1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * Arithmetic Expansion
42 * <(list) and >(list) Process Substitution
43 * Here Documents ( << word )
46 * Parameter Expansion for substring processing ${var#word} ${var%word}
48 * Bash stuff maybe optional enable:
49 * &> and >& redirection of stdout+stderr
51 * reserved words: [[ ]] function select
52 * substrings ${var:1:5}
55 * job handling woefully incomplete and buggy (improved --vda)
57 * port selected bugfixes from post-0.49 busybox lash - done?
58 * change { and } from special chars to reserved words
59 * builtins: return, trap, ulimit
60 * test magic exec with redirection only
61 * follow IFS rules more precisely, including update semantics
62 * figure out what to do with backslash-newline
63 * propagate syntax errors, die on resource errors?
64 * continuation lines, both explicit and implicit - done?
65 * maybe change charmap[] to use 2-bit entries
67 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
70 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
71 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
72 //#include "applet_tables.h" doesn't work
74 /* #include <dmalloc.h> */
79 #define HUSH_VER_STR "0.92"
81 #if defined SINGLE_APPLET_MAIN
82 /* STANDALONE does not make sense, and won't compile */
83 #undef CONFIG_FEATURE_SH_STANDALONE
84 #undef ENABLE_FEATURE_SH_STANDALONE
85 #undef USE_FEATURE_SH_STANDALONE
86 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
87 #define ENABLE_FEATURE_SH_STANDALONE 0
88 #define USE_FEATURE_SH_STANDALONE(...)
89 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
92 #if !BB_MMU && ENABLE_HUSH_TICK
93 //#undef ENABLE_HUSH_TICK
94 //#define ENABLE_HUSH_TICK 0
95 #warning On NOMMU, hush command substitution is dangerous.
96 #warning Dont use it for commands which produce lots of output.
97 #warning For more info see shell/hush.c, generate_stream_from_list().
100 #if !ENABLE_HUSH_INTERACTIVE
101 #undef ENABLE_FEATURE_EDITING
102 #define ENABLE_FEATURE_EDITING 0
103 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
104 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
107 /* Do we support ANY keywords? */
108 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
109 #define HAS_KEYWORDS 1
110 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
111 #define IF_HAS_NO_KEYWORDS(...)
113 #define HAS_KEYWORDS 0
114 #define IF_HAS_KEYWORDS(...)
115 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
118 /* Keep unconditionally on for now */
121 #define ENABLE_HUSH_FUNCTIONS 0
124 /* If you comment out one of these below, it will be #defined later
125 * to perform debug printfs to stderr: */
126 #define debug_printf(...) do {} while (0)
127 /* Finer-grained debug switches */
128 #define debug_printf_parse(...) do {} while (0)
129 #define debug_print_tree(a, b) do {} while (0)
130 #define debug_printf_exec(...) do {} while (0)
131 #define debug_printf_env(...) do {} while (0)
132 #define debug_printf_jobs(...) do {} while (0)
133 #define debug_printf_expand(...) do {} while (0)
134 #define debug_printf_glob(...) do {} while (0)
135 #define debug_printf_list(...) do {} while (0)
136 #define debug_printf_subst(...) do {} while (0)
137 #define debug_printf_clean(...) do {} while (0)
140 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
143 #ifndef debug_printf_parse
144 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
147 #ifndef debug_printf_exec
148 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
151 #ifndef debug_printf_env
152 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
155 #ifndef debug_printf_jobs
156 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
162 #ifndef debug_printf_expand
163 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
164 #define DEBUG_EXPAND 1
166 #define DEBUG_EXPAND 0
169 #ifndef debug_printf_glob
170 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
176 #ifndef debug_printf_list
177 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
180 #ifndef debug_printf_subst
181 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
184 #ifndef debug_printf_clean
185 /* broken, of course, but OK for testing */
186 static const char *indenter(int i)
188 static const char blanks[] ALIGN1 =
190 return &blanks[sizeof(blanks) - i - 1];
192 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
193 #define DEBUG_CLEAN 1
197 static void debug_print_strings(const char *prefix, char **vv)
199 fprintf(stderr, "%s:\n", prefix);
201 fprintf(stderr, " '%s'\n", *vv++);
204 #define debug_print_strings(prefix, vv) ((void)0)
208 * Leak hunting. Use hush_leaktool.sh for post-processing.
210 #ifdef FOR_HUSH_LEAKTOOL
211 /* suppress "warning: no previous prototype..." */
212 void *xxmalloc(int lineno, size_t size);
213 void *xxrealloc(int lineno, void *ptr, size_t size);
214 char *xxstrdup(int lineno, const char *str);
215 void xxfree(void *ptr);
216 void *xxmalloc(int lineno, size_t size)
218 void *ptr = xmalloc((size + 0xff) & ~0xff);
219 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
222 void *xxrealloc(int lineno, void *ptr, size_t size)
224 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
225 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
228 char *xxstrdup(int lineno, const char *str)
230 char *ptr = xstrdup(str);
231 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
234 void xxfree(void *ptr)
236 fprintf(stderr, "free %p\n", ptr);
239 #define xmalloc(s) xxmalloc(__LINE__, s)
240 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
241 #define xstrdup(s) xxstrdup(__LINE__, s)
242 #define free(p) xxfree(p)
246 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
248 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
250 #define SPECIAL_VAR_SYMBOL 3
251 #define PARSEFLAG_EXIT_FROM_LOOP 1
253 typedef enum redir_type {
255 REDIRECT_OVERWRITE = 2,
261 /* The descrip member of this structure is only used to make
262 * debugging output pretty */
263 static const struct {
265 signed char default_fd;
269 { O_RDONLY, 0, "<" },
270 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
271 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
272 { O_RDONLY, -1, "<<" },
276 typedef enum pipe_style {
283 typedef enum reserved_style {
292 #if ENABLE_HUSH_LOOPS
299 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
304 /* two pseudo-keywords support contrived "case" syntax: */
305 RES_MATCH , /* "word)" */
306 RES_CASEI , /* "this command is inside CASE" */
313 struct redir_struct {
314 struct redir_struct *next;
315 char *rd_filename; /* filename */
316 int fd; /* file descriptor being redirected */
317 int dup; /* -1, or file descriptor being duplicated */
318 smallint /*enum redir_type*/ rd_type;
322 pid_t pid; /* 0 if exited */
323 int assignment_cnt; /* how many argv[i] are assignments? */
324 smallint is_stopped; /* is the command currently running? */
325 smallint grp_type; /* GRP_xxx */
326 struct pipe *group; /* if non-NULL, this "prog" is {} group,
327 * subshell, or a compound statement */
328 char **argv; /* command name and arguments */
329 struct redir_struct *redirects; /* I/O redirections */
331 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
332 * and on execution these are substituted with their values.
333 * Substitution can make _several_ words out of one argv[n]!
334 * Example: argv[0]=='.^C*^C.' here: echo .$*.
335 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
338 #define GRP_SUBSHELL 1
339 #if ENABLE_HUSH_FUNCTIONS
340 #define GRP_FUNCTION 2
345 int num_cmds; /* total number of commands in job */
346 int alive_cmds; /* number of commands running (not exited) */
347 int stopped_cmds; /* number of commands alive, but stopped */
349 int jobid; /* job number */
350 pid_t pgrp; /* process group ID for the job */
351 char *cmdtext; /* name of job */
353 struct command *cmds; /* array of commands in pipe */
354 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
355 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
356 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
359 /* This holds pointers to the various results of parsing */
360 struct parse_context {
361 struct command *command;
362 struct pipe *list_head;
364 struct redir_struct *pending_redirect;
367 smallint ctx_inverted; /* "! cmd | cmd" */
369 smallint ctx_dsemicolon; /* ";;" seen */
371 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
372 struct parse_context *stack;
376 /* On program start, environ points to initial environment.
377 * putenv adds new pointers into it, unsetenv removes them.
378 * Neither of these (de)allocates the strings.
379 * setenv allocates new strings in malloc space and does putenv,
380 * and thus setenv is unusable (leaky) for shell's purposes */
381 #define setenv(...) setenv_is_leaky_dont_use()
383 struct variable *next;
384 char *varstr; /* points to "name=" portion */
385 int max_len; /* if > 0, name is part of initial env; else name is malloced */
386 smallint flg_export; /* putenv should be done on this var */
387 smallint flg_read_only;
390 typedef struct o_string {
392 int length; /* position where data is appended */
394 /* Misnomer! it's not "quoting", it's "protection against globbing"!
395 * (by prepending \ to *, ?, [ and to \ too) */
399 smallint has_empty_slot;
400 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
403 MAYBE_ASSIGNMENT = 0,
404 DEFINITELY_ASSIGNMENT = 1,
406 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
408 /* Used for initialization: o_string foo = NULL_O_STRING; */
409 #define NULL_O_STRING { NULL }
411 /* I can almost use ordinary FILE*. Is open_memstream() universally
412 * available? Where is it documented? */
413 typedef struct in_str {
415 /* eof_flag=1: last char in ->p is really an EOF */
416 char eof_flag; /* meaningless if ->p == NULL */
418 #if ENABLE_HUSH_INTERACTIVE
420 smallint promptmode; /* 0: PS1, 1: PS2 */
423 int (*get) (struct in_str *);
424 int (*peek) (struct in_str *);
426 #define i_getch(input) ((input)->get(input))
427 #define i_peek(input) ((input)->peek(input))
431 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
432 CHAR_IFS = 2, /* treated as ordinary if quoted */
433 CHAR_SPECIAL = 3, /* example: $ */
442 /* "Globals" within this file */
443 /* Sorted roughly by size (smaller offsets == smaller code) */
445 #if ENABLE_HUSH_INTERACTIVE
446 /* 'interactive_fd' is a fd# open to ctty, if we have one
447 * _AND_ if we decided to act interactively */
452 #if ENABLE_FEATURE_EDITING
453 line_input_t *line_input_state;
459 pid_t saved_tty_pgrp;
461 struct pipe *job_list;
462 struct pipe *toplevel_list;
463 //// smallint ctrl_z_flag;
465 #if ENABLE_HUSH_LOOPS
466 smallint flag_break_continue;
469 /* These four support $?, $#, and $1 */
470 smalluint last_return_code;
471 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
472 smalluint global_args_malloced;
473 /* how many non-NULL argv's we have. NB: $# + 1 */
476 #if ENABLE_HUSH_LOOPS
477 unsigned depth_break_continue;
478 unsigned depth_of_loop;
482 struct variable *top_var; /* = &G.shell_ver (set in main()) */
483 struct variable shell_ver;
484 #if ENABLE_FEATURE_SH_STANDALONE
485 struct nofork_save_area nofork_save;
488 sigjmp_buf toplevel_jb;
490 unsigned char charmap[256];
491 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
492 /* Signal and trap handling */
493 char **traps; /* char *traps[NSIG] */
494 /* which signals have non-DFL handler (even with no traps set)? */
495 unsigned non_DFL_mask;
496 /* which signals are known to be IGNed on entry to shell? */
498 sigset_t blocked_set;
499 sigset_t inherited_set;
502 #define G (*ptr_to_globals)
503 /* Not #defining name to G.name - this quickly gets unwieldy
504 * (too many defines). Also, I actually prefer to see when a variable
505 * is global, thus "G." prefix is a useful hint */
506 #define INIT_G() do { \
507 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
511 /* Function prototypes for builtins */
512 static int builtin_cd(char **argv);
513 static int builtin_echo(char **argv);
514 static int builtin_eval(char **argv);
515 static int builtin_exec(char **argv);
516 static int builtin_exit(char **argv);
517 static int builtin_export(char **argv);
519 static int builtin_fg_bg(char **argv);
520 static int builtin_jobs(char **argv);
523 static int builtin_help(char **argv);
525 static int builtin_pwd(char **argv);
526 static int builtin_read(char **argv);
527 static int builtin_test(char **argv);
528 static int builtin_trap(char **argv);
529 static int builtin_true(char **argv);
530 static int builtin_set(char **argv);
531 static int builtin_shift(char **argv);
532 static int builtin_source(char **argv);
533 static int builtin_umask(char **argv);
534 static int builtin_unset(char **argv);
535 static int builtin_wait(char **argv);
536 #if ENABLE_HUSH_LOOPS
537 static int builtin_break(char **argv);
538 static int builtin_continue(char **argv);
540 //static int builtin_not_written(char **argv);
542 /* Table of built-in functions. They can be forked or not, depending on
543 * context: within pipes, they fork. As simple commands, they do not.
544 * When used in non-forking context, they can change global variables
545 * in the parent shell process. If forked, of course they cannot.
546 * For example, 'unset foo | whatever' will parse and run, but foo will
547 * still be set at the end. */
548 struct built_in_command {
550 int (*function)(char **argv);
553 #define BLTIN(cmd, func, help) { cmd, func, help }
555 #define BLTIN(cmd, func, help) { cmd, func }
559 /* For now, echo and test are unconditionally enabled.
560 * Maybe make it configurable? */
561 static const struct built_in_command bltins[] = {
562 BLTIN("." , builtin_source, "Run commands in a file"),
563 BLTIN(":" , builtin_true, "No-op"),
564 BLTIN("[" , builtin_test, "Test condition"),
566 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
568 #if ENABLE_HUSH_LOOPS
569 BLTIN("break" , builtin_break, "Exit from a loop"),
571 BLTIN("cd" , builtin_cd, "Change directory"),
572 #if ENABLE_HUSH_LOOPS
573 BLTIN("continue", builtin_continue, "Start new loop iteration"),
575 BLTIN("echo" , builtin_echo, "Write to stdout"),
576 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
577 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
578 BLTIN("exit" , builtin_exit, "Exit"),
579 BLTIN("export", builtin_export, "Set environment variable"),
581 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
582 BLTIN("jobs" , builtin_jobs, "List active jobs"),
584 BLTIN("pwd" , builtin_pwd, "Print current directory"),
585 BLTIN("read" , builtin_read, "Input environment variable"),
586 // BLTIN("return", builtin_not_written, "Return from a function"),
587 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
588 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
589 BLTIN("test" , builtin_test, "Test condition"),
590 BLTIN("trap" , builtin_trap, "Trap signals"),
591 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
592 BLTIN("umask" , builtin_umask, "Set file creation mask"),
593 BLTIN("unset" , builtin_unset, "Unset environment variable"),
594 BLTIN("wait" , builtin_wait, "Wait for process"),
596 BLTIN("help" , builtin_help, "List shell built-in commands"),
602 static void maybe_die(const char *notice, const char *msg)
604 /* Was using fancy stuff:
605 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
606 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
607 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
608 #if ENABLE_HUSH_INTERACTIVE
609 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
611 fp(msg ? "%s: %s" : notice, notice, msg);
614 #define syntax(msg) maybe_die("syntax error", msg);
616 /* Debug -- trick gcc to expand __LINE__ and convert to string */
617 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
618 #define _syntax(msg, line) __syntax(msg, line)
619 #define syntax(msg) _syntax(msg, __LINE__)
622 static int glob_needed(const char *s)
627 if (*s == '*' || *s == '[' || *s == '?')
634 static int is_assignment(const char *s)
636 if (!s || !(isalpha(*s) || *s == '_'))
639 while (isalnum(*s) || *s == '_')
644 /* Replace each \x with x in place, return ptr past NUL. */
645 static char *unbackslash(char *src)
651 if ((*dst++ = *src++) == '\0')
657 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
678 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
679 v[count1 + count2] = NULL;
682 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
686 static char **add_string_to_strings(char **strings, char *add)
691 return add_strings_to_strings(strings, v, /*dup:*/ 0);
694 static void putenv_all(char **strings)
699 debug_printf_env("putenv '%s'\n", *strings);
704 static char **putenv_all_and_save_old(char **strings)
714 eq = strchr(*strings, '=');
717 v = getenv(*strings);
720 /* v points to VAL in VAR=VAL, go back to VAR */
721 v -= (eq - *strings) + 1;
722 old = add_string_to_strings(old, v);
731 static void free_strings_and_unsetenv(char **strings, int unset)
741 debug_printf_env("unsetenv '%s'\n", *v);
749 static void free_strings(char **strings)
751 free_strings_and_unsetenv(strings, 0);
755 /* Basic theory of signal handling in shell
756 * ========================================
757 * This does not describe what hush does, rahter, it is current understanding
758 * what it _should_ do.
759 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
761 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
762 * is finished or backgrounded. It is the same in interactive and
763 * non-interactive shells, and is the same regardless of whether
764 * a user trap handler is installed or a default one is in effect.
765 * ^C or ^Z from keyboard seem to execute "at once" because it usually
766 * backgrounds (i.e. stops) or kills all members of currently running
769 * Wait builtin in interruptible by signals for which user trap is set
770 * or by SIGINT in interactive shell.
772 * Trap handlers will execute even within trap handlers. (right?)
774 * User trap handlers are forgotten when subshell is entered.
776 * If job control is off, backgrounded commands ("cmd &")
777 * have SIGINT, SIGQUIT set to SIG_IGN.
779 * Commands run in command substitution ("`cmd`")
780 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
782 * Ordinary commands have IGN/DFL set as inherited by the shell
785 * Default handlers which differ from DFL action
786 * (note: subshell is not an interactive shell):
789 * SIGTERM (interactive): ignore
790 * SUGHUP (interactive): send SIGCONT to stopped jobs,
791 * send SIGHUP to all jobs and exit
792 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
793 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
794 * that all pipe members are stopped) (right?)
795 * SIGINT (interactive): wait for last pipe, ignore the rest
796 * of the command line, show prompt. (check/expand this)
797 * Example 1: this waits 5 sec, but does not execute ls:
798 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
799 * Example 2: this does not wait and does not execute ls:
800 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
802 * (What happens to signals which are IGN on shell start?)
803 * (What happens with signal mask on shell start?)
805 * Implementation in hush
806 * ======================
807 * We use in-kernel pending signal mask to determine which signals were sent.
808 * We block all signals which we don't want to take action immediately,
809 * i.e. we block all signals which need to have special handling as described
810 * above, and all signals which have traps set.
811 * After each pipe execution, we extract any pending signals via sigtimedwait()
814 * unsigned non_DFL_mask: a mask of such "special" signals
815 * sigset_t blocked_set: current blocked signal set
817 * "trap - SIGxxx": clear bit in blocked_set unless it is also in non_DFL
818 * "trap 'cmd' SIGxxx": set bit in blocked_set (even if 'cmd' is '')
819 * after [v]fork, if we plan to be a shell:
820 * nothing for {} subshell (say, "true | { true; true; } | true")
821 * unset all traps if () shell. [TODO]
822 * after [v]fork, if we plan to exec:
823 * POSIX says pending signal mask is cleared in child - no need to clear it.
824 * restore blocked signal set to one inherited by shell just prior to exec.
826 * Note: as a result, we do not use signal handlers much. The only use
827 * is to restore terminal pgrp on exit.
829 * TODO: check/fix wait builtin to be interruptible.
832 /* called once at shell init */
833 static void init_signal_mask(void)
836 unsigned mask = (1 << SIGQUIT);
837 #if ENABLE_HUSH_INTERACTIVE
838 if (G.interactive_fd) {
844 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
850 G.non_DFL_mask = mask;
852 /*sigemptyset(&G.blocked_set); - already is */
853 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
857 sigaddset(&G.blocked_set, sig);
861 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
863 static void check_and_run_traps(void)
865 static const struct timespec zero_ts = { 0, 0 };
866 smalluint save_rcode;
870 sig = sigtimedwait(&G.blocked_set, NULL, &zero_ts);
874 if (G.traps && G.traps[sig]) {
875 if (G.traps[sig][0]) {
876 /* We have user-defined handler */
877 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
878 save_rcode = G.last_return_code;
881 G.last_return_code = save_rcode;
882 } /* else: "" trap, ignoring signal */
885 /* not a trap: special action */
892 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
898 /* The stuff below needs to be migrated to "Special action" above */
900 /////* Signals are grouped, we handle them in batches */
901 ////static void set_misc_sighandler(void (*handler)(int))
905 //// + (1 << SIGQUIT)
906 //// + (1 << SIGTERM)
913 static unsigned maybe_set_sighandler(int sig, void (*handler)(int))
915 /* non_DFL_mask'ed signals are, well, masked,
916 * no need to set handler for them.
917 * IGN_mask'ed signals were found to be IGN on entry,
918 * do not change that -> no need to set handler for them either
920 unsigned ign = ((G.IGN_mask|G.non_DFL_mask) >> sig) & 1;
922 handler = signal(sig, handler);
923 ign = (handler == SIG_IGN);
924 if (ign) /* restore back to IGN! */
925 signal(sig, handler);
927 return ign << sig; /* pass back knowledge about SIG_IGN */
929 /* Used only to set handler to restore pgrp on exit, and to reset it to DFL */
930 static void set_fatal_sighandler(void (*handler)(int))
935 mask |= maybe_set_sighandler(SIGILL , handler);
936 mask |= maybe_set_sighandler(SIGFPE , handler);
937 mask |= maybe_set_sighandler(SIGBUS , handler);
938 mask |= maybe_set_sighandler(SIGSEGV, handler);
939 mask |= maybe_set_sighandler(SIGTRAP, handler);
940 } /* else: hush is perfect. what SEGV? */
942 mask |= maybe_set_sighandler(SIGABRT, handler);
944 /* bash 3.2 seems to handle these just like 'fatal' ones */
945 mask |= maybe_set_sighandler(SIGPIPE, handler);
946 mask |= maybe_set_sighandler(SIGALRM, handler);
947 mask |= maybe_set_sighandler(SIGHUP , handler);
949 /* if we aren't interactive... but in this case
950 * we never want to restore pgrp on exit, and this fn is not called */
951 /*mask |= maybe_set_sighandler(SIGTERM, handler); */
952 /*mask |= maybe_set_sighandler(SIGINT , handler); */
956 /* Used only to suppress ^Z in `cmd` */
957 static void IGN_jobctrl_signals(void)
965 /* SIGCHLD is special and handled separately */
967 ////static void set_every_sighandler(void (*handler)(int))
969 //// set_fatal_sighandler(handler);
970 //// set_jobctrl_sighandler(handler);
971 //// set_misc_sighandler(handler);
972 //// signal(SIGCHLD, handler);
975 ////static void handler_ctrl_c(int sig UNUSED_PARAM)
977 //// debug_printf_jobs("got sig %d\n", sig);
978 ////// as usual we can have all kinds of nasty problems with leaked malloc data here
979 //// siglongjmp(G.toplevel_jb, 1);
982 ////static void handler_ctrl_z(int sig UNUSED_PARAM)
986 //// debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
989 //// fputs("Sorry, backgrounding (CTRL+Z) of foreground scripts not supported on nommu\n", stderr);
994 //// if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
996 //// G.ctrl_z_flag = 1;
997 //// if (!pid) { /* child */
998 //// if (ENABLE_HUSH_JOB)
999 //// die_sleep = 0; /* let nofork's xfuncs die */
1001 //// debug_printf_jobs("set pgrp for child %d ok\n", getpid());
1002 //////// set_every_sighandler(SIG_DFL);
1003 //// raise(SIGTSTP); /* resend TSTP so that child will be stopped */
1004 //// debug_printf_jobs("returning in child\n");
1005 //// /* return to nofork, it will eventually exit now,
1006 //// * not return back to shell */
1010 //// /* finish filling up pipe info */
1011 //// G.toplevel_list->pgrp = pid; /* child is in its own pgrp */
1012 //// G.toplevel_list->cmds[0].pid = pid;
1013 //// /* parent needs to longjmp out of running nofork.
1014 //// * we will "return" exitcode 0, with child put in background */
1015 ////// as usual we can have all kinds of nasty problems with leaked malloc data here
1016 //// debug_printf_jobs("siglongjmp in parent\n");
1017 //// siglongjmp(G.toplevel_jb, 1);
1020 /* Restores tty foreground process group, and exits.
1021 * May be called as signal handler for fatal signal
1022 * (will faithfully resend signal to itself, producing correct exit state)
1023 * or called directly with -EXITCODE.
1024 * We also call it if xfunc is exiting. */
1025 static void sigexit(int sig) NORETURN;
1026 static void sigexit(int sig)
1028 /* Disable all signals: job control, SIGPIPE, etc. */
1029 sigprocmask_allsigs(SIG_BLOCK);
1031 #if ENABLE_HUSH_INTERACTIVE
1032 if (G.interactive_fd)
1033 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
1036 /* Not a signal, just exit */
1040 kill_myself_with_sig(sig); /* does not return */
1045 #define set_fatal_sighandler(handler) ((void)0)
1046 #define IGN_jobctrl_signals(handler) ((void)0)
1050 /* Restores tty foreground process group, and exits. */
1051 static void hush_exit(int exitcode) NORETURN;
1052 static void hush_exit(int exitcode)
1054 if (G.traps && G.traps[0] && G.traps[0][0]) {
1055 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1060 if (ENABLE_HUSH_JOB) {
1061 fflush(NULL); /* flush all streams */
1062 sigexit(- (exitcode & 0xff));
1068 static const char *set_cwd(void)
1070 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1071 * we must not try to free(bb_msg_unknown) */
1072 if (G.cwd == bb_msg_unknown)
1074 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1076 G.cwd = bb_msg_unknown;
1081 /* Get/check local shell variables */
1082 static struct variable *get_local_var(const char *name)
1084 struct variable *cur;
1090 for (cur = G.top_var; cur; cur = cur->next) {
1091 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1097 /* Basically useful version until someone wants to get fancier,
1098 * see the bash man page under "Parameter Expansion" */
1099 static const char *lookup_param(const char *src)
1101 struct variable *var = get_local_var(src);
1103 return strchr(var->varstr, '=') + 1;
1107 /* str holds "NAME=VAL" and is expected to be malloced.
1108 * We take ownership of it.
1109 * flg_export is used by:
1112 * -1: if NAME is set, leave export status alone
1113 * if NAME is not set, do not export
1115 static int set_local_var(char *str, int flg_export)
1117 struct variable *cur;
1121 value = strchr(str, '=');
1122 if (!value) { /* not expected to ever happen? */
1127 name_len = value - str + 1; /* including '=' */
1128 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1130 if (strncmp(cur->varstr, str, name_len) != 0) {
1132 /* Bail out. Note that now cur points
1133 * to last var in linked list */
1139 /* We found an existing var with this name */
1141 if (cur->flg_read_only) {
1142 bb_error_msg("%s: readonly variable", str);
1146 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1147 unsetenv(str); /* just in case */
1149 if (strcmp(cur->varstr, str) == 0) {
1154 if (cur->max_len >= strlen(str)) {
1155 /* This one is from startup env, reuse space */
1156 strcpy(cur->varstr, str);
1159 /* max_len == 0 signifies "malloced" var, which we can
1160 * (and has to) free */
1164 goto set_str_and_exp;
1167 /* Not found - create next variable struct */
1168 cur->next = xzalloc(sizeof(*cur));
1174 if (flg_export == 1)
1175 cur->flg_export = 1;
1176 if (cur->flg_export) {
1177 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1178 return putenv(cur->varstr);
1183 static int unset_local_var(const char *name)
1185 struct variable *cur;
1186 struct variable *prev = prev; /* for gcc */
1190 return EXIT_SUCCESS;
1191 name_len = strlen(name);
1194 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1195 if (cur->flg_read_only) {
1196 bb_error_msg("%s: readonly variable", name);
1197 return EXIT_FAILURE;
1199 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1200 * is ro, and we cannot reach this code on the 1st pass */
1201 prev->next = cur->next;
1202 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1203 bb_unsetenv(cur->varstr);
1207 return EXIT_SUCCESS;
1212 return EXIT_SUCCESS;
1219 static int static_get(struct in_str *i)
1222 if (ch == '\0') return EOF;
1226 static int static_peek(struct in_str *i)
1231 #if ENABLE_HUSH_INTERACTIVE
1233 static void cmdedit_set_initial_prompt(void)
1235 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1236 G.PS1 = getenv("PS1");
1243 static const char* setup_prompt_string(int promptmode)
1245 const char *prompt_str;
1246 debug_printf("setup_prompt_string %d ", promptmode);
1247 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1248 /* Set up the prompt */
1249 if (promptmode == 0) { /* PS1 */
1251 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1256 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1257 debug_printf("result '%s'\n", prompt_str);
1261 static void get_user_input(struct in_str *i)
1264 const char *prompt_str;
1266 prompt_str = setup_prompt_string(i->promptmode);
1267 #if ENABLE_FEATURE_EDITING
1268 /* Enable command line editing only while a command line
1269 * is actually being read */
1271 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1272 } while (r == 0); /* repeat if Ctrl-C */
1273 i->eof_flag = (r < 0);
1274 if (i->eof_flag) { /* EOF/error detected */
1275 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1276 G.user_input_buf[1] = '\0';
1279 fputs(prompt_str, stdout);
1281 G.user_input_buf[0] = r = fgetc(i->file);
1282 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1283 i->eof_flag = (r == EOF);
1285 i->p = G.user_input_buf;
1288 #endif /* INTERACTIVE */
1290 /* This is the magic location that prints prompts
1291 * and gets data back from the user */
1292 static int file_get(struct in_str *i)
1296 /* If there is data waiting, eat it up */
1297 if (i->p && *i->p) {
1298 #if ENABLE_HUSH_INTERACTIVE
1302 if (i->eof_flag && !*i->p)
1305 /* need to double check i->file because we might be doing something
1306 * more complicated by now, like sourcing or substituting. */
1307 #if ENABLE_HUSH_INTERACTIVE
1308 if (G.interactive_fd && i->promptme && i->file == stdin) {
1311 } while (!*i->p); /* need non-empty line */
1312 i->promptmode = 1; /* PS2 */
1317 ch = fgetc(i->file);
1319 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1320 #if ENABLE_HUSH_INTERACTIVE
1327 /* All the callers guarantee this routine will never be
1328 * used right after a newline, so prompting is not needed.
1330 static int file_peek(struct in_str *i)
1333 if (i->p && *i->p) {
1334 if (i->eof_flag && !i->p[1])
1338 ch = fgetc(i->file);
1339 i->eof_flag = (ch == EOF);
1340 i->peek_buf[0] = ch;
1341 i->peek_buf[1] = '\0';
1343 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1347 static void setup_file_in_str(struct in_str *i, FILE *f)
1349 i->peek = file_peek;
1351 #if ENABLE_HUSH_INTERACTIVE
1353 i->promptmode = 0; /* PS1 */
1359 static void setup_string_in_str(struct in_str *i, const char *s)
1361 i->peek = static_peek;
1362 i->get = static_get;
1363 #if ENABLE_HUSH_INTERACTIVE
1365 i->promptmode = 0; /* PS1 */
1375 #define B_CHUNK (32 * sizeof(char*))
1377 static void o_reset(o_string *o)
1385 static void o_free(o_string *o)
1388 memset(o, 0, sizeof(*o));
1391 static void o_grow_by(o_string *o, int len)
1393 if (o->length + len > o->maxlen) {
1394 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1395 o->data = xrealloc(o->data, 1 + o->maxlen);
1399 static void o_addchr(o_string *o, int ch)
1401 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1403 o->data[o->length] = ch;
1405 o->data[o->length] = '\0';
1408 static void o_addstr(o_string *o, const char *str, int len)
1411 memcpy(&o->data[o->length], str, len);
1413 o->data[o->length] = '\0';
1416 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1421 && (*str != '*' && *str != '?' && *str != '[')
1429 /* My analysis of quoting semantics tells me that state information
1430 * is associated with a destination, not a source.
1432 static void o_addqchr(o_string *o, int ch)
1435 char *found = strchr("*?[\\", ch);
1440 o->data[o->length] = '\\';
1443 o->data[o->length] = ch;
1445 o->data[o->length] = '\0';
1448 static void o_addQchr(o_string *o, int ch)
1451 if (o->o_quote && strchr("*?[\\", ch)) {
1453 o->data[o->length] = '\\';
1457 o->data[o->length] = ch;
1459 o->data[o->length] = '\0';
1462 static void o_addQstr(o_string *o, const char *str, int len)
1465 o_addstr(o, str, len);
1471 int ordinary_cnt = strcspn(str, "*?[\\");
1472 if (ordinary_cnt > len) /* paranoia */
1474 o_addstr(o, str, ordinary_cnt);
1475 if (ordinary_cnt == len)
1477 str += ordinary_cnt;
1478 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1482 if (ch) { /* it is necessarily one of "*?[\\" */
1484 o->data[o->length] = '\\';
1488 o->data[o->length] = ch;
1490 o->data[o->length] = '\0';
1494 /* A special kind of o_string for $VAR and `cmd` expansion.
1495 * It contains char* list[] at the beginning, which is grown in 16 element
1496 * increments. Actual string data starts at the next multiple of 16 * (char*).
1497 * list[i] contains an INDEX (int!) into this string data.
1498 * It means that if list[] needs to grow, data needs to be moved higher up
1499 * but list[i]'s need not be modified.
1500 * NB: remembering how many list[i]'s you have there is crucial.
1501 * o_finalize_list() operation post-processes this structure - calculates
1502 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1504 #if DEBUG_EXPAND || DEBUG_GLOB
1505 static void debug_print_list(const char *prefix, o_string *o, int n)
1507 char **list = (char**)o->data;
1508 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1510 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1511 prefix, list, n, string_start, o->length, o->maxlen);
1513 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1514 o->data + (int)list[i] + string_start,
1515 o->data + (int)list[i] + string_start);
1519 const char *p = o->data + (int)list[n - 1] + string_start;
1520 fprintf(stderr, " total_sz:%ld\n", (p + strlen(p) + 1) - o->data);
1524 #define debug_print_list(prefix, o, n) ((void)0)
1527 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1528 * in list[n] so that it points past last stored byte so far.
1529 * It returns n+1. */
1530 static int o_save_ptr_helper(o_string *o, int n)
1532 char **list = (char**)o->data;
1536 if (!o->has_empty_slot) {
1537 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1538 string_len = o->length - string_start;
1539 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1540 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1541 /* list[n] points to string_start, make space for 16 more pointers */
1542 o->maxlen += 0x10 * sizeof(list[0]);
1543 o->data = xrealloc(o->data, o->maxlen + 1);
1544 list = (char**)o->data;
1545 memmove(list + n + 0x10, list + n, string_len);
1546 o->length += 0x10 * sizeof(list[0]);
1548 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1550 /* We have empty slot at list[n], reuse without growth */
1551 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1552 string_len = o->length - string_start;
1553 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1554 o->has_empty_slot = 0;
1556 list[n] = (char*)(ptrdiff_t)string_len;
1560 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1561 static int o_get_last_ptr(o_string *o, int n)
1563 char **list = (char**)o->data;
1564 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1566 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1569 /* o_glob performs globbing on last list[], saving each result
1570 * as a new list[]. */
1571 static int o_glob(o_string *o, int n)
1577 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1579 return o_save_ptr_helper(o, n);
1580 pattern = o->data + o_get_last_ptr(o, n);
1581 debug_printf_glob("glob pattern '%s'\n", pattern);
1582 if (!glob_needed(pattern)) {
1584 o->length = unbackslash(pattern) - o->data;
1585 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1586 return o_save_ptr_helper(o, n);
1589 memset(&globdata, 0, sizeof(globdata));
1590 gr = glob(pattern, 0, NULL, &globdata);
1591 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1592 if (gr == GLOB_NOSPACE)
1593 bb_error_msg_and_die("out of memory during glob");
1594 if (gr == GLOB_NOMATCH) {
1595 globfree(&globdata);
1598 if (gr != 0) { /* GLOB_ABORTED ? */
1599 //TODO: testcase for bad glob pattern behavior
1600 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1602 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1603 char **argv = globdata.gl_pathv;
1604 o->length = pattern - o->data; /* "forget" pattern */
1606 o_addstr(o, *argv, strlen(*argv) + 1);
1607 n = o_save_ptr_helper(o, n);
1613 globfree(&globdata);
1615 debug_print_list("o_glob returning", o, n);
1619 /* If o->o_glob == 1, glob the string so far remembered.
1620 * Otherwise, just finish current list[] and start new */
1621 static int o_save_ptr(o_string *o, int n)
1623 if (o->o_glob) { /* if globbing is requested */
1624 /* If o->has_empty_slot, list[n] was already globbed
1625 * (if it was requested back then when it was filled)
1626 * so don't do that again! */
1627 if (!o->has_empty_slot)
1628 return o_glob(o, n); /* o_save_ptr_helper is inside */
1630 return o_save_ptr_helper(o, n);
1633 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1634 static char **o_finalize_list(o_string *o, int n)
1639 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1641 debug_print_list("finalized", o, n);
1642 debug_printf_expand("finalized n:%d\n", n);
1643 list = (char**)o->data;
1644 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1648 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1654 /* expand_strvec_to_strvec() takes a list of strings, expands
1655 * all variable references within and returns a pointer to
1656 * a list of expanded strings, possibly with larger number
1657 * of strings. (Think VAR="a b"; echo $VAR).
1658 * This new list is allocated as a single malloc block.
1659 * NULL-terminated list of char* pointers is at the beginning of it,
1660 * followed by strings themself.
1661 * Caller can deallocate entire list by single free(list). */
1663 /* Store given string, finalizing the word and starting new one whenever
1664 * we encounter IFS char(s). This is used for expanding variable values.
1665 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1666 static int expand_on_ifs(o_string *output, int n, const char *str)
1669 int word_len = strcspn(str, G.ifs);
1671 if (output->o_quote || !output->o_glob)
1672 o_addQstr(output, str, word_len);
1673 else /* protect backslashes against globbing up :) */
1674 o_addstr_duplicate_backslash(output, str, word_len);
1677 if (!*str) /* EOL - do not finalize word */
1679 o_addchr(output, '\0');
1680 debug_print_list("expand_on_ifs", output, n);
1681 n = o_save_ptr(output, n);
1682 str += strspn(str, G.ifs); /* skip ifs chars */
1684 debug_print_list("expand_on_ifs[1]", output, n);
1688 #if ENABLE_HUSH_TICK
1689 static int process_command_subs(o_string *dest,
1690 struct in_str *input, const char *subst_end);
1693 /* Expand all variable references in given string, adding words to list[]
1694 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1695 * to be filled). This routine is extremely tricky: has to deal with
1696 * variables/parameters with whitespace, $* and $@, and constructs like
1697 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1698 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1700 /* or_mask is either 0 (normal case) or 0x80
1701 * (expansion of right-hand side of assignment == 1-element expand.
1702 * It will also do no globbing, and thus we must not backslash-quote!) */
1704 char first_ch, ored_ch;
1711 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1712 debug_print_list("expand_vars_to_list", output, n);
1713 n = o_save_ptr(output, n);
1714 debug_print_list("expand_vars_to_list[0]", output, n);
1716 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1717 #if ENABLE_HUSH_TICK
1718 o_string subst_result = NULL_O_STRING;
1720 o_addstr(output, arg, p - arg);
1721 debug_print_list("expand_vars_to_list[1]", output, n);
1723 p = strchr(p, SPECIAL_VAR_SYMBOL);
1725 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1726 /* "$@" is special. Even if quoted, it can still
1727 * expand to nothing (not even an empty string) */
1728 if ((first_ch & 0x7f) != '@')
1729 ored_ch |= first_ch;
1731 switch (first_ch & 0x7f) {
1732 /* Highest bit in first_ch indicates that var is double-quoted */
1734 val = utoa(G.root_pid);
1736 case '!': /* bg pid */
1737 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1739 case '?': /* exitcode */
1740 val = utoa(G.last_return_code);
1742 case '#': /* argc */
1743 if (arg[1] != SPECIAL_VAR_SYMBOL)
1744 /* actually, it's a ${#var} */
1746 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1751 if (!G.global_argv[i])
1753 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1754 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1755 smallint sv = output->o_quote;
1756 /* unquoted var's contents should be globbed, so don't quote */
1757 output->o_quote = 0;
1758 while (G.global_argv[i]) {
1759 n = expand_on_ifs(output, n, G.global_argv[i]);
1760 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1761 if (G.global_argv[i++][0] && G.global_argv[i]) {
1762 /* this argv[] is not empty and not last:
1763 * put terminating NUL, start new word */
1764 o_addchr(output, '\0');
1765 debug_print_list("expand_vars_to_list[2]", output, n);
1766 n = o_save_ptr(output, n);
1767 debug_print_list("expand_vars_to_list[3]", output, n);
1770 output->o_quote = sv;
1772 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1773 * and in this case should treat it like '$*' - see 'else...' below */
1774 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1776 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1777 if (++i >= G.global_argc)
1779 o_addchr(output, '\0');
1780 debug_print_list("expand_vars_to_list[4]", output, n);
1781 n = o_save_ptr(output, n);
1783 } else { /* quoted $*: add as one word */
1785 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1786 if (!G.global_argv[++i])
1789 o_addchr(output, G.ifs[0]);
1793 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1794 /* "Empty variable", used to make "" etc to not disappear */
1798 #if ENABLE_HUSH_TICK
1799 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1800 struct in_str input;
1803 //TODO: can we just stuff it into "output" directly?
1804 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1805 setup_string_in_str(&input, arg);
1806 process_command_subs(&subst_result, &input, NULL);
1807 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1808 val = subst_result.data;
1812 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1814 bool exp_len = false, exp_null = false;
1815 char *var = arg, exp_save, exp_op, *exp_word;
1818 arg[0] = first_ch & 0x7f;
1820 /* prepare for expansions */
1821 if (var[0] == '#') {
1822 /* handle length expansion ${#var} */
1826 /* maybe handle parameter expansion */
1827 exp_off = strcspn(var, ":-=+?");
1831 exp_save = var[exp_off];
1832 exp_null = exp_save == ':';
1833 exp_word = var + exp_off;
1834 if (exp_null) ++exp_word;
1835 exp_op = *exp_word++;
1836 var[exp_off] = '\0';
1840 /* lookup the variable in question */
1841 if (isdigit(var[0])) {
1842 /* handle_dollar() should have vetted var for us */
1844 if (i < G.global_argc)
1845 val = G.global_argv[i];
1846 /* else val remains NULL: $N with too big N */
1848 val = lookup_param(var);
1850 /* handle any expansions */
1852 debug_printf_expand("expand: length of '%s' = ", val);
1853 val = utoa(val ? strlen(val) : 0);
1854 debug_printf_expand("%s\n", val);
1855 } else if (exp_off) {
1856 /* we need to do an expansion */
1857 int exp_test = (!val || (exp_null && !val[0]));
1859 exp_test = !exp_test;
1860 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1861 exp_null ? "true" : "false", exp_test);
1864 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1868 if (exp_op == '=') {
1869 if (isdigit(var[0]) || var[0] == '#') {
1870 maybe_die(var, "special vars cannot assign in this way");
1873 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1874 sprintf(new_var, "%s=%s", var, val);
1875 set_local_var(new_var, -1);
1879 var[exp_off] = exp_save;
1884 #if ENABLE_HUSH_TICK
1887 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1888 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
1890 /* unquoted var's contents should be globbed, so don't quote */
1891 smallint sv = output->o_quote;
1892 output->o_quote = 0;
1893 n = expand_on_ifs(output, n, val);
1895 output->o_quote = sv;
1897 } else { /* quoted $VAR, val will be appended below */
1898 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
1903 o_addQstr(output, val, strlen(val));
1905 /* Do the check to avoid writing to a const string */
1906 if (p && *p != SPECIAL_VAR_SYMBOL)
1907 *p = SPECIAL_VAR_SYMBOL;
1909 #if ENABLE_HUSH_TICK
1910 o_free(&subst_result);
1913 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1916 debug_print_list("expand_vars_to_list[a]", output, n);
1917 /* this part is literal, and it was already pre-quoted
1918 * if needed (much earlier), do not use o_addQstr here! */
1919 o_addstr(output, arg, strlen(arg) + 1);
1920 debug_print_list("expand_vars_to_list[b]", output, n);
1921 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1922 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1925 /* allow to reuse list[n] later without re-growth */
1926 output->has_empty_slot = 1;
1928 o_addchr(output, '\0');
1933 static char **expand_variables(char **argv, int or_mask)
1938 o_string output = NULL_O_STRING;
1940 if (or_mask & 0x100) {
1941 output.o_quote = 1; /* protect against globbing for "$var" */
1942 /* (unquoted $var will temporarily switch it off) */
1949 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1952 debug_print_list("expand_variables", &output, n);
1954 /* output.data (malloced in one block) gets returned in "list" */
1955 list = o_finalize_list(&output, n);
1956 debug_print_strings("expand_variables[1]", list);
1960 static char **expand_strvec_to_strvec(char **argv)
1962 return expand_variables(argv, 0x100);
1965 /* Used for expansion of right hand of assignments */
1966 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1968 static char *expand_string_to_string(const char *str)
1970 char *argv[2], **list;
1972 argv[0] = (char*)str;
1974 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1976 if (!list[0] || list[1])
1977 bb_error_msg_and_die("BUG in varexp2");
1978 /* actually, just move string 2*sizeof(char*) bytes back */
1979 overlapping_strcpy((char*)list, list[0]);
1980 debug_printf_expand("string_to_string='%s'\n", (char*)list);
1984 /* Used for "eval" builtin */
1985 static char* expand_strvec_to_string(char **argv)
1989 list = expand_variables(argv, 0x80);
1990 /* Convert all NULs to spaces */
1995 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
1996 bb_error_msg_and_die("BUG in varexp3");
1997 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2001 overlapping_strcpy((char*)list, list[0]);
2002 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2006 static char **expand_assignments(char **argv, int count)
2010 /* Expand assignments into one string each */
2011 for (i = 0; i < count; i++) {
2012 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2018 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2019 * and stderr if they are redirected. */
2020 static int setup_redirects(struct command *prog, int squirrel[])
2023 struct redir_struct *redir;
2025 for (redir = prog->redirects; redir; redir = redir->next) {
2026 if (redir->dup == -1 && redir->rd_filename == NULL) {
2027 /* something went wrong in the parse. Pretend it didn't happen */
2030 if (redir->dup == -1) {
2032 mode = redir_table[redir->rd_type].mode;
2033 //TODO: check redir for names like '\\'
2034 p = expand_string_to_string(redir->rd_filename);
2035 openfd = open_or_warn(p, mode);
2038 /* this could get lost if stderr has been redirected, but
2039 bash and ash both lose it as well (though zsh doesn't!) */
2043 openfd = redir->dup;
2046 if (openfd != redir->fd) {
2047 if (squirrel && redir->fd < 3) {
2048 squirrel[redir->fd] = dup(redir->fd);
2051 //close(openfd); // close(-3) ??!
2053 dup2(openfd, redir->fd);
2054 if (redir->dup == -1)
2062 static void restore_redirects(int squirrel[])
2065 for (i = 0; i < 3; i++) {
2068 /* We simply die on error */
2075 #if !defined(DEBUG_CLEAN)
2076 #define free_pipe_list(head, indent) free_pipe_list(head)
2077 #define free_pipe(pi, indent) free_pipe(pi)
2079 static int free_pipe_list(struct pipe *head, int indent);
2081 /* return code is the exit status of the pipe */
2082 static int free_pipe(struct pipe *pi, int indent)
2085 struct command *command;
2086 struct redir_struct *r, *rnext;
2087 int a, i, ret_code = 0;
2089 if (pi->stopped_cmds > 0)
2091 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2092 for (i = 0; i < pi->num_cmds; i++) {
2093 command = &pi->cmds[i];
2094 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2095 if (command->argv) {
2096 for (a = 0, p = command->argv; *p; a++, p++) {
2097 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2099 free_strings(command->argv);
2100 command->argv = NULL;
2101 } else if (command->group) {
2102 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2103 ret_code = free_pipe_list(command->group, indent+3);
2104 debug_printf_clean("%s end group\n", indenter(indent));
2106 debug_printf_clean("%s (nil)\n", indenter(indent));
2108 for (r = command->redirects; r; r = rnext) {
2109 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2111 /* guard against the case >$FOO, where foo is unset or blank */
2112 if (r->rd_filename) {
2113 debug_printf_clean(" %s\n", r->rd_filename);
2114 free(r->rd_filename);
2115 r->rd_filename = NULL;
2118 debug_printf_clean("&%d\n", r->dup);
2123 command->redirects = NULL;
2125 free(pi->cmds); /* children are an array, they get freed all at once */
2134 static int free_pipe_list(struct pipe *head, int indent)
2136 int rcode = 0; /* if list has no members */
2137 struct pipe *pi, *next;
2139 for (pi = head; pi; pi = next) {
2141 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2143 rcode = free_pipe(pi, indent);
2144 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2146 /*pi->next = NULL;*/
2154 typedef struct nommu_save_t {
2160 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2161 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2162 #define pseudo_exec(nommu_save, command, argv_expanded) \
2163 pseudo_exec(command, argv_expanded)
2166 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2168 * XXX no exit() here. If you don't exec, use _exit instead.
2169 * The at_exit handlers apparently confuse the calling process,
2170 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2171 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2172 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2176 const struct built_in_command *x;
2178 /* If a variable is assigned in a forest, and nobody listens,
2179 * was it ever really set?
2181 if (!argv[assignment_cnt])
2182 _exit(EXIT_SUCCESS);
2184 new_env = expand_assignments(argv, assignment_cnt);
2186 putenv_all(new_env);
2187 free(new_env); /* optional */
2189 nommu_save->new_env = new_env;
2190 nommu_save->old_env = putenv_all_and_save_old(new_env);
2192 if (argv_expanded) {
2193 argv = argv_expanded;
2195 argv = expand_strvec_to_strvec(argv);
2197 nommu_save->argv = argv;
2202 * Check if the command matches any of the builtins.
2203 * Depending on context, this might be redundant. But it's
2204 * easier to waste a few CPU cycles than it is to figure out
2205 * if this is one of those cases.
2207 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2208 if (strcmp(argv[0], x->cmd) == 0) {
2209 debug_printf_exec("running builtin '%s'\n", argv[0]);
2210 rcode = x->function(argv);
2216 /* Check if the command matches any busybox applets */
2217 #if ENABLE_FEATURE_SH_STANDALONE
2218 if (strchr(argv[0], '/') == NULL) {
2219 int a = find_applet_by_name(argv[0]);
2221 if (APPLET_IS_NOEXEC(a)) {
2222 debug_printf_exec("running applet '%s'\n", argv[0]);
2223 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2224 run_applet_no_and_exit(a, argv);
2226 /* re-exec ourselves with the new arguments */
2227 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2228 execvp(bb_busybox_exec_path, argv);
2229 /* If they called chroot or otherwise made the binary no longer
2230 * executable, fall through */
2235 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2237 debug_printf_exec("execing '%s'\n", argv[0]);
2238 execvp(argv[0], argv);
2239 bb_perror_msg("can't exec '%s'", argv[0]);
2240 _exit(EXIT_FAILURE);
2243 static int run_list(struct pipe *pi);
2245 /* Called after [v]fork() in run_pipe()
2247 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2248 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2251 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2253 if (command->group) {
2255 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2258 debug_printf_exec("pseudo_exec: run_list\n");
2259 rcode = run_list(command->group);
2260 /* OK to leak memory by not calling free_pipe_list,
2261 * since this process is about to exit */
2266 /* Can happen. See what bash does with ">foo" by itself. */
2267 debug_printf("trying to pseudo_exec null command\n");
2268 _exit(EXIT_SUCCESS);
2272 static const char *get_cmdtext(struct pipe *pi)
2278 /* This is subtle. ->cmdtext is created only on first backgrounding.
2279 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2280 * On subsequent bg argv is trashed, but we won't use it */
2283 argv = pi->cmds[0].argv;
2284 if (!argv || !argv[0]) {
2285 pi->cmdtext = xzalloc(1);
2290 do len += strlen(*argv) + 1; while (*++argv);
2291 pi->cmdtext = p = xmalloc(len);
2292 argv = pi->cmds[0].argv;
2294 len = strlen(*argv);
2295 memcpy(p, *argv, len);
2303 static void insert_bg_job(struct pipe *pi)
2305 struct pipe *thejob;
2308 /* Linear search for the ID of the job to use */
2310 for (thejob = G.job_list; thejob; thejob = thejob->next)
2311 if (thejob->jobid >= pi->jobid)
2312 pi->jobid = thejob->jobid + 1;
2314 /* Add thejob to the list of running jobs */
2316 thejob = G.job_list = xmalloc(sizeof(*thejob));
2318 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2320 thejob->next = xmalloc(sizeof(*thejob));
2321 thejob = thejob->next;
2324 /* Physically copy the struct job */
2325 memcpy(thejob, pi, sizeof(struct pipe));
2326 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2327 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2328 for (i = 0; i < pi->num_cmds; i++) {
2329 // TODO: do we really need to have so many fields which are just dead weight
2330 // at execution stage?
2331 thejob->cmds[i].pid = pi->cmds[i].pid;
2332 /* all other fields are not used and stay zero */
2334 thejob->next = NULL;
2335 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2337 /* We don't wait for background thejobs to return -- append it
2338 to the list of backgrounded thejobs and leave it alone */
2339 if (G.interactive_fd)
2340 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2341 G.last_bg_pid = thejob->cmds[0].pid;
2342 G.last_jobid = thejob->jobid;
2345 static void remove_bg_job(struct pipe *pi)
2347 struct pipe *prev_pipe;
2349 if (pi == G.job_list) {
2350 G.job_list = pi->next;
2352 prev_pipe = G.job_list;
2353 while (prev_pipe->next != pi)
2354 prev_pipe = prev_pipe->next;
2355 prev_pipe->next = pi->next;
2358 G.last_jobid = G.job_list->jobid;
2363 /* Remove a backgrounded job */
2364 static void delete_finished_bg_job(struct pipe *pi)
2367 pi->stopped_cmds = 0;
2373 /* Check to see if any processes have exited -- if they
2374 * have, figure out why and see if a job has completed */
2375 static int checkjobs(struct pipe* fg_pipe)
2385 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2387 attributes = WUNTRACED;
2388 if (fg_pipe == NULL)
2389 attributes |= WNOHANG;
2391 /* Do we do this right?
2392 * bash-3.00# sleep 20 | false
2394 * [3]+ Stopped sleep 20 | false
2395 * bash-3.00# echo $?
2396 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2399 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2400 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2401 // + killall -STOP cat
2404 // TODO: safe_waitpid?
2405 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
2407 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
2409 if (WIFSTOPPED(status))
2410 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2411 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2412 if (WIFSIGNALED(status))
2413 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2414 childpid, WTERMSIG(status), WEXITSTATUS(status));
2415 if (WIFEXITED(status))
2416 debug_printf_jobs("pid %d exited, exitcode %d\n",
2417 childpid, WEXITSTATUS(status));
2419 /* Were we asked to wait for fg pipe? */
2421 for (i = 0; i < fg_pipe->num_cmds; i++) {
2422 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2423 if (fg_pipe->cmds[i].pid != childpid)
2425 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2427 fg_pipe->cmds[i].pid = 0;
2428 fg_pipe->alive_cmds--;
2429 if (i == fg_pipe->num_cmds - 1) {
2430 /* last process gives overall exitstatus */
2431 rcode = WEXITSTATUS(status);
2432 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2435 fg_pipe->cmds[i].is_stopped = 1;
2436 fg_pipe->stopped_cmds++;
2438 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2439 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2440 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2441 /* All processes in fg pipe have exited/stopped */
2443 if (fg_pipe->alive_cmds)
2444 insert_bg_job(fg_pipe);
2448 /* There are still running processes in the fg pipe */
2449 goto wait_more; /* do waitpid again */
2451 /* it wasnt fg_pipe, look for process in bg pipes */
2455 /* We asked to wait for bg or orphaned children */
2456 /* No need to remember exitcode in this case */
2457 for (pi = G.job_list; pi; pi = pi->next) {
2458 for (i = 0; i < pi->num_cmds; i++) {
2459 if (pi->cmds[i].pid == childpid)
2460 goto found_pi_and_prognum;
2463 /* Happens when shell is used as init process (init=/bin/sh) */
2464 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2465 continue; /* do waitpid again */
2467 found_pi_and_prognum:
2470 pi->cmds[i].pid = 0;
2472 if (!pi->alive_cmds) {
2473 if (G.interactive_fd)
2474 printf(JOB_STATUS_FORMAT, pi->jobid,
2475 "Done", pi->cmdtext);
2476 delete_finished_bg_job(pi);
2480 pi->cmds[i].is_stopped = 1;
2484 } /* while (waitpid succeeds)... */
2486 /* wait found no children or failed */
2488 if (childpid && errno != ECHILD)
2489 bb_perror_msg("waitpid");
2494 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2497 int rcode = checkjobs(fg_pipe);
2498 /* Job finished, move the shell to the foreground */
2499 p = getpgid(0); /* pgid of our process */
2500 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2501 tcsetpgrp(G.interactive_fd, p);
2506 /* run_pipe() starts all the jobs, but doesn't wait for anything
2507 * to finish. See checkjobs().
2509 * return code is normally -1, when the caller has to wait for children
2510 * to finish to determine the exit status of the pipe. If the pipe
2511 * is a simple builtin command, however, the action is done by the
2512 * time run_pipe returns, and the exit code is provided as the
2515 * The input of the pipe is always stdin, the output is always
2516 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2517 * because it tries to avoid running the command substitution in
2518 * subshell, when that is in fact necessary. The subshell process
2519 * now has its stdout directed to the input of the appropriate pipe,
2520 * so this routine is noticeably simpler.
2522 * Returns -1 only if started some children. IOW: we have to
2523 * mask out retvals of builtins etc with 0xff!
2525 static int run_pipe(struct pipe *pi)
2529 int pipefds[2]; /* pipefds[0] is for reading */
2530 struct command *command;
2531 char **argv_expanded;
2533 const struct built_in_command *x;
2535 /* it is not always needed, but we aim to smaller code */
2536 int squirrel[] = { -1, -1, -1 };
2538 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2540 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2546 pi->stopped_cmds = 0;
2548 /* Check if this is a simple builtin (not part of a pipe).
2549 * Builtins within pipes have to fork anyway, and are handled in
2550 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2552 command = &(pi->cmds[0]);
2554 #if ENABLE_HUSH_FUNCTIONS
2555 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2556 /* We "execute" function definition */
2557 bb_error_msg("here we ought to remember function definition, and go on");
2558 return EXIT_SUCCESS;
2562 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2563 debug_printf("non-subshell grouping\n");
2564 setup_redirects(command, squirrel);
2565 debug_printf_exec(": run_list\n");
2566 rcode = run_list(command->group) & 0xff;
2567 restore_redirects(squirrel);
2568 debug_printf_exec("run_pipe return %d\n", rcode);
2569 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2573 argv = command->argv;
2574 argv_expanded = NULL;
2576 if (single_and_fg && argv != NULL) {
2577 char **new_env = NULL;
2578 char **old_env = NULL;
2580 i = command->assignment_cnt;
2581 if (i != 0 && argv[i] == NULL) {
2582 /* assignments, but no command: set local environment */
2583 for (i = 0; argv[i] != NULL; i++) {
2584 debug_printf("local environment set: %s\n", argv[i]);
2585 p = expand_string_to_string(argv[i]);
2586 set_local_var(p, 0);
2588 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2591 /* Expand the rest into (possibly) many strings each */
2592 argv_expanded = expand_strvec_to_strvec(argv + i);
2594 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2595 if (strcmp(argv_expanded[0], x->cmd) != 0)
2597 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2598 debug_printf("exec with redirects only\n");
2599 setup_redirects(command, NULL);
2600 rcode = EXIT_SUCCESS;
2601 goto clean_up_and_ret1;
2603 debug_printf("builtin inline %s\n", argv_expanded[0]);
2604 /* XXX setup_redirects acts on file descriptors, not FILEs.
2605 * This is perfect for work that comes after exec().
2606 * Is it really safe for inline use? Experimentally,
2607 * things seem to work with glibc. */
2608 setup_redirects(command, squirrel);
2609 new_env = expand_assignments(argv, command->assignment_cnt);
2610 old_env = putenv_all_and_save_old(new_env);
2611 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2612 rcode = x->function(argv_expanded) & 0xff;
2613 #if ENABLE_FEATURE_SH_STANDALONE
2616 restore_redirects(squirrel);
2617 free_strings_and_unsetenv(new_env, 1);
2618 putenv_all(old_env);
2619 free(old_env); /* not free_strings()! */
2621 free(argv_expanded);
2622 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2623 debug_printf_exec("run_pipe return %d\n", rcode);
2626 #if ENABLE_FEATURE_SH_STANDALONE
2627 i = find_applet_by_name(argv_expanded[0]);
2628 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2629 setup_redirects(command, squirrel);
2630 save_nofork_data(&G.nofork_save);
2631 new_env = expand_assignments(argv, command->assignment_cnt);
2632 old_env = putenv_all_and_save_old(new_env);
2633 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2634 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2635 goto clean_up_and_ret;
2640 /* NB: argv_expanded may already be created, and that
2641 * might include `cmd` runs! Do not rerun it! We *must*
2642 * use argv_expanded if it's non-NULL */
2644 /* Disable job control signals for shell (parent) and
2645 * for initial child code after fork */
2646 //// set_jobctrl_sighandler(SIG_IGN);
2648 /* Going to fork a child per each pipe member */
2652 for (i = 0; i < pi->num_cmds; i++) {
2654 volatile nommu_save_t nommu_save;
2655 nommu_save.new_env = NULL;
2656 nommu_save.old_env = NULL;
2657 nommu_save.argv = NULL;
2659 command = &(pi->cmds[i]);
2660 if (command->argv) {
2661 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2663 debug_printf_exec(": pipe member with no argv\n");
2665 /* pipes are inserted between pairs of commands */
2668 if ((i + 1) < pi->num_cmds)
2671 command->pid = BB_MMU ? fork() : vfork();
2672 if (!command->pid) { /* child */
2674 die_sleep = 0; /* let nofork's xfuncs die */
2676 /* Every child adds itself to new process group
2677 * with pgid == pid_of_first_child_in_pipe */
2678 if (G.run_list_level == 1 && G.interactive_fd) {
2680 /* Don't do pgrp restore anymore on fatal signals */
2681 set_fatal_sighandler(SIG_DFL);
2683 if (pgrp < 0) /* true for 1st process only */
2685 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2686 /* We do it in *every* child, not just first,
2688 tcsetpgrp(G.interactive_fd, pgrp);
2692 xmove_fd(nextin, 0);
2693 xmove_fd(pipefds[1], 1); /* write end */
2695 close(pipefds[0]); /* read end */
2696 /* Like bash, explicit redirects override pipes,
2697 * and the pipe fd is available for dup'ing. */
2698 setup_redirects(command, NULL);
2700 /* Restore default handlers just prior to exec */
2701 //// set_jobctrl_sighandler(SIG_DFL);
2702 //// set_misc_sighandler(SIG_DFL);
2703 //// signal(SIGCHLD, SIG_DFL);
2704 /* Stores to nommu_save list of env vars putenv'ed
2705 * (NOMMU, on MMU we don't need that) */
2706 /* cast away volatility... */
2707 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2708 /* pseudo_exec() does not return */
2712 /* Clean up after vforked child */
2713 free(nommu_save.argv);
2714 free_strings_and_unsetenv(nommu_save.new_env, 1);
2715 putenv_all(nommu_save.old_env);
2717 free(argv_expanded);
2718 argv_expanded = NULL;
2719 if (command->pid < 0) { /* [v]fork failed */
2720 /* Clearly indicate, was it fork or vfork */
2721 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2725 /* Second and next children need to know pid of first one */
2727 pi->pgrp = command->pid;
2733 if ((i + 1) < pi->num_cmds)
2734 close(pipefds[1]); /* write end */
2735 /* Pass read (output) pipe end to next iteration */
2736 nextin = pipefds[0];
2739 if (!pi->alive_cmds) {
2740 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2744 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2748 #ifndef debug_print_tree
2749 static void debug_print_tree(struct pipe *pi, int lvl)
2751 static const char *const PIPE[] = {
2757 static const char *RES[] = {
2758 [RES_NONE ] = "NONE" ,
2761 [RES_THEN ] = "THEN" ,
2762 [RES_ELIF ] = "ELIF" ,
2763 [RES_ELSE ] = "ELSE" ,
2766 #if ENABLE_HUSH_LOOPS
2767 [RES_FOR ] = "FOR" ,
2768 [RES_WHILE] = "WHILE",
2769 [RES_UNTIL] = "UNTIL",
2771 [RES_DONE ] = "DONE" ,
2773 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2776 #if ENABLE_HUSH_CASE
2777 [RES_CASE ] = "CASE" ,
2778 [RES_MATCH] = "MATCH",
2779 [RES_CASEI] = "CASEI",
2780 [RES_ESAC ] = "ESAC" ,
2782 [RES_XXXX ] = "XXXX" ,
2783 [RES_SNTX ] = "SNTX" ,
2785 static const char *const GRPTYPE[] = {
2788 #if ENABLE_HUSH_FUNCTIONS
2797 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2798 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2800 while (prn < pi->num_cmds) {
2801 struct command *command = &pi->cmds[prn];
2802 char **argv = command->argv;
2804 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2805 if (command->group) {
2806 fprintf(stderr, " group %s: (argv=%p)\n",
2807 GRPTYPE[command->grp_type],
2809 debug_print_tree(command->group, lvl+1);
2813 if (argv) while (*argv) {
2814 fprintf(stderr, " '%s'", *argv);
2817 fprintf(stderr, "\n");
2826 /* NB: called by pseudo_exec, and therefore must not modify any
2827 * global data until exec/_exit (we can be a child after vfork!) */
2828 static int run_list(struct pipe *pi)
2830 #if ENABLE_HUSH_CASE
2831 char *case_word = NULL;
2833 #if ENABLE_HUSH_LOOPS
2834 struct pipe *loop_top = NULL;
2835 char *for_varname = NULL;
2836 char **for_lcur = NULL;
2837 char **for_list = NULL;
2839 smallint flag_skip = 1;
2840 smalluint rcode = 0; /* probably just for compiler */
2841 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2842 smalluint cond_code = 0;
2844 enum { cond_code = 0, };
2846 /*enum reserved_style*/ smallint rword = RES_NONE;
2847 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2849 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2851 #if ENABLE_HUSH_LOOPS
2852 /* Check syntax for "for" */
2853 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2854 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2856 /* current word is FOR or IN (BOLD in comments below) */
2857 if (cpipe->next == NULL) {
2858 syntax("malformed for");
2859 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2862 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2863 if (cpipe->next->res_word == RES_DO)
2865 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2866 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2867 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2869 syntax("malformed for");
2870 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2876 /* Past this point, all code paths should jump to ret: label
2877 * in order to return, no direct "return" statements please.
2878 * This helps to ensure that no memory is leaked. */
2880 //TODO: needs re-thinking
2883 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2884 * We are saving state before entering outermost list ("while...done")
2885 * so that ctrl-Z will correctly background _entire_ outermost list,
2886 * not just a part of it (like "sleep 1 | exit 2") */
2887 if (++G.run_list_level == 1 && G.interactive_fd) {
2888 if (sigsetjmp(G.toplevel_jb, 1)) {
2889 /* ctrl-Z forked and we are parent; or ctrl-C.
2890 * Sighandler has longjmped us here */
2891 signal(SIGINT, SIG_IGN);
2892 signal(SIGTSTP, SIG_IGN);
2893 /* Restore level (we can be coming from deep inside
2895 G.run_list_level = 1;
2896 #if ENABLE_FEATURE_SH_STANDALONE
2897 if (G.nofork_save.saved) { /* if save area is valid */
2898 debug_printf_jobs("exiting nofork early\n");
2899 restore_nofork_data(&G.nofork_save);
2902 //// if (G.ctrl_z_flag) {
2903 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2904 //// * Remember this child as background job */
2905 //// insert_bg_job(pi);
2907 /* ctrl-C. We just stop doing whatever we were doing */
2910 USE_HUSH_LOOPS(loop_top = NULL;)
2911 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2915 //// /* ctrl-Z handler will store pid etc in pi */
2916 //// G.toplevel_list = pi;
2917 //// G.ctrl_z_flag = 0;
2918 ////#if ENABLE_FEATURE_SH_STANDALONE
2919 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2921 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2922 //// signal(SIGINT, handler_ctrl_c);
2926 /* Go through list of pipes, (maybe) executing them. */
2927 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2928 IF_HAS_KEYWORDS(rword = pi->res_word;)
2929 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2930 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2931 rword, cond_code, skip_more_for_this_rword);
2932 #if ENABLE_HUSH_LOOPS
2933 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2934 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2936 /* start of a loop: remember where loop starts */
2941 if (rword == skip_more_for_this_rword && flag_skip) {
2942 if (pi->followup == PIPE_SEQ)
2944 /* it is "<false> && CMD" or "<true> || CMD"
2945 * and we should not execute CMD */
2949 skip_more_for_this_rword = RES_XXXX;
2952 if (rword == RES_THEN) {
2953 /* "if <false> THEN cmd": skip cmd */
2957 if (rword == RES_ELSE || rword == RES_ELIF) {
2958 /* "if <true> then ... ELSE/ELIF cmd":
2959 * skip cmd and all following ones */
2964 #if ENABLE_HUSH_LOOPS
2965 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
2967 /* first loop through for */
2969 static const char encoded_dollar_at[] ALIGN1 = {
2970 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
2971 }; /* encoded representation of "$@" */
2972 static const char *const encoded_dollar_at_argv[] = {
2973 encoded_dollar_at, NULL
2974 }; /* argv list with one element: "$@" */
2977 vals = (char**)encoded_dollar_at_argv;
2978 if (pi->next->res_word == RES_IN) {
2979 /* if no variable values after "in" we skip "for" */
2980 if (!pi->next->cmds[0].argv)
2982 vals = pi->next->cmds[0].argv;
2983 } /* else: "for var; do..." -> assume "$@" list */
2984 /* create list of variable values */
2985 debug_print_strings("for_list made from", vals);
2986 for_list = expand_strvec_to_strvec(vals);
2987 for_lcur = for_list;
2988 debug_print_strings("for_list", for_list);
2989 for_varname = pi->cmds[0].argv[0];
2990 pi->cmds[0].argv[0] = NULL;
2992 free(pi->cmds[0].argv[0]);
2994 /* "for" loop is over, clean up */
2998 pi->cmds[0].argv[0] = for_varname;
3001 /* insert next value from for_lcur */
3002 //TODO: does it need escaping?
3003 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3004 pi->cmds[0].assignment_cnt = 1;
3006 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
3008 if (rword == RES_DONE) {
3009 continue; /* "done" has no cmds too */
3012 #if ENABLE_HUSH_CASE
3013 if (rword == RES_CASE) {
3014 case_word = expand_strvec_to_string(pi->cmds->argv);
3017 if (rword == RES_MATCH) {
3020 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3022 /* all prev words didn't match, does this one match? */
3023 argv = pi->cmds->argv;
3025 char *pattern = expand_string_to_string(*argv);
3026 /* TODO: which FNM_xxx flags to use? */
3027 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3029 if (cond_code == 0) { /* match! we will execute this branch */
3030 free(case_word); /* make future "word)" stop */
3038 if (rword == RES_CASEI) { /* inside of a case branch */
3040 continue; /* not matched yet, skip this pipe */
3043 /* Just pressing <enter> in shell should check for jobs.
3044 * OTOH, in non-interactive shell this is useless
3045 * and only leads to extra job checks */
3046 if (pi->num_cmds == 0) {
3047 if (G.interactive_fd)
3048 goto check_jobs_and_continue;
3052 /* After analyzing all keywords and conditions, we decided
3053 * to execute this pipe. NB: have to do checkjobs(NULL)
3054 * after run_pipe() to collect any background children,
3055 * even if list execution is to be stopped. */
3056 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3059 #if ENABLE_HUSH_LOOPS
3060 G.flag_break_continue = 0;
3062 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3064 /* we only ran a builtin: rcode is already known
3065 * and we don't need to wait for anything. */
3066 check_and_run_traps();
3067 #if ENABLE_HUSH_LOOPS
3068 /* was it "break" or "continue"? */
3069 if (G.flag_break_continue) {
3070 smallint fbc = G.flag_break_continue;
3071 /* we might fall into outer *loop*,
3072 * don't want to break it too */
3074 G.depth_break_continue--;
3075 if (G.depth_break_continue == 0)
3076 G.flag_break_continue = 0;
3077 /* else: e.g. "continue 2" should *break* once, *then* continue */
3078 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3079 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3080 goto check_jobs_and_break;
3081 /* "continue": simulate end of loop */
3086 } else if (pi->followup == PIPE_BG) {
3087 /* what does bash do with attempts to background builtins? */
3088 /* even bash 3.2 doesn't do that well with nested bg:
3089 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3090 * I'm NOT treating inner &'s as jobs */
3091 check_and_run_traps();
3093 if (G.run_list_level == 1)
3096 rcode = 0; /* EXIT_SUCCESS */
3099 if (G.run_list_level == 1 && G.interactive_fd) {
3100 /* waits for completion, then fg's main shell */
3101 rcode = checkjobs_and_fg_shell(pi);
3102 check_and_run_traps();
3103 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3106 { /* this one just waits for completion */
3107 rcode = checkjobs(pi);
3108 check_and_run_traps();
3109 debug_printf_exec(": checkjobs returned %d\n", rcode);
3113 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3114 G.last_return_code = rcode;
3116 /* Analyze how result affects subsequent commands */
3118 if (rword == RES_IF || rword == RES_ELIF)
3121 #if ENABLE_HUSH_LOOPS
3122 if (rword == RES_WHILE) {
3124 rcode = 0; /* "while false; do...done" - exitcode 0 */
3125 goto check_jobs_and_break;
3128 if (rword == RES_UNTIL) {
3130 check_jobs_and_break:
3136 if ((rcode == 0 && pi->followup == PIPE_OR)
3137 || (rcode != 0 && pi->followup == PIPE_AND)
3139 skip_more_for_this_rword = rword;
3142 check_jobs_and_continue:
3147 //// if (G.ctrl_z_flag) {
3148 //// /* ctrl-Z forked somewhere in the past, we are the child,
3149 //// * and now we completed running the list. Exit. */
3155 //// if (!G.run_list_level && G.interactive_fd) {
3156 //// signal(SIGTSTP, SIG_IGN);
3157 //// signal(SIGINT, SIG_IGN);
3160 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3161 #if ENABLE_HUSH_LOOPS
3166 #if ENABLE_HUSH_CASE
3172 /* Select which version we will use */
3173 static int run_and_free_list(struct pipe *pi)
3176 debug_printf_exec("run_and_free_list entered\n");
3178 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3179 rcode = run_list(pi);
3181 /* free_pipe_list has the side effect of clearing memory.
3182 * In the long run that function can be merged with run_list,
3183 * but doing that now would hobble the debugging effort. */
3184 free_pipe_list(pi, /* indent: */ 0);
3185 debug_printf_exec("run_and_free_list return %d\n", rcode);
3190 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3191 * as in "2>&1", that represents duplicating a file descriptor.
3192 * Return either -2 (syntax error), -1 (no &), or the number found.
3194 static int redirect_dup_num(struct in_str *input)
3196 int ch, d = 0, ok = 0;
3198 if (ch != '&') return -1;
3200 i_getch(input); /* get the & */
3204 return -3; /* "-" represents "close me" */
3206 while (isdigit(ch)) {
3207 d = d*10 + (ch-'0');
3214 bb_error_msg("ambiguous redirect");
3218 /* The src parameter allows us to peek forward to a possible &n syntax
3219 * for file descriptor duplication, e.g., "2>&1".
3220 * Return code is 0 normally, 1 if a syntax error is detected in src.
3221 * Resource errors (in xmalloc) cause the process to exit */
3222 static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
3223 struct in_str *input)
3225 struct command *command = ctx->command;
3226 struct redir_struct *redir = command->redirects;
3227 struct redir_struct *last_redir = NULL;
3229 /* Create a new redir_struct and drop it onto the end of the linked list */
3232 redir = redir->next;
3234 redir = xzalloc(sizeof(struct redir_struct));
3235 /* redir->next = NULL; */
3236 /* redir->rd_filename = NULL; */
3238 last_redir->next = redir;
3240 command->redirects = redir;
3243 redir->rd_type = style;
3244 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3246 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3248 /* Check for a '2>&1' type redirect */
3249 redir->dup = redirect_dup_num(input);
3250 if (redir->dup == -2)
3251 return 1; /* syntax error */
3252 if (redir->dup != -1) {
3253 /* Erik had a check here that the file descriptor in question
3254 * is legit; I postpone that to "run time"
3255 * A "-" representation of "close me" shows up as a -3 here */
3256 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3258 /* We do _not_ try to open the file that src points to,
3259 * since we need to return and let src be expanded first.
3260 * Set ctx->pending_redirect, so we know what to do at the
3261 * end of the next parsed word. */
3262 ctx->pending_redirect = redir;
3268 static struct pipe *new_pipe(void)
3271 pi = xzalloc(sizeof(struct pipe));
3272 /*pi->followup = 0; - deliberately invalid value */
3273 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3277 /* Command (member of a pipe) is complete. The only possible error here
3278 * is out of memory, in which case xmalloc exits. */
3279 static int done_command(struct parse_context *ctx)
3281 /* The command is really already in the pipe structure, so
3282 * advance the pipe counter and make a new, null command. */
3283 struct pipe *pi = ctx->pipe;
3284 struct command *command = ctx->command;
3287 if (command->group == NULL
3288 && command->argv == NULL
3289 && command->redirects == NULL
3291 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3292 return pi->num_cmds;
3295 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3297 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3300 /* Only real trickiness here is that the uncommitted
3301 * command structure is not counted in pi->num_cmds. */
3302 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3303 command = &pi->cmds[pi->num_cmds];
3304 memset(command, 0, sizeof(*command));
3306 ctx->command = command;
3307 /* but ctx->pipe and ctx->list_head remain unchanged */
3309 return pi->num_cmds; /* used only for 0/nonzero check */
3312 static void done_pipe(struct parse_context *ctx, pipe_style type)
3316 debug_printf_parse("done_pipe entered, followup %d\n", type);
3317 /* Close previous command */
3318 not_null = done_command(ctx);
3319 ctx->pipe->followup = type;
3320 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3321 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3322 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3324 /* Without this check, even just <enter> on command line generates
3325 * tree of three NOPs (!). Which is harmless but annoying.
3326 * IOW: it is safe to do it unconditionally.
3327 * RES_NONE case is for "for a in; do ..." (empty IN set)
3328 * to work, possibly other cases too. */
3329 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3331 debug_printf_parse("done_pipe: adding new pipe: "
3332 "not_null:%d ctx->ctx_res_w:%d\n",
3333 not_null, ctx->ctx_res_w);
3335 ctx->pipe->next = new_p;
3337 ctx->command = NULL; /* needed! */
3338 /* RES_THEN, RES_DO etc are "sticky" -
3339 * they remain set for commands inside if/while.
3340 * This is used to control execution.
3341 * RES_FOR and RES_IN are NOT sticky (needed to support
3342 * cases where variable or value happens to match a keyword):
3344 #if ENABLE_HUSH_LOOPS
3345 if (ctx->ctx_res_w == RES_FOR
3346 || ctx->ctx_res_w == RES_IN)
3347 ctx->ctx_res_w = RES_NONE;
3349 #if ENABLE_HUSH_CASE
3350 if (ctx->ctx_res_w == RES_MATCH)
3351 ctx->ctx_res_w = RES_CASEI;
3353 /* Create the memory for command, roughly:
3354 * ctx->pipe->cmds = new struct command;
3355 * ctx->command = &ctx->pipe->cmds[0];
3359 debug_printf_parse("done_pipe return\n");
3362 static void initialize_context(struct parse_context *ctx)
3364 memset(ctx, 0, sizeof(*ctx));
3365 ctx->pipe = ctx->list_head = new_pipe();
3366 /* Create the memory for command, roughly:
3367 * ctx->pipe->cmds = new struct command;
3368 * ctx->command = &ctx->pipe->cmds[0];
3374 /* If a reserved word is found and processed, parse context is modified
3375 * and 1 is returned.
3376 * Handles if, then, elif, else, fi, for, while, until, do, done.
3377 * case, function, and select are obnoxious, save those for later.
3380 struct reserved_combo {
3383 unsigned char assignment_flag;
3387 FLAG_END = (1 << RES_NONE ),
3389 FLAG_IF = (1 << RES_IF ),
3390 FLAG_THEN = (1 << RES_THEN ),
3391 FLAG_ELIF = (1 << RES_ELIF ),
3392 FLAG_ELSE = (1 << RES_ELSE ),
3393 FLAG_FI = (1 << RES_FI ),
3395 #if ENABLE_HUSH_LOOPS
3396 FLAG_FOR = (1 << RES_FOR ),
3397 FLAG_WHILE = (1 << RES_WHILE),
3398 FLAG_UNTIL = (1 << RES_UNTIL),
3399 FLAG_DO = (1 << RES_DO ),
3400 FLAG_DONE = (1 << RES_DONE ),
3401 FLAG_IN = (1 << RES_IN ),
3403 #if ENABLE_HUSH_CASE
3404 FLAG_MATCH = (1 << RES_MATCH),
3405 FLAG_ESAC = (1 << RES_ESAC ),
3407 FLAG_START = (1 << RES_XXXX ),
3410 static const struct reserved_combo* match_reserved_word(o_string *word)
3412 /* Mostly a list of accepted follow-up reserved words.
3413 * FLAG_END means we are done with the sequence, and are ready
3414 * to turn the compound list into a command.
3415 * FLAG_START means the word must start a new compound list.
3417 static const struct reserved_combo reserved_list[] = {
3419 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3420 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3421 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3422 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3423 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3424 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3426 #if ENABLE_HUSH_LOOPS
3427 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3428 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3429 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3430 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3431 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3432 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3434 #if ENABLE_HUSH_CASE
3435 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3436 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3439 const struct reserved_combo *r;
3441 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3442 if (strcmp(word->data, r->literal) == 0)
3447 static int reserved_word(o_string *word, struct parse_context *ctx)
3449 #if ENABLE_HUSH_CASE
3450 static const struct reserved_combo reserved_match = {
3451 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3454 const struct reserved_combo *r;
3456 r = match_reserved_word(word);
3460 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3461 #if ENABLE_HUSH_CASE
3462 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3463 /* "case word IN ..." - IN part starts first match part */
3464 r = &reserved_match;
3467 if (r->flag == 0) { /* '!' */
3468 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3470 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3472 ctx->ctx_inverted = 1;
3475 if (r->flag & FLAG_START) {
3476 struct parse_context *new;
3477 debug_printf("push stack\n");
3478 new = xmalloc(sizeof(*new));
3479 *new = *ctx; /* physical copy */
3480 initialize_context(ctx);
3482 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3484 ctx->ctx_res_w = RES_SNTX;
3487 ctx->ctx_res_w = r->res;
3488 ctx->old_flag = r->flag;
3489 if (ctx->old_flag & FLAG_END) {
3490 struct parse_context *old;
3491 debug_printf("pop stack\n");
3492 done_pipe(ctx, PIPE_SEQ);
3494 old->command->group = ctx->list_head;
3495 old->command->grp_type = GRP_NORMAL;
3496 *ctx = *old; /* physical copy */
3499 word->o_assignment = r->assignment_flag;
3504 //TODO: many, many callers don't check error from done_word()
3506 /* Word is complete, look at it and update parsing context.
3507 * Normal return is 0. Syntax errors return 1. */
3508 static int done_word(o_string *word, struct parse_context *ctx)
3510 struct command *command = ctx->command;
3512 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3513 if (word->length == 0 && word->nonnull == 0) {
3514 debug_printf_parse("done_word return 0: true null, ignored\n");
3517 /* If this word wasn't an assignment, next ones definitely
3518 * can't be assignments. Even if they look like ones. */
3519 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3520 && word->o_assignment != WORD_IS_KEYWORD
3522 word->o_assignment = NOT_ASSIGNMENT;
3524 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3525 command->assignment_cnt++;
3526 word->o_assignment = MAYBE_ASSIGNMENT;
3529 if (ctx->pending_redirect) {
3530 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3531 * only if run as "bash", not "sh" */
3532 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3533 word->o_assignment = NOT_ASSIGNMENT;
3534 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3536 /* "{ echo foo; } echo bar" - bad */
3537 /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
3538 if (command->group) {
3540 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3544 #if ENABLE_HUSH_CASE
3545 if (ctx->ctx_dsemicolon
3546 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3548 /* already done when ctx_dsemicolon was set to 1: */
3549 /* ctx->ctx_res_w = RES_MATCH; */
3550 ctx->ctx_dsemicolon = 0;
3554 if (!command->argv /* if it's the first word... */
3555 #if ENABLE_HUSH_LOOPS
3556 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3557 && ctx->ctx_res_w != RES_IN
3560 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3561 if (reserved_word(word, ctx)) {
3563 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3564 return (ctx->ctx_res_w == RES_SNTX);
3568 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3569 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3570 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3571 /* (otherwise it's known to be not empty and is already safe) */
3573 /* exclude "$@" - it can expand to no word despite "" */
3574 char *p = word->data;
3575 while (p[0] == SPECIAL_VAR_SYMBOL
3576 && (p[1] & 0x7f) == '@'
3577 && p[2] == SPECIAL_VAR_SYMBOL
3581 if (p == word->data || p[0] != '\0') {
3582 /* saw no "$@", or not only "$@" but some
3583 * real text is there too */
3584 /* insert "empty variable" reference, this makes
3585 * e.g. "", $empty"" etc to not disappear */
3586 o_addchr(word, SPECIAL_VAR_SYMBOL);
3587 o_addchr(word, SPECIAL_VAR_SYMBOL);
3590 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3591 debug_print_strings("word appended to argv", command->argv);
3595 ctx->pending_redirect = NULL;
3597 #if ENABLE_HUSH_LOOPS
3598 /* Force FOR to have just one word (variable name) */
3599 /* NB: basically, this makes hush see "for v in ..." syntax as if
3600 * as it is "for v; in ...". FOR and IN become two pipe structs
3602 if (ctx->ctx_res_w == RES_FOR) {
3603 //TODO: check that command->argv[0] is a valid variable name!
3604 done_pipe(ctx, PIPE_SEQ);
3607 #if ENABLE_HUSH_CASE
3608 /* Force CASE to have just one word */
3609 if (ctx->ctx_res_w == RES_CASE) {
3610 done_pipe(ctx, PIPE_SEQ);
3613 debug_printf_parse("done_word return 0\n");
3617 /* If a redirect is immediately preceded by a number, that number is
3618 * supposed to tell which file descriptor to redirect. This routine
3619 * looks for such preceding numbers. In an ideal world this routine
3620 * needs to handle all the following classes of redirects...
3621 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3622 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3623 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3624 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3625 * A -1 output from this program means no valid number was found, so the
3626 * caller should use the appropriate default for this redirection.
3628 static int redirect_opt_num(o_string *o)
3634 for (num = 0; num < o->length; num++) {
3635 if (!isdigit(o->data[num])) {
3639 num = atoi(o->data);
3644 static int parse_stream(o_string *dest, struct parse_context *ctx,
3645 struct in_str *input0, const char *end_trigger);
3647 #if ENABLE_HUSH_TICK
3648 static FILE *generate_stream_from_list(struct pipe *head)
3651 int pid, channel[2];
3654 /* *** NOMMU WARNING *** */
3655 /* By using vfork here, we suspend parent till child exits or execs.
3656 * If child will not do it before it fills the pipe, it can block forever
3657 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3659 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3660 * huge=`cat TESTFILE` # will block here forever
3663 pid = BB_MMU ? fork() : vfork();
3665 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3666 if (pid == 0) { /* child */
3667 if (ENABLE_HUSH_JOB)
3668 die_sleep = 0; /* let nofork's xfuncs die */
3669 close(channel[0]); /* NB: close _first_, then move fd! */
3670 xmove_fd(channel[1], 1);
3671 /* Prevent it from trying to handle ctrl-z etc */
3673 G.run_list_level = 1;
3675 /* Process substitution is not considered to be usual
3676 * 'command execution'.
3677 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3678 //// /* Not needed, we are relying on it being disabled
3679 //// * everywhere outside actual command execution. */
3680 IGN_jobctrl_signals();
3681 //// set_misc_sighandler(SIG_DFL);
3682 /* Freeing 'head' here would break NOMMU. */
3683 _exit(run_list(head));
3686 pf = fdopen(channel[0], "r");
3688 /* 'head' is freed by the caller */
3691 /* Return code is exit status of the process that is run. */
3692 static int process_command_subs(o_string *dest,
3693 struct in_str *input,
3694 const char *subst_end)
3696 int retcode, ch, eol_cnt;
3697 o_string result = NULL_O_STRING;
3698 struct parse_context inner;
3700 struct in_str pipe_str;
3702 initialize_context(&inner);
3704 /* Recursion to generate command */
3705 retcode = parse_stream(&result, &inner, input, subst_end);
3707 return retcode; /* syntax error or EOF */
3708 done_word(&result, &inner);
3709 done_pipe(&inner, PIPE_SEQ);
3712 p = generate_stream_from_list(inner.list_head);
3715 close_on_exec_on(fileno(p));
3716 setup_file_in_str(&pipe_str, p);
3718 /* Now send results of command back into original context */
3720 while ((ch = i_getch(&pipe_str)) != EOF) {
3726 o_addchr(dest, '\n');
3729 o_addQchr(dest, ch);
3732 debug_printf("done reading from pipe, pclose()ing\n");
3733 /* This is the step that wait()s for the child. Should be pretty
3734 * safe, since we just read an EOF from its stdout. We could try
3735 * to do better, by using wait(), and keeping track of background jobs
3736 * at the same time. That would be a lot of work, and contrary
3737 * to the KISS philosophy of this program. */
3738 retcode = fclose(p);
3739 free_pipe_list(inner.list_head, /* indent: */ 0);
3740 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3745 static int parse_group(o_string *dest, struct parse_context *ctx,
3746 struct in_str *input, int ch)
3748 /* dest contains characters seen prior to ( or {.
3749 * Typically it's empty, but for functions defs,
3750 * it contains function name (without '()'). */
3752 const char *endch = NULL;
3753 struct parse_context sub;
3754 struct command *command = ctx->command;
3756 debug_printf_parse("parse_group entered\n");
3757 #if ENABLE_HUSH_FUNCTIONS
3758 if (ch == 'F') { /* function definition? */
3759 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3760 //command->fname = dest->data;
3761 command->grp_type = GRP_FUNCTION;
3762 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3763 memset(dest, 0, sizeof(*dest));
3766 if (command->argv /* word [word](... */
3767 || dest->length /* word(... */
3768 || dest->nonnull /* ""(... */
3771 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3774 initialize_context(&sub);
3778 command->grp_type = GRP_SUBSHELL;
3780 rcode = parse_stream(dest, &sub, input, endch);
3782 done_word(dest, &sub); /* finish off the final word in the subcontext */
3783 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3784 command->group = sub.list_head;
3786 debug_printf_parse("parse_group return %d\n", rcode);
3788 /* command remains "open", available for possible redirects */
3791 #if ENABLE_HUSH_TICK
3792 /* Subroutines for copying $(...) and `...` things */
3793 static void add_till_backquote(o_string *dest, struct in_str *input);
3795 static void add_till_single_quote(o_string *dest, struct in_str *input)
3798 int ch = i_getch(input);
3806 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3807 static void add_till_double_quote(o_string *dest, struct in_str *input)
3810 int ch = i_getch(input);
3813 if (ch == '\\') { /* \x. Copy both chars. */
3815 ch = i_getch(input);
3821 add_till_backquote(dest, input);
3825 //if (ch == '$') ...
3828 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3830 * "Within the backquoted style of command substitution, backslash
3831 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3832 * The search for the matching backquote shall be satisfied by the first
3833 * backquote found without a preceding backslash; during this search,
3834 * if a non-escaped backquote is encountered within a shell comment,
3835 * a here-document, an embedded command substitution of the $(command)
3836 * form, or a quoted string, undefined results occur. A single-quoted
3837 * or double-quoted string that begins, but does not end, within the
3838 * "`...`" sequence produces undefined results."
3840 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3842 static void add_till_backquote(o_string *dest, struct in_str *input)
3845 int ch = i_getch(input);
3848 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3849 int ch2 = i_getch(input);
3850 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3859 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3860 * quoting and nested ()s.
3861 * "With the $(command) style of command substitution, all characters
3862 * following the open parenthesis to the matching closing parenthesis
3863 * constitute the command. Any valid shell script can be used for command,
3864 * except a script consisting solely of redirections which produces
3865 * unspecified results."
3867 * echo $(echo '(TEST)' BEST) (TEST) BEST
3868 * echo $(echo 'TEST)' BEST) TEST) BEST
3869 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3871 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3875 int ch = i_getch(input);
3885 add_till_single_quote(dest, input);
3890 add_till_double_quote(dest, input);
3894 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3895 ch = i_getch(input);
3903 #endif /* ENABLE_HUSH_TICK */
3905 /* Return code: 0 for OK, 1 for syntax error */
3906 static int handle_dollar(o_string *dest, struct in_str *input)
3909 int ch = i_peek(input); /* first character after the $ */
3910 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3912 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3916 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3918 debug_printf_parse(": '%c'\n", ch);
3919 o_addchr(dest, ch | quote_mask);
3922 if (!isalnum(ch) && ch != '_')
3926 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3927 } else if (isdigit(ch)) {
3930 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3931 debug_printf_parse(": '%c'\n", ch);
3932 o_addchr(dest, ch | quote_mask);
3933 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3934 } else switch (ch) {
3936 case '!': /* last bg pid */
3937 case '?': /* last exit code */
3938 case '#': /* number of args */
3939 case '*': /* args */
3940 case '@': /* args */
3941 goto make_one_char_var;
3943 bool first_char, all_digits;
3945 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3947 /* XXX maybe someone will try to escape the '}' */
3952 ch = i_getch(input);
3958 /* ${#var}: length of var contents */
3960 else if (isdigit(ch)) {
3966 if (expansion < 2 &&
3967 ((all_digits && !isdigit(ch)) ||
3968 (!all_digits && !isalnum(ch) && ch != '_')))
3970 /* handle parameter expansions
3971 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3976 case ':': /* null modifier */
3977 if (expansion == 0) {
3978 debug_printf_parse(": null modifier\n");
3984 #if 0 /* not implemented yet :( */
3985 case '#': /* remove prefix */
3986 case '%': /* remove suffix */
3987 if (expansion == 0) {
3988 debug_printf_parse(": remove suffix/prefix\n");
3995 case '-': /* default value */
3996 case '=': /* assign default */
3997 case '+': /* alternative */
3998 case '?': /* error indicate */
3999 debug_printf_parse(": parameter expansion\n");
4005 syntax("unterminated ${name}");
4006 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4012 debug_printf_parse(": '%c'\n", ch);
4013 o_addchr(dest, ch | quote_mask);
4017 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4020 #if ENABLE_HUSH_TICK
4022 //int pos = dest->length;
4024 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4025 o_addchr(dest, quote_mask | '`');
4026 add_till_closing_curly_brace(dest, input);
4027 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4028 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4035 if (isalnum(ch)) { /* it's $_name or $_123 */
4041 /* still unhandled, but should be eventually */
4042 bb_error_msg("unhandled syntax: $%c", ch);
4046 o_addQchr(dest, '$');
4048 debug_printf_parse("handle_dollar return 0\n");
4052 /* Scan input, call done_word() whenever full IFS delimited word was seen.
4053 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
4054 * Return code is 0 if end_trigger char is met,
4055 * -1 on EOF (but if end_trigger == NULL then return 0),
4056 * 1 for syntax error */
4057 static int parse_stream(o_string *dest, struct parse_context *ctx,
4058 struct in_str *input, const char *end_trigger)
4062 redir_type redir_style;
4063 int shadow_quote = dest->o_quote;
4066 /* Only double-quote state is handled in the state variable dest->o_quote.
4067 * A single-quote triggers a bypass of the main loop until its mate is
4068 * found. When recursing, quote state is passed in via dest->o_quote. */
4070 debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
4075 ch = i_getch(input);
4079 next = i_peek(input);
4082 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
4083 ch, ch, m, dest->o_quote);
4084 if (m == CHAR_ORDINARY
4085 || (m != CHAR_SPECIAL && shadow_quote)
4088 syntax("unterminated \"");
4089 debug_printf_parse("parse_stream return 1: unterminated \"\n");
4092 o_addQchr(dest, ch);
4093 if ((dest->o_assignment == MAYBE_ASSIGNMENT
4094 || dest->o_assignment == WORD_IS_KEYWORD)
4096 && is_assignment(dest->data)
4098 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4102 if (m == CHAR_IFS) {
4103 if (done_word(dest, ctx)) {
4104 debug_printf_parse("parse_stream return 1: done_word!=0\n");
4109 /* If we aren't performing a substitution, treat
4110 * a newline as a command separator.
4111 * [why we don't handle it exactly like ';'? --vda] */
4112 if (end_trigger && ch == '\n') {
4113 #if ENABLE_HUSH_CASE
4114 /* "case ... in <newline> word) ..." -
4115 * newlines are ignored (but ';' wouldn't be) */
4116 if (dest->length == 0 // && argv[0] == NULL
4117 && ctx->ctx_res_w == RES_MATCH
4122 done_pipe(ctx, PIPE_SEQ);
4123 dest->o_assignment = MAYBE_ASSIGNMENT;
4127 if (!shadow_quote && strchr(end_trigger, ch)) {
4128 /* Special case: (...word) makes last word terminate,
4129 * as if ';' is seen */
4131 done_word(dest, ctx);
4133 done_pipe(ctx, PIPE_SEQ);
4134 dest->o_assignment = MAYBE_ASSIGNMENT;
4137 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
4139 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
4147 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
4148 /* ch is a special char and thus this word
4149 * cannot be an assignment: */
4150 dest->o_assignment = NOT_ASSIGNMENT;
4155 if (dest->length == 0 && !shadow_quote) {
4158 if (ch == EOF || ch == '\n')
4163 o_addQchr(dest, ch);
4169 debug_printf_parse("parse_stream return 1: \\<eof>\n");
4173 * "The backslash retains its special meaning [in "..."]
4174 * only when followed by one of the following characters:
4175 * $, `, ", \, or <newline>. A double quote may be quoted
4176 * within double quotes by preceding it with a backslash.
4177 * If enabled, history expansion will be performed unless
4178 * an ! appearing in double quotes is escaped using
4179 * a backslash. The backslash preceding the ! is not removed."
4181 if (shadow_quote) { //NOT SURE dest->o_quote) {
4182 if (strchr("$`\"\\", next) != NULL) {
4183 o_addqchr(dest, i_getch(input));
4185 o_addqchr(dest, '\\');
4188 o_addchr(dest, '\\');
4189 o_addchr(dest, i_getch(input));
4193 if (handle_dollar(dest, input) != 0) {
4194 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
4201 ch = i_getch(input);
4203 syntax("unterminated '");
4204 debug_printf_parse("parse_stream return 1: unterminated '\n");
4209 if (dest->o_assignment == NOT_ASSIGNMENT)
4210 o_addqchr(dest, ch);
4217 shadow_quote ^= 1; /* invert */
4218 if (dest->o_assignment == NOT_ASSIGNMENT)
4221 #if ENABLE_HUSH_TICK
4223 //int pos = dest->length;
4224 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4225 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
4226 add_till_backquote(dest, input);
4227 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4228 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4233 redir_fd = redirect_opt_num(dest);
4234 done_word(dest, ctx);
4235 redir_style = REDIRECT_OVERWRITE;
4237 redir_style = REDIRECT_APPEND;
4241 else if (next == '(') {
4242 syntax(">(process) not supported");
4243 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
4247 setup_redirect(ctx, redir_fd, redir_style, input);
4250 redir_fd = redirect_opt_num(dest);
4251 done_word(dest, ctx);
4252 redir_style = REDIRECT_INPUT;
4254 redir_style = REDIRECT_HEREIS;
4256 } else if (next == '>') {
4257 redir_style = REDIRECT_IO;
4261 else if (next == '(') {
4262 syntax("<(process) not supported");
4263 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
4267 setup_redirect(ctx, redir_fd, redir_style, input);
4270 #if ENABLE_HUSH_CASE
4273 done_word(dest, ctx);
4274 done_pipe(ctx, PIPE_SEQ);
4275 #if ENABLE_HUSH_CASE
4276 /* Eat multiple semicolons, detect
4277 * whether it means something special */
4283 if (ctx->ctx_res_w == RES_CASEI) {
4284 ctx->ctx_dsemicolon = 1;
4285 ctx->ctx_res_w = RES_MATCH;
4291 /* We just finished a cmd. New one may start
4292 * with an assignment */
4293 dest->o_assignment = MAYBE_ASSIGNMENT;
4296 done_word(dest, ctx);
4299 done_pipe(ctx, PIPE_AND);
4301 done_pipe(ctx, PIPE_BG);
4305 done_word(dest, ctx);
4306 #if ENABLE_HUSH_CASE
4307 if (ctx->ctx_res_w == RES_MATCH)
4308 break; /* we are in case's "word | word)" */
4310 if (next == '|') { /* || */
4312 done_pipe(ctx, PIPE_OR);
4314 /* we could pick up a file descriptor choice here
4315 * with redirect_opt_num(), but bash doesn't do it.
4316 * "echo foo 2| cat" yields "foo 2". */
4321 #if ENABLE_HUSH_CASE
4322 /* "case... in [(]word)..." - skip '(' */
4323 if (ctx->ctx_res_w == RES_MATCH
4324 && ctx->command->argv == NULL /* not (word|(... */
4325 && dest->length == 0 /* not word(... */
4326 && dest->nonnull == 0 /* not ""(... */
4331 #if ENABLE_HUSH_FUNCTIONS
4332 if (dest->length != 0 /* not just () but word() */
4333 && dest->nonnull == 0 /* not a"b"c() */
4334 && ctx->command->argv == NULL /* it's the first word */
4335 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4336 && i_peek(input) == ')'
4337 && !match_reserved_word(dest)
4339 bb_error_msg("seems like a function definition");
4342 //TODO: do it properly.
4343 ch = i_getch(input);
4344 } while (ch == ' ' || ch == '\n');
4346 syntax("was expecting {");
4347 debug_printf_parse("parse_stream return 1\n");
4350 ch = 'F'; /* magic value */
4354 if (parse_group(dest, ctx, input, ch) != 0) {
4355 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
4360 #if ENABLE_HUSH_CASE
4361 if (ctx->ctx_res_w == RES_MATCH)
4365 /* proper use of this character is caught by end_trigger:
4366 * if we see {, we call parse_group(..., end_trigger='}')
4367 * and it will match } earlier (not here). */
4368 syntax("unexpected } or )");
4369 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
4373 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4376 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
4382 static void set_in_charmap(const char *set, int code)
4385 G.charmap[(unsigned char)*set++] = code;
4388 static void update_charmap(void)
4390 G.ifs = getenv("IFS");
4393 /* Precompute a list of 'flow through' behavior so it can be treated
4394 * quickly up front. Computation is necessary because of IFS.
4395 * Special case handling of IFS == " \t\n" is not implemented.
4396 * The charmap[] array only really needs two bits each,
4397 * and on most machines that would be faster (reduced L1 cache use).
4399 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4400 #if ENABLE_HUSH_TICK
4401 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4403 set_in_charmap("\\$\"", CHAR_SPECIAL);
4405 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4406 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4409 /* Most recursion does not come through here, the exception is
4410 * from builtin_source() and builtin_eval() */
4411 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
4413 struct parse_context ctx;
4414 o_string temp = NULL_O_STRING;
4418 initialize_context(&ctx);
4420 #if ENABLE_HUSH_INTERACTIVE
4421 inp->promptmode = 0; /* PS1 */
4423 /* We will stop & execute after each ';' or '\n'.
4424 * Example: "sleep 9999; echo TEST" + ctrl-C:
4425 * TEST should be printed */
4426 temp.o_assignment = MAYBE_ASSIGNMENT;
4427 rcode = parse_stream(&temp, &ctx, inp, ";\n");
4429 if (rcode != 1 && ctx.old_flag != 0) {
4433 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
4434 done_word(&temp, &ctx);
4435 done_pipe(&ctx, PIPE_SEQ);
4436 debug_print_tree(ctx.list_head, 0);
4437 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
4438 run_and_free_list(ctx.list_head);
4440 /* We arrive here also if rcode == 1 (error in parse_stream) */
4442 if (ctx.old_flag != 0) {
4447 /*temp.nonnull = 0; - o_free does it below */
4448 /*temp.o_quote = 0; - o_free does it below */
4449 free_pipe_list(ctx.list_head, /* indent: */ 0);
4450 /* Discard all unprocessed line input, force prompt on */
4452 #if ENABLE_HUSH_INTERACTIVE
4457 /* loop on syntax errors, return on EOF: */
4458 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
4462 static int parse_and_run_string(const char *s, int parse_flag)
4464 struct in_str input;
4465 setup_string_in_str(&input, s);
4466 return parse_and_run_stream(&input, parse_flag);
4469 static int parse_and_run_file(FILE *f)
4472 struct in_str input;
4473 setup_file_in_str(&input, f);
4474 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
4479 /* Make sure we have a controlling tty. If we get started under a job
4480 * aware app (like bash for example), make sure we are now in charge so
4481 * we don't fight over who gets the foreground */
4482 static void setup_job_control(void)
4486 shell_pgrp = getpgrp();
4488 /* If we were ran as 'hush &',
4489 * sleep until we are in the foreground. */
4490 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4491 /* Send TTIN to ourself (should stop us) */
4492 kill(- shell_pgrp, SIGTTIN);
4493 shell_pgrp = getpgrp();
4496 /* Ignore job-control and misc signals. */
4497 //// set_jobctrl_sighandler(SIG_IGN);
4498 //// set_misc_sighandler(SIG_IGN);
4499 //huh? signal(SIGCHLD, SIG_IGN);
4501 /* We _must_ restore tty pgrp on fatal signals */
4502 set_fatal_sighandler(sigexit);
4504 /* Put ourselves in our own process group. */
4505 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4506 /* Grab control of the terminal. */
4507 tcsetpgrp(G.interactive_fd, getpid());
4511 static int set_mode(const char cstate, const char mode)
4513 int state = (cstate == '-' ? 1 : 0);
4515 case 'n': G.fake_mode = state; break;
4516 case 'x': /*G.debug_mode = state;*/ break;
4517 default: return EXIT_FAILURE;
4519 return EXIT_SUCCESS;
4522 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4523 int hush_main(int argc, char **argv)
4525 static const struct variable const_shell_ver = {
4527 .varstr = (char*)hush_version_str,
4528 .max_len = 1, /* 0 can provoke free(name) */
4536 struct variable *cur_var;
4540 G.root_pid = getpid();
4542 /* Deal with HUSH_VERSION */
4543 G.shell_ver = const_shell_ver; /* copying struct here */
4544 G.top_var = &G.shell_ver;
4545 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4546 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4547 /* Initialize our shell local variables with the values
4548 * currently living in the environment */
4549 cur_var = G.top_var;
4552 char *value = strchr(*e, '=');
4553 if (value) { /* paranoia */
4554 cur_var->next = xzalloc(sizeof(*cur_var));
4555 cur_var = cur_var->next;
4556 cur_var->varstr = *e;
4557 cur_var->max_len = strlen(*e);
4558 cur_var->flg_export = 1;
4562 debug_printf_env("putenv '%s'\n", hush_version_str);
4563 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4565 #if ENABLE_FEATURE_EDITING
4566 G.line_input_state = new_line_input_t(FOR_SHELL);
4568 /* XXX what should these be while sourcing /etc/profile? */
4569 G.global_argc = argc;
4570 G.global_argv = argv;
4571 /* Initialize some more globals to non-zero values */
4573 #if ENABLE_HUSH_INTERACTIVE
4574 if (ENABLE_FEATURE_EDITING)
4575 cmdedit_set_initial_prompt();
4579 if (EXIT_SUCCESS) /* otherwise is already done */
4580 G.last_return_code = EXIT_SUCCESS;
4582 if (argv[0] && argv[0][0] == '-') {
4583 debug_printf("sourcing /etc/profile\n");
4584 input = fopen_for_read("/etc/profile");
4585 if (input != NULL) {
4586 close_on_exec_on(fileno(input));
4587 parse_and_run_file(input);
4593 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4594 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4597 G.global_argv = argv + optind;
4598 if (!argv[optind]) {
4599 /* -c 'script' (no params): prevent empty $0 */
4600 *--G.global_argv = argv[0];
4602 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4603 G.global_argc = argc - optind;
4604 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
4607 /* Well, we cannot just declare interactiveness,
4608 * we have to have some stuff (ctty, etc) */
4609 /* G.interactive_fd++; */
4612 /* "-s" means "read from stdin", but this is how we always
4613 * operate, so simply do nothing here. */
4617 if (!set_mode('-', opt))
4621 fprintf(stderr, "Usage: sh [FILE]...\n"
4622 " or: sh -c command [args]...\n\n");
4630 /* A shell is interactive if the '-i' flag was given, or if all of
4631 * the following conditions are met:
4633 * no arguments remaining or the -s flag given
4634 * standard input is a terminal
4635 * standard output is a terminal
4636 * Refer to Posix.2, the description of the 'sh' utility. */
4637 if (argv[optind] == NULL && input == stdin
4638 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4640 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4641 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4642 if (G.saved_tty_pgrp >= 0) {
4643 /* try to dup to high fd#, >= 255 */
4644 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4645 if (G.interactive_fd < 0) {
4646 /* try to dup to any fd */
4647 G.interactive_fd = dup(STDIN_FILENO);
4648 if (G.interactive_fd < 0)
4650 G.interactive_fd = 0;
4652 // TODO: track & disallow any attempts of user
4653 // to (inadvertently) close/redirect it
4657 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4658 if (G.interactive_fd) {
4659 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4660 /* Looks like they want an interactive shell */
4661 setup_job_control();
4662 /* -1 is special - makes xfuncs longjmp, not exit
4663 * (we reset die_sleep = 0 whereever we [v]fork) */
4665 if (setjmp(die_jmp)) {
4666 /* xfunc has failed! die die die */
4667 hush_exit(xfunc_error_retval);
4670 #elif ENABLE_HUSH_INTERACTIVE
4671 /* no job control compiled, only prompt/line editing */
4672 if (argv[optind] == NULL && input == stdin
4673 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4675 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4676 if (G.interactive_fd < 0) {
4677 /* try to dup to any fd */
4678 G.interactive_fd = dup(STDIN_FILENO);
4679 if (G.interactive_fd < 0)
4681 G.interactive_fd = 0;
4683 if (G.interactive_fd) {
4684 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4685 //// set_misc_sighandler(SIG_IGN);
4691 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4692 if (G.interactive_fd) {
4693 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4694 printf("Enter 'help' for a list of built-in commands.\n\n");
4698 if (argv[optind] == NULL) {
4699 opt = parse_and_run_file(stdin);
4701 debug_printf("\nrunning script '%s'\n", argv[optind]);
4702 G.global_argv = argv + optind;
4703 G.global_argc = argc - optind;
4704 input = xfopen_for_read(argv[optind]);
4705 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4706 opt = parse_and_run_file(input);
4711 #if ENABLE_FEATURE_CLEAN_UP
4713 if (G.cwd != bb_msg_unknown)
4715 cur_var = G.top_var->next;
4717 struct variable *tmp = cur_var;
4718 if (!cur_var->max_len)
4719 free(cur_var->varstr);
4720 cur_var = cur_var->next;
4724 hush_exit(opt ? opt : G.last_return_code);
4729 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4730 int lash_main(int argc, char **argv)
4732 //bb_error_msg("lash is deprecated, please use hush instead");
4733 return hush_main(argc, argv);
4741 static int builtin_trap(char **argv)
4748 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4751 /* No args: print all trapped. This isn't 100% correct as we should
4752 * be escaping the cmd so that it can be pasted back in ...
4754 for (i = 0; i < NSIG; ++i)
4756 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4757 return EXIT_SUCCESS;
4762 /* if first arg is decimal: reset all specified */
4763 sig = bb_strtou(*++argv, NULL, 10);
4769 sig = get_signum(*argv++);
4770 if (sig < 0 || sig >= NSIG) {
4772 /* mimic bash message exactly */
4773 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4778 G.traps[sig] = xstrdup(new_cmd);
4780 debug_printf("trap: setting SIG%s (%i) to '%s'",
4781 get_signame(sig), sig, G.traps[sig]);
4783 /* There is no signal for 0 (EXIT) */
4788 sigaddset(&G.blocked_set, sig);
4790 /* there was a trap handler, we are removing it
4791 * (if sig has non-DFL handling,
4792 * we don't need to do anything) */
4793 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4795 sigdelset(&G.blocked_set, sig);
4797 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4802 /* first arg is "-": reset all specified to default */
4803 /* first arg is "": ignore all specified */
4804 /* everything else: execute first arg upon signal */
4806 bb_error_msg("trap: invalid arguments");
4807 return EXIT_FAILURE;
4809 if (LONE_DASH(*argv))
4817 static int builtin_true(char **argv UNUSED_PARAM)
4822 static int builtin_test(char **argv)
4829 return test_main(argc, argv - argc);
4832 static int builtin_echo(char **argv)
4839 return echo_main(argc, argv - argc);
4842 static int builtin_eval(char **argv)
4844 int rcode = EXIT_SUCCESS;
4847 char *str = expand_strvec_to_string(argv + 1);
4848 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4850 rcode = G.last_return_code;
4855 static int builtin_cd(char **argv)
4858 if (argv[1] == NULL) {
4859 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4860 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4861 newdir = getenv("HOME") ? : "/";
4864 if (chdir(newdir)) {
4865 printf("cd: %s: %s\n", newdir, strerror(errno));
4866 return EXIT_FAILURE;
4869 return EXIT_SUCCESS;
4872 static int builtin_exec(char **argv)
4874 if (argv[1] == NULL)
4875 return EXIT_SUCCESS; /* bash does this */
4880 // FIXME: if exec fails, bash does NOT exit! We do...
4881 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
4886 static int builtin_exit(char **argv)
4888 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4889 //puts("exit"); /* bash does it */
4890 // TODO: warn if we have background jobs: "There are stopped jobs"
4891 // On second consecutive 'exit', exit anyway.
4892 if (argv[1] == NULL)
4893 hush_exit(G.last_return_code);
4894 /* mimic bash: exit 123abc == exit 255 + error msg */
4895 xfunc_error_retval = 255;
4896 /* bash: exit -2 == exit 254, no error msg */
4897 hush_exit(xatoi(argv[1]) & 0xff);
4900 static int builtin_export(char **argv)
4903 char *name = argv[1];
4907 // ash emits: export VAR='VAL'
4908 // bash: declare -x VAR="VAL"
4909 // (both also escape as needed (quotes, $, etc))
4914 return EXIT_SUCCESS;
4917 value = strchr(name, '=');
4919 /* They are exporting something without a =VALUE */
4920 struct variable *var;
4922 var = get_local_var(name);
4924 var->flg_export = 1;
4925 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
4926 putenv(var->varstr);
4928 /* bash does not return an error when trying to export
4929 * an undefined variable. Do likewise. */
4930 return EXIT_SUCCESS;
4933 set_local_var(xstrdup(name), 1);
4934 return EXIT_SUCCESS;
4938 /* built-in 'fg' and 'bg' handler */
4939 static int builtin_fg_bg(char **argv)
4944 if (!G.interactive_fd)
4945 return EXIT_FAILURE;
4946 /* If they gave us no args, assume they want the last backgrounded task */
4948 for (pi = G.job_list; pi; pi = pi->next) {
4949 if (pi->jobid == G.last_jobid) {
4953 bb_error_msg("%s: no current job", argv[0]);
4954 return EXIT_FAILURE;
4956 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4957 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4958 return EXIT_FAILURE;
4960 for (pi = G.job_list; pi; pi = pi->next) {
4961 if (pi->jobid == jobnum) {
4965 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4966 return EXIT_FAILURE;
4968 // TODO: bash prints a string representation
4969 // of job being foregrounded (like "sleep 1 | cat")
4970 if (*argv[0] == 'f') {
4971 /* Put the job into the foreground. */
4972 tcsetpgrp(G.interactive_fd, pi->pgrp);
4975 /* Restart the processes in the job */
4976 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
4977 for (i = 0; i < pi->num_cmds; i++) {
4978 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
4979 pi->cmds[i].is_stopped = 0;
4981 pi->stopped_cmds = 0;
4983 i = kill(- pi->pgrp, SIGCONT);
4985 if (errno == ESRCH) {
4986 delete_finished_bg_job(pi);
4987 return EXIT_SUCCESS;
4989 bb_perror_msg("kill (SIGCONT)");
4993 if (*argv[0] == 'f') {
4995 return checkjobs_and_fg_shell(pi);
4997 return EXIT_SUCCESS;
5001 #if ENABLE_HUSH_HELP
5002 static int builtin_help(char **argv UNUSED_PARAM)
5004 const struct built_in_command *x;
5006 printf("\nBuilt-in commands:\n");
5007 printf("-------------------\n");
5008 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5009 printf("%s\t%s\n", x->cmd, x->descr);
5012 return EXIT_SUCCESS;
5017 static int builtin_jobs(char **argv UNUSED_PARAM)
5020 const char *status_string;
5022 for (job = G.job_list; job; job = job->next) {
5023 if (job->alive_cmds == job->stopped_cmds)
5024 status_string = "Stopped";
5026 status_string = "Running";
5028 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5030 return EXIT_SUCCESS;
5034 static int builtin_pwd(char **argv UNUSED_PARAM)
5037 return EXIT_SUCCESS;
5040 static int builtin_read(char **argv)
5043 const char *name = argv[1] ? argv[1] : "REPLY";
5045 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5046 return set_local_var(string, 0);
5049 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5050 * built-in 'set' handler
5052 * set [-abCefhmnuvx] [-o option] [argument...]
5053 * set [+abCefhmnuvx] [+o option] [argument...]
5054 * set -- [argument...]
5057 * Implementations shall support the options in both their hyphen and
5058 * plus-sign forms. These options can also be specified as options to sh.
5060 * Write out all variables and their values: set
5061 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5062 * Turn on the -x and -v options: set -xv
5063 * Unset all positional parameters: set --
5064 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5065 * Set the positional parameters to the expansion of x, even if x expands
5066 * with a leading '-' or '+': set -- $x
5068 * So far, we only support "set -- [argument...]" and some of the short names.
5070 static int builtin_set(char **argv)
5073 char **pp, **g_argv;
5074 char *arg = *++argv;
5078 for (e = G.top_var; e; e = e->next)
5080 return EXIT_SUCCESS;
5084 if (!strcmp(arg, "--")) {
5089 if (arg[0] == '+' || arg[0] == '-') {
5090 for (n = 1; arg[n]; ++n)
5091 if (set_mode(arg[0], arg[n]))
5097 } while ((arg = *++argv) != NULL);
5098 /* Now argv[0] is 1st argument */
5100 /* Only reset global_argv if we didn't process anything */
5102 return EXIT_SUCCESS;
5105 /* NB: G.global_argv[0] ($0) is never freed/changed */
5106 g_argv = G.global_argv;
5107 if (G.global_args_malloced) {
5113 G.global_args_malloced = 1;
5114 pp = xzalloc(sizeof(pp[0]) * 2);
5115 pp[0] = g_argv[0]; /* retain $0 */
5118 /* This realloc's G.global_argv */
5119 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5126 return EXIT_SUCCESS;
5128 /* Nothing known, so abort */
5130 bb_error_msg("set: %s: invalid option", arg);
5131 return EXIT_FAILURE;
5134 static int builtin_shift(char **argv)
5140 if (n >= 0 && n < G.global_argc) {
5141 if (G.global_args_malloced) {
5144 free(G.global_argv[m++]);
5147 memmove(&G.global_argv[1], &G.global_argv[n+1],
5148 G.global_argc * sizeof(G.global_argv[0]));
5149 return EXIT_SUCCESS;
5151 return EXIT_FAILURE;
5154 static int builtin_source(char **argv)
5159 if (argv[1] == NULL)
5160 return EXIT_FAILURE;
5162 /* XXX search through $PATH is missing */
5163 input = fopen_for_read(argv[1]);
5165 bb_error_msg("can't open '%s'", argv[1]);
5166 return EXIT_FAILURE;
5168 close_on_exec_on(fileno(input));
5170 /* Now run the file */
5171 /* XXX argv and argc are broken; need to save old G.global_argv
5172 * (pointer only is OK!) on this stack frame,
5173 * set G.global_argv=argv+1, recurse, and restore. */
5174 status = parse_and_run_file(input);
5179 static int builtin_umask(char **argv)
5182 const char *arg = argv[1];
5184 new_umask = bb_strtou(arg, NULL, 8);
5186 return EXIT_FAILURE;
5188 new_umask = umask(0);
5189 printf("%.3o\n", (unsigned) new_umask);
5192 return EXIT_SUCCESS;
5195 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5196 static int builtin_unset(char **argv)
5203 return EXIT_SUCCESS;
5206 if (argv[1][0] == '-') {
5207 switch (argv[1][1]) {
5209 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5211 bb_error_msg("unset: %s: invalid option", argv[1]);
5212 return EXIT_FAILURE;
5220 if (unset_local_var(argv[i]))
5223 #if ENABLE_HUSH_FUNCTIONS
5225 unset_local_func(argv[i]);
5231 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5232 static int builtin_wait(char **argv)
5234 int ret = EXIT_SUCCESS;
5237 if (*++argv == NULL)
5238 /* don't care about exit status */
5242 pid_t pid = bb_strtou(*argv, NULL, 10);
5244 /* mimic bash message */
5245 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5246 return EXIT_FAILURE;
5248 if (waitpid(pid, &status, 0) == pid) {
5249 if (WIFSIGNALED(status))
5250 ret = 128 + WTERMSIG(status);
5251 else if (WIFEXITED(status))
5252 ret = WEXITSTATUS(status);
5256 bb_perror_msg("wait %s", *argv);
5265 #if ENABLE_HUSH_LOOPS
5266 static int builtin_break(char **argv)
5268 if (G.depth_of_loop == 0) {
5269 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5270 return EXIT_SUCCESS; /* bash compat */
5272 G.flag_break_continue++; /* BC_BREAK = 1 */
5273 G.depth_break_continue = 1;
5275 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5276 if (errno || !G.depth_break_continue || argv[2]) {
5277 bb_error_msg("%s: bad arguments", argv[0]);
5278 G.flag_break_continue = BC_BREAK;
5279 G.depth_break_continue = UINT_MAX;
5282 if (G.depth_of_loop < G.depth_break_continue)
5283 G.depth_break_continue = G.depth_of_loop;
5284 return EXIT_SUCCESS;
5287 static int builtin_continue(char **argv)
5289 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5290 return builtin_break(argv);