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 smallint flag_SIGINT;
466 #if ENABLE_HUSH_LOOPS
467 smallint flag_break_continue;
470 /* These four support $?, $#, and $1 */
471 smalluint last_return_code;
472 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
473 smalluint global_args_malloced;
474 /* how many non-NULL argv's we have. NB: $# + 1 */
477 #if ENABLE_HUSH_LOOPS
478 unsigned depth_break_continue;
479 unsigned depth_of_loop;
483 struct variable *top_var; /* = &G.shell_ver (set in main()) */
484 struct variable shell_ver;
485 #if ENABLE_FEATURE_SH_STANDALONE
486 struct nofork_save_area nofork_save;
489 sigjmp_buf toplevel_jb;
491 unsigned char charmap[256];
492 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
493 /* Signal and trap handling */
494 char **traps; /* char *traps[NSIG] */
495 /* which signals have non-DFL handler (even with no traps set)? */
496 unsigned non_DFL_mask;
497 sigset_t blocked_set;
498 sigset_t inherited_set;
501 #define G (*ptr_to_globals)
502 /* Not #defining name to G.name - this quickly gets unwieldy
503 * (too many defines). Also, I actually prefer to see when a variable
504 * is global, thus "G." prefix is a useful hint */
505 #define INIT_G() do { \
506 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
510 /* Function prototypes for builtins */
511 static int builtin_cd(char **argv);
512 static int builtin_echo(char **argv);
513 static int builtin_eval(char **argv);
514 static int builtin_exec(char **argv);
515 static int builtin_exit(char **argv);
516 static int builtin_export(char **argv);
518 static int builtin_fg_bg(char **argv);
519 static int builtin_jobs(char **argv);
522 static int builtin_help(char **argv);
524 static int builtin_pwd(char **argv);
525 static int builtin_read(char **argv);
526 static int builtin_test(char **argv);
527 static int builtin_trap(char **argv);
528 static int builtin_true(char **argv);
529 static int builtin_set(char **argv);
530 static int builtin_shift(char **argv);
531 static int builtin_source(char **argv);
532 static int builtin_umask(char **argv);
533 static int builtin_unset(char **argv);
534 static int builtin_wait(char **argv);
535 #if ENABLE_HUSH_LOOPS
536 static int builtin_break(char **argv);
537 static int builtin_continue(char **argv);
539 //static int builtin_not_written(char **argv);
541 /* Table of built-in functions. They can be forked or not, depending on
542 * context: within pipes, they fork. As simple commands, they do not.
543 * When used in non-forking context, they can change global variables
544 * in the parent shell process. If forked, of course they cannot.
545 * For example, 'unset foo | whatever' will parse and run, but foo will
546 * still be set at the end. */
547 struct built_in_command {
549 int (*function)(char **argv);
552 #define BLTIN(cmd, func, help) { cmd, func, help }
554 #define BLTIN(cmd, func, help) { cmd, func }
558 /* For now, echo and test are unconditionally enabled.
559 * Maybe make it configurable? */
560 static const struct built_in_command bltins[] = {
561 BLTIN("." , builtin_source, "Run commands in a file"),
562 BLTIN(":" , builtin_true, "No-op"),
563 BLTIN("[" , builtin_test, "Test condition"),
565 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
567 #if ENABLE_HUSH_LOOPS
568 BLTIN("break" , builtin_break, "Exit from a loop"),
570 BLTIN("cd" , builtin_cd, "Change directory"),
571 #if ENABLE_HUSH_LOOPS
572 BLTIN("continue", builtin_continue, "Start new loop iteration"),
574 BLTIN("echo" , builtin_echo, "Write to stdout"),
575 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
576 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
577 BLTIN("exit" , builtin_exit, "Exit"),
578 BLTIN("export", builtin_export, "Set environment variable"),
580 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
581 BLTIN("jobs" , builtin_jobs, "List active jobs"),
583 BLTIN("pwd" , builtin_pwd, "Print current directory"),
584 BLTIN("read" , builtin_read, "Input environment variable"),
585 // BLTIN("return", builtin_not_written, "Return from a function"),
586 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
587 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
588 BLTIN("test" , builtin_test, "Test condition"),
589 BLTIN("trap" , builtin_trap, "Trap signals"),
590 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
591 BLTIN("umask" , builtin_umask, "Set file creation mask"),
592 BLTIN("unset" , builtin_unset, "Unset environment variable"),
593 BLTIN("wait" , builtin_wait, "Wait for process"),
595 BLTIN("help" , builtin_help, "List shell built-in commands"),
601 static void maybe_die(const char *notice, const char *msg)
603 /* Was using fancy stuff:
604 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
605 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
606 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
607 #if ENABLE_HUSH_INTERACTIVE
608 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
610 fp(msg ? "%s: %s" : notice, notice, msg);
613 #define syntax(msg) maybe_die("syntax error", msg);
615 /* Debug -- trick gcc to expand __LINE__ and convert to string */
616 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
617 #define _syntax(msg, line) __syntax(msg, line)
618 #define syntax(msg) _syntax(msg, __LINE__)
621 static int glob_needed(const char *s)
626 if (*s == '*' || *s == '[' || *s == '?')
633 static int is_assignment(const char *s)
635 if (!s || !(isalpha(*s) || *s == '_'))
638 while (isalnum(*s) || *s == '_')
643 /* Replace each \x with x in place, return ptr past NUL. */
644 static char *unbackslash(char *src)
650 if ((*dst++ = *src++) == '\0')
656 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
677 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
678 v[count1 + count2] = NULL;
681 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
685 static char **add_string_to_strings(char **strings, char *add)
690 return add_strings_to_strings(strings, v, /*dup:*/ 0);
693 static void putenv_all(char **strings)
698 debug_printf_env("putenv '%s'\n", *strings);
703 static char **putenv_all_and_save_old(char **strings)
713 eq = strchr(*strings, '=');
716 v = getenv(*strings);
719 /* v points to VAL in VAR=VAL, go back to VAR */
720 v -= (eq - *strings) + 1;
721 old = add_string_to_strings(old, v);
730 static void free_strings_and_unsetenv(char **strings, int unset)
740 debug_printf_env("unsetenv '%s'\n", *v);
748 static void free_strings(char **strings)
750 free_strings_and_unsetenv(strings, 0);
754 /* Basic theory of signal handling in shell
755 * ========================================
756 * This does not describe what hush does, rahter, it is current understanding
757 * what it _should_ do.
758 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
760 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
761 * is finished or backgrounded. It is the same in interactive and
762 * non-interactive shells, and is the same regardless of whether
763 * a user trap handler is installed or a default one is in effect.
764 * ^C or ^Z from keyboard seem to execute "at once" because it usually
765 * backgrounds (i.e. stops) or kills all members of currently running
768 * Wait builtin in interruptible by signals for which user trap is set
769 * or by SIGINT in interactive shell.
771 * Trap handlers will execute even within trap handlers. (right?)
773 * User trap handlers are forgotten when subshell is entered.
775 * If job control is off, backgrounded commands ("cmd &")
776 * have SIGINT, SIGQUIT set to SIG_IGN.
778 * Commands run in command substitution ("`cmd`")
779 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
781 * Ordinary commands have IGN/DFL set as inherited by the shell
784 * Default handlers which differ from DFL action
785 * (note: subshell is not an interactive shell):
788 * SIGTERM (interactive): ignore
789 * SUGHUP (interactive): send SIGCONT to stopped jobs,
790 * send SIGHUP to all jobs and exit
791 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
792 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
793 * that all pipe members are stopped) (right?)
794 * SIGINT (interactive): wait for last pipe, ignore the rest
795 * of the command line, show prompt. (check/expand this)
796 * Example 1: this waits 5 sec, but does not execute ls:
797 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
798 * Example 2: this does not wait and does not execute ls:
799 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
801 * (What happens to signals which are IGN on shell start?)
802 * (What happens with signal mask on shell start?)
804 * Implementation in hush
805 * ======================
806 * We use in-kernel pending signal mask to determine which signals were sent.
807 * We block all signals which we don't want to take action immediately,
808 * i.e. we block all signals which need to have special handling as described
809 * above, and all signals which have traps set.
810 * After each pipe execution, we extract any pending signals via sigtimedwait()
813 * unsigned non_DFL_mask: a mask of such "special" signals
814 * sigset_t blocked_set: current blocked signal set
816 * "trap - SIGxxx": clear bit in blocked_set unless it is also in non_DFL
817 * "trap 'cmd' SIGxxx": set bit in blocked_set (even if 'cmd' is '')
818 * after [v]fork, if we plan to be a shell:
819 * nothing for {} subshell (say, "true | { true; true; } | true")
820 * unset all traps if () shell. [TODO]
821 * after [v]fork, if we plan to exec:
822 * POSIX says pending signal mask is cleared in child - no need to clear it.
823 * restore blocked signal set to one inherited by shell just prior to exec.
825 * Note: as a result, we do not use signal handlers much. The only use
826 * is to restore terminal pgrp on exit.
828 * TODO: check/fix wait builtin to be interruptible.
831 /* called once at shell init */
832 static void init_signal_mask(void)
835 unsigned mask = (1 << SIGQUIT);
836 #if ENABLE_HUSH_INTERACTIVE
837 if (G.interactive_fd) {
843 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
849 G.non_DFL_mask = mask;
851 /*sigemptyset(&G.blocked_set); - already is */
852 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
856 sigaddset(&G.blocked_set, sig);
860 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
862 static void check_and_run_traps(void)
864 static const struct timespec zero_ts = { 0, 0 };
865 smalluint save_rcode;
869 sig = sigtimedwait(&G.blocked_set, NULL, &zero_ts);
873 if (G.traps && G.traps[sig]) {
874 if (G.traps[sig][0]) {
875 /* We have user-defined handler */
876 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
877 save_rcode = G.last_return_code;
880 G.last_return_code = save_rcode;
881 } /* else: "" trap, ignoring signal */
884 /* not a trap: special action */
892 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
900 /* Restores tty foreground process group, and exits.
901 * May be called as signal handler for fatal signal
902 * (will faithfully resend signal to itself, producing correct exit state)
903 * or called directly with -EXITCODE.
904 * We also call it if xfunc is exiting. */
905 static void sigexit(int sig) NORETURN;
906 static void sigexit(int sig)
908 /* Disable all signals: job control, SIGPIPE, etc. */
909 sigprocmask_allsigs(SIG_BLOCK);
911 #if ENABLE_HUSH_INTERACTIVE
912 /* Careful: we can end up here after [v]fork. Do not restore
913 * tty pgrp, only top-level shell process does that */
914 if (G.interactive_fd && getpid() == G.root_pid)
915 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
918 /* Not a signal, just exit */
922 kill_myself_with_sig(sig); /* does not return */
926 static void maybe_set_sighandler(int sig)
928 void (*handler)(int);
929 /* non_DFL_mask'ed signals are, well, masked,
930 * no need to set handler for them.
932 if (!((G.non_DFL_mask >> sig) & 1)) {
933 handler = signal(sig, sigexit);
934 if (handler == SIG_IGN) /* restore back to IGN! */
935 signal(sig, handler);
938 /* Used only to set handler to restore pgrp on exit, and to reset it to DFL */
939 static void set_fatal_signals_to_sigexit(void)
942 maybe_set_sighandler(SIGILL );
943 maybe_set_sighandler(SIGFPE );
944 maybe_set_sighandler(SIGBUS );
945 maybe_set_sighandler(SIGSEGV);
946 maybe_set_sighandler(SIGTRAP);
947 } /* else: hush is perfect. what SEGV? */
949 maybe_set_sighandler(SIGABRT);
951 /* bash 3.2 seems to handle these just like 'fatal' ones */
952 maybe_set_sighandler(SIGPIPE);
953 maybe_set_sighandler(SIGALRM);
954 maybe_set_sighandler(SIGHUP );
956 /* if we aren't interactive... but in this case
957 * we never want to restore pgrp on exit, and this fn is not called */
958 /*maybe_set_sighandler(SIGTERM);*/
959 /*maybe_set_sighandler(SIGINT );*/
961 /* Used only to suppress ^Z in `cmd` */
962 static void set_jobctrl_signals_to_IGN(void)
973 #define set_fatal_signals_to_sigexit(handler) ((void)0)
974 #define set_jobctrl_signals_to_IGN(handler) ((void)0)
978 /* Restores tty foreground process group, and exits. */
979 static void hush_exit(int exitcode) NORETURN;
980 static void hush_exit(int exitcode)
982 if (G.traps && G.traps[0] && G.traps[0][0]) {
983 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
989 fflush(NULL); /* flush all streams */
990 sigexit(- (exitcode & 0xff));
997 static const char *set_cwd(void)
999 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1000 * we must not try to free(bb_msg_unknown) */
1001 if (G.cwd == bb_msg_unknown)
1003 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1005 G.cwd = bb_msg_unknown;
1010 /* Get/check local shell variables */
1011 static struct variable *get_local_var(const char *name)
1013 struct variable *cur;
1019 for (cur = G.top_var; cur; cur = cur->next) {
1020 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1026 /* Basically useful version until someone wants to get fancier,
1027 * see the bash man page under "Parameter Expansion" */
1028 static const char *lookup_param(const char *src)
1030 struct variable *var = get_local_var(src);
1032 return strchr(var->varstr, '=') + 1;
1036 /* str holds "NAME=VAL" and is expected to be malloced.
1037 * We take ownership of it.
1038 * flg_export is used by:
1041 * -1: if NAME is set, leave export status alone
1042 * if NAME is not set, do not export
1044 static int set_local_var(char *str, int flg_export)
1046 struct variable *cur;
1050 value = strchr(str, '=');
1051 if (!value) { /* not expected to ever happen? */
1056 name_len = value - str + 1; /* including '=' */
1057 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1059 if (strncmp(cur->varstr, str, name_len) != 0) {
1061 /* Bail out. Note that now cur points
1062 * to last var in linked list */
1068 /* We found an existing var with this name */
1070 if (cur->flg_read_only) {
1071 bb_error_msg("%s: readonly variable", str);
1075 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1076 unsetenv(str); /* just in case */
1078 if (strcmp(cur->varstr, str) == 0) {
1083 if (cur->max_len >= strlen(str)) {
1084 /* This one is from startup env, reuse space */
1085 strcpy(cur->varstr, str);
1088 /* max_len == 0 signifies "malloced" var, which we can
1089 * (and has to) free */
1093 goto set_str_and_exp;
1096 /* Not found - create next variable struct */
1097 cur->next = xzalloc(sizeof(*cur));
1103 if (flg_export == 1)
1104 cur->flg_export = 1;
1105 if (cur->flg_export) {
1106 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1107 return putenv(cur->varstr);
1112 static int unset_local_var(const char *name)
1114 struct variable *cur;
1115 struct variable *prev = prev; /* for gcc */
1119 return EXIT_SUCCESS;
1120 name_len = strlen(name);
1123 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1124 if (cur->flg_read_only) {
1125 bb_error_msg("%s: readonly variable", name);
1126 return EXIT_FAILURE;
1128 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1129 * is ro, and we cannot reach this code on the 1st pass */
1130 prev->next = cur->next;
1131 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1132 bb_unsetenv(cur->varstr);
1136 return EXIT_SUCCESS;
1141 return EXIT_SUCCESS;
1148 static int static_get(struct in_str *i)
1151 if (ch == '\0') return EOF;
1155 static int static_peek(struct in_str *i)
1160 #if ENABLE_HUSH_INTERACTIVE
1162 static void cmdedit_set_initial_prompt(void)
1164 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1165 G.PS1 = getenv("PS1");
1172 static const char* setup_prompt_string(int promptmode)
1174 const char *prompt_str;
1175 debug_printf("setup_prompt_string %d ", promptmode);
1176 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1177 /* Set up the prompt */
1178 if (promptmode == 0) { /* PS1 */
1180 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1185 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1186 debug_printf("result '%s'\n", prompt_str);
1190 static void get_user_input(struct in_str *i)
1193 const char *prompt_str;
1195 prompt_str = setup_prompt_string(i->promptmode);
1196 #if ENABLE_FEATURE_EDITING
1197 /* Enable command line editing only while a command line
1198 * is actually being read */
1201 /* buglet: SIGINT will not make new prompt to appear _at once_,
1202 * only after <Enter>. (^C will work) */
1203 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1204 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1205 check_and_run_traps();
1206 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1207 i->eof_flag = (r < 0);
1208 if (i->eof_flag) { /* EOF/error detected */
1209 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1210 G.user_input_buf[1] = '\0';
1215 fputs(prompt_str, stdout);
1217 G.user_input_buf[0] = r = fgetc(i->file);
1218 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1219 //do we need check_and_run_traps()? (maybe only if stdin)
1220 } while (G.flag_SIGINT);
1221 i->eof_flag = (r == EOF);
1223 i->p = G.user_input_buf;
1226 #endif /* INTERACTIVE */
1228 /* This is the magic location that prints prompts
1229 * and gets data back from the user */
1230 static int file_get(struct in_str *i)
1234 /* If there is data waiting, eat it up */
1235 if (i->p && *i->p) {
1236 #if ENABLE_HUSH_INTERACTIVE
1240 if (i->eof_flag && !*i->p)
1243 /* need to double check i->file because we might be doing something
1244 * more complicated by now, like sourcing or substituting. */
1245 #if ENABLE_HUSH_INTERACTIVE
1246 if (G.interactive_fd && i->promptme && i->file == stdin) {
1249 } while (!*i->p); /* need non-empty line */
1250 i->promptmode = 1; /* PS2 */
1255 ch = fgetc(i->file);
1257 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1258 #if ENABLE_HUSH_INTERACTIVE
1265 /* All the callers guarantee this routine will never be
1266 * used right after a newline, so prompting is not needed.
1268 static int file_peek(struct in_str *i)
1271 if (i->p && *i->p) {
1272 if (i->eof_flag && !i->p[1])
1276 ch = fgetc(i->file);
1277 i->eof_flag = (ch == EOF);
1278 i->peek_buf[0] = ch;
1279 i->peek_buf[1] = '\0';
1281 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1285 static void setup_file_in_str(struct in_str *i, FILE *f)
1287 i->peek = file_peek;
1289 #if ENABLE_HUSH_INTERACTIVE
1291 i->promptmode = 0; /* PS1 */
1297 static void setup_string_in_str(struct in_str *i, const char *s)
1299 i->peek = static_peek;
1300 i->get = static_get;
1301 #if ENABLE_HUSH_INTERACTIVE
1303 i->promptmode = 0; /* PS1 */
1313 #define B_CHUNK (32 * sizeof(char*))
1315 static void o_reset(o_string *o)
1323 static void o_free(o_string *o)
1326 memset(o, 0, sizeof(*o));
1329 static void o_grow_by(o_string *o, int len)
1331 if (o->length + len > o->maxlen) {
1332 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1333 o->data = xrealloc(o->data, 1 + o->maxlen);
1337 static void o_addchr(o_string *o, int ch)
1339 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1341 o->data[o->length] = ch;
1343 o->data[o->length] = '\0';
1346 static void o_addstr(o_string *o, const char *str, int len)
1349 memcpy(&o->data[o->length], str, len);
1351 o->data[o->length] = '\0';
1354 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1359 && (*str != '*' && *str != '?' && *str != '[')
1367 /* My analysis of quoting semantics tells me that state information
1368 * is associated with a destination, not a source.
1370 static void o_addqchr(o_string *o, int ch)
1373 char *found = strchr("*?[\\", ch);
1378 o->data[o->length] = '\\';
1381 o->data[o->length] = ch;
1383 o->data[o->length] = '\0';
1386 static void o_addQchr(o_string *o, int ch)
1389 if (o->o_quote && strchr("*?[\\", ch)) {
1391 o->data[o->length] = '\\';
1395 o->data[o->length] = ch;
1397 o->data[o->length] = '\0';
1400 static void o_addQstr(o_string *o, const char *str, int len)
1403 o_addstr(o, str, len);
1409 int ordinary_cnt = strcspn(str, "*?[\\");
1410 if (ordinary_cnt > len) /* paranoia */
1412 o_addstr(o, str, ordinary_cnt);
1413 if (ordinary_cnt == len)
1415 str += ordinary_cnt;
1416 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1420 if (ch) { /* it is necessarily one of "*?[\\" */
1422 o->data[o->length] = '\\';
1426 o->data[o->length] = ch;
1428 o->data[o->length] = '\0';
1432 /* A special kind of o_string for $VAR and `cmd` expansion.
1433 * It contains char* list[] at the beginning, which is grown in 16 element
1434 * increments. Actual string data starts at the next multiple of 16 * (char*).
1435 * list[i] contains an INDEX (int!) into this string data.
1436 * It means that if list[] needs to grow, data needs to be moved higher up
1437 * but list[i]'s need not be modified.
1438 * NB: remembering how many list[i]'s you have there is crucial.
1439 * o_finalize_list() operation post-processes this structure - calculates
1440 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1442 #if DEBUG_EXPAND || DEBUG_GLOB
1443 static void debug_print_list(const char *prefix, o_string *o, int n)
1445 char **list = (char**)o->data;
1446 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1448 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1449 prefix, list, n, string_start, o->length, o->maxlen);
1451 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1452 o->data + (int)list[i] + string_start,
1453 o->data + (int)list[i] + string_start);
1457 const char *p = o->data + (int)list[n - 1] + string_start;
1458 fprintf(stderr, " total_sz:%ld\n", (p + strlen(p) + 1) - o->data);
1462 #define debug_print_list(prefix, o, n) ((void)0)
1465 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1466 * in list[n] so that it points past last stored byte so far.
1467 * It returns n+1. */
1468 static int o_save_ptr_helper(o_string *o, int n)
1470 char **list = (char**)o->data;
1474 if (!o->has_empty_slot) {
1475 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1476 string_len = o->length - string_start;
1477 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1478 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1479 /* list[n] points to string_start, make space for 16 more pointers */
1480 o->maxlen += 0x10 * sizeof(list[0]);
1481 o->data = xrealloc(o->data, o->maxlen + 1);
1482 list = (char**)o->data;
1483 memmove(list + n + 0x10, list + n, string_len);
1484 o->length += 0x10 * sizeof(list[0]);
1486 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1488 /* We have empty slot at list[n], reuse without growth */
1489 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1490 string_len = o->length - string_start;
1491 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1492 o->has_empty_slot = 0;
1494 list[n] = (char*)(ptrdiff_t)string_len;
1498 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1499 static int o_get_last_ptr(o_string *o, int n)
1501 char **list = (char**)o->data;
1502 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1504 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1507 /* o_glob performs globbing on last list[], saving each result
1508 * as a new list[]. */
1509 static int o_glob(o_string *o, int n)
1515 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1517 return o_save_ptr_helper(o, n);
1518 pattern = o->data + o_get_last_ptr(o, n);
1519 debug_printf_glob("glob pattern '%s'\n", pattern);
1520 if (!glob_needed(pattern)) {
1522 o->length = unbackslash(pattern) - o->data;
1523 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1524 return o_save_ptr_helper(o, n);
1527 memset(&globdata, 0, sizeof(globdata));
1528 gr = glob(pattern, 0, NULL, &globdata);
1529 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1530 if (gr == GLOB_NOSPACE)
1531 bb_error_msg_and_die("out of memory during glob");
1532 if (gr == GLOB_NOMATCH) {
1533 globfree(&globdata);
1536 if (gr != 0) { /* GLOB_ABORTED ? */
1537 //TODO: testcase for bad glob pattern behavior
1538 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1540 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1541 char **argv = globdata.gl_pathv;
1542 o->length = pattern - o->data; /* "forget" pattern */
1544 o_addstr(o, *argv, strlen(*argv) + 1);
1545 n = o_save_ptr_helper(o, n);
1551 globfree(&globdata);
1553 debug_print_list("o_glob returning", o, n);
1557 /* If o->o_glob == 1, glob the string so far remembered.
1558 * Otherwise, just finish current list[] and start new */
1559 static int o_save_ptr(o_string *o, int n)
1561 if (o->o_glob) { /* if globbing is requested */
1562 /* If o->has_empty_slot, list[n] was already globbed
1563 * (if it was requested back then when it was filled)
1564 * so don't do that again! */
1565 if (!o->has_empty_slot)
1566 return o_glob(o, n); /* o_save_ptr_helper is inside */
1568 return o_save_ptr_helper(o, n);
1571 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1572 static char **o_finalize_list(o_string *o, int n)
1577 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1579 debug_print_list("finalized", o, n);
1580 debug_printf_expand("finalized n:%d\n", n);
1581 list = (char**)o->data;
1582 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1586 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1592 /* expand_strvec_to_strvec() takes a list of strings, expands
1593 * all variable references within and returns a pointer to
1594 * a list of expanded strings, possibly with larger number
1595 * of strings. (Think VAR="a b"; echo $VAR).
1596 * This new list is allocated as a single malloc block.
1597 * NULL-terminated list of char* pointers is at the beginning of it,
1598 * followed by strings themself.
1599 * Caller can deallocate entire list by single free(list). */
1601 /* Store given string, finalizing the word and starting new one whenever
1602 * we encounter IFS char(s). This is used for expanding variable values.
1603 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1604 static int expand_on_ifs(o_string *output, int n, const char *str)
1607 int word_len = strcspn(str, G.ifs);
1609 if (output->o_quote || !output->o_glob)
1610 o_addQstr(output, str, word_len);
1611 else /* protect backslashes against globbing up :) */
1612 o_addstr_duplicate_backslash(output, str, word_len);
1615 if (!*str) /* EOL - do not finalize word */
1617 o_addchr(output, '\0');
1618 debug_print_list("expand_on_ifs", output, n);
1619 n = o_save_ptr(output, n);
1620 str += strspn(str, G.ifs); /* skip ifs chars */
1622 debug_print_list("expand_on_ifs[1]", output, n);
1626 #if ENABLE_HUSH_TICK
1627 static int process_command_subs(o_string *dest,
1628 struct in_str *input, const char *subst_end);
1631 /* Expand all variable references in given string, adding words to list[]
1632 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1633 * to be filled). This routine is extremely tricky: has to deal with
1634 * variables/parameters with whitespace, $* and $@, and constructs like
1635 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1636 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1638 /* or_mask is either 0 (normal case) or 0x80
1639 * (expansion of right-hand side of assignment == 1-element expand.
1640 * It will also do no globbing, and thus we must not backslash-quote!) */
1642 char first_ch, ored_ch;
1649 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1650 debug_print_list("expand_vars_to_list", output, n);
1651 n = o_save_ptr(output, n);
1652 debug_print_list("expand_vars_to_list[0]", output, n);
1654 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1655 #if ENABLE_HUSH_TICK
1656 o_string subst_result = NULL_O_STRING;
1658 o_addstr(output, arg, p - arg);
1659 debug_print_list("expand_vars_to_list[1]", output, n);
1661 p = strchr(p, SPECIAL_VAR_SYMBOL);
1663 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1664 /* "$@" is special. Even if quoted, it can still
1665 * expand to nothing (not even an empty string) */
1666 if ((first_ch & 0x7f) != '@')
1667 ored_ch |= first_ch;
1669 switch (first_ch & 0x7f) {
1670 /* Highest bit in first_ch indicates that var is double-quoted */
1672 val = utoa(G.root_pid);
1674 case '!': /* bg pid */
1675 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1677 case '?': /* exitcode */
1678 val = utoa(G.last_return_code);
1680 case '#': /* argc */
1681 if (arg[1] != SPECIAL_VAR_SYMBOL)
1682 /* actually, it's a ${#var} */
1684 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1689 if (!G.global_argv[i])
1691 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1692 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1693 smallint sv = output->o_quote;
1694 /* unquoted var's contents should be globbed, so don't quote */
1695 output->o_quote = 0;
1696 while (G.global_argv[i]) {
1697 n = expand_on_ifs(output, n, G.global_argv[i]);
1698 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1699 if (G.global_argv[i++][0] && G.global_argv[i]) {
1700 /* this argv[] is not empty and not last:
1701 * put terminating NUL, start new word */
1702 o_addchr(output, '\0');
1703 debug_print_list("expand_vars_to_list[2]", output, n);
1704 n = o_save_ptr(output, n);
1705 debug_print_list("expand_vars_to_list[3]", output, n);
1708 output->o_quote = sv;
1710 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1711 * and in this case should treat it like '$*' - see 'else...' below */
1712 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1714 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1715 if (++i >= G.global_argc)
1717 o_addchr(output, '\0');
1718 debug_print_list("expand_vars_to_list[4]", output, n);
1719 n = o_save_ptr(output, n);
1721 } else { /* quoted $*: add as one word */
1723 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1724 if (!G.global_argv[++i])
1727 o_addchr(output, G.ifs[0]);
1731 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1732 /* "Empty variable", used to make "" etc to not disappear */
1736 #if ENABLE_HUSH_TICK
1737 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1738 struct in_str input;
1741 //TODO: can we just stuff it into "output" directly?
1742 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1743 setup_string_in_str(&input, arg);
1744 process_command_subs(&subst_result, &input, NULL);
1745 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1746 val = subst_result.data;
1750 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1752 bool exp_len = false, exp_null = false;
1753 char *var = arg, exp_save, exp_op, *exp_word;
1756 arg[0] = first_ch & 0x7f;
1758 /* prepare for expansions */
1759 if (var[0] == '#') {
1760 /* handle length expansion ${#var} */
1764 /* maybe handle parameter expansion */
1765 exp_off = strcspn(var, ":-=+?");
1769 exp_save = var[exp_off];
1770 exp_null = exp_save == ':';
1771 exp_word = var + exp_off;
1772 if (exp_null) ++exp_word;
1773 exp_op = *exp_word++;
1774 var[exp_off] = '\0';
1778 /* lookup the variable in question */
1779 if (isdigit(var[0])) {
1780 /* handle_dollar() should have vetted var for us */
1782 if (i < G.global_argc)
1783 val = G.global_argv[i];
1784 /* else val remains NULL: $N with too big N */
1786 val = lookup_param(var);
1788 /* handle any expansions */
1790 debug_printf_expand("expand: length of '%s' = ", val);
1791 val = utoa(val ? strlen(val) : 0);
1792 debug_printf_expand("%s\n", val);
1793 } else if (exp_off) {
1794 /* we need to do an expansion */
1795 int exp_test = (!val || (exp_null && !val[0]));
1797 exp_test = !exp_test;
1798 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1799 exp_null ? "true" : "false", exp_test);
1802 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1806 if (exp_op == '=') {
1807 if (isdigit(var[0]) || var[0] == '#') {
1808 maybe_die(var, "special vars cannot assign in this way");
1811 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1812 sprintf(new_var, "%s=%s", var, val);
1813 set_local_var(new_var, -1);
1817 var[exp_off] = exp_save;
1822 #if ENABLE_HUSH_TICK
1825 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1826 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
1828 /* unquoted var's contents should be globbed, so don't quote */
1829 smallint sv = output->o_quote;
1830 output->o_quote = 0;
1831 n = expand_on_ifs(output, n, val);
1833 output->o_quote = sv;
1835 } else { /* quoted $VAR, val will be appended below */
1836 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
1841 o_addQstr(output, val, strlen(val));
1843 /* Do the check to avoid writing to a const string */
1844 if (p && *p != SPECIAL_VAR_SYMBOL)
1845 *p = SPECIAL_VAR_SYMBOL;
1847 #if ENABLE_HUSH_TICK
1848 o_free(&subst_result);
1851 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1854 debug_print_list("expand_vars_to_list[a]", output, n);
1855 /* this part is literal, and it was already pre-quoted
1856 * if needed (much earlier), do not use o_addQstr here! */
1857 o_addstr(output, arg, strlen(arg) + 1);
1858 debug_print_list("expand_vars_to_list[b]", output, n);
1859 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1860 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1863 /* allow to reuse list[n] later without re-growth */
1864 output->has_empty_slot = 1;
1866 o_addchr(output, '\0');
1871 static char **expand_variables(char **argv, int or_mask)
1876 o_string output = NULL_O_STRING;
1878 if (or_mask & 0x100) {
1879 output.o_quote = 1; /* protect against globbing for "$var" */
1880 /* (unquoted $var will temporarily switch it off) */
1887 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1890 debug_print_list("expand_variables", &output, n);
1892 /* output.data (malloced in one block) gets returned in "list" */
1893 list = o_finalize_list(&output, n);
1894 debug_print_strings("expand_variables[1]", list);
1898 static char **expand_strvec_to_strvec(char **argv)
1900 return expand_variables(argv, 0x100);
1903 /* Used for expansion of right hand of assignments */
1904 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1906 static char *expand_string_to_string(const char *str)
1908 char *argv[2], **list;
1910 argv[0] = (char*)str;
1912 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1914 if (!list[0] || list[1])
1915 bb_error_msg_and_die("BUG in varexp2");
1916 /* actually, just move string 2*sizeof(char*) bytes back */
1917 overlapping_strcpy((char*)list, list[0]);
1918 debug_printf_expand("string_to_string='%s'\n", (char*)list);
1922 /* Used for "eval" builtin */
1923 static char* expand_strvec_to_string(char **argv)
1927 list = expand_variables(argv, 0x80);
1928 /* Convert all NULs to spaces */
1933 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
1934 bb_error_msg_and_die("BUG in varexp3");
1935 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
1939 overlapping_strcpy((char*)list, list[0]);
1940 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
1944 static char **expand_assignments(char **argv, int count)
1948 /* Expand assignments into one string each */
1949 for (i = 0; i < count; i++) {
1950 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
1956 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1957 * and stderr if they are redirected. */
1958 static int setup_redirects(struct command *prog, int squirrel[])
1961 struct redir_struct *redir;
1963 for (redir = prog->redirects; redir; redir = redir->next) {
1964 if (redir->dup == -1 && redir->rd_filename == NULL) {
1965 /* something went wrong in the parse. Pretend it didn't happen */
1968 if (redir->dup == -1) {
1970 mode = redir_table[redir->rd_type].mode;
1971 //TODO: check redir for names like '\\'
1972 p = expand_string_to_string(redir->rd_filename);
1973 openfd = open_or_warn(p, mode);
1976 /* this could get lost if stderr has been redirected, but
1977 bash and ash both lose it as well (though zsh doesn't!) */
1981 openfd = redir->dup;
1984 if (openfd != redir->fd) {
1985 if (squirrel && redir->fd < 3) {
1986 squirrel[redir->fd] = dup(redir->fd);
1989 //close(openfd); // close(-3) ??!
1991 dup2(openfd, redir->fd);
1992 if (redir->dup == -1)
2000 static void restore_redirects(int squirrel[])
2003 for (i = 0; i < 3; i++) {
2006 /* We simply die on error */
2013 #if !defined(DEBUG_CLEAN)
2014 #define free_pipe_list(head, indent) free_pipe_list(head)
2015 #define free_pipe(pi, indent) free_pipe(pi)
2017 static int free_pipe_list(struct pipe *head, int indent);
2019 /* return code is the exit status of the pipe */
2020 static int free_pipe(struct pipe *pi, int indent)
2023 struct command *command;
2024 struct redir_struct *r, *rnext;
2025 int a, i, ret_code = 0;
2027 if (pi->stopped_cmds > 0)
2029 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2030 for (i = 0; i < pi->num_cmds; i++) {
2031 command = &pi->cmds[i];
2032 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2033 if (command->argv) {
2034 for (a = 0, p = command->argv; *p; a++, p++) {
2035 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2037 free_strings(command->argv);
2038 command->argv = NULL;
2039 } else if (command->group) {
2040 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2041 ret_code = free_pipe_list(command->group, indent+3);
2042 debug_printf_clean("%s end group\n", indenter(indent));
2044 debug_printf_clean("%s (nil)\n", indenter(indent));
2046 for (r = command->redirects; r; r = rnext) {
2047 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2049 /* guard against the case >$FOO, where foo is unset or blank */
2050 if (r->rd_filename) {
2051 debug_printf_clean(" %s\n", r->rd_filename);
2052 free(r->rd_filename);
2053 r->rd_filename = NULL;
2056 debug_printf_clean("&%d\n", r->dup);
2061 command->redirects = NULL;
2063 free(pi->cmds); /* children are an array, they get freed all at once */
2072 static int free_pipe_list(struct pipe *head, int indent)
2074 int rcode = 0; /* if list has no members */
2075 struct pipe *pi, *next;
2077 for (pi = head; pi; pi = next) {
2079 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2081 rcode = free_pipe(pi, indent);
2082 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2084 /*pi->next = NULL;*/
2092 typedef struct nommu_save_t {
2098 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2099 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2100 #define pseudo_exec(nommu_save, command, argv_expanded) \
2101 pseudo_exec(command, argv_expanded)
2104 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2106 * XXX no exit() here. If you don't exec, use _exit instead.
2107 * The at_exit handlers apparently confuse the calling process,
2108 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2109 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2110 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2114 const struct built_in_command *x;
2116 /* If a variable is assigned in a forest, and nobody listens,
2117 * was it ever really set?
2119 if (!argv[assignment_cnt])
2120 _exit(EXIT_SUCCESS);
2122 new_env = expand_assignments(argv, assignment_cnt);
2124 putenv_all(new_env);
2125 free(new_env); /* optional */
2127 nommu_save->new_env = new_env;
2128 nommu_save->old_env = putenv_all_and_save_old(new_env);
2130 if (argv_expanded) {
2131 argv = argv_expanded;
2133 argv = expand_strvec_to_strvec(argv);
2135 nommu_save->argv = argv;
2140 * Check if the command matches any of the builtins.
2141 * Depending on context, this might be redundant. But it's
2142 * easier to waste a few CPU cycles than it is to figure out
2143 * if this is one of those cases.
2145 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2146 if (strcmp(argv[0], x->cmd) == 0) {
2147 debug_printf_exec("running builtin '%s'\n", argv[0]);
2148 rcode = x->function(argv);
2154 /* Check if the command matches any busybox applets */
2155 #if ENABLE_FEATURE_SH_STANDALONE
2156 if (strchr(argv[0], '/') == NULL) {
2157 int a = find_applet_by_name(argv[0]);
2159 if (APPLET_IS_NOEXEC(a)) {
2160 debug_printf_exec("running applet '%s'\n", argv[0]);
2161 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2162 run_applet_no_and_exit(a, argv);
2164 /* re-exec ourselves with the new arguments */
2165 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2166 execvp(bb_busybox_exec_path, argv);
2167 /* If they called chroot or otherwise made the binary no longer
2168 * executable, fall through */
2173 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2175 debug_printf_exec("execing '%s'\n", argv[0]);
2176 execvp(argv[0], argv);
2177 bb_perror_msg("can't exec '%s'", argv[0]);
2178 _exit(EXIT_FAILURE);
2181 static int run_list(struct pipe *pi);
2183 /* Called after [v]fork() in run_pipe()
2185 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2186 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2189 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2191 if (command->group) {
2193 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2196 debug_printf_exec("pseudo_exec: run_list\n");
2197 rcode = run_list(command->group);
2198 /* OK to leak memory by not calling free_pipe_list,
2199 * since this process is about to exit */
2204 /* Can happen. See what bash does with ">foo" by itself. */
2205 debug_printf("trying to pseudo_exec null command\n");
2206 _exit(EXIT_SUCCESS);
2210 static const char *get_cmdtext(struct pipe *pi)
2216 /* This is subtle. ->cmdtext is created only on first backgrounding.
2217 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2218 * On subsequent bg argv is trashed, but we won't use it */
2221 argv = pi->cmds[0].argv;
2222 if (!argv || !argv[0]) {
2223 pi->cmdtext = xzalloc(1);
2228 do len += strlen(*argv) + 1; while (*++argv);
2229 pi->cmdtext = p = xmalloc(len);
2230 argv = pi->cmds[0].argv;
2232 len = strlen(*argv);
2233 memcpy(p, *argv, len);
2241 static void insert_bg_job(struct pipe *pi)
2243 struct pipe *thejob;
2246 /* Linear search for the ID of the job to use */
2248 for (thejob = G.job_list; thejob; thejob = thejob->next)
2249 if (thejob->jobid >= pi->jobid)
2250 pi->jobid = thejob->jobid + 1;
2252 /* Add thejob to the list of running jobs */
2254 thejob = G.job_list = xmalloc(sizeof(*thejob));
2256 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2258 thejob->next = xmalloc(sizeof(*thejob));
2259 thejob = thejob->next;
2262 /* Physically copy the struct job */
2263 memcpy(thejob, pi, sizeof(struct pipe));
2264 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2265 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2266 for (i = 0; i < pi->num_cmds; i++) {
2267 // TODO: do we really need to have so many fields which are just dead weight
2268 // at execution stage?
2269 thejob->cmds[i].pid = pi->cmds[i].pid;
2270 /* all other fields are not used and stay zero */
2272 thejob->next = NULL;
2273 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2275 /* We don't wait for background thejobs to return -- append it
2276 to the list of backgrounded thejobs and leave it alone */
2277 if (G.interactive_fd)
2278 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2279 G.last_bg_pid = thejob->cmds[0].pid;
2280 G.last_jobid = thejob->jobid;
2283 static void remove_bg_job(struct pipe *pi)
2285 struct pipe *prev_pipe;
2287 if (pi == G.job_list) {
2288 G.job_list = pi->next;
2290 prev_pipe = G.job_list;
2291 while (prev_pipe->next != pi)
2292 prev_pipe = prev_pipe->next;
2293 prev_pipe->next = pi->next;
2296 G.last_jobid = G.job_list->jobid;
2301 /* Remove a backgrounded job */
2302 static void delete_finished_bg_job(struct pipe *pi)
2305 pi->stopped_cmds = 0;
2311 /* Check to see if any processes have exited -- if they
2312 * have, figure out why and see if a job has completed */
2313 static int checkjobs(struct pipe* fg_pipe)
2323 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2325 attributes = WUNTRACED;
2326 if (fg_pipe == NULL)
2327 attributes |= WNOHANG;
2329 /* Do we do this right?
2330 * bash-3.00# sleep 20 | false
2332 * [3]+ Stopped sleep 20 | false
2333 * bash-3.00# echo $?
2334 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2337 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2338 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2339 // + killall -STOP cat
2342 // TODO: safe_waitpid?
2343 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
2345 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
2347 if (WIFSTOPPED(status))
2348 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2349 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2350 if (WIFSIGNALED(status))
2351 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2352 childpid, WTERMSIG(status), WEXITSTATUS(status));
2353 if (WIFEXITED(status))
2354 debug_printf_jobs("pid %d exited, exitcode %d\n",
2355 childpid, WEXITSTATUS(status));
2357 /* Were we asked to wait for fg pipe? */
2359 for (i = 0; i < fg_pipe->num_cmds; i++) {
2360 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2361 if (fg_pipe->cmds[i].pid != childpid)
2363 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2365 fg_pipe->cmds[i].pid = 0;
2366 fg_pipe->alive_cmds--;
2367 if (i == fg_pipe->num_cmds - 1) {
2368 /* last process gives overall exitstatus */
2369 rcode = WEXITSTATUS(status);
2370 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2373 fg_pipe->cmds[i].is_stopped = 1;
2374 fg_pipe->stopped_cmds++;
2376 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2377 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2378 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2379 /* All processes in fg pipe have exited/stopped */
2381 if (fg_pipe->alive_cmds)
2382 insert_bg_job(fg_pipe);
2386 /* There are still running processes in the fg pipe */
2387 goto wait_more; /* do waitpid again */
2389 /* it wasnt fg_pipe, look for process in bg pipes */
2393 /* We asked to wait for bg or orphaned children */
2394 /* No need to remember exitcode in this case */
2395 for (pi = G.job_list; pi; pi = pi->next) {
2396 for (i = 0; i < pi->num_cmds; i++) {
2397 if (pi->cmds[i].pid == childpid)
2398 goto found_pi_and_prognum;
2401 /* Happens when shell is used as init process (init=/bin/sh) */
2402 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2403 continue; /* do waitpid again */
2405 found_pi_and_prognum:
2408 pi->cmds[i].pid = 0;
2410 if (!pi->alive_cmds) {
2411 if (G.interactive_fd)
2412 printf(JOB_STATUS_FORMAT, pi->jobid,
2413 "Done", pi->cmdtext);
2414 delete_finished_bg_job(pi);
2418 pi->cmds[i].is_stopped = 1;
2422 } /* while (waitpid succeeds)... */
2424 /* wait found no children or failed */
2426 if (childpid && errno != ECHILD)
2427 bb_perror_msg("waitpid");
2432 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2435 int rcode = checkjobs(fg_pipe);
2436 /* Job finished, move the shell to the foreground */
2437 p = getpgid(0); /* pgid of our process */
2438 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2439 tcsetpgrp(G.interactive_fd, p);
2444 /* run_pipe() starts all the jobs, but doesn't wait for anything
2445 * to finish. See checkjobs().
2447 * return code is normally -1, when the caller has to wait for children
2448 * to finish to determine the exit status of the pipe. If the pipe
2449 * is a simple builtin command, however, the action is done by the
2450 * time run_pipe returns, and the exit code is provided as the
2453 * The input of the pipe is always stdin, the output is always
2454 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2455 * because it tries to avoid running the command substitution in
2456 * subshell, when that is in fact necessary. The subshell process
2457 * now has its stdout directed to the input of the appropriate pipe,
2458 * so this routine is noticeably simpler.
2460 * Returns -1 only if started some children. IOW: we have to
2461 * mask out retvals of builtins etc with 0xff!
2463 static int run_pipe(struct pipe *pi)
2467 int pipefds[2]; /* pipefds[0] is for reading */
2468 struct command *command;
2469 char **argv_expanded;
2471 const struct built_in_command *x;
2473 /* it is not always needed, but we aim to smaller code */
2474 int squirrel[] = { -1, -1, -1 };
2476 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2478 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2484 pi->stopped_cmds = 0;
2486 /* Check if this is a simple builtin (not part of a pipe).
2487 * Builtins within pipes have to fork anyway, and are handled in
2488 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2490 command = &(pi->cmds[0]);
2492 #if ENABLE_HUSH_FUNCTIONS
2493 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2494 /* We "execute" function definition */
2495 bb_error_msg("here we ought to remember function definition, and go on");
2496 return EXIT_SUCCESS;
2500 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2501 debug_printf("non-subshell grouping\n");
2502 setup_redirects(command, squirrel);
2503 debug_printf_exec(": run_list\n");
2504 rcode = run_list(command->group) & 0xff;
2505 restore_redirects(squirrel);
2506 debug_printf_exec("run_pipe return %d\n", rcode);
2507 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2511 argv = command->argv;
2512 argv_expanded = NULL;
2514 if (single_and_fg && argv != NULL) {
2515 char **new_env = NULL;
2516 char **old_env = NULL;
2518 i = command->assignment_cnt;
2519 if (i != 0 && argv[i] == NULL) {
2520 /* assignments, but no command: set local environment */
2521 for (i = 0; argv[i] != NULL; i++) {
2522 debug_printf("local environment set: %s\n", argv[i]);
2523 p = expand_string_to_string(argv[i]);
2524 set_local_var(p, 0);
2526 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2529 /* Expand the rest into (possibly) many strings each */
2530 argv_expanded = expand_strvec_to_strvec(argv + i);
2532 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2533 if (strcmp(argv_expanded[0], x->cmd) != 0)
2535 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2536 debug_printf("exec with redirects only\n");
2537 setup_redirects(command, NULL);
2538 rcode = EXIT_SUCCESS;
2539 goto clean_up_and_ret1;
2541 debug_printf("builtin inline %s\n", argv_expanded[0]);
2542 /* XXX setup_redirects acts on file descriptors, not FILEs.
2543 * This is perfect for work that comes after exec().
2544 * Is it really safe for inline use? Experimentally,
2545 * things seem to work with glibc. */
2546 setup_redirects(command, squirrel);
2547 new_env = expand_assignments(argv, command->assignment_cnt);
2548 old_env = putenv_all_and_save_old(new_env);
2549 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2550 rcode = x->function(argv_expanded) & 0xff;
2551 #if ENABLE_FEATURE_SH_STANDALONE
2554 restore_redirects(squirrel);
2555 free_strings_and_unsetenv(new_env, 1);
2556 putenv_all(old_env);
2557 free(old_env); /* not free_strings()! */
2559 free(argv_expanded);
2560 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2561 debug_printf_exec("run_pipe return %d\n", rcode);
2564 #if ENABLE_FEATURE_SH_STANDALONE
2565 i = find_applet_by_name(argv_expanded[0]);
2566 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2567 setup_redirects(command, squirrel);
2568 save_nofork_data(&G.nofork_save);
2569 new_env = expand_assignments(argv, command->assignment_cnt);
2570 old_env = putenv_all_and_save_old(new_env);
2571 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2572 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2573 goto clean_up_and_ret;
2578 /* NB: argv_expanded may already be created, and that
2579 * might include `cmd` runs! Do not rerun it! We *must*
2580 * use argv_expanded if it's non-NULL */
2582 /* Going to fork a child per each pipe member */
2586 for (i = 0; i < pi->num_cmds; i++) {
2588 volatile nommu_save_t nommu_save;
2589 nommu_save.new_env = NULL;
2590 nommu_save.old_env = NULL;
2591 nommu_save.argv = NULL;
2593 command = &(pi->cmds[i]);
2594 if (command->argv) {
2595 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2597 debug_printf_exec(": pipe member with no argv\n");
2599 /* pipes are inserted between pairs of commands */
2602 if ((i + 1) < pi->num_cmds)
2605 command->pid = BB_MMU ? fork() : vfork();
2606 if (!command->pid) { /* child */
2608 die_sleep = 0; /* let nofork's xfuncs die */
2610 /* Every child adds itself to new process group
2611 * with pgid == pid_of_first_child_in_pipe */
2612 if (G.run_list_level == 1 && G.interactive_fd) {
2615 if (pgrp < 0) /* true for 1st process only */
2617 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2618 /* We do it in *every* child, not just first,
2620 tcsetpgrp(G.interactive_fd, pgrp);
2624 xmove_fd(nextin, 0);
2625 xmove_fd(pipefds[1], 1); /* write end */
2627 close(pipefds[0]); /* read end */
2628 /* Like bash, explicit redirects override pipes,
2629 * and the pipe fd is available for dup'ing. */
2630 setup_redirects(command, NULL);
2632 /* Restore default handlers just prior to exec */
2633 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2635 /* Stores to nommu_save list of env vars putenv'ed
2636 * (NOMMU, on MMU we don't need that) */
2637 /* cast away volatility... */
2638 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2639 /* pseudo_exec() does not return */
2643 /* Clean up after vforked child */
2644 free(nommu_save.argv);
2645 free_strings_and_unsetenv(nommu_save.new_env, 1);
2646 putenv_all(nommu_save.old_env);
2648 free(argv_expanded);
2649 argv_expanded = NULL;
2650 if (command->pid < 0) { /* [v]fork failed */
2651 /* Clearly indicate, was it fork or vfork */
2652 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2656 /* Second and next children need to know pid of first one */
2658 pi->pgrp = command->pid;
2664 if ((i + 1) < pi->num_cmds)
2665 close(pipefds[1]); /* write end */
2666 /* Pass read (output) pipe end to next iteration */
2667 nextin = pipefds[0];
2670 if (!pi->alive_cmds) {
2671 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2675 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2679 #ifndef debug_print_tree
2680 static void debug_print_tree(struct pipe *pi, int lvl)
2682 static const char *const PIPE[] = {
2688 static const char *RES[] = {
2689 [RES_NONE ] = "NONE" ,
2692 [RES_THEN ] = "THEN" ,
2693 [RES_ELIF ] = "ELIF" ,
2694 [RES_ELSE ] = "ELSE" ,
2697 #if ENABLE_HUSH_LOOPS
2698 [RES_FOR ] = "FOR" ,
2699 [RES_WHILE] = "WHILE",
2700 [RES_UNTIL] = "UNTIL",
2702 [RES_DONE ] = "DONE" ,
2704 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2707 #if ENABLE_HUSH_CASE
2708 [RES_CASE ] = "CASE" ,
2709 [RES_MATCH] = "MATCH",
2710 [RES_CASEI] = "CASEI",
2711 [RES_ESAC ] = "ESAC" ,
2713 [RES_XXXX ] = "XXXX" ,
2714 [RES_SNTX ] = "SNTX" ,
2716 static const char *const GRPTYPE[] = {
2719 #if ENABLE_HUSH_FUNCTIONS
2728 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2729 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2731 while (prn < pi->num_cmds) {
2732 struct command *command = &pi->cmds[prn];
2733 char **argv = command->argv;
2735 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2736 if (command->group) {
2737 fprintf(stderr, " group %s: (argv=%p)\n",
2738 GRPTYPE[command->grp_type],
2740 debug_print_tree(command->group, lvl+1);
2744 if (argv) while (*argv) {
2745 fprintf(stderr, " '%s'", *argv);
2748 fprintf(stderr, "\n");
2757 /* NB: called by pseudo_exec, and therefore must not modify any
2758 * global data until exec/_exit (we can be a child after vfork!) */
2759 static int run_list(struct pipe *pi)
2761 #if ENABLE_HUSH_CASE
2762 char *case_word = NULL;
2764 #if ENABLE_HUSH_LOOPS
2765 struct pipe *loop_top = NULL;
2766 char *for_varname = NULL;
2767 char **for_lcur = NULL;
2768 char **for_list = NULL;
2770 smallint flag_skip = 1;
2771 smalluint rcode = 0; /* probably just for compiler */
2772 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2773 smalluint cond_code = 0;
2775 enum { cond_code = 0, };
2777 /*enum reserved_style*/ smallint rword = RES_NONE;
2778 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2780 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2782 #if ENABLE_HUSH_LOOPS
2783 /* Check syntax for "for" */
2784 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2785 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2787 /* current word is FOR or IN (BOLD in comments below) */
2788 if (cpipe->next == NULL) {
2789 syntax("malformed for");
2790 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2793 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2794 if (cpipe->next->res_word == RES_DO)
2796 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2797 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2798 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2800 syntax("malformed for");
2801 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2807 /* Past this point, all code paths should jump to ret: label
2808 * in order to return, no direct "return" statements please.
2809 * This helps to ensure that no memory is leaked. */
2811 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2814 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2815 * We are saving state before entering outermost list ("while...done")
2816 * so that ctrl-Z will correctly background _entire_ outermost list,
2817 * not just a part of it (like "sleep 1 | exit 2") */
2818 if (++G.run_list_level == 1 && G.interactive_fd) {
2819 if (sigsetjmp(G.toplevel_jb, 1)) {
2820 /* ctrl-Z forked and we are parent; or ctrl-C.
2821 * Sighandler has longjmped us here */
2822 signal(SIGINT, SIG_IGN);
2823 signal(SIGTSTP, SIG_IGN);
2824 /* Restore level (we can be coming from deep inside
2826 G.run_list_level = 1;
2827 #if ENABLE_FEATURE_SH_STANDALONE
2828 if (G.nofork_save.saved) { /* if save area is valid */
2829 debug_printf_jobs("exiting nofork early\n");
2830 restore_nofork_data(&G.nofork_save);
2833 //// if (G.ctrl_z_flag) {
2834 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2835 //// * Remember this child as background job */
2836 //// insert_bg_job(pi);
2838 /* ctrl-C. We just stop doing whatever we were doing */
2841 USE_HUSH_LOOPS(loop_top = NULL;)
2842 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2846 //// /* ctrl-Z handler will store pid etc in pi */
2847 //// G.toplevel_list = pi;
2848 //// G.ctrl_z_flag = 0;
2849 ////#if ENABLE_FEATURE_SH_STANDALONE
2850 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2852 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2853 //// signal(SIGINT, handler_ctrl_c);
2857 /* Go through list of pipes, (maybe) executing them. */
2858 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2862 IF_HAS_KEYWORDS(rword = pi->res_word;)
2863 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2864 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2865 rword, cond_code, skip_more_for_this_rword);
2866 #if ENABLE_HUSH_LOOPS
2867 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2868 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2870 /* start of a loop: remember where loop starts */
2875 if (rword == skip_more_for_this_rword && flag_skip) {
2876 if (pi->followup == PIPE_SEQ)
2878 /* it is "<false> && CMD" or "<true> || CMD"
2879 * and we should not execute CMD */
2883 skip_more_for_this_rword = RES_XXXX;
2886 if (rword == RES_THEN) {
2887 /* "if <false> THEN cmd": skip cmd */
2891 if (rword == RES_ELSE || rword == RES_ELIF) {
2892 /* "if <true> then ... ELSE/ELIF cmd":
2893 * skip cmd and all following ones */
2898 #if ENABLE_HUSH_LOOPS
2899 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
2901 /* first loop through for */
2903 static const char encoded_dollar_at[] ALIGN1 = {
2904 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
2905 }; /* encoded representation of "$@" */
2906 static const char *const encoded_dollar_at_argv[] = {
2907 encoded_dollar_at, NULL
2908 }; /* argv list with one element: "$@" */
2911 vals = (char**)encoded_dollar_at_argv;
2912 if (pi->next->res_word == RES_IN) {
2913 /* if no variable values after "in" we skip "for" */
2914 if (!pi->next->cmds[0].argv)
2916 vals = pi->next->cmds[0].argv;
2917 } /* else: "for var; do..." -> assume "$@" list */
2918 /* create list of variable values */
2919 debug_print_strings("for_list made from", vals);
2920 for_list = expand_strvec_to_strvec(vals);
2921 for_lcur = for_list;
2922 debug_print_strings("for_list", for_list);
2923 for_varname = pi->cmds[0].argv[0];
2924 pi->cmds[0].argv[0] = NULL;
2926 free(pi->cmds[0].argv[0]);
2928 /* "for" loop is over, clean up */
2932 pi->cmds[0].argv[0] = for_varname;
2935 /* insert next value from for_lcur */
2936 //TODO: does it need escaping?
2937 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2938 pi->cmds[0].assignment_cnt = 1;
2940 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
2942 if (rword == RES_DONE) {
2943 continue; /* "done" has no cmds too */
2946 #if ENABLE_HUSH_CASE
2947 if (rword == RES_CASE) {
2948 case_word = expand_strvec_to_string(pi->cmds->argv);
2951 if (rword == RES_MATCH) {
2954 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
2956 /* all prev words didn't match, does this one match? */
2957 argv = pi->cmds->argv;
2959 char *pattern = expand_string_to_string(*argv);
2960 /* TODO: which FNM_xxx flags to use? */
2961 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
2963 if (cond_code == 0) { /* match! we will execute this branch */
2964 free(case_word); /* make future "word)" stop */
2972 if (rword == RES_CASEI) { /* inside of a case branch */
2974 continue; /* not matched yet, skip this pipe */
2977 /* Just pressing <enter> in shell should check for jobs.
2978 * OTOH, in non-interactive shell this is useless
2979 * and only leads to extra job checks */
2980 if (pi->num_cmds == 0) {
2981 if (G.interactive_fd)
2982 goto check_jobs_and_continue;
2986 /* After analyzing all keywords and conditions, we decided
2987 * to execute this pipe. NB: have to do checkjobs(NULL)
2988 * after run_pipe() to collect any background children,
2989 * even if list execution is to be stopped. */
2990 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
2993 #if ENABLE_HUSH_LOOPS
2994 G.flag_break_continue = 0;
2996 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
2998 /* we only ran a builtin: rcode is already known
2999 * and we don't need to wait for anything. */
3000 check_and_run_traps();
3001 #if ENABLE_HUSH_LOOPS
3002 /* was it "break" or "continue"? */
3003 if (G.flag_break_continue) {
3004 smallint fbc = G.flag_break_continue;
3005 /* we might fall into outer *loop*,
3006 * don't want to break it too */
3008 G.depth_break_continue--;
3009 if (G.depth_break_continue == 0)
3010 G.flag_break_continue = 0;
3011 /* else: e.g. "continue 2" should *break* once, *then* continue */
3012 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3013 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3014 goto check_jobs_and_break;
3015 /* "continue": simulate end of loop */
3020 } else if (pi->followup == PIPE_BG) {
3021 /* what does bash do with attempts to background builtins? */
3022 /* even bash 3.2 doesn't do that well with nested bg:
3023 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3024 * I'm NOT treating inner &'s as jobs */
3025 check_and_run_traps();
3027 if (G.run_list_level == 1)
3030 rcode = 0; /* EXIT_SUCCESS */
3033 if (G.run_list_level == 1 && G.interactive_fd) {
3034 /* waits for completion, then fg's main shell */
3035 rcode = checkjobs_and_fg_shell(pi);
3036 check_and_run_traps();
3037 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3040 { /* this one just waits for completion */
3041 rcode = checkjobs(pi);
3042 check_and_run_traps();
3043 debug_printf_exec(": checkjobs returned %d\n", rcode);
3047 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3048 G.last_return_code = rcode;
3050 /* Analyze how result affects subsequent commands */
3052 if (rword == RES_IF || rword == RES_ELIF)
3055 #if ENABLE_HUSH_LOOPS
3056 if (rword == RES_WHILE) {
3058 rcode = 0; /* "while false; do...done" - exitcode 0 */
3059 goto check_jobs_and_break;
3062 if (rword == RES_UNTIL) {
3064 check_jobs_and_break:
3070 if ((rcode == 0 && pi->followup == PIPE_OR)
3071 || (rcode != 0 && pi->followup == PIPE_AND)
3073 skip_more_for_this_rword = rword;
3076 check_jobs_and_continue:
3081 //// if (G.ctrl_z_flag) {
3082 //// /* ctrl-Z forked somewhere in the past, we are the child,
3083 //// * and now we completed running the list. Exit. */
3089 //// if (!G.run_list_level && G.interactive_fd) {
3090 //// signal(SIGTSTP, SIG_IGN);
3091 //// signal(SIGINT, SIG_IGN);
3094 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3095 #if ENABLE_HUSH_LOOPS
3100 #if ENABLE_HUSH_CASE
3106 /* Select which version we will use */
3107 static int run_and_free_list(struct pipe *pi)
3110 debug_printf_exec("run_and_free_list entered\n");
3112 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3113 rcode = run_list(pi);
3115 /* free_pipe_list has the side effect of clearing memory.
3116 * In the long run that function can be merged with run_list,
3117 * but doing that now would hobble the debugging effort. */
3118 free_pipe_list(pi, /* indent: */ 0);
3119 debug_printf_exec("run_and_free_list return %d\n", rcode);
3124 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3125 * as in "2>&1", that represents duplicating a file descriptor.
3126 * Return either -2 (syntax error), -1 (no &), or the number found.
3128 static int redirect_dup_num(struct in_str *input)
3130 int ch, d = 0, ok = 0;
3132 if (ch != '&') return -1;
3134 i_getch(input); /* get the & */
3138 return -3; /* "-" represents "close me" */
3140 while (isdigit(ch)) {
3141 d = d*10 + (ch-'0');
3148 bb_error_msg("ambiguous redirect");
3152 /* The src parameter allows us to peek forward to a possible &n syntax
3153 * for file descriptor duplication, e.g., "2>&1".
3154 * Return code is 0 normally, 1 if a syntax error is detected in src.
3155 * Resource errors (in xmalloc) cause the process to exit */
3156 static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
3157 struct in_str *input)
3159 struct command *command = ctx->command;
3160 struct redir_struct *redir = command->redirects;
3161 struct redir_struct *last_redir = NULL;
3163 /* Create a new redir_struct and drop it onto the end of the linked list */
3166 redir = redir->next;
3168 redir = xzalloc(sizeof(struct redir_struct));
3169 /* redir->next = NULL; */
3170 /* redir->rd_filename = NULL; */
3172 last_redir->next = redir;
3174 command->redirects = redir;
3177 redir->rd_type = style;
3178 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3180 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3182 /* Check for a '2>&1' type redirect */
3183 redir->dup = redirect_dup_num(input);
3184 if (redir->dup == -2)
3185 return 1; /* syntax error */
3186 if (redir->dup != -1) {
3187 /* Erik had a check here that the file descriptor in question
3188 * is legit; I postpone that to "run time"
3189 * A "-" representation of "close me" shows up as a -3 here */
3190 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3192 /* We do _not_ try to open the file that src points to,
3193 * since we need to return and let src be expanded first.
3194 * Set ctx->pending_redirect, so we know what to do at the
3195 * end of the next parsed word. */
3196 ctx->pending_redirect = redir;
3202 static struct pipe *new_pipe(void)
3205 pi = xzalloc(sizeof(struct pipe));
3206 /*pi->followup = 0; - deliberately invalid value */
3207 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3211 /* Command (member of a pipe) is complete. The only possible error here
3212 * is out of memory, in which case xmalloc exits. */
3213 static int done_command(struct parse_context *ctx)
3215 /* The command is really already in the pipe structure, so
3216 * advance the pipe counter and make a new, null command. */
3217 struct pipe *pi = ctx->pipe;
3218 struct command *command = ctx->command;
3221 if (command->group == NULL
3222 && command->argv == NULL
3223 && command->redirects == NULL
3225 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3226 return pi->num_cmds;
3229 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3231 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3234 /* Only real trickiness here is that the uncommitted
3235 * command structure is not counted in pi->num_cmds. */
3236 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3237 command = &pi->cmds[pi->num_cmds];
3238 memset(command, 0, sizeof(*command));
3240 ctx->command = command;
3241 /* but ctx->pipe and ctx->list_head remain unchanged */
3243 return pi->num_cmds; /* used only for 0/nonzero check */
3246 static void done_pipe(struct parse_context *ctx, pipe_style type)
3250 debug_printf_parse("done_pipe entered, followup %d\n", type);
3251 /* Close previous command */
3252 not_null = done_command(ctx);
3253 ctx->pipe->followup = type;
3254 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3255 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3256 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3258 /* Without this check, even just <enter> on command line generates
3259 * tree of three NOPs (!). Which is harmless but annoying.
3260 * IOW: it is safe to do it unconditionally.
3261 * RES_NONE case is for "for a in; do ..." (empty IN set)
3262 * to work, possibly other cases too. */
3263 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3265 debug_printf_parse("done_pipe: adding new pipe: "
3266 "not_null:%d ctx->ctx_res_w:%d\n",
3267 not_null, ctx->ctx_res_w);
3269 ctx->pipe->next = new_p;
3271 ctx->command = NULL; /* needed! */
3272 /* RES_THEN, RES_DO etc are "sticky" -
3273 * they remain set for commands inside if/while.
3274 * This is used to control execution.
3275 * RES_FOR and RES_IN are NOT sticky (needed to support
3276 * cases where variable or value happens to match a keyword):
3278 #if ENABLE_HUSH_LOOPS
3279 if (ctx->ctx_res_w == RES_FOR
3280 || ctx->ctx_res_w == RES_IN)
3281 ctx->ctx_res_w = RES_NONE;
3283 #if ENABLE_HUSH_CASE
3284 if (ctx->ctx_res_w == RES_MATCH)
3285 ctx->ctx_res_w = RES_CASEI;
3287 /* Create the memory for command, roughly:
3288 * ctx->pipe->cmds = new struct command;
3289 * ctx->command = &ctx->pipe->cmds[0];
3293 debug_printf_parse("done_pipe return\n");
3296 static void initialize_context(struct parse_context *ctx)
3298 memset(ctx, 0, sizeof(*ctx));
3299 ctx->pipe = ctx->list_head = new_pipe();
3300 /* Create the memory for command, roughly:
3301 * ctx->pipe->cmds = new struct command;
3302 * ctx->command = &ctx->pipe->cmds[0];
3308 /* If a reserved word is found and processed, parse context is modified
3309 * and 1 is returned.
3310 * Handles if, then, elif, else, fi, for, while, until, do, done.
3311 * case, function, and select are obnoxious, save those for later.
3314 struct reserved_combo {
3317 unsigned char assignment_flag;
3321 FLAG_END = (1 << RES_NONE ),
3323 FLAG_IF = (1 << RES_IF ),
3324 FLAG_THEN = (1 << RES_THEN ),
3325 FLAG_ELIF = (1 << RES_ELIF ),
3326 FLAG_ELSE = (1 << RES_ELSE ),
3327 FLAG_FI = (1 << RES_FI ),
3329 #if ENABLE_HUSH_LOOPS
3330 FLAG_FOR = (1 << RES_FOR ),
3331 FLAG_WHILE = (1 << RES_WHILE),
3332 FLAG_UNTIL = (1 << RES_UNTIL),
3333 FLAG_DO = (1 << RES_DO ),
3334 FLAG_DONE = (1 << RES_DONE ),
3335 FLAG_IN = (1 << RES_IN ),
3337 #if ENABLE_HUSH_CASE
3338 FLAG_MATCH = (1 << RES_MATCH),
3339 FLAG_ESAC = (1 << RES_ESAC ),
3341 FLAG_START = (1 << RES_XXXX ),
3344 static const struct reserved_combo* match_reserved_word(o_string *word)
3346 /* Mostly a list of accepted follow-up reserved words.
3347 * FLAG_END means we are done with the sequence, and are ready
3348 * to turn the compound list into a command.
3349 * FLAG_START means the word must start a new compound list.
3351 static const struct reserved_combo reserved_list[] = {
3353 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3354 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3355 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3356 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3357 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3358 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3360 #if ENABLE_HUSH_LOOPS
3361 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3362 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3363 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3364 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3365 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3366 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3368 #if ENABLE_HUSH_CASE
3369 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3370 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3373 const struct reserved_combo *r;
3375 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3376 if (strcmp(word->data, r->literal) == 0)
3381 static int reserved_word(o_string *word, struct parse_context *ctx)
3383 #if ENABLE_HUSH_CASE
3384 static const struct reserved_combo reserved_match = {
3385 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3388 const struct reserved_combo *r;
3390 r = match_reserved_word(word);
3394 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3395 #if ENABLE_HUSH_CASE
3396 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3397 /* "case word IN ..." - IN part starts first match part */
3398 r = &reserved_match;
3401 if (r->flag == 0) { /* '!' */
3402 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3404 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3406 ctx->ctx_inverted = 1;
3409 if (r->flag & FLAG_START) {
3410 struct parse_context *new;
3411 debug_printf("push stack\n");
3412 new = xmalloc(sizeof(*new));
3413 *new = *ctx; /* physical copy */
3414 initialize_context(ctx);
3416 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3418 ctx->ctx_res_w = RES_SNTX;
3421 ctx->ctx_res_w = r->res;
3422 ctx->old_flag = r->flag;
3423 if (ctx->old_flag & FLAG_END) {
3424 struct parse_context *old;
3425 debug_printf("pop stack\n");
3426 done_pipe(ctx, PIPE_SEQ);
3428 old->command->group = ctx->list_head;
3429 old->command->grp_type = GRP_NORMAL;
3430 *ctx = *old; /* physical copy */
3433 word->o_assignment = r->assignment_flag;
3438 //TODO: many, many callers don't check error from done_word()
3440 /* Word is complete, look at it and update parsing context.
3441 * Normal return is 0. Syntax errors return 1. */
3442 static int done_word(o_string *word, struct parse_context *ctx)
3444 struct command *command = ctx->command;
3446 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3447 if (word->length == 0 && word->nonnull == 0) {
3448 debug_printf_parse("done_word return 0: true null, ignored\n");
3451 /* If this word wasn't an assignment, next ones definitely
3452 * can't be assignments. Even if they look like ones. */
3453 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3454 && word->o_assignment != WORD_IS_KEYWORD
3456 word->o_assignment = NOT_ASSIGNMENT;
3458 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3459 command->assignment_cnt++;
3460 word->o_assignment = MAYBE_ASSIGNMENT;
3463 if (ctx->pending_redirect) {
3464 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3465 * only if run as "bash", not "sh" */
3466 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3467 word->o_assignment = NOT_ASSIGNMENT;
3468 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3470 /* "{ echo foo; } echo bar" - bad */
3471 /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
3472 if (command->group) {
3474 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3478 #if ENABLE_HUSH_CASE
3479 if (ctx->ctx_dsemicolon
3480 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3482 /* already done when ctx_dsemicolon was set to 1: */
3483 /* ctx->ctx_res_w = RES_MATCH; */
3484 ctx->ctx_dsemicolon = 0;
3488 if (!command->argv /* if it's the first word... */
3489 #if ENABLE_HUSH_LOOPS
3490 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3491 && ctx->ctx_res_w != RES_IN
3494 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3495 if (reserved_word(word, ctx)) {
3497 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3498 return (ctx->ctx_res_w == RES_SNTX);
3502 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3503 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3504 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3505 /* (otherwise it's known to be not empty and is already safe) */
3507 /* exclude "$@" - it can expand to no word despite "" */
3508 char *p = word->data;
3509 while (p[0] == SPECIAL_VAR_SYMBOL
3510 && (p[1] & 0x7f) == '@'
3511 && p[2] == SPECIAL_VAR_SYMBOL
3515 if (p == word->data || p[0] != '\0') {
3516 /* saw no "$@", or not only "$@" but some
3517 * real text is there too */
3518 /* insert "empty variable" reference, this makes
3519 * e.g. "", $empty"" etc to not disappear */
3520 o_addchr(word, SPECIAL_VAR_SYMBOL);
3521 o_addchr(word, SPECIAL_VAR_SYMBOL);
3524 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3525 debug_print_strings("word appended to argv", command->argv);
3529 ctx->pending_redirect = NULL;
3531 #if ENABLE_HUSH_LOOPS
3532 /* Force FOR to have just one word (variable name) */
3533 /* NB: basically, this makes hush see "for v in ..." syntax as if
3534 * as it is "for v; in ...". FOR and IN become two pipe structs
3536 if (ctx->ctx_res_w == RES_FOR) {
3537 //TODO: check that command->argv[0] is a valid variable name!
3538 done_pipe(ctx, PIPE_SEQ);
3541 #if ENABLE_HUSH_CASE
3542 /* Force CASE to have just one word */
3543 if (ctx->ctx_res_w == RES_CASE) {
3544 done_pipe(ctx, PIPE_SEQ);
3547 debug_printf_parse("done_word return 0\n");
3551 /* If a redirect is immediately preceded by a number, that number is
3552 * supposed to tell which file descriptor to redirect. This routine
3553 * looks for such preceding numbers. In an ideal world this routine
3554 * needs to handle all the following classes of redirects...
3555 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3556 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3557 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3558 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3559 * A -1 output from this program means no valid number was found, so the
3560 * caller should use the appropriate default for this redirection.
3562 static int redirect_opt_num(o_string *o)
3568 for (num = 0; num < o->length; num++) {
3569 if (!isdigit(o->data[num])) {
3573 num = atoi(o->data);
3578 static int parse_stream(o_string *dest, struct parse_context *ctx,
3579 struct in_str *input0, const char *end_trigger);
3581 #if ENABLE_HUSH_TICK
3582 static FILE *generate_stream_from_list(struct pipe *head)
3585 int pid, channel[2];
3588 /* *** NOMMU WARNING *** */
3589 /* By using vfork here, we suspend parent till child exits or execs.
3590 * If child will not do it before it fills the pipe, it can block forever
3591 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3593 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3594 * huge=`cat TESTFILE` # will block here forever
3597 pid = BB_MMU ? fork() : vfork();
3599 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3600 if (pid == 0) { /* child */
3601 if (ENABLE_HUSH_JOB)
3602 die_sleep = 0; /* let nofork's xfuncs die */
3603 close(channel[0]); /* NB: close _first_, then move fd! */
3604 xmove_fd(channel[1], 1);
3605 /* Prevent it from trying to handle ctrl-z etc */
3607 G.run_list_level = 1;
3609 /* Process substitution is not considered to be usual
3610 * 'command execution'.
3611 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3613 set_jobctrl_signals_to_IGN();
3615 /* Note: freeing 'head' here would break NOMMU. */
3616 _exit(run_list(head));
3619 pf = fdopen(channel[0], "r");
3621 /* 'head' is freed by the caller */
3624 /* Return code is exit status of the process that is run. */
3625 static int process_command_subs(o_string *dest,
3626 struct in_str *input,
3627 const char *subst_end)
3629 int retcode, ch, eol_cnt;
3630 o_string result = NULL_O_STRING;
3631 struct parse_context inner;
3633 struct in_str pipe_str;
3635 initialize_context(&inner);
3637 /* Recursion to generate command */
3638 retcode = parse_stream(&result, &inner, input, subst_end);
3640 return retcode; /* syntax error or EOF */
3641 done_word(&result, &inner);
3642 done_pipe(&inner, PIPE_SEQ);
3645 p = generate_stream_from_list(inner.list_head);
3648 close_on_exec_on(fileno(p));
3649 setup_file_in_str(&pipe_str, p);
3651 /* Now send results of command back into original context */
3653 while ((ch = i_getch(&pipe_str)) != EOF) {
3659 o_addchr(dest, '\n');
3662 o_addQchr(dest, ch);
3665 debug_printf("done reading from pipe, pclose()ing\n");
3666 /* This is the step that wait()s for the child. Should be pretty
3667 * safe, since we just read an EOF from its stdout. We could try
3668 * to do better, by using wait(), and keeping track of background jobs
3669 * at the same time. That would be a lot of work, and contrary
3670 * to the KISS philosophy of this program. */
3671 retcode = fclose(p);
3672 free_pipe_list(inner.list_head, /* indent: */ 0);
3673 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3678 static int parse_group(o_string *dest, struct parse_context *ctx,
3679 struct in_str *input, int ch)
3681 /* dest contains characters seen prior to ( or {.
3682 * Typically it's empty, but for functions defs,
3683 * it contains function name (without '()'). */
3685 const char *endch = NULL;
3686 struct parse_context sub;
3687 struct command *command = ctx->command;
3689 debug_printf_parse("parse_group entered\n");
3690 #if ENABLE_HUSH_FUNCTIONS
3691 if (ch == 'F') { /* function definition? */
3692 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3693 //command->fname = dest->data;
3694 command->grp_type = GRP_FUNCTION;
3695 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3696 memset(dest, 0, sizeof(*dest));
3699 if (command->argv /* word [word](... */
3700 || dest->length /* word(... */
3701 || dest->nonnull /* ""(... */
3704 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3707 initialize_context(&sub);
3711 command->grp_type = GRP_SUBSHELL;
3713 rcode = parse_stream(dest, &sub, input, endch);
3715 done_word(dest, &sub); /* finish off the final word in the subcontext */
3716 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3717 command->group = sub.list_head;
3719 debug_printf_parse("parse_group return %d\n", rcode);
3721 /* command remains "open", available for possible redirects */
3724 #if ENABLE_HUSH_TICK
3725 /* Subroutines for copying $(...) and `...` things */
3726 static void add_till_backquote(o_string *dest, struct in_str *input);
3728 static void add_till_single_quote(o_string *dest, struct in_str *input)
3731 int ch = i_getch(input);
3739 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3740 static void add_till_double_quote(o_string *dest, struct in_str *input)
3743 int ch = i_getch(input);
3746 if (ch == '\\') { /* \x. Copy both chars. */
3748 ch = i_getch(input);
3754 add_till_backquote(dest, input);
3758 //if (ch == '$') ...
3761 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3763 * "Within the backquoted style of command substitution, backslash
3764 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3765 * The search for the matching backquote shall be satisfied by the first
3766 * backquote found without a preceding backslash; during this search,
3767 * if a non-escaped backquote is encountered within a shell comment,
3768 * a here-document, an embedded command substitution of the $(command)
3769 * form, or a quoted string, undefined results occur. A single-quoted
3770 * or double-quoted string that begins, but does not end, within the
3771 * "`...`" sequence produces undefined results."
3773 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3775 static void add_till_backquote(o_string *dest, struct in_str *input)
3778 int ch = i_getch(input);
3781 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3782 int ch2 = i_getch(input);
3783 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3792 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3793 * quoting and nested ()s.
3794 * "With the $(command) style of command substitution, all characters
3795 * following the open parenthesis to the matching closing parenthesis
3796 * constitute the command. Any valid shell script can be used for command,
3797 * except a script consisting solely of redirections which produces
3798 * unspecified results."
3800 * echo $(echo '(TEST)' BEST) (TEST) BEST
3801 * echo $(echo 'TEST)' BEST) TEST) BEST
3802 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3804 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3808 int ch = i_getch(input);
3818 add_till_single_quote(dest, input);
3823 add_till_double_quote(dest, input);
3827 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3828 ch = i_getch(input);
3836 #endif /* ENABLE_HUSH_TICK */
3838 /* Return code: 0 for OK, 1 for syntax error */
3839 static int handle_dollar(o_string *dest, struct in_str *input)
3842 int ch = i_peek(input); /* first character after the $ */
3843 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3845 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3849 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3851 debug_printf_parse(": '%c'\n", ch);
3852 o_addchr(dest, ch | quote_mask);
3855 if (!isalnum(ch) && ch != '_')
3859 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3860 } else if (isdigit(ch)) {
3863 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3864 debug_printf_parse(": '%c'\n", ch);
3865 o_addchr(dest, ch | quote_mask);
3866 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3867 } else switch (ch) {
3869 case '!': /* last bg pid */
3870 case '?': /* last exit code */
3871 case '#': /* number of args */
3872 case '*': /* args */
3873 case '@': /* args */
3874 goto make_one_char_var;
3876 bool first_char, all_digits;
3878 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3880 /* XXX maybe someone will try to escape the '}' */
3885 ch = i_getch(input);
3891 /* ${#var}: length of var contents */
3893 else if (isdigit(ch)) {
3899 if (expansion < 2 &&
3900 ((all_digits && !isdigit(ch)) ||
3901 (!all_digits && !isalnum(ch) && ch != '_')))
3903 /* handle parameter expansions
3904 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3909 case ':': /* null modifier */
3910 if (expansion == 0) {
3911 debug_printf_parse(": null modifier\n");
3917 #if 0 /* not implemented yet :( */
3918 case '#': /* remove prefix */
3919 case '%': /* remove suffix */
3920 if (expansion == 0) {
3921 debug_printf_parse(": remove suffix/prefix\n");
3928 case '-': /* default value */
3929 case '=': /* assign default */
3930 case '+': /* alternative */
3931 case '?': /* error indicate */
3932 debug_printf_parse(": parameter expansion\n");
3938 syntax("unterminated ${name}");
3939 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3945 debug_printf_parse(": '%c'\n", ch);
3946 o_addchr(dest, ch | quote_mask);
3950 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3953 #if ENABLE_HUSH_TICK
3955 //int pos = dest->length;
3957 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3958 o_addchr(dest, quote_mask | '`');
3959 add_till_closing_curly_brace(dest, input);
3960 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
3961 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3968 if (isalnum(ch)) { /* it's $_name or $_123 */
3974 /* still unhandled, but should be eventually */
3975 bb_error_msg("unhandled syntax: $%c", ch);
3979 o_addQchr(dest, '$');
3981 debug_printf_parse("handle_dollar return 0\n");
3985 /* Scan input, call done_word() whenever full IFS delimited word was seen.
3986 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
3987 * Return code is 0 if end_trigger char is met,
3988 * -1 on EOF (but if end_trigger == NULL then return 0),
3989 * 1 for syntax error */
3990 static int parse_stream(o_string *dest, struct parse_context *ctx,
3991 struct in_str *input, const char *end_trigger)
3995 redir_type redir_style;
3996 int shadow_quote = dest->o_quote;
3999 /* Only double-quote state is handled in the state variable dest->o_quote.
4000 * A single-quote triggers a bypass of the main loop until its mate is
4001 * found. When recursing, quote state is passed in via dest->o_quote. */
4003 debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
4008 ch = i_getch(input);
4012 next = i_peek(input);
4015 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
4016 ch, ch, m, dest->o_quote);
4017 if (m == CHAR_ORDINARY
4018 || (m != CHAR_SPECIAL && shadow_quote)
4021 syntax("unterminated \"");
4022 debug_printf_parse("parse_stream return 1: unterminated \"\n");
4025 o_addQchr(dest, ch);
4026 if ((dest->o_assignment == MAYBE_ASSIGNMENT
4027 || dest->o_assignment == WORD_IS_KEYWORD)
4029 && is_assignment(dest->data)
4031 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4035 if (m == CHAR_IFS) {
4036 if (done_word(dest, ctx)) {
4037 debug_printf_parse("parse_stream return 1: done_word!=0\n");
4042 /* If we aren't performing a substitution, treat
4043 * a newline as a command separator.
4044 * [why we don't handle it exactly like ';'? --vda] */
4045 if (end_trigger && ch == '\n') {
4046 #if ENABLE_HUSH_CASE
4047 /* "case ... in <newline> word) ..." -
4048 * newlines are ignored (but ';' wouldn't be) */
4049 if (dest->length == 0 // && argv[0] == NULL
4050 && ctx->ctx_res_w == RES_MATCH
4055 done_pipe(ctx, PIPE_SEQ);
4056 dest->o_assignment = MAYBE_ASSIGNMENT;
4060 if (!shadow_quote && strchr(end_trigger, ch)) {
4061 /* Special case: (...word) makes last word terminate,
4062 * as if ';' is seen */
4064 done_word(dest, ctx);
4066 done_pipe(ctx, PIPE_SEQ);
4067 dest->o_assignment = MAYBE_ASSIGNMENT;
4070 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
4072 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
4080 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
4081 /* ch is a special char and thus this word
4082 * cannot be an assignment: */
4083 dest->o_assignment = NOT_ASSIGNMENT;
4088 if (dest->length == 0 && !shadow_quote) {
4091 if (ch == EOF || ch == '\n')
4096 o_addQchr(dest, ch);
4102 debug_printf_parse("parse_stream return 1: \\<eof>\n");
4106 * "The backslash retains its special meaning [in "..."]
4107 * only when followed by one of the following characters:
4108 * $, `, ", \, or <newline>. A double quote may be quoted
4109 * within double quotes by preceding it with a backslash.
4110 * If enabled, history expansion will be performed unless
4111 * an ! appearing in double quotes is escaped using
4112 * a backslash. The backslash preceding the ! is not removed."
4114 if (shadow_quote) { //NOT SURE dest->o_quote) {
4115 if (strchr("$`\"\\", next) != NULL) {
4116 o_addqchr(dest, i_getch(input));
4118 o_addqchr(dest, '\\');
4121 o_addchr(dest, '\\');
4122 o_addchr(dest, i_getch(input));
4126 if (handle_dollar(dest, input) != 0) {
4127 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
4134 ch = i_getch(input);
4136 syntax("unterminated '");
4137 debug_printf_parse("parse_stream return 1: unterminated '\n");
4142 if (dest->o_assignment == NOT_ASSIGNMENT)
4143 o_addqchr(dest, ch);
4150 shadow_quote ^= 1; /* invert */
4151 if (dest->o_assignment == NOT_ASSIGNMENT)
4154 #if ENABLE_HUSH_TICK
4156 //int pos = dest->length;
4157 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4158 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
4159 add_till_backquote(dest, input);
4160 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4161 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4166 redir_fd = redirect_opt_num(dest);
4167 done_word(dest, ctx);
4168 redir_style = REDIRECT_OVERWRITE;
4170 redir_style = REDIRECT_APPEND;
4174 else if (next == '(') {
4175 syntax(">(process) not supported");
4176 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
4180 setup_redirect(ctx, redir_fd, redir_style, input);
4183 redir_fd = redirect_opt_num(dest);
4184 done_word(dest, ctx);
4185 redir_style = REDIRECT_INPUT;
4187 redir_style = REDIRECT_HEREIS;
4189 } else if (next == '>') {
4190 redir_style = REDIRECT_IO;
4194 else if (next == '(') {
4195 syntax("<(process) not supported");
4196 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
4200 setup_redirect(ctx, redir_fd, redir_style, input);
4203 #if ENABLE_HUSH_CASE
4206 done_word(dest, ctx);
4207 done_pipe(ctx, PIPE_SEQ);
4208 #if ENABLE_HUSH_CASE
4209 /* Eat multiple semicolons, detect
4210 * whether it means something special */
4216 if (ctx->ctx_res_w == RES_CASEI) {
4217 ctx->ctx_dsemicolon = 1;
4218 ctx->ctx_res_w = RES_MATCH;
4224 /* We just finished a cmd. New one may start
4225 * with an assignment */
4226 dest->o_assignment = MAYBE_ASSIGNMENT;
4229 done_word(dest, ctx);
4232 done_pipe(ctx, PIPE_AND);
4234 done_pipe(ctx, PIPE_BG);
4238 done_word(dest, ctx);
4239 #if ENABLE_HUSH_CASE
4240 if (ctx->ctx_res_w == RES_MATCH)
4241 break; /* we are in case's "word | word)" */
4243 if (next == '|') { /* || */
4245 done_pipe(ctx, PIPE_OR);
4247 /* we could pick up a file descriptor choice here
4248 * with redirect_opt_num(), but bash doesn't do it.
4249 * "echo foo 2| cat" yields "foo 2". */
4254 #if ENABLE_HUSH_CASE
4255 /* "case... in [(]word)..." - skip '(' */
4256 if (ctx->ctx_res_w == RES_MATCH
4257 && ctx->command->argv == NULL /* not (word|(... */
4258 && dest->length == 0 /* not word(... */
4259 && dest->nonnull == 0 /* not ""(... */
4264 #if ENABLE_HUSH_FUNCTIONS
4265 if (dest->length != 0 /* not just () but word() */
4266 && dest->nonnull == 0 /* not a"b"c() */
4267 && ctx->command->argv == NULL /* it's the first word */
4268 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4269 && i_peek(input) == ')'
4270 && !match_reserved_word(dest)
4272 bb_error_msg("seems like a function definition");
4275 //TODO: do it properly.
4276 ch = i_getch(input);
4277 } while (ch == ' ' || ch == '\n');
4279 syntax("was expecting {");
4280 debug_printf_parse("parse_stream return 1\n");
4283 ch = 'F'; /* magic value */
4287 if (parse_group(dest, ctx, input, ch) != 0) {
4288 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
4293 #if ENABLE_HUSH_CASE
4294 if (ctx->ctx_res_w == RES_MATCH)
4298 /* proper use of this character is caught by end_trigger:
4299 * if we see {, we call parse_group(..., end_trigger='}')
4300 * and it will match } earlier (not here). */
4301 syntax("unexpected } or )");
4302 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
4306 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4309 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
4315 static void set_in_charmap(const char *set, int code)
4318 G.charmap[(unsigned char)*set++] = code;
4321 static void update_charmap(void)
4323 G.ifs = getenv("IFS");
4326 /* Precompute a list of 'flow through' behavior so it can be treated
4327 * quickly up front. Computation is necessary because of IFS.
4328 * Special case handling of IFS == " \t\n" is not implemented.
4329 * The charmap[] array only really needs two bits each,
4330 * and on most machines that would be faster (reduced L1 cache use).
4332 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4333 #if ENABLE_HUSH_TICK
4334 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4336 set_in_charmap("\\$\"", CHAR_SPECIAL);
4338 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4339 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4342 /* Most recursion does not come through here, the exception is
4343 * from builtin_source() and builtin_eval() */
4344 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
4346 struct parse_context ctx;
4347 o_string temp = NULL_O_STRING;
4351 initialize_context(&ctx);
4353 #if ENABLE_HUSH_INTERACTIVE
4354 inp->promptmode = 0; /* PS1 */
4356 /* We will stop & execute after each ';' or '\n'.
4357 * Example: "sleep 9999; echo TEST" + ctrl-C:
4358 * TEST should be printed */
4359 temp.o_assignment = MAYBE_ASSIGNMENT;
4360 rcode = parse_stream(&temp, &ctx, inp, ";\n");
4362 if (rcode != 1 && ctx.old_flag != 0) {
4366 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
4367 done_word(&temp, &ctx);
4368 done_pipe(&ctx, PIPE_SEQ);
4369 debug_print_tree(ctx.list_head, 0);
4370 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
4371 run_and_free_list(ctx.list_head);
4373 /* We arrive here also if rcode == 1 (error in parse_stream) */
4375 if (ctx.old_flag != 0) {
4380 /*temp.nonnull = 0; - o_free does it below */
4381 /*temp.o_quote = 0; - o_free does it below */
4382 free_pipe_list(ctx.list_head, /* indent: */ 0);
4383 /* Discard all unprocessed line input, force prompt on */
4385 #if ENABLE_HUSH_INTERACTIVE
4390 /* loop on syntax errors, return on EOF: */
4391 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
4395 static int parse_and_run_string(const char *s, int parse_flag)
4397 struct in_str input;
4398 setup_string_in_str(&input, s);
4399 return parse_and_run_stream(&input, parse_flag);
4402 static int parse_and_run_file(FILE *f)
4405 struct in_str input;
4406 setup_file_in_str(&input, f);
4407 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
4412 /* Make sure we have a controlling tty. If we get started under a job
4413 * aware app (like bash for example), make sure we are now in charge so
4414 * we don't fight over who gets the foreground */
4415 static void setup_job_control(void)
4419 shell_pgrp = getpgrp();
4421 /* If we were ran as 'hush &',
4422 * sleep until we are in the foreground. */
4423 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4424 /* Send TTIN to ourself (should stop us) */
4425 kill(- shell_pgrp, SIGTTIN);
4426 shell_pgrp = getpgrp();
4429 /* We _must_ restore tty pgrp on fatal signals */
4430 set_fatal_signals_to_sigexit();
4432 /* Put ourselves in our own process group. */
4433 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4434 /* Grab control of the terminal. */
4435 tcsetpgrp(G.interactive_fd, getpid());
4439 static int set_mode(const char cstate, const char mode)
4441 int state = (cstate == '-' ? 1 : 0);
4443 case 'n': G.fake_mode = state; break;
4444 case 'x': /*G.debug_mode = state;*/ break;
4445 default: return EXIT_FAILURE;
4447 return EXIT_SUCCESS;
4450 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4451 int hush_main(int argc, char **argv)
4453 static const struct variable const_shell_ver = {
4455 .varstr = (char*)hush_version_str,
4456 .max_len = 1, /* 0 can provoke free(name) */
4464 struct variable *cur_var;
4468 G.root_pid = getpid();
4470 /* Deal with HUSH_VERSION */
4471 G.shell_ver = const_shell_ver; /* copying struct here */
4472 G.top_var = &G.shell_ver;
4473 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4474 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4475 /* Initialize our shell local variables with the values
4476 * currently living in the environment */
4477 cur_var = G.top_var;
4480 char *value = strchr(*e, '=');
4481 if (value) { /* paranoia */
4482 cur_var->next = xzalloc(sizeof(*cur_var));
4483 cur_var = cur_var->next;
4484 cur_var->varstr = *e;
4485 cur_var->max_len = strlen(*e);
4486 cur_var->flg_export = 1;
4490 debug_printf_env("putenv '%s'\n", hush_version_str);
4491 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4493 #if ENABLE_FEATURE_EDITING
4494 G.line_input_state = new_line_input_t(FOR_SHELL);
4496 /* XXX what should these be while sourcing /etc/profile? */
4497 G.global_argc = argc;
4498 G.global_argv = argv;
4499 /* Initialize some more globals to non-zero values */
4501 #if ENABLE_HUSH_INTERACTIVE
4502 if (ENABLE_FEATURE_EDITING)
4503 cmdedit_set_initial_prompt();
4507 if (EXIT_SUCCESS) /* otherwise is already done */
4508 G.last_return_code = EXIT_SUCCESS;
4510 if (argv[0] && argv[0][0] == '-') {
4511 debug_printf("sourcing /etc/profile\n");
4512 input = fopen_for_read("/etc/profile");
4513 if (input != NULL) {
4514 close_on_exec_on(fileno(input));
4515 parse_and_run_file(input);
4521 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4522 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4525 G.global_argv = argv + optind;
4526 if (!argv[optind]) {
4527 /* -c 'script' (no params): prevent empty $0 */
4528 *--G.global_argv = argv[0];
4530 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4531 G.global_argc = argc - optind;
4532 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
4535 /* Well, we cannot just declare interactiveness,
4536 * we have to have some stuff (ctty, etc) */
4537 /* G.interactive_fd++; */
4540 /* "-s" means "read from stdin", but this is how we always
4541 * operate, so simply do nothing here. */
4545 if (!set_mode('-', opt))
4549 fprintf(stderr, "Usage: sh [FILE]...\n"
4550 " or: sh -c command [args]...\n\n");
4558 /* A shell is interactive if the '-i' flag was given, or if all of
4559 * the following conditions are met:
4561 * no arguments remaining or the -s flag given
4562 * standard input is a terminal
4563 * standard output is a terminal
4564 * Refer to Posix.2, the description of the 'sh' utility. */
4565 if (argv[optind] == NULL && input == stdin
4566 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4568 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4569 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4570 if (G.saved_tty_pgrp >= 0) {
4571 /* try to dup to high fd#, >= 255 */
4572 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4573 if (G.interactive_fd < 0) {
4574 /* try to dup to any fd */
4575 G.interactive_fd = dup(STDIN_FILENO);
4576 if (G.interactive_fd < 0)
4578 G.interactive_fd = 0;
4580 // TODO: track & disallow any attempts of user
4581 // to (inadvertently) close/redirect it
4585 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4586 if (G.interactive_fd) {
4587 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4588 /* Looks like they want an interactive shell */
4589 setup_job_control();
4590 /* -1 is special - makes xfuncs longjmp, not exit
4591 * (we reset die_sleep = 0 whereever we [v]fork) */
4593 if (setjmp(die_jmp)) {
4594 /* xfunc has failed! die die die */
4595 hush_exit(xfunc_error_retval);
4598 #elif ENABLE_HUSH_INTERACTIVE
4599 /* no job control compiled, only prompt/line editing */
4600 if (argv[optind] == NULL && input == stdin
4601 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4603 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4604 if (G.interactive_fd < 0) {
4605 /* try to dup to any fd */
4606 G.interactive_fd = dup(STDIN_FILENO);
4607 if (G.interactive_fd < 0)
4609 G.interactive_fd = 0;
4611 if (G.interactive_fd) {
4612 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4618 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4619 if (G.interactive_fd) {
4620 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4621 printf("Enter 'help' for a list of built-in commands.\n\n");
4625 if (argv[optind] == NULL) {
4626 opt = parse_and_run_file(stdin);
4628 debug_printf("\nrunning script '%s'\n", argv[optind]);
4629 G.global_argv = argv + optind;
4630 G.global_argc = argc - optind;
4631 input = xfopen_for_read(argv[optind]);
4632 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4633 opt = parse_and_run_file(input);
4638 #if ENABLE_FEATURE_CLEAN_UP
4640 if (G.cwd != bb_msg_unknown)
4642 cur_var = G.top_var->next;
4644 struct variable *tmp = cur_var;
4645 if (!cur_var->max_len)
4646 free(cur_var->varstr);
4647 cur_var = cur_var->next;
4651 hush_exit(opt ? opt : G.last_return_code);
4656 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4657 int lash_main(int argc, char **argv)
4659 //bb_error_msg("lash is deprecated, please use hush instead");
4660 return hush_main(argc, argv);
4668 static int builtin_trap(char **argv)
4675 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4678 /* No args: print all trapped. This isn't 100% correct as we should
4679 * be escaping the cmd so that it can be pasted back in ...
4681 for (i = 0; i < NSIG; ++i)
4683 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4684 return EXIT_SUCCESS;
4689 /* if first arg is decimal: reset all specified */
4690 sig = bb_strtou(*++argv, NULL, 10);
4696 sig = get_signum(*argv++);
4697 if (sig < 0 || sig >= NSIG) {
4699 /* mimic bash message exactly */
4700 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4705 G.traps[sig] = xstrdup(new_cmd);
4707 debug_printf("trap: setting SIG%s (%i) to '%s'",
4708 get_signame(sig), sig, G.traps[sig]);
4710 /* There is no signal for 0 (EXIT) */
4715 sigaddset(&G.blocked_set, sig);
4717 /* there was a trap handler, we are removing it
4718 * (if sig has non-DFL handling,
4719 * we don't need to do anything) */
4720 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4722 sigdelset(&G.blocked_set, sig);
4724 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4729 /* first arg is "-": reset all specified to default */
4730 /* first arg is "": ignore all specified */
4731 /* everything else: execute first arg upon signal */
4733 bb_error_msg("trap: invalid arguments");
4734 return EXIT_FAILURE;
4736 if (LONE_DASH(*argv))
4744 static int builtin_true(char **argv UNUSED_PARAM)
4749 static int builtin_test(char **argv)
4756 return test_main(argc, argv - argc);
4759 static int builtin_echo(char **argv)
4766 return echo_main(argc, argv - argc);
4769 static int builtin_eval(char **argv)
4771 int rcode = EXIT_SUCCESS;
4774 char *str = expand_strvec_to_string(argv + 1);
4775 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4777 rcode = G.last_return_code;
4782 static int builtin_cd(char **argv)
4785 if (argv[1] == NULL) {
4786 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4787 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4788 newdir = getenv("HOME") ? : "/";
4791 if (chdir(newdir)) {
4792 printf("cd: %s: %s\n", newdir, strerror(errno));
4793 return EXIT_FAILURE;
4796 return EXIT_SUCCESS;
4799 static int builtin_exec(char **argv)
4801 if (argv[1] == NULL)
4802 return EXIT_SUCCESS; /* bash does this */
4807 // FIXME: if exec fails, bash does NOT exit! We do...
4808 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
4813 static int builtin_exit(char **argv)
4815 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4816 //puts("exit"); /* bash does it */
4817 // TODO: warn if we have background jobs: "There are stopped jobs"
4818 // On second consecutive 'exit', exit anyway.
4819 if (argv[1] == NULL)
4820 hush_exit(G.last_return_code);
4821 /* mimic bash: exit 123abc == exit 255 + error msg */
4822 xfunc_error_retval = 255;
4823 /* bash: exit -2 == exit 254, no error msg */
4824 hush_exit(xatoi(argv[1]) & 0xff);
4827 static int builtin_export(char **argv)
4830 char *name = argv[1];
4834 // ash emits: export VAR='VAL'
4835 // bash: declare -x VAR="VAL"
4836 // (both also escape as needed (quotes, $, etc))
4841 return EXIT_SUCCESS;
4844 value = strchr(name, '=');
4846 /* They are exporting something without a =VALUE */
4847 struct variable *var;
4849 var = get_local_var(name);
4851 var->flg_export = 1;
4852 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
4853 putenv(var->varstr);
4855 /* bash does not return an error when trying to export
4856 * an undefined variable. Do likewise. */
4857 return EXIT_SUCCESS;
4860 set_local_var(xstrdup(name), 1);
4861 return EXIT_SUCCESS;
4865 /* built-in 'fg' and 'bg' handler */
4866 static int builtin_fg_bg(char **argv)
4871 if (!G.interactive_fd)
4872 return EXIT_FAILURE;
4873 /* If they gave us no args, assume they want the last backgrounded task */
4875 for (pi = G.job_list; pi; pi = pi->next) {
4876 if (pi->jobid == G.last_jobid) {
4880 bb_error_msg("%s: no current job", argv[0]);
4881 return EXIT_FAILURE;
4883 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4884 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4885 return EXIT_FAILURE;
4887 for (pi = G.job_list; pi; pi = pi->next) {
4888 if (pi->jobid == jobnum) {
4892 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4893 return EXIT_FAILURE;
4895 // TODO: bash prints a string representation
4896 // of job being foregrounded (like "sleep 1 | cat")
4897 if (*argv[0] == 'f') {
4898 /* Put the job into the foreground. */
4899 tcsetpgrp(G.interactive_fd, pi->pgrp);
4902 /* Restart the processes in the job */
4903 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
4904 for (i = 0; i < pi->num_cmds; i++) {
4905 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
4906 pi->cmds[i].is_stopped = 0;
4908 pi->stopped_cmds = 0;
4910 i = kill(- pi->pgrp, SIGCONT);
4912 if (errno == ESRCH) {
4913 delete_finished_bg_job(pi);
4914 return EXIT_SUCCESS;
4916 bb_perror_msg("kill (SIGCONT)");
4920 if (*argv[0] == 'f') {
4922 return checkjobs_and_fg_shell(pi);
4924 return EXIT_SUCCESS;
4928 #if ENABLE_HUSH_HELP
4929 static int builtin_help(char **argv UNUSED_PARAM)
4931 const struct built_in_command *x;
4933 printf("\nBuilt-in commands:\n");
4934 printf("-------------------\n");
4935 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
4936 printf("%s\t%s\n", x->cmd, x->descr);
4939 return EXIT_SUCCESS;
4944 static int builtin_jobs(char **argv UNUSED_PARAM)
4947 const char *status_string;
4949 for (job = G.job_list; job; job = job->next) {
4950 if (job->alive_cmds == job->stopped_cmds)
4951 status_string = "Stopped";
4953 status_string = "Running";
4955 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
4957 return EXIT_SUCCESS;
4961 static int builtin_pwd(char **argv UNUSED_PARAM)
4964 return EXIT_SUCCESS;
4967 static int builtin_read(char **argv)
4970 const char *name = argv[1] ? argv[1] : "REPLY";
4972 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
4973 return set_local_var(string, 0);
4976 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
4977 * built-in 'set' handler
4979 * set [-abCefhmnuvx] [-o option] [argument...]
4980 * set [+abCefhmnuvx] [+o option] [argument...]
4981 * set -- [argument...]
4984 * Implementations shall support the options in both their hyphen and
4985 * plus-sign forms. These options can also be specified as options to sh.
4987 * Write out all variables and their values: set
4988 * Set $1, $2, and $3 and set "$#" to 3: set c a b
4989 * Turn on the -x and -v options: set -xv
4990 * Unset all positional parameters: set --
4991 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
4992 * Set the positional parameters to the expansion of x, even if x expands
4993 * with a leading '-' or '+': set -- $x
4995 * So far, we only support "set -- [argument...]" and some of the short names.
4997 static int builtin_set(char **argv)
5000 char **pp, **g_argv;
5001 char *arg = *++argv;
5005 for (e = G.top_var; e; e = e->next)
5007 return EXIT_SUCCESS;
5011 if (!strcmp(arg, "--")) {
5016 if (arg[0] == '+' || arg[0] == '-') {
5017 for (n = 1; arg[n]; ++n)
5018 if (set_mode(arg[0], arg[n]))
5024 } while ((arg = *++argv) != NULL);
5025 /* Now argv[0] is 1st argument */
5027 /* Only reset global_argv if we didn't process anything */
5029 return EXIT_SUCCESS;
5032 /* NB: G.global_argv[0] ($0) is never freed/changed */
5033 g_argv = G.global_argv;
5034 if (G.global_args_malloced) {
5040 G.global_args_malloced = 1;
5041 pp = xzalloc(sizeof(pp[0]) * 2);
5042 pp[0] = g_argv[0]; /* retain $0 */
5045 /* This realloc's G.global_argv */
5046 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5053 return EXIT_SUCCESS;
5055 /* Nothing known, so abort */
5057 bb_error_msg("set: %s: invalid option", arg);
5058 return EXIT_FAILURE;
5061 static int builtin_shift(char **argv)
5067 if (n >= 0 && n < G.global_argc) {
5068 if (G.global_args_malloced) {
5071 free(G.global_argv[m++]);
5074 memmove(&G.global_argv[1], &G.global_argv[n+1],
5075 G.global_argc * sizeof(G.global_argv[0]));
5076 return EXIT_SUCCESS;
5078 return EXIT_FAILURE;
5081 static int builtin_source(char **argv)
5086 if (argv[1] == NULL)
5087 return EXIT_FAILURE;
5089 /* XXX search through $PATH is missing */
5090 input = fopen_for_read(argv[1]);
5092 bb_error_msg("can't open '%s'", argv[1]);
5093 return EXIT_FAILURE;
5095 close_on_exec_on(fileno(input));
5097 /* Now run the file */
5098 /* XXX argv and argc are broken; need to save old G.global_argv
5099 * (pointer only is OK!) on this stack frame,
5100 * set G.global_argv=argv+1, recurse, and restore. */
5101 status = parse_and_run_file(input);
5106 static int builtin_umask(char **argv)
5109 const char *arg = argv[1];
5111 new_umask = bb_strtou(arg, NULL, 8);
5113 return EXIT_FAILURE;
5115 new_umask = umask(0);
5116 printf("%.3o\n", (unsigned) new_umask);
5119 return EXIT_SUCCESS;
5122 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5123 static int builtin_unset(char **argv)
5130 return EXIT_SUCCESS;
5133 if (argv[1][0] == '-') {
5134 switch (argv[1][1]) {
5136 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5138 bb_error_msg("unset: %s: invalid option", argv[1]);
5139 return EXIT_FAILURE;
5147 if (unset_local_var(argv[i]))
5150 #if ENABLE_HUSH_FUNCTIONS
5152 unset_local_func(argv[i]);
5158 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5159 static int builtin_wait(char **argv)
5161 int ret = EXIT_SUCCESS;
5164 if (*++argv == NULL)
5165 /* don't care about exit status */
5169 pid_t pid = bb_strtou(*argv, NULL, 10);
5171 /* mimic bash message */
5172 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5173 return EXIT_FAILURE;
5175 if (waitpid(pid, &status, 0) == pid) {
5176 if (WIFSIGNALED(status))
5177 ret = 128 + WTERMSIG(status);
5178 else if (WIFEXITED(status))
5179 ret = WEXITSTATUS(status);
5183 bb_perror_msg("wait %s", *argv);
5192 #if ENABLE_HUSH_LOOPS
5193 static int builtin_break(char **argv)
5195 if (G.depth_of_loop == 0) {
5196 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5197 return EXIT_SUCCESS; /* bash compat */
5199 G.flag_break_continue++; /* BC_BREAK = 1 */
5200 G.depth_break_continue = 1;
5202 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5203 if (errno || !G.depth_break_continue || argv[2]) {
5204 bb_error_msg("%s: bad arguments", argv[0]);
5205 G.flag_break_continue = BC_BREAK;
5206 G.depth_break_continue = UINT_MAX;
5209 if (G.depth_of_loop < G.depth_break_continue)
5210 G.depth_break_continue = G.depth_of_loop;
5211 return EXIT_SUCCESS;
5214 static int builtin_continue(char **argv)
5216 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5217 return builtin_break(argv);
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