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 #if defined SINGLE_APPLET_MAIN
88 /* STANDALONE does not make sense, and won't compile */
89 #undef CONFIG_FEATURE_SH_STANDALONE
90 #undef ENABLE_FEATURE_SH_STANDALONE
91 #undef USE_FEATURE_SH_STANDALONE
92 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
93 #define ENABLE_FEATURE_SH_STANDALONE 0
94 #define USE_FEATURE_SH_STANDALONE(...)
95 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
98 #if !ENABLE_HUSH_INTERACTIVE
99 #undef ENABLE_FEATURE_EDITING
100 #define ENABLE_FEATURE_EDITING 0
101 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
102 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
105 /* Do we support ANY keywords? */
106 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
107 #define HAS_KEYWORDS 1
108 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
109 #define IF_HAS_NO_KEYWORDS(...)
111 #define HAS_KEYWORDS 0
112 #define IF_HAS_KEYWORDS(...)
113 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
116 /* Keep unconditionally on for now */
119 #define ENABLE_HUSH_FUNCTIONS 0
122 /* If you comment out one of these below, it will be #defined later
123 * to perform debug printfs to stderr: */
124 #define debug_printf(...) do {} while (0)
125 /* Finer-grained debug switches */
126 #define debug_printf_parse(...) do {} while (0)
127 #define debug_print_tree(a, b) do {} while (0)
128 #define debug_printf_exec(...) do {} while (0)
129 #define debug_printf_env(...) do {} while (0)
130 #define debug_printf_jobs(...) do {} while (0)
131 #define debug_printf_expand(...) do {} while (0)
132 #define debug_printf_glob(...) do {} while (0)
133 #define debug_printf_list(...) do {} while (0)
134 #define debug_printf_subst(...) do {} while (0)
135 #define debug_printf_clean(...) do {} while (0)
138 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
141 #ifndef debug_printf_parse
142 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
145 #ifndef debug_printf_exec
146 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_env
150 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_jobs
154 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
160 #ifndef debug_printf_expand
161 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
162 #define DEBUG_EXPAND 1
164 #define DEBUG_EXPAND 0
167 #ifndef debug_printf_glob
168 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
174 #ifndef debug_printf_list
175 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
178 #ifndef debug_printf_subst
179 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_clean
183 /* broken, of course, but OK for testing */
184 static const char *indenter(int i)
186 static const char blanks[] ALIGN1 =
188 return &blanks[sizeof(blanks) - i - 1];
190 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
191 #define DEBUG_CLEAN 1
195 static void debug_print_strings(const char *prefix, char **vv)
197 fprintf(stderr, "%s:\n", prefix);
199 fprintf(stderr, " '%s'\n", *vv++);
202 #define debug_print_strings(prefix, vv) ((void)0)
206 * Leak hunting. Use hush_leaktool.sh for post-processing.
208 #ifdef FOR_HUSH_LEAKTOOL
209 static void *xxmalloc(int lineno, size_t size)
211 void *ptr = xmalloc((size + 0xff) & ~0xff);
212 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
215 static void *xxrealloc(int lineno, void *ptr, size_t size)
217 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
218 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
221 static char *xxstrdup(int lineno, const char *str)
223 char *ptr = xstrdup(str);
224 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
227 static void xxfree(void *ptr)
229 fdprintf(2, "free %p\n", ptr);
232 #define xmalloc(s) xxmalloc(__LINE__, s)
233 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
234 #define xstrdup(s) xxstrdup(__LINE__, s)
235 #define free(p) xxfree(p)
239 #define ERR_PTR ((void*)(long)1)
241 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
243 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
245 #define SPECIAL_VAR_SYMBOL 3
247 typedef enum redir_type {
249 REDIRECT_OVERWRITE = 2,
255 /* The descrip member of this structure is only used to make
256 * debugging output pretty */
257 static const struct {
259 signed char default_fd;
263 { O_RDONLY, 0, "<" },
264 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
265 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
266 { O_RDONLY, -1, "<<" },
270 typedef enum pipe_style {
277 typedef enum reserved_style {
286 #if ENABLE_HUSH_LOOPS
293 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
298 /* two pseudo-keywords support contrived "case" syntax: */
299 RES_MATCH , /* "word)" */
300 RES_CASEI , /* "this command is inside CASE" */
307 typedef struct o_string {
309 int length; /* position where data is appended */
311 /* Protect newly added chars against globbing
312 * (by prepending \ to *, ?, [, \) */
316 smallint has_empty_slot;
317 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
320 MAYBE_ASSIGNMENT = 0,
321 DEFINITELY_ASSIGNMENT = 1,
323 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
325 /* Used for initialization: o_string foo = NULL_O_STRING; */
326 #define NULL_O_STRING { NULL }
328 /* I can almost use ordinary FILE*. Is open_memstream() universally
329 * available? Where is it documented? */
330 typedef struct in_str {
332 /* eof_flag=1: last char in ->p is really an EOF */
333 char eof_flag; /* meaningless if ->p == NULL */
335 #if ENABLE_HUSH_INTERACTIVE
337 smallint promptmode; /* 0: PS1, 1: PS2 */
340 int (*get) (struct in_str *);
341 int (*peek) (struct in_str *);
343 #define i_getch(input) ((input)->get(input))
344 #define i_peek(input) ((input)->peek(input))
346 struct redir_struct {
347 struct redir_struct *next;
348 char *rd_filename; /* filename */
349 int fd; /* file descriptor being redirected */
350 int dup; /* -1, or file descriptor being duplicated */
351 smallint /*enum redir_type*/ rd_type;
355 pid_t pid; /* 0 if exited */
356 int assignment_cnt; /* how many argv[i] are assignments? */
357 smallint is_stopped; /* is the command currently running? */
358 smallint grp_type; /* GRP_xxx */
359 struct pipe *group; /* if non-NULL, this "command" is { list },
360 * ( list ), or a compound statement */
362 char *group_as_string;
364 char **argv; /* command name and arguments */
365 struct redir_struct *redirects; /* I/O redirections */
367 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
368 * and on execution these are substituted with their values.
369 * Substitution can make _several_ words out of one argv[n]!
370 * Example: argv[0]=='.^C*^C.' here: echo .$*.
371 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
374 #define GRP_SUBSHELL 1
375 #if ENABLE_HUSH_FUNCTIONS
376 #define GRP_FUNCTION 2
381 int num_cmds; /* total number of commands in job */
382 int alive_cmds; /* number of commands running (not exited) */
383 int stopped_cmds; /* number of commands alive, but stopped */
385 int jobid; /* job number */
386 pid_t pgrp; /* process group ID for the job */
387 char *cmdtext; /* name of job */
389 struct command *cmds; /* array of commands in pipe */
390 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
391 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
392 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
395 /* This holds pointers to the various results of parsing */
396 struct parse_context {
397 /* linked list of pipes */
398 struct pipe *list_head;
399 /* last pipe (being constructed right now) */
401 /* last command in pipe (being constructed right now) */
402 struct command *command;
403 /* last redirect in command->redirects list */
404 struct redir_struct *pending_redirect;
410 smallint ctx_inverted; /* "! cmd | cmd" */
412 smallint ctx_dsemicolon; /* ";;" seen */
414 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
416 /* group we are enclosed in:
417 * example: "if pipe1; pipe2; then pipe3; fi"
418 * when we see "if" or "then", we malloc and copy current context,
419 * and make ->stack point to it. then we parse pipeN.
420 * when closing "then" / fi" / whatever is found,
421 * we move list_head into ->stack->command->group,
422 * copy ->stack into current context, and delete ->stack.
423 * (parsing of { list } and ( list ) doesn't use this method)
425 struct parse_context *stack;
429 /* On program start, environ points to initial environment.
430 * putenv adds new pointers into it, unsetenv removes them.
431 * Neither of these (de)allocates the strings.
432 * setenv allocates new strings in malloc space and does putenv,
433 * and thus setenv is unusable (leaky) for shell's purposes */
434 #define setenv(...) setenv_is_leaky_dont_use()
436 struct variable *next;
437 char *varstr; /* points to "name=" portion */
438 int max_len; /* if > 0, name is part of initial env; else name is malloced */
439 smallint flg_export; /* putenv should be done on this var */
440 smallint flg_read_only;
449 /* "Globals" within this file */
450 /* Sorted roughly by size (smaller offsets == smaller code) */
452 #if ENABLE_HUSH_INTERACTIVE
453 /* 'interactive_fd' is a fd# open to ctty, if we have one
454 * _AND_ if we decided to act interactively */
458 #define G_interactive_fd (G.interactive_fd)
460 #define G_interactive_fd 0
462 #if ENABLE_FEATURE_EDITING
463 line_input_t *line_input_state;
469 pid_t saved_tty_pgrp;
471 struct pipe *job_list;
472 struct pipe *toplevel_list;
473 //// smallint ctrl_z_flag;
475 smallint flag_SIGINT;
476 #if ENABLE_HUSH_LOOPS
477 smallint flag_break_continue;
480 /* These four support $?, $#, and $1 */
481 smalluint last_return_code;
482 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
483 smalluint global_args_malloced;
484 /* how many non-NULL argv's we have. NB: $# + 1 */
488 char *argv0_for_re_execing;
489 char **argv_from_re_execing;
491 #if ENABLE_HUSH_LOOPS
492 unsigned depth_break_continue;
493 unsigned depth_of_loop;
497 struct variable *top_var; /* = &G.shell_ver (set in main()) */
498 struct variable shell_ver;
499 /* Signal and trap handling */
500 // unsigned count_SIGCHLD;
501 // unsigned handled_SIGCHLD;
502 /* which signals have non-DFL handler (even with no traps set)? */
503 unsigned non_DFL_mask;
504 char **traps; /* char *traps[NSIG] */
505 sigset_t blocked_set;
506 sigset_t inherited_set;
507 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
508 #if ENABLE_FEATURE_SH_STANDALONE
509 struct nofork_save_area nofork_save;
512 sigjmp_buf toplevel_jb;
515 #define G (*ptr_to_globals)
516 /* Not #defining name to G.name - this quickly gets unwieldy
517 * (too many defines). Also, I actually prefer to see when a variable
518 * is global, thus "G." prefix is a useful hint */
519 #define INIT_G() do { \
520 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
524 /* Function prototypes for builtins */
525 static int builtin_cd(char **argv);
526 static int builtin_echo(char **argv);
527 static int builtin_eval(char **argv);
528 static int builtin_exec(char **argv);
529 static int builtin_exit(char **argv);
530 static int builtin_export(char **argv);
532 static int builtin_fg_bg(char **argv);
533 static int builtin_jobs(char **argv);
536 static int builtin_help(char **argv);
538 static int builtin_pwd(char **argv);
539 static int builtin_read(char **argv);
540 static int builtin_test(char **argv);
541 static int builtin_trap(char **argv);
542 static int builtin_true(char **argv);
543 static int builtin_set(char **argv);
544 static int builtin_shift(char **argv);
545 static int builtin_source(char **argv);
546 static int builtin_umask(char **argv);
547 static int builtin_unset(char **argv);
548 static int builtin_wait(char **argv);
549 #if ENABLE_HUSH_LOOPS
550 static int builtin_break(char **argv);
551 static int builtin_continue(char **argv);
554 /* Table of built-in functions. They can be forked or not, depending on
555 * context: within pipes, they fork. As simple commands, they do not.
556 * When used in non-forking context, they can change global variables
557 * in the parent shell process. If forked, of course they cannot.
558 * For example, 'unset foo | whatever' will parse and run, but foo will
559 * still be set at the end. */
560 struct built_in_command {
562 int (*function)(char **argv);
565 #define BLTIN(cmd, func, help) { cmd, func, help }
567 #define BLTIN(cmd, func, help) { cmd, func }
571 /* For now, echo and test are unconditionally enabled.
572 * Maybe make it configurable? */
573 static const struct built_in_command bltins[] = {
574 BLTIN("." , builtin_source , "Run commands in a file"),
575 BLTIN(":" , builtin_true , "No-op"),
576 BLTIN("[" , builtin_test , "Test condition"),
578 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
580 #if ENABLE_HUSH_LOOPS
581 BLTIN("break" , builtin_break , "Exit from a loop"),
583 BLTIN("cd" , builtin_cd , "Change directory"),
584 #if ENABLE_HUSH_LOOPS
585 BLTIN("continue", builtin_continue, "Start new loop iteration"),
587 BLTIN("echo" , builtin_echo , "Write to stdout"),
588 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
589 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
590 BLTIN("exit" , builtin_exit , "Exit"),
591 BLTIN("export" , builtin_export , "Set environment variable"),
593 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
596 BLTIN("help" , builtin_help , "List shell built-in commands"),
599 BLTIN("jobs" , builtin_jobs , "List active jobs"),
601 BLTIN("pwd" , builtin_pwd , "Print current directory"),
602 BLTIN("read" , builtin_read , "Input environment variable"),
603 // BLTIN("return" , builtin_return , "Return from a function"),
604 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
605 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
606 BLTIN("test" , builtin_test , "Test condition"),
607 BLTIN("trap" , builtin_trap , "Trap signals"),
608 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
609 BLTIN("umask" , builtin_umask , "Set file creation mask"),
610 BLTIN("unset" , builtin_unset , "Unset environment variable"),
611 BLTIN("wait" , builtin_wait , "Wait for process"),
615 static void maybe_die(const char *notice, const char *msg)
617 /* Was using fancy stuff:
618 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
619 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
620 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
621 #if ENABLE_HUSH_INTERACTIVE
622 if (G_interactive_fd)
625 fp(msg ? "%s: %s" : notice, notice, msg);
628 #define syntax(msg) maybe_die("syntax error", msg);
630 /* Debug -- trick gcc to expand __LINE__ and convert to string */
631 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
632 #define _syntax(msg, line) __syntax(msg, line)
633 #define syntax(msg) _syntax(msg, __LINE__)
637 static int glob_needed(const char *s)
642 if (*s == '*' || *s == '[' || *s == '?')
649 static int is_assignment(const char *s)
651 if (!s || !(isalpha(*s) || *s == '_'))
654 while (isalnum(*s) || *s == '_')
659 /* Replace each \x with x in place, return ptr past NUL. */
660 static char *unbackslash(char *src)
666 if ((*dst++ = *src++) == '\0')
672 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
693 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
694 v[count1 + count2] = NULL;
697 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
701 static char **add_string_to_strings(char **strings, char *add)
706 return add_strings_to_strings(strings, v, /*dup:*/ 0);
709 static void putenv_all(char **strings)
714 debug_printf_env("putenv '%s'\n", *strings);
719 static char **putenv_all_and_save_old(char **strings)
729 eq = strchr(*strings, '=');
732 v = getenv(*strings);
735 /* v points to VAL in VAR=VAL, go back to VAR */
736 v -= (eq - *strings) + 1;
737 old = add_string_to_strings(old, v);
746 static void free_strings_and_unsetenv(char **strings, int unset)
756 debug_printf_env("unsetenv '%s'\n", *v);
764 static void free_strings(char **strings)
766 free_strings_and_unsetenv(strings, 0);
770 /* Basic theory of signal handling in shell
771 * ========================================
772 * This does not describe what hush does, rather, it is current understanding
773 * what it _should_ do. If it doesn't, it's a bug.
774 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
776 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
777 * is finished or backgrounded. It is the same in interactive and
778 * non-interactive shells, and is the same regardless of whether
779 * a user trap handler is installed or a shell special one is in effect.
780 * ^C or ^Z from keyboard seem to execute "at once" because it usually
781 * backgrounds (i.e. stops) or kills all members of currently running
784 * Wait builtin in interruptible by signals for which user trap is set
785 * or by SIGINT in interactive shell.
787 * Trap handlers will execute even within trap handlers. (right?)
789 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
791 * If job control is off, backgrounded commands ("cmd &")
792 * have SIGINT, SIGQUIT set to SIG_IGN.
794 * Commands run in command substitution ("`cmd`")
795 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
797 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
798 * by the shell from its parent.
800 * Siganls which differ from SIG_DFL action
801 * (note: child (i.e., [v]forked) shell is not an interactive shell):
804 * SIGTERM (interactive): ignore
805 * SIGHUP (interactive):
806 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
807 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
808 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
809 * that all pipe members are stopped) (right?)
810 * SIGINT (interactive): wait for last pipe, ignore the rest
811 * of the command line, show prompt. NB: ^C does not send SIGINT
812 * to interactive shell while shell is waiting for a pipe,
813 * since shell is bg'ed (is not in foreground process group).
814 * (check/expand this)
815 * Example 1: this waits 5 sec, but does not execute ls:
816 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
817 * Example 2: this does not wait and does not execute ls:
818 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
819 * Example 3: this does not wait 5 sec, but executes ls:
820 * "sleep 5; ls -l" + press ^C
822 * (What happens to signals which are IGN on shell start?)
823 * (What happens with signal mask on shell start?)
825 * Implementation in hush
826 * ======================
827 * We use in-kernel pending signal mask to determine which signals were sent.
828 * We block all signals which we don't want to take action immediately,
829 * i.e. we block all signals which need to have special handling as described
830 * above, and all signals which have traps set.
831 * After each pipe execution, we extract any pending signals via sigtimedwait()
834 * unsigned non_DFL_mask: a mask of such "special" signals
835 * sigset_t blocked_set: current blocked signal set
838 * clear bit in blocked_set unless it is also in non_DFL_mask
839 * "trap 'cmd' SIGxxx":
840 * set bit in blocked_set (even if 'cmd' is '')
841 * after [v]fork, if we plan to be a shell:
842 * nothing for {} child shell (say, "true | { true; true; } | true")
843 * unset all traps if () shell. [TODO]
844 * after [v]fork, if we plan to exec:
845 * POSIX says pending signal mask is cleared in child - no need to clear it.
846 * Restore blocked signal set to one inherited by shell just prior to exec.
848 * Note: as a result, we do not use signal handlers much. The only uses
849 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
850 * and to restore tty pgrp on signal-induced exit.
853 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
855 // G.count_SIGCHLD++;
858 static int check_and_run_traps(int sig)
860 static const struct timespec zero_timespec = { 0, 0 };
861 smalluint save_rcode;
867 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
872 if (G.traps && G.traps[sig]) {
873 if (G.traps[sig][0]) {
874 /* We have user-defined handler */
875 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
876 save_rcode = G.last_return_code;
879 G.last_return_code = save_rcode;
880 } /* else: "" trap, ignoring signal */
883 /* not a trap: special action */
886 // G.count_SIGCHLD++;
895 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
903 /* Restores tty foreground process group, and exits.
904 * May be called as signal handler for fatal signal
905 * (will faithfully resend signal to itself, producing correct exit state)
906 * or called directly with -EXITCODE.
907 * We also call it if xfunc is exiting. */
908 static void sigexit(int sig) NORETURN;
909 static void sigexit(int sig)
911 /* Disable all signals: job control, SIGPIPE, etc. */
912 sigprocmask_allsigs(SIG_BLOCK);
914 /* Careful: we can end up here after [v]fork. Do not restore
915 * tty pgrp then, only top-level shell process does that */
916 if (G_interactive_fd && getpid() == G.root_pid)
917 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
919 /* Not a signal, just exit */
923 kill_myself_with_sig(sig); /* does not return */
927 /* Restores tty foreground process group, and exits. */
928 static void hush_exit(int exitcode) NORETURN;
929 static void hush_exit(int exitcode)
931 if (G.traps && G.traps[0] && G.traps[0][0]) {
932 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
933 //TODO: do we need to prevent recursion?
939 fflush(NULL); /* flush all streams */
940 sigexit(- (exitcode & 0xff));
947 static const char *set_cwd(void)
949 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
950 * we must not try to free(bb_msg_unknown) */
951 if (G.cwd == bb_msg_unknown)
953 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
955 G.cwd = bb_msg_unknown;
960 /* Get/check local shell variables */
961 static struct variable *get_local_var(const char *name)
963 struct variable *cur;
969 for (cur = G.top_var; cur; cur = cur->next) {
970 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
976 static const char *get_local_var_value(const char *src)
978 struct variable *var = get_local_var(src);
980 return strchr(var->varstr, '=') + 1;
984 /* str holds "NAME=VAL" and is expected to be malloced.
985 * We take ownership of it.
989 * -1: if NAME is set, leave export status alone
990 * if NAME is not set, do not export
991 * flg_read_only is set only when we handle -R var=val
994 #define set_local_var(str, flg_export, flg_read_only) \
995 set_local_var(str, flg_export)
997 static int set_local_var(char *str, int flg_export, int flg_read_only)
999 struct variable *cur;
1003 value = strchr(str, '=');
1004 if (!value) { /* not expected to ever happen? */
1009 name_len = value - str + 1; /* including '=' */
1010 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1012 if (strncmp(cur->varstr, str, name_len) != 0) {
1014 /* Bail out. Note that now cur points
1015 * to last var in linked list */
1021 /* We found an existing var with this name */
1023 if (cur->flg_read_only) {
1027 bb_error_msg("%s: readonly variable", str);
1031 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1032 unsetenv(str); /* just in case */
1034 if (strcmp(cur->varstr, str) == 0) {
1039 if (cur->max_len >= strlen(str)) {
1040 /* This one is from startup env, reuse space */
1041 strcpy(cur->varstr, str);
1044 /* max_len == 0 signifies "malloced" var, which we can
1045 * (and has to) free */
1049 goto set_str_and_exp;
1052 /* Not found - create next variable struct */
1053 cur->next = xzalloc(sizeof(*cur));
1059 cur->flg_read_only = flg_read_only;
1062 if (flg_export == 1)
1063 cur->flg_export = 1;
1064 if (cur->flg_export) {
1065 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1066 return putenv(cur->varstr);
1071 static int unset_local_var(const char *name)
1073 struct variable *cur;
1074 struct variable *prev = prev; /* for gcc */
1078 return EXIT_SUCCESS;
1079 name_len = strlen(name);
1082 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1083 if (cur->flg_read_only) {
1084 bb_error_msg("%s: readonly variable", name);
1085 return EXIT_FAILURE;
1087 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1088 * is ro, and we cannot reach this code on the 1st pass */
1089 prev->next = cur->next;
1090 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1091 bb_unsetenv(cur->varstr);
1095 return EXIT_SUCCESS;
1100 return EXIT_SUCCESS;
1103 #if ENABLE_SH_MATH_SUPPORT
1104 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1105 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1106 static char *endofname(const char *name)
1114 if (!is_in_name(*p))
1120 static void arith_set_local_var(const char *name, const char *val, int flags)
1122 /* arith code doesnt malloc space, so do it for it */
1123 char *var = xasprintf("%s=%s", name, val);
1124 set_local_var(var, flags, 0);
1132 static int static_get(struct in_str *i)
1141 static int static_peek(struct in_str *i)
1146 #if ENABLE_HUSH_INTERACTIVE
1148 static void cmdedit_set_initial_prompt(void)
1150 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1151 G.PS1 = getenv("PS1");
1158 static const char* setup_prompt_string(int promptmode)
1160 const char *prompt_str;
1161 debug_printf("setup_prompt_string %d ", promptmode);
1162 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1163 /* Set up the prompt */
1164 if (promptmode == 0) { /* PS1 */
1166 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1171 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1172 debug_printf("result '%s'\n", prompt_str);
1176 static void get_user_input(struct in_str *i)
1179 const char *prompt_str;
1181 prompt_str = setup_prompt_string(i->promptmode);
1182 #if ENABLE_FEATURE_EDITING
1183 /* Enable command line editing only while a command line
1184 * is actually being read */
1187 /* buglet: SIGINT will not make new prompt to appear _at once_,
1188 * only after <Enter>. (^C will work) */
1189 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1190 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1191 check_and_run_traps(0);
1192 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1193 i->eof_flag = (r < 0);
1194 if (i->eof_flag) { /* EOF/error detected */
1195 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1196 G.user_input_buf[1] = '\0';
1201 fputs(prompt_str, stdout);
1203 G.user_input_buf[0] = r = fgetc(i->file);
1204 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1205 //do we need check_and_run_traps(0)? (maybe only if stdin)
1206 } while (G.flag_SIGINT);
1207 i->eof_flag = (r == EOF);
1209 i->p = G.user_input_buf;
1212 #endif /* INTERACTIVE */
1214 /* This is the magic location that prints prompts
1215 * and gets data back from the user */
1216 static int file_get(struct in_str *i)
1220 /* If there is data waiting, eat it up */
1221 if (i->p && *i->p) {
1222 #if ENABLE_HUSH_INTERACTIVE
1226 if (i->eof_flag && !*i->p)
1229 /* need to double check i->file because we might be doing something
1230 * more complicated by now, like sourcing or substituting. */
1231 #if ENABLE_HUSH_INTERACTIVE
1232 if (G_interactive_fd && i->promptme && i->file == stdin) {
1235 } while (!*i->p); /* need non-empty line */
1236 i->promptmode = 1; /* PS2 */
1241 ch = fgetc(i->file);
1243 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1244 #if ENABLE_HUSH_INTERACTIVE
1251 /* All the callers guarantee this routine will never be
1252 * used right after a newline, so prompting is not needed.
1254 static int file_peek(struct in_str *i)
1257 if (i->p && *i->p) {
1258 if (i->eof_flag && !i->p[1])
1262 ch = fgetc(i->file);
1263 i->eof_flag = (ch == EOF);
1264 i->peek_buf[0] = ch;
1265 i->peek_buf[1] = '\0';
1267 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1271 static void setup_file_in_str(struct in_str *i, FILE *f)
1273 i->peek = file_peek;
1275 #if ENABLE_HUSH_INTERACTIVE
1277 i->promptmode = 0; /* PS1 */
1283 static void setup_string_in_str(struct in_str *i, const char *s)
1285 i->peek = static_peek;
1286 i->get = static_get;
1287 #if ENABLE_HUSH_INTERACTIVE
1289 i->promptmode = 0; /* PS1 */
1299 #define B_CHUNK (32 * sizeof(char*))
1301 static void o_reset(o_string *o)
1309 static void o_free(o_string *o)
1312 memset(o, 0, sizeof(*o));
1315 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1320 static void o_grow_by(o_string *o, int len)
1322 if (o->length + len > o->maxlen) {
1323 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1324 o->data = xrealloc(o->data, 1 + o->maxlen);
1328 static void o_addchr(o_string *o, int ch)
1330 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1332 o->data[o->length] = ch;
1334 o->data[o->length] = '\0';
1337 static void o_addblock(o_string *o, const char *str, int len)
1340 memcpy(&o->data[o->length], str, len);
1342 o->data[o->length] = '\0';
1346 static void o_addstr(o_string *o, const char *str)
1348 o_addblock(o, str, strlen(str));
1352 static void o_addstr_with_NUL(o_string *o, const char *str)
1354 o_addblock(o, str, strlen(str) + 1);
1357 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1362 && (*str != '*' && *str != '?' && *str != '[')
1370 /* My analysis of quoting semantics tells me that state information
1371 * is associated with a destination, not a source.
1373 static void o_addqchr(o_string *o, int ch)
1376 char *found = strchr("*?[\\", ch);
1381 o->data[o->length] = '\\';
1384 o->data[o->length] = ch;
1386 o->data[o->length] = '\0';
1389 static void o_addQchr(o_string *o, int ch)
1392 if (o->o_escape && strchr("*?[\\", ch)) {
1394 o->data[o->length] = '\\';
1398 o->data[o->length] = ch;
1400 o->data[o->length] = '\0';
1403 static void o_addQstr(o_string *o, const char *str, int len)
1406 o_addblock(o, str, len);
1412 int ordinary_cnt = strcspn(str, "*?[\\");
1413 if (ordinary_cnt > len) /* paranoia */
1415 o_addblock(o, str, ordinary_cnt);
1416 if (ordinary_cnt == len)
1418 str += ordinary_cnt;
1419 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1423 if (ch) { /* it is necessarily one of "*?[\\" */
1425 o->data[o->length] = '\\';
1429 o->data[o->length] = ch;
1431 o->data[o->length] = '\0';
1435 /* A special kind of o_string for $VAR and `cmd` expansion.
1436 * It contains char* list[] at the beginning, which is grown in 16 element
1437 * increments. Actual string data starts at the next multiple of 16 * (char*).
1438 * list[i] contains an INDEX (int!) into this string data.
1439 * It means that if list[] needs to grow, data needs to be moved higher up
1440 * but list[i]'s need not be modified.
1441 * NB: remembering how many list[i]'s you have there is crucial.
1442 * o_finalize_list() operation post-processes this structure - calculates
1443 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1445 #if DEBUG_EXPAND || DEBUG_GLOB
1446 static void debug_print_list(const char *prefix, o_string *o, int n)
1448 char **list = (char**)o->data;
1449 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1451 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1452 prefix, list, n, string_start, o->length, o->maxlen);
1454 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1455 o->data + (int)list[i] + string_start,
1456 o->data + (int)list[i] + string_start);
1460 const char *p = o->data + (int)list[n - 1] + string_start;
1461 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1465 #define debug_print_list(prefix, o, n) ((void)0)
1468 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1469 * in list[n] so that it points past last stored byte so far.
1470 * It returns n+1. */
1471 static int o_save_ptr_helper(o_string *o, int n)
1473 char **list = (char**)o->data;
1477 if (!o->has_empty_slot) {
1478 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1479 string_len = o->length - string_start;
1480 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1481 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1482 /* list[n] points to string_start, make space for 16 more pointers */
1483 o->maxlen += 0x10 * sizeof(list[0]);
1484 o->data = xrealloc(o->data, o->maxlen + 1);
1485 list = (char**)o->data;
1486 memmove(list + n + 0x10, list + n, string_len);
1487 o->length += 0x10 * sizeof(list[0]);
1489 debug_printf_list("list[%d]=%d string_start=%d\n",
1490 n, string_len, string_start);
1493 /* We have empty slot at list[n], reuse without growth */
1494 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1495 string_len = o->length - string_start;
1496 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1497 n, string_len, string_start);
1498 o->has_empty_slot = 0;
1500 list[n] = (char*)(ptrdiff_t)string_len;
1504 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1505 static int o_get_last_ptr(o_string *o, int n)
1507 char **list = (char**)o->data;
1508 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1510 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1513 /* o_glob performs globbing on last list[], saving each result
1514 * as a new list[]. */
1515 static int o_glob(o_string *o, int n)
1521 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1523 return o_save_ptr_helper(o, n);
1524 pattern = o->data + o_get_last_ptr(o, n);
1525 debug_printf_glob("glob pattern '%s'\n", pattern);
1526 if (!glob_needed(pattern)) {
1528 o->length = unbackslash(pattern) - o->data;
1529 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1530 return o_save_ptr_helper(o, n);
1533 memset(&globdata, 0, sizeof(globdata));
1534 gr = glob(pattern, 0, NULL, &globdata);
1535 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1536 if (gr == GLOB_NOSPACE)
1537 bb_error_msg_and_die("out of memory during glob");
1538 if (gr == GLOB_NOMATCH) {
1539 globfree(&globdata);
1542 if (gr != 0) { /* GLOB_ABORTED ? */
1543 //TODO: testcase for bad glob pattern behavior
1544 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1546 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1547 char **argv = globdata.gl_pathv;
1548 o->length = pattern - o->data; /* "forget" pattern */
1550 o_addstr_with_NUL(o, *argv);
1551 n = o_save_ptr_helper(o, n);
1557 globfree(&globdata);
1559 debug_print_list("o_glob returning", o, n);
1563 /* If o->o_glob == 1, glob the string so far remembered.
1564 * Otherwise, just finish current list[] and start new */
1565 static int o_save_ptr(o_string *o, int n)
1567 if (o->o_glob) { /* if globbing is requested */
1568 /* If o->has_empty_slot, list[n] was already globbed
1569 * (if it was requested back then when it was filled)
1570 * so don't do that again! */
1571 if (!o->has_empty_slot)
1572 return o_glob(o, n); /* o_save_ptr_helper is inside */
1574 return o_save_ptr_helper(o, n);
1577 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1578 static char **o_finalize_list(o_string *o, int n)
1583 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1585 debug_print_list("finalized", o, n);
1586 debug_printf_expand("finalized n:%d\n", n);
1587 list = (char**)o->data;
1588 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1592 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1598 /* Expansion can recurse */
1599 #if ENABLE_HUSH_TICK
1600 static int process_command_subs(o_string *dest, const char *s);
1602 static char *expand_string_to_string(const char *str);
1604 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1605 parse_stream_dquoted(dest, input, dquote_end)
1607 static int parse_stream_dquoted(o_string *as_string,
1609 struct in_str *input,
1612 /* expand_strvec_to_strvec() takes a list of strings, expands
1613 * all variable references within and returns a pointer to
1614 * a list of expanded strings, possibly with larger number
1615 * of strings. (Think VAR="a b"; echo $VAR).
1616 * This new list is allocated as a single malloc block.
1617 * NULL-terminated list of char* pointers is at the beginning of it,
1618 * followed by strings themself.
1619 * Caller can deallocate entire list by single free(list). */
1621 /* Store given string, finalizing the word and starting new one whenever
1622 * we encounter IFS char(s). This is used for expanding variable values.
1623 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1624 static int expand_on_ifs(o_string *output, int n, const char *str)
1627 int word_len = strcspn(str, G.ifs);
1629 if (output->o_escape || !output->o_glob)
1630 o_addQstr(output, str, word_len);
1631 else /* protect backslashes against globbing up :) */
1632 o_addblock_duplicate_backslash(output, str, word_len);
1635 if (!*str) /* EOL - do not finalize word */
1637 o_addchr(output, '\0');
1638 debug_print_list("expand_on_ifs", output, n);
1639 n = o_save_ptr(output, n);
1640 str += strspn(str, G.ifs); /* skip ifs chars */
1642 debug_print_list("expand_on_ifs[1]", output, n);
1646 /* Expand all variable references in given string, adding words to list[]
1647 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1648 * to be filled). This routine is extremely tricky: has to deal with
1649 * variables/parameters with whitespace, $* and $@, and constructs like
1650 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1651 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1653 /* or_mask is either 0 (normal case) or 0x80
1654 * (expansion of right-hand side of assignment == 1-element expand.
1655 * It will also do no globbing, and thus we must not backslash-quote!) */
1657 char first_ch, ored_ch;
1664 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1665 debug_print_list("expand_vars_to_list", output, n);
1666 n = o_save_ptr(output, n);
1667 debug_print_list("expand_vars_to_list[0]", output, n);
1669 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1670 #if ENABLE_HUSH_TICK
1671 o_string subst_result = NULL_O_STRING;
1673 #if ENABLE_SH_MATH_SUPPORT
1674 char arith_buf[sizeof(arith_t)*3 + 2];
1676 o_addblock(output, arg, p - arg);
1677 debug_print_list("expand_vars_to_list[1]", output, n);
1679 p = strchr(p, SPECIAL_VAR_SYMBOL);
1681 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1682 /* "$@" is special. Even if quoted, it can still
1683 * expand to nothing (not even an empty string) */
1684 if ((first_ch & 0x7f) != '@')
1685 ored_ch |= first_ch;
1688 switch (first_ch & 0x7f) {
1689 /* Highest bit in first_ch indicates that var is double-quoted */
1691 val = utoa(G.root_pid);
1693 case '!': /* bg pid */
1694 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1696 case '?': /* exitcode */
1697 val = utoa(G.last_return_code);
1699 case '#': /* argc */
1700 if (arg[1] != SPECIAL_VAR_SYMBOL)
1701 /* actually, it's a ${#var} */
1703 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1708 if (!G.global_argv[i])
1710 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1711 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1712 smallint sv = output->o_escape;
1713 /* unquoted var's contents should be globbed, so don't escape */
1714 output->o_escape = 0;
1715 while (G.global_argv[i]) {
1716 n = expand_on_ifs(output, n, G.global_argv[i]);
1717 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1718 if (G.global_argv[i++][0] && G.global_argv[i]) {
1719 /* this argv[] is not empty and not last:
1720 * put terminating NUL, start new word */
1721 o_addchr(output, '\0');
1722 debug_print_list("expand_vars_to_list[2]", output, n);
1723 n = o_save_ptr(output, n);
1724 debug_print_list("expand_vars_to_list[3]", output, n);
1727 output->o_escape = sv;
1729 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1730 * and in this case should treat it like '$*' - see 'else...' below */
1731 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1733 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1734 if (++i >= G.global_argc)
1736 o_addchr(output, '\0');
1737 debug_print_list("expand_vars_to_list[4]", output, n);
1738 n = o_save_ptr(output, n);
1740 } else { /* quoted $*: add as one word */
1742 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1743 if (!G.global_argv[++i])
1746 o_addchr(output, G.ifs[0]);
1750 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1751 /* "Empty variable", used to make "" etc to not disappear */
1755 #if ENABLE_HUSH_TICK
1756 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1759 //TODO: can we just stuff it into "output" directly?
1760 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1761 process_command_subs(&subst_result, arg);
1762 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1763 val = subst_result.data;
1766 #if ENABLE_SH_MATH_SUPPORT
1767 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1768 arith_eval_hooks_t hooks;
1773 arg++; /* skip '+' */
1774 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1775 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1777 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1780 unsigned char c = *exp_str++;
1787 if (strchr(" \t+-*/%_", c) != NULL)
1789 c |= 0x20; /* tolower */
1790 if (c >= 'a' && c <= 'z')
1794 /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
1796 struct in_str input;
1797 o_string dest = NULL_O_STRING;
1799 setup_string_in_str(&input, arg);
1800 parse_stream_dquoted(NULL, &dest, &input, EOF);
1801 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1802 exp_str = expand_string_to_string(dest.data);
1803 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1807 hooks.lookupvar = get_local_var_value;
1808 hooks.setvar = arith_set_local_var;
1809 hooks.endofname = endofname;
1810 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1815 case -3: maybe_die("arith", "exponent less than 0"); break;
1816 case -2: maybe_die("arith", "divide by zero"); break;
1817 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1818 default: maybe_die("arith", "syntax error"); break;
1821 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1822 sprintf(arith_buf, arith_t_fmt, res);
1827 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1829 bool exp_len = false;
1830 bool exp_null = false;
1832 char exp_save = exp_save; /* for compiler */
1833 char exp_op = exp_op; /* for compiler */
1834 char *exp_word = exp_word; /* for compiler */
1838 arg[0] = first_ch & 0x7f;
1840 /* prepare for expansions */
1841 if (var[0] == '#') {
1842 /* handle length expansion ${#var} */
1846 /* maybe handle parameter expansion */
1847 exp_off = strcspn(var, ":-=+?");
1851 exp_save = var[exp_off];
1852 exp_null = exp_save == ':';
1853 exp_word = var + exp_off;
1854 if (exp_null) ++exp_word;
1855 exp_op = *exp_word++;
1856 var[exp_off] = '\0';
1860 /* lookup the variable in question */
1861 if (isdigit(var[0])) {
1862 /* handle_dollar() should have vetted var for us */
1864 if (i < G.global_argc)
1865 val = G.global_argv[i];
1866 /* else val remains NULL: $N with too big N */
1868 val = get_local_var_value(var);
1870 /* handle any expansions */
1872 debug_printf_expand("expand: length of '%s' = ", val);
1873 val = utoa(val ? strlen(val) : 0);
1874 debug_printf_expand("%s\n", val);
1875 } else if (exp_off) {
1876 /* we need to do an expansion */
1877 int exp_test = (!val || (exp_null && !val[0]));
1879 exp_test = !exp_test;
1880 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1881 exp_null ? "true" : "false", exp_test);
1884 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1888 if (exp_op == '=') {
1889 if (isdigit(var[0]) || var[0] == '#') {
1890 maybe_die(var, "special vars cannot assign in this way");
1893 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1894 sprintf(new_var, "%s=%s", var, val);
1895 set_local_var(new_var, -1, 0);
1899 var[exp_off] = exp_save;
1903 #if ENABLE_HUSH_TICK
1906 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1907 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1909 /* unquoted var's contents should be globbed, so don't escape */
1910 smallint sv = output->o_escape;
1911 output->o_escape = 0;
1912 n = expand_on_ifs(output, n, val);
1914 output->o_escape = sv;
1916 } else { /* quoted $VAR, val will be appended below */
1917 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1920 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1922 o_addQstr(output, val, strlen(val));
1924 /* Do the check to avoid writing to a const string */
1925 if (*p != SPECIAL_VAR_SYMBOL)
1926 *p = SPECIAL_VAR_SYMBOL;
1928 #if ENABLE_HUSH_TICK
1929 o_free(&subst_result);
1932 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1935 debug_print_list("expand_vars_to_list[a]", output, n);
1936 /* this part is literal, and it was already pre-quoted
1937 * if needed (much earlier), do not use o_addQstr here! */
1938 o_addstr_with_NUL(output, arg);
1939 debug_print_list("expand_vars_to_list[b]", output, n);
1940 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1941 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1944 /* allow to reuse list[n] later without re-growth */
1945 output->has_empty_slot = 1;
1947 o_addchr(output, '\0');
1952 static char **expand_variables(char **argv, int or_mask)
1957 o_string output = NULL_O_STRING;
1959 if (or_mask & 0x100) {
1960 output.o_escape = 1; /* protect against globbing for "$var" */
1961 /* (unquoted $var will temporarily switch it off) */
1968 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
1971 debug_print_list("expand_variables", &output, n);
1973 /* output.data (malloced in one block) gets returned in "list" */
1974 list = o_finalize_list(&output, n);
1975 debug_print_strings("expand_variables[1]", list);
1979 static char **expand_strvec_to_strvec(char **argv)
1981 return expand_variables(argv, 0x100);
1984 /* Used for expansion of right hand of assignments */
1985 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
1987 static char *expand_string_to_string(const char *str)
1989 char *argv[2], **list;
1991 argv[0] = (char*)str;
1993 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
1995 if (!list[0] || list[1])
1996 bb_error_msg_and_die("BUG in varexp2");
1997 /* actually, just move string 2*sizeof(char*) bytes back */
1998 overlapping_strcpy((char*)list, list[0]);
1999 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2003 /* Used for "eval" builtin */
2004 static char* expand_strvec_to_string(char **argv)
2008 list = expand_variables(argv, 0x80);
2009 /* Convert all NULs to spaces */
2014 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2015 bb_error_msg_and_die("BUG in varexp3");
2016 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2020 overlapping_strcpy((char*)list, list[0]);
2021 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2025 static char **expand_assignments(char **argv, int count)
2029 /* Expand assignments into one string each */
2030 for (i = 0; i < count; i++) {
2031 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2037 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2038 * and stderr if they are redirected. */
2039 static int setup_redirects(struct command *prog, int squirrel[])
2042 struct redir_struct *redir;
2044 for (redir = prog->redirects; redir; redir = redir->next) {
2045 if (redir->dup == -1 && redir->rd_filename == NULL) {
2046 /* something went wrong in the parse. Pretend it didn't happen */
2049 if (redir->dup == -1) {
2051 mode = redir_table[redir->rd_type].mode;
2052 //TODO: check redir for names like '\\'
2053 p = expand_string_to_string(redir->rd_filename);
2054 openfd = open_or_warn(p, mode);
2057 /* this could get lost if stderr has been redirected, but
2058 bash and ash both lose it as well (though zsh doesn't!) */
2062 openfd = redir->dup;
2065 if (openfd != redir->fd) {
2066 if (squirrel && redir->fd < 3) {
2067 squirrel[redir->fd] = dup(redir->fd);
2070 //close(openfd); // close(-3) ??!
2072 dup2(openfd, redir->fd);
2073 if (redir->dup == -1)
2081 static void restore_redirects(int squirrel[])
2084 for (i = 0; i < 3; i++) {
2087 /* We simply die on error */
2094 #if !defined(DEBUG_CLEAN)
2095 #define free_pipe_list(head, indent) free_pipe_list(head)
2096 #define free_pipe(pi, indent) free_pipe(pi)
2098 static void free_pipe_list(struct pipe *head, int indent);
2100 /* Return code is the exit status of the pipe */
2101 static void free_pipe(struct pipe *pi, int indent)
2104 struct command *command;
2105 struct redir_struct *r, *rnext;
2108 if (pi->stopped_cmds > 0) /* why? */
2110 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2111 for (i = 0; i < pi->num_cmds; i++) {
2112 command = &pi->cmds[i];
2113 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2114 if (command->argv) {
2115 for (a = 0, p = command->argv; *p; a++, p++) {
2116 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2118 free_strings(command->argv);
2119 command->argv = NULL;
2121 /* not "else if": on syntax error, we may have both! */
2122 if (command->group) {
2123 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2124 free_pipe_list(command->group, indent+3);
2125 debug_printf_clean("%s end group\n", indenter(indent));
2126 command->group = NULL;
2129 free(command->group_as_string);
2130 command->group_as_string = NULL;
2132 for (r = command->redirects; r; r = rnext) {
2133 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2135 /* guard against the case >$FOO, where foo is unset or blank */
2136 if (r->rd_filename) {
2137 debug_printf_clean(" %s\n", r->rd_filename);
2138 free(r->rd_filename);
2139 r->rd_filename = NULL;
2142 debug_printf_clean("&%d\n", r->dup);
2147 command->redirects = NULL;
2149 free(pi->cmds); /* children are an array, they get freed all at once */
2157 static void free_pipe_list(struct pipe *head, int indent)
2159 struct pipe *pi, *next;
2161 for (pi = head; pi; pi = next) {
2163 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2165 free_pipe(pi, indent);
2166 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2168 /*pi->next = NULL;*/
2175 typedef struct nommu_save_t {
2181 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2182 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2183 #define pseudo_exec(nommu_save, command, argv_expanded) \
2184 pseudo_exec(command, argv_expanded)
2187 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2189 * XXX no exit() here. If you don't exec, use _exit instead.
2190 * The at_exit handlers apparently confuse the calling process,
2191 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2192 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2193 char **argv, int assignment_cnt,
2194 char **argv_expanded) NORETURN;
2195 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2196 char **argv, int assignment_cnt,
2197 char **argv_expanded)
2201 /* Case when we are here: ... | var=val | ... */
2202 if (!argv[assignment_cnt])
2203 _exit(EXIT_SUCCESS);
2205 new_env = expand_assignments(argv, assignment_cnt);
2207 putenv_all(new_env);
2208 free(new_env); /* optional */
2210 nommu_save->new_env = new_env;
2211 nommu_save->old_env = putenv_all_and_save_old(new_env);
2213 if (argv_expanded) {
2214 argv = argv_expanded;
2216 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2218 nommu_save->argv = argv;
2222 /* On NOMMU, we must never block!
2223 * Example: { sleep 99999 | read line } & echo Ok
2224 * read builtin will block on read syscall, leaving parent blocked
2225 * in vfork. Therefore we can't do this:
2228 /* Check if the command matches any of the builtins.
2229 * Depending on context, this might be redundant. But it's
2230 * easier to waste a few CPU cycles than it is to figure out
2231 * if this is one of those cases.
2235 const struct built_in_command *x;
2236 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2237 if (strcmp(argv[0], x->cmd) == 0) {
2238 debug_printf_exec("running builtin '%s'\n",
2240 rcode = x->function(argv);
2248 #if ENABLE_FEATURE_SH_STANDALONE
2249 /* Check if the command matches any busybox applets */
2250 if (strchr(argv[0], '/') == NULL) {
2251 int a = find_applet_by_name(argv[0]);
2253 #if BB_MMU /* see above why on NOMMU it is not allowed */
2254 if (APPLET_IS_NOEXEC(a)) {
2255 debug_printf_exec("running applet '%s'\n", argv[0]);
2256 run_applet_no_and_exit(a, argv);
2259 /* Re-exec ourselves */
2260 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2261 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2262 execv(bb_busybox_exec_path, argv);
2263 /* If they called chroot or otherwise made the binary no longer
2264 * executable, fall through */
2269 debug_printf_exec("execing '%s'\n", argv[0]);
2270 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2271 execvp(argv[0], argv);
2272 bb_perror_msg("can't exec '%s'", argv[0]);
2273 _exit(EXIT_FAILURE);
2277 static void reset_traps_to_defaults(void)
2285 for (sig = 0; sig < NSIG; sig++) {
2289 G.traps[sig] = NULL;
2290 /* There is no signal for 0 (EXIT) */
2293 /* there was a trap handler, we are removing it
2294 * (if sig has non-DFL handling,
2295 * we don't need to do anything) */
2296 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2298 sigdelset(&G.blocked_set, sig);
2302 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2304 #define clean_up_after_re_execute() ((void)0)
2308 static void re_execute_shell(const char *s) NORETURN;
2309 static void re_execute_shell(const char *s)
2311 struct variable *cur;
2312 char **argv, **pp, **pp2;
2315 /* 1:hush 2:-$<pid> 3:-!<pid> 4:-?<exitcode> 5:-D<depth> <vars...>
2316 * 6:-c 7:<cmd> <argN...> 8:NULL
2318 cnt = 8 + G.global_argc;
2319 for (cur = G.top_var; cur; cur = cur->next) {
2320 if (!cur->flg_export || cur->flg_read_only)
2323 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2324 *pp++ = (char *) G.argv0_for_re_execing;
2325 *pp++ = xasprintf("-$%u", (unsigned) G.root_pid);
2326 *pp++ = xasprintf("-!%u", (unsigned) G.last_bg_pid);
2327 *pp++ = xasprintf("-?%u", (unsigned) G.last_return_code);
2328 #if ENABLE_HUSH_LOOPS
2329 *pp++ = xasprintf("-D%u", G.depth_of_loop);
2331 for (cur = G.top_var; cur; cur = cur->next) {
2332 if (cur->varstr == hush_version_str)
2334 if (cur->flg_read_only) {
2335 *pp++ = (char *) "-R";
2336 *pp++ = cur->varstr;
2337 } else if (!cur->flg_export) {
2338 *pp++ = (char *) "-V";
2339 *pp++ = cur->varstr;
2342 //TODO: pass functions
2343 /* We can pass activated traps here. Say, -Tnn:trap_string
2345 * However, POSIX says that subshells reset signals with traps
2347 * I tested bash-3.2 and it not only does that with true subshells
2348 * of the form ( list ), but with any forked children shells.
2349 * I set trap "echo W" WINCH; and then tried:
2351 * { echo 1; sleep 20; echo 2; } &
2352 * while true; do echo 1; sleep 20; echo 2; break; done &
2353 * true | { echo 1; sleep 20; echo 2; } | cat
2355 * In all these cases sending SIGWINCH to the child shell
2356 * did not run the trap. If I add trap "echo V" WINCH;
2357 * _inside_ group (just before echo 1), it works.
2359 * I conclude it means we don't need to pass active traps here.
2360 * exec syscall below resets them to SIG_DFL for us.
2362 *pp++ = (char *) "-c";
2364 pp2 = G.global_argv;
2367 /* *pp = NULL; - is already there */
2369 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2370 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2371 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2372 /* Fallback. Useful for init=/bin/hush usage etc */
2373 if (G.argv0_for_re_execing[0] == '/')
2374 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2375 xfunc_error_retval = 127;
2376 bb_error_msg_and_die("can't re-execute the shell");
2379 static void clean_up_after_re_execute(void)
2381 char **pp = G.argv_from_re_execing;
2383 /* Must match re_execute_shell's allocations */
2387 #if ENABLE_HUSH_LOOPS
2391 G.argv_from_re_execing = NULL;
2396 static int run_list(struct pipe *pi);
2398 /* Called after [v]fork() in run_pipe()
2400 static void pseudo_exec(nommu_save_t *nommu_save,
2401 struct command *command,
2402 char **argv_expanded) NORETURN;
2403 static void pseudo_exec(nommu_save_t *nommu_save,
2404 struct command *command,
2405 char **argv_expanded)
2407 if (command->argv) {
2408 pseudo_exec_argv(nommu_save, command->argv,
2409 command->assignment_cnt, argv_expanded);
2412 if (command->group) {
2413 /* Cases when we are here:
2416 * ... | ( list ) | ...
2417 * ... | { list } | ...
2421 debug_printf_exec("pseudo_exec: run_list\n");
2422 reset_traps_to_defaults();
2423 rcode = run_list(command->group);
2424 /* OK to leak memory by not calling free_pipe_list,
2425 * since this process is about to exit */
2428 re_execute_shell(command->group_as_string);
2432 /* Case when we are here: ... | >file */
2433 debug_printf_exec("pseudo_exec'ed null command\n");
2434 _exit(EXIT_SUCCESS);
2438 static const char *get_cmdtext(struct pipe *pi)
2444 /* This is subtle. ->cmdtext is created only on first backgrounding.
2445 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2446 * On subsequent bg argv is trashed, but we won't use it */
2449 argv = pi->cmds[0].argv;
2450 if (!argv || !argv[0]) {
2451 pi->cmdtext = xzalloc(1);
2456 do len += strlen(*argv) + 1; while (*++argv);
2457 pi->cmdtext = p = xmalloc(len);
2458 argv = pi->cmds[0].argv;
2460 len = strlen(*argv);
2461 memcpy(p, *argv, len);
2469 static void insert_bg_job(struct pipe *pi)
2471 struct pipe *thejob;
2474 /* Linear search for the ID of the job to use */
2476 for (thejob = G.job_list; thejob; thejob = thejob->next)
2477 if (thejob->jobid >= pi->jobid)
2478 pi->jobid = thejob->jobid + 1;
2480 /* Add thejob to the list of running jobs */
2482 thejob = G.job_list = xmalloc(sizeof(*thejob));
2484 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2486 thejob->next = xmalloc(sizeof(*thejob));
2487 thejob = thejob->next;
2490 /* Physically copy the struct job */
2491 memcpy(thejob, pi, sizeof(struct pipe));
2492 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2493 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2494 for (i = 0; i < pi->num_cmds; i++) {
2495 // TODO: do we really need to have so many fields which are just dead weight
2496 // at execution stage?
2497 thejob->cmds[i].pid = pi->cmds[i].pid;
2498 /* all other fields are not used and stay zero */
2500 thejob->next = NULL;
2501 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2503 /* We don't wait for background thejobs to return -- append it
2504 to the list of backgrounded thejobs and leave it alone */
2505 if (G_interactive_fd)
2506 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2507 G.last_bg_pid = thejob->cmds[0].pid;
2508 G.last_jobid = thejob->jobid;
2511 static void remove_bg_job(struct pipe *pi)
2513 struct pipe *prev_pipe;
2515 if (pi == G.job_list) {
2516 G.job_list = pi->next;
2518 prev_pipe = G.job_list;
2519 while (prev_pipe->next != pi)
2520 prev_pipe = prev_pipe->next;
2521 prev_pipe->next = pi->next;
2524 G.last_jobid = G.job_list->jobid;
2529 /* Remove a backgrounded job */
2530 static void delete_finished_bg_job(struct pipe *pi)
2533 pi->stopped_cmds = 0;
2539 /* Check to see if any processes have exited -- if they
2540 * have, figure out why and see if a job has completed */
2541 static int checkjobs(struct pipe* fg_pipe)
2551 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2554 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2555 // /* avoid doing syscall, nothing there anyway */
2558 attributes = WUNTRACED;
2559 if (fg_pipe == NULL)
2560 attributes |= WNOHANG;
2562 /* Do we do this right?
2563 * bash-3.00# sleep 20 | false
2565 * [3]+ Stopped sleep 20 | false
2566 * bash-3.00# echo $?
2567 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2570 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2571 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2572 // + killall -STOP cat
2579 // i = G.count_SIGCHLD;
2580 childpid = waitpid(-1, &status, attributes);
2581 if (childpid <= 0) {
2582 if (childpid && errno != ECHILD)
2583 bb_perror_msg("waitpid");
2584 // else /* Until next SIGCHLD, waitpid's are useless */
2585 // G.handled_SIGCHLD = i;
2588 dead = WIFEXITED(status) || WIFSIGNALED(status);
2591 if (WIFSTOPPED(status))
2592 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2593 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2594 if (WIFSIGNALED(status))
2595 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2596 childpid, WTERMSIG(status), WEXITSTATUS(status));
2597 if (WIFEXITED(status))
2598 debug_printf_jobs("pid %d exited, exitcode %d\n",
2599 childpid, WEXITSTATUS(status));
2601 /* Were we asked to wait for fg pipe? */
2603 for (i = 0; i < fg_pipe->num_cmds; i++) {
2604 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2605 if (fg_pipe->cmds[i].pid != childpid)
2607 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2609 fg_pipe->cmds[i].pid = 0;
2610 fg_pipe->alive_cmds--;
2611 if (i == fg_pipe->num_cmds - 1) {
2612 /* last process gives overall exitstatus */
2613 rcode = WEXITSTATUS(status);
2614 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2617 fg_pipe->cmds[i].is_stopped = 1;
2618 fg_pipe->stopped_cmds++;
2620 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2621 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2622 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2623 /* All processes in fg pipe have exited/stopped */
2625 if (fg_pipe->alive_cmds)
2626 insert_bg_job(fg_pipe);
2630 /* There are still running processes in the fg pipe */
2631 goto wait_more; /* do waitpid again */
2633 /* it wasnt fg_pipe, look for process in bg pipes */
2637 /* We asked to wait for bg or orphaned children */
2638 /* No need to remember exitcode in this case */
2639 for (pi = G.job_list; pi; pi = pi->next) {
2640 for (i = 0; i < pi->num_cmds; i++) {
2641 if (pi->cmds[i].pid == childpid)
2642 goto found_pi_and_prognum;
2645 /* Happens when shell is used as init process (init=/bin/sh) */
2646 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2647 continue; /* do waitpid again */
2649 found_pi_and_prognum:
2652 pi->cmds[i].pid = 0;
2654 if (!pi->alive_cmds) {
2655 if (G_interactive_fd)
2656 printf(JOB_STATUS_FORMAT, pi->jobid,
2657 "Done", pi->cmdtext);
2658 delete_finished_bg_job(pi);
2662 pi->cmds[i].is_stopped = 1;
2666 } /* while (waitpid succeeds)... */
2672 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2675 int rcode = checkjobs(fg_pipe);
2676 /* Job finished, move the shell to the foreground */
2677 p = getpgid(0); /* pgid of our process */
2678 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2679 tcsetpgrp(G_interactive_fd, p);
2684 /* Start all the jobs, but don't wait for anything to finish.
2687 * Return code is normally -1, when the caller has to wait for children
2688 * to finish to determine the exit status of the pipe. If the pipe
2689 * is a simple builtin command, however, the action is done by the
2690 * time run_pipe returns, and the exit code is provided as the
2693 * Returns -1 only if started some children. IOW: we have to
2694 * mask out retvals of builtins etc with 0xff!
2696 * The only case when we do not need to [v]fork is when the pipe
2697 * is single, non-backgrounded, non-subshell command. Examples:
2698 * cmd ; ... { list } ; ...
2699 * cmd && ... { list } && ...
2700 * cmd || ... { list } || ...
2701 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2702 * or (if SH_STANDALONE) an applet, and we can run the { list }
2703 * with run_list(). If it isn't one of these, we fork and exec cmd.
2705 * Cases when we must fork:
2706 * non-single: cmd | cmd
2707 * backgrounded: cmd & { list } &
2708 * subshell: ( list ) [&]
2710 static int run_pipe(struct pipe *pi)
2712 static const char *const null_ptr = NULL;
2715 int pipefds[2]; /* pipefds[0] is for reading */
2716 struct command *command;
2717 char **argv_expanded;
2720 /* it is not always needed, but we aim to smaller code */
2721 int squirrel[] = { -1, -1, -1 };
2724 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2726 USE_HUSH_JOB(pi->pgrp = -1;)
2727 pi->stopped_cmds = 0;
2728 command = &(pi->cmds[0]);
2729 argv_expanded = NULL;
2731 if (pi->num_cmds != 1
2732 || pi->followup == PIPE_BG
2733 || command->grp_type == GRP_SUBSHELL
2740 debug_printf_exec(": group:%p argv:'%s'\n",
2741 command->group, command->argv ? command->argv[0] : "NONE");
2743 if (command->group) {
2744 #if ENABLE_HUSH_FUNCTIONS
2745 if (command->grp_type == GRP_FUNCTION) {
2746 /* func () { list } */
2747 bb_error_msg("here we ought to remember function definition, and go on");
2748 return EXIT_SUCCESS;
2752 debug_printf("non-subshell group\n");
2753 setup_redirects(command, squirrel);
2754 debug_printf_exec(": run_list\n");
2755 rcode = run_list(command->group) & 0xff;
2756 restore_redirects(squirrel);
2757 debug_printf_exec("run_pipe return %d\n", rcode);
2758 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2762 argv = command->argv ? command->argv : (char **) &null_ptr;
2764 const struct built_in_command *x;
2765 char **new_env = NULL;
2766 char **old_env = NULL;
2768 if (argv[command->assignment_cnt] == NULL) {
2769 /* Assignments, but no command */
2770 /* Ensure redirects take effect. Try "a=t >file" */
2771 setup_redirects(command, squirrel);
2772 restore_redirects(squirrel);
2773 /* Set shell variables */
2775 p = expand_string_to_string(*argv);
2776 debug_printf_exec("set shell var:'%s'->'%s'\n",
2778 set_local_var(p, 0, 0);
2781 /* Do we need to flag set_local_var() errors?
2782 * "assignment to readonly var" and "putenv error"
2784 return EXIT_SUCCESS;
2787 /* Expand the rest into (possibly) many strings each */
2788 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2790 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2791 if (strcmp(argv_expanded[0], x->cmd) != 0)
2793 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2794 debug_printf("exec with redirects only\n");
2795 setup_redirects(command, NULL);
2796 rcode = EXIT_SUCCESS;
2797 goto clean_up_and_ret1;
2799 debug_printf("builtin inline %s\n", argv_expanded[0]);
2800 /* XXX setup_redirects acts on file descriptors, not FILEs.
2801 * This is perfect for work that comes after exec().
2802 * Is it really safe for inline use? Experimentally,
2803 * things seem to work with glibc. */
2804 setup_redirects(command, squirrel);
2805 new_env = expand_assignments(argv, command->assignment_cnt);
2806 old_env = putenv_all_and_save_old(new_env);
2807 debug_printf_exec(": builtin '%s' '%s'...\n",
2808 x->cmd, argv_expanded[1]);
2809 rcode = x->function(argv_expanded) & 0xff;
2810 #if ENABLE_FEATURE_SH_STANDALONE
2813 restore_redirects(squirrel);
2814 free_strings_and_unsetenv(new_env, 1);
2815 putenv_all(old_env);
2816 free(old_env); /* not free_strings()! */
2818 free(argv_expanded);
2819 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2820 debug_printf_exec("run_pipe return %d\n", rcode);
2823 #if ENABLE_FEATURE_SH_STANDALONE
2824 i = find_applet_by_name(argv_expanded[0]);
2825 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2826 setup_redirects(command, squirrel);
2827 save_nofork_data(&G.nofork_save);
2828 new_env = expand_assignments(argv, command->assignment_cnt);
2829 old_env = putenv_all_and_save_old(new_env);
2830 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2831 argv_expanded[0], argv_expanded[1]);
2832 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2833 goto clean_up_and_ret;
2836 /* It is neither builtin nor applet. We must fork. */
2840 /* NB: argv_expanded may already be created, and that
2841 * might include `cmd` runs! Do not rerun it! We *must*
2842 * use argv_expanded if it's non-NULL */
2844 /* Going to fork a child per each pipe member */
2848 for (i = 0; i < pi->num_cmds; i++) {
2850 volatile nommu_save_t nommu_save;
2851 nommu_save.new_env = NULL;
2852 nommu_save.old_env = NULL;
2853 nommu_save.argv = NULL;
2855 command = &(pi->cmds[i]);
2856 if (command->argv) {
2857 debug_printf_exec(": pipe member '%s' '%s'...\n",
2858 command->argv[0], command->argv[1]);
2860 debug_printf_exec(": pipe member with no argv\n");
2863 /* pipes are inserted between pairs of commands */
2866 if ((i + 1) < pi->num_cmds)
2869 command->pid = BB_MMU ? fork() : vfork();
2870 if (!command->pid) { /* child */
2872 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
2874 /* Every child adds itself to new process group
2875 * with pgid == pid_of_first_child_in_pipe */
2876 if (G.run_list_level == 1 && G_interactive_fd) {
2879 if (pgrp < 0) /* true for 1st process only */
2881 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2882 /* We do it in *every* child, not just first,
2884 tcsetpgrp(G_interactive_fd, pgrp);
2888 xmove_fd(nextin, 0);
2889 xmove_fd(pipefds[1], 1); /* write end */
2891 close(pipefds[0]); /* read end */
2892 /* Like bash, explicit redirects override pipes,
2893 * and the pipe fd is available for dup'ing. */
2894 setup_redirects(command, NULL);
2896 /* Restore default handlers just prior to exec */
2897 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2899 /* Stores to nommu_save list of env vars putenv'ed
2900 * (NOMMU, on MMU we don't need that) */
2901 /* cast away volatility... */
2902 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2903 /* pseudo_exec() does not return */
2906 /* parent or error */
2908 die_sleep = -1; /* restore tty pgrp on xfunc death */
2911 /* Clean up after vforked child */
2912 clean_up_after_re_execute();
2913 free(nommu_save.argv);
2914 free_strings_and_unsetenv(nommu_save.new_env, 1);
2915 putenv_all(nommu_save.old_env);
2917 free(argv_expanded);
2918 argv_expanded = NULL;
2919 if (command->pid < 0) { /* [v]fork failed */
2920 /* Clearly indicate, was it fork or vfork */
2921 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2925 /* Second and next children need to know pid of first one */
2927 pi->pgrp = command->pid;
2933 if ((i + 1) < pi->num_cmds)
2934 close(pipefds[1]); /* write end */
2935 /* Pass read (output) pipe end to next iteration */
2936 nextin = pipefds[0];
2939 if (!pi->alive_cmds) {
2940 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2944 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2948 #ifndef debug_print_tree
2949 static void debug_print_tree(struct pipe *pi, int lvl)
2951 static const char *const PIPE[] = {
2957 static const char *RES[] = {
2958 [RES_NONE ] = "NONE" ,
2961 [RES_THEN ] = "THEN" ,
2962 [RES_ELIF ] = "ELIF" ,
2963 [RES_ELSE ] = "ELSE" ,
2966 #if ENABLE_HUSH_LOOPS
2967 [RES_FOR ] = "FOR" ,
2968 [RES_WHILE] = "WHILE",
2969 [RES_UNTIL] = "UNTIL",
2971 [RES_DONE ] = "DONE" ,
2973 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2976 #if ENABLE_HUSH_CASE
2977 [RES_CASE ] = "CASE" ,
2978 [RES_MATCH] = "MATCH",
2979 [RES_CASEI] = "CASEI",
2980 [RES_ESAC ] = "ESAC" ,
2982 [RES_XXXX ] = "XXXX" ,
2983 [RES_SNTX ] = "SNTX" ,
2985 static const char *const GRPTYPE[] = {
2988 #if ENABLE_HUSH_FUNCTIONS
2997 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2998 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3000 while (prn < pi->num_cmds) {
3001 struct command *command = &pi->cmds[prn];
3002 char **argv = command->argv;
3004 fprintf(stderr, "%*s prog %d assignment_cnt:%d",
3006 command->assignment_cnt);
3007 if (command->group) {
3008 fprintf(stderr, " group %s: (argv=%p)\n",
3009 GRPTYPE[command->grp_type],
3011 debug_print_tree(command->group, lvl+1);
3015 if (argv) while (*argv) {
3016 fprintf(stderr, " '%s'", *argv);
3019 fprintf(stderr, "\n");
3028 /* NB: called by pseudo_exec, and therefore must not modify any
3029 * global data until exec/_exit (we can be a child after vfork!) */
3030 static int run_list(struct pipe *pi)
3032 #if ENABLE_HUSH_CASE
3033 char *case_word = NULL;
3035 #if ENABLE_HUSH_LOOPS
3036 struct pipe *loop_top = NULL;
3037 char *for_varname = NULL;
3038 char **for_lcur = NULL;
3039 char **for_list = NULL;
3041 smallint flag_skip = 1;
3042 smalluint rcode = 0; /* probably just for compiler */
3043 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3044 smalluint cond_code = 0;
3046 enum { cond_code = 0, };
3048 /*enum reserved_style*/ smallint rword = RES_NONE;
3049 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
3051 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3053 #if ENABLE_HUSH_LOOPS
3054 /* Check syntax for "for" */
3055 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3056 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3058 /* current word is FOR or IN (BOLD in comments below) */
3059 if (cpipe->next == NULL) {
3060 syntax("malformed for");
3061 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3064 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3065 if (cpipe->next->res_word == RES_DO)
3067 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3068 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3069 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3071 syntax("malformed for");
3072 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3078 /* Past this point, all code paths should jump to ret: label
3079 * in order to return, no direct "return" statements please.
3080 * This helps to ensure that no memory is leaked. */
3082 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3085 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3086 * We are saving state before entering outermost list ("while...done")
3087 * so that ctrl-Z will correctly background _entire_ outermost list,
3088 * not just a part of it (like "sleep 1 | exit 2") */
3089 if (++G.run_list_level == 1 && G_interactive_fd) {
3090 if (sigsetjmp(G.toplevel_jb, 1)) {
3091 /* ctrl-Z forked and we are parent; or ctrl-C.
3092 * Sighandler has longjmped us here */
3093 signal(SIGINT, SIG_IGN);
3094 signal(SIGTSTP, SIG_IGN);
3095 /* Restore level (we can be coming from deep inside
3097 G.run_list_level = 1;
3098 #if ENABLE_FEATURE_SH_STANDALONE
3099 if (G.nofork_save.saved) { /* if save area is valid */
3100 debug_printf_jobs("exiting nofork early\n");
3101 restore_nofork_data(&G.nofork_save);
3104 //// if (G.ctrl_z_flag) {
3105 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3106 //// * Remember this child as background job */
3107 //// insert_bg_job(pi);
3109 /* ctrl-C. We just stop doing whatever we were doing */
3112 USE_HUSH_LOOPS(loop_top = NULL;)
3113 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3117 //// /* ctrl-Z handler will store pid etc in pi */
3118 //// G.toplevel_list = pi;
3119 //// G.ctrl_z_flag = 0;
3120 ////#if ENABLE_FEATURE_SH_STANDALONE
3121 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3123 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3124 //// signal(SIGINT, handler_ctrl_c);
3128 /* Go through list of pipes, (maybe) executing them. */
3129 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3133 IF_HAS_KEYWORDS(rword = pi->res_word;)
3134 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
3135 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
3136 rword, cond_code, skip_more_for_this_rword);
3137 #if ENABLE_HUSH_LOOPS
3138 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3139 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3141 /* start of a loop: remember where loop starts */
3146 if (rword == skip_more_for_this_rword && flag_skip) {
3147 if (pi->followup == PIPE_SEQ)
3149 /* it is "<false> && CMD" or "<true> || CMD"
3150 * and we should not execute CMD */
3154 skip_more_for_this_rword = RES_XXXX;
3157 if (rword == RES_THEN) {
3158 /* "if <false> THEN cmd": skip cmd */
3162 if (rword == RES_ELSE || rword == RES_ELIF) {
3163 /* "if <true> then ... ELSE/ELIF cmd":
3164 * skip cmd and all following ones */
3169 #if ENABLE_HUSH_LOOPS
3170 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3172 /* first loop through for */
3174 static const char encoded_dollar_at[] ALIGN1 = {
3175 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3176 }; /* encoded representation of "$@" */
3177 static const char *const encoded_dollar_at_argv[] = {
3178 encoded_dollar_at, NULL
3179 }; /* argv list with one element: "$@" */
3182 vals = (char**)encoded_dollar_at_argv;
3183 if (pi->next->res_word == RES_IN) {
3184 /* if no variable values after "in" we skip "for" */
3185 if (!pi->next->cmds[0].argv)
3187 vals = pi->next->cmds[0].argv;
3188 } /* else: "for var; do..." -> assume "$@" list */
3189 /* create list of variable values */
3190 debug_print_strings("for_list made from", vals);
3191 for_list = expand_strvec_to_strvec(vals);
3192 for_lcur = for_list;
3193 debug_print_strings("for_list", for_list);
3194 for_varname = pi->cmds[0].argv[0];
3195 pi->cmds[0].argv[0] = NULL;
3197 free(pi->cmds[0].argv[0]);
3199 /* "for" loop is over, clean up */
3203 pi->cmds[0].argv[0] = for_varname;
3206 /* insert next value from for_lcur */
3207 //TODO: does it need escaping?
3208 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3209 pi->cmds[0].assignment_cnt = 1;
3211 if (rword == RES_IN) {
3212 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3214 if (rword == RES_DONE) {
3215 continue; /* "done" has no cmds too */
3218 #if ENABLE_HUSH_CASE
3219 if (rword == RES_CASE) {
3220 case_word = expand_strvec_to_string(pi->cmds->argv);
3223 if (rword == RES_MATCH) {
3226 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3228 /* all prev words didn't match, does this one match? */
3229 argv = pi->cmds->argv;
3231 char *pattern = expand_string_to_string(*argv);
3232 /* TODO: which FNM_xxx flags to use? */
3233 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3235 if (cond_code == 0) { /* match! we will execute this branch */
3236 free(case_word); /* make future "word)" stop */
3244 if (rword == RES_CASEI) { /* inside of a case branch */
3246 continue; /* not matched yet, skip this pipe */
3249 /* Just pressing <enter> in shell should check for jobs.
3250 * OTOH, in non-interactive shell this is useless
3251 * and only leads to extra job checks */
3252 if (pi->num_cmds == 0) {
3253 if (G_interactive_fd)
3254 goto check_jobs_and_continue;
3258 /* After analyzing all keywords and conditions, we decided
3259 * to execute this pipe. NB: have to do checkjobs(NULL)
3260 * after run_pipe() to collect any background children,
3261 * even if list execution is to be stopped. */
3262 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3265 #if ENABLE_HUSH_LOOPS
3266 G.flag_break_continue = 0;
3268 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3270 /* we only ran a builtin: rcode is already known
3271 * and we don't need to wait for anything. */
3272 check_and_run_traps(0);
3273 #if ENABLE_HUSH_LOOPS
3274 /* was it "break" or "continue"? */
3275 if (G.flag_break_continue) {
3276 smallint fbc = G.flag_break_continue;
3277 /* we might fall into outer *loop*,
3278 * don't want to break it too */
3280 G.depth_break_continue--;
3281 if (G.depth_break_continue == 0)
3282 G.flag_break_continue = 0;
3283 /* else: e.g. "continue 2" should *break* once, *then* continue */
3284 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3285 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3286 goto check_jobs_and_break;
3287 /* "continue": simulate end of loop */
3292 } else if (pi->followup == PIPE_BG) {
3293 /* what does bash do with attempts to background builtins? */
3294 /* even bash 3.2 doesn't do that well with nested bg:
3295 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3296 * I'm NOT treating inner &'s as jobs */
3297 check_and_run_traps(0);
3299 if (G.run_list_level == 1)
3302 rcode = 0; /* EXIT_SUCCESS */
3305 if (G.run_list_level == 1 && G_interactive_fd) {
3306 /* waits for completion, then fg's main shell */
3307 rcode = checkjobs_and_fg_shell(pi);
3308 check_and_run_traps(0);
3309 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3312 { /* this one just waits for completion */
3313 rcode = checkjobs(pi);
3314 check_and_run_traps(0);
3315 debug_printf_exec(": checkjobs returned %d\n", rcode);
3319 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3320 G.last_return_code = rcode;
3322 /* Analyze how result affects subsequent commands */
3324 if (rword == RES_IF || rword == RES_ELIF)
3327 #if ENABLE_HUSH_LOOPS
3328 if (rword == RES_WHILE) {
3330 rcode = 0; /* "while false; do...done" - exitcode 0 */
3331 goto check_jobs_and_break;
3334 if (rword == RES_UNTIL) {
3336 check_jobs_and_break:
3342 if ((rcode == 0 && pi->followup == PIPE_OR)
3343 || (rcode != 0 && pi->followup == PIPE_AND)
3345 skip_more_for_this_rword = rword;
3348 check_jobs_and_continue:
3353 //// if (G.ctrl_z_flag) {
3354 //// /* ctrl-Z forked somewhere in the past, we are the child,
3355 //// * and now we completed running the list. Exit. */
3361 //// if (!G.run_list_level && G_interactive_fd) {
3362 //// signal(SIGTSTP, SIG_IGN);
3363 //// signal(SIGINT, SIG_IGN);
3366 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3367 #if ENABLE_HUSH_LOOPS
3372 #if ENABLE_HUSH_CASE
3378 /* Select which version we will use */
3379 static int run_and_free_list(struct pipe *pi)
3382 debug_printf_exec("run_and_free_list entered\n");
3384 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3385 rcode = run_list(pi);
3387 /* free_pipe_list has the side effect of clearing memory.
3388 * In the long run that function can be merged with run_list,
3389 * but doing that now would hobble the debugging effort. */
3390 free_pipe_list(pi, /* indent: */ 0);
3391 debug_printf_exec("run_and_free_list return %d\n", rcode);
3396 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3397 * as in "2>&1", that represents duplicating a file descriptor.
3398 * Return either -2 (syntax error), -1 (no &), or the number found.
3400 static int redirect_dup_num(struct in_str *input)
3402 int ch, d = 0, ok = 0;
3404 if (ch != '&') return -1;
3406 i_getch(input); /* get the & */
3410 return -3; /* "-" represents "close me" */
3412 while (isdigit(ch)) {
3413 d = d*10 + (ch-'0');
3420 bb_error_msg("ambiguous redirect");
3424 /* The src parameter allows us to peek forward to a possible &n syntax
3425 * for file descriptor duplication, e.g., "2>&1".
3426 * Return code is 0 normally, 1 if a syntax error is detected in src.
3427 * Resource errors (in xmalloc) cause the process to exit */
3428 static int setup_redirect(struct parse_context *ctx,
3431 struct in_str *input)
3433 struct command *command = ctx->command;
3434 struct redir_struct *redir;
3435 struct redir_struct **redirp;
3438 /* Check for a '2>&1' type redirect */
3439 dup_num = redirect_dup_num(input);
3441 return 1; /* syntax error */
3443 /* Create a new redir_struct and drop it onto the end of the linked list */
3444 redirp = &command->redirects;
3445 while ((redir = *redirp) != NULL) {
3446 redirp = &(redir->next);
3448 *redirp = redir = xzalloc(sizeof(*redir));
3449 /* redir->next = NULL; */
3450 /* redir->rd_filename = NULL; */
3451 redir->rd_type = style;
3452 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3454 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3456 redir->dup = dup_num;
3457 if (dup_num != -1) {
3458 /* Erik had a check here that the file descriptor in question
3459 * is legit; I postpone that to "run time"
3460 * A "-" representation of "close me" shows up as a -3 here */
3461 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3463 /* We do _not_ try to open the file that src points to,
3464 * since we need to return and let src be expanded first.
3465 * Set ctx->pending_redirect, so we know what to do at the
3466 * end of the next parsed word. */
3467 ctx->pending_redirect = redir;
3473 static struct pipe *new_pipe(void)
3476 pi = xzalloc(sizeof(struct pipe));
3477 /*pi->followup = 0; - deliberately invalid value */
3478 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3482 /* Command (member of a pipe) is complete. The only possible error here
3483 * is out of memory, in which case xmalloc exits. */
3484 static int done_command(struct parse_context *ctx)
3486 /* The command is really already in the pipe structure, so
3487 * advance the pipe counter and make a new, null command. */
3488 struct pipe *pi = ctx->pipe;
3489 struct command *command = ctx->command;
3492 if (command->group == NULL
3493 && command->argv == NULL
3494 && command->redirects == NULL
3496 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3497 return pi->num_cmds;
3500 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3502 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3505 /* Only real trickiness here is that the uncommitted
3506 * command structure is not counted in pi->num_cmds. */
3507 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3508 command = &pi->cmds[pi->num_cmds];
3509 memset(command, 0, sizeof(*command));
3511 ctx->command = command;
3512 /* but ctx->pipe and ctx->list_head remain unchanged */
3514 return pi->num_cmds; /* used only for 0/nonzero check */
3517 static void done_pipe(struct parse_context *ctx, pipe_style type)
3521 debug_printf_parse("done_pipe entered, followup %d\n", type);
3522 /* Close previous command */
3523 not_null = done_command(ctx);
3524 ctx->pipe->followup = type;
3525 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3526 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3527 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3529 /* Without this check, even just <enter> on command line generates
3530 * tree of three NOPs (!). Which is harmless but annoying.
3531 * IOW: it is safe to do it unconditionally.
3532 * RES_NONE case is for "for a in; do ..." (empty IN set)
3533 * to work, possibly other cases too. */
3534 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3536 debug_printf_parse("done_pipe: adding new pipe: "
3537 "not_null:%d ctx->ctx_res_w:%d\n",
3538 not_null, ctx->ctx_res_w);
3540 ctx->pipe->next = new_p;
3542 /* RES_THEN, RES_DO etc are "sticky" -
3543 * they remain set for commands inside if/while.
3544 * This is used to control execution.
3545 * RES_FOR and RES_IN are NOT sticky (needed to support
3546 * cases where variable or value happens to match a keyword):
3548 #if ENABLE_HUSH_LOOPS
3549 if (ctx->ctx_res_w == RES_FOR
3550 || ctx->ctx_res_w == RES_IN)
3551 ctx->ctx_res_w = RES_NONE;
3553 #if ENABLE_HUSH_CASE
3554 if (ctx->ctx_res_w == RES_MATCH)
3555 ctx->ctx_res_w = RES_CASEI;
3557 ctx->command = NULL; /* trick done_command below */
3558 /* Create the memory for command, roughly:
3559 * ctx->pipe->cmds = new struct command;
3560 * ctx->command = &ctx->pipe->cmds[0];
3564 debug_printf_parse("done_pipe return\n");
3567 static void initialize_context(struct parse_context *ctx)
3569 memset(ctx, 0, sizeof(*ctx));
3570 ctx->pipe = ctx->list_head = new_pipe();
3571 /* Create the memory for command, roughly:
3572 * ctx->pipe->cmds = new struct command;
3573 * ctx->command = &ctx->pipe->cmds[0];
3579 /* If a reserved word is found and processed, parse context is modified
3580 * and 1 is returned.
3583 struct reserved_combo {
3586 unsigned char assignment_flag;
3590 FLAG_END = (1 << RES_NONE ),
3592 FLAG_IF = (1 << RES_IF ),
3593 FLAG_THEN = (1 << RES_THEN ),
3594 FLAG_ELIF = (1 << RES_ELIF ),
3595 FLAG_ELSE = (1 << RES_ELSE ),
3596 FLAG_FI = (1 << RES_FI ),
3598 #if ENABLE_HUSH_LOOPS
3599 FLAG_FOR = (1 << RES_FOR ),
3600 FLAG_WHILE = (1 << RES_WHILE),
3601 FLAG_UNTIL = (1 << RES_UNTIL),
3602 FLAG_DO = (1 << RES_DO ),
3603 FLAG_DONE = (1 << RES_DONE ),
3604 FLAG_IN = (1 << RES_IN ),
3606 #if ENABLE_HUSH_CASE
3607 FLAG_MATCH = (1 << RES_MATCH),
3608 FLAG_ESAC = (1 << RES_ESAC ),
3610 FLAG_START = (1 << RES_XXXX ),
3613 static const struct reserved_combo* match_reserved_word(o_string *word)
3615 /* Mostly a list of accepted follow-up reserved words.
3616 * FLAG_END means we are done with the sequence, and are ready
3617 * to turn the compound list into a command.
3618 * FLAG_START means the word must start a new compound list.
3620 static const struct reserved_combo reserved_list[] = {
3622 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3623 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3624 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3625 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3626 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3627 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3629 #if ENABLE_HUSH_LOOPS
3630 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3631 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3632 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3633 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3634 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3635 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3637 #if ENABLE_HUSH_CASE
3638 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3639 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3642 const struct reserved_combo *r;
3644 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3645 if (strcmp(word->data, r->literal) == 0)
3650 static int reserved_word(o_string *word, struct parse_context *ctx)
3652 #if ENABLE_HUSH_CASE
3653 static const struct reserved_combo reserved_match = {
3654 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3657 const struct reserved_combo *r;
3659 r = match_reserved_word(word);
3663 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3664 #if ENABLE_HUSH_CASE
3665 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3666 /* "case word IN ..." - IN part starts first match part */
3667 r = &reserved_match;
3670 if (r->flag == 0) { /* '!' */
3671 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3672 syntax("! ! command");
3673 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3675 ctx->ctx_inverted = 1;
3678 if (r->flag & FLAG_START) {
3679 struct parse_context *old;
3680 old = xmalloc(sizeof(*old));
3681 debug_printf_parse("push stack %p\n", old);
3682 *old = *ctx; /* physical copy */
3683 initialize_context(ctx);
3685 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3687 ctx->ctx_res_w = RES_SNTX;
3690 ctx->ctx_res_w = r->res;
3691 ctx->old_flag = r->flag;
3692 if (ctx->old_flag & FLAG_END) {
3693 struct parse_context *old;
3694 done_pipe(ctx, PIPE_SEQ);
3695 debug_printf_parse("pop stack %p\n", ctx->stack);
3697 old->command->group = ctx->list_head;
3698 old->command->grp_type = GRP_NORMAL;
3700 o_addstr(&old->as_string, ctx->as_string.data);
3701 o_free_unsafe(&ctx->as_string);
3702 old->command->group_as_string = xstrdup(old->as_string.data);
3703 debug_printf_parse("pop, remembering as:'%s'\n",
3704 old->command->group_as_string);
3706 *ctx = *old; /* physical copy */
3709 word->o_assignment = r->assignment_flag;
3714 /* Word is complete, look at it and update parsing context.
3715 * Normal return is 0. Syntax errors return 1.
3716 * Note: on return, word is reset, but not o_free'd!
3718 static int done_word(o_string *word, struct parse_context *ctx)
3720 struct command *command = ctx->command;
3722 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3723 if (word->length == 0 && word->nonnull == 0) {
3724 debug_printf_parse("done_word return 0: true null, ignored\n");
3727 /* If this word wasn't an assignment, next ones definitely
3728 * can't be assignments. Even if they look like ones. */
3729 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3730 && word->o_assignment != WORD_IS_KEYWORD
3732 word->o_assignment = NOT_ASSIGNMENT;
3734 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3735 command->assignment_cnt++;
3736 word->o_assignment = MAYBE_ASSIGNMENT;
3739 if (ctx->pending_redirect) {
3740 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3741 * only if run as "bash", not "sh" */
3742 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3743 word->o_assignment = NOT_ASSIGNMENT;
3744 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3746 /* "{ echo foo; } echo bar" - bad */
3747 /* NB: bash allows e.g.:
3748 * if true; then { echo foo; } fi
3749 * while if false; then false; fi do break; done
3751 if (command->group) {
3753 debug_printf_parse("done_word return 1: syntax error, "
3754 "groups and arglists don't mix\n");
3758 #if ENABLE_HUSH_CASE
3759 if (ctx->ctx_dsemicolon
3760 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3762 /* already done when ctx_dsemicolon was set to 1: */
3763 /* ctx->ctx_res_w = RES_MATCH; */
3764 ctx->ctx_dsemicolon = 0;
3767 if (!command->argv /* if it's the first word... */
3768 #if ENABLE_HUSH_LOOPS
3769 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3770 && ctx->ctx_res_w != RES_IN
3773 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3774 if (reserved_word(word, ctx)) {
3776 debug_printf_parse("done_word return %d\n",
3777 (ctx->ctx_res_w == RES_SNTX));
3778 return (ctx->ctx_res_w == RES_SNTX);
3782 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3783 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3784 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3785 /* (otherwise it's known to be not empty and is already safe) */
3787 /* exclude "$@" - it can expand to no word despite "" */
3788 char *p = word->data;
3789 while (p[0] == SPECIAL_VAR_SYMBOL
3790 && (p[1] & 0x7f) == '@'
3791 && p[2] == SPECIAL_VAR_SYMBOL
3795 if (p == word->data || p[0] != '\0') {
3796 /* saw no "$@", or not only "$@" but some
3797 * real text is there too */
3798 /* insert "empty variable" reference, this makes
3799 * e.g. "", $empty"" etc to not disappear */
3800 o_addchr(word, SPECIAL_VAR_SYMBOL);
3801 o_addchr(word, SPECIAL_VAR_SYMBOL);
3804 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3805 debug_print_strings("word appended to argv", command->argv);
3809 ctx->pending_redirect = NULL;
3811 #if ENABLE_HUSH_LOOPS
3812 /* Force FOR to have just one word (variable name) */
3813 /* NB: basically, this makes hush see "for v in ..." syntax as if
3814 * as it is "for v; in ...". FOR and IN become two pipe structs
3816 if (ctx->ctx_res_w == RES_FOR) {
3817 //TODO: check that command->argv[0] is a valid variable name!
3818 done_pipe(ctx, PIPE_SEQ);
3821 #if ENABLE_HUSH_CASE
3822 /* Force CASE to have just one word */
3823 if (ctx->ctx_res_w == RES_CASE) {
3824 done_pipe(ctx, PIPE_SEQ);
3827 debug_printf_parse("done_word return 0\n");
3831 /* If a redirect is immediately preceded by a number, that number is
3832 * supposed to tell which file descriptor to redirect. This routine
3833 * looks for such preceding numbers. In an ideal world this routine
3834 * needs to handle all the following classes of redirects...
3835 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3836 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3837 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3838 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3839 * A -1 output from this program means no valid number was found, so the
3840 * caller should use the appropriate default for this redirection.
3842 static int redirect_opt_num(o_string *o)
3848 for (num = 0; num < o->length; num++) {
3849 if (!isdigit(o->data[num])) {
3853 num = atoi(o->data);
3859 #define parse_stream(pstring, input, end_trigger) \
3860 parse_stream(input, end_trigger)
3862 static struct pipe *parse_stream(char **pstring,
3863 struct in_str *input,
3865 static void parse_and_run_string(const char *s);
3867 #if ENABLE_HUSH_TICK
3868 static FILE *generate_stream_from_string(const char *s)
3871 int pid, channel[2];
3874 pid = BB_MMU ? fork() : vfork();
3876 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3878 if (pid == 0) { /* child */
3880 die_sleep = 0; /* do not restore tty pgrp on xfunc death */
3882 /* Process substitution is not considered to be usual
3883 * 'command execution'.
3884 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3891 close(channel[0]); /* NB: close _first_, then move fd! */
3892 xmove_fd(channel[1], 1);
3893 /* Prevent it from trying to handle ctrl-z etc */
3894 USE_HUSH_JOB(G.run_list_level = 1;)
3896 reset_traps_to_defaults();
3897 parse_and_run_string(s);
3898 _exit(G.last_return_code);
3900 /* We re-execute after vfork on NOMMU. This makes this script safe:
3901 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
3902 * huge=`cat BIG` # was blocking here forever
3905 re_execute_shell(s);
3911 die_sleep = -1; /* restore tty pgrp on xfunc death */
3913 clean_up_after_re_execute();
3915 pf = fdopen(channel[0], "r");
3919 /* Return code is exit status of the process that is run. */
3920 static int process_command_subs(o_string *dest, const char *s)
3923 struct in_str pipe_str;
3926 pf = generate_stream_from_string(s);
3929 close_on_exec_on(fileno(pf));
3931 /* Now send results of command back into original context */
3932 setup_file_in_str(&pipe_str, pf);
3934 while ((ch = i_getch(&pipe_str)) != EOF) {
3940 o_addchr(dest, '\n');
3943 o_addQchr(dest, ch);
3946 debug_printf("done reading from pipe, pclose()ing\n");
3947 /* Note: we got EOF, and we just close the read end of the pipe.
3948 * We do not wait for the `cmd` child to terminate. bash and ash do.
3950 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
3951 * `false`; echo $? - bash outputs "1"
3954 debug_printf("closed FILE from child. return 0\n");
3959 static int parse_group(o_string *dest, struct parse_context *ctx,
3960 struct in_str *input, int ch)
3962 /* dest contains characters seen prior to ( or {.
3963 * Typically it's empty, but for function defs,
3964 * it contains function name (without '()'). */
3965 struct pipe *pipe_list;
3967 struct command *command = ctx->command;
3969 debug_printf_parse("parse_group entered\n");
3970 #if ENABLE_HUSH_FUNCTIONS
3971 if (ch == 'F') { /* function definition? */
3972 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3973 //command->fname = dest->data;
3974 command->grp_type = GRP_FUNCTION;
3975 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3976 memset(dest, 0, sizeof(*dest));
3979 if (command->argv /* word [word](... */
3980 || dest->length /* word(... */
3981 || dest->nonnull /* ""(... */
3984 debug_printf_parse("parse_group return 1: "
3985 "syntax error, groups and arglists don't mix\n");
3991 command->grp_type = GRP_SUBSHELL;
3995 char *as_string = NULL;
3997 pipe_list = parse_stream(&as_string, input, endch);
4000 o_addstr(&ctx->as_string, as_string);
4002 /* empty ()/{} or parse error? */
4003 if (!pipe_list || pipe_list == ERR_PTR) {
4008 debug_printf_parse("parse_group return 1: "
4009 "parse_stream returned %p\n", pipe_list);
4012 command->group = pipe_list;
4014 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4015 command->group_as_string = as_string;
4016 debug_printf_parse("end of group, remembering as:'%s'\n",
4017 command->group_as_string);
4020 debug_printf_parse("parse_group return 0\n");
4022 /* command remains "open", available for possible redirects */
4025 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4026 /* Subroutines for copying $(...) and `...` things */
4027 static void add_till_backquote(o_string *dest, struct in_str *input);
4029 static void add_till_single_quote(o_string *dest, struct in_str *input)
4032 int ch = i_getch(input);
4040 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4041 static void add_till_double_quote(o_string *dest, struct in_str *input)
4044 int ch = i_getch(input);
4047 if (ch == '\\') { /* \x. Copy both chars. */
4049 ch = i_getch(input);
4055 add_till_backquote(dest, input);
4059 //if (ch == '$') ...
4062 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4064 * "Within the backquoted style of command substitution, backslash
4065 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4066 * The search for the matching backquote shall be satisfied by the first
4067 * backquote found without a preceding backslash; during this search,
4068 * if a non-escaped backquote is encountered within a shell comment,
4069 * a here-document, an embedded command substitution of the $(command)
4070 * form, or a quoted string, undefined results occur. A single-quoted
4071 * or double-quoted string that begins, but does not end, within the
4072 * "`...`" sequence produces undefined results."
4074 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4076 static void add_till_backquote(o_string *dest, struct in_str *input)
4079 int ch = i_getch(input);
4082 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4083 int ch2 = i_getch(input);
4084 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4093 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4094 * quoting and nested ()s.
4095 * "With the $(command) style of command substitution, all characters
4096 * following the open parenthesis to the matching closing parenthesis
4097 * constitute the command. Any valid shell script can be used for command,
4098 * except a script consisting solely of redirections which produces
4099 * unspecified results."
4101 * echo $(echo '(TEST)' BEST) (TEST) BEST
4102 * echo $(echo 'TEST)' BEST) TEST) BEST
4103 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4105 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4109 int ch = i_getch(input);
4118 if (i_peek(input) == ')') {
4126 add_till_single_quote(dest, input);
4131 add_till_double_quote(dest, input);
4135 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4136 ch = i_getch(input);
4144 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4146 /* Return code: 0 for OK, 1 for syntax error */
4148 #define handle_dollar(as_string, dest, input) \
4149 handle_dollar(dest, input)
4151 static int handle_dollar(o_string *as_string,
4153 struct in_str *input)
4156 int ch = i_peek(input); /* first character after the $ */
4157 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4159 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4161 ch = i_getch(input);
4163 if (as_string) o_addchr(as_string, ch);
4166 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4168 debug_printf_parse(": '%c'\n", ch);
4169 o_addchr(dest, ch | quote_mask);
4172 if (!isalnum(ch) && ch != '_')
4174 ch = i_getch(input);
4176 if (as_string) o_addchr(as_string, ch);
4179 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4180 } else if (isdigit(ch)) {
4182 ch = i_getch(input);
4184 if (as_string) o_addchr(as_string, ch);
4186 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4187 debug_printf_parse(": '%c'\n", ch);
4188 o_addchr(dest, ch | quote_mask);
4189 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4190 } else switch (ch) {
4192 case '!': /* last bg pid */
4193 case '?': /* last exit code */
4194 case '#': /* number of args */
4195 case '*': /* args */
4196 case '@': /* args */
4197 goto make_one_char_var;
4199 bool first_char, all_digits;
4201 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4202 ch = i_getch(input);
4204 if (as_string) o_addchr(as_string, ch);
4206 /* XXX maybe someone will try to escape the '}' */
4211 ch = i_getch(input);
4213 if (as_string) o_addchr(as_string, ch);
4220 /* ${#var}: length of var contents */
4222 else if (isdigit(ch)) {
4229 && ( (all_digits && !isdigit(ch))
4230 || (!all_digits && !isalnum(ch) && ch != '_')
4233 /* handle parameter expansions
4234 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4239 case ':': /* null modifier */
4240 if (expansion == 0) {
4241 debug_printf_parse(": null modifier\n");
4246 #if 0 /* not implemented yet :( */
4247 case '#': /* remove prefix */
4248 case '%': /* remove suffix */
4249 if (expansion == 0) {
4250 debug_printf_parse(": remove suffix/prefix\n");
4256 case '-': /* default value */
4257 case '=': /* assign default */
4258 case '+': /* alternative */
4259 case '?': /* error indicate */
4260 debug_printf_parse(": parameter expansion\n");
4265 syntax("unterminated ${name}");
4266 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4271 debug_printf_parse(": '%c'\n", ch);
4272 o_addchr(dest, ch | quote_mask);
4276 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4279 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4284 ch = i_getch(input);
4286 if (as_string) o_addchr(as_string, ch);
4288 # if ENABLE_SH_MATH_SUPPORT
4289 if (i_peek(input) == '(') {
4290 ch = i_getch(input);
4292 if (as_string) o_addchr(as_string, ch);
4294 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4295 o_addchr(dest, /*quote_mask |*/ '+');
4299 add_till_closing_paren(dest, input, true);
4302 o_addstr(as_string, dest->data + pos);
4303 o_addchr(as_string, ')');
4304 o_addchr(as_string, ')');
4307 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4311 # if ENABLE_HUSH_TICK
4312 //int pos = dest->length;
4313 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4314 o_addchr(dest, quote_mask | '`');
4318 add_till_closing_paren(dest, input, false);
4321 o_addstr(as_string, dest->data + pos);
4322 o_addchr(as_string, '`');
4325 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4326 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4332 ch = i_getch(input);
4334 if (as_string) o_addchr(as_string, ch);
4337 if (isalnum(ch)) { /* it's $_name or $_123 */
4343 /* $_ Shell or shell script name; or last cmd name */
4344 /* $- Option flags set by set builtin or shell options (-i etc) */
4346 o_addQchr(dest, '$');
4348 debug_printf_parse("handle_dollar return 0\n");
4353 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4354 parse_stream_dquoted(dest, input, dquote_end)
4356 static int parse_stream_dquoted(o_string *as_string,
4358 struct in_str *input,
4365 ch = i_getch(input);
4367 if (as_string && ch != EOF)
4368 o_addchr(as_string, ch);
4370 if (ch == dquote_end) { /* may be only '"' or EOF */
4372 if (dest->o_assignment == NOT_ASSIGNMENT)
4373 dest->o_escape ^= 1;
4374 debug_printf_parse("parse_stream_dquoted return 0\n");
4378 syntax("unterminated \"");
4379 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4384 next = i_peek(input);
4386 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4387 ch, ch, dest->o_escape);
4391 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4395 * "The backslash retains its special meaning [in "..."]
4396 * only when followed by one of the following characters:
4397 * $, `, ", \, or <newline>. A double quote may be quoted
4398 * within double quotes by preceding it with a backslash.
4399 * If enabled, history expansion will be performed unless
4400 * an ! appearing in double quotes is escaped using
4401 * a backslash. The backslash preceding the ! is not removed."
4403 if (strchr("$`\"\\", next) != NULL) {
4404 o_addqchr(dest, i_getch(input));
4406 o_addqchr(dest, '\\');
4411 if (handle_dollar(as_string, dest, input) != 0) {
4412 debug_printf_parse("parse_stream_dquoted return 1: "
4413 "handle_dollar returned non-0\n");
4418 #if ENABLE_HUSH_TICK
4420 //int pos = dest->length;
4421 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4422 o_addchr(dest, 0x80 | '`');
4423 add_till_backquote(dest, input);
4424 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4425 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4429 o_addQchr(dest, ch);
4431 && (dest->o_assignment == MAYBE_ASSIGNMENT
4432 || dest->o_assignment == WORD_IS_KEYWORD)
4433 && is_assignment(dest->data)
4435 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4441 * Scan input until EOF or end_trigger char.
4442 * Return a list of pipes to execute, or NULL on EOF
4443 * or if end_trigger character is met.
4444 * On syntax error, exit is shell is not interactive,
4445 * reset parsing machinery and start parsing anew,
4446 * or return ERR_PTR.
4448 static struct pipe *parse_stream(char **pstring,
4449 struct in_str *input,
4452 struct parse_context ctx;
4453 o_string dest = NULL_O_STRING;
4456 /* Double-quote state is handled in the state variable is_in_dquote.
4457 * A single-quote triggers a bypass of the main loop until its mate is
4458 * found. When recursing, quote state is passed in via dest->o_escape.
4460 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4461 end_trigger ? : 'X');
4463 G.ifs = get_local_var_value("IFS");
4468 #if ENABLE_HUSH_INTERACTIVE
4469 input->promptmode = 0; /* PS1 */
4471 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4472 initialize_context(&ctx);
4476 const char *is_special;
4480 redir_type redir_style;
4483 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4486 /* We reached closing '"' */
4489 ch = i_getch(input);
4490 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4491 ch, ch, dest.o_escape);
4494 if (done_word(&dest, &ctx)) {
4498 done_pipe(&ctx, PIPE_SEQ);
4500 /* If we got nothing... */
4501 // TODO: test script consisting of just "&"
4502 if (pi->num_cmds == 0
4503 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4505 free_pipe_list(pi, 0);
4508 debug_printf_parse("parse_stream return %p\n", pi);
4510 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4512 *pstring = ctx.as_string.data;
4514 o_free_unsafe(&ctx.as_string);
4519 o_addchr(&ctx.as_string, ch);
4521 is_ifs = strchr(G.ifs, ch);
4522 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4523 "\\$\"" USE_HUSH_TICK("`") /* always special */
4526 if (!is_special && !is_ifs) { /* ordinary char */
4527 o_addQchr(&dest, ch);
4528 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4529 || dest.o_assignment == WORD_IS_KEYWORD)
4531 && is_assignment(dest.data)
4533 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4539 if (done_word(&dest, &ctx)) {
4543 #if ENABLE_HUSH_CASE
4544 /* "case ... in <newline> word) ..." -
4545 * newlines are ignored (but ';' wouldn't be) */
4546 if (ctx.command->argv == NULL
4547 && ctx.ctx_res_w == RES_MATCH
4552 /* Treat newline as a command separator. */
4553 done_pipe(&ctx, PIPE_SEQ);
4554 dest.o_assignment = MAYBE_ASSIGNMENT;
4556 /* note: if (is_ifs) continue;
4557 * will still trigger for us */
4560 if (end_trigger && end_trigger == ch) {
4561 //TODO: disallow "{ cmd }" without semicolon
4562 if (done_word(&dest, &ctx)) {
4565 done_pipe(&ctx, PIPE_SEQ);
4566 dest.o_assignment = MAYBE_ASSIGNMENT;
4567 /* Do we sit outside of any if's, loops or case's? */
4569 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4571 debug_printf_parse("parse_stream return %p: "
4572 "end_trigger char found\n",
4576 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4578 *pstring = ctx.as_string.data;
4580 o_free_unsafe(&ctx.as_string);
4582 return ctx.list_head;
4588 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4589 /* ch is a special char and thus this word
4590 * cannot be an assignment */
4591 dest.o_assignment = NOT_ASSIGNMENT;
4596 next = i_peek(input);
4601 if (dest.length == 0) {
4604 if (ch == EOF || ch == '\n')
4607 /* note: we do not add it to &ctx.as_string */
4610 //TODO: go back one char?
4611 o_addchr(&ctx.as_string, '\n');
4614 o_addQchr(&dest, ch);
4622 o_addchr(&dest, '\\');
4623 ch = i_getch(input);
4624 o_addchr(&dest, ch);
4626 o_addchr(&ctx.as_string, ch);
4630 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
4631 debug_printf_parse("parse_stream parse error: "
4632 "handle_dollar returned non-0\n");
4639 ch = i_getch(input);
4641 syntax("unterminated '");
4645 o_addchr(&ctx.as_string, ch);
4649 if (dest.o_assignment == NOT_ASSIGNMENT)
4650 o_addqchr(&dest, ch);
4652 o_addchr(&dest, ch);
4657 is_in_dquote ^= 1; /* invert */
4658 if (dest.o_assignment == NOT_ASSIGNMENT)
4661 #if ENABLE_HUSH_TICK
4663 //int pos = dest.length;
4664 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4665 o_addchr(&dest, '`');
4666 add_till_backquote(&dest, input);
4667 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4668 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4673 redir_fd = redirect_opt_num(&dest);
4674 if (done_word(&dest, &ctx)) {
4677 redir_style = REDIRECT_OVERWRITE;
4679 redir_style = REDIRECT_APPEND;
4680 ch = i_getch(input);
4682 o_addchr(&ctx.as_string, ch);
4686 else if (next == '(') {
4687 syntax(">(process) not supported");
4691 setup_redirect(&ctx, redir_fd, redir_style, input);
4694 redir_fd = redirect_opt_num(&dest);
4695 if (done_word(&dest, &ctx)) {
4698 redir_style = REDIRECT_INPUT;
4700 redir_style = REDIRECT_HEREIS;
4701 ch = i_getch(input);
4703 o_addchr(&ctx.as_string, ch);
4705 } else if (next == '>') {
4706 redir_style = REDIRECT_IO;
4707 ch = i_getch(input);
4709 o_addchr(&ctx.as_string, ch);
4713 else if (next == '(') {
4714 syntax("<(process) not supported");
4718 setup_redirect(&ctx, redir_fd, redir_style, input);
4721 #if ENABLE_HUSH_CASE
4724 if (done_word(&dest, &ctx)) {
4727 done_pipe(&ctx, PIPE_SEQ);
4728 #if ENABLE_HUSH_CASE
4729 /* Eat multiple semicolons, detect
4730 * whether it means something special */
4735 ch = i_getch(input);
4737 o_addchr(&ctx.as_string, ch);
4739 if (ctx.ctx_res_w == RES_CASEI) {
4740 ctx.ctx_dsemicolon = 1;
4741 ctx.ctx_res_w = RES_MATCH;
4747 /* We just finished a cmd. New one may start
4748 * with an assignment */
4749 dest.o_assignment = MAYBE_ASSIGNMENT;
4752 if (done_word(&dest, &ctx)) {
4756 ch = i_getch(input);
4758 o_addchr(&ctx.as_string, ch);
4760 done_pipe(&ctx, PIPE_AND);
4762 done_pipe(&ctx, PIPE_BG);
4766 if (done_word(&dest, &ctx)) {
4769 #if ENABLE_HUSH_CASE
4770 if (ctx.ctx_res_w == RES_MATCH)
4771 break; /* we are in case's "word | word)" */
4773 if (next == '|') { /* || */
4774 ch = i_getch(input);
4776 o_addchr(&ctx.as_string, ch);
4778 done_pipe(&ctx, PIPE_OR);
4780 /* we could pick up a file descriptor choice here
4781 * with redirect_opt_num(), but bash doesn't do it.
4782 * "echo foo 2| cat" yields "foo 2". */
4787 #if ENABLE_HUSH_CASE
4788 /* "case... in [(]word)..." - skip '(' */
4789 if (ctx.ctx_res_w == RES_MATCH
4790 && ctx.command->argv == NULL /* not (word|(... */
4791 && dest.length == 0 /* not word(... */
4792 && dest.nonnull == 0 /* not ""(... */
4797 #if ENABLE_HUSH_FUNCTIONS
4798 if (dest.length != 0 /* not just () but word() */
4799 && dest.nonnull == 0 /* not a"b"c() */
4800 && ctx.command->argv == NULL /* it's the first word */
4801 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4802 && i_peek(input) == ')'
4803 && !match_reserved_word(&dest)
4805 bb_error_msg("seems like a function definition");
4807 //if !BB_MMU o_addchr(&ctx.as_string...
4809 //TODO: do it properly.
4810 ch = i_getch(input);
4811 } while (ch == ' ' || ch == '\n');
4813 syntax("was expecting {");
4816 ch = 'F'; /* magic value */
4820 if (parse_group(&dest, &ctx, input, ch) != 0) {
4825 #if ENABLE_HUSH_CASE
4826 if (ctx.ctx_res_w == RES_MATCH)
4830 /* proper use of this character is caught by end_trigger:
4831 * if we see {, we call parse_group(..., end_trigger='}')
4832 * and it will match } earlier (not here). */
4833 syntax("unexpected } or )");
4837 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4843 struct parse_context *pctx;
4844 IF_HAS_KEYWORDS(struct parse_context *p2;)
4846 /* Clean up allocated tree.
4847 * Samples for finding leaks on syntax error recovery path.
4848 * Run them from interactive shell, watch pmap `pidof hush`.
4849 * while if false; then false; fi do break; done
4851 * while if false; then false; fi; do break; fi
4852 * Samples to catch leaks at execution:
4853 * while if (true | {true;}); then echo ok; fi; do break; done
4854 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4858 /* Update pipe/command counts,
4859 * otherwise freeing may miss some */
4860 done_pipe(pctx, PIPE_SEQ);
4861 debug_printf_clean("freeing list %p from ctx %p\n",
4862 pctx->list_head, pctx);
4863 debug_print_tree(pctx->list_head, 0);
4864 free_pipe_list(pctx->list_head, 0);
4865 debug_printf_clean("freed list %p\n", pctx->list_head);
4867 o_free_unsafe(&pctx->as_string);
4869 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4873 IF_HAS_KEYWORDS(pctx = p2;)
4874 } while (HAS_KEYWORDS && pctx);
4875 /* Free text, clear all dest fields */
4877 /* If we are not in top-level parse, we return,
4878 * our caller will propagate error.
4880 if (end_trigger != ';') {
4887 /* Discard cached input, force prompt */
4889 USE_HUSH_INTERACTIVE(input->promptme = 1;)
4894 /* Executing from string: eval, sh -c '...'
4895 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4896 * end_trigger controls how often we stop parsing
4897 * NUL: parse all, execute, return
4898 * ';': parse till ';' or newline, execute, repeat till EOF
4900 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4903 struct pipe *pipe_list;
4905 pipe_list = parse_stream(NULL, inp, end_trigger);
4906 if (!pipe_list) /* EOF */
4908 debug_print_tree(pipe_list, 0);
4909 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4910 run_and_free_list(pipe_list);
4914 static void parse_and_run_string(const char *s)
4916 struct in_str input;
4917 setup_string_in_str(&input, s);
4918 parse_and_run_stream(&input, '\0');
4921 static void parse_and_run_file(FILE *f)
4923 struct in_str input;
4924 setup_file_in_str(&input, f);
4925 parse_and_run_stream(&input, ';');
4928 /* Called a few times only (or even once if "sh -c") */
4929 static void block_signals(int second_time)
4934 mask = (1 << SIGQUIT);
4935 if (G_interactive_fd) {
4941 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
4946 G.non_DFL_mask = mask;
4949 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
4953 sigaddset(&G.blocked_set, sig);
4957 sigdelset(&G.blocked_set, SIGCHLD);
4959 sigprocmask(SIG_SETMASK, &G.blocked_set,
4960 second_time ? NULL : &G.inherited_set);
4961 /* POSIX allows shell to re-enable SIGCHLD
4962 * even if it was SIG_IGN on entry */
4963 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4965 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4970 static void maybe_set_to_sigexit(int sig)
4972 void (*handler)(int);
4973 /* non_DFL_mask'ed signals are, well, masked,
4974 * no need to set handler for them.
4976 if (!((G.non_DFL_mask >> sig) & 1)) {
4977 handler = signal(sig, sigexit);
4978 if (handler == SIG_IGN) /* oops... restore back to IGN! */
4979 signal(sig, handler);
4982 /* Set handlers to restore tty pgrm and exit */
4983 static void set_fatal_handlers(void)
4985 /* We _must_ restore tty pgrp on fatal signals */
4987 maybe_set_to_sigexit(SIGILL );
4988 maybe_set_to_sigexit(SIGFPE );
4989 maybe_set_to_sigexit(SIGBUS );
4990 maybe_set_to_sigexit(SIGSEGV);
4991 maybe_set_to_sigexit(SIGTRAP);
4992 } /* else: hush is perfect. what SEGV? */
4993 maybe_set_to_sigexit(SIGABRT);
4994 /* bash 3.2 seems to handle these just like 'fatal' ones */
4995 maybe_set_to_sigexit(SIGPIPE);
4996 maybe_set_to_sigexit(SIGALRM);
4997 maybe_set_to_sigexit(SIGHUP );
4998 /* if we are interactive, SIGTERM and SIGINT are masked.
4999 * if we aren't interactive... but in this case
5000 * we never want to restore pgrp on exit, and this fn is not called */
5001 /*maybe_set_to_sigexit(SIGTERM);*/
5002 /*maybe_set_to_sigexit(SIGINT );*/
5006 static int set_mode(const char cstate, const char mode)
5008 int state = (cstate == '-' ? 1 : 0);
5010 case 'n': G.fake_mode = state; break;
5011 case 'x': /*G.debug_mode = state;*/ break;
5012 default: return EXIT_FAILURE;
5014 return EXIT_SUCCESS;
5017 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5018 int hush_main(int argc, char **argv)
5020 static const struct variable const_shell_ver = {
5022 .varstr = (char*)hush_version_str,
5023 .max_len = 1, /* 0 can provoke free(name) */
5027 int signal_mask_is_inited = 0;
5030 struct variable *cur_var;
5033 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5034 G.last_return_code = EXIT_SUCCESS;
5036 G.argv0_for_re_execing = argv[0];
5038 /* Deal with HUSH_VERSION */
5039 G.shell_ver = const_shell_ver; /* copying struct here */
5040 G.top_var = &G.shell_ver;
5041 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5042 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5043 /* Initialize our shell local variables with the values
5044 * currently living in the environment */
5045 cur_var = G.top_var;
5048 char *value = strchr(*e, '=');
5049 if (value) { /* paranoia */
5050 cur_var->next = xzalloc(sizeof(*cur_var));
5051 cur_var = cur_var->next;
5052 cur_var->varstr = *e;
5053 cur_var->max_len = strlen(*e);
5054 cur_var->flg_export = 1;
5058 debug_printf_env("putenv '%s'\n", hush_version_str);
5059 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5060 #if ENABLE_FEATURE_EDITING
5061 G.line_input_state = new_line_input_t(FOR_SHELL);
5063 G.global_argc = argc;
5064 G.global_argv = argv;
5065 /* Initialize some more globals to non-zero values */
5067 #if ENABLE_HUSH_INTERACTIVE
5068 if (ENABLE_FEATURE_EDITING)
5069 cmdedit_set_initial_prompt();
5073 /* Shell is non-interactive at first. We need to call
5074 * block_signals(0) if we are going to execute "sh script",
5075 * "sh -c cmds" or login shell's /etc/profile and friends.
5076 * If we later decide that we are interactive, we run block_signals(0)
5077 * (or re-run block_signals(1) if we ran block_signals(0) before)
5078 * in order to intercept (more) signals.
5082 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5084 opt = getopt(argc, argv, "c:xins"
5094 G.root_pid = getpid();
5095 G.global_argv = argv + optind;
5096 if (!argv[optind]) {
5097 /* -c 'script' (no params): prevent empty $0 */
5098 *--G.global_argv = argv[0];
5100 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5101 G.global_argc = argc - optind;
5102 block_signals(0); /* 0: called 1st time */
5103 parse_and_run_string(optarg);
5106 /* Well, we cannot just declare interactiveness,
5107 * we have to have some stuff (ctty, etc) */
5108 /* G_interactive_fd++; */
5111 /* "-s" means "read from stdin", but this is how we always
5112 * operate, so simply do nothing here. */
5116 G.root_pid = xatoi_u(optarg);
5119 G.last_bg_pid = xatoi_u(optarg);
5122 G.last_return_code = xatoi_u(optarg);
5124 #if ENABLE_HUSH_LOOPS
5126 G.depth_of_loop = xatoi_u(optarg);
5131 set_local_var(xstrdup(optarg), 0, opt == 'R');
5136 if (!set_mode('-', opt))
5140 fprintf(stderr, "Usage: sh [FILE]...\n"
5141 " or: sh -c command [args]...\n\n");
5147 } /* option parsing loop */
5150 G.root_pid = getpid();
5152 /* If we are login shell... */
5153 if (argv[0] && argv[0][0] == '-') {
5155 /* XXX what should argv be while sourcing /etc/profile? */
5156 debug_printf("sourcing /etc/profile\n");
5157 input = fopen_for_read("/etc/profile");
5158 if (input != NULL) {
5159 close_on_exec_on(fileno(input));
5160 block_signals(0); /* 0: called 1st time */
5161 signal_mask_is_inited = 1;
5162 parse_and_run_file(input);
5165 /* bash: after sourcing /etc/profile,
5166 * tries to source (in the given order):
5167 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5168 * stopping of first found. --noprofile turns this off.
5169 * bash also sources ~/.bash_logout on exit.
5170 * If called as sh, skips .bash_XXX files.
5177 * Non-interactive "bash <script>" sources $BASH_ENV here
5178 * (without scanning $PATH).
5179 * If called as sh, does the same but with $ENV.
5181 debug_printf("running script '%s'\n", argv[optind]);
5182 G.global_argv = argv + optind;
5183 G.global_argc = argc - optind;
5184 input = xfopen_for_read(argv[optind]);
5185 close_on_exec_on(fileno(input));
5186 if (!signal_mask_is_inited)
5187 block_signals(0); /* 0: called 1st time */
5188 parse_and_run_file(input);
5189 #if ENABLE_FEATURE_CLEAN_UP
5195 /* Up to here, shell was non-interactive. Now it may become one.
5196 * NB: don't forget to (re)run block_signals(0/1) as needed.
5199 /* A shell is interactive if the '-i' flag was given, or if all of
5200 * the following conditions are met:
5202 * no arguments remaining or the -s flag given
5203 * standard input is a terminal
5204 * standard output is a terminal
5205 * Refer to Posix.2, the description of the 'sh' utility.
5208 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5209 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5210 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5211 if (G.saved_tty_pgrp >= 0) {
5212 /* try to dup stdin to high fd#, >= 255 */
5213 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5214 if (G_interactive_fd < 0) {
5215 /* try to dup to any fd */
5216 G_interactive_fd = dup(STDIN_FILENO);
5217 if (G_interactive_fd < 0)
5219 G_interactive_fd = 0;
5221 // TODO: track & disallow any attempts of user
5222 // to (inadvertently) close/redirect it
5225 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5226 if (G_interactive_fd) {
5229 /* We are indeed interactive shell, and we will perform
5230 * job control. Setting up for that. */
5232 close_on_exec_on(G_interactive_fd);
5233 /* If we were run as 'hush &', sleep until we are
5234 * in the foreground (tty pgrp == our pgrp).
5235 * If we get started under a job aware app (like bash),
5236 * make sure we are now in charge so we don't fight over
5237 * who gets the foreground */
5239 shell_pgrp = getpgrp();
5240 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5241 if (G.saved_tty_pgrp == shell_pgrp)
5243 /* send TTIN to ourself (should stop us) */
5244 kill(- shell_pgrp, SIGTTIN);
5246 /* Block some signals */
5247 block_signals(signal_mask_is_inited);
5248 /* Set other signals to restore saved_tty_pgrp */
5249 set_fatal_handlers();
5250 /* Put ourselves in our own process group */
5251 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5252 /* Grab control of the terminal */
5253 tcsetpgrp(G_interactive_fd, getpid());
5254 /* -1 is special - makes xfuncs longjmp, not exit
5255 * (we reset die_sleep = 0 whereever we [v]fork) */
5257 if (setjmp(die_jmp)) {
5258 /* xfunc has failed! die die die */
5259 hush_exit(xfunc_error_retval);
5261 } else if (!signal_mask_is_inited) {
5262 block_signals(0); /* 0: called 1st time */
5263 } /* else: block_signals(0) was done before */
5264 #elif ENABLE_HUSH_INTERACTIVE
5265 /* No job control compiled in, only prompt/line editing */
5266 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5267 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5268 if (G_interactive_fd < 0) {
5269 /* try to dup to any fd */
5270 G_interactive_fd = dup(STDIN_FILENO);
5271 if (G_interactive_fd < 0)
5273 G_interactive_fd = 0;
5276 if (G_interactive_fd) {
5277 close_on_exec_on(G_interactive_fd);
5278 block_signals(signal_mask_is_inited);
5279 } else if (!signal_mask_is_inited) {
5283 /* We have interactiveness code disabled */
5284 if (!signal_mask_is_inited) {
5289 * if interactive but not a login shell, sources ~/.bashrc
5290 * (--norc turns this off, --rcfile <file> overrides)
5293 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5294 printf("\n\n%s hush - the humble shell\n", bb_banner);
5295 printf("Enter 'help' for a list of built-in commands.\n\n");
5298 parse_and_run_file(stdin);
5301 #if ENABLE_FEATURE_CLEAN_UP
5302 if (G.cwd != bb_msg_unknown)
5304 cur_var = G.top_var->next;
5306 struct variable *tmp = cur_var;
5307 if (!cur_var->max_len)
5308 free(cur_var->varstr);
5309 cur_var = cur_var->next;
5313 hush_exit(G.last_return_code);
5318 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5319 int lash_main(int argc, char **argv)
5321 //bb_error_msg("lash is deprecated, please use hush instead");
5322 return hush_main(argc, argv);
5330 static int builtin_trap(char **argv)
5337 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5340 /* No args: print all trapped. This isn't 100% correct as we should
5341 * be escaping the cmd so that it can be pasted back in ...
5343 for (i = 0; i < NSIG; ++i)
5345 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5346 return EXIT_SUCCESS;
5351 /* if first arg is decimal: reset all specified */
5352 sig = bb_strtou(*++argv, NULL, 10);
5358 sig = get_signum(*argv++);
5359 if (sig < 0 || sig >= NSIG) {
5361 /* mimic bash message exactly */
5362 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5367 G.traps[sig] = xstrdup(new_cmd);
5369 debug_printf("trap: setting SIG%s (%i) to '%s'",
5370 get_signame(sig), sig, G.traps[sig]);
5372 /* There is no signal for 0 (EXIT) */
5377 sigaddset(&G.blocked_set, sig);
5379 /* there was a trap handler, we are removing it
5380 * (if sig has non-DFL handling,
5381 * we don't need to do anything) */
5382 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5384 sigdelset(&G.blocked_set, sig);
5386 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5391 /* first arg is "-": reset all specified to default */
5392 /* first arg is "": ignore all specified */
5393 /* everything else: execute first arg upon signal */
5395 bb_error_msg("trap: invalid arguments");
5396 return EXIT_FAILURE;
5398 if (LONE_DASH(*argv))
5406 static int builtin_true(char **argv UNUSED_PARAM)
5411 static int builtin_test(char **argv)
5418 return test_main(argc, argv - argc);
5421 static int builtin_echo(char **argv)
5428 return echo_main(argc, argv - argc);
5431 static int builtin_eval(char **argv)
5433 int rcode = EXIT_SUCCESS;
5436 char *str = expand_strvec_to_string(argv + 1);
5438 * eval "echo Hi; done" ("done" is syntax error):
5439 * "echo Hi" will not execute too.
5441 parse_and_run_string(str);
5443 rcode = G.last_return_code;
5448 static int builtin_cd(char **argv)
5451 if (argv[1] == NULL) {
5452 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5453 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5455 newdir = getenv("HOME") ? : "/";
5458 if (chdir(newdir)) {
5459 printf("cd: %s: %s\n", newdir, strerror(errno));
5460 return EXIT_FAILURE;
5463 return EXIT_SUCCESS;
5466 static int builtin_exec(char **argv)
5468 if (argv[1] == NULL)
5469 return EXIT_SUCCESS; /* bash does this */
5474 // FIXME: if exec fails, bash does NOT exit! We do...
5475 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
5480 static int builtin_exit(char **argv)
5482 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5483 //puts("exit"); /* bash does it */
5484 // TODO: warn if we have background jobs: "There are stopped jobs"
5485 // On second consecutive 'exit', exit anyway.
5486 if (argv[1] == NULL)
5487 hush_exit(G.last_return_code);
5488 /* mimic bash: exit 123abc == exit 255 + error msg */
5489 xfunc_error_retval = 255;
5490 /* bash: exit -2 == exit 254, no error msg */
5491 hush_exit(xatoi(argv[1]) & 0xff);
5494 static int builtin_export(char **argv)
5497 char *name = argv[1];
5501 // ash emits: export VAR='VAL'
5502 // bash: declare -x VAR="VAL"
5503 // (both also escape as needed (quotes, $, etc))
5508 return EXIT_SUCCESS;
5511 value = strchr(name, '=');
5513 /* They are exporting something without a =VALUE */
5514 struct variable *var;
5516 var = get_local_var(name);
5518 var->flg_export = 1;
5519 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5520 putenv(var->varstr);
5522 /* bash does not return an error when trying to export
5523 * an undefined variable. Do likewise. */
5524 return EXIT_SUCCESS;
5527 set_local_var(xstrdup(name), 1, 0);
5528 return EXIT_SUCCESS;
5532 /* built-in 'fg' and 'bg' handler */
5533 static int builtin_fg_bg(char **argv)
5538 if (!G_interactive_fd)
5539 return EXIT_FAILURE;
5540 /* If they gave us no args, assume they want the last backgrounded task */
5542 for (pi = G.job_list; pi; pi = pi->next) {
5543 if (pi->jobid == G.last_jobid) {
5547 bb_error_msg("%s: no current job", argv[0]);
5548 return EXIT_FAILURE;
5550 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5551 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5552 return EXIT_FAILURE;
5554 for (pi = G.job_list; pi; pi = pi->next) {
5555 if (pi->jobid == jobnum) {
5559 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5560 return EXIT_FAILURE;
5562 // TODO: bash prints a string representation
5563 // of job being foregrounded (like "sleep 1 | cat")
5564 if (argv[0][0] == 'f') {
5565 /* Put the job into the foreground. */
5566 tcsetpgrp(G_interactive_fd, pi->pgrp);
5569 /* Restart the processes in the job */
5570 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5571 for (i = 0; i < pi->num_cmds; i++) {
5572 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5573 pi->cmds[i].is_stopped = 0;
5575 pi->stopped_cmds = 0;
5577 i = kill(- pi->pgrp, SIGCONT);
5579 if (errno == ESRCH) {
5580 delete_finished_bg_job(pi);
5581 return EXIT_SUCCESS;
5583 bb_perror_msg("kill (SIGCONT)");
5586 if (argv[0][0] == 'f') {
5588 return checkjobs_and_fg_shell(pi);
5590 return EXIT_SUCCESS;
5594 #if ENABLE_HUSH_HELP
5595 static int builtin_help(char **argv UNUSED_PARAM)
5597 const struct built_in_command *x;
5600 "Built-in commands:\n"
5601 "------------------\n");
5602 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5603 printf("%s\t%s\n", x->cmd, x->descr);
5606 return EXIT_SUCCESS;
5611 static int builtin_jobs(char **argv UNUSED_PARAM)
5614 const char *status_string;
5616 for (job = G.job_list; job; job = job->next) {
5617 if (job->alive_cmds == job->stopped_cmds)
5618 status_string = "Stopped";
5620 status_string = "Running";
5622 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5624 return EXIT_SUCCESS;
5628 static int builtin_pwd(char **argv UNUSED_PARAM)
5631 return EXIT_SUCCESS;
5634 static int builtin_read(char **argv)
5637 const char *name = argv[1] ? argv[1] : "REPLY";
5639 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5640 return set_local_var(string, 0, 0);
5643 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5644 * built-in 'set' handler
5646 * set [-abCefhmnuvx] [-o option] [argument...]
5647 * set [+abCefhmnuvx] [+o option] [argument...]
5648 * set -- [argument...]
5651 * Implementations shall support the options in both their hyphen and
5652 * plus-sign forms. These options can also be specified as options to sh.
5654 * Write out all variables and their values: set
5655 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5656 * Turn on the -x and -v options: set -xv
5657 * Unset all positional parameters: set --
5658 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5659 * Set the positional parameters to the expansion of x, even if x expands
5660 * with a leading '-' or '+': set -- $x
5662 * So far, we only support "set -- [argument...]" and some of the short names.
5664 static int builtin_set(char **argv)
5667 char **pp, **g_argv;
5668 char *arg = *++argv;
5672 for (e = G.top_var; e; e = e->next)
5674 return EXIT_SUCCESS;
5678 if (!strcmp(arg, "--")) {
5683 if (arg[0] == '+' || arg[0] == '-') {
5684 for (n = 1; arg[n]; ++n)
5685 if (set_mode(arg[0], arg[n]))
5691 } while ((arg = *++argv) != NULL);
5692 /* Now argv[0] is 1st argument */
5694 /* Only reset global_argv if we didn't process anything */
5696 return EXIT_SUCCESS;
5699 /* NB: G.global_argv[0] ($0) is never freed/changed */
5700 g_argv = G.global_argv;
5701 if (G.global_args_malloced) {
5707 G.global_args_malloced = 1;
5708 pp = xzalloc(sizeof(pp[0]) * 2);
5709 pp[0] = g_argv[0]; /* retain $0 */
5712 /* This realloc's G.global_argv */
5713 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5720 return EXIT_SUCCESS;
5722 /* Nothing known, so abort */
5724 bb_error_msg("set: %s: invalid option", arg);
5725 return EXIT_FAILURE;
5728 static int builtin_shift(char **argv)
5734 if (n >= 0 && n < G.global_argc) {
5735 if (G.global_args_malloced) {
5738 free(G.global_argv[m++]);
5741 memmove(&G.global_argv[1], &G.global_argv[n+1],
5742 G.global_argc * sizeof(G.global_argv[0]));
5743 return EXIT_SUCCESS;
5745 return EXIT_FAILURE;
5748 static int builtin_source(char **argv)
5752 if (argv[1] == NULL)
5753 return EXIT_FAILURE;
5755 /* XXX search through $PATH is missing */
5756 input = fopen_for_read(argv[1]);
5758 bb_error_msg("can't open '%s'", argv[1]);
5759 return EXIT_FAILURE;
5761 close_on_exec_on(fileno(input));
5763 /* Now run the file */
5764 /* XXX argv and argc are broken; need to save old G.global_argv
5765 * (pointer only is OK!) on this stack frame,
5766 * set G.global_argv=argv+1, recurse, and restore. */
5767 parse_and_run_file(input);
5769 return G.last_return_code;
5772 static int builtin_umask(char **argv)
5775 const char *arg = argv[1];
5777 new_umask = bb_strtou(arg, NULL, 8);
5779 return EXIT_FAILURE;
5781 new_umask = umask(0);
5782 printf("%.3o\n", (unsigned) new_umask);
5785 return EXIT_SUCCESS;
5788 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5789 static int builtin_unset(char **argv)
5796 return EXIT_SUCCESS;
5799 if (argv[1][0] == '-') {
5800 switch (argv[1][1]) {
5802 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5804 bb_error_msg("unset: %s: invalid option", argv[1]);
5805 return EXIT_FAILURE;
5813 if (unset_local_var(argv[i]))
5816 #if ENABLE_HUSH_FUNCTIONS
5818 unset_local_func(argv[i]);
5824 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5825 static int builtin_wait(char **argv)
5827 int ret = EXIT_SUCCESS;
5830 if (*++argv == NULL) {
5831 /* Don't care about wait results */
5832 /* Note 1: must wait until there are no more children */
5833 /* Note 2: must be interruptible */
5835 * $ sleep 3 & sleep 6 & wait
5840 * $ sleep 3 & sleep 6 & wait
5844 * ^C <-- after ~4 sec from keyboard
5847 sigaddset(&G.blocked_set, SIGCHLD);
5848 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5851 if (errno == ECHILD)
5853 /* Wait for SIGCHLD or any other signal of interest */
5854 /* sigtimedwait with infinite timeout: */
5855 sig = sigwaitinfo(&G.blocked_set, NULL);
5857 sig = check_and_run_traps(sig);
5858 if (sig && sig != SIGCHLD) { /* see note 2 */
5864 sigdelset(&G.blocked_set, SIGCHLD);
5865 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5869 /* This is probably buggy wrt interruptible-ness */
5871 pid_t pid = bb_strtou(*argv, NULL, 10);
5873 /* mimic bash message */
5874 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5875 return EXIT_FAILURE;
5877 if (waitpid(pid, &status, 0) == pid) {
5878 if (WIFSIGNALED(status))
5879 ret = 128 + WTERMSIG(status);
5880 else if (WIFEXITED(status))
5881 ret = WEXITSTATUS(status);
5885 bb_perror_msg("wait %s", *argv);
5894 #if ENABLE_HUSH_LOOPS
5895 static int builtin_break(char **argv)
5897 if (G.depth_of_loop == 0) {
5898 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5899 return EXIT_SUCCESS; /* bash compat */
5901 G.flag_break_continue++; /* BC_BREAK = 1 */
5902 G.depth_break_continue = 1;
5904 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5905 if (errno || !G.depth_break_continue || argv[2]) {
5906 bb_error_msg("%s: bad arguments", argv[0]);
5907 G.flag_break_continue = BC_BREAK;
5908 G.depth_break_continue = UINT_MAX;
5911 if (G.depth_of_loop < G.depth_break_continue)
5912 G.depth_break_continue = G.depth_of_loop;
5913 return EXIT_SUCCESS;
5916 static int builtin_continue(char **argv)
5918 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5919 return builtin_break(argv);