 0)
+                       putc('\n', fp);
+               break;
+       case NPIPE:
+               for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
+                       shcmd(lp->n, fp);
+                       if (lp->next)
+                               fputs(" | ", fp);
+               }
+               if (n->npipe.backgnd)
+                       fputs(" &", fp);
+               if (ind >= 0)
+                       putc('\n', fp);
+               break;
+       default:
+               fprintf(fp, "<node type %d>", n->type);
+               if (ind >= 0)
+                       putc('\n', fp);
+               break;
+       }
+}
 
 static void
-prehash(union node *n)
+showtree(union node *n)
 {
-       struct cmdentry entry;
-
-       if (n->type == NCMD && n->ncmd.args)
-               if (goodname(n->ncmd.args->narg.text))
-                       find_command(n->ncmd.args->narg.text, &entry, 0,
-                                    pathval());
+       trace_puts("showtree called\n");
+       shtree(n, 1, NULL, stdout);
 }
 
+#define TRACE(param)    trace_printf param
+#define TRACEV(param)   trace_vprintf param
 
+#else
 
-/*
- * Builtin commands.  Builtin commands whose functions are closely
- * tied to evaluation are implemented here.
- */
+#define TRACE(param)
+#define TRACEV(param)
 
-/*
- * No command given.
- */
+#endif /* DEBUG */
 
-static int
-bltincmd(int argc, char **argv)
-{
-       /*
-        * Preserve exitstatus of a previous possible redirection
-        * as POSIX mandates
-        */
-       return back_exitstatus;
-}
 
+/* ============ Parser data */
 
 /*
- * Handle break and continue commands.  Break, continue, and return are
- * all handled by setting the evalskip flag.  The evaluation routines
- * above all check this flag, and if it is set they start skipping
- * commands rather than executing them.  The variable skipcount is
- * the number of loops to break/continue, or the number of function
- * levels to return.  (The latter is always 1.)  It should probably
- * be an error to break out of more loops than exist, but it isn't
- * in the standard shell so we don't make it one here.
+ * ash_vmsg() needs parsefile->fd, hence parsefile definition is moved up.
  */
+struct strlist {
+       struct strlist *next;
+       char *text;
+};
 
-static int
-breakcmd(int argc, char **argv)
-{
-       int n = argc > 1 ? number(argv[1]) : 1;
+#if ENABLE_ASH_ALIAS
+struct alias;
+#endif
 
-       if (n <= 0)
-               sh_error(illnum, argv[1]);
-       if (n > loopnest)
-               n = loopnest;
-       if (n > 0) {
-               evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK;
-               skipcount = n;
+struct strpush {
+       struct strpush *prev;   /* preceding string on stack */
+       char *prevstring;
+       int prevnleft;
+#if ENABLE_ASH_ALIAS
+       struct alias *ap;       /* if push was associated with an alias */
+#endif
+       char *string;           /* remember the string since it may change */
+};
+
+struct parsefile {
+       struct parsefile *prev; /* preceding file on stack */
+       int linno;              /* current line */
+       int fd;                 /* file descriptor (or -1 if string) */
+       int nleft;              /* number of chars left in this line */
+       int lleft;              /* number of chars left in this buffer */
+       char *nextc;            /* next char in buffer */
+       char *buf;              /* input buffer */
+       struct strpush *strpush; /* for pushing strings at this level */
+       struct strpush basestrpush; /* so pushing one is fast */
+};
+
+static struct parsefile basepf;         /* top level input file */
+static struct parsefile *parsefile = &basepf;  /* current input file */
+static int startlinno;                 /* line # where last token started */
+static char *commandname;              /* currently executing command */
+static struct strlist *cmdenviron;     /* environment for builtin command */
+static int exitstatus;                 /* exit status of last command */
+
+
+/* ============ Message printing */
+
+static void
+ash_vmsg(const char *msg, va_list ap)
+{
+       fprintf(stderr, "%s: ", arg0);
+       if (commandname) {
+               if (strcmp(arg0, commandname))
+                       fprintf(stderr, "%s: ", commandname);
+               if (!iflag || parsefile->fd)
+                       fprintf(stderr, "line %d: ", startlinno);
        }
-       return 0;
+       vfprintf(stderr, msg, ap);
+       outcslow('\n', stderr);
 }
 
-
 /*
- * The return command.
+ * Exverror is called to raise the error exception.  If the second argument
+ * is not NULL then error prints an error message using printf style
+ * formatting.  It then raises the error exception.
  */
-
-static int
-returncmd(int argc, char **argv)
+static void ash_vmsg_and_raise(int, const char *, va_list) ATTRIBUTE_NORETURN;
+static void
+ash_vmsg_and_raise(int cond, const char *msg, va_list ap)
 {
-       /*
-        * If called outside a function, do what ksh does;
-        * skip the rest of the file.
-        */
-       evalskip = funcnest ? SKIPFUNC : SKIPFILE;
-       return argv[1] ? number(argv[1]) : exitstatus;
-}
+#if DEBUG
+       if (msg) {
+               TRACE(("ash_vmsg_and_raise(%d, \"", cond));
+               TRACEV((msg, ap));
+               TRACE(("\") pid=%d\n", getpid()));
+       } else
+               TRACE(("ash_vmsg_and_raise(%d, NULL) pid=%d\n", cond, getpid()));
+       if (msg)
+#endif
+               ash_vmsg(msg, ap);
 
+       flush_stdout_stderr();
+       raise_exception(cond);
+       /* NOTREACHED */
+}
 
-static int
-falsecmd(int argc, char **argv)
+static void ash_msg_and_raise_error(const char *, ...) ATTRIBUTE_NORETURN;
+static void
+ash_msg_and_raise_error(const char *msg, ...)
 {
-       return 1;
-}
+       va_list ap;
 
+       va_start(ap, msg);
+       ash_vmsg_and_raise(EXERROR, msg, ap);
+       /* NOTREACHED */
+       va_end(ap);
+}
 
-static int
-truecmd(int argc, char **argv)
+static void ash_msg_and_raise(int, const char *, ...) ATTRIBUTE_NORETURN;
+static void
+ash_msg_and_raise(int cond, const char *msg, ...)
 {
-       return 0;
+       va_list ap;
+
+       va_start(ap, msg);
+       ash_vmsg_and_raise(cond, msg, ap);
+       /* NOTREACHED */
+       va_end(ap);
 }
 
+/*
+ * error/warning routines for external builtins
+ */
+static void
+ash_msg(const char *fmt, ...)
+{
+       va_list ap;
 
-static int
-execcmd(int argc, char **argv)
+       va_start(ap, fmt);
+       ash_vmsg(fmt, ap);
+       va_end(ap);
+}
+
+/*
+ * Return a string describing an error.  The returned string may be a
+ * pointer to a static buffer that will be overwritten on the next call.
+ * Action describes the operation that got the error.
+ */
+static const char *
+errmsg(int e, const char *em)
 {
-       if (argc > 1) {
-               iflag = 0;              /* exit on error */
-               mflag = 0;
-               optschanged();
-               shellexec(argv + 1, pathval(), 0);
+       if (e == ENOENT || e == ENOTDIR) {
+               return em;
        }
-       return 0;
+       return strerror(e);
 }
 
 
-/*      exec.c    */
+/* ============ Memory allocation */
 
 /*
- * When commands are first encountered, they are entered in a hash table.
- * This ensures that a full path search will not have to be done for them
- * on each invocation.
- *
- * We should investigate converting to a linear search, even though that
- * would make the command name "hash" a misnomer.
+ * It appears that grabstackstr() will barf with such alignments
+ * because stalloc() will return a string allocated in a new stackblock.
  */
+#define SHELL_ALIGN(nbytes) (((nbytes) + SHELL_SIZE) & ~SHELL_SIZE)
+enum {
+       /* Most machines require the value returned from malloc to be aligned
+        * in some way.  The following macro will get this right
+        * on many machines.  */
+       SHELL_SIZE = sizeof(union {int i; char *cp; double d; }) - 1,
+       /* Minimum size of a block */
+       MINSIZE  = SHELL_ALIGN(504),
+};
 
-#define CMDTABLESIZE 31         /* should be prime */
-#define ARB 1                   /* actual size determined at run time */
-
-
-
-struct tblentry {
-       struct tblentry *next;  /* next entry in hash chain */
-       union param param;      /* definition of builtin function */
-       short cmdtype;          /* index identifying command */
-       char rehash;            /* if set, cd done since entry created */
-       char cmdname[ARB];      /* name of command */
+struct stack_block {
+       struct stack_block *prev;
+       char space[MINSIZE];
 };
 
+struct stackmark {
+       struct stack_block *stackp;
+       char *stacknxt;
+       size_t stacknleft;
+       struct stackmark *marknext;
+};
 
-static struct tblentry *cmdtable[CMDTABLESIZE];
-static int builtinloc = -1;             /* index in path of %builtin, or -1 */
+static struct stack_block stackbase;
+static struct stack_block *stackp = &stackbase;
+static struct stackmark *markp;
+static char *stacknxt = stackbase.space;
+static size_t stacknleft = MINSIZE;
+static char *sstrend = stackbase.space + MINSIZE;
+static int herefd = -1;
 
+#define stackblock() ((void *)stacknxt)
+#define stackblocksize() stacknleft
 
-static void tryexec(char *, char **, char **);
-static void clearcmdentry(int);
-static struct tblentry *cmdlookup(const char *, int);
-static void delete_cmd_entry(void);
+static void *
+ckrealloc(void * p, size_t nbytes)
+{
+       p = realloc(p, nbytes);
+       if (!p)
+               ash_msg_and_raise_error(bb_msg_memory_exhausted);
+       return p;
+}
 
+static void *
+ckmalloc(size_t nbytes)
+{
+       return ckrealloc(NULL, nbytes);
+}
 
 /*
- * Exec a program.  Never returns.  If you change this routine, you may
- * have to change the find_command routine as well.
+ * Make a copy of a string in safe storage.
  */
+static char *
+ckstrdup(const char *s)
+{
+       char *p = strdup(s);
+       if (!p)
+               ash_msg_and_raise_error(bb_msg_memory_exhausted);
+       return p;
+}
 
-static void
-shellexec(char **argv, const char *path, int idx)
+/*
+ * Parse trees for commands are allocated in lifo order, so we use a stack
+ * to make this more efficient, and also to avoid all sorts of exception
+ * handling code to handle interrupts in the middle of a parse.
+ *
+ * The size 504 was chosen because the Ultrix malloc handles that size
+ * well.
+ */
+static void *
+stalloc(size_t nbytes)
 {
-       char *cmdname;
-       int e;
-       char **envp;
-       int exerrno;
+       char *p;
+       size_t aligned;
 
-       clearredir(1);
-       envp = environment();
-       if (strchr(argv[0], '/') != NULL
-               || is_safe_applet(argv[0])
-#ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
-               || find_applet_by_name(argv[0])
-#endif
-                                               ) {
-               tryexec(argv[0], argv, envp);
-               e = errno;
-       } else {
-               e = ENOENT;
-               while ((cmdname = padvance(&path, argv[0])) != NULL) {
-                       if (--idx < 0 && pathopt == NULL) {
-                               tryexec(cmdname, argv, envp);
-                               if (errno != ENOENT && errno != ENOTDIR)
-                                       e = errno;
-                       }
-                       stunalloc(cmdname);
-               }
-       }
+       aligned = SHELL_ALIGN(nbytes);
+       if (aligned > stacknleft) {
+               size_t len;
+               size_t blocksize;
+               struct stack_block *sp;
 
-       /* Map to POSIX errors */
-       switch (e) {
-       case EACCES:
-               exerrno = 126;
-               break;
-       case ENOENT:
-               exerrno = 127;
-               break;
-       default:
-               exerrno = 2;
-               break;
+               blocksize = aligned;
+               if (blocksize < MINSIZE)
+                       blocksize = MINSIZE;
+               len = sizeof(struct stack_block) - MINSIZE + blocksize;
+               if (len < blocksize)
+                       ash_msg_and_raise_error(bb_msg_memory_exhausted);
+               INT_OFF;
+               sp = ckmalloc(len);
+               sp->prev = stackp;
+               stacknxt = sp->space;
+               stacknleft = blocksize;
+               sstrend = stacknxt + blocksize;
+               stackp = sp;
+               INT_ON;
        }
-       exitstatus = exerrno;
-       TRACE(("shellexec failed for %s, errno %d, suppressint %d\n",
-               argv[0], e, suppressint ));
-       exerror(EXEXEC, "%s: %s", argv[0], errmsg(e, E_EXEC));
-       /* NOTREACHED */
+       p = stacknxt;
+       stacknxt += aligned;
+       stacknleft -= aligned;
+       return p;
 }
 
-
 static void
-tryexec(char *cmd, char **argv, char **envp)
+stunalloc(void *p)
 {
-       int repeated = 0;
-       struct BB_applet *a;
-       int argc = 0;
-       char **c;
-       
-       if(strchr(cmd, '/') == NULL && is_safe_applet(cmd) && (a = find_applet_by_name(cmd)) != NULL) {
-               c = argv;
-               while (*c != NULL) {
-                       c++; argc++;
-               }
-               applet_name = cmd;
-               exit(a->main(argc, argv));
-       }
-#ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
-       if(find_applet_by_name(cmd) != NULL) {
-               /* re-exec ourselves with the new arguments */
-               execve(CONFIG_BUSYBOX_EXEC_PATH,argv,envp);
-               /* If they called chroot or otherwise made the binary no longer
-                * executable, fall through */
+#if DEBUG
+       if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) {
+               write(2, "stunalloc\n", 10);
+               abort();
        }
 #endif
-
-repeat:
-#ifdef SYSV
-       do {
-               execve(cmd, argv, envp);
-       } while (errno == EINTR);
-#else
-       execve(cmd, argv, envp);
-#endif
-       if (repeated++) {
-               ckfree(argv);
-       } else if (errno == ENOEXEC) {
-               char **ap;
-               char **new;
-
-               for (ap = argv; *ap; ap++)
-                       ;
-               ap = new = ckmalloc((ap - argv + 2) * sizeof(char *));
-               ap[1] = cmd;
-               *ap = cmd = (char *)DEFAULT_SHELL;
-               ap += 2;
-               argv++;
-               while ((*ap++ = *argv++))
-                       ;
-               argv = new;
-               goto repeat;
-       }
+       stacknleft += stacknxt - (char *)p;
+       stacknxt = p;
 }
 
-
-
 /*
- * Do a path search.  The variable path (passed by reference) should be
- * set to the start of the path before the first call; padvance will update
- * this value as it proceeds.  Successive calls to padvance will return
- * the possible path expansions in sequence.  If an option (indicated by
- * a percent sign) appears in the path entry then the global variable
- * pathopt will be set to point to it; otherwise pathopt will be set to
- * NULL.
+ * Like strdup but works with the ash stack.
  */
-
 static char *
-padvance(const char **path, const char *name)
+ststrdup(const char *p)
 {
-       const char *p;
-       char *q;
-       const char *start;
-       size_t len;
+       size_t len = strlen(p) + 1;
+       return memcpy(stalloc(len), p, len);
+}
 
-       if (*path == NULL)
-               return NULL;
-       start = *path;
-       for (p = start ; *p && *p != ':' && *p != '%' ; p++);
-       len = p - start + strlen(name) + 2;     /* "2" is for '/' and '\0' */
-       while (stackblocksize() < len)
-               growstackblock();
-       q = stackblock();
-       if (p != start) {
-               memcpy(q, start, p - start);
-               q += p - start;
-               *q++ = '/';
-       }
-       strcpy(q, name);
-       pathopt = NULL;
-       if (*p == '%') {
-               pathopt = ++p;
-               while (*p && *p != ':')  p++;
-       }
-       if (*p == ':')
-               *path = p + 1;
-       else
-               *path = NULL;
-       return stalloc(len);
+static void
+setstackmark(struct stackmark *mark)
+{
+       mark->stackp = stackp;
+       mark->stacknxt = stacknxt;
+       mark->stacknleft = stacknleft;
+       mark->marknext = markp;
+       markp = mark;
 }
 
+static void
+popstackmark(struct stackmark *mark)
+{
+       struct stack_block *sp;
+
+       if (!mark->stackp)
+               return;
 
-/*** Command hashing code ***/
+       INT_OFF;
+       markp = mark->marknext;
+       while (stackp != mark->stackp) {
+               sp = stackp;
+               stackp = sp->prev;
+               free(sp);
+       }
+       stacknxt = mark->stacknxt;
+       stacknleft = mark->stacknleft;
+       sstrend = mark->stacknxt + mark->stacknleft;
+       INT_ON;
+}
 
+/*
+ * When the parser reads in a string, it wants to stick the string on the
+ * stack and only adjust the stack pointer when it knows how big the
+ * string is.  Stackblock (defined in stack.h) returns a pointer to a block
+ * of space on top of the stack and stackblocklen returns the length of
+ * this block.  Growstackblock will grow this space by at least one byte,
+ * possibly moving it (like realloc).  Grabstackblock actually allocates the
+ * part of the block that has been used.
+ */
 static void
-printentry(struct tblentry *cmdp)
+growstackblock(void)
 {
-       int idx;
-       const char *path;
-       char *name;
+       size_t newlen;
 
-       idx = cmdp->param.index;
-       path = pathval();
-       do {
-               name = padvance(&path, cmdp->cmdname);
-               stunalloc(name);
-       } while (--idx >= 0);
-       out1fmt("%s%s\n", name, (cmdp->rehash ? "*" : nullstr));
-}
+       newlen = stacknleft * 2;
+       if (newlen < stacknleft)
+               ash_msg_and_raise_error(bb_msg_memory_exhausted);
+       if (newlen < 128)
+               newlen += 128;
 
+       if (stacknxt == stackp->space && stackp != &stackbase) {
+               struct stack_block *oldstackp;
+               struct stackmark *xmark;
+               struct stack_block *sp;
+               struct stack_block *prevstackp;
+               size_t grosslen;
 
-static int
-hashcmd(int argc, char **argv)
-{
-       struct tblentry **pp;
-       struct tblentry *cmdp;
-       int c;
-       struct cmdentry entry;
-       char *name;
+               INT_OFF;
+               oldstackp = stackp;
+               sp = stackp;
+               prevstackp = sp->prev;
+               grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
+               sp = ckrealloc(sp, grosslen);
+               sp->prev = prevstackp;
+               stackp = sp;
+               stacknxt = sp->space;
+               stacknleft = newlen;
+               sstrend = sp->space + newlen;
 
-       while ((c = nextopt("r")) != '\0') {
-               clearcmdentry(0);
-               return 0;
-       }
-       if (*argptr == NULL) {
-               for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
-                       for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
-                               if (cmdp->cmdtype == CMDNORMAL)
-                                       printentry(cmdp);
-                       }
+               /*
+                * Stack marks pointing to the start of the old block
+                * must be relocated to point to the new block
+                */
+               xmark = markp;
+               while (xmark != NULL && xmark->stackp == oldstackp) {
+                       xmark->stackp = stackp;
+                       xmark->stacknxt = stacknxt;
+                       xmark->stacknleft = stacknleft;
+                       xmark = xmark->marknext;
                }
-               return 0;
-       }
-       c = 0;
-       while ((name = *argptr) != NULL) {
-               if ((cmdp = cmdlookup(name, 0)) != NULL
-                && (cmdp->cmdtype == CMDNORMAL
-                    || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
-                       delete_cmd_entry();
-               find_command(name, &entry, DO_ERR, pathval());
-               if (entry.cmdtype == CMDUNKNOWN)
-                       c = 1;
-               argptr++;
+               INT_ON;
+       } else {
+               char *oldspace = stacknxt;
+               int oldlen = stacknleft;
+               char *p = stalloc(newlen);
+
+               /* free the space we just allocated */
+               stacknxt = memcpy(p, oldspace, oldlen);
+               stacknleft += newlen;
        }
-       return c;
 }
 
+static void
+grabstackblock(size_t len)
+{
+       len = SHELL_ALIGN(len);
+       stacknxt += len;
+       stacknleft -= len;
+}
 
 /*
- * Resolve a command name.  If you change this routine, you may have to
- * change the shellexec routine as well.
+ * The following routines are somewhat easier to use than the above.
+ * The user declares a variable of type STACKSTR, which may be declared
+ * to be a register.  The macro STARTSTACKSTR initializes things.  Then
+ * the user uses the macro STPUTC to add characters to the string.  In
+ * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
+ * grown as necessary.  When the user is done, she can just leave the
+ * string there and refer to it using stackblock().  Or she can allocate
+ * the space for it using grabstackstr().  If it is necessary to allow
+ * someone else to use the stack temporarily and then continue to grow
+ * the string, the user should use grabstack to allocate the space, and
+ * then call ungrabstr(p) to return to the previous mode of operation.
+ *
+ * USTPUTC is like STPUTC except that it doesn't check for overflow.
+ * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
+ * is space for at least one character.
  */
-
-static void
-find_command(char *name, struct cmdentry *entry, int act, const char *path)
+static void *
+growstackstr(void)
 {
-       struct tblentry *cmdp;
-       int idx;
-       int prev;
-       char *fullname;
-       struct stat statb;
-       int e;
-       int updatetbl;
-       struct builtincmd *bcmd;
-
-       /* If name contains a slash, don't use PATH or hash table */
-       if (strchr(name, '/') != NULL) {
-               entry->u.index = -1;
-               if (act & DO_ABS) {
-                       while (stat(name, &statb) < 0) {
-#ifdef SYSV
-                               if (errno == EINTR)
-                                       continue;
-#endif
-                               entry->cmdtype = CMDUNKNOWN;
-                               return;
-                       }
-               }
-               entry->cmdtype = CMDNORMAL;
-               return;
+       size_t len = stackblocksize();
+       if (herefd >= 0 && len >= 1024) {
+               full_write(herefd, stackblock(), len);
+               return stackblock();
        }
+       growstackblock();
+       return stackblock() + len;
+}
 
-#ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
-       if (find_applet_by_name(name)) {
-               entry->cmdtype = CMDNORMAL;
-               entry->u.index = -1;
-               return;
-       }
-#endif
+/*
+ * Called from CHECKSTRSPACE.
+ */
+static char *
+makestrspace(size_t newlen, char *p)
+{
+       size_t len = p - stacknxt;
+       size_t size = stackblocksize();
 
-       if (is_safe_applet(name)) {
-               entry->cmdtype = CMDNORMAL;
-               entry->u.index = -1;
-               return;
-       }
+       for (;;) {
+               size_t nleft;
 
-       updatetbl = (path == pathval());
-       if (!updatetbl) {
-               act |= DO_ALTPATH;
-               if (strstr(path, "%builtin") != NULL)
-                       act |= DO_ALTBLTIN;
+               size = stackblocksize();
+               nleft = size - len;
+               if (nleft >= newlen)
+                       break;
+               growstackblock();
        }
+       return stackblock() + len;
+}
 
-       /* If name is in the table, check answer will be ok */
-       if ((cmdp = cmdlookup(name, 0)) != NULL) {
-               int bit;
+static char *
+stack_nputstr(const char *s, size_t n, char *p)
+{
+       p = makestrspace(n, p);
+       p = memcpy(p, s, n) + n;
+       return p;
+}
 
-               switch (cmdp->cmdtype) {
-               default:
-#if DEBUG
-                       abort();
-#endif
-               case CMDNORMAL:
-                       bit = DO_ALTPATH;
-                       break;
-               case CMDFUNCTION:
-                       bit = DO_NOFUNC;
-                       break;
-               case CMDBUILTIN:
-                       bit = DO_ALTBLTIN;
-                       break;
-               }
-               if (act & bit) {
-                       updatetbl = 0;
-                       cmdp = NULL;
-               } else if (cmdp->rehash == 0)
-                       /* if not invalidated by cd, we're done */
-                       goto success;
-       }
+static char *
+stack_putstr(const char *s, char *p)
+{
+       return stack_nputstr(s, strlen(s), p);
+}
 
-       /* If %builtin not in path, check for builtin next */
-       bcmd = find_builtin(name);
-       if (bcmd && (IS_BUILTIN_REGULAR(bcmd) || (
-               act & DO_ALTPATH ? !(act & DO_ALTBLTIN) : builtinloc <= 0
-       )))
-               goto builtin_success;
+static char *
+_STPUTC(int c, char *p)
+{
+       if (p == sstrend)
+               p = growstackstr();
+       *p++ = c;
+       return p;
+}
 
-       /* We have to search path. */
-       prev = -1;              /* where to start */
-       if (cmdp && cmdp->rehash) {     /* doing a rehash */
-               if (cmdp->cmdtype == CMDBUILTIN)
-                       prev = builtinloc;
-               else
-                       prev = cmdp->param.index;
-       }
+#define STARTSTACKSTR(p)        ((p) = stackblock())
+#define STPUTC(c, p)            ((p) = _STPUTC((c), (p)))
+#define CHECKSTRSPACE(n, p) \
+       do { \
+               char *q = (p); \
+               size_t l = (n); \
+               size_t m = sstrend - q; \
+               if (l > m) \
+                       (p) = makestrspace(l, q); \
+       } while (0)
+#define USTPUTC(c, p)           (*p++ = (c))
+#define STACKSTRNUL(p) \
+       do { \
+               if ((p) == sstrend) \
+                       p = growstackstr(); \
+               *p = '\0'; \
+       } while (0)
+#define STUNPUTC(p)             (--p)
+#define STTOPC(p)               (p[-1])
+#define STADJUST(amount, p)     (p += (amount))
 
-       e = ENOENT;
-       idx = -1;
-loop:
-       while ((fullname = padvance(&path, name)) != NULL) {
-               stunalloc(fullname);
-               idx++;
-               if (pathopt) {
-                       if (prefix(pathopt, "builtin")) {
-                               if (bcmd)
-                                       goto builtin_success;
-                               continue;
-                       } else if (!(act & DO_NOFUNC) &&
-                                  prefix(pathopt, "func")) {
-                               /* handled below */
-                       } else {
-                               /* ignore unimplemented options */
-                               continue;
-                       }
-               }
-               /* if rehash, don't redo absolute path names */
-               if (fullname[0] == '/' && idx <= prev) {
-                       if (idx < prev)
-                               continue;
-                       TRACE(("searchexec \"%s\": no change\n", name));
-                       goto success;
-               }
-               while (stat(fullname, &statb) < 0) {
-#ifdef SYSV
-                       if (errno == EINTR)
-                               continue;
-#endif
-                       if (errno != ENOENT && errno != ENOTDIR)
-                               e = errno;
-                       goto loop;
-               }
-               e = EACCES;     /* if we fail, this will be the error */
-               if (!S_ISREG(statb.st_mode))
-                       continue;
-               if (pathopt) {          /* this is a %func directory */
-                       stalloc(strlen(fullname) + 1);
-                       readcmdfile(fullname);
-                       if ((cmdp = cmdlookup(name, 0)) == NULL ||
-                           cmdp->cmdtype != CMDFUNCTION)
-                               sh_error("%s not defined in %s", name, fullname);
-                       stunalloc(fullname);
-                       goto success;
-               }
-               TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
-               if (!updatetbl) {
-                       entry->cmdtype = CMDNORMAL;
-                       entry->u.index = idx;
-                       return;
-               }
-               INTOFF;
-               cmdp = cmdlookup(name, 1);
-               cmdp->cmdtype = CMDNORMAL;
-               cmdp->param.index = idx;
-               INTON;
-               goto success;
-       }
+#define grabstackstr(p)         stalloc((char *)(p) - (char *)stackblock())
+#define ungrabstackstr(s, p)    stunalloc((s))
+#define stackstrend()           ((void *)sstrend)
 
-       /* We failed.  If there was an entry for this command, delete it */
-       if (cmdp && updatetbl)
-               delete_cmd_entry();
-       if (act & DO_ERR)
-               sh_warnx("%s: %s", name, errmsg(e, E_EXEC));
-       entry->cmdtype = CMDUNKNOWN;
-       return;
 
-builtin_success:
-       if (!updatetbl) {
-               entry->cmdtype = CMDBUILTIN;
-               entry->u.cmd = bcmd;
-               return;
+/* ============ String helpers */
+
+/*
+ * prefix -- see if pfx is a prefix of string.
+ */
+static char *
+prefix(const char *string, const char *pfx)
+{
+       while (*pfx) {
+               if (*pfx++ != *string++)
+                       return 0;
        }
-       INTOFF;
-       cmdp = cmdlookup(name, 1);
-       cmdp->cmdtype = CMDBUILTIN;
-       cmdp->param.cmd = bcmd;
-       INTON;
-success:
-       cmdp->rehash = 0;
-       entry->cmdtype = cmdp->cmdtype;
-       entry->u = cmdp->param;
+       return (char *) string;
 }
 
-
 /*
- * Wrapper around strcmp for qsort/bsearch/...
+ * Check for a valid number.  This should be elsewhere.
  */
-static int pstrcmp(const void *a, const void *b)
+static int
+is_number(const char *p)
 {
-       return strcmp((const char *) a, (*(const char *const *) b) + 1);
+       do {
+               if (!isdigit(*p))
+                       return 0;
+       } while (*++p != '\0');
+       return 1;
 }
 
 /*
- * Search the table of builtin commands.
+ * Convert a string of digits to an integer, printing an error message on
+ * failure.
  */
-
-static struct builtincmd *
-find_builtin(const char *name)
+static int
+number(const char *s)
 {
-       struct builtincmd *bp;
-
-       bp = bsearch(
-               name, builtincmd, NUMBUILTINS, sizeof(struct builtincmd),
-               pstrcmp
-       );
-       return bp;
+       if (!is_number(s))
+               ash_msg_and_raise_error(illnum, s);
+       return atoi(s);
 }
 
-
-
 /*
- * Called when a cd is done.  Marks all commands so the next time they
- * are executed they will be rehashed.
+ * Produce a possibly single quoted string suitable as input to the shell.
+ * The return string is allocated on the stack.
  */
-
-static void
-hashcd(void)
+static char *
+single_quote(const char *s)
 {
-       struct tblentry **pp;
-       struct tblentry *cmdp;
+       char *p;
 
-       for (pp = cmdtable ; pp < &cmdtable[CMDTABLESIZE] ; pp++) {
-               for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
-                       if (cmdp->cmdtype == CMDNORMAL || (
-                               cmdp->cmdtype == CMDBUILTIN &&
-                               !(IS_BUILTIN_REGULAR(cmdp->param.cmd)) &&
-                               builtinloc > 0
-                       ))
-                               cmdp->rehash = 1;
-               }
-       }
-}
+       STARTSTACKSTR(p);
 
+       do {
+               char *q;
+               size_t len;
 
+               len = strchrnul(s, '\'') - s;
 
-/*
- * Fix command hash table when PATH changed.
- * Called before PATH is changed.  The argument is the new value of PATH;
- * pathval() still returns the old value at this point.
- * Called with interrupts off.
- */
+               q = p = makestrspace(len + 3, p);
 
-static void
-changepath(const char *newval)
-{
-       const char *old, *new;
-       int idx;
-       int firstchange;
-       int idx_bltin;
+               *q++ = '\'';
+               q = memcpy(q, s, len) + len;
+               *q++ = '\'';
+               s += len;
 
-       old = pathval();
-       new = newval;
-       firstchange = 9999;     /* assume no change */
-       idx = 0;
-       idx_bltin = -1;
-       for (;;) {
-               if (*old != *new) {
-                       firstchange = idx;
-                       if ((*old == '\0' && *new == ':')
-                        || (*old == ':' && *new == '\0'))
-                               firstchange++;
-                       old = new;      /* ignore subsequent differences */
-               }
-               if (*new == '\0')
+               STADJUST(q - p, p);
+
+               len = strspn(s, "'");
+               if (!len)
                        break;
-               if (*new == '%' && idx_bltin < 0 && prefix(new + 1, "builtin"))
-                       idx_bltin = idx;
-               if (*new == ':') {
-                       idx++;
-               }
-               new++, old++;
-       }
-       if (builtinloc < 0 && idx_bltin >= 0)
-               builtinloc = idx_bltin;             /* zap builtins */
-       if (builtinloc >= 0 && idx_bltin < 0)
-               firstchange = 0;
-       clearcmdentry(firstchange);
-       builtinloc = idx_bltin;
-}
 
+               q = p = makestrspace(len + 3, p);
 
-/*
- * Clear out command entries.  The argument specifies the first entry in
- * PATH which has changed.
- */
+               *q++ = '"';
+               q = memcpy(q, s, len) + len;
+               *q++ = '"';
+               s += len;
 
-static void
-clearcmdentry(int firstchange)
-{
-       struct tblentry **tblp;
-       struct tblentry **pp;
-       struct tblentry *cmdp;
+               STADJUST(q - p, p);
+       } while (*s);
 
-       INTOFF;
-       for (tblp = cmdtable ; tblp < &cmdtable[CMDTABLESIZE] ; tblp++) {
-               pp = tblp;
-               while ((cmdp = *pp) != NULL) {
-                       if ((cmdp->cmdtype == CMDNORMAL &&
-                            cmdp->param.index >= firstchange)
-                        || (cmdp->cmdtype == CMDBUILTIN &&
-                            builtinloc >= firstchange)) {
-                               *pp = cmdp->next;
-                               ckfree(cmdp);
-                       } else {
-                               pp = &cmdp->next;
-                       }
-               }
-       }
-       INTON;
+       USTPUTC(0, p);
+
+       return stackblock();
 }
 
 
+/* ============ nextopt */
+
+static char **argptr;                  /* argument list for builtin commands */
+static char *optionarg;                /* set by nextopt (like getopt) */
+static char *optptr;                   /* used by nextopt */
 
 /*
- * Locate a command in the command hash table.  If "add" is nonzero,
- * add the command to the table if it is not already present.  The
- * variable "lastcmdentry" is set to point to the address of the link
- * pointing to the entry, so that delete_cmd_entry can delete the
- * entry.
+ * XXX - should get rid of.  have all builtins use getopt(3).  the
+ * library getopt must have the BSD extension static variable "optreset"
+ * otherwise it can't be used within the shell safely.
  *
- * Interrupts must be off if called with add != 0.
+ * Standard option processing (a la getopt) for builtin routines.  The
+ * only argument that is passed to nextopt is the option string; the
+ * other arguments are unnecessary.  It return the character, or '\0' on
+ * end of input.
  */
-
-static struct tblentry **lastcmdentry;
-
-
-static struct tblentry *
-cmdlookup(const char *name, int add)
+static int
+nextopt(const char *optstring)
 {
-       unsigned int hashval;
-       const char *p;
-       struct tblentry *cmdp;
-       struct tblentry **pp;
+       char *p;
+       const char *q;
+       char c;
 
-       p = name;
-       hashval = (unsigned char)*p << 4;
-       while (*p)
-               hashval += (unsigned char)*p++;
-       hashval &= 0x7FFF;
-       pp = &cmdtable[hashval % CMDTABLESIZE];
-       for (cmdp = *pp ; cmdp ; cmdp = cmdp->next) {
-               if (equal(cmdp->cmdname, name))
-                       break;
-               pp = &cmdp->next;
+       p = optptr;
+       if (p == NULL || *p == '\0') {
+               p = *argptr;
+               if (p == NULL || *p != '-' || *++p == '\0')
+                       return '\0';
+               argptr++;
+               if (LONE_DASH(p))        /* check for "--" */
+                       return '\0';
        }
-       if (add && cmdp == NULL) {
-               cmdp = *pp = ckmalloc(sizeof (struct tblentry) - ARB
-                                       + strlen(name) + 1);
-               cmdp->next = NULL;
-               cmdp->cmdtype = CMDUNKNOWN;
-               strcpy(cmdp->cmdname, name);
+       c = *p++;
+       for (q = optstring; *q != c; ) {
+               if (*q == '\0')
+                       ash_msg_and_raise_error("illegal option -%c", c);
+               if (*++q == ':')
+                       q++;
        }
-       lastcmdentry = pp;
-       return cmdp;
+       if (*++q == ':') {
+               if (*p == '\0' && (p = *argptr++) == NULL)
+                       ash_msg_and_raise_error("no arg for -%c option", c);
+               optionarg = p;
+               p = NULL;
+       }
+       optptr = p;
+       return c;
 }
 
-/*
- * Delete the command entry returned on the last lookup.
- */
 
-static void
-delete_cmd_entry(void)
-{
-       struct tblentry *cmdp;
+/* ============ Math support definitions */
 
-       INTOFF;
-       cmdp = *lastcmdentry;
-       *lastcmdentry = cmdp->next;
-       if (cmdp->cmdtype == CMDFUNCTION)
-               freefunc(cmdp->param.func);
-       ckfree(cmdp);
-       INTON;
-}
+#if ENABLE_ASH_MATH_SUPPORT_64
+typedef int64_t arith_t;
+#define arith_t_type long long
+#else
+typedef long arith_t;
+#define arith_t_type long
+#endif
+
+#if ENABLE_ASH_MATH_SUPPORT
+static arith_t dash_arith(const char *);
+static arith_t arith(const char *expr, int *perrcode);
+#endif
+
+#if ENABLE_ASH_RANDOM_SUPPORT
+static unsigned long rseed;
+#ifndef DYNAMIC_VAR
+#define DYNAMIC_VAR
+#endif
+#endif
+
+
+/* ============ Shell variables */
+
+/* flags */
+#define VEXPORT         0x01    /* variable is exported */
+#define VREADONLY       0x02    /* variable cannot be modified */
+#define VSTRFIXED       0x04    /* variable struct is statically allocated */
+#define VTEXTFIXED      0x08    /* text is statically allocated */
+#define VSTACK          0x10    /* text is allocated on the stack */
+#define VUNSET          0x20    /* the variable is not set */
+#define VNOFUNC         0x40    /* don't call the callback function */
+#define VNOSET          0x80    /* do not set variable - just readonly test */
+#define VNOSAVE         0x100   /* when text is on the heap before setvareq */
+#ifdef DYNAMIC_VAR
+# define VDYNAMIC       0x200   /* dynamic variable */
+#else
+# define VDYNAMIC       0
+#endif
+
+#ifdef IFS_BROKEN
+static const char defifsvar[] ALIGN1 = "IFS= \t\n";
+#define defifs (defifsvar + 4)
+#else
+static const char defifs[] ALIGN1 = " \t\n";
+#endif
+
+struct shparam {
+       int nparam;             /* # of positional parameters (without $0) */
+       unsigned char malloc;   /* if parameter list dynamically allocated */
+       char **p;               /* parameter list */
+#if ENABLE_ASH_GETOPTS
+       int optind;             /* next parameter to be processed by getopts */
+       int optoff;             /* used by getopts */
+#endif
+};
 
+static struct shparam shellparam;      /* $@ current positional parameters */
 
 /*
- * Add a new command entry, replacing any existing command entry for
- * the same name - except special builtins.
+ * Free the list of positional parameters.
  */
-
-static void addcmdentry(char *name, struct cmdentry *entry)
+static void
+freeparam(volatile struct shparam *param)
 {
-       struct tblentry *cmdp;
+       char **ap;
 
-       cmdp = cmdlookup(name, 1);
-       if (cmdp->cmdtype == CMDFUNCTION) {
-               freefunc(cmdp->param.func);
+       if (param->malloc) {
+               for (ap = param->p; *ap; ap++)
+                       free(*ap);
+               free(param->p);
        }
-       cmdp->cmdtype = entry->cmdtype;
-       cmdp->param = entry->u;
-       cmdp->rehash = 0;
 }
 
-/*
- * Make a copy of a parse tree.
- */
-
-static struct funcnode * copyfunc(union node *n)
+#if ENABLE_ASH_GETOPTS
+static void
+getoptsreset(const char *value)
 {
-       struct funcnode *f;
-       size_t blocksize;
-
-       funcblocksize = offsetof(struct funcnode, n);
-       funcstringsize = 0;
-       calcsize(n);
-       blocksize = funcblocksize;
-       f = ckmalloc(blocksize + funcstringsize);
-       funcblock = (char *) f + offsetof(struct funcnode, n);
-       funcstring = (char *) f + blocksize;
-       copynode(n);
-       f->count = 0;
-       return f;
+       shellparam.optind = number(value);
+       shellparam.optoff = -1;
 }
+#endif
 
-/*
- * Define a shell function.
- */
+struct var {
+       struct var *next;               /* next entry in hash list */
+       int flags;                      /* flags are defined above */
+       const char *text;               /* name=value */
+       void (*func)(const char *);     /* function to be called when  */
+                                       /* the variable gets set/unset */
+};
+
+struct localvar {
+       struct localvar *next;          /* next local variable in list */
+       struct var *vp;                 /* the variable that was made local */
+       int flags;                      /* saved flags */
+       const char *text;               /* saved text */
+};
 
+/* Forward decls for varinit[] */
+#if ENABLE_LOCALE_SUPPORT
 static void
-defun(char *name, union node *func)
+change_lc_all(const char *value)
 {
-       struct cmdentry entry;
-
-       INTOFF;
-       entry.cmdtype = CMDFUNCTION;
-       entry.u.func = copyfunc(func);
-       addcmdentry(name, &entry);
-       INTON;
+       if (value && *value != '\0')
+               setlocale(LC_ALL, value);
+}
+static void
+change_lc_ctype(const char *value)
+{
+       if (value && *value != '\0')
+               setlocale(LC_CTYPE, value);
 }
+#endif
+#if ENABLE_ASH_MAIL
+static void chkmail(void);
+static void changemail(const char *);
+#endif
+static void changepath(const char *);
+#if ENABLE_ASH_RANDOM_SUPPORT
+static void change_random(const char *);
+#endif
+
+static struct var varinit[] = {
+#ifdef IFS_BROKEN
+       { NULL, VSTRFIXED|VTEXTFIXED,           defifsvar,      NULL },
+#else
+       { NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "IFS\0",        NULL },
+#endif
+#if ENABLE_ASH_MAIL
+       { NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "MAIL\0",       changemail },
+       { NULL, VSTRFIXED|VTEXTFIXED|VUNSET,    "MAILPATH\0",   changemail },
+#endif
+       { NULL, VSTRFIXED|VTEXTFIXED,           bb_PATH_root_path, changepath },
+       { NULL, VSTRFIXED|VTEXTFIXED,           "PS1=$ ",       NULL },
+       { NULL, VSTRFIXED|VTEXTFIXED,           "PS2=> ",       NULL },
+       { NULL, VSTRFIXED|VTEXTFIXED,           "PS4=+ ",       NULL },
+#if ENABLE_ASH_GETOPTS
+       { NULL, VSTRFIXED|VTEXTFIXED,           "OPTIND=1",     getoptsreset },
+#endif
+#if ENABLE_ASH_RANDOM_SUPPORT
+       { NULL, VSTRFIXED|VTEXTFIXED|VUNSET|VDYNAMIC, "RANDOM\0", change_random },
+#endif
+#if ENABLE_LOCALE_SUPPORT
+       { NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_ALL\0",    change_lc_all },
+       { NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "LC_CTYPE\0",  change_lc_ctype },
+#endif
+#if ENABLE_FEATURE_EDITING_SAVEHISTORY
+       { NULL, VSTRFIXED | VTEXTFIXED | VUNSET, "HISTFILE\0",  NULL },
+#endif
+};
 
+#define vifs varinit[0]
+#if ENABLE_ASH_MAIL
+#define vmail (&vifs)[1]
+#define vmpath (&vmail)[1]
+#else
+#define vmpath vifs
+#endif
+#define vpath (&vmpath)[1]
+#define vps1 (&vpath)[1]
+#define vps2 (&vps1)[1]
+#define vps4 (&vps2)[1]
+#define voptind (&vps4)[1]
+#if ENABLE_ASH_GETOPTS
+#define vrandom (&voptind)[1]
+#else
+#define vrandom (&vps4)[1]
+#endif
 
 /*
- * Delete a function if it exists.
+ * The following macros access the values of the above variables.
+ * They have to skip over the name.  They return the null string
+ * for unset variables.
  */
+#define ifsval()        (vifs.text + 4)
+#define ifsset()        ((vifs.flags & VUNSET) == 0)
+#define mailval()       (vmail.text + 5)
+#define mpathval()      (vmpath.text + 9)
+#define pathval()       (vpath.text + 5)
+#define ps1val()        (vps1.text + 4)
+#define ps2val()        (vps2.text + 4)
+#define ps4val()        (vps4.text + 4)
+#define optindval()     (voptind.text + 7)
 
-static void
-unsetfunc(const char *name)
-{
-       struct tblentry *cmdp;
-
-       if ((cmdp = cmdlookup(name, 0)) != NULL &&
-           cmdp->cmdtype == CMDFUNCTION)
-               delete_cmd_entry();
-}
+#define mpathset()      ((vmpath.flags & VUNSET) == 0)
 
 /*
- * Locate and print what a word is...
+ * The parsefile structure pointed to by the global variable parsefile
+ * contains information about the current file being read.
  */
+struct redirtab {
+       struct redirtab *next;
+       int renamed[10];
+       int nullredirs;
+};
 
+static struct redirtab *redirlist;
+static int nullredirs;
+static int preverrout_fd;   /* save fd2 before print debug if xflag is set. */
 
-#ifdef CONFIG_ASH_CMDCMD
-static int
-describe_command(char *command, int describe_command_verbose)
-#else
-#define describe_command_verbose 1
-static int
-describe_command(char *command)
-#endif
-{
-       struct cmdentry entry;
-       struct tblentry *cmdp;
-#ifdef CONFIG_ASH_ALIAS
-       const struct alias *ap;
-#endif
-       const char *path = pathval();
-
-       if (describe_command_verbose) {
-               out1str(command);
-       }
-
-       /* First look at the keywords */
-       if (findkwd(command)) {
-               out1str(describe_command_verbose ? " is a shell keyword" : command);
-               goto out;
-       }
-
-#ifdef CONFIG_ASH_ALIAS
-       /* Then look at the aliases */
-       if ((ap = lookupalias(command, 0)) != NULL) {
-               if (describe_command_verbose) {
-                       out1fmt(" is an alias for %s", ap->val);
-               } else {
-                       out1str("alias ");
-                       printalias(ap);
-                       return 0;
-               }
-               goto out;
-       }
-#endif
-       /* Then check if it is a tracked alias */
-       if ((cmdp = cmdlookup(command, 0)) != NULL) {
-               entry.cmdtype = cmdp->cmdtype;
-               entry.u = cmdp->param;
-       } else {
-               /* Finally use brute force */
-               find_command(command, &entry, DO_ABS, path);
-       }
+#define VTABSIZE 39
 
-       switch (entry.cmdtype) {
-       case CMDNORMAL: {
-               int j = entry.u.index;
-               char *p;
-               if (j == -1) {
-                       p = command;
-               } else {
-                       do {
-                               p = padvance(&path, command);
-                               stunalloc(p);
-                       } while (--j >= 0);
-               }
-               if (describe_command_verbose) {
-                       out1fmt(" is%s %s",
-                               (cmdp ? " a tracked alias for" : nullstr), p
-                       );
-               } else {
-                       out1str(p);
-               }
-               break;
-       }
+static struct var *vartab[VTABSIZE];
 
-       case CMDFUNCTION:
-               if (describe_command_verbose) {
-                       out1str(" is a shell function");
-               } else {
-                       out1str(command);
-               }
-               break;
+#define is_name(c)      ((c) == '_' || isalpha((unsigned char)(c)))
+#define is_in_name(c)   ((c) == '_' || isalnum((unsigned char)(c)))
 
-       case CMDBUILTIN:
-               if (describe_command_verbose) {
-                       out1fmt(" is a %sshell builtin",
-                               IS_BUILTIN_SPECIAL(entry.u.cmd) ?
-                                       "special " : nullstr
-                       );
-               } else {
-                       out1str(command);
-               }
-               break;
+/*
+ * Return of a legal variable name (a letter or underscore followed by zero or
+ * more letters, underscores, and digits).
+ */
+static char *
+endofname(const char *name)
+{
+       char *p;
 
-       default:
-               if (describe_command_verbose) {
-                       out1str(": not found\n");
-               }
-               return 127;
+       p = (char *) name;
+       if (!is_name(*p))
+               return p;
+       while (*++p) {
+               if (!is_in_name(*p))
+                       break;
        }
-
-out:
-       outstr("\n", stdout);
-       return 0;
+       return p;
 }
 
+/*
+ * Compares two strings up to the first = or '\0'.  The first
+ * string must be terminated by '='; the second may be terminated by
+ * either '=' or '\0'.
+ */
 static int
-typecmd(int argc, char **argv)
+varcmp(const char *p, const char *q)
 {
-       int i;
-       int err = 0;
+       int c, d;
 
-       for (i = 1; i < argc; i++) {
-#ifdef CONFIG_ASH_CMDCMD
-               err |= describe_command(argv[i], 1);
-#else
-               err |= describe_command(argv[i]);
-#endif
+       while ((c = *p) == (d = *q)) {
+               if (!c || c == '=')
+                       goto out;
+               p++;
+               q++;
        }
-       return err;
+       if (c == '=')
+               c = '\0';
+       if (d == '=')
+               d = '\0';
+ out:
+       return c - d;
 }
 
-#ifdef CONFIG_ASH_CMDCMD
 static int
-commandcmd(int argc, char **argv)
+varequal(const char *a, const char *b)
 {
-       int c;
-       enum {
-               VERIFY_BRIEF = 1,
-               VERIFY_VERBOSE = 2,
-       } verify = 0;
-
-       while ((c = nextopt("pvV")) != '\0')
-               if (c == 'V')
-                       verify |= VERIFY_VERBOSE;
-               else if (c == 'v')
-                       verify |= VERIFY_BRIEF;
-#if DEBUG
-               else if (c != 'p')
-                       abort();
-#endif
-       if (verify)
-               return describe_command(*argptr, verify - VERIFY_BRIEF);
-
-       return 0;
+       return !varcmp(a, b);
 }
-#endif
-
-/*      expand.c     */
-
-/*
- * Routines to expand arguments to commands.  We have to deal with
- * backquotes, shell variables, and file metacharacters.
- */
-
-/*
- * _rmescape() flags
- */
-#define RMESCAPE_ALLOC  0x1     /* Allocate a new string */
-#define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
-#define RMESCAPE_QUOTED 0x4     /* Remove CTLESC unless in quotes */
-#define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
-#define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */
 
 /*
- * Structure specifying which parts of the string should be searched
- * for IFS characters.
+ * Find the appropriate entry in the hash table from the name.
  */
+static struct var **
+hashvar(const char *p)
+{
+       unsigned hashval;
 
-struct ifsregion {
-       struct ifsregion *next; /* next region in list */
-       int begoff;             /* offset of start of region */
-       int endoff;             /* offset of end of region */
-       int nulonly;            /* search for nul bytes only */
-};
-
-/* output of current string */
-static char *expdest;
-/* list of back quote expressions */
-static struct nodelist *argbackq;
-/* first struct in list of ifs regions */
-static struct ifsregion ifsfirst;
-/* last struct in list */
-static struct ifsregion *ifslastp;
-/* holds expanded arg list */
-static struct arglist exparg;
-
-static void argstr(char *, int);
-static char *exptilde(char *, char *, int);
-static void expbackq(union node *, int, int);
-static const char *subevalvar(char *, char *, int, int, int, int, int);
-static char *evalvar(char *, int);
-static void strtodest(const char *, int, int);
-static void memtodest(const char *p, size_t len, int syntax, int quotes);
-static ssize_t varvalue(char *, int, int);
-static void recordregion(int, int, int);
-static void removerecordregions(int);
-static void ifsbreakup(char *, struct arglist *);
-static void ifsfree(void);
-static void expandmeta(struct strlist *, int);
-static int patmatch(char *, const char *);
-
-static int cvtnum(arith_t);
-static size_t esclen(const char *, const char *);
-static char *scanleft(char *, char *, char *, char *, int, int);
-static char *scanright(char *, char *, char *, char *, int, int);
-static void varunset(const char *, const char *, const char *, int)
-       ATTRIBUTE_NORETURN;
+       hashval = ((unsigned char) *p) << 4;
+       while (*p && *p != '=')
+               hashval += (unsigned char) *p++;
+       return &vartab[hashval % VTABSIZE];
+}
 
+static int
+vpcmp(const void *a, const void *b)
+{
+       return varcmp(*(const char **)a, *(const char **)b);
+}
 
-#define pmatch(a, b) !fnmatch((a), (b), 0)
 /*
- * Prepare a pattern for a expmeta (internal glob(3)) call.
- *
- * Returns an stalloced string.
+ * This routine initializes the builtin variables.
  */
+static void
+initvar(void)
+{
+       struct var *vp;
+       struct var *end;
+       struct var **vpp;
 
-static char * preglob(const char *pattern, int quoted, int flag) {
-       flag |= RMESCAPE_GLOB;
-       if (quoted) {
-               flag |= RMESCAPE_QUOTED;
-       }
-       return _rmescapes((char *)pattern, flag);
+       /*
+        * PS1 depends on uid
+        */
+#if ENABLE_FEATURE_EDITING && ENABLE_FEATURE_EDITING_FANCY_PROMPT
+       vps1.text = "PS1=\\w \\$ ";
+#else
+       if (!geteuid())
+               vps1.text = "PS1=# ";
+#endif
+       vp = varinit;
+       end = vp + ARRAY_SIZE(varinit);
+       do {
+               vpp = hashvar(vp->text);
+               vp->next = *vpp;
+               *vpp = vp;
+       } while (++vp < end);
 }
 
-
-static size_t
-esclen(const char *start, const char *p) {
-       size_t esc = 0;
-
-       while (p > start && *--p == CTLESC) {
-               esc++;
+static struct var **
+findvar(struct var **vpp, const char *name)
+{
+       for (; *vpp; vpp = &(*vpp)->next) {
+               if (varequal((*vpp)->text, name)) {
+                       break;
+               }
        }
-       return esc;
+       return vpp;
 }
 
-
 /*
- * Expand shell variables and backquotes inside a here document.
+ * Find the value of a variable.  Returns NULL if not set.
  */
-
-static void expandhere(union node *arg, int fd)
+static char *
+lookupvar(const char *name)
 {
-       herefd = fd;
-       expandarg(arg, (struct arglist *)NULL, 0);
-       full_write(fd, stackblock(), expdest - (char *)stackblock());
-}
+       struct var *v;
 
+       v = *findvar(hashvar(name), name);
+       if (v) {
+#ifdef DYNAMIC_VAR
+       /*
+        * Dynamic variables are implemented roughly the same way they are
+        * in bash. Namely, they're "special" so long as they aren't unset.
+        * As soon as they're unset, they're no longer dynamic, and dynamic
+        * lookup will no longer happen at that point. -- PFM.
+        */
+               if ((v->flags & VDYNAMIC))
+                       (*v->func)(NULL);
+#endif
+               if (!(v->flags & VUNSET))
+                       return strchrnul(v->text, '=') + 1;
+       }
+       return NULL;
+}
 
 /*
- * Perform variable substitution and command substitution on an argument,
- * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
- * perform splitting and file name expansion.  When arglist is NULL, perform
- * here document expansion.
+ * Search the environment of a builtin command.
  */
-
-void
-expandarg(union node *arg, struct arglist *arglist, int flag)
+static char *
+bltinlookup(const char *name)
 {
        struct strlist *sp;
-       char *p;
 
-       argbackq = arg->narg.backquote;
-       STARTSTACKSTR(expdest);
-       ifsfirst.next = NULL;
-       ifslastp = NULL;
-       argstr(arg->narg.text, flag);
-       p = _STPUTC('\0', expdest);
-       expdest = p - 1;
-       if (arglist == NULL) {
-               return;                 /* here document expanded */
-       }
-       p = grabstackstr(p);
-       exparg.lastp = &exparg.list;
-       /*
-        * TODO - EXP_REDIR
-        */
-       if (flag & EXP_FULL) {
-               ifsbreakup(p, &exparg);
-               *exparg.lastp = NULL;
-               exparg.lastp = &exparg.list;
-               expandmeta(exparg.list, flag);
-       } else {
-               if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
-                       rmescapes(p);
-               sp = (struct strlist *)stalloc(sizeof (struct strlist));
-               sp->text = p;
-               *exparg.lastp = sp;
-               exparg.lastp = &sp->next;
-       }
-       if (ifsfirst.next)
-               ifsfree();
-       *exparg.lastp = NULL;
-       if (exparg.list) {
-               *arglist->lastp = exparg.list;
-               arglist->lastp = exparg.lastp;
+       for (sp = cmdenviron; sp; sp = sp->next) {
+               if (varequal(sp->text, name))
+                       return strchrnul(sp->text, '=') + 1;
        }
+       return lookupvar(name);
 }
 
-
 /*
- * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
- * characters to allow for further processing.  Otherwise treat
- * $@ like $* since no splitting will be performed.
+ * Same as setvar except that the variable and value are passed in
+ * the first argument as name=value.  Since the first argument will
+ * be actually stored in the table, it should not be a string that
+ * will go away.
+ * Called with interrupts off.
  */
-
 static void
-argstr(char *p, int flag)
+setvareq(char *s, int flags)
 {
-       static const char spclchars[] = {
-               '=',
-               ':',
-               CTLQUOTEMARK,
-               CTLENDVAR,
-               CTLESC,
-               CTLVAR,
-               CTLBACKQ,
-               CTLBACKQ | CTLQUOTE,
-#ifdef CONFIG_ASH_MATH_SUPPORT
-               CTLENDARI,
-#endif
-               0
-       };
-       const char *reject = spclchars;
-       int c;
-       int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
-       int breakall = flag & EXP_WORD;
-       int inquotes;
-       size_t length;
-       int startloc;
+       struct var *vp, **vpp;
 
-       if (!(flag & EXP_VARTILDE)) {
-               reject += 2;
-       } else if (flag & EXP_VARTILDE2) {
-               reject++;
-       }
-       inquotes = 0;
-       length = 0;
-       if (flag & EXP_TILDE) {
-               char *q;
+       vpp = hashvar(s);
+       flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
+       vp = *findvar(vpp, s);
+       if (vp) {
+               if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) {
+                       const char *n;
 
-               flag &= ~EXP_TILDE;
-tilde:
-               q = p;
-               if (*q == CTLESC && (flag & EXP_QWORD))
-                       q++;
-               if (*q == '~')
-                       p = exptilde(p, q, flag);
-       }
-start:
-       startloc = expdest - (char *)stackblock();
-       for (;;) {
-               length += strcspn(p + length, reject);
-               c = p[length];
-               if (c && (!(c & 0x80)
-#ifdef CONFIG_ASH_MATH_SUPPORT
-                                       || c == CTLENDARI
-#endif
-                  )) {
-                       /* c == '=' || c == ':' || c == CTLENDARI */
-                       length++;
-               }
-               if (length > 0) {
-                       int newloc;
-                       expdest = stnputs(p, length, expdest);
-                       newloc = expdest - (char *)stackblock();
-                       if (breakall && !inquotes && newloc > startloc) {
-                               recordregion(startloc, newloc, 0);
-                       }
-                       startloc = newloc;
+                       if (flags & VNOSAVE)
+                               free(s);
+                       n = vp->text;
+                       ash_msg_and_raise_error("%.*s: is read only", strchrnul(n, '=') - n, n);
                }
-               p += length + 1;
-               length = 0;
 
-               switch (c) {
-               case '\0':
-                       goto breakloop;
-               case '=':
-                       if (flag & EXP_VARTILDE2) {
-                               p--;
-                               continue;
-                       }
-                       flag |= EXP_VARTILDE2;
-                       reject++;
-                       /* fall through */
-               case ':':
-                       /*
-                        * sort of a hack - expand tildes in variable
-                        * assignments (after the first '=' and after ':'s).
-                        */
-                       if (*--p == '~') {
-                               goto tilde;
-                       }
-                       continue;
-               }
+               if (flags & VNOSET)
+                       return;
 
-               switch (c) {
-               case CTLENDVAR: /* ??? */
-                       goto breakloop;
-               case CTLQUOTEMARK:
-                       /* "$@" syntax adherence hack */
-                       if (
-                               !inquotes &&
-                               !memcmp(p, dolatstr, DOLATSTRLEN) &&
-                               (p[4] == CTLQUOTEMARK || (
-                                       p[4] == CTLENDVAR &&
-                                       p[5] == CTLQUOTEMARK
-                               ))
-                       ) {
-                               p = evalvar(p + 1, flag) + 1;
-                               goto start;
-                       }
-                       inquotes = !inquotes;
-addquote:
-                       if (quotes) {
-                               p--;
-                               length++;
-                               startloc++;
-                       }
-                       break;
-               case CTLESC:
-                       startloc++;
-                       length++;
-                       goto addquote;
-               case CTLVAR:
-                       p = evalvar(p, flag);
-                       goto start;
-               case CTLBACKQ:
-                       c = 0;
-               case CTLBACKQ|CTLQUOTE:
-                       expbackq(argbackq->n, c, quotes);
-                       argbackq = argbackq->next;
-                       goto start;
-#ifdef CONFIG_ASH_MATH_SUPPORT
-               case CTLENDARI:
-                       p--;
-                       expari(quotes);
-                       goto start;
-#endif
-               }
+               if (vp->func && (flags & VNOFUNC) == 0)
+                       (*vp->func)(strchrnul(s, '=') + 1);
+
+               if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
+                       free((char*)vp->text);
+
+               flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
+       } else {
+               if (flags & VNOSET)
+                       return;
+               /* not found */
+               vp = ckmalloc(sizeof(*vp));
+               vp->next = *vpp;
+               vp->func = NULL;
+               *vpp = vp;
+       }
+       if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
+               s = ckstrdup(s);
+       vp->text = s;
+       vp->flags = flags;
+}
+
+/*
+ * Set the value of a variable.  The flags argument is ored with the
+ * flags of the variable.  If val is NULL, the variable is unset.
+ */
+static void
+setvar(const char *name, const char *val, int flags)
+{
+       char *p, *q;
+       size_t namelen;
+       char *nameeq;
+       size_t vallen;
+
+       q = endofname(name);
+       p = strchrnul(q, '=');
+       namelen = p - name;
+       if (!namelen || p != q)
+               ash_msg_and_raise_error("%.*s: bad variable name", namelen, name);
+       vallen = 0;
+       if (val == NULL) {
+               flags |= VUNSET;
+       } else {
+               vallen = strlen(val);
        }
-breakloop:
-       ;
+       INT_OFF;
+       nameeq = ckmalloc(namelen + vallen + 2);
+       p = memcpy(nameeq, name, namelen) + namelen;
+       if (val) {
+               *p++ = '=';
+               p = memcpy(p, val, vallen) + vallen;
+       }
+       *p = '\0';
+       setvareq(nameeq, flags | VNOSAVE);
+       INT_ON;
 }
 
-static char *
-exptilde(char *startp, char *p, int flag)
+#if ENABLE_ASH_GETOPTS
+/*
+ * Safe version of setvar, returns 1 on success 0 on failure.
+ */
+static int
+setvarsafe(const char *name, const char *val, int flags)
 {
-       char c;
-       char *name;
-       struct passwd *pw;
-       const char *home;
-       int quotes = flag & (EXP_FULL | EXP_CASE);
-       int startloc;
+       int err;
+       volatile int saveint;
+       struct jmploc *volatile savehandler = exception_handler;
+       struct jmploc jmploc;
 
-       name = p + 1;
+       SAVE_INT(saveint);
+       if (setjmp(jmploc.loc))
+               err = 1;
+       else {
+               exception_handler = &jmploc;
+               setvar(name, val, flags);
+               err = 0;
+       }
+       exception_handler = savehandler;
+       RESTORE_INT(saveint);
+       return err;
+}
+#endif
 
-       while ((c = *++p) != '\0') {
-               switch(c) {
-               case CTLESC:
-                       return (startp);
-               case CTLQUOTEMARK:
-                       return (startp);
-               case ':':
-                       if (flag & EXP_VARTILDE)
-                               goto done;
-                       break;
-               case '/':
-               case CTLENDVAR:
-                       goto done;
+/*
+ * Unset the specified variable.
+ */
+static int
+unsetvar(const char *s)
+{
+       struct var **vpp;
+       struct var *vp;
+       int retval;
+
+       vpp = findvar(hashvar(s), s);
+       vp = *vpp;
+       retval = 2;
+       if (vp) {
+               int flags = vp->flags;
+
+               retval = 1;
+               if (flags & VREADONLY)
+                       goto out;
+#ifdef DYNAMIC_VAR
+               vp->flags &= ~VDYNAMIC;
+#endif
+               if (flags & VUNSET)
+                       goto ok;
+               if ((flags & VSTRFIXED) == 0) {
+                       INT_OFF;
+                       if ((flags & (VTEXTFIXED|VSTACK)) == 0)
+                               free((char*)vp->text);
+                       *vpp = vp->next;
+                       free(vp);
+                       INT_ON;
+               } else {
+                       setvar(s, 0, 0);
+                       vp->flags &= ~VEXPORT;
                }
+ ok:
+               retval = 0;
        }
-done:
-       *p = '\0';
-       if (*name == '\0') {
-               home = lookupvar(homestr);
-       } else {
-               if ((pw = getpwnam(name)) == NULL)
-                       goto lose;
-               home = pw->pw_dir;
-       }
-       if (!home || !*home)
-               goto lose;
-       *p = c;
-       startloc = expdest - (char *)stackblock();
-       strtodest(home, SQSYNTAX, quotes);
-       recordregion(startloc, expdest - (char *)stackblock(), 0);
-       return p;
-lose:
-       *p = c;
-       return startp;
+ out:
+       return retval;
 }
 
-
+/*
+ * Process a linked list of variable assignments.
+ */
 static void
-removerecordregions(int endoff)
+listsetvar(struct strlist *list_set_var, int flags)
 {
-       if (ifslastp == NULL)
-               return;
+       struct strlist *lp = list_set_var;
 
-       if (ifsfirst.endoff > endoff) {
-               while (ifsfirst.next != NULL) {
-                       struct ifsregion *ifsp;
-                       INTOFF;
-                       ifsp = ifsfirst.next->next;
-                       ckfree(ifsfirst.next);
-                       ifsfirst.next = ifsp;
-                       INTON;
-               }
-               if (ifsfirst.begoff > endoff)
-                       ifslastp = NULL;
-               else {
-                       ifslastp = &ifsfirst;
-                       ifsfirst.endoff = endoff;
-               }
+       if (!lp)
                return;
-       }
+       INT_OFF;
+       do {
+               setvareq(lp->text, flags);
+               lp = lp->next;
+       } while (lp);
+       INT_ON;
+}
 
-       ifslastp = &ifsfirst;
-       while (ifslastp->next && ifslastp->next->begoff < endoff)
-               ifslastp=ifslastp->next;
-       while (ifslastp->next != NULL) {
-               struct ifsregion *ifsp;
-               INTOFF;
-               ifsp = ifslastp->next->next;
-               ckfree(ifslastp->next);
-               ifslastp->next = ifsp;
-               INTON;
-       }
-       if (ifslastp->endoff > endoff)
-               ifslastp->endoff = endoff;
+/*
+ * Generate a list of variables satisfying the given conditions.
+ */
+static char **
+listvars(int on, int off, char ***end)
+{
+       struct var **vpp;
+       struct var *vp;
+       char **ep;
+       int mask;
+
+       STARTSTACKSTR(ep);
+       vpp = vartab;
+       mask = on | off;
+       do {
+               for (vp = *vpp; vp; vp = vp->next) {
+                       if ((vp->flags & mask) == on) {
+                               if (ep == stackstrend())
+                                       ep = growstackstr();
+                               *ep++ = (char *) vp->text;
+                       }
+               }
+       } while (++vpp < vartab + VTABSIZE);
+       if (ep == stackstrend())
+               ep = growstackstr();
+       if (end)
+               *end = ep;
+       *ep++ = NULL;
+       return grabstackstr(ep);
 }
 
 
-#ifdef CONFIG_ASH_MATH_SUPPORT
-/*
- * Expand arithmetic expression.  Backup to start of expression,
- * evaluate, place result in (backed up) result, adjust string position.
+/* ============ Path search helper
+ *
+ * The variable path (passed by reference) should be set to the start
+ * of the path before the first call; padvance will update
+ * this value as it proceeds.  Successive calls to padvance will return
+ * the possible path expansions in sequence.  If an option (indicated by
+ * a percent sign) appears in the path entry then the global variable
+ * pathopt will be set to point to it; otherwise pathopt will be set to
+ * NULL.
  */
-void
-expari(int quotes)
+static const char *pathopt;     /* set by padvance */
+
+static char *
+padvance(const char **path, const char *name)
 {
-       char *p, *start;
-       int begoff;
-       int flag;
-       int len;
+       const char *p;
+       char *q;
+       const char *start;
+       size_t len;
 
-       /*      ifsfree(); */
+       if (*path == NULL)
+               return NULL;
+       start = *path;
+       for (p = start; *p && *p != ':' && *p != '%'; p++);
+       len = p - start + strlen(name) + 2;     /* "2" is for '/' and '\0' */
+       while (stackblocksize() < len)
+               growstackblock();
+       q = stackblock();
+       if (p != start) {
+               memcpy(q, start, p - start);
+               q += p - start;
+               *q++ = '/';
+       }
+       strcpy(q, name);
+       pathopt = NULL;
+       if (*p == '%') {
+               pathopt = ++p;
+               while (*p && *p != ':') p++;
+       }
+       if (*p == ':')
+               *path = p + 1;
+       else
+               *path = NULL;
+       return stalloc(len);
+}
 
-       /*
-        * This routine is slightly over-complicated for
-        * efficiency.  Next we scan backwards looking for the
-        * start of arithmetic.
-        */
-       start = stackblock();
-       p = expdest - 1;
-       *p = '\0';
-       p--;
-       do {
-               int esc;
 
-               while (*p != CTLARI) {
-                       p--;
-#if DEBUG
-                       if (p < start) {
-                               sh_error("missing CTLARI (shouldn't happen)");
-                       }
+/* ============ Prompt */
+
+static smallint doprompt;                   /* if set, prompt the user */
+static smallint needprompt;                 /* true if interactive and at start of line */
+
+#if ENABLE_FEATURE_EDITING
+static line_input_t *line_input_state;
+static const char *cmdedit_prompt;
+static void
+putprompt(const char *s)
+{
+       if (ENABLE_ASH_EXPAND_PRMT) {
+               free((char*)cmdedit_prompt);
+               cmdedit_prompt = ckstrdup(s);
+               return;
+       }
+       cmdedit_prompt = s;
+}
+#else
+static void
+putprompt(const char *s)
+{
+       out2str(s);
+}
+#endif
+
+#if ENABLE_ASH_EXPAND_PRMT
+/* expandstr() needs parsing machinery, so it is far away ahead... */
+static const char *expandstr(const char *ps);
+#else
+#define expandstr(s) s
+#endif
+
+static void
+setprompt(int whichprompt)
+{
+       const char *prompt;
+#if ENABLE_ASH_EXPAND_PRMT
+       struct stackmark smark;
 #endif
-               }
 
-               esc = esclen(start, p);
-               if (!(esc % 2)) {
-                       break;
-               }
+       needprompt = 0;
 
-               p -= esc + 1;
-       } while (1);
+       switch (whichprompt) {
+       case 1:
+               prompt = ps1val();
+               break;
+       case 2:
+               prompt = ps2val();
+               break;
+       default:                        /* 0 */
+               prompt = nullstr;
+       }
+#if ENABLE_ASH_EXPAND_PRMT
+       setstackmark(&smark);
+       stalloc(stackblocksize());
+#endif
+       putprompt(expandstr(prompt));
+#if ENABLE_ASH_EXPAND_PRMT
+       popstackmark(&smark);
+#endif
+}
 
-       begoff = p - start;
 
-       removerecordregions(begoff);
+/* ============ The cd and pwd commands */
 
-       flag = p[1];
+#define CD_PHYSICAL 1
+#define CD_PRINT 2
 
-       expdest = p;
+static int docd(const char *, int);
 
-       if (quotes)
-               rmescapes(p + 2);
+static char *curdir = nullstr;          /* current working directory */
+static char *physdir = nullstr;         /* physical working directory */
 
-       len = cvtnum(dash_arith(p + 2));
+static int
+cdopt(void)
+{
+       int flags = 0;
+       int i, j;
 
-       if (flag != '"')
-               recordregion(begoff, begoff + len, 0);
+       j = 'L';
+       while ((i = nextopt("LP"))) {
+               if (i != j) {
+                       flags ^= CD_PHYSICAL;
+                       j = i;
+               }
+       }
+
+       return flags;
 }
-#endif
 
 /*
- * Expand stuff in backwards quotes.
+ * Update curdir (the name of the current directory) in response to a
+ * cd command.
+ */
+static const char *
+updatepwd(const char *dir)
+{
+       char *new;
+       char *p;
+       char *cdcomppath;
+       const char *lim;
+
+       cdcomppath = ststrdup(dir);
+       STARTSTACKSTR(new);
+       if (*dir != '/') {
+               if (curdir == nullstr)
+                       return 0;
+               new = stack_putstr(curdir, new);
+       }
+       new = makestrspace(strlen(dir) + 2, new);
+       lim = stackblock() + 1;
+       if (*dir != '/') {
+               if (new[-1] != '/')
+                       USTPUTC('/', new);
+               if (new > lim && *lim == '/')
+                       lim++;
+       } else {
+               USTPUTC('/', new);
+               cdcomppath++;
+               if (dir[1] == '/' && dir[2] != '/') {
+                       USTPUTC('/', new);
+                       cdcomppath++;
+                       lim++;
+               }
+       }
+       p = strtok(cdcomppath, "/");
+       while (p) {
+               switch (*p) {
+               case '.':
+                       if (p[1] == '.' && p[2] == '\0') {
+                               while (new > lim) {
+                                       STUNPUTC(new);
+                                       if (new[-1] == '/')
+                                               break;
+                               }
+                               break;
+                       }
+                       if (p[1] == '\0')
+                               break;
+                       /* fall through */
+               default:
+                       new = stack_putstr(p, new);
+                       USTPUTC('/', new);
+               }
+               p = strtok(0, "/");
+       }
+       if (new > lim)
+               STUNPUTC(new);
+       *new = 0;
+       return stackblock();
+}
+
+/*
+ * Find out what the current directory is. If we already know the current
+ * directory, this routine returns immediately.
  */
+static char *
+getpwd(void)
+{
+       char *dir = getcwd(0, 0);
+       return dir ? dir : nullstr;
+}
 
 static void
-expbackq(union node *cmd, int quoted, int quotes)
+setpwd(const char *val, int setold)
 {
-       struct backcmd in;
-       int i;
-       char buf[128];
-       char *p;
-       char *dest;
-       int startloc;
-       int syntax = quoted? DQSYNTAX : BASESYNTAX;
-       struct stackmark smark;
+       char *oldcur, *dir;
 
-       INTOFF;
-       setstackmark(&smark);
-       dest = expdest;
-       startloc = dest - (char *)stackblock();
-       grabstackstr(dest);
-       evalbackcmd(cmd, (struct backcmd *) &in);
-       popstackmark(&smark);
+       oldcur = dir = curdir;
 
-       p = in.buf;
-       i = in.nleft;
-       if (i == 0)
-               goto read;
-       for (;;) {
-               memtodest(p, i, syntax, quotes);
-read:
-               if (in.fd < 0)
-                       break;
-               i = safe_read(in.fd, buf, sizeof buf);
-               TRACE(("expbackq: read returns %d\n", i));
-               if (i <= 0)
-                       break;
-               p = buf;
+       if (setold) {
+               setvar("OLDPWD", oldcur, VEXPORT);
        }
-
-       if (in.buf)
-               ckfree(in.buf);
-       if (in.fd >= 0) {
-               close(in.fd);
-               back_exitstatus = waitforjob(in.jp);
+       INT_OFF;
+       if (physdir != nullstr) {
+               if (physdir != oldcur)
+                       free(physdir);
+               physdir = nullstr;
+       }
+       if (oldcur == val || !val) {
+               char *s = getpwd();
+               physdir = s;
+               if (!val)
+                       dir = s;
+       } else
+               dir = ckstrdup(val);
+       if (oldcur != dir && oldcur != nullstr) {
+               free(oldcur);
        }
-       INTON;
+       curdir = dir;
+       INT_ON;
+       setvar("PWD", dir, VEXPORT);
+}
 
-       /* Eat all trailing newlines */
-       dest = expdest;
-       for (; dest > (char *)stackblock() && dest[-1] == '\n';)
-               STUNPUTC(dest);
-       expdest = dest;
+static void hashcd(void);
 
-       if (quoted == 0)
-               recordregion(startloc, dest - (char *)stackblock(), 0);
-       TRACE(("evalbackq: size=%d: \"%.*s\"\n",
-               (dest - (char *)stackblock()) - startloc,
-               (dest - (char *)stackblock()) - startloc,
-               stackblock() + startloc));
-}
+/*
+ * Actually do the chdir.  We also call hashcd to let the routines in exec.c
+ * know that the current directory has changed.
+ */
+static int
+docd(const char *dest, int flags)
+{
+       const char *dir = 0;
+       int err;
 
+       TRACE(("docd(\"%s\", %d) called\n", dest, flags));
 
-static char *
-scanleft(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
-       int zero)
+       INT_OFF;
+       if (!(flags & CD_PHYSICAL)) {
+               dir = updatepwd(dest);
+               if (dir)
+                       dest = dir;
+       }
+       err = chdir(dest);
+       if (err)
+               goto out;
+       setpwd(dir, 1);
+       hashcd();
+ out:
+       INT_ON;
+       return err;
+}
+
+static int
+cdcmd(int argc, char **argv)
 {
-       char *loc;
-       char *loc2;
+       const char *dest;
+       const char *path;
+       const char *p;
        char c;
+       struct stat statb;
+       int flags;
 
-       loc = startp;
-       loc2 = rmesc;
+       flags = cdopt();
+       dest = *argptr;
+       if (!dest)
+               dest = bltinlookup(homestr);
+       else if (LONE_DASH(dest)) {
+               dest = bltinlookup("OLDPWD");
+               flags |= CD_PRINT;
+       }
+       if (!dest)
+               dest = nullstr;
+       if (*dest == '/')
+               goto step7;
+       if (*dest == '.') {
+               c = dest[1];
+ dotdot:
+               switch (c) {
+               case '\0':
+               case '/':
+                       goto step6;
+               case '.':
+                       c = dest[2];
+                       if (c != '.')
+                               goto dotdot;
+               }
+       }
+       if (!*dest)
+               dest = ".";
+       path = bltinlookup("CDPATH");
+       if (!path) {
+ step6:
+ step7:
+               p = dest;
+               goto docd;
+       }
        do {
-               int match;
-               const char *s = loc2;
-               c = *loc2;
-               if (zero) {
-                       *loc2 = '\0';
-                       s = rmesc;
+               c = *path;
+               p = padvance(&path, dest);
+               if (stat(p, &statb) >= 0 && S_ISDIR(statb.st_mode)) {
+                       if (c && c != ':')
+                               flags |= CD_PRINT;
+ docd:
+                       if (!docd(p, flags))
+                               goto out;
+                       break;
                }
-               match = pmatch(str, s);
-               *loc2 = c;
-               if (match)
-                       return loc;
-               if (quotes && *loc == CTLESC)
-                       loc++;
-               loc++;
-               loc2++;
-       } while (c);
+       } while (path);
+       ash_msg_and_raise_error("can't cd to %s", dest);
+       /* NOTREACHED */
+ out:
+       if (flags & CD_PRINT)
+               out1fmt(snlfmt, curdir);
        return 0;
 }
 
-
-static char *
-scanright(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
-       int zero)
+static int
+pwdcmd(int argc, char **argv)
 {
-       int esc = 0;
-       char *loc;
-       char *loc2;
+       int flags;
+       const char *dir = curdir;
 
-       for (loc = str - 1, loc2 = rmescend; loc >= startp; loc2--) {
-               int match;
-               char c = *loc2;
-               const char *s = loc2;
-               if (zero) {
-                       *loc2 = '\0';
-                       s = rmesc;
-               }
-               match = pmatch(str, s);
-               *loc2 = c;
-               if (match)
-                       return loc;
-               loc--;
-               if (quotes) {
-                       if (--esc < 0) {
-                               esc = esclen(startp, loc);
-                       }
-                       if (esc % 2) {
-                               esc--;
-                               loc--;
-                       }
-               }
+       flags = cdopt();
+       if (flags) {
+               if (physdir == nullstr)
+                       setpwd(dir, 0);
+               dir = physdir;
        }
+       out1fmt(snlfmt, dir);
        return 0;
 }
 
-static const char *
-subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
-{
-       char *startp;
-       char *loc;
-       int saveherefd = herefd;
-       struct nodelist *saveargbackq = argbackq;
-       int amount;
-       char *rmesc, *rmescend;
-       int zero;
-       char *(*scan)(char *, char *, char *, char *, int , int);
 
-       herefd = -1;
-       argstr(p, subtype != VSASSIGN && subtype != VSQUESTION ? EXP_CASE : 0);
-       STPUTC('\0', expdest);
-       herefd = saveherefd;
-       argbackq = saveargbackq;
-       startp = stackblock() + startloc;
+/* ============ ... */
 
-       switch (subtype) {
-       case VSASSIGN:
-               setvar(str, startp, 0);
-               amount = startp - expdest;
-               STADJUST(amount, expdest);
-               return startp;
+#define IBUFSIZ COMMON_BUFSIZE
+#define basebuf bb_common_bufsiz1       /* buffer for top level input file */
 
-       case VSQUESTION:
-               varunset(p, str, startp, varflags);
-               /* NOTREACHED */
-       }
+/* Syntax classes */
+#define CWORD 0                 /* character is nothing special */
+#define CNL 1                   /* newline character */
+#define CBACK 2                 /* a backslash character */
+#define CSQUOTE 3               /* single quote */
+#define CDQUOTE 4               /* double quote */
+#define CENDQUOTE 5             /* a terminating quote */
+#define CBQUOTE 6               /* backwards single quote */
+#define CVAR 7                  /* a dollar sign */
+#define CENDVAR 8               /* a '}' character */
+#define CLP 9                   /* a left paren in arithmetic */
+#define CRP 10                  /* a right paren in arithmetic */
+#define CENDFILE 11             /* end of file */
+#define CCTL 12                 /* like CWORD, except it must be escaped */
+#define CSPCL 13                /* these terminate a word */
+#define CIGN 14                 /* character should be ignored */
 
-       subtype -= VSTRIMRIGHT;
-#if DEBUG
-       if (subtype < 0 || subtype > 3)
-               abort();
+#if ENABLE_ASH_ALIAS
+#define SYNBASE 130
+#define PEOF -130
+#define PEOA -129
+#define PEOA_OR_PEOF PEOA
+#else
+#define SYNBASE 129
+#define PEOF -129
+#define PEOA_OR_PEOF PEOF
 #endif
 
-       rmesc = startp;
-       rmescend = stackblock() + strloc;
-       if (quotes) {
-               rmesc = _rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
-               if (rmesc != startp) {
-                       rmescend = expdest;
-                       startp = stackblock() + startloc;
-               }
-       }
-       rmescend--;
-       str = stackblock() + strloc;
-       preglob(str, varflags & VSQUOTE, 0);
+/* number syntax index */
+#define BASESYNTAX 0    /* not in quotes */
+#define DQSYNTAX   1    /* in double quotes */
+#define SQSYNTAX   2    /* in single quotes */
+#define ARISYNTAX  3    /* in arithmetic */
+#define PSSYNTAX   4    /* prompt */
 
-       /* zero = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX */
-       zero = subtype >> 1;
-       /* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */
-       scan = (subtype & 1) ^ zero ? scanleft : scanright;
+#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
+#define USE_SIT_FUNCTION
+#endif
 
-       loc = scan(startp, rmesc, rmescend, str, quotes, zero);
-       if (loc) {
-               if (zero) {
-                       memmove(startp, loc, str - loc);
-                       loc = startp + (str - loc) - 1;
-               }
-               *loc = '\0';
-               amount = loc - expdest;
-               STADJUST(amount, expdest);
-       }
-       return loc;
-}
+#if ENABLE_ASH_MATH_SUPPORT
+static const char S_I_T[][4] = {
+#if ENABLE_ASH_ALIAS
+       { CSPCL, CIGN, CIGN, CIGN },            /* 0, PEOA */
+#endif
+       { CSPCL, CWORD, CWORD, CWORD },         /* 1, ' ' */
+       { CNL, CNL, CNL, CNL },                 /* 2, \n */
+       { CWORD, CCTL, CCTL, CWORD },           /* 3, !*-/:=?[]~ */
+       { CDQUOTE, CENDQUOTE, CWORD, CWORD },   /* 4, '"' */
+       { CVAR, CVAR, CWORD, CVAR },            /* 5, $ */
+       { CSQUOTE, CWORD, CENDQUOTE, CWORD },   /* 6, "'" */
+       { CSPCL, CWORD, CWORD, CLP },           /* 7, ( */
+       { CSPCL, CWORD, CWORD, CRP },           /* 8, ) */
+       { CBACK, CBACK, CCTL, CBACK },          /* 9, \ */
+       { CBQUOTE, CBQUOTE, CWORD, CBQUOTE },   /* 10, ` */
+       { CENDVAR, CENDVAR, CWORD, CENDVAR },   /* 11, } */
+#ifndef USE_SIT_FUNCTION
+       { CENDFILE, CENDFILE, CENDFILE, CENDFILE }, /* 12, PEOF */
+       { CWORD, CWORD, CWORD, CWORD },         /* 13, 0-9A-Za-z */
+       { CCTL, CCTL, CCTL, CCTL }              /* 14, CTLESC ... */
+#endif
+};
+#else
+static const char S_I_T[][3] = {
+#if ENABLE_ASH_ALIAS
+       { CSPCL, CIGN, CIGN },                  /* 0, PEOA */
+#endif
+       { CSPCL, CWORD, CWORD },                /* 1, ' ' */
+       { CNL, CNL, CNL },                      /* 2, \n */
+       { CWORD, CCTL, CCTL },                  /* 3, !*-/:=?[]~ */
+       { CDQUOTE, CENDQUOTE, CWORD },          /* 4, '"' */
+       { CVAR, CVAR, CWORD },                  /* 5, $ */
+       { CSQUOTE, CWORD, CENDQUOTE },          /* 6, "'" */
+       { CSPCL, CWORD, CWORD },                /* 7, ( */
+       { CSPCL, CWORD, CWORD },                /* 8, ) */
+       { CBACK, CBACK, CCTL },                 /* 9, \ */
+       { CBQUOTE, CBQUOTE, CWORD },            /* 10, ` */
+       { CENDVAR, CENDVAR, CWORD },            /* 11, } */
+#ifndef USE_SIT_FUNCTION
+       { CENDFILE, CENDFILE, CENDFILE },       /* 12, PEOF */
+       { CWORD, CWORD, CWORD },                /* 13, 0-9A-Za-z */
+       { CCTL, CCTL, CCTL }                    /* 14, CTLESC ... */
+#endif
+};
+#endif /* ASH_MATH_SUPPORT */
 
+#ifdef USE_SIT_FUNCTION
 
-/*
- * Expand a variable, and return a pointer to the next character in the
- * input string.
- */
-static char *
-evalvar(char *p, int flag)
+static int
+SIT(int c, int syntax)
 {
-       int subtype;
-       int varflags;
-       char *var;
-       int patloc;
-       int c;
-       int startloc;
-       ssize_t varlen;
-       int easy;
-       int quotes;
-       int quoted;
-
-       quotes = flag & (EXP_FULL | EXP_CASE);
-       varflags = *p++;
-       subtype = varflags & VSTYPE;
-       quoted = varflags & VSQUOTE;
-       var = p;
-       easy = (!quoted || (*var == '@' && shellparam.nparam));
-       startloc = expdest - (char *)stackblock();
-       p = strchr(p, '=') + 1;
+       static const char spec_symbls[] ALIGN1 = "\t\n !\"$&'()*-/:;<=>?[\\]`|}~";
+#if ENABLE_ASH_ALIAS
+       static const char syntax_index_table[] ALIGN1 = {
+               1, 2, 1, 3, 4, 5, 1, 6,         /* "\t\n !\"$&'" */
+               7, 8, 3, 3, 3, 3, 1, 1,         /* "()*-/:;<" */
+               3, 1, 3, 3, 9, 3, 10, 1,        /* "=>?[\\]`|" */
+               11, 3                           /* "}~" */
+       };
+#else
+       static const char syntax_index_table[] ALIGN1 = {
+               0, 1, 0, 2, 3, 4, 0, 5,         /* "\t\n !\"$&'" */
+               6, 7, 2, 2, 2, 2, 0, 0,         /* "()*-/:;<" */
+               2, 0, 2, 2, 8, 2, 9, 0,         /* "=>?[\\]`|" */
+               10, 2                           /* "}~" */
+       };
+#endif
+       const char *s;
+       int indx;
 
-again:
-       varlen = varvalue(var, varflags, flag);
-       if (varflags & VSNUL)
-               varlen--;
+       if (c == PEOF)          /* 2^8+2 */
+               return CENDFILE;
+#if ENABLE_ASH_ALIAS
+       if (c == PEOA)          /* 2^8+1 */
+               indx = 0;
+       else
+#endif
+#define U_C(c) ((unsigned char)(c))
 
-       if (subtype == VSPLUS) {
-               varlen = -1 - varlen;
-               goto vsplus;
+       if ((unsigned char)c >= (unsigned char)(CTLESC)
+        && (unsigned char)c <= (unsigned char)(CTLQUOTEMARK)
+       ) {
+               return CCTL;
+       } else {
+               s = strchr(spec_symbls, c);
+               if (s == NULL || *s == '\0')
+                       return CWORD;
+               indx = syntax_index_table[(s - spec_symbls)];
        }
+       return S_I_T[indx][syntax];
+}
+
+#else   /* !USE_SIT_FUNCTION */
+
+#if ENABLE_ASH_ALIAS
+#define CSPCL_CIGN_CIGN_CIGN                     0
+#define CSPCL_CWORD_CWORD_CWORD                  1
+#define CNL_CNL_CNL_CNL                          2
+#define CWORD_CCTL_CCTL_CWORD                    3
+#define CDQUOTE_CENDQUOTE_CWORD_CWORD            4
+#define CVAR_CVAR_CWORD_CVAR                     5
+#define CSQUOTE_CWORD_CENDQUOTE_CWORD            6
+#define CSPCL_CWORD_CWORD_CLP                    7
+#define CSPCL_CWORD_CWORD_CRP                    8
+#define CBACK_CBACK_CCTL_CBACK                   9
+#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE           10
+#define CENDVAR_CENDVAR_CWORD_CENDVAR           11
+#define CENDFILE_CENDFILE_CENDFILE_CENDFILE     12
+#define CWORD_CWORD_CWORD_CWORD                 13
+#define CCTL_CCTL_CCTL_CCTL                     14
+#else
+#define CSPCL_CWORD_CWORD_CWORD                  0
+#define CNL_CNL_CNL_CNL                          1
+#define CWORD_CCTL_CCTL_CWORD                    2
+#define CDQUOTE_CENDQUOTE_CWORD_CWORD            3
+#define CVAR_CVAR_CWORD_CVAR                     4
+#define CSQUOTE_CWORD_CENDQUOTE_CWORD            5
+#define CSPCL_CWORD_CWORD_CLP                    6
+#define CSPCL_CWORD_CWORD_CRP                    7
+#define CBACK_CBACK_CCTL_CBACK                   8
+#define CBQUOTE_CBQUOTE_CWORD_CBQUOTE            9
+#define CENDVAR_CENDVAR_CWORD_CENDVAR           10
+#define CENDFILE_CENDFILE_CENDFILE_CENDFILE     11
+#define CWORD_CWORD_CWORD_CWORD                 12
+#define CCTL_CCTL_CCTL_CCTL                     13
+#endif
+
+static const char syntax_index_table[258] = {
+       /* BASESYNTAX_DQSYNTAX_SQSYNTAX_ARISYNTAX */
+       /*   0  PEOF */      CENDFILE_CENDFILE_CENDFILE_CENDFILE,
+#if ENABLE_ASH_ALIAS
+       /*   1  PEOA */      CSPCL_CIGN_CIGN_CIGN,
+#endif
+       /*   2  -128 0x80 */ CWORD_CWORD_CWORD_CWORD,
+       /*   3  -127 CTLESC       */ CCTL_CCTL_CCTL_CCTL,
+       /*   4  -126 CTLVAR       */ CCTL_CCTL_CCTL_CCTL,
+       /*   5  -125 CTLENDVAR    */ CCTL_CCTL_CCTL_CCTL,
+       /*   6  -124 CTLBACKQ     */ CCTL_CCTL_CCTL_CCTL,
+       /*   7  -123 CTLQUOTE     */ CCTL_CCTL_CCTL_CCTL,
+       /*   8  -122 CTLARI       */ CCTL_CCTL_CCTL_CCTL,
+       /*   9  -121 CTLENDARI    */ CCTL_CCTL_CCTL_CCTL,
+       /*  10  -120 CTLQUOTEMARK */ CCTL_CCTL_CCTL_CCTL,
+       /*  11  -119      */ CWORD_CWORD_CWORD_CWORD,
+       /*  12  -118      */ CWORD_CWORD_CWORD_CWORD,
+       /*  13  -117      */ CWORD_CWORD_CWORD_CWORD,
+       /*  14  -116      */ CWORD_CWORD_CWORD_CWORD,
+       /*  15  -115      */ CWORD_CWORD_CWORD_CWORD,
+       /*  16  -114      */ CWORD_CWORD_CWORD_CWORD,
+       /*  17  -113      */ CWORD_CWORD_CWORD_CWORD,
+       /*  18  -112      */ CWORD_CWORD_CWORD_CWORD,
+       /*  19  -111      */ CWORD_CWORD_CWORD_CWORD,
+       /*  20  -110      */ CWORD_CWORD_CWORD_CWORD,
+       /*  21  -109      */ CWORD_CWORD_CWORD_CWORD,
+       /*  22  -108      */ CWORD_CWORD_CWORD_CWORD,
+       /*  23  -107      */ CWORD_CWORD_CWORD_CWORD,
+       /*  24  -106      */ CWORD_CWORD_CWORD_CWORD,
+       /*  25  -105      */ CWORD_CWORD_CWORD_CWORD,
+       /*  26  -104      */ CWORD_CWORD_CWORD_CWORD,
+       /*  27  -103      */ CWORD_CWORD_CWORD_CWORD,
+       /*  28  -102      */ CWORD_CWORD_CWORD_CWORD,
+       /*  29  -101      */ CWORD_CWORD_CWORD_CWORD,
+       /*  30  -100      */ CWORD_CWORD_CWORD_CWORD,
+       /*  31   -99      */ CWORD_CWORD_CWORD_CWORD,
+       /*  32   -98      */ CWORD_CWORD_CWORD_CWORD,
+       /*  33   -97      */ CWORD_CWORD_CWORD_CWORD,
+       /*  34   -96      */ CWORD_CWORD_CWORD_CWORD,
+       /*  35   -95      */ CWORD_CWORD_CWORD_CWORD,
+       /*  36   -94      */ CWORD_CWORD_CWORD_CWORD,
+       /*  37   -93      */ CWORD_CWORD_CWORD_CWORD,
+       /*  38   -92      */ CWORD_CWORD_CWORD_CWORD,
+       /*  39   -91      */ CWORD_CWORD_CWORD_CWORD,
+       /*  40   -90      */ CWORD_CWORD_CWORD_CWORD,
+       /*  41   -89      */ CWORD_CWORD_CWORD_CWORD,
+       /*  42   -88      */ CWORD_CWORD_CWORD_CWORD,
+       /*  43   -87      */ CWORD_CWORD_CWORD_CWORD,
+       /*  44   -86      */ CWORD_CWORD_CWORD_CWORD,
+       /*  45   -85      */ CWORD_CWORD_CWORD_CWORD,
+       /*  46   -84      */ CWORD_CWORD_CWORD_CWORD,
+       /*  47   -83      */ CWORD_CWORD_CWORD_CWORD,
+       /*  48   -82      */ CWORD_CWORD_CWORD_CWORD,
+       /*  49   -81      */ CWORD_CWORD_CWORD_CWORD,
+       /*  50   -80      */ CWORD_CWORD_CWORD_CWORD,
+       /*  51   -79      */ CWORD_CWORD_CWORD_CWORD,
+       /*  52   -78      */ CWORD_CWORD_CWORD_CWORD,
+       /*  53   -77      */ CWORD_CWORD_CWORD_CWORD,
+       /*  54   -76      */ CWORD_CWORD_CWORD_CWORD,
+       /*  55   -75      */ CWORD_CWORD_CWORD_CWORD,
+       /*  56   -74      */ CWORD_CWORD_CWORD_CWORD,
+       /*  57   -73      */ CWORD_CWORD_CWORD_CWORD,
+       /*  58   -72      */ CWORD_CWORD_CWORD_CWORD,
+       /*  59   -71      */ CWORD_CWORD_CWORD_CWORD,
+       /*  60   -70      */ CWORD_CWORD_CWORD_CWORD,
+       /*  61   -69      */ CWORD_CWORD_CWORD_CWORD,
+       /*  62   -68      */ CWORD_CWORD_CWORD_CWORD,
+       /*  63   -67      */ CWORD_CWORD_CWORD_CWORD,
+       /*  64   -66      */ CWORD_CWORD_CWORD_CWORD,
+       /*  65   -65      */ CWORD_CWORD_CWORD_CWORD,
+       /*  66   -64      */ CWORD_CWORD_CWORD_CWORD,
+       /*  67   -63      */ CWORD_CWORD_CWORD_CWORD,
+       /*  68   -62      */ CWORD_CWORD_CWORD_CWORD,
+       /*  69   -61      */ CWORD_CWORD_CWORD_CWORD,
+       /*  70   -60      */ CWORD_CWORD_CWORD_CWORD,
+       /*  71   -59      */ CWORD_CWORD_CWORD_CWORD,
+       /*  72   -58      */ CWORD_CWORD_CWORD_CWORD,
+       /*  73   -57      */ CWORD_CWORD_CWORD_CWORD,
+       /*  74   -56      */ CWORD_CWORD_CWORD_CWORD,
+       /*  75   -55      */ CWORD_CWORD_CWORD_CWORD,
+       /*  76   -54      */ CWORD_CWORD_CWORD_CWORD,
+       /*  77   -53      */ CWORD_CWORD_CWORD_CWORD,
+       /*  78   -52      */ CWORD_CWORD_CWORD_CWORD,
+       /*  79   -51      */ CWORD_CWORD_CWORD_CWORD,
+       /*  80   -50      */ CWORD_CWORD_CWORD_CWORD,
+       /*  81   -49      */ CWORD_CWORD_CWORD_CWORD,
+       /*  82   -48      */ CWORD_CWORD_CWORD_CWORD,
+       /*  83   -47      */ CWORD_CWORD_CWORD_CWORD,
+       /*  84   -46      */ CWORD_CWORD_CWORD_CWORD,
+       /*  85   -45      */ CWORD_CWORD_CWORD_CWORD,
+       /*  86   -44      */ CWORD_CWORD_CWORD_CWORD,
+       /*  87   -43      */ CWORD_CWORD_CWORD_CWORD,
+       /*  88   -42      */ CWORD_CWORD_CWORD_CWORD,
+       /*  89   -41      */ CWORD_CWORD_CWORD_CWORD,
+       /*  90   -40      */ CWORD_CWORD_CWORD_CWORD,
+       /*  91   -39      */ CWORD_CWORD_CWORD_CWORD,
+       /*  92   -38      */ CWORD_CWORD_CWORD_CWORD,
+       /*  93   -37      */ CWORD_CWORD_CWORD_CWORD,
+       /*  94   -36      */ CWORD_CWORD_CWORD_CWORD,
+       /*  95   -35      */ CWORD_CWORD_CWORD_CWORD,
+       /*  96   -34      */ CWORD_CWORD_CWORD_CWORD,
+       /*  97   -33      */ CWORD_CWORD_CWORD_CWORD,
+       /*  98   -32      */ CWORD_CWORD_CWORD_CWORD,
+       /*  99   -31      */ CWORD_CWORD_CWORD_CWORD,
+       /* 100   -30      */ CWORD_CWORD_CWORD_CWORD,
+       /* 101   -29      */ CWORD_CWORD_CWORD_CWORD,
+       /* 102   -28      */ CWORD_CWORD_CWORD_CWORD,
+       /* 103   -27      */ CWORD_CWORD_CWORD_CWORD,
+       /* 104   -26      */ CWORD_CWORD_CWORD_CWORD,
+       /* 105   -25      */ CWORD_CWORD_CWORD_CWORD,
+       /* 106   -24      */ CWORD_CWORD_CWORD_CWORD,
+       /* 107   -23      */ CWORD_CWORD_CWORD_CWORD,
+       /* 108   -22      */ CWORD_CWORD_CWORD_CWORD,
+       /* 109   -21      */ CWORD_CWORD_CWORD_CWORD,
+       /* 110   -20      */ CWORD_CWORD_CWORD_CWORD,
+       /* 111   -19      */ CWORD_CWORD_CWORD_CWORD,
+       /* 112   -18      */ CWORD_CWORD_CWORD_CWORD,
+       /* 113   -17      */ CWORD_CWORD_CWORD_CWORD,
+       /* 114   -16      */ CWORD_CWORD_CWORD_CWORD,
+       /* 115   -15      */ CWORD_CWORD_CWORD_CWORD,
+       /* 116   -14      */ CWORD_CWORD_CWORD_CWORD,
+       /* 117   -13      */ CWORD_CWORD_CWORD_CWORD,
+       /* 118   -12      */ CWORD_CWORD_CWORD_CWORD,
+       /* 119   -11      */ CWORD_CWORD_CWORD_CWORD,
+       /* 120   -10      */ CWORD_CWORD_CWORD_CWORD,
+       /* 121    -9      */ CWORD_CWORD_CWORD_CWORD,
+       /* 122    -8      */ CWORD_CWORD_CWORD_CWORD,
+       /* 123    -7      */ CWORD_CWORD_CWORD_CWORD,
+       /* 124    -6      */ CWORD_CWORD_CWORD_CWORD,
+       /* 125    -5      */ CWORD_CWORD_CWORD_CWORD,
+       /* 126    -4      */ CWORD_CWORD_CWORD_CWORD,
+       /* 127    -3      */ CWORD_CWORD_CWORD_CWORD,
+       /* 128    -2      */ CWORD_CWORD_CWORD_CWORD,
+       /* 129    -1      */ CWORD_CWORD_CWORD_CWORD,
+       /* 130     0      */ CWORD_CWORD_CWORD_CWORD,
+       /* 131     1      */ CWORD_CWORD_CWORD_CWORD,
+       /* 132     2      */ CWORD_CWORD_CWORD_CWORD,
+       /* 133     3      */ CWORD_CWORD_CWORD_CWORD,
+       /* 134     4      */ CWORD_CWORD_CWORD_CWORD,
+       /* 135     5      */ CWORD_CWORD_CWORD_CWORD,
+       /* 136     6      */ CWORD_CWORD_CWORD_CWORD,
+       /* 137     7      */ CWORD_CWORD_CWORD_CWORD,
+       /* 138     8      */ CWORD_CWORD_CWORD_CWORD,
+       /* 139     9 "\t" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 140    10 "\n" */ CNL_CNL_CNL_CNL,
+       /* 141    11      */ CWORD_CWORD_CWORD_CWORD,
+       /* 142    12      */ CWORD_CWORD_CWORD_CWORD,
+       /* 143    13      */ CWORD_CWORD_CWORD_CWORD,
+       /* 144    14      */ CWORD_CWORD_CWORD_CWORD,
+       /* 145    15      */ CWORD_CWORD_CWORD_CWORD,
+       /* 146    16      */ CWORD_CWORD_CWORD_CWORD,
+       /* 147    17      */ CWORD_CWORD_CWORD_CWORD,
+       /* 148    18      */ CWORD_CWORD_CWORD_CWORD,
+       /* 149    19      */ CWORD_CWORD_CWORD_CWORD,
+       /* 150    20      */ CWORD_CWORD_CWORD_CWORD,
+       /* 151    21      */ CWORD_CWORD_CWORD_CWORD,
+       /* 152    22      */ CWORD_CWORD_CWORD_CWORD,
+       /* 153    23      */ CWORD_CWORD_CWORD_CWORD,
+       /* 154    24      */ CWORD_CWORD_CWORD_CWORD,
+       /* 155    25      */ CWORD_CWORD_CWORD_CWORD,
+       /* 156    26      */ CWORD_CWORD_CWORD_CWORD,
+       /* 157    27      */ CWORD_CWORD_CWORD_CWORD,
+       /* 158    28      */ CWORD_CWORD_CWORD_CWORD,
+       /* 159    29      */ CWORD_CWORD_CWORD_CWORD,
+       /* 160    30      */ CWORD_CWORD_CWORD_CWORD,
+       /* 161    31      */ CWORD_CWORD_CWORD_CWORD,
+       /* 162    32  " " */ CSPCL_CWORD_CWORD_CWORD,
+       /* 163    33  "!" */ CWORD_CCTL_CCTL_CWORD,
+       /* 164    34  """ */ CDQUOTE_CENDQUOTE_CWORD_CWORD,
+       /* 165    35  "#" */ CWORD_CWORD_CWORD_CWORD,
+       /* 166    36  "$" */ CVAR_CVAR_CWORD_CVAR,
+       /* 167    37  "%" */ CWORD_CWORD_CWORD_CWORD,
+       /* 168    38  "&" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 169    39  "'" */ CSQUOTE_CWORD_CENDQUOTE_CWORD,
+       /* 170    40  "(" */ CSPCL_CWORD_CWORD_CLP,
+       /* 171    41  ")" */ CSPCL_CWORD_CWORD_CRP,
+       /* 172    42  "*" */ CWORD_CCTL_CCTL_CWORD,
+       /* 173    43  "+" */ CWORD_CWORD_CWORD_CWORD,
+       /* 174    44  "," */ CWORD_CWORD_CWORD_CWORD,
+       /* 175    45  "-" */ CWORD_CCTL_CCTL_CWORD,
+       /* 176    46  "." */ CWORD_CWORD_CWORD_CWORD,
+       /* 177    47  "/" */ CWORD_CCTL_CCTL_CWORD,
+       /* 178    48  "0" */ CWORD_CWORD_CWORD_CWORD,
+       /* 179    49  "1" */ CWORD_CWORD_CWORD_CWORD,
+       /* 180    50  "2" */ CWORD_CWORD_CWORD_CWORD,
+       /* 181    51  "3" */ CWORD_CWORD_CWORD_CWORD,
+       /* 182    52  "4" */ CWORD_CWORD_CWORD_CWORD,
+       /* 183    53  "5" */ CWORD_CWORD_CWORD_CWORD,
+       /* 184    54  "6" */ CWORD_CWORD_CWORD_CWORD,
+       /* 185    55  "7" */ CWORD_CWORD_CWORD_CWORD,
+       /* 186    56  "8" */ CWORD_CWORD_CWORD_CWORD,
+       /* 187    57  "9" */ CWORD_CWORD_CWORD_CWORD,
+       /* 188    58  ":" */ CWORD_CCTL_CCTL_CWORD,
+       /* 189    59  ";" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 190    60  "<" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 191    61  "=" */ CWORD_CCTL_CCTL_CWORD,
+       /* 192    62  ">" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 193    63  "?" */ CWORD_CCTL_CCTL_CWORD,
+       /* 194    64  "@" */ CWORD_CWORD_CWORD_CWORD,
+       /* 195    65  "A" */ CWORD_CWORD_CWORD_CWORD,
+       /* 196    66  "B" */ CWORD_CWORD_CWORD_CWORD,
+       /* 197    67  "C" */ CWORD_CWORD_CWORD_CWORD,
+       /* 198    68  "D" */ CWORD_CWORD_CWORD_CWORD,
+       /* 199    69  "E" */ CWORD_CWORD_CWORD_CWORD,
+       /* 200    70  "F" */ CWORD_CWORD_CWORD_CWORD,
+       /* 201    71  "G" */ CWORD_CWORD_CWORD_CWORD,
+       /* 202    72  "H" */ CWORD_CWORD_CWORD_CWORD,
+       /* 203    73  "I" */ CWORD_CWORD_CWORD_CWORD,
+       /* 204    74  "J" */ CWORD_CWORD_CWORD_CWORD,
+       /* 205    75  "K" */ CWORD_CWORD_CWORD_CWORD,
+       /* 206    76  "L" */ CWORD_CWORD_CWORD_CWORD,
+       /* 207    77  "M" */ CWORD_CWORD_CWORD_CWORD,
+       /* 208    78  "N" */ CWORD_CWORD_CWORD_CWORD,
+       /* 209    79  "O" */ CWORD_CWORD_CWORD_CWORD,
+       /* 210    80  "P" */ CWORD_CWORD_CWORD_CWORD,
+       /* 211    81  "Q" */ CWORD_CWORD_CWORD_CWORD,
+       /* 212    82  "R" */ CWORD_CWORD_CWORD_CWORD,
+       /* 213    83  "S" */ CWORD_CWORD_CWORD_CWORD,
+       /* 214    84  "T" */ CWORD_CWORD_CWORD_CWORD,
+       /* 215    85  "U" */ CWORD_CWORD_CWORD_CWORD,
+       /* 216    86  "V" */ CWORD_CWORD_CWORD_CWORD,
+       /* 217    87  "W" */ CWORD_CWORD_CWORD_CWORD,
+       /* 218    88  "X" */ CWORD_CWORD_CWORD_CWORD,
+       /* 219    89  "Y" */ CWORD_CWORD_CWORD_CWORD,
+       /* 220    90  "Z" */ CWORD_CWORD_CWORD_CWORD,
+       /* 221    91  "[" */ CWORD_CCTL_CCTL_CWORD,
+       /* 222    92  "\" */ CBACK_CBACK_CCTL_CBACK,
+       /* 223    93  "]" */ CWORD_CCTL_CCTL_CWORD,
+       /* 224    94  "^" */ CWORD_CWORD_CWORD_CWORD,
+       /* 225    95  "_" */ CWORD_CWORD_CWORD_CWORD,
+       /* 226    96  "`" */ CBQUOTE_CBQUOTE_CWORD_CBQUOTE,
+       /* 227    97  "a" */ CWORD_CWORD_CWORD_CWORD,
+       /* 228    98  "b" */ CWORD_CWORD_CWORD_CWORD,
+       /* 229    99  "c" */ CWORD_CWORD_CWORD_CWORD,
+       /* 230   100  "d" */ CWORD_CWORD_CWORD_CWORD,
+       /* 231   101  "e" */ CWORD_CWORD_CWORD_CWORD,
+       /* 232   102  "f" */ CWORD_CWORD_CWORD_CWORD,
+       /* 233   103  "g" */ CWORD_CWORD_CWORD_CWORD,
+       /* 234   104  "h" */ CWORD_CWORD_CWORD_CWORD,
+       /* 235   105  "i" */ CWORD_CWORD_CWORD_CWORD,
+       /* 236   106  "j" */ CWORD_CWORD_CWORD_CWORD,
+       /* 237   107  "k" */ CWORD_CWORD_CWORD_CWORD,
+       /* 238   108  "l" */ CWORD_CWORD_CWORD_CWORD,
+       /* 239   109  "m" */ CWORD_CWORD_CWORD_CWORD,
+       /* 240   110  "n" */ CWORD_CWORD_CWORD_CWORD,
+       /* 241   111  "o" */ CWORD_CWORD_CWORD_CWORD,
+       /* 242   112  "p" */ CWORD_CWORD_CWORD_CWORD,
+       /* 243   113  "q" */ CWORD_CWORD_CWORD_CWORD,
+       /* 244   114  "r" */ CWORD_CWORD_CWORD_CWORD,
+       /* 245   115  "s" */ CWORD_CWORD_CWORD_CWORD,
+       /* 246   116  "t" */ CWORD_CWORD_CWORD_CWORD,
+       /* 247   117  "u" */ CWORD_CWORD_CWORD_CWORD,
+       /* 248   118  "v" */ CWORD_CWORD_CWORD_CWORD,
+       /* 249   119  "w" */ CWORD_CWORD_CWORD_CWORD,
+       /* 250   120  "x" */ CWORD_CWORD_CWORD_CWORD,
+       /* 251   121  "y" */ CWORD_CWORD_CWORD_CWORD,
+       /* 252   122  "z" */ CWORD_CWORD_CWORD_CWORD,
+       /* 253   123  "{" */ CWORD_CWORD_CWORD_CWORD,
+       /* 254   124  "|" */ CSPCL_CWORD_CWORD_CWORD,
+       /* 255   125  "}" */ CENDVAR_CENDVAR_CWORD_CENDVAR,
+       /* 256   126  "~" */ CWORD_CCTL_CCTL_CWORD,
+       /* 257   127      */ CWORD_CWORD_CWORD_CWORD,
+};
 
-       if (subtype == VSMINUS) {
-vsplus:
-               if (varlen < 0) {
-                       argstr(
-                               p, flag | EXP_TILDE |
-                                       (quoted ?  EXP_QWORD : EXP_WORD)
-                       );
-                       goto end;
-               }
-               if (easy)
-                       goto record;
-               goto end;
-       }
+#define SIT(c, syntax) (S_I_T[(int)syntax_index_table[((int)c)+SYNBASE]][syntax])
 
-       if (subtype == VSASSIGN || subtype == VSQUESTION) {
-               if (varlen < 0) {
-                       if (subevalvar(p, var, 0, subtype, startloc,
-                                      varflags, 0)) {
-                               varflags &= ~VSNUL;
-                               /*
-                                * Remove any recorded regions beyond
-                                * start of variable
-                                */
-                               removerecordregions(startloc);
-                               goto again;
-                       }
-                       goto end;
-               }
-               if (easy)
-                       goto record;
-               goto end;
-       }
+#endif  /* USE_SIT_FUNCTION */
 
-       if (varlen < 0 && uflag)
-               varunset(p, var, 0, 0);
 
-       if (subtype == VSLENGTH) {
-               cvtnum(varlen > 0 ? varlen : 0);
-               goto record;
-       }
+/* ============ Alias handling */
 
-       if (subtype == VSNORMAL) {
-               if (!easy)
-                       goto end;
-record:
-               recordregion(startloc, expdest - (char *)stackblock(), quoted);
-               goto end;
-       }
+#if ENABLE_ASH_ALIAS
 
-#if DEBUG
-       switch (subtype) {
-       case VSTRIMLEFT:
-       case VSTRIMLEFTMAX:
-       case VSTRIMRIGHT:
-       case VSTRIMRIGHTMAX:
-               break;
-       default:
-               abort();
-       }
-#endif
+#define ALIASINUSE 1
+#define ALIASDEAD  2
 
-       if (varlen >= 0) {
-               /*
-                * Terminate the string and start recording the pattern
-                * right after it
-                */
-               STPUTC('\0', expdest);
-               patloc = expdest - (char *)stackblock();
-               if (subevalvar(p, NULL, patloc, subtype,
-                              startloc, varflags, quotes) == 0) {
-                       int amount = expdest - (
-                               (char *)stackblock() + patloc - 1
-                       );
-                       STADJUST(-amount, expdest);
-               }
-               /* Remove any recorded regions beyond start of variable */
-               removerecordregions(startloc);
-               goto record;
-       }
+#define ATABSIZE 39
 
-end:
-       if (subtype != VSNORMAL) {      /* skip to end of alternative */
-               int nesting = 1;
-               for (;;) {
-                       if ((c = *p++) == CTLESC)
-                               p++;
-                       else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
-                               if (varlen >= 0)
-                                       argbackq = argbackq->next;
-                       } else if (c == CTLVAR) {
-                               if ((*p++ & VSTYPE) != VSNORMAL)
-                                       nesting++;
-                       } else if (c == CTLENDVAR) {
-                               if (--nesting == 0)
-                                       break;
-                       }
-               }
-       }
-       return p;
-}
+struct alias {
+       struct alias *next;
+       char *name;
+       char *val;
+       int flag;
+};
 
+static struct alias *atab[ATABSIZE];
 
-/*
- * Put a string on the stack.
- */
+static struct alias **
+__lookupalias(const char *name) {
+       unsigned int hashval;
+       struct alias **app;
+       const char *p;
+       unsigned int ch;
 
-static void
-memtodest(const char *p, size_t len, int syntax, int quotes) {
-       char *q = expdest;
+       p = name;
 
-       q = makestrspace(len * 2, q);
+       ch = (unsigned char)*p;
+       hashval = ch << 4;
+       while (ch) {
+               hashval += ch;
+               ch = (unsigned char)*++p;
+       }
+       app = &atab[hashval % ATABSIZE];
 
-       while (len--) {
-               int c = SC2INT(*p++);
-               if (!c)
-                       continue;
-               if (quotes && (SIT(c, syntax) == CCTL || SIT(c, syntax) == CBACK))
-                       USTPUTC(CTLESC, q);
-               USTPUTC(c, q);
+       for (; *app; app = &(*app)->next) {
+               if (strcmp(name, (*app)->name) == 0) {
+                       break;
+               }
        }
 
-       expdest = q;
+       return app;
 }
 
-
-static void
-strtodest(const char *p, int syntax, int quotes)
+static struct alias *
+lookupalias(const char *name, int check)
 {
-       memtodest(p, strlen(p), syntax, quotes);
-}
-
+       struct alias *ap = *__lookupalias(name);
 
-/*
- * Add the value of a specialized variable to the stack string.
- */
+       if (check && ap && (ap->flag & ALIASINUSE))
+               return NULL;
+       return ap;
+}
 
-static ssize_t
-varvalue(char *name, int varflags, int flags)
+static struct alias *
+freealias(struct alias *ap)
 {
-       int num;
-       char *p;
-       int i;
-       int sep = 0;
-       int sepq = 0;
-       ssize_t len = 0;
-       char **ap;
-       int syntax;
-       int quoted = varflags & VSQUOTE;
-       int subtype = varflags & VSTYPE;
-       int quotes = flags & (EXP_FULL | EXP_CASE);
+       struct alias *next;
 
-       if (quoted && (flags & EXP_FULL))
-               sep = 1 << CHAR_BIT;
+       if (ap->flag & ALIASINUSE) {
+               ap->flag |= ALIASDEAD;
+               return ap;
+       }
 
-       syntax = quoted ? DQSYNTAX : BASESYNTAX;
-       switch (*name) {
-       case '$':
-               num = rootpid;
-               goto numvar;
-       case '?':
-               num = exitstatus;
-               goto numvar;
-       case '#':
-               num = shellparam.nparam;
-               goto numvar;
-       case '!':
-               num = backgndpid;
-               if (num == 0)
-                       return -1;
-numvar:
-               len = cvtnum(num);
-               break;
-       case '-':
-               p = makestrspace(NOPTS, expdest);
-               for (i = NOPTS - 1; i >= 0; i--) {
-                       if (optlist[i]) {
-                               USTPUTC(optletters(i), p);
-                               len++;
-                       }
-               }
-               expdest = p;
-               break;
-       case '@':
-               if (sep)
-                       goto param;
-               /* fall through */
-       case '*':
-               sep = ifsset() ? SC2INT(ifsval()[0]) : ' ';
-               if (quotes && (SIT(sep, syntax) == CCTL || SIT(sep, syntax) == CBACK))
-                       sepq = 1;
-param:
-               if (!(ap = shellparam.p))
-                       return -1;
-               while ((p = *ap++)) {
-                       size_t partlen;
+       next = ap->next;
+       free(ap->name);
+       free(ap->val);
+       free(ap);
+       return next;
+}
 
-                       partlen = strlen(p);
-                       len += partlen;
+static void
+setalias(const char *name, const char *val)
+{
+       struct alias *ap, **app;
 
-                       if (!(subtype == VSPLUS || subtype == VSLENGTH))
-                               memtodest(p, partlen, syntax, quotes);
+       app = __lookupalias(name);
+       ap = *app;
+       INT_OFF;
+       if (ap) {
+               if (!(ap->flag & ALIASINUSE)) {
+                       free(ap->val);
+               }
+               ap->val = ckstrdup(val);
+               ap->flag &= ~ALIASDEAD;
+       } else {
+               /* not found */
+               ap = ckmalloc(sizeof(struct alias));
+               ap->name = ckstrdup(name);
+               ap->val = ckstrdup(val);
+               ap->flag = 0;
+               ap->next = 0;
+               *app = ap;
+       }
+       INT_ON;
+}
 
-                       if (*ap && sep) {
-                               char *q;
+static int
+unalias(const char *name)
+{
+       struct alias **app;
 
-                               len++;
-                               if (subtype == VSPLUS || subtype == VSLENGTH) {
-                                       continue;
-                               }
-                               q = expdest;
-                               if (sepq)
-                                       STPUTC(CTLESC, q);
-                               STPUTC(sep, q);
-                               expdest = q;
-                       }
-               }
-               return len;
-       case '0':
-       case '1':
-       case '2':
-       case '3':
-       case '4':
-       case '5':
-       case '6':
-       case '7':
-       case '8':
-       case '9':
-               num = atoi(name);
-               if (num < 0 || num > shellparam.nparam)
-                       return -1;
-               p = num ? shellparam.p[num - 1] : arg0;
-               goto value;
-       default:
-               p = lookupvar(name);
-value:
-               if (!p)
-                       return -1;
+       app = __lookupalias(name);
 
-               len = strlen(p);
-               if (!(subtype == VSPLUS || subtype == VSLENGTH))
-                       memtodest(p, len, syntax, quotes);
-               return len;
+       if (*app) {
+               INT_OFF;
+               *app = freealias(*app);
+               INT_ON;
+               return 0;
        }
 
-       if (subtype == VSPLUS || subtype == VSLENGTH)
-               STADJUST(-len, expdest);
-       return len;
+       return 1;
 }
 
+static void
+rmaliases(void)
+{
+       struct alias *ap, **app;
+       int i;
 
-/*
- * Record the fact that we have to scan this region of the
- * string for IFS characters.
- */
+       INT_OFF;
+       for (i = 0; i < ATABSIZE; i++) {
+               app = &atab[i];
+               for (ap = *app; ap; ap = *app) {
+                       *app = freealias(*app);
+                       if (ap == *app) {
+                               app = &ap->next;
+                       }
+               }
+       }
+       INT_ON;
+}
 
 static void
-recordregion(int start, int end, int nulonly)
+printalias(const struct alias *ap)
 {
-       struct ifsregion *ifsp;
-
-       if (ifslastp == NULL) {
-               ifsp = &ifsfirst;
-       } else {
-               INTOFF;
-               ifsp = (struct ifsregion *)ckmalloc(sizeof (struct ifsregion));
-               ifsp->next = NULL;
-               ifslastp->next = ifsp;
-               INTON;
-       }
-       ifslastp = ifsp;
-       ifslastp->begoff = start;
-       ifslastp->endoff = end;
-       ifslastp->nulonly = nulonly;
+       out1fmt("%s=%s\n", ap->name, single_quote(ap->val));
 }
 
-
 /*
- * Break the argument string into pieces based upon IFS and add the
- * strings to the argument list.  The regions of the string to be
- * searched for IFS characters have been stored by recordregion.
+ * TODO - sort output
  */
-static void
-ifsbreakup(char *string, struct arglist *arglist)
+static int
+aliascmd(int argc, char **argv)
 {
-       struct ifsregion *ifsp;
-       struct strlist *sp;
-       char *start;
-       char *p;
-       char *q;
-       const char *ifs, *realifs;
-       int ifsspc;
-       int nulonly;
+       char *n, *v;
+       int ret = 0;
+       struct alias *ap;
 
+       if (argc == 1) {
+               int i;
 
-       start = string;
-       if (ifslastp != NULL) {
-               ifsspc = 0;
-               nulonly = 0;
-               realifs = ifsset() ? ifsval() : defifs;
-               ifsp = &ifsfirst;
-               do {
-                       p = string + ifsp->begoff;
-                       nulonly = ifsp->nulonly;
-                       ifs = nulonly ? nullstr : realifs;
-                       ifsspc = 0;
-                       while (p < string + ifsp->endoff) {
-                               q = p;
-                               if (*p == CTLESC)
-                                       p++;
-                               if (strchr(ifs, *p)) {
-                                       if (!nulonly)
-                                               ifsspc = (strchr(defifs, *p) != NULL);
-                                       /* Ignore IFS whitespace at start */
-                                       if (q == start && ifsspc) {
-                                               p++;
-                                               start = p;
-                                               continue;
-                                       }
-                                       *q = '\0';
-                                       sp = (struct strlist *)stalloc(sizeof *sp);
-                                       sp->text = start;
-                                       *arglist->lastp = sp;
-                                       arglist->lastp = &sp->next;
-                                       p++;
-                                       if (!nulonly) {
-                                               for (;;) {
-                                                       if (p >= string + ifsp->endoff) {
-                                                               break;
-                                                       }
-                                                       q = p;
-                                                       if (*p == CTLESC)
-                                                               p++;
-                                                       if (strchr(ifs, *p) == NULL ) {
-                                                               p = q;
-                                                               break;
-                                                       } else if (strchr(defifs, *p) == NULL) {
-                                                               if (ifsspc) {
-                                                                       p++;
-                                                                       ifsspc = 0;
-                                                               } else {
-                                                                       p = q;
-                                                                       break;
-                                                               }
-                                                       } else
-                                                               p++;
-                                               }
-                                       }
-                                       start = p;
-                               } else
-                                       p++;
+               for (i = 0; i < ATABSIZE; i++)
+                       for (ap = atab[i]; ap; ap = ap->next) {
+                               printalias(ap);
                        }
-               } while ((ifsp = ifsp->next) != NULL);
-               if (nulonly)
-                       goto add;
+               return 0;
+       }
+       while ((n = *++argv) != NULL) {
+               v = strchr(n+1, '=');
+               if (v == NULL) { /* n+1: funny ksh stuff */
+                       ap = *__lookupalias(n);
+                       if (ap == NULL) {
+                               fprintf(stderr, "%s: %s not found\n", "alias", n);
+                               ret = 1;
+                       } else
+                               printalias(ap);
+               } else {
+                       *v++ = '\0';
+                       setalias(n, v);
+               }
        }
 
-       if (!*start)
-               return;
-
-add:
-       sp = (struct strlist *)stalloc(sizeof *sp);
-       sp->text = start;
-       *arglist->lastp = sp;
-       arglist->lastp = &sp->next;
+       return ret;
 }
 
-static void
-ifsfree(void)
+static int
+unaliascmd(int argc, char **argv)
 {
-       struct ifsregion *p;
+       int i;
 
-       INTOFF;
-       p = ifsfirst.next;
-       do {
-               struct ifsregion *ifsp;
-               ifsp = p->next;
-               ckfree(p);
-               p = ifsp;
-       } while (p);
-       ifslastp = NULL;
-       ifsfirst.next = NULL;
-       INTON;
+       while ((i = nextopt("a")) != '\0') {
+               if (i == 'a') {
+                       rmaliases();
+                       return 0;
+               }
+       }
+       for (i = 0; *argptr; argptr++) {
+               if (unalias(*argptr)) {
+                       fprintf(stderr, "%s: %s not found\n", "unalias", *argptr);
+                       i = 1;
+               }
+       }
+
+       return i;
 }
 
-static void expmeta(char *, char *);
-static struct strlist *expsort(struct strlist *);
-static struct strlist *msort(struct strlist *, int);
+#endif /* ASH_ALIAS */
 
-static char *expdir;
 
+/* ============ jobs.c */
 
-static void
-expandmeta(struct strlist *str, int flag)
-{
-       static const char metachars[] = {
-               '*', '?', '[', 0
-       };
-       /* TODO - EXP_REDIR */
+/* Mode argument to forkshell.  Don't change FORK_FG or FORK_BG. */
+#define FORK_FG 0
+#define FORK_BG 1
+#define FORK_NOJOB 2
 
-       while (str) {
-               struct strlist **savelastp;
-               struct strlist *sp;
-               char *p;
+/* mode flags for showjob(s) */
+#define SHOW_PGID       0x01    /* only show pgid - for jobs -p */
+#define SHOW_PID        0x04    /* include process pid */
+#define SHOW_CHANGED    0x08    /* only jobs whose state has changed */
 
-               if (fflag)
-                       goto nometa;
-               if (!strpbrk(str->text, metachars))
-                       goto nometa;
-               savelastp = exparg.lastp;
+/*
+ * A job structure contains information about a job.  A job is either a
+ * single process or a set of processes contained in a pipeline.  In the
+ * latter case, pidlist will be non-NULL, and will point to a -1 terminated
+ * array of pids.
+ */
 
-               INTOFF;
-               p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP);
-               {
-                       int i = strlen(str->text);
-                       expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
+struct procstat {
+       pid_t   pid;            /* process id */
+       int     status;         /* last process status from wait() */
+       char    *cmd;           /* text of command being run */
+};
+
+struct job {
+       struct procstat ps0;    /* status of process */
+       struct procstat *ps;    /* status or processes when more than one */
+#if JOBS
+       int stopstatus;         /* status of a stopped job */
+#endif
+       uint32_t
+               nprocs: 16,     /* number of processes */
+               state: 8,
+#define JOBRUNNING      0       /* at least one proc running */
+#define JOBSTOPPED      1       /* all procs are stopped */
+#define JOBDONE         2       /* all procs are completed */
+#if JOBS
+               sigint: 1,      /* job was killed by SIGINT */
+               jobctl: 1,      /* job running under job control */
+#endif
+               waited: 1,      /* true if this entry has been waited for */
+               used: 1,        /* true if this entry is in used */
+               changed: 1;     /* true if status has changed */
+       struct job *prev_job;   /* previous job */
+};
+
+static pid_t backgndpid;        /* pid of last background process */
+static smallint job_warning;    /* user was warned about stopped jobs (can be 2, 1 or 0). */
+
+static struct job *makejob(union node *, int);
+static int forkshell(struct job *, union node *, int);
+static int waitforjob(struct job *);
+
+#if !JOBS
+enum { jobctl = 0 };
+#define setjobctl(on) do {} while (0)
+#else
+static smallint jobctl;              /* true if doing job control */
+static void setjobctl(int);
+#endif
+
+/*
+ * Set the signal handler for the specified signal.  The routine figures
+ * out what it should be set to.
+ */
+static void
+setsignal(int signo)
+{
+       int action;
+       char *t, tsig;
+       struct sigaction act;
+
+       t = trap[signo];
+       if (t == NULL)
+               action = S_DFL;
+       else if (*t != '\0')
+               action = S_CATCH;
+       else
+               action = S_IGN;
+       if (rootshell && action == S_DFL) {
+               switch (signo) {
+               case SIGINT:
+                       if (iflag || minusc || sflag == 0)
+                               action = S_CATCH;
+                       break;
+               case SIGQUIT:
+#if DEBUG
+                       if (debug)
+                               break;
+#endif
+                       /* FALLTHROUGH */
+               case SIGTERM:
+                       if (iflag)
+                               action = S_IGN;
+                       break;
+#if JOBS
+               case SIGTSTP:
+               case SIGTTOU:
+                       if (mflag)
+                               action = S_IGN;
+                       break;
+#endif
                }
+       }
 
-               expmeta(expdir, p);
-               ckfree(expdir);
-               if (p != str->text)
-                       ckfree(p);
-               INTON;
-               if (exparg.lastp == savelastp) {
+       t = &sigmode[signo - 1];
+       tsig = *t;
+       if (tsig == 0) {
+               /*
+                * current setting unknown
+                */
+               if (sigaction(signo, 0, &act) == -1) {
                        /*
-                        * no matches
+                        * Pretend it worked; maybe we should give a warning
+                        * here, but other shells don't. We don't alter
+                        * sigmode, so that we retry every time.
                         */
-nometa:
-                       *exparg.lastp = str;
-                       rmescapes(str->text);
-                       exparg.lastp = &str->next;
+                       return;
+               }
+               if (act.sa_handler == SIG_IGN) {
+                       if (mflag
+                        && (signo == SIGTSTP || signo == SIGTTIN || signo == SIGTTOU)
+                       ) {
+                               tsig = S_IGN;   /* don't hard ignore these */
+                       } else
+                               tsig = S_HARD_IGN;
                } else {
-                       *exparg.lastp = NULL;
-                       *savelastp = sp = expsort(*savelastp);
-                       while (sp->next != NULL)
-                               sp = sp->next;
-                       exparg.lastp = &sp->next;
+                       tsig = S_RESET; /* force to be set */
                }
-               str = str->next;
        }
+       if (tsig == S_HARD_IGN || tsig == action)
+               return;
+       switch (action) {
+       case S_CATCH:
+               act.sa_handler = onsig;
+               break;
+       case S_IGN:
+               act.sa_handler = SIG_IGN;
+               break;
+       default:
+               act.sa_handler = SIG_DFL;
+       }
+       *t = action;
+       act.sa_flags = 0;
+       sigfillset(&act.sa_mask);
+       sigaction(signo, &act, 0);
 }
 
-/*
- * Add a file name to the list.
- */
+/* mode flags for set_curjob */
+#define CUR_DELETE 2
+#define CUR_RUNNING 1
+#define CUR_STOPPED 0
+
+/* mode flags for dowait */
+#define DOWAIT_NORMAL 0
+#define DOWAIT_BLOCK 1
+
+#if JOBS
+/* pgrp of shell on invocation */
+static int initialpgrp;
+static int ttyfd = -1;
+#endif
+/* array of jobs */
+static struct job *jobtab;
+/* size of array */
+static unsigned njobs;
+/* current job */
+static struct job *curjob;
+/* number of presumed living untracked jobs */
+static int jobless;
 
 static void
-addfname(const char *name)
+set_curjob(struct job *jp, unsigned mode)
 {
-       struct strlist *sp;
+       struct job *jp1;
+       struct job **jpp, **curp;
 
-       sp = (struct strlist *)stalloc(sizeof *sp);
-       sp->text = sstrdup(name);
-       *exparg.lastp = sp;
-       exparg.lastp = &sp->next;
+       /* first remove from list */
+       jpp = curp = &curjob;
+       do {
+               jp1 = *jpp;
+               if (jp1 == jp)
+                       break;
+               jpp = &jp1->prev_job;
+       } while (1);
+       *jpp = jp1->prev_job;
+
+       /* Then re-insert in correct position */
+       jpp = curp;
+       switch (mode) {
+       default:
+#if DEBUG
+               abort();
+#endif
+       case CUR_DELETE:
+               /* job being deleted */
+               break;
+       case CUR_RUNNING:
+               /* newly created job or backgrounded job,
+                  put after all stopped jobs. */
+               do {
+                       jp1 = *jpp;
+#if JOBS
+                       if (!jp1 || jp1->state != JOBSTOPPED)
+#endif
+                               break;
+                       jpp = &jp1->prev_job;
+               } while (1);
+               /* FALLTHROUGH */
+#if JOBS
+       case CUR_STOPPED:
+#endif
+               /* newly stopped job - becomes curjob */
+               jp->prev_job = *jpp;
+               *jpp = jp;
+               break;
+       }
 }
 
+#if JOBS || DEBUG
+static int
+jobno(const struct job *jp)
+{
+       return jp - jobtab + 1;
+}
+#endif
 
 /*
- * Do metacharacter (i.e. *, ?, [...]) expansion.
+ * Convert a job name to a job structure.
  */
-
-static void
-expmeta(char *enddir, char *name)
+static struct job *
+getjob(const char *name, int getctl)
 {
-       char *p;
-       const char *cp;
-       char *start;
-       char *endname;
-       int metaflag;
-       struct stat statb;
-       DIR *dirp;
-       struct dirent *dp;
-       int atend;
-       int matchdot;
+       struct job *jp;
+       struct job *found;
+       const char *err_msg = "No such job: %s";
+       unsigned num;
+       int c;
+       const char *p;
+       char *(*match)(const char *, const char *);
 
-       metaflag = 0;
-       start = name;
-       for (p = name; *p; p++) {
-               if (*p == '*' || *p == '?')
-                       metaflag = 1;
-               else if (*p == '[') {
-                       char *q = p + 1;
-                       if (*q == '!')
-                               q++;
-                       for (;;) {
-                               if (*q == '\\')
-                                       q++;
-                               if (*q == '/' || *q == '\0')
-                                       break;
-                               if (*++q == ']') {
-                                       metaflag = 1;
-                                       break;
-                               }
-                       }
-               } else if (*p == '\\')
-                       p++;
-               else if (*p == '/') {
-                       if (metaflag)
-                               goto out;
-                       start = p + 1;
+       jp = curjob;
+       p = name;
+       if (!p)
+               goto currentjob;
+
+       if (*p != '%')
+               goto err;
+
+       c = *++p;
+       if (!c)
+               goto currentjob;
+
+       if (!p[1]) {
+               if (c == '+' || c == '%') {
+ currentjob:
+                       err_msg = "No current job";
+                       goto check;
+               }
+               if (c == '-') {
+                       if (jp)
+                               jp = jp->prev_job;
+                       err_msg = "No previous job";
+ check:
+                       if (!jp)
+                               goto err;
+                       goto gotit;
                }
        }
-out:
-       if (metaflag == 0) {    /* we've reached the end of the file name */
-               if (enddir != expdir)
-                       metaflag++;
-               p = name;
-               do {
-                       if (*p == '\\')
-                               p++;
-                       *enddir++ = *p;
-               } while (*p++);
-               if (metaflag == 0 || lstat(expdir, &statb) >= 0)
-                       addfname(expdir);
-               return;
-       }
-       endname = p;
-       if (name < start) {
-               p = name;
-               do {
-                       if (*p == '\\')
-                               p++;
-                       *enddir++ = *p++;
-               } while (p < start);
-       }
-       if (enddir == expdir) {
-               cp = ".";
-       } else if (enddir == expdir + 1 && *expdir == '/') {
-               cp = "/";
-       } else {
-               cp = expdir;
-               enddir[-1] = '\0';
-       }
-       if ((dirp = opendir(cp)) == NULL)
-               return;
-       if (enddir != expdir)
-               enddir[-1] = '/';
-       if (*endname == 0) {
-               atend = 1;
-       } else {
-               atend = 0;
-               *endname++ = '\0';
+
+       if (is_number(p)) {
+               num = atoi(p);
+               if (num < njobs) {
+                       jp = jobtab + num - 1;
+                       if (jp->used)
+                               goto gotit;
+                       goto err;
+               }
        }
-       matchdot = 0;
-       p = start;
-       if (*p == '\\')
+
+       match = prefix;
+       if (*p == '?') {
+               match = strstr;
                p++;
-       if (*p == '.')
-               matchdot++;
-       while (! intpending && (dp = readdir(dirp)) != NULL) {
-               if (dp->d_name[0] == '.' && ! matchdot)
-                       continue;
-               if (pmatch(start, dp->d_name)) {
-                       if (atend) {
-                               scopy(dp->d_name, enddir);
-                               addfname(expdir);
-                       } else {
-                               for (p = enddir, cp = dp->d_name;
-                                    (*p++ = *cp++) != '\0';)
-                                       continue;
-                               p[-1] = '/';
-                               expmeta(p, endname);
-                       }
+       }
+
+       found = 0;
+       while (1) {
+               if (!jp)
+                       goto err;
+               if (match(jp->ps[0].cmd, p)) {
+                       if (found)
+                               goto err;
+                       found = jp;
+                       err_msg = "%s: ambiguous";
                }
+               jp = jp->prev_job;
        }
-       closedir(dirp);
-       if (! atend)
-               endname[-1] = '/';
+
+ gotit:
+#if JOBS
+       err_msg = "job %s not created under job control";
+       if (getctl && jp->jobctl == 0)
+               goto err;
+#endif
+       return jp;
+ err:
+       ash_msg_and_raise_error(err_msg, name);
 }
 
 /*
- * Sort the results of file name expansion.  It calculates the number of
- * strings to sort and then calls msort (short for merge sort) to do the
- * work.
+ * Mark a job structure as unused.
  */
-
-static struct strlist *
-expsort(struct strlist *str)
+static void
+freejob(struct job *jp)
 {
-       int len;
-       struct strlist *sp;
+       struct procstat *ps;
+       int i;
 
-       len = 0;
-       for (sp = str ; sp ; sp = sp->next)
-               len++;
-       return msort(str, len);
+       INT_OFF;
+       for (i = jp->nprocs, ps = jp->ps; --i >= 0; ps++) {
+               if (ps->cmd != nullstr)
+                       free(ps->cmd);
+       }
+       if (jp->ps != &jp->ps0)
+               free(jp->ps);
+       jp->used = 0;
+       set_curjob(jp, CUR_DELETE);
+       INT_ON;
 }
 
+#if JOBS
+static void
+xtcsetpgrp(int fd, pid_t pgrp)
+{
+       if (tcsetpgrp(fd, pgrp))
+               ash_msg_and_raise_error("cannot set tty process group (%m)");
+}
 
-static struct strlist *
-msort(struct strlist *list, int len)
+/*
+ * Turn job control on and off.
+ *
+ * Note:  This code assumes that the third arg to ioctl is a character
+ * pointer, which is true on Berkeley systems but not System V.  Since
+ * System V doesn't have job control yet, this isn't a problem now.
+ *
+ * Called with interrupts off.
+ */
+static void
+setjobctl(int on)
 {
-       struct strlist *p, *q = NULL;
-       struct strlist **lpp;
-       int half;
-       int n;
+       int fd;
+       int pgrp;
 
-       if (len <= 1)
-               return list;
-       half = len >> 1;
-       p = list;
-       for (n = half ; --n >= 0 ; ) {
-               q = p;
-               p = p->next;
-       }
-       q->next = NULL;                 /* terminate first half of list */
-       q = msort(list, half);          /* sort first half of list */
-       p = msort(p, len - half);               /* sort second half */
-       lpp = &list;
-       for (;;) {
-#ifdef CONFIG_LOCALE_SUPPORT
-               if (strcoll(p->text, q->text) < 0)
-#else
-               if (strcmp(p->text, q->text) < 0)
-#endif
-                                               {
-                       *lpp = p;
-                       lpp = &p->next;
-                       if ((p = *lpp) == NULL) {
-                               *lpp = q;
-                               break;
+       if (on == jobctl || rootshell == 0)
+               return;
+       if (on) {
+               int ofd;
+               ofd = fd = open(_PATH_TTY, O_RDWR);
+               if (fd < 0) {
+       /* BTW, bash will try to open(ttyname(0)) if open("/dev/tty") fails.
+        * That sometimes helps to acquire controlling tty.
+        * Obviously, a workaround for bugs when someone
+        * failed to provide a controlling tty to bash! :) */
+                       fd += 3;
+                       while (!isatty(fd) && --fd >= 0)
+                               ;
+               }
+               fd = fcntl(fd, F_DUPFD, 10);
+               close(ofd);
+               if (fd < 0)
+                       goto out;
+               close_on_exec_on(fd);
+               do { /* while we are in the background */
+                       pgrp = tcgetpgrp(fd);
+                       if (pgrp < 0) {
+ out:
+                               ash_msg("can't access tty; job control turned off");
+                               mflag = on = 0;
+                               goto close;
                        }
-               } else {
-                       *lpp = q;
-                       lpp = &q->next;
-                       if ((q = *lpp) == NULL) {
-                               *lpp = p;
+                       if (pgrp == getpgrp())
                                break;
+                       killpg(0, SIGTTIN);
+               } while (1);
+               initialpgrp = pgrp;
+
+               setsignal(SIGTSTP);
+               setsignal(SIGTTOU);
+               setsignal(SIGTTIN);
+               pgrp = rootpid;
+               setpgid(0, pgrp);
+               xtcsetpgrp(fd, pgrp);
+       } else {
+               /* turning job control off */
+               fd = ttyfd;
+               pgrp = initialpgrp;
+               /* was xtcsetpgrp, but this can make exiting ash
+                * with pty already deleted loop forever */
+               tcsetpgrp(fd, pgrp);
+               setpgid(0, pgrp);
+               setsignal(SIGTSTP);
+               setsignal(SIGTTOU);
+               setsignal(SIGTTIN);
+ close:
+               close(fd);
+               fd = -1;
+       }
+       ttyfd = fd;
+       jobctl = on;
+}
+
+static int
+killcmd(int argc, char **argv)
+{
+       if (argv[1] && strcmp(argv[1], "-l") != 0) {
+               int i = 1;
+               do {
+                       if (argv[i][0] == '%') {
+                               struct job *jp = getjob(argv[i], 0);
+                               unsigned pid = jp->ps[0].pid;
+                               /* Enough space for ' -NNN<nul>' */
+                               argv[i] = alloca(sizeof(int)*3 + 3);
+                               /* kill_main has matching code to expect
+                                * leading space. Needed to not confuse
+                                * negative pids with "kill -SIGNAL_NO" syntax */
+                               sprintf(argv[i], " -%u", pid);
                        }
-               }
+               } while (argv[++i]);
        }
-       return list;
+       return kill_main(argc, argv);
 }
 
+static void
+showpipe(struct job *jp, FILE *out)
+{
+       struct procstat *sp;
+       struct procstat *spend;
+
+       spend = jp->ps + jp->nprocs;
+       for (sp = jp->ps + 1; sp < spend; sp++)
+               fprintf(out, " | %s", sp->cmd);
+       outcslow('\n', out);
+       flush_stdout_stderr();
+}
 
-/*
- * Returns true if the pattern matches the string.
- */
 
-static int patmatch(char *pattern, const char *string)
+static int
+restartjob(struct job *jp, int mode)
 {
-       return pmatch(preglob(pattern, 0, 0), string);
+       struct procstat *ps;
+       int i;
+       int status;
+       pid_t pgid;
+
+       INT_OFF;
+       if (jp->state == JOBDONE)
+               goto out;
+       jp->state = JOBRUNNING;
+       pgid = jp->ps->pid;
+       if (mode == FORK_FG)
+               xtcsetpgrp(ttyfd, pgid);
+       killpg(pgid, SIGCONT);
+       ps = jp->ps;
+       i = jp->nprocs;
+       do {
+               if (WIFSTOPPED(ps->status)) {
+                       ps->status = -1;
+               }
+               ps++;
+       } while (--i);
+ out:
+       status = (mode == FORK_FG) ? waitforjob(jp) : 0;
+       INT_ON;
+       return status;
 }
 
+static int
+fg_bgcmd(int argc, char **argv)
+{
+       struct job *jp;
+       FILE *out;
+       int mode;
+       int retval;
 
-/*
- * Remove any CTLESC characters from a string.
- */
+       mode = (**argv == 'f') ? FORK_FG : FORK_BG;
+       nextopt(nullstr);
+       argv = argptr;
+       out = stdout;
+       do {
+               jp = getjob(*argv, 1);
+               if (mode == FORK_BG) {
+                       set_curjob(jp, CUR_RUNNING);
+                       fprintf(out, "[%d] ", jobno(jp));
+               }
+               outstr(jp->ps->cmd, out);
+               showpipe(jp, out);
+               retval = restartjob(jp, mode);
+       } while (*argv && *++argv);
+       return retval;
+}
+#endif
 
-static char *
-_rmescapes(char *str, int flag)
+static int
+sprint_status(char *s, int status, int sigonly)
 {
-       char *p, *q, *r;
-       static const char qchars[] = { CTLESC, CTLQUOTEMARK, 0 };
-       unsigned inquotes;
-       int notescaped;
-       int globbing;
-
-       p = strpbrk(str, qchars);
-       if (!p) {
-               return str;
-       }
-       q = p;
-       r = str;
-       if (flag & RMESCAPE_ALLOC) {
-               size_t len = p - str;
-               size_t fulllen = len + strlen(p) + 1;
+       int col;
+       int st;
 
-               if (flag & RMESCAPE_GROW) {
-                       r = makestrspace(fulllen, expdest);
-               } else if (flag & RMESCAPE_HEAP) {
-                       r = ckmalloc(fulllen);
-               } else {
-                       r = stalloc(fulllen);
-               }
-               q = r;
-               if (len > 0) {
-                       q = mempcpy(q, str, len);
-               }
-       }
-       inquotes = (flag & RMESCAPE_QUOTED) ^ RMESCAPE_QUOTED;
-       globbing = flag & RMESCAPE_GLOB;
-       notescaped = globbing;
-       while (*p) {
-               if (*p == CTLQUOTEMARK) {
-                       inquotes = ~inquotes;
-                       p++;
-                       notescaped = globbing;
-                       continue;
-               }
-               if (*p == '\\') {
-                       /* naked back slash */
-                       notescaped = 0;
-                       goto copy;
-               }
-               if (*p == CTLESC) {
-                       p++;
-                       if (notescaped && inquotes && *p != '/') {
-                               *q++ = '\\';
-                       }
+       col = 0;
+       if (!WIFEXITED(status)) {
+#if JOBS
+               if (WIFSTOPPED(status))
+                       st = WSTOPSIG(status);
+               else
+#endif
+                       st = WTERMSIG(status);
+               if (sigonly) {
+                       if (st == SIGINT || st == SIGPIPE)
+                               goto out;
+#if JOBS
+                       if (WIFSTOPPED(status))
+                               goto out;
+#endif
                }
-               notescaped = globbing;
-copy:
-               *q++ = *p++;
-       }
-       *q = '\0';
-       if (flag & RMESCAPE_GROW) {
-               expdest = r;
-               STADJUST(q - r + 1, expdest);
+               st &= 0x7f;
+               col = fmtstr(s, 32, strsignal(st));
+               if (WCOREDUMP(status)) {
+                       col += fmtstr(s + col, 16, " (core dumped)");
+               }
+       } else if (!sigonly) {
+               st = WEXITSTATUS(status);
+               if (st)
+                       col = fmtstr(s, 16, "Done(%d)", st);
+               else
+                       col = fmtstr(s, 16, "Done");
        }
-       return r;
+ out:
+       return col;
 }
 
-
 /*
- * See if a pattern matches in a case statement.
+ * Do a wait system call.  If job control is compiled in, we accept
+ * stopped processes.  If block is zero, we return a value of zero
+ * rather than blocking.
+ *
+ * System V doesn't have a non-blocking wait system call.  It does
+ * have a SIGCLD signal that is sent to a process when one of it's
+ * children dies.  The obvious way to use SIGCLD would be to install
+ * a handler for SIGCLD which simply bumped a counter when a SIGCLD
+ * was received, and have waitproc bump another counter when it got
+ * the status of a process.  Waitproc would then know that a wait
+ * system call would not block if the two counters were different.
+ * This approach doesn't work because if a process has children that
+ * have not been waited for, System V will send it a SIGCLD when it
+ * installs a signal handler for SIGCLD.  What this means is that when
+ * a child exits, the shell will be sent SIGCLD signals continuously
+ * until is runs out of stack space, unless it does a wait call before
+ * restoring the signal handler.  The code below takes advantage of
+ * this (mis)feature by installing a signal handler for SIGCLD and
+ * then checking to see whether it was called.  If there are any
+ * children to be waited for, it will be.
+ *
+ * If neither SYSV nor BSD is defined, we don't implement nonblocking
+ * waits at all.  In this case, the user will not be informed when
+ * a background process until the next time she runs a real program
+ * (as opposed to running a builtin command or just typing return),
+ * and the jobs command may give out of date information.
  */
-
-int
-casematch(union node *pattern, char *val)
+static int
+waitproc(int block, int *status)
 {
-       struct stackmark smark;
-       int result;
+       int flags = 0;
 
-       setstackmark(&smark);
-       argbackq = pattern->narg.backquote;
-       STARTSTACKSTR(expdest);
-       ifslastp = NULL;
-       argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
-       STACKSTRNUL(expdest);
-       result = patmatch(stackblock(), val);
-       popstackmark(&smark);
-       return result;
+#if JOBS
+       if (jobctl)
+               flags |= WUNTRACED;
+#endif
+       if (block == 0)
+               flags |= WNOHANG;
+       return wait3(status, flags, (struct rusage *)NULL);
 }
 
 /*
- * Our own itoa().
+ * Wait for a process to terminate.
  */
-
 static int
-cvtnum(arith_t num)
+dowait(int block, struct job *job)
 {
-       int len;
+       int pid;
+       int status;
+       struct job *jp;
+       struct job *thisjob;
+       int state;
 
-       expdest = makestrspace(32, expdest);
-#ifdef CONFIG_ASH_MATH_SUPPORT_64
-       len = fmtstr(expdest, 32, "%lld", (long long) num);
-#else
-       len = fmtstr(expdest, 32, "%ld", num);
+       TRACE(("dowait(%d) called\n", block));
+       pid = waitproc(block, &status);
+       TRACE(("wait returns pid %d, status=%d\n", pid, status));
+       if (pid <= 0)
+               return pid;
+       INT_OFF;
+       thisjob = NULL;
+       for (jp = curjob; jp; jp = jp->prev_job) {
+               struct procstat *sp;
+               struct procstat *spend;
+               if (jp->state == JOBDONE)
+                       continue;
+               state = JOBDONE;
+               spend = jp->ps + jp->nprocs;
+               sp = jp->ps;
+               do {
+                       if (sp->pid == pid) {
+                               TRACE(("Job %d: changing status of proc %d "
+                                       "from 0x%x to 0x%x\n",
+                                       jobno(jp), pid, sp->status, status));
+                               sp->status = status;
+                               thisjob = jp;
+                       }
+                       if (sp->status == -1)
+                               state = JOBRUNNING;
+#if JOBS
+                       if (state == JOBRUNNING)
+                               continue;
+                       if (WIFSTOPPED(sp->status)) {
+                               jp->stopstatus = sp->status;
+                               state = JOBSTOPPED;
+                       }
 #endif
-       STADJUST(len, expdest);
-       return len;
+               } while (++sp < spend);
+               if (thisjob)
+                       goto gotjob;
+       }
+#if JOBS
+       if (!WIFSTOPPED(status))
+#endif
+
+               jobless--;
+       goto out;
+
+ gotjob:
+       if (state != JOBRUNNING) {
+               thisjob->changed = 1;
+
+               if (thisjob->state != state) {
+                       TRACE(("Job %d: changing state from %d to %d\n",
+                               jobno(thisjob), thisjob->state, state));
+                       thisjob->state = state;
+#if JOBS
+                       if (state == JOBSTOPPED) {
+                               set_curjob(thisjob, CUR_STOPPED);
+                       }
+#endif
+               }
+       }
+
+ out:
+       INT_ON;
+
+       if (thisjob && thisjob == job) {
+               char s[48 + 1];
+               int len;
+
+               len = sprint_status(s, status, 1);
+               if (len) {
+                       s[len] = '\n';
+                       s[len + 1] = 0;
+                       out2str(s);
+               }
+       }
+       return pid;
 }
 
+#if JOBS
 static void
-varunset(const char *end, const char *var, const char *umsg, int varflags)
+showjob(FILE *out, struct job *jp, int mode)
 {
-       const char *msg;
-       const char *tail;
+       struct procstat *ps;
+       struct procstat *psend;
+       int col;
+       int indent_col;
+       char s[80];
 
-       tail = nullstr;
-       msg = "parameter not set";
-       if (umsg) {
-               if (*end == CTLENDVAR) {
-                       if (varflags & VSNUL)
-                               tail = " or null";
-               } else
-                       msg = umsg;
+       ps = jp->ps;
+
+       if (mode & SHOW_PGID) {
+               /* just output process (group) id of pipeline */
+               fprintf(out, "%d\n", ps->pid);
+               return;
        }
-       sh_error("%.*s: %s%s", end - var - 1, var, msg, tail);
-}
 
+       col = fmtstr(s, 16, "[%d]   ", jobno(jp));
+       indent_col = col;
 
-/*      input.c      */
+       if (jp == curjob)
+               s[col - 2] = '+';
+       else if (curjob && jp == curjob->prev_job)
+               s[col - 2] = '-';
 
-/*
- * This implements the input routines used by the parser.
- */
+       if (mode & SHOW_PID)
+               col += fmtstr(s + col, 16, "%d ", ps->pid);
 
-#define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
+       psend = ps + jp->nprocs;
 
-static void pushfile(void);
+       if (jp->state == JOBRUNNING) {
+               strcpy(s + col, "Running");
+               col += sizeof("Running") - 1;
+       } else {
+               int status = psend[-1].status;
+               if (jp->state == JOBSTOPPED)
+                       status = jp->stopstatus;
+               col += sprint_status(s + col, status, 0);
+       }
 
-/*
- * Read a character from the script, returning PEOF on end of file.
- * Nul characters in the input are silently discarded.
- */
+       goto start;
 
+       do {
+               /* for each process */
+               col = fmtstr(s, 48, " |\n%*c%d ", indent_col, ' ', ps->pid) - 3;
+ start:
+               fprintf(out, "%s%*c%s",
+                       s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd
+               );
+               if (!(mode & SHOW_PID)) {
+                       showpipe(jp, out);
+                       break;
+               }
+               if (++ps == psend) {
+                       outcslow('\n', out);
+                       break;
+               }
+       } while (1);
 
-#define pgetc_as_macro()   (--parsenleft >= 0? SC2INT(*parsenextc++) : preadbuffer())
+       jp->changed = 0;
 
-#ifdef CONFIG_ASH_OPTIMIZE_FOR_SIZE
-#define pgetc_macro() pgetc()
-static int
-pgetc(void)
-{
-       return pgetc_as_macro();
-}
-#else
-#define pgetc_macro()   pgetc_as_macro()
-static int
-pgetc(void)
-{
-       return pgetc_macro();
+       if (jp->state == JOBDONE) {
+               TRACE(("showjob: freeing job %d\n", jobno(jp)));
+               freejob(jp);
+       }
 }
-#endif
-
 
 /*
- * Same as pgetc(), but ignores PEOA.
+ * Print a list of jobs.  If "change" is nonzero, only print jobs whose
+ * statuses have changed since the last call to showjobs.
  */
-#ifdef CONFIG_ASH_ALIAS
-static int pgetc2(void)
-{
-       int c;
-
-       do {
-               c = pgetc_macro();
-       } while (c == PEOA);
-       return c;
-}
-#else
-static int pgetc2(void)
+static void
+showjobs(FILE *out, int mode)
 {
-       return pgetc_macro();
-}
-#endif
+       struct job *jp;
 
-/*
- * Read a line from the script.
- */
+       TRACE(("showjobs(%x) called\n", mode));
 
-static char * pfgets(char *line, int len)
-{
-       char *p = line;
-       int nleft = len;
-       int c;
+       /* If not even one one job changed, there is nothing to do */
+       while (dowait(DOWAIT_NORMAL, NULL) > 0)
+               continue;
 
-       while (--nleft > 0) {
-               c = pgetc2();
-               if (c == PEOF) {
-                       if (p == line)
-                               return NULL;
-                       break;
+       for (jp = curjob; jp; jp = jp->prev_job) {
+               if (!(mode & SHOW_CHANGED) || jp->changed) {
+                       showjob(out, jp, mode);
                }
-               *p++ = c;
-               if (c == '\n')
-                       break;
        }
-       *p = '\0';
-       return line;
 }
 
+static int
+jobscmd(int argc, char **argv)
+{
+       int mode, m;
 
+       mode = 0;
+       while ((m = nextopt("lp"))) {
+               if (m == 'l')
+                       mode = SHOW_PID;
+               else
+                       mode = SHOW_PGID;
+       }
 
-#ifdef CONFIG_FEATURE_COMMAND_EDITING
-#ifdef CONFIG_ASH_EXPAND_PRMT
-static char *cmdedit_prompt;
-#else
-static const char *cmdedit_prompt;
-#endif
-static void putprompt(const char *s)
-{
-#ifdef CONFIG_ASH_EXPAND_PRMT
-       free(cmdedit_prompt);
-       cmdedit_prompt = xstrdup(s);
-#else
-       cmdedit_prompt = s;
-#endif
-}
-#else
-static void putprompt(const char *s)
-{
-       out2str(s);
+       argv = argptr;
+       if (*argv) {
+               do
+                       showjob(stdout, getjob(*argv,0), mode);
+               while (*++argv);
+       } else
+               showjobs(stdout, mode);
+
+       return 0;
 }
-#endif
+#endif /* JOBS */
 
-static int preadfd(void)
+static int
+getstatus(struct job *job)
 {
-       int nr;
-       char *buf =  parsefile->buf;
-       parsenextc = buf;
+       int status;
+       int retval;
 
-retry:
-#ifdef CONFIG_FEATURE_COMMAND_EDITING
-       if (!iflag || parsefile->fd)
-               nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
-       else {
-#ifdef CONFIG_FEATURE_COMMAND_TAB_COMPLETION
-               cmdedit_path_lookup = pathval();
+       status = job->ps[job->nprocs - 1].status;
+       retval = WEXITSTATUS(status);
+       if (!WIFEXITED(status)) {
+#if JOBS
+               retval = WSTOPSIG(status);
+               if (!WIFSTOPPED(status))
+#endif
+               {
+                       /* XXX: limits number of signals */
+                       retval = WTERMSIG(status);
+#if JOBS
+                       if (retval == SIGINT)
+                               job->sigint = 1;
 #endif
-               nr = cmdedit_read_input((char *) cmdedit_prompt, buf);
-               if(nr == 0) {
-                       /* Ctrl+C presend */
-                       if(trap[SIGINT]) {
-                               buf[0] = '\n';
-                               buf[1] = 0;
-                               raise(SIGINT);
-                               return 1;
-                       }
-                       goto retry;
-               }
-               if(nr < 0 && errno == 0) {
-                       /* Ctrl+D presend */
-                       nr = 0;
                }
+               retval += 128;
        }
-#else
-       nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
-#endif
+       TRACE(("getstatus: job %d, nproc %d, status %x, retval %x\n",
+               jobno(job), job->nprocs, status, retval));
+       return retval;
+}
 
-       if (nr < 0) {
-               if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
-                       int flags = fcntl(0, F_GETFL, 0);
-                       if (flags >= 0 && flags & O_NONBLOCK) {
-                               flags &=~ O_NONBLOCK;
-                               if (fcntl(0, F_SETFL, flags) >= 0) {
-                                       out2str("sh: turning off NDELAY mode\n");
-                                       goto retry;
+static int
+waitcmd(int argc, char **argv)
+{
+       struct job *job;
+       int retval;
+       struct job *jp;
+
+       EXSIGON;
+
+       nextopt(nullstr);
+       retval = 0;
+
+       argv = argptr;
+       if (!*argv) {
+               /* wait for all jobs */
+               for (;;) {
+                       jp = curjob;
+                       while (1) {
+                               if (!jp) {
+                                       /* no running procs */
+                                       goto out;
                                }
+                               if (jp->state == JOBRUNNING)
+                                       break;
+                               jp->waited = 1;
+                               jp = jp->prev_job;
                        }
+                       dowait(DOWAIT_BLOCK, 0);
                }
        }
-       return nr;
-}
 
-/*
- * Refill the input buffer and return the next input character:
- *
- * 1) If a string was pushed back on the input, pop it;
- * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
- *    from a string so we can't refill the buffer, return EOF.
- * 3) If the is more stuff in this buffer, use it else call read to fill it.
- * 4) Process input up to the next newline, deleting nul characters.
- */
+       retval = 127;
+       do {
+               if (**argv != '%') {
+                       pid_t pid = number(*argv);
+                       job = curjob;
+                       goto start;
+                       do {
+                               if (job->ps[job->nprocs - 1].pid == pid)
+                                       break;
+                               job = job->prev_job;
+ start:
+                               if (!job)
+                                       goto repeat;
+                       } while (1);
+               } else
+                       job = getjob(*argv, 0);
+               /* loop until process terminated or stopped */
+               while (job->state == JOBRUNNING)
+                       dowait(DOWAIT_BLOCK, 0);
+               job->waited = 1;
+               retval = getstatus(job);
+ repeat:
+               ;
+       } while (*++argv);
 
-int
-preadbuffer(void)
+ out:
+       return retval;
+}
+
+static struct job *
+growjobtab(void)
 {
-       char *q;
-       int more;
-       char savec;
+       size_t len;
+       ptrdiff_t offset;
+       struct job *jp, *jq;
 
-       while (parsefile->strpush) {
-#ifdef CONFIG_ASH_ALIAS
-               if (parsenleft == -1 && parsefile->strpush->ap &&
-                       parsenextc[-1] != ' ' && parsenextc[-1] != '\t') {
-                       return PEOA;
-               }
-#endif
-               popstring();
-               if (--parsenleft >= 0)
-                       return SC2INT(*parsenextc++);
-       }
-       if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
-               return PEOF;
-       flushall();
+       len = njobs * sizeof(*jp);
+       jq = jobtab;
+       jp = ckrealloc(jq, len + 4 * sizeof(*jp));
 
-       more = parselleft;
-       if (more <= 0) {
-again:
-               if ((more = preadfd()) <= 0) {
-                       parselleft = parsenleft = EOF_NLEFT;
-                       return PEOF;
+       offset = (char *)jp - (char *)jq;
+       if (offset) {
+               /* Relocate pointers */
+               size_t l = len;
+
+               jq = (struct job *)((char *)jq + l);
+               while (l) {
+                       l -= sizeof(*jp);
+                       jq--;
+#define joff(p) ((struct job *)((char *)(p) + l))
+#define jmove(p) (p) = (void *)((char *)(p) + offset)
+                       if (joff(jp)->ps == &jq->ps0)
+                               jmove(joff(jp)->ps);
+                       if (joff(jp)->prev_job)
+                               jmove(joff(jp)->prev_job);
                }
+               if (curjob)
+                       jmove(curjob);
+#undef joff
+#undef jmove
        }
 
-       q = parsenextc;
-
-       /* delete nul characters */
-       for (;;) {
-               int c;
-
-               more--;
-               c = *q;
+       njobs += 4;
+       jobtab = jp;
+       jp = (struct job *)((char *)jp + len);
+       jq = jp + 3;
+       do {
+               jq->used = 0;
+       } while (--jq >= jp);
+       return jp;
+}
 
-               if (!c)
-                       memmove(q, q + 1, more);
-               else {
-                       q++;
-                       if (c == '\n') {
-                               parsenleft = q - parsenextc - 1;
-                               break;
-                       }
-               }
+/*
+ * Return a new job structure.
+ * Called with interrupts off.
+ */
+static struct job *
+makejob(union node *node, int nprocs)
+{
+       int i;
+       struct job *jp;
 
-               if (more <= 0) {
-                       parsenleft = q - parsenextc - 1;
-                       if (parsenleft < 0)
-                               goto again;
+       for (i = njobs, jp = jobtab; ; jp++) {
+               if (--i < 0) {
+                       jp = growjobtab();
                        break;
                }
+               if (jp->used == 0)
+                       break;
+               if (jp->state != JOBDONE || !jp->waited)
+                       continue;
+#if JOBS
+               if (jobctl)
+                       continue;
+#endif
+               freejob(jp);
+               break;
        }
-       parselleft = more;
-
-       savec = *q;
-       *q = '\0';
-
-       if (vflag) {
-               out2str(parsenextc);
+       memset(jp, 0, sizeof(*jp));
+#if JOBS
+       /* jp->jobctl is a bitfield.
+        * "jp->jobctl |= jobctl" likely to give awful code */
+       if (jobctl)
+               jp->jobctl = 1;
+#endif
+       jp->prev_job = curjob;
+       curjob = jp;
+       jp->used = 1;
+       jp->ps = &jp->ps0;
+       if (nprocs > 1) {
+               jp->ps = ckmalloc(nprocs * sizeof(struct procstat));
        }
-
-       *q = savec;
-
-       return SC2INT(*parsenextc++);
+       TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
+                               jobno(jp)));
+       return jp;
 }
 
+#if JOBS
 /*
- * Undo the last call to pgetc.  Only one character may be pushed back.
- * PEOF may be pushed back.
+ * Return a string identifying a command (to be printed by the
+ * jobs command).
  */
+static char *cmdnextc;
 
-void
-pungetc(void)
+static void
+cmdputs(const char *s)
 {
-       parsenleft++;
-       parsenextc--;
+       const char *p, *str;
+       char c, cc[2] = " ";
+       char *nextc;
+       int subtype = 0;
+       int quoted = 0;
+       static const char vstype[VSTYPE + 1][4] = {
+               "", "}", "-", "+", "?", "=",
+               "%", "%%", "#", "##"
+       };
+
+       nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc);
+       p = s;
+       while ((c = *p++) != 0) {
+               str = 0;
+               switch (c) {
+               case CTLESC:
+                       c = *p++;
+                       break;
+               case CTLVAR:
+                       subtype = *p++;
+                       if ((subtype & VSTYPE) == VSLENGTH)
+                               str = "${#";
+                       else
+                               str = "${";
+                       if (!(subtype & VSQUOTE) == !(quoted & 1))
+                               goto dostr;
+                       quoted ^= 1;
+                       c = '"';
+                       break;
+               case CTLENDVAR:
+                       str = "\"}" + !(quoted & 1);
+                       quoted >>= 1;
+                       subtype = 0;
+                       goto dostr;
+               case CTLBACKQ:
+                       str = "$(...)";
+                       goto dostr;
+               case CTLBACKQ+CTLQUOTE:
+                       str = "\"$(...)\"";
+                       goto dostr;
+#if ENABLE_ASH_MATH_SUPPORT
+               case CTLARI:
+                       str = "$((";
+                       goto dostr;
+               case CTLENDARI:
+                       str = "))";
+                       goto dostr;
+#endif
+               case CTLQUOTEMARK:
+                       quoted ^= 1;
+                       c = '"';
+                       break;
+               case '=':
+                       if (subtype == 0)
+                               break;
+                       if ((subtype & VSTYPE) != VSNORMAL)
+                               quoted <<= 1;
+                       str = vstype[subtype & VSTYPE];
+                       if (subtype & VSNUL)
+                               c = ':';
+                       else
+                               goto checkstr;
+                       break;
+               case '\'':
+               case '\\':
+               case '"':
+               case '$':
+                       /* These can only happen inside quotes */
+                       cc[0] = c;
+                       str = cc;
+                       c = '\\';
+                       break;
+               default:
+                       break;
+               }
+               USTPUTC(c, nextc);
+ checkstr:
+               if (!str)
+                       continue;
+ dostr:
+               while ((c = *str++)) {
+                       USTPUTC(c, nextc);
+               }
+       }
+       if (quoted & 1) {
+               USTPUTC('"', nextc);
+       }
+       *nextc = 0;
+       cmdnextc = nextc;
 }
 
-/*
- * Push a string back onto the input at this current parsefile level.
- * We handle aliases this way.
- */
-void
-pushstring(char *s, void *ap)
-{
-       struct strpush *sp;
-       size_t len;
+/* cmdtxt() and cmdlist() call each other */
+static void cmdtxt(union node *n);
 
-       len = strlen(s);
-       INTOFF;
-/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
-       if (parsefile->strpush) {
-               sp = ckmalloc(sizeof (struct strpush));
-               sp->prev = parsefile->strpush;
-               parsefile->strpush = sp;
-       } else
-               sp = parsefile->strpush = &(parsefile->basestrpush);
-       sp->prevstring = parsenextc;
-       sp->prevnleft = parsenleft;
-#ifdef CONFIG_ASH_ALIAS
-       sp->ap = (struct alias *)ap;
-       if (ap) {
-               ((struct alias *)ap)->flag |= ALIASINUSE;
-               sp->string = s;
+static void
+cmdlist(union node *np, int sep)
+{
+       for (; np; np = np->narg.next) {
+               if (!sep)
+                       cmdputs(" ");
+               cmdtxt(np);
+               if (sep && np->narg.next)
+                       cmdputs(" ");
        }
-#endif
-       parsenextc = s;
-       parsenleft = len;
-       INTON;
 }
 
-void
-popstring(void)
+static void
+cmdtxt(union node *n)
 {
-       struct strpush *sp = parsefile->strpush;
+       union node *np;
+       struct nodelist *lp;
+       const char *p;
+       char s[2];
 
-       INTOFF;
-#ifdef CONFIG_ASH_ALIAS
-       if (sp->ap) {
-               if (parsenextc[-1] == ' ' || parsenextc[-1] == '\t') {
-                       checkkwd |= CHKALIAS;
+       if (!n)
+               return;
+       switch (n->type) {
+       default:
+#if DEBUG
+               abort();
+#endif
+       case NPIPE:
+               lp = n->npipe.cmdlist;
+               for (;;) {
+                       cmdtxt(lp->n);
+                       lp = lp->next;
+                       if (!lp)
+                               break;
+                       cmdputs(" | ");
                }
-               if (sp->string != sp->ap->val) {
-                       ckfree(sp->string);
+               break;
+       case NSEMI:
+               p = "; ";
+               goto binop;
+       case NAND:
+               p = " && ";
+               goto binop;
+       case NOR:
+               p = " || ";
+ binop:
+               cmdtxt(n->nbinary.ch1);
+               cmdputs(p);
+               n = n->nbinary.ch2;
+               goto donode;
+       case NREDIR:
+       case NBACKGND:
+               n = n->nredir.n;
+               goto donode;
+       case NNOT:
+               cmdputs("!");
+               n = n->nnot.com;
+ donode:
+               cmdtxt(n);
+               break;
+       case NIF:
+               cmdputs("if ");
+               cmdtxt(n->nif.test);
+               cmdputs("; then ");
+               n = n->nif.ifpart;
+               if (n->nif.elsepart) {
+                       cmdtxt(n);
+                       cmdputs("; else ");
+                       n = n->nif.elsepart;
                }
-               sp->ap->flag &= ~ALIASINUSE;
-               if (sp->ap->flag & ALIASDEAD) {
-                       unalias(sp->ap->name);
+               p = "; fi";
+               goto dotail;
+       case NSUBSHELL:
+               cmdputs("(");
+               n = n->nredir.n;
+               p = ")";
+               goto dotail;
+       case NWHILE:
+               p = "while ";
+               goto until;
+       case NUNTIL:
+               p = "until ";
+ until:
+               cmdputs(p);
+               cmdtxt(n->nbinary.ch1);
+               n = n->nbinary.ch2;
+               p = "; done";
+ dodo:
+               cmdputs("; do ");
+ dotail:
+               cmdtxt(n);
+               goto dotail2;
+       case NFOR:
+               cmdputs("for ");
+               cmdputs(n->nfor.var);
+               cmdputs(" in ");
+               cmdlist(n->nfor.args, 1);
+               n = n->nfor.body;
+               p = "; done";
+               goto dodo;
+       case NDEFUN:
+               cmdputs(n->narg.text);
+               p = "() { ... }";
+               goto dotail2;
+       case NCMD:
+               cmdlist(n->ncmd.args, 1);
+               cmdlist(n->ncmd.redirect, 0);
+               break;
+       case NARG:
+               p = n->narg.text;
+ dotail2:
+               cmdputs(p);
+               break;
+       case NHERE:
+       case NXHERE:
+               p = "<<...";
+               goto dotail2;
+       case NCASE:
+               cmdputs("case ");
+               cmdputs(n->ncase.expr->narg.text);
+               cmdputs(" in ");
+               for (np = n->ncase.cases; np; np = np->nclist.next) {
+                       cmdtxt(np->nclist.pattern);
+                       cmdputs(") ");
+                       cmdtxt(np->nclist.body);
+                       cmdputs(";; ");
+               }
+               p = "esac";
+               goto dotail2;
+       case NTO:
+               p = ">";
+               goto redir;
+       case NCLOBBER:
+               p = ">|";
+               goto redir;
+       case NAPPEND:
+               p = ">>";
+               goto redir;
+       case NTOFD:
+               p = ">&";
+               goto redir;
+       case NFROM:
+               p = "<";
+               goto redir;
+       case NFROMFD:
+               p = "<&";
+               goto redir;
+       case NFROMTO:
+               p = "<>";
+ redir:
+               s[0] = n->nfile.fd + '0';
+               s[1] = '\0';
+               cmdputs(s);
+               cmdputs(p);
+               if (n->type == NTOFD || n->type == NFROMFD) {
+                       s[0] = n->ndup.dupfd + '0';
+                       p = s;
+                       goto dotail2;
                }
+               n = n->nfile.fname;
+               goto donode;
        }
-#endif
-       parsenextc = sp->prevstring;
-       parsenleft = sp->prevnleft;
-/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
-       parsefile->strpush = sp->prev;
-       if (sp != &(parsefile->basestrpush))
-               ckfree(sp);
-       INTON;
 }
 
-/*
- * Set the input to take input from a file.  If push is set, push the
- * old input onto the stack first.
- */
-
-static int
-setinputfile(const char *fname, int flags)
+static char *
+commandtext(union node *n)
 {
-       int fd;
-       int fd2;
-
-       INTOFF;
-       if ((fd = open(fname, O_RDONLY)) < 0) {
-               if (flags & INPUT_NOFILE_OK)
-                       goto out;
-               sh_error("Can't open %s", fname);
-       }
-       if (fd < 10) {
-               fd2 = copyfd(fd, 10);
-               close(fd);
-               if (fd2 < 0)
-                       sh_error("Out of file descriptors");
-               fd = fd2;
-       }
-       setinputfd(fd, flags & INPUT_PUSH_FILE);
-out:
-       INTON;
-       return fd;
-}
-
-
-/*
- * Like setinputfile, but takes an open file descriptor.  Call this with
- * interrupts off.
- */
+       char *name;
 
-static void
-setinputfd(int fd, int push)
-{
-       (void) fcntl(fd, F_SETFD, FD_CLOEXEC);
-       if (push) {
-               pushfile();
-               parsefile->buf = 0;
-       }
-       parsefile->fd = fd;
-       if (parsefile->buf == NULL)
-               parsefile->buf = ckmalloc(IBUFSIZ);
-       parselleft = parsenleft = 0;
-       plinno = 1;
+       STARTSTACKSTR(cmdnextc);
+       cmdtxt(n);
+       name = stackblock();
+       TRACE(("commandtext: name %p, end %p\n\t\"%s\"\n",
+                       name, cmdnextc, cmdnextc));
+       return ckstrdup(name);
 }
-
+#endif /* JOBS */
 
 /*
- * Like setinputfile, but takes input from a string.
+ * Fork off a subshell.  If we are doing job control, give the subshell its
+ * own process group.  Jp is a job structure that the job is to be added to.
+ * N is the command that will be evaluated by the child.  Both jp and n may
+ * be NULL.  The mode parameter can be one of the following:
+ *      FORK_FG - Fork off a foreground process.
+ *      FORK_BG - Fork off a background process.
+ *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
+ *                   process group even if job control is on.
+ *
+ * When job control is turned off, background processes have their standard
+ * input redirected to /dev/null (except for the second and later processes
+ * in a pipeline).
+ *
+ * Called with interrupts off.
  */
-
-static void
-setinputstring(char *string)
-{
-       INTOFF;
-       pushfile();
-       parsenextc = string;
-       parsenleft = strlen(string);
-       parsefile->buf = NULL;
-       plinno = 1;
-       INTON;
-}
-
-
 /*
- * To handle the "." command, a stack of input files is used.  Pushfile
- * adds a new entry to the stack and popfile restores the previous level.
+ * Clear traps on a fork.
  */
-
-static void
-pushfile(void)
-{
-       struct parsefile *pf;
-
-       parsefile->nleft = parsenleft;
-       parsefile->lleft = parselleft;
-       parsefile->nextc = parsenextc;
-       parsefile->linno = plinno;
-       pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
-       pf->prev = parsefile;
-       pf->fd = -1;
-       pf->strpush = NULL;
-       pf->basestrpush.prev = NULL;
-       parsefile = pf;
-}
-
-
 static void
-popfile(void)
+clear_traps(void)
 {
-       struct parsefile *pf = parsefile;
-
-       INTOFF;
-       if (pf->fd >= 0)
-               close(pf->fd);
-       if (pf->buf)
-               ckfree(pf->buf);
-       while (pf->strpush)
-               popstring();
-       parsefile = pf->prev;
-       ckfree(pf);
-       parsenleft = parsefile->nleft;
-       parselleft = parsefile->lleft;
-       parsenextc = parsefile->nextc;
-       plinno = parsefile->linno;
-       INTON;
-}
-
-
-/*
- * Return to top level.
- */
+       char **tp;
 
-static void
-popallfiles(void)
-{
-       while (parsefile != &basepf)
-               popfile();
+       for (tp = trap; tp < &trap[NSIG]; tp++) {
+               if (*tp && **tp) {      /* trap not NULL or SIG_IGN */
+                       INT_OFF;
+                       free(*tp);
+                       *tp = NULL;
+                       if (tp != &trap[0])
+                               setsignal(tp - trap);
+                       INT_ON;
+               }
+       }
 }
 
+/* Lives far away from here, needed for forkchild */
+static void closescript(void);
 
-/*
- * Close the file(s) that the shell is reading commands from.  Called
- * after a fork is done.
- */
-
+/* Called after fork(), in child */
 static void
-closescript(void)
+forkchild(struct job *jp, union node *n, int mode)
 {
-       popallfiles();
-       if (parsefile->fd > 0) {
-               close(parsefile->fd);
-               parsefile->fd = 0;
-       }
-}
-
-/*      jobs.c    */
-
-/* mode flags for set_curjob */
-#define CUR_DELETE 2
-#define CUR_RUNNING 1
-#define CUR_STOPPED 0
-
-/* mode flags for dowait */
-#define DOWAIT_NORMAL 0
-#define DOWAIT_BLOCK 1
+       int oldlvl;
 
-/* array of jobs */
-static struct job *jobtab;
-/* size of array */
-static unsigned njobs;
-#if JOBS
-/* pgrp of shell on invocation */
-static int initialpgrp;
-static int ttyfd = -1;
-#endif
-/* current job */
-static struct job *curjob;
-/* number of presumed living untracked jobs */
-static int jobless;
+       TRACE(("Child shell %d\n", getpid()));
+       oldlvl = shlvl;
+       shlvl++;
 
-static void set_curjob(struct job *, unsigned);
+       closescript();
+       clear_traps();
 #if JOBS
-static int restartjob(struct job *, int);
-static void xtcsetpgrp(int, pid_t);
-static char *commandtext(union node *);
-static void cmdlist(union node *, int);
-static void cmdtxt(union node *);
-static void cmdputs(const char *);
-static void showpipe(struct job *, FILE *);
-#endif
-static int sprint_status(char *, int, int);
-static void freejob(struct job *);
-static struct job *getjob(const char *, int);
-static struct job *growjobtab(void);
-static void forkchild(struct job *, union node *, int);
-static void forkparent(struct job *, union node *, int, pid_t);
-static int dowait(int, struct job *);
-static int getstatus(struct job *);
-
-static void
-set_curjob(struct job *jp, unsigned mode)
-{
-       struct job *jp1;
-       struct job **jpp, **curp;
-
-       /* first remove from list */
-       jpp = curp = &curjob;
-       do {
-               jp1 = *jpp;
-               if (jp1 == jp)
-                       break;
-               jpp = &jp1->prev_job;
-       } while (1);
-       *jpp = jp1->prev_job;
+       /* do job control only in root shell */
+       jobctl = 0;
+       if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
+               pid_t pgrp;
 
-       /* Then re-insert in correct position */
-       jpp = curp;
-       switch (mode) {
-       default:
-#if DEBUG
-               abort();
+               if (jp->nprocs == 0)
+                       pgrp = getpid();
+               else
+                       pgrp = jp->ps[0].pid;
+               /* This can fail because we are doing it in the parent also */
+               (void)setpgid(0, pgrp);
+               if (mode == FORK_FG)
+                       xtcsetpgrp(ttyfd, pgrp);
+               setsignal(SIGTSTP);
+               setsignal(SIGTTOU);
+       } else
 #endif
-       case CUR_DELETE:
-               /* job being deleted */
-               break;
-       case CUR_RUNNING:
-               /* newly created job or backgrounded job,
-                  put after all stopped jobs. */
-               do {
-                       jp1 = *jpp;
+       if (mode == FORK_BG) {
+               ignoresig(SIGINT);
+               ignoresig(SIGQUIT);
+               if (jp->nprocs == 0) {
+                       close(0);
+                       if (open(bb_dev_null, O_RDONLY) != 0)
+                               ash_msg_and_raise_error("can't open %s", bb_dev_null);
+               }
+       }
+       if (!oldlvl && iflag) {
+               setsignal(SIGINT);
+               setsignal(SIGQUIT);
+               setsignal(SIGTERM);
+       }
+       for (jp = curjob; jp; jp = jp->prev_job)
+               freejob(jp);
+       jobless = 0;
+}
+
+/* Called after fork(), in parent */
+static void
+forkparent(struct job *jp, union node *n, int mode, pid_t pid)
+{
+       TRACE(("In parent shell: child = %d\n", pid));
+       if (!jp) {
+               while (jobless && dowait(DOWAIT_NORMAL, 0) > 0);
+               jobless++;
+               return;
+       }
 #if JOBS
-                       if (!jp1 || jp1->state != JOBSTOPPED)
+       if (mode != FORK_NOJOB && jp->jobctl) {
+               int pgrp;
+
+               if (jp->nprocs == 0)
+                       pgrp = pid;
+               else
+                       pgrp = jp->ps[0].pid;
+               /* This can fail because we are doing it in the child also */
+               setpgid(pid, pgrp);
+       }
 #endif
-                               break;
-                       jpp = &jp1->prev_job;
-               } while (1);
-               /* FALLTHROUGH */
+       if (mode == FORK_BG) {
+               backgndpid = pid;               /* set $! */
+               set_curjob(jp, CUR_RUNNING);
+       }
+       if (jp) {
+               struct procstat *ps = &jp->ps[jp->nprocs++];
+               ps->pid = pid;
+               ps->status = -1;
+               ps->cmd = nullstr;
 #if JOBS
-       case CUR_STOPPED:
+               if (jobctl && n)
+                       ps->cmd = commandtext(n);
 #endif
-               /* newly stopped job - becomes curjob */
-               jp->prev_job = *jpp;
-               *jpp = jp;
-               break;
        }
 }
 
-#if JOBS
+static int
+forkshell(struct job *jp, union node *n, int mode)
+{
+       int pid;
+
+       TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode));
+       pid = fork();
+       if (pid < 0) {
+               TRACE(("Fork failed, errno=%d", errno));
+               if (jp)
+                       freejob(jp);
+               ash_msg_and_raise_error("cannot fork");
+       }
+       if (pid == 0)
+               forkchild(jp, n, mode);
+       else
+               forkparent(jp, n, mode, pid);
+       return pid;
+}
+
 /*
- * Turn job control on and off.
+ * Wait for job to finish.
  *
- * Note:  This code assumes that the third arg to ioctl is a character
- * pointer, which is true on Berkeley systems but not System V.  Since
- * System V doesn't have job control yet, this isn't a problem now.
+ * Under job control we have the problem that while a child process is
+ * running interrupts generated by the user are sent to the child but not
+ * to the shell.  This means that an infinite loop started by an inter-
+ * active user may be hard to kill.  With job control turned off, an
+ * interactive user may place an interactive program inside a loop.  If
+ * the interactive program catches interrupts, the user doesn't want
+ * these interrupts to also abort the loop.  The approach we take here
+ * is to have the shell ignore interrupt signals while waiting for a
+ * foreground process to terminate, and then send itself an interrupt
+ * signal if the child process was terminated by an interrupt signal.
+ * Unfortunately, some programs want to do a bit of cleanup and then
+ * exit on interrupt; unless these processes terminate themselves by
+ * sending a signal to themselves (instead of calling exit) they will
+ * confuse this approach.
  *
  * Called with interrupts off.
  */
-
-void
-setjobctl(int on)
+static int
+waitforjob(struct job *jp)
 {
-       int fd;
-       int pgrp;
-
-       if (on == jobctl || rootshell == 0)
-               return;
-       if (on) {
-               int ofd;
-               ofd = fd = open(_PATH_TTY, O_RDWR);
-               if (fd < 0) {
-                       fd += 3;
-                       while (!isatty(fd) && --fd >= 0)
-                               ;
-               }
-               fd = fcntl(fd, F_DUPFD, 10);
-               close(ofd);
-               if (fd < 0)
-                       goto out;
-               fcntl(fd, F_SETFD, FD_CLOEXEC);
-               do { /* while we are in the background */
-                       if ((pgrp = tcgetpgrp(fd)) < 0) {
-out:
-                               sh_warnx("can't access tty; job control turned off");
-                               mflag = on = 0;
-                               goto close;
-                       }
-                       if (pgrp == getpgrp())
-                               break;
-                       killpg(0, SIGTTIN);
-               } while (1);
-               initialpgrp = pgrp;
+       int st;
 
-               setsignal(SIGTSTP);
-               setsignal(SIGTTOU);
-               setsignal(SIGTTIN);
-               pgrp = rootpid;
-               setpgid(0, pgrp);
-               xtcsetpgrp(fd, pgrp);
-       } else {
-               /* turning job control off */
-               fd = ttyfd;
-               pgrp = initialpgrp;
-               xtcsetpgrp(fd, pgrp);
-               setpgid(0, pgrp);
-               setsignal(SIGTSTP);
-               setsignal(SIGTTOU);
-               setsignal(SIGTTIN);
-close:
-               close(fd);
-               fd = -1;
+       TRACE(("waitforjob(%%%d) called\n", jobno(jp)));
+       while (jp->state == JOBRUNNING) {
+               dowait(DOWAIT_BLOCK, jp);
        }
-       ttyfd = fd;
-       jobctl = on;
+       st = getstatus(jp);
+#if JOBS
+       if (jp->jobctl) {
+               xtcsetpgrp(ttyfd, rootpid);
+               /*
+                * This is truly gross.
+                * If we're doing job control, then we did a TIOCSPGRP which
+                * caused us (the shell) to no longer be in the controlling
+                * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
+                * intuit from the subprocess exit status whether a SIGINT
+                * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
+                */
+               if (jp->sigint)
+                       raise(SIGINT);
+       }
+       if (jp->state == JOBDONE)
+#endif
+               freejob(jp);
+       return st;
 }
 
+/*
+ * return 1 if there are stopped jobs, otherwise 0
+ */
 static int
-killcmd(int argc, char **argv)
+stoppedjobs(void)
 {
-       int signo = -1;
-       int list = 0;
-       int i;
-       pid_t pid;
        struct job *jp;
+       int retval;
 
-       if (argc <= 1) {
-usage:
-               sh_error(
-"Usage: kill [-s sigspec | -signum | -sigspec] [pid | job]... or\n"
-"kill -l [exitstatus]"
-               );
+       retval = 0;
+       if (job_warning)
+               goto out;
+       jp = curjob;
+       if (jp && jp->state == JOBSTOPPED) {
+               out2str("You have stopped jobs.\n");
+               job_warning = 2;
+               retval++;
        }
+ out:
+       return retval;
+}
 
-       if (**++argv == '-') {
-               signo = get_signum(*argv + 1);
-               if (signo < 0) {
-                       int c;
 
-                       while ((c = nextopt("ls:")) != '\0')
-                               switch (c) {
-                               default:
-#if DEBUG
-                                       abort();
+/* ============ redir.c
+ *
+ * Code for dealing with input/output redirection.
+ */
+
+#define EMPTY -2                /* marks an unused slot in redirtab */
+#ifndef PIPE_BUF
+# define PIPESIZE 4096          /* amount of buffering in a pipe */
+#else
+# define PIPESIZE PIPE_BUF
 #endif
-                               case 'l':
-                                       list = 1;
-                                       break;
-                               case 's':
-                                       signo = get_signum(optionarg);
-                                       if (signo < 0) {
-                                               sh_error(
-                                                       "invalid signal number or name: %s",
-                                                       optionarg
-                                               );
-                                       }
-                                       break;
-                               }
-                       argv = argptr;
-               } else
-                       argv++;
-       }
 
-       if (!list && signo < 0)
-               signo = SIGTERM;
+/*
+ * Open a file in noclobber mode.
+ * The code was copied from bash.
+ */
+static int
+noclobberopen(const char *fname)
+{
+       int r, fd;
+       struct stat finfo, finfo2;
 
-       if ((signo < 0 || !*argv) ^ list) {
-               goto usage;
+       /*
+        * If the file exists and is a regular file, return an error
+        * immediately.
+        */
+       r = stat(fname, &finfo);
+       if (r == 0 && S_ISREG(finfo.st_mode)) {
+               errno = EEXIST;
+               return -1;
        }
 
-       if (list) {
-               const char *name;
-
-               if (!*argv) {
-                       for (i = 1; i < NSIG; i++) {
-                               name = get_signame(i);
-                               if (isdigit(*name))
-                                       out1fmt(snlfmt, name);
-                       }
-                       return 0;
-               }
-               name = get_signame(signo);
-               if (isdigit(*name))
-                       out1fmt(snlfmt, name);
-               else
-                       sh_error("invalid signal number or exit status: %s", *argptr);
-               return 0;
-       }
+       /*
+        * If the file was not present (r != 0), make sure we open it
+        * exclusively so that if it is created before we open it, our open
+        * will fail.  Make sure that we do not truncate an existing file.
+        * Note that we don't turn on O_EXCL unless the stat failed -- if the
+        * file was not a regular file, we leave O_EXCL off.
+        */
+       if (r != 0)
+               return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
+       fd = open(fname, O_WRONLY|O_CREAT, 0666);
 
-       i = 0;
-       do {
-               if (**argv == '%') {
-                       jp = getjob(*argv, 0);
-                       pid = -jp->ps[0].pid;
-               } else {
-                       pid = **argv == '-' ?
-                               -number(*argv + 1) : number(*argv);
-               }
-               if (kill(pid, signo) != 0) {
-                       sh_warnx("(%d) - %m", pid);
-                       i = 1;
-               }
-       } while (*++argv);
+       /* If the open failed, return the file descriptor right away. */
+       if (fd < 0)
+               return fd;
 
-       return i;
-}
-#endif /* JOBS */
+       /*
+        * OK, the open succeeded, but the file may have been changed from a
+        * non-regular file to a regular file between the stat and the open.
+        * We are assuming that the O_EXCL open handles the case where FILENAME
+        * did not exist and is symlinked to an existing file between the stat
+        * and open.
+        */
 
-#if defined(JOBS) || DEBUG
-static int
-jobno(const struct job *jp)
-{
-       return jp - jobtab + 1;
+       /*
+        * If we can open it and fstat the file descriptor, and neither check
+        * revealed that it was a regular file, and the file has not been
+        * replaced, return the file descriptor.
+        */
+       if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode)
+        && finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
+               return fd;
+
+       /* The file has been replaced.  badness. */
+       close(fd);
+       errno = EEXIST;
+       return -1;
 }
-#endif
 
-#if JOBS
+/*
+ * Handle here documents.  Normally we fork off a process to write the
+ * data to a pipe.  If the document is short, we can stuff the data in
+ * the pipe without forking.
+ */
+/* openhere needs this forward reference */
+static void expandhere(union node *arg, int fd);
 static int
-fgcmd(int argc, char **argv)
+openhere(union node *redir)
 {
-       struct job *jp;
-       FILE *out;
-       int mode;
-       int retval;
+       int pip[2];
+       size_t len = 0;
 
-       mode = (**argv == 'f') ? FORK_FG : FORK_BG;
-       nextopt(nullstr);
-       argv = argptr;
-       out = stdout;
-       do {
-               jp = getjob(*argv, 1);
-               if (mode == FORK_BG) {
-                       set_curjob(jp, CUR_RUNNING);
-                       fprintf(out, "[%d] ", jobno(jp));
+       if (pipe(pip) < 0)
+               ash_msg_and_raise_error("pipe call failed");
+       if (redir->type == NHERE) {
+               len = strlen(redir->nhere.doc->narg.text);
+               if (len <= PIPESIZE) {
+                       full_write(pip[1], redir->nhere.doc->narg.text, len);
+                       goto out;
                }
-               outstr(jp->ps->cmd, out);
-               showpipe(jp, out);
-               retval = restartjob(jp, mode);
-       } while (*argv && *++argv);
-       return retval;
+       }
+       if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
+               close(pip[0]);
+               signal(SIGINT, SIG_IGN);
+               signal(SIGQUIT, SIG_IGN);
+               signal(SIGHUP, SIG_IGN);
+#ifdef SIGTSTP
+               signal(SIGTSTP, SIG_IGN);
+#endif
+               signal(SIGPIPE, SIG_DFL);
+               if (redir->type == NHERE)
+                       full_write(pip[1], redir->nhere.doc->narg.text, len);
+               else
+                       expandhere(redir->nhere.doc, pip[1]);
+               _exit(0);
+       }
+ out:
+       close(pip[1]);
+       return pip[0];
 }
 
-static int bgcmd(int, char **) __attribute__((__alias__("fgcmd")));
-
-
 static int
-restartjob(struct job *jp, int mode)
+openredirect(union node *redir)
 {
-       struct procstat *ps;
-       int i;
-       int status;
-       pid_t pgid;
+       char *fname;
+       int f;
 
-       INTOFF;
-       if (jp->state == JOBDONE)
-               goto out;
-       jp->state = JOBRUNNING;
-       pgid = jp->ps->pid;
-       if (mode == FORK_FG)
-               xtcsetpgrp(ttyfd, pgid);
-       killpg(pgid, SIGCONT);
-       ps = jp->ps;
-       i = jp->nprocs;
-       do {
-               if (WIFSTOPPED(ps->status)) {
-                       ps->status = -1;
+       switch (redir->nfile.type) {
+       case NFROM:
+               fname = redir->nfile.expfname;
+               f = open(fname, O_RDONLY);
+               if (f < 0)
+                       goto eopen;
+               break;
+       case NFROMTO:
+               fname = redir->nfile.expfname;
+               f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666);
+               if (f < 0)
+                       goto ecreate;
+               break;
+       case NTO:
+               /* Take care of noclobber mode. */
+               if (Cflag) {
+                       fname = redir->nfile.expfname;
+                       f = noclobberopen(fname);
+                       if (f < 0)
+                               goto ecreate;
+                       break;
                }
-       } while (ps++, --i);
-out:
-       status = (mode == FORK_FG) ? waitforjob(jp) : 0;
-       INTON;
-       return status;
-}
+               /* FALLTHROUGH */
+       case NCLOBBER:
+               fname = redir->nfile.expfname;
+               f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666);
+               if (f < 0)
+                       goto ecreate;
+               break;
+       case NAPPEND:
+               fname = redir->nfile.expfname;
+               f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666);
+               if (f < 0)
+                       goto ecreate;
+               break;
+       default:
+#if DEBUG
+               abort();
 #endif
+               /* Fall through to eliminate warning. */
+       case NTOFD:
+       case NFROMFD:
+               f = -1;
+               break;
+       case NHERE:
+       case NXHERE:
+               f = openhere(redir);
+               break;
+       }
+
+       return f;
+ ecreate:
+       ash_msg_and_raise_error("cannot create %s: %s", fname, errmsg(errno, "nonexistent directory"));
+ eopen:
+       ash_msg_and_raise_error("cannot open %s: %s", fname, errmsg(errno, "no such file"));
+}
 
+/*
+ * Copy a file descriptor to be >= to.  Returns -1
+ * if the source file descriptor is closed, EMPTY if there are no unused
+ * file descriptors left.
+ */
 static int
-sprint_status(char *s, int status, int sigonly)
+copyfd(int from, int to)
 {
-       int col;
-       int st;
+       int newfd;
 
-       col = 0;
-       if (!WIFEXITED(status)) {
-#if JOBS
-               if (WIFSTOPPED(status))
-                       st = WSTOPSIG(status);
-               else
-#endif
-                       st = WTERMSIG(status);
-               if (sigonly) {
-                       if (st == SIGINT || st == SIGPIPE)
-                               goto out;
-#if JOBS
-                       if (WIFSTOPPED(status))
-                               goto out;
-#endif
-               }
-               st &= 0x7f;
-               col = fmtstr(s, 32, strsignal(st));
-               if (WCOREDUMP(status)) {
-                       col += fmtstr(s + col, 16, " (core dumped)");
-               }
-       } else if (!sigonly) {
-               st = WEXITSTATUS(status);
-               if (st)
-                       col = fmtstr(s, 16, "Done(%d)", st);
-               else
-                       col = fmtstr(s, 16, "Done");
+       newfd = fcntl(from, F_DUPFD, to);
+       if (newfd < 0) {
+               if (errno == EMFILE)
+                       return EMPTY;
+               ash_msg_and_raise_error("%d: %m", from);
        }
-
-out:
-       return col;
+       return newfd;
 }
 
-#if JOBS
 static void
-showjob(FILE *out, struct job *jp, int mode)
+dupredirect(union node *redir, int f)
 {
-       struct procstat *ps;
-       struct procstat *psend;
-       int col;
-       int indent;
-       char s[80];
-
-       ps = jp->ps;
+       int fd = redir->nfile.fd;
 
-       if (mode & SHOW_PGID) {
-               /* just output process (group) id of pipeline */
-               fprintf(out, "%d\n", ps->pid);
+       if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
+               if (redir->ndup.dupfd >= 0) {   /* if not ">&-" */
+                       copyfd(redir->ndup.dupfd, fd);
+               }
                return;
        }
 
-       col = fmtstr(s, 16, "[%d]   ", jobno(jp));
-       indent = col;
-
-       if (jp == curjob)
-               s[col - 2] = '+';
-       else if (curjob && jp == curjob->prev_job)
-               s[col - 2] = '-';
-
-       if (mode & SHOW_PID)
-               col += fmtstr(s + col, 16, "%d ", ps->pid);
-
-       psend = ps + jp->nprocs;
-
-       if (jp->state == JOBRUNNING) {
-               scopy("Running", s + col);
-               col += strlen("Running");
-       } else {
-               int status = psend[-1].status;
-#if JOBS
-               if (jp->state == JOBSTOPPED)
-                       status = jp->stopstatus;
-#endif
-               col += sprint_status(s + col, status, 0);
+       if (f != fd) {
+               copyfd(f, fd);
+               close(f);
        }
+}
 
-       goto start;
-
-       do {
-               /* for each process */
-               col = fmtstr(s, 48, " |\n%*c%d ", indent, ' ', ps->pid) - 3;
-
-start:
-               fprintf(out, "%s%*c%s",
-                       s, 33 - col >= 0 ? 33 - col : 0, ' ', ps->cmd
-               );
-               if (!(mode & SHOW_PID)) {
-                       showpipe(jp, out);
-                       break;
-               }
-               if (++ps == psend) {
-                       outcslow('\n', out);
-                       break;
-               }
-       } while (1);
-
-       jp->changed = 0;
-
-       if (jp->state == JOBDONE) {
-               TRACE(("showjob: freeing job %d\n", jobno(jp)));
-               freejob(jp);
+/*
+ * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
+ * old file descriptors are stashed away so that the redirection can be
+ * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
+ * standard output, and the standard error if it becomes a duplicate of
+ * stdout, is saved in memory.
+ */
+/* flags passed to redirect */
+#define REDIR_PUSH    01        /* save previous values of file descriptors */
+#define REDIR_SAVEFD2 03        /* set preverrout */
+static void
+redirect(union node *redir, int flags)
+{
+       union node *n;
+       struct redirtab *sv;
+       int i;
+       int fd;
+       int newfd;
+       int *p;
+       nullredirs++;
+       if (!redir) {
+               return;
+       }
+       sv = NULL;
+       INT_OFF;
+       if (flags & REDIR_PUSH) {
+               struct redirtab *q;
+               q = ckmalloc(sizeof(struct redirtab));
+               q->next = redirlist;
+               redirlist = q;
+               q->nullredirs = nullredirs - 1;
+               for (i = 0; i < 10; i++)
+                       q->renamed[i] = EMPTY;
+               nullredirs = 0;
+               sv = q;
        }
-}
-
-
-static int
-jobscmd(int argc, char **argv)
-{
-       int mode, m;
-       FILE *out;
-
-       mode = 0;
-       while ((m = nextopt("lp")))
-               if (m == 'l')
-                       mode = SHOW_PID;
-               else
-                       mode = SHOW_PGID;
+       n = redir;
+       do {
+               fd = n->nfile.fd;
+               if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD)
+                && n->ndup.dupfd == fd)
+                       continue; /* redirect from/to same file descriptor */
 
-       out = stdout;
-       argv = argptr;
-       if (*argv)
-               do
-                       showjob(out, getjob(*argv,0), mode);
-               while (*++argv);
-       else
-               showjobs(out, mode);
+               newfd = openredirect(n);
+               if (fd == newfd)
+                       continue;
+               if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
+                       i = fcntl(fd, F_DUPFD, 10);
 
-       return 0;
+                       if (i == -1) {
+                               i = errno;
+                               if (i != EBADF) {
+                                       close(newfd);
+                                       errno = i;
+                                       ash_msg_and_raise_error("%d: %m", fd);
+                                       /* NOTREACHED */
+                               }
+                       } else {
+                               *p = i;
+                               close(fd);
+                       }
+               } else {
+                       close(fd);
+               }
+               dupredirect(n, newfd);
+       } while ((n = n->nfile.next));
+       INT_ON;
+       if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
+               preverrout_fd = sv->renamed[2];
 }
 
-
 /*
- * Print a list of jobs.  If "change" is nonzero, only print jobs whose
- * statuses have changed since the last call to showjobs.
+ * Undo the effects of the last redirection.
  */
-
 static void
-showjobs(FILE *out, int mode)
+popredir(int drop)
 {
-       struct job *jp;
-
-       TRACE(("showjobs(%x) called\n", mode));
-
-       /* If not even one one job changed, there is nothing to do */
-       while (dowait(DOWAIT_NORMAL, NULL) > 0)
-               continue;
+       struct redirtab *rp;
+       int i;
 
-       for (jp = curjob; jp; jp = jp->prev_job) {
-               if (!(mode & SHOW_CHANGED) || jp->changed)
-                       showjob(out, jp, mode);
+       if (--nullredirs >= 0)
+               return;
+       INT_OFF;
+       rp = redirlist;
+       for (i = 0; i < 10; i++) {
+               if (rp->renamed[i] != EMPTY) {
+                       if (!drop) {
+                               close(i);
+                               copyfd(rp->renamed[i], i);
+                       }
+                       close(rp->renamed[i]);
+               }
        }
+       redirlist = rp->next;
+       nullredirs = rp->nullredirs;
+       free(rp);
+       INT_ON;
 }
-#endif /* JOBS */
 
 /*
- * Mark a job structure as unused.
+ * Undo all redirections.  Called on error or interrupt.
  */
 
+/*
+ * Discard all saved file descriptors.
+ */
 static void
-freejob(struct job *jp)
+clearredir(int drop)
 {
-       struct procstat *ps;
-       int i;
-
-       INTOFF;
-       for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
-               if (ps->cmd != nullstr)
-                       ckfree(ps->cmd);
+       for (;;) {
+               nullredirs = 0;
+               if (!redirlist)
+                       break;
+               popredir(drop);
        }
-       if (jp->ps != &jp->ps0)
-               ckfree(jp->ps);
-       jp->used = 0;
-       set_curjob(jp, CUR_DELETE);
-       INTON;
 }
 
-
 static int
-waitcmd(int argc, char **argv)
+redirectsafe(union node *redir, int flags)
 {
-       struct job *job;
-       int retval;
-       struct job *jp;
-
-       EXSIGON();
-
-       nextopt(nullstr);
-       retval = 0;
+       int err;
+       volatile int saveint;
+       struct jmploc *volatile savehandler = exception_handler;
+       struct jmploc jmploc;
 
-       argv = argptr;
-       if (!*argv) {
-               /* wait for all jobs */
-               for (;;) {
-                       jp = curjob;
-                       while (1) {
-                               if (!jp) {
-                                       /* no running procs */
-                                       goto out;
-                               }
-                               if (jp->state == JOBRUNNING)
-                                       break;
-                               jp->waited = 1;
-                               jp = jp->prev_job;
-                       }
-                       dowait(DOWAIT_BLOCK, 0);
-               }
+       SAVE_INT(saveint);
+       err = setjmp(jmploc.loc) * 2;
+       if (!err) {
+               exception_handler = &jmploc;
+               redirect(redir, flags);
        }
-
-       retval = 127;
-       do {
-               if (**argv != '%') {
-                       pid_t pid = number(*argv);
-                       job = curjob;
-                       goto start;
-                       do {
-                               if (job->ps[job->nprocs - 1].pid == pid)
-                                       break;
-                               job = job->prev_job;
-start:
-                               if (!job)
-                                       goto repeat;
-                       } while (1);
-               } else
-                       job = getjob(*argv, 0);
-               /* loop until process terminated or stopped */
-               while (job->state == JOBRUNNING)
-                       dowait(DOWAIT_BLOCK, 0);
-               job->waited = 1;
-               retval = getstatus(job);
-repeat:
-               ;
-       } while (*++argv);
-
-out:
-       return retval;
+       exception_handler = savehandler;
+       if (err && exception != EXERROR)
+               longjmp(exception_handler->loc, 1);
+       RESTORE_INT(saveint);
+       return err;
 }
 
 
-/*
- * Convert a job name to a job structure.
+/* ============ Routines to expand arguments to commands
+ *
+ * We have to deal with backquotes, shell variables, and file metacharacters.
  */
 
-static struct job *
-getjob(const char *name, int getctl)
-{
-       struct job *jp;
-       struct job *found;
-       const char *err_msg = "No such job: %s";
-       unsigned num;
-       int c;
-       const char *p;
-       char *(*match)(const char *, const char *);
-
-       jp = curjob;
-       p = name;
-       if (!p)
-               goto currentjob;
-
-       if (*p != '%')
-               goto err;
-
-       c = *++p;
-       if (!c)
-               goto currentjob;
-
-       if (!p[1]) {
-               if (c == '+' || c == '%') {
-currentjob:
-                       err_msg = "No current job";
-                       goto check;
-               } else if (c == '-') {
-                       if (jp)
-                               jp = jp->prev_job;
-                       err_msg = "No previous job";
-check:
-                       if (!jp)
-                               goto err;
-                       goto gotit;
-               }
-       }
+/*
+ * expandarg flags
+ */
+#define EXP_FULL        0x1     /* perform word splitting & file globbing */
+#define EXP_TILDE       0x2     /* do normal tilde expansion */
+#define EXP_VARTILDE    0x4     /* expand tildes in an assignment */
+#define EXP_REDIR       0x8     /* file glob for a redirection (1 match only) */
+#define EXP_CASE        0x10    /* keeps quotes around for CASE pattern */
+#define EXP_RECORD      0x20    /* need to record arguments for ifs breakup */
+#define EXP_VARTILDE2   0x40    /* expand tildes after colons only */
+#define EXP_WORD        0x80    /* expand word in parameter expansion */
+#define EXP_QWORD       0x100   /* expand word in quoted parameter expansion */
+/*
+ * _rmescape() flags
+ */
+#define RMESCAPE_ALLOC  0x1     /* Allocate a new string */
+#define RMESCAPE_GLOB   0x2     /* Add backslashes for glob */
+#define RMESCAPE_QUOTED 0x4     /* Remove CTLESC unless in quotes */
+#define RMESCAPE_GROW   0x8     /* Grow strings instead of stalloc */
+#define RMESCAPE_HEAP   0x10    /* Malloc strings instead of stalloc */
 
-       if (is_number(p)) {
-               num = atoi(p);
-               if (num < njobs) {
-                       jp = jobtab + num - 1;
-                       if (jp->used)
-                               goto gotit;
-                       goto err;
-               }
-       }
+/*
+ * Structure specifying which parts of the string should be searched
+ * for IFS characters.
+ */
+struct ifsregion {
+       struct ifsregion *next; /* next region in list */
+       int begoff;             /* offset of start of region */
+       int endoff;             /* offset of end of region */
+       int nulonly;            /* search for nul bytes only */
+};
 
-       match = prefix;
-       if (*p == '?') {
-               match = strstr;
-               p++;
-       }
+struct arglist {
+       struct strlist *list;
+       struct strlist **lastp;
+};
 
-       found = 0;
-       while (1) {
-               if (!jp)
-                       goto err;
-               if (match(jp->ps[0].cmd, p)) {
-                       if (found)
-                               goto err;
-                       found = jp;
-                       err_msg = "%s: ambiguous";
-               }
-               jp = jp->prev_job;
-       }
+/* output of current string */
+static char *expdest;
+/* list of back quote expressions */
+static struct nodelist *argbackq;
+/* first struct in list of ifs regions */
+static struct ifsregion ifsfirst;
+/* last struct in list */
+static struct ifsregion *ifslastp;
+/* holds expanded arg list */
+static struct arglist exparg;
 
-gotit:
-#if JOBS
-       err_msg = "job %s not created under job control";
-       if (getctl && jp->jobctl == 0)
-               goto err;
+/*
+ * Our own itoa().
+ */
+static int
+cvtnum(arith_t num)
+{
+       int len;
+
+       expdest = makestrspace(32, expdest);
+#if ENABLE_ASH_MATH_SUPPORT_64
+       len = fmtstr(expdest, 32, "%lld", (long long) num);
+#else
+       len = fmtstr(expdest, 32, "%ld", num);
 #endif
-       return jp;
-err:
-       sh_error(err_msg, name);
+       STADJUST(len, expdest);
+       return len;
 }
 
+static size_t
+esclen(const char *start, const char *p)
+{
+       size_t esc = 0;
+
+       while (p > start && *--p == CTLESC) {
+               esc++;
+       }
+       return esc;
+}
 
 /*
- * Return a new job structure.
- * Called with interrupts off.
+ * Remove any CTLESC characters from a string.
  */
-
-static struct job *
-makejob(union node *node, int nprocs)
+static char *
+_rmescapes(char *str, int flag)
 {
-       int i;
-       struct job *jp;
+       static const char qchars[] ALIGN1 = { CTLESC, CTLQUOTEMARK, '\0' };
 
-       for (i = njobs, jp = jobtab ; ; jp++) {
-               if (--i < 0) {
-                       jp = growjobtab();
-                       break;
+       char *p, *q, *r;
+       unsigned inquotes;
+       int notescaped;
+       int globbing;
+
+       p = strpbrk(str, qchars);
+       if (!p) {
+               return str;
+       }
+       q = p;
+       r = str;
+       if (flag & RMESCAPE_ALLOC) {
+               size_t len = p - str;
+               size_t fulllen = len + strlen(p) + 1;
+
+               if (flag & RMESCAPE_GROW) {
+                       r = makestrspace(fulllen, expdest);
+               } else if (flag & RMESCAPE_HEAP) {
+                       r = ckmalloc(fulllen);
+               } else {
+                       r = stalloc(fulllen);
                }
-               if (jp->used == 0)
-                       break;
-               if (jp->state != JOBDONE || !jp->waited)
-                       continue;
-#if JOBS
-               if (jobctl)
+               q = r;
+               if (len > 0) {
+                       q = memcpy(q, str, len) + len;
+               }
+       }
+       inquotes = (flag & RMESCAPE_QUOTED) ^ RMESCAPE_QUOTED;
+       globbing = flag & RMESCAPE_GLOB;
+       notescaped = globbing;
+       while (*p) {
+               if (*p == CTLQUOTEMARK) {
+                       inquotes = ~inquotes;
+                       p++;
+                       notescaped = globbing;
                        continue;
-#endif
-               freejob(jp);
-               break;
+               }
+               if (*p == '\\') {
+                       /* naked back slash */
+                       notescaped = 0;
+                       goto copy;
+               }
+               if (*p == CTLESC) {
+                       p++;
+                       if (notescaped && inquotes && *p != '/') {
+                               *q++ = '\\';
+                       }
+               }
+               notescaped = globbing;
+ copy:
+               *q++ = *p++;
        }
-       memset(jp, 0, sizeof(*jp));
-#if JOBS
-       if (jobctl)
-               jp->jobctl = 1;
-#endif
-       jp->prev_job = curjob;
-       curjob = jp;
-       jp->used = 1;
-       jp->ps = &jp->ps0;
-       if (nprocs > 1) {
-               jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
+       *q = '\0';
+       if (flag & RMESCAPE_GROW) {
+               expdest = r;
+               STADJUST(q - r + 1, expdest);
        }
-       TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs,
-           jobno(jp)));
-       return jp;
+       return r;
 }
+#define rmescapes(p) _rmescapes((p), 0)
 
-static struct job *
-growjobtab(void)
+#define pmatch(a, b) !fnmatch((a), (b), 0)
+
+/*
+ * Prepare a pattern for a expmeta (internal glob(3)) call.
+ *
+ * Returns an stalloced string.
+ */
+static char *
+preglob(const char *pattern, int quoted, int flag)
 {
-       size_t len;
-       ptrdiff_t offset;
-       struct job *jp, *jq;
+       flag |= RMESCAPE_GLOB;
+       if (quoted) {
+               flag |= RMESCAPE_QUOTED;
+       }
+       return _rmescapes((char *)pattern, flag);
+}
 
-       len = njobs * sizeof(*jp);
-       jq = jobtab;
-       jp = ckrealloc(jq, len + 4 * sizeof(*jp));
+/*
+ * Put a string on the stack.
+ */
+static void
+memtodest(const char *p, size_t len, int syntax, int quotes)
+{
+       char *q = expdest;
 
-       offset = (char *)jp - (char *)jq;
-       if (offset) {
-               /* Relocate pointers */
-               size_t l = len;
+       q = makestrspace(len * 2, q);
 
-               jq = (struct job *)((char *)jq + l);
-               while (l) {
-                       l -= sizeof(*jp);
-                       jq--;
-#define joff(p) ((struct job *)((char *)(p) + l))
-#define jmove(p) (p) = (void *)((char *)(p) + offset)
-                       if (xlikely(joff(jp)->ps == &jq->ps0))
-                               jmove(joff(jp)->ps);
-                       if (joff(jp)->prev_job)
-                               jmove(joff(jp)->prev_job);
-               }
-               if (curjob)
-                       jmove(curjob);
-#undef joff
-#undef jmove
+       while (len--) {
+               int c = signed_char2int(*p++);
+               if (!c)
+                       continue;
+               if (quotes && (SIT(c, syntax) == CCTL || SIT(c, syntax) == CBACK))
+                       USTPUTC(CTLESC, q);
+               USTPUTC(c, q);
        }
 
-       njobs += 4;
-       jobtab = jp;
-       jp = (struct job *)((char *)jp + len);
-       jq = jp + 3;
-       do {
-               jq->used = 0;
-       } while (--jq >= jp);
-       return jp;
+       expdest = q;
 }
 
+static void
+strtodest(const char *p, int syntax, int quotes)
+{
+       memtodest(p, strlen(p), syntax, quotes);
+}
 
 /*
- * Fork off a subshell.  If we are doing job control, give the subshell its
- * own process group.  Jp is a job structure that the job is to be added to.
- * N is the command that will be evaluated by the child.  Both jp and n may
- * be NULL.  The mode parameter can be one of the following:
- *      FORK_FG - Fork off a foreground process.
- *      FORK_BG - Fork off a background process.
- *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
- *                   process group even if job control is on.
- *
- * When job control is turned off, background processes have their standard
- * input redirected to /dev/null (except for the second and later processes
- * in a pipeline).
- *
- * Called with interrupts off.
+ * Record the fact that we have to scan this region of the
+ * string for IFS characters.
  */
-
-static void forkchild(struct job *jp, union node *n, int mode)
+static void
+recordregion(int start, int end, int nulonly)
 {
-       int oldlvl;
-
-       TRACE(("Child shell %d\n", getpid()));
-       oldlvl = shlvl;
-       shlvl++;
-
-       closescript();
-       clear_traps();
-#if JOBS
-       /* do job control only in root shell */
-       jobctl = 0;
-       if (mode != FORK_NOJOB && jp->jobctl && !oldlvl) {
-               pid_t pgrp;
+       struct ifsregion *ifsp;
 
-               if (jp->nprocs == 0)
-                       pgrp = getpid();
-               else
-                       pgrp = jp->ps[0].pid;
-               /* This can fail because we are doing it in the parent also */
-               (void)setpgid(0, pgrp);
-               if (mode == FORK_FG)
-                       xtcsetpgrp(ttyfd, pgrp);
-               setsignal(SIGTSTP);
-               setsignal(SIGTTOU);
-       } else
-#endif
-       if (mode == FORK_BG) {
-               ignoresig(SIGINT);
-               ignoresig(SIGQUIT);
-               if (jp->nprocs == 0) {
-                       close(0);
-                       if (open(bb_dev_null, O_RDONLY) != 0)
-                               sh_error("Can't open %s", bb_dev_null);
-               }
-       }
-       if (!oldlvl && iflag) {
-               setsignal(SIGINT);
-               setsignal(SIGQUIT);
-               setsignal(SIGTERM);
-       }
-       for (jp = curjob; jp; jp = jp->prev_job)
-               freejob(jp);
-       jobless = 0;
+       if (ifslastp == NULL) {
+               ifsp = &ifsfirst;
+       } else {
+               INT_OFF;
+               ifsp = ckmalloc(sizeof(*ifsp));
+               ifsp->next = NULL;
+               ifslastp->next = ifsp;
+               INT_ON;
+       }
+       ifslastp = ifsp;
+       ifslastp->begoff = start;
+       ifslastp->endoff = end;
+       ifslastp->nulonly = nulonly;
 }
 
-static void forkparent(struct job *jp, union node *n, int mode, pid_t pid)
+static void
+removerecordregions(int endoff)
 {
-       TRACE(("In parent shell:  child = %d\n", pid));
-       if (!jp) {
-               while (jobless && dowait(DOWAIT_NORMAL, 0) > 0);
-               jobless++;
+       if (ifslastp == NULL)
                return;
-       }
-#if JOBS
-       if (mode != FORK_NOJOB && jp->jobctl) {
-               int pgrp;
 
-               if (jp->nprocs == 0)
-                       pgrp = pid;
-               else
-                       pgrp = jp->ps[0].pid;
-               /* This can fail because we are doing it in the child also */
-               (void)setpgid(pid, pgrp);
-       }
-#endif
-       if (mode == FORK_BG) {
-               backgndpid = pid;               /* set $! */
-               set_curjob(jp, CUR_RUNNING);
+       if (ifsfirst.endoff > endoff) {
+               while (ifsfirst.next != NULL) {
+                       struct ifsregion *ifsp;
+                       INT_OFF;
+                       ifsp = ifsfirst.next->next;
+                       free(ifsfirst.next);
+                       ifsfirst.next = ifsp;
+                       INT_ON;
+               }
+               if (ifsfirst.begoff > endoff)
+                       ifslastp = NULL;
+               else {
+                       ifslastp = &ifsfirst;
+                       ifsfirst.endoff = endoff;
+               }
+               return;
        }
-       if (jp) {
-               struct procstat *ps = &jp->ps[jp->nprocs++];
-               ps->pid = pid;
-               ps->status = -1;
-               ps->cmd = nullstr;
-#if JOBS
-               if (jobctl && n)
-                       ps->cmd = commandtext(n);
-#endif
+
+       ifslastp = &ifsfirst;
+       while (ifslastp->next && ifslastp->next->begoff < endoff)
+               ifslastp=ifslastp->next;
+       while (ifslastp->next != NULL) {
+               struct ifsregion *ifsp;
+               INT_OFF;
+               ifsp = ifslastp->next->next;
+               free(ifslastp->next);
+               ifslastp->next = ifsp;
+               INT_ON;
        }
+       if (ifslastp->endoff > endoff)
+               ifslastp->endoff = endoff;
 }
 
-static int
-forkshell(struct job *jp, union node *n, int mode)
+static char *
+exptilde(char *startp, char *p, int flag)
 {
-       int pid;
+       char c;
+       char *name;
+       struct passwd *pw;
+       const char *home;
+       int quotes = flag & (EXP_FULL | EXP_CASE);
+       int startloc;
 
-       TRACE(("forkshell(%%%d, %p, %d) called\n", jobno(jp), n, mode));
-       pid = fork();
-       if (pid < 0) {
-               TRACE(("Fork failed, errno=%d", errno));
-               if (jp)
-                       freejob(jp);
-               sh_error("Cannot fork");
+       name = p + 1;
+
+       while ((c = *++p) != '\0') {
+               switch (c) {
+               case CTLESC:
+                       return startp;
+               case CTLQUOTEMARK:
+                       return startp;
+               case ':':
+                       if (flag & EXP_VARTILDE)
+                               goto done;
+                       break;
+               case '/':
+               case CTLENDVAR:
+                       goto done;
+               }
        }
-       if (pid == 0)
-               forkchild(jp, n, mode);
-       else
-               forkparent(jp, n, mode, pid);
-       return pid;
+ done:
+       *p = '\0';
+       if (*name == '\0') {
+               home = lookupvar(homestr);
+       } else {
+               pw = getpwnam(name);
+               if (pw == NULL)
+                       goto lose;
+               home = pw->pw_dir;
+       }
+       if (!home || !*home)
+               goto lose;
+       *p = c;
+       startloc = expdest - (char *)stackblock();
+       strtodest(home, SQSYNTAX, quotes);
+       recordregion(startloc, expdest - (char *)stackblock(), 0);
+       return p;
+ lose:
+       *p = c;
+       return startp;
 }
 
 /*
- * Wait for job to finish.
- *
- * Under job control we have the problem that while a child process is
- * running interrupts generated by the user are sent to the child but not
- * to the shell.  This means that an infinite loop started by an inter-
- * active user may be hard to kill.  With job control turned off, an
- * interactive user may place an interactive program inside a loop.  If
- * the interactive program catches interrupts, the user doesn't want
- * these interrupts to also abort the loop.  The approach we take here
- * is to have the shell ignore interrupt signals while waiting for a
- * foreground process to terminate, and then send itself an interrupt
- * signal if the child process was terminated by an interrupt signal.
- * Unfortunately, some programs want to do a bit of cleanup and then
- * exit on interrupt; unless these processes terminate themselves by
- * sending a signal to themselves (instead of calling exit) they will
- * confuse this approach.
- *
- * Called with interrupts off.
+ * Execute a command inside back quotes.  If it's a builtin command, we
+ * want to save its output in a block obtained from malloc.  Otherwise
+ * we fork off a subprocess and get the output of the command via a pipe.
+ * Should be called with interrupts off.
  */
+struct backcmd {                /* result of evalbackcmd */
+       int fd;                 /* file descriptor to read from */
+       char *buf;              /* buffer */
+       int nleft;              /* number of chars in buffer */
+       struct job *jp;         /* job structure for command */
+};
 
-int
-waitforjob(struct job *jp)
+/* These forward decls are needed to use "eval" code for backticks handling: */
+static int back_exitstatus; /* exit status of backquoted command */
+#define EV_EXIT 01              /* exit after evaluating tree */
+static void evaltree(union node *, int);
+
+static void
+evalbackcmd(union node *n, struct backcmd *result)
 {
-       int st;
+       int saveherefd;
 
-       TRACE(("waitforjob(%%%d) called\n", jobno(jp)));
-       while (jp->state == JOBRUNNING) {
-               dowait(DOWAIT_BLOCK, jp);
+       result->fd = -1;
+       result->buf = NULL;
+       result->nleft = 0;
+       result->jp = NULL;
+       if (n == NULL) {
+               goto out;
        }
-       st = getstatus(jp);
-#if JOBS
-       if (jp->jobctl) {
-               xtcsetpgrp(ttyfd, rootpid);
-               /*
-                * This is truly gross.
-                * If we're doing job control, then we did a TIOCSPGRP which
-                * caused us (the shell) to no longer be in the controlling
-                * session -- so we wouldn't have seen any ^C/SIGINT.  So, we
-                * intuit from the subprocess exit status whether a SIGINT
-                * occurred, and if so interrupt ourselves.  Yuck.  - mycroft
-                */
-               if (jp->sigint)
-                       raise(SIGINT);
+
+       saveherefd = herefd;
+       herefd = -1;
+
+       {
+               int pip[2];
+               struct job *jp;
+
+               if (pipe(pip) < 0)
+                       ash_msg_and_raise_error("pipe call failed");
+               jp = makejob(n, 1);
+               if (forkshell(jp, n, FORK_NOJOB) == 0) {
+                       FORCE_INT_ON;
+                       close(pip[0]);
+                       if (pip[1] != 1) {
+                               close(1);
+                               copyfd(pip[1], 1);
+                               close(pip[1]);
+                       }
+                       eflag = 0;
+                       evaltree(n, EV_EXIT); /* actually evaltreenr... */
+                       /* NOTREACHED */
+               }
+               close(pip[1]);
+               result->fd = pip[0];
+               result->jp = jp;
        }
-       if (jp->state == JOBDONE)
-#endif
-               freejob(jp);
-       return st;
+       herefd = saveherefd;
+ out:
+       TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n",
+               result->fd, result->buf, result->nleft, result->jp));
 }
 
-
 /*
- * Do a wait system call.  If job control is compiled in, we accept
- * stopped processes.  If block is zero, we return a value of zero
- * rather than blocking.
- *
- * System V doesn't have a non-blocking wait system call.  It does
- * have a SIGCLD signal that is sent to a process when one of it's
- * children dies.  The obvious way to use SIGCLD would be to install
- * a handler for SIGCLD which simply bumped a counter when a SIGCLD
- * was received, and have waitproc bump another counter when it got
- * the status of a process.  Waitproc would then know that a wait
- * system call would not block if the two counters were different.
- * This approach doesn't work because if a process has children that
- * have not been waited for, System V will send it a SIGCLD when it
- * installs a signal handler for SIGCLD.  What this means is that when
- * a child exits, the shell will be sent SIGCLD signals continuously
- * until is runs out of stack space, unless it does a wait call before
- * restoring the signal handler.  The code below takes advantage of
- * this (mis)feature by installing a signal handler for SIGCLD and
- * then checking to see whether it was called.  If there are any
- * children to be waited for, it will be.
- *
- * If neither SYSV nor BSD is defined, we don't implement nonblocking
- * waits at all.  In this case, the user will not be informed when
- * a background process until the next time she runs a real program
- * (as opposed to running a builtin command or just typing return),
- * and the jobs command may give out of date information.
+ * Expand stuff in backwards quotes.
  */
+static void
+expbackq(union node *cmd, int quoted, int quotes)
+{
+       struct backcmd in;
+       int i;
+       char buf[128];
+       char *p;
+       char *dest;
+       int startloc;
+       int syntax = quoted? DQSYNTAX : BASESYNTAX;
+       struct stackmark smark;
+
+       INT_OFF;
+       setstackmark(&smark);
+       dest = expdest;
+       startloc = dest - (char *)stackblock();
+       grabstackstr(dest);
+       evalbackcmd(cmd, &in);
+       popstackmark(&smark);
+
+       p = in.buf;
+       i = in.nleft;
+       if (i == 0)
+               goto read;
+       for (;;) {
+               memtodest(p, i, syntax, quotes);
+ read:
+               if (in.fd < 0)
+                       break;
+               i = safe_read(in.fd, buf, sizeof(buf));
+               TRACE(("expbackq: read returns %d\n", i));
+               if (i <= 0)
+                       break;
+               p = buf;
+       }
 
-static int waitproc(int block, int *status)
-{
-       int flags = 0;
+       free(in.buf);
+       if (in.fd >= 0) {
+               close(in.fd);
+               back_exitstatus = waitforjob(in.jp);
+       }
+       INT_ON;
 
-#if JOBS
-       if (jobctl)
-               flags |= WUNTRACED;
-#endif
-       if (block == 0)
-               flags |= WNOHANG;
-       return wait3(status, flags, (struct rusage *)NULL);
+       /* Eat all trailing newlines */
+       dest = expdest;
+       for (; dest > (char *)stackblock() && dest[-1] == '\n';)
+               STUNPUTC(dest);
+       expdest = dest;
+
+       if (quoted == 0)
+               recordregion(startloc, dest - (char *)stackblock(), 0);
+       TRACE(("evalbackq: size=%d: \"%.*s\"\n",
+               (dest - (char *)stackblock()) - startloc,
+               (dest - (char *)stackblock()) - startloc,
+               stackblock() + startloc));
 }
 
+#if ENABLE_ASH_MATH_SUPPORT
 /*
- * Wait for a process to terminate.
+ * Expand arithmetic expression.  Backup to start of expression,
+ * evaluate, place result in (backed up) result, adjust string position.
  */
-
-static int
-dowait(int block, struct job *job)
+static void
+expari(int quotes)
 {
-       int pid;
-       int status;
-       struct job *jp;
-       struct job *thisjob;
-       int state;
+       char *p, *start;
+       int begoff;
+       int flag;
+       int len;
 
-       TRACE(("dowait(%d) called\n", block));
-       pid = waitproc(block, &status);
-       TRACE(("wait returns pid %d, status=%d\n", pid, status));
-       if (pid <= 0)
-               return pid;
-       INTOFF;
-       thisjob = NULL;
-       for (jp = curjob; jp; jp = jp->prev_job) {
-               struct procstat *sp;
-               struct procstat *spend;
-               if (jp->state == JOBDONE)
-                       continue;
-               state = JOBDONE;
-               spend = jp->ps + jp->nprocs;
-               sp = jp->ps;
-               do {
-                       if (sp->pid == pid) {
-                               TRACE(("Job %d: changing status of proc %d from 0x%x to 0x%x\n", jobno(jp), pid, sp->status, status));
-                               sp->status = status;
-                               thisjob = jp;
-                       }
-                       if (sp->status == -1)
-                               state = JOBRUNNING;
-#if JOBS
-                       if (state == JOBRUNNING)
-                               continue;
-                       if (WIFSTOPPED(sp->status)) {
-                               jp->stopstatus = sp->status;
-                               state = JOBSTOPPED;
+       /*      ifsfree(); */
+
+       /*
+        * This routine is slightly over-complicated for
+        * efficiency.  Next we scan backwards looking for the
+        * start of arithmetic.
+        */
+       start = stackblock();
+       p = expdest - 1;
+       *p = '\0';
+       p--;
+       do {
+               int esc;
+
+               while (*p != CTLARI) {
+                       p--;
+#if DEBUG
+                       if (p < start) {
+                               ash_msg_and_raise_error("missing CTLARI (shouldn't happen)");
                        }
 #endif
-               } while (++sp < spend);
-               if (thisjob)
-                       goto gotjob;
-       }
-#if JOBS
-       if (!WIFSTOPPED(status))
-#endif
+               }
 
-               jobless--;
-       goto out;
+               esc = esclen(start, p);
+               if (!(esc % 2)) {
+                       break;
+               }
 
-gotjob:
-       if (state != JOBRUNNING) {
-               thisjob->changed = 1;
+               p -= esc + 1;
+       } while (1);
 
-               if (thisjob->state != state) {
-                       TRACE(("Job %d: changing state from %d to %d\n", jobno(thisjob), thisjob->state, state));
-                       thisjob->state = state;
-#if JOBS
-                       if (state == JOBSTOPPED) {
-                               set_curjob(thisjob, CUR_STOPPED);
-                       }
+       begoff = p - start;
+
+       removerecordregions(begoff);
+
+       flag = p[1];
+
+       expdest = p;
+
+       if (quotes)
+               rmescapes(p + 2);
+
+       len = cvtnum(dash_arith(p + 2));
+
+       if (flag != '"')
+               recordregion(begoff, begoff + len, 0);
+}
 #endif
-               }
+
+/* argstr needs it */
+static char *evalvar(char *p, int flag);
+
+/*
+ * Perform variable and command substitution.  If EXP_FULL is set, output CTLESC
+ * characters to allow for further processing.  Otherwise treat
+ * $@ like $* since no splitting will be performed.
+ */
+static void
+argstr(char *p, int flag)
+{
+       static const char spclchars[] ALIGN1 = {
+               '=',
+               ':',
+               CTLQUOTEMARK,
+               CTLENDVAR,
+               CTLESC,
+               CTLVAR,
+               CTLBACKQ,
+               CTLBACKQ | CTLQUOTE,
+#if ENABLE_ASH_MATH_SUPPORT
+               CTLENDARI,
+#endif
+               0
+       };
+       const char *reject = spclchars;
+       int c;
+       int quotes = flag & (EXP_FULL | EXP_CASE);      /* do CTLESC */
+       int breakall = flag & EXP_WORD;
+       int inquotes;
+       size_t length;
+       int startloc;
+
+       if (!(flag & EXP_VARTILDE)) {
+               reject += 2;
+       } else if (flag & EXP_VARTILDE2) {
+               reject++;
        }
+       inquotes = 0;
+       length = 0;
+       if (flag & EXP_TILDE) {
+               char *q;
 
-out:
-       INTON;
+               flag &= ~EXP_TILDE;
+ tilde:
+               q = p;
+               if (*q == CTLESC && (flag & EXP_QWORD))
+                       q++;
+               if (*q == '~')
+                       p = exptilde(p, q, flag);
+       }
+ start:
+       startloc = expdest - (char *)stackblock();
+       for (;;) {
+               length += strcspn(p + length, reject);
+               c = p[length];
+               if (c && (!(c & 0x80)
+#if ENABLE_ASH_MATH_SUPPORT
+                                       || c == CTLENDARI
+#endif
+                  )) {
+                       /* c == '=' || c == ':' || c == CTLENDARI */
+                       length++;
+               }
+               if (length > 0) {
+                       int newloc;
+                       expdest = stack_nputstr(p, length, expdest);
+                       newloc = expdest - (char *)stackblock();
+                       if (breakall && !inquotes && newloc > startloc) {
+                               recordregion(startloc, newloc, 0);
+                       }
+                       startloc = newloc;
+               }
+               p += length + 1;
+               length = 0;
 
-       if (thisjob && thisjob == job) {
-               char s[48 + 1];
-               int len;
+               switch (c) {
+               case '\0':
+                       goto breakloop;
+               case '=':
+                       if (flag & EXP_VARTILDE2) {
+                               p--;
+                               continue;
+                       }
+                       flag |= EXP_VARTILDE2;
+                       reject++;
+                       /* fall through */
+               case ':':
+                       /*
+                        * sort of a hack - expand tildes in variable
+                        * assignments (after the first '=' and after ':'s).
+                        */
+                       if (*--p == '~') {
+                               goto tilde;
+                       }
+                       continue;
+               }
 
-               len = sprint_status(s, status, 1);
-               if (len) {
-                       s[len] = '\n';
-                       s[len + 1] = 0;
-                       out2str(s);
+               switch (c) {
+               case CTLENDVAR: /* ??? */
+                       goto breakloop;
+               case CTLQUOTEMARK:
+                       /* "$@" syntax adherence hack */
+                       if (
+                               !inquotes &&
+                               !memcmp(p, dolatstr, 4) &&
+                               (p[4] == CTLQUOTEMARK || (
+                                       p[4] == CTLENDVAR &&
+                                       p[5] == CTLQUOTEMARK
+                               ))
+                       ) {
+                               p = evalvar(p + 1, flag) + 1;
+                               goto start;
+                       }
+                       inquotes = !inquotes;
+ addquote:
+                       if (quotes) {
+                               p--;
+                               length++;
+                               startloc++;
+                       }
+                       break;
+               case CTLESC:
+                       startloc++;
+                       length++;
+                       goto addquote;
+               case CTLVAR:
+                       p = evalvar(p, flag);
+                       goto start;
+               case CTLBACKQ:
+                       c = 0;
+               case CTLBACKQ|CTLQUOTE:
+                       expbackq(argbackq->n, c, quotes);
+                       argbackq = argbackq->next;
+                       goto start;
+#if ENABLE_ASH_MATH_SUPPORT
+               case CTLENDARI:
+                       p--;
+                       expari(quotes);
+                       goto start;
+#endif
                }
        }
-       return pid;
+ breakloop:
+       ;
 }
 
-
-/*
- * return 1 if there are stopped jobs, otherwise 0
- */
-
-int
-stoppedjobs(void)
+static char *
+scanleft(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
+       int zero)
 {
-       struct job *jp;
-       int retval;
-
-       retval = 0;
-       if (job_warning)
-               goto out;
-       jp = curjob;
-       if (jp && jp->state == JOBSTOPPED) {
-               out2str("You have stopped jobs.\n");
-               job_warning = 2;
-               retval++;
-       }
+       char *loc;
+       char *loc2;
+       char c;
 
-out:
-       return retval;
+       loc = startp;
+       loc2 = rmesc;
+       do {
+               int match;
+               const char *s = loc2;
+               c = *loc2;
+               if (zero) {
+                       *loc2 = '\0';
+                       s = rmesc;
+               }
+               match = pmatch(str, s);
+               *loc2 = c;
+               if (match)
+                       return loc;
+               if (quotes && *loc == CTLESC)
+                       loc++;
+               loc++;
+               loc2++;
+       } while (c);
+       return 0;
 }
 
-/*
- * Return a string identifying a command (to be printed by the
- * jobs command).
- */
-
-#if JOBS
-static char *cmdnextc;
-
 static char *
-commandtext(union node *n)
+scanright(char *startp, char *rmesc, char *rmescend, char *str, int quotes,
+       int zero)
 {
-       char *name;
+       int esc = 0;
+       char *loc;
+       char *loc2;
 
-       STARTSTACKSTR(cmdnextc);
-       cmdtxt(n);
-       name = stackblock();
-       TRACE(("commandtext: name %p, end %p\n\t\"%s\"\n",
-               name, cmdnextc, cmdnextc));
-       return savestr(name);
+       for (loc = str - 1, loc2 = rmescend; loc >= startp; loc2--) {
+               int match;
+               char c = *loc2;
+               const char *s = loc2;
+               if (zero) {
+                       *loc2 = '\0';
+                       s = rmesc;
+               }
+               match = pmatch(str, s);
+               *loc2 = c;
+               if (match)
+                       return loc;
+               loc--;
+               if (quotes) {
+                       if (--esc < 0) {
+                               esc = esclen(startp, loc);
+                       }
+                       if (esc % 2) {
+                               esc--;
+                               loc--;
+                       }
+               }
+       }
+       return 0;
 }
 
+static void varunset(const char *, const char *, const char *, int) ATTRIBUTE_NORETURN;
 static void
-cmdtxt(union node *n)
+varunset(const char *end, const char *var, const char *umsg, int varflags)
 {
-       union node *np;
-       struct nodelist *lp;
-       const char *p;
-       char s[2];
+       const char *msg;
+       const char *tail;
 
-       if (!n)
-               return;
-       switch (n->type) {
-       default:
-#if DEBUG
-               abort();
-#endif
-       case NPIPE:
-               lp = n->npipe.cmdlist;
-               for (;;) {
-                       cmdtxt(lp->n);
-                       lp = lp->next;
-                       if (!lp)
-                               break;
-                       cmdputs(" | ");
-               }
-               break;
-       case NSEMI:
-               p = "; ";
-               goto binop;
-       case NAND:
-               p = " && ";
-               goto binop;
-       case NOR:
-               p = " || ";
-binop:
-               cmdtxt(n->nbinary.ch1);
-               cmdputs(p);
-               n = n->nbinary.ch2;
-               goto donode;
-       case NREDIR:
-       case NBACKGND:
-               n = n->nredir.n;
-               goto donode;
-       case NNOT:
-               cmdputs("!");
-               n = n->nnot.com;
-donode:
-               cmdtxt(n);
-               break;
-       case NIF:
-               cmdputs("if ");
-               cmdtxt(n->nif.test);
-               cmdputs("; then ");
-               n = n->nif.ifpart;
-               if (n->nif.elsepart) {
-                       cmdtxt(n);
-                       cmdputs("; else ");
-                       n = n->nif.elsepart;
-               }
-               p = "; fi";
-               goto dotail;
-       case NSUBSHELL:
-               cmdputs("(");
-               n = n->nredir.n;
-               p = ")";
-               goto dotail;
-       case NWHILE:
-               p = "while ";
-               goto until;
-       case NUNTIL:
-               p = "until ";
-until:
-               cmdputs(p);
-               cmdtxt(n->nbinary.ch1);
-               n = n->nbinary.ch2;
-               p = "; done";
-dodo:
-               cmdputs("; do ");
-dotail:
-               cmdtxt(n);
-               goto dotail2;
-       case NFOR:
-               cmdputs("for ");
-               cmdputs(n->nfor.var);
-               cmdputs(" in ");
-               cmdlist(n->nfor.args, 1);
-               n = n->nfor.body;
-               p = "; done";
-               goto dodo;
-       case NDEFUN:
-               cmdputs(n->narg.text);
-               p = "() { ... }";
-               goto dotail2;
-       case NCMD:
-               cmdlist(n->ncmd.args, 1);
-               cmdlist(n->ncmd.redirect, 0);
-               break;
-       case NARG:
-               p = n->narg.text;
-dotail2:
-               cmdputs(p);
-               break;
-       case NHERE:
-       case NXHERE:
-               p = "<<...";
-               goto dotail2;
-       case NCASE:
-               cmdputs("case ");
-               cmdputs(n->ncase.expr->narg.text);
-               cmdputs(" in ");
-               for (np = n->ncase.cases; np; np = np->nclist.next) {
-                       cmdtxt(np->nclist.pattern);
-                       cmdputs(") ");
-                       cmdtxt(np->nclist.body);
-                       cmdputs(";; ");
-               }
-               p = "esac";
-               goto dotail2;
-       case NTO:
-               p = ">";
-               goto redir;
-       case NCLOBBER:
-               p = ">|";
-               goto redir;
-       case NAPPEND:
-               p = ">>";
-               goto redir;
-       case NTOFD:
-               p = ">&";
-               goto redir;
-       case NFROM:
-               p = "<";
-               goto redir;
-       case NFROMFD:
-               p = "<&";
-               goto redir;
-       case NFROMTO:
-               p = "<>";
-redir:
-               s[0] = n->nfile.fd + '0';
-               s[1] = '\0';
-               cmdputs(s);
-               cmdputs(p);
-               if (n->type == NTOFD || n->type == NFROMFD) {
-                       s[0] = n->ndup.dupfd + '0';
-                       p = s;
-                       goto dotail2;
-               } else {
-                       n = n->nfile.fname;
-                       goto donode;
-               }
+       tail = nullstr;
+       msg = "parameter not set";
+       if (umsg) {
+               if (*end == CTLENDVAR) {
+                       if (varflags & VSNUL)
+                               tail = " or null";
+               } else
+                       msg = umsg;
        }
+       ash_msg_and_raise_error("%.*s: %s%s", end - var - 1, var, msg, tail);
 }
 
-static void
-cmdlist(union node *np, int sep)
-{
-       for (; np; np = np->narg.next) {
-               if (!sep)
-                       cmdputs(spcstr);
-               cmdtxt(np);
-               if (sep && np->narg.next)
-                       cmdputs(spcstr);
+static const char *
+subevalvar(char *p, char *str, int strloc, int subtype, int startloc, int varflags, int quotes)
+{
+       char *startp;
+       char *loc;
+       int saveherefd = herefd;
+       struct nodelist *saveargbackq = argbackq;
+       int amount;
+       char *rmesc, *rmescend;
+       int zero;
+       char *(*scan)(char *, char *, char *, char *, int , int);
+
+       herefd = -1;
+       argstr(p, subtype != VSASSIGN && subtype != VSQUESTION ? EXP_CASE : 0);
+       STPUTC('\0', expdest);
+       herefd = saveherefd;
+       argbackq = saveargbackq;
+       startp = stackblock() + startloc;
+
+       switch (subtype) {
+       case VSASSIGN:
+               setvar(str, startp, 0);
+               amount = startp - expdest;
+               STADJUST(amount, expdest);
+               return startp;
+
+       case VSQUESTION:
+               varunset(p, str, startp, varflags);
+               /* NOTREACHED */
        }
-}
 
-static void
-cmdputs(const char *s)
-{
-       const char *p, *str;
-       char c, cc[2] = " ";
-       char *nextc;
-       int subtype = 0;
-       int quoted = 0;
-       static const char vstype[VSTYPE + 1][4] = {
-               "", "}", "-", "+", "?", "=",
-               "%", "%%", "#", "##"
-       };
-       nextc = makestrspace((strlen(s) + 1) * 8, cmdnextc);
-       p = s;
-       while ((c = *p++) != 0) {
-               str = 0;
-               switch (c) {
-               case CTLESC:
-                       c = *p++;
-                       break;
-               case CTLVAR:
-                       subtype = *p++;
-                       if ((subtype & VSTYPE) == VSLENGTH)
-                               str = "${#";
-                       else
-                               str = "${";
-                       if (!(subtype & VSQUOTE) != !(quoted & 1)) {
-                               quoted ^= 1;
-                               c = '"';
-                       } else
-                               goto dostr;
-                       break;
-               case CTLENDVAR:
-                       str = "\"}" + !(quoted & 1);
-                       quoted >>= 1;
-                       subtype = 0;
-                       goto dostr;
-               case CTLBACKQ:
-                       str = "$(...)";
-                       goto dostr;
-               case CTLBACKQ+CTLQUOTE:
-                       str = "\"$(...)\"";
-                       goto dostr;
-#ifdef CONFIG_ASH_MATH_SUPPORT
-               case CTLARI:
-                       str = "$((";
-                       goto dostr;
-               case CTLENDARI:
-                       str = "))";
-                       goto dostr;
+       subtype -= VSTRIMRIGHT;
+#if DEBUG
+       if (subtype < 0 || subtype > 3)
+               abort();
 #endif
-               case CTLQUOTEMARK:
-                       quoted ^= 1;
-                       c = '"';
-                       break;
-               case '=':
-                       if (subtype == 0)
-                               break;
-                       if ((subtype & VSTYPE) != VSNORMAL)
-                               quoted <<= 1;
-                       str = vstype[subtype & VSTYPE];
-                       if (subtype & VSNUL)
-                               c = ':';
-                       else
-                               goto checkstr;
-                       break;
-               case '\'':
-               case '\\':
-               case '"':
-               case '$':
-                       /* These can only happen inside quotes */
-                       cc[0] = c;
-                       str = cc;
-                       c = '\\';
-                       break;
-               default:
-                       break;
-               }
-               USTPUTC(c, nextc);
-checkstr:
-               if (!str)
-                       continue;
-dostr:
-               while ((c = *str++)) {
-                       USTPUTC(c, nextc);
+
+       rmesc = startp;
+       rmescend = stackblock() + strloc;
+       if (quotes) {
+               rmesc = _rmescapes(startp, RMESCAPE_ALLOC | RMESCAPE_GROW);
+               if (rmesc != startp) {
+                       rmescend = expdest;
+                       startp = stackblock() + startloc;
                }
        }
-       if (quoted & 1) {
-               USTPUTC('"', nextc);
+       rmescend--;
+       str = stackblock() + strloc;
+       preglob(str, varflags & VSQUOTE, 0);
+
+       /* zero = subtype == VSTRIMLEFT || subtype == VSTRIMLEFTMAX */
+       zero = subtype >> 1;
+       /* VSTRIMLEFT/VSTRIMRIGHTMAX -> scanleft */
+       scan = (subtype & 1) ^ zero ? scanleft : scanright;
+
+       loc = scan(startp, rmesc, rmescend, str, quotes, zero);
+       if (loc) {
+               if (zero) {
+                       memmove(startp, loc, str - loc);
+                       loc = startp + (str - loc) - 1;
+               }
+               *loc = '\0';
+               amount = loc - expdest;
+               STADJUST(amount, expdest);
        }
-       *nextc = 0;
-       cmdnextc = nextc;
+       return loc;
 }
 
-
-static void
-showpipe(struct job *jp, FILE *out)
+/*
+ * Add the value of a specialized variable to the stack string.
+ */
+static ssize_t
+varvalue(char *name, int varflags, int flags)
 {
-       struct procstat *sp;
-       struct procstat *spend;
+       int num;
+       char *p;
+       int i;
+       int sep = 0;
+       int sepq = 0;
+       ssize_t len = 0;
+       char **ap;
+       int syntax;
+       int quoted = varflags & VSQUOTE;
+       int subtype = varflags & VSTYPE;
+       int quotes = flags & (EXP_FULL | EXP_CASE);
 
-       spend = jp->ps + jp->nprocs;
-       for (sp = jp->ps + 1; sp < spend; sp++)
-               fprintf(out, " | %s", sp->cmd);
-       outcslow('\n', out);
-       flushall();
+       if (quoted && (flags & EXP_FULL))
+               sep = 1 << CHAR_BIT;
+
+       syntax = quoted ? DQSYNTAX : BASESYNTAX;
+       switch (*name) {
+       case '$':
+               num = rootpid;
+               goto numvar;
+       case '?':
+               num = exitstatus;
+               goto numvar;
+       case '#':
+               num = shellparam.nparam;
+               goto numvar;
+       case '!':
+               num = backgndpid;
+               if (num == 0)
+                       return -1;
+ numvar:
+               len = cvtnum(num);
+               break;
+       case '-':
+               p = makestrspace(NOPTS, expdest);
+               for (i = NOPTS - 1; i >= 0; i--) {
+                       if (optlist[i]) {
+                               USTPUTC(optletters(i), p);
+                               len++;
+                       }
+               }
+               expdest = p;
+               break;
+       case '@':
+               if (sep)
+                       goto param;
+               /* fall through */
+       case '*':
+               sep = ifsset() ? signed_char2int(ifsval()[0]) : ' ';
+               if (quotes && (SIT(sep, syntax) == CCTL || SIT(sep, syntax) == CBACK))
+                       sepq = 1;
+ param:
+               ap = shellparam.p;
+               if (!ap)
+                       return -1;
+               while ((p = *ap++)) {
+                       size_t partlen;
+
+                       partlen = strlen(p);
+                       len += partlen;
+
+                       if (!(subtype == VSPLUS || subtype == VSLENGTH))
+                               memtodest(p, partlen, syntax, quotes);
+
+                       if (*ap && sep) {
+                               char *q;
+
+                               len++;
+                               if (subtype == VSPLUS || subtype == VSLENGTH) {
+                                       continue;
+                               }
+                               q = expdest;
+                               if (sepq)
+                                       STPUTC(CTLESC, q);
+                               STPUTC(sep, q);
+                               expdest = q;
+                       }
+               }
+               return len;
+       case '0':
+       case '1':
+       case '2':
+       case '3':
+       case '4':
+       case '5':
+       case '6':
+       case '7':
+       case '8':
+       case '9':
+               num = atoi(name);
+               if (num < 0 || num > shellparam.nparam)
+                       return -1;
+               p = num ? shellparam.p[num - 1] : arg0;
+               goto value;
+       default:
+               p = lookupvar(name);
+ value:
+               if (!p)
+                       return -1;
+
+               len = strlen(p);
+               if (!(subtype == VSPLUS || subtype == VSLENGTH))
+                       memtodest(p, len, syntax, quotes);
+               return len;
+       }
+
+       if (subtype == VSPLUS || subtype == VSLENGTH)
+               STADJUST(-len, expdest);
+       return len;
 }
 
-static void
-xtcsetpgrp(int fd, pid_t pgrp)
+/*
+ * Expand a variable, and return a pointer to the next character in the
+ * input string.
+ */
+static char *
+evalvar(char *p, int flag)
 {
-       if (tcsetpgrp(fd, pgrp))
-               sh_error("Cannot set tty process group (%m)");
-}
-#endif /* JOBS */
+       int subtype;
+       int varflags;
+       char *var;
+       int patloc;
+       int c;
+       int startloc;
+       ssize_t varlen;
+       int easy;
+       int quotes;
+       int quoted;
 
-static int
-getstatus(struct job *job) {
-       int status;
-       int retval;
+       quotes = flag & (EXP_FULL | EXP_CASE);
+       varflags = *p++;
+       subtype = varflags & VSTYPE;
+       quoted = varflags & VSQUOTE;
+       var = p;
+       easy = (!quoted || (*var == '@' && shellparam.nparam));
+       startloc = expdest - (char *)stackblock();
+       p = strchr(p, '=') + 1;
 
-       status = job->ps[job->nprocs - 1].status;
-       retval = WEXITSTATUS(status);
-       if (!WIFEXITED(status)) {
-#if JOBS
-               retval = WSTOPSIG(status);
-               if (!WIFSTOPPED(status))
-#endif
-               {
-                       /* XXX: limits number of signals */
-                       retval = WTERMSIG(status);
-#if JOBS
-                       if (retval == SIGINT)
-                               job->sigint = 1;
-#endif
+ again:
+       varlen = varvalue(var, varflags, flag);
+       if (varflags & VSNUL)
+               varlen--;
+
+       if (subtype == VSPLUS) {
+               varlen = -1 - varlen;
+               goto vsplus;
+       }
+
+       if (subtype == VSMINUS) {
+ vsplus:
+               if (varlen < 0) {
+                       argstr(
+                               p, flag | EXP_TILDE |
+                                       (quoted ?  EXP_QWORD : EXP_WORD)
+                       );
+                       goto end;
                }
-               retval += 128;
+               if (easy)
+                       goto record;
+               goto end;
        }
-       TRACE(("getstatus: job %d, nproc %d, status %x, retval %x\n",
-               jobno(job), job->nprocs, status, retval));
-       return retval;
-}
 
-#ifdef CONFIG_ASH_MAIL
-/*      mail.c       */
+       if (subtype == VSASSIGN || subtype == VSQUESTION) {
+               if (varlen < 0) {
+                       if (subevalvar(p, var, 0, subtype, startloc, varflags, 0)) {
+                               varflags &= ~VSNUL;
+                               /*
+                                * Remove any recorded regions beyond
+                                * start of variable
+                                */
+                               removerecordregions(startloc);
+                               goto again;
+                       }
+                       goto end;
+               }
+               if (easy)
+                       goto record;
+               goto end;
+       }
 
-/*
- * Routines to check for mail.  (Perhaps make part of main.c?)
- */
+       if (varlen < 0 && uflag)
+               varunset(p, var, 0, 0);
 
-#define MAXMBOXES 10
+       if (subtype == VSLENGTH) {
+               cvtnum(varlen > 0 ? varlen : 0);
+               goto record;
+       }
 
-/* times of mailboxes */
-static time_t mailtime[MAXMBOXES];
-/* Set if MAIL or MAILPATH is changed. */
-static int mail_var_path_changed;
+       if (subtype == VSNORMAL) {
+               if (!easy)
+                       goto end;
+ record:
+               recordregion(startloc, expdest - (char *)stackblock(), quoted);
+               goto end;
+       }
+
+#if DEBUG
+       switch (subtype) {
+       case VSTRIMLEFT:
+       case VSTRIMLEFTMAX:
+       case VSTRIMRIGHT:
+       case VSTRIMRIGHTMAX:
+               break;
+       default:
+               abort();
+       }
+#endif
 
+       if (varlen >= 0) {
+               /*
+                * Terminate the string and start recording the pattern
+                * right after it
+                */
+               STPUTC('\0', expdest);
+               patloc = expdest - (char *)stackblock();
+               if (subevalvar(p, NULL, patloc, subtype,
+                               startloc, varflags, quotes) == 0) {
+                       int amount = expdest - (
+                               (char *)stackblock() + patloc - 1
+                       );
+                       STADJUST(-amount, expdest);
+               }
+               /* Remove any recorded regions beyond start of variable */
+               removerecordregions(startloc);
+               goto record;
+       }
 
+ end:
+       if (subtype != VSNORMAL) {      /* skip to end of alternative */
+               int nesting = 1;
+               for (;;) {
+                       c = *p++;
+                       if (c == CTLESC)
+                               p++;
+                       else if (c == CTLBACKQ || c == (CTLBACKQ|CTLQUOTE)) {
+                               if (varlen >= 0)
+                                       argbackq = argbackq->next;
+                       } else if (c == CTLVAR) {
+                               if ((*p++ & VSTYPE) != VSNORMAL)
+                                       nesting++;
+                       } else if (c == CTLENDVAR) {
+                               if (--nesting == 0)
+                                       break;
+                       }
+               }
+       }
+       return p;
+}
 
 /*
- * Print appropriate message(s) if mail has arrived.
- * If mail_var_path_changed is set,
- * then the value of MAIL has mail_var_path_changed,
- * so we just update the values.
+ * Break the argument string into pieces based upon IFS and add the
+ * strings to the argument list.  The regions of the string to be
+ * searched for IFS characters have been stored by recordregion.
  */
-
 static void
-chkmail(void)
+ifsbreakup(char *string, struct arglist *arglist)
 {
-       const char *mpath;
+       struct ifsregion *ifsp;
+       struct strlist *sp;
+       char *start;
        char *p;
        char *q;
-       time_t *mtp;
-       struct stackmark smark;
-       struct stat statb;
+       const char *ifs, *realifs;
+       int ifsspc;
+       int nulonly;
 
-       setstackmark(&smark);
-       mpath = mpathset() ? mpathval() : mailval();
-       for (mtp = mailtime; mtp < mailtime + MAXMBOXES; mtp++) {
-               p = padvance(&mpath, nullstr);
-               if (p == NULL)
-                       break;
-               if (*p == '\0')
-                       continue;
-               for (q = p ; *q ; q++);
-#if DEBUG
-               if (q[-1] != '/')
-                       abort();
-#endif
-               q[-1] = '\0';                   /* delete trailing '/' */
-               if (stat(p, &statb) < 0) {
-                       *mtp = 0;
-                       continue;
-               }
-               if (!mail_var_path_changed && statb.st_mtime != *mtp) {
-                       fprintf(
-                               stderr, snlfmt,
-                               pathopt ? pathopt : "you have mail"
-                       );
-               }
-               *mtp = statb.st_mtime;
+       start = string;
+       if (ifslastp != NULL) {
+               ifsspc = 0;
+               nulonly = 0;
+               realifs = ifsset() ? ifsval() : defifs;
+               ifsp = &ifsfirst;
+               do {
+                       p = string + ifsp->begoff;
+                       nulonly = ifsp->nulonly;
+                       ifs = nulonly ? nullstr : realifs;
+                       ifsspc = 0;
+                       while (p < string + ifsp->endoff) {
+                               q = p;
+                               if (*p == CTLESC)
+                                       p++;
+                               if (!strchr(ifs, *p)) {
+                                       p++;
+                                       continue;
+                               }
+                               if (!nulonly)
+                                       ifsspc = (strchr(defifs, *p) != NULL);
+                               /* Ignore IFS whitespace at start */
+                               if (q == start && ifsspc) {
+                                       p++;
+                                       start = p;
+                                       continue;
+                               }
+                               *q = '\0';
+                               sp = stalloc(sizeof(*sp));
+                               sp->text = start;
+                               *arglist->lastp = sp;
+                               arglist->lastp = &sp->next;
+                               p++;
+                               if (!nulonly) {
+                                       for (;;) {
+                                               if (p >= string + ifsp->endoff) {
+                                                       break;
+                                               }
+                                               q = p;
+                                               if (*p == CTLESC)
+                                                       p++;
+                                               if (strchr(ifs, *p) == NULL ) {
+                                                       p = q;
+                                                       break;
+                                               } else if (strchr(defifs, *p) == NULL) {
+                                                       if (ifsspc) {
+                                                               p++;
+                                                               ifsspc = 0;
+                                                       } else {
+                                                               p = q;
+                                                               break;
+                                                       }
+                                               } else
+                                                       p++;
+                                       }
+                               }
+                               start = p;
+                       } /* while */
+                       ifsp = ifsp->next;
+               } while (ifsp != NULL);
+               if (nulonly)
+                       goto add;
        }
-       mail_var_path_changed = 0;
-       popstackmark(&smark);
+
+       if (!*start)
+               return;
+
+ add:
+       sp = stalloc(sizeof(*sp));
+       sp->text = start;
+       *arglist->lastp = sp;
+       arglist->lastp = &sp->next;
 }
 
+static void
+ifsfree(void)
+{
+       struct ifsregion *p;
+
+       INT_OFF;
+       p = ifsfirst.next;
+       do {
+               struct ifsregion *ifsp;
+               ifsp = p->next;
+               free(p);
+               p = ifsp;
+       } while (p);
+       ifslastp = NULL;
+       ifsfirst.next = NULL;
+       INT_ON;
+}
 
+/*
+ * Add a file name to the list.
+ */
 static void
-changemail(const char *val)
+addfname(const char *name)
 {
-       mail_var_path_changed++;
-}
-
-#endif /* CONFIG_ASH_MAIL */
-
-/*      main.c       */
-
-
-#if PROFILE
-static short profile_buf[16384];
-extern int etext();
-#endif
+       struct strlist *sp;
 
-static int isloginsh;
+       sp = stalloc(sizeof(*sp));
+       sp->text = ststrdup(name);
+       *exparg.lastp = sp;
+       exparg.lastp = &sp->next;
+}
 
-static void read_profile(const char *);
+static char *expdir;
 
 /*
- * Main routine.  We initialize things, parse the arguments, execute
- * profiles if we're a login shell, and then call cmdloop to execute
- * commands.  The setjmp call sets up the location to jump to when an
- * exception occurs.  When an exception occurs the variable "state"
- * is used to figure out how far we had gotten.
+ * Do metacharacter (i.e. *, ?, [...]) expansion.
  */
-
-int
-ash_main(int argc, char **argv)
+static void
+expmeta(char *enddir, char *name)
 {
-       char *shinit;
-       volatile int state;
-       struct jmploc jmploc;
-       struct stackmark smark;
-
-#ifdef __GLIBC__
-       dash_errno = __errno_location();
-#endif
-
-#if PROFILE
-       monitor(4, etext, profile_buf, sizeof profile_buf, 50);
-#endif
-       state = 0;
-       if (setjmp(jmploc.loc)) {
-               int e;
-               int s;
-
-               reset();
-
-               e = exception;
-               if (e == EXERROR)
-                       exitstatus = 2;
-               s = state;
-               if (e == EXEXIT || s == 0 || iflag == 0 || shlvl)
-                       exitshell();
-
-               if (e == EXINT) {
-                       outcslow('\n', stderr);
-               }
-               popstackmark(&smark);
-               FORCEINTON;                             /* enable interrupts */
-               if (s == 1)
-                       goto state1;
-               else if (s == 2)
-                       goto state2;
-               else if (s == 3)
-                       goto state3;
-               else
-                       goto state4;
-       }
-       handler = &jmploc;
-#if DEBUG
-       opentrace();
-       trputs("Shell args:  ");  trargs(argv);
-#endif
-       rootpid = getpid();
-
-#ifdef CONFIG_ASH_RANDOM_SUPPORT
-       rseed = rootpid + ((time_t)time((time_t *)0));
-#endif
-       init();
-       setstackmark(&smark);
-       procargs(argc, argv);
-#ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY
-       if ( iflag ) {
-               const char *hp = lookupvar("HISTFILE");
+       char *p;
+       const char *cp;
+       char *start;
+       char *endname;
+       int metaflag;
+       struct stat statb;
+       DIR *dirp;
+       struct dirent *dp;
+       int atend;
+       int matchdot;
 
-               if(hp == NULL ) {
-                       hp = lookupvar("HOME");
-                       if(hp != NULL) {
-                               char *defhp = concat_path_file(hp, ".ash_history");
-                               setvar("HISTFILE", defhp, 0);
-                               free(defhp);
+       metaflag = 0;
+       start = name;
+       for (p = name; *p; p++) {
+               if (*p == '*' || *p == '?')
+                       metaflag = 1;
+               else if (*p == '[') {
+                       char *q = p + 1;
+                       if (*q == '!')
+                               q++;
+                       for (;;) {
+                               if (*q == '\\')
+                                       q++;
+                               if (*q == '/' || *q == '\0')
+                                       break;
+                               if (*++q == ']') {
+                                       metaflag = 1;
+                                       break;
+                               }
                        }
+               } else if (*p == '\\')
+                       p++;
+               else if (*p == '/') {
+                       if (metaflag)
+                               goto out;
+                       start = p + 1;
                }
        }
-#endif
-       if (argv[0] && argv[0][0] == '-')
-               isloginsh = 1;
-       if (isloginsh) {
-               state = 1;
-               read_profile("/etc/profile");
-state1:
-               state = 2;
-               read_profile(".profile");
+ out:
+       if (metaflag == 0) {    /* we've reached the end of the file name */
+               if (enddir != expdir)
+                       metaflag++;
+               p = name;
+               do {
+                       if (*p == '\\')
+                               p++;
+                       *enddir++ = *p;
+               } while (*p++);
+               if (metaflag == 0 || lstat(expdir, &statb) >= 0)
+                       addfname(expdir);
+               return;
        }
-state2:
-       state = 3;
-       if (
-#ifndef linux
-               getuid() == geteuid() && getgid() == getegid() &&
-#endif
-               iflag
-       ) {
-               if ((shinit = lookupvar("ENV")) != NULL && *shinit != '\0') {
-                       read_profile(shinit);
-               }
+       endname = p;
+       if (name < start) {
+               p = name;
+               do {
+                       if (*p == '\\')
+                               p++;
+                       *enddir++ = *p++;
+               } while (p < start);
        }
-state3:
-       state = 4;
-       if (minusc)
-               evalstring(minusc, 0);
-
-       if (sflag || minusc == NULL) {
-#ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY
-           if ( iflag ) {
-               const char *hp = lookupvar("HISTFILE");
-
-               if(hp != NULL )
-                       load_history ( hp );
-           }
-#endif
-state4: /* XXX ??? - why isn't this before the "if" statement */
-               cmdloop(1);
+       if (enddir == expdir) {
+               cp = ".";
+       } else if (enddir == expdir + 1 && *expdir == '/') {
+               cp = "/";
+       } else {
+               cp = expdir;
+               enddir[-1] = '\0';
        }
-#if PROFILE
-       monitor(0);
-#endif
-#ifdef GPROF
-       {
-               extern void _mcleanup(void);
-               _mcleanup();
+       dirp = opendir(cp);
+       if (dirp == NULL)
+               return;
+       if (enddir != expdir)
+               enddir[-1] = '/';
+       if (*endname == 0) {
+               atend = 1;
+       } else {
+               atend = 0;
+               *endname++ = '\0';
        }
-#endif
-       exitshell();
-       /* NOTREACHED */
+       matchdot = 0;
+       p = start;
+       if (*p == '\\')
+               p++;
+       if (*p == '.')
+               matchdot++;
+       while (! intpending && (dp = readdir(dirp)) != NULL) {
+               if (dp->d_name[0] == '.' && ! matchdot)
+                       continue;
+               if (pmatch(start, dp->d_name)) {
+                       if (atend) {
+                               strcpy(enddir, dp->d_name);
+                               addfname(expdir);
+                       } else {
+                               for (p = enddir, cp = dp->d_name; (*p++ = *cp++) != '\0';)
+                                       continue;
+                               p[-1] = '/';
+                               expmeta(p, endname);
+                       }
+               }
+       }
+       closedir(dirp);
+       if (! atend)
+               endname[-1] = '/';
 }
 
-
-/*
- * Read and execute commands.  "Top" is nonzero for the top level command
- * loop; it turns on prompting if the shell is interactive.
- */
-
-static int
-cmdloop(int top)
+static struct strlist *
+msort(struct strlist *list, int len)
 {
-       union node *n;
-       struct stackmark smark;
-       int inter;
-       int numeof = 0;
+       struct strlist *p, *q = NULL;
+       struct strlist **lpp;
+       int half;
+       int n;
 
-       TRACE(("cmdloop(%d) called\n", top));
+       if (len <= 1)
+               return list;
+       half = len >> 1;
+       p = list;
+       for (n = half; --n >= 0; ) {
+               q = p;
+               p = p->next;
+       }
+       q->next = NULL;                 /* terminate first half of list */
+       q = msort(list, half);          /* sort first half of list */
+       p = msort(p, len - half);               /* sort second half */
+       lpp = &list;
        for (;;) {
-               int skip;
-
-               setstackmark(&smark);
-#if JOBS
-               if (jobctl)
-                       showjobs(stderr, SHOW_CHANGED);
-#endif
-               inter = 0;
-               if (iflag && top) {
-                       inter++;
-#ifdef CONFIG_ASH_MAIL
-                       chkmail();
+#if ENABLE_LOCALE_SUPPORT
+               if (strcoll(p->text, q->text) < 0)
+#else
+               if (strcmp(p->text, q->text) < 0)
 #endif
-               }
-               n = parsecmd(inter);
-               /* showtree(n); DEBUG */
-               if (n == NEOF) {
-                       if (!top || numeof >= 50)
+                                               {
+                       *lpp = p;
+                       lpp = &p->next;
+                       p = *lpp;
+                       if (p == NULL) {
+                               *lpp = q;
+                               break;
+                       }
+               } else {
+                       *lpp = q;
+                       lpp = &q->next;
+                       q = *lpp;
+                       if (q == NULL) {
+                               *lpp = p;
                                break;
-                       if (!stoppedjobs()) {
-                               if (!Iflag)
-                                       break;
-                               out2str("\nUse \"exit\" to leave shell.\n");
                        }
-                       numeof++;
-               } else if (nflag == 0) {
-                       job_warning = (job_warning == 2) ? 1 : 0;
-                       numeof = 0;
-                       evaltree(n, 0);
-               }
-               popstackmark(&smark);
-               skip = evalskip;
-
-               if (skip) {
-                       evalskip = 0;
-                       return skip & SKIPEVAL;
                }
        }
-
-       return 0;
+       return list;
 }
 
-
 /*
- * Read /etc/profile or .profile.  Return on error.
+ * Sort the results of file name expansion.  It calculates the number of
+ * strings to sort and then calls msort (short for merge sort) to do the
+ * work.
  */
-
-static void
-read_profile(const char *name)
+static struct strlist *
+expsort(struct strlist *str)
 {
-       int skip;
-
-       if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0)
-               return;
-
-       skip = cmdloop(0);
-       popfile();
+       int len;
+       struct strlist *sp;
 
-       if (skip)
-               exitshell();
+       len = 0;
+       for (sp = str; sp; sp = sp->next)
+               len++;
+       return msort(str, len);
 }
 
-
-/*
- * Read a file containing shell functions.
- */
-
 static void
-readcmdfile(char *name)
+expandmeta(struct strlist *str, int flag)
 {
-       setinputfile(name, INPUT_PUSH_FILE);
-       cmdloop(0);
-       popfile();
-}
-
+       static const char metachars[] ALIGN1 = {
+               '*', '?', '[', 0
+       };
+       /* TODO - EXP_REDIR */
 
-/*
- * Take commands from a file.  To be compatible we should do a path
- * search for the file, which is necessary to find sub-commands.
- */
+       while (str) {
+               struct strlist **savelastp;
+               struct strlist *sp;
+               char *p;
 
-static char * find_dot_file(char *name)
-{
-       char *fullname;
-       const char *path = pathval();
-       struct stat statb;
+               if (fflag)
+                       goto nometa;
+               if (!strpbrk(str->text, metachars))
+                       goto nometa;
+               savelastp = exparg.lastp;
 
-       /* don't try this for absolute or relative paths */
-       if (strchr(name, '/'))
-               return name;
+               INT_OFF;
+               p = preglob(str->text, 0, RMESCAPE_ALLOC | RMESCAPE_HEAP);
+               {
+                       int i = strlen(str->text);
+                       expdir = ckmalloc(i < 2048 ? 2048 : i); /* XXX */
+               }
 
-       while ((fullname = padvance(&path, name)) != NULL) {
-               if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
+               expmeta(expdir, p);
+               free(expdir);
+               if (p != str->text)
+                       free(p);
+               INT_ON;
+               if (exparg.lastp == savelastp) {
                        /*
-                        * Don't bother freeing here, since it will
-                        * be freed by the caller.
+                        * no matches
                         */
-                       return fullname;
+ nometa:
+                       *exparg.lastp = str;
+                       rmescapes(str->text);
+                       exparg.lastp = &str->next;
+               } else {
+                       *exparg.lastp = NULL;
+                       *savelastp = sp = expsort(*savelastp);
+                       while (sp->next != NULL)
+                               sp = sp->next;
+                       exparg.lastp = &sp->next;
                }
-               stunalloc(fullname);
-       }
-
-       /* not found in the PATH */
-       sh_error(not_found_msg, name);
-       /* NOTREACHED */
-}
-
-static int dotcmd(int argc, char **argv)
-{
-       struct strlist *sp;
-       volatile struct shparam saveparam;
-       int status = 0;
-
-       for (sp = cmdenviron; sp; sp = sp->next)
-               setvareq(xstrdup(sp->text), VSTRFIXED | VTEXTFIXED);
-
-       if (argc >= 2) {        /* That's what SVR2 does */
-               char *fullname;
-
-               fullname = find_dot_file(argv[1]);
-
-               if (argc > 2) {
-                       saveparam = shellparam;
-                       shellparam.malloc = 0;
-                       shellparam.nparam = argc - 2;
-                       shellparam.p = argv + 2;
-               };
-
-               setinputfile(fullname, INPUT_PUSH_FILE);
-               commandname = fullname;
-               cmdloop(0);
-               popfile();
-
-               if (argc > 2) {
-                       freeparam(&shellparam);
-                       shellparam = saveparam;
-               };
-               status = exitstatus;
+               str = str->next;
        }
-       return status;
-}
-
-
-static int
-exitcmd(int argc, char **argv)
-{
-       if (stoppedjobs())
-               return 0;
-       if (argc > 1)
-               exitstatus = number(argv[1]);
-       exraise(EXEXIT);
-       /* NOTREACHED */
-}
-
-#ifdef CONFIG_ASH_BUILTIN_ECHO
-static int
-echocmd(int argc, char **argv)
-{
-       return bb_echo(argc, argv);
-}
-#endif
-
-#ifdef CONFIG_ASH_BUILTIN_TEST
-static int
-testcmd(int argc, char **argv)
-{
-       return bb_test(argc, argv);
-}
-#endif
-
-/*      memalloc.c        */
-
-/*
- * Same for malloc, realloc, but returns an error when out of space.
- */
-
-static pointer
-ckrealloc(pointer p, size_t nbytes)
-{
-       p = realloc(p, nbytes);
-       if (p == NULL)
-               sh_error(bb_msg_memory_exhausted);
-       return p;
-}
-
-static pointer
-ckmalloc(size_t nbytes)
-{
-       return ckrealloc(NULL, nbytes);
-}
-
-/*
- * Make a copy of a string in safe storage.
- */
-
-static char *
-savestr(const char *s)
-{
-       char *p = strdup(s);
-       if (!p)
-               sh_error(bb_msg_memory_exhausted);
-       return p;
 }
 
-
 /*
- * Parse trees for commands are allocated in lifo order, so we use a stack
- * to make this more efficient, and also to avoid all sorts of exception
- * handling code to handle interrupts in the middle of a parse.
- *
- * The size 504 was chosen because the Ultrix malloc handles that size
- * well.
+ * Perform variable substitution and command substitution on an argument,
+ * placing the resulting list of arguments in arglist.  If EXP_FULL is true,
+ * perform splitting and file name expansion.  When arglist is NULL, perform
+ * here document expansion.
  */
-
-
-static pointer
-stalloc(size_t nbytes)
+static void
+expandarg(union node *arg, struct arglist *arglist, int flag)
 {
+       struct strlist *sp;
        char *p;
-       size_t aligned;
-
-       aligned = SHELL_ALIGN(nbytes);
-       if (aligned > stacknleft) {
-               size_t len;
-               size_t blocksize;
-               struct stack_block *sp;
 
-               blocksize = aligned;
-               if (blocksize < MINSIZE)
-                       blocksize = MINSIZE;
-               len = sizeof(struct stack_block) - MINSIZE + blocksize;
-               if (len < blocksize)
-                       sh_error(bb_msg_memory_exhausted);
-               INTOFF;
-               sp = ckmalloc(len);
-               sp->prev = stackp;
-               stacknxt = sp->space;
-               stacknleft = blocksize;
-               sstrend = stacknxt + blocksize;
-               stackp = sp;
-               INTON;
+       argbackq = arg->narg.backquote;
+       STARTSTACKSTR(expdest);
+       ifsfirst.next = NULL;
+       ifslastp = NULL;
+       argstr(arg->narg.text, flag);
+       p = _STPUTC('\0', expdest);
+       expdest = p - 1;
+       if (arglist == NULL) {
+               return;                 /* here document expanded */
+       }
+       p = grabstackstr(p);
+       exparg.lastp = &exparg.list;
+       /*
+        * TODO - EXP_REDIR
+        */
+       if (flag & EXP_FULL) {
+               ifsbreakup(p, &exparg);
+               *exparg.lastp = NULL;
+               exparg.lastp = &exparg.list;
+               expandmeta(exparg.list, flag);
+       } else {
+               if (flag & EXP_REDIR) /*XXX - for now, just remove escapes */
+                       rmescapes(p);
+               sp = stalloc(sizeof(*sp));
+               sp->text = p;
+               *exparg.lastp = sp;
+               exparg.lastp = &sp->next;
+       }
+       if (ifsfirst.next)
+               ifsfree();
+       *exparg.lastp = NULL;
+       if (exparg.list) {
+               *arglist->lastp = exparg.list;
+               arglist->lastp = exparg.lastp;
        }
-       p = stacknxt;
-       stacknxt += aligned;
-       stacknleft -= aligned;
-       return p;
 }
 
-
-void
-stunalloc(pointer p)
+/*
+ * Expand shell variables and backquotes inside a here document.
+ */
+static void
+expandhere(union node *arg, int fd)
 {
-#if DEBUG
-       if (!p || (stacknxt < (char *)p) || ((char *)p < stackp->space)) {
-               write(2, "stunalloc\n", 10);
-               abort();
-       }
-#endif
-       stacknleft += stacknxt - (char *)p;
-       stacknxt = p;
+       herefd = fd;
+       expandarg(arg, (struct arglist *)NULL, 0);
+       full_write(fd, stackblock(), expdest - (char *)stackblock());
 }
 
-
-void
-setstackmark(struct stackmark *mark)
+/*
+ * Returns true if the pattern matches the string.
+ */
+static int
+patmatch(char *pattern, const char *string)
 {
-       mark->stackp = stackp;
-       mark->stacknxt = stacknxt;
-       mark->stacknleft = stacknleft;
-       mark->marknext = markp;
-       markp = mark;
+       return pmatch(preglob(pattern, 0, 0), string);
 }
 
-
-void
-popstackmark(struct stackmark *mark)
+/*
+ * See if a pattern matches in a case statement.
+ */
+static int
+casematch(union node *pattern, char *val)
 {
-       struct stack_block *sp;
+       struct stackmark smark;
+       int result;
 
-       INTOFF;
-       markp = mark->marknext;
-       while (stackp != mark->stackp) {
-               sp = stackp;
-               stackp = sp->prev;
-               ckfree(sp);
-       }
-       stacknxt = mark->stacknxt;
-       stacknleft = mark->stacknleft;
-       sstrend = mark->stacknxt + mark->stacknleft;
-       INTON;
+       setstackmark(&smark);
+       argbackq = pattern->narg.backquote;
+       STARTSTACKSTR(expdest);
+       ifslastp = NULL;
+       argstr(pattern->narg.text, EXP_TILDE | EXP_CASE);
+       STACKSTRNUL(expdest);
+       result = patmatch(stackblock(), val);
+       popstackmark(&smark);
+       return result;
 }
 
 
-/*
- * When the parser reads in a string, it wants to stick the string on the
- * stack and only adjust the stack pointer when it knows how big the
- * string is.  Stackblock (defined in stack.h) returns a pointer to a block
- * of space on top of the stack and stackblocklen returns the length of
- * this block.  Growstackblock will grow this space by at least one byte,
- * possibly moving it (like realloc).  Grabstackblock actually allocates the
- * part of the block that has been used.
- */
-
-void
-growstackblock(void)
-{
-       size_t newlen;
+/* ============ find_command */
 
-       newlen = stacknleft * 2;
-       if (newlen < stacknleft)
-               sh_error(bb_msg_memory_exhausted);
-       if (newlen < 128)
-               newlen += 128;
+struct builtincmd {
+       const char *name;
+       int (*builtin)(int, char **);
+       /* unsigned flags; */
+};
+#define IS_BUILTIN_SPECIAL(b) ((b)->name[0] & 1)
+#define IS_BUILTIN_REGULAR(b) ((b)->name[0] & 2)
+#define IS_BUILTIN_ASSIGN(b) ((b)->name[0] & 4)
 
-       if (stacknxt == stackp->space && stackp != &stackbase) {
-               struct stack_block *oldstackp;
-               struct stackmark *xmark;
-               struct stack_block *sp;
-               struct stack_block *prevstackp;
-               size_t grosslen;
+struct cmdentry {
+       int cmdtype;
+       union param {
+               int index;
+               const struct builtincmd *cmd;
+               struct funcnode *func;
+       } u;
+};
+/* values of cmdtype */
+#define CMDUNKNOWN      -1      /* no entry in table for command */
+#define CMDNORMAL       0       /* command is an executable program */
+#define CMDFUNCTION     1       /* command is a shell function */
+#define CMDBUILTIN      2       /* command is a shell builtin */
 
-               INTOFF;
-               oldstackp = stackp;
-               sp = stackp;
-               prevstackp = sp->prev;
-               grosslen = newlen + sizeof(struct stack_block) - MINSIZE;
-               sp = ckrealloc((pointer)sp, grosslen);
-               sp->prev = prevstackp;
-               stackp = sp;
-               stacknxt = sp->space;
-               stacknleft = newlen;
-               sstrend = sp->space + newlen;
+/* action to find_command() */
+#define DO_ERR          0x01    /* prints errors */
+#define DO_ABS          0x02    /* checks absolute paths */
+#define DO_NOFUNC       0x04    /* don't return shell functions, for command */
+#define DO_ALTPATH      0x08    /* using alternate path */
+#define DO_ALTBLTIN     0x20    /* %builtin in alt. path */
 
-               /*
-                * Stack marks pointing to the start of the old block
-                * must be relocated to point to the new block
-                */
-               xmark = markp;
-               while (xmark != NULL && xmark->stackp == oldstackp) {
-                       xmark->stackp = stackp;
-                       xmark->stacknxt = stacknxt;
-                       xmark->stacknleft = stacknleft;
-                       xmark = xmark->marknext;
-               }
-               INTON;
-       } else {
-               char *oldspace = stacknxt;
-               int oldlen = stacknleft;
-               char *p = stalloc(newlen);
+static void find_command(char *, struct cmdentry *, int, const char *);
 
-               /* free the space we just allocated */
-               stacknxt = memcpy(p, oldspace, oldlen);
-               stacknleft += newlen;
-       }
-}
 
-static void grabstackblock(size_t len)
-{
-       len = SHELL_ALIGN(len);
-       stacknxt += len;
-       stacknleft -= len;
-}
+/* ============ Hashing commands */
 
 /*
- * The following routines are somewhat easier to use than the above.
- * The user declares a variable of type STACKSTR, which may be declared
- * to be a register.  The macro STARTSTACKSTR initializes things.  Then
- * the user uses the macro STPUTC to add characters to the string.  In
- * effect, STPUTC(c, p) is the same as *p++ = c except that the stack is
- * grown as necessary.  When the user is done, she can just leave the
- * string there and refer to it using stackblock().  Or she can allocate
- * the space for it using grabstackstr().  If it is necessary to allow
- * someone else to use the stack temporarily and then continue to grow
- * the string, the user should use grabstack to allocate the space, and
- * then call ungrabstr(p) to return to the previous mode of operation.
+ * When commands are first encountered, they are entered in a hash table.
+ * This ensures that a full path search will not have to be done for them
+ * on each invocation.
  *
- * USTPUTC is like STPUTC except that it doesn't check for overflow.
- * CHECKSTACKSPACE can be called before USTPUTC to ensure that there
- * is space for at least one character.
+ * We should investigate converting to a linear search, even though that
+ * would make the command name "hash" a misnomer.
  */
 
-void *
-growstackstr(void)
+#define CMDTABLESIZE 31         /* should be prime */
+#define ARB 1                   /* actual size determined at run time */
+
+struct tblentry {
+       struct tblentry *next;  /* next entry in hash chain */
+       union param param;      /* definition of builtin function */
+       short cmdtype;          /* index identifying command */
+       char rehash;            /* if set, cd done since entry created */
+       char cmdname[ARB];      /* name of command */
+};
+
+static struct tblentry *cmdtable[CMDTABLESIZE];
+static int builtinloc = -1;             /* index in path of %builtin, or -1 */
+
+static void
+tryexec(char *cmd, char **argv, char **envp)
 {
-       size_t len = stackblocksize();
-       if (herefd >= 0 && len >= 1024) {
-               full_write(herefd, stackblock(), len);
-               return stackblock();
+       int repeated = 0;
+
+#if ENABLE_FEATURE_SH_STANDALONE
+       if (strchr(cmd, '/') == NULL) {
+               const struct bb_applet *a;
+
+               a = find_applet_by_name(cmd);
+               if (a) {
+                       if (a->noexec)
+                               run_appletstruct_and_exit(a, argv);
+                       /* re-exec ourselves with the new arguments */
+                       execve(bb_busybox_exec_path, argv, envp);
+                       /* If they called chroot or otherwise made the binary no longer
+                        * executable, fall through */
+               }
+       }
+#endif
+
+ repeat:
+#ifdef SYSV
+       do {
+               execve(cmd, argv, envp);
+       } while (errno == EINTR);
+#else
+       execve(cmd, argv, envp);
+#endif
+       if (repeated++) {
+               free(argv);
+       } else if (errno == ENOEXEC) {
+               char **ap;
+               char **new;
+
+               for (ap = argv; *ap; ap++)
+                       ;
+               ap = new = ckmalloc((ap - argv + 2) * sizeof(char *));
+               ap[1] = cmd;
+               ap[0] = cmd = (char *)DEFAULT_SHELL;
+               ap += 2;
+               argv++;
+               while ((*ap++ = *argv++))
+                       ;
+               argv = new;
+               goto repeat;
        }
-       growstackblock();
-       return stackblock() + len;
 }
 
 /*
- * Called from CHECKSTRSPACE.
+ * Exec a program.  Never returns.  If you change this routine, you may
+ * have to change the find_command routine as well.
  */
-
-char *
-makestrspace(size_t newlen, char *p)
+#define environment() listvars(VEXPORT, VUNSET, 0)
+static void shellexec(char **, const char *, int) ATTRIBUTE_NORETURN;
+static void
+shellexec(char **argv, const char *path, int idx)
 {
-       size_t len = p - stacknxt;
-       size_t size = stackblocksize();
+       char *cmdname;
+       int e;
+       char **envp;
+       int exerrno;
 
-       for (;;) {
-               size_t nleft;
+       clearredir(1);
+       envp = environment();
+       if (strchr(argv[0], '/')
+#if ENABLE_FEATURE_SH_STANDALONE
+        || find_applet_by_name(argv[0])
+#endif
+       ) {
+               tryexec(argv[0], argv, envp);
+               e = errno;
+       } else {
+               e = ENOENT;
+               while ((cmdname = padvance(&path, argv[0])) != NULL) {
+                       if (--idx < 0 && pathopt == NULL) {
+                               tryexec(cmdname, argv, envp);
+                               if (errno != ENOENT && errno != ENOTDIR)
+                                       e = errno;
+                       }
+                       stunalloc(cmdname);
+               }
+       }
 
-               size = stackblocksize();
-               nleft = size - len;
-               if (nleft >= newlen)
-                       break;
-               growstackblock();
+       /* Map to POSIX errors */
+       switch (e) {
+       case EACCES:
+               exerrno = 126;
+               break;
+       case ENOENT:
+               exerrno = 127;
+               break;
+       default:
+               exerrno = 2;
+               break;
        }
-       return stackblock() + len;
+       exitstatus = exerrno;
+       TRACE(("shellexec failed for %s, errno %d, suppressint %d\n",
+               argv[0], e, suppressint ));
+       ash_msg_and_raise(EXEXEC, "%s: %s", argv[0], errmsg(e, "not found"));
+       /* NOTREACHED */
 }
 
-char *
-stnputs(const char *s, size_t n, char *p)
+static void
+printentry(struct tblentry *cmdp)
 {
-       p = makestrspace(n, p);
-       p = mempcpy(p, s, n);
-       return p;
-}
+       int idx;
+       const char *path;
+       char *name;
 
-char *
-stputs(const char *s, char *p)
-{
-       return stnputs(s, strlen(s), p);
+       idx = cmdp->param.index;
+       path = pathval();
+       do {
+               name = padvance(&path, cmdp->cmdname);
+               stunalloc(name);
+       } while (--idx >= 0);
+       out1fmt("%s%s\n", name, (cmdp->rehash ? "*" : nullstr));
 }
 
-/*      mystring.c   */
-
 /*
- * String functions.
- *
- *      number(s)               Convert a string of digits to an integer.
- *      is_number(s)            Return true if s is a string of digits.
- */
-
-/*
- * prefix -- see if pfx is a prefix of string.
+ * Clear out command entries.  The argument specifies the first entry in
+ * PATH which has changed.
  */
-
-char *
-prefix(const char *string, const char *pfx)
+static void
+clearcmdentry(int firstchange)
 {
-       while (*pfx) {
-               if (*pfx++ != *string++)
-                       return 0;
+       struct tblentry **tblp;
+       struct tblentry **pp;
+       struct tblentry *cmdp;
+
+       INT_OFF;
+       for (tblp = cmdtable; tblp < &cmdtable[CMDTABLESIZE]; tblp++) {
+               pp = tblp;
+               while ((cmdp = *pp) != NULL) {
+                       if ((cmdp->cmdtype == CMDNORMAL &&
+                            cmdp->param.index >= firstchange)
+                        || (cmdp->cmdtype == CMDBUILTIN &&
+                            builtinloc >= firstchange)
+                       ) {
+                               *pp = cmdp->next;
+                               free(cmdp);
+                       } else {
+                               pp = &cmdp->next;
+                       }
+               }
        }
-       return (char *) string;
+       INT_ON;
 }
 
-
 /*
- * Convert a string of digits to an integer, printing an error message on
- * failure.
+ * Locate a command in the command hash table.  If "add" is nonzero,
+ * add the command to the table if it is not already present.  The
+ * variable "lastcmdentry" is set to point to the address of the link
+ * pointing to the entry, so that delete_cmd_entry can delete the
+ * entry.
+ *
+ * Interrupts must be off if called with add != 0.
  */
+static struct tblentry **lastcmdentry;
 
-int
-number(const char *s)
+static struct tblentry *
+cmdlookup(const char *name, int add)
 {
+       unsigned int hashval;
+       const char *p;
+       struct tblentry *cmdp;
+       struct tblentry **pp;
 
-       if (! is_number(s))
-               sh_error(illnum, s);
-       return atoi(s);
+       p = name;
+       hashval = (unsigned char)*p << 4;
+       while (*p)
+               hashval += (unsigned char)*p++;
+       hashval &= 0x7FFF;
+       pp = &cmdtable[hashval % CMDTABLESIZE];
+       for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
+               if (strcmp(cmdp->cmdname, name) == 0)
+                       break;
+               pp = &cmdp->next;
+       }
+       if (add && cmdp == NULL) {
+               cmdp = *pp = ckmalloc(sizeof(struct tblentry) - ARB
+                                       + strlen(name) + 1);
+               cmdp->next = NULL;
+               cmdp->cmdtype = CMDUNKNOWN;
+               strcpy(cmdp->cmdname, name);
+       }
+       lastcmdentry = pp;
+       return cmdp;
 }
 
-
 /*
- * Check for a valid number.  This should be elsewhere.
+ * Delete the command entry returned on the last lookup.
  */
-
-int
-is_number(const char *p)
+static void
+delete_cmd_entry(void)
 {
-       do {
-               if (! is_digit(*p))
-                       return 0;
-       } while (*++p != '\0');
-       return 1;
-}
+       struct tblentry *cmdp;
 
+       INT_OFF;
+       cmdp = *lastcmdentry;
+       *lastcmdentry = cmdp->next;
+       if (cmdp->cmdtype == CMDFUNCTION)
+               freefunc(cmdp->param.func);
+       free(cmdp);
+       INT_ON;
+}
 
 /*
- * Produce a possibly single quoted string suitable as input to the shell.
- * The return string is allocated on the stack.
+ * Add a new command entry, replacing any existing command entry for
+ * the same name - except special builtins.
  */
+static void
+addcmdentry(char *name, struct cmdentry *entry)
+{
+       struct tblentry *cmdp;
 
-char *
-single_quote(const char *s) {
-       char *p;
-
-       STARTSTACKSTR(p);
-
-       do {
-               char *q;
-               size_t len;
-
-               len = strchrnul(s, '\'') - s;
-
-               q = p = makestrspace(len + 3, p);
-
-               *q++ = '\'';
-               q = mempcpy(q, s, len);
-               *q++ = '\'';
-               s += len;
-
-               STADJUST(q - p, p);
-
-               len = strspn(s, "'");
-               if (!len)
-                       break;
-
-               q = p = makestrspace(len + 3, p);
-
-               *q++ = '"';
-               q = mempcpy(q, s, len);
-               *q++ = '"';
-               s += len;
-
-               STADJUST(q - p, p);
-       } while (*s);
+       cmdp = cmdlookup(name, 1);
+       if (cmdp->cmdtype == CMDFUNCTION) {
+               freefunc(cmdp->param.func);
+       }
+       cmdp->cmdtype = entry->cmdtype;
+       cmdp->param = entry->u;
+       cmdp->rehash = 0;
+}
 
-       USTPUTC(0, p);
+static int
+hashcmd(int argc, char **argv)
+{
+       struct tblentry **pp;
+       struct tblentry *cmdp;
+       int c;
+       struct cmdentry entry;
+       char *name;
 
-       return stackblock();
+       while ((c = nextopt("r")) != '\0') {
+               clearcmdentry(0);
+               return 0;
+       }
+       if (*argptr == NULL) {
+               for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
+                       for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
+                               if (cmdp->cmdtype == CMDNORMAL)
+                                       printentry(cmdp);
+                       }
+               }
+               return 0;
+       }
+       c = 0;
+       while ((name = *argptr) != NULL) {
+               cmdp = cmdlookup(name, 0);
+               if (cmdp != NULL
+                && (cmdp->cmdtype == CMDNORMAL
+                    || (cmdp->cmdtype == CMDBUILTIN && builtinloc >= 0)))
+                       delete_cmd_entry();
+               find_command(name, &entry, DO_ERR, pathval());
+               if (entry.cmdtype == CMDUNKNOWN)
+                       c = 1;
+               argptr++;
+       }
+       return c;
 }
 
 /*
- * Like strdup but works with the ash stack.
+ * Called when a cd is done.  Marks all commands so the next time they
+ * are executed they will be rehashed.
  */
-
-char *
-sstrdup(const char *p)
-{
-       size_t len = strlen(p) + 1;
-       return memcpy(stalloc(len), p, len);
-}
-
-
 static void
-calcsize(union node *n)
+hashcd(void)
 {
-      if (n == NULL)
-           return;
-      funcblocksize += nodesize[n->type];
-      switch (n->type) {
-      case NCMD:
-           calcsize(n->ncmd.redirect);
-           calcsize(n->ncmd.args);
-           calcsize(n->ncmd.assign);
-           break;
-      case NPIPE:
-           sizenodelist(n->npipe.cmdlist);
-           break;
-      case NREDIR:
-      case NBACKGND:
-      case NSUBSHELL:
-           calcsize(n->nredir.redirect);
-           calcsize(n->nredir.n);
-           break;
-      case NAND:
-      case NOR:
-      case NSEMI:
-      case NWHILE:
-      case NUNTIL:
-           calcsize(n->nbinary.ch2);
-           calcsize(n->nbinary.ch1);
-           break;
-      case NIF:
-           calcsize(n->nif.elsepart);
-           calcsize(n->nif.ifpart);
-           calcsize(n->nif.test);
-           break;
-      case NFOR:
-           funcstringsize += strlen(n->nfor.var) + 1;
-           calcsize(n->nfor.body);
-           calcsize(n->nfor.args);
-           break;
-      case NCASE:
-           calcsize(n->ncase.cases);
-           calcsize(n->ncase.expr);
-           break;
-      case NCLIST:
-           calcsize(n->nclist.body);
-           calcsize(n->nclist.pattern);
-           calcsize(n->nclist.next);
-           break;
-      case NDEFUN:
-      case NARG:
-           sizenodelist(n->narg.backquote);
-           funcstringsize += strlen(n->narg.text) + 1;
-           calcsize(n->narg.next);
-           break;
-      case NTO:
-      case NCLOBBER:
-      case NFROM:
-      case NFROMTO:
-      case NAPPEND:
-           calcsize(n->nfile.fname);
-           calcsize(n->nfile.next);
-           break;
-      case NTOFD:
-      case NFROMFD:
-           calcsize(n->ndup.vname);
-           calcsize(n->ndup.next);
-           break;
-      case NHERE:
-      case NXHERE:
-           calcsize(n->nhere.doc);
-           calcsize(n->nhere.next);
-           break;
-      case NNOT:
-           calcsize(n->nnot.com);
-           break;
-      };
-}
-
+       struct tblentry **pp;
+       struct tblentry *cmdp;
 
-static void
-sizenodelist(struct nodelist *lp)
-{
-       while (lp) {
-               funcblocksize += SHELL_ALIGN(sizeof(struct nodelist));
-               calcsize(lp->n);
-               lp = lp->next;
+       for (pp = cmdtable; pp < &cmdtable[CMDTABLESIZE]; pp++) {
+               for (cmdp = *pp; cmdp; cmdp = cmdp->next) {
+                       if (cmdp->cmdtype == CMDNORMAL || (
+                               cmdp->cmdtype == CMDBUILTIN &&
+                               !(IS_BUILTIN_REGULAR(cmdp->param.cmd)) &&
+                               builtinloc > 0
+                       ))
+                               cmdp->rehash = 1;
+               }
        }
 }
 
-
-static union node *
-copynode(union node *n)
+/*
+ * Fix command hash table when PATH changed.
+ * Called before PATH is changed.  The argument is the new value of PATH;
+ * pathval() still returns the old value at this point.
+ * Called with interrupts off.
+ */
+static void
+changepath(const char *newval)
 {
-      union node *new;
-
-      if (n == NULL)
-           return NULL;
-      new = funcblock;
-      funcblock = (char *) funcblock + nodesize[n->type];
-      switch (n->type) {
-      case NCMD:
-           new->ncmd.redirect = copynode(n->ncmd.redirect);
-           new->ncmd.args = copynode(n->ncmd.args);
-           new->ncmd.assign = copynode(n->ncmd.assign);
-           break;
-      case NPIPE:
-           new->npipe.cmdlist = copynodelist(n->npipe.cmdlist);
-           new->npipe.backgnd = n->npipe.backgnd;
-           break;
-      case NREDIR:
-      case NBACKGND:
-      case NSUBSHELL:
-           new->nredir.redirect = copynode(n->nredir.redirect);
-           new->nredir.n = copynode(n->nredir.n);
-           break;
-      case NAND:
-      case NOR:
-      case NSEMI:
-      case NWHILE:
-      case NUNTIL:
-           new->nbinary.ch2 = copynode(n->nbinary.ch2);
-           new->nbinary.ch1 = copynode(n->nbinary.ch1);
-           break;
-      case NIF:
-           new->nif.elsepart = copynode(n->nif.elsepart);
-           new->nif.ifpart = copynode(n->nif.ifpart);
-           new->nif.test = copynode(n->nif.test);
-           break;
-      case NFOR:
-           new->nfor.var = nodesavestr(n->nfor.var);
-           new->nfor.body = copynode(n->nfor.body);
-           new->nfor.args = copynode(n->nfor.args);
-           break;
-      case NCASE:
-           new->ncase.cases = copynode(n->ncase.cases);
-           new->ncase.expr = copynode(n->ncase.expr);
-           break;
-      case NCLIST:
-           new->nclist.body = copynode(n->nclist.body);
-           new->nclist.pattern = copynode(n->nclist.pattern);
-           new->nclist.next = copynode(n->nclist.next);
-           break;
-      case NDEFUN:
-      case NARG:
-           new->narg.backquote = copynodelist(n->narg.backquote);
-           new->narg.text = nodesavestr(n->narg.text);
-           new->narg.next = copynode(n->narg.next);
-           break;
-      case NTO:
-      case NCLOBBER:
-      case NFROM:
-      case NFROMTO:
-      case NAPPEND:
-           new->nfile.fname = copynode(n->nfile.fname);
-           new->nfile.fd = n->nfile.fd;
-           new->nfile.next = copynode(n->nfile.next);
-           break;
-      case NTOFD:
-      case NFROMFD:
-           new->ndup.vname = copynode(n->ndup.vname);
-           new->ndup.dupfd = n->ndup.dupfd;
-           new->ndup.fd = n->ndup.fd;
-           new->ndup.next = copynode(n->ndup.next);
-           break;
-      case NHERE:
-      case NXHERE:
-           new->nhere.doc = copynode(n->nhere.doc);
-           new->nhere.fd = n->nhere.fd;
-           new->nhere.next = copynode(n->nhere.next);
-           break;
-      case NNOT:
-           new->nnot.com = copynode(n->nnot.com);
-           break;
-      };
-      new->type = n->type;
-       return new;
+       const char *old, *new;
+       int idx;
+       int firstchange;
+       int idx_bltin;
+
+       old = pathval();
+       new = newval;
+       firstchange = 9999;     /* assume no change */
+       idx = 0;
+       idx_bltin = -1;
+       for (;;) {
+               if (*old != *new) {
+                       firstchange = idx;
+                       if ((*old == '\0' && *new == ':')
+                        || (*old == ':' && *new == '\0'))
+                               firstchange++;
+                       old = new;      /* ignore subsequent differences */
+               }
+               if (*new == '\0')
+                       break;
+               if (*new == '%' && idx_bltin < 0 && prefix(new + 1, "builtin"))
+                       idx_bltin = idx;
+               if (*new == ':') {
+                       idx++;
+               }
+               new++, old++;
+       }
+       if (builtinloc < 0 && idx_bltin >= 0)
+               builtinloc = idx_bltin;             /* zap builtins */
+       if (builtinloc >= 0 && idx_bltin < 0)
+               firstchange = 0;
+       clearcmdentry(firstchange);
+       builtinloc = idx_bltin;
 }
 
+#define TEOF 0
+#define TNL 1
+#define TREDIR 2
+#define TWORD 3
+#define TSEMI 4
+#define TBACKGND 5
+#define TAND 6
+#define TOR 7
+#define TPIPE 8
+#define TLP 9
+#define TRP 10
+#define TENDCASE 11
+#define TENDBQUOTE 12
+#define TNOT 13
+#define TCASE 14
+#define TDO 15
+#define TDONE 16
+#define TELIF 17
+#define TELSE 18
+#define TESAC 19
+#define TFI 20
+#define TFOR 21
+#define TIF 22
+#define TIN 23
+#define TTHEN 24
+#define TUNTIL 25
+#define TWHILE 26
+#define TBEGIN 27
+#define TEND 28
 
-static struct nodelist *
-copynodelist(struct nodelist *lp)
+/* first char is indicating which tokens mark the end of a list */
+static const char *const tokname_array[] = {
+       "\1end of file",
+       "\0newline",
+       "\0redirection",
+       "\0word",
+       "\0;",
+       "\0&",
+       "\0&&",
+       "\0||",
+       "\0|",
+       "\0(",
+       "\1)",
+       "\1;;",
+       "\1`",
+#define KWDOFFSET 13
+       /* the following are keywords */
+       "\0!",
+       "\0case",
+       "\1do",
+       "\1done",
+       "\1elif",
+       "\1else",
+       "\1esac",
+       "\1fi",
+       "\0for",
+       "\0if",
+       "\0in",
+       "\1then",
+       "\0until",
+       "\0while",
+       "\0{",
+       "\1}",
+};
+
+static const char *
+tokname(int tok)
 {
-       struct nodelist *start;
-       struct nodelist **lpp;
+       static char buf[16];
 
-       lpp = &start;
-       while (lp) {
-               *lpp = funcblock;
-               funcblock = (char *) funcblock +
-                   SHELL_ALIGN(sizeof(struct nodelist));
-               (*lpp)->n = copynode(lp->n);
-               lp = lp->next;
-               lpp = &(*lpp)->next;
-       }
-       *lpp = NULL;
-       return start;
-}
+//try this:
+//if (tok < TSEMI) return tokname_array[tok] + 1;
+//sprintf(buf, "\"%s\"", tokname_array[tok] + 1);
+//return buf;
 
+       if (tok >= TSEMI)
+               buf[0] = '"';
+       sprintf(buf + (tok >= TSEMI), "%s%c",
+                       tokname_array[tok] + 1, (tok >= TSEMI ? '"' : 0));
+       return buf;
+}
 
-static char *
-nodesavestr(char   *s)
+/* Wrapper around strcmp for qsort/bsearch/... */
+static int
+pstrcmp(const void *a, const void *b)
 {
-       char   *rtn = funcstring;
-
-       funcstring = stpcpy(funcstring, s) + 1;
-       return rtn;
+       return strcmp((char*) a, (*(char**) b) + 1);
 }
 
-
-/*
- * Free a parse tree.
- */
-
-static void
-freefunc(struct funcnode *f)
+static const char *const *
+findkwd(const char *s)
 {
-       if (f && --f->count < 0)
-               ckfree(f);
+       return bsearch(s, tokname_array + KWDOFFSET,
+                       ARRAY_SIZE(tokname_array) - KWDOFFSET,
+                       sizeof(tokname_array[0]), pstrcmp);
 }
 
-
-static void options(int);
-static void setoption(int, int);
-
-
 /*
- * Process the shell command line arguments.
+ * Locate and print what a word is...
  */
-
-void
-procargs(int argc, char **argv)
+static int
+describe_command(char *command, int describe_command_verbose)
 {
-       int i;
-       const char *xminusc;
-       char **xargv;
-
-       xargv = argv;
-       arg0 = xargv[0];
-       if (argc > 0)
-               xargv++;
-       for (i = 0; i < NOPTS; i++)
-               optlist[i] = 2;
-       argptr = xargv;
-       options(1);
-       xargv = argptr;
-       xminusc = minusc;
-       if (*xargv == NULL) {
-               if (xminusc)
-                       sh_error(bb_msg_requires_arg, "-c");
-               sflag = 1;
-       }
-       if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
-               iflag = 1;
-       if (mflag == 2)
-               mflag = iflag;
-       for (i = 0; i < NOPTS; i++)
-               if (optlist[i] == 2)
-                       optlist[i] = 0;
-#if DEBUG == 2
-       debug = 1;
+       struct cmdentry entry;
+       struct tblentry *cmdp;
+#if ENABLE_ASH_ALIAS
+       const struct alias *ap;
 #endif
-       /* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
-       if (xminusc) {
-               minusc = *xargv++;
-               if (*xargv)
-                       goto setarg0;
-       } else if (!sflag) {
-               setinputfile(*xargv, 0);
-setarg0:
-               arg0 = *xargv++;
-               commandname = arg0;
-       }
+       const char *path = pathval();
 
-       shellparam.p = xargv;
-#ifdef CONFIG_ASH_GETOPTS
-       shellparam.optind = 1;
-       shellparam.optoff = -1;
-#endif
-       /* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
-       while (*xargv) {
-               shellparam.nparam++;
-               xargv++;
+       if (describe_command_verbose) {
+               out1str(command);
        }
-       optschanged();
-}
 
+       /* First look at the keywords */
+       if (findkwd(command)) {
+               out1str(describe_command_verbose ? " is a shell keyword" : command);
+               goto out;
+       }
 
-void
-optschanged(void)
-{
-#if DEBUG
-       opentrace();
+#if ENABLE_ASH_ALIAS
+       /* Then look at the aliases */
+       ap = lookupalias(command, 0);
+       if (ap != NULL) {
+               if (!describe_command_verbose) {
+                       out1str("alias ");
+                       printalias(ap);
+                       return 0;
+               }
+               out1fmt(" is an alias for %s", ap->val);
+               goto out;
+       }
 #endif
-       setinteractive(iflag);
-       setjobctl(mflag);
-       setvimode(viflag);
-}
-
-static void minus_o(char *name, int val)
-{
-       int i;
-
-       if (name == NULL) {
-               out1str("Current option settings\n");
-               for (i = 0; i < NOPTS; i++)
-                       out1fmt("%-16s%s\n", optnames(i),
-                               optlist[i] ? "on" : "off");
+       /* Then check if it is a tracked alias */
+       cmdp = cmdlookup(command, 0);
+       if (cmdp != NULL) {
+               entry.cmdtype = cmdp->cmdtype;
+               entry.u = cmdp->param;
        } else {
-               for (i = 0; i < NOPTS; i++)
-                       if (equal(name, optnames(i))) {
-                               optlist[i] = val;
-                               return;
-                       }
-               sh_error("Illegal option -o %s", name);
+               /* Finally use brute force */
+               find_command(command, &entry, DO_ABS, path);
        }
-}
 
-/*
- * Process shell options.  The global variable argptr contains a pointer
- * to the argument list; we advance it past the options.
- */
+       switch (entry.cmdtype) {
+       case CMDNORMAL: {
+               int j = entry.u.index;
+               char *p;
+               if (j == -1) {
+                       p = command;
+               } else {
+                       do {
+                               p = padvance(&path, command);
+                               stunalloc(p);
+                       } while (--j >= 0);
+               }
+               if (describe_command_verbose) {
+                       out1fmt(" is%s %s",
+                               (cmdp ? " a tracked alias for" : nullstr), p
+                       );
+               } else {
+                       out1str(p);
+               }
+               break;
+       }
 
-static void
-options(int cmdline)
-{
-       char *p;
-       int val;
-       int c;
+       case CMDFUNCTION:
+               if (describe_command_verbose) {
+                       out1str(" is a shell function");
+               } else {
+                       out1str(command);
+               }
+               break;
 
-       if (cmdline)
-               minusc = NULL;
-       while ((p = *argptr) != NULL) {
-               argptr++;
-               if ((c = *p++) == '-') {
-                       val = 1;
-                       if (p[0] == '\0' || (p[0] == '-' && p[1] == '\0')) {
-                               if (!cmdline) {
-                                       /* "-" means turn off -x and -v */
-                                       if (p[0] == '\0')
-                                               xflag = vflag = 0;
-                                       /* "--" means reset params */
-                                       else if (*argptr == NULL)
-                                               setparam(argptr);
-                               }
-                               break;    /* "-" or  "--" terminates options */
-                       }
-               } else if (c == '+') {
-                       val = 0;
+       case CMDBUILTIN:
+               if (describe_command_verbose) {
+                       out1fmt(" is a %sshell builtin",
+                               IS_BUILTIN_SPECIAL(entry.u.cmd) ?
+                                       "special " : nullstr
+                       );
                } else {
-                       argptr--;
-                       break;
+                       out1str(command);
                }
-               while ((c = *p++) != '\0') {
-                       if (c == 'c' && cmdline) {
-                               minusc = p;     /* command is after shell args*/
-                       } else if (c == 'o') {
-                               minus_o(*argptr, val);
-                               if (*argptr)
-                                       argptr++;
-                       } else if (cmdline && (c == '-')) {     // long options
-                               if (strcmp(p, "login") == 0)
-                                       isloginsh = 1;
-                               break;
-                       } else {
-                               setoption(c, val);
-                       }
+               break;
+
+       default:
+               if (describe_command_verbose) {
+                       out1str(": not found\n");
                }
+               return 127;
        }
+ out:
+       outstr("\n", stdout);
+       return 0;
 }
 
-
-static void
-setoption(int flag, int val)
+static int
+typecmd(int argc, char **argv)
 {
-       int i;
+       int i = 1;
+       int err = 0;
+       int verbose = 1;
 
-       for (i = 0; i < NOPTS; i++)
-               if (optletters(i) == flag) {
-                       optlist[i] = val;
-                       return;
-               }
-       sh_error("Illegal option -%c", flag);
-       /* NOTREACHED */
+       /* type -p ... ? (we don't bother checking for 'p') */
+       if (argv[1] && argv[1][0] == '-') {
+               i++;
+               verbose = 0;
+       }
+       while (i < argc) {
+               err |= describe_command(argv[i++], verbose);
+       }
+       return err;
 }
 
-
-
-/*
- * Set the shell parameters.
- */
-
-void
-setparam(char **argv)
+#if ENABLE_ASH_CMDCMD
+static int
+commandcmd(int argc, char **argv)
 {
-       char **newparam;
-       char **ap;
-       int nparam;
+       int c;
+       enum {
+               VERIFY_BRIEF = 1,
+               VERIFY_VERBOSE = 2,
+       } verify = 0;
 
-       for (nparam = 0 ; argv[nparam] ; nparam++);
-       ap = newparam = ckmalloc((nparam + 1) * sizeof *ap);
-       while (*argv) {
-               *ap++ = savestr(*argv++);
-       }
-       *ap = NULL;
-       freeparam(&shellparam);
-       shellparam.malloc = 1;
-       shellparam.nparam = nparam;
-       shellparam.p = newparam;
-#ifdef CONFIG_ASH_GETOPTS
-       shellparam.optind = 1;
-       shellparam.optoff = -1;
+       while ((c = nextopt("pvV")) != '\0')
+               if (c == 'V')
+                       verify |= VERIFY_VERBOSE;
+               else if (c == 'v')
+                       verify |= VERIFY_BRIEF;
+#if DEBUG
+               else if (c != 'p')
+                       abort();
 #endif
+       if (verify)
+               return describe_command(*argptr, verify - VERIFY_BRIEF);
+
+       return 0;
 }
+#endif
 
 
-/*
- * Free the list of positional parameters.
- */
+/* ============ eval.c */
 
-void
-freeparam(volatile struct shparam *param)
-{
-       char **ap;
+static int funcblocksize;          /* size of structures in function */
+static int funcstringsize;         /* size of strings in node */
+static void *funcblock;            /* block to allocate function from */
+static char *funcstring;           /* block to allocate strings from */
 
-       if (param->malloc) {
-               for (ap = param->p ; *ap ; ap++)
-                       ckfree(*ap);
-               ckfree(param->p);
+/* flags in argument to evaltree */
+#define EV_EXIT 01              /* exit after evaluating tree */
+#define EV_TESTED 02            /* exit status is checked; ignore -e flag */
+#define EV_BACKCMD 04           /* command executing within back quotes */
+
+static const short nodesize[26] = {
+       SHELL_ALIGN(sizeof(struct ncmd)),
+       SHELL_ALIGN(sizeof(struct npipe)),
+       SHELL_ALIGN(sizeof(struct nredir)),
+       SHELL_ALIGN(sizeof(struct nredir)),
+       SHELL_ALIGN(sizeof(struct nredir)),
+       SHELL_ALIGN(sizeof(struct nbinary)),
+       SHELL_ALIGN(sizeof(struct nbinary)),
+       SHELL_ALIGN(sizeof(struct nbinary)),
+       SHELL_ALIGN(sizeof(struct nif)),
+       SHELL_ALIGN(sizeof(struct nbinary)),
+       SHELL_ALIGN(sizeof(struct nbinary)),
+       SHELL_ALIGN(sizeof(struct nfor)),
+       SHELL_ALIGN(sizeof(struct ncase)),
+       SHELL_ALIGN(sizeof(struct nclist)),
+       SHELL_ALIGN(sizeof(struct narg)),
+       SHELL_ALIGN(sizeof(struct narg)),
+       SHELL_ALIGN(sizeof(struct nfile)),
+       SHELL_ALIGN(sizeof(struct nfile)),
+       SHELL_ALIGN(sizeof(struct nfile)),
+       SHELL_ALIGN(sizeof(struct nfile)),
+       SHELL_ALIGN(sizeof(struct nfile)),
+       SHELL_ALIGN(sizeof(struct ndup)),
+       SHELL_ALIGN(sizeof(struct ndup)),
+       SHELL_ALIGN(sizeof(struct nhere)),
+       SHELL_ALIGN(sizeof(struct nhere)),
+       SHELL_ALIGN(sizeof(struct nnot)),
+};
+
+static void calcsize(union node *n);
+
+static void
+sizenodelist(struct nodelist *lp)
+{
+       while (lp) {
+               funcblocksize += SHELL_ALIGN(sizeof(struct nodelist));
+               calcsize(lp->n);
+               lp = lp->next;
        }
 }
 
+static void
+calcsize(union node *n)
+{
+       if (n == NULL)
+               return;
+       funcblocksize += nodesize[n->type];
+       switch (n->type) {
+       case NCMD:
+               calcsize(n->ncmd.redirect);
+               calcsize(n->ncmd.args);
+               calcsize(n->ncmd.assign);
+               break;
+       case NPIPE:
+               sizenodelist(n->npipe.cmdlist);
+               break;
+       case NREDIR:
+       case NBACKGND:
+       case NSUBSHELL:
+               calcsize(n->nredir.redirect);
+               calcsize(n->nredir.n);
+               break;
+       case NAND:
+       case NOR:
+       case NSEMI:
+       case NWHILE:
+       case NUNTIL:
+               calcsize(n->nbinary.ch2);
+               calcsize(n->nbinary.ch1);
+               break;
+       case NIF:
+               calcsize(n->nif.elsepart);
+               calcsize(n->nif.ifpart);
+               calcsize(n->nif.test);
+               break;
+       case NFOR:
+               funcstringsize += strlen(n->nfor.var) + 1;
+               calcsize(n->nfor.body);
+               calcsize(n->nfor.args);
+               break;
+       case NCASE:
+               calcsize(n->ncase.cases);
+               calcsize(n->ncase.expr);
+               break;
+       case NCLIST:
+               calcsize(n->nclist.body);
+               calcsize(n->nclist.pattern);
+               calcsize(n->nclist.next);
+               break;
+       case NDEFUN:
+       case NARG:
+               sizenodelist(n->narg.backquote);
+               funcstringsize += strlen(n->narg.text) + 1;
+               calcsize(n->narg.next);
+               break;
+       case NTO:
+       case NCLOBBER:
+       case NFROM:
+       case NFROMTO:
+       case NAPPEND:
+               calcsize(n->nfile.fname);
+               calcsize(n->nfile.next);
+               break;
+       case NTOFD:
+       case NFROMFD:
+               calcsize(n->ndup.vname);
+               calcsize(n->ndup.next);
+       break;
+       case NHERE:
+       case NXHERE:
+               calcsize(n->nhere.doc);
+               calcsize(n->nhere.next);
+               break;
+       case NNOT:
+               calcsize(n->nnot.com);
+               break;
+       };
+}
+
+static char *
+nodeckstrdup(char *s)
+{
+       char *rtn = funcstring;
 
+       strcpy(funcstring, s);
+       funcstring += strlen(s) + 1;
+       return rtn;
+}
 
-/*
- * The shift builtin command.
- */
+static union node *copynode(union node *);
 
-int
-shiftcmd(int argc, char **argv)
+static struct nodelist *
+copynodelist(struct nodelist *lp)
 {
-       int n;
-       char **ap1, **ap2;
+       struct nodelist *start;
+       struct nodelist **lpp;
 
-       n = 1;
-       if (argc > 1)
-               n = number(argv[1]);
-       if (n > shellparam.nparam)
-               sh_error("can't shift that many");
-       INTOFF;
-       shellparam.nparam -= n;
-       for (ap1 = shellparam.p ; --n >= 0 ; ap1++) {
-               if (shellparam.malloc)
-                       ckfree(*ap1);
+       lpp = &start;
+       while (lp) {
+               *lpp = funcblock;
+               funcblock = (char *) funcblock + SHELL_ALIGN(sizeof(struct nodelist));
+               (*lpp)->n = copynode(lp->n);
+               lp = lp->next;
+               lpp = &(*lpp)->next;
        }
-       ap2 = shellparam.p;
-       while ((*ap2++ = *ap1++) != NULL);
-#ifdef CONFIG_ASH_GETOPTS
-       shellparam.optind = 1;
-       shellparam.optoff = -1;
-#endif
-       INTON;
-       return 0;
+       *lpp = NULL;
+       return start;
 }
 
+static union node *
+copynode(union node *n)
+{
+       union node *new;
+
+       if (n == NULL)
+               return NULL;
+       new = funcblock;
+       funcblock = (char *) funcblock + nodesize[n->type];
 
+       switch (n->type) {
+       case NCMD:
+               new->ncmd.redirect = copynode(n->ncmd.redirect);
+               new->ncmd.args = copynode(n->ncmd.args);
+               new->ncmd.assign = copynode(n->ncmd.assign);
+               break;
+       case NPIPE:
+               new->npipe.cmdlist = copynodelist(n->npipe.cmdlist);
+               new->npipe.backgnd = n->npipe.backgnd;
+               break;
+       case NREDIR:
+       case NBACKGND:
+       case NSUBSHELL:
+               new->nredir.redirect = copynode(n->nredir.redirect);
+               new->nredir.n = copynode(n->nredir.n);
+               break;
+       case NAND:
+       case NOR:
+       case NSEMI:
+       case NWHILE:
+       case NUNTIL:
+               new->nbinary.ch2 = copynode(n->nbinary.ch2);
+               new->nbinary.ch1 = copynode(n->nbinary.ch1);
+               break;
+       case NIF:
+               new->nif.elsepart = copynode(n->nif.elsepart);
+               new->nif.ifpart = copynode(n->nif.ifpart);
+               new->nif.test = copynode(n->nif.test);
+               break;
+       case NFOR:
+               new->nfor.var = nodeckstrdup(n->nfor.var);
+               new->nfor.body = copynode(n->nfor.body);
+               new->nfor.args = copynode(n->nfor.args);
+               break;
+       case NCASE:
+               new->ncase.cases = copynode(n->ncase.cases);
+               new->ncase.expr = copynode(n->ncase.expr);
+               break;
+       case NCLIST:
+               new->nclist.body = copynode(n->nclist.body);
+               new->nclist.pattern = copynode(n->nclist.pattern);
+               new->nclist.next = copynode(n->nclist.next);
+               break;
+       case NDEFUN:
+       case NARG:
+               new->narg.backquote = copynodelist(n->narg.backquote);
+               new->narg.text = nodeckstrdup(n->narg.text);
+               new->narg.next = copynode(n->narg.next);
+               break;
+       case NTO:
+       case NCLOBBER:
+       case NFROM:
+       case NFROMTO:
+       case NAPPEND:
+               new->nfile.fname = copynode(n->nfile.fname);
+               new->nfile.fd = n->nfile.fd;
+               new->nfile.next = copynode(n->nfile.next);
+               break;
+       case NTOFD:
+       case NFROMFD:
+               new->ndup.vname = copynode(n->ndup.vname);
+               new->ndup.dupfd = n->ndup.dupfd;
+               new->ndup.fd = n->ndup.fd;
+               new->ndup.next = copynode(n->ndup.next);
+               break;
+       case NHERE:
+       case NXHERE:
+               new->nhere.doc = copynode(n->nhere.doc);
+               new->nhere.fd = n->nhere.fd;
+               new->nhere.next = copynode(n->nhere.next);
+               break;
+       case NNOT:
+               new->nnot.com = copynode(n->nnot.com);
+               break;
+       };
+       new->type = n->type;
+       return new;
+}
 
 /*
- * The set command builtin.
+ * Make a copy of a parse tree.
  */
-
-int
-setcmd(int argc, char **argv)
+static struct funcnode *
+copyfunc(union node *n)
 {
-       if (argc == 1)
-               return showvars(nullstr, 0, VUNSET);
-       INTOFF;
-       options(0);
-       optschanged();
-       if (*argptr != NULL) {
-               setparam(argptr);
-       }
-       INTON;
-       return 0;
+       struct funcnode *f;
+       size_t blocksize;
+
+       funcblocksize = offsetof(struct funcnode, n);
+       funcstringsize = 0;
+       calcsize(n);
+       blocksize = funcblocksize;
+       f = ckmalloc(blocksize + funcstringsize);
+       funcblock = (char *) f + offsetof(struct funcnode, n);
+       funcstring = (char *) f + blocksize;
+       copynode(n);
+       f->count = 0;
+       return f;
 }
 
-
-#ifdef CONFIG_ASH_GETOPTS
+/*
+ * Define a shell function.
+ */
 static void
-getoptsreset(const char *value)
-{
-       shellparam.optind = number(value);
-       shellparam.optoff = -1;
-}
-#endif
-
-#ifdef CONFIG_LOCALE_SUPPORT
-static void change_lc_all(const char *value)
+defun(char *name, union node *func)
 {
-       if (value != 0 && *value != 0)
-               setlocale(LC_ALL, value);
-}
+       struct cmdentry entry;
 
-static void change_lc_ctype(const char *value)
-{
-       if (value != 0 && *value != 0)
-               setlocale(LC_CTYPE, value);
+       INT_OFF;
+       entry.cmdtype = CMDFUNCTION;
+       entry.u.func = copyfunc(func);
+       addcmdentry(name, &entry);
+       INT_ON;
 }
 
-#endif
-
-#ifdef CONFIG_ASH_RANDOM_SUPPORT
-/* Roughly copied from bash.. */
-static void change_random(const char *value)
-{
-       if(value == NULL) {
-               /* "get", generate */
-               char buf[16];
-
-               rseed = rseed * 1103515245 + 12345;
-               sprintf(buf, "%d", (unsigned int)((rseed & 32767)));
-               /* set without recursion */
-               setvar(vrandom.text, buf, VNOFUNC);
-               vrandom.flags &= ~VNOFUNC;
-       } else {
-               /* set/reset */
-               rseed = strtoul(value, (char **)NULL, 10);
-       }
-}
-#endif
+static int evalskip;            /* set if we are skipping commands */
+/* reasons for skipping commands (see comment on breakcmd routine) */
+#define SKIPBREAK      (1 << 0)
+#define SKIPCONT       (1 << 1)
+#define SKIPFUNC       (1 << 2)
+#define SKIPFILE       (1 << 3)
+#define SKIPEVAL       (1 << 4)
+static int skipcount;           /* number of levels to skip */
+static int funcnest;            /* depth of function calls */
 
+/* forward decl way out to parsing code - dotrap needs it */
+static int evalstring(char *s, int mask);
 
-#ifdef CONFIG_ASH_GETOPTS
+/*
+ * Called to execute a trap.  Perhaps we should avoid entering new trap
+ * handlers while we are executing a trap handler.
+ */
 static int
-getopts(char *optstr, char *optvar, char **optfirst, int *param_optind, int *optoff)
+dotrap(void)
 {
-       char *p, *q;
-       char c = '?';
-       int done = 0;
-       int err = 0;
-       char s[12];
-       char **optnext;
+       char *p;
+       char *q;
+       int i;
+       int savestatus;
+       int skip = 0;
 
-       if(*param_optind < 1)
-               return 1;
-       optnext = optfirst + *param_optind - 1;
+       savestatus = exitstatus;
+       pendingsig = 0;
+       xbarrier();
 
-       if (*param_optind <= 1 || *optoff < 0 || strlen(optnext[-1]) < *optoff)
-               p = NULL;
-       else
-               p = optnext[-1] + *optoff;
-       if (p == NULL || *p == '\0') {
-               /* Current word is done, advance */
-               p = *optnext;
-               if (p == NULL || *p != '-' || *++p == '\0') {
-atend:
-                       p = NULL;
-                       done = 1;
-                       goto out;
-               }
-               optnext++;
-               if (p[0] == '-' && p[1] == '\0')        /* check for "--" */
-                       goto atend;
-       }
+       for (i = 0, q = gotsig; i < NSIG - 1; i++, q++) {
+               if (!*q)
+                       continue;
+               *q = '\0';
 
-       c = *p++;
-       for (q = optstr; *q != c; ) {
-               if (*q == '\0') {
-                       if (optstr[0] == ':') {
-                               s[0] = c;
-                               s[1] = '\0';
-                               err |= setvarsafe("OPTARG", s, 0);
-                       } else {
-                               fprintf(stderr, "Illegal option -%c\n", c);
-                               (void) unsetvar("OPTARG");
-                       }
-                       c = '?';
-                       goto out;
-               }
-               if (*++q == ':')
-                       q++;
+               p = trap[i + 1];
+               if (!p)
+                       continue;
+               skip = evalstring(p, SKIPEVAL);
+               exitstatus = savestatus;
+               if (skip)
+                       break;
        }
 
-       if (*++q == ':') {
-               if (*p == '\0' && (p = *optnext) == NULL) {
-                       if (optstr[0] == ':') {
-                               s[0] = c;
-                               s[1] = '\0';
-                               err |= setvarsafe("OPTARG", s, 0);
-                               c = ':';
-                       } else {
-                               fprintf(stderr, "No arg for -%c option\n", c);
-                               (void) unsetvar("OPTARG");
-                               c = '?';
-                       }
-                       goto out;
-               }
-
-               if (p == *optnext)
-                       optnext++;
-               err |= setvarsafe("OPTARG", p, 0);
-               p = NULL;
-       } else
-               err |= setvarsafe("OPTARG", nullstr, 0);
-
-out:
-       *optoff = p ? p - *(optnext - 1) : -1;
-       *param_optind = optnext - optfirst + 1;
-       fmtstr(s, sizeof(s), "%d", *param_optind);
-       err |= setvarsafe("OPTIND", s, VNOFUNC);
-       s[0] = c;
-       s[1] = '\0';
-       err |= setvarsafe(optvar, s, 0);
-       if (err) {
-               *param_optind = 1;
-               *optoff = -1;
-               flushall();
-               exraise(EXERROR);
-       }
-       return done;
+       return skip;
 }
 
+/* forward declarations - evaluation is fairly recursive business... */
+static void evalloop(union node *, int);
+static void evalfor(union node *, int);
+static void evalcase(union node *, int);
+static void evalsubshell(union node *, int);
+static void expredir(union node *);
+static void evalpipe(union node *, int);
+static void evalcommand(union node *, int);
+static int evalbltin(const struct builtincmd *, int, char **);
+static void prehash(union node *);
+
 /*
- * The getopts builtin.  Shellparam.optnext points to the next argument
- * to be processed.  Shellparam.optptr points to the next character to
- * be processed in the current argument.  If shellparam.optnext is NULL,
- * then it's the first time getopts has been called.
+ * Evaluate a parse tree.  The value is left in the global variable
+ * exitstatus.
  */
-
-int
-getoptscmd(int argc, char **argv)
+static void
+evaltree(union node *n, int flags)
 {
-       char **optbase;
-
-       if (argc < 3)
-               sh_error("Usage: getopts optstring var [arg]");
-       else if (argc == 3) {
-               optbase = shellparam.p;
-               if (shellparam.optind > shellparam.nparam + 1) {
-                       shellparam.optind = 1;
-                       shellparam.optoff = -1;
-               }
+       int checkexit = 0;
+       void (*evalfn)(union node *, int);
+       unsigned isor;
+       int status;
+       if (n == NULL) {
+               TRACE(("evaltree(NULL) called\n"));
+               goto out;
        }
-       else {
-               optbase = &argv[3];
-               if (shellparam.optind > argc - 2) {
-                       shellparam.optind = 1;
-                       shellparam.optoff = -1;
+       TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
+                       getpid(), n, n->type, flags));
+       switch (n->type) {
+       default:
+#if DEBUG
+               out1fmt("Node type = %d\n", n->type);
+               fflush(stdout);
+               break;
+#endif
+       case NNOT:
+               evaltree(n->nnot.com, EV_TESTED);
+               status = !exitstatus;
+               goto setstatus;
+       case NREDIR:
+               expredir(n->nredir.redirect);
+               status = redirectsafe(n->nredir.redirect, REDIR_PUSH);
+               if (!status) {
+                       evaltree(n->nredir.n, flags & EV_TESTED);
+                       status = exitstatus;
+               }
+               popredir(0);
+               goto setstatus;
+       case NCMD:
+               evalfn = evalcommand;
+ checkexit:
+               if (eflag && !(flags & EV_TESTED))
+                       checkexit = ~0;
+               goto calleval;
+       case NFOR:
+               evalfn = evalfor;
+               goto calleval;
+       case NWHILE:
+       case NUNTIL:
+               evalfn = evalloop;
+               goto calleval;
+       case NSUBSHELL:
+       case NBACKGND:
+               evalfn = evalsubshell;
+               goto calleval;
+       case NPIPE:
+               evalfn = evalpipe;
+               goto checkexit;
+       case NCASE:
+               evalfn = evalcase;
+               goto calleval;
+       case NAND:
+       case NOR:
+       case NSEMI:
+#if NAND + 1 != NOR
+#error NAND + 1 != NOR
+#endif
+#if NOR + 1 != NSEMI
+#error NOR + 1 != NSEMI
+#endif
+               isor = n->type - NAND;
+               evaltree(
+                       n->nbinary.ch1,
+                       (flags | ((isor >> 1) - 1)) & EV_TESTED
+               );
+               if (!exitstatus == isor)
+                       break;
+               if (!evalskip) {
+                       n = n->nbinary.ch2;
+ evaln:
+                       evalfn = evaltree;
+ calleval:
+                       evalfn(n, flags);
+                       break;
+               }
+               break;
+       case NIF:
+               evaltree(n->nif.test, EV_TESTED);
+               if (evalskip)
+                       break;
+               if (exitstatus == 0) {
+                       n = n->nif.ifpart;
+                       goto evaln;
+               } else if (n->nif.elsepart) {
+                       n = n->nif.elsepart;
+                       goto evaln;
                }
+               goto success;
+       case NDEFUN:
+               defun(n->narg.text, n->narg.next);
+ success:
+               status = 0;
+ setstatus:
+               exitstatus = status;
+               break;
        }
+ out:
+       if ((checkexit & exitstatus))
+               evalskip |= SKIPEVAL;
+       else if (pendingsig && dotrap())
+               goto exexit;
 
-       return getopts(argv[1], argv[2], optbase, &shellparam.optind,
-                      &shellparam.optoff);
+       if (flags & EV_EXIT) {
+ exexit:
+               raise_exception(EXEXIT);
+       }
 }
-#endif /* CONFIG_ASH_GETOPTS */
 
-/*
- * XXX - should get rid of.  have all builtins use getopt(3).  the
- * library getopt must have the BSD extension static variable "optreset"
- * otherwise it can't be used within the shell safely.
- *
- * Standard option processing (a la getopt) for builtin routines.  The
- * only argument that is passed to nextopt is the option string; the
- * other arguments are unnecessary.  It return the character, or '\0' on
- * end of input.
- */
+#if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
+static
+#endif
+void evaltreenr(union node *, int) __attribute__ ((alias("evaltree"),__noreturn__));
 
-static int
-nextopt(const char *optstring)
+static int loopnest;            /* current loop nesting level */
+
+static void
+evalloop(union node *n, int flags)
 {
-       char *p;
-       const char *q;
-       char c;
+       int status;
 
-       if ((p = optptr) == NULL || *p == '\0') {
-               p = *argptr;
-               if (p == NULL || *p != '-' || *++p == '\0')
-                       return '\0';
-               argptr++;
-               if (p[0] == '-' && p[1] == '\0')        /* check for "--" */
-                       return '\0';
-       }
-       c = *p++;
-       for (q = optstring ; *q != c ; ) {
-               if (*q == '\0')
-                       sh_error("Illegal option -%c", c);
-               if (*++q == ':')
-                       q++;
-       }
-       if (*++q == ':') {
-               if (*p == '\0' && (p = *argptr++) == NULL)
-                       sh_error("No arg for -%c option", c);
-               optionarg = p;
-               p = NULL;
+       loopnest++;
+       status = 0;
+       flags &= EV_TESTED;
+       for (;;) {
+               int i;
+
+               evaltree(n->nbinary.ch1, EV_TESTED);
+               if (evalskip) {
+ skipping:
+                       if (evalskip == SKIPCONT && --skipcount <= 0) {
+                               evalskip = 0;
+                               continue;
+                       }
+                       if (evalskip == SKIPBREAK && --skipcount <= 0)
+                               evalskip = 0;
+                       break;
+               }
+               i = exitstatus;
+               if (n->type != NWHILE)
+                       i = !i;
+               if (i != 0)
+                       break;
+               evaltree(n->nbinary.ch2, flags);
+               status = exitstatus;
+               if (evalskip)
+                       goto skipping;
        }
-       optptr = p;
-       return c;
+       loopnest--;
+       exitstatus = status;
 }
 
+static void
+evalfor(union node *n, int flags)
+{
+       struct arglist arglist;
+       union node *argp;
+       struct strlist *sp;
+       struct stackmark smark;
 
-/*      output.c     */
+       setstackmark(&smark);
+       arglist.lastp = &arglist.list;
+       for (argp = n->nfor.args; argp; argp = argp->narg.next) {
+               expandarg(argp, &arglist, EXP_FULL | EXP_TILDE | EXP_RECORD);
+               /* XXX */
+               if (evalskip)
+                       goto out;
+       }
+       *arglist.lastp = NULL;
 
-void
-outstr(const char *p, FILE *file)
-{
-       INTOFF;
-       fputs(p, file);
-       INTON;
+       exitstatus = 0;
+       loopnest++;
+       flags &= EV_TESTED;
+       for (sp = arglist.list; sp; sp = sp->next) {
+               setvar(n->nfor.var, sp->text, 0);
+               evaltree(n->nfor.body, flags);
+               if (evalskip) {
+                       if (evalskip == SKIPCONT && --skipcount <= 0) {
+                               evalskip = 0;
+                               continue;
+                       }
+                       if (evalskip == SKIPBREAK && --skipcount <= 0)
+                               evalskip = 0;
+                       break;
+               }
+       }
+       loopnest--;
+ out:
+       popstackmark(&smark);
 }
 
-void
-flushall(void)
+static void
+evalcase(union node *n, int flags)
 {
-       INTOFF;
-       fflush(stdout);
-       fflush(stderr);
-       INTON;
-}
+       union node *cp;
+       union node *patp;
+       struct arglist arglist;
+       struct stackmark smark;
 
-void
-flusherr(void)
-{
-       INTOFF;
-       fflush(stderr);
-       INTON;
+       setstackmark(&smark);
+       arglist.lastp = &arglist.list;
+       expandarg(n->ncase.expr, &arglist, EXP_TILDE);
+       exitstatus = 0;
+       for (cp = n->ncase.cases; cp && evalskip == 0; cp = cp->nclist.next) {
+               for (patp = cp->nclist.pattern; patp; patp = patp->narg.next) {
+                       if (casematch(patp, arglist.list->text)) {
+                               if (evalskip == 0) {
+                                       evaltree(cp->nclist.body, flags);
+                               }
+                               goto out;
+                       }
+               }
+       }
+ out:
+       popstackmark(&smark);
 }
 
+/*
+ * Kick off a subshell to evaluate a tree.
+ */
 static void
-outcslow(int c, FILE *dest)
+evalsubshell(union node *n, int flags)
 {
-       INTOFF;
-       putc(c, dest);
-       fflush(dest);
-       INTON;
-}
+       struct job *jp;
+       int backgnd = (n->type == NBACKGND);
+       int status;
 
+       expredir(n->nredir.redirect);
+       if (!backgnd && flags & EV_EXIT && !trap[0])
+               goto nofork;
+       INT_OFF;
+       jp = makejob(n, 1);
+       if (forkshell(jp, n, backgnd) == 0) {
+               INT_ON;
+               flags |= EV_EXIT;
+               if (backgnd)
+                       flags &=~ EV_TESTED;
+ nofork:
+               redirect(n->nredir.redirect, 0);
+               evaltreenr(n->nredir.n, flags);
+               /* never returns */
+       }
+       status = 0;
+       if (! backgnd)
+               status = waitforjob(jp);
+       exitstatus = status;
+       INT_ON;
+}
 
-static int
-out1fmt(const char *fmt, ...)
+/*
+ * Compute the names of the files in a redirection list.
+ */
+static void fixredir(union node *, const char *, int);
+static void
+expredir(union node *n)
 {
-       va_list ap;
-       int r;
+       union node *redir;
 
-       INTOFF;
-       va_start(ap, fmt);
-       r = vprintf(fmt, ap);
-       va_end(ap);
-       INTON;
-       return r;
-}
+       for (redir = n; redir; redir = redir->nfile.next) {
+               struct arglist fn;
 
+               memset(&fn, 0, sizeof(fn));
+               fn.lastp = &fn.list;
+               switch (redir->type) {
+               case NFROMTO:
+               case NFROM:
+               case NTO:
+               case NCLOBBER:
+               case NAPPEND:
+                       expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR);
+                       redir->nfile.expfname = fn.list->text;
+                       break;
+               case NFROMFD:
+               case NTOFD:
+                       if (redir->ndup.vname) {
+                               expandarg(redir->ndup.vname, &fn, EXP_FULL | EXP_TILDE);
+                               if (fn.list == NULL)
+                                       ash_msg_and_raise_error("redir error");
+                               fixredir(redir, fn.list->text, 1);
+                       }
+                       break;
+               }
+       }
+}
 
-int
-fmtstr(char *outbuf, size_t length, const char *fmt, ...)
+/*
+ * Evaluate a pipeline.  All the processes in the pipeline are children
+ * of the process creating the pipeline.  (This differs from some versions
+ * of the shell, which make the last process in a pipeline the parent
+ * of all the rest.)
+ */
+static void
+evalpipe(union node *n, int flags)
 {
-       va_list ap;
-       int ret;
+       struct job *jp;
+       struct nodelist *lp;
+       int pipelen;
+       int prevfd;
+       int pip[2];
 
-       va_start(ap, fmt);
-       INTOFF;
-       ret = vsnprintf(outbuf, length, fmt, ap);
-       va_end(ap);
-       INTON;
-       return ret;
+       TRACE(("evalpipe(0x%lx) called\n", (long)n));
+       pipelen = 0;
+       for (lp = n->npipe.cmdlist; lp; lp = lp->next)
+               pipelen++;
+       flags |= EV_EXIT;
+       INT_OFF;
+       jp = makejob(n, pipelen);
+       prevfd = -1;
+       for (lp = n->npipe.cmdlist; lp; lp = lp->next) {
+               prehash(lp->n);
+               pip[1] = -1;
+               if (lp->next) {
+                       if (pipe(pip) < 0) {
+                               close(prevfd);
+                               ash_msg_and_raise_error("pipe call failed");
+                       }
+               }
+               if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) {
+                       INT_ON;
+                       if (pip[1] >= 0) {
+                               close(pip[0]);
+                       }
+                       if (prevfd > 0) {
+                               dup2(prevfd, 0);
+                               close(prevfd);
+                       }
+                       if (pip[1] > 1) {
+                               dup2(pip[1], 1);
+                               close(pip[1]);
+                       }
+                       evaltreenr(lp->n, flags);
+                       /* never returns */
+               }
+               if (prevfd >= 0)
+                       close(prevfd);
+               prevfd = pip[0];
+               close(pip[1]);
+       }
+       if (n->npipe.backgnd == 0) {
+               exitstatus = waitforjob(jp);
+               TRACE(("evalpipe:  job done exit status %d\n", exitstatus));
+       }
+       INT_ON;
 }
 
-
-
-/*      parser.c     */
-
-
 /*
- * Shell command parser.
+ * Controls whether the shell is interactive or not.
  */
+static void
+setinteractive(int on)
+{
+       static int is_interactive;
 
-#define EOFMARKLEN 79
-
-
-struct heredoc {
-       struct heredoc *next;   /* next here document in list */
-       union node *here;               /* redirection node */
-       char *eofmark;          /* string indicating end of input */
-       int striptabs;          /* if set, strip leading tabs */
-};
-
-
-
-static struct heredoc *heredoclist;    /* list of here documents to read */
-
+       if (++on == is_interactive)
+               return;
+       is_interactive = on;
+       setsignal(SIGINT);
+       setsignal(SIGQUIT);
+       setsignal(SIGTERM);
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
+       if (is_interactive > 1) {
+               /* Looks like they want an interactive shell */
+               static smallint did_banner;
 
-static union node *list(int);
-static union node *andor(void);
-static union node *pipeline(void);
-static union node *command(void);
-static union node *simplecmd(void);
-static union node *makename(void);
-static void parsefname(void);
-static void parseheredoc(void);
-static char peektoken(void);
-static int readtoken(void);
-static int xxreadtoken(void);
-static int readtoken1(int firstc, int syntax, char *eofmark, int striptabs);
-static int noexpand(char *);
-static void synexpect(int) ATTRIBUTE_NORETURN;
-static void synerror(const char *) ATTRIBUTE_NORETURN;
-static void setprompt(int);
+               if (!did_banner) {
+                       out1fmt(
+                               "\n\n"
+                               "%s built-in shell (ash)\n"
+                               "Enter 'help' for a list of built-in commands."
+                               "\n\n",
+                               bb_banner);
+                       did_banner = 1;
+               }
+       }
+#endif
+}
 
+#if ENABLE_FEATURE_EDITING_VI
+#define setvimode(on) do { \
+       if (on) line_input_state->flags |= VI_MODE; \
+       else line_input_state->flags &= ~VI_MODE; \
+} while (0)
+#else
+#define setvimode(on) viflag = 0   /* forcibly keep the option off */
+#endif
 
+static void
+optschanged(void)
+{
+#if DEBUG
+       opentrace();
+#endif
+       setinteractive(iflag);
+       setjobctl(mflag);
+       setvimode(viflag);
+}
 
+static struct localvar *localvars;
 
 /*
- * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
- * valid parse tree indicating a blank line.)
+ * Called after a function returns.
+ * Interrupts must be off.
  */
-
-union node *
-parsecmd(int interact)
+static void
+poplocalvars(void)
 {
-       int t;
+       struct localvar *lvp;
+       struct var *vp;
 
-       tokpushback = 0;
-       doprompt = interact;
-       if (doprompt)
-               setprompt(doprompt);
-       needprompt = 0;
-       t = readtoken();
-       if (t == TEOF)
-               return NEOF;
-       if (t == TNL)
-               return NULL;
-       tokpushback++;
-       return list(1);
+       while ((lvp = localvars) != NULL) {
+               localvars = lvp->next;
+               vp = lvp->vp;
+               TRACE(("poplocalvar %s", vp ? vp->text : "-"));
+               if (vp == NULL) {       /* $- saved */
+                       memcpy(optlist, lvp->text, sizeof(optlist));
+                       free((char*)lvp->text);
+                       optschanged();
+               } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
+                       unsetvar(vp->text);
+               } else {
+                       if (vp->func)
+                               (*vp->func)(strchrnul(lvp->text, '=') + 1);
+                       if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
+                               free((char*)vp->text);
+                       vp->flags = lvp->flags;
+                       vp->text = lvp->text;
+               }
+               free(lvp);
+       }
 }
 
+static int
+evalfun(struct funcnode *func, int argc, char **argv, int flags)
+{
+       volatile struct shparam saveparam;
+       struct localvar *volatile savelocalvars;
+       struct jmploc *volatile savehandler;
+       struct jmploc jmploc;
+       int e;
 
-static union node *
-list(int nlflag)
+       saveparam = shellparam;
+       savelocalvars = localvars;
+       e = setjmp(jmploc.loc);
+       if (e) {
+               goto funcdone;
+       }
+       INT_OFF;
+       savehandler = exception_handler;
+       exception_handler = &jmploc;
+       localvars = NULL;
+       shellparam.malloc = 0;
+       func->count++;
+       funcnest++;
+       INT_ON;
+       shellparam.nparam = argc - 1;
+       shellparam.p = argv + 1;
+#if ENABLE_ASH_GETOPTS
+       shellparam.optind = 1;
+       shellparam.optoff = -1;
+#endif
+       evaltree(&func->n, flags & EV_TESTED);
+funcdone:
+       INT_OFF;
+       funcnest--;
+       freefunc(func);
+       poplocalvars();
+       localvars = savelocalvars;
+       freeparam(&shellparam);
+       shellparam = saveparam;
+       exception_handler = savehandler;
+       INT_ON;
+       evalskip &= ~SKIPFUNC;
+       return e;
+}
+
+#if ENABLE_ASH_CMDCMD
+static char **
+parse_command_args(char **argv, const char **path)
 {
-       union node *n1, *n2, *n3;
-       int tok;
+       char *cp, c;
 
-       checkkwd = CHKNL | CHKKWD | CHKALIAS;
-       if (nlflag == 2 && peektoken())
-               return NULL;
-       n1 = NULL;
        for (;;) {
-               n2 = andor();
-               tok = readtoken();
-               if (tok == TBACKGND) {
-                       if (n2->type == NPIPE) {
-                               n2->npipe.backgnd = 1;
-                       } else {
-                               if (n2->type != NREDIR) {
-                                       n3 = stalloc(sizeof(struct nredir));
-                                       n3->nredir.n = n2;
-                                       n3->nredir.redirect = NULL;
-                                       n2 = n3;
-                               }
-                               n2->type = NBACKGND;
-                       }
-               }
-               if (n1 == NULL) {
-                       n1 = n2;
-               }
-               else {
-                       n3 = (union node *)stalloc(sizeof (struct nbinary));
-                       n3->type = NSEMI;
-                       n3->nbinary.ch1 = n1;
-                       n3->nbinary.ch2 = n2;
-                       n1 = n3;
-               }
-               switch (tok) {
-               case TBACKGND:
-               case TSEMI:
-                       tok = readtoken();
-                       /* fall through */
-               case TNL:
-                       if (tok == TNL) {
-                               parseheredoc();
-                               if (nlflag == 1)
-                                       return n1;
-                       } else {
-                               tokpushback++;
-                       }
-                       checkkwd = CHKNL | CHKKWD | CHKALIAS;
-                       if (peektoken())
-                               return n1;
+               cp = *++argv;
+               if (!cp)
+                       return 0;
+               if (*cp++ != '-')
+                       break;
+               c = *cp++;
+               if (!c)
+                       break;
+               if (c == '-' && !*cp) {
+                       argv++;
                        break;
-               case TEOF:
-                       if (heredoclist)
-                               parseheredoc();
-                       else
-                               pungetc();              /* push back EOF on input */
-                       return n1;
-               default:
-                       if (nlflag == 1)
-                               synexpect(-1);
-                       tokpushback++;
-                       return n1;
                }
+               do {
+                       switch (c) {
+                       case 'p':
+                               *path = bb_default_path;
+                               break;
+                       default:
+                               /* run 'typecmd' for other options */
+                               return 0;
+                       }
+                       c = *cp++;
+               } while (c);
        }
+       return argv;
 }
+#endif
 
-
-
-static union node *
-andor(void)
+/*
+ * Make a variable a local variable.  When a variable is made local, it's
+ * value and flags are saved in a localvar structure.  The saved values
+ * will be restored when the shell function returns.  We handle the name
+ * "-" as a special case.
+ */
+static void
+mklocal(char *name)
 {
-       union node *n1, *n2, *n3;
-       int t;
+       struct localvar *lvp;
+       struct var **vpp;
+       struct var *vp;
 
-       n1 = pipeline();
-       for (;;) {
-               if ((t = readtoken()) == TAND) {
-                       t = NAND;
-               } else if (t == TOR) {
-                       t = NOR;
+       INT_OFF;
+       lvp = ckmalloc(sizeof(struct localvar));
+       if (LONE_DASH(name)) {
+               char *p;
+               p = ckmalloc(sizeof(optlist));
+               lvp->text = memcpy(p, optlist, sizeof(optlist));
+               vp = NULL;
+       } else {
+               char *eq;
+
+               vpp = hashvar(name);
+               vp = *findvar(vpp, name);
+               eq = strchr(name, '=');
+               if (vp == NULL) {
+                       if (eq)
+                               setvareq(name, VSTRFIXED);
+                       else
+                               setvar(name, NULL, VSTRFIXED);
+                       vp = *vpp;      /* the new variable */
+                       lvp->flags = VUNSET;
                } else {
-                       tokpushback++;
-                       return n1;
+                       lvp->text = vp->text;
+                       lvp->flags = vp->flags;
+                       vp->flags |= VSTRFIXED|VTEXTFIXED;
+                       if (eq)
+                               setvareq(name, 0);
                }
-               checkkwd = CHKNL | CHKKWD | CHKALIAS;
-               n2 = pipeline();
-               n3 = (union node *)stalloc(sizeof (struct nbinary));
-               n3->type = t;
-               n3->nbinary.ch1 = n1;
-               n3->nbinary.ch2 = n2;
-               n1 = n3;
        }
+       lvp->vp = vp;
+       lvp->next = localvars;
+       localvars = lvp;
+       INT_ON;
 }
 
-
-
-static union node *
-pipeline(void)
+/*
+ * The "local" command.
+ */
+static int
+localcmd(int argc, char **argv)
 {
-       union node *n1, *n2, *pipenode;
-       struct nodelist *lp, *prev;
-       int negate;
+       char *name;
 
-       negate = 0;
-       TRACE(("pipeline: entered\n"));
-       if (readtoken() == TNOT) {
-               negate = !negate;
-               checkkwd = CHKKWD | CHKALIAS;
-       } else
-               tokpushback++;
-       n1 = command();
-       if (readtoken() == TPIPE) {
-               pipenode = (union node *)stalloc(sizeof (struct npipe));
-               pipenode->type = NPIPE;
-               pipenode->npipe.backgnd = 0;
-               lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
-               pipenode->npipe.cmdlist = lp;
-               lp->n = n1;
-               do {
-                       prev = lp;
-                       lp = (struct nodelist *)stalloc(sizeof (struct nodelist));
-                       checkkwd = CHKNL | CHKKWD | CHKALIAS;
-                       lp->n = command();
-                       prev->next = lp;
-               } while (readtoken() == TPIPE);
-               lp->next = NULL;
-               n1 = pipenode;
+       argv = argptr;
+       while ((name = *argv++) != NULL) {
+               mklocal(name);
        }
-       tokpushback++;
-       if (negate) {
-               n2 = (union node *)stalloc(sizeof (struct nnot));
-               n2->type = NNOT;
-               n2->nnot.com = n1;
-               return n2;
-       } else
-               return n1;
+       return 0;
 }
 
+static int
+falsecmd(int argc, char **argv)
+{
+       return 1;
+}
 
+static int
+truecmd(int argc, char **argv)
+{
+       return 0;
+}
 
-static union node *
-command(void)
+static int
+execcmd(int argc, char **argv)
 {
-       union node *n1, *n2;
-       union node *ap, **app;
-       union node *cp, **cpp;
-       union node *redir, **rpp;
-       union node **rpp2;
-       int t;
+       if (argc > 1) {
+               iflag = 0;              /* exit on error */
+               mflag = 0;
+               optschanged();
+               shellexec(argv + 1, pathval(), 0);
+       }
+       return 0;
+}
 
-       redir = NULL;
-       rpp2 = &redir;
+/*
+ * The return command.
+ */
+static int
+returncmd(int argc, char **argv)
+{
+       /*
+        * If called outside a function, do what ksh does;
+        * skip the rest of the file.
+        */
+       evalskip = funcnest ? SKIPFUNC : SKIPFILE;
+       return argv[1] ? number(argv[1]) : exitstatus;
+}
 
-       switch (readtoken()) {
-       default:
-               synexpect(-1);
-               /* NOTREACHED */
-       case TIF:
-               n1 = (union node *)stalloc(sizeof (struct nif));
-               n1->type = NIF;
-               n1->nif.test = list(0);
-               if (readtoken() != TTHEN)
-                       synexpect(TTHEN);
-               n1->nif.ifpart = list(0);
-               n2 = n1;
-               while (readtoken() == TELIF) {
-                       n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif));
-                       n2 = n2->nif.elsepart;
-                       n2->type = NIF;
-                       n2->nif.test = list(0);
-                       if (readtoken() != TTHEN)
-                               synexpect(TTHEN);
-                       n2->nif.ifpart = list(0);
-               }
-               if (lasttoken == TELSE)
-                       n2->nif.elsepart = list(0);
-               else {
-                       n2->nif.elsepart = NULL;
-                       tokpushback++;
-               }
-               t = TFI;
-               break;
-       case TWHILE:
-       case TUNTIL: {
-               int got;
-               n1 = (union node *)stalloc(sizeof (struct nbinary));
-               n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL;
-               n1->nbinary.ch1 = list(0);
-               if ((got=readtoken()) != TDO) {
-TRACE(("expecting DO got %s %s\n", tokname(got), got == TWORD ? wordtext : ""));
-                       synexpect(TDO);
-               }
-               n1->nbinary.ch2 = list(0);
-               t = TDONE;
-               break;
-       }
-       case TFOR:
-               if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
-                       synerror("Bad for loop variable");
-               n1 = (union node *)stalloc(sizeof (struct nfor));
-               n1->type = NFOR;
-               n1->nfor.var = wordtext;
-               checkkwd = CHKKWD | CHKALIAS;
-               if (readtoken() == TIN) {
-                       app = &ap;
-                       while (readtoken() == TWORD) {
-                               n2 = (union node *)stalloc(sizeof (struct narg));
-                               n2->type = NARG;
-                               n2->narg.text = wordtext;
-                               n2->narg.backquote = backquotelist;
-                               *app = n2;
-                               app = &n2->narg.next;
-                       }
-                       *app = NULL;
-                       n1->nfor.args = ap;
-                       if (lasttoken != TNL && lasttoken != TSEMI)
-                               synexpect(-1);
-               } else {
-                       n2 = (union node *)stalloc(sizeof (struct narg));
-                       n2->type = NARG;
-                       n2->narg.text = (char *)dolatstr;
-                       n2->narg.backquote = NULL;
-                       n2->narg.next = NULL;
-                       n1->nfor.args = n2;
-                       /*
-                        * Newline or semicolon here is optional (but note
-                        * that the original Bourne shell only allowed NL).
-                        */
-                       if (lasttoken != TNL && lasttoken != TSEMI)
-                               tokpushback++;
-               }
-               checkkwd = CHKNL | CHKKWD | CHKALIAS;
-               if (readtoken() != TDO)
-                       synexpect(TDO);
-               n1->nfor.body = list(0);
-               t = TDONE;
-               break;
-       case TCASE:
-               n1 = (union node *)stalloc(sizeof (struct ncase));
-               n1->type = NCASE;
-               if (readtoken() != TWORD)
-                       synexpect(TWORD);
-               n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg));
-               n2->type = NARG;
-               n2->narg.text = wordtext;
-               n2->narg.backquote = backquotelist;
-               n2->narg.next = NULL;
-               do {
-                       checkkwd = CHKKWD | CHKALIAS;
-               } while (readtoken() == TNL);
-               if (lasttoken != TIN)
-                       synexpect(TIN);
-               cpp = &n1->ncase.cases;
-next_case:
-               checkkwd = CHKNL | CHKKWD;
-               t = readtoken();
-               while(t != TESAC) {
-                       if (lasttoken == TLP)
-                               readtoken();
-                       *cpp = cp = (union node *)stalloc(sizeof (struct nclist));
-                       cp->type = NCLIST;
-                       app = &cp->nclist.pattern;
-                       for (;;) {
-                               *app = ap = (union node *)stalloc(sizeof (struct narg));
-                               ap->type = NARG;
-                               ap->narg.text = wordtext;
-                               ap->narg.backquote = backquotelist;
-                               if (readtoken() != TPIPE)
-                                       break;
-                               app = &ap->narg.next;
-                               readtoken();
-                       }
-                       ap->narg.next = NULL;
-                       if (lasttoken != TRP)
-                               synexpect(TRP);
-                       cp->nclist.body = list(2);
+/* Forward declarations for builtintab[] */
+static int breakcmd(int, char **);
+static int dotcmd(int, char **);
+static int evalcmd(int, char **);
+#if ENABLE_ASH_BUILTIN_ECHO
+static int echocmd(int, char **);
+#endif
+#if ENABLE_ASH_BUILTIN_TEST
+static int testcmd(int, char **);
+#endif
+static int exitcmd(int, char **);
+static int exportcmd(int, char **);
+#if ENABLE_ASH_GETOPTS
+static int getoptscmd(int, char **);
+#endif
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
+static int helpcmd(int argc, char **argv);
+#endif
+#if ENABLE_ASH_MATH_SUPPORT
+static int letcmd(int, char **);
+#endif
+static int readcmd(int, char **);
+static int setcmd(int, char **);
+static int shiftcmd(int, char **);
+static int timescmd(int, char **);
+static int trapcmd(int, char **);
+static int umaskcmd(int, char **);
+static int unsetcmd(int, char **);
+static int ulimitcmd(int, char **);
 
-                       cpp = &cp->nclist.next;
+#define BUILTIN_NOSPEC          "0"
+#define BUILTIN_SPECIAL         "1"
+#define BUILTIN_REGULAR         "2"
+#define BUILTIN_SPEC_REG        "3"
+#define BUILTIN_ASSIGN          "4"
+#define BUILTIN_SPEC_ASSG       "5"
+#define BUILTIN_REG_ASSG        "6"
+#define BUILTIN_SPEC_REG_ASSG   "7"
+
+/* make sure to keep these in proper order since it is searched via bsearch() */
+static const struct builtincmd builtintab[] = {
+       { BUILTIN_SPEC_REG      ".", dotcmd },
+       { BUILTIN_SPEC_REG      ":", truecmd },
+#if ENABLE_ASH_BUILTIN_TEST
+       { BUILTIN_REGULAR       "[", testcmd },
+       { BUILTIN_REGULAR       "[[", testcmd },
+#endif
+#if ENABLE_ASH_ALIAS
+       { BUILTIN_REG_ASSG      "alias", aliascmd },
+#endif
+#if JOBS
+       { BUILTIN_REGULAR       "bg", fg_bgcmd },
+#endif
+       { BUILTIN_SPEC_REG      "break", breakcmd },
+       { BUILTIN_REGULAR       "cd", cdcmd },
+       { BUILTIN_NOSPEC        "chdir", cdcmd },
+#if ENABLE_ASH_CMDCMD
+       { BUILTIN_REGULAR       "command", commandcmd },
+#endif
+       { BUILTIN_SPEC_REG      "continue", breakcmd },
+#if ENABLE_ASH_BUILTIN_ECHO
+       { BUILTIN_REGULAR       "echo", echocmd },
+#endif
+       { BUILTIN_SPEC_REG      "eval", evalcmd },
+       { BUILTIN_SPEC_REG      "exec", execcmd },
+       { BUILTIN_SPEC_REG      "exit", exitcmd },
+       { BUILTIN_SPEC_REG_ASSG "export", exportcmd },
+       { BUILTIN_REGULAR       "false", falsecmd },
+#if JOBS
+       { BUILTIN_REGULAR       "fg", fg_bgcmd },
+#endif
+#if ENABLE_ASH_GETOPTS
+       { BUILTIN_REGULAR       "getopts", getoptscmd },
+#endif
+       { BUILTIN_NOSPEC        "hash", hashcmd },
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
+       { BUILTIN_NOSPEC        "help", helpcmd },
+#endif
+#if JOBS
+       { BUILTIN_REGULAR       "jobs", jobscmd },
+       { BUILTIN_REGULAR       "kill", killcmd },
+#endif
+#if ENABLE_ASH_MATH_SUPPORT
+       { BUILTIN_NOSPEC        "let", letcmd },
+#endif
+       { BUILTIN_ASSIGN        "local", localcmd },
+       { BUILTIN_NOSPEC        "pwd", pwdcmd },
+       { BUILTIN_REGULAR       "read", readcmd },
+       { BUILTIN_SPEC_REG_ASSG "readonly", exportcmd },
+       { BUILTIN_SPEC_REG      "return", returncmd },
+       { BUILTIN_SPEC_REG      "set", setcmd },
+       { BUILTIN_SPEC_REG      "shift", shiftcmd },
+       { BUILTIN_SPEC_REG      "source", dotcmd },
+#if ENABLE_ASH_BUILTIN_TEST
+       { BUILTIN_REGULAR       "test", testcmd },
+#endif
+       { BUILTIN_SPEC_REG      "times", timescmd },
+       { BUILTIN_SPEC_REG      "trap", trapcmd },
+       { BUILTIN_REGULAR       "true", truecmd },
+       { BUILTIN_NOSPEC        "type", typecmd },
+       { BUILTIN_NOSPEC        "ulimit", ulimitcmd },
+       { BUILTIN_REGULAR       "umask", umaskcmd },
+#if ENABLE_ASH_ALIAS
+       { BUILTIN_REGULAR       "unalias", unaliascmd },
+#endif
+       { BUILTIN_SPEC_REG      "unset", unsetcmd },
+       { BUILTIN_REGULAR       "wait", waitcmd },
+};
 
-                       checkkwd = CHKNL | CHKKWD;
-                       if ((t = readtoken()) != TESAC) {
-                               if (t != TENDCASE)
-                                       synexpect(TENDCASE);
-                               else
-                                       goto next_case;
-                       }
-               }
-               *cpp = NULL;
-               goto redir;
-       case TLP:
-               n1 = (union node *)stalloc(sizeof (struct nredir));
-               n1->type = NSUBSHELL;
-               n1->nredir.n = list(0);
-               n1->nredir.redirect = NULL;
-               t = TRP;
-               break;
-       case TBEGIN:
-               n1 = list(0);
-               t = TEND;
-               break;
-       case TWORD:
-       case TREDIR:
-               tokpushback++;
-               return simplecmd();
-       }
 
-       if (readtoken() != t)
-               synexpect(t);
+#define COMMANDCMD (builtintab + 5 + \
+       2 * ENABLE_ASH_BUILTIN_TEST + \
+       ENABLE_ASH_ALIAS + \
+       ENABLE_ASH_JOB_CONTROL)
+#define EXECCMD (builtintab + 7 + \
+       2 * ENABLE_ASH_BUILTIN_TEST + \
+       ENABLE_ASH_ALIAS + \
+       ENABLE_ASH_JOB_CONTROL + \
+       ENABLE_ASH_CMDCMD + \
+       ENABLE_ASH_BUILTIN_ECHO)
 
-redir:
-       /* Now check for redirection which may follow command */
-       checkkwd = CHKKWD | CHKALIAS;
-       rpp = rpp2;
-       while (readtoken() == TREDIR) {
-               *rpp = n2 = redirnode;
-               rpp = &n2->nfile.next;
-               parsefname();
-       }
-       tokpushback++;
-       *rpp = NULL;
-       if (redir) {
-               if (n1->type != NSUBSHELL) {
-                       n2 = (union node *)stalloc(sizeof (struct nredir));
-                       n2->type = NREDIR;
-                       n2->nredir.n = n1;
-                       n1 = n2;
-               }
-               n1->nredir.redirect = redir;
-       }
+/*
+ * Search the table of builtin commands.
+ */
+static struct builtincmd *
+find_builtin(const char *name)
+{
+       struct builtincmd *bp;
 
-       return n1;
+       bp = bsearch(
+               name, builtintab, ARRAY_SIZE(builtintab), sizeof(builtintab[0]),
+               pstrcmp
+       );
+       return bp;
 }
 
-
-static union node *
-simplecmd(void) {
-       union node *args, **app;
-       union node *n = NULL;
-       union node *vars, **vpp;
-       union node **rpp, *redir;
-       int savecheckkwd;
-
-       args = NULL;
-       app = &args;
-       vars = NULL;
-       vpp = &vars;
-       redir = NULL;
-       rpp = &redir;
-
-       savecheckkwd = CHKALIAS;
-       for (;;) {
-               checkkwd = savecheckkwd;
-               switch (readtoken()) {
-               case TWORD:
-                       n = (union node *)stalloc(sizeof (struct narg));
-                       n->type = NARG;
-                       n->narg.text = wordtext;
-                       n->narg.backquote = backquotelist;
-                       if (savecheckkwd && isassignment(wordtext)) {
-                               *vpp = n;
-                               vpp = &n->narg.next;
-                       } else {
-                               *app = n;
-                               app = &n->narg.next;
-                               savecheckkwd = 0;
-                       }
-                       break;
-               case TREDIR:
-                       *rpp = n = redirnode;
-                       rpp = &n->nfile.next;
-                       parsefname();   /* read name of redirection file */
-                       break;
-               case TLP:
-                       if (
-                               args && app == &args->narg.next &&
-                               !vars && !redir
-                       ) {
-                               struct builtincmd *bcmd;
-                               const char *name;
-
-                               /* We have a function */
-                               if (readtoken() != TRP)
-                                       synexpect(TRP);
-                               name = n->narg.text;
-                               if (
-                                       !goodname(name) || (
-                                               (bcmd = find_builtin(name)) &&
-                                               IS_BUILTIN_SPECIAL(bcmd)
-                                       )
-                               )
-                                       synerror("Bad function name");
-                               n->type = NDEFUN;
-                               checkkwd = CHKNL | CHKKWD | CHKALIAS;
-                               n->narg.next = command();
-                               return n;
-                       }
-                       /* fall through */
-               default:
-                       tokpushback++;
-                       goto out;
-               }
-       }
-out:
-       *app = NULL;
-       *vpp = NULL;
-       *rpp = NULL;
-       n = (union node *)stalloc(sizeof (struct ncmd));
-       n->type = NCMD;
-       n->ncmd.args = args;
-       n->ncmd.assign = vars;
-       n->ncmd.redirect = redir;
-       return n;
+/*
+ * Execute a simple command.
+ */
+static int back_exitstatus; /* exit status of backquoted command */
+static int
+isassignment(const char *p)
+{
+       const char *q = endofname(p);
+       if (p == q)
+               return 0;
+       return *q == '=';
 }
-
-static union node *
-makename(void)
+static int
+bltincmd(int argc, char **argv)
 {
-       union node *n;
-
-       n = (union node *)stalloc(sizeof (struct narg));
-       n->type = NARG;
-       n->narg.next = NULL;
-       n->narg.text = wordtext;
-       n->narg.backquote = backquotelist;
-       return n;
+       /* Preserve exitstatus of a previous possible redirection
+        * as POSIX mandates */
+       return back_exitstatus;
 }
-
-void fixredir(union node *n, const char *text, int err)
+static void
+evalcommand(union node *cmd, int flags)
 {
-       TRACE(("Fix redir %s %d\n", text, err));
-       if (!err)
-               n->ndup.vname = NULL;
+       static const struct builtincmd bltin = {
+               "\0\0", bltincmd
+       };
+       struct stackmark smark;
+       union node *argp;
+       struct arglist arglist;
+       struct arglist varlist;
+       char **argv;
+       int argc;
+       const struct strlist *sp;
+       struct cmdentry cmdentry;
+       struct job *jp;
+       char *lastarg;
+       const char *path;
+       int spclbltin;
+       int cmd_is_exec;
+       int status;
+       char **nargv;
+       struct builtincmd *bcmd;
+       int pseudovarflag = 0;
 
-       if (is_digit(text[0]) && text[1] == '\0')
-               n->ndup.dupfd = digit_val(text[0]);
-       else if (text[0] == '-' && text[1] == '\0')
-               n->ndup.dupfd = -1;
-       else {
+       /* First expand the arguments. */
+       TRACE(("evalcommand(0x%lx, %d) called\n", (long)cmd, flags));
+       setstackmark(&smark);
+       back_exitstatus = 0;
 
-               if (err)
-                       synerror("Bad fd number");
-               else
-                       n->ndup.vname = makename();
+       cmdentry.cmdtype = CMDBUILTIN;
+       cmdentry.u.cmd = &bltin;
+       varlist.lastp = &varlist.list;
+       *varlist.lastp = NULL;
+       arglist.lastp = &arglist.list;
+       *arglist.lastp = NULL;
+
+       argc = 0;
+       if (cmd->ncmd.args) {
+               bcmd = find_builtin(cmd->ncmd.args->narg.text);
+               pseudovarflag = bcmd && IS_BUILTIN_ASSIGN(bcmd);
        }
-}
 
+       for (argp = cmd->ncmd.args; argp; argp = argp->narg.next) {
+               struct strlist **spp;
 
-static void
-parsefname(void)
-{
-       union node *n = redirnode;
+               spp = arglist.lastp;
+               if (pseudovarflag && isassignment(argp->narg.text))
+                       expandarg(argp, &arglist, EXP_VARTILDE);
+               else
+                       expandarg(argp, &arglist, EXP_FULL | EXP_TILDE);
 
-       if (readtoken() != TWORD)
-               synexpect(-1);
-       if (n->type == NHERE) {
-               struct heredoc *here = heredoc;
-               struct heredoc *p;
-               int i;
+               for (sp = *spp; sp; sp = sp->next)
+                       argc++;
+       }
 
-               if (quoteflag == 0)
-                       n->type = NXHERE;
-               TRACE(("Here document %d\n", n->type));
-               if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
-                       synerror("Illegal eof marker for << redirection");
-               rmescapes(wordtext);
-               here->eofmark = wordtext;
-               here->next = NULL;
-               if (heredoclist == NULL)
-                       heredoclist = here;
-               else {
-                       for (p = heredoclist ; p->next ; p = p->next);
-                       p->next = here;
-               }
-       } else if (n->type == NTOFD || n->type == NFROMFD) {
-               fixredir(n, wordtext, 0);
-       } else {
-               n->nfile.fname = makename();
+       argv = nargv = stalloc(sizeof(char *) * (argc + 1));
+       for (sp = arglist.list; sp; sp = sp->next) {
+               TRACE(("evalcommand arg: %s\n", sp->text));
+               *nargv++ = sp->text;
        }
-}
+       *nargv = NULL;
 
+       lastarg = NULL;
+       if (iflag && funcnest == 0 && argc > 0)
+               lastarg = nargv[-1];
 
-/*
- * Input any here documents.
- */
+       preverrout_fd = 2;
+       expredir(cmd->ncmd.redirect);
+       status = redirectsafe(cmd->ncmd.redirect, REDIR_PUSH | REDIR_SAVEFD2);
+
+       path = vpath.text;
+       for (argp = cmd->ncmd.assign; argp; argp = argp->narg.next) {
+               struct strlist **spp;
+               char *p;
+
+               spp = varlist.lastp;
+               expandarg(argp, &varlist, EXP_VARTILDE);
+
+               /*
+                * Modify the command lookup path, if a PATH= assignment
+                * is present
+                */
+               p = (*spp)->text;
+               if (varequal(p, path))
+                       path = p;
+       }
 
-static void
-parseheredoc(void)
-{
-       struct heredoc *here;
-       union node *n;
+       /* Print the command if xflag is set. */
+       if (xflag) {
+               int n;
+               const char *p = " %s";
 
-       here = heredoclist;
-       heredoclist = 0;
+               p++;
+               dprintf(preverrout_fd, p, expandstr(ps4val()));
 
-       while (here) {
-               if (needprompt) {
-                       setprompt(2);
+               sp = varlist.list;
+               for (n = 0; n < 2; n++) {
+                       while (sp) {
+                               dprintf(preverrout_fd, p, sp->text);
+                               sp = sp->next;
+                               if (*p == '%') {
+                                       p--;
+                               }
+                       }
+                       sp = arglist.list;
                }
-               readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
-                               here->eofmark, here->striptabs);
-               n = (union node *)stalloc(sizeof (struct narg));
-               n->narg.type = NARG;
-               n->narg.next = NULL;
-               n->narg.text = wordtext;
-               n->narg.backquote = backquotelist;
-               here->here->nhere.doc = n;
-               here = here->next;
+               full_write(preverrout_fd, "\n", 1);
        }
-}
 
-static char peektoken(void)
-{
-       int t;
+       cmd_is_exec = 0;
+       spclbltin = -1;
 
-       t = readtoken();
-       tokpushback++;
-       return tokname_array[t][0];
-}
+       /* Now locate the command. */
+       if (argc) {
+               const char *oldpath;
+               int cmd_flag = DO_ERR;
 
-static int
-readtoken(void)
-{
-       int t;
-#if DEBUG
-       int alreadyseen = tokpushback;
-#endif
+               path += 5;
+               oldpath = path;
+               for (;;) {
+                       find_command(argv[0], &cmdentry, cmd_flag, path);
+                       if (cmdentry.cmdtype == CMDUNKNOWN) {
+                               status = 127;
+                               flush_stderr();
+                               goto bail;
+                       }
 
-#ifdef CONFIG_ASH_ALIAS
-top:
+                       /* implement bltin and command here */
+                       if (cmdentry.cmdtype != CMDBUILTIN)
+                               break;
+                       if (spclbltin < 0)
+                               spclbltin = IS_BUILTIN_SPECIAL(cmdentry.u.cmd);
+                       if (cmdentry.u.cmd == EXECCMD)
+                               cmd_is_exec++;
+#if ENABLE_ASH_CMDCMD
+                       if (cmdentry.u.cmd == COMMANDCMD) {
+                               path = oldpath;
+                               nargv = parse_command_args(argv, &path);
+                               if (!nargv)
+                                       break;
+                               argc -= nargv - argv;
+                               argv = nargv;
+                               cmd_flag |= DO_NOFUNC;
+                       } else
 #endif
-
-       t = xxreadtoken();
-
-       /*
-        * eat newlines
-        */
-       if (checkkwd & CHKNL) {
-               while (t == TNL) {
-                       parseheredoc();
-                       t = xxreadtoken();
+                               break;
                }
        }
 
-       if (t != TWORD || quoteflag) {
+       if (status) {
+               /* We have a redirection error. */
+               if (spclbltin > 0)
+                       raise_exception(EXERROR);
+ bail:
+               exitstatus = status;
                goto out;
        }
 
-       /*
-        * check for keywords
-        */
-       if (checkkwd & CHKKWD) {
-               const char *const *pp;
-
-               if ((pp = findkwd(wordtext))) {
-                       lasttoken = t = pp - tokname_array;
-                       TRACE(("keyword %s recognized\n", tokname(t)));
-                       goto out;
+       /* Execute the command. */
+       switch (cmdentry.cmdtype) {
+       default:
+               /* Fork off a child process if necessary. */
+               if (!(flags & EV_EXIT) || trap[0]) {
+                       INT_OFF;
+                       jp = makejob(cmd, 1);
+                       if (forkshell(jp, cmd, FORK_FG) != 0) {
+                               exitstatus = waitforjob(jp);
+                               INT_ON;
+                               break;
+                       }
+                       FORCE_INT_ON;
                }
-       }
+               listsetvar(varlist.list, VEXPORT|VSTACK);
+               shellexec(argv, path, cmdentry.u.index);
+               /* NOTREACHED */
 
-       if (checkkwd & CHKALIAS) {
-#ifdef CONFIG_ASH_ALIAS
-               struct alias *ap;
-               if ((ap = lookupalias(wordtext, 1)) != NULL) {
-                       if (*ap->val) {
-                               pushstring(ap->val, ap);
+       case CMDBUILTIN:
+               cmdenviron = varlist.list;
+               if (cmdenviron) {
+                       struct strlist *list = cmdenviron;
+                       int i = VNOSET;
+                       if (spclbltin > 0 || argc == 0) {
+                               i = 0;
+                               if (cmd_is_exec && argc > 1)
+                                       i = VEXPORT;
                        }
-                       goto top;
+                       listsetvar(list, i);
                }
-#endif
-       }
-out:
-       checkkwd = 0;
-#if DEBUG
-       if (!alreadyseen)
-           TRACE(("token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
-       else
-           TRACE(("reread token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
-#endif
-       return t;
-}
-
-
-/*
- * Read the next input token.
- * If the token is a word, we set backquotelist to the list of cmds in
- *      backquotes.  We set quoteflag to true if any part of the word was
- *      quoted.
- * If the token is TREDIR, then we set redirnode to a structure containing
- *      the redirection.
- * In all cases, the variable startlinno is set to the number of the line
- *      on which the token starts.
- *
- * [Change comment:  here documents and internal procedures]
- * [Readtoken shouldn't have any arguments.  Perhaps we should make the
- *  word parsing code into a separate routine.  In this case, readtoken
- *  doesn't need to have any internal procedures, but parseword does.
- *  We could also make parseoperator in essence the main routine, and
- *  have parseword (readtoken1?) handle both words and redirection.]
- */
-
-#define NEW_xxreadtoken
-#ifdef NEW_xxreadtoken
-
-/* singles must be first! */
-static const char xxreadtoken_chars[7] = { '\n', '(', ')', '&', '|', ';', 0 };
+               if (evalbltin(cmdentry.u.cmd, argc, argv)) {
+                       int exit_status;
+                       int i, j;
 
-static const char xxreadtoken_tokens[] = {
-       TNL, TLP, TRP,          /* only single occurrence allowed */
-       TBACKGND, TPIPE, TSEMI, /* if single occurrence */
-       TEOF,                   /* corresponds to trailing nul */
-       TAND, TOR, TENDCASE,    /* if double occurrence */
-};
+                       i = exception;
+                       if (i == EXEXIT)
+                               goto raise;
 
-#define xxreadtoken_doubles \
-       (sizeof(xxreadtoken_tokens) - sizeof(xxreadtoken_chars))
-#define xxreadtoken_singles \
-       (sizeof(xxreadtoken_chars) - xxreadtoken_doubles - 1)
+                       exit_status = 2;
+                       j = 0;
+                       if (i == EXINT)
+                               j = SIGINT;
+                       if (i == EXSIG)
+                               j = pendingsig;
+                       if (j)
+                               exit_status = j + 128;
+                       exitstatus = exit_status;
 
-static int xxreadtoken(void)
-{
-       int c;
+                       if (i == EXINT || spclbltin > 0) {
+ raise:
+                               longjmp(exception_handler->loc, 1);
+                       }
+                       FORCE_INT_ON;
+               }
+               break;
 
-       if (tokpushback) {
-               tokpushback = 0;
-               return lasttoken;
-       }
-       if (needprompt) {
-               setprompt(2);
+       case CMDFUNCTION:
+               listsetvar(varlist.list, 0);
+               if (evalfun(cmdentry.u.func, argc, argv, flags))
+                       goto raise;
+               break;
        }
-       startlinno = plinno;
-       for (;;) {                      /* until token or start of word found */
-               c = pgetc_macro();
-
-               if ((c != ' ') && (c != '\t')
-#ifdef CONFIG_ASH_ALIAS
-                       && (c != PEOA)
-#endif
-                       ) {
-                       if (c == '#') {
-                               while ((c = pgetc()) != '\n' && c != PEOF);
-                               pungetc();
-                       } else if (c == '\\') {
-                               if (pgetc() != '\n') {
-                                       pungetc();
-                                       goto READTOKEN1;
-                               }
-                               startlinno = ++plinno;
-                               if (doprompt)
-                                       setprompt(2);
-                       } else {
-                               const char *p
-                                       = xxreadtoken_chars + sizeof(xxreadtoken_chars) - 1;
-
-                               if (c != PEOF) {
-                                       if (c == '\n') {
-                                               plinno++;
-                                               needprompt = doprompt;
-                                       }
 
-                                       p = strchr(xxreadtoken_chars, c);
-                                       if (p == NULL) {
-                                         READTOKEN1:
-                                               return readtoken1(c, BASESYNTAX, (char *) NULL, 0);
-                                       }
+ out:
+       popredir(cmd_is_exec);
+       if (lastarg)
+               /* dsl: I think this is intended to be used to support
+                * '_' in 'vi' command mode during line editing...
+                * However I implemented that within libedit itself.
+                */
+               setvar("_", lastarg, 0);
+       popstackmark(&smark);
+}
 
-                                       if (p - xxreadtoken_chars >= xxreadtoken_singles) {
-                                               if (pgetc() == *p) {    /* double occurrence? */
-                                                       p += xxreadtoken_doubles + 1;
-                                               } else {
-                                                       pungetc();
-                                               }
-                                       }
-                               }
+static int
+evalbltin(const struct builtincmd *cmd, int argc, char **argv)
+{
+       char *volatile savecmdname;
+       struct jmploc *volatile savehandler;
+       struct jmploc jmploc;
+       int i;
 
-                               return lasttoken = xxreadtoken_tokens[p - xxreadtoken_chars];
-                       }
-               }
-       }
+       savecmdname = commandname;
+       i = setjmp(jmploc.loc);
+       if (i)
+               goto cmddone;
+       savehandler = exception_handler;
+       exception_handler = &jmploc;
+       commandname = argv[0];
+       argptr = argv + 1;
+       optptr = NULL;                  /* initialize nextopt */
+       exitstatus = (*cmd->builtin)(argc, argv);
+       flush_stdout_stderr();
+ cmddone:
+       exitstatus |= ferror(stdout);
+       clearerr(stdout);
+       commandname = savecmdname;
+       exsig = 0;
+       exception_handler = savehandler;
+
+       return i;
 }
 
+static int
+goodname(const char *p)
+{
+       return !*endofname(p);
+}
 
-#else
-#define RETURN(token)   return lasttoken = token
 
-static int
-xxreadtoken(void)
+/*
+ * Search for a command.  This is called before we fork so that the
+ * location of the command will be available in the parent as well as
+ * the child.  The check for "goodname" is an overly conservative
+ * check that the name will not be subject to expansion.
+ */
+static void
+prehash(union node *n)
 {
-       int c;
+       struct cmdentry entry;
 
-       if (tokpushback) {
-               tokpushback = 0;
-               return lasttoken;
-       }
-       if (needprompt) {
-               setprompt(2);
-       }
-       startlinno = plinno;
-       for (;;) {      /* until token or start of word found */
-               c = pgetc_macro();
-               switch (c) {
-               case ' ': case '\t':
-#ifdef CONFIG_ASH_ALIAS
-               case PEOA:
-#endif
-                       continue;
-               case '#':
-                       while ((c = pgetc()) != '\n' && c != PEOF);
-                       pungetc();
-                       continue;
-               case '\\':
-                       if (pgetc() == '\n') {
-                               startlinno = ++plinno;
-                               if (doprompt)
-                                       setprompt(2);
-                               continue;
-                       }
-                       pungetc();
-                       goto breakloop;
-               case '\n':
-                       plinno++;
-                       needprompt = doprompt;
-                       RETURN(TNL);
-               case PEOF:
-                       RETURN(TEOF);
-               case '&':
-                       if (pgetc() == '&')
-                               RETURN(TAND);
-                       pungetc();
-                       RETURN(TBACKGND);
-               case '|':
-                       if (pgetc() == '|')
-                               RETURN(TOR);
-                       pungetc();
-                       RETURN(TPIPE);
-               case ';':
-                       if (pgetc() == ';')
-                               RETURN(TENDCASE);
-                       pungetc();
-                       RETURN(TSEMI);
-               case '(':
-                       RETURN(TLP);
-               case ')':
-                       RETURN(TRP);
-               default:
-                       goto breakloop;
-               }
-       }
-breakloop:
-       return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
-#undef RETURN
+       if (n->type == NCMD && n->ncmd.args && goodname(n->ncmd.args->narg.text))
+               find_command(n->ncmd.args->narg.text, &entry, 0, pathval());
 }
-#endif /* NEW_xxreadtoken */
 
 
-/*
- * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
- * is not NULL, read a here document.  In the latter case, eofmark is the
- * word which marks the end of the document and striptabs is true if
- * leading tabs should be stripped from the document.  The argument firstc
- * is the first character of the input token or document.
+/* ============ Builtin commands
  *
- * Because C does not have internal subroutines, I have simulated them
- * using goto's to implement the subroutine linkage.  The following macros
- * will run code that appears at the end of readtoken1.
+ * Builtin commands whose functions are closely tied to evaluation
+ * are implemented here.
  */
 
-#define CHECKEND()      {goto checkend; checkend_return:;}
-#define PARSEREDIR()    {goto parseredir; parseredir_return:;}
-#define PARSESUB()      {goto parsesub; parsesub_return:;}
-#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
-#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
-#define PARSEARITH()    {goto parsearith; parsearith_return:;}
-
+/*
+ * Handle break and continue commands.  Break, continue, and return are
+ * all handled by setting the evalskip flag.  The evaluation routines
+ * above all check this flag, and if it is set they start skipping
+ * commands rather than executing them.  The variable skipcount is
+ * the number of loops to break/continue, or the number of function
+ * levels to return.  (The latter is always 1.)  It should probably
+ * be an error to break out of more loops than exist, but it isn't
+ * in the standard shell so we don't make it one here.
+ */
 static int
-readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
+breakcmd(int argc, char **argv)
 {
-       int c = firstc;
-       char *out;
-       int len;
-       char line[EOFMARKLEN + 1];
-       struct nodelist *bqlist = 0;
-       int quotef = 0;
-       int dblquote = 0;
-       int varnest = 0;    /* levels of variables expansion */
-       int arinest = 0;    /* levels of arithmetic expansion */
-       int parenlevel = 0; /* levels of parens in arithmetic */
-       int dqvarnest = 0;  /* levels of variables expansion within double quotes */
-       int oldstyle = 0;
-       int prevsyntax = 0; /* syntax before arithmetic */
-#if __GNUC__
-       /* Avoid longjmp clobbering */
-       (void) &out;
-       (void) &quotef;
-       (void) &dblquote;
-       (void) &varnest;
-       (void) &arinest;
-       (void) &parenlevel;
-       (void) &dqvarnest;
-       (void) &oldstyle;
-       (void) &prevsyntax;
-       (void) &syntax;
-#endif
-
-       startlinno = plinno;
-       dblquote = 0;
-       if (syntax == DQSYNTAX)
-               dblquote = 1;
-       quotef = 0;
-       bqlist = NULL;
-       varnest = 0;
-       arinest = 0;
-       parenlevel = 0;
-       dqvarnest = 0;
+       int n = argc > 1 ? number(argv[1]) : 1;
 
-       STARTSTACKSTR(out);
-       loop: { /* for each line, until end of word */
-               CHECKEND();     /* set c to PEOF if at end of here document */
-               for (;;) {      /* until end of line or end of word */
-                       CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
-                       switch(SIT(c, syntax)) {
-                       case CNL:       /* '\n' */
-                               if (syntax == BASESYNTAX)
-                                       goto endword;   /* exit outer loop */
-                               USTPUTC(c, out);
-                               plinno++;
-                               if (doprompt)
-                                       setprompt(2);
-                               c = pgetc();
-                               goto loop;              /* continue outer loop */
-                       case CWORD:
-                               USTPUTC(c, out);
-                               break;
-                       case CCTL:
-                               if (eofmark == NULL || dblquote)
-                                       USTPUTC(CTLESC, out);
-                               USTPUTC(c, out);
-                               break;
-                       case CBACK:     /* backslash */
-                               c = pgetc2();
-                               if (c == PEOF) {
-                                       USTPUTC(CTLESC, out);
-                                       USTPUTC('\\', out);
-                                       pungetc();
-                               } else if (c == '\n') {
-                                       if (doprompt)
-                                               setprompt(2);
-                               } else {
-                                       if (dblquote &&
-                                               c != '\\' && c != '`' &&
-                                               c != '$' && (
-                                                       c != '"' ||
-                                                       eofmark != NULL)
-                                       ) {
-                                               USTPUTC(CTLESC, out);
-                                               USTPUTC('\\', out);
-                                       }
-                                       if (SIT(c, SQSYNTAX) == CCTL)
-                                               USTPUTC(CTLESC, out);
-                                       USTPUTC(c, out);
-                                       quotef++;
-                               }
-                               break;
-                       case CSQUOTE:
-                               syntax = SQSYNTAX;
-quotemark:
-                               if (eofmark == NULL) {
-                                       USTPUTC(CTLQUOTEMARK, out);
-                               }
-                               break;
-                       case CDQUOTE:
-                               syntax = DQSYNTAX;
-                               dblquote = 1;
-                               goto quotemark;
-                       case CENDQUOTE:
-                               if (eofmark != NULL && arinest == 0 &&
-                                   varnest == 0) {
-                                       USTPUTC(c, out);
-                               } else {
-                                       if (dqvarnest == 0) {
-                                               syntax = BASESYNTAX;
-                                               dblquote = 0;
-                                       }
-                                       quotef++;
-                                       goto quotemark;
-                               }
-                               break;
-                       case CVAR:      /* '$' */
-                               PARSESUB();             /* parse substitution */
-                               break;
-                       case CENDVAR:   /* '}' */
-                               if (varnest > 0) {
-                                       varnest--;
-                                       if (dqvarnest > 0) {
-                                               dqvarnest--;
-                                       }
-                                       USTPUTC(CTLENDVAR, out);
-                               } else {
-                                       USTPUTC(c, out);
-                               }
-                               break;
-#ifdef CONFIG_ASH_MATH_SUPPORT
-                       case CLP:       /* '(' in arithmetic */
-                               parenlevel++;
-                               USTPUTC(c, out);
-                               break;
-                       case CRP:       /* ')' in arithmetic */
-                               if (parenlevel > 0) {
-                                       USTPUTC(c, out);
-                                       --parenlevel;
-                               } else {
-                                       if (pgetc() == ')') {
-                                               if (--arinest == 0) {
-                                                       USTPUTC(CTLENDARI, out);
-                                                       syntax = prevsyntax;
-                                                       if (syntax == DQSYNTAX)
-                                                               dblquote = 1;
-                                                       else
-                                                               dblquote = 0;
-                                               } else
-                                                       USTPUTC(')', out);
-                                       } else {
-                                               /*
-                                                * unbalanced parens
-                                                *  (don't 2nd guess - no error)
-                                                */
-                                               pungetc();
-                                               USTPUTC(')', out);
-                                       }
-                               }
-                               break;
+       if (n <= 0)
+               ash_msg_and_raise_error(illnum, argv[1]);
+       if (n > loopnest)
+               n = loopnest;
+       if (n > 0) {
+               evalskip = (**argv == 'c') ? SKIPCONT : SKIPBREAK;
+               skipcount = n;
+       }
+       return 0;
+}
+
+
+/* ============ input.c
+ *
+ * This implements the input routines used by the parser.
+ */
+
+#define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
+
+enum {
+       INPUT_PUSH_FILE = 1,
+       INPUT_NOFILE_OK = 2,
+};
+
+static int plinno = 1;                  /* input line number */
+/* number of characters left in input buffer */
+static int parsenleft;                  /* copy of parsefile->nleft */
+static int parselleft;                  /* copy of parsefile->lleft */
+/* next character in input buffer */
+static char *parsenextc;                /* copy of parsefile->nextc */
+
+static int checkkwd;
+/* values of checkkwd variable */
+#define CHKALIAS        0x1
+#define CHKKWD          0x2
+#define CHKNL           0x4
+
+static void
+popstring(void)
+{
+       struct strpush *sp = parsefile->strpush;
+
+       INT_OFF;
+#if ENABLE_ASH_ALIAS
+       if (sp->ap) {
+               if (parsenextc[-1] == ' ' || parsenextc[-1] == '\t') {
+                       checkkwd |= CHKALIAS;
+               }
+               if (sp->string != sp->ap->val) {
+                       free(sp->string);
+               }
+               sp->ap->flag &= ~ALIASINUSE;
+               if (sp->ap->flag & ALIASDEAD) {
+                       unalias(sp->ap->name);
+               }
+       }
 #endif
-                       case CBQUOTE:   /* '`' */
-                               PARSEBACKQOLD();
-                               break;
-                       case CENDFILE:
-                               goto endword;           /* exit outer loop */
-                       case CIGN:
-                               break;
-                       default:
-                               if (varnest == 0)
-                                       goto endword;   /* exit outer loop */
-#ifdef CONFIG_ASH_ALIAS
-                               if (c != PEOA)
+       parsenextc = sp->prevstring;
+       parsenleft = sp->prevnleft;
+/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
+       parsefile->strpush = sp->prev;
+       if (sp != &(parsefile->basestrpush))
+               free(sp);
+       INT_ON;
+}
+
+static int
+preadfd(void)
+{
+       int nr;
+       char *buf =  parsefile->buf;
+       parsenextc = buf;
+
+ retry:
+#if ENABLE_FEATURE_EDITING
+       if (!iflag || parsefile->fd)
+               nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
+       else {
+#if ENABLE_FEATURE_TAB_COMPLETION
+               line_input_state->path_lookup = pathval();
+#endif
+               nr = read_line_input(cmdedit_prompt, buf, BUFSIZ, line_input_state);
+               if (nr == 0) {
+                       /* Ctrl+C pressed */
+                       if (trap[SIGINT]) {
+                               buf[0] = '\n';
+                               buf[1] = '\0';
+                               raise(SIGINT);
+                               return 1;
+                       }
+                       goto retry;
+               }
+               if (nr < 0 && errno == 0) {
+                       /* Ctrl+D presend */
+                       nr = 0;
+               }
+       }
+#else
+       nr = safe_read(parsefile->fd, buf, BUFSIZ - 1);
 #endif
-                                       USTPUTC(c, out);
 
+       if (nr < 0) {
+               if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
+                       int flags = fcntl(0, F_GETFL);
+                       if (flags >= 0 && flags & O_NONBLOCK) {
+                               flags &=~ O_NONBLOCK;
+                               if (fcntl(0, F_SETFL, flags) >= 0) {
+                                       out2str("sh: turning off NDELAY mode\n");
+                                       goto retry;
+                               }
                        }
-                       c = pgetc_macro();
                }
        }
-endword:
-#ifdef CONFIG_ASH_MATH_SUPPORT
-       if (syntax == ARISYNTAX)
-               synerror("Missing '))'");
+       return nr;
+}
+
+/*
+ * Refill the input buffer and return the next input character:
+ *
+ * 1) If a string was pushed back on the input, pop it;
+ * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
+ *    from a string so we can't refill the buffer, return EOF.
+ * 3) If the is more stuff in this buffer, use it else call read to fill it.
+ * 4) Process input up to the next newline, deleting nul characters.
+ */
+static int
+preadbuffer(void)
+{
+       char *q;
+       int more;
+       char savec;
+
+       while (parsefile->strpush) {
+#if ENABLE_ASH_ALIAS
+               if (parsenleft == -1 && parsefile->strpush->ap &&
+                       parsenextc[-1] != ' ' && parsenextc[-1] != '\t') {
+                       return PEOA;
+               }
 #endif
-       if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL)
-               synerror("Unterminated quoted string");
-       if (varnest != 0) {
-               startlinno = plinno;
-               /* { */
-               synerror("Missing '}'");
+               popstring();
+               if (--parsenleft >= 0)
+                       return signed_char2int(*parsenextc++);
        }
-       USTPUTC('\0', out);
-       len = out - (char *)stackblock();
-       out = stackblock();
-       if (eofmark == NULL) {
-               if ((c == '>' || c == '<')
-                && quotef == 0
-                && len <= 2
-                && (*out == '\0' || is_digit(*out))) {
-                       PARSEREDIR();
-                       return lasttoken = TREDIR;
-               } else {
-                       pungetc();
+       if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
+               return PEOF;
+       flush_stdout_stderr();
+
+       more = parselleft;
+       if (more <= 0) {
+ again:
+               more = preadfd();
+               if (more <= 0) {
+                       parselleft = parsenleft = EOF_NLEFT;
+                       return PEOF;
                }
        }
-       quoteflag = quotef;
-       backquotelist = bqlist;
-       grabstackblock(len);
-       wordtext = out;
-       return lasttoken = TWORD;
-/* end of readtoken routine */
 
+       q = parsenextc;
+
+       /* delete nul characters */
+       for (;;) {
+               int c;
+
+               more--;
+               c = *q;
+
+               if (!c)
+                       memmove(q, q + 1, more);
+               else {
+                       q++;
+                       if (c == '\n') {
+                               parsenleft = q - parsenextc - 1;
+                               break;
+                       }
+               }
+
+               if (more <= 0) {
+                       parsenleft = q - parsenextc - 1;
+                       if (parsenleft < 0)
+                               goto again;
+                       break;
+               }
+       }
+       parselleft = more;
+
+       savec = *q;
+       *q = '\0';
+
+       if (vflag) {
+               out2str(parsenextc);
+       }
+
+       *q = savec;
+
+       return signed_char2int(*parsenextc++);
+}
+
+#define pgetc_as_macro() (--parsenleft >= 0? signed_char2int(*parsenextc++) : preadbuffer())
+static int
+pgetc(void)
+{
+       return pgetc_as_macro();
+}
 
+#if ENABLE_ASH_OPTIMIZE_FOR_SIZE
+#define pgetc_macro() pgetc()
+#else
+#define pgetc_macro() pgetc_as_macro()
+#endif
 
 /*
- * Check to see whether we are at the end of the here document.  When this
- * is called, c is set to the first character of the next input line.  If
- * we are at the end of the here document, this routine sets the c to PEOF.
+ * Same as pgetc(), but ignores PEOA.
  */
+#if ENABLE_ASH_ALIAS
+static int
+pgetc2(void)
+{
+       int c;
 
-checkend: {
-       if (eofmark) {
-#ifdef CONFIG_ASH_ALIAS
-               if (c == PEOA) {
-                       c = pgetc2();
-               }
+       do {
+               c = pgetc_macro();
+       } while (c == PEOA);
+       return c;
+}
+#else
+static int
+pgetc2(void)
+{
+       return pgetc_macro();
+}
 #endif
-               if (striptabs) {
-                       while (c == '\t') {
-                               c = pgetc2();
-                       }
-               }
-               if (c == *eofmark) {
-                       if (pfgets(line, sizeof line) != NULL) {
-                               char *p, *q;
 
-                               p = line;
-                               for (q = eofmark + 1 ; *q && *p == *q ; p++, q++);
-                               if (*p == '\n' && *q == '\0') {
-                                       c = PEOF;
-                                       plinno++;
-                                       needprompt = doprompt;
-                               } else {
-                                       pushstring(line, NULL);
-                               }
-                       }
+/*
+ * Read a line from the script.
+ */
+static char *
+pfgets(char *line, int len)
+{
+       char *p = line;
+       int nleft = len;
+       int c;
+
+       while (--nleft > 0) {
+               c = pgetc2();
+               if (c == PEOF) {
+                       if (p == line)
+                               return NULL;
+                       break;
                }
+               *p++ = c;
+               if (c == '\n')
+                       break;
        }
-       goto checkend_return;
+       *p = '\0';
+       return line;
 }
 
+/*
+ * Undo the last call to pgetc.  Only one character may be pushed back.
+ * PEOF may be pushed back.
+ */
+static void
+pungetc(void)
+{
+       parsenleft++;
+       parsenextc--;
+}
 
 /*
- * Parse a redirection operator.  The variable "out" points to a string
- * specifying the fd to be redirected.  The variable "c" contains the
- * first character of the redirection operator.
+ * Push a string back onto the input at this current parsefile level.
+ * We handle aliases this way.
  */
+static void
+pushstring(char *s, void *ap)
+{
+       struct strpush *sp;
+       size_t len;
 
-parseredir: {
-       char fd = *out;
-       union node *np;
+       len = strlen(s);
+       INT_OFF;
+/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
+       if (parsefile->strpush) {
+               sp = ckmalloc(sizeof(struct strpush));
+               sp->prev = parsefile->strpush;
+               parsefile->strpush = sp;
+       } else
+               sp = parsefile->strpush = &(parsefile->basestrpush);
+       sp->prevstring = parsenextc;
+       sp->prevnleft = parsenleft;
+#if ENABLE_ASH_ALIAS
+       sp->ap = (struct alias *)ap;
+       if (ap) {
+               ((struct alias *)ap)->flag |= ALIASINUSE;
+               sp->string = s;
+       }
+#endif
+       parsenextc = s;
+       parsenleft = len;
+       INT_ON;
+}
 
-       np = (union node *)stalloc(sizeof (struct nfile));
-       if (c == '>') {
-               np->nfile.fd = 1;
-               c = pgetc();
-               if (c == '>')
-                       np->type = NAPPEND;
-               else if (c == '|')
-                       np->type = NCLOBBER;
-               else if (c == '&')
-                       np->type = NTOFD;
-               else {
-                       np->type = NTO;
-                       pungetc();
-               }
-       } else {        /* c == '<' */
-               np->nfile.fd = 0;
-               switch (c = pgetc()) {
-               case '<':
-                       if (sizeof (struct nfile) != sizeof (struct nhere)) {
-                               np = (union node *)stalloc(sizeof (struct nhere));
-                               np->nfile.fd = 0;
-                       }
-                       np->type = NHERE;
-                       heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc));
-                       heredoc->here = np;
-                       if ((c = pgetc()) == '-') {
-                               heredoc->striptabs = 1;
-                       } else {
-                               heredoc->striptabs = 0;
-                               pungetc();
-                       }
-                       break;
+/*
+ * To handle the "." command, a stack of input files is used.  Pushfile
+ * adds a new entry to the stack and popfile restores the previous level.
+ */
+static void
+pushfile(void)
+{
+       struct parsefile *pf;
 
-               case '&':
-                       np->type = NFROMFD;
-                       break;
+       parsefile->nleft = parsenleft;
+       parsefile->lleft = parselleft;
+       parsefile->nextc = parsenextc;
+       parsefile->linno = plinno;
+       pf = ckmalloc(sizeof(*pf));
+       pf->prev = parsefile;
+       pf->fd = -1;
+       pf->strpush = NULL;
+       pf->basestrpush.prev = NULL;
+       parsefile = pf;
+}
 
-               case '>':
-                       np->type = NFROMTO;
-                       break;
+static void
+popfile(void)
+{
+       struct parsefile *pf = parsefile;
 
-               default:
-                       np->type = NFROM;
-                       pungetc();
-                       break;
-               }
-       }
-       if (fd != '\0')
-               np->nfile.fd = digit_val(fd);
-       redirnode = np;
-       goto parseredir_return;
+       INT_OFF;
+       if (pf->fd >= 0)
+               close(pf->fd);
+       free(pf->buf);
+       while (pf->strpush)
+               popstring();
+       parsefile = pf->prev;
+       free(pf);
+       parsenleft = parsefile->nleft;
+       parselleft = parsefile->lleft;
+       parsenextc = parsefile->nextc;
+       plinno = parsefile->linno;
+       INT_ON;
 }
 
+/*
+ * Return to top level.
+ */
+static void
+popallfiles(void)
+{
+       while (parsefile != &basepf)
+               popfile();
+}
 
 /*
- * Parse a substitution.  At this point, we have read the dollar sign
- * and nothing else.
+ * Close the file(s) that the shell is reading commands from.  Called
+ * after a fork is done.
  */
+static void
+closescript(void)
+{
+       popallfiles();
+       if (parsefile->fd > 0) {
+               close(parsefile->fd);
+               parsefile->fd = 0;
+       }
+}
 
-parsesub: {
-       int subtype;
-       int typeloc;
-       int flags;
-       char *p;
-       static const char types[] = "}-+?=";
+/*
+ * Like setinputfile, but takes an open file descriptor.  Call this with
+ * interrupts off.
+ */
+static void
+setinputfd(int fd, int push)
+{
+       close_on_exec_on(fd);
+       if (push) {
+               pushfile();
+               parsefile->buf = 0;
+       }
+       parsefile->fd = fd;
+       if (parsefile->buf == NULL)
+               parsefile->buf = ckmalloc(IBUFSIZ);
+       parselleft = parsenleft = 0;
+       plinno = 1;
+}
 
-       c = pgetc();
-       if (
-               c <= PEOA_OR_PEOF  ||
-               (c != '(' && c != '{' && !is_name(c) && !is_special(c))
-       ) {
-               USTPUTC('$', out);
-               pungetc();
-       } else if (c == '(') {  /* $(command) or $((arith)) */
-               if (pgetc() == '(') {
-#ifdef CONFIG_ASH_MATH_SUPPORT
-                       PARSEARITH();
-#else
-                       synerror("We unsupport $((arith))");
-#endif
-               } else {
-                       pungetc();
-                       PARSEBACKQNEW();
-               }
-       } else {
-               USTPUTC(CTLVAR, out);
-               typeloc = out - (char *)stackblock();
-               USTPUTC(VSNORMAL, out);
-               subtype = VSNORMAL;
-               if (c == '{') {
-                       c = pgetc();
-                       if (c == '#') {
-                               if ((c = pgetc()) == '}')
-                                       c = '#';
-                               else
-                                       subtype = VSLENGTH;
-                       }
-                       else
-                               subtype = 0;
-               }
-               if (c > PEOA_OR_PEOF && is_name(c)) {
-                       do {
-                               STPUTC(c, out);
-                               c = pgetc();
-                       } while (c > PEOA_OR_PEOF && is_in_name(c));
-               } else if (is_digit(c)) {
-                       do {
-                               STPUTC(c, out);
-                               c = pgetc();
-                       } while (is_digit(c));
-               }
-               else if (is_special(c)) {
-                       USTPUTC(c, out);
-                       c = pgetc();
-               }
-               else
-badsub:                 synerror("Bad substitution");
+/*
+ * Set the input to take input from a file.  If push is set, push the
+ * old input onto the stack first.
+ */
+static int
+setinputfile(const char *fname, int flags)
+{
+       int fd;
+       int fd2;
 
-               STPUTC('=', out);
-               flags = 0;
-               if (subtype == 0) {
-                       switch (c) {
-                       case ':':
-                               flags = VSNUL;
-                               c = pgetc();
-                               /*FALLTHROUGH*/
-                       default:
-                               p = strchr(types, c);
-                               if (p == NULL)
-                                       goto badsub;
-                               subtype = p - types + VSNORMAL;
-                               break;
-                       case '%':
-                       case '#':
-                               {
-                                       int cc = c;
-                                       subtype = c == '#' ? VSTRIMLEFT :
-                                                            VSTRIMRIGHT;
-                                       c = pgetc();
-                                       if (c == cc)
-                                               subtype++;
-                                       else
-                                               pungetc();
-                                       break;
-                               }
-                       }
-               } else {
-                       pungetc();
-               }
-               if (dblquote || arinest)
-                       flags |= VSQUOTE;
-               *((char *)stackblock() + typeloc) = subtype | flags;
-               if (subtype != VSNORMAL) {
-                       varnest++;
-                       if (dblquote || arinest) {
-                               dqvarnest++;
-                       }
-               }
+       INT_OFF;
+       fd = open(fname, O_RDONLY);
+       if (fd < 0) {
+               if (flags & INPUT_NOFILE_OK)
+                       goto out;
+               ash_msg_and_raise_error("can't open %s", fname);
+       }
+       if (fd < 10) {
+               fd2 = copyfd(fd, 10);
+               close(fd);
+               if (fd2 < 0)
+                       ash_msg_and_raise_error("out of file descriptors");
+               fd = fd2;
        }
-       goto parsesub_return;
+       setinputfd(fd, flags & INPUT_PUSH_FILE);
+ out:
+       INT_ON;
+       return fd;
 }
 
-
 /*
- * Called to parse command substitutions.  Newstyle is set if the command
- * is enclosed inside $(...); nlpp is a pointer to the head of the linked
- * list of commands (passed by reference), and savelen is the number of
- * characters on the top of the stack which must be preserved.
+ * Like setinputfile, but takes input from a string.
  */
+static void
+setinputstring(char *string)
+{
+       INT_OFF;
+       pushfile();
+       parsenextc = string;
+       parsenleft = strlen(string);
+       parsefile->buf = NULL;
+       plinno = 1;
+       INT_ON;
+}
 
-parsebackq: {
-       struct nodelist **nlpp;
-       int savepbq;
-       union node *n;
-       char *volatile str;
-       struct jmploc jmploc;
-       struct jmploc *volatile savehandler;
-       size_t savelen;
-       int saveprompt = 0;
-#ifdef __GNUC__
-       (void) &saveprompt;
-#endif
-
-       savepbq = parsebackquote;
-       if (setjmp(jmploc.loc)) {
-               if (str)
-                       ckfree(str);
-               parsebackquote = 0;
-               handler = savehandler;
-               longjmp(handler->loc, 1);
-       }
-       INTOFF;
-       str = NULL;
-       savelen = out - (char *)stackblock();
-       if (savelen > 0) {
-               str = ckmalloc(savelen);
-               memcpy(str, stackblock(), savelen);
-       }
-       savehandler = handler;
-       handler = &jmploc;
-       INTON;
-       if (oldstyle) {
-               /* We must read until the closing backquote, giving special
-                  treatment to some slashes, and then push the string and
-                  reread it as input, interpreting it normally.  */
-               char *pout;
-               int pc;
-               size_t psavelen;
-               char *pstr;
 
+/* ============ mail.c
+ *
+ * Routines to check for mail.
+ */
 
-               STARTSTACKSTR(pout);
-               for (;;) {
-                       if (needprompt) {
-                               setprompt(2);
-                       }
-                       switch (pc = pgetc()) {
-                       case '`':
-                               goto done;
+#if ENABLE_ASH_MAIL
 
-                       case '\\':
-                               if ((pc = pgetc()) == '\n') {
-                                       plinno++;
-                                       if (doprompt)
-                                               setprompt(2);
-                                       /*
-                                        * If eating a newline, avoid putting
-                                        * the newline into the new character
-                                        * stream (via the STPUTC after the
-                                        * switch).
-                                        */
-                                       continue;
-                               }
-                               if (pc != '\\' && pc != '`' && pc != '$'
-                                   && (!dblquote || pc != '"'))
-                                       STPUTC('\\', pout);
-                               if (pc > PEOA_OR_PEOF) {
-                                       break;
-                               }
-                               /* fall through */
+#define MAXMBOXES 10
 
-                       case PEOF:
-#ifdef CONFIG_ASH_ALIAS
-                       case PEOA:
-#endif
-                               startlinno = plinno;
-                               synerror("EOF in backquote substitution");
+/* times of mailboxes */
+static time_t mailtime[MAXMBOXES];
+/* Set if MAIL or MAILPATH is changed. */
+static smallint mail_var_path_changed;
 
-                       case '\n':
-                               plinno++;
-                               needprompt = doprompt;
-                               break;
+/*
+ * Print appropriate message(s) if mail has arrived.
+ * If mail_var_path_changed is set,
+ * then the value of MAIL has mail_var_path_changed,
+ * so we just update the values.
+ */
+static void
+chkmail(void)
+{
+       const char *mpath;
+       char *p;
+       char *q;
+       time_t *mtp;
+       struct stackmark smark;
+       struct stat statb;
 
-                       default:
-                               break;
-                       }
-                       STPUTC(pc, pout);
+       setstackmark(&smark);
+       mpath = mpathset() ? mpathval() : mailval();
+       for (mtp = mailtime; mtp < mailtime + MAXMBOXES; mtp++) {
+               p = padvance(&mpath, nullstr);
+               if (p == NULL)
+                       break;
+               if (*p == '\0')
+                       continue;
+               for (q = p; *q; q++);
+#if DEBUG
+               if (q[-1] != '/')
+                       abort();
+#endif
+               q[-1] = '\0';                   /* delete trailing '/' */
+               if (stat(p, &statb) < 0) {
+                       *mtp = 0;
+                       continue;
                }
-done:
-               STPUTC('\0', pout);
-               psavelen = pout - (char *)stackblock();
-               if (psavelen > 0) {
-                       pstr = grabstackstr(pout);
-                       setinputstring(pstr);
+               if (!mail_var_path_changed && statb.st_mtime != *mtp) {
+                       fprintf(
+                               stderr, snlfmt,
+                               pathopt ? pathopt : "you have mail"
+                       );
                }
+               *mtp = statb.st_mtime;
        }
-       nlpp = &bqlist;
-       while (*nlpp)
-               nlpp = &(*nlpp)->next;
-       *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist));
-       (*nlpp)->next = NULL;
-       parsebackquote = oldstyle;
+       mail_var_path_changed = 0;
+       popstackmark(&smark);
+}
 
-       if (oldstyle) {
-               saveprompt = doprompt;
-               doprompt = 0;
-       }
+static void
+changemail(const char *val)
+{
+       mail_var_path_changed = 1;
+}
 
-       n = list(2);
+#endif /* ASH_MAIL */
 
-       if (oldstyle)
-               doprompt = saveprompt;
-       else {
-               if (readtoken() != TRP)
-                       synexpect(TRP);
+
+/* ============ ??? */
+
+/*
+ * Set the shell parameters.
+ */
+static void
+setparam(char **argv)
+{
+       char **newparam;
+       char **ap;
+       int nparam;
+
+       for (nparam = 0; argv[nparam]; nparam++);
+       ap = newparam = ckmalloc((nparam + 1) * sizeof(*ap));
+       while (*argv) {
+               *ap++ = ckstrdup(*argv++);
        }
+       *ap = NULL;
+       freeparam(&shellparam);
+       shellparam.malloc = 1;
+       shellparam.nparam = nparam;
+       shellparam.p = newparam;
+#if ENABLE_ASH_GETOPTS
+       shellparam.optind = 1;
+       shellparam.optoff = -1;
+#endif
+}
 
-       (*nlpp)->n = n;
-       if (oldstyle) {
-               /*
-                * Start reading from old file again, ignoring any pushed back
-                * tokens left from the backquote parsing
-                */
-               popfile();
-               tokpushback = 0;
+/*
+ * Process shell options.  The global variable argptr contains a pointer
+ * to the argument list; we advance it past the options.
+ */
+static void
+minus_o(char *name, int val)
+{
+       int i;
+
+       if (name) {
+               for (i = 0; i < NOPTS; i++) {
+                       if (strcmp(name, optnames(i)) == 0) {
+                               optlist[i] = val;
+                               return;
+                       }
+               }
+               ash_msg_and_raise_error("illegal option -o %s", name);
        }
-       while (stackblocksize() <= savelen)
-               growstackblock();
-       STARTSTACKSTR(out);
-       if (str) {
-               memcpy(out, str, savelen);
-               STADJUST(savelen, out);
-               INTOFF;
-               ckfree(str);
-               str = NULL;
-               INTON;
+       out1str("Current option settings\n");
+       for (i = 0; i < NOPTS; i++)
+               out1fmt("%-16s%s\n", optnames(i),
+                               optlist[i] ? "on" : "off");
+}
+static void
+setoption(int flag, int val)
+{
+       int i;
+
+       for (i = 0; i < NOPTS; i++) {
+               if (optletters(i) == flag) {
+                       optlist[i] = val;
+                       return;
+               }
+       }
+       ash_msg_and_raise_error("illegal option -%c", flag);
+       /* NOTREACHED */
+}
+static void
+options(int cmdline)
+{
+       char *p;
+       int val;
+       int c;
+
+       if (cmdline)
+               minusc = NULL;
+       while ((p = *argptr) != NULL) {
+               c = *p++;
+               if (c != '-' && c != '+')
+                       break;
+               argptr++;
+               val = 0; /* val = 0 if c == '+' */
+               if (c == '-') {
+                       val = 1;
+                       if (p[0] == '\0' || LONE_DASH(p)) {
+                               if (!cmdline) {
+                                       /* "-" means turn off -x and -v */
+                                       if (p[0] == '\0')
+                                               xflag = vflag = 0;
+                                       /* "--" means reset params */
+                                       else if (*argptr == NULL)
+                                               setparam(argptr);
+                               }
+                               break;    /* "-" or  "--" terminates options */
+                       }
+               }
+               /* first char was + or - */
+               while ((c = *p++) != '\0') {
+                       /* bash 3.2 indeed handles -c CMD and +c CMD the same */
+                       if (c == 'c' && cmdline) {
+                               minusc = p;     /* command is after shell args */
+                       } else if (c == 'o') {
+                               minus_o(*argptr, val);
+                               if (*argptr)
+                                       argptr++;
+                       } else if (cmdline && (c == 'l')) { /* -l or +l == --login */
+                               isloginsh = 1;
+                       /* bash does not accept +-login, we also won't */
+                       } else if (cmdline && val && (c == '-')) { /* long options */
+                               if (strcmp(p, "login") == 0)
+                                       isloginsh = 1;
+                               break;
+                       } else {
+                               setoption(c, val);
+                       }
+               }
        }
-       parsebackquote = savepbq;
-       handler = savehandler;
-       if (arinest || dblquote)
-               USTPUTC(CTLBACKQ | CTLQUOTE, out);
-       else
-               USTPUTC(CTLBACKQ, out);
-       if (oldstyle)
-               goto parsebackq_oldreturn;
-       else
-               goto parsebackq_newreturn;
 }
 
-#ifdef CONFIG_ASH_MATH_SUPPORT
 /*
- * Parse an arithmetic expansion (indicate start of one and set state)
+ * The shift builtin command.
  */
-parsearith: {
+static int
+shiftcmd(int argc, char **argv)
+{
+       int n;
+       char **ap1, **ap2;
 
-       if (++arinest == 1) {
-               prevsyntax = syntax;
-               syntax = ARISYNTAX;
-               USTPUTC(CTLARI, out);
-               if (dblquote)
-                       USTPUTC('"',out);
-               else
-                       USTPUTC(' ',out);
-       } else {
-               /*
-                * we collapse embedded arithmetic expansion to
-                * parenthesis, which should be equivalent
-                */
-               USTPUTC('(', out);
+       n = 1;
+       if (argc > 1)
+               n = number(argv[1]);
+       if (n > shellparam.nparam)
+               ash_msg_and_raise_error("can't shift that many");
+       INT_OFF;
+       shellparam.nparam -= n;
+       for (ap1 = shellparam.p; --n >= 0; ap1++) {
+               if (shellparam.malloc)
+                       free(*ap1);
        }
-       goto parsearith_return;
-}
+       ap2 = shellparam.p;
+       while ((*ap2++ = *ap1++) != NULL);
+#if ENABLE_ASH_GETOPTS
+       shellparam.optind = 1;
+       shellparam.optoff = -1;
 #endif
-
-} /* end of readtoken */
-
-
+       INT_ON;
+       return 0;
+}
 
 /*
- * Returns true if the text contains nothing to expand (no dollar signs
- * or backquotes).
+ * POSIX requires that 'set' (but not export or readonly) output the
+ * variables in lexicographic order - by the locale's collating order (sigh).
+ * Maybe we could keep them in an ordered balanced binary tree
+ * instead of hashed lists.
+ * For now just roll 'em through qsort for printing...
  */
-
 static int
-noexpand(char *text)
+showvars(const char *sep_prefix, int on, int off)
 {
-       char *p;
-       char c;
-
-       p = text;
-       while ((c = *p++) != '\0') {
-               if (c == CTLQUOTEMARK)
-                       continue;
-               if (c == CTLESC)
-                       p++;
-               else if (SIT(c, BASESYNTAX) == CCTL)
-                       return 0;
-       }
-       return 1;
-}
+       const char *sep;
+       char **ep, **epend;
 
+       ep = listvars(on, off, &epend);
+       qsort(ep, epend - ep, sizeof(char *), vpcmp);
 
-/*
- * Return of a legal variable name (a letter or underscore followed by zero or
- * more letters, underscores, and digits).
- */
+       sep = *sep_prefix ? " " : sep_prefix;
 
-static char *
-endofname(const char *name)
-{
-       char *p;
+       for (; ep < epend; ep++) {
+               const char *p;
+               const char *q;
 
-       p = (char *) name;
-       if (! is_name(*p))
-               return p;
-       while (*++p) {
-               if (! is_in_name(*p))
-                       break;
+               p = strchrnul(*ep, '=');
+               q = nullstr;
+               if (*p)
+                       q = single_quote(++p);
+               out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q);
        }
-       return p;
+       return 0;
 }
 
-
 /*
- * Called when an unexpected token is read during the parse.  The argument
- * is the token that is expected, or -1 if more than one type of token can
- * occur at this point.
+ * The set command builtin.
  */
-
-static void synexpect(int token)
+static int
+setcmd(int argc, char **argv)
 {
-       char msg[64];
-       int l;
-
-       l = sprintf(msg, "%s unexpected", tokname(lasttoken));
-       if (token >= 0)
-               sprintf(msg + l, " (expecting %s)", tokname(token));
-       synerror(msg);
-       /* NOTREACHED */
+       if (argc == 1)
+               return showvars(nullstr, 0, VUNSET);
+       INT_OFF;
+       options(0);
+       optschanged();
+       if (*argptr != NULL) {
+               setparam(argptr);
+       }
+       INT_ON;
+       return 0;
 }
 
+#if ENABLE_ASH_RANDOM_SUPPORT
+/* Roughly copied from bash.. */
 static void
-synerror(const char *msg)
-{
-       sh_error("Syntax error: %s", msg);
-       /* NOTREACHED */
-}
-
-
-/*
- * called by editline -- any expansions to the prompt
- *    should be added here.
- */
-
-#ifdef CONFIG_ASH_EXPAND_PRMT
-static const char *
-expandstr(const char *ps)
+change_random(const char *value)
 {
-       union node n;
-
-       /* XXX Fix (char *) cast. */
-       setinputstring((char *)ps);
-       readtoken1(pgetc(), DQSYNTAX, nullstr, 0);
-       popfile();
-
-       n.narg.type = NARG;
-       n.narg.next = NULL;
-       n.narg.text = wordtext;
-       n.narg.backquote = backquotelist;
+       if (value == NULL) {
+               /* "get", generate */
+               char buf[16];
 
-       expandarg(&n, NULL, 0);
-       return stackblock();
+               rseed = rseed * 1103515245 + 12345;
+               sprintf(buf, "%d", (unsigned int)((rseed & 32767)));
+               /* set without recursion */
+               setvar(vrandom.text, buf, VNOFUNC);
+               vrandom.flags &= ~VNOFUNC;
+       } else {
+               /* set/reset */
+               rseed = strtoul(value, (char **)NULL, 10);
+       }
 }
 #endif
 
-static void setprompt(int whichprompt)
+#if ENABLE_ASH_GETOPTS
+static int
+getopts(char *optstr, char *optvar, char **optfirst, int *param_optind, int *optoff)
 {
-       const char *prompt;
-#ifdef CONFIG_ASH_EXPAND_PRMT
-       struct stackmark smark;
-#endif
+       char *p, *q;
+       char c = '?';
+       int done = 0;
+       int err = 0;
+       char s[12];
+       char **optnext;
 
-       needprompt = 0;
+       if (*param_optind < 1)
+               return 1;
+       optnext = optfirst + *param_optind - 1;
 
-       switch (whichprompt) {
-       case 1:
-               prompt = ps1val();
-               break;
-       case 2:
-               prompt = ps2val();
-               break;
-       default:                        /* 0 */
-               prompt = nullstr;
+       if (*param_optind <= 1 || *optoff < 0 || strlen(optnext[-1]) < *optoff)
+               p = NULL;
+       else
+               p = optnext[-1] + *optoff;
+       if (p == NULL || *p == '\0') {
+               /* Current word is done, advance */
+               p = *optnext;
+               if (p == NULL || *p != '-' || *++p == '\0') {
+ atend:
+                       p = NULL;
+                       done = 1;
+                       goto out;
+               }
+               optnext++;
+               if (LONE_DASH(p))        /* check for "--" */
+                       goto atend;
        }
-#ifdef CONFIG_ASH_EXPAND_PRMT
-       setstackmark(&smark);
-       stalloc(stackblocksize());
-#endif
-       putprompt(expandstr(prompt));
-#ifdef CONFIG_ASH_EXPAND_PRMT
-       popstackmark(&smark);
-#endif
-}
-
-
-static const char *const *findkwd(const char *s)
-{
-       return bsearch(s, tokname_array + KWDOFFSET,
-                      (sizeof(tokname_array) / sizeof(const char *)) - KWDOFFSET,
-                                  sizeof(const char *), pstrcmp);
-}
 
-/*      redir.c      */
+       c = *p++;
+       for (q = optstr; *q != c; ) {
+               if (*q == '\0') {
+                       if (optstr[0] == ':') {
+                               s[0] = c;
+                               s[1] = '\0';
+                               err |= setvarsafe("OPTARG", s, 0);
+                       } else {
+                               fprintf(stderr, "Illegal option -%c\n", c);
+                               unsetvar("OPTARG");
+                       }
+                       c = '?';
+                       goto out;
+               }
+               if (*++q == ':')
+                       q++;
+       }
 
-/*
- * Code for dealing with input/output redirection.
- */
+       if (*++q == ':') {
+               if (*p == '\0' && (p = *optnext) == NULL) {
+                       if (optstr[0] == ':') {
+                               s[0] = c;
+                               s[1] = '\0';
+                               err |= setvarsafe("OPTARG", s, 0);
+                               c = ':';
+                       } else {
+                               fprintf(stderr, "No arg for -%c option\n", c);
+                               unsetvar("OPTARG");
+                               c = '?';
+                       }
+                       goto out;
+               }
 
-#define EMPTY -2                /* marks an unused slot in redirtab */
-#ifndef PIPE_BUF
-# define PIPESIZE 4096          /* amount of buffering in a pipe */
-#else
-# define PIPESIZE PIPE_BUF
-#endif
+               if (p == *optnext)
+                       optnext++;
+               err |= setvarsafe("OPTARG", p, 0);
+               p = NULL;
+       } else
+               err |= setvarsafe("OPTARG", nullstr, 0);
+ out:
+       *optoff = p ? p - *(optnext - 1) : -1;
+       *param_optind = optnext - optfirst + 1;
+       fmtstr(s, sizeof(s), "%d", *param_optind);
+       err |= setvarsafe("OPTIND", s, VNOFUNC);
+       s[0] = c;
+       s[1] = '\0';
+       err |= setvarsafe(optvar, s, 0);
+       if (err) {
+               *param_optind = 1;
+               *optoff = -1;
+               flush_stdout_stderr();
+               raise_exception(EXERROR);
+       }
+       return done;
+}
 
 /*
- * Open a file in noclobber mode.
- * The code was copied from bash.
+ * The getopts builtin.  Shellparam.optnext points to the next argument
+ * to be processed.  Shellparam.optptr points to the next character to
+ * be processed in the current argument.  If shellparam.optnext is NULL,
+ * then it's the first time getopts has been called.
  */
-static int noclobberopen(const char *fname)
+static int
+getoptscmd(int argc, char **argv)
 {
-       int r, fd;
-       struct stat finfo, finfo2;
+       char **optbase;
 
-       /*
-        * If the file exists and is a regular file, return an error
-        * immediately.
-        */
-       r = stat(fname, &finfo);
-       if (r == 0 && S_ISREG(finfo.st_mode)) {
-               errno = EEXIST;
-               return -1;
+       if (argc < 3)
+               ash_msg_and_raise_error("usage: getopts optstring var [arg]");
+       if (argc == 3) {
+               optbase = shellparam.p;
+               if (shellparam.optind > shellparam.nparam + 1) {
+                       shellparam.optind = 1;
+                       shellparam.optoff = -1;
+               }
+       } else {
+               optbase = &argv[3];
+               if (shellparam.optind > argc - 2) {
+                       shellparam.optind = 1;
+                       shellparam.optoff = -1;
+               }
        }
 
-       /*
-        * If the file was not present (r != 0), make sure we open it
-        * exclusively so that if it is created before we open it, our open
-        * will fail.  Make sure that we do not truncate an existing file.
-        * Note that we don't turn on O_EXCL unless the stat failed -- if the
-        * file was not a regular file, we leave O_EXCL off.
-        */
-       if (r != 0)
-               return open(fname, O_WRONLY|O_CREAT|O_EXCL, 0666);
-       fd = open(fname, O_WRONLY|O_CREAT, 0666);
-
-       /* If the open failed, return the file descriptor right away. */
-       if (fd < 0)
-               return fd;
-
-       /*
-        * OK, the open succeeded, but the file may have been changed from a
-        * non-regular file to a regular file between the stat and the open.
-        * We are assuming that the O_EXCL open handles the case where FILENAME
-        * did not exist and is symlinked to an existing file between the stat
-        * and open.
-        */
+       return getopts(argv[1], argv[2], optbase, &shellparam.optind,
+                       &shellparam.optoff);
+}
+#endif /* ASH_GETOPTS */
 
-       /*
-        * If we can open it and fstat the file descriptor, and neither check
-        * revealed that it was a regular file, and the file has not been
-        * replaced, return the file descriptor.
-        */
-        if (fstat(fd, &finfo2) == 0 && !S_ISREG(finfo2.st_mode) &&
-            finfo.st_dev == finfo2.st_dev && finfo.st_ino == finfo2.st_ino)
-               return fd;
 
-       /* The file has been replaced.  badness. */
-       close(fd);
-       errno = EEXIST;
-       return -1;
-}
+/* ============ Shell parser */
 
 /*
- * Handle here documents.  Normally we fork off a process to write the
- * data to a pipe.  If the document is short, we can stuff the data in
- * the pipe without forking.
+ * NEOF is returned by parsecmd when it encounters an end of file.  It
+ * must be distinct from NULL, so we use the address of a variable that
+ * happens to be handy.
  */
+static smallint tokpushback;           /* last token pushed back */
+#define NEOF ((union node *)&tokpushback)
+static smallint parsebackquote;        /* nonzero if we are inside backquotes */
+static int lasttoken;                  /* last token read */
+static char *wordtext;                 /* text of last word returned by readtoken */
+static struct nodelist *backquotelist;
+static union node *redirnode;
+static struct heredoc *heredoc;
+static smallint quoteflag;             /* set if (part of) last token was quoted */
 
-static int openhere(union node *redir)
+static void raise_error_syntax(const char *) ATTRIBUTE_NORETURN;
+static void
+raise_error_syntax(const char *msg)
 {
-       int pip[2];
-       size_t len = 0;
-
-       if (pipe(pip) < 0)
-               sh_error("Pipe call failed");
-       if (redir->type == NHERE) {
-               len = strlen(redir->nhere.doc->narg.text);
-               if (len <= PIPESIZE) {
-                       full_write(pip[1], redir->nhere.doc->narg.text, len);
-                       goto out;
-               }
-       }
-       if (forkshell((struct job *)NULL, (union node *)NULL, FORK_NOJOB) == 0) {
-               close(pip[0]);
-               signal(SIGINT, SIG_IGN);
-               signal(SIGQUIT, SIG_IGN);
-               signal(SIGHUP, SIG_IGN);
-#ifdef SIGTSTP
-               signal(SIGTSTP, SIG_IGN);
-#endif
-               signal(SIGPIPE, SIG_DFL);
-               if (redir->type == NHERE)
-                       full_write(pip[1], redir->nhere.doc->narg.text, len);
-               else
-                       expandhere(redir->nhere.doc, pip[1]);
-               _exit(0);
-       }
-out:
-       close(pip[1]);
-       return pip[0];
+       ash_msg_and_raise_error("syntax error: %s", msg);
+       /* NOTREACHED */
 }
 
-static int
-openredirect(union node *redir)
+/*
+ * Called when an unexpected token is read during the parse.  The argument
+ * is the token that is expected, or -1 if more than one type of token can
+ * occur at this point.
+ */
+static void raise_error_unexpected_syntax(int) ATTRIBUTE_NORETURN;
+static void
+raise_error_unexpected_syntax(int token)
 {
-       char *fname;
-       int f;
-
-       switch (redir->nfile.type) {
-       case NFROM:
-               fname = redir->nfile.expfname;
-               if ((f = open(fname, O_RDONLY)) < 0)
-                       goto eopen;
-               break;
-       case NFROMTO:
-               fname = redir->nfile.expfname;
-               if ((f = open(fname, O_RDWR|O_CREAT|O_TRUNC, 0666)) < 0)
-                       goto ecreate;
-               break;
-       case NTO:
-               /* Take care of noclobber mode. */
-               if (Cflag) {
-                       fname = redir->nfile.expfname;
-                       if ((f = noclobberopen(fname)) < 0)
-                               goto ecreate;
-                       break;
-               }
-               /* FALLTHROUGH */
-       case NCLOBBER:
-               fname = redir->nfile.expfname;
-               if ((f = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0666)) < 0)
-                       goto ecreate;
-               break;
-       case NAPPEND:
-               fname = redir->nfile.expfname;
-               if ((f = open(fname, O_WRONLY|O_CREAT|O_APPEND, 0666)) < 0)
-                       goto ecreate;
-               break;
-       default:
-#if DEBUG
-               abort();
-#endif
-               /* Fall through to eliminate warning. */
-       case NTOFD:
-       case NFROMFD:
-               f = -1;
-               break;
-       case NHERE:
-       case NXHERE:
-               f = openhere(redir);
-               break;
-       }
+       char msg[64];
+       int l;
 
-       return f;
-ecreate:
-       sh_error("cannot create %s: %s", fname, errmsg(errno, E_CREAT));
-eopen:
-       sh_error("cannot open %s: %s", fname, errmsg(errno, E_OPEN));
+       l = sprintf(msg, "%s unexpected", tokname(lasttoken));
+       if (token >= 0)
+               sprintf(msg + l, " (expecting %s)", tokname(token));
+       raise_error_syntax(msg);
+       /* NOTREACHED */
 }
 
-static void dupredirect(union node *redir, int f)
-{
-       int fd = redir->nfile.fd;
+#define EOFMARKLEN 79
 
-       if (redir->nfile.type == NTOFD || redir->nfile.type == NFROMFD) {
-               if (redir->ndup.dupfd >= 0) {   /* if not ">&-" */
-                               copyfd(redir->ndup.dupfd, fd);
-               }
-               return;
-       }
+struct heredoc {
+       struct heredoc *next;   /* next here document in list */
+       union node *here;               /* redirection node */
+       char *eofmark;          /* string indicating end of input */
+       int striptabs;          /* if set, strip leading tabs */
+};
 
-       if (f != fd) {
-               copyfd(f, fd);
-               close(f);
-       }
-       return;
-}
+static struct heredoc *heredoclist;    /* list of here documents to read */
 
-/*
- * Process a list of redirection commands.  If the REDIR_PUSH flag is set,
- * old file descriptors are stashed away so that the redirection can be
- * undone by calling popredir.  If the REDIR_BACKQ flag is set, then the
- * standard output, and the standard error if it becomes a duplicate of
- * stdout, is saved in memory.
- */
+/* parsing is heavily cross-recursive, need these forward decls */
+static union node *andor(void);
+static union node *pipeline(void);
+static union node *parse_command(void);
+static void parseheredoc(void);
+static char peektoken(void);
+static int readtoken(void);
 
-static void
-redirect(union node *redir, int flags)
+static union node *
+list(int nlflag)
 {
-       union node *n;
-       struct redirtab *sv;
-       int i;
-       int fd;
-       int newfd;
-       int *p;
-       nullredirs++;
-       if (!redir) {
-               return;
-       }
-       sv = NULL;
-       INTOFF;
-       if (flags & REDIR_PUSH) {
-               struct redirtab *q;
-               q = ckmalloc(sizeof (struct redirtab));
-               q->next = redirlist;
-               redirlist = q;
-               q->nullredirs = nullredirs - 1;
-               for (i = 0 ; i < 10 ; i++)
-                       q->renamed[i] = EMPTY;
-               nullredirs = 0;
-               sv = q;
-       }
-       n = redir;
-       do {
-               fd = n->nfile.fd;
-               if ((n->nfile.type == NTOFD || n->nfile.type == NFROMFD) &&
-                   n->ndup.dupfd == fd)
-                       continue; /* redirect from/to same file descriptor */
-
-               newfd = openredirect(n);
-               if (fd == newfd)
-                       continue;
-               if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
-                       i = fcntl(fd, F_DUPFD, 10);
+       union node *n1, *n2, *n3;
+       int tok;
 
-                       if (i == -1) {
-                               i = errno;
-                               if (i != EBADF) {
-                                       close(newfd);
-                                       errno = i;
-                                       sh_error("%d: %m", fd);
-                                       /* NOTREACHED */
+       checkkwd = CHKNL | CHKKWD | CHKALIAS;
+       if (nlflag == 2 && peektoken())
+               return NULL;
+       n1 = NULL;
+       for (;;) {
+               n2 = andor();
+               tok = readtoken();
+               if (tok == TBACKGND) {
+                       if (n2->type == NPIPE) {
+                               n2->npipe.backgnd = 1;
+                       } else {
+                               if (n2->type != NREDIR) {
+                                       n3 = stalloc(sizeof(struct nredir));
+                                       n3->nredir.n = n2;
+                                       n3->nredir.redirect = NULL;
+                                       n2 = n3;
                                }
-                       } else {
-                               *p = i;
-                               close(fd);
+                               n2->type = NBACKGND;
                        }
+               }
+               if (n1 == NULL) {
+                       n1 = n2;
                } else {
-                       close(fd);
+                       n3 = stalloc(sizeof(struct nbinary));
+                       n3->type = NSEMI;
+                       n3->nbinary.ch1 = n1;
+                       n3->nbinary.ch2 = n2;
+                       n1 = n3;
                }
-               dupredirect(n, newfd);
-       } while ((n = n->nfile.next));
-       INTON;
-       if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
-               preverrout_fd = sv->renamed[2];
+               switch (tok) {
+               case TBACKGND:
+               case TSEMI:
+                       tok = readtoken();
+                       /* fall through */
+               case TNL:
+                       if (tok == TNL) {
+                               parseheredoc();
+                               if (nlflag == 1)
+                                       return n1;
+                       } else {
+                               tokpushback = 1;
+                       }
+                       checkkwd = CHKNL | CHKKWD | CHKALIAS;
+                       if (peektoken())
+                               return n1;
+                       break;
+               case TEOF:
+                       if (heredoclist)
+                               parseheredoc();
+                       else
+                               pungetc();              /* push back EOF on input */
+                       return n1;
+               default:
+                       if (nlflag == 1)
+                               raise_error_unexpected_syntax(-1);
+                       tokpushback = 1;
+                       return n1;
+               }
+       }
 }
 
+static union node *
+andor(void)
+{
+       union node *n1, *n2, *n3;
+       int t;
 
-/*
- * Undo the effects of the last redirection.
- */
+       n1 = pipeline();
+       for (;;) {
+               t = readtoken();
+               if (t == TAND) {
+                       t = NAND;
+               } else if (t == TOR) {
+                       t = NOR;
+               } else {
+                       tokpushback = 1;
+                       return n1;
+               }
+               checkkwd = CHKNL | CHKKWD | CHKALIAS;
+               n2 = pipeline();
+               n3 = stalloc(sizeof(struct nbinary));
+               n3->type = t;
+               n3->nbinary.ch1 = n1;
+               n3->nbinary.ch2 = n2;
+               n1 = n3;
+       }
+}
 
-void
-popredir(int drop)
+static union node *
+pipeline(void)
 {
-       struct redirtab *rp;
-       int i;
+       union node *n1, *n2, *pipenode;
+       struct nodelist *lp, *prev;
+       int negate;
 
-       if (--nullredirs >= 0)
-               return;
-       INTOFF;
-       rp = redirlist;
-       for (i = 0 ; i < 10 ; i++) {
-               if (rp->renamed[i] != EMPTY) {
-                       if (!drop) {
-                               close(i);
-                               copyfd(rp->renamed[i], i);
-                       }
-                       close(rp->renamed[i]);
-               }
+       negate = 0;
+       TRACE(("pipeline: entered\n"));
+       if (readtoken() == TNOT) {
+               negate = !negate;
+               checkkwd = CHKKWD | CHKALIAS;
+       } else
+               tokpushback = 1;
+       n1 = parse_command();
+       if (readtoken() == TPIPE) {
+               pipenode = stalloc(sizeof(struct npipe));
+               pipenode->type = NPIPE;
+               pipenode->npipe.backgnd = 0;
+               lp = stalloc(sizeof(struct nodelist));
+               pipenode->npipe.cmdlist = lp;
+               lp->n = n1;
+               do {
+                       prev = lp;
+                       lp = stalloc(sizeof(struct nodelist));
+                       checkkwd = CHKNL | CHKKWD | CHKALIAS;
+                       lp->n = parse_command();
+                       prev->next = lp;
+               } while (readtoken() == TPIPE);
+               lp->next = NULL;
+               n1 = pipenode;
        }
-       redirlist = rp->next;
-       nullredirs = rp->nullredirs;
-       ckfree(rp);
-       INTON;
+       tokpushback = 1;
+       if (negate) {
+               n2 = stalloc(sizeof(struct nnot));
+               n2->type = NNOT;
+               n2->nnot.com = n1;
+               return n2;
+       }
+       return n1;
 }
 
-/*
- * Undo all redirections.  Called on error or interrupt.
- */
+static union node *
+makename(void)
+{
+       union node *n;
 
-/*
- * Discard all saved file descriptors.
- */
+       n = stalloc(sizeof(struct narg));
+       n->type = NARG;
+       n->narg.next = NULL;
+       n->narg.text = wordtext;
+       n->narg.backquote = backquotelist;
+       return n;
+}
 
-void
-clearredir(int drop)
+static void
+fixredir(union node *n, const char *text, int err)
 {
-       for (;;) {
-               nullredirs = 0;
-               if (!redirlist)
-                       break;
-               popredir(drop);
+       TRACE(("Fix redir %s %d\n", text, err));
+       if (!err)
+               n->ndup.vname = NULL;
+
+       if (isdigit(text[0]) && text[1] == '\0')
+               n->ndup.dupfd = text[0] - '0';
+       else if (LONE_DASH(text))
+               n->ndup.dupfd = -1;
+       else {
+               if (err)
+                       raise_error_syntax("Bad fd number");
+               n->ndup.vname = makename();
        }
 }
 
-
 /*
- * Copy a file descriptor to be >= to.  Returns -1
- * if the source file descriptor is closed, EMPTY if there are no unused
- * file descriptors left.
+ * Returns true if the text contains nothing to expand (no dollar signs
+ * or backquotes).
  */
-
-int
-copyfd(int from, int to)
+static int
+noexpand(char *text)
 {
-       int newfd;
+       char *p;
+       char c;
 
-       newfd = fcntl(from, F_DUPFD, to);
-       if (newfd < 0) {
-               if (errno == EMFILE)
-                       return EMPTY;
-               else
-                       sh_error("%d: %m", from);
+       p = text;
+       while ((c = *p++) != '\0') {
+               if (c == CTLQUOTEMARK)
+                       continue;
+               if (c == CTLESC)
+                       p++;
+               else if (SIT(c, BASESYNTAX) == CCTL)
+                       return 0;
        }
-       return newfd;
+       return 1;
 }
 
-
-int
-redirectsafe(union node *redir, int flags)
+static void
+parsefname(void)
 {
-       int err;
-       volatile int saveint;
-       struct jmploc *volatile savehandler = handler;
-       struct jmploc jmploc;
+       union node *n = redirnode;
 
-       SAVEINT(saveint);
-       if (!(err = setjmp(jmploc.loc) * 2)) {
-               handler = &jmploc;
-               redirect(redir, flags);
+       if (readtoken() != TWORD)
+               raise_error_unexpected_syntax(-1);
+       if (n->type == NHERE) {
+               struct heredoc *here = heredoc;
+               struct heredoc *p;
+               int i;
+
+               if (quoteflag == 0)
+                       n->type = NXHERE;
+               TRACE(("Here document %d\n", n->type));
+               if (!noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN)
+                       raise_error_syntax("Illegal eof marker for << redirection");
+               rmescapes(wordtext);
+               here->eofmark = wordtext;
+               here->next = NULL;
+               if (heredoclist == NULL)
+                       heredoclist = here;
+               else {
+                       for (p = heredoclist; p->next; p = p->next);
+                       p->next = here;
+               }
+       } else if (n->type == NTOFD || n->type == NFROMFD) {
+               fixredir(n, wordtext, 0);
+       } else {
+               n->nfile.fname = makename();
        }
-       handler = savehandler;
-       if (err && exception != EXERROR)
-               longjmp(handler->loc, 1);
-       RESTOREINT(saveint);
-       return err;
 }
 
-/*      show.c    */
+static union node *
+simplecmd(void)
+{
+       union node *args, **app;
+       union node *n = NULL;
+       union node *vars, **vpp;
+       union node **rpp, *redir;
+       int savecheckkwd;
 
-#if DEBUG
-static void shtree(union node *, int, char *, FILE*);
-static void shcmd(union node *, FILE *);
-static void sharg(union node *, FILE *);
-static void indent(int, char *, FILE *);
-static void trstring(char *);
+       args = NULL;
+       app = &args;
+       vars = NULL;
+       vpp = &vars;
+       redir = NULL;
+       rpp = &redir;
 
+       savecheckkwd = CHKALIAS;
+       for (;;) {
+               checkkwd = savecheckkwd;
+               switch (readtoken()) {
+               case TWORD:
+                       n = stalloc(sizeof(struct narg));
+                       n->type = NARG;
+                       n->narg.text = wordtext;
+                       n->narg.backquote = backquotelist;
+                       if (savecheckkwd && isassignment(wordtext)) {
+                               *vpp = n;
+                               vpp = &n->narg.next;
+                       } else {
+                               *app = n;
+                               app = &n->narg.next;
+                               savecheckkwd = 0;
+                       }
+                       break;
+               case TREDIR:
+                       *rpp = n = redirnode;
+                       rpp = &n->nfile.next;
+                       parsefname();   /* read name of redirection file */
+                       break;
+               case TLP:
+                       if (args && app == &args->narg.next
+                        && !vars && !redir
+                       ) {
+                               struct builtincmd *bcmd;
+                               const char *name;
 
-void
-showtree(union node *n)
-{
-       trputs("showtree called\n");
-       shtree(n, 1, NULL, stdout);
+                               /* We have a function */
+                               if (readtoken() != TRP)
+                                       raise_error_unexpected_syntax(TRP);
+                               name = n->narg.text;
+                               if (!goodname(name)
+                                || ((bcmd = find_builtin(name)) && IS_BUILTIN_SPECIAL(bcmd))
+                               ) {
+                                       raise_error_syntax("Bad function name");
+                               }
+                               n->type = NDEFUN;
+                               checkkwd = CHKNL | CHKKWD | CHKALIAS;
+                               n->narg.next = parse_command();
+                               return n;
+                       }
+                       /* fall through */
+               default:
+                       tokpushback = 1;
+                       goto out;
+               }
+       }
+ out:
+       *app = NULL;
+       *vpp = NULL;
+       *rpp = NULL;
+       n = stalloc(sizeof(struct ncmd));
+       n->type = NCMD;
+       n->ncmd.args = args;
+       n->ncmd.assign = vars;
+       n->ncmd.redirect = redir;
+       return n;
 }
 
-
-static void
-shtree(union node *n, int ind, char *pfx, FILE *fp)
+static union node *
+parse_command(void)
 {
-       struct nodelist *lp;
-       const char *s;
+       union node *n1, *n2;
+       union node *ap, **app;
+       union node *cp, **cpp;
+       union node *redir, **rpp;
+       union node **rpp2;
+       int t;
 
-       if (n == NULL)
-               return;
+       redir = NULL;
+       rpp2 = &redir;
 
-       indent(ind, pfx, fp);
-       switch(n->type) {
-       case NSEMI:
-               s = "; ";
-               goto binop;
-       case NAND:
-               s = " && ";
-               goto binop;
-       case NOR:
-               s = " || ";
-binop:
-               shtree(n->nbinary.ch1, ind, NULL, fp);
-          /*    if (ind < 0) */
-                       fputs(s, fp);
-               shtree(n->nbinary.ch2, ind, NULL, fp);
+       switch (readtoken()) {
+       default:
+               raise_error_unexpected_syntax(-1);
+               /* NOTREACHED */
+       case TIF:
+               n1 = stalloc(sizeof(struct nif));
+               n1->type = NIF;
+               n1->nif.test = list(0);
+               if (readtoken() != TTHEN)
+                       raise_error_unexpected_syntax(TTHEN);
+               n1->nif.ifpart = list(0);
+               n2 = n1;
+               while (readtoken() == TELIF) {
+                       n2->nif.elsepart = stalloc(sizeof(struct nif));
+                       n2 = n2->nif.elsepart;
+                       n2->type = NIF;
+                       n2->nif.test = list(0);
+                       if (readtoken() != TTHEN)
+                               raise_error_unexpected_syntax(TTHEN);
+                       n2->nif.ifpart = list(0);
+               }
+               if (lasttoken == TELSE)
+                       n2->nif.elsepart = list(0);
+               else {
+                       n2->nif.elsepart = NULL;
+                       tokpushback = 1;
+               }
+               t = TFI;
                break;
-       case NCMD:
-               shcmd(n, fp);
-               if (ind >= 0)
-                       putc('\n', fp);
+       case TWHILE:
+       case TUNTIL: {
+               int got;
+               n1 = stalloc(sizeof(struct nbinary));
+               n1->type = (lasttoken == TWHILE) ? NWHILE : NUNTIL;
+               n1->nbinary.ch1 = list(0);
+               got = readtoken();
+               if (got != TDO) {
+                       TRACE(("expecting DO got %s %s\n", tokname(got),
+                                       got == TWORD ? wordtext : ""));
+                       raise_error_unexpected_syntax(TDO);
+               }
+               n1->nbinary.ch2 = list(0);
+               t = TDONE;
                break;
-       case NPIPE:
-               for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
-                       shcmd(lp->n, fp);
-                       if (lp->next)
-                               fputs(" | ", fp);
+       }
+       case TFOR:
+               if (readtoken() != TWORD || quoteflag || ! goodname(wordtext))
+                       raise_error_syntax("Bad for loop variable");
+               n1 = stalloc(sizeof(struct nfor));
+               n1->type = NFOR;
+               n1->nfor.var = wordtext;
+               checkkwd = CHKKWD | CHKALIAS;
+               if (readtoken() == TIN) {
+                       app = &ap;
+                       while (readtoken() == TWORD) {
+                               n2 = stalloc(sizeof(struct narg));
+                               n2->type = NARG;
+                               n2->narg.text = wordtext;
+                               n2->narg.backquote = backquotelist;
+                               *app = n2;
+                               app = &n2->narg.next;
+                       }
+                       *app = NULL;
+                       n1->nfor.args = ap;
+                       if (lasttoken != TNL && lasttoken != TSEMI)
+                               raise_error_unexpected_syntax(-1);
+               } else {
+                       n2 = stalloc(sizeof(struct narg));
+                       n2->type = NARG;
+                       n2->narg.text = (char *)dolatstr;
+                       n2->narg.backquote = NULL;
+                       n2->narg.next = NULL;
+                       n1->nfor.args = n2;
+                       /*
+                        * Newline or semicolon here is optional (but note
+                        * that the original Bourne shell only allowed NL).
+                        */
+                       if (lasttoken != TNL && lasttoken != TSEMI)
+                               tokpushback = 1;
                }
-               if (n->npipe.backgnd)
-                       fputs(" &", fp);
-               if (ind >= 0)
-                       putc('\n', fp);
+               checkkwd = CHKNL | CHKKWD | CHKALIAS;
+               if (readtoken() != TDO)
+                       raise_error_unexpected_syntax(TDO);
+               n1->nfor.body = list(0);
+               t = TDONE;
                break;
-       default:
-               fprintf(fp, "<node type %d>", n->type);
-               if (ind >= 0)
-                       putc('\n', fp);
+       case TCASE:
+               n1 = stalloc(sizeof(struct ncase));
+               n1->type = NCASE;
+               if (readtoken() != TWORD)
+                       raise_error_unexpected_syntax(TWORD);
+               n1->ncase.expr = n2 = stalloc(sizeof(struct narg));
+               n2->type = NARG;
+               n2->narg.text = wordtext;
+               n2->narg.backquote = backquotelist;
+               n2->narg.next = NULL;
+               do {
+                       checkkwd = CHKKWD | CHKALIAS;
+               } while (readtoken() == TNL);
+               if (lasttoken != TIN)
+                       raise_error_unexpected_syntax(TIN);
+               cpp = &n1->ncase.cases;
+ next_case:
+               checkkwd = CHKNL | CHKKWD;
+               t = readtoken();
+               while (t != TESAC) {
+                       if (lasttoken == TLP)
+                               readtoken();
+                       *cpp = cp = stalloc(sizeof(struct nclist));
+                       cp->type = NCLIST;
+                       app = &cp->nclist.pattern;
+                       for (;;) {
+                               *app = ap = stalloc(sizeof(struct narg));
+                               ap->type = NARG;
+                               ap->narg.text = wordtext;
+                               ap->narg.backquote = backquotelist;
+                               if (readtoken() != TPIPE)
+                                       break;
+                               app = &ap->narg.next;
+                               readtoken();
+                       }
+                       ap->narg.next = NULL;
+                       if (lasttoken != TRP)
+                               raise_error_unexpected_syntax(TRP);
+                       cp->nclist.body = list(2);
+
+                       cpp = &cp->nclist.next;
+
+                       checkkwd = CHKNL | CHKKWD;
+                       t = readtoken();
+                       if (t != TESAC) {
+                               if (t != TENDCASE)
+                                       raise_error_unexpected_syntax(TENDCASE);
+                               goto next_case;
+                       }
+               }
+               *cpp = NULL;
+               goto redir;
+       case TLP:
+               n1 = stalloc(sizeof(struct nredir));
+               n1->type = NSUBSHELL;
+               n1->nredir.n = list(0);
+               n1->nredir.redirect = NULL;
+               t = TRP;
+               break;
+       case TBEGIN:
+               n1 = list(0);
+               t = TEND;
                break;
+       case TWORD:
+       case TREDIR:
+               tokpushback = 1;
+               return simplecmd();
        }
-}
 
+       if (readtoken() != t)
+               raise_error_unexpected_syntax(t);
 
-static void
-shcmd(union node *cmd, FILE *fp)
-{
-       union node *np;
-       int first;
-       const char *s;
-       int dftfd;
-
-       first = 1;
-       for (np = cmd->ncmd.args ; np ; np = np->narg.next) {
-               if (! first)
-                       putchar(' ');
-               sharg(np, fp);
-               first = 0;
+ redir:
+       /* Now check for redirection which may follow command */
+       checkkwd = CHKKWD | CHKALIAS;
+       rpp = rpp2;
+       while (readtoken() == TREDIR) {
+               *rpp = n2 = redirnode;
+               rpp = &n2->nfile.next;
+               parsefname();
        }
-       for (np = cmd->ncmd.redirect ; np ; np = np->nfile.next) {
-               if (! first)
-                       putchar(' ');
-               switch (np->nfile.type) {
-                       case NTO:       s = ">";  dftfd = 1; break;
-                       case NCLOBBER:  s = ">|"; dftfd = 1; break;
-                       case NAPPEND:   s = ">>"; dftfd = 1; break;
-                       case NTOFD:     s = ">&"; dftfd = 1; break;
-                       case NFROM:     s = "<";  dftfd = 0; break;
-                       case NFROMFD:   s = "<&"; dftfd = 0; break;
-                       case NFROMTO:   s = "<>"; dftfd = 0; break;
-                       default:        s = "*error*"; dftfd = 0; break;
-               }
-               if (np->nfile.fd != dftfd)
-                       fprintf(fp, "%d", np->nfile.fd);
-               fputs(s, fp);
-               if (np->nfile.type == NTOFD || np->nfile.type == NFROMFD) {
-                       fprintf(fp, "%d", np->ndup.dupfd);
-               } else {
-                       sharg(np->nfile.fname, fp);
+       tokpushback = 1;
+       *rpp = NULL;
+       if (redir) {
+               if (n1->type != NSUBSHELL) {
+                       n2 = stalloc(sizeof(struct nredir));
+                       n2->type = NREDIR;
+                       n2->nredir.n = n1;
+                       n1 = n2;
                }
-               first = 0;
+               n1->nredir.redirect = redir;
        }
+       return n1;
 }
 
+/*
+ * If eofmark is NULL, read a word or a redirection symbol.  If eofmark
+ * is not NULL, read a here document.  In the latter case, eofmark is the
+ * word which marks the end of the document and striptabs is true if
+ * leading tabs should be stripped from the document.  The argument firstc
+ * is the first character of the input token or document.
+ *
+ * Because C does not have internal subroutines, I have simulated them
+ * using goto's to implement the subroutine linkage.  The following macros
+ * will run code that appears at the end of readtoken1.
+ */
 
+#define CHECKEND()      {goto checkend; checkend_return:;}
+#define PARSEREDIR()    {goto parseredir; parseredir_return:;}
+#define PARSESUB()      {goto parsesub; parsesub_return:;}
+#define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;}
+#define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;}
+#define PARSEARITH()    {goto parsearith; parsearith_return:;}
 
-static void
-sharg(union node *arg, FILE *fp)
+static int
+readtoken1(int firstc, int syntax, char *eofmark, int striptabs)
 {
-       char *p;
+       /* NB: syntax parameter fits into smallint */
+       int c = firstc;
+       char *out;
+       int len;
+       char line[EOFMARKLEN + 1];
        struct nodelist *bqlist;
-       int subtype;
-
-       if (arg->type != NARG) {
-               out1fmt("<node type %d>\n", arg->type);
-               abort();
-       }
-       bqlist = arg->narg.backquote;
-       for (p = arg->narg.text ; *p ; p++) {
-               switch (*p) {
-               case CTLESC:
-                       putc(*++p, fp);
-                       break;
-               case CTLVAR:
-                       putc('$', fp);
-                       putc('{', fp);
-                       subtype = *++p;
-                       if (subtype == VSLENGTH)
-                               putc('#', fp);
-
-                       while (*p != '=')
-                               putc(*p++, fp);
+       smallint quotef;
+       smallint dblquote;
+       smallint oldstyle;
+       smallint prevsyntax; /* syntax before arithmetic */
+#if ENABLE_ASH_EXPAND_PRMT
+       smallint pssyntax;   /* we are expanding a prompt string */
+#endif
+       int varnest;         /* levels of variables expansion */
+       int arinest;         /* levels of arithmetic expansion */
+       int parenlevel;      /* levels of parens in arithmetic */
+       int dqvarnest;       /* levels of variables expansion within double quotes */
 
-                       if (subtype & VSNUL)
-                               putc(':', fp);
+#if __GNUC__
+       /* Avoid longjmp clobbering */
+       (void) &out;
+       (void) &quotef;
+       (void) &dblquote;
+       (void) &varnest;
+       (void) &arinest;
+       (void) &parenlevel;
+       (void) &dqvarnest;
+       (void) &oldstyle;
+       (void) &prevsyntax;
+       (void) &syntax;
+#endif
+       startlinno = plinno;
+       bqlist = NULL;
+       quotef = 0;
+       oldstyle = 0;
+       prevsyntax = 0;
+#if ENABLE_ASH_EXPAND_PRMT
+       pssyntax = (syntax == PSSYNTAX);
+       if (pssyntax)
+               syntax = DQSYNTAX;
+#endif
+       dblquote = (syntax == DQSYNTAX);
+       varnest = 0;
+       arinest = 0;
+       parenlevel = 0;
+       dqvarnest = 0;
 
-                       switch (subtype & VSTYPE) {
-                       case VSNORMAL:
-                               putc('}', fp);
+       STARTSTACKSTR(out);
+       loop: { /* for each line, until end of word */
+               CHECKEND();     /* set c to PEOF if at end of here document */
+               for (;;) {      /* until end of line or end of word */
+                       CHECKSTRSPACE(4, out);  /* permit 4 calls to USTPUTC */
+                       switch (SIT(c, syntax)) {
+                       case CNL:       /* '\n' */
+                               if (syntax == BASESYNTAX)
+                                       goto endword;   /* exit outer loop */
+                               USTPUTC(c, out);
+                               plinno++;
+                               if (doprompt)
+                                       setprompt(2);
+                               c = pgetc();
+                               goto loop;              /* continue outer loop */
+                       case CWORD:
+                               USTPUTC(c, out);
                                break;
-                       case VSMINUS:
-                               putc('-', fp);
+                       case CCTL:
+                               if (eofmark == NULL || dblquote)
+                                       USTPUTC(CTLESC, out);
+                               USTPUTC(c, out);
                                break;
-                       case VSPLUS:
-                               putc('+', fp);
+                       case CBACK:     /* backslash */
+                               c = pgetc2();
+                               if (c == PEOF) {
+                                       USTPUTC(CTLESC, out);
+                                       USTPUTC('\\', out);
+                                       pungetc();
+                               } else if (c == '\n') {
+                                       if (doprompt)
+                                               setprompt(2);
+                               } else {
+#if ENABLE_ASH_EXPAND_PRMT
+                                       if (c == '$' && pssyntax) {
+                                               USTPUTC(CTLESC, out);
+                                               USTPUTC('\\', out);
+                                       }
+#endif
+                                       if (dblquote &&
+                                               c != '\\' && c != '`' &&
+                                               c != '$' && (
+                                                       c != '"' ||
+                                                       eofmark != NULL)
+                                       ) {
+                                               USTPUTC(CTLESC, out);
+                                               USTPUTC('\\', out);
+                                       }
+                                       if (SIT(c, SQSYNTAX) == CCTL)
+                                               USTPUTC(CTLESC, out);
+                                       USTPUTC(c, out);
+                                       quotef = 1;
+                               }
                                break;
-                       case VSQUESTION:
-                               putc('?', fp);
+                       case CSQUOTE:
+                               syntax = SQSYNTAX;
+ quotemark:
+                               if (eofmark == NULL) {
+                                       USTPUTC(CTLQUOTEMARK, out);
+                               }
                                break;
-                       case VSASSIGN:
-                               putc('=', fp);
+                       case CDQUOTE:
+                               syntax = DQSYNTAX;
+                               dblquote = 1;
+                               goto quotemark;
+                       case CENDQUOTE:
+                               if (eofmark != NULL && arinest == 0
+                                && varnest == 0
+                               ) {
+                                       USTPUTC(c, out);
+                               } else {
+                                       if (dqvarnest == 0) {
+                                               syntax = BASESYNTAX;
+                                               dblquote = 0;
+                                       }
+                                       quotef = 1;
+                                       goto quotemark;
+                               }
                                break;
-                       case VSTRIMLEFT:
-                               putc('#', fp);
+                       case CVAR:      /* '$' */
+                               PARSESUB();             /* parse substitution */
                                break;
-                       case VSTRIMLEFTMAX:
-                               putc('#', fp);
-                               putc('#', fp);
+                       case CENDVAR:   /* '}' */
+                               if (varnest > 0) {
+                                       varnest--;
+                                       if (dqvarnest > 0) {
+                                               dqvarnest--;
+                                       }
+                                       USTPUTC(CTLENDVAR, out);
+                               } else {
+                                       USTPUTC(c, out);
+                               }
                                break;
-                       case VSTRIMRIGHT:
-                               putc('%', fp);
+#if ENABLE_ASH_MATH_SUPPORT
+                       case CLP:       /* '(' in arithmetic */
+                               parenlevel++;
+                               USTPUTC(c, out);
                                break;
-                       case VSTRIMRIGHTMAX:
-                               putc('%', fp);
-                               putc('%', fp);
+                       case CRP:       /* ')' in arithmetic */
+                               if (parenlevel > 0) {
+                                       USTPUTC(c, out);
+                                       --parenlevel;
+                               } else {
+                                       if (pgetc() == ')') {
+                                               if (--arinest == 0) {
+                                                       USTPUTC(CTLENDARI, out);
+                                                       syntax = prevsyntax;
+                                                       dblquote = (syntax == DQSYNTAX);
+                                               } else
+                                                       USTPUTC(')', out);
+                                       } else {
+                                               /*
+                                                * unbalanced parens
+                                                *  (don't 2nd guess - no error)
+                                                */
+                                               pungetc();
+                                               USTPUTC(')', out);
+                                       }
+                               }
                                break;
-                       case VSLENGTH:
+#endif
+                       case CBQUOTE:   /* '`' */
+                               PARSEBACKQOLD();
+                               break;
+                       case CENDFILE:
+                               goto endword;           /* exit outer loop */
+                       case CIGN:
                                break;
                        default:
-                               out1fmt("<subtype %d>", subtype);
+                               if (varnest == 0)
+                                       goto endword;   /* exit outer loop */
+#if ENABLE_ASH_ALIAS
+                               if (c != PEOA)
+#endif
+                                       USTPUTC(c, out);
+
                        }
-                       break;
-               case CTLENDVAR:
-                    putc('}', fp);
-                    break;
-               case CTLBACKQ:
-               case CTLBACKQ|CTLQUOTE:
-                       putc('$', fp);
-                       putc('(', fp);
-                       shtree(bqlist->n, -1, NULL, fp);
-                       putc(')', fp);
-                       break;
-               default:
-                       putc(*p, fp);
-                       break;
+                       c = pgetc_macro();
                }
        }
-}
-
-
-static void
-indent(int amount, char *pfx, FILE *fp)
-{
-       int i;
-
-       for (i = 0 ; i < amount ; i++) {
-               if (pfx && i == amount - 1)
-                       fputs(pfx, fp);
-               putc('\t', fp);
+ endword:
+#if ENABLE_ASH_MATH_SUPPORT
+       if (syntax == ARISYNTAX)
+               raise_error_syntax("Missing '))'");
+#endif
+       if (syntax != BASESYNTAX && !parsebackquote && eofmark == NULL)
+               raise_error_syntax("Unterminated quoted string");
+       if (varnest != 0) {
+               startlinno = plinno;
+               /* { */
+               raise_error_syntax("Missing '}'");
        }
-}
-
-
+       USTPUTC('\0', out);
+       len = out - (char *)stackblock();
+       out = stackblock();
+       if (eofmark == NULL) {
+               if ((c == '>' || c == '<')
+                && quotef == 0
+                && len <= 2
+                && (*out == '\0' || isdigit(*out))) {
+                       PARSEREDIR();
+                       return lasttoken = TREDIR;
+               } else {
+                       pungetc();
+               }
+       }
+       quoteflag = quotef;
+       backquotelist = bqlist;
+       grabstackblock(len);
+       wordtext = out;
+       lasttoken = TWORD;
+       return lasttoken;
+/* end of readtoken routine */
 
 /*
- * Debugging stuff.
+ * Check to see whether we are at the end of the here document.  When this
+ * is called, c is set to the first character of the next input line.  If
+ * we are at the end of the here document, this routine sets the c to PEOF.
  */
+checkend: {
+       if (eofmark) {
+#if ENABLE_ASH_ALIAS
+               if (c == PEOA) {
+                       c = pgetc2();
+               }
+#endif
+               if (striptabs) {
+                       while (c == '\t') {
+                               c = pgetc2();
+                       }
+               }
+               if (c == *eofmark) {
+                       if (pfgets(line, sizeof(line)) != NULL) {
+                               char *p, *q;
 
-
-FILE *tracefile;
-
-
-void
-trputc(int c)
-{
-       if (debug != 1)
-               return;
-       putc(c, tracefile);
-}
-
-void
-trace(const char *fmt, ...)
-{
-       va_list va;
-
-       if (debug != 1)
-               return;
-       va_start(va, fmt);
-       (void) vfprintf(tracefile, fmt, va);
-       va_end(va);
-}
-
-void
-tracev(const char *fmt, va_list va)
-{
-       if (debug != 1)
-               return;
-       (void) vfprintf(tracefile, fmt, va);
-}
-
-
-void
-trputs(const char *s)
-{
-       if (debug != 1)
-               return;
-       fputs(s, tracefile);
+                               p = line;
+                               for (q = eofmark + 1; *q && *p == *q; p++, q++);
+                               if (*p == '\n' && *q == '\0') {
+                                       c = PEOF;
+                                       plinno++;
+                                       needprompt = doprompt;
+                               } else {
+                                       pushstring(line, NULL);
+                               }
+                       }
+               }
+       }
+       goto checkend_return;
 }
 
+/*
+ * Parse a redirection operator.  The variable "out" points to a string
+ * specifying the fd to be redirected.  The variable "c" contains the
+ * first character of the redirection operator.
+ */
+parseredir: {
+       char fd = *out;
+       union node *np;
 
-static void
-trstring(char *s)
-{
-       char *p;
-       char c;
+       np = stalloc(sizeof(struct nfile));
+       if (c == '>') {
+               np->nfile.fd = 1;
+               c = pgetc();
+               if (c == '>')
+                       np->type = NAPPEND;
+               else if (c == '|')
+                       np->type = NCLOBBER;
+               else if (c == '&')
+                       np->type = NTOFD;
+               else {
+                       np->type = NTO;
+                       pungetc();
+               }
+       } else {        /* c == '<' */
+               np->nfile.fd = 0;
+               c = pgetc();
+               switch (c) {
+               case '<':
+                       if (sizeof(struct nfile) != sizeof(struct nhere)) {
+                               np = stalloc(sizeof(struct nhere));
+                               np->nfile.fd = 0;
+                       }
+                       np->type = NHERE;
+                       heredoc = stalloc(sizeof(struct heredoc));
+                       heredoc->here = np;
+                       c = pgetc();
+                       if (c == '-') {
+                               heredoc->striptabs = 1;
+                       } else {
+                               heredoc->striptabs = 0;
+                               pungetc();
+                       }
+                       break;
 
-       if (debug != 1)
-               return;
-       putc('"', tracefile);
-       for (p = s ; *p ; p++) {
-               switch (*p) {
-               case '\n':  c = 'n';  goto backslash;
-               case '\t':  c = 't';  goto backslash;
-               case '\r':  c = 'r';  goto backslash;
-               case '"':  c = '"';  goto backslash;
-               case '\\':  c = '\\';  goto backslash;
-               case CTLESC:  c = 'e';  goto backslash;
-               case CTLVAR:  c = 'v';  goto backslash;
-               case CTLVAR+CTLQUOTE:  c = 'V';  goto backslash;
-               case CTLBACKQ:  c = 'q';  goto backslash;
-               case CTLBACKQ+CTLQUOTE:  c = 'Q';  goto backslash;
-backslash:        putc('\\', tracefile);
-                       putc(c, tracefile);
+               case '&':
+                       np->type = NFROMFD;
+                       break;
+
+               case '>':
+                       np->type = NFROMTO;
                        break;
+
                default:
-                       if (*p >= ' ' && *p <= '~')
-                               putc(*p, tracefile);
-                       else {
-                               putc('\\', tracefile);
-                               putc(*p >> 6 & 03, tracefile);
-                               putc(*p >> 3 & 07, tracefile);
-                               putc(*p & 07, tracefile);
-                       }
+                       np->type = NFROM;
+                       pungetc();
                        break;
                }
        }
-       putc('"', tracefile);
-}
-
-
-void
-trargs(char **ap)
-{
-       if (debug != 1)
-               return;
-       while (*ap) {
-               trstring(*ap++);
-               if (*ap)
-                       putc(' ', tracefile);
-               else
-                       putc('\n', tracefile);
-       }
+       if (fd != '\0')
+               np->nfile.fd = fd - '0';
+       redirnode = np;
+       goto parseredir_return;
 }
 
+/*
+ * Parse a substitution.  At this point, we have read the dollar sign
+ * and nothing else.
+ */
 
-void
-opentrace(void)
-{
-       char s[100];
-#ifdef O_APPEND
+/* is_special(c) evaluates to 1 for c in "!#$*-0123456789?@"; 0 otherwise
+ * (assuming ascii char codes, as the original implementation did) */
+#define is_special(c) \
+       ((((unsigned int)c) - 33 < 32) \
+                       && ((0xc1ff920dUL >> (((unsigned int)c) - 33)) & 1))
+parsesub: {
+       int subtype;
+       int typeloc;
        int flags;
-#endif
+       char *p;
+       static const char types[] ALIGN1 = "}-+?=";
 
-       if (debug != 1) {
-               if (tracefile)
-                       fflush(tracefile);
-               /* leave open because libedit might be using it */
-               return;
-       }
-       scopy("./trace", s);
-       if (tracefile) {
-               if (!freopen(s, "a", tracefile)) {
-                       fprintf(stderr, "Can't re-open %s\n", s);
-                       debug = 0;
-                       return;
+       c = pgetc();
+       if (
+               c <= PEOA_OR_PEOF  ||
+               (c != '(' && c != '{' && !is_name(c) && !is_special(c))
+       ) {
+               USTPUTC('$', out);
+               pungetc();
+       } else if (c == '(') {  /* $(command) or $((arith)) */
+               if (pgetc() == '(') {
+#if ENABLE_ASH_MATH_SUPPORT
+                       PARSEARITH();
+#else
+                       raise_error_syntax("We unsupport $((arith))");
+#endif
+               } else {
+                       pungetc();
+                       PARSEBACKQNEW();
                }
        } else {
-               if ((tracefile = fopen(s, "a")) == NULL) {
-                       fprintf(stderr, "Can't open %s\n", s);
-                       debug = 0;
-                       return;
+               USTPUTC(CTLVAR, out);
+               typeloc = out - (char *)stackblock();
+               USTPUTC(VSNORMAL, out);
+               subtype = VSNORMAL;
+               if (c == '{') {
+                       c = pgetc();
+                       if (c == '#') {
+                               c = pgetc();
+                               if (c == '}')
+                                       c = '#';
+                               else
+                                       subtype = VSLENGTH;
+                       } else
+                               subtype = 0;
+               }
+               if (c > PEOA_OR_PEOF && is_name(c)) {
+                       do {
+                               STPUTC(c, out);
+                               c = pgetc();
+                       } while (c > PEOA_OR_PEOF && is_in_name(c));
+               } else if (isdigit(c)) {
+                       do {
+                               STPUTC(c, out);
+                               c = pgetc();
+                       } while (isdigit(c));
+               } else if (is_special(c)) {
+                       USTPUTC(c, out);
+                       c = pgetc();
+               } else
+ badsub:               raise_error_syntax("Bad substitution");
+
+               STPUTC('=', out);
+               flags = 0;
+               if (subtype == 0) {
+                       switch (c) {
+                       case ':':
+                               flags = VSNUL;
+                               c = pgetc();
+                               /*FALLTHROUGH*/
+                       default:
+                               p = strchr(types, c);
+                               if (p == NULL)
+                                       goto badsub;
+                               subtype = p - types + VSNORMAL;
+                               break;
+                       case '%':
+                       case '#':
+                               {
+                                       int cc = c;
+                                       subtype = c == '#' ? VSTRIMLEFT :
+                                                            VSTRIMRIGHT;
+                                       c = pgetc();
+                                       if (c == cc)
+                                               subtype++;
+                                       else
+                                               pungetc();
+                                       break;
+                               }
+                       }
+               } else {
+                       pungetc();
+               }
+               if (dblquote || arinest)
+                       flags |= VSQUOTE;
+               *((char *)stackblock() + typeloc) = subtype | flags;
+               if (subtype != VSNORMAL) {
+                       varnest++;
+                       if (dblquote || arinest) {
+                               dqvarnest++;
+                       }
                }
        }
-#ifdef O_APPEND
-       if ((flags = fcntl(fileno(tracefile), F_GETFL, 0)) >= 0)
-               fcntl(fileno(tracefile), F_SETFL, flags | O_APPEND);
-#endif
-       setlinebuf(tracefile);
-       fputs("\nTracing started.\n", tracefile);
+       goto parsesub_return;
 }
-#endif /* DEBUG */
-
-
-/*      trap.c       */
 
 /*
- * Sigmode records the current value of the signal handlers for the various
- * modes.  A value of zero means that the current handler is not known.
- * S_HARD_IGN indicates that the signal was ignored on entry to the shell,
+ * Called to parse command substitutions.  Newstyle is set if the command
+ * is enclosed inside $(...); nlpp is a pointer to the head of the linked
+ * list of commands (passed by reference), and savelen is the number of
+ * characters on the top of the stack which must be preserved.
  */
+parsebackq: {
+       struct nodelist **nlpp;
+       smallint savepbq;
+       union node *n;
+       char *volatile str;
+       struct jmploc jmploc;
+       struct jmploc *volatile savehandler;
+       size_t savelen;
+       smallint saveprompt = 0;
 
-#define S_DFL 1                 /* default signal handling (SIG_DFL) */
-#define S_CATCH 2               /* signal is caught */
-#define S_IGN 3                 /* signal is ignored (SIG_IGN) */
-#define S_HARD_IGN 4            /* signal is ignored permenantly */
-#define S_RESET 5               /* temporary - to reset a hard ignored sig */
+#ifdef __GNUC__
+       (void) &saveprompt;
+#endif
+       savepbq = parsebackquote;
+       if (setjmp(jmploc.loc)) {
+               free(str);
+               parsebackquote = 0;
+               exception_handler = savehandler;
+               longjmp(exception_handler->loc, 1);
+       }
+       INT_OFF;
+       str = NULL;
+       savelen = out - (char *)stackblock();
+       if (savelen > 0) {
+               str = ckmalloc(savelen);
+               memcpy(str, stackblock(), savelen);
+       }
+       savehandler = exception_handler;
+       exception_handler = &jmploc;
+       INT_ON;
+       if (oldstyle) {
+               /* We must read until the closing backquote, giving special
+                  treatment to some slashes, and then push the string and
+                  reread it as input, interpreting it normally.  */
+               char *pout;
+               int pc;
+               size_t psavelen;
+               char *pstr;
 
 
+               STARTSTACKSTR(pout);
+               for (;;) {
+                       if (needprompt) {
+                               setprompt(2);
+                       }
+                       pc = pgetc();
+                       switch (pc) {
+                       case '`':
+                               goto done;
 
-/*
- * The trap builtin.
- */
+                       case '\\':
+                               pc = pgetc();
+                               if (pc == '\n') {
+                                       plinno++;
+                                       if (doprompt)
+                                               setprompt(2);
+                                       /*
+                                        * If eating a newline, avoid putting
+                                        * the newline into the new character
+                                        * stream (via the STPUTC after the
+                                        * switch).
+                                        */
+                                       continue;
+                               }
+                               if (pc != '\\' && pc != '`' && pc != '$'
+                                && (!dblquote || pc != '"'))
+                                       STPUTC('\\', pout);
+                               if (pc > PEOA_OR_PEOF) {
+                                       break;
+                               }
+                               /* fall through */
 
-int
-trapcmd(int argc, char **argv)
-{
-       char *action;
-       char **ap;
-       int signo;
+                       case PEOF:
+#if ENABLE_ASH_ALIAS
+                       case PEOA:
+#endif
+                               startlinno = plinno;
+                               raise_error_syntax("EOF in backquote substitution");
 
-       nextopt(nullstr);
-       ap = argptr;
-       if (!*ap) {
-               for (signo = 0 ; signo < NSIG ; signo++) {
-                       if (trap[signo] != NULL) {
-                               const char *sn;
+                       case '\n':
+                               plinno++;
+                               needprompt = doprompt;
+                               break;
 
-                               sn = get_signame(signo);
-                               out1fmt("trap -- %s %s\n",
-                                       single_quote(trap[signo]), sn);
+                       default:
+                               break;
                        }
+                       STPUTC(pc, pout);
                }
-               return 0;
-       }
-       if (!ap[1])
-               action = NULL;
-       else
-               action = *ap++;
-       while (*ap) {
-               if ((signo = get_signum(*ap)) < 0)
-                       sh_error("%s: bad trap", *ap);
-               INTOFF;
-               if (action) {
-                       if (action[0] == '-' && action[1] == '\0')
-                               action = NULL;
-                       else
-                               action = savestr(action);
+ done:
+               STPUTC('\0', pout);
+               psavelen = pout - (char *)stackblock();
+               if (psavelen > 0) {
+                       pstr = grabstackstr(pout);
+                       setinputstring(pstr);
                }
-               if (trap[signo])
-                       ckfree(trap[signo]);
-               trap[signo] = action;
-               if (signo != 0)
-                       setsignal(signo);
-               INTON;
-               ap++;
        }
-       return 0;
-}
+       nlpp = &bqlist;
+       while (*nlpp)
+               nlpp = &(*nlpp)->next;
+       *nlpp = stalloc(sizeof(**nlpp));
+       (*nlpp)->next = NULL;
+       parsebackquote = oldstyle;
 
+       if (oldstyle) {
+               saveprompt = doprompt;
+               doprompt = 0;
+       }
 
-/*
- * Clear traps on a fork.
- */
+       n = list(2);
 
-void
-clear_traps(void)
-{
-       char **tp;
+       if (oldstyle)
+               doprompt = saveprompt;
+       else if (readtoken() != TRP)
+               raise_error_unexpected_syntax(TRP);
 
-       for (tp = trap ; tp < &trap[NSIG] ; tp++) {
-               if (*tp && **tp) {      /* trap not NULL or SIG_IGN */
-                       INTOFF;
-                       ckfree(*tp);
-                       *tp = NULL;
-                       if (tp != &trap[0])
-                               setsignal(tp - trap);
-                       INTON;
-               }
+       (*nlpp)->n = n;
+       if (oldstyle) {
+               /*
+                * Start reading from old file again, ignoring any pushed back
+                * tokens left from the backquote parsing
+                */
+               popfile();
+               tokpushback = 0;
+       }
+       while (stackblocksize() <= savelen)
+               growstackblock();
+       STARTSTACKSTR(out);
+       if (str) {
+               memcpy(out, str, savelen);
+               STADJUST(savelen, out);
+               INT_OFF;
+               free(str);
+               str = NULL;
+               INT_ON;
        }
+       parsebackquote = savepbq;
+       exception_handler = savehandler;
+       if (arinest || dblquote)
+               USTPUTC(CTLBACKQ | CTLQUOTE, out);
+       else
+               USTPUTC(CTLBACKQ, out);
+       if (oldstyle)
+               goto parsebackq_oldreturn;
+       goto parsebackq_newreturn;
 }
 
-
+#if ENABLE_ASH_MATH_SUPPORT
 /*
- * Set the signal handler for the specified signal.  The routine figures
- * out what it should be set to.
+ * Parse an arithmetic expansion (indicate start of one and set state)
  */
-
-void
-setsignal(int signo)
-{
-       int action;
-       char *t, tsig;
-       struct sigaction act;
-
-       if ((t = trap[signo]) == NULL)
-               action = S_DFL;
-       else if (*t != '\0')
-               action = S_CATCH;
-       else
-               action = S_IGN;
-       if (rootshell && action == S_DFL) {
-               switch (signo) {
-               case SIGINT:
-                       if (iflag || minusc || sflag == 0)
-                               action = S_CATCH;
-                       break;
-               case SIGQUIT:
-#if DEBUG
-                       if (debug)
-                               break;
-#endif
-                       /* FALLTHROUGH */
-               case SIGTERM:
-                       if (iflag)
-                               action = S_IGN;
-                       break;
-#if JOBS
-               case SIGTSTP:
-               case SIGTTOU:
-                       if (mflag)
-                               action = S_IGN;
-                       break;
-#endif
-               }
-       }
-
-       t = &sigmode[signo - 1];
-       tsig = *t;
-       if (tsig == 0) {
+parsearith: {
+       if (++arinest == 1) {
+               prevsyntax = syntax;
+               syntax = ARISYNTAX;
+               USTPUTC(CTLARI, out);
+               if (dblquote)
+                       USTPUTC('"', out);
+               else
+                       USTPUTC(' ', out);
+       } else {
                /*
-                * current setting unknown
+                * we collapse embedded arithmetic expansion to
+                * parenthesis, which should be equivalent
                 */
-               if (sigaction(signo, 0, &act) == -1) {
-                       /*
-                        * Pretend it worked; maybe we should give a warning
-                        * here, but other shells don't. We don't alter
-                        * sigmode, so that we retry every time.
-                        */
-                       return;
-               }
-               if (act.sa_handler == SIG_IGN) {
-                       if (mflag && (signo == SIGTSTP ||
-                            signo == SIGTTIN || signo == SIGTTOU)) {
-                               tsig = S_IGN;   /* don't hard ignore these */
-                       } else
-                               tsig = S_HARD_IGN;
-               } else {
-                       tsig = S_RESET; /* force to be set */
-               }
-       }
-       if (tsig == S_HARD_IGN || tsig == action)
-               return;
-       switch (action) {
-       case S_CATCH:
-               act.sa_handler = onsig;
-               break;
-       case S_IGN:
-               act.sa_handler = SIG_IGN;
-               break;
-       default:
-               act.sa_handler = SIG_DFL;
+               USTPUTC('(', out);
        }
-       *t = action;
-       act.sa_flags = 0;
-       sigfillset(&act.sa_mask);
-       sigaction(signo, &act, 0);
+       goto parsearith_return;
 }
+#endif
+
+} /* end of readtoken */
 
 /*
- * Ignore a signal.
+ * Read the next input token.
+ * If the token is a word, we set backquotelist to the list of cmds in
+ *      backquotes.  We set quoteflag to true if any part of the word was
+ *      quoted.
+ * If the token is TREDIR, then we set redirnode to a structure containing
+ *      the redirection.
+ * In all cases, the variable startlinno is set to the number of the line
+ *      on which the token starts.
+ *
+ * [Change comment:  here documents and internal procedures]
+ * [Readtoken shouldn't have any arguments.  Perhaps we should make the
+ *  word parsing code into a separate routine.  In this case, readtoken
+ *  doesn't need to have any internal procedures, but parseword does.
+ *  We could also make parseoperator in essence the main routine, and
+ *  have parseword (readtoken1?) handle both words and redirection.]
  */
+#define NEW_xxreadtoken
+#ifdef NEW_xxreadtoken
+/* singles must be first! */
+static const char xxreadtoken_chars[7] ALIGN1 = {
+       '\n', '(', ')', '&', '|', ';', 0
+};
 
-void
-ignoresig(int signo)
+static const char xxreadtoken_tokens[] ALIGN1 = {
+       TNL, TLP, TRP,          /* only single occurrence allowed */
+       TBACKGND, TPIPE, TSEMI, /* if single occurrence */
+       TEOF,                   /* corresponds to trailing nul */
+       TAND, TOR, TENDCASE     /* if double occurrence */
+};
+
+#define xxreadtoken_doubles \
+       (sizeof(xxreadtoken_tokens) - sizeof(xxreadtoken_chars))
+#define xxreadtoken_singles \
+       (sizeof(xxreadtoken_chars) - xxreadtoken_doubles - 1)
+
+static int
+xxreadtoken(void)
 {
-       if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) {
-               signal(signo, SIG_IGN);
+       int c;
+
+       if (tokpushback) {
+               tokpushback = 0;
+               return lasttoken;
        }
-       sigmode[signo - 1] = S_HARD_IGN;
-}
+       if (needprompt) {
+               setprompt(2);
+       }
+       startlinno = plinno;
+       for (;;) {                      /* until token or start of word found */
+               c = pgetc_macro();
 
+               if ((c != ' ') && (c != '\t')
+#if ENABLE_ASH_ALIAS
+                && (c != PEOA)
+#endif
+               ) {
+                       if (c == '#') {
+                               while ((c = pgetc()) != '\n' && c != PEOF);
+                               pungetc();
+                       } else if (c == '\\') {
+                               if (pgetc() != '\n') {
+                                       pungetc();
+                                       goto READTOKEN1;
+                               }
+                               startlinno = ++plinno;
+                               if (doprompt)
+                                       setprompt(2);
+                       } else {
+                               const char *p
+                                       = xxreadtoken_chars + sizeof(xxreadtoken_chars) - 1;
 
-/*
- * Signal handler.
- */
+                               if (c != PEOF) {
+                                       if (c == '\n') {
+                                               plinno++;
+                                               needprompt = doprompt;
+                                       }
 
-void
-onsig(int signo)
-{
-       gotsig[signo - 1] = 1;
-       pendingsigs = signo;
+                                       p = strchr(xxreadtoken_chars, c);
+                                       if (p == NULL) {
+ READTOKEN1:
+                                               return readtoken1(c, BASESYNTAX, (char *) NULL, 0);
+                                       }
 
-       if (exsig || (signo == SIGINT && !trap[SIGINT])) {
-               if (!suppressint)
-                       onint();
-               intpending = 1;
-       }
+                                       if (p - xxreadtoken_chars >= xxreadtoken_singles) {
+                                               if (pgetc() == *p) {    /* double occurrence? */
+                                                       p += xxreadtoken_doubles + 1;
+                                               } else {
+                                                       pungetc();
+                                               }
+                                       }
+                               }
+                               return lasttoken = xxreadtoken_tokens[p - xxreadtoken_chars];
+                       }
+               }
+       } /* for */
 }
-
-
-/*
- * Called to execute a trap.  Perhaps we should avoid entering new trap
- * handlers while we are executing a trap handler.
- */
-
-int
-dotrap(void)
+#else
+#define RETURN(token)   return lasttoken = token
+static int
+xxreadtoken(void)
 {
-       char *p;
-       char *q;
-       int i;
-       int savestatus;
-       int skip = 0;
-
-       savestatus = exitstatus;
-       pendingsigs = 0;
-       xbarrier();
+       int c;
 
-       for (i = 0, q = gotsig; i < NSIG - 1; i++, q++) {
-               if (!*q)
+       if (tokpushback) {
+               tokpushback = 0;
+               return lasttoken;
+       }
+       if (needprompt) {
+               setprompt(2);
+       }
+       startlinno = plinno;
+       for (;;) {      /* until token or start of word found */
+               c = pgetc_macro();
+               switch (c) {
+               case ' ': case '\t':
+#if ENABLE_ASH_ALIAS
+               case PEOA:
+#endif
                        continue;
-               *q = 0;
-
-               p = trap[i + 1];
-               if (!p)
+               case '#':
+                       while ((c = pgetc()) != '\n' && c != PEOF);
+                       pungetc();
                        continue;
-               skip = evalstring(p, SKIPEVAL);
-               exitstatus = savestatus;
-               if (skip)
-                       break;
+               case '\\':
+                       if (pgetc() == '\n') {
+                               startlinno = ++plinno;
+                               if (doprompt)
+                                       setprompt(2);
+                               continue;
+                       }
+                       pungetc();
+                       goto breakloop;
+               case '\n':
+                       plinno++;
+                       needprompt = doprompt;
+                       RETURN(TNL);
+               case PEOF:
+                       RETURN(TEOF);
+               case '&':
+                       if (pgetc() == '&')
+                               RETURN(TAND);
+                       pungetc();
+                       RETURN(TBACKGND);
+               case '|':
+                       if (pgetc() == '|')
+                               RETURN(TOR);
+                       pungetc();
+                       RETURN(TPIPE);
+               case ';':
+                       if (pgetc() == ';')
+                               RETURN(TENDCASE);
+                       pungetc();
+                       RETURN(TSEMI);
+               case '(':
+                       RETURN(TLP);
+               case ')':
+                       RETURN(TRP);
+               default:
+                       goto breakloop;
+               }
        }
-
-       return skip;
+ breakloop:
+       return readtoken1(c, BASESYNTAX, (char *)NULL, 0);
+#undef RETURN
 }
+#endif /* NEW_xxreadtoken */
 
-
-/*
- * Controls whether the shell is interactive or not.
- */
-
-void
-setinteractive(int on)
+static int
+readtoken(void)
 {
-       static int is_interactive;
+       int t;
+#if DEBUG
+       smallint alreadyseen = tokpushback;
+#endif
 
-       if (++on == is_interactive)
-               return;
-       is_interactive = on;
-       setsignal(SIGINT);
-       setsignal(SIGQUIT);
-       setsignal(SIGTERM);
-#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
-               if(is_interactive > 1) {
-                       /* Looks like they want an interactive shell */
-                       static int do_banner;
-
-                               if(!do_banner) {
-                                       out1fmt(
-                       "\n\n%s Built-in shell (ash)\n"
-                       "Enter 'help' for a list of built-in commands.\n\n",
-                                       BB_BANNER);
-                                       do_banner++;
-                               }
-               }
+#if ENABLE_ASH_ALIAS
+ top:
 #endif
-}
 
+       t = xxreadtoken();
 
-#ifndef CONFIG_FEATURE_SH_EXTRA_QUIET
-/*** List the available builtins ***/
+       /*
+        * eat newlines
+        */
+       if (checkkwd & CHKNL) {
+               while (t == TNL) {
+                       parseheredoc();
+                       t = xxreadtoken();
+               }
+       }
 
-static int helpcmd(int argc, char **argv)
-{
-       int col, i;
+       if (t != TWORD || quoteflag) {
+               goto out;
+       }
 
-       out1fmt("\nBuilt-in commands:\n-------------------\n");
-       for (col = 0, i = 0; i < NUMBUILTINS; i++) {
-               col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '),
-                                         builtincmd[i].name + 1);
-               if (col > 60) {
-                       out1fmt("\n");
-                       col = 0;
+       /*
+        * check for keywords
+        */
+       if (checkkwd & CHKKWD) {
+               const char *const *pp;
+
+               pp = findkwd(wordtext);
+               if (pp) {
+                       lasttoken = t = pp - tokname_array;
+                       TRACE(("keyword %s recognized\n", tokname(t)));
+                       goto out;
                }
        }
-#ifdef CONFIG_FEATURE_SH_STANDALONE_SHELL
-       {
-               extern const struct BB_applet applets[];
-               extern const size_t NUM_APPLETS;
-
-               for (i = 0; i < NUM_APPLETS; i++) {
 
-                       col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), applets[i].name);
-                       if (col > 60) {
-                               out1fmt("\n");
-                               col = 0;
+       if (checkkwd & CHKALIAS) {
+#if ENABLE_ASH_ALIAS
+               struct alias *ap;
+               ap = lookupalias(wordtext, 1);
+               if (ap != NULL) {
+                       if (*ap->val) {
+                               pushstring(ap->val, ap);
                        }
+                       goto top;
                }
+#endif
        }
+ out:
+       checkkwd = 0;
+#if DEBUG
+       if (!alreadyseen)
+               TRACE(("token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
+       else
+               TRACE(("reread token %s %s\n", tokname(t), t == TWORD ? wordtext : ""));
 #endif
-       out1fmt("\n\n");
-       return EXIT_SUCCESS;
+       return t;
+}
+
+static char
+peektoken(void)
+{
+       int t;
+
+       t = readtoken();
+       tokpushback = 1;
+       return tokname_array[t][0];
 }
-#endif /* CONFIG_FEATURE_SH_EXTRA_QUIET */
 
 /*
- * Called to exit the shell.
+ * Read and parse a command.  Returns NEOF on end of file.  (NULL is a
+ * valid parse tree indicating a blank line.)
  */
+static union node *
+parsecmd(int interact)
+{
+       int t;
 
-void
-exitshell(void)
+       tokpushback = 0;
+       doprompt = interact;
+       if (doprompt)
+               setprompt(doprompt);
+       needprompt = 0;
+       t = readtoken();
+       if (t == TEOF)
+               return NEOF;
+       if (t == TNL)
+               return NULL;
+       tokpushback = 1;
+       return list(1);
+}
+
+/*
+ * Input any here documents.
+ */
+static void
+parseheredoc(void)
 {
-       struct jmploc loc;
-       char *p;
-       int status;
+       struct heredoc *here;
+       union node *n;
 
-       status = exitstatus;
-       TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
-       if (setjmp(loc.loc)) {
-               if (exception == EXEXIT)
-                       _exit(exitstatus);
-               goto out;
-       }
-       handler = &loc;
-       if ((p = trap[0])) {
-               trap[0] = NULL;
-               evalstring(p, 0);
-       }
-       flushall();
-       setjobctl(0);
-#ifdef CONFIG_FEATURE_COMMAND_SAVEHISTORY
-       if (iflag && rootshell) {
-               const char *hp = lookupvar("HISTFILE");
+       here = heredoclist;
+       heredoclist = 0;
 
-               if(hp != NULL )
-                       save_history ( hp );
-       }
-#endif
-out:
-       _exit(status);
-       /* NOTREACHED */
+       while (here) {
+               if (needprompt) {
+                       setprompt(2);
+               }
+               readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX,
+                               here->eofmark, here->striptabs);
+               n = stalloc(sizeof(struct narg));
+               n->narg.type = NARG;
+               n->narg.next = NULL;
+               n->narg.text = wordtext;
+               n->narg.backquote = backquotelist;
+               here->here->nhere.doc = n;
+               here = here->next;
+       }
 }
 
-/*      var.c     */
-
-static struct var *vartab[VTABSIZE];
-
-static int vpcmp(const void *, const void *);
-static struct var **findvar(struct var **, const char *);
 
 /*
- * Initialize the variable symbol tables and import the environment
+ * called by editline -- any expansions to the prompt should be added here.
  */
+#if ENABLE_ASH_EXPAND_PRMT
+static const char *
+expandstr(const char *ps)
+{
+       union node n;
+
+       /* XXX Fix (char *) cast. */
+       setinputstring((char *)ps);
+       readtoken1(pgetc(), PSSYNTAX, nullstr, 0);
+       popfile();
+
+       n.narg.type = NARG;
+       n.narg.next = NULL;
+       n.narg.text = wordtext;
+       n.narg.backquote = backquotelist;
 
+       expandarg(&n, NULL, 0);
+       return stackblock();
+}
+#endif
 
-#ifdef CONFIG_ASH_GETOPTS
 /*
- * Safe version of setvar, returns 1 on success 0 on failure.
+ * Execute a command or commands contained in a string.
  */
-
-int
-setvarsafe(const char *name, const char *val, int flags)
+static int
+evalstring(char *s, int mask)
 {
-       int err;
-       volatile int saveint;
-       struct jmploc *volatile savehandler = handler;
-       struct jmploc jmploc;
+       union node *n;
+       struct stackmark smark;
+       int skip;
 
-       SAVEINT(saveint);
-       if (setjmp(jmploc.loc))
-               err = 1;
-       else {
-               handler = &jmploc;
-               setvar(name, val, flags);
-               err = 0;
+       setinputstring(s);
+       setstackmark(&smark);
+
+       skip = 0;
+       while ((n = parsecmd(0)) != NEOF) {
+               evaltree(n, 0);
+               popstackmark(&smark);
+               skip = evalskip;
+               if (skip)
+                       break;
        }
-       handler = savehandler;
-       RESTOREINT(saveint);
-       return err;
+       popfile();
+
+       skip &= mask;
+       evalskip = skip;
+       return skip;
 }
-#endif
 
 /*
- * Set the value of a variable.  The flags argument is ored with the
- * flags of the variable.  If val is NULL, the variable is unset.
+ * The eval command.
  */
-
-static void
-setvar(const char *name, const char *val, int flags)
+static int
+evalcmd(int argc, char **argv)
 {
-       char *p, *q;
-       size_t namelen;
-       char *nameeq;
-       size_t vallen;
+       char *p;
+       char *concat;
+       char **ap;
+
+       if (argc > 1) {
+               p = argv[1];
+               if (argc > 2) {
+                       STARTSTACKSTR(concat);
+                       ap = argv + 2;
+                       for (;;) {
+                               concat = stack_putstr(p, concat);
+                               p = *ap++;
+                               if (p == NULL)
+                                       break;
+                               STPUTC(' ', concat);
+                       }
+                       STPUTC('\0', concat);
+                       p = grabstackstr(concat);
+               }
+               evalstring(p, ~SKIPEVAL);
 
-       q = endofname(name);
-       p = strchrnul(q, '=');
-       namelen = p - name;
-       if (!namelen || p != q)
-               sh_error("%.*s: bad variable name", namelen, name);
-       vallen = 0;
-       if (val == NULL) {
-               flags |= VUNSET;
-       } else {
-               vallen = strlen(val);
-       }
-       INTOFF;
-       p = mempcpy(nameeq = ckmalloc(namelen + vallen + 2), name, namelen);
-       if (val) {
-               *p++ = '=';
-               p = mempcpy(p, val, vallen);
        }
-       *p = '\0';
-       setvareq(nameeq, flags | VNOSAVE);
-       INTON;
+       return exitstatus;
 }
 
-
 /*
- * Same as setvar except that the variable and value are passed in
- * the first argument as name=value.  Since the first argument will
- * be actually stored in the table, it should not be a string that
- * will go away.
- * Called with interrupts off.
+ * Read and execute commands.  "Top" is nonzero for the top level command
+ * loop; it turns on prompting if the shell is interactive.
  */
-
-void
-setvareq(char *s, int flags)
+static int
+cmdloop(int top)
 {
-       struct var *vp, **vpp;
+       union node *n;
+       struct stackmark smark;
+       int inter;
+       int numeof = 0;
 
-       vpp = hashvar(s);
-       flags |= (VEXPORT & (((unsigned) (1 - aflag)) - 1));
-       vp = *findvar(vpp, s);
-       if (vp) {
-               if ((vp->flags & (VREADONLY|VDYNAMIC)) == VREADONLY) {
-                       const char *n;
+       TRACE(("cmdloop(%d) called\n", top));
+       for (;;) {
+               int skip;
 
-                       if (flags & VNOSAVE)
-                               free(s);
-                       n = vp->text;
-                       sh_error("%.*s: is read only", strchrnul(n, '=') - n, n);
+               setstackmark(&smark);
+#if JOBS
+               if (jobctl)
+                       showjobs(stderr, SHOW_CHANGED);
+#endif
+               inter = 0;
+               if (iflag && top) {
+                       inter++;
+#if ENABLE_ASH_MAIL
+                       chkmail();
+#endif
+               }
+               n = parsecmd(inter);
+               /* showtree(n); DEBUG */
+               if (n == NEOF) {
+                       if (!top || numeof >= 50)
+                               break;
+                       if (!stoppedjobs()) {
+                               if (!Iflag)
+                                       break;
+                               out2str("\nUse \"exit\" to leave shell.\n");
+                       }
+                       numeof++;
+               } else if (nflag == 0) {
+                       /* job_warning can only be 2,1,0. Here 2->1, 1/0->0 */
+                       job_warning >>= 1;
+                       numeof = 0;
+                       evaltree(n, 0);
                }
+               popstackmark(&smark);
+               skip = evalskip;
 
-               if (flags & VNOSET)
-                       return;
+               if (skip) {
+                       evalskip = 0;
+                       return skip & SKIPEVAL;
+               }
+       }
+       return 0;
+}
 
-               if (vp->func && (flags & VNOFUNC) == 0)
-                       (*vp->func)(strchrnul(s, '=') + 1);
+/*
+ * Take commands from a file.  To be compatible we should do a path
+ * search for the file, which is necessary to find sub-commands.
+ */
+static char *
+find_dot_file(char *name)
+{
+       char *fullname;
+       const char *path = pathval();
+       struct stat statb;
 
-               if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
-                       ckfree(vp->text);
+       /* don't try this for absolute or relative paths */
+       if (strchr(name, '/'))
+               return name;
 
-               flags |= vp->flags & ~(VTEXTFIXED|VSTACK|VNOSAVE|VUNSET);
-       } else {
-               if (flags & VNOSET)
-                       return;
-               /* not found */
-               vp = ckmalloc(sizeof (*vp));
-               vp->next = *vpp;
-               vp->func = NULL;
-               *vpp = vp;
+       while ((fullname = padvance(&path, name)) != NULL) {
+               if ((stat(fullname, &statb) == 0) && S_ISREG(statb.st_mode)) {
+                       /*
+                        * Don't bother freeing here, since it will
+                        * be freed by the caller.
+                        */
+                       return fullname;
+               }
+               stunalloc(fullname);
        }
-       if (!(flags & (VTEXTFIXED|VSTACK|VNOSAVE)))
-               s = savestr(s);
-       vp->text = s;
-       vp->flags = flags;
+
+       /* not found in the PATH */
+       ash_msg_and_raise_error("%s: not found", name);
+       /* NOTREACHED */
 }
 
+static int
+dotcmd(int argc, char **argv)
+{
+       struct strlist *sp;
+       volatile struct shparam saveparam;
+       int status = 0;
 
-/*
- * Process a linked list of variable assignments.
- */
+       for (sp = cmdenviron; sp; sp = sp->next)
+               setvareq(ckstrdup(sp->text), VSTRFIXED | VTEXTFIXED);
 
-static void
-listsetvar(struct strlist *list_set_var, int flags)
-{
-       struct strlist *lp = list_set_var;
+       if (argc >= 2) {        /* That's what SVR2 does */
+               char *fullname;
 
-       if (!lp)
-               return;
-       INTOFF;
-       do {
-               setvareq(lp->text, flags);
-       } while ((lp = lp->next));
-       INTON;
-}
+               fullname = find_dot_file(argv[1]);
 
+               if (argc > 2) {
+                       saveparam = shellparam;
+                       shellparam.malloc = 0;
+                       shellparam.nparam = argc - 2;
+                       shellparam.p = argv + 2;
+               };
 
-/*
- * Find the value of a variable.  Returns NULL if not set.
- */
+               setinputfile(fullname, INPUT_PUSH_FILE);
+               commandname = fullname;
+               cmdloop(0);
+               popfile();
 
-static char *
-lookupvar(const char *name)
+               if (argc > 2) {
+                       freeparam(&shellparam);
+                       shellparam = saveparam;
+               };
+               status = exitstatus;
+       }
+       return status;
+}
+
+static int
+exitcmd(int argc, char **argv)
 {
-       struct var *v;
+       if (stoppedjobs())
+               return 0;
+       if (argc > 1)
+               exitstatus = number(argv[1]);
+       raise_exception(EXEXIT);
+       /* NOTREACHED */
+}
 
-       if ((v = *findvar(hashvar(name), name))) {
-#ifdef DYNAMIC_VAR
-       /*
-        * Dynamic variables are implemented roughly the same way they are
-        * in bash. Namely, they're "special" so long as they aren't unset.
-        * As soon as they're unset, they're no longer dynamic, and dynamic
-        * lookup will no longer happen at that point. -- PFM.
-        */
-               if((v->flags & VDYNAMIC))
-                       (*v->func)(NULL);
+#if ENABLE_ASH_BUILTIN_ECHO
+static int
+echocmd(int argc, char **argv)
+{
+       return bb_echo(argv);
+}
 #endif
-               if(!(v->flags & VUNSET))
-                       return strchrnul(v->text, '=') + 1;
-       }
 
-       return NULL;
+#if ENABLE_ASH_BUILTIN_TEST
+static int
+testcmd(int argc, char **argv)
+{
+       return test_main(argc, argv);
 }
-
+#endif
 
 /*
- * Search the environment of a builtin command.
+ * Read a file containing shell functions.
  */
-
-static char *
-bltinlookup(const char *name)
+static void
+readcmdfile(char *name)
 {
-       struct strlist *sp;
-
-       for (sp = cmdenviron ; sp ; sp = sp->next) {
-               if (varequal(sp->text, name))
-                       return strchrnul(sp->text, '=') + 1;
-       }
-       return lookupvar(name);
+       setinputfile(name, INPUT_PUSH_FILE);
+       cmdloop(0);
+       popfile();
 }
 
 
+/* ============ find_command inplementation */
+
 /*
- * Generate a list of variables satisfying the given conditions.
+ * Resolve a command name.  If you change this routine, you may have to
+ * change the shellexec routine as well.
  */
-
-static char **
-listvars(int on, int off, char ***end)
+static void
+find_command(char *name, struct cmdentry *entry, int act, const char *path)
 {
-       struct var **vpp;
-       struct var *vp;
-       char **ep;
-       int mask;
+       struct tblentry *cmdp;
+       int idx;
+       int prev;
+       char *fullname;
+       struct stat statb;
+       int e;
+       int updatetbl;
+       struct builtincmd *bcmd;
 
-       STARTSTACKSTR(ep);
-       vpp = vartab;
-       mask = on | off;
-       do {
-               for (vp = *vpp ; vp ; vp = vp->next)
-                       if ((vp->flags & mask) == on) {
-                               if (ep == stackstrend())
-                                       ep = growstackstr();
-                               *ep++ = (char *) vp->text;
+       /* If name contains a slash, don't use PATH or hash table */
+       if (strchr(name, '/') != NULL) {
+               entry->u.index = -1;
+               if (act & DO_ABS) {
+                       while (stat(name, &statb) < 0) {
+#ifdef SYSV
+                               if (errno == EINTR)
+                                       continue;
+#endif
+                               entry->cmdtype = CMDUNKNOWN;
+                               return;
                        }
-       } while (++vpp < vartab + VTABSIZE);
-       if (ep == stackstrend())
-               ep = growstackstr();
-       if (end)
-               *end = ep;
-       *ep++ = NULL;
-       return grabstackstr(ep);
-}
+               }
+               entry->cmdtype = CMDNORMAL;
+               return;
+       }
 
+/* #if ENABLE_FEATURE_SH_STANDALONE... moved after builtin check */
 
-/*
- * POSIX requires that 'set' (but not export or readonly) output the
- * variables in lexicographic order - by the locale's collating order (sigh).
- * Maybe we could keep them in an ordered balanced binary tree
- * instead of hashed lists.
- * For now just roll 'em through qsort for printing...
- */
+       updatetbl = (path == pathval());
+       if (!updatetbl) {
+               act |= DO_ALTPATH;
+               if (strstr(path, "%builtin") != NULL)
+                       act |= DO_ALTBLTIN;
+       }
 
-static int
-showvars(const char *sep_prefix, int on, int off)
-{
-       const char *sep;
-       char **ep, **epend;
+       /* If name is in the table, check answer will be ok */
+       cmdp = cmdlookup(name, 0);
+       if (cmdp != NULL) {
+               int bit;
 
-       ep = listvars(on, off, &epend);
-       qsort(ep, epend - ep, sizeof(char *), vpcmp);
+               switch (cmdp->cmdtype) {
+               default:
+#if DEBUG
+                       abort();
+#endif
+               case CMDNORMAL:
+                       bit = DO_ALTPATH;
+                       break;
+               case CMDFUNCTION:
+                       bit = DO_NOFUNC;
+                       break;
+               case CMDBUILTIN:
+                       bit = DO_ALTBLTIN;
+                       break;
+               }
+               if (act & bit) {
+                       updatetbl = 0;
+                       cmdp = NULL;
+               } else if (cmdp->rehash == 0)
+                       /* if not invalidated by cd, we're done */
+                       goto success;
+       }
 
-       sep = *sep_prefix ? spcstr : sep_prefix;
+       /* If %builtin not in path, check for builtin next */
+       bcmd = find_builtin(name);
+       if (bcmd) {
+               if (IS_BUILTIN_REGULAR(bcmd))
+                       goto builtin_success;
+               if (act & DO_ALTPATH) {
+                       if (!(act & DO_ALTBLTIN))
+                               goto builtin_success;
+               } else if (builtinloc <= 0) {
+                       goto builtin_success;
+               }
+       }
 
-       for (; ep < epend; ep++) {
-               const char *p;
-               const char *q;
+#if ENABLE_FEATURE_SH_STANDALONE
+       if (find_applet_by_name(name)) {
+               entry->cmdtype = CMDNORMAL;
+               entry->u.index = -1;
+               return;
+       }
+#endif
 
-               p = strchrnul(*ep, '=');
-               q = nullstr;
-               if (*p)
-                       q = single_quote(++p);
+       /* We have to search path. */
+       prev = -1;              /* where to start */
+       if (cmdp && cmdp->rehash) {     /* doing a rehash */
+               if (cmdp->cmdtype == CMDBUILTIN)
+                       prev = builtinloc;
+               else
+                       prev = cmdp->param.index;
+       }
 
-               out1fmt("%s%s%.*s%s\n", sep_prefix, sep, (int)(p - *ep), *ep, q);
+       e = ENOENT;
+       idx = -1;
+ loop:
+       while ((fullname = padvance(&path, name)) != NULL) {
+               stunalloc(fullname);
+               /* NB: code below will still use fullname
+                * despite it being "unallocated" */
+               idx++;
+               if (pathopt) {
+                       if (prefix(pathopt, "builtin")) {
+                               if (bcmd)
+                                       goto builtin_success;
+                               continue;
+                       } else if (!(act & DO_NOFUNC)
+                        && prefix(pathopt, "func")) {
+                               /* handled below */
+                       } else {
+                               /* ignore unimplemented options */
+                               continue;
+                       }
+               }
+               /* if rehash, don't redo absolute path names */
+               if (fullname[0] == '/' && idx <= prev) {
+                       if (idx < prev)
+                               continue;
+                       TRACE(("searchexec \"%s\": no change\n", name));
+                       goto success;
+               }
+               while (stat(fullname, &statb) < 0) {
+#ifdef SYSV
+                       if (errno == EINTR)
+                               continue;
+#endif
+                       if (errno != ENOENT && errno != ENOTDIR)
+                               e = errno;
+                       goto loop;
+               }
+               e = EACCES;     /* if we fail, this will be the error */
+               if (!S_ISREG(statb.st_mode))
+                       continue;
+               if (pathopt) {          /* this is a %func directory */
+                       stalloc(strlen(fullname) + 1);
+                       /* NB: stalloc will return space pointed by fullname
+                        * (because we don't have any intervening allocations
+                        * between stunalloc above and this stalloc) */
+                       readcmdfile(fullname);
+                       cmdp = cmdlookup(name, 0);
+                       if (cmdp == NULL || cmdp->cmdtype != CMDFUNCTION)
+                               ash_msg_and_raise_error("%s not defined in %s", name, fullname);
+                       stunalloc(fullname);
+                       goto success;
+               }
+               TRACE(("searchexec \"%s\" returns \"%s\"\n", name, fullname));
+               if (!updatetbl) {
+                       entry->cmdtype = CMDNORMAL;
+                       entry->u.index = idx;
+                       return;
+               }
+               INT_OFF;
+               cmdp = cmdlookup(name, 1);
+               cmdp->cmdtype = CMDNORMAL;
+               cmdp->param.index = idx;
+               INT_ON;
+               goto success;
        }
 
-       return 0;
+       /* We failed.  If there was an entry for this command, delete it */
+       if (cmdp && updatetbl)
+               delete_cmd_entry();
+       if (act & DO_ERR)
+               ash_msg("%s: %s", name, errmsg(e, "not found"));
+       entry->cmdtype = CMDUNKNOWN;
+       return;
+
+ builtin_success:
+       if (!updatetbl) {
+               entry->cmdtype = CMDBUILTIN;
+               entry->u.cmd = bcmd;
+               return;
+       }
+       INT_OFF;
+       cmdp = cmdlookup(name, 1);
+       cmdp->cmdtype = CMDBUILTIN;
+       cmdp->param.cmd = bcmd;
+       INT_ON;
+ success:
+       cmdp->rehash = 0;
+       entry->cmdtype = cmdp->cmdtype;
+       entry->u = cmdp->param;
 }
 
 
+/* ============ trap.c */
 
 /*
- * The export and readonly commands.
+ * The trap builtin.
  */
-
 static int
-exportcmd(int argc, char **argv)
+trapcmd(int argc, char **argv)
 {
-       struct var *vp;
-       char *name;
-       const char *p;
-       char **aptr;
-       int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
-       int notp;
+       char *action;
+       char **ap;
+       int signo;
 
-       notp = nextopt("p") - 'p';
-       if (notp && ((name = *(aptr = argptr)))) {
-               do {
-                       if ((p = strchr(name, '=')) != NULL) {
-                               p++;
-                       } else {
-                               if ((vp = *findvar(hashvar(name), name))) {
-                                       vp->flags |= flag;
-                                       continue;
-                               }
+       nextopt(nullstr);
+       ap = argptr;
+       if (!*ap) {
+               for (signo = 0; signo < NSIG; signo++) {
+                       if (trap[signo] != NULL) {
+                               const char *sn;
+
+                               sn = get_signame(signo);
+                               out1fmt("trap -- %s %s\n",
+                                       single_quote(trap[signo]), sn);
                        }
-                       setvar(name, p, flag);
-               } while ((name = *++aptr) != NULL);
-       } else {
-               showvars(argv[0], flag, 0);
+               }
+               return 0;
+       }
+       if (!ap[1])
+               action = NULL;
+       else
+               action = *ap++;
+       while (*ap) {
+               signo = get_signum(*ap);
+               if (signo < 0)
+                       ash_msg_and_raise_error("%s: bad trap", *ap);
+               INT_OFF;
+               if (action) {
+                       if (LONE_DASH(action))
+                               action = NULL;
+                       else
+                               action = ckstrdup(action);
+               }
+               free(trap[signo]);
+               trap[signo] = action;
+               if (signo != 0)
+                       setsignal(signo);
+               INT_ON;
+               ap++;
        }
        return 0;
 }
 
 
+/* ============ Builtins */
+
+#if !ENABLE_FEATURE_SH_EXTRA_QUIET
 /*
- * Make a variable a local variable.  When a variable is made local, it's
- * value and flags are saved in a localvar structure.  The saved values
- * will be restored when the shell function returns.  We handle the name
- * "-" as a special case.
+ * Lists available builtins
  */
-
-static void mklocal(char *name)
+static int
+helpcmd(int argc, char **argv)
 {
-       struct localvar *lvp;
-       struct var **vpp;
-       struct var *vp;
-
-       INTOFF;
-       lvp = ckmalloc(sizeof (struct localvar));
-       if (name[0] == '-' && name[1] == '\0') {
-               char *p;
-               p = ckmalloc(sizeof(optlist));
-               lvp->text = memcpy(p, optlist, sizeof(optlist));
-               vp = NULL;
-       } else {
-               char *eq;
+       int col, i;
 
-               vpp = hashvar(name);
-               vp = *findvar(vpp, name);
-               eq = strchr(name, '=');
-               if (vp == NULL) {
-                       if (eq)
-                               setvareq(name, VSTRFIXED);
-                       else
-                               setvar(name, NULL, VSTRFIXED);
-                       vp = *vpp;      /* the new variable */
-                       lvp->flags = VUNSET;
-               } else {
-                       lvp->text = vp->text;
-                       lvp->flags = vp->flags;
-                       vp->flags |= VSTRFIXED|VTEXTFIXED;
-                       if (eq)
-                               setvareq(name, 0);
+       out1fmt("\nBuilt-in commands:\n-------------------\n");
+       for (col = 0, i = 0; i < ARRAY_SIZE(builtintab); i++) {
+               col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '),
+                                       builtintab[i].name + 1);
+               if (col > 60) {
+                       out1fmt("\n");
+                       col = 0;
                }
        }
-       lvp->vp = vp;
-       lvp->next = localvars;
-       localvars = lvp;
-       INTON;
+#if ENABLE_FEATURE_SH_STANDALONE
+       for (i = 0; i < NUM_APPLETS; i++) {
+               col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '), applets[i].name);
+               if (col > 60) {
+                       out1fmt("\n");
+                       col = 0;
+               }
+       }
+#endif
+       out1fmt("\n\n");
+       return EXIT_SUCCESS;
 }
+#endif /* FEATURE_SH_EXTRA_QUIET */
 
 /*
- * The "local" command.
+ * The export and readonly commands.
  */
-
 static int
-localcmd(int argc, char **argv)
+exportcmd(int argc, char **argv)
 {
+       struct var *vp;
        char *name;
+       const char *p;
+       char **aptr;
+       int flag = argv[0][0] == 'r'? VREADONLY : VEXPORT;
 
-       argv = argptr;
-       while ((name = *argv++) != NULL) {
-               mklocal(name);
+       if (nextopt("p") != 'p') {
+               aptr = argptr;
+               name = *aptr;
+               if (name) {
+                       do {
+                               p = strchr(name, '=');
+                               if (p != NULL) {
+                                       p++;
+                               } else {
+                                       vp = *findvar(hashvar(name), name);
+                                       if (vp) {
+                                               vp->flags |= flag;
+                                               continue;
+                                       }
+                               }
+                               setvar(name, p, flag);
+                       } while ((name = *++aptr) != NULL);
+                       return 0;
+               }
        }
+       showvars(argv[0], flag, 0);
        return 0;
 }
 
-
 /*
- * Called after a function returns.
- * Interrupts must be off.
+ * Delete a function if it exists.
  */
-
 static void
-poplocalvars(void)
+unsetfunc(const char *name)
 {
-       struct localvar *lvp;
-       struct var *vp;
+       struct tblentry *cmdp;
 
-       while ((lvp = localvars) != NULL) {
-               localvars = lvp->next;
-               vp = lvp->vp;
-               TRACE(("poplocalvar %s", vp ? vp->text : "-"));
-               if (vp == NULL) {       /* $- saved */
-                       memcpy(optlist, lvp->text, sizeof(optlist));
-                       ckfree(lvp->text);
-                       optschanged();
-               } else if ((lvp->flags & (VUNSET|VSTRFIXED)) == VUNSET) {
-                       unsetvar(vp->text);
-               } else {
-                       if (vp->func)
-                               (*vp->func)(strchrnul(lvp->text, '=') + 1);
-                       if ((vp->flags & (VTEXTFIXED|VSTACK)) == 0)
-                               ckfree(vp->text);
-                       vp->flags = lvp->flags;
-                       vp->text = lvp->text;
-               }
-               ckfree(lvp);
-       }
+       cmdp = cmdlookup(name, 0);
+       if (cmdp!= NULL && cmdp->cmdtype == CMDFUNCTION)
+               delete_cmd_entry();
 }
 
-
 /*
  * The unset builtin command.  We unset the function before we unset the
  * variable to allow a function to be unset when there is a readonly variable
  * with the same name.
  */
-
-int
+static int
 unsetcmd(int argc, char **argv)
 {
        char **ap;
@@ -12358,7 +11364,7 @@ unsetcmd(int argc, char **argv)
                flag = i;
        }
 
-       for (ap = argptr; *ap ; ap++) {
+       for (ap = argptr; *ap; ap++) {
                if (flag != 'f') {
                        i = unsetvar(*ap);
                        ret |= i;
@@ -12372,115 +11378,11 @@ unsetcmd(int argc, char **argv)
 }
 
 
-/*
- * Unset the specified variable.
- */
-
-int
-unsetvar(const char *s)
-{
-       struct var **vpp;
-       struct var *vp;
-       int retval;
-
-       vpp = findvar(hashvar(s), s);
-       vp = *vpp;
-       retval = 2;
-       if (vp) {
-               int flags = vp->flags;
-
-               retval = 1;
-               if (flags & VREADONLY)
-                       goto out;
-#ifdef DYNAMIC_VAR
-               vp->flags &= ~VDYNAMIC;
-#endif
-               if (flags & VUNSET)
-                       goto ok;
-               if ((flags & VSTRFIXED) == 0) {
-                       INTOFF;
-                       if ((flags & (VTEXTFIXED|VSTACK)) == 0)
-                               ckfree(vp->text);
-                       *vpp = vp->next;
-                       ckfree(vp);
-                       INTON;
-               } else {
-                       setvar(s, 0, 0);
-                       vp->flags &= ~VEXPORT;
-               }
-ok:
-               retval = 0;
-       }
-
-out:
-       return retval;
-}
-
-
-
-/*
- * Find the appropriate entry in the hash table from the name.
- */
-
-static struct var **
-hashvar(const char *p)
-{
-       unsigned int hashval;
-
-       hashval = ((unsigned char) *p) << 4;
-       while (*p && *p != '=')
-               hashval += (unsigned char) *p++;
-       return &vartab[hashval % VTABSIZE];
-}
-
-
-
-/*
- * Compares two strings up to the first = or '\0'.  The first
- * string must be terminated by '='; the second may be terminated by
- * either '=' or '\0'.
- */
-
-int
-varcmp(const char *p, const char *q)
-{
-       int c, d;
-
-       while ((c = *p) == (d = *q)) {
-               if (!c || c == '=')
-                       goto out;
-               p++;
-               q++;
-       }
-       if (c == '=')
-               c = 0;
-       if (d == '=')
-               d = 0;
-out:
-       return c - d;
-}
-
-static int
-vpcmp(const void *a, const void *b)
-{
-       return varcmp(*(const char **)a, *(const char **)b);
-}
-
-static struct var **
-findvar(struct var **vpp, const char *name)
-{
-       for (; *vpp; vpp = &(*vpp)->next) {
-               if (varequal((*vpp)->text, name)) {
-                       break;
-               }
-       }
-       return vpp;
-}
 /*      setmode.c      */
 
 #include <sys/times.h>
 
-static const unsigned char timescmd_str[] = {
+static const unsigned char timescmd_str[] ALIGN1 = {
        ' ',  offsetof(struct tms, tms_utime),
        '\n', offsetof(struct tms, tms_stime),
        ' ',  offsetof(struct tms, tms_cutime),
@@ -12488,9 +11390,10 @@ static const unsigned char timescmd_str[] = {
        0
 };
 
-static int timescmd(int ac, char **av)
+static int
+timescmd(int ac, char **av)
 {
-       long int clk_tck, s, t;
+       long clk_tck, s, t;
        const unsigned char *p;
        struct tms buf;
 
@@ -12510,38 +11413,35 @@ static int timescmd(int ac, char **av)
        return 0;
 }
 
-#ifdef CONFIG_ASH_MATH_SUPPORT
+#if ENABLE_ASH_MATH_SUPPORT
 static arith_t
 dash_arith(const char *s)
 {
        arith_t result;
        int errcode = 0;
 
-       INTOFF;
+       INT_OFF;
        result = arith(s, &errcode);
        if (errcode < 0) {
                if (errcode == -3)
-                       sh_error("exponent less than 0");
-               else if (errcode == -2)
-                       sh_error("divide by zero");
-               else if (errcode == -5)
-                       sh_error("expression recursion loop detected");
-               else
-                       synerror(s);
+                       ash_msg_and_raise_error("exponent less than 0");
+               if (errcode == -2)
+                       ash_msg_and_raise_error("divide by zero");
+               if (errcode == -5)
+                       ash_msg_and_raise_error("expression recursion loop detected");
+               raise_error_syntax(s);
        }
-       INTON;
+       INT_ON;
 
        return result;
 }
 
-
 /*
  *  The let builtin. partial stolen from GNU Bash, the Bourne Again SHell.
  *  Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.
  *
  *  Copyright (C) 2003 Vladimir Oleynik <dzo@simtreas.ru>
  */
-
 static int
 letcmd(int argc, char **argv)
 {
@@ -12549,30 +11449,27 @@ letcmd(int argc, char **argv)
        arith_t i = 0;
 
        ap = argv + 1;
-       if(!*ap)
-               sh_error("expression expected");
+       if (!*ap)
+               ash_msg_and_raise_error("expression expected");
        for (ap = argv + 1; *ap; ap++) {
                i = dash_arith(*ap);
        }
 
        return !i;
 }
-#endif /* CONFIG_ASH_MATH_SUPPORT */
+#endif /* ASH_MATH_SUPPORT */
 
-/*      miscbltin.c  */
 
-/*
+/* ============ miscbltin.c
+ *
  * Miscellaneous builtins.
  */
 
 #undef rflag
 
-#ifdef __GLIBC__
-#if __GLIBC__ == 2 && __GLIBC_MINOR__ < 1
+#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ < 1
 typedef enum __rlimit_resource rlim_t;
 #endif
-#endif
-
 
 /*
  * The read builtin.  The -e option causes backslashes to escape the
@@ -12580,7 +11477,6 @@ typedef enum __rlimit_resource rlim_t;
  *
  * This uses unbuffered input, which may be avoidable in some cases.
  */
-
 static int
 readcmd(int argc, char **argv)
 {
@@ -12594,13 +11490,13 @@ readcmd(int argc, char **argv)
        int startword;
        int status;
        int i;
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
        int nch_flag = 0;
        int nchars = 0;
        int silent = 0;
        struct termios tty, old_tty;
 #endif
-#if defined(CONFIG_ASH_READ_TIMEOUT)
+#if ENABLE_ASH_READ_TIMEOUT
        fd_set set;
        struct timeval ts;
 
@@ -12609,32 +11505,32 @@ readcmd(int argc, char **argv)
 
        rflag = 0;
        prompt = NULL;
-#if defined(CONFIG_ASH_READ_NCHARS) && defined(CONFIG_ASH_READ_TIMEOUT)
+#if ENABLE_ASH_READ_NCHARS && ENABLE_ASH_READ_TIMEOUT
        while ((i = nextopt("p:rt:n:s")) != '\0')
-#elif defined(CONFIG_ASH_READ_NCHARS)
+#elif ENABLE_ASH_READ_NCHARS
        while ((i = nextopt("p:rn:s")) != '\0')
-#elif defined(CONFIG_ASH_READ_TIMEOUT)
+#elif ENABLE_ASH_READ_TIMEOUT
        while ((i = nextopt("p:rt:")) != '\0')
 #else
        while ((i = nextopt("p:r")) != '\0')
 #endif
        {
-               switch(i) {
+               switch (i) {
                case 'p':
                        prompt = optionarg;
                        break;
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
                case 'n':
                        nchars = strtol(optionarg, &p, 10);
                        if (*p)
-                               sh_error("invalid count");
+                               ash_msg_and_raise_error("invalid count");
                        nch_flag = (nchars > 0);
                        break;
                case 's':
                        silent = 1;
                        break;
 #endif
-#if defined(CONFIG_ASH_READ_TIMEOUT)
+#if ENABLE_ASH_READ_TIMEOUT
                case 't':
                        ts.tv_sec = strtol(optionarg, &p, 10);
                        ts.tv_usec = 0;
@@ -12644,19 +11540,19 @@ readcmd(int argc, char **argv)
                                        int scale;
                                        ts.tv_usec = strtol(p, &p2, 10);
                                        if (*p2)
-                                               sh_error("invalid timeout");
+                                               ash_msg_and_raise_error("invalid timeout");
                                        scale = p2 - p;
                                        /* normalize to usec */
                                        if (scale > 6)
-                                               sh_error("invalid timeout");
+                                               ash_msg_and_raise_error("invalid timeout");
                                        while (scale++ < 6)
                                                ts.tv_usec *= 10;
                                }
                        } else if (*p) {
-                               sh_error("invalid timeout");
+                               ash_msg_and_raise_error("invalid timeout");
                        }
                        if ( ! ts.tv_sec && ! ts.tv_usec)
-                               sh_error("invalid timeout");
+                               ash_msg_and_raise_error("invalid timeout");
                        break;
 #endif
                case 'r':
@@ -12669,33 +11565,36 @@ readcmd(int argc, char **argv)
        if (prompt && isatty(0)) {
                out2str(prompt);
        }
-       if (*(ap = argptr) == NULL)
-               sh_error("arg count");
-       if ((ifs = bltinlookup("IFS")) == NULL)
+       ap = argptr;
+       if (*ap == NULL)
+               ash_msg_and_raise_error("arg count");
+       ifs = bltinlookup("IFS");
+       if (ifs == NULL)
                ifs = defifs;
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
        if (nch_flag || silent) {
                tcgetattr(0, &tty);
                old_tty = tty;
                if (nch_flag) {
-                   tty.c_lflag &= ~ICANON;
-                   tty.c_cc[VMIN] = nchars;
+                       tty.c_lflag &= ~ICANON;
+                       tty.c_cc[VMIN] = nchars;
                }
                if (silent) {
-                   tty.c_lflag &= ~(ECHO|ECHOK|ECHONL);
+                       tty.c_lflag &= ~(ECHO|ECHOK|ECHONL);
 
                }
                tcsetattr(0, TCSANOW, &tty);
        }
 #endif
-#if defined(CONFIG_ASH_READ_TIMEOUT)
+#if ENABLE_ASH_READ_TIMEOUT
        if (ts.tv_sec || ts.tv_usec) {
-               FD_ZERO (&set);
-               FD_SET (0, &set);
+// TODO: replace with poll, it is smaller
+               FD_ZERO(&set);
+               FD_SET(0, &set);
 
-               i = select (FD_SETSIZE, &set, NULL, NULL, &ts);
+               i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
                if (!i) {
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
                        if (nch_flag)
                                tcsetattr(0, TCSANOW, &old_tty);
 #endif
@@ -12707,7 +11606,7 @@ readcmd(int argc, char **argv)
        startword = 1;
        backslash = 0;
        STARTSTACKSTR(p);
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
        while (!nch_flag || nchars--)
 #else
        for (;;)
@@ -12742,11 +11641,11 @@ readcmd(int argc, char **argv)
                        startword = 1;
                        STARTSTACKSTR(p);
                } else {
-put:
+ put:
                        STPUTC(c, p);
                }
        }
-#if defined(CONFIG_ASH_READ_NCHARS)
+#if ENABLE_ASH_READ_NCHARS
        if (nch_flag || silent)
                tcsetattr(0, TCSANOW, &old_tty);
 #endif
@@ -12761,12 +11660,12 @@ put:
        return status;
 }
 
-
-static int umaskcmd(int argc, char **argv)
+static int
+umaskcmd(int argc, char **argv)
 {
-       static const char permuser[3] = "ugo";
-       static const char permmode[3] = "rwx";
-       static const short int permmask[] = {
+       static const char permuser[3] ALIGN1 = "ugo";
+       static const char permmode[3] ALIGN1 = "rwx";
+       static const short permmask[] ALIGN2 = {
                S_IRUSR, S_IWUSR, S_IXUSR,
                S_IRGRP, S_IWGRP, S_IXGRP,
                S_IROTH, S_IWOTH, S_IXOTH
@@ -12781,12 +11680,13 @@ static int umaskcmd(int argc, char **argv)
                symbolic_mode = 1;
        }
 
-       INTOFF;
+       INT_OFF;
        mask = umask(0);
        umask(mask);
-       INTON;
+       INT_ON;
 
-       if ((ap = *argptr) == NULL) {
+       ap = *argptr;
+       if (ap == NULL) {
                if (symbolic_mode) {
                        char buf[18];
                        char *p = buf;
@@ -12809,18 +11709,18 @@ static int umaskcmd(int argc, char **argv)
                        out1fmt("%.4o\n", mask);
                }
        } else {
-               if (is_digit((unsigned char) *ap)) {
+               if (isdigit((unsigned char) *ap)) {
                        mask = 0;
                        do {
                                if (*ap >= '8' || *ap < '0')
-                                       sh_error(illnum, argv[1]);
+                                       ash_msg_and_raise_error(illnum, argv[1]);
                                mask = (mask << 3) + (*ap - '0');
                        } while (*++ap != '\0');
                        umask(mask);
                } else {
                        mask = ~mask & 0777;
                        if (!bb_parse_mode(ap, &mask)) {
-                               sh_error("Illegal mode: %s", ap);
+                               ash_msg_and_raise_error("illegal mode: %s", ap);
                        }
                        umask(~mask & 0777);
                }
@@ -12879,12 +11779,13 @@ static const struct limits limits[] = {
 #ifdef RLIMIT_LOCKS
        { "locks",                      RLIMIT_LOCKS,      1, 'w' },
 #endif
-       { (char *) 0,                   0,                 0,  '\0' }
+       { NULL,                         0,                 0,  '\0' }
 };
 
 enum limtype { SOFT = 0x1, HARD = 0x2 };
 
-static void printlim(enum limtype how, const struct rlimit *limit,
+static void
+printlim(enum limtype how, const struct rlimit *limit,
                        const struct limits *l)
 {
        rlim_t val;
@@ -12901,16 +11802,16 @@ static void printlim(enum limtype how, const struct rlimit *limit,
        }
 }
 
-int
+static int
 ulimitcmd(int argc, char **argv)
 {
-       int     c;
+       int c;
        rlim_t val = 0;
        enum limtype how = SOFT | HARD;
-       const struct limits     *l;
-       int             set, all = 0;
-       int             optc, what;
-       struct rlimit   limit;
+       const struct limits *l;
+       int set, all = 0;
+       int optc, what;
+       struct rlimit limit;
 
        what = 'f';
        while ((optc = nextopt("HSa"
@@ -12947,7 +11848,7 @@ ulimitcmd(int argc, char **argv)
 #ifdef RLIMIT_LOCKS
                                "w"
 #endif
-                                               )) != '\0')
+                                       )) != '\0')
                switch (optc) {
                case 'H':
                        how = HARD;
@@ -12970,20 +11871,19 @@ ulimitcmd(int argc, char **argv)
                char *p = *argptr;
 
                if (all || argptr[1])
-                       sh_error("too many arguments");
+                       ash_msg_and_raise_error("too many arguments");
                if (strncmp(p, "unlimited\n", 9) == 0)
                        val = RLIM_INFINITY;
                else {
                        val = (rlim_t) 0;
 
-                       while ((c = *p++) >= '0' && c <= '9')
-                       {
+                       while ((c = *p++) >= '0' && c <= '9') {
                                val = (val * 10) + (long)(c - '0');
                                if (val < (rlim_t) 0)
                                        break;
                        }
                        if (c)
-                               sh_error("bad number");
+                               ash_msg_and_raise_error("bad number");
                        val *= l->factor;
                }
        }
@@ -13003,7 +11903,7 @@ ulimitcmd(int argc, char **argv)
                if (how & SOFT)
                        limit.rlim_cur = val;
                if (setrlimit(l->cmd, &limit) < 0)
-                       sh_error("error setting limit (%m)");
+                       ash_msg_and_raise_error("error setting limit (%m)");
        } else {
                printlim(how, &limit, l);
        }
@@ -13011,7 +11911,9 @@ ulimitcmd(int argc, char **argv)
 }
 
 
-#ifdef CONFIG_ASH_MATH_SUPPORT
+/* ============ Math support */
+
+#if ENABLE_ASH_MATH_SUPPORT
 
 /* Copyright (c) 2001 Aaron Lehmann <aaronl@vitelus.com>
 
@@ -13107,11 +12009,9 @@ ulimitcmd(int argc, char **argv)
  * - always use special isspace(), see comment from bash ;-)
  */
 
-
 #define arith_isspace(arithval) \
        (arithval == ' ' || arithval == '\n' || arithval == '\t')
 
-
 typedef unsigned char operator;
 
 /* An operator's token id is a bit of a bitfield. The lower 5 bits are the
@@ -13141,7 +12041,7 @@ typedef unsigned char operator;
 #define TOK_REM_ASSIGN tok_decl(3,2)
 
 /* all assign is right associativity and precedence eq, but (7+3)<<5 > 256 */
-#define convert_prec_is_assing(prec) do { if(prec == 3) prec = 2; } while(0)
+#define convert_prec_is_assing(prec) do { if (prec == 3) prec = 2; } while (0)
 
 /* conditional is right associativity too */
 #define TOK_CONDITIONAL tok_decl(4,0)
@@ -13203,7 +12103,8 @@ typedef unsigned char operator;
 
 #define NUMPTR (*numstackptr)
 
-static int tok_have_assign(operator op)
+static int
+tok_have_assign(operator op)
 {
        operator prec = PREC(op);
 
@@ -13212,13 +12113,13 @@ static int tok_have_assign(operator op)
                        prec == PREC_PRE || prec == PREC_POST);
 }
 
-static int is_right_associativity(operator prec)
+static int
+is_right_associativity(operator prec)
 {
-    return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT) ||
-           prec == PREC(TOK_CONDITIONAL));
+       return (prec == PREC(TOK_ASSIGN) || prec == PREC(TOK_EXPONENT)
+               || prec == PREC(TOK_CONDITIONAL));
 }
 
-
 typedef struct ARITCH_VAR_NUM {
        arith_t val;
        arith_t contidional_second_val;
@@ -13227,7 +12128,6 @@ typedef struct ARITCH_VAR_NUM {
                           else is variable name */
 } v_n_t;
 
-
 typedef struct CHK_VAR_RECURSIVE_LOOPED {
        const char *var;
        struct CHK_VAR_RECURSIVE_LOOPED *next;
@@ -13235,59 +12135,59 @@ typedef struct CHK_VAR_RECURSIVE_LOOPED {
 
 static chk_var_recursive_looped_t *prev_chk_var_recursive;
 
-
-static int arith_lookup_val(v_n_t *t)
+static int
+arith_lookup_val(v_n_t *t)
 {
-    if(t->var) {
-       const char * p = lookupvar(t->var);
+       if (t->var) {
+               const char * p = lookupvar(t->var);
 
-       if(p) {
-           int errcode;
+               if (p) {
+                       int errcode;
 
-           /* recursive try as expression */
-           chk_var_recursive_looped_t *cur;
-           chk_var_recursive_looped_t cur_save;
+                       /* recursive try as expression */
+                       chk_var_recursive_looped_t *cur;
+                       chk_var_recursive_looped_t cur_save;
 
-           for(cur = prev_chk_var_recursive; cur; cur = cur->next) {
-               if(strcmp(cur->var, t->var) == 0) {
-                   /* expression recursion loop detected */
-                   return -5;
-               }
-           }
-           /* save current lookuped var name */
-           cur = prev_chk_var_recursive;
-           cur_save.var = t->var;
-           cur_save.next = cur;
-           prev_chk_var_recursive = &cur_save;
+                       for (cur = prev_chk_var_recursive; cur; cur = cur->next) {
+                               if (strcmp(cur->var, t->var) == 0) {
+                                       /* expression recursion loop detected */
+                                       return -5;
+                               }
+                       }
+                       /* save current lookuped var name */
+                       cur = prev_chk_var_recursive;
+                       cur_save.var = t->var;
+                       cur_save.next = cur;
+                       prev_chk_var_recursive = &cur_save;
 
-           t->val = arith (p, &errcode);
-           /* restore previous ptr after recursiving */
-           prev_chk_var_recursive = cur;
-           return errcode;
-       } else {
-           /* allow undefined var as 0 */
-           t->val = 0;
+                       t->val = arith (p, &errcode);
+                       /* restore previous ptr after recursiving */
+                       prev_chk_var_recursive = cur;
+                       return errcode;
+               }
+               /* allow undefined var as 0 */
+               t->val = 0;
        }
-    }
-    return 0;
+       return 0;
 }
 
 /* "applying" a token means performing it on the top elements on the integer
  * stack. For a unary operator it will only change the top element, but a
  * binary operator will pop two arguments and push a result */
-static int arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
+static int
+arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
 {
        v_n_t *numptr_m1;
        arith_t numptr_val, rez;
        int ret_arith_lookup_val;
 
-       if (NUMPTR == numstack) goto err; /* There is no operator that can work
-                                                                                without arguments */
+       /* There is no operator that can work without arguments */
+       if (NUMPTR == numstack) goto err;
        numptr_m1 = NUMPTR - 1;
 
        /* check operand is var with noninteger value */
        ret_arith_lookup_val = arith_lookup_val(numptr_m1);
-       if(ret_arith_lookup_val)
+       if (ret_arith_lookup_val)
                return ret_arith_lookup_val;
 
        rez = numptr_m1->val;
@@ -13304,116 +12204,113 @@ static int arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
        else if (op != TOK_UPLUS) {
                /* Binary operators */
 
-           /* check and binary operators need two arguments */
-           if (numptr_m1 == numstack) goto err;
-
-           /* ... and they pop one */
-           --NUMPTR;
-           numptr_val = rez;
-           if (op == TOK_CONDITIONAL) {
-               if(! numptr_m1->contidional_second_val_initialized) {
-                   /* protect $((expr1 ? expr2)) without ": expr" */
-                   goto err;
-               }
-               rez = numptr_m1->contidional_second_val;
-           } else if(numptr_m1->contidional_second_val_initialized) {
-                   /* protect $((expr1 : expr2)) without "expr ? " */
-                   goto err;
-           }
-           numptr_m1 = NUMPTR - 1;
-           if(op != TOK_ASSIGN) {
-               /* check operand is var with noninteger value for not '=' */
-               ret_arith_lookup_val = arith_lookup_val(numptr_m1);
-               if(ret_arith_lookup_val)
-                   return ret_arith_lookup_val;
-           }
-           if (op == TOK_CONDITIONAL) {
-                   numptr_m1->contidional_second_val = rez;
-           }
-           rez = numptr_m1->val;
-           if (op == TOK_BOR || op == TOK_OR_ASSIGN)
+               /* check and binary operators need two arguments */
+               if (numptr_m1 == numstack) goto err;
+
+               /* ... and they pop one */
+               --NUMPTR;
+               numptr_val = rez;
+               if (op == TOK_CONDITIONAL) {
+                       if (! numptr_m1->contidional_second_val_initialized) {
+                               /* protect $((expr1 ? expr2)) without ": expr" */
+                               goto err;
+                       }
+                       rez = numptr_m1->contidional_second_val;
+               } else if (numptr_m1->contidional_second_val_initialized) {
+                       /* protect $((expr1 : expr2)) without "expr ? " */
+                       goto err;
+               }
+               numptr_m1 = NUMPTR - 1;
+               if (op != TOK_ASSIGN) {
+                       /* check operand is var with noninteger value for not '=' */
+                       ret_arith_lookup_val = arith_lookup_val(numptr_m1);
+                       if (ret_arith_lookup_val)
+                               return ret_arith_lookup_val;
+               }
+               if (op == TOK_CONDITIONAL) {
+                       numptr_m1->contidional_second_val = rez;
+               }
+               rez = numptr_m1->val;
+               if (op == TOK_BOR || op == TOK_OR_ASSIGN)
                        rez |= numptr_val;
-           else if (op == TOK_OR)
+               else if (op == TOK_OR)
                        rez = numptr_val || rez;
-           else if (op == TOK_BAND || op == TOK_AND_ASSIGN)
+               else if (op == TOK_BAND || op == TOK_AND_ASSIGN)
                        rez &= numptr_val;
-           else if (op == TOK_BXOR || op == TOK_XOR_ASSIGN)
+               else if (op == TOK_BXOR || op == TOK_XOR_ASSIGN)
                        rez ^= numptr_val;
-           else if (op == TOK_AND)
+               else if (op == TOK_AND)
                        rez = rez && numptr_val;
-           else if (op == TOK_EQ)
+               else if (op == TOK_EQ)
                        rez = (rez == numptr_val);
-           else if (op == TOK_NE)
+               else if (op == TOK_NE)
                        rez = (rez != numptr_val);
-           else if (op == TOK_GE)
+               else if (op == TOK_GE)
                        rez = (rez >= numptr_val);
-           else if (op == TOK_RSHIFT || op == TOK_RSHIFT_ASSIGN)
+               else if (op == TOK_RSHIFT || op == TOK_RSHIFT_ASSIGN)
                        rez >>= numptr_val;
-           else if (op == TOK_LSHIFT || op == TOK_LSHIFT_ASSIGN)
+               else if (op == TOK_LSHIFT || op == TOK_LSHIFT_ASSIGN)
                        rez <<= numptr_val;
-           else if (op == TOK_GT)
+               else if (op == TOK_GT)
                        rez = (rez > numptr_val);
-           else if (op == TOK_LT)
+               else if (op == TOK_LT)
                        rez = (rez < numptr_val);
-           else if (op == TOK_LE)
+               else if (op == TOK_LE)
                        rez = (rez <= numptr_val);
-           else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
+               else if (op == TOK_MUL || op == TOK_MUL_ASSIGN)
                        rez *= numptr_val;
-           else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN)
+               else if (op == TOK_ADD || op == TOK_PLUS_ASSIGN)
                        rez += numptr_val;
-           else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN)
+               else if (op == TOK_SUB || op == TOK_MINUS_ASSIGN)
                        rez -= numptr_val;
-           else if (op == TOK_ASSIGN || op == TOK_COMMA)
+               else if (op == TOK_ASSIGN || op == TOK_COMMA)
                        rez = numptr_val;
-           else if (op == TOK_CONDITIONAL_SEP) {
+               else if (op == TOK_CONDITIONAL_SEP) {
                        if (numptr_m1 == numstack) {
-                           /* protect $((expr : expr)) without "expr ? " */
-                           goto err;
+                               /* protect $((expr : expr)) without "expr ? " */
+                               goto err;
                        }
                        numptr_m1->contidional_second_val_initialized = op;
                        numptr_m1->contidional_second_val = numptr_val;
-           }
-           else if (op == TOK_CONDITIONAL) {
+               } else if (op == TOK_CONDITIONAL) {
                        rez = rez ?
-                             numptr_val : numptr_m1->contidional_second_val;
-           }
-           else if(op == TOK_EXPONENT) {
-                       if(numptr_val < 0)
+                               numptr_val : numptr_m1->contidional_second_val;
+               } else if (op == TOK_EXPONENT) {
+                       if (numptr_val < 0)
                                return -3;      /* exponent less than 0 */
                        else {
                                arith_t c = 1;
 
-                               if(numptr_val)
-                                       while(numptr_val--)
+                               if (numptr_val)
+                                       while (numptr_val--)
                                                c *= rez;
                                rez = c;
                        }
-           }
-           else if(numptr_val==0)          /* zero divisor check */
+               } else if (numptr_val==0)          /* zero divisor check */
                        return -2;
-           else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
+               else if (op == TOK_DIV || op == TOK_DIV_ASSIGN)
                        rez /= numptr_val;
-           else if (op == TOK_REM || op == TOK_REM_ASSIGN)
+               else if (op == TOK_REM || op == TOK_REM_ASSIGN)
                        rez %= numptr_val;
        }
-       if(tok_have_assign(op)) {
-               char buf[32];
+       if (tok_have_assign(op)) {
+               char buf[sizeof(arith_t_type)*3 + 2];
 
-               if(numptr_m1->var == NULL) {
+               if (numptr_m1->var == NULL) {
                        /* Hmm, 1=2 ? */
                        goto err;
                }
                /* save to shell variable */
-#ifdef CONFIG_ASH_MATH_SUPPORT_64
-               snprintf(buf, sizeof(buf), "%lld", arith_t_type rez);
+#if ENABLE_ASH_MATH_SUPPORT_64
+               snprintf(buf, sizeof(buf), "%lld", (arith_t_type) rez);
 #else
-               snprintf(buf, sizeof(buf), "%ld", arith_t_type rez);
+               snprintf(buf, sizeof(buf), "%ld", (arith_t_type) rez);
 #endif
                setvar(numptr_m1->var, buf, 0);
                /* after saving, make previous value for v++ or v-- */
-               if(op == TOK_POST_INC)
+               if (op == TOK_POST_INC)
                        rez--;
-               else if(op == TOK_POST_DEC)
+               else if (op == TOK_POST_DEC)
                        rez++;
        }
        numptr_m1->val = rez;
@@ -13424,8 +12321,8 @@ static int arith_apply(operator op, v_n_t *numstack, v_n_t **numstackptr)
        return -1;
 }
 
-/* longest must first */
-static const char op_tokens[] = {
+/* longest must be first */
+static const char op_tokens[] ALIGN1 = {
        '<','<','=',0, TOK_LSHIFT_ASSIGN,
        '>','>','=',0, TOK_RSHIFT_ASSIGN,
        '<','<',    0, TOK_LSHIFT,
@@ -13471,105 +12368,109 @@ static const char op_tokens[] = {
 /* ptr to ")" */
 #define endexpression &op_tokens[sizeof(op_tokens)-7]
 
-
-static arith_t arith (const char *expr, int *perrcode)
+static arith_t
+arith(const char *expr, int *perrcode)
 {
-    char arithval; /* Current character under analysis */
-    operator lasttok, op;
-    operator prec;
+       char arithval; /* Current character under analysis */
+       operator lasttok, op;
+       operator prec;
 
-    const char *p = endexpression;
-    int errcode;
+       const char *p = endexpression;
+       int errcode;
 
-    size_t datasizes = strlen(expr) + 2;
+       size_t datasizes = strlen(expr) + 2;
 
-    /* Stack of integers */
-    /* The proof that there can be no more than strlen(startbuf)/2+1 integers
-     * in any given correct or incorrect expression is left as an exercise to
-     * the reader. */
-    v_n_t *numstack = alloca(((datasizes)/2)*sizeof(v_n_t)),
-           *numstackptr = numstack;
-    /* Stack of operator tokens */
-    operator *stack = alloca((datasizes) * sizeof(operator)),
-           *stackptr = stack;
+       /* Stack of integers */
+       /* The proof that there can be no more than strlen(startbuf)/2+1 integers
+        * in any given correct or incorrect expression is left as an exercise to
+        * the reader. */
+       v_n_t *numstack = alloca(((datasizes)/2)*sizeof(v_n_t)),
+                               *numstackptr = numstack;
+       /* Stack of operator tokens */
+       operator *stack = alloca((datasizes) * sizeof(operator)),
+                               *stackptr = stack;
+
+       *stackptr++ = lasttok = TOK_LPAREN;     /* start off with a left paren */
+       *perrcode = errcode = 0;
+
+       while (1) {
+               arithval = *expr;
+               if (arithval == 0) {
+                       if (p == endexpression) {
+                               /* Null expression. */
+                               return 0;
+                       }
 
-    *stackptr++ = lasttok = TOK_LPAREN;     /* start off with a left paren */
-    *perrcode = errcode = 0;
+                       /* This is only reached after all tokens have been extracted from the
+                        * input stream. If there are still tokens on the operator stack, they
+                        * are to be applied in order. At the end, there should be a final
+                        * result on the integer stack */
 
-    while(1) {
-       if ((arithval = *expr) == 0) {
-               if (p == endexpression) {
-                       /* Null expression. */
-                       return 0;
+                       if (expr != endexpression + 1) {
+                               /* If we haven't done so already, */
+                               /* append a closing right paren */
+                               expr = endexpression;
+                               /* and let the loop process it. */
+                               continue;
+                       }
+                       /* At this point, we're done with the expression. */
+                       if (numstackptr != numstack+1) {
+                               /* ... but if there isn't, it's bad */
+ err:
+                               return (*perrcode = -1);
+                       }
+                       if (numstack->var) {
+                               /* expression is $((var)) only, lookup now */
+                               errcode = arith_lookup_val(numstack);
+                       }
+ ret:
+                       *perrcode = errcode;
+                       return numstack->val;
                }
 
-               /* This is only reached after all tokens have been extracted from the
-                * input stream. If there are still tokens on the operator stack, they
-                * are to be applied in order. At the end, there should be a final
-                * result on the integer stack */
-
-               if (expr != endexpression + 1) {
-                       /* If we haven't done so already, */
-                       /* append a closing right paren */
-                       expr = endexpression;
-                       /* and let the loop process it. */
-                       continue;
-               }
-               /* At this point, we're done with the expression. */
-               if (numstackptr != numstack+1) {
-                       /* ... but if there isn't, it's bad */
-                 err:
-                       return (*perrcode = -1);
-               }
-               if(numstack->var) {
-                   /* expression is $((var)) only, lookup now */
-                   errcode = arith_lookup_val(numstack);
-               }
-       ret:
-               *perrcode = errcode;
-               return numstack->val;
-       } else {
                /* Continue processing the expression. */
                if (arith_isspace(arithval)) {
                        /* Skip whitespace */
                        goto prologue;
                }
-               if((p = endofname(expr)) != expr) {
+               p = endofname(expr);
+               if (p != expr) {
                        size_t var_name_size = (p-expr) + 1;  /* trailing zero */
 
                        numstackptr->var = alloca(var_name_size);
                        safe_strncpy(numstackptr->var, expr, var_name_size);
                        expr = p;
              num:
+ num:
                        numstackptr->contidional_second_val_initialized = 0;
                        numstackptr++;
                        lasttok = TOK_NUM;
                        continue;
-               } else if (is_digit(arithval)) {
+               }
+               if (isdigit(arithval)) {
                        numstackptr->var = NULL;
-#ifdef CONFIG_ASH_MATH_SUPPORT_64
+#if ENABLE_ASH_MATH_SUPPORT_64
                        numstackptr->val = strtoll(expr, (char **) &expr, 0);
 #else
                        numstackptr->val = strtol(expr, (char **) &expr, 0);
 #endif
                        goto num;
                }
-               for(p = op_tokens; ; p++) {
+               for (p = op_tokens; ; p++) {
                        const char *o;
 
-                       if(*p == 0) {
+                       if (*p == 0) {
                                /* strange operator not found */
                                goto err;
                        }
-                       for(o = expr; *p && *o == *p; p++)
+                       for (o = expr; *p && *o == *p; p++)
                                o++;
-                       if(! *p) {
+                       if (! *p) {
                                /* found */
                                expr = o - 1;
                                break;
                        }
                        /* skip tail uncompared token */
-                       while(*p)
+                       while (*p)
                                p++;
                        /* skip zero delim */
                        p++;
@@ -13577,27 +12478,27 @@ static arith_t arith (const char *expr, int *perrcode)
                op = p[1];
 
                /* post grammar: a++ reduce to num */
-               if(lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC)
-                   lasttok = TOK_NUM;
+               if (lasttok == TOK_POST_INC || lasttok == TOK_POST_DEC)
+                       lasttok = TOK_NUM;
 
                /* Plus and minus are binary (not unary) _only_ if the last
                 * token was as number, or a right paren (which pretends to be
                 * a number, since it evaluates to one). Think about it.
                 * It makes sense. */
                if (lasttok != TOK_NUM) {
-                       switch(op) {
-                               case TOK_ADD:
-                                   op = TOK_UPLUS;
-                                   break;
-                               case TOK_SUB:
-                                   op = TOK_UMINUS;
-                                   break;
-                               case TOK_POST_INC:
-                                   op = TOK_PRE_INC;
-                                   break;
-                               case TOK_POST_DEC:
-                                   op = TOK_PRE_DEC;
-                                   break;
+                       switch (op) {
+                       case TOK_ADD:
+                               op = TOK_UPLUS;
+                               break;
+                       case TOK_SUB:
+                               op = TOK_UMINUS;
+                               break;
+                       case TOK_POST_INC:
+                               op = TOK_PRE_INC;
+                               break;
+                       case TOK_POST_DEC:
+                               op = TOK_PRE_DEC;
+                               break;
                        }
                }
                /* We don't want a unary operator to cause recursive descent on the
@@ -13619,30 +12520,30 @@ static arith_t arith (const char *expr, int *perrcode)
                                goto err;
                        }
                        while (stackptr != stack) {
-                           if (op == TOK_RPAREN) {
-                               /* The algorithm employed here is simple: while we don't
-                                * hit an open paren nor the bottom of the stack, pop
-                                * tokens and apply them */
-                               if (stackptr[-1] == TOK_LPAREN) {
-                                   --stackptr;
-                                   /* Any operator directly after a */
-                                   lasttok = TOK_NUM;
-                                   /* close paren should consider itself binary */
-                                   goto prologue;
-                               }
-                           } else {
-                               operator prev_prec = PREC(stackptr[-1]);
+                               if (op == TOK_RPAREN) {
+                                       /* The algorithm employed here is simple: while we don't
+                                        * hit an open paren nor the bottom of the stack, pop
+                                        * tokens and apply them */
+                                       if (stackptr[-1] == TOK_LPAREN) {
+                                               --stackptr;
+                                               /* Any operator directly after a */
+                                               lasttok = TOK_NUM;
+                                               /* close paren should consider itself binary */
+                                               goto prologue;
+                                       }
+                               } else {
+                                       operator prev_prec = PREC(stackptr[-1]);
 
-                               convert_prec_is_assing(prec);
-                               convert_prec_is_assing(prev_prec);
-                               if (prev_prec < prec)
-                                       break;
-                               /* check right assoc */
-                               if(prev_prec == prec && is_right_associativity(prec))
-                                       break;
-                           }
-                           errcode = arith_apply(*--stackptr, numstack, &numstackptr);
-                           if(errcode) goto ret;
+                                       convert_prec_is_assing(prec);
+                                       convert_prec_is_assing(prev_prec);
+                                       if (prev_prec < prec)
+                                               break;
+                                       /* check right assoc */
+                                       if (prev_prec == prec && is_right_associativity(prec))
+                                               break;
+                               }
+                               errcode = arith_apply(*--stackptr, numstack, &numstackptr);
+                               if (errcode) goto ret;
                        }
                        if (op == TOK_RPAREN) {
                                goto err;
@@ -13651,14 +12552,314 @@ static arith_t arith (const char *expr, int *perrcode)
 
                /* Push this operator to the stack and remember it. */
                *stackptr++ = lasttok = op;
-
-         prologue:
+ prologue:
                ++expr;
+       } /* while */
+}
+#endif /* ASH_MATH_SUPPORT */
+
+
+/* ============ main() and helpers */
+
+/*
+ * Called to exit the shell.
+ */
+static void exitshell(void) ATTRIBUTE_NORETURN;
+static void
+exitshell(void)
+{
+       struct jmploc loc;
+       char *p;
+       int status;
+
+       status = exitstatus;
+       TRACE(("pid %d, exitshell(%d)\n", getpid(), status));
+       if (setjmp(loc.loc)) {
+               if (exception == EXEXIT)
+/* dash bug: it just does _exit(exitstatus) here
+ * but we have to do setjobctl(0) first!
+ * (bug is still not fixed in dash-0.5.3 - if you run dash
+ * under Midnight Commander, on exit from dash MC is backgrounded) */
+                       status = exitstatus;
+               goto out;
+       }
+       exception_handler = &loc;
+       p = trap[0];
+       if (p) {
+               trap[0] = NULL;
+               evalstring(p, 0);
+       }
+       flush_stdout_stderr();
+ out:
+       setjobctl(0);
+       _exit(status);
+       /* NOTREACHED */
+}
+
+static void
+init(void)
+{
+       /* from input.c: */
+       basepf.nextc = basepf.buf = basebuf;
+
+       /* from trap.c: */
+       signal(SIGCHLD, SIG_DFL);
+
+       /* from var.c: */
+       {
+               char **envp;
+               char ppid[sizeof(int)*3 + 1];
+               const char *p;
+               struct stat st1, st2;
+
+               initvar();
+               for (envp = environ; envp && *envp; envp++) {
+                       if (strchr(*envp, '=')) {
+                               setvareq(*envp, VEXPORT|VTEXTFIXED);
+                       }
+               }
+
+               snprintf(ppid, sizeof(ppid), "%u", (unsigned) getppid());
+               setvar("PPID", ppid, 0);
+
+               p = lookupvar("PWD");
+               if (p)
+                       if (*p != '/' || stat(p, &st1) || stat(".", &st2)
+                        || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino)
+                               p = '\0';
+               setpwd(p, 0);
+       }
+}
+
+/*
+ * Process the shell command line arguments.
+ */
+static void
+procargs(int argc, char **argv)
+{
+       int i;
+       const char *xminusc;
+       char **xargv;
+
+       xargv = argv;
+       arg0 = xargv[0];
+       if (argc > 0)
+               xargv++;
+       for (i = 0; i < NOPTS; i++)
+               optlist[i] = 2;
+       argptr = xargv;
+       options(1);
+       xargv = argptr;
+       xminusc = minusc;
+       if (*xargv == NULL) {
+               if (xminusc)
+                       ash_msg_and_raise_error(bb_msg_requires_arg, "-c");
+               sflag = 1;
+       }
+       if (iflag == 2 && sflag == 1 && isatty(0) && isatty(1))
+               iflag = 1;
+       if (mflag == 2)
+               mflag = iflag;
+       for (i = 0; i < NOPTS; i++)
+               if (optlist[i] == 2)
+                       optlist[i] = 0;
+#if DEBUG == 2
+       debug = 1;
+#endif
+       /* POSIX 1003.2: first arg after -c cmd is $0, remainder $1... */
+       if (xminusc) {
+               minusc = *xargv++;
+               if (*xargv)
+                       goto setarg0;
+       } else if (!sflag) {
+               setinputfile(*xargv, 0);
+ setarg0:
+               arg0 = *xargv++;
+               commandname = arg0;
+       }
+
+       shellparam.p = xargv;
+#if ENABLE_ASH_GETOPTS
+       shellparam.optind = 1;
+       shellparam.optoff = -1;
+#endif
+       /* assert(shellparam.malloc == 0 && shellparam.nparam == 0); */
+       while (*xargv) {
+               shellparam.nparam++;
+               xargv++;
        }
-    }
+       optschanged();
+}
+
+/*
+ * Read /etc/profile or .profile.
+ */
+static void
+read_profile(const char *name)
+{
+       int skip;
+
+       if (setinputfile(name, INPUT_PUSH_FILE | INPUT_NOFILE_OK) < 0)
+               return;
+       skip = cmdloop(0);
+       popfile();
+       if (skip)
+               exitshell();
+}
+
+/*
+ * This routine is called when an error or an interrupt occurs in an
+ * interactive shell and control is returned to the main command loop.
+ */
+static void
+reset(void)
+{
+       /* from eval.c: */
+       evalskip = 0;
+       loopnest = 0;
+       /* from input.c: */
+       parselleft = parsenleft = 0;      /* clear input buffer */
+       popallfiles();
+       /* from parser.c: */
+       tokpushback = 0;
+       checkkwd = 0;
+       /* from redir.c: */
+       clearredir(0);
 }
-#endif /* CONFIG_ASH_MATH_SUPPORT */
 
+#if PROFILE
+static short profile_buf[16384];
+extern int etext();
+#endif
+
+/*
+ * Main routine.  We initialize things, parse the arguments, execute
+ * profiles if we're a login shell, and then call cmdloop to execute
+ * commands.  The setjmp call sets up the location to jump to when an
+ * exception occurs.  When an exception occurs the variable "state"
+ * is used to figure out how far we had gotten.
+ */
+int ash_main(int argc, char **argv);
+int ash_main(int argc, char **argv)
+{
+       char *shinit;
+       volatile int state;
+       struct jmploc jmploc;
+       struct stackmark smark;
+
+#if PROFILE
+       monitor(4, etext, profile_buf, sizeof(profile_buf), 50);
+#endif
+
+#if ENABLE_FEATURE_EDITING
+       line_input_state = new_line_input_t(FOR_SHELL | WITH_PATH_LOOKUP);
+#endif
+       state = 0;
+       if (setjmp(jmploc.loc)) {
+               int e;
+               int s;
+
+               reset();
+
+               e = exception;
+               if (e == EXERROR)
+                       exitstatus = 2;
+               s = state;
+               if (e == EXEXIT || s == 0 || iflag == 0 || shlvl)
+                       exitshell();
+
+               if (e == EXINT) {
+                       outcslow('\n', stderr);
+               }
+               popstackmark(&smark);
+               FORCE_INT_ON; /* enable interrupts */
+               if (s == 1)
+                       goto state1;
+               if (s == 2)
+                       goto state2;
+               if (s == 3)
+                       goto state3;
+               goto state4;
+       }
+       exception_handler = &jmploc;
+#if DEBUG
+       opentrace();
+       trace_puts("Shell args: ");
+       trace_puts_args(argv);
+#endif
+       rootpid = getpid();
+
+#if ENABLE_ASH_RANDOM_SUPPORT
+       rseed = rootpid + time(NULL);
+#endif
+       init();
+       setstackmark(&smark);
+       procargs(argc, argv);
+#if ENABLE_FEATURE_EDITING_SAVEHISTORY
+       if (iflag) {
+               const char *hp = lookupvar("HISTFILE");
+
+               if (hp == NULL) {
+                       hp = lookupvar("HOME");
+                       if (hp != NULL) {
+                               char *defhp = concat_path_file(hp, ".ash_history");
+                               setvar("HISTFILE", defhp, 0);
+                               free(defhp);
+                       }
+               }
+       }
+#endif
+       if (argv[0] && argv[0][0] == '-')
+               isloginsh = 1;
+       if (isloginsh) {
+               state = 1;
+               read_profile("/etc/profile");
+ state1:
+               state = 2;
+               read_profile(".profile");
+       }
+ state2:
+       state = 3;
+       if (
+#ifndef linux
+        getuid() == geteuid() && getgid() == getegid() &&
+#endif
+        iflag
+       ) {
+               shinit = lookupvar("ENV");
+               if (shinit != NULL && *shinit != '\0') {
+                       read_profile(shinit);
+               }
+       }
+ state3:
+       state = 4;
+       if (minusc)
+               evalstring(minusc, 0);
+
+       if (sflag || minusc == NULL) {
+#if ENABLE_FEATURE_EDITING_SAVEHISTORY
+               if ( iflag ) {
+                       const char *hp = lookupvar("HISTFILE");
+
+                       if (hp != NULL)
+                               line_input_state->hist_file = hp;
+               }
+#endif
+ state4: /* XXX ??? - why isn't this before the "if" statement */
+               cmdloop(1);
+       }
+#if PROFILE
+       monitor(0);
+#endif
+#ifdef GPROF
+       {
+               extern void _mcleanup(void);
+               _mcleanup();
+       }
+#endif
+       exitshell();
+       /* NOTREACHED */
+}
 
 #if DEBUG
 const char *applet_name = "debug stuff usage";
@@ -13668,6 +12869,7 @@ int main(int argc, char **argv)
 }
 #endif
 
+
 /*-
  * Copyright (c) 1989, 1991, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.