1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
11 * The parser routines proper are all original material, first
12 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
13 * execution engine, the builtins, and much of the underlying
14 * support has been adapted from busybox-0.49pre's lash, which is
15 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
16 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
17 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
18 * Troan, which they placed in the public domain. I don't know
19 * how much of the Johnson/Troan code has survived the repeated
23 * o_addchr() derived from similar w_addchar function in glibc-2.2.
24 * setup_redirect(), redirect_opt_num(), and big chunks of main()
25 * and many builtins derived from contributions by Erik Andersen.
26 * Miscellaneous bugfixes from Matt Kraai.
28 * There are two big (and related) architecture differences between
29 * this parser and the lash parser. One is that this version is
30 * actually designed from the ground up to understand nearly all
31 * of the Bourne grammar. The second, consequential change is that
32 * the parser and input reader have been turned inside out. Now,
33 * the parser is in control, and asks for input as needed. The old
34 * way had the input reader in control, and it asked for parsing to
35 * take place as needed. The new way makes it much easier to properly
36 * handle the recursion implicit in the various substitutions, especially
37 * across continuation lines.
39 * POSIX syntax not implemented:
41 * <(list) and >(list) Process Substitution
42 * Here Documents ( << word )
45 * Parameter Expansion for substring processing ${var#word} ${var%word}
47 * Bash stuff maybe optional enable:
48 * &> and >& redirection of stdout+stderr
50 * reserved words: [[ ]] function select
51 * substrings ${var:1:5}
54 * job handling woefully incomplete and buggy (improved --vda)
56 * port selected bugfixes from post-0.49 busybox lash - done?
57 * change { and } from special chars to reserved words
58 * builtins: return, trap, ulimit
59 * test magic exec with redirection only
60 * follow IFS rules more precisely, including update semantics
61 * figure out what to do with backslash-newline
62 * propagate syntax errors, die on resource errors?
63 * continuation lines, both explicit and implicit - done?
64 * maybe change charmap[] to use 2-bit entries
66 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
69 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
70 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
71 //#include "applet_tables.h" doesn't work
73 /* #include <dmalloc.h> */
80 #define HUSH_VER_STR "0.92"
82 #if defined SINGLE_APPLET_MAIN
83 /* STANDALONE does not make sense, and won't compile */
84 #undef CONFIG_FEATURE_SH_STANDALONE
85 #undef ENABLE_FEATURE_SH_STANDALONE
86 #undef USE_FEATURE_SH_STANDALONE
87 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
88 #define ENABLE_FEATURE_SH_STANDALONE 0
89 #define USE_FEATURE_SH_STANDALONE(...)
90 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
93 #if !BB_MMU && ENABLE_HUSH_TICK
94 //#undef ENABLE_HUSH_TICK
95 //#define ENABLE_HUSH_TICK 0
96 #warning On NOMMU, hush command substitution is dangerous.
97 #warning Dont use it for commands which produce lots of output.
98 #warning For more info see shell/hush.c, generate_stream_from_list().
101 #if !ENABLE_HUSH_INTERACTIVE
102 #undef ENABLE_FEATURE_EDITING
103 #define ENABLE_FEATURE_EDITING 0
104 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
105 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
108 /* Do we support ANY keywords? */
109 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
110 #define HAS_KEYWORDS 1
111 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
112 #define IF_HAS_NO_KEYWORDS(...)
114 #define HAS_KEYWORDS 0
115 #define IF_HAS_KEYWORDS(...)
116 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
119 /* Keep unconditionally on for now */
122 #define ENABLE_HUSH_FUNCTIONS 0
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
141 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
144 #ifndef debug_printf_parse
145 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
148 #ifndef debug_printf_exec
149 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
152 #ifndef debug_printf_env
153 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
156 #ifndef debug_printf_jobs
157 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
163 #ifndef debug_printf_expand
164 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
165 #define DEBUG_EXPAND 1
167 #define DEBUG_EXPAND 0
170 #ifndef debug_printf_glob
171 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
177 #ifndef debug_printf_list
178 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
181 #ifndef debug_printf_subst
182 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
185 #ifndef debug_printf_clean
186 /* broken, of course, but OK for testing */
187 static const char *indenter(int i)
189 static const char blanks[] ALIGN1 =
191 return &blanks[sizeof(blanks) - i - 1];
193 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
194 #define DEBUG_CLEAN 1
198 static void debug_print_strings(const char *prefix, char **vv)
200 fprintf(stderr, "%s:\n", prefix);
202 fprintf(stderr, " '%s'\n", *vv++);
205 #define debug_print_strings(prefix, vv) ((void)0)
209 * Leak hunting. Use hush_leaktool.sh for post-processing.
211 #ifdef FOR_HUSH_LEAKTOOL
212 /* suppress "warning: no previous prototype..." */
213 void *xxmalloc(int lineno, size_t size);
214 void *xxrealloc(int lineno, void *ptr, size_t size);
215 char *xxstrdup(int lineno, const char *str);
216 void xxfree(void *ptr);
217 void *xxmalloc(int lineno, size_t size)
219 void *ptr = xmalloc((size + 0xff) & ~0xff);
220 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
223 void *xxrealloc(int lineno, void *ptr, size_t size)
225 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
226 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
229 char *xxstrdup(int lineno, const char *str)
231 char *ptr = xstrdup(str);
232 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
235 void xxfree(void *ptr)
237 fdprintf(2, "free %p\n", ptr);
240 #define xmalloc(s) xxmalloc(__LINE__, s)
241 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
242 #define xstrdup(s) xxstrdup(__LINE__, s)
243 #define free(p) xxfree(p)
247 #define ERR_PTR ((void*)(long)1)
249 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="HUSH_VER_STR;
251 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
253 #define SPECIAL_VAR_SYMBOL 3
255 typedef enum redir_type {
257 REDIRECT_OVERWRITE = 2,
263 /* The descrip member of this structure is only used to make
264 * debugging output pretty */
265 static const struct {
267 signed char default_fd;
271 { O_RDONLY, 0, "<" },
272 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
273 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
274 { O_RDONLY, -1, "<<" },
278 typedef enum pipe_style {
285 typedef enum reserved_style {
294 #if ENABLE_HUSH_LOOPS
301 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
306 /* two pseudo-keywords support contrived "case" syntax: */
307 RES_MATCH , /* "word)" */
308 RES_CASEI , /* "this command is inside CASE" */
315 struct redir_struct {
316 struct redir_struct *next;
317 char *rd_filename; /* filename */
318 int fd; /* file descriptor being redirected */
319 int dup; /* -1, or file descriptor being duplicated */
320 smallint /*enum redir_type*/ rd_type;
324 pid_t pid; /* 0 if exited */
325 int assignment_cnt; /* how many argv[i] are assignments? */
326 smallint is_stopped; /* is the command currently running? */
327 smallint grp_type; /* GRP_xxx */
328 struct pipe *group; /* if non-NULL, this "prog" is {} group,
329 * subshell, or a compound statement */
330 char **argv; /* command name and arguments */
331 struct redir_struct *redirects; /* I/O redirections */
333 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
334 * and on execution these are substituted with their values.
335 * Substitution can make _several_ words out of one argv[n]!
336 * Example: argv[0]=='.^C*^C.' here: echo .$*.
337 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
340 #define GRP_SUBSHELL 1
341 #if ENABLE_HUSH_FUNCTIONS
342 #define GRP_FUNCTION 2
347 int num_cmds; /* total number of commands in job */
348 int alive_cmds; /* number of commands running (not exited) */
349 int stopped_cmds; /* number of commands alive, but stopped */
351 int jobid; /* job number */
352 pid_t pgrp; /* process group ID for the job */
353 char *cmdtext; /* name of job */
355 struct command *cmds; /* array of commands in pipe */
356 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
357 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
358 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
361 /* This holds pointers to the various results of parsing */
362 struct parse_context {
363 /* linked list of pipes */
364 struct pipe *list_head;
365 /* last pipe (being constructed right now) */
367 /* last command in pipe (being constructed right now) */
368 struct command *command;
369 /* last redirect in command->redirects list */
370 struct redir_struct *pending_redirect;
373 smallint ctx_inverted; /* "! cmd | cmd" */
375 smallint ctx_dsemicolon; /* ";;" seen */
377 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
379 /* group we are enclosed in:
380 * example 1: "{ { false; ..."
381 * example 2: "if true; then { false; ..."
382 * example 3: "if true; then if false; ..."
383 * when we find closing "}" / "fi" / whatever, we move list_head
384 * into stack->command->group and delete ourself.
386 struct parse_context *stack;
390 /* On program start, environ points to initial environment.
391 * putenv adds new pointers into it, unsetenv removes them.
392 * Neither of these (de)allocates the strings.
393 * setenv allocates new strings in malloc space and does putenv,
394 * and thus setenv is unusable (leaky) for shell's purposes */
395 #define setenv(...) setenv_is_leaky_dont_use()
397 struct variable *next;
398 char *varstr; /* points to "name=" portion */
399 int max_len; /* if > 0, name is part of initial env; else name is malloced */
400 smallint flg_export; /* putenv should be done on this var */
401 smallint flg_read_only;
404 typedef struct o_string {
406 int length; /* position where data is appended */
408 /* Protect newly added chars against globbing
409 * (by prepending \ to *, ?, [, \) */
413 smallint has_empty_slot;
414 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
417 MAYBE_ASSIGNMENT = 0,
418 DEFINITELY_ASSIGNMENT = 1,
420 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
422 /* Used for initialization: o_string foo = NULL_O_STRING; */
423 #define NULL_O_STRING { NULL }
425 /* I can almost use ordinary FILE*. Is open_memstream() universally
426 * available? Where is it documented? */
427 typedef struct in_str {
429 /* eof_flag=1: last char in ->p is really an EOF */
430 char eof_flag; /* meaningless if ->p == NULL */
432 #if ENABLE_HUSH_INTERACTIVE
434 smallint promptmode; /* 0: PS1, 1: PS2 */
437 int (*get) (struct in_str *);
438 int (*peek) (struct in_str *);
440 #define i_getch(input) ((input)->get(input))
441 #define i_peek(input) ((input)->peek(input))
445 CHAR_ORDINARY_IF_QUOTED = 1, /* example: *, # */
446 CHAR_IFS = 2, /* treated as ordinary if quoted */
447 CHAR_SPECIAL = 3, /* \, $, ", maybe ` */
456 /* "Globals" within this file */
457 /* Sorted roughly by size (smaller offsets == smaller code) */
459 #if ENABLE_HUSH_INTERACTIVE
460 /* 'interactive_fd' is a fd# open to ctty, if we have one
461 * _AND_ if we decided to act interactively */
466 #if ENABLE_FEATURE_EDITING
467 line_input_t *line_input_state;
473 pid_t saved_tty_pgrp;
475 struct pipe *job_list;
476 struct pipe *toplevel_list;
477 //// smallint ctrl_z_flag;
479 smallint flag_SIGINT;
480 #if ENABLE_HUSH_LOOPS
481 smallint flag_break_continue;
484 /* These four support $?, $#, and $1 */
485 smalluint last_return_code;
486 /* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
487 smalluint global_args_malloced;
488 /* how many non-NULL argv's we have. NB: $# + 1 */
491 #if ENABLE_HUSH_LOOPS
492 unsigned depth_break_continue;
493 unsigned depth_of_loop;
497 struct variable *top_var; /* = &G.shell_ver (set in main()) */
498 struct variable shell_ver;
499 #if ENABLE_FEATURE_SH_STANDALONE
500 struct nofork_save_area nofork_save;
503 sigjmp_buf toplevel_jb;
505 unsigned char charmap[256];
506 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
507 /* Signal and trap handling */
508 // unsigned count_SIGCHLD;
509 // unsigned handled_SIGCHLD;
510 /* which signals have non-DFL handler (even with no traps set)? */
511 unsigned non_DFL_mask;
512 char **traps; /* char *traps[NSIG] */
513 sigset_t blocked_set;
514 sigset_t inherited_set;
516 #define G (*ptr_to_globals)
517 /* Not #defining name to G.name - this quickly gets unwieldy
518 * (too many defines). Also, I actually prefer to see when a variable
519 * is global, thus "G." prefix is a useful hint */
520 #define INIT_G() do { \
521 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
525 /* Function prototypes for builtins */
526 static int builtin_cd(char **argv);
527 static int builtin_echo(char **argv);
528 static int builtin_eval(char **argv);
529 static int builtin_exec(char **argv);
530 static int builtin_exit(char **argv);
531 static int builtin_export(char **argv);
533 static int builtin_fg_bg(char **argv);
534 static int builtin_jobs(char **argv);
537 static int builtin_help(char **argv);
539 static int builtin_pwd(char **argv);
540 static int builtin_read(char **argv);
541 static int builtin_test(char **argv);
542 static int builtin_trap(char **argv);
543 static int builtin_true(char **argv);
544 static int builtin_set(char **argv);
545 static int builtin_shift(char **argv);
546 static int builtin_source(char **argv);
547 static int builtin_umask(char **argv);
548 static int builtin_unset(char **argv);
549 static int builtin_wait(char **argv);
550 #if ENABLE_HUSH_LOOPS
551 static int builtin_break(char **argv);
552 static int builtin_continue(char **argv);
554 //static int builtin_not_written(char **argv);
556 /* Table of built-in functions. They can be forked or not, depending on
557 * context: within pipes, they fork. As simple commands, they do not.
558 * When used in non-forking context, they can change global variables
559 * in the parent shell process. If forked, of course they cannot.
560 * For example, 'unset foo | whatever' will parse and run, but foo will
561 * still be set at the end. */
562 struct built_in_command {
564 int (*function)(char **argv);
567 #define BLTIN(cmd, func, help) { cmd, func, help }
569 #define BLTIN(cmd, func, help) { cmd, func }
573 /* For now, echo and test are unconditionally enabled.
574 * Maybe make it configurable? */
575 static const struct built_in_command bltins[] = {
576 BLTIN("." , builtin_source, "Run commands in a file"),
577 BLTIN(":" , builtin_true, "No-op"),
578 BLTIN("[" , builtin_test, "Test condition"),
580 BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
582 #if ENABLE_HUSH_LOOPS
583 BLTIN("break" , builtin_break, "Exit from a loop"),
585 BLTIN("cd" , builtin_cd, "Change directory"),
586 #if ENABLE_HUSH_LOOPS
587 BLTIN("continue", builtin_continue, "Start new loop iteration"),
589 BLTIN("echo" , builtin_echo, "Write to stdout"),
590 BLTIN("eval" , builtin_eval, "Construct and run shell command"),
591 BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
592 BLTIN("exit" , builtin_exit, "Exit"),
593 BLTIN("export", builtin_export, "Set environment variable"),
595 BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
596 BLTIN("jobs" , builtin_jobs, "List active jobs"),
598 BLTIN("pwd" , builtin_pwd, "Print current directory"),
599 BLTIN("read" , builtin_read, "Input environment variable"),
600 // BLTIN("return", builtin_not_written, "Return from a function"),
601 BLTIN("set" , builtin_set, "Set/unset shell local variables"),
602 BLTIN("shift" , builtin_shift, "Shift positional parameters"),
603 BLTIN("test" , builtin_test, "Test condition"),
604 BLTIN("trap" , builtin_trap, "Trap signals"),
605 // BLTIN("ulimit", builtin_not_written, "Control resource limits"),
606 BLTIN("umask" , builtin_umask, "Set file creation mask"),
607 BLTIN("unset" , builtin_unset, "Unset environment variable"),
608 BLTIN("wait" , builtin_wait, "Wait for process"),
610 BLTIN("help" , builtin_help, "List shell built-in commands"),
616 static void maybe_die(const char *notice, const char *msg)
618 /* Was using fancy stuff:
619 * (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
620 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
621 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
622 #if ENABLE_HUSH_INTERACTIVE
623 fp = (G.interactive_fd ? bb_error_msg : bb_error_msg_and_die);
625 fp(msg ? "%s: %s" : notice, notice, msg);
628 #define syntax(msg) maybe_die("syntax error", msg);
630 /* Debug -- trick gcc to expand __LINE__ and convert to string */
631 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
632 #define _syntax(msg, line) __syntax(msg, line)
633 #define syntax(msg) _syntax(msg, __LINE__)
636 static int glob_needed(const char *s)
641 if (*s == '*' || *s == '[' || *s == '?')
648 static int is_assignment(const char *s)
650 if (!s || !(isalpha(*s) || *s == '_'))
653 while (isalnum(*s) || *s == '_')
658 /* Replace each \x with x in place, return ptr past NUL. */
659 static char *unbackslash(char *src)
665 if ((*dst++ = *src++) == '\0')
671 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
692 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
693 v[count1 + count2] = NULL;
696 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
700 static char **add_string_to_strings(char **strings, char *add)
705 return add_strings_to_strings(strings, v, /*dup:*/ 0);
708 static void putenv_all(char **strings)
713 debug_printf_env("putenv '%s'\n", *strings);
718 static char **putenv_all_and_save_old(char **strings)
728 eq = strchr(*strings, '=');
731 v = getenv(*strings);
734 /* v points to VAL in VAR=VAL, go back to VAR */
735 v -= (eq - *strings) + 1;
736 old = add_string_to_strings(old, v);
745 static void free_strings_and_unsetenv(char **strings, int unset)
755 debug_printf_env("unsetenv '%s'\n", *v);
763 static void free_strings(char **strings)
765 free_strings_and_unsetenv(strings, 0);
769 /* Basic theory of signal handling in shell
770 * ========================================
771 * This does not describe what hush does, rather, it is current understanding
772 * what it _should_ do. If it doesn't, it's a bug.
773 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
775 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
776 * is finished or backgrounded. It is the same in interactive and
777 * non-interactive shells, and is the same regardless of whether
778 * a user trap handler is installed or a shell special one is in effect.
779 * ^C or ^Z from keyboard seem to execute "at once" because it usually
780 * backgrounds (i.e. stops) or kills all members of currently running
783 * Wait builtin in interruptible by signals for which user trap is set
784 * or by SIGINT in interactive shell.
786 * Trap handlers will execute even within trap handlers. (right?)
788 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
790 * If job control is off, backgrounded commands ("cmd &")
791 * have SIGINT, SIGQUIT set to SIG_IGN.
793 * Commands run in command substitution ("`cmd`")
794 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
796 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
797 * by the shell from its parent.
799 * Siganls which differ from SIG_DFL action
800 * (note: child (i.e., [v]forked) shell is not an interactive shell):
803 * SIGTERM (interactive): ignore
804 * SIGHUP (interactive):
805 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
806 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
807 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
808 * that all pipe members are stopped) (right?)
809 * SIGINT (interactive): wait for last pipe, ignore the rest
810 * of the command line, show prompt. NB: ^C does not send SIGINT
811 * to interactive shell while shell is waiting for a pipe,
812 * since shell is bg'ed (is not in foreground process group).
813 * (check/expand this)
814 * Example 1: this waits 5 sec, but does not execute ls:
815 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
816 * Example 2: this does not wait and does not execute ls:
817 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
818 * Example 3: this does not wait 5 sec, but executes ls:
819 * "sleep 5; ls -l" + press ^C
821 * (What happens to signals which are IGN on shell start?)
822 * (What happens with signal mask on shell start?)
824 * Implementation in hush
825 * ======================
826 * We use in-kernel pending signal mask to determine which signals were sent.
827 * We block all signals which we don't want to take action immediately,
828 * i.e. we block all signals which need to have special handling as described
829 * above, and all signals which have traps set.
830 * After each pipe execution, we extract any pending signals via sigtimedwait()
833 * unsigned non_DFL_mask: a mask of such "special" signals
834 * sigset_t blocked_set: current blocked signal set
837 * clear bit in blocked_set unless it is also in non_DFL
838 * "trap 'cmd' SIGxxx":
839 * set bit in blocked_set (even if 'cmd' is '')
840 * after [v]fork, if we plan to be a shell:
841 * nothing for {} child shell (say, "true | { true; true; } | true")
842 * unset all traps if () shell. [TODO]
843 * after [v]fork, if we plan to exec:
844 * POSIX says pending signal mask is cleared in child - no need to clear it.
845 * Restore blocked signal set to one inherited by shell just prior to exec.
847 * Note: as a result, we do not use signal handlers much. The only uses
848 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
849 * and to restore tty pgrp on signal-induced exit.
851 * TODO: check/fix wait builtin to be interruptible.
854 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
856 // G.count_SIGCHLD++;
859 /* called once at shell init */
860 static void init_signal_mask(void)
863 unsigned mask = (1 << SIGQUIT);
864 #if ENABLE_HUSH_INTERACTIVE
865 if (G.interactive_fd) {
871 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
877 G.non_DFL_mask = mask;
879 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
883 sigaddset(&G.blocked_set, sig);
887 sigdelset(&G.blocked_set, SIGCHLD);
888 sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
891 static int check_and_run_traps(int sig)
893 static const struct timespec zero_timespec = { 0, 0 };
894 smalluint save_rcode;
900 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
905 if (G.traps && G.traps[sig]) {
906 if (G.traps[sig][0]) {
907 /* We have user-defined handler */
908 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
909 save_rcode = G.last_return_code;
912 G.last_return_code = save_rcode;
913 } /* else: "" trap, ignoring signal */
916 /* not a trap: special action */
919 // G.count_SIGCHLD++;
928 default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
937 /* Restores tty foreground process group, and exits.
938 * May be called as signal handler for fatal signal
939 * (will faithfully resend signal to itself, producing correct exit state)
940 * or called directly with -EXITCODE.
941 * We also call it if xfunc is exiting. */
942 static void sigexit(int sig) NORETURN;
943 static void sigexit(int sig)
945 /* Disable all signals: job control, SIGPIPE, etc. */
946 sigprocmask_allsigs(SIG_BLOCK);
948 #if ENABLE_HUSH_INTERACTIVE
949 /* Careful: we can end up here after [v]fork. Do not restore
950 * tty pgrp then, only top-level shell process does that */
951 if (G.interactive_fd && getpid() == G.root_pid)
952 tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
955 /* Not a signal, just exit */
959 kill_myself_with_sig(sig); /* does not return */
963 static void maybe_set_sighandler(int sig)
965 void (*handler)(int);
966 /* non_DFL_mask'ed signals are, well, masked,
967 * no need to set handler for them.
969 if (!((G.non_DFL_mask >> sig) & 1)) {
970 handler = signal(sig, sigexit);
971 if (handler == SIG_IGN) /* oops... restore back to IGN! */
972 signal(sig, handler);
975 /* Used only to set handler to restore pgrp on exit */
976 static void set_fatal_signals_to_sigexit(void)
979 maybe_set_sighandler(SIGILL );
980 maybe_set_sighandler(SIGFPE );
981 maybe_set_sighandler(SIGBUS );
982 maybe_set_sighandler(SIGSEGV);
983 maybe_set_sighandler(SIGTRAP);
984 } /* else: hush is perfect. what SEGV? */
986 maybe_set_sighandler(SIGABRT);
988 /* bash 3.2 seems to handle these just like 'fatal' ones */
989 maybe_set_sighandler(SIGPIPE);
990 maybe_set_sighandler(SIGALRM);
991 maybe_set_sighandler(SIGHUP );
993 /* if we aren't interactive... but in this case
994 * we never want to restore pgrp on exit, and this fn is not called */
995 /*maybe_set_sighandler(SIGTERM);*/
996 /*maybe_set_sighandler(SIGINT );*/
998 /* Used only to suppress ^Z in `cmd` */
999 static void set_jobctrl_signals_to_IGN(void)
1010 #define set_fatal_signals_to_sigexit(handler) ((void)0)
1011 #define set_jobctrl_signals_to_IGN(handler) ((void)0)
1015 /* Restores tty foreground process group, and exits. */
1016 static void hush_exit(int exitcode) NORETURN;
1017 static void hush_exit(int exitcode)
1019 if (G.traps && G.traps[0] && G.traps[0][0]) {
1020 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1026 fflush(NULL); /* flush all streams */
1027 sigexit(- (exitcode & 0xff));
1034 static const char *set_cwd(void)
1036 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1037 * we must not try to free(bb_msg_unknown) */
1038 if (G.cwd == bb_msg_unknown)
1040 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1042 G.cwd = bb_msg_unknown;
1047 /* Get/check local shell variables */
1048 static struct variable *get_local_var(const char *name)
1050 struct variable *cur;
1056 for (cur = G.top_var; cur; cur = cur->next) {
1057 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1063 /* Basically useful version until someone wants to get fancier,
1064 * see the bash man page under "Parameter Expansion" */
1065 static const char *lookup_param(const char *src)
1067 struct variable *var = get_local_var(src);
1069 return strchr(var->varstr, '=') + 1;
1073 /* str holds "NAME=VAL" and is expected to be malloced.
1074 * We take ownership of it.
1075 * flg_export is used by:
1078 * -1: if NAME is set, leave export status alone
1079 * if NAME is not set, do not export
1081 static int set_local_var(char *str, int flg_export)
1083 struct variable *cur;
1087 value = strchr(str, '=');
1088 if (!value) { /* not expected to ever happen? */
1093 name_len = value - str + 1; /* including '=' */
1094 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1096 if (strncmp(cur->varstr, str, name_len) != 0) {
1098 /* Bail out. Note that now cur points
1099 * to last var in linked list */
1105 /* We found an existing var with this name */
1107 if (cur->flg_read_only) {
1108 bb_error_msg("%s: readonly variable", str);
1112 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1113 unsetenv(str); /* just in case */
1115 if (strcmp(cur->varstr, str) == 0) {
1120 if (cur->max_len >= strlen(str)) {
1121 /* This one is from startup env, reuse space */
1122 strcpy(cur->varstr, str);
1125 /* max_len == 0 signifies "malloced" var, which we can
1126 * (and has to) free */
1130 goto set_str_and_exp;
1133 /* Not found - create next variable struct */
1134 cur->next = xzalloc(sizeof(*cur));
1140 if (flg_export == 1)
1141 cur->flg_export = 1;
1142 if (cur->flg_export) {
1143 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1144 return putenv(cur->varstr);
1149 static int unset_local_var(const char *name)
1151 struct variable *cur;
1152 struct variable *prev = prev; /* for gcc */
1156 return EXIT_SUCCESS;
1157 name_len = strlen(name);
1160 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1161 if (cur->flg_read_only) {
1162 bb_error_msg("%s: readonly variable", name);
1163 return EXIT_FAILURE;
1165 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1166 * is ro, and we cannot reach this code on the 1st pass */
1167 prev->next = cur->next;
1168 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1169 bb_unsetenv(cur->varstr);
1173 return EXIT_SUCCESS;
1178 return EXIT_SUCCESS;
1181 #if ENABLE_SH_MATH_SUPPORT
1182 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1183 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1184 static char *endofname(const char *name)
1192 if (!is_in_name(*p))
1198 static void arith_set_local_var(const char *name, const char *val, int flags)
1200 /* arith code doesnt malloc space, so do it for it */
1201 char *var = xasprintf("%s=%s", name, val);
1202 set_local_var(var, flags);
1210 static int static_get(struct in_str *i)
1219 static int static_peek(struct in_str *i)
1224 #if ENABLE_HUSH_INTERACTIVE
1226 static void cmdedit_set_initial_prompt(void)
1228 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1229 G.PS1 = getenv("PS1");
1236 static const char* setup_prompt_string(int promptmode)
1238 const char *prompt_str;
1239 debug_printf("setup_prompt_string %d ", promptmode);
1240 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1241 /* Set up the prompt */
1242 if (promptmode == 0) { /* PS1 */
1244 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1249 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1250 debug_printf("result '%s'\n", prompt_str);
1254 static void get_user_input(struct in_str *i)
1257 const char *prompt_str;
1259 prompt_str = setup_prompt_string(i->promptmode);
1260 #if ENABLE_FEATURE_EDITING
1261 /* Enable command line editing only while a command line
1262 * is actually being read */
1265 /* buglet: SIGINT will not make new prompt to appear _at once_,
1266 * only after <Enter>. (^C will work) */
1267 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1268 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1269 check_and_run_traps(0);
1270 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1271 i->eof_flag = (r < 0);
1272 if (i->eof_flag) { /* EOF/error detected */
1273 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1274 G.user_input_buf[1] = '\0';
1279 fputs(prompt_str, stdout);
1281 G.user_input_buf[0] = r = fgetc(i->file);
1282 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1283 //do we need check_and_run_traps(0)? (maybe only if stdin)
1284 } while (G.flag_SIGINT);
1285 i->eof_flag = (r == EOF);
1287 i->p = G.user_input_buf;
1290 #endif /* INTERACTIVE */
1292 /* This is the magic location that prints prompts
1293 * and gets data back from the user */
1294 static int file_get(struct in_str *i)
1298 /* If there is data waiting, eat it up */
1299 if (i->p && *i->p) {
1300 #if ENABLE_HUSH_INTERACTIVE
1304 if (i->eof_flag && !*i->p)
1307 /* need to double check i->file because we might be doing something
1308 * more complicated by now, like sourcing or substituting. */
1309 #if ENABLE_HUSH_INTERACTIVE
1310 if (G.interactive_fd && i->promptme && i->file == stdin) {
1313 } while (!*i->p); /* need non-empty line */
1314 i->promptmode = 1; /* PS2 */
1319 ch = fgetc(i->file);
1321 debug_printf("file_get: got a '%c' %d\n", ch, ch);
1322 #if ENABLE_HUSH_INTERACTIVE
1329 /* All the callers guarantee this routine will never be
1330 * used right after a newline, so prompting is not needed.
1332 static int file_peek(struct in_str *i)
1335 if (i->p && *i->p) {
1336 if (i->eof_flag && !i->p[1])
1340 ch = fgetc(i->file);
1341 i->eof_flag = (ch == EOF);
1342 i->peek_buf[0] = ch;
1343 i->peek_buf[1] = '\0';
1345 debug_printf("file_peek: got a '%c' %d\n", *i->p, *i->p);
1349 static void setup_file_in_str(struct in_str *i, FILE *f)
1351 i->peek = file_peek;
1353 #if ENABLE_HUSH_INTERACTIVE
1355 i->promptmode = 0; /* PS1 */
1361 static void setup_string_in_str(struct in_str *i, const char *s)
1363 i->peek = static_peek;
1364 i->get = static_get;
1365 #if ENABLE_HUSH_INTERACTIVE
1367 i->promptmode = 0; /* PS1 */
1377 #define B_CHUNK (32 * sizeof(char*))
1379 static void o_reset(o_string *o)
1387 static void o_free(o_string *o)
1390 memset(o, 0, sizeof(*o));
1393 static void o_grow_by(o_string *o, int len)
1395 if (o->length + len > o->maxlen) {
1396 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1397 o->data = xrealloc(o->data, 1 + o->maxlen);
1401 static void o_addchr(o_string *o, int ch)
1403 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1405 o->data[o->length] = ch;
1407 o->data[o->length] = '\0';
1410 static void o_addstr(o_string *o, const char *str, int len)
1413 memcpy(&o->data[o->length], str, len);
1415 o->data[o->length] = '\0';
1418 static void o_addstrauto(o_string *o, const char *str)
1420 o_addstr(o, str, strlen(str) + 1);
1423 static void o_addstr_duplicate_backslash(o_string *o, const char *str, int len)
1428 && (*str != '*' && *str != '?' && *str != '[')
1436 /* My analysis of quoting semantics tells me that state information
1437 * is associated with a destination, not a source.
1439 static void o_addqchr(o_string *o, int ch)
1442 char *found = strchr("*?[\\", ch);
1447 o->data[o->length] = '\\';
1450 o->data[o->length] = ch;
1452 o->data[o->length] = '\0';
1455 static void o_addQchr(o_string *o, int ch)
1458 if (o->o_escape && strchr("*?[\\", ch)) {
1460 o->data[o->length] = '\\';
1464 o->data[o->length] = ch;
1466 o->data[o->length] = '\0';
1469 static void o_addQstr(o_string *o, const char *str, int len)
1472 o_addstr(o, str, len);
1478 int ordinary_cnt = strcspn(str, "*?[\\");
1479 if (ordinary_cnt > len) /* paranoia */
1481 o_addstr(o, str, ordinary_cnt);
1482 if (ordinary_cnt == len)
1484 str += ordinary_cnt;
1485 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1489 if (ch) { /* it is necessarily one of "*?[\\" */
1491 o->data[o->length] = '\\';
1495 o->data[o->length] = ch;
1497 o->data[o->length] = '\0';
1501 /* A special kind of o_string for $VAR and `cmd` expansion.
1502 * It contains char* list[] at the beginning, which is grown in 16 element
1503 * increments. Actual string data starts at the next multiple of 16 * (char*).
1504 * list[i] contains an INDEX (int!) into this string data.
1505 * It means that if list[] needs to grow, data needs to be moved higher up
1506 * but list[i]'s need not be modified.
1507 * NB: remembering how many list[i]'s you have there is crucial.
1508 * o_finalize_list() operation post-processes this structure - calculates
1509 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1511 #if DEBUG_EXPAND || DEBUG_GLOB
1512 static void debug_print_list(const char *prefix, o_string *o, int n)
1514 char **list = (char**)o->data;
1515 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1517 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1518 prefix, list, n, string_start, o->length, o->maxlen);
1520 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1521 o->data + (int)list[i] + string_start,
1522 o->data + (int)list[i] + string_start);
1526 const char *p = o->data + (int)list[n - 1] + string_start;
1527 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1531 #define debug_print_list(prefix, o, n) ((void)0)
1534 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1535 * in list[n] so that it points past last stored byte so far.
1536 * It returns n+1. */
1537 static int o_save_ptr_helper(o_string *o, int n)
1539 char **list = (char**)o->data;
1543 if (!o->has_empty_slot) {
1544 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1545 string_len = o->length - string_start;
1546 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1547 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1548 /* list[n] points to string_start, make space for 16 more pointers */
1549 o->maxlen += 0x10 * sizeof(list[0]);
1550 o->data = xrealloc(o->data, o->maxlen + 1);
1551 list = (char**)o->data;
1552 memmove(list + n + 0x10, list + n, string_len);
1553 o->length += 0x10 * sizeof(list[0]);
1555 debug_printf_list("list[%d]=%d string_start=%d\n", n, string_len, string_start);
1557 /* We have empty slot at list[n], reuse without growth */
1558 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1559 string_len = o->length - string_start;
1560 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n", n, string_len, string_start);
1561 o->has_empty_slot = 0;
1563 list[n] = (char*)(ptrdiff_t)string_len;
1567 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1568 static int o_get_last_ptr(o_string *o, int n)
1570 char **list = (char**)o->data;
1571 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1573 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1576 /* o_glob performs globbing on last list[], saving each result
1577 * as a new list[]. */
1578 static int o_glob(o_string *o, int n)
1584 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1586 return o_save_ptr_helper(o, n);
1587 pattern = o->data + o_get_last_ptr(o, n);
1588 debug_printf_glob("glob pattern '%s'\n", pattern);
1589 if (!glob_needed(pattern)) {
1591 o->length = unbackslash(pattern) - o->data;
1592 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1593 return o_save_ptr_helper(o, n);
1596 memset(&globdata, 0, sizeof(globdata));
1597 gr = glob(pattern, 0, NULL, &globdata);
1598 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1599 if (gr == GLOB_NOSPACE)
1600 bb_error_msg_and_die("out of memory during glob");
1601 if (gr == GLOB_NOMATCH) {
1602 globfree(&globdata);
1605 if (gr != 0) { /* GLOB_ABORTED ? */
1606 //TODO: testcase for bad glob pattern behavior
1607 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1609 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1610 char **argv = globdata.gl_pathv;
1611 o->length = pattern - o->data; /* "forget" pattern */
1613 o_addstrauto(o, *argv);
1614 n = o_save_ptr_helper(o, n);
1620 globfree(&globdata);
1622 debug_print_list("o_glob returning", o, n);
1626 /* If o->o_glob == 1, glob the string so far remembered.
1627 * Otherwise, just finish current list[] and start new */
1628 static int o_save_ptr(o_string *o, int n)
1630 if (o->o_glob) { /* if globbing is requested */
1631 /* If o->has_empty_slot, list[n] was already globbed
1632 * (if it was requested back then when it was filled)
1633 * so don't do that again! */
1634 if (!o->has_empty_slot)
1635 return o_glob(o, n); /* o_save_ptr_helper is inside */
1637 return o_save_ptr_helper(o, n);
1640 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1641 static char **o_finalize_list(o_string *o, int n)
1646 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1648 debug_print_list("finalized", o, n);
1649 debug_printf_expand("finalized n:%d\n", n);
1650 list = (char**)o->data;
1651 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1655 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1661 /* Expansion can recurse */
1662 #if ENABLE_HUSH_TICK
1663 static int process_command_subs(o_string *dest, struct in_str *input);
1665 static char *expand_string_to_string(const char *str);
1666 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end);
1668 /* expand_strvec_to_strvec() takes a list of strings, expands
1669 * all variable references within and returns a pointer to
1670 * a list of expanded strings, possibly with larger number
1671 * of strings. (Think VAR="a b"; echo $VAR).
1672 * This new list is allocated as a single malloc block.
1673 * NULL-terminated list of char* pointers is at the beginning of it,
1674 * followed by strings themself.
1675 * Caller can deallocate entire list by single free(list). */
1677 /* Store given string, finalizing the word and starting new one whenever
1678 * we encounter IFS char(s). This is used for expanding variable values.
1679 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1680 static int expand_on_ifs(o_string *output, int n, const char *str)
1683 int word_len = strcspn(str, G.ifs);
1685 if (output->o_escape || !output->o_glob)
1686 o_addQstr(output, str, word_len);
1687 else /* protect backslashes against globbing up :) */
1688 o_addstr_duplicate_backslash(output, str, word_len);
1691 if (!*str) /* EOL - do not finalize word */
1693 o_addchr(output, '\0');
1694 debug_print_list("expand_on_ifs", output, n);
1695 n = o_save_ptr(output, n);
1696 str += strspn(str, G.ifs); /* skip ifs chars */
1698 debug_print_list("expand_on_ifs[1]", output, n);
1702 /* Expand all variable references in given string, adding words to list[]
1703 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1704 * to be filled). This routine is extremely tricky: has to deal with
1705 * variables/parameters with whitespace, $* and $@, and constructs like
1706 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1707 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1709 /* or_mask is either 0 (normal case) or 0x80
1710 * (expansion of right-hand side of assignment == 1-element expand.
1711 * It will also do no globbing, and thus we must not backslash-quote!) */
1713 char first_ch, ored_ch;
1720 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1721 debug_print_list("expand_vars_to_list", output, n);
1722 n = o_save_ptr(output, n);
1723 debug_print_list("expand_vars_to_list[0]", output, n);
1725 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1726 #if ENABLE_HUSH_TICK
1727 o_string subst_result = NULL_O_STRING;
1729 #if ENABLE_SH_MATH_SUPPORT
1730 char arith_buf[sizeof(arith_t)*3 + 2];
1732 o_addstr(output, arg, p - arg);
1733 debug_print_list("expand_vars_to_list[1]", output, n);
1735 p = strchr(p, SPECIAL_VAR_SYMBOL);
1737 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1738 /* "$@" is special. Even if quoted, it can still
1739 * expand to nothing (not even an empty string) */
1740 if ((first_ch & 0x7f) != '@')
1741 ored_ch |= first_ch;
1744 switch (first_ch & 0x7f) {
1745 /* Highest bit in first_ch indicates that var is double-quoted */
1747 val = utoa(G.root_pid);
1749 case '!': /* bg pid */
1750 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1752 case '?': /* exitcode */
1753 val = utoa(G.last_return_code);
1755 case '#': /* argc */
1756 if (arg[1] != SPECIAL_VAR_SYMBOL)
1757 /* actually, it's a ${#var} */
1759 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1764 if (!G.global_argv[i])
1766 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1767 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1768 smallint sv = output->o_escape;
1769 /* unquoted var's contents should be globbed, so don't escape */
1770 output->o_escape = 0;
1771 while (G.global_argv[i]) {
1772 n = expand_on_ifs(output, n, G.global_argv[i]);
1773 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1774 if (G.global_argv[i++][0] && G.global_argv[i]) {
1775 /* this argv[] is not empty and not last:
1776 * put terminating NUL, start new word */
1777 o_addchr(output, '\0');
1778 debug_print_list("expand_vars_to_list[2]", output, n);
1779 n = o_save_ptr(output, n);
1780 debug_print_list("expand_vars_to_list[3]", output, n);
1783 output->o_escape = sv;
1785 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1786 * and in this case should treat it like '$*' - see 'else...' below */
1787 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1789 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1790 if (++i >= G.global_argc)
1792 o_addchr(output, '\0');
1793 debug_print_list("expand_vars_to_list[4]", output, n);
1794 n = o_save_ptr(output, n);
1796 } else { /* quoted $*: add as one word */
1798 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1799 if (!G.global_argv[++i])
1802 o_addchr(output, G.ifs[0]);
1806 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1807 /* "Empty variable", used to make "" etc to not disappear */
1811 #if ENABLE_HUSH_TICK
1812 case '`': { /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1813 struct in_str input;
1816 //TODO: can we just stuff it into "output" directly?
1817 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1818 setup_string_in_str(&input, arg);
1819 process_command_subs(&subst_result, &input);
1820 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1821 val = subst_result.data;
1825 #if ENABLE_SH_MATH_SUPPORT
1826 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1827 arith_eval_hooks_t hooks;
1832 arg++; /* skip '+' */
1833 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1834 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1836 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1839 unsigned char c = *exp_str++;
1846 if (strchr(" \t+-*/%_", c) != NULL)
1848 c |= 0x20; /* tolower */
1849 if (c >= 'a' && c <= 'z')
1853 /* We need to expand. Example: "echo $(($a + 1)) $((1 + $((2)) ))" */
1855 struct in_str input;
1856 o_string dest = NULL_O_STRING;
1858 setup_string_in_str(&input, arg);
1859 parse_stream_dquoted(&dest, &input, EOF);
1860 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1861 exp_str = expand_string_to_string(dest.data);
1862 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1866 hooks.lookupvar = lookup_param;
1867 hooks.setvar = arith_set_local_var;
1868 hooks.endofname = endofname;
1869 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1874 case -3: maybe_die("arith", "exponent less than 0"); break;
1875 case -2: maybe_die("arith", "divide by zero"); break;
1876 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1877 default: maybe_die("arith", "syntax error"); break;
1880 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1881 sprintf(arith_buf, arith_t_fmt, res);
1886 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1888 bool exp_len = false, exp_null = false;
1889 char *var = arg, exp_save, exp_op, *exp_word;
1892 arg[0] = first_ch & 0x7f;
1894 /* prepare for expansions */
1895 if (var[0] == '#') {
1896 /* handle length expansion ${#var} */
1900 /* maybe handle parameter expansion */
1901 exp_off = strcspn(var, ":-=+?");
1905 exp_save = var[exp_off];
1906 exp_null = exp_save == ':';
1907 exp_word = var + exp_off;
1908 if (exp_null) ++exp_word;
1909 exp_op = *exp_word++;
1910 var[exp_off] = '\0';
1914 /* lookup the variable in question */
1915 if (isdigit(var[0])) {
1916 /* handle_dollar() should have vetted var for us */
1918 if (i < G.global_argc)
1919 val = G.global_argv[i];
1920 /* else val remains NULL: $N with too big N */
1922 val = lookup_param(var);
1924 /* handle any expansions */
1926 debug_printf_expand("expand: length of '%s' = ", val);
1927 val = utoa(val ? strlen(val) : 0);
1928 debug_printf_expand("%s\n", val);
1929 } else if (exp_off) {
1930 /* we need to do an expansion */
1931 int exp_test = (!val || (exp_null && !val[0]));
1933 exp_test = !exp_test;
1934 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1935 exp_null ? "true" : "false", exp_test);
1938 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1942 if (exp_op == '=') {
1943 if (isdigit(var[0]) || var[0] == '#') {
1944 maybe_die(var, "special vars cannot assign in this way");
1947 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1948 sprintf(new_var, "%s=%s", var, val);
1949 set_local_var(new_var, -1);
1953 var[exp_off] = exp_save;
1958 #if ENABLE_HUSH_TICK
1961 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1962 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1964 /* unquoted var's contents should be globbed, so don't escape */
1965 smallint sv = output->o_escape;
1966 output->o_escape = 0;
1967 n = expand_on_ifs(output, n, val);
1969 output->o_escape = sv;
1971 } else { /* quoted $VAR, val will be appended below */
1972 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1975 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1977 o_addQstr(output, val, strlen(val));
1979 /* Do the check to avoid writing to a const string */
1980 if (*p != SPECIAL_VAR_SYMBOL)
1981 *p = SPECIAL_VAR_SYMBOL;
1983 #if ENABLE_HUSH_TICK
1984 o_free(&subst_result);
1987 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1990 debug_print_list("expand_vars_to_list[a]", output, n);
1991 /* this part is literal, and it was already pre-quoted
1992 * if needed (much earlier), do not use o_addQstr here! */
1993 o_addstrauto(output, arg);
1994 debug_print_list("expand_vars_to_list[b]", output, n);
1995 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1996 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1999 /* allow to reuse list[n] later without re-growth */
2000 output->has_empty_slot = 1;
2002 o_addchr(output, '\0');
2007 static char **expand_variables(char **argv, int or_mask)
2012 o_string output = NULL_O_STRING;
2014 if (or_mask & 0x100) {
2015 output.o_escape = 1; /* protect against globbing for "$var" */
2016 /* (unquoted $var will temporarily switch it off) */
2023 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2026 debug_print_list("expand_variables", &output, n);
2028 /* output.data (malloced in one block) gets returned in "list" */
2029 list = o_finalize_list(&output, n);
2030 debug_print_strings("expand_variables[1]", list);
2034 static char **expand_strvec_to_strvec(char **argv)
2036 return expand_variables(argv, 0x100);
2039 /* Used for expansion of right hand of assignments */
2040 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2042 static char *expand_string_to_string(const char *str)
2044 char *argv[2], **list;
2046 argv[0] = (char*)str;
2048 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2050 if (!list[0] || list[1])
2051 bb_error_msg_and_die("BUG in varexp2");
2052 /* actually, just move string 2*sizeof(char*) bytes back */
2053 overlapping_strcpy((char*)list, list[0]);
2054 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2058 /* Used for "eval" builtin */
2059 static char* expand_strvec_to_string(char **argv)
2063 list = expand_variables(argv, 0x80);
2064 /* Convert all NULs to spaces */
2069 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2070 bb_error_msg_and_die("BUG in varexp3");
2071 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2075 overlapping_strcpy((char*)list, list[0]);
2076 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2080 static char **expand_assignments(char **argv, int count)
2084 /* Expand assignments into one string each */
2085 for (i = 0; i < count; i++) {
2086 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2092 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2093 * and stderr if they are redirected. */
2094 static int setup_redirects(struct command *prog, int squirrel[])
2097 struct redir_struct *redir;
2099 for (redir = prog->redirects; redir; redir = redir->next) {
2100 if (redir->dup == -1 && redir->rd_filename == NULL) {
2101 /* something went wrong in the parse. Pretend it didn't happen */
2104 if (redir->dup == -1) {
2106 mode = redir_table[redir->rd_type].mode;
2107 //TODO: check redir for names like '\\'
2108 p = expand_string_to_string(redir->rd_filename);
2109 openfd = open_or_warn(p, mode);
2112 /* this could get lost if stderr has been redirected, but
2113 bash and ash both lose it as well (though zsh doesn't!) */
2117 openfd = redir->dup;
2120 if (openfd != redir->fd) {
2121 if (squirrel && redir->fd < 3) {
2122 squirrel[redir->fd] = dup(redir->fd);
2125 //close(openfd); // close(-3) ??!
2127 dup2(openfd, redir->fd);
2128 if (redir->dup == -1)
2136 static void restore_redirects(int squirrel[])
2139 for (i = 0; i < 3; i++) {
2142 /* We simply die on error */
2149 #if !defined(DEBUG_CLEAN)
2150 #define free_pipe_list(head, indent) free_pipe_list(head)
2151 #define free_pipe(pi, indent) free_pipe(pi)
2153 static void free_pipe_list(struct pipe *head, int indent);
2155 /* return code is the exit status of the pipe */
2156 static void free_pipe(struct pipe *pi, int indent)
2159 struct command *command;
2160 struct redir_struct *r, *rnext;
2163 if (pi->stopped_cmds > 0)
2165 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2166 for (i = 0; i < pi->num_cmds; i++) {
2167 command = &pi->cmds[i];
2168 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2169 if (command->argv) {
2170 for (a = 0, p = command->argv; *p; a++, p++) {
2171 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2173 free_strings(command->argv);
2174 command->argv = NULL;
2176 /* not "else if": on syntax error, we may have both! */
2177 if (command->group) {
2178 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2179 free_pipe_list(command->group, indent+3);
2180 debug_printf_clean("%s end group\n", indenter(indent));
2181 command->group = NULL;
2183 for (r = command->redirects; r; r = rnext) {
2184 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2186 /* guard against the case >$FOO, where foo is unset or blank */
2187 if (r->rd_filename) {
2188 debug_printf_clean(" %s\n", r->rd_filename);
2189 free(r->rd_filename);
2190 r->rd_filename = NULL;
2193 debug_printf_clean("&%d\n", r->dup);
2198 command->redirects = NULL;
2200 free(pi->cmds); /* children are an array, they get freed all at once */
2208 static void free_pipe_list(struct pipe *head, int indent)
2210 struct pipe *pi, *next;
2212 for (pi = head; pi; pi = next) {
2214 debug_printf_clean("%s pipe reserved mode %d\n", indenter(indent), pi->res_word);
2216 free_pipe(pi, indent);
2217 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2219 /*pi->next = NULL;*/
2226 typedef struct nommu_save_t {
2232 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2233 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2234 #define pseudo_exec(nommu_save, command, argv_expanded) \
2235 pseudo_exec(command, argv_expanded)
2238 /* Called after [v]fork() in run_pipe(), or from builtin_exec().
2240 * XXX no exit() here. If you don't exec, use _exit instead.
2241 * The at_exit handlers apparently confuse the calling process,
2242 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2243 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded) NORETURN;
2244 static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignment_cnt, char **argv_expanded)
2248 const struct built_in_command *x;
2250 /* If a variable is assigned in a forest, and nobody listens,
2251 * was it ever really set?
2253 if (!argv[assignment_cnt])
2254 _exit(EXIT_SUCCESS);
2256 new_env = expand_assignments(argv, assignment_cnt);
2258 putenv_all(new_env);
2259 free(new_env); /* optional */
2261 nommu_save->new_env = new_env;
2262 nommu_save->old_env = putenv_all_and_save_old(new_env);
2264 if (argv_expanded) {
2265 argv = argv_expanded;
2267 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2269 nommu_save->argv = argv;
2274 * Check if the command matches any of the builtins.
2275 * Depending on context, this might be redundant. But it's
2276 * easier to waste a few CPU cycles than it is to figure out
2277 * if this is one of those cases.
2279 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2280 if (strcmp(argv[0], x->cmd) == 0) {
2281 debug_printf_exec("running builtin '%s'\n", argv[0]);
2282 rcode = x->function(argv);
2288 /* Check if the command matches any busybox applets */
2289 #if ENABLE_FEATURE_SH_STANDALONE
2290 if (strchr(argv[0], '/') == NULL) {
2291 int a = find_applet_by_name(argv[0]);
2293 if (APPLET_IS_NOEXEC(a)) {
2294 debug_printf_exec("running applet '%s'\n", argv[0]);
2295 // is it ok that run_applet_no_and_exit() does exit(), not _exit()?
2296 run_applet_no_and_exit(a, argv);
2298 /* re-exec ourselves with the new arguments */
2299 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2300 execvp(bb_busybox_exec_path, argv);
2301 /* If they called chroot or otherwise made the binary no longer
2302 * executable, fall through */
2307 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2309 debug_printf_exec("execing '%s'\n", argv[0]);
2310 execvp(argv[0], argv);
2311 bb_perror_msg("can't exec '%s'", argv[0]);
2312 _exit(EXIT_FAILURE);
2315 static int run_list(struct pipe *pi);
2317 /* Called after [v]fork() in run_pipe()
2319 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded) NORETURN;
2320 static void pseudo_exec(nommu_save_t *nommu_save, struct command *command, char **argv_expanded)
2323 pseudo_exec_argv(nommu_save, command->argv, command->assignment_cnt, argv_expanded);
2325 if (command->group) {
2327 bb_error_msg_and_die("nested lists are not supported on NOMMU");
2330 debug_printf_exec("pseudo_exec: run_list\n");
2331 rcode = run_list(command->group);
2332 /* OK to leak memory by not calling free_pipe_list,
2333 * since this process is about to exit */
2338 /* Can happen. See what bash does with ">foo" by itself. */
2339 debug_printf("trying to pseudo_exec null command\n");
2340 _exit(EXIT_SUCCESS);
2344 static const char *get_cmdtext(struct pipe *pi)
2350 /* This is subtle. ->cmdtext is created only on first backgrounding.
2351 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2352 * On subsequent bg argv is trashed, but we won't use it */
2355 argv = pi->cmds[0].argv;
2356 if (!argv || !argv[0]) {
2357 pi->cmdtext = xzalloc(1);
2362 do len += strlen(*argv) + 1; while (*++argv);
2363 pi->cmdtext = p = xmalloc(len);
2364 argv = pi->cmds[0].argv;
2366 len = strlen(*argv);
2367 memcpy(p, *argv, len);
2375 static void insert_bg_job(struct pipe *pi)
2377 struct pipe *thejob;
2380 /* Linear search for the ID of the job to use */
2382 for (thejob = G.job_list; thejob; thejob = thejob->next)
2383 if (thejob->jobid >= pi->jobid)
2384 pi->jobid = thejob->jobid + 1;
2386 /* Add thejob to the list of running jobs */
2388 thejob = G.job_list = xmalloc(sizeof(*thejob));
2390 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2392 thejob->next = xmalloc(sizeof(*thejob));
2393 thejob = thejob->next;
2396 /* Physically copy the struct job */
2397 memcpy(thejob, pi, sizeof(struct pipe));
2398 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2399 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2400 for (i = 0; i < pi->num_cmds; i++) {
2401 // TODO: do we really need to have so many fields which are just dead weight
2402 // at execution stage?
2403 thejob->cmds[i].pid = pi->cmds[i].pid;
2404 /* all other fields are not used and stay zero */
2406 thejob->next = NULL;
2407 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2409 /* We don't wait for background thejobs to return -- append it
2410 to the list of backgrounded thejobs and leave it alone */
2411 if (G.interactive_fd)
2412 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2413 G.last_bg_pid = thejob->cmds[0].pid;
2414 G.last_jobid = thejob->jobid;
2417 static void remove_bg_job(struct pipe *pi)
2419 struct pipe *prev_pipe;
2421 if (pi == G.job_list) {
2422 G.job_list = pi->next;
2424 prev_pipe = G.job_list;
2425 while (prev_pipe->next != pi)
2426 prev_pipe = prev_pipe->next;
2427 prev_pipe->next = pi->next;
2430 G.last_jobid = G.job_list->jobid;
2435 /* Remove a backgrounded job */
2436 static void delete_finished_bg_job(struct pipe *pi)
2439 pi->stopped_cmds = 0;
2445 /* Check to see if any processes have exited -- if they
2446 * have, figure out why and see if a job has completed */
2447 static int checkjobs(struct pipe* fg_pipe)
2457 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2460 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2461 // /* avoid doing syscall, nothing there anyway */
2464 attributes = WUNTRACED;
2465 if (fg_pipe == NULL)
2466 attributes |= WNOHANG;
2468 /* Do we do this right?
2469 * bash-3.00# sleep 20 | false
2471 * [3]+ Stopped sleep 20 | false
2472 * bash-3.00# echo $?
2473 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2476 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2477 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2478 // + killall -STOP cat
2485 // i = G.count_SIGCHLD;
2486 childpid = waitpid(-1, &status, attributes);
2487 if (childpid <= 0) {
2488 if (childpid && errno != ECHILD)
2489 bb_perror_msg("waitpid");
2490 // else /* Until next SIGCHLD, waitpid's are useless */
2491 // G.handled_SIGCHLD = i;
2494 dead = WIFEXITED(status) || WIFSIGNALED(status);
2497 if (WIFSTOPPED(status))
2498 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2499 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2500 if (WIFSIGNALED(status))
2501 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2502 childpid, WTERMSIG(status), WEXITSTATUS(status));
2503 if (WIFEXITED(status))
2504 debug_printf_jobs("pid %d exited, exitcode %d\n",
2505 childpid, WEXITSTATUS(status));
2507 /* Were we asked to wait for fg pipe? */
2509 for (i = 0; i < fg_pipe->num_cmds; i++) {
2510 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2511 if (fg_pipe->cmds[i].pid != childpid)
2513 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2515 fg_pipe->cmds[i].pid = 0;
2516 fg_pipe->alive_cmds--;
2517 if (i == fg_pipe->num_cmds - 1) {
2518 /* last process gives overall exitstatus */
2519 rcode = WEXITSTATUS(status);
2520 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2523 fg_pipe->cmds[i].is_stopped = 1;
2524 fg_pipe->stopped_cmds++;
2526 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2527 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2528 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2529 /* All processes in fg pipe have exited/stopped */
2531 if (fg_pipe->alive_cmds)
2532 insert_bg_job(fg_pipe);
2536 /* There are still running processes in the fg pipe */
2537 goto wait_more; /* do waitpid again */
2539 /* it wasnt fg_pipe, look for process in bg pipes */
2543 /* We asked to wait for bg or orphaned children */
2544 /* No need to remember exitcode in this case */
2545 for (pi = G.job_list; pi; pi = pi->next) {
2546 for (i = 0; i < pi->num_cmds; i++) {
2547 if (pi->cmds[i].pid == childpid)
2548 goto found_pi_and_prognum;
2551 /* Happens when shell is used as init process (init=/bin/sh) */
2552 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2553 continue; /* do waitpid again */
2555 found_pi_and_prognum:
2558 pi->cmds[i].pid = 0;
2560 if (!pi->alive_cmds) {
2561 if (G.interactive_fd)
2562 printf(JOB_STATUS_FORMAT, pi->jobid,
2563 "Done", pi->cmdtext);
2564 delete_finished_bg_job(pi);
2568 pi->cmds[i].is_stopped = 1;
2572 } /* while (waitpid succeeds)... */
2578 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2581 int rcode = checkjobs(fg_pipe);
2582 /* Job finished, move the shell to the foreground */
2583 p = getpgid(0); /* pgid of our process */
2584 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2585 tcsetpgrp(G.interactive_fd, p);
2590 /* run_pipe() starts all the jobs, but doesn't wait for anything
2591 * to finish. See checkjobs().
2593 * return code is normally -1, when the caller has to wait for children
2594 * to finish to determine the exit status of the pipe. If the pipe
2595 * is a simple builtin command, however, the action is done by the
2596 * time run_pipe returns, and the exit code is provided as the
2599 * The input of the pipe is always stdin, the output is always
2600 * stdout. The outpipe[] mechanism in BusyBox-0.48 lash is bogus,
2601 * because it tries to avoid running the command substitution in
2602 * subshell, when that is in fact necessary. The subshell process
2603 * now has its stdout directed to the input of the appropriate pipe,
2604 * so this routine is noticeably simpler.
2606 * Returns -1 only if started some children. IOW: we have to
2607 * mask out retvals of builtins etc with 0xff!
2609 static int run_pipe(struct pipe *pi)
2613 int pipefds[2]; /* pipefds[0] is for reading */
2614 struct command *command;
2615 char **argv_expanded;
2617 const struct built_in_command *x;
2619 /* it is not always needed, but we aim to smaller code */
2620 int squirrel[] = { -1, -1, -1 };
2622 const int single_and_fg = (pi->num_cmds == 1 && pi->followup != PIPE_BG);
2624 debug_printf_exec("run_pipe start: single_and_fg=%d\n", single_and_fg);
2630 pi->stopped_cmds = 0;
2632 /* Check if this is a simple builtin (not part of a pipe).
2633 * Builtins within pipes have to fork anyway, and are handled in
2634 * pseudo_exec. "echo foo | read bar" doesn't work on bash, either.
2636 command = &(pi->cmds[0]);
2638 #if ENABLE_HUSH_FUNCTIONS
2639 if (single_and_fg && command->group && command->grp_type == GRP_FUNCTION) {
2640 /* We "execute" function definition */
2641 bb_error_msg("here we ought to remember function definition, and go on");
2642 return EXIT_SUCCESS;
2646 if (single_and_fg && command->group && command->grp_type == GRP_NORMAL) {
2647 debug_printf("non-subshell grouping\n");
2648 setup_redirects(command, squirrel);
2649 debug_printf_exec(": run_list\n");
2650 rcode = run_list(command->group) & 0xff;
2651 restore_redirects(squirrel);
2652 debug_printf_exec("run_pipe return %d\n", rcode);
2653 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2657 argv = command->argv;
2658 argv_expanded = NULL;
2660 if (single_and_fg && argv != NULL) {
2661 char **new_env = NULL;
2662 char **old_env = NULL;
2664 i = command->assignment_cnt;
2665 if (i != 0 && argv[i] == NULL) {
2666 /* assignments, but no command: set local environment */
2667 for (i = 0; argv[i] != NULL; i++) {
2668 debug_printf("local environment set: %s\n", argv[i]);
2669 p = expand_string_to_string(argv[i]);
2670 set_local_var(p, 0);
2672 return EXIT_SUCCESS; /* don't worry about errors in set_local_var() yet */
2675 /* Expand the rest into (possibly) many strings each */
2676 argv_expanded = expand_strvec_to_strvec(argv + i);
2678 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2679 if (strcmp(argv_expanded[0], x->cmd) != 0)
2681 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2682 debug_printf("exec with redirects only\n");
2683 setup_redirects(command, NULL);
2684 rcode = EXIT_SUCCESS;
2685 goto clean_up_and_ret1;
2687 debug_printf("builtin inline %s\n", argv_expanded[0]);
2688 /* XXX setup_redirects acts on file descriptors, not FILEs.
2689 * This is perfect for work that comes after exec().
2690 * Is it really safe for inline use? Experimentally,
2691 * things seem to work with glibc. */
2692 setup_redirects(command, squirrel);
2693 new_env = expand_assignments(argv, command->assignment_cnt);
2694 old_env = putenv_all_and_save_old(new_env);
2695 debug_printf_exec(": builtin '%s' '%s'...\n", x->cmd, argv_expanded[1]);
2696 rcode = x->function(argv_expanded) & 0xff;
2697 #if ENABLE_FEATURE_SH_STANDALONE
2700 restore_redirects(squirrel);
2701 free_strings_and_unsetenv(new_env, 1);
2702 putenv_all(old_env);
2703 free(old_env); /* not free_strings()! */
2705 free(argv_expanded);
2706 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2707 debug_printf_exec("run_pipe return %d\n", rcode);
2710 #if ENABLE_FEATURE_SH_STANDALONE
2711 i = find_applet_by_name(argv_expanded[0]);
2712 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2713 setup_redirects(command, squirrel);
2714 save_nofork_data(&G.nofork_save);
2715 new_env = expand_assignments(argv, command->assignment_cnt);
2716 old_env = putenv_all_and_save_old(new_env);
2717 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n", argv_expanded[0], argv_expanded[1]);
2718 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2719 goto clean_up_and_ret;
2724 /* NB: argv_expanded may already be created, and that
2725 * might include `cmd` runs! Do not rerun it! We *must*
2726 * use argv_expanded if it's non-NULL */
2728 /* Going to fork a child per each pipe member */
2732 for (i = 0; i < pi->num_cmds; i++) {
2734 volatile nommu_save_t nommu_save;
2735 nommu_save.new_env = NULL;
2736 nommu_save.old_env = NULL;
2737 nommu_save.argv = NULL;
2739 command = &(pi->cmds[i]);
2740 if (command->argv) {
2741 debug_printf_exec(": pipe member '%s' '%s'...\n", command->argv[0], command->argv[1]);
2743 debug_printf_exec(": pipe member with no argv\n");
2745 /* pipes are inserted between pairs of commands */
2748 if ((i + 1) < pi->num_cmds)
2751 command->pid = BB_MMU ? fork() : vfork();
2752 if (!command->pid) { /* child */
2754 die_sleep = 0; /* let nofork's xfuncs die */
2756 /* Every child adds itself to new process group
2757 * with pgid == pid_of_first_child_in_pipe */
2758 if (G.run_list_level == 1 && G.interactive_fd) {
2761 if (pgrp < 0) /* true for 1st process only */
2763 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2764 /* We do it in *every* child, not just first,
2766 tcsetpgrp(G.interactive_fd, pgrp);
2770 xmove_fd(nextin, 0);
2771 xmove_fd(pipefds[1], 1); /* write end */
2773 close(pipefds[0]); /* read end */
2774 /* Like bash, explicit redirects override pipes,
2775 * and the pipe fd is available for dup'ing. */
2776 setup_redirects(command, NULL);
2778 /* Restore default handlers just prior to exec */
2779 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
2781 /* Stores to nommu_save list of env vars putenv'ed
2782 * (NOMMU, on MMU we don't need that) */
2783 /* cast away volatility... */
2784 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
2785 /* pseudo_exec() does not return */
2789 /* Clean up after vforked child */
2790 free(nommu_save.argv);
2791 free_strings_and_unsetenv(nommu_save.new_env, 1);
2792 putenv_all(nommu_save.old_env);
2794 free(argv_expanded);
2795 argv_expanded = NULL;
2796 if (command->pid < 0) { /* [v]fork failed */
2797 /* Clearly indicate, was it fork or vfork */
2798 bb_perror_msg(BB_MMU ? "fork" : "vfork");
2802 /* Second and next children need to know pid of first one */
2804 pi->pgrp = command->pid;
2810 if ((i + 1) < pi->num_cmds)
2811 close(pipefds[1]); /* write end */
2812 /* Pass read (output) pipe end to next iteration */
2813 nextin = pipefds[0];
2816 if (!pi->alive_cmds) {
2817 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
2821 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
2825 #ifndef debug_print_tree
2826 static void debug_print_tree(struct pipe *pi, int lvl)
2828 static const char *const PIPE[] = {
2834 static const char *RES[] = {
2835 [RES_NONE ] = "NONE" ,
2838 [RES_THEN ] = "THEN" ,
2839 [RES_ELIF ] = "ELIF" ,
2840 [RES_ELSE ] = "ELSE" ,
2843 #if ENABLE_HUSH_LOOPS
2844 [RES_FOR ] = "FOR" ,
2845 [RES_WHILE] = "WHILE",
2846 [RES_UNTIL] = "UNTIL",
2848 [RES_DONE ] = "DONE" ,
2850 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2853 #if ENABLE_HUSH_CASE
2854 [RES_CASE ] = "CASE" ,
2855 [RES_MATCH] = "MATCH",
2856 [RES_CASEI] = "CASEI",
2857 [RES_ESAC ] = "ESAC" ,
2859 [RES_XXXX ] = "XXXX" ,
2860 [RES_SNTX ] = "SNTX" ,
2862 static const char *const GRPTYPE[] = {
2865 #if ENABLE_HUSH_FUNCTIONS
2874 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2875 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2877 while (prn < pi->num_cmds) {
2878 struct command *command = &pi->cmds[prn];
2879 char **argv = command->argv;
2881 fprintf(stderr, "%*s prog %d assignment_cnt:%d", lvl*2, "", prn, command->assignment_cnt);
2882 if (command->group) {
2883 fprintf(stderr, " group %s: (argv=%p)\n",
2884 GRPTYPE[command->grp_type],
2886 debug_print_tree(command->group, lvl+1);
2890 if (argv) while (*argv) {
2891 fprintf(stderr, " '%s'", *argv);
2894 fprintf(stderr, "\n");
2903 /* NB: called by pseudo_exec, and therefore must not modify any
2904 * global data until exec/_exit (we can be a child after vfork!) */
2905 static int run_list(struct pipe *pi)
2907 #if ENABLE_HUSH_CASE
2908 char *case_word = NULL;
2910 #if ENABLE_HUSH_LOOPS
2911 struct pipe *loop_top = NULL;
2912 char *for_varname = NULL;
2913 char **for_lcur = NULL;
2914 char **for_list = NULL;
2916 smallint flag_skip = 1;
2917 smalluint rcode = 0; /* probably just for compiler */
2918 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
2919 smalluint cond_code = 0;
2921 enum { cond_code = 0, };
2923 /*enum reserved_style*/ smallint rword = RES_NONE;
2924 /*enum reserved_style*/ smallint skip_more_for_this_rword = RES_XXXX;
2926 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
2928 #if ENABLE_HUSH_LOOPS
2929 /* Check syntax for "for" */
2930 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
2931 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
2933 /* current word is FOR or IN (BOLD in comments below) */
2934 if (cpipe->next == NULL) {
2935 syntax("malformed for");
2936 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2939 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
2940 if (cpipe->next->res_word == RES_DO)
2942 /* next word is not "do". It must be "in" then ("FOR v in ...") */
2943 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
2944 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
2946 syntax("malformed for");
2947 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
2953 /* Past this point, all code paths should jump to ret: label
2954 * in order to return, no direct "return" statements please.
2955 * This helps to ensure that no memory is leaked. */
2957 ////TODO: ctrl-Z handling needs re-thinking and re-testing
2960 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
2961 * We are saving state before entering outermost list ("while...done")
2962 * so that ctrl-Z will correctly background _entire_ outermost list,
2963 * not just a part of it (like "sleep 1 | exit 2") */
2964 if (++G.run_list_level == 1 && G.interactive_fd) {
2965 if (sigsetjmp(G.toplevel_jb, 1)) {
2966 /* ctrl-Z forked and we are parent; or ctrl-C.
2967 * Sighandler has longjmped us here */
2968 signal(SIGINT, SIG_IGN);
2969 signal(SIGTSTP, SIG_IGN);
2970 /* Restore level (we can be coming from deep inside
2972 G.run_list_level = 1;
2973 #if ENABLE_FEATURE_SH_STANDALONE
2974 if (G.nofork_save.saved) { /* if save area is valid */
2975 debug_printf_jobs("exiting nofork early\n");
2976 restore_nofork_data(&G.nofork_save);
2979 //// if (G.ctrl_z_flag) {
2980 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
2981 //// * Remember this child as background job */
2982 //// insert_bg_job(pi);
2984 /* ctrl-C. We just stop doing whatever we were doing */
2987 USE_HUSH_LOOPS(loop_top = NULL;)
2988 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
2992 //// /* ctrl-Z handler will store pid etc in pi */
2993 //// G.toplevel_list = pi;
2994 //// G.ctrl_z_flag = 0;
2995 ////#if ENABLE_FEATURE_SH_STANDALONE
2996 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
2998 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
2999 //// signal(SIGINT, handler_ctrl_c);
3003 /* Go through list of pipes, (maybe) executing them. */
3004 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3008 IF_HAS_KEYWORDS(rword = pi->res_word;)
3009 IF_HAS_NO_KEYWORDS(rword = RES_NONE;)
3010 debug_printf_exec(": rword=%d cond_code=%d skip_more=%d\n",
3011 rword, cond_code, skip_more_for_this_rword);
3012 #if ENABLE_HUSH_LOOPS
3013 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3014 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3016 /* start of a loop: remember where loop starts */
3021 if (rword == skip_more_for_this_rword && flag_skip) {
3022 if (pi->followup == PIPE_SEQ)
3024 /* it is "<false> && CMD" or "<true> || CMD"
3025 * and we should not execute CMD */
3029 skip_more_for_this_rword = RES_XXXX;
3032 if (rword == RES_THEN) {
3033 /* "if <false> THEN cmd": skip cmd */
3037 if (rword == RES_ELSE || rword == RES_ELIF) {
3038 /* "if <true> then ... ELSE/ELIF cmd":
3039 * skip cmd and all following ones */
3044 #if ENABLE_HUSH_LOOPS
3045 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3047 /* first loop through for */
3049 static const char encoded_dollar_at[] ALIGN1 = {
3050 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3051 }; /* encoded representation of "$@" */
3052 static const char *const encoded_dollar_at_argv[] = {
3053 encoded_dollar_at, NULL
3054 }; /* argv list with one element: "$@" */
3057 vals = (char**)encoded_dollar_at_argv;
3058 if (pi->next->res_word == RES_IN) {
3059 /* if no variable values after "in" we skip "for" */
3060 if (!pi->next->cmds[0].argv)
3062 vals = pi->next->cmds[0].argv;
3063 } /* else: "for var; do..." -> assume "$@" list */
3064 /* create list of variable values */
3065 debug_print_strings("for_list made from", vals);
3066 for_list = expand_strvec_to_strvec(vals);
3067 for_lcur = for_list;
3068 debug_print_strings("for_list", for_list);
3069 for_varname = pi->cmds[0].argv[0];
3070 pi->cmds[0].argv[0] = NULL;
3072 free(pi->cmds[0].argv[0]);
3074 /* "for" loop is over, clean up */
3078 pi->cmds[0].argv[0] = for_varname;
3081 /* insert next value from for_lcur */
3082 //TODO: does it need escaping?
3083 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3084 pi->cmds[0].assignment_cnt = 1;
3086 if (rword == RES_IN) /* "for v IN list;..." - "in" has no cmds anyway */
3088 if (rword == RES_DONE) {
3089 continue; /* "done" has no cmds too */
3092 #if ENABLE_HUSH_CASE
3093 if (rword == RES_CASE) {
3094 case_word = expand_strvec_to_string(pi->cmds->argv);
3097 if (rword == RES_MATCH) {
3100 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3102 /* all prev words didn't match, does this one match? */
3103 argv = pi->cmds->argv;
3105 char *pattern = expand_string_to_string(*argv);
3106 /* TODO: which FNM_xxx flags to use? */
3107 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3109 if (cond_code == 0) { /* match! we will execute this branch */
3110 free(case_word); /* make future "word)" stop */
3118 if (rword == RES_CASEI) { /* inside of a case branch */
3120 continue; /* not matched yet, skip this pipe */
3123 /* Just pressing <enter> in shell should check for jobs.
3124 * OTOH, in non-interactive shell this is useless
3125 * and only leads to extra job checks */
3126 if (pi->num_cmds == 0) {
3127 if (G.interactive_fd)
3128 goto check_jobs_and_continue;
3132 /* After analyzing all keywords and conditions, we decided
3133 * to execute this pipe. NB: have to do checkjobs(NULL)
3134 * after run_pipe() to collect any background children,
3135 * even if list execution is to be stopped. */
3136 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3139 #if ENABLE_HUSH_LOOPS
3140 G.flag_break_continue = 0;
3142 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3144 /* we only ran a builtin: rcode is already known
3145 * and we don't need to wait for anything. */
3146 check_and_run_traps(0);
3147 #if ENABLE_HUSH_LOOPS
3148 /* was it "break" or "continue"? */
3149 if (G.flag_break_continue) {
3150 smallint fbc = G.flag_break_continue;
3151 /* we might fall into outer *loop*,
3152 * don't want to break it too */
3154 G.depth_break_continue--;
3155 if (G.depth_break_continue == 0)
3156 G.flag_break_continue = 0;
3157 /* else: e.g. "continue 2" should *break* once, *then* continue */
3158 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3159 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3160 goto check_jobs_and_break;
3161 /* "continue": simulate end of loop */
3166 } else if (pi->followup == PIPE_BG) {
3167 /* what does bash do with attempts to background builtins? */
3168 /* even bash 3.2 doesn't do that well with nested bg:
3169 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3170 * I'm NOT treating inner &'s as jobs */
3171 check_and_run_traps(0);
3173 if (G.run_list_level == 1)
3176 rcode = 0; /* EXIT_SUCCESS */
3179 if (G.run_list_level == 1 && G.interactive_fd) {
3180 /* waits for completion, then fg's main shell */
3181 rcode = checkjobs_and_fg_shell(pi);
3182 check_and_run_traps(0);
3183 debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
3186 { /* this one just waits for completion */
3187 rcode = checkjobs(pi);
3188 check_and_run_traps(0);
3189 debug_printf_exec(": checkjobs returned %d\n", rcode);
3193 debug_printf_exec(": setting last_return_code=%d\n", rcode);
3194 G.last_return_code = rcode;
3196 /* Analyze how result affects subsequent commands */
3198 if (rword == RES_IF || rword == RES_ELIF)
3201 #if ENABLE_HUSH_LOOPS
3202 if (rword == RES_WHILE) {
3204 rcode = 0; /* "while false; do...done" - exitcode 0 */
3205 goto check_jobs_and_break;
3208 if (rword == RES_UNTIL) {
3210 check_jobs_and_break:
3216 if ((rcode == 0 && pi->followup == PIPE_OR)
3217 || (rcode != 0 && pi->followup == PIPE_AND)
3219 skip_more_for_this_rword = rword;
3222 check_jobs_and_continue:
3227 //// if (G.ctrl_z_flag) {
3228 //// /* ctrl-Z forked somewhere in the past, we are the child,
3229 //// * and now we completed running the list. Exit. */
3235 //// if (!G.run_list_level && G.interactive_fd) {
3236 //// signal(SIGTSTP, SIG_IGN);
3237 //// signal(SIGINT, SIG_IGN);
3240 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3241 #if ENABLE_HUSH_LOOPS
3246 #if ENABLE_HUSH_CASE
3252 /* Select which version we will use */
3253 static int run_and_free_list(struct pipe *pi)
3256 debug_printf_exec("run_and_free_list entered\n");
3258 debug_printf_exec(": run_list with %d members\n", pi->num_cmds);
3259 rcode = run_list(pi);
3261 /* free_pipe_list has the side effect of clearing memory.
3262 * In the long run that function can be merged with run_list,
3263 * but doing that now would hobble the debugging effort. */
3264 free_pipe_list(pi, /* indent: */ 0);
3265 debug_printf_exec("run_and_free_list return %d\n", rcode);
3270 /* Peek ahead in the in_str to find out if we have a "&n" construct,
3271 * as in "2>&1", that represents duplicating a file descriptor.
3272 * Return either -2 (syntax error), -1 (no &), or the number found.
3274 static int redirect_dup_num(struct in_str *input)
3276 int ch, d = 0, ok = 0;
3278 if (ch != '&') return -1;
3280 i_getch(input); /* get the & */
3284 return -3; /* "-" represents "close me" */
3286 while (isdigit(ch)) {
3287 d = d*10 + (ch-'0');
3294 bb_error_msg("ambiguous redirect");
3298 /* The src parameter allows us to peek forward to a possible &n syntax
3299 * for file descriptor duplication, e.g., "2>&1".
3300 * Return code is 0 normally, 1 if a syntax error is detected in src.
3301 * Resource errors (in xmalloc) cause the process to exit */
3302 static int setup_redirect(struct parse_context *ctx,
3305 struct in_str *input)
3307 struct command *command = ctx->command;
3308 struct redir_struct *redir;
3309 struct redir_struct **redirp;
3312 /* Check for a '2>&1' type redirect */
3313 dup_num = redirect_dup_num(input);
3315 return 1; /* syntax error */
3317 /* Create a new redir_struct and drop it onto the end of the linked list */
3318 redirp = &command->redirects;
3319 while ((redir = *redirp) != NULL) {
3320 redirp = &(redir->next);
3322 *redirp = redir = xzalloc(sizeof(*redir));
3323 /* redir->next = NULL; */
3324 /* redir->rd_filename = NULL; */
3325 redir->rd_type = style;
3326 redir->fd = (fd == -1) ? redir_table[style].default_fd : fd;
3328 debug_printf("Redirect type %d%s\n", redir->fd, redir_table[style].descrip);
3330 redir->dup = dup_num;
3331 if (dup_num != -1) {
3332 /* Erik had a check here that the file descriptor in question
3333 * is legit; I postpone that to "run time"
3334 * A "-" representation of "close me" shows up as a -3 here */
3335 debug_printf("Duplicating redirect '%d>&%d'\n", redir->fd, redir->dup);
3337 /* We do _not_ try to open the file that src points to,
3338 * since we need to return and let src be expanded first.
3339 * Set ctx->pending_redirect, so we know what to do at the
3340 * end of the next parsed word. */
3341 ctx->pending_redirect = redir;
3347 static struct pipe *new_pipe(void)
3350 pi = xzalloc(sizeof(struct pipe));
3351 /*pi->followup = 0; - deliberately invalid value */
3352 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3356 /* Command (member of a pipe) is complete. The only possible error here
3357 * is out of memory, in which case xmalloc exits. */
3358 static int done_command(struct parse_context *ctx)
3360 /* The command is really already in the pipe structure, so
3361 * advance the pipe counter and make a new, null command. */
3362 struct pipe *pi = ctx->pipe;
3363 struct command *command = ctx->command;
3366 if (command->group == NULL
3367 && command->argv == NULL
3368 && command->redirects == NULL
3370 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3371 return pi->num_cmds;
3374 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3376 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3379 /* Only real trickiness here is that the uncommitted
3380 * command structure is not counted in pi->num_cmds. */
3381 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3382 command = &pi->cmds[pi->num_cmds];
3383 memset(command, 0, sizeof(*command));
3385 ctx->command = command;
3386 /* but ctx->pipe and ctx->list_head remain unchanged */
3388 return pi->num_cmds; /* used only for 0/nonzero check */
3391 static void done_pipe(struct parse_context *ctx, pipe_style type)
3395 debug_printf_parse("done_pipe entered, followup %d\n", type);
3396 /* Close previous command */
3397 not_null = done_command(ctx);
3398 ctx->pipe->followup = type;
3399 IF_HAS_KEYWORDS(ctx->pipe->pi_inverted = ctx->ctx_inverted;)
3400 IF_HAS_KEYWORDS(ctx->ctx_inverted = 0;)
3401 IF_HAS_KEYWORDS(ctx->pipe->res_word = ctx->ctx_res_w;)
3403 /* Without this check, even just <enter> on command line generates
3404 * tree of three NOPs (!). Which is harmless but annoying.
3405 * IOW: it is safe to do it unconditionally.
3406 * RES_NONE case is for "for a in; do ..." (empty IN set)
3407 * to work, possibly other cases too. */
3408 if (not_null IF_HAS_KEYWORDS(|| ctx->ctx_res_w != RES_NONE)) {
3410 debug_printf_parse("done_pipe: adding new pipe: "
3411 "not_null:%d ctx->ctx_res_w:%d\n",
3412 not_null, ctx->ctx_res_w);
3414 ctx->pipe->next = new_p;
3416 /* RES_THEN, RES_DO etc are "sticky" -
3417 * they remain set for commands inside if/while.
3418 * This is used to control execution.
3419 * RES_FOR and RES_IN are NOT sticky (needed to support
3420 * cases where variable or value happens to match a keyword):
3422 #if ENABLE_HUSH_LOOPS
3423 if (ctx->ctx_res_w == RES_FOR
3424 || ctx->ctx_res_w == RES_IN)
3425 ctx->ctx_res_w = RES_NONE;
3427 #if ENABLE_HUSH_CASE
3428 if (ctx->ctx_res_w == RES_MATCH)
3429 ctx->ctx_res_w = RES_CASEI;
3431 ctx->command = NULL; /* trick done_command below */
3432 /* Create the memory for command, roughly:
3433 * ctx->pipe->cmds = new struct command;
3434 * ctx->command = &ctx->pipe->cmds[0];
3438 debug_printf_parse("done_pipe return\n");
3441 static void initialize_context(struct parse_context *ctx)
3443 memset(ctx, 0, sizeof(*ctx));
3444 ctx->pipe = ctx->list_head = new_pipe();
3445 /* Create the memory for command, roughly:
3446 * ctx->pipe->cmds = new struct command;
3447 * ctx->command = &ctx->pipe->cmds[0];
3453 /* If a reserved word is found and processed, parse context is modified
3454 * and 1 is returned.
3457 struct reserved_combo {
3460 unsigned char assignment_flag;
3464 FLAG_END = (1 << RES_NONE ),
3466 FLAG_IF = (1 << RES_IF ),
3467 FLAG_THEN = (1 << RES_THEN ),
3468 FLAG_ELIF = (1 << RES_ELIF ),
3469 FLAG_ELSE = (1 << RES_ELSE ),
3470 FLAG_FI = (1 << RES_FI ),
3472 #if ENABLE_HUSH_LOOPS
3473 FLAG_FOR = (1 << RES_FOR ),
3474 FLAG_WHILE = (1 << RES_WHILE),
3475 FLAG_UNTIL = (1 << RES_UNTIL),
3476 FLAG_DO = (1 << RES_DO ),
3477 FLAG_DONE = (1 << RES_DONE ),
3478 FLAG_IN = (1 << RES_IN ),
3480 #if ENABLE_HUSH_CASE
3481 FLAG_MATCH = (1 << RES_MATCH),
3482 FLAG_ESAC = (1 << RES_ESAC ),
3484 FLAG_START = (1 << RES_XXXX ),
3487 static const struct reserved_combo* match_reserved_word(o_string *word)
3489 /* Mostly a list of accepted follow-up reserved words.
3490 * FLAG_END means we are done with the sequence, and are ready
3491 * to turn the compound list into a command.
3492 * FLAG_START means the word must start a new compound list.
3494 static const struct reserved_combo reserved_list[] = {
3496 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3497 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3498 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3499 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3500 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3501 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3503 #if ENABLE_HUSH_LOOPS
3504 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3505 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3506 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3507 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3508 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3509 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3511 #if ENABLE_HUSH_CASE
3512 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3513 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3516 const struct reserved_combo *r;
3518 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3519 if (strcmp(word->data, r->literal) == 0)
3524 static int reserved_word(o_string *word, struct parse_context *ctx)
3526 #if ENABLE_HUSH_CASE
3527 static const struct reserved_combo reserved_match = {
3528 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3531 const struct reserved_combo *r;
3533 r = match_reserved_word(word);
3537 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3538 #if ENABLE_HUSH_CASE
3539 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3540 /* "case word IN ..." - IN part starts first match part */
3541 r = &reserved_match;
3544 if (r->flag == 0) { /* '!' */
3545 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3546 syntax("! ! command");
3547 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3549 ctx->ctx_inverted = 1;
3552 if (r->flag & FLAG_START) {
3553 struct parse_context *old;
3554 old = xmalloc(sizeof(*old));
3555 debug_printf_parse("push stack %p\n", old);
3556 *old = *ctx; /* physical copy */
3557 initialize_context(ctx);
3559 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3561 ctx->ctx_res_w = RES_SNTX;
3564 ctx->ctx_res_w = r->res;
3565 ctx->old_flag = r->flag;
3566 if (ctx->old_flag & FLAG_END) {
3567 struct parse_context *old;
3568 done_pipe(ctx, PIPE_SEQ);
3569 debug_printf_parse("pop stack %p\n", ctx->stack);
3571 old->command->group = ctx->list_head;
3572 old->command->grp_type = GRP_NORMAL;
3573 *ctx = *old; /* physical copy */
3576 word->o_assignment = r->assignment_flag;
3581 /* Word is complete, look at it and update parsing context.
3582 * Normal return is 0. Syntax errors return 1.
3583 * Note: on return, word is reset, but not o_free'd!
3585 static int done_word(o_string *word, struct parse_context *ctx)
3587 struct command *command = ctx->command;
3589 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3590 if (word->length == 0 && word->nonnull == 0) {
3591 debug_printf_parse("done_word return 0: true null, ignored\n");
3594 /* If this word wasn't an assignment, next ones definitely
3595 * can't be assignments. Even if they look like ones. */
3596 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3597 && word->o_assignment != WORD_IS_KEYWORD
3599 word->o_assignment = NOT_ASSIGNMENT;
3601 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3602 command->assignment_cnt++;
3603 word->o_assignment = MAYBE_ASSIGNMENT;
3606 if (ctx->pending_redirect) {
3607 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3608 * only if run as "bash", not "sh" */
3609 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3610 word->o_assignment = NOT_ASSIGNMENT;
3611 debug_printf("word stored in rd_filename: '%s'\n", word->data);
3613 /* "{ echo foo; } echo bar" - bad */
3614 /* NB: bash allows e.g.:
3615 * if true; then { echo foo; } fi
3616 * while if false; then false; fi do break; done
3618 if (command->group) {
3620 debug_printf_parse("done_word return 1: syntax error, "
3621 "groups and arglists don't mix\n");
3625 #if ENABLE_HUSH_CASE
3626 if (ctx->ctx_dsemicolon
3627 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3629 /* already done when ctx_dsemicolon was set to 1: */
3630 /* ctx->ctx_res_w = RES_MATCH; */
3631 ctx->ctx_dsemicolon = 0;
3634 if (!command->argv /* if it's the first word... */
3635 #if ENABLE_HUSH_LOOPS
3636 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3637 && ctx->ctx_res_w != RES_IN
3640 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3641 if (reserved_word(word, ctx)) {
3643 debug_printf_parse("done_word return %d\n", (ctx->ctx_res_w == RES_SNTX));
3644 return (ctx->ctx_res_w == RES_SNTX);
3648 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3649 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3650 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3651 /* (otherwise it's known to be not empty and is already safe) */
3653 /* exclude "$@" - it can expand to no word despite "" */
3654 char *p = word->data;
3655 while (p[0] == SPECIAL_VAR_SYMBOL
3656 && (p[1] & 0x7f) == '@'
3657 && p[2] == SPECIAL_VAR_SYMBOL
3661 if (p == word->data || p[0] != '\0') {
3662 /* saw no "$@", or not only "$@" but some
3663 * real text is there too */
3664 /* insert "empty variable" reference, this makes
3665 * e.g. "", $empty"" etc to not disappear */
3666 o_addchr(word, SPECIAL_VAR_SYMBOL);
3667 o_addchr(word, SPECIAL_VAR_SYMBOL);
3670 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3671 debug_print_strings("word appended to argv", command->argv);
3675 ctx->pending_redirect = NULL;
3677 #if ENABLE_HUSH_LOOPS
3678 /* Force FOR to have just one word (variable name) */
3679 /* NB: basically, this makes hush see "for v in ..." syntax as if
3680 * as it is "for v; in ...". FOR and IN become two pipe structs
3682 if (ctx->ctx_res_w == RES_FOR) {
3683 //TODO: check that command->argv[0] is a valid variable name!
3684 done_pipe(ctx, PIPE_SEQ);
3687 #if ENABLE_HUSH_CASE
3688 /* Force CASE to have just one word */
3689 if (ctx->ctx_res_w == RES_CASE) {
3690 done_pipe(ctx, PIPE_SEQ);
3693 debug_printf_parse("done_word return 0\n");
3697 /* If a redirect is immediately preceded by a number, that number is
3698 * supposed to tell which file descriptor to redirect. This routine
3699 * looks for such preceding numbers. In an ideal world this routine
3700 * needs to handle all the following classes of redirects...
3701 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3702 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3703 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3704 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3705 * A -1 output from this program means no valid number was found, so the
3706 * caller should use the appropriate default for this redirection.
3708 static int redirect_opt_num(o_string *o)
3714 for (num = 0; num < o->length; num++) {
3715 if (!isdigit(o->data[num])) {
3719 num = atoi(o->data);
3724 static struct pipe *parse_stream(struct in_str *input, int end_trigger);
3726 #if ENABLE_HUSH_TICK
3727 static FILE *generate_stream_from_list(struct pipe *head)
3730 int pid, channel[2];
3733 /* *** NOMMU WARNING *** */
3734 /* By using vfork here, we suspend parent till child exits or execs.
3735 * If child will not do it before it fills the pipe, it can block forever
3736 * in write(STDOUT_FILENO), and parent (shell) will be also stuck.
3738 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >TESTFILE
3739 * huge=`cat TESTFILE` # will block here forever
3742 pid = BB_MMU ? fork() : vfork();
3744 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
3745 if (pid == 0) { /* child */
3746 if (ENABLE_HUSH_JOB)
3747 die_sleep = 0; /* let nofork's xfuncs die */
3748 close(channel[0]); /* NB: close _first_, then move fd! */
3749 xmove_fd(channel[1], 1);
3750 /* Prevent it from trying to handle ctrl-z etc */
3752 G.run_list_level = 1;
3754 /* Process substitution is not considered to be usual
3755 * 'command execution'.
3756 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
3758 set_jobctrl_signals_to_IGN();
3760 /* Note: freeing 'head' here would break NOMMU. */
3761 _exit(run_list(head));
3764 pf = fdopen(channel[0], "r");
3766 /* 'head' is freed by the caller */
3769 /* Return code is exit status of the process that is run. */
3770 static int process_command_subs(o_string *dest,
3771 struct in_str *input)
3773 int retcode, ch, eol_cnt;
3774 struct pipe *pipe_list;
3776 struct in_str pipe_str;
3778 /* Recursion to generate command */
3779 pipe_list = parse_stream(input, '\0');
3780 if (pipe_list == NULL)
3781 return 0; /* EOF: empty `cmd`: ``, ` ` etc */
3782 if (pipe_list == ERR_PTR)
3783 return 1; /* parse error. can this really happen? */
3785 p = generate_stream_from_list(pipe_list);
3786 free_pipe_list(pipe_list, /* indent: */ 0);
3789 close_on_exec_on(fileno(p));
3791 /* Now send results of command back into original context */
3792 setup_file_in_str(&pipe_str, p);
3794 while ((ch = i_getch(&pipe_str)) != EOF) {
3800 o_addchr(dest, '\n');
3803 o_addQchr(dest, ch);
3806 debug_printf("done reading from pipe, pclose()ing\n");
3807 /* Note: we got EOF, and we just close the read end of the pipe.
3808 * We do not wait for the `cmd` child to terminate. bash and ash do.
3810 * echo `echo Hi; exec 1>&-; sleep 2`
3812 retcode = fclose(p);
3813 debug_printf("closed FILE from child, retcode=%d\n", retcode);
3818 static int parse_group(o_string *dest, struct parse_context *ctx,
3819 struct in_str *input, int ch)
3821 /* dest contains characters seen prior to ( or {.
3822 * Typically it's empty, but for function defs,
3823 * it contains function name (without '()'). */
3824 struct pipe *pipe_list;
3826 struct command *command = ctx->command;
3828 debug_printf_parse("parse_group entered\n");
3829 #if ENABLE_HUSH_FUNCTIONS
3830 if (ch == 'F') { /* function definition? */
3831 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
3832 //command->fname = dest->data;
3833 command->grp_type = GRP_FUNCTION;
3834 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
3835 memset(dest, 0, sizeof(*dest));
3838 if (command->argv /* word [word](... */
3839 || dest->length /* word(... */
3840 || dest->nonnull /* ""(... */
3843 debug_printf_parse("parse_group return 1: syntax error, groups and arglists don't mix\n");
3849 command->grp_type = GRP_SUBSHELL;
3851 pipe_list = parse_stream(input, endch);
3852 /* empty ()/{} or parse error? */
3853 if (!pipe_list || pipe_list == ERR_PTR) {
3855 debug_printf_parse("parse_group return 1: parse_stream returned %p\n", pipe_list);
3858 command->group = pipe_list;
3859 debug_printf_parse("parse_group return 0\n");
3861 /* command remains "open", available for possible redirects */
3864 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
3865 /* Subroutines for copying $(...) and `...` things */
3866 static void add_till_backquote(o_string *dest, struct in_str *input);
3868 static void add_till_single_quote(o_string *dest, struct in_str *input)
3871 int ch = i_getch(input);
3879 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3880 static void add_till_double_quote(o_string *dest, struct in_str *input)
3883 int ch = i_getch(input);
3886 if (ch == '\\') { /* \x. Copy both chars. */
3888 ch = i_getch(input);
3894 add_till_backquote(dest, input);
3898 //if (ch == '$') ...
3901 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3903 * "Within the backquoted style of command substitution, backslash
3904 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3905 * The search for the matching backquote shall be satisfied by the first
3906 * backquote found without a preceding backslash; during this search,
3907 * if a non-escaped backquote is encountered within a shell comment,
3908 * a here-document, an embedded command substitution of the $(command)
3909 * form, or a quoted string, undefined results occur. A single-quoted
3910 * or double-quoted string that begins, but does not end, within the
3911 * "`...`" sequence produces undefined results."
3913 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3915 static void add_till_backquote(o_string *dest, struct in_str *input)
3918 int ch = i_getch(input);
3921 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
3922 int ch2 = i_getch(input);
3923 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
3932 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3933 * quoting and nested ()s.
3934 * "With the $(command) style of command substitution, all characters
3935 * following the open parenthesis to the matching closing parenthesis
3936 * constitute the command. Any valid shell script can be used for command,
3937 * except a script consisting solely of redirections which produces
3938 * unspecified results."
3940 * echo $(echo '(TEST)' BEST) (TEST) BEST
3941 * echo $(echo 'TEST)' BEST) TEST) BEST
3942 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3944 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
3948 int ch = i_getch(input);
3957 if (i_peek(input) == ')') {
3964 add_till_single_quote(dest, input);
3969 add_till_double_quote(dest, input);
3973 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
3974 ch = i_getch(input);
3982 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
3984 /* Return code: 0 for OK, 1 for syntax error */
3985 static int handle_dollar(o_string *dest, struct in_str *input)
3988 int ch = i_peek(input); /* first character after the $ */
3989 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
3991 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
3995 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3997 debug_printf_parse(": '%c'\n", ch);
3998 o_addchr(dest, ch | quote_mask);
4001 if (!isalnum(ch) && ch != '_')
4005 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4006 } else if (isdigit(ch)) {
4009 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4010 debug_printf_parse(": '%c'\n", ch);
4011 o_addchr(dest, ch | quote_mask);
4012 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4013 } else switch (ch) {
4015 case '!': /* last bg pid */
4016 case '?': /* last exit code */
4017 case '#': /* number of args */
4018 case '*': /* args */
4019 case '@': /* args */
4020 goto make_one_char_var;
4022 bool first_char, all_digits;
4024 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4026 /* XXX maybe someone will try to escape the '}' */
4031 ch = i_getch(input);
4037 /* ${#var}: length of var contents */
4039 else if (isdigit(ch)) {
4045 if (expansion < 2 &&
4046 ((all_digits && !isdigit(ch)) ||
4047 (!all_digits && !isalnum(ch) && ch != '_')))
4049 /* handle parameter expansions
4050 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4055 case ':': /* null modifier */
4056 if (expansion == 0) {
4057 debug_printf_parse(": null modifier\n");
4063 #if 0 /* not implemented yet :( */
4064 case '#': /* remove prefix */
4065 case '%': /* remove suffix */
4066 if (expansion == 0) {
4067 debug_printf_parse(": remove suffix/prefix\n");
4074 case '-': /* default value */
4075 case '=': /* assign default */
4076 case '+': /* alternative */
4077 case '?': /* error indicate */
4078 debug_printf_parse(": parameter expansion\n");
4084 syntax("unterminated ${name}");
4085 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4091 debug_printf_parse(": '%c'\n", ch);
4092 o_addchr(dest, ch | quote_mask);
4096 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4102 #if ENABLE_SH_MATH_SUPPORT
4103 if (i_peek(input) == '(') {
4105 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4106 o_addchr(dest, /*quote_mask |*/ '+');
4107 add_till_closing_paren(dest, input, true);
4108 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4113 #if ENABLE_HUSH_TICK
4114 //int pos = dest->length;
4115 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4116 o_addchr(dest, quote_mask | '`');
4117 add_till_closing_paren(dest, input, false);
4118 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4119 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4126 if (isalnum(ch)) { /* it's $_name or $_123 */
4132 /* still unhandled, but should be eventually */
4133 bb_error_msg("unhandled syntax: $%c", ch);
4137 o_addQchr(dest, '$');
4139 debug_printf_parse("handle_dollar return 0\n");
4143 static int parse_stream_dquoted(o_string *dest, struct in_str *input, int dquote_end)
4149 ch = i_getch(input);
4150 if (ch == dquote_end) { /* may be only '"' or EOF */
4152 if (dest->o_assignment == NOT_ASSIGNMENT)
4153 dest->o_escape ^= 1;
4154 debug_printf_parse("parse_stream_dquoted return 0\n");
4158 syntax("unterminated \"");
4159 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4165 next = i_peek(input);
4167 debug_printf_parse(": ch=%c (%d) m=%d escape=%d\n",
4168 ch, ch, m, dest->o_escape);
4169 /* Basically, checking every CHAR_SPECIAL char except '"' */
4173 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4177 * "The backslash retains its special meaning [in "..."]
4178 * only when followed by one of the following characters:
4179 * $, `, ", \, or <newline>. A double quote may be quoted
4180 * within double quotes by preceding it with a backslash.
4181 * If enabled, history expansion will be performed unless
4182 * an ! appearing in double quotes is escaped using
4183 * a backslash. The backslash preceding the ! is not removed."
4185 if (strchr("$`\"\\", next) != NULL) {
4186 o_addqchr(dest, i_getch(input));
4188 o_addqchr(dest, '\\');
4193 if (handle_dollar(dest, input) != 0) {
4194 debug_printf_parse("parse_stream_dquoted return 1: handle_dollar returned non-0\n");
4199 #if ENABLE_HUSH_TICK
4201 //int pos = dest->length;
4202 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4203 o_addchr(dest, 0x80 | '`');
4204 add_till_backquote(dest, input);
4205 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4206 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4210 o_addQchr(dest, ch);
4212 && (dest->o_assignment == MAYBE_ASSIGNMENT
4213 || dest->o_assignment == WORD_IS_KEYWORD)
4214 && is_assignment(dest->data)
4216 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4222 * Scan input until EOF or end_trigger char.
4223 * Return a list of pipes to execute, or NULL on EOF
4224 * or if end_trigger character is met.
4225 * On syntax error, exit is shell is not interactive,
4226 * reset parsing machinery and start parsing anew,
4227 * or return ERR_PTR.
4229 static struct pipe *parse_stream(struct in_str *input, int end_trigger)
4231 struct parse_context ctx;
4232 o_string dest = NULL_O_STRING;
4235 redir_type redir_style;
4239 /* Double-quote state is handled in the state variable is_in_dquote.
4240 * A single-quote triggers a bypass of the main loop until its mate is
4241 * found. When recursing, quote state is passed in via dest->o_escape. */
4243 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4244 end_trigger ? : 'X');
4247 #if ENABLE_HUSH_INTERACTIVE
4248 input->promptmode = 0; /* PS1 */
4250 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4251 initialize_context(&ctx);
4255 if (parse_stream_dquoted(&dest, input, '"')) {
4258 /* We reached closing '"' */
4263 ch = i_getch(input);
4267 next = i_peek(input);
4270 debug_printf_parse(": ch=%c (%d) m=%d escape=%d\n",
4271 ch, ch, m, dest.o_escape);
4272 if (m == CHAR_ORDINARY) {
4273 o_addQchr(&dest, ch);
4274 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4275 || dest.o_assignment == WORD_IS_KEYWORD)
4277 && is_assignment(dest.data)
4279 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4284 /* m is SPECIAL ($,`), IFS, or ORDINARY_IF_QUOTED (*,#) */
4286 if (m == CHAR_IFS) {
4289 if (done_word(&dest, &ctx)) {
4293 done_pipe(&ctx, PIPE_SEQ);
4294 /* If we got nothing... */
4296 if (pi->num_cmds == 0
4297 && pi->res_word == RES_NONE
4299 free_pipe_list(pi, 0);
4302 debug_printf_parse("parse_stream return %p\n", pi);
4305 if (done_word(&dest, &ctx)) {
4309 #if ENABLE_HUSH_CASE
4310 /* "case ... in <newline> word) ..." -
4311 * newlines are ignored (but ';' wouldn't be) */
4312 if (ctx.command->argv == NULL
4313 && ctx.ctx_res_w == RES_MATCH
4318 /* Treat newline as a command separator. */
4319 done_pipe(&ctx, PIPE_SEQ);
4320 dest.o_assignment = MAYBE_ASSIGNMENT;
4322 /* note: if (m == CHAR_IFS) continue;
4323 * will still trigger for us */
4326 if (end_trigger && end_trigger == ch) {
4327 //TODO: disallow "{ cmd }" without semicolon
4328 if (done_word(&dest, &ctx)) {
4331 done_pipe(&ctx, PIPE_SEQ);
4332 dest.o_assignment = MAYBE_ASSIGNMENT;
4333 /* Do we sit outside of any if's, loops or case's? */
4335 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4337 debug_printf_parse("parse_stream return %p: "
4338 "end_trigger char found\n",
4341 return ctx.list_head;
4347 /* m is SPECIAL (e.g. $,`) or ORDINARY_IF_QUOTED (*,#) */
4349 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4350 /* ch is a special char and thus this word
4351 * cannot be an assignment */
4352 dest.o_assignment = NOT_ASSIGNMENT;
4357 if (dest.length == 0) {
4360 if (ch == EOF || ch == '\n')
4365 o_addQchr(&dest, ch);
4373 o_addchr(&dest, '\\');
4374 o_addchr(&dest, i_getch(input));
4377 if (handle_dollar(&dest, input) != 0) {
4378 debug_printf_parse("parse_stream parse error: handle_dollar returned non-0\n");
4385 ch = i_getch(input);
4387 syntax("unterminated '");
4392 if (dest.o_assignment == NOT_ASSIGNMENT)
4393 o_addqchr(&dest, ch);
4395 o_addchr(&dest, ch);
4400 is_in_dquote ^= 1; /* invert */
4401 if (dest.o_assignment == NOT_ASSIGNMENT)
4404 #if ENABLE_HUSH_TICK
4406 //int pos = dest.length;
4407 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4408 o_addchr(&dest, '`');
4409 add_till_backquote(&dest, input);
4410 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4411 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4416 redir_fd = redirect_opt_num(&dest);
4417 if (done_word(&dest, &ctx)) {
4420 redir_style = REDIRECT_OVERWRITE;
4422 redir_style = REDIRECT_APPEND;
4426 else if (next == '(') {
4427 syntax(">(process) not supported");
4431 setup_redirect(&ctx, redir_fd, redir_style, input);
4434 redir_fd = redirect_opt_num(&dest);
4435 if (done_word(&dest, &ctx)) {
4438 redir_style = REDIRECT_INPUT;
4440 redir_style = REDIRECT_HEREIS;
4442 } else if (next == '>') {
4443 redir_style = REDIRECT_IO;
4447 else if (next == '(') {
4448 syntax("<(process) not supported");
4452 setup_redirect(&ctx, redir_fd, redir_style, input);
4455 #if ENABLE_HUSH_CASE
4458 if (done_word(&dest, &ctx)) {
4461 done_pipe(&ctx, PIPE_SEQ);
4462 #if ENABLE_HUSH_CASE
4463 /* Eat multiple semicolons, detect
4464 * whether it means something special */
4470 if (ctx.ctx_res_w == RES_CASEI) {
4471 ctx.ctx_dsemicolon = 1;
4472 ctx.ctx_res_w = RES_MATCH;
4478 /* We just finished a cmd. New one may start
4479 * with an assignment */
4480 dest.o_assignment = MAYBE_ASSIGNMENT;
4483 if (done_word(&dest, &ctx)) {
4488 done_pipe(&ctx, PIPE_AND);
4490 done_pipe(&ctx, PIPE_BG);
4494 if (done_word(&dest, &ctx)) {
4497 #if ENABLE_HUSH_CASE
4498 if (ctx.ctx_res_w == RES_MATCH)
4499 break; /* we are in case's "word | word)" */
4501 if (next == '|') { /* || */
4503 done_pipe(&ctx, PIPE_OR);
4505 /* we could pick up a file descriptor choice here
4506 * with redirect_opt_num(), but bash doesn't do it.
4507 * "echo foo 2| cat" yields "foo 2". */
4512 #if ENABLE_HUSH_CASE
4513 /* "case... in [(]word)..." - skip '(' */
4514 if (ctx.ctx_res_w == RES_MATCH
4515 && ctx.command->argv == NULL /* not (word|(... */
4516 && dest.length == 0 /* not word(... */
4517 && dest.nonnull == 0 /* not ""(... */
4522 #if ENABLE_HUSH_FUNCTIONS
4523 if (dest.length != 0 /* not just () but word() */
4524 && dest.nonnull == 0 /* not a"b"c() */
4525 && ctx.command->argv == NULL /* it's the first word */
4526 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
4527 && i_peek(input) == ')'
4528 && !match_reserved_word(&dest)
4530 bb_error_msg("seems like a function definition");
4533 //TODO: do it properly.
4534 ch = i_getch(input);
4535 } while (ch == ' ' || ch == '\n');
4537 syntax("was expecting {");
4540 ch = 'F'; /* magic value */
4544 if (parse_group(&dest, &ctx, input, ch) != 0) {
4549 #if ENABLE_HUSH_CASE
4550 if (ctx.ctx_res_w == RES_MATCH)
4554 /* proper use of this character is caught by end_trigger:
4555 * if we see {, we call parse_group(..., end_trigger='}')
4556 * and it will match } earlier (not here). */
4557 syntax("unexpected } or )");
4561 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4567 struct parse_context *pctx, *p2;
4569 /* Clean up allocated tree.
4570 * Samples for finding leaks on syntax error recovery path.
4571 * Execute them from interactive shell and watch pmap `pidof hush`.
4572 * while if false; then false; fi do break; done (bash accepts it)
4573 * while if false; then false; fi; do break; fi
4577 /* Update pipe/command counts,
4578 * otherwise freeing may miss some */
4579 done_pipe(pctx, PIPE_SEQ);
4580 debug_printf_clean("freeing list %p from ctx %p\n",
4581 pctx->list_head, pctx);
4582 debug_print_tree(pctx->list_head, 0);
4583 free_pipe_list(pctx->list_head, 0);
4584 debug_printf_clean("freed list %p\n", pctx->list_head);
4591 /* Free text, clear all dest fields */
4593 /* If we are not in top-level parse, we return,
4594 * our caller will propagate error.
4596 if (end_trigger != ';')
4598 /* Discard cached input, force prompt */
4600 input->promptme = 1;
4605 static void set_in_charmap(const char *set, int code)
4608 G.charmap[(unsigned char)*set++] = code;
4611 static void update_charmap(void)
4613 G.ifs = getenv("IFS");
4616 /* Precompute a list of 'flow through' behavior so it can be treated
4617 * quickly up front. Computation is necessary because of IFS.
4618 * Special case handling of IFS == " \t\n" is not implemented.
4619 * The charmap[] array only really needs two bits each,
4620 * and on most machines that would be faster (reduced L1 cache use).
4622 memset(G.charmap, CHAR_ORDINARY, sizeof(G.charmap));
4623 #if ENABLE_HUSH_TICK
4624 set_in_charmap("\\$\"`", CHAR_SPECIAL);
4626 set_in_charmap("\\$\"", CHAR_SPECIAL);
4628 set_in_charmap("<>;&|(){}#'", CHAR_ORDINARY_IF_QUOTED);
4629 set_in_charmap(G.ifs, CHAR_IFS); /* are ordinary if quoted */
4632 /* Execiting from string: eval, sh -c '...'
4633 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
4634 * end_trigger controls how often we stop parsing
4635 * NUL: parse all, execute, return
4636 * ';': parse till ';' or newline, execute, repeat till EOF
4638 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
4641 struct pipe *pipe_list;
4645 pipe_list = parse_stream(inp, end_trigger);
4646 if (!pipe_list) /* EOF */
4648 debug_print_tree(pipe_list, 0);
4649 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
4650 run_and_free_list(pipe_list);
4651 /* Loop on syntax errors, return on EOF: */
4655 static void parse_and_run_string(const char *s)
4657 struct in_str input;
4658 setup_string_in_str(&input, s);
4659 parse_and_run_stream(&input, '\0');
4662 static void parse_and_run_file(FILE *f)
4664 struct in_str input;
4665 setup_file_in_str(&input, f);
4666 parse_and_run_stream(&input, ';');
4670 /* Make sure we have a controlling tty. If we get started under a job
4671 * aware app (like bash for example), make sure we are now in charge so
4672 * we don't fight over who gets the foreground */
4673 static void setup_job_control(void)
4677 shell_pgrp = getpgrp();
4679 /* If we were ran as 'hush &',
4680 * sleep until we are in the foreground. */
4681 while (tcgetpgrp(G.interactive_fd) != shell_pgrp) {
4682 /* Send TTIN to ourself (should stop us) */
4683 kill(- shell_pgrp, SIGTTIN);
4684 shell_pgrp = getpgrp();
4687 /* We _must_ restore tty pgrp on fatal signals */
4688 set_fatal_signals_to_sigexit();
4690 /* Put ourselves in our own process group. */
4691 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
4692 /* Grab control of the terminal. */
4693 tcsetpgrp(G.interactive_fd, getpid());
4697 static int set_mode(const char cstate, const char mode)
4699 int state = (cstate == '-' ? 1 : 0);
4701 case 'n': G.fake_mode = state; break;
4702 case 'x': /*G.debug_mode = state;*/ break;
4703 default: return EXIT_FAILURE;
4705 return EXIT_SUCCESS;
4708 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4709 int hush_main(int argc, char **argv)
4711 static const struct variable const_shell_ver = {
4713 .varstr = (char*)hush_version_str,
4714 .max_len = 1, /* 0 can provoke free(name) */
4722 struct variable *cur_var;
4726 G.root_pid = getpid();
4728 /* Deal with HUSH_VERSION */
4729 G.shell_ver = const_shell_ver; /* copying struct here */
4730 G.top_var = &G.shell_ver;
4731 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
4732 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
4733 /* Initialize our shell local variables with the values
4734 * currently living in the environment */
4735 cur_var = G.top_var;
4738 char *value = strchr(*e, '=');
4739 if (value) { /* paranoia */
4740 cur_var->next = xzalloc(sizeof(*cur_var));
4741 cur_var = cur_var->next;
4742 cur_var->varstr = *e;
4743 cur_var->max_len = strlen(*e);
4744 cur_var->flg_export = 1;
4748 debug_printf_env("putenv '%s'\n", hush_version_str);
4749 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
4751 #if ENABLE_FEATURE_EDITING
4752 G.line_input_state = new_line_input_t(FOR_SHELL);
4754 /* XXX what should these be while sourcing /etc/profile? */
4755 G.global_argc = argc;
4756 G.global_argv = argv;
4757 /* Initialize some more globals to non-zero values */
4759 #if ENABLE_HUSH_INTERACTIVE
4760 if (ENABLE_FEATURE_EDITING)
4761 cmdedit_set_initial_prompt();
4765 if (EXIT_SUCCESS) /* otherwise is already done */
4766 G.last_return_code = EXIT_SUCCESS;
4768 if (argv[0] && argv[0][0] == '-') {
4769 debug_printf("sourcing /etc/profile\n");
4770 input = fopen_for_read("/etc/profile");
4771 if (input != NULL) {
4772 close_on_exec_on(fileno(input));
4773 parse_and_run_file(input);
4779 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
4780 while ((opt = getopt(argc, argv, "c:xins")) > 0) {
4783 G.global_argv = argv + optind;
4784 if (!argv[optind]) {
4785 /* -c 'script' (no params): prevent empty $0 */
4786 *--G.global_argv = argv[0];
4788 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
4789 G.global_argc = argc - optind;
4790 parse_and_run_string(optarg);
4793 /* Well, we cannot just declare interactiveness,
4794 * we have to have some stuff (ctty, etc) */
4795 /* G.interactive_fd++; */
4798 /* "-s" means "read from stdin", but this is how we always
4799 * operate, so simply do nothing here. */
4803 if (!set_mode('-', opt))
4807 fprintf(stderr, "Usage: sh [FILE]...\n"
4808 " or: sh -c command [args]...\n\n");
4816 /* A shell is interactive if the '-i' flag was given, or if all of
4817 * the following conditions are met:
4819 * no arguments remaining or the -s flag given
4820 * standard input is a terminal
4821 * standard output is a terminal
4822 * Refer to Posix.2, the description of the 'sh' utility. */
4823 if (argv[optind] == NULL && input == stdin
4824 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4826 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
4827 debug_printf("saved_tty_pgrp=%d\n", G.saved_tty_pgrp);
4828 if (G.saved_tty_pgrp >= 0) {
4829 /* try to dup to high fd#, >= 255 */
4830 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4831 if (G.interactive_fd < 0) {
4832 /* try to dup to any fd */
4833 G.interactive_fd = dup(STDIN_FILENO);
4834 if (G.interactive_fd < 0)
4836 G.interactive_fd = 0;
4838 // TODO: track & disallow any attempts of user
4839 // to (inadvertently) close/redirect it
4842 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4843 debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
4844 if (G.interactive_fd) {
4845 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4846 /* Looks like they want an interactive shell */
4847 setup_job_control();
4848 /* -1 is special - makes xfuncs longjmp, not exit
4849 * (we reset die_sleep = 0 whereever we [v]fork) */
4851 if (setjmp(die_jmp)) {
4852 /* xfunc has failed! die die die */
4853 hush_exit(xfunc_error_retval);
4856 #elif ENABLE_HUSH_INTERACTIVE
4857 /* no job control compiled, only prompt/line editing */
4858 if (argv[optind] == NULL && input == stdin
4859 && isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
4861 G.interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
4862 if (G.interactive_fd < 0) {
4863 /* try to dup to any fd */
4864 G.interactive_fd = dup(STDIN_FILENO);
4865 if (G.interactive_fd < 0)
4867 G.interactive_fd = 0;
4869 if (G.interactive_fd) {
4870 fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
4873 init_signal_mask(); /* note: ensures SIGCHLD is not masked */
4875 /* POSIX allows shell to re-enable SIGCHLD
4876 * even if it was SIG_IGN on entry */
4877 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
4878 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
4880 #if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
4881 if (G.interactive_fd) {
4882 printf("\n\n%s hush - the humble shell v"HUSH_VER_STR"\n", bb_banner);
4883 printf("Enter 'help' for a list of built-in commands.\n\n");
4887 if (argv[optind] == NULL) {
4888 parse_and_run_file(stdin);
4890 debug_printf("\nrunning script '%s'\n", argv[optind]);
4891 G.global_argv = argv + optind;
4892 G.global_argc = argc - optind;
4893 input = xfopen_for_read(argv[optind]);
4894 fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
4895 parse_and_run_file(input);
4900 #if ENABLE_FEATURE_CLEAN_UP
4902 if (G.cwd != bb_msg_unknown)
4904 cur_var = G.top_var->next;
4906 struct variable *tmp = cur_var;
4907 if (!cur_var->max_len)
4908 free(cur_var->varstr);
4909 cur_var = cur_var->next;
4913 hush_exit(G.last_return_code);
4918 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
4919 int lash_main(int argc, char **argv)
4921 //bb_error_msg("lash is deprecated, please use hush instead");
4922 return hush_main(argc, argv);
4930 static int builtin_trap(char **argv)
4937 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
4940 /* No args: print all trapped. This isn't 100% correct as we should
4941 * be escaping the cmd so that it can be pasted back in ...
4943 for (i = 0; i < NSIG; ++i)
4945 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
4946 return EXIT_SUCCESS;
4951 /* if first arg is decimal: reset all specified */
4952 sig = bb_strtou(*++argv, NULL, 10);
4958 sig = get_signum(*argv++);
4959 if (sig < 0 || sig >= NSIG) {
4961 /* mimic bash message exactly */
4962 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
4967 G.traps[sig] = xstrdup(new_cmd);
4969 debug_printf("trap: setting SIG%s (%i) to '%s'",
4970 get_signame(sig), sig, G.traps[sig]);
4972 /* There is no signal for 0 (EXIT) */
4977 sigaddset(&G.blocked_set, sig);
4979 /* there was a trap handler, we are removing it
4980 * (if sig has non-DFL handling,
4981 * we don't need to do anything) */
4982 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
4984 sigdelset(&G.blocked_set, sig);
4986 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
4991 /* first arg is "-": reset all specified to default */
4992 /* first arg is "": ignore all specified */
4993 /* everything else: execute first arg upon signal */
4995 bb_error_msg("trap: invalid arguments");
4996 return EXIT_FAILURE;
4998 if (LONE_DASH(*argv))
5006 static int builtin_true(char **argv UNUSED_PARAM)
5011 static int builtin_test(char **argv)
5018 return test_main(argc, argv - argc);
5021 static int builtin_echo(char **argv)
5028 return echo_main(argc, argv - argc);
5031 static int builtin_eval(char **argv)
5033 int rcode = EXIT_SUCCESS;
5036 char *str = expand_strvec_to_string(argv + 1);
5038 * eval "echo Hi; done" ("done" is syntax error):
5039 * "echo Hi" will not execute too.
5041 parse_and_run_string(str);
5043 rcode = G.last_return_code;
5048 static int builtin_cd(char **argv)
5051 if (argv[1] == NULL) {
5052 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5053 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5055 newdir = getenv("HOME") ? : "/";
5058 if (chdir(newdir)) {
5059 printf("cd: %s: %s\n", newdir, strerror(errno));
5060 return EXIT_FAILURE;
5063 return EXIT_SUCCESS;
5066 static int builtin_exec(char **argv)
5068 if (argv[1] == NULL)
5069 return EXIT_SUCCESS; /* bash does this */
5074 // FIXME: if exec fails, bash does NOT exit! We do...
5075 pseudo_exec_argv(&dummy, argv + 1, 0, NULL);
5080 static int builtin_exit(char **argv)
5082 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5083 //puts("exit"); /* bash does it */
5084 // TODO: warn if we have background jobs: "There are stopped jobs"
5085 // On second consecutive 'exit', exit anyway.
5086 if (argv[1] == NULL)
5087 hush_exit(G.last_return_code);
5088 /* mimic bash: exit 123abc == exit 255 + error msg */
5089 xfunc_error_retval = 255;
5090 /* bash: exit -2 == exit 254, no error msg */
5091 hush_exit(xatoi(argv[1]) & 0xff);
5094 static int builtin_export(char **argv)
5097 char *name = argv[1];
5101 // ash emits: export VAR='VAL'
5102 // bash: declare -x VAR="VAL"
5103 // (both also escape as needed (quotes, $, etc))
5108 return EXIT_SUCCESS;
5111 value = strchr(name, '=');
5113 /* They are exporting something without a =VALUE */
5114 struct variable *var;
5116 var = get_local_var(name);
5118 var->flg_export = 1;
5119 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5120 putenv(var->varstr);
5122 /* bash does not return an error when trying to export
5123 * an undefined variable. Do likewise. */
5124 return EXIT_SUCCESS;
5127 set_local_var(xstrdup(name), 1);
5128 return EXIT_SUCCESS;
5132 /* built-in 'fg' and 'bg' handler */
5133 static int builtin_fg_bg(char **argv)
5138 if (!G.interactive_fd)
5139 return EXIT_FAILURE;
5140 /* If they gave us no args, assume they want the last backgrounded task */
5142 for (pi = G.job_list; pi; pi = pi->next) {
5143 if (pi->jobid == G.last_jobid) {
5147 bb_error_msg("%s: no current job", argv[0]);
5148 return EXIT_FAILURE;
5150 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5151 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5152 return EXIT_FAILURE;
5154 for (pi = G.job_list; pi; pi = pi->next) {
5155 if (pi->jobid == jobnum) {
5159 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5160 return EXIT_FAILURE;
5162 // TODO: bash prints a string representation
5163 // of job being foregrounded (like "sleep 1 | cat")
5164 if (*argv[0] == 'f') {
5165 /* Put the job into the foreground. */
5166 tcsetpgrp(G.interactive_fd, pi->pgrp);
5169 /* Restart the processes in the job */
5170 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5171 for (i = 0; i < pi->num_cmds; i++) {
5172 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5173 pi->cmds[i].is_stopped = 0;
5175 pi->stopped_cmds = 0;
5177 i = kill(- pi->pgrp, SIGCONT);
5179 if (errno == ESRCH) {
5180 delete_finished_bg_job(pi);
5181 return EXIT_SUCCESS;
5183 bb_perror_msg("kill (SIGCONT)");
5187 if (*argv[0] == 'f') {
5189 return checkjobs_and_fg_shell(pi);
5191 return EXIT_SUCCESS;
5195 #if ENABLE_HUSH_HELP
5196 static int builtin_help(char **argv UNUSED_PARAM)
5198 const struct built_in_command *x;
5200 printf("\nBuilt-in commands:\n");
5201 printf("-------------------\n");
5202 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5203 printf("%s\t%s\n", x->cmd, x->descr);
5206 return EXIT_SUCCESS;
5211 static int builtin_jobs(char **argv UNUSED_PARAM)
5214 const char *status_string;
5216 for (job = G.job_list; job; job = job->next) {
5217 if (job->alive_cmds == job->stopped_cmds)
5218 status_string = "Stopped";
5220 status_string = "Running";
5222 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5224 return EXIT_SUCCESS;
5228 static int builtin_pwd(char **argv UNUSED_PARAM)
5231 return EXIT_SUCCESS;
5234 static int builtin_read(char **argv)
5237 const char *name = argv[1] ? argv[1] : "REPLY";
5239 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5240 return set_local_var(string, 0);
5243 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5244 * built-in 'set' handler
5246 * set [-abCefhmnuvx] [-o option] [argument...]
5247 * set [+abCefhmnuvx] [+o option] [argument...]
5248 * set -- [argument...]
5251 * Implementations shall support the options in both their hyphen and
5252 * plus-sign forms. These options can also be specified as options to sh.
5254 * Write out all variables and their values: set
5255 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5256 * Turn on the -x and -v options: set -xv
5257 * Unset all positional parameters: set --
5258 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5259 * Set the positional parameters to the expansion of x, even if x expands
5260 * with a leading '-' or '+': set -- $x
5262 * So far, we only support "set -- [argument...]" and some of the short names.
5264 static int builtin_set(char **argv)
5267 char **pp, **g_argv;
5268 char *arg = *++argv;
5272 for (e = G.top_var; e; e = e->next)
5274 return EXIT_SUCCESS;
5278 if (!strcmp(arg, "--")) {
5283 if (arg[0] == '+' || arg[0] == '-') {
5284 for (n = 1; arg[n]; ++n)
5285 if (set_mode(arg[0], arg[n]))
5291 } while ((arg = *++argv) != NULL);
5292 /* Now argv[0] is 1st argument */
5294 /* Only reset global_argv if we didn't process anything */
5296 return EXIT_SUCCESS;
5299 /* NB: G.global_argv[0] ($0) is never freed/changed */
5300 g_argv = G.global_argv;
5301 if (G.global_args_malloced) {
5307 G.global_args_malloced = 1;
5308 pp = xzalloc(sizeof(pp[0]) * 2);
5309 pp[0] = g_argv[0]; /* retain $0 */
5312 /* This realloc's G.global_argv */
5313 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
5320 return EXIT_SUCCESS;
5322 /* Nothing known, so abort */
5324 bb_error_msg("set: %s: invalid option", arg);
5325 return EXIT_FAILURE;
5328 static int builtin_shift(char **argv)
5334 if (n >= 0 && n < G.global_argc) {
5335 if (G.global_args_malloced) {
5338 free(G.global_argv[m++]);
5341 memmove(&G.global_argv[1], &G.global_argv[n+1],
5342 G.global_argc * sizeof(G.global_argv[0]));
5343 return EXIT_SUCCESS;
5345 return EXIT_FAILURE;
5348 static int builtin_source(char **argv)
5352 if (argv[1] == NULL)
5353 return EXIT_FAILURE;
5355 /* XXX search through $PATH is missing */
5356 input = fopen_for_read(argv[1]);
5358 bb_error_msg("can't open '%s'", argv[1]);
5359 return EXIT_FAILURE;
5361 close_on_exec_on(fileno(input));
5363 /* Now run the file */
5364 /* XXX argv and argc are broken; need to save old G.global_argv
5365 * (pointer only is OK!) on this stack frame,
5366 * set G.global_argv=argv+1, recurse, and restore. */
5367 parse_and_run_file(input);
5369 return G.last_return_code;
5372 static int builtin_umask(char **argv)
5375 const char *arg = argv[1];
5377 new_umask = bb_strtou(arg, NULL, 8);
5379 return EXIT_FAILURE;
5381 new_umask = umask(0);
5382 printf("%.3o\n", (unsigned) new_umask);
5385 return EXIT_SUCCESS;
5388 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
5389 static int builtin_unset(char **argv)
5396 return EXIT_SUCCESS;
5399 if (argv[1][0] == '-') {
5400 switch (argv[1][1]) {
5402 case 'f': if (ENABLE_HUSH_FUNCTIONS) { var = false; break; }
5404 bb_error_msg("unset: %s: invalid option", argv[1]);
5405 return EXIT_FAILURE;
5413 if (unset_local_var(argv[i]))
5416 #if ENABLE_HUSH_FUNCTIONS
5418 unset_local_func(argv[i]);
5424 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
5425 static int builtin_wait(char **argv)
5427 int ret = EXIT_SUCCESS;
5430 if (*++argv == NULL) {
5431 /* Don't care about wait results */
5432 /* Note 1: must wait until there are no more children */
5433 /* Note 2: must be interruptible */
5435 * $ sleep 3 & sleep 6 & wait
5440 * $ sleep 3 & sleep 6 & wait
5444 * ^C <-- after ~4 sec from keyboard
5447 sigaddset(&G.blocked_set, SIGCHLD);
5448 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5451 if (errno == ECHILD)
5453 /* Wait for SIGCHLD or any other signal of interest */
5454 /* sigtimedwait with infinite timeout: */
5455 sig = sigwaitinfo(&G.blocked_set, NULL);
5457 sig = check_and_run_traps(sig);
5458 if (sig && sig != SIGCHLD) { /* see note 2 */
5464 sigdelset(&G.blocked_set, SIGCHLD);
5465 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5469 /* This is probably buggy wrt interruptible-ness */
5471 pid_t pid = bb_strtou(*argv, NULL, 10);
5473 /* mimic bash message */
5474 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
5475 return EXIT_FAILURE;
5477 if (waitpid(pid, &status, 0) == pid) {
5478 if (WIFSIGNALED(status))
5479 ret = 128 + WTERMSIG(status);
5480 else if (WIFEXITED(status))
5481 ret = WEXITSTATUS(status);
5485 bb_perror_msg("wait %s", *argv);
5494 #if ENABLE_HUSH_LOOPS
5495 static int builtin_break(char **argv)
5497 if (G.depth_of_loop == 0) {
5498 bb_error_msg("%s: only meaningful in a loop", argv[0]);
5499 return EXIT_SUCCESS; /* bash compat */
5501 G.flag_break_continue++; /* BC_BREAK = 1 */
5502 G.depth_break_continue = 1;
5504 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
5505 if (errno || !G.depth_break_continue || argv[2]) {
5506 bb_error_msg("%s: bad arguments", argv[0]);
5507 G.flag_break_continue = BC_BREAK;
5508 G.depth_break_continue = UINT_MAX;
5511 if (G.depth_of_loop < G.depth_break_continue)
5512 G.depth_break_continue = G.depth_of_loop;
5513 return EXIT_SUCCESS;
5516 static int builtin_continue(char **argv)
5518 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
5519 return builtin_break(argv);