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>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
46 * Bash stuff (maybe optionally enable?):
47 * &> and >& redirection of stdout+stderr
49 * reserved words: [[ ]] function select
50 * substrings ${var:1:5}
53 * grep for "TODO" and fix (some of them are easy)
54 * change { and } from special chars to reserved words
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * ^Z handling (and explain it in comments for mere humans)
61 * separate job control from interactiveness
62 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
68 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
70 //#include "applet_tables.h" doesn't work
72 /* #include <dmalloc.h> */
79 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
82 #ifdef WANT_TO_TEST_NOMMU
87 # define USE_FOR_NOMMU(...) __VA_ARGS__
88 # define USE_FOR_MMU(...)
91 #if defined SINGLE_APPLET_MAIN
92 /* STANDALONE does not make sense, and won't compile */
93 #undef CONFIG_FEATURE_SH_STANDALONE
94 #undef ENABLE_FEATURE_SH_STANDALONE
95 #undef USE_FEATURE_SH_STANDALONE
96 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
97 #define ENABLE_FEATURE_SH_STANDALONE 0
98 #define USE_FEATURE_SH_STANDALONE(...)
99 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 #if !ENABLE_HUSH_INTERACTIVE
103 #undef ENABLE_FEATURE_EDITING
104 #define ENABLE_FEATURE_EDITING 0
105 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
106 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
109 /* Do we support ANY keywords? */
110 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
111 #define HAS_KEYWORDS 1
112 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
113 #define IF_HAS_NO_KEYWORDS(...)
115 #define HAS_KEYWORDS 0
116 #define IF_HAS_KEYWORDS(...)
117 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
120 /* Keep unconditionally on for now */
123 #define ENABLE_HUSH_FUNCTIONS 0
126 /* If you comment out one of these below, it will be #defined later
127 * to perform debug printfs to stderr: */
128 #define debug_printf(...) do {} while (0)
129 /* Finer-grained debug switches */
130 #define debug_printf_parse(...) do {} while (0)
131 #define debug_print_tree(a, b) do {} while (0)
132 #define debug_printf_exec(...) do {} while (0)
133 #define debug_printf_env(...) do {} while (0)
134 #define debug_printf_jobs(...) do {} while (0)
135 #define debug_printf_expand(...) do {} while (0)
136 #define debug_printf_glob(...) do {} while (0)
137 #define debug_printf_list(...) do {} while (0)
138 #define debug_printf_subst(...) do {} while (0)
139 #define debug_printf_clean(...) do {} while (0)
142 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
145 #ifndef debug_printf_parse
146 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_exec
150 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_env
154 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_jobs
158 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
164 #ifndef debug_printf_expand
165 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
166 #define DEBUG_EXPAND 1
168 #define DEBUG_EXPAND 0
171 #ifndef debug_printf_glob
172 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
178 #ifndef debug_printf_list
179 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_subst
183 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_clean
187 /* broken, of course, but OK for testing */
188 static const char *indenter(int i)
190 static const char blanks[] ALIGN1 =
192 return &blanks[sizeof(blanks) - i - 1];
194 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
195 #define DEBUG_CLEAN 1
197 #define DEBUG_CLEAN 0
201 static void debug_print_strings(const char *prefix, char **vv)
203 fprintf(stderr, "%s:\n", prefix);
205 fprintf(stderr, " '%s'\n", *vv++);
208 #define debug_print_strings(prefix, vv) ((void)0)
212 * Leak hunting. Use hush_leaktool.sh for post-processing.
214 #ifdef FOR_HUSH_LEAKTOOL
215 static void *xxmalloc(int lineno, size_t size)
217 void *ptr = xmalloc((size + 0xff) & ~0xff);
218 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
221 static void *xxrealloc(int lineno, void *ptr, size_t size)
223 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
224 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
227 static char *xxstrdup(int lineno, const char *str)
229 char *ptr = xstrdup(str);
230 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
233 static void xxfree(void *ptr)
235 fdprintf(2, "free %p\n", ptr);
238 #define xmalloc(s) xxmalloc(__LINE__, s)
239 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
240 #define xstrdup(s) xxstrdup(__LINE__, s)
241 #define free(p) xxfree(p)
245 #define ERR_PTR ((void*)(long)1)
247 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
249 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
251 #define SPECIAL_VAR_SYMBOL 3
253 /* The descrip member of this structure is only used to make
254 * debugging output pretty */
255 static const struct {
257 signed char default_fd;
261 { O_RDONLY, 0, "<" },
262 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
263 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
264 { O_RDONLY, 0, "<<" },
265 { O_CREAT|O_RDWR, 1, "<>" },
266 /* Should not be needed. Bogus default_fd helps in debugging */
267 /* { O_RDONLY, 77, "<<" }, */
270 typedef enum reserved_style {
279 #if ENABLE_HUSH_LOOPS
286 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
291 /* two pseudo-keywords support contrived "case" syntax: */
292 RES_MATCH , /* "word)" */
293 RES_CASEI , /* "this command is inside CASE" */
300 typedef struct o_string {
302 int length; /* position where data is appended */
304 /* Protect newly added chars against globbing
305 * (by prepending \ to *, ?, [, \) */
309 smallint has_empty_slot;
310 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
313 MAYBE_ASSIGNMENT = 0,
314 DEFINITELY_ASSIGNMENT = 1,
316 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
318 /* Used for initialization: o_string foo = NULL_O_STRING; */
319 #define NULL_O_STRING { NULL }
321 /* I can almost use ordinary FILE*. Is open_memstream() universally
322 * available? Where is it documented? */
323 typedef struct in_str {
325 /* eof_flag=1: last char in ->p is really an EOF */
326 char eof_flag; /* meaningless if ->p == NULL */
328 #if ENABLE_HUSH_INTERACTIVE
330 smallint promptmode; /* 0: PS1, 1: PS2 */
333 int (*get) (struct in_str *);
334 int (*peek) (struct in_str *);
336 #define i_getch(input) ((input)->get(input))
337 #define i_peek(input) ((input)->peek(input))
339 struct redir_struct {
340 struct redir_struct *next;
341 char *rd_filename; /* filename */
342 int rd_fd; /* file descriptor being redirected */
343 int rd_dup; /* -1, or file descriptor being duplicated */
344 smallint rd_type; /* (enum redir_type) */
345 /* note: for heredocs, rd_filename contains heredoc delimiter,
346 * and subsequently heredoc itself; and rd_dup is
347 * "do we need to trim leading tabs?" bool flag
350 typedef enum redir_type {
351 REDIRECT_INVALID = 0,
353 REDIRECT_OVERWRITE = 2,
355 REDIRECT_HEREDOC = 4,
357 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
362 pid_t pid; /* 0 if exited */
363 int assignment_cnt; /* how many argv[i] are assignments? */
364 smallint is_stopped; /* is the command currently running? */
365 smallint grp_type; /* GRP_xxx */
366 struct pipe *group; /* if non-NULL, this "command" is { list },
367 * ( list ), or a compound statement */
369 char *group_as_string;
371 char **argv; /* command name and arguments */
372 struct redir_struct *redirects; /* I/O redirections */
374 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
375 * and on execution these are substituted with their values.
376 * Substitution can make _several_ words out of one argv[n]!
377 * Example: argv[0]=='.^C*^C.' here: echo .$*.
378 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
381 #define GRP_SUBSHELL 1
382 #if ENABLE_HUSH_FUNCTIONS
383 #define GRP_FUNCTION 2
388 int num_cmds; /* total number of commands in job */
389 int alive_cmds; /* number of commands running (not exited) */
390 int stopped_cmds; /* number of commands alive, but stopped */
392 int jobid; /* job number */
393 pid_t pgrp; /* process group ID for the job */
394 char *cmdtext; /* name of job */
396 struct command *cmds; /* array of commands in pipe */
397 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
398 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
399 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
401 typedef enum pipe_style {
408 /* This holds pointers to the various results of parsing */
409 struct parse_context {
410 /* linked list of pipes */
411 struct pipe *list_head;
412 /* last pipe (being constructed right now) */
414 /* last command in pipe (being constructed right now) */
415 struct command *command;
416 /* last redirect in command->redirects list */
417 struct redir_struct *pending_redirect;
423 smallint ctx_inverted; /* "! cmd | cmd" */
425 smallint ctx_dsemicolon; /* ";;" seen */
427 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
429 /* group we are enclosed in:
430 * example: "if pipe1; pipe2; then pipe3; fi"
431 * when we see "if" or "then", we malloc and copy current context,
432 * and make ->stack point to it. then we parse pipeN.
433 * when closing "then" / fi" / whatever is found,
434 * we move list_head into ->stack->command->group,
435 * copy ->stack into current context, and delete ->stack.
436 * (parsing of { list } and ( list ) doesn't use this method)
438 struct parse_context *stack;
442 /* On program start, environ points to initial environment.
443 * putenv adds new pointers into it, unsetenv removes them.
444 * Neither of these (de)allocates the strings.
445 * setenv allocates new strings in malloc space and does putenv,
446 * and thus setenv is unusable (leaky) for shell's purposes */
447 #define setenv(...) setenv_is_leaky_dont_use()
449 struct variable *next;
450 char *varstr; /* points to "name=" portion */
451 int max_len; /* if > 0, name is part of initial env; else name is malloced */
452 smallint flg_export; /* putenv should be done on this var */
453 smallint flg_read_only;
462 /* "Globals" within this file */
463 /* Sorted roughly by size (smaller offsets == smaller code) */
465 #if ENABLE_HUSH_INTERACTIVE
466 /* 'interactive_fd' is a fd# open to ctty, if we have one
467 * _AND_ if we decided to act interactively */
471 #define G_interactive_fd (G.interactive_fd)
473 #define G_interactive_fd 0
475 #if ENABLE_FEATURE_EDITING
476 line_input_t *line_input_state;
482 pid_t saved_tty_pgrp;
484 struct pipe *job_list;
485 struct pipe *toplevel_list;
486 //// smallint ctrl_z_flag;
488 smallint flag_SIGINT;
489 #if ENABLE_HUSH_LOOPS
490 smallint flag_break_continue;
493 /* These four support $?, $#, and $1 */
494 smalluint last_exitcode;
495 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
496 smalluint global_args_malloced;
497 /* how many non-NULL argv's we have. NB: $# + 1 */
501 char *argv0_for_re_execing;
502 char **argv_from_re_execing;
504 #if ENABLE_HUSH_LOOPS
505 unsigned depth_break_continue;
506 unsigned depth_of_loop;
510 struct variable *top_var; /* = &G.shell_ver (set in main()) */
511 struct variable shell_ver;
512 /* Signal and trap handling */
513 // unsigned count_SIGCHLD;
514 // unsigned handled_SIGCHLD;
515 /* which signals have non-DFL handler (even with no traps set)? */
516 unsigned non_DFL_mask;
517 char **traps; /* char *traps[NSIG] */
518 sigset_t blocked_set;
519 sigset_t inherited_set;
520 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
521 #if ENABLE_FEATURE_SH_STANDALONE
522 struct nofork_save_area nofork_save;
525 sigjmp_buf toplevel_jb;
528 #define G (*ptr_to_globals)
529 /* Not #defining name to G.name - this quickly gets unwieldy
530 * (too many defines). Also, I actually prefer to see when a variable
531 * is global, thus "G." prefix is a useful hint */
532 #define INIT_G() do { \
533 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
537 /* Function prototypes for builtins */
538 static int builtin_cd(char **argv);
539 static int builtin_echo(char **argv);
540 static int builtin_eval(char **argv);
541 static int builtin_exec(char **argv);
542 static int builtin_exit(char **argv);
543 static int builtin_export(char **argv);
545 static int builtin_fg_bg(char **argv);
546 static int builtin_jobs(char **argv);
549 static int builtin_help(char **argv);
551 static int builtin_pwd(char **argv);
552 static int builtin_read(char **argv);
553 static int builtin_test(char **argv);
554 static int builtin_trap(char **argv);
555 static int builtin_true(char **argv);
556 static int builtin_set(char **argv);
557 static int builtin_shift(char **argv);
558 static int builtin_source(char **argv);
559 static int builtin_umask(char **argv);
560 static int builtin_unset(char **argv);
561 static int builtin_wait(char **argv);
562 #if ENABLE_HUSH_LOOPS
563 static int builtin_break(char **argv);
564 static int builtin_continue(char **argv);
567 /* Table of built-in functions. They can be forked or not, depending on
568 * context: within pipes, they fork. As simple commands, they do not.
569 * When used in non-forking context, they can change global variables
570 * in the parent shell process. If forked, of course they cannot.
571 * For example, 'unset foo | whatever' will parse and run, but foo will
572 * still be set at the end. */
573 struct built_in_command {
575 int (*function)(char **argv);
578 #define BLTIN(cmd, func, help) { cmd, func, help }
580 #define BLTIN(cmd, func, help) { cmd, func }
584 /* For now, echo and test are unconditionally enabled.
585 * Maybe make it configurable? */
586 static const struct built_in_command bltins[] = {
587 BLTIN("." , builtin_source , "Run commands in a file"),
588 BLTIN(":" , builtin_true , "No-op"),
589 BLTIN("[" , builtin_test , "Test condition"),
591 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
593 #if ENABLE_HUSH_LOOPS
594 BLTIN("break" , builtin_break , "Exit from a loop"),
596 BLTIN("cd" , builtin_cd , "Change directory"),
597 #if ENABLE_HUSH_LOOPS
598 BLTIN("continue", builtin_continue, "Start new loop iteration"),
600 BLTIN("echo" , builtin_echo , "Write to stdout"),
601 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
602 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
603 BLTIN("exit" , builtin_exit , "Exit"),
604 BLTIN("export" , builtin_export , "Set environment variable"),
606 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
609 BLTIN("help" , builtin_help , "List shell built-in commands"),
612 BLTIN("jobs" , builtin_jobs , "List active jobs"),
614 BLTIN("pwd" , builtin_pwd , "Print current directory"),
615 BLTIN("read" , builtin_read , "Input environment variable"),
616 // BLTIN("return" , builtin_return , "Return from a function"),
617 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
618 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
619 BLTIN("test" , builtin_test , "Test condition"),
620 BLTIN("trap" , builtin_trap , "Trap signals"),
621 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
622 BLTIN("umask" , builtin_umask , "Set file creation mask"),
623 BLTIN("unset" , builtin_unset , "Unset environment variable"),
624 BLTIN("wait" , builtin_wait , "Wait for process"),
628 static void maybe_die(const char *notice, const char *msg)
630 /* Was using fancy stuff:
631 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
632 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
633 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
634 #if ENABLE_HUSH_INTERACTIVE
635 if (G_interactive_fd)
638 fp(msg ? "%s: %s" : notice, notice, msg);
641 #define syntax(msg) maybe_die("syntax error", msg);
643 /* Debug -- trick gcc to expand __LINE__ and convert to string */
644 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
645 #define _syntax(msg, line) __syntax(msg, line)
646 #define syntax(msg) _syntax(msg, __LINE__)
650 static int glob_needed(const char *s)
655 if (*s == '*' || *s == '[' || *s == '?')
662 static int is_assignment(const char *s)
664 if (!s || !(isalpha(*s) || *s == '_'))
667 while (isalnum(*s) || *s == '_')
672 /* Replace each \x with x in place, return ptr past NUL. */
673 static char *unbackslash(char *src)
679 if ((*dst++ = *src++) == '\0')
685 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
706 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
707 v[count1 + count2] = NULL;
710 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
714 static char **add_string_to_strings(char **strings, char *add)
719 return add_strings_to_strings(strings, v, /*dup:*/ 0);
722 static void putenv_all(char **strings)
727 debug_printf_env("putenv '%s'\n", *strings);
732 static char **putenv_all_and_save_old(char **strings)
742 eq = strchr(*strings, '=');
745 v = getenv(*strings);
748 /* v points to VAL in VAR=VAL, go back to VAR */
749 v -= (eq - *strings) + 1;
750 old = add_string_to_strings(old, v);
759 static void free_strings_and_unsetenv(char **strings, int unset)
769 debug_printf_env("unsetenv '%s'\n", *v);
777 static void free_strings(char **strings)
779 free_strings_and_unsetenv(strings, 0);
783 /* Basic theory of signal handling in shell
784 * ========================================
785 * This does not describe what hush does, rather, it is current understanding
786 * what it _should_ do. If it doesn't, it's a bug.
787 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
789 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
790 * is finished or backgrounded. It is the same in interactive and
791 * non-interactive shells, and is the same regardless of whether
792 * a user trap handler is installed or a shell special one is in effect.
793 * ^C or ^Z from keyboard seem to execute "at once" because it usually
794 * backgrounds (i.e. stops) or kills all members of currently running
797 * Wait builtin in interruptible by signals for which user trap is set
798 * or by SIGINT in interactive shell.
800 * Trap handlers will execute even within trap handlers. (right?)
802 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
804 * If job control is off, backgrounded commands ("cmd &")
805 * have SIGINT, SIGQUIT set to SIG_IGN.
807 * Commands run in command substitution ("`cmd`")
808 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
810 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
811 * by the shell from its parent.
813 * Siganls which differ from SIG_DFL action
814 * (note: child (i.e., [v]forked) shell is not an interactive shell):
817 * SIGTERM (interactive): ignore
818 * SIGHUP (interactive):
819 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
820 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
821 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
822 * that all pipe members are stopped) (right?)
823 * SIGINT (interactive): wait for last pipe, ignore the rest
824 * of the command line, show prompt. NB: ^C does not send SIGINT
825 * to interactive shell while shell is waiting for a pipe,
826 * since shell is bg'ed (is not in foreground process group).
827 * (check/expand this)
828 * Example 1: this waits 5 sec, but does not execute ls:
829 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
830 * Example 2: this does not wait and does not execute ls:
831 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
832 * Example 3: this does not wait 5 sec, but executes ls:
833 * "sleep 5; ls -l" + press ^C
835 * (What happens to signals which are IGN on shell start?)
836 * (What happens with signal mask on shell start?)
838 * Implementation in hush
839 * ======================
840 * We use in-kernel pending signal mask to determine which signals were sent.
841 * We block all signals which we don't want to take action immediately,
842 * i.e. we block all signals which need to have special handling as described
843 * above, and all signals which have traps set.
844 * After each pipe execution, we extract any pending signals via sigtimedwait()
847 * unsigned non_DFL_mask: a mask of such "special" signals
848 * sigset_t blocked_set: current blocked signal set
851 * clear bit in blocked_set unless it is also in non_DFL_mask
852 * "trap 'cmd' SIGxxx":
853 * set bit in blocked_set (even if 'cmd' is '')
854 * after [v]fork, if we plan to be a shell:
855 * nothing for {} child shell (say, "true | { true; true; } | true")
856 * unset all traps if () shell. [TODO]
857 * after [v]fork, if we plan to exec:
858 * POSIX says pending signal mask is cleared in child - no need to clear it.
859 * Restore blocked signal set to one inherited by shell just prior to exec.
861 * Note: as a result, we do not use signal handlers much. The only uses
862 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
863 * and to restore tty pgrp on signal-induced exit.
866 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
868 // G.count_SIGCHLD++;
871 static int check_and_run_traps(int sig)
873 static const struct timespec zero_timespec = { 0, 0 };
874 smalluint save_rcode;
880 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
885 if (G.traps && G.traps[sig]) {
886 if (G.traps[sig][0]) {
887 /* We have user-defined handler */
888 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
889 save_rcode = G.last_exitcode;
892 G.last_exitcode = save_rcode;
893 } /* else: "" trap, ignoring signal */
896 /* not a trap: special action */
899 // G.count_SIGCHLD++;
908 default: /* ignored: */
909 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
917 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
918 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
919 /* After [v]fork, in parent: do not restore tty pgrp on xfunc death */
920 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
922 /* Restores tty foreground process group, and exits.
923 * May be called as signal handler for fatal signal
924 * (will faithfully resend signal to itself, producing correct exit state)
925 * or called directly with -EXITCODE.
926 * We also call it if xfunc is exiting. */
927 static void sigexit(int sig) NORETURN;
928 static void sigexit(int sig)
930 /* Disable all signals: job control, SIGPIPE, etc. */
931 sigprocmask_allsigs(SIG_BLOCK);
933 /* Careful: we can end up here after [v]fork. Do not restore
934 * tty pgrp then, only top-level shell process does that */
935 if (G_interactive_fd && getpid() == G.root_pid)
936 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
938 /* Not a signal, just exit */
942 kill_myself_with_sig(sig); /* does not return */
946 #define disable_restore_tty_pgrp_on_exit() ((void)0)
947 #define enable_restore_tty_pgrp_on_exit() ((void)0)
951 /* Restores tty foreground process group, and exits. */
952 static void hush_exit(int exitcode) NORETURN;
953 static void hush_exit(int exitcode)
955 if (G.traps && G.traps[0] && G.traps[0][0]) {
956 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
957 //TODO: do we need to prevent recursion?
963 fflush(NULL); /* flush all streams */
964 sigexit(- (exitcode & 0xff));
971 static const char *set_cwd(void)
973 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
974 * we must not try to free(bb_msg_unknown) */
975 if (G.cwd == bb_msg_unknown)
977 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
979 G.cwd = bb_msg_unknown;
984 /* Get/check local shell variables */
985 static struct variable *get_local_var(const char *name)
987 struct variable *cur;
993 for (cur = G.top_var; cur; cur = cur->next) {
994 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1000 static const char *get_local_var_value(const char *src)
1002 struct variable *var = get_local_var(src);
1004 return strchr(var->varstr, '=') + 1;
1008 /* str holds "NAME=VAL" and is expected to be malloced.
1009 * We take ownership of it.
1013 * -1: if NAME is set, leave export status alone
1014 * if NAME is not set, do not export
1015 * flg_read_only is set only when we handle -R var=val
1018 #define set_local_var(str, flg_export, flg_read_only) \
1019 set_local_var(str, flg_export)
1021 static int set_local_var(char *str, int flg_export, int flg_read_only)
1023 struct variable *cur;
1027 value = strchr(str, '=');
1028 if (!value) { /* not expected to ever happen? */
1033 name_len = value - str + 1; /* including '=' */
1034 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1036 if (strncmp(cur->varstr, str, name_len) != 0) {
1038 /* Bail out. Note that now cur points
1039 * to last var in linked list */
1045 /* We found an existing var with this name */
1047 if (cur->flg_read_only) {
1051 bb_error_msg("%s: readonly variable", str);
1055 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1056 unsetenv(str); /* just in case */
1058 if (strcmp(cur->varstr, str) == 0) {
1063 if (cur->max_len >= strlen(str)) {
1064 /* This one is from startup env, reuse space */
1065 strcpy(cur->varstr, str);
1068 /* max_len == 0 signifies "malloced" var, which we can
1069 * (and has to) free */
1073 goto set_str_and_exp;
1076 /* Not found - create next variable struct */
1077 cur->next = xzalloc(sizeof(*cur));
1083 cur->flg_read_only = flg_read_only;
1086 if (flg_export == 1)
1087 cur->flg_export = 1;
1088 if (cur->flg_export) {
1089 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1090 return putenv(cur->varstr);
1095 static int unset_local_var(const char *name)
1097 struct variable *cur;
1098 struct variable *prev = prev; /* for gcc */
1102 return EXIT_SUCCESS;
1103 name_len = strlen(name);
1106 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1107 if (cur->flg_read_only) {
1108 bb_error_msg("%s: readonly variable", name);
1109 return EXIT_FAILURE;
1111 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1112 * is ro, and we cannot reach this code on the 1st pass */
1113 prev->next = cur->next;
1114 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1115 bb_unsetenv(cur->varstr);
1119 return EXIT_SUCCESS;
1124 return EXIT_SUCCESS;
1127 #if ENABLE_SH_MATH_SUPPORT
1128 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1129 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1130 static char *endofname(const char *name)
1138 if (!is_in_name(*p))
1144 static void arith_set_local_var(const char *name, const char *val, int flags)
1146 /* arith code doesnt malloc space, so do it for it */
1147 char *var = xasprintf("%s=%s", name, val);
1148 set_local_var(var, flags, 0);
1156 static int static_get(struct in_str *i)
1165 static int static_peek(struct in_str *i)
1170 #if ENABLE_HUSH_INTERACTIVE
1172 static void cmdedit_set_initial_prompt(void)
1174 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1175 G.PS1 = getenv("PS1");
1182 static const char* setup_prompt_string(int promptmode)
1184 const char *prompt_str;
1185 debug_printf("setup_prompt_string %d ", promptmode);
1186 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1187 /* Set up the prompt */
1188 if (promptmode == 0) { /* PS1 */
1190 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1195 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1196 debug_printf("result '%s'\n", prompt_str);
1200 static void get_user_input(struct in_str *i)
1203 const char *prompt_str;
1205 prompt_str = setup_prompt_string(i->promptmode);
1206 #if ENABLE_FEATURE_EDITING
1207 /* Enable command line editing only while a command line
1208 * is actually being read */
1211 /* buglet: SIGINT will not make new prompt to appear _at once_,
1212 * only after <Enter>. (^C will work) */
1213 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1214 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1215 check_and_run_traps(0);
1216 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1217 i->eof_flag = (r < 0);
1218 if (i->eof_flag) { /* EOF/error detected */
1219 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1220 G.user_input_buf[1] = '\0';
1225 fputs(prompt_str, stdout);
1227 G.user_input_buf[0] = r = fgetc(i->file);
1228 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1229 //do we need check_and_run_traps(0)? (maybe only if stdin)
1230 } while (G.flag_SIGINT);
1231 i->eof_flag = (r == EOF);
1233 i->p = G.user_input_buf;
1236 #endif /* INTERACTIVE */
1238 /* This is the magic location that prints prompts
1239 * and gets data back from the user */
1240 static int file_get(struct in_str *i)
1244 /* If there is data waiting, eat it up */
1245 if (i->p && *i->p) {
1246 #if ENABLE_HUSH_INTERACTIVE
1250 if (i->eof_flag && !*i->p)
1252 /* note: ch is never NUL */
1254 /* need to double check i->file because we might be doing something
1255 * more complicated by now, like sourcing or substituting. */
1256 #if ENABLE_HUSH_INTERACTIVE
1257 if (G_interactive_fd && i->promptme && i->file == stdin) {
1260 } while (!*i->p); /* need non-empty line */
1261 i->promptmode = 1; /* PS2 */
1266 do ch = fgetc(i->file); while (ch == '\0');
1268 debug_printf("file_get: got '%c' %d\n", ch, ch);
1269 #if ENABLE_HUSH_INTERACTIVE
1276 /* All callers guarantee this routine will never
1277 * be used right after a newline, so prompting is not needed.
1279 static int file_peek(struct in_str *i)
1282 if (i->p && *i->p) {
1283 if (i->eof_flag && !i->p[1])
1286 /* note: ch is never NUL */
1288 do ch = fgetc(i->file); while (ch == '\0');
1289 i->eof_flag = (ch == EOF);
1290 i->peek_buf[0] = ch;
1291 i->peek_buf[1] = '\0';
1293 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1297 static void setup_file_in_str(struct in_str *i, FILE *f)
1299 i->peek = file_peek;
1301 #if ENABLE_HUSH_INTERACTIVE
1303 i->promptmode = 0; /* PS1 */
1309 static void setup_string_in_str(struct in_str *i, const char *s)
1311 i->peek = static_peek;
1312 i->get = static_get;
1313 #if ENABLE_HUSH_INTERACTIVE
1315 i->promptmode = 0; /* PS1 */
1325 #define B_CHUNK (32 * sizeof(char*))
1327 static void o_reset(o_string *o)
1335 static void o_free(o_string *o)
1338 memset(o, 0, sizeof(*o));
1341 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1346 static void o_grow_by(o_string *o, int len)
1348 if (o->length + len > o->maxlen) {
1349 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1350 o->data = xrealloc(o->data, 1 + o->maxlen);
1354 static void o_addchr(o_string *o, int ch)
1356 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1358 o->data[o->length] = ch;
1360 o->data[o->length] = '\0';
1363 static void o_addblock(o_string *o, const char *str, int len)
1366 memcpy(&o->data[o->length], str, len);
1368 o->data[o->length] = '\0';
1372 static void o_addstr(o_string *o, const char *str)
1374 o_addblock(o, str, strlen(str));
1376 static void nommu_addchr(o_string *o, int ch)
1382 #define nommu_addchr(o, str) ((void)0)
1385 static void o_addstr_with_NUL(o_string *o, const char *str)
1387 o_addblock(o, str, strlen(str) + 1);
1390 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1395 && (*str != '*' && *str != '?' && *str != '[')
1403 /* My analysis of quoting semantics tells me that state information
1404 * is associated with a destination, not a source.
1406 static void o_addqchr(o_string *o, int ch)
1409 char *found = strchr("*?[\\", ch);
1414 o->data[o->length] = '\\';
1417 o->data[o->length] = ch;
1419 o->data[o->length] = '\0';
1422 static void o_addQchr(o_string *o, int ch)
1425 if (o->o_escape && strchr("*?[\\", ch)) {
1427 o->data[o->length] = '\\';
1431 o->data[o->length] = ch;
1433 o->data[o->length] = '\0';
1436 static void o_addQstr(o_string *o, const char *str, int len)
1439 o_addblock(o, str, len);
1445 int ordinary_cnt = strcspn(str, "*?[\\");
1446 if (ordinary_cnt > len) /* paranoia */
1448 o_addblock(o, str, ordinary_cnt);
1449 if (ordinary_cnt == len)
1451 str += ordinary_cnt;
1452 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1456 if (ch) { /* it is necessarily one of "*?[\\" */
1458 o->data[o->length] = '\\';
1462 o->data[o->length] = ch;
1464 o->data[o->length] = '\0';
1468 /* A special kind of o_string for $VAR and `cmd` expansion.
1469 * It contains char* list[] at the beginning, which is grown in 16 element
1470 * increments. Actual string data starts at the next multiple of 16 * (char*).
1471 * list[i] contains an INDEX (int!) into this string data.
1472 * It means that if list[] needs to grow, data needs to be moved higher up
1473 * but list[i]'s need not be modified.
1474 * NB: remembering how many list[i]'s you have there is crucial.
1475 * o_finalize_list() operation post-processes this structure - calculates
1476 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1478 #if DEBUG_EXPAND || DEBUG_GLOB
1479 static void debug_print_list(const char *prefix, o_string *o, int n)
1481 char **list = (char**)o->data;
1482 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1484 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1485 prefix, list, n, string_start, o->length, o->maxlen);
1487 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1488 o->data + (int)list[i] + string_start,
1489 o->data + (int)list[i] + string_start);
1493 const char *p = o->data + (int)list[n - 1] + string_start;
1494 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1498 #define debug_print_list(prefix, o, n) ((void)0)
1501 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1502 * in list[n] so that it points past last stored byte so far.
1503 * It returns n+1. */
1504 static int o_save_ptr_helper(o_string *o, int n)
1506 char **list = (char**)o->data;
1510 if (!o->has_empty_slot) {
1511 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1512 string_len = o->length - string_start;
1513 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1514 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1515 /* list[n] points to string_start, make space for 16 more pointers */
1516 o->maxlen += 0x10 * sizeof(list[0]);
1517 o->data = xrealloc(o->data, o->maxlen + 1);
1518 list = (char**)o->data;
1519 memmove(list + n + 0x10, list + n, string_len);
1520 o->length += 0x10 * sizeof(list[0]);
1522 debug_printf_list("list[%d]=%d string_start=%d\n",
1523 n, string_len, string_start);
1526 /* We have empty slot at list[n], reuse without growth */
1527 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1528 string_len = o->length - string_start;
1529 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1530 n, string_len, string_start);
1531 o->has_empty_slot = 0;
1533 list[n] = (char*)(ptrdiff_t)string_len;
1537 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1538 static int o_get_last_ptr(o_string *o, int n)
1540 char **list = (char**)o->data;
1541 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1543 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1546 /* o_glob performs globbing on last list[], saving each result
1547 * as a new list[]. */
1548 static int o_glob(o_string *o, int n)
1554 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1556 return o_save_ptr_helper(o, n);
1557 pattern = o->data + o_get_last_ptr(o, n);
1558 debug_printf_glob("glob pattern '%s'\n", pattern);
1559 if (!glob_needed(pattern)) {
1561 o->length = unbackslash(pattern) - o->data;
1562 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1563 return o_save_ptr_helper(o, n);
1566 memset(&globdata, 0, sizeof(globdata));
1567 gr = glob(pattern, 0, NULL, &globdata);
1568 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1569 if (gr == GLOB_NOSPACE)
1570 bb_error_msg_and_die("out of memory during glob");
1571 if (gr == GLOB_NOMATCH) {
1572 globfree(&globdata);
1575 if (gr != 0) { /* GLOB_ABORTED ? */
1576 //TODO: testcase for bad glob pattern behavior
1577 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1579 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1580 char **argv = globdata.gl_pathv;
1581 o->length = pattern - o->data; /* "forget" pattern */
1583 o_addstr_with_NUL(o, *argv);
1584 n = o_save_ptr_helper(o, n);
1590 globfree(&globdata);
1592 debug_print_list("o_glob returning", o, n);
1596 /* If o->o_glob == 1, glob the string so far remembered.
1597 * Otherwise, just finish current list[] and start new */
1598 static int o_save_ptr(o_string *o, int n)
1600 if (o->o_glob) { /* if globbing is requested */
1601 /* If o->has_empty_slot, list[n] was already globbed
1602 * (if it was requested back then when it was filled)
1603 * so don't do that again! */
1604 if (!o->has_empty_slot)
1605 return o_glob(o, n); /* o_save_ptr_helper is inside */
1607 return o_save_ptr_helper(o, n);
1610 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1611 static char **o_finalize_list(o_string *o, int n)
1616 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1618 debug_print_list("finalized", o, n);
1619 debug_printf_expand("finalized n:%d\n", n);
1620 list = (char**)o->data;
1621 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1625 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1631 /* Expansion can recurse */
1632 #if ENABLE_HUSH_TICK
1633 static int process_command_subs(o_string *dest, const char *s);
1635 static char *expand_string_to_string(const char *str);
1637 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1638 parse_stream_dquoted(dest, input, dquote_end)
1640 static int parse_stream_dquoted(o_string *as_string,
1642 struct in_str *input,
1645 /* expand_strvec_to_strvec() takes a list of strings, expands
1646 * all variable references within and returns a pointer to
1647 * a list of expanded strings, possibly with larger number
1648 * of strings. (Think VAR="a b"; echo $VAR).
1649 * This new list is allocated as a single malloc block.
1650 * NULL-terminated list of char* pointers is at the beginning of it,
1651 * followed by strings themself.
1652 * Caller can deallocate entire list by single free(list). */
1654 /* Store given string, finalizing the word and starting new one whenever
1655 * we encounter IFS char(s). This is used for expanding variable values.
1656 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1657 static int expand_on_ifs(o_string *output, int n, const char *str)
1660 int word_len = strcspn(str, G.ifs);
1662 if (output->o_escape || !output->o_glob)
1663 o_addQstr(output, str, word_len);
1664 else /* protect backslashes against globbing up :) */
1665 o_addblock_duplicate_backslash(output, str, word_len);
1668 if (!*str) /* EOL - do not finalize word */
1670 o_addchr(output, '\0');
1671 debug_print_list("expand_on_ifs", output, n);
1672 n = o_save_ptr(output, n);
1673 str += strspn(str, G.ifs); /* skip ifs chars */
1675 debug_print_list("expand_on_ifs[1]", output, n);
1679 /* Expand all variable references in given string, adding words to list[]
1680 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1681 * to be filled). This routine is extremely tricky: has to deal with
1682 * variables/parameters with whitespace, $* and $@, and constructs like
1683 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1684 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1686 /* or_mask is either 0 (normal case) or 0x80
1687 * (expansion of right-hand side of assignment == 1-element expand.
1688 * It will also do no globbing, and thus we must not backslash-quote!) */
1690 char first_ch, ored_ch;
1698 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1699 debug_print_list("expand_vars_to_list", output, n);
1700 n = o_save_ptr(output, n);
1701 debug_print_list("expand_vars_to_list[0]", output, n);
1703 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1704 #if ENABLE_HUSH_TICK
1705 o_string subst_result = NULL_O_STRING;
1707 #if ENABLE_SH_MATH_SUPPORT
1708 char arith_buf[sizeof(arith_t)*3 + 2];
1710 o_addblock(output, arg, p - arg);
1711 debug_print_list("expand_vars_to_list[1]", output, n);
1713 p = strchr(p, SPECIAL_VAR_SYMBOL);
1715 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1716 /* "$@" is special. Even if quoted, it can still
1717 * expand to nothing (not even an empty string) */
1718 if ((first_ch & 0x7f) != '@')
1719 ored_ch |= first_ch;
1722 switch (first_ch & 0x7f) {
1723 /* Highest bit in first_ch indicates that var is double-quoted */
1725 val = utoa(G.root_pid);
1727 case '!': /* bg pid */
1728 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1730 case '?': /* exitcode */
1731 val = utoa(G.last_exitcode);
1733 case '#': /* argc */
1734 if (arg[1] != SPECIAL_VAR_SYMBOL)
1735 /* actually, it's a ${#var} */
1737 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1742 if (!G.global_argv[i])
1744 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1745 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1746 smallint sv = output->o_escape;
1747 /* unquoted var's contents should be globbed, so don't escape */
1748 output->o_escape = 0;
1749 while (G.global_argv[i]) {
1750 n = expand_on_ifs(output, n, G.global_argv[i]);
1751 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1752 if (G.global_argv[i++][0] && G.global_argv[i]) {
1753 /* this argv[] is not empty and not last:
1754 * put terminating NUL, start new word */
1755 o_addchr(output, '\0');
1756 debug_print_list("expand_vars_to_list[2]", output, n);
1757 n = o_save_ptr(output, n);
1758 debug_print_list("expand_vars_to_list[3]", output, n);
1761 output->o_escape = sv;
1763 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1764 * and in this case should treat it like '$*' - see 'else...' below */
1765 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1767 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1768 if (++i >= G.global_argc)
1770 o_addchr(output, '\0');
1771 debug_print_list("expand_vars_to_list[4]", output, n);
1772 n = o_save_ptr(output, n);
1774 } else { /* quoted $*: add as one word */
1776 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1777 if (!G.global_argv[++i])
1780 o_addchr(output, G.ifs[0]);
1784 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1785 /* "Empty variable", used to make "" etc to not disappear */
1789 #if ENABLE_HUSH_TICK
1790 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1793 //TODO: can we just stuff it into "output" directly?
1794 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1795 process_command_subs(&subst_result, arg);
1796 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1797 val = subst_result.data;
1800 #if ENABLE_SH_MATH_SUPPORT
1801 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1802 arith_eval_hooks_t hooks;
1807 arg++; /* skip '+' */
1808 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1809 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1811 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1813 if (strchr(arg, '$') != NULL
1814 #if ENABLE_HUSH_TICK
1815 || strchr(arg, '`') != NULL
1818 /* We need to expand. Example:
1819 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1821 struct in_str input;
1822 o_string dest = NULL_O_STRING;
1824 setup_string_in_str(&input, arg);
1825 parse_stream_dquoted(NULL, &dest, &input, EOF);
1826 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1827 exp_str = expand_string_to_string(dest.data);
1828 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1829 o_free_unsafe(&dest);
1831 hooks.lookupvar = get_local_var_value;
1832 hooks.setvar = arith_set_local_var;
1833 hooks.endofname = endofname;
1834 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1839 case -3: maybe_die("arith", "exponent less than 0"); break;
1840 case -2: maybe_die("arith", "divide by zero"); break;
1841 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1842 default: maybe_die("arith", "syntax error"); break;
1845 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1846 sprintf(arith_buf, arith_t_fmt, res);
1851 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1853 bool exp_len = false;
1854 bool exp_null = false;
1856 char exp_save = exp_save; /* for compiler */
1857 char exp_op = exp_op; /* for compiler */
1858 char *exp_word = exp_word; /* for compiler */
1862 arg[0] = first_ch & 0x7f;
1864 /* prepare for expansions */
1865 if (var[0] == '#') {
1866 /* handle length expansion ${#var} */
1870 /* maybe handle parameter expansion */
1871 exp_off = strcspn(var, ":-=+?%#");
1875 exp_save = var[exp_off];
1876 exp_null = exp_save == ':';
1877 exp_word = var + exp_off;
1878 if (exp_null) ++exp_word;
1879 exp_op = *exp_word++;
1880 var[exp_off] = '\0';
1884 /* lookup the variable in question */
1885 if (isdigit(var[0])) {
1886 /* handle_dollar() should have vetted var for us */
1888 if (i < G.global_argc)
1889 val = G.global_argv[i];
1890 /* else val remains NULL: $N with too big N */
1892 val = get_local_var_value(var);
1894 /* handle any expansions */
1896 debug_printf_expand("expand: length of '%s' = ", val);
1897 val = utoa(val ? strlen(val) : 0);
1898 debug_printf_expand("%s\n", val);
1899 } else if (exp_off) {
1900 if (exp_op == '%' || exp_op == '#') {
1901 /* we need to do a pattern match */
1904 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1905 if (exp_op == *exp_word) /* ## or %% */
1907 val = dyn_val = xstrdup(val);
1908 loc = scan(dyn_val, exp_word, zero);
1914 /* we need to do an expansion */
1915 int exp_test = (!val || (exp_null && !val[0]));
1917 exp_test = !exp_test;
1918 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1919 exp_null ? "true" : "false", exp_test);
1922 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1926 if (exp_op == '=') {
1927 if (isdigit(var[0]) || var[0] == '#') {
1928 maybe_die(var, "special vars cannot assign in this way");
1931 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1932 sprintf(new_var, "%s=%s", var, val);
1933 set_local_var(new_var, -1, 0);
1939 var[exp_off] = exp_save;
1943 #if ENABLE_HUSH_TICK
1946 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1947 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1949 /* unquoted var's contents should be globbed, so don't escape */
1950 smallint sv = output->o_escape;
1951 output->o_escape = 0;
1952 n = expand_on_ifs(output, n, val);
1954 output->o_escape = sv;
1956 } else { /* quoted $VAR, val will be appended below */
1957 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1960 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1962 o_addQstr(output, val, strlen(val));
1966 /* Do the check to avoid writing to a const string */
1967 if (*p != SPECIAL_VAR_SYMBOL)
1968 *p = SPECIAL_VAR_SYMBOL;
1970 #if ENABLE_HUSH_TICK
1971 o_free(&subst_result);
1974 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1977 debug_print_list("expand_vars_to_list[a]", output, n);
1978 /* this part is literal, and it was already pre-quoted
1979 * if needed (much earlier), do not use o_addQstr here! */
1980 o_addstr_with_NUL(output, arg);
1981 debug_print_list("expand_vars_to_list[b]", output, n);
1982 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1983 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1986 /* allow to reuse list[n] later without re-growth */
1987 output->has_empty_slot = 1;
1989 o_addchr(output, '\0');
1994 static char **expand_variables(char **argv, int or_mask)
1999 o_string output = NULL_O_STRING;
2001 if (or_mask & 0x100) {
2002 output.o_escape = 1; /* protect against globbing for "$var" */
2003 /* (unquoted $var will temporarily switch it off) */
2010 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2013 debug_print_list("expand_variables", &output, n);
2015 /* output.data (malloced in one block) gets returned in "list" */
2016 list = o_finalize_list(&output, n);
2017 debug_print_strings("expand_variables[1]", list);
2021 static char **expand_strvec_to_strvec(char **argv)
2023 return expand_variables(argv, 0x100);
2026 /* Used for expansion of right hand of assignments */
2027 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2029 static char *expand_string_to_string(const char *str)
2031 char *argv[2], **list;
2033 argv[0] = (char*)str;
2035 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2037 if (!list[0] || list[1])
2038 bb_error_msg_and_die("BUG in varexp2");
2039 /* actually, just move string 2*sizeof(char*) bytes back */
2040 overlapping_strcpy((char*)list, list[0]);
2041 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2045 /* Used for "eval" builtin */
2046 static char* expand_strvec_to_string(char **argv)
2050 list = expand_variables(argv, 0x80);
2051 /* Convert all NULs to spaces */
2056 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2057 bb_error_msg_and_die("BUG in varexp3");
2058 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2062 overlapping_strcpy((char*)list, list[0]);
2063 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2067 static char **expand_assignments(char **argv, int count)
2071 /* Expand assignments into one string each */
2072 for (i = 0; i < count; i++) {
2073 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2080 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2081 #define clean_up_after_re_execute() ((void)0)
2082 static void reset_traps_to_defaults(void)
2090 for (sig = 0; sig < NSIG; sig++) {
2094 G.traps[sig] = NULL;
2095 /* There is no signal for 0 (EXIT) */
2098 /* there was a trap handler, we are removing it
2099 * (if sig has non-DFL handling,
2100 * we don't need to do anything) */
2101 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2103 sigdelset(&G.blocked_set, sig);
2107 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2112 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2113 static void re_execute_shell(const char *s, int is_heredoc)
2115 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2116 struct variable *cur;
2117 char **argv, **pp, **pp2;
2120 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2121 , (unsigned) G.root_pid
2122 , (unsigned) G.last_bg_pid
2123 , (unsigned) G.last_exitcode
2124 USE_HUSH_LOOPS(, G.depth_of_loop)
2126 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2127 * 3:-c 4:<cmd> <argN...> 5:NULL
2129 cnt = 5 + G.global_argc;
2130 for (cur = G.top_var; cur; cur = cur->next) {
2131 if (!cur->flg_export || cur->flg_read_only)
2134 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2135 *pp++ = (char *) G.argv0_for_re_execing;
2137 for (cur = G.top_var; cur; cur = cur->next) {
2138 if (cur->varstr == hush_version_str)
2140 if (cur->flg_read_only) {
2141 *pp++ = (char *) "-R";
2142 *pp++ = cur->varstr;
2143 } else if (!cur->flg_export) {
2144 *pp++ = (char *) "-V";
2145 *pp++ = cur->varstr;
2148 //TODO: pass functions
2149 /* We can pass activated traps here. Say, -Tnn:trap_string
2151 * However, POSIX says that subshells reset signals with traps
2153 * I tested bash-3.2 and it not only does that with true subshells
2154 * of the form ( list ), but with any forked children shells.
2155 * I set trap "echo W" WINCH; and then tried:
2157 * { echo 1; sleep 20; echo 2; } &
2158 * while true; do echo 1; sleep 20; echo 2; break; done &
2159 * true | { echo 1; sleep 20; echo 2; } | cat
2161 * In all these cases sending SIGWINCH to the child shell
2162 * did not run the trap. If I add trap "echo V" WINCH;
2163 * _inside_ group (just before echo 1), it works.
2165 * I conclude it means we don't need to pass active traps here.
2166 * exec syscall below resets them to SIG_DFL for us.
2168 *pp++ = (char *) (is_heredoc ? "-<" : "-c");
2170 pp2 = G.global_argv;
2173 /* *pp = NULL; - is already there */
2175 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2176 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2177 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2178 /* Fallback. Useful for init=/bin/hush usage etc */
2179 if (G.argv0_for_re_execing[0] == '/')
2180 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2181 xfunc_error_retval = 127;
2182 bb_error_msg_and_die("can't re-execute the shell");
2185 static void clean_up_after_re_execute(void)
2187 char **pp = G.argv_from_re_execing;
2189 /* Must match re_execute_shell's allocations (if any) */
2191 G.argv_from_re_execing = NULL;
2194 #endif /* !BB_MMU */
2197 static void setup_heredoc(int fd, const char *heredoc)
2199 struct fd_pair pair;
2204 xmove_fd(pair.rd, fd);
2206 len = strlen(heredoc);
2207 /* Try writing without forking. Newer kernels have
2208 * dynamically growing pipes. Must use non-blocking write! */
2211 written = write(pair.wr, heredoc, len);
2221 ndelay_off(pair.wr);
2223 /* Okay, pipe buffer was not big enough */
2224 /* Note: we must not create a stray child (bastard? :)
2225 * for the unsuspecting parent process. Child creates a grandchild
2226 * and exits before parent execs the process which consumes heredoc
2227 * (that exec happens after we return from this function) */
2230 bb_perror_msg_and_die("vfork");
2233 pid = BB_MMU ? fork() : vfork();
2235 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2239 close(fd); /* read side of the pipe */
2241 full_write(pair.wr, heredoc, len); /* may loop or block */
2244 /* Delegate blocking writes to another process */
2245 disable_restore_tty_pgrp_on_exit();
2246 xmove_fd(pair.wr, STDOUT_FILENO);
2247 re_execute_shell(heredoc, 1);
2251 enable_restore_tty_pgrp_on_exit();
2252 clean_up_after_re_execute();
2254 wait(NULL); /* wait till child has died */
2257 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2258 * and stderr if they are redirected. */
2259 static int setup_redirects(struct command *prog, int squirrel[])
2261 //TODO: no callers ever check return value - ?!
2263 struct redir_struct *redir;
2265 for (redir = prog->redirects; redir; redir = redir->next) {
2266 if (redir->rd_type == REDIRECT_HEREDOC2) {
2267 if (squirrel && redir->rd_fd < 3) {
2268 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2270 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2272 debug_printf_parse("set heredoc '%s'\n",
2273 redir->rd_filename);
2274 setup_heredoc(redir->rd_fd, redir->rd_filename);
2278 if (redir->rd_dup == -1) {
2280 if (redir->rd_filename == NULL) {
2281 /* Something went wrong in the parse.
2282 * Pretend it didn't happen */
2285 mode = redir_table[redir->rd_type].mode;
2286 //TODO: check redir for names like '\\'
2287 p = expand_string_to_string(redir->rd_filename);
2288 openfd = open_or_warn(p, mode);
2291 /* this could get lost if stderr has been redirected, but
2292 * bash and ash both lose it as well (though zsh doesn't!) */
2293 //what the above comment tries to say?
2297 openfd = redir->rd_dup;
2300 if (openfd != redir->rd_fd) {
2301 if (squirrel && redir->rd_fd < 3) {
2302 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2305 /* "-" means "close me" and we use -3 for that */
2306 close(redir->rd_fd);
2308 dup2(openfd, redir->rd_fd);
2309 if (redir->rd_dup == -1)
2317 static void restore_redirects(int squirrel[])
2320 for (i = 0; i < 3; i++) {
2323 /* We simply die on error */
2331 #define free_pipe_list(head, indent) free_pipe_list(head)
2332 #define free_pipe(pi, indent) free_pipe(pi)
2334 static void free_pipe_list(struct pipe *head, int indent);
2336 /* Return code is the exit status of the pipe */
2337 static void free_pipe(struct pipe *pi, int indent)
2340 struct command *command;
2341 struct redir_struct *r, *rnext;
2344 if (pi->stopped_cmds > 0) /* why? */
2346 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2347 for (i = 0; i < pi->num_cmds; i++) {
2348 command = &pi->cmds[i];
2349 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2350 if (command->argv) {
2351 for (a = 0, p = command->argv; *p; a++, p++) {
2352 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2354 free_strings(command->argv);
2355 command->argv = NULL;
2357 /* not "else if": on syntax error, we may have both! */
2358 if (command->group) {
2359 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2360 free_pipe_list(command->group, indent+3);
2361 debug_printf_clean("%s end group\n", indenter(indent));
2362 command->group = NULL;
2365 free(command->group_as_string);
2366 command->group_as_string = NULL;
2368 for (r = command->redirects; r; r = rnext) {
2369 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2370 if (r->rd_dup == -1) {
2371 /* guard against the case >$FOO, where foo is unset or blank */
2372 if (r->rd_filename) {
2373 debug_printf_clean(" %s\n", r->rd_filename);
2374 free(r->rd_filename);
2375 r->rd_filename = NULL;
2378 debug_printf_clean("&%d\n", r->rd_dup);
2383 command->redirects = NULL;
2385 free(pi->cmds); /* children are an array, they get freed all at once */
2393 static void free_pipe_list(struct pipe *head, int indent)
2395 struct pipe *pi, *next;
2397 for (pi = head; pi; pi = next) {
2399 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2401 free_pipe(pi, indent);
2402 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2404 /*pi->next = NULL;*/
2411 typedef struct nommu_save_t {
2417 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2418 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2419 #define pseudo_exec(nommu_save, command, argv_expanded) \
2420 pseudo_exec(command, argv_expanded)
2423 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2425 * XXX no exit() here. If you don't exec, use _exit instead.
2426 * The at_exit handlers apparently confuse the calling process,
2427 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2428 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2429 char **argv, int assignment_cnt,
2430 char **argv_expanded) NORETURN;
2431 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2432 char **argv, int assignment_cnt,
2433 char **argv_expanded)
2437 /* Case when we are here: ... | var=val | ... */
2438 if (!argv[assignment_cnt])
2439 _exit(EXIT_SUCCESS);
2441 new_env = expand_assignments(argv, assignment_cnt);
2443 putenv_all(new_env);
2444 free(new_env); /* optional */
2446 nommu_save->new_env = new_env;
2447 nommu_save->old_env = putenv_all_and_save_old(new_env);
2449 if (argv_expanded) {
2450 argv = argv_expanded;
2452 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2454 nommu_save->argv = argv;
2458 /* On NOMMU, we must never block!
2459 * Example: { sleep 99999 | read line } & echo Ok
2460 * read builtin will block on read syscall, leaving parent blocked
2461 * in vfork. Therefore we can't do this:
2464 /* Check if the command matches any of the builtins.
2465 * Depending on context, this might be redundant. But it's
2466 * easier to waste a few CPU cycles than it is to figure out
2467 * if this is one of those cases.
2471 const struct built_in_command *x;
2472 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2473 if (strcmp(argv[0], x->cmd) == 0) {
2474 debug_printf_exec("running builtin '%s'\n",
2476 rcode = x->function(argv);
2484 #if ENABLE_FEATURE_SH_STANDALONE
2485 /* Check if the command matches any busybox applets */
2486 if (strchr(argv[0], '/') == NULL) {
2487 int a = find_applet_by_name(argv[0]);
2489 #if BB_MMU /* see above why on NOMMU it is not allowed */
2490 if (APPLET_IS_NOEXEC(a)) {
2491 debug_printf_exec("running applet '%s'\n", argv[0]);
2492 run_applet_no_and_exit(a, argv);
2495 /* Re-exec ourselves */
2496 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2497 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2498 execv(bb_busybox_exec_path, argv);
2499 /* If they called chroot or otherwise made the binary no longer
2500 * executable, fall through */
2505 debug_printf_exec("execing '%s'\n", argv[0]);
2506 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2507 execvp(argv[0], argv);
2508 bb_perror_msg("can't exec '%s'", argv[0]);
2509 _exit(EXIT_FAILURE);
2512 static int run_list(struct pipe *pi);
2514 /* Called after [v]fork() in run_pipe
2516 static void pseudo_exec(nommu_save_t *nommu_save,
2517 struct command *command,
2518 char **argv_expanded) NORETURN;
2519 static void pseudo_exec(nommu_save_t *nommu_save,
2520 struct command *command,
2521 char **argv_expanded)
2523 if (command->argv) {
2524 pseudo_exec_argv(nommu_save, command->argv,
2525 command->assignment_cnt, argv_expanded);
2528 if (command->group) {
2529 /* Cases when we are here:
2532 * ... | ( list ) | ...
2533 * ... | { list } | ...
2537 debug_printf_exec("pseudo_exec: run_list\n");
2538 reset_traps_to_defaults();
2539 rcode = run_list(command->group);
2540 /* OK to leak memory by not calling free_pipe_list,
2541 * since this process is about to exit */
2544 re_execute_shell(command->group_as_string, 0);
2548 /* Case when we are here: ... | >file */
2549 debug_printf_exec("pseudo_exec'ed null command\n");
2550 _exit(EXIT_SUCCESS);
2554 static const char *get_cmdtext(struct pipe *pi)
2560 /* This is subtle. ->cmdtext is created only on first backgrounding.
2561 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2562 * On subsequent bg argv is trashed, but we won't use it */
2565 argv = pi->cmds[0].argv;
2566 if (!argv || !argv[0]) {
2567 pi->cmdtext = xzalloc(1);
2572 do len += strlen(*argv) + 1; while (*++argv);
2573 pi->cmdtext = p = xmalloc(len);
2574 argv = pi->cmds[0].argv;
2576 len = strlen(*argv);
2577 memcpy(p, *argv, len);
2585 static void insert_bg_job(struct pipe *pi)
2587 struct pipe *thejob;
2590 /* Linear search for the ID of the job to use */
2592 for (thejob = G.job_list; thejob; thejob = thejob->next)
2593 if (thejob->jobid >= pi->jobid)
2594 pi->jobid = thejob->jobid + 1;
2596 /* Add thejob to the list of running jobs */
2598 thejob = G.job_list = xmalloc(sizeof(*thejob));
2600 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2602 thejob->next = xmalloc(sizeof(*thejob));
2603 thejob = thejob->next;
2606 /* Physically copy the struct job */
2607 memcpy(thejob, pi, sizeof(struct pipe));
2608 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2609 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2610 for (i = 0; i < pi->num_cmds; i++) {
2611 // TODO: do we really need to have so many fields which are just dead weight
2612 // at execution stage?
2613 thejob->cmds[i].pid = pi->cmds[i].pid;
2614 /* all other fields are not used and stay zero */
2616 thejob->next = NULL;
2617 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2619 /* We don't wait for background thejobs to return -- append it
2620 to the list of backgrounded thejobs and leave it alone */
2621 if (G_interactive_fd)
2622 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2623 G.last_bg_pid = thejob->cmds[0].pid;
2624 G.last_jobid = thejob->jobid;
2627 static void remove_bg_job(struct pipe *pi)
2629 struct pipe *prev_pipe;
2631 if (pi == G.job_list) {
2632 G.job_list = pi->next;
2634 prev_pipe = G.job_list;
2635 while (prev_pipe->next != pi)
2636 prev_pipe = prev_pipe->next;
2637 prev_pipe->next = pi->next;
2640 G.last_jobid = G.job_list->jobid;
2645 /* Remove a backgrounded job */
2646 static void delete_finished_bg_job(struct pipe *pi)
2649 pi->stopped_cmds = 0;
2655 /* Check to see if any processes have exited -- if they
2656 * have, figure out why and see if a job has completed */
2657 static int checkjobs(struct pipe* fg_pipe)
2667 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2670 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2671 // /* avoid doing syscall, nothing there anyway */
2674 attributes = WUNTRACED;
2675 if (fg_pipe == NULL)
2676 attributes |= WNOHANG;
2678 /* Do we do this right?
2679 * bash-3.00# sleep 20 | false
2681 * [3]+ Stopped sleep 20 | false
2682 * bash-3.00# echo $?
2683 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2686 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2687 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2688 // + killall -STOP cat
2695 // i = G.count_SIGCHLD;
2696 childpid = waitpid(-1, &status, attributes);
2697 if (childpid <= 0) {
2698 if (childpid && errno != ECHILD)
2699 bb_perror_msg("waitpid");
2700 // else /* Until next SIGCHLD, waitpid's are useless */
2701 // G.handled_SIGCHLD = i;
2704 dead = WIFEXITED(status) || WIFSIGNALED(status);
2707 if (WIFSTOPPED(status))
2708 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2709 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2710 if (WIFSIGNALED(status))
2711 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2712 childpid, WTERMSIG(status), WEXITSTATUS(status));
2713 if (WIFEXITED(status))
2714 debug_printf_jobs("pid %d exited, exitcode %d\n",
2715 childpid, WEXITSTATUS(status));
2717 /* Were we asked to wait for fg pipe? */
2719 for (i = 0; i < fg_pipe->num_cmds; i++) {
2720 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2721 if (fg_pipe->cmds[i].pid != childpid)
2723 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2725 fg_pipe->cmds[i].pid = 0;
2726 fg_pipe->alive_cmds--;
2727 if (i == fg_pipe->num_cmds - 1) {
2728 /* last process gives overall exitstatus */
2729 rcode = WEXITSTATUS(status);
2730 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2733 fg_pipe->cmds[i].is_stopped = 1;
2734 fg_pipe->stopped_cmds++;
2736 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2737 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2738 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2739 /* All processes in fg pipe have exited/stopped */
2741 if (fg_pipe->alive_cmds)
2742 insert_bg_job(fg_pipe);
2746 /* There are still running processes in the fg pipe */
2747 goto wait_more; /* do waitpid again */
2749 /* it wasnt fg_pipe, look for process in bg pipes */
2753 /* We asked to wait for bg or orphaned children */
2754 /* No need to remember exitcode in this case */
2755 for (pi = G.job_list; pi; pi = pi->next) {
2756 for (i = 0; i < pi->num_cmds; i++) {
2757 if (pi->cmds[i].pid == childpid)
2758 goto found_pi_and_prognum;
2761 /* Happens when shell is used as init process (init=/bin/sh) */
2762 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2763 continue; /* do waitpid again */
2765 found_pi_and_prognum:
2768 pi->cmds[i].pid = 0;
2770 if (!pi->alive_cmds) {
2771 if (G_interactive_fd)
2772 printf(JOB_STATUS_FORMAT, pi->jobid,
2773 "Done", pi->cmdtext);
2774 delete_finished_bg_job(pi);
2778 pi->cmds[i].is_stopped = 1;
2782 } /* while (waitpid succeeds)... */
2788 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2791 int rcode = checkjobs(fg_pipe);
2792 /* Job finished, move the shell to the foreground */
2793 p = getpgid(0); /* pgid of our process */
2794 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2795 tcsetpgrp(G_interactive_fd, p);
2800 /* Start all the jobs, but don't wait for anything to finish.
2803 * Return code is normally -1, when the caller has to wait for children
2804 * to finish to determine the exit status of the pipe. If the pipe
2805 * is a simple builtin command, however, the action is done by the
2806 * time run_pipe returns, and the exit code is provided as the
2809 * Returns -1 only if started some children. IOW: we have to
2810 * mask out retvals of builtins etc with 0xff!
2812 * The only case when we do not need to [v]fork is when the pipe
2813 * is single, non-backgrounded, non-subshell command. Examples:
2814 * cmd ; ... { list } ; ...
2815 * cmd && ... { list } && ...
2816 * cmd || ... { list } || ...
2817 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2818 * or (if SH_STANDALONE) an applet, and we can run the { list }
2819 * with run_list(). If it isn't one of these, we fork and exec cmd.
2821 * Cases when we must fork:
2822 * non-single: cmd | cmd
2823 * backgrounded: cmd & { list } &
2824 * subshell: ( list ) [&]
2826 static int run_pipe(struct pipe *pi)
2828 static const char *const null_ptr = NULL;
2831 int pipefds[2]; /* pipefds[0] is for reading */
2832 struct command *command;
2833 char **argv_expanded;
2836 /* it is not always needed, but we aim to smaller code */
2837 int squirrel[] = { -1, -1, -1 };
2840 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2842 USE_HUSH_JOB(pi->pgrp = -1;)
2843 pi->stopped_cmds = 0;
2844 command = &(pi->cmds[0]);
2845 argv_expanded = NULL;
2847 if (pi->num_cmds != 1
2848 || pi->followup == PIPE_BG
2849 || command->grp_type == GRP_SUBSHELL
2856 debug_printf_exec(": group:%p argv:'%s'\n",
2857 command->group, command->argv ? command->argv[0] : "NONE");
2859 if (command->group) {
2860 #if ENABLE_HUSH_FUNCTIONS
2861 if (command->grp_type == GRP_FUNCTION) {
2862 /* func () { list } */
2863 bb_error_msg("here we ought to remember function definition, and go on");
2864 return EXIT_SUCCESS;
2868 debug_printf("non-subshell group\n");
2869 setup_redirects(command, squirrel);
2870 debug_printf_exec(": run_list\n");
2871 rcode = run_list(command->group) & 0xff;
2872 restore_redirects(squirrel);
2873 debug_printf_exec("run_pipe return %d\n", rcode);
2874 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2878 argv = command->argv ? command->argv : (char **) &null_ptr;
2880 const struct built_in_command *x;
2881 char **new_env = NULL;
2882 char **old_env = NULL;
2884 if (argv[command->assignment_cnt] == NULL) {
2885 /* Assignments, but no command */
2886 /* Ensure redirects take effect. Try "a=t >file" */
2887 setup_redirects(command, squirrel);
2888 restore_redirects(squirrel);
2889 /* Set shell variables */
2891 p = expand_string_to_string(*argv);
2892 debug_printf_exec("set shell var:'%s'->'%s'\n",
2894 set_local_var(p, 0, 0);
2897 /* Do we need to flag set_local_var() errors?
2898 * "assignment to readonly var" and "putenv error"
2900 return EXIT_SUCCESS;
2903 /* Expand the rest into (possibly) many strings each */
2904 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2906 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2907 if (strcmp(argv_expanded[0], x->cmd) != 0)
2909 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2910 debug_printf("exec with redirects only\n");
2911 setup_redirects(command, NULL);
2912 rcode = EXIT_SUCCESS;
2913 goto clean_up_and_ret1;
2915 debug_printf("builtin inline %s\n", argv_expanded[0]);
2916 /* XXX setup_redirects acts on file descriptors, not FILEs.
2917 * This is perfect for work that comes after exec().
2918 * Is it really safe for inline use? Experimentally,
2919 * things seem to work with glibc. */
2920 setup_redirects(command, squirrel);
2921 new_env = expand_assignments(argv, command->assignment_cnt);
2922 old_env = putenv_all_and_save_old(new_env);
2923 debug_printf_exec(": builtin '%s' '%s'...\n",
2924 x->cmd, argv_expanded[1]);
2925 rcode = x->function(argv_expanded) & 0xff;
2926 #if ENABLE_FEATURE_SH_STANDALONE
2929 restore_redirects(squirrel);
2930 free_strings_and_unsetenv(new_env, 1);
2931 putenv_all(old_env);
2932 free(old_env); /* not free_strings()! */
2934 free(argv_expanded);
2935 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2936 debug_printf_exec("run_pipe return %d\n", rcode);
2939 #if ENABLE_FEATURE_SH_STANDALONE
2940 i = find_applet_by_name(argv_expanded[0]);
2941 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2942 setup_redirects(command, squirrel);
2943 save_nofork_data(&G.nofork_save);
2944 new_env = expand_assignments(argv, command->assignment_cnt);
2945 old_env = putenv_all_and_save_old(new_env);
2946 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2947 argv_expanded[0], argv_expanded[1]);
2948 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2949 goto clean_up_and_ret;
2952 /* It is neither builtin nor applet. We must fork. */
2956 /* NB: argv_expanded may already be created, and that
2957 * might include `cmd` runs! Do not rerun it! We *must*
2958 * use argv_expanded if it's non-NULL */
2960 /* Going to fork a child per each pipe member */
2964 for (i = 0; i < pi->num_cmds; i++) {
2966 volatile nommu_save_t nommu_save;
2967 nommu_save.new_env = NULL;
2968 nommu_save.old_env = NULL;
2969 nommu_save.argv = NULL;
2971 command = &(pi->cmds[i]);
2972 if (command->argv) {
2973 debug_printf_exec(": pipe member '%s' '%s'...\n",
2974 command->argv[0], command->argv[1]);
2976 debug_printf_exec(": pipe member with no argv\n");
2979 /* pipes are inserted between pairs of commands */
2982 if ((i + 1) < pi->num_cmds)
2985 command->pid = BB_MMU ? fork() : vfork();
2986 if (!command->pid) { /* child */
2988 disable_restore_tty_pgrp_on_exit();
2990 /* Every child adds itself to new process group
2991 * with pgid == pid_of_first_child_in_pipe */
2992 if (G.run_list_level == 1 && G_interactive_fd) {
2995 if (pgrp < 0) /* true for 1st process only */
2997 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2998 /* We do it in *every* child, not just first,
3000 tcsetpgrp(G_interactive_fd, pgrp);
3004 xmove_fd(nextin, 0);
3005 xmove_fd(pipefds[1], 1); /* write end */
3007 close(pipefds[0]); /* read end */
3008 /* Like bash, explicit redirects override pipes,
3009 * and the pipe fd is available for dup'ing. */
3010 setup_redirects(command, NULL);
3012 /* Restore default handlers just prior to exec */
3013 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3015 /* Stores to nommu_save list of env vars putenv'ed
3016 * (NOMMU, on MMU we don't need that) */
3017 /* cast away volatility... */
3018 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3019 /* pseudo_exec() does not return */
3022 /* parent or error */
3023 enable_restore_tty_pgrp_on_exit();
3025 /* Clean up after vforked child */
3026 clean_up_after_re_execute();
3027 free(nommu_save.argv);
3028 free_strings_and_unsetenv(nommu_save.new_env, 1);
3029 putenv_all(nommu_save.old_env);
3031 free(argv_expanded);
3032 argv_expanded = NULL;
3033 if (command->pid < 0) { /* [v]fork failed */
3034 /* Clearly indicate, was it fork or vfork */
3035 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3039 /* Second and next children need to know pid of first one */
3041 pi->pgrp = command->pid;
3047 if ((i + 1) < pi->num_cmds)
3048 close(pipefds[1]); /* write end */
3049 /* Pass read (output) pipe end to next iteration */
3050 nextin = pipefds[0];
3053 if (!pi->alive_cmds) {
3054 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3058 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3062 #ifndef debug_print_tree
3063 static void debug_print_tree(struct pipe *pi, int lvl)
3065 static const char *const PIPE[] = {
3071 static const char *RES[] = {
3072 [RES_NONE ] = "NONE" ,
3075 [RES_THEN ] = "THEN" ,
3076 [RES_ELIF ] = "ELIF" ,
3077 [RES_ELSE ] = "ELSE" ,
3080 #if ENABLE_HUSH_LOOPS
3081 [RES_FOR ] = "FOR" ,
3082 [RES_WHILE] = "WHILE",
3083 [RES_UNTIL] = "UNTIL",
3085 [RES_DONE ] = "DONE" ,
3087 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3090 #if ENABLE_HUSH_CASE
3091 [RES_CASE ] = "CASE" ,
3092 [RES_MATCH] = "MATCH",
3093 [RES_CASEI] = "CASEI",
3094 [RES_ESAC ] = "ESAC" ,
3096 [RES_XXXX ] = "XXXX" ,
3097 [RES_SNTX ] = "SNTX" ,
3099 static const char *const GRPTYPE[] = {
3102 #if ENABLE_HUSH_FUNCTIONS
3111 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3112 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3114 while (prn < pi->num_cmds) {
3115 struct command *command = &pi->cmds[prn];
3116 char **argv = command->argv;
3118 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3120 command->assignment_cnt);
3121 if (command->group) {
3122 fprintf(stderr, " group %s: (argv=%p)\n",
3123 GRPTYPE[command->grp_type],
3125 debug_print_tree(command->group, lvl+1);
3129 if (argv) while (*argv) {
3130 fprintf(stderr, " '%s'", *argv);
3133 fprintf(stderr, "\n");
3142 /* NB: called by pseudo_exec, and therefore must not modify any
3143 * global data until exec/_exit (we can be a child after vfork!) */
3144 static int run_list(struct pipe *pi)
3146 #if ENABLE_HUSH_CASE
3147 char *case_word = NULL;
3149 #if ENABLE_HUSH_LOOPS
3150 struct pipe *loop_top = NULL;
3151 char *for_varname = NULL;
3152 char **for_lcur = NULL;
3153 char **for_list = NULL;
3155 smallint last_followup;
3157 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3158 smalluint cond_code = 0;
3160 enum { cond_code = 0 };
3163 smallint rword; /* enum reserved_style */
3164 smallint last_rword; /* ditto */
3167 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3169 #if ENABLE_HUSH_LOOPS
3170 /* Check syntax for "for" */
3171 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3172 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3174 /* current word is FOR or IN (BOLD in comments below) */
3175 if (cpipe->next == NULL) {
3176 syntax("malformed for");
3177 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3180 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3181 if (cpipe->next->res_word == RES_DO)
3183 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3184 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3185 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3187 syntax("malformed for");
3188 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3194 /* Past this point, all code paths should jump to ret: label
3195 * in order to return, no direct "return" statements please.
3196 * This helps to ensure that no memory is leaked. */
3198 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3201 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3202 * We are saving state before entering outermost list ("while...done")
3203 * so that ctrl-Z will correctly background _entire_ outermost list,
3204 * not just a part of it (like "sleep 1 | exit 2") */
3205 if (++G.run_list_level == 1 && G_interactive_fd) {
3206 if (sigsetjmp(G.toplevel_jb, 1)) {
3207 /* ctrl-Z forked and we are parent; or ctrl-C.
3208 * Sighandler has longjmped us here */
3209 signal(SIGINT, SIG_IGN);
3210 signal(SIGTSTP, SIG_IGN);
3211 /* Restore level (we can be coming from deep inside
3213 G.run_list_level = 1;
3214 #if ENABLE_FEATURE_SH_STANDALONE
3215 if (G.nofork_save.saved) { /* if save area is valid */
3216 debug_printf_jobs("exiting nofork early\n");
3217 restore_nofork_data(&G.nofork_save);
3220 //// if (G.ctrl_z_flag) {
3221 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3222 //// * Remember this child as background job */
3223 //// insert_bg_job(pi);
3225 /* ctrl-C. We just stop doing whatever we were doing */
3228 USE_HUSH_LOOPS(loop_top = NULL;)
3229 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3233 //// /* ctrl-Z handler will store pid etc in pi */
3234 //// G.toplevel_list = pi;
3235 //// G.ctrl_z_flag = 0;
3236 ////#if ENABLE_FEATURE_SH_STANDALONE
3237 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3239 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3240 //// signal(SIGINT, handler_ctrl_c);
3246 last_rword = RES_XXXX;
3248 last_followup = PIPE_SEQ;
3249 rcode = G.last_exitcode;
3251 /* Go through list of pipes, (maybe) executing them. */
3252 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3256 IF_HAS_KEYWORDS(rword = pi->res_word;)
3257 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3258 rword, cond_code, last_rword);
3259 #if ENABLE_HUSH_LOOPS
3260 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3261 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3263 /* start of a loop: remember where loop starts */
3268 /* Still in the same "if...", "then..." or "do..." branch? */
3269 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3270 if ((rcode == 0 && last_followup == PIPE_OR)
3271 || (rcode != 0 && last_followup == PIPE_AND)
3273 /* It is "<true> || CMD" or "<false> && CMD"
3274 * and we should not execute CMD */
3275 debug_printf_exec("skipped cmd because of || or &&\n");
3276 last_followup = pi->followup;
3280 last_followup = pi->followup;
3281 IF_HAS_KEYWORDS(last_rword = rword;)
3284 if (rword == RES_THEN) {
3285 /* if false; then ... fi has exitcode 0! */
3286 G.last_exitcode = rcode = EXIT_SUCCESS;
3287 /* "if <false> THEN cmd": skip cmd */
3291 if (rword == RES_ELSE || rword == RES_ELIF) {
3292 /* "if <true> then ... ELSE/ELIF cmd":
3293 * skip cmd and all following ones */
3298 #if ENABLE_HUSH_LOOPS
3299 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3301 /* first loop through for */
3303 static const char encoded_dollar_at[] ALIGN1 = {
3304 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3305 }; /* encoded representation of "$@" */
3306 static const char *const encoded_dollar_at_argv[] = {
3307 encoded_dollar_at, NULL
3308 }; /* argv list with one element: "$@" */
3311 vals = (char**)encoded_dollar_at_argv;
3312 if (pi->next->res_word == RES_IN) {
3313 /* if no variable values after "in" we skip "for" */
3314 if (!pi->next->cmds[0].argv) {
3315 G.last_exitcode = rcode = EXIT_SUCCESS;
3316 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3319 vals = pi->next->cmds[0].argv;
3320 } /* else: "for var; do..." -> assume "$@" list */
3321 /* create list of variable values */
3322 debug_print_strings("for_list made from", vals);
3323 for_list = expand_strvec_to_strvec(vals);
3324 for_lcur = for_list;
3325 debug_print_strings("for_list", for_list);
3326 for_varname = pi->cmds[0].argv[0];
3327 pi->cmds[0].argv[0] = NULL;
3329 free(pi->cmds[0].argv[0]);
3331 /* "for" loop is over, clean up */
3335 pi->cmds[0].argv[0] = for_varname;
3338 /* Insert next value from for_lcur */
3339 //TODO: does it need escaping?
3340 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3341 pi->cmds[0].assignment_cnt = 1;
3343 if (rword == RES_IN) {
3344 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3346 if (rword == RES_DONE) {
3347 continue; /* "done" has no cmds too */
3350 #if ENABLE_HUSH_CASE
3351 if (rword == RES_CASE) {
3352 case_word = expand_strvec_to_string(pi->cmds->argv);
3355 if (rword == RES_MATCH) {
3358 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3360 /* all prev words didn't match, does this one match? */
3361 argv = pi->cmds->argv;
3363 char *pattern = expand_string_to_string(*argv);
3364 /* TODO: which FNM_xxx flags to use? */
3365 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3367 if (cond_code == 0) { /* match! we will execute this branch */
3368 free(case_word); /* make future "word)" stop */
3376 if (rword == RES_CASEI) { /* inside of a case branch */
3378 continue; /* not matched yet, skip this pipe */
3381 /* Just pressing <enter> in shell should check for jobs.
3382 * OTOH, in non-interactive shell this is useless
3383 * and only leads to extra job checks */
3384 if (pi->num_cmds == 0) {
3385 if (G_interactive_fd)
3386 goto check_jobs_and_continue;
3390 /* After analyzing all keywords and conditions, we decided
3391 * to execute this pipe. NB: have to do checkjobs(NULL)
3392 * after run_pipe to collect any background children,
3393 * even if list execution is to be stopped. */
3394 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3397 #if ENABLE_HUSH_LOOPS
3398 G.flag_break_continue = 0;
3400 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3402 /* We only ran a builtin: rcode is already known
3403 * and we don't need to wait for anything. */
3404 G.last_exitcode = rcode;
3405 debug_printf_exec(": builtin exitcode %d\n", rcode);
3406 check_and_run_traps(0);
3407 #if ENABLE_HUSH_LOOPS
3408 /* Was it "break" or "continue"? */
3409 if (G.flag_break_continue) {
3410 smallint fbc = G.flag_break_continue;
3411 /* We might fall into outer *loop*,
3412 * don't want to break it too */
3414 G.depth_break_continue--;
3415 if (G.depth_break_continue == 0)
3416 G.flag_break_continue = 0;
3417 /* else: e.g. "continue 2" should *break* once, *then* continue */
3418 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3419 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3420 goto check_jobs_and_break;
3421 /* "continue": simulate end of loop */
3426 } else if (pi->followup == PIPE_BG) {
3427 /* What does bash do with attempts to background builtins? */
3428 /* even bash 3.2 doesn't do that well with nested bg:
3429 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3430 * I'm NOT treating inner &'s as jobs */
3431 check_and_run_traps(0);
3433 if (G.run_list_level == 1)
3436 G.last_exitcode = rcode = EXIT_SUCCESS;
3437 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3440 if (G.run_list_level == 1 && G_interactive_fd) {
3441 /* Waits for completion, then fg's main shell */
3442 rcode = checkjobs_and_fg_shell(pi);
3443 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3444 check_and_run_traps(0);
3447 { /* This one just waits for completion */
3448 rcode = checkjobs(pi);
3449 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3450 check_and_run_traps(0);
3452 G.last_exitcode = rcode;
3456 /* Analyze how result affects subsequent commands */
3458 if (rword == RES_IF || rword == RES_ELIF)
3461 #if ENABLE_HUSH_LOOPS
3462 /* Beware of "while false; true; do ..."! */
3463 if (pi->next && pi->next->res_word == RES_DO) {
3464 if (rword == RES_WHILE) {
3466 /* "while false; do...done" - exitcode 0 */
3467 G.last_exitcode = rcode = EXIT_SUCCESS;
3468 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3469 goto check_jobs_and_break;
3472 if (rword == RES_UNTIL) {
3474 debug_printf_exec(": until expr is true: breaking\n");
3475 check_jobs_and_break:
3483 check_jobs_and_continue:
3488 //// if (G.ctrl_z_flag) {
3489 //// /* ctrl-Z forked somewhere in the past, we are the child,
3490 //// * and now we completed running the list. Exit. */
3496 //// if (!G.run_list_level && G_interactive_fd) {
3497 //// signal(SIGTSTP, SIG_IGN);
3498 //// signal(SIGINT, SIG_IGN);
3501 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3502 #if ENABLE_HUSH_LOOPS
3507 #if ENABLE_HUSH_CASE
3513 /* Select which version we will use */
3514 static int run_and_free_list(struct pipe *pi)
3517 debug_printf_exec("run_and_free_list entered\n");
3519 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3520 rcode = run_list(pi);
3522 /* free_pipe_list has the side effect of clearing memory.
3523 * In the long run that function can be merged with run_list,
3524 * but doing that now would hobble the debugging effort. */
3525 free_pipe_list(pi, /* indent: */ 0);
3526 debug_printf_exec("run_and_free_list return %d\n", rcode);
3531 static struct pipe *new_pipe(void)
3534 pi = xzalloc(sizeof(struct pipe));
3535 /*pi->followup = 0; - deliberately invalid value */
3536 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3540 /* Command (member of a pipe) is complete. The only possible error here
3541 * is out of memory, in which case xmalloc exits. */
3542 static int done_command(struct parse_context *ctx)
3544 /* The command is really already in the pipe structure, so
3545 * advance the pipe counter and make a new, null command. */
3546 struct pipe *pi = ctx->pipe;
3547 struct command *command = ctx->command;
3550 if (command->group == NULL
3551 && command->argv == NULL
3552 && command->redirects == NULL
3554 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3555 memset(command, 0, sizeof(*command)); /* paranoia */
3556 return pi->num_cmds;
3559 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3560 //debug_print_tree(ctx->list_head, 20);
3562 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3565 /* Only real trickiness here is that the uncommitted
3566 * command structure is not counted in pi->num_cmds. */
3567 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3568 command = &pi->cmds[pi->num_cmds];
3569 memset(command, 0, sizeof(*command));
3571 ctx->command = command;
3572 /* but ctx->pipe and ctx->list_head remain unchanged */
3574 return pi->num_cmds; /* used only for 0/nonzero check */
3577 static void done_pipe(struct parse_context *ctx, pipe_style type)
3581 debug_printf_parse("done_pipe entered, followup %d\n", type);
3582 /* Close previous command */
3583 not_null = done_command(ctx);
3584 ctx->pipe->followup = type;
3586 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3587 ctx->ctx_inverted = 0;
3588 ctx->pipe->res_word = ctx->ctx_res_w;
3591 /* Without this check, even just <enter> on command line generates
3592 * tree of three NOPs (!). Which is harmless but annoying.
3593 * IOW: it is safe to do it unconditionally.
3594 * RES_NONE case is for "for a in; do ..." (empty IN set)
3595 * and other cases to work. */
3598 || ctx->ctx_res_w == RES_FI
3599 || ctx->ctx_res_w == RES_DONE
3600 || ctx->ctx_res_w == RES_FOR
3601 || ctx->ctx_res_w == RES_IN
3602 || ctx->ctx_res_w == RES_ESAC
3606 debug_printf_parse("done_pipe: adding new pipe: "
3607 "not_null:%d ctx->ctx_res_w:%d\n",
3608 not_null, ctx->ctx_res_w);
3610 ctx->pipe->next = new_p;
3612 /* RES_THEN, RES_DO etc are "sticky" -
3613 * they remain set for commands inside if/while.
3614 * This is used to control execution.
3615 * RES_FOR and RES_IN are NOT sticky (needed to support
3616 * cases where variable or value happens to match a keyword):
3618 #if ENABLE_HUSH_LOOPS
3619 if (ctx->ctx_res_w == RES_FOR
3620 || ctx->ctx_res_w == RES_IN)
3621 ctx->ctx_res_w = RES_NONE;
3623 #if ENABLE_HUSH_CASE
3624 if (ctx->ctx_res_w == RES_MATCH)
3625 ctx->ctx_res_w = RES_CASEI;
3627 ctx->command = NULL; /* trick done_command below */
3628 /* Create the memory for command, roughly:
3629 * ctx->pipe->cmds = new struct command;
3630 * ctx->command = &ctx->pipe->cmds[0];
3633 //debug_print_tree(ctx->list_head, 10);
3635 debug_printf_parse("done_pipe return\n");
3638 static void initialize_context(struct parse_context *ctx)
3640 memset(ctx, 0, sizeof(*ctx));
3641 ctx->pipe = ctx->list_head = new_pipe();
3642 /* Create the memory for command, roughly:
3643 * ctx->pipe->cmds = new struct command;
3644 * ctx->command = &ctx->pipe->cmds[0];
3649 /* If a reserved word is found and processed, parse context is modified
3650 * and 1 is returned.
3653 struct reserved_combo {
3656 unsigned char assignment_flag;
3660 FLAG_END = (1 << RES_NONE ),
3662 FLAG_IF = (1 << RES_IF ),
3663 FLAG_THEN = (1 << RES_THEN ),
3664 FLAG_ELIF = (1 << RES_ELIF ),
3665 FLAG_ELSE = (1 << RES_ELSE ),
3666 FLAG_FI = (1 << RES_FI ),
3668 #if ENABLE_HUSH_LOOPS
3669 FLAG_FOR = (1 << RES_FOR ),
3670 FLAG_WHILE = (1 << RES_WHILE),
3671 FLAG_UNTIL = (1 << RES_UNTIL),
3672 FLAG_DO = (1 << RES_DO ),
3673 FLAG_DONE = (1 << RES_DONE ),
3674 FLAG_IN = (1 << RES_IN ),
3676 #if ENABLE_HUSH_CASE
3677 FLAG_MATCH = (1 << RES_MATCH),
3678 FLAG_ESAC = (1 << RES_ESAC ),
3680 FLAG_START = (1 << RES_XXXX ),
3683 static const struct reserved_combo* match_reserved_word(o_string *word)
3685 /* Mostly a list of accepted follow-up reserved words.
3686 * FLAG_END means we are done with the sequence, and are ready
3687 * to turn the compound list into a command.
3688 * FLAG_START means the word must start a new compound list.
3690 static const struct reserved_combo reserved_list[] = {
3692 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3693 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3694 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3695 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3696 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3697 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3699 #if ENABLE_HUSH_LOOPS
3700 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3701 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3702 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3703 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3704 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3705 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3707 #if ENABLE_HUSH_CASE
3708 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3709 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3712 const struct reserved_combo *r;
3714 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3715 if (strcmp(word->data, r->literal) == 0)
3720 static int reserved_word(o_string *word, struct parse_context *ctx)
3722 #if ENABLE_HUSH_CASE
3723 static const struct reserved_combo reserved_match = {
3724 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3727 const struct reserved_combo *r;
3729 r = match_reserved_word(word);
3733 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3734 #if ENABLE_HUSH_CASE
3735 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3736 /* "case word IN ..." - IN part starts first match part */
3737 r = &reserved_match;
3740 if (r->flag == 0) { /* '!' */
3741 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3742 syntax("! ! command");
3743 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3745 ctx->ctx_inverted = 1;
3748 if (r->flag & FLAG_START) {
3749 struct parse_context *old;
3750 old = xmalloc(sizeof(*old));
3751 debug_printf_parse("push stack %p\n", old);
3752 *old = *ctx; /* physical copy */
3753 initialize_context(ctx);
3755 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3757 ctx->ctx_res_w = RES_SNTX;
3760 ctx->ctx_res_w = r->res;
3761 ctx->old_flag = r->flag;
3762 if (ctx->old_flag & FLAG_END) {
3763 struct parse_context *old;
3764 done_pipe(ctx, PIPE_SEQ);
3765 debug_printf_parse("pop stack %p\n", ctx->stack);
3767 old->command->group = ctx->list_head;
3768 old->command->grp_type = GRP_NORMAL;
3770 o_addstr(&old->as_string, ctx->as_string.data);
3771 o_free_unsafe(&ctx->as_string);
3772 old->command->group_as_string = xstrdup(old->as_string.data);
3773 debug_printf_parse("pop, remembering as:'%s'\n",
3774 old->command->group_as_string);
3776 *ctx = *old; /* physical copy */
3779 word->o_assignment = r->assignment_flag;
3784 /* Word is complete, look at it and update parsing context.
3785 * Normal return is 0. Syntax errors return 1.
3786 * Note: on return, word is reset, but not o_free'd!
3788 static int done_word(o_string *word, struct parse_context *ctx)
3790 struct command *command = ctx->command;
3792 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3793 if (word->length == 0 && word->nonnull == 0) {
3794 debug_printf_parse("done_word return 0: true null, ignored\n");
3797 /* If this word wasn't an assignment, next ones definitely
3798 * can't be assignments. Even if they look like ones. */
3799 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3800 && word->o_assignment != WORD_IS_KEYWORD
3802 word->o_assignment = NOT_ASSIGNMENT;
3804 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3805 command->assignment_cnt++;
3806 word->o_assignment = MAYBE_ASSIGNMENT;
3809 if (ctx->pending_redirect) {
3810 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3811 * only if run as "bash", not "sh" */
3812 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3814 * ...the word that follows the redirection operator
3815 * shall be subjected to tilde expansion, parameter expansion,
3816 * command substitution, arithmetic expansion, and quote
3817 * removal. Pathname expansion shall not be performed
3818 * on the word by a non-interactive shell; an interactive
3819 * shell may perform it, but shall do so only when
3820 * the expansion would result in one word."
3822 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3823 word->o_assignment = NOT_ASSIGNMENT;
3824 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3826 /* "{ echo foo; } echo bar" - bad */
3827 /* NB: bash allows e.g.:
3828 * if true; then { echo foo; } fi
3829 * while if false; then false; fi do break; done
3831 * while if false; then false; fi; do; break; done
3833 if (command->group) {
3835 debug_printf_parse("done_word return 1: syntax error, "
3836 "groups and arglists don't mix\n");
3840 #if ENABLE_HUSH_CASE
3841 if (ctx->ctx_dsemicolon
3842 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3844 /* already done when ctx_dsemicolon was set to 1: */
3845 /* ctx->ctx_res_w = RES_MATCH; */
3846 ctx->ctx_dsemicolon = 0;
3849 if (!command->argv /* if it's the first word... */
3850 #if ENABLE_HUSH_LOOPS
3851 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3852 && ctx->ctx_res_w != RES_IN
3855 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3856 if (reserved_word(word, ctx)) {
3858 debug_printf_parse("done_word return %d\n",
3859 (ctx->ctx_res_w == RES_SNTX));
3860 return (ctx->ctx_res_w == RES_SNTX);
3864 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3865 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3866 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3867 /* (otherwise it's known to be not empty and is already safe) */
3869 /* exclude "$@" - it can expand to no word despite "" */
3870 char *p = word->data;
3871 while (p[0] == SPECIAL_VAR_SYMBOL
3872 && (p[1] & 0x7f) == '@'
3873 && p[2] == SPECIAL_VAR_SYMBOL
3877 if (p == word->data || p[0] != '\0') {
3878 /* saw no "$@", or not only "$@" but some
3879 * real text is there too */
3880 /* insert "empty variable" reference, this makes
3881 * e.g. "", $empty"" etc to not disappear */
3882 o_addchr(word, SPECIAL_VAR_SYMBOL);
3883 o_addchr(word, SPECIAL_VAR_SYMBOL);
3886 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3887 debug_print_strings("word appended to argv", command->argv);
3891 ctx->pending_redirect = NULL;
3893 #if ENABLE_HUSH_LOOPS
3894 /* Force FOR to have just one word (variable name) */
3895 /* NB: basically, this makes hush see "for v in ..." syntax as if
3896 * as it is "for v; in ...". FOR and IN become two pipe structs
3898 if (ctx->ctx_res_w == RES_FOR) {
3899 //TODO: check that command->argv[0] is a valid variable name!
3900 done_pipe(ctx, PIPE_SEQ);
3903 #if ENABLE_HUSH_CASE
3904 /* Force CASE to have just one word */
3905 if (ctx->ctx_res_w == RES_CASE) {
3906 done_pipe(ctx, PIPE_SEQ);
3909 debug_printf_parse("done_word return 0\n");
3914 /* Peek ahead in the input to find out if we have a "&n" construct,
3915 * as in "2>&1", that represents duplicating a file descriptor.
3916 * Return: -3 if >&- "close fd" construct is seen,
3917 * -2 (syntax error), -1 if no & was seen, or the number found.
3920 #define redirect_dup_num(as_string, input) \
3921 redirect_dup_num(input)
3923 static int redirect_dup_num(o_string *as_string, struct in_str *input)
3931 ch = i_getch(input); /* get the & */
3932 nommu_addchr(as_string, ch);
3935 ch = i_getch(input);
3936 nommu_addchr(as_string, ch);
3937 return -3; /* "-" represents "close me" */
3941 while (ch != EOF && isdigit(ch)) {
3942 d = d*10 + (ch-'0');
3944 ch = i_getch(input);
3945 nommu_addchr(as_string, ch);
3950 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3952 bb_error_msg("ambiguous redirect");
3956 /* Return code is 0 normally, 1 if a syntax error is detected
3958 static int parse_redirect(struct parse_context *ctx,
3961 struct in_str *input)
3963 struct command *command = ctx->command;
3964 struct redir_struct *redir;
3965 struct redir_struct **redirp;
3969 if (style != REDIRECT_HEREDOC) {
3970 /* Check for a '2>&1' type redirect */
3971 dup_num = redirect_dup_num(&ctx->as_string, input);
3973 return 1; /* syntax error */
3975 int ch = i_peek(input);
3976 dup_num = (ch == '-');
3977 if (dup_num) { /* <<-... */
3978 ch = i_getch(input);
3979 nommu_addchr(&ctx->as_string, ch);
3982 /* <<[-] word is the same as <<[-]word */
3983 while (ch == ' ' || ch == '\t') {
3984 ch = i_getch(input);
3985 nommu_addchr(&ctx->as_string, ch);
3990 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
3991 int ch = i_peek(input);
3993 /* >|FILE redirect ("clobbering" >).
3994 * Since we do not support "set -o noclobber" yet,
3995 * >| and > are the same for now. Just eat |.
3997 ch = i_getch(input);
3998 nommu_addchr(&ctx->as_string, ch);
4002 /* Create a new redir_struct and append it to the linked list */
4003 redirp = &command->redirects;
4004 while ((redir = *redirp) != NULL) {
4005 redirp = &(redir->next);
4007 *redirp = redir = xzalloc(sizeof(*redir));
4008 /* redir->next = NULL; */
4009 /* redir->rd_filename = NULL; */
4010 redir->rd_type = style;
4011 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4013 debug_printf_parse("redirect type %d %s\n", redir->rd_fd, redir_table[style].descrip);
4015 redir->rd_dup = dup_num;
4016 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4017 /* Erik had a check here that the file descriptor in question
4018 * is legit; I postpone that to "run time"
4019 * A "-" representation of "close me" shows up as a -3 here */
4020 debug_printf_parse("duplicating redirect '%d>&%d'\n", redir->rd_fd, redir->rd_dup);
4022 /* Set ctx->pending_redirect, so we know what to do at the
4023 * end of the next parsed word. */
4024 ctx->pending_redirect = redir;
4029 /* If a redirect is immediately preceded by a number, that number is
4030 * supposed to tell which file descriptor to redirect. This routine
4031 * looks for such preceding numbers. In an ideal world this routine
4032 * needs to handle all the following classes of redirects...
4033 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4034 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4035 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4036 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4038 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4040 * ... If n is quoted, the number shall not be recognized as part of
4041 * the redirection expression. For example:
4043 * writes the character 2 into file a"
4044 * I am not sure we do it right (and not sure we care)
4046 * A -1 return means no valid number was found,
4047 * the caller should use the appropriate default for this redirection.
4049 static int redirect_opt_num(o_string *o)
4053 if (o->data == NULL)
4055 num = bb_strtou(o->data, NULL, 10);
4056 if (errno || num < 0)
4063 #define fetch_till_str(as_string, input, word, skip_tabs) \
4064 fetch_till_str(input, word, skip_tabs)
4066 static char *fetch_till_str(o_string *as_string,
4067 struct in_str *input,
4071 o_string heredoc = NULL_O_STRING;
4077 ch = i_getch(input);
4078 nommu_addchr(as_string, ch);
4080 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4081 heredoc.data[past_EOL] = '\0';
4082 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4083 return heredoc.data;
4086 o_addchr(&heredoc, ch);
4087 past_EOL = heredoc.length;
4090 ch = i_getch(input);
4091 nommu_addchr(as_string, ch);
4092 } while (skip_tabs && ch == '\t');
4093 } while (ch == '\n');
4096 o_free_unsafe(&heredoc);
4099 o_addchr(&heredoc, ch);
4100 nommu_addchr(as_string, ch);
4104 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4106 struct pipe *pi = ctx->list_head;
4110 struct command *cmd = pi->cmds;
4112 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4114 cmd->argv ? cmd->argv[0] : "NONE");
4115 for (i = 0; i < pi->num_cmds; i++) {
4116 struct redir_struct *redir = cmd->redirects;
4118 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4119 i, cmd->argv ? cmd->argv[0] : "NONE");
4121 if (redir->rd_type == REDIRECT_HEREDOC) {
4124 if (heredoc_cnt <= 0)
4125 return 1; /* error */
4126 redir->rd_type = REDIRECT_HEREDOC2;
4127 /* redir->dup is (ab)used to indicate <<- */
4128 p = fetch_till_str(&ctx->as_string, input,
4129 redir->rd_filename, redir->rd_dup);
4131 return 1; /* unexpected EOF */
4132 free(redir->rd_filename);
4133 redir->rd_filename = p;
4136 redir = redir->next;
4142 /* Should be 0. If it isn't, it's a parse error */
4148 #define parse_stream(pstring, input, end_trigger) \
4149 parse_stream(input, end_trigger)
4151 static struct pipe *parse_stream(char **pstring,
4152 struct in_str *input,
4154 static void parse_and_run_string(const char *s);
4156 #if ENABLE_HUSH_TICK
4157 static FILE *generate_stream_from_string(const char *s)
4160 int pid, channel[2];
4163 pid = BB_MMU ? fork() : vfork();
4165 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4167 if (pid == 0) { /* child */
4168 disable_restore_tty_pgrp_on_exit();
4169 /* Process substitution is not considered to be usual
4170 * 'command execution'.
4171 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4178 close(channel[0]); /* NB: close _first_, then move fd! */
4179 xmove_fd(channel[1], 1);
4180 /* Prevent it from trying to handle ctrl-z etc */
4181 USE_HUSH_JOB(G.run_list_level = 1;)
4183 reset_traps_to_defaults();
4184 parse_and_run_string(s);
4185 _exit(G.last_exitcode);
4187 /* We re-execute after vfork on NOMMU. This makes this script safe:
4188 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4189 * huge=`cat BIG` # was blocking here forever
4192 re_execute_shell(s, 0);
4197 enable_restore_tty_pgrp_on_exit();
4198 clean_up_after_re_execute();
4200 pf = fdopen(channel[0], "r");
4204 /* Return code is exit status of the process that is run. */
4205 static int process_command_subs(o_string *dest, const char *s)
4208 struct in_str pipe_str;
4211 pf = generate_stream_from_string(s);
4214 close_on_exec_on(fileno(pf));
4216 /* Now send results of command back into original context */
4217 setup_file_in_str(&pipe_str, pf);
4219 while ((ch = i_getch(&pipe_str)) != EOF) {
4225 o_addchr(dest, '\n');
4228 o_addQchr(dest, ch);
4231 debug_printf("done reading from pipe, pclose()ing\n");
4232 /* Note: we got EOF, and we just close the read end of the pipe.
4233 * We do not wait for the `cmd` child to terminate. bash and ash do.
4235 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4236 * `false`; echo $? - bash outputs "1"
4239 debug_printf("closed FILE from child. return 0\n");
4244 static int parse_group(o_string *dest, struct parse_context *ctx,
4245 struct in_str *input, int ch)
4247 /* dest contains characters seen prior to ( or {.
4248 * Typically it's empty, but for function defs,
4249 * it contains function name (without '()'). */
4250 struct pipe *pipe_list;
4252 struct command *command = ctx->command;
4254 debug_printf_parse("parse_group entered\n");
4255 #if ENABLE_HUSH_FUNCTIONS
4256 if (ch == 'F') { /* function definition? */
4257 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4258 //command->fname = dest->data;
4259 command->grp_type = GRP_FUNCTION;
4260 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4261 memset(dest, 0, sizeof(*dest));
4264 if (command->argv /* word [word](... */
4265 || dest->length /* word(... */
4266 || dest->nonnull /* ""(... */
4269 debug_printf_parse("parse_group return 1: "
4270 "syntax error, groups and arglists don't mix\n");
4276 command->grp_type = GRP_SUBSHELL;
4280 char *as_string = NULL;
4282 pipe_list = parse_stream(&as_string, input, endch);
4285 o_addstr(&ctx->as_string, as_string);
4287 /* empty ()/{} or parse error? */
4288 if (!pipe_list || pipe_list == ERR_PTR) {
4293 debug_printf_parse("parse_group return 1: "
4294 "parse_stream returned %p\n", pipe_list);
4297 command->group = pipe_list;
4299 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4300 command->group_as_string = as_string;
4301 debug_printf_parse("end of group, remembering as:'%s'\n",
4302 command->group_as_string);
4305 debug_printf_parse("parse_group return 0\n");
4307 /* command remains "open", available for possible redirects */
4310 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4311 /* Subroutines for copying $(...) and `...` things */
4312 static void add_till_backquote(o_string *dest, struct in_str *input);
4314 static void add_till_single_quote(o_string *dest, struct in_str *input)
4317 int ch = i_getch(input);
4325 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4326 static void add_till_double_quote(o_string *dest, struct in_str *input)
4329 int ch = i_getch(input);
4332 if (ch == '\\') { /* \x. Copy both chars. */
4334 ch = i_getch(input);
4340 add_till_backquote(dest, input);
4344 //if (ch == '$') ...
4347 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4349 * "Within the backquoted style of command substitution, backslash
4350 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4351 * The search for the matching backquote shall be satisfied by the first
4352 * backquote found without a preceding backslash; during this search,
4353 * if a non-escaped backquote is encountered within a shell comment,
4354 * a here-document, an embedded command substitution of the $(command)
4355 * form, or a quoted string, undefined results occur. A single-quoted
4356 * or double-quoted string that begins, but does not end, within the
4357 * "`...`" sequence produces undefined results."
4359 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4361 static void add_till_backquote(o_string *dest, struct in_str *input)
4364 int ch = i_getch(input);
4367 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4368 int ch2 = i_getch(input);
4369 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4378 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4379 * quoting and nested ()s.
4380 * "With the $(command) style of command substitution, all characters
4381 * following the open parenthesis to the matching closing parenthesis
4382 * constitute the command. Any valid shell script can be used for command,
4383 * except a script consisting solely of redirections which produces
4384 * unspecified results."
4386 * echo $(echo '(TEST)' BEST) (TEST) BEST
4387 * echo $(echo 'TEST)' BEST) TEST) BEST
4388 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4390 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4394 int ch = i_getch(input);
4403 if (i_peek(input) == ')') {
4411 add_till_single_quote(dest, input);
4416 add_till_double_quote(dest, input);
4420 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4421 ch = i_getch(input);
4429 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4431 /* Return code: 0 for OK, 1 for syntax error */
4433 #define handle_dollar(as_string, dest, input) \
4434 handle_dollar(dest, input)
4436 static int handle_dollar(o_string *as_string,
4438 struct in_str *input)
4441 int ch = i_peek(input); /* first character after the $ */
4442 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4444 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4446 ch = i_getch(input);
4447 nommu_addchr(as_string, ch);
4449 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4451 debug_printf_parse(": '%c'\n", ch);
4452 o_addchr(dest, ch | quote_mask);
4455 if (!isalnum(ch) && ch != '_')
4457 ch = i_getch(input);
4458 nommu_addchr(as_string, ch);
4460 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4461 } else if (isdigit(ch)) {
4463 ch = i_getch(input);
4464 nommu_addchr(as_string, ch);
4465 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4466 debug_printf_parse(": '%c'\n", ch);
4467 o_addchr(dest, ch | quote_mask);
4468 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4469 } else switch (ch) {
4471 case '!': /* last bg pid */
4472 case '?': /* last exit code */
4473 case '#': /* number of args */
4474 case '*': /* args */
4475 case '@': /* args */
4476 goto make_one_char_var;
4478 bool first_char, all_digits;
4480 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4481 ch = i_getch(input);
4482 nommu_addchr(as_string, ch);
4483 /* XXX maybe someone will try to escape the '}' */
4488 ch = i_getch(input);
4489 nommu_addchr(as_string, ch);
4495 /* ${#var}: length of var contents */
4497 else if (isdigit(ch)) {
4504 && ( (all_digits && !isdigit(ch))
4505 || (!all_digits && !isalnum(ch) && ch != '_')
4508 /* handle parameter expansions
4509 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4514 case ':': /* null modifier */
4515 if (expansion == 0) {
4516 debug_printf_parse(": null modifier\n");
4521 case '#': /* remove prefix */
4522 case '%': /* remove suffix */
4523 if (expansion == 0) {
4524 debug_printf_parse(": remove suffix/prefix\n");
4529 case '-': /* default value */
4530 case '=': /* assign default */
4531 case '+': /* alternative */
4532 case '?': /* error indicate */
4533 debug_printf_parse(": parameter expansion\n");
4538 syntax("unterminated ${name}");
4539 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4544 debug_printf_parse(": '%c'\n", ch);
4545 o_addchr(dest, ch | quote_mask);
4549 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4552 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4557 ch = i_getch(input);
4558 nommu_addchr(as_string, ch);
4559 # if ENABLE_SH_MATH_SUPPORT
4560 if (i_peek(input) == '(') {
4561 ch = i_getch(input);
4562 nommu_addchr(as_string, ch);
4563 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4564 o_addchr(dest, /*quote_mask |*/ '+');
4568 add_till_closing_paren(dest, input, true);
4571 o_addstr(as_string, dest->data + pos);
4572 o_addchr(as_string, ')');
4573 o_addchr(as_string, ')');
4576 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4580 # if ENABLE_HUSH_TICK
4581 //int pos = dest->length;
4582 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4583 o_addchr(dest, quote_mask | '`');
4587 add_till_closing_paren(dest, input, false);
4590 o_addstr(as_string, dest->data + pos);
4591 o_addchr(as_string, '`');
4594 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4595 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4601 ch = i_getch(input);
4602 nommu_addchr(as_string, ch);
4604 if (isalnum(ch)) { /* it's $_name or $_123 */
4610 /* $_ Shell or shell script name; or last cmd name */
4611 /* $- Option flags set by set builtin or shell options (-i etc) */
4613 o_addQchr(dest, '$');
4615 debug_printf_parse("handle_dollar return 0\n");
4620 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4621 parse_stream_dquoted(dest, input, dquote_end)
4623 static int parse_stream_dquoted(o_string *as_string,
4625 struct in_str *input,
4632 ch = i_getch(input);
4634 nommu_addchr(as_string, ch);
4635 if (ch == dquote_end) { /* may be only '"' or EOF */
4637 if (dest->o_assignment == NOT_ASSIGNMENT)
4638 dest->o_escape ^= 1;
4639 debug_printf_parse("parse_stream_dquoted return 0\n");
4643 syntax("unterminated \"");
4644 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4649 next = i_peek(input);
4651 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4652 ch, ch, dest->o_escape);
4656 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4660 * "The backslash retains its special meaning [in "..."]
4661 * only when followed by one of the following characters:
4662 * $, `, ", \, or <newline>. A double quote may be quoted
4663 * within double quotes by preceding it with a backslash.
4664 * If enabled, history expansion will be performed unless
4665 * an ! appearing in double quotes is escaped using
4666 * a backslash. The backslash preceding the ! is not removed."
4668 if (strchr("$`\"\\", next) != NULL) {
4669 o_addqchr(dest, i_getch(input));
4671 o_addqchr(dest, '\\');
4676 if (handle_dollar(as_string, dest, input) != 0) {
4677 debug_printf_parse("parse_stream_dquoted return 1: "
4678 "handle_dollar returned non-0\n");
4683 #if ENABLE_HUSH_TICK
4685 //int pos = dest->length;
4686 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4687 o_addchr(dest, 0x80 | '`');
4688 add_till_backquote(dest, input);
4689 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4690 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4694 o_addQchr(dest, ch);
4696 && (dest->o_assignment == MAYBE_ASSIGNMENT
4697 || dest->o_assignment == WORD_IS_KEYWORD)
4698 && is_assignment(dest->data)
4700 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4706 * Scan input until EOF or end_trigger char.
4707 * Return a list of pipes to execute, or NULL on EOF
4708 * or if end_trigger character is met.
4709 * On syntax error, exit is shell is not interactive,
4710 * reset parsing machinery and start parsing anew,
4711 * or return ERR_PTR.
4713 static struct pipe *parse_stream(char **pstring,
4714 struct in_str *input,
4717 struct parse_context ctx;
4718 o_string dest = NULL_O_STRING;
4722 /* Double-quote state is handled in the state variable is_in_dquote.
4723 * A single-quote triggers a bypass of the main loop until its mate is
4724 * found. When recursing, quote state is passed in via dest->o_escape.
4726 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4727 end_trigger ? : 'X');
4729 G.ifs = get_local_var_value("IFS");
4734 #if ENABLE_HUSH_INTERACTIVE
4735 input->promptmode = 0; /* PS1 */
4737 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4738 initialize_context(&ctx);
4743 const char *is_special;
4747 redir_type redir_style;
4750 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4753 /* We reached closing '"' */
4756 ch = i_getch(input);
4757 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4758 ch, ch, dest.o_escape);
4763 syntax("unterminated here document");
4766 if (done_word(&dest, &ctx)) {
4770 done_pipe(&ctx, PIPE_SEQ);
4772 /* If we got nothing... */
4773 // TODO: test script consisting of just "&"
4774 if (pi->num_cmds == 0
4775 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4777 free_pipe_list(pi, 0);
4780 debug_printf_parse("parse_stream return %p\n", pi);
4782 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4784 *pstring = ctx.as_string.data;
4786 o_free_unsafe(&ctx.as_string);
4790 nommu_addchr(&ctx.as_string, ch);
4791 is_ifs = strchr(G.ifs, ch);
4792 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4793 "\\$\"" USE_HUSH_TICK("`") /* always special */
4796 if (!is_special && !is_ifs) { /* ordinary char */
4797 o_addQchr(&dest, ch);
4798 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4799 || dest.o_assignment == WORD_IS_KEYWORD)
4801 && is_assignment(dest.data)
4803 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4809 if (done_word(&dest, &ctx)) {
4813 #if ENABLE_HUSH_CASE
4814 /* "case ... in <newline> word) ..." -
4815 * newlines are ignored (but ';' wouldn't be) */
4816 if (ctx.command->argv == NULL
4817 && ctx.ctx_res_w == RES_MATCH
4822 /* Treat newline as a command separator. */
4823 done_pipe(&ctx, PIPE_SEQ);
4824 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4826 if (fetch_heredocs(heredoc_cnt, &ctx, input))
4830 dest.o_assignment = MAYBE_ASSIGNMENT;
4832 /* note: if (is_ifs) continue;
4833 * will still trigger for us */
4836 if (end_trigger && end_trigger == ch
4837 && (heredoc_cnt == 0 || end_trigger != ';')
4839 //TODO: disallow "{ cmd }" without semicolon
4841 /* This is technically valid:
4842 * { cat <<HERE; }; echo Ok
4847 * but we don't support this.
4848 * We require heredoc to be in enclosing {}/(),
4851 syntax("unterminated here document");
4854 if (done_word(&dest, &ctx)) {
4857 done_pipe(&ctx, PIPE_SEQ);
4858 dest.o_assignment = MAYBE_ASSIGNMENT;
4859 /* Do we sit outside of any if's, loops or case's? */
4861 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4863 debug_printf_parse("parse_stream return %p: "
4864 "end_trigger char found\n",
4868 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4870 *pstring = ctx.as_string.data;
4872 o_free_unsafe(&ctx.as_string);
4874 return ctx.list_head;
4880 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4881 /* ch is a special char and thus this word
4882 * cannot be an assignment */
4883 dest.o_assignment = NOT_ASSIGNMENT;
4888 next = i_peek(input);
4893 if (dest.length == 0) {
4896 if (ch == EOF || ch == '\n')
4899 /* note: we do not add it to &ctx.as_string */
4901 //TODO: go back one char?
4902 nommu_addchr(&ctx.as_string, '\n');
4904 o_addQchr(&dest, ch);
4912 o_addchr(&dest, '\\');
4913 ch = i_getch(input);
4914 o_addchr(&dest, ch);
4915 nommu_addchr(&ctx.as_string, ch);
4918 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
4919 debug_printf_parse("parse_stream parse error: "
4920 "handle_dollar returned non-0\n");
4927 ch = i_getch(input);
4929 syntax("unterminated '");
4932 nommu_addchr(&ctx.as_string, ch);
4935 if (dest.o_assignment == NOT_ASSIGNMENT)
4936 o_addqchr(&dest, ch);
4938 o_addchr(&dest, ch);
4943 is_in_dquote ^= 1; /* invert */
4944 if (dest.o_assignment == NOT_ASSIGNMENT)
4947 #if ENABLE_HUSH_TICK
4949 //int pos = dest.length;
4950 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4951 o_addchr(&dest, '`');
4952 add_till_backquote(&dest, input);
4953 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4954 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4959 redir_fd = redirect_opt_num(&dest);
4960 if (done_word(&dest, &ctx)) {
4963 redir_style = REDIRECT_OVERWRITE;
4965 redir_style = REDIRECT_APPEND;
4966 ch = i_getch(input);
4967 nommu_addchr(&ctx.as_string, ch);
4970 else if (next == '(') {
4971 syntax(">(process) not supported");
4975 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4979 redir_fd = redirect_opt_num(&dest);
4980 if (done_word(&dest, &ctx)) {
4983 redir_style = REDIRECT_INPUT;
4985 redir_style = REDIRECT_HEREDOC;
4987 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4988 ch = i_getch(input);
4989 nommu_addchr(&ctx.as_string, ch);
4990 } else if (next == '>') {
4991 redir_style = REDIRECT_IO;
4992 ch = i_getch(input);
4993 nommu_addchr(&ctx.as_string, ch);
4996 else if (next == '(') {
4997 syntax("<(process) not supported");
5001 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5005 #if ENABLE_HUSH_CASE
5008 if (done_word(&dest, &ctx)) {
5011 done_pipe(&ctx, PIPE_SEQ);
5012 #if ENABLE_HUSH_CASE
5013 /* Eat multiple semicolons, detect
5014 * whether it means something special */
5019 ch = i_getch(input);
5020 nommu_addchr(&ctx.as_string, ch);
5021 if (ctx.ctx_res_w == RES_CASEI) {
5022 ctx.ctx_dsemicolon = 1;
5023 ctx.ctx_res_w = RES_MATCH;
5029 /* We just finished a cmd. New one may start
5030 * with an assignment */
5031 dest.o_assignment = MAYBE_ASSIGNMENT;
5034 if (done_word(&dest, &ctx)) {
5038 ch = i_getch(input);
5039 nommu_addchr(&ctx.as_string, ch);
5040 done_pipe(&ctx, PIPE_AND);
5042 done_pipe(&ctx, PIPE_BG);
5046 if (done_word(&dest, &ctx)) {
5049 #if ENABLE_HUSH_CASE
5050 if (ctx.ctx_res_w == RES_MATCH)
5051 break; /* we are in case's "word | word)" */
5053 if (next == '|') { /* || */
5054 ch = i_getch(input);
5055 nommu_addchr(&ctx.as_string, ch);
5056 done_pipe(&ctx, PIPE_OR);
5058 /* we could pick up a file descriptor choice here
5059 * with redirect_opt_num(), but bash doesn't do it.
5060 * "echo foo 2| cat" yields "foo 2". */
5065 #if ENABLE_HUSH_CASE
5066 /* "case... in [(]word)..." - skip '(' */
5067 if (ctx.ctx_res_w == RES_MATCH
5068 && ctx.command->argv == NULL /* not (word|(... */
5069 && dest.length == 0 /* not word(... */
5070 && dest.nonnull == 0 /* not ""(... */
5075 #if ENABLE_HUSH_FUNCTIONS
5076 if (dest.length != 0 /* not just () but word() */
5077 && dest.nonnull == 0 /* not a"b"c() */
5078 && ctx.command->argv == NULL /* it's the first word */
5079 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5080 && i_peek(input) == ')'
5081 && !match_reserved_word(&dest)
5083 bb_error_msg("seems like a function definition");
5085 //if !BB_MMU o_addchr(&ctx.as_string...
5087 //TODO: do it properly.
5088 ch = i_getch(input);
5089 } while (ch == ' ' || ch == '\n');
5091 syntax("was expecting {");
5094 ch = 'F'; /* magic value */
5098 if (parse_group(&dest, &ctx, input, ch) != 0) {
5103 #if ENABLE_HUSH_CASE
5104 if (ctx.ctx_res_w == RES_MATCH)
5108 /* proper use of this character is caught by end_trigger:
5109 * if we see {, we call parse_group(..., end_trigger='}')
5110 * and it will match } earlier (not here). */
5111 syntax("unexpected } or )");
5115 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5121 struct parse_context *pctx;
5122 IF_HAS_KEYWORDS(struct parse_context *p2;)
5124 /* Clean up allocated tree.
5125 * Samples for finding leaks on syntax error recovery path.
5126 * Run them from interactive shell, watch pmap `pidof hush`.
5127 * while if false; then false; fi do break; done
5129 * while if false; then false; fi; do break; fi
5130 * Samples to catch leaks at execution:
5131 * while if (true | {true;}); then echo ok; fi; do break; done
5132 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5136 /* Update pipe/command counts,
5137 * otherwise freeing may miss some */
5138 done_pipe(pctx, PIPE_SEQ);
5139 debug_printf_clean("freeing list %p from ctx %p\n",
5140 pctx->list_head, pctx);
5141 debug_print_tree(pctx->list_head, 0);
5142 free_pipe_list(pctx->list_head, 0);
5143 debug_printf_clean("freed list %p\n", pctx->list_head);
5145 o_free_unsafe(&pctx->as_string);
5147 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5151 IF_HAS_KEYWORDS(pctx = p2;)
5152 } while (HAS_KEYWORDS && pctx);
5153 /* Free text, clear all dest fields */
5155 /* If we are not in top-level parse, we return,
5156 * our caller will propagate error.
5158 if (end_trigger != ';') {
5165 /* Discard cached input, force prompt */
5167 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5172 /* Executing from string: eval, sh -c '...'
5173 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5174 * end_trigger controls how often we stop parsing
5175 * NUL: parse all, execute, return
5176 * ';': parse till ';' or newline, execute, repeat till EOF
5178 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5181 struct pipe *pipe_list;
5183 pipe_list = parse_stream(NULL, inp, end_trigger);
5184 if (!pipe_list) /* EOF */
5186 debug_print_tree(pipe_list, 0);
5187 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5188 run_and_free_list(pipe_list);
5192 static void parse_and_run_string(const char *s)
5194 struct in_str input;
5195 setup_string_in_str(&input, s);
5196 parse_and_run_stream(&input, '\0');
5199 static void parse_and_run_file(FILE *f)
5201 struct in_str input;
5202 setup_file_in_str(&input, f);
5203 parse_and_run_stream(&input, ';');
5206 /* Called a few times only (or even once if "sh -c") */
5207 static void block_signals(int second_time)
5212 mask = (1 << SIGQUIT);
5213 if (G_interactive_fd) {
5217 //TODO | (1 << SIGHUP)
5219 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5224 G.non_DFL_mask = mask;
5227 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5231 sigaddset(&G.blocked_set, sig);
5235 sigdelset(&G.blocked_set, SIGCHLD);
5237 sigprocmask(SIG_SETMASK, &G.blocked_set,
5238 second_time ? NULL : &G.inherited_set);
5239 /* POSIX allows shell to re-enable SIGCHLD
5240 * even if it was SIG_IGN on entry */
5241 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5243 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5248 static void maybe_set_to_sigexit(int sig)
5250 void (*handler)(int);
5251 /* non_DFL_mask'ed signals are, well, masked,
5252 * no need to set handler for them.
5254 if (!((G.non_DFL_mask >> sig) & 1)) {
5255 handler = signal(sig, sigexit);
5256 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5257 signal(sig, handler);
5260 /* Set handlers to restore tty pgrp and exit */
5261 static void set_fatal_handlers(void)
5263 /* We _must_ restore tty pgrp on fatal signals */
5265 maybe_set_to_sigexit(SIGILL );
5266 maybe_set_to_sigexit(SIGFPE );
5267 maybe_set_to_sigexit(SIGBUS );
5268 maybe_set_to_sigexit(SIGSEGV);
5269 maybe_set_to_sigexit(SIGTRAP);
5270 } /* else: hush is perfect. what SEGV? */
5271 maybe_set_to_sigexit(SIGABRT);
5272 /* bash 3.2 seems to handle these just like 'fatal' ones */
5273 maybe_set_to_sigexit(SIGPIPE);
5274 maybe_set_to_sigexit(SIGALRM);
5275 //TODO: disable and move down when proper SIGHUP handling is added
5276 maybe_set_to_sigexit(SIGHUP );
5277 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5278 * if we aren't interactive... but in this case
5279 * we never want to restore pgrp on exit, and this fn is not called */
5280 /*maybe_set_to_sigexit(SIGTERM);*/
5281 /*maybe_set_to_sigexit(SIGINT );*/
5285 static int set_mode(const char cstate, const char mode)
5287 int state = (cstate == '-' ? 1 : 0);
5289 case 'n': G.fake_mode = state; break;
5290 case 'x': /*G.debug_mode = state;*/ break;
5291 default: return EXIT_FAILURE;
5293 return EXIT_SUCCESS;
5296 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5297 int hush_main(int argc, char **argv)
5299 static const struct variable const_shell_ver = {
5301 .varstr = (char*)hush_version_str,
5302 .max_len = 1, /* 0 can provoke free(name) */
5306 int signal_mask_is_inited = 0;
5309 struct variable *cur_var;
5312 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5313 G.last_exitcode = EXIT_SUCCESS;
5315 G.argv0_for_re_execing = argv[0];
5317 /* Deal with HUSH_VERSION */
5318 G.shell_ver = const_shell_ver; /* copying struct here */
5319 G.top_var = &G.shell_ver;
5320 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5321 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5322 /* Initialize our shell local variables with the values
5323 * currently living in the environment */
5324 cur_var = G.top_var;
5327 char *value = strchr(*e, '=');
5328 if (value) { /* paranoia */
5329 cur_var->next = xzalloc(sizeof(*cur_var));
5330 cur_var = cur_var->next;
5331 cur_var->varstr = *e;
5332 cur_var->max_len = strlen(*e);
5333 cur_var->flg_export = 1;
5337 debug_printf_env("putenv '%s'\n", hush_version_str);
5338 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5339 #if ENABLE_FEATURE_EDITING
5340 G.line_input_state = new_line_input_t(FOR_SHELL);
5342 G.global_argc = argc;
5343 G.global_argv = argv;
5344 /* Initialize some more globals to non-zero values */
5346 #if ENABLE_HUSH_INTERACTIVE
5347 if (ENABLE_FEATURE_EDITING)
5348 cmdedit_set_initial_prompt();
5352 /* Shell is non-interactive at first. We need to call
5353 * block_signals(0) if we are going to execute "sh <script>",
5354 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5355 * If we later decide that we are interactive, we run block_signals(0)
5356 * (or re-run block_signals(1) if we ran block_signals(0) before)
5357 * in order to intercept (more) signals.
5361 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5363 opt = getopt(argc, argv, "c:xins"
5373 G.root_pid = getpid();
5374 G.global_argv = argv + optind;
5375 if (!argv[optind]) {
5376 /* -c 'script' (no params): prevent empty $0 */
5377 *--G.global_argv = argv[0];
5379 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5380 G.global_argc = argc - optind;
5381 block_signals(0); /* 0: called 1st time */
5382 parse_and_run_string(optarg);
5385 /* Well, we cannot just declare interactiveness,
5386 * we have to have some stuff (ctty, etc) */
5387 /* G_interactive_fd++; */
5390 /* "-s" means "read from stdin", but this is how we always
5391 * operate, so simply do nothing here. */
5394 case '<': /* "big heredoc" support */
5395 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5398 G.root_pid = bb_strtou(optarg, &optarg, 16);
5400 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5402 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5403 # if ENABLE_HUSH_LOOPS
5405 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5410 set_local_var(xstrdup(optarg), 0, opt == 'R');
5415 if (!set_mode('-', opt))
5419 fprintf(stderr, "Usage: sh [FILE]...\n"
5420 " or: sh -c command [args]...\n\n");
5426 } /* option parsing loop */
5429 G.root_pid = getpid();
5431 /* If we are login shell... */
5432 if (argv[0] && argv[0][0] == '-') {
5434 /* XXX what should argv be while sourcing /etc/profile? */
5435 debug_printf("sourcing /etc/profile\n");
5436 input = fopen_for_read("/etc/profile");
5437 if (input != NULL) {
5438 close_on_exec_on(fileno(input));
5439 block_signals(0); /* 0: called 1st time */
5440 signal_mask_is_inited = 1;
5441 parse_and_run_file(input);
5444 /* bash: after sourcing /etc/profile,
5445 * tries to source (in the given order):
5446 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5447 * stopping of first found. --noprofile turns this off.
5448 * bash also sources ~/.bash_logout on exit.
5449 * If called as sh, skips .bash_XXX files.
5456 * "bash <script>" (which is never interactive (unless -i?))
5457 * sources $BASH_ENV here (without scanning $PATH).
5458 * If called as sh, does the same but with $ENV.
5460 debug_printf("running script '%s'\n", argv[optind]);
5461 G.global_argv = argv + optind;
5462 G.global_argc = argc - optind;
5463 input = xfopen_for_read(argv[optind]);
5464 close_on_exec_on(fileno(input));
5465 if (!signal_mask_is_inited)
5466 block_signals(0); /* 0: called 1st time */
5467 parse_and_run_file(input);
5468 #if ENABLE_FEATURE_CLEAN_UP
5474 /* Up to here, shell was non-interactive. Now it may become one.
5475 * NB: don't forget to (re)run block_signals(0/1) as needed.
5478 /* A shell is interactive if the '-i' flag was given, or if all of
5479 * the following conditions are met:
5481 * no arguments remaining or the -s flag given
5482 * standard input is a terminal
5483 * standard output is a terminal
5484 * Refer to Posix.2, the description of the 'sh' utility.
5487 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5488 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5489 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5490 //TODO: "interactive" and "have job control" are two different things.
5491 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5492 //should stay on! Currently, we mix these into one.
5493 if (G.saved_tty_pgrp >= 0) {
5494 /* try to dup stdin to high fd#, >= 255 */
5495 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5496 if (G_interactive_fd < 0) {
5497 /* try to dup to any fd */
5498 G_interactive_fd = dup(STDIN_FILENO);
5499 if (G_interactive_fd < 0)
5501 G_interactive_fd = 0;
5503 // TODO: track & disallow any attempts of user
5504 // to (inadvertently) close/redirect it
5507 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5508 if (G_interactive_fd) {
5511 /* We are indeed interactive shell, and we will perform
5512 * job control. Setting up for that. */
5514 close_on_exec_on(G_interactive_fd);
5515 /* If we were run as 'hush &', sleep until we are
5516 * in the foreground (tty pgrp == our pgrp).
5517 * If we get started under a job aware app (like bash),
5518 * make sure we are now in charge so we don't fight over
5519 * who gets the foreground */
5521 shell_pgrp = getpgrp();
5522 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5523 if (G.saved_tty_pgrp == shell_pgrp)
5525 /* send TTIN to ourself (should stop us) */
5526 kill(- shell_pgrp, SIGTTIN);
5528 /* Block some signals */
5529 block_signals(signal_mask_is_inited);
5530 /* Set other signals to restore saved_tty_pgrp */
5531 set_fatal_handlers();
5532 /* Put ourselves in our own process group */
5533 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5534 /* Grab control of the terminal */
5535 tcsetpgrp(G_interactive_fd, getpid());
5536 /* -1 is special - makes xfuncs longjmp, not exit
5537 * (we reset die_sleep = 0 whereever we [v]fork) */
5538 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5539 if (setjmp(die_jmp)) {
5540 /* xfunc has failed! die die die */
5541 hush_exit(xfunc_error_retval);
5543 } else if (!signal_mask_is_inited) {
5544 block_signals(0); /* 0: called 1st time */
5545 } /* else: block_signals(0) was done before */
5546 #elif ENABLE_HUSH_INTERACTIVE
5547 /* No job control compiled in, only prompt/line editing */
5548 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5549 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5550 if (G_interactive_fd < 0) {
5551 /* try to dup to any fd */
5552 G_interactive_fd = dup(STDIN_FILENO);
5553 if (G_interactive_fd < 0)
5555 G_interactive_fd = 0;
5558 if (G_interactive_fd) {
5559 close_on_exec_on(G_interactive_fd);
5560 block_signals(signal_mask_is_inited);
5561 } else if (!signal_mask_is_inited) {
5565 /* We have interactiveness code disabled */
5566 if (!signal_mask_is_inited) {
5571 * if interactive but not a login shell, sources ~/.bashrc
5572 * (--norc turns this off, --rcfile <file> overrides)
5575 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5576 printf("\n\n%s hush - the humble shell\n", bb_banner);
5577 printf("Enter 'help' for a list of built-in commands.\n\n");
5580 parse_and_run_file(stdin);
5583 #if ENABLE_FEATURE_CLEAN_UP
5584 if (G.cwd != bb_msg_unknown)
5586 cur_var = G.top_var->next;
5588 struct variable *tmp = cur_var;
5589 if (!cur_var->max_len)
5590 free(cur_var->varstr);
5591 cur_var = cur_var->next;
5595 hush_exit(G.last_exitcode);
5600 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5601 int lash_main(int argc, char **argv)
5603 //bb_error_msg("lash is deprecated, please use hush instead");
5604 return hush_main(argc, argv);
5612 static int builtin_trap(char **argv)
5619 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5623 /* No args: print all trapped. This isn't 100% correct as we
5624 * should be escaping the cmd so that it can be pasted back in
5626 for (i = 0; i < NSIG; ++i)
5628 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5629 return EXIT_SUCCESS;
5634 /* If first arg is decimal: reset all specified signals */
5635 sig = bb_strtou(*argv, NULL, 10);
5641 sig = get_signum(*argv++);
5642 if (sig < 0 || sig >= NSIG) {
5644 /* Mimic bash message exactly */
5645 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5650 G.traps[sig] = xstrdup(new_cmd);
5652 debug_printf("trap: setting SIG%s (%i) to '%s'",
5653 get_signame(sig), sig, G.traps[sig]);
5655 /* There is no signal for 0 (EXIT) */
5660 sigaddset(&G.blocked_set, sig);
5662 /* There was a trap handler, we are removing it
5663 * (if sig has non-DFL handling,
5664 * we don't need to do anything) */
5665 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5667 sigdelset(&G.blocked_set, sig);
5669 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5674 /* First arg is "-": reset all specified to default */
5675 /* First arg is "": ignore all specified */
5676 /* Everything else: execute first arg upon signal */
5678 bb_error_msg("trap: invalid arguments");
5679 return EXIT_FAILURE;
5681 if (NOT_LONE_DASH(*argv))
5687 static int builtin_true(char **argv UNUSED_PARAM)
5692 static int builtin_test(char **argv)
5699 return test_main(argc, argv - argc);
5702 static int builtin_echo(char **argv)
5709 return echo_main(argc, argv - argc);
5712 static int builtin_eval(char **argv)
5714 int rcode = EXIT_SUCCESS;
5717 char *str = expand_strvec_to_string(argv);
5719 * eval "echo Hi; done" ("done" is syntax error):
5720 * "echo Hi" will not execute too.
5722 parse_and_run_string(str);
5724 rcode = G.last_exitcode;
5729 static int builtin_cd(char **argv)
5731 const char *newdir = argv[1];
5732 if (newdir == NULL) {
5733 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5734 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5736 newdir = getenv("HOME") ? : "/";
5738 if (chdir(newdir)) {
5739 /* Mimic bash message exactly */
5740 bb_perror_msg("cd: %s", newdir);
5741 return EXIT_FAILURE;
5744 return EXIT_SUCCESS;
5747 static int builtin_exec(char **argv)
5749 if (*++argv == NULL)
5750 return EXIT_SUCCESS; /* bash does this */
5755 // FIXME: if exec fails, bash does NOT exit! We do...
5756 pseudo_exec_argv(&dummy, argv, 0, NULL);
5761 static int builtin_exit(char **argv)
5763 debug_printf_exec("%s()\n", __func__);
5764 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5765 //puts("exit"); /* bash does it */
5766 // TODO: warn if we have background jobs: "There are stopped jobs"
5767 // On second consecutive 'exit', exit anyway.
5768 if (*++argv == NULL)
5769 hush_exit(G.last_exitcode);
5770 /* mimic bash: exit 123abc == exit 255 + error msg */
5771 xfunc_error_retval = 255;
5772 /* bash: exit -2 == exit 254, no error msg */
5773 hush_exit(xatoi(*argv) & 0xff);
5776 static int builtin_export(char **argv)
5778 if (*++argv == NULL) {
5780 // ash emits: export VAR='VAL'
5781 // bash: declare -x VAR="VAL"
5782 // (both also escape as needed (quotes, $, etc))
5787 return EXIT_SUCCESS;
5794 value = strchr(name, '=');
5796 /* They are exporting something without a =VALUE */
5797 struct variable *var;
5799 var = get_local_var(name);
5801 var->flg_export = 1;
5802 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5803 putenv(var->varstr);
5805 /* bash does not return an error when trying to export
5806 * an undefined variable. Do likewise. */
5809 set_local_var(xstrdup(name), 1, 0);
5812 return EXIT_SUCCESS;
5816 /* built-in 'fg' and 'bg' handler */
5817 static int builtin_fg_bg(char **argv)
5822 if (!G_interactive_fd)
5823 return EXIT_FAILURE;
5824 /* If they gave us no args, assume they want the last backgrounded task */
5826 for (pi = G.job_list; pi; pi = pi->next) {
5827 if (pi->jobid == G.last_jobid) {
5831 bb_error_msg("%s: no current job", argv[0]);
5832 return EXIT_FAILURE;
5834 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5835 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5836 return EXIT_FAILURE;
5838 for (pi = G.job_list; pi; pi = pi->next) {
5839 if (pi->jobid == jobnum) {
5843 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5844 return EXIT_FAILURE;
5846 // TODO: bash prints a string representation
5847 // of job being foregrounded (like "sleep 1 | cat")
5848 if (argv[0][0] == 'f') {
5849 /* Put the job into the foreground. */
5850 tcsetpgrp(G_interactive_fd, pi->pgrp);
5853 /* Restart the processes in the job */
5854 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5855 for (i = 0; i < pi->num_cmds; i++) {
5856 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5857 pi->cmds[i].is_stopped = 0;
5859 pi->stopped_cmds = 0;
5861 i = kill(- pi->pgrp, SIGCONT);
5863 if (errno == ESRCH) {
5864 delete_finished_bg_job(pi);
5865 return EXIT_SUCCESS;
5867 bb_perror_msg("kill (SIGCONT)");
5870 if (argv[0][0] == 'f') {
5872 return checkjobs_and_fg_shell(pi);
5874 return EXIT_SUCCESS;
5878 #if ENABLE_HUSH_HELP
5879 static int builtin_help(char **argv UNUSED_PARAM)
5881 const struct built_in_command *x;
5884 "Built-in commands:\n"
5885 "------------------\n");
5886 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5887 printf("%s\t%s\n", x->cmd, x->descr);
5890 return EXIT_SUCCESS;
5895 static int builtin_jobs(char **argv UNUSED_PARAM)
5898 const char *status_string;
5900 for (job = G.job_list; job; job = job->next) {
5901 if (job->alive_cmds == job->stopped_cmds)
5902 status_string = "Stopped";
5904 status_string = "Running";
5906 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5908 return EXIT_SUCCESS;
5912 static int builtin_pwd(char **argv UNUSED_PARAM)
5915 return EXIT_SUCCESS;
5918 static int builtin_read(char **argv)
5921 const char *name = argv[1] ? argv[1] : "REPLY";
5922 //TODO: check that argv[1] is a valid variable name
5924 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5925 return set_local_var(string, 0, 0);
5928 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5929 * built-in 'set' handler
5931 * set [-abCefhmnuvx] [-o option] [argument...]
5932 * set [+abCefhmnuvx] [+o option] [argument...]
5933 * set -- [argument...]
5936 * Implementations shall support the options in both their hyphen and
5937 * plus-sign forms. These options can also be specified as options to sh.
5939 * Write out all variables and their values: set
5940 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5941 * Turn on the -x and -v options: set -xv
5942 * Unset all positional parameters: set --
5943 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5944 * Set the positional parameters to the expansion of x, even if x expands
5945 * with a leading '-' or '+': set -- $x
5947 * So far, we only support "set -- [argument...]" and some of the short names.
5949 static int builtin_set(char **argv)
5952 char **pp, **g_argv;
5953 char *arg = *++argv;
5957 for (e = G.top_var; e; e = e->next)
5959 return EXIT_SUCCESS;
5963 if (!strcmp(arg, "--")) {
5968 if (arg[0] == '+' || arg[0] == '-') {
5969 for (n = 1; arg[n]; ++n)
5970 if (set_mode(arg[0], arg[n]))
5976 } while ((arg = *++argv) != NULL);
5977 /* Now argv[0] is 1st argument */
5979 /* Only reset global_argv if we didn't process anything */
5981 return EXIT_SUCCESS;
5984 /* NB: G.global_argv[0] ($0) is never freed/changed */
5985 g_argv = G.global_argv;
5986 if (G.global_args_malloced) {
5992 G.global_args_malloced = 1;
5993 pp = xzalloc(sizeof(pp[0]) * 2);
5994 pp[0] = g_argv[0]; /* retain $0 */
5997 /* This realloc's G.global_argv */
5998 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6005 return EXIT_SUCCESS;
6007 /* Nothing known, so abort */
6009 bb_error_msg("set: %s: invalid option", arg);
6010 return EXIT_FAILURE;
6013 static int builtin_shift(char **argv)
6019 if (n >= 0 && n < G.global_argc) {
6020 if (G.global_args_malloced) {
6023 free(G.global_argv[m++]);
6026 memmove(&G.global_argv[1], &G.global_argv[n+1],
6027 G.global_argc * sizeof(G.global_argv[0]));
6028 return EXIT_SUCCESS;
6030 return EXIT_FAILURE;
6033 static int builtin_source(char **argv)
6037 if (*++argv == NULL)
6038 return EXIT_FAILURE;
6040 /* XXX search through $PATH is missing */
6041 input = fopen_or_warn(*argv, "r");
6043 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6044 return EXIT_FAILURE;
6046 close_on_exec_on(fileno(input));
6048 /* Now run the file */
6050 /* XXX argv and argc are broken; need to save old G.global_argv
6051 * (pointer only is OK!) on this stack frame,
6052 * set G.global_argv=argv+1, recurse, and restore. */
6053 parse_and_run_file(input);
6055 return G.last_exitcode;
6058 static int builtin_umask(char **argv)
6061 const char *arg = argv[1];
6063 //TODO: umask may take chmod-like symbolic masks
6064 new_umask = bb_strtou(arg, NULL, 8);
6066 //Message? bash examples:
6067 //bash: umask: 'q': invalid symbolic mode operator
6068 //bash: umask: 999: octal number out of range
6069 return EXIT_FAILURE;
6072 new_umask = umask(0);
6073 printf("%.3o\n", (unsigned) new_umask);
6074 /* fall through and restore new_umask which we set to 0 */
6077 return EXIT_SUCCESS;
6080 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6081 static int builtin_unset(char **argv)
6087 return EXIT_SUCCESS;
6090 if (argv[0][0] == '-') {
6091 switch (argv[0][1]) {
6097 bb_error_msg("unset: %s: invalid option", *argv);
6098 return EXIT_FAILURE;
6100 //TODO: disallow "unset -vf ..." too
6107 if (unset_local_var(*argv)) {
6108 /* unset <nonexistent_var> doesn't fail.
6109 * Error is when one tries to unset RO var.
6110 * Message was printed by unset_local_var. */
6114 #if ENABLE_HUSH_FUNCTIONS
6116 unset_local_func(*argv);
6124 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6125 static int builtin_wait(char **argv)
6127 int ret = EXIT_SUCCESS;
6130 if (*++argv == NULL) {
6131 /* Don't care about wait results */
6132 /* Note 1: must wait until there are no more children */
6133 /* Note 2: must be interruptible */
6135 * $ sleep 3 & sleep 6 & wait
6140 * $ sleep 3 & sleep 6 & wait
6144 * ^C <-- after ~4 sec from keyboard
6147 sigaddset(&G.blocked_set, SIGCHLD);
6148 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6151 if (errno == ECHILD)
6153 /* Wait for SIGCHLD or any other signal of interest */
6154 /* sigtimedwait with infinite timeout: */
6155 sig = sigwaitinfo(&G.blocked_set, NULL);
6157 sig = check_and_run_traps(sig);
6158 if (sig && sig != SIGCHLD) { /* see note 2 */
6164 sigdelset(&G.blocked_set, SIGCHLD);
6165 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6169 /* This is probably buggy wrt interruptible-ness */
6171 pid_t pid = bb_strtou(*argv, NULL, 10);
6173 /* mimic bash message */
6174 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6175 return EXIT_FAILURE;
6177 if (waitpid(pid, &status, 0) == pid) {
6178 if (WIFSIGNALED(status))
6179 ret = 128 + WTERMSIG(status);
6180 else if (WIFEXITED(status))
6181 ret = WEXITSTATUS(status);
6185 bb_perror_msg("wait %s", *argv);
6194 #if ENABLE_HUSH_LOOPS
6195 static int builtin_break(char **argv)
6197 if (G.depth_of_loop == 0) {
6198 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6199 return EXIT_SUCCESS; /* bash compat */
6201 G.flag_break_continue++; /* BC_BREAK = 1 */
6202 G.depth_break_continue = 1;
6204 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6205 if (errno || !G.depth_break_continue || argv[2]) {
6206 bb_error_msg("%s: bad arguments", argv[0]);
6207 G.flag_break_continue = BC_BREAK;
6208 G.depth_break_continue = UINT_MAX;
6211 if (G.depth_of_loop < G.depth_break_continue)
6212 G.depth_break_continue = G.depth_of_loop;
6213 return EXIT_SUCCESS;
6216 static int builtin_continue(char **argv)
6218 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6219 return builtin_break(argv);