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>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr() derived from similar w_addchar function in glibc-2.2.
25 * setup_redirect(), redirect_opt_num(), and big chunks of main()
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
43 * Here Documents ( << word )
46 * Parameter Expansion for substring processing ${var#word} ${var%word}
48 * Bash stuff (maybe optionally enable?):
49 * &> and >& redirection of stdout+stderr
51 * reserved words: [[ ]] function select
52 * substrings ${var:1:5}
55 * grep for "TODO" and fix (some of them are easy)
56 * change { and } from special chars to reserved words
57 * builtins: return, ulimit
58 * follow IFS rules more precisely, including update semantics
59 * figure out what to do with backslash-newline
60 * continuation lines, both explicit and implicit - done?
62 * ^Z handling (and explain it in comments for mere humans)
63 * separate job control from interactiveness
64 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
67 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
70 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
71 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
72 //#include "applet_tables.h" doesn't work
74 /* #include <dmalloc.h> */
80 #ifdef WANT_TO_TEST_NOMMU
85 # define USE_FOR_NOMMU(...) __VA_ARGS__
86 # define USE_FOR_MMU(...)
89 #if defined SINGLE_APPLET_MAIN
90 /* STANDALONE does not make sense, and won't compile */
91 #undef CONFIG_FEATURE_SH_STANDALONE
92 #undef ENABLE_FEATURE_SH_STANDALONE
93 #undef USE_FEATURE_SH_STANDALONE
94 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
95 #define ENABLE_FEATURE_SH_STANDALONE 0
96 #define USE_FEATURE_SH_STANDALONE(...)
97 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
100 #if !ENABLE_HUSH_INTERACTIVE
101 #undef ENABLE_FEATURE_EDITING
102 #define ENABLE_FEATURE_EDITING 0
103 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
104 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
107 /* Do we support ANY keywords? */
108 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
109 #define HAS_KEYWORDS 1
110 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
111 #define IF_HAS_NO_KEYWORDS(...)
113 #define HAS_KEYWORDS 0
114 #define IF_HAS_KEYWORDS(...)
115 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
118 /* Keep unconditionally on for now */
121 #define ENABLE_HUSH_FUNCTIONS 0
124 /* If you comment out one of these below, it will be #defined later
125 * to perform debug printfs to stderr: */
126 #define debug_printf(...) do {} while (0)
127 /* Finer-grained debug switches */
128 #define debug_printf_parse(...) do {} while (0)
129 #define debug_print_tree(a, b) do {} while (0)
130 #define debug_printf_exec(...) do {} while (0)
131 #define debug_printf_env(...) do {} while (0)
132 #define debug_printf_jobs(...) do {} while (0)
133 #define debug_printf_expand(...) do {} while (0)
134 #define debug_printf_glob(...) do {} while (0)
135 #define debug_printf_list(...) do {} while (0)
136 #define debug_printf_subst(...) do {} while (0)
137 #define debug_printf_clean(...) do {} while (0)
140 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
143 #ifndef debug_printf_parse
144 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
147 #ifndef debug_printf_exec
148 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
151 #ifndef debug_printf_env
152 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
155 #ifndef debug_printf_jobs
156 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
162 #ifndef debug_printf_expand
163 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
164 #define DEBUG_EXPAND 1
166 #define DEBUG_EXPAND 0
169 #ifndef debug_printf_glob
170 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
176 #ifndef debug_printf_list
177 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
180 #ifndef debug_printf_subst
181 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
184 #ifndef debug_printf_clean
185 /* broken, of course, but OK for testing */
186 static const char *indenter(int i)
188 static const char blanks[] ALIGN1 =
190 return &blanks[sizeof(blanks) - i - 1];
192 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
193 #define DEBUG_CLEAN 1
195 #define DEBUG_CLEAN 0
199 static void debug_print_strings(const char *prefix, char **vv)
201 fprintf(stderr, "%s:\n", prefix);
203 fprintf(stderr, " '%s'\n", *vv++);
206 #define debug_print_strings(prefix, vv) ((void)0)
210 * Leak hunting. Use hush_leaktool.sh for post-processing.
212 #ifdef FOR_HUSH_LEAKTOOL
213 static void *xxmalloc(int lineno, size_t size)
215 void *ptr = xmalloc((size + 0xff) & ~0xff);
216 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
219 static void *xxrealloc(int lineno, void *ptr, size_t size)
221 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
222 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
225 static char *xxstrdup(int lineno, const char *str)
227 char *ptr = xstrdup(str);
228 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
231 static void xxfree(void *ptr)
233 fdprintf(2, "free %p\n", ptr);
236 #define xmalloc(s) xxmalloc(__LINE__, s)
237 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
238 #define xstrdup(s) xxstrdup(__LINE__, s)
239 #define free(p) xxfree(p)
243 #define ERR_PTR ((void*)(long)1)
245 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
247 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
249 #define SPECIAL_VAR_SYMBOL 3
251 typedef enum redir_type {
253 REDIRECT_OVERWRITE = 2,
259 /* The descrip member of this structure is only used to make
260 * debugging output pretty */
261 static const struct {
263 signed char default_fd;
267 { O_RDONLY, 0, "<" },
268 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
269 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
270 { O_RDONLY, -1, "<<" },
274 typedef enum reserved_style {
283 #if ENABLE_HUSH_LOOPS
290 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
295 /* two pseudo-keywords support contrived "case" syntax: */
296 RES_MATCH , /* "word)" */
297 RES_CASEI , /* "this command is inside CASE" */
304 typedef struct o_string {
306 int length; /* position where data is appended */
308 /* Protect newly added chars against globbing
309 * (by prepending \ to *, ?, [, \) */
313 smallint has_empty_slot;
314 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
317 MAYBE_ASSIGNMENT = 0,
318 DEFINITELY_ASSIGNMENT = 1,
320 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
322 /* Used for initialization: o_string foo = NULL_O_STRING; */
323 #define NULL_O_STRING { NULL }
325 /* I can almost use ordinary FILE*. Is open_memstream() universally
326 * available? Where is it documented? */
327 typedef struct in_str {
329 /* eof_flag=1: last char in ->p is really an EOF */
330 char eof_flag; /* meaningless if ->p == NULL */
332 #if ENABLE_HUSH_INTERACTIVE
334 smallint promptmode; /* 0: PS1, 1: PS2 */
337 int (*get) (struct in_str *);
338 int (*peek) (struct in_str *);
340 #define i_getch(input) ((input)->get(input))
341 #define i_peek(input) ((input)->peek(input))
343 struct redir_struct {
344 struct redir_struct *next;
345 char *rd_filename; /* filename */
346 int fd; /* file descriptor being redirected */
347 int dup; /* -1, or file descriptor being duplicated */
348 smallint /*enum redir_type*/ rd_type;
352 pid_t pid; /* 0 if exited */
353 int assignment_cnt; /* how many argv[i] are assignments? */
354 smallint is_stopped; /* is the command currently running? */
355 smallint grp_type; /* GRP_xxx */
356 struct pipe *group; /* if non-NULL, this "command" is { list },
357 * ( list ), or a compound statement */
359 char *group_as_string;
361 char **argv; /* command name and arguments */
362 struct redir_struct *redirects; /* I/O redirections */
364 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
365 * and on execution these are substituted with their values.
366 * Substitution can make _several_ words out of one argv[n]!
367 * Example: argv[0]=='.^C*^C.' here: echo .$*.
368 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
371 #define GRP_SUBSHELL 1
372 #if ENABLE_HUSH_FUNCTIONS
373 #define GRP_FUNCTION 2
378 int num_cmds; /* total number of commands in job */
379 int alive_cmds; /* number of commands running (not exited) */
380 int stopped_cmds; /* number of commands alive, but stopped */
382 int jobid; /* job number */
383 pid_t pgrp; /* process group ID for the job */
384 char *cmdtext; /* name of job */
386 struct command *cmds; /* array of commands in pipe */
387 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
388 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
389 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
391 typedef enum pipe_style {
398 /* This holds pointers to the various results of parsing */
399 struct parse_context {
400 /* linked list of pipes */
401 struct pipe *list_head;
402 /* last pipe (being constructed right now) */
404 /* last command in pipe (being constructed right now) */
405 struct command *command;
406 /* last redirect in command->redirects list */
407 struct redir_struct *pending_redirect;
413 smallint ctx_inverted; /* "! cmd | cmd" */
415 smallint ctx_dsemicolon; /* ";;" seen */
417 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
419 /* group we are enclosed in:
420 * example: "if pipe1; pipe2; then pipe3; fi"
421 * when we see "if" or "then", we malloc and copy current context,
422 * and make ->stack point to it. then we parse pipeN.
423 * when closing "then" / fi" / whatever is found,
424 * we move list_head into ->stack->command->group,
425 * copy ->stack into current context, and delete ->stack.
426 * (parsing of { list } and ( list ) doesn't use this method)
428 struct parse_context *stack;
432 /* On program start, environ points to initial environment.
433 * putenv adds new pointers into it, unsetenv removes them.
434 * Neither of these (de)allocates the strings.
435 * setenv allocates new strings in malloc space and does putenv,
436 * and thus setenv is unusable (leaky) for shell's purposes */
437 #define setenv(...) setenv_is_leaky_dont_use()
439 struct variable *next;
440 char *varstr; /* points to "name=" portion */
441 int max_len; /* if > 0, name is part of initial env; else name is malloced */
442 smallint flg_export; /* putenv should be done on this var */
443 smallint flg_read_only;
452 /* "Globals" within this file */
453 /* Sorted roughly by size (smaller offsets == smaller code) */
455 #if ENABLE_HUSH_INTERACTIVE
456 /* 'interactive_fd' is a fd# open to ctty, if we have one
457 * _AND_ if we decided to act interactively */
461 #define G_interactive_fd (G.interactive_fd)
463 #define G_interactive_fd 0
465 #if ENABLE_FEATURE_EDITING
466 line_input_t *line_input_state;
472 pid_t saved_tty_pgrp;
474 struct pipe *job_list;
475 struct pipe *toplevel_list;
476 //// smallint ctrl_z_flag;
478 smallint flag_SIGINT;
479 #if ENABLE_HUSH_LOOPS
480 smallint flag_break_continue;
483 /* These four support $?, $#, and $1 */
484 smalluint last_return_code;
485 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
486 smalluint global_args_malloced;
487 /* how many non-NULL argv's we have. NB: $# + 1 */
491 char *argv0_for_re_execing;
492 char **argv_from_re_execing;
494 #if ENABLE_HUSH_LOOPS
495 unsigned depth_break_continue;
496 unsigned depth_of_loop;
500 struct variable *top_var; /* = &G.shell_ver (set in main()) */
501 struct variable shell_ver;
502 /* Signal and trap handling */
503 // unsigned count_SIGCHLD;
504 // unsigned handled_SIGCHLD;
505 /* which signals have non-DFL handler (even with no traps set)? */
506 unsigned non_DFL_mask;
507 char **traps; /* char *traps[NSIG] */
508 sigset_t blocked_set;
509 sigset_t inherited_set;
510 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
511 #if ENABLE_FEATURE_SH_STANDALONE
512 struct nofork_save_area nofork_save;
515 sigjmp_buf toplevel_jb;
518 #define G (*ptr_to_globals)
519 /* Not #defining name to G.name - this quickly gets unwieldy
520 * (too many defines). Also, I actually prefer to see when a variable
521 * is global, thus "G." prefix is a useful hint */
522 #define INIT_G() do { \
523 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
527 /* Function prototypes for builtins */
528 static int builtin_cd(char **argv);
529 static int builtin_echo(char **argv);
530 static int builtin_eval(char **argv);
531 static int builtin_exec(char **argv);
532 static int builtin_exit(char **argv);
533 static int builtin_export(char **argv);
535 static int builtin_fg_bg(char **argv);
536 static int builtin_jobs(char **argv);
539 static int builtin_help(char **argv);
541 static int builtin_pwd(char **argv);
542 static int builtin_read(char **argv);
543 static int builtin_test(char **argv);
544 static int builtin_trap(char **argv);
545 static int builtin_true(char **argv);
546 static int builtin_set(char **argv);
547 static int builtin_shift(char **argv);
548 static int builtin_source(char **argv);
549 static int builtin_umask(char **argv);
550 static int builtin_unset(char **argv);
551 static int builtin_wait(char **argv);
552 #if ENABLE_HUSH_LOOPS
553 static int builtin_break(char **argv);
554 static int builtin_continue(char **argv);
557 /* Table of built-in functions. They can be forked or not, depending on
558 * context: within pipes, they fork. As simple commands, they do not.
559 * When used in non-forking context, they can change global variables
560 * in the parent shell process. If forked, of course they cannot.
561 * For example, 'unset foo | whatever' will parse and run, but foo will
562 * still be set at the end. */
563 struct built_in_command {
565 int (*function)(char **argv);
568 #define BLTIN(cmd, func, help) { cmd, func, help }
570 #define BLTIN(cmd, func, help) { cmd, func }
574 /* For now, echo and test are unconditionally enabled.
575 * Maybe make it configurable? */
576 static const struct built_in_command bltins[] = {
577 BLTIN("." , builtin_source , "Run commands in a file"),
578 BLTIN(":" , builtin_true , "No-op"),
579 BLTIN("[" , builtin_test , "Test condition"),
581 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
583 #if ENABLE_HUSH_LOOPS
584 BLTIN("break" , builtin_break , "Exit from a loop"),
586 BLTIN("cd" , builtin_cd , "Change directory"),
587 #if ENABLE_HUSH_LOOPS
588 BLTIN("continue", builtin_continue, "Start new loop iteration"),
590 BLTIN("echo" , builtin_echo , "Write to stdout"),
591 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
592 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
593 BLTIN("exit" , builtin_exit , "Exit"),
594 BLTIN("export" , builtin_export , "Set environment variable"),
596 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
599 BLTIN("help" , builtin_help , "List shell built-in commands"),
602 BLTIN("jobs" , builtin_jobs , "List active jobs"),
604 BLTIN("pwd" , builtin_pwd , "Print current directory"),
605 BLTIN("read" , builtin_read , "Input environment variable"),
606 // BLTIN("return" , builtin_return , "Return from a function"),
607 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
608 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
609 BLTIN("test" , builtin_test , "Test condition"),
610 BLTIN("trap" , builtin_trap , "Trap signals"),
611 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
612 BLTIN("umask" , builtin_umask , "Set file creation mask"),
613 BLTIN("unset" , builtin_unset , "Unset environment variable"),
614 BLTIN("wait" , builtin_wait , "Wait for process"),
618 static void maybe_die(const char *notice, const char *msg)
620 /* Was using fancy stuff:
621 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
622 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
623 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
624 #if ENABLE_HUSH_INTERACTIVE
625 if (G_interactive_fd)
628 fp(msg ? "%s: %s" : notice, notice, msg);
631 #define syntax(msg) maybe_die("syntax error", msg);
633 /* Debug -- trick gcc to expand __LINE__ and convert to string */
634 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
635 #define _syntax(msg, line) __syntax(msg, line)
636 #define syntax(msg) _syntax(msg, __LINE__)
640 static int glob_needed(const char *s)
645 if (*s == '*' || *s == '[' || *s == '?')
652 static int is_assignment(const char *s)
654 if (!s || !(isalpha(*s) || *s == '_'))
657 while (isalnum(*s) || *s == '_')
662 /* Replace each \x with x in place, return ptr past NUL. */
663 static char *unbackslash(char *src)
669 if ((*dst++ = *src++) == '\0')
675 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
696 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
697 v[count1 + count2] = NULL;
700 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
704 static char **add_string_to_strings(char **strings, char *add)
709 return add_strings_to_strings(strings, v, /*dup:*/ 0);
712 static void putenv_all(char **strings)
717 debug_printf_env("putenv '%s'\n", *strings);
722 static char **putenv_all_and_save_old(char **strings)
732 eq = strchr(*strings, '=');
735 v = getenv(*strings);
738 /* v points to VAL in VAR=VAL, go back to VAR */
739 v -= (eq - *strings) + 1;
740 old = add_string_to_strings(old, v);
749 static void free_strings_and_unsetenv(char **strings, int unset)
759 debug_printf_env("unsetenv '%s'\n", *v);
767 static void free_strings(char **strings)
769 free_strings_and_unsetenv(strings, 0);
773 /* Basic theory of signal handling in shell
774 * ========================================
775 * This does not describe what hush does, rather, it is current understanding
776 * what it _should_ do. If it doesn't, it's a bug.
777 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
779 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
780 * is finished or backgrounded. It is the same in interactive and
781 * non-interactive shells, and is the same regardless of whether
782 * a user trap handler is installed or a shell special one is in effect.
783 * ^C or ^Z from keyboard seem to execute "at once" because it usually
784 * backgrounds (i.e. stops) or kills all members of currently running
787 * Wait builtin in interruptible by signals for which user trap is set
788 * or by SIGINT in interactive shell.
790 * Trap handlers will execute even within trap handlers. (right?)
792 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
794 * If job control is off, backgrounded commands ("cmd &")
795 * have SIGINT, SIGQUIT set to SIG_IGN.
797 * Commands run in command substitution ("`cmd`")
798 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
800 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
801 * by the shell from its parent.
803 * Siganls which differ from SIG_DFL action
804 * (note: child (i.e., [v]forked) shell is not an interactive shell):
807 * SIGTERM (interactive): ignore
808 * SIGHUP (interactive):
809 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
810 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
811 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
812 * that all pipe members are stopped) (right?)
813 * SIGINT (interactive): wait for last pipe, ignore the rest
814 * of the command line, show prompt. NB: ^C does not send SIGINT
815 * to interactive shell while shell is waiting for a pipe,
816 * since shell is bg'ed (is not in foreground process group).
817 * (check/expand this)
818 * Example 1: this waits 5 sec, but does not execute ls:
819 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
820 * Example 2: this does not wait and does not execute ls:
821 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
822 * Example 3: this does not wait 5 sec, but executes ls:
823 * "sleep 5; ls -l" + press ^C
825 * (What happens to signals which are IGN on shell start?)
826 * (What happens with signal mask on shell start?)
828 * Implementation in hush
829 * ======================
830 * We use in-kernel pending signal mask to determine which signals were sent.
831 * We block all signals which we don't want to take action immediately,
832 * i.e. we block all signals which need to have special handling as described
833 * above, and all signals which have traps set.
834 * After each pipe execution, we extract any pending signals via sigtimedwait()
837 * unsigned non_DFL_mask: a mask of such "special" signals
838 * sigset_t blocked_set: current blocked signal set
841 * clear bit in blocked_set unless it is also in non_DFL_mask
842 * "trap 'cmd' SIGxxx":
843 * set bit in blocked_set (even if 'cmd' is '')
844 * after [v]fork, if we plan to be a shell:
845 * nothing for {} child shell (say, "true | { true; true; } | true")
846 * unset all traps if () shell. [TODO]
847 * after [v]fork, if we plan to exec:
848 * POSIX says pending signal mask is cleared in child - no need to clear it.
849 * Restore blocked signal set to one inherited by shell just prior to exec.
851 * Note: as a result, we do not use signal handlers much. The only uses
852 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
853 * and to restore tty pgrp on signal-induced exit.
856 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
858 // G.count_SIGCHLD++;
861 static int check_and_run_traps(int sig)
863 static const struct timespec zero_timespec = { 0, 0 };
864 smalluint save_rcode;
870 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
875 if (G.traps && G.traps[sig]) {
876 if (G.traps[sig][0]) {
877 /* We have user-defined handler */
878 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
879 save_rcode = G.last_return_code;
882 G.last_return_code = save_rcode;
883 } /* else: "" trap, ignoring signal */
886 /* not a trap: special action */
889 // G.count_SIGCHLD++;
898 default: /* ignored: */
899 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
907 /* Restores tty foreground process group, and exits.
908 * May be called as signal handler for fatal signal
909 * (will faithfully resend signal to itself, producing correct exit state)
910 * or called directly with -EXITCODE.
911 * We also call it if xfunc is exiting. */
912 static void sigexit(int sig) NORETURN;
913 static void sigexit(int sig)
915 /* Disable all signals: job control, SIGPIPE, etc. */
916 sigprocmask_allsigs(SIG_BLOCK);
918 /* Careful: we can end up here after [v]fork. Do not restore
919 * tty pgrp then, only top-level shell process does that */
920 if (G_interactive_fd && getpid() == G.root_pid)
921 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
923 /* Not a signal, just exit */
927 kill_myself_with_sig(sig); /* does not return */
931 /* Restores tty foreground process group, and exits. */
932 static void hush_exit(int exitcode) NORETURN;
933 static void hush_exit(int exitcode)
935 if (G.traps && G.traps[0] && G.traps[0][0]) {
936 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
937 //TODO: do we need to prevent recursion?
943 fflush(NULL); /* flush all streams */
944 sigexit(- (exitcode & 0xff));
951 static const char *set_cwd(void)
953 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
954 * we must not try to free(bb_msg_unknown) */
955 if (G.cwd == bb_msg_unknown)
957 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
959 G.cwd = bb_msg_unknown;
964 /* Get/check local shell variables */
965 static struct variable *get_local_var(const char *name)
967 struct variable *cur;
973 for (cur = G.top_var; cur; cur = cur->next) {
974 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
980 static const char *get_local_var_value(const char *src)
982 struct variable *var = get_local_var(src);
984 return strchr(var->varstr, '=') + 1;
988 /* str holds "NAME=VAL" and is expected to be malloced.
989 * We take ownership of it.
993 * -1: if NAME is set, leave export status alone
994 * if NAME is not set, do not export
995 * flg_read_only is set only when we handle -R var=val
998 #define set_local_var(str, flg_export, flg_read_only) \
999 set_local_var(str, flg_export)
1001 static int set_local_var(char *str, int flg_export, int flg_read_only)
1003 struct variable *cur;
1007 value = strchr(str, '=');
1008 if (!value) { /* not expected to ever happen? */
1013 name_len = value - str + 1; /* including '=' */
1014 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1016 if (strncmp(cur->varstr, str, name_len) != 0) {
1018 /* Bail out. Note that now cur points
1019 * to last var in linked list */
1025 /* We found an existing var with this name */
1027 if (cur->flg_read_only) {
1031 bb_error_msg("%s: readonly variable", str);
1035 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1036 unsetenv(str); /* just in case */
1038 if (strcmp(cur->varstr, str) == 0) {
1043 if (cur->max_len >= strlen(str)) {
1044 /* This one is from startup env, reuse space */
1045 strcpy(cur->varstr, str);
1048 /* max_len == 0 signifies "malloced" var, which we can
1049 * (and has to) free */
1053 goto set_str_and_exp;
1056 /* Not found - create next variable struct */
1057 cur->next = xzalloc(sizeof(*cur));
1063 cur->flg_read_only = flg_read_only;
1066 if (flg_export == 1)
1067 cur->flg_export = 1;
1068 if (cur->flg_export) {
1069 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1070 return putenv(cur->varstr);
1075 static int unset_local_var(const char *name)
1077 struct variable *cur;
1078 struct variable *prev = prev; /* for gcc */
1082 return EXIT_SUCCESS;
1083 name_len = strlen(name);
1086 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1087 if (cur->flg_read_only) {
1088 bb_error_msg("%s: readonly variable", name);
1089 return EXIT_FAILURE;
1091 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1092 * is ro, and we cannot reach this code on the 1st pass */
1093 prev->next = cur->next;
1094 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1095 bb_unsetenv(cur->varstr);
1099 return EXIT_SUCCESS;
1104 return EXIT_SUCCESS;
1107 #if ENABLE_SH_MATH_SUPPORT
1108 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1109 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1110 static char *endofname(const char *name)
1118 if (!is_in_name(*p))
1124 static void arith_set_local_var(const char *name, const char *val, int flags)
1126 /* arith code doesnt malloc space, so do it for it */
1127 char *var = xasprintf("%s=%s", name, val);
1128 set_local_var(var, flags, 0);
1136 static int static_get(struct in_str *i)
1145 static int static_peek(struct in_str *i)
1150 #if ENABLE_HUSH_INTERACTIVE
1152 static void cmdedit_set_initial_prompt(void)
1154 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1155 G.PS1 = getenv("PS1");
1162 static const char* setup_prompt_string(int promptmode)
1164 const char *prompt_str;
1165 debug_printf("setup_prompt_string %d ", promptmode);
1166 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1167 /* Set up the prompt */
1168 if (promptmode == 0) { /* PS1 */
1170 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1175 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1176 debug_printf("result '%s'\n", prompt_str);
1180 static void get_user_input(struct in_str *i)
1183 const char *prompt_str;
1185 prompt_str = setup_prompt_string(i->promptmode);
1186 #if ENABLE_FEATURE_EDITING
1187 /* Enable command line editing only while a command line
1188 * is actually being read */
1191 /* buglet: SIGINT will not make new prompt to appear _at once_,
1192 * only after <Enter>. (^C will work) */
1193 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1194 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1195 check_and_run_traps(0);
1196 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1197 i->eof_flag = (r < 0);
1198 if (i->eof_flag) { /* EOF/error detected */
1199 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1200 G.user_input_buf[1] = '\0';
1205 fputs(prompt_str, stdout);
1207 G.user_input_buf[0] = r = fgetc(i->file);
1208 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1209 //do we need check_and_run_traps(0)? (maybe only if stdin)
1210 } while (G.flag_SIGINT);
1211 i->eof_flag = (r == EOF);
1213 i->p = G.user_input_buf;
1216 #endif /* INTERACTIVE */
1218 /* This is the magic location that prints prompts
1219 * and gets data back from the user */
1220 static int file_get(struct in_str *i)
1224 /* If there is data waiting, eat it up */
1225 if (i->p && *i->p) {
1226 #if ENABLE_HUSH_INTERACTIVE
1230 if (i->eof_flag && !*i->p)
1232 /* note: ch is never NUL */
1234 /* need to double check i->file because we might be doing something
1235 * more complicated by now, like sourcing or substituting. */
1236 #if ENABLE_HUSH_INTERACTIVE
1237 if (G_interactive_fd && i->promptme && i->file == stdin) {
1240 } while (!*i->p); /* need non-empty line */
1241 i->promptmode = 1; /* PS2 */
1246 do ch = fgetc(i->file); while (ch == '\0');
1248 debug_printf("file_get: got '%c' %d\n", ch, ch);
1249 #if ENABLE_HUSH_INTERACTIVE
1256 /* All callers guarantee this routine will never
1257 * be used right after a newline, so prompting is not needed.
1259 static int file_peek(struct in_str *i)
1262 if (i->p && *i->p) {
1263 if (i->eof_flag && !i->p[1])
1266 /* note: ch is never NUL */
1268 do ch = fgetc(i->file); while (ch == '\0');
1269 i->eof_flag = (ch == EOF);
1270 i->peek_buf[0] = ch;
1271 i->peek_buf[1] = '\0';
1273 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1277 static void setup_file_in_str(struct in_str *i, FILE *f)
1279 i->peek = file_peek;
1281 #if ENABLE_HUSH_INTERACTIVE
1283 i->promptmode = 0; /* PS1 */
1289 static void setup_string_in_str(struct in_str *i, const char *s)
1291 i->peek = static_peek;
1292 i->get = static_get;
1293 #if ENABLE_HUSH_INTERACTIVE
1295 i->promptmode = 0; /* PS1 */
1305 #define B_CHUNK (32 * sizeof(char*))
1307 static void o_reset(o_string *o)
1315 static void o_free(o_string *o)
1318 memset(o, 0, sizeof(*o));
1321 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1326 static void o_grow_by(o_string *o, int len)
1328 if (o->length + len > o->maxlen) {
1329 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1330 o->data = xrealloc(o->data, 1 + o->maxlen);
1334 static void o_addchr(o_string *o, int ch)
1336 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1338 o->data[o->length] = ch;
1340 o->data[o->length] = '\0';
1343 static void o_addblock(o_string *o, const char *str, int len)
1346 memcpy(&o->data[o->length], str, len);
1348 o->data[o->length] = '\0';
1352 static void o_addstr(o_string *o, const char *str)
1354 o_addblock(o, str, strlen(str));
1358 static void o_addstr_with_NUL(o_string *o, const char *str)
1360 o_addblock(o, str, strlen(str) + 1);
1363 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1368 && (*str != '*' && *str != '?' && *str != '[')
1376 /* My analysis of quoting semantics tells me that state information
1377 * is associated with a destination, not a source.
1379 static void o_addqchr(o_string *o, int ch)
1382 char *found = strchr("*?[\\", ch);
1387 o->data[o->length] = '\\';
1390 o->data[o->length] = ch;
1392 o->data[o->length] = '\0';
1395 static void o_addQchr(o_string *o, int ch)
1398 if (o->o_escape && strchr("*?[\\", ch)) {
1400 o->data[o->length] = '\\';
1404 o->data[o->length] = ch;
1406 o->data[o->length] = '\0';
1409 static void o_addQstr(o_string *o, const char *str, int len)
1412 o_addblock(o, str, len);
1418 int ordinary_cnt = strcspn(str, "*?[\\");
1419 if (ordinary_cnt > len) /* paranoia */
1421 o_addblock(o, str, ordinary_cnt);
1422 if (ordinary_cnt == len)
1424 str += ordinary_cnt;
1425 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1429 if (ch) { /* it is necessarily one of "*?[\\" */
1431 o->data[o->length] = '\\';
1435 o->data[o->length] = ch;
1437 o->data[o->length] = '\0';
1441 /* A special kind of o_string for $VAR and `cmd` expansion.
1442 * It contains char* list[] at the beginning, which is grown in 16 element
1443 * increments. Actual string data starts at the next multiple of 16 * (char*).
1444 * list[i] contains an INDEX (int!) into this string data.
1445 * It means that if list[] needs to grow, data needs to be moved higher up
1446 * but list[i]'s need not be modified.
1447 * NB: remembering how many list[i]'s you have there is crucial.
1448 * o_finalize_list() operation post-processes this structure - calculates
1449 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1451 #if DEBUG_EXPAND || DEBUG_GLOB
1452 static void debug_print_list(const char *prefix, o_string *o, int n)
1454 char **list = (char**)o->data;
1455 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1457 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1458 prefix, list, n, string_start, o->length, o->maxlen);
1460 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1461 o->data + (int)list[i] + string_start,
1462 o->data + (int)list[i] + string_start);
1466 const char *p = o->data + (int)list[n - 1] + string_start;
1467 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1471 #define debug_print_list(prefix, o, n) ((void)0)
1474 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1475 * in list[n] so that it points past last stored byte so far.
1476 * It returns n+1. */
1477 static int o_save_ptr_helper(o_string *o, int n)
1479 char **list = (char**)o->data;
1483 if (!o->has_empty_slot) {
1484 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1485 string_len = o->length - string_start;
1486 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1487 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1488 /* list[n] points to string_start, make space for 16 more pointers */
1489 o->maxlen += 0x10 * sizeof(list[0]);
1490 o->data = xrealloc(o->data, o->maxlen + 1);
1491 list = (char**)o->data;
1492 memmove(list + n + 0x10, list + n, string_len);
1493 o->length += 0x10 * sizeof(list[0]);
1495 debug_printf_list("list[%d]=%d string_start=%d\n",
1496 n, string_len, string_start);
1499 /* We have empty slot at list[n], reuse without growth */
1500 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1501 string_len = o->length - string_start;
1502 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1503 n, string_len, string_start);
1504 o->has_empty_slot = 0;
1506 list[n] = (char*)(ptrdiff_t)string_len;
1510 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1511 static int o_get_last_ptr(o_string *o, int n)
1513 char **list = (char**)o->data;
1514 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1516 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1519 /* o_glob performs globbing on last list[], saving each result
1520 * as a new list[]. */
1521 static int o_glob(o_string *o, int n)
1527 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1529 return o_save_ptr_helper(o, n);
1530 pattern = o->data + o_get_last_ptr(o, n);
1531 debug_printf_glob("glob pattern '%s'\n", pattern);
1532 if (!glob_needed(pattern)) {
1534 o->length = unbackslash(pattern) - o->data;
1535 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1536 return o_save_ptr_helper(o, n);
1539 memset(&globdata, 0, sizeof(globdata));
1540 gr = glob(pattern, 0, NULL, &globdata);
1541 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1542 if (gr == GLOB_NOSPACE)
1543 bb_error_msg_and_die("out of memory during glob");
1544 if (gr == GLOB_NOMATCH) {
1545 globfree(&globdata);
1548 if (gr != 0) { /* GLOB_ABORTED ? */
1549 //TODO: testcase for bad glob pattern behavior
1550 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1552 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1553 char **argv = globdata.gl_pathv;
1554 o->length = pattern - o->data; /* "forget" pattern */
1556 o_addstr_with_NUL(o, *argv);
1557 n = o_save_ptr_helper(o, n);
1563 globfree(&globdata);
1565 debug_print_list("o_glob returning", o, n);
1569 /* If o->o_glob == 1, glob the string so far remembered.
1570 * Otherwise, just finish current list[] and start new */
1571 static int o_save_ptr(o_string *o, int n)
1573 if (o->o_glob) { /* if globbing is requested */
1574 /* If o->has_empty_slot, list[n] was already globbed
1575 * (if it was requested back then when it was filled)
1576 * so don't do that again! */
1577 if (!o->has_empty_slot)
1578 return o_glob(o, n); /* o_save_ptr_helper is inside */
1580 return o_save_ptr_helper(o, n);
1583 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1584 static char **o_finalize_list(o_string *o, int n)
1589 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1591 debug_print_list("finalized", o, n);
1592 debug_printf_expand("finalized n:%d\n", n);
1593 list = (char**)o->data;
1594 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1598 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1604 /* Expansion can recurse */
1605 #if ENABLE_HUSH_TICK
1606 static int process_command_subs(o_string *dest, const char *s);
1608 static char *expand_string_to_string(const char *str);
1610 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1611 parse_stream_dquoted(dest, input, dquote_end)
1613 static int parse_stream_dquoted(o_string *as_string,
1615 struct in_str *input,
1618 /* expand_strvec_to_strvec() takes a list of strings, expands
1619 * all variable references within and returns a pointer to
1620 * a list of expanded strings, possibly with larger number
1621 * of strings. (Think VAR="a b"; echo $VAR).
1622 * This new list is allocated as a single malloc block.
1623 * NULL-terminated list of char* pointers is at the beginning of it,
1624 * followed by strings themself.
1625 * Caller can deallocate entire list by single free(list). */
1627 /* Store given string, finalizing the word and starting new one whenever
1628 * we encounter IFS char(s). This is used for expanding variable values.
1629 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1630 static int expand_on_ifs(o_string *output, int n, const char *str)
1633 int word_len = strcspn(str, G.ifs);
1635 if (output->o_escape || !output->o_glob)
1636 o_addQstr(output, str, word_len);
1637 else /* protect backslashes against globbing up :) */
1638 o_addblock_duplicate_backslash(output, str, word_len);
1641 if (!*str) /* EOL - do not finalize word */
1643 o_addchr(output, '\0');
1644 debug_print_list("expand_on_ifs", output, n);
1645 n = o_save_ptr(output, n);
1646 str += strspn(str, G.ifs); /* skip ifs chars */
1648 debug_print_list("expand_on_ifs[1]", output, n);
1652 /* Expand all variable references in given string, adding words to list[]
1653 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1654 * to be filled). This routine is extremely tricky: has to deal with
1655 * variables/parameters with whitespace, $* and $@, and constructs like
1656 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1657 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1659 /* or_mask is either 0 (normal case) or 0x80
1660 * (expansion of right-hand side of assignment == 1-element expand.
1661 * It will also do no globbing, and thus we must not backslash-quote!) */
1663 char first_ch, ored_ch;
1670 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1671 debug_print_list("expand_vars_to_list", output, n);
1672 n = o_save_ptr(output, n);
1673 debug_print_list("expand_vars_to_list[0]", output, n);
1675 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1676 #if ENABLE_HUSH_TICK
1677 o_string subst_result = NULL_O_STRING;
1679 #if ENABLE_SH_MATH_SUPPORT
1680 char arith_buf[sizeof(arith_t)*3 + 2];
1682 o_addblock(output, arg, p - arg);
1683 debug_print_list("expand_vars_to_list[1]", output, n);
1685 p = strchr(p, SPECIAL_VAR_SYMBOL);
1687 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1688 /* "$@" is special. Even if quoted, it can still
1689 * expand to nothing (not even an empty string) */
1690 if ((first_ch & 0x7f) != '@')
1691 ored_ch |= first_ch;
1694 switch (first_ch & 0x7f) {
1695 /* Highest bit in first_ch indicates that var is double-quoted */
1697 val = utoa(G.root_pid);
1699 case '!': /* bg pid */
1700 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1702 case '?': /* exitcode */
1703 val = utoa(G.last_return_code);
1705 case '#': /* argc */
1706 if (arg[1] != SPECIAL_VAR_SYMBOL)
1707 /* actually, it's a ${#var} */
1709 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1714 if (!G.global_argv[i])
1716 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1717 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1718 smallint sv = output->o_escape;
1719 /* unquoted var's contents should be globbed, so don't escape */
1720 output->o_escape = 0;
1721 while (G.global_argv[i]) {
1722 n = expand_on_ifs(output, n, G.global_argv[i]);
1723 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1724 if (G.global_argv[i++][0] && G.global_argv[i]) {
1725 /* this argv[] is not empty and not last:
1726 * put terminating NUL, start new word */
1727 o_addchr(output, '\0');
1728 debug_print_list("expand_vars_to_list[2]", output, n);
1729 n = o_save_ptr(output, n);
1730 debug_print_list("expand_vars_to_list[3]", output, n);
1733 output->o_escape = sv;
1735 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1736 * and in this case should treat it like '$*' - see 'else...' below */
1737 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1739 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1740 if (++i >= G.global_argc)
1742 o_addchr(output, '\0');
1743 debug_print_list("expand_vars_to_list[4]", output, n);
1744 n = o_save_ptr(output, n);
1746 } else { /* quoted $*: add as one word */
1748 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1749 if (!G.global_argv[++i])
1752 o_addchr(output, G.ifs[0]);
1756 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1757 /* "Empty variable", used to make "" etc to not disappear */
1761 #if ENABLE_HUSH_TICK
1762 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1765 //TODO: can we just stuff it into "output" directly?
1766 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1767 process_command_subs(&subst_result, arg);
1768 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1769 val = subst_result.data;
1772 #if ENABLE_SH_MATH_SUPPORT
1773 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1774 arith_eval_hooks_t hooks;
1779 arg++; /* skip '+' */
1780 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1781 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1783 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1785 if (strchr(arg, '$') != NULL
1786 #if ENABLE_HUSH_TICK
1787 || strchr(arg, '`') != NULL
1790 /* We need to expand. Example:
1791 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1793 struct in_str input;
1794 o_string dest = NULL_O_STRING;
1796 setup_string_in_str(&input, arg);
1797 parse_stream_dquoted(NULL, &dest, &input, EOF);
1798 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1799 exp_str = expand_string_to_string(dest.data);
1800 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1801 o_free_unsafe(&dest);
1803 hooks.lookupvar = get_local_var_value;
1804 hooks.setvar = arith_set_local_var;
1805 hooks.endofname = endofname;
1806 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1811 case -3: maybe_die("arith", "exponent less than 0"); break;
1812 case -2: maybe_die("arith", "divide by zero"); break;
1813 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1814 default: maybe_die("arith", "syntax error"); break;
1817 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1818 sprintf(arith_buf, arith_t_fmt, res);
1823 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1825 bool exp_len = false;
1826 bool exp_null = false;
1828 char exp_save = exp_save; /* for compiler */
1829 char exp_op = exp_op; /* for compiler */
1830 char *exp_word = exp_word; /* for compiler */
1834 arg[0] = first_ch & 0x7f;
1836 /* prepare for expansions */
1837 if (var[0] == '#') {
1838 /* handle length expansion ${#var} */
1842 /* maybe handle parameter expansion */
1843 exp_off = strcspn(var, ":-=+?");
1847 exp_save = var[exp_off];
1848 exp_null = exp_save == ':';
1849 exp_word = var + exp_off;
1850 if (exp_null) ++exp_word;
1851 exp_op = *exp_word++;
1852 var[exp_off] = '\0';
1856 /* lookup the variable in question */
1857 if (isdigit(var[0])) {
1858 /* handle_dollar() should have vetted var for us */
1860 if (i < G.global_argc)
1861 val = G.global_argv[i];
1862 /* else val remains NULL: $N with too big N */
1864 val = get_local_var_value(var);
1866 /* handle any expansions */
1868 debug_printf_expand("expand: length of '%s' = ", val);
1869 val = utoa(val ? strlen(val) : 0);
1870 debug_printf_expand("%s\n", val);
1871 } else if (exp_off) {
1872 /* we need to do an expansion */
1873 int exp_test = (!val || (exp_null && !val[0]));
1875 exp_test = !exp_test;
1876 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1877 exp_null ? "true" : "false", exp_test);
1880 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1884 if (exp_op == '=') {
1885 if (isdigit(var[0]) || var[0] == '#') {
1886 maybe_die(var, "special vars cannot assign in this way");
1889 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1890 sprintf(new_var, "%s=%s", var, val);
1891 set_local_var(new_var, -1, 0);
1895 var[exp_off] = exp_save;
1899 #if ENABLE_HUSH_TICK
1902 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1903 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1905 /* unquoted var's contents should be globbed, so don't escape */
1906 smallint sv = output->o_escape;
1907 output->o_escape = 0;
1908 n = expand_on_ifs(output, n, val);
1910 output->o_escape = sv;
1912 } else { /* quoted $VAR, val will be appended below */
1913 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1916 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1918 o_addQstr(output, val, strlen(val));
1920 /* Do the check to avoid writing to a const string */
1921 if (*p != SPECIAL_VAR_SYMBOL)
1922 *p = SPECIAL_VAR_SYMBOL;
1924 #if ENABLE_HUSH_TICK
1925 o_free(&subst_result);
1928 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1931 debug_print_list("expand_vars_to_list[a]", output, n);
1932 /* this part is literal, and it was already pre-quoted
1933 * if needed (much earlier), do not use o_addQstr here! */
1934 o_addstr_with_NUL(output, arg);
1935 debug_print_list("expand_vars_to_list[b]", output, n);
1936 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1937 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1940 /* allow to reuse list[n] later without re-growth */
1941 output->has_empty_slot = 1;
1943 o_addchr(output, '\0');
1948 static char **expand_variables(char **argv, int or_mask)
1953 o_string output = NULL_O_STRING;
1955 if (or_mask & 0x100) {
1956 output.o_escape = 1; /* protect against globbing for "$var" */
1957 /* (unquoted $var will temporarily switch it off) */
1964 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1967 debug_print_list("expand_variables", &output, n);
1969 /* output.data (malloced in one block) gets returned in "list" */
1970 list = o_finalize_list(&output, n);
1971 debug_print_strings("expand_variables[1]", list);
1975 static char **expand_strvec_to_strvec(char **argv)
1977 return expand_variables(argv, 0x100);
1980 /* Used for expansion of right hand of assignments */
1981 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1983 static char *expand_string_to_string(const char *str)
1985 char *argv[2], **list;
1987 argv[0] = (char*)str;
1989 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1991 if (!list[0] || list[1])
1992 bb_error_msg_and_die("BUG in varexp2");
1993 /* actually, just move string 2*sizeof(char*) bytes back */
1994 overlapping_strcpy((char*)list, list[0]);
1995 debug_printf_expand("string_to_string='%s'\n", (char*)list);
1999 /* Used for "eval" builtin */
2000 static char* expand_strvec_to_string(char **argv)
2004 list = expand_variables(argv, 0x80);
2005 /* Convert all NULs to spaces */
2010 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2011 bb_error_msg_and_die("BUG in varexp3");
2012 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2016 overlapping_strcpy((char*)list, list[0]);
2017 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2021 static char **expand_assignments(char **argv, int count)
2025 /* Expand assignments into one string each */
2026 for (i = 0; i < count; i++) {
2027 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2033 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2034 * and stderr if they are redirected. */
2035 static int setup_redirects(struct command *prog, int squirrel[])
2038 struct redir_struct *redir;
2040 for (redir = prog->redirects; redir; redir = redir->next) {
2041 if (redir->dup == -1 && redir->rd_filename == NULL) {
2042 /* something went wrong in the parse. Pretend it didn't happen */
2045 if (redir->dup == -1) {
2047 mode = redir_table[redir->rd_type].mode;
2048 //TODO: check redir for names like '\\'
2049 p = expand_string_to_string(redir->rd_filename);
2050 openfd = open_or_warn(p, mode);
2053 /* this could get lost if stderr has been redirected, but
2054 bash and ash both lose it as well (though zsh doesn't!) */
2058 openfd = redir->dup;
2061 if (openfd != redir->fd) {
2062 if (squirrel && redir->fd < 3) {
2063 squirrel[redir->fd] = dup(redir->fd);
2066 /* "-" means "close me" and we use -3 for that */
2069 dup2(openfd, redir->fd);
2070 if (redir->dup == -1)
2078 static void restore_redirects(int squirrel[])
2081 for (i = 0; i < 3; i++) {
2084 /* We simply die on error */
2092 #define free_pipe_list(head, indent) free_pipe_list(head)
2093 #define free_pipe(pi, indent) free_pipe(pi)
2095 static void free_pipe_list(struct pipe *head, int indent);
2097 /* Return code is the exit status of the pipe */
2098 static void free_pipe(struct pipe *pi, int indent)
2101 struct command *command;
2102 struct redir_struct *r, *rnext;
2105 if (pi->stopped_cmds > 0) /* why? */
2107 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2108 for (i = 0; i < pi->num_cmds; i++) {
2109 command = &pi->cmds[i];
2110 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2111 if (command->argv) {
2112 for (a = 0, p = command->argv; *p; a++, p++) {
2113 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2115 free_strings(command->argv);
2116 command->argv = NULL;
2118 /* not "else if": on syntax error, we may have both! */
2119 if (command->group) {
2120 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2121 free_pipe_list(command->group, indent+3);
2122 debug_printf_clean("%s end group\n", indenter(indent));
2123 command->group = NULL;
2126 free(command->group_as_string);
2127 command->group_as_string = NULL;
2129 for (r = command->redirects; r; r = rnext) {
2130 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2132 /* guard against the case >$FOO, where foo is unset or blank */
2133 if (r->rd_filename) {
2134 debug_printf_clean(" %s\n", r->rd_filename);
2135 free(r->rd_filename);
2136 r->rd_filename = NULL;
2139 debug_printf_clean("&%d\n", r->dup);
2144 command->redirects = NULL;
2146 free(pi->cmds); /* children are an array, they get freed all at once */
2154 static void free_pipe_list(struct pipe *head, int indent)
2156 struct pipe *pi, *next;
2158 for (pi = head; pi; pi = next) {
2160 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2162 free_pipe(pi, indent);
2163 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2165 /*pi->next = NULL;*/
2172 typedef struct nommu_save_t {
2178 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2179 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2180 #define pseudo_exec(nommu_save, command, argv_expanded) \
2181 pseudo_exec(command, argv_expanded)
2184 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2186 * XXX no exit() here. If you don't exec, use _exit instead.
2187 * The at_exit handlers apparently confuse the calling process,
2188 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2189 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2190 char **argv, int assignment_cnt,
2191 char **argv_expanded) NORETURN;
2192 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2193 char **argv, int assignment_cnt,
2194 char **argv_expanded)
2198 /* Case when we are here: ... | var=val | ... */
2199 if (!argv[assignment_cnt])
2200 _exit(EXIT_SUCCESS);
2202 new_env = expand_assignments(argv, assignment_cnt);
2204 putenv_all(new_env);
2205 free(new_env); /* optional */
2207 nommu_save->new_env = new_env;
2208 nommu_save->old_env = putenv_all_and_save_old(new_env);
2210 if (argv_expanded) {
2211 argv = argv_expanded;
2213 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2215 nommu_save->argv = argv;
2219 /* On NOMMU, we must never block!
2220 * Example: { sleep 99999 | read line } & echo Ok
2221 * read builtin will block on read syscall, leaving parent blocked
2222 * in vfork. Therefore we can't do this:
2225 /* Check if the command matches any of the builtins.
2226 * Depending on context, this might be redundant. But it's
2227 * easier to waste a few CPU cycles than it is to figure out
2228 * if this is one of those cases.
2232 const struct built_in_command *x;
2233 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2234 if (strcmp(argv[0], x->cmd) == 0) {
2235 debug_printf_exec("running builtin '%s'\n",
2237 rcode = x->function(argv);
2245 #if ENABLE_FEATURE_SH_STANDALONE
2246 /* Check if the command matches any busybox applets */
2247 if (strchr(argv[0], '/') == NULL) {
2248 int a = find_applet_by_name(argv[0]);
2250 #if BB_MMU /* see above why on NOMMU it is not allowed */
2251 if (APPLET_IS_NOEXEC(a)) {
2252 debug_printf_exec("running applet '%s'\n", argv[0]);
2253 run_applet_no_and_exit(a, argv);
2256 /* Re-exec ourselves */
2257 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2258 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2259 execv(bb_busybox_exec_path, argv);
2260 /* If they called chroot or otherwise made the binary no longer
2261 * executable, fall through */
2266 debug_printf_exec("execing '%s'\n", argv[0]);
2267 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2268 execvp(argv[0], argv);
2269 bb_perror_msg("can't exec '%s'", argv[0]);
2270 _exit(EXIT_FAILURE);
2274 static void reset_traps_to_defaults(void)
2282 for (sig = 0; sig < NSIG; sig++) {
2286 G.traps[sig] = NULL;
2287 /* There is no signal for 0 (EXIT) */
2290 /* there was a trap handler, we are removing it
2291 * (if sig has non-DFL handling,
2292 * we don't need to do anything) */
2293 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2295 sigdelset(&G.blocked_set, sig);
2299 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2301 #define clean_up_after_re_execute() ((void)0)
2305 static void re_execute_shell(const char *s) NORETURN;
2306 static void re_execute_shell(const char *s)
2308 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2309 struct variable *cur;
2310 char **argv, **pp, **pp2;
2313 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2314 , (unsigned) G.root_pid
2315 , (unsigned) G.last_bg_pid
2316 , (unsigned) G.last_return_code
2317 USE_HUSH_LOOPS(, G.depth_of_loop)
2319 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2320 * 3:-c 4:<cmd> <argN...> 5:NULL
2322 cnt = 5 + G.global_argc;
2323 for (cur = G.top_var; cur; cur = cur->next) {
2324 if (!cur->flg_export || cur->flg_read_only)
2327 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2328 *pp++ = (char *) G.argv0_for_re_execing;
2330 for (cur = G.top_var; cur; cur = cur->next) {
2331 if (cur->varstr == hush_version_str)
2333 if (cur->flg_read_only) {
2334 *pp++ = (char *) "-R";
2335 *pp++ = cur->varstr;
2336 } else if (!cur->flg_export) {
2337 *pp++ = (char *) "-V";
2338 *pp++ = cur->varstr;
2341 //TODO: pass functions
2342 /* We can pass activated traps here. Say, -Tnn:trap_string
2344 * However, POSIX says that subshells reset signals with traps
2346 * I tested bash-3.2 and it not only does that with true subshells
2347 * of the form ( list ), but with any forked children shells.
2348 * I set trap "echo W" WINCH; and then tried:
2350 * { echo 1; sleep 20; echo 2; } &
2351 * while true; do echo 1; sleep 20; echo 2; break; done &
2352 * true | { echo 1; sleep 20; echo 2; } | cat
2354 * In all these cases sending SIGWINCH to the child shell
2355 * did not run the trap. If I add trap "echo V" WINCH;
2356 * _inside_ group (just before echo 1), it works.
2358 * I conclude it means we don't need to pass active traps here.
2359 * exec syscall below resets them to SIG_DFL for us.
2361 *pp++ = (char *) "-c";
2363 pp2 = G.global_argv;
2366 /* *pp = NULL; - is already there */
2368 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2369 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2370 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2371 /* Fallback. Useful for init=/bin/hush usage etc */
2372 if (G.argv0_for_re_execing[0] == '/')
2373 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2374 xfunc_error_retval = 127;
2375 bb_error_msg_and_die("can't re-execute the shell");
2378 static void clean_up_after_re_execute(void)
2380 char **pp = G.argv_from_re_execing;
2382 /* Must match re_execute_shell's allocations (if any) */
2384 G.argv_from_re_execing = NULL;
2389 static int run_list(struct pipe *pi);
2391 /* Called after [v]fork() in run_pipe
2393 static void pseudo_exec(nommu_save_t *nommu_save,
2394 struct command *command,
2395 char **argv_expanded) NORETURN;
2396 static void pseudo_exec(nommu_save_t *nommu_save,
2397 struct command *command,
2398 char **argv_expanded)
2400 if (command->argv) {
2401 pseudo_exec_argv(nommu_save, command->argv,
2402 command->assignment_cnt, argv_expanded);
2405 if (command->group) {
2406 /* Cases when we are here:
2409 * ... | ( list ) | ...
2410 * ... | { list } | ...
2414 debug_printf_exec("pseudo_exec: run_list\n");
2415 reset_traps_to_defaults();
2416 rcode = run_list(command->group);
2417 /* OK to leak memory by not calling free_pipe_list,
2418 * since this process is about to exit */
2421 re_execute_shell(command->group_as_string);
2425 /* Case when we are here: ... | >file */
2426 debug_printf_exec("pseudo_exec'ed null command\n");
2427 _exit(EXIT_SUCCESS);
2431 static const char *get_cmdtext(struct pipe *pi)
2437 /* This is subtle. ->cmdtext is created only on first backgrounding.
2438 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2439 * On subsequent bg argv is trashed, but we won't use it */
2442 argv = pi->cmds[0].argv;
2443 if (!argv || !argv[0]) {
2444 pi->cmdtext = xzalloc(1);
2449 do len += strlen(*argv) + 1; while (*++argv);
2450 pi->cmdtext = p = xmalloc(len);
2451 argv = pi->cmds[0].argv;
2453 len = strlen(*argv);
2454 memcpy(p, *argv, len);
2462 static void insert_bg_job(struct pipe *pi)
2464 struct pipe *thejob;
2467 /* Linear search for the ID of the job to use */
2469 for (thejob = G.job_list; thejob; thejob = thejob->next)
2470 if (thejob->jobid >= pi->jobid)
2471 pi->jobid = thejob->jobid + 1;
2473 /* Add thejob to the list of running jobs */
2475 thejob = G.job_list = xmalloc(sizeof(*thejob));
2477 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2479 thejob->next = xmalloc(sizeof(*thejob));
2480 thejob = thejob->next;
2483 /* Physically copy the struct job */
2484 memcpy(thejob, pi, sizeof(struct pipe));
2485 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2486 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2487 for (i = 0; i < pi->num_cmds; i++) {
2488 // TODO: do we really need to have so many fields which are just dead weight
2489 // at execution stage?
2490 thejob->cmds[i].pid = pi->cmds[i].pid;
2491 /* all other fields are not used and stay zero */
2493 thejob->next = NULL;
2494 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2496 /* We don't wait for background thejobs to return -- append it
2497 to the list of backgrounded thejobs and leave it alone */
2498 if (G_interactive_fd)
2499 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2500 G.last_bg_pid = thejob->cmds[0].pid;
2501 G.last_jobid = thejob->jobid;
2504 static void remove_bg_job(struct pipe *pi)
2506 struct pipe *prev_pipe;
2508 if (pi == G.job_list) {
2509 G.job_list = pi->next;
2511 prev_pipe = G.job_list;
2512 while (prev_pipe->next != pi)
2513 prev_pipe = prev_pipe->next;
2514 prev_pipe->next = pi->next;
2517 G.last_jobid = G.job_list->jobid;
2522 /* Remove a backgrounded job */
2523 static void delete_finished_bg_job(struct pipe *pi)
2526 pi->stopped_cmds = 0;
2532 /* Check to see if any processes have exited -- if they
2533 * have, figure out why and see if a job has completed */
2534 static int checkjobs(struct pipe* fg_pipe)
2544 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2547 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2548 // /* avoid doing syscall, nothing there anyway */
2551 attributes = WUNTRACED;
2552 if (fg_pipe == NULL)
2553 attributes |= WNOHANG;
2555 /* Do we do this right?
2556 * bash-3.00# sleep 20 | false
2558 * [3]+ Stopped sleep 20 | false
2559 * bash-3.00# echo $?
2560 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2563 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2564 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2565 // + killall -STOP cat
2572 // i = G.count_SIGCHLD;
2573 childpid = waitpid(-1, &status, attributes);
2574 if (childpid <= 0) {
2575 if (childpid && errno != ECHILD)
2576 bb_perror_msg("waitpid");
2577 // else /* Until next SIGCHLD, waitpid's are useless */
2578 // G.handled_SIGCHLD = i;
2581 dead = WIFEXITED(status) || WIFSIGNALED(status);
2584 if (WIFSTOPPED(status))
2585 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2586 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2587 if (WIFSIGNALED(status))
2588 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2589 childpid, WTERMSIG(status), WEXITSTATUS(status));
2590 if (WIFEXITED(status))
2591 debug_printf_jobs("pid %d exited, exitcode %d\n",
2592 childpid, WEXITSTATUS(status));
2594 /* Were we asked to wait for fg pipe? */
2596 for (i = 0; i < fg_pipe->num_cmds; i++) {
2597 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2598 if (fg_pipe->cmds[i].pid != childpid)
2600 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2602 fg_pipe->cmds[i].pid = 0;
2603 fg_pipe->alive_cmds--;
2604 if (i == fg_pipe->num_cmds - 1) {
2605 /* last process gives overall exitstatus */
2606 rcode = WEXITSTATUS(status);
2607 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2610 fg_pipe->cmds[i].is_stopped = 1;
2611 fg_pipe->stopped_cmds++;
2613 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2614 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2615 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2616 /* All processes in fg pipe have exited/stopped */
2618 if (fg_pipe->alive_cmds)
2619 insert_bg_job(fg_pipe);
2623 /* There are still running processes in the fg pipe */
2624 goto wait_more; /* do waitpid again */
2626 /* it wasnt fg_pipe, look for process in bg pipes */
2630 /* We asked to wait for bg or orphaned children */
2631 /* No need to remember exitcode in this case */
2632 for (pi = G.job_list; pi; pi = pi->next) {
2633 for (i = 0; i < pi->num_cmds; i++) {
2634 if (pi->cmds[i].pid == childpid)
2635 goto found_pi_and_prognum;
2638 /* Happens when shell is used as init process (init=/bin/sh) */
2639 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2640 continue; /* do waitpid again */
2642 found_pi_and_prognum:
2645 pi->cmds[i].pid = 0;
2647 if (!pi->alive_cmds) {
2648 if (G_interactive_fd)
2649 printf(JOB_STATUS_FORMAT, pi->jobid,
2650 "Done", pi->cmdtext);
2651 delete_finished_bg_job(pi);
2655 pi->cmds[i].is_stopped = 1;
2659 } /* while (waitpid succeeds)... */
2665 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2668 int rcode = checkjobs(fg_pipe);
2669 /* Job finished, move the shell to the foreground */
2670 p = getpgid(0); /* pgid of our process */
2671 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2672 tcsetpgrp(G_interactive_fd, p);
2677 /* Start all the jobs, but don't wait for anything to finish.
2680 * Return code is normally -1, when the caller has to wait for children
2681 * to finish to determine the exit status of the pipe. If the pipe
2682 * is a simple builtin command, however, the action is done by the
2683 * time run_pipe returns, and the exit code is provided as the
2686 * Returns -1 only if started some children. IOW: we have to
2687 * mask out retvals of builtins etc with 0xff!
2689 * The only case when we do not need to [v]fork is when the pipe
2690 * is single, non-backgrounded, non-subshell command. Examples:
2691 * cmd ; ... { list } ; ...
2692 * cmd && ... { list } && ...
2693 * cmd || ... { list } || ...
2694 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2695 * or (if SH_STANDALONE) an applet, and we can run the { list }
2696 * with run_list(). If it isn't one of these, we fork and exec cmd.
2698 * Cases when we must fork:
2699 * non-single: cmd | cmd
2700 * backgrounded: cmd & { list } &
2701 * subshell: ( list ) [&]
2703 static int run_pipe(struct pipe *pi)
2705 static const char *const null_ptr = NULL;
2708 int pipefds[2]; /* pipefds[0] is for reading */
2709 struct command *command;
2710 char **argv_expanded;
2713 /* it is not always needed, but we aim to smaller code */
2714 int squirrel[] = { -1, -1, -1 };
2717 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2719 USE_HUSH_JOB(pi->pgrp = -1;)
2720 pi->stopped_cmds = 0;
2721 command = &(pi->cmds[0]);
2722 argv_expanded = NULL;
2724 if (pi->num_cmds != 1
2725 || pi->followup == PIPE_BG
2726 || command->grp_type == GRP_SUBSHELL
2733 debug_printf_exec(": group:%p argv:'%s'\n",
2734 command->group, command->argv ? command->argv[0] : "NONE");
2736 if (command->group) {
2737 #if ENABLE_HUSH_FUNCTIONS
2738 if (command->grp_type == GRP_FUNCTION) {
2739 /* func () { list } */
2740 bb_error_msg("here we ought to remember function definition, and go on");
2741 return EXIT_SUCCESS;
2745 debug_printf("non-subshell group\n");
2746 setup_redirects(command, squirrel);
2747 debug_printf_exec(": run_list\n");
2748 rcode = run_list(command->group) & 0xff;
2749 restore_redirects(squirrel);
2750 debug_printf_exec("run_pipe return %d\n", rcode);
2751 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2755 argv = command->argv ? command->argv : (char **) &null_ptr;
2757 const struct built_in_command *x;
2758 char **new_env = NULL;
2759 char **old_env = NULL;
2761 if (argv[command->assignment_cnt] == NULL) {
2762 /* Assignments, but no command */
2763 /* Ensure redirects take effect. Try "a=t >file" */
2764 setup_redirects(command, squirrel);
2765 restore_redirects(squirrel);
2766 /* Set shell variables */
2768 p = expand_string_to_string(*argv);
2769 debug_printf_exec("set shell var:'%s'->'%s'\n",
2771 set_local_var(p, 0, 0);
2774 /* Do we need to flag set_local_var() errors?
2775 * "assignment to readonly var" and "putenv error"
2777 return EXIT_SUCCESS;
2780 /* Expand the rest into (possibly) many strings each */
2781 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2783 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2784 if (strcmp(argv_expanded[0], x->cmd) != 0)
2786 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2787 debug_printf("exec with redirects only\n");
2788 setup_redirects(command, NULL);
2789 rcode = EXIT_SUCCESS;
2790 goto clean_up_and_ret1;
2792 debug_printf("builtin inline %s\n", argv_expanded[0]);
2793 /* XXX setup_redirects acts on file descriptors, not FILEs.
2794 * This is perfect for work that comes after exec().
2795 * Is it really safe for inline use? Experimentally,
2796 * things seem to work with glibc. */
2797 setup_redirects(command, squirrel);
2798 new_env = expand_assignments(argv, command->assignment_cnt);
2799 old_env = putenv_all_and_save_old(new_env);
2800 debug_printf_exec(": builtin '%s' '%s'...\n",
2801 x->cmd, argv_expanded[1]);
2802 rcode = x->function(argv_expanded) & 0xff;
2803 #if ENABLE_FEATURE_SH_STANDALONE
2806 restore_redirects(squirrel);
2807 free_strings_and_unsetenv(new_env, 1);
2808 putenv_all(old_env);
2809 free(old_env); /* not free_strings()! */
2811 free(argv_expanded);
2812 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2813 debug_printf_exec("run_pipe return %d\n", rcode);
2816 #if ENABLE_FEATURE_SH_STANDALONE
2817 i = find_applet_by_name(argv_expanded[0]);
2818 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2819 setup_redirects(command, squirrel);
2820 save_nofork_data(&G.nofork_save);
2821 new_env = expand_assignments(argv, command->assignment_cnt);
2822 old_env = putenv_all_and_save_old(new_env);
2823 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2824 argv_expanded[0], argv_expanded[1]);
2825 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2826 goto clean_up_and_ret;
2829 /* It is neither builtin nor applet. We must fork. */
2833 /* NB: argv_expanded may already be created, and that
2834 * might include `cmd` runs! Do not rerun it! We *must*
2835 * use argv_expanded if it's non-NULL */
2837 /* Going to fork a child per each pipe member */
2841 for (i = 0; i < pi->num_cmds; i++) {
2843 volatile nommu_save_t nommu_save;
2844 nommu_save.new_env = NULL;
2845 nommu_save.old_env = NULL;
2846 nommu_save.argv = NULL;
2848 command = &(pi->cmds[i]);
2849 if (command->argv) {
2850 debug_printf_exec(": pipe member '%s' '%s'...\n",
2851 command->argv[0], command->argv[1]);
2853 debug_printf_exec(": pipe member with no argv\n");
2856 /* pipes are inserted between pairs of commands */
2859 if ((i + 1) < pi->num_cmds)
2862 command->pid = BB_MMU ? fork() : vfork();
2863 if (!command->pid) { /* child */
2865 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
2867 /* Every child adds itself to new process group
2868 * with pgid == pid_of_first_child_in_pipe */
2869 if (G.run_list_level == 1 && G_interactive_fd) {
2872 if (pgrp < 0) /* true for 1st process only */
2874 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2875 /* We do it in *every* child, not just first,
2877 tcsetpgrp(G_interactive_fd, pgrp);
2881 xmove_fd(nextin, 0);
2882 xmove_fd(pipefds[1], 1); /* write end */
2884 close(pipefds[0]); /* read end */
2885 /* Like bash, explicit redirects override pipes,
2886 * and the pipe fd is available for dup'ing. */
2887 setup_redirects(command, NULL);
2889 /* Restore default handlers just prior to exec */
2890 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2892 /* Stores to nommu_save list of env vars putenv'ed
2893 * (NOMMU, on MMU we don't need that) */
2894 /* cast away volatility... */
2895 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2896 /* pseudo_exec() does not return */
2899 /* parent or error */
2901 die_sleep = -1; /* restore tty pgrp on xfunc death */
2904 /* Clean up after vforked child */
2905 clean_up_after_re_execute();
2906 free(nommu_save.argv);
2907 free_strings_and_unsetenv(nommu_save.new_env, 1);
2908 putenv_all(nommu_save.old_env);
2910 free(argv_expanded);
2911 argv_expanded = NULL;
2912 if (command->pid < 0) { /* [v]fork failed */
2913 /* Clearly indicate, was it fork or vfork */
2914 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2918 /* Second and next children need to know pid of first one */
2920 pi->pgrp = command->pid;
2926 if ((i + 1) < pi->num_cmds)
2927 close(pipefds[1]); /* write end */
2928 /* Pass read (output) pipe end to next iteration */
2929 nextin = pipefds[0];
2932 if (!pi->alive_cmds) {
2933 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2937 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2941 #ifndef debug_print_tree
2942 static void debug_print_tree(struct pipe *pi, int lvl)
2944 static const char *const PIPE[] = {
2950 static const char *RES[] = {
2951 [RES_NONE ] = "NONE" ,
2954 [RES_THEN ] = "THEN" ,
2955 [RES_ELIF ] = "ELIF" ,
2956 [RES_ELSE ] = "ELSE" ,
2959 #if ENABLE_HUSH_LOOPS
2960 [RES_FOR ] = "FOR" ,
2961 [RES_WHILE] = "WHILE",
2962 [RES_UNTIL] = "UNTIL",
2964 [RES_DONE ] = "DONE" ,
2966 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2969 #if ENABLE_HUSH_CASE
2970 [RES_CASE ] = "CASE" ,
2971 [RES_MATCH] = "MATCH",
2972 [RES_CASEI] = "CASEI",
2973 [RES_ESAC ] = "ESAC" ,
2975 [RES_XXXX ] = "XXXX" ,
2976 [RES_SNTX ] = "SNTX" ,
2978 static const char *const GRPTYPE[] = {
2981 #if ENABLE_HUSH_FUNCTIONS
2990 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2991 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2993 while (prn < pi->num_cmds) {
2994 struct command *command = &pi->cmds[prn];
2995 char **argv = command->argv;
2997 fprintf(stderr, "%*s prog %d assignment_cnt:%d",
2999 command->assignment_cnt);
3000 if (command->group) {
3001 fprintf(stderr, " group %s: (argv=%p)\n",
3002 GRPTYPE[command->grp_type],
3004 debug_print_tree(command->group, lvl+1);
3008 if (argv) while (*argv) {
3009 fprintf(stderr, " '%s'", *argv);
3012 fprintf(stderr, "\n");
3021 /* NB: called by pseudo_exec, and therefore must not modify any
3022 * global data until exec/_exit (we can be a child after vfork!) */
3023 static int run_list(struct pipe *pi)
3025 #if ENABLE_HUSH_CASE
3026 char *case_word = NULL;
3028 #if ENABLE_HUSH_LOOPS
3029 struct pipe *loop_top = NULL;
3030 char *for_varname = NULL;
3031 char **for_lcur = NULL;
3032 char **for_list = NULL;
3034 smallint last_followup;
3036 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3037 smalluint cond_code = 0;
3039 enum { cond_code = 0 };
3041 /*enum reserved_style*/ smallint rword;
3042 /*enum reserved_style*/ smallint last_rword;
3044 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3046 #if ENABLE_HUSH_LOOPS
3047 /* Check syntax for "for" */
3048 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3049 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3051 /* current word is FOR or IN (BOLD in comments below) */
3052 if (cpipe->next == NULL) {
3053 syntax("malformed for");
3054 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3057 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3058 if (cpipe->next->res_word == RES_DO)
3060 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3061 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3062 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3064 syntax("malformed for");
3065 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3071 /* Past this point, all code paths should jump to ret: label
3072 * in order to return, no direct "return" statements please.
3073 * This helps to ensure that no memory is leaked. */
3075 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3078 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3079 * We are saving state before entering outermost list ("while...done")
3080 * so that ctrl-Z will correctly background _entire_ outermost list,
3081 * not just a part of it (like "sleep 1 | exit 2") */
3082 if (++G.run_list_level == 1 && G_interactive_fd) {
3083 if (sigsetjmp(G.toplevel_jb, 1)) {
3084 /* ctrl-Z forked and we are parent; or ctrl-C.
3085 * Sighandler has longjmped us here */
3086 signal(SIGINT, SIG_IGN);
3087 signal(SIGTSTP, SIG_IGN);
3088 /* Restore level (we can be coming from deep inside
3090 G.run_list_level = 1;
3091 #if ENABLE_FEATURE_SH_STANDALONE
3092 if (G.nofork_save.saved) { /* if save area is valid */
3093 debug_printf_jobs("exiting nofork early\n");
3094 restore_nofork_data(&G.nofork_save);
3097 //// if (G.ctrl_z_flag) {
3098 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3099 //// * Remember this child as background job */
3100 //// insert_bg_job(pi);
3102 /* ctrl-C. We just stop doing whatever we were doing */
3105 USE_HUSH_LOOPS(loop_top = NULL;)
3106 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3110 //// /* ctrl-Z handler will store pid etc in pi */
3111 //// G.toplevel_list = pi;
3112 //// G.ctrl_z_flag = 0;
3113 ////#if ENABLE_FEATURE_SH_STANDALONE
3114 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3116 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3117 //// signal(SIGINT, handler_ctrl_c);
3121 rcode = G.last_return_code;
3123 last_rword = RES_XXXX;
3124 last_followup = PIPE_SEQ;
3126 /* Go through list of pipes, (maybe) executing them. */
3127 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3131 IF_HAS_KEYWORDS(rword = pi->res_word;)
3132 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
3133 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3134 rword, cond_code, last_rword);
3135 #if ENABLE_HUSH_LOOPS
3136 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3137 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3139 /* start of a loop: remember where loop starts */
3144 /* Still in the same "if...", "then..." or "do..." branch? */
3145 if (rword == last_rword) {
3146 if ((rcode == 0 && last_followup == PIPE_OR)
3147 || (rcode != 0 && last_followup == PIPE_AND)
3149 /* It is "<true> || CMD" or "<false> && CMD"
3150 * and we should not execute CMD */
3151 debug_printf_exec("skipped cmd because of || or &&\n");
3152 last_followup = pi->followup;
3156 last_followup = pi->followup;
3160 if (rword == RES_THEN) {
3161 /* "if <false> THEN cmd": skip cmd */
3165 if (rword == RES_ELSE || rword == RES_ELIF) {
3166 /* "if <true> then ... ELSE/ELIF cmd":
3167 * skip cmd and all following ones */
3172 #if ENABLE_HUSH_LOOPS
3173 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3175 /* first loop through for */
3177 static const char encoded_dollar_at[] ALIGN1 = {
3178 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3179 }; /* encoded representation of "$@" */
3180 static const char *const encoded_dollar_at_argv[] = {
3181 encoded_dollar_at, NULL
3182 }; /* argv list with one element: "$@" */
3185 vals = (char**)encoded_dollar_at_argv;
3186 if (pi->next->res_word == RES_IN) {
3187 /* if no variable values after "in" we skip "for" */
3188 if (!pi->next->cmds[0].argv) {
3189 G.last_return_code = rcode = EXIT_SUCCESS;
3190 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3193 vals = pi->next->cmds[0].argv;
3194 } /* else: "for var; do..." -> assume "$@" list */
3195 /* create list of variable values */
3196 debug_print_strings("for_list made from", vals);
3197 for_list = expand_strvec_to_strvec(vals);
3198 for_lcur = for_list;
3199 debug_print_strings("for_list", for_list);
3200 for_varname = pi->cmds[0].argv[0];
3201 pi->cmds[0].argv[0] = NULL;
3203 free(pi->cmds[0].argv[0]);
3205 /* "for" loop is over, clean up */
3209 pi->cmds[0].argv[0] = for_varname;
3212 /* Insert next value from for_lcur */
3213 //TODO: does it need escaping?
3214 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3215 pi->cmds[0].assignment_cnt = 1;
3217 if (rword == RES_IN) {
3218 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3220 if (rword == RES_DONE) {
3221 continue; /* "done" has no cmds too */
3224 #if ENABLE_HUSH_CASE
3225 if (rword == RES_CASE) {
3226 case_word = expand_strvec_to_string(pi->cmds->argv);
3229 if (rword == RES_MATCH) {
3232 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3234 /* all prev words didn't match, does this one match? */
3235 argv = pi->cmds->argv;
3237 char *pattern = expand_string_to_string(*argv);
3238 /* TODO: which FNM_xxx flags to use? */
3239 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3241 if (cond_code == 0) { /* match! we will execute this branch */
3242 free(case_word); /* make future "word)" stop */
3250 if (rword == RES_CASEI) { /* inside of a case branch */
3252 continue; /* not matched yet, skip this pipe */
3255 /* Just pressing <enter> in shell should check for jobs.
3256 * OTOH, in non-interactive shell this is useless
3257 * and only leads to extra job checks */
3258 if (pi->num_cmds == 0) {
3259 if (G_interactive_fd)
3260 goto check_jobs_and_continue;
3264 /* After analyzing all keywords and conditions, we decided
3265 * to execute this pipe. NB: have to do checkjobs(NULL)
3266 * after run_pipe to collect any background children,
3267 * even if list execution is to be stopped. */
3268 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3271 #if ENABLE_HUSH_LOOPS
3272 G.flag_break_continue = 0;
3274 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3276 /* We only ran a builtin: rcode is already known
3277 * and we don't need to wait for anything. */
3278 G.last_return_code = rcode;
3279 debug_printf_exec(": builtin exitcode %d\n", rcode);
3280 check_and_run_traps(0);
3281 #if ENABLE_HUSH_LOOPS
3282 /* Was it "break" or "continue"? */
3283 if (G.flag_break_continue) {
3284 smallint fbc = G.flag_break_continue;
3285 /* We might fall into outer *loop*,
3286 * don't want to break it too */
3288 G.depth_break_continue--;
3289 if (G.depth_break_continue == 0)
3290 G.flag_break_continue = 0;
3291 /* else: e.g. "continue 2" should *break* once, *then* continue */
3292 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3293 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3294 goto check_jobs_and_break;
3295 /* "continue": simulate end of loop */
3300 } else if (pi->followup == PIPE_BG) {
3301 /* What does bash do with attempts to background builtins? */
3302 /* even bash 3.2 doesn't do that well with nested bg:
3303 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3304 * I'm NOT treating inner &'s as jobs */
3305 check_and_run_traps(0);
3307 if (G.run_list_level == 1)
3310 rcode = EXIT_SUCCESS;
3311 G.last_return_code = EXIT_SUCCESS;
3312 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3315 if (G.run_list_level == 1 && G_interactive_fd) {
3316 /* Waits for completion, then fg's main shell */
3317 rcode = checkjobs_and_fg_shell(pi);
3318 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3319 check_and_run_traps(0);
3322 { /* This one just waits for completion */
3323 rcode = checkjobs(pi);
3324 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3325 check_and_run_traps(0);
3327 G.last_return_code = rcode;
3331 /* Analyze how result affects subsequent commands */
3333 if (rword == RES_IF || rword == RES_ELIF)
3336 #if ENABLE_HUSH_LOOPS
3337 if (rword == RES_WHILE) {
3339 rcode = 0; /* "while false; do...done" - exitcode 0 */
3340 goto check_jobs_and_break;
3343 if (rword == RES_UNTIL) {
3345 check_jobs_and_break:
3352 check_jobs_and_continue:
3357 //// if (G.ctrl_z_flag) {
3358 //// /* ctrl-Z forked somewhere in the past, we are the child,
3359 //// * and now we completed running the list. Exit. */
3365 //// if (!G.run_list_level && G_interactive_fd) {
3366 //// signal(SIGTSTP, SIG_IGN);
3367 //// signal(SIGINT, SIG_IGN);
3370 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3371 #if ENABLE_HUSH_LOOPS
3376 #if ENABLE_HUSH_CASE
3382 /* Select which version we will use */
3383 static int run_and_free_list(struct pipe *pi)
3386 debug_printf_exec("run_and_free_list entered\n");
3388 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3389 rcode = run_list(pi);
3391 /* free_pipe_list has the side effect of clearing memory.
3392 * In the long run that function can be merged with run_list,
3393 * but doing that now would hobble the debugging effort. */
3394 free_pipe_list(pi, /* indent: */ 0);
3395 debug_printf_exec("run_and_free_list return %d\n", rcode);
3400 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3401 * as in "2>&1", that represents duplicating a file descriptor.
3402 * Return either -2 (syntax error), -1 (no &), or the number found.
3404 static int redirect_dup_num(struct in_str *input)
3406 int ch, d = 0, ok = 0;
3408 if (ch != '&') return -1;
3410 i_getch(input); /* get the & */
3414 return -3; /* "-" represents "close me" */
3416 while (isdigit(ch)) {
3417 d = d*10 + (ch-'0');
3424 bb_error_msg("ambiguous redirect");
3428 /* The src parameter allows us to peek forward to a possible &n syntax
3429 * for file descriptor duplication, e.g., "2>&1".
3430 * Return code is 0 normally, 1 if a syntax error is detected in src.
3431 * Resource errors (in xmalloc) cause the process to exit */
3432 static int setup_redirect(struct parse_context *ctx,
3435 struct in_str *input)
3437 struct command *command = ctx->command;
3438 struct redir_struct *redir;
3439 struct redir_struct **redirp;
3442 /* Check for a '2>&1' type redirect */
3443 dup_num = redirect_dup_num(input);
3445 return 1; /* syntax error */
3447 /* Create a new redir_struct and drop it onto the end of the linked list */
3448 redirp = &command->redirects;
3449 while ((redir = *redirp) != NULL) {
3450 redirp = &(redir->next);
3452 *redirp = redir = xzalloc(sizeof(*redir));
3453 /* redir->next = NULL; */
3454 /* redir->rd_filename = NULL; */
3455 redir->rd_type = style;
3456 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3458 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3460 redir->dup = dup_num;
3461 if (dup_num != -1) {
3462 /* Erik had a check here that the file descriptor in question
3463 * is legit; I postpone that to "run time"
3464 * A "-" representation of "close me" shows up as a -3 here */
3465 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3467 /* We do _not_ try to open the file that src points to,
3468 * since we need to return and let src be expanded first.
3469 * Set ctx->pending_redirect, so we know what to do at the
3470 * end of the next parsed word. */
3471 ctx->pending_redirect = redir;
3477 static struct pipe *new_pipe(void)
3480 pi = xzalloc(sizeof(struct pipe));
3481 /*pi->followup = 0; - deliberately invalid value */
3482 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3486 /* Command (member of a pipe) is complete. The only possible error here
3487 * is out of memory, in which case xmalloc exits. */
3488 static int done_command(struct parse_context *ctx)
3490 /* The command is really already in the pipe structure, so
3491 * advance the pipe counter and make a new, null command. */
3492 struct pipe *pi = ctx->pipe;
3493 struct command *command = ctx->command;
3496 if (command->group == NULL
3497 && command->argv == NULL
3498 && command->redirects == NULL
3500 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3501 return pi->num_cmds;
3504 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3506 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3509 /* Only real trickiness here is that the uncommitted
3510 * command structure is not counted in pi->num_cmds. */
3511 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3512 command = &pi->cmds[pi->num_cmds];
3513 memset(command, 0, sizeof(*command));
3515 ctx->command = command;
3516 /* but ctx->pipe and ctx->list_head remain unchanged */
3518 return pi->num_cmds; /* used only for 0/nonzero check */
3521 static void done_pipe(struct parse_context *ctx, pipe_style type)
3525 debug_printf_parse("done_pipe entered, followup %d\n", type);
3526 /* Close previous command */
3527 not_null = done_command(ctx);
3528 ctx->pipe->followup = type;
3529 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3530 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3531 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3533 /* Without this check, even just <enter> on command line generates
3534 * tree of three NOPs (!). Which is harmless but annoying.
3535 * IOW: it is safe to do it unconditionally.
3536 * RES_NONE case is for "for a in; do ..." (empty IN set)
3537 * to work, possibly other cases too. */
3538 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3540 debug_printf_parse("done_pipe: adding new pipe: "
3541 "not_null:%d ctx->ctx_res_w:%d\n",
3542 not_null, ctx->ctx_res_w);
3544 ctx->pipe->next = new_p;
3546 /* RES_THEN, RES_DO etc are "sticky" -
3547 * they remain set for commands inside if/while.
3548 * This is used to control execution.
3549 * RES_FOR and RES_IN are NOT sticky (needed to support
3550 * cases where variable or value happens to match a keyword):
3552 #if ENABLE_HUSH_LOOPS
3553 if (ctx->ctx_res_w == RES_FOR
3554 || ctx->ctx_res_w == RES_IN)
3555 ctx->ctx_res_w = RES_NONE;
3557 #if ENABLE_HUSH_CASE
3558 if (ctx->ctx_res_w == RES_MATCH)
3559 ctx->ctx_res_w = RES_CASEI;
3561 ctx->command = NULL; /* trick done_command below */
3562 /* Create the memory for command, roughly:
3563 * ctx->pipe->cmds = new struct command;
3564 * ctx->command = &ctx->pipe->cmds[0];
3568 debug_printf_parse("done_pipe return\n");
3571 static void initialize_context(struct parse_context *ctx)
3573 memset(ctx, 0, sizeof(*ctx));
3574 ctx->pipe = ctx->list_head = new_pipe();
3575 /* Create the memory for command, roughly:
3576 * ctx->pipe->cmds = new struct command;
3577 * ctx->command = &ctx->pipe->cmds[0];
3583 /* If a reserved word is found and processed, parse context is modified
3584 * and 1 is returned.
3587 struct reserved_combo {
3590 unsigned char assignment_flag;
3594 FLAG_END = (1 << RES_NONE ),
3596 FLAG_IF = (1 << RES_IF ),
3597 FLAG_THEN = (1 << RES_THEN ),
3598 FLAG_ELIF = (1 << RES_ELIF ),
3599 FLAG_ELSE = (1 << RES_ELSE ),
3600 FLAG_FI = (1 << RES_FI ),
3602 #if ENABLE_HUSH_LOOPS
3603 FLAG_FOR = (1 << RES_FOR ),
3604 FLAG_WHILE = (1 << RES_WHILE),
3605 FLAG_UNTIL = (1 << RES_UNTIL),
3606 FLAG_DO = (1 << RES_DO ),
3607 FLAG_DONE = (1 << RES_DONE ),
3608 FLAG_IN = (1 << RES_IN ),
3610 #if ENABLE_HUSH_CASE
3611 FLAG_MATCH = (1 << RES_MATCH),
3612 FLAG_ESAC = (1 << RES_ESAC ),
3614 FLAG_START = (1 << RES_XXXX ),
3617 static const struct reserved_combo* match_reserved_word(o_string *word)
3619 /* Mostly a list of accepted follow-up reserved words.
3620 * FLAG_END means we are done with the sequence, and are ready
3621 * to turn the compound list into a command.
3622 * FLAG_START means the word must start a new compound list.
3624 static const struct reserved_combo reserved_list[] = {
3626 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3627 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3628 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3629 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3630 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3631 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3633 #if ENABLE_HUSH_LOOPS
3634 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3635 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3636 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3637 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3638 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3639 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3641 #if ENABLE_HUSH_CASE
3642 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3643 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3646 const struct reserved_combo *r;
3648 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3649 if (strcmp(word->data, r->literal) == 0)
3654 static int reserved_word(o_string *word, struct parse_context *ctx)
3656 #if ENABLE_HUSH_CASE
3657 static const struct reserved_combo reserved_match = {
3658 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3661 const struct reserved_combo *r;
3663 r = match_reserved_word(word);
3667 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3668 #if ENABLE_HUSH_CASE
3669 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3670 /* "case word IN ..." - IN part starts first match part */
3671 r = &reserved_match;
3674 if (r->flag == 0) { /* '!' */
3675 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3676 syntax("! ! command");
3677 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3679 ctx->ctx_inverted = 1;
3682 if (r->flag & FLAG_START) {
3683 struct parse_context *old;
3684 old = xmalloc(sizeof(*old));
3685 debug_printf_parse("push stack %p\n", old);
3686 *old = *ctx; /* physical copy */
3687 initialize_context(ctx);
3689 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3691 ctx->ctx_res_w = RES_SNTX;
3694 ctx->ctx_res_w = r->res;
3695 ctx->old_flag = r->flag;
3696 if (ctx->old_flag & FLAG_END) {
3697 struct parse_context *old;
3698 done_pipe(ctx, PIPE_SEQ);
3699 debug_printf_parse("pop stack %p\n", ctx->stack);
3701 old->command->group = ctx->list_head;
3702 old->command->grp_type = GRP_NORMAL;
3704 o_addstr(&old->as_string, ctx->as_string.data);
3705 o_free_unsafe(&ctx->as_string);
3706 old->command->group_as_string = xstrdup(old->as_string.data);
3707 debug_printf_parse("pop, remembering as:'%s'\n",
3708 old->command->group_as_string);
3710 *ctx = *old; /* physical copy */
3713 word->o_assignment = r->assignment_flag;
3718 /* Word is complete, look at it and update parsing context.
3719 * Normal return is 0. Syntax errors return 1.
3720 * Note: on return, word is reset, but not o_free'd!
3722 static int done_word(o_string *word, struct parse_context *ctx)
3724 struct command *command = ctx->command;
3726 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3727 if (word->length == 0 && word->nonnull == 0) {
3728 debug_printf_parse("done_word return 0: true null, ignored\n");
3731 /* If this word wasn't an assignment, next ones definitely
3732 * can't be assignments. Even if they look like ones. */
3733 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3734 && word->o_assignment != WORD_IS_KEYWORD
3736 word->o_assignment = NOT_ASSIGNMENT;
3738 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3739 command->assignment_cnt++;
3740 word->o_assignment = MAYBE_ASSIGNMENT;
3743 if (ctx->pending_redirect) {
3744 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3745 * only if run as "bash", not "sh" */
3746 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3747 word->o_assignment = NOT_ASSIGNMENT;
3748 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3750 /* "{ echo foo; } echo bar" - bad */
3751 /* NB: bash allows e.g.:
3752 * if true; then { echo foo; } fi
3753 * while if false; then false; fi do break; done
3755 if (command->group) {
3757 debug_printf_parse("done_word return 1: syntax error, "
3758 "groups and arglists don't mix\n");
3762 #if ENABLE_HUSH_CASE
3763 if (ctx->ctx_dsemicolon
3764 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3766 /* already done when ctx_dsemicolon was set to 1: */
3767 /* ctx->ctx_res_w = RES_MATCH; */
3768 ctx->ctx_dsemicolon = 0;
3771 if (!command->argv /* if it's the first word... */
3772 #if ENABLE_HUSH_LOOPS
3773 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3774 && ctx->ctx_res_w != RES_IN
3777 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3778 if (reserved_word(word, ctx)) {
3780 debug_printf_parse("done_word return %d\n",
3781 (ctx->ctx_res_w == RES_SNTX));
3782 return (ctx->ctx_res_w == RES_SNTX);
3786 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3787 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3788 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3789 /* (otherwise it's known to be not empty and is already safe) */
3791 /* exclude "$@" - it can expand to no word despite "" */
3792 char *p = word->data;
3793 while (p[0] == SPECIAL_VAR_SYMBOL
3794 && (p[1] & 0x7f) == '@'
3795 && p[2] == SPECIAL_VAR_SYMBOL
3799 if (p == word->data || p[0] != '\0') {
3800 /* saw no "$@", or not only "$@" but some
3801 * real text is there too */
3802 /* insert "empty variable" reference, this makes
3803 * e.g. "", $empty"" etc to not disappear */
3804 o_addchr(word, SPECIAL_VAR_SYMBOL);
3805 o_addchr(word, SPECIAL_VAR_SYMBOL);
3808 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3809 debug_print_strings("word appended to argv", command->argv);
3813 ctx->pending_redirect = NULL;
3815 #if ENABLE_HUSH_LOOPS
3816 /* Force FOR to have just one word (variable name) */
3817 /* NB: basically, this makes hush see "for v in ..." syntax as if
3818 * as it is "for v; in ...". FOR and IN become two pipe structs
3820 if (ctx->ctx_res_w == RES_FOR) {
3821 //TODO: check that command->argv[0] is a valid variable name!
3822 done_pipe(ctx, PIPE_SEQ);
3825 #if ENABLE_HUSH_CASE
3826 /* Force CASE to have just one word */
3827 if (ctx->ctx_res_w == RES_CASE) {
3828 done_pipe(ctx, PIPE_SEQ);
3831 debug_printf_parse("done_word return 0\n");
3835 /* If a redirect is immediately preceded by a number, that number is
3836 * supposed to tell which file descriptor to redirect. This routine
3837 * looks for such preceding numbers. In an ideal world this routine
3838 * needs to handle all the following classes of redirects...
3839 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3840 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3841 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3842 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3843 * A -1 output from this program means no valid number was found, so the
3844 * caller should use the appropriate default for this redirection.
3846 static int redirect_opt_num(o_string *o)
3852 for (num = 0; num < o->length; num++) {
3853 if (!isdigit(o->data[num])) {
3857 num = atoi(o->data);
3863 #define parse_stream(pstring, input, end_trigger) \
3864 parse_stream(input, end_trigger)
3866 static struct pipe *parse_stream(char **pstring,
3867 struct in_str *input,
3869 static void parse_and_run_string(const char *s);
3871 #if ENABLE_HUSH_TICK
3872 static FILE *generate_stream_from_string(const char *s)
3875 int pid, channel[2];
3878 pid = BB_MMU ? fork() : vfork();
3880 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3882 if (pid == 0) { /* child */
3884 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
3886 /* Process substitution is not considered to be usual
3887 * 'command execution'.
3888 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3895 close(channel[0]); /* NB: close _first_, then move fd! */
3896 xmove_fd(channel[1], 1);
3897 /* Prevent it from trying to handle ctrl-z etc */
3898 USE_HUSH_JOB(G.run_list_level = 1;)
3900 reset_traps_to_defaults();
3901 parse_and_run_string(s);
3902 _exit(G.last_return_code);
3904 /* We re-execute after vfork on NOMMU. This makes this script safe:
3905 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
3906 * huge=`cat BIG` # was blocking here forever
3909 re_execute_shell(s);
3915 die_sleep = -1; /* restore tty pgrp on xfunc death */
3917 clean_up_after_re_execute();
3919 pf = fdopen(channel[0], "r");
3923 /* Return code is exit status of the process that is run. */
3924 static int process_command_subs(o_string *dest, const char *s)
3927 struct in_str pipe_str;
3930 pf = generate_stream_from_string(s);
3933 close_on_exec_on(fileno(pf));
3935 /* Now send results of command back into original context */
3936 setup_file_in_str(&pipe_str, pf);
3938 while ((ch = i_getch(&pipe_str)) != EOF) {
3944 o_addchr(dest, '\n');
3947 o_addQchr(dest, ch);
3950 debug_printf("done reading from pipe, pclose()ing\n");
3951 /* Note: we got EOF, and we just close the read end of the pipe.
3952 * We do not wait for the `cmd` child to terminate. bash and ash do.
3954 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
3955 * `false`; echo $? - bash outputs "1"
3958 debug_printf("closed FILE from child. return 0\n");
3963 static int parse_group(o_string *dest, struct parse_context *ctx,
3964 struct in_str *input, int ch)
3966 /* dest contains characters seen prior to ( or {.
3967 * Typically it's empty, but for function defs,
3968 * it contains function name (without '()'). */
3969 struct pipe *pipe_list;
3971 struct command *command = ctx->command;
3973 debug_printf_parse("parse_group entered\n");
3974 #if ENABLE_HUSH_FUNCTIONS
3975 if (ch == 'F') { /* function definition? */
3976 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3977 //command->fname = dest->data;
3978 command->grp_type = GRP_FUNCTION;
3979 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3980 memset(dest, 0, sizeof(*dest));
3983 if (command->argv /* word [word](... */
3984 || dest->length /* word(... */
3985 || dest->nonnull /* ""(... */
3988 debug_printf_parse("parse_group return 1: "
3989 "syntax error, groups and arglists don't mix\n");
3995 command->grp_type = GRP_SUBSHELL;
3999 char *as_string = NULL;
4001 pipe_list = parse_stream(&as_string, input, endch);
4004 o_addstr(&ctx->as_string, as_string);
4006 /* empty ()/{} or parse error? */
4007 if (!pipe_list || pipe_list == ERR_PTR) {
4012 debug_printf_parse("parse_group return 1: "
4013 "parse_stream returned %p\n", pipe_list);
4016 command->group = pipe_list;
4018 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4019 command->group_as_string = as_string;
4020 debug_printf_parse("end of group, remembering as:'%s'\n",
4021 command->group_as_string);
4024 debug_printf_parse("parse_group return 0\n");
4026 /* command remains "open", available for possible redirects */
4029 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4030 /* Subroutines for copying $(...) and `...` things */
4031 static void add_till_backquote(o_string *dest, struct in_str *input);
4033 static void add_till_single_quote(o_string *dest, struct in_str *input)
4036 int ch = i_getch(input);
4044 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4045 static void add_till_double_quote(o_string *dest, struct in_str *input)
4048 int ch = i_getch(input);
4051 if (ch == '\\') { /* \x. Copy both chars. */
4053 ch = i_getch(input);
4059 add_till_backquote(dest, input);
4063 //if (ch == '$') ...
4066 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4068 * "Within the backquoted style of command substitution, backslash
4069 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4070 * The search for the matching backquote shall be satisfied by the first
4071 * backquote found without a preceding backslash; during this search,
4072 * if a non-escaped backquote is encountered within a shell comment,
4073 * a here-document, an embedded command substitution of the $(command)
4074 * form, or a quoted string, undefined results occur. A single-quoted
4075 * or double-quoted string that begins, but does not end, within the
4076 * "`...`" sequence produces undefined results."
4078 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4080 static void add_till_backquote(o_string *dest, struct in_str *input)
4083 int ch = i_getch(input);
4086 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4087 int ch2 = i_getch(input);
4088 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4097 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4098 * quoting and nested ()s.
4099 * "With the $(command) style of command substitution, all characters
4100 * following the open parenthesis to the matching closing parenthesis
4101 * constitute the command. Any valid shell script can be used for command,
4102 * except a script consisting solely of redirections which produces
4103 * unspecified results."
4105 * echo $(echo '(TEST)' BEST) (TEST) BEST
4106 * echo $(echo 'TEST)' BEST) TEST) BEST
4107 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4109 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4113 int ch = i_getch(input);
4122 if (i_peek(input) == ')') {
4130 add_till_single_quote(dest, input);
4135 add_till_double_quote(dest, input);
4139 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4140 ch = i_getch(input);
4148 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4150 /* Return code: 0 for OK, 1 for syntax error */
4152 #define handle_dollar(as_string, dest, input) \
4153 handle_dollar(dest, input)
4155 static int handle_dollar(o_string *as_string,
4157 struct in_str *input)
4160 int ch = i_peek(input); /* first character after the $ */
4161 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4163 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4165 ch = i_getch(input);
4167 if (as_string) o_addchr(as_string, ch);
4170 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4172 debug_printf_parse(": '%c'\n", ch);
4173 o_addchr(dest, ch | quote_mask);
4176 if (!isalnum(ch) && ch != '_')
4178 ch = i_getch(input);
4180 if (as_string) o_addchr(as_string, ch);
4183 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4184 } else if (isdigit(ch)) {
4186 ch = i_getch(input);
4188 if (as_string) o_addchr(as_string, ch);
4190 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4191 debug_printf_parse(": '%c'\n", ch);
4192 o_addchr(dest, ch | quote_mask);
4193 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4194 } else switch (ch) {
4196 case '!': /* last bg pid */
4197 case '?': /* last exit code */
4198 case '#': /* number of args */
4199 case '*': /* args */
4200 case '@': /* args */
4201 goto make_one_char_var;
4203 bool first_char, all_digits;
4205 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4206 ch = i_getch(input);
4208 if (as_string) o_addchr(as_string, ch);
4210 /* XXX maybe someone will try to escape the '}' */
4215 ch = i_getch(input);
4217 if (as_string) o_addchr(as_string, ch);
4224 /* ${#var}: length of var contents */
4226 else if (isdigit(ch)) {
4233 && ( (all_digits && !isdigit(ch))
4234 || (!all_digits && !isalnum(ch) && ch != '_')
4237 /* handle parameter expansions
4238 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4243 case ':': /* null modifier */
4244 if (expansion == 0) {
4245 debug_printf_parse(": null modifier\n");
4250 #if 0 /* not implemented yet :( */
4251 case '#': /* remove prefix */
4252 case '%': /* remove suffix */
4253 if (expansion == 0) {
4254 debug_printf_parse(": remove suffix/prefix\n");
4260 case '-': /* default value */
4261 case '=': /* assign default */
4262 case '+': /* alternative */
4263 case '?': /* error indicate */
4264 debug_printf_parse(": parameter expansion\n");
4269 syntax("unterminated ${name}");
4270 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4275 debug_printf_parse(": '%c'\n", ch);
4276 o_addchr(dest, ch | quote_mask);
4280 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4283 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4288 ch = i_getch(input);
4290 if (as_string) o_addchr(as_string, ch);
4292 # if ENABLE_SH_MATH_SUPPORT
4293 if (i_peek(input) == '(') {
4294 ch = i_getch(input);
4296 if (as_string) o_addchr(as_string, ch);
4298 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4299 o_addchr(dest, /*quote_mask |*/ '+');
4303 add_till_closing_paren(dest, input, true);
4306 o_addstr(as_string, dest->data + pos);
4307 o_addchr(as_string, ')');
4308 o_addchr(as_string, ')');
4311 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4315 # if ENABLE_HUSH_TICK
4316 //int pos = dest->length;
4317 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4318 o_addchr(dest, quote_mask | '`');
4322 add_till_closing_paren(dest, input, false);
4325 o_addstr(as_string, dest->data + pos);
4326 o_addchr(as_string, '`');
4329 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4330 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4336 ch = i_getch(input);
4338 if (as_string) o_addchr(as_string, ch);
4341 if (isalnum(ch)) { /* it's $_name or $_123 */
4347 /* $_ Shell or shell script name; or last cmd name */
4348 /* $- Option flags set by set builtin or shell options (-i etc) */
4350 o_addQchr(dest, '$');
4352 debug_printf_parse("handle_dollar return 0\n");
4357 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4358 parse_stream_dquoted(dest, input, dquote_end)
4360 static int parse_stream_dquoted(o_string *as_string,
4362 struct in_str *input,
4369 ch = i_getch(input);
4371 if (as_string && ch != EOF)
4372 o_addchr(as_string, ch);
4374 if (ch == dquote_end) { /* may be only '"' or EOF */
4376 if (dest->o_assignment == NOT_ASSIGNMENT)
4377 dest->o_escape ^= 1;
4378 debug_printf_parse("parse_stream_dquoted return 0\n");
4382 syntax("unterminated \"");
4383 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4388 next = i_peek(input);
4390 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4391 ch, ch, dest->o_escape);
4395 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4399 * "The backslash retains its special meaning [in "..."]
4400 * only when followed by one of the following characters:
4401 * $, `, ", \, or <newline>. A double quote may be quoted
4402 * within double quotes by preceding it with a backslash.
4403 * If enabled, history expansion will be performed unless
4404 * an ! appearing in double quotes is escaped using
4405 * a backslash. The backslash preceding the ! is not removed."
4407 if (strchr("$`\"\\", next) != NULL) {
4408 o_addqchr(dest, i_getch(input));
4410 o_addqchr(dest, '\\');
4415 if (handle_dollar(as_string, dest, input) != 0) {
4416 debug_printf_parse("parse_stream_dquoted return 1: "
4417 "handle_dollar returned non-0\n");
4422 #if ENABLE_HUSH_TICK
4424 //int pos = dest->length;
4425 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4426 o_addchr(dest, 0x80 | '`');
4427 add_till_backquote(dest, input);
4428 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4429 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4433 o_addQchr(dest, ch);
4435 && (dest->o_assignment == MAYBE_ASSIGNMENT
4436 || dest->o_assignment == WORD_IS_KEYWORD)
4437 && is_assignment(dest->data)
4439 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4445 * Scan input until EOF or end_trigger char.
4446 * Return a list of pipes to execute, or NULL on EOF
4447 * or if end_trigger character is met.
4448 * On syntax error, exit is shell is not interactive,
4449 * reset parsing machinery and start parsing anew,
4450 * or return ERR_PTR.
4452 static struct pipe *parse_stream(char **pstring,
4453 struct in_str *input,
4456 struct parse_context ctx;
4457 o_string dest = NULL_O_STRING;
4460 /* Double-quote state is handled in the state variable is_in_dquote.
4461 * A single-quote triggers a bypass of the main loop until its mate is
4462 * found. When recursing, quote state is passed in via dest->o_escape.
4464 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4465 end_trigger ? : 'X');
4467 G.ifs = get_local_var_value("IFS");
4472 #if ENABLE_HUSH_INTERACTIVE
4473 input->promptmode = 0; /* PS1 */
4475 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4476 initialize_context(&ctx);
4480 const char *is_special;
4484 redir_type redir_style;
4487 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4490 /* We reached closing '"' */
4493 ch = i_getch(input);
4494 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4495 ch, ch, dest.o_escape);
4498 if (done_word(&dest, &ctx)) {
4502 done_pipe(&ctx, PIPE_SEQ);
4504 /* If we got nothing... */
4505 // TODO: test script consisting of just "&"
4506 if (pi->num_cmds == 0
4507 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4509 free_pipe_list(pi, 0);
4512 debug_printf_parse("parse_stream return %p\n", pi);
4514 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4516 *pstring = ctx.as_string.data;
4518 o_free_unsafe(&ctx.as_string);
4523 o_addchr(&ctx.as_string, ch);
4525 is_ifs = strchr(G.ifs, ch);
4526 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4527 "\\$\"" USE_HUSH_TICK("`") /* always special */
4530 if (!is_special && !is_ifs) { /* ordinary char */
4531 o_addQchr(&dest, ch);
4532 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4533 || dest.o_assignment == WORD_IS_KEYWORD)
4535 && is_assignment(dest.data)
4537 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4543 if (done_word(&dest, &ctx)) {
4547 #if ENABLE_HUSH_CASE
4548 /* "case ... in <newline> word) ..." -
4549 * newlines are ignored (but ';' wouldn't be) */
4550 if (ctx.command->argv == NULL
4551 && ctx.ctx_res_w == RES_MATCH
4556 /* Treat newline as a command separator. */
4557 done_pipe(&ctx, PIPE_SEQ);
4558 dest.o_assignment = MAYBE_ASSIGNMENT;
4560 /* note: if (is_ifs) continue;
4561 * will still trigger for us */
4564 if (end_trigger && end_trigger == ch) {
4565 //TODO: disallow "{ cmd }" without semicolon
4566 if (done_word(&dest, &ctx)) {
4569 done_pipe(&ctx, PIPE_SEQ);
4570 dest.o_assignment = MAYBE_ASSIGNMENT;
4571 /* Do we sit outside of any if's, loops or case's? */
4573 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4575 debug_printf_parse("parse_stream return %p: "
4576 "end_trigger char found\n",
4580 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4582 *pstring = ctx.as_string.data;
4584 o_free_unsafe(&ctx.as_string);
4586 return ctx.list_head;
4592 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4593 /* ch is a special char and thus this word
4594 * cannot be an assignment */
4595 dest.o_assignment = NOT_ASSIGNMENT;
4600 next = i_peek(input);
4605 if (dest.length == 0) {
4608 if (ch == EOF || ch == '\n')
4611 /* note: we do not add it to &ctx.as_string */
4614 //TODO: go back one char?
4615 o_addchr(&ctx.as_string, '\n');
4618 o_addQchr(&dest, ch);
4626 o_addchr(&dest, '\\');
4627 ch = i_getch(input);
4628 o_addchr(&dest, ch);
4630 o_addchr(&ctx.as_string, ch);
4634 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
4635 debug_printf_parse("parse_stream parse error: "
4636 "handle_dollar returned non-0\n");
4643 ch = i_getch(input);
4645 syntax("unterminated '");
4649 o_addchr(&ctx.as_string, ch);
4653 if (dest.o_assignment == NOT_ASSIGNMENT)
4654 o_addqchr(&dest, ch);
4656 o_addchr(&dest, ch);
4661 is_in_dquote ^= 1; /* invert */
4662 if (dest.o_assignment == NOT_ASSIGNMENT)
4665 #if ENABLE_HUSH_TICK
4667 //int pos = dest.length;
4668 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4669 o_addchr(&dest, '`');
4670 add_till_backquote(&dest, input);
4671 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4672 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4677 redir_fd = redirect_opt_num(&dest);
4678 if (done_word(&dest, &ctx)) {
4681 redir_style = REDIRECT_OVERWRITE;
4683 redir_style = REDIRECT_APPEND;
4684 ch = i_getch(input);
4686 o_addchr(&ctx.as_string, ch);
4690 else if (next == '(') {
4691 syntax(">(process) not supported");
4695 setup_redirect(&ctx, redir_fd, redir_style, input);
4698 redir_fd = redirect_opt_num(&dest);
4699 if (done_word(&dest, &ctx)) {
4702 redir_style = REDIRECT_INPUT;
4704 redir_style = REDIRECT_HEREIS;
4705 ch = i_getch(input);
4707 o_addchr(&ctx.as_string, ch);
4709 } else if (next == '>') {
4710 redir_style = REDIRECT_IO;
4711 ch = i_getch(input);
4713 o_addchr(&ctx.as_string, ch);
4717 else if (next == '(') {
4718 syntax("<(process) not supported");
4722 setup_redirect(&ctx, redir_fd, redir_style, input);
4725 #if ENABLE_HUSH_CASE
4728 if (done_word(&dest, &ctx)) {
4731 done_pipe(&ctx, PIPE_SEQ);
4732 #if ENABLE_HUSH_CASE
4733 /* Eat multiple semicolons, detect
4734 * whether it means something special */
4739 ch = i_getch(input);
4741 o_addchr(&ctx.as_string, ch);
4743 if (ctx.ctx_res_w == RES_CASEI) {
4744 ctx.ctx_dsemicolon = 1;
4745 ctx.ctx_res_w = RES_MATCH;
4751 /* We just finished a cmd. New one may start
4752 * with an assignment */
4753 dest.o_assignment = MAYBE_ASSIGNMENT;
4756 if (done_word(&dest, &ctx)) {
4760 ch = i_getch(input);
4762 o_addchr(&ctx.as_string, ch);
4764 done_pipe(&ctx, PIPE_AND);
4766 done_pipe(&ctx, PIPE_BG);
4770 if (done_word(&dest, &ctx)) {
4773 #if ENABLE_HUSH_CASE
4774 if (ctx.ctx_res_w == RES_MATCH)
4775 break; /* we are in case's "word | word)" */
4777 if (next == '|') { /* || */
4778 ch = i_getch(input);
4780 o_addchr(&ctx.as_string, ch);
4782 done_pipe(&ctx, PIPE_OR);
4784 /* we could pick up a file descriptor choice here
4785 * with redirect_opt_num(), but bash doesn't do it.
4786 * "echo foo 2| cat" yields "foo 2". */
4791 #if ENABLE_HUSH_CASE
4792 /* "case... in [(]word)..." - skip '(' */
4793 if (ctx.ctx_res_w == RES_MATCH
4794 && ctx.command->argv == NULL /* not (word|(... */
4795 && dest.length == 0 /* not word(... */
4796 && dest.nonnull == 0 /* not ""(... */
4801 #if ENABLE_HUSH_FUNCTIONS
4802 if (dest.length != 0 /* not just () but word() */
4803 && dest.nonnull == 0 /* not a"b"c() */
4804 && ctx.command->argv == NULL /* it's the first word */
4805 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4806 && i_peek(input) == ')'
4807 && !match_reserved_word(&dest)
4809 bb_error_msg("seems like a function definition");
4811 //if !BB_MMU o_addchr(&ctx.as_string...
4813 //TODO: do it properly.
4814 ch = i_getch(input);
4815 } while (ch == ' ' || ch == '\n');
4817 syntax("was expecting {");
4820 ch = 'F'; /* magic value */
4824 if (parse_group(&dest, &ctx, input, ch) != 0) {
4829 #if ENABLE_HUSH_CASE
4830 if (ctx.ctx_res_w == RES_MATCH)
4834 /* proper use of this character is caught by end_trigger:
4835 * if we see {, we call parse_group(..., end_trigger='}')
4836 * and it will match } earlier (not here). */
4837 syntax("unexpected } or )");
4841 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4847 struct parse_context *pctx;
4848 IF_HAS_KEYWORDS(struct parse_context *p2;)
4850 /* Clean up allocated tree.
4851 * Samples for finding leaks on syntax error recovery path.
4852 * Run them from interactive shell, watch pmap `pidof hush`.
4853 * while if false; then false; fi do break; done
4855 * while if false; then false; fi; do break; fi
4856 * Samples to catch leaks at execution:
4857 * while if (true | {true;}); then echo ok; fi; do break; done
4858 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4862 /* Update pipe/command counts,
4863 * otherwise freeing may miss some */
4864 done_pipe(pctx, PIPE_SEQ);
4865 debug_printf_clean("freeing list %p from ctx %p\n",
4866 pctx->list_head, pctx);
4867 debug_print_tree(pctx->list_head, 0);
4868 free_pipe_list(pctx->list_head, 0);
4869 debug_printf_clean("freed list %p\n", pctx->list_head);
4871 o_free_unsafe(&pctx->as_string);
4873 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4877 IF_HAS_KEYWORDS(pctx = p2;)
4878 } while (HAS_KEYWORDS && pctx);
4879 /* Free text, clear all dest fields */
4881 /* If we are not in top-level parse, we return,
4882 * our caller will propagate error.
4884 if (end_trigger != ';') {
4891 /* Discard cached input, force prompt */
4893 USE_HUSH_INTERACTIVE(input->promptme = 1;)
4898 /* Executing from string: eval, sh -c '...'
4899 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4900 * end_trigger controls how often we stop parsing
4901 * NUL: parse all, execute, return
4902 * ';': parse till ';' or newline, execute, repeat till EOF
4904 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4907 struct pipe *pipe_list;
4909 pipe_list = parse_stream(NULL, inp, end_trigger);
4910 if (!pipe_list) /* EOF */
4912 debug_print_tree(pipe_list, 0);
4913 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4914 run_and_free_list(pipe_list);
4918 static void parse_and_run_string(const char *s)
4920 struct in_str input;
4921 setup_string_in_str(&input, s);
4922 parse_and_run_stream(&input, '\0');
4925 static void parse_and_run_file(FILE *f)
4927 struct in_str input;
4928 setup_file_in_str(&input, f);
4929 parse_and_run_stream(&input, ';');
4932 /* Called a few times only (or even once if "sh -c") */
4933 static void block_signals(int second_time)
4938 mask = (1 << SIGQUIT);
4939 if (G_interactive_fd) {
4943 //TODO | (1 << SIGHUP)
4945 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
4950 G.non_DFL_mask = mask;
4953 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
4957 sigaddset(&G.blocked_set, sig);
4961 sigdelset(&G.blocked_set, SIGCHLD);
4963 sigprocmask(SIG_SETMASK, &G.blocked_set,
4964 second_time ? NULL : &G.inherited_set);
4965 /* POSIX allows shell to re-enable SIGCHLD
4966 * even if it was SIG_IGN on entry */
4967 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4969 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4974 static void maybe_set_to_sigexit(int sig)
4976 void (*handler)(int);
4977 /* non_DFL_mask'ed signals are, well, masked,
4978 * no need to set handler for them.
4980 if (!((G.non_DFL_mask >> sig) & 1)) {
4981 handler = signal(sig, sigexit);
4982 if (handler == SIG_IGN) /* oops... restore back to IGN! */
4983 signal(sig, handler);
4986 /* Set handlers to restore tty pgrp and exit */
4987 static void set_fatal_handlers(void)
4989 /* We _must_ restore tty pgrp on fatal signals */
4991 maybe_set_to_sigexit(SIGILL );
4992 maybe_set_to_sigexit(SIGFPE );
4993 maybe_set_to_sigexit(SIGBUS );
4994 maybe_set_to_sigexit(SIGSEGV);
4995 maybe_set_to_sigexit(SIGTRAP);
4996 } /* else: hush is perfect. what SEGV? */
4997 maybe_set_to_sigexit(SIGABRT);
4998 /* bash 3.2 seems to handle these just like 'fatal' ones */
4999 maybe_set_to_sigexit(SIGPIPE);
5000 maybe_set_to_sigexit(SIGALRM);
5001 //TODO: disable and move down when proper SIGHUP handling is added
5002 maybe_set_to_sigexit(SIGHUP );
5003 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5004 * if we aren't interactive... but in this case
5005 * we never want to restore pgrp on exit, and this fn is not called */
5006 /*maybe_set_to_sigexit(SIGTERM);*/
5007 /*maybe_set_to_sigexit(SIGINT );*/
5011 static int set_mode(const char cstate, const char mode)
5013 int state = (cstate == '-' ? 1 : 0);
5015 case 'n': G.fake_mode = state; break;
5016 case 'x': /*G.debug_mode = state;*/ break;
5017 default: return EXIT_FAILURE;
5019 return EXIT_SUCCESS;
5022 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5023 int hush_main(int argc, char **argv)
5025 static const struct variable const_shell_ver = {
5027 .varstr = (char*)hush_version_str,
5028 .max_len = 1, /* 0 can provoke free(name) */
5032 int signal_mask_is_inited = 0;
5035 struct variable *cur_var;
5038 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5039 G.last_return_code = EXIT_SUCCESS;
5041 G.argv0_for_re_execing = argv[0];
5043 /* Deal with HUSH_VERSION */
5044 G.shell_ver = const_shell_ver; /* copying struct here */
5045 G.top_var = &G.shell_ver;
5046 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5047 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5048 /* Initialize our shell local variables with the values
5049 * currently living in the environment */
5050 cur_var = G.top_var;
5053 char *value = strchr(*e, '=');
5054 if (value) { /* paranoia */
5055 cur_var->next = xzalloc(sizeof(*cur_var));
5056 cur_var = cur_var->next;
5057 cur_var->varstr = *e;
5058 cur_var->max_len = strlen(*e);
5059 cur_var->flg_export = 1;
5063 debug_printf_env("putenv '%s'\n", hush_version_str);
5064 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5065 #if ENABLE_FEATURE_EDITING
5066 G.line_input_state = new_line_input_t(FOR_SHELL);
5068 G.global_argc = argc;
5069 G.global_argv = argv;
5070 /* Initialize some more globals to non-zero values */
5072 #if ENABLE_HUSH_INTERACTIVE
5073 if (ENABLE_FEATURE_EDITING)
5074 cmdedit_set_initial_prompt();
5078 /* Shell is non-interactive at first. We need to call
5079 * block_signals(0) if we are going to execute "sh <script>",
5080 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5081 * If we later decide that we are interactive, we run block_signals(0)
5082 * (or re-run block_signals(1) if we ran block_signals(0) before)
5083 * in order to intercept (more) signals.
5087 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5089 opt = getopt(argc, argv, "c:xins"
5099 G.root_pid = getpid();
5100 G.global_argv = argv + optind;
5101 if (!argv[optind]) {
5102 /* -c 'script' (no params): prevent empty $0 */
5103 *--G.global_argv = argv[0];
5105 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5106 G.global_argc = argc - optind;
5107 block_signals(0); /* 0: called 1st time */
5108 parse_and_run_string(optarg);
5111 /* Well, we cannot just declare interactiveness,
5112 * we have to have some stuff (ctty, etc) */
5113 /* G_interactive_fd++; */
5116 /* "-s" means "read from stdin", but this is how we always
5117 * operate, so simply do nothing here. */
5121 G.root_pid = bb_strtou(optarg, &optarg, 16);
5123 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5125 G.last_return_code = bb_strtou(optarg, &optarg, 16);
5126 # if ENABLE_HUSH_LOOPS
5128 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5133 set_local_var(xstrdup(optarg), 0, opt == 'R');
5138 if (!set_mode('-', opt))
5142 fprintf(stderr, "Usage: sh [FILE]...\n"
5143 " or: sh -c command [args]...\n\n");
5149 } /* option parsing loop */
5152 G.root_pid = getpid();
5154 /* If we are login shell... */
5155 if (argv[0] && argv[0][0] == '-') {
5157 /* XXX what should argv be while sourcing /etc/profile? */
5158 debug_printf("sourcing /etc/profile\n");
5159 input = fopen_for_read("/etc/profile");
5160 if (input != NULL) {
5161 close_on_exec_on(fileno(input));
5162 block_signals(0); /* 0: called 1st time */
5163 signal_mask_is_inited = 1;
5164 parse_and_run_file(input);
5167 /* bash: after sourcing /etc/profile,
5168 * tries to source (in the given order):
5169 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5170 * stopping of first found. --noprofile turns this off.
5171 * bash also sources ~/.bash_logout on exit.
5172 * If called as sh, skips .bash_XXX files.
5179 * "bash <script>" (which is never interactive (unless -i?))
5180 * sources $BASH_ENV here (without scanning $PATH).
5181 * If called as sh, does the same but with $ENV.
5183 debug_printf("running script '%s'\n", argv[optind]);
5184 G.global_argv = argv + optind;
5185 G.global_argc = argc - optind;
5186 input = xfopen_for_read(argv[optind]);
5187 close_on_exec_on(fileno(input));
5188 if (!signal_mask_is_inited)
5189 block_signals(0); /* 0: called 1st time */
5190 parse_and_run_file(input);
5191 #if ENABLE_FEATURE_CLEAN_UP
5197 /* Up to here, shell was non-interactive. Now it may become one.
5198 * NB: don't forget to (re)run block_signals(0/1) as needed.
5201 /* A shell is interactive if the '-i' flag was given, or if all of
5202 * the following conditions are met:
5204 * no arguments remaining or the -s flag given
5205 * standard input is a terminal
5206 * standard output is a terminal
5207 * Refer to Posix.2, the description of the 'sh' utility.
5210 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5211 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5212 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5213 //TODO: "interactive" and "have job control" are two different things.
5214 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5215 //should stay on! Currently, we mix these into one.
5216 if (G.saved_tty_pgrp >= 0) {
5217 /* try to dup stdin to high fd#, >= 255 */
5218 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5219 if (G_interactive_fd < 0) {
5220 /* try to dup to any fd */
5221 G_interactive_fd = dup(STDIN_FILENO);
5222 if (G_interactive_fd < 0)
5224 G_interactive_fd = 0;
5226 // TODO: track & disallow any attempts of user
5227 // to (inadvertently) close/redirect it
5230 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5231 if (G_interactive_fd) {
5234 /* We are indeed interactive shell, and we will perform
5235 * job control. Setting up for that. */
5237 close_on_exec_on(G_interactive_fd);
5238 /* If we were run as 'hush &', sleep until we are
5239 * in the foreground (tty pgrp == our pgrp).
5240 * If we get started under a job aware app (like bash),
5241 * make sure we are now in charge so we don't fight over
5242 * who gets the foreground */
5244 shell_pgrp = getpgrp();
5245 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5246 if (G.saved_tty_pgrp == shell_pgrp)
5248 /* send TTIN to ourself (should stop us) */
5249 kill(- shell_pgrp, SIGTTIN);
5251 /* Block some signals */
5252 block_signals(signal_mask_is_inited);
5253 /* Set other signals to restore saved_tty_pgrp */
5254 set_fatal_handlers();
5255 /* Put ourselves in our own process group */
5256 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5257 /* Grab control of the terminal */
5258 tcsetpgrp(G_interactive_fd, getpid());
5259 /* -1 is special - makes xfuncs longjmp, not exit
5260 * (we reset die_sleep = 0 whereever we [v]fork) */
5262 if (setjmp(die_jmp)) {
5263 /* xfunc has failed! die die die */
5264 hush_exit(xfunc_error_retval);
5266 } else if (!signal_mask_is_inited) {
5267 block_signals(0); /* 0: called 1st time */
5268 } /* else: block_signals(0) was done before */
5269 #elif ENABLE_HUSH_INTERACTIVE
5270 /* No job control compiled in, only prompt/line editing */
5271 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5272 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5273 if (G_interactive_fd < 0) {
5274 /* try to dup to any fd */
5275 G_interactive_fd = dup(STDIN_FILENO);
5276 if (G_interactive_fd < 0)
5278 G_interactive_fd = 0;
5281 if (G_interactive_fd) {
5282 close_on_exec_on(G_interactive_fd);
5283 block_signals(signal_mask_is_inited);
5284 } else if (!signal_mask_is_inited) {
5288 /* We have interactiveness code disabled */
5289 if (!signal_mask_is_inited) {
5294 * if interactive but not a login shell, sources ~/.bashrc
5295 * (--norc turns this off, --rcfile <file> overrides)
5298 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5299 printf("\n\n%s hush - the humble shell\n", bb_banner);
5300 printf("Enter 'help' for a list of built-in commands.\n\n");
5303 parse_and_run_file(stdin);
5306 #if ENABLE_FEATURE_CLEAN_UP
5307 if (G.cwd != bb_msg_unknown)
5309 cur_var = G.top_var->next;
5311 struct variable *tmp = cur_var;
5312 if (!cur_var->max_len)
5313 free(cur_var->varstr);
5314 cur_var = cur_var->next;
5318 hush_exit(G.last_return_code);
5323 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5324 int lash_main(int argc, char **argv)
5326 //bb_error_msg("lash is deprecated, please use hush instead");
5327 return hush_main(argc, argv);
5335 static int builtin_trap(char **argv)
5342 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5346 /* No args: print all trapped. This isn't 100% correct as we
5347 * should be escaping the cmd so that it can be pasted back in
5349 for (i = 0; i < NSIG; ++i)
5351 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5352 return EXIT_SUCCESS;
5357 /* If first arg is decimal: reset all specified signals */
5358 sig = bb_strtou(*argv, NULL, 10);
5364 sig = get_signum(*argv++);
5365 if (sig < 0 || sig >= NSIG) {
5367 /* Mimic bash message exactly */
5368 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5373 G.traps[sig] = xstrdup(new_cmd);
5375 debug_printf("trap: setting SIG%s (%i) to '%s'",
5376 get_signame(sig), sig, G.traps[sig]);
5378 /* There is no signal for 0 (EXIT) */
5383 sigaddset(&G.blocked_set, sig);
5385 /* There was a trap handler, we are removing it
5386 * (if sig has non-DFL handling,
5387 * we don't need to do anything) */
5388 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5390 sigdelset(&G.blocked_set, sig);
5392 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5397 /* First arg is "-": reset all specified to default */
5398 /* First arg is "": ignore all specified */
5399 /* Everything else: execute first arg upon signal */
5401 bb_error_msg("trap: invalid arguments");
5402 return EXIT_FAILURE;
5404 if (NOT_LONE_DASH(*argv))
5410 static int builtin_true(char **argv UNUSED_PARAM)
5415 static int builtin_test(char **argv)
5422 return test_main(argc, argv - argc);
5425 static int builtin_echo(char **argv)
5432 return echo_main(argc, argv - argc);
5435 static int builtin_eval(char **argv)
5437 int rcode = EXIT_SUCCESS;
5440 char *str = expand_strvec_to_string(argv);
5442 * eval "echo Hi; done" ("done" is syntax error):
5443 * "echo Hi" will not execute too.
5445 parse_and_run_string(str);
5447 rcode = G.last_return_code;
5452 static int builtin_cd(char **argv)
5454 const char *newdir = argv[1];
5455 if (newdir == NULL) {
5456 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5457 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5459 newdir = getenv("HOME") ? : "/";
5461 if (chdir(newdir)) {
5462 /* Mimic bash message exactly */
5463 bb_perror_msg("cd: %s", newdir);
5464 return EXIT_FAILURE;
5467 return EXIT_SUCCESS;
5470 static int builtin_exec(char **argv)
5472 if (*++argv == NULL)
5473 return EXIT_SUCCESS; /* bash does this */
5478 // FIXME: if exec fails, bash does NOT exit! We do...
5479 pseudo_exec_argv(&dummy, argv, 0, NULL);
5484 static int builtin_exit(char **argv)
5486 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5487 //puts("exit"); /* bash does it */
5488 // TODO: warn if we have background jobs: "There are stopped jobs"
5489 // On second consecutive 'exit', exit anyway.
5490 if (*++argv == NULL)
5491 hush_exit(G.last_return_code);
5492 /* mimic bash: exit 123abc == exit 255 + error msg */
5493 xfunc_error_retval = 255;
5494 /* bash: exit -2 == exit 254, no error msg */
5495 hush_exit(xatoi(*argv) & 0xff);
5498 static int builtin_export(char **argv)
5500 if (*++argv == NULL) {
5502 // ash emits: export VAR='VAL'
5503 // bash: declare -x VAR="VAL"
5504 // (both also escape as needed (quotes, $, etc))
5509 return EXIT_SUCCESS;
5516 value = strchr(name, '=');
5518 /* They are exporting something without a =VALUE */
5519 struct variable *var;
5521 var = get_local_var(name);
5523 var->flg_export = 1;
5524 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5525 putenv(var->varstr);
5527 /* bash does not return an error when trying to export
5528 * an undefined variable. Do likewise. */
5531 set_local_var(xstrdup(name), 1, 0);
5534 return EXIT_SUCCESS;
5538 /* built-in 'fg' and 'bg' handler */
5539 static int builtin_fg_bg(char **argv)
5544 if (!G_interactive_fd)
5545 return EXIT_FAILURE;
5546 /* If they gave us no args, assume they want the last backgrounded task */
5548 for (pi = G.job_list; pi; pi = pi->next) {
5549 if (pi->jobid == G.last_jobid) {
5553 bb_error_msg("%s: no current job", argv[0]);
5554 return EXIT_FAILURE;
5556 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5557 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5558 return EXIT_FAILURE;
5560 for (pi = G.job_list; pi; pi = pi->next) {
5561 if (pi->jobid == jobnum) {
5565 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5566 return EXIT_FAILURE;
5568 // TODO: bash prints a string representation
5569 // of job being foregrounded (like "sleep 1 | cat")
5570 if (argv[0][0] == 'f') {
5571 /* Put the job into the foreground. */
5572 tcsetpgrp(G_interactive_fd, pi->pgrp);
5575 /* Restart the processes in the job */
5576 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5577 for (i = 0; i < pi->num_cmds; i++) {
5578 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5579 pi->cmds[i].is_stopped = 0;
5581 pi->stopped_cmds = 0;
5583 i = kill(- pi->pgrp, SIGCONT);
5585 if (errno == ESRCH) {
5586 delete_finished_bg_job(pi);
5587 return EXIT_SUCCESS;
5589 bb_perror_msg("kill (SIGCONT)");
5592 if (argv[0][0] == 'f') {
5594 return checkjobs_and_fg_shell(pi);
5596 return EXIT_SUCCESS;
5600 #if ENABLE_HUSH_HELP
5601 static int builtin_help(char **argv UNUSED_PARAM)
5603 const struct built_in_command *x;
5606 "Built-in commands:\n"
5607 "------------------\n");
5608 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5609 printf("%s\t%s\n", x->cmd, x->descr);
5612 return EXIT_SUCCESS;
5617 static int builtin_jobs(char **argv UNUSED_PARAM)
5620 const char *status_string;
5622 for (job = G.job_list; job; job = job->next) {
5623 if (job->alive_cmds == job->stopped_cmds)
5624 status_string = "Stopped";
5626 status_string = "Running";
5628 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5630 return EXIT_SUCCESS;
5634 static int builtin_pwd(char **argv UNUSED_PARAM)
5637 return EXIT_SUCCESS;
5640 static int builtin_read(char **argv)
5643 const char *name = argv[1] ? argv[1] : "REPLY";
5644 //TODO: check that argv[1] is a valid variable name
5646 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5647 return set_local_var(string, 0, 0);
5650 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5651 * built-in 'set' handler
5653 * set [-abCefhmnuvx] [-o option] [argument...]
5654 * set [+abCefhmnuvx] [+o option] [argument...]
5655 * set -- [argument...]
5658 * Implementations shall support the options in both their hyphen and
5659 * plus-sign forms. These options can also be specified as options to sh.
5661 * Write out all variables and their values: set
5662 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5663 * Turn on the -x and -v options: set -xv
5664 * Unset all positional parameters: set --
5665 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5666 * Set the positional parameters to the expansion of x, even if x expands
5667 * with a leading '-' or '+': set -- $x
5669 * So far, we only support "set -- [argument...]" and some of the short names.
5671 static int builtin_set(char **argv)
5674 char **pp, **g_argv;
5675 char *arg = *++argv;
5679 for (e = G.top_var; e; e = e->next)
5681 return EXIT_SUCCESS;
5685 if (!strcmp(arg, "--")) {
5690 if (arg[0] == '+' || arg[0] == '-') {
5691 for (n = 1; arg[n]; ++n)
5692 if (set_mode(arg[0], arg[n]))
5698 } while ((arg = *++argv) != NULL);
5699 /* Now argv[0] is 1st argument */
5701 /* Only reset global_argv if we didn't process anything */
5703 return EXIT_SUCCESS;
5706 /* NB: G.global_argv[0] ($0) is never freed/changed */
5707 g_argv = G.global_argv;
5708 if (G.global_args_malloced) {
5714 G.global_args_malloced = 1;
5715 pp = xzalloc(sizeof(pp[0]) * 2);
5716 pp[0] = g_argv[0]; /* retain $0 */
5719 /* This realloc's G.global_argv */
5720 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5727 return EXIT_SUCCESS;
5729 /* Nothing known, so abort */
5731 bb_error_msg("set: %s: invalid option", arg);
5732 return EXIT_FAILURE;
5735 static int builtin_shift(char **argv)
5741 if (n >= 0 && n < G.global_argc) {
5742 if (G.global_args_malloced) {
5745 free(G.global_argv[m++]);
5748 memmove(&G.global_argv[1], &G.global_argv[n+1],
5749 G.global_argc * sizeof(G.global_argv[0]));
5750 return EXIT_SUCCESS;
5752 return EXIT_FAILURE;
5755 static int builtin_source(char **argv)
5759 if (*++argv == NULL)
5760 return EXIT_FAILURE;
5762 /* XXX search through $PATH is missing */
5763 input = fopen_or_warn(*argv, "r");
5765 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
5766 return EXIT_FAILURE;
5768 close_on_exec_on(fileno(input));
5770 /* Now run the file */
5772 /* XXX argv and argc are broken; need to save old G.global_argv
5773 * (pointer only is OK!) on this stack frame,
5774 * set G.global_argv=argv+1, recurse, and restore. */
5775 parse_and_run_file(input);
5777 return G.last_return_code;
5780 static int builtin_umask(char **argv)
5783 const char *arg = argv[1];
5785 //TODO: umask may take chmod-like symbolic masks
5786 new_umask = bb_strtou(arg, NULL, 8);
5788 //Message? bash examples:
5789 //bash: umask: 'q': invalid symbolic mode operator
5790 //bash: umask: 999: octal number out of range
5791 return EXIT_FAILURE;
5794 new_umask = umask(0);
5795 printf("%.3o\n", (unsigned) new_umask);
5796 /* fall through and restore new_umask which we set to 0 */
5799 return EXIT_SUCCESS;
5802 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5803 static int builtin_unset(char **argv)
5809 return EXIT_SUCCESS;
5812 if (argv[0][0] == '-') {
5813 switch (argv[0][1]) {
5819 bb_error_msg("unset: %s: invalid option", *argv);
5820 return EXIT_FAILURE;
5822 //TODO: disallow "unset -vf ..." too
5829 if (unset_local_var(*argv)) {
5830 /* unset <nonexistent_var> doesn't fail.
5831 * Error is when one tries to unset RO var.
5832 * Message was printed by unset_local_var. */
5836 #if ENABLE_HUSH_FUNCTIONS
5838 unset_local_func(*argv);
5846 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5847 static int builtin_wait(char **argv)
5849 int ret = EXIT_SUCCESS;
5852 if (*++argv == NULL) {
5853 /* Don't care about wait results */
5854 /* Note 1: must wait until there are no more children */
5855 /* Note 2: must be interruptible */
5857 * $ sleep 3 & sleep 6 & wait
5862 * $ sleep 3 & sleep 6 & wait
5866 * ^C <-- after ~4 sec from keyboard
5869 sigaddset(&G.blocked_set, SIGCHLD);
5870 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5873 if (errno == ECHILD)
5875 /* Wait for SIGCHLD or any other signal of interest */
5876 /* sigtimedwait with infinite timeout: */
5877 sig = sigwaitinfo(&G.blocked_set, NULL);
5879 sig = check_and_run_traps(sig);
5880 if (sig && sig != SIGCHLD) { /* see note 2 */
5886 sigdelset(&G.blocked_set, SIGCHLD);
5887 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5891 /* This is probably buggy wrt interruptible-ness */
5893 pid_t pid = bb_strtou(*argv, NULL, 10);
5895 /* mimic bash message */
5896 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5897 return EXIT_FAILURE;
5899 if (waitpid(pid, &status, 0) == pid) {
5900 if (WIFSIGNALED(status))
5901 ret = 128 + WTERMSIG(status);
5902 else if (WIFEXITED(status))
5903 ret = WEXITSTATUS(status);
5907 bb_perror_msg("wait %s", *argv);
5916 #if ENABLE_HUSH_LOOPS
5917 static int builtin_break(char **argv)
5919 if (G.depth_of_loop == 0) {
5920 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5921 return EXIT_SUCCESS; /* bash compat */
5923 G.flag_break_continue++; /* BC_BREAK = 1 */
5924 G.depth_break_continue = 1;
5926 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5927 if (errno || !G.depth_break_continue || argv[2]) {
5928 bb_error_msg("%s: bad arguments", argv[0]);
5929 G.flag_break_continue = BC_BREAK;
5930 G.depth_break_continue = UINT_MAX;
5933 if (G.depth_of_loop < G.depth_break_continue)
5934 G.depth_break_continue = G.depth_of_loop;
5935 return EXIT_SUCCESS;
5938 static int builtin_continue(char **argv)
5940 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5941 return builtin_break(argv);