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 * <(list) and >(list) Process Substitution
42 * Here Documents ( << word )
45 * Parameter Expansion for substring processing ${var#word} ${var%word}
47 * Bash stuff maybe optional enable:
48 * &> and >& redirection of stdout+stderr
50 * reserved words: [[ ]] function select
51 * substrings ${var:1:5}
54 * job handling woefully incomplete and buggy (improved --vda)
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * change { and } from special chars to reserved words
58 * builtins: return, trap, ulimit
59 * test magic exec with redirection only
60 * follow IFS rules more precisely, including update semantics
61 * figure out what to do with backslash-newline
62 * propagate syntax errors, die on resource errors?
63 * continuation lines, both explicit and implicit - done?
64 * maybe change charmap[] to use 2-bit entries
66 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
69 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
70 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
71 //#include "applet_tables.h" doesn't work
73 /* #include <dmalloc.h> */
80 #define HUSH_VER_STR "0.92"
82 #if defined SINGLE_APPLET_MAIN
83 /* STANDALONE does not make sense, and won't compile */
84 #undef CONFIG_FEATURE_SH_STANDALONE
85 #undef ENABLE_FEATURE_SH_STANDALONE
86 #undef USE_FEATURE_SH_STANDALONE
87 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
88 #define ENABLE_FEATURE_SH_STANDALONE 0
89 #define USE_FEATURE_SH_STANDALONE(...)
90 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
93 #if !BB_MMU && ENABLE_HUSH_TICK
94 //#undef ENABLE_HUSH_TICK
95 //#define ENABLE_HUSH_TICK 0
96 #warning On NOMMU, hush command substitution is dangerous.
97 #warning Dont use it for commands which produce lots of output.
98 #warning For more info see shell/hush.c, generate_stream_from_list().
101 #if !ENABLE_HUSH_INTERACTIVE
102 #undef ENABLE_FEATURE_EDITING
103 #define ENABLE_FEATURE_EDITING 0
104 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
105 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
108 /* Do we support ANY keywords? */
109 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
110 #define HAS_KEYWORDS 1
111 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
112 #define IF_HAS_NO_KEYWORDS(...)
114 #define HAS_KEYWORDS 0
115 #define IF_HAS_KEYWORDS(...)
116 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
119 /* Keep unconditionally on for now */
122 #define ENABLE_HUSH_FUNCTIONS 0
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
141 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
144 #ifndef debug_printf_parse
145 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
148 #ifndef debug_printf_exec
149 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
152 #ifndef debug_printf_env
153 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
156 #ifndef debug_printf_jobs
157 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
163 #ifndef debug_printf_expand
164 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
165 #define DEBUG_EXPAND 1
167 #define DEBUG_EXPAND 0
170 #ifndef debug_printf_glob
171 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
177 #ifndef debug_printf_list
178 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
181 #ifndef debug_printf_subst
182 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
185 #ifndef debug_printf_clean
186 /* broken, of course, but OK for testing */
187 static const char *indenter(int i)
189 static const char blanks[] ALIGN1 =
191 return &blanks[sizeof(blanks) - i - 1];
193 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
194 #define DEBUG_CLEAN 1
198 static void debug_print_strings(const char *prefix, char **vv)
200 fprintf(stderr, "%s:\n", prefix);
202 fprintf(stderr, " '%s'\n", *vv++);
205 #define debug_print_strings(prefix, vv) ((void)0)
209 * Leak hunting. Use hush_leaktool.sh for post-processing.
211 #ifdef FOR_HUSH_LEAKTOOL
212 /* suppress "warning: no previous prototype..." */
213 void *xxmalloc(int lineno, size_t size);
214 void *xxrealloc(int lineno, void *ptr, size_t size);
215 char *xxstrdup(int lineno, const char *str);
216 void xxfree(void *ptr);
217 void *xxmalloc(int lineno, size_t size)
219 void *ptr = xmalloc((size + 0xff) & ~0xff);
220 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
223 void *xxrealloc(int lineno, void *ptr, size_t size)
225 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
226 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
229 char *xxstrdup(int lineno, const char *str)
231 char *ptr = xstrdup(str);
232 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
235 void xxfree(void *ptr)
237 fdprintf(2, "free %p\n", ptr);
240 #define xmalloc(s) xxmalloc(__LINE__, s)
241 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
242 #define xstrdup(s) xxstrdup(__LINE__, s)
243 #define free(p) xxfree(p)
247 #define ERR_PTR ((void*)(long)1)
249 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
251 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
253 #define SPECIAL_VAR_SYMBOL 3
255 typedef enum redir_type {
257 REDIRECT_OVERWRITE = 2,
263 /* The descrip member of this structure is only used to make
264 * debugging output pretty */
265 static const struct {
267 signed char default_fd;
271 { O_RDONLY, 0, "<" },
272 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
273 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
274 { O_RDONLY, -1, "<<" },
278 typedef enum pipe_style {
285 typedef enum reserved_style {
294 #if ENABLE_HUSH_LOOPS
301 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
306 /* two pseudo-keywords support contrived "case" syntax: */
307 RES_MATCH , /* "word)" */
308 RES_CASEI , /* "this command is inside CASE" */
315 struct redir_struct {
316 struct redir_struct *next;
317 char *rd_filename; /* filename */
318 int fd; /* file descriptor being redirected */
319 int dup; /* -1, or file descriptor being duplicated */
320 smallint /*enum redir_type*/ rd_type;
324 pid_t pid; /* 0 if exited */
325 int assignment_cnt; /* how many argv[i] are assignments? */
326 smallint is_stopped; /* is the command currently running? */
327 smallint grp_type; /* GRP_xxx */
328 struct pipe *group; /* if non-NULL, this "prog" is {} group,
329 * subshell, or a compound statement */
330 char **argv; /* command name and arguments */
331 struct redir_struct *redirects; /* I/O redirections */
333 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
334 * and on execution these are substituted with their values.
335 * Substitution can make _several_ words out of one argv[n]!
336 * Example: argv[0]=='.^C*^C.' here: echo .$*.
337 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
340 #define GRP_SUBSHELL 1
341 #if ENABLE_HUSH_FUNCTIONS
342 #define GRP_FUNCTION 2
347 int num_cmds; /* total number of commands in job */
348 int alive_cmds; /* number of commands running (not exited) */
349 int stopped_cmds; /* number of commands alive, but stopped */
351 int jobid; /* job number */
352 pid_t pgrp; /* process group ID for the job */
353 char *cmdtext; /* name of job */
355 struct command *cmds; /* array of commands in pipe */
356 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
357 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
358 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
361 /* This holds pointers to the various results of parsing */
362 struct parse_context {
363 /* linked list of pipes */
364 struct pipe *list_head;
365 /* last pipe (being constructed right now) */
367 /* last command in pipe (being constructed right now) */
368 struct command *command;
369 /* last redirect in command->redirects list */
370 struct redir_struct *pending_redirect;
373 smallint ctx_inverted; /* "! cmd | cmd" */
375 smallint ctx_dsemicolon; /* ";;" seen */
377 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
379 /* group we are enclosed in:
380 * example 1: "{ { false; ..."
381 * example 2: "if true; then { false; ..."
382 * example 3: "if true; then if false; ..."
383 * when we find closing "}" / "fi" / whatever, we move list_head
384 * into stack->command->group and delete ourself.
386 struct parse_context *stack;
390 /* On program start, environ points to initial environment.
391 * putenv adds new pointers into it, unsetenv removes them.
392 * Neither of these (de)allocates the strings.
393 * setenv allocates new strings in malloc space and does putenv,
394 * and thus setenv is unusable (leaky) for shell's purposes */
395 #define setenv(...) setenv_is_leaky_dont_use()
397 struct variable *next;
398 char *varstr; /* points to "name=" portion */
399 int max_len; /* if > 0, name is part of initial env; else name is malloced */
400 smallint flg_export; /* putenv should be done on this var */
401 smallint flg_read_only;
404 typedef struct o_string {
406 int length; /* position where data is appended */
408 /* Protect newly added chars against globbing
409 * (by prepending \ to *, ?, [, \) */
413 smallint has_empty_slot;
414 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
417 MAYBE_ASSIGNMENT = 0,
418 DEFINITELY_ASSIGNMENT = 1,
420 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
422 /* Used for initialization: o_string foo = NULL_O_STRING; */
423 #define NULL_O_STRING { NULL }
425 /* I can almost use ordinary FILE*. Is open_memstream() universally
426 * available? Where is it documented? */
427 typedef struct in_str {
429 /* eof_flag=1: last char in ->p is really an EOF */
430 char eof_flag; /* meaningless if ->p == NULL */
432 #if ENABLE_HUSH_INTERACTIVE
434 smallint promptmode; /* 0: PS1, 1: PS2 */
437 int (*get) (struct in_str *);
438 int (*peek) (struct in_str *);
440 #define i_getch(input) ((input)->get(input))
441 #define i_peek(input) ((input)->peek(input))
445 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
446 CHAR_IFS = 2, /* treated as ordinary if quoted */
447 CHAR_SPECIAL = 3, /* \, $, ", maybe ` */
456 /* "Globals" within this file */
457 /* Sorted roughly by size (smaller offsets == smaller code) */
459 #if ENABLE_HUSH_INTERACTIVE
460 /* 'interactive_fd' is a fd# open to ctty, if we have one
461 * _AND_ if we decided to act interactively */
465 #define G_interactive_fd (G.interactive_fd)
467 #define G_interactive_fd 0
469 #if ENABLE_FEATURE_EDITING
470 line_input_t *line_input_state;
476 pid_t saved_tty_pgrp;
478 struct pipe *job_list;
479 struct pipe *toplevel_list;
480 //// smallint ctrl_z_flag;
482 smallint flag_SIGINT;
483 #if ENABLE_HUSH_LOOPS
484 smallint flag_break_continue;
487 /* These four support $?, $#, and $1 */
488 smalluint last_return_code;
489 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
490 smalluint global_args_malloced;
491 /* how many non-NULL argv's we have. NB: $# + 1 */
494 #if ENABLE_HUSH_LOOPS
495 unsigned depth_break_continue;
496 unsigned depth_of_loop;
500 struct variable *top_var; /* = &G.shell_ver (set in main()) */
501 struct variable shell_ver;
502 #if ENABLE_FEATURE_SH_STANDALONE
503 struct nofork_save_area nofork_save;
506 sigjmp_buf toplevel_jb;
508 unsigned char charmap[256];
509 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
510 /* Signal and trap handling */
511 // unsigned count_SIGCHLD;
512 // unsigned handled_SIGCHLD;
513 /* which signals have non-DFL handler (even with no traps set)? */
514 unsigned non_DFL_mask;
515 char **traps; /* char *traps[NSIG] */
516 sigset_t blocked_set;
517 sigset_t inherited_set;
519 #define G (*ptr_to_globals)
520 /* Not #defining name to G.name - this quickly gets unwieldy
521 * (too many defines). Also, I actually prefer to see when a variable
522 * is global, thus "G." prefix is a useful hint */
523 #define INIT_G() do { \
524 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
528 /* Function prototypes for builtins */
529 static int builtin_cd(char **argv);
530 static int builtin_echo(char **argv);
531 static int builtin_eval(char **argv);
532 static int builtin_exec(char **argv);
533 static int builtin_exit(char **argv);
534 static int builtin_export(char **argv);
536 static int builtin_fg_bg(char **argv);
537 static int builtin_jobs(char **argv);
540 static int builtin_help(char **argv);
542 static int builtin_pwd(char **argv);
543 static int builtin_read(char **argv);
544 static int builtin_test(char **argv);
545 static int builtin_trap(char **argv);
546 static int builtin_true(char **argv);
547 static int builtin_set(char **argv);
548 static int builtin_shift(char **argv);
549 static int builtin_source(char **argv);
550 static int builtin_umask(char **argv);
551 static int builtin_unset(char **argv);
552 static int builtin_wait(char **argv);
553 #if ENABLE_HUSH_LOOPS
554 static int builtin_break(char **argv);
555 static int builtin_continue(char **argv);
557 //static int builtin_not_written(char **argv);
559 /* Table of built-in functions. They can be forked or not, depending on
560 * context: within pipes, they fork. As simple commands, they do not.
561 * When used in non-forking context, they can change global variables
562 * in the parent shell process. If forked, of course they cannot.
563 * For example, 'unset foo | whatever' will parse and run, but foo will
564 * still be set at the end. */
565 struct built_in_command {
567 int (*function)(char **argv);
570 #define BLTIN(cmd, func, help) { cmd, func, help }
572 #define BLTIN(cmd, func, help) { cmd, func }
576 /* For now, echo and test are unconditionally enabled.
577 * Maybe make it configurable? */
578 static const struct built_in_command bltins[] = {
579 BLTIN("." , builtin_source, "Run commands in a file"),
580 BLTIN(":" , builtin_true, "No-op"),
581 BLTIN("[" , builtin_test, "Test condition"),
583 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
585 #if ENABLE_HUSH_LOOPS
586 BLTIN("break" , builtin_break, "Exit from a loop"),
588 BLTIN("cd" , builtin_cd, "Change directory"),
589 #if ENABLE_HUSH_LOOPS
590 BLTIN("continue", builtin_continue, "Start new loop iteration"),
592 BLTIN("echo" , builtin_echo, "Write to stdout"),
593 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
594 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
595 BLTIN("exit" , builtin_exit, "Exit"),
596 BLTIN("export", builtin_export, "Set environment variable"),
598 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
599 BLTIN("jobs" , builtin_jobs, "List active jobs"),
601 BLTIN("pwd" , builtin_pwd, "Print current directory"),
602 BLTIN("read" , builtin_read, "Input environment variable"),
603 // BLTIN("return", builtin_not_written, "Return from a function"),
604 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
605 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
606 BLTIN("test" , builtin_test, "Test condition"),
607 BLTIN("trap" , builtin_trap, "Trap signals"),
608 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
609 BLTIN("umask" , builtin_umask, "Set file creation mask"),
610 BLTIN("unset" , builtin_unset, "Unset environment variable"),
611 BLTIN("wait" , builtin_wait, "Wait for process"),
613 BLTIN("help" , builtin_help, "List shell built-in commands"),
619 static void maybe_die(const char *notice, const char *msg)
621 /* Was using fancy stuff:
622 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
623 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
624 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
625 #if ENABLE_HUSH_INTERACTIVE
626 fp = (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die);
628 fp(msg ? "%s: %s" : notice, notice, msg);
631 #define syntax(msg) maybe_die("syntax error", msg);
633 /* Debug -- trick gcc to expand __LINE__ and convert to string */
634 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
635 #define _syntax(msg, line) __syntax(msg, line)
636 #define syntax(msg) _syntax(msg, __LINE__)
639 static int glob_needed(const char *s)
644 if (*s == '*' || *s == '[' || *s == '?')
651 static int is_assignment(const char *s)
653 if (!s || !(isalpha(*s) || *s == '_'))
656 while (isalnum(*s) || *s == '_')
661 /* Replace each \x with x in place, return ptr past NUL. */
662 static char *unbackslash(char *src)
668 if ((*dst++ = *src++) == '\0')
674 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
695 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
696 v[count1 + count2] = NULL;
699 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
703 static char **add_string_to_strings(char **strings, char *add)
708 return add_strings_to_strings(strings, v, /*dup:*/ 0);
711 static void putenv_all(char **strings)
716 debug_printf_env("putenv '%s'\n", *strings);
721 static char **putenv_all_and_save_old(char **strings)
731 eq = strchr(*strings, '=');
734 v = getenv(*strings);
737 /* v points to VAL in VAR=VAL, go back to VAR */
738 v -= (eq - *strings) + 1;
739 old = add_string_to_strings(old, v);
748 static void free_strings_and_unsetenv(char **strings, int unset)
758 debug_printf_env("unsetenv '%s'\n", *v);
766 static void free_strings(char **strings)
768 free_strings_and_unsetenv(strings, 0);
772 /* Basic theory of signal handling in shell
773 * ========================================
774 * This does not describe what hush does, rather, it is current understanding
775 * what it _should_ do. If it doesn't, it's a bug.
776 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
778 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
779 * is finished or backgrounded. It is the same in interactive and
780 * non-interactive shells, and is the same regardless of whether
781 * a user trap handler is installed or a shell special one is in effect.
782 * ^C or ^Z from keyboard seem to execute "at once" because it usually
783 * backgrounds (i.e. stops) or kills all members of currently running
786 * Wait builtin in interruptible by signals for which user trap is set
787 * or by SIGINT in interactive shell.
789 * Trap handlers will execute even within trap handlers. (right?)
791 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
793 * If job control is off, backgrounded commands ("cmd &")
794 * have SIGINT, SIGQUIT set to SIG_IGN.
796 * Commands run in command substitution ("`cmd`")
797 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
799 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
800 * by the shell from its parent.
802 * Siganls which differ from SIG_DFL action
803 * (note: child (i.e., [v]forked) shell is not an interactive shell):
806 * SIGTERM (interactive): ignore
807 * SIGHUP (interactive):
808 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
809 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
810 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
811 * that all pipe members are stopped) (right?)
812 * SIGINT (interactive): wait for last pipe, ignore the rest
813 * of the command line, show prompt. NB: ^C does not send SIGINT
814 * to interactive shell while shell is waiting for a pipe,
815 * since shell is bg'ed (is not in foreground process group).
816 * (check/expand this)
817 * Example 1: this waits 5 sec, but does not execute ls:
818 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
819 * Example 2: this does not wait and does not execute ls:
820 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
821 * Example 3: this does not wait 5 sec, but executes ls:
822 * "sleep 5; ls -l" + press ^C
824 * (What happens to signals which are IGN on shell start?)
825 * (What happens with signal mask on shell start?)
827 * Implementation in hush
828 * ======================
829 * We use in-kernel pending signal mask to determine which signals were sent.
830 * We block all signals which we don't want to take action immediately,
831 * i.e. we block all signals which need to have special handling as described
832 * above, and all signals which have traps set.
833 * After each pipe execution, we extract any pending signals via sigtimedwait()
836 * unsigned non_DFL_mask: a mask of such "special" signals
837 * sigset_t blocked_set: current blocked signal set
840 * clear bit in blocked_set unless it is also in non_DFL
841 * "trap 'cmd' SIGxxx":
842 * set bit in blocked_set (even if 'cmd' is '')
843 * after [v]fork, if we plan to be a shell:
844 * nothing for {} child shell (say, "true | { true; true; } | true")
845 * unset all traps if () shell. [TODO]
846 * after [v]fork, if we plan to exec:
847 * POSIX says pending signal mask is cleared in child - no need to clear it.
848 * Restore blocked signal set to one inherited by shell just prior to exec.
850 * Note: as a result, we do not use signal handlers much. The only uses
851 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
852 * and to restore tty pgrp on signal-induced exit.
854 * TODO: check/fix wait builtin to be interruptible.
857 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
859 // G.count_SIGCHLD++;
862 /* called once at shell init */
863 static void init_signal_mask(void)
866 unsigned mask = (1 << SIGQUIT);
867 if (G_interactive_fd) {
873 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
878 G.non_DFL_mask = mask;
880 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
884 sigaddset(&G.blocked_set, sig);
888 sigdelset(&G.blocked_set, SIGCHLD);
889 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
892 static int check_and_run_traps(int sig)
894 static const struct timespec zero_timespec = { 0, 0 };
895 smalluint save_rcode;
901 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
906 if (G.traps && G.traps[sig]) {
907 if (G.traps[sig][0]) {
908 /* We have user-defined handler */
909 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
910 save_rcode = G.last_return_code;
913 G.last_return_code = save_rcode;
914 } /* else: "" trap, ignoring signal */
917 /* not a trap: special action */
920 // G.count_SIGCHLD++;
929 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
938 /* Restores tty foreground process group, and exits.
939 * May be called as signal handler for fatal signal
940 * (will faithfully resend signal to itself, producing correct exit state)
941 * or called directly with -EXITCODE.
942 * We also call it if xfunc is exiting. */
943 static void sigexit(int sig) NORETURN;
944 static void sigexit(int sig)
946 /* Disable all signals: job control, SIGPIPE, etc. */
947 sigprocmask_allsigs(SIG_BLOCK);
949 /* Careful: we can end up here after [v]fork. Do not restore
950 * tty pgrp then, only top-level shell process does that */
951 if (G_interactive_fd && getpid() == G.root_pid)
952 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
954 /* Not a signal, just exit */
958 kill_myself_with_sig(sig); /* does not return */
962 static void maybe_set_sighandler(int sig)
964 void (*handler)(int);
965 /* non_DFL_mask'ed signals are, well, masked,
966 * no need to set handler for them.
968 if (!((G.non_DFL_mask >> sig) & 1)) {
969 handler = signal(sig, sigexit);
970 if (handler == SIG_IGN) /* oops... restore back to IGN! */
971 signal(sig, handler);
974 /* Used only to set handler to restore pgrp on exit */
975 static void set_fatal_signals_to_sigexit(void)
978 maybe_set_sighandler(SIGILL );
979 maybe_set_sighandler(SIGFPE );
980 maybe_set_sighandler(SIGBUS );
981 maybe_set_sighandler(SIGSEGV);
982 maybe_set_sighandler(SIGTRAP);
983 } /* else: hush is perfect. what SEGV? */
985 maybe_set_sighandler(SIGABRT);
987 /* bash 3.2 seems to handle these just like 'fatal' ones */
988 maybe_set_sighandler(SIGPIPE);
989 maybe_set_sighandler(SIGALRM);
990 maybe_set_sighandler(SIGHUP );
992 /* if we aren't interactive... but in this case
993 * we never want to restore pgrp on exit, and this fn is not called */
994 /*maybe_set_sighandler(SIGTERM);*/
995 /*maybe_set_sighandler(SIGINT );*/
1000 #define set_fatal_signals_to_sigexit(handler) ((void)0)
1004 /* Restores tty foreground process group, and exits. */
1005 static void hush_exit(int exitcode) NORETURN;
1006 static void hush_exit(int exitcode)
1008 if (G.traps && G.traps[0] && G.traps[0][0]) {
1009 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1015 fflush(NULL); /* flush all streams */
1016 sigexit(- (exitcode & 0xff));
1023 static const char *set_cwd(void)
1025 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1026 * we must not try to free(bb_msg_unknown) */
1027 if (G.cwd == bb_msg_unknown)
1029 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1031 G.cwd = bb_msg_unknown;
1036 /* Get/check local shell variables */
1037 static struct variable *get_local_var(const char *name)
1039 struct variable *cur;
1045 for (cur = G.top_var; cur; cur = cur->next) {
1046 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1052 /* Basically useful version until someone wants to get fancier,
1053 * see the bash man page under "Parameter Expansion" */
1054 static const char *lookup_param(const char *src)
1056 struct variable *var = get_local_var(src);
1058 return strchr(var->varstr, '=') + 1;
1062 /* str holds "NAME=VAL" and is expected to be malloced.
1063 * We take ownership of it.
1064 * flg_export is used by:
1067 * -1: if NAME is set, leave export status alone
1068 * if NAME is not set, do not export
1070 static int set_local_var(char *str, int flg_export)
1072 struct variable *cur;
1076 value = strchr(str, '=');
1077 if (!value) { /* not expected to ever happen? */
1082 name_len = value - str + 1; /* including '=' */
1083 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1085 if (strncmp(cur->varstr, str, name_len) != 0) {
1087 /* Bail out. Note that now cur points
1088 * to last var in linked list */
1094 /* We found an existing var with this name */
1096 if (cur->flg_read_only) {
1097 bb_error_msg("%s: readonly variable", str);
1101 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1102 unsetenv(str); /* just in case */
1104 if (strcmp(cur->varstr, str) == 0) {
1109 if (cur->max_len >= strlen(str)) {
1110 /* This one is from startup env, reuse space */
1111 strcpy(cur->varstr, str);
1114 /* max_len == 0 signifies "malloced" var, which we can
1115 * (and has to) free */
1119 goto set_str_and_exp;
1122 /* Not found - create next variable struct */
1123 cur->next = xzalloc(sizeof(*cur));
1129 if (flg_export == 1)
1130 cur->flg_export = 1;
1131 if (cur->flg_export) {
1132 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1133 return putenv(cur->varstr);
1138 static int unset_local_var(const char *name)
1140 struct variable *cur;
1141 struct variable *prev = prev; /* for gcc */
1145 return EXIT_SUCCESS;
1146 name_len = strlen(name);
1149 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1150 if (cur->flg_read_only) {
1151 bb_error_msg("%s: readonly variable", name);
1152 return EXIT_FAILURE;
1154 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1155 * is ro, and we cannot reach this code on the 1st pass */
1156 prev->next = cur->next;
1157 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1158 bb_unsetenv(cur->varstr);
1162 return EXIT_SUCCESS;
1167 return EXIT_SUCCESS;
1170 #if ENABLE_SH_MATH_SUPPORT
1171 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1172 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1173 static char *endofname(const char *name)
1181 if (!is_in_name(*p))
1187 static void arith_set_local_var(const char *name, const char *val, int flags)
1189 /* arith code doesnt malloc space, so do it for it */
1190 char *var = xasprintf("%s=%s", name, val);
1191 set_local_var(var, flags);
1199 static int static_get(struct in_str *i)
1208 static int static_peek(struct in_str *i)
1213 #if ENABLE_HUSH_INTERACTIVE
1215 static void cmdedit_set_initial_prompt(void)
1217 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1218 G.PS1 = getenv("PS1");
1225 static const char* setup_prompt_string(int promptmode)
1227 const char *prompt_str;
1228 debug_printf("setup_prompt_string %d ", promptmode);
1229 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1230 /* Set up the prompt */
1231 if (promptmode == 0) { /* PS1 */
1233 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1238 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1239 debug_printf("result '%s'\n", prompt_str);
1243 static void get_user_input(struct in_str *i)
1246 const char *prompt_str;
1248 prompt_str = setup_prompt_string(i->promptmode);
1249 #if ENABLE_FEATURE_EDITING
1250 /* Enable command line editing only while a command line
1251 * is actually being read */
1254 /* buglet: SIGINT will not make new prompt to appear _at once_,
1255 * only after <Enter>. (^C will work) */
1256 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1257 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1258 check_and_run_traps(0);
1259 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1260 i->eof_flag = (r < 0);
1261 if (i->eof_flag) { /* EOF/error detected */
1262 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1263 G.user_input_buf[1] = '\0';
1268 fputs(prompt_str, stdout);
1270 G.user_input_buf[0] = r = fgetc(i->file);
1271 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1272 //do we need check_and_run_traps(0)? (maybe only if stdin)
1273 } while (G.flag_SIGINT);
1274 i->eof_flag = (r == EOF);
1276 i->p = G.user_input_buf;
1279 #endif /* INTERACTIVE */
1281 /* This is the magic location that prints prompts
1282 * and gets data back from the user */
1283 static int file_get(struct in_str *i)
1287 /* If there is data waiting, eat it up */
1288 if (i->p && *i->p) {
1289 #if ENABLE_HUSH_INTERACTIVE
1293 if (i->eof_flag && !*i->p)
1296 /* need to double check i->file because we might be doing something
1297 * more complicated by now, like sourcing or substituting. */
1298 #if ENABLE_HUSH_INTERACTIVE
1299 if (G_interactive_fd && i->promptme && i->file == stdin) {
1302 } while (!*i->p); /* need non-empty line */
1303 i->promptmode = 1; /* PS2 */
1308 ch = fgetc(i->file);
1310 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1311 #if ENABLE_HUSH_INTERACTIVE
1318 /* All the callers guarantee this routine will never be
1319 * used right after a newline, so prompting is not needed.
1321 static int file_peek(struct in_str *i)
1324 if (i->p && *i->p) {
1325 if (i->eof_flag && !i->p[1])
1329 ch = fgetc(i->file);
1330 i->eof_flag = (ch == EOF);
1331 i->peek_buf[0] = ch;
1332 i->peek_buf[1] = '\0';
1334 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1338 static void setup_file_in_str(struct in_str *i, FILE *f)
1340 i->peek = file_peek;
1342 #if ENABLE_HUSH_INTERACTIVE
1344 i->promptmode = 0; /* PS1 */
1350 static void setup_string_in_str(struct in_str *i, const char *s)
1352 i->peek = static_peek;
1353 i->get = static_get;
1354 #if ENABLE_HUSH_INTERACTIVE
1356 i->promptmode = 0; /* PS1 */
1366 #define B_CHUNK (32 * sizeof(char*))
1368 static void o_reset(o_string *o)
1376 static void o_free(o_string *o)
1379 memset(o, 0, sizeof(*o));
1382 static void o_grow_by(o_string *o, int len)
1384 if (o->length + len > o->maxlen) {
1385 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1386 o->data = xrealloc(o->data, 1 + o->maxlen);
1390 static void o_addchr(o_string *o, int ch)
1392 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1394 o->data[o->length] = ch;
1396 o->data[o->length] = '\0';
1399 static void o_addstr(o_string *o, const char *str, int len)
1402 memcpy(&o->data[o->length], str, len);
1404 o->data[o->length] = '\0';
1407 static void o_addstrauto(o_string *o, const char *str)
1409 o_addstr(o, str, strlen(str) + 1);
1412 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1417 && (*str != '*' && *str != '?' && *str != '[')
1425 /* My analysis of quoting semantics tells me that state information
1426 * is associated with a destination, not a source.
1428 static void o_addqchr(o_string *o, int ch)
1431 char *found = strchr("*?[\\", ch);
1436 o->data[o->length] = '\\';
1439 o->data[o->length] = ch;
1441 o->data[o->length] = '\0';
1444 static void o_addQchr(o_string *o, int ch)
1447 if (o->o_escape && strchr("*?[\\", ch)) {
1449 o->data[o->length] = '\\';
1453 o->data[o->length] = ch;
1455 o->data[o->length] = '\0';
1458 static void o_addQstr(o_string *o, const char *str, int len)
1461 o_addstr(o, str, len);
1467 int ordinary_cnt = strcspn(str, "*?[\\");
1468 if (ordinary_cnt > len) /* paranoia */
1470 o_addstr(o, str, ordinary_cnt);
1471 if (ordinary_cnt == len)
1473 str += ordinary_cnt;
1474 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1478 if (ch) { /* it is necessarily one of "*?[\\" */
1480 o->data[o->length] = '\\';
1484 o->data[o->length] = ch;
1486 o->data[o->length] = '\0';
1490 /* A special kind of o_string for $VAR and `cmd` expansion.
1491 * It contains char* list[] at the beginning, which is grown in 16 element
1492 * increments. Actual string data starts at the next multiple of 16 * (char*).
1493 * list[i] contains an INDEX (int!) into this string data.
1494 * It means that if list[] needs to grow, data needs to be moved higher up
1495 * but list[i]'s need not be modified.
1496 * NB: remembering how many list[i]'s you have there is crucial.
1497 * o_finalize_list() operation post-processes this structure - calculates
1498 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1500 #if DEBUG_EXPAND || DEBUG_GLOB
1501 static void debug_print_list(const char *prefix, o_string *o, int n)
1503 char **list = (char**)o->data;
1504 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1506 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1507 prefix, list, n, string_start, o->length, o->maxlen);
1509 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1510 o->data + (int)list[i] + string_start,
1511 o->data + (int)list[i] + string_start);
1515 const char *p = o->data + (int)list[n - 1] + string_start;
1516 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1520 #define debug_print_list(prefix, o, n) ((void)0)
1523 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1524 * in list[n] so that it points past last stored byte so far.
1525 * It returns n+1. */
1526 static int o_save_ptr_helper(o_string *o, int n)
1528 char **list = (char**)o->data;
1532 if (!o->has_empty_slot) {
1533 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1534 string_len = o->length - string_start;
1535 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1536 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1537 /* list[n] points to string_start, make space for 16 more pointers */
1538 o->maxlen += 0x10 * sizeof(list[0]);
1539 o->data = xrealloc(o->data, o->maxlen + 1);
1540 list = (char**)o->data;
1541 memmove(list + n + 0x10, list + n, string_len);
1542 o->length += 0x10 * sizeof(list[0]);
1544 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1546 /* We have empty slot at list[n], reuse without growth */
1547 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1548 string_len = o->length - string_start;
1549 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1550 o->has_empty_slot = 0;
1552 list[n] = (char*)(ptrdiff_t)string_len;
1556 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1557 static int o_get_last_ptr(o_string *o, int n)
1559 char **list = (char**)o->data;
1560 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1562 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1565 /* o_glob performs globbing on last list[], saving each result
1566 * as a new list[]. */
1567 static int o_glob(o_string *o, int n)
1573 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1575 return o_save_ptr_helper(o, n);
1576 pattern = o->data + o_get_last_ptr(o, n);
1577 debug_printf_glob("glob pattern '%s'\n", pattern);
1578 if (!glob_needed(pattern)) {
1580 o->length = unbackslash(pattern) - o->data;
1581 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1582 return o_save_ptr_helper(o, n);
1585 memset(&globdata, 0, sizeof(globdata));
1586 gr = glob(pattern, 0, NULL, &globdata);
1587 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1588 if (gr == GLOB_NOSPACE)
1589 bb_error_msg_and_die("out of memory during glob");
1590 if (gr == GLOB_NOMATCH) {
1591 globfree(&globdata);
1594 if (gr != 0) { /* GLOB_ABORTED ? */
1595 //TODO: testcase for bad glob pattern behavior
1596 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1598 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1599 char **argv = globdata.gl_pathv;
1600 o->length = pattern - o->data; /* "forget" pattern */
1602 o_addstrauto(o, *argv);
1603 n = o_save_ptr_helper(o, n);
1609 globfree(&globdata);
1611 debug_print_list("o_glob returning", o, n);
1615 /* If o->o_glob == 1, glob the string so far remembered.
1616 * Otherwise, just finish current list[] and start new */
1617 static int o_save_ptr(o_string *o, int n)
1619 if (o->o_glob) { /* if globbing is requested */
1620 /* If o->has_empty_slot, list[n] was already globbed
1621 * (if it was requested back then when it was filled)
1622 * so don't do that again! */
1623 if (!o->has_empty_slot)
1624 return o_glob(o, n); /* o_save_ptr_helper is inside */
1626 return o_save_ptr_helper(o, n);
1629 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1630 static char **o_finalize_list(o_string *o, int n)
1635 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1637 debug_print_list("finalized", o, n);
1638 debug_printf_expand("finalized n:%d\n", n);
1639 list = (char**)o->data;
1640 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1644 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1650 /* Expansion can recurse */
1651 #if ENABLE_HUSH_TICK
1652 static int process_command_subs(o_string *dest, struct in_str *input);
1654 static char *expand_string_to_string(const char *str);
1655 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end);
1657 /* expand_strvec_to_strvec() takes a list of strings, expands
1658 * all variable references within and returns a pointer to
1659 * a list of expanded strings, possibly with larger number
1660 * of strings. (Think VAR="a b"; echo $VAR).
1661 * This new list is allocated as a single malloc block.
1662 * NULL-terminated list of char* pointers is at the beginning of it,
1663 * followed by strings themself.
1664 * Caller can deallocate entire list by single free(list). */
1666 /* Store given string, finalizing the word and starting new one whenever
1667 * we encounter IFS char(s). This is used for expanding variable values.
1668 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1669 static int expand_on_ifs(o_string *output, int n, const char *str)
1672 int word_len = strcspn(str, G.ifs);
1674 if (output->o_escape || !output->o_glob)
1675 o_addQstr(output, str, word_len);
1676 else /* protect backslashes against globbing up :) */
1677 o_addstr_duplicate_backslash(output, str, word_len);
1680 if (!*str) /* EOL - do not finalize word */
1682 o_addchr(output, '\0');
1683 debug_print_list("expand_on_ifs", output, n);
1684 n = o_save_ptr(output, n);
1685 str += strspn(str, G.ifs); /* skip ifs chars */
1687 debug_print_list("expand_on_ifs[1]", output, n);
1691 /* Expand all variable references in given string, adding words to list[]
1692 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1693 * to be filled). This routine is extremely tricky: has to deal with
1694 * variables/parameters with whitespace, $* and $@, and constructs like
1695 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1696 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1698 /* or_mask is either 0 (normal case) or 0x80
1699 * (expansion of right-hand side of assignment == 1-element expand.
1700 * It will also do no globbing, and thus we must not backslash-quote!) */
1702 char first_ch, ored_ch;
1709 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1710 debug_print_list("expand_vars_to_list", output, n);
1711 n = o_save_ptr(output, n);
1712 debug_print_list("expand_vars_to_list[0]", output, n);
1714 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1715 #if ENABLE_HUSH_TICK
1716 o_string subst_result = NULL_O_STRING;
1718 #if ENABLE_SH_MATH_SUPPORT
1719 char arith_buf[sizeof(arith_t)*3 + 2];
1721 o_addstr(output, arg, p - arg);
1722 debug_print_list("expand_vars_to_list[1]", output, n);
1724 p = strchr(p, SPECIAL_VAR_SYMBOL);
1726 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1727 /* "$@" is special. Even if quoted, it can still
1728 * expand to nothing (not even an empty string) */
1729 if ((first_ch & 0x7f) != '@')
1730 ored_ch |= first_ch;
1733 switch (first_ch & 0x7f) {
1734 /* Highest bit in first_ch indicates that var is double-quoted */
1736 val = utoa(G.root_pid);
1738 case '!': /* bg pid */
1739 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1741 case '?': /* exitcode */
1742 val = utoa(G.last_return_code);
1744 case '#': /* argc */
1745 if (arg[1] != SPECIAL_VAR_SYMBOL)
1746 /* actually, it's a ${#var} */
1748 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1753 if (!G.global_argv[i])
1755 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1756 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1757 smallint sv = output->o_escape;
1758 /* unquoted var's contents should be globbed, so don't escape */
1759 output->o_escape = 0;
1760 while (G.global_argv[i]) {
1761 n = expand_on_ifs(output, n, G.global_argv[i]);
1762 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1763 if (G.global_argv[i++][0] && G.global_argv[i]) {
1764 /* this argv[] is not empty and not last:
1765 * put terminating NUL, start new word */
1766 o_addchr(output, '\0');
1767 debug_print_list("expand_vars_to_list[2]", output, n);
1768 n = o_save_ptr(output, n);
1769 debug_print_list("expand_vars_to_list[3]", output, n);
1772 output->o_escape = sv;
1774 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1775 * and in this case should treat it like '$*' - see 'else...' below */
1776 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1778 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1779 if (++i >= G.global_argc)
1781 o_addchr(output, '\0');
1782 debug_print_list("expand_vars_to_list[4]", output, n);
1783 n = o_save_ptr(output, n);
1785 } else { /* quoted $*: add as one word */
1787 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1788 if (!G.global_argv[++i])
1791 o_addchr(output, G.ifs[0]);
1795 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1796 /* "Empty variable", used to make "" etc to not disappear */
1800 #if ENABLE_HUSH_TICK
1801 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1802 struct in_str input;
1805 //TODO: can we just stuff it into "output" directly?
1806 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1807 setup_string_in_str(&input, arg);
1808 process_command_subs(&subst_result, &input);
1809 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1810 val = subst_result.data;
1814 #if ENABLE_SH_MATH_SUPPORT
1815 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1816 arith_eval_hooks_t hooks;
1821 arg++; /* skip '+' */
1822 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1823 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1825 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1828 unsigned char c = *exp_str++;
1835 if (strchr(" \t+-*/%_", c) != NULL)
1837 c |= 0x20; /* tolower */
1838 if (c >= 'a' && c <= 'z')
1842 /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
1844 struct in_str input;
1845 o_string dest = NULL_O_STRING;
1847 setup_string_in_str(&input, arg);
1848 parse_stream_dquoted(&dest, &input, EOF);
1849 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1850 exp_str = expand_string_to_string(dest.data);
1851 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1855 hooks.lookupvar = lookup_param;
1856 hooks.setvar = arith_set_local_var;
1857 hooks.endofname = endofname;
1858 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1863 case -3: maybe_die("arith", "exponent less than 0"); break;
1864 case -2: maybe_die("arith", "divide by zero"); break;
1865 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1866 default: maybe_die("arith", "syntax error"); break;
1869 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1870 sprintf(arith_buf, arith_t_fmt, res);
1875 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1877 bool exp_len = false, exp_null = false;
1878 char *var = arg, exp_save, exp_op, *exp_word;
1881 arg[0] = first_ch & 0x7f;
1883 /* prepare for expansions */
1884 if (var[0] == '#') {
1885 /* handle length expansion ${#var} */
1889 /* maybe handle parameter expansion */
1890 exp_off = strcspn(var, ":-=+?");
1894 exp_save = var[exp_off];
1895 exp_null = exp_save == ':';
1896 exp_word = var + exp_off;
1897 if (exp_null) ++exp_word;
1898 exp_op = *exp_word++;
1899 var[exp_off] = '\0';
1903 /* lookup the variable in question */
1904 if (isdigit(var[0])) {
1905 /* handle_dollar() should have vetted var for us */
1907 if (i < G.global_argc)
1908 val = G.global_argv[i];
1909 /* else val remains NULL: $N with too big N */
1911 val = lookup_param(var);
1913 /* handle any expansions */
1915 debug_printf_expand("expand: length of '%s' = ", val);
1916 val = utoa(val ? strlen(val) : 0);
1917 debug_printf_expand("%s\n", val);
1918 } else if (exp_off) {
1919 /* we need to do an expansion */
1920 int exp_test = (!val || (exp_null && !val[0]));
1922 exp_test = !exp_test;
1923 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1924 exp_null ? "true" : "false", exp_test);
1927 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1931 if (exp_op == '=') {
1932 if (isdigit(var[0]) || var[0] == '#') {
1933 maybe_die(var, "special vars cannot assign in this way");
1936 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1937 sprintf(new_var, "%s=%s", var, val);
1938 set_local_var(new_var, -1);
1942 var[exp_off] = exp_save;
1947 #if ENABLE_HUSH_TICK
1950 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1951 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1953 /* unquoted var's contents should be globbed, so don't escape */
1954 smallint sv = output->o_escape;
1955 output->o_escape = 0;
1956 n = expand_on_ifs(output, n, val);
1958 output->o_escape = sv;
1960 } else { /* quoted $VAR, val will be appended below */
1961 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1964 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1966 o_addQstr(output, val, strlen(val));
1968 /* Do the check to avoid writing to a const string */
1969 if (*p != SPECIAL_VAR_SYMBOL)
1970 *p = SPECIAL_VAR_SYMBOL;
1972 #if ENABLE_HUSH_TICK
1973 o_free(&subst_result);
1976 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1979 debug_print_list("expand_vars_to_list[a]", output, n);
1980 /* this part is literal, and it was already pre-quoted
1981 * if needed (much earlier), do not use o_addQstr here! */
1982 o_addstrauto(output, arg);
1983 debug_print_list("expand_vars_to_list[b]", output, n);
1984 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1985 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1988 /* allow to reuse list[n] later without re-growth */
1989 output->has_empty_slot = 1;
1991 o_addchr(output, '\0');
1996 static char **expand_variables(char **argv, int or_mask)
2001 o_string output = NULL_O_STRING;
2003 if (or_mask & 0x100) {
2004 output.o_escape = 1; /* protect against globbing for "$var" */
2005 /* (unquoted $var will temporarily switch it off) */
2012 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2015 debug_print_list("expand_variables", &output, n);
2017 /* output.data (malloced in one block) gets returned in "list" */
2018 list = o_finalize_list(&output, n);
2019 debug_print_strings("expand_variables[1]", list);
2023 static char **expand_strvec_to_strvec(char **argv)
2025 return expand_variables(argv, 0x100);
2028 /* Used for expansion of right hand of assignments */
2029 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2031 static char *expand_string_to_string(const char *str)
2033 char *argv[2], **list;
2035 argv[0] = (char*)str;
2037 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2039 if (!list[0] || list[1])
2040 bb_error_msg_and_die("BUG in varexp2");
2041 /* actually, just move string 2*sizeof(char*) bytes back */
2042 overlapping_strcpy((char*)list, list[0]);
2043 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2047 /* Used for "eval" builtin */
2048 static char* expand_strvec_to_string(char **argv)
2052 list = expand_variables(argv, 0x80);
2053 /* Convert all NULs to spaces */
2058 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2059 bb_error_msg_and_die("BUG in varexp3");
2060 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2064 overlapping_strcpy((char*)list, list[0]);
2065 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2069 static char **expand_assignments(char **argv, int count)
2073 /* Expand assignments into one string each */
2074 for (i = 0; i < count; i++) {
2075 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2081 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2082 * and stderr if they are redirected. */
2083 static int setup_redirects(struct command *prog, int squirrel[])
2086 struct redir_struct *redir;
2088 for (redir = prog->redirects; redir; redir = redir->next) {
2089 if (redir->dup == -1 && redir->rd_filename == NULL) {
2090 /* something went wrong in the parse. Pretend it didn't happen */
2093 if (redir->dup == -1) {
2095 mode = redir_table[redir->rd_type].mode;
2096 //TODO: check redir for names like '\\'
2097 p = expand_string_to_string(redir->rd_filename);
2098 openfd = open_or_warn(p, mode);
2101 /* this could get lost if stderr has been redirected, but
2102 bash and ash both lose it as well (though zsh doesn't!) */
2106 openfd = redir->dup;
2109 if (openfd != redir->fd) {
2110 if (squirrel && redir->fd < 3) {
2111 squirrel[redir->fd] = dup(redir->fd);
2114 //close(openfd); // close(-3) ??!
2116 dup2(openfd, redir->fd);
2117 if (redir->dup == -1)
2125 static void restore_redirects(int squirrel[])
2128 for (i = 0; i < 3; i++) {
2131 /* We simply die on error */
2138 #if !defined(DEBUG_CLEAN)
2139 #define free_pipe_list(head, indent) free_pipe_list(head)
2140 #define free_pipe(pi, indent) free_pipe(pi)
2142 static void free_pipe_list(struct pipe *head, int indent);
2144 /* return code is the exit status of the pipe */
2145 static void free_pipe(struct pipe *pi, int indent)
2148 struct command *command;
2149 struct redir_struct *r, *rnext;
2152 if (pi->stopped_cmds > 0)
2154 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2155 for (i = 0; i < pi->num_cmds; i++) {
2156 command = &pi->cmds[i];
2157 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2158 if (command->argv) {
2159 for (a = 0, p = command->argv; *p; a++, p++) {
2160 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2162 free_strings(command->argv);
2163 command->argv = NULL;
2165 /* not "else if": on syntax error, we may have both! */
2166 if (command->group) {
2167 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2168 free_pipe_list(command->group, indent+3);
2169 debug_printf_clean("%s end group\n", indenter(indent));
2170 command->group = NULL;
2172 for (r = command->redirects; r; r = rnext) {
2173 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2175 /* guard against the case >$FOO, where foo is unset or blank */
2176 if (r->rd_filename) {
2177 debug_printf_clean(" %s\n", r->rd_filename);
2178 free(r->rd_filename);
2179 r->rd_filename = NULL;
2182 debug_printf_clean("&%d\n", r->dup);
2187 command->redirects = NULL;
2189 free(pi->cmds); /* children are an array, they get freed all at once */
2197 static void free_pipe_list(struct pipe *head, int indent)
2199 struct pipe *pi, *next;
2201 for (pi = head; pi; pi = next) {
2203 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2205 free_pipe(pi, indent);
2206 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2208 /*pi->next = NULL;*/
2215 typedef struct nommu_save_t {
2221 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2222 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2223 #define pseudo_exec(nommu_save, command, argv_expanded) \
2224 pseudo_exec(command, argv_expanded)
2227 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2229 * XXX no exit() here. If you don't exec, use _exit instead.
2230 * The at_exit handlers apparently confuse the calling process,
2231 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2232 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2233 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2237 const struct built_in_command *x;
2239 /* If a variable is assigned in a forest, and nobody listens,
2240 * was it ever really set?
2242 if (!argv[assignment_cnt])
2243 _exit(EXIT_SUCCESS);
2245 new_env = expand_assignments(argv, assignment_cnt);
2247 putenv_all(new_env);
2248 free(new_env); /* optional */
2250 nommu_save->new_env = new_env;
2251 nommu_save->old_env = putenv_all_and_save_old(new_env);
2253 if (argv_expanded) {
2254 argv = argv_expanded;
2256 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2258 nommu_save->argv = argv;
2263 * Check if the command matches any of the builtins.
2264 * Depending on context, this might be redundant. But it's
2265 * easier to waste a few CPU cycles than it is to figure out
2266 * if this is one of those cases.
2268 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2269 if (strcmp(argv[0], x->cmd) == 0) {
2270 debug_printf_exec("running builtin '%s'\n", argv[0]);
2271 rcode = x->function(argv);
2277 /* Check if the command matches any busybox applets */
2278 #if ENABLE_FEATURE_SH_STANDALONE
2279 if (strchr(argv[0], '/') == NULL) {
2280 int a = find_applet_by_name(argv[0]);
2282 if (APPLET_IS_NOEXEC(a)) {
2283 debug_printf_exec("running applet '%s'\n", argv[0]);
2284 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2285 run_applet_no_and_exit(a, argv);
2287 /* re-exec ourselves with the new arguments */
2288 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2289 execvp(bb_busybox_exec_path, argv);
2290 /* If they called chroot or otherwise made the binary no longer
2291 * executable, fall through */
2296 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2298 debug_printf_exec("execing '%s'\n", argv[0]);
2299 execvp(argv[0], argv);
2300 bb_perror_msg("can't exec '%s'", argv[0]);
2301 _exit(EXIT_FAILURE);
2304 static int run_list(struct pipe *pi);
2306 /* Called after [v]fork() in run_pipe()
2308 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2309 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2312 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2314 if (command->group) {
2316 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2319 debug_printf_exec("pseudo_exec: run_list\n");
2320 rcode = run_list(command->group);
2321 /* OK to leak memory by not calling free_pipe_list,
2322 * since this process is about to exit */
2327 /* Can happen. See what bash does with ">foo" by itself. */
2328 debug_printf("trying to pseudo_exec null command\n");
2329 _exit(EXIT_SUCCESS);
2333 static const char *get_cmdtext(struct pipe *pi)
2339 /* This is subtle. ->cmdtext is created only on first backgrounding.
2340 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2341 * On subsequent bg argv is trashed, but we won't use it */
2344 argv = pi->cmds[0].argv;
2345 if (!argv || !argv[0]) {
2346 pi->cmdtext = xzalloc(1);
2351 do len += strlen(*argv) + 1; while (*++argv);
2352 pi->cmdtext = p = xmalloc(len);
2353 argv = pi->cmds[0].argv;
2355 len = strlen(*argv);
2356 memcpy(p, *argv, len);
2364 static void insert_bg_job(struct pipe *pi)
2366 struct pipe *thejob;
2369 /* Linear search for the ID of the job to use */
2371 for (thejob = G.job_list; thejob; thejob = thejob->next)
2372 if (thejob->jobid >= pi->jobid)
2373 pi->jobid = thejob->jobid + 1;
2375 /* Add thejob to the list of running jobs */
2377 thejob = G.job_list = xmalloc(sizeof(*thejob));
2379 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2381 thejob->next = xmalloc(sizeof(*thejob));
2382 thejob = thejob->next;
2385 /* Physically copy the struct job */
2386 memcpy(thejob, pi, sizeof(struct pipe));
2387 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2388 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2389 for (i = 0; i < pi->num_cmds; i++) {
2390 // TODO: do we really need to have so many fields which are just dead weight
2391 // at execution stage?
2392 thejob->cmds[i].pid = pi->cmds[i].pid;
2393 /* all other fields are not used and stay zero */
2395 thejob->next = NULL;
2396 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2398 /* We don't wait for background thejobs to return -- append it
2399 to the list of backgrounded thejobs and leave it alone */
2400 if (G_interactive_fd)
2401 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2402 G.last_bg_pid = thejob->cmds[0].pid;
2403 G.last_jobid = thejob->jobid;
2406 static void remove_bg_job(struct pipe *pi)
2408 struct pipe *prev_pipe;
2410 if (pi == G.job_list) {
2411 G.job_list = pi->next;
2413 prev_pipe = G.job_list;
2414 while (prev_pipe->next != pi)
2415 prev_pipe = prev_pipe->next;
2416 prev_pipe->next = pi->next;
2419 G.last_jobid = G.job_list->jobid;
2424 /* Remove a backgrounded job */
2425 static void delete_finished_bg_job(struct pipe *pi)
2428 pi->stopped_cmds = 0;
2434 /* Check to see if any processes have exited -- if they
2435 * have, figure out why and see if a job has completed */
2436 static int checkjobs(struct pipe* fg_pipe)
2446 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2449 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2450 // /* avoid doing syscall, nothing there anyway */
2453 attributes = WUNTRACED;
2454 if (fg_pipe == NULL)
2455 attributes |= WNOHANG;
2457 /* Do we do this right?
2458 * bash-3.00# sleep 20 | false
2460 * [3]+ Stopped sleep 20 | false
2461 * bash-3.00# echo $?
2462 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2465 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2466 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2467 // + killall -STOP cat
2474 // i = G.count_SIGCHLD;
2475 childpid = waitpid(-1, &status, attributes);
2476 if (childpid <= 0) {
2477 if (childpid && errno != ECHILD)
2478 bb_perror_msg("waitpid");
2479 // else /* Until next SIGCHLD, waitpid's are useless */
2480 // G.handled_SIGCHLD = i;
2483 dead = WIFEXITED(status) || WIFSIGNALED(status);
2486 if (WIFSTOPPED(status))
2487 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2488 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2489 if (WIFSIGNALED(status))
2490 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2491 childpid, WTERMSIG(status), WEXITSTATUS(status));
2492 if (WIFEXITED(status))
2493 debug_printf_jobs("pid %d exited, exitcode %d\n",
2494 childpid, WEXITSTATUS(status));
2496 /* Were we asked to wait for fg pipe? */
2498 for (i = 0; i < fg_pipe->num_cmds; i++) {
2499 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2500 if (fg_pipe->cmds[i].pid != childpid)
2502 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2504 fg_pipe->cmds[i].pid = 0;
2505 fg_pipe->alive_cmds--;
2506 if (i == fg_pipe->num_cmds - 1) {
2507 /* last process gives overall exitstatus */
2508 rcode = WEXITSTATUS(status);
2509 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2512 fg_pipe->cmds[i].is_stopped = 1;
2513 fg_pipe->stopped_cmds++;
2515 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2516 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2517 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2518 /* All processes in fg pipe have exited/stopped */
2520 if (fg_pipe->alive_cmds)
2521 insert_bg_job(fg_pipe);
2525 /* There are still running processes in the fg pipe */
2526 goto wait_more; /* do waitpid again */
2528 /* it wasnt fg_pipe, look for process in bg pipes */
2532 /* We asked to wait for bg or orphaned children */
2533 /* No need to remember exitcode in this case */
2534 for (pi = G.job_list; pi; pi = pi->next) {
2535 for (i = 0; i < pi->num_cmds; i++) {
2536 if (pi->cmds[i].pid == childpid)
2537 goto found_pi_and_prognum;
2540 /* Happens when shell is used as init process (init=/bin/sh) */
2541 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2542 continue; /* do waitpid again */
2544 found_pi_and_prognum:
2547 pi->cmds[i].pid = 0;
2549 if (!pi->alive_cmds) {
2550 if (G_interactive_fd)
2551 printf(JOB_STATUS_FORMAT, pi->jobid,
2552 "Done", pi->cmdtext);
2553 delete_finished_bg_job(pi);
2557 pi->cmds[i].is_stopped = 1;
2561 } /* while (waitpid succeeds)... */
2567 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2570 int rcode = checkjobs(fg_pipe);
2571 /* Job finished, move the shell to the foreground */
2572 p = getpgid(0); /* pgid of our process */
2573 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2574 tcsetpgrp(G_interactive_fd, p);
2579 /* run_pipe() starts all the jobs, but doesn't wait for anything
2580 * to finish. See checkjobs().
2582 * return code is normally -1, when the caller has to wait for children
2583 * to finish to determine the exit status of the pipe. If the pipe
2584 * is a simple builtin command, however, the action is done by the
2585 * time run_pipe returns, and the exit code is provided as the
2588 * The input of the pipe is always stdin, the output is always
2589 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2590 * because it tries to avoid running the command substitution in
2591 * subshell, when that is in fact necessary. The subshell process
2592 * now has its stdout directed to the input of the appropriate pipe,
2593 * so this routine is noticeably simpler.
2595 * Returns -1 only if started some children. IOW: we have to
2596 * mask out retvals of builtins etc with 0xff!
2598 static int run_pipe(struct pipe *pi)
2602 int pipefds[2]; /* pipefds[0] is for reading */
2603 struct command *command;
2604 char **argv_expanded;
2606 const struct built_in_command *x;
2608 /* it is not always needed, but we aim to smaller code */
2609 int squirrel[] = { -1, -1, -1 };
2611 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2613 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2619 pi->stopped_cmds = 0;
2621 /* Check if this is a simple builtin (not part of a pipe).
2622 * Builtins within pipes have to fork anyway, and are handled in
2623 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2625 command = &(pi->cmds[0]);
2627 #if ENABLE_HUSH_FUNCTIONS
2628 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2629 /* We "execute" function definition */
2630 bb_error_msg("here we ought to remember function definition, and go on");
2631 return EXIT_SUCCESS;
2635 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2636 debug_printf("non-subshell grouping\n");
2637 setup_redirects(command, squirrel);
2638 debug_printf_exec(": run_list\n");
2639 rcode = run_list(command->group) & 0xff;
2640 restore_redirects(squirrel);
2641 debug_printf_exec("run_pipe return %d\n", rcode);
2642 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2646 argv = command->argv;
2647 argv_expanded = NULL;
2649 if (single_and_fg && argv != NULL) {
2650 char **new_env = NULL;
2651 char **old_env = NULL;
2653 i = command->assignment_cnt;
2654 if (i != 0 && argv[i] == NULL) {
2655 /* assignments, but no command: set local environment */
2656 for (i = 0; argv[i] != NULL; i++) {
2657 debug_printf("local environment set: %s\n", argv[i]);
2658 p = expand_string_to_string(argv[i]);
2659 set_local_var(p, 0);
2661 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2664 /* Expand the rest into (possibly) many strings each */
2665 argv_expanded = expand_strvec_to_strvec(argv + i);
2667 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2668 if (strcmp(argv_expanded[0], x->cmd) != 0)
2670 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2671 debug_printf("exec with redirects only\n");
2672 setup_redirects(command, NULL);
2673 rcode = EXIT_SUCCESS;
2674 goto clean_up_and_ret1;
2676 debug_printf("builtin inline %s\n", argv_expanded[0]);
2677 /* XXX setup_redirects acts on file descriptors, not FILEs.
2678 * This is perfect for work that comes after exec().
2679 * Is it really safe for inline use? Experimentally,
2680 * things seem to work with glibc. */
2681 setup_redirects(command, squirrel);
2682 new_env = expand_assignments(argv, command->assignment_cnt);
2683 old_env = putenv_all_and_save_old(new_env);
2684 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2685 rcode = x->function(argv_expanded) & 0xff;
2686 #if ENABLE_FEATURE_SH_STANDALONE
2689 restore_redirects(squirrel);
2690 free_strings_and_unsetenv(new_env, 1);
2691 putenv_all(old_env);
2692 free(old_env); /* not free_strings()! */
2694 free(argv_expanded);
2695 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2696 debug_printf_exec("run_pipe return %d\n", rcode);
2699 #if ENABLE_FEATURE_SH_STANDALONE
2700 i = find_applet_by_name(argv_expanded[0]);
2701 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2702 setup_redirects(command, squirrel);
2703 save_nofork_data(&G.nofork_save);
2704 new_env = expand_assignments(argv, command->assignment_cnt);
2705 old_env = putenv_all_and_save_old(new_env);
2706 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2707 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2708 goto clean_up_and_ret;
2713 /* NB: argv_expanded may already be created, and that
2714 * might include `cmd` runs! Do not rerun it! We *must*
2715 * use argv_expanded if it's non-NULL */
2717 /* Going to fork a child per each pipe member */
2721 for (i = 0; i < pi->num_cmds; i++) {
2723 volatile nommu_save_t nommu_save;
2724 nommu_save.new_env = NULL;
2725 nommu_save.old_env = NULL;
2726 nommu_save.argv = NULL;
2728 command = &(pi->cmds[i]);
2729 if (command->argv) {
2730 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2732 debug_printf_exec(": pipe member with no argv\n");
2734 /* pipes are inserted between pairs of commands */
2737 if ((i + 1) < pi->num_cmds)
2740 command->pid = BB_MMU ? fork() : vfork();
2741 if (!command->pid) { /* child */
2743 die_sleep = 0; /* let nofork's xfuncs die */
2745 /* Every child adds itself to new process group
2746 * with pgid == pid_of_first_child_in_pipe */
2747 if (G.run_list_level == 1 && G_interactive_fd) {
2750 if (pgrp < 0) /* true for 1st process only */
2752 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2753 /* We do it in *every* child, not just first,
2755 tcsetpgrp(G_interactive_fd, pgrp);
2759 xmove_fd(nextin, 0);
2760 xmove_fd(pipefds[1], 1); /* write end */
2762 close(pipefds[0]); /* read end */
2763 /* Like bash, explicit redirects override pipes,
2764 * and the pipe fd is available for dup'ing. */
2765 setup_redirects(command, NULL);
2767 /* Restore default handlers just prior to exec */
2768 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2770 /* Stores to nommu_save list of env vars putenv'ed
2771 * (NOMMU, on MMU we don't need that) */
2772 /* cast away volatility... */
2773 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2774 /* pseudo_exec() does not return */
2778 /* Clean up after vforked child */
2779 free(nommu_save.argv);
2780 free_strings_and_unsetenv(nommu_save.new_env, 1);
2781 putenv_all(nommu_save.old_env);
2783 free(argv_expanded);
2784 argv_expanded = NULL;
2785 if (command->pid < 0) { /* [v]fork failed */
2786 /* Clearly indicate, was it fork or vfork */
2787 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2791 /* Second and next children need to know pid of first one */
2793 pi->pgrp = command->pid;
2799 if ((i + 1) < pi->num_cmds)
2800 close(pipefds[1]); /* write end */
2801 /* Pass read (output) pipe end to next iteration */
2802 nextin = pipefds[0];
2805 if (!pi->alive_cmds) {
2806 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2810 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2814 #ifndef debug_print_tree
2815 static void debug_print_tree(struct pipe *pi, int lvl)
2817 static const char *const PIPE[] = {
2823 static const char *RES[] = {
2824 [RES_NONE ] = "NONE" ,
2827 [RES_THEN ] = "THEN" ,
2828 [RES_ELIF ] = "ELIF" ,
2829 [RES_ELSE ] = "ELSE" ,
2832 #if ENABLE_HUSH_LOOPS
2833 [RES_FOR ] = "FOR" ,
2834 [RES_WHILE] = "WHILE",
2835 [RES_UNTIL] = "UNTIL",
2837 [RES_DONE ] = "DONE" ,
2839 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2842 #if ENABLE_HUSH_CASE
2843 [RES_CASE ] = "CASE" ,
2844 [RES_MATCH] = "MATCH",
2845 [RES_CASEI] = "CASEI",
2846 [RES_ESAC ] = "ESAC" ,
2848 [RES_XXXX ] = "XXXX" ,
2849 [RES_SNTX ] = "SNTX" ,
2851 static const char *const GRPTYPE[] = {
2854 #if ENABLE_HUSH_FUNCTIONS
2863 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2864 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2866 while (prn < pi->num_cmds) {
2867 struct command *command = &pi->cmds[prn];
2868 char **argv = command->argv;
2870 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2871 if (command->group) {
2872 fprintf(stderr, " group %s: (argv=%p)\n",
2873 GRPTYPE[command->grp_type],
2875 debug_print_tree(command->group, lvl+1);
2879 if (argv) while (*argv) {
2880 fprintf(stderr, " '%s'", *argv);
2883 fprintf(stderr, "\n");
2892 /* NB: called by pseudo_exec, and therefore must not modify any
2893 * global data until exec/_exit (we can be a child after vfork!) */
2894 static int run_list(struct pipe *pi)
2896 #if ENABLE_HUSH_CASE
2897 char *case_word = NULL;
2899 #if ENABLE_HUSH_LOOPS
2900 struct pipe *loop_top = NULL;
2901 char *for_varname = NULL;
2902 char **for_lcur = NULL;
2903 char **for_list = NULL;
2905 smallint flag_skip = 1;
2906 smalluint rcode = 0; /* probably just for compiler */
2907 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2908 smalluint cond_code = 0;
2910 enum { cond_code = 0, };
2912 /*enum reserved_style*/ smallint rword = RES_NONE;
2913 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2915 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2917 #if ENABLE_HUSH_LOOPS
2918 /* Check syntax for "for" */
2919 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2920 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2922 /* current word is FOR or IN (BOLD in comments below) */
2923 if (cpipe->next == NULL) {
2924 syntax("malformed for");
2925 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2928 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2929 if (cpipe->next->res_word == RES_DO)
2931 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2932 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2933 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2935 syntax("malformed for");
2936 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2942 /* Past this point, all code paths should jump to ret: label
2943 * in order to return, no direct "return" statements please.
2944 * This helps to ensure that no memory is leaked. */
2946 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2949 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2950 * We are saving state before entering outermost list ("while...done")
2951 * so that ctrl-Z will correctly background _entire_ outermost list,
2952 * not just a part of it (like "sleep 1 | exit 2") */
2953 if (++G.run_list_level == 1 && G_interactive_fd) {
2954 if (sigsetjmp(G.toplevel_jb, 1)) {
2955 /* ctrl-Z forked and we are parent; or ctrl-C.
2956 * Sighandler has longjmped us here */
2957 signal(SIGINT, SIG_IGN);
2958 signal(SIGTSTP, SIG_IGN);
2959 /* Restore level (we can be coming from deep inside
2961 G.run_list_level = 1;
2962 #if ENABLE_FEATURE_SH_STANDALONE
2963 if (G.nofork_save.saved) { /* if save area is valid */
2964 debug_printf_jobs("exiting nofork early\n");
2965 restore_nofork_data(&G.nofork_save);
2968 //// if (G.ctrl_z_flag) {
2969 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2970 //// * Remember this child as background job */
2971 //// insert_bg_job(pi);
2973 /* ctrl-C. We just stop doing whatever we were doing */
2976 USE_HUSH_LOOPS(loop_top = NULL;)
2977 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2981 //// /* ctrl-Z handler will store pid etc in pi */
2982 //// G.toplevel_list = pi;
2983 //// G.ctrl_z_flag = 0;
2984 ////#if ENABLE_FEATURE_SH_STANDALONE
2985 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2987 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2988 //// signal(SIGINT, handler_ctrl_c);
2992 /* Go through list of pipes, (maybe) executing them. */
2993 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2997 IF_HAS_KEYWORDS(rword = pi->res_word;)
2998 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2999 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
3000 rword, cond_code, skip_more_for_this_rword);
3001 #if ENABLE_HUSH_LOOPS
3002 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3003 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3005 /* start of a loop: remember where loop starts */
3010 if (rword == skip_more_for_this_rword && flag_skip) {
3011 if (pi->followup == PIPE_SEQ)
3013 /* it is "<false> && CMD" or "<true> || CMD"
3014 * and we should not execute CMD */
3018 skip_more_for_this_rword = RES_XXXX;
3021 if (rword == RES_THEN) {
3022 /* "if <false> THEN cmd": skip cmd */
3026 if (rword == RES_ELSE || rword == RES_ELIF) {
3027 /* "if <true> then ... ELSE/ELIF cmd":
3028 * skip cmd and all following ones */
3033 #if ENABLE_HUSH_LOOPS
3034 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3036 /* first loop through for */
3038 static const char encoded_dollar_at[] ALIGN1 = {
3039 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3040 }; /* encoded representation of "$@" */
3041 static const char *const encoded_dollar_at_argv[] = {
3042 encoded_dollar_at, NULL
3043 }; /* argv list with one element: "$@" */
3046 vals = (char**)encoded_dollar_at_argv;
3047 if (pi->next->res_word == RES_IN) {
3048 /* if no variable values after "in" we skip "for" */
3049 if (!pi->next->cmds[0].argv)
3051 vals = pi->next->cmds[0].argv;
3052 } /* else: "for var; do..." -> assume "$@" list */
3053 /* create list of variable values */
3054 debug_print_strings("for_list made from", vals);
3055 for_list = expand_strvec_to_strvec(vals);
3056 for_lcur = for_list;
3057 debug_print_strings("for_list", for_list);
3058 for_varname = pi->cmds[0].argv[0];
3059 pi->cmds[0].argv[0] = NULL;
3061 free(pi->cmds[0].argv[0]);
3063 /* "for" loop is over, clean up */
3067 pi->cmds[0].argv[0] = for_varname;
3070 /* insert next value from for_lcur */
3071 //TODO: does it need escaping?
3072 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3073 pi->cmds[0].assignment_cnt = 1;
3075 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
3077 if (rword == RES_DONE) {
3078 continue; /* "done" has no cmds too */
3081 #if ENABLE_HUSH_CASE
3082 if (rword == RES_CASE) {
3083 case_word = expand_strvec_to_string(pi->cmds->argv);
3086 if (rword == RES_MATCH) {
3089 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3091 /* all prev words didn't match, does this one match? */
3092 argv = pi->cmds->argv;
3094 char *pattern = expand_string_to_string(*argv);
3095 /* TODO: which FNM_xxx flags to use? */
3096 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3098 if (cond_code == 0) { /* match! we will execute this branch */
3099 free(case_word); /* make future "word)" stop */
3107 if (rword == RES_CASEI) { /* inside of a case branch */
3109 continue; /* not matched yet, skip this pipe */
3112 /* Just pressing <enter> in shell should check for jobs.
3113 * OTOH, in non-interactive shell this is useless
3114 * and only leads to extra job checks */
3115 if (pi->num_cmds == 0) {
3116 if (G_interactive_fd)
3117 goto check_jobs_and_continue;
3121 /* After analyzing all keywords and conditions, we decided
3122 * to execute this pipe. NB: have to do checkjobs(NULL)
3123 * after run_pipe() to collect any background children,
3124 * even if list execution is to be stopped. */
3125 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3128 #if ENABLE_HUSH_LOOPS
3129 G.flag_break_continue = 0;
3131 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3133 /* we only ran a builtin: rcode is already known
3134 * and we don't need to wait for anything. */
3135 check_and_run_traps(0);
3136 #if ENABLE_HUSH_LOOPS
3137 /* was it "break" or "continue"? */
3138 if (G.flag_break_continue) {
3139 smallint fbc = G.flag_break_continue;
3140 /* we might fall into outer *loop*,
3141 * don't want to break it too */
3143 G.depth_break_continue--;
3144 if (G.depth_break_continue == 0)
3145 G.flag_break_continue = 0;
3146 /* else: e.g. "continue 2" should *break* once, *then* continue */
3147 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3148 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3149 goto check_jobs_and_break;
3150 /* "continue": simulate end of loop */
3155 } else if (pi->followup == PIPE_BG) {
3156 /* what does bash do with attempts to background builtins? */
3157 /* even bash 3.2 doesn't do that well with nested bg:
3158 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3159 * I'm NOT treating inner &'s as jobs */
3160 check_and_run_traps(0);
3162 if (G.run_list_level == 1)
3165 rcode = 0; /* EXIT_SUCCESS */
3168 if (G.run_list_level == 1 && G_interactive_fd) {
3169 /* waits for completion, then fg's main shell */
3170 rcode = checkjobs_and_fg_shell(pi);
3171 check_and_run_traps(0);
3172 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3175 { /* this one just waits for completion */
3176 rcode = checkjobs(pi);
3177 check_and_run_traps(0);
3178 debug_printf_exec(": checkjobs returned %d\n", rcode);
3182 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3183 G.last_return_code = rcode;
3185 /* Analyze how result affects subsequent commands */
3187 if (rword == RES_IF || rword == RES_ELIF)
3190 #if ENABLE_HUSH_LOOPS
3191 if (rword == RES_WHILE) {
3193 rcode = 0; /* "while false; do...done" - exitcode 0 */
3194 goto check_jobs_and_break;
3197 if (rword == RES_UNTIL) {
3199 check_jobs_and_break:
3205 if ((rcode == 0 && pi->followup == PIPE_OR)
3206 || (rcode != 0 && pi->followup == PIPE_AND)
3208 skip_more_for_this_rword = rword;
3211 check_jobs_and_continue:
3216 //// if (G.ctrl_z_flag) {
3217 //// /* ctrl-Z forked somewhere in the past, we are the child,
3218 //// * and now we completed running the list. Exit. */
3224 //// if (!G.run_list_level && G_interactive_fd) {
3225 //// signal(SIGTSTP, SIG_IGN);
3226 //// signal(SIGINT, SIG_IGN);
3229 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3230 #if ENABLE_HUSH_LOOPS
3235 #if ENABLE_HUSH_CASE
3241 /* Select which version we will use */
3242 static int run_and_free_list(struct pipe *pi)
3245 debug_printf_exec("run_and_free_list entered\n");
3247 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3248 rcode = run_list(pi);
3250 /* free_pipe_list has the side effect of clearing memory.
3251 * In the long run that function can be merged with run_list,
3252 * but doing that now would hobble the debugging effort. */
3253 free_pipe_list(pi, /* indent: */ 0);
3254 debug_printf_exec("run_and_free_list return %d\n", rcode);
3259 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3260 * as in "2>&1", that represents duplicating a file descriptor.
3261 * Return either -2 (syntax error), -1 (no &), or the number found.
3263 static int redirect_dup_num(struct in_str *input)
3265 int ch, d = 0, ok = 0;
3267 if (ch != '&') return -1;
3269 i_getch(input); /* get the & */
3273 return -3; /* "-" represents "close me" */
3275 while (isdigit(ch)) {
3276 d = d*10 + (ch-'0');
3283 bb_error_msg("ambiguous redirect");
3287 /* The src parameter allows us to peek forward to a possible &n syntax
3288 * for file descriptor duplication, e.g., "2>&1".
3289 * Return code is 0 normally, 1 if a syntax error is detected in src.
3290 * Resource errors (in xmalloc) cause the process to exit */
3291 static int setup_redirect(struct parse_context *ctx,
3294 struct in_str *input)
3296 struct command *command = ctx->command;
3297 struct redir_struct *redir;
3298 struct redir_struct **redirp;
3301 /* Check for a '2>&1' type redirect */
3302 dup_num = redirect_dup_num(input);
3304 return 1; /* syntax error */
3306 /* Create a new redir_struct and drop it onto the end of the linked list */
3307 redirp = &command->redirects;
3308 while ((redir = *redirp) != NULL) {
3309 redirp = &(redir->next);
3311 *redirp = redir = xzalloc(sizeof(*redir));
3312 /* redir->next = NULL; */
3313 /* redir->rd_filename = NULL; */
3314 redir->rd_type = style;
3315 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3317 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3319 redir->dup = dup_num;
3320 if (dup_num != -1) {
3321 /* Erik had a check here that the file descriptor in question
3322 * is legit; I postpone that to "run time"
3323 * A "-" representation of "close me" shows up as a -3 here */
3324 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3326 /* We do _not_ try to open the file that src points to,
3327 * since we need to return and let src be expanded first.
3328 * Set ctx->pending_redirect, so we know what to do at the
3329 * end of the next parsed word. */
3330 ctx->pending_redirect = redir;
3336 static struct pipe *new_pipe(void)
3339 pi = xzalloc(sizeof(struct pipe));
3340 /*pi->followup = 0; - deliberately invalid value */
3341 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3345 /* Command (member of a pipe) is complete. The only possible error here
3346 * is out of memory, in which case xmalloc exits. */
3347 static int done_command(struct parse_context *ctx)
3349 /* The command is really already in the pipe structure, so
3350 * advance the pipe counter and make a new, null command. */
3351 struct pipe *pi = ctx->pipe;
3352 struct command *command = ctx->command;
3355 if (command->group == NULL
3356 && command->argv == NULL
3357 && command->redirects == NULL
3359 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3360 return pi->num_cmds;
3363 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3365 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3368 /* Only real trickiness here is that the uncommitted
3369 * command structure is not counted in pi->num_cmds. */
3370 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3371 command = &pi->cmds[pi->num_cmds];
3372 memset(command, 0, sizeof(*command));
3374 ctx->command = command;
3375 /* but ctx->pipe and ctx->list_head remain unchanged */
3377 return pi->num_cmds; /* used only for 0/nonzero check */
3380 static void done_pipe(struct parse_context *ctx, pipe_style type)
3384 debug_printf_parse("done_pipe entered, followup %d\n", type);
3385 /* Close previous command */
3386 not_null = done_command(ctx);
3387 ctx->pipe->followup = type;
3388 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3389 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3390 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3392 /* Without this check, even just <enter> on command line generates
3393 * tree of three NOPs (!). Which is harmless but annoying.
3394 * IOW: it is safe to do it unconditionally.
3395 * RES_NONE case is for "for a in; do ..." (empty IN set)
3396 * to work, possibly other cases too. */
3397 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3399 debug_printf_parse("done_pipe: adding new pipe: "
3400 "not_null:%d ctx->ctx_res_w:%d\n",
3401 not_null, ctx->ctx_res_w);
3403 ctx->pipe->next = new_p;
3405 /* RES_THEN, RES_DO etc are "sticky" -
3406 * they remain set for commands inside if/while.
3407 * This is used to control execution.
3408 * RES_FOR and RES_IN are NOT sticky (needed to support
3409 * cases where variable or value happens to match a keyword):
3411 #if ENABLE_HUSH_LOOPS
3412 if (ctx->ctx_res_w == RES_FOR
3413 || ctx->ctx_res_w == RES_IN)
3414 ctx->ctx_res_w = RES_NONE;
3416 #if ENABLE_HUSH_CASE
3417 if (ctx->ctx_res_w == RES_MATCH)
3418 ctx->ctx_res_w = RES_CASEI;
3420 ctx->command = NULL; /* trick done_command below */
3421 /* Create the memory for command, roughly:
3422 * ctx->pipe->cmds = new struct command;
3423 * ctx->command = &ctx->pipe->cmds[0];
3427 debug_printf_parse("done_pipe return\n");
3430 static void initialize_context(struct parse_context *ctx)
3432 memset(ctx, 0, sizeof(*ctx));
3433 ctx->pipe = ctx->list_head = new_pipe();
3434 /* Create the memory for command, roughly:
3435 * ctx->pipe->cmds = new struct command;
3436 * ctx->command = &ctx->pipe->cmds[0];
3442 /* If a reserved word is found and processed, parse context is modified
3443 * and 1 is returned.
3446 struct reserved_combo {
3449 unsigned char assignment_flag;
3453 FLAG_END = (1 << RES_NONE ),
3455 FLAG_IF = (1 << RES_IF ),
3456 FLAG_THEN = (1 << RES_THEN ),
3457 FLAG_ELIF = (1 << RES_ELIF ),
3458 FLAG_ELSE = (1 << RES_ELSE ),
3459 FLAG_FI = (1 << RES_FI ),
3461 #if ENABLE_HUSH_LOOPS
3462 FLAG_FOR = (1 << RES_FOR ),
3463 FLAG_WHILE = (1 << RES_WHILE),
3464 FLAG_UNTIL = (1 << RES_UNTIL),
3465 FLAG_DO = (1 << RES_DO ),
3466 FLAG_DONE = (1 << RES_DONE ),
3467 FLAG_IN = (1 << RES_IN ),
3469 #if ENABLE_HUSH_CASE
3470 FLAG_MATCH = (1 << RES_MATCH),
3471 FLAG_ESAC = (1 << RES_ESAC ),
3473 FLAG_START = (1 << RES_XXXX ),
3476 static const struct reserved_combo* match_reserved_word(o_string *word)
3478 /* Mostly a list of accepted follow-up reserved words.
3479 * FLAG_END means we are done with the sequence, and are ready
3480 * to turn the compound list into a command.
3481 * FLAG_START means the word must start a new compound list.
3483 static const struct reserved_combo reserved_list[] = {
3485 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3486 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3487 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3488 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3489 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3490 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3492 #if ENABLE_HUSH_LOOPS
3493 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3494 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3495 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3496 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3497 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3498 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3500 #if ENABLE_HUSH_CASE
3501 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3502 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3505 const struct reserved_combo *r;
3507 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3508 if (strcmp(word->data, r->literal) == 0)
3513 static int reserved_word(o_string *word, struct parse_context *ctx)
3515 #if ENABLE_HUSH_CASE
3516 static const struct reserved_combo reserved_match = {
3517 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3520 const struct reserved_combo *r;
3522 r = match_reserved_word(word);
3526 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3527 #if ENABLE_HUSH_CASE
3528 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3529 /* "case word IN ..." - IN part starts first match part */
3530 r = &reserved_match;
3533 if (r->flag == 0) { /* '!' */
3534 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3535 syntax("! ! command");
3536 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3538 ctx->ctx_inverted = 1;
3541 if (r->flag & FLAG_START) {
3542 struct parse_context *old;
3543 old = xmalloc(sizeof(*old));
3544 debug_printf_parse("push stack %p\n", old);
3545 *old = *ctx; /* physical copy */
3546 initialize_context(ctx);
3548 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3550 ctx->ctx_res_w = RES_SNTX;
3553 ctx->ctx_res_w = r->res;
3554 ctx->old_flag = r->flag;
3555 if (ctx->old_flag & FLAG_END) {
3556 struct parse_context *old;
3557 done_pipe(ctx, PIPE_SEQ);
3558 debug_printf_parse("pop stack %p\n", ctx->stack);
3560 old->command->group = ctx->list_head;
3561 old->command->grp_type = GRP_NORMAL;
3562 *ctx = *old; /* physical copy */
3565 word->o_assignment = r->assignment_flag;
3570 /* Word is complete, look at it and update parsing context.
3571 * Normal return is 0. Syntax errors return 1.
3572 * Note: on return, word is reset, but not o_free'd!
3574 static int done_word(o_string *word, struct parse_context *ctx)
3576 struct command *command = ctx->command;
3578 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3579 if (word->length == 0 && word->nonnull == 0) {
3580 debug_printf_parse("done_word return 0: true null, ignored\n");
3583 /* If this word wasn't an assignment, next ones definitely
3584 * can't be assignments. Even if they look like ones. */
3585 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3586 && word->o_assignment != WORD_IS_KEYWORD
3588 word->o_assignment = NOT_ASSIGNMENT;
3590 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3591 command->assignment_cnt++;
3592 word->o_assignment = MAYBE_ASSIGNMENT;
3595 if (ctx->pending_redirect) {
3596 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3597 * only if run as "bash", not "sh" */
3598 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3599 word->o_assignment = NOT_ASSIGNMENT;
3600 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3602 /* "{ echo foo; } echo bar" - bad */
3603 /* NB: bash allows e.g.:
3604 * if true; then { echo foo; } fi
3605 * while if false; then false; fi do break; done
3607 if (command->group) {
3609 debug_printf_parse("done_word return 1: syntax error, "
3610 "groups and arglists don't mix\n");
3614 #if ENABLE_HUSH_CASE
3615 if (ctx->ctx_dsemicolon
3616 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3618 /* already done when ctx_dsemicolon was set to 1: */
3619 /* ctx->ctx_res_w = RES_MATCH; */
3620 ctx->ctx_dsemicolon = 0;
3623 if (!command->argv /* if it's the first word... */
3624 #if ENABLE_HUSH_LOOPS
3625 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3626 && ctx->ctx_res_w != RES_IN
3629 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3630 if (reserved_word(word, ctx)) {
3632 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3633 return (ctx->ctx_res_w == RES_SNTX);
3637 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3638 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3639 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3640 /* (otherwise it's known to be not empty and is already safe) */
3642 /* exclude "$@" - it can expand to no word despite "" */
3643 char *p = word->data;
3644 while (p[0] == SPECIAL_VAR_SYMBOL
3645 && (p[1] & 0x7f) == '@'
3646 && p[2] == SPECIAL_VAR_SYMBOL
3650 if (p == word->data || p[0] != '\0') {
3651 /* saw no "$@", or not only "$@" but some
3652 * real text is there too */
3653 /* insert "empty variable" reference, this makes
3654 * e.g. "", $empty"" etc to not disappear */
3655 o_addchr(word, SPECIAL_VAR_SYMBOL);
3656 o_addchr(word, SPECIAL_VAR_SYMBOL);
3659 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3660 debug_print_strings("word appended to argv", command->argv);
3664 ctx->pending_redirect = NULL;
3666 #if ENABLE_HUSH_LOOPS
3667 /* Force FOR to have just one word (variable name) */
3668 /* NB: basically, this makes hush see "for v in ..." syntax as if
3669 * as it is "for v; in ...". FOR and IN become two pipe structs
3671 if (ctx->ctx_res_w == RES_FOR) {
3672 //TODO: check that command->argv[0] is a valid variable name!
3673 done_pipe(ctx, PIPE_SEQ);
3676 #if ENABLE_HUSH_CASE
3677 /* Force CASE to have just one word */
3678 if (ctx->ctx_res_w == RES_CASE) {
3679 done_pipe(ctx, PIPE_SEQ);
3682 debug_printf_parse("done_word return 0\n");
3686 /* If a redirect is immediately preceded by a number, that number is
3687 * supposed to tell which file descriptor to redirect. This routine
3688 * looks for such preceding numbers. In an ideal world this routine
3689 * needs to handle all the following classes of redirects...
3690 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3691 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3692 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3693 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3694 * A -1 output from this program means no valid number was found, so the
3695 * caller should use the appropriate default for this redirection.
3697 static int redirect_opt_num(o_string *o)
3703 for (num = 0; num < o->length; num++) {
3704 if (!isdigit(o->data[num])) {
3708 num = atoi(o->data);
3713 static struct pipe *parse_stream(struct in_str *input, int end_trigger);
3715 #if ENABLE_HUSH_TICK
3716 static FILE *generate_stream_from_list(struct pipe *head)
3719 int pid, channel[2];
3722 /* *** NOMMU WARNING *** */
3723 /* By using vfork here, we suspend parent till child exits or execs.
3724 * If child will not do it before it fills the pipe, it can block forever
3725 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3727 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3728 * huge=`cat TESTFILE` # will block here forever
3731 pid = BB_MMU ? fork() : vfork();
3733 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3734 if (pid == 0) { /* child */
3735 if (ENABLE_HUSH_JOB)
3736 die_sleep = 0; /* let nofork's xfuncs die */
3737 close(channel[0]); /* NB: close _first_, then move fd! */
3738 xmove_fd(channel[1], 1);
3739 /* Prevent it from trying to handle ctrl-z etc */
3741 G.run_list_level = 1;
3743 /* Process substitution is not considered to be usual
3744 * 'command execution'.
3745 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3753 /* Note: freeing 'head' here would break NOMMU. */
3754 _exit(run_list(head));
3757 pf = fdopen(channel[0], "r");
3759 /* 'head' is freed by the caller */
3762 /* Return code is exit status of the process that is run. */
3763 static int process_command_subs(o_string *dest,
3764 struct in_str *input)
3766 int retcode, ch, eol_cnt;
3767 struct pipe *pipe_list;
3769 struct in_str pipe_str;
3771 /* Recursion to generate command */
3772 pipe_list = parse_stream(input, '\0');
3773 if (pipe_list == NULL)
3774 return 0; /* EOF: empty `cmd`: ``, ` ` etc */
3775 if (pipe_list == ERR_PTR)
3776 return 1; /* parse error. can this really happen? */
3778 p = generate_stream_from_list(pipe_list);
3779 free_pipe_list(pipe_list, /* indent: */ 0);
3782 close_on_exec_on(fileno(p));
3784 /* Now send results of command back into original context */
3785 setup_file_in_str(&pipe_str, p);
3787 while ((ch = i_getch(&pipe_str)) != EOF) {
3793 o_addchr(dest, '\n');
3796 o_addQchr(dest, ch);
3799 debug_printf("done reading from pipe, pclose()ing\n");
3800 /* Note: we got EOF, and we just close the read end of the pipe.
3801 * We do not wait for the `cmd` child to terminate. bash and ash do.
3803 * echo `echo Hi; exec 1>&-; sleep 2`
3805 retcode = fclose(p);
3806 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3811 static int parse_group(o_string *dest, struct parse_context *ctx,
3812 struct in_str *input, int ch)
3814 /* dest contains characters seen prior to ( or {.
3815 * Typically it's empty, but for function defs,
3816 * it contains function name (without '()'). */
3817 struct pipe *pipe_list;
3819 struct command *command = ctx->command;
3821 debug_printf_parse("parse_group entered\n");
3822 #if ENABLE_HUSH_FUNCTIONS
3823 if (ch == 'F') { /* function definition? */
3824 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3825 //command->fname = dest->data;
3826 command->grp_type = GRP_FUNCTION;
3827 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3828 memset(dest, 0, sizeof(*dest));
3831 if (command->argv /* word [word](... */
3832 || dest->length /* word(... */
3833 || dest->nonnull /* ""(... */
3836 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3842 command->grp_type = GRP_SUBSHELL;
3844 pipe_list = parse_stream(input, endch);
3845 /* empty ()/{} or parse error? */
3846 if (!pipe_list || pipe_list == ERR_PTR) {
3848 debug_printf_parse("parse_group return 1: parse_stream returned %p\n", pipe_list);
3851 command->group = pipe_list;
3852 debug_printf_parse("parse_group return 0\n");
3854 /* command remains "open", available for possible redirects */
3857 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
3858 /* Subroutines for copying $(...) and `...` things */
3859 static void add_till_backquote(o_string *dest, struct in_str *input);
3861 static void add_till_single_quote(o_string *dest, struct in_str *input)
3864 int ch = i_getch(input);
3872 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3873 static void add_till_double_quote(o_string *dest, struct in_str *input)
3876 int ch = i_getch(input);
3879 if (ch == '\\') { /* \x. Copy both chars. */
3881 ch = i_getch(input);
3887 add_till_backquote(dest, input);
3891 //if (ch == '$') ...
3894 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3896 * "Within the backquoted style of command substitution, backslash
3897 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3898 * The search for the matching backquote shall be satisfied by the first
3899 * backquote found without a preceding backslash; during this search,
3900 * if a non-escaped backquote is encountered within a shell comment,
3901 * a here-document, an embedded command substitution of the $(command)
3902 * form, or a quoted string, undefined results occur. A single-quoted
3903 * or double-quoted string that begins, but does not end, within the
3904 * "`...`" sequence produces undefined results."
3906 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3908 static void add_till_backquote(o_string *dest, struct in_str *input)
3911 int ch = i_getch(input);
3914 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3915 int ch2 = i_getch(input);
3916 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3925 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3926 * quoting and nested ()s.
3927 * "With the $(command) style of command substitution, all characters
3928 * following the open parenthesis to the matching closing parenthesis
3929 * constitute the command. Any valid shell script can be used for command,
3930 * except a script consisting solely of redirections which produces
3931 * unspecified results."
3933 * echo $(echo '(TEST)' BEST) (TEST) BEST
3934 * echo $(echo 'TEST)' BEST) TEST) BEST
3935 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3937 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
3941 int ch = i_getch(input);
3950 if (i_peek(input) == ')') {
3957 add_till_single_quote(dest, input);
3962 add_till_double_quote(dest, input);
3966 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3967 ch = i_getch(input);
3975 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
3977 /* Return code: 0 for OK, 1 for syntax error */
3978 static int handle_dollar(o_string *dest, struct in_str *input)
3981 int ch = i_peek(input); /* first character after the $ */
3982 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
3984 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3988 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3990 debug_printf_parse(": '%c'\n", ch);
3991 o_addchr(dest, ch | quote_mask);
3994 if (!isalnum(ch) && ch != '_')
3998 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3999 } else if (isdigit(ch)) {
4002 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4003 debug_printf_parse(": '%c'\n", ch);
4004 o_addchr(dest, ch | quote_mask);
4005 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4006 } else switch (ch) {
4008 case '!': /* last bg pid */
4009 case '?': /* last exit code */
4010 case '#': /* number of args */
4011 case '*': /* args */
4012 case '@': /* args */
4013 goto make_one_char_var;
4015 bool first_char, all_digits;
4017 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4019 /* XXX maybe someone will try to escape the '}' */
4024 ch = i_getch(input);
4030 /* ${#var}: length of var contents */
4032 else if (isdigit(ch)) {
4038 if (expansion < 2 &&
4039 ((all_digits && !isdigit(ch)) ||
4040 (!all_digits && !isalnum(ch) && ch != '_')))
4042 /* handle parameter expansions
4043 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4048 case ':': /* null modifier */
4049 if (expansion == 0) {
4050 debug_printf_parse(": null modifier\n");
4056 #if 0 /* not implemented yet :( */
4057 case '#': /* remove prefix */
4058 case '%': /* remove suffix */
4059 if (expansion == 0) {
4060 debug_printf_parse(": remove suffix/prefix\n");
4067 case '-': /* default value */
4068 case '=': /* assign default */
4069 case '+': /* alternative */
4070 case '?': /* error indicate */
4071 debug_printf_parse(": parameter expansion\n");
4077 syntax("unterminated ${name}");
4078 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4084 debug_printf_parse(": '%c'\n", ch);
4085 o_addchr(dest, ch | quote_mask);
4089 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4095 #if ENABLE_SH_MATH_SUPPORT
4096 if (i_peek(input) == '(') {
4098 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4099 o_addchr(dest, /*quote_mask |*/ '+');
4100 add_till_closing_paren(dest, input, true);
4101 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4106 #if ENABLE_HUSH_TICK
4107 //int pos = dest->length;
4108 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4109 o_addchr(dest, quote_mask | '`');
4110 add_till_closing_paren(dest, input, false);
4111 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4112 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4119 if (isalnum(ch)) { /* it's $_name or $_123 */
4125 /* still unhandled, but should be eventually */
4126 bb_error_msg("unhandled syntax: $%c", ch);
4130 o_addQchr(dest, '$');
4132 debug_printf_parse("handle_dollar return 0\n");
4136 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end)
4142 ch = i_getch(input);
4143 if (ch == dquote_end) { /* may be only '"' or EOF */
4145 if (dest->o_assignment == NOT_ASSIGNMENT)
4146 dest->o_escape ^= 1;
4147 debug_printf_parse("parse_stream_dquoted return 0\n");
4151 syntax("unterminated \"");
4152 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4158 next = i_peek(input);
4160 debug_printf_parse(": ch=%c (%d) m=%d escape=%d\n",
4161 ch, ch, m, dest->o_escape);
4162 /* Basically, checking every CHAR_SPECIAL char except '"' */
4166 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4170 * "The backslash retains its special meaning [in "..."]
4171 * only when followed by one of the following characters:
4172 * $, `, ", \, or <newline>. A double quote may be quoted
4173 * within double quotes by preceding it with a backslash.
4174 * If enabled, history expansion will be performed unless
4175 * an ! appearing in double quotes is escaped using
4176 * a backslash. The backslash preceding the ! is not removed."
4178 if (strchr("$`\"\\", next) != NULL) {
4179 o_addqchr(dest, i_getch(input));
4181 o_addqchr(dest, '\\');
4186 if (handle_dollar(dest, input) != 0) {
4187 debug_printf_parse("parse_stream_dquoted return 1: handle_dollar returned non-0\n");
4192 #if ENABLE_HUSH_TICK
4194 //int pos = dest->length;
4195 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4196 o_addchr(dest, 0x80 | '`');
4197 add_till_backquote(dest, input);
4198 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4199 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4203 o_addQchr(dest, ch);
4205 && (dest->o_assignment == MAYBE_ASSIGNMENT
4206 || dest->o_assignment == WORD_IS_KEYWORD)
4207 && is_assignment(dest->data)
4209 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4215 * Scan input until EOF or end_trigger char.
4216 * Return a list of pipes to execute, or NULL on EOF
4217 * or if end_trigger character is met.
4218 * On syntax error, exit is shell is not interactive,
4219 * reset parsing machinery and start parsing anew,
4220 * or return ERR_PTR.
4222 static struct pipe *parse_stream(struct in_str *input, int end_trigger)
4224 struct parse_context ctx;
4225 o_string dest = NULL_O_STRING;
4228 redir_type redir_style;
4232 /* Double-quote state is handled in the state variable is_in_dquote.
4233 * A single-quote triggers a bypass of the main loop until its mate is
4234 * found. When recursing, quote state is passed in via dest->o_escape. */
4236 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4237 end_trigger ? : 'X');
4240 #if ENABLE_HUSH_INTERACTIVE
4241 input->promptmode = 0; /* PS1 */
4243 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4244 initialize_context(&ctx);
4248 if (parse_stream_dquoted(&dest, input, '"')) {
4251 /* We reached closing '"' */
4256 ch = i_getch(input);
4260 next = i_peek(input);
4263 debug_printf_parse(": ch=%c (%d) m=%d escape=%d\n",
4264 ch, ch, m, dest.o_escape);
4265 if (m == CHAR_ORDINARY) {
4266 o_addQchr(&dest, ch);
4267 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4268 || dest.o_assignment == WORD_IS_KEYWORD)
4270 && is_assignment(dest.data)
4272 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4277 /* m is SPECIAL ($,`), IFS, or ORDINARY_IF_QUOTED (*,#) */
4279 if (m == CHAR_IFS) {
4282 if (done_word(&dest, &ctx)) {
4286 done_pipe(&ctx, PIPE_SEQ);
4287 /* If we got nothing... */
4289 if (pi->num_cmds == 0
4290 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4292 free_pipe_list(pi, 0);
4295 debug_printf_parse("parse_stream return %p\n", pi);
4298 if (done_word(&dest, &ctx)) {
4302 #if ENABLE_HUSH_CASE
4303 /* "case ... in <newline> word) ..." -
4304 * newlines are ignored (but ';' wouldn't be) */
4305 if (ctx.command->argv == NULL
4306 && ctx.ctx_res_w == RES_MATCH
4311 /* Treat newline as a command separator. */
4312 done_pipe(&ctx, PIPE_SEQ);
4313 dest.o_assignment = MAYBE_ASSIGNMENT;
4315 /* note: if (m == CHAR_IFS) continue;
4316 * will still trigger for us */
4319 if (end_trigger && end_trigger == ch) {
4320 //TODO: disallow "{ cmd }" without semicolon
4321 if (done_word(&dest, &ctx)) {
4324 done_pipe(&ctx, PIPE_SEQ);
4325 dest.o_assignment = MAYBE_ASSIGNMENT;
4326 /* Do we sit outside of any if's, loops or case's? */
4328 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4330 debug_printf_parse("parse_stream return %p: "
4331 "end_trigger char found\n",
4334 return ctx.list_head;
4340 /* m is SPECIAL (e.g. $,`) or ORDINARY_IF_QUOTED (*,#) */
4342 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4343 /* ch is a special char and thus this word
4344 * cannot be an assignment */
4345 dest.o_assignment = NOT_ASSIGNMENT;
4350 if (dest.length == 0) {
4353 if (ch == EOF || ch == '\n')
4358 o_addQchr(&dest, ch);
4366 o_addchr(&dest, '\\');
4367 o_addchr(&dest, i_getch(input));
4370 if (handle_dollar(&dest, input) != 0) {
4371 debug_printf_parse("parse_stream parse error: handle_dollar returned non-0\n");
4378 ch = i_getch(input);
4380 syntax("unterminated '");
4385 if (dest.o_assignment == NOT_ASSIGNMENT)
4386 o_addqchr(&dest, ch);
4388 o_addchr(&dest, ch);
4393 is_in_dquote ^= 1; /* invert */
4394 if (dest.o_assignment == NOT_ASSIGNMENT)
4397 #if ENABLE_HUSH_TICK
4399 //int pos = dest.length;
4400 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4401 o_addchr(&dest, '`');
4402 add_till_backquote(&dest, input);
4403 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4404 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4409 redir_fd = redirect_opt_num(&dest);
4410 if (done_word(&dest, &ctx)) {
4413 redir_style = REDIRECT_OVERWRITE;
4415 redir_style = REDIRECT_APPEND;
4419 else if (next == '(') {
4420 syntax(">(process) not supported");
4424 setup_redirect(&ctx, redir_fd, redir_style, input);
4427 redir_fd = redirect_opt_num(&dest);
4428 if (done_word(&dest, &ctx)) {
4431 redir_style = REDIRECT_INPUT;
4433 redir_style = REDIRECT_HEREIS;
4435 } else if (next == '>') {
4436 redir_style = REDIRECT_IO;
4440 else if (next == '(') {
4441 syntax("<(process) not supported");
4445 setup_redirect(&ctx, redir_fd, redir_style, input);
4448 #if ENABLE_HUSH_CASE
4451 if (done_word(&dest, &ctx)) {
4454 done_pipe(&ctx, PIPE_SEQ);
4455 #if ENABLE_HUSH_CASE
4456 /* Eat multiple semicolons, detect
4457 * whether it means something special */
4463 if (ctx.ctx_res_w == RES_CASEI) {
4464 ctx.ctx_dsemicolon = 1;
4465 ctx.ctx_res_w = RES_MATCH;
4471 /* We just finished a cmd. New one may start
4472 * with an assignment */
4473 dest.o_assignment = MAYBE_ASSIGNMENT;
4476 if (done_word(&dest, &ctx)) {
4481 done_pipe(&ctx, PIPE_AND);
4483 done_pipe(&ctx, PIPE_BG);
4487 if (done_word(&dest, &ctx)) {
4490 #if ENABLE_HUSH_CASE
4491 if (ctx.ctx_res_w == RES_MATCH)
4492 break; /* we are in case's "word | word)" */
4494 if (next == '|') { /* || */
4496 done_pipe(&ctx, PIPE_OR);
4498 /* we could pick up a file descriptor choice here
4499 * with redirect_opt_num(), but bash doesn't do it.
4500 * "echo foo 2| cat" yields "foo 2". */
4505 #if ENABLE_HUSH_CASE
4506 /* "case... in [(]word)..." - skip '(' */
4507 if (ctx.ctx_res_w == RES_MATCH
4508 && ctx.command->argv == NULL /* not (word|(... */
4509 && dest.length == 0 /* not word(... */
4510 && dest.nonnull == 0 /* not ""(... */
4515 #if ENABLE_HUSH_FUNCTIONS
4516 if (dest.length != 0 /* not just () but word() */
4517 && dest.nonnull == 0 /* not a"b"c() */
4518 && ctx.command->argv == NULL /* it's the first word */
4519 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4520 && i_peek(input) == ')'
4521 && !match_reserved_word(&dest)
4523 bb_error_msg("seems like a function definition");
4526 //TODO: do it properly.
4527 ch = i_getch(input);
4528 } while (ch == ' ' || ch == '\n');
4530 syntax("was expecting {");
4533 ch = 'F'; /* magic value */
4537 if (parse_group(&dest, &ctx, input, ch) != 0) {
4542 #if ENABLE_HUSH_CASE
4543 if (ctx.ctx_res_w == RES_MATCH)
4547 /* proper use of this character is caught by end_trigger:
4548 * if we see {, we call parse_group(..., end_trigger='}')
4549 * and it will match } earlier (not here). */
4550 syntax("unexpected } or )");
4554 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4560 struct parse_context *pctx;
4561 IF_HAS_KEYWORDS(struct parse_context *p2;)
4563 /* Clean up allocated tree.
4564 * Samples for finding leaks on syntax error recovery path.
4565 * Execute them from interactive shell and watch pmap `pidof hush`.
4566 * while if false; then false; fi do break; done (bash accepts it)
4567 * while if false; then false; fi; do break; fi
4571 /* Update pipe/command counts,
4572 * otherwise freeing may miss some */
4573 done_pipe(pctx, PIPE_SEQ);
4574 debug_printf_clean("freeing list %p from ctx %p\n",
4575 pctx->list_head, pctx);
4576 debug_print_tree(pctx->list_head, 0);
4577 free_pipe_list(pctx->list_head, 0);
4578 debug_printf_clean("freed list %p\n", pctx->list_head);
4579 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4583 IF_HAS_KEYWORDS(pctx = p2;)
4584 } while (HAS_KEYWORDS && pctx);
4585 /* Free text, clear all dest fields */
4587 /* If we are not in top-level parse, we return,
4588 * our caller will propagate error.
4590 if (end_trigger != ';')
4592 /* Discard cached input, force prompt */
4594 USE_HUSH_INTERACTIVE(input->promptme = 1;)
4599 static void set_in_charmap(const char *set, int code)
4602 G.charmap[(unsigned char)*set++] = code;
4605 static void update_charmap(void)
4607 G.ifs = getenv("IFS");
4610 /* Precompute a list of 'flow through' behavior so it can be treated
4611 * quickly up front. Computation is necessary because of IFS.
4612 * Special case handling of IFS == " \t\n" is not implemented.
4613 * The charmap[] array only really needs two bits each,
4614 * and on most machines that would be faster (reduced L1 cache use).
4616 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4617 #if ENABLE_HUSH_TICK
4618 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4620 set_in_charmap("\\$\"", CHAR_SPECIAL);
4622 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4623 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4626 /* Execiting from string: eval, sh -c '...'
4627 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4628 * end_trigger controls how often we stop parsing
4629 * NUL: parse all, execute, return
4630 * ';': parse till ';' or newline, execute, repeat till EOF
4632 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4635 struct pipe *pipe_list;
4639 pipe_list = parse_stream(inp, end_trigger);
4640 if (!pipe_list) /* EOF */
4642 debug_print_tree(pipe_list, 0);
4643 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4644 run_and_free_list(pipe_list);
4645 /* Loop on syntax errors, return on EOF: */
4649 static void parse_and_run_string(const char *s)
4651 struct in_str input;
4652 setup_string_in_str(&input, s);
4653 parse_and_run_stream(&input, '\0');
4656 static void parse_and_run_file(FILE *f)
4658 struct in_str input;
4659 setup_file_in_str(&input, f);
4660 parse_and_run_stream(&input, ';');
4664 /* Make sure we have a controlling tty. If we get started under a job
4665 * aware app (like bash for example), make sure we are now in charge so
4666 * we don't fight over who gets the foreground */
4667 static void setup_job_control(void)
4671 shell_pgrp = getpgrp();
4673 /* If we were ran as 'hush &',
4674 * sleep until we are in the foreground. */
4675 while (tcgetpgrp(G_interactive_fd) != shell_pgrp) {
4676 /* Send TTIN to ourself (should stop us) */
4677 kill(- shell_pgrp, SIGTTIN);
4678 shell_pgrp = getpgrp();
4681 /* We _must_ restore tty pgrp on fatal signals */
4682 set_fatal_signals_to_sigexit();
4684 /* Put ourselves in our own process group. */
4685 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4686 /* Grab control of the terminal. */
4687 tcsetpgrp(G_interactive_fd, getpid());
4691 static int set_mode(const char cstate, const char mode)
4693 int state = (cstate == '-' ? 1 : 0);
4695 case 'n': G.fake_mode = state; break;
4696 case 'x': /*G.debug_mode = state;*/ break;
4697 default: return EXIT_FAILURE;
4699 return EXIT_SUCCESS;
4702 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4703 int hush_main(int argc, char **argv)
4705 static const struct variable const_shell_ver = {
4707 .varstr = (char*)hush_version_str,
4708 .max_len = 1, /* 0 can provoke free(name) */
4716 struct variable *cur_var;
4720 G.root_pid = getpid();
4722 /* Deal with HUSH_VERSION */
4723 G.shell_ver = const_shell_ver; /* copying struct here */
4724 G.top_var = &G.shell_ver;
4725 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4726 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4727 /* Initialize our shell local variables with the values
4728 * currently living in the environment */
4729 cur_var = G.top_var;
4732 char *value = strchr(*e, '=');
4733 if (value) { /* paranoia */
4734 cur_var->next = xzalloc(sizeof(*cur_var));
4735 cur_var = cur_var->next;
4736 cur_var->varstr = *e;
4737 cur_var->max_len = strlen(*e);
4738 cur_var->flg_export = 1;
4742 debug_printf_env("putenv '%s'\n", hush_version_str);
4743 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4745 #if ENABLE_FEATURE_EDITING
4746 G.line_input_state = new_line_input_t(FOR_SHELL);
4748 /* XXX what should these be while sourcing /etc/profile? */
4749 G.global_argc = argc;
4750 G.global_argv = argv;
4751 /* Initialize some more globals to non-zero values */
4753 #if ENABLE_HUSH_INTERACTIVE
4754 if (ENABLE_FEATURE_EDITING)
4755 cmdedit_set_initial_prompt();
4759 if (EXIT_SUCCESS) /* otherwise is already done */
4760 G.last_return_code = EXIT_SUCCESS;
4762 if (argv[0] && argv[0][0] == '-') {
4763 debug_printf("sourcing /etc/profile\n");
4764 input = fopen_for_read("/etc/profile");
4765 if (input != NULL) {
4766 close_on_exec_on(fileno(input));
4767 parse_and_run_file(input);
4773 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4774 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4777 G.global_argv = argv + optind;
4778 if (!argv[optind]) {
4779 /* -c 'script' (no params): prevent empty $0 */
4780 *--G.global_argv = argv[0];
4782 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4783 G.global_argc = argc - optind;
4784 parse_and_run_string(optarg);
4787 /* Well, we cannot just declare interactiveness,
4788 * we have to have some stuff (ctty, etc) */
4789 /* G_interactive_fd++; */
4792 /* "-s" means "read from stdin", but this is how we always
4793 * operate, so simply do nothing here. */
4797 if (!set_mode('-', opt))
4801 fprintf(stderr, "Usage: sh [FILE]...\n"
4802 " or: sh -c command [args]...\n\n");
4810 /* A shell is interactive if the '-i' flag was given, or if all of
4811 * the following conditions are met:
4813 * no arguments remaining or the -s flag given
4814 * standard input is a terminal
4815 * standard output is a terminal
4816 * Refer to Posix.2, the description of the 'sh' utility. */
4817 if (argv[optind] == NULL && input == stdin
4818 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4820 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4821 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4822 if (G.saved_tty_pgrp >= 0) {
4823 /* try to dup to high fd#, >= 255 */
4824 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4825 if (G_interactive_fd < 0) {
4826 /* try to dup to any fd */
4827 G_interactive_fd = dup(STDIN_FILENO);
4828 if (G_interactive_fd < 0)
4830 G_interactive_fd = 0;
4832 // TODO: track & disallow any attempts of user
4833 // to (inadvertently) close/redirect it
4836 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4837 debug_printf("interactive_fd=%d\n", G_interactive_fd);
4838 if (G_interactive_fd) {
4839 fcntl(G_interactive_fd, F_SETFD, FD_CLOEXEC);
4840 /* Looks like they want an interactive shell */
4841 setup_job_control();
4842 /* -1 is special - makes xfuncs longjmp, not exit
4843 * (we reset die_sleep = 0 whereever we [v]fork) */
4845 if (setjmp(die_jmp)) {
4846 /* xfunc has failed! die die die */
4847 hush_exit(xfunc_error_retval);
4850 #elif ENABLE_HUSH_INTERACTIVE
4851 /* no job control compiled, only prompt/line editing */
4852 if (argv[optind] == NULL && input == stdin
4853 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4855 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4856 if (G_interactive_fd < 0) {
4857 /* try to dup to any fd */
4858 G_interactive_fd = dup(STDIN_FILENO);
4859 if (G_interactive_fd < 0)
4861 G_interactive_fd = 0;
4863 if (G_interactive_fd) {
4864 fcntl(G_interactive_fd, F_SETFD, FD_CLOEXEC);
4867 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4871 /* POSIX allows shell to re-enable SIGCHLD
4872 * even if it was SIG_IGN on entry */
4873 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4874 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4876 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4877 if (G_interactive_fd) {
4878 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4879 printf("Enter 'help' for a list of built-in commands.\n\n");
4883 if (argv[optind] == NULL) {
4884 parse_and_run_file(stdin);
4886 debug_printf("\nrunning script '%s'\n", argv[optind]);
4887 G.global_argv = argv + optind;
4888 G.global_argc = argc - optind;
4889 input = xfopen_for_read(argv[optind]);
4890 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4891 parse_and_run_file(input);
4896 #if ENABLE_FEATURE_CLEAN_UP
4898 if (G.cwd != bb_msg_unknown)
4900 cur_var = G.top_var->next;
4902 struct variable *tmp = cur_var;
4903 if (!cur_var->max_len)
4904 free(cur_var->varstr);
4905 cur_var = cur_var->next;
4909 hush_exit(G.last_return_code);
4914 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4915 int lash_main(int argc, char **argv)
4917 //bb_error_msg("lash is deprecated, please use hush instead");
4918 return hush_main(argc, argv);
4926 static int builtin_trap(char **argv)
4933 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4936 /* No args: print all trapped. This isn't 100% correct as we should
4937 * be escaping the cmd so that it can be pasted back in ...
4939 for (i = 0; i < NSIG; ++i)
4941 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4942 return EXIT_SUCCESS;
4947 /* if first arg is decimal: reset all specified */
4948 sig = bb_strtou(*++argv, NULL, 10);
4954 sig = get_signum(*argv++);
4955 if (sig < 0 || sig >= NSIG) {
4957 /* mimic bash message exactly */
4958 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4963 G.traps[sig] = xstrdup(new_cmd);
4965 debug_printf("trap: setting SIG%s (%i) to '%s'",
4966 get_signame(sig), sig, G.traps[sig]);
4968 /* There is no signal for 0 (EXIT) */
4973 sigaddset(&G.blocked_set, sig);
4975 /* there was a trap handler, we are removing it
4976 * (if sig has non-DFL handling,
4977 * we don't need to do anything) */
4978 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4980 sigdelset(&G.blocked_set, sig);
4982 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4987 /* first arg is "-": reset all specified to default */
4988 /* first arg is "": ignore all specified */
4989 /* everything else: execute first arg upon signal */
4991 bb_error_msg("trap: invalid arguments");
4992 return EXIT_FAILURE;
4994 if (LONE_DASH(*argv))
5002 static int builtin_true(char **argv UNUSED_PARAM)
5007 static int builtin_test(char **argv)
5014 return test_main(argc, argv - argc);
5017 static int builtin_echo(char **argv)
5024 return echo_main(argc, argv - argc);
5027 static int builtin_eval(char **argv)
5029 int rcode = EXIT_SUCCESS;
5032 char *str = expand_strvec_to_string(argv + 1);
5034 * eval "echo Hi; done" ("done" is syntax error):
5035 * "echo Hi" will not execute too.
5037 parse_and_run_string(str);
5039 rcode = G.last_return_code;
5044 static int builtin_cd(char **argv)
5047 if (argv[1] == NULL) {
5048 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5049 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5051 newdir = getenv("HOME") ? : "/";
5054 if (chdir(newdir)) {
5055 printf("cd: %s: %s\n", newdir, strerror(errno));
5056 return EXIT_FAILURE;
5059 return EXIT_SUCCESS;
5062 static int builtin_exec(char **argv)
5064 if (argv[1] == NULL)
5065 return EXIT_SUCCESS; /* bash does this */
5070 // FIXME: if exec fails, bash does NOT exit! We do...
5071 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
5076 static int builtin_exit(char **argv)
5078 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5079 //puts("exit"); /* bash does it */
5080 // TODO: warn if we have background jobs: "There are stopped jobs"
5081 // On second consecutive 'exit', exit anyway.
5082 if (argv[1] == NULL)
5083 hush_exit(G.last_return_code);
5084 /* mimic bash: exit 123abc == exit 255 + error msg */
5085 xfunc_error_retval = 255;
5086 /* bash: exit -2 == exit 254, no error msg */
5087 hush_exit(xatoi(argv[1]) & 0xff);
5090 static int builtin_export(char **argv)
5093 char *name = argv[1];
5097 // ash emits: export VAR='VAL'
5098 // bash: declare -x VAR="VAL"
5099 // (both also escape as needed (quotes, $, etc))
5104 return EXIT_SUCCESS;
5107 value = strchr(name, '=');
5109 /* They are exporting something without a =VALUE */
5110 struct variable *var;
5112 var = get_local_var(name);
5114 var->flg_export = 1;
5115 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5116 putenv(var->varstr);
5118 /* bash does not return an error when trying to export
5119 * an undefined variable. Do likewise. */
5120 return EXIT_SUCCESS;
5123 set_local_var(xstrdup(name), 1);
5124 return EXIT_SUCCESS;
5128 /* built-in 'fg' and 'bg' handler */
5129 static int builtin_fg_bg(char **argv)
5134 if (!G_interactive_fd)
5135 return EXIT_FAILURE;
5136 /* If they gave us no args, assume they want the last backgrounded task */
5138 for (pi = G.job_list; pi; pi = pi->next) {
5139 if (pi->jobid == G.last_jobid) {
5143 bb_error_msg("%s: no current job", argv[0]);
5144 return EXIT_FAILURE;
5146 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5147 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5148 return EXIT_FAILURE;
5150 for (pi = G.job_list; pi; pi = pi->next) {
5151 if (pi->jobid == jobnum) {
5155 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5156 return EXIT_FAILURE;
5158 // TODO: bash prints a string representation
5159 // of job being foregrounded (like "sleep 1 | cat")
5160 if (*argv[0] == 'f') {
5161 /* Put the job into the foreground. */
5162 tcsetpgrp(G_interactive_fd, pi->pgrp);
5165 /* Restart the processes in the job */
5166 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5167 for (i = 0; i < pi->num_cmds; i++) {
5168 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5169 pi->cmds[i].is_stopped = 0;
5171 pi->stopped_cmds = 0;
5173 i = kill(- pi->pgrp, SIGCONT);
5175 if (errno == ESRCH) {
5176 delete_finished_bg_job(pi);
5177 return EXIT_SUCCESS;
5179 bb_perror_msg("kill (SIGCONT)");
5183 if (*argv[0] == 'f') {
5185 return checkjobs_and_fg_shell(pi);
5187 return EXIT_SUCCESS;
5191 #if ENABLE_HUSH_HELP
5192 static int builtin_help(char **argv UNUSED_PARAM)
5194 const struct built_in_command *x;
5196 printf("\nBuilt-in commands:\n");
5197 printf("-------------------\n");
5198 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5199 printf("%s\t%s\n", x->cmd, x->descr);
5202 return EXIT_SUCCESS;
5207 static int builtin_jobs(char **argv UNUSED_PARAM)
5210 const char *status_string;
5212 for (job = G.job_list; job; job = job->next) {
5213 if (job->alive_cmds == job->stopped_cmds)
5214 status_string = "Stopped";
5216 status_string = "Running";
5218 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5220 return EXIT_SUCCESS;
5224 static int builtin_pwd(char **argv UNUSED_PARAM)
5227 return EXIT_SUCCESS;
5230 static int builtin_read(char **argv)
5233 const char *name = argv[1] ? argv[1] : "REPLY";
5235 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5236 return set_local_var(string, 0);
5239 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5240 * built-in 'set' handler
5242 * set [-abCefhmnuvx] [-o option] [argument...]
5243 * set [+abCefhmnuvx] [+o option] [argument...]
5244 * set -- [argument...]
5247 * Implementations shall support the options in both their hyphen and
5248 * plus-sign forms. These options can also be specified as options to sh.
5250 * Write out all variables and their values: set
5251 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5252 * Turn on the -x and -v options: set -xv
5253 * Unset all positional parameters: set --
5254 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5255 * Set the positional parameters to the expansion of x, even if x expands
5256 * with a leading '-' or '+': set -- $x
5258 * So far, we only support "set -- [argument...]" and some of the short names.
5260 static int builtin_set(char **argv)
5263 char **pp, **g_argv;
5264 char *arg = *++argv;
5268 for (e = G.top_var; e; e = e->next)
5270 return EXIT_SUCCESS;
5274 if (!strcmp(arg, "--")) {
5279 if (arg[0] == '+' || arg[0] == '-') {
5280 for (n = 1; arg[n]; ++n)
5281 if (set_mode(arg[0], arg[n]))
5287 } while ((arg = *++argv) != NULL);
5288 /* Now argv[0] is 1st argument */
5290 /* Only reset global_argv if we didn't process anything */
5292 return EXIT_SUCCESS;
5295 /* NB: G.global_argv[0] ($0) is never freed/changed */
5296 g_argv = G.global_argv;
5297 if (G.global_args_malloced) {
5303 G.global_args_malloced = 1;
5304 pp = xzalloc(sizeof(pp[0]) * 2);
5305 pp[0] = g_argv[0]; /* retain $0 */
5308 /* This realloc's G.global_argv */
5309 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5316 return EXIT_SUCCESS;
5318 /* Nothing known, so abort */
5320 bb_error_msg("set: %s: invalid option", arg);
5321 return EXIT_FAILURE;
5324 static int builtin_shift(char **argv)
5330 if (n >= 0 && n < G.global_argc) {
5331 if (G.global_args_malloced) {
5334 free(G.global_argv[m++]);
5337 memmove(&G.global_argv[1], &G.global_argv[n+1],
5338 G.global_argc * sizeof(G.global_argv[0]));
5339 return EXIT_SUCCESS;
5341 return EXIT_FAILURE;
5344 static int builtin_source(char **argv)
5348 if (argv[1] == NULL)
5349 return EXIT_FAILURE;
5351 /* XXX search through $PATH is missing */
5352 input = fopen_for_read(argv[1]);
5354 bb_error_msg("can't open '%s'", argv[1]);
5355 return EXIT_FAILURE;
5357 close_on_exec_on(fileno(input));
5359 /* Now run the file */
5360 /* XXX argv and argc are broken; need to save old G.global_argv
5361 * (pointer only is OK!) on this stack frame,
5362 * set G.global_argv=argv+1, recurse, and restore. */
5363 parse_and_run_file(input);
5365 return G.last_return_code;
5368 static int builtin_umask(char **argv)
5371 const char *arg = argv[1];
5373 new_umask = bb_strtou(arg, NULL, 8);
5375 return EXIT_FAILURE;
5377 new_umask = umask(0);
5378 printf("%.3o\n", (unsigned) new_umask);
5381 return EXIT_SUCCESS;
5384 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5385 static int builtin_unset(char **argv)
5392 return EXIT_SUCCESS;
5395 if (argv[1][0] == '-') {
5396 switch (argv[1][1]) {
5398 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5400 bb_error_msg("unset: %s: invalid option", argv[1]);
5401 return EXIT_FAILURE;
5409 if (unset_local_var(argv[i]))
5412 #if ENABLE_HUSH_FUNCTIONS
5414 unset_local_func(argv[i]);
5420 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5421 static int builtin_wait(char **argv)
5423 int ret = EXIT_SUCCESS;
5426 if (*++argv == NULL) {
5427 /* Don't care about wait results */
5428 /* Note 1: must wait until there are no more children */
5429 /* Note 2: must be interruptible */
5431 * $ sleep 3 & sleep 6 & wait
5436 * $ sleep 3 & sleep 6 & wait
5440 * ^C <-- after ~4 sec from keyboard
5443 sigaddset(&G.blocked_set, SIGCHLD);
5444 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5447 if (errno == ECHILD)
5449 /* Wait for SIGCHLD or any other signal of interest */
5450 /* sigtimedwait with infinite timeout: */
5451 sig = sigwaitinfo(&G.blocked_set, NULL);
5453 sig = check_and_run_traps(sig);
5454 if (sig && sig != SIGCHLD) { /* see note 2 */
5460 sigdelset(&G.blocked_set, SIGCHLD);
5461 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5465 /* This is probably buggy wrt interruptible-ness */
5467 pid_t pid = bb_strtou(*argv, NULL, 10);
5469 /* mimic bash message */
5470 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5471 return EXIT_FAILURE;
5473 if (waitpid(pid, &status, 0) == pid) {
5474 if (WIFSIGNALED(status))
5475 ret = 128 + WTERMSIG(status);
5476 else if (WIFEXITED(status))
5477 ret = WEXITSTATUS(status);
5481 bb_perror_msg("wait %s", *argv);
5490 #if ENABLE_HUSH_LOOPS
5491 static int builtin_break(char **argv)
5493 if (G.depth_of_loop == 0) {
5494 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5495 return EXIT_SUCCESS; /* bash compat */
5497 G.flag_break_continue++; /* BC_BREAK = 1 */
5498 G.depth_break_continue = 1;
5500 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5501 if (errno || !G.depth_break_continue || argv[2]) {
5502 bb_error_msg("%s: bad arguments", argv[0]);
5503 G.flag_break_continue = BC_BREAK;
5504 G.depth_break_continue = UINT_MAX;
5507 if (G.depth_of_loop < G.depth_break_continue)
5508 G.depth_break_continue = G.depth_of_loop;
5509 return EXIT_SUCCESS;
5512 static int builtin_continue(char **argv)
5514 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5515 return builtin_break(argv);