1 /* vi: set sw=4 ts=4: */
3 * sh.c -- 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 * Bash grammar not implemented: (how many of these were in original sh?)
41 * &> and >& redirection of stdout+stderr
44 * fancy forms of Parameter Expansion
46 * Arithmetic Expansion
47 * <(list) and >(list) Process Substitution
48 * reserved words: case, esac, select, function
49 * Here Documents ( << word )
52 * job handling woefully incomplete and buggy (improved --vda)
53 * reserved word execution woefully incomplete and buggy
55 * port selected bugfixes from post-0.49 busybox lash - done?
56 * change { and } from special chars to reserved words
57 * builtins: break, continue, eval, return, set, trap, ulimit
59 * check setting of global_argc and global_argv
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?
64 * memory leak finding and plugging - done?
65 * maybe change charmap[] to use 2-bit entries
67 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
71 #include <glob.h> /* glob, of course */
72 /* #include <dmalloc.h> */
74 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
77 #if !BB_MMU && ENABLE_HUSH_TICK
78 //#undef ENABLE_HUSH_TICK
79 //#define ENABLE_HUSH_TICK 0
80 #warning On NOMMU, hush command substitution is dangerous.
81 #warning Dont use it for commands which produce lots of output.
82 #warning For more info see shell/hush.c, generate_stream_from_list().
85 #if !BB_MMU && ENABLE_HUSH_JOB
86 #undef ENABLE_HUSH_JOB
87 #define ENABLE_HUSH_JOB 0
90 #if !ENABLE_HUSH_INTERACTIVE
91 #undef ENABLE_FEATURE_EDITING
92 #define ENABLE_FEATURE_EDITING 0
93 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
94 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
98 /* If you comment out one of these below, it will be #defined later
99 * to perform debug printfs to stderr: */
100 #define debug_printf(...) do {} while (0)
101 /* Finer-grained debug switches */
102 #define debug_printf_parse(...) do {} while (0)
103 #define debug_print_tree(a, b) do {} while (0)
104 #define debug_printf_exec(...) do {} while (0)
105 #define debug_printf_jobs(...) do {} while (0)
106 #define debug_printf_expand(...) do {} while (0)
107 #define debug_printf_glob(...) do {} while (0)
108 #define debug_printf_list(...) do {} while (0)
109 #define debug_printf_subst(...) do {} while (0)
110 #define debug_printf_clean(...) do {} while (0)
113 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
116 #ifndef debug_printf_parse
117 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
120 #ifndef debug_printf_exec
121 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
124 #ifndef debug_printf_jobs
125 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
131 #ifndef debug_printf_expand
132 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
133 #define DEBUG_EXPAND 1
135 #define DEBUG_EXPAND 0
138 #ifndef debug_printf_glob
139 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
145 #ifndef debug_printf_list
146 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_subst
150 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_clean
154 /* broken, of course, but OK for testing */
155 static const char *indenter(int i)
157 static const char blanks[] ALIGN1 =
159 return &blanks[sizeof(blanks) - i - 1];
161 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
162 #define DEBUG_CLEAN 1
166 static void debug_print_strings(const char *prefix, char **vv)
168 fprintf(stderr, "%s:\n", prefix);
170 fprintf(stderr, " '%s'\n", *vv++);
173 #define debug_print_strings(prefix, vv) ((void)0)
177 * Leak hunting. Use hush_leaktool.sh for post-processing.
179 #ifdef FOR_HUSH_LEAKTOOL
180 /* suppress "warning: no previous prototype..." */
181 void *xxmalloc(int lineno, size_t size);
182 void *xxrealloc(int lineno, void *ptr, size_t size);
183 char *xxstrdup(int lineno, const char *str);
184 void xxfree(void *ptr);
185 void *xxmalloc(int lineno, size_t size)
187 void *ptr = xmalloc((size + 0xff) & ~0xff);
188 fprintf(stderr, "line %d: malloc %p\n", lineno, ptr);
191 void *xxrealloc(int lineno, void *ptr, size_t size)
193 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
194 fprintf(stderr, "line %d: realloc %p\n", lineno, ptr);
197 char *xxstrdup(int lineno, const char *str)
199 char *ptr = xstrdup(str);
200 fprintf(stderr, "line %d: strdup %p\n", lineno, ptr);
203 void xxfree(void *ptr)
205 fprintf(stderr, "free %p\n", ptr);
208 #define xmalloc(s) xxmalloc(__LINE__, s)
209 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
210 #define xstrdup(s) xxstrdup(__LINE__, s)
211 #define free(p) xxfree(p)
215 /* Keep unconditionally on for now */
217 /* Do we support ANY keywords? */
218 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS
219 #define HAS_KEYWORDS 1
220 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
221 #define IF_HAS_NO_KEYWORDS(...)
223 #define HAS_KEYWORDS 0
224 #define IF_HAS_KEYWORDS(...)
225 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
229 #define SPECIAL_VAR_SYMBOL 3
230 #define PARSEFLAG_EXIT_FROM_LOOP 1
234 REDIRECT_OVERWRITE = 2,
240 /* The descrip member of this structure is only used to make
241 * debugging output pretty */
242 static const struct {
244 signed char default_fd;
248 { O_RDONLY, 0, "<" },
249 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
250 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
251 { O_RDONLY, -1, "<<" },
271 #if ENABLE_HUSH_LOOPS
283 /* This holds pointers to the various results of parsing */
285 struct child_prog *child;
286 struct pipe *list_head;
288 struct redir_struct *pending_redirect;
291 smallint ctx_inverted; /* "! cmd | cmd" */
292 int old_flag; /* bitmask of FLAG_xxx, for figuring out valid reserved words */
293 struct p_context *stack;
297 struct redir_struct {
298 struct redir_struct *next;
299 char *rd_filename; /* filename */
300 int fd; /* file descriptor being redirected */
301 int dup; /* -1, or file descriptor being duplicated */
302 smallint /*enum redir_type*/ rd_type;
306 pid_t pid; /* 0 if exited */
307 smallint is_stopped; /* is the program currently running? */
308 smallint subshell; /* flag, non-zero if group must be forked */
309 char **argv; /* program name and arguments */
310 struct pipe *group; /* if non-NULL, first in group or subshell */
311 struct redir_struct *redirects; /* I/O redirections */
312 struct pipe *family; /* pointer back to the child's parent pipe */
314 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
315 * and on execution these are substituted with their values.
316 * Substitution can make _several_ words out of one argv[n]!
317 * Example: argv[0]=='.^C*^C.' here: echo .$*.
318 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
323 int num_progs; /* total number of programs in job */
324 int alive_progs; /* number of programs running (not exited) */
325 int stopped_progs; /* number of programs alive, but stopped */
327 int jobid; /* job number */
328 pid_t pgrp; /* process group ID for the job */
329 char *cmdtext; /* name of job */
331 struct child_prog *progs; /* array of commands in pipe */
332 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
333 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
334 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
337 /* On program start, environ points to initial environment.
338 * putenv adds new pointers into it, unsetenv removes them.
339 * Neither of these (de)allocates the strings.
340 * setenv allocates new strings in malloc space and does putenv,
341 * and thus setenv is unusable (leaky) for shell's purposes */
342 #define setenv(...) setenv_is_leaky_dont_use()
344 struct variable *next;
345 char *varstr; /* points to "name=" portion */
346 int max_len; /* if > 0, name is part of initial env; else name is malloced */
347 smallint flg_export; /* putenv should be done on this var */
348 smallint flg_read_only;
355 /* Misnomer! it's not "quoting", it's "protection against globbing"!
356 * (by prepending \ to *, ?, [ and to \ too) */
360 smallint has_empty_slot;
361 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
364 MAYBE_ASSIGNMENT = 0,
365 DEFINITELY_ASSIGNMENT = 1,
368 /* Used for initialization: o_string foo = NULL_O_STRING; */
369 #define NULL_O_STRING { NULL }
371 /* I can almost use ordinary FILE *. Is open_memstream() universally
372 * available? Where is it documented? */
375 /* eof_flag=1: last char in ->p is really an EOF */
376 char eof_flag; /* meaningless if ->p == NULL */
378 #if ENABLE_HUSH_INTERACTIVE
380 smallint promptmode; /* 0: PS1, 1: PS2 */
383 int (*get) (struct in_str *);
384 int (*peek) (struct in_str *);
386 #define i_getch(input) ((input)->get(input))
387 #define i_peek(input) ((input)->peek(input))
391 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
392 CHAR_IFS = 2, /* treated as ordinary if quoted */
393 CHAR_SPECIAL = 3, /* example: $ */
396 #define HUSH_VER_STR "0.02"
398 /* "Globals" within this file */
400 /* Sorted roughly by size (smaller offsets == smaller code) */
402 #if ENABLE_HUSH_INTERACTIVE
403 /* 'interactive_fd' is a fd# open to ctty, if we have one
404 * _AND_ if we decided to act interactively */
409 #if ENABLE_FEATURE_EDITING
410 line_input_t *line_input_state;
415 pid_t saved_task_pgrp;
416 pid_t saved_tty_pgrp;
418 struct pipe *job_list;
419 struct pipe *toplevel_list;
420 smallint ctrl_z_flag;
423 /* these three support $?, $#, and $1 */
426 int last_return_code;
429 unsigned last_bg_pid;
430 struct variable *top_var; /* = &shell_ver (set in main()) */
431 struct variable shell_ver;
432 #if ENABLE_FEATURE_SH_STANDALONE
433 struct nofork_save_area nofork_save;
436 sigjmp_buf toplevel_jb;
438 unsigned char charmap[256];
439 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
442 #define G (*ptr_to_globals)
444 #if !ENABLE_HUSH_INTERACTIVE
445 enum { interactive_fd = 0 };
448 enum { run_list_level = 0 };
451 #if ENABLE_HUSH_INTERACTIVE
452 #define interactive_fd (G.interactive_fd )
456 #if ENABLE_FEATURE_EDITING
457 #define line_input_state (G.line_input_state)
459 #define root_pid (G.root_pid )
461 #define run_list_level (G.run_list_level )
462 #define saved_task_pgrp (G.saved_task_pgrp )
463 #define saved_tty_pgrp (G.saved_tty_pgrp )
464 #define last_jobid (G.last_jobid )
465 #define job_list (G.job_list )
466 #define toplevel_list (G.toplevel_list )
467 #define toplevel_jb (G.toplevel_jb )
468 #define ctrl_z_flag (G.ctrl_z_flag )
470 #define global_argv (G.global_argv )
471 #define global_argc (G.global_argc )
472 #define last_return_code (G.last_return_code)
474 #define fake_mode (G.fake_mode )
476 #define last_bg_pid (G.last_bg_pid )
477 #define top_var (G.top_var )
478 #define shell_ver (G.shell_ver )
479 #if ENABLE_FEATURE_SH_STANDALONE
480 #define nofork_save (G.nofork_save )
483 #define toplevel_jb (G.toplevel_jb )
485 #define charmap (G.charmap )
486 #define user_input_buf (G.user_input_buf )
487 #define INIT_G() do { \
488 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
492 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
496 static void syntax(const char *msg)
498 /* Was using fancy stuff:
499 * (interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
500 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
501 void FAST_FUNC (*fp)(const char *s, ...);
503 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
504 fp(msg ? "%s: %s" : "syntax error", "syntax error", msg);
509 static void syntax_lineno(int line)
511 void (*fp)(const char *s, ...);
513 fp = (interactive_fd ? bb_error_msg : bb_error_msg_and_die);
514 fp("syntax error hush.c:%d", line);
516 #define syntax(str) syntax_lineno(__LINE__)
519 /* Index of subroutines: */
520 /* in_str manipulations: */
521 static int static_get(struct in_str *i);
522 static int static_peek(struct in_str *i);
523 static int file_get(struct in_str *i);
524 static int file_peek(struct in_str *i);
525 static void setup_file_in_str(struct in_str *i, FILE *f);
526 static void setup_string_in_str(struct in_str *i, const char *s);
527 /* "run" the final data structures: */
528 #if !defined(DEBUG_CLEAN)
529 #define free_pipe_list(head, indent) free_pipe_list(head)
530 #define free_pipe(pi, indent) free_pipe(pi)
532 static int free_pipe_list(struct pipe *head, int indent);
533 static int free_pipe(struct pipe *pi, int indent);
534 /* really run the final data structures: */
535 static int setup_redirects(struct child_prog *prog, int squirrel[]);
536 static int run_list(struct pipe *pi);
538 #define pseudo_exec_argv(ptrs2free, argv) pseudo_exec_argv(argv)
539 #define pseudo_exec(ptrs2free, child) pseudo_exec(child)
541 static void pseudo_exec_argv(char **ptrs2free, char **argv) NORETURN;
542 static void pseudo_exec(char **ptrs2free, struct child_prog *child) NORETURN;
543 static int run_pipe(struct pipe *pi);
544 /* data structure manipulation: */
545 static int setup_redirect(struct p_context *ctx, int fd, redir_type style, struct in_str *input);
546 static void initialize_context(struct p_context *ctx);
547 static int done_word(o_string *dest, struct p_context *ctx);
548 static int done_command(struct p_context *ctx);
549 static void done_pipe(struct p_context *ctx, pipe_style type);
550 /* primary string parsing: */
551 static int redirect_dup_num(struct in_str *input);
552 static int redirect_opt_num(o_string *o);
554 static int process_command_subs(o_string *dest,
555 struct in_str *input, const char *subst_end);
557 static int parse_group(o_string *dest, struct p_context *ctx, struct in_str *input, int ch);
558 static const char *lookup_param(const char *src);
559 static int handle_dollar(o_string *dest,
560 struct in_str *input);
561 static int parse_stream(o_string *dest, struct p_context *ctx, struct in_str *input0, const char *end_trigger);
563 static int parse_and_run_stream(struct in_str *inp, int parse_flag);
564 static int parse_and_run_string(const char *s, int parse_flag);
565 static int parse_and_run_file(FILE *f);
566 /* job management: */
567 static int checkjobs(struct pipe* fg_pipe);
569 static int checkjobs_and_fg_shell(struct pipe* fg_pipe);
570 static void insert_bg_job(struct pipe *pi);
571 static void remove_bg_job(struct pipe *pi);
572 static void delete_finished_bg_job(struct pipe *pi);
574 int checkjobs_and_fg_shell(struct pipe* fg_pipe); /* never called */
576 /* local variable support */
577 static char **expand_strvec_to_strvec(char **argv);
579 static char *expand_strvec_to_string(char **argv);
580 /* used for expansion of right hand of assignments */
581 static char *expand_string_to_string(const char *str);
582 static struct variable *get_local_var(const char *name);
583 static int set_local_var(char *str, int flg_export);
584 static void unset_local_var(const char *name);
587 static int glob_needed(const char *s)
592 if (*s == '*' || *s == '[' || *s == '?')
599 static int is_assignment(const char *s)
601 if (!s || !isalpha(*s))
604 while (isalnum(*s) || *s == '_')
609 /* Replace each \x with x in place, return ptr past NUL. */
610 static char *unbackslash(char *src)
616 if ((*dst++ = *src++) == '\0')
622 static char **add_malloced_strings_to_strings(char **strings, char **add)
643 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
644 v[count1 + count2] = NULL;
647 v[count1 + i] = add[i];
651 static char **add_malloced_string_to_strings(char **strings, char *add)
658 return add_malloced_strings_to_strings(strings, v);
661 static void free_strings(char **strings)
672 #define EXTRA_PTRS 5 /* 1 for NULL, 1 for args, 3 for paranoid reasons */
673 static char **alloc_ptrs(char **argv)
678 return xzalloc((v - argv + EXTRA_PTRS) * sizeof(v[0]));
683 /* Function prototypes for builtins */
684 static int builtin_cd(char **argv);
685 static int builtin_echo(char **argv);
686 static int builtin_eval(char **argv);
687 static int builtin_exec(char **argv);
688 static int builtin_exit(char **argv);
689 static int builtin_export(char **argv);
691 static int builtin_fg_bg(char **argv);
692 static int builtin_jobs(char **argv);
695 static int builtin_help(char **argv);
697 static int builtin_pwd(char **argv);
698 static int builtin_read(char **argv);
699 static int builtin_test(char **argv);
700 static int builtin_true(char **argv);
701 static int builtin_set(char **argv);
702 static int builtin_shift(char **argv);
703 static int builtin_source(char **argv);
704 static int builtin_umask(char **argv);
705 static int builtin_unset(char **argv);
706 //static int builtin_not_written(char **argv);
708 /* Table of built-in functions. They can be forked or not, depending on
709 * context: within pipes, they fork. As simple commands, they do not.
710 * When used in non-forking context, they can change global variables
711 * in the parent shell process. If forked, of course they cannot.
712 * For example, 'unset foo | whatever' will parse and run, but foo will
713 * still be set at the end. */
714 struct built_in_command {
716 int (*function)(char **argv);
719 #define BLTIN(cmd, func, help) { cmd, func, help }
721 #define BLTIN(cmd, func, help) { cmd, func }
725 /* For now, echo and test are unconditionally enabled.
726 * Maybe make it configurable? */
727 static const struct built_in_command bltins[] = {
728 BLTIN("." , builtin_source, "Run commands in a file"),
729 BLTIN(":" , builtin_true, "No-op"),
730 BLTIN("[" , builtin_test, "Test condition"),
731 BLTIN("[[" , builtin_test, "Test condition"),
733 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
735 // BLTIN("break" , builtin_not_written, "Exit for, while or until loop"),
736 BLTIN("cd" , builtin_cd, "Change directory"),
737 // BLTIN("continue", builtin_not_written, "Continue for, while or until loop"),
738 BLTIN("echo" , builtin_echo, "Write strings to stdout"),
739 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
740 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
741 BLTIN("exit" , builtin_exit, "Exit"),
742 BLTIN("export", builtin_export, "Set environment variable"),
744 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
745 BLTIN("jobs" , builtin_jobs, "List active jobs"),
747 BLTIN("pwd" , builtin_pwd, "Print current directory"),
748 BLTIN("read" , builtin_read, "Input environment variable"),
749 // BLTIN("return", builtin_not_written, "Return from a function"),
750 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
751 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
752 // BLTIN("trap" , builtin_not_written, "Trap signals"),
753 BLTIN("test" , builtin_test, "Test condition"),
754 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
755 BLTIN("umask" , builtin_umask, "Set file creation mask"),
756 BLTIN("unset" , builtin_unset, "Unset environment variable"),
758 BLTIN("help" , builtin_help, "List shell built-in commands"),
763 /* Signals are grouped, we handle them in batches */
764 static void set_misc_sighandler(void (*handler)(int))
775 static void set_fatal_sighandler(void (*handler)(int))
784 /* bash 3.2 seems to handle these just like 'fatal' ones */
790 static void set_jobctrl_sighandler(void (*handler)(int))
798 /* SIGCHLD is special and handled separately */
800 static void set_every_sighandler(void (*handler)(int))
802 set_fatal_sighandler(handler);
803 set_jobctrl_sighandler(handler);
804 set_misc_sighandler(handler);
805 signal(SIGCHLD, handler);
808 static void handler_ctrl_c(int sig UNUSED_PARAM)
810 debug_printf_jobs("got sig %d\n", sig);
811 // as usual we can have all kinds of nasty problems with leaked malloc data here
812 siglongjmp(toplevel_jb, 1);
815 static void handler_ctrl_z(int sig UNUSED_PARAM)
819 debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
821 if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
824 if (!pid) { /* child */
826 die_sleep = 0; /* let nofork's xfuncs die */
828 debug_printf_jobs("set pgrp for child %d ok\n", getpid());
829 set_every_sighandler(SIG_DFL);
830 raise(SIGTSTP); /* resend TSTP so that child will be stopped */
831 debug_printf_jobs("returning in child\n");
832 /* return to nofork, it will eventually exit now,
833 * not return back to shell */
837 /* finish filling up pipe info */
838 toplevel_list->pgrp = pid; /* child is in its own pgrp */
839 toplevel_list->progs[0].pid = pid;
840 /* parent needs to longjmp out of running nofork.
841 * we will "return" exitcode 0, with child put in background */
842 // as usual we can have all kinds of nasty problems with leaked malloc data here
843 debug_printf_jobs("siglongjmp in parent\n");
844 siglongjmp(toplevel_jb, 1);
847 /* Restores tty foreground process group, and exits.
848 * May be called as signal handler for fatal signal
849 * (will faithfully resend signal to itself, producing correct exit state)
850 * or called directly with -EXITCODE.
851 * We also call it if xfunc is exiting. */
852 static void sigexit(int sig) NORETURN;
853 static void sigexit(int sig)
855 /* Disable all signals: job control, SIGPIPE, etc. */
856 sigprocmask_allsigs(SIG_BLOCK);
859 tcsetpgrp(interactive_fd, saved_tty_pgrp);
861 /* Not a signal, just exit */
865 kill_myself_with_sig(sig); /* does not return */
868 /* Restores tty foreground process group, and exits. */
869 static void hush_exit(int exitcode) NORETURN;
870 static void hush_exit(int exitcode)
872 fflush(NULL); /* flush all streams */
873 sigexit(- (exitcode & 0xff));
878 #define set_fatal_sighandler(handler) ((void)0)
879 #define set_jobctrl_sighandler(handler) ((void)0)
880 #define hush_exit(e) exit(e)
885 static const char *set_cwd(void)
887 if (cwd == bb_msg_unknown)
888 cwd = NULL; /* xrealloc_getcwd_or_warn(arg) calls free(arg)! */
889 cwd = xrealloc_getcwd_or_warn((char *)cwd);
891 cwd = bb_msg_unknown;
899 #define B_CHUNK (32 * sizeof(char*))
901 static void o_reset(o_string *o)
909 static void o_free(o_string *o)
912 memset(o, 0, sizeof(*o));
915 static void o_grow_by(o_string *o, int len)
917 if (o->length + len > o->maxlen) {
918 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
919 o->data = xrealloc(o->data, 1 + o->maxlen);
923 static void o_addchr(o_string *o, int ch)
925 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
927 o->data[o->length] = ch;
929 o->data[o->length] = '\0';
932 static void o_addstr(o_string *o, const char *str, int len)
935 memcpy(&o->data[o->length], str, len);
937 o->data[o->length] = '\0';
940 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
945 && (*str != '*' && *str != '?' && *str != '[')
953 /* My analysis of quoting semantics tells me that state information
954 * is associated with a destination, not a source.
956 static void o_addqchr(o_string *o, int ch)
959 if (strchr("*?[\\", ch)) {
961 o->data[o->length] = '\\';
965 o->data[o->length] = ch;
967 o->data[o->length] = '\0';
970 static void o_addQchr(o_string *o, int ch)
973 if (o->o_quote && strchr("*?[\\", ch)) {
975 o->data[o->length] = '\\';
979 o->data[o->length] = ch;
981 o->data[o->length] = '\0';
984 static void o_addQstr(o_string *o, const char *str, int len)
987 o_addstr(o, str, len);
993 int ordinary_cnt = strcspn(str, "*?[\\");
994 if (ordinary_cnt > len) /* paranoia */
996 o_addstr(o, str, ordinary_cnt);
997 if (ordinary_cnt == len)
1000 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1004 if (ch) { /* it is necessarily one of "*?[\\" */
1006 o->data[o->length] = '\\';
1010 o->data[o->length] = ch;
1012 o->data[o->length] = '\0';
1016 /* A special kind of o_string for $VAR and `cmd` expansion.
1017 * It contains char* list[] at the beginning, which is grown in 16 element
1018 * increments. Actual string data starts at the next multiple of 16 * (char*).
1019 * list[i] contains an INDEX (int!) into this string data.
1020 * It means that if list[] needs to grow, data needs to be moved higher up
1021 * but list[i]'s need not be modified.
1022 * NB: remembering how many list[i]'s you have there is crucial.
1023 * o_finalize_list() operation post-processes this structure - calculates
1024 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1026 #if DEBUG_EXPAND || DEBUG_GLOB
1027 static void debug_print_list(const char *prefix, o_string *o, int n)
1029 char **list = (char**)o->data;
1030 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1032 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1033 prefix, list, n, string_start, o->length, o->maxlen);
1035 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1036 o->data + (int)list[i] + string_start,
1037 o->data + (int)list[i] + string_start);
1041 const char *p = o->data + (int)list[n - 1] + string_start;
1042 fprintf(stderr, " total_sz:%d\n", (p + strlen(p) + 1) - o->data);
1046 #define debug_print_list(prefix, o, n) ((void)0)
1049 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1050 * in list[n] so that it points past last stored byte so far.
1051 * It returns n+1. */
1052 static int o_save_ptr_helper(o_string *o, int n)
1054 char **list = (char**)o->data;
1058 if (!o->has_empty_slot) {
1059 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1060 string_len = o->length - string_start;
1061 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1062 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1063 /* list[n] points to string_start, make space for 16 more pointers */
1064 o->maxlen += 0x10 * sizeof(list[0]);
1065 o->data = xrealloc(o->data, o->maxlen + 1);
1066 list = (char**)o->data;
1067 memmove(list + n + 0x10, list + n, string_len);
1068 o->length += 0x10 * sizeof(list[0]);
1070 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1072 /* We have empty slot at list[n], reuse without growth */
1073 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1074 string_len = o->length - string_start;
1075 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1076 o->has_empty_slot = 0;
1078 list[n] = (char*)(ptrdiff_t)string_len;
1082 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1083 static int o_get_last_ptr(o_string *o, int n)
1085 char **list = (char**)o->data;
1086 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1088 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1091 /* o_glob performs globbing on last list[], saving each result
1092 * as a new list[]. */
1093 static int o_glob(o_string *o, int n)
1099 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1101 return o_save_ptr_helper(o, n);
1102 pattern = o->data + o_get_last_ptr(o, n);
1103 debug_printf_glob("glob pattern '%s'\n", pattern);
1104 if (!glob_needed(pattern)) {
1106 o->length = unbackslash(pattern) - o->data;
1107 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1108 return o_save_ptr_helper(o, n);
1111 memset(&globdata, 0, sizeof(globdata));
1112 gr = glob(pattern, 0, NULL, &globdata);
1113 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1114 if (gr == GLOB_NOSPACE)
1115 bb_error_msg_and_die("out of memory during glob");
1116 if (gr == GLOB_NOMATCH) {
1117 globfree(&globdata);
1120 if (gr != 0) { /* GLOB_ABORTED ? */
1121 //TODO: testcase for bad glob pattern behavior
1122 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1124 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1125 char **argv = globdata.gl_pathv;
1126 o->length = pattern - o->data; /* "forget" pattern */
1128 o_addstr(o, *argv, strlen(*argv) + 1);
1129 n = o_save_ptr_helper(o, n);
1135 globfree(&globdata);
1137 debug_print_list("o_glob returning", o, n);
1141 /* If o->o_glob == 1, glob the string so far remembered.
1142 * Otherwise, just finish current list[] and start new */
1143 static int o_save_ptr(o_string *o, int n)
1146 return o_glob(o, n); /* o_save_ptr_helper is inside */
1147 return o_save_ptr_helper(o, n);
1150 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1151 static char **o_finalize_list(o_string *o, int n)
1156 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1158 debug_print_list("finalized", o, n);
1159 debug_printf_expand("finalized n:%d\n", n);
1160 list = (char**)o->data;
1161 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1165 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1174 static int static_get(struct in_str *i)
1177 if (ch == '\0') return EOF;
1181 static int static_peek(struct in_str *i)
1186 #if ENABLE_HUSH_INTERACTIVE
1188 #if ENABLE_FEATURE_EDITING
1189 static void cmdedit_set_initial_prompt(void)
1191 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1194 PS1 = getenv("PS1");
1199 #endif /* EDITING */
1201 static const char* setup_prompt_string(int promptmode)
1203 const char *prompt_str;
1204 debug_printf("setup_prompt_string %d ", promptmode);
1205 #if !ENABLE_FEATURE_EDITING_FANCY_PROMPT
1206 /* Set up the prompt */
1207 if (promptmode == 0) { /* PS1 */
1209 PS1 = xasprintf("%s %c ", cwd, (geteuid() != 0) ? '$' : '#');
1215 prompt_str = (promptmode == 0) ? PS1 : PS2;
1217 debug_printf("result '%s'\n", prompt_str);
1221 static void get_user_input(struct in_str *i)
1224 const char *prompt_str;
1226 prompt_str = setup_prompt_string(i->promptmode);
1227 #if ENABLE_FEATURE_EDITING
1228 /* Enable command line editing only while a command line
1229 * is actually being read */
1231 r = read_line_input(prompt_str, user_input_buf, BUFSIZ-1, line_input_state);
1232 } while (r == 0); /* repeat if Ctrl-C */
1233 i->eof_flag = (r < 0);
1234 if (i->eof_flag) { /* EOF/error detected */
1235 user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1236 user_input_buf[1] = '\0';
1239 fputs(prompt_str, stdout);
1241 user_input_buf[0] = r = fgetc(i->file);
1242 /*user_input_buf[1] = '\0'; - already is and never changed */
1243 i->eof_flag = (r == EOF);
1245 i->p = user_input_buf;
1248 #endif /* INTERACTIVE */
1250 /* This is the magic location that prints prompts
1251 * and gets data back from the user */
1252 static int file_get(struct in_str *i)
1256 /* If there is data waiting, eat it up */
1257 if (i->p && *i->p) {
1258 #if ENABLE_HUSH_INTERACTIVE
1262 if (i->eof_flag && !*i->p)
1265 /* need to double check i->file because we might be doing something
1266 * more complicated by now, like sourcing or substituting. */
1267 #if ENABLE_HUSH_INTERACTIVE
1268 if (interactive_fd && i->promptme && i->file == stdin) {
1271 } while (!*i->p); /* need non-empty line */
1272 i->promptmode = 1; /* PS2 */
1277 ch = fgetc(i->file);
1279 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1280 #if ENABLE_HUSH_INTERACTIVE
1287 /* All the callers guarantee this routine will never be
1288 * used right after a newline, so prompting is not needed.
1290 static int file_peek(struct in_str *i)
1293 if (i->p && *i->p) {
1294 if (i->eof_flag && !i->p[1])
1298 ch = fgetc(i->file);
1299 i->eof_flag = (ch == EOF);
1300 i->peek_buf[0] = ch;
1301 i->peek_buf[1] = '\0';
1303 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1307 static void setup_file_in_str(struct in_str *i, FILE *f)
1309 i->peek = file_peek;
1311 #if ENABLE_HUSH_INTERACTIVE
1313 i->promptmode = 0; /* PS1 */
1319 static void setup_string_in_str(struct in_str *i, const char *s)
1321 i->peek = static_peek;
1322 i->get = static_get;
1323 #if ENABLE_HUSH_INTERACTIVE
1325 i->promptmode = 0; /* PS1 */
1332 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
1333 * and stderr if they are redirected. */
1334 static int setup_redirects(struct child_prog *prog, int squirrel[])
1337 struct redir_struct *redir;
1339 for (redir = prog->redirects; redir; redir = redir->next) {
1340 if (redir->dup == -1 && redir->rd_filename == NULL) {
1341 /* something went wrong in the parse. Pretend it didn't happen */
1344 if (redir->dup == -1) {
1346 mode = redir_table[redir->rd_type].mode;
1347 //TODO: check redir to names like '\\'
1348 p = expand_string_to_string(redir->rd_filename);
1349 openfd = open_or_warn(p, mode);
1352 /* this could get lost if stderr has been redirected, but
1353 bash and ash both lose it as well (though zsh doesn't!) */
1357 openfd = redir->dup;
1360 if (openfd != redir->fd) {
1361 if (squirrel && redir->fd < 3) {
1362 squirrel[redir->fd] = dup(redir->fd);
1365 //close(openfd); // close(-3) ??!
1367 dup2(openfd, redir->fd);
1368 if (redir->dup == -1)
1376 static void restore_redirects(int squirrel[])
1379 for (i = 0; i < 3; i++) {
1382 /* We simply die on error */
1389 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
1391 * XXX no exit() here. If you don't exec, use _exit instead.
1392 * The at_exit handlers apparently confuse the calling process,
1393 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
1394 static void pseudo_exec_argv(char **ptrs2free, char **argv)
1398 const struct built_in_command *x;
1400 for (i = 0; is_assignment(argv[i]); i++) {
1401 debug_printf_exec("pid %d environment modification: %s\n",
1403 p = expand_string_to_string(argv[i]);
1410 /* If a variable is assigned in a forest, and nobody listens,
1411 * was it ever really set?
1414 _exit(EXIT_SUCCESS);
1416 argv = expand_strvec_to_strvec(argv);
1418 *ptrs2free++ = (char*) argv;
1422 * Check if the command matches any of the builtins.
1423 * Depending on context, this might be redundant. But it's
1424 * easier to waste a few CPU cycles than it is to figure out
1425 * if this is one of those cases.
1427 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
1428 if (strcmp(argv[0], x->cmd) == 0) {
1429 debug_printf_exec("running builtin '%s'\n", argv[0]);
1430 rcode = x->function(argv);
1436 /* Check if the command matches any busybox applets */
1437 #if ENABLE_FEATURE_SH_STANDALONE
1438 if (strchr(argv[0], '/') == NULL) {
1439 int a = find_applet_by_name(argv[0]);
1441 if (APPLET_IS_NOEXEC(a)) {
1442 debug_printf_exec("running applet '%s'\n", argv[0]);
1443 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
1444 run_applet_no_and_exit(a, argv);
1446 /* re-exec ourselves with the new arguments */
1447 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
1448 execvp(bb_busybox_exec_path, argv);
1449 /* If they called chroot or otherwise made the binary no longer
1450 * executable, fall through */
1455 debug_printf_exec("execing '%s'\n", argv[0]);
1456 execvp(argv[0], argv);
1457 bb_perror_msg("cannot exec '%s'", argv[0]);
1458 _exit(EXIT_FAILURE);
1461 /* Called after [v]fork() in run_pipe()
1463 static void pseudo_exec(char **ptrs2free, struct child_prog *child)
1466 pseudo_exec_argv(ptrs2free, child->argv);
1470 bb_error_msg_and_die("nested lists are not supported on NOMMU");
1473 debug_printf_exec("pseudo_exec: run_list\n");
1474 rcode = run_list(child->group);
1475 /* OK to leak memory by not calling free_pipe_list,
1476 * since this process is about to exit */
1481 /* Can happen. See what bash does with ">foo" by itself. */
1482 debug_printf("trying to pseudo_exec null command\n");
1483 _exit(EXIT_SUCCESS);
1487 static const char *get_cmdtext(struct pipe *pi)
1493 /* This is subtle. ->cmdtext is created only on first backgrounding.
1494 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
1495 * On subsequent bg argv is trashed, but we won't use it */
1498 argv = pi->progs[0].argv;
1499 if (!argv || !argv[0]) {
1500 pi->cmdtext = xzalloc(1);
1505 do len += strlen(*argv) + 1; while (*++argv);
1506 pi->cmdtext = p = xmalloc(len);
1507 argv = pi->progs[0].argv;
1509 len = strlen(*argv);
1510 memcpy(p, *argv, len);
1518 static void insert_bg_job(struct pipe *pi)
1520 struct pipe *thejob;
1523 /* Linear search for the ID of the job to use */
1525 for (thejob = job_list; thejob; thejob = thejob->next)
1526 if (thejob->jobid >= pi->jobid)
1527 pi->jobid = thejob->jobid + 1;
1529 /* Add thejob to the list of running jobs */
1531 thejob = job_list = xmalloc(sizeof(*thejob));
1533 for (thejob = job_list; thejob->next; thejob = thejob->next)
1535 thejob->next = xmalloc(sizeof(*thejob));
1536 thejob = thejob->next;
1539 /* Physically copy the struct job */
1540 memcpy(thejob, pi, sizeof(struct pipe));
1541 thejob->progs = xzalloc(sizeof(pi->progs[0]) * pi->num_progs);
1542 /* We cannot copy entire pi->progs[] vector! Double free()s will happen */
1543 for (i = 0; i < pi->num_progs; i++) {
1544 // TODO: do we really need to have so many fields which are just dead weight
1545 // at execution stage?
1546 thejob->progs[i].pid = pi->progs[i].pid;
1547 /* all other fields are not used and stay zero */
1549 thejob->next = NULL;
1550 thejob->cmdtext = xstrdup(get_cmdtext(pi));
1552 /* We don't wait for background thejobs to return -- append it
1553 to the list of backgrounded thejobs and leave it alone */
1554 printf("[%d] %d %s\n", thejob->jobid, thejob->progs[0].pid, thejob->cmdtext);
1555 last_bg_pid = thejob->progs[0].pid;
1556 last_jobid = thejob->jobid;
1559 static void remove_bg_job(struct pipe *pi)
1561 struct pipe *prev_pipe;
1563 if (pi == job_list) {
1564 job_list = pi->next;
1566 prev_pipe = job_list;
1567 while (prev_pipe->next != pi)
1568 prev_pipe = prev_pipe->next;
1569 prev_pipe->next = pi->next;
1572 last_jobid = job_list->jobid;
1577 /* Remove a backgrounded job */
1578 static void delete_finished_bg_job(struct pipe *pi)
1581 pi->stopped_progs = 0;
1587 /* Check to see if any processes have exited -- if they
1588 * have, figure out why and see if a job has completed */
1589 static int checkjobs(struct pipe* fg_pipe)
1599 attributes = WUNTRACED;
1600 if (fg_pipe == NULL)
1601 attributes |= WNOHANG;
1603 /* Do we do this right?
1604 * bash-3.00# sleep 20 | false
1606 * [3]+ Stopped sleep 20 | false
1607 * bash-3.00# echo $?
1608 * 1 <========== bg pipe is not fully done, but exitcode is already known!
1611 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
1612 //are stopped. Testcase: "cat | cat" in a script (not on command line)
1613 // + killall -STOP cat
1616 // TODO: safe_waitpid?
1617 while ((childpid = waitpid(-1, &status, attributes)) > 0) {
1619 const int dead = WIFEXITED(status) || WIFSIGNALED(status);
1621 if (WIFSTOPPED(status))
1622 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
1623 childpid, WSTOPSIG(status), WEXITSTATUS(status));
1624 if (WIFSIGNALED(status))
1625 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
1626 childpid, WTERMSIG(status), WEXITSTATUS(status));
1627 if (WIFEXITED(status))
1628 debug_printf_jobs("pid %d exited, exitcode %d\n",
1629 childpid, WEXITSTATUS(status));
1631 /* Were we asked to wait for fg pipe? */
1633 for (i = 0; i < fg_pipe->num_progs; i++) {
1634 debug_printf_jobs("check pid %d\n", fg_pipe->progs[i].pid);
1635 if (fg_pipe->progs[i].pid != childpid)
1637 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
1639 fg_pipe->progs[i].pid = 0;
1640 fg_pipe->alive_progs--;
1641 if (i == fg_pipe->num_progs - 1) {
1642 /* last process gives overall exitstatus */
1643 rcode = WEXITSTATUS(status);
1644 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
1647 fg_pipe->progs[i].is_stopped = 1;
1648 fg_pipe->stopped_progs++;
1650 debug_printf_jobs("fg_pipe: alive_progs %d stopped_progs %d\n",
1651 fg_pipe->alive_progs, fg_pipe->stopped_progs);
1652 if (fg_pipe->alive_progs - fg_pipe->stopped_progs <= 0) {
1653 /* All processes in fg pipe have exited/stopped */
1655 if (fg_pipe->alive_progs)
1656 insert_bg_job(fg_pipe);
1660 /* There are still running processes in the fg pipe */
1661 goto wait_more; /* do waitpid again */
1663 /* it wasnt fg_pipe, look for process in bg pipes */
1667 /* We asked to wait for bg or orphaned children */
1668 /* No need to remember exitcode in this case */
1669 for (pi = job_list; pi; pi = pi->next) {
1670 for (i = 0; i < pi->num_progs; i++) {
1671 if (pi->progs[i].pid == childpid)
1672 goto found_pi_and_prognum;
1675 /* Happens when shell is used as init process (init=/bin/sh) */
1676 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
1677 continue; /* do waitpid again */
1679 found_pi_and_prognum:
1682 pi->progs[i].pid = 0;
1684 if (!pi->alive_progs) {
1685 printf(JOB_STATUS_FORMAT, pi->jobid,
1686 "Done", pi->cmdtext);
1687 delete_finished_bg_job(pi);
1691 pi->progs[i].is_stopped = 1;
1692 pi->stopped_progs++;
1695 } /* while (waitpid succeeds)... */
1697 /* wait found no children or failed */
1699 if (childpid && errno != ECHILD)
1700 bb_perror_msg("waitpid");
1705 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
1708 int rcode = checkjobs(fg_pipe);
1709 /* Job finished, move the shell to the foreground */
1710 p = getpgid(0); /* pgid of our process */
1711 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
1712 tcsetpgrp(interactive_fd, p);
1713 // if (tcsetpgrp(interactive_fd, p) && errno != ENOTTY)
1714 // bb_perror_msg("tcsetpgrp-4a");
1719 /* run_pipe() starts all the jobs, but doesn't wait for anything
1720 * to finish. See checkjobs().
1722 * return code is normally -1, when the caller has to wait for children
1723 * to finish to determine the exit status of the pipe. If the pipe
1724 * is a simple builtin command, however, the action is done by the
1725 * time run_pipe returns, and the exit code is provided as the
1728 * The input of the pipe is always stdin, the output is always
1729 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
1730 * because it tries to avoid running the command substitution in
1731 * subshell, when that is in fact necessary. The subshell process
1732 * now has its stdout directed to the input of the appropriate pipe,
1733 * so this routine is noticeably simpler.
1735 * Returns -1 only if started some children. IOW: we have to
1736 * mask out retvals of builtins etc with 0xff!
1738 static int run_pipe(struct pipe *pi)
1742 int pipefds[2]; /* pipefds[0] is for reading */
1743 struct child_prog *child;
1744 const struct built_in_command *x;
1746 /* it is not always needed, but we aim to smaller code */
1747 int squirrel[] = { -1, -1, -1 };
1749 const int single_fg = (pi->num_progs == 1 && pi->followup != PIPE_BG);
1751 debug_printf_exec("run_pipe start: single_fg=%d\n", single_fg);
1756 pi->alive_progs = 1;
1757 pi->stopped_progs = 0;
1759 /* Check if this is a simple builtin (not part of a pipe).
1760 * Builtins within pipes have to fork anyway, and are handled in
1761 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
1763 child = &(pi->progs[0]);
1764 if (single_fg && child->group && child->subshell == 0) {
1765 debug_printf("non-subshell grouping\n");
1766 setup_redirects(child, squirrel);
1767 debug_printf_exec(": run_list\n");
1768 rcode = run_list(child->group) & 0xff;
1769 restore_redirects(squirrel);
1770 debug_printf_exec("run_pipe return %d\n", rcode);
1771 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
1775 if (single_fg && child->argv != NULL) {
1776 char **argv_expanded;
1777 char **argv = child->argv;
1779 for (i = 0; is_assignment(argv[i]); i++)
1781 if (i != 0 && argv[i] == NULL) {
1782 /* assignments, but no command: set the local environment */
1783 for (i = 0; argv[i] != NULL; i++) {
1784 debug_printf("local environment set: %s\n", argv[i]);
1785 p = expand_string_to_string(argv[i]);
1786 set_local_var(p, 0);
1788 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
1790 for (i = 0; is_assignment(argv[i]); i++) {
1791 p = expand_string_to_string(argv[i]);
1793 //FIXME: do we leak p?!
1795 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
1796 if (strcmp(argv[i], x->cmd) == 0) {
1797 if (x->function == builtin_exec && argv[i+1] == NULL) {
1798 debug_printf("magic exec\n");
1799 setup_redirects(child, NULL);
1800 return EXIT_SUCCESS;
1802 debug_printf("builtin inline %s\n", argv[0]);
1803 /* XXX setup_redirects acts on file descriptors, not FILEs.
1804 * This is perfect for work that comes after exec().
1805 * Is it really safe for inline use? Experimentally,
1806 * things seem to work with glibc. */
1807 setup_redirects(child, squirrel);
1808 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv[i+1]);
1809 argv_expanded = expand_strvec_to_strvec(argv + i);
1810 rcode = x->function(argv_expanded) & 0xff;
1811 free(argv_expanded);
1812 restore_redirects(squirrel);
1813 debug_printf_exec("run_pipe return %d\n", rcode);
1814 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
1818 #if ENABLE_FEATURE_SH_STANDALONE
1820 int a = find_applet_by_name(argv[i]);
1821 if (a >= 0 && APPLET_IS_NOFORK(a)) {
1822 setup_redirects(child, squirrel);
1823 save_nofork_data(&nofork_save);
1824 argv_expanded = argv + i;
1825 argv_expanded = expand_strvec_to_strvec(argv + i);
1826 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
1827 rcode = run_nofork_applet_prime(&nofork_save, a, argv_expanded);
1828 free(argv_expanded);
1829 restore_redirects(squirrel);
1830 debug_printf_exec("run_pipe return %d\n", rcode);
1831 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
1838 /* Disable job control signals for shell (parent) and
1839 * for initial child code after fork */
1840 set_jobctrl_sighandler(SIG_IGN);
1842 /* Going to fork a child per each pipe member */
1843 pi->alive_progs = 0;
1846 for (i = 0; i < pi->num_progs; i++) {
1848 char **ptrs2free = NULL;
1850 child = &(pi->progs[i]);
1852 debug_printf_exec(": pipe member '%s' '%s'...\n", child->argv[0], child->argv[1]);
1854 ptrs2free = alloc_ptrs(child->argv);
1857 debug_printf_exec(": pipe member with no argv\n");
1859 /* pipes are inserted between pairs of commands */
1862 if ((i + 1) < pi->num_progs)
1865 child->pid = BB_MMU ? fork() : vfork();
1866 if (!child->pid) { /* child */
1867 if (ENABLE_HUSH_JOB)
1868 die_sleep = 0; /* let nofork's xfuncs die */
1870 /* Every child adds itself to new process group
1871 * with pgid == pid_of_first_child_in_pipe */
1872 if (run_list_level == 1 && interactive_fd) {
1874 /* Don't do pgrp restore anymore on fatal signals */
1875 set_fatal_sighandler(SIG_DFL);
1877 if (pgrp < 0) /* true for 1st process only */
1879 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
1880 /* We do it in *every* child, not just first,
1882 tcsetpgrp(interactive_fd, pgrp);
1886 xmove_fd(nextin, 0);
1887 xmove_fd(pipefds[1], 1); /* write end */
1889 close(pipefds[0]); /* read end */
1890 /* Like bash, explicit redirects override pipes,
1891 * and the pipe fd is available for dup'ing. */
1892 setup_redirects(child, NULL);
1894 /* Restore default handlers just prior to exec */
1895 set_jobctrl_sighandler(SIG_DFL);
1896 set_misc_sighandler(SIG_DFL);
1897 signal(SIGCHLD, SIG_DFL);
1898 pseudo_exec(ptrs2free, child); /* does not return */
1901 free_strings(ptrs2free);
1903 if (child->pid < 0) { /* [v]fork failed */
1904 /* Clearly indicate, was it fork or vfork */
1905 bb_perror_msg(BB_MMU ? "fork" : "vfork");
1909 /* Second and next children need to know pid of first one */
1911 pi->pgrp = child->pid;
1917 if ((i + 1) < pi->num_progs)
1918 close(pipefds[1]); /* write end */
1919 /* Pass read (output) pipe end to next iteration */
1920 nextin = pipefds[0];
1923 if (!pi->alive_progs) {
1924 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
1928 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_progs);
1932 #ifndef debug_print_tree
1933 static void debug_print_tree(struct pipe *pi, int lvl)
1935 static const char *PIPE[] = {
1941 static const char *RES[] = {
1942 [RES_NONE ] = "NONE" ,
1945 [RES_THEN ] = "THEN" ,
1946 [RES_ELIF ] = "ELIF" ,
1947 [RES_ELSE ] = "ELSE" ,
1950 #if ENABLE_HUSH_LOOPS
1951 [RES_FOR ] = "FOR" ,
1952 [RES_WHILE] = "WHILE",
1953 [RES_UNTIL] = "UNTIL",
1955 [RES_DONE ] = "DONE" ,
1958 [RES_XXXX ] = "XXXX" ,
1959 [RES_SNTX ] = "SNTX" ,
1966 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
1967 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
1969 while (prn < pi->num_progs) {
1970 struct child_prog *child = &pi->progs[prn];
1971 char **argv = child->argv;
1973 fprintf(stderr, "%*s prog %d", lvl*2, "", prn);
1975 fprintf(stderr, " group %s: (argv=%p)\n",
1976 (child->subshell ? "()" : "{}"),
1978 debug_print_tree(child->group, lvl+1);
1982 if (argv) while (*argv) {
1983 fprintf(stderr, " '%s'", *argv);
1986 fprintf(stderr, "\n");
1995 /* NB: called by pseudo_exec, and therefore must not modify any
1996 * global data until exec/_exit (we can be a child after vfork!) */
1997 static int run_list(struct pipe *pi)
2000 #if ENABLE_HUSH_LOOPS
2001 char *for_varname = NULL;
2002 char **for_lcur = NULL;
2003 char **for_list = NULL;
2007 int rcode = 0; /* probably for gcc only */
2008 int flag_restore = 0;
2010 int if_code = 0, next_if_code = 0; /* need double-buffer to handle elif */
2012 enum { if_code = 0, next_if_code = 0 };
2014 reserved_style rword IF_HAS_NO_KEYWORDS(= RES_NONE);
2015 reserved_style skip_more_for_this_rword = RES_XXXX;
2017 debug_printf_exec("run_list start lvl %d\n", run_list_level + 1);
2019 #if ENABLE_HUSH_LOOPS
2020 /* check syntax for "for" */
2021 for (rpipe = pi; rpipe; rpipe = rpipe->next) {
2022 if ((rpipe->res_word == RES_IN || rpipe->res_word == RES_FOR)
2023 && (rpipe->next == NULL)
2025 syntax("malformed for"); /* no IN or no commands after IN */
2026 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2029 if ((rpipe->res_word == RES_IN && rpipe->next->res_word == RES_IN && rpipe->next->progs[0].argv != NULL)
2030 || (rpipe->res_word == RES_FOR && rpipe->next->res_word != RES_IN)
2032 /* TODO: what is tested in the first condition? */
2033 syntax("malformed for"); /* 2nd condition: FOR not followed by IN */
2034 debug_printf_exec("run_list lvl %d return 1\n", run_list_level);
2043 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2044 * We are saving state before entering outermost list ("while...done")
2045 * so that ctrl-Z will correctly background _entire_ outermost list,
2046 * not just a part of it (like "sleep 1 | exit 2") */
2047 if (++run_list_level == 1 && interactive_fd) {
2048 if (sigsetjmp(toplevel_jb, 1)) {
2049 /* ctrl-Z forked and we are parent; or ctrl-C.
2050 * Sighandler has longjmped us here */
2051 signal(SIGINT, SIG_IGN);
2052 signal(SIGTSTP, SIG_IGN);
2053 /* Restore level (we can be coming from deep inside
2056 #if ENABLE_FEATURE_SH_STANDALONE
2057 if (nofork_save.saved) { /* if save area is valid */
2058 debug_printf_jobs("exiting nofork early\n");
2059 restore_nofork_data(&nofork_save);
2063 /* ctrl-Z has forked and stored pid of the child in pi->pid.
2064 * Remember this child as background job */
2067 /* ctrl-C. We just stop doing whatever we were doing */
2073 /* ctrl-Z handler will store pid etc in pi */
2076 #if ENABLE_FEATURE_SH_STANDALONE
2077 nofork_save.saved = 0; /* in case we will run a nofork later */
2079 signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2080 signal(SIGINT, handler_ctrl_c);
2084 for (; pi; pi = flag_restore ? rpipe : pi->next) {
2085 IF_HAS_KEYWORDS(rword = pi->res_word;)
2086 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
2087 #if ENABLE_HUSH_LOOPS
2088 if (rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR) {
2096 debug_printf_exec(": rword=%d if_code=%d next_if_code=%d skip_more=%d\n",
2097 rword, if_code, next_if_code, skip_more_for_this_rword);
2098 if (rword == skip_more_for_this_rword && flag_skip) {
2099 if (pi->followup == PIPE_SEQ)
2104 skip_more_for_this_rword = RES_XXXX;
2106 if (rword == RES_THEN || rword == RES_ELSE)
2107 if_code = next_if_code;
2108 if (rword == RES_THEN && if_code)
2110 if (rword == RES_ELSE && !if_code)
2112 if (rword == RES_ELIF && !if_code)
2115 #if ENABLE_HUSH_LOOPS
2116 if (rword == RES_FOR && pi->num_progs) {
2118 /* first loop through for */
2119 /* if no variable values after "in" we skip "for" */
2120 if (!pi->next->progs->argv)
2122 /* create list of variable values */
2123 debug_print_strings("for_list made from", pi->next->progs->argv);
2124 for_list = expand_strvec_to_strvec(pi->next->progs->argv);
2125 debug_print_strings("for_list", for_list);
2126 for_lcur = for_list;
2127 for_varname = pi->progs->argv[0];
2128 pi->progs->argv[0] = NULL;
2131 free(pi->progs->argv[0]);
2133 /* for loop is over, clean up */
2137 pi->progs->argv[0] = for_varname;
2140 /* insert next value from for_lcur */
2141 /* vda: does it need escaping? */
2142 pi->progs->argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
2144 if (rword == RES_IN)
2146 if (rword == RES_DO) {
2150 if (rword == RES_DONE) {
2158 if (pi->num_progs == 0)
2160 debug_printf_exec(": run_pipe with %d members\n", pi->num_progs);
2161 rcode = run_pipe(pi);
2163 /* We only ran a builtin: rcode was set by the return value
2164 * of run_pipe(), and we don't need to wait for anything. */
2165 } else if (pi->followup == PIPE_BG) {
2166 /* What does bash do with attempts to background builtins? */
2167 /* Even bash 3.2 doesn't do that well with nested bg:
2168 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
2169 * I'm NOT treating inner &'s as jobs */
2171 if (run_list_level == 1)
2174 rcode = EXIT_SUCCESS;
2177 if (run_list_level == 1 && interactive_fd) {
2178 /* waits for completion, then fg's main shell */
2179 rcode = checkjobs_and_fg_shell(pi);
2183 /* this one just waits for completion */
2184 rcode = checkjobs(pi);
2186 debug_printf_exec(": checkjobs returned %d\n", rcode);
2188 debug_printf_exec(": setting last_return_code=%d\n", rcode);
2189 last_return_code = rcode;
2191 if (rword == RES_IF || rword == RES_ELIF)
2192 next_if_code = rcode; /* can be overwritten a number of times */
2194 #if ENABLE_HUSH_LOOPS
2195 if (rword == RES_WHILE)
2196 flag_rep = !last_return_code;
2197 if (rword == RES_UNTIL)
2198 flag_rep = last_return_code;
2200 if ((rcode == EXIT_SUCCESS && pi->followup == PIPE_OR)
2201 || (rcode != EXIT_SUCCESS && pi->followup == PIPE_AND)
2203 skip_more_for_this_rword = rword;
2210 /* ctrl-Z forked somewhere in the past, we are the child,
2211 * and now we completed running the list. Exit. */
2215 if (!--run_list_level && interactive_fd) {
2216 signal(SIGTSTP, SIG_IGN);
2217 signal(SIGINT, SIG_IGN);
2220 debug_printf_exec("run_list lvl %d return %d\n", run_list_level + 1, rcode);
2224 /* return code is the exit status of the pipe */
2225 static int free_pipe(struct pipe *pi, int indent)
2228 struct child_prog *child;
2229 struct redir_struct *r, *rnext;
2230 int a, i, ret_code = 0;
2232 if (pi->stopped_progs > 0)
2234 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2235 for (i = 0; i < pi->num_progs; i++) {
2236 child = &pi->progs[i];
2237 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2239 for (a = 0, p = child->argv; *p; a++, p++) {
2240 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2242 free_strings(child->argv);
2244 } else if (child->group) {
2245 debug_printf_clean("%s begin group (subshell:%d)\n", indenter(indent), child->subshell);
2246 ret_code = free_pipe_list(child->group, indent+3);
2247 debug_printf_clean("%s end group\n", indenter(indent));
2249 debug_printf_clean("%s (nil)\n", indenter(indent));
2251 for (r = child->redirects; r; r = rnext) {
2252 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2254 /* guard against the case >$FOO, where foo is unset or blank */
2255 if (r->rd_filename) {
2256 debug_printf_clean(" %s\n", r->rd_filename);
2257 free(r->rd_filename);
2258 r->rd_filename = NULL;
2261 debug_printf_clean("&%d\n", r->dup);
2266 child->redirects = NULL;
2268 free(pi->progs); /* children are an array, they get freed all at once */
2277 static int free_pipe_list(struct pipe *head, int indent)
2279 int rcode = 0; /* if list has no members */
2280 struct pipe *pi, *next;
2282 for (pi = head; pi; pi = next) {
2284 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2286 rcode = free_pipe(pi, indent);
2287 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2289 /*pi->next = NULL;*/
2295 /* Select which version we will use */
2296 static int run_and_free_list(struct pipe *pi)
2299 debug_printf_exec("run_and_free_list entered\n");
2301 debug_printf_exec(": run_list with %d members\n", pi->num_progs);
2302 rcode = run_list(pi);
2304 /* free_pipe_list has the side effect of clearing memory.
2305 * In the long run that function can be merged with run_list,
2306 * but doing that now would hobble the debugging effort. */
2307 free_pipe_list(pi, /* indent: */ 0);
2308 debug_printf_exec("run_and_free_list return %d\n", rcode);
2313 /* expand_strvec_to_strvec() takes a list of strings, expands
2314 * all variable references within and returns a pointer to
2315 * a list of expanded strings, possibly with larger number
2316 * of strings. (Think VAR="a b"; echo $VAR).
2317 * This new list is allocated as a single malloc block.
2318 * NULL-terminated list of char* pointers is at the beginning of it,
2319 * followed by strings themself.
2320 * Caller can deallocate entire list by single free(list). */
2322 /* Store given string, finalizing the word and starting new one whenever
2323 * we encounter ifs char(s). This is used for expanding variable values.
2324 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
2325 static int expand_on_ifs(o_string *output, int n, const char *str)
2328 int word_len = strcspn(str, ifs);
2330 if (output->o_quote || !output->o_glob)
2331 o_addQstr(output, str, word_len);
2332 else /* protect backslashes against globbing up :) */
2333 o_addstr_duplicate_backslash(output, str, word_len);
2336 if (!*str) /* EOL - do not finalize word */
2338 o_addchr(output, '\0');
2339 debug_print_list("expand_on_ifs", output, n);
2340 n = o_save_ptr(output, n);
2341 str += strspn(str, ifs); /* skip ifs chars */
2343 debug_print_list("expand_on_ifs[1]", output, n);
2347 /* Expand all variable references in given string, adding words to list[]
2348 * at n, n+1,... positions. Return updated n (so that list[n] is next one
2349 * to be filled). This routine is extremely tricky: has to deal with
2350 * variables/parameters with whitespace, $* and $@, and constructs like
2351 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
2352 /* NB: another bug is that we cannot detect empty strings yet:
2353 * "" or $empty"" expands to zero words, has to expand to empty word */
2354 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
2356 /* or_mask is either 0 (normal case) or 0x80
2357 * (expansion of right-hand side of assignment == 1-element expand.
2358 * It will also do no globbing, and thus we must not backslash-quote!) */
2360 char first_ch, ored_ch;
2367 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
2368 debug_print_list("expand_vars_to_list", output, n);
2369 n = o_save_ptr(output, n);
2370 debug_print_list("expand_vars_to_list[0]", output, n);
2372 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
2373 #if ENABLE_HUSH_TICK
2374 o_string subst_result = NULL_O_STRING;
2377 o_addstr(output, arg, p - arg);
2378 debug_print_list("expand_vars_to_list[1]", output, n);
2380 p = strchr(p, SPECIAL_VAR_SYMBOL);
2382 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
2383 /* "$@" is special. Even if quoted, it can still
2384 * expand to nothing (not even an empty string) */
2385 if ((first_ch & 0x7f) != '@')
2386 ored_ch |= first_ch;
2388 switch (first_ch & 0x7f) {
2389 /* Highest bit in first_ch indicates that var is double-quoted */
2391 val = utoa(root_pid);
2393 case '!': /* bg pid */
2394 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2396 case '?': /* exitcode */
2397 val = utoa(last_return_code);
2399 case '#': /* argc */
2400 val = utoa(global_argc ? global_argc-1 : 0);
2405 if (!global_argv[i])
2407 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2408 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2409 smallint sv = output->o_quote;
2410 /* unquoted var's contents should be globbed, so don't quote */
2411 output->o_quote = 0;
2412 while (global_argv[i]) {
2413 n = expand_on_ifs(output, n, global_argv[i]);
2414 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2415 if (global_argv[i++][0] && global_argv[i]) {
2416 /* this argv[] is not empty and not last:
2417 * put terminating NUL, start new word */
2418 o_addchr(output, '\0');
2419 debug_print_list("expand_vars_to_list[2]", output, n);
2420 n = o_save_ptr(output, n);
2421 debug_print_list("expand_vars_to_list[3]", output, n);
2424 output->o_quote = sv;
2426 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2427 * and in this case should treat it like '$*' - see 'else...' below */
2428 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2430 o_addQstr(output, global_argv[i], strlen(global_argv[i]));
2431 if (++i >= global_argc)
2433 o_addchr(output, '\0');
2434 debug_print_list("expand_vars_to_list[4]", output, n);
2435 n = o_save_ptr(output, n);
2437 } else { /* quoted $*: add as one word */
2439 o_addQstr(output, global_argv[i], strlen(global_argv[i]));
2440 if (!global_argv[++i])
2443 o_addchr(output, ifs[0]);
2447 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2448 /* "Empty variable", used to make "" etc to not disappear */
2452 #if ENABLE_HUSH_TICK
2453 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2454 struct in_str input;
2457 //TODO: can we just stuff it into "output" directly?
2458 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2459 setup_string_in_str(&input, arg);
2460 process_command_subs(&subst_result, &input, NULL);
2461 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2462 val = subst_result.data;
2466 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2468 arg[0] = first_ch & 0x7f;
2469 if (isdigit(arg[0])) {
2471 if (i < global_argc)
2472 val = global_argv[i];
2473 /* else val remains NULL: $N with too big N */
2475 val = lookup_param(arg);
2477 #if ENABLE_HUSH_TICK
2480 *p = SPECIAL_VAR_SYMBOL;
2481 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2482 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
2484 /* unquoted var's contents should be globbed, so don't quote */
2485 smallint sv = output->o_quote;
2486 output->o_quote = 0;
2487 n = expand_on_ifs(output, n, val);
2489 output->o_quote = sv;
2491 } else { /* quoted $VAR, val will be appended below */
2492 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
2496 o_addQstr(output, val, strlen(val));
2499 #if ENABLE_HUSH_TICK
2500 o_free(&subst_result);
2503 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2506 debug_print_list("expand_vars_to_list[a]", output, n);
2507 /* this part is literal, and it was already pre-quoted
2508 * if needed (much earlier), do not use o_addQstr here! */
2509 o_addstr(output, arg, strlen(arg) + 1);
2510 debug_print_list("expand_vars_to_list[b]", output, n);
2511 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2512 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2515 /* allow to reuse list[n] later without re-growth */
2516 output->has_empty_slot = 1;
2518 o_addchr(output, '\0');
2523 static char **expand_variables(char **argv, int or_mask)
2528 o_string output = NULL_O_STRING;
2530 if (or_mask & 0x100) {
2531 output.o_quote = 1; /* protect against globbing for "$var" */
2532 /* (unquoted $var will temporarily switch it off) */
2539 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2542 debug_print_list("expand_variables", &output, n);
2544 /* output.data (malloced in one block) gets returned in "list" */
2545 list = o_finalize_list(&output, n);
2546 debug_print_strings("expand_variables[1]", list);
2550 static char **expand_strvec_to_strvec(char **argv)
2552 return expand_variables(argv, 0x100);
2555 /* Used for expansion of right hand of assignments */
2556 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2558 static char *expand_string_to_string(const char *str)
2560 char *argv[2], **list;
2562 argv[0] = (char*)str;
2564 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2566 if (!list[0] || list[1])
2567 bb_error_msg_and_die("BUG in varexp2");
2568 /* actually, just move string 2*sizeof(char*) bytes back */
2569 strcpy((char*)list, list[0]);
2570 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2574 /* Used for "eval" builtin */
2575 static char* expand_strvec_to_string(char **argv)
2579 list = expand_variables(argv, 0x80);
2580 /* Convert all NULs to spaces */
2585 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2586 bb_error_msg_and_die("BUG in varexp3");
2587 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2591 strcpy((char*)list, list[0]);
2592 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2597 /* Used to get/check local shell variables */
2598 static struct variable *get_local_var(const char *name)
2600 struct variable *cur;
2606 for (cur = top_var; cur; cur = cur->next) {
2607 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2613 /* str holds "NAME=VAL" and is expected to be malloced.
2614 * We take ownership of it. */
2615 static int set_local_var(char *str, int flg_export)
2617 struct variable *cur;
2621 value = strchr(str, '=');
2622 if (!value) { /* not expected to ever happen? */
2627 name_len = value - str + 1; /* including '=' */
2628 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2630 if (strncmp(cur->varstr, str, name_len) != 0) {
2632 /* Bail out. Note that now cur points
2633 * to last var in linked list */
2639 /* We found an existing var with this name */
2641 if (cur->flg_read_only) {
2642 bb_error_msg("%s: readonly variable", str);
2646 unsetenv(str); /* just in case */
2648 if (strcmp(cur->varstr, str) == 0) {
2653 if (cur->max_len >= strlen(str)) {
2654 /* This one is from startup env, reuse space */
2655 strcpy(cur->varstr, str);
2658 /* max_len == 0 signifies "malloced" var, which we can
2659 * (and has to) free */
2663 goto set_str_and_exp;
2666 /* Not found - create next variable struct */
2667 cur->next = xzalloc(sizeof(*cur));
2674 cur->flg_export = 1;
2675 if (cur->flg_export)
2676 return putenv(cur->varstr);
2680 static void unset_local_var(const char *name)
2682 struct variable *cur;
2683 struct variable *prev = prev; /* for gcc */
2688 name_len = strlen(name);
2691 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2692 if (cur->flg_read_only) {
2693 bb_error_msg("%s: readonly variable", name);
2696 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2697 * is ro, and we cannot reach this code on the 1st pass */
2698 prev->next = cur->next;
2699 unsetenv(cur->varstr);
2710 /* the src parameter allows us to peek forward to a possible &n syntax
2711 * for file descriptor duplication, e.g., "2>&1".
2712 * Return code is 0 normally, 1 if a syntax error is detected in src.
2713 * Resource errors (in xmalloc) cause the process to exit */
2714 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2715 struct in_str *input)
2717 struct child_prog *child = ctx->child;
2718 struct redir_struct *redir = child->redirects;
2719 struct redir_struct *last_redir = NULL;
2721 /* Create a new redir_struct and drop it onto the end of the linked list */
2724 redir = redir->next;
2726 redir = xzalloc(sizeof(struct redir_struct));
2727 /* redir->next = NULL; */
2728 /* redir->rd_filename = NULL; */
2730 last_redir->next = redir;
2732 child->redirects = redir;
2735 redir->rd_type = style;
2736 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2738 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2740 /* Check for a '2>&1' type redirect */
2741 redir->dup = redirect_dup_num(input);
2742 if (redir->dup == -2)
2743 return 1; /* syntax error */
2744 if (redir->dup != -1) {
2745 /* Erik had a check here that the file descriptor in question
2746 * is legit; I postpone that to "run time"
2747 * A "-" representation of "close me" shows up as a -3 here */
2748 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2750 /* We do _not_ try to open the file that src points to,
2751 * since we need to return and let src be expanded first.
2752 * Set ctx->pending_redirect, so we know what to do at the
2753 * end of the next parsed word. */
2754 ctx->pending_redirect = redir;
2759 static struct pipe *new_pipe(void)
2762 pi = xzalloc(sizeof(struct pipe));
2763 /*pi->followup = 0; - deliberately invalid value */
2764 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2768 static void initialize_context(struct p_context *ctx)
2770 memset(ctx, 0, sizeof(*ctx));
2771 ctx->pipe = ctx->list_head = new_pipe();
2772 /* Create the memory for child, roughly:
2773 * ctx->pipe->progs = new struct child_prog;
2774 * ctx->pipe->progs[0].family = ctx->pipe;
2775 * ctx->child = &ctx->pipe->progs[0];
2780 /* If a reserved word is found and processed, parse context is modified
2781 * and 1 is returned.
2782 * Handles if, then, elif, else, fi, for, while, until, do, done.
2783 * case, function, and select are obnoxious, save those for later.
2786 static int reserved_word(const o_string *word, struct p_context *ctx)
2788 struct reserved_combo {
2794 FLAG_END = (1 << RES_NONE ),
2796 FLAG_IF = (1 << RES_IF ),
2797 FLAG_THEN = (1 << RES_THEN ),
2798 FLAG_ELIF = (1 << RES_ELIF ),
2799 FLAG_ELSE = (1 << RES_ELSE ),
2800 FLAG_FI = (1 << RES_FI ),
2802 #if ENABLE_HUSH_LOOPS
2803 FLAG_FOR = (1 << RES_FOR ),
2804 FLAG_WHILE = (1 << RES_WHILE),
2805 FLAG_UNTIL = (1 << RES_UNTIL),
2806 FLAG_DO = (1 << RES_DO ),
2807 FLAG_DONE = (1 << RES_DONE ),
2808 FLAG_IN = (1 << RES_IN ),
2810 FLAG_START = (1 << RES_XXXX ),
2812 /* Mostly a list of accepted follow-up reserved words.
2813 * FLAG_END means we are done with the sequence, and are ready
2814 * to turn the compound list into a command.
2815 * FLAG_START means the word must start a new compound list.
2817 static const struct reserved_combo reserved_list[] = {
2819 { "!", RES_NONE, 0 },
2820 { "if", RES_IF, FLAG_THEN | FLAG_START },
2821 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2822 { "elif", RES_ELIF, FLAG_THEN },
2823 { "else", RES_ELSE, FLAG_FI },
2824 { "fi", RES_FI, FLAG_END },
2826 #if ENABLE_HUSH_LOOPS
2827 { "for", RES_FOR, FLAG_IN | FLAG_START },
2828 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2829 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2830 { "in", RES_IN, FLAG_DO },
2831 { "do", RES_DO, FLAG_DONE },
2832 { "done", RES_DONE, FLAG_END }
2836 const struct reserved_combo *r;
2838 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2839 if (strcmp(word->data, r->literal) != 0)
2841 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2842 if (r->flag == 0) { /* '!' */
2843 #if ENABLE_HUSH_LOOPS
2844 if (ctx->ctx_res_w == RES_IN) {
2845 /* 'for a in ! a b c; ...' - ! isn't a keyword here */
2849 if (ctx->ctx_inverted /* bash doesn't accept '! ! true' */
2850 #if ENABLE_HUSH_LOOPS
2851 || ctx->ctx_res_w == RES_FOR /* example: 'for ! a' */
2855 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
2857 ctx->ctx_inverted = 1;
2860 if (r->flag & FLAG_START) {
2861 struct p_context *new;
2862 debug_printf("push stack\n");
2863 #if ENABLE_HUSH_LOOPS
2864 if (ctx->ctx_res_w == RES_IN || ctx->ctx_res_w == RES_FOR) {
2865 syntax("malformed for"); /* example: 'for if' */
2866 ctx->ctx_res_w = RES_SNTX;
2870 new = xmalloc(sizeof(*new));
2871 *new = *ctx; /* physical copy */
2872 initialize_context(ctx);
2874 } else if (ctx->ctx_res_w == RES_NONE || !(ctx->old_flag & (1 << r->res))) {
2876 ctx->ctx_res_w = RES_SNTX;
2879 ctx->ctx_res_w = r->res;
2880 ctx->old_flag = r->flag;
2881 if (ctx->old_flag & FLAG_END) {
2882 struct p_context *old;
2883 debug_printf("pop stack\n");
2884 done_pipe(ctx, PIPE_SEQ);
2886 old->child->group = ctx->list_head;
2887 old->child->subshell = 0;
2888 *ctx = *old; /* physical copy */
2897 /* Word is complete, look at it and update parsing context.
2898 * Normal return is 0. Syntax errors return 1. */
2899 static int done_word(o_string *word, struct p_context *ctx)
2901 struct child_prog *child = ctx->child;
2903 /* If this word wasn't an assignment, next ones definitely
2904 * can't be assignments. Even if they look like ones. */
2905 if (word->o_assignment != DEFINITELY_ASSIGNMENT) {
2906 word->o_assignment = NOT_ASSIGNMENT;
2908 word->o_assignment = MAYBE_ASSIGNMENT;
2911 debug_printf_parse("done_word entered: '%s' %p\n", word->data, child);
2912 if (word->length == 0 && word->nonnull == 0) {
2913 debug_printf_parse("done_word return 0: true null, ignored\n");
2916 if (ctx->pending_redirect) {
2917 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
2918 * only if run as "bash", not "sh" */
2919 ctx->pending_redirect->rd_filename = xstrdup(word->data);
2920 word->o_assignment = NOT_ASSIGNMENT;
2921 debug_printf("word stored in rd_filename: '%s'\n", word->data);
2923 if (child->group) { /* TODO: example how to trigger? */
2925 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
2929 if (!child->argv) { /* if it's the first word... */
2930 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
2931 if (reserved_word(word, ctx)) {
2933 word->o_assignment = NOT_ASSIGNMENT;
2934 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
2935 return (ctx->ctx_res_w == RES_SNTX);
2939 if (word->nonnull /* word had "xx" or 'xx' at least as part of it */
2940 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
2941 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
2942 /* (otherwise it's "abc".... and is already safe) */
2944 /* but exclude "$@"! it expands to no word despite "" */
2945 char *p = word->data;
2946 while (p[0] == SPECIAL_VAR_SYMBOL
2947 && (p[1] & 0x7f) == '@'
2948 && p[2] == SPECIAL_VAR_SYMBOL
2952 if (p == word->data || p[0] != '\0') {
2953 /* Insert "empty variable" reference, this makes
2954 * e.g. "", $empty"" etc to not disappear */
2955 o_addchr(word, SPECIAL_VAR_SYMBOL);
2956 o_addchr(word, SPECIAL_VAR_SYMBOL);
2959 child->argv = add_malloced_string_to_strings(child->argv, xstrdup(word->data));
2960 debug_print_strings("word appended to argv", child->argv);
2964 ctx->pending_redirect = NULL;
2966 #if ENABLE_HUSH_LOOPS
2967 /* Force FOR to have just one word (variable name) */
2968 if (ctx->ctx_res_w == RES_FOR)
2969 done_pipe(ctx, PIPE_SEQ);
2971 debug_printf_parse("done_word return 0\n");
2975 /* Command (member of a pipe) is complete. The only possible error here
2976 * is out of memory, in which case xmalloc exits. */
2977 static int done_command(struct p_context *ctx)
2979 /* The child is really already in the pipe structure, so
2980 * advance the pipe counter and make a new, null child. */
2981 struct pipe *pi = ctx->pipe;
2982 struct child_prog *child = ctx->child;
2985 if (child->group == NULL
2986 && child->argv == NULL
2987 && child->redirects == NULL
2989 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
2990 return pi->num_progs;
2993 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
2995 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
2998 /* Only real trickiness here is that the uncommitted
2999 * child structure is not counted in pi->num_progs. */
3000 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
3001 child = &pi->progs[pi->num_progs];
3003 memset(child, 0, sizeof(*child));
3007 /* but ctx->pipe and ctx->list_head remain unchanged */
3009 return pi->num_progs; /* used only for 0/nonzero check */
3012 static void done_pipe(struct p_context *ctx, pipe_style type)
3016 debug_printf_parse("done_pipe entered, followup %d\n", type);
3017 not_null = done_command(ctx); /* implicit closure of previous command */
3018 ctx->pipe->followup = type;
3019 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3020 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3021 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3022 /* Without this check, even just <enter> on command line generates
3023 * tree of three NOPs (!). Which is harmless but annoying.
3024 * IOW: it is safe to do it unconditionally.
3025 * RES_IN case is for "for a in; do ..." (empty IN set)
3027 if (not_null USE_HUSH_LOOPS(|| ctx->pipe->res_word == RES_IN)) {
3028 struct pipe *new_p = new_pipe();
3029 ctx->pipe->next = new_p;
3031 ctx->child = NULL; /* needed! */
3032 /* Create the memory for child, roughly:
3033 * ctx->pipe->progs = new struct child_prog;
3034 * ctx->pipe->progs[0].family = ctx->pipe;
3035 * ctx->child = &ctx->pipe->progs[0];
3039 debug_printf_parse("done_pipe return\n");
3042 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3043 * as in "2>&1", that represents duplicating a file descriptor.
3044 * Return either -2 (syntax error), -1 (no &), or the number found.
3046 static int redirect_dup_num(struct in_str *input)
3048 int ch, d = 0, ok = 0;
3050 if (ch != '&') return -1;
3052 i_getch(input); /* get the & */
3056 return -3; /* "-" represents "close me" */
3058 while (isdigit(ch)) {
3059 d = d*10 + (ch-'0');
3066 bb_error_msg("ambiguous redirect");
3070 /* If a redirect is immediately preceded by a number, that number is
3071 * supposed to tell which file descriptor to redirect. This routine
3072 * looks for such preceding numbers. In an ideal world this routine
3073 * needs to handle all the following classes of redirects...
3074 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3075 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3076 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3077 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3078 * A -1 output from this program means no valid number was found, so the
3079 * caller should use the appropriate default for this redirection.
3081 static int redirect_opt_num(o_string *o)
3087 for (num = 0; num < o->length; num++) {
3088 if (!isdigit(o->data[num])) {
3092 num = atoi(o->data);
3097 #if ENABLE_HUSH_TICK
3098 static FILE *generate_stream_from_list(struct pipe *head)
3101 int pid, channel[2];
3104 /* *** NOMMU WARNING *** */
3105 /* By using vfork here, we suspend parent till child exits or execs.
3106 * If child will not do it before it fills the pipe, it can block forever
3107 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3109 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3110 * huge=`cat TESTFILE` # will block here forever
3113 pid = BB_MMU ? fork() : vfork();
3115 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3116 if (pid == 0) { /* child */
3117 if (ENABLE_HUSH_JOB)
3118 die_sleep = 0; /* let nofork's xfuncs die */
3119 close(channel[0]); /* NB: close _first_, then move fd! */
3120 xmove_fd(channel[1], 1);
3121 /* Prevent it from trying to handle ctrl-z etc */
3125 /* Process substitution is not considered to be usual
3126 * 'command execution'.
3127 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3128 /* Not needed, we are relying on it being disabled
3129 * everywhere outside actual command execution. */
3130 /*set_jobctrl_sighandler(SIG_IGN);*/
3131 set_misc_sighandler(SIG_DFL);
3132 /* Freeing 'head' here would break NOMMU. */
3133 _exit(run_list(head));
3136 pf = fdopen(channel[0], "r");
3138 /* 'head' is freed by the caller */
3141 /* Return code is exit status of the process that is run. */
3142 static int process_command_subs(o_string *dest,
3143 struct in_str *input,
3144 const char *subst_end)
3146 int retcode, ch, eol_cnt;
3147 o_string result = NULL_O_STRING;
3148 struct p_context inner;
3150 struct in_str pipe_str;
3152 initialize_context(&inner);
3154 /* Recursion to generate command */
3155 retcode = parse_stream(&result, &inner, input, subst_end);
3157 return retcode; /* syntax error or EOF */
3158 done_word(&result, &inner);
3159 done_pipe(&inner, PIPE_SEQ);
3162 p = generate_stream_from_list(inner.list_head);
3165 close_on_exec_on(fileno(p));
3166 setup_file_in_str(&pipe_str, p);
3168 /* Now send results of command back into original context */
3170 while ((ch = i_getch(&pipe_str)) != EOF) {
3176 o_addchr(dest, '\n');
3179 // /* Even unquoted `echo '\'` results in two backslashes
3180 // * (which are converted into one by globbing later) */
3181 // if (!dest->o_quote && ch == '\\') {
3182 // o_addchr(dest, ch);
3184 o_addQchr(dest, ch);
3187 debug_printf("done reading from pipe, pclose()ing\n");
3188 /* This is the step that wait()s for the child. Should be pretty
3189 * safe, since we just read an EOF from its stdout. We could try
3190 * to do better, by using wait(), and keeping track of background jobs
3191 * at the same time. That would be a lot of work, and contrary
3192 * to the KISS philosophy of this program. */
3193 retcode = fclose(p);
3194 free_pipe_list(inner.list_head, /* indent: */ 0);
3195 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3200 static int parse_group(o_string *dest, struct p_context *ctx,
3201 struct in_str *input, int ch)
3204 const char *endch = NULL;
3205 struct p_context sub;
3206 struct child_prog *child = ctx->child;
3208 debug_printf_parse("parse_group entered\n");
3211 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3214 initialize_context(&sub);
3218 child->subshell = 1;
3220 rcode = parse_stream(dest, &sub, input, endch);
3222 done_word(dest, &sub); /* finish off the final word in the subcontext */
3223 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3224 child->group = sub.list_head;
3226 debug_printf_parse("parse_group return %d\n", rcode);
3228 /* child remains "open", available for possible redirects */
3231 /* Basically useful version until someone wants to get fancier,
3232 * see the bash man page under "Parameter Expansion" */
3233 static const char *lookup_param(const char *src)
3235 struct variable *var = get_local_var(src);
3237 return strchr(var->varstr, '=') + 1;
3241 #if ENABLE_HUSH_TICK
3242 /* Subroutines for copying $(...) and `...` things */
3243 static void add_till_backquote(o_string *dest, struct in_str *input);
3245 static void add_till_single_quote(o_string *dest, struct in_str *input)
3248 int ch = i_getch(input);
3256 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3257 static void add_till_double_quote(o_string *dest, struct in_str *input)
3260 int ch = i_getch(input);
3263 if (ch == '\\') { /* \x. Copy both chars. */
3265 ch = i_getch(input);
3271 add_till_backquote(dest, input);
3275 //if (ch == '$') ...
3278 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3280 * "Within the backquoted style of command substitution, backslash
3281 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3282 * The search for the matching backquote shall be satisfied by the first
3283 * backquote found without a preceding backslash; during this search,
3284 * if a non-escaped backquote is encountered within a shell comment,
3285 * a here-document, an embedded command substitution of the $(command)
3286 * form, or a quoted string, undefined results occur. A single-quoted
3287 * or double-quoted string that begins, but does not end, within the
3288 * "`...`" sequence produces undefined results."
3290 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3292 static void add_till_backquote(o_string *dest, struct in_str *input)
3295 int ch = i_getch(input);
3298 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3299 int ch2 = i_getch(input);
3300 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3309 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3310 * quoting and nested ()s.
3311 * "With the $(command) style of command substitution, all characters
3312 * following the open parenthesis to the matching closing parenthesis
3313 * constitute the command. Any valid shell script can be used for command,
3314 * except a script consisting solely of redirections which produces
3315 * unspecified results."
3317 * echo $(echo '(TEST)' BEST) (TEST) BEST
3318 * echo $(echo 'TEST)' BEST) TEST) BEST
3319 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3321 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3325 int ch = i_getch(input);
3335 add_till_single_quote(dest, input);
3340 add_till_double_quote(dest, input);
3344 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3345 ch = i_getch(input);
3353 #endif /* ENABLE_HUSH_TICK */
3355 /* Return code: 0 for OK, 1 for syntax error */
3356 static int handle_dollar(o_string *dest, struct in_str *input)
3358 int ch = i_peek(input); /* first character after the $ */
3359 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3361 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3363 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3365 debug_printf_parse(": '%c'\n", ch);
3367 o_addchr(dest, ch | quote_mask);
3370 if (!isalnum(ch) && ch != '_')
3373 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3374 } else if (isdigit(ch)) {
3376 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3377 debug_printf_parse(": '%c'\n", ch);
3379 o_addchr(dest, ch | quote_mask);
3380 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3381 } else switch (ch) {
3383 case '!': /* last bg pid */
3384 case '?': /* last exit code */
3385 case '#': /* number of args */
3386 case '*': /* args */
3387 case '@': /* args */
3388 goto make_one_char_var;
3390 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3392 /* XXX maybe someone will try to escape the '}' */
3394 ch = i_getch(input);
3397 if (!isalnum(ch) && ch != '_') {
3398 syntax("unterminated ${name}");
3399 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3402 debug_printf_parse(": '%c'\n", ch);
3403 o_addchr(dest, ch | quote_mask);
3406 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3408 #if ENABLE_HUSH_TICK
3410 //int pos = dest->length;
3412 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3413 o_addchr(dest, quote_mask | '`');
3414 add_till_closing_curly_brace(dest, input);
3415 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
3416 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3422 /* still unhandled, but should be eventually */
3423 bb_error_msg("unhandled syntax: $%c", ch);
3427 o_addQchr(dest, '$');
3429 debug_printf_parse("handle_dollar return 0\n");
3433 /* Scan input, call done_word() whenever full IFS delemited word was seen.
3434 * call done_pipe if '\n' was seen (and end_trigger != NULL)
3435 * Return if (non-quoted) char in end_trigger was seen; or on parse error. */
3436 /* Return code is 0 if end_trigger char is met,
3437 * -1 on EOF (but if end_trigger == NULL then return 0)
3438 * 1 for syntax error */
3439 static int parse_stream(o_string *dest, struct p_context *ctx,
3440 struct in_str *input, const char *end_trigger)
3444 redir_type redir_style;
3445 int shadow_quote = dest->o_quote;
3448 /* Only double-quote state is handled in the state variable dest->o_quote.
3449 * A single-quote triggers a bypass of the main loop until its mate is
3450 * found. When recursing, quote state is passed in via dest->o_quote. */
3452 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3457 ch = i_getch(input);
3461 next = i_peek(input);
3464 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3465 ch, ch, m, dest->o_quote);
3466 if (m == CHAR_ORDINARY
3467 || (m != CHAR_SPECIAL && shadow_quote)
3470 syntax("unterminated \"");
3471 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3474 o_addQchr(dest, ch);
3475 if (dest->o_assignment == MAYBE_ASSIGNMENT
3477 && is_assignment(dest->data)
3479 dest->o_assignment = DEFINITELY_ASSIGNMENT;
3483 if (m == CHAR_IFS) {
3484 if (done_word(dest, ctx)) {
3485 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3490 /* If we aren't performing a substitution, treat
3491 * a newline as a command separator.
3492 * [why we don't handle it exactly like ';'? --vda] */
3493 if (end_trigger && ch == '\n') {
3494 done_pipe(ctx, PIPE_SEQ);
3498 if (!shadow_quote && strchr(end_trigger, ch)) {
3499 /* Special case: (...word) makes last word terminate,
3500 * as if ';' is seen */
3502 done_word(dest, ctx);
3504 done_pipe(ctx, PIPE_SEQ);
3506 if (!HAS_KEYWORDS IF_HAS_KEYWORDS(|| ctx->ctx_res_w == RES_NONE)) {
3507 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3515 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
3516 /* ch is a special char and thus this word
3517 * cannot be an assignment: */
3518 dest->o_assignment = NOT_ASSIGNMENT;
3523 if (dest->length == 0 && !shadow_quote) {
3526 if (ch == EOF || ch == '\n')
3531 o_addQchr(dest, ch);
3537 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3541 * "The backslash retains its special meaning [in "..."]
3542 * only when followed by one of the following characters:
3543 * $, `, ", \, or <newline>. A double quote may be quoted
3544 * within double quotes by preceding it with a backslash.
3545 * If enabled, history expansion will be performed unless
3546 * an ! appearing in double quotes is escaped using
3547 * a backslash. The backslash preceding the ! is not removed."
3549 if (shadow_quote) { //NOT SURE dest->o_quote) {
3550 if (strchr("$`\"\\", next) != NULL) {
3551 o_addqchr(dest, i_getch(input));
3553 o_addqchr(dest, '\\');
3556 o_addchr(dest, '\\');
3557 o_addchr(dest, i_getch(input));
3561 if (handle_dollar(dest, input) != 0) {
3562 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3569 ch = i_getch(input);
3571 syntax("unterminated '");
3572 debug_printf_parse("parse_stream return 1: unterminated '\n");
3577 if (dest->o_assignment == NOT_ASSIGNMENT)
3578 o_addqchr(dest, ch);
3585 shadow_quote ^= 1; /* invert */
3586 if (dest->o_assignment == NOT_ASSIGNMENT)
3589 #if ENABLE_HUSH_TICK
3591 //int pos = dest->length;
3592 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3593 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
3594 add_till_backquote(dest, input);
3595 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3596 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3601 redir_fd = redirect_opt_num(dest);
3602 done_word(dest, ctx);
3603 redir_style = REDIRECT_OVERWRITE;
3605 redir_style = REDIRECT_APPEND;
3609 else if (next == '(') {
3610 syntax(">(process) not supported");
3611 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3615 setup_redirect(ctx, redir_fd, redir_style, input);
3618 redir_fd = redirect_opt_num(dest);
3619 done_word(dest, ctx);
3620 redir_style = REDIRECT_INPUT;
3622 redir_style = REDIRECT_HEREIS;
3624 } else if (next == '>') {
3625 redir_style = REDIRECT_IO;
3629 else if (next == '(') {
3630 syntax("<(process) not supported");
3631 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3635 setup_redirect(ctx, redir_fd, redir_style, input);
3638 done_word(dest, ctx);
3639 done_pipe(ctx, PIPE_SEQ);
3642 done_word(dest, ctx);
3645 done_pipe(ctx, PIPE_AND);
3647 done_pipe(ctx, PIPE_BG);
3651 done_word(dest, ctx);
3654 done_pipe(ctx, PIPE_OR);
3656 /* we could pick up a file descriptor choice here
3657 * with redirect_opt_num(), but bash doesn't do it.
3658 * "echo foo 2| cat" yields "foo 2". */
3664 if (parse_group(dest, ctx, input, ch) != 0) {
3665 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3671 /* proper use of this character is caught by end_trigger */
3672 syntax("unexpected } or )");
3673 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3677 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3680 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3686 static void set_in_charmap(const char *set, int code)
3689 charmap[(unsigned char)*set++] = code;
3692 static void update_charmap(void)
3694 /* char *ifs and char charmap[256] are both globals. */
3695 ifs = getenv("IFS");
3698 /* Precompute a list of 'flow through' behavior so it can be treated
3699 * quickly up front. Computation is necessary because of IFS.
3700 * Special case handling of IFS == " \t\n" is not implemented.
3701 * The charmap[] array only really needs two bits each,
3702 * and on most machines that would be faster (reduced L1 cache use).
3704 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3705 #if ENABLE_HUSH_TICK
3706 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3708 set_in_charmap("\\$\"", CHAR_SPECIAL);
3710 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3711 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3714 /* Most recursion does not come through here, the exception is
3715 * from builtin_source() and builtin_eval() */
3716 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3718 struct p_context ctx;
3719 o_string temp = NULL_O_STRING;
3723 initialize_context(&ctx);
3725 #if ENABLE_HUSH_INTERACTIVE
3726 inp->promptmode = 0; /* PS1 */
3728 /* We will stop & execute after each ';' or '\n'.
3729 * Example: "sleep 9999; echo TEST" + ctrl-C:
3730 * TEST should be printed */
3731 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3733 if (rcode != 1 && ctx.old_flag != 0) {
3737 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
3738 done_word(&temp, &ctx);
3739 done_pipe(&ctx, PIPE_SEQ);
3740 debug_print_tree(ctx.list_head, 0);
3741 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
3742 run_and_free_list(ctx.list_head);
3744 /* We arrive here also if rcode == 1 (error in parse_stream) */
3746 if (ctx.old_flag != 0) {
3751 /*temp.nonnull = 0; - o_free does it below */
3752 /*temp.o_quote = 0; - o_free does it below */
3753 free_pipe_list(ctx.list_head, /* indent: */ 0);
3754 /* Discard all unprocessed line input, force prompt on */
3756 #if ENABLE_HUSH_INTERACTIVE
3761 /* loop on syntax errors, return on EOF: */
3762 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
3766 static int parse_and_run_string(const char *s, int parse_flag)
3768 struct in_str input;
3769 setup_string_in_str(&input, s);
3770 return parse_and_run_stream(&input, parse_flag);
3773 static int parse_and_run_file(FILE *f)
3776 struct in_str input;
3777 setup_file_in_str(&input, f);
3778 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
3783 /* Make sure we have a controlling tty. If we get started under a job
3784 * aware app (like bash for example), make sure we are now in charge so
3785 * we don't fight over who gets the foreground */
3786 static void setup_job_control(void)
3790 saved_task_pgrp = shell_pgrp = getpgrp();
3791 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3792 close_on_exec_on(interactive_fd);
3794 /* If we were ran as 'hush &',
3795 * sleep until we are in the foreground. */
3796 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3797 /* Send TTIN to ourself (should stop us) */
3798 kill(- shell_pgrp, SIGTTIN);
3799 shell_pgrp = getpgrp();
3802 /* Ignore job-control and misc signals. */
3803 set_jobctrl_sighandler(SIG_IGN);
3804 set_misc_sighandler(SIG_IGN);
3805 //huh? signal(SIGCHLD, SIG_IGN);
3807 /* We _must_ restore tty pgrp on fatal signals */
3808 set_fatal_sighandler(sigexit);
3810 /* Put ourselves in our own process group. */
3811 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3812 /* Grab control of the terminal. */
3813 tcsetpgrp(interactive_fd, getpid());
3818 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3819 int hush_main(int argc, char **argv)
3821 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3822 static const struct variable const_shell_ver = {
3824 .varstr = (char*)version_str,
3825 .max_len = 1, /* 0 can provoke free(name) */
3833 struct variable *cur_var;
3837 root_pid = getpid();
3839 /* Deal with HUSH_VERSION */
3840 shell_ver = const_shell_ver; /* copying struct here */
3841 top_var = &shell_ver;
3842 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3843 /* Initialize our shell local variables with the values
3844 * currently living in the environment */
3848 char *value = strchr(*e, '=');
3849 if (value) { /* paranoia */
3850 cur_var->next = xzalloc(sizeof(*cur_var));
3851 cur_var = cur_var->next;
3852 cur_var->varstr = *e;
3853 cur_var->max_len = strlen(*e);
3854 cur_var->flg_export = 1;
3858 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3860 #if ENABLE_FEATURE_EDITING
3861 line_input_state = new_line_input_t(FOR_SHELL);
3863 /* XXX what should these be while sourcing /etc/profile? */
3866 /* Initialize some more globals to non-zero values */
3868 #if ENABLE_HUSH_INTERACTIVE
3869 #if ENABLE_FEATURE_EDITING
3870 cmdedit_set_initial_prompt();
3875 if (EXIT_SUCCESS) /* otherwise is already done */
3876 last_return_code = EXIT_SUCCESS;
3878 if (argv[0] && argv[0][0] == '-') {
3879 debug_printf("sourcing /etc/profile\n");
3880 input = fopen("/etc/profile", "r");
3881 if (input != NULL) {
3882 close_on_exec_on(fileno(input));
3883 parse_and_run_file(input);
3889 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3892 global_argv = argv + optind;
3893 global_argc = argc - optind;
3894 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
3897 /* Well, we cannot just declare interactiveness,
3898 * we have to have some stuff (ctty, etc) */
3899 /* interactive_fd++; */
3906 fprintf(stderr, "Usage: sh [FILE]...\n"
3907 " or: sh -c command [args]...\n\n");
3915 /* A shell is interactive if the '-i' flag was given, or if all of
3916 * the following conditions are met:
3918 * no arguments remaining or the -s flag given
3919 * standard input is a terminal
3920 * standard output is a terminal
3921 * Refer to Posix.2, the description of the 'sh' utility. */
3922 if (argv[optind] == NULL && input == stdin
3923 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3925 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3926 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3927 if (saved_tty_pgrp >= 0) {
3928 /* try to dup to high fd#, >= 255 */
3929 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3930 if (interactive_fd < 0) {
3931 /* try to dup to any fd */
3932 interactive_fd = dup(STDIN_FILENO);
3933 if (interactive_fd < 0)
3937 // TODO: track & disallow any attempts of user
3938 // to (inadvertently) close/redirect it
3941 debug_printf("interactive_fd=%d\n", interactive_fd);
3942 if (interactive_fd) {
3943 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3944 /* Looks like they want an interactive shell */
3945 setup_job_control();
3946 /* -1 is special - makes xfuncs longjmp, not exit
3947 * (we reset die_sleep = 0 whereever we [v]fork) */
3949 if (setjmp(die_jmp)) {
3950 /* xfunc has failed! die die die */
3951 hush_exit(xfunc_error_retval);
3953 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3954 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3955 printf("Enter 'help' for a list of built-in commands.\n\n");
3958 #elif ENABLE_HUSH_INTERACTIVE
3959 /* no job control compiled, only prompt/line editing */
3960 if (argv[optind] == NULL && input == stdin
3961 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3963 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3964 if (interactive_fd < 0) {
3965 /* try to dup to any fd */
3966 interactive_fd = dup(STDIN_FILENO);
3967 if (interactive_fd < 0)
3971 if (interactive_fd) {
3972 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3973 set_misc_sighandler(SIG_IGN);
3978 if (argv[optind] == NULL) {
3979 opt = parse_and_run_file(stdin);
3981 debug_printf("\nrunning script '%s'\n", argv[optind]);
3982 global_argv = argv + optind;
3983 global_argc = argc - optind;
3984 input = xfopen(argv[optind], "r");
3985 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
3986 opt = parse_and_run_file(input);
3991 #if ENABLE_FEATURE_CLEAN_UP
3993 if (cwd != bb_msg_unknown)
3995 cur_var = top_var->next;
3997 struct variable *tmp = cur_var;
3998 if (!cur_var->max_len)
3999 free(cur_var->varstr);
4000 cur_var = cur_var->next;
4004 hush_exit(opt ? opt : last_return_code);
4009 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4010 int lash_main(int argc, char **argv)
4012 //bb_error_msg("lash is deprecated, please use hush instead");
4013 return hush_main(argc, argv);
4021 static int builtin_true(char **argv UNUSED_PARAM)
4026 static int builtin_test(char **argv)
4033 return test_main(argc, argv - argc);
4036 static int builtin_echo(char **argv)
4043 return echo_main(argc, argv - argc);
4046 static int builtin_eval(char **argv)
4048 int rcode = EXIT_SUCCESS;
4051 char *str = expand_strvec_to_string(argv + 1);
4052 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4054 rcode = last_return_code;
4059 static int builtin_cd(char **argv)
4062 if (argv[1] == NULL) {
4063 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4064 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4065 newdir = getenv("HOME") ? : "/";
4068 if (chdir(newdir)) {
4069 printf("cd: %s: %s\n", newdir, strerror(errno));
4070 return EXIT_FAILURE;
4073 return EXIT_SUCCESS;
4076 static int builtin_exec(char **argv)
4078 if (argv[1] == NULL)
4079 return EXIT_SUCCESS; /* bash does this */
4082 char **ptrs2free = alloc_ptrs(argv);
4084 // FIXME: if exec fails, bash does NOT exit! We do...
4085 pseudo_exec_argv(ptrs2free, argv + 1);
4090 static int builtin_exit(char **argv)
4092 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4093 //puts("exit"); /* bash does it */
4094 // TODO: warn if we have background jobs: "There are stopped jobs"
4095 // On second consecutive 'exit', exit anyway.
4096 if (argv[1] == NULL)
4097 hush_exit(last_return_code);
4098 /* mimic bash: exit 123abc == exit 255 + error msg */
4099 xfunc_error_retval = 255;
4100 /* bash: exit -2 == exit 254, no error msg */
4101 hush_exit(xatoi(argv[1]) & 0xff);
4104 static int builtin_export(char **argv)
4107 char *name = argv[1];
4111 // ash emits: export VAR='VAL'
4112 // bash: declare -x VAR="VAL"
4113 // (both also escape as needed (quotes, $, etc))
4118 return EXIT_SUCCESS;
4121 value = strchr(name, '=');
4123 /* They are exporting something without a =VALUE */
4124 struct variable *var;
4126 var = get_local_var(name);
4128 var->flg_export = 1;
4129 putenv(var->varstr);
4131 /* bash does not return an error when trying to export
4132 * an undefined variable. Do likewise. */
4133 return EXIT_SUCCESS;
4136 set_local_var(xstrdup(name), 1);
4137 return EXIT_SUCCESS;
4141 /* built-in 'fg' and 'bg' handler */
4142 static int builtin_fg_bg(char **argv)
4147 if (!interactive_fd)
4148 return EXIT_FAILURE;
4149 /* If they gave us no args, assume they want the last backgrounded task */
4151 for (pi = job_list; pi; pi = pi->next) {
4152 if (pi->jobid == last_jobid) {
4156 bb_error_msg("%s: no current job", argv[0]);
4157 return EXIT_FAILURE;
4159 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4160 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4161 return EXIT_FAILURE;
4163 for (pi = job_list; pi; pi = pi->next) {
4164 if (pi->jobid == jobnum) {
4168 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4169 return EXIT_FAILURE;
4171 // TODO: bash prints a string representation
4172 // of job being foregrounded (like "sleep 1 | cat")
4173 if (*argv[0] == 'f') {
4174 /* Put the job into the foreground. */
4175 tcsetpgrp(interactive_fd, pi->pgrp);
4178 /* Restart the processes in the job */
4179 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
4180 for (i = 0; i < pi->num_progs; i++) {
4181 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
4182 pi->progs[i].is_stopped = 0;
4184 pi->stopped_progs = 0;
4186 i = kill(- pi->pgrp, SIGCONT);
4188 if (errno == ESRCH) {
4189 delete_finished_bg_job(pi);
4190 return EXIT_SUCCESS;
4192 bb_perror_msg("kill (SIGCONT)");
4196 if (*argv[0] == 'f') {
4198 return checkjobs_and_fg_shell(pi);
4200 return EXIT_SUCCESS;
4204 #if ENABLE_HUSH_HELP
4205 static int builtin_help(char **argv UNUSED_PARAM)
4207 const struct built_in_command *x;
4209 printf("\nBuilt-in commands:\n");
4210 printf("-------------------\n");
4211 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
4212 printf("%s\t%s\n", x->cmd, x->descr);
4215 return EXIT_SUCCESS;
4220 static int builtin_jobs(char **argv UNUSED_PARAM)
4223 const char *status_string;
4225 for (job = job_list; job; job = job->next) {
4226 if (job->alive_progs == job->stopped_progs)
4227 status_string = "Stopped";
4229 status_string = "Running";
4231 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
4233 return EXIT_SUCCESS;
4237 static int builtin_pwd(char **argv UNUSED_PARAM)
4240 return EXIT_SUCCESS;
4243 static int builtin_read(char **argv)
4246 const char *name = argv[1] ? argv[1] : "REPLY";
4248 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
4249 return set_local_var(string, 0);
4252 /* built-in 'set [VAR=value]' handler */
4253 static int builtin_set(char **argv)
4255 char *temp = argv[1];
4259 for (e = top_var; e; e = e->next)
4262 set_local_var(xstrdup(temp), 0);
4264 return EXIT_SUCCESS;
4267 static int builtin_shift(char **argv)
4273 if (n >= 0 && n < global_argc) {
4274 global_argv[n] = global_argv[0];
4277 return EXIT_SUCCESS;
4279 return EXIT_FAILURE;
4282 static int builtin_source(char **argv)
4287 if (argv[1] == NULL)
4288 return EXIT_FAILURE;
4290 /* XXX search through $PATH is missing */
4291 input = fopen(argv[1], "r");
4293 bb_error_msg("cannot open '%s'", argv[1]);
4294 return EXIT_FAILURE;
4296 close_on_exec_on(fileno(input));
4298 /* Now run the file */
4299 /* XXX argv and argc are broken; need to save old global_argv
4300 * (pointer only is OK!) on this stack frame,
4301 * set global_argv=argv+1, recurse, and restore. */
4302 status = parse_and_run_file(input);
4307 static int builtin_umask(char **argv)
4310 const char *arg = argv[1];
4313 new_umask = strtoul(arg, &end, 8);
4314 if (*end != '\0' || end == arg) {
4315 return EXIT_FAILURE;
4318 new_umask = umask(0);
4319 printf("%.3o\n", (unsigned) new_umask);
4322 return EXIT_SUCCESS;
4325 static int builtin_unset(char **argv)
4327 /* bash always returns true */
4328 unset_local_var(argv[1]);
4329 return EXIT_SUCCESS;