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.
67 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 /* #include <dmalloc.h> */
76 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
80 /* Debug build knobs */
81 #define LEAK_HUNTING 0
82 #define BUILD_AS_NOMMU 0
83 /* Enable/disable sanity checks. Ok to enable in production,
84 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
85 * Keeping 1 for now even in released versions.
89 #define ENABLE_HUSH_FUNCTIONS 0
97 # define USE_FOR_NOMMU(...) __VA_ARGS__
98 # define USE_FOR_MMU(...)
101 #if defined SINGLE_APPLET_MAIN
102 /* STANDALONE does not make sense, and won't compile */
103 #undef CONFIG_FEATURE_SH_STANDALONE
104 #undef ENABLE_FEATURE_SH_STANDALONE
105 #undef USE_FEATURE_SH_STANDALONE
106 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #define ENABLE_FEATURE_SH_STANDALONE 0
108 #define USE_FEATURE_SH_STANDALONE(...)
109 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
112 #if !ENABLE_HUSH_INTERACTIVE
113 #undef ENABLE_FEATURE_EDITING
114 #define ENABLE_FEATURE_EDITING 0
115 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
116 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
119 /* Do we support ANY keywords? */
120 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
121 #define HAS_KEYWORDS 1
122 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
123 #define IF_HAS_NO_KEYWORDS(...)
125 #define HAS_KEYWORDS 0
126 #define IF_HAS_KEYWORDS(...)
127 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
130 /* If you comment out one of these below, it will be #defined later
131 * to perform debug printfs to stderr: */
132 #define debug_printf(...) do {} while (0)
133 /* Finer-grained debug switches */
134 #define debug_printf_parse(...) do {} while (0)
135 #define debug_print_tree(a, b) do {} while (0)
136 #define debug_printf_exec(...) do {} while (0)
137 #define debug_printf_env(...) do {} while (0)
138 #define debug_printf_jobs(...) do {} while (0)
139 #define debug_printf_expand(...) do {} while (0)
140 #define debug_printf_glob(...) do {} while (0)
141 #define debug_printf_list(...) do {} while (0)
142 #define debug_printf_subst(...) do {} while (0)
143 #define debug_printf_clean(...) do {} while (0)
146 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_parse
150 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_exec
154 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_env
158 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
161 #ifndef debug_printf_jobs
162 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
168 #ifndef debug_printf_expand
169 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
170 #define DEBUG_EXPAND 1
172 #define DEBUG_EXPAND 0
175 #ifndef debug_printf_glob
176 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_list
183 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_subst
187 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
190 #ifndef debug_printf_clean
191 /* broken, of course, but OK for testing */
192 static const char *indenter(int i)
194 static const char blanks[] ALIGN1 =
196 return &blanks[sizeof(blanks) - i - 1];
198 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
199 #define DEBUG_CLEAN 1
201 #define DEBUG_CLEAN 0
205 static void debug_print_strings(const char *prefix, char **vv)
207 fprintf(stderr, "%s:\n", prefix);
209 fprintf(stderr, " '%s'\n", *vv++);
212 #define debug_print_strings(prefix, vv) ((void)0)
215 #define ERR_PTR ((void*)(long)1)
217 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
219 #define SPECIAL_VAR_SYMBOL 3
221 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
223 /* This supports saving pointers malloced in vfork child,
224 * to be freed in the parent. One pointer is saved in
225 * G.argv_from_re_execing global var instead. TODO: unify.
228 typedef struct nommu_save_t {
235 /* The descrip member of this structure is only used to make
236 * debugging output pretty */
237 static const struct {
239 signed char default_fd;
243 { O_RDONLY, 0, "<" },
244 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
245 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
246 { O_RDONLY, 0, "<<" },
247 { O_CREAT|O_RDWR, 1, "<>" },
248 /* Should not be needed. Bogus default_fd helps in debugging */
249 /* { O_RDONLY, 77, "<<" }, */
252 typedef enum reserved_style {
261 #if ENABLE_HUSH_LOOPS
268 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
273 /* two pseudo-keywords support contrived "case" syntax: */
274 RES_MATCH , /* "word)" */
275 RES_CASEI , /* "this command is inside CASE" */
282 typedef struct o_string {
284 int length; /* position where data is appended */
286 /* Protect newly added chars against globbing
287 * (by prepending \ to *, ?, [, \) */
290 /* At least some part of the string was inside '' or "",
291 * possibly empty one: word"", wo''rd etc. */
293 smallint has_empty_slot;
294 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
297 MAYBE_ASSIGNMENT = 0,
298 DEFINITELY_ASSIGNMENT = 1,
300 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
302 /* Used for initialization: o_string foo = NULL_O_STRING; */
303 #define NULL_O_STRING { NULL }
305 /* I can almost use ordinary FILE*. Is open_memstream() universally
306 * available? Where is it documented? */
307 typedef struct in_str {
309 /* eof_flag=1: last char in ->p is really an EOF */
310 char eof_flag; /* meaningless if ->p == NULL */
312 #if ENABLE_HUSH_INTERACTIVE
314 smallint promptmode; /* 0: PS1, 1: PS2 */
317 int (*get) (struct in_str *);
318 int (*peek) (struct in_str *);
320 #define i_getch(input) ((input)->get(input))
321 #define i_peek(input) ((input)->peek(input))
323 struct redir_struct {
324 struct redir_struct *next;
325 char *rd_filename; /* filename */
326 int rd_fd; /* fd to redirect */
327 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
329 smallint rd_type; /* (enum redir_type) */
330 /* note: for heredocs, rd_filename contains heredoc delimiter,
331 * and subsequently heredoc itself; and rd_dup is a bitmask:
332 * 1: do we need to trim leading tabs?
333 * 2: is heredoc quoted (<<'dleim' syntax) ?
336 typedef enum redir_type {
337 REDIRECT_INVALID = 0,
339 REDIRECT_OVERWRITE = 2,
341 REDIRECT_HEREDOC = 4,
343 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
346 REDIRFD_SYNTAX_ERR = -2,
347 REDIRFD_TO_FILE = -1, /* otherwise, rd_fd if redirected to rd_dup */
349 HEREDOC_SKIPTABS = 1,
355 pid_t pid; /* 0 if exited */
356 int assignment_cnt; /* how many argv[i] are assignments? */
357 smallint is_stopped; /* is the command currently running? */
358 smallint grp_type; /* GRP_xxx */
359 struct pipe *group; /* if non-NULL, this "command" is { list },
360 * ( list ), or a compound statement */
362 char *group_as_string;
364 char **argv; /* command name and arguments */
365 struct redir_struct *redirects; /* I/O redirections */
367 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
368 * and on execution these are substituted with their values.
369 * Substitution can make _several_ words out of one argv[n]!
370 * Example: argv[0]=='.^C*^C.' here: echo .$*.
371 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
374 #define GRP_SUBSHELL 1
375 #if ENABLE_HUSH_FUNCTIONS
376 #define GRP_FUNCTION 2
381 int num_cmds; /* total number of commands in job */
382 int alive_cmds; /* number of commands running (not exited) */
383 int stopped_cmds; /* number of commands alive, but stopped */
385 int jobid; /* job number */
386 pid_t pgrp; /* process group ID for the job */
387 char *cmdtext; /* name of job */
389 struct command *cmds; /* array of commands in pipe */
390 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
391 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
392 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
394 typedef enum pipe_style {
401 /* This holds pointers to the various results of parsing */
402 struct parse_context {
403 /* linked list of pipes */
404 struct pipe *list_head;
405 /* last pipe (being constructed right now) */
407 /* last command in pipe (being constructed right now) */
408 struct command *command;
409 /* last redirect in command->redirects list */
410 struct redir_struct *pending_redirect;
416 smallint ctx_inverted; /* "! cmd | cmd" */
418 smallint ctx_dsemicolon; /* ";;" seen */
420 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
422 /* group we are enclosed in:
423 * example: "if pipe1; pipe2; then pipe3; fi"
424 * when we see "if" or "then", we malloc and copy current context,
425 * and make ->stack point to it. then we parse pipeN.
426 * when closing "then" / fi" / whatever is found,
427 * we move list_head into ->stack->command->group,
428 * copy ->stack into current context, and delete ->stack.
429 * (parsing of { list } and ( list ) doesn't use this method)
431 struct parse_context *stack;
435 /* On program start, environ points to initial environment.
436 * putenv adds new pointers into it, unsetenv removes them.
437 * Neither of these (de)allocates the strings.
438 * setenv allocates new strings in malloc space and does putenv,
439 * and thus setenv is unusable (leaky) for shell's purposes */
440 #define setenv(...) setenv_is_leaky_dont_use()
442 struct variable *next;
443 char *varstr; /* points to "name=" portion */
444 int max_len; /* if > 0, name is part of initial env; else name is malloced */
445 smallint flg_export; /* putenv should be done on this var */
446 smallint flg_read_only;
455 /* "Globals" within this file */
456 /* Sorted roughly by size (smaller offsets == smaller code) */
458 #if ENABLE_HUSH_INTERACTIVE
459 /* 'interactive_fd' is a fd# open to ctty, if we have one
460 * _AND_ if we decided to act interactively */
464 #define G_interactive_fd (G.interactive_fd)
466 #define G_interactive_fd 0
468 #if ENABLE_FEATURE_EDITING
469 line_input_t *line_input_state;
475 pid_t saved_tty_pgrp;
477 struct pipe *job_list;
478 struct pipe *toplevel_list;
479 //// smallint ctrl_z_flag;
481 smallint flag_SIGINT;
482 #if ENABLE_HUSH_LOOPS
483 smallint flag_break_continue;
486 smallint exiting; /* used to prevent EXIT trap recursion */
487 /* These four support $?, $#, and $1 */
488 smalluint last_exitcode;
489 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
490 smalluint global_args_malloced;
491 /* how many non-NULL argv's we have. NB: $# + 1 */
495 char *argv0_for_re_execing;
496 char **argv_from_re_execing;
498 #if ENABLE_HUSH_LOOPS
499 unsigned depth_break_continue;
500 unsigned depth_of_loop;
504 struct variable *top_var; /* = &G.shell_ver (set in main()) */
505 struct variable shell_ver;
506 /* Signal and trap handling */
507 // unsigned count_SIGCHLD;
508 // unsigned handled_SIGCHLD;
509 /* which signals have non-DFL handler (even with no traps set)? */
510 unsigned non_DFL_mask;
511 char **traps; /* char *traps[NSIG] */
512 sigset_t blocked_set;
513 sigset_t inherited_set;
515 unsigned long memleak_value;
517 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
518 #if ENABLE_FEATURE_SH_STANDALONE
519 struct nofork_save_area nofork_save;
522 sigjmp_buf toplevel_jb;
525 #define G (*ptr_to_globals)
526 /* Not #defining name to G.name - this quickly gets unwieldy
527 * (too many defines). Also, I actually prefer to see when a variable
528 * is global, thus "G." prefix is a useful hint */
529 #define INIT_G() do { \
530 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
534 /* Function prototypes for builtins */
535 static int builtin_cd(char **argv);
536 static int builtin_echo(char **argv);
537 static int builtin_eval(char **argv);
538 static int builtin_exec(char **argv);
539 static int builtin_exit(char **argv);
540 static int builtin_export(char **argv);
542 static int builtin_fg_bg(char **argv);
543 static int builtin_jobs(char **argv);
546 static int builtin_help(char **argv);
549 static int builtin_memleak(char **argv);
551 static int builtin_pwd(char **argv);
552 static int builtin_read(char **argv);
553 static int builtin_set(char **argv);
554 static int builtin_shift(char **argv);
555 static int builtin_source(char **argv);
556 static int builtin_test(char **argv);
557 static int builtin_trap(char **argv);
558 static int builtin_true(char **argv);
559 static int builtin_umask(char **argv);
560 static int builtin_unset(char **argv);
561 static int builtin_wait(char **argv);
562 #if ENABLE_HUSH_LOOPS
563 static int builtin_break(char **argv);
564 static int builtin_continue(char **argv);
567 /* Table of built-in functions. They can be forked or not, depending on
568 * context: within pipes, they fork. As simple commands, they do not.
569 * When used in non-forking context, they can change global variables
570 * in the parent shell process. If forked, of course they cannot.
571 * For example, 'unset foo | whatever' will parse and run, but foo will
572 * still be set at the end. */
573 struct built_in_command {
575 int (*function)(char **argv);
578 #define BLTIN(cmd, func, help) { cmd, func, help }
580 #define BLTIN(cmd, func, help) { cmd, func }
584 /* For now, echo and test are unconditionally enabled.
585 * Maybe make it configurable? */
586 static const struct built_in_command bltins[] = {
587 BLTIN("." , builtin_source , "Run commands in a file"),
588 BLTIN(":" , builtin_true , "No-op"),
589 BLTIN("[" , builtin_test , "Test condition"),
591 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
593 #if ENABLE_HUSH_LOOPS
594 BLTIN("break" , builtin_break , "Exit from a loop"),
596 BLTIN("cd" , builtin_cd , "Change directory"),
597 #if ENABLE_HUSH_LOOPS
598 BLTIN("continue", builtin_continue, "Start new loop iteration"),
600 BLTIN("echo" , builtin_echo , "Write to stdout"),
601 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
602 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
603 BLTIN("exit" , builtin_exit , "Exit"),
604 BLTIN("export" , builtin_export , "Set environment variable"),
606 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
609 BLTIN("help" , builtin_help , "List shell built-in commands"),
612 BLTIN("jobs" , builtin_jobs , "List active jobs"),
615 BLTIN("memleak" , builtin_memleak , "Debug tool"),
617 BLTIN("pwd" , builtin_pwd , "Print current directory"),
618 BLTIN("read" , builtin_read , "Input environment variable"),
619 // BLTIN("return" , builtin_return , "Return from a function"),
620 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
621 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
622 BLTIN("test" , builtin_test , "Test condition"),
623 BLTIN("trap" , builtin_trap , "Trap signals"),
624 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
625 BLTIN("umask" , builtin_umask , "Set file creation mask"),
626 BLTIN("unset" , builtin_unset , "Unset environment variable"),
627 BLTIN("wait" , builtin_wait , "Wait for process"),
631 /* Leak hunting. Use hush_leaktool.sh for post-processing.
634 static void *xxmalloc(int lineno, size_t size)
636 void *ptr = xmalloc((size + 0xff) & ~0xff);
637 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
640 static void *xxrealloc(int lineno, void *ptr, size_t size)
642 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
643 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
646 static char *xxstrdup(int lineno, const char *str)
648 char *ptr = xstrdup(str);
649 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
652 static void xxfree(void *ptr)
654 fdprintf(2, "free %p\n", ptr);
657 #define xmalloc(s) xxmalloc(__LINE__, s)
658 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
659 #define xstrdup(s) xxstrdup(__LINE__, s)
660 #define free(p) xxfree(p)
664 /* Syntax and runtime errors. They always abort scripts.
665 * In interactive use they usually discard unparsed and/or unexecuted commands
666 * and return to the prompt.
667 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
670 # define die_if_script(lineno, fmt...) die_if_script(fmt)
671 # define syntax_error(lineno, msg) syntax_error(msg)
672 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
673 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
674 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
677 static void die_if_script(unsigned lineno, const char *fmt, ...)
682 bb_error_msg("hush.c:%u", lineno);
685 bb_verror_msg(fmt, p, NULL);
687 if (!G_interactive_fd)
691 static void syntax_error(unsigned lineno, const char *msg)
694 die_if_script(lineno, "syntax error: %s", msg);
696 die_if_script(lineno, "syntax error", NULL);
699 static void syntax_error_at(unsigned lineno, const char *msg)
701 die_if_script(lineno, "syntax error at '%s'", msg);
704 static void syntax_error_unterm_ch(unsigned lineno, char ch)
709 die_if_script(lineno, "syntax error: unterminated %s", msg);
712 static void syntax_error_unterm_str(unsigned lineno, const char *s)
714 die_if_script(lineno, "syntax error: unterminated %s", s);
718 # undef die_if_script
720 # undef syntax_error_at
721 # undef syntax_error_unterm_ch
722 # undef syntax_error_unterm_str
724 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
725 # define syntax_error(msg) syntax_error(__LINE__, msg)
726 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
727 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
728 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
734 static int glob_needed(const char *s)
739 if (*s == '*' || *s == '[' || *s == '?')
746 static int is_well_formed_var_name(const char *s, char terminator)
748 if (!s || !(isalpha(*s) || *s == '_'))
751 while (isalnum(*s) || *s == '_')
753 return *s == terminator;
756 /* Replace each \x with x in place, return ptr past NUL. */
757 static char *unbackslash(char *src)
763 if ((*dst++ = *src++) == '\0')
769 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
790 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
791 v[count1 + count2] = NULL;
794 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
798 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
800 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
801 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
804 #define add_strings_to_strings(strings, add, need_to_dup) \
805 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
808 static char **add_string_to_strings(char **strings, char *add)
813 return add_strings_to_strings(strings, v, /*dup:*/ 0);
816 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
818 char **ptr = add_string_to_strings(strings, add);
819 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
822 #define add_string_to_strings(strings, add) \
823 xx_add_string_to_strings(__LINE__, strings, add)
826 static void putenv_all(char **strings)
831 debug_printf_env("putenv '%s'\n", *strings);
836 static char **putenv_all_and_save_old(char **strings)
846 eq = strchr(*strings, '=');
849 v = getenv(*strings);
852 /* v points to VAL in VAR=VAL, go back to VAR */
853 v -= (eq - *strings) + 1;
854 old = add_string_to_strings(old, v);
863 static void free_strings_and_unsetenv(char **strings, int unset)
873 debug_printf_env("unsetenv '%s'\n", *v);
881 static void free_strings(char **strings)
883 free_strings_and_unsetenv(strings, 0);
887 /* Basic theory of signal handling in shell
888 * ========================================
889 * This does not describe what hush does, rather, it is current understanding
890 * what it _should_ do. If it doesn't, it's a bug.
891 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
893 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
894 * is finished or backgrounded. It is the same in interactive and
895 * non-interactive shells, and is the same regardless of whether
896 * a user trap handler is installed or a shell special one is in effect.
897 * ^C or ^Z from keyboard seem to execute "at once" because it usually
898 * backgrounds (i.e. stops) or kills all members of currently running
901 * Wait builtin in interruptible by signals for which user trap is set
902 * or by SIGINT in interactive shell.
904 * Trap handlers will execute even within trap handlers. (right?)
906 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
908 * If job control is off, backgrounded commands ("cmd &")
909 * have SIGINT, SIGQUIT set to SIG_IGN.
911 * Commands run in command substitution ("`cmd`")
912 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
914 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
915 * by the shell from its parent.
917 * Siganls which differ from SIG_DFL action
918 * (note: child (i.e., [v]forked) shell is not an interactive shell):
921 * SIGTERM (interactive): ignore
922 * SIGHUP (interactive):
923 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
924 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
925 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
926 * that all pipe members are stopped) (right?)
927 * SIGINT (interactive): wait for last pipe, ignore the rest
928 * of the command line, show prompt. NB: ^C does not send SIGINT
929 * to interactive shell while shell is waiting for a pipe,
930 * since shell is bg'ed (is not in foreground process group).
931 * (check/expand this)
932 * Example 1: this waits 5 sec, but does not execute ls:
933 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
934 * Example 2: this does not wait and does not execute ls:
935 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
936 * Example 3: this does not wait 5 sec, but executes ls:
937 * "sleep 5; ls -l" + press ^C
939 * (What happens to signals which are IGN on shell start?)
940 * (What happens with signal mask on shell start?)
942 * Implementation in hush
943 * ======================
944 * We use in-kernel pending signal mask to determine which signals were sent.
945 * We block all signals which we don't want to take action immediately,
946 * i.e. we block all signals which need to have special handling as described
947 * above, and all signals which have traps set.
948 * After each pipe execution, we extract any pending signals via sigtimedwait()
951 * unsigned non_DFL_mask: a mask of such "special" signals
952 * sigset_t blocked_set: current blocked signal set
955 * clear bit in blocked_set unless it is also in non_DFL_mask
956 * "trap 'cmd' SIGxxx":
957 * set bit in blocked_set (even if 'cmd' is '')
958 * after [v]fork, if we plan to be a shell:
959 * nothing for {} child shell (say, "true | { true; true; } | true")
960 * unset all traps if () shell.
961 * after [v]fork, if we plan to exec:
962 * POSIX says pending signal mask is cleared in child - no need to clear it.
963 * Restore blocked signal set to one inherited by shell just prior to exec.
965 * Note: as a result, we do not use signal handlers much. The only uses
966 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
967 * and to restore tty pgrp on signal-induced exit.
970 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
972 // G.count_SIGCHLD++;
975 static int check_and_run_traps(int sig)
977 static const struct timespec zero_timespec = { 0, 0 };
978 smalluint save_rcode;
984 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
989 if (G.traps && G.traps[sig]) {
990 if (G.traps[sig][0]) {
991 /* We have user-defined handler */
992 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
993 save_rcode = G.last_exitcode;
996 G.last_exitcode = save_rcode;
997 } /* else: "" trap, ignoring signal */
1000 /* not a trap: special action */
1003 // G.count_SIGCHLD++;
1012 default: /* ignored: */
1013 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1022 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1023 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1024 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1025 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1027 /* Restores tty foreground process group, and exits.
1028 * May be called as signal handler for fatal signal
1029 * (will faithfully resend signal to itself, producing correct exit state)
1030 * or called directly with -EXITCODE.
1031 * We also call it if xfunc is exiting. */
1032 static void sigexit(int sig) NORETURN;
1033 static void sigexit(int sig)
1035 /* Disable all signals: job control, SIGPIPE, etc. */
1036 sigprocmask_allsigs(SIG_BLOCK);
1038 /* Careful: we can end up here after [v]fork. Do not restore
1039 * tty pgrp then, only top-level shell process does that */
1040 if (G_interactive_fd && getpid() == G.root_pid)
1041 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1043 /* Not a signal, just exit */
1047 kill_myself_with_sig(sig); /* does not return */
1051 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1052 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1056 /* Restores tty foreground process group, and exits. */
1057 static void hush_exit(int exitcode) NORETURN;
1058 static void hush_exit(int exitcode)
1060 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1061 /* Prevent recursion:
1062 * trap "echo Hi; exit" EXIT; exit
1064 char *argv[] = { NULL, G.traps[0], NULL };
1072 fflush(NULL); /* flush all streams */
1073 sigexit(- (exitcode & 0xff));
1080 static const char *set_cwd(void)
1082 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1083 * we must not try to free(bb_msg_unknown) */
1084 if (G.cwd == bb_msg_unknown)
1086 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1088 G.cwd = bb_msg_unknown;
1093 /* Get/check local shell variables */
1094 static struct variable *get_local_var(const char *name)
1096 struct variable *cur;
1102 for (cur = G.top_var; cur; cur = cur->next) {
1103 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1109 static const char *get_local_var_value(const char *src)
1111 struct variable *var = get_local_var(src);
1113 return strchr(var->varstr, '=') + 1;
1117 /* str holds "NAME=VAL" and is expected to be malloced.
1118 * We take ownership of it.
1122 * -1: if NAME is set, leave export status alone
1123 * if NAME is not set, do not export
1124 * flg_read_only is set only when we handle -R var=val
1127 #define set_local_var(str, flg_export, flg_read_only) \
1128 set_local_var(str, flg_export)
1130 static int set_local_var(char *str, int flg_export, int flg_read_only)
1132 struct variable *cur;
1136 value = strchr(str, '=');
1137 if (!value) { /* not expected to ever happen? */
1142 name_len = value - str + 1; /* including '=' */
1143 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1145 if (strncmp(cur->varstr, str, name_len) != 0) {
1147 /* Bail out. Note that now cur points
1148 * to last var in linked list */
1154 /* We found an existing var with this name */
1156 if (cur->flg_read_only) {
1160 bb_error_msg("%s: readonly variable", str);
1164 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1165 unsetenv(str); /* just in case */
1167 if (strcmp(cur->varstr, str) == 0) {
1172 if (cur->max_len >= strlen(str)) {
1173 /* This one is from startup env, reuse space */
1174 strcpy(cur->varstr, str);
1177 /* max_len == 0 signifies "malloced" var, which we can
1178 * (and has to) free */
1182 goto set_str_and_exp;
1185 /* Not found - create next variable struct */
1186 cur->next = xzalloc(sizeof(*cur));
1192 cur->flg_read_only = flg_read_only;
1195 if (flg_export == 1)
1196 cur->flg_export = 1;
1197 if (cur->flg_export) {
1198 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1199 return putenv(cur->varstr);
1204 static int unset_local_var(const char *name)
1206 struct variable *cur;
1207 struct variable *prev = prev; /* for gcc */
1211 return EXIT_SUCCESS;
1212 name_len = strlen(name);
1215 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1216 if (cur->flg_read_only) {
1217 bb_error_msg("%s: readonly variable", name);
1218 return EXIT_FAILURE;
1220 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1221 * is ro, and we cannot reach this code on the 1st pass */
1222 prev->next = cur->next;
1223 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1224 bb_unsetenv(cur->varstr);
1228 return EXIT_SUCCESS;
1233 return EXIT_SUCCESS;
1236 #if ENABLE_SH_MATH_SUPPORT
1237 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1238 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1239 static char *endofname(const char *name)
1247 if (!is_in_name(*p))
1253 static void arith_set_local_var(const char *name, const char *val, int flags)
1255 /* arith code doesnt malloc space, so do it for it */
1256 char *var = xasprintf("%s=%s", name, val);
1257 set_local_var(var, flags, 0);
1265 static int static_get(struct in_str *i)
1274 static int static_peek(struct in_str *i)
1279 #if ENABLE_HUSH_INTERACTIVE
1281 static void cmdedit_set_initial_prompt(void)
1283 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1284 G.PS1 = getenv("PS1");
1291 static const char* setup_prompt_string(int promptmode)
1293 const char *prompt_str;
1294 debug_printf("setup_prompt_string %d ", promptmode);
1295 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1296 /* Set up the prompt */
1297 if (promptmode == 0) { /* PS1 */
1299 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1304 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1305 debug_printf("result '%s'\n", prompt_str);
1309 static void get_user_input(struct in_str *i)
1312 const char *prompt_str;
1314 prompt_str = setup_prompt_string(i->promptmode);
1315 #if ENABLE_FEATURE_EDITING
1316 /* Enable command line editing only while a command line
1317 * is actually being read */
1320 /* buglet: SIGINT will not make new prompt to appear _at once_,
1321 * only after <Enter>. (^C will work) */
1322 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1323 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1324 check_and_run_traps(0);
1325 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1326 i->eof_flag = (r < 0);
1327 if (i->eof_flag) { /* EOF/error detected */
1328 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1329 G.user_input_buf[1] = '\0';
1334 fputs(prompt_str, stdout);
1336 G.user_input_buf[0] = r = fgetc(i->file);
1337 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1338 //do we need check_and_run_traps(0)? (maybe only if stdin)
1339 } while (G.flag_SIGINT);
1340 i->eof_flag = (r == EOF);
1342 i->p = G.user_input_buf;
1345 #endif /* INTERACTIVE */
1347 /* This is the magic location that prints prompts
1348 * and gets data back from the user */
1349 static int file_get(struct in_str *i)
1353 /* If there is data waiting, eat it up */
1354 if (i->p && *i->p) {
1355 #if ENABLE_HUSH_INTERACTIVE
1359 if (i->eof_flag && !*i->p)
1361 /* note: ch is never NUL */
1363 /* need to double check i->file because we might be doing something
1364 * more complicated by now, like sourcing or substituting. */
1365 #if ENABLE_HUSH_INTERACTIVE
1366 if (G_interactive_fd && i->promptme && i->file == stdin) {
1369 } while (!*i->p); /* need non-empty line */
1370 i->promptmode = 1; /* PS2 */
1375 do ch = fgetc(i->file); while (ch == '\0');
1377 debug_printf("file_get: got '%c' %d\n", ch, ch);
1378 #if ENABLE_HUSH_INTERACTIVE
1385 /* All callers guarantee this routine will never
1386 * be used right after a newline, so prompting is not needed.
1388 static int file_peek(struct in_str *i)
1391 if (i->p && *i->p) {
1392 if (i->eof_flag && !i->p[1])
1395 /* note: ch is never NUL */
1397 do ch = fgetc(i->file); while (ch == '\0');
1398 i->eof_flag = (ch == EOF);
1399 i->peek_buf[0] = ch;
1400 i->peek_buf[1] = '\0';
1402 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1406 static void setup_file_in_str(struct in_str *i, FILE *f)
1408 i->peek = file_peek;
1410 #if ENABLE_HUSH_INTERACTIVE
1412 i->promptmode = 0; /* PS1 */
1418 static void setup_string_in_str(struct in_str *i, const char *s)
1420 i->peek = static_peek;
1421 i->get = static_get;
1422 #if ENABLE_HUSH_INTERACTIVE
1424 i->promptmode = 0; /* PS1 */
1434 #define B_CHUNK (32 * sizeof(char*))
1436 static void o_reset(o_string *o)
1444 static void o_free(o_string *o)
1447 memset(o, 0, sizeof(*o));
1450 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1455 static void o_grow_by(o_string *o, int len)
1457 if (o->length + len > o->maxlen) {
1458 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1459 o->data = xrealloc(o->data, 1 + o->maxlen);
1463 static void o_addchr(o_string *o, int ch)
1465 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1467 o->data[o->length] = ch;
1469 o->data[o->length] = '\0';
1472 static void o_addblock(o_string *o, const char *str, int len)
1475 memcpy(&o->data[o->length], str, len);
1477 o->data[o->length] = '\0';
1481 static void o_addstr(o_string *o, const char *str)
1483 o_addblock(o, str, strlen(str));
1485 static void nommu_addchr(o_string *o, int ch)
1491 #define nommu_addchr(o, str) ((void)0)
1494 static void o_addstr_with_NUL(o_string *o, const char *str)
1496 o_addblock(o, str, strlen(str) + 1);
1499 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1504 && (*str != '*' && *str != '?' && *str != '[')
1512 /* My analysis of quoting semantics tells me that state information
1513 * is associated with a destination, not a source.
1515 static void o_addqchr(o_string *o, int ch)
1518 char *found = strchr("*?[\\", ch);
1523 o->data[o->length] = '\\';
1526 o->data[o->length] = ch;
1528 o->data[o->length] = '\0';
1531 static void o_addQchr(o_string *o, int ch)
1534 if (o->o_escape && strchr("*?[\\", ch)) {
1536 o->data[o->length] = '\\';
1540 o->data[o->length] = ch;
1542 o->data[o->length] = '\0';
1545 static void o_addQstr(o_string *o, const char *str, int len)
1548 o_addblock(o, str, len);
1554 int ordinary_cnt = strcspn(str, "*?[\\");
1555 if (ordinary_cnt > len) /* paranoia */
1557 o_addblock(o, str, ordinary_cnt);
1558 if (ordinary_cnt == len)
1560 str += ordinary_cnt;
1561 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1565 if (ch) { /* it is necessarily one of "*?[\\" */
1567 o->data[o->length] = '\\';
1571 o->data[o->length] = ch;
1573 o->data[o->length] = '\0';
1577 /* A special kind of o_string for $VAR and `cmd` expansion.
1578 * It contains char* list[] at the beginning, which is grown in 16 element
1579 * increments. Actual string data starts at the next multiple of 16 * (char*).
1580 * list[i] contains an INDEX (int!) into this string data.
1581 * It means that if list[] needs to grow, data needs to be moved higher up
1582 * but list[i]'s need not be modified.
1583 * NB: remembering how many list[i]'s you have there is crucial.
1584 * o_finalize_list() operation post-processes this structure - calculates
1585 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1587 #if DEBUG_EXPAND || DEBUG_GLOB
1588 static void debug_print_list(const char *prefix, o_string *o, int n)
1590 char **list = (char**)o->data;
1591 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1593 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1594 prefix, list, n, string_start, o->length, o->maxlen);
1596 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1597 o->data + (int)list[i] + string_start,
1598 o->data + (int)list[i] + string_start);
1602 const char *p = o->data + (int)list[n - 1] + string_start;
1603 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1607 #define debug_print_list(prefix, o, n) ((void)0)
1610 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1611 * in list[n] so that it points past last stored byte so far.
1612 * It returns n+1. */
1613 static int o_save_ptr_helper(o_string *o, int n)
1615 char **list = (char**)o->data;
1619 if (!o->has_empty_slot) {
1620 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1621 string_len = o->length - string_start;
1622 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1623 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1624 /* list[n] points to string_start, make space for 16 more pointers */
1625 o->maxlen += 0x10 * sizeof(list[0]);
1626 o->data = xrealloc(o->data, o->maxlen + 1);
1627 list = (char**)o->data;
1628 memmove(list + n + 0x10, list + n, string_len);
1629 o->length += 0x10 * sizeof(list[0]);
1631 debug_printf_list("list[%d]=%d string_start=%d\n",
1632 n, string_len, string_start);
1635 /* We have empty slot at list[n], reuse without growth */
1636 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1637 string_len = o->length - string_start;
1638 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1639 n, string_len, string_start);
1640 o->has_empty_slot = 0;
1642 list[n] = (char*)(ptrdiff_t)string_len;
1646 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1647 static int o_get_last_ptr(o_string *o, int n)
1649 char **list = (char**)o->data;
1650 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1652 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1655 /* o_glob performs globbing on last list[], saving each result
1656 * as a new list[]. */
1657 static int o_glob(o_string *o, int n)
1663 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1665 return o_save_ptr_helper(o, n);
1666 pattern = o->data + o_get_last_ptr(o, n);
1667 debug_printf_glob("glob pattern '%s'\n", pattern);
1668 if (!glob_needed(pattern)) {
1670 o->length = unbackslash(pattern) - o->data;
1671 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1672 return o_save_ptr_helper(o, n);
1675 memset(&globdata, 0, sizeof(globdata));
1676 gr = glob(pattern, 0, NULL, &globdata);
1677 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1678 if (gr == GLOB_NOSPACE)
1679 bb_error_msg_and_die("out of memory during glob");
1680 if (gr == GLOB_NOMATCH) {
1681 globfree(&globdata);
1684 if (gr != 0) { /* GLOB_ABORTED ? */
1685 //TODO: testcase for bad glob pattern behavior
1686 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1688 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1689 char **argv = globdata.gl_pathv;
1690 o->length = pattern - o->data; /* "forget" pattern */
1692 o_addstr_with_NUL(o, *argv);
1693 n = o_save_ptr_helper(o, n);
1699 globfree(&globdata);
1701 debug_print_list("o_glob returning", o, n);
1705 /* If o->o_glob == 1, glob the string so far remembered.
1706 * Otherwise, just finish current list[] and start new */
1707 static int o_save_ptr(o_string *o, int n)
1709 if (o->o_glob) { /* if globbing is requested */
1710 /* If o->has_empty_slot, list[n] was already globbed
1711 * (if it was requested back then when it was filled)
1712 * so don't do that again! */
1713 if (!o->has_empty_slot)
1714 return o_glob(o, n); /* o_save_ptr_helper is inside */
1716 return o_save_ptr_helper(o, n);
1719 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1720 static char **o_finalize_list(o_string *o, int n)
1725 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1727 debug_print_list("finalized", o, n);
1728 debug_printf_expand("finalized n:%d\n", n);
1729 list = (char**)o->data;
1730 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1734 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1740 /* Expansion can recurse */
1741 #if ENABLE_HUSH_TICK
1742 static int process_command_subs(o_string *dest, const char *s);
1744 static char *expand_string_to_string(const char *str);
1746 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1747 parse_stream_dquoted(dest, input, dquote_end)
1749 static int parse_stream_dquoted(o_string *as_string,
1751 struct in_str *input,
1754 /* expand_strvec_to_strvec() takes a list of strings, expands
1755 * all variable references within and returns a pointer to
1756 * a list of expanded strings, possibly with larger number
1757 * of strings. (Think VAR="a b"; echo $VAR).
1758 * This new list is allocated as a single malloc block.
1759 * NULL-terminated list of char* pointers is at the beginning of it,
1760 * followed by strings themself.
1761 * Caller can deallocate entire list by single free(list). */
1763 /* Store given string, finalizing the word and starting new one whenever
1764 * we encounter IFS char(s). This is used for expanding variable values.
1765 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1766 static int expand_on_ifs(o_string *output, int n, const char *str)
1769 int word_len = strcspn(str, G.ifs);
1771 if (output->o_escape || !output->o_glob)
1772 o_addQstr(output, str, word_len);
1773 else /* protect backslashes against globbing up :) */
1774 o_addblock_duplicate_backslash(output, str, word_len);
1777 if (!*str) /* EOL - do not finalize word */
1779 o_addchr(output, '\0');
1780 debug_print_list("expand_on_ifs", output, n);
1781 n = o_save_ptr(output, n);
1782 str += strspn(str, G.ifs); /* skip ifs chars */
1784 debug_print_list("expand_on_ifs[1]", output, n);
1788 /* Helper to expand $((...)) and heredoc body. These act as if
1789 * they are in double quotes, with the exception that they are not :).
1790 * Just the rules are similar: "expand only $var and `cmd`"
1792 * Returns malloced string.
1793 * As an optimization, we return NULL if expansion is not needed.
1795 static char *expand_pseudo_dquoted(const char *str)
1798 struct in_str input;
1799 o_string dest = NULL_O_STRING;
1801 if (strchr(str, '$') == NULL
1802 #if ENABLE_HUSH_TICK
1803 && strchr(str, '`') == NULL
1809 /* We need to expand. Example:
1810 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1812 setup_string_in_str(&input, str);
1813 parse_stream_dquoted(NULL, &dest, &input, EOF);
1814 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1815 exp_str = expand_string_to_string(dest.data);
1816 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1817 o_free_unsafe(&dest);
1821 /* Expand all variable references in given string, adding words to list[]
1822 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1823 * to be filled). This routine is extremely tricky: has to deal with
1824 * variables/parameters with whitespace, $* and $@, and constructs like
1825 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1826 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1828 /* or_mask is either 0 (normal case) or 0x80
1829 * (expansion of right-hand side of assignment == 1-element expand.
1830 * It will also do no globbing, and thus we must not backslash-quote!) */
1832 char first_ch, ored_ch;
1840 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1841 debug_print_list("expand_vars_to_list", output, n);
1842 n = o_save_ptr(output, n);
1843 debug_print_list("expand_vars_to_list[0]", output, n);
1845 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1846 #if ENABLE_HUSH_TICK
1847 o_string subst_result = NULL_O_STRING;
1849 #if ENABLE_SH_MATH_SUPPORT
1850 char arith_buf[sizeof(arith_t)*3 + 2];
1852 o_addblock(output, arg, p - arg);
1853 debug_print_list("expand_vars_to_list[1]", output, n);
1855 p = strchr(p, SPECIAL_VAR_SYMBOL);
1857 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1858 /* "$@" is special. Even if quoted, it can still
1859 * expand to nothing (not even an empty string) */
1860 if ((first_ch & 0x7f) != '@')
1861 ored_ch |= first_ch;
1864 switch (first_ch & 0x7f) {
1865 /* Highest bit in first_ch indicates that var is double-quoted */
1867 val = utoa(G.root_pid);
1869 case '!': /* bg pid */
1870 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1872 case '?': /* exitcode */
1873 val = utoa(G.last_exitcode);
1875 case '#': /* argc */
1876 if (arg[1] != SPECIAL_VAR_SYMBOL)
1877 /* actually, it's a ${#var} */
1879 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1884 if (!G.global_argv[i])
1886 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1887 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1888 smallint sv = output->o_escape;
1889 /* unquoted var's contents should be globbed, so don't escape */
1890 output->o_escape = 0;
1891 while (G.global_argv[i]) {
1892 n = expand_on_ifs(output, n, G.global_argv[i]);
1893 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1894 if (G.global_argv[i++][0] && G.global_argv[i]) {
1895 /* this argv[] is not empty and not last:
1896 * put terminating NUL, start new word */
1897 o_addchr(output, '\0');
1898 debug_print_list("expand_vars_to_list[2]", output, n);
1899 n = o_save_ptr(output, n);
1900 debug_print_list("expand_vars_to_list[3]", output, n);
1903 output->o_escape = sv;
1905 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1906 * and in this case should treat it like '$*' - see 'else...' below */
1907 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1909 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1910 if (++i >= G.global_argc)
1912 o_addchr(output, '\0');
1913 debug_print_list("expand_vars_to_list[4]", output, n);
1914 n = o_save_ptr(output, n);
1916 } else { /* quoted $*: add as one word */
1918 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1919 if (!G.global_argv[++i])
1922 o_addchr(output, G.ifs[0]);
1926 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1927 /* "Empty variable", used to make "" etc to not disappear */
1931 #if ENABLE_HUSH_TICK
1932 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1935 //TODO: can we just stuff it into "output" directly?
1936 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1937 process_command_subs(&subst_result, arg);
1938 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1939 val = subst_result.data;
1942 #if ENABLE_SH_MATH_SUPPORT
1943 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1944 arith_eval_hooks_t hooks;
1949 arg++; /* skip '+' */
1950 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1951 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1953 exp_str = expand_pseudo_dquoted(arg);
1954 hooks.lookupvar = get_local_var_value;
1955 hooks.setvar = arith_set_local_var;
1956 hooks.endofname = endofname;
1957 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1961 const char *msg = "error in arithmetic";
1964 msg = "exponent less than 0";
1967 msg = "divide by 0";
1970 msg = "expression recursion loop detected";
1975 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1976 sprintf(arith_buf, arith_t_fmt, res);
1981 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1983 bool exp_len = false;
1984 bool exp_null = false;
1986 char exp_save = exp_save; /* for compiler */
1987 char exp_op = exp_op; /* for compiler */
1988 char *exp_word = exp_word; /* for compiler */
1992 arg[0] = first_ch & 0x7f;
1994 /* prepare for expansions */
1995 if (var[0] == '#') {
1996 /* handle length expansion ${#var} */
2000 /* maybe handle parameter expansion */
2001 exp_off = strcspn(var, ":-=+?%#");
2005 exp_save = var[exp_off];
2006 exp_null = exp_save == ':';
2007 exp_word = var + exp_off;
2010 exp_op = *exp_word++;
2011 var[exp_off] = '\0';
2015 /* lookup the variable in question */
2016 if (isdigit(var[0])) {
2017 /* handle_dollar() should have vetted var for us */
2019 if (i < G.global_argc)
2020 val = G.global_argv[i];
2021 /* else val remains NULL: $N with too big N */
2023 val = get_local_var_value(var);
2025 /* handle any expansions */
2027 debug_printf_expand("expand: length of '%s' = ", val);
2028 val = utoa(val ? strlen(val) : 0);
2029 debug_printf_expand("%s\n", val);
2030 } else if (exp_off) {
2031 if (exp_op == '%' || exp_op == '#') {
2033 /* we need to do a pattern match */
2036 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2037 if (exp_op == *exp_word) /* ## or %% */
2039 val = dyn_val = xstrdup(val);
2040 loc = scan(dyn_val, exp_word, zero);
2047 /* we need to do an expansion */
2048 int exp_test = (!val || (exp_null && !val[0]));
2050 exp_test = !exp_test;
2051 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2052 exp_null ? "true" : "false", exp_test);
2054 if (exp_op == '?') {
2055 //TODO: how interactive bash aborts expansion mid-command?
2056 /* ${var?[error_msg_if_unset]} */
2057 /* ${var:?[error_msg_if_unset_or_null]} */
2058 /* mimic bash message */
2059 die_if_script("%s: %s",
2061 exp_word[0] ? exp_word : "parameter null or not set"
2067 if (exp_op == '=') {
2068 /* ${var=[word]} or ${var:=[word]} */
2069 if (isdigit(var[0]) || var[0] == '#') {
2070 /* mimic bash message */
2071 die_if_script("$%s: cannot assign in this way", var);
2074 char *new_var = xasprintf("%s=%s", var, val);
2075 set_local_var(new_var, -1, 0);
2081 var[exp_off] = exp_save;
2085 #if ENABLE_HUSH_TICK
2088 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2089 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2091 /* unquoted var's contents should be globbed, so don't escape */
2092 smallint sv = output->o_escape;
2093 output->o_escape = 0;
2094 n = expand_on_ifs(output, n, val);
2096 output->o_escape = sv;
2098 } else { /* quoted $VAR, val will be appended below */
2099 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2102 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2104 o_addQstr(output, val, strlen(val));
2108 /* Do the check to avoid writing to a const string */
2109 if (*p != SPECIAL_VAR_SYMBOL)
2110 *p = SPECIAL_VAR_SYMBOL;
2112 #if ENABLE_HUSH_TICK
2113 o_free(&subst_result);
2116 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2119 debug_print_list("expand_vars_to_list[a]", output, n);
2120 /* this part is literal, and it was already pre-quoted
2121 * if needed (much earlier), do not use o_addQstr here! */
2122 o_addstr_with_NUL(output, arg);
2123 debug_print_list("expand_vars_to_list[b]", output, n);
2124 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2125 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2128 /* allow to reuse list[n] later without re-growth */
2129 output->has_empty_slot = 1;
2131 o_addchr(output, '\0');
2136 static char **expand_variables(char **argv, int or_mask)
2141 o_string output = NULL_O_STRING;
2143 if (or_mask & 0x100) {
2144 output.o_escape = 1; /* protect against globbing for "$var" */
2145 /* (unquoted $var will temporarily switch it off) */
2152 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2155 debug_print_list("expand_variables", &output, n);
2157 /* output.data (malloced in one block) gets returned in "list" */
2158 list = o_finalize_list(&output, n);
2159 debug_print_strings("expand_variables[1]", list);
2163 static char **expand_strvec_to_strvec(char **argv)
2165 return expand_variables(argv, 0x100);
2168 /* Used for expansion of right hand of assignments */
2169 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2171 static char *expand_string_to_string(const char *str)
2173 char *argv[2], **list;
2175 argv[0] = (char*)str;
2177 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2179 if (!list[0] || list[1])
2180 bb_error_msg_and_die("BUG in varexp2");
2181 /* actually, just move string 2*sizeof(char*) bytes back */
2182 overlapping_strcpy((char*)list, list[0]);
2183 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2187 /* Used for "eval" builtin */
2188 static char* expand_strvec_to_string(char **argv)
2192 list = expand_variables(argv, 0x80);
2193 /* Convert all NULs to spaces */
2198 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2199 bb_error_msg_and_die("BUG in varexp3");
2200 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2204 overlapping_strcpy((char*)list, list[0]);
2205 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2209 static char **expand_assignments(char **argv, int count)
2213 /* Expand assignments into one string each */
2214 for (i = 0; i < count; i++) {
2215 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2222 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2223 #define clean_up_after_re_execute() ((void)0)
2224 static void reset_traps_to_defaults(void)
2232 for (sig = 0; sig < NSIG; sig++) {
2236 G.traps[sig] = NULL;
2237 /* There is no signal for 0 (EXIT) */
2240 /* there was a trap handler, we are removing it
2241 * (if sig has non-DFL handling,
2242 * we don't need to do anything) */
2243 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2245 sigdelset(&G.blocked_set, sig);
2249 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2254 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2255 static void re_execute_shell(const char *s, int is_heredoc)
2257 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2258 char *heredoc_argv[4];
2259 struct variable *cur;
2260 char **argv, **pp, **pp2;
2264 argv = heredoc_argv;
2265 argv[0] = (char *) G.argv0_for_re_execing;
2266 argv[1] = (char *) "-<";
2267 argv[2] = (char *) s;
2269 pp = &argv[3]; /* used as pointer to empty environment */
2273 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2274 , (unsigned) G.root_pid
2275 , (unsigned) G.last_bg_pid
2276 , (unsigned) G.last_exitcode
2277 USE_HUSH_LOOPS(, G.depth_of_loop)
2279 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2280 * 3:-c 4:<cmd> <argN...> 5:NULL
2282 cnt = 5 + G.global_argc;
2283 for (cur = G.top_var; cur; cur = cur->next) {
2284 if (!cur->flg_export || cur->flg_read_only)
2287 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2288 *pp++ = (char *) G.argv0_for_re_execing;
2290 for (cur = G.top_var; cur; cur = cur->next) {
2291 if (cur->varstr == hush_version_str)
2293 if (cur->flg_read_only) {
2294 *pp++ = (char *) "-R";
2295 *pp++ = cur->varstr;
2296 } else if (!cur->flg_export) {
2297 *pp++ = (char *) "-V";
2298 *pp++ = cur->varstr;
2301 //TODO: pass functions
2302 /* We can pass activated traps here. Say, -Tnn:trap_string
2304 * However, POSIX says that subshells reset signals with traps
2306 * I tested bash-3.2 and it not only does that with true subshells
2307 * of the form ( list ), but with any forked children shells.
2308 * I set trap "echo W" WINCH; and then tried:
2310 * { echo 1; sleep 20; echo 2; } &
2311 * while true; do echo 1; sleep 20; echo 2; break; done &
2312 * true | { echo 1; sleep 20; echo 2; } | cat
2314 * In all these cases sending SIGWINCH to the child shell
2315 * did not run the trap. If I add trap "echo V" WINCH;
2316 * _inside_ group (just before echo 1), it works.
2318 * I conclude it means we don't need to pass active traps here.
2319 * exec syscall below resets them to SIG_DFL for us.
2321 *pp++ = (char *) "-c";
2323 pp2 = G.global_argv;
2326 /* *pp = NULL; - is already there */
2330 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2331 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2332 execve(bb_busybox_exec_path, argv, pp);
2333 /* Fallback. Useful for init=/bin/hush usage etc */
2334 if (argv[0][0] == '/')
2335 execve(argv[0], argv, pp);
2336 xfunc_error_retval = 127;
2337 bb_error_msg_and_die("can't re-execute the shell");
2340 static void clean_up_after_re_execute(void)
2342 char **pp = G.argv_from_re_execing;
2344 /* Must match re_execute_shell's allocations (if any) */
2346 G.argv_from_re_execing = NULL;
2349 #endif /* !BB_MMU */
2352 static void setup_heredoc(struct redir_struct *redir)
2354 struct fd_pair pair;
2357 /* the _body_ of heredoc (misleading field name) */
2358 const char *heredoc = redir->rd_filename;
2362 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2363 expanded = expand_pseudo_dquoted(heredoc);
2367 len = strlen(heredoc);
2369 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2371 xmove_fd(pair.rd, redir->rd_fd);
2373 /* Try writing without forking. Newer kernels have
2374 * dynamically growing pipes. Must use non-blocking write! */
2377 written = write(pair.wr, heredoc, len);
2388 ndelay_off(pair.wr);
2390 /* Okay, pipe buffer was not big enough */
2391 /* Note: we must not create a stray child (bastard? :)
2392 * for the unsuspecting parent process. Child creates a grandchild
2393 * and exits before parent execs the process which consumes heredoc
2394 * (that exec happens after we return from this function) */
2397 bb_perror_msg_and_die("vfork");
2400 pid = BB_MMU ? fork() : vfork();
2402 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2406 close(redir->rd_fd); /* read side of the pipe */
2408 full_write(pair.wr, heredoc, len); /* may loop or block */
2411 /* Delegate blocking writes to another process */
2412 disable_restore_tty_pgrp_on_exit();
2413 xmove_fd(pair.wr, STDOUT_FILENO);
2414 re_execute_shell(heredoc, 1);
2418 enable_restore_tty_pgrp_on_exit();
2419 clean_up_after_re_execute();
2422 wait(NULL); /* wait till child has died */
2425 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2426 * and stderr if they are redirected. */
2427 static int setup_redirects(struct command *prog, int squirrel[])
2430 struct redir_struct *redir;
2432 for (redir = prog->redirects; redir; redir = redir->next) {
2433 if (redir->rd_type == REDIRECT_HEREDOC2) {
2434 /* rd_fd<<HERE case */
2435 if (squirrel && redir->rd_fd < 3) {
2436 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2438 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2440 debug_printf_parse("set heredoc '%s'\n",
2441 redir->rd_filename);
2442 setup_heredoc(redir);
2446 if (redir->rd_dup == REDIRFD_TO_FILE) {
2447 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2449 if (redir->rd_filename == NULL) {
2450 /* Something went wrong in the parse.
2451 * Pretend it didn't happen */
2452 bb_error_msg("bug in redirect parse");
2455 mode = redir_table[redir->rd_type].mode;
2456 p = expand_string_to_string(redir->rd_filename);
2457 openfd = open_or_warn(p, mode);
2460 /* this could get lost if stderr has been redirected, but
2461 * bash and ash both lose it as well (though zsh doesn't!) */
2462 //what the above comment tries to say?
2466 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2467 openfd = redir->rd_dup;
2470 if (openfd != redir->rd_fd) {
2471 if (squirrel && redir->rd_fd < 3) {
2472 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2474 if (openfd == REDIRFD_CLOSE) {
2475 /* "n>-" means "close me" */
2476 close(redir->rd_fd);
2478 xdup2(openfd, redir->rd_fd);
2479 if (redir->rd_dup == REDIRFD_TO_FILE)
2487 static void restore_redirects(int squirrel[])
2490 for (i = 0; i < 3; i++) {
2493 /* We simply die on error */
2501 #define free_pipe_list(head, indent) free_pipe_list(head)
2502 #define free_pipe(pi, indent) free_pipe(pi)
2504 static void free_pipe_list(struct pipe *head, int indent);
2506 /* Return code is the exit status of the pipe */
2507 static void free_pipe(struct pipe *pi, int indent)
2510 struct command *command;
2511 struct redir_struct *r, *rnext;
2514 if (pi->stopped_cmds > 0) /* why? */
2516 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2517 for (i = 0; i < pi->num_cmds; i++) {
2518 command = &pi->cmds[i];
2519 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2520 if (command->argv) {
2521 for (a = 0, p = command->argv; *p; a++, p++) {
2522 debug_printf_clean("%s argv[%d] = %s\n",
2523 indenter(indent), a, *p);
2525 free_strings(command->argv);
2526 command->argv = NULL;
2528 /* not "else if": on syntax error, we may have both! */
2529 if (command->group) {
2530 debug_printf_clean("%s begin group (grp_type:%d)\n",
2531 indenter(indent), command->grp_type);
2532 free_pipe_list(command->group, indent+3);
2533 debug_printf_clean("%s end group\n", indenter(indent));
2534 command->group = NULL;
2537 free(command->group_as_string);
2538 command->group_as_string = NULL;
2540 for (r = command->redirects; r; r = rnext) {
2541 debug_printf_clean("%s redirect %d%s", indenter(indent),
2542 r->fd, redir_table[r->rd_type].descrip);
2543 /* guard against the case >$FOO, where foo is unset or blank */
2544 if (r->rd_filename) {
2545 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2546 free(r->rd_filename);
2547 r->rd_filename = NULL;
2549 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2553 command->redirects = NULL;
2555 free(pi->cmds); /* children are an array, they get freed all at once */
2563 static void free_pipe_list(struct pipe *head, int indent)
2565 struct pipe *pi, *next;
2567 for (pi = head; pi; pi = next) {
2569 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2571 free_pipe(pi, indent);
2572 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2574 /*pi->next = NULL;*/
2581 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2582 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2583 #define pseudo_exec(nommu_save, command, argv_expanded) \
2584 pseudo_exec(command, argv_expanded)
2587 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2589 * XXX no exit() here. If you don't exec, use _exit instead.
2590 * The at_exit handlers apparently confuse the calling process,
2591 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2592 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2593 char **argv, int assignment_cnt,
2594 char **argv_expanded) NORETURN;
2595 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2596 char **argv, int assignment_cnt,
2597 char **argv_expanded)
2601 /* Case when we are here: ... | var=val | ... */
2602 if (!argv[assignment_cnt])
2603 _exit(EXIT_SUCCESS);
2605 new_env = expand_assignments(argv, assignment_cnt);
2607 putenv_all(new_env);
2608 free(new_env); /* optional */
2610 nommu_save->new_env = new_env;
2611 nommu_save->old_env = putenv_all_and_save_old(new_env);
2613 if (argv_expanded) {
2614 argv = argv_expanded;
2616 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2618 nommu_save->argv = argv;
2622 /* On NOMMU, we must never block!
2623 * Example: { sleep 99999 | read line } & echo Ok
2624 * read builtin will block on read syscall, leaving parent blocked
2625 * in vfork. Therefore we can't do this:
2628 /* Check if the command matches any of the builtins.
2629 * Depending on context, this might be redundant. But it's
2630 * easier to waste a few CPU cycles than it is to figure out
2631 * if this is one of those cases.
2635 const struct built_in_command *x;
2636 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2637 if (strcmp(argv[0], x->cmd) == 0) {
2638 debug_printf_exec("running builtin '%s'\n",
2640 rcode = x->function(argv);
2648 #if ENABLE_FEATURE_SH_STANDALONE
2649 /* Check if the command matches any busybox applets */
2650 if (strchr(argv[0], '/') == NULL) {
2651 int a = find_applet_by_name(argv[0]);
2653 #if BB_MMU /* see above why on NOMMU it is not allowed */
2654 if (APPLET_IS_NOEXEC(a)) {
2655 debug_printf_exec("running applet '%s'\n", argv[0]);
2656 run_applet_no_and_exit(a, argv);
2659 /* Re-exec ourselves */
2660 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2661 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2662 execv(bb_busybox_exec_path, argv);
2663 /* If they called chroot or otherwise made the binary no longer
2664 * executable, fall through */
2669 debug_printf_exec("execing '%s'\n", argv[0]);
2670 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2671 execvp(argv[0], argv);
2672 bb_perror_msg("can't exec '%s'", argv[0]);
2673 _exit(EXIT_FAILURE);
2676 static int run_list(struct pipe *pi);
2678 /* Called after [v]fork() in run_pipe
2680 static void pseudo_exec(nommu_save_t *nommu_save,
2681 struct command *command,
2682 char **argv_expanded) NORETURN;
2683 static void pseudo_exec(nommu_save_t *nommu_save,
2684 struct command *command,
2685 char **argv_expanded)
2687 if (command->argv) {
2688 pseudo_exec_argv(nommu_save, command->argv,
2689 command->assignment_cnt, argv_expanded);
2692 if (command->group) {
2693 /* Cases when we are here:
2696 * ... | ( list ) | ...
2697 * ... | { list } | ...
2701 debug_printf_exec("pseudo_exec: run_list\n");
2702 reset_traps_to_defaults();
2703 rcode = run_list(command->group);
2704 /* OK to leak memory by not calling free_pipe_list,
2705 * since this process is about to exit */
2708 re_execute_shell(command->group_as_string, 0);
2712 /* Case when we are here: ... | >file */
2713 debug_printf_exec("pseudo_exec'ed null command\n");
2714 _exit(EXIT_SUCCESS);
2718 static const char *get_cmdtext(struct pipe *pi)
2724 /* This is subtle. ->cmdtext is created only on first backgrounding.
2725 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2726 * On subsequent bg argv is trashed, but we won't use it */
2729 argv = pi->cmds[0].argv;
2730 if (!argv || !argv[0]) {
2731 pi->cmdtext = xzalloc(1);
2736 do len += strlen(*argv) + 1; while (*++argv);
2737 pi->cmdtext = p = xmalloc(len);
2738 argv = pi->cmds[0].argv;
2740 len = strlen(*argv);
2741 memcpy(p, *argv, len);
2749 static void insert_bg_job(struct pipe *pi)
2751 struct pipe *thejob;
2754 /* Linear search for the ID of the job to use */
2756 for (thejob = G.job_list; thejob; thejob = thejob->next)
2757 if (thejob->jobid >= pi->jobid)
2758 pi->jobid = thejob->jobid + 1;
2760 /* Add thejob to the list of running jobs */
2762 thejob = G.job_list = xmalloc(sizeof(*thejob));
2764 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2766 thejob->next = xmalloc(sizeof(*thejob));
2767 thejob = thejob->next;
2770 /* Physically copy the struct job */
2771 memcpy(thejob, pi, sizeof(struct pipe));
2772 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2773 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2774 for (i = 0; i < pi->num_cmds; i++) {
2775 // TODO: do we really need to have so many fields which are just dead weight
2776 // at execution stage?
2777 thejob->cmds[i].pid = pi->cmds[i].pid;
2778 /* all other fields are not used and stay zero */
2780 thejob->next = NULL;
2781 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2783 /* We don't wait for background thejobs to return -- append it
2784 to the list of backgrounded thejobs and leave it alone */
2785 if (G_interactive_fd)
2786 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2787 G.last_bg_pid = thejob->cmds[0].pid;
2788 G.last_jobid = thejob->jobid;
2791 static void remove_bg_job(struct pipe *pi)
2793 struct pipe *prev_pipe;
2795 if (pi == G.job_list) {
2796 G.job_list = pi->next;
2798 prev_pipe = G.job_list;
2799 while (prev_pipe->next != pi)
2800 prev_pipe = prev_pipe->next;
2801 prev_pipe->next = pi->next;
2804 G.last_jobid = G.job_list->jobid;
2809 /* Remove a backgrounded job */
2810 static void delete_finished_bg_job(struct pipe *pi)
2813 pi->stopped_cmds = 0;
2819 /* Check to see if any processes have exited -- if they
2820 * have, figure out why and see if a job has completed */
2821 static int checkjobs(struct pipe* fg_pipe)
2831 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2834 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2835 // /* avoid doing syscall, nothing there anyway */
2838 attributes = WUNTRACED;
2839 if (fg_pipe == NULL)
2840 attributes |= WNOHANG;
2842 /* Do we do this right?
2843 * bash-3.00# sleep 20 | false
2845 * [3]+ Stopped sleep 20 | false
2846 * bash-3.00# echo $?
2847 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2850 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2851 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2852 // + killall -STOP cat
2859 // i = G.count_SIGCHLD;
2860 childpid = waitpid(-1, &status, attributes);
2861 if (childpid <= 0) {
2862 if (childpid && errno != ECHILD)
2863 bb_perror_msg("waitpid");
2864 // else /* Until next SIGCHLD, waitpid's are useless */
2865 // G.handled_SIGCHLD = i;
2868 dead = WIFEXITED(status) || WIFSIGNALED(status);
2871 if (WIFSTOPPED(status))
2872 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2873 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2874 if (WIFSIGNALED(status))
2875 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2876 childpid, WTERMSIG(status), WEXITSTATUS(status));
2877 if (WIFEXITED(status))
2878 debug_printf_jobs("pid %d exited, exitcode %d\n",
2879 childpid, WEXITSTATUS(status));
2881 /* Were we asked to wait for fg pipe? */
2883 for (i = 0; i < fg_pipe->num_cmds; i++) {
2884 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2885 if (fg_pipe->cmds[i].pid != childpid)
2887 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2889 fg_pipe->cmds[i].pid = 0;
2890 fg_pipe->alive_cmds--;
2891 if (i == fg_pipe->num_cmds - 1) {
2892 /* last process gives overall exitstatus */
2893 rcode = WEXITSTATUS(status);
2894 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2897 fg_pipe->cmds[i].is_stopped = 1;
2898 fg_pipe->stopped_cmds++;
2900 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2901 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2902 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2903 /* All processes in fg pipe have exited/stopped */
2905 if (fg_pipe->alive_cmds)
2906 insert_bg_job(fg_pipe);
2910 /* There are still running processes in the fg pipe */
2911 goto wait_more; /* do waitpid again */
2913 /* it wasnt fg_pipe, look for process in bg pipes */
2917 /* We asked to wait for bg or orphaned children */
2918 /* No need to remember exitcode in this case */
2919 for (pi = G.job_list; pi; pi = pi->next) {
2920 for (i = 0; i < pi->num_cmds; i++) {
2921 if (pi->cmds[i].pid == childpid)
2922 goto found_pi_and_prognum;
2925 /* Happens when shell is used as init process (init=/bin/sh) */
2926 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2927 continue; /* do waitpid again */
2929 found_pi_and_prognum:
2932 pi->cmds[i].pid = 0;
2934 if (!pi->alive_cmds) {
2935 if (G_interactive_fd)
2936 printf(JOB_STATUS_FORMAT, pi->jobid,
2937 "Done", pi->cmdtext);
2938 delete_finished_bg_job(pi);
2942 pi->cmds[i].is_stopped = 1;
2946 } /* while (waitpid succeeds)... */
2952 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2955 int rcode = checkjobs(fg_pipe);
2956 /* Job finished, move the shell to the foreground */
2957 p = getpgid(0); /* pgid of our process */
2958 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2959 tcsetpgrp(G_interactive_fd, p);
2964 /* Start all the jobs, but don't wait for anything to finish.
2967 * Return code is normally -1, when the caller has to wait for children
2968 * to finish to determine the exit status of the pipe. If the pipe
2969 * is a simple builtin command, however, the action is done by the
2970 * time run_pipe returns, and the exit code is provided as the
2973 * Returns -1 only if started some children. IOW: we have to
2974 * mask out retvals of builtins etc with 0xff!
2976 * The only case when we do not need to [v]fork is when the pipe
2977 * is single, non-backgrounded, non-subshell command. Examples:
2978 * cmd ; ... { list } ; ...
2979 * cmd && ... { list } && ...
2980 * cmd || ... { list } || ...
2981 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2982 * or (if SH_STANDALONE) an applet, and we can run the { list }
2983 * with run_list(). If it isn't one of these, we fork and exec cmd.
2985 * Cases when we must fork:
2986 * non-single: cmd | cmd
2987 * backgrounded: cmd & { list } &
2988 * subshell: ( list ) [&]
2990 static int run_pipe(struct pipe *pi)
2992 static const char *const null_ptr = NULL;
2995 int pipefds[2]; /* pipefds[0] is for reading */
2996 struct command *command;
2997 char **argv_expanded;
3000 /* it is not always needed, but we aim to smaller code */
3001 int squirrel[] = { -1, -1, -1 };
3004 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3006 USE_HUSH_JOB(pi->pgrp = -1;)
3007 pi->stopped_cmds = 0;
3008 command = &(pi->cmds[0]);
3009 argv_expanded = NULL;
3011 if (pi->num_cmds != 1
3012 || pi->followup == PIPE_BG
3013 || command->grp_type == GRP_SUBSHELL
3020 debug_printf_exec(": group:%p argv:'%s'\n",
3021 command->group, command->argv ? command->argv[0] : "NONE");
3023 if (command->group) {
3024 #if ENABLE_HUSH_FUNCTIONS
3025 if (command->grp_type == GRP_FUNCTION) {
3026 /* func () { list } */
3027 bb_error_msg("here we ought to remember function definition, and go on");
3028 return EXIT_SUCCESS;
3032 debug_printf("non-subshell group\n");
3033 rcode = 1; /* exitcode if redir failed */
3034 if (setup_redirects(command, squirrel) == 0) {
3035 debug_printf_exec(": run_list\n");
3036 rcode = run_list(command->group) & 0xff;
3037 debug_printf_exec("run_pipe return %d\n", rcode);
3039 restore_redirects(squirrel);
3040 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3044 argv = command->argv ? command->argv : (char **) &null_ptr;
3046 const struct built_in_command *x;
3047 char **new_env = NULL;
3048 char **old_env = NULL;
3050 if (argv[command->assignment_cnt] == NULL) {
3051 /* Assignments, but no command */
3052 /* Ensure redirects take effect. Try "a=t >file" */
3053 rcode = setup_redirects(command, squirrel);
3054 restore_redirects(squirrel);
3055 /* Set shell variables */
3057 p = expand_string_to_string(*argv);
3058 debug_printf_exec("set shell var:'%s'->'%s'\n",
3060 set_local_var(p, 0, 0);
3063 /* Do we need to flag set_local_var() errors?
3064 * "assignment to readonly var" and "putenv error"
3066 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3070 /* Expand the rest into (possibly) many strings each */
3071 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3073 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
3074 if (strcmp(argv_expanded[0], x->cmd) != 0)
3076 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3077 debug_printf("exec with redirects only\n");
3078 rcode = setup_redirects(command, NULL);
3079 goto clean_up_and_ret1;
3081 debug_printf("builtin inline %s\n", argv_expanded[0]);
3082 /* XXX setup_redirects acts on file descriptors, not FILEs.
3083 * This is perfect for work that comes after exec().
3084 * Is it really safe for inline use? Experimentally,
3085 * things seem to work with glibc. */
3086 rcode = setup_redirects(command, squirrel);
3088 new_env = expand_assignments(argv, command->assignment_cnt);
3089 old_env = putenv_all_and_save_old(new_env);
3090 debug_printf_exec(": builtin '%s' '%s'...\n",
3091 x->cmd, argv_expanded[1]);
3092 rcode = x->function(argv_expanded) & 0xff;
3094 #if ENABLE_FEATURE_SH_STANDALONE
3097 restore_redirects(squirrel);
3098 free_strings_and_unsetenv(new_env, 1);
3099 putenv_all(old_env);
3100 /* Free the pointers, but the strings themselves
3101 * are in environ now, don't use free_strings! */
3104 free(argv_expanded);
3105 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3106 debug_printf_exec("run_pipe return %d\n", rcode);
3109 #if ENABLE_FEATURE_SH_STANDALONE
3110 i = find_applet_by_name(argv_expanded[0]);
3111 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3112 rcode = setup_redirects(command, squirrel);
3114 save_nofork_data(&G.nofork_save);
3115 new_env = expand_assignments(argv, command->assignment_cnt);
3116 old_env = putenv_all_and_save_old(new_env);
3117 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3118 argv_expanded[0], argv_expanded[1]);
3119 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3121 goto clean_up_and_ret;
3124 /* It is neither builtin nor applet. We must fork. */
3128 /* NB: argv_expanded may already be created, and that
3129 * might include `cmd` runs! Do not rerun it! We *must*
3130 * use argv_expanded if it's non-NULL */
3132 /* Going to fork a child per each pipe member */
3136 for (i = 0; i < pi->num_cmds; i++) {
3138 volatile nommu_save_t nommu_save;
3139 nommu_save.new_env = NULL;
3140 nommu_save.old_env = NULL;
3141 nommu_save.argv = NULL;
3143 command = &(pi->cmds[i]);
3144 if (command->argv) {
3145 debug_printf_exec(": pipe member '%s' '%s'...\n",
3146 command->argv[0], command->argv[1]);
3148 debug_printf_exec(": pipe member with no argv\n");
3151 /* pipes are inserted between pairs of commands */
3154 if ((i + 1) < pi->num_cmds)
3157 command->pid = BB_MMU ? fork() : vfork();
3158 if (!command->pid) { /* child */
3160 disable_restore_tty_pgrp_on_exit();
3162 /* Every child adds itself to new process group
3163 * with pgid == pid_of_first_child_in_pipe */
3164 if (G.run_list_level == 1 && G_interactive_fd) {
3167 if (pgrp < 0) /* true for 1st process only */
3169 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3170 /* We do it in *every* child, not just first,
3172 tcsetpgrp(G_interactive_fd, pgrp);
3176 xmove_fd(nextin, 0);
3177 xmove_fd(pipefds[1], 1); /* write end */
3179 close(pipefds[0]); /* read end */
3180 /* Like bash, explicit redirects override pipes,
3181 * and the pipe fd is available for dup'ing. */
3182 if (setup_redirects(command, NULL))
3185 /* Restore default handlers just prior to exec */
3186 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3188 /* Stores to nommu_save list of env vars putenv'ed
3189 * (NOMMU, on MMU we don't need that) */
3190 /* cast away volatility... */
3191 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3192 /* pseudo_exec() does not return */
3195 /* parent or error */
3196 enable_restore_tty_pgrp_on_exit();
3198 /* Clean up after vforked child */
3199 clean_up_after_re_execute();
3200 free(nommu_save.argv);
3201 free_strings_and_unsetenv(nommu_save.new_env, 1);
3202 putenv_all(nommu_save.old_env);
3203 /* Free the pointers, but the strings themselves
3204 * are in environ now, don't use free_strings! */
3205 free(nommu_save.old_env);
3207 free(argv_expanded);
3208 argv_expanded = NULL;
3209 if (command->pid < 0) { /* [v]fork failed */
3210 /* Clearly indicate, was it fork or vfork */
3211 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3215 /* Second and next children need to know pid of first one */
3217 pi->pgrp = command->pid;
3223 if ((i + 1) < pi->num_cmds)
3224 close(pipefds[1]); /* write end */
3225 /* Pass read (output) pipe end to next iteration */
3226 nextin = pipefds[0];
3229 if (!pi->alive_cmds) {
3230 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3234 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3238 #ifndef debug_print_tree
3239 static void debug_print_tree(struct pipe *pi, int lvl)
3241 static const char *const PIPE[] = {
3247 static const char *RES[] = {
3248 [RES_NONE ] = "NONE" ,
3251 [RES_THEN ] = "THEN" ,
3252 [RES_ELIF ] = "ELIF" ,
3253 [RES_ELSE ] = "ELSE" ,
3256 #if ENABLE_HUSH_LOOPS
3257 [RES_FOR ] = "FOR" ,
3258 [RES_WHILE] = "WHILE",
3259 [RES_UNTIL] = "UNTIL",
3261 [RES_DONE ] = "DONE" ,
3263 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3266 #if ENABLE_HUSH_CASE
3267 [RES_CASE ] = "CASE" ,
3268 [RES_MATCH] = "MATCH",
3269 [RES_CASEI] = "CASEI",
3270 [RES_ESAC ] = "ESAC" ,
3272 [RES_XXXX ] = "XXXX" ,
3273 [RES_SNTX ] = "SNTX" ,
3275 static const char *const GRPTYPE[] = {
3278 #if ENABLE_HUSH_FUNCTIONS
3287 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3288 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3290 while (prn < pi->num_cmds) {
3291 struct command *command = &pi->cmds[prn];
3292 char **argv = command->argv;
3294 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3296 command->assignment_cnt);
3297 if (command->group) {
3298 fprintf(stderr, " group %s: (argv=%p)\n",
3299 GRPTYPE[command->grp_type],
3301 debug_print_tree(command->group, lvl+1);
3305 if (argv) while (*argv) {
3306 fprintf(stderr, " '%s'", *argv);
3309 fprintf(stderr, "\n");
3318 /* NB: called by pseudo_exec, and therefore must not modify any
3319 * global data until exec/_exit (we can be a child after vfork!) */
3320 static int run_list(struct pipe *pi)
3322 #if ENABLE_HUSH_CASE
3323 char *case_word = NULL;
3325 #if ENABLE_HUSH_LOOPS
3326 struct pipe *loop_top = NULL;
3327 char *for_varname = NULL;
3328 char **for_lcur = NULL;
3329 char **for_list = NULL;
3331 smallint last_followup;
3333 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3334 smalluint cond_code = 0;
3336 enum { cond_code = 0 };
3339 smallint rword; /* enum reserved_style */
3340 smallint last_rword; /* ditto */
3343 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3345 #if ENABLE_HUSH_LOOPS
3346 /* Check syntax for "for" */
3347 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3348 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3350 /* current word is FOR or IN (BOLD in comments below) */
3351 if (cpipe->next == NULL) {
3352 syntax_error("malformed for");
3353 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3356 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3357 if (cpipe->next->res_word == RES_DO)
3359 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3360 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3361 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3363 syntax_error("malformed for");
3364 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3370 /* Past this point, all code paths should jump to ret: label
3371 * in order to return, no direct "return" statements please.
3372 * This helps to ensure that no memory is leaked. */
3374 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3377 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3378 * We are saving state before entering outermost list ("while...done")
3379 * so that ctrl-Z will correctly background _entire_ outermost list,
3380 * not just a part of it (like "sleep 1 | exit 2") */
3381 if (++G.run_list_level == 1 && G_interactive_fd) {
3382 if (sigsetjmp(G.toplevel_jb, 1)) {
3383 /* ctrl-Z forked and we are parent; or ctrl-C.
3384 * Sighandler has longjmped us here */
3385 signal(SIGINT, SIG_IGN);
3386 signal(SIGTSTP, SIG_IGN);
3387 /* Restore level (we can be coming from deep inside
3389 G.run_list_level = 1;
3390 #if ENABLE_FEATURE_SH_STANDALONE
3391 if (G.nofork_save.saved) { /* if save area is valid */
3392 debug_printf_jobs("exiting nofork early\n");
3393 restore_nofork_data(&G.nofork_save);
3396 //// if (G.ctrl_z_flag) {
3397 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3398 //// * Remember this child as background job */
3399 //// insert_bg_job(pi);
3401 /* ctrl-C. We just stop doing whatever we were doing */
3404 USE_HUSH_LOOPS(loop_top = NULL;)
3405 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3409 //// /* ctrl-Z handler will store pid etc in pi */
3410 //// G.toplevel_list = pi;
3411 //// G.ctrl_z_flag = 0;
3412 #if ENABLE_FEATURE_SH_STANDALONE
3413 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3415 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3416 //// signal(SIGINT, handler_ctrl_c);
3422 last_rword = RES_XXXX;
3424 last_followup = PIPE_SEQ;
3425 rcode = G.last_exitcode;
3427 /* Go through list of pipes, (maybe) executing them. */
3428 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3432 IF_HAS_KEYWORDS(rword = pi->res_word;)
3433 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3434 rword, cond_code, last_rword);
3435 #if ENABLE_HUSH_LOOPS
3436 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3437 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3439 /* start of a loop: remember where loop starts */
3444 /* Still in the same "if...", "then..." or "do..." branch? */
3445 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3446 if ((rcode == 0 && last_followup == PIPE_OR)
3447 || (rcode != 0 && last_followup == PIPE_AND)
3449 /* It is "<true> || CMD" or "<false> && CMD"
3450 * and we should not execute CMD */
3451 debug_printf_exec("skipped cmd because of || or &&\n");
3452 last_followup = pi->followup;
3456 last_followup = pi->followup;
3457 IF_HAS_KEYWORDS(last_rword = rword;)
3460 if (rword == RES_THEN) {
3461 /* if false; then ... fi has exitcode 0! */
3462 G.last_exitcode = rcode = EXIT_SUCCESS;
3463 /* "if <false> THEN cmd": skip cmd */
3467 if (rword == RES_ELSE || rword == RES_ELIF) {
3468 /* "if <true> then ... ELSE/ELIF cmd":
3469 * skip cmd and all following ones */
3474 #if ENABLE_HUSH_LOOPS
3475 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3477 /* first loop through for */
3479 static const char encoded_dollar_at[] ALIGN1 = {
3480 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3481 }; /* encoded representation of "$@" */
3482 static const char *const encoded_dollar_at_argv[] = {
3483 encoded_dollar_at, NULL
3484 }; /* argv list with one element: "$@" */
3487 vals = (char**)encoded_dollar_at_argv;
3488 if (pi->next->res_word == RES_IN) {
3489 /* if no variable values after "in" we skip "for" */
3490 if (!pi->next->cmds[0].argv) {
3491 G.last_exitcode = rcode = EXIT_SUCCESS;
3492 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3495 vals = pi->next->cmds[0].argv;
3496 } /* else: "for var; do..." -> assume "$@" list */
3497 /* create list of variable values */
3498 debug_print_strings("for_list made from", vals);
3499 for_list = expand_strvec_to_strvec(vals);
3500 for_lcur = for_list;
3501 debug_print_strings("for_list", for_list);
3502 for_varname = pi->cmds[0].argv[0];
3503 pi->cmds[0].argv[0] = NULL;
3505 free(pi->cmds[0].argv[0]);
3507 /* "for" loop is over, clean up */
3511 pi->cmds[0].argv[0] = for_varname;
3514 /* Insert next value from for_lcur */
3515 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3516 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3517 pi->cmds[0].assignment_cnt = 1;
3519 if (rword == RES_IN) {
3520 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3522 if (rword == RES_DONE) {
3523 continue; /* "done" has no cmds too */
3526 #if ENABLE_HUSH_CASE
3527 if (rword == RES_CASE) {
3528 case_word = expand_strvec_to_string(pi->cmds->argv);
3531 if (rword == RES_MATCH) {
3534 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3536 /* all prev words didn't match, does this one match? */
3537 argv = pi->cmds->argv;
3539 char *pattern = expand_string_to_string(*argv);
3540 /* TODO: which FNM_xxx flags to use? */
3541 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3543 if (cond_code == 0) { /* match! we will execute this branch */
3544 free(case_word); /* make future "word)" stop */
3552 if (rword == RES_CASEI) { /* inside of a case branch */
3554 continue; /* not matched yet, skip this pipe */
3557 /* Just pressing <enter> in shell should check for jobs.
3558 * OTOH, in non-interactive shell this is useless
3559 * and only leads to extra job checks */
3560 if (pi->num_cmds == 0) {
3561 if (G_interactive_fd)
3562 goto check_jobs_and_continue;
3566 /* After analyzing all keywords and conditions, we decided
3567 * to execute this pipe. NB: have to do checkjobs(NULL)
3568 * after run_pipe to collect any background children,
3569 * even if list execution is to be stopped. */
3570 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3573 #if ENABLE_HUSH_LOOPS
3574 G.flag_break_continue = 0;
3576 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3578 /* We only ran a builtin: rcode is already known
3579 * and we don't need to wait for anything. */
3580 G.last_exitcode = rcode;
3581 debug_printf_exec(": builtin exitcode %d\n", rcode);
3582 check_and_run_traps(0);
3583 #if ENABLE_HUSH_LOOPS
3584 /* Was it "break" or "continue"? */
3585 if (G.flag_break_continue) {
3586 smallint fbc = G.flag_break_continue;
3587 /* We might fall into outer *loop*,
3588 * don't want to break it too */
3590 G.depth_break_continue--;
3591 if (G.depth_break_continue == 0)
3592 G.flag_break_continue = 0;
3593 /* else: e.g. "continue 2" should *break* once, *then* continue */
3594 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3595 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3596 goto check_jobs_and_break;
3597 /* "continue": simulate end of loop */
3602 } else if (pi->followup == PIPE_BG) {
3603 /* What does bash do with attempts to background builtins? */
3604 /* even bash 3.2 doesn't do that well with nested bg:
3605 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3606 * I'm NOT treating inner &'s as jobs */
3607 check_and_run_traps(0);
3609 if (G.run_list_level == 1)
3612 G.last_exitcode = rcode = EXIT_SUCCESS;
3613 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3616 if (G.run_list_level == 1 && G_interactive_fd) {
3617 /* Waits for completion, then fg's main shell */
3618 rcode = checkjobs_and_fg_shell(pi);
3619 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3620 check_and_run_traps(0);
3623 { /* This one just waits for completion */
3624 rcode = checkjobs(pi);
3625 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3626 check_and_run_traps(0);
3628 G.last_exitcode = rcode;
3632 /* Analyze how result affects subsequent commands */
3634 if (rword == RES_IF || rword == RES_ELIF)
3637 #if ENABLE_HUSH_LOOPS
3638 /* Beware of "while false; true; do ..."! */
3639 if (pi->next && pi->next->res_word == RES_DO) {
3640 if (rword == RES_WHILE) {
3642 /* "while false; do...done" - exitcode 0 */
3643 G.last_exitcode = rcode = EXIT_SUCCESS;
3644 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3645 goto check_jobs_and_break;
3648 if (rword == RES_UNTIL) {
3650 debug_printf_exec(": until expr is true: breaking\n");
3651 check_jobs_and_break:
3659 check_jobs_and_continue:
3664 //// if (G.ctrl_z_flag) {
3665 //// /* ctrl-Z forked somewhere in the past, we are the child,
3666 //// * and now we completed running the list. Exit. */
3672 //// if (!G.run_list_level && G_interactive_fd) {
3673 //// signal(SIGTSTP, SIG_IGN);
3674 //// signal(SIGINT, SIG_IGN);
3677 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3678 #if ENABLE_HUSH_LOOPS
3683 #if ENABLE_HUSH_CASE
3689 /* Select which version we will use */
3690 static int run_and_free_list(struct pipe *pi)
3693 debug_printf_exec("run_and_free_list entered\n");
3695 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3696 rcode = run_list(pi);
3698 /* free_pipe_list has the side effect of clearing memory.
3699 * In the long run that function can be merged with run_list,
3700 * but doing that now would hobble the debugging effort. */
3701 free_pipe_list(pi, /* indent: */ 0);
3702 debug_printf_exec("run_and_free_list return %d\n", rcode);
3707 static struct pipe *new_pipe(void)
3710 pi = xzalloc(sizeof(struct pipe));
3711 /*pi->followup = 0; - deliberately invalid value */
3712 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3716 /* Command (member of a pipe) is complete. The only possible error here
3717 * is out of memory, in which case xmalloc exits. */
3718 static int done_command(struct parse_context *ctx)
3720 /* The command is really already in the pipe structure, so
3721 * advance the pipe counter and make a new, null command. */
3722 struct pipe *pi = ctx->pipe;
3723 struct command *command = ctx->command;
3726 if (command->group == NULL
3727 && command->argv == NULL
3728 && command->redirects == NULL
3730 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3731 memset(command, 0, sizeof(*command)); /* paranoia */
3732 return pi->num_cmds;
3735 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3736 //debug_print_tree(ctx->list_head, 20);
3738 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3741 /* Only real trickiness here is that the uncommitted
3742 * command structure is not counted in pi->num_cmds. */
3743 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3744 command = &pi->cmds[pi->num_cmds];
3745 memset(command, 0, sizeof(*command));
3747 ctx->command = command;
3748 /* but ctx->pipe and ctx->list_head remain unchanged */
3750 return pi->num_cmds; /* used only for 0/nonzero check */
3753 static void done_pipe(struct parse_context *ctx, pipe_style type)
3757 debug_printf_parse("done_pipe entered, followup %d\n", type);
3758 /* Close previous command */
3759 not_null = done_command(ctx);
3760 ctx->pipe->followup = type;
3762 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3763 ctx->ctx_inverted = 0;
3764 ctx->pipe->res_word = ctx->ctx_res_w;
3767 /* Without this check, even just <enter> on command line generates
3768 * tree of three NOPs (!). Which is harmless but annoying.
3769 * IOW: it is safe to do it unconditionally.
3770 * RES_NONE case is for "for a in; do ..." (empty IN set)
3771 * and other cases to work. */
3774 || ctx->ctx_res_w == RES_FI
3775 || ctx->ctx_res_w == RES_DONE
3776 || ctx->ctx_res_w == RES_FOR
3777 || ctx->ctx_res_w == RES_IN
3778 || ctx->ctx_res_w == RES_ESAC
3782 debug_printf_parse("done_pipe: adding new pipe: "
3783 "not_null:%d ctx->ctx_res_w:%d\n",
3784 not_null, ctx->ctx_res_w);
3786 ctx->pipe->next = new_p;
3788 /* RES_THEN, RES_DO etc are "sticky" -
3789 * they remain set for commands inside if/while.
3790 * This is used to control execution.
3791 * RES_FOR and RES_IN are NOT sticky (needed to support
3792 * cases where variable or value happens to match a keyword):
3794 #if ENABLE_HUSH_LOOPS
3795 if (ctx->ctx_res_w == RES_FOR
3796 || ctx->ctx_res_w == RES_IN)
3797 ctx->ctx_res_w = RES_NONE;
3799 #if ENABLE_HUSH_CASE
3800 if (ctx->ctx_res_w == RES_MATCH)
3801 ctx->ctx_res_w = RES_CASEI;
3803 ctx->command = NULL; /* trick done_command below */
3804 /* Create the memory for command, roughly:
3805 * ctx->pipe->cmds = new struct command;
3806 * ctx->command = &ctx->pipe->cmds[0];
3809 //debug_print_tree(ctx->list_head, 10);
3811 debug_printf_parse("done_pipe return\n");
3814 static void initialize_context(struct parse_context *ctx)
3816 memset(ctx, 0, sizeof(*ctx));
3817 ctx->pipe = ctx->list_head = new_pipe();
3818 /* Create the memory for command, roughly:
3819 * ctx->pipe->cmds = new struct command;
3820 * ctx->command = &ctx->pipe->cmds[0];
3825 /* If a reserved word is found and processed, parse context is modified
3826 * and 1 is returned.
3829 struct reserved_combo {
3832 unsigned char assignment_flag;
3836 FLAG_END = (1 << RES_NONE ),
3838 FLAG_IF = (1 << RES_IF ),
3839 FLAG_THEN = (1 << RES_THEN ),
3840 FLAG_ELIF = (1 << RES_ELIF ),
3841 FLAG_ELSE = (1 << RES_ELSE ),
3842 FLAG_FI = (1 << RES_FI ),
3844 #if ENABLE_HUSH_LOOPS
3845 FLAG_FOR = (1 << RES_FOR ),
3846 FLAG_WHILE = (1 << RES_WHILE),
3847 FLAG_UNTIL = (1 << RES_UNTIL),
3848 FLAG_DO = (1 << RES_DO ),
3849 FLAG_DONE = (1 << RES_DONE ),
3850 FLAG_IN = (1 << RES_IN ),
3852 #if ENABLE_HUSH_CASE
3853 FLAG_MATCH = (1 << RES_MATCH),
3854 FLAG_ESAC = (1 << RES_ESAC ),
3856 FLAG_START = (1 << RES_XXXX ),
3859 static const struct reserved_combo* match_reserved_word(o_string *word)
3861 /* Mostly a list of accepted follow-up reserved words.
3862 * FLAG_END means we are done with the sequence, and are ready
3863 * to turn the compound list into a command.
3864 * FLAG_START means the word must start a new compound list.
3866 static const struct reserved_combo reserved_list[] = {
3868 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3869 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3870 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3871 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3872 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3873 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3875 #if ENABLE_HUSH_LOOPS
3876 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3877 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3878 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3879 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3880 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3881 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3883 #if ENABLE_HUSH_CASE
3884 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3885 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3888 const struct reserved_combo *r;
3890 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3891 if (strcmp(word->data, r->literal) == 0)
3896 static int reserved_word(o_string *word, struct parse_context *ctx)
3898 #if ENABLE_HUSH_CASE
3899 static const struct reserved_combo reserved_match = {
3900 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3903 const struct reserved_combo *r;
3905 r = match_reserved_word(word);
3909 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3910 #if ENABLE_HUSH_CASE
3911 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3912 /* "case word IN ..." - IN part starts first match part */
3913 r = &reserved_match;
3916 if (r->flag == 0) { /* '!' */
3917 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3918 syntax_error("! ! command");
3919 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3921 ctx->ctx_inverted = 1;
3924 if (r->flag & FLAG_START) {
3925 struct parse_context *old;
3926 old = xmalloc(sizeof(*old));
3927 debug_printf_parse("push stack %p\n", old);
3928 *old = *ctx; /* physical copy */
3929 initialize_context(ctx);
3931 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3932 syntax_error_at(word->data);
3933 ctx->ctx_res_w = RES_SNTX;
3936 ctx->ctx_res_w = r->res;
3937 ctx->old_flag = r->flag;
3938 if (ctx->old_flag & FLAG_END) {
3939 struct parse_context *old;
3940 done_pipe(ctx, PIPE_SEQ);
3941 debug_printf_parse("pop stack %p\n", ctx->stack);
3943 old->command->group = ctx->list_head;
3944 old->command->grp_type = GRP_NORMAL;
3946 o_addstr(&old->as_string, ctx->as_string.data);
3947 o_free_unsafe(&ctx->as_string);
3948 old->command->group_as_string = xstrdup(old->as_string.data);
3949 debug_printf_parse("pop, remembering as:'%s'\n",
3950 old->command->group_as_string);
3952 *ctx = *old; /* physical copy */
3955 word->o_assignment = r->assignment_flag;
3960 /* Word is complete, look at it and update parsing context.
3961 * Normal return is 0. Syntax errors return 1.
3962 * Note: on return, word is reset, but not o_free'd!
3964 static int done_word(o_string *word, struct parse_context *ctx)
3966 struct command *command = ctx->command;
3968 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3969 if (word->length == 0 && word->o_quoted == 0) {
3970 debug_printf_parse("done_word return 0: true null, ignored\n");
3974 if (ctx->pending_redirect) {
3975 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3976 * only if run as "bash", not "sh" */
3977 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3979 * ...the word that follows the redirection operator
3980 * shall be subjected to tilde expansion, parameter expansion,
3981 * command substitution, arithmetic expansion, and quote
3982 * removal. Pathname expansion shall not be performed
3983 * on the word by a non-interactive shell; an interactive
3984 * shell may perform it, but shall do so only when
3985 * the expansion would result in one word."
3987 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3988 /* Cater for >\file case:
3989 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3990 * Same with heredocs:
3991 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3993 unbackslash(ctx->pending_redirect->rd_filename);
3994 /* Is it <<"HEREDOC"? */
3995 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3998 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4000 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4002 /* If this word wasn't an assignment, next ones definitely
4003 * can't be assignments. Even if they look like ones. */
4004 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4005 && word->o_assignment != WORD_IS_KEYWORD
4007 word->o_assignment = NOT_ASSIGNMENT;
4009 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4010 command->assignment_cnt++;
4011 word->o_assignment = MAYBE_ASSIGNMENT;
4014 if (command->group) {
4015 /* "{ echo foo; } echo bar" - bad */
4016 /* NB: bash allows e.g.:
4017 * if true; then { echo foo; } fi
4018 * while if false; then false; fi do break; done
4020 * while if false; then false; fi; do; break; done
4022 syntax_error_at(word->data);
4023 debug_printf_parse("done_word return 1: syntax error, "
4024 "groups and arglists don't mix\n");
4028 # if ENABLE_HUSH_CASE
4029 if (ctx->ctx_dsemicolon
4030 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4032 /* already done when ctx_dsemicolon was set to 1: */
4033 /* ctx->ctx_res_w = RES_MATCH; */
4034 ctx->ctx_dsemicolon = 0;
4037 if (!command->argv /* if it's the first word... */
4038 # if ENABLE_HUSH_LOOPS
4039 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4040 && ctx->ctx_res_w != RES_IN
4043 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4044 if (reserved_word(word, ctx)) {
4046 debug_printf_parse("done_word return %d\n",
4047 (ctx->ctx_res_w == RES_SNTX));
4048 return (ctx->ctx_res_w == RES_SNTX);
4052 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4053 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4054 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4055 /* (otherwise it's known to be not empty and is already safe) */
4057 /* exclude "$@" - it can expand to no word despite "" */
4058 char *p = word->data;
4059 while (p[0] == SPECIAL_VAR_SYMBOL
4060 && (p[1] & 0x7f) == '@'
4061 && p[2] == SPECIAL_VAR_SYMBOL
4065 if (p == word->data || p[0] != '\0') {
4066 /* saw no "$@", or not only "$@" but some
4067 * real text is there too */
4068 /* insert "empty variable" reference, this makes
4069 * e.g. "", $empty"" etc to not disappear */
4070 o_addchr(word, SPECIAL_VAR_SYMBOL);
4071 o_addchr(word, SPECIAL_VAR_SYMBOL);
4074 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4075 debug_print_strings("word appended to argv", command->argv);
4079 ctx->pending_redirect = NULL;
4081 #if ENABLE_HUSH_LOOPS
4082 /* Force FOR to have just one word (variable name) */
4083 /* NB: basically, this makes hush see "for v in ..." syntax as if
4084 * as it is "for v; in ...". FOR and IN become two pipe structs
4086 if (ctx->ctx_res_w == RES_FOR) {
4087 if (!is_well_formed_var_name(command->argv[0], '\0')) {
4088 syntax_error("malformed variable name in for");
4091 done_pipe(ctx, PIPE_SEQ);
4094 #if ENABLE_HUSH_CASE
4095 /* Force CASE to have just one word */
4096 if (ctx->ctx_res_w == RES_CASE) {
4097 done_pipe(ctx, PIPE_SEQ);
4100 debug_printf_parse("done_word return 0\n");
4105 /* Peek ahead in the input to find out if we have a "&n" construct,
4106 * as in "2>&1", that represents duplicating a file descriptor.
4108 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4109 * REDIRFD_SYNTAX_ERR if syntax error,
4110 * REDIRFD_TO_FILE if no & was seen,
4111 * or the number found.
4114 #define parse_redir_right_fd(as_string, input) \
4115 parse_redir_right_fd(input)
4117 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4123 return REDIRFD_TO_FILE;
4125 ch = i_getch(input); /* get the & */
4126 nommu_addchr(as_string, ch);
4129 ch = i_getch(input);
4130 nommu_addchr(as_string, ch);
4131 return REDIRFD_CLOSE;
4135 while (ch != EOF && isdigit(ch)) {
4136 d = d*10 + (ch-'0');
4138 ch = i_getch(input);
4139 nommu_addchr(as_string, ch);
4144 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4146 bb_error_msg("ambiguous redirect");
4147 return REDIRFD_SYNTAX_ERR;
4150 /* Return code is 0 normal, 1 if a syntax error is detected
4152 static int parse_redirect(struct parse_context *ctx,
4155 struct in_str *input)
4157 struct command *command = ctx->command;
4158 struct redir_struct *redir;
4159 struct redir_struct **redirp;
4162 dup_num = REDIRFD_TO_FILE;
4163 if (style != REDIRECT_HEREDOC) {
4164 /* Check for a '>&1' type redirect */
4165 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4166 if (dup_num == REDIRFD_SYNTAX_ERR)
4169 int ch = i_peek(input);
4170 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4171 if (dup_num) { /* <<-... */
4172 ch = i_getch(input);
4173 nommu_addchr(&ctx->as_string, ch);
4178 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4179 int ch = i_peek(input);
4181 /* >|FILE redirect ("clobbering" >).
4182 * Since we do not support "set -o noclobber" yet,
4183 * >| and > are the same for now. Just eat |.
4185 ch = i_getch(input);
4186 nommu_addchr(&ctx->as_string, ch);
4190 /* Create a new redir_struct and append it to the linked list */
4191 redirp = &command->redirects;
4192 while ((redir = *redirp) != NULL) {
4193 redirp = &(redir->next);
4195 *redirp = redir = xzalloc(sizeof(*redir));
4196 /* redir->next = NULL; */
4197 /* redir->rd_filename = NULL; */
4198 redir->rd_type = style;
4199 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4201 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4202 redir_table[style].descrip);
4204 redir->rd_dup = dup_num;
4205 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4206 /* Erik had a check here that the file descriptor in question
4207 * is legit; I postpone that to "run time"
4208 * A "-" representation of "close me" shows up as a -3 here */
4209 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4210 redir->rd_fd, redir->rd_dup);
4212 /* Set ctx->pending_redirect, so we know what to do at the
4213 * end of the next parsed word. */
4214 ctx->pending_redirect = redir;
4219 /* If a redirect is immediately preceded by a number, that number is
4220 * supposed to tell which file descriptor to redirect. This routine
4221 * looks for such preceding numbers. In an ideal world this routine
4222 * needs to handle all the following classes of redirects...
4223 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4224 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4225 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4226 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4228 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4230 * ... If n is quoted, the number shall not be recognized as part of
4231 * the redirection expression. For example:
4233 * writes the character 2 into file a"
4234 * We are getting it right by setting ->o_quoted on any \<char>
4236 * A -1 return means no valid number was found,
4237 * the caller should use the appropriate default for this redirection.
4239 static int redirect_opt_num(o_string *o)
4243 if (o->data == NULL)
4245 num = bb_strtou(o->data, NULL, 10);
4246 if (errno || num < 0)
4253 #define fetch_till_str(as_string, input, word, skip_tabs) \
4254 fetch_till_str(input, word, skip_tabs)
4256 static char *fetch_till_str(o_string *as_string,
4257 struct in_str *input,
4261 o_string heredoc = NULL_O_STRING;
4267 ch = i_getch(input);
4268 nommu_addchr(as_string, ch);
4270 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4271 heredoc.data[past_EOL] = '\0';
4272 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4273 return heredoc.data;
4276 o_addchr(&heredoc, ch);
4277 past_EOL = heredoc.length;
4280 ch = i_getch(input);
4281 nommu_addchr(as_string, ch);
4282 } while (skip_tabs && ch == '\t');
4283 } while (ch == '\n');
4286 o_free_unsafe(&heredoc);
4289 o_addchr(&heredoc, ch);
4290 nommu_addchr(as_string, ch);
4294 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4295 * and load them all. There should be exactly heredoc_cnt of them.
4297 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4299 struct pipe *pi = ctx->list_head;
4301 while (pi && heredoc_cnt) {
4303 struct command *cmd = pi->cmds;
4305 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4307 cmd->argv ? cmd->argv[0] : "NONE");
4308 for (i = 0; i < pi->num_cmds; i++) {
4309 struct redir_struct *redir = cmd->redirects;
4311 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4312 i, cmd->argv ? cmd->argv[0] : "NONE");
4314 if (redir->rd_type == REDIRECT_HEREDOC) {
4317 redir->rd_type = REDIRECT_HEREDOC2;
4318 /* redir->dup is (ab)used to indicate <<- */
4319 p = fetch_till_str(&ctx->as_string, input,
4320 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4322 syntax_error("unexpected EOF in here document");
4325 free(redir->rd_filename);
4326 redir->rd_filename = p;
4329 redir = redir->next;
4336 /* Should be 0. If it isn't, it's a parse error */
4338 bb_error_msg_and_die("heredoc BUG 2");
4345 #define parse_stream(pstring, input, end_trigger) \
4346 parse_stream(input, end_trigger)
4348 static struct pipe *parse_stream(char **pstring,
4349 struct in_str *input,
4351 static void parse_and_run_string(const char *s);
4353 #if ENABLE_HUSH_TICK
4354 static FILE *generate_stream_from_string(const char *s)
4357 int pid, channel[2];
4360 pid = BB_MMU ? fork() : vfork();
4362 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4364 if (pid == 0) { /* child */
4365 disable_restore_tty_pgrp_on_exit();
4366 /* Process substitution is not considered to be usual
4367 * 'command execution'.
4368 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4375 close(channel[0]); /* NB: close _first_, then move fd! */
4376 xmove_fd(channel[1], 1);
4377 /* Prevent it from trying to handle ctrl-z etc */
4378 USE_HUSH_JOB(G.run_list_level = 1;)
4380 reset_traps_to_defaults();
4381 parse_and_run_string(s);
4382 _exit(G.last_exitcode);
4384 /* We re-execute after vfork on NOMMU. This makes this script safe:
4385 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4386 * huge=`cat BIG` # was blocking here forever
4389 re_execute_shell(s, 0);
4394 enable_restore_tty_pgrp_on_exit();
4395 clean_up_after_re_execute();
4397 pf = fdopen(channel[0], "r");
4401 /* Return code is exit status of the process that is run. */
4402 static int process_command_subs(o_string *dest, const char *s)
4405 struct in_str pipe_str;
4408 pf = generate_stream_from_string(s);
4411 close_on_exec_on(fileno(pf));
4413 /* Now send results of command back into original context */
4414 setup_file_in_str(&pipe_str, pf);
4416 while ((ch = i_getch(&pipe_str)) != EOF) {
4422 o_addchr(dest, '\n');
4425 o_addQchr(dest, ch);
4428 debug_printf("done reading from pipe, pclose()ing\n");
4429 /* Note: we got EOF, and we just close the read end of the pipe.
4430 * We do not wait for the `cmd` child to terminate. bash and ash do.
4432 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4433 * `false`; echo $? - bash outputs "1"
4436 debug_printf("closed FILE from child. return 0\n");
4441 static int parse_group(o_string *dest, struct parse_context *ctx,
4442 struct in_str *input, int ch)
4444 /* dest contains characters seen prior to ( or {.
4445 * Typically it's empty, but for function defs,
4446 * it contains function name (without '()'). */
4447 struct pipe *pipe_list;
4449 struct command *command = ctx->command;
4451 debug_printf_parse("parse_group entered\n");
4452 #if ENABLE_HUSH_FUNCTIONS
4453 if (ch == 'F') { /* function definition? */
4454 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4455 //command->fname = dest->data;
4456 command->grp_type = GRP_FUNCTION;
4457 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4458 memset(dest, 0, sizeof(*dest));
4461 if (command->argv /* word [word](... */
4462 || dest->length /* word(... */
4463 || dest->o_quoted /* ""(... */
4466 debug_printf_parse("parse_group return 1: "
4467 "syntax error, groups and arglists don't mix\n");
4473 command->grp_type = GRP_SUBSHELL;
4477 char *as_string = NULL;
4479 pipe_list = parse_stream(&as_string, input, endch);
4482 o_addstr(&ctx->as_string, as_string);
4484 /* empty ()/{} or parse error? */
4485 if (!pipe_list || pipe_list == ERR_PTR) {
4490 debug_printf_parse("parse_group return 1: "
4491 "parse_stream returned %p\n", pipe_list);
4494 command->group = pipe_list;
4496 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4497 command->group_as_string = as_string;
4498 debug_printf_parse("end of group, remembering as:'%s'\n",
4499 command->group_as_string);
4502 debug_printf_parse("parse_group return 0\n");
4504 /* command remains "open", available for possible redirects */
4507 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4508 /* Subroutines for copying $(...) and `...` things */
4509 static int add_till_backquote(o_string *dest, struct in_str *input);
4511 static int add_till_single_quote(o_string *dest, struct in_str *input)
4514 int ch = i_getch(input);
4516 syntax_error_unterm_ch('\'');
4524 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4525 static int add_till_double_quote(o_string *dest, struct in_str *input)
4528 int ch = i_getch(input);
4530 syntax_error_unterm_ch('"');
4535 if (ch == '\\') { /* \x. Copy both chars. */
4537 ch = i_getch(input);
4541 if (add_till_backquote(dest, input))
4546 //if (ch == '$') ...
4549 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4551 * "Within the backquoted style of command substitution, backslash
4552 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4553 * The search for the matching backquote shall be satisfied by the first
4554 * backquote found without a preceding backslash; during this search,
4555 * if a non-escaped backquote is encountered within a shell comment,
4556 * a here-document, an embedded command substitution of the $(command)
4557 * form, or a quoted string, undefined results occur. A single-quoted
4558 * or double-quoted string that begins, but does not end, within the
4559 * "`...`" sequence produces undefined results."
4561 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4563 static int add_till_backquote(o_string *dest, struct in_str *input)
4566 int ch = i_getch(input);
4568 syntax_error_unterm_ch('`');
4574 /* \x. Copy both chars unless it is \` */
4575 int ch2 = i_getch(input);
4577 syntax_error_unterm_ch('`');
4580 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4587 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4588 * quoting and nested ()s.
4589 * "With the $(command) style of command substitution, all characters
4590 * following the open parenthesis to the matching closing parenthesis
4591 * constitute the command. Any valid shell script can be used for command,
4592 * except a script consisting solely of redirections which produces
4593 * unspecified results."
4595 * echo $(echo '(TEST)' BEST) (TEST) BEST
4596 * echo $(echo 'TEST)' BEST) TEST) BEST
4597 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4599 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4603 int ch = i_getch(input);
4605 syntax_error_unterm_ch(')');
4614 if (i_peek(input) == ')') {
4622 if (add_till_single_quote(dest, input))
4628 if (add_till_double_quote(dest, input))
4634 /* \x. Copy verbatim. Important for \(, \) */
4635 ch = i_getch(input);
4637 syntax_error_unterm_ch(')');
4646 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4648 /* Return code: 0 for OK, 1 for syntax error */
4650 #define handle_dollar(as_string, dest, input) \
4651 handle_dollar(dest, input)
4653 static int handle_dollar(o_string *as_string,
4655 struct in_str *input)
4658 int ch = i_peek(input); /* first character after the $ */
4659 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4661 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4663 ch = i_getch(input);
4664 nommu_addchr(as_string, ch);
4666 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4668 debug_printf_parse(": '%c'\n", ch);
4669 o_addchr(dest, ch | quote_mask);
4672 if (!isalnum(ch) && ch != '_')
4674 ch = i_getch(input);
4675 nommu_addchr(as_string, ch);
4677 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4678 } else if (isdigit(ch)) {
4680 ch = i_getch(input);
4681 nommu_addchr(as_string, ch);
4682 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4683 debug_printf_parse(": '%c'\n", ch);
4684 o_addchr(dest, ch | quote_mask);
4685 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4686 } else switch (ch) {
4688 case '!': /* last bg pid */
4689 case '?': /* last exit code */
4690 case '#': /* number of args */
4691 case '*': /* args */
4692 case '@': /* args */
4693 goto make_one_char_var;
4695 bool first_char, all_digits;
4697 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4698 ch = i_getch(input);
4699 nommu_addchr(as_string, ch);
4700 /* XXX maybe someone will try to escape the '}' */
4705 ch = i_getch(input);
4706 nommu_addchr(as_string, ch);
4712 /* ${#var}: length of var contents */
4714 else if (isdigit(ch)) {
4721 && ( (all_digits && !isdigit(ch))
4722 || (!all_digits && !isalnum(ch) && ch != '_')
4725 /* handle parameter expansions
4726 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4731 case ':': /* null modifier */
4732 if (expansion == 0) {
4733 debug_printf_parse(": null modifier\n");
4738 case '#': /* remove prefix */
4739 case '%': /* remove suffix */
4740 if (expansion == 0) {
4741 debug_printf_parse(": remove suffix/prefix\n");
4746 case '-': /* default value */
4747 case '=': /* assign default */
4748 case '+': /* alternative */
4749 case '?': /* error indicate */
4750 debug_printf_parse(": parameter expansion\n");
4755 syntax_error_unterm_str("${name}");
4756 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4761 debug_printf_parse(": '%c'\n", ch);
4762 o_addchr(dest, ch | quote_mask);
4766 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4769 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4774 ch = i_getch(input);
4775 nommu_addchr(as_string, ch);
4776 # if ENABLE_SH_MATH_SUPPORT
4777 if (i_peek(input) == '(') {
4778 ch = i_getch(input);
4779 nommu_addchr(as_string, ch);
4780 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4781 o_addchr(dest, /*quote_mask |*/ '+');
4785 if (add_till_closing_paren(dest, input, true))
4789 o_addstr(as_string, dest->data + pos);
4790 o_addchr(as_string, ')');
4791 o_addchr(as_string, ')');
4794 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4798 # if ENABLE_HUSH_TICK
4799 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4800 o_addchr(dest, quote_mask | '`');
4804 if (add_till_closing_paren(dest, input, false))
4808 o_addstr(as_string, dest->data + pos);
4809 o_addchr(as_string, '`');
4812 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4818 ch = i_getch(input);
4819 nommu_addchr(as_string, ch);
4821 if (isalnum(ch)) { /* it's $_name or $_123 */
4827 /* $_ Shell or shell script name; or last cmd name */
4828 /* $- Option flags set by set builtin or shell options (-i etc) */
4830 o_addQchr(dest, '$');
4832 debug_printf_parse("handle_dollar return 0\n");
4837 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4838 parse_stream_dquoted(dest, input, dquote_end)
4840 static int parse_stream_dquoted(o_string *as_string,
4842 struct in_str *input,
4849 ch = i_getch(input);
4851 nommu_addchr(as_string, ch);
4852 if (ch == dquote_end) { /* may be only '"' or EOF */
4853 if (dest->o_assignment == NOT_ASSIGNMENT)
4854 dest->o_escape ^= 1;
4855 debug_printf_parse("parse_stream_dquoted return 0\n");
4858 /* note: can't move it above ch == dquote_end check! */
4860 syntax_error_unterm_ch('"');
4861 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4866 next = i_peek(input);
4868 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4869 ch, ch, dest->o_escape);
4871 //TODO: check interactive behavior
4873 syntax_error("\\<eof>");
4874 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4878 * "The backslash retains its special meaning [in "..."]
4879 * only when followed by one of the following characters:
4880 * $, `, ", \, or <newline>. A double quote may be quoted
4881 * within double quotes by preceding it with a backslash.
4883 if (strchr("$`\"\\", next) != NULL) {
4884 o_addqchr(dest, i_getch(input));
4886 o_addqchr(dest, '\\');
4891 if (handle_dollar(as_string, dest, input) != 0) {
4892 debug_printf_parse("parse_stream_dquoted return 1: "
4893 "handle_dollar returned non-0\n");
4898 #if ENABLE_HUSH_TICK
4900 //int pos = dest->length;
4901 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4902 o_addchr(dest, 0x80 | '`');
4903 if (add_till_backquote(dest, input))
4905 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4906 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4910 o_addQchr(dest, ch);
4912 && (dest->o_assignment == MAYBE_ASSIGNMENT
4913 || dest->o_assignment == WORD_IS_KEYWORD)
4914 && is_well_formed_var_name(dest->data, '=')
4916 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4922 * Scan input until EOF or end_trigger char.
4923 * Return a list of pipes to execute, or NULL on EOF
4924 * or if end_trigger character is met.
4925 * On syntax error, exit is shell is not interactive,
4926 * reset parsing machinery and start parsing anew,
4927 * or return ERR_PTR.
4929 static struct pipe *parse_stream(char **pstring,
4930 struct in_str *input,
4933 struct parse_context ctx;
4934 o_string dest = NULL_O_STRING;
4938 /* Double-quote state is handled in the state variable is_in_dquote.
4939 * A single-quote triggers a bypass of the main loop until its mate is
4940 * found. When recursing, quote state is passed in via dest->o_escape.
4942 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4943 end_trigger ? : 'X');
4945 G.ifs = get_local_var_value("IFS");
4950 #if ENABLE_HUSH_INTERACTIVE
4951 input->promptmode = 0; /* PS1 */
4953 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4954 initialize_context(&ctx);
4959 const char *is_special;
4963 redir_type redir_style;
4966 /* dest.o_quoted = 1; - already is (see below) */
4967 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4970 /* We reached closing '"' */
4973 ch = i_getch(input);
4974 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4975 ch, ch, dest.o_escape);
4980 syntax_error_unterm_str("here document");
4983 if (done_word(&dest, &ctx)) {
4987 done_pipe(&ctx, PIPE_SEQ);
4989 /* If we got nothing... */
4990 // TODO: test script consisting of just "&"
4991 if (pi->num_cmds == 0
4992 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4994 free_pipe_list(pi, 0);
4997 debug_printf_parse("parse_stream return %p\n", pi);
4999 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5001 *pstring = ctx.as_string.data;
5003 o_free_unsafe(&ctx.as_string);
5007 nommu_addchr(&ctx.as_string, ch);
5008 is_ifs = strchr(G.ifs, ch);
5009 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5010 "\\$\"" USE_HUSH_TICK("`") /* always special */
5013 if (!is_special && !is_ifs) { /* ordinary char */
5014 o_addQchr(&dest, ch);
5015 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5016 || dest.o_assignment == WORD_IS_KEYWORD)
5018 && is_well_formed_var_name(dest.data, '=')
5020 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5026 if (done_word(&dest, &ctx)) {
5030 #if ENABLE_HUSH_CASE
5031 /* "case ... in <newline> word) ..." -
5032 * newlines are ignored (but ';' wouldn't be) */
5033 if (ctx.command->argv == NULL
5034 && ctx.ctx_res_w == RES_MATCH
5039 /* Treat newline as a command separator. */
5040 done_pipe(&ctx, PIPE_SEQ);
5041 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5043 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5048 dest.o_assignment = MAYBE_ASSIGNMENT;
5050 /* note: if (is_ifs) continue;
5051 * will still trigger for us */
5054 if (end_trigger && end_trigger == ch
5055 && (heredoc_cnt == 0 || end_trigger != ';')
5057 //TODO: disallow "{ cmd }" without semicolon
5059 /* This is technically valid:
5060 * { cat <<HERE; }; echo Ok
5065 * but we don't support this.
5066 * We require heredoc to be in enclosing {}/(),
5069 syntax_error_unterm_str("here document");
5072 if (done_word(&dest, &ctx)) {
5075 done_pipe(&ctx, PIPE_SEQ);
5076 dest.o_assignment = MAYBE_ASSIGNMENT;
5077 /* Do we sit outside of any if's, loops or case's? */
5079 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5081 debug_printf_parse("parse_stream return %p: "
5082 "end_trigger char found\n",
5086 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5088 *pstring = ctx.as_string.data;
5090 o_free_unsafe(&ctx.as_string);
5092 return ctx.list_head;
5100 next = i_peek(input);
5103 /* Catch <, > before deciding whether this word is
5104 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5107 redir_fd = redirect_opt_num(&dest);
5108 if (done_word(&dest, &ctx)) {
5111 redir_style = REDIRECT_OVERWRITE;
5113 redir_style = REDIRECT_APPEND;
5114 ch = i_getch(input);
5115 nommu_addchr(&ctx.as_string, ch);
5118 else if (next == '(') {
5119 syntax_error(">(process) not supported");
5123 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5125 continue; /* back to top of while (1) */
5127 redir_fd = redirect_opt_num(&dest);
5128 if (done_word(&dest, &ctx)) {
5131 redir_style = REDIRECT_INPUT;
5133 redir_style = REDIRECT_HEREDOC;
5135 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5136 ch = i_getch(input);
5137 nommu_addchr(&ctx.as_string, ch);
5138 } else if (next == '>') {
5139 redir_style = REDIRECT_IO;
5140 ch = i_getch(input);
5141 nommu_addchr(&ctx.as_string, ch);
5144 else if (next == '(') {
5145 syntax_error("<(process) not supported");
5149 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5151 continue; /* back to top of while (1) */
5154 if (dest.o_assignment == MAYBE_ASSIGNMENT
5155 /* check that we are not in word in "a=1 2>word b=1": */
5156 && !ctx.pending_redirect
5158 /* ch is a special char and thus this word
5159 * cannot be an assignment */
5160 dest.o_assignment = NOT_ASSIGNMENT;
5165 if (dest.length == 0) {
5168 if (ch == EOF || ch == '\n')
5171 /* note: we do not add it to &ctx.as_string */
5173 nommu_addchr(&ctx.as_string, '\n');
5175 o_addQchr(&dest, ch);
5180 syntax_error("\\<eof>");
5183 o_addchr(&dest, '\\');
5184 ch = i_getch(input);
5185 nommu_addchr(&ctx.as_string, ch);
5186 o_addchr(&dest, ch);
5187 /* Example: echo Hello \2>file
5188 * we need to know that word 2 is quoted */
5192 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5193 debug_printf_parse("parse_stream parse error: "
5194 "handle_dollar returned non-0\n");
5201 ch = i_getch(input);
5203 syntax_error_unterm_ch('\'');
5206 nommu_addchr(&ctx.as_string, ch);
5209 if (dest.o_assignment == NOT_ASSIGNMENT)
5210 o_addqchr(&dest, ch);
5212 o_addchr(&dest, ch);
5217 is_in_dquote ^= 1; /* invert */
5218 if (dest.o_assignment == NOT_ASSIGNMENT)
5221 #if ENABLE_HUSH_TICK
5226 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5227 o_addchr(&dest, '`');
5231 if (add_till_backquote(&dest, input))
5234 o_addstr(&ctx.as_string, dest.data + pos);
5235 o_addchr(&ctx.as_string, '`');
5237 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5238 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5243 #if ENABLE_HUSH_CASE
5246 if (done_word(&dest, &ctx)) {
5249 done_pipe(&ctx, PIPE_SEQ);
5250 #if ENABLE_HUSH_CASE
5251 /* Eat multiple semicolons, detect
5252 * whether it means something special */
5257 ch = i_getch(input);
5258 nommu_addchr(&ctx.as_string, ch);
5259 if (ctx.ctx_res_w == RES_CASEI) {
5260 ctx.ctx_dsemicolon = 1;
5261 ctx.ctx_res_w = RES_MATCH;
5267 /* We just finished a cmd. New one may start
5268 * with an assignment */
5269 dest.o_assignment = MAYBE_ASSIGNMENT;
5272 if (done_word(&dest, &ctx)) {
5276 ch = i_getch(input);
5277 nommu_addchr(&ctx.as_string, ch);
5278 done_pipe(&ctx, PIPE_AND);
5280 done_pipe(&ctx, PIPE_BG);
5284 if (done_word(&dest, &ctx)) {
5287 #if ENABLE_HUSH_CASE
5288 if (ctx.ctx_res_w == RES_MATCH)
5289 break; /* we are in case's "word | word)" */
5291 if (next == '|') { /* || */
5292 ch = i_getch(input);
5293 nommu_addchr(&ctx.as_string, ch);
5294 done_pipe(&ctx, PIPE_OR);
5296 /* we could pick up a file descriptor choice here
5297 * with redirect_opt_num(), but bash doesn't do it.
5298 * "echo foo 2| cat" yields "foo 2". */
5303 #if ENABLE_HUSH_CASE
5304 /* "case... in [(]word)..." - skip '(' */
5305 if (ctx.ctx_res_w == RES_MATCH
5306 && ctx.command->argv == NULL /* not (word|(... */
5307 && dest.length == 0 /* not word(... */
5308 && dest.o_quoted == 0 /* not ""(... */
5313 #if ENABLE_HUSH_FUNCTIONS
5314 if (dest.length != 0 /* not just () but word() */
5315 && dest.o_quoted == 0 /* not a"b"c() */
5316 && ctx.command->argv == NULL /* it's the first word */
5317 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5318 && i_peek(input) == ')'
5319 && !match_reserved_word(&dest)
5321 bb_error_msg("seems like a function definition");
5323 //if !BB_MMU o_addchr(&ctx.as_string...
5325 //TODO: do it properly.
5326 ch = i_getch(input);
5327 } while (ch == ' ' || ch == '\n');
5329 syntax_error("was expecting {");
5332 ch = 'F'; /* magic value */
5336 if (parse_group(&dest, &ctx, input, ch) != 0) {
5341 #if ENABLE_HUSH_CASE
5342 if (ctx.ctx_res_w == RES_MATCH)
5346 /* proper use of this character is caught by end_trigger:
5347 * if we see {, we call parse_group(..., end_trigger='}')
5348 * and it will match } earlier (not here). */
5349 syntax_error("unexpected } or )");
5353 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5359 struct parse_context *pctx;
5360 IF_HAS_KEYWORDS(struct parse_context *p2;)
5362 /* Clean up allocated tree.
5363 * Samples for finding leaks on syntax error recovery path.
5364 * Run them from interactive shell, watch pmap `pidof hush`.
5365 * while if false; then false; fi do break; done
5367 * while if false; then false; fi; do break; fi
5368 * Samples to catch leaks at execution:
5369 * while if (true | {true;}); then echo ok; fi; do break; done
5370 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5374 /* Update pipe/command counts,
5375 * otherwise freeing may miss some */
5376 done_pipe(pctx, PIPE_SEQ);
5377 debug_printf_clean("freeing list %p from ctx %p\n",
5378 pctx->list_head, pctx);
5379 debug_print_tree(pctx->list_head, 0);
5380 free_pipe_list(pctx->list_head, 0);
5381 debug_printf_clean("freed list %p\n", pctx->list_head);
5383 o_free_unsafe(&pctx->as_string);
5385 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5389 IF_HAS_KEYWORDS(pctx = p2;)
5390 } while (HAS_KEYWORDS && pctx);
5391 /* Free text, clear all dest fields */
5393 /* If we are not in top-level parse, we return,
5394 * our caller will propagate error.
5396 if (end_trigger != ';') {
5403 /* Discard cached input, force prompt */
5405 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5410 /* Executing from string: eval, sh -c '...'
5411 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5412 * end_trigger controls how often we stop parsing
5413 * NUL: parse all, execute, return
5414 * ';': parse till ';' or newline, execute, repeat till EOF
5416 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5419 struct pipe *pipe_list;
5421 pipe_list = parse_stream(NULL, inp, end_trigger);
5422 if (!pipe_list) /* EOF */
5424 debug_print_tree(pipe_list, 0);
5425 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5426 run_and_free_list(pipe_list);
5430 static void parse_and_run_string(const char *s)
5432 struct in_str input;
5433 setup_string_in_str(&input, s);
5434 parse_and_run_stream(&input, '\0');
5437 static void parse_and_run_file(FILE *f)
5439 struct in_str input;
5440 setup_file_in_str(&input, f);
5441 parse_and_run_stream(&input, ';');
5444 /* Called a few times only (or even once if "sh -c") */
5445 static void block_signals(int second_time)
5450 mask = (1 << SIGQUIT);
5451 if (G_interactive_fd) {
5455 //TODO | (1 << SIGHUP)
5457 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5462 G.non_DFL_mask = mask;
5465 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5469 sigaddset(&G.blocked_set, sig);
5473 sigdelset(&G.blocked_set, SIGCHLD);
5475 sigprocmask(SIG_SETMASK, &G.blocked_set,
5476 second_time ? NULL : &G.inherited_set);
5477 /* POSIX allows shell to re-enable SIGCHLD
5478 * even if it was SIG_IGN on entry */
5479 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5481 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5486 static void maybe_set_to_sigexit(int sig)
5488 void (*handler)(int);
5489 /* non_DFL_mask'ed signals are, well, masked,
5490 * no need to set handler for them.
5492 if (!((G.non_DFL_mask >> sig) & 1)) {
5493 handler = signal(sig, sigexit);
5494 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5495 signal(sig, handler);
5498 /* Set handlers to restore tty pgrp and exit */
5499 static void set_fatal_handlers(void)
5501 /* We _must_ restore tty pgrp on fatal signals */
5503 maybe_set_to_sigexit(SIGILL );
5504 maybe_set_to_sigexit(SIGFPE );
5505 maybe_set_to_sigexit(SIGBUS );
5506 maybe_set_to_sigexit(SIGSEGV);
5507 maybe_set_to_sigexit(SIGTRAP);
5508 } /* else: hush is perfect. what SEGV? */
5509 maybe_set_to_sigexit(SIGABRT);
5510 /* bash 3.2 seems to handle these just like 'fatal' ones */
5511 maybe_set_to_sigexit(SIGPIPE);
5512 maybe_set_to_sigexit(SIGALRM);
5513 //TODO: disable and move down when proper SIGHUP handling is added
5514 maybe_set_to_sigexit(SIGHUP );
5515 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5516 * if we aren't interactive... but in this case
5517 * we never want to restore pgrp on exit, and this fn is not called */
5518 /*maybe_set_to_sigexit(SIGTERM);*/
5519 /*maybe_set_to_sigexit(SIGINT );*/
5523 static int set_mode(const char cstate, const char mode)
5525 int state = (cstate == '-' ? 1 : 0);
5527 case 'n': G.fake_mode = state; break;
5528 case 'x': /*G.debug_mode = state;*/ break;
5529 default: return EXIT_FAILURE;
5531 return EXIT_SUCCESS;
5534 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5535 int hush_main(int argc, char **argv)
5537 static const struct variable const_shell_ver = {
5539 .varstr = (char*)hush_version_str,
5540 .max_len = 1, /* 0 can provoke free(name) */
5544 int signal_mask_is_inited = 0;
5547 struct variable *cur_var;
5550 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5551 G.last_exitcode = EXIT_SUCCESS;
5553 G.argv0_for_re_execing = argv[0];
5555 /* Deal with HUSH_VERSION */
5556 G.shell_ver = const_shell_ver; /* copying struct here */
5557 G.top_var = &G.shell_ver;
5558 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5559 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5560 /* Initialize our shell local variables with the values
5561 * currently living in the environment */
5562 cur_var = G.top_var;
5565 char *value = strchr(*e, '=');
5566 if (value) { /* paranoia */
5567 cur_var->next = xzalloc(sizeof(*cur_var));
5568 cur_var = cur_var->next;
5569 cur_var->varstr = *e;
5570 cur_var->max_len = strlen(*e);
5571 cur_var->flg_export = 1;
5575 debug_printf_env("putenv '%s'\n", hush_version_str);
5576 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5577 #if ENABLE_FEATURE_EDITING
5578 G.line_input_state = new_line_input_t(FOR_SHELL);
5580 G.global_argc = argc;
5581 G.global_argv = argv;
5582 /* Initialize some more globals to non-zero values */
5584 #if ENABLE_HUSH_INTERACTIVE
5585 if (ENABLE_FEATURE_EDITING)
5586 cmdedit_set_initial_prompt();
5590 /* Shell is non-interactive at first. We need to call
5591 * block_signals(0) if we are going to execute "sh <script>",
5592 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5593 * If we later decide that we are interactive, we run block_signals(0)
5594 * (or re-run block_signals(1) if we ran block_signals(0) before)
5595 * in order to intercept (more) signals.
5599 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5601 opt = getopt(argc, argv, "c:xins"
5611 G.root_pid = getpid();
5612 G.global_argv = argv + optind;
5613 if (!argv[optind]) {
5614 /* -c 'script' (no params): prevent empty $0 */
5615 *--G.global_argv = argv[0];
5617 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5618 G.global_argc = argc - optind;
5619 block_signals(0); /* 0: called 1st time */
5620 parse_and_run_string(optarg);
5623 /* Well, we cannot just declare interactiveness,
5624 * we have to have some stuff (ctty, etc) */
5625 /* G_interactive_fd++; */
5628 /* "-s" means "read from stdin", but this is how we always
5629 * operate, so simply do nothing here. */
5632 case '<': /* "big heredoc" support */
5633 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5636 G.root_pid = bb_strtou(optarg, &optarg, 16);
5638 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5640 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5641 # if ENABLE_HUSH_LOOPS
5643 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5648 set_local_var(xstrdup(optarg), 0, opt == 'R');
5653 if (!set_mode('-', opt))
5657 fprintf(stderr, "Usage: sh [FILE]...\n"
5658 " or: sh -c command [args]...\n\n");
5664 } /* option parsing loop */
5667 G.root_pid = getpid();
5669 /* If we are login shell... */
5670 if (argv[0] && argv[0][0] == '-') {
5672 /* XXX what should argv be while sourcing /etc/profile? */
5673 debug_printf("sourcing /etc/profile\n");
5674 input = fopen_for_read("/etc/profile");
5675 if (input != NULL) {
5676 close_on_exec_on(fileno(input));
5677 block_signals(0); /* 0: called 1st time */
5678 signal_mask_is_inited = 1;
5679 parse_and_run_file(input);
5682 /* bash: after sourcing /etc/profile,
5683 * tries to source (in the given order):
5684 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5685 * stopping of first found. --noprofile turns this off.
5686 * bash also sources ~/.bash_logout on exit.
5687 * If called as sh, skips .bash_XXX files.
5694 * "bash <script>" (which is never interactive (unless -i?))
5695 * sources $BASH_ENV here (without scanning $PATH).
5696 * If called as sh, does the same but with $ENV.
5698 debug_printf("running script '%s'\n", argv[optind]);
5699 G.global_argv = argv + optind;
5700 G.global_argc = argc - optind;
5701 input = xfopen_for_read(argv[optind]);
5702 close_on_exec_on(fileno(input));
5703 if (!signal_mask_is_inited)
5704 block_signals(0); /* 0: called 1st time */
5705 parse_and_run_file(input);
5706 #if ENABLE_FEATURE_CLEAN_UP
5712 /* Up to here, shell was non-interactive. Now it may become one.
5713 * NB: don't forget to (re)run block_signals(0/1) as needed.
5716 /* A shell is interactive if the '-i' flag was given, or if all of
5717 * the following conditions are met:
5719 * no arguments remaining or the -s flag given
5720 * standard input is a terminal
5721 * standard output is a terminal
5722 * Refer to Posix.2, the description of the 'sh' utility.
5725 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5726 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5727 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5728 //TODO: "interactive" and "have job control" are two different things.
5729 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5730 //should stay on! Currently, we mix these into one.
5731 if (G.saved_tty_pgrp >= 0) {
5732 /* try to dup stdin to high fd#, >= 255 */
5733 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5734 if (G_interactive_fd < 0) {
5735 /* try to dup to any fd */
5736 G_interactive_fd = dup(STDIN_FILENO);
5737 if (G_interactive_fd < 0)
5739 G_interactive_fd = 0;
5741 // TODO: track & disallow any attempts of user
5742 // to (inadvertently) close/redirect it
5745 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5746 if (G_interactive_fd) {
5749 /* We are indeed interactive shell, and we will perform
5750 * job control. Setting up for that. */
5752 close_on_exec_on(G_interactive_fd);
5753 /* If we were run as 'hush &', sleep until we are
5754 * in the foreground (tty pgrp == our pgrp).
5755 * If we get started under a job aware app (like bash),
5756 * make sure we are now in charge so we don't fight over
5757 * who gets the foreground */
5759 shell_pgrp = getpgrp();
5760 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5761 if (G.saved_tty_pgrp == shell_pgrp)
5763 /* send TTIN to ourself (should stop us) */
5764 kill(- shell_pgrp, SIGTTIN);
5766 /* Block some signals */
5767 block_signals(signal_mask_is_inited);
5768 /* Set other signals to restore saved_tty_pgrp */
5769 set_fatal_handlers();
5770 /* Put ourselves in our own process group */
5771 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5772 /* Grab control of the terminal */
5773 tcsetpgrp(G_interactive_fd, getpid());
5774 /* -1 is special - makes xfuncs longjmp, not exit
5775 * (we reset die_sleep = 0 whereever we [v]fork) */
5776 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5777 if (setjmp(die_jmp)) {
5778 /* xfunc has failed! die die die */
5779 /* no EXIT traps, this is an escape hatch! */
5781 hush_exit(xfunc_error_retval);
5783 } else if (!signal_mask_is_inited) {
5784 block_signals(0); /* 0: called 1st time */
5785 } /* else: block_signals(0) was done before */
5786 #elif ENABLE_HUSH_INTERACTIVE
5787 /* No job control compiled in, only prompt/line editing */
5788 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5789 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5790 if (G_interactive_fd < 0) {
5791 /* try to dup to any fd */
5792 G_interactive_fd = dup(STDIN_FILENO);
5793 if (G_interactive_fd < 0)
5795 G_interactive_fd = 0;
5798 if (G_interactive_fd) {
5799 close_on_exec_on(G_interactive_fd);
5800 block_signals(signal_mask_is_inited);
5801 } else if (!signal_mask_is_inited) {
5805 /* We have interactiveness code disabled */
5806 if (!signal_mask_is_inited) {
5811 * if interactive but not a login shell, sources ~/.bashrc
5812 * (--norc turns this off, --rcfile <file> overrides)
5815 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5816 printf("\n\n%s hush - the humble shell\n", bb_banner);
5817 printf("Enter 'help' for a list of built-in commands.\n\n");
5820 parse_and_run_file(stdin);
5823 #if ENABLE_FEATURE_CLEAN_UP
5824 if (G.cwd != bb_msg_unknown)
5826 cur_var = G.top_var->next;
5828 struct variable *tmp = cur_var;
5829 if (!cur_var->max_len)
5830 free(cur_var->varstr);
5831 cur_var = cur_var->next;
5835 hush_exit(G.last_exitcode);
5840 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5841 int lash_main(int argc, char **argv)
5843 //bb_error_msg("lash is deprecated, please use hush instead");
5844 return hush_main(argc, argv);
5852 static int builtin_trap(char **argv)
5859 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5863 /* No args: print all trapped. This isn't 100% correct as we
5864 * should be escaping the cmd so that it can be pasted back in
5866 for (i = 0; i < NSIG; ++i)
5868 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5869 return EXIT_SUCCESS;
5874 /* If first arg is decimal: reset all specified signals */
5875 sig = bb_strtou(*argv, NULL, 10);
5881 sig = get_signum(*argv++);
5882 if (sig < 0 || sig >= NSIG) {
5884 /* Mimic bash message exactly */
5885 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5890 G.traps[sig] = xstrdup(new_cmd);
5892 debug_printf("trap: setting SIG%s (%i) to '%s'",
5893 get_signame(sig), sig, G.traps[sig]);
5895 /* There is no signal for 0 (EXIT) */
5900 sigaddset(&G.blocked_set, sig);
5902 /* There was a trap handler, we are removing it
5903 * (if sig has non-DFL handling,
5904 * we don't need to do anything) */
5905 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5907 sigdelset(&G.blocked_set, sig);
5909 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5914 /* First arg is "-": reset all specified to default */
5915 /* First arg is "": ignore all specified */
5916 /* Everything else: execute first arg upon signal */
5918 bb_error_msg("trap: invalid arguments");
5919 return EXIT_FAILURE;
5921 if (NOT_LONE_DASH(*argv))
5927 static int builtin_true(char **argv UNUSED_PARAM)
5932 static int builtin_test(char **argv)
5939 return test_main(argc, argv - argc);
5942 static int builtin_echo(char **argv)
5949 return echo_main(argc, argv - argc);
5952 static int builtin_eval(char **argv)
5954 int rcode = EXIT_SUCCESS;
5957 char *str = expand_strvec_to_string(argv);
5959 * eval "echo Hi; done" ("done" is syntax error):
5960 * "echo Hi" will not execute too.
5962 parse_and_run_string(str);
5964 rcode = G.last_exitcode;
5969 static int builtin_cd(char **argv)
5971 const char *newdir = argv[1];
5972 if (newdir == NULL) {
5973 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5974 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5976 newdir = getenv("HOME") ? : "/";
5978 if (chdir(newdir)) {
5979 /* Mimic bash message exactly */
5980 bb_perror_msg("cd: %s", newdir);
5981 return EXIT_FAILURE;
5984 return EXIT_SUCCESS;
5987 static int builtin_exec(char **argv)
5989 if (*++argv == NULL)
5990 return EXIT_SUCCESS; /* bash does this */
5995 // FIXME: if exec fails, bash does NOT exit! We do...
5996 pseudo_exec_argv(&dummy, argv, 0, NULL);
6001 static int builtin_exit(char **argv)
6003 debug_printf_exec("%s()\n", __func__);
6004 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6005 //puts("exit"); /* bash does it */
6006 // TODO: warn if we have background jobs: "There are stopped jobs"
6007 // On second consecutive 'exit', exit anyway.
6008 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6010 /* note: EXIT trap is run by hush_exit */
6011 if (*++argv == NULL)
6012 hush_exit(G.last_exitcode);
6013 /* mimic bash: exit 123abc == exit 255 + error msg */
6014 xfunc_error_retval = 255;
6015 /* bash: exit -2 == exit 254, no error msg */
6016 hush_exit(xatoi(*argv) & 0xff);
6019 static int builtin_export(char **argv)
6021 if (*++argv == NULL) {
6023 // ash emits: export VAR='VAL'
6024 // bash: declare -x VAR="VAL"
6025 // (both also escape as needed (quotes, $, etc))
6030 return EXIT_SUCCESS;
6037 value = strchr(name, '=');
6039 /* They are exporting something without a =VALUE */
6040 struct variable *var;
6042 var = get_local_var(name);
6044 var->flg_export = 1;
6045 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6046 putenv(var->varstr);
6048 /* bash does not return an error when trying to export
6049 * an undefined variable. Do likewise. */
6052 set_local_var(xstrdup(name), 1, 0);
6055 return EXIT_SUCCESS;
6059 /* built-in 'fg' and 'bg' handler */
6060 static int builtin_fg_bg(char **argv)
6065 if (!G_interactive_fd)
6066 return EXIT_FAILURE;
6067 /* If they gave us no args, assume they want the last backgrounded task */
6069 for (pi = G.job_list; pi; pi = pi->next) {
6070 if (pi->jobid == G.last_jobid) {
6074 bb_error_msg("%s: no current job", argv[0]);
6075 return EXIT_FAILURE;
6077 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6078 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6079 return EXIT_FAILURE;
6081 for (pi = G.job_list; pi; pi = pi->next) {
6082 if (pi->jobid == jobnum) {
6086 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6087 return EXIT_FAILURE;
6089 // TODO: bash prints a string representation
6090 // of job being foregrounded (like "sleep 1 | cat")
6091 if (argv[0][0] == 'f') {
6092 /* Put the job into the foreground. */
6093 tcsetpgrp(G_interactive_fd, pi->pgrp);
6096 /* Restart the processes in the job */
6097 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6098 for (i = 0; i < pi->num_cmds; i++) {
6099 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6100 pi->cmds[i].is_stopped = 0;
6102 pi->stopped_cmds = 0;
6104 i = kill(- pi->pgrp, SIGCONT);
6106 if (errno == ESRCH) {
6107 delete_finished_bg_job(pi);
6108 return EXIT_SUCCESS;
6110 bb_perror_msg("kill (SIGCONT)");
6113 if (argv[0][0] == 'f') {
6115 return checkjobs_and_fg_shell(pi);
6117 return EXIT_SUCCESS;
6121 #if ENABLE_HUSH_HELP
6122 static int builtin_help(char **argv UNUSED_PARAM)
6124 const struct built_in_command *x;
6127 "Built-in commands:\n"
6128 "------------------\n");
6129 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6130 printf("%s\t%s\n", x->cmd, x->descr);
6133 return EXIT_SUCCESS;
6138 static int builtin_jobs(char **argv UNUSED_PARAM)
6141 const char *status_string;
6143 for (job = G.job_list; job; job = job->next) {
6144 if (job->alive_cmds == job->stopped_cmds)
6145 status_string = "Stopped";
6147 status_string = "Running";
6149 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6151 return EXIT_SUCCESS;
6156 static int builtin_memleak(char **argv UNUSED_PARAM)
6161 /* Crude attempt to find where "free memory" starts,
6162 * sans fragmentation. */
6164 l = (unsigned long)p;
6167 if (l < (unsigned long)p) l = (unsigned long)p;
6170 if (!G.memleak_value)
6171 G.memleak_value = l;
6173 l -= G.memleak_value;
6180 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6185 static int builtin_pwd(char **argv UNUSED_PARAM)
6188 return EXIT_SUCCESS;
6191 static int builtin_read(char **argv)
6194 const char *name = "REPLY";
6198 if (!is_well_formed_var_name(name, '\0')) {
6199 /* Mimic bash message */
6200 bb_error_msg("read: '%s': not a valid identifier", name);
6205 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6206 return set_local_var(string, 0, 0);
6209 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6210 * built-in 'set' handler
6212 * set [-abCefhmnuvx] [-o option] [argument...]
6213 * set [+abCefhmnuvx] [+o option] [argument...]
6214 * set -- [argument...]
6217 * Implementations shall support the options in both their hyphen and
6218 * plus-sign forms. These options can also be specified as options to sh.
6220 * Write out all variables and their values: set
6221 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6222 * Turn on the -x and -v options: set -xv
6223 * Unset all positional parameters: set --
6224 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6225 * Set the positional parameters to the expansion of x, even if x expands
6226 * with a leading '-' or '+': set -- $x
6228 * So far, we only support "set -- [argument...]" and some of the short names.
6230 static int builtin_set(char **argv)
6233 char **pp, **g_argv;
6234 char *arg = *++argv;
6238 for (e = G.top_var; e; e = e->next)
6240 return EXIT_SUCCESS;
6244 if (!strcmp(arg, "--")) {
6249 if (arg[0] == '+' || arg[0] == '-') {
6250 for (n = 1; arg[n]; ++n)
6251 if (set_mode(arg[0], arg[n]))
6257 } while ((arg = *++argv) != NULL);
6258 /* Now argv[0] is 1st argument */
6260 /* Only reset global_argv if we didn't process anything */
6262 return EXIT_SUCCESS;
6265 /* NB: G.global_argv[0] ($0) is never freed/changed */
6266 g_argv = G.global_argv;
6267 if (G.global_args_malloced) {
6273 G.global_args_malloced = 1;
6274 pp = xzalloc(sizeof(pp[0]) * 2);
6275 pp[0] = g_argv[0]; /* retain $0 */
6278 /* This realloc's G.global_argv */
6279 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6286 return EXIT_SUCCESS;
6288 /* Nothing known, so abort */
6290 bb_error_msg("set: %s: invalid option", arg);
6291 return EXIT_FAILURE;
6294 static int builtin_shift(char **argv)
6300 if (n >= 0 && n < G.global_argc) {
6301 if (G.global_args_malloced) {
6304 free(G.global_argv[m++]);
6307 memmove(&G.global_argv[1], &G.global_argv[n+1],
6308 G.global_argc * sizeof(G.global_argv[0]));
6309 return EXIT_SUCCESS;
6311 return EXIT_FAILURE;
6314 static int builtin_source(char **argv)
6318 if (*++argv == NULL)
6319 return EXIT_FAILURE;
6321 /* XXX search through $PATH is missing */
6322 input = fopen_or_warn(*argv, "r");
6324 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6325 return EXIT_FAILURE;
6327 close_on_exec_on(fileno(input));
6329 /* Now run the file */
6331 /* XXX argv and argc are broken; need to save old G.global_argv
6332 * (pointer only is OK!) on this stack frame,
6333 * set G.global_argv=argv+1, recurse, and restore. */
6334 parse_and_run_file(input);
6336 return G.last_exitcode;
6339 static int builtin_umask(char **argv)
6342 const char *arg = argv[1];
6344 //TODO: umask may take chmod-like symbolic masks
6345 new_umask = bb_strtou(arg, NULL, 8);
6347 //Message? bash examples:
6348 //bash: umask: 'q': invalid symbolic mode operator
6349 //bash: umask: 999: octal number out of range
6350 return EXIT_FAILURE;
6353 new_umask = umask(0);
6354 printf("%.3o\n", (unsigned) new_umask);
6355 /* fall through and restore new_umask which we set to 0 */
6358 return EXIT_SUCCESS;
6361 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6362 static int builtin_unset(char **argv)
6368 return EXIT_SUCCESS;
6371 if (argv[0][0] == '-') {
6372 switch (argv[0][1]) {
6378 bb_error_msg("unset: %s: invalid option", *argv);
6379 return EXIT_FAILURE;
6381 //TODO: disallow "unset -vf ..." too
6388 if (unset_local_var(*argv)) {
6389 /* unset <nonexistent_var> doesn't fail.
6390 * Error is when one tries to unset RO var.
6391 * Message was printed by unset_local_var. */
6395 #if ENABLE_HUSH_FUNCTIONS
6397 unset_local_func(*argv);
6405 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6406 static int builtin_wait(char **argv)
6408 int ret = EXIT_SUCCESS;
6411 if (*++argv == NULL) {
6412 /* Don't care about wait results */
6413 /* Note 1: must wait until there are no more children */
6414 /* Note 2: must be interruptible */
6416 * $ sleep 3 & sleep 6 & wait
6421 * $ sleep 3 & sleep 6 & wait
6425 * ^C <-- after ~4 sec from keyboard
6428 sigaddset(&G.blocked_set, SIGCHLD);
6429 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6432 if (errno == ECHILD)
6434 /* Wait for SIGCHLD or any other signal of interest */
6435 /* sigtimedwait with infinite timeout: */
6436 sig = sigwaitinfo(&G.blocked_set, NULL);
6438 sig = check_and_run_traps(sig);
6439 if (sig && sig != SIGCHLD) { /* see note 2 */
6445 sigdelset(&G.blocked_set, SIGCHLD);
6446 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6450 /* This is probably buggy wrt interruptible-ness */
6452 pid_t pid = bb_strtou(*argv, NULL, 10);
6454 /* mimic bash message */
6455 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6456 return EXIT_FAILURE;
6458 if (waitpid(pid, &status, 0) == pid) {
6459 if (WIFSIGNALED(status))
6460 ret = 128 + WTERMSIG(status);
6461 else if (WIFEXITED(status))
6462 ret = WEXITSTATUS(status);
6466 bb_perror_msg("wait %s", *argv);
6475 #if ENABLE_HUSH_LOOPS
6476 static int builtin_break(char **argv)
6478 if (G.depth_of_loop == 0) {
6479 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6480 return EXIT_SUCCESS; /* bash compat */
6482 G.flag_break_continue++; /* BC_BREAK = 1 */
6483 G.depth_break_continue = 1;
6485 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6486 if (errno || !G.depth_break_continue || argv[2]) {
6487 bb_error_msg("%s: bad arguments", argv[0]);
6488 G.flag_break_continue = BC_BREAK;
6489 G.depth_break_continue = UINT_MAX;
6492 if (G.depth_of_loop < G.depth_break_continue)
6493 G.depth_break_continue = G.depth_of_loop;
6494 return EXIT_SUCCESS;
6497 static int builtin_continue(char **argv)
6499 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6500 return builtin_break(argv);