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 // unsigned count_SIGCHLD;
495 // unsigned handled_SIGCHLD;
496 /* which signals have non-DFL handler (even with no traps set)? */
497 unsigned non_DFL_mask;
498 char **traps; /* char *traps[NSIG] */
499 sigset_t blocked_set;
500 sigset_t inherited_set;
502 #define G (*ptr_to_globals)
503 /* Not #defining name to G.name - this quickly gets unwieldy
504 * (too many defines). Also, I actually prefer to see when a variable
505 * is global, thus "G." prefix is a useful hint */
506 #define INIT_G() do { \
507 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
511 /* Function prototypes for builtins */
512 static int builtin_cd(char **argv);
513 static int builtin_echo(char **argv);
514 static int builtin_eval(char **argv);
515 static int builtin_exec(char **argv);
516 static int builtin_exit(char **argv);
517 static int builtin_export(char **argv);
519 static int builtin_fg_bg(char **argv);
520 static int builtin_jobs(char **argv);
523 static int builtin_help(char **argv);
525 static int builtin_pwd(char **argv);
526 static int builtin_read(char **argv);
527 static int builtin_test(char **argv);
528 static int builtin_trap(char **argv);
529 static int builtin_true(char **argv);
530 static int builtin_set(char **argv);
531 static int builtin_shift(char **argv);
532 static int builtin_source(char **argv);
533 static int builtin_umask(char **argv);
534 static int builtin_unset(char **argv);
535 static int builtin_wait(char **argv);
536 #if ENABLE_HUSH_LOOPS
537 static int builtin_break(char **argv);
538 static int builtin_continue(char **argv);
540 //static int builtin_not_written(char **argv);
542 /* Table of built-in functions. They can be forked or not, depending on
543 * context: within pipes, they fork. As simple commands, they do not.
544 * When used in non-forking context, they can change global variables
545 * in the parent shell process. If forked, of course they cannot.
546 * For example, 'unset foo | whatever' will parse and run, but foo will
547 * still be set at the end. */
548 struct built_in_command {
550 int (*function)(char **argv);
553 #define BLTIN(cmd, func, help) { cmd, func, help }
555 #define BLTIN(cmd, func, help) { cmd, func }
559 /* For now, echo and test are unconditionally enabled.
560 * Maybe make it configurable? */
561 static const struct built_in_command bltins[] = {
562 BLTIN("." , builtin_source, "Run commands in a file"),
563 BLTIN(":" , builtin_true, "No-op"),
564 BLTIN("[" , builtin_test, "Test condition"),
566 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
568 #if ENABLE_HUSH_LOOPS
569 BLTIN("break" , builtin_break, "Exit from a loop"),
571 BLTIN("cd" , builtin_cd, "Change directory"),
572 #if ENABLE_HUSH_LOOPS
573 BLTIN("continue", builtin_continue, "Start new loop iteration"),
575 BLTIN("echo" , builtin_echo, "Write to stdout"),
576 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
577 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
578 BLTIN("exit" , builtin_exit, "Exit"),
579 BLTIN("export", builtin_export, "Set environment variable"),
581 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
582 BLTIN("jobs" , builtin_jobs, "List active jobs"),
584 BLTIN("pwd" , builtin_pwd, "Print current directory"),
585 BLTIN("read" , builtin_read, "Input environment variable"),
586 // BLTIN("return", builtin_not_written, "Return from a function"),
587 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
588 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
589 BLTIN("test" , builtin_test, "Test condition"),
590 BLTIN("trap" , builtin_trap, "Trap signals"),
591 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
592 BLTIN("umask" , builtin_umask, "Set file creation mask"),
593 BLTIN("unset" , builtin_unset, "Unset environment variable"),
594 BLTIN("wait" , builtin_wait, "Wait for process"),
596 BLTIN("help" , builtin_help, "List shell built-in commands"),
602 static void maybe_die(const char *notice, const char *msg)
604 /* Was using fancy stuff:
605 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
606 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
607 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
608 #if ENABLE_HUSH_INTERACTIVE
609 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
611 fp(msg ? "%s: %s" : notice, notice, msg);
614 #define syntax(msg) maybe_die("syntax error", msg);
616 /* Debug -- trick gcc to expand __LINE__ and convert to string */
617 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
618 #define _syntax(msg, line) __syntax(msg, line)
619 #define syntax(msg) _syntax(msg, __LINE__)
622 static int glob_needed(const char *s)
627 if (*s == '*' || *s == '[' || *s == '?')
634 static int is_assignment(const char *s)
636 if (!s || !(isalpha(*s) || *s == '_'))
639 while (isalnum(*s) || *s == '_')
644 /* Replace each \x with x in place, return ptr past NUL. */
645 static char *unbackslash(char *src)
651 if ((*dst++ = *src++) == '\0')
657 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
678 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
679 v[count1 + count2] = NULL;
682 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
686 static char **add_string_to_strings(char **strings, char *add)
691 return add_strings_to_strings(strings, v, /*dup:*/ 0);
694 static void putenv_all(char **strings)
699 debug_printf_env("putenv '%s'\n", *strings);
704 static char **putenv_all_and_save_old(char **strings)
714 eq = strchr(*strings, '=');
717 v = getenv(*strings);
720 /* v points to VAL in VAR=VAL, go back to VAR */
721 v -= (eq - *strings) + 1;
722 old = add_string_to_strings(old, v);
731 static void free_strings_and_unsetenv(char **strings, int unset)
741 debug_printf_env("unsetenv '%s'\n", *v);
749 static void free_strings(char **strings)
751 free_strings_and_unsetenv(strings, 0);
755 /* Basic theory of signal handling in shell
756 * ========================================
757 * This does not describe what hush does, rather, it is current understanding
758 * what it _should_ do. If it doesn't, it's a bug.
759 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
761 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
762 * is finished or backgrounded. It is the same in interactive and
763 * non-interactive shells, and is the same regardless of whether
764 * a user trap handler is installed or a shell special one is in effect.
765 * ^C or ^Z from keyboard seem to execute "at once" because it usually
766 * backgrounds (i.e. stops) or kills all members of currently running
769 * Wait builtin in interruptible by signals for which user trap is set
770 * or by SIGINT in interactive shell.
772 * Trap handlers will execute even within trap handlers. (right?)
774 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
776 * If job control is off, backgrounded commands ("cmd &")
777 * have SIGINT, SIGQUIT set to SIG_IGN.
779 * Commands run in command substitution ("`cmd`")
780 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
782 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
783 * by the shell from its parent.
785 * Siganls which differ from SIG_DFL action
786 * (note: child (i.e., [v]forked) shell is not an interactive shell):
789 * SIGTERM (interactive): ignore
790 * SIGHUP (interactive):
791 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
792 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
793 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
794 * that all pipe members are stopped) (right?)
795 * SIGINT (interactive): wait for last pipe, ignore the rest
796 * of the command line, show prompt. NB: ^C does not send SIGINT
797 * to interactive shell while shell is waiting for a pipe,
798 * since shell is bg'ed (is not in foreground process group).
799 * (check/expand this)
800 * Example 1: this waits 5 sec, but does not execute ls:
801 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
802 * Example 2: this does not wait and does not execute ls:
803 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
804 * Example 3: this does not wait 5 sec, but executes ls:
805 * "sleep 5; ls -l" + press ^C
807 * (What happens to signals which are IGN on shell start?)
808 * (What happens with signal mask on shell start?)
810 * Implementation in hush
811 * ======================
812 * We use in-kernel pending signal mask to determine which signals were sent.
813 * We block all signals which we don't want to take action immediately,
814 * i.e. we block all signals which need to have special handling as described
815 * above, and all signals which have traps set.
816 * After each pipe execution, we extract any pending signals via sigtimedwait()
819 * unsigned non_DFL_mask: a mask of such "special" signals
820 * sigset_t blocked_set: current blocked signal set
823 * clear bit in blocked_set unless it is also in non_DFL
824 * "trap 'cmd' SIGxxx":
825 * set bit in blocked_set (even if 'cmd' is '')
826 * after [v]fork, if we plan to be a shell:
827 * nothing for {} child shell (say, "true | { true; true; } | true")
828 * unset all traps if () shell. [TODO]
829 * after [v]fork, if we plan to exec:
830 * POSIX says pending signal mask is cleared in child - no need to clear it.
831 * Restore blocked signal set to one inherited by shell just prior to exec.
833 * Note: as a result, we do not use signal handlers much. The only uses
834 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
835 * and to restore tty pgrp on signal-induced exit.
837 * TODO: check/fix wait builtin to be interruptible.
840 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
842 // G.count_SIGCHLD++;
845 /* called once at shell init */
846 static void init_signal_mask(void)
849 unsigned mask = (1 << SIGQUIT);
850 #if ENABLE_HUSH_INTERACTIVE
851 if (G.interactive_fd) {
857 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
863 G.non_DFL_mask = mask;
865 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
869 sigaddset(&G.blocked_set, sig);
873 sigdelset(&G.blocked_set, SIGCHLD);
874 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
877 static int check_and_run_traps(int sig)
879 static const struct timespec zero_timespec = { 0, 0 };
880 smalluint save_rcode;
886 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
891 if (G.traps && G.traps[sig]) {
892 if (G.traps[sig][0]) {
893 /* We have user-defined handler */
894 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
895 save_rcode = G.last_return_code;
898 G.last_return_code = save_rcode;
899 } /* else: "" trap, ignoring signal */
902 /* not a trap: special action */
905 // G.count_SIGCHLD++;
914 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
923 /* Restores tty foreground process group, and exits.
924 * May be called as signal handler for fatal signal
925 * (will faithfully resend signal to itself, producing correct exit state)
926 * or called directly with -EXITCODE.
927 * We also call it if xfunc is exiting. */
928 static void sigexit(int sig) NORETURN;
929 static void sigexit(int sig)
931 /* Disable all signals: job control, SIGPIPE, etc. */
932 sigprocmask_allsigs(SIG_BLOCK);
934 #if ENABLE_HUSH_INTERACTIVE
935 /* Careful: we can end up here after [v]fork. Do not restore
936 * tty pgrp then, only top-level shell process does that */
937 if (G.interactive_fd && getpid() == G.root_pid)
938 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
941 /* Not a signal, just exit */
945 kill_myself_with_sig(sig); /* does not return */
949 static void maybe_set_sighandler(int sig)
951 void (*handler)(int);
952 /* non_DFL_mask'ed signals are, well, masked,
953 * no need to set handler for them.
955 if (!((G.non_DFL_mask >> sig) & 1)) {
956 handler = signal(sig, sigexit);
957 if (handler == SIG_IGN) /* oops... restore back to IGN! */
958 signal(sig, handler);
961 /* Used only to set handler to restore pgrp on exit */
962 static void set_fatal_signals_to_sigexit(void)
965 maybe_set_sighandler(SIGILL );
966 maybe_set_sighandler(SIGFPE );
967 maybe_set_sighandler(SIGBUS );
968 maybe_set_sighandler(SIGSEGV);
969 maybe_set_sighandler(SIGTRAP);
970 } /* else: hush is perfect. what SEGV? */
972 maybe_set_sighandler(SIGABRT);
974 /* bash 3.2 seems to handle these just like 'fatal' ones */
975 maybe_set_sighandler(SIGPIPE);
976 maybe_set_sighandler(SIGALRM);
977 maybe_set_sighandler(SIGHUP );
979 /* if we aren't interactive... but in this case
980 * we never want to restore pgrp on exit, and this fn is not called */
981 /*maybe_set_sighandler(SIGTERM);*/
982 /*maybe_set_sighandler(SIGINT );*/
984 /* Used only to suppress ^Z in `cmd` */
985 static void set_jobctrl_signals_to_IGN(void)
996 #define set_fatal_signals_to_sigexit(handler) ((void)0)
997 #define set_jobctrl_signals_to_IGN(handler) ((void)0)
1001 /* Restores tty foreground process group, and exits. */
1002 static void hush_exit(int exitcode) NORETURN;
1003 static void hush_exit(int exitcode)
1005 if (G.traps && G.traps[0] && G.traps[0][0]) {
1006 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1012 fflush(NULL); /* flush all streams */
1013 sigexit(- (exitcode & 0xff));
1020 static const char *set_cwd(void)
1022 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1023 * we must not try to free(bb_msg_unknown) */
1024 if (G.cwd == bb_msg_unknown)
1026 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1028 G.cwd = bb_msg_unknown;
1033 /* Get/check local shell variables */
1034 static struct variable *get_local_var(const char *name)
1036 struct variable *cur;
1042 for (cur = G.top_var; cur; cur = cur->next) {
1043 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1049 /* Basically useful version until someone wants to get fancier,
1050 * see the bash man page under "Parameter Expansion" */
1051 static const char *lookup_param(const char *src)
1053 struct variable *var = get_local_var(src);
1055 return strchr(var->varstr, '=') + 1;
1059 /* str holds "NAME=VAL" and is expected to be malloced.
1060 * We take ownership of it.
1061 * flg_export is used by:
1064 * -1: if NAME is set, leave export status alone
1065 * if NAME is not set, do not export
1067 static int set_local_var(char *str, int flg_export)
1069 struct variable *cur;
1073 value = strchr(str, '=');
1074 if (!value) { /* not expected to ever happen? */
1079 name_len = value - str + 1; /* including '=' */
1080 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1082 if (strncmp(cur->varstr, str, name_len) != 0) {
1084 /* Bail out. Note that now cur points
1085 * to last var in linked list */
1091 /* We found an existing var with this name */
1093 if (cur->flg_read_only) {
1094 bb_error_msg("%s: readonly variable", str);
1098 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1099 unsetenv(str); /* just in case */
1101 if (strcmp(cur->varstr, str) == 0) {
1106 if (cur->max_len >= strlen(str)) {
1107 /* This one is from startup env, reuse space */
1108 strcpy(cur->varstr, str);
1111 /* max_len == 0 signifies "malloced" var, which we can
1112 * (and has to) free */
1116 goto set_str_and_exp;
1119 /* Not found - create next variable struct */
1120 cur->next = xzalloc(sizeof(*cur));
1126 if (flg_export == 1)
1127 cur->flg_export = 1;
1128 if (cur->flg_export) {
1129 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1130 return putenv(cur->varstr);
1135 static int unset_local_var(const char *name)
1137 struct variable *cur;
1138 struct variable *prev = prev; /* for gcc */
1142 return EXIT_SUCCESS;
1143 name_len = strlen(name);
1146 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1147 if (cur->flg_read_only) {
1148 bb_error_msg("%s: readonly variable", name);
1149 return EXIT_FAILURE;
1151 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1152 * is ro, and we cannot reach this code on the 1st pass */
1153 prev->next = cur->next;
1154 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1155 bb_unsetenv(cur->varstr);
1159 return EXIT_SUCCESS;
1164 return EXIT_SUCCESS;
1171 static int static_get(struct in_str *i)
1174 if (ch == '\0') return EOF;
1178 static int static_peek(struct in_str *i)
1183 #if ENABLE_HUSH_INTERACTIVE
1185 static void cmdedit_set_initial_prompt(void)
1187 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1188 G.PS1 = getenv("PS1");
1195 static const char* setup_prompt_string(int promptmode)
1197 const char *prompt_str;
1198 debug_printf("setup_prompt_string %d ", promptmode);
1199 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1200 /* Set up the prompt */
1201 if (promptmode == 0) { /* PS1 */
1203 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1208 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1209 debug_printf("result '%s'\n", prompt_str);
1213 static void get_user_input(struct in_str *i)
1216 const char *prompt_str;
1218 prompt_str = setup_prompt_string(i->promptmode);
1219 #if ENABLE_FEATURE_EDITING
1220 /* Enable command line editing only while a command line
1221 * is actually being read */
1224 /* buglet: SIGINT will not make new prompt to appear _at once_,
1225 * only after <Enter>. (^C will work) */
1226 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1227 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1228 check_and_run_traps(0);
1229 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1230 i->eof_flag = (r < 0);
1231 if (i->eof_flag) { /* EOF/error detected */
1232 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1233 G.user_input_buf[1] = '\0';
1238 fputs(prompt_str, stdout);
1240 G.user_input_buf[0] = r = fgetc(i->file);
1241 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1242 //do we need check_and_run_traps(0)? (maybe only if stdin)
1243 } while (G.flag_SIGINT);
1244 i->eof_flag = (r == EOF);
1246 i->p = G.user_input_buf;
1249 #endif /* INTERACTIVE */
1251 /* This is the magic location that prints prompts
1252 * and gets data back from the user */
1253 static int file_get(struct in_str *i)
1257 /* If there is data waiting, eat it up */
1258 if (i->p && *i->p) {
1259 #if ENABLE_HUSH_INTERACTIVE
1263 if (i->eof_flag && !*i->p)
1266 /* need to double check i->file because we might be doing something
1267 * more complicated by now, like sourcing or substituting. */
1268 #if ENABLE_HUSH_INTERACTIVE
1269 if (G.interactive_fd && i->promptme && i->file == stdin) {
1272 } while (!*i->p); /* need non-empty line */
1273 i->promptmode = 1; /* PS2 */
1278 ch = fgetc(i->file);
1280 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1281 #if ENABLE_HUSH_INTERACTIVE
1288 /* All the callers guarantee this routine will never be
1289 * used right after a newline, so prompting is not needed.
1291 static int file_peek(struct in_str *i)
1294 if (i->p && *i->p) {
1295 if (i->eof_flag && !i->p[1])
1299 ch = fgetc(i->file);
1300 i->eof_flag = (ch == EOF);
1301 i->peek_buf[0] = ch;
1302 i->peek_buf[1] = '\0';
1304 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1308 static void setup_file_in_str(struct in_str *i, FILE *f)
1310 i->peek = file_peek;
1312 #if ENABLE_HUSH_INTERACTIVE
1314 i->promptmode = 0; /* PS1 */
1320 static void setup_string_in_str(struct in_str *i, const char *s)
1322 i->peek = static_peek;
1323 i->get = static_get;
1324 #if ENABLE_HUSH_INTERACTIVE
1326 i->promptmode = 0; /* PS1 */
1336 #define B_CHUNK (32 * sizeof(char*))
1338 static void o_reset(o_string *o)
1346 static void o_free(o_string *o)
1349 memset(o, 0, sizeof(*o));
1352 static void o_grow_by(o_string *o, int len)
1354 if (o->length + len > o->maxlen) {
1355 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1356 o->data = xrealloc(o->data, 1 + o->maxlen);
1360 static void o_addchr(o_string *o, int ch)
1362 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1364 o->data[o->length] = ch;
1366 o->data[o->length] = '\0';
1369 static void o_addstr(o_string *o, const char *str, int len)
1372 memcpy(&o->data[o->length], str, len);
1374 o->data[o->length] = '\0';
1377 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1382 && (*str != '*' && *str != '?' && *str != '[')
1390 /* My analysis of quoting semantics tells me that state information
1391 * is associated with a destination, not a source.
1393 static void o_addqchr(o_string *o, int ch)
1396 char *found = strchr("*?[\\", ch);
1401 o->data[o->length] = '\\';
1404 o->data[o->length] = ch;
1406 o->data[o->length] = '\0';
1409 static void o_addQchr(o_string *o, int ch)
1412 if (o->o_quote && strchr("*?[\\", ch)) {
1414 o->data[o->length] = '\\';
1418 o->data[o->length] = ch;
1420 o->data[o->length] = '\0';
1423 static void o_addQstr(o_string *o, const char *str, int len)
1426 o_addstr(o, str, len);
1432 int ordinary_cnt = strcspn(str, "*?[\\");
1433 if (ordinary_cnt > len) /* paranoia */
1435 o_addstr(o, str, ordinary_cnt);
1436 if (ordinary_cnt == len)
1438 str += ordinary_cnt;
1439 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1443 if (ch) { /* it is necessarily one of "*?[\\" */
1445 o->data[o->length] = '\\';
1449 o->data[o->length] = ch;
1451 o->data[o->length] = '\0';
1455 /* A special kind of o_string for $VAR and `cmd` expansion.
1456 * It contains char* list[] at the beginning, which is grown in 16 element
1457 * increments. Actual string data starts at the next multiple of 16 * (char*).
1458 * list[i] contains an INDEX (int!) into this string data.
1459 * It means that if list[] needs to grow, data needs to be moved higher up
1460 * but list[i]'s need not be modified.
1461 * NB: remembering how many list[i]'s you have there is crucial.
1462 * o_finalize_list() operation post-processes this structure - calculates
1463 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1465 #if DEBUG_EXPAND || DEBUG_GLOB
1466 static void debug_print_list(const char *prefix, o_string *o, int n)
1468 char **list = (char**)o->data;
1469 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1471 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1472 prefix, list, n, string_start, o->length, o->maxlen);
1474 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1475 o->data + (int)list[i] + string_start,
1476 o->data + (int)list[i] + string_start);
1480 const char *p = o->data + (int)list[n - 1] + string_start;
1481 fprintf(stderr, " total_sz:%ld\n", (p + strlen(p) + 1) - o->data);
1485 #define debug_print_list(prefix, o, n) ((void)0)
1488 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1489 * in list[n] so that it points past last stored byte so far.
1490 * It returns n+1. */
1491 static int o_save_ptr_helper(o_string *o, int n)
1493 char **list = (char**)o->data;
1497 if (!o->has_empty_slot) {
1498 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1499 string_len = o->length - string_start;
1500 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1501 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1502 /* list[n] points to string_start, make space for 16 more pointers */
1503 o->maxlen += 0x10 * sizeof(list[0]);
1504 o->data = xrealloc(o->data, o->maxlen + 1);
1505 list = (char**)o->data;
1506 memmove(list + n + 0x10, list + n, string_len);
1507 o->length += 0x10 * sizeof(list[0]);
1509 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1511 /* We have empty slot at list[n], reuse without growth */
1512 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1513 string_len = o->length - string_start;
1514 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1515 o->has_empty_slot = 0;
1517 list[n] = (char*)(ptrdiff_t)string_len;
1521 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1522 static int o_get_last_ptr(o_string *o, int n)
1524 char **list = (char**)o->data;
1525 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1527 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1530 /* o_glob performs globbing on last list[], saving each result
1531 * as a new list[]. */
1532 static int o_glob(o_string *o, int n)
1538 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1540 return o_save_ptr_helper(o, n);
1541 pattern = o->data + o_get_last_ptr(o, n);
1542 debug_printf_glob("glob pattern '%s'\n", pattern);
1543 if (!glob_needed(pattern)) {
1545 o->length = unbackslash(pattern) - o->data;
1546 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1547 return o_save_ptr_helper(o, n);
1550 memset(&globdata, 0, sizeof(globdata));
1551 gr = glob(pattern, 0, NULL, &globdata);
1552 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1553 if (gr == GLOB_NOSPACE)
1554 bb_error_msg_and_die("out of memory during glob");
1555 if (gr == GLOB_NOMATCH) {
1556 globfree(&globdata);
1559 if (gr != 0) { /* GLOB_ABORTED ? */
1560 //TODO: testcase for bad glob pattern behavior
1561 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1563 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1564 char **argv = globdata.gl_pathv;
1565 o->length = pattern - o->data; /* "forget" pattern */
1567 o_addstr(o, *argv, strlen(*argv) + 1);
1568 n = o_save_ptr_helper(o, n);
1574 globfree(&globdata);
1576 debug_print_list("o_glob returning", o, n);
1580 /* If o->o_glob == 1, glob the string so far remembered.
1581 * Otherwise, just finish current list[] and start new */
1582 static int o_save_ptr(o_string *o, int n)
1584 if (o->o_glob) { /* if globbing is requested */
1585 /* If o->has_empty_slot, list[n] was already globbed
1586 * (if it was requested back then when it was filled)
1587 * so don't do that again! */
1588 if (!o->has_empty_slot)
1589 return o_glob(o, n); /* o_save_ptr_helper is inside */
1591 return o_save_ptr_helper(o, n);
1594 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1595 static char **o_finalize_list(o_string *o, int n)
1600 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1602 debug_print_list("finalized", o, n);
1603 debug_printf_expand("finalized n:%d\n", n);
1604 list = (char**)o->data;
1605 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1609 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1615 /* expand_strvec_to_strvec() takes a list of strings, expands
1616 * all variable references within and returns a pointer to
1617 * a list of expanded strings, possibly with larger number
1618 * of strings. (Think VAR="a b"; echo $VAR).
1619 * This new list is allocated as a single malloc block.
1620 * NULL-terminated list of char* pointers is at the beginning of it,
1621 * followed by strings themself.
1622 * Caller can deallocate entire list by single free(list). */
1624 /* Store given string, finalizing the word and starting new one whenever
1625 * we encounter IFS char(s). This is used for expanding variable values.
1626 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1627 static int expand_on_ifs(o_string *output, int n, const char *str)
1630 int word_len = strcspn(str, G.ifs);
1632 if (output->o_quote || !output->o_glob)
1633 o_addQstr(output, str, word_len);
1634 else /* protect backslashes against globbing up :) */
1635 o_addstr_duplicate_backslash(output, str, word_len);
1638 if (!*str) /* EOL - do not finalize word */
1640 o_addchr(output, '\0');
1641 debug_print_list("expand_on_ifs", output, n);
1642 n = o_save_ptr(output, n);
1643 str += strspn(str, G.ifs); /* skip ifs chars */
1645 debug_print_list("expand_on_ifs[1]", output, n);
1649 #if ENABLE_HUSH_TICK
1650 static int process_command_subs(o_string *dest,
1651 struct in_str *input, const char *subst_end);
1654 /* Expand all variable references in given string, adding words to list[]
1655 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1656 * to be filled). This routine is extremely tricky: has to deal with
1657 * variables/parameters with whitespace, $* and $@, and constructs like
1658 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1659 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1661 /* or_mask is either 0 (normal case) or 0x80
1662 * (expansion of right-hand side of assignment == 1-element expand.
1663 * It will also do no globbing, and thus we must not backslash-quote!) */
1665 char first_ch, ored_ch;
1672 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1673 debug_print_list("expand_vars_to_list", output, n);
1674 n = o_save_ptr(output, n);
1675 debug_print_list("expand_vars_to_list[0]", output, n);
1677 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1678 #if ENABLE_HUSH_TICK
1679 o_string subst_result = NULL_O_STRING;
1681 o_addstr(output, arg, p - arg);
1682 debug_print_list("expand_vars_to_list[1]", output, n);
1684 p = strchr(p, SPECIAL_VAR_SYMBOL);
1686 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1687 /* "$@" is special. Even if quoted, it can still
1688 * expand to nothing (not even an empty string) */
1689 if ((first_ch & 0x7f) != '@')
1690 ored_ch |= first_ch;
1692 switch (first_ch & 0x7f) {
1693 /* Highest bit in first_ch indicates that var is double-quoted */
1695 val = utoa(G.root_pid);
1697 case '!': /* bg pid */
1698 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1700 case '?': /* exitcode */
1701 val = utoa(G.last_return_code);
1703 case '#': /* argc */
1704 if (arg[1] != SPECIAL_VAR_SYMBOL)
1705 /* actually, it's a ${#var} */
1707 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1712 if (!G.global_argv[i])
1714 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1715 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1716 smallint sv = output->o_quote;
1717 /* unquoted var's contents should be globbed, so don't quote */
1718 output->o_quote = 0;
1719 while (G.global_argv[i]) {
1720 n = expand_on_ifs(output, n, G.global_argv[i]);
1721 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1722 if (G.global_argv[i++][0] && G.global_argv[i]) {
1723 /* this argv[] is not empty and not last:
1724 * put terminating NUL, start new word */
1725 o_addchr(output, '\0');
1726 debug_print_list("expand_vars_to_list[2]", output, n);
1727 n = o_save_ptr(output, n);
1728 debug_print_list("expand_vars_to_list[3]", output, n);
1731 output->o_quote = sv;
1733 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1734 * and in this case should treat it like '$*' - see 'else...' below */
1735 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1737 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1738 if (++i >= G.global_argc)
1740 o_addchr(output, '\0');
1741 debug_print_list("expand_vars_to_list[4]", output, n);
1742 n = o_save_ptr(output, n);
1744 } else { /* quoted $*: add as one word */
1746 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1747 if (!G.global_argv[++i])
1750 o_addchr(output, G.ifs[0]);
1754 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1755 /* "Empty variable", used to make "" etc to not disappear */
1759 #if ENABLE_HUSH_TICK
1760 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1761 struct in_str input;
1764 //TODO: can we just stuff it into "output" directly?
1765 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1766 setup_string_in_str(&input, arg);
1767 process_command_subs(&subst_result, &input, NULL);
1768 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1769 val = subst_result.data;
1773 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1775 bool exp_len = false, exp_null = false;
1776 char *var = arg, exp_save, exp_op, *exp_word;
1779 arg[0] = first_ch & 0x7f;
1781 /* prepare for expansions */
1782 if (var[0] == '#') {
1783 /* handle length expansion ${#var} */
1787 /* maybe handle parameter expansion */
1788 exp_off = strcspn(var, ":-=+?");
1792 exp_save = var[exp_off];
1793 exp_null = exp_save == ':';
1794 exp_word = var + exp_off;
1795 if (exp_null) ++exp_word;
1796 exp_op = *exp_word++;
1797 var[exp_off] = '\0';
1801 /* lookup the variable in question */
1802 if (isdigit(var[0])) {
1803 /* handle_dollar() should have vetted var for us */
1805 if (i < G.global_argc)
1806 val = G.global_argv[i];
1807 /* else val remains NULL: $N with too big N */
1809 val = lookup_param(var);
1811 /* handle any expansions */
1813 debug_printf_expand("expand: length of '%s' = ", val);
1814 val = utoa(val ? strlen(val) : 0);
1815 debug_printf_expand("%s\n", val);
1816 } else if (exp_off) {
1817 /* we need to do an expansion */
1818 int exp_test = (!val || (exp_null && !val[0]));
1820 exp_test = !exp_test;
1821 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1822 exp_null ? "true" : "false", exp_test);
1825 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1829 if (exp_op == '=') {
1830 if (isdigit(var[0]) || var[0] == '#') {
1831 maybe_die(var, "special vars cannot assign in this way");
1834 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1835 sprintf(new_var, "%s=%s", var, val);
1836 set_local_var(new_var, -1);
1840 var[exp_off] = exp_save;
1845 #if ENABLE_HUSH_TICK
1848 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1849 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
1851 /* unquoted var's contents should be globbed, so don't quote */
1852 smallint sv = output->o_quote;
1853 output->o_quote = 0;
1854 n = expand_on_ifs(output, n, val);
1856 output->o_quote = sv;
1858 } else { /* quoted $VAR, val will be appended below */
1859 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
1864 o_addQstr(output, val, strlen(val));
1866 /* Do the check to avoid writing to a const string */
1867 if (p && *p != SPECIAL_VAR_SYMBOL)
1868 *p = SPECIAL_VAR_SYMBOL;
1870 #if ENABLE_HUSH_TICK
1871 o_free(&subst_result);
1874 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1877 debug_print_list("expand_vars_to_list[a]", output, n);
1878 /* this part is literal, and it was already pre-quoted
1879 * if needed (much earlier), do not use o_addQstr here! */
1880 o_addstr(output, arg, strlen(arg) + 1);
1881 debug_print_list("expand_vars_to_list[b]", output, n);
1882 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1883 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1886 /* allow to reuse list[n] later without re-growth */
1887 output->has_empty_slot = 1;
1889 o_addchr(output, '\0');
1894 static char **expand_variables(char **argv, int or_mask)
1899 o_string output = NULL_O_STRING;
1901 if (or_mask & 0x100) {
1902 output.o_quote = 1; /* protect against globbing for "$var" */
1903 /* (unquoted $var will temporarily switch it off) */
1910 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1913 debug_print_list("expand_variables", &output, n);
1915 /* output.data (malloced in one block) gets returned in "list" */
1916 list = o_finalize_list(&output, n);
1917 debug_print_strings("expand_variables[1]", list);
1921 static char **expand_strvec_to_strvec(char **argv)
1923 return expand_variables(argv, 0x100);
1926 /* Used for expansion of right hand of assignments */
1927 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1929 static char *expand_string_to_string(const char *str)
1931 char *argv[2], **list;
1933 argv[0] = (char*)str;
1935 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1937 if (!list[0] || list[1])
1938 bb_error_msg_and_die("BUG in varexp2");
1939 /* actually, just move string 2*sizeof(char*) bytes back */
1940 overlapping_strcpy((char*)list, list[0]);
1941 debug_printf_expand("string_to_string='%s'\n", (char*)list);
1945 /* Used for "eval" builtin */
1946 static char* expand_strvec_to_string(char **argv)
1950 list = expand_variables(argv, 0x80);
1951 /* Convert all NULs to spaces */
1956 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
1957 bb_error_msg_and_die("BUG in varexp3");
1958 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
1962 overlapping_strcpy((char*)list, list[0]);
1963 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
1967 static char **expand_assignments(char **argv, int count)
1971 /* Expand assignments into one string each */
1972 for (i = 0; i < count; i++) {
1973 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
1979 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1980 * and stderr if they are redirected. */
1981 static int setup_redirects(struct command *prog, int squirrel[])
1984 struct redir_struct *redir;
1986 for (redir = prog->redirects; redir; redir = redir->next) {
1987 if (redir->dup == -1 && redir->rd_filename == NULL) {
1988 /* something went wrong in the parse. Pretend it didn't happen */
1991 if (redir->dup == -1) {
1993 mode = redir_table[redir->rd_type].mode;
1994 //TODO: check redir for names like '\\'
1995 p = expand_string_to_string(redir->rd_filename);
1996 openfd = open_or_warn(p, mode);
1999 /* this could get lost if stderr has been redirected, but
2000 bash and ash both lose it as well (though zsh doesn't!) */
2004 openfd = redir->dup;
2007 if (openfd != redir->fd) {
2008 if (squirrel && redir->fd < 3) {
2009 squirrel[redir->fd] = dup(redir->fd);
2012 //close(openfd); // close(-3) ??!
2014 dup2(openfd, redir->fd);
2015 if (redir->dup == -1)
2023 static void restore_redirects(int squirrel[])
2026 for (i = 0; i < 3; i++) {
2029 /* We simply die on error */
2036 #if !defined(DEBUG_CLEAN)
2037 #define free_pipe_list(head, indent) free_pipe_list(head)
2038 #define free_pipe(pi, indent) free_pipe(pi)
2040 static int free_pipe_list(struct pipe *head, int indent);
2042 /* return code is the exit status of the pipe */
2043 static int free_pipe(struct pipe *pi, int indent)
2046 struct command *command;
2047 struct redir_struct *r, *rnext;
2048 int a, i, ret_code = 0;
2050 if (pi->stopped_cmds > 0)
2052 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2053 for (i = 0; i < pi->num_cmds; i++) {
2054 command = &pi->cmds[i];
2055 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2056 if (command->argv) {
2057 for (a = 0, p = command->argv; *p; a++, p++) {
2058 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2060 free_strings(command->argv);
2061 command->argv = NULL;
2062 } else if (command->group) {
2063 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2064 ret_code = free_pipe_list(command->group, indent+3);
2065 debug_printf_clean("%s end group\n", indenter(indent));
2067 debug_printf_clean("%s (nil)\n", indenter(indent));
2069 for (r = command->redirects; r; r = rnext) {
2070 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2072 /* guard against the case >$FOO, where foo is unset or blank */
2073 if (r->rd_filename) {
2074 debug_printf_clean(" %s\n", r->rd_filename);
2075 free(r->rd_filename);
2076 r->rd_filename = NULL;
2079 debug_printf_clean("&%d\n", r->dup);
2084 command->redirects = NULL;
2086 free(pi->cmds); /* children are an array, they get freed all at once */
2095 static int free_pipe_list(struct pipe *head, int indent)
2097 int rcode = 0; /* if list has no members */
2098 struct pipe *pi, *next;
2100 for (pi = head; pi; pi = next) {
2102 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2104 rcode = free_pipe(pi, indent);
2105 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2107 /*pi->next = NULL;*/
2115 typedef struct nommu_save_t {
2121 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2122 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2123 #define pseudo_exec(nommu_save, command, argv_expanded) \
2124 pseudo_exec(command, argv_expanded)
2127 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2129 * XXX no exit() here. If you don't exec, use _exit instead.
2130 * The at_exit handlers apparently confuse the calling process,
2131 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2132 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2133 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2137 const struct built_in_command *x;
2139 /* If a variable is assigned in a forest, and nobody listens,
2140 * was it ever really set?
2142 if (!argv[assignment_cnt])
2143 _exit(EXIT_SUCCESS);
2145 new_env = expand_assignments(argv, assignment_cnt);
2147 putenv_all(new_env);
2148 free(new_env); /* optional */
2150 nommu_save->new_env = new_env;
2151 nommu_save->old_env = putenv_all_and_save_old(new_env);
2153 if (argv_expanded) {
2154 argv = argv_expanded;
2156 argv = expand_strvec_to_strvec(argv);
2158 nommu_save->argv = argv;
2163 * Check if the command matches any of the builtins.
2164 * Depending on context, this might be redundant. But it's
2165 * easier to waste a few CPU cycles than it is to figure out
2166 * if this is one of those cases.
2168 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2169 if (strcmp(argv[0], x->cmd) == 0) {
2170 debug_printf_exec("running builtin '%s'\n", argv[0]);
2171 rcode = x->function(argv);
2177 /* Check if the command matches any busybox applets */
2178 #if ENABLE_FEATURE_SH_STANDALONE
2179 if (strchr(argv[0], '/') == NULL) {
2180 int a = find_applet_by_name(argv[0]);
2182 if (APPLET_IS_NOEXEC(a)) {
2183 debug_printf_exec("running applet '%s'\n", argv[0]);
2184 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2185 run_applet_no_and_exit(a, argv);
2187 /* re-exec ourselves with the new arguments */
2188 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2189 execvp(bb_busybox_exec_path, argv);
2190 /* If they called chroot or otherwise made the binary no longer
2191 * executable, fall through */
2196 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2198 debug_printf_exec("execing '%s'\n", argv[0]);
2199 execvp(argv[0], argv);
2200 bb_perror_msg("can't exec '%s'", argv[0]);
2201 _exit(EXIT_FAILURE);
2204 static int run_list(struct pipe *pi);
2206 /* Called after [v]fork() in run_pipe()
2208 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2209 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2212 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2214 if (command->group) {
2216 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2219 debug_printf_exec("pseudo_exec: run_list\n");
2220 rcode = run_list(command->group);
2221 /* OK to leak memory by not calling free_pipe_list,
2222 * since this process is about to exit */
2227 /* Can happen. See what bash does with ">foo" by itself. */
2228 debug_printf("trying to pseudo_exec null command\n");
2229 _exit(EXIT_SUCCESS);
2233 static const char *get_cmdtext(struct pipe *pi)
2239 /* This is subtle. ->cmdtext is created only on first backgrounding.
2240 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2241 * On subsequent bg argv is trashed, but we won't use it */
2244 argv = pi->cmds[0].argv;
2245 if (!argv || !argv[0]) {
2246 pi->cmdtext = xzalloc(1);
2251 do len += strlen(*argv) + 1; while (*++argv);
2252 pi->cmdtext = p = xmalloc(len);
2253 argv = pi->cmds[0].argv;
2255 len = strlen(*argv);
2256 memcpy(p, *argv, len);
2264 static void insert_bg_job(struct pipe *pi)
2266 struct pipe *thejob;
2269 /* Linear search for the ID of the job to use */
2271 for (thejob = G.job_list; thejob; thejob = thejob->next)
2272 if (thejob->jobid >= pi->jobid)
2273 pi->jobid = thejob->jobid + 1;
2275 /* Add thejob to the list of running jobs */
2277 thejob = G.job_list = xmalloc(sizeof(*thejob));
2279 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2281 thejob->next = xmalloc(sizeof(*thejob));
2282 thejob = thejob->next;
2285 /* Physically copy the struct job */
2286 memcpy(thejob, pi, sizeof(struct pipe));
2287 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2288 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2289 for (i = 0; i < pi->num_cmds; i++) {
2290 // TODO: do we really need to have so many fields which are just dead weight
2291 // at execution stage?
2292 thejob->cmds[i].pid = pi->cmds[i].pid;
2293 /* all other fields are not used and stay zero */
2295 thejob->next = NULL;
2296 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2298 /* We don't wait for background thejobs to return -- append it
2299 to the list of backgrounded thejobs and leave it alone */
2300 if (G.interactive_fd)
2301 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2302 G.last_bg_pid = thejob->cmds[0].pid;
2303 G.last_jobid = thejob->jobid;
2306 static void remove_bg_job(struct pipe *pi)
2308 struct pipe *prev_pipe;
2310 if (pi == G.job_list) {
2311 G.job_list = pi->next;
2313 prev_pipe = G.job_list;
2314 while (prev_pipe->next != pi)
2315 prev_pipe = prev_pipe->next;
2316 prev_pipe->next = pi->next;
2319 G.last_jobid = G.job_list->jobid;
2324 /* Remove a backgrounded job */
2325 static void delete_finished_bg_job(struct pipe *pi)
2328 pi->stopped_cmds = 0;
2334 /* Check to see if any processes have exited -- if they
2335 * have, figure out why and see if a job has completed */
2336 static int checkjobs(struct pipe* fg_pipe)
2346 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2349 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2350 // /* avoid doing syscall, nothing there anyway */
2353 attributes = WUNTRACED;
2354 if (fg_pipe == NULL)
2355 attributes |= WNOHANG;
2357 /* Do we do this right?
2358 * bash-3.00# sleep 20 | false
2360 * [3]+ Stopped sleep 20 | false
2361 * bash-3.00# echo $?
2362 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2365 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2366 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2367 // + killall -STOP cat
2374 // i = G.count_SIGCHLD;
2375 childpid = waitpid(-1, &status, attributes);
2376 if (childpid <= 0) {
2377 if (childpid && errno != ECHILD)
2378 bb_perror_msg("waitpid");
2379 // else /* Until next SIGCHLD, waitpid's are useless */
2380 // G.handled_SIGCHLD = i;
2383 dead = WIFEXITED(status) || WIFSIGNALED(status);
2386 if (WIFSTOPPED(status))
2387 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2388 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2389 if (WIFSIGNALED(status))
2390 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2391 childpid, WTERMSIG(status), WEXITSTATUS(status));
2392 if (WIFEXITED(status))
2393 debug_printf_jobs("pid %d exited, exitcode %d\n",
2394 childpid, WEXITSTATUS(status));
2396 /* Were we asked to wait for fg pipe? */
2398 for (i = 0; i < fg_pipe->num_cmds; i++) {
2399 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2400 if (fg_pipe->cmds[i].pid != childpid)
2402 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2404 fg_pipe->cmds[i].pid = 0;
2405 fg_pipe->alive_cmds--;
2406 if (i == fg_pipe->num_cmds - 1) {
2407 /* last process gives overall exitstatus */
2408 rcode = WEXITSTATUS(status);
2409 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2412 fg_pipe->cmds[i].is_stopped = 1;
2413 fg_pipe->stopped_cmds++;
2415 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2416 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2417 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2418 /* All processes in fg pipe have exited/stopped */
2420 if (fg_pipe->alive_cmds)
2421 insert_bg_job(fg_pipe);
2425 /* There are still running processes in the fg pipe */
2426 goto wait_more; /* do waitpid again */
2428 /* it wasnt fg_pipe, look for process in bg pipes */
2432 /* We asked to wait for bg or orphaned children */
2433 /* No need to remember exitcode in this case */
2434 for (pi = G.job_list; pi; pi = pi->next) {
2435 for (i = 0; i < pi->num_cmds; i++) {
2436 if (pi->cmds[i].pid == childpid)
2437 goto found_pi_and_prognum;
2440 /* Happens when shell is used as init process (init=/bin/sh) */
2441 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2442 continue; /* do waitpid again */
2444 found_pi_and_prognum:
2447 pi->cmds[i].pid = 0;
2449 if (!pi->alive_cmds) {
2450 if (G.interactive_fd)
2451 printf(JOB_STATUS_FORMAT, pi->jobid,
2452 "Done", pi->cmdtext);
2453 delete_finished_bg_job(pi);
2457 pi->cmds[i].is_stopped = 1;
2461 } /* while (waitpid succeeds)... */
2467 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2470 int rcode = checkjobs(fg_pipe);
2471 /* Job finished, move the shell to the foreground */
2472 p = getpgid(0); /* pgid of our process */
2473 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2474 tcsetpgrp(G.interactive_fd, p);
2479 /* run_pipe() starts all the jobs, but doesn't wait for anything
2480 * to finish. See checkjobs().
2482 * return code is normally -1, when the caller has to wait for children
2483 * to finish to determine the exit status of the pipe. If the pipe
2484 * is a simple builtin command, however, the action is done by the
2485 * time run_pipe returns, and the exit code is provided as the
2488 * The input of the pipe is always stdin, the output is always
2489 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2490 * because it tries to avoid running the command substitution in
2491 * subshell, when that is in fact necessary. The subshell process
2492 * now has its stdout directed to the input of the appropriate pipe,
2493 * so this routine is noticeably simpler.
2495 * Returns -1 only if started some children. IOW: we have to
2496 * mask out retvals of builtins etc with 0xff!
2498 static int run_pipe(struct pipe *pi)
2502 int pipefds[2]; /* pipefds[0] is for reading */
2503 struct command *command;
2504 char **argv_expanded;
2506 const struct built_in_command *x;
2508 /* it is not always needed, but we aim to smaller code */
2509 int squirrel[] = { -1, -1, -1 };
2511 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2513 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2519 pi->stopped_cmds = 0;
2521 /* Check if this is a simple builtin (not part of a pipe).
2522 * Builtins within pipes have to fork anyway, and are handled in
2523 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2525 command = &(pi->cmds[0]);
2527 #if ENABLE_HUSH_FUNCTIONS
2528 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2529 /* We "execute" function definition */
2530 bb_error_msg("here we ought to remember function definition, and go on");
2531 return EXIT_SUCCESS;
2535 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2536 debug_printf("non-subshell grouping\n");
2537 setup_redirects(command, squirrel);
2538 debug_printf_exec(": run_list\n");
2539 rcode = run_list(command->group) & 0xff;
2540 restore_redirects(squirrel);
2541 debug_printf_exec("run_pipe return %d\n", rcode);
2542 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2546 argv = command->argv;
2547 argv_expanded = NULL;
2549 if (single_and_fg && argv != NULL) {
2550 char **new_env = NULL;
2551 char **old_env = NULL;
2553 i = command->assignment_cnt;
2554 if (i != 0 && argv[i] == NULL) {
2555 /* assignments, but no command: set local environment */
2556 for (i = 0; argv[i] != NULL; i++) {
2557 debug_printf("local environment set: %s\n", argv[i]);
2558 p = expand_string_to_string(argv[i]);
2559 set_local_var(p, 0);
2561 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2564 /* Expand the rest into (possibly) many strings each */
2565 argv_expanded = expand_strvec_to_strvec(argv + i);
2567 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2568 if (strcmp(argv_expanded[0], x->cmd) != 0)
2570 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2571 debug_printf("exec with redirects only\n");
2572 setup_redirects(command, NULL);
2573 rcode = EXIT_SUCCESS;
2574 goto clean_up_and_ret1;
2576 debug_printf("builtin inline %s\n", argv_expanded[0]);
2577 /* XXX setup_redirects acts on file descriptors, not FILEs.
2578 * This is perfect for work that comes after exec().
2579 * Is it really safe for inline use? Experimentally,
2580 * things seem to work with glibc. */
2581 setup_redirects(command, squirrel);
2582 new_env = expand_assignments(argv, command->assignment_cnt);
2583 old_env = putenv_all_and_save_old(new_env);
2584 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2585 rcode = x->function(argv_expanded) & 0xff;
2586 #if ENABLE_FEATURE_SH_STANDALONE
2589 restore_redirects(squirrel);
2590 free_strings_and_unsetenv(new_env, 1);
2591 putenv_all(old_env);
2592 free(old_env); /* not free_strings()! */
2594 free(argv_expanded);
2595 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2596 debug_printf_exec("run_pipe return %d\n", rcode);
2599 #if ENABLE_FEATURE_SH_STANDALONE
2600 i = find_applet_by_name(argv_expanded[0]);
2601 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2602 setup_redirects(command, squirrel);
2603 save_nofork_data(&G.nofork_save);
2604 new_env = expand_assignments(argv, command->assignment_cnt);
2605 old_env = putenv_all_and_save_old(new_env);
2606 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2607 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2608 goto clean_up_and_ret;
2613 /* NB: argv_expanded may already be created, and that
2614 * might include `cmd` runs! Do not rerun it! We *must*
2615 * use argv_expanded if it's non-NULL */
2617 /* Going to fork a child per each pipe member */
2621 for (i = 0; i < pi->num_cmds; i++) {
2623 volatile nommu_save_t nommu_save;
2624 nommu_save.new_env = NULL;
2625 nommu_save.old_env = NULL;
2626 nommu_save.argv = NULL;
2628 command = &(pi->cmds[i]);
2629 if (command->argv) {
2630 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2632 debug_printf_exec(": pipe member with no argv\n");
2634 /* pipes are inserted between pairs of commands */
2637 if ((i + 1) < pi->num_cmds)
2640 command->pid = BB_MMU ? fork() : vfork();
2641 if (!command->pid) { /* child */
2643 die_sleep = 0; /* let nofork's xfuncs die */
2645 /* Every child adds itself to new process group
2646 * with pgid == pid_of_first_child_in_pipe */
2647 if (G.run_list_level == 1 && G.interactive_fd) {
2650 if (pgrp < 0) /* true for 1st process only */
2652 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2653 /* We do it in *every* child, not just first,
2655 tcsetpgrp(G.interactive_fd, pgrp);
2659 xmove_fd(nextin, 0);
2660 xmove_fd(pipefds[1], 1); /* write end */
2662 close(pipefds[0]); /* read end */
2663 /* Like bash, explicit redirects override pipes,
2664 * and the pipe fd is available for dup'ing. */
2665 setup_redirects(command, NULL);
2667 /* Restore default handlers just prior to exec */
2668 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2670 /* Stores to nommu_save list of env vars putenv'ed
2671 * (NOMMU, on MMU we don't need that) */
2672 /* cast away volatility... */
2673 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2674 /* pseudo_exec() does not return */
2678 /* Clean up after vforked child */
2679 free(nommu_save.argv);
2680 free_strings_and_unsetenv(nommu_save.new_env, 1);
2681 putenv_all(nommu_save.old_env);
2683 free(argv_expanded);
2684 argv_expanded = NULL;
2685 if (command->pid < 0) { /* [v]fork failed */
2686 /* Clearly indicate, was it fork or vfork */
2687 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2691 /* Second and next children need to know pid of first one */
2693 pi->pgrp = command->pid;
2699 if ((i + 1) < pi->num_cmds)
2700 close(pipefds[1]); /* write end */
2701 /* Pass read (output) pipe end to next iteration */
2702 nextin = pipefds[0];
2705 if (!pi->alive_cmds) {
2706 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2710 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2714 #ifndef debug_print_tree
2715 static void debug_print_tree(struct pipe *pi, int lvl)
2717 static const char *const PIPE[] = {
2723 static const char *RES[] = {
2724 [RES_NONE ] = "NONE" ,
2727 [RES_THEN ] = "THEN" ,
2728 [RES_ELIF ] = "ELIF" ,
2729 [RES_ELSE ] = "ELSE" ,
2732 #if ENABLE_HUSH_LOOPS
2733 [RES_FOR ] = "FOR" ,
2734 [RES_WHILE] = "WHILE",
2735 [RES_UNTIL] = "UNTIL",
2737 [RES_DONE ] = "DONE" ,
2739 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2742 #if ENABLE_HUSH_CASE
2743 [RES_CASE ] = "CASE" ,
2744 [RES_MATCH] = "MATCH",
2745 [RES_CASEI] = "CASEI",
2746 [RES_ESAC ] = "ESAC" ,
2748 [RES_XXXX ] = "XXXX" ,
2749 [RES_SNTX ] = "SNTX" ,
2751 static const char *const GRPTYPE[] = {
2754 #if ENABLE_HUSH_FUNCTIONS
2763 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2764 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2766 while (prn < pi->num_cmds) {
2767 struct command *command = &pi->cmds[prn];
2768 char **argv = command->argv;
2770 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2771 if (command->group) {
2772 fprintf(stderr, " group %s: (argv=%p)\n",
2773 GRPTYPE[command->grp_type],
2775 debug_print_tree(command->group, lvl+1);
2779 if (argv) while (*argv) {
2780 fprintf(stderr, " '%s'", *argv);
2783 fprintf(stderr, "\n");
2792 /* NB: called by pseudo_exec, and therefore must not modify any
2793 * global data until exec/_exit (we can be a child after vfork!) */
2794 static int run_list(struct pipe *pi)
2796 #if ENABLE_HUSH_CASE
2797 char *case_word = NULL;
2799 #if ENABLE_HUSH_LOOPS
2800 struct pipe *loop_top = NULL;
2801 char *for_varname = NULL;
2802 char **for_lcur = NULL;
2803 char **for_list = NULL;
2805 smallint flag_skip = 1;
2806 smalluint rcode = 0; /* probably just for compiler */
2807 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2808 smalluint cond_code = 0;
2810 enum { cond_code = 0, };
2812 /*enum reserved_style*/ smallint rword = RES_NONE;
2813 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2815 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2817 #if ENABLE_HUSH_LOOPS
2818 /* Check syntax for "for" */
2819 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2820 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2822 /* current word is FOR or IN (BOLD in comments below) */
2823 if (cpipe->next == NULL) {
2824 syntax("malformed for");
2825 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2828 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2829 if (cpipe->next->res_word == RES_DO)
2831 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2832 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2833 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2835 syntax("malformed for");
2836 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2842 /* Past this point, all code paths should jump to ret: label
2843 * in order to return, no direct "return" statements please.
2844 * This helps to ensure that no memory is leaked. */
2846 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2849 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2850 * We are saving state before entering outermost list ("while...done")
2851 * so that ctrl-Z will correctly background _entire_ outermost list,
2852 * not just a part of it (like "sleep 1 | exit 2") */
2853 if (++G.run_list_level == 1 && G.interactive_fd) {
2854 if (sigsetjmp(G.toplevel_jb, 1)) {
2855 /* ctrl-Z forked and we are parent; or ctrl-C.
2856 * Sighandler has longjmped us here */
2857 signal(SIGINT, SIG_IGN);
2858 signal(SIGTSTP, SIG_IGN);
2859 /* Restore level (we can be coming from deep inside
2861 G.run_list_level = 1;
2862 #if ENABLE_FEATURE_SH_STANDALONE
2863 if (G.nofork_save.saved) { /* if save area is valid */
2864 debug_printf_jobs("exiting nofork early\n");
2865 restore_nofork_data(&G.nofork_save);
2868 //// if (G.ctrl_z_flag) {
2869 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2870 //// * Remember this child as background job */
2871 //// insert_bg_job(pi);
2873 /* ctrl-C. We just stop doing whatever we were doing */
2876 USE_HUSH_LOOPS(loop_top = NULL;)
2877 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2881 //// /* ctrl-Z handler will store pid etc in pi */
2882 //// G.toplevel_list = pi;
2883 //// G.ctrl_z_flag = 0;
2884 ////#if ENABLE_FEATURE_SH_STANDALONE
2885 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2887 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2888 //// signal(SIGINT, handler_ctrl_c);
2892 /* Go through list of pipes, (maybe) executing them. */
2893 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2897 IF_HAS_KEYWORDS(rword = pi->res_word;)
2898 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2899 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2900 rword, cond_code, skip_more_for_this_rword);
2901 #if ENABLE_HUSH_LOOPS
2902 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2903 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2905 /* start of a loop: remember where loop starts */
2910 if (rword == skip_more_for_this_rword && flag_skip) {
2911 if (pi->followup == PIPE_SEQ)
2913 /* it is "<false> && CMD" or "<true> || CMD"
2914 * and we should not execute CMD */
2918 skip_more_for_this_rword = RES_XXXX;
2921 if (rword == RES_THEN) {
2922 /* "if <false> THEN cmd": skip cmd */
2926 if (rword == RES_ELSE || rword == RES_ELIF) {
2927 /* "if <true> then ... ELSE/ELIF cmd":
2928 * skip cmd and all following ones */
2933 #if ENABLE_HUSH_LOOPS
2934 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
2936 /* first loop through for */
2938 static const char encoded_dollar_at[] ALIGN1 = {
2939 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
2940 }; /* encoded representation of "$@" */
2941 static const char *const encoded_dollar_at_argv[] = {
2942 encoded_dollar_at, NULL
2943 }; /* argv list with one element: "$@" */
2946 vals = (char**)encoded_dollar_at_argv;
2947 if (pi->next->res_word == RES_IN) {
2948 /* if no variable values after "in" we skip "for" */
2949 if (!pi->next->cmds[0].argv)
2951 vals = pi->next->cmds[0].argv;
2952 } /* else: "for var; do..." -> assume "$@" list */
2953 /* create list of variable values */
2954 debug_print_strings("for_list made from", vals);
2955 for_list = expand_strvec_to_strvec(vals);
2956 for_lcur = for_list;
2957 debug_print_strings("for_list", for_list);
2958 for_varname = pi->cmds[0].argv[0];
2959 pi->cmds[0].argv[0] = NULL;
2961 free(pi->cmds[0].argv[0]);
2963 /* "for" loop is over, clean up */
2967 pi->cmds[0].argv[0] = for_varname;
2970 /* insert next value from for_lcur */
2971 //TODO: does it need escaping?
2972 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2973 pi->cmds[0].assignment_cnt = 1;
2975 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
2977 if (rword == RES_DONE) {
2978 continue; /* "done" has no cmds too */
2981 #if ENABLE_HUSH_CASE
2982 if (rword == RES_CASE) {
2983 case_word = expand_strvec_to_string(pi->cmds->argv);
2986 if (rword == RES_MATCH) {
2989 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
2991 /* all prev words didn't match, does this one match? */
2992 argv = pi->cmds->argv;
2994 char *pattern = expand_string_to_string(*argv);
2995 /* TODO: which FNM_xxx flags to use? */
2996 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
2998 if (cond_code == 0) { /* match! we will execute this branch */
2999 free(case_word); /* make future "word)" stop */
3007 if (rword == RES_CASEI) { /* inside of a case branch */
3009 continue; /* not matched yet, skip this pipe */
3012 /* Just pressing <enter> in shell should check for jobs.
3013 * OTOH, in non-interactive shell this is useless
3014 * and only leads to extra job checks */
3015 if (pi->num_cmds == 0) {
3016 if (G.interactive_fd)
3017 goto check_jobs_and_continue;
3021 /* After analyzing all keywords and conditions, we decided
3022 * to execute this pipe. NB: have to do checkjobs(NULL)
3023 * after run_pipe() to collect any background children,
3024 * even if list execution is to be stopped. */
3025 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3028 #if ENABLE_HUSH_LOOPS
3029 G.flag_break_continue = 0;
3031 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3033 /* we only ran a builtin: rcode is already known
3034 * and we don't need to wait for anything. */
3035 check_and_run_traps(0);
3036 #if ENABLE_HUSH_LOOPS
3037 /* was it "break" or "continue"? */
3038 if (G.flag_break_continue) {
3039 smallint fbc = G.flag_break_continue;
3040 /* we might fall into outer *loop*,
3041 * don't want to break it too */
3043 G.depth_break_continue--;
3044 if (G.depth_break_continue == 0)
3045 G.flag_break_continue = 0;
3046 /* else: e.g. "continue 2" should *break* once, *then* continue */
3047 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3048 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3049 goto check_jobs_and_break;
3050 /* "continue": simulate end of loop */
3055 } else if (pi->followup == PIPE_BG) {
3056 /* what does bash do with attempts to background builtins? */
3057 /* even bash 3.2 doesn't do that well with nested bg:
3058 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3059 * I'm NOT treating inner &'s as jobs */
3060 check_and_run_traps(0);
3062 if (G.run_list_level == 1)
3065 rcode = 0; /* EXIT_SUCCESS */
3068 if (G.run_list_level == 1 && G.interactive_fd) {
3069 /* waits for completion, then fg's main shell */
3070 rcode = checkjobs_and_fg_shell(pi);
3071 check_and_run_traps(0);
3072 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3075 { /* this one just waits for completion */
3076 rcode = checkjobs(pi);
3077 check_and_run_traps(0);
3078 debug_printf_exec(": checkjobs returned %d\n", rcode);
3082 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3083 G.last_return_code = rcode;
3085 /* Analyze how result affects subsequent commands */
3087 if (rword == RES_IF || rword == RES_ELIF)
3090 #if ENABLE_HUSH_LOOPS
3091 if (rword == RES_WHILE) {
3093 rcode = 0; /* "while false; do...done" - exitcode 0 */
3094 goto check_jobs_and_break;
3097 if (rword == RES_UNTIL) {
3099 check_jobs_and_break:
3105 if ((rcode == 0 && pi->followup == PIPE_OR)
3106 || (rcode != 0 && pi->followup == PIPE_AND)
3108 skip_more_for_this_rword = rword;
3111 check_jobs_and_continue:
3116 //// if (G.ctrl_z_flag) {
3117 //// /* ctrl-Z forked somewhere in the past, we are the child,
3118 //// * and now we completed running the list. Exit. */
3124 //// if (!G.run_list_level && G.interactive_fd) {
3125 //// signal(SIGTSTP, SIG_IGN);
3126 //// signal(SIGINT, SIG_IGN);
3129 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3130 #if ENABLE_HUSH_LOOPS
3135 #if ENABLE_HUSH_CASE
3141 /* Select which version we will use */
3142 static int run_and_free_list(struct pipe *pi)
3145 debug_printf_exec("run_and_free_list entered\n");
3147 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3148 rcode = run_list(pi);
3150 /* free_pipe_list has the side effect of clearing memory.
3151 * In the long run that function can be merged with run_list,
3152 * but doing that now would hobble the debugging effort. */
3153 free_pipe_list(pi, /* indent: */ 0);
3154 debug_printf_exec("run_and_free_list return %d\n", rcode);
3159 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3160 * as in "2>&1", that represents duplicating a file descriptor.
3161 * Return either -2 (syntax error), -1 (no &), or the number found.
3163 static int redirect_dup_num(struct in_str *input)
3165 int ch, d = 0, ok = 0;
3167 if (ch != '&') return -1;
3169 i_getch(input); /* get the & */
3173 return -3; /* "-" represents "close me" */
3175 while (isdigit(ch)) {
3176 d = d*10 + (ch-'0');
3183 bb_error_msg("ambiguous redirect");
3187 /* The src parameter allows us to peek forward to a possible &n syntax
3188 * for file descriptor duplication, e.g., "2>&1".
3189 * Return code is 0 normally, 1 if a syntax error is detected in src.
3190 * Resource errors (in xmalloc) cause the process to exit */
3191 static int setup_redirect(struct parse_context *ctx, int fd, redir_type style,
3192 struct in_str *input)
3194 struct command *command = ctx->command;
3195 struct redir_struct *redir = command->redirects;
3196 struct redir_struct *last_redir = NULL;
3198 /* Create a new redir_struct and drop it onto the end of the linked list */
3201 redir = redir->next;
3203 redir = xzalloc(sizeof(struct redir_struct));
3204 /* redir->next = NULL; */
3205 /* redir->rd_filename = NULL; */
3207 last_redir->next = redir;
3209 command->redirects = redir;
3212 redir->rd_type = style;
3213 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3215 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3217 /* Check for a '2>&1' type redirect */
3218 redir->dup = redirect_dup_num(input);
3219 if (redir->dup == -2)
3220 return 1; /* syntax error */
3221 if (redir->dup != -1) {
3222 /* Erik had a check here that the file descriptor in question
3223 * is legit; I postpone that to "run time"
3224 * A "-" representation of "close me" shows up as a -3 here */
3225 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3227 /* We do _not_ try to open the file that src points to,
3228 * since we need to return and let src be expanded first.
3229 * Set ctx->pending_redirect, so we know what to do at the
3230 * end of the next parsed word. */
3231 ctx->pending_redirect = redir;
3237 static struct pipe *new_pipe(void)
3240 pi = xzalloc(sizeof(struct pipe));
3241 /*pi->followup = 0; - deliberately invalid value */
3242 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3246 /* Command (member of a pipe) is complete. The only possible error here
3247 * is out of memory, in which case xmalloc exits. */
3248 static int done_command(struct parse_context *ctx)
3250 /* The command is really already in the pipe structure, so
3251 * advance the pipe counter and make a new, null command. */
3252 struct pipe *pi = ctx->pipe;
3253 struct command *command = ctx->command;
3256 if (command->group == NULL
3257 && command->argv == NULL
3258 && command->redirects == NULL
3260 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3261 return pi->num_cmds;
3264 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3266 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3269 /* Only real trickiness here is that the uncommitted
3270 * command structure is not counted in pi->num_cmds. */
3271 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3272 command = &pi->cmds[pi->num_cmds];
3273 memset(command, 0, sizeof(*command));
3275 ctx->command = command;
3276 /* but ctx->pipe and ctx->list_head remain unchanged */
3278 return pi->num_cmds; /* used only for 0/nonzero check */
3281 static void done_pipe(struct parse_context *ctx, pipe_style type)
3285 debug_printf_parse("done_pipe entered, followup %d\n", type);
3286 /* Close previous command */
3287 not_null = done_command(ctx);
3288 ctx->pipe->followup = type;
3289 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3290 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3291 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3293 /* Without this check, even just <enter> on command line generates
3294 * tree of three NOPs (!). Which is harmless but annoying.
3295 * IOW: it is safe to do it unconditionally.
3296 * RES_NONE case is for "for a in; do ..." (empty IN set)
3297 * to work, possibly other cases too. */
3298 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3300 debug_printf_parse("done_pipe: adding new pipe: "
3301 "not_null:%d ctx->ctx_res_w:%d\n",
3302 not_null, ctx->ctx_res_w);
3304 ctx->pipe->next = new_p;
3306 ctx->command = NULL; /* needed! */
3307 /* RES_THEN, RES_DO etc are "sticky" -
3308 * they remain set for commands inside if/while.
3309 * This is used to control execution.
3310 * RES_FOR and RES_IN are NOT sticky (needed to support
3311 * cases where variable or value happens to match a keyword):
3313 #if ENABLE_HUSH_LOOPS
3314 if (ctx->ctx_res_w == RES_FOR
3315 || ctx->ctx_res_w == RES_IN)
3316 ctx->ctx_res_w = RES_NONE;
3318 #if ENABLE_HUSH_CASE
3319 if (ctx->ctx_res_w == RES_MATCH)
3320 ctx->ctx_res_w = RES_CASEI;
3322 /* Create the memory for command, roughly:
3323 * ctx->pipe->cmds = new struct command;
3324 * ctx->command = &ctx->pipe->cmds[0];
3328 debug_printf_parse("done_pipe return\n");
3331 static void initialize_context(struct parse_context *ctx)
3333 memset(ctx, 0, sizeof(*ctx));
3334 ctx->pipe = ctx->list_head = new_pipe();
3335 /* Create the memory for command, roughly:
3336 * ctx->pipe->cmds = new struct command;
3337 * ctx->command = &ctx->pipe->cmds[0];
3343 /* If a reserved word is found and processed, parse context is modified
3344 * and 1 is returned.
3347 struct reserved_combo {
3350 unsigned char assignment_flag;
3354 FLAG_END = (1 << RES_NONE ),
3356 FLAG_IF = (1 << RES_IF ),
3357 FLAG_THEN = (1 << RES_THEN ),
3358 FLAG_ELIF = (1 << RES_ELIF ),
3359 FLAG_ELSE = (1 << RES_ELSE ),
3360 FLAG_FI = (1 << RES_FI ),
3362 #if ENABLE_HUSH_LOOPS
3363 FLAG_FOR = (1 << RES_FOR ),
3364 FLAG_WHILE = (1 << RES_WHILE),
3365 FLAG_UNTIL = (1 << RES_UNTIL),
3366 FLAG_DO = (1 << RES_DO ),
3367 FLAG_DONE = (1 << RES_DONE ),
3368 FLAG_IN = (1 << RES_IN ),
3370 #if ENABLE_HUSH_CASE
3371 FLAG_MATCH = (1 << RES_MATCH),
3372 FLAG_ESAC = (1 << RES_ESAC ),
3374 FLAG_START = (1 << RES_XXXX ),
3377 static const struct reserved_combo* match_reserved_word(o_string *word)
3379 /* Mostly a list of accepted follow-up reserved words.
3380 * FLAG_END means we are done with the sequence, and are ready
3381 * to turn the compound list into a command.
3382 * FLAG_START means the word must start a new compound list.
3384 static const struct reserved_combo reserved_list[] = {
3386 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3387 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3388 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3389 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3390 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3391 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3393 #if ENABLE_HUSH_LOOPS
3394 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3395 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3396 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3397 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3398 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3399 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3401 #if ENABLE_HUSH_CASE
3402 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3403 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3406 const struct reserved_combo *r;
3408 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3409 if (strcmp(word->data, r->literal) == 0)
3414 static int reserved_word(o_string *word, struct parse_context *ctx)
3416 #if ENABLE_HUSH_CASE
3417 static const struct reserved_combo reserved_match = {
3418 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3421 const struct reserved_combo *r;
3423 r = match_reserved_word(word);
3427 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3428 #if ENABLE_HUSH_CASE
3429 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3430 /* "case word IN ..." - IN part starts first match part */
3431 r = &reserved_match;
3434 if (r->flag == 0) { /* '!' */
3435 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3437 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3439 ctx->ctx_inverted = 1;
3442 if (r->flag & FLAG_START) {
3443 struct parse_context *new;
3444 debug_printf("push stack\n");
3445 new = xmalloc(sizeof(*new));
3446 *new = *ctx; /* physical copy */
3447 initialize_context(ctx);
3449 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3451 ctx->ctx_res_w = RES_SNTX;
3454 ctx->ctx_res_w = r->res;
3455 ctx->old_flag = r->flag;
3456 if (ctx->old_flag & FLAG_END) {
3457 struct parse_context *old;
3458 debug_printf("pop stack\n");
3459 done_pipe(ctx, PIPE_SEQ);
3461 old->command->group = ctx->list_head;
3462 old->command->grp_type = GRP_NORMAL;
3463 *ctx = *old; /* physical copy */
3466 word->o_assignment = r->assignment_flag;
3471 //TODO: many, many callers don't check error from done_word()
3473 /* Word is complete, look at it and update parsing context.
3474 * Normal return is 0. Syntax errors return 1. */
3475 static int done_word(o_string *word, struct parse_context *ctx)
3477 struct command *command = ctx->command;
3479 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3480 if (word->length == 0 && word->nonnull == 0) {
3481 debug_printf_parse("done_word return 0: true null, ignored\n");
3484 /* If this word wasn't an assignment, next ones definitely
3485 * can't be assignments. Even if they look like ones. */
3486 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3487 && word->o_assignment != WORD_IS_KEYWORD
3489 word->o_assignment = NOT_ASSIGNMENT;
3491 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3492 command->assignment_cnt++;
3493 word->o_assignment = MAYBE_ASSIGNMENT;
3496 if (ctx->pending_redirect) {
3497 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3498 * only if run as "bash", not "sh" */
3499 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3500 word->o_assignment = NOT_ASSIGNMENT;
3501 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3503 /* "{ echo foo; } echo bar" - bad */
3504 /* NB: bash allows e.g. "if true; then { echo foo; } fi". TODO? */
3505 if (command->group) {
3507 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
3511 #if ENABLE_HUSH_CASE
3512 if (ctx->ctx_dsemicolon
3513 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3515 /* already done when ctx_dsemicolon was set to 1: */
3516 /* ctx->ctx_res_w = RES_MATCH; */
3517 ctx->ctx_dsemicolon = 0;
3521 if (!command->argv /* if it's the first word... */
3522 #if ENABLE_HUSH_LOOPS
3523 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3524 && ctx->ctx_res_w != RES_IN
3527 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3528 if (reserved_word(word, ctx)) {
3530 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3531 return (ctx->ctx_res_w == RES_SNTX);
3535 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3536 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3537 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3538 /* (otherwise it's known to be not empty and is already safe) */
3540 /* exclude "$@" - it can expand to no word despite "" */
3541 char *p = word->data;
3542 while (p[0] == SPECIAL_VAR_SYMBOL
3543 && (p[1] & 0x7f) == '@'
3544 && p[2] == SPECIAL_VAR_SYMBOL
3548 if (p == word->data || p[0] != '\0') {
3549 /* saw no "$@", or not only "$@" but some
3550 * real text is there too */
3551 /* insert "empty variable" reference, this makes
3552 * e.g. "", $empty"" etc to not disappear */
3553 o_addchr(word, SPECIAL_VAR_SYMBOL);
3554 o_addchr(word, SPECIAL_VAR_SYMBOL);
3557 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3558 debug_print_strings("word appended to argv", command->argv);
3562 ctx->pending_redirect = NULL;
3564 #if ENABLE_HUSH_LOOPS
3565 /* Force FOR to have just one word (variable name) */
3566 /* NB: basically, this makes hush see "for v in ..." syntax as if
3567 * as it is "for v; in ...". FOR and IN become two pipe structs
3569 if (ctx->ctx_res_w == RES_FOR) {
3570 //TODO: check that command->argv[0] is a valid variable name!
3571 done_pipe(ctx, PIPE_SEQ);
3574 #if ENABLE_HUSH_CASE
3575 /* Force CASE to have just one word */
3576 if (ctx->ctx_res_w == RES_CASE) {
3577 done_pipe(ctx, PIPE_SEQ);
3580 debug_printf_parse("done_word return 0\n");
3584 /* If a redirect is immediately preceded by a number, that number is
3585 * supposed to tell which file descriptor to redirect. This routine
3586 * looks for such preceding numbers. In an ideal world this routine
3587 * needs to handle all the following classes of redirects...
3588 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3589 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3590 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3591 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3592 * A -1 output from this program means no valid number was found, so the
3593 * caller should use the appropriate default for this redirection.
3595 static int redirect_opt_num(o_string *o)
3601 for (num = 0; num < o->length; num++) {
3602 if (!isdigit(o->data[num])) {
3606 num = atoi(o->data);
3611 static int parse_stream(o_string *dest, struct parse_context *ctx,
3612 struct in_str *input0, const char *end_trigger);
3614 #if ENABLE_HUSH_TICK
3615 static FILE *generate_stream_from_list(struct pipe *head)
3618 int pid, channel[2];
3621 /* *** NOMMU WARNING *** */
3622 /* By using vfork here, we suspend parent till child exits or execs.
3623 * If child will not do it before it fills the pipe, it can block forever
3624 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3626 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3627 * huge=`cat TESTFILE` # will block here forever
3630 pid = BB_MMU ? fork() : vfork();
3632 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3633 if (pid == 0) { /* child */
3634 if (ENABLE_HUSH_JOB)
3635 die_sleep = 0; /* let nofork's xfuncs die */
3636 close(channel[0]); /* NB: close _first_, then move fd! */
3637 xmove_fd(channel[1], 1);
3638 /* Prevent it from trying to handle ctrl-z etc */
3640 G.run_list_level = 1;
3642 /* Process substitution is not considered to be usual
3643 * 'command execution'.
3644 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3646 set_jobctrl_signals_to_IGN();
3648 /* Note: freeing 'head' here would break NOMMU. */
3649 _exit(run_list(head));
3652 pf = fdopen(channel[0], "r");
3654 /* 'head' is freed by the caller */
3657 /* Return code is exit status of the process that is run. */
3658 static int process_command_subs(o_string *dest,
3659 struct in_str *input,
3660 const char *subst_end)
3662 int retcode, ch, eol_cnt;
3663 o_string result = NULL_O_STRING;
3664 struct parse_context inner;
3666 struct in_str pipe_str;
3668 initialize_context(&inner);
3670 /* Recursion to generate command */
3671 retcode = parse_stream(&result, &inner, input, subst_end);
3673 return retcode; /* syntax error or EOF */
3674 done_word(&result, &inner);
3675 done_pipe(&inner, PIPE_SEQ);
3678 p = generate_stream_from_list(inner.list_head);
3681 close_on_exec_on(fileno(p));
3682 setup_file_in_str(&pipe_str, p);
3684 /* Now send results of command back into original context */
3686 while ((ch = i_getch(&pipe_str)) != EOF) {
3692 o_addchr(dest, '\n');
3695 o_addQchr(dest, ch);
3698 debug_printf("done reading from pipe, pclose()ing\n");
3699 /* This is the step that waits for the child. Should be pretty
3700 * safe, since we just read an EOF from its stdout. We could try
3701 * to do better, by using waitpid, and keeping track of background jobs
3702 * at the same time. That would be a lot of work, and contrary
3703 * to the KISS philosophy of this program. */
3704 retcode = fclose(p);
3705 free_pipe_list(inner.list_head, /* indent: */ 0);
3706 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3711 static int parse_group(o_string *dest, struct parse_context *ctx,
3712 struct in_str *input, int ch)
3714 /* dest contains characters seen prior to ( or {.
3715 * Typically it's empty, but for functions defs,
3716 * it contains function name (without '()'). */
3718 const char *endch = NULL;
3719 struct parse_context sub;
3720 struct command *command = ctx->command;
3722 debug_printf_parse("parse_group entered\n");
3723 #if ENABLE_HUSH_FUNCTIONS
3724 if (ch == 'F') { /* function definition? */
3725 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3726 //command->fname = dest->data;
3727 command->grp_type = GRP_FUNCTION;
3728 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3729 memset(dest, 0, sizeof(*dest));
3732 if (command->argv /* word [word](... */
3733 || dest->length /* word(... */
3734 || dest->nonnull /* ""(... */
3737 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3740 initialize_context(&sub);
3744 command->grp_type = GRP_SUBSHELL;
3746 rcode = parse_stream(dest, &sub, input, endch);
3748 done_word(dest, &sub); /* finish off the final word in the subcontext */
3749 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3750 command->group = sub.list_head;
3752 debug_printf_parse("parse_group return %d\n", rcode);
3754 /* command remains "open", available for possible redirects */
3757 #if ENABLE_HUSH_TICK
3758 /* Subroutines for copying $(...) and `...` things */
3759 static void add_till_backquote(o_string *dest, struct in_str *input);
3761 static void add_till_single_quote(o_string *dest, struct in_str *input)
3764 int ch = i_getch(input);
3772 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3773 static void add_till_double_quote(o_string *dest, struct in_str *input)
3776 int ch = i_getch(input);
3779 if (ch == '\\') { /* \x. Copy both chars. */
3781 ch = i_getch(input);
3787 add_till_backquote(dest, input);
3791 //if (ch == '$') ...
3794 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3796 * "Within the backquoted style of command substitution, backslash
3797 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3798 * The search for the matching backquote shall be satisfied by the first
3799 * backquote found without a preceding backslash; during this search,
3800 * if a non-escaped backquote is encountered within a shell comment,
3801 * a here-document, an embedded command substitution of the $(command)
3802 * form, or a quoted string, undefined results occur. A single-quoted
3803 * or double-quoted string that begins, but does not end, within the
3804 * "`...`" sequence produces undefined results."
3806 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3808 static void add_till_backquote(o_string *dest, struct in_str *input)
3811 int ch = i_getch(input);
3814 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3815 int ch2 = i_getch(input);
3816 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3825 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3826 * quoting and nested ()s.
3827 * "With the $(command) style of command substitution, all characters
3828 * following the open parenthesis to the matching closing parenthesis
3829 * constitute the command. Any valid shell script can be used for command,
3830 * except a script consisting solely of redirections which produces
3831 * unspecified results."
3833 * echo $(echo '(TEST)' BEST) (TEST) BEST
3834 * echo $(echo 'TEST)' BEST) TEST) BEST
3835 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3837 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3841 int ch = i_getch(input);
3851 add_till_single_quote(dest, input);
3856 add_till_double_quote(dest, input);
3860 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3861 ch = i_getch(input);
3869 #endif /* ENABLE_HUSH_TICK */
3871 /* Return code: 0 for OK, 1 for syntax error */
3872 static int handle_dollar(o_string *dest, struct in_str *input)
3875 int ch = i_peek(input); /* first character after the $ */
3876 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3878 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3882 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3884 debug_printf_parse(": '%c'\n", ch);
3885 o_addchr(dest, ch | quote_mask);
3888 if (!isalnum(ch) && ch != '_')
3892 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3893 } else if (isdigit(ch)) {
3896 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3897 debug_printf_parse(": '%c'\n", ch);
3898 o_addchr(dest, ch | quote_mask);
3899 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3900 } else switch (ch) {
3902 case '!': /* last bg pid */
3903 case '?': /* last exit code */
3904 case '#': /* number of args */
3905 case '*': /* args */
3906 case '@': /* args */
3907 goto make_one_char_var;
3909 bool first_char, all_digits;
3911 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3913 /* XXX maybe someone will try to escape the '}' */
3918 ch = i_getch(input);
3924 /* ${#var}: length of var contents */
3926 else if (isdigit(ch)) {
3932 if (expansion < 2 &&
3933 ((all_digits && !isdigit(ch)) ||
3934 (!all_digits && !isalnum(ch) && ch != '_')))
3936 /* handle parameter expansions
3937 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3942 case ':': /* null modifier */
3943 if (expansion == 0) {
3944 debug_printf_parse(": null modifier\n");
3950 #if 0 /* not implemented yet :( */
3951 case '#': /* remove prefix */
3952 case '%': /* remove suffix */
3953 if (expansion == 0) {
3954 debug_printf_parse(": remove suffix/prefix\n");
3961 case '-': /* default value */
3962 case '=': /* assign default */
3963 case '+': /* alternative */
3964 case '?': /* error indicate */
3965 debug_printf_parse(": parameter expansion\n");
3971 syntax("unterminated ${name}");
3972 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3978 debug_printf_parse(": '%c'\n", ch);
3979 o_addchr(dest, ch | quote_mask);
3983 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3986 #if ENABLE_HUSH_TICK
3988 //int pos = dest->length;
3990 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3991 o_addchr(dest, quote_mask | '`');
3992 add_till_closing_curly_brace(dest, input);
3993 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
3994 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4001 if (isalnum(ch)) { /* it's $_name or $_123 */
4007 /* still unhandled, but should be eventually */
4008 bb_error_msg("unhandled syntax: $%c", ch);
4012 o_addQchr(dest, '$');
4014 debug_printf_parse("handle_dollar return 0\n");
4018 /* Scan input, call done_word() whenever full IFS delimited word was seen.
4019 * Call done_pipe if '\n' was seen (and end_trigger != NULL).
4020 * Return code is 0 if end_trigger char is met,
4021 * -1 on EOF (but if end_trigger == NULL then return 0),
4022 * 1 for syntax error */
4023 static int parse_stream(o_string *dest, struct parse_context *ctx,
4024 struct in_str *input, const char *end_trigger)
4028 redir_type redir_style;
4029 int shadow_quote = dest->o_quote;
4032 /* Only double-quote state is handled in the state variable dest->o_quote.
4033 * A single-quote triggers a bypass of the main loop until its mate is
4034 * found. When recursing, quote state is passed in via dest->o_quote. */
4036 debug_printf_parse("parse_stream entered, end_trigger='%s' dest->o_assignment:%d\n", end_trigger, dest->o_assignment);
4041 ch = i_getch(input);
4045 next = i_peek(input);
4048 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
4049 ch, ch, m, dest->o_quote);
4050 if (m == CHAR_ORDINARY
4051 || (m != CHAR_SPECIAL && shadow_quote)
4054 syntax("unterminated \"");
4055 debug_printf_parse("parse_stream return 1: unterminated \"\n");
4058 o_addQchr(dest, ch);
4059 if ((dest->o_assignment == MAYBE_ASSIGNMENT
4060 || dest->o_assignment == WORD_IS_KEYWORD)
4062 && is_assignment(dest->data)
4064 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4068 if (m == CHAR_IFS) {
4069 if (done_word(dest, ctx)) {
4070 debug_printf_parse("parse_stream return 1: done_word!=0\n");
4075 /* If we aren't performing a substitution, treat
4076 * a newline as a command separator.
4077 * [why we don't handle it exactly like ';'? --vda] */
4078 if (end_trigger && ch == '\n') {
4079 #if ENABLE_HUSH_CASE
4080 /* "case ... in <newline> word) ..." -
4081 * newlines are ignored (but ';' wouldn't be) */
4082 if (dest->length == 0 // && argv[0] == NULL
4083 && ctx->ctx_res_w == RES_MATCH
4088 done_pipe(ctx, PIPE_SEQ);
4089 dest->o_assignment = MAYBE_ASSIGNMENT;
4093 if (!shadow_quote && strchr(end_trigger, ch)) {
4094 /* Special case: (...word) makes last word terminate,
4095 * as if ';' is seen */
4097 done_word(dest, ctx);
4099 done_pipe(ctx, PIPE_SEQ);
4100 dest->o_assignment = MAYBE_ASSIGNMENT;
4103 IF_HAS_KEYWORDS(|| (ctx->ctx_res_w == RES_NONE && ctx->old_flag == 0))
4105 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
4113 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
4114 /* ch is a special char and thus this word
4115 * cannot be an assignment: */
4116 dest->o_assignment = NOT_ASSIGNMENT;
4121 if (dest->length == 0 && !shadow_quote) {
4124 if (ch == EOF || ch == '\n')
4129 o_addQchr(dest, ch);
4135 debug_printf_parse("parse_stream return 1: \\<eof>\n");
4139 * "The backslash retains its special meaning [in "..."]
4140 * only when followed by one of the following characters:
4141 * $, `, ", \, or <newline>. A double quote may be quoted
4142 * within double quotes by preceding it with a backslash.
4143 * If enabled, history expansion will be performed unless
4144 * an ! appearing in double quotes is escaped using
4145 * a backslash. The backslash preceding the ! is not removed."
4147 if (shadow_quote) { //NOT SURE dest->o_quote) {
4148 if (strchr("$`\"\\", next) != NULL) {
4149 o_addqchr(dest, i_getch(input));
4151 o_addqchr(dest, '\\');
4154 o_addchr(dest, '\\');
4155 o_addchr(dest, i_getch(input));
4159 if (handle_dollar(dest, input) != 0) {
4160 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
4167 ch = i_getch(input);
4169 syntax("unterminated '");
4170 debug_printf_parse("parse_stream return 1: unterminated '\n");
4175 if (dest->o_assignment == NOT_ASSIGNMENT)
4176 o_addqchr(dest, ch);
4183 shadow_quote ^= 1; /* invert */
4184 if (dest->o_assignment == NOT_ASSIGNMENT)
4187 #if ENABLE_HUSH_TICK
4189 //int pos = dest->length;
4190 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4191 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
4192 add_till_backquote(dest, input);
4193 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4194 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4199 redir_fd = redirect_opt_num(dest);
4200 done_word(dest, ctx);
4201 redir_style = REDIRECT_OVERWRITE;
4203 redir_style = REDIRECT_APPEND;
4207 else if (next == '(') {
4208 syntax(">(process) not supported");
4209 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
4213 setup_redirect(ctx, redir_fd, redir_style, input);
4216 redir_fd = redirect_opt_num(dest);
4217 done_word(dest, ctx);
4218 redir_style = REDIRECT_INPUT;
4220 redir_style = REDIRECT_HEREIS;
4222 } else if (next == '>') {
4223 redir_style = REDIRECT_IO;
4227 else if (next == '(') {
4228 syntax("<(process) not supported");
4229 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
4233 setup_redirect(ctx, redir_fd, redir_style, input);
4236 #if ENABLE_HUSH_CASE
4239 done_word(dest, ctx);
4240 done_pipe(ctx, PIPE_SEQ);
4241 #if ENABLE_HUSH_CASE
4242 /* Eat multiple semicolons, detect
4243 * whether it means something special */
4249 if (ctx->ctx_res_w == RES_CASEI) {
4250 ctx->ctx_dsemicolon = 1;
4251 ctx->ctx_res_w = RES_MATCH;
4257 /* We just finished a cmd. New one may start
4258 * with an assignment */
4259 dest->o_assignment = MAYBE_ASSIGNMENT;
4262 done_word(dest, ctx);
4265 done_pipe(ctx, PIPE_AND);
4267 done_pipe(ctx, PIPE_BG);
4271 done_word(dest, ctx);
4272 #if ENABLE_HUSH_CASE
4273 if (ctx->ctx_res_w == RES_MATCH)
4274 break; /* we are in case's "word | word)" */
4276 if (next == '|') { /* || */
4278 done_pipe(ctx, PIPE_OR);
4280 /* we could pick up a file descriptor choice here
4281 * with redirect_opt_num(), but bash doesn't do it.
4282 * "echo foo 2| cat" yields "foo 2". */
4287 #if ENABLE_HUSH_CASE
4288 /* "case... in [(]word)..." - skip '(' */
4289 if (ctx->ctx_res_w == RES_MATCH
4290 && ctx->command->argv == NULL /* not (word|(... */
4291 && dest->length == 0 /* not word(... */
4292 && dest->nonnull == 0 /* not ""(... */
4297 #if ENABLE_HUSH_FUNCTIONS
4298 if (dest->length != 0 /* not just () but word() */
4299 && dest->nonnull == 0 /* not a"b"c() */
4300 && ctx->command->argv == NULL /* it's the first word */
4301 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4302 && i_peek(input) == ')'
4303 && !match_reserved_word(dest)
4305 bb_error_msg("seems like a function definition");
4308 //TODO: do it properly.
4309 ch = i_getch(input);
4310 } while (ch == ' ' || ch == '\n');
4312 syntax("was expecting {");
4313 debug_printf_parse("parse_stream return 1\n");
4316 ch = 'F'; /* magic value */
4320 if (parse_group(dest, ctx, input, ch) != 0) {
4321 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
4326 #if ENABLE_HUSH_CASE
4327 if (ctx->ctx_res_w == RES_MATCH)
4331 /* proper use of this character is caught by end_trigger:
4332 * if we see {, we call parse_group(..., end_trigger='}')
4333 * and it will match } earlier (not here). */
4334 syntax("unexpected } or )");
4335 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
4339 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4342 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
4348 static void set_in_charmap(const char *set, int code)
4351 G.charmap[(unsigned char)*set++] = code;
4354 static void update_charmap(void)
4356 G.ifs = getenv("IFS");
4359 /* Precompute a list of 'flow through' behavior so it can be treated
4360 * quickly up front. Computation is necessary because of IFS.
4361 * Special case handling of IFS == " \t\n" is not implemented.
4362 * The charmap[] array only really needs two bits each,
4363 * and on most machines that would be faster (reduced L1 cache use).
4365 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4366 #if ENABLE_HUSH_TICK
4367 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4369 set_in_charmap("\\$\"", CHAR_SPECIAL);
4371 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4372 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4375 /* Most recursion does not come through here, the exception is
4376 * from builtin_source() and builtin_eval() */
4377 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
4379 struct parse_context ctx;
4380 o_string temp = NULL_O_STRING;
4384 initialize_context(&ctx);
4386 #if ENABLE_HUSH_INTERACTIVE
4387 inp->promptmode = 0; /* PS1 */
4389 /* We will stop & execute after each ';' or '\n'.
4390 * Example: "sleep 9999; echo TEST" + ctrl-C:
4391 * TEST should be printed */
4392 temp.o_assignment = MAYBE_ASSIGNMENT;
4393 rcode = parse_stream(&temp, &ctx, inp, ";\n");
4395 if (rcode != 1 && ctx.old_flag != 0) {
4399 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
4400 done_word(&temp, &ctx);
4401 done_pipe(&ctx, PIPE_SEQ);
4402 debug_print_tree(ctx.list_head, 0);
4403 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
4404 run_and_free_list(ctx.list_head);
4406 /* We arrive here also if rcode == 1 (error in parse_stream) */
4408 if (ctx.old_flag != 0) {
4413 /*temp.nonnull = 0; - o_free does it below */
4414 /*temp.o_quote = 0; - o_free does it below */
4415 free_pipe_list(ctx.list_head, /* indent: */ 0);
4416 /* Discard all unprocessed line input, force prompt on */
4418 #if ENABLE_HUSH_INTERACTIVE
4423 /* loop on syntax errors, return on EOF: */
4424 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
4428 static int parse_and_run_string(const char *s, int parse_flag)
4430 struct in_str input;
4431 setup_string_in_str(&input, s);
4432 return parse_and_run_stream(&input, parse_flag);
4435 static int parse_and_run_file(FILE *f)
4438 struct in_str input;
4439 setup_file_in_str(&input, f);
4440 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
4445 /* Make sure we have a controlling tty. If we get started under a job
4446 * aware app (like bash for example), make sure we are now in charge so
4447 * we don't fight over who gets the foreground */
4448 static void setup_job_control(void)
4452 shell_pgrp = getpgrp();
4454 /* If we were ran as 'hush &',
4455 * sleep until we are in the foreground. */
4456 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4457 /* Send TTIN to ourself (should stop us) */
4458 kill(- shell_pgrp, SIGTTIN);
4459 shell_pgrp = getpgrp();
4462 /* We _must_ restore tty pgrp on fatal signals */
4463 set_fatal_signals_to_sigexit();
4465 /* Put ourselves in our own process group. */
4466 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4467 /* Grab control of the terminal. */
4468 tcsetpgrp(G.interactive_fd, getpid());
4472 static int set_mode(const char cstate, const char mode)
4474 int state = (cstate == '-' ? 1 : 0);
4476 case 'n': G.fake_mode = state; break;
4477 case 'x': /*G.debug_mode = state;*/ break;
4478 default: return EXIT_FAILURE;
4480 return EXIT_SUCCESS;
4483 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4484 int hush_main(int argc, char **argv)
4486 static const struct variable const_shell_ver = {
4488 .varstr = (char*)hush_version_str,
4489 .max_len = 1, /* 0 can provoke free(name) */
4497 struct variable *cur_var;
4501 G.root_pid = getpid();
4503 /* Deal with HUSH_VERSION */
4504 G.shell_ver = const_shell_ver; /* copying struct here */
4505 G.top_var = &G.shell_ver;
4506 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4507 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4508 /* Initialize our shell local variables with the values
4509 * currently living in the environment */
4510 cur_var = G.top_var;
4513 char *value = strchr(*e, '=');
4514 if (value) { /* paranoia */
4515 cur_var->next = xzalloc(sizeof(*cur_var));
4516 cur_var = cur_var->next;
4517 cur_var->varstr = *e;
4518 cur_var->max_len = strlen(*e);
4519 cur_var->flg_export = 1;
4523 debug_printf_env("putenv '%s'\n", hush_version_str);
4524 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4526 #if ENABLE_FEATURE_EDITING
4527 G.line_input_state = new_line_input_t(FOR_SHELL);
4529 /* XXX what should these be while sourcing /etc/profile? */
4530 G.global_argc = argc;
4531 G.global_argv = argv;
4532 /* Initialize some more globals to non-zero values */
4534 #if ENABLE_HUSH_INTERACTIVE
4535 if (ENABLE_FEATURE_EDITING)
4536 cmdedit_set_initial_prompt();
4540 if (EXIT_SUCCESS) /* otherwise is already done */
4541 G.last_return_code = EXIT_SUCCESS;
4543 if (argv[0] && argv[0][0] == '-') {
4544 debug_printf("sourcing /etc/profile\n");
4545 input = fopen_for_read("/etc/profile");
4546 if (input != NULL) {
4547 close_on_exec_on(fileno(input));
4548 parse_and_run_file(input);
4554 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4555 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4558 G.global_argv = argv + optind;
4559 if (!argv[optind]) {
4560 /* -c 'script' (no params): prevent empty $0 */
4561 *--G.global_argv = argv[0];
4563 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4564 G.global_argc = argc - optind;
4565 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
4568 /* Well, we cannot just declare interactiveness,
4569 * we have to have some stuff (ctty, etc) */
4570 /* G.interactive_fd++; */
4573 /* "-s" means "read from stdin", but this is how we always
4574 * operate, so simply do nothing here. */
4578 if (!set_mode('-', opt))
4582 fprintf(stderr, "Usage: sh [FILE]...\n"
4583 " or: sh -c command [args]...\n\n");
4591 /* A shell is interactive if the '-i' flag was given, or if all of
4592 * the following conditions are met:
4594 * no arguments remaining or the -s flag given
4595 * standard input is a terminal
4596 * standard output is a terminal
4597 * Refer to Posix.2, the description of the 'sh' utility. */
4598 if (argv[optind] == NULL && input == stdin
4599 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4601 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4602 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4603 if (G.saved_tty_pgrp >= 0) {
4604 /* try to dup to high fd#, >= 255 */
4605 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4606 if (G.interactive_fd < 0) {
4607 /* try to dup to any fd */
4608 G.interactive_fd = dup(STDIN_FILENO);
4609 if (G.interactive_fd < 0)
4611 G.interactive_fd = 0;
4613 // TODO: track & disallow any attempts of user
4614 // to (inadvertently) close/redirect it
4617 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4618 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4619 if (G.interactive_fd) {
4620 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4621 /* Looks like they want an interactive shell */
4622 setup_job_control();
4623 /* -1 is special - makes xfuncs longjmp, not exit
4624 * (we reset die_sleep = 0 whereever we [v]fork) */
4626 if (setjmp(die_jmp)) {
4627 /* xfunc has failed! die die die */
4628 hush_exit(xfunc_error_retval);
4631 #elif ENABLE_HUSH_INTERACTIVE
4632 /* no job control compiled, only prompt/line editing */
4633 if (argv[optind] == NULL && input == stdin
4634 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4636 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4637 if (G.interactive_fd < 0) {
4638 /* try to dup to any fd */
4639 G.interactive_fd = dup(STDIN_FILENO);
4640 if (G.interactive_fd < 0)
4642 G.interactive_fd = 0;
4644 if (G.interactive_fd) {
4645 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4648 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4650 /* POSIX allows shell to re-enable SIGCHLD
4651 * even if it was SIG_IGN on entry */
4652 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4653 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4655 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4656 if (G.interactive_fd) {
4657 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4658 printf("Enter 'help' for a list of built-in commands.\n\n");
4662 if (argv[optind] == NULL) {
4663 opt = parse_and_run_file(stdin);
4665 debug_printf("\nrunning script '%s'\n", argv[optind]);
4666 G.global_argv = argv + optind;
4667 G.global_argc = argc - optind;
4668 input = xfopen_for_read(argv[optind]);
4669 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4670 opt = parse_and_run_file(input);
4675 #if ENABLE_FEATURE_CLEAN_UP
4677 if (G.cwd != bb_msg_unknown)
4679 cur_var = G.top_var->next;
4681 struct variable *tmp = cur_var;
4682 if (!cur_var->max_len)
4683 free(cur_var->varstr);
4684 cur_var = cur_var->next;
4688 hush_exit(opt ? opt : G.last_return_code);
4693 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4694 int lash_main(int argc, char **argv)
4696 //bb_error_msg("lash is deprecated, please use hush instead");
4697 return hush_main(argc, argv);
4705 static int builtin_trap(char **argv)
4712 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4715 /* No args: print all trapped. This isn't 100% correct as we should
4716 * be escaping the cmd so that it can be pasted back in ...
4718 for (i = 0; i < NSIG; ++i)
4720 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4721 return EXIT_SUCCESS;
4726 /* if first arg is decimal: reset all specified */
4727 sig = bb_strtou(*++argv, NULL, 10);
4733 sig = get_signum(*argv++);
4734 if (sig < 0 || sig >= NSIG) {
4736 /* mimic bash message exactly */
4737 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4742 G.traps[sig] = xstrdup(new_cmd);
4744 debug_printf("trap: setting SIG%s (%i) to '%s'",
4745 get_signame(sig), sig, G.traps[sig]);
4747 /* There is no signal for 0 (EXIT) */
4752 sigaddset(&G.blocked_set, sig);
4754 /* there was a trap handler, we are removing it
4755 * (if sig has non-DFL handling,
4756 * we don't need to do anything) */
4757 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4759 sigdelset(&G.blocked_set, sig);
4761 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4766 /* first arg is "-": reset all specified to default */
4767 /* first arg is "": ignore all specified */
4768 /* everything else: execute first arg upon signal */
4770 bb_error_msg("trap: invalid arguments");
4771 return EXIT_FAILURE;
4773 if (LONE_DASH(*argv))
4781 static int builtin_true(char **argv UNUSED_PARAM)
4786 static int builtin_test(char **argv)
4793 return test_main(argc, argv - argc);
4796 static int builtin_echo(char **argv)
4803 return echo_main(argc, argv - argc);
4806 static int builtin_eval(char **argv)
4808 int rcode = EXIT_SUCCESS;
4811 char *str = expand_strvec_to_string(argv + 1);
4812 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4814 rcode = G.last_return_code;
4819 static int builtin_cd(char **argv)
4822 if (argv[1] == NULL) {
4823 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4824 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4825 newdir = getenv("HOME") ? : "/";
4828 if (chdir(newdir)) {
4829 printf("cd: %s: %s\n", newdir, strerror(errno));
4830 return EXIT_FAILURE;
4833 return EXIT_SUCCESS;
4836 static int builtin_exec(char **argv)
4838 if (argv[1] == NULL)
4839 return EXIT_SUCCESS; /* bash does this */
4844 // FIXME: if exec fails, bash does NOT exit! We do...
4845 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
4850 static int builtin_exit(char **argv)
4852 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4853 //puts("exit"); /* bash does it */
4854 // TODO: warn if we have background jobs: "There are stopped jobs"
4855 // On second consecutive 'exit', exit anyway.
4856 if (argv[1] == NULL)
4857 hush_exit(G.last_return_code);
4858 /* mimic bash: exit 123abc == exit 255 + error msg */
4859 xfunc_error_retval = 255;
4860 /* bash: exit -2 == exit 254, no error msg */
4861 hush_exit(xatoi(argv[1]) & 0xff);
4864 static int builtin_export(char **argv)
4867 char *name = argv[1];
4871 // ash emits: export VAR='VAL'
4872 // bash: declare -x VAR="VAL"
4873 // (both also escape as needed (quotes, $, etc))
4878 return EXIT_SUCCESS;
4881 value = strchr(name, '=');
4883 /* They are exporting something without a =VALUE */
4884 struct variable *var;
4886 var = get_local_var(name);
4888 var->flg_export = 1;
4889 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
4890 putenv(var->varstr);
4892 /* bash does not return an error when trying to export
4893 * an undefined variable. Do likewise. */
4894 return EXIT_SUCCESS;
4897 set_local_var(xstrdup(name), 1);
4898 return EXIT_SUCCESS;
4902 /* built-in 'fg' and 'bg' handler */
4903 static int builtin_fg_bg(char **argv)
4908 if (!G.interactive_fd)
4909 return EXIT_FAILURE;
4910 /* If they gave us no args, assume they want the last backgrounded task */
4912 for (pi = G.job_list; pi; pi = pi->next) {
4913 if (pi->jobid == G.last_jobid) {
4917 bb_error_msg("%s: no current job", argv[0]);
4918 return EXIT_FAILURE;
4920 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4921 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4922 return EXIT_FAILURE;
4924 for (pi = G.job_list; pi; pi = pi->next) {
4925 if (pi->jobid == jobnum) {
4929 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4930 return EXIT_FAILURE;
4932 // TODO: bash prints a string representation
4933 // of job being foregrounded (like "sleep 1 | cat")
4934 if (*argv[0] == 'f') {
4935 /* Put the job into the foreground. */
4936 tcsetpgrp(G.interactive_fd, pi->pgrp);
4939 /* Restart the processes in the job */
4940 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
4941 for (i = 0; i < pi->num_cmds; i++) {
4942 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
4943 pi->cmds[i].is_stopped = 0;
4945 pi->stopped_cmds = 0;
4947 i = kill(- pi->pgrp, SIGCONT);
4949 if (errno == ESRCH) {
4950 delete_finished_bg_job(pi);
4951 return EXIT_SUCCESS;
4953 bb_perror_msg("kill (SIGCONT)");
4957 if (*argv[0] == 'f') {
4959 return checkjobs_and_fg_shell(pi);
4961 return EXIT_SUCCESS;
4965 #if ENABLE_HUSH_HELP
4966 static int builtin_help(char **argv UNUSED_PARAM)
4968 const struct built_in_command *x;
4970 printf("\nBuilt-in commands:\n");
4971 printf("-------------------\n");
4972 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
4973 printf("%s\t%s\n", x->cmd, x->descr);
4976 return EXIT_SUCCESS;
4981 static int builtin_jobs(char **argv UNUSED_PARAM)
4984 const char *status_string;
4986 for (job = G.job_list; job; job = job->next) {
4987 if (job->alive_cmds == job->stopped_cmds)
4988 status_string = "Stopped";
4990 status_string = "Running";
4992 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
4994 return EXIT_SUCCESS;
4998 static int builtin_pwd(char **argv UNUSED_PARAM)
5001 return EXIT_SUCCESS;
5004 static int builtin_read(char **argv)
5007 const char *name = argv[1] ? argv[1] : "REPLY";
5009 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5010 return set_local_var(string, 0);
5013 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5014 * built-in 'set' handler
5016 * set [-abCefhmnuvx] [-o option] [argument...]
5017 * set [+abCefhmnuvx] [+o option] [argument...]
5018 * set -- [argument...]
5021 * Implementations shall support the options in both their hyphen and
5022 * plus-sign forms. These options can also be specified as options to sh.
5024 * Write out all variables and their values: set
5025 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5026 * Turn on the -x and -v options: set -xv
5027 * Unset all positional parameters: set --
5028 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5029 * Set the positional parameters to the expansion of x, even if x expands
5030 * with a leading '-' or '+': set -- $x
5032 * So far, we only support "set -- [argument...]" and some of the short names.
5034 static int builtin_set(char **argv)
5037 char **pp, **g_argv;
5038 char *arg = *++argv;
5042 for (e = G.top_var; e; e = e->next)
5044 return EXIT_SUCCESS;
5048 if (!strcmp(arg, "--")) {
5053 if (arg[0] == '+' || arg[0] == '-') {
5054 for (n = 1; arg[n]; ++n)
5055 if (set_mode(arg[0], arg[n]))
5061 } while ((arg = *++argv) != NULL);
5062 /* Now argv[0] is 1st argument */
5064 /* Only reset global_argv if we didn't process anything */
5066 return EXIT_SUCCESS;
5069 /* NB: G.global_argv[0] ($0) is never freed/changed */
5070 g_argv = G.global_argv;
5071 if (G.global_args_malloced) {
5077 G.global_args_malloced = 1;
5078 pp = xzalloc(sizeof(pp[0]) * 2);
5079 pp[0] = g_argv[0]; /* retain $0 */
5082 /* This realloc's G.global_argv */
5083 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5090 return EXIT_SUCCESS;
5092 /* Nothing known, so abort */
5094 bb_error_msg("set: %s: invalid option", arg);
5095 return EXIT_FAILURE;
5098 static int builtin_shift(char **argv)
5104 if (n >= 0 && n < G.global_argc) {
5105 if (G.global_args_malloced) {
5108 free(G.global_argv[m++]);
5111 memmove(&G.global_argv[1], &G.global_argv[n+1],
5112 G.global_argc * sizeof(G.global_argv[0]));
5113 return EXIT_SUCCESS;
5115 return EXIT_FAILURE;
5118 static int builtin_source(char **argv)
5123 if (argv[1] == NULL)
5124 return EXIT_FAILURE;
5126 /* XXX search through $PATH is missing */
5127 input = fopen_for_read(argv[1]);
5129 bb_error_msg("can't open '%s'", argv[1]);
5130 return EXIT_FAILURE;
5132 close_on_exec_on(fileno(input));
5134 /* Now run the file */
5135 /* XXX argv and argc are broken; need to save old G.global_argv
5136 * (pointer only is OK!) on this stack frame,
5137 * set G.global_argv=argv+1, recurse, and restore. */
5138 status = parse_and_run_file(input);
5143 static int builtin_umask(char **argv)
5146 const char *arg = argv[1];
5148 new_umask = bb_strtou(arg, NULL, 8);
5150 return EXIT_FAILURE;
5152 new_umask = umask(0);
5153 printf("%.3o\n", (unsigned) new_umask);
5156 return EXIT_SUCCESS;
5159 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5160 static int builtin_unset(char **argv)
5167 return EXIT_SUCCESS;
5170 if (argv[1][0] == '-') {
5171 switch (argv[1][1]) {
5173 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5175 bb_error_msg("unset: %s: invalid option", argv[1]);
5176 return EXIT_FAILURE;
5184 if (unset_local_var(argv[i]))
5187 #if ENABLE_HUSH_FUNCTIONS
5189 unset_local_func(argv[i]);
5195 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5196 static int builtin_wait(char **argv)
5198 int ret = EXIT_SUCCESS;
5201 if (*++argv == NULL) {
5202 /* Don't care about wait results */
5203 /* Note 1: must wait until there are no more children */
5204 /* Note 2: must be interruptible */
5206 * $ sleep 3 & sleep 6 & wait
5211 * $ sleep 3 & sleep 6 & wait
5215 * ^C <-- after ~4 sec from keyboard
5218 sigaddset(&G.blocked_set, SIGCHLD);
5219 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5222 if (errno == ECHILD)
5224 /* Wait for SIGCHLD or any other signal of interest */
5225 /* sigtimedwait with infinite timeout: */
5226 sig = sigwaitinfo(&G.blocked_set, NULL);
5228 sig = check_and_run_traps(sig);
5229 if (sig && sig != SIGCHLD) { /* see note 2 */
5235 sigdelset(&G.blocked_set, SIGCHLD);
5236 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5240 /* This is probably buggy wrt interruptible-ness */
5242 pid_t pid = bb_strtou(*argv, NULL, 10);
5244 /* mimic bash message */
5245 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5246 return EXIT_FAILURE;
5248 if (waitpid(pid, &status, 0) == pid) {
5249 if (WIFSIGNALED(status))
5250 ret = 128 + WTERMSIG(status);
5251 else if (WIFEXITED(status))
5252 ret = WEXITSTATUS(status);
5256 bb_perror_msg("wait %s", *argv);
5265 #if ENABLE_HUSH_LOOPS
5266 static int builtin_break(char **argv)
5268 if (G.depth_of_loop == 0) {
5269 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5270 return EXIT_SUCCESS; /* bash compat */
5272 G.flag_break_continue++; /* BC_BREAK = 1 */
5273 G.depth_break_continue = 1;
5275 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5276 if (errno || !G.depth_break_continue || argv[2]) {
5277 bb_error_msg("%s: bad arguments", argv[0]);
5278 G.flag_break_continue = BC_BREAK;
5279 G.depth_break_continue = UINT_MAX;
5282 if (G.depth_of_loop < G.depth_break_continue)
5283 G.depth_break_continue = G.depth_of_loop;
5284 return EXIT_SUCCESS;
5287 static int builtin_continue(char **argv)
5289 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5290 return builtin_break(argv);
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