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) ATTRIBUTE_NORETURN;
542 static void pseudo_exec(char **ptrs2free, struct child_prog *child) ATTRIBUTE_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 ATTRIBUTE_UNUSED)
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 ATTRIBUTE_UNUSED)
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) ATTRIBUTE_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) ATTRIBUTE_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 ? "vfork" + 1 : "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 ored_ch |= first_ch;
2385 switch (first_ch & 0x7f) {
2386 /* Highest bit in first_ch indicates that var is double-quoted */
2388 val = utoa(root_pid);
2390 case '!': /* bg pid */
2391 val = last_bg_pid ? utoa(last_bg_pid) : (char*)"";
2393 case '?': /* exitcode */
2394 val = utoa(last_return_code);
2396 case '#': /* argc */
2397 val = utoa(global_argc ? global_argc-1 : 0);
2402 if (!global_argv[i])
2404 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2405 smallint sv = output->o_quote;
2406 /* unquoted var's contents should be globbed, so don't quote */
2407 output->o_quote = 0;
2408 while (global_argv[i]) {
2409 n = expand_on_ifs(output, n, global_argv[i]);
2410 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, global_argc-1);
2411 if (global_argv[i++][0] && global_argv[i]) {
2412 /* this argv[] is not empty and not last:
2413 * put terminating NUL, start new word */
2414 o_addchr(output, '\0');
2415 debug_print_list("expand_vars_to_list[2]", output, n);
2416 n = o_save_ptr(output, n);
2417 debug_print_list("expand_vars_to_list[3]", output, n);
2420 output->o_quote = sv;
2422 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2423 * and in this case should treat it like '$*' - see 'else...' below */
2424 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2426 o_addQstr(output, global_argv[i], strlen(global_argv[i]));
2427 if (++i >= global_argc)
2429 o_addchr(output, '\0');
2430 debug_print_list("expand_vars_to_list[4]", output, n);
2431 n = o_save_ptr(output, n);
2433 } else { /* quoted $*: add as one word */
2435 o_addQstr(output, global_argv[i], strlen(global_argv[i]));
2436 if (!global_argv[++i])
2439 o_addchr(output, ifs[0]);
2443 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2444 /* "Empty variable", used to make "" etc to not disappear */
2448 #if ENABLE_HUSH_TICK
2449 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2450 struct in_str input;
2453 //TODO: can we just stuff it into "output" directly?
2454 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2455 setup_string_in_str(&input, arg);
2456 process_command_subs(&subst_result, &input, NULL);
2457 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2458 val = subst_result.data;
2462 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2464 arg[0] = first_ch & 0x7f;
2465 if (isdigit(arg[0])) {
2467 if (i < global_argc)
2468 val = global_argv[i];
2469 /* else val remains NULL: $N with too big N */
2471 val = lookup_param(arg);
2473 #if ENABLE_HUSH_TICK
2476 *p = SPECIAL_VAR_SYMBOL;
2477 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2478 debug_printf_expand("unquoted '%s', output->o_quote:%d\n", val, output->o_quote);
2480 /* unquoted var's contents should be globbed, so don't quote */
2481 smallint sv = output->o_quote;
2482 output->o_quote = 0;
2483 n = expand_on_ifs(output, n, val);
2485 output->o_quote = sv;
2487 } else { /* quoted $VAR, val will be appended below */
2488 debug_printf_expand("quoted '%s', output->o_quote:%d\n", val, output->o_quote);
2492 o_addQstr(output, val, strlen(val));
2495 #if ENABLE_HUSH_TICK
2496 o_free(&subst_result);
2499 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2502 debug_print_list("expand_vars_to_list[a]", output, n);
2503 /* this part is literal, and it was already pre-quoted
2504 * if needed (much earlier), do not use o_addQstr here! */
2505 o_addstr(output, arg, strlen(arg) + 1);
2506 debug_print_list("expand_vars_to_list[b]", output, n);
2507 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2508 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2511 /* allow to reuse list[n] later without re-growth */
2512 output->has_empty_slot = 1;
2514 o_addchr(output, '\0');
2519 static char **expand_variables(char **argv, int or_mask)
2524 o_string output = NULL_O_STRING;
2526 if (or_mask & 0x100) {
2527 output.o_quote = 1; /* protect against globbing for "$var" */
2528 /* (unquoted $var will temporarily switch it off) */
2535 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2538 debug_print_list("expand_variables", &output, n);
2540 /* output.data (malloced in one block) gets returned in "list" */
2541 list = o_finalize_list(&output, n);
2542 debug_print_strings("expand_variables[1]", list);
2546 static char **expand_strvec_to_strvec(char **argv)
2548 return expand_variables(argv, 0x100);
2551 /* Used for expansion of right hand of assignments */
2552 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2554 static char *expand_string_to_string(const char *str)
2556 char *argv[2], **list;
2558 argv[0] = (char*)str;
2560 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2562 if (!list[0] || list[1])
2563 bb_error_msg_and_die("BUG in varexp2");
2564 /* actually, just move string 2*sizeof(char*) bytes back */
2565 strcpy((char*)list, list[0]);
2566 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2570 /* Used for "eval" builtin */
2571 static char* expand_strvec_to_string(char **argv)
2575 list = expand_variables(argv, 0x80);
2576 /* Convert all NULs to spaces */
2581 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2582 bb_error_msg_and_die("BUG in varexp3");
2583 list[n][-1] = ' '; /* TODO: or to ifs[0]? */
2587 strcpy((char*)list, list[0]);
2588 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2593 /* Used to get/check local shell variables */
2594 static struct variable *get_local_var(const char *name)
2596 struct variable *cur;
2602 for (cur = top_var; cur; cur = cur->next) {
2603 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2609 /* str holds "NAME=VAL" and is expected to be malloced.
2610 * We take ownership of it. */
2611 static int set_local_var(char *str, int flg_export)
2613 struct variable *cur;
2617 value = strchr(str, '=');
2618 if (!value) { /* not expected to ever happen? */
2623 name_len = value - str + 1; /* including '=' */
2624 cur = top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
2626 if (strncmp(cur->varstr, str, name_len) != 0) {
2628 /* Bail out. Note that now cur points
2629 * to last var in linked list */
2635 /* We found an existing var with this name */
2637 if (cur->flg_read_only) {
2638 bb_error_msg("%s: readonly variable", str);
2642 unsetenv(str); /* just in case */
2644 if (strcmp(cur->varstr, str) == 0) {
2649 if (cur->max_len >= strlen(str)) {
2650 /* This one is from startup env, reuse space */
2651 strcpy(cur->varstr, str);
2654 /* max_len == 0 signifies "malloced" var, which we can
2655 * (and has to) free */
2659 goto set_str_and_exp;
2662 /* Not found - create next variable struct */
2663 cur->next = xzalloc(sizeof(*cur));
2670 cur->flg_export = 1;
2671 if (cur->flg_export)
2672 return putenv(cur->varstr);
2676 static void unset_local_var(const char *name)
2678 struct variable *cur;
2679 struct variable *prev = prev; /* for gcc */
2684 name_len = strlen(name);
2687 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2688 if (cur->flg_read_only) {
2689 bb_error_msg("%s: readonly variable", name);
2692 /* prev is ok to use here because 1st variable, HUSH_VERSION,
2693 * is ro, and we cannot reach this code on the 1st pass */
2694 prev->next = cur->next;
2695 unsetenv(cur->varstr);
2706 /* the src parameter allows us to peek forward to a possible &n syntax
2707 * for file descriptor duplication, e.g., "2>&1".
2708 * Return code is 0 normally, 1 if a syntax error is detected in src.
2709 * Resource errors (in xmalloc) cause the process to exit */
2710 static int setup_redirect(struct p_context *ctx, int fd, redir_type style,
2711 struct in_str *input)
2713 struct child_prog *child = ctx->child;
2714 struct redir_struct *redir = child->redirects;
2715 struct redir_struct *last_redir = NULL;
2717 /* Create a new redir_struct and drop it onto the end of the linked list */
2720 redir = redir->next;
2722 redir = xzalloc(sizeof(struct redir_struct));
2723 /* redir->next = NULL; */
2724 /* redir->rd_filename = NULL; */
2726 last_redir->next = redir;
2728 child->redirects = redir;
2731 redir->rd_type = style;
2732 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
2734 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
2736 /* Check for a '2>&1' type redirect */
2737 redir->dup = redirect_dup_num(input);
2738 if (redir->dup == -2)
2739 return 1; /* syntax error */
2740 if (redir->dup != -1) {
2741 /* Erik had a check here that the file descriptor in question
2742 * is legit; I postpone that to "run time"
2743 * A "-" representation of "close me" shows up as a -3 here */
2744 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
2746 /* We do _not_ try to open the file that src points to,
2747 * since we need to return and let src be expanded first.
2748 * Set ctx->pending_redirect, so we know what to do at the
2749 * end of the next parsed word. */
2750 ctx->pending_redirect = redir;
2755 static struct pipe *new_pipe(void)
2758 pi = xzalloc(sizeof(struct pipe));
2759 /*pi->followup = 0; - deliberately invalid value */
2760 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2764 static void initialize_context(struct p_context *ctx)
2766 memset(ctx, 0, sizeof(*ctx));
2767 ctx->pipe = ctx->list_head = new_pipe();
2768 /* Create the memory for child, roughly:
2769 * ctx->pipe->progs = new struct child_prog;
2770 * ctx->pipe->progs[0].family = ctx->pipe;
2771 * ctx->child = &ctx->pipe->progs[0];
2776 /* If a reserved word is found and processed, parse context is modified
2777 * and 1 is returned.
2778 * Handles if, then, elif, else, fi, for, while, until, do, done.
2779 * case, function, and select are obnoxious, save those for later.
2782 static int reserved_word(const o_string *word, struct p_context *ctx)
2784 struct reserved_combo {
2790 FLAG_END = (1 << RES_NONE ),
2792 FLAG_IF = (1 << RES_IF ),
2793 FLAG_THEN = (1 << RES_THEN ),
2794 FLAG_ELIF = (1 << RES_ELIF ),
2795 FLAG_ELSE = (1 << RES_ELSE ),
2796 FLAG_FI = (1 << RES_FI ),
2798 #if ENABLE_HUSH_LOOPS
2799 FLAG_FOR = (1 << RES_FOR ),
2800 FLAG_WHILE = (1 << RES_WHILE),
2801 FLAG_UNTIL = (1 << RES_UNTIL),
2802 FLAG_DO = (1 << RES_DO ),
2803 FLAG_DONE = (1 << RES_DONE ),
2804 FLAG_IN = (1 << RES_IN ),
2806 FLAG_START = (1 << RES_XXXX ),
2808 /* Mostly a list of accepted follow-up reserved words.
2809 * FLAG_END means we are done with the sequence, and are ready
2810 * to turn the compound list into a command.
2811 * FLAG_START means the word must start a new compound list.
2813 static const struct reserved_combo reserved_list[] = {
2815 { "!", RES_NONE, 0 },
2816 { "if", RES_IF, FLAG_THEN | FLAG_START },
2817 { "then", RES_THEN, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2818 { "elif", RES_ELIF, FLAG_THEN },
2819 { "else", RES_ELSE, FLAG_FI },
2820 { "fi", RES_FI, FLAG_END },
2822 #if ENABLE_HUSH_LOOPS
2823 { "for", RES_FOR, FLAG_IN | FLAG_START },
2824 { "while", RES_WHILE, FLAG_DO | FLAG_START },
2825 { "until", RES_UNTIL, FLAG_DO | FLAG_START },
2826 { "in", RES_IN, FLAG_DO },
2827 { "do", RES_DO, FLAG_DONE },
2828 { "done", RES_DONE, FLAG_END }
2832 const struct reserved_combo *r;
2834 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2835 if (strcmp(word->data, r->literal) != 0)
2837 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2838 if (r->flag == 0) { /* '!' */
2839 #if ENABLE_HUSH_LOOPS
2840 if (ctx->ctx_res_w == RES_IN) {
2841 /* 'for a in ! a b c; ...' - ! isn't a keyword here */
2845 if (ctx->ctx_inverted /* bash doesn't accept '! ! true' */
2846 #if ENABLE_HUSH_LOOPS
2847 || ctx->ctx_res_w == RES_FOR /* example: 'for ! a' */
2851 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
2853 ctx->ctx_inverted = 1;
2856 if (r->flag & FLAG_START) {
2857 struct p_context *new;
2858 debug_printf("push stack\n");
2859 #if ENABLE_HUSH_LOOPS
2860 if (ctx->ctx_res_w == RES_IN || ctx->ctx_res_w == RES_FOR) {
2861 syntax("malformed for"); /* example: 'for if' */
2862 ctx->ctx_res_w = RES_SNTX;
2866 new = xmalloc(sizeof(*new));
2867 *new = *ctx; /* physical copy */
2868 initialize_context(ctx);
2870 } else if (ctx->ctx_res_w == RES_NONE || !(ctx->old_flag & (1 << r->res))) {
2872 ctx->ctx_res_w = RES_SNTX;
2875 ctx->ctx_res_w = r->res;
2876 ctx->old_flag = r->flag;
2877 if (ctx->old_flag & FLAG_END) {
2878 struct p_context *old;
2879 debug_printf("pop stack\n");
2880 done_pipe(ctx, PIPE_SEQ);
2882 old->child->group = ctx->list_head;
2883 old->child->subshell = 0;
2884 *ctx = *old; /* physical copy */
2893 /* Word is complete, look at it and update parsing context.
2894 * Normal return is 0. Syntax errors return 1. */
2895 static int done_word(o_string *word, struct p_context *ctx)
2897 struct child_prog *child = ctx->child;
2899 /* If this word wasn't an assignment, next ones definitely
2900 * can't be assignments. Even if they look like ones. */
2901 if (word->o_assignment != DEFINITELY_ASSIGNMENT) {
2902 word->o_assignment = NOT_ASSIGNMENT;
2904 word->o_assignment = MAYBE_ASSIGNMENT;
2907 debug_printf_parse("done_word entered: '%s' %p\n", word->data, child);
2908 if (word->length == 0 && word->nonnull == 0) {
2909 debug_printf_parse("done_word return 0: true null, ignored\n");
2912 if (ctx->pending_redirect) {
2913 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
2914 * only if run as "bash", not "sh" */
2915 ctx->pending_redirect->rd_filename = xstrdup(word->data);
2916 word->o_assignment = NOT_ASSIGNMENT;
2917 debug_printf("word stored in rd_filename: '%s'\n", word->data);
2919 if (child->group) { /* TODO: example how to trigger? */
2921 debug_printf_parse("done_word return 1: syntax error, groups and arglists don't mix\n");
2925 if (!child->argv) { /* if it's the first word... */
2926 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
2927 if (reserved_word(word, ctx)) {
2929 word->o_assignment = NOT_ASSIGNMENT;
2930 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
2931 return (ctx->ctx_res_w == RES_SNTX);
2935 if (word->nonnull /* we saw "xx" or 'xx' */
2936 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
2937 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
2938 /* (otherwise it's "abc".... and is already safe) */
2940 /* Insert "empty variable" reference, this makes
2941 * e.g. "", $empty"" etc to not disappear */
2942 o_addchr(word, SPECIAL_VAR_SYMBOL);
2943 o_addchr(word, SPECIAL_VAR_SYMBOL);
2945 child->argv = add_malloced_string_to_strings(child->argv, xstrdup(word->data));
2946 debug_print_strings("word appended to argv", child->argv);
2950 ctx->pending_redirect = NULL;
2952 #if ENABLE_HUSH_LOOPS
2953 /* Force FOR to have just one word (variable name) */
2954 if (ctx->ctx_res_w == RES_FOR)
2955 done_pipe(ctx, PIPE_SEQ);
2957 debug_printf_parse("done_word return 0\n");
2961 /* Command (member of a pipe) is complete. The only possible error here
2962 * is out of memory, in which case xmalloc exits. */
2963 static int done_command(struct p_context *ctx)
2965 /* The child is really already in the pipe structure, so
2966 * advance the pipe counter and make a new, null child. */
2967 struct pipe *pi = ctx->pipe;
2968 struct child_prog *child = ctx->child;
2971 if (child->group == NULL
2972 && child->argv == NULL
2973 && child->redirects == NULL
2975 debug_printf_parse("done_command: skipping null cmd, num_progs=%d\n", pi->num_progs);
2976 return pi->num_progs;
2979 debug_printf_parse("done_command: ++num_progs=%d\n", pi->num_progs);
2981 debug_printf_parse("done_command: initializing, num_progs=%d\n", pi->num_progs);
2984 /* Only real trickiness here is that the uncommitted
2985 * child structure is not counted in pi->num_progs. */
2986 pi->progs = xrealloc(pi->progs, sizeof(*pi->progs) * (pi->num_progs+1));
2987 child = &pi->progs[pi->num_progs];
2989 memset(child, 0, sizeof(*child));
2993 /* but ctx->pipe and ctx->list_head remain unchanged */
2995 return pi->num_progs; /* used only for 0/nonzero check */
2998 static void done_pipe(struct p_context *ctx, pipe_style type)
3002 debug_printf_parse("done_pipe entered, followup %d\n", type);
3003 not_null = done_command(ctx); /* implicit closure of previous command */
3004 ctx->pipe->followup = type;
3005 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3006 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3007 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3008 /* Without this check, even just <enter> on command line generates
3009 * tree of three NOPs (!). Which is harmless but annoying.
3010 * IOW: it is safe to do it unconditionally.
3011 * RES_IN case is for "for a in; do ..." (empty IN set)
3013 if (not_null USE_HUSH_LOOPS(|| ctx->pipe->res_word == RES_IN)) {
3014 struct pipe *new_p = new_pipe();
3015 ctx->pipe->next = new_p;
3017 ctx->child = NULL; /* needed! */
3018 /* Create the memory for child, roughly:
3019 * ctx->pipe->progs = new struct child_prog;
3020 * ctx->pipe->progs[0].family = ctx->pipe;
3021 * ctx->child = &ctx->pipe->progs[0];
3025 debug_printf_parse("done_pipe return\n");
3028 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3029 * as in "2>&1", that represents duplicating a file descriptor.
3030 * Return either -2 (syntax error), -1 (no &), or the number found.
3032 static int redirect_dup_num(struct in_str *input)
3034 int ch, d = 0, ok = 0;
3036 if (ch != '&') return -1;
3038 i_getch(input); /* get the & */
3042 return -3; /* "-" represents "close me" */
3044 while (isdigit(ch)) {
3045 d = d*10 + (ch-'0');
3052 bb_error_msg("ambiguous redirect");
3056 /* If a redirect is immediately preceded by a number, that number is
3057 * supposed to tell which file descriptor to redirect. This routine
3058 * looks for such preceding numbers. In an ideal world this routine
3059 * needs to handle all the following classes of redirects...
3060 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3061 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3062 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3063 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3064 * A -1 output from this program means no valid number was found, so the
3065 * caller should use the appropriate default for this redirection.
3067 static int redirect_opt_num(o_string *o)
3073 for (num = 0; num < o->length; num++) {
3074 if (!isdigit(o->data[num])) {
3078 num = atoi(o->data);
3083 #if ENABLE_HUSH_TICK
3084 static FILE *generate_stream_from_list(struct pipe *head)
3087 int pid, channel[2];
3090 /* *** NOMMU WARNING *** */
3091 /* By using vfork here, we suspend parent till child exits or execs.
3092 * If child will not do it before it fills the pipe, it can block forever
3093 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3095 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3096 * huge=`cat TESTFILE` # will block here forever
3099 pid = BB_MMU ? xfork() : xvfork();
3100 if (pid == 0) { /* child */
3101 if (ENABLE_HUSH_JOB)
3102 die_sleep = 0; /* let nofork's xfuncs die */
3103 close(channel[0]); /* NB: close _first_, then move fd! */
3104 xmove_fd(channel[1], 1);
3105 /* Prevent it from trying to handle ctrl-z etc */
3109 /* Process substitution is not considered to be usual
3110 * 'command execution'.
3111 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
3112 /* Not needed, we are relying on it being disabled
3113 * everywhere outside actual command execution. */
3114 /*set_jobctrl_sighandler(SIG_IGN);*/
3115 set_misc_sighandler(SIG_DFL);
3116 /* Freeing 'head' here would break NOMMU. */
3117 _exit(run_list(head));
3120 pf = fdopen(channel[0], "r");
3122 /* 'head' is freed by the caller */
3125 /* Return code is exit status of the process that is run. */
3126 static int process_command_subs(o_string *dest,
3127 struct in_str *input,
3128 const char *subst_end)
3130 int retcode, ch, eol_cnt;
3131 o_string result = NULL_O_STRING;
3132 struct p_context inner;
3134 struct in_str pipe_str;
3136 initialize_context(&inner);
3138 /* Recursion to generate command */
3139 retcode = parse_stream(&result, &inner, input, subst_end);
3141 return retcode; /* syntax error or EOF */
3142 done_word(&result, &inner);
3143 done_pipe(&inner, PIPE_SEQ);
3146 p = generate_stream_from_list(inner.list_head);
3149 close_on_exec_on(fileno(p));
3150 setup_file_in_str(&pipe_str, p);
3152 /* Now send results of command back into original context */
3154 while ((ch = i_getch(&pipe_str)) != EOF) {
3160 o_addchr(dest, '\n');
3163 // /* Even unquoted `echo '\'` results in two backslashes
3164 // * (which are converted into one by globbing later) */
3165 // if (!dest->o_quote && ch == '\\') {
3166 // o_addchr(dest, ch);
3168 o_addQchr(dest, ch);
3171 debug_printf("done reading from pipe, pclose()ing\n");
3172 /* This is the step that wait()s for the child. Should be pretty
3173 * safe, since we just read an EOF from its stdout. We could try
3174 * to do better, by using wait(), and keeping track of background jobs
3175 * at the same time. That would be a lot of work, and contrary
3176 * to the KISS philosophy of this program. */
3177 retcode = fclose(p);
3178 free_pipe_list(inner.list_head, /* indent: */ 0);
3179 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3184 static int parse_group(o_string *dest, struct p_context *ctx,
3185 struct in_str *input, int ch)
3188 const char *endch = NULL;
3189 struct p_context sub;
3190 struct child_prog *child = ctx->child;
3192 debug_printf_parse("parse_group entered\n");
3195 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3198 initialize_context(&sub);
3202 child->subshell = 1;
3204 rcode = parse_stream(dest, &sub, input, endch);
3206 done_word(dest, &sub); /* finish off the final word in the subcontext */
3207 done_pipe(&sub, PIPE_SEQ); /* and the final command there, too */
3208 child->group = sub.list_head;
3210 debug_printf_parse("parse_group return %d\n", rcode);
3212 /* child remains "open", available for possible redirects */
3215 /* Basically useful version until someone wants to get fancier,
3216 * see the bash man page under "Parameter Expansion" */
3217 static const char *lookup_param(const char *src)
3219 struct variable *var = get_local_var(src);
3221 return strchr(var->varstr, '=') + 1;
3225 #if ENABLE_HUSH_TICK
3226 /* Subroutines for copying $(...) and `...` things */
3227 static void add_till_backquote(o_string *dest, struct in_str *input);
3229 static void add_till_single_quote(o_string *dest, struct in_str *input)
3232 int ch = i_getch(input);
3240 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3241 static void add_till_double_quote(o_string *dest, struct in_str *input)
3244 int ch = i_getch(input);
3247 if (ch == '\\') { /* \x. Copy both chars. */
3249 ch = i_getch(input);
3255 add_till_backquote(dest, input);
3259 //if (ch == '$') ...
3262 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3264 * "Within the backquoted style of command substitution, backslash
3265 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3266 * The search for the matching backquote shall be satisfied by the first
3267 * backquote found without a preceding backslash; during this search,
3268 * if a non-escaped backquote is encountered within a shell comment,
3269 * a here-document, an embedded command substitution of the $(command)
3270 * form, or a quoted string, undefined results occur. A single-quoted
3271 * or double-quoted string that begins, but does not end, within the
3272 * "`...`" sequence produces undefined results."
3274 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3276 static void add_till_backquote(o_string *dest, struct in_str *input)
3279 int ch = i_getch(input);
3282 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3283 int ch2 = i_getch(input);
3284 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3293 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3294 * quoting and nested ()s.
3295 * "With the $(command) style of command substitution, all characters
3296 * following the open parenthesis to the matching closing parenthesis
3297 * constitute the command. Any valid shell script can be used for command,
3298 * except a script consisting solely of redirections which produces
3299 * unspecified results."
3301 * echo $(echo '(TEST)' BEST) (TEST) BEST
3302 * echo $(echo 'TEST)' BEST) TEST) BEST
3303 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3305 static void add_till_closing_curly_brace(o_string *dest, struct in_str *input)
3309 int ch = i_getch(input);
3319 add_till_single_quote(dest, input);
3324 add_till_double_quote(dest, input);
3328 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3329 ch = i_getch(input);
3337 #endif /* ENABLE_HUSH_TICK */
3339 /* Return code: 0 for OK, 1 for syntax error */
3340 static int handle_dollar(o_string *dest, struct in_str *input)
3342 int ch = i_peek(input); /* first character after the $ */
3343 unsigned char quote_mask = dest->o_quote ? 0x80 : 0;
3345 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3347 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3349 debug_printf_parse(": '%c'\n", ch);
3351 o_addchr(dest, ch | quote_mask);
3354 if (!isalnum(ch) && ch != '_')
3357 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3358 } else if (isdigit(ch)) {
3360 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3361 debug_printf_parse(": '%c'\n", ch);
3363 o_addchr(dest, ch | quote_mask);
3364 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3365 } else switch (ch) {
3367 case '!': /* last bg pid */
3368 case '?': /* last exit code */
3369 case '#': /* number of args */
3370 case '*': /* args */
3371 case '@': /* args */
3372 goto make_one_char_var;
3374 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3376 /* XXX maybe someone will try to escape the '}' */
3378 ch = i_getch(input);
3381 if (!isalnum(ch) && ch != '_') {
3382 syntax("unterminated ${name}");
3383 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
3386 debug_printf_parse(": '%c'\n", ch);
3387 o_addchr(dest, ch | quote_mask);
3390 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3392 #if ENABLE_HUSH_TICK
3394 //int pos = dest->length;
3396 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3397 o_addchr(dest, quote_mask | '`');
3398 add_till_closing_curly_brace(dest, input);
3399 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
3400 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3406 /* still unhandled, but should be eventually */
3407 bb_error_msg("unhandled syntax: $%c", ch);
3411 o_addQchr(dest, '$');
3413 debug_printf_parse("handle_dollar return 0\n");
3417 /* Scan input, call done_word() whenever full IFS delemited word was seen.
3418 * call done_pipe if '\n' was seen (and end_trigger != NULL)
3419 * Return if (non-quoted) char in end_trigger was seen; or on parse error. */
3420 /* Return code is 0 if end_trigger char is met,
3421 * -1 on EOF (but if end_trigger == NULL then return 0)
3422 * 1 for syntax error */
3423 static int parse_stream(o_string *dest, struct p_context *ctx,
3424 struct in_str *input, const char *end_trigger)
3428 redir_type redir_style;
3429 int shadow_quote = dest->o_quote;
3432 /* Only double-quote state is handled in the state variable dest->o_quote.
3433 * A single-quote triggers a bypass of the main loop until its mate is
3434 * found. When recursing, quote state is passed in via dest->o_quote. */
3436 debug_printf_parse("parse_stream entered, end_trigger='%s'\n", end_trigger);
3441 ch = i_getch(input);
3445 next = i_peek(input);
3448 debug_printf_parse(": ch=%c (%d) m=%d quote=%d\n",
3449 ch, ch, m, dest->o_quote);
3450 if (m == CHAR_ORDINARY
3451 || (m != CHAR_SPECIAL && shadow_quote)
3454 syntax("unterminated \"");
3455 debug_printf_parse("parse_stream return 1: unterminated \"\n");
3458 o_addQchr(dest, ch);
3459 if (dest->o_assignment == MAYBE_ASSIGNMENT
3461 && is_assignment(dest->data)
3463 dest->o_assignment = DEFINITELY_ASSIGNMENT;
3467 if (m == CHAR_IFS) {
3468 if (done_word(dest, ctx)) {
3469 debug_printf_parse("parse_stream return 1: done_word!=0\n");
3474 /* If we aren't performing a substitution, treat
3475 * a newline as a command separator.
3476 * [why we don't handle it exactly like ';'? --vda] */
3477 if (end_trigger && ch == '\n') {
3478 done_pipe(ctx, PIPE_SEQ);
3482 if (!shadow_quote && strchr(end_trigger, ch)) {
3483 /* Special case: (...word) makes last word terminate,
3484 * as if ';' is seen */
3486 done_word(dest, ctx);
3488 done_pipe(ctx, PIPE_SEQ);
3490 if (!HAS_KEYWORDS IF_HAS_KEYWORDS(|| ctx->ctx_res_w == RES_NONE)) {
3491 debug_printf_parse("parse_stream return 0: end_trigger char found\n");
3499 if (dest->o_assignment == MAYBE_ASSIGNMENT) {
3500 /* ch is a special char and thus this word
3501 * cannot be an assignment: */
3502 dest->o_assignment = NOT_ASSIGNMENT;
3507 if (dest->length == 0 && !shadow_quote) {
3510 if (ch == EOF || ch == '\n')
3515 o_addQchr(dest, ch);
3521 debug_printf_parse("parse_stream return 1: \\<eof>\n");
3525 * "The backslash retains its special meaning [in "..."]
3526 * only when followed by one of the following characters:
3527 * $, `, ", \, or <newline>. A double quote may be quoted
3528 * within double quotes by preceding it with a backslash.
3529 * If enabled, history expansion will be performed unless
3530 * an ! appearing in double quotes is escaped using
3531 * a backslash. The backslash preceding the ! is not removed."
3533 if (shadow_quote) { //NOT SURE dest->o_quote) {
3534 if (strchr("$`\"\\", next) != NULL) {
3535 o_addqchr(dest, i_getch(input));
3537 o_addqchr(dest, '\\');
3540 o_addchr(dest, '\\');
3541 o_addchr(dest, i_getch(input));
3545 if (handle_dollar(dest, input) != 0) {
3546 debug_printf_parse("parse_stream return 1: handle_dollar returned non-0\n");
3553 ch = i_getch(input);
3555 syntax("unterminated '");
3556 debug_printf_parse("parse_stream return 1: unterminated '\n");
3561 if (dest->o_assignment == NOT_ASSIGNMENT)
3562 o_addqchr(dest, ch);
3569 shadow_quote ^= 1; /* invert */
3570 if (dest->o_assignment == NOT_ASSIGNMENT)
3573 #if ENABLE_HUSH_TICK
3575 //int pos = dest->length;
3576 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3577 o_addchr(dest, shadow_quote /*or dest->o_quote??*/ ? 0x80 | '`' : '`');
3578 add_till_backquote(dest, input);
3579 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3580 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3585 redir_fd = redirect_opt_num(dest);
3586 done_word(dest, ctx);
3587 redir_style = REDIRECT_OVERWRITE;
3589 redir_style = REDIRECT_APPEND;
3593 else if (next == '(') {
3594 syntax(">(process) not supported");
3595 debug_printf_parse("parse_stream return 1: >(process) not supported\n");
3599 setup_redirect(ctx, redir_fd, redir_style, input);
3602 redir_fd = redirect_opt_num(dest);
3603 done_word(dest, ctx);
3604 redir_style = REDIRECT_INPUT;
3606 redir_style = REDIRECT_HEREIS;
3608 } else if (next == '>') {
3609 redir_style = REDIRECT_IO;
3613 else if (next == '(') {
3614 syntax("<(process) not supported");
3615 debug_printf_parse("parse_stream return 1: <(process) not supported\n");
3619 setup_redirect(ctx, redir_fd, redir_style, input);
3622 done_word(dest, ctx);
3623 done_pipe(ctx, PIPE_SEQ);
3626 done_word(dest, ctx);
3629 done_pipe(ctx, PIPE_AND);
3631 done_pipe(ctx, PIPE_BG);
3635 done_word(dest, ctx);
3638 done_pipe(ctx, PIPE_OR);
3640 /* we could pick up a file descriptor choice here
3641 * with redirect_opt_num(), but bash doesn't do it.
3642 * "echo foo 2| cat" yields "foo 2". */
3648 if (parse_group(dest, ctx, input, ch) != 0) {
3649 debug_printf_parse("parse_stream return 1: parse_group returned non-0\n");
3655 /* proper use of this character is caught by end_trigger */
3656 syntax("unexpected } or )");
3657 debug_printf_parse("parse_stream return 1: unexpected '}'\n");
3661 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
3664 debug_printf_parse("parse_stream return %d\n", -(end_trigger != NULL));
3670 static void set_in_charmap(const char *set, int code)
3673 charmap[(unsigned char)*set++] = code;
3676 static void update_charmap(void)
3678 /* char *ifs and char charmap[256] are both globals. */
3679 ifs = getenv("IFS");
3682 /* Precompute a list of 'flow through' behavior so it can be treated
3683 * quickly up front. Computation is necessary because of IFS.
3684 * Special case handling of IFS == " \t\n" is not implemented.
3685 * The charmap[] array only really needs two bits each,
3686 * and on most machines that would be faster (reduced L1 cache use).
3688 memset(charmap, CHAR_ORDINARY, sizeof(charmap));
3689 #if ENABLE_HUSH_TICK
3690 set_in_charmap("\\$\"`", CHAR_SPECIAL);
3692 set_in_charmap("\\$\"", CHAR_SPECIAL);
3694 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
3695 set_in_charmap(ifs, CHAR_IFS); /* are ordinary if quoted */
3698 /* Most recursion does not come through here, the exception is
3699 * from builtin_source() and builtin_eval() */
3700 static int parse_and_run_stream(struct in_str *inp, int parse_flag)
3702 struct p_context ctx;
3703 o_string temp = NULL_O_STRING;
3707 initialize_context(&ctx);
3709 #if ENABLE_HUSH_INTERACTIVE
3710 inp->promptmode = 0; /* PS1 */
3712 /* We will stop & execute after each ';' or '\n'.
3713 * Example: "sleep 9999; echo TEST" + ctrl-C:
3714 * TEST should be printed */
3715 rcode = parse_stream(&temp, &ctx, inp, ";\n");
3717 if (rcode != 1 && ctx.old_flag != 0) {
3721 if (rcode != 1 IF_HAS_KEYWORDS(&& ctx.old_flag == 0)) {
3722 done_word(&temp, &ctx);
3723 done_pipe(&ctx, PIPE_SEQ);
3724 debug_print_tree(ctx.list_head, 0);
3725 debug_printf_exec("parse_stream_outer: run_and_free_list\n");
3726 run_and_free_list(ctx.list_head);
3728 /* We arrive here also if rcode == 1 (error in parse_stream) */
3730 if (ctx.old_flag != 0) {
3735 /*temp.nonnull = 0; - o_free does it below */
3736 /*temp.o_quote = 0; - o_free does it below */
3737 free_pipe_list(ctx.list_head, /* indent: */ 0);
3738 /* Discard all unprocessed line input, force prompt on */
3740 #if ENABLE_HUSH_INTERACTIVE
3745 /* loop on syntax errors, return on EOF: */
3746 } while (rcode != -1 && !(parse_flag & PARSEFLAG_EXIT_FROM_LOOP));
3750 static int parse_and_run_string(const char *s, int parse_flag)
3752 struct in_str input;
3753 setup_string_in_str(&input, s);
3754 return parse_and_run_stream(&input, parse_flag);
3757 static int parse_and_run_file(FILE *f)
3760 struct in_str input;
3761 setup_file_in_str(&input, f);
3762 rcode = parse_and_run_stream(&input, 0 /* parse_flag */);
3767 /* Make sure we have a controlling tty. If we get started under a job
3768 * aware app (like bash for example), make sure we are now in charge so
3769 * we don't fight over who gets the foreground */
3770 static void setup_job_control(void)
3774 saved_task_pgrp = shell_pgrp = getpgrp();
3775 debug_printf_jobs("saved_task_pgrp=%d\n", saved_task_pgrp);
3776 close_on_exec_on(interactive_fd);
3778 /* If we were ran as 'hush &',
3779 * sleep until we are in the foreground. */
3780 while (tcgetpgrp(interactive_fd) != shell_pgrp) {
3781 /* Send TTIN to ourself (should stop us) */
3782 kill(- shell_pgrp, SIGTTIN);
3783 shell_pgrp = getpgrp();
3786 /* Ignore job-control and misc signals. */
3787 set_jobctrl_sighandler(SIG_IGN);
3788 set_misc_sighandler(SIG_IGN);
3789 //huh? signal(SIGCHLD, SIG_IGN);
3791 /* We _must_ restore tty pgrp on fatal signals */
3792 set_fatal_sighandler(sigexit);
3794 /* Put ourselves in our own process group. */
3795 setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
3796 /* Grab control of the terminal. */
3797 tcsetpgrp(interactive_fd, getpid());
3802 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3803 int hush_main(int argc, char **argv)
3805 static const char version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
3806 static const struct variable const_shell_ver = {
3808 .varstr = (char*)version_str,
3809 .max_len = 1, /* 0 can provoke free(name) */
3817 struct variable *cur_var;
3821 root_pid = getpid();
3823 /* Deal with HUSH_VERSION */
3824 shell_ver = const_shell_ver; /* copying struct here */
3825 top_var = &shell_ver;
3826 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
3827 /* Initialize our shell local variables with the values
3828 * currently living in the environment */
3832 char *value = strchr(*e, '=');
3833 if (value) { /* paranoia */
3834 cur_var->next = xzalloc(sizeof(*cur_var));
3835 cur_var = cur_var->next;
3836 cur_var->varstr = *e;
3837 cur_var->max_len = strlen(*e);
3838 cur_var->flg_export = 1;
3842 putenv((char *)version_str); /* reinstate HUSH_VERSION */
3844 #if ENABLE_FEATURE_EDITING
3845 line_input_state = new_line_input_t(FOR_SHELL);
3847 /* XXX what should these be while sourcing /etc/profile? */
3850 /* Initialize some more globals to non-zero values */
3852 #if ENABLE_HUSH_INTERACTIVE
3853 #if ENABLE_FEATURE_EDITING
3854 cmdedit_set_initial_prompt();
3859 if (EXIT_SUCCESS) /* otherwise is already done */
3860 last_return_code = EXIT_SUCCESS;
3862 if (argv[0] && argv[0][0] == '-') {
3863 debug_printf("sourcing /etc/profile\n");
3864 input = fopen("/etc/profile", "r");
3865 if (input != NULL) {
3866 close_on_exec_on(fileno(input));
3867 parse_and_run_file(input);
3873 while ((opt = getopt(argc, argv, "c:xif")) > 0) {
3876 global_argv = argv + optind;
3877 global_argc = argc - optind;
3878 opt = parse_and_run_string(optarg, 0 /* parse_flag */);
3881 /* Well, we cannot just declare interactiveness,
3882 * we have to have some stuff (ctty, etc) */
3883 /* interactive_fd++; */
3890 fprintf(stderr, "Usage: sh [FILE]...\n"
3891 " or: sh -c command [args]...\n\n");
3899 /* A shell is interactive if the '-i' flag was given, or if all of
3900 * the following conditions are met:
3902 * no arguments remaining or the -s flag given
3903 * standard input is a terminal
3904 * standard output is a terminal
3905 * Refer to Posix.2, the description of the 'sh' utility. */
3906 if (argv[optind] == NULL && input == stdin
3907 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3909 saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
3910 debug_printf("saved_tty_pgrp=%d\n", saved_tty_pgrp);
3911 if (saved_tty_pgrp >= 0) {
3912 /* try to dup to high fd#, >= 255 */
3913 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3914 if (interactive_fd < 0) {
3915 /* try to dup to any fd */
3916 interactive_fd = dup(STDIN_FILENO);
3917 if (interactive_fd < 0)
3921 // TODO: track & disallow any attempts of user
3922 // to (inadvertently) close/redirect it
3925 debug_printf("interactive_fd=%d\n", interactive_fd);
3926 if (interactive_fd) {
3927 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3928 /* Looks like they want an interactive shell */
3929 setup_job_control();
3930 /* -1 is special - makes xfuncs longjmp, not exit
3931 * (we reset die_sleep = 0 whereever we [v]fork) */
3933 if (setjmp(die_jmp)) {
3934 /* xfunc has failed! die die die */
3935 hush_exit(xfunc_error_retval);
3937 #if !ENABLE_FEATURE_SH_EXTRA_QUIET
3938 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
3939 printf("Enter 'help' for a list of built-in commands.\n\n");
3942 #elif ENABLE_HUSH_INTERACTIVE
3943 /* no job control compiled, only prompt/line editing */
3944 if (argv[optind] == NULL && input == stdin
3945 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
3947 interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
3948 if (interactive_fd < 0) {
3949 /* try to dup to any fd */
3950 interactive_fd = dup(STDIN_FILENO);
3951 if (interactive_fd < 0)
3955 if (interactive_fd) {
3956 fcntl(interactive_fd, F_SETFD, FD_CLOEXEC);
3957 set_misc_sighandler(SIG_IGN);
3962 if (argv[optind] == NULL) {
3963 opt = parse_and_run_file(stdin);
3965 debug_printf("\nrunning script '%s'\n", argv[optind]);
3966 global_argv = argv + optind;
3967 global_argc = argc - optind;
3968 input = xfopen(argv[optind], "r");
3969 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
3970 opt = parse_and_run_file(input);
3975 #if ENABLE_FEATURE_CLEAN_UP
3977 if (cwd != bb_msg_unknown)
3979 cur_var = top_var->next;
3981 struct variable *tmp = cur_var;
3982 if (!cur_var->max_len)
3983 free(cur_var->varstr);
3984 cur_var = cur_var->next;
3988 hush_exit(opt ? opt : last_return_code);
3993 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
3994 int lash_main(int argc, char **argv)
3996 //bb_error_msg("lash is deprecated, please use hush instead");
3997 return hush_main(argc, argv);
4005 static int builtin_true(char **argv ATTRIBUTE_UNUSED)
4010 static int builtin_test(char **argv)
4017 return test_main(argc, argv - argc);
4020 static int builtin_echo(char **argv)
4027 return echo_main(argc, argv - argc);
4030 static int builtin_eval(char **argv)
4032 int rcode = EXIT_SUCCESS;
4035 char *str = expand_strvec_to_string(argv + 1);
4036 parse_and_run_string(str, PARSEFLAG_EXIT_FROM_LOOP);
4038 rcode = last_return_code;
4043 static int builtin_cd(char **argv)
4046 if (argv[1] == NULL) {
4047 // bash does nothing (exitcode 0) if HOME is ""; if it's unset,
4048 // bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
4049 newdir = getenv("HOME") ? : "/";
4052 if (chdir(newdir)) {
4053 printf("cd: %s: %s\n", newdir, strerror(errno));
4054 return EXIT_FAILURE;
4057 return EXIT_SUCCESS;
4060 static int builtin_exec(char **argv)
4062 if (argv[1] == NULL)
4063 return EXIT_SUCCESS; /* bash does this */
4066 char **ptrs2free = alloc_ptrs(argv);
4068 // FIXME: if exec fails, bash does NOT exit! We do...
4069 pseudo_exec_argv(ptrs2free, argv + 1);
4074 static int builtin_exit(char **argv)
4076 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
4077 //puts("exit"); /* bash does it */
4078 // TODO: warn if we have background jobs: "There are stopped jobs"
4079 // On second consecutive 'exit', exit anyway.
4080 if (argv[1] == NULL)
4081 hush_exit(last_return_code);
4082 /* mimic bash: exit 123abc == exit 255 + error msg */
4083 xfunc_error_retval = 255;
4084 /* bash: exit -2 == exit 254, no error msg */
4085 hush_exit(xatoi(argv[1]) & 0xff);
4088 static int builtin_export(char **argv)
4091 char *name = argv[1];
4095 // ash emits: export VAR='VAL'
4096 // bash: declare -x VAR="VAL"
4097 // (both also escape as needed (quotes, $, etc))
4102 return EXIT_SUCCESS;
4105 value = strchr(name, '=');
4107 /* They are exporting something without a =VALUE */
4108 struct variable *var;
4110 var = get_local_var(name);
4112 var->flg_export = 1;
4113 putenv(var->varstr);
4115 /* bash does not return an error when trying to export
4116 * an undefined variable. Do likewise. */
4117 return EXIT_SUCCESS;
4120 set_local_var(xstrdup(name), 1);
4121 return EXIT_SUCCESS;
4125 /* built-in 'fg' and 'bg' handler */
4126 static int builtin_fg_bg(char **argv)
4131 if (!interactive_fd)
4132 return EXIT_FAILURE;
4133 /* If they gave us no args, assume they want the last backgrounded task */
4135 for (pi = job_list; pi; pi = pi->next) {
4136 if (pi->jobid == last_jobid) {
4140 bb_error_msg("%s: no current job", argv[0]);
4141 return EXIT_FAILURE;
4143 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
4144 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
4145 return EXIT_FAILURE;
4147 for (pi = job_list; pi; pi = pi->next) {
4148 if (pi->jobid == jobnum) {
4152 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
4153 return EXIT_FAILURE;
4155 // TODO: bash prints a string representation
4156 // of job being foregrounded (like "sleep 1 | cat")
4157 if (*argv[0] == 'f') {
4158 /* Put the job into the foreground. */
4159 tcsetpgrp(interactive_fd, pi->pgrp);
4162 /* Restart the processes in the job */
4163 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_progs, pi->pgrp);
4164 for (i = 0; i < pi->num_progs; i++) {
4165 debug_printf_jobs("reviving pid %d\n", pi->progs[i].pid);
4166 pi->progs[i].is_stopped = 0;
4168 pi->stopped_progs = 0;
4170 i = kill(- pi->pgrp, SIGCONT);
4172 if (errno == ESRCH) {
4173 delete_finished_bg_job(pi);
4174 return EXIT_SUCCESS;
4176 bb_perror_msg("kill (SIGCONT)");
4180 if (*argv[0] == 'f') {
4182 return checkjobs_and_fg_shell(pi);
4184 return EXIT_SUCCESS;
4188 #if ENABLE_HUSH_HELP
4189 static int builtin_help(char **argv ATTRIBUTE_UNUSED)
4191 const struct built_in_command *x;
4193 printf("\nBuilt-in commands:\n");
4194 printf("-------------------\n");
4195 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
4196 printf("%s\t%s\n", x->cmd, x->descr);
4199 return EXIT_SUCCESS;
4204 static int builtin_jobs(char **argv ATTRIBUTE_UNUSED)
4207 const char *status_string;
4209 for (job = job_list; job; job = job->next) {
4210 if (job->alive_progs == job->stopped_progs)
4211 status_string = "Stopped";
4213 status_string = "Running";
4215 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
4217 return EXIT_SUCCESS;
4221 static int builtin_pwd(char **argv ATTRIBUTE_UNUSED)
4224 return EXIT_SUCCESS;
4227 static int builtin_read(char **argv)
4230 const char *name = argv[1] ? argv[1] : "REPLY";
4232 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
4233 return set_local_var(string, 0);
4236 /* built-in 'set [VAR=value]' handler */
4237 static int builtin_set(char **argv)
4239 char *temp = argv[1];
4243 for (e = top_var; e; e = e->next)
4246 set_local_var(xstrdup(temp), 0);
4248 return EXIT_SUCCESS;
4251 static int builtin_shift(char **argv)
4257 if (n >= 0 && n < global_argc) {
4258 global_argv[n] = global_argv[0];
4261 return EXIT_SUCCESS;
4263 return EXIT_FAILURE;
4266 static int builtin_source(char **argv)
4271 if (argv[1] == NULL)
4272 return EXIT_FAILURE;
4274 /* XXX search through $PATH is missing */
4275 input = fopen(argv[1], "r");
4277 bb_error_msg("cannot open '%s'", argv[1]);
4278 return EXIT_FAILURE;
4280 close_on_exec_on(fileno(input));
4282 /* Now run the file */
4283 /* XXX argv and argc are broken; need to save old global_argv
4284 * (pointer only is OK!) on this stack frame,
4285 * set global_argv=argv+1, recurse, and restore. */
4286 status = parse_and_run_file(input);
4291 static int builtin_umask(char **argv)
4294 const char *arg = argv[1];
4297 new_umask = strtoul(arg, &end, 8);
4298 if (*end != '\0' || end == arg) {
4299 return EXIT_FAILURE;
4302 new_umask = umask(0);
4303 printf("%.3o\n", (unsigned) new_umask);
4306 return EXIT_SUCCESS;
4309 static int builtin_unset(char **argv)
4311 /* bash always returns true */
4312 unset_local_var(argv[1]);
4313 return EXIT_SUCCESS;