1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * <(list) and >(list) Process Substitution
42 * Here Documents ( << word )
45 * Parameter Expansion for substring processing ${var#word} ${var%word}
47 * Bash stuff maybe optional enable:
48 * &> and >& redirection of stdout+stderr
50 * reserved words: [[ ]] function select
51 * substrings ${var:1:5}
54 * job handling woefully incomplete and buggy (improved --vda)
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * change { and } from special chars to reserved words
58 * builtins: return, trap, ulimit
59 * test magic exec with redirection only
60 * follow IFS rules more precisely, including update semantics
61 * figure out what to do with backslash-newline
62 * propagate syntax errors, die on resource errors?
63 * continuation lines, both explicit and implicit - done?
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
68 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
70 //#include "applet_tables.h" doesn't work
72 /* #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 !ENABLE_HUSH_INTERACTIVE
93 #undef ENABLE_FEATURE_EDITING
94 #define ENABLE_FEATURE_EDITING 0
95 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
96 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
99 /* Do we support ANY keywords? */
100 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
101 #define HAS_KEYWORDS 1
102 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
103 #define IF_HAS_NO_KEYWORDS(...)
105 #define HAS_KEYWORDS 0
106 #define IF_HAS_KEYWORDS(...)
107 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
110 /* Keep unconditionally on for now */
113 #define ENABLE_HUSH_FUNCTIONS 0
116 /* If you comment out one of these below, it will be #defined later
117 * to perform debug printfs to stderr: */
118 #define debug_printf(...) do {} while (0)
119 /* Finer-grained debug switches */
120 #define debug_printf_parse(...) do {} while (0)
121 #define debug_print_tree(a, b) do {} while (0)
122 #define debug_printf_exec(...) do {} while (0)
123 #define debug_printf_env(...) do {} while (0)
124 #define debug_printf_jobs(...) do {} while (0)
125 #define debug_printf_expand(...) do {} while (0)
126 #define debug_printf_glob(...) do {} while (0)
127 #define debug_printf_list(...) do {} while (0)
128 #define debug_printf_subst(...) do {} while (0)
129 #define debug_printf_clean(...) do {} while (0)
132 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
135 #ifndef debug_printf_parse
136 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
139 #ifndef debug_printf_exec
140 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
143 #ifndef debug_printf_env
144 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
147 #ifndef debug_printf_jobs
148 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
154 #ifndef debug_printf_expand
155 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
156 #define DEBUG_EXPAND 1
158 #define DEBUG_EXPAND 0
161 #ifndef debug_printf_glob
162 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
168 #ifndef debug_printf_list
169 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
172 #ifndef debug_printf_subst
173 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
176 #ifndef debug_printf_clean
177 /* broken, of course, but OK for testing */
178 static const char *indenter(int i)
180 static const char blanks[] ALIGN1 =
182 return &blanks[sizeof(blanks) - i - 1];
184 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
185 #define DEBUG_CLEAN 1
189 static void debug_print_strings(const char *prefix, char **vv)
191 fprintf(stderr, "%s:\n", prefix);
193 fprintf(stderr, " '%s'\n", *vv++);
196 #define debug_print_strings(prefix, vv) ((void)0)
200 * Leak hunting. Use hush_leaktool.sh for post-processing.
202 #ifdef FOR_HUSH_LEAKTOOL
203 static void *xxmalloc(int lineno, size_t size)
205 void *ptr = xmalloc((size + 0xff) & ~0xff);
206 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
209 static void *xxrealloc(int lineno, void *ptr, size_t size)
211 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
212 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
215 static char *xxstrdup(int lineno, const char *str)
217 char *ptr = xstrdup(str);
218 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
221 static void xxfree(void *ptr)
223 fdprintf(2, "free %p\n", ptr);
226 #define xmalloc(s) xxmalloc(__LINE__, s)
227 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
228 #define xstrdup(s) xxstrdup(__LINE__, s)
229 #define free(p) xxfree(p)
233 #define ERR_PTR ((void*)(long)1)
235 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
237 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
239 #define SPECIAL_VAR_SYMBOL 3
241 typedef enum redir_type {
243 REDIRECT_OVERWRITE = 2,
249 /* The descrip member of this structure is only used to make
250 * debugging output pretty */
251 static const struct {
253 signed char default_fd;
257 { O_RDONLY, 0, "<" },
258 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
259 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
260 { O_RDONLY, -1, "<<" },
264 typedef enum pipe_style {
271 typedef enum reserved_style {
280 #if ENABLE_HUSH_LOOPS
287 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
292 /* two pseudo-keywords support contrived "case" syntax: */
293 RES_MATCH , /* "word)" */
294 RES_CASEI , /* "this command is inside CASE" */
301 struct redir_struct {
302 struct redir_struct *next;
303 char *rd_filename; /* filename */
304 int fd; /* file descriptor being redirected */
305 int dup; /* -1, or file descriptor being duplicated */
306 smallint /*enum redir_type*/ rd_type;
310 pid_t pid; /* 0 if exited */
311 int assignment_cnt; /* how many argv[i] are assignments? */
312 smallint is_stopped; /* is the command currently running? */
313 smallint grp_type; /* GRP_xxx */
314 struct pipe *group; /* if non-NULL, this "prog" is {} group,
315 * subshell, or a compound statement */
316 char **argv; /* command name and arguments */
317 struct redir_struct *redirects; /* I/O redirections */
319 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
320 * and on execution these are substituted with their values.
321 * Substitution can make _several_ words out of one argv[n]!
322 * Example: argv[0]=='.^C*^C.' here: echo .$*.
323 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
326 #define GRP_SUBSHELL 1
327 #if ENABLE_HUSH_FUNCTIONS
328 #define GRP_FUNCTION 2
333 int num_cmds; /* total number of commands in job */
334 int alive_cmds; /* number of commands running (not exited) */
335 int stopped_cmds; /* number of commands alive, but stopped */
337 int jobid; /* job number */
338 pid_t pgrp; /* process group ID for the job */
339 char *cmdtext; /* name of job */
341 struct command *cmds; /* array of commands in pipe */
342 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
343 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
344 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
347 /* This holds pointers to the various results of parsing */
348 struct parse_context {
349 /* linked list of pipes */
350 struct pipe *list_head;
351 /* last pipe (being constructed right now) */
353 /* last command in pipe (being constructed right now) */
354 struct command *command;
355 /* last redirect in command->redirects list */
356 struct redir_struct *pending_redirect;
359 smallint ctx_inverted; /* "! cmd | cmd" */
361 smallint ctx_dsemicolon; /* ";;" seen */
363 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
365 /* group we are enclosed in:
366 * example 1: "{ { false; ..."
367 * example 2: "if true; then { false; ..."
368 * example 3: "if true; then if false; ..."
369 * when we find closing "}" / "fi" / whatever, we move list_head
370 * into stack->command->group and delete ourself.
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 /* Protect newly added chars against globbing
395 * (by prepending \ to *, ?, [, \) */
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, /* \, $, ", maybe ` */
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 */
451 #define G_interactive_fd (G.interactive_fd)
453 #define G_interactive_fd 0
455 #if ENABLE_FEATURE_EDITING
456 line_input_t *line_input_state;
462 pid_t saved_tty_pgrp;
464 struct pipe *job_list;
465 struct pipe *toplevel_list;
466 //// smallint ctrl_z_flag;
468 smallint flag_SIGINT;
469 #if ENABLE_HUSH_LOOPS
470 smallint flag_break_continue;
473 /* These four support $?, $#, and $1 */
474 smalluint last_return_code;
475 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
476 smalluint global_args_malloced;
477 /* how many non-NULL argv's we have. NB: $# + 1 */
480 #if ENABLE_HUSH_LOOPS
481 unsigned depth_break_continue;
482 unsigned depth_of_loop;
486 struct variable *top_var; /* = &G.shell_ver (set in main()) */
487 struct variable shell_ver;
488 /* Signal and trap handling */
489 // unsigned count_SIGCHLD;
490 // unsigned handled_SIGCHLD;
491 /* which signals have non-DFL handler (even with no traps set)? */
492 unsigned non_DFL_mask;
493 char **traps; /* char *traps[NSIG] */
494 sigset_t blocked_set;
495 sigset_t inherited_set;
496 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
497 #if ENABLE_FEATURE_SH_STANDALONE
498 struct nofork_save_area nofork_save;
501 sigjmp_buf toplevel_jb;
504 #define G (*ptr_to_globals)
505 /* Not #defining name to G.name - this quickly gets unwieldy
506 * (too many defines). Also, I actually prefer to see when a variable
507 * is global, thus "G." prefix is a useful hint */
508 #define INIT_G() do { \
509 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
513 /* Function prototypes for builtins */
514 static int builtin_cd(char **argv);
515 static int builtin_echo(char **argv);
516 static int builtin_eval(char **argv);
517 static int builtin_exec(char **argv);
518 static int builtin_exit(char **argv);
519 static int builtin_export(char **argv);
521 static int builtin_fg_bg(char **argv);
522 static int builtin_jobs(char **argv);
525 static int builtin_help(char **argv);
527 static int builtin_pwd(char **argv);
528 static int builtin_read(char **argv);
529 static int builtin_test(char **argv);
530 static int builtin_trap(char **argv);
531 static int builtin_true(char **argv);
532 static int builtin_set(char **argv);
533 static int builtin_shift(char **argv);
534 static int builtin_source(char **argv);
535 static int builtin_umask(char **argv);
536 static int builtin_unset(char **argv);
537 static int builtin_wait(char **argv);
538 #if ENABLE_HUSH_LOOPS
539 static int builtin_break(char **argv);
540 static int builtin_continue(char **argv);
542 //static int builtin_not_written(char **argv);
544 /* Table of built-in functions. They can be forked or not, depending on
545 * context: within pipes, they fork. As simple commands, they do not.
546 * When used in non-forking context, they can change global variables
547 * in the parent shell process. If forked, of course they cannot.
548 * For example, 'unset foo | whatever' will parse and run, but foo will
549 * still be set at the end. */
550 struct built_in_command {
552 int (*function)(char **argv);
555 #define BLTIN(cmd, func, help) { cmd, func, help }
557 #define BLTIN(cmd, func, help) { cmd, func }
561 /* For now, echo and test are unconditionally enabled.
562 * Maybe make it configurable? */
563 static const struct built_in_command bltins[] = {
564 BLTIN("." , builtin_source, "Run commands in a file"),
565 BLTIN(":" , builtin_true, "No-op"),
566 BLTIN("[" , builtin_test, "Test condition"),
568 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
570 #if ENABLE_HUSH_LOOPS
571 BLTIN("break" , builtin_break, "Exit from a loop"),
573 BLTIN("cd" , builtin_cd, "Change directory"),
574 #if ENABLE_HUSH_LOOPS
575 BLTIN("continue", builtin_continue, "Start new loop iteration"),
577 BLTIN("echo" , builtin_echo, "Write to stdout"),
578 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
579 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
580 BLTIN("exit" , builtin_exit, "Exit"),
581 BLTIN("export", builtin_export, "Set environment variable"),
583 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
584 BLTIN("jobs" , builtin_jobs, "List active jobs"),
586 BLTIN("pwd" , builtin_pwd, "Print current directory"),
587 BLTIN("read" , builtin_read, "Input environment variable"),
588 // BLTIN("return", builtin_not_written, "Return from a function"),
589 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
590 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
591 BLTIN("test" , builtin_test, "Test condition"),
592 BLTIN("trap" , builtin_trap, "Trap signals"),
593 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
594 BLTIN("umask" , builtin_umask, "Set file creation mask"),
595 BLTIN("unset" , builtin_unset, "Unset environment variable"),
596 BLTIN("wait" , builtin_wait, "Wait for process"),
598 BLTIN("help" , builtin_help, "List shell built-in commands"),
604 static void maybe_die(const char *notice, const char *msg)
606 /* Was using fancy stuff:
607 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
608 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
609 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
610 #if ENABLE_HUSH_INTERACTIVE
611 if (G_interactive_fd)
614 fp(msg ? "%s: %s" : notice, notice, msg);
617 #define syntax(msg) maybe_die("syntax error", msg);
619 /* Debug -- trick gcc to expand __LINE__ and convert to string */
620 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
621 #define _syntax(msg, line) __syntax(msg, line)
622 #define syntax(msg) _syntax(msg, __LINE__)
625 static int glob_needed(const char *s)
630 if (*s == '*' || *s == '[' || *s == '?')
637 static int is_assignment(const char *s)
639 if (!s || !(isalpha(*s) || *s == '_'))
642 while (isalnum(*s) || *s == '_')
647 /* Replace each \x with x in place, return ptr past NUL. */
648 static char *unbackslash(char *src)
654 if ((*dst++ = *src++) == '\0')
660 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
681 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
682 v[count1 + count2] = NULL;
685 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
689 static char **add_string_to_strings(char **strings, char *add)
694 return add_strings_to_strings(strings, v, /*dup:*/ 0);
697 static void putenv_all(char **strings)
702 debug_printf_env("putenv '%s'\n", *strings);
707 static char **putenv_all_and_save_old(char **strings)
717 eq = strchr(*strings, '=');
720 v = getenv(*strings);
723 /* v points to VAL in VAR=VAL, go back to VAR */
724 v -= (eq - *strings) + 1;
725 old = add_string_to_strings(old, v);
734 static void free_strings_and_unsetenv(char **strings, int unset)
744 debug_printf_env("unsetenv '%s'\n", *v);
752 static void free_strings(char **strings)
754 free_strings_and_unsetenv(strings, 0);
758 /* Basic theory of signal handling in shell
759 * ========================================
760 * This does not describe what hush does, rather, it is current understanding
761 * what it _should_ do. If it doesn't, it's a bug.
762 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
764 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
765 * is finished or backgrounded. It is the same in interactive and
766 * non-interactive shells, and is the same regardless of whether
767 * a user trap handler is installed or a shell special one is in effect.
768 * ^C or ^Z from keyboard seem to execute "at once" because it usually
769 * backgrounds (i.e. stops) or kills all members of currently running
772 * Wait builtin in interruptible by signals for which user trap is set
773 * or by SIGINT in interactive shell.
775 * Trap handlers will execute even within trap handlers. (right?)
777 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
779 * If job control is off, backgrounded commands ("cmd &")
780 * have SIGINT, SIGQUIT set to SIG_IGN.
782 * Commands run in command substitution ("`cmd`")
783 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
785 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
786 * by the shell from its parent.
788 * Siganls which differ from SIG_DFL action
789 * (note: child (i.e., [v]forked) shell is not an interactive shell):
792 * SIGTERM (interactive): ignore
793 * SIGHUP (interactive):
794 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
795 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
796 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
797 * that all pipe members are stopped) (right?)
798 * SIGINT (interactive): wait for last pipe, ignore the rest
799 * of the command line, show prompt. NB: ^C does not send SIGINT
800 * to interactive shell while shell is waiting for a pipe,
801 * since shell is bg'ed (is not in foreground process group).
802 * (check/expand this)
803 * Example 1: this waits 5 sec, but does not execute ls:
804 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
805 * Example 2: this does not wait and does not execute ls:
806 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
807 * Example 3: this does not wait 5 sec, but executes ls:
808 * "sleep 5; ls -l" + press ^C
810 * (What happens to signals which are IGN on shell start?)
811 * (What happens with signal mask on shell start?)
813 * Implementation in hush
814 * ======================
815 * We use in-kernel pending signal mask to determine which signals were sent.
816 * We block all signals which we don't want to take action immediately,
817 * i.e. we block all signals which need to have special handling as described
818 * above, and all signals which have traps set.
819 * After each pipe execution, we extract any pending signals via sigtimedwait()
822 * unsigned non_DFL_mask: a mask of such "special" signals
823 * sigset_t blocked_set: current blocked signal set
826 * clear bit in blocked_set unless it is also in non_DFL
827 * "trap 'cmd' SIGxxx":
828 * set bit in blocked_set (even if 'cmd' is '')
829 * after [v]fork, if we plan to be a shell:
830 * nothing for {} child shell (say, "true | { true; true; } | true")
831 * unset all traps if () shell. [TODO]
832 * after [v]fork, if we plan to exec:
833 * POSIX says pending signal mask is cleared in child - no need to clear it.
834 * Restore blocked signal set to one inherited by shell just prior to exec.
836 * Note: as a result, we do not use signal handlers much. The only uses
837 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
838 * and to restore tty pgrp on signal-induced exit.
840 * TODO: check/fix wait builtin to be interruptible.
843 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
845 // G.count_SIGCHLD++;
848 /* called once at shell init */
849 static void init_signal_mask(void)
852 unsigned mask = (1 << SIGQUIT);
853 if (G_interactive_fd) {
859 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
864 G.non_DFL_mask = mask;
866 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
870 sigaddset(&G.blocked_set, sig);
874 sigdelset(&G.blocked_set, SIGCHLD);
875 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
878 static int check_and_run_traps(int sig)
880 static const struct timespec zero_timespec = { 0, 0 };
881 smalluint save_rcode;
887 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
892 if (G.traps && G.traps[sig]) {
893 if (G.traps[sig][0]) {
894 /* We have user-defined handler */
895 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
896 save_rcode = G.last_return_code;
899 G.last_return_code = save_rcode;
900 } /* else: "" trap, ignoring signal */
903 /* not a trap: special action */
906 // G.count_SIGCHLD++;
915 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
924 /* Restores tty foreground process group, and exits.
925 * May be called as signal handler for fatal signal
926 * (will faithfully resend signal to itself, producing correct exit state)
927 * or called directly with -EXITCODE.
928 * We also call it if xfunc is exiting. */
929 static void sigexit(int sig) NORETURN;
930 static void sigexit(int sig)
932 /* Disable all signals: job control, SIGPIPE, etc. */
933 sigprocmask_allsigs(SIG_BLOCK);
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);
940 /* Not a signal, just exit */
944 kill_myself_with_sig(sig); /* does not return */
948 static void maybe_set_sighandler(int sig)
950 void (*handler)(int);
951 /* non_DFL_mask'ed signals are, well, masked,
952 * no need to set handler for them.
954 if (!((G.non_DFL_mask >> sig) & 1)) {
955 handler = signal(sig, sigexit);
956 if (handler == SIG_IGN) /* oops... restore back to IGN! */
957 signal(sig, handler);
960 /* Used only to set handler to restore pgrp on exit */
961 static void set_fatal_signals_to_sigexit(void)
964 maybe_set_sighandler(SIGILL );
965 maybe_set_sighandler(SIGFPE );
966 maybe_set_sighandler(SIGBUS );
967 maybe_set_sighandler(SIGSEGV);
968 maybe_set_sighandler(SIGTRAP);
969 } /* else: hush is perfect. what SEGV? */
971 maybe_set_sighandler(SIGABRT);
973 /* bash 3.2 seems to handle these just like 'fatal' ones */
974 maybe_set_sighandler(SIGPIPE);
975 maybe_set_sighandler(SIGALRM);
976 maybe_set_sighandler(SIGHUP );
978 /* if we aren't interactive... but in this case
979 * we never want to restore pgrp on exit, and this fn is not called */
980 /*maybe_set_sighandler(SIGTERM);*/
981 /*maybe_set_sighandler(SIGINT );*/
986 #define set_fatal_signals_to_sigexit(handler) ((void)0)
990 /* Restores tty foreground process group, and exits. */
991 static void hush_exit(int exitcode) NORETURN;
992 static void hush_exit(int exitcode)
994 if (G.traps && G.traps[0] && G.traps[0][0]) {
995 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1001 fflush(NULL); /* flush all streams */
1002 sigexit(- (exitcode & 0xff));
1009 static const char *set_cwd(void)
1011 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1012 * we must not try to free(bb_msg_unknown) */
1013 if (G.cwd == bb_msg_unknown)
1015 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1017 G.cwd = bb_msg_unknown;
1022 /* Get/check local shell variables */
1023 static struct variable *get_local_var(const char *name)
1025 struct variable *cur;
1031 for (cur = G.top_var; cur; cur = cur->next) {
1032 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1038 static const char *get_local_var_value(const char *src)
1040 struct variable *var = get_local_var(src);
1042 return strchr(var->varstr, '=') + 1;
1046 /* str holds "NAME=VAL" and is expected to be malloced.
1047 * We take ownership of it.
1048 * flg_export is used by:
1051 * -1: if NAME is set, leave export status alone
1052 * if NAME is not set, do not export
1054 static int set_local_var(char *str, int flg_export)
1056 struct variable *cur;
1060 value = strchr(str, '=');
1061 if (!value) { /* not expected to ever happen? */
1066 name_len = value - str + 1; /* including '=' */
1067 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1069 if (strncmp(cur->varstr, str, name_len) != 0) {
1071 /* Bail out. Note that now cur points
1072 * to last var in linked list */
1078 /* We found an existing var with this name */
1080 if (cur->flg_read_only) {
1081 bb_error_msg("%s: readonly variable", str);
1085 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1086 unsetenv(str); /* just in case */
1088 if (strcmp(cur->varstr, str) == 0) {
1093 if (cur->max_len >= strlen(str)) {
1094 /* This one is from startup env, reuse space */
1095 strcpy(cur->varstr, str);
1098 /* max_len == 0 signifies "malloced" var, which we can
1099 * (and has to) free */
1103 goto set_str_and_exp;
1106 /* Not found - create next variable struct */
1107 cur->next = xzalloc(sizeof(*cur));
1113 if (flg_export == 1)
1114 cur->flg_export = 1;
1115 if (cur->flg_export) {
1116 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1117 return putenv(cur->varstr);
1122 static int unset_local_var(const char *name)
1124 struct variable *cur;
1125 struct variable *prev = prev; /* for gcc */
1129 return EXIT_SUCCESS;
1130 name_len = strlen(name);
1133 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1134 if (cur->flg_read_only) {
1135 bb_error_msg("%s: readonly variable", name);
1136 return EXIT_FAILURE;
1138 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1139 * is ro, and we cannot reach this code on the 1st pass */
1140 prev->next = cur->next;
1141 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1142 bb_unsetenv(cur->varstr);
1146 return EXIT_SUCCESS;
1151 return EXIT_SUCCESS;
1154 #if ENABLE_SH_MATH_SUPPORT
1155 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1156 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1157 static char *endofname(const char *name)
1165 if (!is_in_name(*p))
1171 static void arith_set_local_var(const char *name, const char *val, int flags)
1173 /* arith code doesnt malloc space, so do it for it */
1174 char *var = xasprintf("%s=%s", name, val);
1175 set_local_var(var, flags);
1183 static int static_get(struct in_str *i)
1192 static int static_peek(struct in_str *i)
1197 #if ENABLE_HUSH_INTERACTIVE
1199 static void cmdedit_set_initial_prompt(void)
1201 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1202 G.PS1 = getenv("PS1");
1209 static const char* setup_prompt_string(int promptmode)
1211 const char *prompt_str;
1212 debug_printf("setup_prompt_string %d ", promptmode);
1213 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1214 /* Set up the prompt */
1215 if (promptmode == 0) { /* PS1 */
1217 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1222 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1223 debug_printf("result '%s'\n", prompt_str);
1227 static void get_user_input(struct in_str *i)
1230 const char *prompt_str;
1232 prompt_str = setup_prompt_string(i->promptmode);
1233 #if ENABLE_FEATURE_EDITING
1234 /* Enable command line editing only while a command line
1235 * is actually being read */
1238 /* buglet: SIGINT will not make new prompt to appear _at once_,
1239 * only after <Enter>. (^C will work) */
1240 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1241 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1242 check_and_run_traps(0);
1243 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1244 i->eof_flag = (r < 0);
1245 if (i->eof_flag) { /* EOF/error detected */
1246 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1247 G.user_input_buf[1] = '\0';
1252 fputs(prompt_str, stdout);
1254 G.user_input_buf[0] = r = fgetc(i->file);
1255 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1256 //do we need check_and_run_traps(0)? (maybe only if stdin)
1257 } while (G.flag_SIGINT);
1258 i->eof_flag = (r == EOF);
1260 i->p = G.user_input_buf;
1263 #endif /* INTERACTIVE */
1265 /* This is the magic location that prints prompts
1266 * and gets data back from the user */
1267 static int file_get(struct in_str *i)
1271 /* If there is data waiting, eat it up */
1272 if (i->p && *i->p) {
1273 #if ENABLE_HUSH_INTERACTIVE
1277 if (i->eof_flag && !*i->p)
1280 /* need to double check i->file because we might be doing something
1281 * more complicated by now, like sourcing or substituting. */
1282 #if ENABLE_HUSH_INTERACTIVE
1283 if (G_interactive_fd && i->promptme && i->file == stdin) {
1286 } while (!*i->p); /* need non-empty line */
1287 i->promptmode = 1; /* PS2 */
1292 ch = fgetc(i->file);
1294 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1295 #if ENABLE_HUSH_INTERACTIVE
1302 /* All the callers guarantee this routine will never be
1303 * used right after a newline, so prompting is not needed.
1305 static int file_peek(struct in_str *i)
1308 if (i->p && *i->p) {
1309 if (i->eof_flag && !i->p[1])
1313 ch = fgetc(i->file);
1314 i->eof_flag = (ch == EOF);
1315 i->peek_buf[0] = ch;
1316 i->peek_buf[1] = '\0';
1318 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1322 static void setup_file_in_str(struct in_str *i, FILE *f)
1324 i->peek = file_peek;
1326 #if ENABLE_HUSH_INTERACTIVE
1328 i->promptmode = 0; /* PS1 */
1334 static void setup_string_in_str(struct in_str *i, const char *s)
1336 i->peek = static_peek;
1337 i->get = static_get;
1338 #if ENABLE_HUSH_INTERACTIVE
1340 i->promptmode = 0; /* PS1 */
1350 #define B_CHUNK (32 * sizeof(char*))
1352 static void o_reset(o_string *o)
1360 static void o_free(o_string *o)
1363 memset(o, 0, sizeof(*o));
1366 static void o_grow_by(o_string *o, int len)
1368 if (o->length + len > o->maxlen) {
1369 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1370 o->data = xrealloc(o->data, 1 + o->maxlen);
1374 static void o_addchr(o_string *o, int ch)
1376 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1378 o->data[o->length] = ch;
1380 o->data[o->length] = '\0';
1383 static void o_addstr(o_string *o, const char *str, int len)
1386 memcpy(&o->data[o->length], str, len);
1388 o->data[o->length] = '\0';
1391 static void o_addstrauto(o_string *o, const char *str)
1393 o_addstr(o, str, strlen(str) + 1);
1396 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1401 && (*str != '*' && *str != '?' && *str != '[')
1409 /* My analysis of quoting semantics tells me that state information
1410 * is associated with a destination, not a source.
1412 static void o_addqchr(o_string *o, int ch)
1415 char *found = strchr("*?[\\", ch);
1420 o->data[o->length] = '\\';
1423 o->data[o->length] = ch;
1425 o->data[o->length] = '\0';
1428 static void o_addQchr(o_string *o, int ch)
1431 if (o->o_escape && strchr("*?[\\", ch)) {
1433 o->data[o->length] = '\\';
1437 o->data[o->length] = ch;
1439 o->data[o->length] = '\0';
1442 static void o_addQstr(o_string *o, const char *str, int len)
1445 o_addstr(o, str, len);
1451 int ordinary_cnt = strcspn(str, "*?[\\");
1452 if (ordinary_cnt > len) /* paranoia */
1454 o_addstr(o, str, ordinary_cnt);
1455 if (ordinary_cnt == len)
1457 str += ordinary_cnt;
1458 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1462 if (ch) { /* it is necessarily one of "*?[\\" */
1464 o->data[o->length] = '\\';
1468 o->data[o->length] = ch;
1470 o->data[o->length] = '\0';
1474 /* A special kind of o_string for $VAR and `cmd` expansion.
1475 * It contains char* list[] at the beginning, which is grown in 16 element
1476 * increments. Actual string data starts at the next multiple of 16 * (char*).
1477 * list[i] contains an INDEX (int!) into this string data.
1478 * It means that if list[] needs to grow, data needs to be moved higher up
1479 * but list[i]'s need not be modified.
1480 * NB: remembering how many list[i]'s you have there is crucial.
1481 * o_finalize_list() operation post-processes this structure - calculates
1482 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1484 #if DEBUG_EXPAND || DEBUG_GLOB
1485 static void debug_print_list(const char *prefix, o_string *o, int n)
1487 char **list = (char**)o->data;
1488 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1490 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1491 prefix, list, n, string_start, o->length, o->maxlen);
1493 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1494 o->data + (int)list[i] + string_start,
1495 o->data + (int)list[i] + string_start);
1499 const char *p = o->data + (int)list[n - 1] + string_start;
1500 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1504 #define debug_print_list(prefix, o, n) ((void)0)
1507 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1508 * in list[n] so that it points past last stored byte so far.
1509 * It returns n+1. */
1510 static int o_save_ptr_helper(o_string *o, int n)
1512 char **list = (char**)o->data;
1516 if (!o->has_empty_slot) {
1517 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1518 string_len = o->length - string_start;
1519 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1520 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1521 /* list[n] points to string_start, make space for 16 more pointers */
1522 o->maxlen += 0x10 * sizeof(list[0]);
1523 o->data = xrealloc(o->data, o->maxlen + 1);
1524 list = (char**)o->data;
1525 memmove(list + n + 0x10, list + n, string_len);
1526 o->length += 0x10 * sizeof(list[0]);
1528 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1530 /* We have empty slot at list[n], reuse without growth */
1531 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1532 string_len = o->length - string_start;
1533 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1534 o->has_empty_slot = 0;
1536 list[n] = (char*)(ptrdiff_t)string_len;
1540 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1541 static int o_get_last_ptr(o_string *o, int n)
1543 char **list = (char**)o->data;
1544 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1546 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1549 /* o_glob performs globbing on last list[], saving each result
1550 * as a new list[]. */
1551 static int o_glob(o_string *o, int n)
1557 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1559 return o_save_ptr_helper(o, n);
1560 pattern = o->data + o_get_last_ptr(o, n);
1561 debug_printf_glob("glob pattern '%s'\n", pattern);
1562 if (!glob_needed(pattern)) {
1564 o->length = unbackslash(pattern) - o->data;
1565 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1566 return o_save_ptr_helper(o, n);
1569 memset(&globdata, 0, sizeof(globdata));
1570 gr = glob(pattern, 0, NULL, &globdata);
1571 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1572 if (gr == GLOB_NOSPACE)
1573 bb_error_msg_and_die("out of memory during glob");
1574 if (gr == GLOB_NOMATCH) {
1575 globfree(&globdata);
1578 if (gr != 0) { /* GLOB_ABORTED ? */
1579 //TODO: testcase for bad glob pattern behavior
1580 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1582 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1583 char **argv = globdata.gl_pathv;
1584 o->length = pattern - o->data; /* "forget" pattern */
1586 o_addstrauto(o, *argv);
1587 n = o_save_ptr_helper(o, n);
1593 globfree(&globdata);
1595 debug_print_list("o_glob returning", o, n);
1599 /* If o->o_glob == 1, glob the string so far remembered.
1600 * Otherwise, just finish current list[] and start new */
1601 static int o_save_ptr(o_string *o, int n)
1603 if (o->o_glob) { /* if globbing is requested */
1604 /* If o->has_empty_slot, list[n] was already globbed
1605 * (if it was requested back then when it was filled)
1606 * so don't do that again! */
1607 if (!o->has_empty_slot)
1608 return o_glob(o, n); /* o_save_ptr_helper is inside */
1610 return o_save_ptr_helper(o, n);
1613 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1614 static char **o_finalize_list(o_string *o, int n)
1619 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1621 debug_print_list("finalized", o, n);
1622 debug_printf_expand("finalized n:%d\n", n);
1623 list = (char**)o->data;
1624 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1628 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1634 /* Expansion can recurse */
1635 #if ENABLE_HUSH_TICK
1636 static int process_command_subs(o_string *dest, const char *s);
1638 static char *expand_string_to_string(const char *str);
1639 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end);
1641 /* expand_strvec_to_strvec() takes a list of strings, expands
1642 * all variable references within and returns a pointer to
1643 * a list of expanded strings, possibly with larger number
1644 * of strings. (Think VAR="a b"; echo $VAR).
1645 * This new list is allocated as a single malloc block.
1646 * NULL-terminated list of char* pointers is at the beginning of it,
1647 * followed by strings themself.
1648 * Caller can deallocate entire list by single free(list). */
1650 /* Store given string, finalizing the word and starting new one whenever
1651 * we encounter IFS char(s). This is used for expanding variable values.
1652 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1653 static int expand_on_ifs(o_string *output, int n, const char *str)
1656 int word_len = strcspn(str, G.ifs);
1658 if (output->o_escape || !output->o_glob)
1659 o_addQstr(output, str, word_len);
1660 else /* protect backslashes against globbing up :) */
1661 o_addstr_duplicate_backslash(output, str, word_len);
1664 if (!*str) /* EOL - do not finalize word */
1666 o_addchr(output, '\0');
1667 debug_print_list("expand_on_ifs", output, n);
1668 n = o_save_ptr(output, n);
1669 str += strspn(str, G.ifs); /* skip ifs chars */
1671 debug_print_list("expand_on_ifs[1]", output, n);
1675 /* Expand all variable references in given string, adding words to list[]
1676 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1677 * to be filled). This routine is extremely tricky: has to deal with
1678 * variables/parameters with whitespace, $* and $@, and constructs like
1679 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1680 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1682 /* or_mask is either 0 (normal case) or 0x80
1683 * (expansion of right-hand side of assignment == 1-element expand.
1684 * It will also do no globbing, and thus we must not backslash-quote!) */
1686 char first_ch, ored_ch;
1693 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1694 debug_print_list("expand_vars_to_list", output, n);
1695 n = o_save_ptr(output, n);
1696 debug_print_list("expand_vars_to_list[0]", output, n);
1698 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1699 #if ENABLE_HUSH_TICK
1700 o_string subst_result = NULL_O_STRING;
1702 #if ENABLE_SH_MATH_SUPPORT
1703 char arith_buf[sizeof(arith_t)*3 + 2];
1705 o_addstr(output, arg, p - arg);
1706 debug_print_list("expand_vars_to_list[1]", output, n);
1708 p = strchr(p, SPECIAL_VAR_SYMBOL);
1710 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1711 /* "$@" is special. Even if quoted, it can still
1712 * expand to nothing (not even an empty string) */
1713 if ((first_ch & 0x7f) != '@')
1714 ored_ch |= first_ch;
1717 switch (first_ch & 0x7f) {
1718 /* Highest bit in first_ch indicates that var is double-quoted */
1720 val = utoa(G.root_pid);
1722 case '!': /* bg pid */
1723 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1725 case '?': /* exitcode */
1726 val = utoa(G.last_return_code);
1728 case '#': /* argc */
1729 if (arg[1] != SPECIAL_VAR_SYMBOL)
1730 /* actually, it's a ${#var} */
1732 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1737 if (!G.global_argv[i])
1739 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1740 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1741 smallint sv = output->o_escape;
1742 /* unquoted var's contents should be globbed, so don't escape */
1743 output->o_escape = 0;
1744 while (G.global_argv[i]) {
1745 n = expand_on_ifs(output, n, G.global_argv[i]);
1746 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1747 if (G.global_argv[i++][0] && G.global_argv[i]) {
1748 /* this argv[] is not empty and not last:
1749 * put terminating NUL, start new word */
1750 o_addchr(output, '\0');
1751 debug_print_list("expand_vars_to_list[2]", output, n);
1752 n = o_save_ptr(output, n);
1753 debug_print_list("expand_vars_to_list[3]", output, n);
1756 output->o_escape = sv;
1758 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1759 * and in this case should treat it like '$*' - see 'else...' below */
1760 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1762 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1763 if (++i >= G.global_argc)
1765 o_addchr(output, '\0');
1766 debug_print_list("expand_vars_to_list[4]", output, n);
1767 n = o_save_ptr(output, n);
1769 } else { /* quoted $*: add as one word */
1771 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1772 if (!G.global_argv[++i])
1775 o_addchr(output, G.ifs[0]);
1779 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1780 /* "Empty variable", used to make "" etc to not disappear */
1784 #if ENABLE_HUSH_TICK
1785 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1788 //TODO: can we just stuff it into "output" directly?
1789 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1790 process_command_subs(&subst_result, arg);
1791 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1792 val = subst_result.data;
1795 #if ENABLE_SH_MATH_SUPPORT
1796 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1797 arith_eval_hooks_t hooks;
1802 arg++; /* skip '+' */
1803 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1804 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1806 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1809 unsigned char c = *exp_str++;
1816 if (strchr(" \t+-*/%_", c) != NULL)
1818 c |= 0x20; /* tolower */
1819 if (c >= 'a' && c <= 'z')
1823 /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
1825 struct in_str input;
1826 o_string dest = NULL_O_STRING;
1828 setup_string_in_str(&input, arg);
1829 parse_stream_dquoted(&dest, &input, EOF);
1830 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1831 exp_str = expand_string_to_string(dest.data);
1832 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1836 hooks.lookupvar = get_local_var_value;
1837 hooks.setvar = arith_set_local_var;
1838 hooks.endofname = endofname;
1839 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1844 case -3: maybe_die("arith", "exponent less than 0"); break;
1845 case -2: maybe_die("arith", "divide by zero"); break;
1846 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1847 default: maybe_die("arith", "syntax error"); break;
1850 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1851 sprintf(arith_buf, arith_t_fmt, res);
1856 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1858 bool exp_len = false, exp_null = false;
1859 char *var = arg, exp_save, exp_op, *exp_word;
1862 arg[0] = first_ch & 0x7f;
1864 /* prepare for expansions */
1865 if (var[0] == '#') {
1866 /* handle length expansion ${#var} */
1870 /* maybe handle parameter expansion */
1871 exp_off = strcspn(var, ":-=+?");
1875 exp_save = var[exp_off];
1876 exp_null = exp_save == ':';
1877 exp_word = var + exp_off;
1878 if (exp_null) ++exp_word;
1879 exp_op = *exp_word++;
1880 var[exp_off] = '\0';
1884 /* lookup the variable in question */
1885 if (isdigit(var[0])) {
1886 /* handle_dollar() should have vetted var for us */
1888 if (i < G.global_argc)
1889 val = G.global_argv[i];
1890 /* else val remains NULL: $N with too big N */
1892 val = get_local_var_value(var);
1894 /* handle any expansions */
1896 debug_printf_expand("expand: length of '%s' = ", val);
1897 val = utoa(val ? strlen(val) : 0);
1898 debug_printf_expand("%s\n", val);
1899 } else if (exp_off) {
1900 /* we need to do an expansion */
1901 int exp_test = (!val || (exp_null && !val[0]));
1903 exp_test = !exp_test;
1904 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1905 exp_null ? "true" : "false", exp_test);
1908 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1912 if (exp_op == '=') {
1913 if (isdigit(var[0]) || var[0] == '#') {
1914 maybe_die(var, "special vars cannot assign in this way");
1917 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1918 sprintf(new_var, "%s=%s", var, val);
1919 set_local_var(new_var, -1);
1923 var[exp_off] = exp_save;
1928 #if ENABLE_HUSH_TICK
1931 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1932 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1934 /* unquoted var's contents should be globbed, so don't escape */
1935 smallint sv = output->o_escape;
1936 output->o_escape = 0;
1937 n = expand_on_ifs(output, n, val);
1939 output->o_escape = sv;
1941 } else { /* quoted $VAR, val will be appended below */
1942 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1945 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1947 o_addQstr(output, val, strlen(val));
1949 /* Do the check to avoid writing to a const string */
1950 if (*p != SPECIAL_VAR_SYMBOL)
1951 *p = SPECIAL_VAR_SYMBOL;
1953 #if ENABLE_HUSH_TICK
1954 o_free(&subst_result);
1957 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1960 debug_print_list("expand_vars_to_list[a]", output, n);
1961 /* this part is literal, and it was already pre-quoted
1962 * if needed (much earlier), do not use o_addQstr here! */
1963 o_addstrauto(output, arg);
1964 debug_print_list("expand_vars_to_list[b]", output, n);
1965 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1966 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1969 /* allow to reuse list[n] later without re-growth */
1970 output->has_empty_slot = 1;
1972 o_addchr(output, '\0');
1977 static char **expand_variables(char **argv, int or_mask)
1982 o_string output = NULL_O_STRING;
1984 if (or_mask & 0x100) {
1985 output.o_escape = 1; /* protect against globbing for "$var" */
1986 /* (unquoted $var will temporarily switch it off) */
1993 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1996 debug_print_list("expand_variables", &output, n);
1998 /* output.data (malloced in one block) gets returned in "list" */
1999 list = o_finalize_list(&output, n);
2000 debug_print_strings("expand_variables[1]", list);
2004 static char **expand_strvec_to_strvec(char **argv)
2006 return expand_variables(argv, 0x100);
2009 /* Used for expansion of right hand of assignments */
2010 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2012 static char *expand_string_to_string(const char *str)
2014 char *argv[2], **list;
2016 argv[0] = (char*)str;
2018 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2020 if (!list[0] || list[1])
2021 bb_error_msg_and_die("BUG in varexp2");
2022 /* actually, just move string 2*sizeof(char*) bytes back */
2023 overlapping_strcpy((char*)list, list[0]);
2024 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2028 /* Used for "eval" builtin */
2029 static char* expand_strvec_to_string(char **argv)
2033 list = expand_variables(argv, 0x80);
2034 /* Convert all NULs to spaces */
2039 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2040 bb_error_msg_and_die("BUG in varexp3");
2041 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2045 overlapping_strcpy((char*)list, list[0]);
2046 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2050 static char **expand_assignments(char **argv, int count)
2054 /* Expand assignments into one string each */
2055 for (i = 0; i < count; i++) {
2056 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2062 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2063 * and stderr if they are redirected. */
2064 static int setup_redirects(struct command *prog, int squirrel[])
2067 struct redir_struct *redir;
2069 for (redir = prog->redirects; redir; redir = redir->next) {
2070 if (redir->dup == -1 && redir->rd_filename == NULL) {
2071 /* something went wrong in the parse. Pretend it didn't happen */
2074 if (redir->dup == -1) {
2076 mode = redir_table[redir->rd_type].mode;
2077 //TODO: check redir for names like '\\'
2078 p = expand_string_to_string(redir->rd_filename);
2079 openfd = open_or_warn(p, mode);
2082 /* this could get lost if stderr has been redirected, but
2083 bash and ash both lose it as well (though zsh doesn't!) */
2087 openfd = redir->dup;
2090 if (openfd != redir->fd) {
2091 if (squirrel && redir->fd < 3) {
2092 squirrel[redir->fd] = dup(redir->fd);
2095 //close(openfd); // close(-3) ??!
2097 dup2(openfd, redir->fd);
2098 if (redir->dup == -1)
2106 static void restore_redirects(int squirrel[])
2109 for (i = 0; i < 3; i++) {
2112 /* We simply die on error */
2119 #if !defined(DEBUG_CLEAN)
2120 #define free_pipe_list(head, indent) free_pipe_list(head)
2121 #define free_pipe(pi, indent) free_pipe(pi)
2123 static void free_pipe_list(struct pipe *head, int indent);
2125 /* return code is the exit status of the pipe */
2126 static void free_pipe(struct pipe *pi, int indent)
2129 struct command *command;
2130 struct redir_struct *r, *rnext;
2133 if (pi->stopped_cmds > 0)
2135 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2136 for (i = 0; i < pi->num_cmds; i++) {
2137 command = &pi->cmds[i];
2138 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2139 if (command->argv) {
2140 for (a = 0, p = command->argv; *p; a++, p++) {
2141 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2143 free_strings(command->argv);
2144 command->argv = NULL;
2146 /* not "else if": on syntax error, we may have both! */
2147 if (command->group) {
2148 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2149 free_pipe_list(command->group, indent+3);
2150 debug_printf_clean("%s end group\n", indenter(indent));
2151 command->group = NULL;
2153 for (r = command->redirects; r; r = rnext) {
2154 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2156 /* guard against the case >$FOO, where foo is unset or blank */
2157 if (r->rd_filename) {
2158 debug_printf_clean(" %s\n", r->rd_filename);
2159 free(r->rd_filename);
2160 r->rd_filename = NULL;
2163 debug_printf_clean("&%d\n", r->dup);
2168 command->redirects = NULL;
2170 free(pi->cmds); /* children are an array, they get freed all at once */
2178 static void free_pipe_list(struct pipe *head, int indent)
2180 struct pipe *pi, *next;
2182 for (pi = head; pi; pi = next) {
2184 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2186 free_pipe(pi, indent);
2187 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2189 /*pi->next = NULL;*/
2196 typedef struct nommu_save_t {
2202 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2203 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2204 #define pseudo_exec(nommu_save, command, argv_expanded) \
2205 pseudo_exec(command, argv_expanded)
2208 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2210 * XXX no exit() here. If you don't exec, use _exit instead.
2211 * The at_exit handlers apparently confuse the calling process,
2212 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2213 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2214 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2218 const struct built_in_command *x;
2220 /* If a variable is assigned in a forest, and nobody listens,
2221 * was it ever really set?
2223 if (!argv[assignment_cnt])
2224 _exit(EXIT_SUCCESS);
2226 new_env = expand_assignments(argv, assignment_cnt);
2228 putenv_all(new_env);
2229 free(new_env); /* optional */
2231 nommu_save->new_env = new_env;
2232 nommu_save->old_env = putenv_all_and_save_old(new_env);
2234 if (argv_expanded) {
2235 argv = argv_expanded;
2237 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2239 nommu_save->argv = argv;
2244 * Check if the command matches any of the builtins.
2245 * Depending on context, this might be redundant. But it's
2246 * easier to waste a few CPU cycles than it is to figure out
2247 * if this is one of those cases.
2249 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2250 if (strcmp(argv[0], x->cmd) == 0) {
2251 debug_printf_exec("running builtin '%s'\n", argv[0]);
2252 rcode = x->function(argv);
2258 /* Check if the command matches any busybox applets */
2259 #if ENABLE_FEATURE_SH_STANDALONE
2260 if (strchr(argv[0], '/') == NULL) {
2261 int a = find_applet_by_name(argv[0]);
2263 if (APPLET_IS_NOEXEC(a)) {
2264 debug_printf_exec("running applet '%s'\n", argv[0]);
2265 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2266 run_applet_no_and_exit(a, argv);
2268 /* re-exec ourselves with the new arguments */
2269 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2270 execvp(bb_busybox_exec_path, argv);
2271 /* If they called chroot or otherwise made the binary no longer
2272 * executable, fall through */
2277 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2279 debug_printf_exec("execing '%s'\n", argv[0]);
2280 execvp(argv[0], argv);
2281 bb_perror_msg("can't exec '%s'", argv[0]);
2282 _exit(EXIT_FAILURE);
2285 static int run_list(struct pipe *pi);
2287 /* Called after [v]fork() in run_pipe()
2289 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2290 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2293 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2295 if (command->group) {
2297 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2300 debug_printf_exec("pseudo_exec: run_list\n");
2301 rcode = run_list(command->group);
2302 /* OK to leak memory by not calling free_pipe_list,
2303 * since this process is about to exit */
2308 /* Can happen. See what bash does with ">foo" by itself. */
2309 debug_printf("trying to pseudo_exec null command\n");
2310 _exit(EXIT_SUCCESS);
2314 static const char *get_cmdtext(struct pipe *pi)
2320 /* This is subtle. ->cmdtext is created only on first backgrounding.
2321 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2322 * On subsequent bg argv is trashed, but we won't use it */
2325 argv = pi->cmds[0].argv;
2326 if (!argv || !argv[0]) {
2327 pi->cmdtext = xzalloc(1);
2332 do len += strlen(*argv) + 1; while (*++argv);
2333 pi->cmdtext = p = xmalloc(len);
2334 argv = pi->cmds[0].argv;
2336 len = strlen(*argv);
2337 memcpy(p, *argv, len);
2345 static void insert_bg_job(struct pipe *pi)
2347 struct pipe *thejob;
2350 /* Linear search for the ID of the job to use */
2352 for (thejob = G.job_list; thejob; thejob = thejob->next)
2353 if (thejob->jobid >= pi->jobid)
2354 pi->jobid = thejob->jobid + 1;
2356 /* Add thejob to the list of running jobs */
2358 thejob = G.job_list = xmalloc(sizeof(*thejob));
2360 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2362 thejob->next = xmalloc(sizeof(*thejob));
2363 thejob = thejob->next;
2366 /* Physically copy the struct job */
2367 memcpy(thejob, pi, sizeof(struct pipe));
2368 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2369 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2370 for (i = 0; i < pi->num_cmds; i++) {
2371 // TODO: do we really need to have so many fields which are just dead weight
2372 // at execution stage?
2373 thejob->cmds[i].pid = pi->cmds[i].pid;
2374 /* all other fields are not used and stay zero */
2376 thejob->next = NULL;
2377 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2379 /* We don't wait for background thejobs to return -- append it
2380 to the list of backgrounded thejobs and leave it alone */
2381 if (G_interactive_fd)
2382 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2383 G.last_bg_pid = thejob->cmds[0].pid;
2384 G.last_jobid = thejob->jobid;
2387 static void remove_bg_job(struct pipe *pi)
2389 struct pipe *prev_pipe;
2391 if (pi == G.job_list) {
2392 G.job_list = pi->next;
2394 prev_pipe = G.job_list;
2395 while (prev_pipe->next != pi)
2396 prev_pipe = prev_pipe->next;
2397 prev_pipe->next = pi->next;
2400 G.last_jobid = G.job_list->jobid;
2405 /* Remove a backgrounded job */
2406 static void delete_finished_bg_job(struct pipe *pi)
2409 pi->stopped_cmds = 0;
2415 /* Check to see if any processes have exited -- if they
2416 * have, figure out why and see if a job has completed */
2417 static int checkjobs(struct pipe* fg_pipe)
2427 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2430 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2431 // /* avoid doing syscall, nothing there anyway */
2434 attributes = WUNTRACED;
2435 if (fg_pipe == NULL)
2436 attributes |= WNOHANG;
2438 /* Do we do this right?
2439 * bash-3.00# sleep 20 | false
2441 * [3]+ Stopped sleep 20 | false
2442 * bash-3.00# echo $?
2443 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2446 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2447 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2448 // + killall -STOP cat
2455 // i = G.count_SIGCHLD;
2456 childpid = waitpid(-1, &status, attributes);
2457 if (childpid <= 0) {
2458 if (childpid && errno != ECHILD)
2459 bb_perror_msg("waitpid");
2460 // else /* Until next SIGCHLD, waitpid's are useless */
2461 // G.handled_SIGCHLD = i;
2464 dead = WIFEXITED(status) || WIFSIGNALED(status);
2467 if (WIFSTOPPED(status))
2468 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2469 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2470 if (WIFSIGNALED(status))
2471 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2472 childpid, WTERMSIG(status), WEXITSTATUS(status));
2473 if (WIFEXITED(status))
2474 debug_printf_jobs("pid %d exited, exitcode %d\n",
2475 childpid, WEXITSTATUS(status));
2477 /* Were we asked to wait for fg pipe? */
2479 for (i = 0; i < fg_pipe->num_cmds; i++) {
2480 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2481 if (fg_pipe->cmds[i].pid != childpid)
2483 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2485 fg_pipe->cmds[i].pid = 0;
2486 fg_pipe->alive_cmds--;
2487 if (i == fg_pipe->num_cmds - 1) {
2488 /* last process gives overall exitstatus */
2489 rcode = WEXITSTATUS(status);
2490 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2493 fg_pipe->cmds[i].is_stopped = 1;
2494 fg_pipe->stopped_cmds++;
2496 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2497 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2498 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2499 /* All processes in fg pipe have exited/stopped */
2501 if (fg_pipe->alive_cmds)
2502 insert_bg_job(fg_pipe);
2506 /* There are still running processes in the fg pipe */
2507 goto wait_more; /* do waitpid again */
2509 /* it wasnt fg_pipe, look for process in bg pipes */
2513 /* We asked to wait for bg or orphaned children */
2514 /* No need to remember exitcode in this case */
2515 for (pi = G.job_list; pi; pi = pi->next) {
2516 for (i = 0; i < pi->num_cmds; i++) {
2517 if (pi->cmds[i].pid == childpid)
2518 goto found_pi_and_prognum;
2521 /* Happens when shell is used as init process (init=/bin/sh) */
2522 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2523 continue; /* do waitpid again */
2525 found_pi_and_prognum:
2528 pi->cmds[i].pid = 0;
2530 if (!pi->alive_cmds) {
2531 if (G_interactive_fd)
2532 printf(JOB_STATUS_FORMAT, pi->jobid,
2533 "Done", pi->cmdtext);
2534 delete_finished_bg_job(pi);
2538 pi->cmds[i].is_stopped = 1;
2542 } /* while (waitpid succeeds)... */
2548 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2551 int rcode = checkjobs(fg_pipe);
2552 /* Job finished, move the shell to the foreground */
2553 p = getpgid(0); /* pgid of our process */
2554 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2555 tcsetpgrp(G_interactive_fd, p);
2560 /* run_pipe() starts all the jobs, but doesn't wait for anything
2561 * to finish. See checkjobs().
2563 * return code is normally -1, when the caller has to wait for children
2564 * to finish to determine the exit status of the pipe. If the pipe
2565 * is a simple builtin command, however, the action is done by the
2566 * time run_pipe returns, and the exit code is provided as the
2569 * The input of the pipe is always stdin, the output is always
2570 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2571 * because it tries to avoid running the command substitution in
2572 * subshell, when that is in fact necessary. The subshell process
2573 * now has its stdout directed to the input of the appropriate pipe,
2574 * so this routine is noticeably simpler.
2576 * Returns -1 only if started some children. IOW: we have to
2577 * mask out retvals of builtins etc with 0xff!
2579 static int run_pipe(struct pipe *pi)
2583 int pipefds[2]; /* pipefds[0] is for reading */
2584 struct command *command;
2585 char **argv_expanded;
2587 const struct built_in_command *x;
2589 /* it is not always needed, but we aim to smaller code */
2590 int squirrel[] = { -1, -1, -1 };
2592 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2594 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2600 pi->stopped_cmds = 0;
2602 /* Check if this is a simple builtin (not part of a pipe).
2603 * Builtins within pipes have to fork anyway, and are handled in
2604 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2606 command = &(pi->cmds[0]);
2608 #if ENABLE_HUSH_FUNCTIONS
2609 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2610 /* We "execute" function definition */
2611 bb_error_msg("here we ought to remember function definition, and go on");
2612 return EXIT_SUCCESS;
2616 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2617 debug_printf("non-subshell grouping\n");
2618 setup_redirects(command, squirrel);
2619 debug_printf_exec(": run_list\n");
2620 rcode = run_list(command->group) & 0xff;
2621 restore_redirects(squirrel);
2622 debug_printf_exec("run_pipe return %d\n", rcode);
2623 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2627 argv = command->argv;
2628 argv_expanded = NULL;
2630 if (single_and_fg && argv != NULL) {
2631 char **new_env = NULL;
2632 char **old_env = NULL;
2634 i = command->assignment_cnt;
2635 if (i != 0 && argv[i] == NULL) {
2636 /* assignments, but no command: set local environment */
2637 for (i = 0; argv[i] != NULL; i++) {
2638 debug_printf("local environment set: %s\n", argv[i]);
2639 p = expand_string_to_string(argv[i]);
2640 set_local_var(p, 0);
2642 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2645 /* Expand the rest into (possibly) many strings each */
2646 argv_expanded = expand_strvec_to_strvec(argv + i);
2648 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2649 if (strcmp(argv_expanded[0], x->cmd) != 0)
2651 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2652 debug_printf("exec with redirects only\n");
2653 setup_redirects(command, NULL);
2654 rcode = EXIT_SUCCESS;
2655 goto clean_up_and_ret1;
2657 debug_printf("builtin inline %s\n", argv_expanded[0]);
2658 /* XXX setup_redirects acts on file descriptors, not FILEs.
2659 * This is perfect for work that comes after exec().
2660 * Is it really safe for inline use? Experimentally,
2661 * things seem to work with glibc. */
2662 setup_redirects(command, squirrel);
2663 new_env = expand_assignments(argv, command->assignment_cnt);
2664 old_env = putenv_all_and_save_old(new_env);
2665 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2666 rcode = x->function(argv_expanded) & 0xff;
2667 #if ENABLE_FEATURE_SH_STANDALONE
2670 restore_redirects(squirrel);
2671 free_strings_and_unsetenv(new_env, 1);
2672 putenv_all(old_env);
2673 free(old_env); /* not free_strings()! */
2675 free(argv_expanded);
2676 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2677 debug_printf_exec("run_pipe return %d\n", rcode);
2680 #if ENABLE_FEATURE_SH_STANDALONE
2681 i = find_applet_by_name(argv_expanded[0]);
2682 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2683 setup_redirects(command, squirrel);
2684 save_nofork_data(&G.nofork_save);
2685 new_env = expand_assignments(argv, command->assignment_cnt);
2686 old_env = putenv_all_and_save_old(new_env);
2687 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2688 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2689 goto clean_up_and_ret;
2694 /* NB: argv_expanded may already be created, and that
2695 * might include `cmd` runs! Do not rerun it! We *must*
2696 * use argv_expanded if it's non-NULL */
2698 /* Going to fork a child per each pipe member */
2702 for (i = 0; i < pi->num_cmds; i++) {
2704 volatile nommu_save_t nommu_save;
2705 nommu_save.new_env = NULL;
2706 nommu_save.old_env = NULL;
2707 nommu_save.argv = NULL;
2709 command = &(pi->cmds[i]);
2710 if (command->argv) {
2711 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2713 debug_printf_exec(": pipe member with no argv\n");
2715 /* pipes are inserted between pairs of commands */
2718 if ((i + 1) < pi->num_cmds)
2721 command->pid = BB_MMU ? fork() : vfork();
2722 if (!command->pid) { /* child */
2724 die_sleep = 0; /* let nofork's xfuncs die */
2726 /* Every child adds itself to new process group
2727 * with pgid == pid_of_first_child_in_pipe */
2728 if (G.run_list_level == 1 && G_interactive_fd) {
2731 if (pgrp < 0) /* true for 1st process only */
2733 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2734 /* We do it in *every* child, not just first,
2736 tcsetpgrp(G_interactive_fd, pgrp);
2740 xmove_fd(nextin, 0);
2741 xmove_fd(pipefds[1], 1); /* write end */
2743 close(pipefds[0]); /* read end */
2744 /* Like bash, explicit redirects override pipes,
2745 * and the pipe fd is available for dup'ing. */
2746 setup_redirects(command, NULL);
2748 /* Restore default handlers just prior to exec */
2749 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2751 /* Stores to nommu_save list of env vars putenv'ed
2752 * (NOMMU, on MMU we don't need that) */
2753 /* cast away volatility... */
2754 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2755 /* pseudo_exec() does not return */
2759 /* Clean up after vforked child */
2760 free(nommu_save.argv);
2761 free_strings_and_unsetenv(nommu_save.new_env, 1);
2762 putenv_all(nommu_save.old_env);
2764 free(argv_expanded);
2765 argv_expanded = NULL;
2766 if (command->pid < 0) { /* [v]fork failed */
2767 /* Clearly indicate, was it fork or vfork */
2768 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2772 /* Second and next children need to know pid of first one */
2774 pi->pgrp = command->pid;
2780 if ((i + 1) < pi->num_cmds)
2781 close(pipefds[1]); /* write end */
2782 /* Pass read (output) pipe end to next iteration */
2783 nextin = pipefds[0];
2786 if (!pi->alive_cmds) {
2787 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2791 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2795 #ifndef debug_print_tree
2796 static void debug_print_tree(struct pipe *pi, int lvl)
2798 static const char *const PIPE[] = {
2804 static const char *RES[] = {
2805 [RES_NONE ] = "NONE" ,
2808 [RES_THEN ] = "THEN" ,
2809 [RES_ELIF ] = "ELIF" ,
2810 [RES_ELSE ] = "ELSE" ,
2813 #if ENABLE_HUSH_LOOPS
2814 [RES_FOR ] = "FOR" ,
2815 [RES_WHILE] = "WHILE",
2816 [RES_UNTIL] = "UNTIL",
2818 [RES_DONE ] = "DONE" ,
2820 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2823 #if ENABLE_HUSH_CASE
2824 [RES_CASE ] = "CASE" ,
2825 [RES_MATCH] = "MATCH",
2826 [RES_CASEI] = "CASEI",
2827 [RES_ESAC ] = "ESAC" ,
2829 [RES_XXXX ] = "XXXX" ,
2830 [RES_SNTX ] = "SNTX" ,
2832 static const char *const GRPTYPE[] = {
2835 #if ENABLE_HUSH_FUNCTIONS
2844 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2845 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2847 while (prn < pi->num_cmds) {
2848 struct command *command = &pi->cmds[prn];
2849 char **argv = command->argv;
2851 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2852 if (command->group) {
2853 fprintf(stderr, " group %s: (argv=%p)\n",
2854 GRPTYPE[command->grp_type],
2856 debug_print_tree(command->group, lvl+1);
2860 if (argv) while (*argv) {
2861 fprintf(stderr, " '%s'", *argv);
2864 fprintf(stderr, "\n");
2873 /* NB: called by pseudo_exec, and therefore must not modify any
2874 * global data until exec/_exit (we can be a child after vfork!) */
2875 static int run_list(struct pipe *pi)
2877 #if ENABLE_HUSH_CASE
2878 char *case_word = NULL;
2880 #if ENABLE_HUSH_LOOPS
2881 struct pipe *loop_top = NULL;
2882 char *for_varname = NULL;
2883 char **for_lcur = NULL;
2884 char **for_list = NULL;
2886 smallint flag_skip = 1;
2887 smalluint rcode = 0; /* probably just for compiler */
2888 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2889 smalluint cond_code = 0;
2891 enum { cond_code = 0, };
2893 /*enum reserved_style*/ smallint rword = RES_NONE;
2894 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2896 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2898 #if ENABLE_HUSH_LOOPS
2899 /* Check syntax for "for" */
2900 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2901 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2903 /* current word is FOR or IN (BOLD in comments below) */
2904 if (cpipe->next == NULL) {
2905 syntax("malformed for");
2906 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2909 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2910 if (cpipe->next->res_word == RES_DO)
2912 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2913 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2914 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2916 syntax("malformed for");
2917 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2923 /* Past this point, all code paths should jump to ret: label
2924 * in order to return, no direct "return" statements please.
2925 * This helps to ensure that no memory is leaked. */
2927 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2930 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2931 * We are saving state before entering outermost list ("while...done")
2932 * so that ctrl-Z will correctly background _entire_ outermost list,
2933 * not just a part of it (like "sleep 1 | exit 2") */
2934 if (++G.run_list_level == 1 && G_interactive_fd) {
2935 if (sigsetjmp(G.toplevel_jb, 1)) {
2936 /* ctrl-Z forked and we are parent; or ctrl-C.
2937 * Sighandler has longjmped us here */
2938 signal(SIGINT, SIG_IGN);
2939 signal(SIGTSTP, SIG_IGN);
2940 /* Restore level (we can be coming from deep inside
2942 G.run_list_level = 1;
2943 #if ENABLE_FEATURE_SH_STANDALONE
2944 if (G.nofork_save.saved) { /* if save area is valid */
2945 debug_printf_jobs("exiting nofork early\n");
2946 restore_nofork_data(&G.nofork_save);
2949 //// if (G.ctrl_z_flag) {
2950 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2951 //// * Remember this child as background job */
2952 //// insert_bg_job(pi);
2954 /* ctrl-C. We just stop doing whatever we were doing */
2957 USE_HUSH_LOOPS(loop_top = NULL;)
2958 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2962 //// /* ctrl-Z handler will store pid etc in pi */
2963 //// G.toplevel_list = pi;
2964 //// G.ctrl_z_flag = 0;
2965 ////#if ENABLE_FEATURE_SH_STANDALONE
2966 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2968 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2969 //// signal(SIGINT, handler_ctrl_c);
2973 /* Go through list of pipes, (maybe) executing them. */
2974 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
2978 IF_HAS_KEYWORDS(rword = pi->res_word;)
2979 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2980 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
2981 rword, cond_code, skip_more_for_this_rword);
2982 #if ENABLE_HUSH_LOOPS
2983 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
2984 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
2986 /* start of a loop: remember where loop starts */
2991 if (rword == skip_more_for_this_rword && flag_skip) {
2992 if (pi->followup == PIPE_SEQ)
2994 /* it is "<false> && CMD" or "<true> || CMD"
2995 * and we should not execute CMD */
2999 skip_more_for_this_rword = RES_XXXX;
3002 if (rword == RES_THEN) {
3003 /* "if <false> THEN cmd": skip cmd */
3007 if (rword == RES_ELSE || rword == RES_ELIF) {
3008 /* "if <true> then ... ELSE/ELIF cmd":
3009 * skip cmd and all following ones */
3014 #if ENABLE_HUSH_LOOPS
3015 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3017 /* first loop through for */
3019 static const char encoded_dollar_at[] ALIGN1 = {
3020 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3021 }; /* encoded representation of "$@" */
3022 static const char *const encoded_dollar_at_argv[] = {
3023 encoded_dollar_at, NULL
3024 }; /* argv list with one element: "$@" */
3027 vals = (char**)encoded_dollar_at_argv;
3028 if (pi->next->res_word == RES_IN) {
3029 /* if no variable values after "in" we skip "for" */
3030 if (!pi->next->cmds[0].argv)
3032 vals = pi->next->cmds[0].argv;
3033 } /* else: "for var; do..." -> assume "$@" list */
3034 /* create list of variable values */
3035 debug_print_strings("for_list made from", vals);
3036 for_list = expand_strvec_to_strvec(vals);
3037 for_lcur = for_list;
3038 debug_print_strings("for_list", for_list);
3039 for_varname = pi->cmds[0].argv[0];
3040 pi->cmds[0].argv[0] = NULL;
3042 free(pi->cmds[0].argv[0]);
3044 /* "for" loop is over, clean up */
3048 pi->cmds[0].argv[0] = for_varname;
3051 /* insert next value from for_lcur */
3052 //TODO: does it need escaping?
3053 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3054 pi->cmds[0].assignment_cnt = 1;
3056 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
3058 if (rword == RES_DONE) {
3059 continue; /* "done" has no cmds too */
3062 #if ENABLE_HUSH_CASE
3063 if (rword == RES_CASE) {
3064 case_word = expand_strvec_to_string(pi->cmds->argv);
3067 if (rword == RES_MATCH) {
3070 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3072 /* all prev words didn't match, does this one match? */
3073 argv = pi->cmds->argv;
3075 char *pattern = expand_string_to_string(*argv);
3076 /* TODO: which FNM_xxx flags to use? */
3077 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3079 if (cond_code == 0) { /* match! we will execute this branch */
3080 free(case_word); /* make future "word)" stop */
3088 if (rword == RES_CASEI) { /* inside of a case branch */
3090 continue; /* not matched yet, skip this pipe */
3093 /* Just pressing <enter> in shell should check for jobs.
3094 * OTOH, in non-interactive shell this is useless
3095 * and only leads to extra job checks */
3096 if (pi->num_cmds == 0) {
3097 if (G_interactive_fd)
3098 goto check_jobs_and_continue;
3102 /* After analyzing all keywords and conditions, we decided
3103 * to execute this pipe. NB: have to do checkjobs(NULL)
3104 * after run_pipe() to collect any background children,
3105 * even if list execution is to be stopped. */
3106 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3109 #if ENABLE_HUSH_LOOPS
3110 G.flag_break_continue = 0;
3112 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3114 /* we only ran a builtin: rcode is already known
3115 * and we don't need to wait for anything. */
3116 check_and_run_traps(0);
3117 #if ENABLE_HUSH_LOOPS
3118 /* was it "break" or "continue"? */
3119 if (G.flag_break_continue) {
3120 smallint fbc = G.flag_break_continue;
3121 /* we might fall into outer *loop*,
3122 * don't want to break it too */
3124 G.depth_break_continue--;
3125 if (G.depth_break_continue == 0)
3126 G.flag_break_continue = 0;
3127 /* else: e.g. "continue 2" should *break* once, *then* continue */
3128 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3129 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3130 goto check_jobs_and_break;
3131 /* "continue": simulate end of loop */
3136 } else if (pi->followup == PIPE_BG) {
3137 /* what does bash do with attempts to background builtins? */
3138 /* even bash 3.2 doesn't do that well with nested bg:
3139 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3140 * I'm NOT treating inner &'s as jobs */
3141 check_and_run_traps(0);
3143 if (G.run_list_level == 1)
3146 rcode = 0; /* EXIT_SUCCESS */
3149 if (G.run_list_level == 1 && G_interactive_fd) {
3150 /* waits for completion, then fg's main shell */
3151 rcode = checkjobs_and_fg_shell(pi);
3152 check_and_run_traps(0);
3153 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3156 { /* this one just waits for completion */
3157 rcode = checkjobs(pi);
3158 check_and_run_traps(0);
3159 debug_printf_exec(": checkjobs returned %d\n", rcode);
3163 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3164 G.last_return_code = rcode;
3166 /* Analyze how result affects subsequent commands */
3168 if (rword == RES_IF || rword == RES_ELIF)
3171 #if ENABLE_HUSH_LOOPS
3172 if (rword == RES_WHILE) {
3174 rcode = 0; /* "while false; do...done" - exitcode 0 */
3175 goto check_jobs_and_break;
3178 if (rword == RES_UNTIL) {
3180 check_jobs_and_break:
3186 if ((rcode == 0 && pi->followup == PIPE_OR)
3187 || (rcode != 0 && pi->followup == PIPE_AND)
3189 skip_more_for_this_rword = rword;
3192 check_jobs_and_continue:
3197 //// if (G.ctrl_z_flag) {
3198 //// /* ctrl-Z forked somewhere in the past, we are the child,
3199 //// * and now we completed running the list. Exit. */
3205 //// if (!G.run_list_level && G_interactive_fd) {
3206 //// signal(SIGTSTP, SIG_IGN);
3207 //// signal(SIGINT, SIG_IGN);
3210 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3211 #if ENABLE_HUSH_LOOPS
3216 #if ENABLE_HUSH_CASE
3222 /* Select which version we will use */
3223 static int run_and_free_list(struct pipe *pi)
3226 debug_printf_exec("run_and_free_list entered\n");
3228 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3229 rcode = run_list(pi);
3231 /* free_pipe_list has the side effect of clearing memory.
3232 * In the long run that function can be merged with run_list,
3233 * but doing that now would hobble the debugging effort. */
3234 free_pipe_list(pi, /* indent: */ 0);
3235 debug_printf_exec("run_and_free_list return %d\n", rcode);
3240 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3241 * as in "2>&1", that represents duplicating a file descriptor.
3242 * Return either -2 (syntax error), -1 (no &), or the number found.
3244 static int redirect_dup_num(struct in_str *input)
3246 int ch, d = 0, ok = 0;
3248 if (ch != '&') return -1;
3250 i_getch(input); /* get the & */
3254 return -3; /* "-" represents "close me" */
3256 while (isdigit(ch)) {
3257 d = d*10 + (ch-'0');
3264 bb_error_msg("ambiguous redirect");
3268 /* The src parameter allows us to peek forward to a possible &n syntax
3269 * for file descriptor duplication, e.g., "2>&1".
3270 * Return code is 0 normally, 1 if a syntax error is detected in src.
3271 * Resource errors (in xmalloc) cause the process to exit */
3272 static int setup_redirect(struct parse_context *ctx,
3275 struct in_str *input)
3277 struct command *command = ctx->command;
3278 struct redir_struct *redir;
3279 struct redir_struct **redirp;
3282 /* Check for a '2>&1' type redirect */
3283 dup_num = redirect_dup_num(input);
3285 return 1; /* syntax error */
3287 /* Create a new redir_struct and drop it onto the end of the linked list */
3288 redirp = &command->redirects;
3289 while ((redir = *redirp) != NULL) {
3290 redirp = &(redir->next);
3292 *redirp = redir = xzalloc(sizeof(*redir));
3293 /* redir->next = NULL; */
3294 /* redir->rd_filename = NULL; */
3295 redir->rd_type = style;
3296 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3298 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3300 redir->dup = dup_num;
3301 if (dup_num != -1) {
3302 /* Erik had a check here that the file descriptor in question
3303 * is legit; I postpone that to "run time"
3304 * A "-" representation of "close me" shows up as a -3 here */
3305 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3307 /* We do _not_ try to open the file that src points to,
3308 * since we need to return and let src be expanded first.
3309 * Set ctx->pending_redirect, so we know what to do at the
3310 * end of the next parsed word. */
3311 ctx->pending_redirect = redir;
3317 static struct pipe *new_pipe(void)
3320 pi = xzalloc(sizeof(struct pipe));
3321 /*pi->followup = 0; - deliberately invalid value */
3322 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3326 /* Command (member of a pipe) is complete. The only possible error here
3327 * is out of memory, in which case xmalloc exits. */
3328 static int done_command(struct parse_context *ctx)
3330 /* The command is really already in the pipe structure, so
3331 * advance the pipe counter and make a new, null command. */
3332 struct pipe *pi = ctx->pipe;
3333 struct command *command = ctx->command;
3336 if (command->group == NULL
3337 && command->argv == NULL
3338 && command->redirects == NULL
3340 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3341 return pi->num_cmds;
3344 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3346 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3349 /* Only real trickiness here is that the uncommitted
3350 * command structure is not counted in pi->num_cmds. */
3351 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3352 command = &pi->cmds[pi->num_cmds];
3353 memset(command, 0, sizeof(*command));
3355 ctx->command = command;
3356 /* but ctx->pipe and ctx->list_head remain unchanged */
3358 return pi->num_cmds; /* used only for 0/nonzero check */
3361 static void done_pipe(struct parse_context *ctx, pipe_style type)
3365 debug_printf_parse("done_pipe entered, followup %d\n", type);
3366 /* Close previous command */
3367 not_null = done_command(ctx);
3368 ctx->pipe->followup = type;
3369 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3370 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3371 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3373 /* Without this check, even just <enter> on command line generates
3374 * tree of three NOPs (!). Which is harmless but annoying.
3375 * IOW: it is safe to do it unconditionally.
3376 * RES_NONE case is for "for a in; do ..." (empty IN set)
3377 * to work, possibly other cases too. */
3378 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3380 debug_printf_parse("done_pipe: adding new pipe: "
3381 "not_null:%d ctx->ctx_res_w:%d\n",
3382 not_null, ctx->ctx_res_w);
3384 ctx->pipe->next = new_p;
3386 /* RES_THEN, RES_DO etc are "sticky" -
3387 * they remain set for commands inside if/while.
3388 * This is used to control execution.
3389 * RES_FOR and RES_IN are NOT sticky (needed to support
3390 * cases where variable or value happens to match a keyword):
3392 #if ENABLE_HUSH_LOOPS
3393 if (ctx->ctx_res_w == RES_FOR
3394 || ctx->ctx_res_w == RES_IN)
3395 ctx->ctx_res_w = RES_NONE;
3397 #if ENABLE_HUSH_CASE
3398 if (ctx->ctx_res_w == RES_MATCH)
3399 ctx->ctx_res_w = RES_CASEI;
3401 ctx->command = NULL; /* trick done_command below */
3402 /* Create the memory for command, roughly:
3403 * ctx->pipe->cmds = new struct command;
3404 * ctx->command = &ctx->pipe->cmds[0];
3408 debug_printf_parse("done_pipe return\n");
3411 static void initialize_context(struct parse_context *ctx)
3413 memset(ctx, 0, sizeof(*ctx));
3414 ctx->pipe = ctx->list_head = new_pipe();
3415 /* Create the memory for command, roughly:
3416 * ctx->pipe->cmds = new struct command;
3417 * ctx->command = &ctx->pipe->cmds[0];
3423 /* If a reserved word is found and processed, parse context is modified
3424 * and 1 is returned.
3427 struct reserved_combo {
3430 unsigned char assignment_flag;
3434 FLAG_END = (1 << RES_NONE ),
3436 FLAG_IF = (1 << RES_IF ),
3437 FLAG_THEN = (1 << RES_THEN ),
3438 FLAG_ELIF = (1 << RES_ELIF ),
3439 FLAG_ELSE = (1 << RES_ELSE ),
3440 FLAG_FI = (1 << RES_FI ),
3442 #if ENABLE_HUSH_LOOPS
3443 FLAG_FOR = (1 << RES_FOR ),
3444 FLAG_WHILE = (1 << RES_WHILE),
3445 FLAG_UNTIL = (1 << RES_UNTIL),
3446 FLAG_DO = (1 << RES_DO ),
3447 FLAG_DONE = (1 << RES_DONE ),
3448 FLAG_IN = (1 << RES_IN ),
3450 #if ENABLE_HUSH_CASE
3451 FLAG_MATCH = (1 << RES_MATCH),
3452 FLAG_ESAC = (1 << RES_ESAC ),
3454 FLAG_START = (1 << RES_XXXX ),
3457 static const struct reserved_combo* match_reserved_word(o_string *word)
3459 /* Mostly a list of accepted follow-up reserved words.
3460 * FLAG_END means we are done with the sequence, and are ready
3461 * to turn the compound list into a command.
3462 * FLAG_START means the word must start a new compound list.
3464 static const struct reserved_combo reserved_list[] = {
3466 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3467 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3468 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3469 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3470 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3471 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3473 #if ENABLE_HUSH_LOOPS
3474 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3475 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3476 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3477 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3478 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3479 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3481 #if ENABLE_HUSH_CASE
3482 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3483 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3486 const struct reserved_combo *r;
3488 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3489 if (strcmp(word->data, r->literal) == 0)
3494 static int reserved_word(o_string *word, struct parse_context *ctx)
3496 #if ENABLE_HUSH_CASE
3497 static const struct reserved_combo reserved_match = {
3498 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3501 const struct reserved_combo *r;
3503 r = match_reserved_word(word);
3507 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3508 #if ENABLE_HUSH_CASE
3509 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3510 /* "case word IN ..." - IN part starts first match part */
3511 r = &reserved_match;
3514 if (r->flag == 0) { /* '!' */
3515 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3516 syntax("! ! command");
3517 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3519 ctx->ctx_inverted = 1;
3522 if (r->flag & FLAG_START) {
3523 struct parse_context *old;
3524 old = xmalloc(sizeof(*old));
3525 debug_printf_parse("push stack %p\n", old);
3526 *old = *ctx; /* physical copy */
3527 initialize_context(ctx);
3529 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3531 ctx->ctx_res_w = RES_SNTX;
3534 ctx->ctx_res_w = r->res;
3535 ctx->old_flag = r->flag;
3536 if (ctx->old_flag & FLAG_END) {
3537 struct parse_context *old;
3538 done_pipe(ctx, PIPE_SEQ);
3539 debug_printf_parse("pop stack %p\n", ctx->stack);
3541 old->command->group = ctx->list_head;
3542 old->command->grp_type = GRP_NORMAL;
3543 *ctx = *old; /* physical copy */
3546 word->o_assignment = r->assignment_flag;
3551 /* Word is complete, look at it and update parsing context.
3552 * Normal return is 0. Syntax errors return 1.
3553 * Note: on return, word is reset, but not o_free'd!
3555 static int done_word(o_string *word, struct parse_context *ctx)
3557 struct command *command = ctx->command;
3559 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3560 if (word->length == 0 && word->nonnull == 0) {
3561 debug_printf_parse("done_word return 0: true null, ignored\n");
3564 /* If this word wasn't an assignment, next ones definitely
3565 * can't be assignments. Even if they look like ones. */
3566 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3567 && word->o_assignment != WORD_IS_KEYWORD
3569 word->o_assignment = NOT_ASSIGNMENT;
3571 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3572 command->assignment_cnt++;
3573 word->o_assignment = MAYBE_ASSIGNMENT;
3576 if (ctx->pending_redirect) {
3577 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3578 * only if run as "bash", not "sh" */
3579 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3580 word->o_assignment = NOT_ASSIGNMENT;
3581 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3583 /* "{ echo foo; } echo bar" - bad */
3584 /* NB: bash allows e.g.:
3585 * if true; then { echo foo; } fi
3586 * while if false; then false; fi do break; done
3588 if (command->group) {
3590 debug_printf_parse("done_word return 1: syntax error, "
3591 "groups and arglists don't mix\n");
3595 #if ENABLE_HUSH_CASE
3596 if (ctx->ctx_dsemicolon
3597 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3599 /* already done when ctx_dsemicolon was set to 1: */
3600 /* ctx->ctx_res_w = RES_MATCH; */
3601 ctx->ctx_dsemicolon = 0;
3604 if (!command->argv /* if it's the first word... */
3605 #if ENABLE_HUSH_LOOPS
3606 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3607 && ctx->ctx_res_w != RES_IN
3610 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3611 if (reserved_word(word, ctx)) {
3613 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3614 return (ctx->ctx_res_w == RES_SNTX);
3618 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3619 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3620 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3621 /* (otherwise it's known to be not empty and is already safe) */
3623 /* exclude "$@" - it can expand to no word despite "" */
3624 char *p = word->data;
3625 while (p[0] == SPECIAL_VAR_SYMBOL
3626 && (p[1] & 0x7f) == '@'
3627 && p[2] == SPECIAL_VAR_SYMBOL
3631 if (p == word->data || p[0] != '\0') {
3632 /* saw no "$@", or not only "$@" but some
3633 * real text is there too */
3634 /* insert "empty variable" reference, this makes
3635 * e.g. "", $empty"" etc to not disappear */
3636 o_addchr(word, SPECIAL_VAR_SYMBOL);
3637 o_addchr(word, SPECIAL_VAR_SYMBOL);
3640 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3641 debug_print_strings("word appended to argv", command->argv);
3645 ctx->pending_redirect = NULL;
3647 #if ENABLE_HUSH_LOOPS
3648 /* Force FOR to have just one word (variable name) */
3649 /* NB: basically, this makes hush see "for v in ..." syntax as if
3650 * as it is "for v; in ...". FOR and IN become two pipe structs
3652 if (ctx->ctx_res_w == RES_FOR) {
3653 //TODO: check that command->argv[0] is a valid variable name!
3654 done_pipe(ctx, PIPE_SEQ);
3657 #if ENABLE_HUSH_CASE
3658 /* Force CASE to have just one word */
3659 if (ctx->ctx_res_w == RES_CASE) {
3660 done_pipe(ctx, PIPE_SEQ);
3663 debug_printf_parse("done_word return 0\n");
3667 /* If a redirect is immediately preceded by a number, that number is
3668 * supposed to tell which file descriptor to redirect. This routine
3669 * looks for such preceding numbers. In an ideal world this routine
3670 * needs to handle all the following classes of redirects...
3671 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3672 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3673 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3674 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3675 * A -1 output from this program means no valid number was found, so the
3676 * caller should use the appropriate default for this redirection.
3678 static int redirect_opt_num(o_string *o)
3684 for (num = 0; num < o->length; num++) {
3685 if (!isdigit(o->data[num])) {
3689 num = atoi(o->data);
3694 static struct pipe *parse_stream(struct in_str *input, int end_trigger);
3695 static void parse_and_run_string(const char *s);
3697 #if ENABLE_HUSH_TICK
3698 static FILE *generate_stream_from_string(const char *s)
3701 int pid, channel[2];
3704 pid = BB_MMU ? fork() : vfork();
3706 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3708 if (pid == 0) { /* child */
3709 /* Process substitution is not considered to be usual
3710 * 'command execution'.
3711 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3718 if (ENABLE_HUSH_JOB)
3719 die_sleep = 0; /* let nofork's xfuncs die */
3720 close(channel[0]); /* NB: close _first_, then move fd! */
3721 xmove_fd(channel[1], 1);
3722 /* Prevent it from trying to handle ctrl-z etc */
3723 USE_HUSH_JOB(G.run_list_level = 1;)
3725 parse_and_run_string(s);
3726 _exit(G.last_return_code);
3728 /* We re-execute after vfork on NOMMU. This makes this script safe:
3729 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3730 * huge=`cat TESTFILE` # was blocking here forever
3733 //TODO: pass non-exported variables, traps, and functions
3734 execl(CONFIG_BUSYBOX_EXEC_PATH, "hush", "-c", s, NULL);
3741 pf = fdopen(channel[0], "r");
3745 /* Return code is exit status of the process that is run. */
3746 static int process_command_subs(o_string *dest, const char *s)
3749 struct in_str pipe_str;
3752 pf = generate_stream_from_string(s);
3755 close_on_exec_on(fileno(pf));
3757 /* Now send results of command back into original context */
3758 setup_file_in_str(&pipe_str, pf);
3760 while ((ch = i_getch(&pipe_str)) != EOF) {
3766 o_addchr(dest, '\n');
3769 o_addQchr(dest, ch);
3772 debug_printf("done reading from pipe, pclose()ing\n");
3773 /* Note: we got EOF, and we just close the read end of the pipe.
3774 * We do not wait for the `cmd` child to terminate. bash and ash do.
3776 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
3777 * `false`; echo $? - bash outputs "1"
3780 debug_printf("closed FILE from child. return 0\n");
3785 static int parse_group(o_string *dest, struct parse_context *ctx,
3786 struct in_str *input, int ch)
3788 /* dest contains characters seen prior to ( or {.
3789 * Typically it's empty, but for function defs,
3790 * it contains function name (without '()'). */
3791 struct pipe *pipe_list;
3793 struct command *command = ctx->command;
3795 debug_printf_parse("parse_group entered\n");
3796 #if ENABLE_HUSH_FUNCTIONS
3797 if (ch == 'F') { /* function definition? */
3798 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3799 //command->fname = dest->data;
3800 command->grp_type = GRP_FUNCTION;
3801 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3802 memset(dest, 0, sizeof(*dest));
3805 if (command->argv /* word [word](... */
3806 || dest->length /* word(... */
3807 || dest->nonnull /* ""(... */
3810 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3816 command->grp_type = GRP_SUBSHELL;
3818 pipe_list = parse_stream(input, endch);
3819 /* empty ()/{} or parse error? */
3820 if (!pipe_list || pipe_list == ERR_PTR) {
3822 debug_printf_parse("parse_group return 1: parse_stream returned %p\n", pipe_list);
3825 command->group = pipe_list;
3826 debug_printf_parse("parse_group return 0\n");
3828 /* command remains "open", available for possible redirects */
3831 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
3832 /* Subroutines for copying $(...) and `...` things */
3833 static void add_till_backquote(o_string *dest, struct in_str *input);
3835 static void add_till_single_quote(o_string *dest, struct in_str *input)
3838 int ch = i_getch(input);
3846 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3847 static void add_till_double_quote(o_string *dest, struct in_str *input)
3850 int ch = i_getch(input);
3853 if (ch == '\\') { /* \x. Copy both chars. */
3855 ch = i_getch(input);
3861 add_till_backquote(dest, input);
3865 //if (ch == '$') ...
3868 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3870 * "Within the backquoted style of command substitution, backslash
3871 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3872 * The search for the matching backquote shall be satisfied by the first
3873 * backquote found without a preceding backslash; during this search,
3874 * if a non-escaped backquote is encountered within a shell comment,
3875 * a here-document, an embedded command substitution of the $(command)
3876 * form, or a quoted string, undefined results occur. A single-quoted
3877 * or double-quoted string that begins, but does not end, within the
3878 * "`...`" sequence produces undefined results."
3880 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3882 static void add_till_backquote(o_string *dest, struct in_str *input)
3885 int ch = i_getch(input);
3888 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3889 int ch2 = i_getch(input);
3890 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3899 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3900 * quoting and nested ()s.
3901 * "With the $(command) style of command substitution, all characters
3902 * following the open parenthesis to the matching closing parenthesis
3903 * constitute the command. Any valid shell script can be used for command,
3904 * except a script consisting solely of redirections which produces
3905 * unspecified results."
3907 * echo $(echo '(TEST)' BEST) (TEST) BEST
3908 * echo $(echo 'TEST)' BEST) TEST) BEST
3909 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3911 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
3915 int ch = i_getch(input);
3924 if (i_peek(input) == ')') {
3931 add_till_single_quote(dest, input);
3936 add_till_double_quote(dest, input);
3940 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3941 ch = i_getch(input);
3949 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
3951 /* Return code: 0 for OK, 1 for syntax error */
3952 static int handle_dollar(o_string *dest, struct in_str *input)
3955 int ch = i_peek(input); /* first character after the $ */
3956 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
3958 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3962 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3964 debug_printf_parse(": '%c'\n", ch);
3965 o_addchr(dest, ch | quote_mask);
3968 if (!isalnum(ch) && ch != '_')
3972 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3973 } else if (isdigit(ch)) {
3976 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3977 debug_printf_parse(": '%c'\n", ch);
3978 o_addchr(dest, ch | quote_mask);
3979 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3980 } else switch (ch) {
3982 case '!': /* last bg pid */
3983 case '?': /* last exit code */
3984 case '#': /* number of args */
3985 case '*': /* args */
3986 case '@': /* args */
3987 goto make_one_char_var;
3989 bool first_char, all_digits;
3991 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3993 /* XXX maybe someone will try to escape the '}' */
3998 ch = i_getch(input);
4004 /* ${#var}: length of var contents */
4006 else if (isdigit(ch)) {
4012 if (expansion < 2 &&
4013 ((all_digits && !isdigit(ch)) ||
4014 (!all_digits && !isalnum(ch) && ch != '_')))
4016 /* handle parameter expansions
4017 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4022 case ':': /* null modifier */
4023 if (expansion == 0) {
4024 debug_printf_parse(": null modifier\n");
4030 #if 0 /* not implemented yet :( */
4031 case '#': /* remove prefix */
4032 case '%': /* remove suffix */
4033 if (expansion == 0) {
4034 debug_printf_parse(": remove suffix/prefix\n");
4041 case '-': /* default value */
4042 case '=': /* assign default */
4043 case '+': /* alternative */
4044 case '?': /* error indicate */
4045 debug_printf_parse(": parameter expansion\n");
4051 syntax("unterminated ${name}");
4052 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4058 debug_printf_parse(": '%c'\n", ch);
4059 o_addchr(dest, ch | quote_mask);
4063 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4069 #if ENABLE_SH_MATH_SUPPORT
4070 if (i_peek(input) == '(') {
4072 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4073 o_addchr(dest, /*quote_mask |*/ '+');
4074 add_till_closing_paren(dest, input, true);
4075 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4080 #if ENABLE_HUSH_TICK
4081 //int pos = dest->length;
4082 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4083 o_addchr(dest, quote_mask | '`');
4084 add_till_closing_paren(dest, input, false);
4085 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4086 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4093 if (isalnum(ch)) { /* it's $_name or $_123 */
4099 /* still unhandled, but should be eventually */
4100 bb_error_msg("unhandled syntax: $%c", ch);
4104 o_addQchr(dest, '$');
4106 debug_printf_parse("handle_dollar return 0\n");
4110 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end)
4116 ch = i_getch(input);
4117 if (ch == dquote_end) { /* may be only '"' or EOF */
4119 if (dest->o_assignment == NOT_ASSIGNMENT)
4120 dest->o_escape ^= 1;
4121 debug_printf_parse("parse_stream_dquoted return 0\n");
4125 syntax("unterminated \"");
4126 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4131 next = i_peek(input);
4133 debug_printf_parse(": ch=%c (%d) m=%d escape=%d\n",
4134 ch, ch, m, dest->o_escape);
4135 /* Basically, checking every CHAR_SPECIAL char except '"' */
4139 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4143 * "The backslash retains its special meaning [in "..."]
4144 * only when followed by one of the following characters:
4145 * $, `, ", \, or <newline>. A double quote may be quoted
4146 * within double quotes by preceding it with a backslash.
4147 * If enabled, history expansion will be performed unless
4148 * an ! appearing in double quotes is escaped using
4149 * a backslash. The backslash preceding the ! is not removed."
4151 if (strchr("$`\"\\", next) != NULL) {
4152 o_addqchr(dest, i_getch(input));
4154 o_addqchr(dest, '\\');
4159 if (handle_dollar(dest, input) != 0) {
4160 debug_printf_parse("parse_stream_dquoted return 1: handle_dollar returned non-0\n");
4165 #if ENABLE_HUSH_TICK
4167 //int pos = dest->length;
4168 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4169 o_addchr(dest, 0x80 | '`');
4170 add_till_backquote(dest, input);
4171 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4172 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4176 o_addQchr(dest, ch);
4178 && (dest->o_assignment == MAYBE_ASSIGNMENT
4179 || dest->o_assignment == WORD_IS_KEYWORD)
4180 && is_assignment(dest->data)
4182 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4188 * Scan input until EOF or end_trigger char.
4189 * Return a list of pipes to execute, or NULL on EOF
4190 * or if end_trigger character is met.
4191 * On syntax error, exit is shell is not interactive,
4192 * reset parsing machinery and start parsing anew,
4193 * or return ERR_PTR.
4195 static struct pipe *parse_stream(struct in_str *input, int end_trigger)
4197 struct parse_context ctx;
4198 o_string dest = NULL_O_STRING;
4203 redir_type redir_style;
4205 /* Double-quote state is handled in the state variable is_in_dquote.
4206 * A single-quote triggers a bypass of the main loop until its mate is
4207 * found. When recursing, quote state is passed in via dest->o_escape. */
4209 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4210 end_trigger ? : 'X');
4212 G.ifs = get_local_var_value("IFS");
4217 #if ENABLE_HUSH_INTERACTIVE
4218 input->promptmode = 0; /* PS1 */
4220 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4221 initialize_context(&ctx);
4225 const char *is_special;
4228 if (parse_stream_dquoted(&dest, input, '"')) {
4231 /* We reached closing '"' */
4235 ch = i_getch(input);
4236 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4237 ch, ch, dest.o_escape);
4240 if (done_word(&dest, &ctx)) {
4244 done_pipe(&ctx, PIPE_SEQ);
4245 /* If we got nothing... */
4247 if (pi->num_cmds == 0
4248 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4250 free_pipe_list(pi, 0);
4253 debug_printf_parse("parse_stream return %p\n", pi);
4257 next = i_peek(input);
4260 is_ifs = strchr(G.ifs, ch);
4261 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4262 "\\$\"" USE_HUSH_TICK("`") /* always special */
4265 if (!is_special && !is_ifs) { /* ordinary char */
4266 o_addQchr(&dest, ch);
4267 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4268 || dest.o_assignment == WORD_IS_KEYWORD)
4270 && is_assignment(dest.data)
4272 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4278 if (done_word(&dest, &ctx)) {
4282 #if ENABLE_HUSH_CASE
4283 /* "case ... in <newline> word) ..." -
4284 * newlines are ignored (but ';' wouldn't be) */
4285 if (ctx.command->argv == NULL
4286 && ctx.ctx_res_w == RES_MATCH
4291 /* Treat newline as a command separator. */
4292 done_pipe(&ctx, PIPE_SEQ);
4293 dest.o_assignment = MAYBE_ASSIGNMENT;
4295 /* note: if (m == CHAR_IFS) continue;
4296 * will still trigger for us */
4299 if (end_trigger && end_trigger == ch) {
4300 //TODO: disallow "{ cmd }" without semicolon
4301 if (done_word(&dest, &ctx)) {
4304 done_pipe(&ctx, PIPE_SEQ);
4305 dest.o_assignment = MAYBE_ASSIGNMENT;
4306 /* Do we sit outside of any if's, loops or case's? */
4308 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4310 debug_printf_parse("parse_stream return %p: "
4311 "end_trigger char found\n",
4314 return ctx.list_head;
4320 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4321 /* ch is a special char and thus this word
4322 * cannot be an assignment */
4323 dest.o_assignment = NOT_ASSIGNMENT;
4328 if (dest.length == 0) {
4331 if (ch == EOF || ch == '\n')
4336 o_addQchr(&dest, ch);
4344 o_addchr(&dest, '\\');
4345 o_addchr(&dest, i_getch(input));
4348 if (handle_dollar(&dest, input) != 0) {
4349 debug_printf_parse("parse_stream parse error: handle_dollar returned non-0\n");
4356 ch = i_getch(input);
4358 syntax("unterminated '");
4363 if (dest.o_assignment == NOT_ASSIGNMENT)
4364 o_addqchr(&dest, ch);
4366 o_addchr(&dest, ch);
4371 is_in_dquote ^= 1; /* invert */
4372 if (dest.o_assignment == NOT_ASSIGNMENT)
4375 #if ENABLE_HUSH_TICK
4377 //int pos = dest.length;
4378 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4379 o_addchr(&dest, '`');
4380 add_till_backquote(&dest, input);
4381 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4382 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4387 redir_fd = redirect_opt_num(&dest);
4388 if (done_word(&dest, &ctx)) {
4391 redir_style = REDIRECT_OVERWRITE;
4393 redir_style = REDIRECT_APPEND;
4397 else if (next == '(') {
4398 syntax(">(process) not supported");
4402 setup_redirect(&ctx, redir_fd, redir_style, input);
4405 redir_fd = redirect_opt_num(&dest);
4406 if (done_word(&dest, &ctx)) {
4409 redir_style = REDIRECT_INPUT;
4411 redir_style = REDIRECT_HEREIS;
4413 } else if (next == '>') {
4414 redir_style = REDIRECT_IO;
4418 else if (next == '(') {
4419 syntax("<(process) not supported");
4423 setup_redirect(&ctx, redir_fd, redir_style, input);
4426 #if ENABLE_HUSH_CASE
4429 if (done_word(&dest, &ctx)) {
4432 done_pipe(&ctx, PIPE_SEQ);
4433 #if ENABLE_HUSH_CASE
4434 /* Eat multiple semicolons, detect
4435 * whether it means something special */
4441 if (ctx.ctx_res_w == RES_CASEI) {
4442 ctx.ctx_dsemicolon = 1;
4443 ctx.ctx_res_w = RES_MATCH;
4449 /* We just finished a cmd. New one may start
4450 * with an assignment */
4451 dest.o_assignment = MAYBE_ASSIGNMENT;
4454 if (done_word(&dest, &ctx)) {
4459 done_pipe(&ctx, PIPE_AND);
4461 done_pipe(&ctx, PIPE_BG);
4465 if (done_word(&dest, &ctx)) {
4468 #if ENABLE_HUSH_CASE
4469 if (ctx.ctx_res_w == RES_MATCH)
4470 break; /* we are in case's "word | word)" */
4472 if (next == '|') { /* || */
4474 done_pipe(&ctx, PIPE_OR);
4476 /* we could pick up a file descriptor choice here
4477 * with redirect_opt_num(), but bash doesn't do it.
4478 * "echo foo 2| cat" yields "foo 2". */
4483 #if ENABLE_HUSH_CASE
4484 /* "case... in [(]word)..." - skip '(' */
4485 if (ctx.ctx_res_w == RES_MATCH
4486 && ctx.command->argv == NULL /* not (word|(... */
4487 && dest.length == 0 /* not word(... */
4488 && dest.nonnull == 0 /* not ""(... */
4493 #if ENABLE_HUSH_FUNCTIONS
4494 if (dest.length != 0 /* not just () but word() */
4495 && dest.nonnull == 0 /* not a"b"c() */
4496 && ctx.command->argv == NULL /* it's the first word */
4497 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4498 && i_peek(input) == ')'
4499 && !match_reserved_word(&dest)
4501 bb_error_msg("seems like a function definition");
4504 //TODO: do it properly.
4505 ch = i_getch(input);
4506 } while (ch == ' ' || ch == '\n');
4508 syntax("was expecting {");
4511 ch = 'F'; /* magic value */
4515 if (parse_group(&dest, &ctx, input, ch) != 0) {
4520 #if ENABLE_HUSH_CASE
4521 if (ctx.ctx_res_w == RES_MATCH)
4525 /* proper use of this character is caught by end_trigger:
4526 * if we see {, we call parse_group(..., end_trigger='}')
4527 * and it will match } earlier (not here). */
4528 syntax("unexpected } or )");
4532 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4538 struct parse_context *pctx;
4539 IF_HAS_KEYWORDS(struct parse_context *p2;)
4541 /* Clean up allocated tree.
4542 * Samples for finding leaks on syntax error recovery path.
4543 * Execute them from interactive shell and watch pmap `pidof hush`.
4544 * while if false; then false; fi do break; done (bash accepts it)
4545 * while if false; then false; fi; do break; fi
4549 /* Update pipe/command counts,
4550 * otherwise freeing may miss some */
4551 done_pipe(pctx, PIPE_SEQ);
4552 debug_printf_clean("freeing list %p from ctx %p\n",
4553 pctx->list_head, pctx);
4554 debug_print_tree(pctx->list_head, 0);
4555 free_pipe_list(pctx->list_head, 0);
4556 debug_printf_clean("freed list %p\n", pctx->list_head);
4557 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4561 IF_HAS_KEYWORDS(pctx = p2;)
4562 } while (HAS_KEYWORDS && pctx);
4563 /* Free text, clear all dest fields */
4565 /* If we are not in top-level parse, we return,
4566 * our caller will propagate error.
4568 if (end_trigger != ';')
4570 /* Discard cached input, force prompt */
4572 USE_HUSH_INTERACTIVE(input->promptme = 1;)
4577 /* Execiting from string: eval, sh -c '...'
4578 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4579 * end_trigger controls how often we stop parsing
4580 * NUL: parse all, execute, return
4581 * ';': parse till ';' or newline, execute, repeat till EOF
4583 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4586 struct pipe *pipe_list;
4588 pipe_list = parse_stream(inp, end_trigger);
4589 if (!pipe_list) /* EOF */
4591 debug_print_tree(pipe_list, 0);
4592 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4593 run_and_free_list(pipe_list);
4597 static void parse_and_run_string(const char *s)
4599 struct in_str input;
4600 setup_string_in_str(&input, s);
4601 parse_and_run_stream(&input, '\0');
4604 static void parse_and_run_file(FILE *f)
4606 struct in_str input;
4607 setup_file_in_str(&input, f);
4608 parse_and_run_stream(&input, ';');
4612 /* Make sure we have a controlling tty. If we get started under a job
4613 * aware app (like bash for example), make sure we are now in charge so
4614 * we don't fight over who gets the foreground */
4615 static void setup_job_control(void)
4619 shell_pgrp = getpgrp();
4621 /* If we were ran as 'hush &',
4622 * sleep until we are in the foreground. */
4623 while (tcgetpgrp(G_interactive_fd) != shell_pgrp) {
4624 /* Send TTIN to ourself (should stop us) */
4625 kill(- shell_pgrp, SIGTTIN);
4626 shell_pgrp = getpgrp();
4629 /* We _must_ restore tty pgrp on fatal signals */
4630 set_fatal_signals_to_sigexit();
4632 /* Put ourselves in our own process group. */
4633 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4634 /* Grab control of the terminal. */
4635 tcsetpgrp(G_interactive_fd, getpid());
4639 static int set_mode(const char cstate, const char mode)
4641 int state = (cstate == '-' ? 1 : 0);
4643 case 'n': G.fake_mode = state; break;
4644 case 'x': /*G.debug_mode = state;*/ break;
4645 default: return EXIT_FAILURE;
4647 return EXIT_SUCCESS;
4650 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4651 int hush_main(int argc, char **argv)
4653 static const struct variable const_shell_ver = {
4655 .varstr = (char*)hush_version_str,
4656 .max_len = 1, /* 0 can provoke free(name) */
4664 struct variable *cur_var;
4668 G.root_pid = getpid();
4670 /* Deal with HUSH_VERSION */
4671 G.shell_ver = const_shell_ver; /* copying struct here */
4672 G.top_var = &G.shell_ver;
4673 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4674 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4675 /* Initialize our shell local variables with the values
4676 * currently living in the environment */
4677 cur_var = G.top_var;
4680 char *value = strchr(*e, '=');
4681 if (value) { /* paranoia */
4682 cur_var->next = xzalloc(sizeof(*cur_var));
4683 cur_var = cur_var->next;
4684 cur_var->varstr = *e;
4685 cur_var->max_len = strlen(*e);
4686 cur_var->flg_export = 1;
4690 debug_printf_env("putenv '%s'\n", hush_version_str);
4691 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4693 #if ENABLE_FEATURE_EDITING
4694 G.line_input_state = new_line_input_t(FOR_SHELL);
4696 /* XXX what should these be while sourcing /etc/profile? */
4697 G.global_argc = argc;
4698 G.global_argv = argv;
4699 /* Initialize some more globals to non-zero values */
4701 #if ENABLE_HUSH_INTERACTIVE
4702 if (ENABLE_FEATURE_EDITING)
4703 cmdedit_set_initial_prompt();
4707 if (EXIT_SUCCESS) /* otherwise is already done */
4708 G.last_return_code = EXIT_SUCCESS;
4710 if (argv[0] && argv[0][0] == '-') {
4711 debug_printf("sourcing /etc/profile\n");
4712 input = fopen_for_read("/etc/profile");
4713 if (input != NULL) {
4714 close_on_exec_on(fileno(input));
4715 parse_and_run_file(input);
4721 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4722 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4725 G.global_argv = argv + optind;
4726 if (!argv[optind]) {
4727 /* -c 'script' (no params): prevent empty $0 */
4728 *--G.global_argv = argv[0];
4730 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4731 G.global_argc = argc - optind;
4732 parse_and_run_string(optarg);
4735 /* Well, we cannot just declare interactiveness,
4736 * we have to have some stuff (ctty, etc) */
4737 /* G_interactive_fd++; */
4740 /* "-s" means "read from stdin", but this is how we always
4741 * operate, so simply do nothing here. */
4745 if (!set_mode('-', opt))
4749 fprintf(stderr, "Usage: sh [FILE]...\n"
4750 " or: sh -c command [args]...\n\n");
4758 /* A shell is interactive if the '-i' flag was given, or if all of
4759 * the following conditions are met:
4761 * no arguments remaining or the -s flag given
4762 * standard input is a terminal
4763 * standard output is a terminal
4764 * Refer to Posix.2, the description of the 'sh' utility. */
4765 if (argv[optind] == NULL && input == stdin
4766 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4768 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4769 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4770 if (G.saved_tty_pgrp >= 0) {
4771 /* try to dup to high fd#, >= 255 */
4772 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4773 if (G_interactive_fd < 0) {
4774 /* try to dup to any fd */
4775 G_interactive_fd = dup(STDIN_FILENO);
4776 if (G_interactive_fd < 0)
4778 G_interactive_fd = 0;
4780 // TODO: track & disallow any attempts of user
4781 // to (inadvertently) close/redirect it
4784 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4785 debug_printf("interactive_fd=%d\n", G_interactive_fd);
4786 if (G_interactive_fd) {
4787 fcntl(G_interactive_fd, F_SETFD, FD_CLOEXEC);
4788 /* Looks like they want an interactive shell */
4789 setup_job_control();
4790 /* -1 is special - makes xfuncs longjmp, not exit
4791 * (we reset die_sleep = 0 whereever we [v]fork) */
4793 if (setjmp(die_jmp)) {
4794 /* xfunc has failed! die die die */
4795 hush_exit(xfunc_error_retval);
4798 #elif ENABLE_HUSH_INTERACTIVE
4799 /* no job control compiled, only prompt/line editing */
4800 if (argv[optind] == NULL && input == stdin
4801 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4803 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4804 if (G_interactive_fd < 0) {
4805 /* try to dup to any fd */
4806 G_interactive_fd = dup(STDIN_FILENO);
4807 if (G_interactive_fd < 0)
4809 G_interactive_fd = 0;
4811 if (G_interactive_fd) {
4812 fcntl(G_interactive_fd, F_SETFD, FD_CLOEXEC);
4815 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4819 /* POSIX allows shell to re-enable SIGCHLD
4820 * even if it was SIG_IGN on entry */
4821 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4822 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4824 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4825 if (G_interactive_fd) {
4826 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4827 printf("Enter 'help' for a list of built-in commands.\n\n");
4831 if (argv[optind] == NULL) {
4832 parse_and_run_file(stdin);
4834 debug_printf("\nrunning script '%s'\n", argv[optind]);
4835 G.global_argv = argv + optind;
4836 G.global_argc = argc - optind;
4837 input = xfopen_for_read(argv[optind]);
4838 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4839 parse_and_run_file(input);
4844 #if ENABLE_FEATURE_CLEAN_UP
4846 if (G.cwd != bb_msg_unknown)
4848 cur_var = G.top_var->next;
4850 struct variable *tmp = cur_var;
4851 if (!cur_var->max_len)
4852 free(cur_var->varstr);
4853 cur_var = cur_var->next;
4857 hush_exit(G.last_return_code);
4862 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4863 int lash_main(int argc, char **argv)
4865 //bb_error_msg("lash is deprecated, please use hush instead");
4866 return hush_main(argc, argv);
4874 static int builtin_trap(char **argv)
4881 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4884 /* No args: print all trapped. This isn't 100% correct as we should
4885 * be escaping the cmd so that it can be pasted back in ...
4887 for (i = 0; i < NSIG; ++i)
4889 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4890 return EXIT_SUCCESS;
4895 /* if first arg is decimal: reset all specified */
4896 sig = bb_strtou(*++argv, NULL, 10);
4902 sig = get_signum(*argv++);
4903 if (sig < 0 || sig >= NSIG) {
4905 /* mimic bash message exactly */
4906 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4911 G.traps[sig] = xstrdup(new_cmd);
4913 debug_printf("trap: setting SIG%s (%i) to '%s'",
4914 get_signame(sig), sig, G.traps[sig]);
4916 /* There is no signal for 0 (EXIT) */
4921 sigaddset(&G.blocked_set, sig);
4923 /* there was a trap handler, we are removing it
4924 * (if sig has non-DFL handling,
4925 * we don't need to do anything) */
4926 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4928 sigdelset(&G.blocked_set, sig);
4930 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4935 /* first arg is "-": reset all specified to default */
4936 /* first arg is "": ignore all specified */
4937 /* everything else: execute first arg upon signal */
4939 bb_error_msg("trap: invalid arguments");
4940 return EXIT_FAILURE;
4942 if (LONE_DASH(*argv))
4950 static int builtin_true(char **argv UNUSED_PARAM)
4955 static int builtin_test(char **argv)
4962 return test_main(argc, argv - argc);
4965 static int builtin_echo(char **argv)
4972 return echo_main(argc, argv - argc);
4975 static int builtin_eval(char **argv)
4977 int rcode = EXIT_SUCCESS;
4980 char *str = expand_strvec_to_string(argv + 1);
4982 * eval "echo Hi; done" ("done" is syntax error):
4983 * "echo Hi" will not execute too.
4985 parse_and_run_string(str);
4987 rcode = G.last_return_code;
4992 static int builtin_cd(char **argv)
4995 if (argv[1] == NULL) {
4996 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4997 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4999 newdir = getenv("HOME") ? : "/";
5002 if (chdir(newdir)) {
5003 printf("cd: %s: %s\n", newdir, strerror(errno));
5004 return EXIT_FAILURE;
5007 return EXIT_SUCCESS;
5010 static int builtin_exec(char **argv)
5012 if (argv[1] == NULL)
5013 return EXIT_SUCCESS; /* bash does this */
5018 // FIXME: if exec fails, bash does NOT exit! We do...
5019 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
5024 static int builtin_exit(char **argv)
5026 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5027 //puts("exit"); /* bash does it */
5028 // TODO: warn if we have background jobs: "There are stopped jobs"
5029 // On second consecutive 'exit', exit anyway.
5030 if (argv[1] == NULL)
5031 hush_exit(G.last_return_code);
5032 /* mimic bash: exit 123abc == exit 255 + error msg */
5033 xfunc_error_retval = 255;
5034 /* bash: exit -2 == exit 254, no error msg */
5035 hush_exit(xatoi(argv[1]) & 0xff);
5038 static int builtin_export(char **argv)
5041 char *name = argv[1];
5045 // ash emits: export VAR='VAL'
5046 // bash: declare -x VAR="VAL"
5047 // (both also escape as needed (quotes, $, etc))
5052 return EXIT_SUCCESS;
5055 value = strchr(name, '=');
5057 /* They are exporting something without a =VALUE */
5058 struct variable *var;
5060 var = get_local_var(name);
5062 var->flg_export = 1;
5063 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5064 putenv(var->varstr);
5066 /* bash does not return an error when trying to export
5067 * an undefined variable. Do likewise. */
5068 return EXIT_SUCCESS;
5071 set_local_var(xstrdup(name), 1);
5072 return EXIT_SUCCESS;
5076 /* built-in 'fg' and 'bg' handler */
5077 static int builtin_fg_bg(char **argv)
5082 if (!G_interactive_fd)
5083 return EXIT_FAILURE;
5084 /* If they gave us no args, assume they want the last backgrounded task */
5086 for (pi = G.job_list; pi; pi = pi->next) {
5087 if (pi->jobid == G.last_jobid) {
5091 bb_error_msg("%s: no current job", argv[0]);
5092 return EXIT_FAILURE;
5094 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5095 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5096 return EXIT_FAILURE;
5098 for (pi = G.job_list; pi; pi = pi->next) {
5099 if (pi->jobid == jobnum) {
5103 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5104 return EXIT_FAILURE;
5106 // TODO: bash prints a string representation
5107 // of job being foregrounded (like "sleep 1 | cat")
5108 if (*argv[0] == 'f') {
5109 /* Put the job into the foreground. */
5110 tcsetpgrp(G_interactive_fd, pi->pgrp);
5113 /* Restart the processes in the job */
5114 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5115 for (i = 0; i < pi->num_cmds; i++) {
5116 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5117 pi->cmds[i].is_stopped = 0;
5119 pi->stopped_cmds = 0;
5121 i = kill(- pi->pgrp, SIGCONT);
5123 if (errno == ESRCH) {
5124 delete_finished_bg_job(pi);
5125 return EXIT_SUCCESS;
5127 bb_perror_msg("kill (SIGCONT)");
5131 if (*argv[0] == 'f') {
5133 return checkjobs_and_fg_shell(pi);
5135 return EXIT_SUCCESS;
5139 #if ENABLE_HUSH_HELP
5140 static int builtin_help(char **argv UNUSED_PARAM)
5142 const struct built_in_command *x;
5144 printf("\nBuilt-in commands:\n");
5145 printf("-------------------\n");
5146 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5147 printf("%s\t%s\n", x->cmd, x->descr);
5150 return EXIT_SUCCESS;
5155 static int builtin_jobs(char **argv UNUSED_PARAM)
5158 const char *status_string;
5160 for (job = G.job_list; job; job = job->next) {
5161 if (job->alive_cmds == job->stopped_cmds)
5162 status_string = "Stopped";
5164 status_string = "Running";
5166 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5168 return EXIT_SUCCESS;
5172 static int builtin_pwd(char **argv UNUSED_PARAM)
5175 return EXIT_SUCCESS;
5178 static int builtin_read(char **argv)
5181 const char *name = argv[1] ? argv[1] : "REPLY";
5183 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5184 return set_local_var(string, 0);
5187 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5188 * built-in 'set' handler
5190 * set [-abCefhmnuvx] [-o option] [argument...]
5191 * set [+abCefhmnuvx] [+o option] [argument...]
5192 * set -- [argument...]
5195 * Implementations shall support the options in both their hyphen and
5196 * plus-sign forms. These options can also be specified as options to sh.
5198 * Write out all variables and their values: set
5199 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5200 * Turn on the -x and -v options: set -xv
5201 * Unset all positional parameters: set --
5202 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5203 * Set the positional parameters to the expansion of x, even if x expands
5204 * with a leading '-' or '+': set -- $x
5206 * So far, we only support "set -- [argument...]" and some of the short names.
5208 static int builtin_set(char **argv)
5211 char **pp, **g_argv;
5212 char *arg = *++argv;
5216 for (e = G.top_var; e; e = e->next)
5218 return EXIT_SUCCESS;
5222 if (!strcmp(arg, "--")) {
5227 if (arg[0] == '+' || arg[0] == '-') {
5228 for (n = 1; arg[n]; ++n)
5229 if (set_mode(arg[0], arg[n]))
5235 } while ((arg = *++argv) != NULL);
5236 /* Now argv[0] is 1st argument */
5238 /* Only reset global_argv if we didn't process anything */
5240 return EXIT_SUCCESS;
5243 /* NB: G.global_argv[0] ($0) is never freed/changed */
5244 g_argv = G.global_argv;
5245 if (G.global_args_malloced) {
5251 G.global_args_malloced = 1;
5252 pp = xzalloc(sizeof(pp[0]) * 2);
5253 pp[0] = g_argv[0]; /* retain $0 */
5256 /* This realloc's G.global_argv */
5257 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5264 return EXIT_SUCCESS;
5266 /* Nothing known, so abort */
5268 bb_error_msg("set: %s: invalid option", arg);
5269 return EXIT_FAILURE;
5272 static int builtin_shift(char **argv)
5278 if (n >= 0 && n < G.global_argc) {
5279 if (G.global_args_malloced) {
5282 free(G.global_argv[m++]);
5285 memmove(&G.global_argv[1], &G.global_argv[n+1],
5286 G.global_argc * sizeof(G.global_argv[0]));
5287 return EXIT_SUCCESS;
5289 return EXIT_FAILURE;
5292 static int builtin_source(char **argv)
5296 if (argv[1] == NULL)
5297 return EXIT_FAILURE;
5299 /* XXX search through $PATH is missing */
5300 input = fopen_for_read(argv[1]);
5302 bb_error_msg("can't open '%s'", argv[1]);
5303 return EXIT_FAILURE;
5305 close_on_exec_on(fileno(input));
5307 /* Now run the file */
5308 /* XXX argv and argc are broken; need to save old G.global_argv
5309 * (pointer only is OK!) on this stack frame,
5310 * set G.global_argv=argv+1, recurse, and restore. */
5311 parse_and_run_file(input);
5313 return G.last_return_code;
5316 static int builtin_umask(char **argv)
5319 const char *arg = argv[1];
5321 new_umask = bb_strtou(arg, NULL, 8);
5323 return EXIT_FAILURE;
5325 new_umask = umask(0);
5326 printf("%.3o\n", (unsigned) new_umask);
5329 return EXIT_SUCCESS;
5332 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5333 static int builtin_unset(char **argv)
5340 return EXIT_SUCCESS;
5343 if (argv[1][0] == '-') {
5344 switch (argv[1][1]) {
5346 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5348 bb_error_msg("unset: %s: invalid option", argv[1]);
5349 return EXIT_FAILURE;
5357 if (unset_local_var(argv[i]))
5360 #if ENABLE_HUSH_FUNCTIONS
5362 unset_local_func(argv[i]);
5368 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5369 static int builtin_wait(char **argv)
5371 int ret = EXIT_SUCCESS;
5374 if (*++argv == NULL) {
5375 /* Don't care about wait results */
5376 /* Note 1: must wait until there are no more children */
5377 /* Note 2: must be interruptible */
5379 * $ sleep 3 & sleep 6 & wait
5384 * $ sleep 3 & sleep 6 & wait
5388 * ^C <-- after ~4 sec from keyboard
5391 sigaddset(&G.blocked_set, SIGCHLD);
5392 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5395 if (errno == ECHILD)
5397 /* Wait for SIGCHLD or any other signal of interest */
5398 /* sigtimedwait with infinite timeout: */
5399 sig = sigwaitinfo(&G.blocked_set, NULL);
5401 sig = check_and_run_traps(sig);
5402 if (sig && sig != SIGCHLD) { /* see note 2 */
5408 sigdelset(&G.blocked_set, SIGCHLD);
5409 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5413 /* This is probably buggy wrt interruptible-ness */
5415 pid_t pid = bb_strtou(*argv, NULL, 10);
5417 /* mimic bash message */
5418 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5419 return EXIT_FAILURE;
5421 if (waitpid(pid, &status, 0) == pid) {
5422 if (WIFSIGNALED(status))
5423 ret = 128 + WTERMSIG(status);
5424 else if (WIFEXITED(status))
5425 ret = WEXITSTATUS(status);
5429 bb_perror_msg("wait %s", *argv);
5438 #if ENABLE_HUSH_LOOPS
5439 static int builtin_break(char **argv)
5441 if (G.depth_of_loop == 0) {
5442 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5443 return EXIT_SUCCESS; /* bash compat */
5445 G.flag_break_continue++; /* BC_BREAK = 1 */
5446 G.depth_break_continue = 1;
5448 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5449 if (errno || !G.depth_break_continue || argv[2]) {
5450 bb_error_msg("%s: bad arguments", argv[0]);
5451 G.flag_break_continue = BC_BREAK;
5452 G.depth_break_continue = UINT_MAX;
5455 if (G.depth_of_loop < G.depth_break_continue)
5456 G.depth_break_continue = G.depth_of_loop;
5457 return EXIT_SUCCESS;
5460 static int builtin_continue(char **argv)
5462 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5463 return builtin_break(argv);