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 /* Enable/disable sanity checks. Ok to enable in production,
121 * only adds a bit of bloat.
122 * Keeping unconditionally on for now.
126 #define ENABLE_HUSH_FUNCTIONS 0
129 /* If you comment out one of these below, it will be #defined later
130 * to perform debug printfs to stderr: */
131 #define debug_printf(...) do {} while (0)
132 /* Finer-grained debug switches */
133 #define debug_printf_parse(...) do {} while (0)
134 #define debug_print_tree(a, b) do {} while (0)
135 #define debug_printf_exec(...) do {} while (0)
136 #define debug_printf_env(...) do {} while (0)
137 #define debug_printf_jobs(...) do {} while (0)
138 #define debug_printf_expand(...) do {} while (0)
139 #define debug_printf_glob(...) do {} while (0)
140 #define debug_printf_list(...) do {} while (0)
141 #define debug_printf_subst(...) do {} while (0)
142 #define debug_printf_clean(...) do {} while (0)
145 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
148 #ifndef debug_printf_parse
149 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
152 #ifndef debug_printf_exec
153 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
156 #ifndef debug_printf_env
157 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
160 #ifndef debug_printf_jobs
161 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
167 #ifndef debug_printf_expand
168 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
169 #define DEBUG_EXPAND 1
171 #define DEBUG_EXPAND 0
174 #ifndef debug_printf_glob
175 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
181 #ifndef debug_printf_list
182 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
185 #ifndef debug_printf_subst
186 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
189 #ifndef debug_printf_clean
190 /* broken, of course, but OK for testing */
191 static const char *indenter(int i)
193 static const char blanks[] ALIGN1 =
195 return &blanks[sizeof(blanks) - i - 1];
197 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
198 #define DEBUG_CLEAN 1
200 #define DEBUG_CLEAN 0
204 static void debug_print_strings(const char *prefix, char **vv)
206 fprintf(stderr, "%s:\n", prefix);
208 fprintf(stderr, " '%s'\n", *vv++);
211 #define debug_print_strings(prefix, vv) ((void)0)
215 * Leak hunting. Use hush_leaktool.sh for post-processing.
217 //#define FOR_HUSH_LEAKTOOL
218 #ifdef FOR_HUSH_LEAKTOOL
219 static void *xxmalloc(int lineno, size_t size)
221 void *ptr = xmalloc((size + 0xff) & ~0xff);
222 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
225 static void *xxrealloc(int lineno, void *ptr, size_t size)
227 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
228 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
231 static char *xxstrdup(int lineno, const char *str)
233 char *ptr = xstrdup(str);
234 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
237 static void xxfree(void *ptr)
239 fdprintf(2, "free %p\n", ptr);
242 #define xmalloc(s) xxmalloc(__LINE__, s)
243 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
244 #define xstrdup(s) xxstrdup(__LINE__, s)
245 #define free(p) xxfree(p)
249 #define ERR_PTR ((void*)(long)1)
251 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
253 #define SPECIAL_VAR_SYMBOL 3
255 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
257 /* This supports saving pointers malloced in vfork child,
258 * to be freed in the parent. One pointer is saved in
259 * G.argv_from_re_execing global var instead. TODO: unify.
262 typedef struct nommu_save_t {
269 /* The descrip member of this structure is only used to make
270 * debugging output pretty */
271 static const struct {
273 signed char default_fd;
277 { O_RDONLY, 0, "<" },
278 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
279 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
280 { O_RDONLY, 0, "<<" },
281 { O_CREAT|O_RDWR, 1, "<>" },
282 /* Should not be needed. Bogus default_fd helps in debugging */
283 /* { O_RDONLY, 77, "<<" }, */
286 typedef enum reserved_style {
295 #if ENABLE_HUSH_LOOPS
302 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
307 /* two pseudo-keywords support contrived "case" syntax: */
308 RES_MATCH , /* "word)" */
309 RES_CASEI , /* "this command is inside CASE" */
316 typedef struct o_string {
318 int length; /* position where data is appended */
320 /* Protect newly added chars against globbing
321 * (by prepending \ to *, ?, [, \) */
324 /* At least some part of the string was inside '' or "",
325 * possibly empty one: word"", wo''rd etc. */
327 smallint has_empty_slot;
328 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
331 MAYBE_ASSIGNMENT = 0,
332 DEFINITELY_ASSIGNMENT = 1,
334 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
336 /* Used for initialization: o_string foo = NULL_O_STRING; */
337 #define NULL_O_STRING { NULL }
339 /* I can almost use ordinary FILE*. Is open_memstream() universally
340 * available? Where is it documented? */
341 typedef struct in_str {
343 /* eof_flag=1: last char in ->p is really an EOF */
344 char eof_flag; /* meaningless if ->p == NULL */
346 #if ENABLE_HUSH_INTERACTIVE
348 smallint promptmode; /* 0: PS1, 1: PS2 */
351 int (*get) (struct in_str *);
352 int (*peek) (struct in_str *);
354 #define i_getch(input) ((input)->get(input))
355 #define i_peek(input) ((input)->peek(input))
357 struct redir_struct {
358 struct redir_struct *next;
359 char *rd_filename; /* filename */
360 int rd_fd; /* fd to redirect */
361 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
363 smallint rd_type; /* (enum redir_type) */
364 /* note: for heredocs, rd_filename contains heredoc delimiter,
365 * and subsequently heredoc itself; and rd_dup is a bitmask:
366 * 1: do we need to trim leading tabs?
367 * 2: is heredoc quoted (<<'dleim' syntax) ?
370 typedef enum redir_type {
371 REDIRECT_INVALID = 0,
373 REDIRECT_OVERWRITE = 2,
375 REDIRECT_HEREDOC = 4,
377 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
379 HEREDOC_SKIPTABS = 1,
385 pid_t pid; /* 0 if exited */
386 int assignment_cnt; /* how many argv[i] are assignments? */
387 smallint is_stopped; /* is the command currently running? */
388 smallint grp_type; /* GRP_xxx */
389 struct pipe *group; /* if non-NULL, this "command" is { list },
390 * ( list ), or a compound statement */
392 char *group_as_string;
394 char **argv; /* command name and arguments */
395 struct redir_struct *redirects; /* I/O redirections */
397 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
398 * and on execution these are substituted with their values.
399 * Substitution can make _several_ words out of one argv[n]!
400 * Example: argv[0]=='.^C*^C.' here: echo .$*.
401 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
404 #define GRP_SUBSHELL 1
405 #if ENABLE_HUSH_FUNCTIONS
406 #define GRP_FUNCTION 2
411 int num_cmds; /* total number of commands in job */
412 int alive_cmds; /* number of commands running (not exited) */
413 int stopped_cmds; /* number of commands alive, but stopped */
415 int jobid; /* job number */
416 pid_t pgrp; /* process group ID for the job */
417 char *cmdtext; /* name of job */
419 struct command *cmds; /* array of commands in pipe */
420 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
421 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
422 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
424 typedef enum pipe_style {
431 /* This holds pointers to the various results of parsing */
432 struct parse_context {
433 /* linked list of pipes */
434 struct pipe *list_head;
435 /* last pipe (being constructed right now) */
437 /* last command in pipe (being constructed right now) */
438 struct command *command;
439 /* last redirect in command->redirects list */
440 struct redir_struct *pending_redirect;
446 smallint ctx_inverted; /* "! cmd | cmd" */
448 smallint ctx_dsemicolon; /* ";;" seen */
450 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
452 /* group we are enclosed in:
453 * example: "if pipe1; pipe2; then pipe3; fi"
454 * when we see "if" or "then", we malloc and copy current context,
455 * and make ->stack point to it. then we parse pipeN.
456 * when closing "then" / fi" / whatever is found,
457 * we move list_head into ->stack->command->group,
458 * copy ->stack into current context, and delete ->stack.
459 * (parsing of { list } and ( list ) doesn't use this method)
461 struct parse_context *stack;
465 /* On program start, environ points to initial environment.
466 * putenv adds new pointers into it, unsetenv removes them.
467 * Neither of these (de)allocates the strings.
468 * setenv allocates new strings in malloc space and does putenv,
469 * and thus setenv is unusable (leaky) for shell's purposes */
470 #define setenv(...) setenv_is_leaky_dont_use()
472 struct variable *next;
473 char *varstr; /* points to "name=" portion */
474 int max_len; /* if > 0, name is part of initial env; else name is malloced */
475 smallint flg_export; /* putenv should be done on this var */
476 smallint flg_read_only;
485 /* "Globals" within this file */
486 /* Sorted roughly by size (smaller offsets == smaller code) */
488 #if ENABLE_HUSH_INTERACTIVE
489 /* 'interactive_fd' is a fd# open to ctty, if we have one
490 * _AND_ if we decided to act interactively */
494 #define G_interactive_fd (G.interactive_fd)
496 #define G_interactive_fd 0
498 #if ENABLE_FEATURE_EDITING
499 line_input_t *line_input_state;
505 pid_t saved_tty_pgrp;
507 struct pipe *job_list;
508 struct pipe *toplevel_list;
509 //// smallint ctrl_z_flag;
511 smallint flag_SIGINT;
512 #if ENABLE_HUSH_LOOPS
513 smallint flag_break_continue;
516 /* These four support $?, $#, and $1 */
517 smalluint last_exitcode;
518 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
519 smalluint global_args_malloced;
520 /* how many non-NULL argv's we have. NB: $# + 1 */
524 char *argv0_for_re_execing;
525 char **argv_from_re_execing;
527 #if ENABLE_HUSH_LOOPS
528 unsigned depth_break_continue;
529 unsigned depth_of_loop;
533 struct variable *top_var; /* = &G.shell_ver (set in main()) */
534 struct variable shell_ver;
535 /* Signal and trap handling */
536 // unsigned count_SIGCHLD;
537 // unsigned handled_SIGCHLD;
538 /* which signals have non-DFL handler (even with no traps set)? */
539 unsigned non_DFL_mask;
540 char **traps; /* char *traps[NSIG] */
541 sigset_t blocked_set;
542 sigset_t inherited_set;
544 unsigned long memleak_value;
546 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
547 #if ENABLE_FEATURE_SH_STANDALONE
548 struct nofork_save_area nofork_save;
551 sigjmp_buf toplevel_jb;
554 #define G (*ptr_to_globals)
555 /* Not #defining name to G.name - this quickly gets unwieldy
556 * (too many defines). Also, I actually prefer to see when a variable
557 * is global, thus "G." prefix is a useful hint */
558 #define INIT_G() do { \
559 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
563 /* Function prototypes for builtins */
564 static int builtin_cd(char **argv);
565 static int builtin_echo(char **argv);
566 static int builtin_eval(char **argv);
567 static int builtin_exec(char **argv);
568 static int builtin_exit(char **argv);
569 static int builtin_export(char **argv);
571 static int builtin_fg_bg(char **argv);
572 static int builtin_jobs(char **argv);
575 static int builtin_help(char **argv);
578 static int builtin_memleak(char **argv);
580 static int builtin_pwd(char **argv);
581 static int builtin_read(char **argv);
582 static int builtin_set(char **argv);
583 static int builtin_shift(char **argv);
584 static int builtin_source(char **argv);
585 static int builtin_test(char **argv);
586 static int builtin_trap(char **argv);
587 static int builtin_true(char **argv);
588 static int builtin_umask(char **argv);
589 static int builtin_unset(char **argv);
590 static int builtin_wait(char **argv);
591 #if ENABLE_HUSH_LOOPS
592 static int builtin_break(char **argv);
593 static int builtin_continue(char **argv);
596 /* Table of built-in functions. They can be forked or not, depending on
597 * context: within pipes, they fork. As simple commands, they do not.
598 * When used in non-forking context, they can change global variables
599 * in the parent shell process. If forked, of course they cannot.
600 * For example, 'unset foo | whatever' will parse and run, but foo will
601 * still be set at the end. */
602 struct built_in_command {
604 int (*function)(char **argv);
607 #define BLTIN(cmd, func, help) { cmd, func, help }
609 #define BLTIN(cmd, func, help) { cmd, func }
613 /* For now, echo and test are unconditionally enabled.
614 * Maybe make it configurable? */
615 static const struct built_in_command bltins[] = {
616 BLTIN("." , builtin_source , "Run commands in a file"),
617 BLTIN(":" , builtin_true , "No-op"),
618 BLTIN("[" , builtin_test , "Test condition"),
620 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
622 #if ENABLE_HUSH_LOOPS
623 BLTIN("break" , builtin_break , "Exit from a loop"),
625 BLTIN("cd" , builtin_cd , "Change directory"),
626 #if ENABLE_HUSH_LOOPS
627 BLTIN("continue", builtin_continue, "Start new loop iteration"),
629 BLTIN("echo" , builtin_echo , "Write to stdout"),
630 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
631 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
632 BLTIN("exit" , builtin_exit , "Exit"),
633 BLTIN("export" , builtin_export , "Set environment variable"),
635 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
638 BLTIN("help" , builtin_help , "List shell built-in commands"),
641 BLTIN("jobs" , builtin_jobs , "List active jobs"),
644 BLTIN("memleak" , builtin_memleak , "Debug tool"),
646 BLTIN("pwd" , builtin_pwd , "Print current directory"),
647 BLTIN("read" , builtin_read , "Input environment variable"),
648 // BLTIN("return" , builtin_return , "Return from a function"),
649 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
650 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
651 BLTIN("test" , builtin_test , "Test condition"),
652 BLTIN("trap" , builtin_trap , "Trap signals"),
653 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
654 BLTIN("umask" , builtin_umask , "Set file creation mask"),
655 BLTIN("unset" , builtin_unset , "Unset environment variable"),
656 BLTIN("wait" , builtin_wait , "Wait for process"),
660 static void maybe_die(const char *notice, const char *msg)
662 /* Was using fancy stuff:
663 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
664 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
665 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
666 #if ENABLE_HUSH_INTERACTIVE
667 if (G_interactive_fd)
670 fp(msg ? "%s: %s" : notice, notice, msg);
673 #define syntax(msg) maybe_die("syntax error", msg);
675 /* Debug -- trick gcc to expand __LINE__ and convert to string */
676 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
677 #define _syntax(msg, line) __syntax(msg, line)
678 #define syntax(msg) _syntax(msg, __LINE__)
682 static int glob_needed(const char *s)
687 if (*s == '*' || *s == '[' || *s == '?')
694 static int is_assignment(const char *s)
696 if (!s || !(isalpha(*s) || *s == '_'))
699 while (isalnum(*s) || *s == '_')
704 /* Replace each \x with x in place, return ptr past NUL. */
705 static char *unbackslash(char *src)
711 if ((*dst++ = *src++) == '\0')
717 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
738 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
739 v[count1 + count2] = NULL;
742 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
745 #ifdef FOR_HUSH_LEAKTOOL
746 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
748 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
749 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
752 #define add_strings_to_strings(strings, add, need_to_dup) \
753 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
756 static char **add_string_to_strings(char **strings, char *add)
761 return add_strings_to_strings(strings, v, /*dup:*/ 0);
763 #ifdef FOR_HUSH_LEAKTOOL
764 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
766 char **ptr = add_string_to_strings(strings, add);
767 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
770 #define add_string_to_strings(strings, add) \
771 xx_add_string_to_strings(__LINE__, strings, add)
774 static void putenv_all(char **strings)
779 debug_printf_env("putenv '%s'\n", *strings);
784 static char **putenv_all_and_save_old(char **strings)
794 eq = strchr(*strings, '=');
797 v = getenv(*strings);
800 /* v points to VAL in VAR=VAL, go back to VAR */
801 v -= (eq - *strings) + 1;
802 old = add_string_to_strings(old, v);
811 static void free_strings_and_unsetenv(char **strings, int unset)
821 debug_printf_env("unsetenv '%s'\n", *v);
829 static void free_strings(char **strings)
831 free_strings_and_unsetenv(strings, 0);
835 /* Basic theory of signal handling in shell
836 * ========================================
837 * This does not describe what hush does, rather, it is current understanding
838 * what it _should_ do. If it doesn't, it's a bug.
839 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
841 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
842 * is finished or backgrounded. It is the same in interactive and
843 * non-interactive shells, and is the same regardless of whether
844 * a user trap handler is installed or a shell special one is in effect.
845 * ^C or ^Z from keyboard seem to execute "at once" because it usually
846 * backgrounds (i.e. stops) or kills all members of currently running
849 * Wait builtin in interruptible by signals for which user trap is set
850 * or by SIGINT in interactive shell.
852 * Trap handlers will execute even within trap handlers. (right?)
854 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
856 * If job control is off, backgrounded commands ("cmd &")
857 * have SIGINT, SIGQUIT set to SIG_IGN.
859 * Commands run in command substitution ("`cmd`")
860 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
862 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
863 * by the shell from its parent.
865 * Siganls which differ from SIG_DFL action
866 * (note: child (i.e., [v]forked) shell is not an interactive shell):
869 * SIGTERM (interactive): ignore
870 * SIGHUP (interactive):
871 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
872 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
873 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
874 * that all pipe members are stopped) (right?)
875 * SIGINT (interactive): wait for last pipe, ignore the rest
876 * of the command line, show prompt. NB: ^C does not send SIGINT
877 * to interactive shell while shell is waiting for a pipe,
878 * since shell is bg'ed (is not in foreground process group).
879 * (check/expand this)
880 * Example 1: this waits 5 sec, but does not execute ls:
881 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
882 * Example 2: this does not wait and does not execute ls:
883 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
884 * Example 3: this does not wait 5 sec, but executes ls:
885 * "sleep 5; ls -l" + press ^C
887 * (What happens to signals which are IGN on shell start?)
888 * (What happens with signal mask on shell start?)
890 * Implementation in hush
891 * ======================
892 * We use in-kernel pending signal mask to determine which signals were sent.
893 * We block all signals which we don't want to take action immediately,
894 * i.e. we block all signals which need to have special handling as described
895 * above, and all signals which have traps set.
896 * After each pipe execution, we extract any pending signals via sigtimedwait()
899 * unsigned non_DFL_mask: a mask of such "special" signals
900 * sigset_t blocked_set: current blocked signal set
903 * clear bit in blocked_set unless it is also in non_DFL_mask
904 * "trap 'cmd' SIGxxx":
905 * set bit in blocked_set (even if 'cmd' is '')
906 * after [v]fork, if we plan to be a shell:
907 * nothing for {} child shell (say, "true | { true; true; } | true")
908 * unset all traps if () shell. [TODO]
909 * after [v]fork, if we plan to exec:
910 * POSIX says pending signal mask is cleared in child - no need to clear it.
911 * Restore blocked signal set to one inherited by shell just prior to exec.
913 * Note: as a result, we do not use signal handlers much. The only uses
914 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
915 * and to restore tty pgrp on signal-induced exit.
918 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
920 // G.count_SIGCHLD++;
923 static int check_and_run_traps(int sig)
925 static const struct timespec zero_timespec = { 0, 0 };
926 smalluint save_rcode;
932 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
937 if (G.traps && G.traps[sig]) {
938 if (G.traps[sig][0]) {
939 /* We have user-defined handler */
940 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
941 save_rcode = G.last_exitcode;
944 G.last_exitcode = save_rcode;
945 } /* else: "" trap, ignoring signal */
948 /* not a trap: special action */
951 // G.count_SIGCHLD++;
960 default: /* ignored: */
961 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
970 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
971 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
972 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
973 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
975 /* Restores tty foreground process group, and exits.
976 * May be called as signal handler for fatal signal
977 * (will faithfully resend signal to itself, producing correct exit state)
978 * or called directly with -EXITCODE.
979 * We also call it if xfunc is exiting. */
980 static void sigexit(int sig) NORETURN;
981 static void sigexit(int sig)
983 /* Disable all signals: job control, SIGPIPE, etc. */
984 sigprocmask_allsigs(SIG_BLOCK);
986 /* Careful: we can end up here after [v]fork. Do not restore
987 * tty pgrp then, only top-level shell process does that */
988 if (G_interactive_fd && getpid() == G.root_pid)
989 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
991 /* Not a signal, just exit */
995 kill_myself_with_sig(sig); /* does not return */
999 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1000 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1004 /* Restores tty foreground process group, and exits. */
1005 static void hush_exit(int exitcode) NORETURN;
1006 static void hush_exit(int exitcode)
1008 if (G.traps && G.traps[0] && G.traps[0][0]) {
1009 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1010 //TODO: do we need to prevent recursion?
1016 fflush(NULL); /* flush all streams */
1017 sigexit(- (exitcode & 0xff));
1024 static const char *set_cwd(void)
1026 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1027 * we must not try to free(bb_msg_unknown) */
1028 if (G.cwd == bb_msg_unknown)
1030 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1032 G.cwd = bb_msg_unknown;
1037 /* Get/check local shell variables */
1038 static struct variable *get_local_var(const char *name)
1040 struct variable *cur;
1046 for (cur = G.top_var; cur; cur = cur->next) {
1047 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1053 static const char *get_local_var_value(const char *src)
1055 struct variable *var = get_local_var(src);
1057 return strchr(var->varstr, '=') + 1;
1061 /* str holds "NAME=VAL" and is expected to be malloced.
1062 * We take ownership of it.
1066 * -1: if NAME is set, leave export status alone
1067 * if NAME is not set, do not export
1068 * flg_read_only is set only when we handle -R var=val
1071 #define set_local_var(str, flg_export, flg_read_only) \
1072 set_local_var(str, flg_export)
1074 static int set_local_var(char *str, int flg_export, int flg_read_only)
1076 struct variable *cur;
1080 value = strchr(str, '=');
1081 if (!value) { /* not expected to ever happen? */
1086 name_len = value - str + 1; /* including '=' */
1087 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1089 if (strncmp(cur->varstr, str, name_len) != 0) {
1091 /* Bail out. Note that now cur points
1092 * to last var in linked list */
1098 /* We found an existing var with this name */
1100 if (cur->flg_read_only) {
1104 bb_error_msg("%s: readonly variable", str);
1108 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1109 unsetenv(str); /* just in case */
1111 if (strcmp(cur->varstr, str) == 0) {
1116 if (cur->max_len >= strlen(str)) {
1117 /* This one is from startup env, reuse space */
1118 strcpy(cur->varstr, str);
1121 /* max_len == 0 signifies "malloced" var, which we can
1122 * (and has to) free */
1126 goto set_str_and_exp;
1129 /* Not found - create next variable struct */
1130 cur->next = xzalloc(sizeof(*cur));
1136 cur->flg_read_only = flg_read_only;
1139 if (flg_export == 1)
1140 cur->flg_export = 1;
1141 if (cur->flg_export) {
1142 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1143 return putenv(cur->varstr);
1148 static int unset_local_var(const char *name)
1150 struct variable *cur;
1151 struct variable *prev = prev; /* for gcc */
1155 return EXIT_SUCCESS;
1156 name_len = strlen(name);
1159 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1160 if (cur->flg_read_only) {
1161 bb_error_msg("%s: readonly variable", name);
1162 return EXIT_FAILURE;
1164 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1165 * is ro, and we cannot reach this code on the 1st pass */
1166 prev->next = cur->next;
1167 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1168 bb_unsetenv(cur->varstr);
1172 return EXIT_SUCCESS;
1177 return EXIT_SUCCESS;
1180 #if ENABLE_SH_MATH_SUPPORT
1181 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1182 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1183 static char *endofname(const char *name)
1191 if (!is_in_name(*p))
1197 static void arith_set_local_var(const char *name, const char *val, int flags)
1199 /* arith code doesnt malloc space, so do it for it */
1200 char *var = xasprintf("%s=%s", name, val);
1201 set_local_var(var, flags, 0);
1209 static int static_get(struct in_str *i)
1218 static int static_peek(struct in_str *i)
1223 #if ENABLE_HUSH_INTERACTIVE
1225 static void cmdedit_set_initial_prompt(void)
1227 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1228 G.PS1 = getenv("PS1");
1235 static const char* setup_prompt_string(int promptmode)
1237 const char *prompt_str;
1238 debug_printf("setup_prompt_string %d ", promptmode);
1239 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1240 /* Set up the prompt */
1241 if (promptmode == 0) { /* PS1 */
1243 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1248 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1249 debug_printf("result '%s'\n", prompt_str);
1253 static void get_user_input(struct in_str *i)
1256 const char *prompt_str;
1258 prompt_str = setup_prompt_string(i->promptmode);
1259 #if ENABLE_FEATURE_EDITING
1260 /* Enable command line editing only while a command line
1261 * is actually being read */
1264 /* buglet: SIGINT will not make new prompt to appear _at once_,
1265 * only after <Enter>. (^C will work) */
1266 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1267 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1268 check_and_run_traps(0);
1269 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1270 i->eof_flag = (r < 0);
1271 if (i->eof_flag) { /* EOF/error detected */
1272 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1273 G.user_input_buf[1] = '\0';
1278 fputs(prompt_str, stdout);
1280 G.user_input_buf[0] = r = fgetc(i->file);
1281 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1282 //do we need check_and_run_traps(0)? (maybe only if stdin)
1283 } while (G.flag_SIGINT);
1284 i->eof_flag = (r == EOF);
1286 i->p = G.user_input_buf;
1289 #endif /* INTERACTIVE */
1291 /* This is the magic location that prints prompts
1292 * and gets data back from the user */
1293 static int file_get(struct in_str *i)
1297 /* If there is data waiting, eat it up */
1298 if (i->p && *i->p) {
1299 #if ENABLE_HUSH_INTERACTIVE
1303 if (i->eof_flag && !*i->p)
1305 /* note: ch is never NUL */
1307 /* need to double check i->file because we might be doing something
1308 * more complicated by now, like sourcing or substituting. */
1309 #if ENABLE_HUSH_INTERACTIVE
1310 if (G_interactive_fd && i->promptme && i->file == stdin) {
1313 } while (!*i->p); /* need non-empty line */
1314 i->promptmode = 1; /* PS2 */
1319 do ch = fgetc(i->file); while (ch == '\0');
1321 debug_printf("file_get: got '%c' %d\n", ch, ch);
1322 #if ENABLE_HUSH_INTERACTIVE
1329 /* All callers guarantee this routine will never
1330 * be used right after a newline, so prompting is not needed.
1332 static int file_peek(struct in_str *i)
1335 if (i->p && *i->p) {
1336 if (i->eof_flag && !i->p[1])
1339 /* note: ch is never NUL */
1341 do ch = fgetc(i->file); while (ch == '\0');
1342 i->eof_flag = (ch == EOF);
1343 i->peek_buf[0] = ch;
1344 i->peek_buf[1] = '\0';
1346 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1350 static void setup_file_in_str(struct in_str *i, FILE *f)
1352 i->peek = file_peek;
1354 #if ENABLE_HUSH_INTERACTIVE
1356 i->promptmode = 0; /* PS1 */
1362 static void setup_string_in_str(struct in_str *i, const char *s)
1364 i->peek = static_peek;
1365 i->get = static_get;
1366 #if ENABLE_HUSH_INTERACTIVE
1368 i->promptmode = 0; /* PS1 */
1378 #define B_CHUNK (32 * sizeof(char*))
1380 static void o_reset(o_string *o)
1388 static void o_free(o_string *o)
1391 memset(o, 0, sizeof(*o));
1394 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1399 static void o_grow_by(o_string *o, int len)
1401 if (o->length + len > o->maxlen) {
1402 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1403 o->data = xrealloc(o->data, 1 + o->maxlen);
1407 static void o_addchr(o_string *o, int ch)
1409 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1411 o->data[o->length] = ch;
1413 o->data[o->length] = '\0';
1416 static void o_addblock(o_string *o, const char *str, int len)
1419 memcpy(&o->data[o->length], str, len);
1421 o->data[o->length] = '\0';
1425 static void o_addstr(o_string *o, const char *str)
1427 o_addblock(o, str, strlen(str));
1429 static void nommu_addchr(o_string *o, int ch)
1435 #define nommu_addchr(o, str) ((void)0)
1438 static void o_addstr_with_NUL(o_string *o, const char *str)
1440 o_addblock(o, str, strlen(str) + 1);
1443 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1448 && (*str != '*' && *str != '?' && *str != '[')
1456 /* My analysis of quoting semantics tells me that state information
1457 * is associated with a destination, not a source.
1459 static void o_addqchr(o_string *o, int ch)
1462 char *found = strchr("*?[\\", ch);
1467 o->data[o->length] = '\\';
1470 o->data[o->length] = ch;
1472 o->data[o->length] = '\0';
1475 static void o_addQchr(o_string *o, int ch)
1478 if (o->o_escape && strchr("*?[\\", ch)) {
1480 o->data[o->length] = '\\';
1484 o->data[o->length] = ch;
1486 o->data[o->length] = '\0';
1489 static void o_addQstr(o_string *o, const char *str, int len)
1492 o_addblock(o, str, len);
1498 int ordinary_cnt = strcspn(str, "*?[\\");
1499 if (ordinary_cnt > len) /* paranoia */
1501 o_addblock(o, str, ordinary_cnt);
1502 if (ordinary_cnt == len)
1504 str += ordinary_cnt;
1505 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1509 if (ch) { /* it is necessarily one of "*?[\\" */
1511 o->data[o->length] = '\\';
1515 o->data[o->length] = ch;
1517 o->data[o->length] = '\0';
1521 /* A special kind of o_string for $VAR and `cmd` expansion.
1522 * It contains char* list[] at the beginning, which is grown in 16 element
1523 * increments. Actual string data starts at the next multiple of 16 * (char*).
1524 * list[i] contains an INDEX (int!) into this string data.
1525 * It means that if list[] needs to grow, data needs to be moved higher up
1526 * but list[i]'s need not be modified.
1527 * NB: remembering how many list[i]'s you have there is crucial.
1528 * o_finalize_list() operation post-processes this structure - calculates
1529 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1531 #if DEBUG_EXPAND || DEBUG_GLOB
1532 static void debug_print_list(const char *prefix, o_string *o, int n)
1534 char **list = (char**)o->data;
1535 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1537 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1538 prefix, list, n, string_start, o->length, o->maxlen);
1540 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1541 o->data + (int)list[i] + string_start,
1542 o->data + (int)list[i] + string_start);
1546 const char *p = o->data + (int)list[n - 1] + string_start;
1547 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1551 #define debug_print_list(prefix, o, n) ((void)0)
1554 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1555 * in list[n] so that it points past last stored byte so far.
1556 * It returns n+1. */
1557 static int o_save_ptr_helper(o_string *o, int n)
1559 char **list = (char**)o->data;
1563 if (!o->has_empty_slot) {
1564 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1565 string_len = o->length - string_start;
1566 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1567 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1568 /* list[n] points to string_start, make space for 16 more pointers */
1569 o->maxlen += 0x10 * sizeof(list[0]);
1570 o->data = xrealloc(o->data, o->maxlen + 1);
1571 list = (char**)o->data;
1572 memmove(list + n + 0x10, list + n, string_len);
1573 o->length += 0x10 * sizeof(list[0]);
1575 debug_printf_list("list[%d]=%d string_start=%d\n",
1576 n, string_len, string_start);
1579 /* We have empty slot at list[n], reuse without growth */
1580 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1581 string_len = o->length - string_start;
1582 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1583 n, string_len, string_start);
1584 o->has_empty_slot = 0;
1586 list[n] = (char*)(ptrdiff_t)string_len;
1590 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1591 static int o_get_last_ptr(o_string *o, int n)
1593 char **list = (char**)o->data;
1594 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1596 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1599 /* o_glob performs globbing on last list[], saving each result
1600 * as a new list[]. */
1601 static int o_glob(o_string *o, int n)
1607 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1609 return o_save_ptr_helper(o, n);
1610 pattern = o->data + o_get_last_ptr(o, n);
1611 debug_printf_glob("glob pattern '%s'\n", pattern);
1612 if (!glob_needed(pattern)) {
1614 o->length = unbackslash(pattern) - o->data;
1615 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1616 return o_save_ptr_helper(o, n);
1619 memset(&globdata, 0, sizeof(globdata));
1620 gr = glob(pattern, 0, NULL, &globdata);
1621 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1622 if (gr == GLOB_NOSPACE)
1623 bb_error_msg_and_die("out of memory during glob");
1624 if (gr == GLOB_NOMATCH) {
1625 globfree(&globdata);
1628 if (gr != 0) { /* GLOB_ABORTED ? */
1629 //TODO: testcase for bad glob pattern behavior
1630 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1632 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1633 char **argv = globdata.gl_pathv;
1634 o->length = pattern - o->data; /* "forget" pattern */
1636 o_addstr_with_NUL(o, *argv);
1637 n = o_save_ptr_helper(o, n);
1643 globfree(&globdata);
1645 debug_print_list("o_glob returning", o, n);
1649 /* If o->o_glob == 1, glob the string so far remembered.
1650 * Otherwise, just finish current list[] and start new */
1651 static int o_save_ptr(o_string *o, int n)
1653 if (o->o_glob) { /* if globbing is requested */
1654 /* If o->has_empty_slot, list[n] was already globbed
1655 * (if it was requested back then when it was filled)
1656 * so don't do that again! */
1657 if (!o->has_empty_slot)
1658 return o_glob(o, n); /* o_save_ptr_helper is inside */
1660 return o_save_ptr_helper(o, n);
1663 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1664 static char **o_finalize_list(o_string *o, int n)
1669 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1671 debug_print_list("finalized", o, n);
1672 debug_printf_expand("finalized n:%d\n", n);
1673 list = (char**)o->data;
1674 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1678 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1684 /* Expansion can recurse */
1685 #if ENABLE_HUSH_TICK
1686 static int process_command_subs(o_string *dest, const char *s);
1688 static char *expand_string_to_string(const char *str);
1690 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1691 parse_stream_dquoted(dest, input, dquote_end)
1693 static int parse_stream_dquoted(o_string *as_string,
1695 struct in_str *input,
1698 /* expand_strvec_to_strvec() takes a list of strings, expands
1699 * all variable references within and returns a pointer to
1700 * a list of expanded strings, possibly with larger number
1701 * of strings. (Think VAR="a b"; echo $VAR).
1702 * This new list is allocated as a single malloc block.
1703 * NULL-terminated list of char* pointers is at the beginning of it,
1704 * followed by strings themself.
1705 * Caller can deallocate entire list by single free(list). */
1707 /* Store given string, finalizing the word and starting new one whenever
1708 * we encounter IFS char(s). This is used for expanding variable values.
1709 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1710 static int expand_on_ifs(o_string *output, int n, const char *str)
1713 int word_len = strcspn(str, G.ifs);
1715 if (output->o_escape || !output->o_glob)
1716 o_addQstr(output, str, word_len);
1717 else /* protect backslashes against globbing up :) */
1718 o_addblock_duplicate_backslash(output, str, word_len);
1721 if (!*str) /* EOL - do not finalize word */
1723 o_addchr(output, '\0');
1724 debug_print_list("expand_on_ifs", output, n);
1725 n = o_save_ptr(output, n);
1726 str += strspn(str, G.ifs); /* skip ifs chars */
1728 debug_print_list("expand_on_ifs[1]", output, n);
1732 /* Helper to expand $((...)) and heredoc body. These act as if
1733 * they are in double quotes, with the exception that they are not :).
1734 * Just the rules are similar: "expand only $var and `cmd`"
1736 * Returns malloced string.
1737 * As an optimization, we return NULL if expansion is not needed.
1739 static char *expand_pseudo_dquoted(const char *str)
1742 struct in_str input;
1743 o_string dest = NULL_O_STRING;
1745 if (strchr(str, '$') == NULL
1746 #if ENABLE_HUSH_TICK
1747 && strchr(str, '`') == NULL
1753 /* We need to expand. Example:
1754 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1756 setup_string_in_str(&input, str);
1757 parse_stream_dquoted(NULL, &dest, &input, EOF);
1758 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1759 exp_str = expand_string_to_string(dest.data);
1760 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1761 o_free_unsafe(&dest);
1765 /* Expand all variable references in given string, adding words to list[]
1766 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1767 * to be filled). This routine is extremely tricky: has to deal with
1768 * variables/parameters with whitespace, $* and $@, and constructs like
1769 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1770 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1772 /* or_mask is either 0 (normal case) or 0x80
1773 * (expansion of right-hand side of assignment == 1-element expand.
1774 * It will also do no globbing, and thus we must not backslash-quote!) */
1776 char first_ch, ored_ch;
1784 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1785 debug_print_list("expand_vars_to_list", output, n);
1786 n = o_save_ptr(output, n);
1787 debug_print_list("expand_vars_to_list[0]", output, n);
1789 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1790 #if ENABLE_HUSH_TICK
1791 o_string subst_result = NULL_O_STRING;
1793 #if ENABLE_SH_MATH_SUPPORT
1794 char arith_buf[sizeof(arith_t)*3 + 2];
1796 o_addblock(output, arg, p - arg);
1797 debug_print_list("expand_vars_to_list[1]", output, n);
1799 p = strchr(p, SPECIAL_VAR_SYMBOL);
1801 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1802 /* "$@" is special. Even if quoted, it can still
1803 * expand to nothing (not even an empty string) */
1804 if ((first_ch & 0x7f) != '@')
1805 ored_ch |= first_ch;
1808 switch (first_ch & 0x7f) {
1809 /* Highest bit in first_ch indicates that var is double-quoted */
1811 val = utoa(G.root_pid);
1813 case '!': /* bg pid */
1814 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1816 case '?': /* exitcode */
1817 val = utoa(G.last_exitcode);
1819 case '#': /* argc */
1820 if (arg[1] != SPECIAL_VAR_SYMBOL)
1821 /* actually, it's a ${#var} */
1823 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1828 if (!G.global_argv[i])
1830 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1831 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1832 smallint sv = output->o_escape;
1833 /* unquoted var's contents should be globbed, so don't escape */
1834 output->o_escape = 0;
1835 while (G.global_argv[i]) {
1836 n = expand_on_ifs(output, n, G.global_argv[i]);
1837 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1838 if (G.global_argv[i++][0] && G.global_argv[i]) {
1839 /* this argv[] is not empty and not last:
1840 * put terminating NUL, start new word */
1841 o_addchr(output, '\0');
1842 debug_print_list("expand_vars_to_list[2]", output, n);
1843 n = o_save_ptr(output, n);
1844 debug_print_list("expand_vars_to_list[3]", output, n);
1847 output->o_escape = sv;
1849 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1850 * and in this case should treat it like '$*' - see 'else...' below */
1851 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1853 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1854 if (++i >= G.global_argc)
1856 o_addchr(output, '\0');
1857 debug_print_list("expand_vars_to_list[4]", output, n);
1858 n = o_save_ptr(output, n);
1860 } else { /* quoted $*: add as one word */
1862 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1863 if (!G.global_argv[++i])
1866 o_addchr(output, G.ifs[0]);
1870 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1871 /* "Empty variable", used to make "" etc to not disappear */
1875 #if ENABLE_HUSH_TICK
1876 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1879 //TODO: can we just stuff it into "output" directly?
1880 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1881 process_command_subs(&subst_result, arg);
1882 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1883 val = subst_result.data;
1886 #if ENABLE_SH_MATH_SUPPORT
1887 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1888 arith_eval_hooks_t hooks;
1893 arg++; /* skip '+' */
1894 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1895 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1897 exp_str = expand_pseudo_dquoted(arg);
1898 hooks.lookupvar = get_local_var_value;
1899 hooks.setvar = arith_set_local_var;
1900 hooks.endofname = endofname;
1901 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1906 case -3: maybe_die("arith", "exponent less than 0"); break;
1907 case -2: maybe_die("arith", "divide by zero"); break;
1908 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1909 default: maybe_die("arith", "syntax error"); break;
1912 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1913 sprintf(arith_buf, arith_t_fmt, res);
1918 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1920 bool exp_len = false;
1921 bool exp_null = false;
1923 char exp_save = exp_save; /* for compiler */
1924 char exp_op = exp_op; /* for compiler */
1925 char *exp_word = exp_word; /* for compiler */
1929 arg[0] = first_ch & 0x7f;
1931 /* prepare for expansions */
1932 if (var[0] == '#') {
1933 /* handle length expansion ${#var} */
1937 /* maybe handle parameter expansion */
1938 exp_off = strcspn(var, ":-=+?%#");
1942 exp_save = var[exp_off];
1943 exp_null = exp_save == ':';
1944 exp_word = var + exp_off;
1945 if (exp_null) ++exp_word;
1946 exp_op = *exp_word++;
1947 var[exp_off] = '\0';
1951 /* lookup the variable in question */
1952 if (isdigit(var[0])) {
1953 /* handle_dollar() should have vetted var for us */
1955 if (i < G.global_argc)
1956 val = G.global_argv[i];
1957 /* else val remains NULL: $N with too big N */
1959 val = get_local_var_value(var);
1961 /* handle any expansions */
1963 debug_printf_expand("expand: length of '%s' = ", val);
1964 val = utoa(val ? strlen(val) : 0);
1965 debug_printf_expand("%s\n", val);
1966 } else if (exp_off) {
1967 if (exp_op == '%' || exp_op == '#') {
1968 /* we need to do a pattern match */
1971 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1972 if (exp_op == *exp_word) /* ## or %% */
1974 val = dyn_val = xstrdup(val);
1975 loc = scan(dyn_val, exp_word, zero);
1981 /* we need to do an expansion */
1982 int exp_test = (!val || (exp_null && !val[0]));
1984 exp_test = !exp_test;
1985 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1986 exp_null ? "true" : "false", exp_test);
1989 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1993 if (exp_op == '=') {
1994 if (isdigit(var[0]) || var[0] == '#') {
1995 maybe_die(var, "special vars cannot assign in this way");
1998 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1999 sprintf(new_var, "%s=%s", var, val);
2000 set_local_var(new_var, -1, 0);
2006 var[exp_off] = exp_save;
2010 #if ENABLE_HUSH_TICK
2013 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2014 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2016 /* unquoted var's contents should be globbed, so don't escape */
2017 smallint sv = output->o_escape;
2018 output->o_escape = 0;
2019 n = expand_on_ifs(output, n, val);
2021 output->o_escape = sv;
2023 } else { /* quoted $VAR, val will be appended below */
2024 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2027 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2029 o_addQstr(output, val, strlen(val));
2033 /* Do the check to avoid writing to a const string */
2034 if (*p != SPECIAL_VAR_SYMBOL)
2035 *p = SPECIAL_VAR_SYMBOL;
2037 #if ENABLE_HUSH_TICK
2038 o_free(&subst_result);
2041 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2044 debug_print_list("expand_vars_to_list[a]", output, n);
2045 /* this part is literal, and it was already pre-quoted
2046 * if needed (much earlier), do not use o_addQstr here! */
2047 o_addstr_with_NUL(output, arg);
2048 debug_print_list("expand_vars_to_list[b]", output, n);
2049 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2050 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2053 /* allow to reuse list[n] later without re-growth */
2054 output->has_empty_slot = 1;
2056 o_addchr(output, '\0');
2061 static char **expand_variables(char **argv, int or_mask)
2066 o_string output = NULL_O_STRING;
2068 if (or_mask & 0x100) {
2069 output.o_escape = 1; /* protect against globbing for "$var" */
2070 /* (unquoted $var will temporarily switch it off) */
2077 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2080 debug_print_list("expand_variables", &output, n);
2082 /* output.data (malloced in one block) gets returned in "list" */
2083 list = o_finalize_list(&output, n);
2084 debug_print_strings("expand_variables[1]", list);
2088 static char **expand_strvec_to_strvec(char **argv)
2090 return expand_variables(argv, 0x100);
2093 /* Used for expansion of right hand of assignments */
2094 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2096 static char *expand_string_to_string(const char *str)
2098 char *argv[2], **list;
2100 argv[0] = (char*)str;
2102 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2104 if (!list[0] || list[1])
2105 bb_error_msg_and_die("BUG in varexp2");
2106 /* actually, just move string 2*sizeof(char*) bytes back */
2107 overlapping_strcpy((char*)list, list[0]);
2108 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2112 /* Used for "eval" builtin */
2113 static char* expand_strvec_to_string(char **argv)
2117 list = expand_variables(argv, 0x80);
2118 /* Convert all NULs to spaces */
2123 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2124 bb_error_msg_and_die("BUG in varexp3");
2125 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2129 overlapping_strcpy((char*)list, list[0]);
2130 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2134 static char **expand_assignments(char **argv, int count)
2138 /* Expand assignments into one string each */
2139 for (i = 0; i < count; i++) {
2140 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2147 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2148 #define clean_up_after_re_execute() ((void)0)
2149 static void reset_traps_to_defaults(void)
2157 for (sig = 0; sig < NSIG; sig++) {
2161 G.traps[sig] = NULL;
2162 /* There is no signal for 0 (EXIT) */
2165 /* there was a trap handler, we are removing it
2166 * (if sig has non-DFL handling,
2167 * we don't need to do anything) */
2168 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2170 sigdelset(&G.blocked_set, sig);
2174 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2179 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2180 static void re_execute_shell(const char *s, int is_heredoc)
2182 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2183 struct variable *cur;
2184 char **argv, **pp, **pp2;
2187 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2188 , (unsigned) G.root_pid
2189 , (unsigned) G.last_bg_pid
2190 , (unsigned) G.last_exitcode
2191 USE_HUSH_LOOPS(, G.depth_of_loop)
2193 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2194 * 3:-c 4:<cmd> <argN...> 5:NULL
2196 cnt = 5 + G.global_argc;
2197 for (cur = G.top_var; cur; cur = cur->next) {
2198 if (!cur->flg_export || cur->flg_read_only)
2201 G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
2202 *pp++ = (char *) G.argv0_for_re_execing;
2204 for (cur = G.top_var; cur; cur = cur->next) {
2205 if (cur->varstr == hush_version_str)
2207 if (cur->flg_read_only) {
2208 *pp++ = (char *) "-R";
2209 *pp++ = cur->varstr;
2210 } else if (!cur->flg_export) {
2211 *pp++ = (char *) "-V";
2212 *pp++ = cur->varstr;
2215 //TODO: pass functions
2216 /* We can pass activated traps here. Say, -Tnn:trap_string
2218 * However, POSIX says that subshells reset signals with traps
2220 * I tested bash-3.2 and it not only does that with true subshells
2221 * of the form ( list ), but with any forked children shells.
2222 * I set trap "echo W" WINCH; and then tried:
2224 * { echo 1; sleep 20; echo 2; } &
2225 * while true; do echo 1; sleep 20; echo 2; break; done &
2226 * true | { echo 1; sleep 20; echo 2; } | cat
2228 * In all these cases sending SIGWINCH to the child shell
2229 * did not run the trap. If I add trap "echo V" WINCH;
2230 * _inside_ group (just before echo 1), it works.
2232 * I conclude it means we don't need to pass active traps here.
2233 * exec syscall below resets them to SIG_DFL for us.
2235 *pp++ = (char *) (is_heredoc ? "-<" : "-c");
2237 pp2 = G.global_argv;
2240 /* *pp = NULL; - is already there */
2242 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2243 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2244 execve(bb_busybox_exec_path,
2245 G.argv_from_re_execing,
2246 (is_heredoc ? pp /* points to NULL ptr */ : environ)
2248 /* Fallback. Useful for init=/bin/hush usage etc */
2249 if (G.argv0_for_re_execing[0] == '/')
2250 execv(G.argv0_for_re_execing, G.argv_from_re_execing);
2251 xfunc_error_retval = 127;
2252 bb_error_msg_and_die("can't re-execute the shell");
2255 static void clean_up_after_re_execute(void)
2257 char **pp = G.argv_from_re_execing;
2259 /* Must match re_execute_shell's allocations (if any) */
2261 G.argv_from_re_execing = NULL;
2264 #endif /* !BB_MMU */
2267 static void setup_heredoc(struct redir_struct *redir)
2269 struct fd_pair pair;
2272 /* the _body_ of heredoc (misleading field name) */
2273 const char *heredoc = redir->rd_filename;
2277 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2278 expanded = expand_pseudo_dquoted(heredoc);
2282 len = strlen(heredoc);
2285 xmove_fd(pair.rd, redir->rd_fd);
2287 /* Try writing without forking. Newer kernels have
2288 * dynamically growing pipes. Must use non-blocking write! */
2291 written = write(pair.wr, heredoc, len);
2301 ndelay_off(pair.wr);
2303 /* Okay, pipe buffer was not big enough */
2304 /* Note: we must not create a stray child (bastard? :)
2305 * for the unsuspecting parent process. Child creates a grandchild
2306 * and exits before parent execs the process which consumes heredoc
2307 * (that exec happens after we return from this function) */
2310 bb_perror_msg_and_die("vfork");
2313 pid = BB_MMU ? fork() : vfork();
2315 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2319 close(redir->rd_fd); /* read side of the pipe */
2321 full_write(pair.wr, heredoc, len); /* may loop or block */
2324 /* Delegate blocking writes to another process */
2325 disable_restore_tty_pgrp_on_exit();
2326 xmove_fd(pair.wr, STDOUT_FILENO);
2327 re_execute_shell(heredoc, 1);
2331 enable_restore_tty_pgrp_on_exit();
2332 clean_up_after_re_execute();
2335 wait(NULL); /* wait till child has died */
2338 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2339 * and stderr if they are redirected. */
2340 static int setup_redirects(struct command *prog, int squirrel[])
2342 //TODO: no callers ever check return value - ?!
2344 struct redir_struct *redir;
2346 for (redir = prog->redirects; redir; redir = redir->next) {
2347 if (redir->rd_type == REDIRECT_HEREDOC2) {
2348 if (squirrel && redir->rd_fd < 3) {
2349 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2351 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2353 debug_printf_parse("set heredoc '%s'\n",
2354 redir->rd_filename);
2355 setup_heredoc(redir);
2359 if (redir->rd_dup == -1) {
2361 if (redir->rd_filename == NULL) {
2362 /* Something went wrong in the parse.
2363 * Pretend it didn't happen */
2366 mode = redir_table[redir->rd_type].mode;
2367 //TODO: check redir for names like '\\'
2368 p = expand_string_to_string(redir->rd_filename);
2369 openfd = open_or_warn(p, mode);
2372 /* this could get lost if stderr has been redirected, but
2373 * bash and ash both lose it as well (though zsh doesn't!) */
2374 //what the above comment tries to say?
2378 openfd = redir->rd_dup;
2381 if (openfd != redir->rd_fd) {
2382 if (squirrel && redir->rd_fd < 3) {
2383 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2385 if (openfd == REDIRFD_CLOSE) {
2386 /* "n>-" means "close me" */
2387 close(redir->rd_fd);
2389 xdup2(openfd, redir->rd_fd);
2390 if (redir->rd_dup == -1)
2398 static void restore_redirects(int squirrel[])
2401 for (i = 0; i < 3; i++) {
2404 /* We simply die on error */
2412 #define free_pipe_list(head, indent) free_pipe_list(head)
2413 #define free_pipe(pi, indent) free_pipe(pi)
2415 static void free_pipe_list(struct pipe *head, int indent);
2417 /* Return code is the exit status of the pipe */
2418 static void free_pipe(struct pipe *pi, int indent)
2421 struct command *command;
2422 struct redir_struct *r, *rnext;
2425 if (pi->stopped_cmds > 0) /* why? */
2427 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2428 for (i = 0; i < pi->num_cmds; i++) {
2429 command = &pi->cmds[i];
2430 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2431 if (command->argv) {
2432 for (a = 0, p = command->argv; *p; a++, p++) {
2433 debug_printf_clean("%s argv[%d] = %s\n",
2434 indenter(indent), a, *p);
2436 free_strings(command->argv);
2437 command->argv = NULL;
2439 /* not "else if": on syntax error, we may have both! */
2440 if (command->group) {
2441 debug_printf_clean("%s begin group (grp_type:%d)\n",
2442 indenter(indent), command->grp_type);
2443 free_pipe_list(command->group, indent+3);
2444 debug_printf_clean("%s end group\n", indenter(indent));
2445 command->group = NULL;
2448 free(command->group_as_string);
2449 command->group_as_string = NULL;
2451 for (r = command->redirects; r; r = rnext) {
2452 debug_printf_clean("%s redirect %d%s", indenter(indent),
2453 r->fd, redir_table[r->rd_type].descrip);
2454 /* guard against the case >$FOO, where foo is unset or blank */
2455 if (r->rd_filename) {
2456 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2457 free(r->rd_filename);
2458 r->rd_filename = NULL;
2460 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2464 command->redirects = NULL;
2466 free(pi->cmds); /* children are an array, they get freed all at once */
2474 static void free_pipe_list(struct pipe *head, int indent)
2476 struct pipe *pi, *next;
2478 for (pi = head; pi; pi = next) {
2480 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2482 free_pipe(pi, indent);
2483 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2485 /*pi->next = NULL;*/
2492 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2493 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2494 #define pseudo_exec(nommu_save, command, argv_expanded) \
2495 pseudo_exec(command, argv_expanded)
2498 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2500 * XXX no exit() here. If you don't exec, use _exit instead.
2501 * The at_exit handlers apparently confuse the calling process,
2502 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2503 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2504 char **argv, int assignment_cnt,
2505 char **argv_expanded) NORETURN;
2506 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2507 char **argv, int assignment_cnt,
2508 char **argv_expanded)
2512 /* Case when we are here: ... | var=val | ... */
2513 if (!argv[assignment_cnt])
2514 _exit(EXIT_SUCCESS);
2516 new_env = expand_assignments(argv, assignment_cnt);
2518 putenv_all(new_env);
2519 free(new_env); /* optional */
2521 nommu_save->new_env = new_env;
2522 nommu_save->old_env = putenv_all_and_save_old(new_env);
2524 if (argv_expanded) {
2525 argv = argv_expanded;
2527 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2529 nommu_save->argv = argv;
2533 /* On NOMMU, we must never block!
2534 * Example: { sleep 99999 | read line } & echo Ok
2535 * read builtin will block on read syscall, leaving parent blocked
2536 * in vfork. Therefore we can't do this:
2539 /* Check if the command matches any of the builtins.
2540 * Depending on context, this might be redundant. But it's
2541 * easier to waste a few CPU cycles than it is to figure out
2542 * if this is one of those cases.
2546 const struct built_in_command *x;
2547 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2548 if (strcmp(argv[0], x->cmd) == 0) {
2549 debug_printf_exec("running builtin '%s'\n",
2551 rcode = x->function(argv);
2559 #if ENABLE_FEATURE_SH_STANDALONE
2560 /* Check if the command matches any busybox applets */
2561 if (strchr(argv[0], '/') == NULL) {
2562 int a = find_applet_by_name(argv[0]);
2564 #if BB_MMU /* see above why on NOMMU it is not allowed */
2565 if (APPLET_IS_NOEXEC(a)) {
2566 debug_printf_exec("running applet '%s'\n", argv[0]);
2567 run_applet_no_and_exit(a, argv);
2570 /* Re-exec ourselves */
2571 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2572 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2573 execv(bb_busybox_exec_path, argv);
2574 /* If they called chroot or otherwise made the binary no longer
2575 * executable, fall through */
2580 debug_printf_exec("execing '%s'\n", argv[0]);
2581 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2582 execvp(argv[0], argv);
2583 bb_perror_msg("can't exec '%s'", argv[0]);
2584 _exit(EXIT_FAILURE);
2587 static int run_list(struct pipe *pi);
2589 /* Called after [v]fork() in run_pipe
2591 static void pseudo_exec(nommu_save_t *nommu_save,
2592 struct command *command,
2593 char **argv_expanded) NORETURN;
2594 static void pseudo_exec(nommu_save_t *nommu_save,
2595 struct command *command,
2596 char **argv_expanded)
2598 if (command->argv) {
2599 pseudo_exec_argv(nommu_save, command->argv,
2600 command->assignment_cnt, argv_expanded);
2603 if (command->group) {
2604 /* Cases when we are here:
2607 * ... | ( list ) | ...
2608 * ... | { list } | ...
2612 debug_printf_exec("pseudo_exec: run_list\n");
2613 reset_traps_to_defaults();
2614 rcode = run_list(command->group);
2615 /* OK to leak memory by not calling free_pipe_list,
2616 * since this process is about to exit */
2619 re_execute_shell(command->group_as_string, 0);
2623 /* Case when we are here: ... | >file */
2624 debug_printf_exec("pseudo_exec'ed null command\n");
2625 _exit(EXIT_SUCCESS);
2629 static const char *get_cmdtext(struct pipe *pi)
2635 /* This is subtle. ->cmdtext is created only on first backgrounding.
2636 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2637 * On subsequent bg argv is trashed, but we won't use it */
2640 argv = pi->cmds[0].argv;
2641 if (!argv || !argv[0]) {
2642 pi->cmdtext = xzalloc(1);
2647 do len += strlen(*argv) + 1; while (*++argv);
2648 pi->cmdtext = p = xmalloc(len);
2649 argv = pi->cmds[0].argv;
2651 len = strlen(*argv);
2652 memcpy(p, *argv, len);
2660 static void insert_bg_job(struct pipe *pi)
2662 struct pipe *thejob;
2665 /* Linear search for the ID of the job to use */
2667 for (thejob = G.job_list; thejob; thejob = thejob->next)
2668 if (thejob->jobid >= pi->jobid)
2669 pi->jobid = thejob->jobid + 1;
2671 /* Add thejob to the list of running jobs */
2673 thejob = G.job_list = xmalloc(sizeof(*thejob));
2675 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2677 thejob->next = xmalloc(sizeof(*thejob));
2678 thejob = thejob->next;
2681 /* Physically copy the struct job */
2682 memcpy(thejob, pi, sizeof(struct pipe));
2683 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2684 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2685 for (i = 0; i < pi->num_cmds; i++) {
2686 // TODO: do we really need to have so many fields which are just dead weight
2687 // at execution stage?
2688 thejob->cmds[i].pid = pi->cmds[i].pid;
2689 /* all other fields are not used and stay zero */
2691 thejob->next = NULL;
2692 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2694 /* We don't wait for background thejobs to return -- append it
2695 to the list of backgrounded thejobs and leave it alone */
2696 if (G_interactive_fd)
2697 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2698 G.last_bg_pid = thejob->cmds[0].pid;
2699 G.last_jobid = thejob->jobid;
2702 static void remove_bg_job(struct pipe *pi)
2704 struct pipe *prev_pipe;
2706 if (pi == G.job_list) {
2707 G.job_list = pi->next;
2709 prev_pipe = G.job_list;
2710 while (prev_pipe->next != pi)
2711 prev_pipe = prev_pipe->next;
2712 prev_pipe->next = pi->next;
2715 G.last_jobid = G.job_list->jobid;
2720 /* Remove a backgrounded job */
2721 static void delete_finished_bg_job(struct pipe *pi)
2724 pi->stopped_cmds = 0;
2730 /* Check to see if any processes have exited -- if they
2731 * have, figure out why and see if a job has completed */
2732 static int checkjobs(struct pipe* fg_pipe)
2742 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2745 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2746 // /* avoid doing syscall, nothing there anyway */
2749 attributes = WUNTRACED;
2750 if (fg_pipe == NULL)
2751 attributes |= WNOHANG;
2753 /* Do we do this right?
2754 * bash-3.00# sleep 20 | false
2756 * [3]+ Stopped sleep 20 | false
2757 * bash-3.00# echo $?
2758 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2761 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2762 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2763 // + killall -STOP cat
2770 // i = G.count_SIGCHLD;
2771 childpid = waitpid(-1, &status, attributes);
2772 if (childpid <= 0) {
2773 if (childpid && errno != ECHILD)
2774 bb_perror_msg("waitpid");
2775 // else /* Until next SIGCHLD, waitpid's are useless */
2776 // G.handled_SIGCHLD = i;
2779 dead = WIFEXITED(status) || WIFSIGNALED(status);
2782 if (WIFSTOPPED(status))
2783 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2784 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2785 if (WIFSIGNALED(status))
2786 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2787 childpid, WTERMSIG(status), WEXITSTATUS(status));
2788 if (WIFEXITED(status))
2789 debug_printf_jobs("pid %d exited, exitcode %d\n",
2790 childpid, WEXITSTATUS(status));
2792 /* Were we asked to wait for fg pipe? */
2794 for (i = 0; i < fg_pipe->num_cmds; i++) {
2795 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2796 if (fg_pipe->cmds[i].pid != childpid)
2798 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2800 fg_pipe->cmds[i].pid = 0;
2801 fg_pipe->alive_cmds--;
2802 if (i == fg_pipe->num_cmds - 1) {
2803 /* last process gives overall exitstatus */
2804 rcode = WEXITSTATUS(status);
2805 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2808 fg_pipe->cmds[i].is_stopped = 1;
2809 fg_pipe->stopped_cmds++;
2811 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2812 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2813 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2814 /* All processes in fg pipe have exited/stopped */
2816 if (fg_pipe->alive_cmds)
2817 insert_bg_job(fg_pipe);
2821 /* There are still running processes in the fg pipe */
2822 goto wait_more; /* do waitpid again */
2824 /* it wasnt fg_pipe, look for process in bg pipes */
2828 /* We asked to wait for bg or orphaned children */
2829 /* No need to remember exitcode in this case */
2830 for (pi = G.job_list; pi; pi = pi->next) {
2831 for (i = 0; i < pi->num_cmds; i++) {
2832 if (pi->cmds[i].pid == childpid)
2833 goto found_pi_and_prognum;
2836 /* Happens when shell is used as init process (init=/bin/sh) */
2837 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2838 continue; /* do waitpid again */
2840 found_pi_and_prognum:
2843 pi->cmds[i].pid = 0;
2845 if (!pi->alive_cmds) {
2846 if (G_interactive_fd)
2847 printf(JOB_STATUS_FORMAT, pi->jobid,
2848 "Done", pi->cmdtext);
2849 delete_finished_bg_job(pi);
2853 pi->cmds[i].is_stopped = 1;
2857 } /* while (waitpid succeeds)... */
2863 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2866 int rcode = checkjobs(fg_pipe);
2867 /* Job finished, move the shell to the foreground */
2868 p = getpgid(0); /* pgid of our process */
2869 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2870 tcsetpgrp(G_interactive_fd, p);
2875 /* Start all the jobs, but don't wait for anything to finish.
2878 * Return code is normally -1, when the caller has to wait for children
2879 * to finish to determine the exit status of the pipe. If the pipe
2880 * is a simple builtin command, however, the action is done by the
2881 * time run_pipe returns, and the exit code is provided as the
2884 * Returns -1 only if started some children. IOW: we have to
2885 * mask out retvals of builtins etc with 0xff!
2887 * The only case when we do not need to [v]fork is when the pipe
2888 * is single, non-backgrounded, non-subshell command. Examples:
2889 * cmd ; ... { list } ; ...
2890 * cmd && ... { list } && ...
2891 * cmd || ... { list } || ...
2892 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2893 * or (if SH_STANDALONE) an applet, and we can run the { list }
2894 * with run_list(). If it isn't one of these, we fork and exec cmd.
2896 * Cases when we must fork:
2897 * non-single: cmd | cmd
2898 * backgrounded: cmd & { list } &
2899 * subshell: ( list ) [&]
2901 static int run_pipe(struct pipe *pi)
2903 static const char *const null_ptr = NULL;
2906 int pipefds[2]; /* pipefds[0] is for reading */
2907 struct command *command;
2908 char **argv_expanded;
2911 /* it is not always needed, but we aim to smaller code */
2912 int squirrel[] = { -1, -1, -1 };
2915 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2917 USE_HUSH_JOB(pi->pgrp = -1;)
2918 pi->stopped_cmds = 0;
2919 command = &(pi->cmds[0]);
2920 argv_expanded = NULL;
2922 if (pi->num_cmds != 1
2923 || pi->followup == PIPE_BG
2924 || command->grp_type == GRP_SUBSHELL
2931 debug_printf_exec(": group:%p argv:'%s'\n",
2932 command->group, command->argv ? command->argv[0] : "NONE");
2934 if (command->group) {
2935 #if ENABLE_HUSH_FUNCTIONS
2936 if (command->grp_type == GRP_FUNCTION) {
2937 /* func () { list } */
2938 bb_error_msg("here we ought to remember function definition, and go on");
2939 return EXIT_SUCCESS;
2943 debug_printf("non-subshell group\n");
2944 setup_redirects(command, squirrel);
2945 debug_printf_exec(": run_list\n");
2946 rcode = run_list(command->group) & 0xff;
2947 restore_redirects(squirrel);
2948 debug_printf_exec("run_pipe return %d\n", rcode);
2949 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2953 argv = command->argv ? command->argv : (char **) &null_ptr;
2955 const struct built_in_command *x;
2956 char **new_env = NULL;
2957 char **old_env = NULL;
2959 if (argv[command->assignment_cnt] == NULL) {
2960 /* Assignments, but no command */
2961 /* Ensure redirects take effect. Try "a=t >file" */
2962 setup_redirects(command, squirrel);
2963 restore_redirects(squirrel);
2964 /* Set shell variables */
2966 p = expand_string_to_string(*argv);
2967 debug_printf_exec("set shell var:'%s'->'%s'\n",
2969 set_local_var(p, 0, 0);
2972 /* Do we need to flag set_local_var() errors?
2973 * "assignment to readonly var" and "putenv error"
2975 return EXIT_SUCCESS;
2978 /* Expand the rest into (possibly) many strings each */
2979 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2981 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2982 if (strcmp(argv_expanded[0], x->cmd) != 0)
2984 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2985 debug_printf("exec with redirects only\n");
2986 setup_redirects(command, NULL);
2987 rcode = EXIT_SUCCESS;
2988 goto clean_up_and_ret1;
2990 debug_printf("builtin inline %s\n", argv_expanded[0]);
2991 /* XXX setup_redirects acts on file descriptors, not FILEs.
2992 * This is perfect for work that comes after exec().
2993 * Is it really safe for inline use? Experimentally,
2994 * things seem to work with glibc. */
2995 setup_redirects(command, squirrel);
2996 new_env = expand_assignments(argv, command->assignment_cnt);
2997 old_env = putenv_all_and_save_old(new_env);
2998 debug_printf_exec(": builtin '%s' '%s'...\n",
2999 x->cmd, argv_expanded[1]);
3000 rcode = x->function(argv_expanded) & 0xff;
3001 #if ENABLE_FEATURE_SH_STANDALONE
3004 restore_redirects(squirrel);
3005 free_strings_and_unsetenv(new_env, 1);
3006 putenv_all(old_env);
3007 /* Free the pointers, but the strings themselves
3008 * are in environ now, don't use free_strings! */
3011 free(argv_expanded);
3012 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3013 debug_printf_exec("run_pipe return %d\n", rcode);
3016 #if ENABLE_FEATURE_SH_STANDALONE
3017 i = find_applet_by_name(argv_expanded[0]);
3018 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3019 setup_redirects(command, squirrel);
3020 save_nofork_data(&G.nofork_save);
3021 new_env = expand_assignments(argv, command->assignment_cnt);
3022 old_env = putenv_all_and_save_old(new_env);
3023 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3024 argv_expanded[0], argv_expanded[1]);
3025 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3026 goto clean_up_and_ret;
3029 /* It is neither builtin nor applet. We must fork. */
3033 /* NB: argv_expanded may already be created, and that
3034 * might include `cmd` runs! Do not rerun it! We *must*
3035 * use argv_expanded if it's non-NULL */
3037 /* Going to fork a child per each pipe member */
3041 for (i = 0; i < pi->num_cmds; i++) {
3043 volatile nommu_save_t nommu_save;
3044 nommu_save.new_env = NULL;
3045 nommu_save.old_env = NULL;
3046 nommu_save.argv = NULL;
3048 command = &(pi->cmds[i]);
3049 if (command->argv) {
3050 debug_printf_exec(": pipe member '%s' '%s'...\n",
3051 command->argv[0], command->argv[1]);
3053 debug_printf_exec(": pipe member with no argv\n");
3056 /* pipes are inserted between pairs of commands */
3059 if ((i + 1) < pi->num_cmds)
3062 command->pid = BB_MMU ? fork() : vfork();
3063 if (!command->pid) { /* child */
3065 disable_restore_tty_pgrp_on_exit();
3067 /* Every child adds itself to new process group
3068 * with pgid == pid_of_first_child_in_pipe */
3069 if (G.run_list_level == 1 && G_interactive_fd) {
3072 if (pgrp < 0) /* true for 1st process only */
3074 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3075 /* We do it in *every* child, not just first,
3077 tcsetpgrp(G_interactive_fd, pgrp);
3081 xmove_fd(nextin, 0);
3082 xmove_fd(pipefds[1], 1); /* write end */
3084 close(pipefds[0]); /* read end */
3085 /* Like bash, explicit redirects override pipes,
3086 * and the pipe fd is available for dup'ing. */
3087 setup_redirects(command, NULL);
3089 /* Restore default handlers just prior to exec */
3090 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3092 /* Stores to nommu_save list of env vars putenv'ed
3093 * (NOMMU, on MMU we don't need that) */
3094 /* cast away volatility... */
3095 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3096 /* pseudo_exec() does not return */
3099 /* parent or error */
3100 enable_restore_tty_pgrp_on_exit();
3102 /* Clean up after vforked child */
3103 clean_up_after_re_execute();
3104 free(nommu_save.argv);
3105 free_strings_and_unsetenv(nommu_save.new_env, 1);
3106 putenv_all(nommu_save.old_env);
3107 /* Free the pointers, but the strings themselves
3108 * are in environ now, don't use free_strings! */
3109 free(nommu_save.old_env);
3111 free(argv_expanded);
3112 argv_expanded = NULL;
3113 if (command->pid < 0) { /* [v]fork failed */
3114 /* Clearly indicate, was it fork or vfork */
3115 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3119 /* Second and next children need to know pid of first one */
3121 pi->pgrp = command->pid;
3127 if ((i + 1) < pi->num_cmds)
3128 close(pipefds[1]); /* write end */
3129 /* Pass read (output) pipe end to next iteration */
3130 nextin = pipefds[0];
3133 if (!pi->alive_cmds) {
3134 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3138 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3142 #ifndef debug_print_tree
3143 static void debug_print_tree(struct pipe *pi, int lvl)
3145 static const char *const PIPE[] = {
3151 static const char *RES[] = {
3152 [RES_NONE ] = "NONE" ,
3155 [RES_THEN ] = "THEN" ,
3156 [RES_ELIF ] = "ELIF" ,
3157 [RES_ELSE ] = "ELSE" ,
3160 #if ENABLE_HUSH_LOOPS
3161 [RES_FOR ] = "FOR" ,
3162 [RES_WHILE] = "WHILE",
3163 [RES_UNTIL] = "UNTIL",
3165 [RES_DONE ] = "DONE" ,
3167 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3170 #if ENABLE_HUSH_CASE
3171 [RES_CASE ] = "CASE" ,
3172 [RES_MATCH] = "MATCH",
3173 [RES_CASEI] = "CASEI",
3174 [RES_ESAC ] = "ESAC" ,
3176 [RES_XXXX ] = "XXXX" ,
3177 [RES_SNTX ] = "SNTX" ,
3179 static const char *const GRPTYPE[] = {
3182 #if ENABLE_HUSH_FUNCTIONS
3191 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3192 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3194 while (prn < pi->num_cmds) {
3195 struct command *command = &pi->cmds[prn];
3196 char **argv = command->argv;
3198 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3200 command->assignment_cnt);
3201 if (command->group) {
3202 fprintf(stderr, " group %s: (argv=%p)\n",
3203 GRPTYPE[command->grp_type],
3205 debug_print_tree(command->group, lvl+1);
3209 if (argv) while (*argv) {
3210 fprintf(stderr, " '%s'", *argv);
3213 fprintf(stderr, "\n");
3222 /* NB: called by pseudo_exec, and therefore must not modify any
3223 * global data until exec/_exit (we can be a child after vfork!) */
3224 static int run_list(struct pipe *pi)
3226 #if ENABLE_HUSH_CASE
3227 char *case_word = NULL;
3229 #if ENABLE_HUSH_LOOPS
3230 struct pipe *loop_top = NULL;
3231 char *for_varname = NULL;
3232 char **for_lcur = NULL;
3233 char **for_list = NULL;
3235 smallint last_followup;
3237 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3238 smalluint cond_code = 0;
3240 enum { cond_code = 0 };
3243 smallint rword; /* enum reserved_style */
3244 smallint last_rword; /* ditto */
3247 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3249 #if ENABLE_HUSH_LOOPS
3250 /* Check syntax for "for" */
3251 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3252 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3254 /* current word is FOR or IN (BOLD in comments below) */
3255 if (cpipe->next == NULL) {
3256 syntax("malformed for");
3257 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3260 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3261 if (cpipe->next->res_word == RES_DO)
3263 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3264 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3265 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3267 syntax("malformed for");
3268 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3274 /* Past this point, all code paths should jump to ret: label
3275 * in order to return, no direct "return" statements please.
3276 * This helps to ensure that no memory is leaked. */
3278 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3281 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3282 * We are saving state before entering outermost list ("while...done")
3283 * so that ctrl-Z will correctly background _entire_ outermost list,
3284 * not just a part of it (like "sleep 1 | exit 2") */
3285 if (++G.run_list_level == 1 && G_interactive_fd) {
3286 if (sigsetjmp(G.toplevel_jb, 1)) {
3287 /* ctrl-Z forked and we are parent; or ctrl-C.
3288 * Sighandler has longjmped us here */
3289 signal(SIGINT, SIG_IGN);
3290 signal(SIGTSTP, SIG_IGN);
3291 /* Restore level (we can be coming from deep inside
3293 G.run_list_level = 1;
3294 #if ENABLE_FEATURE_SH_STANDALONE
3295 if (G.nofork_save.saved) { /* if save area is valid */
3296 debug_printf_jobs("exiting nofork early\n");
3297 restore_nofork_data(&G.nofork_save);
3300 //// if (G.ctrl_z_flag) {
3301 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3302 //// * Remember this child as background job */
3303 //// insert_bg_job(pi);
3305 /* ctrl-C. We just stop doing whatever we were doing */
3308 USE_HUSH_LOOPS(loop_top = NULL;)
3309 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3313 //// /* ctrl-Z handler will store pid etc in pi */
3314 //// G.toplevel_list = pi;
3315 //// G.ctrl_z_flag = 0;
3316 ////#if ENABLE_FEATURE_SH_STANDALONE
3317 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3319 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3320 //// signal(SIGINT, handler_ctrl_c);
3326 last_rword = RES_XXXX;
3328 last_followup = PIPE_SEQ;
3329 rcode = G.last_exitcode;
3331 /* Go through list of pipes, (maybe) executing them. */
3332 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3336 IF_HAS_KEYWORDS(rword = pi->res_word;)
3337 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3338 rword, cond_code, last_rword);
3339 #if ENABLE_HUSH_LOOPS
3340 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3341 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3343 /* start of a loop: remember where loop starts */
3348 /* Still in the same "if...", "then..." or "do..." branch? */
3349 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3350 if ((rcode == 0 && last_followup == PIPE_OR)
3351 || (rcode != 0 && last_followup == PIPE_AND)
3353 /* It is "<true> || CMD" or "<false> && CMD"
3354 * and we should not execute CMD */
3355 debug_printf_exec("skipped cmd because of || or &&\n");
3356 last_followup = pi->followup;
3360 last_followup = pi->followup;
3361 IF_HAS_KEYWORDS(last_rword = rword;)
3364 if (rword == RES_THEN) {
3365 /* if false; then ... fi has exitcode 0! */
3366 G.last_exitcode = rcode = EXIT_SUCCESS;
3367 /* "if <false> THEN cmd": skip cmd */
3371 if (rword == RES_ELSE || rword == RES_ELIF) {
3372 /* "if <true> then ... ELSE/ELIF cmd":
3373 * skip cmd and all following ones */
3378 #if ENABLE_HUSH_LOOPS
3379 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3381 /* first loop through for */
3383 static const char encoded_dollar_at[] ALIGN1 = {
3384 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3385 }; /* encoded representation of "$@" */
3386 static const char *const encoded_dollar_at_argv[] = {
3387 encoded_dollar_at, NULL
3388 }; /* argv list with one element: "$@" */
3391 vals = (char**)encoded_dollar_at_argv;
3392 if (pi->next->res_word == RES_IN) {
3393 /* if no variable values after "in" we skip "for" */
3394 if (!pi->next->cmds[0].argv) {
3395 G.last_exitcode = rcode = EXIT_SUCCESS;
3396 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3399 vals = pi->next->cmds[0].argv;
3400 } /* else: "for var; do..." -> assume "$@" list */
3401 /* create list of variable values */
3402 debug_print_strings("for_list made from", vals);
3403 for_list = expand_strvec_to_strvec(vals);
3404 for_lcur = for_list;
3405 debug_print_strings("for_list", for_list);
3406 for_varname = pi->cmds[0].argv[0];
3407 pi->cmds[0].argv[0] = NULL;
3409 free(pi->cmds[0].argv[0]);
3411 /* "for" loop is over, clean up */
3415 pi->cmds[0].argv[0] = for_varname;
3418 /* Insert next value from for_lcur */
3419 //TODO: does it need escaping?
3420 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3421 pi->cmds[0].assignment_cnt = 1;
3423 if (rword == RES_IN) {
3424 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3426 if (rword == RES_DONE) {
3427 continue; /* "done" has no cmds too */
3430 #if ENABLE_HUSH_CASE
3431 if (rword == RES_CASE) {
3432 case_word = expand_strvec_to_string(pi->cmds->argv);
3435 if (rword == RES_MATCH) {
3438 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3440 /* all prev words didn't match, does this one match? */
3441 argv = pi->cmds->argv;
3443 char *pattern = expand_string_to_string(*argv);
3444 /* TODO: which FNM_xxx flags to use? */
3445 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3447 if (cond_code == 0) { /* match! we will execute this branch */
3448 free(case_word); /* make future "word)" stop */
3456 if (rword == RES_CASEI) { /* inside of a case branch */
3458 continue; /* not matched yet, skip this pipe */
3461 /* Just pressing <enter> in shell should check for jobs.
3462 * OTOH, in non-interactive shell this is useless
3463 * and only leads to extra job checks */
3464 if (pi->num_cmds == 0) {
3465 if (G_interactive_fd)
3466 goto check_jobs_and_continue;
3470 /* After analyzing all keywords and conditions, we decided
3471 * to execute this pipe. NB: have to do checkjobs(NULL)
3472 * after run_pipe to collect any background children,
3473 * even if list execution is to be stopped. */
3474 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3477 #if ENABLE_HUSH_LOOPS
3478 G.flag_break_continue = 0;
3480 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3482 /* We only ran a builtin: rcode is already known
3483 * and we don't need to wait for anything. */
3484 G.last_exitcode = rcode;
3485 debug_printf_exec(": builtin exitcode %d\n", rcode);
3486 check_and_run_traps(0);
3487 #if ENABLE_HUSH_LOOPS
3488 /* Was it "break" or "continue"? */
3489 if (G.flag_break_continue) {
3490 smallint fbc = G.flag_break_continue;
3491 /* We might fall into outer *loop*,
3492 * don't want to break it too */
3494 G.depth_break_continue--;
3495 if (G.depth_break_continue == 0)
3496 G.flag_break_continue = 0;
3497 /* else: e.g. "continue 2" should *break* once, *then* continue */
3498 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3499 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3500 goto check_jobs_and_break;
3501 /* "continue": simulate end of loop */
3506 } else if (pi->followup == PIPE_BG) {
3507 /* What does bash do with attempts to background builtins? */
3508 /* even bash 3.2 doesn't do that well with nested bg:
3509 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3510 * I'm NOT treating inner &'s as jobs */
3511 check_and_run_traps(0);
3513 if (G.run_list_level == 1)
3516 G.last_exitcode = rcode = EXIT_SUCCESS;
3517 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3520 if (G.run_list_level == 1 && G_interactive_fd) {
3521 /* Waits for completion, then fg's main shell */
3522 rcode = checkjobs_and_fg_shell(pi);
3523 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3524 check_and_run_traps(0);
3527 { /* This one just waits for completion */
3528 rcode = checkjobs(pi);
3529 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3530 check_and_run_traps(0);
3532 G.last_exitcode = rcode;
3536 /* Analyze how result affects subsequent commands */
3538 if (rword == RES_IF || rword == RES_ELIF)
3541 #if ENABLE_HUSH_LOOPS
3542 /* Beware of "while false; true; do ..."! */
3543 if (pi->next && pi->next->res_word == RES_DO) {
3544 if (rword == RES_WHILE) {
3546 /* "while false; do...done" - exitcode 0 */
3547 G.last_exitcode = rcode = EXIT_SUCCESS;
3548 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3549 goto check_jobs_and_break;
3552 if (rword == RES_UNTIL) {
3554 debug_printf_exec(": until expr is true: breaking\n");
3555 check_jobs_and_break:
3563 check_jobs_and_continue:
3568 //// if (G.ctrl_z_flag) {
3569 //// /* ctrl-Z forked somewhere in the past, we are the child,
3570 //// * and now we completed running the list. Exit. */
3576 //// if (!G.run_list_level && G_interactive_fd) {
3577 //// signal(SIGTSTP, SIG_IGN);
3578 //// signal(SIGINT, SIG_IGN);
3581 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3582 #if ENABLE_HUSH_LOOPS
3587 #if ENABLE_HUSH_CASE
3593 /* Select which version we will use */
3594 static int run_and_free_list(struct pipe *pi)
3597 debug_printf_exec("run_and_free_list entered\n");
3599 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3600 rcode = run_list(pi);
3602 /* free_pipe_list has the side effect of clearing memory.
3603 * In the long run that function can be merged with run_list,
3604 * but doing that now would hobble the debugging effort. */
3605 free_pipe_list(pi, /* indent: */ 0);
3606 debug_printf_exec("run_and_free_list return %d\n", rcode);
3611 static struct pipe *new_pipe(void)
3614 pi = xzalloc(sizeof(struct pipe));
3615 /*pi->followup = 0; - deliberately invalid value */
3616 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3620 /* Command (member of a pipe) is complete. The only possible error here
3621 * is out of memory, in which case xmalloc exits. */
3622 static int done_command(struct parse_context *ctx)
3624 /* The command is really already in the pipe structure, so
3625 * advance the pipe counter and make a new, null command. */
3626 struct pipe *pi = ctx->pipe;
3627 struct command *command = ctx->command;
3630 if (command->group == NULL
3631 && command->argv == NULL
3632 && command->redirects == NULL
3634 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3635 memset(command, 0, sizeof(*command)); /* paranoia */
3636 return pi->num_cmds;
3639 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3640 //debug_print_tree(ctx->list_head, 20);
3642 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3645 /* Only real trickiness here is that the uncommitted
3646 * command structure is not counted in pi->num_cmds. */
3647 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3648 command = &pi->cmds[pi->num_cmds];
3649 memset(command, 0, sizeof(*command));
3651 ctx->command = command;
3652 /* but ctx->pipe and ctx->list_head remain unchanged */
3654 return pi->num_cmds; /* used only for 0/nonzero check */
3657 static void done_pipe(struct parse_context *ctx, pipe_style type)
3661 debug_printf_parse("done_pipe entered, followup %d\n", type);
3662 /* Close previous command */
3663 not_null = done_command(ctx);
3664 ctx->pipe->followup = type;
3666 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3667 ctx->ctx_inverted = 0;
3668 ctx->pipe->res_word = ctx->ctx_res_w;
3671 /* Without this check, even just <enter> on command line generates
3672 * tree of three NOPs (!). Which is harmless but annoying.
3673 * IOW: it is safe to do it unconditionally.
3674 * RES_NONE case is for "for a in; do ..." (empty IN set)
3675 * and other cases to work. */
3678 || ctx->ctx_res_w == RES_FI
3679 || ctx->ctx_res_w == RES_DONE
3680 || ctx->ctx_res_w == RES_FOR
3681 || ctx->ctx_res_w == RES_IN
3682 || ctx->ctx_res_w == RES_ESAC
3686 debug_printf_parse("done_pipe: adding new pipe: "
3687 "not_null:%d ctx->ctx_res_w:%d\n",
3688 not_null, ctx->ctx_res_w);
3690 ctx->pipe->next = new_p;
3692 /* RES_THEN, RES_DO etc are "sticky" -
3693 * they remain set for commands inside if/while.
3694 * This is used to control execution.
3695 * RES_FOR and RES_IN are NOT sticky (needed to support
3696 * cases where variable or value happens to match a keyword):
3698 #if ENABLE_HUSH_LOOPS
3699 if (ctx->ctx_res_w == RES_FOR
3700 || ctx->ctx_res_w == RES_IN)
3701 ctx->ctx_res_w = RES_NONE;
3703 #if ENABLE_HUSH_CASE
3704 if (ctx->ctx_res_w == RES_MATCH)
3705 ctx->ctx_res_w = RES_CASEI;
3707 ctx->command = NULL; /* trick done_command below */
3708 /* Create the memory for command, roughly:
3709 * ctx->pipe->cmds = new struct command;
3710 * ctx->command = &ctx->pipe->cmds[0];
3713 //debug_print_tree(ctx->list_head, 10);
3715 debug_printf_parse("done_pipe return\n");
3718 static void initialize_context(struct parse_context *ctx)
3720 memset(ctx, 0, sizeof(*ctx));
3721 ctx->pipe = ctx->list_head = new_pipe();
3722 /* Create the memory for command, roughly:
3723 * ctx->pipe->cmds = new struct command;
3724 * ctx->command = &ctx->pipe->cmds[0];
3729 /* If a reserved word is found and processed, parse context is modified
3730 * and 1 is returned.
3733 struct reserved_combo {
3736 unsigned char assignment_flag;
3740 FLAG_END = (1 << RES_NONE ),
3742 FLAG_IF = (1 << RES_IF ),
3743 FLAG_THEN = (1 << RES_THEN ),
3744 FLAG_ELIF = (1 << RES_ELIF ),
3745 FLAG_ELSE = (1 << RES_ELSE ),
3746 FLAG_FI = (1 << RES_FI ),
3748 #if ENABLE_HUSH_LOOPS
3749 FLAG_FOR = (1 << RES_FOR ),
3750 FLAG_WHILE = (1 << RES_WHILE),
3751 FLAG_UNTIL = (1 << RES_UNTIL),
3752 FLAG_DO = (1 << RES_DO ),
3753 FLAG_DONE = (1 << RES_DONE ),
3754 FLAG_IN = (1 << RES_IN ),
3756 #if ENABLE_HUSH_CASE
3757 FLAG_MATCH = (1 << RES_MATCH),
3758 FLAG_ESAC = (1 << RES_ESAC ),
3760 FLAG_START = (1 << RES_XXXX ),
3763 static const struct reserved_combo* match_reserved_word(o_string *word)
3765 /* Mostly a list of accepted follow-up reserved words.
3766 * FLAG_END means we are done with the sequence, and are ready
3767 * to turn the compound list into a command.
3768 * FLAG_START means the word must start a new compound list.
3770 static const struct reserved_combo reserved_list[] = {
3772 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3773 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3774 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3775 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3776 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3777 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3779 #if ENABLE_HUSH_LOOPS
3780 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3781 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3782 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3783 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3784 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3785 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3787 #if ENABLE_HUSH_CASE
3788 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3789 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3792 const struct reserved_combo *r;
3794 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3795 if (strcmp(word->data, r->literal) == 0)
3800 static int reserved_word(o_string *word, struct parse_context *ctx)
3802 #if ENABLE_HUSH_CASE
3803 static const struct reserved_combo reserved_match = {
3804 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3807 const struct reserved_combo *r;
3809 r = match_reserved_word(word);
3813 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3814 #if ENABLE_HUSH_CASE
3815 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3816 /* "case word IN ..." - IN part starts first match part */
3817 r = &reserved_match;
3820 if (r->flag == 0) { /* '!' */
3821 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3822 syntax("! ! command");
3823 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3825 ctx->ctx_inverted = 1;
3828 if (r->flag & FLAG_START) {
3829 struct parse_context *old;
3830 old = xmalloc(sizeof(*old));
3831 debug_printf_parse("push stack %p\n", old);
3832 *old = *ctx; /* physical copy */
3833 initialize_context(ctx);
3835 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3837 ctx->ctx_res_w = RES_SNTX;
3840 ctx->ctx_res_w = r->res;
3841 ctx->old_flag = r->flag;
3842 if (ctx->old_flag & FLAG_END) {
3843 struct parse_context *old;
3844 done_pipe(ctx, PIPE_SEQ);
3845 debug_printf_parse("pop stack %p\n", ctx->stack);
3847 old->command->group = ctx->list_head;
3848 old->command->grp_type = GRP_NORMAL;
3850 o_addstr(&old->as_string, ctx->as_string.data);
3851 o_free_unsafe(&ctx->as_string);
3852 old->command->group_as_string = xstrdup(old->as_string.data);
3853 debug_printf_parse("pop, remembering as:'%s'\n",
3854 old->command->group_as_string);
3856 *ctx = *old; /* physical copy */
3859 word->o_assignment = r->assignment_flag;
3864 /* Word is complete, look at it and update parsing context.
3865 * Normal return is 0. Syntax errors return 1.
3866 * Note: on return, word is reset, but not o_free'd!
3868 static int done_word(o_string *word, struct parse_context *ctx)
3870 struct command *command = ctx->command;
3872 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3873 if (word->length == 0 && word->o_quoted == 0) {
3874 debug_printf_parse("done_word return 0: true null, ignored\n");
3877 /* If this word wasn't an assignment, next ones definitely
3878 * can't be assignments. Even if they look like ones. */
3879 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3880 && word->o_assignment != WORD_IS_KEYWORD
3882 word->o_assignment = NOT_ASSIGNMENT;
3884 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3885 command->assignment_cnt++;
3886 word->o_assignment = MAYBE_ASSIGNMENT;
3889 if (ctx->pending_redirect) {
3890 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3891 * only if run as "bash", not "sh" */
3892 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3894 * ...the word that follows the redirection operator
3895 * shall be subjected to tilde expansion, parameter expansion,
3896 * command substitution, arithmetic expansion, and quote
3897 * removal. Pathname expansion shall not be performed
3898 * on the word by a non-interactive shell; an interactive
3899 * shell may perform it, but shall do so only when
3900 * the expansion would result in one word."
3902 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3903 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3906 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3908 word->o_assignment = NOT_ASSIGNMENT;
3909 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3911 /* "{ echo foo; } echo bar" - bad */
3912 /* NB: bash allows e.g.:
3913 * if true; then { echo foo; } fi
3914 * while if false; then false; fi do break; done
3916 * while if false; then false; fi; do; break; done
3918 if (command->group) {
3920 debug_printf_parse("done_word return 1: syntax error, "
3921 "groups and arglists don't mix\n");
3925 #if ENABLE_HUSH_CASE
3926 if (ctx->ctx_dsemicolon
3927 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3929 /* already done when ctx_dsemicolon was set to 1: */
3930 /* ctx->ctx_res_w = RES_MATCH; */
3931 ctx->ctx_dsemicolon = 0;
3934 if (!command->argv /* if it's the first word... */
3935 #if ENABLE_HUSH_LOOPS
3936 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3937 && ctx->ctx_res_w != RES_IN
3940 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3941 if (reserved_word(word, ctx)) {
3943 debug_printf_parse("done_word return %d\n",
3944 (ctx->ctx_res_w == RES_SNTX));
3945 return (ctx->ctx_res_w == RES_SNTX);
3949 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
3950 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3951 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3952 /* (otherwise it's known to be not empty and is already safe) */
3954 /* exclude "$@" - it can expand to no word despite "" */
3955 char *p = word->data;
3956 while (p[0] == SPECIAL_VAR_SYMBOL
3957 && (p[1] & 0x7f) == '@'
3958 && p[2] == SPECIAL_VAR_SYMBOL
3962 if (p == word->data || p[0] != '\0') {
3963 /* saw no "$@", or not only "$@" but some
3964 * real text is there too */
3965 /* insert "empty variable" reference, this makes
3966 * e.g. "", $empty"" etc to not disappear */
3967 o_addchr(word, SPECIAL_VAR_SYMBOL);
3968 o_addchr(word, SPECIAL_VAR_SYMBOL);
3971 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3972 debug_print_strings("word appended to argv", command->argv);
3976 ctx->pending_redirect = NULL;
3978 #if ENABLE_HUSH_LOOPS
3979 /* Force FOR to have just one word (variable name) */
3980 /* NB: basically, this makes hush see "for v in ..." syntax as if
3981 * as it is "for v; in ...". FOR and IN become two pipe structs
3983 if (ctx->ctx_res_w == RES_FOR) {
3984 //TODO: check that command->argv[0] is a valid variable name!
3985 done_pipe(ctx, PIPE_SEQ);
3988 #if ENABLE_HUSH_CASE
3989 /* Force CASE to have just one word */
3990 if (ctx->ctx_res_w == RES_CASE) {
3991 done_pipe(ctx, PIPE_SEQ);
3994 debug_printf_parse("done_word return 0\n");
3999 /* Peek ahead in the input to find out if we have a "&n" construct,
4000 * as in "2>&1", that represents duplicating a file descriptor.
4001 * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
4002 * -2 (syntax error), -1 if no & was seen, or the number found.
4005 #define redirect_dup_num(as_string, input) \
4006 redirect_dup_num(input)
4008 static int redirect_dup_num(o_string *as_string, struct in_str *input)
4016 ch = i_getch(input); /* get the & */
4017 nommu_addchr(as_string, ch);
4020 ch = i_getch(input);
4021 nommu_addchr(as_string, ch);
4022 return REDIRFD_CLOSE;
4026 while (ch != EOF && isdigit(ch)) {
4027 d = d*10 + (ch-'0');
4029 ch = i_getch(input);
4030 nommu_addchr(as_string, ch);
4035 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4037 bb_error_msg("ambiguous redirect");
4041 /* Return code is 0 normally, 1 if a syntax error is detected
4043 static int parse_redirect(struct parse_context *ctx,
4046 struct in_str *input)
4048 struct command *command = ctx->command;
4049 struct redir_struct *redir;
4050 struct redir_struct **redirp;
4054 if (style != REDIRECT_HEREDOC) {
4055 /* Check for a '2>&1' type redirect */
4056 dup_num = redirect_dup_num(&ctx->as_string, input);
4058 return 1; /* syntax error */
4060 int ch = i_peek(input);
4061 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4062 if (dup_num) { /* <<-... */
4063 ch = i_getch(input);
4064 nommu_addchr(&ctx->as_string, ch);
4067 /* <<[-] word is the same as <<[-]word */
4068 while (ch == ' ' || ch == '\t') {
4069 ch = i_getch(input);
4070 nommu_addchr(&ctx->as_string, ch);
4075 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
4076 int ch = i_peek(input);
4078 /* >|FILE redirect ("clobbering" >).
4079 * Since we do not support "set -o noclobber" yet,
4080 * >| and > are the same for now. Just eat |.
4082 ch = i_getch(input);
4083 nommu_addchr(&ctx->as_string, ch);
4087 /* Create a new redir_struct and append it to the linked list */
4088 redirp = &command->redirects;
4089 while ((redir = *redirp) != NULL) {
4090 redirp = &(redir->next);
4092 *redirp = redir = xzalloc(sizeof(*redir));
4093 /* redir->next = NULL; */
4094 /* redir->rd_filename = NULL; */
4095 redir->rd_type = style;
4096 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4098 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4099 redir_table[style].descrip);
4101 redir->rd_dup = dup_num;
4102 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4103 /* Erik had a check here that the file descriptor in question
4104 * is legit; I postpone that to "run time"
4105 * A "-" representation of "close me" shows up as a -3 here */
4106 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4107 redir->rd_fd, redir->rd_dup);
4109 /* Set ctx->pending_redirect, so we know what to do at the
4110 * end of the next parsed word. */
4111 ctx->pending_redirect = redir;
4116 /* If a redirect is immediately preceded by a number, that number is
4117 * supposed to tell which file descriptor to redirect. This routine
4118 * looks for such preceding numbers. In an ideal world this routine
4119 * needs to handle all the following classes of redirects...
4120 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4121 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4122 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4123 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4125 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4127 * ... If n is quoted, the number shall not be recognized as part of
4128 * the redirection expression. For example:
4130 * writes the character 2 into file a"
4131 * We are getting it right by setting ->o_quoted on any \<char>
4133 * A -1 return means no valid number was found,
4134 * the caller should use the appropriate default for this redirection.
4136 static int redirect_opt_num(o_string *o)
4140 if (o->data == NULL)
4142 num = bb_strtou(o->data, NULL, 10);
4143 if (errno || num < 0)
4150 #define fetch_till_str(as_string, input, word, skip_tabs) \
4151 fetch_till_str(input, word, skip_tabs)
4153 static char *fetch_till_str(o_string *as_string,
4154 struct in_str *input,
4158 o_string heredoc = NULL_O_STRING;
4164 ch = i_getch(input);
4165 nommu_addchr(as_string, ch);
4167 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4168 heredoc.data[past_EOL] = '\0';
4169 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4170 return heredoc.data;
4173 o_addchr(&heredoc, ch);
4174 past_EOL = heredoc.length;
4177 ch = i_getch(input);
4178 nommu_addchr(as_string, ch);
4179 } while (skip_tabs && ch == '\t');
4180 } while (ch == '\n');
4183 o_free_unsafe(&heredoc);
4186 o_addchr(&heredoc, ch);
4187 nommu_addchr(as_string, ch);
4191 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4192 * and load them all. There should be exactly heredoc_cnt of them.
4194 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4196 struct pipe *pi = ctx->list_head;
4200 struct command *cmd = pi->cmds;
4202 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4204 cmd->argv ? cmd->argv[0] : "NONE");
4205 for (i = 0; i < pi->num_cmds; i++) {
4206 struct redir_struct *redir = cmd->redirects;
4208 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4209 i, cmd->argv ? cmd->argv[0] : "NONE");
4211 if (redir->rd_type == REDIRECT_HEREDOC) {
4214 if (heredoc_cnt <= 0) {
4215 syntax("heredoc BUG 1");
4216 return 1; /* error */
4218 redir->rd_type = REDIRECT_HEREDOC2;
4219 /* redir->dup is (ab)used to indicate <<- */
4220 p = fetch_till_str(&ctx->as_string, input,
4221 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4223 syntax("unexpected EOF in here document");
4226 free(redir->rd_filename);
4227 redir->rd_filename = p;
4230 redir = redir->next;
4236 /* Should be 0. If it isn't, it's a parse error */
4238 syntax("heredoc BUG 2");
4244 #define parse_stream(pstring, input, end_trigger) \
4245 parse_stream(input, end_trigger)
4247 static struct pipe *parse_stream(char **pstring,
4248 struct in_str *input,
4250 static void parse_and_run_string(const char *s);
4252 #if ENABLE_HUSH_TICK
4253 static FILE *generate_stream_from_string(const char *s)
4256 int pid, channel[2];
4259 pid = BB_MMU ? fork() : vfork();
4261 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4263 if (pid == 0) { /* child */
4264 disable_restore_tty_pgrp_on_exit();
4265 /* Process substitution is not considered to be usual
4266 * 'command execution'.
4267 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4274 close(channel[0]); /* NB: close _first_, then move fd! */
4275 xmove_fd(channel[1], 1);
4276 /* Prevent it from trying to handle ctrl-z etc */
4277 USE_HUSH_JOB(G.run_list_level = 1;)
4279 reset_traps_to_defaults();
4280 parse_and_run_string(s);
4281 _exit(G.last_exitcode);
4283 /* We re-execute after vfork on NOMMU. This makes this script safe:
4284 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4285 * huge=`cat BIG` # was blocking here forever
4288 re_execute_shell(s, 0);
4293 enable_restore_tty_pgrp_on_exit();
4294 clean_up_after_re_execute();
4296 pf = fdopen(channel[0], "r");
4300 /* Return code is exit status of the process that is run. */
4301 static int process_command_subs(o_string *dest, const char *s)
4304 struct in_str pipe_str;
4307 pf = generate_stream_from_string(s);
4310 close_on_exec_on(fileno(pf));
4312 /* Now send results of command back into original context */
4313 setup_file_in_str(&pipe_str, pf);
4315 while ((ch = i_getch(&pipe_str)) != EOF) {
4321 o_addchr(dest, '\n');
4324 o_addQchr(dest, ch);
4327 debug_printf("done reading from pipe, pclose()ing\n");
4328 /* Note: we got EOF, and we just close the read end of the pipe.
4329 * We do not wait for the `cmd` child to terminate. bash and ash do.
4331 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4332 * `false`; echo $? - bash outputs "1"
4335 debug_printf("closed FILE from child. return 0\n");
4340 static int parse_group(o_string *dest, struct parse_context *ctx,
4341 struct in_str *input, int ch)
4343 /* dest contains characters seen prior to ( or {.
4344 * Typically it's empty, but for function defs,
4345 * it contains function name (without '()'). */
4346 struct pipe *pipe_list;
4348 struct command *command = ctx->command;
4350 debug_printf_parse("parse_group entered\n");
4351 #if ENABLE_HUSH_FUNCTIONS
4352 if (ch == 'F') { /* function definition? */
4353 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4354 //command->fname = dest->data;
4355 command->grp_type = GRP_FUNCTION;
4356 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4357 memset(dest, 0, sizeof(*dest));
4360 if (command->argv /* word [word](... */
4361 || dest->length /* word(... */
4362 || dest->o_quoted /* ""(... */
4365 debug_printf_parse("parse_group return 1: "
4366 "syntax error, groups and arglists don't mix\n");
4372 command->grp_type = GRP_SUBSHELL;
4376 char *as_string = NULL;
4378 pipe_list = parse_stream(&as_string, input, endch);
4381 o_addstr(&ctx->as_string, as_string);
4383 /* empty ()/{} or parse error? */
4384 if (!pipe_list || pipe_list == ERR_PTR) {
4389 debug_printf_parse("parse_group return 1: "
4390 "parse_stream returned %p\n", pipe_list);
4393 command->group = pipe_list;
4395 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4396 command->group_as_string = as_string;
4397 debug_printf_parse("end of group, remembering as:'%s'\n",
4398 command->group_as_string);
4401 debug_printf_parse("parse_group return 0\n");
4403 /* command remains "open", available for possible redirects */
4406 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4407 /* Subroutines for copying $(...) and `...` things */
4408 static int add_till_backquote(o_string *dest, struct in_str *input);
4410 static int add_till_single_quote(o_string *dest, struct in_str *input)
4413 int ch = i_getch(input);
4415 syntax("unterminated '");
4423 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4424 static int add_till_double_quote(o_string *dest, struct in_str *input)
4427 int ch = i_getch(input);
4429 syntax("unterminated \"");
4434 if (ch == '\\') { /* \x. Copy both chars. */
4436 ch = i_getch(input);
4440 if (add_till_backquote(dest, input))
4445 //if (ch == '$') ...
4448 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4450 * "Within the backquoted style of command substitution, backslash
4451 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4452 * The search for the matching backquote shall be satisfied by the first
4453 * backquote found without a preceding backslash; during this search,
4454 * if a non-escaped backquote is encountered within a shell comment,
4455 * a here-document, an embedded command substitution of the $(command)
4456 * form, or a quoted string, undefined results occur. A single-quoted
4457 * or double-quoted string that begins, but does not end, within the
4458 * "`...`" sequence produces undefined results."
4460 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4462 static int add_till_backquote(o_string *dest, struct in_str *input)
4465 int ch = i_getch(input);
4467 syntax("unterminated `");
4473 /* \x. Copy both chars unless it is \` */
4474 int ch2 = i_getch(input);
4476 syntax("unterminated `");
4479 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4486 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4487 * quoting and nested ()s.
4488 * "With the $(command) style of command substitution, all characters
4489 * following the open parenthesis to the matching closing parenthesis
4490 * constitute the command. Any valid shell script can be used for command,
4491 * except a script consisting solely of redirections which produces
4492 * unspecified results."
4494 * echo $(echo '(TEST)' BEST) (TEST) BEST
4495 * echo $(echo 'TEST)' BEST) TEST) BEST
4496 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4498 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4502 int ch = i_getch(input);
4504 syntax("unterminated )");
4513 if (i_peek(input) == ')') {
4521 if (add_till_single_quote(dest, input))
4527 if (add_till_double_quote(dest, input))
4533 /* \x. Copy verbatim. Important for \(, \) */
4534 ch = i_getch(input);
4536 syntax("unterminated )");
4545 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4547 /* Return code: 0 for OK, 1 for syntax error */
4549 #define handle_dollar(as_string, dest, input) \
4550 handle_dollar(dest, input)
4552 static int handle_dollar(o_string *as_string,
4554 struct in_str *input)
4557 int ch = i_peek(input); /* first character after the $ */
4558 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4560 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4562 ch = i_getch(input);
4563 nommu_addchr(as_string, ch);
4565 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4567 debug_printf_parse(": '%c'\n", ch);
4568 o_addchr(dest, ch | quote_mask);
4571 if (!isalnum(ch) && ch != '_')
4573 ch = i_getch(input);
4574 nommu_addchr(as_string, ch);
4576 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4577 } else if (isdigit(ch)) {
4579 ch = i_getch(input);
4580 nommu_addchr(as_string, ch);
4581 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4582 debug_printf_parse(": '%c'\n", ch);
4583 o_addchr(dest, ch | quote_mask);
4584 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4585 } else switch (ch) {
4587 case '!': /* last bg pid */
4588 case '?': /* last exit code */
4589 case '#': /* number of args */
4590 case '*': /* args */
4591 case '@': /* args */
4592 goto make_one_char_var;
4594 bool first_char, all_digits;
4596 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4597 ch = i_getch(input);
4598 nommu_addchr(as_string, ch);
4599 /* XXX maybe someone will try to escape the '}' */
4604 ch = i_getch(input);
4605 nommu_addchr(as_string, ch);
4611 /* ${#var}: length of var contents */
4613 else if (isdigit(ch)) {
4620 && ( (all_digits && !isdigit(ch))
4621 || (!all_digits && !isalnum(ch) && ch != '_')
4624 /* handle parameter expansions
4625 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4630 case ':': /* null modifier */
4631 if (expansion == 0) {
4632 debug_printf_parse(": null modifier\n");
4637 case '#': /* remove prefix */
4638 case '%': /* remove suffix */
4639 if (expansion == 0) {
4640 debug_printf_parse(": remove suffix/prefix\n");
4645 case '-': /* default value */
4646 case '=': /* assign default */
4647 case '+': /* alternative */
4648 case '?': /* error indicate */
4649 debug_printf_parse(": parameter expansion\n");
4654 syntax("unterminated ${name}");
4655 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4660 debug_printf_parse(": '%c'\n", ch);
4661 o_addchr(dest, ch | quote_mask);
4665 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4668 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4673 ch = i_getch(input);
4674 nommu_addchr(as_string, ch);
4675 # if ENABLE_SH_MATH_SUPPORT
4676 if (i_peek(input) == '(') {
4677 ch = i_getch(input);
4678 nommu_addchr(as_string, ch);
4679 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4680 o_addchr(dest, /*quote_mask |*/ '+');
4684 if (add_till_closing_paren(dest, input, true))
4688 o_addstr(as_string, dest->data + pos);
4689 o_addchr(as_string, ')');
4690 o_addchr(as_string, ')');
4693 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4697 # if ENABLE_HUSH_TICK
4698 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4699 o_addchr(dest, quote_mask | '`');
4703 if (add_till_closing_paren(dest, input, false))
4707 o_addstr(as_string, dest->data + pos);
4708 o_addchr(as_string, '`');
4711 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4717 ch = i_getch(input);
4718 nommu_addchr(as_string, ch);
4720 if (isalnum(ch)) { /* it's $_name or $_123 */
4726 /* $_ Shell or shell script name; or last cmd name */
4727 /* $- Option flags set by set builtin or shell options (-i etc) */
4729 o_addQchr(dest, '$');
4731 debug_printf_parse("handle_dollar return 0\n");
4736 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4737 parse_stream_dquoted(dest, input, dquote_end)
4739 static int parse_stream_dquoted(o_string *as_string,
4741 struct in_str *input,
4748 ch = i_getch(input);
4750 nommu_addchr(as_string, ch);
4751 if (ch == dquote_end) { /* may be only '"' or EOF */
4752 if (dest->o_assignment == NOT_ASSIGNMENT)
4753 dest->o_escape ^= 1;
4754 debug_printf_parse("parse_stream_dquoted return 0\n");
4757 /* note: can't move it above ch == dquote_end check! */
4759 syntax("unterminated \"");
4760 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4765 next = i_peek(input);
4767 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4768 ch, ch, dest->o_escape);
4772 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4776 * "The backslash retains its special meaning [in "..."]
4777 * only when followed by one of the following characters:
4778 * $, `, ", \, or <newline>. A double quote may be quoted
4779 * within double quotes by preceding it with a backslash.
4780 * If enabled, history expansion will be performed unless
4781 * an ! appearing in double quotes is escaped using
4782 * a backslash. The backslash preceding the ! is not removed."
4784 if (strchr("$`\"\\", next) != NULL) {
4785 o_addqchr(dest, i_getch(input));
4787 o_addqchr(dest, '\\');
4792 if (handle_dollar(as_string, dest, input) != 0) {
4793 debug_printf_parse("parse_stream_dquoted return 1: "
4794 "handle_dollar returned non-0\n");
4799 #if ENABLE_HUSH_TICK
4801 //int pos = dest->length;
4802 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4803 o_addchr(dest, 0x80 | '`');
4804 if (add_till_backquote(dest, input))
4806 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4807 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4811 o_addQchr(dest, ch);
4813 && (dest->o_assignment == MAYBE_ASSIGNMENT
4814 || dest->o_assignment == WORD_IS_KEYWORD)
4815 && is_assignment(dest->data)
4817 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4823 * Scan input until EOF or end_trigger char.
4824 * Return a list of pipes to execute, or NULL on EOF
4825 * or if end_trigger character is met.
4826 * On syntax error, exit is shell is not interactive,
4827 * reset parsing machinery and start parsing anew,
4828 * or return ERR_PTR.
4830 static struct pipe *parse_stream(char **pstring,
4831 struct in_str *input,
4834 struct parse_context ctx;
4835 o_string dest = NULL_O_STRING;
4839 /* Double-quote state is handled in the state variable is_in_dquote.
4840 * A single-quote triggers a bypass of the main loop until its mate is
4841 * found. When recursing, quote state is passed in via dest->o_escape.
4843 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4844 end_trigger ? : 'X');
4846 G.ifs = get_local_var_value("IFS");
4851 #if ENABLE_HUSH_INTERACTIVE
4852 input->promptmode = 0; /* PS1 */
4854 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4855 initialize_context(&ctx);
4860 const char *is_special;
4864 redir_type redir_style;
4867 /* dest.o_quoted = 1; - already is (see below) */
4868 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4871 /* We reached closing '"' */
4874 ch = i_getch(input);
4875 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4876 ch, ch, dest.o_escape);
4881 syntax("unterminated here document");
4884 if (done_word(&dest, &ctx)) {
4888 done_pipe(&ctx, PIPE_SEQ);
4890 /* If we got nothing... */
4891 // TODO: test script consisting of just "&"
4892 if (pi->num_cmds == 0
4893 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4895 free_pipe_list(pi, 0);
4898 debug_printf_parse("parse_stream return %p\n", pi);
4900 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4902 *pstring = ctx.as_string.data;
4904 o_free_unsafe(&ctx.as_string);
4908 nommu_addchr(&ctx.as_string, ch);
4909 is_ifs = strchr(G.ifs, ch);
4910 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4911 "\\$\"" USE_HUSH_TICK("`") /* always special */
4914 if (!is_special && !is_ifs) { /* ordinary char */
4915 o_addQchr(&dest, ch);
4916 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4917 || dest.o_assignment == WORD_IS_KEYWORD)
4919 && is_assignment(dest.data)
4921 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4927 if (done_word(&dest, &ctx)) {
4931 #if ENABLE_HUSH_CASE
4932 /* "case ... in <newline> word) ..." -
4933 * newlines are ignored (but ';' wouldn't be) */
4934 if (ctx.command->argv == NULL
4935 && ctx.ctx_res_w == RES_MATCH
4940 /* Treat newline as a command separator. */
4941 done_pipe(&ctx, PIPE_SEQ);
4942 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4944 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4949 dest.o_assignment = MAYBE_ASSIGNMENT;
4951 /* note: if (is_ifs) continue;
4952 * will still trigger for us */
4955 if (end_trigger && end_trigger == ch
4956 && (heredoc_cnt == 0 || end_trigger != ';')
4958 //TODO: disallow "{ cmd }" without semicolon
4960 /* This is technically valid:
4961 * { cat <<HERE; }; echo Ok
4966 * but we don't support this.
4967 * We require heredoc to be in enclosing {}/(),
4970 syntax("unterminated here document");
4973 if (done_word(&dest, &ctx)) {
4976 done_pipe(&ctx, PIPE_SEQ);
4977 dest.o_assignment = MAYBE_ASSIGNMENT;
4978 /* Do we sit outside of any if's, loops or case's? */
4980 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4982 debug_printf_parse("parse_stream return %p: "
4983 "end_trigger char found\n",
4987 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4989 *pstring = ctx.as_string.data;
4991 o_free_unsafe(&ctx.as_string);
4993 return ctx.list_head;
4999 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
5000 /* ch is a special char and thus this word
5001 * cannot be an assignment */
5002 dest.o_assignment = NOT_ASSIGNMENT;
5007 next = i_peek(input);
5012 if (dest.length == 0) {
5015 if (ch == EOF || ch == '\n')
5018 /* note: we do not add it to &ctx.as_string */
5020 nommu_addchr(&ctx.as_string, '\n');
5022 o_addQchr(&dest, ch);
5030 o_addchr(&dest, '\\');
5031 ch = i_getch(input);
5032 nommu_addchr(&ctx.as_string, ch);
5033 o_addchr(&dest, ch);
5034 /* Example: echo Hello \2>file
5035 * we need to know that word 2 is quoted */
5039 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5040 debug_printf_parse("parse_stream parse error: "
5041 "handle_dollar returned non-0\n");
5048 ch = i_getch(input);
5050 syntax("unterminated '");
5053 nommu_addchr(&ctx.as_string, ch);
5056 if (dest.o_assignment == NOT_ASSIGNMENT)
5057 o_addqchr(&dest, ch);
5059 o_addchr(&dest, ch);
5064 is_in_dquote ^= 1; /* invert */
5065 if (dest.o_assignment == NOT_ASSIGNMENT)
5068 #if ENABLE_HUSH_TICK
5073 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5074 o_addchr(&dest, '`');
5078 if (add_till_backquote(&dest, input))
5081 o_addstr(&ctx.as_string, dest.data + pos);
5082 o_addchr(&ctx.as_string, '`');
5084 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5085 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5090 redir_fd = redirect_opt_num(&dest);
5091 if (done_word(&dest, &ctx)) {
5094 redir_style = REDIRECT_OVERWRITE;
5096 redir_style = REDIRECT_APPEND;
5097 ch = i_getch(input);
5098 nommu_addchr(&ctx.as_string, ch);
5101 else if (next == '(') {
5102 syntax(">(process) not supported");
5106 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5110 redir_fd = redirect_opt_num(&dest);
5111 if (done_word(&dest, &ctx)) {
5114 redir_style = REDIRECT_INPUT;
5116 redir_style = REDIRECT_HEREDOC;
5118 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5119 ch = i_getch(input);
5120 nommu_addchr(&ctx.as_string, ch);
5121 } else if (next == '>') {
5122 redir_style = REDIRECT_IO;
5123 ch = i_getch(input);
5124 nommu_addchr(&ctx.as_string, ch);
5127 else if (next == '(') {
5128 syntax("<(process) not supported");
5132 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5136 #if ENABLE_HUSH_CASE
5139 if (done_word(&dest, &ctx)) {
5142 done_pipe(&ctx, PIPE_SEQ);
5143 #if ENABLE_HUSH_CASE
5144 /* Eat multiple semicolons, detect
5145 * whether it means something special */
5150 ch = i_getch(input);
5151 nommu_addchr(&ctx.as_string, ch);
5152 if (ctx.ctx_res_w == RES_CASEI) {
5153 ctx.ctx_dsemicolon = 1;
5154 ctx.ctx_res_w = RES_MATCH;
5160 /* We just finished a cmd. New one may start
5161 * with an assignment */
5162 dest.o_assignment = MAYBE_ASSIGNMENT;
5165 if (done_word(&dest, &ctx)) {
5169 ch = i_getch(input);
5170 nommu_addchr(&ctx.as_string, ch);
5171 done_pipe(&ctx, PIPE_AND);
5173 done_pipe(&ctx, PIPE_BG);
5177 if (done_word(&dest, &ctx)) {
5180 #if ENABLE_HUSH_CASE
5181 if (ctx.ctx_res_w == RES_MATCH)
5182 break; /* we are in case's "word | word)" */
5184 if (next == '|') { /* || */
5185 ch = i_getch(input);
5186 nommu_addchr(&ctx.as_string, ch);
5187 done_pipe(&ctx, PIPE_OR);
5189 /* we could pick up a file descriptor choice here
5190 * with redirect_opt_num(), but bash doesn't do it.
5191 * "echo foo 2| cat" yields "foo 2". */
5196 #if ENABLE_HUSH_CASE
5197 /* "case... in [(]word)..." - skip '(' */
5198 if (ctx.ctx_res_w == RES_MATCH
5199 && ctx.command->argv == NULL /* not (word|(... */
5200 && dest.length == 0 /* not word(... */
5201 && dest.o_quoted == 0 /* not ""(... */
5206 #if ENABLE_HUSH_FUNCTIONS
5207 if (dest.length != 0 /* not just () but word() */
5208 && dest.o_quoted == 0 /* not a"b"c() */
5209 && ctx.command->argv == NULL /* it's the first word */
5210 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5211 && i_peek(input) == ')'
5212 && !match_reserved_word(&dest)
5214 bb_error_msg("seems like a function definition");
5216 //if !BB_MMU o_addchr(&ctx.as_string...
5218 //TODO: do it properly.
5219 ch = i_getch(input);
5220 } while (ch == ' ' || ch == '\n');
5222 syntax("was expecting {");
5225 ch = 'F'; /* magic value */
5229 if (parse_group(&dest, &ctx, input, ch) != 0) {
5234 #if ENABLE_HUSH_CASE
5235 if (ctx.ctx_res_w == RES_MATCH)
5239 /* proper use of this character is caught by end_trigger:
5240 * if we see {, we call parse_group(..., end_trigger='}')
5241 * and it will match } earlier (not here). */
5242 syntax("unexpected } or )");
5246 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5252 struct parse_context *pctx;
5253 IF_HAS_KEYWORDS(struct parse_context *p2;)
5255 /* Clean up allocated tree.
5256 * Samples for finding leaks on syntax error recovery path.
5257 * Run them from interactive shell, watch pmap `pidof hush`.
5258 * while if false; then false; fi do break; done
5260 * while if false; then false; fi; do break; fi
5261 * Samples to catch leaks at execution:
5262 * while if (true | {true;}); then echo ok; fi; do break; done
5263 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5267 /* Update pipe/command counts,
5268 * otherwise freeing may miss some */
5269 done_pipe(pctx, PIPE_SEQ);
5270 debug_printf_clean("freeing list %p from ctx %p\n",
5271 pctx->list_head, pctx);
5272 debug_print_tree(pctx->list_head, 0);
5273 free_pipe_list(pctx->list_head, 0);
5274 debug_printf_clean("freed list %p\n", pctx->list_head);
5276 o_free_unsafe(&pctx->as_string);
5278 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5282 IF_HAS_KEYWORDS(pctx = p2;)
5283 } while (HAS_KEYWORDS && pctx);
5284 /* Free text, clear all dest fields */
5286 /* If we are not in top-level parse, we return,
5287 * our caller will propagate error.
5289 if (end_trigger != ';') {
5296 /* Discard cached input, force prompt */
5298 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5303 /* Executing from string: eval, sh -c '...'
5304 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5305 * end_trigger controls how often we stop parsing
5306 * NUL: parse all, execute, return
5307 * ';': parse till ';' or newline, execute, repeat till EOF
5309 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5312 struct pipe *pipe_list;
5314 pipe_list = parse_stream(NULL, inp, end_trigger);
5315 if (!pipe_list) /* EOF */
5317 debug_print_tree(pipe_list, 0);
5318 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5319 run_and_free_list(pipe_list);
5323 static void parse_and_run_string(const char *s)
5325 struct in_str input;
5326 setup_string_in_str(&input, s);
5327 parse_and_run_stream(&input, '\0');
5330 static void parse_and_run_file(FILE *f)
5332 struct in_str input;
5333 setup_file_in_str(&input, f);
5334 parse_and_run_stream(&input, ';');
5337 /* Called a few times only (or even once if "sh -c") */
5338 static void block_signals(int second_time)
5343 mask = (1 << SIGQUIT);
5344 if (G_interactive_fd) {
5348 //TODO | (1 << SIGHUP)
5350 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5355 G.non_DFL_mask = mask;
5358 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5362 sigaddset(&G.blocked_set, sig);
5366 sigdelset(&G.blocked_set, SIGCHLD);
5368 sigprocmask(SIG_SETMASK, &G.blocked_set,
5369 second_time ? NULL : &G.inherited_set);
5370 /* POSIX allows shell to re-enable SIGCHLD
5371 * even if it was SIG_IGN on entry */
5372 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5374 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5379 static void maybe_set_to_sigexit(int sig)
5381 void (*handler)(int);
5382 /* non_DFL_mask'ed signals are, well, masked,
5383 * no need to set handler for them.
5385 if (!((G.non_DFL_mask >> sig) & 1)) {
5386 handler = signal(sig, sigexit);
5387 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5388 signal(sig, handler);
5391 /* Set handlers to restore tty pgrp and exit */
5392 static void set_fatal_handlers(void)
5394 /* We _must_ restore tty pgrp on fatal signals */
5396 maybe_set_to_sigexit(SIGILL );
5397 maybe_set_to_sigexit(SIGFPE );
5398 maybe_set_to_sigexit(SIGBUS );
5399 maybe_set_to_sigexit(SIGSEGV);
5400 maybe_set_to_sigexit(SIGTRAP);
5401 } /* else: hush is perfect. what SEGV? */
5402 maybe_set_to_sigexit(SIGABRT);
5403 /* bash 3.2 seems to handle these just like 'fatal' ones */
5404 maybe_set_to_sigexit(SIGPIPE);
5405 maybe_set_to_sigexit(SIGALRM);
5406 //TODO: disable and move down when proper SIGHUP handling is added
5407 maybe_set_to_sigexit(SIGHUP );
5408 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5409 * if we aren't interactive... but in this case
5410 * we never want to restore pgrp on exit, and this fn is not called */
5411 /*maybe_set_to_sigexit(SIGTERM);*/
5412 /*maybe_set_to_sigexit(SIGINT );*/
5416 static int set_mode(const char cstate, const char mode)
5418 int state = (cstate == '-' ? 1 : 0);
5420 case 'n': G.fake_mode = state; break;
5421 case 'x': /*G.debug_mode = state;*/ break;
5422 default: return EXIT_FAILURE;
5424 return EXIT_SUCCESS;
5427 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5428 int hush_main(int argc, char **argv)
5430 static const struct variable const_shell_ver = {
5432 .varstr = (char*)hush_version_str,
5433 .max_len = 1, /* 0 can provoke free(name) */
5437 int signal_mask_is_inited = 0;
5440 struct variable *cur_var;
5443 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5444 G.last_exitcode = EXIT_SUCCESS;
5446 G.argv0_for_re_execing = argv[0];
5448 /* Deal with HUSH_VERSION */
5449 G.shell_ver = const_shell_ver; /* copying struct here */
5450 G.top_var = &G.shell_ver;
5451 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5452 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5453 /* Initialize our shell local variables with the values
5454 * currently living in the environment */
5455 cur_var = G.top_var;
5458 char *value = strchr(*e, '=');
5459 if (value) { /* paranoia */
5460 cur_var->next = xzalloc(sizeof(*cur_var));
5461 cur_var = cur_var->next;
5462 cur_var->varstr = *e;
5463 cur_var->max_len = strlen(*e);
5464 cur_var->flg_export = 1;
5468 debug_printf_env("putenv '%s'\n", hush_version_str);
5469 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5470 #if ENABLE_FEATURE_EDITING
5471 G.line_input_state = new_line_input_t(FOR_SHELL);
5473 G.global_argc = argc;
5474 G.global_argv = argv;
5475 /* Initialize some more globals to non-zero values */
5477 #if ENABLE_HUSH_INTERACTIVE
5478 if (ENABLE_FEATURE_EDITING)
5479 cmdedit_set_initial_prompt();
5483 /* Shell is non-interactive at first. We need to call
5484 * block_signals(0) if we are going to execute "sh <script>",
5485 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5486 * If we later decide that we are interactive, we run block_signals(0)
5487 * (or re-run block_signals(1) if we ran block_signals(0) before)
5488 * in order to intercept (more) signals.
5492 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5494 opt = getopt(argc, argv, "c:xins"
5504 G.root_pid = getpid();
5505 G.global_argv = argv + optind;
5506 if (!argv[optind]) {
5507 /* -c 'script' (no params): prevent empty $0 */
5508 *--G.global_argv = argv[0];
5510 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5511 G.global_argc = argc - optind;
5512 block_signals(0); /* 0: called 1st time */
5513 parse_and_run_string(optarg);
5516 /* Well, we cannot just declare interactiveness,
5517 * we have to have some stuff (ctty, etc) */
5518 /* G_interactive_fd++; */
5521 /* "-s" means "read from stdin", but this is how we always
5522 * operate, so simply do nothing here. */
5525 case '<': /* "big heredoc" support */
5526 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5529 G.root_pid = bb_strtou(optarg, &optarg, 16);
5531 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5533 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5534 # if ENABLE_HUSH_LOOPS
5536 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5541 set_local_var(xstrdup(optarg), 0, opt == 'R');
5546 if (!set_mode('-', opt))
5550 fprintf(stderr, "Usage: sh [FILE]...\n"
5551 " or: sh -c command [args]...\n\n");
5557 } /* option parsing loop */
5560 G.root_pid = getpid();
5562 /* If we are login shell... */
5563 if (argv[0] && argv[0][0] == '-') {
5565 /* XXX what should argv be while sourcing /etc/profile? */
5566 debug_printf("sourcing /etc/profile\n");
5567 input = fopen_for_read("/etc/profile");
5568 if (input != NULL) {
5569 close_on_exec_on(fileno(input));
5570 block_signals(0); /* 0: called 1st time */
5571 signal_mask_is_inited = 1;
5572 parse_and_run_file(input);
5575 /* bash: after sourcing /etc/profile,
5576 * tries to source (in the given order):
5577 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5578 * stopping of first found. --noprofile turns this off.
5579 * bash also sources ~/.bash_logout on exit.
5580 * If called as sh, skips .bash_XXX files.
5587 * "bash <script>" (which is never interactive (unless -i?))
5588 * sources $BASH_ENV here (without scanning $PATH).
5589 * If called as sh, does the same but with $ENV.
5591 debug_printf("running script '%s'\n", argv[optind]);
5592 G.global_argv = argv + optind;
5593 G.global_argc = argc - optind;
5594 input = xfopen_for_read(argv[optind]);
5595 close_on_exec_on(fileno(input));
5596 if (!signal_mask_is_inited)
5597 block_signals(0); /* 0: called 1st time */
5598 parse_and_run_file(input);
5599 #if ENABLE_FEATURE_CLEAN_UP
5605 /* Up to here, shell was non-interactive. Now it may become one.
5606 * NB: don't forget to (re)run block_signals(0/1) as needed.
5609 /* A shell is interactive if the '-i' flag was given, or if all of
5610 * the following conditions are met:
5612 * no arguments remaining or the -s flag given
5613 * standard input is a terminal
5614 * standard output is a terminal
5615 * Refer to Posix.2, the description of the 'sh' utility.
5618 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5619 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5620 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5621 //TODO: "interactive" and "have job control" are two different things.
5622 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5623 //should stay on! Currently, we mix these into one.
5624 if (G.saved_tty_pgrp >= 0) {
5625 /* try to dup stdin to high fd#, >= 255 */
5626 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5627 if (G_interactive_fd < 0) {
5628 /* try to dup to any fd */
5629 G_interactive_fd = dup(STDIN_FILENO);
5630 if (G_interactive_fd < 0)
5632 G_interactive_fd = 0;
5634 // TODO: track & disallow any attempts of user
5635 // to (inadvertently) close/redirect it
5638 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5639 if (G_interactive_fd) {
5642 /* We are indeed interactive shell, and we will perform
5643 * job control. Setting up for that. */
5645 close_on_exec_on(G_interactive_fd);
5646 /* If we were run as 'hush &', sleep until we are
5647 * in the foreground (tty pgrp == our pgrp).
5648 * If we get started under a job aware app (like bash),
5649 * make sure we are now in charge so we don't fight over
5650 * who gets the foreground */
5652 shell_pgrp = getpgrp();
5653 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5654 if (G.saved_tty_pgrp == shell_pgrp)
5656 /* send TTIN to ourself (should stop us) */
5657 kill(- shell_pgrp, SIGTTIN);
5659 /* Block some signals */
5660 block_signals(signal_mask_is_inited);
5661 /* Set other signals to restore saved_tty_pgrp */
5662 set_fatal_handlers();
5663 /* Put ourselves in our own process group */
5664 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5665 /* Grab control of the terminal */
5666 tcsetpgrp(G_interactive_fd, getpid());
5667 /* -1 is special - makes xfuncs longjmp, not exit
5668 * (we reset die_sleep = 0 whereever we [v]fork) */
5669 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5670 if (setjmp(die_jmp)) {
5671 /* xfunc has failed! die die die */
5672 hush_exit(xfunc_error_retval);
5674 } else if (!signal_mask_is_inited) {
5675 block_signals(0); /* 0: called 1st time */
5676 } /* else: block_signals(0) was done before */
5677 #elif ENABLE_HUSH_INTERACTIVE
5678 /* No job control compiled in, only prompt/line editing */
5679 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5680 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5681 if (G_interactive_fd < 0) {
5682 /* try to dup to any fd */
5683 G_interactive_fd = dup(STDIN_FILENO);
5684 if (G_interactive_fd < 0)
5686 G_interactive_fd = 0;
5689 if (G_interactive_fd) {
5690 close_on_exec_on(G_interactive_fd);
5691 block_signals(signal_mask_is_inited);
5692 } else if (!signal_mask_is_inited) {
5696 /* We have interactiveness code disabled */
5697 if (!signal_mask_is_inited) {
5702 * if interactive but not a login shell, sources ~/.bashrc
5703 * (--norc turns this off, --rcfile <file> overrides)
5706 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5707 printf("\n\n%s hush - the humble shell\n", bb_banner);
5708 printf("Enter 'help' for a list of built-in commands.\n\n");
5711 parse_and_run_file(stdin);
5714 #if ENABLE_FEATURE_CLEAN_UP
5715 if (G.cwd != bb_msg_unknown)
5717 cur_var = G.top_var->next;
5719 struct variable *tmp = cur_var;
5720 if (!cur_var->max_len)
5721 free(cur_var->varstr);
5722 cur_var = cur_var->next;
5726 hush_exit(G.last_exitcode);
5731 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5732 int lash_main(int argc, char **argv)
5734 //bb_error_msg("lash is deprecated, please use hush instead");
5735 return hush_main(argc, argv);
5743 static int builtin_trap(char **argv)
5750 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5754 /* No args: print all trapped. This isn't 100% correct as we
5755 * should be escaping the cmd so that it can be pasted back in
5757 for (i = 0; i < NSIG; ++i)
5759 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5760 return EXIT_SUCCESS;
5765 /* If first arg is decimal: reset all specified signals */
5766 sig = bb_strtou(*argv, NULL, 10);
5772 sig = get_signum(*argv++);
5773 if (sig < 0 || sig >= NSIG) {
5775 /* Mimic bash message exactly */
5776 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5781 G.traps[sig] = xstrdup(new_cmd);
5783 debug_printf("trap: setting SIG%s (%i) to '%s'",
5784 get_signame(sig), sig, G.traps[sig]);
5786 /* There is no signal for 0 (EXIT) */
5791 sigaddset(&G.blocked_set, sig);
5793 /* There was a trap handler, we are removing it
5794 * (if sig has non-DFL handling,
5795 * we don't need to do anything) */
5796 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5798 sigdelset(&G.blocked_set, sig);
5800 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5805 /* First arg is "-": reset all specified to default */
5806 /* First arg is "": ignore all specified */
5807 /* Everything else: execute first arg upon signal */
5809 bb_error_msg("trap: invalid arguments");
5810 return EXIT_FAILURE;
5812 if (NOT_LONE_DASH(*argv))
5818 static int builtin_true(char **argv UNUSED_PARAM)
5823 static int builtin_test(char **argv)
5830 return test_main(argc, argv - argc);
5833 static int builtin_echo(char **argv)
5840 return echo_main(argc, argv - argc);
5843 static int builtin_eval(char **argv)
5845 int rcode = EXIT_SUCCESS;
5848 char *str = expand_strvec_to_string(argv);
5850 * eval "echo Hi; done" ("done" is syntax error):
5851 * "echo Hi" will not execute too.
5853 parse_and_run_string(str);
5855 rcode = G.last_exitcode;
5860 static int builtin_cd(char **argv)
5862 const char *newdir = argv[1];
5863 if (newdir == NULL) {
5864 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5865 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5867 newdir = getenv("HOME") ? : "/";
5869 if (chdir(newdir)) {
5870 /* Mimic bash message exactly */
5871 bb_perror_msg("cd: %s", newdir);
5872 return EXIT_FAILURE;
5875 return EXIT_SUCCESS;
5878 static int builtin_exec(char **argv)
5880 if (*++argv == NULL)
5881 return EXIT_SUCCESS; /* bash does this */
5886 // FIXME: if exec fails, bash does NOT exit! We do...
5887 pseudo_exec_argv(&dummy, argv, 0, NULL);
5892 static int builtin_exit(char **argv)
5894 debug_printf_exec("%s()\n", __func__);
5895 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5896 //puts("exit"); /* bash does it */
5897 // TODO: warn if we have background jobs: "There are stopped jobs"
5898 // On second consecutive 'exit', exit anyway.
5899 if (*++argv == NULL)
5900 hush_exit(G.last_exitcode);
5901 /* mimic bash: exit 123abc == exit 255 + error msg */
5902 xfunc_error_retval = 255;
5903 /* bash: exit -2 == exit 254, no error msg */
5904 hush_exit(xatoi(*argv) & 0xff);
5907 static int builtin_export(char **argv)
5909 if (*++argv == NULL) {
5911 // ash emits: export VAR='VAL'
5912 // bash: declare -x VAR="VAL"
5913 // (both also escape as needed (quotes, $, etc))
5918 return EXIT_SUCCESS;
5925 value = strchr(name, '=');
5927 /* They are exporting something without a =VALUE */
5928 struct variable *var;
5930 var = get_local_var(name);
5932 var->flg_export = 1;
5933 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5934 putenv(var->varstr);
5936 /* bash does not return an error when trying to export
5937 * an undefined variable. Do likewise. */
5940 set_local_var(xstrdup(name), 1, 0);
5943 return EXIT_SUCCESS;
5947 /* built-in 'fg' and 'bg' handler */
5948 static int builtin_fg_bg(char **argv)
5953 if (!G_interactive_fd)
5954 return EXIT_FAILURE;
5955 /* If they gave us no args, assume they want the last backgrounded task */
5957 for (pi = G.job_list; pi; pi = pi->next) {
5958 if (pi->jobid == G.last_jobid) {
5962 bb_error_msg("%s: no current job", argv[0]);
5963 return EXIT_FAILURE;
5965 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5966 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5967 return EXIT_FAILURE;
5969 for (pi = G.job_list; pi; pi = pi->next) {
5970 if (pi->jobid == jobnum) {
5974 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5975 return EXIT_FAILURE;
5977 // TODO: bash prints a string representation
5978 // of job being foregrounded (like "sleep 1 | cat")
5979 if (argv[0][0] == 'f') {
5980 /* Put the job into the foreground. */
5981 tcsetpgrp(G_interactive_fd, pi->pgrp);
5984 /* Restart the processes in the job */
5985 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5986 for (i = 0; i < pi->num_cmds; i++) {
5987 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5988 pi->cmds[i].is_stopped = 0;
5990 pi->stopped_cmds = 0;
5992 i = kill(- pi->pgrp, SIGCONT);
5994 if (errno == ESRCH) {
5995 delete_finished_bg_job(pi);
5996 return EXIT_SUCCESS;
5998 bb_perror_msg("kill (SIGCONT)");
6001 if (argv[0][0] == 'f') {
6003 return checkjobs_and_fg_shell(pi);
6005 return EXIT_SUCCESS;
6009 #if ENABLE_HUSH_HELP
6010 static int builtin_help(char **argv UNUSED_PARAM)
6012 const struct built_in_command *x;
6015 "Built-in commands:\n"
6016 "------------------\n");
6017 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6018 printf("%s\t%s\n", x->cmd, x->descr);
6021 return EXIT_SUCCESS;
6026 static int builtin_jobs(char **argv UNUSED_PARAM)
6029 const char *status_string;
6031 for (job = G.job_list; job; job = job->next) {
6032 if (job->alive_cmds == job->stopped_cmds)
6033 status_string = "Stopped";
6035 status_string = "Running";
6037 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6039 return EXIT_SUCCESS;
6044 static int builtin_memleak(char **argv UNUSED_PARAM)
6049 /* Crude attempt to find where "free memory" starts,
6050 * sans fragmentation. */
6052 l = (unsigned long)p;
6055 if (l < (unsigned long)p) l = (unsigned long)p;
6058 if (!G.memleak_value)
6059 G.memleak_value = l;
6061 l -= G.memleak_value;
6068 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6073 static int builtin_pwd(char **argv UNUSED_PARAM)
6076 return EXIT_SUCCESS;
6079 static int builtin_read(char **argv)
6082 const char *name = argv[1] ? argv[1] : "REPLY";
6083 //TODO: check that argv[1] is a valid variable name
6085 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6086 return set_local_var(string, 0, 0);
6089 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6090 * built-in 'set' handler
6092 * set [-abCefhmnuvx] [-o option] [argument...]
6093 * set [+abCefhmnuvx] [+o option] [argument...]
6094 * set -- [argument...]
6097 * Implementations shall support the options in both their hyphen and
6098 * plus-sign forms. These options can also be specified as options to sh.
6100 * Write out all variables and their values: set
6101 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6102 * Turn on the -x and -v options: set -xv
6103 * Unset all positional parameters: set --
6104 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6105 * Set the positional parameters to the expansion of x, even if x expands
6106 * with a leading '-' or '+': set -- $x
6108 * So far, we only support "set -- [argument...]" and some of the short names.
6110 static int builtin_set(char **argv)
6113 char **pp, **g_argv;
6114 char *arg = *++argv;
6118 for (e = G.top_var; e; e = e->next)
6120 return EXIT_SUCCESS;
6124 if (!strcmp(arg, "--")) {
6129 if (arg[0] == '+' || arg[0] == '-') {
6130 for (n = 1; arg[n]; ++n)
6131 if (set_mode(arg[0], arg[n]))
6137 } while ((arg = *++argv) != NULL);
6138 /* Now argv[0] is 1st argument */
6140 /* Only reset global_argv if we didn't process anything */
6142 return EXIT_SUCCESS;
6145 /* NB: G.global_argv[0] ($0) is never freed/changed */
6146 g_argv = G.global_argv;
6147 if (G.global_args_malloced) {
6153 G.global_args_malloced = 1;
6154 pp = xzalloc(sizeof(pp[0]) * 2);
6155 pp[0] = g_argv[0]; /* retain $0 */
6158 /* This realloc's G.global_argv */
6159 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6166 return EXIT_SUCCESS;
6168 /* Nothing known, so abort */
6170 bb_error_msg("set: %s: invalid option", arg);
6171 return EXIT_FAILURE;
6174 static int builtin_shift(char **argv)
6180 if (n >= 0 && n < G.global_argc) {
6181 if (G.global_args_malloced) {
6184 free(G.global_argv[m++]);
6187 memmove(&G.global_argv[1], &G.global_argv[n+1],
6188 G.global_argc * sizeof(G.global_argv[0]));
6189 return EXIT_SUCCESS;
6191 return EXIT_FAILURE;
6194 static int builtin_source(char **argv)
6198 if (*++argv == NULL)
6199 return EXIT_FAILURE;
6201 /* XXX search through $PATH is missing */
6202 input = fopen_or_warn(*argv, "r");
6204 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6205 return EXIT_FAILURE;
6207 close_on_exec_on(fileno(input));
6209 /* Now run the file */
6211 /* XXX argv and argc are broken; need to save old G.global_argv
6212 * (pointer only is OK!) on this stack frame,
6213 * set G.global_argv=argv+1, recurse, and restore. */
6214 parse_and_run_file(input);
6216 return G.last_exitcode;
6219 static int builtin_umask(char **argv)
6222 const char *arg = argv[1];
6224 //TODO: umask may take chmod-like symbolic masks
6225 new_umask = bb_strtou(arg, NULL, 8);
6227 //Message? bash examples:
6228 //bash: umask: 'q': invalid symbolic mode operator
6229 //bash: umask: 999: octal number out of range
6230 return EXIT_FAILURE;
6233 new_umask = umask(0);
6234 printf("%.3o\n", (unsigned) new_umask);
6235 /* fall through and restore new_umask which we set to 0 */
6238 return EXIT_SUCCESS;
6241 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6242 static int builtin_unset(char **argv)
6248 return EXIT_SUCCESS;
6251 if (argv[0][0] == '-') {
6252 switch (argv[0][1]) {
6258 bb_error_msg("unset: %s: invalid option", *argv);
6259 return EXIT_FAILURE;
6261 //TODO: disallow "unset -vf ..." too
6268 if (unset_local_var(*argv)) {
6269 /* unset <nonexistent_var> doesn't fail.
6270 * Error is when one tries to unset RO var.
6271 * Message was printed by unset_local_var. */
6275 #if ENABLE_HUSH_FUNCTIONS
6277 unset_local_func(*argv);
6285 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6286 static int builtin_wait(char **argv)
6288 int ret = EXIT_SUCCESS;
6291 if (*++argv == NULL) {
6292 /* Don't care about wait results */
6293 /* Note 1: must wait until there are no more children */
6294 /* Note 2: must be interruptible */
6296 * $ sleep 3 & sleep 6 & wait
6301 * $ sleep 3 & sleep 6 & wait
6305 * ^C <-- after ~4 sec from keyboard
6308 sigaddset(&G.blocked_set, SIGCHLD);
6309 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6312 if (errno == ECHILD)
6314 /* Wait for SIGCHLD or any other signal of interest */
6315 /* sigtimedwait with infinite timeout: */
6316 sig = sigwaitinfo(&G.blocked_set, NULL);
6318 sig = check_and_run_traps(sig);
6319 if (sig && sig != SIGCHLD) { /* see note 2 */
6325 sigdelset(&G.blocked_set, SIGCHLD);
6326 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6330 /* This is probably buggy wrt interruptible-ness */
6332 pid_t pid = bb_strtou(*argv, NULL, 10);
6334 /* mimic bash message */
6335 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6336 return EXIT_FAILURE;
6338 if (waitpid(pid, &status, 0) == pid) {
6339 if (WIFSIGNALED(status))
6340 ret = 128 + WTERMSIG(status);
6341 else if (WIFEXITED(status))
6342 ret = WEXITSTATUS(status);
6346 bb_perror_msg("wait %s", *argv);
6355 #if ENABLE_HUSH_LOOPS
6356 static int builtin_break(char **argv)
6358 if (G.depth_of_loop == 0) {
6359 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6360 return EXIT_SUCCESS; /* bash compat */
6362 G.flag_break_continue++; /* BC_BREAK = 1 */
6363 G.depth_break_continue = 1;
6365 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6366 if (errno || !G.depth_break_continue || argv[2]) {
6367 bb_error_msg("%s: bad arguments", argv[0]);
6368 G.flag_break_continue = BC_BREAK;
6369 G.depth_break_continue = UINT_MAX;
6372 if (G.depth_of_loop < G.depth_break_continue)
6373 G.depth_break_continue = G.depth_of_loop;
6374 return EXIT_SUCCESS;
6377 static int builtin_continue(char **argv)
6379 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6380 return builtin_break(argv);