1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * <(list) and >(list) Process Substitution
42 * Here Documents ( << word )
45 * Parameter Expansion for substring processing ${var#word} ${var%word}
47 * Bash stuff maybe optional enable:
48 * &> and >& redirection of stdout+stderr
50 * reserved words: [[ ]] function select
51 * substrings ${var:1:5}
54 * job handling woefully incomplete and buggy (improved --vda)
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * change { and } from special chars to reserved words
58 * builtins: return, trap, ulimit
59 * test magic exec with redirection only
60 * follow IFS rules more precisely, including update semantics
61 * figure out what to do with backslash-newline
62 * propagate syntax errors, die on resource errors?
63 * continuation lines, both explicit and implicit - done?
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
68 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
70 //#include "applet_tables.h" doesn't work
72 /* #include <dmalloc.h> */
78 #ifdef WANT_TO_TEST_NOMMU
83 # define USE_FOR_NOMMU(...) __VA_ARGS__
84 # define USE_FOR_MMU(...)
87 #define HUSH_VER_STR "0.93"
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
197 static void debug_print_strings(const char *prefix, char **vv)
199 fprintf(stderr, "%s:\n", prefix);
201 fprintf(stderr, " '%s'\n", *vv++);
204 #define debug_print_strings(prefix, vv) ((void)0)
208 * Leak hunting. Use hush_leaktool.sh for post-processing.
210 #ifdef FOR_HUSH_LEAKTOOL
211 static void *xxmalloc(int lineno, size_t size)
213 void *ptr = xmalloc((size + 0xff) & ~0xff);
214 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
217 static void *xxrealloc(int lineno, void *ptr, size_t size)
219 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
220 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
223 static char *xxstrdup(int lineno, const char *str)
225 char *ptr = xstrdup(str);
226 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
229 static void xxfree(void *ptr)
231 fdprintf(2, "free %p\n", ptr);
234 #define xmalloc(s) xxmalloc(__LINE__, s)
235 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
236 #define xstrdup(s) xxstrdup(__LINE__, s)
237 #define free(p) xxfree(p)
241 #define ERR_PTR ((void*)(long)1)
243 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
245 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
247 #define SPECIAL_VAR_SYMBOL 3
249 typedef enum redir_type {
251 REDIRECT_OVERWRITE = 2,
257 /* The descrip member of this structure is only used to make
258 * debugging output pretty */
259 static const struct {
261 signed char default_fd;
265 { O_RDONLY, 0, "<" },
266 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
267 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
268 { O_RDONLY, -1, "<<" },
272 typedef enum pipe_style {
279 typedef enum reserved_style {
288 #if ENABLE_HUSH_LOOPS
295 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
300 /* two pseudo-keywords support contrived "case" syntax: */
301 RES_MATCH , /* "word)" */
302 RES_CASEI , /* "this command is inside CASE" */
309 typedef struct o_string {
311 int length; /* position where data is appended */
313 /* Protect newly added chars against globbing
314 * (by prepending \ to *, ?, [, \) */
318 smallint has_empty_slot;
319 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
322 MAYBE_ASSIGNMENT = 0,
323 DEFINITELY_ASSIGNMENT = 1,
325 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
327 /* Used for initialization: o_string foo = NULL_O_STRING; */
328 #define NULL_O_STRING { NULL }
330 /* I can almost use ordinary FILE*. Is open_memstream() universally
331 * available? Where is it documented? */
332 typedef struct in_str {
334 /* eof_flag=1: last char in ->p is really an EOF */
335 char eof_flag; /* meaningless if ->p == NULL */
337 #if ENABLE_HUSH_INTERACTIVE
339 smallint promptmode; /* 0: PS1, 1: PS2 */
342 int (*get) (struct in_str *);
343 int (*peek) (struct in_str *);
345 #define i_getch(input) ((input)->get(input))
346 #define i_peek(input) ((input)->peek(input))
348 struct redir_struct {
349 struct redir_struct *next;
350 char *rd_filename; /* filename */
351 int fd; /* file descriptor being redirected */
352 int dup; /* -1, or file descriptor being duplicated */
353 smallint /*enum redir_type*/ rd_type;
357 pid_t pid; /* 0 if exited */
358 int assignment_cnt; /* how many argv[i] are assignments? */
359 smallint is_stopped; /* is the command currently running? */
360 smallint grp_type; /* GRP_xxx */
361 struct pipe *group; /* if non-NULL, this "command" is { list },
362 * ( list ), or a compound statement */
364 char *group_as_string;
366 char **argv; /* command name and arguments */
367 struct redir_struct *redirects; /* I/O redirections */
369 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
370 * and on execution these are substituted with their values.
371 * Substitution can make _several_ words out of one argv[n]!
372 * Example: argv[0]=='.^C*^C.' here: echo .$*.
373 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
376 #define GRP_SUBSHELL 1
377 #if ENABLE_HUSH_FUNCTIONS
378 #define GRP_FUNCTION 2
383 int num_cmds; /* total number of commands in job */
384 int alive_cmds; /* number of commands running (not exited) */
385 int stopped_cmds; /* number of commands alive, but stopped */
387 int jobid; /* job number */
388 pid_t pgrp; /* process group ID for the job */
389 char *cmdtext; /* name of job */
391 struct command *cmds; /* array of commands in pipe */
392 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
393 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
394 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
397 /* This holds pointers to the various results of parsing */
398 struct parse_context {
399 /* linked list of pipes */
400 struct pipe *list_head;
401 /* last pipe (being constructed right now) */
403 /* last command in pipe (being constructed right now) */
404 struct command *command;
405 /* last redirect in command->redirects list */
406 struct redir_struct *pending_redirect;
412 smallint ctx_inverted; /* "! cmd | cmd" */
414 smallint ctx_dsemicolon; /* ";;" seen */
416 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
418 /* group we are enclosed in:
419 * example: "if pipe1; pipe2; then pipe3; fi"
420 * when we see "if" or "then", we malloc and copy current context,
421 * and make ->stack point to it. then we parse pipeN.
422 * when closing "then" / fi" / whatever is found,
423 * we move list_head into ->stack->command->group,
424 * copy ->stack into current context, and delete ->stack.
425 * (parsing of { list } and ( list ) doesn't use this method)
427 struct parse_context *stack;
431 /* On program start, environ points to initial environment.
432 * putenv adds new pointers into it, unsetenv removes them.
433 * Neither of these (de)allocates the strings.
434 * setenv allocates new strings in malloc space and does putenv,
435 * and thus setenv is unusable (leaky) for shell's purposes */
436 #define setenv(...) setenv_is_leaky_dont_use()
438 struct variable *next;
439 char *varstr; /* points to "name=" portion */
440 int max_len; /* if > 0, name is part of initial env; else name is malloced */
441 smallint flg_export; /* putenv should be done on this var */
442 smallint flg_read_only;
451 /* "Globals" within this file */
452 /* Sorted roughly by size (smaller offsets == smaller code) */
454 #if ENABLE_HUSH_INTERACTIVE
455 /* 'interactive_fd' is a fd# open to ctty, if we have one
456 * _AND_ if we decided to act interactively */
460 #define G_interactive_fd (G.interactive_fd)
462 #define G_interactive_fd 0
464 #if ENABLE_FEATURE_EDITING
465 line_input_t *line_input_state;
471 pid_t saved_tty_pgrp;
473 struct pipe *job_list;
474 struct pipe *toplevel_list;
475 //// smallint ctrl_z_flag;
477 smallint flag_SIGINT;
478 #if ENABLE_HUSH_LOOPS
479 smallint flag_break_continue;
482 /* These four support $?, $#, and $1 */
483 smalluint last_return_code;
484 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
485 smalluint global_args_malloced;
486 /* how many non-NULL argv's we have. NB: $# + 1 */
490 char *argv0_for_re_execing;
491 char **argv_from_re_execing;
493 #if ENABLE_HUSH_LOOPS
494 unsigned depth_break_continue;
495 unsigned depth_of_loop;
499 struct variable *top_var; /* = &G.shell_ver (set in main()) */
500 struct variable shell_ver;
501 /* Signal and trap handling */
502 // unsigned count_SIGCHLD;
503 // unsigned handled_SIGCHLD;
504 /* which signals have non-DFL handler (even with no traps set)? */
505 unsigned non_DFL_mask;
506 char **traps; /* char *traps[NSIG] */
507 sigset_t blocked_set;
508 sigset_t inherited_set;
509 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
510 #if ENABLE_FEATURE_SH_STANDALONE
511 struct nofork_save_area nofork_save;
514 sigjmp_buf toplevel_jb;
517 #define G (*ptr_to_globals)
518 /* Not #defining name to G.name - this quickly gets unwieldy
519 * (too many defines). Also, I actually prefer to see when a variable
520 * is global, thus "G." prefix is a useful hint */
521 #define INIT_G() do { \
522 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
526 /* Function prototypes for builtins */
527 static int builtin_cd(char **argv);
528 static int builtin_echo(char **argv);
529 static int builtin_eval(char **argv);
530 static int builtin_exec(char **argv);
531 static int builtin_exit(char **argv);
532 static int builtin_export(char **argv);
534 static int builtin_fg_bg(char **argv);
535 static int builtin_jobs(char **argv);
538 static int builtin_help(char **argv);
540 static int builtin_pwd(char **argv);
541 static int builtin_read(char **argv);
542 static int builtin_test(char **argv);
543 static int builtin_trap(char **argv);
544 static int builtin_true(char **argv);
545 static int builtin_set(char **argv);
546 static int builtin_shift(char **argv);
547 static int builtin_source(char **argv);
548 static int builtin_umask(char **argv);
549 static int builtin_unset(char **argv);
550 static int builtin_wait(char **argv);
551 #if ENABLE_HUSH_LOOPS
552 static int builtin_break(char **argv);
553 static int builtin_continue(char **argv);
556 /* Table of built-in functions. They can be forked or not, depending on
557 * context: within pipes, they fork. As simple commands, they do not.
558 * When used in non-forking context, they can change global variables
559 * in the parent shell process. If forked, of course they cannot.
560 * For example, 'unset foo | whatever' will parse and run, but foo will
561 * still be set at the end. */
562 struct built_in_command {
564 int (*function)(char **argv);
567 #define BLTIN(cmd, func, help) { cmd, func, help }
569 #define BLTIN(cmd, func, help) { cmd, func }
573 /* For now, echo and test are unconditionally enabled.
574 * Maybe make it configurable? */
575 static const struct built_in_command bltins[] = {
576 BLTIN("." , builtin_source , "Run commands in a file"),
577 BLTIN(":" , builtin_true , "No-op"),
578 BLTIN("[" , builtin_test , "Test condition"),
580 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
582 #if ENABLE_HUSH_LOOPS
583 BLTIN("break" , builtin_break , "Exit from a loop"),
585 BLTIN("cd" , builtin_cd , "Change directory"),
586 #if ENABLE_HUSH_LOOPS
587 BLTIN("continue", builtin_continue, "Start new loop iteration"),
589 BLTIN("echo" , builtin_echo , "Write to stdout"),
590 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
591 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
592 BLTIN("exit" , builtin_exit , "Exit"),
593 BLTIN("export" , builtin_export , "Set environment variable"),
595 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
598 BLTIN("help" , builtin_help , "List shell built-in commands"),
601 BLTIN("jobs" , builtin_jobs , "List active jobs"),
603 BLTIN("pwd" , builtin_pwd , "Print current directory"),
604 BLTIN("read" , builtin_read , "Input environment variable"),
605 // BLTIN("return" , builtin_return , "Return from a function"),
606 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
607 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
608 BLTIN("test" , builtin_test , "Test condition"),
609 BLTIN("trap" , builtin_trap , "Trap signals"),
610 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
611 BLTIN("umask" , builtin_umask , "Set file creation mask"),
612 BLTIN("unset" , builtin_unset , "Unset environment variable"),
613 BLTIN("wait" , builtin_wait , "Wait for process"),
617 static void maybe_die(const char *notice, const char *msg)
619 /* Was using fancy stuff:
620 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
621 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
622 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
623 #if ENABLE_HUSH_INTERACTIVE
624 if (G_interactive_fd)
627 fp(msg ? "%s: %s" : notice, notice, msg);
630 #define syntax(msg) maybe_die("syntax error", msg);
632 /* Debug -- trick gcc to expand __LINE__ and convert to string */
633 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
634 #define _syntax(msg, line) __syntax(msg, line)
635 #define syntax(msg) _syntax(msg, __LINE__)
639 static int glob_needed(const char *s)
644 if (*s == '*' || *s == '[' || *s == '?')
651 static int is_assignment(const char *s)
653 if (!s || !(isalpha(*s) || *s == '_'))
656 while (isalnum(*s) || *s == '_')
661 /* Replace each \x with x in place, return ptr past NUL. */
662 static char *unbackslash(char *src)
668 if ((*dst++ = *src++) == '\0')
674 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
695 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
696 v[count1 + count2] = NULL;
699 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
703 static char **add_string_to_strings(char **strings, char *add)
708 return add_strings_to_strings(strings, v, /*dup:*/ 0);
711 static void putenv_all(char **strings)
716 debug_printf_env("putenv '%s'\n", *strings);
721 static char **putenv_all_and_save_old(char **strings)
731 eq = strchr(*strings, '=');
734 v = getenv(*strings);
737 /* v points to VAL in VAR=VAL, go back to VAR */
738 v -= (eq - *strings) + 1;
739 old = add_string_to_strings(old, v);
748 static void free_strings_and_unsetenv(char **strings, int unset)
758 debug_printf_env("unsetenv '%s'\n", *v);
766 static void free_strings(char **strings)
768 free_strings_and_unsetenv(strings, 0);
772 /* Basic theory of signal handling in shell
773 * ========================================
774 * This does not describe what hush does, rather, it is current understanding
775 * what it _should_ do. If it doesn't, it's a bug.
776 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
778 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
779 * is finished or backgrounded. It is the same in interactive and
780 * non-interactive shells, and is the same regardless of whether
781 * a user trap handler is installed or a shell special one is in effect.
782 * ^C or ^Z from keyboard seem to execute "at once" because it usually
783 * backgrounds (i.e. stops) or kills all members of currently running
786 * Wait builtin in interruptible by signals for which user trap is set
787 * or by SIGINT in interactive shell.
789 * Trap handlers will execute even within trap handlers. (right?)
791 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
793 * If job control is off, backgrounded commands ("cmd &")
794 * have SIGINT, SIGQUIT set to SIG_IGN.
796 * Commands run in command substitution ("`cmd`")
797 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
799 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
800 * by the shell from its parent.
802 * Siganls which differ from SIG_DFL action
803 * (note: child (i.e., [v]forked) shell is not an interactive shell):
806 * SIGTERM (interactive): ignore
807 * SIGHUP (interactive):
808 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
809 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
810 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
811 * that all pipe members are stopped) (right?)
812 * SIGINT (interactive): wait for last pipe, ignore the rest
813 * of the command line, show prompt. NB: ^C does not send SIGINT
814 * to interactive shell while shell is waiting for a pipe,
815 * since shell is bg'ed (is not in foreground process group).
816 * (check/expand this)
817 * Example 1: this waits 5 sec, but does not execute ls:
818 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
819 * Example 2: this does not wait and does not execute ls:
820 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
821 * Example 3: this does not wait 5 sec, but executes ls:
822 * "sleep 5; ls -l" + press ^C
824 * (What happens to signals which are IGN on shell start?)
825 * (What happens with signal mask on shell start?)
827 * Implementation in hush
828 * ======================
829 * We use in-kernel pending signal mask to determine which signals were sent.
830 * We block all signals which we don't want to take action immediately,
831 * i.e. we block all signals which need to have special handling as described
832 * above, and all signals which have traps set.
833 * After each pipe execution, we extract any pending signals via sigtimedwait()
836 * unsigned non_DFL_mask: a mask of such "special" signals
837 * sigset_t blocked_set: current blocked signal set
840 * clear bit in blocked_set unless it is also in non_DFL_mask
841 * "trap 'cmd' SIGxxx":
842 * set bit in blocked_set (even if 'cmd' is '')
843 * after [v]fork, if we plan to be a shell:
844 * nothing for {} child shell (say, "true | { true; true; } | true")
845 * unset all traps if () shell. [TODO]
846 * after [v]fork, if we plan to exec:
847 * POSIX says pending signal mask is cleared in child - no need to clear it.
848 * Restore blocked signal set to one inherited by shell just prior to exec.
850 * Note: as a result, we do not use signal handlers much. The only uses
851 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
852 * and to restore tty pgrp on signal-induced exit.
855 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
857 // G.count_SIGCHLD++;
860 static int check_and_run_traps(int sig)
862 static const struct timespec zero_timespec = { 0, 0 };
863 smalluint save_rcode;
869 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
874 if (G.traps && G.traps[sig]) {
875 if (G.traps[sig][0]) {
876 /* We have user-defined handler */
877 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
878 save_rcode = G.last_return_code;
881 G.last_return_code = save_rcode;
882 } /* else: "" trap, ignoring signal */
885 /* not a trap: special action */
888 // G.count_SIGCHLD++;
897 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
905 /* Restores tty foreground process group, and exits.
906 * May be called as signal handler for fatal signal
907 * (will faithfully resend signal to itself, producing correct exit state)
908 * or called directly with -EXITCODE.
909 * We also call it if xfunc is exiting. */
910 static void sigexit(int sig) NORETURN;
911 static void sigexit(int sig)
913 /* Disable all signals: job control, SIGPIPE, etc. */
914 sigprocmask_allsigs(SIG_BLOCK);
916 /* Careful: we can end up here after [v]fork. Do not restore
917 * tty pgrp then, only top-level shell process does that */
918 if (G_interactive_fd && getpid() == G.root_pid)
919 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
921 /* Not a signal, just exit */
925 kill_myself_with_sig(sig); /* does not return */
929 /* Restores tty foreground process group, and exits. */
930 static void hush_exit(int exitcode) NORETURN;
931 static void hush_exit(int exitcode)
933 if (G.traps && G.traps[0] && G.traps[0][0]) {
934 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
935 //TODO: do we need to prevent recursion?
941 fflush(NULL); /* flush all streams */
942 sigexit(- (exitcode & 0xff));
949 static const char *set_cwd(void)
951 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
952 * we must not try to free(bb_msg_unknown) */
953 if (G.cwd == bb_msg_unknown)
955 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
957 G.cwd = bb_msg_unknown;
962 /* Get/check local shell variables */
963 static struct variable *get_local_var(const char *name)
965 struct variable *cur;
971 for (cur = G.top_var; cur; cur = cur->next) {
972 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
978 static const char *get_local_var_value(const char *src)
980 struct variable *var = get_local_var(src);
982 return strchr(var->varstr, '=') + 1;
986 /* str holds "NAME=VAL" and is expected to be malloced.
987 * We take ownership of it.
991 * -1: if NAME is set, leave export status alone
992 * if NAME is not set, do not export
993 * flg_read_only is set only when we handle -R var=val
996 #define set_local_var(str, flg_export, flg_read_only) \
997 set_local_var(str, flg_export)
999 static int set_local_var(char *str, int flg_export, int flg_read_only)
1001 struct variable *cur;
1005 value = strchr(str, '=');
1006 if (!value) { /* not expected to ever happen? */
1011 name_len = value - str + 1; /* including '=' */
1012 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1014 if (strncmp(cur->varstr, str, name_len) != 0) {
1016 /* Bail out. Note that now cur points
1017 * to last var in linked list */
1023 /* We found an existing var with this name */
1025 if (cur->flg_read_only) {
1029 bb_error_msg("%s: readonly variable", str);
1033 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1034 unsetenv(str); /* just in case */
1036 if (strcmp(cur->varstr, str) == 0) {
1041 if (cur->max_len >= strlen(str)) {
1042 /* This one is from startup env, reuse space */
1043 strcpy(cur->varstr, str);
1046 /* max_len == 0 signifies "malloced" var, which we can
1047 * (and has to) free */
1051 goto set_str_and_exp;
1054 /* Not found - create next variable struct */
1055 cur->next = xzalloc(sizeof(*cur));
1061 cur->flg_read_only = flg_read_only;
1064 if (flg_export == 1)
1065 cur->flg_export = 1;
1066 if (cur->flg_export) {
1067 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1068 return putenv(cur->varstr);
1073 static int unset_local_var(const char *name)
1075 struct variable *cur;
1076 struct variable *prev = prev; /* for gcc */
1080 return EXIT_SUCCESS;
1081 name_len = strlen(name);
1084 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1085 if (cur->flg_read_only) {
1086 bb_error_msg("%s: readonly variable", name);
1087 return EXIT_FAILURE;
1089 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1090 * is ro, and we cannot reach this code on the 1st pass */
1091 prev->next = cur->next;
1092 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1093 bb_unsetenv(cur->varstr);
1097 return EXIT_SUCCESS;
1102 return EXIT_SUCCESS;
1105 #if ENABLE_SH_MATH_SUPPORT
1106 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1107 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1108 static char *endofname(const char *name)
1116 if (!is_in_name(*p))
1122 static void arith_set_local_var(const char *name, const char *val, int flags)
1124 /* arith code doesnt malloc space, so do it for it */
1125 char *var = xasprintf("%s=%s", name, val);
1126 set_local_var(var, flags, 0);
1134 static int static_get(struct in_str *i)
1143 static int static_peek(struct in_str *i)
1148 #if ENABLE_HUSH_INTERACTIVE
1150 static void cmdedit_set_initial_prompt(void)
1152 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1153 G.PS1 = getenv("PS1");
1160 static const char* setup_prompt_string(int promptmode)
1162 const char *prompt_str;
1163 debug_printf("setup_prompt_string %d ", promptmode);
1164 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1165 /* Set up the prompt */
1166 if (promptmode == 0) { /* PS1 */
1168 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1173 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1174 debug_printf("result '%s'\n", prompt_str);
1178 static void get_user_input(struct in_str *i)
1181 const char *prompt_str;
1183 prompt_str = setup_prompt_string(i->promptmode);
1184 #if ENABLE_FEATURE_EDITING
1185 /* Enable command line editing only while a command line
1186 * is actually being read */
1189 /* buglet: SIGINT will not make new prompt to appear _at once_,
1190 * only after <Enter>. (^C will work) */
1191 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1192 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1193 check_and_run_traps(0);
1194 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1195 i->eof_flag = (r < 0);
1196 if (i->eof_flag) { /* EOF/error detected */
1197 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1198 G.user_input_buf[1] = '\0';
1203 fputs(prompt_str, stdout);
1205 G.user_input_buf[0] = r = fgetc(i->file);
1206 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1207 //do we need check_and_run_traps(0)? (maybe only if stdin)
1208 } while (G.flag_SIGINT);
1209 i->eof_flag = (r == EOF);
1211 i->p = G.user_input_buf;
1214 #endif /* INTERACTIVE */
1216 /* This is the magic location that prints prompts
1217 * and gets data back from the user */
1218 static int file_get(struct in_str *i)
1222 /* If there is data waiting, eat it up */
1223 if (i->p && *i->p) {
1224 #if ENABLE_HUSH_INTERACTIVE
1228 if (i->eof_flag && !*i->p)
1231 /* need to double check i->file because we might be doing something
1232 * more complicated by now, like sourcing or substituting. */
1233 #if ENABLE_HUSH_INTERACTIVE
1234 if (G_interactive_fd && i->promptme && i->file == stdin) {
1237 } while (!*i->p); /* need non-empty line */
1238 i->promptmode = 1; /* PS2 */
1243 ch = fgetc(i->file);
1245 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1246 #if ENABLE_HUSH_INTERACTIVE
1253 /* All the callers guarantee this routine will never be
1254 * used right after a newline, so prompting is not needed.
1256 static int file_peek(struct in_str *i)
1259 if (i->p && *i->p) {
1260 if (i->eof_flag && !i->p[1])
1264 ch = fgetc(i->file);
1265 i->eof_flag = (ch == EOF);
1266 i->peek_buf[0] = ch;
1267 i->peek_buf[1] = '\0';
1269 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1273 static void setup_file_in_str(struct in_str *i, FILE *f)
1275 i->peek = file_peek;
1277 #if ENABLE_HUSH_INTERACTIVE
1279 i->promptmode = 0; /* PS1 */
1285 static void setup_string_in_str(struct in_str *i, const char *s)
1287 i->peek = static_peek;
1288 i->get = static_get;
1289 #if ENABLE_HUSH_INTERACTIVE
1291 i->promptmode = 0; /* PS1 */
1301 #define B_CHUNK (32 * sizeof(char*))
1303 static void o_reset(o_string *o)
1311 static void o_free(o_string *o)
1314 memset(o, 0, sizeof(*o));
1317 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1322 static void o_grow_by(o_string *o, int len)
1324 if (o->length + len > o->maxlen) {
1325 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1326 o->data = xrealloc(o->data, 1 + o->maxlen);
1330 static void o_addchr(o_string *o, int ch)
1332 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1334 o->data[o->length] = ch;
1336 o->data[o->length] = '\0';
1339 static void o_addblock(o_string *o, const char *str, int len)
1342 memcpy(&o->data[o->length], str, len);
1344 o->data[o->length] = '\0';
1348 static void o_addstr(o_string *o, const char *str)
1350 o_addblock(o, str, strlen(str));
1354 static void o_addstr_with_NUL(o_string *o, const char *str)
1356 o_addblock(o, str, strlen(str) + 1);
1359 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1364 && (*str != '*' && *str != '?' && *str != '[')
1372 /* My analysis of quoting semantics tells me that state information
1373 * is associated with a destination, not a source.
1375 static void o_addqchr(o_string *o, int ch)
1378 char *found = strchr("*?[\\", ch);
1383 o->data[o->length] = '\\';
1386 o->data[o->length] = ch;
1388 o->data[o->length] = '\0';
1391 static void o_addQchr(o_string *o, int ch)
1394 if (o->o_escape && strchr("*?[\\", ch)) {
1396 o->data[o->length] = '\\';
1400 o->data[o->length] = ch;
1402 o->data[o->length] = '\0';
1405 static void o_addQstr(o_string *o, const char *str, int len)
1408 o_addblock(o, str, len);
1414 int ordinary_cnt = strcspn(str, "*?[\\");
1415 if (ordinary_cnt > len) /* paranoia */
1417 o_addblock(o, str, ordinary_cnt);
1418 if (ordinary_cnt == len)
1420 str += ordinary_cnt;
1421 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1425 if (ch) { /* it is necessarily one of "*?[\\" */
1427 o->data[o->length] = '\\';
1431 o->data[o->length] = ch;
1433 o->data[o->length] = '\0';
1437 /* A special kind of o_string for $VAR and `cmd` expansion.
1438 * It contains char* list[] at the beginning, which is grown in 16 element
1439 * increments. Actual string data starts at the next multiple of 16 * (char*).
1440 * list[i] contains an INDEX (int!) into this string data.
1441 * It means that if list[] needs to grow, data needs to be moved higher up
1442 * but list[i]'s need not be modified.
1443 * NB: remembering how many list[i]'s you have there is crucial.
1444 * o_finalize_list() operation post-processes this structure - calculates
1445 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1447 #if DEBUG_EXPAND || DEBUG_GLOB
1448 static void debug_print_list(const char *prefix, o_string *o, int n)
1450 char **list = (char**)o->data;
1451 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1453 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1454 prefix, list, n, string_start, o->length, o->maxlen);
1456 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1457 o->data + (int)list[i] + string_start,
1458 o->data + (int)list[i] + string_start);
1462 const char *p = o->data + (int)list[n - 1] + string_start;
1463 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1467 #define debug_print_list(prefix, o, n) ((void)0)
1470 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1471 * in list[n] so that it points past last stored byte so far.
1472 * It returns n+1. */
1473 static int o_save_ptr_helper(o_string *o, int n)
1475 char **list = (char**)o->data;
1479 if (!o->has_empty_slot) {
1480 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1481 string_len = o->length - string_start;
1482 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1483 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1484 /* list[n] points to string_start, make space for 16 more pointers */
1485 o->maxlen += 0x10 * sizeof(list[0]);
1486 o->data = xrealloc(o->data, o->maxlen + 1);
1487 list = (char**)o->data;
1488 memmove(list + n + 0x10, list + n, string_len);
1489 o->length += 0x10 * sizeof(list[0]);
1491 debug_printf_list("list[%d]=%d string_start=%d\n",
1492 n, string_len, string_start);
1495 /* We have empty slot at list[n], reuse without growth */
1496 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1497 string_len = o->length - string_start;
1498 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1499 n, string_len, string_start);
1500 o->has_empty_slot = 0;
1502 list[n] = (char*)(ptrdiff_t)string_len;
1506 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1507 static int o_get_last_ptr(o_string *o, int n)
1509 char **list = (char**)o->data;
1510 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1512 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1515 /* o_glob performs globbing on last list[], saving each result
1516 * as a new list[]. */
1517 static int o_glob(o_string *o, int n)
1523 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1525 return o_save_ptr_helper(o, n);
1526 pattern = o->data + o_get_last_ptr(o, n);
1527 debug_printf_glob("glob pattern '%s'\n", pattern);
1528 if (!glob_needed(pattern)) {
1530 o->length = unbackslash(pattern) - o->data;
1531 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1532 return o_save_ptr_helper(o, n);
1535 memset(&globdata, 0, sizeof(globdata));
1536 gr = glob(pattern, 0, NULL, &globdata);
1537 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1538 if (gr == GLOB_NOSPACE)
1539 bb_error_msg_and_die("out of memory during glob");
1540 if (gr == GLOB_NOMATCH) {
1541 globfree(&globdata);
1544 if (gr != 0) { /* GLOB_ABORTED ? */
1545 //TODO: testcase for bad glob pattern behavior
1546 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1548 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1549 char **argv = globdata.gl_pathv;
1550 o->length = pattern - o->data; /* "forget" pattern */
1552 o_addstr_with_NUL(o, *argv);
1553 n = o_save_ptr_helper(o, n);
1559 globfree(&globdata);
1561 debug_print_list("o_glob returning", o, n);
1565 /* If o->o_glob == 1, glob the string so far remembered.
1566 * Otherwise, just finish current list[] and start new */
1567 static int o_save_ptr(o_string *o, int n)
1569 if (o->o_glob) { /* if globbing is requested */
1570 /* If o->has_empty_slot, list[n] was already globbed
1571 * (if it was requested back then when it was filled)
1572 * so don't do that again! */
1573 if (!o->has_empty_slot)
1574 return o_glob(o, n); /* o_save_ptr_helper is inside */
1576 return o_save_ptr_helper(o, n);
1579 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1580 static char **o_finalize_list(o_string *o, int n)
1585 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1587 debug_print_list("finalized", o, n);
1588 debug_printf_expand("finalized n:%d\n", n);
1589 list = (char**)o->data;
1590 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1594 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1600 /* Expansion can recurse */
1601 #if ENABLE_HUSH_TICK
1602 static int process_command_subs(o_string *dest, const char *s);
1604 static char *expand_string_to_string(const char *str);
1606 #define parse_stream_dquoted(ctx, dest, input, dquote_end) \
1607 parse_stream_dquoted(dest, input, dquote_end)
1609 static int parse_stream_dquoted(struct parse_context *ctx,
1611 struct in_str *input,
1614 /* expand_strvec_to_strvec() takes a list of strings, expands
1615 * all variable references within and returns a pointer to
1616 * a list of expanded strings, possibly with larger number
1617 * of strings. (Think VAR="a b"; echo $VAR).
1618 * This new list is allocated as a single malloc block.
1619 * NULL-terminated list of char* pointers is at the beginning of it,
1620 * followed by strings themself.
1621 * Caller can deallocate entire list by single free(list). */
1623 /* Store given string, finalizing the word and starting new one whenever
1624 * we encounter IFS char(s). This is used for expanding variable values.
1625 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1626 static int expand_on_ifs(o_string *output, int n, const char *str)
1629 int word_len = strcspn(str, G.ifs);
1631 if (output->o_escape || !output->o_glob)
1632 o_addQstr(output, str, word_len);
1633 else /* protect backslashes against globbing up :) */
1634 o_addblock_duplicate_backslash(output, str, word_len);
1637 if (!*str) /* EOL - do not finalize word */
1639 o_addchr(output, '\0');
1640 debug_print_list("expand_on_ifs", output, n);
1641 n = o_save_ptr(output, n);
1642 str += strspn(str, G.ifs); /* skip ifs chars */
1644 debug_print_list("expand_on_ifs[1]", output, n);
1648 /* Expand all variable references in given string, adding words to list[]
1649 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1650 * to be filled). This routine is extremely tricky: has to deal with
1651 * variables/parameters with whitespace, $* and $@, and constructs like
1652 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1653 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1655 /* or_mask is either 0 (normal case) or 0x80
1656 * (expansion of right-hand side of assignment == 1-element expand.
1657 * It will also do no globbing, and thus we must not backslash-quote!) */
1659 char first_ch, ored_ch;
1666 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1667 debug_print_list("expand_vars_to_list", output, n);
1668 n = o_save_ptr(output, n);
1669 debug_print_list("expand_vars_to_list[0]", output, n);
1671 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1672 #if ENABLE_HUSH_TICK
1673 o_string subst_result = NULL_O_STRING;
1675 #if ENABLE_SH_MATH_SUPPORT
1676 char arith_buf[sizeof(arith_t)*3 + 2];
1678 o_addblock(output, arg, p - arg);
1679 debug_print_list("expand_vars_to_list[1]", output, n);
1681 p = strchr(p, SPECIAL_VAR_SYMBOL);
1683 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1684 /* "$@" is special. Even if quoted, it can still
1685 * expand to nothing (not even an empty string) */
1686 if ((first_ch & 0x7f) != '@')
1687 ored_ch |= first_ch;
1690 switch (first_ch & 0x7f) {
1691 /* Highest bit in first_ch indicates that var is double-quoted */
1693 val = utoa(G.root_pid);
1695 case '!': /* bg pid */
1696 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1698 case '?': /* exitcode */
1699 val = utoa(G.last_return_code);
1701 case '#': /* argc */
1702 if (arg[1] != SPECIAL_VAR_SYMBOL)
1703 /* actually, it's a ${#var} */
1705 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1710 if (!G.global_argv[i])
1712 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1713 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1714 smallint sv = output->o_escape;
1715 /* unquoted var's contents should be globbed, so don't escape */
1716 output->o_escape = 0;
1717 while (G.global_argv[i]) {
1718 n = expand_on_ifs(output, n, G.global_argv[i]);
1719 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1720 if (G.global_argv[i++][0] && G.global_argv[i]) {
1721 /* this argv[] is not empty and not last:
1722 * put terminating NUL, start new word */
1723 o_addchr(output, '\0');
1724 debug_print_list("expand_vars_to_list[2]", output, n);
1725 n = o_save_ptr(output, n);
1726 debug_print_list("expand_vars_to_list[3]", output, n);
1729 output->o_escape = sv;
1731 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1732 * and in this case should treat it like '$*' - see 'else...' below */
1733 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1735 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1736 if (++i >= G.global_argc)
1738 o_addchr(output, '\0');
1739 debug_print_list("expand_vars_to_list[4]", output, n);
1740 n = o_save_ptr(output, n);
1742 } else { /* quoted $*: add as one word */
1744 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1745 if (!G.global_argv[++i])
1748 o_addchr(output, G.ifs[0]);
1752 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1753 /* "Empty variable", used to make "" etc to not disappear */
1757 #if ENABLE_HUSH_TICK
1758 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1761 //TODO: can we just stuff it into "output" directly?
1762 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1763 process_command_subs(&subst_result, arg);
1764 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1765 val = subst_result.data;
1768 #if ENABLE_SH_MATH_SUPPORT
1769 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1770 arith_eval_hooks_t hooks;
1775 arg++; /* skip '+' */
1776 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1777 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1779 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1782 unsigned char c = *exp_str++;
1789 if (strchr(" \t+-*/%_", c) != NULL)
1791 c |= 0x20; /* tolower */
1792 if (c >= 'a' && c <= 'z')
1796 /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
1798 struct in_str input;
1799 o_string dest = NULL_O_STRING;
1801 setup_string_in_str(&input, arg);
1802 parse_stream_dquoted(NULL, &dest, &input, EOF);
1803 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1804 exp_str = expand_string_to_string(dest.data);
1805 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1809 hooks.lookupvar = get_local_var_value;
1810 hooks.setvar = arith_set_local_var;
1811 hooks.endofname = endofname;
1812 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1817 case -3: maybe_die("arith", "exponent less than 0"); break;
1818 case -2: maybe_die("arith", "divide by zero"); break;
1819 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1820 default: maybe_die("arith", "syntax error"); break;
1823 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1824 sprintf(arith_buf, arith_t_fmt, res);
1829 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1831 bool exp_len = false;
1832 bool exp_null = false;
1834 char exp_save = exp_save; /* for compiler */
1835 char exp_op = exp_op; /* for compiler */
1836 char *exp_word = exp_word; /* for compiler */
1840 arg[0] = first_ch & 0x7f;
1842 /* prepare for expansions */
1843 if (var[0] == '#') {
1844 /* handle length expansion ${#var} */
1848 /* maybe handle parameter expansion */
1849 exp_off = strcspn(var, ":-=+?");
1853 exp_save = var[exp_off];
1854 exp_null = exp_save == ':';
1855 exp_word = var + exp_off;
1856 if (exp_null) ++exp_word;
1857 exp_op = *exp_word++;
1858 var[exp_off] = '\0';
1862 /* lookup the variable in question */
1863 if (isdigit(var[0])) {
1864 /* handle_dollar() should have vetted var for us */
1866 if (i < G.global_argc)
1867 val = G.global_argv[i];
1868 /* else val remains NULL: $N with too big N */
1870 val = get_local_var_value(var);
1872 /* handle any expansions */
1874 debug_printf_expand("expand: length of '%s' = ", val);
1875 val = utoa(val ? strlen(val) : 0);
1876 debug_printf_expand("%s\n", val);
1877 } else if (exp_off) {
1878 /* we need to do an expansion */
1879 int exp_test = (!val || (exp_null && !val[0]));
1881 exp_test = !exp_test;
1882 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1883 exp_null ? "true" : "false", exp_test);
1886 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1890 if (exp_op == '=') {
1891 if (isdigit(var[0]) || var[0] == '#') {
1892 maybe_die(var, "special vars cannot assign in this way");
1895 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1896 sprintf(new_var, "%s=%s", var, val);
1897 set_local_var(new_var, -1, 0);
1901 var[exp_off] = exp_save;
1905 #if ENABLE_HUSH_TICK
1908 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1909 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1911 /* unquoted var's contents should be globbed, so don't escape */
1912 smallint sv = output->o_escape;
1913 output->o_escape = 0;
1914 n = expand_on_ifs(output, n, val);
1916 output->o_escape = sv;
1918 } else { /* quoted $VAR, val will be appended below */
1919 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1922 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1924 o_addQstr(output, val, strlen(val));
1926 /* Do the check to avoid writing to a const string */
1927 if (*p != SPECIAL_VAR_SYMBOL)
1928 *p = SPECIAL_VAR_SYMBOL;
1930 #if ENABLE_HUSH_TICK
1931 o_free(&subst_result);
1934 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1937 debug_print_list("expand_vars_to_list[a]", output, n);
1938 /* this part is literal, and it was already pre-quoted
1939 * if needed (much earlier), do not use o_addQstr here! */
1940 o_addstr_with_NUL(output, arg);
1941 debug_print_list("expand_vars_to_list[b]", output, n);
1942 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1943 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1946 /* allow to reuse list[n] later without re-growth */
1947 output->has_empty_slot = 1;
1949 o_addchr(output, '\0');
1954 static char **expand_variables(char **argv, int or_mask)
1959 o_string output = NULL_O_STRING;
1961 if (or_mask & 0x100) {
1962 output.o_escape = 1; /* protect against globbing for "$var" */
1963 /* (unquoted $var will temporarily switch it off) */
1970 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1973 debug_print_list("expand_variables", &output, n);
1975 /* output.data (malloced in one block) gets returned in "list" */
1976 list = o_finalize_list(&output, n);
1977 debug_print_strings("expand_variables[1]", list);
1981 static char **expand_strvec_to_strvec(char **argv)
1983 return expand_variables(argv, 0x100);
1986 /* Used for expansion of right hand of assignments */
1987 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1989 static char *expand_string_to_string(const char *str)
1991 char *argv[2], **list;
1993 argv[0] = (char*)str;
1995 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1997 if (!list[0] || list[1])
1998 bb_error_msg_and_die("BUG in varexp2");
1999 /* actually, just move string 2*sizeof(char*) bytes back */
2000 overlapping_strcpy((char*)list, list[0]);
2001 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2005 /* Used for "eval" builtin */
2006 static char* expand_strvec_to_string(char **argv)
2010 list = expand_variables(argv, 0x80);
2011 /* Convert all NULs to spaces */
2016 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2017 bb_error_msg_and_die("BUG in varexp3");
2018 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2022 overlapping_strcpy((char*)list, list[0]);
2023 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2027 static char **expand_assignments(char **argv, int count)
2031 /* Expand assignments into one string each */
2032 for (i = 0; i < count; i++) {
2033 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2039 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2040 * and stderr if they are redirected. */
2041 static int setup_redirects(struct command *prog, int squirrel[])
2044 struct redir_struct *redir;
2046 for (redir = prog->redirects; redir; redir = redir->next) {
2047 if (redir->dup == -1 && redir->rd_filename == NULL) {
2048 /* something went wrong in the parse. Pretend it didn't happen */
2051 if (redir->dup == -1) {
2053 mode = redir_table[redir->rd_type].mode;
2054 //TODO: check redir for names like '\\'
2055 p = expand_string_to_string(redir->rd_filename);
2056 openfd = open_or_warn(p, mode);
2059 /* this could get lost if stderr has been redirected, but
2060 bash and ash both lose it as well (though zsh doesn't!) */
2064 openfd = redir->dup;
2067 if (openfd != redir->fd) {
2068 if (squirrel && redir->fd < 3) {
2069 squirrel[redir->fd] = dup(redir->fd);
2072 //close(openfd); // close(-3) ??!
2074 dup2(openfd, redir->fd);
2075 if (redir->dup == -1)
2083 static void restore_redirects(int squirrel[])
2086 for (i = 0; i < 3; i++) {
2089 /* We simply die on error */
2096 #if !defined(DEBUG_CLEAN)
2097 #define free_pipe_list(head, indent) free_pipe_list(head)
2098 #define free_pipe(pi, indent) free_pipe(pi)
2100 static void free_pipe_list(struct pipe *head, int indent);
2102 /* Return code is the exit status of the pipe */
2103 static void free_pipe(struct pipe *pi, int indent)
2106 struct command *command;
2107 struct redir_struct *r, *rnext;
2110 if (pi->stopped_cmds > 0) /* why? */
2112 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2113 for (i = 0; i < pi->num_cmds; i++) {
2114 command = &pi->cmds[i];
2115 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2116 if (command->argv) {
2117 for (a = 0, p = command->argv; *p; a++, p++) {
2118 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2120 free_strings(command->argv);
2121 command->argv = NULL;
2123 /* not "else if": on syntax error, we may have both! */
2124 if (command->group) {
2125 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2126 free_pipe_list(command->group, indent+3);
2127 debug_printf_clean("%s end group\n", indenter(indent));
2128 command->group = NULL;
2131 free(command->group_as_string);
2132 command->group_as_string = NULL;
2134 for (r = command->redirects; r; r = rnext) {
2135 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2137 /* guard against the case >$FOO, where foo is unset or blank */
2138 if (r->rd_filename) {
2139 debug_printf_clean(" %s\n", r->rd_filename);
2140 free(r->rd_filename);
2141 r->rd_filename = NULL;
2144 debug_printf_clean("&%d\n", r->dup);
2149 command->redirects = NULL;
2151 free(pi->cmds); /* children are an array, they get freed all at once */
2159 static void free_pipe_list(struct pipe *head, int indent)
2161 struct pipe *pi, *next;
2163 for (pi = head; pi; pi = next) {
2165 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2167 free_pipe(pi, indent);
2168 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2170 /*pi->next = NULL;*/
2177 typedef struct nommu_save_t {
2183 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2184 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2185 #define pseudo_exec(nommu_save, command, argv_expanded) \
2186 pseudo_exec(command, argv_expanded)
2189 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2191 * XXX no exit() here. If you don't exec, use _exit instead.
2192 * The at_exit handlers apparently confuse the calling process,
2193 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2194 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2195 char **argv, int assignment_cnt,
2196 char **argv_expanded) NORETURN;
2197 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2198 char **argv, int assignment_cnt,
2199 char **argv_expanded)
2203 /* Case when we are here: ... | var=val | ... */
2204 if (!argv[assignment_cnt])
2205 _exit(EXIT_SUCCESS);
2207 new_env = expand_assignments(argv, assignment_cnt);
2209 putenv_all(new_env);
2210 free(new_env); /* optional */
2212 nommu_save->new_env = new_env;
2213 nommu_save->old_env = putenv_all_and_save_old(new_env);
2215 if (argv_expanded) {
2216 argv = argv_expanded;
2218 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2220 nommu_save->argv = argv;
2224 /* On NOMMU, we must never block!
2225 * Example: { sleep 99999 | read line } & echo Ok
2226 * read builtin will block on read syscall, leaving parent blocked
2227 * in vfork. Therefore we can't do this:
2230 /* Check if the command matches any of the builtins.
2231 * Depending on context, this might be redundant. But it's
2232 * easier to waste a few CPU cycles than it is to figure out
2233 * if this is one of those cases.
2237 const struct built_in_command *x;
2238 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2239 if (strcmp(argv[0], x->cmd) == 0) {
2240 debug_printf_exec("running builtin '%s'\n",
2242 rcode = x->function(argv);
2250 #if ENABLE_FEATURE_SH_STANDALONE
2251 /* Check if the command matches any busybox applets */
2252 if (strchr(argv[0], '/') == NULL) {
2253 int a = find_applet_by_name(argv[0]);
2255 #if BB_MMU /* see above why on NOMMU it is not allowed */
2256 if (APPLET_IS_NOEXEC(a)) {
2257 debug_printf_exec("running applet '%s'\n", argv[0]);
2258 run_applet_no_and_exit(a, argv);
2261 /* Re-exec ourselves */
2262 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2263 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2264 execv(bb_busybox_exec_path, argv);
2265 /* If they called chroot or otherwise made the binary no longer
2266 * executable, fall through */
2271 debug_printf_exec("execing '%s'\n", argv[0]);
2272 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2273 execvp(argv[0], argv);
2274 bb_perror_msg("can't exec '%s'", argv[0]);
2275 _exit(EXIT_FAILURE);
2279 static void re_execute_shell(const char *s) NORETURN;
2280 static void re_execute_shell(const char *s)
2282 struct variable *cur;
2283 char **argv, **pp, **pp2;
2286 /* 1:hush 2:-$<pid> 3:-!<pid> 4:-?<exitcode> 5:-D<depth> <vars...>
2287 * 6:-c 7:<cmd> <argN...> 8:NULL
2289 cnt = 8 + G.global_argc;
2290 for (cur = G.top_var; cur; cur = cur->next) {
2291 if (!cur->flg_export || cur->flg_read_only)
2294 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2295 *pp++ = (char *) G.argv0_for_re_execing;
2296 *pp++ = xasprintf("-$%u", (unsigned) G.root_pid);
2297 *pp++ = xasprintf("-!%u", (unsigned) G.last_bg_pid);
2298 *pp++ = xasprintf("-?%u", (unsigned) G.last_return_code);
2299 #if ENABLE_HUSH_LOOPS
2300 *pp++ = xasprintf("-D%u", G.depth_of_loop);
2302 for (cur = G.top_var; cur; cur = cur->next) {
2303 if (cur->varstr == hush_version_str)
2305 if (cur->flg_read_only) {
2306 *pp++ = (char *) "-R";
2307 *pp++ = cur->varstr;
2308 } else if (!cur->flg_export) {
2309 *pp++ = (char *) "-V";
2310 *pp++ = cur->varstr;
2313 *pp++ = (char *) "-c";
2315 pp2 = G.global_argv;
2318 /* *pp = NULL; - is already there */
2319 //TODO: pass traps and functions
2321 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2322 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2323 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2324 /* Fallback. Useful for init=/bin/hush usage etc */
2325 if (G.argv0_for_re_execing[0] == '/')
2326 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2327 xfunc_error_retval = 127;
2328 bb_error_msg_and_die("can't re-execute the shell");
2331 static void clean_up_after_re_execute(void)
2333 char **pp = G.argv_from_re_execing;
2335 /* Must match re_execute_shell's allocations */
2339 #if ENABLE_HUSH_LOOPS
2343 G.argv_from_re_execing = NULL;
2347 #define clean_up_after_re_execute() ((void)0)
2350 static int run_list(struct pipe *pi);
2352 /* Called after [v]fork() in run_pipe()
2354 static void pseudo_exec(nommu_save_t *nommu_save,
2355 struct command *command,
2356 char **argv_expanded) NORETURN;
2357 static void pseudo_exec(nommu_save_t *nommu_save,
2358 struct command *command,
2359 char **argv_expanded)
2361 if (command->argv) {
2362 pseudo_exec_argv(nommu_save, command->argv,
2363 command->assignment_cnt, argv_expanded);
2366 if (command->group) {
2367 /* Cases when we are here:
2370 * ... | ( list ) | ...
2371 * ... | { list } | ...
2375 debug_printf_exec("pseudo_exec: run_list\n");
2376 rcode = run_list(command->group);
2377 /* OK to leak memory by not calling free_pipe_list,
2378 * since this process is about to exit */
2381 re_execute_shell(command->group_as_string);
2385 /* Case when we are here: ... | >file */
2386 debug_printf_exec("pseudo_exec'ed null command\n");
2387 _exit(EXIT_SUCCESS);
2391 static const char *get_cmdtext(struct pipe *pi)
2397 /* This is subtle. ->cmdtext is created only on first backgrounding.
2398 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2399 * On subsequent bg argv is trashed, but we won't use it */
2402 argv = pi->cmds[0].argv;
2403 if (!argv || !argv[0]) {
2404 pi->cmdtext = xzalloc(1);
2409 do len += strlen(*argv) + 1; while (*++argv);
2410 pi->cmdtext = p = xmalloc(len);
2411 argv = pi->cmds[0].argv;
2413 len = strlen(*argv);
2414 memcpy(p, *argv, len);
2422 static void insert_bg_job(struct pipe *pi)
2424 struct pipe *thejob;
2427 /* Linear search for the ID of the job to use */
2429 for (thejob = G.job_list; thejob; thejob = thejob->next)
2430 if (thejob->jobid >= pi->jobid)
2431 pi->jobid = thejob->jobid + 1;
2433 /* Add thejob to the list of running jobs */
2435 thejob = G.job_list = xmalloc(sizeof(*thejob));
2437 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2439 thejob->next = xmalloc(sizeof(*thejob));
2440 thejob = thejob->next;
2443 /* Physically copy the struct job */
2444 memcpy(thejob, pi, sizeof(struct pipe));
2445 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2446 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2447 for (i = 0; i < pi->num_cmds; i++) {
2448 // TODO: do we really need to have so many fields which are just dead weight
2449 // at execution stage?
2450 thejob->cmds[i].pid = pi->cmds[i].pid;
2451 /* all other fields are not used and stay zero */
2453 thejob->next = NULL;
2454 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2456 /* We don't wait for background thejobs to return -- append it
2457 to the list of backgrounded thejobs and leave it alone */
2458 if (G_interactive_fd)
2459 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2460 G.last_bg_pid = thejob->cmds[0].pid;
2461 G.last_jobid = thejob->jobid;
2464 static void remove_bg_job(struct pipe *pi)
2466 struct pipe *prev_pipe;
2468 if (pi == G.job_list) {
2469 G.job_list = pi->next;
2471 prev_pipe = G.job_list;
2472 while (prev_pipe->next != pi)
2473 prev_pipe = prev_pipe->next;
2474 prev_pipe->next = pi->next;
2477 G.last_jobid = G.job_list->jobid;
2482 /* Remove a backgrounded job */
2483 static void delete_finished_bg_job(struct pipe *pi)
2486 pi->stopped_cmds = 0;
2492 /* Check to see if any processes have exited -- if they
2493 * have, figure out why and see if a job has completed */
2494 static int checkjobs(struct pipe* fg_pipe)
2504 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2507 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2508 // /* avoid doing syscall, nothing there anyway */
2511 attributes = WUNTRACED;
2512 if (fg_pipe == NULL)
2513 attributes |= WNOHANG;
2515 /* Do we do this right?
2516 * bash-3.00# sleep 20 | false
2518 * [3]+ Stopped sleep 20 | false
2519 * bash-3.00# echo $?
2520 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2523 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2524 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2525 // + killall -STOP cat
2532 // i = G.count_SIGCHLD;
2533 childpid = waitpid(-1, &status, attributes);
2534 if (childpid <= 0) {
2535 if (childpid && errno != ECHILD)
2536 bb_perror_msg("waitpid");
2537 // else /* Until next SIGCHLD, waitpid's are useless */
2538 // G.handled_SIGCHLD = i;
2541 dead = WIFEXITED(status) || WIFSIGNALED(status);
2544 if (WIFSTOPPED(status))
2545 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2546 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2547 if (WIFSIGNALED(status))
2548 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2549 childpid, WTERMSIG(status), WEXITSTATUS(status));
2550 if (WIFEXITED(status))
2551 debug_printf_jobs("pid %d exited, exitcode %d\n",
2552 childpid, WEXITSTATUS(status));
2554 /* Were we asked to wait for fg pipe? */
2556 for (i = 0; i < fg_pipe->num_cmds; i++) {
2557 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2558 if (fg_pipe->cmds[i].pid != childpid)
2560 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2562 fg_pipe->cmds[i].pid = 0;
2563 fg_pipe->alive_cmds--;
2564 if (i == fg_pipe->num_cmds - 1) {
2565 /* last process gives overall exitstatus */
2566 rcode = WEXITSTATUS(status);
2567 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2570 fg_pipe->cmds[i].is_stopped = 1;
2571 fg_pipe->stopped_cmds++;
2573 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2574 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2575 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2576 /* All processes in fg pipe have exited/stopped */
2578 if (fg_pipe->alive_cmds)
2579 insert_bg_job(fg_pipe);
2583 /* There are still running processes in the fg pipe */
2584 goto wait_more; /* do waitpid again */
2586 /* it wasnt fg_pipe, look for process in bg pipes */
2590 /* We asked to wait for bg or orphaned children */
2591 /* No need to remember exitcode in this case */
2592 for (pi = G.job_list; pi; pi = pi->next) {
2593 for (i = 0; i < pi->num_cmds; i++) {
2594 if (pi->cmds[i].pid == childpid)
2595 goto found_pi_and_prognum;
2598 /* Happens when shell is used as init process (init=/bin/sh) */
2599 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2600 continue; /* do waitpid again */
2602 found_pi_and_prognum:
2605 pi->cmds[i].pid = 0;
2607 if (!pi->alive_cmds) {
2608 if (G_interactive_fd)
2609 printf(JOB_STATUS_FORMAT, pi->jobid,
2610 "Done", pi->cmdtext);
2611 delete_finished_bg_job(pi);
2615 pi->cmds[i].is_stopped = 1;
2619 } /* while (waitpid succeeds)... */
2625 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2628 int rcode = checkjobs(fg_pipe);
2629 /* Job finished, move the shell to the foreground */
2630 p = getpgid(0); /* pgid of our process */
2631 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2632 tcsetpgrp(G_interactive_fd, p);
2637 /* Start all the jobs, but don't wait for anything to finish.
2640 * Return code is normally -1, when the caller has to wait for children
2641 * to finish to determine the exit status of the pipe. If the pipe
2642 * is a simple builtin command, however, the action is done by the
2643 * time run_pipe returns, and the exit code is provided as the
2646 * Returns -1 only if started some children. IOW: we have to
2647 * mask out retvals of builtins etc with 0xff!
2649 * The only case when we do not need to [v]fork is when the pipe
2650 * is single, non-backgrounded, non-subshell command. Examples:
2651 * cmd ; ... { list } ; ...
2652 * cmd && ... { list } && ...
2653 * cmd || ... { list } || ...
2654 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2655 * or (if SH_STANDALONE) an applet, and we can run the { list }
2656 * with run_list(). If it isn't one of these, we fork and exec cmd.
2658 * Cases when we must fork:
2659 * non-single: cmd | cmd
2660 * backgrounded: cmd & { list } &
2661 * subshell: ( list ) [&]
2663 static int run_pipe(struct pipe *pi)
2665 static const char *const null_ptr = NULL;
2668 int pipefds[2]; /* pipefds[0] is for reading */
2669 struct command *command;
2670 char **argv_expanded;
2673 /* it is not always needed, but we aim to smaller code */
2674 int squirrel[] = { -1, -1, -1 };
2677 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2679 USE_HUSH_JOB(pi->pgrp = -1;)
2680 pi->stopped_cmds = 0;
2681 command = &(pi->cmds[0]);
2682 argv_expanded = NULL;
2684 if (pi->num_cmds != 1
2685 || pi->followup == PIPE_BG
2686 || command->grp_type == GRP_SUBSHELL
2693 debug_printf_exec(": group:%p argv:'%s'\n",
2694 command->group, command->argv ? command->argv[0] : "NONE");
2696 if (command->group) {
2697 #if ENABLE_HUSH_FUNCTIONS
2698 if (command->grp_type == GRP_FUNCTION) {
2699 /* func () { list } */
2700 bb_error_msg("here we ought to remember function definition, and go on");
2701 return EXIT_SUCCESS;
2705 debug_printf("non-subshell group\n");
2706 setup_redirects(command, squirrel);
2707 debug_printf_exec(": run_list\n");
2708 rcode = run_list(command->group) & 0xff;
2709 restore_redirects(squirrel);
2710 debug_printf_exec("run_pipe return %d\n", rcode);
2711 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2715 argv = command->argv ? command->argv : (char **) &null_ptr;
2717 const struct built_in_command *x;
2718 char **new_env = NULL;
2719 char **old_env = NULL;
2721 if (argv[command->assignment_cnt] == NULL) {
2722 /* Assignments, but no command */
2723 /* Ensure redirects take effect. Try "a=t >file" */
2724 setup_redirects(command, squirrel);
2725 restore_redirects(squirrel);
2726 /* Set shell variables */
2728 p = expand_string_to_string(*argv);
2729 debug_printf_exec("set shell var:'%s'->'%s'\n",
2731 set_local_var(p, 0, 0);
2734 /* Do we need to flag set_local_var() errors?
2735 * "assignment to readonly var" and "putenv error"
2737 return EXIT_SUCCESS;
2740 /* Expand the rest into (possibly) many strings each */
2741 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2743 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2744 if (strcmp(argv_expanded[0], x->cmd) != 0)
2746 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2747 debug_printf("exec with redirects only\n");
2748 setup_redirects(command, NULL);
2749 rcode = EXIT_SUCCESS;
2750 goto clean_up_and_ret1;
2752 debug_printf("builtin inline %s\n", argv_expanded[0]);
2753 /* XXX setup_redirects acts on file descriptors, not FILEs.
2754 * This is perfect for work that comes after exec().
2755 * Is it really safe for inline use? Experimentally,
2756 * things seem to work with glibc. */
2757 setup_redirects(command, squirrel);
2758 new_env = expand_assignments(argv, command->assignment_cnt);
2759 old_env = putenv_all_and_save_old(new_env);
2760 debug_printf_exec(": builtin '%s' '%s'...\n",
2761 x->cmd, argv_expanded[1]);
2762 rcode = x->function(argv_expanded) & 0xff;
2763 #if ENABLE_FEATURE_SH_STANDALONE
2766 restore_redirects(squirrel);
2767 free_strings_and_unsetenv(new_env, 1);
2768 putenv_all(old_env);
2769 free(old_env); /* not free_strings()! */
2771 free(argv_expanded);
2772 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2773 debug_printf_exec("run_pipe return %d\n", rcode);
2776 #if ENABLE_FEATURE_SH_STANDALONE
2777 i = find_applet_by_name(argv_expanded[0]);
2778 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2779 setup_redirects(command, squirrel);
2780 save_nofork_data(&G.nofork_save);
2781 new_env = expand_assignments(argv, command->assignment_cnt);
2782 old_env = putenv_all_and_save_old(new_env);
2783 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2784 argv_expanded[0], argv_expanded[1]);
2785 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2786 goto clean_up_and_ret;
2789 /* It is neither builtin nor applet. We must fork. */
2793 /* NB: argv_expanded may already be created, and that
2794 * might include `cmd` runs! Do not rerun it! We *must*
2795 * use argv_expanded if it's non-NULL */
2797 /* Going to fork a child per each pipe member */
2801 for (i = 0; i < pi->num_cmds; i++) {
2803 volatile nommu_save_t nommu_save;
2804 nommu_save.new_env = NULL;
2805 nommu_save.old_env = NULL;
2806 nommu_save.argv = NULL;
2808 command = &(pi->cmds[i]);
2809 if (command->argv) {
2810 debug_printf_exec(": pipe member '%s' '%s'...\n",
2811 command->argv[0], command->argv[1]);
2813 debug_printf_exec(": pipe member with no argv\n");
2816 /* pipes are inserted between pairs of commands */
2819 if ((i + 1) < pi->num_cmds)
2822 command->pid = BB_MMU ? fork() : vfork();
2823 if (!command->pid) { /* child */
2825 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
2827 /* Every child adds itself to new process group
2828 * with pgid == pid_of_first_child_in_pipe */
2829 if (G.run_list_level == 1 && G_interactive_fd) {
2832 if (pgrp < 0) /* true for 1st process only */
2834 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2835 /* We do it in *every* child, not just first,
2837 tcsetpgrp(G_interactive_fd, pgrp);
2841 xmove_fd(nextin, 0);
2842 xmove_fd(pipefds[1], 1); /* write end */
2844 close(pipefds[0]); /* read end */
2845 /* Like bash, explicit redirects override pipes,
2846 * and the pipe fd is available for dup'ing. */
2847 setup_redirects(command, NULL);
2849 /* Restore default handlers just prior to exec */
2850 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2852 /* Stores to nommu_save list of env vars putenv'ed
2853 * (NOMMU, on MMU we don't need that) */
2854 /* cast away volatility... */
2855 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2856 /* pseudo_exec() does not return */
2859 /* parent or error */
2861 die_sleep = -1; /* restore tty pgrp on xfunc death */
2864 /* Clean up after vforked child */
2865 clean_up_after_re_execute();
2866 free(nommu_save.argv);
2867 free_strings_and_unsetenv(nommu_save.new_env, 1);
2868 putenv_all(nommu_save.old_env);
2870 free(argv_expanded);
2871 argv_expanded = NULL;
2872 if (command->pid < 0) { /* [v]fork failed */
2873 /* Clearly indicate, was it fork or vfork */
2874 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2878 /* Second and next children need to know pid of first one */
2880 pi->pgrp = command->pid;
2886 if ((i + 1) < pi->num_cmds)
2887 close(pipefds[1]); /* write end */
2888 /* Pass read (output) pipe end to next iteration */
2889 nextin = pipefds[0];
2892 if (!pi->alive_cmds) {
2893 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2897 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2901 #ifndef debug_print_tree
2902 static void debug_print_tree(struct pipe *pi, int lvl)
2904 static const char *const PIPE[] = {
2910 static const char *RES[] = {
2911 [RES_NONE ] = "NONE" ,
2914 [RES_THEN ] = "THEN" ,
2915 [RES_ELIF ] = "ELIF" ,
2916 [RES_ELSE ] = "ELSE" ,
2919 #if ENABLE_HUSH_LOOPS
2920 [RES_FOR ] = "FOR" ,
2921 [RES_WHILE] = "WHILE",
2922 [RES_UNTIL] = "UNTIL",
2924 [RES_DONE ] = "DONE" ,
2926 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2929 #if ENABLE_HUSH_CASE
2930 [RES_CASE ] = "CASE" ,
2931 [RES_MATCH] = "MATCH",
2932 [RES_CASEI] = "CASEI",
2933 [RES_ESAC ] = "ESAC" ,
2935 [RES_XXXX ] = "XXXX" ,
2936 [RES_SNTX ] = "SNTX" ,
2938 static const char *const GRPTYPE[] = {
2941 #if ENABLE_HUSH_FUNCTIONS
2950 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2951 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2953 while (prn < pi->num_cmds) {
2954 struct command *command = &pi->cmds[prn];
2955 char **argv = command->argv;
2957 fprintf(stderr, "%*s prog %d assignment_cnt:%d",
2959 command->assignment_cnt);
2960 if (command->group) {
2961 fprintf(stderr, " group %s: (argv=%p)\n",
2962 GRPTYPE[command->grp_type],
2964 debug_print_tree(command->group, lvl+1);
2968 if (argv) while (*argv) {
2969 fprintf(stderr, " '%s'", *argv);
2972 fprintf(stderr, "\n");
2981 /* NB: called by pseudo_exec, and therefore must not modify any
2982 * global data until exec/_exit (we can be a child after vfork!) */
2983 static int run_list(struct pipe *pi)
2985 #if ENABLE_HUSH_CASE
2986 char *case_word = NULL;
2988 #if ENABLE_HUSH_LOOPS
2989 struct pipe *loop_top = NULL;
2990 char *for_varname = NULL;
2991 char **for_lcur = NULL;
2992 char **for_list = NULL;
2994 smallint flag_skip = 1;
2995 smalluint rcode = 0; /* probably just for compiler */
2996 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2997 smalluint cond_code = 0;
2999 enum { cond_code = 0, };
3001 /*enum reserved_style*/ smallint rword = RES_NONE;
3002 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
3004 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3006 #if ENABLE_HUSH_LOOPS
3007 /* Check syntax for "for" */
3008 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3009 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3011 /* current word is FOR or IN (BOLD in comments below) */
3012 if (cpipe->next == NULL) {
3013 syntax("malformed for");
3014 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3017 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3018 if (cpipe->next->res_word == RES_DO)
3020 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3021 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3022 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3024 syntax("malformed for");
3025 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3031 /* Past this point, all code paths should jump to ret: label
3032 * in order to return, no direct "return" statements please.
3033 * This helps to ensure that no memory is leaked. */
3035 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3038 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3039 * We are saving state before entering outermost list ("while...done")
3040 * so that ctrl-Z will correctly background _entire_ outermost list,
3041 * not just a part of it (like "sleep 1 | exit 2") */
3042 if (++G.run_list_level == 1 && G_interactive_fd) {
3043 if (sigsetjmp(G.toplevel_jb, 1)) {
3044 /* ctrl-Z forked and we are parent; or ctrl-C.
3045 * Sighandler has longjmped us here */
3046 signal(SIGINT, SIG_IGN);
3047 signal(SIGTSTP, SIG_IGN);
3048 /* Restore level (we can be coming from deep inside
3050 G.run_list_level = 1;
3051 #if ENABLE_FEATURE_SH_STANDALONE
3052 if (G.nofork_save.saved) { /* if save area is valid */
3053 debug_printf_jobs("exiting nofork early\n");
3054 restore_nofork_data(&G.nofork_save);
3057 //// if (G.ctrl_z_flag) {
3058 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3059 //// * Remember this child as background job */
3060 //// insert_bg_job(pi);
3062 /* ctrl-C. We just stop doing whatever we were doing */
3065 USE_HUSH_LOOPS(loop_top = NULL;)
3066 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3070 //// /* ctrl-Z handler will store pid etc in pi */
3071 //// G.toplevel_list = pi;
3072 //// G.ctrl_z_flag = 0;
3073 ////#if ENABLE_FEATURE_SH_STANDALONE
3074 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3076 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3077 //// signal(SIGINT, handler_ctrl_c);
3081 /* Go through list of pipes, (maybe) executing them. */
3082 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3086 IF_HAS_KEYWORDS(rword = pi->res_word;)
3087 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
3088 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
3089 rword, cond_code, skip_more_for_this_rword);
3090 #if ENABLE_HUSH_LOOPS
3091 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3092 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3094 /* start of a loop: remember where loop starts */
3099 if (rword == skip_more_for_this_rword && flag_skip) {
3100 if (pi->followup == PIPE_SEQ)
3102 /* it is "<false> && CMD" or "<true> || CMD"
3103 * and we should not execute CMD */
3107 skip_more_for_this_rword = RES_XXXX;
3110 if (rword == RES_THEN) {
3111 /* "if <false> THEN cmd": skip cmd */
3115 if (rword == RES_ELSE || rword == RES_ELIF) {
3116 /* "if <true> then ... ELSE/ELIF cmd":
3117 * skip cmd and all following ones */
3122 #if ENABLE_HUSH_LOOPS
3123 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3125 /* first loop through for */
3127 static const char encoded_dollar_at[] ALIGN1 = {
3128 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3129 }; /* encoded representation of "$@" */
3130 static const char *const encoded_dollar_at_argv[] = {
3131 encoded_dollar_at, NULL
3132 }; /* argv list with one element: "$@" */
3135 vals = (char**)encoded_dollar_at_argv;
3136 if (pi->next->res_word == RES_IN) {
3137 /* if no variable values after "in" we skip "for" */
3138 if (!pi->next->cmds[0].argv)
3140 vals = pi->next->cmds[0].argv;
3141 } /* else: "for var; do..." -> assume "$@" list */
3142 /* create list of variable values */
3143 debug_print_strings("for_list made from", vals);
3144 for_list = expand_strvec_to_strvec(vals);
3145 for_lcur = for_list;
3146 debug_print_strings("for_list", for_list);
3147 for_varname = pi->cmds[0].argv[0];
3148 pi->cmds[0].argv[0] = NULL;
3150 free(pi->cmds[0].argv[0]);
3152 /* "for" loop is over, clean up */
3156 pi->cmds[0].argv[0] = for_varname;
3159 /* insert next value from for_lcur */
3160 //TODO: does it need escaping?
3161 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3162 pi->cmds[0].assignment_cnt = 1;
3164 if (rword == RES_IN) {
3165 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3167 if (rword == RES_DONE) {
3168 continue; /* "done" has no cmds too */
3171 #if ENABLE_HUSH_CASE
3172 if (rword == RES_CASE) {
3173 case_word = expand_strvec_to_string(pi->cmds->argv);
3176 if (rword == RES_MATCH) {
3179 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3181 /* all prev words didn't match, does this one match? */
3182 argv = pi->cmds->argv;
3184 char *pattern = expand_string_to_string(*argv);
3185 /* TODO: which FNM_xxx flags to use? */
3186 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3188 if (cond_code == 0) { /* match! we will execute this branch */
3189 free(case_word); /* make future "word)" stop */
3197 if (rword == RES_CASEI) { /* inside of a case branch */
3199 continue; /* not matched yet, skip this pipe */
3202 /* Just pressing <enter> in shell should check for jobs.
3203 * OTOH, in non-interactive shell this is useless
3204 * and only leads to extra job checks */
3205 if (pi->num_cmds == 0) {
3206 if (G_interactive_fd)
3207 goto check_jobs_and_continue;
3211 /* After analyzing all keywords and conditions, we decided
3212 * to execute this pipe. NB: have to do checkjobs(NULL)
3213 * after run_pipe() to collect any background children,
3214 * even if list execution is to be stopped. */
3215 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3218 #if ENABLE_HUSH_LOOPS
3219 G.flag_break_continue = 0;
3221 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3223 /* we only ran a builtin: rcode is already known
3224 * and we don't need to wait for anything. */
3225 check_and_run_traps(0);
3226 #if ENABLE_HUSH_LOOPS
3227 /* was it "break" or "continue"? */
3228 if (G.flag_break_continue) {
3229 smallint fbc = G.flag_break_continue;
3230 /* we might fall into outer *loop*,
3231 * don't want to break it too */
3233 G.depth_break_continue--;
3234 if (G.depth_break_continue == 0)
3235 G.flag_break_continue = 0;
3236 /* else: e.g. "continue 2" should *break* once, *then* continue */
3237 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3238 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3239 goto check_jobs_and_break;
3240 /* "continue": simulate end of loop */
3245 } else if (pi->followup == PIPE_BG) {
3246 /* what does bash do with attempts to background builtins? */
3247 /* even bash 3.2 doesn't do that well with nested bg:
3248 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3249 * I'm NOT treating inner &'s as jobs */
3250 check_and_run_traps(0);
3252 if (G.run_list_level == 1)
3255 rcode = 0; /* EXIT_SUCCESS */
3258 if (G.run_list_level == 1 && G_interactive_fd) {
3259 /* waits for completion, then fg's main shell */
3260 rcode = checkjobs_and_fg_shell(pi);
3261 check_and_run_traps(0);
3262 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3265 { /* this one just waits for completion */
3266 rcode = checkjobs(pi);
3267 check_and_run_traps(0);
3268 debug_printf_exec(": checkjobs returned %d\n", rcode);
3272 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3273 G.last_return_code = rcode;
3275 /* Analyze how result affects subsequent commands */
3277 if (rword == RES_IF || rword == RES_ELIF)
3280 #if ENABLE_HUSH_LOOPS
3281 if (rword == RES_WHILE) {
3283 rcode = 0; /* "while false; do...done" - exitcode 0 */
3284 goto check_jobs_and_break;
3287 if (rword == RES_UNTIL) {
3289 check_jobs_and_break:
3295 if ((rcode == 0 && pi->followup == PIPE_OR)
3296 || (rcode != 0 && pi->followup == PIPE_AND)
3298 skip_more_for_this_rword = rword;
3301 check_jobs_and_continue:
3306 //// if (G.ctrl_z_flag) {
3307 //// /* ctrl-Z forked somewhere in the past, we are the child,
3308 //// * and now we completed running the list. Exit. */
3314 //// if (!G.run_list_level && G_interactive_fd) {
3315 //// signal(SIGTSTP, SIG_IGN);
3316 //// signal(SIGINT, SIG_IGN);
3319 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3320 #if ENABLE_HUSH_LOOPS
3325 #if ENABLE_HUSH_CASE
3331 /* Select which version we will use */
3332 static int run_and_free_list(struct pipe *pi)
3335 debug_printf_exec("run_and_free_list entered\n");
3337 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3338 rcode = run_list(pi);
3340 /* free_pipe_list has the side effect of clearing memory.
3341 * In the long run that function can be merged with run_list,
3342 * but doing that now would hobble the debugging effort. */
3343 free_pipe_list(pi, /* indent: */ 0);
3344 debug_printf_exec("run_and_free_list return %d\n", rcode);
3349 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3350 * as in "2>&1", that represents duplicating a file descriptor.
3351 * Return either -2 (syntax error), -1 (no &), or the number found.
3353 static int redirect_dup_num(struct in_str *input)
3355 int ch, d = 0, ok = 0;
3357 if (ch != '&') return -1;
3359 i_getch(input); /* get the & */
3363 return -3; /* "-" represents "close me" */
3365 while (isdigit(ch)) {
3366 d = d*10 + (ch-'0');
3373 bb_error_msg("ambiguous redirect");
3377 /* The src parameter allows us to peek forward to a possible &n syntax
3378 * for file descriptor duplication, e.g., "2>&1".
3379 * Return code is 0 normally, 1 if a syntax error is detected in src.
3380 * Resource errors (in xmalloc) cause the process to exit */
3381 static int setup_redirect(struct parse_context *ctx,
3384 struct in_str *input)
3386 struct command *command = ctx->command;
3387 struct redir_struct *redir;
3388 struct redir_struct **redirp;
3391 /* Check for a '2>&1' type redirect */
3392 dup_num = redirect_dup_num(input);
3394 return 1; /* syntax error */
3396 /* Create a new redir_struct and drop it onto the end of the linked list */
3397 redirp = &command->redirects;
3398 while ((redir = *redirp) != NULL) {
3399 redirp = &(redir->next);
3401 *redirp = redir = xzalloc(sizeof(*redir));
3402 /* redir->next = NULL; */
3403 /* redir->rd_filename = NULL; */
3404 redir->rd_type = style;
3405 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3407 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3409 redir->dup = dup_num;
3410 if (dup_num != -1) {
3411 /* Erik had a check here that the file descriptor in question
3412 * is legit; I postpone that to "run time"
3413 * A "-" representation of "close me" shows up as a -3 here */
3414 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3416 /* We do _not_ try to open the file that src points to,
3417 * since we need to return and let src be expanded first.
3418 * Set ctx->pending_redirect, so we know what to do at the
3419 * end of the next parsed word. */
3420 ctx->pending_redirect = redir;
3426 static struct pipe *new_pipe(void)
3429 pi = xzalloc(sizeof(struct pipe));
3430 /*pi->followup = 0; - deliberately invalid value */
3431 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3435 /* Command (member of a pipe) is complete. The only possible error here
3436 * is out of memory, in which case xmalloc exits. */
3437 static int done_command(struct parse_context *ctx)
3439 /* The command is really already in the pipe structure, so
3440 * advance the pipe counter and make a new, null command. */
3441 struct pipe *pi = ctx->pipe;
3442 struct command *command = ctx->command;
3445 if (command->group == NULL
3446 && command->argv == NULL
3447 && command->redirects == NULL
3449 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3450 return pi->num_cmds;
3453 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3455 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3458 /* Only real trickiness here is that the uncommitted
3459 * command structure is not counted in pi->num_cmds. */
3460 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3461 command = &pi->cmds[pi->num_cmds];
3462 memset(command, 0, sizeof(*command));
3464 ctx->command = command;
3465 /* but ctx->pipe and ctx->list_head remain unchanged */
3467 return pi->num_cmds; /* used only for 0/nonzero check */
3470 static void done_pipe(struct parse_context *ctx, pipe_style type)
3474 debug_printf_parse("done_pipe entered, followup %d\n", type);
3475 /* Close previous command */
3476 not_null = done_command(ctx);
3477 ctx->pipe->followup = type;
3478 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3479 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3480 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3482 /* Without this check, even just <enter> on command line generates
3483 * tree of three NOPs (!). Which is harmless but annoying.
3484 * IOW: it is safe to do it unconditionally.
3485 * RES_NONE case is for "for a in; do ..." (empty IN set)
3486 * to work, possibly other cases too. */
3487 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3489 debug_printf_parse("done_pipe: adding new pipe: "
3490 "not_null:%d ctx->ctx_res_w:%d\n",
3491 not_null, ctx->ctx_res_w);
3493 ctx->pipe->next = new_p;
3495 /* RES_THEN, RES_DO etc are "sticky" -
3496 * they remain set for commands inside if/while.
3497 * This is used to control execution.
3498 * RES_FOR and RES_IN are NOT sticky (needed to support
3499 * cases where variable or value happens to match a keyword):
3501 #if ENABLE_HUSH_LOOPS
3502 if (ctx->ctx_res_w == RES_FOR
3503 || ctx->ctx_res_w == RES_IN)
3504 ctx->ctx_res_w = RES_NONE;
3506 #if ENABLE_HUSH_CASE
3507 if (ctx->ctx_res_w == RES_MATCH)
3508 ctx->ctx_res_w = RES_CASEI;
3510 ctx->command = NULL; /* trick done_command below */
3511 /* Create the memory for command, roughly:
3512 * ctx->pipe->cmds = new struct command;
3513 * ctx->command = &ctx->pipe->cmds[0];
3517 debug_printf_parse("done_pipe return\n");
3520 static void initialize_context(struct parse_context *ctx)
3522 memset(ctx, 0, sizeof(*ctx));
3523 ctx->pipe = ctx->list_head = new_pipe();
3524 /* Create the memory for command, roughly:
3525 * ctx->pipe->cmds = new struct command;
3526 * ctx->command = &ctx->pipe->cmds[0];
3532 /* If a reserved word is found and processed, parse context is modified
3533 * and 1 is returned.
3536 struct reserved_combo {
3539 unsigned char assignment_flag;
3543 FLAG_END = (1 << RES_NONE ),
3545 FLAG_IF = (1 << RES_IF ),
3546 FLAG_THEN = (1 << RES_THEN ),
3547 FLAG_ELIF = (1 << RES_ELIF ),
3548 FLAG_ELSE = (1 << RES_ELSE ),
3549 FLAG_FI = (1 << RES_FI ),
3551 #if ENABLE_HUSH_LOOPS
3552 FLAG_FOR = (1 << RES_FOR ),
3553 FLAG_WHILE = (1 << RES_WHILE),
3554 FLAG_UNTIL = (1 << RES_UNTIL),
3555 FLAG_DO = (1 << RES_DO ),
3556 FLAG_DONE = (1 << RES_DONE ),
3557 FLAG_IN = (1 << RES_IN ),
3559 #if ENABLE_HUSH_CASE
3560 FLAG_MATCH = (1 << RES_MATCH),
3561 FLAG_ESAC = (1 << RES_ESAC ),
3563 FLAG_START = (1 << RES_XXXX ),
3566 static const struct reserved_combo* match_reserved_word(o_string *word)
3568 /* Mostly a list of accepted follow-up reserved words.
3569 * FLAG_END means we are done with the sequence, and are ready
3570 * to turn the compound list into a command.
3571 * FLAG_START means the word must start a new compound list.
3573 static const struct reserved_combo reserved_list[] = {
3575 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3576 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3577 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3578 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3579 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3580 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3582 #if ENABLE_HUSH_LOOPS
3583 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3584 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3585 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3586 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3587 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3588 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3590 #if ENABLE_HUSH_CASE
3591 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3592 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3595 const struct reserved_combo *r;
3597 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3598 if (strcmp(word->data, r->literal) == 0)
3603 static int reserved_word(o_string *word, struct parse_context *ctx)
3605 #if ENABLE_HUSH_CASE
3606 static const struct reserved_combo reserved_match = {
3607 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3610 const struct reserved_combo *r;
3612 r = match_reserved_word(word);
3616 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3617 #if ENABLE_HUSH_CASE
3618 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3619 /* "case word IN ..." - IN part starts first match part */
3620 r = &reserved_match;
3623 if (r->flag == 0) { /* '!' */
3624 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3625 syntax("! ! command");
3626 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3628 ctx->ctx_inverted = 1;
3631 if (r->flag & FLAG_START) {
3632 struct parse_context *old;
3633 old = xmalloc(sizeof(*old));
3634 debug_printf_parse("push stack %p\n", old);
3635 *old = *ctx; /* physical copy */
3636 initialize_context(ctx);
3638 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3640 ctx->ctx_res_w = RES_SNTX;
3643 ctx->ctx_res_w = r->res;
3644 ctx->old_flag = r->flag;
3645 if (ctx->old_flag & FLAG_END) {
3646 struct parse_context *old;
3647 done_pipe(ctx, PIPE_SEQ);
3648 debug_printf_parse("pop stack %p\n", ctx->stack);
3650 old->command->group = ctx->list_head;
3651 old->command->grp_type = GRP_NORMAL;
3653 o_addstr(&old->as_string, ctx->as_string.data);
3654 o_free_unsafe(&ctx->as_string);
3655 old->command->group_as_string = xstrdup(old->as_string.data);
3656 debug_printf_parse("pop, remembering as:'%s'\n",
3657 old->command->group_as_string);
3659 *ctx = *old; /* physical copy */
3662 word->o_assignment = r->assignment_flag;
3667 /* Word is complete, look at it and update parsing context.
3668 * Normal return is 0. Syntax errors return 1.
3669 * Note: on return, word is reset, but not o_free'd!
3671 static int done_word(o_string *word, struct parse_context *ctx)
3673 struct command *command = ctx->command;
3675 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3676 if (word->length == 0 && word->nonnull == 0) {
3677 debug_printf_parse("done_word return 0: true null, ignored\n");
3680 /* If this word wasn't an assignment, next ones definitely
3681 * can't be assignments. Even if they look like ones. */
3682 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3683 && word->o_assignment != WORD_IS_KEYWORD
3685 word->o_assignment = NOT_ASSIGNMENT;
3687 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3688 command->assignment_cnt++;
3689 word->o_assignment = MAYBE_ASSIGNMENT;
3692 if (ctx->pending_redirect) {
3693 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3694 * only if run as "bash", not "sh" */
3695 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3696 word->o_assignment = NOT_ASSIGNMENT;
3697 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3699 /* "{ echo foo; } echo bar" - bad */
3700 /* NB: bash allows e.g.:
3701 * if true; then { echo foo; } fi
3702 * while if false; then false; fi do break; done
3704 if (command->group) {
3706 debug_printf_parse("done_word return 1: syntax error, "
3707 "groups and arglists don't mix\n");
3711 #if ENABLE_HUSH_CASE
3712 if (ctx->ctx_dsemicolon
3713 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3715 /* already done when ctx_dsemicolon was set to 1: */
3716 /* ctx->ctx_res_w = RES_MATCH; */
3717 ctx->ctx_dsemicolon = 0;
3720 if (!command->argv /* if it's the first word... */
3721 #if ENABLE_HUSH_LOOPS
3722 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3723 && ctx->ctx_res_w != RES_IN
3726 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3727 if (reserved_word(word, ctx)) {
3729 debug_printf_parse("done_word return %d\n",
3730 (ctx->ctx_res_w == RES_SNTX));
3731 return (ctx->ctx_res_w == RES_SNTX);
3735 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3736 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3737 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3738 /* (otherwise it's known to be not empty and is already safe) */
3740 /* exclude "$@" - it can expand to no word despite "" */
3741 char *p = word->data;
3742 while (p[0] == SPECIAL_VAR_SYMBOL
3743 && (p[1] & 0x7f) == '@'
3744 && p[2] == SPECIAL_VAR_SYMBOL
3748 if (p == word->data || p[0] != '\0') {
3749 /* saw no "$@", or not only "$@" but some
3750 * real text is there too */
3751 /* insert "empty variable" reference, this makes
3752 * e.g. "", $empty"" etc to not disappear */
3753 o_addchr(word, SPECIAL_VAR_SYMBOL);
3754 o_addchr(word, SPECIAL_VAR_SYMBOL);
3757 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3758 debug_print_strings("word appended to argv", command->argv);
3762 ctx->pending_redirect = NULL;
3764 #if ENABLE_HUSH_LOOPS
3765 /* Force FOR to have just one word (variable name) */
3766 /* NB: basically, this makes hush see "for v in ..." syntax as if
3767 * as it is "for v; in ...". FOR and IN become two pipe structs
3769 if (ctx->ctx_res_w == RES_FOR) {
3770 //TODO: check that command->argv[0] is a valid variable name!
3771 done_pipe(ctx, PIPE_SEQ);
3774 #if ENABLE_HUSH_CASE
3775 /* Force CASE to have just one word */
3776 if (ctx->ctx_res_w == RES_CASE) {
3777 done_pipe(ctx, PIPE_SEQ);
3780 debug_printf_parse("done_word return 0\n");
3784 /* If a redirect is immediately preceded by a number, that number is
3785 * supposed to tell which file descriptor to redirect. This routine
3786 * looks for such preceding numbers. In an ideal world this routine
3787 * needs to handle all the following classes of redirects...
3788 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3789 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3790 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3791 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3792 * A -1 output from this program means no valid number was found, so the
3793 * caller should use the appropriate default for this redirection.
3795 static int redirect_opt_num(o_string *o)
3801 for (num = 0; num < o->length; num++) {
3802 if (!isdigit(o->data[num])) {
3806 num = atoi(o->data);
3812 #define parse_stream(pstring, input, end_trigger) \
3813 parse_stream(input, end_trigger)
3815 static struct pipe *parse_stream(char **pstring,
3816 struct in_str *input,
3818 static void parse_and_run_string(const char *s);
3820 #if ENABLE_HUSH_TICK
3821 static FILE *generate_stream_from_string(const char *s)
3824 int pid, channel[2];
3827 pid = BB_MMU ? fork() : vfork();
3829 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3831 if (pid == 0) { /* child */
3833 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
3835 /* Process substitution is not considered to be usual
3836 * 'command execution'.
3837 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3844 close(channel[0]); /* NB: close _first_, then move fd! */
3845 xmove_fd(channel[1], 1);
3846 /* Prevent it from trying to handle ctrl-z etc */
3847 USE_HUSH_JOB(G.run_list_level = 1;)
3849 parse_and_run_string(s);
3850 _exit(G.last_return_code);
3852 /* We re-execute after vfork on NOMMU. This makes this script safe:
3853 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
3854 * huge=`cat BIG` # was blocking here forever
3857 re_execute_shell(s);
3863 die_sleep = -1; /* restore tty pgrp on xfunc death */
3865 clean_up_after_re_execute();
3867 pf = fdopen(channel[0], "r");
3871 /* Return code is exit status of the process that is run. */
3872 static int process_command_subs(o_string *dest, const char *s)
3875 struct in_str pipe_str;
3878 pf = generate_stream_from_string(s);
3881 close_on_exec_on(fileno(pf));
3883 /* Now send results of command back into original context */
3884 setup_file_in_str(&pipe_str, pf);
3886 while ((ch = i_getch(&pipe_str)) != EOF) {
3892 o_addchr(dest, '\n');
3895 o_addQchr(dest, ch);
3898 debug_printf("done reading from pipe, pclose()ing\n");
3899 /* Note: we got EOF, and we just close the read end of the pipe.
3900 * We do not wait for the `cmd` child to terminate. bash and ash do.
3902 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
3903 * `false`; echo $? - bash outputs "1"
3906 debug_printf("closed FILE from child. return 0\n");
3911 static int parse_group(o_string *dest, struct parse_context *ctx,
3912 struct in_str *input, int ch)
3914 /* dest contains characters seen prior to ( or {.
3915 * Typically it's empty, but for function defs,
3916 * it contains function name (without '()'). */
3917 struct pipe *pipe_list;
3919 struct command *command = ctx->command;
3921 debug_printf_parse("parse_group entered\n");
3922 #if ENABLE_HUSH_FUNCTIONS
3923 if (ch == 'F') { /* function definition? */
3924 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3925 //command->fname = dest->data;
3926 command->grp_type = GRP_FUNCTION;
3927 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3928 memset(dest, 0, sizeof(*dest));
3931 if (command->argv /* word [word](... */
3932 || dest->length /* word(... */
3933 || dest->nonnull /* ""(... */
3936 debug_printf_parse("parse_group return 1: "
3937 "syntax error, groups and arglists don't mix\n");
3943 command->grp_type = GRP_SUBSHELL;
3947 char *as_string = NULL;
3949 pipe_list = parse_stream(&as_string, input, endch);
3952 o_addstr(&ctx->as_string, as_string);
3954 /* empty ()/{} or parse error? */
3955 if (!pipe_list || pipe_list == ERR_PTR) {
3960 debug_printf_parse("parse_group return 1: "
3961 "parse_stream returned %p\n", pipe_list);
3964 command->group = pipe_list;
3966 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3967 command->group_as_string = as_string;
3968 debug_printf_parse("end of group, remembering as:'%s'\n",
3969 command->group_as_string);
3972 debug_printf_parse("parse_group return 0\n");
3974 /* command remains "open", available for possible redirects */
3977 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
3978 /* Subroutines for copying $(...) and `...` things */
3979 static void add_till_backquote(o_string *dest, struct in_str *input);
3981 static void add_till_single_quote(o_string *dest, struct in_str *input)
3984 int ch = i_getch(input);
3992 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3993 static void add_till_double_quote(o_string *dest, struct in_str *input)
3996 int ch = i_getch(input);
3999 if (ch == '\\') { /* \x. Copy both chars. */
4001 ch = i_getch(input);
4007 add_till_backquote(dest, input);
4011 //if (ch == '$') ...
4014 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4016 * "Within the backquoted style of command substitution, backslash
4017 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4018 * The search for the matching backquote shall be satisfied by the first
4019 * backquote found without a preceding backslash; during this search,
4020 * if a non-escaped backquote is encountered within a shell comment,
4021 * a here-document, an embedded command substitution of the $(command)
4022 * form, or a quoted string, undefined results occur. A single-quoted
4023 * or double-quoted string that begins, but does not end, within the
4024 * "`...`" sequence produces undefined results."
4026 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4028 static void add_till_backquote(o_string *dest, struct in_str *input)
4031 int ch = i_getch(input);
4034 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4035 int ch2 = i_getch(input);
4036 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4045 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4046 * quoting and nested ()s.
4047 * "With the $(command) style of command substitution, all characters
4048 * following the open parenthesis to the matching closing parenthesis
4049 * constitute the command. Any valid shell script can be used for command,
4050 * except a script consisting solely of redirections which produces
4051 * unspecified results."
4053 * echo $(echo '(TEST)' BEST) (TEST) BEST
4054 * echo $(echo 'TEST)' BEST) TEST) BEST
4055 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4057 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4061 int ch = i_getch(input);
4070 if (i_peek(input) == ')') {
4078 add_till_single_quote(dest, input);
4083 add_till_double_quote(dest, input);
4087 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4088 ch = i_getch(input);
4096 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4098 /* Return code: 0 for OK, 1 for syntax error */
4100 #define handle_dollar(ctx, dest, input) \
4101 handle_dollar(dest, input)
4103 static int handle_dollar(struct parse_context *ctx,
4105 struct in_str *input)
4108 int ch = i_peek(input); /* first character after the $ */
4109 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4111 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4113 ch = i_getch(input);
4115 if (ctx) o_addchr(&ctx->as_string, ch);
4118 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4120 debug_printf_parse(": '%c'\n", ch);
4121 o_addchr(dest, ch | quote_mask);
4124 if (!isalnum(ch) && ch != '_')
4126 ch = i_getch(input);
4128 if (ctx) o_addchr(&ctx->as_string, ch);
4131 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4132 } else if (isdigit(ch)) {
4134 ch = i_getch(input);
4136 if (ctx) o_addchr(&ctx->as_string, ch);
4138 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4139 debug_printf_parse(": '%c'\n", ch);
4140 o_addchr(dest, ch | quote_mask);
4141 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4142 } else switch (ch) {
4144 case '!': /* last bg pid */
4145 case '?': /* last exit code */
4146 case '#': /* number of args */
4147 case '*': /* args */
4148 case '@': /* args */
4149 goto make_one_char_var;
4151 bool first_char, all_digits;
4153 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4154 ch = i_getch(input);
4156 if (ctx) o_addchr(&ctx->as_string, ch);
4158 /* XXX maybe someone will try to escape the '}' */
4163 ch = i_getch(input);
4165 if (ctx) o_addchr(&ctx->as_string, ch);
4172 /* ${#var}: length of var contents */
4174 else if (isdigit(ch)) {
4181 && ( (all_digits && !isdigit(ch))
4182 || (!all_digits && !isalnum(ch) && ch != '_')
4185 /* handle parameter expansions
4186 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4191 case ':': /* null modifier */
4192 if (expansion == 0) {
4193 debug_printf_parse(": null modifier\n");
4198 #if 0 /* not implemented yet :( */
4199 case '#': /* remove prefix */
4200 case '%': /* remove suffix */
4201 if (expansion == 0) {
4202 debug_printf_parse(": remove suffix/prefix\n");
4208 case '-': /* default value */
4209 case '=': /* assign default */
4210 case '+': /* alternative */
4211 case '?': /* error indicate */
4212 debug_printf_parse(": parameter expansion\n");
4217 syntax("unterminated ${name}");
4218 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4223 debug_printf_parse(": '%c'\n", ch);
4224 o_addchr(dest, ch | quote_mask);
4228 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4231 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4236 ch = i_getch(input);
4238 if (ctx) o_addchr(&ctx->as_string, ch);
4240 # if ENABLE_SH_MATH_SUPPORT
4241 if (i_peek(input) == '(') {
4242 ch = i_getch(input);
4244 if (ctx) o_addchr(&ctx->as_string, ch);
4246 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4247 o_addchr(dest, /*quote_mask |*/ '+');
4251 add_till_closing_paren(dest, input, true);
4254 o_addstr(&ctx->as_string, dest->data + pos);
4255 o_addchr(&ctx->as_string, ')');
4256 o_addchr(&ctx->as_string, ')');
4259 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4263 # if ENABLE_HUSH_TICK
4264 //int pos = dest->length;
4265 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4266 o_addchr(dest, quote_mask | '`');
4270 add_till_closing_paren(dest, input, false);
4273 o_addstr(&ctx->as_string, dest->data + pos);
4274 o_addchr(&ctx->as_string, '`');
4277 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4278 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4284 ch = i_getch(input);
4286 if (ctx) o_addchr(&ctx->as_string, ch);
4289 if (isalnum(ch)) { /* it's $_name or $_123 */
4295 /* $_ Shell or shell script name; or last cmd name */
4296 /* $- Option flags set by set builtin or shell options (-i etc) */
4298 o_addQchr(dest, '$');
4300 debug_printf_parse("handle_dollar return 0\n");
4305 #define parse_stream_dquoted(ctx, dest, input, dquote_end) \
4306 parse_stream_dquoted(dest, input, dquote_end)
4308 static int parse_stream_dquoted(struct parse_context *ctx,
4310 struct in_str *input,
4317 ch = i_getch(input);
4319 if (ctx && ch != EOF)
4320 o_addchr(&ctx->as_string, ch);
4322 if (ch == dquote_end) { /* may be only '"' or EOF */
4324 if (dest->o_assignment == NOT_ASSIGNMENT)
4325 dest->o_escape ^= 1;
4326 debug_printf_parse("parse_stream_dquoted return 0\n");
4330 syntax("unterminated \"");
4331 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4336 next = i_peek(input);
4338 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4339 ch, ch, dest->o_escape);
4343 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4347 * "The backslash retains its special meaning [in "..."]
4348 * only when followed by one of the following characters:
4349 * $, `, ", \, or <newline>. A double quote may be quoted
4350 * within double quotes by preceding it with a backslash.
4351 * If enabled, history expansion will be performed unless
4352 * an ! appearing in double quotes is escaped using
4353 * a backslash. The backslash preceding the ! is not removed."
4355 if (strchr("$`\"\\", next) != NULL) {
4356 o_addqchr(dest, i_getch(input));
4358 o_addqchr(dest, '\\');
4363 if (handle_dollar(ctx, dest, input) != 0) {
4364 debug_printf_parse("parse_stream_dquoted return 1: "
4365 "handle_dollar returned non-0\n");
4370 #if ENABLE_HUSH_TICK
4372 //int pos = dest->length;
4373 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4374 o_addchr(dest, 0x80 | '`');
4375 add_till_backquote(dest, input);
4376 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4377 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4381 o_addQchr(dest, ch);
4383 && (dest->o_assignment == MAYBE_ASSIGNMENT
4384 || dest->o_assignment == WORD_IS_KEYWORD)
4385 && is_assignment(dest->data)
4387 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4393 * Scan input until EOF or end_trigger char.
4394 * Return a list of pipes to execute, or NULL on EOF
4395 * or if end_trigger character is met.
4396 * On syntax error, exit is shell is not interactive,
4397 * reset parsing machinery and start parsing anew,
4398 * or return ERR_PTR.
4400 static struct pipe *parse_stream(char **pstring,
4401 struct in_str *input,
4404 struct parse_context ctx;
4405 o_string dest = NULL_O_STRING;
4408 /* Double-quote state is handled in the state variable is_in_dquote.
4409 * A single-quote triggers a bypass of the main loop until its mate is
4410 * found. When recursing, quote state is passed in via dest->o_escape.
4412 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4413 end_trigger ? : 'X');
4415 G.ifs = get_local_var_value("IFS");
4420 #if ENABLE_HUSH_INTERACTIVE
4421 input->promptmode = 0; /* PS1 */
4423 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4424 initialize_context(&ctx);
4428 const char *is_special;
4432 redir_type redir_style;
4435 if (parse_stream_dquoted(&ctx, &dest, input, '"')) {
4438 /* We reached closing '"' */
4441 ch = i_getch(input);
4442 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4443 ch, ch, dest.o_escape);
4446 if (done_word(&dest, &ctx)) {
4450 done_pipe(&ctx, PIPE_SEQ);
4452 /* If we got nothing... */
4453 // TODO: test script consisting of just "&"
4454 if (pi->num_cmds == 0
4455 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4457 free_pipe_list(pi, 0);
4460 debug_printf_parse("parse_stream return %p\n", pi);
4462 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4464 *pstring = ctx.as_string.data;
4466 o_free_unsafe(&ctx.as_string);
4471 o_addchr(&ctx.as_string, ch);
4473 is_ifs = strchr(G.ifs, ch);
4474 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4475 "\\$\"" USE_HUSH_TICK("`") /* always special */
4478 if (!is_special && !is_ifs) { /* ordinary char */
4479 o_addQchr(&dest, ch);
4480 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4481 || dest.o_assignment == WORD_IS_KEYWORD)
4483 && is_assignment(dest.data)
4485 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4491 if (done_word(&dest, &ctx)) {
4495 #if ENABLE_HUSH_CASE
4496 /* "case ... in <newline> word) ..." -
4497 * newlines are ignored (but ';' wouldn't be) */
4498 if (ctx.command->argv == NULL
4499 && ctx.ctx_res_w == RES_MATCH
4504 /* Treat newline as a command separator. */
4505 done_pipe(&ctx, PIPE_SEQ);
4506 dest.o_assignment = MAYBE_ASSIGNMENT;
4508 /* note: if (is_ifs) continue;
4509 * will still trigger for us */
4512 if (end_trigger && end_trigger == ch) {
4513 //TODO: disallow "{ cmd }" without semicolon
4514 if (done_word(&dest, &ctx)) {
4517 done_pipe(&ctx, PIPE_SEQ);
4518 dest.o_assignment = MAYBE_ASSIGNMENT;
4519 /* Do we sit outside of any if's, loops or case's? */
4521 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4523 debug_printf_parse("parse_stream return %p: "
4524 "end_trigger char found\n",
4528 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4530 *pstring = ctx.as_string.data;
4532 o_free_unsafe(&ctx.as_string);
4534 return ctx.list_head;
4540 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4541 /* ch is a special char and thus this word
4542 * cannot be an assignment */
4543 dest.o_assignment = NOT_ASSIGNMENT;
4548 next = i_peek(input);
4553 if (dest.length == 0) {
4556 if (ch == EOF || ch == '\n')
4559 /* note: we do not add it to &ctx.as_string */
4562 //TODO: go back one char?
4563 o_addchr(&ctx.as_string, '\n');
4566 o_addQchr(&dest, ch);
4574 o_addchr(&dest, '\\');
4575 ch = i_getch(input);
4576 o_addchr(&dest, ch);
4578 o_addchr(&ctx.as_string, ch);
4583 if (handle_dollar(&ctx, &dest, input) != 0) {
4584 debug_printf_parse("parse_stream parse error: "
4585 "handle_dollar returned non-0\n");
4592 ch = i_getch(input);
4594 syntax("unterminated '");
4598 o_addchr(&ctx.as_string, ch);
4602 if (dest.o_assignment == NOT_ASSIGNMENT)
4603 o_addqchr(&dest, ch);
4605 o_addchr(&dest, ch);
4610 is_in_dquote ^= 1; /* invert */
4611 if (dest.o_assignment == NOT_ASSIGNMENT)
4614 #if ENABLE_HUSH_TICK
4616 //int pos = dest.length;
4617 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4618 o_addchr(&dest, '`');
4619 add_till_backquote(&dest, input);
4620 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4621 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4626 redir_fd = redirect_opt_num(&dest);
4627 if (done_word(&dest, &ctx)) {
4630 redir_style = REDIRECT_OVERWRITE;
4632 redir_style = REDIRECT_APPEND;
4633 ch = i_getch(input);
4635 o_addchr(&ctx.as_string, ch);
4639 else if (next == '(') {
4640 syntax(">(process) not supported");
4644 setup_redirect(&ctx, redir_fd, redir_style, input);
4647 redir_fd = redirect_opt_num(&dest);
4648 if (done_word(&dest, &ctx)) {
4651 redir_style = REDIRECT_INPUT;
4653 redir_style = REDIRECT_HEREIS;
4654 ch = i_getch(input);
4656 o_addchr(&ctx.as_string, ch);
4658 } else if (next == '>') {
4659 redir_style = REDIRECT_IO;
4660 ch = i_getch(input);
4662 o_addchr(&ctx.as_string, ch);
4666 else if (next == '(') {
4667 syntax("<(process) not supported");
4671 setup_redirect(&ctx, redir_fd, redir_style, input);
4674 #if ENABLE_HUSH_CASE
4677 if (done_word(&dest, &ctx)) {
4680 done_pipe(&ctx, PIPE_SEQ);
4681 #if ENABLE_HUSH_CASE
4682 /* Eat multiple semicolons, detect
4683 * whether it means something special */
4688 ch = i_getch(input);
4690 o_addchr(&ctx.as_string, ch);
4692 if (ctx.ctx_res_w == RES_CASEI) {
4693 ctx.ctx_dsemicolon = 1;
4694 ctx.ctx_res_w = RES_MATCH;
4700 /* We just finished a cmd. New one may start
4701 * with an assignment */
4702 dest.o_assignment = MAYBE_ASSIGNMENT;
4705 if (done_word(&dest, &ctx)) {
4709 ch = i_getch(input);
4711 o_addchr(&ctx.as_string, ch);
4713 done_pipe(&ctx, PIPE_AND);
4715 done_pipe(&ctx, PIPE_BG);
4719 if (done_word(&dest, &ctx)) {
4722 #if ENABLE_HUSH_CASE
4723 if (ctx.ctx_res_w == RES_MATCH)
4724 break; /* we are in case's "word | word)" */
4726 if (next == '|') { /* || */
4727 ch = i_getch(input);
4729 o_addchr(&ctx.as_string, ch);
4731 done_pipe(&ctx, PIPE_OR);
4733 /* we could pick up a file descriptor choice here
4734 * with redirect_opt_num(), but bash doesn't do it.
4735 * "echo foo 2| cat" yields "foo 2". */
4740 #if ENABLE_HUSH_CASE
4741 /* "case... in [(]word)..." - skip '(' */
4742 if (ctx.ctx_res_w == RES_MATCH
4743 && ctx.command->argv == NULL /* not (word|(... */
4744 && dest.length == 0 /* not word(... */
4745 && dest.nonnull == 0 /* not ""(... */
4750 #if ENABLE_HUSH_FUNCTIONS
4751 if (dest.length != 0 /* not just () but word() */
4752 && dest.nonnull == 0 /* not a"b"c() */
4753 && ctx.command->argv == NULL /* it's the first word */
4754 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4755 && i_peek(input) == ')'
4756 && !match_reserved_word(&dest)
4758 bb_error_msg("seems like a function definition");
4760 //if !BB_MMU o_addchr(&ctx.as_string...
4762 //TODO: do it properly.
4763 ch = i_getch(input);
4764 } while (ch == ' ' || ch == '\n');
4766 syntax("was expecting {");
4769 ch = 'F'; /* magic value */
4773 if (parse_group(&dest, &ctx, input, ch) != 0) {
4778 #if ENABLE_HUSH_CASE
4779 if (ctx.ctx_res_w == RES_MATCH)
4783 /* proper use of this character is caught by end_trigger:
4784 * if we see {, we call parse_group(..., end_trigger='}')
4785 * and it will match } earlier (not here). */
4786 syntax("unexpected } or )");
4790 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4796 struct parse_context *pctx;
4797 IF_HAS_KEYWORDS(struct parse_context *p2;)
4799 /* Clean up allocated tree.
4800 * Samples for finding leaks on syntax error recovery path.
4801 * Run them from interactive shell, watch pmap `pidof hush`.
4802 * while if false; then false; fi do break; done
4804 * while if false; then false; fi; do break; fi
4805 * Samples to catch leaks at execution:
4806 * while if (true | {true;}); then echo ok; fi; do break; done
4807 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4811 /* Update pipe/command counts,
4812 * otherwise freeing may miss some */
4813 done_pipe(pctx, PIPE_SEQ);
4814 debug_printf_clean("freeing list %p from ctx %p\n",
4815 pctx->list_head, pctx);
4816 debug_print_tree(pctx->list_head, 0);
4817 free_pipe_list(pctx->list_head, 0);
4818 debug_printf_clean("freed list %p\n", pctx->list_head);
4820 o_free_unsafe(&pctx->as_string);
4822 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4826 IF_HAS_KEYWORDS(pctx = p2;)
4827 } while (HAS_KEYWORDS && pctx);
4828 /* Free text, clear all dest fields */
4830 /* If we are not in top-level parse, we return,
4831 * our caller will propagate error.
4833 if (end_trigger != ';') {
4840 /* Discard cached input, force prompt */
4842 USE_HUSH_INTERACTIVE(input->promptme = 1;)
4847 /* Executing from string: eval, sh -c '...'
4848 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4849 * end_trigger controls how often we stop parsing
4850 * NUL: parse all, execute, return
4851 * ';': parse till ';' or newline, execute, repeat till EOF
4853 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4856 struct pipe *pipe_list;
4858 pipe_list = parse_stream(NULL, inp, end_trigger);
4859 if (!pipe_list) /* EOF */
4861 debug_print_tree(pipe_list, 0);
4862 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4863 run_and_free_list(pipe_list);
4867 static void parse_and_run_string(const char *s)
4869 struct in_str input;
4870 setup_string_in_str(&input, s);
4871 parse_and_run_stream(&input, '\0');
4874 static void parse_and_run_file(FILE *f)
4876 struct in_str input;
4877 setup_file_in_str(&input, f);
4878 parse_and_run_stream(&input, ';');
4881 /* Called a few times only (or even once if "sh -c") */
4882 static void block_signals(int second_time)
4887 mask = (1 << SIGQUIT);
4888 if (G_interactive_fd) {
4894 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
4899 G.non_DFL_mask = mask;
4902 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
4906 sigaddset(&G.blocked_set, sig);
4910 sigdelset(&G.blocked_set, SIGCHLD);
4912 sigprocmask(SIG_SETMASK, &G.blocked_set,
4913 second_time ? NULL : &G.inherited_set);
4914 /* POSIX allows shell to re-enable SIGCHLD
4915 * even if it was SIG_IGN on entry */
4916 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4918 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4923 static void maybe_set_to_sigexit(int sig)
4925 void (*handler)(int);
4926 /* non_DFL_mask'ed signals are, well, masked,
4927 * no need to set handler for them.
4929 if (!((G.non_DFL_mask >> sig) & 1)) {
4930 handler = signal(sig, sigexit);
4931 if (handler == SIG_IGN) /* oops... restore back to IGN! */
4932 signal(sig, handler);
4935 /* Set handlers to restore tty pgrm and exit */
4936 static void set_fatal_handlers(void)
4938 /* We _must_ restore tty pgrp on fatal signals */
4940 maybe_set_to_sigexit(SIGILL );
4941 maybe_set_to_sigexit(SIGFPE );
4942 maybe_set_to_sigexit(SIGBUS );
4943 maybe_set_to_sigexit(SIGSEGV);
4944 maybe_set_to_sigexit(SIGTRAP);
4945 } /* else: hush is perfect. what SEGV? */
4946 maybe_set_to_sigexit(SIGABRT);
4947 /* bash 3.2 seems to handle these just like 'fatal' ones */
4948 maybe_set_to_sigexit(SIGPIPE);
4949 maybe_set_to_sigexit(SIGALRM);
4950 maybe_set_to_sigexit(SIGHUP );
4951 /* if we are interactive, SIGTERM and SIGINT are masked.
4952 * if we aren't interactive... but in this case
4953 * we never want to restore pgrp on exit, and this fn is not called */
4954 /*maybe_set_to_sigexit(SIGTERM);*/
4955 /*maybe_set_to_sigexit(SIGINT );*/
4959 static int set_mode(const char cstate, const char mode)
4961 int state = (cstate == '-' ? 1 : 0);
4963 case 'n': G.fake_mode = state; break;
4964 case 'x': /*G.debug_mode = state;*/ break;
4965 default: return EXIT_FAILURE;
4967 return EXIT_SUCCESS;
4970 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4971 int hush_main(int argc, char **argv)
4973 static const struct variable const_shell_ver = {
4975 .varstr = (char*)hush_version_str,
4976 .max_len = 1, /* 0 can provoke free(name) */
4980 int signal_mask_is_inited = 0;
4983 struct variable *cur_var;
4986 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
4987 G.last_return_code = EXIT_SUCCESS;
4989 G.argv0_for_re_execing = argv[0];
4991 /* Deal with HUSH_VERSION */
4992 G.shell_ver = const_shell_ver; /* copying struct here */
4993 G.top_var = &G.shell_ver;
4994 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4995 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4996 /* Initialize our shell local variables with the values
4997 * currently living in the environment */
4998 cur_var = G.top_var;
5001 char *value = strchr(*e, '=');
5002 if (value) { /* paranoia */
5003 cur_var->next = xzalloc(sizeof(*cur_var));
5004 cur_var = cur_var->next;
5005 cur_var->varstr = *e;
5006 cur_var->max_len = strlen(*e);
5007 cur_var->flg_export = 1;
5011 debug_printf_env("putenv '%s'\n", hush_version_str);
5012 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5013 #if ENABLE_FEATURE_EDITING
5014 G.line_input_state = new_line_input_t(FOR_SHELL);
5016 G.global_argc = argc;
5017 G.global_argv = argv;
5018 /* Initialize some more globals to non-zero values */
5020 #if ENABLE_HUSH_INTERACTIVE
5021 if (ENABLE_FEATURE_EDITING)
5022 cmdedit_set_initial_prompt();
5026 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5028 opt = getopt(argc, argv, "c:xins"
5038 G.root_pid = getpid();
5039 G.global_argv = argv + optind;
5040 if (!argv[optind]) {
5041 /* -c 'script' (no params): prevent empty $0 */
5042 *--G.global_argv = argv[0];
5044 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5045 G.global_argc = argc - optind;
5046 block_signals(0); /* 0: called 1st time */
5047 parse_and_run_string(optarg);
5050 /* Well, we cannot just declare interactiveness,
5051 * we have to have some stuff (ctty, etc) */
5052 /* G_interactive_fd++; */
5055 /* "-s" means "read from stdin", but this is how we always
5056 * operate, so simply do nothing here. */
5060 G.root_pid = xatoi_u(optarg);
5063 G.last_bg_pid = xatoi_u(optarg);
5066 G.last_return_code = xatoi_u(optarg);
5068 #if ENABLE_HUSH_LOOPS
5070 G.depth_of_loop = xatoi_u(optarg);
5075 set_local_var(xstrdup(optarg), 0, opt == 'R');
5080 if (!set_mode('-', opt))
5084 fprintf(stderr, "Usage: sh [FILE]...\n"
5085 " or: sh -c command [args]...\n\n");
5091 } /* option parsing loop */
5094 G.root_pid = getpid();
5096 /* If we are login shell... */
5097 if (argv[0] && argv[0][0] == '-') {
5099 /* XXX what should argv be while sourcing /etc/profile? */
5100 debug_printf("sourcing /etc/profile\n");
5101 input = fopen_for_read("/etc/profile");
5102 if (input != NULL) {
5103 close_on_exec_on(fileno(input));
5104 block_signals(0); /* 0: called 1st time */
5105 signal_mask_is_inited = 1;
5106 parse_and_run_file(input);
5109 /* bash: after sourcing /etc/profile,
5110 * tries to source (in the given order):
5111 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5112 * stopping of first found. --noprofile turns this off.
5113 * bash also sources ~/.bash_logout on exit.
5114 * If called as sh, skips .bash_XXX files.
5121 * Non-interactive "bash <script>" sources $BASH_ENV here
5122 * (without scanning $PATH).
5123 * If called as sh, does the same but with $ENV.
5125 debug_printf("running script '%s'\n", argv[optind]);
5126 G.global_argv = argv + optind;
5127 G.global_argc = argc - optind;
5128 input = xfopen_for_read(argv[optind]);
5129 close_on_exec_on(fileno(input));
5130 if (!signal_mask_is_inited)
5131 block_signals(0); /* 0: called 1st time */
5132 parse_and_run_file(input);
5133 #if ENABLE_FEATURE_CLEAN_UP
5139 /* Up to here, shell was non-interactive. Now it may become one. */
5141 /* A shell is interactive if the '-i' flag was given, or if all of
5142 * the following conditions are met:
5144 * no arguments remaining or the -s flag given
5145 * standard input is a terminal
5146 * standard output is a terminal
5147 * Refer to Posix.2, the description of the 'sh' utility.
5150 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5151 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5152 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5153 if (G.saved_tty_pgrp >= 0) {
5154 /* try to dup stdin to high fd#, >= 255 */
5155 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5156 if (G_interactive_fd < 0) {
5157 /* try to dup to any fd */
5158 G_interactive_fd = dup(STDIN_FILENO);
5159 if (G_interactive_fd < 0)
5161 G_interactive_fd = 0;
5163 // TODO: track & disallow any attempts of user
5164 // to (inadvertently) close/redirect it
5167 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5168 if (G_interactive_fd) {
5171 /* We are indeed interactive shell, and we will perform
5172 * job control. Setting up for that. */
5174 close_on_exec_on(G_interactive_fd);
5175 /* If we were run as 'hush &', sleep until we are
5176 * in the foreground (tty pgrp == our pgrp).
5177 * If we get started under a job aware app (like bash),
5178 * make sure we are now in charge so we don't fight over
5179 * who gets the foreground */
5181 shell_pgrp = getpgrp();
5182 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5183 if (G.saved_tty_pgrp == shell_pgrp)
5185 /* send TTIN to ourself (should stop us) */
5186 kill(- shell_pgrp, SIGTTIN);
5188 /* Block some signals */
5189 block_signals(signal_mask_is_inited);
5190 /* Set other signals to restore saved_tty_pgrp */
5191 set_fatal_handlers();
5192 /* Put ourselves in our own process group */
5193 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5194 /* Grab control of the terminal */
5195 tcsetpgrp(G_interactive_fd, getpid());
5196 /* -1 is special - makes xfuncs longjmp, not exit
5197 * (we reset die_sleep = 0 whereever we [v]fork) */
5199 if (setjmp(die_jmp)) {
5200 /* xfunc has failed! die die die */
5201 hush_exit(xfunc_error_retval);
5203 } else if (!signal_mask_is_inited) {
5204 block_signals(0); /* 0: called 1st time */
5205 } /* else: block_signals(0) was done before */
5206 #elif ENABLE_HUSH_INTERACTIVE
5207 /* No job control compiled in, only prompt/line editing */
5208 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5209 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5210 if (G_interactive_fd < 0) {
5211 /* try to dup to any fd */
5212 G_interactive_fd = dup(STDIN_FILENO);
5213 if (G_interactive_fd < 0)
5215 G_interactive_fd = 0;
5218 if (G_interactive_fd) {
5219 close_on_exec_on(G_interactive_fd);
5220 block_signals(signal_mask_is_inited);
5221 } else if (!signal_mask_is_inited) {
5225 /* We have interactiveness code disabled */
5226 if (!signal_mask_is_inited) {
5231 * if interactive but not a login shell, sources ~/.bashrc
5232 * (--norc turns this off, --rcfile <file> overrides)
5235 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5236 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
5237 printf("Enter 'help' for a list of built-in commands.\n\n");
5240 parse_and_run_file(stdin);
5243 #if ENABLE_FEATURE_CLEAN_UP
5244 if (G.cwd != bb_msg_unknown)
5246 cur_var = G.top_var->next;
5248 struct variable *tmp = cur_var;
5249 if (!cur_var->max_len)
5250 free(cur_var->varstr);
5251 cur_var = cur_var->next;
5255 hush_exit(G.last_return_code);
5260 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5261 int lash_main(int argc, char **argv)
5263 //bb_error_msg("lash is deprecated, please use hush instead");
5264 return hush_main(argc, argv);
5272 static int builtin_trap(char **argv)
5279 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5282 /* No args: print all trapped. This isn't 100% correct as we should
5283 * be escaping the cmd so that it can be pasted back in ...
5285 for (i = 0; i < NSIG; ++i)
5287 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5288 return EXIT_SUCCESS;
5293 /* if first arg is decimal: reset all specified */
5294 sig = bb_strtou(*++argv, NULL, 10);
5300 sig = get_signum(*argv++);
5301 if (sig < 0 || sig >= NSIG) {
5303 /* mimic bash message exactly */
5304 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5309 G.traps[sig] = xstrdup(new_cmd);
5311 debug_printf("trap: setting SIG%s (%i) to '%s'",
5312 get_signame(sig), sig, G.traps[sig]);
5314 /* There is no signal for 0 (EXIT) */
5319 sigaddset(&G.blocked_set, sig);
5321 /* there was a trap handler, we are removing it
5322 * (if sig has non-DFL handling,
5323 * we don't need to do anything) */
5324 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5326 sigdelset(&G.blocked_set, sig);
5328 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5333 /* first arg is "-": reset all specified to default */
5334 /* first arg is "": ignore all specified */
5335 /* everything else: execute first arg upon signal */
5337 bb_error_msg("trap: invalid arguments");
5338 return EXIT_FAILURE;
5340 if (LONE_DASH(*argv))
5348 static int builtin_true(char **argv UNUSED_PARAM)
5353 static int builtin_test(char **argv)
5360 return test_main(argc, argv - argc);
5363 static int builtin_echo(char **argv)
5370 return echo_main(argc, argv - argc);
5373 static int builtin_eval(char **argv)
5375 int rcode = EXIT_SUCCESS;
5378 char *str = expand_strvec_to_string(argv + 1);
5380 * eval "echo Hi; done" ("done" is syntax error):
5381 * "echo Hi" will not execute too.
5383 parse_and_run_string(str);
5385 rcode = G.last_return_code;
5390 static int builtin_cd(char **argv)
5393 if (argv[1] == NULL) {
5394 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5395 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5397 newdir = getenv("HOME") ? : "/";
5400 if (chdir(newdir)) {
5401 printf("cd: %s: %s\n", newdir, strerror(errno));
5402 return EXIT_FAILURE;
5405 return EXIT_SUCCESS;
5408 static int builtin_exec(char **argv)
5410 if (argv[1] == NULL)
5411 return EXIT_SUCCESS; /* bash does this */
5416 // FIXME: if exec fails, bash does NOT exit! We do...
5417 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
5422 static int builtin_exit(char **argv)
5424 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5425 //puts("exit"); /* bash does it */
5426 // TODO: warn if we have background jobs: "There are stopped jobs"
5427 // On second consecutive 'exit', exit anyway.
5428 if (argv[1] == NULL)
5429 hush_exit(G.last_return_code);
5430 /* mimic bash: exit 123abc == exit 255 + error msg */
5431 xfunc_error_retval = 255;
5432 /* bash: exit -2 == exit 254, no error msg */
5433 hush_exit(xatoi(argv[1]) & 0xff);
5436 static int builtin_export(char **argv)
5439 char *name = argv[1];
5443 // ash emits: export VAR='VAL'
5444 // bash: declare -x VAR="VAL"
5445 // (both also escape as needed (quotes, $, etc))
5450 return EXIT_SUCCESS;
5453 value = strchr(name, '=');
5455 /* They are exporting something without a =VALUE */
5456 struct variable *var;
5458 var = get_local_var(name);
5460 var->flg_export = 1;
5461 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5462 putenv(var->varstr);
5464 /* bash does not return an error when trying to export
5465 * an undefined variable. Do likewise. */
5466 return EXIT_SUCCESS;
5469 set_local_var(xstrdup(name), 1, 0);
5470 return EXIT_SUCCESS;
5474 /* built-in 'fg' and 'bg' handler */
5475 static int builtin_fg_bg(char **argv)
5480 if (!G_interactive_fd)
5481 return EXIT_FAILURE;
5482 /* If they gave us no args, assume they want the last backgrounded task */
5484 for (pi = G.job_list; pi; pi = pi->next) {
5485 if (pi->jobid == G.last_jobid) {
5489 bb_error_msg("%s: no current job", argv[0]);
5490 return EXIT_FAILURE;
5492 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5493 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5494 return EXIT_FAILURE;
5496 for (pi = G.job_list; pi; pi = pi->next) {
5497 if (pi->jobid == jobnum) {
5501 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5502 return EXIT_FAILURE;
5504 // TODO: bash prints a string representation
5505 // of job being foregrounded (like "sleep 1 | cat")
5506 if (argv[0][0] == 'f') {
5507 /* Put the job into the foreground. */
5508 tcsetpgrp(G_interactive_fd, pi->pgrp);
5511 /* Restart the processes in the job */
5512 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5513 for (i = 0; i < pi->num_cmds; i++) {
5514 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5515 pi->cmds[i].is_stopped = 0;
5517 pi->stopped_cmds = 0;
5519 i = kill(- pi->pgrp, SIGCONT);
5521 if (errno == ESRCH) {
5522 delete_finished_bg_job(pi);
5523 return EXIT_SUCCESS;
5525 bb_perror_msg("kill (SIGCONT)");
5528 if (argv[0][0] == 'f') {
5530 return checkjobs_and_fg_shell(pi);
5532 return EXIT_SUCCESS;
5536 #if ENABLE_HUSH_HELP
5537 static int builtin_help(char **argv UNUSED_PARAM)
5539 const struct built_in_command *x;
5542 "Built-in commands:\n"
5543 "------------------\n");
5544 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5545 printf("%s\t%s\n", x->cmd, x->descr);
5548 return EXIT_SUCCESS;
5553 static int builtin_jobs(char **argv UNUSED_PARAM)
5556 const char *status_string;
5558 for (job = G.job_list; job; job = job->next) {
5559 if (job->alive_cmds == job->stopped_cmds)
5560 status_string = "Stopped";
5562 status_string = "Running";
5564 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5566 return EXIT_SUCCESS;
5570 static int builtin_pwd(char **argv UNUSED_PARAM)
5573 return EXIT_SUCCESS;
5576 static int builtin_read(char **argv)
5579 const char *name = argv[1] ? argv[1] : "REPLY";
5581 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5582 return set_local_var(string, 0, 0);
5585 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5586 * built-in 'set' handler
5588 * set [-abCefhmnuvx] [-o option] [argument...]
5589 * set [+abCefhmnuvx] [+o option] [argument...]
5590 * set -- [argument...]
5593 * Implementations shall support the options in both their hyphen and
5594 * plus-sign forms. These options can also be specified as options to sh.
5596 * Write out all variables and their values: set
5597 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5598 * Turn on the -x and -v options: set -xv
5599 * Unset all positional parameters: set --
5600 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5601 * Set the positional parameters to the expansion of x, even if x expands
5602 * with a leading '-' or '+': set -- $x
5604 * So far, we only support "set -- [argument...]" and some of the short names.
5606 static int builtin_set(char **argv)
5609 char **pp, **g_argv;
5610 char *arg = *++argv;
5614 for (e = G.top_var; e; e = e->next)
5616 return EXIT_SUCCESS;
5620 if (!strcmp(arg, "--")) {
5625 if (arg[0] == '+' || arg[0] == '-') {
5626 for (n = 1; arg[n]; ++n)
5627 if (set_mode(arg[0], arg[n]))
5633 } while ((arg = *++argv) != NULL);
5634 /* Now argv[0] is 1st argument */
5636 /* Only reset global_argv if we didn't process anything */
5638 return EXIT_SUCCESS;
5641 /* NB: G.global_argv[0] ($0) is never freed/changed */
5642 g_argv = G.global_argv;
5643 if (G.global_args_malloced) {
5649 G.global_args_malloced = 1;
5650 pp = xzalloc(sizeof(pp[0]) * 2);
5651 pp[0] = g_argv[0]; /* retain $0 */
5654 /* This realloc's G.global_argv */
5655 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5662 return EXIT_SUCCESS;
5664 /* Nothing known, so abort */
5666 bb_error_msg("set: %s: invalid option", arg);
5667 return EXIT_FAILURE;
5670 static int builtin_shift(char **argv)
5676 if (n >= 0 && n < G.global_argc) {
5677 if (G.global_args_malloced) {
5680 free(G.global_argv[m++]);
5683 memmove(&G.global_argv[1], &G.global_argv[n+1],
5684 G.global_argc * sizeof(G.global_argv[0]));
5685 return EXIT_SUCCESS;
5687 return EXIT_FAILURE;
5690 static int builtin_source(char **argv)
5694 if (argv[1] == NULL)
5695 return EXIT_FAILURE;
5697 /* XXX search through $PATH is missing */
5698 input = fopen_for_read(argv[1]);
5700 bb_error_msg("can't open '%s'", argv[1]);
5701 return EXIT_FAILURE;
5703 close_on_exec_on(fileno(input));
5705 /* Now run the file */
5706 /* XXX argv and argc are broken; need to save old G.global_argv
5707 * (pointer only is OK!) on this stack frame,
5708 * set G.global_argv=argv+1, recurse, and restore. */
5709 parse_and_run_file(input);
5711 return G.last_return_code;
5714 static int builtin_umask(char **argv)
5717 const char *arg = argv[1];
5719 new_umask = bb_strtou(arg, NULL, 8);
5721 return EXIT_FAILURE;
5723 new_umask = umask(0);
5724 printf("%.3o\n", (unsigned) new_umask);
5727 return EXIT_SUCCESS;
5730 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5731 static int builtin_unset(char **argv)
5738 return EXIT_SUCCESS;
5741 if (argv[1][0] == '-') {
5742 switch (argv[1][1]) {
5744 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5746 bb_error_msg("unset: %s: invalid option", argv[1]);
5747 return EXIT_FAILURE;
5755 if (unset_local_var(argv[i]))
5758 #if ENABLE_HUSH_FUNCTIONS
5760 unset_local_func(argv[i]);
5766 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5767 static int builtin_wait(char **argv)
5769 int ret = EXIT_SUCCESS;
5772 if (*++argv == NULL) {
5773 /* Don't care about wait results */
5774 /* Note 1: must wait until there are no more children */
5775 /* Note 2: must be interruptible */
5777 * $ sleep 3 & sleep 6 & wait
5782 * $ sleep 3 & sleep 6 & wait
5786 * ^C <-- after ~4 sec from keyboard
5789 sigaddset(&G.blocked_set, SIGCHLD);
5790 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5793 if (errno == ECHILD)
5795 /* Wait for SIGCHLD or any other signal of interest */
5796 /* sigtimedwait with infinite timeout: */
5797 sig = sigwaitinfo(&G.blocked_set, NULL);
5799 sig = check_and_run_traps(sig);
5800 if (sig && sig != SIGCHLD) { /* see note 2 */
5806 sigdelset(&G.blocked_set, SIGCHLD);
5807 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5811 /* This is probably buggy wrt interruptible-ness */
5813 pid_t pid = bb_strtou(*argv, NULL, 10);
5815 /* mimic bash message */
5816 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5817 return EXIT_FAILURE;
5819 if (waitpid(pid, &status, 0) == pid) {
5820 if (WIFSIGNALED(status))
5821 ret = 128 + WTERMSIG(status);
5822 else if (WIFEXITED(status))
5823 ret = WEXITSTATUS(status);
5827 bb_perror_msg("wait %s", *argv);
5836 #if ENABLE_HUSH_LOOPS
5837 static int builtin_break(char **argv)
5839 if (G.depth_of_loop == 0) {
5840 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5841 return EXIT_SUCCESS; /* bash compat */
5843 G.flag_break_continue++; /* BC_BREAK = 1 */
5844 G.depth_break_continue = 1;
5846 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5847 if (errno || !G.depth_break_continue || argv[2]) {
5848 bb_error_msg("%s: bad arguments", argv[0]);
5849 G.flag_break_continue = BC_BREAK;
5850 G.depth_break_continue = UINT_MAX;
5853 if (G.depth_of_loop < G.depth_break_continue)
5854 G.depth_break_continue = G.depth_of_loop;
5855 return EXIT_SUCCESS;
5858 static int builtin_continue(char **argv)
5860 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5861 return builtin_break(argv);