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 1
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,
348 /* otherwise, rd_fd is redirected to rd_dup */
350 HEREDOC_SKIPTABS = 1,
356 pid_t pid; /* 0 if exited */
357 int assignment_cnt; /* how many argv[i] are assignments? */
358 smallint is_stopped; /* is the command currently running? */
359 smallint grp_type; /* GRP_xxx */
360 struct pipe *group; /* if non-NULL, this "command" is { list },
361 * ( list ), or a compound statement */
363 char *group_as_string;
365 char **argv; /* command name and arguments */
366 struct redir_struct *redirects; /* I/O redirections */
368 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
369 * and on execution these are substituted with their values.
370 * Substitution can make _several_ words out of one argv[n]!
371 * Example: argv[0]=='.^C*^C.' here: echo .$*.
372 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
375 #define GRP_SUBSHELL 1
376 #if ENABLE_HUSH_FUNCTIONS
377 # define GRP_FUNCTION 2
382 int num_cmds; /* total number of commands in pipe */
383 int alive_cmds; /* number of commands running (not exited) */
384 int stopped_cmds; /* number of commands alive, but stopped */
386 int jobid; /* job number */
387 pid_t pgrp; /* process group ID for the job */
388 char *cmdtext; /* name of job */
390 struct command *cmds; /* array of commands in pipe */
391 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
392 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
393 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
395 typedef enum pipe_style {
402 /* This holds pointers to the various results of parsing */
403 struct parse_context {
404 /* linked list of pipes */
405 struct pipe *list_head;
406 /* last pipe (being constructed right now) */
408 /* last command in pipe (being constructed right now) */
409 struct command *command;
410 /* last redirect in command->redirects list */
411 struct redir_struct *pending_redirect;
417 smallint ctx_inverted; /* "! cmd | cmd" */
419 smallint ctx_dsemicolon; /* ";;" seen */
421 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
423 /* group we are enclosed in:
424 * example: "if pipe1; pipe2; then pipe3; fi"
425 * when we see "if" or "then", we malloc and copy current context,
426 * and make ->stack point to it. then we parse pipeN.
427 * when closing "then" / fi" / whatever is found,
428 * we move list_head into ->stack->command->group,
429 * copy ->stack into current context, and delete ->stack.
430 * (parsing of { list } and ( list ) doesn't use this method)
432 struct parse_context *stack;
436 /* On program start, environ points to initial environment.
437 * putenv adds new pointers into it, unsetenv removes them.
438 * Neither of these (de)allocates the strings.
439 * setenv allocates new strings in malloc space and does putenv,
440 * and thus setenv is unusable (leaky) for shell's purposes */
441 #define setenv(...) setenv_is_leaky_dont_use()
443 struct variable *next;
444 char *varstr; /* points to "name=" portion */
445 int max_len; /* if > 0, name is part of initial env; else name is malloced */
446 smallint flg_export; /* putenv should be done on this var */
447 smallint flg_read_only;
456 struct function *next;
462 /* "Globals" within this file */
463 /* Sorted roughly by size (smaller offsets == smaller code) */
465 #if ENABLE_HUSH_INTERACTIVE
466 /* 'interactive_fd' is a fd# open to ctty, if we have one
467 * _AND_ if we decided to act interactively */
471 #define G_interactive_fd (G.interactive_fd)
473 #define G_interactive_fd 0
475 #if ENABLE_FEATURE_EDITING
476 line_input_t *line_input_state;
482 pid_t saved_tty_pgrp;
484 struct pipe *job_list;
485 struct pipe *toplevel_list;
486 //// smallint ctrl_z_flag;
488 smallint flag_SIGINT;
489 #if ENABLE_HUSH_LOOPS
490 smallint flag_break_continue;
493 smallint exiting; /* used to prevent EXIT trap recursion */
494 /* These four support $?, $#, and $1 */
495 smalluint last_exitcode;
496 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
497 smalluint global_args_malloced;
498 /* how many non-NULL argv's we have. NB: $# + 1 */
502 char *argv0_for_re_execing;
503 char **argv_from_re_execing;
505 #if ENABLE_HUSH_LOOPS
506 unsigned depth_break_continue;
507 unsigned depth_of_loop;
511 struct variable *top_var; /* = &G.shell_ver (set in main()) */
512 struct variable shell_ver;
513 struct function *top_func;
514 /* Signal and trap handling */
515 // unsigned count_SIGCHLD;
516 // unsigned handled_SIGCHLD;
517 /* which signals have non-DFL handler (even with no traps set)? */
518 unsigned non_DFL_mask;
519 char **traps; /* char *traps[NSIG] */
520 sigset_t blocked_set;
521 sigset_t inherited_set;
523 unsigned long memleak_value;
525 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
526 #if ENABLE_FEATURE_SH_STANDALONE
527 struct nofork_save_area nofork_save;
530 sigjmp_buf toplevel_jb;
533 #define G (*ptr_to_globals)
534 /* Not #defining name to G.name - this quickly gets unwieldy
535 * (too many defines). Also, I actually prefer to see when a variable
536 * is global, thus "G." prefix is a useful hint */
537 #define INIT_G() do { \
538 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
542 /* Function prototypes for builtins */
543 static int builtin_cd(char **argv);
544 static int builtin_echo(char **argv);
545 static int builtin_eval(char **argv);
546 static int builtin_exec(char **argv);
547 static int builtin_exit(char **argv);
548 static int builtin_export(char **argv);
550 static int builtin_fg_bg(char **argv);
551 static int builtin_jobs(char **argv);
554 static int builtin_help(char **argv);
557 static int builtin_memleak(char **argv);
559 static int builtin_pwd(char **argv);
560 static int builtin_read(char **argv);
561 static int builtin_set(char **argv);
562 static int builtin_shift(char **argv);
563 static int builtin_source(char **argv);
564 static int builtin_test(char **argv);
565 static int builtin_trap(char **argv);
566 static int builtin_true(char **argv);
567 static int builtin_umask(char **argv);
568 static int builtin_unset(char **argv);
569 static int builtin_wait(char **argv);
570 #if ENABLE_HUSH_LOOPS
571 static int builtin_break(char **argv);
572 static int builtin_continue(char **argv);
575 /* Table of built-in functions. They can be forked or not, depending on
576 * context: within pipes, they fork. As simple commands, they do not.
577 * When used in non-forking context, they can change global variables
578 * in the parent shell process. If forked, of course they cannot.
579 * For example, 'unset foo | whatever' will parse and run, but foo will
580 * still be set at the end. */
581 struct built_in_command {
583 int (*function)(char **argv);
586 #define BLTIN(cmd, func, help) { cmd, func, help }
588 #define BLTIN(cmd, func, help) { cmd, func }
592 /* For now, echo and test are unconditionally enabled.
593 * Maybe make it configurable? */
594 static const struct built_in_command bltins[] = {
595 BLTIN("." , builtin_source , "Run commands in a file"),
596 BLTIN(":" , builtin_true , "No-op"),
597 BLTIN("[" , builtin_test , "Test condition"),
599 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
601 #if ENABLE_HUSH_LOOPS
602 BLTIN("break" , builtin_break , "Exit from a loop"),
604 BLTIN("cd" , builtin_cd , "Change directory"),
605 #if ENABLE_HUSH_LOOPS
606 BLTIN("continue", builtin_continue, "Start new loop iteration"),
608 BLTIN("echo" , builtin_echo , "Write to stdout"),
609 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
610 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
611 BLTIN("exit" , builtin_exit , "Exit"),
612 BLTIN("export" , builtin_export , "Set environment variable"),
614 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
617 BLTIN("help" , builtin_help , "List shell built-in commands"),
620 BLTIN("jobs" , builtin_jobs , "List active jobs"),
623 BLTIN("memleak" , builtin_memleak , "Debug tool"),
625 BLTIN("pwd" , builtin_pwd , "Print current directory"),
626 BLTIN("read" , builtin_read , "Input environment variable"),
627 // BLTIN("return" , builtin_return , "Return from a function"),
628 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
629 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
630 BLTIN("test" , builtin_test , "Test condition"),
631 BLTIN("trap" , builtin_trap , "Trap signals"),
632 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
633 BLTIN("umask" , builtin_umask , "Set file creation mask"),
634 BLTIN("unset" , builtin_unset , "Unset environment variable"),
635 BLTIN("wait" , builtin_wait , "Wait for process"),
639 /* Leak hunting. Use hush_leaktool.sh for post-processing.
642 static void *xxmalloc(int lineno, size_t size)
644 void *ptr = xmalloc((size + 0xff) & ~0xff);
645 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
648 static void *xxrealloc(int lineno, void *ptr, size_t size)
650 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
651 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
654 static char *xxstrdup(int lineno, const char *str)
656 char *ptr = xstrdup(str);
657 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
660 static void xxfree(void *ptr)
662 fdprintf(2, "free %p\n", ptr);
665 #define xmalloc(s) xxmalloc(__LINE__, s)
666 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
667 #define xstrdup(s) xxstrdup(__LINE__, s)
668 #define free(p) xxfree(p)
672 /* Syntax and runtime errors. They always abort scripts.
673 * In interactive use they usually discard unparsed and/or unexecuted commands
674 * and return to the prompt.
675 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
678 # define die_if_script(lineno, fmt...) die_if_script(fmt)
679 # define syntax_error(lineno, msg) syntax_error(msg)
680 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
681 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
682 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
685 static void die_if_script(unsigned lineno, const char *fmt, ...)
690 bb_error_msg("hush.c:%u", lineno);
693 bb_verror_msg(fmt, p, NULL);
695 if (!G_interactive_fd)
699 static void syntax_error(unsigned lineno, const char *msg)
702 die_if_script(lineno, "syntax error: %s", msg);
704 die_if_script(lineno, "syntax error", NULL);
707 static void syntax_error_at(unsigned lineno, const char *msg)
709 die_if_script(lineno, "syntax error at '%s'", msg);
712 /* It so happens that all such cases are totally fatal
713 * even if shell is interactive: EOF while looking for closing
714 * delimiter. There is nowhere to read stuff from after that,
715 * it's EOF! The only choice is to terminate.
717 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
718 static void syntax_error_unterm_ch(unsigned lineno, char ch)
723 die_if_script(lineno, "syntax error: unterminated %s", msg);
727 static void syntax_error_unterm_str(unsigned lineno, const char *s)
729 die_if_script(lineno, "syntax error: unterminated %s", s);
733 # undef die_if_script
735 # undef syntax_error_at
736 # undef syntax_error_unterm_ch
737 # undef syntax_error_unterm_str
739 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
740 # define syntax_error(msg) syntax_error(__LINE__, msg)
741 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
742 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
743 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
749 static int glob_needed(const char *s)
754 if (*s == '*' || *s == '[' || *s == '?')
761 static int is_well_formed_var_name(const char *s, char terminator)
763 if (!s || !(isalpha(*s) || *s == '_'))
766 while (isalnum(*s) || *s == '_')
768 return *s == terminator;
771 /* Replace each \x with x in place, return ptr past NUL. */
772 static char *unbackslash(char *src)
778 if ((*dst++ = *src++) == '\0')
784 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
805 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
806 v[count1 + count2] = NULL;
809 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
813 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
815 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
816 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
819 #define add_strings_to_strings(strings, add, need_to_dup) \
820 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
823 static char **add_string_to_strings(char **strings, char *add)
828 return add_strings_to_strings(strings, v, /*dup:*/ 0);
831 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
833 char **ptr = add_string_to_strings(strings, add);
834 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
837 #define add_string_to_strings(strings, add) \
838 xx_add_string_to_strings(__LINE__, strings, add)
841 static void putenv_all(char **strings)
846 debug_printf_env("putenv '%s'\n", *strings);
851 static char **putenv_all_and_save_old(char **strings)
861 eq = strchr(*strings, '=');
864 v = getenv(*strings);
867 /* v points to VAL in VAR=VAL, go back to VAR */
868 v -= (eq - *strings) + 1;
869 old = add_string_to_strings(old, v);
878 static void free_strings_and_unsetenv(char **strings, int unset)
888 debug_printf_env("unsetenv '%s'\n", *v);
896 static void free_strings(char **strings)
898 free_strings_and_unsetenv(strings, 0);
902 /* Basic theory of signal handling in shell
903 * ========================================
904 * This does not describe what hush does, rather, it is current understanding
905 * what it _should_ do. If it doesn't, it's a bug.
906 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
908 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
909 * is finished or backgrounded. It is the same in interactive and
910 * non-interactive shells, and is the same regardless of whether
911 * a user trap handler is installed or a shell special one is in effect.
912 * ^C or ^Z from keyboard seem to execute "at once" because it usually
913 * backgrounds (i.e. stops) or kills all members of currently running
916 * Wait builtin in interruptible by signals for which user trap is set
917 * or by SIGINT in interactive shell.
919 * Trap handlers will execute even within trap handlers. (right?)
921 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
923 * If job control is off, backgrounded commands ("cmd &")
924 * have SIGINT, SIGQUIT set to SIG_IGN.
926 * Commands run in command substitution ("`cmd`")
927 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
929 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
930 * by the shell from its parent.
932 * Siganls which differ from SIG_DFL action
933 * (note: child (i.e., [v]forked) shell is not an interactive shell):
936 * SIGTERM (interactive): ignore
937 * SIGHUP (interactive):
938 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
939 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
940 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
941 * that all pipe members are stopped) (right?)
942 * SIGINT (interactive): wait for last pipe, ignore the rest
943 * of the command line, show prompt. NB: ^C does not send SIGINT
944 * to interactive shell while shell is waiting for a pipe,
945 * since shell is bg'ed (is not in foreground process group).
946 * (check/expand this)
947 * Example 1: this waits 5 sec, but does not execute ls:
948 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
949 * Example 2: this does not wait and does not execute ls:
950 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
951 * Example 3: this does not wait 5 sec, but executes ls:
952 * "sleep 5; ls -l" + press ^C
954 * (What happens to signals which are IGN on shell start?)
955 * (What happens with signal mask on shell start?)
957 * Implementation in hush
958 * ======================
959 * We use in-kernel pending signal mask to determine which signals were sent.
960 * We block all signals which we don't want to take action immediately,
961 * i.e. we block all signals which need to have special handling as described
962 * above, and all signals which have traps set.
963 * After each pipe execution, we extract any pending signals via sigtimedwait()
966 * unsigned non_DFL_mask: a mask of such "special" signals
967 * sigset_t blocked_set: current blocked signal set
970 * clear bit in blocked_set unless it is also in non_DFL_mask
971 * "trap 'cmd' SIGxxx":
972 * set bit in blocked_set (even if 'cmd' is '')
973 * after [v]fork, if we plan to be a shell:
974 * nothing for {} child shell (say, "true | { true; true; } | true")
975 * unset all traps if () shell.
976 * after [v]fork, if we plan to exec:
977 * POSIX says pending signal mask is cleared in child - no need to clear it.
978 * Restore blocked signal set to one inherited by shell just prior to exec.
980 * Note: as a result, we do not use signal handlers much. The only uses
981 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
982 * and to restore tty pgrp on signal-induced exit.
985 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
987 // G.count_SIGCHLD++;
990 static int check_and_run_traps(int sig)
992 static const struct timespec zero_timespec = { 0, 0 };
993 smalluint save_rcode;
999 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1004 if (G.traps && G.traps[sig]) {
1005 if (G.traps[sig][0]) {
1006 /* We have user-defined handler */
1007 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1008 save_rcode = G.last_exitcode;
1011 G.last_exitcode = save_rcode;
1012 } /* else: "" trap, ignoring signal */
1015 /* not a trap: special action */
1018 // G.count_SIGCHLD++;
1027 default: /* ignored: */
1028 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1037 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1038 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1039 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1040 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1042 /* Restores tty foreground process group, and exits.
1043 * May be called as signal handler for fatal signal
1044 * (will faithfully resend signal to itself, producing correct exit state)
1045 * or called directly with -EXITCODE.
1046 * We also call it if xfunc is exiting. */
1047 static void sigexit(int sig) NORETURN;
1048 static void sigexit(int sig)
1050 /* Disable all signals: job control, SIGPIPE, etc. */
1051 sigprocmask_allsigs(SIG_BLOCK);
1053 /* Careful: we can end up here after [v]fork. Do not restore
1054 * tty pgrp then, only top-level shell process does that */
1055 if (G_interactive_fd && getpid() == G.root_pid)
1056 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1058 /* Not a signal, just exit */
1062 kill_myself_with_sig(sig); /* does not return */
1066 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1067 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1071 /* Restores tty foreground process group, and exits. */
1072 static void hush_exit(int exitcode) NORETURN;
1073 static void hush_exit(int exitcode)
1075 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1076 /* Prevent recursion:
1077 * trap "echo Hi; exit" EXIT; exit
1079 char *argv[] = { NULL, G.traps[0], NULL };
1087 fflush(NULL); /* flush all streams */
1088 sigexit(- (exitcode & 0xff));
1095 static const char *set_cwd(void)
1097 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1098 * we must not try to free(bb_msg_unknown) */
1099 if (G.cwd == bb_msg_unknown)
1101 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1103 G.cwd = bb_msg_unknown;
1108 /* Get/check local shell variables */
1109 static struct variable *get_local_var(const char *name)
1111 struct variable *cur;
1117 for (cur = G.top_var; cur; cur = cur->next) {
1118 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1124 static const char *get_local_var_value(const char *src)
1126 struct variable *var = get_local_var(src);
1128 return strchr(var->varstr, '=') + 1;
1132 /* str holds "NAME=VAL" and is expected to be malloced.
1133 * We take ownership of it.
1137 * -1: if NAME is set, leave export status alone
1138 * if NAME is not set, do not export
1139 * flg_read_only is set only when we handle -R var=val
1142 #define set_local_var(str, flg_export, flg_read_only) \
1143 set_local_var(str, flg_export)
1145 static int set_local_var(char *str, int flg_export, int flg_read_only)
1147 struct variable *cur;
1151 value = strchr(str, '=');
1152 if (!value) { /* not expected to ever happen? */
1157 name_len = value - str + 1; /* including '=' */
1158 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1160 if (strncmp(cur->varstr, str, name_len) != 0) {
1162 /* Bail out. Note that now cur points
1163 * to last var in linked list */
1169 /* We found an existing var with this name */
1171 if (cur->flg_read_only) {
1175 bb_error_msg("%s: readonly variable", str);
1179 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1180 unsetenv(str); /* just in case */
1182 if (strcmp(cur->varstr, str) == 0) {
1187 if (cur->max_len >= strlen(str)) {
1188 /* This one is from startup env, reuse space */
1189 strcpy(cur->varstr, str);
1192 /* max_len == 0 signifies "malloced" var, which we can
1193 * (and has to) free */
1197 goto set_str_and_exp;
1200 /* Not found - create next variable struct */
1201 cur->next = xzalloc(sizeof(*cur));
1207 cur->flg_read_only = flg_read_only;
1210 if (flg_export == 1)
1211 cur->flg_export = 1;
1212 if (cur->flg_export) {
1213 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1214 return putenv(cur->varstr);
1219 static int unset_local_var(const char *name)
1221 struct variable *cur;
1222 struct variable *prev = prev; /* for gcc */
1226 return EXIT_SUCCESS;
1227 name_len = strlen(name);
1230 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1231 if (cur->flg_read_only) {
1232 bb_error_msg("%s: readonly variable", name);
1233 return EXIT_FAILURE;
1235 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1236 * is ro, and we cannot reach this code on the 1st pass */
1237 prev->next = cur->next;
1238 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1239 bb_unsetenv(cur->varstr);
1243 return EXIT_SUCCESS;
1248 return EXIT_SUCCESS;
1251 #if ENABLE_SH_MATH_SUPPORT
1252 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1253 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1254 static char *endofname(const char *name)
1262 if (!is_in_name(*p))
1268 static void arith_set_local_var(const char *name, const char *val, int flags)
1270 /* arith code doesnt malloc space, so do it for it */
1271 char *var = xasprintf("%s=%s", name, val);
1272 set_local_var(var, flags, 0);
1280 static int static_get(struct in_str *i)
1289 static int static_peek(struct in_str *i)
1294 #if ENABLE_HUSH_INTERACTIVE
1296 static void cmdedit_set_initial_prompt(void)
1298 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1299 G.PS1 = getenv("PS1");
1306 static const char* setup_prompt_string(int promptmode)
1308 const char *prompt_str;
1309 debug_printf("setup_prompt_string %d ", promptmode);
1310 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1311 /* Set up the prompt */
1312 if (promptmode == 0) { /* PS1 */
1314 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1319 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1320 debug_printf("result '%s'\n", prompt_str);
1324 static void get_user_input(struct in_str *i)
1327 const char *prompt_str;
1329 prompt_str = setup_prompt_string(i->promptmode);
1330 #if ENABLE_FEATURE_EDITING
1331 /* Enable command line editing only while a command line
1332 * is actually being read */
1335 /* buglet: SIGINT will not make new prompt to appear _at once_,
1336 * only after <Enter>. (^C will work) */
1337 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1338 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1339 check_and_run_traps(0);
1340 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1341 i->eof_flag = (r < 0);
1342 if (i->eof_flag) { /* EOF/error detected */
1343 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1344 G.user_input_buf[1] = '\0';
1349 fputs(prompt_str, stdout);
1351 G.user_input_buf[0] = r = fgetc(i->file);
1352 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1353 //do we need check_and_run_traps(0)? (maybe only if stdin)
1354 } while (G.flag_SIGINT);
1355 i->eof_flag = (r == EOF);
1357 i->p = G.user_input_buf;
1360 #endif /* INTERACTIVE */
1362 /* This is the magic location that prints prompts
1363 * and gets data back from the user */
1364 static int file_get(struct in_str *i)
1368 /* If there is data waiting, eat it up */
1369 if (i->p && *i->p) {
1370 #if ENABLE_HUSH_INTERACTIVE
1374 if (i->eof_flag && !*i->p)
1376 /* note: ch is never NUL */
1378 /* need to double check i->file because we might be doing something
1379 * more complicated by now, like sourcing or substituting. */
1380 #if ENABLE_HUSH_INTERACTIVE
1381 if (G_interactive_fd && i->promptme && i->file == stdin) {
1384 } while (!*i->p); /* need non-empty line */
1385 i->promptmode = 1; /* PS2 */
1390 do ch = fgetc(i->file); while (ch == '\0');
1392 debug_printf("file_get: got '%c' %d\n", ch, ch);
1393 #if ENABLE_HUSH_INTERACTIVE
1400 /* All callers guarantee this routine will never
1401 * be used right after a newline, so prompting is not needed.
1403 static int file_peek(struct in_str *i)
1406 if (i->p && *i->p) {
1407 if (i->eof_flag && !i->p[1])
1410 /* note: ch is never NUL */
1412 do ch = fgetc(i->file); while (ch == '\0');
1413 i->eof_flag = (ch == EOF);
1414 i->peek_buf[0] = ch;
1415 i->peek_buf[1] = '\0';
1417 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1421 static void setup_file_in_str(struct in_str *i, FILE *f)
1423 i->peek = file_peek;
1425 #if ENABLE_HUSH_INTERACTIVE
1427 i->promptmode = 0; /* PS1 */
1433 static void setup_string_in_str(struct in_str *i, const char *s)
1435 i->peek = static_peek;
1436 i->get = static_get;
1437 #if ENABLE_HUSH_INTERACTIVE
1439 i->promptmode = 0; /* PS1 */
1449 #define B_CHUNK (32 * sizeof(char*))
1451 static void o_reset_to_empty_unquoted(o_string *o)
1459 static void o_free(o_string *o)
1462 memset(o, 0, sizeof(*o));
1465 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1470 static void o_grow_by(o_string *o, int len)
1472 if (o->length + len > o->maxlen) {
1473 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1474 o->data = xrealloc(o->data, 1 + o->maxlen);
1478 static void o_addchr(o_string *o, int ch)
1480 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1482 o->data[o->length] = ch;
1484 o->data[o->length] = '\0';
1487 static void o_addblock(o_string *o, const char *str, int len)
1490 memcpy(&o->data[o->length], str, len);
1492 o->data[o->length] = '\0';
1496 static void o_addstr(o_string *o, const char *str)
1498 o_addblock(o, str, strlen(str));
1500 static void nommu_addchr(o_string *o, int ch)
1506 #define nommu_addchr(o, str) ((void)0)
1509 static void o_addstr_with_NUL(o_string *o, const char *str)
1511 o_addblock(o, str, strlen(str) + 1);
1514 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1519 && (*str != '*' && *str != '?' && *str != '[')
1527 /* My analysis of quoting semantics tells me that state information
1528 * is associated with a destination, not a source.
1530 static void o_addqchr(o_string *o, int ch)
1533 char *found = strchr("*?[\\", ch);
1538 o->data[o->length] = '\\';
1541 o->data[o->length] = ch;
1543 o->data[o->length] = '\0';
1546 static void o_addQchr(o_string *o, int ch)
1549 if (o->o_escape && strchr("*?[\\", ch)) {
1551 o->data[o->length] = '\\';
1555 o->data[o->length] = ch;
1557 o->data[o->length] = '\0';
1560 static void o_addQstr(o_string *o, const char *str, int len)
1563 o_addblock(o, str, len);
1569 int ordinary_cnt = strcspn(str, "*?[\\");
1570 if (ordinary_cnt > len) /* paranoia */
1572 o_addblock(o, str, ordinary_cnt);
1573 if (ordinary_cnt == len)
1575 str += ordinary_cnt;
1576 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1580 if (ch) { /* it is necessarily one of "*?[\\" */
1582 o->data[o->length] = '\\';
1586 o->data[o->length] = ch;
1588 o->data[o->length] = '\0';
1592 /* A special kind of o_string for $VAR and `cmd` expansion.
1593 * It contains char* list[] at the beginning, which is grown in 16 element
1594 * increments. Actual string data starts at the next multiple of 16 * (char*).
1595 * list[i] contains an INDEX (int!) into this string data.
1596 * It means that if list[] needs to grow, data needs to be moved higher up
1597 * but list[i]'s need not be modified.
1598 * NB: remembering how many list[i]'s you have there is crucial.
1599 * o_finalize_list() operation post-processes this structure - calculates
1600 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1602 #if DEBUG_EXPAND || DEBUG_GLOB
1603 static void debug_print_list(const char *prefix, o_string *o, int n)
1605 char **list = (char**)o->data;
1606 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1608 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1609 prefix, list, n, string_start, o->length, o->maxlen);
1611 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1612 o->data + (int)list[i] + string_start,
1613 o->data + (int)list[i] + string_start);
1617 const char *p = o->data + (int)list[n - 1] + string_start;
1618 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1622 #define debug_print_list(prefix, o, n) ((void)0)
1625 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1626 * in list[n] so that it points past last stored byte so far.
1627 * It returns n+1. */
1628 static int o_save_ptr_helper(o_string *o, int n)
1630 char **list = (char**)o->data;
1634 if (!o->has_empty_slot) {
1635 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1636 string_len = o->length - string_start;
1637 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1638 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1639 /* list[n] points to string_start, make space for 16 more pointers */
1640 o->maxlen += 0x10 * sizeof(list[0]);
1641 o->data = xrealloc(o->data, o->maxlen + 1);
1642 list = (char**)o->data;
1643 memmove(list + n + 0x10, list + n, string_len);
1644 o->length += 0x10 * sizeof(list[0]);
1646 debug_printf_list("list[%d]=%d string_start=%d\n",
1647 n, string_len, string_start);
1650 /* We have empty slot at list[n], reuse without growth */
1651 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1652 string_len = o->length - string_start;
1653 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1654 n, string_len, string_start);
1655 o->has_empty_slot = 0;
1657 list[n] = (char*)(ptrdiff_t)string_len;
1661 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1662 static int o_get_last_ptr(o_string *o, int n)
1664 char **list = (char**)o->data;
1665 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1667 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1670 /* o_glob performs globbing on last list[], saving each result
1671 * as a new list[]. */
1672 static int o_glob(o_string *o, int n)
1678 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1680 return o_save_ptr_helper(o, n);
1681 pattern = o->data + o_get_last_ptr(o, n);
1682 debug_printf_glob("glob pattern '%s'\n", pattern);
1683 if (!glob_needed(pattern)) {
1685 o->length = unbackslash(pattern) - o->data;
1686 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1687 return o_save_ptr_helper(o, n);
1690 memset(&globdata, 0, sizeof(globdata));
1691 gr = glob(pattern, 0, NULL, &globdata);
1692 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1693 if (gr == GLOB_NOSPACE)
1694 bb_error_msg_and_die("out of memory during glob");
1695 if (gr == GLOB_NOMATCH) {
1696 globfree(&globdata);
1699 if (gr != 0) { /* GLOB_ABORTED ? */
1700 //TODO: testcase for bad glob pattern behavior
1701 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1703 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1704 char **argv = globdata.gl_pathv;
1705 o->length = pattern - o->data; /* "forget" pattern */
1707 o_addstr_with_NUL(o, *argv);
1708 n = o_save_ptr_helper(o, n);
1714 globfree(&globdata);
1716 debug_print_list("o_glob returning", o, n);
1720 /* If o->o_glob == 1, glob the string so far remembered.
1721 * Otherwise, just finish current list[] and start new */
1722 static int o_save_ptr(o_string *o, int n)
1724 if (o->o_glob) { /* if globbing is requested */
1725 /* If o->has_empty_slot, list[n] was already globbed
1726 * (if it was requested back then when it was filled)
1727 * so don't do that again! */
1728 if (!o->has_empty_slot)
1729 return o_glob(o, n); /* o_save_ptr_helper is inside */
1731 return o_save_ptr_helper(o, n);
1734 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1735 static char **o_finalize_list(o_string *o, int n)
1740 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1742 debug_print_list("finalized", o, n);
1743 debug_printf_expand("finalized n:%d\n", n);
1744 list = (char**)o->data;
1745 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1749 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1755 /* Expansion can recurse */
1756 #if ENABLE_HUSH_TICK
1757 static int process_command_subs(o_string *dest, const char *s);
1759 static char *expand_string_to_string(const char *str);
1761 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1762 parse_stream_dquoted(dest, input, dquote_end)
1764 static int parse_stream_dquoted(o_string *as_string,
1766 struct in_str *input,
1769 /* expand_strvec_to_strvec() takes a list of strings, expands
1770 * all variable references within and returns a pointer to
1771 * a list of expanded strings, possibly with larger number
1772 * of strings. (Think VAR="a b"; echo $VAR).
1773 * This new list is allocated as a single malloc block.
1774 * NULL-terminated list of char* pointers is at the beginning of it,
1775 * followed by strings themself.
1776 * Caller can deallocate entire list by single free(list). */
1778 /* Store given string, finalizing the word and starting new one whenever
1779 * we encounter IFS char(s). This is used for expanding variable values.
1780 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1781 static int expand_on_ifs(o_string *output, int n, const char *str)
1784 int word_len = strcspn(str, G.ifs);
1786 if (output->o_escape || !output->o_glob)
1787 o_addQstr(output, str, word_len);
1788 else /* protect backslashes against globbing up :) */
1789 o_addblock_duplicate_backslash(output, str, word_len);
1792 if (!*str) /* EOL - do not finalize word */
1794 o_addchr(output, '\0');
1795 debug_print_list("expand_on_ifs", output, n);
1796 n = o_save_ptr(output, n);
1797 str += strspn(str, G.ifs); /* skip ifs chars */
1799 debug_print_list("expand_on_ifs[1]", output, n);
1803 /* Helper to expand $((...)) and heredoc body. These act as if
1804 * they are in double quotes, with the exception that they are not :).
1805 * Just the rules are similar: "expand only $var and `cmd`"
1807 * Returns malloced string.
1808 * As an optimization, we return NULL if expansion is not needed.
1810 static char *expand_pseudo_dquoted(const char *str)
1813 struct in_str input;
1814 o_string dest = NULL_O_STRING;
1816 if (strchr(str, '$') == NULL
1817 #if ENABLE_HUSH_TICK
1818 && strchr(str, '`') == NULL
1824 /* We need to expand. Example:
1825 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1827 setup_string_in_str(&input, str);
1828 parse_stream_dquoted(NULL, &dest, &input, EOF);
1829 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1830 exp_str = expand_string_to_string(dest.data);
1831 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1832 o_free_unsafe(&dest);
1836 /* Expand all variable references in given string, adding words to list[]
1837 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1838 * to be filled). This routine is extremely tricky: has to deal with
1839 * variables/parameters with whitespace, $* and $@, and constructs like
1840 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1841 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1843 /* or_mask is either 0 (normal case) or 0x80
1844 * (expansion of right-hand side of assignment == 1-element expand.
1845 * It will also do no globbing, and thus we must not backslash-quote!) */
1847 char first_ch, ored_ch;
1855 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1856 debug_print_list("expand_vars_to_list", output, n);
1857 n = o_save_ptr(output, n);
1858 debug_print_list("expand_vars_to_list[0]", output, n);
1860 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1861 #if ENABLE_HUSH_TICK
1862 o_string subst_result = NULL_O_STRING;
1864 #if ENABLE_SH_MATH_SUPPORT
1865 char arith_buf[sizeof(arith_t)*3 + 2];
1867 o_addblock(output, arg, p - arg);
1868 debug_print_list("expand_vars_to_list[1]", output, n);
1870 p = strchr(p, SPECIAL_VAR_SYMBOL);
1872 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1873 /* "$@" is special. Even if quoted, it can still
1874 * expand to nothing (not even an empty string) */
1875 if ((first_ch & 0x7f) != '@')
1876 ored_ch |= first_ch;
1879 switch (first_ch & 0x7f) {
1880 /* Highest bit in first_ch indicates that var is double-quoted */
1882 val = utoa(G.root_pid);
1884 case '!': /* bg pid */
1885 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1887 case '?': /* exitcode */
1888 val = utoa(G.last_exitcode);
1890 case '#': /* argc */
1891 if (arg[1] != SPECIAL_VAR_SYMBOL)
1892 /* actually, it's a ${#var} */
1894 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1899 if (!G.global_argv[i])
1901 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1902 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1903 smallint sv = output->o_escape;
1904 /* unquoted var's contents should be globbed, so don't escape */
1905 output->o_escape = 0;
1906 while (G.global_argv[i]) {
1907 n = expand_on_ifs(output, n, G.global_argv[i]);
1908 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1909 if (G.global_argv[i++][0] && G.global_argv[i]) {
1910 /* this argv[] is not empty and not last:
1911 * put terminating NUL, start new word */
1912 o_addchr(output, '\0');
1913 debug_print_list("expand_vars_to_list[2]", output, n);
1914 n = o_save_ptr(output, n);
1915 debug_print_list("expand_vars_to_list[3]", output, n);
1918 output->o_escape = sv;
1920 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1921 * and in this case should treat it like '$*' - see 'else...' below */
1922 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1924 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1925 if (++i >= G.global_argc)
1927 o_addchr(output, '\0');
1928 debug_print_list("expand_vars_to_list[4]", output, n);
1929 n = o_save_ptr(output, n);
1931 } else { /* quoted $*: add as one word */
1933 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1934 if (!G.global_argv[++i])
1937 o_addchr(output, G.ifs[0]);
1941 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1942 /* "Empty variable", used to make "" etc to not disappear */
1946 #if ENABLE_HUSH_TICK
1947 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1950 //TODO: can we just stuff it into "output" directly?
1951 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1952 process_command_subs(&subst_result, arg);
1953 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1954 val = subst_result.data;
1957 #if ENABLE_SH_MATH_SUPPORT
1958 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1959 arith_eval_hooks_t hooks;
1964 arg++; /* skip '+' */
1965 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1966 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1968 exp_str = expand_pseudo_dquoted(arg);
1969 hooks.lookupvar = get_local_var_value;
1970 hooks.setvar = arith_set_local_var;
1971 hooks.endofname = endofname;
1972 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1976 const char *msg = "error in arithmetic";
1979 msg = "exponent less than 0";
1982 msg = "divide by 0";
1985 msg = "expression recursion loop detected";
1990 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1991 sprintf(arith_buf, arith_t_fmt, res);
1996 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1998 bool exp_len = false;
1999 bool exp_null = false;
2001 char exp_save = exp_save; /* for compiler */
2002 char exp_op = exp_op; /* for compiler */
2003 char *exp_word = exp_word; /* for compiler */
2007 arg[0] = first_ch & 0x7f;
2009 /* prepare for expansions */
2010 if (var[0] == '#') {
2011 /* handle length expansion ${#var} */
2015 /* maybe handle parameter expansion */
2016 exp_off = strcspn(var, ":-=+?%#");
2020 exp_save = var[exp_off];
2021 exp_null = exp_save == ':';
2022 exp_word = var + exp_off;
2025 exp_op = *exp_word++;
2026 var[exp_off] = '\0';
2030 /* lookup the variable in question */
2031 if (isdigit(var[0])) {
2032 /* handle_dollar() should have vetted var for us */
2034 if (i < G.global_argc)
2035 val = G.global_argv[i];
2036 /* else val remains NULL: $N with too big N */
2038 val = get_local_var_value(var);
2040 /* handle any expansions */
2042 debug_printf_expand("expand: length of '%s' = ", val);
2043 val = utoa(val ? strlen(val) : 0);
2044 debug_printf_expand("%s\n", val);
2045 } else if (exp_off) {
2046 if (exp_op == '%' || exp_op == '#') {
2048 /* we need to do a pattern match */
2051 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2052 if (exp_op == *exp_word) /* ## or %% */
2054 val = dyn_val = xstrdup(val);
2055 loc = scan(dyn_val, exp_word, zero);
2062 /* we need to do an expansion */
2063 int exp_test = (!val || (exp_null && !val[0]));
2065 exp_test = !exp_test;
2066 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2067 exp_null ? "true" : "false", exp_test);
2069 if (exp_op == '?') {
2070 //TODO: how interactive bash aborts expansion mid-command?
2071 /* ${var?[error_msg_if_unset]} */
2072 /* ${var:?[error_msg_if_unset_or_null]} */
2073 /* mimic bash message */
2074 die_if_script("%s: %s",
2076 exp_word[0] ? exp_word : "parameter null or not set"
2082 if (exp_op == '=') {
2083 /* ${var=[word]} or ${var:=[word]} */
2084 if (isdigit(var[0]) || var[0] == '#') {
2085 /* mimic bash message */
2086 die_if_script("$%s: cannot assign in this way", var);
2089 char *new_var = xasprintf("%s=%s", var, val);
2090 set_local_var(new_var, -1, 0);
2096 var[exp_off] = exp_save;
2100 #if ENABLE_HUSH_TICK
2103 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2104 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2106 /* unquoted var's contents should be globbed, so don't escape */
2107 smallint sv = output->o_escape;
2108 output->o_escape = 0;
2109 n = expand_on_ifs(output, n, val);
2111 output->o_escape = sv;
2113 } else { /* quoted $VAR, val will be appended below */
2114 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2117 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2119 o_addQstr(output, val, strlen(val));
2123 /* Do the check to avoid writing to a const string */
2124 if (*p != SPECIAL_VAR_SYMBOL)
2125 *p = SPECIAL_VAR_SYMBOL;
2127 #if ENABLE_HUSH_TICK
2128 o_free(&subst_result);
2131 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2134 debug_print_list("expand_vars_to_list[a]", output, n);
2135 /* this part is literal, and it was already pre-quoted
2136 * if needed (much earlier), do not use o_addQstr here! */
2137 o_addstr_with_NUL(output, arg);
2138 debug_print_list("expand_vars_to_list[b]", output, n);
2139 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2140 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2143 /* allow to reuse list[n] later without re-growth */
2144 output->has_empty_slot = 1;
2146 o_addchr(output, '\0');
2151 static char **expand_variables(char **argv, int or_mask)
2156 o_string output = NULL_O_STRING;
2158 if (or_mask & 0x100) {
2159 output.o_escape = 1; /* protect against globbing for "$var" */
2160 /* (unquoted $var will temporarily switch it off) */
2167 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2170 debug_print_list("expand_variables", &output, n);
2172 /* output.data (malloced in one block) gets returned in "list" */
2173 list = o_finalize_list(&output, n);
2174 debug_print_strings("expand_variables[1]", list);
2178 static char **expand_strvec_to_strvec(char **argv)
2180 return expand_variables(argv, 0x100);
2183 /* Used for expansion of right hand of assignments */
2184 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2186 static char *expand_string_to_string(const char *str)
2188 char *argv[2], **list;
2190 argv[0] = (char*)str;
2192 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2194 if (!list[0] || list[1])
2195 bb_error_msg_and_die("BUG in varexp2");
2196 /* actually, just move string 2*sizeof(char*) bytes back */
2197 overlapping_strcpy((char*)list, list[0]);
2198 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2202 /* Used for "eval" builtin */
2203 static char* expand_strvec_to_string(char **argv)
2207 list = expand_variables(argv, 0x80);
2208 /* Convert all NULs to spaces */
2213 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2214 bb_error_msg_and_die("BUG in varexp3");
2215 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2219 overlapping_strcpy((char*)list, list[0]);
2220 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2224 static char **expand_assignments(char **argv, int count)
2228 /* Expand assignments into one string each */
2229 for (i = 0; i < count; i++) {
2230 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2237 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2238 #define clean_up_after_re_execute() ((void)0)
2239 static void reset_traps_to_defaults(void)
2247 for (sig = 0; sig < NSIG; sig++) {
2251 G.traps[sig] = NULL;
2252 /* There is no signal for 0 (EXIT) */
2255 /* there was a trap handler, we are removing it
2256 * (if sig has non-DFL handling,
2257 * we don't need to do anything) */
2258 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2260 sigdelset(&G.blocked_set, sig);
2264 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2269 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2270 static void re_execute_shell(const char *s, int is_heredoc)
2272 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2273 char *heredoc_argv[4];
2274 struct variable *cur;
2275 char **argv, **pp, **pp2;
2279 argv = heredoc_argv;
2280 argv[0] = (char *) G.argv0_for_re_execing;
2281 argv[1] = (char *) "-<";
2282 argv[2] = (char *) s;
2284 pp = &argv[3]; /* used as pointer to empty environment */
2288 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2289 , (unsigned) G.root_pid
2290 , (unsigned) G.last_bg_pid
2291 , (unsigned) G.last_exitcode
2292 USE_HUSH_LOOPS(, G.depth_of_loop)
2294 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2295 * 3:-c 4:<cmd> <argN...> 5:NULL
2297 cnt = 5 + G.global_argc;
2298 for (cur = G.top_var; cur; cur = cur->next) {
2299 if (!cur->flg_export || cur->flg_read_only)
2302 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2303 *pp++ = (char *) G.argv0_for_re_execing;
2305 for (cur = G.top_var; cur; cur = cur->next) {
2306 if (cur->varstr == hush_version_str)
2308 if (cur->flg_read_only) {
2309 *pp++ = (char *) "-R";
2310 *pp++ = cur->varstr;
2311 } else if (!cur->flg_export) {
2312 *pp++ = (char *) "-V";
2313 *pp++ = cur->varstr;
2316 //TODO: pass functions
2317 /* We can pass activated traps here. Say, -Tnn:trap_string
2319 * However, POSIX says that subshells reset signals with traps
2321 * I tested bash-3.2 and it not only does that with true subshells
2322 * of the form ( list ), but with any forked children shells.
2323 * I set trap "echo W" WINCH; and then tried:
2325 * { echo 1; sleep 20; echo 2; } &
2326 * while true; do echo 1; sleep 20; echo 2; break; done &
2327 * true | { echo 1; sleep 20; echo 2; } | cat
2329 * In all these cases sending SIGWINCH to the child shell
2330 * did not run the trap. If I add trap "echo V" WINCH;
2331 * _inside_ group (just before echo 1), it works.
2333 * I conclude it means we don't need to pass active traps here.
2334 * exec syscall below resets them to SIG_DFL for us.
2336 *pp++ = (char *) "-c";
2338 pp2 = G.global_argv;
2341 /* *pp = NULL; - is already there */
2345 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2346 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2347 execve(bb_busybox_exec_path, argv, pp);
2348 /* Fallback. Useful for init=/bin/hush usage etc */
2349 if (argv[0][0] == '/')
2350 execve(argv[0], argv, pp);
2351 xfunc_error_retval = 127;
2352 bb_error_msg_and_die("can't re-execute the shell");
2355 static void clean_up_after_re_execute(void)
2357 char **pp = G.argv_from_re_execing;
2359 /* Must match re_execute_shell's allocations (if any) */
2361 G.argv_from_re_execing = NULL;
2364 #endif /* !BB_MMU */
2367 static void setup_heredoc(struct redir_struct *redir)
2369 struct fd_pair pair;
2372 /* the _body_ of heredoc (misleading field name) */
2373 const char *heredoc = redir->rd_filename;
2377 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2378 expanded = expand_pseudo_dquoted(heredoc);
2382 len = strlen(heredoc);
2384 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2386 xmove_fd(pair.rd, redir->rd_fd);
2388 /* Try writing without forking. Newer kernels have
2389 * dynamically growing pipes. Must use non-blocking write! */
2392 written = write(pair.wr, heredoc, len);
2403 ndelay_off(pair.wr);
2405 /* Okay, pipe buffer was not big enough */
2406 /* Note: we must not create a stray child (bastard? :)
2407 * for the unsuspecting parent process. Child creates a grandchild
2408 * and exits before parent execs the process which consumes heredoc
2409 * (that exec happens after we return from this function) */
2412 bb_perror_msg_and_die("vfork");
2415 pid = BB_MMU ? fork() : vfork();
2417 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2421 close(redir->rd_fd); /* read side of the pipe */
2423 full_write(pair.wr, heredoc, len); /* may loop or block */
2426 /* Delegate blocking writes to another process */
2427 disable_restore_tty_pgrp_on_exit();
2428 xmove_fd(pair.wr, STDOUT_FILENO);
2429 re_execute_shell(heredoc, 1);
2433 enable_restore_tty_pgrp_on_exit();
2434 clean_up_after_re_execute();
2437 wait(NULL); /* wait till child has died */
2440 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2441 * and stderr if they are redirected. */
2442 static int setup_redirects(struct command *prog, int squirrel[])
2445 struct redir_struct *redir;
2447 for (redir = prog->redirects; redir; redir = redir->next) {
2448 if (redir->rd_type == REDIRECT_HEREDOC2) {
2449 /* rd_fd<<HERE case */
2450 if (squirrel && redir->rd_fd < 3) {
2451 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2453 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2455 debug_printf_parse("set heredoc '%s'\n",
2456 redir->rd_filename);
2457 setup_heredoc(redir);
2461 if (redir->rd_dup == REDIRFD_TO_FILE) {
2462 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2464 if (redir->rd_filename == NULL) {
2465 /* Something went wrong in the parse.
2466 * Pretend it didn't happen */
2467 bb_error_msg("bug in redirect parse");
2470 mode = redir_table[redir->rd_type].mode;
2471 p = expand_string_to_string(redir->rd_filename);
2472 openfd = open_or_warn(p, mode);
2475 /* this could get lost if stderr has been redirected, but
2476 * bash and ash both lose it as well (though zsh doesn't!) */
2477 //what the above comment tries to say?
2481 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2482 openfd = redir->rd_dup;
2485 if (openfd != redir->rd_fd) {
2486 if (squirrel && redir->rd_fd < 3) {
2487 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2489 if (openfd == REDIRFD_CLOSE) {
2490 /* "n>-" means "close me" */
2491 close(redir->rd_fd);
2493 xdup2(openfd, redir->rd_fd);
2494 if (redir->rd_dup == REDIRFD_TO_FILE)
2502 static void restore_redirects(int squirrel[])
2505 for (i = 0; i < 3; i++) {
2508 /* We simply die on error */
2516 #define free_pipe_list(head, indent) free_pipe_list(head)
2517 #define free_pipe(pi, indent) free_pipe(pi)
2519 static void free_pipe_list(struct pipe *head, int indent);
2521 /* Return code is the exit status of the pipe */
2522 static void free_pipe(struct pipe *pi, int indent)
2525 struct command *command;
2526 struct redir_struct *r, *rnext;
2529 if (pi->stopped_cmds > 0) /* why? */
2531 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2532 for (i = 0; i < pi->num_cmds; i++) {
2533 command = &pi->cmds[i];
2534 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2535 if (command->argv) {
2536 for (a = 0, p = command->argv; *p; a++, p++) {
2537 debug_printf_clean("%s argv[%d] = %s\n",
2538 indenter(indent), a, *p);
2540 free_strings(command->argv);
2541 command->argv = NULL;
2543 /* not "else if": on syntax error, we may have both! */
2544 if (command->group) {
2545 debug_printf_clean("%s begin group (grp_type:%d)\n",
2546 indenter(indent), command->grp_type);
2547 free_pipe_list(command->group, indent+3);
2548 debug_printf_clean("%s end group\n", indenter(indent));
2549 command->group = NULL;
2552 free(command->group_as_string);
2553 command->group_as_string = NULL;
2555 for (r = command->redirects; r; r = rnext) {
2556 debug_printf_clean("%s redirect %d%s", indenter(indent),
2557 r->fd, redir_table[r->rd_type].descrip);
2558 /* guard against the case >$FOO, where foo is unset or blank */
2559 if (r->rd_filename) {
2560 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2561 free(r->rd_filename);
2562 r->rd_filename = NULL;
2564 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2568 command->redirects = NULL;
2570 free(pi->cmds); /* children are an array, they get freed all at once */
2578 static void free_pipe_list(struct pipe *head, int indent)
2580 struct pipe *pi, *next;
2582 for (pi = head; pi; pi = next) {
2584 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2586 free_pipe(pi, indent);
2587 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2589 /*pi->next = NULL;*/
2595 static const struct built_in_command* find_builtin(const char *name)
2597 const struct built_in_command *x;
2598 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2599 if (strcmp(name, x->cmd) != 0)
2601 debug_printf_exec("found builtin '%s'\n", name);
2607 # if ENABLE_HUSH_FUNCTIONS
2608 static const struct function *find_function(const char *name)
2610 const struct function *funcp = G.top_func;
2612 if (strcmp(name, funcp->name) != 0)
2615 debug_printf_exec("found function '%s'\n", name);
2622 static int run_list(struct pipe *pi);
2625 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2626 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2627 #define pseudo_exec(nommu_save, command, argv_expanded) \
2628 pseudo_exec(command, argv_expanded)
2631 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2633 * XXX no exit() here. If you don't exec, use _exit instead.
2634 * The at_exit handlers apparently confuse the calling process,
2635 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2636 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2637 char **argv, int assignment_cnt,
2638 char **argv_expanded) NORETURN;
2639 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2640 char **argv, int assignment_cnt,
2641 char **argv_expanded)
2645 /* Case when we are here: ... | var=val | ... */
2646 if (!argv[assignment_cnt])
2647 _exit(EXIT_SUCCESS);
2649 new_env = expand_assignments(argv, assignment_cnt);
2651 putenv_all(new_env);
2652 free(new_env); /* optional */
2654 nommu_save->new_env = new_env;
2655 nommu_save->old_env = putenv_all_and_save_old(new_env);
2657 if (argv_expanded) {
2658 argv = argv_expanded;
2660 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2662 nommu_save->argv = argv;
2666 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2667 if (strchr(argv[0], '/') != NULL)
2671 /* On NOMMU, we must never block!
2672 * Example: { sleep 99999 | read line } & echo Ok
2673 * read builtin will block on read syscall, leaving parent blocked
2674 * in vfork. Therefore we can't do this:
2677 /* Check if the command matches any of the builtins.
2678 * Depending on context, this might be redundant. But it's
2679 * easier to waste a few CPU cycles than it is to figure out
2680 * if this is one of those cases.
2684 const struct built_in_command *x = find_builtin(argv[0]);
2686 rcode = x->function(argv);
2691 # if ENABLE_HUSH_FUNCTIONS
2692 /* Check if the command matches any functions */
2695 const struct function *funcp = find_function(argv[0]);
2697 rcode = run_list(funcp->body);
2705 #if ENABLE_FEATURE_SH_STANDALONE
2706 /* Check if the command matches any busybox applets */
2708 int a = find_applet_by_name(argv[0]);
2710 # if BB_MMU /* see above why on NOMMU it is not allowed */
2711 if (APPLET_IS_NOEXEC(a)) {
2712 debug_printf_exec("running applet '%s'\n", argv[0]);
2713 run_applet_no_and_exit(a, argv);
2716 /* Re-exec ourselves */
2717 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2718 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2719 execv(bb_busybox_exec_path, argv);
2720 /* If they called chroot or otherwise made the binary no longer
2721 * executable, fall through */
2727 debug_printf_exec("execing '%s'\n", argv[0]);
2728 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2729 execvp(argv[0], argv);
2730 bb_perror_msg("can't exec '%s'", argv[0]);
2731 _exit(EXIT_FAILURE);
2734 /* Called after [v]fork() in run_pipe
2736 static void pseudo_exec(nommu_save_t *nommu_save,
2737 struct command *command,
2738 char **argv_expanded) NORETURN;
2739 static void pseudo_exec(nommu_save_t *nommu_save,
2740 struct command *command,
2741 char **argv_expanded)
2743 if (command->argv) {
2744 pseudo_exec_argv(nommu_save, command->argv,
2745 command->assignment_cnt, argv_expanded);
2748 if (command->group) {
2749 /* Cases when we are here:
2752 * ... | ( list ) | ...
2753 * ... | { list } | ...
2757 debug_printf_exec("pseudo_exec: run_list\n");
2758 reset_traps_to_defaults();
2759 rcode = run_list(command->group);
2760 /* OK to leak memory by not calling free_pipe_list,
2761 * since this process is about to exit */
2764 re_execute_shell(command->group_as_string, 0);
2768 /* Case when we are here: ... | >file */
2769 debug_printf_exec("pseudo_exec'ed null command\n");
2770 _exit(EXIT_SUCCESS);
2774 static const char *get_cmdtext(struct pipe *pi)
2780 /* This is subtle. ->cmdtext is created only on first backgrounding.
2781 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2782 * On subsequent bg argv is trashed, but we won't use it */
2785 argv = pi->cmds[0].argv;
2786 if (!argv || !argv[0]) {
2787 pi->cmdtext = xzalloc(1);
2792 do len += strlen(*argv) + 1; while (*++argv);
2793 pi->cmdtext = p = xmalloc(len);
2794 argv = pi->cmds[0].argv;
2796 len = strlen(*argv);
2797 memcpy(p, *argv, len);
2805 static void insert_bg_job(struct pipe *pi)
2807 struct pipe *thejob;
2810 /* Linear search for the ID of the job to use */
2812 for (thejob = G.job_list; thejob; thejob = thejob->next)
2813 if (thejob->jobid >= pi->jobid)
2814 pi->jobid = thejob->jobid + 1;
2816 /* Add thejob to the list of running jobs */
2818 thejob = G.job_list = xmalloc(sizeof(*thejob));
2820 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2822 thejob->next = xmalloc(sizeof(*thejob));
2823 thejob = thejob->next;
2826 /* Physically copy the struct job */
2827 memcpy(thejob, pi, sizeof(struct pipe));
2828 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2829 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2830 for (i = 0; i < pi->num_cmds; i++) {
2831 // TODO: do we really need to have so many fields which are just dead weight
2832 // at execution stage?
2833 thejob->cmds[i].pid = pi->cmds[i].pid;
2834 /* all other fields are not used and stay zero */
2836 thejob->next = NULL;
2837 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2839 /* We don't wait for background thejobs to return -- append it
2840 to the list of backgrounded thejobs and leave it alone */
2841 if (G_interactive_fd)
2842 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2843 G.last_bg_pid = thejob->cmds[0].pid;
2844 G.last_jobid = thejob->jobid;
2847 static void remove_bg_job(struct pipe *pi)
2849 struct pipe *prev_pipe;
2851 if (pi == G.job_list) {
2852 G.job_list = pi->next;
2854 prev_pipe = G.job_list;
2855 while (prev_pipe->next != pi)
2856 prev_pipe = prev_pipe->next;
2857 prev_pipe->next = pi->next;
2860 G.last_jobid = G.job_list->jobid;
2865 /* Remove a backgrounded job */
2866 static void delete_finished_bg_job(struct pipe *pi)
2869 pi->stopped_cmds = 0;
2875 /* Check to see if any processes have exited -- if they
2876 * have, figure out why and see if a job has completed */
2877 static int checkjobs(struct pipe* fg_pipe)
2887 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2890 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2891 // /* avoid doing syscall, nothing there anyway */
2894 attributes = WUNTRACED;
2895 if (fg_pipe == NULL)
2896 attributes |= WNOHANG;
2898 /* Do we do this right?
2899 * bash-3.00# sleep 20 | false
2901 * [3]+ Stopped sleep 20 | false
2902 * bash-3.00# echo $?
2903 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2906 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2907 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2908 // + killall -STOP cat
2915 // i = G.count_SIGCHLD;
2916 childpid = waitpid(-1, &status, attributes);
2917 if (childpid <= 0) {
2918 if (childpid && errno != ECHILD)
2919 bb_perror_msg("waitpid");
2920 // else /* Until next SIGCHLD, waitpid's are useless */
2921 // G.handled_SIGCHLD = i;
2924 dead = WIFEXITED(status) || WIFSIGNALED(status);
2927 if (WIFSTOPPED(status))
2928 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2929 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2930 if (WIFSIGNALED(status))
2931 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2932 childpid, WTERMSIG(status), WEXITSTATUS(status));
2933 if (WIFEXITED(status))
2934 debug_printf_jobs("pid %d exited, exitcode %d\n",
2935 childpid, WEXITSTATUS(status));
2937 /* Were we asked to wait for fg pipe? */
2939 for (i = 0; i < fg_pipe->num_cmds; i++) {
2940 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2941 if (fg_pipe->cmds[i].pid != childpid)
2943 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2945 fg_pipe->cmds[i].pid = 0;
2946 fg_pipe->alive_cmds--;
2947 if (i == fg_pipe->num_cmds - 1) {
2948 /* last process gives overall exitstatus */
2949 rcode = WEXITSTATUS(status);
2950 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2953 fg_pipe->cmds[i].is_stopped = 1;
2954 fg_pipe->stopped_cmds++;
2956 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2957 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2958 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2959 /* All processes in fg pipe have exited/stopped */
2961 if (fg_pipe->alive_cmds)
2962 insert_bg_job(fg_pipe);
2966 /* There are still running processes in the fg pipe */
2967 goto wait_more; /* do waitpid again */
2969 /* it wasnt fg_pipe, look for process in bg pipes */
2973 /* We asked to wait for bg or orphaned children */
2974 /* No need to remember exitcode in this case */
2975 for (pi = G.job_list; pi; pi = pi->next) {
2976 for (i = 0; i < pi->num_cmds; i++) {
2977 if (pi->cmds[i].pid == childpid)
2978 goto found_pi_and_prognum;
2981 /* Happens when shell is used as init process (init=/bin/sh) */
2982 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2983 continue; /* do waitpid again */
2985 found_pi_and_prognum:
2988 pi->cmds[i].pid = 0;
2990 if (!pi->alive_cmds) {
2991 if (G_interactive_fd)
2992 printf(JOB_STATUS_FORMAT, pi->jobid,
2993 "Done", pi->cmdtext);
2994 delete_finished_bg_job(pi);
2998 pi->cmds[i].is_stopped = 1;
3002 } /* while (waitpid succeeds)... */
3008 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3011 int rcode = checkjobs(fg_pipe);
3012 /* Job finished, move the shell to the foreground */
3013 p = getpgid(0); /* pgid of our process */
3014 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3015 tcsetpgrp(G_interactive_fd, p);
3020 /* Start all the jobs, but don't wait for anything to finish.
3023 * Return code is normally -1, when the caller has to wait for children
3024 * to finish to determine the exit status of the pipe. If the pipe
3025 * is a simple builtin command, however, the action is done by the
3026 * time run_pipe returns, and the exit code is provided as the
3029 * Returns -1 only if started some children. IOW: we have to
3030 * mask out retvals of builtins etc with 0xff!
3032 * The only case when we do not need to [v]fork is when the pipe
3033 * is single, non-backgrounded, non-subshell command. Examples:
3034 * cmd ; ... { list } ; ...
3035 * cmd && ... { list } && ...
3036 * cmd || ... { list } || ...
3037 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3038 * or (if SH_STANDALONE) an applet, and we can run the { list }
3039 * with run_list(). If it isn't one of these, we fork and exec cmd.
3041 * Cases when we must fork:
3042 * non-single: cmd | cmd
3043 * backgrounded: cmd & { list } &
3044 * subshell: ( list ) [&]
3046 static int run_pipe(struct pipe *pi)
3048 static const char *const null_ptr = NULL;
3051 int pipefds[2]; /* pipefds[0] is for reading */
3052 struct command *command;
3053 char **argv_expanded;
3056 /* it is not always needed, but we aim to smaller code */
3057 int squirrel[] = { -1, -1, -1 };
3060 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3062 USE_HUSH_JOB(pi->pgrp = -1;)
3063 pi->stopped_cmds = 0;
3064 command = &(pi->cmds[0]);
3065 argv_expanded = NULL;
3067 if (pi->num_cmds != 1
3068 || pi->followup == PIPE_BG
3069 || command->grp_type == GRP_SUBSHELL
3076 debug_printf_exec(": group:%p argv:'%s'\n",
3077 command->group, command->argv ? command->argv[0] : "NONE");
3079 if (command->group) {
3080 #if ENABLE_HUSH_FUNCTIONS
3081 if (command->grp_type == GRP_FUNCTION) {
3082 /* "executing" func () { list } */
3083 struct function *funcp;
3084 struct function **funcpp = &G.top_func;
3086 while ((funcp = *funcpp) != NULL) {
3087 if (strcmp(funcp->name, command->argv[0]) == 0) {
3088 debug_printf_exec("replacing function '%s'", funcp->name);
3090 free_pipe_list(funcp->body, /* indent: */ 0);
3093 funcpp = &funcp->next;
3095 debug_printf_exec("remembering new function '%s'", funcp->name);
3096 funcp = *funcpp = xzalloc(sizeof(*funcp));
3097 /*funcp->next = NULL;*/
3099 funcp->name = command->argv[0];
3100 funcp->body = command->group;
3101 command->group = NULL;
3102 command->argv[0] = NULL;
3103 free_strings(command->argv);
3104 command->argv = NULL;
3105 /* note: if we are in a loop, future "executions"
3106 * of func def will see it as null command since
3107 * command->group == NULL and command->argv == NULL */
3108 //this isn't exactly right: while...do f1() {a;}; f1; f1 {b;}; done
3109 //second loop will execute b!
3111 return EXIT_SUCCESS;
3115 debug_printf("non-subshell group\n");
3116 rcode = 1; /* exitcode if redir failed */
3117 if (setup_redirects(command, squirrel) == 0) {
3118 debug_printf_exec(": run_list\n");
3119 rcode = run_list(command->group) & 0xff;
3120 debug_printf_exec("run_pipe return %d\n", rcode);
3122 restore_redirects(squirrel);
3123 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3127 argv = command->argv ? command->argv : (char **) &null_ptr;
3129 const struct built_in_command *x;
3130 #if ENABLE_HUSH_FUNCTIONS
3131 const struct function *funcp;
3135 char **new_env = NULL;
3136 char **old_env = NULL;
3138 if (argv[command->assignment_cnt] == NULL) {
3139 /* Assignments, but no command */
3140 /* Ensure redirects take effect. Try "a=t >file" */
3141 rcode = setup_redirects(command, squirrel);
3142 restore_redirects(squirrel);
3143 /* Set shell variables */
3145 p = expand_string_to_string(*argv);
3146 debug_printf_exec("set shell var:'%s'->'%s'\n",
3148 set_local_var(p, 0, 0);
3151 /* Do we need to flag set_local_var() errors?
3152 * "assignment to readonly var" and "putenv error"
3154 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3158 /* Expand the rest into (possibly) many strings each */
3159 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3161 x = find_builtin(argv_expanded[0]);
3162 #if ENABLE_HUSH_FUNCTIONS
3164 funcp = find_function(argv_expanded[0]);
3168 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3169 debug_printf("exec with redirects only\n");
3170 rcode = setup_redirects(command, NULL);
3171 goto clean_up_and_ret1;
3174 debug_printf("builtin inline %s\n", argv_expanded[0]);
3175 /* XXX setup_redirects acts on file descriptors, not FILEs.
3176 * This is perfect for work that comes after exec().
3177 * Is it really safe for inline use? Experimentally,
3178 * things seem to work with glibc. */
3179 rcode = setup_redirects(command, squirrel);
3181 new_env = expand_assignments(argv, command->assignment_cnt);
3182 old_env = putenv_all_and_save_old(new_env);
3184 debug_printf_exec(": builtin '%s' '%s'...\n",
3185 x->cmd, argv_expanded[1]);
3186 rcode = x->function(argv_expanded) & 0xff;
3188 #if ENABLE_HUSH_FUNCTIONS
3190 debug_printf_exec(": function '%s' '%s'...\n",
3191 funcp->name, argv_expanded[1]);
3192 rcode = run_list(funcp->body) & 0xff;
3196 #if ENABLE_FEATURE_SH_STANDALONE
3199 restore_redirects(squirrel);
3200 free_strings_and_unsetenv(new_env, 1);
3201 putenv_all(old_env);
3202 /* Free the pointers, but the strings themselves
3203 * are in environ now, don't use free_strings! */
3206 free(argv_expanded);
3207 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3208 debug_printf_exec("run_pipe return %d\n", rcode);
3212 #if ENABLE_FEATURE_SH_STANDALONE
3213 i = find_applet_by_name(argv_expanded[0]);
3214 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3215 rcode = setup_redirects(command, squirrel);
3217 save_nofork_data(&G.nofork_save);
3218 new_env = expand_assignments(argv, command->assignment_cnt);
3219 old_env = putenv_all_and_save_old(new_env);
3220 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3221 argv_expanded[0], argv_expanded[1]);
3222 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3224 goto clean_up_and_ret;
3227 /* It is neither builtin nor applet. We must fork. */
3231 /* NB: argv_expanded may already be created, and that
3232 * might include `cmd` runs! Do not rerun it! We *must*
3233 * use argv_expanded if it's non-NULL */
3235 /* Going to fork a child per each pipe member */
3239 for (i = 0; i < pi->num_cmds; i++) {
3241 volatile nommu_save_t nommu_save;
3242 nommu_save.new_env = NULL;
3243 nommu_save.old_env = NULL;
3244 nommu_save.argv = NULL;
3246 command = &(pi->cmds[i]);
3247 if (command->argv) {
3248 debug_printf_exec(": pipe member '%s' '%s'...\n",
3249 command->argv[0], command->argv[1]);
3251 debug_printf_exec(": pipe member with no argv\n");
3254 /* pipes are inserted between pairs of commands */
3257 if ((i + 1) < pi->num_cmds)
3260 command->pid = BB_MMU ? fork() : vfork();
3261 if (!command->pid) { /* child */
3263 disable_restore_tty_pgrp_on_exit();
3265 /* Every child adds itself to new process group
3266 * with pgid == pid_of_first_child_in_pipe */
3267 if (G.run_list_level == 1 && G_interactive_fd) {
3270 if (pgrp < 0) /* true for 1st process only */
3272 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3273 /* We do it in *every* child, not just first,
3275 tcsetpgrp(G_interactive_fd, pgrp);
3279 xmove_fd(nextin, 0);
3280 xmove_fd(pipefds[1], 1); /* write end */
3282 close(pipefds[0]); /* read end */
3283 /* Like bash, explicit redirects override pipes,
3284 * and the pipe fd is available for dup'ing. */
3285 if (setup_redirects(command, NULL))
3288 /* Restore default handlers just prior to exec */
3289 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3291 /* Stores to nommu_save list of env vars putenv'ed
3292 * (NOMMU, on MMU we don't need that) */
3293 /* cast away volatility... */
3294 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3295 /* pseudo_exec() does not return */
3298 /* parent or error */
3299 enable_restore_tty_pgrp_on_exit();
3301 /* Clean up after vforked child */
3302 clean_up_after_re_execute();
3303 free(nommu_save.argv);
3304 free_strings_and_unsetenv(nommu_save.new_env, 1);
3305 putenv_all(nommu_save.old_env);
3306 /* Free the pointers, but the strings themselves
3307 * are in environ now, don't use free_strings! */
3308 free(nommu_save.old_env);
3310 free(argv_expanded);
3311 argv_expanded = NULL;
3312 if (command->pid < 0) { /* [v]fork failed */
3313 /* Clearly indicate, was it fork or vfork */
3314 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3318 /* Second and next children need to know pid of first one */
3320 pi->pgrp = command->pid;
3326 if ((i + 1) < pi->num_cmds)
3327 close(pipefds[1]); /* write end */
3328 /* Pass read (output) pipe end to next iteration */
3329 nextin = pipefds[0];
3332 if (!pi->alive_cmds) {
3333 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3337 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3341 #ifndef debug_print_tree
3342 static void debug_print_tree(struct pipe *pi, int lvl)
3344 static const char *const PIPE[] = {
3350 static const char *RES[] = {
3351 [RES_NONE ] = "NONE" ,
3354 [RES_THEN ] = "THEN" ,
3355 [RES_ELIF ] = "ELIF" ,
3356 [RES_ELSE ] = "ELSE" ,
3359 #if ENABLE_HUSH_LOOPS
3360 [RES_FOR ] = "FOR" ,
3361 [RES_WHILE] = "WHILE",
3362 [RES_UNTIL] = "UNTIL",
3364 [RES_DONE ] = "DONE" ,
3366 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3369 #if ENABLE_HUSH_CASE
3370 [RES_CASE ] = "CASE" ,
3371 [RES_MATCH] = "MATCH",
3372 [RES_CASEI] = "CASEI",
3373 [RES_ESAC ] = "ESAC" ,
3375 [RES_XXXX ] = "XXXX" ,
3376 [RES_SNTX ] = "SNTX" ,
3378 static const char *const GRPTYPE[] = {
3381 #if ENABLE_HUSH_FUNCTIONS
3390 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3391 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3393 while (prn < pi->num_cmds) {
3394 struct command *command = &pi->cmds[prn];
3395 char **argv = command->argv;
3397 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3399 command->assignment_cnt);
3400 if (command->group) {
3401 fprintf(stderr, " group %s: (argv=%p)\n",
3402 GRPTYPE[command->grp_type],
3404 debug_print_tree(command->group, lvl+1);
3408 if (argv) while (*argv) {
3409 fprintf(stderr, " '%s'", *argv);
3412 fprintf(stderr, "\n");
3421 /* NB: called by pseudo_exec, and therefore must not modify any
3422 * global data until exec/_exit (we can be a child after vfork!) */
3423 static int run_list(struct pipe *pi)
3425 #if ENABLE_HUSH_CASE
3426 char *case_word = NULL;
3428 #if ENABLE_HUSH_LOOPS
3429 struct pipe *loop_top = NULL;
3430 char *for_varname = NULL;
3431 char **for_lcur = NULL;
3432 char **for_list = NULL;
3434 smallint last_followup;
3436 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3437 smalluint cond_code = 0;
3439 enum { cond_code = 0 };
3442 smallint rword; /* enum reserved_style */
3443 smallint last_rword; /* ditto */
3446 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3448 #if ENABLE_HUSH_LOOPS
3449 /* Check syntax for "for" */
3450 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3451 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3453 /* current word is FOR or IN (BOLD in comments below) */
3454 if (cpipe->next == NULL) {
3455 syntax_error("malformed for");
3456 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3459 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3460 if (cpipe->next->res_word == RES_DO)
3462 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3463 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3464 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3466 syntax_error("malformed for");
3467 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3473 /* Past this point, all code paths should jump to ret: label
3474 * in order to return, no direct "return" statements please.
3475 * This helps to ensure that no memory is leaked. */
3477 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3480 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3481 * We are saving state before entering outermost list ("while...done")
3482 * so that ctrl-Z will correctly background _entire_ outermost list,
3483 * not just a part of it (like "sleep 1 | exit 2") */
3484 if (++G.run_list_level == 1 && G_interactive_fd) {
3485 if (sigsetjmp(G.toplevel_jb, 1)) {
3486 /* ctrl-Z forked and we are parent; or ctrl-C.
3487 * Sighandler has longjmped us here */
3488 signal(SIGINT, SIG_IGN);
3489 signal(SIGTSTP, SIG_IGN);
3490 /* Restore level (we can be coming from deep inside
3492 G.run_list_level = 1;
3493 #if ENABLE_FEATURE_SH_STANDALONE
3494 if (G.nofork_save.saved) { /* if save area is valid */
3495 debug_printf_jobs("exiting nofork early\n");
3496 restore_nofork_data(&G.nofork_save);
3499 //// if (G.ctrl_z_flag) {
3500 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3501 //// * Remember this child as background job */
3502 //// insert_bg_job(pi);
3504 /* ctrl-C. We just stop doing whatever we were doing */
3507 USE_HUSH_LOOPS(loop_top = NULL;)
3508 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3512 //// /* ctrl-Z handler will store pid etc in pi */
3513 //// G.toplevel_list = pi;
3514 //// G.ctrl_z_flag = 0;
3515 #if ENABLE_FEATURE_SH_STANDALONE
3516 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3518 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3519 //// signal(SIGINT, handler_ctrl_c);
3525 last_rword = RES_XXXX;
3527 last_followup = PIPE_SEQ;
3528 rcode = G.last_exitcode;
3530 /* Go through list of pipes, (maybe) executing them. */
3531 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3535 IF_HAS_KEYWORDS(rword = pi->res_word;)
3536 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3537 rword, cond_code, last_rword);
3538 #if ENABLE_HUSH_LOOPS
3539 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3540 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3542 /* start of a loop: remember where loop starts */
3547 /* Still in the same "if...", "then..." or "do..." branch? */
3548 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3549 if ((rcode == 0 && last_followup == PIPE_OR)
3550 || (rcode != 0 && last_followup == PIPE_AND)
3552 /* It is "<true> || CMD" or "<false> && CMD"
3553 * and we should not execute CMD */
3554 debug_printf_exec("skipped cmd because of || or &&\n");
3555 last_followup = pi->followup;
3559 last_followup = pi->followup;
3560 IF_HAS_KEYWORDS(last_rword = rword;)
3563 if (rword == RES_THEN) {
3564 /* if false; then ... fi has exitcode 0! */
3565 G.last_exitcode = rcode = EXIT_SUCCESS;
3566 /* "if <false> THEN cmd": skip cmd */
3570 if (rword == RES_ELSE || rword == RES_ELIF) {
3571 /* "if <true> then ... ELSE/ELIF cmd":
3572 * skip cmd and all following ones */
3577 #if ENABLE_HUSH_LOOPS
3578 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3580 /* first loop through for */
3582 static const char encoded_dollar_at[] ALIGN1 = {
3583 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3584 }; /* encoded representation of "$@" */
3585 static const char *const encoded_dollar_at_argv[] = {
3586 encoded_dollar_at, NULL
3587 }; /* argv list with one element: "$@" */
3590 vals = (char**)encoded_dollar_at_argv;
3591 if (pi->next->res_word == RES_IN) {
3592 /* if no variable values after "in" we skip "for" */
3593 if (!pi->next->cmds[0].argv) {
3594 G.last_exitcode = rcode = EXIT_SUCCESS;
3595 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3598 vals = pi->next->cmds[0].argv;
3599 } /* else: "for var; do..." -> assume "$@" list */
3600 /* create list of variable values */
3601 debug_print_strings("for_list made from", vals);
3602 for_list = expand_strvec_to_strvec(vals);
3603 for_lcur = for_list;
3604 debug_print_strings("for_list", for_list);
3605 for_varname = pi->cmds[0].argv[0];
3606 pi->cmds[0].argv[0] = NULL;
3608 free(pi->cmds[0].argv[0]);
3610 /* "for" loop is over, clean up */
3614 pi->cmds[0].argv[0] = for_varname;
3617 /* Insert next value from for_lcur */
3618 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3619 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3620 pi->cmds[0].assignment_cnt = 1;
3622 if (rword == RES_IN) {
3623 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3625 if (rword == RES_DONE) {
3626 continue; /* "done" has no cmds too */
3629 #if ENABLE_HUSH_CASE
3630 if (rword == RES_CASE) {
3631 case_word = expand_strvec_to_string(pi->cmds->argv);
3634 if (rword == RES_MATCH) {
3637 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3639 /* all prev words didn't match, does this one match? */
3640 argv = pi->cmds->argv;
3642 char *pattern = expand_string_to_string(*argv);
3643 /* TODO: which FNM_xxx flags to use? */
3644 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3646 if (cond_code == 0) { /* match! we will execute this branch */
3647 free(case_word); /* make future "word)" stop */
3655 if (rword == RES_CASEI) { /* inside of a case branch */
3657 continue; /* not matched yet, skip this pipe */
3660 /* Just pressing <enter> in shell should check for jobs.
3661 * OTOH, in non-interactive shell this is useless
3662 * and only leads to extra job checks */
3663 if (pi->num_cmds == 0) {
3664 if (G_interactive_fd)
3665 goto check_jobs_and_continue;
3669 /* After analyzing all keywords and conditions, we decided
3670 * to execute this pipe. NB: have to do checkjobs(NULL)
3671 * after run_pipe to collect any background children,
3672 * even if list execution is to be stopped. */
3673 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3676 #if ENABLE_HUSH_LOOPS
3677 G.flag_break_continue = 0;
3679 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3681 /* We only ran a builtin: rcode is already known
3682 * and we don't need to wait for anything. */
3683 G.last_exitcode = rcode;
3684 debug_printf_exec(": builtin exitcode %d\n", rcode);
3685 check_and_run_traps(0);
3686 #if ENABLE_HUSH_LOOPS
3687 /* Was it "break" or "continue"? */
3688 if (G.flag_break_continue) {
3689 smallint fbc = G.flag_break_continue;
3690 /* We might fall into outer *loop*,
3691 * don't want to break it too */
3693 G.depth_break_continue--;
3694 if (G.depth_break_continue == 0)
3695 G.flag_break_continue = 0;
3696 /* else: e.g. "continue 2" should *break* once, *then* continue */
3697 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3698 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3699 goto check_jobs_and_break;
3700 /* "continue": simulate end of loop */
3705 } else if (pi->followup == PIPE_BG) {
3706 /* What does bash do with attempts to background builtins? */
3707 /* even bash 3.2 doesn't do that well with nested bg:
3708 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3709 * I'm NOT treating inner &'s as jobs */
3710 check_and_run_traps(0);
3712 if (G.run_list_level == 1)
3715 G.last_exitcode = rcode = EXIT_SUCCESS;
3716 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3719 if (G.run_list_level == 1 && G_interactive_fd) {
3720 /* Waits for completion, then fg's main shell */
3721 rcode = checkjobs_and_fg_shell(pi);
3722 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3723 check_and_run_traps(0);
3726 { /* This one just waits for completion */
3727 rcode = checkjobs(pi);
3728 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3729 check_and_run_traps(0);
3731 G.last_exitcode = rcode;
3735 /* Analyze how result affects subsequent commands */
3737 if (rword == RES_IF || rword == RES_ELIF)
3740 #if ENABLE_HUSH_LOOPS
3741 /* Beware of "while false; true; do ..."! */
3742 if (pi->next && pi->next->res_word == RES_DO) {
3743 if (rword == RES_WHILE) {
3745 /* "while false; do...done" - exitcode 0 */
3746 G.last_exitcode = rcode = EXIT_SUCCESS;
3747 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3748 goto check_jobs_and_break;
3751 if (rword == RES_UNTIL) {
3753 debug_printf_exec(": until expr is true: breaking\n");
3754 check_jobs_and_break:
3762 check_jobs_and_continue:
3767 //// if (G.ctrl_z_flag) {
3768 //// /* ctrl-Z forked somewhere in the past, we are the child,
3769 //// * and now we completed running the list. Exit. */
3775 //// if (!G.run_list_level && G_interactive_fd) {
3776 //// signal(SIGTSTP, SIG_IGN);
3777 //// signal(SIGINT, SIG_IGN);
3780 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3781 #if ENABLE_HUSH_LOOPS
3786 #if ENABLE_HUSH_CASE
3792 /* Select which version we will use */
3793 static int run_and_free_list(struct pipe *pi)
3796 debug_printf_exec("run_and_free_list entered\n");
3798 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3799 rcode = run_list(pi);
3801 /* free_pipe_list has the side effect of clearing memory.
3802 * In the long run that function can be merged with run_list,
3803 * but doing that now would hobble the debugging effort. */
3804 free_pipe_list(pi, /* indent: */ 0);
3805 debug_printf_exec("run_and_free_list return %d\n", rcode);
3810 static struct pipe *new_pipe(void)
3813 pi = xzalloc(sizeof(struct pipe));
3814 /*pi->followup = 0; - deliberately invalid value */
3815 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3819 /* Command (member of a pipe) is complete. The only possible error here
3820 * is out of memory, in which case xmalloc exits. */
3821 static int done_command(struct parse_context *ctx)
3823 /* The command is really already in the pipe structure, so
3824 * advance the pipe counter and make a new, null command. */
3825 struct pipe *pi = ctx->pipe;
3826 struct command *command = ctx->command;
3829 if (command->group == NULL
3830 && command->argv == NULL
3831 && command->redirects == NULL
3833 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3834 memset(command, 0, sizeof(*command)); /* paranoia */
3835 return pi->num_cmds;
3838 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3839 //debug_print_tree(ctx->list_head, 20);
3841 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3844 /* Only real trickiness here is that the uncommitted
3845 * command structure is not counted in pi->num_cmds. */
3846 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3847 command = &pi->cmds[pi->num_cmds];
3848 memset(command, 0, sizeof(*command));
3850 ctx->command = command;
3851 /* but ctx->pipe and ctx->list_head remain unchanged */
3853 return pi->num_cmds; /* used only for 0/nonzero check */
3856 static void done_pipe(struct parse_context *ctx, pipe_style type)
3860 debug_printf_parse("done_pipe entered, followup %d\n", type);
3861 /* Close previous command */
3862 not_null = done_command(ctx);
3863 ctx->pipe->followup = type;
3865 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3866 ctx->ctx_inverted = 0;
3867 ctx->pipe->res_word = ctx->ctx_res_w;
3870 /* Without this check, even just <enter> on command line generates
3871 * tree of three NOPs (!). Which is harmless but annoying.
3872 * IOW: it is safe to do it unconditionally.
3873 * RES_NONE case is for "for a in; do ..." (empty IN set)
3874 * and other cases to work. */
3877 || ctx->ctx_res_w == RES_FI
3878 || ctx->ctx_res_w == RES_DONE
3879 || ctx->ctx_res_w == RES_FOR
3880 || ctx->ctx_res_w == RES_IN
3881 || ctx->ctx_res_w == RES_ESAC
3885 debug_printf_parse("done_pipe: adding new pipe: "
3886 "not_null:%d ctx->ctx_res_w:%d\n",
3887 not_null, ctx->ctx_res_w);
3889 ctx->pipe->next = new_p;
3891 /* RES_THEN, RES_DO etc are "sticky" -
3892 * they remain set for commands inside if/while.
3893 * This is used to control execution.
3894 * RES_FOR and RES_IN are NOT sticky (needed to support
3895 * cases where variable or value happens to match a keyword):
3897 #if ENABLE_HUSH_LOOPS
3898 if (ctx->ctx_res_w == RES_FOR
3899 || ctx->ctx_res_w == RES_IN)
3900 ctx->ctx_res_w = RES_NONE;
3902 #if ENABLE_HUSH_CASE
3903 if (ctx->ctx_res_w == RES_MATCH)
3904 ctx->ctx_res_w = RES_CASEI;
3906 ctx->command = NULL; /* trick done_command below */
3907 /* Create the memory for command, roughly:
3908 * ctx->pipe->cmds = new struct command;
3909 * ctx->command = &ctx->pipe->cmds[0];
3912 //debug_print_tree(ctx->list_head, 10);
3914 debug_printf_parse("done_pipe return\n");
3917 static void initialize_context(struct parse_context *ctx)
3919 memset(ctx, 0, sizeof(*ctx));
3920 ctx->pipe = ctx->list_head = new_pipe();
3921 /* Create the memory for command, roughly:
3922 * ctx->pipe->cmds = new struct command;
3923 * ctx->command = &ctx->pipe->cmds[0];
3928 /* If a reserved word is found and processed, parse context is modified
3929 * and 1 is returned.
3932 struct reserved_combo {
3935 unsigned char assignment_flag;
3939 FLAG_END = (1 << RES_NONE ),
3941 FLAG_IF = (1 << RES_IF ),
3942 FLAG_THEN = (1 << RES_THEN ),
3943 FLAG_ELIF = (1 << RES_ELIF ),
3944 FLAG_ELSE = (1 << RES_ELSE ),
3945 FLAG_FI = (1 << RES_FI ),
3947 #if ENABLE_HUSH_LOOPS
3948 FLAG_FOR = (1 << RES_FOR ),
3949 FLAG_WHILE = (1 << RES_WHILE),
3950 FLAG_UNTIL = (1 << RES_UNTIL),
3951 FLAG_DO = (1 << RES_DO ),
3952 FLAG_DONE = (1 << RES_DONE ),
3953 FLAG_IN = (1 << RES_IN ),
3955 #if ENABLE_HUSH_CASE
3956 FLAG_MATCH = (1 << RES_MATCH),
3957 FLAG_ESAC = (1 << RES_ESAC ),
3959 FLAG_START = (1 << RES_XXXX ),
3962 static const struct reserved_combo* match_reserved_word(o_string *word)
3964 /* Mostly a list of accepted follow-up reserved words.
3965 * FLAG_END means we are done with the sequence, and are ready
3966 * to turn the compound list into a command.
3967 * FLAG_START means the word must start a new compound list.
3969 static const struct reserved_combo reserved_list[] = {
3971 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3972 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3973 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3974 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3975 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3976 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3978 #if ENABLE_HUSH_LOOPS
3979 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3980 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3981 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3982 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3983 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3984 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3986 #if ENABLE_HUSH_CASE
3987 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3988 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3991 const struct reserved_combo *r;
3993 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3994 if (strcmp(word->data, r->literal) == 0)
3999 static int reserved_word(o_string *word, struct parse_context *ctx)
4001 #if ENABLE_HUSH_CASE
4002 static const struct reserved_combo reserved_match = {
4003 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4006 const struct reserved_combo *r;
4008 r = match_reserved_word(word);
4012 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4013 #if ENABLE_HUSH_CASE
4014 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4015 /* "case word IN ..." - IN part starts first match part */
4016 r = &reserved_match;
4019 if (r->flag == 0) { /* '!' */
4020 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4021 syntax_error("! ! command");
4022 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
4024 ctx->ctx_inverted = 1;
4027 if (r->flag & FLAG_START) {
4028 struct parse_context *old;
4029 old = xmalloc(sizeof(*old));
4030 debug_printf_parse("push stack %p\n", old);
4031 *old = *ctx; /* physical copy */
4032 initialize_context(ctx);
4034 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4035 syntax_error_at(word->data);
4036 ctx->ctx_res_w = RES_SNTX;
4039 ctx->ctx_res_w = r->res;
4040 ctx->old_flag = r->flag;
4041 if (ctx->old_flag & FLAG_END) {
4042 struct parse_context *old;
4043 done_pipe(ctx, PIPE_SEQ);
4044 debug_printf_parse("pop stack %p\n", ctx->stack);
4046 old->command->group = ctx->list_head;
4047 old->command->grp_type = GRP_NORMAL;
4049 o_addstr(&old->as_string, ctx->as_string.data);
4050 o_free_unsafe(&ctx->as_string);
4051 old->command->group_as_string = xstrdup(old->as_string.data);
4052 debug_printf_parse("pop, remembering as:'%s'\n",
4053 old->command->group_as_string);
4055 *ctx = *old; /* physical copy */
4058 word->o_assignment = r->assignment_flag;
4063 /* Word is complete, look at it and update parsing context.
4064 * Normal return is 0. Syntax errors return 1.
4065 * Note: on return, word is reset, but not o_free'd!
4067 static int done_word(o_string *word, struct parse_context *ctx)
4069 struct command *command = ctx->command;
4071 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4072 if (word->length == 0 && word->o_quoted == 0) {
4073 debug_printf_parse("done_word return 0: true null, ignored\n");
4077 if (ctx->pending_redirect) {
4078 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4079 * only if run as "bash", not "sh" */
4080 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4082 * ...the word that follows the redirection operator
4083 * shall be subjected to tilde expansion, parameter expansion,
4084 * command substitution, arithmetic expansion, and quote
4085 * removal. Pathname expansion shall not be performed
4086 * on the word by a non-interactive shell; an interactive
4087 * shell may perform it, but shall do so only when
4088 * the expansion would result in one word."
4090 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4091 /* Cater for >\file case:
4092 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4093 * Same with heredocs:
4094 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4096 unbackslash(ctx->pending_redirect->rd_filename);
4097 /* Is it <<"HEREDOC"? */
4098 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4101 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4103 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4104 ctx->pending_redirect = NULL;
4106 /* If this word wasn't an assignment, next ones definitely
4107 * can't be assignments. Even if they look like ones. */
4108 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4109 && word->o_assignment != WORD_IS_KEYWORD
4111 word->o_assignment = NOT_ASSIGNMENT;
4113 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4114 command->assignment_cnt++;
4115 word->o_assignment = MAYBE_ASSIGNMENT;
4118 if (command->group) {
4119 /* "{ echo foo; } echo bar" - bad */
4120 /* NB: bash allows e.g.:
4121 * if true; then { echo foo; } fi
4122 * while if false; then false; fi do break; done
4124 * while if false; then false; fi; do; break; done
4126 syntax_error_at(word->data);
4127 debug_printf_parse("done_word return 1: syntax error, "
4128 "groups and arglists don't mix\n");
4132 # if ENABLE_HUSH_CASE
4133 if (ctx->ctx_dsemicolon
4134 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4136 /* already done when ctx_dsemicolon was set to 1: */
4137 /* ctx->ctx_res_w = RES_MATCH; */
4138 ctx->ctx_dsemicolon = 0;
4141 if (!command->argv /* if it's the first word... */
4142 # if ENABLE_HUSH_LOOPS
4143 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4144 && ctx->ctx_res_w != RES_IN
4147 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4148 if (reserved_word(word, ctx)) {
4149 o_reset_to_empty_unquoted(word);
4150 debug_printf_parse("done_word return %d\n",
4151 (ctx->ctx_res_w == RES_SNTX));
4152 return (ctx->ctx_res_w == RES_SNTX);
4156 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4157 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4158 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4159 /* (otherwise it's known to be not empty and is already safe) */
4161 /* exclude "$@" - it can expand to no word despite "" */
4162 char *p = word->data;
4163 while (p[0] == SPECIAL_VAR_SYMBOL
4164 && (p[1] & 0x7f) == '@'
4165 && p[2] == SPECIAL_VAR_SYMBOL
4169 if (p == word->data || p[0] != '\0') {
4170 /* saw no "$@", or not only "$@" but some
4171 * real text is there too */
4172 /* insert "empty variable" reference, this makes
4173 * e.g. "", $empty"" etc to not disappear */
4174 o_addchr(word, SPECIAL_VAR_SYMBOL);
4175 o_addchr(word, SPECIAL_VAR_SYMBOL);
4178 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4179 //SEGV, but good idea.
4180 // command->argv = add_string_to_strings(command->argv, word->data);
4181 // word->data = NULL;
4182 // word->length = 0;
4183 debug_print_strings("word appended to argv", command->argv);
4186 #if ENABLE_HUSH_LOOPS
4187 if (ctx->ctx_res_w == RES_FOR) {
4189 || !is_well_formed_var_name(command->argv[0], '\0')
4191 /* bash says just "not a valid identifier" */
4192 syntax_error("not a valid identifier in for");
4195 /* Force FOR to have just one word (variable name) */
4196 /* NB: basically, this makes hush see "for v in ..."
4197 * syntax as if it is "for v; in ...". FOR and IN become
4198 * two pipe structs in parse tree. */
4199 done_pipe(ctx, PIPE_SEQ);
4202 #if ENABLE_HUSH_CASE
4203 /* Force CASE to have just one word */
4204 if (ctx->ctx_res_w == RES_CASE) {
4205 done_pipe(ctx, PIPE_SEQ);
4209 o_reset_to_empty_unquoted(word);
4211 debug_printf_parse("done_word return 0\n");
4216 /* Peek ahead in the input to find out if we have a "&n" construct,
4217 * as in "2>&1", that represents duplicating a file descriptor.
4219 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4220 * REDIRFD_SYNTAX_ERR if syntax error,
4221 * REDIRFD_TO_FILE if no & was seen,
4222 * or the number found.
4225 #define parse_redir_right_fd(as_string, input) \
4226 parse_redir_right_fd(input)
4228 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4234 return REDIRFD_TO_FILE;
4236 ch = i_getch(input); /* get the & */
4237 nommu_addchr(as_string, ch);
4240 ch = i_getch(input);
4241 nommu_addchr(as_string, ch);
4242 return REDIRFD_CLOSE;
4246 while (ch != EOF && isdigit(ch)) {
4247 d = d*10 + (ch-'0');
4249 ch = i_getch(input);
4250 nommu_addchr(as_string, ch);
4255 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4257 bb_error_msg("ambiguous redirect");
4258 return REDIRFD_SYNTAX_ERR;
4261 /* Return code is 0 normal, 1 if a syntax error is detected
4263 static int parse_redirect(struct parse_context *ctx,
4266 struct in_str *input)
4268 struct command *command = ctx->command;
4269 struct redir_struct *redir;
4270 struct redir_struct **redirp;
4273 dup_num = REDIRFD_TO_FILE;
4274 if (style != REDIRECT_HEREDOC) {
4275 /* Check for a '>&1' type redirect */
4276 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4277 if (dup_num == REDIRFD_SYNTAX_ERR)
4280 int ch = i_peek(input);
4281 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4282 if (dup_num) { /* <<-... */
4283 ch = i_getch(input);
4284 nommu_addchr(&ctx->as_string, ch);
4289 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4290 int ch = i_peek(input);
4292 /* >|FILE redirect ("clobbering" >).
4293 * Since we do not support "set -o noclobber" yet,
4294 * >| and > are the same for now. Just eat |.
4296 ch = i_getch(input);
4297 nommu_addchr(&ctx->as_string, ch);
4301 /* Create a new redir_struct and append it to the linked list */
4302 redirp = &command->redirects;
4303 while ((redir = *redirp) != NULL) {
4304 redirp = &(redir->next);
4306 *redirp = redir = xzalloc(sizeof(*redir));
4307 /* redir->next = NULL; */
4308 /* redir->rd_filename = NULL; */
4309 redir->rd_type = style;
4310 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4312 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4313 redir_table[style].descrip);
4315 redir->rd_dup = dup_num;
4316 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4317 /* Erik had a check here that the file descriptor in question
4318 * is legit; I postpone that to "run time"
4319 * A "-" representation of "close me" shows up as a -3 here */
4320 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4321 redir->rd_fd, redir->rd_dup);
4323 /* Set ctx->pending_redirect, so we know what to do at the
4324 * end of the next parsed word. */
4325 ctx->pending_redirect = redir;
4330 /* If a redirect is immediately preceded by a number, that number is
4331 * supposed to tell which file descriptor to redirect. This routine
4332 * looks for such preceding numbers. In an ideal world this routine
4333 * needs to handle all the following classes of redirects...
4334 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4335 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4336 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4337 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4339 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4341 * ... If n is quoted, the number shall not be recognized as part of
4342 * the redirection expression. For example:
4344 * writes the character 2 into file a"
4345 * We are getting it right by setting ->o_quoted on any \<char>
4347 * A -1 return means no valid number was found,
4348 * the caller should use the appropriate default for this redirection.
4350 static int redirect_opt_num(o_string *o)
4354 if (o->data == NULL)
4356 num = bb_strtou(o->data, NULL, 10);
4357 if (errno || num < 0)
4359 o_reset_to_empty_unquoted(o);
4364 #define fetch_till_str(as_string, input, word, skip_tabs) \
4365 fetch_till_str(input, word, skip_tabs)
4367 static char *fetch_till_str(o_string *as_string,
4368 struct in_str *input,
4372 o_string heredoc = NULL_O_STRING;
4378 ch = i_getch(input);
4379 nommu_addchr(as_string, ch);
4381 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4382 heredoc.data[past_EOL] = '\0';
4383 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4384 return heredoc.data;
4387 o_addchr(&heredoc, ch);
4388 past_EOL = heredoc.length;
4391 ch = i_getch(input);
4392 nommu_addchr(as_string, ch);
4393 } while (skip_tabs && ch == '\t');
4394 } while (ch == '\n');
4397 o_free_unsafe(&heredoc);
4400 o_addchr(&heredoc, ch);
4401 nommu_addchr(as_string, ch);
4405 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4406 * and load them all. There should be exactly heredoc_cnt of them.
4408 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4410 struct pipe *pi = ctx->list_head;
4412 while (pi && heredoc_cnt) {
4414 struct command *cmd = pi->cmds;
4416 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4418 cmd->argv ? cmd->argv[0] : "NONE");
4419 for (i = 0; i < pi->num_cmds; i++) {
4420 struct redir_struct *redir = cmd->redirects;
4422 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4423 i, cmd->argv ? cmd->argv[0] : "NONE");
4425 if (redir->rd_type == REDIRECT_HEREDOC) {
4428 redir->rd_type = REDIRECT_HEREDOC2;
4429 /* redir->dup is (ab)used to indicate <<- */
4430 p = fetch_till_str(&ctx->as_string, input,
4431 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4433 syntax_error("unexpected EOF in here document");
4436 free(redir->rd_filename);
4437 redir->rd_filename = p;
4440 redir = redir->next;
4447 /* Should be 0. If it isn't, it's a parse error */
4449 bb_error_msg_and_die("heredoc BUG 2");
4456 #define parse_stream(pstring, input, end_trigger) \
4457 parse_stream(input, end_trigger)
4459 static struct pipe *parse_stream(char **pstring,
4460 struct in_str *input,
4462 static void parse_and_run_string(const char *s);
4464 #if ENABLE_HUSH_TICK
4465 static FILE *generate_stream_from_string(const char *s)
4468 int pid, channel[2];
4471 pid = BB_MMU ? fork() : vfork();
4473 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4475 if (pid == 0) { /* child */
4476 disable_restore_tty_pgrp_on_exit();
4477 /* Process substitution is not considered to be usual
4478 * 'command execution'.
4479 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4486 close(channel[0]); /* NB: close _first_, then move fd! */
4487 xmove_fd(channel[1], 1);
4488 /* Prevent it from trying to handle ctrl-z etc */
4489 USE_HUSH_JOB(G.run_list_level = 1;)
4491 reset_traps_to_defaults();
4492 parse_and_run_string(s);
4493 _exit(G.last_exitcode);
4495 /* We re-execute after vfork on NOMMU. This makes this script safe:
4496 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4497 * huge=`cat BIG` # was blocking here forever
4500 re_execute_shell(s, 0);
4505 enable_restore_tty_pgrp_on_exit();
4506 clean_up_after_re_execute();
4508 pf = fdopen(channel[0], "r");
4512 /* Return code is exit status of the process that is run. */
4513 static int process_command_subs(o_string *dest, const char *s)
4516 struct in_str pipe_str;
4519 pf = generate_stream_from_string(s);
4522 close_on_exec_on(fileno(pf));
4524 /* Now send results of command back into original context */
4525 setup_file_in_str(&pipe_str, pf);
4527 while ((ch = i_getch(&pipe_str)) != EOF) {
4533 o_addchr(dest, '\n');
4536 o_addQchr(dest, ch);
4539 debug_printf("done reading from pipe, pclose()ing\n");
4540 /* Note: we got EOF, and we just close the read end of the pipe.
4541 * We do not wait for the `cmd` child to terminate. bash and ash do.
4543 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4544 * `false`; echo $? - bash outputs "1"
4547 debug_printf("closed FILE from child. return 0\n");
4552 static int parse_group(o_string *dest, struct parse_context *ctx,
4553 struct in_str *input, int ch)
4555 /* dest contains characters seen prior to ( or {.
4556 * Typically it's empty, but for function defs,
4557 * it contains function name (without '()'). */
4558 struct pipe *pipe_list;
4560 struct command *command = ctx->command;
4562 debug_printf_parse("parse_group entered\n");
4563 #if ENABLE_HUSH_FUNCTIONS
4565 if (!dest->o_quoted) {
4567 done_word(dest, ctx);
4569 goto skip; /* (... */
4570 if (command->argv[1]) { /* word word ... (... */
4571 syntax_error("unexpected character (");
4574 /* it is "word(..." or "word (..." */
4576 ch = i_getch(input);
4577 while (ch == ' ' || ch == '\t');
4579 syntax_error("unexpected character X");
4583 ch = i_getch(input);
4584 while (ch == ' ' || ch == '\t' || ch == '\n');
4586 syntax_error("unexpected character X");
4589 command->grp_type = GRP_FUNCTION;
4594 if (command->argv /* word [word]{... */
4595 || dest->length /* word{... */
4596 || dest->o_quoted /* ""{... */
4599 debug_printf_parse("parse_group return 1: "
4600 "syntax error, groups and arglists don't mix\n");
4604 #if ENABLE_HUSH_FUNCTIONS
4610 command->grp_type = GRP_SUBSHELL;
4615 char *as_string = NULL;
4617 pipe_list = parse_stream(&as_string, input, endch);
4620 o_addstr(&ctx->as_string, as_string);
4622 /* empty ()/{} or parse error? */
4623 if (!pipe_list || pipe_list == ERR_PTR) {
4628 debug_printf_parse("parse_group return 1: "
4629 "parse_stream returned %p\n", pipe_list);
4632 command->group = pipe_list;
4634 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4635 command->group_as_string = as_string;
4636 debug_printf_parse("end of group, remembering as:'%s'\n",
4637 command->group_as_string);
4640 debug_printf_parse("parse_group return 0\n");
4642 /* command remains "open", available for possible redirects */
4645 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4646 /* Subroutines for copying $(...) and `...` things */
4647 static void add_till_backquote(o_string *dest, struct in_str *input);
4649 static void add_till_single_quote(o_string *dest, struct in_str *input)
4652 int ch = i_getch(input);
4654 syntax_error_unterm_ch('\'');
4655 /*xfunc_die(); - redundant */
4662 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4663 static void add_till_double_quote(o_string *dest, struct in_str *input)
4666 int ch = i_getch(input);
4668 syntax_error_unterm_ch('"');
4669 /*xfunc_die(); - redundant */
4673 if (ch == '\\') { /* \x. Copy both chars. */
4675 ch = i_getch(input);
4679 add_till_backquote(dest, input);
4683 //if (ch == '$') ...
4686 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4688 * "Within the backquoted style of command substitution, backslash
4689 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4690 * The search for the matching backquote shall be satisfied by the first
4691 * backquote found without a preceding backslash; during this search,
4692 * if a non-escaped backquote is encountered within a shell comment,
4693 * a here-document, an embedded command substitution of the $(command)
4694 * form, or a quoted string, undefined results occur. A single-quoted
4695 * or double-quoted string that begins, but does not end, within the
4696 * "`...`" sequence produces undefined results."
4698 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4700 static void add_till_backquote(o_string *dest, struct in_str *input)
4703 int ch = i_getch(input);
4705 syntax_error_unterm_ch('`');
4706 /*xfunc_die(); - redundant */
4711 /* \x. Copy both chars unless it is \` */
4712 int ch2 = i_getch(input);
4714 syntax_error_unterm_ch('`');
4715 /*xfunc_die(); - redundant */
4717 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4724 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4725 * quoting and nested ()s.
4726 * "With the $(command) style of command substitution, all characters
4727 * following the open parenthesis to the matching closing parenthesis
4728 * constitute the command. Any valid shell script can be used for command,
4729 * except a script consisting solely of redirections which produces
4730 * unspecified results."
4732 * echo $(echo '(TEST)' BEST) (TEST) BEST
4733 * echo $(echo 'TEST)' BEST) TEST) BEST
4734 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4736 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4740 int ch = i_getch(input);
4742 syntax_error_unterm_ch(')');
4743 /*xfunc_die(); - redundant */
4751 if (i_peek(input) == ')') {
4759 add_till_single_quote(dest, input);
4764 add_till_double_quote(dest, input);
4769 /* \x. Copy verbatim. Important for \(, \) */
4770 ch = i_getch(input);
4772 syntax_error_unterm_ch(')');
4773 /*xfunc_die(); - redundant */
4780 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4782 /* Return code: 0 for OK, 1 for syntax error */
4784 #define handle_dollar(as_string, dest, input) \
4785 handle_dollar(dest, input)
4787 static int handle_dollar(o_string *as_string,
4789 struct in_str *input)
4792 int ch = i_peek(input); /* first character after the $ */
4793 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4795 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4797 ch = i_getch(input);
4798 nommu_addchr(as_string, ch);
4800 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4802 debug_printf_parse(": '%c'\n", ch);
4803 o_addchr(dest, ch | quote_mask);
4806 if (!isalnum(ch) && ch != '_')
4808 ch = i_getch(input);
4809 nommu_addchr(as_string, ch);
4811 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4812 } else if (isdigit(ch)) {
4814 ch = i_getch(input);
4815 nommu_addchr(as_string, ch);
4816 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4817 debug_printf_parse(": '%c'\n", ch);
4818 o_addchr(dest, ch | quote_mask);
4819 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4820 } else switch (ch) {
4822 case '!': /* last bg pid */
4823 case '?': /* last exit code */
4824 case '#': /* number of args */
4825 case '*': /* args */
4826 case '@': /* args */
4827 goto make_one_char_var;
4829 bool first_char, all_digits;
4831 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4832 ch = i_getch(input);
4833 nommu_addchr(as_string, ch);
4834 /* XXX maybe someone will try to escape the '}' */
4839 ch = i_getch(input);
4840 nommu_addchr(as_string, ch);
4846 /* ${#var}: length of var contents */
4848 else if (isdigit(ch)) {
4855 && ( (all_digits && !isdigit(ch))
4856 || (!all_digits && !isalnum(ch) && ch != '_')
4859 /* handle parameter expansions
4860 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4865 case ':': /* null modifier */
4866 if (expansion == 0) {
4867 debug_printf_parse(": null modifier\n");
4872 case '#': /* remove prefix */
4873 case '%': /* remove suffix */
4874 if (expansion == 0) {
4875 debug_printf_parse(": remove suffix/prefix\n");
4880 case '-': /* default value */
4881 case '=': /* assign default */
4882 case '+': /* alternative */
4883 case '?': /* error indicate */
4884 debug_printf_parse(": parameter expansion\n");
4889 syntax_error_unterm_str("${name}");
4890 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4895 debug_printf_parse(": '%c'\n", ch);
4896 o_addchr(dest, ch | quote_mask);
4900 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4903 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4908 ch = i_getch(input);
4909 nommu_addchr(as_string, ch);
4910 # if ENABLE_SH_MATH_SUPPORT
4911 if (i_peek(input) == '(') {
4912 ch = i_getch(input);
4913 nommu_addchr(as_string, ch);
4914 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4915 o_addchr(dest, /*quote_mask |*/ '+');
4919 add_till_closing_paren(dest, input, true);
4922 o_addstr(as_string, dest->data + pos);
4923 o_addchr(as_string, ')');
4924 o_addchr(as_string, ')');
4927 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4931 # if ENABLE_HUSH_TICK
4932 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4933 o_addchr(dest, quote_mask | '`');
4937 add_till_closing_paren(dest, input, false);
4940 o_addstr(as_string, dest->data + pos);
4941 o_addchr(as_string, '`');
4944 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4950 ch = i_getch(input);
4951 nommu_addchr(as_string, ch);
4953 if (isalnum(ch)) { /* it's $_name or $_123 */
4959 /* $_ Shell or shell script name; or last cmd name */
4960 /* $- Option flags set by set builtin or shell options (-i etc) */
4962 o_addQchr(dest, '$');
4964 debug_printf_parse("handle_dollar return 0\n");
4969 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4970 parse_stream_dquoted(dest, input, dquote_end)
4972 static int parse_stream_dquoted(o_string *as_string,
4974 struct in_str *input,
4981 ch = i_getch(input);
4983 nommu_addchr(as_string, ch);
4984 if (ch == dquote_end) { /* may be only '"' or EOF */
4985 if (dest->o_assignment == NOT_ASSIGNMENT)
4986 dest->o_escape ^= 1;
4987 debug_printf_parse("parse_stream_dquoted return 0\n");
4990 /* note: can't move it above ch == dquote_end check! */
4992 syntax_error_unterm_ch('"');
4993 /*xfunc_die(); - redundant */
4997 next = i_peek(input);
4999 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5000 ch, ch, dest->o_escape);
5003 syntax_error("\\<eof>");
5007 * "The backslash retains its special meaning [in "..."]
5008 * only when followed by one of the following characters:
5009 * $, `, ", \, or <newline>. A double quote may be quoted
5010 * within double quotes by preceding it with a backslash.
5012 if (strchr("$`\"\\", next) != NULL) {
5013 o_addqchr(dest, i_getch(input));
5015 o_addqchr(dest, '\\');
5020 if (handle_dollar(as_string, dest, input) != 0) {
5021 debug_printf_parse("parse_stream_dquoted return 1: "
5022 "handle_dollar returned non-0\n");
5027 #if ENABLE_HUSH_TICK
5029 //int pos = dest->length;
5030 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5031 o_addchr(dest, 0x80 | '`');
5032 add_till_backquote(dest, input);
5033 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5034 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5038 o_addQchr(dest, ch);
5040 && (dest->o_assignment == MAYBE_ASSIGNMENT
5041 || dest->o_assignment == WORD_IS_KEYWORD)
5042 && is_well_formed_var_name(dest->data, '=')
5044 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5050 * Scan input until EOF or end_trigger char.
5051 * Return a list of pipes to execute, or NULL on EOF
5052 * or if end_trigger character is met.
5053 * On syntax error, exit is shell is not interactive,
5054 * reset parsing machinery and start parsing anew,
5055 * or return ERR_PTR.
5057 static struct pipe *parse_stream(char **pstring,
5058 struct in_str *input,
5061 struct parse_context ctx;
5062 o_string dest = NULL_O_STRING;
5066 /* Double-quote state is handled in the state variable is_in_dquote.
5067 * A single-quote triggers a bypass of the main loop until its mate is
5068 * found. When recursing, quote state is passed in via dest->o_escape.
5070 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5071 end_trigger ? : 'X');
5073 G.ifs = get_local_var_value("IFS");
5078 #if ENABLE_HUSH_INTERACTIVE
5079 input->promptmode = 0; /* PS1 */
5081 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5082 initialize_context(&ctx);
5087 const char *is_special;
5091 redir_type redir_style;
5094 /* dest.o_quoted = 1; - already is (see below) */
5095 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5098 /* We reached closing '"' */
5101 ch = i_getch(input);
5102 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5103 ch, ch, dest.o_escape);
5108 syntax_error_unterm_str("here document");
5111 if (done_word(&dest, &ctx)) {
5115 done_pipe(&ctx, PIPE_SEQ);
5117 /* If we got nothing... */
5118 /* (this makes bare "&" cmd a no-op.
5119 * bash says: "syntax error near unexpected token '&'") */
5120 if (pi->num_cmds == 0
5121 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5123 free_pipe_list(pi, 0);
5126 debug_printf_parse("parse_stream return %p\n", pi);
5128 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5130 *pstring = ctx.as_string.data;
5132 o_free_unsafe(&ctx.as_string);
5136 nommu_addchr(&ctx.as_string, ch);
5137 is_ifs = strchr(G.ifs, ch);
5138 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5139 "\\$\"" USE_HUSH_TICK("`") /* always special */
5142 if (!is_special && !is_ifs) { /* ordinary char */
5143 o_addQchr(&dest, ch);
5144 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5145 || dest.o_assignment == WORD_IS_KEYWORD)
5147 && is_well_formed_var_name(dest.data, '=')
5149 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5155 if (done_word(&dest, &ctx)) {
5159 #if ENABLE_HUSH_CASE
5160 /* "case ... in <newline> word) ..." -
5161 * newlines are ignored (but ';' wouldn't be) */
5162 if (ctx.command->argv == NULL
5163 && ctx.ctx_res_w == RES_MATCH
5168 /* Treat newline as a command separator. */
5169 done_pipe(&ctx, PIPE_SEQ);
5170 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5172 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5177 dest.o_assignment = MAYBE_ASSIGNMENT;
5179 /* note: if (is_ifs) continue;
5180 * will still trigger for us */
5183 if (end_trigger && end_trigger == ch
5184 && (heredoc_cnt == 0 || end_trigger != ';')
5186 //TODO: disallow "{ cmd }" without semicolon
5188 /* This is technically valid:
5189 * { cat <<HERE; }; echo Ok
5194 * but we don't support this.
5195 * We require heredoc to be in enclosing {}/(),
5198 syntax_error_unterm_str("here document");
5201 if (done_word(&dest, &ctx)) {
5204 done_pipe(&ctx, PIPE_SEQ);
5205 dest.o_assignment = MAYBE_ASSIGNMENT;
5206 /* Do we sit outside of any if's, loops or case's? */
5208 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5210 debug_printf_parse("parse_stream return %p: "
5211 "end_trigger char found\n",
5215 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5217 *pstring = ctx.as_string.data;
5219 o_free_unsafe(&ctx.as_string);
5221 return ctx.list_head;
5229 next = i_peek(input);
5232 /* Catch <, > before deciding whether this word is
5233 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5236 redir_fd = redirect_opt_num(&dest);
5237 if (done_word(&dest, &ctx)) {
5240 redir_style = REDIRECT_OVERWRITE;
5242 redir_style = REDIRECT_APPEND;
5243 ch = i_getch(input);
5244 nommu_addchr(&ctx.as_string, ch);
5247 else if (next == '(') {
5248 syntax_error(">(process) not supported");
5252 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5254 continue; /* back to top of while (1) */
5256 redir_fd = redirect_opt_num(&dest);
5257 if (done_word(&dest, &ctx)) {
5260 redir_style = REDIRECT_INPUT;
5262 redir_style = REDIRECT_HEREDOC;
5264 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5265 ch = i_getch(input);
5266 nommu_addchr(&ctx.as_string, ch);
5267 } else if (next == '>') {
5268 redir_style = REDIRECT_IO;
5269 ch = i_getch(input);
5270 nommu_addchr(&ctx.as_string, ch);
5273 else if (next == '(') {
5274 syntax_error("<(process) not supported");
5278 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5280 continue; /* back to top of while (1) */
5283 if (dest.o_assignment == MAYBE_ASSIGNMENT
5284 /* check that we are not in word in "a=1 2>word b=1": */
5285 && !ctx.pending_redirect
5287 /* ch is a special char and thus this word
5288 * cannot be an assignment */
5289 dest.o_assignment = NOT_ASSIGNMENT;
5294 if (dest.length == 0) {
5297 if (ch == EOF || ch == '\n')
5300 /* note: we do not add it to &ctx.as_string */
5302 nommu_addchr(&ctx.as_string, '\n');
5304 o_addQchr(&dest, ch);
5309 syntax_error("\\<eof>");
5312 o_addchr(&dest, '\\');
5313 ch = i_getch(input);
5314 nommu_addchr(&ctx.as_string, ch);
5315 o_addchr(&dest, ch);
5316 /* Example: echo Hello \2>file
5317 * we need to know that word 2 is quoted */
5321 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5322 debug_printf_parse("parse_stream parse error: "
5323 "handle_dollar returned non-0\n");
5330 ch = i_getch(input);
5332 syntax_error_unterm_ch('\'');
5333 /*xfunc_die(); - redundant */
5335 nommu_addchr(&ctx.as_string, ch);
5338 if (dest.o_assignment == NOT_ASSIGNMENT)
5339 o_addqchr(&dest, ch);
5341 o_addchr(&dest, ch);
5346 is_in_dquote ^= 1; /* invert */
5347 if (dest.o_assignment == NOT_ASSIGNMENT)
5350 #if ENABLE_HUSH_TICK
5355 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5356 o_addchr(&dest, '`');
5360 add_till_backquote(&dest, input);
5362 o_addstr(&ctx.as_string, dest.data + pos);
5363 o_addchr(&ctx.as_string, '`');
5365 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5366 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5371 #if ENABLE_HUSH_CASE
5374 if (done_word(&dest, &ctx)) {
5377 done_pipe(&ctx, PIPE_SEQ);
5378 #if ENABLE_HUSH_CASE
5379 /* Eat multiple semicolons, detect
5380 * whether it means something special */
5385 ch = i_getch(input);
5386 nommu_addchr(&ctx.as_string, ch);
5387 if (ctx.ctx_res_w == RES_CASEI) {
5388 ctx.ctx_dsemicolon = 1;
5389 ctx.ctx_res_w = RES_MATCH;
5395 /* We just finished a cmd. New one may start
5396 * with an assignment */
5397 dest.o_assignment = MAYBE_ASSIGNMENT;
5400 if (done_word(&dest, &ctx)) {
5404 ch = i_getch(input);
5405 nommu_addchr(&ctx.as_string, ch);
5406 done_pipe(&ctx, PIPE_AND);
5408 done_pipe(&ctx, PIPE_BG);
5412 if (done_word(&dest, &ctx)) {
5415 #if ENABLE_HUSH_CASE
5416 if (ctx.ctx_res_w == RES_MATCH)
5417 break; /* we are in case's "word | word)" */
5419 if (next == '|') { /* || */
5420 ch = i_getch(input);
5421 nommu_addchr(&ctx.as_string, ch);
5422 done_pipe(&ctx, PIPE_OR);
5424 /* we could pick up a file descriptor choice here
5425 * with redirect_opt_num(), but bash doesn't do it.
5426 * "echo foo 2| cat" yields "foo 2". */
5431 #if ENABLE_HUSH_CASE
5432 /* "case... in [(]word)..." - skip '(' */
5433 if (ctx.ctx_res_w == RES_MATCH
5434 && ctx.command->argv == NULL /* not (word|(... */
5435 && dest.length == 0 /* not word(... */
5436 && dest.o_quoted == 0 /* not ""(... */
5442 if (parse_group(&dest, &ctx, input, ch) != 0) {
5447 #if ENABLE_HUSH_CASE
5448 if (ctx.ctx_res_w == RES_MATCH)
5452 /* proper use of this character is caught by end_trigger:
5453 * if we see {, we call parse_group(..., end_trigger='}')
5454 * and it will match } earlier (not here). */
5455 syntax_error("unexpected } or )");
5459 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5465 struct parse_context *pctx;
5466 IF_HAS_KEYWORDS(struct parse_context *p2;)
5468 /* Clean up allocated tree.
5469 * Samples for finding leaks on syntax error recovery path.
5470 * Run them from interactive shell, watch pmap `pidof hush`.
5471 * while if false; then false; fi do break; done
5473 * while if false; then false; fi; do break; fi
5474 * Samples to catch leaks at execution:
5475 * while if (true | {true;}); then echo ok; fi; do break; done
5476 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5480 /* Update pipe/command counts,
5481 * otherwise freeing may miss some */
5482 done_pipe(pctx, PIPE_SEQ);
5483 debug_printf_clean("freeing list %p from ctx %p\n",
5484 pctx->list_head, pctx);
5485 debug_print_tree(pctx->list_head, 0);
5486 free_pipe_list(pctx->list_head, 0);
5487 debug_printf_clean("freed list %p\n", pctx->list_head);
5489 o_free_unsafe(&pctx->as_string);
5491 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5495 IF_HAS_KEYWORDS(pctx = p2;)
5496 } while (HAS_KEYWORDS && pctx);
5497 /* Free text, clear all dest fields */
5499 /* If we are not in top-level parse, we return,
5500 * our caller will propagate error.
5502 if (end_trigger != ';') {
5509 /* Discard cached input, force prompt */
5511 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5516 /* Executing from string: eval, sh -c '...'
5517 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5518 * end_trigger controls how often we stop parsing
5519 * NUL: parse all, execute, return
5520 * ';': parse till ';' or newline, execute, repeat till EOF
5522 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5525 struct pipe *pipe_list;
5527 pipe_list = parse_stream(NULL, inp, end_trigger);
5528 if (!pipe_list) /* EOF */
5530 debug_print_tree(pipe_list, 0);
5531 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5532 run_and_free_list(pipe_list);
5536 static void parse_and_run_string(const char *s)
5538 struct in_str input;
5539 setup_string_in_str(&input, s);
5540 parse_and_run_stream(&input, '\0');
5543 static void parse_and_run_file(FILE *f)
5545 struct in_str input;
5546 setup_file_in_str(&input, f);
5547 parse_and_run_stream(&input, ';');
5550 /* Called a few times only (or even once if "sh -c") */
5551 static void block_signals(int second_time)
5556 mask = (1 << SIGQUIT);
5557 if (G_interactive_fd) {
5561 //TODO | (1 << SIGHUP)
5563 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5568 G.non_DFL_mask = mask;
5571 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5575 sigaddset(&G.blocked_set, sig);
5579 sigdelset(&G.blocked_set, SIGCHLD);
5581 sigprocmask(SIG_SETMASK, &G.blocked_set,
5582 second_time ? NULL : &G.inherited_set);
5583 /* POSIX allows shell to re-enable SIGCHLD
5584 * even if it was SIG_IGN on entry */
5585 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5587 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5592 static void maybe_set_to_sigexit(int sig)
5594 void (*handler)(int);
5595 /* non_DFL_mask'ed signals are, well, masked,
5596 * no need to set handler for them.
5598 if (!((G.non_DFL_mask >> sig) & 1)) {
5599 handler = signal(sig, sigexit);
5600 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5601 signal(sig, handler);
5604 /* Set handlers to restore tty pgrp and exit */
5605 static void set_fatal_handlers(void)
5607 /* We _must_ restore tty pgrp on fatal signals */
5609 maybe_set_to_sigexit(SIGILL );
5610 maybe_set_to_sigexit(SIGFPE );
5611 maybe_set_to_sigexit(SIGBUS );
5612 maybe_set_to_sigexit(SIGSEGV);
5613 maybe_set_to_sigexit(SIGTRAP);
5614 } /* else: hush is perfect. what SEGV? */
5615 maybe_set_to_sigexit(SIGABRT);
5616 /* bash 3.2 seems to handle these just like 'fatal' ones */
5617 maybe_set_to_sigexit(SIGPIPE);
5618 maybe_set_to_sigexit(SIGALRM);
5619 //TODO: disable and move down when proper SIGHUP handling is added
5620 maybe_set_to_sigexit(SIGHUP );
5621 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5622 * if we aren't interactive... but in this case
5623 * we never want to restore pgrp on exit, and this fn is not called */
5624 /*maybe_set_to_sigexit(SIGTERM);*/
5625 /*maybe_set_to_sigexit(SIGINT );*/
5629 static int set_mode(const char cstate, const char mode)
5631 int state = (cstate == '-' ? 1 : 0);
5633 case 'n': G.fake_mode = state; break;
5634 case 'x': /*G.debug_mode = state;*/ break;
5635 default: return EXIT_FAILURE;
5637 return EXIT_SUCCESS;
5640 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5641 int hush_main(int argc, char **argv)
5643 static const struct variable const_shell_ver = {
5645 .varstr = (char*)hush_version_str,
5646 .max_len = 1, /* 0 can provoke free(name) */
5650 int signal_mask_is_inited = 0;
5653 struct variable *cur_var;
5656 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5657 G.last_exitcode = EXIT_SUCCESS;
5659 G.argv0_for_re_execing = argv[0];
5661 /* Deal with HUSH_VERSION */
5662 G.shell_ver = const_shell_ver; /* copying struct here */
5663 G.top_var = &G.shell_ver;
5664 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5665 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5666 /* Initialize our shell local variables with the values
5667 * currently living in the environment */
5668 cur_var = G.top_var;
5671 char *value = strchr(*e, '=');
5672 if (value) { /* paranoia */
5673 cur_var->next = xzalloc(sizeof(*cur_var));
5674 cur_var = cur_var->next;
5675 cur_var->varstr = *e;
5676 cur_var->max_len = strlen(*e);
5677 cur_var->flg_export = 1;
5681 debug_printf_env("putenv '%s'\n", hush_version_str);
5682 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5683 #if ENABLE_FEATURE_EDITING
5684 G.line_input_state = new_line_input_t(FOR_SHELL);
5686 G.global_argc = argc;
5687 G.global_argv = argv;
5688 /* Initialize some more globals to non-zero values */
5690 #if ENABLE_HUSH_INTERACTIVE
5691 if (ENABLE_FEATURE_EDITING)
5692 cmdedit_set_initial_prompt();
5696 if (setjmp(die_jmp)) {
5697 /* xfunc has failed! die die die */
5698 /* no EXIT traps, this is an escape hatch! */
5700 hush_exit(xfunc_error_retval);
5703 /* Shell is non-interactive at first. We need to call
5704 * block_signals(0) if we are going to execute "sh <script>",
5705 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5706 * If we later decide that we are interactive, we run block_signals(0)
5707 * (or re-run block_signals(1) if we ran block_signals(0) before)
5708 * in order to intercept (more) signals.
5712 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5714 opt = getopt(argc, argv, "c:xins"
5724 G.root_pid = getpid();
5725 G.global_argv = argv + optind;
5726 if (!argv[optind]) {
5727 /* -c 'script' (no params): prevent empty $0 */
5728 *--G.global_argv = argv[0];
5730 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5731 G.global_argc = argc - optind;
5732 block_signals(0); /* 0: called 1st time */
5733 parse_and_run_string(optarg);
5736 /* Well, we cannot just declare interactiveness,
5737 * we have to have some stuff (ctty, etc) */
5738 /* G_interactive_fd++; */
5741 /* "-s" means "read from stdin", but this is how we always
5742 * operate, so simply do nothing here. */
5745 case '<': /* "big heredoc" support */
5746 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5749 G.root_pid = bb_strtou(optarg, &optarg, 16);
5751 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5753 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5754 # if ENABLE_HUSH_LOOPS
5756 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5761 set_local_var(xstrdup(optarg), 0, opt == 'R');
5766 if (!set_mode('-', opt))
5770 fprintf(stderr, "Usage: sh [FILE]...\n"
5771 " or: sh -c command [args]...\n\n");
5777 } /* option parsing loop */
5780 G.root_pid = getpid();
5782 /* If we are login shell... */
5783 if (argv[0] && argv[0][0] == '-') {
5785 /* XXX what should argv be while sourcing /etc/profile? */
5786 debug_printf("sourcing /etc/profile\n");
5787 input = fopen_for_read("/etc/profile");
5788 if (input != NULL) {
5789 close_on_exec_on(fileno(input));
5790 block_signals(0); /* 0: called 1st time */
5791 signal_mask_is_inited = 1;
5792 parse_and_run_file(input);
5795 /* bash: after sourcing /etc/profile,
5796 * tries to source (in the given order):
5797 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5798 * stopping of first found. --noprofile turns this off.
5799 * bash also sources ~/.bash_logout on exit.
5800 * If called as sh, skips .bash_XXX files.
5807 * "bash <script>" (which is never interactive (unless -i?))
5808 * sources $BASH_ENV here (without scanning $PATH).
5809 * If called as sh, does the same but with $ENV.
5811 debug_printf("running script '%s'\n", argv[optind]);
5812 G.global_argv = argv + optind;
5813 G.global_argc = argc - optind;
5814 input = xfopen_for_read(argv[optind]);
5815 close_on_exec_on(fileno(input));
5816 if (!signal_mask_is_inited)
5817 block_signals(0); /* 0: called 1st time */
5818 parse_and_run_file(input);
5819 #if ENABLE_FEATURE_CLEAN_UP
5825 /* Up to here, shell was non-interactive. Now it may become one.
5826 * NB: don't forget to (re)run block_signals(0/1) as needed.
5829 /* A shell is interactive if the '-i' flag was given, or if all of
5830 * the following conditions are met:
5832 * no arguments remaining or the -s flag given
5833 * standard input is a terminal
5834 * standard output is a terminal
5835 * Refer to Posix.2, the description of the 'sh' utility.
5838 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5839 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5840 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5841 //TODO: "interactive" and "have job control" are two different things.
5842 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5843 //should stay on! Currently, we mix these into one.
5844 if (G.saved_tty_pgrp >= 0) {
5845 /* try to dup stdin to high fd#, >= 255 */
5846 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5847 if (G_interactive_fd < 0) {
5848 /* try to dup to any fd */
5849 G_interactive_fd = dup(STDIN_FILENO);
5850 if (G_interactive_fd < 0)
5852 G_interactive_fd = 0;
5854 // TODO: track & disallow any attempts of user
5855 // to (inadvertently) close/redirect it
5858 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5859 if (G_interactive_fd) {
5862 /* We are indeed interactive shell, and we will perform
5863 * job control. Setting up for that. */
5865 close_on_exec_on(G_interactive_fd);
5866 /* If we were run as 'hush &', sleep until we are
5867 * in the foreground (tty pgrp == our pgrp).
5868 * If we get started under a job aware app (like bash),
5869 * make sure we are now in charge so we don't fight over
5870 * who gets the foreground */
5872 shell_pgrp = getpgrp();
5873 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5874 if (G.saved_tty_pgrp == shell_pgrp)
5876 /* send TTIN to ourself (should stop us) */
5877 kill(- shell_pgrp, SIGTTIN);
5879 /* Block some signals */
5880 block_signals(signal_mask_is_inited);
5881 /* Set other signals to restore saved_tty_pgrp */
5882 set_fatal_handlers();
5883 /* Put ourselves in our own process group */
5884 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5885 /* Grab control of the terminal */
5886 tcsetpgrp(G_interactive_fd, getpid());
5887 /* -1 is special - makes xfuncs longjmp, not exit
5888 * (we reset die_sleep = 0 whereever we [v]fork) */
5889 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5890 } else if (!signal_mask_is_inited) {
5891 block_signals(0); /* 0: called 1st time */
5892 } /* else: block_signals(0) was done before */
5893 #elif ENABLE_HUSH_INTERACTIVE
5894 /* No job control compiled in, only prompt/line editing */
5895 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5896 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5897 if (G_interactive_fd < 0) {
5898 /* try to dup to any fd */
5899 G_interactive_fd = dup(STDIN_FILENO);
5900 if (G_interactive_fd < 0)
5902 G_interactive_fd = 0;
5905 if (G_interactive_fd) {
5906 close_on_exec_on(G_interactive_fd);
5907 block_signals(signal_mask_is_inited);
5908 } else if (!signal_mask_is_inited) {
5912 /* We have interactiveness code disabled */
5913 if (!signal_mask_is_inited) {
5918 * if interactive but not a login shell, sources ~/.bashrc
5919 * (--norc turns this off, --rcfile <file> overrides)
5922 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5923 printf("\n\n%s hush - the humble shell\n", bb_banner);
5924 printf("Enter 'help' for a list of built-in commands.\n\n");
5927 parse_and_run_file(stdin);
5930 #if ENABLE_FEATURE_CLEAN_UP
5931 if (G.cwd != bb_msg_unknown)
5933 cur_var = G.top_var->next;
5935 struct variable *tmp = cur_var;
5936 if (!cur_var->max_len)
5937 free(cur_var->varstr);
5938 cur_var = cur_var->next;
5942 hush_exit(G.last_exitcode);
5947 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5948 int lash_main(int argc, char **argv)
5950 //bb_error_msg("lash is deprecated, please use hush instead");
5951 return hush_main(argc, argv);
5959 static int builtin_trap(char **argv)
5966 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5970 /* No args: print all trapped. This isn't 100% correct as we
5971 * should be escaping the cmd so that it can be pasted back in
5973 for (i = 0; i < NSIG; ++i)
5975 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5976 return EXIT_SUCCESS;
5981 /* If first arg is decimal: reset all specified signals */
5982 sig = bb_strtou(*argv, NULL, 10);
5988 sig = get_signum(*argv++);
5989 if (sig < 0 || sig >= NSIG) {
5991 /* Mimic bash message exactly */
5992 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5997 G.traps[sig] = xstrdup(new_cmd);
5999 debug_printf("trap: setting SIG%s (%i) to '%s'",
6000 get_signame(sig), sig, G.traps[sig]);
6002 /* There is no signal for 0 (EXIT) */
6007 sigaddset(&G.blocked_set, sig);
6009 /* There was a trap handler, we are removing it
6010 * (if sig has non-DFL handling,
6011 * we don't need to do anything) */
6012 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6014 sigdelset(&G.blocked_set, sig);
6016 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6021 /* First arg is "-": reset all specified to default */
6022 /* First arg is "": ignore all specified */
6023 /* Everything else: execute first arg upon signal */
6025 bb_error_msg("trap: invalid arguments");
6026 return EXIT_FAILURE;
6028 if (NOT_LONE_DASH(*argv))
6034 static int builtin_true(char **argv UNUSED_PARAM)
6039 static int builtin_test(char **argv)
6046 return test_main(argc, argv - argc);
6049 static int builtin_echo(char **argv)
6056 return echo_main(argc, argv - argc);
6059 static int builtin_eval(char **argv)
6061 int rcode = EXIT_SUCCESS;
6064 char *str = expand_strvec_to_string(argv);
6066 * eval "echo Hi; done" ("done" is syntax error):
6067 * "echo Hi" will not execute too.
6069 parse_and_run_string(str);
6071 rcode = G.last_exitcode;
6076 static int builtin_cd(char **argv)
6078 const char *newdir = argv[1];
6079 if (newdir == NULL) {
6080 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6081 * bash says "bash: cd: HOME not set" and does nothing
6084 newdir = getenv("HOME") ? : "/";
6086 if (chdir(newdir)) {
6087 /* Mimic bash message exactly */
6088 bb_perror_msg("cd: %s", newdir);
6089 return EXIT_FAILURE;
6092 return EXIT_SUCCESS;
6095 static int builtin_exec(char **argv)
6097 if (*++argv == NULL)
6098 return EXIT_SUCCESS; /* bash does this */
6103 // FIXME: if exec fails, bash does NOT exit! We do...
6104 pseudo_exec_argv(&dummy, argv, 0, NULL);
6109 static int builtin_exit(char **argv)
6111 debug_printf_exec("%s()\n", __func__);
6112 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6113 //puts("exit"); /* bash does it */
6114 // TODO: warn if we have background jobs: "There are stopped jobs"
6115 // On second consecutive 'exit', exit anyway.
6116 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6118 /* note: EXIT trap is run by hush_exit */
6119 if (*++argv == NULL)
6120 hush_exit(G.last_exitcode);
6121 /* mimic bash: exit 123abc == exit 255 + error msg */
6122 xfunc_error_retval = 255;
6123 /* bash: exit -2 == exit 254, no error msg */
6124 hush_exit(xatoi(*argv) & 0xff);
6127 static int builtin_export(char **argv)
6129 if (*++argv == NULL) {
6136 /* ash emits: export VAR='VAL'
6137 * bash: declare -x VAR="VAL"
6138 * we follow ash example */
6139 const char *s = *e++;
6140 const char *p = strchr(s, '=');
6142 if (!p) /* wtf? take next variable */
6145 printf("export %.*s", (int)(p - s) + 1, s);
6149 p = strchrnul(s, '\'');
6151 printf("'%.*s'", (int)(p - s), s);
6156 /* s points to '; print ''...'''" */
6158 do putchar('\''); while (*++s == '\'');
6166 return EXIT_SUCCESS;
6173 value = strchr(name, '=');
6175 /* They are exporting something without a =VALUE */
6176 struct variable *var;
6178 var = get_local_var(name);
6180 var->flg_export = 1;
6181 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6182 putenv(var->varstr);
6184 /* bash does not return an error when trying to export
6185 * an undefined variable. Do likewise. */
6188 set_local_var(xstrdup(name), 1, 0);
6191 return EXIT_SUCCESS;
6195 /* built-in 'fg' and 'bg' handler */
6196 static int builtin_fg_bg(char **argv)
6201 if (!G_interactive_fd)
6202 return EXIT_FAILURE;
6203 /* If they gave us no args, assume they want the last backgrounded task */
6205 for (pi = G.job_list; pi; pi = pi->next) {
6206 if (pi->jobid == G.last_jobid) {
6210 bb_error_msg("%s: no current job", argv[0]);
6211 return EXIT_FAILURE;
6213 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6214 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6215 return EXIT_FAILURE;
6217 for (pi = G.job_list; pi; pi = pi->next) {
6218 if (pi->jobid == jobnum) {
6222 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6223 return EXIT_FAILURE;
6225 // TODO: bash prints a string representation
6226 // of job being foregrounded (like "sleep 1 | cat")
6227 if (argv[0][0] == 'f') {
6228 /* Put the job into the foreground. */
6229 tcsetpgrp(G_interactive_fd, pi->pgrp);
6232 /* Restart the processes in the job */
6233 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6234 for (i = 0; i < pi->num_cmds; i++) {
6235 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6236 pi->cmds[i].is_stopped = 0;
6238 pi->stopped_cmds = 0;
6240 i = kill(- pi->pgrp, SIGCONT);
6242 if (errno == ESRCH) {
6243 delete_finished_bg_job(pi);
6244 return EXIT_SUCCESS;
6246 bb_perror_msg("kill (SIGCONT)");
6249 if (argv[0][0] == 'f') {
6251 return checkjobs_and_fg_shell(pi);
6253 return EXIT_SUCCESS;
6257 #if ENABLE_HUSH_HELP
6258 static int builtin_help(char **argv UNUSED_PARAM)
6260 const struct built_in_command *x;
6263 "Built-in commands:\n"
6264 "------------------\n");
6265 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6266 printf("%s\t%s\n", x->cmd, x->descr);
6269 return EXIT_SUCCESS;
6274 static int builtin_jobs(char **argv UNUSED_PARAM)
6277 const char *status_string;
6279 for (job = G.job_list; job; job = job->next) {
6280 if (job->alive_cmds == job->stopped_cmds)
6281 status_string = "Stopped";
6283 status_string = "Running";
6285 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6287 return EXIT_SUCCESS;
6292 static int builtin_memleak(char **argv UNUSED_PARAM)
6297 /* Crude attempt to find where "free memory" starts,
6298 * sans fragmentation. */
6300 l = (unsigned long)p;
6303 if (l < (unsigned long)p) l = (unsigned long)p;
6306 if (!G.memleak_value)
6307 G.memleak_value = l;
6309 l -= G.memleak_value;
6316 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6321 static int builtin_pwd(char **argv UNUSED_PARAM)
6324 return EXIT_SUCCESS;
6327 static int builtin_read(char **argv)
6330 const char *name = "REPLY";
6334 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6335 * and _after_ that_ it will complain */
6336 if (!is_well_formed_var_name(name, '\0')) {
6337 /* Mimic bash message */
6338 bb_error_msg("read: '%s': not a valid identifier", name);
6343 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6345 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6346 return set_local_var(string, 0, 0);
6349 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6350 * built-in 'set' handler
6352 * set [-abCefhmnuvx] [-o option] [argument...]
6353 * set [+abCefhmnuvx] [+o option] [argument...]
6354 * set -- [argument...]
6357 * Implementations shall support the options in both their hyphen and
6358 * plus-sign forms. These options can also be specified as options to sh.
6360 * Write out all variables and their values: set
6361 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6362 * Turn on the -x and -v options: set -xv
6363 * Unset all positional parameters: set --
6364 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6365 * Set the positional parameters to the expansion of x, even if x expands
6366 * with a leading '-' or '+': set -- $x
6368 * So far, we only support "set -- [argument...]" and some of the short names.
6370 static int builtin_set(char **argv)
6373 char **pp, **g_argv;
6374 char *arg = *++argv;
6378 for (e = G.top_var; e; e = e->next)
6380 return EXIT_SUCCESS;
6384 if (!strcmp(arg, "--")) {
6389 if (arg[0] == '+' || arg[0] == '-') {
6390 for (n = 1; arg[n]; ++n)
6391 if (set_mode(arg[0], arg[n]))
6397 } while ((arg = *++argv) != NULL);
6398 /* Now argv[0] is 1st argument */
6400 /* Only reset global_argv if we didn't process anything */
6402 return EXIT_SUCCESS;
6405 /* NB: G.global_argv[0] ($0) is never freed/changed */
6406 g_argv = G.global_argv;
6407 if (G.global_args_malloced) {
6413 G.global_args_malloced = 1;
6414 pp = xzalloc(sizeof(pp[0]) * 2);
6415 pp[0] = g_argv[0]; /* retain $0 */
6418 /* This realloc's G.global_argv */
6419 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6426 return EXIT_SUCCESS;
6428 /* Nothing known, so abort */
6430 bb_error_msg("set: %s: invalid option", arg);
6431 return EXIT_FAILURE;
6434 static int builtin_shift(char **argv)
6440 if (n >= 0 && n < G.global_argc) {
6441 if (G.global_args_malloced) {
6444 free(G.global_argv[m++]);
6447 memmove(&G.global_argv[1], &G.global_argv[n+1],
6448 G.global_argc * sizeof(G.global_argv[0]));
6449 return EXIT_SUCCESS;
6451 return EXIT_FAILURE;
6454 static int builtin_source(char **argv)
6458 if (*++argv == NULL)
6459 return EXIT_FAILURE;
6461 /* XXX search through $PATH is missing */
6462 input = fopen_or_warn(*argv, "r");
6464 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6465 return EXIT_FAILURE;
6467 close_on_exec_on(fileno(input));
6469 /* Now run the file */
6471 /* XXX argv and argc are broken; need to save old G.global_argv
6472 * (pointer only is OK!) on this stack frame,
6473 * set G.global_argv=argv+1, recurse, and restore. */
6474 parse_and_run_file(input);
6476 return G.last_exitcode;
6479 static int builtin_umask(char **argv)
6482 const char *arg = argv[1];
6484 //TODO: umask may take chmod-like symbolic masks
6485 new_umask = bb_strtou(arg, NULL, 8);
6487 //Message? bash examples:
6488 //bash: umask: 'q': invalid symbolic mode operator
6489 //bash: umask: 999: octal number out of range
6490 return EXIT_FAILURE;
6493 new_umask = umask(0);
6494 printf("%.3o\n", (unsigned) new_umask);
6495 /* fall through and restore new_umask which we set to 0 */
6498 return EXIT_SUCCESS;
6501 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6502 static int builtin_unset(char **argv)
6508 return EXIT_SUCCESS;
6511 if (argv[0][0] == '-') {
6512 switch (argv[0][1]) {
6518 bb_error_msg("unset: %s: invalid option", *argv);
6519 return EXIT_FAILURE;
6521 //TODO: disallow "unset -vf ..." too
6528 if (unset_local_var(*argv)) {
6529 /* unset <nonexistent_var> doesn't fail.
6530 * Error is when one tries to unset RO var.
6531 * Message was printed by unset_local_var. */
6535 //#if ENABLE_HUSH_FUNCTIONS
6537 // unset_local_func(*argv);
6545 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6546 static int builtin_wait(char **argv)
6548 int ret = EXIT_SUCCESS;
6551 if (*++argv == NULL) {
6552 /* Don't care about wait results */
6553 /* Note 1: must wait until there are no more children */
6554 /* Note 2: must be interruptible */
6556 * $ sleep 3 & sleep 6 & wait
6561 * $ sleep 3 & sleep 6 & wait
6565 * ^C <-- after ~4 sec from keyboard
6568 sigaddset(&G.blocked_set, SIGCHLD);
6569 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6572 if (errno == ECHILD)
6574 /* Wait for SIGCHLD or any other signal of interest */
6575 /* sigtimedwait with infinite timeout: */
6576 sig = sigwaitinfo(&G.blocked_set, NULL);
6578 sig = check_and_run_traps(sig);
6579 if (sig && sig != SIGCHLD) { /* see note 2 */
6585 sigdelset(&G.blocked_set, SIGCHLD);
6586 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6590 /* This is probably buggy wrt interruptible-ness */
6592 pid_t pid = bb_strtou(*argv, NULL, 10);
6594 /* mimic bash message */
6595 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6596 return EXIT_FAILURE;
6598 if (waitpid(pid, &status, 0) == pid) {
6599 if (WIFSIGNALED(status))
6600 ret = 128 + WTERMSIG(status);
6601 else if (WIFEXITED(status))
6602 ret = WEXITSTATUS(status);
6606 bb_perror_msg("wait %s", *argv);
6615 #if ENABLE_HUSH_LOOPS
6616 static int builtin_break(char **argv)
6618 if (G.depth_of_loop == 0) {
6619 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6620 return EXIT_SUCCESS; /* bash compat */
6622 G.flag_break_continue++; /* BC_BREAK = 1 */
6623 G.depth_break_continue = 1;
6625 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6626 if (errno || !G.depth_break_continue || argv[2]) {
6627 bb_error_msg("%s: bad arguments", argv[0]);
6628 G.flag_break_continue = BC_BREAK;
6629 G.depth_break_continue = UINT_MAX;
6632 if (G.depth_of_loop < G.depth_break_continue)
6633 G.depth_break_continue = G.depth_of_loop;
6634 return EXIT_SUCCESS;
6637 static int builtin_continue(char **argv)
6639 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6640 return builtin_break(argv);