1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
46 * Bash stuff (maybe optionally enable?):
47 * &> and >& redirection of stdout+stderr
49 * reserved words: [[ ]] function select
50 * substrings ${var:1:5}
53 * grep for "TODO" and fix (some of them are easy)
54 * change { and } from special chars to reserved words
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * ^Z handling (and explain it in comments for mere humans)
61 * separate job control from interactiveness
62 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
67 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 /* #include <dmalloc.h> */
76 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
80 /* Debug build knobs */
81 #define LEAK_HUNTING 0
82 #define BUILD_AS_NOMMU 0
83 /* Enable/disable sanity checks. Ok to enable in production,
84 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
85 * Keeping 1 for now even in released versions.
89 #define ENABLE_HUSH_FUNCTIONS 0
97 # define USE_FOR_NOMMU(...) __VA_ARGS__
98 # define USE_FOR_MMU(...)
101 #if defined SINGLE_APPLET_MAIN
102 /* STANDALONE does not make sense, and won't compile */
103 #undef CONFIG_FEATURE_SH_STANDALONE
104 #undef ENABLE_FEATURE_SH_STANDALONE
105 #undef USE_FEATURE_SH_STANDALONE
106 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #define ENABLE_FEATURE_SH_STANDALONE 0
108 #define USE_FEATURE_SH_STANDALONE(...)
109 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
112 #if !ENABLE_HUSH_INTERACTIVE
113 #undef ENABLE_FEATURE_EDITING
114 #define ENABLE_FEATURE_EDITING 0
115 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
116 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
119 /* Do we support ANY keywords? */
120 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
121 #define HAS_KEYWORDS 1
122 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
123 #define IF_HAS_NO_KEYWORDS(...)
125 #define HAS_KEYWORDS 0
126 #define IF_HAS_KEYWORDS(...)
127 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
130 /* If you comment out one of these below, it will be #defined later
131 * to perform debug printfs to stderr: */
132 #define debug_printf(...) do {} while (0)
133 /* Finer-grained debug switches */
134 #define debug_printf_parse(...) do {} while (0)
135 #define debug_print_tree(a, b) do {} while (0)
136 #define debug_printf_exec(...) do {} while (0)
137 #define debug_printf_env(...) do {} while (0)
138 #define debug_printf_jobs(...) do {} while (0)
139 #define debug_printf_expand(...) do {} while (0)
140 #define debug_printf_glob(...) do {} while (0)
141 #define debug_printf_list(...) do {} while (0)
142 #define debug_printf_subst(...) do {} while (0)
143 #define debug_printf_clean(...) do {} while (0)
146 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
149 #ifndef debug_printf_parse
150 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_exec
154 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_env
158 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
161 #ifndef debug_printf_jobs
162 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
168 #ifndef debug_printf_expand
169 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
170 #define DEBUG_EXPAND 1
172 #define DEBUG_EXPAND 0
175 #ifndef debug_printf_glob
176 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
182 #ifndef debug_printf_list
183 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_subst
187 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
190 #ifndef debug_printf_clean
191 /* broken, of course, but OK for testing */
192 static const char *indenter(int i)
194 static const char blanks[] ALIGN1 =
196 return &blanks[sizeof(blanks) - i - 1];
198 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
199 #define DEBUG_CLEAN 1
201 #define DEBUG_CLEAN 0
205 static void debug_print_strings(const char *prefix, char **vv)
207 fprintf(stderr, "%s:\n", prefix);
209 fprintf(stderr, " '%s'\n", *vv++);
212 #define debug_print_strings(prefix, vv) ((void)0)
215 #define ERR_PTR ((void*)(long)1)
217 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
219 #define SPECIAL_VAR_SYMBOL 3
221 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
223 /* This supports saving pointers malloced in vfork child,
224 * to be freed in the parent. One pointer is saved in
225 * G.argv_from_re_execing global var instead. TODO: unify.
228 typedef struct nommu_save_t {
235 /* The descrip member of this structure is only used to make
236 * debugging output pretty */
237 static const struct {
239 signed char default_fd;
243 { O_RDONLY, 0, "<" },
244 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
245 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
246 { O_RDONLY, 0, "<<" },
247 { O_CREAT|O_RDWR, 1, "<>" },
248 /* Should not be needed. Bogus default_fd helps in debugging */
249 /* { O_RDONLY, 77, "<<" }, */
252 typedef enum reserved_style {
261 #if ENABLE_HUSH_LOOPS
268 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
273 /* two pseudo-keywords support contrived "case" syntax: */
274 RES_MATCH , /* "word)" */
275 RES_CASEI , /* "this command is inside CASE" */
282 typedef struct o_string {
284 int length; /* position where data is appended */
286 /* Protect newly added chars against globbing
287 * (by prepending \ to *, ?, [, \) */
290 /* At least some part of the string was inside '' or "",
291 * possibly empty one: word"", wo''rd etc. */
293 smallint has_empty_slot;
294 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
297 MAYBE_ASSIGNMENT = 0,
298 DEFINITELY_ASSIGNMENT = 1,
300 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
302 /* Used for initialization: o_string foo = NULL_O_STRING; */
303 #define NULL_O_STRING { NULL }
305 /* I can almost use ordinary FILE*. Is open_memstream() universally
306 * available? Where is it documented? */
307 typedef struct in_str {
309 /* eof_flag=1: last char in ->p is really an EOF */
310 char eof_flag; /* meaningless if ->p == NULL */
312 #if ENABLE_HUSH_INTERACTIVE
314 smallint promptmode; /* 0: PS1, 1: PS2 */
317 int (*get) (struct in_str *);
318 int (*peek) (struct in_str *);
320 #define i_getch(input) ((input)->get(input))
321 #define i_peek(input) ((input)->peek(input))
323 struct redir_struct {
324 struct redir_struct *next;
325 char *rd_filename; /* filename */
326 int rd_fd; /* fd to redirect */
327 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
329 smallint rd_type; /* (enum redir_type) */
330 /* note: for heredocs, rd_filename contains heredoc delimiter,
331 * and subsequently heredoc itself; and rd_dup is a bitmask:
332 * 1: do we need to trim leading tabs?
333 * 2: is heredoc quoted (<<'dleim' syntax) ?
336 typedef enum redir_type {
337 REDIRECT_INVALID = 0,
339 REDIRECT_OVERWRITE = 2,
341 REDIRECT_HEREDOC = 4,
343 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
346 REDIRFD_SYNTAX_ERR = -2,
347 REDIRFD_TO_FILE = -1,
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 job */
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 /* "Globals" within this file */
457 /* Sorted roughly by size (smaller offsets == smaller code) */
459 #if ENABLE_HUSH_INTERACTIVE
460 /* 'interactive_fd' is a fd# open to ctty, if we have one
461 * _AND_ if we decided to act interactively */
465 #define G_interactive_fd (G.interactive_fd)
467 #define G_interactive_fd 0
469 #if ENABLE_FEATURE_EDITING
470 line_input_t *line_input_state;
476 pid_t saved_tty_pgrp;
478 struct pipe *job_list;
479 struct pipe *toplevel_list;
480 //// smallint ctrl_z_flag;
482 smallint flag_SIGINT;
483 #if ENABLE_HUSH_LOOPS
484 smallint flag_break_continue;
487 smallint exiting; /* used to prevent EXIT trap recursion */
488 /* These four support $?, $#, and $1 */
489 smalluint last_exitcode;
490 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
491 smalluint global_args_malloced;
492 /* how many non-NULL argv's we have. NB: $# + 1 */
496 char *argv0_for_re_execing;
497 char **argv_from_re_execing;
499 #if ENABLE_HUSH_LOOPS
500 unsigned depth_break_continue;
501 unsigned depth_of_loop;
505 struct variable *top_var; /* = &G.shell_ver (set in main()) */
506 struct variable shell_ver;
507 /* Signal and trap handling */
508 // unsigned count_SIGCHLD;
509 // unsigned handled_SIGCHLD;
510 /* which signals have non-DFL handler (even with no traps set)? */
511 unsigned non_DFL_mask;
512 char **traps; /* char *traps[NSIG] */
513 sigset_t blocked_set;
514 sigset_t inherited_set;
516 unsigned long memleak_value;
518 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
519 #if ENABLE_FEATURE_SH_STANDALONE
520 struct nofork_save_area nofork_save;
523 sigjmp_buf toplevel_jb;
526 #define G (*ptr_to_globals)
527 /* Not #defining name to G.name - this quickly gets unwieldy
528 * (too many defines). Also, I actually prefer to see when a variable
529 * is global, thus "G." prefix is a useful hint */
530 #define INIT_G() do { \
531 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
535 /* Function prototypes for builtins */
536 static int builtin_cd(char **argv);
537 static int builtin_echo(char **argv);
538 static int builtin_eval(char **argv);
539 static int builtin_exec(char **argv);
540 static int builtin_exit(char **argv);
541 static int builtin_export(char **argv);
543 static int builtin_fg_bg(char **argv);
544 static int builtin_jobs(char **argv);
547 static int builtin_help(char **argv);
550 static int builtin_memleak(char **argv);
552 static int builtin_pwd(char **argv);
553 static int builtin_read(char **argv);
554 static int builtin_set(char **argv);
555 static int builtin_shift(char **argv);
556 static int builtin_source(char **argv);
557 static int builtin_test(char **argv);
558 static int builtin_trap(char **argv);
559 static int builtin_true(char **argv);
560 static int builtin_umask(char **argv);
561 static int builtin_unset(char **argv);
562 static int builtin_wait(char **argv);
563 #if ENABLE_HUSH_LOOPS
564 static int builtin_break(char **argv);
565 static int builtin_continue(char **argv);
568 /* Table of built-in functions. They can be forked or not, depending on
569 * context: within pipes, they fork. As simple commands, they do not.
570 * When used in non-forking context, they can change global variables
571 * in the parent shell process. If forked, of course they cannot.
572 * For example, 'unset foo | whatever' will parse and run, but foo will
573 * still be set at the end. */
574 struct built_in_command {
576 int (*function)(char **argv);
579 #define BLTIN(cmd, func, help) { cmd, func, help }
581 #define BLTIN(cmd, func, help) { cmd, func }
585 /* For now, echo and test are unconditionally enabled.
586 * Maybe make it configurable? */
587 static const struct built_in_command bltins[] = {
588 BLTIN("." , builtin_source , "Run commands in a file"),
589 BLTIN(":" , builtin_true , "No-op"),
590 BLTIN("[" , builtin_test , "Test condition"),
592 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
594 #if ENABLE_HUSH_LOOPS
595 BLTIN("break" , builtin_break , "Exit from a loop"),
597 BLTIN("cd" , builtin_cd , "Change directory"),
598 #if ENABLE_HUSH_LOOPS
599 BLTIN("continue", builtin_continue, "Start new loop iteration"),
601 BLTIN("echo" , builtin_echo , "Write to stdout"),
602 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
603 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
604 BLTIN("exit" , builtin_exit , "Exit"),
605 BLTIN("export" , builtin_export , "Set environment variable"),
607 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
610 BLTIN("help" , builtin_help , "List shell built-in commands"),
613 BLTIN("jobs" , builtin_jobs , "List active jobs"),
616 BLTIN("memleak" , builtin_memleak , "Debug tool"),
618 BLTIN("pwd" , builtin_pwd , "Print current directory"),
619 BLTIN("read" , builtin_read , "Input environment variable"),
620 // BLTIN("return" , builtin_return , "Return from a function"),
621 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
622 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
623 BLTIN("test" , builtin_test , "Test condition"),
624 BLTIN("trap" , builtin_trap , "Trap signals"),
625 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
626 BLTIN("umask" , builtin_umask , "Set file creation mask"),
627 BLTIN("unset" , builtin_unset , "Unset environment variable"),
628 BLTIN("wait" , builtin_wait , "Wait for process"),
632 /* Leak hunting. Use hush_leaktool.sh for post-processing.
635 static void *xxmalloc(int lineno, size_t size)
637 void *ptr = xmalloc((size + 0xff) & ~0xff);
638 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
641 static void *xxrealloc(int lineno, void *ptr, size_t size)
643 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
644 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
647 static char *xxstrdup(int lineno, const char *str)
649 char *ptr = xstrdup(str);
650 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
653 static void xxfree(void *ptr)
655 fdprintf(2, "free %p\n", ptr);
658 #define xmalloc(s) xxmalloc(__LINE__, s)
659 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
660 #define xstrdup(s) xxstrdup(__LINE__, s)
661 #define free(p) xxfree(p)
665 /* Syntax and runtime errors. They always abort scripts.
666 * In interactive use they usually discard unparsed and/or unexecuted commands
667 * and return to the prompt.
668 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
671 # define die_if_script(lineno, fmt...) die_if_script(fmt)
672 # define syntax_error(lineno, msg) syntax_error(msg)
673 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
674 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
675 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
678 static void die_if_script(unsigned lineno, const char *fmt, ...)
683 bb_error_msg("hush.c:%u", lineno);
686 bb_verror_msg(fmt, p, NULL);
688 if (!G_interactive_fd)
692 static void syntax_error(unsigned lineno, const char *msg)
695 die_if_script(lineno, "syntax error: %s", msg);
697 die_if_script(lineno, "syntax error", NULL);
700 static void syntax_error_at(unsigned lineno, const char *msg)
702 die_if_script(lineno, "syntax error at '%s'", msg);
705 static void syntax_error_unterm_ch(unsigned lineno, char ch)
710 die_if_script(lineno, "syntax error: unterminated %s", msg);
713 static void syntax_error_unterm_str(unsigned lineno, const char *s)
715 die_if_script(lineno, "syntax error: unterminated %s", s);
719 # undef die_if_script
721 # undef syntax_error_at
722 # undef syntax_error_unterm_ch
723 # undef syntax_error_unterm_str
725 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
726 # define syntax_error(msg) syntax_error(__LINE__, msg)
727 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
728 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
729 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
735 static int glob_needed(const char *s)
740 if (*s == '*' || *s == '[' || *s == '?')
747 static int is_well_formed_var_name(const char *s, char terminator)
749 if (!s || !(isalpha(*s) || *s == '_'))
752 while (isalnum(*s) || *s == '_')
754 return *s == terminator;
757 /* Replace each \x with x in place, return ptr past NUL. */
758 static char *unbackslash(char *src)
764 if ((*dst++ = *src++) == '\0')
770 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
791 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
792 v[count1 + count2] = NULL;
795 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
799 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
801 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
802 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
805 #define add_strings_to_strings(strings, add, need_to_dup) \
806 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
809 static char **add_string_to_strings(char **strings, char *add)
814 return add_strings_to_strings(strings, v, /*dup:*/ 0);
817 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
819 char **ptr = add_string_to_strings(strings, add);
820 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
823 #define add_string_to_strings(strings, add) \
824 xx_add_string_to_strings(__LINE__, strings, add)
827 static void putenv_all(char **strings)
832 debug_printf_env("putenv '%s'\n", *strings);
837 static char **putenv_all_and_save_old(char **strings)
847 eq = strchr(*strings, '=');
850 v = getenv(*strings);
853 /* v points to VAL in VAR=VAL, go back to VAR */
854 v -= (eq - *strings) + 1;
855 old = add_string_to_strings(old, v);
864 static void free_strings_and_unsetenv(char **strings, int unset)
874 debug_printf_env("unsetenv '%s'\n", *v);
882 static void free_strings(char **strings)
884 free_strings_and_unsetenv(strings, 0);
888 /* Basic theory of signal handling in shell
889 * ========================================
890 * This does not describe what hush does, rather, it is current understanding
891 * what it _should_ do. If it doesn't, it's a bug.
892 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
894 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
895 * is finished or backgrounded. It is the same in interactive and
896 * non-interactive shells, and is the same regardless of whether
897 * a user trap handler is installed or a shell special one is in effect.
898 * ^C or ^Z from keyboard seem to execute "at once" because it usually
899 * backgrounds (i.e. stops) or kills all members of currently running
902 * Wait builtin in interruptible by signals for which user trap is set
903 * or by SIGINT in interactive shell.
905 * Trap handlers will execute even within trap handlers. (right?)
907 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
909 * If job control is off, backgrounded commands ("cmd &")
910 * have SIGINT, SIGQUIT set to SIG_IGN.
912 * Commands run in command substitution ("`cmd`")
913 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
915 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
916 * by the shell from its parent.
918 * Siganls which differ from SIG_DFL action
919 * (note: child (i.e., [v]forked) shell is not an interactive shell):
922 * SIGTERM (interactive): ignore
923 * SIGHUP (interactive):
924 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
925 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
926 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
927 * that all pipe members are stopped) (right?)
928 * SIGINT (interactive): wait for last pipe, ignore the rest
929 * of the command line, show prompt. NB: ^C does not send SIGINT
930 * to interactive shell while shell is waiting for a pipe,
931 * since shell is bg'ed (is not in foreground process group).
932 * (check/expand this)
933 * Example 1: this waits 5 sec, but does not execute ls:
934 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
935 * Example 2: this does not wait and does not execute ls:
936 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
937 * Example 3: this does not wait 5 sec, but executes ls:
938 * "sleep 5; ls -l" + press ^C
940 * (What happens to signals which are IGN on shell start?)
941 * (What happens with signal mask on shell start?)
943 * Implementation in hush
944 * ======================
945 * We use in-kernel pending signal mask to determine which signals were sent.
946 * We block all signals which we don't want to take action immediately,
947 * i.e. we block all signals which need to have special handling as described
948 * above, and all signals which have traps set.
949 * After each pipe execution, we extract any pending signals via sigtimedwait()
952 * unsigned non_DFL_mask: a mask of such "special" signals
953 * sigset_t blocked_set: current blocked signal set
956 * clear bit in blocked_set unless it is also in non_DFL_mask
957 * "trap 'cmd' SIGxxx":
958 * set bit in blocked_set (even if 'cmd' is '')
959 * after [v]fork, if we plan to be a shell:
960 * nothing for {} child shell (say, "true | { true; true; } | true")
961 * unset all traps if () shell.
962 * after [v]fork, if we plan to exec:
963 * POSIX says pending signal mask is cleared in child - no need to clear it.
964 * Restore blocked signal set to one inherited by shell just prior to exec.
966 * Note: as a result, we do not use signal handlers much. The only uses
967 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
968 * and to restore tty pgrp on signal-induced exit.
971 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
973 // G.count_SIGCHLD++;
976 static int check_and_run_traps(int sig)
978 static const struct timespec zero_timespec = { 0, 0 };
979 smalluint save_rcode;
985 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
990 if (G.traps && G.traps[sig]) {
991 if (G.traps[sig][0]) {
992 /* We have user-defined handler */
993 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
994 save_rcode = G.last_exitcode;
997 G.last_exitcode = save_rcode;
998 } /* else: "" trap, ignoring signal */
1001 /* not a trap: special action */
1004 // G.count_SIGCHLD++;
1013 default: /* ignored: */
1014 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1023 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1024 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1025 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1026 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1028 /* Restores tty foreground process group, and exits.
1029 * May be called as signal handler for fatal signal
1030 * (will faithfully resend signal to itself, producing correct exit state)
1031 * or called directly with -EXITCODE.
1032 * We also call it if xfunc is exiting. */
1033 static void sigexit(int sig) NORETURN;
1034 static void sigexit(int sig)
1036 /* Disable all signals: job control, SIGPIPE, etc. */
1037 sigprocmask_allsigs(SIG_BLOCK);
1039 /* Careful: we can end up here after [v]fork. Do not restore
1040 * tty pgrp then, only top-level shell process does that */
1041 if (G_interactive_fd && getpid() == G.root_pid)
1042 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1044 /* Not a signal, just exit */
1048 kill_myself_with_sig(sig); /* does not return */
1052 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1053 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1057 /* Restores tty foreground process group, and exits. */
1058 static void hush_exit(int exitcode) NORETURN;
1059 static void hush_exit(int exitcode)
1061 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1062 /* Prevent recursion:
1063 * trap "echo Hi; exit" EXIT; exit
1065 char *argv[] = { NULL, G.traps[0], NULL };
1073 fflush(NULL); /* flush all streams */
1074 sigexit(- (exitcode & 0xff));
1081 static const char *set_cwd(void)
1083 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1084 * we must not try to free(bb_msg_unknown) */
1085 if (G.cwd == bb_msg_unknown)
1087 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1089 G.cwd = bb_msg_unknown;
1094 /* Get/check local shell variables */
1095 static struct variable *get_local_var(const char *name)
1097 struct variable *cur;
1103 for (cur = G.top_var; cur; cur = cur->next) {
1104 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1110 static const char *get_local_var_value(const char *src)
1112 struct variable *var = get_local_var(src);
1114 return strchr(var->varstr, '=') + 1;
1118 /* str holds "NAME=VAL" and is expected to be malloced.
1119 * We take ownership of it.
1123 * -1: if NAME is set, leave export status alone
1124 * if NAME is not set, do not export
1125 * flg_read_only is set only when we handle -R var=val
1128 #define set_local_var(str, flg_export, flg_read_only) \
1129 set_local_var(str, flg_export)
1131 static int set_local_var(char *str, int flg_export, int flg_read_only)
1133 struct variable *cur;
1137 value = strchr(str, '=');
1138 if (!value) { /* not expected to ever happen? */
1143 name_len = value - str + 1; /* including '=' */
1144 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1146 if (strncmp(cur->varstr, str, name_len) != 0) {
1148 /* Bail out. Note that now cur points
1149 * to last var in linked list */
1155 /* We found an existing var with this name */
1157 if (cur->flg_read_only) {
1161 bb_error_msg("%s: readonly variable", str);
1165 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1166 unsetenv(str); /* just in case */
1168 if (strcmp(cur->varstr, str) == 0) {
1173 if (cur->max_len >= strlen(str)) {
1174 /* This one is from startup env, reuse space */
1175 strcpy(cur->varstr, str);
1178 /* max_len == 0 signifies "malloced" var, which we can
1179 * (and has to) free */
1183 goto set_str_and_exp;
1186 /* Not found - create next variable struct */
1187 cur->next = xzalloc(sizeof(*cur));
1193 cur->flg_read_only = flg_read_only;
1196 if (flg_export == 1)
1197 cur->flg_export = 1;
1198 if (cur->flg_export) {
1199 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1200 return putenv(cur->varstr);
1205 static int unset_local_var(const char *name)
1207 struct variable *cur;
1208 struct variable *prev = prev; /* for gcc */
1212 return EXIT_SUCCESS;
1213 name_len = strlen(name);
1216 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1217 if (cur->flg_read_only) {
1218 bb_error_msg("%s: readonly variable", name);
1219 return EXIT_FAILURE;
1221 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1222 * is ro, and we cannot reach this code on the 1st pass */
1223 prev->next = cur->next;
1224 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1225 bb_unsetenv(cur->varstr);
1229 return EXIT_SUCCESS;
1234 return EXIT_SUCCESS;
1237 #if ENABLE_SH_MATH_SUPPORT
1238 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1239 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1240 static char *endofname(const char *name)
1248 if (!is_in_name(*p))
1254 static void arith_set_local_var(const char *name, const char *val, int flags)
1256 /* arith code doesnt malloc space, so do it for it */
1257 char *var = xasprintf("%s=%s", name, val);
1258 set_local_var(var, flags, 0);
1266 static int static_get(struct in_str *i)
1275 static int static_peek(struct in_str *i)
1280 #if ENABLE_HUSH_INTERACTIVE
1282 static void cmdedit_set_initial_prompt(void)
1284 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1285 G.PS1 = getenv("PS1");
1292 static const char* setup_prompt_string(int promptmode)
1294 const char *prompt_str;
1295 debug_printf("setup_prompt_string %d ", promptmode);
1296 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1297 /* Set up the prompt */
1298 if (promptmode == 0) { /* PS1 */
1300 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1305 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1306 debug_printf("result '%s'\n", prompt_str);
1310 static void get_user_input(struct in_str *i)
1313 const char *prompt_str;
1315 prompt_str = setup_prompt_string(i->promptmode);
1316 #if ENABLE_FEATURE_EDITING
1317 /* Enable command line editing only while a command line
1318 * is actually being read */
1321 /* buglet: SIGINT will not make new prompt to appear _at once_,
1322 * only after <Enter>. (^C will work) */
1323 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1324 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1325 check_and_run_traps(0);
1326 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1327 i->eof_flag = (r < 0);
1328 if (i->eof_flag) { /* EOF/error detected */
1329 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1330 G.user_input_buf[1] = '\0';
1335 fputs(prompt_str, stdout);
1337 G.user_input_buf[0] = r = fgetc(i->file);
1338 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1339 //do we need check_and_run_traps(0)? (maybe only if stdin)
1340 } while (G.flag_SIGINT);
1341 i->eof_flag = (r == EOF);
1343 i->p = G.user_input_buf;
1346 #endif /* INTERACTIVE */
1348 /* This is the magic location that prints prompts
1349 * and gets data back from the user */
1350 static int file_get(struct in_str *i)
1354 /* If there is data waiting, eat it up */
1355 if (i->p && *i->p) {
1356 #if ENABLE_HUSH_INTERACTIVE
1360 if (i->eof_flag && !*i->p)
1362 /* note: ch is never NUL */
1364 /* need to double check i->file because we might be doing something
1365 * more complicated by now, like sourcing or substituting. */
1366 #if ENABLE_HUSH_INTERACTIVE
1367 if (G_interactive_fd && i->promptme && i->file == stdin) {
1370 } while (!*i->p); /* need non-empty line */
1371 i->promptmode = 1; /* PS2 */
1376 do ch = fgetc(i->file); while (ch == '\0');
1378 debug_printf("file_get: got '%c' %d\n", ch, ch);
1379 #if ENABLE_HUSH_INTERACTIVE
1386 /* All callers guarantee this routine will never
1387 * be used right after a newline, so prompting is not needed.
1389 static int file_peek(struct in_str *i)
1392 if (i->p && *i->p) {
1393 if (i->eof_flag && !i->p[1])
1396 /* note: ch is never NUL */
1398 do ch = fgetc(i->file); while (ch == '\0');
1399 i->eof_flag = (ch == EOF);
1400 i->peek_buf[0] = ch;
1401 i->peek_buf[1] = '\0';
1403 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1407 static void setup_file_in_str(struct in_str *i, FILE *f)
1409 i->peek = file_peek;
1411 #if ENABLE_HUSH_INTERACTIVE
1413 i->promptmode = 0; /* PS1 */
1419 static void setup_string_in_str(struct in_str *i, const char *s)
1421 i->peek = static_peek;
1422 i->get = static_get;
1423 #if ENABLE_HUSH_INTERACTIVE
1425 i->promptmode = 0; /* PS1 */
1435 #define B_CHUNK (32 * sizeof(char*))
1437 static void o_reset(o_string *o)
1445 static void o_free(o_string *o)
1448 memset(o, 0, sizeof(*o));
1451 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1456 static void o_grow_by(o_string *o, int len)
1458 if (o->length + len > o->maxlen) {
1459 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1460 o->data = xrealloc(o->data, 1 + o->maxlen);
1464 static void o_addchr(o_string *o, int ch)
1466 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1468 o->data[o->length] = ch;
1470 o->data[o->length] = '\0';
1473 static void o_addblock(o_string *o, const char *str, int len)
1476 memcpy(&o->data[o->length], str, len);
1478 o->data[o->length] = '\0';
1482 static void o_addstr(o_string *o, const char *str)
1484 o_addblock(o, str, strlen(str));
1486 static void nommu_addchr(o_string *o, int ch)
1492 #define nommu_addchr(o, str) ((void)0)
1495 static void o_addstr_with_NUL(o_string *o, const char *str)
1497 o_addblock(o, str, strlen(str) + 1);
1500 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1505 && (*str != '*' && *str != '?' && *str != '[')
1513 /* My analysis of quoting semantics tells me that state information
1514 * is associated with a destination, not a source.
1516 static void o_addqchr(o_string *o, int ch)
1519 char *found = strchr("*?[\\", ch);
1524 o->data[o->length] = '\\';
1527 o->data[o->length] = ch;
1529 o->data[o->length] = '\0';
1532 static void o_addQchr(o_string *o, int ch)
1535 if (o->o_escape && strchr("*?[\\", ch)) {
1537 o->data[o->length] = '\\';
1541 o->data[o->length] = ch;
1543 o->data[o->length] = '\0';
1546 static void o_addQstr(o_string *o, const char *str, int len)
1549 o_addblock(o, str, len);
1555 int ordinary_cnt = strcspn(str, "*?[\\");
1556 if (ordinary_cnt > len) /* paranoia */
1558 o_addblock(o, str, ordinary_cnt);
1559 if (ordinary_cnt == len)
1561 str += ordinary_cnt;
1562 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1566 if (ch) { /* it is necessarily one of "*?[\\" */
1568 o->data[o->length] = '\\';
1572 o->data[o->length] = ch;
1574 o->data[o->length] = '\0';
1578 /* A special kind of o_string for $VAR and `cmd` expansion.
1579 * It contains char* list[] at the beginning, which is grown in 16 element
1580 * increments. Actual string data starts at the next multiple of 16 * (char*).
1581 * list[i] contains an INDEX (int!) into this string data.
1582 * It means that if list[] needs to grow, data needs to be moved higher up
1583 * but list[i]'s need not be modified.
1584 * NB: remembering how many list[i]'s you have there is crucial.
1585 * o_finalize_list() operation post-processes this structure - calculates
1586 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1588 #if DEBUG_EXPAND || DEBUG_GLOB
1589 static void debug_print_list(const char *prefix, o_string *o, int n)
1591 char **list = (char**)o->data;
1592 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1594 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1595 prefix, list, n, string_start, o->length, o->maxlen);
1597 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1598 o->data + (int)list[i] + string_start,
1599 o->data + (int)list[i] + string_start);
1603 const char *p = o->data + (int)list[n - 1] + string_start;
1604 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1608 #define debug_print_list(prefix, o, n) ((void)0)
1611 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1612 * in list[n] so that it points past last stored byte so far.
1613 * It returns n+1. */
1614 static int o_save_ptr_helper(o_string *o, int n)
1616 char **list = (char**)o->data;
1620 if (!o->has_empty_slot) {
1621 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1622 string_len = o->length - string_start;
1623 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1624 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1625 /* list[n] points to string_start, make space for 16 more pointers */
1626 o->maxlen += 0x10 * sizeof(list[0]);
1627 o->data = xrealloc(o->data, o->maxlen + 1);
1628 list = (char**)o->data;
1629 memmove(list + n + 0x10, list + n, string_len);
1630 o->length += 0x10 * sizeof(list[0]);
1632 debug_printf_list("list[%d]=%d string_start=%d\n",
1633 n, string_len, string_start);
1636 /* We have empty slot at list[n], reuse without growth */
1637 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1638 string_len = o->length - string_start;
1639 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1640 n, string_len, string_start);
1641 o->has_empty_slot = 0;
1643 list[n] = (char*)(ptrdiff_t)string_len;
1647 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1648 static int o_get_last_ptr(o_string *o, int n)
1650 char **list = (char**)o->data;
1651 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1653 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1656 /* o_glob performs globbing on last list[], saving each result
1657 * as a new list[]. */
1658 static int o_glob(o_string *o, int n)
1664 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1666 return o_save_ptr_helper(o, n);
1667 pattern = o->data + o_get_last_ptr(o, n);
1668 debug_printf_glob("glob pattern '%s'\n", pattern);
1669 if (!glob_needed(pattern)) {
1671 o->length = unbackslash(pattern) - o->data;
1672 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1673 return o_save_ptr_helper(o, n);
1676 memset(&globdata, 0, sizeof(globdata));
1677 gr = glob(pattern, 0, NULL, &globdata);
1678 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1679 if (gr == GLOB_NOSPACE)
1680 bb_error_msg_and_die("out of memory during glob");
1681 if (gr == GLOB_NOMATCH) {
1682 globfree(&globdata);
1685 if (gr != 0) { /* GLOB_ABORTED ? */
1686 //TODO: testcase for bad glob pattern behavior
1687 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1689 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1690 char **argv = globdata.gl_pathv;
1691 o->length = pattern - o->data; /* "forget" pattern */
1693 o_addstr_with_NUL(o, *argv);
1694 n = o_save_ptr_helper(o, n);
1700 globfree(&globdata);
1702 debug_print_list("o_glob returning", o, n);
1706 /* If o->o_glob == 1, glob the string so far remembered.
1707 * Otherwise, just finish current list[] and start new */
1708 static int o_save_ptr(o_string *o, int n)
1710 if (o->o_glob) { /* if globbing is requested */
1711 /* If o->has_empty_slot, list[n] was already globbed
1712 * (if it was requested back then when it was filled)
1713 * so don't do that again! */
1714 if (!o->has_empty_slot)
1715 return o_glob(o, n); /* o_save_ptr_helper is inside */
1717 return o_save_ptr_helper(o, n);
1720 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1721 static char **o_finalize_list(o_string *o, int n)
1726 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1728 debug_print_list("finalized", o, n);
1729 debug_printf_expand("finalized n:%d\n", n);
1730 list = (char**)o->data;
1731 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1735 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1741 /* Expansion can recurse */
1742 #if ENABLE_HUSH_TICK
1743 static int process_command_subs(o_string *dest, const char *s);
1745 static char *expand_string_to_string(const char *str);
1747 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1748 parse_stream_dquoted(dest, input, dquote_end)
1750 static int parse_stream_dquoted(o_string *as_string,
1752 struct in_str *input,
1755 /* expand_strvec_to_strvec() takes a list of strings, expands
1756 * all variable references within and returns a pointer to
1757 * a list of expanded strings, possibly with larger number
1758 * of strings. (Think VAR="a b"; echo $VAR).
1759 * This new list is allocated as a single malloc block.
1760 * NULL-terminated list of char* pointers is at the beginning of it,
1761 * followed by strings themself.
1762 * Caller can deallocate entire list by single free(list). */
1764 /* Store given string, finalizing the word and starting new one whenever
1765 * we encounter IFS char(s). This is used for expanding variable values.
1766 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1767 static int expand_on_ifs(o_string *output, int n, const char *str)
1770 int word_len = strcspn(str, G.ifs);
1772 if (output->o_escape || !output->o_glob)
1773 o_addQstr(output, str, word_len);
1774 else /* protect backslashes against globbing up :) */
1775 o_addblock_duplicate_backslash(output, str, word_len);
1778 if (!*str) /* EOL - do not finalize word */
1780 o_addchr(output, '\0');
1781 debug_print_list("expand_on_ifs", output, n);
1782 n = o_save_ptr(output, n);
1783 str += strspn(str, G.ifs); /* skip ifs chars */
1785 debug_print_list("expand_on_ifs[1]", output, n);
1789 /* Helper to expand $((...)) and heredoc body. These act as if
1790 * they are in double quotes, with the exception that they are not :).
1791 * Just the rules are similar: "expand only $var and `cmd`"
1793 * Returns malloced string.
1794 * As an optimization, we return NULL if expansion is not needed.
1796 static char *expand_pseudo_dquoted(const char *str)
1799 struct in_str input;
1800 o_string dest = NULL_O_STRING;
1802 if (strchr(str, '$') == NULL
1803 #if ENABLE_HUSH_TICK
1804 && strchr(str, '`') == NULL
1810 /* We need to expand. Example:
1811 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1813 setup_string_in_str(&input, str);
1814 parse_stream_dquoted(NULL, &dest, &input, EOF);
1815 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1816 exp_str = expand_string_to_string(dest.data);
1817 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1818 o_free_unsafe(&dest);
1822 /* Expand all variable references in given string, adding words to list[]
1823 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1824 * to be filled). This routine is extremely tricky: has to deal with
1825 * variables/parameters with whitespace, $* and $@, and constructs like
1826 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1827 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1829 /* or_mask is either 0 (normal case) or 0x80
1830 * (expansion of right-hand side of assignment == 1-element expand.
1831 * It will also do no globbing, and thus we must not backslash-quote!) */
1833 char first_ch, ored_ch;
1841 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1842 debug_print_list("expand_vars_to_list", output, n);
1843 n = o_save_ptr(output, n);
1844 debug_print_list("expand_vars_to_list[0]", output, n);
1846 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1847 #if ENABLE_HUSH_TICK
1848 o_string subst_result = NULL_O_STRING;
1850 #if ENABLE_SH_MATH_SUPPORT
1851 char arith_buf[sizeof(arith_t)*3 + 2];
1853 o_addblock(output, arg, p - arg);
1854 debug_print_list("expand_vars_to_list[1]", output, n);
1856 p = strchr(p, SPECIAL_VAR_SYMBOL);
1858 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1859 /* "$@" is special. Even if quoted, it can still
1860 * expand to nothing (not even an empty string) */
1861 if ((first_ch & 0x7f) != '@')
1862 ored_ch |= first_ch;
1865 switch (first_ch & 0x7f) {
1866 /* Highest bit in first_ch indicates that var is double-quoted */
1868 val = utoa(G.root_pid);
1870 case '!': /* bg pid */
1871 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1873 case '?': /* exitcode */
1874 val = utoa(G.last_exitcode);
1876 case '#': /* argc */
1877 if (arg[1] != SPECIAL_VAR_SYMBOL)
1878 /* actually, it's a ${#var} */
1880 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1885 if (!G.global_argv[i])
1887 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1888 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1889 smallint sv = output->o_escape;
1890 /* unquoted var's contents should be globbed, so don't escape */
1891 output->o_escape = 0;
1892 while (G.global_argv[i]) {
1893 n = expand_on_ifs(output, n, G.global_argv[i]);
1894 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1895 if (G.global_argv[i++][0] && G.global_argv[i]) {
1896 /* this argv[] is not empty and not last:
1897 * put terminating NUL, start new word */
1898 o_addchr(output, '\0');
1899 debug_print_list("expand_vars_to_list[2]", output, n);
1900 n = o_save_ptr(output, n);
1901 debug_print_list("expand_vars_to_list[3]", output, n);
1904 output->o_escape = sv;
1906 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1907 * and in this case should treat it like '$*' - see 'else...' below */
1908 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1910 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1911 if (++i >= G.global_argc)
1913 o_addchr(output, '\0');
1914 debug_print_list("expand_vars_to_list[4]", output, n);
1915 n = o_save_ptr(output, n);
1917 } else { /* quoted $*: add as one word */
1919 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1920 if (!G.global_argv[++i])
1923 o_addchr(output, G.ifs[0]);
1927 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1928 /* "Empty variable", used to make "" etc to not disappear */
1932 #if ENABLE_HUSH_TICK
1933 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1936 //TODO: can we just stuff it into "output" directly?
1937 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1938 process_command_subs(&subst_result, arg);
1939 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1940 val = subst_result.data;
1943 #if ENABLE_SH_MATH_SUPPORT
1944 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1945 arith_eval_hooks_t hooks;
1950 arg++; /* skip '+' */
1951 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1952 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1954 exp_str = expand_pseudo_dquoted(arg);
1955 hooks.lookupvar = get_local_var_value;
1956 hooks.setvar = arith_set_local_var;
1957 hooks.endofname = endofname;
1958 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1962 const char *msg = "error in arithmetic";
1965 msg = "exponent less than 0";
1968 msg = "divide by 0";
1971 msg = "expression recursion loop detected";
1976 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1977 sprintf(arith_buf, arith_t_fmt, res);
1982 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1984 bool exp_len = false;
1985 bool exp_null = false;
1987 char exp_save = exp_save; /* for compiler */
1988 char exp_op = exp_op; /* for compiler */
1989 char *exp_word = exp_word; /* for compiler */
1993 arg[0] = first_ch & 0x7f;
1995 /* prepare for expansions */
1996 if (var[0] == '#') {
1997 /* handle length expansion ${#var} */
2001 /* maybe handle parameter expansion */
2002 exp_off = strcspn(var, ":-=+?%#");
2006 exp_save = var[exp_off];
2007 exp_null = exp_save == ':';
2008 exp_word = var + exp_off;
2011 exp_op = *exp_word++;
2012 var[exp_off] = '\0';
2016 /* lookup the variable in question */
2017 if (isdigit(var[0])) {
2018 /* handle_dollar() should have vetted var for us */
2020 if (i < G.global_argc)
2021 val = G.global_argv[i];
2022 /* else val remains NULL: $N with too big N */
2024 val = get_local_var_value(var);
2026 /* handle any expansions */
2028 debug_printf_expand("expand: length of '%s' = ", val);
2029 val = utoa(val ? strlen(val) : 0);
2030 debug_printf_expand("%s\n", val);
2031 } else if (exp_off) {
2032 if (exp_op == '%' || exp_op == '#') {
2034 /* we need to do a pattern match */
2037 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2038 if (exp_op == *exp_word) /* ## or %% */
2040 val = dyn_val = xstrdup(val);
2041 loc = scan(dyn_val, exp_word, zero);
2048 /* we need to do an expansion */
2049 int exp_test = (!val || (exp_null && !val[0]));
2051 exp_test = !exp_test;
2052 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2053 exp_null ? "true" : "false", exp_test);
2055 if (exp_op == '?') {
2056 //TODO: how interactive bash aborts expansion mid-command?
2057 /* ${var?[error_msg_if_unset]} */
2058 /* ${var:?[error_msg_if_unset_or_null]} */
2059 /* mimic bash message */
2060 die_if_script("%s: %s",
2062 exp_word[0] ? exp_word : "parameter null or not set"
2068 if (exp_op == '=') {
2069 /* ${var=[word]} or ${var:=[word]} */
2070 if (isdigit(var[0]) || var[0] == '#') {
2071 /* mimic bash message */
2072 die_if_script("$%s: cannot assign in this way", var);
2075 char *new_var = xasprintf("%s=%s", var, val);
2076 set_local_var(new_var, -1, 0);
2082 var[exp_off] = exp_save;
2086 #if ENABLE_HUSH_TICK
2089 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2090 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2092 /* unquoted var's contents should be globbed, so don't escape */
2093 smallint sv = output->o_escape;
2094 output->o_escape = 0;
2095 n = expand_on_ifs(output, n, val);
2097 output->o_escape = sv;
2099 } else { /* quoted $VAR, val will be appended below */
2100 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2103 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2105 o_addQstr(output, val, strlen(val));
2109 /* Do the check to avoid writing to a const string */
2110 if (*p != SPECIAL_VAR_SYMBOL)
2111 *p = SPECIAL_VAR_SYMBOL;
2113 #if ENABLE_HUSH_TICK
2114 o_free(&subst_result);
2117 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2120 debug_print_list("expand_vars_to_list[a]", output, n);
2121 /* this part is literal, and it was already pre-quoted
2122 * if needed (much earlier), do not use o_addQstr here! */
2123 o_addstr_with_NUL(output, arg);
2124 debug_print_list("expand_vars_to_list[b]", output, n);
2125 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2126 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2129 /* allow to reuse list[n] later without re-growth */
2130 output->has_empty_slot = 1;
2132 o_addchr(output, '\0');
2137 static char **expand_variables(char **argv, int or_mask)
2142 o_string output = NULL_O_STRING;
2144 if (or_mask & 0x100) {
2145 output.o_escape = 1; /* protect against globbing for "$var" */
2146 /* (unquoted $var will temporarily switch it off) */
2153 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2156 debug_print_list("expand_variables", &output, n);
2158 /* output.data (malloced in one block) gets returned in "list" */
2159 list = o_finalize_list(&output, n);
2160 debug_print_strings("expand_variables[1]", list);
2164 static char **expand_strvec_to_strvec(char **argv)
2166 return expand_variables(argv, 0x100);
2169 /* Used for expansion of right hand of assignments */
2170 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2172 static char *expand_string_to_string(const char *str)
2174 char *argv[2], **list;
2176 argv[0] = (char*)str;
2178 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2180 if (!list[0] || list[1])
2181 bb_error_msg_and_die("BUG in varexp2");
2182 /* actually, just move string 2*sizeof(char*) bytes back */
2183 overlapping_strcpy((char*)list, list[0]);
2184 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2188 /* Used for "eval" builtin */
2189 static char* expand_strvec_to_string(char **argv)
2193 list = expand_variables(argv, 0x80);
2194 /* Convert all NULs to spaces */
2199 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2200 bb_error_msg_and_die("BUG in varexp3");
2201 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2205 overlapping_strcpy((char*)list, list[0]);
2206 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2210 static char **expand_assignments(char **argv, int count)
2214 /* Expand assignments into one string each */
2215 for (i = 0; i < count; i++) {
2216 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2223 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2224 #define clean_up_after_re_execute() ((void)0)
2225 static void reset_traps_to_defaults(void)
2233 for (sig = 0; sig < NSIG; sig++) {
2237 G.traps[sig] = NULL;
2238 /* There is no signal for 0 (EXIT) */
2241 /* there was a trap handler, we are removing it
2242 * (if sig has non-DFL handling,
2243 * we don't need to do anything) */
2244 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2246 sigdelset(&G.blocked_set, sig);
2250 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2255 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2256 static void re_execute_shell(const char *s, int is_heredoc)
2258 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2259 char *heredoc_argv[4];
2260 struct variable *cur;
2261 char **argv, **pp, **pp2;
2265 argv = heredoc_argv;
2266 argv[0] = (char *) G.argv0_for_re_execing;
2267 argv[1] = (char *) "-<";
2268 argv[2] = (char *) s;
2270 pp = &argv[3]; /* used as pointer to empty environment */
2274 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2275 , (unsigned) G.root_pid
2276 , (unsigned) G.last_bg_pid
2277 , (unsigned) G.last_exitcode
2278 USE_HUSH_LOOPS(, G.depth_of_loop)
2280 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2281 * 3:-c 4:<cmd> <argN...> 5:NULL
2283 cnt = 5 + G.global_argc;
2284 for (cur = G.top_var; cur; cur = cur->next) {
2285 if (!cur->flg_export || cur->flg_read_only)
2288 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2289 *pp++ = (char *) G.argv0_for_re_execing;
2291 for (cur = G.top_var; cur; cur = cur->next) {
2292 if (cur->varstr == hush_version_str)
2294 if (cur->flg_read_only) {
2295 *pp++ = (char *) "-R";
2296 *pp++ = cur->varstr;
2297 } else if (!cur->flg_export) {
2298 *pp++ = (char *) "-V";
2299 *pp++ = cur->varstr;
2302 //TODO: pass functions
2303 /* We can pass activated traps here. Say, -Tnn:trap_string
2305 * However, POSIX says that subshells reset signals with traps
2307 * I tested bash-3.2 and it not only does that with true subshells
2308 * of the form ( list ), but with any forked children shells.
2309 * I set trap "echo W" WINCH; and then tried:
2311 * { echo 1; sleep 20; echo 2; } &
2312 * while true; do echo 1; sleep 20; echo 2; break; done &
2313 * true | { echo 1; sleep 20; echo 2; } | cat
2315 * In all these cases sending SIGWINCH to the child shell
2316 * did not run the trap. If I add trap "echo V" WINCH;
2317 * _inside_ group (just before echo 1), it works.
2319 * I conclude it means we don't need to pass active traps here.
2320 * exec syscall below resets them to SIG_DFL for us.
2322 *pp++ = (char *) "-c";
2324 pp2 = G.global_argv;
2327 /* *pp = NULL; - is already there */
2331 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2332 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2333 execve(bb_busybox_exec_path, argv, pp);
2334 /* Fallback. Useful for init=/bin/hush usage etc */
2335 if (argv[0][0] == '/')
2336 execve(argv[0], argv, pp);
2337 xfunc_error_retval = 127;
2338 bb_error_msg_and_die("can't re-execute the shell");
2341 static void clean_up_after_re_execute(void)
2343 char **pp = G.argv_from_re_execing;
2345 /* Must match re_execute_shell's allocations (if any) */
2347 G.argv_from_re_execing = NULL;
2350 #endif /* !BB_MMU */
2353 static void setup_heredoc(struct redir_struct *redir)
2355 struct fd_pair pair;
2358 /* the _body_ of heredoc (misleading field name) */
2359 const char *heredoc = redir->rd_filename;
2363 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2364 expanded = expand_pseudo_dquoted(heredoc);
2368 len = strlen(heredoc);
2370 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2372 xmove_fd(pair.rd, redir->rd_fd);
2374 /* Try writing without forking. Newer kernels have
2375 * dynamically growing pipes. Must use non-blocking write! */
2378 written = write(pair.wr, heredoc, len);
2389 ndelay_off(pair.wr);
2391 /* Okay, pipe buffer was not big enough */
2392 /* Note: we must not create a stray child (bastard? :)
2393 * for the unsuspecting parent process. Child creates a grandchild
2394 * and exits before parent execs the process which consumes heredoc
2395 * (that exec happens after we return from this function) */
2398 bb_perror_msg_and_die("vfork");
2401 pid = BB_MMU ? fork() : vfork();
2403 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2407 close(redir->rd_fd); /* read side of the pipe */
2409 full_write(pair.wr, heredoc, len); /* may loop or block */
2412 /* Delegate blocking writes to another process */
2413 disable_restore_tty_pgrp_on_exit();
2414 xmove_fd(pair.wr, STDOUT_FILENO);
2415 re_execute_shell(heredoc, 1);
2419 enable_restore_tty_pgrp_on_exit();
2420 clean_up_after_re_execute();
2423 wait(NULL); /* wait till child has died */
2426 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2427 * and stderr if they are redirected. */
2428 static int setup_redirects(struct command *prog, int squirrel[])
2431 struct redir_struct *redir;
2433 for (redir = prog->redirects; redir; redir = redir->next) {
2434 if (redir->rd_type == REDIRECT_HEREDOC2) {
2435 /* rd_fd<<HERE case */
2436 if (squirrel && redir->rd_fd < 3) {
2437 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2439 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2441 debug_printf_parse("set heredoc '%s'\n",
2442 redir->rd_filename);
2443 setup_heredoc(redir);
2447 if (redir->rd_dup == REDIRFD_TO_FILE) {
2448 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2450 if (redir->rd_filename == NULL) {
2451 /* Something went wrong in the parse.
2452 * Pretend it didn't happen */
2453 bb_error_msg("bug in redirect parse");
2456 mode = redir_table[redir->rd_type].mode;
2457 p = expand_string_to_string(redir->rd_filename);
2458 openfd = open_or_warn(p, mode);
2461 /* this could get lost if stderr has been redirected, but
2462 * bash and ash both lose it as well (though zsh doesn't!) */
2463 //what the above comment tries to say?
2467 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2468 openfd = redir->rd_dup;
2471 if (openfd != redir->rd_fd) {
2472 if (squirrel && redir->rd_fd < 3) {
2473 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2475 if (openfd == REDIRFD_CLOSE) {
2476 /* "n>-" means "close me" */
2477 close(redir->rd_fd);
2479 xdup2(openfd, redir->rd_fd);
2480 if (redir->rd_dup == REDIRFD_TO_FILE)
2488 static void restore_redirects(int squirrel[])
2491 for (i = 0; i < 3; i++) {
2494 /* We simply die on error */
2502 #define free_pipe_list(head, indent) free_pipe_list(head)
2503 #define free_pipe(pi, indent) free_pipe(pi)
2505 static void free_pipe_list(struct pipe *head, int indent);
2507 /* Return code is the exit status of the pipe */
2508 static void free_pipe(struct pipe *pi, int indent)
2511 struct command *command;
2512 struct redir_struct *r, *rnext;
2515 if (pi->stopped_cmds > 0) /* why? */
2517 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2518 for (i = 0; i < pi->num_cmds; i++) {
2519 command = &pi->cmds[i];
2520 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2521 if (command->argv) {
2522 for (a = 0, p = command->argv; *p; a++, p++) {
2523 debug_printf_clean("%s argv[%d] = %s\n",
2524 indenter(indent), a, *p);
2526 free_strings(command->argv);
2527 command->argv = NULL;
2529 /* not "else if": on syntax error, we may have both! */
2530 if (command->group) {
2531 debug_printf_clean("%s begin group (grp_type:%d)\n",
2532 indenter(indent), command->grp_type);
2533 free_pipe_list(command->group, indent+3);
2534 debug_printf_clean("%s end group\n", indenter(indent));
2535 command->group = NULL;
2538 free(command->group_as_string);
2539 command->group_as_string = NULL;
2541 for (r = command->redirects; r; r = rnext) {
2542 debug_printf_clean("%s redirect %d%s", indenter(indent),
2543 r->fd, redir_table[r->rd_type].descrip);
2544 /* guard against the case >$FOO, where foo is unset or blank */
2545 if (r->rd_filename) {
2546 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2547 free(r->rd_filename);
2548 r->rd_filename = NULL;
2550 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2554 command->redirects = NULL;
2556 free(pi->cmds); /* children are an array, they get freed all at once */
2564 static void free_pipe_list(struct pipe *head, int indent)
2566 struct pipe *pi, *next;
2568 for (pi = head; pi; pi = next) {
2570 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2572 free_pipe(pi, indent);
2573 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2575 /*pi->next = NULL;*/
2582 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2583 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2584 #define pseudo_exec(nommu_save, command, argv_expanded) \
2585 pseudo_exec(command, argv_expanded)
2588 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2590 * XXX no exit() here. If you don't exec, use _exit instead.
2591 * The at_exit handlers apparently confuse the calling process,
2592 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2593 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2594 char **argv, int assignment_cnt,
2595 char **argv_expanded) NORETURN;
2596 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2597 char **argv, int assignment_cnt,
2598 char **argv_expanded)
2602 /* Case when we are here: ... | var=val | ... */
2603 if (!argv[assignment_cnt])
2604 _exit(EXIT_SUCCESS);
2606 new_env = expand_assignments(argv, assignment_cnt);
2608 putenv_all(new_env);
2609 free(new_env); /* optional */
2611 nommu_save->new_env = new_env;
2612 nommu_save->old_env = putenv_all_and_save_old(new_env);
2614 if (argv_expanded) {
2615 argv = argv_expanded;
2617 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2619 nommu_save->argv = argv;
2623 /* On NOMMU, we must never block!
2624 * Example: { sleep 99999 | read line } & echo Ok
2625 * read builtin will block on read syscall, leaving parent blocked
2626 * in vfork. Therefore we can't do this:
2629 /* Check if the command matches any of the builtins.
2630 * Depending on context, this might be redundant. But it's
2631 * easier to waste a few CPU cycles than it is to figure out
2632 * if this is one of those cases.
2636 const struct built_in_command *x;
2637 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2638 if (strcmp(argv[0], x->cmd) == 0) {
2639 debug_printf_exec("running builtin '%s'\n",
2641 rcode = x->function(argv);
2649 #if ENABLE_FEATURE_SH_STANDALONE
2650 /* Check if the command matches any busybox applets */
2651 if (strchr(argv[0], '/') == NULL) {
2652 int a = find_applet_by_name(argv[0]);
2654 #if BB_MMU /* see above why on NOMMU it is not allowed */
2655 if (APPLET_IS_NOEXEC(a)) {
2656 debug_printf_exec("running applet '%s'\n", argv[0]);
2657 run_applet_no_and_exit(a, argv);
2660 /* Re-exec ourselves */
2661 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2662 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2663 execv(bb_busybox_exec_path, argv);
2664 /* If they called chroot or otherwise made the binary no longer
2665 * executable, fall through */
2670 debug_printf_exec("execing '%s'\n", argv[0]);
2671 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2672 execvp(argv[0], argv);
2673 bb_perror_msg("can't exec '%s'", argv[0]);
2674 _exit(EXIT_FAILURE);
2677 static int run_list(struct pipe *pi);
2679 /* Called after [v]fork() in run_pipe
2681 static void pseudo_exec(nommu_save_t *nommu_save,
2682 struct command *command,
2683 char **argv_expanded) NORETURN;
2684 static void pseudo_exec(nommu_save_t *nommu_save,
2685 struct command *command,
2686 char **argv_expanded)
2688 if (command->argv) {
2689 pseudo_exec_argv(nommu_save, command->argv,
2690 command->assignment_cnt, argv_expanded);
2693 if (command->group) {
2694 /* Cases when we are here:
2697 * ... | ( list ) | ...
2698 * ... | { list } | ...
2702 debug_printf_exec("pseudo_exec: run_list\n");
2703 reset_traps_to_defaults();
2704 rcode = run_list(command->group);
2705 /* OK to leak memory by not calling free_pipe_list,
2706 * since this process is about to exit */
2709 re_execute_shell(command->group_as_string, 0);
2713 /* Case when we are here: ... | >file */
2714 debug_printf_exec("pseudo_exec'ed null command\n");
2715 _exit(EXIT_SUCCESS);
2719 static const char *get_cmdtext(struct pipe *pi)
2725 /* This is subtle. ->cmdtext is created only on first backgrounding.
2726 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2727 * On subsequent bg argv is trashed, but we won't use it */
2730 argv = pi->cmds[0].argv;
2731 if (!argv || !argv[0]) {
2732 pi->cmdtext = xzalloc(1);
2737 do len += strlen(*argv) + 1; while (*++argv);
2738 pi->cmdtext = p = xmalloc(len);
2739 argv = pi->cmds[0].argv;
2741 len = strlen(*argv);
2742 memcpy(p, *argv, len);
2750 static void insert_bg_job(struct pipe *pi)
2752 struct pipe *thejob;
2755 /* Linear search for the ID of the job to use */
2757 for (thejob = G.job_list; thejob; thejob = thejob->next)
2758 if (thejob->jobid >= pi->jobid)
2759 pi->jobid = thejob->jobid + 1;
2761 /* Add thejob to the list of running jobs */
2763 thejob = G.job_list = xmalloc(sizeof(*thejob));
2765 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2767 thejob->next = xmalloc(sizeof(*thejob));
2768 thejob = thejob->next;
2771 /* Physically copy the struct job */
2772 memcpy(thejob, pi, sizeof(struct pipe));
2773 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2774 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2775 for (i = 0; i < pi->num_cmds; i++) {
2776 // TODO: do we really need to have so many fields which are just dead weight
2777 // at execution stage?
2778 thejob->cmds[i].pid = pi->cmds[i].pid;
2779 /* all other fields are not used and stay zero */
2781 thejob->next = NULL;
2782 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2784 /* We don't wait for background thejobs to return -- append it
2785 to the list of backgrounded thejobs and leave it alone */
2786 if (G_interactive_fd)
2787 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2788 G.last_bg_pid = thejob->cmds[0].pid;
2789 G.last_jobid = thejob->jobid;
2792 static void remove_bg_job(struct pipe *pi)
2794 struct pipe *prev_pipe;
2796 if (pi == G.job_list) {
2797 G.job_list = pi->next;
2799 prev_pipe = G.job_list;
2800 while (prev_pipe->next != pi)
2801 prev_pipe = prev_pipe->next;
2802 prev_pipe->next = pi->next;
2805 G.last_jobid = G.job_list->jobid;
2810 /* Remove a backgrounded job */
2811 static void delete_finished_bg_job(struct pipe *pi)
2814 pi->stopped_cmds = 0;
2820 /* Check to see if any processes have exited -- if they
2821 * have, figure out why and see if a job has completed */
2822 static int checkjobs(struct pipe* fg_pipe)
2832 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2835 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2836 // /* avoid doing syscall, nothing there anyway */
2839 attributes = WUNTRACED;
2840 if (fg_pipe == NULL)
2841 attributes |= WNOHANG;
2843 /* Do we do this right?
2844 * bash-3.00# sleep 20 | false
2846 * [3]+ Stopped sleep 20 | false
2847 * bash-3.00# echo $?
2848 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2851 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2852 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2853 // + killall -STOP cat
2860 // i = G.count_SIGCHLD;
2861 childpid = waitpid(-1, &status, attributes);
2862 if (childpid <= 0) {
2863 if (childpid && errno != ECHILD)
2864 bb_perror_msg("waitpid");
2865 // else /* Until next SIGCHLD, waitpid's are useless */
2866 // G.handled_SIGCHLD = i;
2869 dead = WIFEXITED(status) || WIFSIGNALED(status);
2872 if (WIFSTOPPED(status))
2873 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2874 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2875 if (WIFSIGNALED(status))
2876 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2877 childpid, WTERMSIG(status), WEXITSTATUS(status));
2878 if (WIFEXITED(status))
2879 debug_printf_jobs("pid %d exited, exitcode %d\n",
2880 childpid, WEXITSTATUS(status));
2882 /* Were we asked to wait for fg pipe? */
2884 for (i = 0; i < fg_pipe->num_cmds; i++) {
2885 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2886 if (fg_pipe->cmds[i].pid != childpid)
2888 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2890 fg_pipe->cmds[i].pid = 0;
2891 fg_pipe->alive_cmds--;
2892 if (i == fg_pipe->num_cmds - 1) {
2893 /* last process gives overall exitstatus */
2894 rcode = WEXITSTATUS(status);
2895 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2898 fg_pipe->cmds[i].is_stopped = 1;
2899 fg_pipe->stopped_cmds++;
2901 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2902 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2903 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2904 /* All processes in fg pipe have exited/stopped */
2906 if (fg_pipe->alive_cmds)
2907 insert_bg_job(fg_pipe);
2911 /* There are still running processes in the fg pipe */
2912 goto wait_more; /* do waitpid again */
2914 /* it wasnt fg_pipe, look for process in bg pipes */
2918 /* We asked to wait for bg or orphaned children */
2919 /* No need to remember exitcode in this case */
2920 for (pi = G.job_list; pi; pi = pi->next) {
2921 for (i = 0; i < pi->num_cmds; i++) {
2922 if (pi->cmds[i].pid == childpid)
2923 goto found_pi_and_prognum;
2926 /* Happens when shell is used as init process (init=/bin/sh) */
2927 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2928 continue; /* do waitpid again */
2930 found_pi_and_prognum:
2933 pi->cmds[i].pid = 0;
2935 if (!pi->alive_cmds) {
2936 if (G_interactive_fd)
2937 printf(JOB_STATUS_FORMAT, pi->jobid,
2938 "Done", pi->cmdtext);
2939 delete_finished_bg_job(pi);
2943 pi->cmds[i].is_stopped = 1;
2947 } /* while (waitpid succeeds)... */
2953 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2956 int rcode = checkjobs(fg_pipe);
2957 /* Job finished, move the shell to the foreground */
2958 p = getpgid(0); /* pgid of our process */
2959 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2960 tcsetpgrp(G_interactive_fd, p);
2965 /* Start all the jobs, but don't wait for anything to finish.
2968 * Return code is normally -1, when the caller has to wait for children
2969 * to finish to determine the exit status of the pipe. If the pipe
2970 * is a simple builtin command, however, the action is done by the
2971 * time run_pipe returns, and the exit code is provided as the
2974 * Returns -1 only if started some children. IOW: we have to
2975 * mask out retvals of builtins etc with 0xff!
2977 * The only case when we do not need to [v]fork is when the pipe
2978 * is single, non-backgrounded, non-subshell command. Examples:
2979 * cmd ; ... { list } ; ...
2980 * cmd && ... { list } && ...
2981 * cmd || ... { list } || ...
2982 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2983 * or (if SH_STANDALONE) an applet, and we can run the { list }
2984 * with run_list(). If it isn't one of these, we fork and exec cmd.
2986 * Cases when we must fork:
2987 * non-single: cmd | cmd
2988 * backgrounded: cmd & { list } &
2989 * subshell: ( list ) [&]
2991 static int run_pipe(struct pipe *pi)
2993 static const char *const null_ptr = NULL;
2996 int pipefds[2]; /* pipefds[0] is for reading */
2997 struct command *command;
2998 char **argv_expanded;
3001 /* it is not always needed, but we aim to smaller code */
3002 int squirrel[] = { -1, -1, -1 };
3005 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3007 USE_HUSH_JOB(pi->pgrp = -1;)
3008 pi->stopped_cmds = 0;
3009 command = &(pi->cmds[0]);
3010 argv_expanded = NULL;
3012 if (pi->num_cmds != 1
3013 || pi->followup == PIPE_BG
3014 || command->grp_type == GRP_SUBSHELL
3021 debug_printf_exec(": group:%p argv:'%s'\n",
3022 command->group, command->argv ? command->argv[0] : "NONE");
3024 if (command->group) {
3025 #if ENABLE_HUSH_FUNCTIONS
3026 if (command->grp_type == GRP_FUNCTION) {
3027 /* func () { list } */
3028 bb_error_msg("here we ought to remember function definition, and go on");
3029 return EXIT_SUCCESS;
3033 debug_printf("non-subshell group\n");
3034 rcode = 1; /* exitcode if redir failed */
3035 if (setup_redirects(command, squirrel) == 0) {
3036 debug_printf_exec(": run_list\n");
3037 rcode = run_list(command->group) & 0xff;
3038 debug_printf_exec("run_pipe return %d\n", rcode);
3040 restore_redirects(squirrel);
3041 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3045 argv = command->argv ? command->argv : (char **) &null_ptr;
3047 const struct built_in_command *x;
3048 char **new_env = NULL;
3049 char **old_env = NULL;
3051 if (argv[command->assignment_cnt] == NULL) {
3052 /* Assignments, but no command */
3053 /* Ensure redirects take effect. Try "a=t >file" */
3054 rcode = setup_redirects(command, squirrel);
3055 restore_redirects(squirrel);
3056 /* Set shell variables */
3058 p = expand_string_to_string(*argv);
3059 debug_printf_exec("set shell var:'%s'->'%s'\n",
3061 set_local_var(p, 0, 0);
3064 /* Do we need to flag set_local_var() errors?
3065 * "assignment to readonly var" and "putenv error"
3067 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3071 /* Expand the rest into (possibly) many strings each */
3072 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3074 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
3075 if (strcmp(argv_expanded[0], x->cmd) != 0)
3077 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3078 debug_printf("exec with redirects only\n");
3079 rcode = setup_redirects(command, NULL);
3080 goto clean_up_and_ret1;
3082 debug_printf("builtin inline %s\n", argv_expanded[0]);
3083 /* XXX setup_redirects acts on file descriptors, not FILEs.
3084 * This is perfect for work that comes after exec().
3085 * Is it really safe for inline use? Experimentally,
3086 * things seem to work with glibc. */
3087 rcode = setup_redirects(command, squirrel);
3089 new_env = expand_assignments(argv, command->assignment_cnt);
3090 old_env = putenv_all_and_save_old(new_env);
3091 debug_printf_exec(": builtin '%s' '%s'...\n",
3092 x->cmd, argv_expanded[1]);
3093 rcode = x->function(argv_expanded) & 0xff;
3095 #if ENABLE_FEATURE_SH_STANDALONE
3098 restore_redirects(squirrel);
3099 free_strings_and_unsetenv(new_env, 1);
3100 putenv_all(old_env);
3101 /* Free the pointers, but the strings themselves
3102 * are in environ now, don't use free_strings! */
3105 free(argv_expanded);
3106 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3107 debug_printf_exec("run_pipe return %d\n", rcode);
3110 #if ENABLE_FEATURE_SH_STANDALONE
3111 i = find_applet_by_name(argv_expanded[0]);
3112 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3113 rcode = setup_redirects(command, squirrel);
3115 save_nofork_data(&G.nofork_save);
3116 new_env = expand_assignments(argv, command->assignment_cnt);
3117 old_env = putenv_all_and_save_old(new_env);
3118 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3119 argv_expanded[0], argv_expanded[1]);
3120 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3122 goto clean_up_and_ret;
3125 /* It is neither builtin nor applet. We must fork. */
3129 /* NB: argv_expanded may already be created, and that
3130 * might include `cmd` runs! Do not rerun it! We *must*
3131 * use argv_expanded if it's non-NULL */
3133 /* Going to fork a child per each pipe member */
3137 for (i = 0; i < pi->num_cmds; i++) {
3139 volatile nommu_save_t nommu_save;
3140 nommu_save.new_env = NULL;
3141 nommu_save.old_env = NULL;
3142 nommu_save.argv = NULL;
3144 command = &(pi->cmds[i]);
3145 if (command->argv) {
3146 debug_printf_exec(": pipe member '%s' '%s'...\n",
3147 command->argv[0], command->argv[1]);
3149 debug_printf_exec(": pipe member with no argv\n");
3152 /* pipes are inserted between pairs of commands */
3155 if ((i + 1) < pi->num_cmds)
3158 command->pid = BB_MMU ? fork() : vfork();
3159 if (!command->pid) { /* child */
3161 disable_restore_tty_pgrp_on_exit();
3163 /* Every child adds itself to new process group
3164 * with pgid == pid_of_first_child_in_pipe */
3165 if (G.run_list_level == 1 && G_interactive_fd) {
3168 if (pgrp < 0) /* true for 1st process only */
3170 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3171 /* We do it in *every* child, not just first,
3173 tcsetpgrp(G_interactive_fd, pgrp);
3177 xmove_fd(nextin, 0);
3178 xmove_fd(pipefds[1], 1); /* write end */
3180 close(pipefds[0]); /* read end */
3181 /* Like bash, explicit redirects override pipes,
3182 * and the pipe fd is available for dup'ing. */
3183 if (setup_redirects(command, NULL))
3186 /* Restore default handlers just prior to exec */
3187 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3189 /* Stores to nommu_save list of env vars putenv'ed
3190 * (NOMMU, on MMU we don't need that) */
3191 /* cast away volatility... */
3192 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3193 /* pseudo_exec() does not return */
3196 /* parent or error */
3197 enable_restore_tty_pgrp_on_exit();
3199 /* Clean up after vforked child */
3200 clean_up_after_re_execute();
3201 free(nommu_save.argv);
3202 free_strings_and_unsetenv(nommu_save.new_env, 1);
3203 putenv_all(nommu_save.old_env);
3204 /* Free the pointers, but the strings themselves
3205 * are in environ now, don't use free_strings! */
3206 free(nommu_save.old_env);
3208 free(argv_expanded);
3209 argv_expanded = NULL;
3210 if (command->pid < 0) { /* [v]fork failed */
3211 /* Clearly indicate, was it fork or vfork */
3212 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3216 /* Second and next children need to know pid of first one */
3218 pi->pgrp = command->pid;
3224 if ((i + 1) < pi->num_cmds)
3225 close(pipefds[1]); /* write end */
3226 /* Pass read (output) pipe end to next iteration */
3227 nextin = pipefds[0];
3230 if (!pi->alive_cmds) {
3231 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3235 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3239 #ifndef debug_print_tree
3240 static void debug_print_tree(struct pipe *pi, int lvl)
3242 static const char *const PIPE[] = {
3248 static const char *RES[] = {
3249 [RES_NONE ] = "NONE" ,
3252 [RES_THEN ] = "THEN" ,
3253 [RES_ELIF ] = "ELIF" ,
3254 [RES_ELSE ] = "ELSE" ,
3257 #if ENABLE_HUSH_LOOPS
3258 [RES_FOR ] = "FOR" ,
3259 [RES_WHILE] = "WHILE",
3260 [RES_UNTIL] = "UNTIL",
3262 [RES_DONE ] = "DONE" ,
3264 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3267 #if ENABLE_HUSH_CASE
3268 [RES_CASE ] = "CASE" ,
3269 [RES_MATCH] = "MATCH",
3270 [RES_CASEI] = "CASEI",
3271 [RES_ESAC ] = "ESAC" ,
3273 [RES_XXXX ] = "XXXX" ,
3274 [RES_SNTX ] = "SNTX" ,
3276 static const char *const GRPTYPE[] = {
3279 #if ENABLE_HUSH_FUNCTIONS
3288 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3289 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3291 while (prn < pi->num_cmds) {
3292 struct command *command = &pi->cmds[prn];
3293 char **argv = command->argv;
3295 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3297 command->assignment_cnt);
3298 if (command->group) {
3299 fprintf(stderr, " group %s: (argv=%p)\n",
3300 GRPTYPE[command->grp_type],
3302 debug_print_tree(command->group, lvl+1);
3306 if (argv) while (*argv) {
3307 fprintf(stderr, " '%s'", *argv);
3310 fprintf(stderr, "\n");
3319 /* NB: called by pseudo_exec, and therefore must not modify any
3320 * global data until exec/_exit (we can be a child after vfork!) */
3321 static int run_list(struct pipe *pi)
3323 #if ENABLE_HUSH_CASE
3324 char *case_word = NULL;
3326 #if ENABLE_HUSH_LOOPS
3327 struct pipe *loop_top = NULL;
3328 char *for_varname = NULL;
3329 char **for_lcur = NULL;
3330 char **for_list = NULL;
3332 smallint last_followup;
3334 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3335 smalluint cond_code = 0;
3337 enum { cond_code = 0 };
3340 smallint rword; /* enum reserved_style */
3341 smallint last_rword; /* ditto */
3344 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3346 #if ENABLE_HUSH_LOOPS
3347 /* Check syntax for "for" */
3348 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3349 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3351 /* current word is FOR or IN (BOLD in comments below) */
3352 if (cpipe->next == NULL) {
3353 syntax_error("malformed for");
3354 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3357 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3358 if (cpipe->next->res_word == RES_DO)
3360 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3361 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3362 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3364 syntax_error("malformed for");
3365 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3371 /* Past this point, all code paths should jump to ret: label
3372 * in order to return, no direct "return" statements please.
3373 * This helps to ensure that no memory is leaked. */
3375 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3378 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3379 * We are saving state before entering outermost list ("while...done")
3380 * so that ctrl-Z will correctly background _entire_ outermost list,
3381 * not just a part of it (like "sleep 1 | exit 2") */
3382 if (++G.run_list_level == 1 && G_interactive_fd) {
3383 if (sigsetjmp(G.toplevel_jb, 1)) {
3384 /* ctrl-Z forked and we are parent; or ctrl-C.
3385 * Sighandler has longjmped us here */
3386 signal(SIGINT, SIG_IGN);
3387 signal(SIGTSTP, SIG_IGN);
3388 /* Restore level (we can be coming from deep inside
3390 G.run_list_level = 1;
3391 #if ENABLE_FEATURE_SH_STANDALONE
3392 if (G.nofork_save.saved) { /* if save area is valid */
3393 debug_printf_jobs("exiting nofork early\n");
3394 restore_nofork_data(&G.nofork_save);
3397 //// if (G.ctrl_z_flag) {
3398 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3399 //// * Remember this child as background job */
3400 //// insert_bg_job(pi);
3402 /* ctrl-C. We just stop doing whatever we were doing */
3405 USE_HUSH_LOOPS(loop_top = NULL;)
3406 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3410 //// /* ctrl-Z handler will store pid etc in pi */
3411 //// G.toplevel_list = pi;
3412 //// G.ctrl_z_flag = 0;
3413 #if ENABLE_FEATURE_SH_STANDALONE
3414 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3416 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3417 //// signal(SIGINT, handler_ctrl_c);
3423 last_rword = RES_XXXX;
3425 last_followup = PIPE_SEQ;
3426 rcode = G.last_exitcode;
3428 /* Go through list of pipes, (maybe) executing them. */
3429 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3433 IF_HAS_KEYWORDS(rword = pi->res_word;)
3434 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3435 rword, cond_code, last_rword);
3436 #if ENABLE_HUSH_LOOPS
3437 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3438 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3440 /* start of a loop: remember where loop starts */
3445 /* Still in the same "if...", "then..." or "do..." branch? */
3446 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3447 if ((rcode == 0 && last_followup == PIPE_OR)
3448 || (rcode != 0 && last_followup == PIPE_AND)
3450 /* It is "<true> || CMD" or "<false> && CMD"
3451 * and we should not execute CMD */
3452 debug_printf_exec("skipped cmd because of || or &&\n");
3453 last_followup = pi->followup;
3457 last_followup = pi->followup;
3458 IF_HAS_KEYWORDS(last_rword = rword;)
3461 if (rword == RES_THEN) {
3462 /* if false; then ... fi has exitcode 0! */
3463 G.last_exitcode = rcode = EXIT_SUCCESS;
3464 /* "if <false> THEN cmd": skip cmd */
3468 if (rword == RES_ELSE || rword == RES_ELIF) {
3469 /* "if <true> then ... ELSE/ELIF cmd":
3470 * skip cmd and all following ones */
3475 #if ENABLE_HUSH_LOOPS
3476 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3478 /* first loop through for */
3480 static const char encoded_dollar_at[] ALIGN1 = {
3481 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3482 }; /* encoded representation of "$@" */
3483 static const char *const encoded_dollar_at_argv[] = {
3484 encoded_dollar_at, NULL
3485 }; /* argv list with one element: "$@" */
3488 vals = (char**)encoded_dollar_at_argv;
3489 if (pi->next->res_word == RES_IN) {
3490 /* if no variable values after "in" we skip "for" */
3491 if (!pi->next->cmds[0].argv) {
3492 G.last_exitcode = rcode = EXIT_SUCCESS;
3493 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3496 vals = pi->next->cmds[0].argv;
3497 } /* else: "for var; do..." -> assume "$@" list */
3498 /* create list of variable values */
3499 debug_print_strings("for_list made from", vals);
3500 for_list = expand_strvec_to_strvec(vals);
3501 for_lcur = for_list;
3502 debug_print_strings("for_list", for_list);
3503 for_varname = pi->cmds[0].argv[0];
3504 pi->cmds[0].argv[0] = NULL;
3506 free(pi->cmds[0].argv[0]);
3508 /* "for" loop is over, clean up */
3512 pi->cmds[0].argv[0] = for_varname;
3515 /* Insert next value from for_lcur */
3516 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3517 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3518 pi->cmds[0].assignment_cnt = 1;
3520 if (rword == RES_IN) {
3521 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3523 if (rword == RES_DONE) {
3524 continue; /* "done" has no cmds too */
3527 #if ENABLE_HUSH_CASE
3528 if (rword == RES_CASE) {
3529 case_word = expand_strvec_to_string(pi->cmds->argv);
3532 if (rword == RES_MATCH) {
3535 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3537 /* all prev words didn't match, does this one match? */
3538 argv = pi->cmds->argv;
3540 char *pattern = expand_string_to_string(*argv);
3541 /* TODO: which FNM_xxx flags to use? */
3542 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3544 if (cond_code == 0) { /* match! we will execute this branch */
3545 free(case_word); /* make future "word)" stop */
3553 if (rword == RES_CASEI) { /* inside of a case branch */
3555 continue; /* not matched yet, skip this pipe */
3558 /* Just pressing <enter> in shell should check for jobs.
3559 * OTOH, in non-interactive shell this is useless
3560 * and only leads to extra job checks */
3561 if (pi->num_cmds == 0) {
3562 if (G_interactive_fd)
3563 goto check_jobs_and_continue;
3567 /* After analyzing all keywords and conditions, we decided
3568 * to execute this pipe. NB: have to do checkjobs(NULL)
3569 * after run_pipe to collect any background children,
3570 * even if list execution is to be stopped. */
3571 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3574 #if ENABLE_HUSH_LOOPS
3575 G.flag_break_continue = 0;
3577 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3579 /* We only ran a builtin: rcode is already known
3580 * and we don't need to wait for anything. */
3581 G.last_exitcode = rcode;
3582 debug_printf_exec(": builtin exitcode %d\n", rcode);
3583 check_and_run_traps(0);
3584 #if ENABLE_HUSH_LOOPS
3585 /* Was it "break" or "continue"? */
3586 if (G.flag_break_continue) {
3587 smallint fbc = G.flag_break_continue;
3588 /* We might fall into outer *loop*,
3589 * don't want to break it too */
3591 G.depth_break_continue--;
3592 if (G.depth_break_continue == 0)
3593 G.flag_break_continue = 0;
3594 /* else: e.g. "continue 2" should *break* once, *then* continue */
3595 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3596 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3597 goto check_jobs_and_break;
3598 /* "continue": simulate end of loop */
3603 } else if (pi->followup == PIPE_BG) {
3604 /* What does bash do with attempts to background builtins? */
3605 /* even bash 3.2 doesn't do that well with nested bg:
3606 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3607 * I'm NOT treating inner &'s as jobs */
3608 check_and_run_traps(0);
3610 if (G.run_list_level == 1)
3613 G.last_exitcode = rcode = EXIT_SUCCESS;
3614 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3617 if (G.run_list_level == 1 && G_interactive_fd) {
3618 /* Waits for completion, then fg's main shell */
3619 rcode = checkjobs_and_fg_shell(pi);
3620 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3621 check_and_run_traps(0);
3624 { /* This one just waits for completion */
3625 rcode = checkjobs(pi);
3626 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3627 check_and_run_traps(0);
3629 G.last_exitcode = rcode;
3633 /* Analyze how result affects subsequent commands */
3635 if (rword == RES_IF || rword == RES_ELIF)
3638 #if ENABLE_HUSH_LOOPS
3639 /* Beware of "while false; true; do ..."! */
3640 if (pi->next && pi->next->res_word == RES_DO) {
3641 if (rword == RES_WHILE) {
3643 /* "while false; do...done" - exitcode 0 */
3644 G.last_exitcode = rcode = EXIT_SUCCESS;
3645 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3646 goto check_jobs_and_break;
3649 if (rword == RES_UNTIL) {
3651 debug_printf_exec(": until expr is true: breaking\n");
3652 check_jobs_and_break:
3660 check_jobs_and_continue:
3665 //// if (G.ctrl_z_flag) {
3666 //// /* ctrl-Z forked somewhere in the past, we are the child,
3667 //// * and now we completed running the list. Exit. */
3673 //// if (!G.run_list_level && G_interactive_fd) {
3674 //// signal(SIGTSTP, SIG_IGN);
3675 //// signal(SIGINT, SIG_IGN);
3678 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3679 #if ENABLE_HUSH_LOOPS
3684 #if ENABLE_HUSH_CASE
3690 /* Select which version we will use */
3691 static int run_and_free_list(struct pipe *pi)
3694 debug_printf_exec("run_and_free_list entered\n");
3696 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3697 rcode = run_list(pi);
3699 /* free_pipe_list has the side effect of clearing memory.
3700 * In the long run that function can be merged with run_list,
3701 * but doing that now would hobble the debugging effort. */
3702 free_pipe_list(pi, /* indent: */ 0);
3703 debug_printf_exec("run_and_free_list return %d\n", rcode);
3708 static struct pipe *new_pipe(void)
3711 pi = xzalloc(sizeof(struct pipe));
3712 /*pi->followup = 0; - deliberately invalid value */
3713 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3717 /* Command (member of a pipe) is complete. The only possible error here
3718 * is out of memory, in which case xmalloc exits. */
3719 static int done_command(struct parse_context *ctx)
3721 /* The command is really already in the pipe structure, so
3722 * advance the pipe counter and make a new, null command. */
3723 struct pipe *pi = ctx->pipe;
3724 struct command *command = ctx->command;
3727 if (command->group == NULL
3728 && command->argv == NULL
3729 && command->redirects == NULL
3731 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3732 memset(command, 0, sizeof(*command)); /* paranoia */
3733 return pi->num_cmds;
3736 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3737 //debug_print_tree(ctx->list_head, 20);
3739 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3742 /* Only real trickiness here is that the uncommitted
3743 * command structure is not counted in pi->num_cmds. */
3744 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3745 command = &pi->cmds[pi->num_cmds];
3746 memset(command, 0, sizeof(*command));
3748 ctx->command = command;
3749 /* but ctx->pipe and ctx->list_head remain unchanged */
3751 return pi->num_cmds; /* used only for 0/nonzero check */
3754 static void done_pipe(struct parse_context *ctx, pipe_style type)
3758 debug_printf_parse("done_pipe entered, followup %d\n", type);
3759 /* Close previous command */
3760 not_null = done_command(ctx);
3761 ctx->pipe->followup = type;
3763 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3764 ctx->ctx_inverted = 0;
3765 ctx->pipe->res_word = ctx->ctx_res_w;
3768 /* Without this check, even just <enter> on command line generates
3769 * tree of three NOPs (!). Which is harmless but annoying.
3770 * IOW: it is safe to do it unconditionally.
3771 * RES_NONE case is for "for a in; do ..." (empty IN set)
3772 * and other cases to work. */
3775 || ctx->ctx_res_w == RES_FI
3776 || ctx->ctx_res_w == RES_DONE
3777 || ctx->ctx_res_w == RES_FOR
3778 || ctx->ctx_res_w == RES_IN
3779 || ctx->ctx_res_w == RES_ESAC
3783 debug_printf_parse("done_pipe: adding new pipe: "
3784 "not_null:%d ctx->ctx_res_w:%d\n",
3785 not_null, ctx->ctx_res_w);
3787 ctx->pipe->next = new_p;
3789 /* RES_THEN, RES_DO etc are "sticky" -
3790 * they remain set for commands inside if/while.
3791 * This is used to control execution.
3792 * RES_FOR and RES_IN are NOT sticky (needed to support
3793 * cases where variable or value happens to match a keyword):
3795 #if ENABLE_HUSH_LOOPS
3796 if (ctx->ctx_res_w == RES_FOR
3797 || ctx->ctx_res_w == RES_IN)
3798 ctx->ctx_res_w = RES_NONE;
3800 #if ENABLE_HUSH_CASE
3801 if (ctx->ctx_res_w == RES_MATCH)
3802 ctx->ctx_res_w = RES_CASEI;
3804 ctx->command = NULL; /* trick done_command below */
3805 /* Create the memory for command, roughly:
3806 * ctx->pipe->cmds = new struct command;
3807 * ctx->command = &ctx->pipe->cmds[0];
3810 //debug_print_tree(ctx->list_head, 10);
3812 debug_printf_parse("done_pipe return\n");
3815 static void initialize_context(struct parse_context *ctx)
3817 memset(ctx, 0, sizeof(*ctx));
3818 ctx->pipe = ctx->list_head = new_pipe();
3819 /* Create the memory for command, roughly:
3820 * ctx->pipe->cmds = new struct command;
3821 * ctx->command = &ctx->pipe->cmds[0];
3826 /* If a reserved word is found and processed, parse context is modified
3827 * and 1 is returned.
3830 struct reserved_combo {
3833 unsigned char assignment_flag;
3837 FLAG_END = (1 << RES_NONE ),
3839 FLAG_IF = (1 << RES_IF ),
3840 FLAG_THEN = (1 << RES_THEN ),
3841 FLAG_ELIF = (1 << RES_ELIF ),
3842 FLAG_ELSE = (1 << RES_ELSE ),
3843 FLAG_FI = (1 << RES_FI ),
3845 #if ENABLE_HUSH_LOOPS
3846 FLAG_FOR = (1 << RES_FOR ),
3847 FLAG_WHILE = (1 << RES_WHILE),
3848 FLAG_UNTIL = (1 << RES_UNTIL),
3849 FLAG_DO = (1 << RES_DO ),
3850 FLAG_DONE = (1 << RES_DONE ),
3851 FLAG_IN = (1 << RES_IN ),
3853 #if ENABLE_HUSH_CASE
3854 FLAG_MATCH = (1 << RES_MATCH),
3855 FLAG_ESAC = (1 << RES_ESAC ),
3857 FLAG_START = (1 << RES_XXXX ),
3860 static const struct reserved_combo* match_reserved_word(o_string *word)
3862 /* Mostly a list of accepted follow-up reserved words.
3863 * FLAG_END means we are done with the sequence, and are ready
3864 * to turn the compound list into a command.
3865 * FLAG_START means the word must start a new compound list.
3867 static const struct reserved_combo reserved_list[] = {
3869 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3870 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3871 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3872 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3873 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3874 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3876 #if ENABLE_HUSH_LOOPS
3877 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3878 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3879 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3880 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3881 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3882 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3884 #if ENABLE_HUSH_CASE
3885 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3886 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3889 const struct reserved_combo *r;
3891 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3892 if (strcmp(word->data, r->literal) == 0)
3897 static int reserved_word(o_string *word, struct parse_context *ctx)
3899 #if ENABLE_HUSH_CASE
3900 static const struct reserved_combo reserved_match = {
3901 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3904 const struct reserved_combo *r;
3906 r = match_reserved_word(word);
3910 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3911 #if ENABLE_HUSH_CASE
3912 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3913 /* "case word IN ..." - IN part starts first match part */
3914 r = &reserved_match;
3917 if (r->flag == 0) { /* '!' */
3918 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3919 syntax_error("! ! command");
3920 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3922 ctx->ctx_inverted = 1;
3925 if (r->flag & FLAG_START) {
3926 struct parse_context *old;
3927 old = xmalloc(sizeof(*old));
3928 debug_printf_parse("push stack %p\n", old);
3929 *old = *ctx; /* physical copy */
3930 initialize_context(ctx);
3932 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3933 syntax_error_at(word->data);
3934 ctx->ctx_res_w = RES_SNTX;
3937 ctx->ctx_res_w = r->res;
3938 ctx->old_flag = r->flag;
3939 if (ctx->old_flag & FLAG_END) {
3940 struct parse_context *old;
3941 done_pipe(ctx, PIPE_SEQ);
3942 debug_printf_parse("pop stack %p\n", ctx->stack);
3944 old->command->group = ctx->list_head;
3945 old->command->grp_type = GRP_NORMAL;
3947 o_addstr(&old->as_string, ctx->as_string.data);
3948 o_free_unsafe(&ctx->as_string);
3949 old->command->group_as_string = xstrdup(old->as_string.data);
3950 debug_printf_parse("pop, remembering as:'%s'\n",
3951 old->command->group_as_string);
3953 *ctx = *old; /* physical copy */
3956 word->o_assignment = r->assignment_flag;
3961 /* Word is complete, look at it and update parsing context.
3962 * Normal return is 0. Syntax errors return 1.
3963 * Note: on return, word is reset, but not o_free'd!
3965 static int done_word(o_string *word, struct parse_context *ctx)
3967 struct command *command = ctx->command;
3969 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3970 if (word->length == 0 && word->o_quoted == 0) {
3971 debug_printf_parse("done_word return 0: true null, ignored\n");
3975 if (ctx->pending_redirect) {
3976 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3977 * only if run as "bash", not "sh" */
3978 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3980 * ...the word that follows the redirection operator
3981 * shall be subjected to tilde expansion, parameter expansion,
3982 * command substitution, arithmetic expansion, and quote
3983 * removal. Pathname expansion shall not be performed
3984 * on the word by a non-interactive shell; an interactive
3985 * shell may perform it, but shall do so only when
3986 * the expansion would result in one word."
3988 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3989 /* Cater for >\file case:
3990 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3991 * Same with heredocs:
3992 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3994 unbackslash(ctx->pending_redirect->rd_filename);
3995 /* Is it <<"HEREDOC"? */
3996 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3999 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4001 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4003 /* If this word wasn't an assignment, next ones definitely
4004 * can't be assignments. Even if they look like ones. */
4005 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4006 && word->o_assignment != WORD_IS_KEYWORD
4008 word->o_assignment = NOT_ASSIGNMENT;
4010 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4011 command->assignment_cnt++;
4012 word->o_assignment = MAYBE_ASSIGNMENT;
4015 if (command->group) {
4016 /* "{ echo foo; } echo bar" - bad */
4017 /* NB: bash allows e.g.:
4018 * if true; then { echo foo; } fi
4019 * while if false; then false; fi do break; done
4021 * while if false; then false; fi; do; break; done
4023 syntax_error_at(word->data);
4024 debug_printf_parse("done_word return 1: syntax error, "
4025 "groups and arglists don't mix\n");
4029 # if ENABLE_HUSH_CASE
4030 if (ctx->ctx_dsemicolon
4031 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4033 /* already done when ctx_dsemicolon was set to 1: */
4034 /* ctx->ctx_res_w = RES_MATCH; */
4035 ctx->ctx_dsemicolon = 0;
4038 if (!command->argv /* if it's the first word... */
4039 # if ENABLE_HUSH_LOOPS
4040 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4041 && ctx->ctx_res_w != RES_IN
4044 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
4045 if (reserved_word(word, ctx)) {
4047 debug_printf_parse("done_word return %d\n",
4048 (ctx->ctx_res_w == RES_SNTX));
4049 return (ctx->ctx_res_w == RES_SNTX);
4053 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4054 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4055 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4056 /* (otherwise it's known to be not empty and is already safe) */
4058 /* exclude "$@" - it can expand to no word despite "" */
4059 char *p = word->data;
4060 while (p[0] == SPECIAL_VAR_SYMBOL
4061 && (p[1] & 0x7f) == '@'
4062 && p[2] == SPECIAL_VAR_SYMBOL
4066 if (p == word->data || p[0] != '\0') {
4067 /* saw no "$@", or not only "$@" but some
4068 * real text is there too */
4069 /* insert "empty variable" reference, this makes
4070 * e.g. "", $empty"" etc to not disappear */
4071 o_addchr(word, SPECIAL_VAR_SYMBOL);
4072 o_addchr(word, SPECIAL_VAR_SYMBOL);
4075 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4076 debug_print_strings("word appended to argv", command->argv);
4080 ctx->pending_redirect = NULL;
4082 #if ENABLE_HUSH_LOOPS
4083 /* Force FOR to have just one word (variable name) */
4084 /* NB: basically, this makes hush see "for v in ..." syntax as if
4085 * as it is "for v; in ...". FOR and IN become two pipe structs
4087 if (ctx->ctx_res_w == RES_FOR) {
4088 if (!is_well_formed_var_name(command->argv[0], '\0')) {
4089 syntax_error("malformed variable name in for");
4092 done_pipe(ctx, PIPE_SEQ);
4095 #if ENABLE_HUSH_CASE
4096 /* Force CASE to have just one word */
4097 if (ctx->ctx_res_w == RES_CASE) {
4098 done_pipe(ctx, PIPE_SEQ);
4101 debug_printf_parse("done_word return 0\n");
4106 /* Peek ahead in the input to find out if we have a "&n" construct,
4107 * as in "2>&1", that represents duplicating a file descriptor.
4109 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4110 * REDIRFD_SYNTAX_ERR if syntax error,
4111 * REDIRFD_TO_FILE if no & was seen,
4112 * or the number found.
4115 #define parse_redir_right_fd(as_string, input) \
4116 parse_redir_right_fd(input)
4118 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4124 return REDIRFD_TO_FILE;
4126 ch = i_getch(input); /* get the & */
4127 nommu_addchr(as_string, ch);
4130 ch = i_getch(input);
4131 nommu_addchr(as_string, ch);
4132 return REDIRFD_CLOSE;
4136 while (ch != EOF && isdigit(ch)) {
4137 d = d*10 + (ch-'0');
4139 ch = i_getch(input);
4140 nommu_addchr(as_string, ch);
4145 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4147 bb_error_msg("ambiguous redirect");
4148 return REDIRFD_SYNTAX_ERR;
4151 /* Return code is 0 normal, 1 if a syntax error is detected
4153 static int parse_redirect(struct parse_context *ctx,
4156 struct in_str *input)
4158 struct command *command = ctx->command;
4159 struct redir_struct *redir;
4160 struct redir_struct **redirp;
4163 dup_num = REDIRFD_TO_FILE;
4164 if (style != REDIRECT_HEREDOC) {
4165 /* Check for a '>&1' type redirect */
4166 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4167 if (dup_num == REDIRFD_SYNTAX_ERR)
4170 int ch = i_peek(input);
4171 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4172 if (dup_num) { /* <<-... */
4173 ch = i_getch(input);
4174 nommu_addchr(&ctx->as_string, ch);
4179 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4180 int ch = i_peek(input);
4182 /* >|FILE redirect ("clobbering" >).
4183 * Since we do not support "set -o noclobber" yet,
4184 * >| and > are the same for now. Just eat |.
4186 ch = i_getch(input);
4187 nommu_addchr(&ctx->as_string, ch);
4191 /* Create a new redir_struct and append it to the linked list */
4192 redirp = &command->redirects;
4193 while ((redir = *redirp) != NULL) {
4194 redirp = &(redir->next);
4196 *redirp = redir = xzalloc(sizeof(*redir));
4197 /* redir->next = NULL; */
4198 /* redir->rd_filename = NULL; */
4199 redir->rd_type = style;
4200 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4202 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4203 redir_table[style].descrip);
4205 redir->rd_dup = dup_num;
4206 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4207 /* Erik had a check here that the file descriptor in question
4208 * is legit; I postpone that to "run time"
4209 * A "-" representation of "close me" shows up as a -3 here */
4210 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4211 redir->rd_fd, redir->rd_dup);
4213 /* Set ctx->pending_redirect, so we know what to do at the
4214 * end of the next parsed word. */
4215 ctx->pending_redirect = redir;
4220 /* If a redirect is immediately preceded by a number, that number is
4221 * supposed to tell which file descriptor to redirect. This routine
4222 * looks for such preceding numbers. In an ideal world this routine
4223 * needs to handle all the following classes of redirects...
4224 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4225 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4226 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4227 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4229 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4231 * ... If n is quoted, the number shall not be recognized as part of
4232 * the redirection expression. For example:
4234 * writes the character 2 into file a"
4235 * We are getting it right by setting ->o_quoted on any \<char>
4237 * A -1 return means no valid number was found,
4238 * the caller should use the appropriate default for this redirection.
4240 static int redirect_opt_num(o_string *o)
4244 if (o->data == NULL)
4246 num = bb_strtou(o->data, NULL, 10);
4247 if (errno || num < 0)
4254 #define fetch_till_str(as_string, input, word, skip_tabs) \
4255 fetch_till_str(input, word, skip_tabs)
4257 static char *fetch_till_str(o_string *as_string,
4258 struct in_str *input,
4262 o_string heredoc = NULL_O_STRING;
4268 ch = i_getch(input);
4269 nommu_addchr(as_string, ch);
4271 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4272 heredoc.data[past_EOL] = '\0';
4273 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4274 return heredoc.data;
4277 o_addchr(&heredoc, ch);
4278 past_EOL = heredoc.length;
4281 ch = i_getch(input);
4282 nommu_addchr(as_string, ch);
4283 } while (skip_tabs && ch == '\t');
4284 } while (ch == '\n');
4287 o_free_unsafe(&heredoc);
4290 o_addchr(&heredoc, ch);
4291 nommu_addchr(as_string, ch);
4295 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4296 * and load them all. There should be exactly heredoc_cnt of them.
4298 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4300 struct pipe *pi = ctx->list_head;
4302 while (pi && heredoc_cnt) {
4304 struct command *cmd = pi->cmds;
4306 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4308 cmd->argv ? cmd->argv[0] : "NONE");
4309 for (i = 0; i < pi->num_cmds; i++) {
4310 struct redir_struct *redir = cmd->redirects;
4312 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4313 i, cmd->argv ? cmd->argv[0] : "NONE");
4315 if (redir->rd_type == REDIRECT_HEREDOC) {
4318 redir->rd_type = REDIRECT_HEREDOC2;
4319 /* redir->dup is (ab)used to indicate <<- */
4320 p = fetch_till_str(&ctx->as_string, input,
4321 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4323 syntax_error("unexpected EOF in here document");
4326 free(redir->rd_filename);
4327 redir->rd_filename = p;
4330 redir = redir->next;
4337 /* Should be 0. If it isn't, it's a parse error */
4339 bb_error_msg_and_die("heredoc BUG 2");
4346 #define parse_stream(pstring, input, end_trigger) \
4347 parse_stream(input, end_trigger)
4349 static struct pipe *parse_stream(char **pstring,
4350 struct in_str *input,
4352 static void parse_and_run_string(const char *s);
4354 #if ENABLE_HUSH_TICK
4355 static FILE *generate_stream_from_string(const char *s)
4358 int pid, channel[2];
4361 pid = BB_MMU ? fork() : vfork();
4363 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4365 if (pid == 0) { /* child */
4366 disable_restore_tty_pgrp_on_exit();
4367 /* Process substitution is not considered to be usual
4368 * 'command execution'.
4369 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4376 close(channel[0]); /* NB: close _first_, then move fd! */
4377 xmove_fd(channel[1], 1);
4378 /* Prevent it from trying to handle ctrl-z etc */
4379 USE_HUSH_JOB(G.run_list_level = 1;)
4381 reset_traps_to_defaults();
4382 parse_and_run_string(s);
4383 _exit(G.last_exitcode);
4385 /* We re-execute after vfork on NOMMU. This makes this script safe:
4386 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4387 * huge=`cat BIG` # was blocking here forever
4390 re_execute_shell(s, 0);
4395 enable_restore_tty_pgrp_on_exit();
4396 clean_up_after_re_execute();
4398 pf = fdopen(channel[0], "r");
4402 /* Return code is exit status of the process that is run. */
4403 static int process_command_subs(o_string *dest, const char *s)
4406 struct in_str pipe_str;
4409 pf = generate_stream_from_string(s);
4412 close_on_exec_on(fileno(pf));
4414 /* Now send results of command back into original context */
4415 setup_file_in_str(&pipe_str, pf);
4417 while ((ch = i_getch(&pipe_str)) != EOF) {
4423 o_addchr(dest, '\n');
4426 o_addQchr(dest, ch);
4429 debug_printf("done reading from pipe, pclose()ing\n");
4430 /* Note: we got EOF, and we just close the read end of the pipe.
4431 * We do not wait for the `cmd` child to terminate. bash and ash do.
4433 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4434 * `false`; echo $? - bash outputs "1"
4437 debug_printf("closed FILE from child. return 0\n");
4442 static int parse_group(o_string *dest, struct parse_context *ctx,
4443 struct in_str *input, int ch)
4445 /* dest contains characters seen prior to ( or {.
4446 * Typically it's empty, but for function defs,
4447 * it contains function name (without '()'). */
4448 struct pipe *pipe_list;
4450 struct command *command = ctx->command;
4452 debug_printf_parse("parse_group entered\n");
4453 #if ENABLE_HUSH_FUNCTIONS
4454 if (ch == 'F') { /* function definition? */
4455 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4456 //command->fname = dest->data;
4457 command->grp_type = GRP_FUNCTION;
4458 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4459 memset(dest, 0, sizeof(*dest));
4462 if (command->argv /* word [word](... */
4463 || dest->length /* word(... */
4464 || dest->o_quoted /* ""(... */
4467 debug_printf_parse("parse_group return 1: "
4468 "syntax error, groups and arglists don't mix\n");
4474 command->grp_type = GRP_SUBSHELL;
4478 char *as_string = NULL;
4480 pipe_list = parse_stream(&as_string, input, endch);
4483 o_addstr(&ctx->as_string, as_string);
4485 /* empty ()/{} or parse error? */
4486 if (!pipe_list || pipe_list == ERR_PTR) {
4491 debug_printf_parse("parse_group return 1: "
4492 "parse_stream returned %p\n", pipe_list);
4495 command->group = pipe_list;
4497 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4498 command->group_as_string = as_string;
4499 debug_printf_parse("end of group, remembering as:'%s'\n",
4500 command->group_as_string);
4503 debug_printf_parse("parse_group return 0\n");
4505 /* command remains "open", available for possible redirects */
4508 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4509 /* Subroutines for copying $(...) and `...` things */
4510 static int add_till_backquote(o_string *dest, struct in_str *input);
4512 static int add_till_single_quote(o_string *dest, struct in_str *input)
4515 int ch = i_getch(input);
4517 syntax_error_unterm_ch('\'');
4525 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4526 static int add_till_double_quote(o_string *dest, struct in_str *input)
4529 int ch = i_getch(input);
4531 syntax_error_unterm_ch('"');
4536 if (ch == '\\') { /* \x. Copy both chars. */
4538 ch = i_getch(input);
4542 if (add_till_backquote(dest, input))
4547 //if (ch == '$') ...
4550 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4552 * "Within the backquoted style of command substitution, backslash
4553 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4554 * The search for the matching backquote shall be satisfied by the first
4555 * backquote found without a preceding backslash; during this search,
4556 * if a non-escaped backquote is encountered within a shell comment,
4557 * a here-document, an embedded command substitution of the $(command)
4558 * form, or a quoted string, undefined results occur. A single-quoted
4559 * or double-quoted string that begins, but does not end, within the
4560 * "`...`" sequence produces undefined results."
4562 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4564 static int add_till_backquote(o_string *dest, struct in_str *input)
4567 int ch = i_getch(input);
4569 syntax_error_unterm_ch('`');
4575 /* \x. Copy both chars unless it is \` */
4576 int ch2 = i_getch(input);
4578 syntax_error_unterm_ch('`');
4581 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4588 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4589 * quoting and nested ()s.
4590 * "With the $(command) style of command substitution, all characters
4591 * following the open parenthesis to the matching closing parenthesis
4592 * constitute the command. Any valid shell script can be used for command,
4593 * except a script consisting solely of redirections which produces
4594 * unspecified results."
4596 * echo $(echo '(TEST)' BEST) (TEST) BEST
4597 * echo $(echo 'TEST)' BEST) TEST) BEST
4598 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4600 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4604 int ch = i_getch(input);
4606 syntax_error_unterm_ch(')');
4615 if (i_peek(input) == ')') {
4623 if (add_till_single_quote(dest, input))
4629 if (add_till_double_quote(dest, input))
4635 /* \x. Copy verbatim. Important for \(, \) */
4636 ch = i_getch(input);
4638 syntax_error_unterm_ch(')');
4647 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4649 /* Return code: 0 for OK, 1 for syntax error */
4651 #define handle_dollar(as_string, dest, input) \
4652 handle_dollar(dest, input)
4654 static int handle_dollar(o_string *as_string,
4656 struct in_str *input)
4659 int ch = i_peek(input); /* first character after the $ */
4660 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4662 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4664 ch = i_getch(input);
4665 nommu_addchr(as_string, ch);
4667 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4669 debug_printf_parse(": '%c'\n", ch);
4670 o_addchr(dest, ch | quote_mask);
4673 if (!isalnum(ch) && ch != '_')
4675 ch = i_getch(input);
4676 nommu_addchr(as_string, ch);
4678 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4679 } else if (isdigit(ch)) {
4681 ch = i_getch(input);
4682 nommu_addchr(as_string, ch);
4683 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4684 debug_printf_parse(": '%c'\n", ch);
4685 o_addchr(dest, ch | quote_mask);
4686 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4687 } else switch (ch) {
4689 case '!': /* last bg pid */
4690 case '?': /* last exit code */
4691 case '#': /* number of args */
4692 case '*': /* args */
4693 case '@': /* args */
4694 goto make_one_char_var;
4696 bool first_char, all_digits;
4698 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4699 ch = i_getch(input);
4700 nommu_addchr(as_string, ch);
4701 /* XXX maybe someone will try to escape the '}' */
4706 ch = i_getch(input);
4707 nommu_addchr(as_string, ch);
4713 /* ${#var}: length of var contents */
4715 else if (isdigit(ch)) {
4722 && ( (all_digits && !isdigit(ch))
4723 || (!all_digits && !isalnum(ch) && ch != '_')
4726 /* handle parameter expansions
4727 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4732 case ':': /* null modifier */
4733 if (expansion == 0) {
4734 debug_printf_parse(": null modifier\n");
4739 case '#': /* remove prefix */
4740 case '%': /* remove suffix */
4741 if (expansion == 0) {
4742 debug_printf_parse(": remove suffix/prefix\n");
4747 case '-': /* default value */
4748 case '=': /* assign default */
4749 case '+': /* alternative */
4750 case '?': /* error indicate */
4751 debug_printf_parse(": parameter expansion\n");
4756 syntax_error_unterm_str("${name}");
4757 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4762 debug_printf_parse(": '%c'\n", ch);
4763 o_addchr(dest, ch | quote_mask);
4767 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4770 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4775 ch = i_getch(input);
4776 nommu_addchr(as_string, ch);
4777 # if ENABLE_SH_MATH_SUPPORT
4778 if (i_peek(input) == '(') {
4779 ch = i_getch(input);
4780 nommu_addchr(as_string, ch);
4781 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4782 o_addchr(dest, /*quote_mask |*/ '+');
4786 if (add_till_closing_paren(dest, input, true))
4790 o_addstr(as_string, dest->data + pos);
4791 o_addchr(as_string, ')');
4792 o_addchr(as_string, ')');
4795 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4799 # if ENABLE_HUSH_TICK
4800 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4801 o_addchr(dest, quote_mask | '`');
4805 if (add_till_closing_paren(dest, input, false))
4809 o_addstr(as_string, dest->data + pos);
4810 o_addchr(as_string, '`');
4813 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4819 ch = i_getch(input);
4820 nommu_addchr(as_string, ch);
4822 if (isalnum(ch)) { /* it's $_name or $_123 */
4828 /* $_ Shell or shell script name; or last cmd name */
4829 /* $- Option flags set by set builtin or shell options (-i etc) */
4831 o_addQchr(dest, '$');
4833 debug_printf_parse("handle_dollar return 0\n");
4838 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4839 parse_stream_dquoted(dest, input, dquote_end)
4841 static int parse_stream_dquoted(o_string *as_string,
4843 struct in_str *input,
4850 ch = i_getch(input);
4852 nommu_addchr(as_string, ch);
4853 if (ch == dquote_end) { /* may be only '"' or EOF */
4854 if (dest->o_assignment == NOT_ASSIGNMENT)
4855 dest->o_escape ^= 1;
4856 debug_printf_parse("parse_stream_dquoted return 0\n");
4859 /* note: can't move it above ch == dquote_end check! */
4861 syntax_error_unterm_ch('"');
4862 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4867 next = i_peek(input);
4869 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4870 ch, ch, dest->o_escape);
4872 //TODO: check interactive behavior
4874 syntax_error("\\<eof>");
4875 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4879 * "The backslash retains its special meaning [in "..."]
4880 * only when followed by one of the following characters:
4881 * $, `, ", \, or <newline>. A double quote may be quoted
4882 * within double quotes by preceding it with a backslash.
4884 if (strchr("$`\"\\", next) != NULL) {
4885 o_addqchr(dest, i_getch(input));
4887 o_addqchr(dest, '\\');
4892 if (handle_dollar(as_string, dest, input) != 0) {
4893 debug_printf_parse("parse_stream_dquoted return 1: "
4894 "handle_dollar returned non-0\n");
4899 #if ENABLE_HUSH_TICK
4901 //int pos = dest->length;
4902 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4903 o_addchr(dest, 0x80 | '`');
4904 if (add_till_backquote(dest, input))
4906 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4907 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4911 o_addQchr(dest, ch);
4913 && (dest->o_assignment == MAYBE_ASSIGNMENT
4914 || dest->o_assignment == WORD_IS_KEYWORD)
4915 && is_well_formed_var_name(dest->data, '=')
4917 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4923 * Scan input until EOF or end_trigger char.
4924 * Return a list of pipes to execute, or NULL on EOF
4925 * or if end_trigger character is met.
4926 * On syntax error, exit is shell is not interactive,
4927 * reset parsing machinery and start parsing anew,
4928 * or return ERR_PTR.
4930 static struct pipe *parse_stream(char **pstring,
4931 struct in_str *input,
4934 struct parse_context ctx;
4935 o_string dest = NULL_O_STRING;
4939 /* Double-quote state is handled in the state variable is_in_dquote.
4940 * A single-quote triggers a bypass of the main loop until its mate is
4941 * found. When recursing, quote state is passed in via dest->o_escape.
4943 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4944 end_trigger ? : 'X');
4946 G.ifs = get_local_var_value("IFS");
4951 #if ENABLE_HUSH_INTERACTIVE
4952 input->promptmode = 0; /* PS1 */
4954 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4955 initialize_context(&ctx);
4960 const char *is_special;
4964 redir_type redir_style;
4967 /* dest.o_quoted = 1; - already is (see below) */
4968 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4971 /* We reached closing '"' */
4974 ch = i_getch(input);
4975 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4976 ch, ch, dest.o_escape);
4981 syntax_error_unterm_str("here document");
4984 if (done_word(&dest, &ctx)) {
4988 done_pipe(&ctx, PIPE_SEQ);
4990 /* If we got nothing... */
4991 // TODO: test script consisting of just "&"
4992 if (pi->num_cmds == 0
4993 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4995 free_pipe_list(pi, 0);
4998 debug_printf_parse("parse_stream return %p\n", pi);
5000 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5002 *pstring = ctx.as_string.data;
5004 o_free_unsafe(&ctx.as_string);
5008 nommu_addchr(&ctx.as_string, ch);
5009 is_ifs = strchr(G.ifs, ch);
5010 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5011 "\\$\"" USE_HUSH_TICK("`") /* always special */
5014 if (!is_special && !is_ifs) { /* ordinary char */
5015 o_addQchr(&dest, ch);
5016 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5017 || dest.o_assignment == WORD_IS_KEYWORD)
5019 && is_well_formed_var_name(dest.data, '=')
5021 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5027 if (done_word(&dest, &ctx)) {
5031 #if ENABLE_HUSH_CASE
5032 /* "case ... in <newline> word) ..." -
5033 * newlines are ignored (but ';' wouldn't be) */
5034 if (ctx.command->argv == NULL
5035 && ctx.ctx_res_w == RES_MATCH
5040 /* Treat newline as a command separator. */
5041 done_pipe(&ctx, PIPE_SEQ);
5042 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5044 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5049 dest.o_assignment = MAYBE_ASSIGNMENT;
5051 /* note: if (is_ifs) continue;
5052 * will still trigger for us */
5055 if (end_trigger && end_trigger == ch
5056 && (heredoc_cnt == 0 || end_trigger != ';')
5058 //TODO: disallow "{ cmd }" without semicolon
5060 /* This is technically valid:
5061 * { cat <<HERE; }; echo Ok
5066 * but we don't support this.
5067 * We require heredoc to be in enclosing {}/(),
5070 syntax_error_unterm_str("here document");
5073 if (done_word(&dest, &ctx)) {
5076 done_pipe(&ctx, PIPE_SEQ);
5077 dest.o_assignment = MAYBE_ASSIGNMENT;
5078 /* Do we sit outside of any if's, loops or case's? */
5080 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5082 debug_printf_parse("parse_stream return %p: "
5083 "end_trigger char found\n",
5087 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5089 *pstring = ctx.as_string.data;
5091 o_free_unsafe(&ctx.as_string);
5093 return ctx.list_head;
5101 next = i_peek(input);
5104 /* Catch <, > before deciding whether this word is
5105 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5108 redir_fd = redirect_opt_num(&dest);
5109 if (done_word(&dest, &ctx)) {
5112 redir_style = REDIRECT_OVERWRITE;
5114 redir_style = REDIRECT_APPEND;
5115 ch = i_getch(input);
5116 nommu_addchr(&ctx.as_string, ch);
5119 else if (next == '(') {
5120 syntax_error(">(process) not supported");
5124 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5126 continue; /* back to top of while (1) */
5128 redir_fd = redirect_opt_num(&dest);
5129 if (done_word(&dest, &ctx)) {
5132 redir_style = REDIRECT_INPUT;
5134 redir_style = REDIRECT_HEREDOC;
5136 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5137 ch = i_getch(input);
5138 nommu_addchr(&ctx.as_string, ch);
5139 } else if (next == '>') {
5140 redir_style = REDIRECT_IO;
5141 ch = i_getch(input);
5142 nommu_addchr(&ctx.as_string, ch);
5145 else if (next == '(') {
5146 syntax_error("<(process) not supported");
5150 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5152 continue; /* back to top of while (1) */
5155 if (dest.o_assignment == MAYBE_ASSIGNMENT
5156 /* check that we are not in word in "a=1 2>word b=1": */
5157 && !ctx.pending_redirect
5159 /* ch is a special char and thus this word
5160 * cannot be an assignment */
5161 dest.o_assignment = NOT_ASSIGNMENT;
5166 if (dest.length == 0) {
5169 if (ch == EOF || ch == '\n')
5172 /* note: we do not add it to &ctx.as_string */
5174 nommu_addchr(&ctx.as_string, '\n');
5176 o_addQchr(&dest, ch);
5181 syntax_error("\\<eof>");
5184 o_addchr(&dest, '\\');
5185 ch = i_getch(input);
5186 nommu_addchr(&ctx.as_string, ch);
5187 o_addchr(&dest, ch);
5188 /* Example: echo Hello \2>file
5189 * we need to know that word 2 is quoted */
5193 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5194 debug_printf_parse("parse_stream parse error: "
5195 "handle_dollar returned non-0\n");
5202 ch = i_getch(input);
5204 syntax_error_unterm_ch('\'');
5207 nommu_addchr(&ctx.as_string, ch);
5210 if (dest.o_assignment == NOT_ASSIGNMENT)
5211 o_addqchr(&dest, ch);
5213 o_addchr(&dest, ch);
5218 is_in_dquote ^= 1; /* invert */
5219 if (dest.o_assignment == NOT_ASSIGNMENT)
5222 #if ENABLE_HUSH_TICK
5227 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5228 o_addchr(&dest, '`');
5232 if (add_till_backquote(&dest, input))
5235 o_addstr(&ctx.as_string, dest.data + pos);
5236 o_addchr(&ctx.as_string, '`');
5238 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5239 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5244 #if ENABLE_HUSH_CASE
5247 if (done_word(&dest, &ctx)) {
5250 done_pipe(&ctx, PIPE_SEQ);
5251 #if ENABLE_HUSH_CASE
5252 /* Eat multiple semicolons, detect
5253 * whether it means something special */
5258 ch = i_getch(input);
5259 nommu_addchr(&ctx.as_string, ch);
5260 if (ctx.ctx_res_w == RES_CASEI) {
5261 ctx.ctx_dsemicolon = 1;
5262 ctx.ctx_res_w = RES_MATCH;
5268 /* We just finished a cmd. New one may start
5269 * with an assignment */
5270 dest.o_assignment = MAYBE_ASSIGNMENT;
5273 if (done_word(&dest, &ctx)) {
5277 ch = i_getch(input);
5278 nommu_addchr(&ctx.as_string, ch);
5279 done_pipe(&ctx, PIPE_AND);
5281 done_pipe(&ctx, PIPE_BG);
5285 if (done_word(&dest, &ctx)) {
5288 #if ENABLE_HUSH_CASE
5289 if (ctx.ctx_res_w == RES_MATCH)
5290 break; /* we are in case's "word | word)" */
5292 if (next == '|') { /* || */
5293 ch = i_getch(input);
5294 nommu_addchr(&ctx.as_string, ch);
5295 done_pipe(&ctx, PIPE_OR);
5297 /* we could pick up a file descriptor choice here
5298 * with redirect_opt_num(), but bash doesn't do it.
5299 * "echo foo 2| cat" yields "foo 2". */
5304 #if ENABLE_HUSH_CASE
5305 /* "case... in [(]word)..." - skip '(' */
5306 if (ctx.ctx_res_w == RES_MATCH
5307 && ctx.command->argv == NULL /* not (word|(... */
5308 && dest.length == 0 /* not word(... */
5309 && dest.o_quoted == 0 /* not ""(... */
5314 #if ENABLE_HUSH_FUNCTIONS
5315 if (dest.length != 0 /* not just () but word() */
5316 && dest.o_quoted == 0 /* not a"b"c() */
5317 && ctx.command->argv == NULL /* it's the first word */
5318 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5319 && i_peek(input) == ')'
5320 && !match_reserved_word(&dest)
5322 bb_error_msg("seems like a function definition");
5324 //if !BB_MMU o_addchr(&ctx.as_string...
5326 //TODO: do it properly.
5327 ch = i_getch(input);
5328 } while (ch == ' ' || ch == '\n');
5330 syntax_error("was expecting {");
5333 ch = 'F'; /* magic value */
5337 if (parse_group(&dest, &ctx, input, ch) != 0) {
5342 #if ENABLE_HUSH_CASE
5343 if (ctx.ctx_res_w == RES_MATCH)
5347 /* proper use of this character is caught by end_trigger:
5348 * if we see {, we call parse_group(..., end_trigger='}')
5349 * and it will match } earlier (not here). */
5350 syntax_error("unexpected } or )");
5354 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5360 struct parse_context *pctx;
5361 IF_HAS_KEYWORDS(struct parse_context *p2;)
5363 /* Clean up allocated tree.
5364 * Samples for finding leaks on syntax error recovery path.
5365 * Run them from interactive shell, watch pmap `pidof hush`.
5366 * while if false; then false; fi do break; done
5368 * while if false; then false; fi; do break; fi
5369 * Samples to catch leaks at execution:
5370 * while if (true | {true;}); then echo ok; fi; do break; done
5371 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5375 /* Update pipe/command counts,
5376 * otherwise freeing may miss some */
5377 done_pipe(pctx, PIPE_SEQ);
5378 debug_printf_clean("freeing list %p from ctx %p\n",
5379 pctx->list_head, pctx);
5380 debug_print_tree(pctx->list_head, 0);
5381 free_pipe_list(pctx->list_head, 0);
5382 debug_printf_clean("freed list %p\n", pctx->list_head);
5384 o_free_unsafe(&pctx->as_string);
5386 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5390 IF_HAS_KEYWORDS(pctx = p2;)
5391 } while (HAS_KEYWORDS && pctx);
5392 /* Free text, clear all dest fields */
5394 /* If we are not in top-level parse, we return,
5395 * our caller will propagate error.
5397 if (end_trigger != ';') {
5404 /* Discard cached input, force prompt */
5406 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5411 /* Executing from string: eval, sh -c '...'
5412 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5413 * end_trigger controls how often we stop parsing
5414 * NUL: parse all, execute, return
5415 * ';': parse till ';' or newline, execute, repeat till EOF
5417 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5420 struct pipe *pipe_list;
5422 pipe_list = parse_stream(NULL, inp, end_trigger);
5423 if (!pipe_list) /* EOF */
5425 debug_print_tree(pipe_list, 0);
5426 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5427 run_and_free_list(pipe_list);
5431 static void parse_and_run_string(const char *s)
5433 struct in_str input;
5434 setup_string_in_str(&input, s);
5435 parse_and_run_stream(&input, '\0');
5438 static void parse_and_run_file(FILE *f)
5440 struct in_str input;
5441 setup_file_in_str(&input, f);
5442 parse_and_run_stream(&input, ';');
5445 /* Called a few times only (or even once if "sh -c") */
5446 static void block_signals(int second_time)
5451 mask = (1 << SIGQUIT);
5452 if (G_interactive_fd) {
5456 //TODO | (1 << SIGHUP)
5458 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5463 G.non_DFL_mask = mask;
5466 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5470 sigaddset(&G.blocked_set, sig);
5474 sigdelset(&G.blocked_set, SIGCHLD);
5476 sigprocmask(SIG_SETMASK, &G.blocked_set,
5477 second_time ? NULL : &G.inherited_set);
5478 /* POSIX allows shell to re-enable SIGCHLD
5479 * even if it was SIG_IGN on entry */
5480 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5482 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5487 static void maybe_set_to_sigexit(int sig)
5489 void (*handler)(int);
5490 /* non_DFL_mask'ed signals are, well, masked,
5491 * no need to set handler for them.
5493 if (!((G.non_DFL_mask >> sig) & 1)) {
5494 handler = signal(sig, sigexit);
5495 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5496 signal(sig, handler);
5499 /* Set handlers to restore tty pgrp and exit */
5500 static void set_fatal_handlers(void)
5502 /* We _must_ restore tty pgrp on fatal signals */
5504 maybe_set_to_sigexit(SIGILL );
5505 maybe_set_to_sigexit(SIGFPE );
5506 maybe_set_to_sigexit(SIGBUS );
5507 maybe_set_to_sigexit(SIGSEGV);
5508 maybe_set_to_sigexit(SIGTRAP);
5509 } /* else: hush is perfect. what SEGV? */
5510 maybe_set_to_sigexit(SIGABRT);
5511 /* bash 3.2 seems to handle these just like 'fatal' ones */
5512 maybe_set_to_sigexit(SIGPIPE);
5513 maybe_set_to_sigexit(SIGALRM);
5514 //TODO: disable and move down when proper SIGHUP handling is added
5515 maybe_set_to_sigexit(SIGHUP );
5516 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5517 * if we aren't interactive... but in this case
5518 * we never want to restore pgrp on exit, and this fn is not called */
5519 /*maybe_set_to_sigexit(SIGTERM);*/
5520 /*maybe_set_to_sigexit(SIGINT );*/
5524 static int set_mode(const char cstate, const char mode)
5526 int state = (cstate == '-' ? 1 : 0);
5528 case 'n': G.fake_mode = state; break;
5529 case 'x': /*G.debug_mode = state;*/ break;
5530 default: return EXIT_FAILURE;
5532 return EXIT_SUCCESS;
5535 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5536 int hush_main(int argc, char **argv)
5538 static const struct variable const_shell_ver = {
5540 .varstr = (char*)hush_version_str,
5541 .max_len = 1, /* 0 can provoke free(name) */
5545 int signal_mask_is_inited = 0;
5548 struct variable *cur_var;
5551 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5552 G.last_exitcode = EXIT_SUCCESS;
5554 G.argv0_for_re_execing = argv[0];
5556 /* Deal with HUSH_VERSION */
5557 G.shell_ver = const_shell_ver; /* copying struct here */
5558 G.top_var = &G.shell_ver;
5559 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5560 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5561 /* Initialize our shell local variables with the values
5562 * currently living in the environment */
5563 cur_var = G.top_var;
5566 char *value = strchr(*e, '=');
5567 if (value) { /* paranoia */
5568 cur_var->next = xzalloc(sizeof(*cur_var));
5569 cur_var = cur_var->next;
5570 cur_var->varstr = *e;
5571 cur_var->max_len = strlen(*e);
5572 cur_var->flg_export = 1;
5576 debug_printf_env("putenv '%s'\n", hush_version_str);
5577 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5578 #if ENABLE_FEATURE_EDITING
5579 G.line_input_state = new_line_input_t(FOR_SHELL);
5581 G.global_argc = argc;
5582 G.global_argv = argv;
5583 /* Initialize some more globals to non-zero values */
5585 #if ENABLE_HUSH_INTERACTIVE
5586 if (ENABLE_FEATURE_EDITING)
5587 cmdedit_set_initial_prompt();
5591 if (setjmp(die_jmp)) {
5592 /* xfunc has failed! die die die */
5593 /* no EXIT traps, this is an escape hatch! */
5595 hush_exit(xfunc_error_retval);
5598 /* Shell is non-interactive at first. We need to call
5599 * block_signals(0) if we are going to execute "sh <script>",
5600 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5601 * If we later decide that we are interactive, we run block_signals(0)
5602 * (or re-run block_signals(1) if we ran block_signals(0) before)
5603 * in order to intercept (more) signals.
5607 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5609 opt = getopt(argc, argv, "c:xins"
5619 G.root_pid = getpid();
5620 G.global_argv = argv + optind;
5621 if (!argv[optind]) {
5622 /* -c 'script' (no params): prevent empty $0 */
5623 *--G.global_argv = argv[0];
5625 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5626 G.global_argc = argc - optind;
5627 block_signals(0); /* 0: called 1st time */
5628 parse_and_run_string(optarg);
5631 /* Well, we cannot just declare interactiveness,
5632 * we have to have some stuff (ctty, etc) */
5633 /* G_interactive_fd++; */
5636 /* "-s" means "read from stdin", but this is how we always
5637 * operate, so simply do nothing here. */
5640 case '<': /* "big heredoc" support */
5641 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5644 G.root_pid = bb_strtou(optarg, &optarg, 16);
5646 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5648 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5649 # if ENABLE_HUSH_LOOPS
5651 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5656 set_local_var(xstrdup(optarg), 0, opt == 'R');
5661 if (!set_mode('-', opt))
5665 fprintf(stderr, "Usage: sh [FILE]...\n"
5666 " or: sh -c command [args]...\n\n");
5672 } /* option parsing loop */
5675 G.root_pid = getpid();
5677 /* If we are login shell... */
5678 if (argv[0] && argv[0][0] == '-') {
5680 /* XXX what should argv be while sourcing /etc/profile? */
5681 debug_printf("sourcing /etc/profile\n");
5682 input = fopen_for_read("/etc/profile");
5683 if (input != NULL) {
5684 close_on_exec_on(fileno(input));
5685 block_signals(0); /* 0: called 1st time */
5686 signal_mask_is_inited = 1;
5687 parse_and_run_file(input);
5690 /* bash: after sourcing /etc/profile,
5691 * tries to source (in the given order):
5692 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5693 * stopping of first found. --noprofile turns this off.
5694 * bash also sources ~/.bash_logout on exit.
5695 * If called as sh, skips .bash_XXX files.
5702 * "bash <script>" (which is never interactive (unless -i?))
5703 * sources $BASH_ENV here (without scanning $PATH).
5704 * If called as sh, does the same but with $ENV.
5706 debug_printf("running script '%s'\n", argv[optind]);
5707 G.global_argv = argv + optind;
5708 G.global_argc = argc - optind;
5709 input = xfopen_for_read(argv[optind]);
5710 close_on_exec_on(fileno(input));
5711 if (!signal_mask_is_inited)
5712 block_signals(0); /* 0: called 1st time */
5713 parse_and_run_file(input);
5714 #if ENABLE_FEATURE_CLEAN_UP
5720 /* Up to here, shell was non-interactive. Now it may become one.
5721 * NB: don't forget to (re)run block_signals(0/1) as needed.
5724 /* A shell is interactive if the '-i' flag was given, or if all of
5725 * the following conditions are met:
5727 * no arguments remaining or the -s flag given
5728 * standard input is a terminal
5729 * standard output is a terminal
5730 * Refer to Posix.2, the description of the 'sh' utility.
5733 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5734 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5735 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5736 //TODO: "interactive" and "have job control" are two different things.
5737 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5738 //should stay on! Currently, we mix these into one.
5739 if (G.saved_tty_pgrp >= 0) {
5740 /* try to dup stdin to high fd#, >= 255 */
5741 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5742 if (G_interactive_fd < 0) {
5743 /* try to dup to any fd */
5744 G_interactive_fd = dup(STDIN_FILENO);
5745 if (G_interactive_fd < 0)
5747 G_interactive_fd = 0;
5749 // TODO: track & disallow any attempts of user
5750 // to (inadvertently) close/redirect it
5753 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5754 if (G_interactive_fd) {
5757 /* We are indeed interactive shell, and we will perform
5758 * job control. Setting up for that. */
5760 close_on_exec_on(G_interactive_fd);
5761 /* If we were run as 'hush &', sleep until we are
5762 * in the foreground (tty pgrp == our pgrp).
5763 * If we get started under a job aware app (like bash),
5764 * make sure we are now in charge so we don't fight over
5765 * who gets the foreground */
5767 shell_pgrp = getpgrp();
5768 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5769 if (G.saved_tty_pgrp == shell_pgrp)
5771 /* send TTIN to ourself (should stop us) */
5772 kill(- shell_pgrp, SIGTTIN);
5774 /* Block some signals */
5775 block_signals(signal_mask_is_inited);
5776 /* Set other signals to restore saved_tty_pgrp */
5777 set_fatal_handlers();
5778 /* Put ourselves in our own process group */
5779 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5780 /* Grab control of the terminal */
5781 tcsetpgrp(G_interactive_fd, getpid());
5782 /* -1 is special - makes xfuncs longjmp, not exit
5783 * (we reset die_sleep = 0 whereever we [v]fork) */
5784 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5785 } else if (!signal_mask_is_inited) {
5786 block_signals(0); /* 0: called 1st time */
5787 } /* else: block_signals(0) was done before */
5788 #elif ENABLE_HUSH_INTERACTIVE
5789 /* No job control compiled in, only prompt/line editing */
5790 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5791 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5792 if (G_interactive_fd < 0) {
5793 /* try to dup to any fd */
5794 G_interactive_fd = dup(STDIN_FILENO);
5795 if (G_interactive_fd < 0)
5797 G_interactive_fd = 0;
5800 if (G_interactive_fd) {
5801 close_on_exec_on(G_interactive_fd);
5802 block_signals(signal_mask_is_inited);
5803 } else if (!signal_mask_is_inited) {
5807 /* We have interactiveness code disabled */
5808 if (!signal_mask_is_inited) {
5813 * if interactive but not a login shell, sources ~/.bashrc
5814 * (--norc turns this off, --rcfile <file> overrides)
5817 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5818 printf("\n\n%s hush - the humble shell\n", bb_banner);
5819 printf("Enter 'help' for a list of built-in commands.\n\n");
5822 parse_and_run_file(stdin);
5825 #if ENABLE_FEATURE_CLEAN_UP
5826 if (G.cwd != bb_msg_unknown)
5828 cur_var = G.top_var->next;
5830 struct variable *tmp = cur_var;
5831 if (!cur_var->max_len)
5832 free(cur_var->varstr);
5833 cur_var = cur_var->next;
5837 hush_exit(G.last_exitcode);
5842 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5843 int lash_main(int argc, char **argv)
5845 //bb_error_msg("lash is deprecated, please use hush instead");
5846 return hush_main(argc, argv);
5854 static int builtin_trap(char **argv)
5861 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5865 /* No args: print all trapped. This isn't 100% correct as we
5866 * should be escaping the cmd so that it can be pasted back in
5868 for (i = 0; i < NSIG; ++i)
5870 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5871 return EXIT_SUCCESS;
5876 /* If first arg is decimal: reset all specified signals */
5877 sig = bb_strtou(*argv, NULL, 10);
5883 sig = get_signum(*argv++);
5884 if (sig < 0 || sig >= NSIG) {
5886 /* Mimic bash message exactly */
5887 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5892 G.traps[sig] = xstrdup(new_cmd);
5894 debug_printf("trap: setting SIG%s (%i) to '%s'",
5895 get_signame(sig), sig, G.traps[sig]);
5897 /* There is no signal for 0 (EXIT) */
5902 sigaddset(&G.blocked_set, sig);
5904 /* There was a trap handler, we are removing it
5905 * (if sig has non-DFL handling,
5906 * we don't need to do anything) */
5907 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5909 sigdelset(&G.blocked_set, sig);
5911 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5916 /* First arg is "-": reset all specified to default */
5917 /* First arg is "": ignore all specified */
5918 /* Everything else: execute first arg upon signal */
5920 bb_error_msg("trap: invalid arguments");
5921 return EXIT_FAILURE;
5923 if (NOT_LONE_DASH(*argv))
5929 static int builtin_true(char **argv UNUSED_PARAM)
5934 static int builtin_test(char **argv)
5941 return test_main(argc, argv - argc);
5944 static int builtin_echo(char **argv)
5951 return echo_main(argc, argv - argc);
5954 static int builtin_eval(char **argv)
5956 int rcode = EXIT_SUCCESS;
5959 char *str = expand_strvec_to_string(argv);
5961 * eval "echo Hi; done" ("done" is syntax error):
5962 * "echo Hi" will not execute too.
5964 parse_and_run_string(str);
5966 rcode = G.last_exitcode;
5971 static int builtin_cd(char **argv)
5973 const char *newdir = argv[1];
5974 if (newdir == NULL) {
5975 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5976 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5978 newdir = getenv("HOME") ? : "/";
5980 if (chdir(newdir)) {
5981 /* Mimic bash message exactly */
5982 bb_perror_msg("cd: %s", newdir);
5983 return EXIT_FAILURE;
5986 return EXIT_SUCCESS;
5989 static int builtin_exec(char **argv)
5991 if (*++argv == NULL)
5992 return EXIT_SUCCESS; /* bash does this */
5997 // FIXME: if exec fails, bash does NOT exit! We do...
5998 pseudo_exec_argv(&dummy, argv, 0, NULL);
6003 static int builtin_exit(char **argv)
6005 debug_printf_exec("%s()\n", __func__);
6006 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6007 //puts("exit"); /* bash does it */
6008 // TODO: warn if we have background jobs: "There are stopped jobs"
6009 // On second consecutive 'exit', exit anyway.
6010 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6012 /* note: EXIT trap is run by hush_exit */
6013 if (*++argv == NULL)
6014 hush_exit(G.last_exitcode);
6015 /* mimic bash: exit 123abc == exit 255 + error msg */
6016 xfunc_error_retval = 255;
6017 /* bash: exit -2 == exit 254, no error msg */
6018 hush_exit(xatoi(*argv) & 0xff);
6021 static int builtin_export(char **argv)
6023 if (*++argv == NULL) {
6025 // ash emits: export VAR='VAL'
6026 // bash: declare -x VAR="VAL"
6027 // (both also escape as needed (quotes, $, etc))
6032 return EXIT_SUCCESS;
6039 value = strchr(name, '=');
6041 /* They are exporting something without a =VALUE */
6042 struct variable *var;
6044 var = get_local_var(name);
6046 var->flg_export = 1;
6047 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6048 putenv(var->varstr);
6050 /* bash does not return an error when trying to export
6051 * an undefined variable. Do likewise. */
6054 set_local_var(xstrdup(name), 1, 0);
6057 return EXIT_SUCCESS;
6061 /* built-in 'fg' and 'bg' handler */
6062 static int builtin_fg_bg(char **argv)
6067 if (!G_interactive_fd)
6068 return EXIT_FAILURE;
6069 /* If they gave us no args, assume they want the last backgrounded task */
6071 for (pi = G.job_list; pi; pi = pi->next) {
6072 if (pi->jobid == G.last_jobid) {
6076 bb_error_msg("%s: no current job", argv[0]);
6077 return EXIT_FAILURE;
6079 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6080 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6081 return EXIT_FAILURE;
6083 for (pi = G.job_list; pi; pi = pi->next) {
6084 if (pi->jobid == jobnum) {
6088 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6089 return EXIT_FAILURE;
6091 // TODO: bash prints a string representation
6092 // of job being foregrounded (like "sleep 1 | cat")
6093 if (argv[0][0] == 'f') {
6094 /* Put the job into the foreground. */
6095 tcsetpgrp(G_interactive_fd, pi->pgrp);
6098 /* Restart the processes in the job */
6099 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6100 for (i = 0; i < pi->num_cmds; i++) {
6101 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6102 pi->cmds[i].is_stopped = 0;
6104 pi->stopped_cmds = 0;
6106 i = kill(- pi->pgrp, SIGCONT);
6108 if (errno == ESRCH) {
6109 delete_finished_bg_job(pi);
6110 return EXIT_SUCCESS;
6112 bb_perror_msg("kill (SIGCONT)");
6115 if (argv[0][0] == 'f') {
6117 return checkjobs_and_fg_shell(pi);
6119 return EXIT_SUCCESS;
6123 #if ENABLE_HUSH_HELP
6124 static int builtin_help(char **argv UNUSED_PARAM)
6126 const struct built_in_command *x;
6129 "Built-in commands:\n"
6130 "------------------\n");
6131 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6132 printf("%s\t%s\n", x->cmd, x->descr);
6135 return EXIT_SUCCESS;
6140 static int builtin_jobs(char **argv UNUSED_PARAM)
6143 const char *status_string;
6145 for (job = G.job_list; job; job = job->next) {
6146 if (job->alive_cmds == job->stopped_cmds)
6147 status_string = "Stopped";
6149 status_string = "Running";
6151 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6153 return EXIT_SUCCESS;
6158 static int builtin_memleak(char **argv UNUSED_PARAM)
6163 /* Crude attempt to find where "free memory" starts,
6164 * sans fragmentation. */
6166 l = (unsigned long)p;
6169 if (l < (unsigned long)p) l = (unsigned long)p;
6172 if (!G.memleak_value)
6173 G.memleak_value = l;
6175 l -= G.memleak_value;
6182 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6187 static int builtin_pwd(char **argv UNUSED_PARAM)
6190 return EXIT_SUCCESS;
6193 static int builtin_read(char **argv)
6196 const char *name = "REPLY";
6200 if (!is_well_formed_var_name(name, '\0')) {
6201 /* Mimic bash message */
6202 bb_error_msg("read: '%s': not a valid identifier", name);
6207 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6208 return set_local_var(string, 0, 0);
6211 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6212 * built-in 'set' handler
6214 * set [-abCefhmnuvx] [-o option] [argument...]
6215 * set [+abCefhmnuvx] [+o option] [argument...]
6216 * set -- [argument...]
6219 * Implementations shall support the options in both their hyphen and
6220 * plus-sign forms. These options can also be specified as options to sh.
6222 * Write out all variables and their values: set
6223 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6224 * Turn on the -x and -v options: set -xv
6225 * Unset all positional parameters: set --
6226 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6227 * Set the positional parameters to the expansion of x, even if x expands
6228 * with a leading '-' or '+': set -- $x
6230 * So far, we only support "set -- [argument...]" and some of the short names.
6232 static int builtin_set(char **argv)
6235 char **pp, **g_argv;
6236 char *arg = *++argv;
6240 for (e = G.top_var; e; e = e->next)
6242 return EXIT_SUCCESS;
6246 if (!strcmp(arg, "--")) {
6251 if (arg[0] == '+' || arg[0] == '-') {
6252 for (n = 1; arg[n]; ++n)
6253 if (set_mode(arg[0], arg[n]))
6259 } while ((arg = *++argv) != NULL);
6260 /* Now argv[0] is 1st argument */
6262 /* Only reset global_argv if we didn't process anything */
6264 return EXIT_SUCCESS;
6267 /* NB: G.global_argv[0] ($0) is never freed/changed */
6268 g_argv = G.global_argv;
6269 if (G.global_args_malloced) {
6275 G.global_args_malloced = 1;
6276 pp = xzalloc(sizeof(pp[0]) * 2);
6277 pp[0] = g_argv[0]; /* retain $0 */
6280 /* This realloc's G.global_argv */
6281 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6288 return EXIT_SUCCESS;
6290 /* Nothing known, so abort */
6292 bb_error_msg("set: %s: invalid option", arg);
6293 return EXIT_FAILURE;
6296 static int builtin_shift(char **argv)
6302 if (n >= 0 && n < G.global_argc) {
6303 if (G.global_args_malloced) {
6306 free(G.global_argv[m++]);
6309 memmove(&G.global_argv[1], &G.global_argv[n+1],
6310 G.global_argc * sizeof(G.global_argv[0]));
6311 return EXIT_SUCCESS;
6313 return EXIT_FAILURE;
6316 static int builtin_source(char **argv)
6320 if (*++argv == NULL)
6321 return EXIT_FAILURE;
6323 /* XXX search through $PATH is missing */
6324 input = fopen_or_warn(*argv, "r");
6326 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6327 return EXIT_FAILURE;
6329 close_on_exec_on(fileno(input));
6331 /* Now run the file */
6333 /* XXX argv and argc are broken; need to save old G.global_argv
6334 * (pointer only is OK!) on this stack frame,
6335 * set G.global_argv=argv+1, recurse, and restore. */
6336 parse_and_run_file(input);
6338 return G.last_exitcode;
6341 static int builtin_umask(char **argv)
6344 const char *arg = argv[1];
6346 //TODO: umask may take chmod-like symbolic masks
6347 new_umask = bb_strtou(arg, NULL, 8);
6349 //Message? bash examples:
6350 //bash: umask: 'q': invalid symbolic mode operator
6351 //bash: umask: 999: octal number out of range
6352 return EXIT_FAILURE;
6355 new_umask = umask(0);
6356 printf("%.3o\n", (unsigned) new_umask);
6357 /* fall through and restore new_umask which we set to 0 */
6360 return EXIT_SUCCESS;
6363 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6364 static int builtin_unset(char **argv)
6370 return EXIT_SUCCESS;
6373 if (argv[0][0] == '-') {
6374 switch (argv[0][1]) {
6380 bb_error_msg("unset: %s: invalid option", *argv);
6381 return EXIT_FAILURE;
6383 //TODO: disallow "unset -vf ..." too
6390 if (unset_local_var(*argv)) {
6391 /* unset <nonexistent_var> doesn't fail.
6392 * Error is when one tries to unset RO var.
6393 * Message was printed by unset_local_var. */
6397 #if ENABLE_HUSH_FUNCTIONS
6399 unset_local_func(*argv);
6407 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6408 static int builtin_wait(char **argv)
6410 int ret = EXIT_SUCCESS;
6413 if (*++argv == NULL) {
6414 /* Don't care about wait results */
6415 /* Note 1: must wait until there are no more children */
6416 /* Note 2: must be interruptible */
6418 * $ sleep 3 & sleep 6 & wait
6423 * $ sleep 3 & sleep 6 & wait
6427 * ^C <-- after ~4 sec from keyboard
6430 sigaddset(&G.blocked_set, SIGCHLD);
6431 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6434 if (errno == ECHILD)
6436 /* Wait for SIGCHLD or any other signal of interest */
6437 /* sigtimedwait with infinite timeout: */
6438 sig = sigwaitinfo(&G.blocked_set, NULL);
6440 sig = check_and_run_traps(sig);
6441 if (sig && sig != SIGCHLD) { /* see note 2 */
6447 sigdelset(&G.blocked_set, SIGCHLD);
6448 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6452 /* This is probably buggy wrt interruptible-ness */
6454 pid_t pid = bb_strtou(*argv, NULL, 10);
6456 /* mimic bash message */
6457 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6458 return EXIT_FAILURE;
6460 if (waitpid(pid, &status, 0) == pid) {
6461 if (WIFSIGNALED(status))
6462 ret = 128 + WTERMSIG(status);
6463 else if (WIFEXITED(status))
6464 ret = WEXITSTATUS(status);
6468 bb_perror_msg("wait %s", *argv);
6477 #if ENABLE_HUSH_LOOPS
6478 static int builtin_break(char **argv)
6480 if (G.depth_of_loop == 0) {
6481 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6482 return EXIT_SUCCESS; /* bash compat */
6484 G.flag_break_continue++; /* BC_BREAK = 1 */
6485 G.depth_break_continue = 1;
6487 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6488 if (errno || !G.depth_break_continue || argv[2]) {
6489 bb_error_msg("%s: bad arguments", argv[0]);
6490 G.flag_break_continue = BC_BREAK;
6491 G.depth_break_continue = UINT_MAX;
6494 if (G.depth_of_loop < G.depth_break_continue)
6495 G.depth_break_continue = G.depth_of_loop;
6496 return EXIT_SUCCESS;
6499 static int builtin_continue(char **argv)
6501 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6502 return builtin_break(argv);