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 */
68 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
69 //#include "applet_tables.h" doesn't work
71 /* #include <dmalloc.h> */
78 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
82 /* Debug build knobs */
83 //#define LEAK_HUNTING 1
84 //#define WANT_TO_TEST_NOMMU 1
87 #ifdef WANT_TO_TEST_NOMMU
92 # define USE_FOR_NOMMU(...) __VA_ARGS__
93 # define USE_FOR_MMU(...)
96 #if defined SINGLE_APPLET_MAIN
97 /* STANDALONE does not make sense, and won't compile */
98 #undef CONFIG_FEATURE_SH_STANDALONE
99 #undef ENABLE_FEATURE_SH_STANDALONE
100 #undef USE_FEATURE_SH_STANDALONE
101 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 #define ENABLE_FEATURE_SH_STANDALONE 0
103 #define USE_FEATURE_SH_STANDALONE(...)
104 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #if !ENABLE_HUSH_INTERACTIVE
108 #undef ENABLE_FEATURE_EDITING
109 #define ENABLE_FEATURE_EDITING 0
110 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
111 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
114 /* Do we support ANY keywords? */
115 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
116 #define HAS_KEYWORDS 1
117 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
118 #define IF_HAS_NO_KEYWORDS(...)
120 #define HAS_KEYWORDS 0
121 #define IF_HAS_KEYWORDS(...)
122 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
125 /* Enable/disable sanity checks. Ok to enable in production,
126 * only adds a bit of bloat.
127 * Keeping unconditionally on for now.
131 #define ENABLE_HUSH_FUNCTIONS 0
134 /* If you comment out one of these below, it will be #defined later
135 * to perform debug printfs to stderr: */
136 #define debug_printf(...) do {} while (0)
137 /* Finer-grained debug switches */
138 #define debug_printf_parse(...) do {} while (0)
139 #define debug_print_tree(a, b) do {} while (0)
140 #define debug_printf_exec(...) do {} while (0)
141 #define debug_printf_env(...) do {} while (0)
142 #define debug_printf_jobs(...) do {} while (0)
143 #define debug_printf_expand(...) do {} while (0)
144 #define debug_printf_glob(...) do {} while (0)
145 #define debug_printf_list(...) do {} while (0)
146 #define debug_printf_subst(...) do {} while (0)
147 #define debug_printf_clean(...) do {} while (0)
150 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
153 #ifndef debug_printf_parse
154 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
157 #ifndef debug_printf_exec
158 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
161 #ifndef debug_printf_env
162 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
165 #ifndef debug_printf_jobs
166 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
172 #ifndef debug_printf_expand
173 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
174 #define DEBUG_EXPAND 1
176 #define DEBUG_EXPAND 0
179 #ifndef debug_printf_glob
180 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
186 #ifndef debug_printf_list
187 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
190 #ifndef debug_printf_subst
191 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
194 #ifndef debug_printf_clean
195 /* broken, of course, but OK for testing */
196 static const char *indenter(int i)
198 static const char blanks[] ALIGN1 =
200 return &blanks[sizeof(blanks) - i - 1];
202 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
203 #define DEBUG_CLEAN 1
205 #define DEBUG_CLEAN 0
209 static void debug_print_strings(const char *prefix, char **vv)
211 fprintf(stderr, "%s:\n", prefix);
213 fprintf(stderr, " '%s'\n", *vv++);
216 #define debug_print_strings(prefix, vv) ((void)0)
220 * Leak hunting. Use hush_leaktool.sh for post-processing.
223 static void *xxmalloc(int lineno, size_t size)
225 void *ptr = xmalloc((size + 0xff) & ~0xff);
226 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
229 static void *xxrealloc(int lineno, void *ptr, size_t size)
231 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
232 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
235 static char *xxstrdup(int lineno, const char *str)
237 char *ptr = xstrdup(str);
238 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
241 static void xxfree(void *ptr)
243 fdprintf(2, "free %p\n", ptr);
246 #define xmalloc(s) xxmalloc(__LINE__, s)
247 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
248 #define xstrdup(s) xxstrdup(__LINE__, s)
249 #define free(p) xxfree(p)
253 #define ERR_PTR ((void*)(long)1)
255 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
257 #define SPECIAL_VAR_SYMBOL 3
259 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
261 /* This supports saving pointers malloced in vfork child,
262 * to be freed in the parent. One pointer is saved in
263 * G.argv_from_re_execing global var instead. TODO: unify.
266 typedef struct nommu_save_t {
273 /* The descrip member of this structure is only used to make
274 * debugging output pretty */
275 static const struct {
277 signed char default_fd;
281 { O_RDONLY, 0, "<" },
282 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
283 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
284 { O_RDONLY, 0, "<<" },
285 { O_CREAT|O_RDWR, 1, "<>" },
286 /* Should not be needed. Bogus default_fd helps in debugging */
287 /* { O_RDONLY, 77, "<<" }, */
290 typedef enum reserved_style {
299 #if ENABLE_HUSH_LOOPS
306 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
311 /* two pseudo-keywords support contrived "case" syntax: */
312 RES_MATCH , /* "word)" */
313 RES_CASEI , /* "this command is inside CASE" */
320 typedef struct o_string {
322 int length; /* position where data is appended */
324 /* Protect newly added chars against globbing
325 * (by prepending \ to *, ?, [, \) */
328 /* At least some part of the string was inside '' or "",
329 * possibly empty one: word"", wo''rd etc. */
331 smallint has_empty_slot;
332 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
335 MAYBE_ASSIGNMENT = 0,
336 DEFINITELY_ASSIGNMENT = 1,
338 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
340 /* Used for initialization: o_string foo = NULL_O_STRING; */
341 #define NULL_O_STRING { NULL }
343 /* I can almost use ordinary FILE*. Is open_memstream() universally
344 * available? Where is it documented? */
345 typedef struct in_str {
347 /* eof_flag=1: last char in ->p is really an EOF */
348 char eof_flag; /* meaningless if ->p == NULL */
350 #if ENABLE_HUSH_INTERACTIVE
352 smallint promptmode; /* 0: PS1, 1: PS2 */
355 int (*get) (struct in_str *);
356 int (*peek) (struct in_str *);
358 #define i_getch(input) ((input)->get(input))
359 #define i_peek(input) ((input)->peek(input))
361 struct redir_struct {
362 struct redir_struct *next;
363 char *rd_filename; /* filename */
364 int rd_fd; /* fd to redirect */
365 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
367 smallint rd_type; /* (enum redir_type) */
368 /* note: for heredocs, rd_filename contains heredoc delimiter,
369 * and subsequently heredoc itself; and rd_dup is a bitmask:
370 * 1: do we need to trim leading tabs?
371 * 2: is heredoc quoted (<<'dleim' syntax) ?
374 typedef enum redir_type {
375 REDIRECT_INVALID = 0,
377 REDIRECT_OVERWRITE = 2,
379 REDIRECT_HEREDOC = 4,
381 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
383 HEREDOC_SKIPTABS = 1,
389 pid_t pid; /* 0 if exited */
390 int assignment_cnt; /* how many argv[i] are assignments? */
391 smallint is_stopped; /* is the command currently running? */
392 smallint grp_type; /* GRP_xxx */
393 struct pipe *group; /* if non-NULL, this "command" is { list },
394 * ( list ), or a compound statement */
396 char *group_as_string;
398 char **argv; /* command name and arguments */
399 struct redir_struct *redirects; /* I/O redirections */
401 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
402 * and on execution these are substituted with their values.
403 * Substitution can make _several_ words out of one argv[n]!
404 * Example: argv[0]=='.^C*^C.' here: echo .$*.
405 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
408 #define GRP_SUBSHELL 1
409 #if ENABLE_HUSH_FUNCTIONS
410 #define GRP_FUNCTION 2
415 int num_cmds; /* total number of commands in job */
416 int alive_cmds; /* number of commands running (not exited) */
417 int stopped_cmds; /* number of commands alive, but stopped */
419 int jobid; /* job number */
420 pid_t pgrp; /* process group ID for the job */
421 char *cmdtext; /* name of job */
423 struct command *cmds; /* array of commands in pipe */
424 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
425 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
426 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
428 typedef enum pipe_style {
435 /* This holds pointers to the various results of parsing */
436 struct parse_context {
437 /* linked list of pipes */
438 struct pipe *list_head;
439 /* last pipe (being constructed right now) */
441 /* last command in pipe (being constructed right now) */
442 struct command *command;
443 /* last redirect in command->redirects list */
444 struct redir_struct *pending_redirect;
450 smallint ctx_inverted; /* "! cmd | cmd" */
452 smallint ctx_dsemicolon; /* ";;" seen */
454 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
456 /* group we are enclosed in:
457 * example: "if pipe1; pipe2; then pipe3; fi"
458 * when we see "if" or "then", we malloc and copy current context,
459 * and make ->stack point to it. then we parse pipeN.
460 * when closing "then" / fi" / whatever is found,
461 * we move list_head into ->stack->command->group,
462 * copy ->stack into current context, and delete ->stack.
463 * (parsing of { list } and ( list ) doesn't use this method)
465 struct parse_context *stack;
469 /* On program start, environ points to initial environment.
470 * putenv adds new pointers into it, unsetenv removes them.
471 * Neither of these (de)allocates the strings.
472 * setenv allocates new strings in malloc space and does putenv,
473 * and thus setenv is unusable (leaky) for shell's purposes */
474 #define setenv(...) setenv_is_leaky_dont_use()
476 struct variable *next;
477 char *varstr; /* points to "name=" portion */
478 int max_len; /* if > 0, name is part of initial env; else name is malloced */
479 smallint flg_export; /* putenv should be done on this var */
480 smallint flg_read_only;
489 /* "Globals" within this file */
490 /* Sorted roughly by size (smaller offsets == smaller code) */
492 #if ENABLE_HUSH_INTERACTIVE
493 /* 'interactive_fd' is a fd# open to ctty, if we have one
494 * _AND_ if we decided to act interactively */
498 #define G_interactive_fd (G.interactive_fd)
500 #define G_interactive_fd 0
502 #if ENABLE_FEATURE_EDITING
503 line_input_t *line_input_state;
509 pid_t saved_tty_pgrp;
511 struct pipe *job_list;
512 struct pipe *toplevel_list;
513 //// smallint ctrl_z_flag;
515 smallint flag_SIGINT;
516 #if ENABLE_HUSH_LOOPS
517 smallint flag_break_continue;
520 smallint exiting; /* used to prevent EXIT trap recursion */
521 /* These four support $?, $#, and $1 */
522 smalluint last_exitcode;
523 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
524 smalluint global_args_malloced;
525 /* how many non-NULL argv's we have. NB: $# + 1 */
529 char *argv0_for_re_execing;
530 char **argv_from_re_execing;
532 #if ENABLE_HUSH_LOOPS
533 unsigned depth_break_continue;
534 unsigned depth_of_loop;
538 struct variable *top_var; /* = &G.shell_ver (set in main()) */
539 struct variable shell_ver;
540 /* Signal and trap handling */
541 // unsigned count_SIGCHLD;
542 // unsigned handled_SIGCHLD;
543 /* which signals have non-DFL handler (even with no traps set)? */
544 unsigned non_DFL_mask;
545 char **traps; /* char *traps[NSIG] */
546 sigset_t blocked_set;
547 sigset_t inherited_set;
549 unsigned long memleak_value;
551 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
552 #if ENABLE_FEATURE_SH_STANDALONE
553 struct nofork_save_area nofork_save;
556 sigjmp_buf toplevel_jb;
559 #define G (*ptr_to_globals)
560 /* Not #defining name to G.name - this quickly gets unwieldy
561 * (too many defines). Also, I actually prefer to see when a variable
562 * is global, thus "G." prefix is a useful hint */
563 #define INIT_G() do { \
564 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
568 /* Function prototypes for builtins */
569 static int builtin_cd(char **argv);
570 static int builtin_echo(char **argv);
571 static int builtin_eval(char **argv);
572 static int builtin_exec(char **argv);
573 static int builtin_exit(char **argv);
574 static int builtin_export(char **argv);
576 static int builtin_fg_bg(char **argv);
577 static int builtin_jobs(char **argv);
580 static int builtin_help(char **argv);
583 static int builtin_memleak(char **argv);
585 static int builtin_pwd(char **argv);
586 static int builtin_read(char **argv);
587 static int builtin_set(char **argv);
588 static int builtin_shift(char **argv);
589 static int builtin_source(char **argv);
590 static int builtin_test(char **argv);
591 static int builtin_trap(char **argv);
592 static int builtin_true(char **argv);
593 static int builtin_umask(char **argv);
594 static int builtin_unset(char **argv);
595 static int builtin_wait(char **argv);
596 #if ENABLE_HUSH_LOOPS
597 static int builtin_break(char **argv);
598 static int builtin_continue(char **argv);
601 /* Table of built-in functions. They can be forked or not, depending on
602 * context: within pipes, they fork. As simple commands, they do not.
603 * When used in non-forking context, they can change global variables
604 * in the parent shell process. If forked, of course they cannot.
605 * For example, 'unset foo | whatever' will parse and run, but foo will
606 * still be set at the end. */
607 struct built_in_command {
609 int (*function)(char **argv);
612 #define BLTIN(cmd, func, help) { cmd, func, help }
614 #define BLTIN(cmd, func, help) { cmd, func }
618 /* For now, echo and test are unconditionally enabled.
619 * Maybe make it configurable? */
620 static const struct built_in_command bltins[] = {
621 BLTIN("." , builtin_source , "Run commands in a file"),
622 BLTIN(":" , builtin_true , "No-op"),
623 BLTIN("[" , builtin_test , "Test condition"),
625 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
627 #if ENABLE_HUSH_LOOPS
628 BLTIN("break" , builtin_break , "Exit from a loop"),
630 BLTIN("cd" , builtin_cd , "Change directory"),
631 #if ENABLE_HUSH_LOOPS
632 BLTIN("continue", builtin_continue, "Start new loop iteration"),
634 BLTIN("echo" , builtin_echo , "Write to stdout"),
635 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
636 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
637 BLTIN("exit" , builtin_exit , "Exit"),
638 BLTIN("export" , builtin_export , "Set environment variable"),
640 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
643 BLTIN("help" , builtin_help , "List shell built-in commands"),
646 BLTIN("jobs" , builtin_jobs , "List active jobs"),
649 BLTIN("memleak" , builtin_memleak , "Debug tool"),
651 BLTIN("pwd" , builtin_pwd , "Print current directory"),
652 BLTIN("read" , builtin_read , "Input environment variable"),
653 // BLTIN("return" , builtin_return , "Return from a function"),
654 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
655 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
656 BLTIN("test" , builtin_test , "Test condition"),
657 BLTIN("trap" , builtin_trap , "Trap signals"),
658 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
659 BLTIN("umask" , builtin_umask , "Set file creation mask"),
660 BLTIN("unset" , builtin_unset , "Unset environment variable"),
661 BLTIN("wait" , builtin_wait , "Wait for process"),
665 static void maybe_die(const char *notice, const char *msg)
667 /* Was using fancy stuff:
668 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
669 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
670 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
671 #if ENABLE_HUSH_INTERACTIVE
672 if (G_interactive_fd)
675 fp(msg ? "%s: %s" : notice, notice, msg);
678 #define syntax(msg) maybe_die("syntax error", msg);
680 /* Debug -- trick gcc to expand __LINE__ and convert to string */
681 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
682 #define _syntax(msg, line) __syntax(msg, line)
683 #define syntax(msg) _syntax(msg, __LINE__)
687 static int glob_needed(const char *s)
692 if (*s == '*' || *s == '[' || *s == '?')
699 static int is_assignment(const char *s)
701 if (!s || !(isalpha(*s) || *s == '_'))
704 while (isalnum(*s) || *s == '_')
709 /* Replace each \x with x in place, return ptr past NUL. */
710 static char *unbackslash(char *src)
716 if ((*dst++ = *src++) == '\0')
722 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
743 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
744 v[count1 + count2] = NULL;
747 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
751 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
753 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
754 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
757 #define add_strings_to_strings(strings, add, need_to_dup) \
758 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
761 static char **add_string_to_strings(char **strings, char *add)
766 return add_strings_to_strings(strings, v, /*dup:*/ 0);
769 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
771 char **ptr = add_string_to_strings(strings, add);
772 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
775 #define add_string_to_strings(strings, add) \
776 xx_add_string_to_strings(__LINE__, strings, add)
779 static void putenv_all(char **strings)
784 debug_printf_env("putenv '%s'\n", *strings);
789 static char **putenv_all_and_save_old(char **strings)
799 eq = strchr(*strings, '=');
802 v = getenv(*strings);
805 /* v points to VAL in VAR=VAL, go back to VAR */
806 v -= (eq - *strings) + 1;
807 old = add_string_to_strings(old, v);
816 static void free_strings_and_unsetenv(char **strings, int unset)
826 debug_printf_env("unsetenv '%s'\n", *v);
834 static void free_strings(char **strings)
836 free_strings_and_unsetenv(strings, 0);
840 /* Basic theory of signal handling in shell
841 * ========================================
842 * This does not describe what hush does, rather, it is current understanding
843 * what it _should_ do. If it doesn't, it's a bug.
844 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
846 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
847 * is finished or backgrounded. It is the same in interactive and
848 * non-interactive shells, and is the same regardless of whether
849 * a user trap handler is installed or a shell special one is in effect.
850 * ^C or ^Z from keyboard seem to execute "at once" because it usually
851 * backgrounds (i.e. stops) or kills all members of currently running
854 * Wait builtin in interruptible by signals for which user trap is set
855 * or by SIGINT in interactive shell.
857 * Trap handlers will execute even within trap handlers. (right?)
859 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
861 * If job control is off, backgrounded commands ("cmd &")
862 * have SIGINT, SIGQUIT set to SIG_IGN.
864 * Commands run in command substitution ("`cmd`")
865 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
867 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
868 * by the shell from its parent.
870 * Siganls which differ from SIG_DFL action
871 * (note: child (i.e., [v]forked) shell is not an interactive shell):
874 * SIGTERM (interactive): ignore
875 * SIGHUP (interactive):
876 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
877 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
878 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
879 * that all pipe members are stopped) (right?)
880 * SIGINT (interactive): wait for last pipe, ignore the rest
881 * of the command line, show prompt. NB: ^C does not send SIGINT
882 * to interactive shell while shell is waiting for a pipe,
883 * since shell is bg'ed (is not in foreground process group).
884 * (check/expand this)
885 * Example 1: this waits 5 sec, but does not execute ls:
886 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
887 * Example 2: this does not wait and does not execute ls:
888 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
889 * Example 3: this does not wait 5 sec, but executes ls:
890 * "sleep 5; ls -l" + press ^C
892 * (What happens to signals which are IGN on shell start?)
893 * (What happens with signal mask on shell start?)
895 * Implementation in hush
896 * ======================
897 * We use in-kernel pending signal mask to determine which signals were sent.
898 * We block all signals which we don't want to take action immediately,
899 * i.e. we block all signals which need to have special handling as described
900 * above, and all signals which have traps set.
901 * After each pipe execution, we extract any pending signals via sigtimedwait()
904 * unsigned non_DFL_mask: a mask of such "special" signals
905 * sigset_t blocked_set: current blocked signal set
908 * clear bit in blocked_set unless it is also in non_DFL_mask
909 * "trap 'cmd' SIGxxx":
910 * set bit in blocked_set (even if 'cmd' is '')
911 * after [v]fork, if we plan to be a shell:
912 * nothing for {} child shell (say, "true | { true; true; } | true")
913 * unset all traps if () shell.
914 * after [v]fork, if we plan to exec:
915 * POSIX says pending signal mask is cleared in child - no need to clear it.
916 * Restore blocked signal set to one inherited by shell just prior to exec.
918 * Note: as a result, we do not use signal handlers much. The only uses
919 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
920 * and to restore tty pgrp on signal-induced exit.
923 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
925 // G.count_SIGCHLD++;
928 static int check_and_run_traps(int sig)
930 static const struct timespec zero_timespec = { 0, 0 };
931 smalluint save_rcode;
937 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
942 if (G.traps && G.traps[sig]) {
943 if (G.traps[sig][0]) {
944 /* We have user-defined handler */
945 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
946 save_rcode = G.last_exitcode;
949 G.last_exitcode = save_rcode;
950 } /* else: "" trap, ignoring signal */
953 /* not a trap: special action */
956 // G.count_SIGCHLD++;
965 default: /* ignored: */
966 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
975 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
976 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
977 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
978 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
980 /* Restores tty foreground process group, and exits.
981 * May be called as signal handler for fatal signal
982 * (will faithfully resend signal to itself, producing correct exit state)
983 * or called directly with -EXITCODE.
984 * We also call it if xfunc is exiting. */
985 static void sigexit(int sig) NORETURN;
986 static void sigexit(int sig)
988 /* Disable all signals: job control, SIGPIPE, etc. */
989 sigprocmask_allsigs(SIG_BLOCK);
991 /* Careful: we can end up here after [v]fork. Do not restore
992 * tty pgrp then, only top-level shell process does that */
993 if (G_interactive_fd && getpid() == G.root_pid)
994 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
996 /* Not a signal, just exit */
1000 kill_myself_with_sig(sig); /* does not return */
1004 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1005 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1009 /* Restores tty foreground process group, and exits. */
1010 static void hush_exit(int exitcode) NORETURN;
1011 static void hush_exit(int exitcode)
1013 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1014 /* Prevent recursion:
1015 * trap "echo Hi; exit" EXIT; exit
1017 char *argv[] = { NULL, G.traps[0], NULL };
1025 fflush(NULL); /* flush all streams */
1026 sigexit(- (exitcode & 0xff));
1033 static const char *set_cwd(void)
1035 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1036 * we must not try to free(bb_msg_unknown) */
1037 if (G.cwd == bb_msg_unknown)
1039 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1041 G.cwd = bb_msg_unknown;
1046 /* Get/check local shell variables */
1047 static struct variable *get_local_var(const char *name)
1049 struct variable *cur;
1055 for (cur = G.top_var; cur; cur = cur->next) {
1056 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1062 static const char *get_local_var_value(const char *src)
1064 struct variable *var = get_local_var(src);
1066 return strchr(var->varstr, '=') + 1;
1070 /* str holds "NAME=VAL" and is expected to be malloced.
1071 * We take ownership of it.
1075 * -1: if NAME is set, leave export status alone
1076 * if NAME is not set, do not export
1077 * flg_read_only is set only when we handle -R var=val
1080 #define set_local_var(str, flg_export, flg_read_only) \
1081 set_local_var(str, flg_export)
1083 static int set_local_var(char *str, int flg_export, int flg_read_only)
1085 struct variable *cur;
1089 value = strchr(str, '=');
1090 if (!value) { /* not expected to ever happen? */
1095 name_len = value - str + 1; /* including '=' */
1096 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1098 if (strncmp(cur->varstr, str, name_len) != 0) {
1100 /* Bail out. Note that now cur points
1101 * to last var in linked list */
1107 /* We found an existing var with this name */
1109 if (cur->flg_read_only) {
1113 bb_error_msg("%s: readonly variable", str);
1117 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1118 unsetenv(str); /* just in case */
1120 if (strcmp(cur->varstr, str) == 0) {
1125 if (cur->max_len >= strlen(str)) {
1126 /* This one is from startup env, reuse space */
1127 strcpy(cur->varstr, str);
1130 /* max_len == 0 signifies "malloced" var, which we can
1131 * (and has to) free */
1135 goto set_str_and_exp;
1138 /* Not found - create next variable struct */
1139 cur->next = xzalloc(sizeof(*cur));
1145 cur->flg_read_only = flg_read_only;
1148 if (flg_export == 1)
1149 cur->flg_export = 1;
1150 if (cur->flg_export) {
1151 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1152 return putenv(cur->varstr);
1157 static int unset_local_var(const char *name)
1159 struct variable *cur;
1160 struct variable *prev = prev; /* for gcc */
1164 return EXIT_SUCCESS;
1165 name_len = strlen(name);
1168 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1169 if (cur->flg_read_only) {
1170 bb_error_msg("%s: readonly variable", name);
1171 return EXIT_FAILURE;
1173 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1174 * is ro, and we cannot reach this code on the 1st pass */
1175 prev->next = cur->next;
1176 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1177 bb_unsetenv(cur->varstr);
1181 return EXIT_SUCCESS;
1186 return EXIT_SUCCESS;
1189 #if ENABLE_SH_MATH_SUPPORT
1190 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1191 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1192 static char *endofname(const char *name)
1200 if (!is_in_name(*p))
1206 static void arith_set_local_var(const char *name, const char *val, int flags)
1208 /* arith code doesnt malloc space, so do it for it */
1209 char *var = xasprintf("%s=%s", name, val);
1210 set_local_var(var, flags, 0);
1218 static int static_get(struct in_str *i)
1227 static int static_peek(struct in_str *i)
1232 #if ENABLE_HUSH_INTERACTIVE
1234 static void cmdedit_set_initial_prompt(void)
1236 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1237 G.PS1 = getenv("PS1");
1244 static const char* setup_prompt_string(int promptmode)
1246 const char *prompt_str;
1247 debug_printf("setup_prompt_string %d ", promptmode);
1248 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1249 /* Set up the prompt */
1250 if (promptmode == 0) { /* PS1 */
1252 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1257 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1258 debug_printf("result '%s'\n", prompt_str);
1262 static void get_user_input(struct in_str *i)
1265 const char *prompt_str;
1267 prompt_str = setup_prompt_string(i->promptmode);
1268 #if ENABLE_FEATURE_EDITING
1269 /* Enable command line editing only while a command line
1270 * is actually being read */
1273 /* buglet: SIGINT will not make new prompt to appear _at once_,
1274 * only after <Enter>. (^C will work) */
1275 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1276 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1277 check_and_run_traps(0);
1278 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1279 i->eof_flag = (r < 0);
1280 if (i->eof_flag) { /* EOF/error detected */
1281 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1282 G.user_input_buf[1] = '\0';
1287 fputs(prompt_str, stdout);
1289 G.user_input_buf[0] = r = fgetc(i->file);
1290 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1291 //do we need check_and_run_traps(0)? (maybe only if stdin)
1292 } while (G.flag_SIGINT);
1293 i->eof_flag = (r == EOF);
1295 i->p = G.user_input_buf;
1298 #endif /* INTERACTIVE */
1300 /* This is the magic location that prints prompts
1301 * and gets data back from the user */
1302 static int file_get(struct in_str *i)
1306 /* If there is data waiting, eat it up */
1307 if (i->p && *i->p) {
1308 #if ENABLE_HUSH_INTERACTIVE
1312 if (i->eof_flag && !*i->p)
1314 /* note: ch is never NUL */
1316 /* need to double check i->file because we might be doing something
1317 * more complicated by now, like sourcing or substituting. */
1318 #if ENABLE_HUSH_INTERACTIVE
1319 if (G_interactive_fd && i->promptme && i->file == stdin) {
1322 } while (!*i->p); /* need non-empty line */
1323 i->promptmode = 1; /* PS2 */
1328 do ch = fgetc(i->file); while (ch == '\0');
1330 debug_printf("file_get: got '%c' %d\n", ch, ch);
1331 #if ENABLE_HUSH_INTERACTIVE
1338 /* All callers guarantee this routine will never
1339 * be used right after a newline, so prompting is not needed.
1341 static int file_peek(struct in_str *i)
1344 if (i->p && *i->p) {
1345 if (i->eof_flag && !i->p[1])
1348 /* note: ch is never NUL */
1350 do ch = fgetc(i->file); while (ch == '\0');
1351 i->eof_flag = (ch == EOF);
1352 i->peek_buf[0] = ch;
1353 i->peek_buf[1] = '\0';
1355 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1359 static void setup_file_in_str(struct in_str *i, FILE *f)
1361 i->peek = file_peek;
1363 #if ENABLE_HUSH_INTERACTIVE
1365 i->promptmode = 0; /* PS1 */
1371 static void setup_string_in_str(struct in_str *i, const char *s)
1373 i->peek = static_peek;
1374 i->get = static_get;
1375 #if ENABLE_HUSH_INTERACTIVE
1377 i->promptmode = 0; /* PS1 */
1387 #define B_CHUNK (32 * sizeof(char*))
1389 static void o_reset(o_string *o)
1397 static void o_free(o_string *o)
1400 memset(o, 0, sizeof(*o));
1403 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1408 static void o_grow_by(o_string *o, int len)
1410 if (o->length + len > o->maxlen) {
1411 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1412 o->data = xrealloc(o->data, 1 + o->maxlen);
1416 static void o_addchr(o_string *o, int ch)
1418 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1420 o->data[o->length] = ch;
1422 o->data[o->length] = '\0';
1425 static void o_addblock(o_string *o, const char *str, int len)
1428 memcpy(&o->data[o->length], str, len);
1430 o->data[o->length] = '\0';
1434 static void o_addstr(o_string *o, const char *str)
1436 o_addblock(o, str, strlen(str));
1438 static void nommu_addchr(o_string *o, int ch)
1444 #define nommu_addchr(o, str) ((void)0)
1447 static void o_addstr_with_NUL(o_string *o, const char *str)
1449 o_addblock(o, str, strlen(str) + 1);
1452 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1457 && (*str != '*' && *str != '?' && *str != '[')
1465 /* My analysis of quoting semantics tells me that state information
1466 * is associated with a destination, not a source.
1468 static void o_addqchr(o_string *o, int ch)
1471 char *found = strchr("*?[\\", ch);
1476 o->data[o->length] = '\\';
1479 o->data[o->length] = ch;
1481 o->data[o->length] = '\0';
1484 static void o_addQchr(o_string *o, int ch)
1487 if (o->o_escape && strchr("*?[\\", ch)) {
1489 o->data[o->length] = '\\';
1493 o->data[o->length] = ch;
1495 o->data[o->length] = '\0';
1498 static void o_addQstr(o_string *o, const char *str, int len)
1501 o_addblock(o, str, len);
1507 int ordinary_cnt = strcspn(str, "*?[\\");
1508 if (ordinary_cnt > len) /* paranoia */
1510 o_addblock(o, str, ordinary_cnt);
1511 if (ordinary_cnt == len)
1513 str += ordinary_cnt;
1514 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1518 if (ch) { /* it is necessarily one of "*?[\\" */
1520 o->data[o->length] = '\\';
1524 o->data[o->length] = ch;
1526 o->data[o->length] = '\0';
1530 /* A special kind of o_string for $VAR and `cmd` expansion.
1531 * It contains char* list[] at the beginning, which is grown in 16 element
1532 * increments. Actual string data starts at the next multiple of 16 * (char*).
1533 * list[i] contains an INDEX (int!) into this string data.
1534 * It means that if list[] needs to grow, data needs to be moved higher up
1535 * but list[i]'s need not be modified.
1536 * NB: remembering how many list[i]'s you have there is crucial.
1537 * o_finalize_list() operation post-processes this structure - calculates
1538 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1540 #if DEBUG_EXPAND || DEBUG_GLOB
1541 static void debug_print_list(const char *prefix, o_string *o, int n)
1543 char **list = (char**)o->data;
1544 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1546 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1547 prefix, list, n, string_start, o->length, o->maxlen);
1549 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1550 o->data + (int)list[i] + string_start,
1551 o->data + (int)list[i] + string_start);
1555 const char *p = o->data + (int)list[n - 1] + string_start;
1556 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1560 #define debug_print_list(prefix, o, n) ((void)0)
1563 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1564 * in list[n] so that it points past last stored byte so far.
1565 * It returns n+1. */
1566 static int o_save_ptr_helper(o_string *o, int n)
1568 char **list = (char**)o->data;
1572 if (!o->has_empty_slot) {
1573 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1574 string_len = o->length - string_start;
1575 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1576 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1577 /* list[n] points to string_start, make space for 16 more pointers */
1578 o->maxlen += 0x10 * sizeof(list[0]);
1579 o->data = xrealloc(o->data, o->maxlen + 1);
1580 list = (char**)o->data;
1581 memmove(list + n + 0x10, list + n, string_len);
1582 o->length += 0x10 * sizeof(list[0]);
1584 debug_printf_list("list[%d]=%d string_start=%d\n",
1585 n, string_len, string_start);
1588 /* We have empty slot at list[n], reuse without growth */
1589 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1590 string_len = o->length - string_start;
1591 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1592 n, string_len, string_start);
1593 o->has_empty_slot = 0;
1595 list[n] = (char*)(ptrdiff_t)string_len;
1599 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1600 static int o_get_last_ptr(o_string *o, int n)
1602 char **list = (char**)o->data;
1603 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1605 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1608 /* o_glob performs globbing on last list[], saving each result
1609 * as a new list[]. */
1610 static int o_glob(o_string *o, int n)
1616 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1618 return o_save_ptr_helper(o, n);
1619 pattern = o->data + o_get_last_ptr(o, n);
1620 debug_printf_glob("glob pattern '%s'\n", pattern);
1621 if (!glob_needed(pattern)) {
1623 o->length = unbackslash(pattern) - o->data;
1624 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1625 return o_save_ptr_helper(o, n);
1628 memset(&globdata, 0, sizeof(globdata));
1629 gr = glob(pattern, 0, NULL, &globdata);
1630 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1631 if (gr == GLOB_NOSPACE)
1632 bb_error_msg_and_die("out of memory during glob");
1633 if (gr == GLOB_NOMATCH) {
1634 globfree(&globdata);
1637 if (gr != 0) { /* GLOB_ABORTED ? */
1638 //TODO: testcase for bad glob pattern behavior
1639 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1641 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1642 char **argv = globdata.gl_pathv;
1643 o->length = pattern - o->data; /* "forget" pattern */
1645 o_addstr_with_NUL(o, *argv);
1646 n = o_save_ptr_helper(o, n);
1652 globfree(&globdata);
1654 debug_print_list("o_glob returning", o, n);
1658 /* If o->o_glob == 1, glob the string so far remembered.
1659 * Otherwise, just finish current list[] and start new */
1660 static int o_save_ptr(o_string *o, int n)
1662 if (o->o_glob) { /* if globbing is requested */
1663 /* If o->has_empty_slot, list[n] was already globbed
1664 * (if it was requested back then when it was filled)
1665 * so don't do that again! */
1666 if (!o->has_empty_slot)
1667 return o_glob(o, n); /* o_save_ptr_helper is inside */
1669 return o_save_ptr_helper(o, n);
1672 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1673 static char **o_finalize_list(o_string *o, int n)
1678 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1680 debug_print_list("finalized", o, n);
1681 debug_printf_expand("finalized n:%d\n", n);
1682 list = (char**)o->data;
1683 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1687 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1693 /* Expansion can recurse */
1694 #if ENABLE_HUSH_TICK
1695 static int process_command_subs(o_string *dest, const char *s);
1697 static char *expand_string_to_string(const char *str);
1699 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1700 parse_stream_dquoted(dest, input, dquote_end)
1702 static int parse_stream_dquoted(o_string *as_string,
1704 struct in_str *input,
1707 /* expand_strvec_to_strvec() takes a list of strings, expands
1708 * all variable references within and returns a pointer to
1709 * a list of expanded strings, possibly with larger number
1710 * of strings. (Think VAR="a b"; echo $VAR).
1711 * This new list is allocated as a single malloc block.
1712 * NULL-terminated list of char* pointers is at the beginning of it,
1713 * followed by strings themself.
1714 * Caller can deallocate entire list by single free(list). */
1716 /* Store given string, finalizing the word and starting new one whenever
1717 * we encounter IFS char(s). This is used for expanding variable values.
1718 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1719 static int expand_on_ifs(o_string *output, int n, const char *str)
1722 int word_len = strcspn(str, G.ifs);
1724 if (output->o_escape || !output->o_glob)
1725 o_addQstr(output, str, word_len);
1726 else /* protect backslashes against globbing up :) */
1727 o_addblock_duplicate_backslash(output, str, word_len);
1730 if (!*str) /* EOL - do not finalize word */
1732 o_addchr(output, '\0');
1733 debug_print_list("expand_on_ifs", output, n);
1734 n = o_save_ptr(output, n);
1735 str += strspn(str, G.ifs); /* skip ifs chars */
1737 debug_print_list("expand_on_ifs[1]", output, n);
1741 /* Helper to expand $((...)) and heredoc body. These act as if
1742 * they are in double quotes, with the exception that they are not :).
1743 * Just the rules are similar: "expand only $var and `cmd`"
1745 * Returns malloced string.
1746 * As an optimization, we return NULL if expansion is not needed.
1748 static char *expand_pseudo_dquoted(const char *str)
1751 struct in_str input;
1752 o_string dest = NULL_O_STRING;
1754 if (strchr(str, '$') == NULL
1755 #if ENABLE_HUSH_TICK
1756 && strchr(str, '`') == NULL
1762 /* We need to expand. Example:
1763 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1765 setup_string_in_str(&input, str);
1766 parse_stream_dquoted(NULL, &dest, &input, EOF);
1767 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1768 exp_str = expand_string_to_string(dest.data);
1769 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1770 o_free_unsafe(&dest);
1774 /* Expand all variable references in given string, adding words to list[]
1775 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1776 * to be filled). This routine is extremely tricky: has to deal with
1777 * variables/parameters with whitespace, $* and $@, and constructs like
1778 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1779 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1781 /* or_mask is either 0 (normal case) or 0x80
1782 * (expansion of right-hand side of assignment == 1-element expand.
1783 * It will also do no globbing, and thus we must not backslash-quote!) */
1785 char first_ch, ored_ch;
1793 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1794 debug_print_list("expand_vars_to_list", output, n);
1795 n = o_save_ptr(output, n);
1796 debug_print_list("expand_vars_to_list[0]", output, n);
1798 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1799 #if ENABLE_HUSH_TICK
1800 o_string subst_result = NULL_O_STRING;
1802 #if ENABLE_SH_MATH_SUPPORT
1803 char arith_buf[sizeof(arith_t)*3 + 2];
1805 o_addblock(output, arg, p - arg);
1806 debug_print_list("expand_vars_to_list[1]", output, n);
1808 p = strchr(p, SPECIAL_VAR_SYMBOL);
1810 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1811 /* "$@" is special. Even if quoted, it can still
1812 * expand to nothing (not even an empty string) */
1813 if ((first_ch & 0x7f) != '@')
1814 ored_ch |= first_ch;
1817 switch (first_ch & 0x7f) {
1818 /* Highest bit in first_ch indicates that var is double-quoted */
1820 val = utoa(G.root_pid);
1822 case '!': /* bg pid */
1823 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1825 case '?': /* exitcode */
1826 val = utoa(G.last_exitcode);
1828 case '#': /* argc */
1829 if (arg[1] != SPECIAL_VAR_SYMBOL)
1830 /* actually, it's a ${#var} */
1832 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1837 if (!G.global_argv[i])
1839 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1840 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1841 smallint sv = output->o_escape;
1842 /* unquoted var's contents should be globbed, so don't escape */
1843 output->o_escape = 0;
1844 while (G.global_argv[i]) {
1845 n = expand_on_ifs(output, n, G.global_argv[i]);
1846 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1847 if (G.global_argv[i++][0] && G.global_argv[i]) {
1848 /* this argv[] is not empty and not last:
1849 * put terminating NUL, start new word */
1850 o_addchr(output, '\0');
1851 debug_print_list("expand_vars_to_list[2]", output, n);
1852 n = o_save_ptr(output, n);
1853 debug_print_list("expand_vars_to_list[3]", output, n);
1856 output->o_escape = sv;
1858 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1859 * and in this case should treat it like '$*' - see 'else...' below */
1860 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1862 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1863 if (++i >= G.global_argc)
1865 o_addchr(output, '\0');
1866 debug_print_list("expand_vars_to_list[4]", output, n);
1867 n = o_save_ptr(output, n);
1869 } else { /* quoted $*: add as one word */
1871 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1872 if (!G.global_argv[++i])
1875 o_addchr(output, G.ifs[0]);
1879 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1880 /* "Empty variable", used to make "" etc to not disappear */
1884 #if ENABLE_HUSH_TICK
1885 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1888 //TODO: can we just stuff it into "output" directly?
1889 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1890 process_command_subs(&subst_result, arg);
1891 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1892 val = subst_result.data;
1895 #if ENABLE_SH_MATH_SUPPORT
1896 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1897 arith_eval_hooks_t hooks;
1902 arg++; /* skip '+' */
1903 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1904 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1906 exp_str = expand_pseudo_dquoted(arg);
1907 hooks.lookupvar = get_local_var_value;
1908 hooks.setvar = arith_set_local_var;
1909 hooks.endofname = endofname;
1910 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1915 case -3: maybe_die("arith", "exponent less than 0"); break;
1916 case -2: maybe_die("arith", "divide by zero"); break;
1917 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1918 default: maybe_die("arith", "syntax error"); break;
1921 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1922 sprintf(arith_buf, arith_t_fmt, res);
1927 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1929 bool exp_len = false;
1930 bool exp_null = false;
1932 char exp_save = exp_save; /* for compiler */
1933 char exp_op = exp_op; /* for compiler */
1934 char *exp_word = exp_word; /* for compiler */
1938 arg[0] = first_ch & 0x7f;
1940 /* prepare for expansions */
1941 if (var[0] == '#') {
1942 /* handle length expansion ${#var} */
1946 /* maybe handle parameter expansion */
1947 exp_off = strcspn(var, ":-=+?%#");
1951 exp_save = var[exp_off];
1952 exp_null = exp_save == ':';
1953 exp_word = var + exp_off;
1954 if (exp_null) ++exp_word;
1955 exp_op = *exp_word++;
1956 var[exp_off] = '\0';
1960 /* lookup the variable in question */
1961 if (isdigit(var[0])) {
1962 /* handle_dollar() should have vetted var for us */
1964 if (i < G.global_argc)
1965 val = G.global_argv[i];
1966 /* else val remains NULL: $N with too big N */
1968 val = get_local_var_value(var);
1970 /* handle any expansions */
1972 debug_printf_expand("expand: length of '%s' = ", val);
1973 val = utoa(val ? strlen(val) : 0);
1974 debug_printf_expand("%s\n", val);
1975 } else if (exp_off) {
1976 if (exp_op == '%' || exp_op == '#') {
1977 /* we need to do a pattern match */
1980 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1981 if (exp_op == *exp_word) /* ## or %% */
1983 val = dyn_val = xstrdup(val);
1984 loc = scan(dyn_val, exp_word, zero);
1990 /* we need to do an expansion */
1991 int exp_test = (!val || (exp_null && !val[0]));
1993 exp_test = !exp_test;
1994 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1995 exp_null ? "true" : "false", exp_test);
1998 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
2002 if (exp_op == '=') {
2003 if (isdigit(var[0]) || var[0] == '#') {
2004 maybe_die(var, "special vars cannot assign in this way");
2007 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
2008 sprintf(new_var, "%s=%s", var, val);
2009 set_local_var(new_var, -1, 0);
2015 var[exp_off] = exp_save;
2019 #if ENABLE_HUSH_TICK
2022 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2023 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2025 /* unquoted var's contents should be globbed, so don't escape */
2026 smallint sv = output->o_escape;
2027 output->o_escape = 0;
2028 n = expand_on_ifs(output, n, val);
2030 output->o_escape = sv;
2032 } else { /* quoted $VAR, val will be appended below */
2033 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2036 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2038 o_addQstr(output, val, strlen(val));
2042 /* Do the check to avoid writing to a const string */
2043 if (*p != SPECIAL_VAR_SYMBOL)
2044 *p = SPECIAL_VAR_SYMBOL;
2046 #if ENABLE_HUSH_TICK
2047 o_free(&subst_result);
2050 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2053 debug_print_list("expand_vars_to_list[a]", output, n);
2054 /* this part is literal, and it was already pre-quoted
2055 * if needed (much earlier), do not use o_addQstr here! */
2056 o_addstr_with_NUL(output, arg);
2057 debug_print_list("expand_vars_to_list[b]", output, n);
2058 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2059 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2062 /* allow to reuse list[n] later without re-growth */
2063 output->has_empty_slot = 1;
2065 o_addchr(output, '\0');
2070 static char **expand_variables(char **argv, int or_mask)
2075 o_string output = NULL_O_STRING;
2077 if (or_mask & 0x100) {
2078 output.o_escape = 1; /* protect against globbing for "$var" */
2079 /* (unquoted $var will temporarily switch it off) */
2086 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2089 debug_print_list("expand_variables", &output, n);
2091 /* output.data (malloced in one block) gets returned in "list" */
2092 list = o_finalize_list(&output, n);
2093 debug_print_strings("expand_variables[1]", list);
2097 static char **expand_strvec_to_strvec(char **argv)
2099 return expand_variables(argv, 0x100);
2102 /* Used for expansion of right hand of assignments */
2103 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2105 static char *expand_string_to_string(const char *str)
2107 char *argv[2], **list;
2109 argv[0] = (char*)str;
2111 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2113 if (!list[0] || list[1])
2114 bb_error_msg_and_die("BUG in varexp2");
2115 /* actually, just move string 2*sizeof(char*) bytes back */
2116 overlapping_strcpy((char*)list, list[0]);
2117 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2121 /* Used for "eval" builtin */
2122 static char* expand_strvec_to_string(char **argv)
2126 list = expand_variables(argv, 0x80);
2127 /* Convert all NULs to spaces */
2132 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2133 bb_error_msg_and_die("BUG in varexp3");
2134 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2138 overlapping_strcpy((char*)list, list[0]);
2139 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2143 static char **expand_assignments(char **argv, int count)
2147 /* Expand assignments into one string each */
2148 for (i = 0; i < count; i++) {
2149 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2156 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2157 #define clean_up_after_re_execute() ((void)0)
2158 static void reset_traps_to_defaults(void)
2166 for (sig = 0; sig < NSIG; sig++) {
2170 G.traps[sig] = NULL;
2171 /* There is no signal for 0 (EXIT) */
2174 /* there was a trap handler, we are removing it
2175 * (if sig has non-DFL handling,
2176 * we don't need to do anything) */
2177 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2179 sigdelset(&G.blocked_set, sig);
2183 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2188 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2189 static void re_execute_shell(const char *s, int is_heredoc)
2191 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2192 char *heredoc_argv[4];
2193 struct variable *cur;
2194 char **argv, **pp, **pp2;
2198 argv = heredoc_argv;
2199 argv[0] = (char *) G.argv0_for_re_execing;
2200 argv[1] = (char *) "-<";
2201 argv[2] = (char *) s;
2203 pp = &argv[3]; /* used as pointer to empty environment */
2207 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2208 , (unsigned) G.root_pid
2209 , (unsigned) G.last_bg_pid
2210 , (unsigned) G.last_exitcode
2211 USE_HUSH_LOOPS(, G.depth_of_loop)
2213 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2214 * 3:-c 4:<cmd> <argN...> 5:NULL
2216 cnt = 5 + G.global_argc;
2217 for (cur = G.top_var; cur; cur = cur->next) {
2218 if (!cur->flg_export || cur->flg_read_only)
2221 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2222 *pp++ = (char *) G.argv0_for_re_execing;
2224 for (cur = G.top_var; cur; cur = cur->next) {
2225 if (cur->varstr == hush_version_str)
2227 if (cur->flg_read_only) {
2228 *pp++ = (char *) "-R";
2229 *pp++ = cur->varstr;
2230 } else if (!cur->flg_export) {
2231 *pp++ = (char *) "-V";
2232 *pp++ = cur->varstr;
2235 //TODO: pass functions
2236 /* We can pass activated traps here. Say, -Tnn:trap_string
2238 * However, POSIX says that subshells reset signals with traps
2240 * I tested bash-3.2 and it not only does that with true subshells
2241 * of the form ( list ), but with any forked children shells.
2242 * I set trap "echo W" WINCH; and then tried:
2244 * { echo 1; sleep 20; echo 2; } &
2245 * while true; do echo 1; sleep 20; echo 2; break; done &
2246 * true | { echo 1; sleep 20; echo 2; } | cat
2248 * In all these cases sending SIGWINCH to the child shell
2249 * did not run the trap. If I add trap "echo V" WINCH;
2250 * _inside_ group (just before echo 1), it works.
2252 * I conclude it means we don't need to pass active traps here.
2253 * exec syscall below resets them to SIG_DFL for us.
2255 *pp++ = (char *) "-c";
2257 pp2 = G.global_argv;
2260 /* *pp = NULL; - is already there */
2264 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2265 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2266 execve(bb_busybox_exec_path, argv, pp);
2267 /* Fallback. Useful for init=/bin/hush usage etc */
2268 if (argv[0][0] == '/')
2269 execve(argv[0], argv, pp);
2270 xfunc_error_retval = 127;
2271 bb_error_msg_and_die("can't re-execute the shell");
2274 static void clean_up_after_re_execute(void)
2276 char **pp = G.argv_from_re_execing;
2278 /* Must match re_execute_shell's allocations (if any) */
2280 G.argv_from_re_execing = NULL;
2283 #endif /* !BB_MMU */
2286 static void setup_heredoc(struct redir_struct *redir)
2288 struct fd_pair pair;
2291 /* the _body_ of heredoc (misleading field name) */
2292 const char *heredoc = redir->rd_filename;
2296 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2297 expanded = expand_pseudo_dquoted(heredoc);
2301 len = strlen(heredoc);
2303 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2305 xmove_fd(pair.rd, redir->rd_fd);
2307 /* Try writing without forking. Newer kernels have
2308 * dynamically growing pipes. Must use non-blocking write! */
2311 written = write(pair.wr, heredoc, len);
2322 ndelay_off(pair.wr);
2324 /* Okay, pipe buffer was not big enough */
2325 /* Note: we must not create a stray child (bastard? :)
2326 * for the unsuspecting parent process. Child creates a grandchild
2327 * and exits before parent execs the process which consumes heredoc
2328 * (that exec happens after we return from this function) */
2331 bb_perror_msg_and_die("vfork");
2334 pid = BB_MMU ? fork() : vfork();
2336 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2340 close(redir->rd_fd); /* read side of the pipe */
2342 full_write(pair.wr, heredoc, len); /* may loop or block */
2345 /* Delegate blocking writes to another process */
2346 disable_restore_tty_pgrp_on_exit();
2347 xmove_fd(pair.wr, STDOUT_FILENO);
2348 re_execute_shell(heredoc, 1);
2352 enable_restore_tty_pgrp_on_exit();
2353 clean_up_after_re_execute();
2356 wait(NULL); /* wait till child has died */
2359 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2360 * and stderr if they are redirected. */
2361 static int setup_redirects(struct command *prog, int squirrel[])
2364 struct redir_struct *redir;
2366 for (redir = prog->redirects; redir; redir = redir->next) {
2367 if (redir->rd_type == REDIRECT_HEREDOC2) {
2368 if (squirrel && redir->rd_fd < 3) {
2369 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2371 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2373 debug_printf_parse("set heredoc '%s'\n",
2374 redir->rd_filename);
2375 setup_heredoc(redir);
2379 if (redir->rd_dup == -1) {
2381 if (redir->rd_filename == NULL) {
2382 /* Something went wrong in the parse.
2383 * Pretend it didn't happen */
2386 mode = redir_table[redir->rd_type].mode;
2387 //TODO: check redir for names like '\\'
2388 p = expand_string_to_string(redir->rd_filename);
2389 openfd = open_or_warn(p, mode);
2392 /* this could get lost if stderr has been redirected, but
2393 * bash and ash both lose it as well (though zsh doesn't!) */
2394 //what the above comment tries to say?
2398 openfd = redir->rd_dup;
2401 if (openfd != redir->rd_fd) {
2402 if (squirrel && redir->rd_fd < 3) {
2403 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2405 if (openfd == REDIRFD_CLOSE) {
2406 /* "n>-" means "close me" */
2407 close(redir->rd_fd);
2409 xdup2(openfd, redir->rd_fd);
2410 if (redir->rd_dup == -1)
2418 static void restore_redirects(int squirrel[])
2421 for (i = 0; i < 3; i++) {
2424 /* We simply die on error */
2432 #define free_pipe_list(head, indent) free_pipe_list(head)
2433 #define free_pipe(pi, indent) free_pipe(pi)
2435 static void free_pipe_list(struct pipe *head, int indent);
2437 /* Return code is the exit status of the pipe */
2438 static void free_pipe(struct pipe *pi, int indent)
2441 struct command *command;
2442 struct redir_struct *r, *rnext;
2445 if (pi->stopped_cmds > 0) /* why? */
2447 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2448 for (i = 0; i < pi->num_cmds; i++) {
2449 command = &pi->cmds[i];
2450 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2451 if (command->argv) {
2452 for (a = 0, p = command->argv; *p; a++, p++) {
2453 debug_printf_clean("%s argv[%d] = %s\n",
2454 indenter(indent), a, *p);
2456 free_strings(command->argv);
2457 command->argv = NULL;
2459 /* not "else if": on syntax error, we may have both! */
2460 if (command->group) {
2461 debug_printf_clean("%s begin group (grp_type:%d)\n",
2462 indenter(indent), command->grp_type);
2463 free_pipe_list(command->group, indent+3);
2464 debug_printf_clean("%s end group\n", indenter(indent));
2465 command->group = NULL;
2468 free(command->group_as_string);
2469 command->group_as_string = NULL;
2471 for (r = command->redirects; r; r = rnext) {
2472 debug_printf_clean("%s redirect %d%s", indenter(indent),
2473 r->fd, redir_table[r->rd_type].descrip);
2474 /* guard against the case >$FOO, where foo is unset or blank */
2475 if (r->rd_filename) {
2476 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2477 free(r->rd_filename);
2478 r->rd_filename = NULL;
2480 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2484 command->redirects = NULL;
2486 free(pi->cmds); /* children are an array, they get freed all at once */
2494 static void free_pipe_list(struct pipe *head, int indent)
2496 struct pipe *pi, *next;
2498 for (pi = head; pi; pi = next) {
2500 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2502 free_pipe(pi, indent);
2503 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2505 /*pi->next = NULL;*/
2512 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2513 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2514 #define pseudo_exec(nommu_save, command, argv_expanded) \
2515 pseudo_exec(command, argv_expanded)
2518 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2520 * XXX no exit() here. If you don't exec, use _exit instead.
2521 * The at_exit handlers apparently confuse the calling process,
2522 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2523 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2524 char **argv, int assignment_cnt,
2525 char **argv_expanded) NORETURN;
2526 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2527 char **argv, int assignment_cnt,
2528 char **argv_expanded)
2532 /* Case when we are here: ... | var=val | ... */
2533 if (!argv[assignment_cnt])
2534 _exit(EXIT_SUCCESS);
2536 new_env = expand_assignments(argv, assignment_cnt);
2538 putenv_all(new_env);
2539 free(new_env); /* optional */
2541 nommu_save->new_env = new_env;
2542 nommu_save->old_env = putenv_all_and_save_old(new_env);
2544 if (argv_expanded) {
2545 argv = argv_expanded;
2547 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2549 nommu_save->argv = argv;
2553 /* On NOMMU, we must never block!
2554 * Example: { sleep 99999 | read line } & echo Ok
2555 * read builtin will block on read syscall, leaving parent blocked
2556 * in vfork. Therefore we can't do this:
2559 /* Check if the command matches any of the builtins.
2560 * Depending on context, this might be redundant. But it's
2561 * easier to waste a few CPU cycles than it is to figure out
2562 * if this is one of those cases.
2566 const struct built_in_command *x;
2567 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2568 if (strcmp(argv[0], x->cmd) == 0) {
2569 debug_printf_exec("running builtin '%s'\n",
2571 rcode = x->function(argv);
2579 #if ENABLE_FEATURE_SH_STANDALONE
2580 /* Check if the command matches any busybox applets */
2581 if (strchr(argv[0], '/') == NULL) {
2582 int a = find_applet_by_name(argv[0]);
2584 #if BB_MMU /* see above why on NOMMU it is not allowed */
2585 if (APPLET_IS_NOEXEC(a)) {
2586 debug_printf_exec("running applet '%s'\n", argv[0]);
2587 run_applet_no_and_exit(a, argv);
2590 /* Re-exec ourselves */
2591 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2592 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2593 execv(bb_busybox_exec_path, argv);
2594 /* If they called chroot or otherwise made the binary no longer
2595 * executable, fall through */
2600 debug_printf_exec("execing '%s'\n", argv[0]);
2601 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2602 execvp(argv[0], argv);
2603 bb_perror_msg("can't exec '%s'", argv[0]);
2604 _exit(EXIT_FAILURE);
2607 static int run_list(struct pipe *pi);
2609 /* Called after [v]fork() in run_pipe
2611 static void pseudo_exec(nommu_save_t *nommu_save,
2612 struct command *command,
2613 char **argv_expanded) NORETURN;
2614 static void pseudo_exec(nommu_save_t *nommu_save,
2615 struct command *command,
2616 char **argv_expanded)
2618 if (command->argv) {
2619 pseudo_exec_argv(nommu_save, command->argv,
2620 command->assignment_cnt, argv_expanded);
2623 if (command->group) {
2624 /* Cases when we are here:
2627 * ... | ( list ) | ...
2628 * ... | { list } | ...
2632 debug_printf_exec("pseudo_exec: run_list\n");
2633 reset_traps_to_defaults();
2634 rcode = run_list(command->group);
2635 /* OK to leak memory by not calling free_pipe_list,
2636 * since this process is about to exit */
2639 re_execute_shell(command->group_as_string, 0);
2643 /* Case when we are here: ... | >file */
2644 debug_printf_exec("pseudo_exec'ed null command\n");
2645 _exit(EXIT_SUCCESS);
2649 static const char *get_cmdtext(struct pipe *pi)
2655 /* This is subtle. ->cmdtext is created only on first backgrounding.
2656 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2657 * On subsequent bg argv is trashed, but we won't use it */
2660 argv = pi->cmds[0].argv;
2661 if (!argv || !argv[0]) {
2662 pi->cmdtext = xzalloc(1);
2667 do len += strlen(*argv) + 1; while (*++argv);
2668 pi->cmdtext = p = xmalloc(len);
2669 argv = pi->cmds[0].argv;
2671 len = strlen(*argv);
2672 memcpy(p, *argv, len);
2680 static void insert_bg_job(struct pipe *pi)
2682 struct pipe *thejob;
2685 /* Linear search for the ID of the job to use */
2687 for (thejob = G.job_list; thejob; thejob = thejob->next)
2688 if (thejob->jobid >= pi->jobid)
2689 pi->jobid = thejob->jobid + 1;
2691 /* Add thejob to the list of running jobs */
2693 thejob = G.job_list = xmalloc(sizeof(*thejob));
2695 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2697 thejob->next = xmalloc(sizeof(*thejob));
2698 thejob = thejob->next;
2701 /* Physically copy the struct job */
2702 memcpy(thejob, pi, sizeof(struct pipe));
2703 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2704 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2705 for (i = 0; i < pi->num_cmds; i++) {
2706 // TODO: do we really need to have so many fields which are just dead weight
2707 // at execution stage?
2708 thejob->cmds[i].pid = pi->cmds[i].pid;
2709 /* all other fields are not used and stay zero */
2711 thejob->next = NULL;
2712 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2714 /* We don't wait for background thejobs to return -- append it
2715 to the list of backgrounded thejobs and leave it alone */
2716 if (G_interactive_fd)
2717 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2718 G.last_bg_pid = thejob->cmds[0].pid;
2719 G.last_jobid = thejob->jobid;
2722 static void remove_bg_job(struct pipe *pi)
2724 struct pipe *prev_pipe;
2726 if (pi == G.job_list) {
2727 G.job_list = pi->next;
2729 prev_pipe = G.job_list;
2730 while (prev_pipe->next != pi)
2731 prev_pipe = prev_pipe->next;
2732 prev_pipe->next = pi->next;
2735 G.last_jobid = G.job_list->jobid;
2740 /* Remove a backgrounded job */
2741 static void delete_finished_bg_job(struct pipe *pi)
2744 pi->stopped_cmds = 0;
2750 /* Check to see if any processes have exited -- if they
2751 * have, figure out why and see if a job has completed */
2752 static int checkjobs(struct pipe* fg_pipe)
2762 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2765 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2766 // /* avoid doing syscall, nothing there anyway */
2769 attributes = WUNTRACED;
2770 if (fg_pipe == NULL)
2771 attributes |= WNOHANG;
2773 /* Do we do this right?
2774 * bash-3.00# sleep 20 | false
2776 * [3]+ Stopped sleep 20 | false
2777 * bash-3.00# echo $?
2778 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2781 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2782 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2783 // + killall -STOP cat
2790 // i = G.count_SIGCHLD;
2791 childpid = waitpid(-1, &status, attributes);
2792 if (childpid <= 0) {
2793 if (childpid && errno != ECHILD)
2794 bb_perror_msg("waitpid");
2795 // else /* Until next SIGCHLD, waitpid's are useless */
2796 // G.handled_SIGCHLD = i;
2799 dead = WIFEXITED(status) || WIFSIGNALED(status);
2802 if (WIFSTOPPED(status))
2803 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2804 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2805 if (WIFSIGNALED(status))
2806 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2807 childpid, WTERMSIG(status), WEXITSTATUS(status));
2808 if (WIFEXITED(status))
2809 debug_printf_jobs("pid %d exited, exitcode %d\n",
2810 childpid, WEXITSTATUS(status));
2812 /* Were we asked to wait for fg pipe? */
2814 for (i = 0; i < fg_pipe->num_cmds; i++) {
2815 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2816 if (fg_pipe->cmds[i].pid != childpid)
2818 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2820 fg_pipe->cmds[i].pid = 0;
2821 fg_pipe->alive_cmds--;
2822 if (i == fg_pipe->num_cmds - 1) {
2823 /* last process gives overall exitstatus */
2824 rcode = WEXITSTATUS(status);
2825 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2828 fg_pipe->cmds[i].is_stopped = 1;
2829 fg_pipe->stopped_cmds++;
2831 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2832 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2833 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2834 /* All processes in fg pipe have exited/stopped */
2836 if (fg_pipe->alive_cmds)
2837 insert_bg_job(fg_pipe);
2841 /* There are still running processes in the fg pipe */
2842 goto wait_more; /* do waitpid again */
2844 /* it wasnt fg_pipe, look for process in bg pipes */
2848 /* We asked to wait for bg or orphaned children */
2849 /* No need to remember exitcode in this case */
2850 for (pi = G.job_list; pi; pi = pi->next) {
2851 for (i = 0; i < pi->num_cmds; i++) {
2852 if (pi->cmds[i].pid == childpid)
2853 goto found_pi_and_prognum;
2856 /* Happens when shell is used as init process (init=/bin/sh) */
2857 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2858 continue; /* do waitpid again */
2860 found_pi_and_prognum:
2863 pi->cmds[i].pid = 0;
2865 if (!pi->alive_cmds) {
2866 if (G_interactive_fd)
2867 printf(JOB_STATUS_FORMAT, pi->jobid,
2868 "Done", pi->cmdtext);
2869 delete_finished_bg_job(pi);
2873 pi->cmds[i].is_stopped = 1;
2877 } /* while (waitpid succeeds)... */
2883 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2886 int rcode = checkjobs(fg_pipe);
2887 /* Job finished, move the shell to the foreground */
2888 p = getpgid(0); /* pgid of our process */
2889 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2890 tcsetpgrp(G_interactive_fd, p);
2895 /* Start all the jobs, but don't wait for anything to finish.
2898 * Return code is normally -1, when the caller has to wait for children
2899 * to finish to determine the exit status of the pipe. If the pipe
2900 * is a simple builtin command, however, the action is done by the
2901 * time run_pipe returns, and the exit code is provided as the
2904 * Returns -1 only if started some children. IOW: we have to
2905 * mask out retvals of builtins etc with 0xff!
2907 * The only case when we do not need to [v]fork is when the pipe
2908 * is single, non-backgrounded, non-subshell command. Examples:
2909 * cmd ; ... { list } ; ...
2910 * cmd && ... { list } && ...
2911 * cmd || ... { list } || ...
2912 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2913 * or (if SH_STANDALONE) an applet, and we can run the { list }
2914 * with run_list(). If it isn't one of these, we fork and exec cmd.
2916 * Cases when we must fork:
2917 * non-single: cmd | cmd
2918 * backgrounded: cmd & { list } &
2919 * subshell: ( list ) [&]
2921 static int run_pipe(struct pipe *pi)
2923 static const char *const null_ptr = NULL;
2926 int pipefds[2]; /* pipefds[0] is for reading */
2927 struct command *command;
2928 char **argv_expanded;
2931 /* it is not always needed, but we aim to smaller code */
2932 int squirrel[] = { -1, -1, -1 };
2935 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2937 USE_HUSH_JOB(pi->pgrp = -1;)
2938 pi->stopped_cmds = 0;
2939 command = &(pi->cmds[0]);
2940 argv_expanded = NULL;
2942 if (pi->num_cmds != 1
2943 || pi->followup == PIPE_BG
2944 || command->grp_type == GRP_SUBSHELL
2951 debug_printf_exec(": group:%p argv:'%s'\n",
2952 command->group, command->argv ? command->argv[0] : "NONE");
2954 if (command->group) {
2955 #if ENABLE_HUSH_FUNCTIONS
2956 if (command->grp_type == GRP_FUNCTION) {
2957 /* func () { list } */
2958 bb_error_msg("here we ought to remember function definition, and go on");
2959 return EXIT_SUCCESS;
2963 debug_printf("non-subshell group\n");
2964 rcode = 1; /* exitcode if redir failed */
2965 if (setup_redirects(command, squirrel) == 0) {
2966 debug_printf_exec(": run_list\n");
2967 rcode = run_list(command->group) & 0xff;
2968 debug_printf_exec("run_pipe return %d\n", rcode);
2970 restore_redirects(squirrel);
2971 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2975 argv = command->argv ? command->argv : (char **) &null_ptr;
2977 const struct built_in_command *x;
2978 char **new_env = NULL;
2979 char **old_env = NULL;
2981 if (argv[command->assignment_cnt] == NULL) {
2982 /* Assignments, but no command */
2983 /* Ensure redirects take effect. Try "a=t >file" */
2984 rcode = setup_redirects(command, squirrel);
2985 restore_redirects(squirrel);
2986 /* Set shell variables */
2988 p = expand_string_to_string(*argv);
2989 debug_printf_exec("set shell var:'%s'->'%s'\n",
2991 set_local_var(p, 0, 0);
2994 /* Do we need to flag set_local_var() errors?
2995 * "assignment to readonly var" and "putenv error"
2997 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3001 /* Expand the rest into (possibly) many strings each */
3002 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3004 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
3005 if (strcmp(argv_expanded[0], x->cmd) != 0)
3007 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3008 debug_printf("exec with redirects only\n");
3009 rcode = setup_redirects(command, NULL);
3010 goto clean_up_and_ret1;
3012 debug_printf("builtin inline %s\n", argv_expanded[0]);
3013 /* XXX setup_redirects acts on file descriptors, not FILEs.
3014 * This is perfect for work that comes after exec().
3015 * Is it really safe for inline use? Experimentally,
3016 * things seem to work with glibc. */
3017 rcode = setup_redirects(command, squirrel);
3019 new_env = expand_assignments(argv, command->assignment_cnt);
3020 old_env = putenv_all_and_save_old(new_env);
3021 debug_printf_exec(": builtin '%s' '%s'...\n",
3022 x->cmd, argv_expanded[1]);
3023 rcode = x->function(argv_expanded) & 0xff;
3025 #if ENABLE_FEATURE_SH_STANDALONE
3028 restore_redirects(squirrel);
3029 free_strings_and_unsetenv(new_env, 1);
3030 putenv_all(old_env);
3031 /* Free the pointers, but the strings themselves
3032 * are in environ now, don't use free_strings! */
3035 free(argv_expanded);
3036 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3037 debug_printf_exec("run_pipe return %d\n", rcode);
3040 #if ENABLE_FEATURE_SH_STANDALONE
3041 i = find_applet_by_name(argv_expanded[0]);
3042 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3043 rcode = setup_redirects(command, squirrel);
3045 save_nofork_data(&G.nofork_save);
3046 new_env = expand_assignments(argv, command->assignment_cnt);
3047 old_env = putenv_all_and_save_old(new_env);
3048 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3049 argv_expanded[0], argv_expanded[1]);
3050 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3052 goto clean_up_and_ret;
3055 /* It is neither builtin nor applet. We must fork. */
3059 /* NB: argv_expanded may already be created, and that
3060 * might include `cmd` runs! Do not rerun it! We *must*
3061 * use argv_expanded if it's non-NULL */
3063 /* Going to fork a child per each pipe member */
3067 for (i = 0; i < pi->num_cmds; i++) {
3069 volatile nommu_save_t nommu_save;
3070 nommu_save.new_env = NULL;
3071 nommu_save.old_env = NULL;
3072 nommu_save.argv = NULL;
3074 command = &(pi->cmds[i]);
3075 if (command->argv) {
3076 debug_printf_exec(": pipe member '%s' '%s'...\n",
3077 command->argv[0], command->argv[1]);
3079 debug_printf_exec(": pipe member with no argv\n");
3082 /* pipes are inserted between pairs of commands */
3085 if ((i + 1) < pi->num_cmds)
3088 command->pid = BB_MMU ? fork() : vfork();
3089 if (!command->pid) { /* child */
3091 disable_restore_tty_pgrp_on_exit();
3093 /* Every child adds itself to new process group
3094 * with pgid == pid_of_first_child_in_pipe */
3095 if (G.run_list_level == 1 && G_interactive_fd) {
3098 if (pgrp < 0) /* true for 1st process only */
3100 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3101 /* We do it in *every* child, not just first,
3103 tcsetpgrp(G_interactive_fd, pgrp);
3107 xmove_fd(nextin, 0);
3108 xmove_fd(pipefds[1], 1); /* write end */
3110 close(pipefds[0]); /* read end */
3111 /* Like bash, explicit redirects override pipes,
3112 * and the pipe fd is available for dup'ing. */
3113 if (setup_redirects(command, NULL))
3116 /* Restore default handlers just prior to exec */
3117 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3119 /* Stores to nommu_save list of env vars putenv'ed
3120 * (NOMMU, on MMU we don't need that) */
3121 /* cast away volatility... */
3122 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3123 /* pseudo_exec() does not return */
3126 /* parent or error */
3127 enable_restore_tty_pgrp_on_exit();
3129 /* Clean up after vforked child */
3130 clean_up_after_re_execute();
3131 free(nommu_save.argv);
3132 free_strings_and_unsetenv(nommu_save.new_env, 1);
3133 putenv_all(nommu_save.old_env);
3134 /* Free the pointers, but the strings themselves
3135 * are in environ now, don't use free_strings! */
3136 free(nommu_save.old_env);
3138 free(argv_expanded);
3139 argv_expanded = NULL;
3140 if (command->pid < 0) { /* [v]fork failed */
3141 /* Clearly indicate, was it fork or vfork */
3142 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3146 /* Second and next children need to know pid of first one */
3148 pi->pgrp = command->pid;
3154 if ((i + 1) < pi->num_cmds)
3155 close(pipefds[1]); /* write end */
3156 /* Pass read (output) pipe end to next iteration */
3157 nextin = pipefds[0];
3160 if (!pi->alive_cmds) {
3161 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3165 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3169 #ifndef debug_print_tree
3170 static void debug_print_tree(struct pipe *pi, int lvl)
3172 static const char *const PIPE[] = {
3178 static const char *RES[] = {
3179 [RES_NONE ] = "NONE" ,
3182 [RES_THEN ] = "THEN" ,
3183 [RES_ELIF ] = "ELIF" ,
3184 [RES_ELSE ] = "ELSE" ,
3187 #if ENABLE_HUSH_LOOPS
3188 [RES_FOR ] = "FOR" ,
3189 [RES_WHILE] = "WHILE",
3190 [RES_UNTIL] = "UNTIL",
3192 [RES_DONE ] = "DONE" ,
3194 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3197 #if ENABLE_HUSH_CASE
3198 [RES_CASE ] = "CASE" ,
3199 [RES_MATCH] = "MATCH",
3200 [RES_CASEI] = "CASEI",
3201 [RES_ESAC ] = "ESAC" ,
3203 [RES_XXXX ] = "XXXX" ,
3204 [RES_SNTX ] = "SNTX" ,
3206 static const char *const GRPTYPE[] = {
3209 #if ENABLE_HUSH_FUNCTIONS
3218 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3219 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3221 while (prn < pi->num_cmds) {
3222 struct command *command = &pi->cmds[prn];
3223 char **argv = command->argv;
3225 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3227 command->assignment_cnt);
3228 if (command->group) {
3229 fprintf(stderr, " group %s: (argv=%p)\n",
3230 GRPTYPE[command->grp_type],
3232 debug_print_tree(command->group, lvl+1);
3236 if (argv) while (*argv) {
3237 fprintf(stderr, " '%s'", *argv);
3240 fprintf(stderr, "\n");
3249 /* NB: called by pseudo_exec, and therefore must not modify any
3250 * global data until exec/_exit (we can be a child after vfork!) */
3251 static int run_list(struct pipe *pi)
3253 #if ENABLE_HUSH_CASE
3254 char *case_word = NULL;
3256 #if ENABLE_HUSH_LOOPS
3257 struct pipe *loop_top = NULL;
3258 char *for_varname = NULL;
3259 char **for_lcur = NULL;
3260 char **for_list = NULL;
3262 smallint last_followup;
3264 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3265 smalluint cond_code = 0;
3267 enum { cond_code = 0 };
3270 smallint rword; /* enum reserved_style */
3271 smallint last_rword; /* ditto */
3274 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3276 #if ENABLE_HUSH_LOOPS
3277 /* Check syntax for "for" */
3278 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3279 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3281 /* current word is FOR or IN (BOLD in comments below) */
3282 if (cpipe->next == NULL) {
3283 syntax("malformed for");
3284 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3287 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3288 if (cpipe->next->res_word == RES_DO)
3290 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3291 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3292 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3294 syntax("malformed for");
3295 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3301 /* Past this point, all code paths should jump to ret: label
3302 * in order to return, no direct "return" statements please.
3303 * This helps to ensure that no memory is leaked. */
3305 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3308 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3309 * We are saving state before entering outermost list ("while...done")
3310 * so that ctrl-Z will correctly background _entire_ outermost list,
3311 * not just a part of it (like "sleep 1 | exit 2") */
3312 if (++G.run_list_level == 1 && G_interactive_fd) {
3313 if (sigsetjmp(G.toplevel_jb, 1)) {
3314 /* ctrl-Z forked and we are parent; or ctrl-C.
3315 * Sighandler has longjmped us here */
3316 signal(SIGINT, SIG_IGN);
3317 signal(SIGTSTP, SIG_IGN);
3318 /* Restore level (we can be coming from deep inside
3320 G.run_list_level = 1;
3321 #if ENABLE_FEATURE_SH_STANDALONE
3322 if (G.nofork_save.saved) { /* if save area is valid */
3323 debug_printf_jobs("exiting nofork early\n");
3324 restore_nofork_data(&G.nofork_save);
3327 //// if (G.ctrl_z_flag) {
3328 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3329 //// * Remember this child as background job */
3330 //// insert_bg_job(pi);
3332 /* ctrl-C. We just stop doing whatever we were doing */
3335 USE_HUSH_LOOPS(loop_top = NULL;)
3336 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3340 //// /* ctrl-Z handler will store pid etc in pi */
3341 //// G.toplevel_list = pi;
3342 //// G.ctrl_z_flag = 0;
3343 #if ENABLE_FEATURE_SH_STANDALONE
3344 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3346 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3347 //// signal(SIGINT, handler_ctrl_c);
3353 last_rword = RES_XXXX;
3355 last_followup = PIPE_SEQ;
3356 rcode = G.last_exitcode;
3358 /* Go through list of pipes, (maybe) executing them. */
3359 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3363 IF_HAS_KEYWORDS(rword = pi->res_word;)
3364 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3365 rword, cond_code, last_rword);
3366 #if ENABLE_HUSH_LOOPS
3367 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3368 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3370 /* start of a loop: remember where loop starts */
3375 /* Still in the same "if...", "then..." or "do..." branch? */
3376 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3377 if ((rcode == 0 && last_followup == PIPE_OR)
3378 || (rcode != 0 && last_followup == PIPE_AND)
3380 /* It is "<true> || CMD" or "<false> && CMD"
3381 * and we should not execute CMD */
3382 debug_printf_exec("skipped cmd because of || or &&\n");
3383 last_followup = pi->followup;
3387 last_followup = pi->followup;
3388 IF_HAS_KEYWORDS(last_rword = rword;)
3391 if (rword == RES_THEN) {
3392 /* if false; then ... fi has exitcode 0! */
3393 G.last_exitcode = rcode = EXIT_SUCCESS;
3394 /* "if <false> THEN cmd": skip cmd */
3398 if (rword == RES_ELSE || rword == RES_ELIF) {
3399 /* "if <true> then ... ELSE/ELIF cmd":
3400 * skip cmd and all following ones */
3405 #if ENABLE_HUSH_LOOPS
3406 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3408 /* first loop through for */
3410 static const char encoded_dollar_at[] ALIGN1 = {
3411 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3412 }; /* encoded representation of "$@" */
3413 static const char *const encoded_dollar_at_argv[] = {
3414 encoded_dollar_at, NULL
3415 }; /* argv list with one element: "$@" */
3418 vals = (char**)encoded_dollar_at_argv;
3419 if (pi->next->res_word == RES_IN) {
3420 /* if no variable values after "in" we skip "for" */
3421 if (!pi->next->cmds[0].argv) {
3422 G.last_exitcode = rcode = EXIT_SUCCESS;
3423 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3426 vals = pi->next->cmds[0].argv;
3427 } /* else: "for var; do..." -> assume "$@" list */
3428 /* create list of variable values */
3429 debug_print_strings("for_list made from", vals);
3430 for_list = expand_strvec_to_strvec(vals);
3431 for_lcur = for_list;
3432 debug_print_strings("for_list", for_list);
3433 for_varname = pi->cmds[0].argv[0];
3434 pi->cmds[0].argv[0] = NULL;
3436 free(pi->cmds[0].argv[0]);
3438 /* "for" loop is over, clean up */
3442 pi->cmds[0].argv[0] = for_varname;
3445 /* Insert next value from for_lcur */
3446 //TODO: does it need escaping?
3447 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3448 pi->cmds[0].assignment_cnt = 1;
3450 if (rword == RES_IN) {
3451 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3453 if (rword == RES_DONE) {
3454 continue; /* "done" has no cmds too */
3457 #if ENABLE_HUSH_CASE
3458 if (rword == RES_CASE) {
3459 case_word = expand_strvec_to_string(pi->cmds->argv);
3462 if (rword == RES_MATCH) {
3465 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3467 /* all prev words didn't match, does this one match? */
3468 argv = pi->cmds->argv;
3470 char *pattern = expand_string_to_string(*argv);
3471 /* TODO: which FNM_xxx flags to use? */
3472 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3474 if (cond_code == 0) { /* match! we will execute this branch */
3475 free(case_word); /* make future "word)" stop */
3483 if (rword == RES_CASEI) { /* inside of a case branch */
3485 continue; /* not matched yet, skip this pipe */
3488 /* Just pressing <enter> in shell should check for jobs.
3489 * OTOH, in non-interactive shell this is useless
3490 * and only leads to extra job checks */
3491 if (pi->num_cmds == 0) {
3492 if (G_interactive_fd)
3493 goto check_jobs_and_continue;
3497 /* After analyzing all keywords and conditions, we decided
3498 * to execute this pipe. NB: have to do checkjobs(NULL)
3499 * after run_pipe to collect any background children,
3500 * even if list execution is to be stopped. */
3501 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3504 #if ENABLE_HUSH_LOOPS
3505 G.flag_break_continue = 0;
3507 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3509 /* We only ran a builtin: rcode is already known
3510 * and we don't need to wait for anything. */
3511 G.last_exitcode = rcode;
3512 debug_printf_exec(": builtin exitcode %d\n", rcode);
3513 check_and_run_traps(0);
3514 #if ENABLE_HUSH_LOOPS
3515 /* Was it "break" or "continue"? */
3516 if (G.flag_break_continue) {
3517 smallint fbc = G.flag_break_continue;
3518 /* We might fall into outer *loop*,
3519 * don't want to break it too */
3521 G.depth_break_continue--;
3522 if (G.depth_break_continue == 0)
3523 G.flag_break_continue = 0;
3524 /* else: e.g. "continue 2" should *break* once, *then* continue */
3525 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3526 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3527 goto check_jobs_and_break;
3528 /* "continue": simulate end of loop */
3533 } else if (pi->followup == PIPE_BG) {
3534 /* What does bash do with attempts to background builtins? */
3535 /* even bash 3.2 doesn't do that well with nested bg:
3536 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3537 * I'm NOT treating inner &'s as jobs */
3538 check_and_run_traps(0);
3540 if (G.run_list_level == 1)
3543 G.last_exitcode = rcode = EXIT_SUCCESS;
3544 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3547 if (G.run_list_level == 1 && G_interactive_fd) {
3548 /* Waits for completion, then fg's main shell */
3549 rcode = checkjobs_and_fg_shell(pi);
3550 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3551 check_and_run_traps(0);
3554 { /* This one just waits for completion */
3555 rcode = checkjobs(pi);
3556 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3557 check_and_run_traps(0);
3559 G.last_exitcode = rcode;
3563 /* Analyze how result affects subsequent commands */
3565 if (rword == RES_IF || rword == RES_ELIF)
3568 #if ENABLE_HUSH_LOOPS
3569 /* Beware of "while false; true; do ..."! */
3570 if (pi->next && pi->next->res_word == RES_DO) {
3571 if (rword == RES_WHILE) {
3573 /* "while false; do...done" - exitcode 0 */
3574 G.last_exitcode = rcode = EXIT_SUCCESS;
3575 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3576 goto check_jobs_and_break;
3579 if (rword == RES_UNTIL) {
3581 debug_printf_exec(": until expr is true: breaking\n");
3582 check_jobs_and_break:
3590 check_jobs_and_continue:
3595 //// if (G.ctrl_z_flag) {
3596 //// /* ctrl-Z forked somewhere in the past, we are the child,
3597 //// * and now we completed running the list. Exit. */
3603 //// if (!G.run_list_level && G_interactive_fd) {
3604 //// signal(SIGTSTP, SIG_IGN);
3605 //// signal(SIGINT, SIG_IGN);
3608 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3609 #if ENABLE_HUSH_LOOPS
3614 #if ENABLE_HUSH_CASE
3620 /* Select which version we will use */
3621 static int run_and_free_list(struct pipe *pi)
3624 debug_printf_exec("run_and_free_list entered\n");
3626 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3627 rcode = run_list(pi);
3629 /* free_pipe_list has the side effect of clearing memory.
3630 * In the long run that function can be merged with run_list,
3631 * but doing that now would hobble the debugging effort. */
3632 free_pipe_list(pi, /* indent: */ 0);
3633 debug_printf_exec("run_and_free_list return %d\n", rcode);
3638 static struct pipe *new_pipe(void)
3641 pi = xzalloc(sizeof(struct pipe));
3642 /*pi->followup = 0; - deliberately invalid value */
3643 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3647 /* Command (member of a pipe) is complete. The only possible error here
3648 * is out of memory, in which case xmalloc exits. */
3649 static int done_command(struct parse_context *ctx)
3651 /* The command is really already in the pipe structure, so
3652 * advance the pipe counter and make a new, null command. */
3653 struct pipe *pi = ctx->pipe;
3654 struct command *command = ctx->command;
3657 if (command->group == NULL
3658 && command->argv == NULL
3659 && command->redirects == NULL
3661 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3662 memset(command, 0, sizeof(*command)); /* paranoia */
3663 return pi->num_cmds;
3666 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3667 //debug_print_tree(ctx->list_head, 20);
3669 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3672 /* Only real trickiness here is that the uncommitted
3673 * command structure is not counted in pi->num_cmds. */
3674 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3675 command = &pi->cmds[pi->num_cmds];
3676 memset(command, 0, sizeof(*command));
3678 ctx->command = command;
3679 /* but ctx->pipe and ctx->list_head remain unchanged */
3681 return pi->num_cmds; /* used only for 0/nonzero check */
3684 static void done_pipe(struct parse_context *ctx, pipe_style type)
3688 debug_printf_parse("done_pipe entered, followup %d\n", type);
3689 /* Close previous command */
3690 not_null = done_command(ctx);
3691 ctx->pipe->followup = type;
3693 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3694 ctx->ctx_inverted = 0;
3695 ctx->pipe->res_word = ctx->ctx_res_w;
3698 /* Without this check, even just <enter> on command line generates
3699 * tree of three NOPs (!). Which is harmless but annoying.
3700 * IOW: it is safe to do it unconditionally.
3701 * RES_NONE case is for "for a in; do ..." (empty IN set)
3702 * and other cases to work. */
3705 || ctx->ctx_res_w == RES_FI
3706 || ctx->ctx_res_w == RES_DONE
3707 || ctx->ctx_res_w == RES_FOR
3708 || ctx->ctx_res_w == RES_IN
3709 || ctx->ctx_res_w == RES_ESAC
3713 debug_printf_parse("done_pipe: adding new pipe: "
3714 "not_null:%d ctx->ctx_res_w:%d\n",
3715 not_null, ctx->ctx_res_w);
3717 ctx->pipe->next = new_p;
3719 /* RES_THEN, RES_DO etc are "sticky" -
3720 * they remain set for commands inside if/while.
3721 * This is used to control execution.
3722 * RES_FOR and RES_IN are NOT sticky (needed to support
3723 * cases where variable or value happens to match a keyword):
3725 #if ENABLE_HUSH_LOOPS
3726 if (ctx->ctx_res_w == RES_FOR
3727 || ctx->ctx_res_w == RES_IN)
3728 ctx->ctx_res_w = RES_NONE;
3730 #if ENABLE_HUSH_CASE
3731 if (ctx->ctx_res_w == RES_MATCH)
3732 ctx->ctx_res_w = RES_CASEI;
3734 ctx->command = NULL; /* trick done_command below */
3735 /* Create the memory for command, roughly:
3736 * ctx->pipe->cmds = new struct command;
3737 * ctx->command = &ctx->pipe->cmds[0];
3740 //debug_print_tree(ctx->list_head, 10);
3742 debug_printf_parse("done_pipe return\n");
3745 static void initialize_context(struct parse_context *ctx)
3747 memset(ctx, 0, sizeof(*ctx));
3748 ctx->pipe = ctx->list_head = new_pipe();
3749 /* Create the memory for command, roughly:
3750 * ctx->pipe->cmds = new struct command;
3751 * ctx->command = &ctx->pipe->cmds[0];
3756 /* If a reserved word is found and processed, parse context is modified
3757 * and 1 is returned.
3760 struct reserved_combo {
3763 unsigned char assignment_flag;
3767 FLAG_END = (1 << RES_NONE ),
3769 FLAG_IF = (1 << RES_IF ),
3770 FLAG_THEN = (1 << RES_THEN ),
3771 FLAG_ELIF = (1 << RES_ELIF ),
3772 FLAG_ELSE = (1 << RES_ELSE ),
3773 FLAG_FI = (1 << RES_FI ),
3775 #if ENABLE_HUSH_LOOPS
3776 FLAG_FOR = (1 << RES_FOR ),
3777 FLAG_WHILE = (1 << RES_WHILE),
3778 FLAG_UNTIL = (1 << RES_UNTIL),
3779 FLAG_DO = (1 << RES_DO ),
3780 FLAG_DONE = (1 << RES_DONE ),
3781 FLAG_IN = (1 << RES_IN ),
3783 #if ENABLE_HUSH_CASE
3784 FLAG_MATCH = (1 << RES_MATCH),
3785 FLAG_ESAC = (1 << RES_ESAC ),
3787 FLAG_START = (1 << RES_XXXX ),
3790 static const struct reserved_combo* match_reserved_word(o_string *word)
3792 /* Mostly a list of accepted follow-up reserved words.
3793 * FLAG_END means we are done with the sequence, and are ready
3794 * to turn the compound list into a command.
3795 * FLAG_START means the word must start a new compound list.
3797 static const struct reserved_combo reserved_list[] = {
3799 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3800 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3801 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3802 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3803 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3804 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3806 #if ENABLE_HUSH_LOOPS
3807 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3808 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3809 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3810 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3811 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3812 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3814 #if ENABLE_HUSH_CASE
3815 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3816 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3819 const struct reserved_combo *r;
3821 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3822 if (strcmp(word->data, r->literal) == 0)
3827 static int reserved_word(o_string *word, struct parse_context *ctx)
3829 #if ENABLE_HUSH_CASE
3830 static const struct reserved_combo reserved_match = {
3831 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3834 const struct reserved_combo *r;
3836 r = match_reserved_word(word);
3840 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3841 #if ENABLE_HUSH_CASE
3842 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3843 /* "case word IN ..." - IN part starts first match part */
3844 r = &reserved_match;
3847 if (r->flag == 0) { /* '!' */
3848 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3849 syntax("! ! command");
3850 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3852 ctx->ctx_inverted = 1;
3855 if (r->flag & FLAG_START) {
3856 struct parse_context *old;
3857 old = xmalloc(sizeof(*old));
3858 debug_printf_parse("push stack %p\n", old);
3859 *old = *ctx; /* physical copy */
3860 initialize_context(ctx);
3862 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3864 ctx->ctx_res_w = RES_SNTX;
3867 ctx->ctx_res_w = r->res;
3868 ctx->old_flag = r->flag;
3869 if (ctx->old_flag & FLAG_END) {
3870 struct parse_context *old;
3871 done_pipe(ctx, PIPE_SEQ);
3872 debug_printf_parse("pop stack %p\n", ctx->stack);
3874 old->command->group = ctx->list_head;
3875 old->command->grp_type = GRP_NORMAL;
3877 o_addstr(&old->as_string, ctx->as_string.data);
3878 o_free_unsafe(&ctx->as_string);
3879 old->command->group_as_string = xstrdup(old->as_string.data);
3880 debug_printf_parse("pop, remembering as:'%s'\n",
3881 old->command->group_as_string);
3883 *ctx = *old; /* physical copy */
3886 word->o_assignment = r->assignment_flag;
3891 /* Word is complete, look at it and update parsing context.
3892 * Normal return is 0. Syntax errors return 1.
3893 * Note: on return, word is reset, but not o_free'd!
3895 static int done_word(o_string *word, struct parse_context *ctx)
3897 struct command *command = ctx->command;
3899 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3900 if (word->length == 0 && word->o_quoted == 0) {
3901 debug_printf_parse("done_word return 0: true null, ignored\n");
3904 /* If this word wasn't an assignment, next ones definitely
3905 * can't be assignments. Even if they look like ones. */
3906 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3907 && word->o_assignment != WORD_IS_KEYWORD
3909 word->o_assignment = NOT_ASSIGNMENT;
3911 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3912 command->assignment_cnt++;
3913 word->o_assignment = MAYBE_ASSIGNMENT;
3916 if (ctx->pending_redirect) {
3917 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3918 * only if run as "bash", not "sh" */
3919 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3921 * ...the word that follows the redirection operator
3922 * shall be subjected to tilde expansion, parameter expansion,
3923 * command substitution, arithmetic expansion, and quote
3924 * removal. Pathname expansion shall not be performed
3925 * on the word by a non-interactive shell; an interactive
3926 * shell may perform it, but shall do so only when
3927 * the expansion would result in one word."
3929 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3930 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3933 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3935 word->o_assignment = NOT_ASSIGNMENT;
3936 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3938 /* "{ echo foo; } echo bar" - bad */
3939 /* NB: bash allows e.g.:
3940 * if true; then { echo foo; } fi
3941 * while if false; then false; fi do break; done
3943 * while if false; then false; fi; do; break; done
3945 if (command->group) {
3947 debug_printf_parse("done_word return 1: syntax error, "
3948 "groups and arglists don't mix\n");
3952 #if ENABLE_HUSH_CASE
3953 if (ctx->ctx_dsemicolon
3954 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3956 /* already done when ctx_dsemicolon was set to 1: */
3957 /* ctx->ctx_res_w = RES_MATCH; */
3958 ctx->ctx_dsemicolon = 0;
3961 if (!command->argv /* if it's the first word... */
3962 #if ENABLE_HUSH_LOOPS
3963 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3964 && ctx->ctx_res_w != RES_IN
3967 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3968 if (reserved_word(word, ctx)) {
3970 debug_printf_parse("done_word return %d\n",
3971 (ctx->ctx_res_w == RES_SNTX));
3972 return (ctx->ctx_res_w == RES_SNTX);
3976 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
3977 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3978 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3979 /* (otherwise it's known to be not empty and is already safe) */
3981 /* exclude "$@" - it can expand to no word despite "" */
3982 char *p = word->data;
3983 while (p[0] == SPECIAL_VAR_SYMBOL
3984 && (p[1] & 0x7f) == '@'
3985 && p[2] == SPECIAL_VAR_SYMBOL
3989 if (p == word->data || p[0] != '\0') {
3990 /* saw no "$@", or not only "$@" but some
3991 * real text is there too */
3992 /* insert "empty variable" reference, this makes
3993 * e.g. "", $empty"" etc to not disappear */
3994 o_addchr(word, SPECIAL_VAR_SYMBOL);
3995 o_addchr(word, SPECIAL_VAR_SYMBOL);
3998 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3999 debug_print_strings("word appended to argv", command->argv);
4003 ctx->pending_redirect = NULL;
4005 #if ENABLE_HUSH_LOOPS
4006 /* Force FOR to have just one word (variable name) */
4007 /* NB: basically, this makes hush see "for v in ..." syntax as if
4008 * as it is "for v; in ...". FOR and IN become two pipe structs
4010 if (ctx->ctx_res_w == RES_FOR) {
4011 //TODO: check that command->argv[0] is a valid variable name!
4012 done_pipe(ctx, PIPE_SEQ);
4015 #if ENABLE_HUSH_CASE
4016 /* Force CASE to have just one word */
4017 if (ctx->ctx_res_w == RES_CASE) {
4018 done_pipe(ctx, PIPE_SEQ);
4021 debug_printf_parse("done_word return 0\n");
4026 /* Peek ahead in the input to find out if we have a "&n" construct,
4027 * as in "2>&1", that represents duplicating a file descriptor.
4028 * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
4029 * -2 (syntax error), -1 if no & was seen, or the number found.
4032 #define redirect_dup_num(as_string, input) \
4033 redirect_dup_num(input)
4035 static int redirect_dup_num(o_string *as_string, struct in_str *input)
4043 ch = i_getch(input); /* get the & */
4044 nommu_addchr(as_string, ch);
4047 ch = i_getch(input);
4048 nommu_addchr(as_string, ch);
4049 return REDIRFD_CLOSE;
4053 while (ch != EOF && isdigit(ch)) {
4054 d = d*10 + (ch-'0');
4056 ch = i_getch(input);
4057 nommu_addchr(as_string, ch);
4062 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4064 bb_error_msg("ambiguous redirect");
4068 /* Return code is 0 normally, 1 if a syntax error is detected
4070 static int parse_redirect(struct parse_context *ctx,
4073 struct in_str *input)
4075 struct command *command = ctx->command;
4076 struct redir_struct *redir;
4077 struct redir_struct **redirp;
4081 if (style != REDIRECT_HEREDOC) {
4082 /* Check for a '2>&1' type redirect */
4083 dup_num = redirect_dup_num(&ctx->as_string, input);
4085 return 1; /* syntax error */
4087 int ch = i_peek(input);
4088 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4089 if (dup_num) { /* <<-... */
4090 ch = i_getch(input);
4091 nommu_addchr(&ctx->as_string, ch);
4094 /* <<[-] word is the same as <<[-]word */
4095 while (ch == ' ' || ch == '\t') {
4096 ch = i_getch(input);
4097 nommu_addchr(&ctx->as_string, ch);
4102 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
4103 int ch = i_peek(input);
4105 /* >|FILE redirect ("clobbering" >).
4106 * Since we do not support "set -o noclobber" yet,
4107 * >| and > are the same for now. Just eat |.
4109 ch = i_getch(input);
4110 nommu_addchr(&ctx->as_string, ch);
4114 /* Create a new redir_struct and append it to the linked list */
4115 redirp = &command->redirects;
4116 while ((redir = *redirp) != NULL) {
4117 redirp = &(redir->next);
4119 *redirp = redir = xzalloc(sizeof(*redir));
4120 /* redir->next = NULL; */
4121 /* redir->rd_filename = NULL; */
4122 redir->rd_type = style;
4123 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4125 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4126 redir_table[style].descrip);
4128 redir->rd_dup = dup_num;
4129 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4130 /* Erik had a check here that the file descriptor in question
4131 * is legit; I postpone that to "run time"
4132 * A "-" representation of "close me" shows up as a -3 here */
4133 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4134 redir->rd_fd, redir->rd_dup);
4136 /* Set ctx->pending_redirect, so we know what to do at the
4137 * end of the next parsed word. */
4138 ctx->pending_redirect = redir;
4143 /* If a redirect is immediately preceded by a number, that number is
4144 * supposed to tell which file descriptor to redirect. This routine
4145 * looks for such preceding numbers. In an ideal world this routine
4146 * needs to handle all the following classes of redirects...
4147 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4148 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4149 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4150 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4152 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4154 * ... If n is quoted, the number shall not be recognized as part of
4155 * the redirection expression. For example:
4157 * writes the character 2 into file a"
4158 * We are getting it right by setting ->o_quoted on any \<char>
4160 * A -1 return means no valid number was found,
4161 * the caller should use the appropriate default for this redirection.
4163 static int redirect_opt_num(o_string *o)
4167 if (o->data == NULL)
4169 num = bb_strtou(o->data, NULL, 10);
4170 if (errno || num < 0)
4177 #define fetch_till_str(as_string, input, word, skip_tabs) \
4178 fetch_till_str(input, word, skip_tabs)
4180 static char *fetch_till_str(o_string *as_string,
4181 struct in_str *input,
4185 o_string heredoc = NULL_O_STRING;
4191 ch = i_getch(input);
4192 nommu_addchr(as_string, ch);
4194 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4195 heredoc.data[past_EOL] = '\0';
4196 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4197 return heredoc.data;
4200 o_addchr(&heredoc, ch);
4201 past_EOL = heredoc.length;
4204 ch = i_getch(input);
4205 nommu_addchr(as_string, ch);
4206 } while (skip_tabs && ch == '\t');
4207 } while (ch == '\n');
4210 o_free_unsafe(&heredoc);
4213 o_addchr(&heredoc, ch);
4214 nommu_addchr(as_string, ch);
4218 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4219 * and load them all. There should be exactly heredoc_cnt of them.
4221 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4223 struct pipe *pi = ctx->list_head;
4227 struct command *cmd = pi->cmds;
4229 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4231 cmd->argv ? cmd->argv[0] : "NONE");
4232 for (i = 0; i < pi->num_cmds; i++) {
4233 struct redir_struct *redir = cmd->redirects;
4235 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4236 i, cmd->argv ? cmd->argv[0] : "NONE");
4238 if (redir->rd_type == REDIRECT_HEREDOC) {
4241 if (heredoc_cnt <= 0) {
4242 syntax("heredoc BUG 1");
4243 return 1; /* error */
4245 redir->rd_type = REDIRECT_HEREDOC2;
4246 /* redir->dup is (ab)used to indicate <<- */
4247 p = fetch_till_str(&ctx->as_string, input,
4248 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4250 syntax("unexpected EOF in here document");
4253 free(redir->rd_filename);
4254 redir->rd_filename = p;
4257 redir = redir->next;
4263 /* Should be 0. If it isn't, it's a parse error */
4265 syntax("heredoc BUG 2");
4271 #define parse_stream(pstring, input, end_trigger) \
4272 parse_stream(input, end_trigger)
4274 static struct pipe *parse_stream(char **pstring,
4275 struct in_str *input,
4277 static void parse_and_run_string(const char *s);
4279 #if ENABLE_HUSH_TICK
4280 static FILE *generate_stream_from_string(const char *s)
4283 int pid, channel[2];
4286 pid = BB_MMU ? fork() : vfork();
4288 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4290 if (pid == 0) { /* child */
4291 disable_restore_tty_pgrp_on_exit();
4292 /* Process substitution is not considered to be usual
4293 * 'command execution'.
4294 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4301 close(channel[0]); /* NB: close _first_, then move fd! */
4302 xmove_fd(channel[1], 1);
4303 /* Prevent it from trying to handle ctrl-z etc */
4304 USE_HUSH_JOB(G.run_list_level = 1;)
4306 reset_traps_to_defaults();
4307 parse_and_run_string(s);
4308 _exit(G.last_exitcode);
4310 /* We re-execute after vfork on NOMMU. This makes this script safe:
4311 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4312 * huge=`cat BIG` # was blocking here forever
4315 re_execute_shell(s, 0);
4320 enable_restore_tty_pgrp_on_exit();
4321 clean_up_after_re_execute();
4323 pf = fdopen(channel[0], "r");
4327 /* Return code is exit status of the process that is run. */
4328 static int process_command_subs(o_string *dest, const char *s)
4331 struct in_str pipe_str;
4334 pf = generate_stream_from_string(s);
4337 close_on_exec_on(fileno(pf));
4339 /* Now send results of command back into original context */
4340 setup_file_in_str(&pipe_str, pf);
4342 while ((ch = i_getch(&pipe_str)) != EOF) {
4348 o_addchr(dest, '\n');
4351 o_addQchr(dest, ch);
4354 debug_printf("done reading from pipe, pclose()ing\n");
4355 /* Note: we got EOF, and we just close the read end of the pipe.
4356 * We do not wait for the `cmd` child to terminate. bash and ash do.
4358 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4359 * `false`; echo $? - bash outputs "1"
4362 debug_printf("closed FILE from child. return 0\n");
4367 static int parse_group(o_string *dest, struct parse_context *ctx,
4368 struct in_str *input, int ch)
4370 /* dest contains characters seen prior to ( or {.
4371 * Typically it's empty, but for function defs,
4372 * it contains function name (without '()'). */
4373 struct pipe *pipe_list;
4375 struct command *command = ctx->command;
4377 debug_printf_parse("parse_group entered\n");
4378 #if ENABLE_HUSH_FUNCTIONS
4379 if (ch == 'F') { /* function definition? */
4380 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4381 //command->fname = dest->data;
4382 command->grp_type = GRP_FUNCTION;
4383 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4384 memset(dest, 0, sizeof(*dest));
4387 if (command->argv /* word [word](... */
4388 || dest->length /* word(... */
4389 || dest->o_quoted /* ""(... */
4392 debug_printf_parse("parse_group return 1: "
4393 "syntax error, groups and arglists don't mix\n");
4399 command->grp_type = GRP_SUBSHELL;
4403 char *as_string = NULL;
4405 pipe_list = parse_stream(&as_string, input, endch);
4408 o_addstr(&ctx->as_string, as_string);
4410 /* empty ()/{} or parse error? */
4411 if (!pipe_list || pipe_list == ERR_PTR) {
4416 debug_printf_parse("parse_group return 1: "
4417 "parse_stream returned %p\n", pipe_list);
4420 command->group = pipe_list;
4422 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4423 command->group_as_string = as_string;
4424 debug_printf_parse("end of group, remembering as:'%s'\n",
4425 command->group_as_string);
4428 debug_printf_parse("parse_group return 0\n");
4430 /* command remains "open", available for possible redirects */
4433 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4434 /* Subroutines for copying $(...) and `...` things */
4435 static int add_till_backquote(o_string *dest, struct in_str *input);
4437 static int add_till_single_quote(o_string *dest, struct in_str *input)
4440 int ch = i_getch(input);
4442 syntax("unterminated '");
4450 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4451 static int add_till_double_quote(o_string *dest, struct in_str *input)
4454 int ch = i_getch(input);
4456 syntax("unterminated \"");
4461 if (ch == '\\') { /* \x. Copy both chars. */
4463 ch = i_getch(input);
4467 if (add_till_backquote(dest, input))
4472 //if (ch == '$') ...
4475 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4477 * "Within the backquoted style of command substitution, backslash
4478 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4479 * The search for the matching backquote shall be satisfied by the first
4480 * backquote found without a preceding backslash; during this search,
4481 * if a non-escaped backquote is encountered within a shell comment,
4482 * a here-document, an embedded command substitution of the $(command)
4483 * form, or a quoted string, undefined results occur. A single-quoted
4484 * or double-quoted string that begins, but does not end, within the
4485 * "`...`" sequence produces undefined results."
4487 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4489 static int add_till_backquote(o_string *dest, struct in_str *input)
4492 int ch = i_getch(input);
4494 syntax("unterminated `");
4500 /* \x. Copy both chars unless it is \` */
4501 int ch2 = i_getch(input);
4503 syntax("unterminated `");
4506 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4513 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4514 * quoting and nested ()s.
4515 * "With the $(command) style of command substitution, all characters
4516 * following the open parenthesis to the matching closing parenthesis
4517 * constitute the command. Any valid shell script can be used for command,
4518 * except a script consisting solely of redirections which produces
4519 * unspecified results."
4521 * echo $(echo '(TEST)' BEST) (TEST) BEST
4522 * echo $(echo 'TEST)' BEST) TEST) BEST
4523 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4525 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4529 int ch = i_getch(input);
4531 syntax("unterminated )");
4540 if (i_peek(input) == ')') {
4548 if (add_till_single_quote(dest, input))
4554 if (add_till_double_quote(dest, input))
4560 /* \x. Copy verbatim. Important for \(, \) */
4561 ch = i_getch(input);
4563 syntax("unterminated )");
4572 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4574 /* Return code: 0 for OK, 1 for syntax error */
4576 #define handle_dollar(as_string, dest, input) \
4577 handle_dollar(dest, input)
4579 static int handle_dollar(o_string *as_string,
4581 struct in_str *input)
4584 int ch = i_peek(input); /* first character after the $ */
4585 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4587 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4589 ch = i_getch(input);
4590 nommu_addchr(as_string, ch);
4592 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4594 debug_printf_parse(": '%c'\n", ch);
4595 o_addchr(dest, ch | quote_mask);
4598 if (!isalnum(ch) && ch != '_')
4600 ch = i_getch(input);
4601 nommu_addchr(as_string, ch);
4603 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4604 } else if (isdigit(ch)) {
4606 ch = i_getch(input);
4607 nommu_addchr(as_string, ch);
4608 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4609 debug_printf_parse(": '%c'\n", ch);
4610 o_addchr(dest, ch | quote_mask);
4611 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4612 } else switch (ch) {
4614 case '!': /* last bg pid */
4615 case '?': /* last exit code */
4616 case '#': /* number of args */
4617 case '*': /* args */
4618 case '@': /* args */
4619 goto make_one_char_var;
4621 bool first_char, all_digits;
4623 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4624 ch = i_getch(input);
4625 nommu_addchr(as_string, ch);
4626 /* XXX maybe someone will try to escape the '}' */
4631 ch = i_getch(input);
4632 nommu_addchr(as_string, ch);
4638 /* ${#var}: length of var contents */
4640 else if (isdigit(ch)) {
4647 && ( (all_digits && !isdigit(ch))
4648 || (!all_digits && !isalnum(ch) && ch != '_')
4651 /* handle parameter expansions
4652 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4657 case ':': /* null modifier */
4658 if (expansion == 0) {
4659 debug_printf_parse(": null modifier\n");
4664 case '#': /* remove prefix */
4665 case '%': /* remove suffix */
4666 if (expansion == 0) {
4667 debug_printf_parse(": remove suffix/prefix\n");
4672 case '-': /* default value */
4673 case '=': /* assign default */
4674 case '+': /* alternative */
4675 case '?': /* error indicate */
4676 debug_printf_parse(": parameter expansion\n");
4681 syntax("unterminated ${name}");
4682 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4687 debug_printf_parse(": '%c'\n", ch);
4688 o_addchr(dest, ch | quote_mask);
4692 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4695 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4700 ch = i_getch(input);
4701 nommu_addchr(as_string, ch);
4702 # if ENABLE_SH_MATH_SUPPORT
4703 if (i_peek(input) == '(') {
4704 ch = i_getch(input);
4705 nommu_addchr(as_string, ch);
4706 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4707 o_addchr(dest, /*quote_mask |*/ '+');
4711 if (add_till_closing_paren(dest, input, true))
4715 o_addstr(as_string, dest->data + pos);
4716 o_addchr(as_string, ')');
4717 o_addchr(as_string, ')');
4720 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4724 # if ENABLE_HUSH_TICK
4725 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4726 o_addchr(dest, quote_mask | '`');
4730 if (add_till_closing_paren(dest, input, false))
4734 o_addstr(as_string, dest->data + pos);
4735 o_addchr(as_string, '`');
4738 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4744 ch = i_getch(input);
4745 nommu_addchr(as_string, ch);
4747 if (isalnum(ch)) { /* it's $_name or $_123 */
4753 /* $_ Shell or shell script name; or last cmd name */
4754 /* $- Option flags set by set builtin or shell options (-i etc) */
4756 o_addQchr(dest, '$');
4758 debug_printf_parse("handle_dollar return 0\n");
4763 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4764 parse_stream_dquoted(dest, input, dquote_end)
4766 static int parse_stream_dquoted(o_string *as_string,
4768 struct in_str *input,
4775 ch = i_getch(input);
4777 nommu_addchr(as_string, ch);
4778 if (ch == dquote_end) { /* may be only '"' or EOF */
4779 if (dest->o_assignment == NOT_ASSIGNMENT)
4780 dest->o_escape ^= 1;
4781 debug_printf_parse("parse_stream_dquoted return 0\n");
4784 /* note: can't move it above ch == dquote_end check! */
4786 syntax("unterminated \"");
4787 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4792 next = i_peek(input);
4794 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4795 ch, ch, dest->o_escape);
4799 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4803 * "The backslash retains its special meaning [in "..."]
4804 * only when followed by one of the following characters:
4805 * $, `, ", \, or <newline>. A double quote may be quoted
4806 * within double quotes by preceding it with a backslash.
4807 * If enabled, history expansion will be performed unless
4808 * an ! appearing in double quotes is escaped using
4809 * a backslash. The backslash preceding the ! is not removed."
4811 if (strchr("$`\"\\", next) != NULL) {
4812 o_addqchr(dest, i_getch(input));
4814 o_addqchr(dest, '\\');
4819 if (handle_dollar(as_string, dest, input) != 0) {
4820 debug_printf_parse("parse_stream_dquoted return 1: "
4821 "handle_dollar returned non-0\n");
4826 #if ENABLE_HUSH_TICK
4828 //int pos = dest->length;
4829 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4830 o_addchr(dest, 0x80 | '`');
4831 if (add_till_backquote(dest, input))
4833 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4834 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4838 o_addQchr(dest, ch);
4840 && (dest->o_assignment == MAYBE_ASSIGNMENT
4841 || dest->o_assignment == WORD_IS_KEYWORD)
4842 && is_assignment(dest->data)
4844 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4850 * Scan input until EOF or end_trigger char.
4851 * Return a list of pipes to execute, or NULL on EOF
4852 * or if end_trigger character is met.
4853 * On syntax error, exit is shell is not interactive,
4854 * reset parsing machinery and start parsing anew,
4855 * or return ERR_PTR.
4857 static struct pipe *parse_stream(char **pstring,
4858 struct in_str *input,
4861 struct parse_context ctx;
4862 o_string dest = NULL_O_STRING;
4866 /* Double-quote state is handled in the state variable is_in_dquote.
4867 * A single-quote triggers a bypass of the main loop until its mate is
4868 * found. When recursing, quote state is passed in via dest->o_escape.
4870 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4871 end_trigger ? : 'X');
4873 G.ifs = get_local_var_value("IFS");
4878 #if ENABLE_HUSH_INTERACTIVE
4879 input->promptmode = 0; /* PS1 */
4881 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4882 initialize_context(&ctx);
4887 const char *is_special;
4891 redir_type redir_style;
4894 /* dest.o_quoted = 1; - already is (see below) */
4895 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4898 /* We reached closing '"' */
4901 ch = i_getch(input);
4902 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4903 ch, ch, dest.o_escape);
4908 syntax("unterminated here document");
4911 if (done_word(&dest, &ctx)) {
4915 done_pipe(&ctx, PIPE_SEQ);
4917 /* If we got nothing... */
4918 // TODO: test script consisting of just "&"
4919 if (pi->num_cmds == 0
4920 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4922 free_pipe_list(pi, 0);
4925 debug_printf_parse("parse_stream return %p\n", pi);
4927 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4929 *pstring = ctx.as_string.data;
4931 o_free_unsafe(&ctx.as_string);
4935 nommu_addchr(&ctx.as_string, ch);
4936 is_ifs = strchr(G.ifs, ch);
4937 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4938 "\\$\"" USE_HUSH_TICK("`") /* always special */
4941 if (!is_special && !is_ifs) { /* ordinary char */
4942 o_addQchr(&dest, ch);
4943 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4944 || dest.o_assignment == WORD_IS_KEYWORD)
4946 && is_assignment(dest.data)
4948 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4954 if (done_word(&dest, &ctx)) {
4958 #if ENABLE_HUSH_CASE
4959 /* "case ... in <newline> word) ..." -
4960 * newlines are ignored (but ';' wouldn't be) */
4961 if (ctx.command->argv == NULL
4962 && ctx.ctx_res_w == RES_MATCH
4967 /* Treat newline as a command separator. */
4968 done_pipe(&ctx, PIPE_SEQ);
4969 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4971 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4976 dest.o_assignment = MAYBE_ASSIGNMENT;
4978 /* note: if (is_ifs) continue;
4979 * will still trigger for us */
4982 if (end_trigger && end_trigger == ch
4983 && (heredoc_cnt == 0 || end_trigger != ';')
4985 //TODO: disallow "{ cmd }" without semicolon
4987 /* This is technically valid:
4988 * { cat <<HERE; }; echo Ok
4993 * but we don't support this.
4994 * We require heredoc to be in enclosing {}/(),
4997 syntax("unterminated here document");
5000 if (done_word(&dest, &ctx)) {
5003 done_pipe(&ctx, PIPE_SEQ);
5004 dest.o_assignment = MAYBE_ASSIGNMENT;
5005 /* Do we sit outside of any if's, loops or case's? */
5007 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5009 debug_printf_parse("parse_stream return %p: "
5010 "end_trigger char found\n",
5014 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5016 *pstring = ctx.as_string.data;
5018 o_free_unsafe(&ctx.as_string);
5020 return ctx.list_head;
5026 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
5027 /* ch is a special char and thus this word
5028 * cannot be an assignment */
5029 dest.o_assignment = NOT_ASSIGNMENT;
5034 next = i_peek(input);
5039 if (dest.length == 0) {
5042 if (ch == EOF || ch == '\n')
5045 /* note: we do not add it to &ctx.as_string */
5047 nommu_addchr(&ctx.as_string, '\n');
5049 o_addQchr(&dest, ch);
5057 o_addchr(&dest, '\\');
5058 ch = i_getch(input);
5059 nommu_addchr(&ctx.as_string, ch);
5060 o_addchr(&dest, ch);
5061 /* Example: echo Hello \2>file
5062 * we need to know that word 2 is quoted */
5066 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5067 debug_printf_parse("parse_stream parse error: "
5068 "handle_dollar returned non-0\n");
5075 ch = i_getch(input);
5077 syntax("unterminated '");
5080 nommu_addchr(&ctx.as_string, ch);
5083 if (dest.o_assignment == NOT_ASSIGNMENT)
5084 o_addqchr(&dest, ch);
5086 o_addchr(&dest, ch);
5091 is_in_dquote ^= 1; /* invert */
5092 if (dest.o_assignment == NOT_ASSIGNMENT)
5095 #if ENABLE_HUSH_TICK
5100 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5101 o_addchr(&dest, '`');
5105 if (add_till_backquote(&dest, input))
5108 o_addstr(&ctx.as_string, dest.data + pos);
5109 o_addchr(&ctx.as_string, '`');
5111 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5112 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5117 redir_fd = redirect_opt_num(&dest);
5118 if (done_word(&dest, &ctx)) {
5121 redir_style = REDIRECT_OVERWRITE;
5123 redir_style = REDIRECT_APPEND;
5124 ch = i_getch(input);
5125 nommu_addchr(&ctx.as_string, ch);
5128 else if (next == '(') {
5129 syntax(">(process) not supported");
5133 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5137 redir_fd = redirect_opt_num(&dest);
5138 if (done_word(&dest, &ctx)) {
5141 redir_style = REDIRECT_INPUT;
5143 redir_style = REDIRECT_HEREDOC;
5145 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5146 ch = i_getch(input);
5147 nommu_addchr(&ctx.as_string, ch);
5148 } else if (next == '>') {
5149 redir_style = REDIRECT_IO;
5150 ch = i_getch(input);
5151 nommu_addchr(&ctx.as_string, ch);
5154 else if (next == '(') {
5155 syntax("<(process) not supported");
5159 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5163 #if ENABLE_HUSH_CASE
5166 if (done_word(&dest, &ctx)) {
5169 done_pipe(&ctx, PIPE_SEQ);
5170 #if ENABLE_HUSH_CASE
5171 /* Eat multiple semicolons, detect
5172 * whether it means something special */
5177 ch = i_getch(input);
5178 nommu_addchr(&ctx.as_string, ch);
5179 if (ctx.ctx_res_w == RES_CASEI) {
5180 ctx.ctx_dsemicolon = 1;
5181 ctx.ctx_res_w = RES_MATCH;
5187 /* We just finished a cmd. New one may start
5188 * with an assignment */
5189 dest.o_assignment = MAYBE_ASSIGNMENT;
5192 if (done_word(&dest, &ctx)) {
5196 ch = i_getch(input);
5197 nommu_addchr(&ctx.as_string, ch);
5198 done_pipe(&ctx, PIPE_AND);
5200 done_pipe(&ctx, PIPE_BG);
5204 if (done_word(&dest, &ctx)) {
5207 #if ENABLE_HUSH_CASE
5208 if (ctx.ctx_res_w == RES_MATCH)
5209 break; /* we are in case's "word | word)" */
5211 if (next == '|') { /* || */
5212 ch = i_getch(input);
5213 nommu_addchr(&ctx.as_string, ch);
5214 done_pipe(&ctx, PIPE_OR);
5216 /* we could pick up a file descriptor choice here
5217 * with redirect_opt_num(), but bash doesn't do it.
5218 * "echo foo 2| cat" yields "foo 2". */
5223 #if ENABLE_HUSH_CASE
5224 /* "case... in [(]word)..." - skip '(' */
5225 if (ctx.ctx_res_w == RES_MATCH
5226 && ctx.command->argv == NULL /* not (word|(... */
5227 && dest.length == 0 /* not word(... */
5228 && dest.o_quoted == 0 /* not ""(... */
5233 #if ENABLE_HUSH_FUNCTIONS
5234 if (dest.length != 0 /* not just () but word() */
5235 && dest.o_quoted == 0 /* not a"b"c() */
5236 && ctx.command->argv == NULL /* it's the first word */
5237 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5238 && i_peek(input) == ')'
5239 && !match_reserved_word(&dest)
5241 bb_error_msg("seems like a function definition");
5243 //if !BB_MMU o_addchr(&ctx.as_string...
5245 //TODO: do it properly.
5246 ch = i_getch(input);
5247 } while (ch == ' ' || ch == '\n');
5249 syntax("was expecting {");
5252 ch = 'F'; /* magic value */
5256 if (parse_group(&dest, &ctx, input, ch) != 0) {
5261 #if ENABLE_HUSH_CASE
5262 if (ctx.ctx_res_w == RES_MATCH)
5266 /* proper use of this character is caught by end_trigger:
5267 * if we see {, we call parse_group(..., end_trigger='}')
5268 * and it will match } earlier (not here). */
5269 syntax("unexpected } or )");
5273 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5279 struct parse_context *pctx;
5280 IF_HAS_KEYWORDS(struct parse_context *p2;)
5282 /* Clean up allocated tree.
5283 * Samples for finding leaks on syntax error recovery path.
5284 * Run them from interactive shell, watch pmap `pidof hush`.
5285 * while if false; then false; fi do break; done
5287 * while if false; then false; fi; do break; fi
5288 * Samples to catch leaks at execution:
5289 * while if (true | {true;}); then echo ok; fi; do break; done
5290 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5294 /* Update pipe/command counts,
5295 * otherwise freeing may miss some */
5296 done_pipe(pctx, PIPE_SEQ);
5297 debug_printf_clean("freeing list %p from ctx %p\n",
5298 pctx->list_head, pctx);
5299 debug_print_tree(pctx->list_head, 0);
5300 free_pipe_list(pctx->list_head, 0);
5301 debug_printf_clean("freed list %p\n", pctx->list_head);
5303 o_free_unsafe(&pctx->as_string);
5305 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5309 IF_HAS_KEYWORDS(pctx = p2;)
5310 } while (HAS_KEYWORDS && pctx);
5311 /* Free text, clear all dest fields */
5313 /* If we are not in top-level parse, we return,
5314 * our caller will propagate error.
5316 if (end_trigger != ';') {
5323 /* Discard cached input, force prompt */
5325 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5330 /* Executing from string: eval, sh -c '...'
5331 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5332 * end_trigger controls how often we stop parsing
5333 * NUL: parse all, execute, return
5334 * ';': parse till ';' or newline, execute, repeat till EOF
5336 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5339 struct pipe *pipe_list;
5341 pipe_list = parse_stream(NULL, inp, end_trigger);
5342 if (!pipe_list) /* EOF */
5344 debug_print_tree(pipe_list, 0);
5345 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5346 run_and_free_list(pipe_list);
5350 static void parse_and_run_string(const char *s)
5352 struct in_str input;
5353 setup_string_in_str(&input, s);
5354 parse_and_run_stream(&input, '\0');
5357 static void parse_and_run_file(FILE *f)
5359 struct in_str input;
5360 setup_file_in_str(&input, f);
5361 parse_and_run_stream(&input, ';');
5364 /* Called a few times only (or even once if "sh -c") */
5365 static void block_signals(int second_time)
5370 mask = (1 << SIGQUIT);
5371 if (G_interactive_fd) {
5375 //TODO | (1 << SIGHUP)
5377 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5382 G.non_DFL_mask = mask;
5385 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5389 sigaddset(&G.blocked_set, sig);
5393 sigdelset(&G.blocked_set, SIGCHLD);
5395 sigprocmask(SIG_SETMASK, &G.blocked_set,
5396 second_time ? NULL : &G.inherited_set);
5397 /* POSIX allows shell to re-enable SIGCHLD
5398 * even if it was SIG_IGN on entry */
5399 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5401 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5406 static void maybe_set_to_sigexit(int sig)
5408 void (*handler)(int);
5409 /* non_DFL_mask'ed signals are, well, masked,
5410 * no need to set handler for them.
5412 if (!((G.non_DFL_mask >> sig) & 1)) {
5413 handler = signal(sig, sigexit);
5414 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5415 signal(sig, handler);
5418 /* Set handlers to restore tty pgrp and exit */
5419 static void set_fatal_handlers(void)
5421 /* We _must_ restore tty pgrp on fatal signals */
5423 maybe_set_to_sigexit(SIGILL );
5424 maybe_set_to_sigexit(SIGFPE );
5425 maybe_set_to_sigexit(SIGBUS );
5426 maybe_set_to_sigexit(SIGSEGV);
5427 maybe_set_to_sigexit(SIGTRAP);
5428 } /* else: hush is perfect. what SEGV? */
5429 maybe_set_to_sigexit(SIGABRT);
5430 /* bash 3.2 seems to handle these just like 'fatal' ones */
5431 maybe_set_to_sigexit(SIGPIPE);
5432 maybe_set_to_sigexit(SIGALRM);
5433 //TODO: disable and move down when proper SIGHUP handling is added
5434 maybe_set_to_sigexit(SIGHUP );
5435 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5436 * if we aren't interactive... but in this case
5437 * we never want to restore pgrp on exit, and this fn is not called */
5438 /*maybe_set_to_sigexit(SIGTERM);*/
5439 /*maybe_set_to_sigexit(SIGINT );*/
5443 static int set_mode(const char cstate, const char mode)
5445 int state = (cstate == '-' ? 1 : 0);
5447 case 'n': G.fake_mode = state; break;
5448 case 'x': /*G.debug_mode = state;*/ break;
5449 default: return EXIT_FAILURE;
5451 return EXIT_SUCCESS;
5454 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5455 int hush_main(int argc, char **argv)
5457 static const struct variable const_shell_ver = {
5459 .varstr = (char*)hush_version_str,
5460 .max_len = 1, /* 0 can provoke free(name) */
5464 int signal_mask_is_inited = 0;
5467 struct variable *cur_var;
5470 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5471 G.last_exitcode = EXIT_SUCCESS;
5473 G.argv0_for_re_execing = argv[0];
5475 /* Deal with HUSH_VERSION */
5476 G.shell_ver = const_shell_ver; /* copying struct here */
5477 G.top_var = &G.shell_ver;
5478 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5479 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5480 /* Initialize our shell local variables with the values
5481 * currently living in the environment */
5482 cur_var = G.top_var;
5485 char *value = strchr(*e, '=');
5486 if (value) { /* paranoia */
5487 cur_var->next = xzalloc(sizeof(*cur_var));
5488 cur_var = cur_var->next;
5489 cur_var->varstr = *e;
5490 cur_var->max_len = strlen(*e);
5491 cur_var->flg_export = 1;
5495 debug_printf_env("putenv '%s'\n", hush_version_str);
5496 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5497 #if ENABLE_FEATURE_EDITING
5498 G.line_input_state = new_line_input_t(FOR_SHELL);
5500 G.global_argc = argc;
5501 G.global_argv = argv;
5502 /* Initialize some more globals to non-zero values */
5504 #if ENABLE_HUSH_INTERACTIVE
5505 if (ENABLE_FEATURE_EDITING)
5506 cmdedit_set_initial_prompt();
5510 /* Shell is non-interactive at first. We need to call
5511 * block_signals(0) if we are going to execute "sh <script>",
5512 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5513 * If we later decide that we are interactive, we run block_signals(0)
5514 * (or re-run block_signals(1) if we ran block_signals(0) before)
5515 * in order to intercept (more) signals.
5519 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5521 opt = getopt(argc, argv, "c:xins"
5531 G.root_pid = getpid();
5532 G.global_argv = argv + optind;
5533 if (!argv[optind]) {
5534 /* -c 'script' (no params): prevent empty $0 */
5535 *--G.global_argv = argv[0];
5537 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5538 G.global_argc = argc - optind;
5539 block_signals(0); /* 0: called 1st time */
5540 parse_and_run_string(optarg);
5543 /* Well, we cannot just declare interactiveness,
5544 * we have to have some stuff (ctty, etc) */
5545 /* G_interactive_fd++; */
5548 /* "-s" means "read from stdin", but this is how we always
5549 * operate, so simply do nothing here. */
5552 case '<': /* "big heredoc" support */
5553 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5556 G.root_pid = bb_strtou(optarg, &optarg, 16);
5558 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5560 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5561 # if ENABLE_HUSH_LOOPS
5563 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5568 set_local_var(xstrdup(optarg), 0, opt == 'R');
5573 if (!set_mode('-', opt))
5577 fprintf(stderr, "Usage: sh [FILE]...\n"
5578 " or: sh -c command [args]...\n\n");
5584 } /* option parsing loop */
5587 G.root_pid = getpid();
5589 /* If we are login shell... */
5590 if (argv[0] && argv[0][0] == '-') {
5592 /* XXX what should argv be while sourcing /etc/profile? */
5593 debug_printf("sourcing /etc/profile\n");
5594 input = fopen_for_read("/etc/profile");
5595 if (input != NULL) {
5596 close_on_exec_on(fileno(input));
5597 block_signals(0); /* 0: called 1st time */
5598 signal_mask_is_inited = 1;
5599 parse_and_run_file(input);
5602 /* bash: after sourcing /etc/profile,
5603 * tries to source (in the given order):
5604 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5605 * stopping of first found. --noprofile turns this off.
5606 * bash also sources ~/.bash_logout on exit.
5607 * If called as sh, skips .bash_XXX files.
5614 * "bash <script>" (which is never interactive (unless -i?))
5615 * sources $BASH_ENV here (without scanning $PATH).
5616 * If called as sh, does the same but with $ENV.
5618 debug_printf("running script '%s'\n", argv[optind]);
5619 G.global_argv = argv + optind;
5620 G.global_argc = argc - optind;
5621 input = xfopen_for_read(argv[optind]);
5622 close_on_exec_on(fileno(input));
5623 if (!signal_mask_is_inited)
5624 block_signals(0); /* 0: called 1st time */
5625 parse_and_run_file(input);
5626 #if ENABLE_FEATURE_CLEAN_UP
5632 /* Up to here, shell was non-interactive. Now it may become one.
5633 * NB: don't forget to (re)run block_signals(0/1) as needed.
5636 /* A shell is interactive if the '-i' flag was given, or if all of
5637 * the following conditions are met:
5639 * no arguments remaining or the -s flag given
5640 * standard input is a terminal
5641 * standard output is a terminal
5642 * Refer to Posix.2, the description of the 'sh' utility.
5645 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5646 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5647 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5648 //TODO: "interactive" and "have job control" are two different things.
5649 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5650 //should stay on! Currently, we mix these into one.
5651 if (G.saved_tty_pgrp >= 0) {
5652 /* try to dup stdin to high fd#, >= 255 */
5653 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5654 if (G_interactive_fd < 0) {
5655 /* try to dup to any fd */
5656 G_interactive_fd = dup(STDIN_FILENO);
5657 if (G_interactive_fd < 0)
5659 G_interactive_fd = 0;
5661 // TODO: track & disallow any attempts of user
5662 // to (inadvertently) close/redirect it
5665 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5666 if (G_interactive_fd) {
5669 /* We are indeed interactive shell, and we will perform
5670 * job control. Setting up for that. */
5672 close_on_exec_on(G_interactive_fd);
5673 /* If we were run as 'hush &', sleep until we are
5674 * in the foreground (tty pgrp == our pgrp).
5675 * If we get started under a job aware app (like bash),
5676 * make sure we are now in charge so we don't fight over
5677 * who gets the foreground */
5679 shell_pgrp = getpgrp();
5680 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5681 if (G.saved_tty_pgrp == shell_pgrp)
5683 /* send TTIN to ourself (should stop us) */
5684 kill(- shell_pgrp, SIGTTIN);
5686 /* Block some signals */
5687 block_signals(signal_mask_is_inited);
5688 /* Set other signals to restore saved_tty_pgrp */
5689 set_fatal_handlers();
5690 /* Put ourselves in our own process group */
5691 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5692 /* Grab control of the terminal */
5693 tcsetpgrp(G_interactive_fd, getpid());
5694 /* -1 is special - makes xfuncs longjmp, not exit
5695 * (we reset die_sleep = 0 whereever we [v]fork) */
5696 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5697 if (setjmp(die_jmp)) {
5698 /* xfunc has failed! die die die */
5699 /* no EXIT traps, this is an escape hatch! */
5701 hush_exit(xfunc_error_retval);
5703 } else if (!signal_mask_is_inited) {
5704 block_signals(0); /* 0: called 1st time */
5705 } /* else: block_signals(0) was done before */
5706 #elif ENABLE_HUSH_INTERACTIVE
5707 /* No job control compiled in, only prompt/line editing */
5708 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5709 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5710 if (G_interactive_fd < 0) {
5711 /* try to dup to any fd */
5712 G_interactive_fd = dup(STDIN_FILENO);
5713 if (G_interactive_fd < 0)
5715 G_interactive_fd = 0;
5718 if (G_interactive_fd) {
5719 close_on_exec_on(G_interactive_fd);
5720 block_signals(signal_mask_is_inited);
5721 } else if (!signal_mask_is_inited) {
5725 /* We have interactiveness code disabled */
5726 if (!signal_mask_is_inited) {
5731 * if interactive but not a login shell, sources ~/.bashrc
5732 * (--norc turns this off, --rcfile <file> overrides)
5735 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5736 printf("\n\n%s hush - the humble shell\n", bb_banner);
5737 printf("Enter 'help' for a list of built-in commands.\n\n");
5740 parse_and_run_file(stdin);
5743 #if ENABLE_FEATURE_CLEAN_UP
5744 if (G.cwd != bb_msg_unknown)
5746 cur_var = G.top_var->next;
5748 struct variable *tmp = cur_var;
5749 if (!cur_var->max_len)
5750 free(cur_var->varstr);
5751 cur_var = cur_var->next;
5755 hush_exit(G.last_exitcode);
5760 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5761 int lash_main(int argc, char **argv)
5763 //bb_error_msg("lash is deprecated, please use hush instead");
5764 return hush_main(argc, argv);
5772 static int builtin_trap(char **argv)
5779 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5783 /* No args: print all trapped. This isn't 100% correct as we
5784 * should be escaping the cmd so that it can be pasted back in
5786 for (i = 0; i < NSIG; ++i)
5788 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5789 return EXIT_SUCCESS;
5794 /* If first arg is decimal: reset all specified signals */
5795 sig = bb_strtou(*argv, NULL, 10);
5801 sig = get_signum(*argv++);
5802 if (sig < 0 || sig >= NSIG) {
5804 /* Mimic bash message exactly */
5805 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5810 G.traps[sig] = xstrdup(new_cmd);
5812 debug_printf("trap: setting SIG%s (%i) to '%s'",
5813 get_signame(sig), sig, G.traps[sig]);
5815 /* There is no signal for 0 (EXIT) */
5820 sigaddset(&G.blocked_set, sig);
5822 /* There was a trap handler, we are removing it
5823 * (if sig has non-DFL handling,
5824 * we don't need to do anything) */
5825 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5827 sigdelset(&G.blocked_set, sig);
5829 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5834 /* First arg is "-": reset all specified to default */
5835 /* First arg is "": ignore all specified */
5836 /* Everything else: execute first arg upon signal */
5838 bb_error_msg("trap: invalid arguments");
5839 return EXIT_FAILURE;
5841 if (NOT_LONE_DASH(*argv))
5847 static int builtin_true(char **argv UNUSED_PARAM)
5852 static int builtin_test(char **argv)
5859 return test_main(argc, argv - argc);
5862 static int builtin_echo(char **argv)
5869 return echo_main(argc, argv - argc);
5872 static int builtin_eval(char **argv)
5874 int rcode = EXIT_SUCCESS;
5877 char *str = expand_strvec_to_string(argv);
5879 * eval "echo Hi; done" ("done" is syntax error):
5880 * "echo Hi" will not execute too.
5882 parse_and_run_string(str);
5884 rcode = G.last_exitcode;
5889 static int builtin_cd(char **argv)
5891 const char *newdir = argv[1];
5892 if (newdir == NULL) {
5893 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5894 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5896 newdir = getenv("HOME") ? : "/";
5898 if (chdir(newdir)) {
5899 /* Mimic bash message exactly */
5900 bb_perror_msg("cd: %s", newdir);
5901 return EXIT_FAILURE;
5904 return EXIT_SUCCESS;
5907 static int builtin_exec(char **argv)
5909 if (*++argv == NULL)
5910 return EXIT_SUCCESS; /* bash does this */
5915 // FIXME: if exec fails, bash does NOT exit! We do...
5916 pseudo_exec_argv(&dummy, argv, 0, NULL);
5921 static int builtin_exit(char **argv)
5923 debug_printf_exec("%s()\n", __func__);
5924 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5925 //puts("exit"); /* bash does it */
5926 // TODO: warn if we have background jobs: "There are stopped jobs"
5927 // On second consecutive 'exit', exit anyway.
5928 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
5930 /* note: EXIT trap is run by hush_exit */
5931 if (*++argv == NULL)
5932 hush_exit(G.last_exitcode);
5933 /* mimic bash: exit 123abc == exit 255 + error msg */
5934 xfunc_error_retval = 255;
5935 /* bash: exit -2 == exit 254, no error msg */
5936 hush_exit(xatoi(*argv) & 0xff);
5939 static int builtin_export(char **argv)
5941 if (*++argv == NULL) {
5943 // ash emits: export VAR='VAL'
5944 // bash: declare -x VAR="VAL"
5945 // (both also escape as needed (quotes, $, etc))
5950 return EXIT_SUCCESS;
5957 value = strchr(name, '=');
5959 /* They are exporting something without a =VALUE */
5960 struct variable *var;
5962 var = get_local_var(name);
5964 var->flg_export = 1;
5965 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5966 putenv(var->varstr);
5968 /* bash does not return an error when trying to export
5969 * an undefined variable. Do likewise. */
5972 set_local_var(xstrdup(name), 1, 0);
5975 return EXIT_SUCCESS;
5979 /* built-in 'fg' and 'bg' handler */
5980 static int builtin_fg_bg(char **argv)
5985 if (!G_interactive_fd)
5986 return EXIT_FAILURE;
5987 /* If they gave us no args, assume they want the last backgrounded task */
5989 for (pi = G.job_list; pi; pi = pi->next) {
5990 if (pi->jobid == G.last_jobid) {
5994 bb_error_msg("%s: no current job", argv[0]);
5995 return EXIT_FAILURE;
5997 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5998 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5999 return EXIT_FAILURE;
6001 for (pi = G.job_list; pi; pi = pi->next) {
6002 if (pi->jobid == jobnum) {
6006 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6007 return EXIT_FAILURE;
6009 // TODO: bash prints a string representation
6010 // of job being foregrounded (like "sleep 1 | cat")
6011 if (argv[0][0] == 'f') {
6012 /* Put the job into the foreground. */
6013 tcsetpgrp(G_interactive_fd, pi->pgrp);
6016 /* Restart the processes in the job */
6017 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6018 for (i = 0; i < pi->num_cmds; i++) {
6019 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6020 pi->cmds[i].is_stopped = 0;
6022 pi->stopped_cmds = 0;
6024 i = kill(- pi->pgrp, SIGCONT);
6026 if (errno == ESRCH) {
6027 delete_finished_bg_job(pi);
6028 return EXIT_SUCCESS;
6030 bb_perror_msg("kill (SIGCONT)");
6033 if (argv[0][0] == 'f') {
6035 return checkjobs_and_fg_shell(pi);
6037 return EXIT_SUCCESS;
6041 #if ENABLE_HUSH_HELP
6042 static int builtin_help(char **argv UNUSED_PARAM)
6044 const struct built_in_command *x;
6047 "Built-in commands:\n"
6048 "------------------\n");
6049 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6050 printf("%s\t%s\n", x->cmd, x->descr);
6053 return EXIT_SUCCESS;
6058 static int builtin_jobs(char **argv UNUSED_PARAM)
6061 const char *status_string;
6063 for (job = G.job_list; job; job = job->next) {
6064 if (job->alive_cmds == job->stopped_cmds)
6065 status_string = "Stopped";
6067 status_string = "Running";
6069 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6071 return EXIT_SUCCESS;
6076 static int builtin_memleak(char **argv UNUSED_PARAM)
6081 /* Crude attempt to find where "free memory" starts,
6082 * sans fragmentation. */
6084 l = (unsigned long)p;
6087 if (l < (unsigned long)p) l = (unsigned long)p;
6090 if (!G.memleak_value)
6091 G.memleak_value = l;
6093 l -= G.memleak_value;
6100 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6105 static int builtin_pwd(char **argv UNUSED_PARAM)
6108 return EXIT_SUCCESS;
6111 static int builtin_read(char **argv)
6114 const char *name = argv[1] ? argv[1] : "REPLY";
6115 //TODO: check that argv[1] is a valid variable name
6117 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6118 return set_local_var(string, 0, 0);
6121 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6122 * built-in 'set' handler
6124 * set [-abCefhmnuvx] [-o option] [argument...]
6125 * set [+abCefhmnuvx] [+o option] [argument...]
6126 * set -- [argument...]
6129 * Implementations shall support the options in both their hyphen and
6130 * plus-sign forms. These options can also be specified as options to sh.
6132 * Write out all variables and their values: set
6133 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6134 * Turn on the -x and -v options: set -xv
6135 * Unset all positional parameters: set --
6136 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6137 * Set the positional parameters to the expansion of x, even if x expands
6138 * with a leading '-' or '+': set -- $x
6140 * So far, we only support "set -- [argument...]" and some of the short names.
6142 static int builtin_set(char **argv)
6145 char **pp, **g_argv;
6146 char *arg = *++argv;
6150 for (e = G.top_var; e; e = e->next)
6152 return EXIT_SUCCESS;
6156 if (!strcmp(arg, "--")) {
6161 if (arg[0] == '+' || arg[0] == '-') {
6162 for (n = 1; arg[n]; ++n)
6163 if (set_mode(arg[0], arg[n]))
6169 } while ((arg = *++argv) != NULL);
6170 /* Now argv[0] is 1st argument */
6172 /* Only reset global_argv if we didn't process anything */
6174 return EXIT_SUCCESS;
6177 /* NB: G.global_argv[0] ($0) is never freed/changed */
6178 g_argv = G.global_argv;
6179 if (G.global_args_malloced) {
6185 G.global_args_malloced = 1;
6186 pp = xzalloc(sizeof(pp[0]) * 2);
6187 pp[0] = g_argv[0]; /* retain $0 */
6190 /* This realloc's G.global_argv */
6191 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6198 return EXIT_SUCCESS;
6200 /* Nothing known, so abort */
6202 bb_error_msg("set: %s: invalid option", arg);
6203 return EXIT_FAILURE;
6206 static int builtin_shift(char **argv)
6212 if (n >= 0 && n < G.global_argc) {
6213 if (G.global_args_malloced) {
6216 free(G.global_argv[m++]);
6219 memmove(&G.global_argv[1], &G.global_argv[n+1],
6220 G.global_argc * sizeof(G.global_argv[0]));
6221 return EXIT_SUCCESS;
6223 return EXIT_FAILURE;
6226 static int builtin_source(char **argv)
6230 if (*++argv == NULL)
6231 return EXIT_FAILURE;
6233 /* XXX search through $PATH is missing */
6234 input = fopen_or_warn(*argv, "r");
6236 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6237 return EXIT_FAILURE;
6239 close_on_exec_on(fileno(input));
6241 /* Now run the file */
6243 /* XXX argv and argc are broken; need to save old G.global_argv
6244 * (pointer only is OK!) on this stack frame,
6245 * set G.global_argv=argv+1, recurse, and restore. */
6246 parse_and_run_file(input);
6248 return G.last_exitcode;
6251 static int builtin_umask(char **argv)
6254 const char *arg = argv[1];
6256 //TODO: umask may take chmod-like symbolic masks
6257 new_umask = bb_strtou(arg, NULL, 8);
6259 //Message? bash examples:
6260 //bash: umask: 'q': invalid symbolic mode operator
6261 //bash: umask: 999: octal number out of range
6262 return EXIT_FAILURE;
6265 new_umask = umask(0);
6266 printf("%.3o\n", (unsigned) new_umask);
6267 /* fall through and restore new_umask which we set to 0 */
6270 return EXIT_SUCCESS;
6273 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6274 static int builtin_unset(char **argv)
6280 return EXIT_SUCCESS;
6283 if (argv[0][0] == '-') {
6284 switch (argv[0][1]) {
6290 bb_error_msg("unset: %s: invalid option", *argv);
6291 return EXIT_FAILURE;
6293 //TODO: disallow "unset -vf ..." too
6300 if (unset_local_var(*argv)) {
6301 /* unset <nonexistent_var> doesn't fail.
6302 * Error is when one tries to unset RO var.
6303 * Message was printed by unset_local_var. */
6307 #if ENABLE_HUSH_FUNCTIONS
6309 unset_local_func(*argv);
6317 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6318 static int builtin_wait(char **argv)
6320 int ret = EXIT_SUCCESS;
6323 if (*++argv == NULL) {
6324 /* Don't care about wait results */
6325 /* Note 1: must wait until there are no more children */
6326 /* Note 2: must be interruptible */
6328 * $ sleep 3 & sleep 6 & wait
6333 * $ sleep 3 & sleep 6 & wait
6337 * ^C <-- after ~4 sec from keyboard
6340 sigaddset(&G.blocked_set, SIGCHLD);
6341 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6344 if (errno == ECHILD)
6346 /* Wait for SIGCHLD or any other signal of interest */
6347 /* sigtimedwait with infinite timeout: */
6348 sig = sigwaitinfo(&G.blocked_set, NULL);
6350 sig = check_and_run_traps(sig);
6351 if (sig && sig != SIGCHLD) { /* see note 2 */
6357 sigdelset(&G.blocked_set, SIGCHLD);
6358 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6362 /* This is probably buggy wrt interruptible-ness */
6364 pid_t pid = bb_strtou(*argv, NULL, 10);
6366 /* mimic bash message */
6367 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6368 return EXIT_FAILURE;
6370 if (waitpid(pid, &status, 0) == pid) {
6371 if (WIFSIGNALED(status))
6372 ret = 128 + WTERMSIG(status);
6373 else if (WIFEXITED(status))
6374 ret = WEXITSTATUS(status);
6378 bb_perror_msg("wait %s", *argv);
6387 #if ENABLE_HUSH_LOOPS
6388 static int builtin_break(char **argv)
6390 if (G.depth_of_loop == 0) {
6391 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6392 return EXIT_SUCCESS; /* bash compat */
6394 G.flag_break_continue++; /* BC_BREAK = 1 */
6395 G.depth_break_continue = 1;
6397 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6398 if (errno || !G.depth_break_continue || argv[2]) {
6399 bb_error_msg("%s: bad arguments", argv[0]);
6400 G.flag_break_continue = BC_BREAK;
6401 G.depth_break_continue = UINT_MAX;
6404 if (G.depth_of_loop < G.depth_break_continue)
6405 G.depth_break_continue = G.depth_of_loop;
6406 return EXIT_SUCCESS;
6409 static int builtin_continue(char **argv)
6411 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6412 return builtin_break(argv);