1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * Arithmetic Expansion
42 * <(list) and >(list) Process Substitution
43 * Here Documents ( << word )
46 * Parameter Expansion for substring processing ${var#word} ${var%word}
48 * Bash stuff maybe optional enable:
49 * &> and >& redirection of stdout+stderr
51 * reserved words: [[ ]] function select
52 * substrings ${var:1:5}
55 * job handling woefully incomplete and buggy (improved --vda)
57 * port selected bugfixes from post-0.49 busybox lash - done?
58 * change { and } from special chars to reserved words
59 * builtins: return, trap, ulimit
60 * test magic exec with redirection only
61 * follow IFS rules more precisely, including update semantics
62 * figure out what to do with backslash-newline
63 * propagate syntax errors, die on resource errors?
64 * continuation lines, both explicit and implicit - done?
65 * maybe change charmap[] to use 2-bit entries
67 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
70 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
71 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
72 //#include "applet_tables.h" doesn't work
74 /* #include <dmalloc.h> */
79 #define HUSH_VER_STR "0.92"
81 #if defined SINGLE_APPLET_MAIN
82 /* STANDALONE does not make sense, and won't compile */
83 #undef CONFIG_FEATURE_SH_STANDALONE
84 #undef ENABLE_FEATURE_SH_STANDALONE
85 #undef USE_FEATURE_SH_STANDALONE
86 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
87 #define ENABLE_FEATURE_SH_STANDALONE 0
88 #define USE_FEATURE_SH_STANDALONE(...)
89 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
92 #if !BB_MMU && ENABLE_HUSH_TICK
93 //#undef ENABLE_HUSH_TICK
94 //#define ENABLE_HUSH_TICK 0
95 #warning On NOMMU, hush command substitution is dangerous.
96 #warning Dont use it for commands which produce lots of output.
97 #warning For more info see shell/hush.c, generate_stream_from_list().
100 #if !ENABLE_HUSH_INTERACTIVE
101 #undef ENABLE_FEATURE_EDITING
102 #define ENABLE_FEATURE_EDITING 0
103 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
104 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
107 /* Do we support ANY keywords? */
108 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
109 #define HAS_KEYWORDS 1
110 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
111 #define IF_HAS_NO_KEYWORDS(...)
113 #define HAS_KEYWORDS 0
114 #define IF_HAS_KEYWORDS(...)
115 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
118 /* Keep unconditionally on for now */
121 #define ENABLE_HUSH_FUNCTIONS 0
124 /* If you comment out one of these below, it will be #defined later
125 * to perform debug printfs to stderr: */
126 #define debug_printf(...) do {} while (0)
127 /* Finer-grained debug switches */
128 #define debug_printf_parse(...) do {} while (0)
129 #define debug_print_tree(a, b) do {} while (0)
130 #define debug_printf_exec(...) do {} while (0)
131 #define debug_printf_env(...) do {} while (0)
132 #define debug_printf_jobs(...) do {} while (0)
133 #define debug_printf_expand(...) do {} while (0)
134 #define debug_printf_glob(...) do {} while (0)
135 #define debug_printf_list(...) do {} while (0)
136 #define debug_printf_subst(...) do {} while (0)
137 #define debug_printf_clean(...) do {} while (0)
140 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
143 #ifndef debug_printf_parse
144 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
147 #ifndef debug_printf_exec
148 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
151 #ifndef debug_printf_env
152 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
155 #ifndef debug_printf_jobs
156 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
162 #ifndef debug_printf_expand
163 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
164 #define DEBUG_EXPAND 1
166 #define DEBUG_EXPAND 0
169 #ifndef debug_printf_glob
170 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
176 #ifndef debug_printf_list
177 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
180 #ifndef debug_printf_subst
181 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
184 #ifndef debug_printf_clean
185 /* broken, of course, but OK for testing */
186 static const char *indenter(int i)
188 static const char blanks[] ALIGN1 =
190 return &blanks[sizeof(blanks) - i - 1];
192 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
193 #define DEBUG_CLEAN 1
197 static void debug_print_strings(const char *prefix, char **vv)
199 fprintf(stderr, "%s:\n", prefix);
201 fprintf(stderr, " '%s'\n", *vv++);
204 #define debug_print_strings(prefix, vv) ((void)0)
208 * Leak hunting. Use hush_leaktool.sh for post-processing.
210 #ifdef FOR_HUSH_LEAKTOOL
211 /* suppress "warning: no previous prototype..." */
212 void *xxmalloc(int lineno, size_t size);
213 void *xxrealloc(int lineno, void *ptr, size_t size);
214 char *xxstrdup(int lineno, const char *str);
215 void xxfree(void *ptr);
216 void *xxmalloc(int lineno, size_t size)
218 void *ptr = xmalloc((size + 0xff) & ~0xff);
219 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
222 void *xxrealloc(int lineno, void *ptr, size_t size)
224 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
225 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
228 char *xxstrdup(int lineno, const char *str)
230 char *ptr = xstrdup(str);
231 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
234 void xxfree(void *ptr)
236 fprintf(stderr, "free %p\n", ptr);
239 #define xmalloc(s) xxmalloc(__LINE__, s)
240 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
241 #define xstrdup(s) xxstrdup(__LINE__, s)
242 #define free(p) xxfree(p)
246 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
248 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
250 #define SPECIAL_VAR_SYMBOL 3
251 #define PARSEFLAG_EXIT_FROM_LOOP 1
253 typedef enum redir_type {
255 REDIRECT_OVERWRITE = 2,
261 /* The descrip member of this structure is only used to make
262 * debugging output pretty */
263 static const struct {
265 signed char default_fd;
269 { O_RDONLY, 0, "<" },
270 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
271 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
272 { O_RDONLY, -1, "<<" },
276 typedef enum pipe_style {
283 typedef enum reserved_style {
292 #if ENABLE_HUSH_LOOPS
299 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
304 /* two pseudo-keywords support contrived "case" syntax: */
305 RES_MATCH , /* "word)" */
306 RES_CASEI , /* "this command is inside CASE" */
313 struct redir_struct {
314 struct redir_struct *next;
315 char *rd_filename; /* filename */
316 int fd; /* file descriptor being redirected */
317 int dup; /* -1, or file descriptor being duplicated */
318 smallint /*enum redir_type*/ rd_type;
322 pid_t pid; /* 0 if exited */
323 int assignment_cnt; /* how many argv[i] are assignments? */
324 smallint is_stopped; /* is the command currently running? */
325 smallint grp_type; /* GRP_xxx */
326 struct pipe *group; /* if non-NULL, this "prog" is {} group,
327 * subshell, or a compound statement */
328 char **argv; /* command name and arguments */
329 struct redir_struct *redirects; /* I/O redirections */
331 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
332 * and on execution these are substituted with their values.
333 * Substitution can make _several_ words out of one argv[n]!
334 * Example: argv[0]=='.^C*^C.' here: echo .$*.
335 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
338 #define GRP_SUBSHELL 1
339 #if ENABLE_HUSH_FUNCTIONS
340 #define GRP_FUNCTION 2
345 int num_cmds; /* total number of commands in job */
346 int alive_cmds; /* number of commands running (not exited) */
347 int stopped_cmds; /* number of commands alive, but stopped */
349 int jobid; /* job number */
350 pid_t pgrp; /* process group ID for the job */
351 char *cmdtext; /* name of job */
353 struct command *cmds; /* array of commands in pipe */
354 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
355 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
356 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
359 /* This holds pointers to the various results of parsing */
360 struct parse_context {
361 struct command *command;
362 struct pipe *list_head;
364 struct redir_struct *pending_redirect;
367 smallint ctx_inverted; /* "! cmd | cmd" */
369 smallint ctx_dsemicolon; /* ";;" seen */
371 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
372 struct parse_context *stack;
376 /* On program start, environ points to initial environment.
377 * putenv adds new pointers into it, unsetenv removes them.
378 * Neither of these (de)allocates the strings.
379 * setenv allocates new strings in malloc space and does putenv,
380 * and thus setenv is unusable (leaky) for shell's purposes */
381 #define setenv(...) setenv_is_leaky_dont_use()
383 struct variable *next;
384 char *varstr; /* points to "name=" portion */
385 int max_len; /* if > 0, name is part of initial env; else name is malloced */
386 smallint flg_export; /* putenv should be done on this var */
387 smallint flg_read_only;
390 typedef struct o_string {
392 int length; /* position where data is appended */
394 /* Misnomer! it's not "quoting", it's "protection against globbing"!
395 * (by prepending \ to *, ?, [ and to \ too) */
399 smallint has_empty_slot;
400 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
403 MAYBE_ASSIGNMENT = 0,
404 DEFINITELY_ASSIGNMENT = 1,
406 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
408 /* Used for initialization: o_string foo = NULL_O_STRING; */
409 #define NULL_O_STRING { NULL }
411 /* I can almost use ordinary FILE*. Is open_memstream() universally
412 * available? Where is it documented? */
413 typedef struct in_str {
415 /* eof_flag=1: last char in ->p is really an EOF */
416 char eof_flag; /* meaningless if ->p == NULL */
418 #if ENABLE_HUSH_INTERACTIVE
420 smallint promptmode; /* 0: PS1, 1: PS2 */
423 int (*get) (struct in_str *);
424 int (*peek) (struct in_str *);
426 #define i_getch(input) ((input)->get(input))
427 #define i_peek(input) ((input)->peek(input))
431 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
432 CHAR_IFS = 2, /* treated as ordinary if quoted */
433 CHAR_SPECIAL = 3, /* example: $ */
442 /* "Globals" within this file */
443 /* Sorted roughly by size (smaller offsets == smaller code) */
445 #if ENABLE_HUSH_INTERACTIVE
446 /* 'interactive_fd' is a fd# open to ctty, if we have one
447 * _AND_ if we decided to act interactively */
452 #if ENABLE_FEATURE_EDITING
453 line_input_t *line_input_state;
459 pid_t saved_tty_pgrp;
461 struct pipe *job_list;
462 struct pipe *toplevel_list;
463 smallint ctrl_z_flag;
465 #if ENABLE_HUSH_LOOPS
466 smallint flag_break_continue;
469 /* these three support $?, $#, and $1 */
470 smalluint last_return_code;
471 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
472 smalluint global_args_malloced;
473 /* how many non-NULL argv's we have. NB: $# + 1 */
476 #if ENABLE_HUSH_LOOPS
477 unsigned depth_break_continue;
478 unsigned depth_of_loop;
482 struct variable *top_var; /* = &G.shell_ver (set in main()) */
483 struct variable shell_ver;
484 #if ENABLE_FEATURE_SH_STANDALONE
485 struct nofork_save_area nofork_save;
488 sigjmp_buf toplevel_jb;
490 unsigned char charmap[256];
491 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
494 #define G (*ptr_to_globals)
495 /* Not #defining name to G.name - this quickly gets unwieldy
496 * (too many defines). Also, I actually prefer to see when a variable
497 * is global, thus "G." prefix is a useful hint */
498 #define INIT_G() do { \
499 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
503 /* Function prototypes for builtins */
504 static int builtin_cd(char **argv);
505 static int builtin_echo(char **argv);
506 static int builtin_eval(char **argv);
507 static int builtin_exec(char **argv);
508 static int builtin_exit(char **argv);
509 static int builtin_export(char **argv);
511 static int builtin_fg_bg(char **argv);
512 static int builtin_jobs(char **argv);
515 static int builtin_help(char **argv);
517 static int builtin_pwd(char **argv);
518 static int builtin_read(char **argv);
519 static int builtin_test(char **argv);
520 static int builtin_true(char **argv);
521 static int builtin_set(char **argv);
522 static int builtin_set_mode(const char, const char);
523 static int builtin_shift(char **argv);
524 static int builtin_source(char **argv);
525 static int builtin_umask(char **argv);
526 static int builtin_unset(char **argv);
527 #if ENABLE_HUSH_LOOPS
528 static int builtin_break(char **argv);
529 static int builtin_continue(char **argv);
531 //static int builtin_not_written(char **argv);
533 /* Table of built-in functions. They can be forked or not, depending on
534 * context: within pipes, they fork. As simple commands, they do not.
535 * When used in non-forking context, they can change global variables
536 * in the parent shell process. If forked, of course they cannot.
537 * For example, 'unset foo | whatever' will parse and run, but foo will
538 * still be set at the end. */
539 struct built_in_command {
541 int (*function)(char **argv);
544 #define BLTIN(cmd, func, help) { cmd, func, help }
546 #define BLTIN(cmd, func, help) { cmd, func }
550 /* For now, echo and test are unconditionally enabled.
551 * Maybe make it configurable? */
552 static const struct built_in_command bltins[] = {
553 BLTIN("." , builtin_source, "Run commands in a file"),
554 BLTIN(":" , builtin_true, "No-op"),
555 BLTIN("[" , builtin_test, "Test condition"),
557 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
559 #if ENABLE_HUSH_LOOPS
560 BLTIN("break" , builtin_break, "Exit from a loop"),
562 BLTIN("cd" , builtin_cd, "Change directory"),
563 #if ENABLE_HUSH_LOOPS
564 BLTIN("continue", builtin_continue, "Start new loop iteration"),
566 BLTIN("echo" , builtin_echo, "Write to stdout"),
567 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
568 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
569 BLTIN("exit" , builtin_exit, "Exit"),
570 BLTIN("export", builtin_export, "Set environment variable"),
572 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
573 BLTIN("jobs" , builtin_jobs, "List active jobs"),
575 BLTIN("pwd" , builtin_pwd, "Print current directory"),
576 BLTIN("read" , builtin_read, "Input environment variable"),
577 // BLTIN("return", builtin_not_written, "Return from a function"),
578 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
579 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
580 // BLTIN("trap" , builtin_not_written, "Trap signals"),
581 BLTIN("test" , builtin_test, "Test condition"),
582 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
583 BLTIN("umask" , builtin_umask, "Set file creation mask"),
584 BLTIN("unset" , builtin_unset, "Unset environment variable"),
586 BLTIN("help" , builtin_help, "List shell built-in commands"),
592 static void maybe_die(const char *notice, const char *msg)
594 /* Was using fancy stuff:
595 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
596 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
597 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
598 #if ENABLE_HUSH_INTERACTIVE
599 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
601 fp(msg ? "%s: %s" : notice, notice, msg);
604 #define syntax(msg) maybe_die("syntax error", msg);
606 /* Debug -- trick gcc to expand __LINE__ and convert to string */
607 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
608 #define _syntax(msg, line) __syntax(msg, line)
609 #define syntax(msg) _syntax(msg, __LINE__)
612 static int glob_needed(const char *s)
617 if (*s == '*' || *s == '[' || *s == '?')
624 static int is_assignment(const char *s)
626 if (!s || !(isalpha(*s) || *s == '_'))
629 while (isalnum(*s) || *s == '_')
634 /* Replace each \x with x in place, return ptr past NUL. */
635 static char *unbackslash(char *src)
641 if ((*dst++ = *src++) == '\0')
647 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
668 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
669 v[count1 + count2] = NULL;
672 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
676 static char **add_string_to_strings(char **strings, char *add)
681 return add_strings_to_strings(strings, v, /*dup:*/ 0);
684 static void putenv_all(char **strings)
689 debug_printf_env("putenv '%s'\n", *strings);
694 static char **putenv_all_and_save_old(char **strings)
704 eq = strchr(*strings, '=');
707 v = getenv(*strings);
710 /* v points to VAL in VAR=VAL, go back to VAR */
711 v -= (eq - *strings) + 1;
712 old = add_string_to_strings(old, v);
721 static void free_strings_and_unsetenv(char **strings, int unset)
731 debug_printf_env("unsetenv '%s'\n", *v);
739 static void free_strings(char **strings)
741 free_strings_and_unsetenv(strings, 0);
745 /* Signals are grouped, we handle them in batches */
746 static void set_misc_sighandler(void (*handler)(int))
757 static void set_fatal_sighandler(void (*handler)(int))
766 /* bash 3.2 seems to handle these just like 'fatal' ones */
772 static void set_jobctrl_sighandler(void (*handler)(int))
780 /* SIGCHLD is special and handled separately */
782 static void set_every_sighandler(void (*handler)(int))
784 set_fatal_sighandler(handler);
785 set_jobctrl_sighandler(handler);
786 set_misc_sighandler(handler);
787 signal(SIGCHLD, handler);
790 static void handler_ctrl_c(int sig UNUSED_PARAM)
792 debug_printf_jobs("got sig %d\n", sig);
793 // as usual we can have all kinds of nasty problems with leaked malloc data here
794 siglongjmp(G.toplevel_jb, 1);
797 static void handler_ctrl_z(int sig UNUSED_PARAM)
801 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
804 fputs("Sorry, backgrounding (CTRL+Z) of foreground scripts not supported on nommu\n", stderr);
809 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
812 if (!pid) { /* child */
814 die_sleep = 0; /* let nofork's xfuncs die */
816 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
817 set_every_sighandler(SIG_DFL);
818 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
819 debug_printf_jobs("returning in child\n");
820 /* return to nofork, it will eventually exit now,
821 * not return back to shell */
825 /* finish filling up pipe info */
826 G.toplevel_list->pgrp = pid; /* child is in its own pgrp */
827 G.toplevel_list->cmds[0].pid = pid;
828 /* parent needs to longjmp out of running nofork.
829 * we will "return" exitcode 0, with child put in background */
830 // as usual we can have all kinds of nasty problems with leaked malloc data here
831 debug_printf_jobs("siglongjmp in parent\n");
832 siglongjmp(G.toplevel_jb, 1);
835 /* Restores tty foreground process group, and exits.
836 * May be called as signal handler for fatal signal
837 * (will faithfully resend signal to itself, producing correct exit state)
838 * or called directly with -EXITCODE.
839 * We also call it if xfunc is exiting. */
840 static void sigexit(int sig) NORETURN;
841 static void sigexit(int sig)
843 /* Disable all signals: job control, SIGPIPE, etc. */
844 sigprocmask_allsigs(SIG_BLOCK);
846 #if ENABLE_HUSH_INTERACTIVE
847 if (G.interactive_fd)
848 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
851 /* Not a signal, just exit */
855 kill_myself_with_sig(sig); /* does not return */
858 /* Restores tty foreground process group, and exits. */
859 static void hush_exit(int exitcode) NORETURN;
860 static void hush_exit(int exitcode)
862 fflush(NULL); /* flush all streams */
863 sigexit(- (exitcode & 0xff));
868 #define set_fatal_sighandler(handler) ((void)0)
869 #define set_jobctrl_sighandler(handler) ((void)0)
870 #define hush_exit(e) exit(e)
875 static const char *set_cwd(void)
877 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
878 * we must not try to free(bb_msg_unknown) */
879 if (G.cwd == bb_msg_unknown)
881 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
883 G.cwd = bb_msg_unknown;
888 /* Get/check local shell variables */
889 static struct variable *get_local_var(const char *name)
891 struct variable *cur;
897 for (cur = G.top_var; cur; cur = cur->next) {
898 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
904 /* Basically useful version until someone wants to get fancier,
905 * see the bash man page under "Parameter Expansion" */
906 static const char *lookup_param(const char *src)
908 struct variable *var = get_local_var(src);
910 return strchr(var->varstr, '=') + 1;
914 /* str holds "NAME=VAL" and is expected to be malloced.
915 * We take ownership of it.
916 * flg_export is used by:
919 * -1: if NAME is set, leave export status alone
920 * if NAME is not set, do not export
922 static int set_local_var(char *str, int flg_export)
924 struct variable *cur;
928 value = strchr(str, '=');
929 if (!value) { /* not expected to ever happen? */
934 name_len = value - str + 1; /* including '=' */
935 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
937 if (strncmp(cur->varstr, str, name_len) != 0) {
939 /* Bail out. Note that now cur points
940 * to last var in linked list */
946 /* We found an existing var with this name */
948 if (cur->flg_read_only) {
949 bb_error_msg("%s: readonly variable", str);
953 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
954 unsetenv(str); /* just in case */
956 if (strcmp(cur->varstr, str) == 0) {
961 if (cur->max_len >= strlen(str)) {
962 /* This one is from startup env, reuse space */
963 strcpy(cur->varstr, str);
966 /* max_len == 0 signifies "malloced" var, which we can
967 * (and has to) free */
971 goto set_str_and_exp;
974 /* Not found - create next variable struct */
975 cur->next = xzalloc(sizeof(*cur));
983 if (cur->flg_export) {
984 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
985 return putenv(cur->varstr);
990 static void unset_local_var(const char *name)
992 struct variable *cur;
993 struct variable *prev = prev; /* for gcc */
998 name_len = strlen(name);
1001 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1002 if (cur->flg_read_only) {
1003 bb_error_msg("%s: readonly variable", name);
1006 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1007 * is ro, and we cannot reach this code on the 1st pass */
1008 prev->next = cur->next;
1009 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1010 bb_unsetenv(cur->varstr);
1025 static int static_get(struct in_str *i)
1028 if (ch == '\0') return EOF;
1032 static int static_peek(struct in_str *i)
1037 #if ENABLE_HUSH_INTERACTIVE
1039 static void cmdedit_set_initial_prompt(void)
1041 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1042 G.PS1 = getenv("PS1");
1049 static const char* setup_prompt_string(int promptmode)
1051 const char *prompt_str;
1052 debug_printf("setup_prompt_string %d ", promptmode);
1053 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1054 /* Set up the prompt */
1055 if (promptmode == 0) { /* PS1 */
1057 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1062 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1063 debug_printf("result '%s'\n", prompt_str);
1067 static void get_user_input(struct in_str *i)
1070 const char *prompt_str;
1072 prompt_str = setup_prompt_string(i->promptmode);
1073 #if ENABLE_FEATURE_EDITING
1074 /* Enable command line editing only while a command line
1075 * is actually being read */
1077 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1078 } while (r == 0); /* repeat if Ctrl-C */
1079 i->eof_flag = (r < 0);
1080 if (i->eof_flag) { /* EOF/error detected */
1081 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1082 G.user_input_buf[1] = '\0';
1085 fputs(prompt_str, stdout);
1087 G.user_input_buf[0] = r = fgetc(i->file);
1088 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1089 i->eof_flag = (r == EOF);
1091 i->p = G.user_input_buf;
1094 #endif /* INTERACTIVE */
1096 /* This is the magic location that prints prompts
1097 * and gets data back from the user */
1098 static int file_get(struct in_str *i)
1102 /* If there is data waiting, eat it up */
1103 if (i->p && *i->p) {
1104 #if ENABLE_HUSH_INTERACTIVE
1108 if (i->eof_flag && !*i->p)
1111 /* need to double check i->file because we might be doing something
1112 * more complicated by now, like sourcing or substituting. */
1113 #if ENABLE_HUSH_INTERACTIVE
1114 if (G.interactive_fd && i->promptme && i->file == stdin) {
1117 } while (!*i->p); /* need non-empty line */
1118 i->promptmode = 1; /* PS2 */
1123 ch = fgetc(i->file);
1125 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1126 #if ENABLE_HUSH_INTERACTIVE
1133 /* All the callers guarantee this routine will never be
1134 * used right after a newline, so prompting is not needed.
1136 static int file_peek(struct in_str *i)
1139 if (i->p && *i->p) {
1140 if (i->eof_flag && !i->p[1])
1144 ch = fgetc(i->file);
1145 i->eof_flag = (ch == EOF);
1146 i->peek_buf[0] = ch;
1147 i->peek_buf[1] = '\0';
1149 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1153 static void setup_file_in_str(struct in_str *i, FILE *f)
1155 i->peek = file_peek;
1157 #if ENABLE_HUSH_INTERACTIVE
1159 i->promptmode = 0; /* PS1 */
1165 static void setup_string_in_str(struct in_str *i, const char *s)
1167 i->peek = static_peek;
1168 i->get = static_get;
1169 #if ENABLE_HUSH_INTERACTIVE
1171 i->promptmode = 0; /* PS1 */
1181 #define B_CHUNK (32 * sizeof(char*))
1183 static void o_reset(o_string *o)
1191 static void o_free(o_string *o)
1194 memset(o, 0, sizeof(*o));
1197 static void o_grow_by(o_string *o, int len)
1199 if (o->length + len > o->maxlen) {
1200 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1201 o->data = xrealloc(o->data, 1 + o->maxlen);
1205 static void o_addchr(o_string *o, int ch)
1207 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1209 o->data[o->length] = ch;
1211 o->data[o->length] = '\0';
1214 static void o_addstr(o_string *o, const char *str, int len)
1217 memcpy(&o->data[o->length], str, len);
1219 o->data[o->length] = '\0';
1222 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1227 && (*str != '*' && *str != '?' && *str != '[')
1235 /* My analysis of quoting semantics tells me that state information
1236 * is associated with a destination, not a source.
1238 static void o_addqchr(o_string *o, int ch)
1241 char *found = strchr("*?[\\", ch);
1246 o->data[o->length] = '\\';
1249 o->data[o->length] = ch;
1251 o->data[o->length] = '\0';
1254 static void o_addQchr(o_string *o, int ch)
1257 if (o->o_quote && strchr("*?[\\", ch)) {
1259 o->data[o->length] = '\\';
1263 o->data[o->length] = ch;
1265 o->data[o->length] = '\0';
1268 static void o_addQstr(o_string *o, const char *str, int len)
1271 o_addstr(o, str, len);
1277 int ordinary_cnt = strcspn(str, "*?[\\");
1278 if (ordinary_cnt > len) /* paranoia */
1280 o_addstr(o, str, ordinary_cnt);
1281 if (ordinary_cnt == len)
1283 str += ordinary_cnt;
1284 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1288 if (ch) { /* it is necessarily one of "*?[\\" */
1290 o->data[o->length] = '\\';
1294 o->data[o->length] = ch;
1296 o->data[o->length] = '\0';
1300 /* A special kind of o_string for $VAR and `cmd` expansion.
1301 * It contains char* list[] at the beginning, which is grown in 16 element
1302 * increments. Actual string data starts at the next multiple of 16 * (char*).
1303 * list[i] contains an INDEX (int!) into this string data.
1304 * It means that if list[] needs to grow, data needs to be moved higher up
1305 * but list[i]'s need not be modified.
1306 * NB: remembering how many list[i]'s you have there is crucial.
1307 * o_finalize_list() operation post-processes this structure - calculates
1308 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1310 #if DEBUG_EXPAND || DEBUG_GLOB
1311 static void debug_print_list(const char *prefix, o_string *o, int n)
1313 char **list = (char**)o->data;
1314 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1316 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1317 prefix, list, n, string_start, o->length, o->maxlen);
1319 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1320 o->data + (int)list[i] + string_start,
1321 o->data + (int)list[i] + string_start);
1325 const char *p = o->data + (int)list[n - 1] + string_start;
1326 fprintf(stderr, " total_sz:%ld\n", (p + strlen(p) + 1) - o->data);
1330 #define debug_print_list(prefix, o, n) ((void)0)
1333 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1334 * in list[n] so that it points past last stored byte so far.
1335 * It returns n+1. */
1336 static int o_save_ptr_helper(o_string *o, int n)
1338 char **list = (char**)o->data;
1342 if (!o->has_empty_slot) {
1343 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1344 string_len = o->length - string_start;
1345 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1346 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1347 /* list[n] points to string_start, make space for 16 more pointers */
1348 o->maxlen += 0x10 * sizeof(list[0]);
1349 o->data = xrealloc(o->data, o->maxlen + 1);
1350 list = (char**)o->data;
1351 memmove(list + n + 0x10, list + n, string_len);
1352 o->length += 0x10 * sizeof(list[0]);
1354 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1356 /* We have empty slot at list[n], reuse without growth */
1357 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1358 string_len = o->length - string_start;
1359 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1360 o->has_empty_slot = 0;
1362 list[n] = (char*)(ptrdiff_t)string_len;
1366 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1367 static int o_get_last_ptr(o_string *o, int n)
1369 char **list = (char**)o->data;
1370 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1372 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1375 /* o_glob performs globbing on last list[], saving each result
1376 * as a new list[]. */
1377 static int o_glob(o_string *o, int n)
1383 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1385 return o_save_ptr_helper(o, n);
1386 pattern = o->data + o_get_last_ptr(o, n);
1387 debug_printf_glob("glob pattern '%s'\n", pattern);
1388 if (!glob_needed(pattern)) {
1390 o->length = unbackslash(pattern) - o->data;
1391 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1392 return o_save_ptr_helper(o, n);
1395 memset(&globdata, 0, sizeof(globdata));
1396 gr = glob(pattern, 0, NULL, &globdata);
1397 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1398 if (gr == GLOB_NOSPACE)
1399 bb_error_msg_and_die("out of memory during glob");
1400 if (gr == GLOB_NOMATCH) {
1401 globfree(&globdata);
1404 if (gr != 0) { /* GLOB_ABORTED ? */
1405 //TODO: testcase for bad glob pattern behavior
1406 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1408 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1409 char **argv = globdata.gl_pathv;
1410 o->length = pattern - o->data; /* "forget" pattern */
1412 o_addstr(o, *argv, strlen(*argv) + 1);
1413 n = o_save_ptr_helper(o, n);
1419 globfree(&globdata);
1421 debug_print_list("o_glob returning", o, n);
1425 /* If o->o_glob == 1, glob the string so far remembered.
1426 * Otherwise, just finish current list[] and start new */
1427 static int o_save_ptr(o_string *o, int n)
1429 if (o->o_glob) { /* if globbing is requested */
1430 /* If o->has_empty_slot, list[n] was already globbed
1431 * (if it was requested back then when it was filled)
1432 * so don't do that again! */
1433 if (!o->has_empty_slot)
1434 return o_glob(o, n); /* o_save_ptr_helper is inside */
1436 return o_save_ptr_helper(o, n);
1439 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1440 static char **o_finalize_list(o_string *o, int n)
1445 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1447 debug_print_list("finalized", o, n);
1448 debug_printf_expand("finalized n:%d\n", n);
1449 list = (char**)o->data;
1450 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1454 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1460 /* expand_strvec_to_strvec() takes a list of strings, expands
1461 * all variable references within and returns a pointer to
1462 * a list of expanded strings, possibly with larger number
1463 * of strings. (Think VAR="a b"; echo $VAR).
1464 * This new list is allocated as a single malloc block.
1465 * NULL-terminated list of char* pointers is at the beginning of it,
1466 * followed by strings themself.
1467 * Caller can deallocate entire list by single free(list). */
1469 /* Store given string, finalizing the word and starting new one whenever
1470 * we encounter IFS char(s). This is used for expanding variable values.
1471 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1472 static int expand_on_ifs(o_string *output, int n, const char *str)
1475 int word_len = strcspn(str, G.ifs);
1477 if (output->o_quote || !output->o_glob)
1478 o_addQstr(output, str, word_len);
1479 else /* protect backslashes against globbing up :) */
1480 o_addstr_duplicate_backslash(output, str, word_len);
1483 if (!*str) /* EOL - do not finalize word */
1485 o_addchr(output, '\0');
1486 debug_print_list("expand_on_ifs", output, n);
1487 n = o_save_ptr(output, n);
1488 str += strspn(str, G.ifs); /* skip ifs chars */
1490 debug_print_list("expand_on_ifs[1]", output, n);
1494 #if ENABLE_HUSH_TICK
1495 static int process_command_subs(o_string *dest,
1496 struct in_str *input, const char *subst_end);
1499 /* Expand all variable references in given string, adding words to list[]
1500 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1501 * to be filled). This routine is extremely tricky: has to deal with
1502 * variables/parameters with whitespace, $* and $@, and constructs like
1503 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1504 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1506 /* or_mask is either 0 (normal case) or 0x80
1507 * (expansion of right-hand side of assignment == 1-element expand.
1508 * It will also do no globbing, and thus we must not backslash-quote!) */
1510 char first_ch, ored_ch;
1517 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1518 debug_print_list("expand_vars_to_list", output, n);
1519 n = o_save_ptr(output, n);
1520 debug_print_list("expand_vars_to_list[0]", output, n);
1522 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1523 #if ENABLE_HUSH_TICK
1524 o_string subst_result = NULL_O_STRING;
1526 o_addstr(output, arg, p - arg);
1527 debug_print_list("expand_vars_to_list[1]", output, n);
1529 p = strchr(p, SPECIAL_VAR_SYMBOL);
1531 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1532 /* "$@" is special. Even if quoted, it can still
1533 * expand to nothing (not even an empty string) */
1534 if ((first_ch & 0x7f) != '@')
1535 ored_ch |= first_ch;
1537 switch (first_ch & 0x7f) {
1538 /* Highest bit in first_ch indicates that var is double-quoted */
1540 val = utoa(G.root_pid);
1542 case '!': /* bg pid */
1543 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1545 case '?': /* exitcode */
1546 val = utoa(G.last_return_code);
1548 case '#': /* argc */
1549 if (arg[1] != SPECIAL_VAR_SYMBOL)
1550 /* actually, it's a ${#var} */
1552 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1557 if (!G.global_argv[i])
1559 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1560 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1561 smallint sv = output->o_quote;
1562 /* unquoted var's contents should be globbed, so don't quote */
1563 output->o_quote = 0;
1564 while (G.global_argv[i]) {
1565 n = expand_on_ifs(output, n, G.global_argv[i]);
1566 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1567 if (G.global_argv[i++][0] && G.global_argv[i]) {
1568 /* this argv[] is not empty and not last:
1569 * put terminating NUL, start new word */
1570 o_addchr(output, '\0');
1571 debug_print_list("expand_vars_to_list[2]", output, n);
1572 n = o_save_ptr(output, n);
1573 debug_print_list("expand_vars_to_list[3]", output, n);
1576 output->o_quote = sv;
1578 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1579 * and in this case should treat it like '$*' - see 'else...' below */
1580 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1582 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1583 if (++i >= G.global_argc)
1585 o_addchr(output, '\0');
1586 debug_print_list("expand_vars_to_list[4]", output, n);
1587 n = o_save_ptr(output, n);
1589 } else { /* quoted $*: add as one word */
1591 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1592 if (!G.global_argv[++i])
1595 o_addchr(output, G.ifs[0]);
1599 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1600 /* "Empty variable", used to make "" etc to not disappear */
1604 #if ENABLE_HUSH_TICK
1605 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1606 struct in_str input;
1609 //TODO: can we just stuff it into "output" directly?
1610 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1611 setup_string_in_str(&input, arg);
1612 process_command_subs(&subst_result, &input, NULL);
1613 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1614 val = subst_result.data;
1618 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1620 bool exp_len = false, exp_null = false;
1621 char *var = arg, exp_save, exp_op, *exp_word;
1624 arg[0] = first_ch & 0x7f;
1626 /* prepare for expansions */
1627 if (var[0] == '#') {
1628 /* handle length expansion ${#var} */
1632 /* maybe handle parameter expansion */
1633 exp_off = strcspn(var, ":-=+?");
1637 exp_save = var[exp_off];
1638 exp_null = exp_save == ':';
1639 exp_word = var + exp_off;
1640 if (exp_null) ++exp_word;
1641 exp_op = *exp_word++;
1642 var[exp_off] = '\0';
1646 /* lookup the variable in question */
1647 if (isdigit(var[0])) {
1649 if (i < G.global_argc)
1650 val = G.global_argv[i];
1651 /* else val remains NULL: $N with too big N */
1653 val = lookup_param(var);
1655 /* handle any expansions */
1657 debug_printf_expand("expand: length of '%s' = ", val);
1658 val = utoa(val ? strlen(val) : 0);
1659 debug_printf_expand("%s\n", val);
1660 } else if (exp_off) {
1661 /* we need to do an expansion */
1662 int exp_test = (!val || (exp_null && !val[0]));
1664 exp_test = !exp_test;
1665 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1666 exp_null ? "true" : "false", exp_test);
1669 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1673 if (exp_op == '=') {
1674 if (isdigit(var[0]) || var[0] == '#') {
1675 maybe_die(var, "special vars cannot assign in this way");
1678 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1679 sprintf(new_var, "%s=%s", var, val);
1680 set_local_var(new_var, -1);
1684 var[exp_off] = exp_save;
1689 #if ENABLE_HUSH_TICK
1692 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1693 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
1695 /* unquoted var's contents should be globbed, so don't quote */
1696 smallint sv = output->o_quote;
1697 output->o_quote = 0;
1698 n = expand_on_ifs(output, n, val);
1700 output->o_quote = sv;
1702 } else { /* quoted $VAR, val will be appended below */
1703 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
1708 o_addQstr(output, val, strlen(val));
1710 /* Do the check to avoid writing to a const string */
1711 if (p && *p != SPECIAL_VAR_SYMBOL)
1712 *p = SPECIAL_VAR_SYMBOL;
1714 #if ENABLE_HUSH_TICK
1715 o_free(&subst_result);
1718 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1721 debug_print_list("expand_vars_to_list[a]", output, n);
1722 /* this part is literal, and it was already pre-quoted
1723 * if needed (much earlier), do not use o_addQstr here! */
1724 o_addstr(output, arg, strlen(arg) + 1);
1725 debug_print_list("expand_vars_to_list[b]", output, n);
1726 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1727 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1730 /* allow to reuse list[n] later without re-growth */
1731 output->has_empty_slot = 1;
1733 o_addchr(output, '\0');
1738 static char **expand_variables(char **argv, int or_mask)
1743 o_string output = NULL_O_STRING;
1745 if (or_mask & 0x100) {
1746 output.o_quote = 1; /* protect against globbing for "$var" */
1747 /* (unquoted $var will temporarily switch it off) */
1754 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1757 debug_print_list("expand_variables", &output, n);
1759 /* output.data (malloced in one block) gets returned in "list" */
1760 list = o_finalize_list(&output, n);
1761 debug_print_strings("expand_variables[1]", list);
1765 static char **expand_strvec_to_strvec(char **argv)
1767 return expand_variables(argv, 0x100);
1770 /* Used for expansion of right hand of assignments */
1771 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1773 static char *expand_string_to_string(const char *str)
1775 char *argv[2], **list;
1777 argv[0] = (char*)str;
1779 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1781 if (!list[0] || list[1])
1782 bb_error_msg_and_die("BUG in varexp2");
1783 /* actually, just move string 2*sizeof(char*) bytes back */
1784 overlapping_strcpy((char*)list, list[0]);
1785 debug_printf_expand("string_to_string='%s'\n", (char*)list);
1789 /* Used for "eval" builtin */
1790 static char* expand_strvec_to_string(char **argv)
1794 list = expand_variables(argv, 0x80);
1795 /* Convert all NULs to spaces */
1800 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
1801 bb_error_msg_and_die("BUG in varexp3");
1802 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
1806 overlapping_strcpy((char*)list, list[0]);
1807 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
1811 static char **expand_assignments(char **argv, int count)
1815 /* Expand assignments into one string each */
1816 for (i = 0; i < count; i++) {
1817 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
1823 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1824 * and stderr if they are redirected. */
1825 static int setup_redirects(struct command *prog, int squirrel[])
1828 struct redir_struct *redir;
1830 for (redir = prog->redirects; redir; redir = redir->next) {
1831 if (redir->dup == -1 && redir->rd_filename == NULL) {
1832 /* something went wrong in the parse. Pretend it didn't happen */
1835 if (redir->dup == -1) {
1837 mode = redir_table[redir->rd_type].mode;
1838 //TODO: check redir for names like '\\'
1839 p = expand_string_to_string(redir->rd_filename);
1840 openfd = open_or_warn(p, mode);
1843 /* this could get lost if stderr has been redirected, but
1844 bash and ash both lose it as well (though zsh doesn't!) */
1848 openfd = redir->dup;
1851 if (openfd != redir->fd) {
1852 if (squirrel && redir->fd < 3) {
1853 squirrel[redir->fd] = dup(redir->fd);
1856 //close(openfd); // close(-3) ??!
1858 dup2(openfd, redir->fd);
1859 if (redir->dup == -1)
1867 static void restore_redirects(int squirrel[])
1870 for (i = 0; i < 3; i++) {
1873 /* We simply die on error */
1880 #if !defined(DEBUG_CLEAN)
1881 #define free_pipe_list(head, indent) free_pipe_list(head)
1882 #define free_pipe(pi, indent) free_pipe(pi)
1884 static int free_pipe_list(struct pipe *head, int indent);
1886 /* return code is the exit status of the pipe */
1887 static int free_pipe(struct pipe *pi, int indent)
1890 struct command *command;
1891 struct redir_struct *r, *rnext;
1892 int a, i, ret_code = 0;
1894 if (pi->stopped_cmds > 0)
1896 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
1897 for (i = 0; i < pi->num_cmds; i++) {
1898 command = &pi->cmds[i];
1899 debug_printf_clean("%s command %d:\n", indenter(indent), i);
1900 if (command->argv) {
1901 for (a = 0, p = command->argv; *p; a++, p++) {
1902 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
1904 free_strings(command->argv);
1905 command->argv = NULL;
1906 } else if (command->group) {
1907 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
1908 ret_code = free_pipe_list(command->group, indent+3);
1909 debug_printf_clean("%s end group\n", indenter(indent));
1911 debug_printf_clean("%s (nil)\n", indenter(indent));
1913 for (r = command->redirects; r; r = rnext) {
1914 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
1916 /* guard against the case >$FOO, where foo is unset or blank */
1917 if (r->rd_filename) {
1918 debug_printf_clean(" %s\n", r->rd_filename);
1919 free(r->rd_filename);
1920 r->rd_filename = NULL;
1923 debug_printf_clean("&%d\n", r->dup);
1928 command->redirects = NULL;
1930 free(pi->cmds); /* children are an array, they get freed all at once */
1939 static int free_pipe_list(struct pipe *head, int indent)
1941 int rcode = 0; /* if list has no members */
1942 struct pipe *pi, *next;
1944 for (pi = head; pi; pi = next) {
1946 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
1948 rcode = free_pipe(pi, indent);
1949 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
1951 /*pi->next = NULL;*/
1959 typedef struct nommu_save_t {
1965 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
1966 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
1967 #define pseudo_exec(nommu_save, command, argv_expanded) \
1968 pseudo_exec(command, argv_expanded)
1971 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
1973 * XXX no exit() here. If you don't exec, use _exit instead.
1974 * The at_exit handlers apparently confuse the calling process,
1975 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1976 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
1977 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
1981 const struct built_in_command *x;
1983 /* If a variable is assigned in a forest, and nobody listens,
1984 * was it ever really set?
1986 if (!argv[assignment_cnt])
1987 _exit(EXIT_SUCCESS);
1989 new_env = expand_assignments(argv, assignment_cnt);
1991 putenv_all(new_env);
1992 free(new_env); /* optional */
1994 nommu_save->new_env = new_env;
1995 nommu_save->old_env = putenv_all_and_save_old(new_env);
1997 if (argv_expanded) {
1998 argv = argv_expanded;
2000 argv = expand_strvec_to_strvec(argv);
2002 nommu_save->argv = argv;
2007 * Check if the command matches any of the builtins.
2008 * Depending on context, this might be redundant. But it's
2009 * easier to waste a few CPU cycles than it is to figure out
2010 * if this is one of those cases.
2012 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2013 if (strcmp(argv[0], x->cmd) == 0) {
2014 debug_printf_exec("running builtin '%s'\n", argv[0]);
2015 rcode = x->function(argv);
2021 /* Check if the command matches any busybox applets */
2022 #if ENABLE_FEATURE_SH_STANDALONE
2023 if (strchr(argv[0], '/') == NULL) {
2024 int a = find_applet_by_name(argv[0]);
2026 if (APPLET_IS_NOEXEC(a)) {
2027 debug_printf_exec("running applet '%s'\n", argv[0]);
2028 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2029 run_applet_no_and_exit(a, argv);
2031 /* re-exec ourselves with the new arguments */
2032 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2033 execvp(bb_busybox_exec_path, argv);
2034 /* If they called chroot or otherwise made the binary no longer
2035 * executable, fall through */
2040 debug_printf_exec("execing '%s'\n", argv[0]);
2041 execvp(argv[0], argv);
2042 bb_perror_msg("can't exec '%s'", argv[0]);
2043 _exit(EXIT_FAILURE);
2046 static int run_list(struct pipe *pi);
2048 /* Called after [v]fork() in run_pipe()
2050 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2051 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2054 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2056 if (command->group) {
2058 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2061 debug_printf_exec("pseudo_exec: run_list\n");
2062 rcode = run_list(command->group);
2063 /* OK to leak memory by not calling free_pipe_list,
2064 * since this process is about to exit */
2069 /* Can happen. See what bash does with ">foo" by itself. */
2070 debug_printf("trying to pseudo_exec null command\n");
2071 _exit(EXIT_SUCCESS);
2075 static const char *get_cmdtext(struct pipe *pi)
2081 /* This is subtle. ->cmdtext is created only on first backgrounding.
2082 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2083 * On subsequent bg argv is trashed, but we won't use it */
2086 argv = pi->cmds[0].argv;
2087 if (!argv || !argv[0]) {
2088 pi->cmdtext = xzalloc(1);
2093 do len += strlen(*argv) + 1; while (*++argv);
2094 pi->cmdtext = p = xmalloc(len);
2095 argv = pi->cmds[0].argv;
2097 len = strlen(*argv);
2098 memcpy(p, *argv, len);
2106 static void insert_bg_job(struct pipe *pi)
2108 struct pipe *thejob;
2111 /* Linear search for the ID of the job to use */
2113 for (thejob = G.job_list; thejob; thejob = thejob->next)
2114 if (thejob->jobid >= pi->jobid)
2115 pi->jobid = thejob->jobid + 1;
2117 /* Add thejob to the list of running jobs */
2119 thejob = G.job_list = xmalloc(sizeof(*thejob));
2121 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2123 thejob->next = xmalloc(sizeof(*thejob));
2124 thejob = thejob->next;
2127 /* Physically copy the struct job */
2128 memcpy(thejob, pi, sizeof(struct pipe));
2129 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2130 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2131 for (i = 0; i < pi->num_cmds; i++) {
2132 // TODO: do we really need to have so many fields which are just dead weight
2133 // at execution stage?
2134 thejob->cmds[i].pid = pi->cmds[i].pid;
2135 /* all other fields are not used and stay zero */
2137 thejob->next = NULL;
2138 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2140 /* We don't wait for background thejobs to return -- append it
2141 to the list of backgrounded thejobs and leave it alone */
2142 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2143 G.last_bg_pid = thejob->cmds[0].pid;
2144 G.last_jobid = thejob->jobid;
2147 static void remove_bg_job(struct pipe *pi)
2149 struct pipe *prev_pipe;
2151 if (pi == G.job_list) {
2152 G.job_list = pi->next;
2154 prev_pipe = G.job_list;
2155 while (prev_pipe->next != pi)
2156 prev_pipe = prev_pipe->next;
2157 prev_pipe->next = pi->next;
2160 G.last_jobid = G.job_list->jobid;
2165 /* Remove a backgrounded job */
2166 static void delete_finished_bg_job(struct pipe *pi)
2169 pi->stopped_cmds = 0;
2175 /* Check to see if any processes have exited -- if they
2176 * have, figure out why and see if a job has completed */
2177 static int checkjobs(struct pipe* fg_pipe)
2187 attributes = WUNTRACED;
2188 if (fg_pipe == NULL)
2189 attributes |= WNOHANG;
2191 /* Do we do this right?
2192 * bash-3.00# sleep 20 | false
2194 * [3]+ Stopped sleep 20 | false
2195 * bash-3.00# echo $?
2196 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2199 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2200 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2201 // + killall -STOP cat
2204 // TODO: safe_waitpid?
2205 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
2207 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
2209 if (WIFSTOPPED(status))
2210 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2211 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2212 if (WIFSIGNALED(status))
2213 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2214 childpid, WTERMSIG(status), WEXITSTATUS(status));
2215 if (WIFEXITED(status))
2216 debug_printf_jobs("pid %d exited, exitcode %d\n",
2217 childpid, WEXITSTATUS(status));
2219 /* Were we asked to wait for fg pipe? */
2221 for (i = 0; i < fg_pipe->num_cmds; i++) {
2222 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2223 if (fg_pipe->cmds[i].pid != childpid)
2225 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2227 fg_pipe->cmds[i].pid = 0;
2228 fg_pipe->alive_cmds--;
2229 if (i == fg_pipe->num_cmds - 1) {
2230 /* last process gives overall exitstatus */
2231 rcode = WEXITSTATUS(status);
2232 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2235 fg_pipe->cmds[i].is_stopped = 1;
2236 fg_pipe->stopped_cmds++;
2238 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2239 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2240 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2241 /* All processes in fg pipe have exited/stopped */
2243 if (fg_pipe->alive_cmds)
2244 insert_bg_job(fg_pipe);
2248 /* There are still running processes in the fg pipe */
2249 goto wait_more; /* do waitpid again */
2251 /* it wasnt fg_pipe, look for process in bg pipes */
2255 /* We asked to wait for bg or orphaned children */
2256 /* No need to remember exitcode in this case */
2257 for (pi = G.job_list; pi; pi = pi->next) {
2258 for (i = 0; i < pi->num_cmds; i++) {
2259 if (pi->cmds[i].pid == childpid)
2260 goto found_pi_and_prognum;
2263 /* Happens when shell is used as init process (init=/bin/sh) */
2264 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2265 continue; /* do waitpid again */
2267 found_pi_and_prognum:
2270 pi->cmds[i].pid = 0;
2272 if (!pi->alive_cmds) {
2273 printf(JOB_STATUS_FORMAT, pi->jobid,
2274 "Done", pi->cmdtext);
2275 delete_finished_bg_job(pi);
2279 pi->cmds[i].is_stopped = 1;
2283 } /* while (waitpid succeeds)... */
2285 /* wait found no children or failed */
2287 if (childpid && errno != ECHILD)
2288 bb_perror_msg("waitpid");
2293 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2296 int rcode = checkjobs(fg_pipe);
2297 /* Job finished, move the shell to the foreground */
2298 p = getpgid(0); /* pgid of our process */
2299 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2300 tcsetpgrp(G.interactive_fd, p);
2305 /* run_pipe() starts all the jobs, but doesn't wait for anything
2306 * to finish. See checkjobs().
2308 * return code is normally -1, when the caller has to wait for children
2309 * to finish to determine the exit status of the pipe. If the pipe
2310 * is a simple builtin command, however, the action is done by the
2311 * time run_pipe returns, and the exit code is provided as the
2314 * The input of the pipe is always stdin, the output is always
2315 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2316 * because it tries to avoid running the command substitution in
2317 * subshell, when that is in fact necessary. The subshell process
2318 * now has its stdout directed to the input of the appropriate pipe,
2319 * so this routine is noticeably simpler.
2321 * Returns -1 only if started some children. IOW: we have to
2322 * mask out retvals of builtins etc with 0xff!
2324 static int run_pipe(struct pipe *pi)
2328 int pipefds[2]; /* pipefds[0] is for reading */
2329 struct command *command;
2330 char **argv_expanded;
2332 const struct built_in_command *x;
2334 /* it is not always needed, but we aim to smaller code */
2335 int squirrel[] = { -1, -1, -1 };
2337 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2339 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2345 pi->stopped_cmds = 0;
2347 /* Check if this is a simple builtin (not part of a pipe).
2348 * Builtins within pipes have to fork anyway, and are handled in
2349 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2351 command = &(pi->cmds[0]);
2353 #if ENABLE_HUSH_FUNCTIONS
2354 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2355 /* We "execute" function definition */
2356 bb_error_msg("here we ought to remember function definition, and go on");
2357 return EXIT_SUCCESS;
2361 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2362 debug_printf("non-subshell grouping\n");
2363 setup_redirects(command, squirrel);
2364 debug_printf_exec(": run_list\n");
2365 rcode = run_list(command->group) & 0xff;
2366 restore_redirects(squirrel);
2367 debug_printf_exec("run_pipe return %d\n", rcode);
2368 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2372 argv = command->argv;
2373 argv_expanded = NULL;
2375 if (single_and_fg && argv != NULL) {
2376 char **new_env = NULL;
2377 char **old_env = NULL;
2379 i = command->assignment_cnt;
2380 if (i != 0 && argv[i] == NULL) {
2381 /* assignments, but no command: set local environment */
2382 for (i = 0; argv[i] != NULL; i++) {
2383 debug_printf("local environment set: %s\n", argv[i]);
2384 p = expand_string_to_string(argv[i]);
2385 set_local_var(p, 0);
2387 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2390 /* Expand the rest into (possibly) many strings each */
2391 argv_expanded = expand_strvec_to_strvec(argv + i);
2393 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2394 if (strcmp(argv_expanded[0], x->cmd) != 0)
2396 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2397 debug_printf("exec with redirects only\n");
2398 setup_redirects(command, NULL);
2399 rcode = EXIT_SUCCESS;
2400 goto clean_up_and_ret1;
2402 debug_printf("builtin inline %s\n", argv_expanded[0]);
2403 /* XXX setup_redirects acts on file descriptors, not FILEs.
2404 * This is perfect for work that comes after exec().
2405 * Is it really safe for inline use? Experimentally,
2406 * things seem to work with glibc. */
2407 setup_redirects(command, squirrel);
2408 new_env = expand_assignments(argv, command->assignment_cnt);
2409 old_env = putenv_all_and_save_old(new_env);
2410 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2411 rcode = x->function(argv_expanded) & 0xff;
2412 #if ENABLE_FEATURE_SH_STANDALONE
2415 restore_redirects(squirrel);
2416 free_strings_and_unsetenv(new_env, 1);
2417 putenv_all(old_env);
2418 free(old_env); /* not free_strings()! */
2420 free(argv_expanded);
2421 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2422 debug_printf_exec("run_pipe return %d\n", rcode);
2425 #if ENABLE_FEATURE_SH_STANDALONE
2426 i = find_applet_by_name(argv_expanded[0]);
2427 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2428 setup_redirects(command, squirrel);
2429 save_nofork_data(&G.nofork_save);
2430 new_env = expand_assignments(argv, command->assignment_cnt);
2431 old_env = putenv_all_and_save_old(new_env);
2432 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2433 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2434 goto clean_up_and_ret;
2439 /* NB: argv_expanded may already be created, and that
2440 * might include `cmd` runs! Do not rerun it! We *must*
2441 * use argv_expanded if it's non-NULL */
2443 /* Disable job control signals for shell (parent) and
2444 * for initial child code after fork */
2445 set_jobctrl_sighandler(SIG_IGN);
2447 /* Going to fork a child per each pipe member */
2451 for (i = 0; i < pi->num_cmds; i++) {
2453 volatile nommu_save_t nommu_save;
2454 nommu_save.new_env = NULL;
2455 nommu_save.old_env = NULL;
2456 nommu_save.argv = NULL;
2458 command = &(pi->cmds[i]);
2459 if (command->argv) {
2460 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2462 debug_printf_exec(": pipe member with no argv\n");
2464 /* pipes are inserted between pairs of commands */
2467 if ((i + 1) < pi->num_cmds)
2470 command->pid = BB_MMU ? fork() : vfork();
2471 if (!command->pid) { /* child */
2472 if (ENABLE_HUSH_JOB)
2473 die_sleep = 0; /* let nofork's xfuncs die */
2475 /* Every child adds itself to new process group
2476 * with pgid == pid_of_first_child_in_pipe */
2477 if (G.run_list_level == 1 && G.interactive_fd) {
2479 /* Don't do pgrp restore anymore on fatal signals */
2480 set_fatal_sighandler(SIG_DFL);
2482 if (pgrp < 0) /* true for 1st process only */
2484 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2485 /* We do it in *every* child, not just first,
2487 tcsetpgrp(G.interactive_fd, pgrp);
2491 xmove_fd(nextin, 0);
2492 xmove_fd(pipefds[1], 1); /* write end */
2494 close(pipefds[0]); /* read end */
2495 /* Like bash, explicit redirects override pipes,
2496 * and the pipe fd is available for dup'ing. */
2497 setup_redirects(command, NULL);
2499 /* Restore default handlers just prior to exec */
2500 set_jobctrl_sighandler(SIG_DFL);
2501 set_misc_sighandler(SIG_DFL);
2502 signal(SIGCHLD, SIG_DFL);
2503 /* Stores to nommu_save list of env vars putenv'ed
2504 * (NOMMU, on MMU we don't need that) */
2505 /* cast away volatility... */
2506 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2507 /* pseudo_exec() does not return */
2511 /* Clean up after vforked child */
2512 free(nommu_save.argv);
2513 free_strings_and_unsetenv(nommu_save.new_env, 1);
2514 putenv_all(nommu_save.old_env);
2516 free(argv_expanded);
2517 argv_expanded = NULL;
2518 if (command->pid < 0) { /* [v]fork failed */
2519 /* Clearly indicate, was it fork or vfork */
2520 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2524 /* Second and next children need to know pid of first one */
2526 pi->pgrp = command->pid;
2532 if ((i + 1) < pi->num_cmds)
2533 close(pipefds[1]); /* write end */
2534 /* Pass read (output) pipe end to next iteration */
2535 nextin = pipefds[0];
2538 if (!pi->alive_cmds) {
2539 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2543 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2547 #ifndef debug_print_tree
2548 static void debug_print_tree(struct pipe *pi, int lvl)
2550 static const char *const PIPE[] = {
2556 static const char *RES[] = {
2557 [RES_NONE ] = "NONE" ,
2560 [RES_THEN ] = "THEN" ,
2561 [RES_ELIF ] = "ELIF" ,
2562 [RES_ELSE ] = "ELSE" ,
2565 #if ENABLE_HUSH_LOOPS
2566 [RES_FOR ] = "FOR" ,
2567 [RES_WHILE] = "WHILE",
2568 [RES_UNTIL] = "UNTIL",
2570 [RES_DONE ] = "DONE" ,
2572 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2575 #if ENABLE_HUSH_CASE
2576 [RES_CASE ] = "CASE" ,
2577 [RES_MATCH] = "MATCH",
2578 [RES_CASEI] = "CASEI",
2579 [RES_ESAC ] = "ESAC" ,
2581 [RES_XXXX ] = "XXXX" ,
2582 [RES_SNTX ] = "SNTX" ,
2584 static const char *const GRPTYPE[] = {
2587 #if ENABLE_HUSH_FUNCTIONS
2596 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2597 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2599 while (prn < pi->num_cmds) {
2600 struct command *command = &pi->cmds[prn];
2601 char **argv = command->argv;
2603 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2604 if (command->group) {
2605 fprintf(stderr, " group %s: (argv=%p)\n",
2606 GRPTYPE[command->grp_type],
2608 debug_print_tree(command->group, lvl+1);
2612 if (argv) while (*argv) {
2613 fprintf(stderr, " '%s'", *argv);
2616 fprintf(stderr, "\n");
2625 /* NB: called by pseudo_exec, and therefore must not modify any
2626 * global data until exec/_exit (we can be a child after vfork!) */
2627 static int run_list(struct pipe *pi)
2629 #if ENABLE_HUSH_CASE
2630 char *case_word = NULL;
2632 #if ENABLE_HUSH_LOOPS
2633 struct pipe *loop_top = NULL;
2634 char *for_varname = NULL;
2635 char **for_lcur = NULL;
2636 char **for_list = NULL;
2638 smallint flag_skip = 1;
2639 smalluint rcode = 0; /* probably just for compiler */
2640 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2641 smalluint cond_code = 0;
2643 enum { cond_code = 0, };
2645 /*enum reserved_style*/ smallint rword = RES_NONE;
2646 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2648 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2650 #if ENABLE_HUSH_LOOPS
2651 /* Check syntax for "for" */
2652 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2653 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2655 /* current word is FOR or IN (BOLD in comments below) */
2656 if (cpipe->next == NULL) {
2657 syntax("malformed for");
2658 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2661 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2662 if (cpipe->next->res_word == RES_DO)
2664 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2665 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2666 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2668 syntax("malformed for");
2669 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2675 /* Past this point, all code paths should jump to ret: label
2676 * in order to return, no direct "return" statements please.
2677 * This helps to ensure that no memory is leaked. */
2680 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2681 * We are saving state before entering outermost list ("while...done")
2682 * so that ctrl-Z will correctly background _entire_ outermost list,
2683 * not just a part of it (like "sleep 1 | exit 2") */
2684 if (++G.run_list_level == 1 && G.interactive_fd) {
2685 if (sigsetjmp(G.toplevel_jb, 1)) {
2686 /* ctrl-Z forked and we are parent; or ctrl-C.
2687 * Sighandler has longjmped us here */
2688 signal(SIGINT, SIG_IGN);
2689 signal(SIGTSTP, SIG_IGN);
2690 /* Restore level (we can be coming from deep inside
2692 G.run_list_level = 1;
2693 #if ENABLE_FEATURE_SH_STANDALONE
2694 if (G.nofork_save.saved) { /* if save area is valid */
2695 debug_printf_jobs("exiting nofork early\n");
2696 restore_nofork_data(&G.nofork_save);
2699 if (G.ctrl_z_flag) {
2700 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2701 * Remember this child as background job */
2704 /* ctrl-C. We just stop doing whatever we were doing */
2707 USE_HUSH_LOOPS(loop_top = NULL;)
2708 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2712 /* ctrl-Z handler will store pid etc in pi */
2713 G.toplevel_list = pi;
2715 #if ENABLE_FEATURE_SH_STANDALONE
2716 G.nofork_save.saved = 0; /* in case we will run a nofork later */
2718 signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2719 signal(SIGINT, handler_ctrl_c);
2723 /* Go through list of pipes, (maybe) executing them. */
2724 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2725 IF_HAS_KEYWORDS(rword = pi->res_word;)
2726 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2727 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2728 rword, cond_code, skip_more_for_this_rword);
2729 #if ENABLE_HUSH_LOOPS
2730 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2731 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2733 /* start of a loop: remember where loop starts */
2738 if (rword == skip_more_for_this_rword && flag_skip) {
2739 if (pi->followup == PIPE_SEQ)
2741 /* it is "<false> && CMD" or "<true> || CMD"
2742 * and we should not execute CMD */
2746 skip_more_for_this_rword = RES_XXXX;
2749 if (rword == RES_THEN) {
2750 /* "if <false> THEN cmd": skip cmd */
2754 if (rword == RES_ELSE || rword == RES_ELIF) {
2755 /* "if <true> then ... ELSE/ELIF cmd":
2756 * skip cmd and all following ones */
2761 #if ENABLE_HUSH_LOOPS
2762 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
2764 /* first loop through for */
2766 static const char encoded_dollar_at[] ALIGN1 = {
2767 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
2768 }; /* encoded representation of "$@" */
2769 static const char *const encoded_dollar_at_argv[] = {
2770 encoded_dollar_at, NULL
2771 }; /* argv list with one element: "$@" */
2774 vals = (char**)encoded_dollar_at_argv;
2775 if (pi->next->res_word == RES_IN) {
2776 /* if no variable values after "in" we skip "for" */
2777 if (!pi->next->cmds[0].argv)
2779 vals = pi->next->cmds[0].argv;
2780 } /* else: "for var; do..." -> assume "$@" list */
2781 /* create list of variable values */
2782 debug_print_strings("for_list made from", vals);
2783 for_list = expand_strvec_to_strvec(vals);
2784 for_lcur = for_list;
2785 debug_print_strings("for_list", for_list);
2786 for_varname = pi->cmds[0].argv[0];
2787 pi->cmds[0].argv[0] = NULL;
2789 free(pi->cmds[0].argv[0]);
2791 /* "for" loop is over, clean up */
2795 pi->cmds[0].argv[0] = for_varname;
2798 /* insert next value from for_lcur */
2799 //TODO: does it need escaping?
2800 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2801 pi->cmds[0].assignment_cnt = 1;
2803 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
2805 if (rword == RES_DONE) {
2806 continue; /* "done" has no cmds too */
2809 #if ENABLE_HUSH_CASE
2810 if (rword == RES_CASE) {
2811 case_word = expand_strvec_to_string(pi->cmds->argv);
2814 if (rword == RES_MATCH) {
2817 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
2819 /* all prev words didn't match, does this one match? */
2820 argv = pi->cmds->argv;
2822 char *pattern = expand_string_to_string(*argv);
2823 /* TODO: which FNM_xxx flags to use? */
2824 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
2826 if (cond_code == 0) { /* match! we will execute this branch */
2827 free(case_word); /* make future "word)" stop */
2835 if (rword == RES_CASEI) { /* inside of a case branch */
2837 continue; /* not matched yet, skip this pipe */
2840 if (pi->num_cmds == 0)
2843 /* After analyzing all keywords and conditions, we decided
2844 * to execute this pipe. NB: has to do checkjobs(NULL)
2845 * after run_pipe() to collect any background children,
2846 * even if list execution is to be stopped. */
2847 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
2850 #if ENABLE_HUSH_LOOPS
2851 G.flag_break_continue = 0;
2853 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
2855 /* we only ran a builtin: rcode is already known
2856 * and we don't need to wait for anything. */
2857 #if ENABLE_HUSH_LOOPS
2858 /* was it "break" or "continue"? */
2859 if (G.flag_break_continue) {
2860 smallint fbc = G.flag_break_continue;
2861 /* we might fall into outer *loop*,
2862 * don't want to break it too */
2864 G.depth_break_continue--;
2865 if (G.depth_break_continue == 0)
2866 G.flag_break_continue = 0;
2867 /* else: e.g. "continue 2" should *break* once, *then* continue */
2868 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
2869 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
2870 goto check_jobs_and_break;
2871 /* "continue": simulate end of loop */
2876 } else if (pi->followup == PIPE_BG) {
2877 /* what does bash do with attempts to background builtins? */
2878 /* even bash 3.2 doesn't do that well with nested bg:
2879 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2880 * I'm NOT treating inner &'s as jobs */
2882 if (G.run_list_level == 1)
2885 rcode = 0; /* EXIT_SUCCESS */
2888 if (G.run_list_level == 1 && G.interactive_fd) {
2889 /* waits for completion, then fg's main shell */
2890 rcode = checkjobs_and_fg_shell(pi);
2891 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
2894 { /* this one just waits for completion */
2895 rcode = checkjobs(pi);
2896 debug_printf_exec(": checkjobs returned %d\n", rcode);
2900 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2901 G.last_return_code = rcode;
2903 /* Analyze how result affects subsequent commands */
2905 if (rword == RES_IF || rword == RES_ELIF)
2908 #if ENABLE_HUSH_LOOPS
2909 if (rword == RES_WHILE) {
2911 rcode = 0; /* "while false; do...done" - exitcode 0 */
2912 goto check_jobs_and_break;
2915 if (rword == RES_UNTIL) {
2917 check_jobs_and_break:
2923 if ((rcode == 0 && pi->followup == PIPE_OR)
2924 || (rcode != 0 && pi->followup == PIPE_AND)
2926 skip_more_for_this_rword = rword;
2932 if (G.ctrl_z_flag) {
2933 /* ctrl-Z forked somewhere in the past, we are the child,
2934 * and now we completed running the list. Exit. */
2939 if (!--G.run_list_level && G.interactive_fd) {
2940 signal(SIGTSTP, SIG_IGN);
2941 signal(SIGINT, SIG_IGN);
2944 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
2945 #if ENABLE_HUSH_LOOPS
2950 #if ENABLE_HUSH_CASE
2956 /* Select which version we will use */
2957 static int run_and_free_list(struct pipe *pi)
2960 debug_printf_exec("run_and_free_list entered\n");
2962 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
2963 rcode = run_list(pi);
2965 /* free_pipe_list has the side effect of clearing memory.
2966 * In the long run that function can be merged with run_list,
2967 * but doing that now would hobble the debugging effort. */
2968 free_pipe_list(pi, /* indent: */ 0);
2969 debug_printf_exec("run_and_free_list return %d\n", rcode);
2974 /* Peek ahead in the in_str to find out if we have a "&n" construct,
2975 * as in "2>&1", that represents duplicating a file descriptor.
2976 * Return either -2 (syntax error), -1 (no &), or the number found.
2978 static int redirect_dup_num(struct in_str *input)
2980 int ch, d = 0, ok = 0;
2982 if (ch != '&') return -1;
2984 i_getch(input); /* get the & */
2988 return -3; /* "-" represents "close me" */
2990 while (isdigit(ch)) {
2991 d = d*10 + (ch-'0');
2998 bb_error_msg("ambiguous redirect");
3002 /* The src parameter allows us to peek forward to a possible &n syntax
3003 * for file descriptor duplication, e.g., "2>&1".
3004 * Return code is 0 normally, 1 if a syntax error is detected in src.
3005 * Resource errors (in xmalloc) cause the process to exit */
3006 static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
3007 struct in_str *input)
3009 struct command *command = ctx->command;
3010 struct redir_struct *redir = command->redirects;
3011 struct redir_struct *last_redir = NULL;
3013 /* Create a new redir_struct and drop it onto the end of the linked list */
3016 redir = redir->next;
3018 redir = xzalloc(sizeof(struct redir_struct));
3019 /* redir->next = NULL; */
3020 /* redir->rd_filename = NULL; */
3022 last_redir->next = redir;
3024 command->redirects = redir;
3027 redir->rd_type = style;
3028 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3030 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3032 /* Check for a '2>&1' type redirect */
3033 redir->dup = redirect_dup_num(input);
3034 if (redir->dup == -2)
3035 return 1; /* syntax error */
3036 if (redir->dup != -1) {
3037 /* Erik had a check here that the file descriptor in question
3038 * is legit; I postpone that to "run time"
3039 * A "-" representation of "close me" shows up as a -3 here */
3040 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3042 /* We do _not_ try to open the file that src points to,
3043 * since we need to return and let src be expanded first.
3044 * Set ctx->pending_redirect, so we know what to do at the
3045 * end of the next parsed word. */
3046 ctx->pending_redirect = redir;
3052 static struct pipe *new_pipe(void)
3055 pi = xzalloc(sizeof(struct pipe));
3056 /*pi->followup = 0; - deliberately invalid value */
3057 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3061 /* Command (member of a pipe) is complete. The only possible error here
3062 * is out of memory, in which case xmalloc exits. */
3063 static int done_command(struct parse_context *ctx)
3065 /* The command is really already in the pipe structure, so
3066 * advance the pipe counter and make a new, null command. */
3067 struct pipe *pi = ctx->pipe;
3068 struct command *command = ctx->command;
3071 if (command->group == NULL
3072 && command->argv == NULL
3073 && command->redirects == NULL
3075 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3076 return pi->num_cmds;
3079 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3081 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3084 /* Only real trickiness here is that the uncommitted
3085 * command structure is not counted in pi->num_cmds. */
3086 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3087 command = &pi->cmds[pi->num_cmds];
3088 memset(command, 0, sizeof(*command));
3090 ctx->command = command;
3091 /* but ctx->pipe and ctx->list_head remain unchanged */
3093 return pi->num_cmds; /* used only for 0/nonzero check */
3096 static void done_pipe(struct parse_context *ctx, pipe_style type)
3100 debug_printf_parse("done_pipe entered, followup %d\n", type);
3101 /* Close previous command */
3102 not_null = done_command(ctx);
3103 ctx->pipe->followup = type;
3104 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3105 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3106 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3108 /* Without this check, even just <enter> on command line generates
3109 * tree of three NOPs (!). Which is harmless but annoying.
3110 * IOW: it is safe to do it unconditionally.
3111 * RES_NONE case is for "for a in; do ..." (empty IN set)
3112 * to work, possibly other cases too. */
3113 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3115 debug_printf_parse("done_pipe: adding new pipe: "
3116 "not_null:%d ctx->ctx_res_w:%d\n",
3117 not_null, ctx->ctx_res_w);
3119 ctx->pipe->next = new_p;
3121 ctx->command = NULL; /* needed! */
3122 /* RES_THEN, RES_DO etc are "sticky" -
3123 * they remain set for commands inside if/while.
3124 * This is used to control execution.
3125 * RES_FOR and RES_IN are NOT sticky (needed to support
3126 * cases where variable or value happens to match a keyword):
3128 #if ENABLE_HUSH_LOOPS
3129 if (ctx->ctx_res_w == RES_FOR
3130 || ctx->ctx_res_w == RES_IN)
3131 ctx->ctx_res_w = RES_NONE;
3133 #if ENABLE_HUSH_CASE
3134 if (ctx->ctx_res_w == RES_MATCH)
3135 ctx->ctx_res_w = RES_CASEI;
3137 /* Create the memory for command, roughly:
3138 * ctx->pipe->cmds = new struct command;
3139 * ctx->command = &ctx->pipe->cmds[0];
3143 debug_printf_parse("done_pipe return\n");
3146 static void initialize_context(struct parse_context *ctx)
3148 memset(ctx, 0, sizeof(*ctx));
3149 ctx->pipe = ctx->list_head = new_pipe();
3150 /* Create the memory for command, roughly:
3151 * ctx->pipe->cmds = new struct command;
3152 * ctx->command = &ctx->pipe->cmds[0];
3158 /* If a reserved word is found and processed, parse context is modified
3159 * and 1 is returned.
3160 * Handles if, then, elif, else, fi, for, while, until, do, done.
3161 * case, function, and select are obnoxious, save those for later.
3164 struct reserved_combo {
3167 unsigned char assignment_flag;
3171 FLAG_END = (1 << RES_NONE ),
3173 FLAG_IF = (1 << RES_IF ),
3174 FLAG_THEN = (1 << RES_THEN ),
3175 FLAG_ELIF = (1 << RES_ELIF ),
3176 FLAG_ELSE = (1 << RES_ELSE ),
3177 FLAG_FI = (1 << RES_FI ),
3179 #if ENABLE_HUSH_LOOPS
3180 FLAG_FOR = (1 << RES_FOR ),
3181 FLAG_WHILE = (1 << RES_WHILE),
3182 FLAG_UNTIL = (1 << RES_UNTIL),
3183 FLAG_DO = (1 << RES_DO ),
3184 FLAG_DONE = (1 << RES_DONE ),
3185 FLAG_IN = (1 << RES_IN ),
3187 #if ENABLE_HUSH_CASE
3188 FLAG_MATCH = (1 << RES_MATCH),
3189 FLAG_ESAC = (1 << RES_ESAC ),
3191 FLAG_START = (1 << RES_XXXX ),
3194 static const struct reserved_combo* match_reserved_word(o_string *word)
3196 /* Mostly a list of accepted follow-up reserved words.
3197 * FLAG_END means we are done with the sequence, and are ready
3198 * to turn the compound list into a command.
3199 * FLAG_START means the word must start a new compound list.
3201 static const struct reserved_combo reserved_list[] = {
3203 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3204 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3205 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3206 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3207 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3208 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3210 #if ENABLE_HUSH_LOOPS
3211 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3212 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3213 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3214 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3215 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3216 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3218 #if ENABLE_HUSH_CASE
3219 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3220 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3223 const struct reserved_combo *r;
3225 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3226 if (strcmp(word->data, r->literal) == 0)
3231 static int reserved_word(o_string *word, struct parse_context *ctx)
3233 #if ENABLE_HUSH_CASE
3234 static const struct reserved_combo reserved_match = {
3235 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3238 const struct reserved_combo *r;
3240 r = match_reserved_word(word);
3244 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3245 #if ENABLE_HUSH_CASE
3246 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3247 /* "case word IN ..." - IN part starts first match part */
3248 r = &reserved_match;
3251 if (r->flag == 0) { /* '!' */
3252 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3254 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3256 ctx->ctx_inverted = 1;
3259 if (r->flag & FLAG_START) {
3260 struct parse_context *new;
3261 debug_printf("push stack\n");
3262 new = xmalloc(sizeof(*new));
3263 *new = *ctx; /* physical copy */
3264 initialize_context(ctx);
3266 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3268 ctx->ctx_res_w = RES_SNTX;
3271 ctx->ctx_res_w = r->res;
3272 ctx->old_flag = r->flag;
3273 if (ctx->old_flag & FLAG_END) {
3274 struct parse_context *old;
3275 debug_printf("pop stack\n");
3276 done_pipe(ctx, PIPE_SEQ);
3278 old->command->group = ctx->list_head;
3279 old->command->grp_type = GRP_NORMAL;
3280 *ctx = *old; /* physical copy */
3283 word->o_assignment = r->assignment_flag;
3288 //TODO: many, many callers don't check error from done_word()
3290 /* Word is complete, look at it and update parsing context.
3291 * Normal return is 0. Syntax errors return 1. */
3292 static int done_word(o_string *word, struct parse_context *ctx)
3294 struct command *command = ctx->command;
3296 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3297 if (word->length == 0 && word->nonnull == 0) {
3298 debug_printf_parse("done_word return 0: true null, ignored\n");
3301 /* If this word wasn't an assignment, next ones definitely
3302 * can't be assignments. Even if they look like ones. */
3303 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3304 && word->o_assignment != WORD_IS_KEYWORD
3306 word->o_assignment = NOT_ASSIGNMENT;
3308 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3309 command->assignment_cnt++;
3310 word->o_assignment = MAYBE_ASSIGNMENT;
3313 if (ctx->pending_redirect) {
3314 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3315 * only if run as "bash", not "sh" */
3316 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3317 word->o_assignment = NOT_ASSIGNMENT;
3318 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3320 /* "{ echo foo; } echo bar" - bad */
3321 /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
3322 if (command->group) {
3324 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3328 #if ENABLE_HUSH_CASE
3329 if (ctx->ctx_dsemicolon
3330 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3332 /* already done when ctx_dsemicolon was set to 1: */
3333 /* ctx->ctx_res_w = RES_MATCH; */
3334 ctx->ctx_dsemicolon = 0;
3338 if (!command->argv /* if it's the first word... */
3339 #if ENABLE_HUSH_LOOPS
3340 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3341 && ctx->ctx_res_w != RES_IN
3344 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3345 if (reserved_word(word, ctx)) {
3347 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3348 return (ctx->ctx_res_w == RES_SNTX);
3352 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3353 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3354 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3355 /* (otherwise it's known to be not empty and is already safe) */
3357 /* exclude "$@" - it can expand to no word despite "" */
3358 char *p = word->data;
3359 while (p[0] == SPECIAL_VAR_SYMBOL
3360 && (p[1] & 0x7f) == '@'
3361 && p[2] == SPECIAL_VAR_SYMBOL
3365 if (p == word->data || p[0] != '\0') {
3366 /* saw no "$@", or not only "$@" but some
3367 * real text is there too */
3368 /* insert "empty variable" reference, this makes
3369 * e.g. "", $empty"" etc to not disappear */
3370 o_addchr(word, SPECIAL_VAR_SYMBOL);
3371 o_addchr(word, SPECIAL_VAR_SYMBOL);
3374 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3375 debug_print_strings("word appended to argv", command->argv);
3379 ctx->pending_redirect = NULL;
3381 #if ENABLE_HUSH_LOOPS
3382 /* Force FOR to have just one word (variable name) */
3383 /* NB: basically, this makes hush see "for v in ..." syntax as if
3384 * as it is "for v; in ...". FOR and IN become two pipe structs
3386 if (ctx->ctx_res_w == RES_FOR) {
3387 //TODO: check that command->argv[0] is a valid variable name!
3388 done_pipe(ctx, PIPE_SEQ);
3391 #if ENABLE_HUSH_CASE
3392 /* Force CASE to have just one word */
3393 if (ctx->ctx_res_w == RES_CASE) {
3394 done_pipe(ctx, PIPE_SEQ);
3397 debug_printf_parse("done_word return 0\n");
3401 /* If a redirect is immediately preceded by a number, that number is
3402 * supposed to tell which file descriptor to redirect. This routine
3403 * looks for such preceding numbers. In an ideal world this routine
3404 * needs to handle all the following classes of redirects...
3405 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3406 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3407 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3408 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3409 * A -1 output from this program means no valid number was found, so the
3410 * caller should use the appropriate default for this redirection.
3412 static int redirect_opt_num(o_string *o)
3418 for (num = 0; num < o->length; num++) {
3419 if (!isdigit(o->data[num])) {
3423 num = atoi(o->data);
3428 static int parse_stream(o_string *dest, struct parse_context *ctx,
3429 struct in_str *input0, const char *end_trigger);
3431 #if ENABLE_HUSH_TICK
3432 static FILE *generate_stream_from_list(struct pipe *head)
3435 int pid, channel[2];
3438 /* *** NOMMU WARNING *** */
3439 /* By using vfork here, we suspend parent till child exits or execs.
3440 * If child will not do it before it fills the pipe, it can block forever
3441 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3443 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3444 * huge=`cat TESTFILE` # will block here forever
3447 pid = BB_MMU ? fork() : vfork();
3449 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3450 if (pid == 0) { /* child */
3451 if (ENABLE_HUSH_JOB)
3452 die_sleep = 0; /* let nofork's xfuncs die */
3453 close(channel[0]); /* NB: close _first_, then move fd! */
3454 xmove_fd(channel[1], 1);
3455 /* Prevent it from trying to handle ctrl-z etc */
3457 G.run_list_level = 1;
3459 /* Process substitution is not considered to be usual
3460 * 'command execution'.
3461 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3462 /* Not needed, we are relying on it being disabled
3463 * everywhere outside actual command execution. */
3464 /*set_jobctrl_sighandler(SIG_IGN);*/
3465 set_misc_sighandler(SIG_DFL);
3466 /* Freeing 'head' here would break NOMMU. */
3467 _exit(run_list(head));
3470 pf = fdopen(channel[0], "r");
3472 /* 'head' is freed by the caller */
3475 /* Return code is exit status of the process that is run. */
3476 static int process_command_subs(o_string *dest,
3477 struct in_str *input,
3478 const char *subst_end)
3480 int retcode, ch, eol_cnt;
3481 o_string result = NULL_O_STRING;
3482 struct parse_context inner;
3484 struct in_str pipe_str;
3486 initialize_context(&inner);
3488 /* Recursion to generate command */
3489 retcode = parse_stream(&result, &inner, input, subst_end);
3491 return retcode; /* syntax error or EOF */
3492 done_word(&result, &inner);
3493 done_pipe(&inner, PIPE_SEQ);
3496 p = generate_stream_from_list(inner.list_head);
3499 close_on_exec_on(fileno(p));
3500 setup_file_in_str(&pipe_str, p);
3502 /* Now send results of command back into original context */
3504 while ((ch = i_getch(&pipe_str)) != EOF) {
3510 o_addchr(dest, '\n');
3513 o_addQchr(dest, ch);
3516 debug_printf("done reading from pipe, pclose()ing\n");
3517 /* This is the step that wait()s for the child. Should be pretty
3518 * safe, since we just read an EOF from its stdout. We could try
3519 * to do better, by using wait(), and keeping track of background jobs
3520 * at the same time. That would be a lot of work, and contrary
3521 * to the KISS philosophy of this program. */
3522 retcode = fclose(p);
3523 free_pipe_list(inner.list_head, /* indent: */ 0);
3524 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3529 static int parse_group(o_string *dest, struct parse_context *ctx,
3530 struct in_str *input, int ch)
3532 /* dest contains characters seen prior to ( or {.
3533 * Typically it's empty, but for functions defs,
3534 * it contains function name (without '()'). */
3536 const char *endch = NULL;
3537 struct parse_context sub;
3538 struct command *command = ctx->command;
3540 debug_printf_parse("parse_group entered\n");
3541 #if ENABLE_HUSH_FUNCTIONS
3542 if (ch == 'F') { /* function definition? */
3543 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3544 //command->fname = dest->data;
3545 command->grp_type = GRP_FUNCTION;
3546 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3547 memset(dest, 0, sizeof(*dest));
3550 if (command->argv /* word [word](... */
3551 || dest->length /* word(... */
3552 || dest->nonnull /* ""(... */
3555 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3558 initialize_context(&sub);
3562 command->grp_type = GRP_SUBSHELL;
3564 rcode = parse_stream(dest, &sub, input, endch);
3566 done_word(dest, &sub); /* finish off the final word in the subcontext */
3567 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3568 command->group = sub.list_head;
3570 debug_printf_parse("parse_group return %d\n", rcode);
3572 /* command remains "open", available for possible redirects */
3575 #if ENABLE_HUSH_TICK
3576 /* Subroutines for copying $(...) and `...` things */
3577 static void add_till_backquote(o_string *dest, struct in_str *input);
3579 static void add_till_single_quote(o_string *dest, struct in_str *input)
3582 int ch = i_getch(input);
3590 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3591 static void add_till_double_quote(o_string *dest, struct in_str *input)
3594 int ch = i_getch(input);
3597 if (ch == '\\') { /* \x. Copy both chars. */
3599 ch = i_getch(input);
3605 add_till_backquote(dest, input);
3609 //if (ch == '$') ...
3612 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3614 * "Within the backquoted style of command substitution, backslash
3615 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3616 * The search for the matching backquote shall be satisfied by the first
3617 * backquote found without a preceding backslash; during this search,
3618 * if a non-escaped backquote is encountered within a shell comment,
3619 * a here-document, an embedded command substitution of the $(command)
3620 * form, or a quoted string, undefined results occur. A single-quoted
3621 * or double-quoted string that begins, but does not end, within the
3622 * "`...`" sequence produces undefined results."
3624 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3626 static void add_till_backquote(o_string *dest, struct in_str *input)
3629 int ch = i_getch(input);
3632 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3633 int ch2 = i_getch(input);
3634 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3643 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3644 * quoting and nested ()s.
3645 * "With the $(command) style of command substitution, all characters
3646 * following the open parenthesis to the matching closing parenthesis
3647 * constitute the command. Any valid shell script can be used for command,
3648 * except a script consisting solely of redirections which produces
3649 * unspecified results."
3651 * echo $(echo '(TEST)' BEST) (TEST) BEST
3652 * echo $(echo 'TEST)' BEST) TEST) BEST
3653 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3655 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3659 int ch = i_getch(input);
3669 add_till_single_quote(dest, input);
3674 add_till_double_quote(dest, input);
3678 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3679 ch = i_getch(input);
3687 #endif /* ENABLE_HUSH_TICK */
3689 /* Return code: 0 for OK, 1 for syntax error */
3690 static int handle_dollar(o_string *dest, struct in_str *input)
3693 int ch = i_peek(input); /* first character after the $ */
3694 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3696 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3700 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3702 debug_printf_parse(": '%c'\n", ch);
3703 o_addchr(dest, ch | quote_mask);
3706 if (!isalnum(ch) && ch != '_')
3710 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3711 } else if (isdigit(ch)) {
3714 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3715 debug_printf_parse(": '%c'\n", ch);
3716 o_addchr(dest, ch | quote_mask);
3717 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3718 } else switch (ch) {
3720 case '!': /* last bg pid */
3721 case '?': /* last exit code */
3722 case '#': /* number of args */
3723 case '*': /* args */
3724 case '@': /* args */
3725 goto make_one_char_var;
3729 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3731 /* XXX maybe someone will try to escape the '}' */
3735 ch = i_getch(input);
3739 if (ch == '#' && first_char)
3740 /* ${#var}: length of var contents */;
3742 else if (expansion < 2 && !isalnum(ch) && ch != '_') {
3743 /* handle parameter expansions
3744 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3749 case ':': /* null modifier */
3750 if (expansion == 0) {
3751 debug_printf_parse(": null modifier\n");
3757 #if 0 /* not implemented yet :( */
3758 case '#': /* remove prefix */
3759 case '%': /* remove suffix */
3760 if (expansion == 0) {
3761 debug_printf_parse(": remove suffix/prefix\n");
3768 case '-': /* default value */
3769 case '=': /* assign default */
3770 case '+': /* alternative */
3771 case '?': /* error indicate */
3772 debug_printf_parse(": parameter expansion\n");
3778 syntax("unterminated ${name}");
3779 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3783 debug_printf_parse(": '%c'\n", ch);
3784 o_addchr(dest, ch | quote_mask);
3788 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3791 #if ENABLE_HUSH_TICK
3793 //int pos = dest->length;
3795 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3796 o_addchr(dest, quote_mask | '`');
3797 add_till_closing_curly_brace(dest, input);
3798 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
3799 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3806 if (isalnum(ch)) { /* it's $_name or $_123 */
3812 /* still unhandled, but should be eventually */
3813 bb_error_msg("unhandled syntax: $%c", ch);
3817 o_addQchr(dest, '$');
3819 debug_printf_parse("handle_dollar return 0\n");
3823 /* Scan input, call done_word() whenever full IFS delimited word was seen.
3824 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
3825 * Return code is 0 if end_trigger char is met,
3826 * -1 on EOF (but if end_trigger == NULL then return 0),
3827 * 1 for syntax error */
3828 static int parse_stream(o_string *dest, struct parse_context *ctx,
3829 struct in_str *input, const char *end_trigger)
3833 redir_type redir_style;
3834 int shadow_quote = dest->o_quote;
3837 /* Only double-quote state is handled in the state variable dest->o_quote.
3838 * A single-quote triggers a bypass of the main loop until its mate is
3839 * found. When recursing, quote state is passed in via dest->o_quote. */
3841 debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
3846 ch = i_getch(input);
3850 next = i_peek(input);
3853 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3854 ch, ch, m, dest->o_quote);
3855 if (m == CHAR_ORDINARY
3856 || (m != CHAR_SPECIAL && shadow_quote)
3859 syntax("unterminated \"");
3860 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3863 o_addQchr(dest, ch);
3864 if ((dest->o_assignment == MAYBE_ASSIGNMENT
3865 || dest->o_assignment == WORD_IS_KEYWORD)
3867 && is_assignment(dest->data)
3869 dest->o_assignment = DEFINITELY_ASSIGNMENT;
3873 if (m == CHAR_IFS) {
3874 if (done_word(dest, ctx)) {
3875 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3880 /* If we aren't performing a substitution, treat
3881 * a newline as a command separator.
3882 * [why we don't handle it exactly like ';'? --vda] */
3883 if (end_trigger && ch == '\n') {
3884 #if ENABLE_HUSH_CASE
3885 /* "case ... in <newline> word) ..." -
3886 * newlines are ignored (but ';' wouldn't be) */
3887 if (dest->length == 0 // && argv[0] == NULL
3888 && ctx->ctx_res_w == RES_MATCH
3893 done_pipe(ctx, PIPE_SEQ);
3894 dest->o_assignment = MAYBE_ASSIGNMENT;
3898 if (!shadow_quote && strchr(end_trigger, ch)) {
3899 /* Special case: (...word) makes last word terminate,
3900 * as if ';' is seen */
3902 done_word(dest, ctx);
3904 done_pipe(ctx, PIPE_SEQ);
3905 dest->o_assignment = MAYBE_ASSIGNMENT;
3908 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
3910 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3918 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
3919 /* ch is a special char and thus this word
3920 * cannot be an assignment: */
3921 dest->o_assignment = NOT_ASSIGNMENT;
3926 if (dest->length == 0 && !shadow_quote) {
3929 if (ch == EOF || ch == '\n')
3934 o_addQchr(dest, ch);
3940 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3944 * "The backslash retains its special meaning [in "..."]
3945 * only when followed by one of the following characters:
3946 * $, `, ", \, or <newline>. A double quote may be quoted
3947 * within double quotes by preceding it with a backslash.
3948 * If enabled, history expansion will be performed unless
3949 * an ! appearing in double quotes is escaped using
3950 * a backslash. The backslash preceding the ! is not removed."
3952 if (shadow_quote) { //NOT SURE dest->o_quote) {
3953 if (strchr("$`\"\\", next) != NULL) {
3954 o_addqchr(dest, i_getch(input));
3956 o_addqchr(dest, '\\');
3959 o_addchr(dest, '\\');
3960 o_addchr(dest, i_getch(input));
3964 if (handle_dollar(dest, input) != 0) {
3965 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3972 ch = i_getch(input);
3974 syntax("unterminated '");
3975 debug_printf_parse("parse_stream return 1: unterminated '\n");
3980 if (dest->o_assignment == NOT_ASSIGNMENT)
3981 o_addqchr(dest, ch);
3988 shadow_quote ^= 1; /* invert */
3989 if (dest->o_assignment == NOT_ASSIGNMENT)
3992 #if ENABLE_HUSH_TICK
3994 //int pos = dest->length;
3995 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3996 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
3997 add_till_backquote(dest, input);
3998 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3999 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4004 redir_fd = redirect_opt_num(dest);
4005 done_word(dest, ctx);
4006 redir_style = REDIRECT_OVERWRITE;
4008 redir_style = REDIRECT_APPEND;
4012 else if (next == '(') {
4013 syntax(">(process) not supported");
4014 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
4018 setup_redirect(ctx, redir_fd, redir_style, input);
4021 redir_fd = redirect_opt_num(dest);
4022 done_word(dest, ctx);
4023 redir_style = REDIRECT_INPUT;
4025 redir_style = REDIRECT_HEREIS;
4027 } else if (next == '>') {
4028 redir_style = REDIRECT_IO;
4032 else if (next == '(') {
4033 syntax("<(process) not supported");
4034 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
4038 setup_redirect(ctx, redir_fd, redir_style, input);
4041 #if ENABLE_HUSH_CASE
4044 done_word(dest, ctx);
4045 done_pipe(ctx, PIPE_SEQ);
4046 #if ENABLE_HUSH_CASE
4047 /* Eat multiple semicolons, detect
4048 * whether it means something special */
4054 if (ctx->ctx_res_w == RES_CASEI) {
4055 ctx->ctx_dsemicolon = 1;
4056 ctx->ctx_res_w = RES_MATCH;
4062 /* We just finished a cmd. New one may start
4063 * with an assignment */
4064 dest->o_assignment = MAYBE_ASSIGNMENT;
4067 done_word(dest, ctx);
4070 done_pipe(ctx, PIPE_AND);
4072 done_pipe(ctx, PIPE_BG);
4076 done_word(dest, ctx);
4077 #if ENABLE_HUSH_CASE
4078 if (ctx->ctx_res_w == RES_MATCH)
4079 break; /* we are in case's "word | word)" */
4081 if (next == '|') { /* || */
4083 done_pipe(ctx, PIPE_OR);
4085 /* we could pick up a file descriptor choice here
4086 * with redirect_opt_num(), but bash doesn't do it.
4087 * "echo foo 2| cat" yields "foo 2". */
4092 #if ENABLE_HUSH_CASE
4093 /* "case... in [(]word)..." - skip '(' */
4094 if (ctx->ctx_res_w == RES_MATCH
4095 && ctx->command->argv == NULL /* not (word|(... */
4096 && dest->length == 0 /* not word(... */
4097 && dest->nonnull == 0 /* not ""(... */
4102 #if ENABLE_HUSH_FUNCTIONS
4103 if (dest->length != 0 /* not just () but word() */
4104 && dest->nonnull == 0 /* not a"b"c() */
4105 && ctx->command->argv == NULL /* it's the first word */
4106 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4107 && i_peek(input) == ')'
4108 && !match_reserved_word(dest)
4110 bb_error_msg("seems like a function definition");
4113 //TODO: do it properly.
4114 ch = i_getch(input);
4115 } while (ch == ' ' || ch == '\n');
4117 syntax("was expecting {");
4118 debug_printf_parse("parse_stream return 1\n");
4121 ch = 'F'; /* magic value */
4125 if (parse_group(dest, ctx, input, ch) != 0) {
4126 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
4131 #if ENABLE_HUSH_CASE
4132 if (ctx->ctx_res_w == RES_MATCH)
4136 /* proper use of this character is caught by end_trigger:
4137 * if we see {, we call parse_group(..., end_trigger='}')
4138 * and it will match } earlier (not here). */
4139 syntax("unexpected } or )");
4140 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
4144 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4147 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
4153 static void set_in_charmap(const char *set, int code)
4156 G.charmap[(unsigned char)*set++] = code;
4159 static void update_charmap(void)
4161 G.ifs = getenv("IFS");
4164 /* Precompute a list of 'flow through' behavior so it can be treated
4165 * quickly up front. Computation is necessary because of IFS.
4166 * Special case handling of IFS == " \t\n" is not implemented.
4167 * The charmap[] array only really needs two bits each,
4168 * and on most machines that would be faster (reduced L1 cache use).
4170 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4171 #if ENABLE_HUSH_TICK
4172 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4174 set_in_charmap("\\$\"", CHAR_SPECIAL);
4176 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4177 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4180 /* Most recursion does not come through here, the exception is
4181 * from builtin_source() and builtin_eval() */
4182 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
4184 struct parse_context ctx;
4185 o_string temp = NULL_O_STRING;
4189 initialize_context(&ctx);
4191 #if ENABLE_HUSH_INTERACTIVE
4192 inp->promptmode = 0; /* PS1 */
4194 /* We will stop & execute after each ';' or '\n'.
4195 * Example: "sleep 9999; echo TEST" + ctrl-C:
4196 * TEST should be printed */
4197 temp.o_assignment = MAYBE_ASSIGNMENT;
4198 rcode = parse_stream(&temp, &ctx, inp, ";\n");
4200 if (rcode != 1 && ctx.old_flag != 0) {
4204 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
4205 done_word(&temp, &ctx);
4206 done_pipe(&ctx, PIPE_SEQ);
4207 debug_print_tree(ctx.list_head, 0);
4208 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
4209 run_and_free_list(ctx.list_head);
4211 /* We arrive here also if rcode == 1 (error in parse_stream) */
4213 if (ctx.old_flag != 0) {
4218 /*temp.nonnull = 0; - o_free does it below */
4219 /*temp.o_quote = 0; - o_free does it below */
4220 free_pipe_list(ctx.list_head, /* indent: */ 0);
4221 /* Discard all unprocessed line input, force prompt on */
4223 #if ENABLE_HUSH_INTERACTIVE
4228 /* loop on syntax errors, return on EOF: */
4229 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
4233 static int parse_and_run_string(const char *s, int parse_flag)
4235 struct in_str input;
4236 setup_string_in_str(&input, s);
4237 return parse_and_run_stream(&input, parse_flag);
4240 static int parse_and_run_file(FILE *f)
4243 struct in_str input;
4244 setup_file_in_str(&input, f);
4245 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
4250 /* Make sure we have a controlling tty. If we get started under a job
4251 * aware app (like bash for example), make sure we are now in charge so
4252 * we don't fight over who gets the foreground */
4253 static void setup_job_control(void)
4257 shell_pgrp = getpgrp();
4258 close_on_exec_on(G.interactive_fd);
4260 /* If we were ran as 'hush &',
4261 * sleep until we are in the foreground. */
4262 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4263 /* Send TTIN to ourself (should stop us) */
4264 kill(- shell_pgrp, SIGTTIN);
4265 shell_pgrp = getpgrp();
4268 /* Ignore job-control and misc signals. */
4269 set_jobctrl_sighandler(SIG_IGN);
4270 set_misc_sighandler(SIG_IGN);
4271 //huh? signal(SIGCHLD, SIG_IGN);
4273 /* We _must_ restore tty pgrp on fatal signals */
4274 set_fatal_sighandler(sigexit);
4276 /* Put ourselves in our own process group. */
4277 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4278 /* Grab control of the terminal. */
4279 tcsetpgrp(G.interactive_fd, getpid());
4284 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4285 int hush_main(int argc, char **argv)
4287 static const struct variable const_shell_ver = {
4289 .varstr = (char*)hush_version_str,
4290 .max_len = 1, /* 0 can provoke free(name) */
4298 struct variable *cur_var;
4302 G.root_pid = getpid();
4304 /* Deal with HUSH_VERSION */
4305 G.shell_ver = const_shell_ver; /* copying struct here */
4306 G.top_var = &G.shell_ver;
4307 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4308 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4309 /* Initialize our shell local variables with the values
4310 * currently living in the environment */
4311 cur_var = G.top_var;
4314 char *value = strchr(*e, '=');
4315 if (value) { /* paranoia */
4316 cur_var->next = xzalloc(sizeof(*cur_var));
4317 cur_var = cur_var->next;
4318 cur_var->varstr = *e;
4319 cur_var->max_len = strlen(*e);
4320 cur_var->flg_export = 1;
4324 debug_printf_env("putenv '%s'\n", hush_version_str);
4325 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4327 #if ENABLE_FEATURE_EDITING
4328 G.line_input_state = new_line_input_t(FOR_SHELL);
4330 /* XXX what should these be while sourcing /etc/profile? */
4331 G.global_argc = argc;
4332 G.global_argv = argv;
4333 /* Initialize some more globals to non-zero values */
4335 #if ENABLE_HUSH_INTERACTIVE
4336 if (ENABLE_FEATURE_EDITING)
4337 cmdedit_set_initial_prompt();
4341 if (EXIT_SUCCESS) /* otherwise is already done */
4342 G.last_return_code = EXIT_SUCCESS;
4344 if (argv[0] && argv[0][0] == '-') {
4345 debug_printf("sourcing /etc/profile\n");
4346 input = fopen_for_read("/etc/profile");
4347 if (input != NULL) {
4348 close_on_exec_on(fileno(input));
4349 parse_and_run_file(input);
4355 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4356 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4359 G.global_argv = argv + optind;
4360 if (!argv[optind]) {
4361 /* -c 'script' (no params): prevent empty $0 */
4362 *--G.global_argv = argv[0];
4364 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4365 G.global_argc = argc - optind;
4366 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
4369 /* Well, we cannot just declare interactiveness,
4370 * we have to have some stuff (ctty, etc) */
4371 /* G.interactive_fd++; */
4374 /* "-s" means "read from stdin", but this is how we always
4375 * operate, so simply do nothing here. */
4379 if (!builtin_set_mode('-', opt))
4383 fprintf(stderr, "Usage: sh [FILE]...\n"
4384 " or: sh -c command [args]...\n\n");
4392 /* A shell is interactive if the '-i' flag was given, or if all of
4393 * the following conditions are met:
4395 * no arguments remaining or the -s flag given
4396 * standard input is a terminal
4397 * standard output is a terminal
4398 * Refer to Posix.2, the description of the 'sh' utility. */
4399 if (argv[optind] == NULL && input == stdin
4400 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4402 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4403 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4404 if (G.saved_tty_pgrp >= 0) {
4405 /* try to dup to high fd#, >= 255 */
4406 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4407 if (G.interactive_fd < 0) {
4408 /* try to dup to any fd */
4409 G.interactive_fd = dup(STDIN_FILENO);
4410 if (G.interactive_fd < 0)
4412 G.interactive_fd = 0;
4414 // TODO: track & disallow any attempts of user
4415 // to (inadvertently) close/redirect it
4418 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4419 if (G.interactive_fd) {
4420 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4421 /* Looks like they want an interactive shell */
4422 setup_job_control();
4423 /* -1 is special - makes xfuncs longjmp, not exit
4424 * (we reset die_sleep = 0 whereever we [v]fork) */
4426 if (setjmp(die_jmp)) {
4427 /* xfunc has failed! die die die */
4428 hush_exit(xfunc_error_retval);
4431 #elif ENABLE_HUSH_INTERACTIVE
4432 /* no job control compiled, only prompt/line editing */
4433 if (argv[optind] == NULL && input == stdin
4434 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4436 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4437 if (G.interactive_fd < 0) {
4438 /* try to dup to any fd */
4439 G.interactive_fd = dup(STDIN_FILENO);
4440 if (G.interactive_fd < 0)
4442 G.interactive_fd = 0;
4444 if (G.interactive_fd) {
4445 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4446 set_misc_sighandler(SIG_IGN);
4451 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4452 if (G.interactive_fd) {
4453 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4454 printf("Enter 'help' for a list of built-in commands.\n\n");
4458 if (argv[optind] == NULL) {
4459 opt = parse_and_run_file(stdin);
4461 debug_printf("\nrunning script '%s'\n", argv[optind]);
4462 G.global_argv = argv + optind;
4463 G.global_argc = argc - optind;
4464 input = xfopen_for_read(argv[optind]);
4465 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4466 opt = parse_and_run_file(input);
4471 #if ENABLE_FEATURE_CLEAN_UP
4473 if (G.cwd != bb_msg_unknown)
4475 cur_var = G.top_var->next;
4477 struct variable *tmp = cur_var;
4478 if (!cur_var->max_len)
4479 free(cur_var->varstr);
4480 cur_var = cur_var->next;
4484 hush_exit(opt ? opt : G.last_return_code);
4489 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4490 int lash_main(int argc, char **argv)
4492 //bb_error_msg("lash is deprecated, please use hush instead");
4493 return hush_main(argc, argv);
4501 static int builtin_true(char **argv UNUSED_PARAM)
4506 static int builtin_test(char **argv)
4513 return test_main(argc, argv - argc);
4516 static int builtin_echo(char **argv)
4523 return echo_main(argc, argv - argc);
4526 static int builtin_eval(char **argv)
4528 int rcode = EXIT_SUCCESS;
4531 char *str = expand_strvec_to_string(argv + 1);
4532 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4534 rcode = G.last_return_code;
4539 static int builtin_cd(char **argv)
4542 if (argv[1] == NULL) {
4543 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4544 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4545 newdir = getenv("HOME") ? : "/";
4548 if (chdir(newdir)) {
4549 printf("cd: %s: %s\n", newdir, strerror(errno));
4550 return EXIT_FAILURE;
4553 return EXIT_SUCCESS;
4556 static int builtin_exec(char **argv)
4558 if (argv[1] == NULL)
4559 return EXIT_SUCCESS; /* bash does this */
4564 // FIXME: if exec fails, bash does NOT exit! We do...
4565 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
4570 static int builtin_exit(char **argv)
4572 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4573 //puts("exit"); /* bash does it */
4574 // TODO: warn if we have background jobs: "There are stopped jobs"
4575 // On second consecutive 'exit', exit anyway.
4576 if (argv[1] == NULL)
4577 hush_exit(G.last_return_code);
4578 /* mimic bash: exit 123abc == exit 255 + error msg */
4579 xfunc_error_retval = 255;
4580 /* bash: exit -2 == exit 254, no error msg */
4581 hush_exit(xatoi(argv[1]) & 0xff);
4584 static int builtin_export(char **argv)
4587 char *name = argv[1];
4591 // ash emits: export VAR='VAL'
4592 // bash: declare -x VAR="VAL"
4593 // (both also escape as needed (quotes, $, etc))
4598 return EXIT_SUCCESS;
4601 value = strchr(name, '=');
4603 /* They are exporting something without a =VALUE */
4604 struct variable *var;
4606 var = get_local_var(name);
4608 var->flg_export = 1;
4609 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
4610 putenv(var->varstr);
4612 /* bash does not return an error when trying to export
4613 * an undefined variable. Do likewise. */
4614 return EXIT_SUCCESS;
4617 set_local_var(xstrdup(name), 1);
4618 return EXIT_SUCCESS;
4622 /* built-in 'fg' and 'bg' handler */
4623 static int builtin_fg_bg(char **argv)
4628 if (!G.interactive_fd)
4629 return EXIT_FAILURE;
4630 /* If they gave us no args, assume they want the last backgrounded task */
4632 for (pi = G.job_list; pi; pi = pi->next) {
4633 if (pi->jobid == G.last_jobid) {
4637 bb_error_msg("%s: no current job", argv[0]);
4638 return EXIT_FAILURE;
4640 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4641 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4642 return EXIT_FAILURE;
4644 for (pi = G.job_list; pi; pi = pi->next) {
4645 if (pi->jobid == jobnum) {
4649 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4650 return EXIT_FAILURE;
4652 // TODO: bash prints a string representation
4653 // of job being foregrounded (like "sleep 1 | cat")
4654 if (*argv[0] == 'f') {
4655 /* Put the job into the foreground. */
4656 tcsetpgrp(G.interactive_fd, pi->pgrp);
4659 /* Restart the processes in the job */
4660 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
4661 for (i = 0; i < pi->num_cmds; i++) {
4662 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
4663 pi->cmds[i].is_stopped = 0;
4665 pi->stopped_cmds = 0;
4667 i = kill(- pi->pgrp, SIGCONT);
4669 if (errno == ESRCH) {
4670 delete_finished_bg_job(pi);
4671 return EXIT_SUCCESS;
4673 bb_perror_msg("kill (SIGCONT)");
4677 if (*argv[0] == 'f') {
4679 return checkjobs_and_fg_shell(pi);
4681 return EXIT_SUCCESS;
4685 #if ENABLE_HUSH_HELP
4686 static int builtin_help(char **argv UNUSED_PARAM)
4688 const struct built_in_command *x;
4690 printf("\nBuilt-in commands:\n");
4691 printf("-------------------\n");
4692 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
4693 printf("%s\t%s\n", x->cmd, x->descr);
4696 return EXIT_SUCCESS;
4701 static int builtin_jobs(char **argv UNUSED_PARAM)
4704 const char *status_string;
4706 for (job = G.job_list; job; job = job->next) {
4707 if (job->alive_cmds == job->stopped_cmds)
4708 status_string = "Stopped";
4710 status_string = "Running";
4712 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
4714 return EXIT_SUCCESS;
4718 static int builtin_pwd(char **argv UNUSED_PARAM)
4721 return EXIT_SUCCESS;
4724 static int builtin_read(char **argv)
4727 const char *name = argv[1] ? argv[1] : "REPLY";
4729 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
4730 return set_local_var(string, 0);
4733 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
4734 * built-in 'set' handler
4736 * set [-abCefhmnuvx] [-o option] [argument...]
4737 * set [+abCefhmnuvx] [+o option] [argument...]
4738 * set -- [argument...]
4741 * Implementations shall support the options in both their hyphen and
4742 * plus-sign forms. These options can also be specified as options to sh.
4744 * Write out all variables and their values: set
4745 * Set $1, $2, and $3 and set "$#" to 3: set c a b
4746 * Turn on the -x and -v options: set -xv
4747 * Unset all positional parameters: set --
4748 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
4749 * Set the positional parameters to the expansion of x, even if x expands
4750 * with a leading '-' or '+': set -- $x
4752 * So far, we only support "set -- [argument...]" and some of the short names.
4754 static int builtin_set_mode(const char cstate, const char mode)
4756 int state = (cstate == '-' ? 1 : 0);
4758 case 'n': G.fake_mode = state; break;
4759 case 'x': /*G.debug_mode = state;*/ break;
4760 default: return EXIT_FAILURE;
4762 return EXIT_SUCCESS;
4764 static int builtin_set(char **argv)
4767 char **pp, **g_argv;
4768 char *arg = *++argv;
4772 for (e = G.top_var; e; e = e->next)
4774 return EXIT_SUCCESS;
4778 if (!strcmp(arg, "--")) {
4783 if (arg[0] == '+' || arg[0] == '-') {
4784 for (n = 1; arg[n]; ++n)
4785 if (builtin_set_mode(arg[0], arg[n]))
4791 } while ((arg = *++argv) != NULL);
4792 /* Now argv[0] is 1st argument */
4794 /* Only reset global_argv if we didn't process anything */
4796 return EXIT_SUCCESS;
4799 /* NB: G.global_argv[0] ($0) is never freed/changed */
4800 g_argv = G.global_argv;
4801 if (G.global_args_malloced) {
4807 G.global_args_malloced = 1;
4808 pp = xzalloc(sizeof(pp[0]) * 2);
4809 pp[0] = g_argv[0]; /* retain $0 */
4812 /* This realloc's G.global_argv */
4813 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
4820 return EXIT_SUCCESS;
4822 /* Nothing known, so abort */
4824 bb_error_msg("set: %s: invalid option", arg);
4825 return EXIT_FAILURE;
4828 static int builtin_shift(char **argv)
4834 if (n >= 0 && n < G.global_argc) {
4835 if (G.global_args_malloced) {
4838 free(G.global_argv[m++]);
4841 memmove(&G.global_argv[1], &G.global_argv[n+1],
4842 G.global_argc * sizeof(G.global_argv[0]));
4843 return EXIT_SUCCESS;
4845 return EXIT_FAILURE;
4848 static int builtin_source(char **argv)
4853 if (argv[1] == NULL)
4854 return EXIT_FAILURE;
4856 /* XXX search through $PATH is missing */
4857 input = fopen_for_read(argv[1]);
4859 bb_error_msg("can't open '%s'", argv[1]);
4860 return EXIT_FAILURE;
4862 close_on_exec_on(fileno(input));
4864 /* Now run the file */
4865 /* XXX argv and argc are broken; need to save old G.global_argv
4866 * (pointer only is OK!) on this stack frame,
4867 * set G.global_argv=argv+1, recurse, and restore. */
4868 status = parse_and_run_file(input);
4873 static int builtin_umask(char **argv)
4876 const char *arg = argv[1];
4879 new_umask = strtoul(arg, &end, 8);
4880 if (*end != '\0' || end == arg) {
4881 return EXIT_FAILURE;
4884 new_umask = umask(0);
4885 printf("%.3o\n", (unsigned) new_umask);
4888 return EXIT_SUCCESS;
4891 static int builtin_unset(char **argv)
4893 /* bash always returns true */
4894 unset_local_var(argv[1]);
4895 return EXIT_SUCCESS;
4898 #if ENABLE_HUSH_LOOPS
4899 static int builtin_break(char **argv)
4901 if (G.depth_of_loop == 0) {
4902 bb_error_msg("%s: only meaningful in a loop", argv[0]);
4903 return EXIT_SUCCESS; /* bash compat */
4905 G.flag_break_continue++; /* BC_BREAK = 1 */
4906 G.depth_break_continue = 1;
4908 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
4909 if (errno || !G.depth_break_continue || argv[2]) {
4910 bb_error_msg("%s: bad arguments", argv[0]);
4911 G.flag_break_continue = BC_BREAK;
4912 G.depth_break_continue = UINT_MAX;
4915 if (G.depth_of_loop < G.depth_break_continue)
4916 G.depth_break_continue = G.depth_of_loop;
4917 return EXIT_SUCCESS;
4920 static int builtin_continue(char **argv)
4922 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
4923 return builtin_break(argv);
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