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 */
918 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
919 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
920 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
921 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
923 /* Restores tty foreground process group, and exits.
924 * May be called as signal handler for fatal signal
925 * (will faithfully resend signal to itself, producing correct exit state)
926 * or called directly with -EXITCODE.
927 * We also call it if xfunc is exiting. */
928 static void sigexit(int sig) NORETURN;
929 static void sigexit(int sig)
931 /* Disable all signals: job control, SIGPIPE, etc. */
932 sigprocmask_allsigs(SIG_BLOCK);
934 /* Careful: we can end up here after [v]fork. Do not restore
935 * tty pgrp then, only top-level shell process does that */
936 if (G_interactive_fd && getpid() == G.root_pid)
937 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
939 /* Not a signal, just exit */
943 kill_myself_with_sig(sig); /* does not return */
947 #define disable_restore_tty_pgrp_on_exit() ((void)0)
948 #define enable_restore_tty_pgrp_on_exit() ((void)0)
952 /* Restores tty foreground process group, and exits. */
953 static void hush_exit(int exitcode) NORETURN;
954 static void hush_exit(int exitcode)
956 if (G.traps && G.traps[0] && G.traps[0][0]) {
957 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
958 //TODO: do we need to prevent recursion?
964 fflush(NULL); /* flush all streams */
965 sigexit(- (exitcode & 0xff));
972 static const char *set_cwd(void)
974 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
975 * we must not try to free(bb_msg_unknown) */
976 if (G.cwd == bb_msg_unknown)
978 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
980 G.cwd = bb_msg_unknown;
985 /* Get/check local shell variables */
986 static struct variable *get_local_var(const char *name)
988 struct variable *cur;
994 for (cur = G.top_var; cur; cur = cur->next) {
995 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1001 static const char *get_local_var_value(const char *src)
1003 struct variable *var = get_local_var(src);
1005 return strchr(var->varstr, '=') + 1;
1009 /* str holds "NAME=VAL" and is expected to be malloced.
1010 * We take ownership of it.
1014 * -1: if NAME is set, leave export status alone
1015 * if NAME is not set, do not export
1016 * flg_read_only is set only when we handle -R var=val
1019 #define set_local_var(str, flg_export, flg_read_only) \
1020 set_local_var(str, flg_export)
1022 static int set_local_var(char *str, int flg_export, int flg_read_only)
1024 struct variable *cur;
1028 value = strchr(str, '=');
1029 if (!value) { /* not expected to ever happen? */
1034 name_len = value - str + 1; /* including '=' */
1035 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1037 if (strncmp(cur->varstr, str, name_len) != 0) {
1039 /* Bail out. Note that now cur points
1040 * to last var in linked list */
1046 /* We found an existing var with this name */
1048 if (cur->flg_read_only) {
1052 bb_error_msg("%s: readonly variable", str);
1056 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1057 unsetenv(str); /* just in case */
1059 if (strcmp(cur->varstr, str) == 0) {
1064 if (cur->max_len >= strlen(str)) {
1065 /* This one is from startup env, reuse space */
1066 strcpy(cur->varstr, str);
1069 /* max_len == 0 signifies "malloced" var, which we can
1070 * (and has to) free */
1074 goto set_str_and_exp;
1077 /* Not found - create next variable struct */
1078 cur->next = xzalloc(sizeof(*cur));
1084 cur->flg_read_only = flg_read_only;
1087 if (flg_export == 1)
1088 cur->flg_export = 1;
1089 if (cur->flg_export) {
1090 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1091 return putenv(cur->varstr);
1096 static int unset_local_var(const char *name)
1098 struct variable *cur;
1099 struct variable *prev = prev; /* for gcc */
1103 return EXIT_SUCCESS;
1104 name_len = strlen(name);
1107 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1108 if (cur->flg_read_only) {
1109 bb_error_msg("%s: readonly variable", name);
1110 return EXIT_FAILURE;
1112 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1113 * is ro, and we cannot reach this code on the 1st pass */
1114 prev->next = cur->next;
1115 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1116 bb_unsetenv(cur->varstr);
1120 return EXIT_SUCCESS;
1125 return EXIT_SUCCESS;
1128 #if ENABLE_SH_MATH_SUPPORT
1129 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1130 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1131 static char *endofname(const char *name)
1139 if (!is_in_name(*p))
1145 static void arith_set_local_var(const char *name, const char *val, int flags)
1147 /* arith code doesnt malloc space, so do it for it */
1148 char *var = xasprintf("%s=%s", name, val);
1149 set_local_var(var, flags, 0);
1157 static int static_get(struct in_str *i)
1166 static int static_peek(struct in_str *i)
1171 #if ENABLE_HUSH_INTERACTIVE
1173 static void cmdedit_set_initial_prompt(void)
1175 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1176 G.PS1 = getenv("PS1");
1183 static const char* setup_prompt_string(int promptmode)
1185 const char *prompt_str;
1186 debug_printf("setup_prompt_string %d ", promptmode);
1187 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1188 /* Set up the prompt */
1189 if (promptmode == 0) { /* PS1 */
1191 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1196 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1197 debug_printf("result '%s'\n", prompt_str);
1201 static void get_user_input(struct in_str *i)
1204 const char *prompt_str;
1206 prompt_str = setup_prompt_string(i->promptmode);
1207 #if ENABLE_FEATURE_EDITING
1208 /* Enable command line editing only while a command line
1209 * is actually being read */
1212 /* buglet: SIGINT will not make new prompt to appear _at once_,
1213 * only after <Enter>. (^C will work) */
1214 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1215 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1216 check_and_run_traps(0);
1217 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1218 i->eof_flag = (r < 0);
1219 if (i->eof_flag) { /* EOF/error detected */
1220 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1221 G.user_input_buf[1] = '\0';
1226 fputs(prompt_str, stdout);
1228 G.user_input_buf[0] = r = fgetc(i->file);
1229 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1230 //do we need check_and_run_traps(0)? (maybe only if stdin)
1231 } while (G.flag_SIGINT);
1232 i->eof_flag = (r == EOF);
1234 i->p = G.user_input_buf;
1237 #endif /* INTERACTIVE */
1239 /* This is the magic location that prints prompts
1240 * and gets data back from the user */
1241 static int file_get(struct in_str *i)
1245 /* If there is data waiting, eat it up */
1246 if (i->p && *i->p) {
1247 #if ENABLE_HUSH_INTERACTIVE
1251 if (i->eof_flag && !*i->p)
1253 /* note: ch is never NUL */
1255 /* need to double check i->file because we might be doing something
1256 * more complicated by now, like sourcing or substituting. */
1257 #if ENABLE_HUSH_INTERACTIVE
1258 if (G_interactive_fd && i->promptme && i->file == stdin) {
1261 } while (!*i->p); /* need non-empty line */
1262 i->promptmode = 1; /* PS2 */
1267 do ch = fgetc(i->file); while (ch == '\0');
1269 debug_printf("file_get: got '%c' %d\n", ch, ch);
1270 #if ENABLE_HUSH_INTERACTIVE
1277 /* All callers guarantee this routine will never
1278 * be used right after a newline, so prompting is not needed.
1280 static int file_peek(struct in_str *i)
1283 if (i->p && *i->p) {
1284 if (i->eof_flag && !i->p[1])
1287 /* note: ch is never NUL */
1289 do ch = fgetc(i->file); while (ch == '\0');
1290 i->eof_flag = (ch == EOF);
1291 i->peek_buf[0] = ch;
1292 i->peek_buf[1] = '\0';
1294 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1298 static void setup_file_in_str(struct in_str *i, FILE *f)
1300 i->peek = file_peek;
1302 #if ENABLE_HUSH_INTERACTIVE
1304 i->promptmode = 0; /* PS1 */
1310 static void setup_string_in_str(struct in_str *i, const char *s)
1312 i->peek = static_peek;
1313 i->get = static_get;
1314 #if ENABLE_HUSH_INTERACTIVE
1316 i->promptmode = 0; /* PS1 */
1326 #define B_CHUNK (32 * sizeof(char*))
1328 static void o_reset(o_string *o)
1336 static void o_free(o_string *o)
1339 memset(o, 0, sizeof(*o));
1342 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1347 static void o_grow_by(o_string *o, int len)
1349 if (o->length + len > o->maxlen) {
1350 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1351 o->data = xrealloc(o->data, 1 + o->maxlen);
1355 static void o_addchr(o_string *o, int ch)
1357 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1359 o->data[o->length] = ch;
1361 o->data[o->length] = '\0';
1364 static void o_addblock(o_string *o, const char *str, int len)
1367 memcpy(&o->data[o->length], str, len);
1369 o->data[o->length] = '\0';
1373 static void o_addstr(o_string *o, const char *str)
1375 o_addblock(o, str, strlen(str));
1377 static void nommu_addchr(o_string *o, int ch)
1383 #define nommu_addchr(o, str) ((void)0)
1386 static void o_addstr_with_NUL(o_string *o, const char *str)
1388 o_addblock(o, str, strlen(str) + 1);
1391 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1396 && (*str != '*' && *str != '?' && *str != '[')
1404 /* My analysis of quoting semantics tells me that state information
1405 * is associated with a destination, not a source.
1407 static void o_addqchr(o_string *o, int ch)
1410 char *found = strchr("*?[\\", ch);
1415 o->data[o->length] = '\\';
1418 o->data[o->length] = ch;
1420 o->data[o->length] = '\0';
1423 static void o_addQchr(o_string *o, int ch)
1426 if (o->o_escape && strchr("*?[\\", ch)) {
1428 o->data[o->length] = '\\';
1432 o->data[o->length] = ch;
1434 o->data[o->length] = '\0';
1437 static void o_addQstr(o_string *o, const char *str, int len)
1440 o_addblock(o, str, len);
1446 int ordinary_cnt = strcspn(str, "*?[\\");
1447 if (ordinary_cnt > len) /* paranoia */
1449 o_addblock(o, str, ordinary_cnt);
1450 if (ordinary_cnt == len)
1452 str += ordinary_cnt;
1453 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1457 if (ch) { /* it is necessarily one of "*?[\\" */
1459 o->data[o->length] = '\\';
1463 o->data[o->length] = ch;
1465 o->data[o->length] = '\0';
1469 /* A special kind of o_string for $VAR and `cmd` expansion.
1470 * It contains char* list[] at the beginning, which is grown in 16 element
1471 * increments. Actual string data starts at the next multiple of 16 * (char*).
1472 * list[i] contains an INDEX (int!) into this string data.
1473 * It means that if list[] needs to grow, data needs to be moved higher up
1474 * but list[i]'s need not be modified.
1475 * NB: remembering how many list[i]'s you have there is crucial.
1476 * o_finalize_list() operation post-processes this structure - calculates
1477 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1479 #if DEBUG_EXPAND || DEBUG_GLOB
1480 static void debug_print_list(const char *prefix, o_string *o, int n)
1482 char **list = (char**)o->data;
1483 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1485 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1486 prefix, list, n, string_start, o->length, o->maxlen);
1488 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1489 o->data + (int)list[i] + string_start,
1490 o->data + (int)list[i] + string_start);
1494 const char *p = o->data + (int)list[n - 1] + string_start;
1495 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1499 #define debug_print_list(prefix, o, n) ((void)0)
1502 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1503 * in list[n] so that it points past last stored byte so far.
1504 * It returns n+1. */
1505 static int o_save_ptr_helper(o_string *o, int n)
1507 char **list = (char**)o->data;
1511 if (!o->has_empty_slot) {
1512 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1513 string_len = o->length - string_start;
1514 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1515 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1516 /* list[n] points to string_start, make space for 16 more pointers */
1517 o->maxlen += 0x10 * sizeof(list[0]);
1518 o->data = xrealloc(o->data, o->maxlen + 1);
1519 list = (char**)o->data;
1520 memmove(list + n + 0x10, list + n, string_len);
1521 o->length += 0x10 * sizeof(list[0]);
1523 debug_printf_list("list[%d]=%d string_start=%d\n",
1524 n, string_len, string_start);
1527 /* We have empty slot at list[n], reuse without growth */
1528 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1529 string_len = o->length - string_start;
1530 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1531 n, string_len, string_start);
1532 o->has_empty_slot = 0;
1534 list[n] = (char*)(ptrdiff_t)string_len;
1538 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1539 static int o_get_last_ptr(o_string *o, int n)
1541 char **list = (char**)o->data;
1542 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1544 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1547 /* o_glob performs globbing on last list[], saving each result
1548 * as a new list[]. */
1549 static int o_glob(o_string *o, int n)
1555 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1557 return o_save_ptr_helper(o, n);
1558 pattern = o->data + o_get_last_ptr(o, n);
1559 debug_printf_glob("glob pattern '%s'\n", pattern);
1560 if (!glob_needed(pattern)) {
1562 o->length = unbackslash(pattern) - o->data;
1563 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1564 return o_save_ptr_helper(o, n);
1567 memset(&globdata, 0, sizeof(globdata));
1568 gr = glob(pattern, 0, NULL, &globdata);
1569 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1570 if (gr == GLOB_NOSPACE)
1571 bb_error_msg_and_die("out of memory during glob");
1572 if (gr == GLOB_NOMATCH) {
1573 globfree(&globdata);
1576 if (gr != 0) { /* GLOB_ABORTED ? */
1577 //TODO: testcase for bad glob pattern behavior
1578 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1580 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1581 char **argv = globdata.gl_pathv;
1582 o->length = pattern - o->data; /* "forget" pattern */
1584 o_addstr_with_NUL(o, *argv);
1585 n = o_save_ptr_helper(o, n);
1591 globfree(&globdata);
1593 debug_print_list("o_glob returning", o, n);
1597 /* If o->o_glob == 1, glob the string so far remembered.
1598 * Otherwise, just finish current list[] and start new */
1599 static int o_save_ptr(o_string *o, int n)
1601 if (o->o_glob) { /* if globbing is requested */
1602 /* If o->has_empty_slot, list[n] was already globbed
1603 * (if it was requested back then when it was filled)
1604 * so don't do that again! */
1605 if (!o->has_empty_slot)
1606 return o_glob(o, n); /* o_save_ptr_helper is inside */
1608 return o_save_ptr_helper(o, n);
1611 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1612 static char **o_finalize_list(o_string *o, int n)
1617 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1619 debug_print_list("finalized", o, n);
1620 debug_printf_expand("finalized n:%d\n", n);
1621 list = (char**)o->data;
1622 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1626 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1632 /* Expansion can recurse */
1633 #if ENABLE_HUSH_TICK
1634 static int process_command_subs(o_string *dest, const char *s);
1636 static char *expand_string_to_string(const char *str);
1638 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1639 parse_stream_dquoted(dest, input, dquote_end)
1641 static int parse_stream_dquoted(o_string *as_string,
1643 struct in_str *input,
1646 /* expand_strvec_to_strvec() takes a list of strings, expands
1647 * all variable references within and returns a pointer to
1648 * a list of expanded strings, possibly with larger number
1649 * of strings. (Think VAR="a b"; echo $VAR).
1650 * This new list is allocated as a single malloc block.
1651 * NULL-terminated list of char* pointers is at the beginning of it,
1652 * followed by strings themself.
1653 * Caller can deallocate entire list by single free(list). */
1655 /* Store given string, finalizing the word and starting new one whenever
1656 * we encounter IFS char(s). This is used for expanding variable values.
1657 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1658 static int expand_on_ifs(o_string *output, int n, const char *str)
1661 int word_len = strcspn(str, G.ifs);
1663 if (output->o_escape || !output->o_glob)
1664 o_addQstr(output, str, word_len);
1665 else /* protect backslashes against globbing up :) */
1666 o_addblock_duplicate_backslash(output, str, word_len);
1669 if (!*str) /* EOL - do not finalize word */
1671 o_addchr(output, '\0');
1672 debug_print_list("expand_on_ifs", output, n);
1673 n = o_save_ptr(output, n);
1674 str += strspn(str, G.ifs); /* skip ifs chars */
1676 debug_print_list("expand_on_ifs[1]", output, n);
1680 /* Expand all variable references in given string, adding words to list[]
1681 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1682 * to be filled). This routine is extremely tricky: has to deal with
1683 * variables/parameters with whitespace, $* and $@, and constructs like
1684 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1685 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1687 /* or_mask is either 0 (normal case) or 0x80
1688 * (expansion of right-hand side of assignment == 1-element expand.
1689 * It will also do no globbing, and thus we must not backslash-quote!) */
1691 char first_ch, ored_ch;
1699 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1700 debug_print_list("expand_vars_to_list", output, n);
1701 n = o_save_ptr(output, n);
1702 debug_print_list("expand_vars_to_list[0]", output, n);
1704 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1705 #if ENABLE_HUSH_TICK
1706 o_string subst_result = NULL_O_STRING;
1708 #if ENABLE_SH_MATH_SUPPORT
1709 char arith_buf[sizeof(arith_t)*3 + 2];
1711 o_addblock(output, arg, p - arg);
1712 debug_print_list("expand_vars_to_list[1]", output, n);
1714 p = strchr(p, SPECIAL_VAR_SYMBOL);
1716 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1717 /* "$@" is special. Even if quoted, it can still
1718 * expand to nothing (not even an empty string) */
1719 if ((first_ch & 0x7f) != '@')
1720 ored_ch |= first_ch;
1723 switch (first_ch & 0x7f) {
1724 /* Highest bit in first_ch indicates that var is double-quoted */
1726 val = utoa(G.root_pid);
1728 case '!': /* bg pid */
1729 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1731 case '?': /* exitcode */
1732 val = utoa(G.last_exitcode);
1734 case '#': /* argc */
1735 if (arg[1] != SPECIAL_VAR_SYMBOL)
1736 /* actually, it's a ${#var} */
1738 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1743 if (!G.global_argv[i])
1745 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1746 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1747 smallint sv = output->o_escape;
1748 /* unquoted var's contents should be globbed, so don't escape */
1749 output->o_escape = 0;
1750 while (G.global_argv[i]) {
1751 n = expand_on_ifs(output, n, G.global_argv[i]);
1752 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1753 if (G.global_argv[i++][0] && G.global_argv[i]) {
1754 /* this argv[] is not empty and not last:
1755 * put terminating NUL, start new word */
1756 o_addchr(output, '\0');
1757 debug_print_list("expand_vars_to_list[2]", output, n);
1758 n = o_save_ptr(output, n);
1759 debug_print_list("expand_vars_to_list[3]", output, n);
1762 output->o_escape = sv;
1764 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1765 * and in this case should treat it like '$*' - see 'else...' below */
1766 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1768 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1769 if (++i >= G.global_argc)
1771 o_addchr(output, '\0');
1772 debug_print_list("expand_vars_to_list[4]", output, n);
1773 n = o_save_ptr(output, n);
1775 } else { /* quoted $*: add as one word */
1777 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1778 if (!G.global_argv[++i])
1781 o_addchr(output, G.ifs[0]);
1785 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1786 /* "Empty variable", used to make "" etc to not disappear */
1790 #if ENABLE_HUSH_TICK
1791 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1794 //TODO: can we just stuff it into "output" directly?
1795 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1796 process_command_subs(&subst_result, arg);
1797 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1798 val = subst_result.data;
1801 #if ENABLE_SH_MATH_SUPPORT
1802 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1803 arith_eval_hooks_t hooks;
1808 arg++; /* skip '+' */
1809 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1810 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1812 /* Optional: skip expansion if expr is simple ("a + 3", "i++" etc) */
1814 if (strchr(arg, '$') != NULL
1815 #if ENABLE_HUSH_TICK
1816 || strchr(arg, '`') != NULL
1819 /* We need to expand. Example:
1820 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1822 struct in_str input;
1823 o_string dest = NULL_O_STRING;
1825 setup_string_in_str(&input, arg);
1826 parse_stream_dquoted(NULL, &dest, &input, EOF);
1827 //bb_error_msg("'%s' -> '%s'", arg, dest.data);
1828 exp_str = expand_string_to_string(dest.data);
1829 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1830 o_free_unsafe(&dest);
1832 hooks.lookupvar = get_local_var_value;
1833 hooks.setvar = arith_set_local_var;
1834 hooks.endofname = endofname;
1835 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1840 case -3: maybe_die("arith", "exponent less than 0"); break;
1841 case -2: maybe_die("arith", "divide by zero"); break;
1842 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1843 default: maybe_die("arith", "syntax error"); break;
1846 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1847 sprintf(arith_buf, arith_t_fmt, res);
1852 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1854 bool exp_len = false;
1855 bool exp_null = false;
1857 char exp_save = exp_save; /* for compiler */
1858 char exp_op = exp_op; /* for compiler */
1859 char *exp_word = exp_word; /* for compiler */
1863 arg[0] = first_ch & 0x7f;
1865 /* prepare for expansions */
1866 if (var[0] == '#') {
1867 /* handle length expansion ${#var} */
1871 /* maybe handle parameter expansion */
1872 exp_off = strcspn(var, ":-=+?%#");
1876 exp_save = var[exp_off];
1877 exp_null = exp_save == ':';
1878 exp_word = var + exp_off;
1879 if (exp_null) ++exp_word;
1880 exp_op = *exp_word++;
1881 var[exp_off] = '\0';
1885 /* lookup the variable in question */
1886 if (isdigit(var[0])) {
1887 /* handle_dollar() should have vetted var for us */
1889 if (i < G.global_argc)
1890 val = G.global_argv[i];
1891 /* else val remains NULL: $N with too big N */
1893 val = get_local_var_value(var);
1895 /* handle any expansions */
1897 debug_printf_expand("expand: length of '%s' = ", val);
1898 val = utoa(val ? strlen(val) : 0);
1899 debug_printf_expand("%s\n", val);
1900 } else if (exp_off) {
1901 if (exp_op == '%' || exp_op == '#') {
1902 /* we need to do a pattern match */
1905 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1906 if (exp_op == *exp_word) /* ## or %% */
1908 val = dyn_val = xstrdup(val);
1909 loc = scan(dyn_val, exp_word, zero);
1915 /* we need to do an expansion */
1916 int exp_test = (!val || (exp_null && !val[0]));
1918 exp_test = !exp_test;
1919 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1920 exp_null ? "true" : "false", exp_test);
1923 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1927 if (exp_op == '=') {
1928 if (isdigit(var[0]) || var[0] == '#') {
1929 maybe_die(var, "special vars cannot assign in this way");
1932 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1933 sprintf(new_var, "%s=%s", var, val);
1934 set_local_var(new_var, -1, 0);
1940 var[exp_off] = exp_save;
1944 #if ENABLE_HUSH_TICK
1947 if (!(first_ch & 0x80)) { /* unquoted $VAR */
1948 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
1950 /* unquoted var's contents should be globbed, so don't escape */
1951 smallint sv = output->o_escape;
1952 output->o_escape = 0;
1953 n = expand_on_ifs(output, n, val);
1955 output->o_escape = sv;
1957 } else { /* quoted $VAR, val will be appended below */
1958 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
1961 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
1963 o_addQstr(output, val, strlen(val));
1967 /* Do the check to avoid writing to a const string */
1968 if (*p != SPECIAL_VAR_SYMBOL)
1969 *p = SPECIAL_VAR_SYMBOL;
1971 #if ENABLE_HUSH_TICK
1972 o_free(&subst_result);
1975 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
1978 debug_print_list("expand_vars_to_list[a]", output, n);
1979 /* this part is literal, and it was already pre-quoted
1980 * if needed (much earlier), do not use o_addQstr here! */
1981 o_addstr_with_NUL(output, arg);
1982 debug_print_list("expand_vars_to_list[b]", output, n);
1983 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
1984 && !(ored_ch & 0x80) /* and all vars were not quoted. */
1987 /* allow to reuse list[n] later without re-growth */
1988 output->has_empty_slot = 1;
1990 o_addchr(output, '\0');
1995 static char **expand_variables(char **argv, int or_mask)
2000 o_string output = NULL_O_STRING;
2002 if (or_mask & 0x100) {
2003 output.o_escape = 1; /* protect against globbing for "$var" */
2004 /* (unquoted $var will temporarily switch it off) */
2011 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2014 debug_print_list("expand_variables", &output, n);
2016 /* output.data (malloced in one block) gets returned in "list" */
2017 list = o_finalize_list(&output, n);
2018 debug_print_strings("expand_variables[1]", list);
2022 static char **expand_strvec_to_strvec(char **argv)
2024 return expand_variables(argv, 0x100);
2027 /* Used for expansion of right hand of assignments */
2028 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2030 static char *expand_string_to_string(const char *str)
2032 char *argv[2], **list;
2034 argv[0] = (char*)str;
2036 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2038 if (!list[0] || list[1])
2039 bb_error_msg_and_die("BUG in varexp2");
2040 /* actually, just move string 2*sizeof(char*) bytes back */
2041 overlapping_strcpy((char*)list, list[0]);
2042 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2046 /* Used for "eval" builtin */
2047 static char* expand_strvec_to_string(char **argv)
2051 list = expand_variables(argv, 0x80);
2052 /* Convert all NULs to spaces */
2057 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2058 bb_error_msg_and_die("BUG in varexp3");
2059 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2063 overlapping_strcpy((char*)list, list[0]);
2064 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2068 static char **expand_assignments(char **argv, int count)
2072 /* Expand assignments into one string each */
2073 for (i = 0; i < count; i++) {
2074 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2081 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2082 #define clean_up_after_re_execute() ((void)0)
2083 static void reset_traps_to_defaults(void)
2091 for (sig = 0; sig < NSIG; sig++) {
2095 G.traps[sig] = NULL;
2096 /* There is no signal for 0 (EXIT) */
2099 /* there was a trap handler, we are removing it
2100 * (if sig has non-DFL handling,
2101 * we don't need to do anything) */
2102 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2104 sigdelset(&G.blocked_set, sig);
2108 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2113 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2114 static void re_execute_shell(const char *s, int is_heredoc)
2116 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2117 struct variable *cur;
2118 char **argv, **pp, **pp2;
2121 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2122 , (unsigned) G.root_pid
2123 , (unsigned) G.last_bg_pid
2124 , (unsigned) G.last_exitcode
2125 USE_HUSH_LOOPS(, G.depth_of_loop)
2127 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2128 * 3:-c 4:<cmd> <argN...> 5:NULL
2130 cnt = 5 + G.global_argc;
2131 for (cur = G.top_var; cur; cur = cur->next) {
2132 if (!cur->flg_export || cur->flg_read_only)
2135 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2136 *pp++ = (char *) G.argv0_for_re_execing;
2138 for (cur = G.top_var; cur; cur = cur->next) {
2139 if (cur->varstr == hush_version_str)
2141 if (cur->flg_read_only) {
2142 *pp++ = (char *) "-R";
2143 *pp++ = cur->varstr;
2144 } else if (!cur->flg_export) {
2145 *pp++ = (char *) "-V";
2146 *pp++ = cur->varstr;
2149 //TODO: pass functions
2150 /* We can pass activated traps here. Say, -Tnn:trap_string
2152 * However, POSIX says that subshells reset signals with traps
2154 * I tested bash-3.2 and it not only does that with true subshells
2155 * of the form ( list ), but with any forked children shells.
2156 * I set trap "echo W" WINCH; and then tried:
2158 * { echo 1; sleep 20; echo 2; } &
2159 * while true; do echo 1; sleep 20; echo 2; break; done &
2160 * true | { echo 1; sleep 20; echo 2; } | cat
2162 * In all these cases sending SIGWINCH to the child shell
2163 * did not run the trap. If I add trap "echo V" WINCH;
2164 * _inside_ group (just before echo 1), it works.
2166 * I conclude it means we don't need to pass active traps here.
2167 * exec syscall below resets them to SIG_DFL for us.
2169 *pp++ = (char *) (is_heredoc ? "-<" : "-c");
2171 pp2 = G.global_argv;
2174 /* *pp = NULL; - is already there */
2176 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2177 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2178 execv(bb_busybox_exec_path, G.argv_from_re_execing);
2179 /* Fallback. Useful for init=/bin/hush usage etc */
2180 if (G.argv0_for_re_execing[0] == '/')
2181 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2182 xfunc_error_retval = 127;
2183 bb_error_msg_and_die("can't re-execute the shell");
2186 static void clean_up_after_re_execute(void)
2188 char **pp = G.argv_from_re_execing;
2190 /* Must match re_execute_shell's allocations (if any) */
2192 G.argv_from_re_execing = NULL;
2195 #endif /* !BB_MMU */
2198 static void setup_heredoc(int fd, const char *heredoc)
2200 struct fd_pair pair;
2205 xmove_fd(pair.rd, fd);
2207 len = strlen(heredoc);
2208 /* Try writing without forking. Newer kernels have
2209 * dynamically growing pipes. Must use non-blocking write! */
2212 written = write(pair.wr, heredoc, len);
2222 ndelay_off(pair.wr);
2224 /* Okay, pipe buffer was not big enough */
2225 /* Note: we must not create a stray child (bastard? :)
2226 * for the unsuspecting parent process. Child creates a grandchild
2227 * and exits before parent execs the process which consumes heredoc
2228 * (that exec happens after we return from this function) */
2231 bb_perror_msg_and_die("vfork");
2234 pid = BB_MMU ? fork() : vfork();
2236 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2240 close(fd); /* read side of the pipe */
2242 full_write(pair.wr, heredoc, len); /* may loop or block */
2245 /* Delegate blocking writes to another process */
2246 disable_restore_tty_pgrp_on_exit();
2247 xmove_fd(pair.wr, STDOUT_FILENO);
2248 re_execute_shell(heredoc, 1);
2252 enable_restore_tty_pgrp_on_exit();
2253 clean_up_after_re_execute();
2255 wait(NULL); /* wait till child has died */
2258 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2259 * and stderr if they are redirected. */
2260 static int setup_redirects(struct command *prog, int squirrel[])
2262 //TODO: no callers ever check return value - ?!
2264 struct redir_struct *redir;
2266 for (redir = prog->redirects; redir; redir = redir->next) {
2267 if (redir->rd_type == REDIRECT_HEREDOC2) {
2268 if (squirrel && redir->rd_fd < 3) {
2269 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2271 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2273 debug_printf_parse("set heredoc '%s'\n",
2274 redir->rd_filename);
2275 setup_heredoc(redir->rd_fd, redir->rd_filename);
2279 if (redir->rd_dup == -1) {
2281 if (redir->rd_filename == NULL) {
2282 /* Something went wrong in the parse.
2283 * Pretend it didn't happen */
2286 mode = redir_table[redir->rd_type].mode;
2287 //TODO: check redir for names like '\\'
2288 p = expand_string_to_string(redir->rd_filename);
2289 openfd = open_or_warn(p, mode);
2292 /* this could get lost if stderr has been redirected, but
2293 * bash and ash both lose it as well (though zsh doesn't!) */
2294 //what the above comment tries to say?
2298 openfd = redir->rd_dup;
2301 if (openfd != redir->rd_fd) {
2302 if (squirrel && redir->rd_fd < 3) {
2303 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2306 /* "-" means "close me" and we use -3 for that */
2307 close(redir->rd_fd);
2309 dup2(openfd, redir->rd_fd);
2310 if (redir->rd_dup == -1)
2318 static void restore_redirects(int squirrel[])
2321 for (i = 0; i < 3; i++) {
2324 /* We simply die on error */
2332 #define free_pipe_list(head, indent) free_pipe_list(head)
2333 #define free_pipe(pi, indent) free_pipe(pi)
2335 static void free_pipe_list(struct pipe *head, int indent);
2337 /* Return code is the exit status of the pipe */
2338 static void free_pipe(struct pipe *pi, int indent)
2341 struct command *command;
2342 struct redir_struct *r, *rnext;
2345 if (pi->stopped_cmds > 0) /* why? */
2347 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2348 for (i = 0; i < pi->num_cmds; i++) {
2349 command = &pi->cmds[i];
2350 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2351 if (command->argv) {
2352 for (a = 0, p = command->argv; *p; a++, p++) {
2353 debug_printf_clean("%s argv[%d] = %s\n", indenter(indent), a, *p);
2355 free_strings(command->argv);
2356 command->argv = NULL;
2358 /* not "else if": on syntax error, we may have both! */
2359 if (command->group) {
2360 debug_printf_clean("%s begin group (grp_type:%d)\n", indenter(indent), command->grp_type);
2361 free_pipe_list(command->group, indent+3);
2362 debug_printf_clean("%s end group\n", indenter(indent));
2363 command->group = NULL;
2366 free(command->group_as_string);
2367 command->group_as_string = NULL;
2369 for (r = command->redirects; r; r = rnext) {
2370 debug_printf_clean("%s redirect %d%s", indenter(indent), r->fd, redir_table[r->rd_type].descrip);
2371 if (r->rd_dup == -1) {
2372 /* guard against the case >$FOO, where foo is unset or blank */
2373 if (r->rd_filename) {
2374 debug_printf_clean(" %s\n", r->rd_filename);
2375 free(r->rd_filename);
2376 r->rd_filename = NULL;
2379 debug_printf_clean("&%d\n", r->rd_dup);
2384 command->redirects = NULL;
2386 free(pi->cmds); /* children are an array, they get freed all at once */
2394 static void free_pipe_list(struct pipe *head, int indent)
2396 struct pipe *pi, *next;
2398 for (pi = head; pi; pi = next) {
2400 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2402 free_pipe(pi, indent);
2403 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2405 /*pi->next = NULL;*/
2412 typedef struct nommu_save_t {
2418 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2419 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2420 #define pseudo_exec(nommu_save, command, argv_expanded) \
2421 pseudo_exec(command, argv_expanded)
2424 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2426 * XXX no exit() here. If you don't exec, use _exit instead.
2427 * The at_exit handlers apparently confuse the calling process,
2428 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2429 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2430 char **argv, int assignment_cnt,
2431 char **argv_expanded) NORETURN;
2432 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2433 char **argv, int assignment_cnt,
2434 char **argv_expanded)
2438 /* Case when we are here: ... | var=val | ... */
2439 if (!argv[assignment_cnt])
2440 _exit(EXIT_SUCCESS);
2442 new_env = expand_assignments(argv, assignment_cnt);
2444 putenv_all(new_env);
2445 free(new_env); /* optional */
2447 nommu_save->new_env = new_env;
2448 nommu_save->old_env = putenv_all_and_save_old(new_env);
2450 if (argv_expanded) {
2451 argv = argv_expanded;
2453 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2455 nommu_save->argv = argv;
2459 /* On NOMMU, we must never block!
2460 * Example: { sleep 99999 | read line } & echo Ok
2461 * read builtin will block on read syscall, leaving parent blocked
2462 * in vfork. Therefore we can't do this:
2465 /* Check if the command matches any of the builtins.
2466 * Depending on context, this might be redundant. But it's
2467 * easier to waste a few CPU cycles than it is to figure out
2468 * if this is one of those cases.
2472 const struct built_in_command *x;
2473 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2474 if (strcmp(argv[0], x->cmd) == 0) {
2475 debug_printf_exec("running builtin '%s'\n",
2477 rcode = x->function(argv);
2485 #if ENABLE_FEATURE_SH_STANDALONE
2486 /* Check if the command matches any busybox applets */
2487 if (strchr(argv[0], '/') == NULL) {
2488 int a = find_applet_by_name(argv[0]);
2490 #if BB_MMU /* see above why on NOMMU it is not allowed */
2491 if (APPLET_IS_NOEXEC(a)) {
2492 debug_printf_exec("running applet '%s'\n", argv[0]);
2493 run_applet_no_and_exit(a, argv);
2496 /* Re-exec ourselves */
2497 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2498 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2499 execv(bb_busybox_exec_path, argv);
2500 /* If they called chroot or otherwise made the binary no longer
2501 * executable, fall through */
2506 debug_printf_exec("execing '%s'\n", argv[0]);
2507 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2508 execvp(argv[0], argv);
2509 bb_perror_msg("can't exec '%s'", argv[0]);
2510 _exit(EXIT_FAILURE);
2513 static int run_list(struct pipe *pi);
2515 /* Called after [v]fork() in run_pipe
2517 static void pseudo_exec(nommu_save_t *nommu_save,
2518 struct command *command,
2519 char **argv_expanded) NORETURN;
2520 static void pseudo_exec(nommu_save_t *nommu_save,
2521 struct command *command,
2522 char **argv_expanded)
2524 if (command->argv) {
2525 pseudo_exec_argv(nommu_save, command->argv,
2526 command->assignment_cnt, argv_expanded);
2529 if (command->group) {
2530 /* Cases when we are here:
2533 * ... | ( list ) | ...
2534 * ... | { list } | ...
2538 debug_printf_exec("pseudo_exec: run_list\n");
2539 reset_traps_to_defaults();
2540 rcode = run_list(command->group);
2541 /* OK to leak memory by not calling free_pipe_list,
2542 * since this process is about to exit */
2545 re_execute_shell(command->group_as_string, 0);
2549 /* Case when we are here: ... | >file */
2550 debug_printf_exec("pseudo_exec'ed null command\n");
2551 _exit(EXIT_SUCCESS);
2555 static const char *get_cmdtext(struct pipe *pi)
2561 /* This is subtle. ->cmdtext is created only on first backgrounding.
2562 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2563 * On subsequent bg argv is trashed, but we won't use it */
2566 argv = pi->cmds[0].argv;
2567 if (!argv || !argv[0]) {
2568 pi->cmdtext = xzalloc(1);
2573 do len += strlen(*argv) + 1; while (*++argv);
2574 pi->cmdtext = p = xmalloc(len);
2575 argv = pi->cmds[0].argv;
2577 len = strlen(*argv);
2578 memcpy(p, *argv, len);
2586 static void insert_bg_job(struct pipe *pi)
2588 struct pipe *thejob;
2591 /* Linear search for the ID of the job to use */
2593 for (thejob = G.job_list; thejob; thejob = thejob->next)
2594 if (thejob->jobid >= pi->jobid)
2595 pi->jobid = thejob->jobid + 1;
2597 /* Add thejob to the list of running jobs */
2599 thejob = G.job_list = xmalloc(sizeof(*thejob));
2601 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2603 thejob->next = xmalloc(sizeof(*thejob));
2604 thejob = thejob->next;
2607 /* Physically copy the struct job */
2608 memcpy(thejob, pi, sizeof(struct pipe));
2609 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2610 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2611 for (i = 0; i < pi->num_cmds; i++) {
2612 // TODO: do we really need to have so many fields which are just dead weight
2613 // at execution stage?
2614 thejob->cmds[i].pid = pi->cmds[i].pid;
2615 /* all other fields are not used and stay zero */
2617 thejob->next = NULL;
2618 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2620 /* We don't wait for background thejobs to return -- append it
2621 to the list of backgrounded thejobs and leave it alone */
2622 if (G_interactive_fd)
2623 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2624 G.last_bg_pid = thejob->cmds[0].pid;
2625 G.last_jobid = thejob->jobid;
2628 static void remove_bg_job(struct pipe *pi)
2630 struct pipe *prev_pipe;
2632 if (pi == G.job_list) {
2633 G.job_list = pi->next;
2635 prev_pipe = G.job_list;
2636 while (prev_pipe->next != pi)
2637 prev_pipe = prev_pipe->next;
2638 prev_pipe->next = pi->next;
2641 G.last_jobid = G.job_list->jobid;
2646 /* Remove a backgrounded job */
2647 static void delete_finished_bg_job(struct pipe *pi)
2650 pi->stopped_cmds = 0;
2656 /* Check to see if any processes have exited -- if they
2657 * have, figure out why and see if a job has completed */
2658 static int checkjobs(struct pipe* fg_pipe)
2668 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2671 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2672 // /* avoid doing syscall, nothing there anyway */
2675 attributes = WUNTRACED;
2676 if (fg_pipe == NULL)
2677 attributes |= WNOHANG;
2679 /* Do we do this right?
2680 * bash-3.00# sleep 20 | false
2682 * [3]+ Stopped sleep 20 | false
2683 * bash-3.00# echo $?
2684 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2687 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2688 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2689 // + killall -STOP cat
2696 // i = G.count_SIGCHLD;
2697 childpid = waitpid(-1, &status, attributes);
2698 if (childpid <= 0) {
2699 if (childpid && errno != ECHILD)
2700 bb_perror_msg("waitpid");
2701 // else /* Until next SIGCHLD, waitpid's are useless */
2702 // G.handled_SIGCHLD = i;
2705 dead = WIFEXITED(status) || WIFSIGNALED(status);
2708 if (WIFSTOPPED(status))
2709 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2710 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2711 if (WIFSIGNALED(status))
2712 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2713 childpid, WTERMSIG(status), WEXITSTATUS(status));
2714 if (WIFEXITED(status))
2715 debug_printf_jobs("pid %d exited, exitcode %d\n",
2716 childpid, WEXITSTATUS(status));
2718 /* Were we asked to wait for fg pipe? */
2720 for (i = 0; i < fg_pipe->num_cmds; i++) {
2721 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2722 if (fg_pipe->cmds[i].pid != childpid)
2724 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2726 fg_pipe->cmds[i].pid = 0;
2727 fg_pipe->alive_cmds--;
2728 if (i == fg_pipe->num_cmds - 1) {
2729 /* last process gives overall exitstatus */
2730 rcode = WEXITSTATUS(status);
2731 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2734 fg_pipe->cmds[i].is_stopped = 1;
2735 fg_pipe->stopped_cmds++;
2737 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2738 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2739 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2740 /* All processes in fg pipe have exited/stopped */
2742 if (fg_pipe->alive_cmds)
2743 insert_bg_job(fg_pipe);
2747 /* There are still running processes in the fg pipe */
2748 goto wait_more; /* do waitpid again */
2750 /* it wasnt fg_pipe, look for process in bg pipes */
2754 /* We asked to wait for bg or orphaned children */
2755 /* No need to remember exitcode in this case */
2756 for (pi = G.job_list; pi; pi = pi->next) {
2757 for (i = 0; i < pi->num_cmds; i++) {
2758 if (pi->cmds[i].pid == childpid)
2759 goto found_pi_and_prognum;
2762 /* Happens when shell is used as init process (init=/bin/sh) */
2763 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2764 continue; /* do waitpid again */
2766 found_pi_and_prognum:
2769 pi->cmds[i].pid = 0;
2771 if (!pi->alive_cmds) {
2772 if (G_interactive_fd)
2773 printf(JOB_STATUS_FORMAT, pi->jobid,
2774 "Done", pi->cmdtext);
2775 delete_finished_bg_job(pi);
2779 pi->cmds[i].is_stopped = 1;
2783 } /* while (waitpid succeeds)... */
2789 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2792 int rcode = checkjobs(fg_pipe);
2793 /* Job finished, move the shell to the foreground */
2794 p = getpgid(0); /* pgid of our process */
2795 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2796 tcsetpgrp(G_interactive_fd, p);
2801 /* Start all the jobs, but don't wait for anything to finish.
2804 * Return code is normally -1, when the caller has to wait for children
2805 * to finish to determine the exit status of the pipe. If the pipe
2806 * is a simple builtin command, however, the action is done by the
2807 * time run_pipe returns, and the exit code is provided as the
2810 * Returns -1 only if started some children. IOW: we have to
2811 * mask out retvals of builtins etc with 0xff!
2813 * The only case when we do not need to [v]fork is when the pipe
2814 * is single, non-backgrounded, non-subshell command. Examples:
2815 * cmd ; ... { list } ; ...
2816 * cmd && ... { list } && ...
2817 * cmd || ... { list } || ...
2818 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2819 * or (if SH_STANDALONE) an applet, and we can run the { list }
2820 * with run_list(). If it isn't one of these, we fork and exec cmd.
2822 * Cases when we must fork:
2823 * non-single: cmd | cmd
2824 * backgrounded: cmd & { list } &
2825 * subshell: ( list ) [&]
2827 static int run_pipe(struct pipe *pi)
2829 static const char *const null_ptr = NULL;
2832 int pipefds[2]; /* pipefds[0] is for reading */
2833 struct command *command;
2834 char **argv_expanded;
2837 /* it is not always needed, but we aim to smaller code */
2838 int squirrel[] = { -1, -1, -1 };
2841 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2843 USE_HUSH_JOB(pi->pgrp = -1;)
2844 pi->stopped_cmds = 0;
2845 command = &(pi->cmds[0]);
2846 argv_expanded = NULL;
2848 if (pi->num_cmds != 1
2849 || pi->followup == PIPE_BG
2850 || command->grp_type == GRP_SUBSHELL
2857 debug_printf_exec(": group:%p argv:'%s'\n",
2858 command->group, command->argv ? command->argv[0] : "NONE");
2860 if (command->group) {
2861 #if ENABLE_HUSH_FUNCTIONS
2862 if (command->grp_type == GRP_FUNCTION) {
2863 /* func () { list } */
2864 bb_error_msg("here we ought to remember function definition, and go on");
2865 return EXIT_SUCCESS;
2869 debug_printf("non-subshell group\n");
2870 setup_redirects(command, squirrel);
2871 debug_printf_exec(": run_list\n");
2872 rcode = run_list(command->group) & 0xff;
2873 restore_redirects(squirrel);
2874 debug_printf_exec("run_pipe return %d\n", rcode);
2875 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2879 argv = command->argv ? command->argv : (char **) &null_ptr;
2881 const struct built_in_command *x;
2882 char **new_env = NULL;
2883 char **old_env = NULL;
2885 if (argv[command->assignment_cnt] == NULL) {
2886 /* Assignments, but no command */
2887 /* Ensure redirects take effect. Try "a=t >file" */
2888 setup_redirects(command, squirrel);
2889 restore_redirects(squirrel);
2890 /* Set shell variables */
2892 p = expand_string_to_string(*argv);
2893 debug_printf_exec("set shell var:'%s'->'%s'\n",
2895 set_local_var(p, 0, 0);
2898 /* Do we need to flag set_local_var() errors?
2899 * "assignment to readonly var" and "putenv error"
2901 return EXIT_SUCCESS;
2904 /* Expand the rest into (possibly) many strings each */
2905 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2907 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2908 if (strcmp(argv_expanded[0], x->cmd) != 0)
2910 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2911 debug_printf("exec with redirects only\n");
2912 setup_redirects(command, NULL);
2913 rcode = EXIT_SUCCESS;
2914 goto clean_up_and_ret1;
2916 debug_printf("builtin inline %s\n", argv_expanded[0]);
2917 /* XXX setup_redirects acts on file descriptors, not FILEs.
2918 * This is perfect for work that comes after exec().
2919 * Is it really safe for inline use? Experimentally,
2920 * things seem to work with glibc. */
2921 setup_redirects(command, squirrel);
2922 new_env = expand_assignments(argv, command->assignment_cnt);
2923 old_env = putenv_all_and_save_old(new_env);
2924 debug_printf_exec(": builtin '%s' '%s'...\n",
2925 x->cmd, argv_expanded[1]);
2926 rcode = x->function(argv_expanded) & 0xff;
2927 #if ENABLE_FEATURE_SH_STANDALONE
2930 restore_redirects(squirrel);
2931 free_strings_and_unsetenv(new_env, 1);
2932 putenv_all(old_env);
2933 free(old_env); /* not free_strings()! */
2935 free(argv_expanded);
2936 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2937 debug_printf_exec("run_pipe return %d\n", rcode);
2940 #if ENABLE_FEATURE_SH_STANDALONE
2941 i = find_applet_by_name(argv_expanded[0]);
2942 if (i >= 0 && APPLET_IS_NOFORK(i)) {
2943 setup_redirects(command, squirrel);
2944 save_nofork_data(&G.nofork_save);
2945 new_env = expand_assignments(argv, command->assignment_cnt);
2946 old_env = putenv_all_and_save_old(new_env);
2947 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
2948 argv_expanded[0], argv_expanded[1]);
2949 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
2950 goto clean_up_and_ret;
2953 /* It is neither builtin nor applet. We must fork. */
2957 /* NB: argv_expanded may already be created, and that
2958 * might include `cmd` runs! Do not rerun it! We *must*
2959 * use argv_expanded if it's non-NULL */
2961 /* Going to fork a child per each pipe member */
2965 for (i = 0; i < pi->num_cmds; i++) {
2967 volatile nommu_save_t nommu_save;
2968 nommu_save.new_env = NULL;
2969 nommu_save.old_env = NULL;
2970 nommu_save.argv = NULL;
2972 command = &(pi->cmds[i]);
2973 if (command->argv) {
2974 debug_printf_exec(": pipe member '%s' '%s'...\n",
2975 command->argv[0], command->argv[1]);
2977 debug_printf_exec(": pipe member with no argv\n");
2980 /* pipes are inserted between pairs of commands */
2983 if ((i + 1) < pi->num_cmds)
2986 command->pid = BB_MMU ? fork() : vfork();
2987 if (!command->pid) { /* child */
2989 disable_restore_tty_pgrp_on_exit();
2991 /* Every child adds itself to new process group
2992 * with pgid == pid_of_first_child_in_pipe */
2993 if (G.run_list_level == 1 && G_interactive_fd) {
2996 if (pgrp < 0) /* true for 1st process only */
2998 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
2999 /* We do it in *every* child, not just first,
3001 tcsetpgrp(G_interactive_fd, pgrp);
3005 xmove_fd(nextin, 0);
3006 xmove_fd(pipefds[1], 1); /* write end */
3008 close(pipefds[0]); /* read end */
3009 /* Like bash, explicit redirects override pipes,
3010 * and the pipe fd is available for dup'ing. */
3011 setup_redirects(command, NULL);
3013 /* Restore default handlers just prior to exec */
3014 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3016 /* Stores to nommu_save list of env vars putenv'ed
3017 * (NOMMU, on MMU we don't need that) */
3018 /* cast away volatility... */
3019 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3020 /* pseudo_exec() does not return */
3023 /* parent or error */
3024 enable_restore_tty_pgrp_on_exit();
3026 /* Clean up after vforked child */
3027 clean_up_after_re_execute();
3028 free(nommu_save.argv);
3029 free_strings_and_unsetenv(nommu_save.new_env, 1);
3030 putenv_all(nommu_save.old_env);
3032 free(argv_expanded);
3033 argv_expanded = NULL;
3034 if (command->pid < 0) { /* [v]fork failed */
3035 /* Clearly indicate, was it fork or vfork */
3036 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3040 /* Second and next children need to know pid of first one */
3042 pi->pgrp = command->pid;
3048 if ((i + 1) < pi->num_cmds)
3049 close(pipefds[1]); /* write end */
3050 /* Pass read (output) pipe end to next iteration */
3051 nextin = pipefds[0];
3054 if (!pi->alive_cmds) {
3055 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3059 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3063 #ifndef debug_print_tree
3064 static void debug_print_tree(struct pipe *pi, int lvl)
3066 static const char *const PIPE[] = {
3072 static const char *RES[] = {
3073 [RES_NONE ] = "NONE" ,
3076 [RES_THEN ] = "THEN" ,
3077 [RES_ELIF ] = "ELIF" ,
3078 [RES_ELSE ] = "ELSE" ,
3081 #if ENABLE_HUSH_LOOPS
3082 [RES_FOR ] = "FOR" ,
3083 [RES_WHILE] = "WHILE",
3084 [RES_UNTIL] = "UNTIL",
3086 [RES_DONE ] = "DONE" ,
3088 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3091 #if ENABLE_HUSH_CASE
3092 [RES_CASE ] = "CASE" ,
3093 [RES_MATCH] = "MATCH",
3094 [RES_CASEI] = "CASEI",
3095 [RES_ESAC ] = "ESAC" ,
3097 [RES_XXXX ] = "XXXX" ,
3098 [RES_SNTX ] = "SNTX" ,
3100 static const char *const GRPTYPE[] = {
3103 #if ENABLE_HUSH_FUNCTIONS
3112 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3113 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3115 while (prn < pi->num_cmds) {
3116 struct command *command = &pi->cmds[prn];
3117 char **argv = command->argv;
3119 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3121 command->assignment_cnt);
3122 if (command->group) {
3123 fprintf(stderr, " group %s: (argv=%p)\n",
3124 GRPTYPE[command->grp_type],
3126 debug_print_tree(command->group, lvl+1);
3130 if (argv) while (*argv) {
3131 fprintf(stderr, " '%s'", *argv);
3134 fprintf(stderr, "\n");
3143 /* NB: called by pseudo_exec, and therefore must not modify any
3144 * global data until exec/_exit (we can be a child after vfork!) */
3145 static int run_list(struct pipe *pi)
3147 #if ENABLE_HUSH_CASE
3148 char *case_word = NULL;
3150 #if ENABLE_HUSH_LOOPS
3151 struct pipe *loop_top = NULL;
3152 char *for_varname = NULL;
3153 char **for_lcur = NULL;
3154 char **for_list = NULL;
3156 smallint last_followup;
3158 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3159 smalluint cond_code = 0;
3161 enum { cond_code = 0 };
3164 smallint rword; /* enum reserved_style */
3165 smallint last_rword; /* ditto */
3168 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3170 #if ENABLE_HUSH_LOOPS
3171 /* Check syntax for "for" */
3172 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3173 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3175 /* current word is FOR or IN (BOLD in comments below) */
3176 if (cpipe->next == NULL) {
3177 syntax("malformed for");
3178 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3181 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3182 if (cpipe->next->res_word == RES_DO)
3184 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3185 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3186 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3188 syntax("malformed for");
3189 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3195 /* Past this point, all code paths should jump to ret: label
3196 * in order to return, no direct "return" statements please.
3197 * This helps to ensure that no memory is leaked. */
3199 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3202 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3203 * We are saving state before entering outermost list ("while...done")
3204 * so that ctrl-Z will correctly background _entire_ outermost list,
3205 * not just a part of it (like "sleep 1 | exit 2") */
3206 if (++G.run_list_level == 1 && G_interactive_fd) {
3207 if (sigsetjmp(G.toplevel_jb, 1)) {
3208 /* ctrl-Z forked and we are parent; or ctrl-C.
3209 * Sighandler has longjmped us here */
3210 signal(SIGINT, SIG_IGN);
3211 signal(SIGTSTP, SIG_IGN);
3212 /* Restore level (we can be coming from deep inside
3214 G.run_list_level = 1;
3215 #if ENABLE_FEATURE_SH_STANDALONE
3216 if (G.nofork_save.saved) { /* if save area is valid */
3217 debug_printf_jobs("exiting nofork early\n");
3218 restore_nofork_data(&G.nofork_save);
3221 //// if (G.ctrl_z_flag) {
3222 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3223 //// * Remember this child as background job */
3224 //// insert_bg_job(pi);
3226 /* ctrl-C. We just stop doing whatever we were doing */
3229 USE_HUSH_LOOPS(loop_top = NULL;)
3230 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3234 //// /* ctrl-Z handler will store pid etc in pi */
3235 //// G.toplevel_list = pi;
3236 //// G.ctrl_z_flag = 0;
3237 ////#if ENABLE_FEATURE_SH_STANDALONE
3238 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3240 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3241 //// signal(SIGINT, handler_ctrl_c);
3247 last_rword = RES_XXXX;
3249 last_followup = PIPE_SEQ;
3250 rcode = G.last_exitcode;
3252 /* Go through list of pipes, (maybe) executing them. */
3253 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3257 IF_HAS_KEYWORDS(rword = pi->res_word;)
3258 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3259 rword, cond_code, last_rword);
3260 #if ENABLE_HUSH_LOOPS
3261 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3262 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3264 /* start of a loop: remember where loop starts */
3269 /* Still in the same "if...", "then..." or "do..." branch? */
3270 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3271 if ((rcode == 0 && last_followup == PIPE_OR)
3272 || (rcode != 0 && last_followup == PIPE_AND)
3274 /* It is "<true> || CMD" or "<false> && CMD"
3275 * and we should not execute CMD */
3276 debug_printf_exec("skipped cmd because of || or &&\n");
3277 last_followup = pi->followup;
3281 last_followup = pi->followup;
3282 IF_HAS_KEYWORDS(last_rword = rword;)
3285 if (rword == RES_THEN) {
3286 /* if false; then ... fi has exitcode 0! */
3287 G.last_exitcode = rcode = EXIT_SUCCESS;
3288 /* "if <false> THEN cmd": skip cmd */
3292 if (rword == RES_ELSE || rword == RES_ELIF) {
3293 /* "if <true> then ... ELSE/ELIF cmd":
3294 * skip cmd and all following ones */
3299 #if ENABLE_HUSH_LOOPS
3300 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3302 /* first loop through for */
3304 static const char encoded_dollar_at[] ALIGN1 = {
3305 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3306 }; /* encoded representation of "$@" */
3307 static const char *const encoded_dollar_at_argv[] = {
3308 encoded_dollar_at, NULL
3309 }; /* argv list with one element: "$@" */
3312 vals = (char**)encoded_dollar_at_argv;
3313 if (pi->next->res_word == RES_IN) {
3314 /* if no variable values after "in" we skip "for" */
3315 if (!pi->next->cmds[0].argv) {
3316 G.last_exitcode = rcode = EXIT_SUCCESS;
3317 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3320 vals = pi->next->cmds[0].argv;
3321 } /* else: "for var; do..." -> assume "$@" list */
3322 /* create list of variable values */
3323 debug_print_strings("for_list made from", vals);
3324 for_list = expand_strvec_to_strvec(vals);
3325 for_lcur = for_list;
3326 debug_print_strings("for_list", for_list);
3327 for_varname = pi->cmds[0].argv[0];
3328 pi->cmds[0].argv[0] = NULL;
3330 free(pi->cmds[0].argv[0]);
3332 /* "for" loop is over, clean up */
3336 pi->cmds[0].argv[0] = for_varname;
3339 /* Insert next value from for_lcur */
3340 //TODO: does it need escaping?
3341 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3342 pi->cmds[0].assignment_cnt = 1;
3344 if (rword == RES_IN) {
3345 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3347 if (rword == RES_DONE) {
3348 continue; /* "done" has no cmds too */
3351 #if ENABLE_HUSH_CASE
3352 if (rword == RES_CASE) {
3353 case_word = expand_strvec_to_string(pi->cmds->argv);
3356 if (rword == RES_MATCH) {
3359 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3361 /* all prev words didn't match, does this one match? */
3362 argv = pi->cmds->argv;
3364 char *pattern = expand_string_to_string(*argv);
3365 /* TODO: which FNM_xxx flags to use? */
3366 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3368 if (cond_code == 0) { /* match! we will execute this branch */
3369 free(case_word); /* make future "word)" stop */
3377 if (rword == RES_CASEI) { /* inside of a case branch */
3379 continue; /* not matched yet, skip this pipe */
3382 /* Just pressing <enter> in shell should check for jobs.
3383 * OTOH, in non-interactive shell this is useless
3384 * and only leads to extra job checks */
3385 if (pi->num_cmds == 0) {
3386 if (G_interactive_fd)
3387 goto check_jobs_and_continue;
3391 /* After analyzing all keywords and conditions, we decided
3392 * to execute this pipe. NB: have to do checkjobs(NULL)
3393 * after run_pipe to collect any background children,
3394 * even if list execution is to be stopped. */
3395 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3398 #if ENABLE_HUSH_LOOPS
3399 G.flag_break_continue = 0;
3401 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3403 /* We only ran a builtin: rcode is already known
3404 * and we don't need to wait for anything. */
3405 G.last_exitcode = rcode;
3406 debug_printf_exec(": builtin exitcode %d\n", rcode);
3407 check_and_run_traps(0);
3408 #if ENABLE_HUSH_LOOPS
3409 /* Was it "break" or "continue"? */
3410 if (G.flag_break_continue) {
3411 smallint fbc = G.flag_break_continue;
3412 /* We might fall into outer *loop*,
3413 * don't want to break it too */
3415 G.depth_break_continue--;
3416 if (G.depth_break_continue == 0)
3417 G.flag_break_continue = 0;
3418 /* else: e.g. "continue 2" should *break* once, *then* continue */
3419 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3420 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3421 goto check_jobs_and_break;
3422 /* "continue": simulate end of loop */
3427 } else if (pi->followup == PIPE_BG) {
3428 /* What does bash do with attempts to background builtins? */
3429 /* even bash 3.2 doesn't do that well with nested bg:
3430 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3431 * I'm NOT treating inner &'s as jobs */
3432 check_and_run_traps(0);
3434 if (G.run_list_level == 1)
3437 G.last_exitcode = rcode = EXIT_SUCCESS;
3438 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3441 if (G.run_list_level == 1 && G_interactive_fd) {
3442 /* Waits for completion, then fg's main shell */
3443 rcode = checkjobs_and_fg_shell(pi);
3444 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3445 check_and_run_traps(0);
3448 { /* This one just waits for completion */
3449 rcode = checkjobs(pi);
3450 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3451 check_and_run_traps(0);
3453 G.last_exitcode = rcode;
3457 /* Analyze how result affects subsequent commands */
3459 if (rword == RES_IF || rword == RES_ELIF)
3462 #if ENABLE_HUSH_LOOPS
3463 /* Beware of "while false; true; do ..."! */
3464 if (pi->next && pi->next->res_word == RES_DO) {
3465 if (rword == RES_WHILE) {
3467 /* "while false; do...done" - exitcode 0 */
3468 G.last_exitcode = rcode = EXIT_SUCCESS;
3469 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3470 goto check_jobs_and_break;
3473 if (rword == RES_UNTIL) {
3475 debug_printf_exec(": until expr is true: breaking\n");
3476 check_jobs_and_break:
3484 check_jobs_and_continue:
3489 //// if (G.ctrl_z_flag) {
3490 //// /* ctrl-Z forked somewhere in the past, we are the child,
3491 //// * and now we completed running the list. Exit. */
3497 //// if (!G.run_list_level && G_interactive_fd) {
3498 //// signal(SIGTSTP, SIG_IGN);
3499 //// signal(SIGINT, SIG_IGN);
3502 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3503 #if ENABLE_HUSH_LOOPS
3508 #if ENABLE_HUSH_CASE
3514 /* Select which version we will use */
3515 static int run_and_free_list(struct pipe *pi)
3518 debug_printf_exec("run_and_free_list entered\n");
3520 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3521 rcode = run_list(pi);
3523 /* free_pipe_list has the side effect of clearing memory.
3524 * In the long run that function can be merged with run_list,
3525 * but doing that now would hobble the debugging effort. */
3526 free_pipe_list(pi, /* indent: */ 0);
3527 debug_printf_exec("run_and_free_list return %d\n", rcode);
3532 static struct pipe *new_pipe(void)
3535 pi = xzalloc(sizeof(struct pipe));
3536 /*pi->followup = 0; - deliberately invalid value */
3537 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3541 /* Command (member of a pipe) is complete. The only possible error here
3542 * is out of memory, in which case xmalloc exits. */
3543 static int done_command(struct parse_context *ctx)
3545 /* The command is really already in the pipe structure, so
3546 * advance the pipe counter and make a new, null command. */
3547 struct pipe *pi = ctx->pipe;
3548 struct command *command = ctx->command;
3551 if (command->group == NULL
3552 && command->argv == NULL
3553 && command->redirects == NULL
3555 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3556 memset(command, 0, sizeof(*command)); /* paranoia */
3557 return pi->num_cmds;
3560 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3561 //debug_print_tree(ctx->list_head, 20);
3563 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3566 /* Only real trickiness here is that the uncommitted
3567 * command structure is not counted in pi->num_cmds. */
3568 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3569 command = &pi->cmds[pi->num_cmds];
3570 memset(command, 0, sizeof(*command));
3572 ctx->command = command;
3573 /* but ctx->pipe and ctx->list_head remain unchanged */
3575 return pi->num_cmds; /* used only for 0/nonzero check */
3578 static void done_pipe(struct parse_context *ctx, pipe_style type)
3582 debug_printf_parse("done_pipe entered, followup %d\n", type);
3583 /* Close previous command */
3584 not_null = done_command(ctx);
3585 ctx->pipe->followup = type;
3587 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3588 ctx->ctx_inverted = 0;
3589 ctx->pipe->res_word = ctx->ctx_res_w;
3592 /* Without this check, even just <enter> on command line generates
3593 * tree of three NOPs (!). Which is harmless but annoying.
3594 * IOW: it is safe to do it unconditionally.
3595 * RES_NONE case is for "for a in; do ..." (empty IN set)
3596 * and other cases to work. */
3599 || ctx->ctx_res_w == RES_FI
3600 || ctx->ctx_res_w == RES_DONE
3601 || ctx->ctx_res_w == RES_FOR
3602 || ctx->ctx_res_w == RES_IN
3603 || ctx->ctx_res_w == RES_ESAC
3607 debug_printf_parse("done_pipe: adding new pipe: "
3608 "not_null:%d ctx->ctx_res_w:%d\n",
3609 not_null, ctx->ctx_res_w);
3611 ctx->pipe->next = new_p;
3613 /* RES_THEN, RES_DO etc are "sticky" -
3614 * they remain set for commands inside if/while.
3615 * This is used to control execution.
3616 * RES_FOR and RES_IN are NOT sticky (needed to support
3617 * cases where variable or value happens to match a keyword):
3619 #if ENABLE_HUSH_LOOPS
3620 if (ctx->ctx_res_w == RES_FOR
3621 || ctx->ctx_res_w == RES_IN)
3622 ctx->ctx_res_w = RES_NONE;
3624 #if ENABLE_HUSH_CASE
3625 if (ctx->ctx_res_w == RES_MATCH)
3626 ctx->ctx_res_w = RES_CASEI;
3628 ctx->command = NULL; /* trick done_command below */
3629 /* Create the memory for command, roughly:
3630 * ctx->pipe->cmds = new struct command;
3631 * ctx->command = &ctx->pipe->cmds[0];
3634 //debug_print_tree(ctx->list_head, 10);
3636 debug_printf_parse("done_pipe return\n");
3639 static void initialize_context(struct parse_context *ctx)
3641 memset(ctx, 0, sizeof(*ctx));
3642 ctx->pipe = ctx->list_head = new_pipe();
3643 /* Create the memory for command, roughly:
3644 * ctx->pipe->cmds = new struct command;
3645 * ctx->command = &ctx->pipe->cmds[0];
3650 /* If a reserved word is found and processed, parse context is modified
3651 * and 1 is returned.
3654 struct reserved_combo {
3657 unsigned char assignment_flag;
3661 FLAG_END = (1 << RES_NONE ),
3663 FLAG_IF = (1 << RES_IF ),
3664 FLAG_THEN = (1 << RES_THEN ),
3665 FLAG_ELIF = (1 << RES_ELIF ),
3666 FLAG_ELSE = (1 << RES_ELSE ),
3667 FLAG_FI = (1 << RES_FI ),
3669 #if ENABLE_HUSH_LOOPS
3670 FLAG_FOR = (1 << RES_FOR ),
3671 FLAG_WHILE = (1 << RES_WHILE),
3672 FLAG_UNTIL = (1 << RES_UNTIL),
3673 FLAG_DO = (1 << RES_DO ),
3674 FLAG_DONE = (1 << RES_DONE ),
3675 FLAG_IN = (1 << RES_IN ),
3677 #if ENABLE_HUSH_CASE
3678 FLAG_MATCH = (1 << RES_MATCH),
3679 FLAG_ESAC = (1 << RES_ESAC ),
3681 FLAG_START = (1 << RES_XXXX ),
3684 static const struct reserved_combo* match_reserved_word(o_string *word)
3686 /* Mostly a list of accepted follow-up reserved words.
3687 * FLAG_END means we are done with the sequence, and are ready
3688 * to turn the compound list into a command.
3689 * FLAG_START means the word must start a new compound list.
3691 static const struct reserved_combo reserved_list[] = {
3693 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3694 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3695 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3696 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3697 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3698 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3700 #if ENABLE_HUSH_LOOPS
3701 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3702 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3703 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3704 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3705 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3706 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3708 #if ENABLE_HUSH_CASE
3709 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3710 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3713 const struct reserved_combo *r;
3715 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3716 if (strcmp(word->data, r->literal) == 0)
3721 static int reserved_word(o_string *word, struct parse_context *ctx)
3723 #if ENABLE_HUSH_CASE
3724 static const struct reserved_combo reserved_match = {
3725 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3728 const struct reserved_combo *r;
3730 r = match_reserved_word(word);
3734 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3735 #if ENABLE_HUSH_CASE
3736 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3737 /* "case word IN ..." - IN part starts first match part */
3738 r = &reserved_match;
3741 if (r->flag == 0) { /* '!' */
3742 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3743 syntax("! ! command");
3744 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3746 ctx->ctx_inverted = 1;
3749 if (r->flag & FLAG_START) {
3750 struct parse_context *old;
3751 old = xmalloc(sizeof(*old));
3752 debug_printf_parse("push stack %p\n", old);
3753 *old = *ctx; /* physical copy */
3754 initialize_context(ctx);
3756 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3758 ctx->ctx_res_w = RES_SNTX;
3761 ctx->ctx_res_w = r->res;
3762 ctx->old_flag = r->flag;
3763 if (ctx->old_flag & FLAG_END) {
3764 struct parse_context *old;
3765 done_pipe(ctx, PIPE_SEQ);
3766 debug_printf_parse("pop stack %p\n", ctx->stack);
3768 old->command->group = ctx->list_head;
3769 old->command->grp_type = GRP_NORMAL;
3771 o_addstr(&old->as_string, ctx->as_string.data);
3772 o_free_unsafe(&ctx->as_string);
3773 old->command->group_as_string = xstrdup(old->as_string.data);
3774 debug_printf_parse("pop, remembering as:'%s'\n",
3775 old->command->group_as_string);
3777 *ctx = *old; /* physical copy */
3780 word->o_assignment = r->assignment_flag;
3785 /* Word is complete, look at it and update parsing context.
3786 * Normal return is 0. Syntax errors return 1.
3787 * Note: on return, word is reset, but not o_free'd!
3789 static int done_word(o_string *word, struct parse_context *ctx)
3791 struct command *command = ctx->command;
3793 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3794 if (word->length == 0 && word->nonnull == 0) {
3795 debug_printf_parse("done_word return 0: true null, ignored\n");
3798 /* If this word wasn't an assignment, next ones definitely
3799 * can't be assignments. Even if they look like ones. */
3800 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3801 && word->o_assignment != WORD_IS_KEYWORD
3803 word->o_assignment = NOT_ASSIGNMENT;
3805 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3806 command->assignment_cnt++;
3807 word->o_assignment = MAYBE_ASSIGNMENT;
3810 if (ctx->pending_redirect) {
3811 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3812 * only if run as "bash", not "sh" */
3813 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3815 * ...the word that follows the redirection operator
3816 * shall be subjected to tilde expansion, parameter expansion,
3817 * command substitution, arithmetic expansion, and quote
3818 * removal. Pathname expansion shall not be performed
3819 * on the word by a non-interactive shell; an interactive
3820 * shell may perform it, but shall do so only when
3821 * the expansion would result in one word."
3823 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3824 word->o_assignment = NOT_ASSIGNMENT;
3825 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3827 /* "{ echo foo; } echo bar" - bad */
3828 /* NB: bash allows e.g.:
3829 * if true; then { echo foo; } fi
3830 * while if false; then false; fi do break; done
3832 * while if false; then false; fi; do; break; done
3834 if (command->group) {
3836 debug_printf_parse("done_word return 1: syntax error, "
3837 "groups and arglists don't mix\n");
3841 #if ENABLE_HUSH_CASE
3842 if (ctx->ctx_dsemicolon
3843 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3845 /* already done when ctx_dsemicolon was set to 1: */
3846 /* ctx->ctx_res_w = RES_MATCH; */
3847 ctx->ctx_dsemicolon = 0;
3850 if (!command->argv /* if it's the first word... */
3851 #if ENABLE_HUSH_LOOPS
3852 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3853 && ctx->ctx_res_w != RES_IN
3856 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3857 if (reserved_word(word, ctx)) {
3859 debug_printf_parse("done_word return %d\n",
3860 (ctx->ctx_res_w == RES_SNTX));
3861 return (ctx->ctx_res_w == RES_SNTX);
3865 if (word->nonnull /* word had "xx" or 'xx' at least as part of it. */
3866 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3867 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3868 /* (otherwise it's known to be not empty and is already safe) */
3870 /* exclude "$@" - it can expand to no word despite "" */
3871 char *p = word->data;
3872 while (p[0] == SPECIAL_VAR_SYMBOL
3873 && (p[1] & 0x7f) == '@'
3874 && p[2] == SPECIAL_VAR_SYMBOL
3878 if (p == word->data || p[0] != '\0') {
3879 /* saw no "$@", or not only "$@" but some
3880 * real text is there too */
3881 /* insert "empty variable" reference, this makes
3882 * e.g. "", $empty"" etc to not disappear */
3883 o_addchr(word, SPECIAL_VAR_SYMBOL);
3884 o_addchr(word, SPECIAL_VAR_SYMBOL);
3887 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3888 debug_print_strings("word appended to argv", command->argv);
3892 ctx->pending_redirect = NULL;
3894 #if ENABLE_HUSH_LOOPS
3895 /* Force FOR to have just one word (variable name) */
3896 /* NB: basically, this makes hush see "for v in ..." syntax as if
3897 * as it is "for v; in ...". FOR and IN become two pipe structs
3899 if (ctx->ctx_res_w == RES_FOR) {
3900 //TODO: check that command->argv[0] is a valid variable name!
3901 done_pipe(ctx, PIPE_SEQ);
3904 #if ENABLE_HUSH_CASE
3905 /* Force CASE to have just one word */
3906 if (ctx->ctx_res_w == RES_CASE) {
3907 done_pipe(ctx, PIPE_SEQ);
3910 debug_printf_parse("done_word return 0\n");
3915 /* Peek ahead in the input to find out if we have a "&n" construct,
3916 * as in "2>&1", that represents duplicating a file descriptor.
3917 * Return: -3 if >&- "close fd" construct is seen,
3918 * -2 (syntax error), -1 if no & was seen, or the number found.
3921 #define redirect_dup_num(as_string, input) \
3922 redirect_dup_num(input)
3924 static int redirect_dup_num(o_string *as_string, struct in_str *input)
3932 ch = i_getch(input); /* get the & */
3933 nommu_addchr(as_string, ch);
3936 ch = i_getch(input);
3937 nommu_addchr(as_string, ch);
3938 return -3; /* "-" represents "close me" */
3942 while (ch != EOF && isdigit(ch)) {
3943 d = d*10 + (ch-'0');
3945 ch = i_getch(input);
3946 nommu_addchr(as_string, ch);
3951 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3953 bb_error_msg("ambiguous redirect");
3957 /* Return code is 0 normally, 1 if a syntax error is detected
3959 static int parse_redirect(struct parse_context *ctx,
3962 struct in_str *input)
3964 struct command *command = ctx->command;
3965 struct redir_struct *redir;
3966 struct redir_struct **redirp;
3970 if (style != REDIRECT_HEREDOC) {
3971 /* Check for a '2>&1' type redirect */
3972 dup_num = redirect_dup_num(&ctx->as_string, input);
3974 return 1; /* syntax error */
3976 int ch = i_peek(input);
3977 dup_num = (ch == '-');
3978 if (dup_num) { /* <<-... */
3979 ch = i_getch(input);
3980 nommu_addchr(&ctx->as_string, ch);
3983 /* <<[-] word is the same as <<[-]word */
3984 while (ch == ' ' || ch == '\t') {
3985 ch = i_getch(input);
3986 nommu_addchr(&ctx->as_string, ch);
3991 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
3992 int ch = i_peek(input);
3994 /* >|FILE redirect ("clobbering" >).
3995 * Since we do not support "set -o noclobber" yet,
3996 * >| and > are the same for now. Just eat |.
3998 ch = i_getch(input);
3999 nommu_addchr(&ctx->as_string, ch);
4003 /* Create a new redir_struct and append it to the linked list */
4004 redirp = &command->redirects;
4005 while ((redir = *redirp) != NULL) {
4006 redirp = &(redir->next);
4008 *redirp = redir = xzalloc(sizeof(*redir));
4009 /* redir->next = NULL; */
4010 /* redir->rd_filename = NULL; */
4011 redir->rd_type = style;
4012 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4014 debug_printf_parse("redirect type %d %s\n", redir->rd_fd, redir_table[style].descrip);
4016 redir->rd_dup = dup_num;
4017 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4018 /* Erik had a check here that the file descriptor in question
4019 * is legit; I postpone that to "run time"
4020 * A "-" representation of "close me" shows up as a -3 here */
4021 debug_printf_parse("duplicating redirect '%d>&%d'\n", redir->rd_fd, redir->rd_dup);
4023 /* Set ctx->pending_redirect, so we know what to do at the
4024 * end of the next parsed word. */
4025 ctx->pending_redirect = redir;
4030 /* If a redirect is immediately preceded by a number, that number is
4031 * supposed to tell which file descriptor to redirect. This routine
4032 * looks for such preceding numbers. In an ideal world this routine
4033 * needs to handle all the following classes of redirects...
4034 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4035 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4036 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4037 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4039 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4041 * ... If n is quoted, the number shall not be recognized as part of
4042 * the redirection expression. For example:
4044 * writes the character 2 into file a"
4045 * I am not sure we do it right (and not sure we care)
4047 * A -1 return means no valid number was found,
4048 * the caller should use the appropriate default for this redirection.
4050 static int redirect_opt_num(o_string *o)
4054 if (o->data == NULL)
4056 num = bb_strtou(o->data, NULL, 10);
4057 if (errno || num < 0)
4064 #define fetch_till_str(as_string, input, word, skip_tabs) \
4065 fetch_till_str(input, word, skip_tabs)
4067 static char *fetch_till_str(o_string *as_string,
4068 struct in_str *input,
4072 o_string heredoc = NULL_O_STRING;
4078 ch = i_getch(input);
4079 nommu_addchr(as_string, ch);
4081 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4082 heredoc.data[past_EOL] = '\0';
4083 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4084 return heredoc.data;
4087 o_addchr(&heredoc, ch);
4088 past_EOL = heredoc.length;
4091 ch = i_getch(input);
4092 nommu_addchr(as_string, ch);
4093 } while (skip_tabs && ch == '\t');
4094 } while (ch == '\n');
4097 o_free_unsafe(&heredoc);
4100 o_addchr(&heredoc, ch);
4101 nommu_addchr(as_string, ch);
4105 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4107 struct pipe *pi = ctx->list_head;
4111 struct command *cmd = pi->cmds;
4113 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4115 cmd->argv ? cmd->argv[0] : "NONE");
4116 for (i = 0; i < pi->num_cmds; i++) {
4117 struct redir_struct *redir = cmd->redirects;
4119 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4120 i, cmd->argv ? cmd->argv[0] : "NONE");
4122 if (redir->rd_type == REDIRECT_HEREDOC) {
4125 if (heredoc_cnt <= 0)
4126 return 1; /* error */
4127 redir->rd_type = REDIRECT_HEREDOC2;
4128 /* redir->dup is (ab)used to indicate <<- */
4129 p = fetch_till_str(&ctx->as_string, input,
4130 redir->rd_filename, redir->rd_dup);
4132 return 1; /* unexpected EOF */
4133 free(redir->rd_filename);
4134 redir->rd_filename = p;
4137 redir = redir->next;
4143 /* Should be 0. If it isn't, it's a parse error */
4149 #define parse_stream(pstring, input, end_trigger) \
4150 parse_stream(input, end_trigger)
4152 static struct pipe *parse_stream(char **pstring,
4153 struct in_str *input,
4155 static void parse_and_run_string(const char *s);
4157 #if ENABLE_HUSH_TICK
4158 static FILE *generate_stream_from_string(const char *s)
4161 int pid, channel[2];
4164 pid = BB_MMU ? fork() : vfork();
4166 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4168 if (pid == 0) { /* child */
4169 disable_restore_tty_pgrp_on_exit();
4170 /* Process substitution is not considered to be usual
4171 * 'command execution'.
4172 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4179 close(channel[0]); /* NB: close _first_, then move fd! */
4180 xmove_fd(channel[1], 1);
4181 /* Prevent it from trying to handle ctrl-z etc */
4182 USE_HUSH_JOB(G.run_list_level = 1;)
4184 reset_traps_to_defaults();
4185 parse_and_run_string(s);
4186 _exit(G.last_exitcode);
4188 /* We re-execute after vfork on NOMMU. This makes this script safe:
4189 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4190 * huge=`cat BIG` # was blocking here forever
4193 re_execute_shell(s, 0);
4198 enable_restore_tty_pgrp_on_exit();
4199 clean_up_after_re_execute();
4201 pf = fdopen(channel[0], "r");
4205 /* Return code is exit status of the process that is run. */
4206 static int process_command_subs(o_string *dest, const char *s)
4209 struct in_str pipe_str;
4212 pf = generate_stream_from_string(s);
4215 close_on_exec_on(fileno(pf));
4217 /* Now send results of command back into original context */
4218 setup_file_in_str(&pipe_str, pf);
4220 while ((ch = i_getch(&pipe_str)) != EOF) {
4226 o_addchr(dest, '\n');
4229 o_addQchr(dest, ch);
4232 debug_printf("done reading from pipe, pclose()ing\n");
4233 /* Note: we got EOF, and we just close the read end of the pipe.
4234 * We do not wait for the `cmd` child to terminate. bash and ash do.
4236 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4237 * `false`; echo $? - bash outputs "1"
4240 debug_printf("closed FILE from child. return 0\n");
4245 static int parse_group(o_string *dest, struct parse_context *ctx,
4246 struct in_str *input, int ch)
4248 /* dest contains characters seen prior to ( or {.
4249 * Typically it's empty, but for function defs,
4250 * it contains function name (without '()'). */
4251 struct pipe *pipe_list;
4253 struct command *command = ctx->command;
4255 debug_printf_parse("parse_group entered\n");
4256 #if ENABLE_HUSH_FUNCTIONS
4257 if (ch == 'F') { /* function definition? */
4258 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4259 //command->fname = dest->data;
4260 command->grp_type = GRP_FUNCTION;
4261 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4262 memset(dest, 0, sizeof(*dest));
4265 if (command->argv /* word [word](... */
4266 || dest->length /* word(... */
4267 || dest->nonnull /* ""(... */
4270 debug_printf_parse("parse_group return 1: "
4271 "syntax error, groups and arglists don't mix\n");
4277 command->grp_type = GRP_SUBSHELL;
4281 char *as_string = NULL;
4283 pipe_list = parse_stream(&as_string, input, endch);
4286 o_addstr(&ctx->as_string, as_string);
4288 /* empty ()/{} or parse error? */
4289 if (!pipe_list || pipe_list == ERR_PTR) {
4294 debug_printf_parse("parse_group return 1: "
4295 "parse_stream returned %p\n", pipe_list);
4298 command->group = pipe_list;
4300 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4301 command->group_as_string = as_string;
4302 debug_printf_parse("end of group, remembering as:'%s'\n",
4303 command->group_as_string);
4306 debug_printf_parse("parse_group return 0\n");
4308 /* command remains "open", available for possible redirects */
4311 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4312 /* Subroutines for copying $(...) and `...` things */
4313 static void add_till_backquote(o_string *dest, struct in_str *input);
4315 static void add_till_single_quote(o_string *dest, struct in_str *input)
4318 int ch = i_getch(input);
4326 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4327 static void add_till_double_quote(o_string *dest, struct in_str *input)
4330 int ch = i_getch(input);
4333 if (ch == '\\') { /* \x. Copy both chars. */
4335 ch = i_getch(input);
4341 add_till_backquote(dest, input);
4345 //if (ch == '$') ...
4348 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4350 * "Within the backquoted style of command substitution, backslash
4351 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4352 * The search for the matching backquote shall be satisfied by the first
4353 * backquote found without a preceding backslash; during this search,
4354 * if a non-escaped backquote is encountered within a shell comment,
4355 * a here-document, an embedded command substitution of the $(command)
4356 * form, or a quoted string, undefined results occur. A single-quoted
4357 * or double-quoted string that begins, but does not end, within the
4358 * "`...`" sequence produces undefined results."
4360 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4362 static void add_till_backquote(o_string *dest, struct in_str *input)
4365 int ch = i_getch(input);
4368 if (ch == '\\') { /* \x. Copy both chars unless it is \` */
4369 int ch2 = i_getch(input);
4370 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4379 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4380 * quoting and nested ()s.
4381 * "With the $(command) style of command substitution, all characters
4382 * following the open parenthesis to the matching closing parenthesis
4383 * constitute the command. Any valid shell script can be used for command,
4384 * except a script consisting solely of redirections which produces
4385 * unspecified results."
4387 * echo $(echo '(TEST)' BEST) (TEST) BEST
4388 * echo $(echo 'TEST)' BEST) TEST) BEST
4389 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4391 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4395 int ch = i_getch(input);
4404 if (i_peek(input) == ')') {
4412 add_till_single_quote(dest, input);
4417 add_till_double_quote(dest, input);
4421 if (ch == '\\') { /* \x. Copy verbatim. Important for \(, \) */
4422 ch = i_getch(input);
4430 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4432 /* Return code: 0 for OK, 1 for syntax error */
4434 #define handle_dollar(as_string, dest, input) \
4435 handle_dollar(dest, input)
4437 static int handle_dollar(o_string *as_string,
4439 struct in_str *input)
4442 int ch = i_peek(input); /* first character after the $ */
4443 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4445 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4447 ch = i_getch(input);
4448 nommu_addchr(as_string, ch);
4450 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4452 debug_printf_parse(": '%c'\n", ch);
4453 o_addchr(dest, ch | quote_mask);
4456 if (!isalnum(ch) && ch != '_')
4458 ch = i_getch(input);
4459 nommu_addchr(as_string, ch);
4461 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4462 } else if (isdigit(ch)) {
4464 ch = i_getch(input);
4465 nommu_addchr(as_string, ch);
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 debug_printf_parse(": '%c'\n", ch);
4468 o_addchr(dest, ch | quote_mask);
4469 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4470 } else switch (ch) {
4472 case '!': /* last bg pid */
4473 case '?': /* last exit code */
4474 case '#': /* number of args */
4475 case '*': /* args */
4476 case '@': /* args */
4477 goto make_one_char_var;
4479 bool first_char, all_digits;
4481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4482 ch = i_getch(input);
4483 nommu_addchr(as_string, ch);
4484 /* XXX maybe someone will try to escape the '}' */
4489 ch = i_getch(input);
4490 nommu_addchr(as_string, ch);
4496 /* ${#var}: length of var contents */
4498 else if (isdigit(ch)) {
4505 && ( (all_digits && !isdigit(ch))
4506 || (!all_digits && !isalnum(ch) && ch != '_')
4509 /* handle parameter expansions
4510 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4515 case ':': /* null modifier */
4516 if (expansion == 0) {
4517 debug_printf_parse(": null modifier\n");
4522 case '#': /* remove prefix */
4523 case '%': /* remove suffix */
4524 if (expansion == 0) {
4525 debug_printf_parse(": remove suffix/prefix\n");
4530 case '-': /* default value */
4531 case '=': /* assign default */
4532 case '+': /* alternative */
4533 case '?': /* error indicate */
4534 debug_printf_parse(": parameter expansion\n");
4539 syntax("unterminated ${name}");
4540 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4545 debug_printf_parse(": '%c'\n", ch);
4546 o_addchr(dest, ch | quote_mask);
4550 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4553 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4558 ch = i_getch(input);
4559 nommu_addchr(as_string, ch);
4560 # if ENABLE_SH_MATH_SUPPORT
4561 if (i_peek(input) == '(') {
4562 ch = i_getch(input);
4563 nommu_addchr(as_string, ch);
4564 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4565 o_addchr(dest, /*quote_mask |*/ '+');
4569 add_till_closing_paren(dest, input, true);
4572 o_addstr(as_string, dest->data + pos);
4573 o_addchr(as_string, ')');
4574 o_addchr(as_string, ')');
4577 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4581 # if ENABLE_HUSH_TICK
4582 //int pos = dest->length;
4583 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4584 o_addchr(dest, quote_mask | '`');
4588 add_till_closing_paren(dest, input, false);
4591 o_addstr(as_string, dest->data + pos);
4592 o_addchr(as_string, '`');
4595 //debug_printf_subst("SUBST RES2 '%s'\n", dest->data + pos);
4596 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4602 ch = i_getch(input);
4603 nommu_addchr(as_string, ch);
4605 if (isalnum(ch)) { /* it's $_name or $_123 */
4611 /* $_ Shell or shell script name; or last cmd name */
4612 /* $- Option flags set by set builtin or shell options (-i etc) */
4614 o_addQchr(dest, '$');
4616 debug_printf_parse("handle_dollar return 0\n");
4621 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4622 parse_stream_dquoted(dest, input, dquote_end)
4624 static int parse_stream_dquoted(o_string *as_string,
4626 struct in_str *input,
4633 ch = i_getch(input);
4635 nommu_addchr(as_string, ch);
4636 if (ch == dquote_end) { /* may be only '"' or EOF */
4638 if (dest->o_assignment == NOT_ASSIGNMENT)
4639 dest->o_escape ^= 1;
4640 debug_printf_parse("parse_stream_dquoted return 0\n");
4644 syntax("unterminated \"");
4645 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4650 next = i_peek(input);
4652 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4653 ch, ch, dest->o_escape);
4657 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4661 * "The backslash retains its special meaning [in "..."]
4662 * only when followed by one of the following characters:
4663 * $, `, ", \, or <newline>. A double quote may be quoted
4664 * within double quotes by preceding it with a backslash.
4665 * If enabled, history expansion will be performed unless
4666 * an ! appearing in double quotes is escaped using
4667 * a backslash. The backslash preceding the ! is not removed."
4669 if (strchr("$`\"\\", next) != NULL) {
4670 o_addqchr(dest, i_getch(input));
4672 o_addqchr(dest, '\\');
4677 if (handle_dollar(as_string, dest, input) != 0) {
4678 debug_printf_parse("parse_stream_dquoted return 1: "
4679 "handle_dollar returned non-0\n");
4684 #if ENABLE_HUSH_TICK
4686 //int pos = dest->length;
4687 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4688 o_addchr(dest, 0x80 | '`');
4689 add_till_backquote(dest, input);
4690 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4691 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4695 o_addQchr(dest, ch);
4697 && (dest->o_assignment == MAYBE_ASSIGNMENT
4698 || dest->o_assignment == WORD_IS_KEYWORD)
4699 && is_assignment(dest->data)
4701 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4707 * Scan input until EOF or end_trigger char.
4708 * Return a list of pipes to execute, or NULL on EOF
4709 * or if end_trigger character is met.
4710 * On syntax error, exit is shell is not interactive,
4711 * reset parsing machinery and start parsing anew,
4712 * or return ERR_PTR.
4714 static struct pipe *parse_stream(char **pstring,
4715 struct in_str *input,
4718 struct parse_context ctx;
4719 o_string dest = NULL_O_STRING;
4723 /* Double-quote state is handled in the state variable is_in_dquote.
4724 * A single-quote triggers a bypass of the main loop until its mate is
4725 * found. When recursing, quote state is passed in via dest->o_escape.
4727 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4728 end_trigger ? : 'X');
4730 G.ifs = get_local_var_value("IFS");
4735 #if ENABLE_HUSH_INTERACTIVE
4736 input->promptmode = 0; /* PS1 */
4738 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4739 initialize_context(&ctx);
4744 const char *is_special;
4748 redir_type redir_style;
4751 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4754 /* We reached closing '"' */
4757 ch = i_getch(input);
4758 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4759 ch, ch, dest.o_escape);
4764 syntax("unterminated here document");
4767 if (done_word(&dest, &ctx)) {
4771 done_pipe(&ctx, PIPE_SEQ);
4773 /* If we got nothing... */
4774 // TODO: test script consisting of just "&"
4775 if (pi->num_cmds == 0
4776 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4778 free_pipe_list(pi, 0);
4781 debug_printf_parse("parse_stream return %p\n", pi);
4783 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4785 *pstring = ctx.as_string.data;
4787 o_free_unsafe(&ctx.as_string);
4791 nommu_addchr(&ctx.as_string, ch);
4792 is_ifs = strchr(G.ifs, ch);
4793 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4794 "\\$\"" USE_HUSH_TICK("`") /* always special */
4797 if (!is_special && !is_ifs) { /* ordinary char */
4798 o_addQchr(&dest, ch);
4799 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4800 || dest.o_assignment == WORD_IS_KEYWORD)
4802 && is_assignment(dest.data)
4804 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4810 if (done_word(&dest, &ctx)) {
4814 #if ENABLE_HUSH_CASE
4815 /* "case ... in <newline> word) ..." -
4816 * newlines are ignored (but ';' wouldn't be) */
4817 if (ctx.command->argv == NULL
4818 && ctx.ctx_res_w == RES_MATCH
4823 /* Treat newline as a command separator. */
4824 done_pipe(&ctx, PIPE_SEQ);
4825 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4827 if (fetch_heredocs(heredoc_cnt, &ctx, input))
4831 dest.o_assignment = MAYBE_ASSIGNMENT;
4833 /* note: if (is_ifs) continue;
4834 * will still trigger for us */
4837 if (end_trigger && end_trigger == ch
4838 && (heredoc_cnt == 0 || end_trigger != ';')
4840 //TODO: disallow "{ cmd }" without semicolon
4842 /* This is technically valid:
4843 * { cat <<HERE; }; echo Ok
4848 * but we don't support this.
4849 * We require heredoc to be in enclosing {}/(),
4852 syntax("unterminated here document");
4855 if (done_word(&dest, &ctx)) {
4858 done_pipe(&ctx, PIPE_SEQ);
4859 dest.o_assignment = MAYBE_ASSIGNMENT;
4860 /* Do we sit outside of any if's, loops or case's? */
4862 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4864 debug_printf_parse("parse_stream return %p: "
4865 "end_trigger char found\n",
4869 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4871 *pstring = ctx.as_string.data;
4873 o_free_unsafe(&ctx.as_string);
4875 return ctx.list_head;
4881 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
4882 /* ch is a special char and thus this word
4883 * cannot be an assignment */
4884 dest.o_assignment = NOT_ASSIGNMENT;
4889 next = i_peek(input);
4894 if (dest.length == 0) {
4897 if (ch == EOF || ch == '\n')
4900 /* note: we do not add it to &ctx.as_string */
4902 //TODO: go back one char?
4903 nommu_addchr(&ctx.as_string, '\n');
4905 o_addQchr(&dest, ch);
4913 o_addchr(&dest, '\\');
4914 ch = i_getch(input);
4915 o_addchr(&dest, ch);
4916 nommu_addchr(&ctx.as_string, ch);
4919 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
4920 debug_printf_parse("parse_stream parse error: "
4921 "handle_dollar returned non-0\n");
4928 ch = i_getch(input);
4930 syntax("unterminated '");
4933 nommu_addchr(&ctx.as_string, ch);
4936 if (dest.o_assignment == NOT_ASSIGNMENT)
4937 o_addqchr(&dest, ch);
4939 o_addchr(&dest, ch);
4944 is_in_dquote ^= 1; /* invert */
4945 if (dest.o_assignment == NOT_ASSIGNMENT)
4948 #if ENABLE_HUSH_TICK
4950 //int pos = dest.length;
4951 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4952 o_addchr(&dest, '`');
4953 add_till_backquote(&dest, input);
4954 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4955 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4960 redir_fd = redirect_opt_num(&dest);
4961 if (done_word(&dest, &ctx)) {
4964 redir_style = REDIRECT_OVERWRITE;
4966 redir_style = REDIRECT_APPEND;
4967 ch = i_getch(input);
4968 nommu_addchr(&ctx.as_string, ch);
4971 else if (next == '(') {
4972 syntax(">(process) not supported");
4976 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4980 redir_fd = redirect_opt_num(&dest);
4981 if (done_word(&dest, &ctx)) {
4984 redir_style = REDIRECT_INPUT;
4986 redir_style = REDIRECT_HEREDOC;
4988 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4989 ch = i_getch(input);
4990 nommu_addchr(&ctx.as_string, ch);
4991 } else if (next == '>') {
4992 redir_style = REDIRECT_IO;
4993 ch = i_getch(input);
4994 nommu_addchr(&ctx.as_string, ch);
4997 else if (next == '(') {
4998 syntax("<(process) not supported");
5002 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5006 #if ENABLE_HUSH_CASE
5009 if (done_word(&dest, &ctx)) {
5012 done_pipe(&ctx, PIPE_SEQ);
5013 #if ENABLE_HUSH_CASE
5014 /* Eat multiple semicolons, detect
5015 * whether it means something special */
5020 ch = i_getch(input);
5021 nommu_addchr(&ctx.as_string, ch);
5022 if (ctx.ctx_res_w == RES_CASEI) {
5023 ctx.ctx_dsemicolon = 1;
5024 ctx.ctx_res_w = RES_MATCH;
5030 /* We just finished a cmd. New one may start
5031 * with an assignment */
5032 dest.o_assignment = MAYBE_ASSIGNMENT;
5035 if (done_word(&dest, &ctx)) {
5039 ch = i_getch(input);
5040 nommu_addchr(&ctx.as_string, ch);
5041 done_pipe(&ctx, PIPE_AND);
5043 done_pipe(&ctx, PIPE_BG);
5047 if (done_word(&dest, &ctx)) {
5050 #if ENABLE_HUSH_CASE
5051 if (ctx.ctx_res_w == RES_MATCH)
5052 break; /* we are in case's "word | word)" */
5054 if (next == '|') { /* || */
5055 ch = i_getch(input);
5056 nommu_addchr(&ctx.as_string, ch);
5057 done_pipe(&ctx, PIPE_OR);
5059 /* we could pick up a file descriptor choice here
5060 * with redirect_opt_num(), but bash doesn't do it.
5061 * "echo foo 2| cat" yields "foo 2". */
5066 #if ENABLE_HUSH_CASE
5067 /* "case... in [(]word)..." - skip '(' */
5068 if (ctx.ctx_res_w == RES_MATCH
5069 && ctx.command->argv == NULL /* not (word|(... */
5070 && dest.length == 0 /* not word(... */
5071 && dest.nonnull == 0 /* not ""(... */
5076 #if ENABLE_HUSH_FUNCTIONS
5077 if (dest.length != 0 /* not just () but word() */
5078 && dest.nonnull == 0 /* not a"b"c() */
5079 && ctx.command->argv == NULL /* it's the first word */
5080 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5081 && i_peek(input) == ')'
5082 && !match_reserved_word(&dest)
5084 bb_error_msg("seems like a function definition");
5086 //if !BB_MMU o_addchr(&ctx.as_string...
5088 //TODO: do it properly.
5089 ch = i_getch(input);
5090 } while (ch == ' ' || ch == '\n');
5092 syntax("was expecting {");
5095 ch = 'F'; /* magic value */
5099 if (parse_group(&dest, &ctx, input, ch) != 0) {
5104 #if ENABLE_HUSH_CASE
5105 if (ctx.ctx_res_w == RES_MATCH)
5109 /* proper use of this character is caught by end_trigger:
5110 * if we see {, we call parse_group(..., end_trigger='}')
5111 * and it will match } earlier (not here). */
5112 syntax("unexpected } or )");
5116 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5122 struct parse_context *pctx;
5123 IF_HAS_KEYWORDS(struct parse_context *p2;)
5125 /* Clean up allocated tree.
5126 * Samples for finding leaks on syntax error recovery path.
5127 * Run them from interactive shell, watch pmap `pidof hush`.
5128 * while if false; then false; fi do break; done
5130 * while if false; then false; fi; do break; fi
5131 * Samples to catch leaks at execution:
5132 * while if (true | {true;}); then echo ok; fi; do break; done
5133 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5137 /* Update pipe/command counts,
5138 * otherwise freeing may miss some */
5139 done_pipe(pctx, PIPE_SEQ);
5140 debug_printf_clean("freeing list %p from ctx %p\n",
5141 pctx->list_head, pctx);
5142 debug_print_tree(pctx->list_head, 0);
5143 free_pipe_list(pctx->list_head, 0);
5144 debug_printf_clean("freed list %p\n", pctx->list_head);
5146 o_free_unsafe(&pctx->as_string);
5148 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5152 IF_HAS_KEYWORDS(pctx = p2;)
5153 } while (HAS_KEYWORDS && pctx);
5154 /* Free text, clear all dest fields */
5156 /* If we are not in top-level parse, we return,
5157 * our caller will propagate error.
5159 if (end_trigger != ';') {
5166 /* Discard cached input, force prompt */
5168 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5173 /* Executing from string: eval, sh -c '...'
5174 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5175 * end_trigger controls how often we stop parsing
5176 * NUL: parse all, execute, return
5177 * ';': parse till ';' or newline, execute, repeat till EOF
5179 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5182 struct pipe *pipe_list;
5184 pipe_list = parse_stream(NULL, inp, end_trigger);
5185 if (!pipe_list) /* EOF */
5187 debug_print_tree(pipe_list, 0);
5188 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5189 run_and_free_list(pipe_list);
5193 static void parse_and_run_string(const char *s)
5195 struct in_str input;
5196 setup_string_in_str(&input, s);
5197 parse_and_run_stream(&input, '\0');
5200 static void parse_and_run_file(FILE *f)
5202 struct in_str input;
5203 setup_file_in_str(&input, f);
5204 parse_and_run_stream(&input, ';');
5207 /* Called a few times only (or even once if "sh -c") */
5208 static void block_signals(int second_time)
5213 mask = (1 << SIGQUIT);
5214 if (G_interactive_fd) {
5218 //TODO | (1 << SIGHUP)
5220 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5225 G.non_DFL_mask = mask;
5228 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5232 sigaddset(&G.blocked_set, sig);
5236 sigdelset(&G.blocked_set, SIGCHLD);
5238 sigprocmask(SIG_SETMASK, &G.blocked_set,
5239 second_time ? NULL : &G.inherited_set);
5240 /* POSIX allows shell to re-enable SIGCHLD
5241 * even if it was SIG_IGN on entry */
5242 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5244 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5249 static void maybe_set_to_sigexit(int sig)
5251 void (*handler)(int);
5252 /* non_DFL_mask'ed signals are, well, masked,
5253 * no need to set handler for them.
5255 if (!((G.non_DFL_mask >> sig) & 1)) {
5256 handler = signal(sig, sigexit);
5257 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5258 signal(sig, handler);
5261 /* Set handlers to restore tty pgrp and exit */
5262 static void set_fatal_handlers(void)
5264 /* We _must_ restore tty pgrp on fatal signals */
5266 maybe_set_to_sigexit(SIGILL );
5267 maybe_set_to_sigexit(SIGFPE );
5268 maybe_set_to_sigexit(SIGBUS );
5269 maybe_set_to_sigexit(SIGSEGV);
5270 maybe_set_to_sigexit(SIGTRAP);
5271 } /* else: hush is perfect. what SEGV? */
5272 maybe_set_to_sigexit(SIGABRT);
5273 /* bash 3.2 seems to handle these just like 'fatal' ones */
5274 maybe_set_to_sigexit(SIGPIPE);
5275 maybe_set_to_sigexit(SIGALRM);
5276 //TODO: disable and move down when proper SIGHUP handling is added
5277 maybe_set_to_sigexit(SIGHUP );
5278 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5279 * if we aren't interactive... but in this case
5280 * we never want to restore pgrp on exit, and this fn is not called */
5281 /*maybe_set_to_sigexit(SIGTERM);*/
5282 /*maybe_set_to_sigexit(SIGINT );*/
5286 static int set_mode(const char cstate, const char mode)
5288 int state = (cstate == '-' ? 1 : 0);
5290 case 'n': G.fake_mode = state; break;
5291 case 'x': /*G.debug_mode = state;*/ break;
5292 default: return EXIT_FAILURE;
5294 return EXIT_SUCCESS;
5297 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5298 int hush_main(int argc, char **argv)
5300 static const struct variable const_shell_ver = {
5302 .varstr = (char*)hush_version_str,
5303 .max_len = 1, /* 0 can provoke free(name) */
5307 int signal_mask_is_inited = 0;
5310 struct variable *cur_var;
5313 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5314 G.last_exitcode = EXIT_SUCCESS;
5316 G.argv0_for_re_execing = argv[0];
5318 /* Deal with HUSH_VERSION */
5319 G.shell_ver = const_shell_ver; /* copying struct here */
5320 G.top_var = &G.shell_ver;
5321 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5322 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5323 /* Initialize our shell local variables with the values
5324 * currently living in the environment */
5325 cur_var = G.top_var;
5328 char *value = strchr(*e, '=');
5329 if (value) { /* paranoia */
5330 cur_var->next = xzalloc(sizeof(*cur_var));
5331 cur_var = cur_var->next;
5332 cur_var->varstr = *e;
5333 cur_var->max_len = strlen(*e);
5334 cur_var->flg_export = 1;
5338 debug_printf_env("putenv '%s'\n", hush_version_str);
5339 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5340 #if ENABLE_FEATURE_EDITING
5341 G.line_input_state = new_line_input_t(FOR_SHELL);
5343 G.global_argc = argc;
5344 G.global_argv = argv;
5345 /* Initialize some more globals to non-zero values */
5347 #if ENABLE_HUSH_INTERACTIVE
5348 if (ENABLE_FEATURE_EDITING)
5349 cmdedit_set_initial_prompt();
5353 /* Shell is non-interactive at first. We need to call
5354 * block_signals(0) if we are going to execute "sh <script>",
5355 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5356 * If we later decide that we are interactive, we run block_signals(0)
5357 * (or re-run block_signals(1) if we ran block_signals(0) before)
5358 * in order to intercept (more) signals.
5362 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5364 opt = getopt(argc, argv, "c:xins"
5374 G.root_pid = getpid();
5375 G.global_argv = argv + optind;
5376 if (!argv[optind]) {
5377 /* -c 'script' (no params): prevent empty $0 */
5378 *--G.global_argv = argv[0];
5380 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5381 G.global_argc = argc - optind;
5382 block_signals(0); /* 0: called 1st time */
5383 parse_and_run_string(optarg);
5386 /* Well, we cannot just declare interactiveness,
5387 * we have to have some stuff (ctty, etc) */
5388 /* G_interactive_fd++; */
5391 /* "-s" means "read from stdin", but this is how we always
5392 * operate, so simply do nothing here. */
5395 case '<': /* "big heredoc" support */
5396 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5399 G.root_pid = bb_strtou(optarg, &optarg, 16);
5401 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5403 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5404 # if ENABLE_HUSH_LOOPS
5406 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5411 set_local_var(xstrdup(optarg), 0, opt == 'R');
5416 if (!set_mode('-', opt))
5420 fprintf(stderr, "Usage: sh [FILE]...\n"
5421 " or: sh -c command [args]...\n\n");
5427 } /* option parsing loop */
5430 G.root_pid = getpid();
5432 /* If we are login shell... */
5433 if (argv[0] && argv[0][0] == '-') {
5435 /* XXX what should argv be while sourcing /etc/profile? */
5436 debug_printf("sourcing /etc/profile\n");
5437 input = fopen_for_read("/etc/profile");
5438 if (input != NULL) {
5439 close_on_exec_on(fileno(input));
5440 block_signals(0); /* 0: called 1st time */
5441 signal_mask_is_inited = 1;
5442 parse_and_run_file(input);
5445 /* bash: after sourcing /etc/profile,
5446 * tries to source (in the given order):
5447 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5448 * stopping of first found. --noprofile turns this off.
5449 * bash also sources ~/.bash_logout on exit.
5450 * If called as sh, skips .bash_XXX files.
5457 * "bash <script>" (which is never interactive (unless -i?))
5458 * sources $BASH_ENV here (without scanning $PATH).
5459 * If called as sh, does the same but with $ENV.
5461 debug_printf("running script '%s'\n", argv[optind]);
5462 G.global_argv = argv + optind;
5463 G.global_argc = argc - optind;
5464 input = xfopen_for_read(argv[optind]);
5465 close_on_exec_on(fileno(input));
5466 if (!signal_mask_is_inited)
5467 block_signals(0); /* 0: called 1st time */
5468 parse_and_run_file(input);
5469 #if ENABLE_FEATURE_CLEAN_UP
5475 /* Up to here, shell was non-interactive. Now it may become one.
5476 * NB: don't forget to (re)run block_signals(0/1) as needed.
5479 /* A shell is interactive if the '-i' flag was given, or if all of
5480 * the following conditions are met:
5482 * no arguments remaining or the -s flag given
5483 * standard input is a terminal
5484 * standard output is a terminal
5485 * Refer to Posix.2, the description of the 'sh' utility.
5488 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5489 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5490 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5491 //TODO: "interactive" and "have job control" are two different things.
5492 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5493 //should stay on! Currently, we mix these into one.
5494 if (G.saved_tty_pgrp >= 0) {
5495 /* try to dup stdin to high fd#, >= 255 */
5496 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5497 if (G_interactive_fd < 0) {
5498 /* try to dup to any fd */
5499 G_interactive_fd = dup(STDIN_FILENO);
5500 if (G_interactive_fd < 0)
5502 G_interactive_fd = 0;
5504 // TODO: track & disallow any attempts of user
5505 // to (inadvertently) close/redirect it
5508 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5509 if (G_interactive_fd) {
5512 /* We are indeed interactive shell, and we will perform
5513 * job control. Setting up for that. */
5515 close_on_exec_on(G_interactive_fd);
5516 /* If we were run as 'hush &', sleep until we are
5517 * in the foreground (tty pgrp == our pgrp).
5518 * If we get started under a job aware app (like bash),
5519 * make sure we are now in charge so we don't fight over
5520 * who gets the foreground */
5522 shell_pgrp = getpgrp();
5523 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5524 if (G.saved_tty_pgrp == shell_pgrp)
5526 /* send TTIN to ourself (should stop us) */
5527 kill(- shell_pgrp, SIGTTIN);
5529 /* Block some signals */
5530 block_signals(signal_mask_is_inited);
5531 /* Set other signals to restore saved_tty_pgrp */
5532 set_fatal_handlers();
5533 /* Put ourselves in our own process group */
5534 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5535 /* Grab control of the terminal */
5536 tcsetpgrp(G_interactive_fd, getpid());
5537 /* -1 is special - makes xfuncs longjmp, not exit
5538 * (we reset die_sleep = 0 whereever we [v]fork) */
5539 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5540 if (setjmp(die_jmp)) {
5541 /* xfunc has failed! die die die */
5542 hush_exit(xfunc_error_retval);
5544 } else if (!signal_mask_is_inited) {
5545 block_signals(0); /* 0: called 1st time */
5546 } /* else: block_signals(0) was done before */
5547 #elif ENABLE_HUSH_INTERACTIVE
5548 /* No job control compiled in, only prompt/line editing */
5549 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5550 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5551 if (G_interactive_fd < 0) {
5552 /* try to dup to any fd */
5553 G_interactive_fd = dup(STDIN_FILENO);
5554 if (G_interactive_fd < 0)
5556 G_interactive_fd = 0;
5559 if (G_interactive_fd) {
5560 close_on_exec_on(G_interactive_fd);
5561 block_signals(signal_mask_is_inited);
5562 } else if (!signal_mask_is_inited) {
5566 /* We have interactiveness code disabled */
5567 if (!signal_mask_is_inited) {
5572 * if interactive but not a login shell, sources ~/.bashrc
5573 * (--norc turns this off, --rcfile <file> overrides)
5576 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5577 printf("\n\n%s hush - the humble shell\n", bb_banner);
5578 printf("Enter 'help' for a list of built-in commands.\n\n");
5581 parse_and_run_file(stdin);
5584 #if ENABLE_FEATURE_CLEAN_UP
5585 if (G.cwd != bb_msg_unknown)
5587 cur_var = G.top_var->next;
5589 struct variable *tmp = cur_var;
5590 if (!cur_var->max_len)
5591 free(cur_var->varstr);
5592 cur_var = cur_var->next;
5596 hush_exit(G.last_exitcode);
5601 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5602 int lash_main(int argc, char **argv)
5604 //bb_error_msg("lash is deprecated, please use hush instead");
5605 return hush_main(argc, argv);
5613 static int builtin_trap(char **argv)
5620 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5624 /* No args: print all trapped. This isn't 100% correct as we
5625 * should be escaping the cmd so that it can be pasted back in
5627 for (i = 0; i < NSIG; ++i)
5629 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5630 return EXIT_SUCCESS;
5635 /* If first arg is decimal: reset all specified signals */
5636 sig = bb_strtou(*argv, NULL, 10);
5642 sig = get_signum(*argv++);
5643 if (sig < 0 || sig >= NSIG) {
5645 /* Mimic bash message exactly */
5646 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5651 G.traps[sig] = xstrdup(new_cmd);
5653 debug_printf("trap: setting SIG%s (%i) to '%s'",
5654 get_signame(sig), sig, G.traps[sig]);
5656 /* There is no signal for 0 (EXIT) */
5661 sigaddset(&G.blocked_set, sig);
5663 /* There was a trap handler, we are removing it
5664 * (if sig has non-DFL handling,
5665 * we don't need to do anything) */
5666 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5668 sigdelset(&G.blocked_set, sig);
5670 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5675 /* First arg is "-": reset all specified to default */
5676 /* First arg is "": ignore all specified */
5677 /* Everything else: execute first arg upon signal */
5679 bb_error_msg("trap: invalid arguments");
5680 return EXIT_FAILURE;
5682 if (NOT_LONE_DASH(*argv))
5688 static int builtin_true(char **argv UNUSED_PARAM)
5693 static int builtin_test(char **argv)
5700 return test_main(argc, argv - argc);
5703 static int builtin_echo(char **argv)
5710 return echo_main(argc, argv - argc);
5713 static int builtin_eval(char **argv)
5715 int rcode = EXIT_SUCCESS;
5718 char *str = expand_strvec_to_string(argv);
5720 * eval "echo Hi; done" ("done" is syntax error):
5721 * "echo Hi" will not execute too.
5723 parse_and_run_string(str);
5725 rcode = G.last_exitcode;
5730 static int builtin_cd(char **argv)
5732 const char *newdir = argv[1];
5733 if (newdir == NULL) {
5734 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5735 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5737 newdir = getenv("HOME") ? : "/";
5739 if (chdir(newdir)) {
5740 /* Mimic bash message exactly */
5741 bb_perror_msg("cd: %s", newdir);
5742 return EXIT_FAILURE;
5745 return EXIT_SUCCESS;
5748 static int builtin_exec(char **argv)
5750 if (*++argv == NULL)
5751 return EXIT_SUCCESS; /* bash does this */
5756 // FIXME: if exec fails, bash does NOT exit! We do...
5757 pseudo_exec_argv(&dummy, argv, 0, NULL);
5762 static int builtin_exit(char **argv)
5764 debug_printf_exec("%s()\n", __func__);
5765 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5766 //puts("exit"); /* bash does it */
5767 // TODO: warn if we have background jobs: "There are stopped jobs"
5768 // On second consecutive 'exit', exit anyway.
5769 if (*++argv == NULL)
5770 hush_exit(G.last_exitcode);
5771 /* mimic bash: exit 123abc == exit 255 + error msg */
5772 xfunc_error_retval = 255;
5773 /* bash: exit -2 == exit 254, no error msg */
5774 hush_exit(xatoi(*argv) & 0xff);
5777 static int builtin_export(char **argv)
5779 if (*++argv == NULL) {
5781 // ash emits: export VAR='VAL'
5782 // bash: declare -x VAR="VAL"
5783 // (both also escape as needed (quotes, $, etc))
5788 return EXIT_SUCCESS;
5795 value = strchr(name, '=');
5797 /* They are exporting something without a =VALUE */
5798 struct variable *var;
5800 var = get_local_var(name);
5802 var->flg_export = 1;
5803 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5804 putenv(var->varstr);
5806 /* bash does not return an error when trying to export
5807 * an undefined variable. Do likewise. */
5810 set_local_var(xstrdup(name), 1, 0);
5813 return EXIT_SUCCESS;
5817 /* built-in 'fg' and 'bg' handler */
5818 static int builtin_fg_bg(char **argv)
5823 if (!G_interactive_fd)
5824 return EXIT_FAILURE;
5825 /* If they gave us no args, assume they want the last backgrounded task */
5827 for (pi = G.job_list; pi; pi = pi->next) {
5828 if (pi->jobid == G.last_jobid) {
5832 bb_error_msg("%s: no current job", argv[0]);
5833 return EXIT_FAILURE;
5835 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5836 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5837 return EXIT_FAILURE;
5839 for (pi = G.job_list; pi; pi = pi->next) {
5840 if (pi->jobid == jobnum) {
5844 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5845 return EXIT_FAILURE;
5847 // TODO: bash prints a string representation
5848 // of job being foregrounded (like "sleep 1 | cat")
5849 if (argv[0][0] == 'f') {
5850 /* Put the job into the foreground. */
5851 tcsetpgrp(G_interactive_fd, pi->pgrp);
5854 /* Restart the processes in the job */
5855 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5856 for (i = 0; i < pi->num_cmds; i++) {
5857 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5858 pi->cmds[i].is_stopped = 0;
5860 pi->stopped_cmds = 0;
5862 i = kill(- pi->pgrp, SIGCONT);
5864 if (errno == ESRCH) {
5865 delete_finished_bg_job(pi);
5866 return EXIT_SUCCESS;
5868 bb_perror_msg("kill (SIGCONT)");
5871 if (argv[0][0] == 'f') {
5873 return checkjobs_and_fg_shell(pi);
5875 return EXIT_SUCCESS;
5879 #if ENABLE_HUSH_HELP
5880 static int builtin_help(char **argv UNUSED_PARAM)
5882 const struct built_in_command *x;
5885 "Built-in commands:\n"
5886 "------------------\n");
5887 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
5888 printf("%s\t%s\n", x->cmd, x->descr);
5891 return EXIT_SUCCESS;
5896 static int builtin_jobs(char **argv UNUSED_PARAM)
5899 const char *status_string;
5901 for (job = G.job_list; job; job = job->next) {
5902 if (job->alive_cmds == job->stopped_cmds)
5903 status_string = "Stopped";
5905 status_string = "Running";
5907 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
5909 return EXIT_SUCCESS;
5913 static int builtin_pwd(char **argv UNUSED_PARAM)
5916 return EXIT_SUCCESS;
5919 static int builtin_read(char **argv)
5922 const char *name = argv[1] ? argv[1] : "REPLY";
5923 //TODO: check that argv[1] is a valid variable name
5925 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
5926 return set_local_var(string, 0, 0);
5929 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
5930 * built-in 'set' handler
5932 * set [-abCefhmnuvx] [-o option] [argument...]
5933 * set [+abCefhmnuvx] [+o option] [argument...]
5934 * set -- [argument...]
5937 * Implementations shall support the options in both their hyphen and
5938 * plus-sign forms. These options can also be specified as options to sh.
5940 * Write out all variables and their values: set
5941 * Set $1, $2, and $3 and set "$#" to 3: set c a b
5942 * Turn on the -x and -v options: set -xv
5943 * Unset all positional parameters: set --
5944 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
5945 * Set the positional parameters to the expansion of x, even if x expands
5946 * with a leading '-' or '+': set -- $x
5948 * So far, we only support "set -- [argument...]" and some of the short names.
5950 static int builtin_set(char **argv)
5953 char **pp, **g_argv;
5954 char *arg = *++argv;
5958 for (e = G.top_var; e; e = e->next)
5960 return EXIT_SUCCESS;
5964 if (!strcmp(arg, "--")) {
5969 if (arg[0] == '+' || arg[0] == '-') {
5970 for (n = 1; arg[n]; ++n)
5971 if (set_mode(arg[0], arg[n]))
5977 } while ((arg = *++argv) != NULL);
5978 /* Now argv[0] is 1st argument */
5980 /* Only reset global_argv if we didn't process anything */
5982 return EXIT_SUCCESS;
5985 /* NB: G.global_argv[0] ($0) is never freed/changed */
5986 g_argv = G.global_argv;
5987 if (G.global_args_malloced) {
5993 G.global_args_malloced = 1;
5994 pp = xzalloc(sizeof(pp[0]) * 2);
5995 pp[0] = g_argv[0]; /* retain $0 */
5998 /* This realloc's G.global_argv */
5999 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6006 return EXIT_SUCCESS;
6008 /* Nothing known, so abort */
6010 bb_error_msg("set: %s: invalid option", arg);
6011 return EXIT_FAILURE;
6014 static int builtin_shift(char **argv)
6020 if (n >= 0 && n < G.global_argc) {
6021 if (G.global_args_malloced) {
6024 free(G.global_argv[m++]);
6027 memmove(&G.global_argv[1], &G.global_argv[n+1],
6028 G.global_argc * sizeof(G.global_argv[0]));
6029 return EXIT_SUCCESS;
6031 return EXIT_FAILURE;
6034 static int builtin_source(char **argv)
6038 if (*++argv == NULL)
6039 return EXIT_FAILURE;
6041 /* XXX search through $PATH is missing */
6042 input = fopen_or_warn(*argv, "r");
6044 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6045 return EXIT_FAILURE;
6047 close_on_exec_on(fileno(input));
6049 /* Now run the file */
6051 /* XXX argv and argc are broken; need to save old G.global_argv
6052 * (pointer only is OK!) on this stack frame,
6053 * set G.global_argv=argv+1, recurse, and restore. */
6054 parse_and_run_file(input);
6056 return G.last_exitcode;
6059 static int builtin_umask(char **argv)
6062 const char *arg = argv[1];
6064 //TODO: umask may take chmod-like symbolic masks
6065 new_umask = bb_strtou(arg, NULL, 8);
6067 //Message? bash examples:
6068 //bash: umask: 'q': invalid symbolic mode operator
6069 //bash: umask: 999: octal number out of range
6070 return EXIT_FAILURE;
6073 new_umask = umask(0);
6074 printf("%.3o\n", (unsigned) new_umask);
6075 /* fall through and restore new_umask which we set to 0 */
6078 return EXIT_SUCCESS;
6081 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6082 static int builtin_unset(char **argv)
6088 return EXIT_SUCCESS;
6091 if (argv[0][0] == '-') {
6092 switch (argv[0][1]) {
6098 bb_error_msg("unset: %s: invalid option", *argv);
6099 return EXIT_FAILURE;
6101 //TODO: disallow "unset -vf ..." too
6108 if (unset_local_var(*argv)) {
6109 /* unset <nonexistent_var> doesn't fail.
6110 * Error is when one tries to unset RO var.
6111 * Message was printed by unset_local_var. */
6115 #if ENABLE_HUSH_FUNCTIONS
6117 unset_local_func(*argv);
6125 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6126 static int builtin_wait(char **argv)
6128 int ret = EXIT_SUCCESS;
6131 if (*++argv == NULL) {
6132 /* Don't care about wait results */
6133 /* Note 1: must wait until there are no more children */
6134 /* Note 2: must be interruptible */
6136 * $ sleep 3 & sleep 6 & wait
6141 * $ sleep 3 & sleep 6 & wait
6145 * ^C <-- after ~4 sec from keyboard
6148 sigaddset(&G.blocked_set, SIGCHLD);
6149 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6152 if (errno == ECHILD)
6154 /* Wait for SIGCHLD or any other signal of interest */
6155 /* sigtimedwait with infinite timeout: */
6156 sig = sigwaitinfo(&G.blocked_set, NULL);
6158 sig = check_and_run_traps(sig);
6159 if (sig && sig != SIGCHLD) { /* see note 2 */
6165 sigdelset(&G.blocked_set, SIGCHLD);
6166 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6170 /* This is probably buggy wrt interruptible-ness */
6172 pid_t pid = bb_strtou(*argv, NULL, 10);
6174 /* mimic bash message */
6175 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6176 return EXIT_FAILURE;
6178 if (waitpid(pid, &status, 0) == pid) {
6179 if (WIFSIGNALED(status))
6180 ret = 128 + WTERMSIG(status);
6181 else if (WIFEXITED(status))
6182 ret = WEXITSTATUS(status);
6186 bb_perror_msg("wait %s", *argv);
6195 #if ENABLE_HUSH_LOOPS
6196 static int builtin_break(char **argv)
6198 if (G.depth_of_loop == 0) {
6199 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6200 return EXIT_SUCCESS; /* bash compat */
6202 G.flag_break_continue++; /* BC_BREAK = 1 */
6203 G.depth_break_continue = 1;
6205 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6206 if (errno || !G.depth_break_continue || argv[2]) {
6207 bb_error_msg("%s: bad arguments", argv[0]);
6208 G.flag_break_continue = BC_BREAK;
6209 G.depth_break_continue = UINT_MAX;
6212 if (G.depth_of_loop < G.depth_break_continue)
6213 G.depth_break_continue = G.depth_of_loop;
6214 return EXIT_SUCCESS;
6217 static int builtin_continue(char **argv)
6219 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6220 return builtin_break(argv);