1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
12 * The parser routines proper are all original material, first
13 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
14 * execution engine, the builtins, and much of the underlying
15 * support has been adapted from busybox-0.49pre's lash, which is
16 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
17 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
18 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
19 * Troan, which they placed in the public domain. I don't know
20 * how much of the Johnson/Troan code has survived the repeated
24 * o_addchr derived from similar w_addchar function in glibc-2.2.
25 * parse_redirect, redirect_opt_num, and big chunks of main
26 * and many builtins derived from contributions by Erik Andersen.
27 * Miscellaneous bugfixes from Matt Kraai.
29 * There are two big (and related) architecture differences between
30 * this parser and the lash parser. One is that this version is
31 * actually designed from the ground up to understand nearly all
32 * of the Bourne grammar. The second, consequential change is that
33 * the parser and input reader have been turned inside out. Now,
34 * the parser is in control, and asks for input as needed. The old
35 * way had the input reader in control, and it asked for parsing to
36 * take place as needed. The new way makes it much easier to properly
37 * handle the recursion implicit in the various substitutions, especially
38 * across continuation lines.
40 * POSIX syntax not implemented:
42 * <(list) and >(list) Process Substitution
46 * Bash stuff (maybe optionally enable?):
47 * &> and >& redirection of stdout+stderr
49 * reserved words: [[ ]] function select
50 * substrings ${var:1:5}
53 * grep for "TODO" and fix (some of them are easy)
54 * change { and } from special chars to reserved words
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * ^Z handling (and explain it in comments for mere humans)
61 * separate job control from interactiveness
62 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
65 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
68 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
69 //TODO: pull in some .h and find out whether we have SINGLE_APPLET_MAIN?
70 //#include "applet_tables.h" doesn't work
72 /* #include <dmalloc.h> */
79 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
82 #ifdef WANT_TO_TEST_NOMMU
87 # define USE_FOR_NOMMU(...) __VA_ARGS__
88 # define USE_FOR_MMU(...)
91 #if defined SINGLE_APPLET_MAIN
92 /* STANDALONE does not make sense, and won't compile */
93 #undef CONFIG_FEATURE_SH_STANDALONE
94 #undef ENABLE_FEATURE_SH_STANDALONE
95 #undef USE_FEATURE_SH_STANDALONE
96 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
97 #define ENABLE_FEATURE_SH_STANDALONE 0
98 #define USE_FEATURE_SH_STANDALONE(...)
99 #define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 #if !ENABLE_HUSH_INTERACTIVE
103 #undef ENABLE_FEATURE_EDITING
104 #define ENABLE_FEATURE_EDITING 0
105 #undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
106 #define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
109 /* Do we support ANY keywords? */
110 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
111 #define HAS_KEYWORDS 1
112 #define IF_HAS_KEYWORDS(...) __VA_ARGS__
113 #define IF_HAS_NO_KEYWORDS(...)
115 #define HAS_KEYWORDS 0
116 #define IF_HAS_KEYWORDS(...)
117 #define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
120 /* Enable/disable sanity checks. Ok to enable in production,
121 * only adds a bit of bloat.
122 * Keeping unconditionally on for now.
126 #define ENABLE_HUSH_FUNCTIONS 0
129 /* If you comment out one of these below, it will be #defined later
130 * to perform debug printfs to stderr: */
131 #define debug_printf(...) do {} while (0)
132 /* Finer-grained debug switches */
133 #define debug_printf_parse(...) do {} while (0)
134 #define debug_print_tree(a, b) do {} while (0)
135 #define debug_printf_exec(...) do {} while (0)
136 #define debug_printf_env(...) do {} while (0)
137 #define debug_printf_jobs(...) do {} while (0)
138 #define debug_printf_expand(...) do {} while (0)
139 #define debug_printf_glob(...) do {} while (0)
140 #define debug_printf_list(...) do {} while (0)
141 #define debug_printf_subst(...) do {} while (0)
142 #define debug_printf_clean(...) do {} while (0)
145 #define debug_printf(...) fprintf(stderr, __VA_ARGS__)
148 #ifndef debug_printf_parse
149 #define debug_printf_parse(...) fprintf(stderr, __VA_ARGS__)
152 #ifndef debug_printf_exec
153 #define debug_printf_exec(...) fprintf(stderr, __VA_ARGS__)
156 #ifndef debug_printf_env
157 #define debug_printf_env(...) fprintf(stderr, __VA_ARGS__)
160 #ifndef debug_printf_jobs
161 #define debug_printf_jobs(...) fprintf(stderr, __VA_ARGS__)
167 #ifndef debug_printf_expand
168 #define debug_printf_expand(...) fprintf(stderr, __VA_ARGS__)
169 #define DEBUG_EXPAND 1
171 #define DEBUG_EXPAND 0
174 #ifndef debug_printf_glob
175 #define debug_printf_glob(...) fprintf(stderr, __VA_ARGS__)
181 #ifndef debug_printf_list
182 #define debug_printf_list(...) fprintf(stderr, __VA_ARGS__)
185 #ifndef debug_printf_subst
186 #define debug_printf_subst(...) fprintf(stderr, __VA_ARGS__)
189 #ifndef debug_printf_clean
190 /* broken, of course, but OK for testing */
191 static const char *indenter(int i)
193 static const char blanks[] ALIGN1 =
195 return &blanks[sizeof(blanks) - i - 1];
197 #define debug_printf_clean(...) fprintf(stderr, __VA_ARGS__)
198 #define DEBUG_CLEAN 1
200 #define DEBUG_CLEAN 0
204 static void debug_print_strings(const char *prefix, char **vv)
206 fprintf(stderr, "%s:\n", prefix);
208 fprintf(stderr, " '%s'\n", *vv++);
211 #define debug_print_strings(prefix, vv) ((void)0)
215 * Leak hunting. Use hush_leaktool.sh for post-processing.
217 //#define FOR_HUSH_LEAKTOOL
218 #ifdef FOR_HUSH_LEAKTOOL
219 static void *xxmalloc(int lineno, size_t size)
221 void *ptr = xmalloc((size + 0xff) & ~0xff);
222 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
225 static void *xxrealloc(int lineno, void *ptr, size_t size)
227 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
228 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
231 static char *xxstrdup(int lineno, const char *str)
233 char *ptr = xstrdup(str);
234 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
237 static void xxfree(void *ptr)
239 fdprintf(2, "free %p\n", ptr);
242 #define xmalloc(s) xxmalloc(__LINE__, s)
243 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
244 #define xstrdup(s) xxstrdup(__LINE__, s)
245 #define free(p) xxfree(p)
249 #define ERR_PTR ((void*)(long)1)
251 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
253 #define SPECIAL_VAR_SYMBOL 3
255 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
257 /* This supports saving pointers malloced in vfork child,
258 * to be freed in the parent. One pointer is saved in
259 * G.argv_from_re_execing global var instead. TODO: unify.
262 typedef struct nommu_save_t {
269 /* The descrip member of this structure is only used to make
270 * debugging output pretty */
271 static const struct {
273 signed char default_fd;
277 { O_RDONLY, 0, "<" },
278 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
279 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
280 { O_RDONLY, 0, "<<" },
281 { O_CREAT|O_RDWR, 1, "<>" },
282 /* Should not be needed. Bogus default_fd helps in debugging */
283 /* { O_RDONLY, 77, "<<" }, */
286 typedef enum reserved_style {
295 #if ENABLE_HUSH_LOOPS
302 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
307 /* two pseudo-keywords support contrived "case" syntax: */
308 RES_MATCH , /* "word)" */
309 RES_CASEI , /* "this command is inside CASE" */
316 typedef struct o_string {
318 int length; /* position where data is appended */
320 /* Protect newly added chars against globbing
321 * (by prepending \ to *, ?, [, \) */
324 /* At least some part of the string was inside '' or "",
325 * possibly empty one: word"", wo''rd etc. */
327 smallint has_empty_slot;
328 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
331 MAYBE_ASSIGNMENT = 0,
332 DEFINITELY_ASSIGNMENT = 1,
334 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
336 /* Used for initialization: o_string foo = NULL_O_STRING; */
337 #define NULL_O_STRING { NULL }
339 /* I can almost use ordinary FILE*. Is open_memstream() universally
340 * available? Where is it documented? */
341 typedef struct in_str {
343 /* eof_flag=1: last char in ->p is really an EOF */
344 char eof_flag; /* meaningless if ->p == NULL */
346 #if ENABLE_HUSH_INTERACTIVE
348 smallint promptmode; /* 0: PS1, 1: PS2 */
351 int (*get) (struct in_str *);
352 int (*peek) (struct in_str *);
354 #define i_getch(input) ((input)->get(input))
355 #define i_peek(input) ((input)->peek(input))
357 struct redir_struct {
358 struct redir_struct *next;
359 char *rd_filename; /* filename */
360 int rd_fd; /* fd to redirect */
361 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
363 smallint rd_type; /* (enum redir_type) */
364 /* note: for heredocs, rd_filename contains heredoc delimiter,
365 * and subsequently heredoc itself; and rd_dup is a bitmask:
366 * 1: do we need to trim leading tabs?
367 * 2: is heredoc quoted (<<'dleim' syntax) ?
370 typedef enum redir_type {
371 REDIRECT_INVALID = 0,
373 REDIRECT_OVERWRITE = 2,
375 REDIRECT_HEREDOC = 4,
377 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
379 HEREDOC_SKIPTABS = 1,
385 pid_t pid; /* 0 if exited */
386 int assignment_cnt; /* how many argv[i] are assignments? */
387 smallint is_stopped; /* is the command currently running? */
388 smallint grp_type; /* GRP_xxx */
389 struct pipe *group; /* if non-NULL, this "command" is { list },
390 * ( list ), or a compound statement */
392 char *group_as_string;
394 char **argv; /* command name and arguments */
395 struct redir_struct *redirects; /* I/O redirections */
397 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
398 * and on execution these are substituted with their values.
399 * Substitution can make _several_ words out of one argv[n]!
400 * Example: argv[0]=='.^C*^C.' here: echo .$*.
401 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
404 #define GRP_SUBSHELL 1
405 #if ENABLE_HUSH_FUNCTIONS
406 #define GRP_FUNCTION 2
411 int num_cmds; /* total number of commands in job */
412 int alive_cmds; /* number of commands running (not exited) */
413 int stopped_cmds; /* number of commands alive, but stopped */
415 int jobid; /* job number */
416 pid_t pgrp; /* process group ID for the job */
417 char *cmdtext; /* name of job */
419 struct command *cmds; /* array of commands in pipe */
420 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
421 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
422 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
424 typedef enum pipe_style {
431 /* This holds pointers to the various results of parsing */
432 struct parse_context {
433 /* linked list of pipes */
434 struct pipe *list_head;
435 /* last pipe (being constructed right now) */
437 /* last command in pipe (being constructed right now) */
438 struct command *command;
439 /* last redirect in command->redirects list */
440 struct redir_struct *pending_redirect;
446 smallint ctx_inverted; /* "! cmd | cmd" */
448 smallint ctx_dsemicolon; /* ";;" seen */
450 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
452 /* group we are enclosed in:
453 * example: "if pipe1; pipe2; then pipe3; fi"
454 * when we see "if" or "then", we malloc and copy current context,
455 * and make ->stack point to it. then we parse pipeN.
456 * when closing "then" / fi" / whatever is found,
457 * we move list_head into ->stack->command->group,
458 * copy ->stack into current context, and delete ->stack.
459 * (parsing of { list } and ( list ) doesn't use this method)
461 struct parse_context *stack;
465 /* On program start, environ points to initial environment.
466 * putenv adds new pointers into it, unsetenv removes them.
467 * Neither of these (de)allocates the strings.
468 * setenv allocates new strings in malloc space and does putenv,
469 * and thus setenv is unusable (leaky) for shell's purposes */
470 #define setenv(...) setenv_is_leaky_dont_use()
472 struct variable *next;
473 char *varstr; /* points to "name=" portion */
474 int max_len; /* if > 0, name is part of initial env; else name is malloced */
475 smallint flg_export; /* putenv should be done on this var */
476 smallint flg_read_only;
485 /* "Globals" within this file */
486 /* Sorted roughly by size (smaller offsets == smaller code) */
488 #if ENABLE_HUSH_INTERACTIVE
489 /* 'interactive_fd' is a fd# open to ctty, if we have one
490 * _AND_ if we decided to act interactively */
494 #define G_interactive_fd (G.interactive_fd)
496 #define G_interactive_fd 0
498 #if ENABLE_FEATURE_EDITING
499 line_input_t *line_input_state;
505 pid_t saved_tty_pgrp;
507 struct pipe *job_list;
508 struct pipe *toplevel_list;
509 //// smallint ctrl_z_flag;
511 smallint flag_SIGINT;
512 #if ENABLE_HUSH_LOOPS
513 smallint flag_break_continue;
516 smallint exiting; /* used to prevent EXIT trap recursion */
517 /* These four support $?, $#, and $1 */
518 smalluint last_exitcode;
519 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
520 smalluint global_args_malloced;
521 /* how many non-NULL argv's we have. NB: $# + 1 */
525 char *argv0_for_re_execing;
526 char **argv_from_re_execing;
528 #if ENABLE_HUSH_LOOPS
529 unsigned depth_break_continue;
530 unsigned depth_of_loop;
534 struct variable *top_var; /* = &G.shell_ver (set in main()) */
535 struct variable shell_ver;
536 /* Signal and trap handling */
537 // unsigned count_SIGCHLD;
538 // unsigned handled_SIGCHLD;
539 /* which signals have non-DFL handler (even with no traps set)? */
540 unsigned non_DFL_mask;
541 char **traps; /* char *traps[NSIG] */
542 sigset_t blocked_set;
543 sigset_t inherited_set;
545 unsigned long memleak_value;
547 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
548 #if ENABLE_FEATURE_SH_STANDALONE
549 struct nofork_save_area nofork_save;
552 sigjmp_buf toplevel_jb;
555 #define G (*ptr_to_globals)
556 /* Not #defining name to G.name - this quickly gets unwieldy
557 * (too many defines). Also, I actually prefer to see when a variable
558 * is global, thus "G." prefix is a useful hint */
559 #define INIT_G() do { \
560 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
564 /* Function prototypes for builtins */
565 static int builtin_cd(char **argv);
566 static int builtin_echo(char **argv);
567 static int builtin_eval(char **argv);
568 static int builtin_exec(char **argv);
569 static int builtin_exit(char **argv);
570 static int builtin_export(char **argv);
572 static int builtin_fg_bg(char **argv);
573 static int builtin_jobs(char **argv);
576 static int builtin_help(char **argv);
579 static int builtin_memleak(char **argv);
581 static int builtin_pwd(char **argv);
582 static int builtin_read(char **argv);
583 static int builtin_set(char **argv);
584 static int builtin_shift(char **argv);
585 static int builtin_source(char **argv);
586 static int builtin_test(char **argv);
587 static int builtin_trap(char **argv);
588 static int builtin_true(char **argv);
589 static int builtin_umask(char **argv);
590 static int builtin_unset(char **argv);
591 static int builtin_wait(char **argv);
592 #if ENABLE_HUSH_LOOPS
593 static int builtin_break(char **argv);
594 static int builtin_continue(char **argv);
597 /* Table of built-in functions. They can be forked or not, depending on
598 * context: within pipes, they fork. As simple commands, they do not.
599 * When used in non-forking context, they can change global variables
600 * in the parent shell process. If forked, of course they cannot.
601 * For example, 'unset foo | whatever' will parse and run, but foo will
602 * still be set at the end. */
603 struct built_in_command {
605 int (*function)(char **argv);
608 #define BLTIN(cmd, func, help) { cmd, func, help }
610 #define BLTIN(cmd, func, help) { cmd, func }
614 /* For now, echo and test are unconditionally enabled.
615 * Maybe make it configurable? */
616 static const struct built_in_command bltins[] = {
617 BLTIN("." , builtin_source , "Run commands in a file"),
618 BLTIN(":" , builtin_true , "No-op"),
619 BLTIN("[" , builtin_test , "Test condition"),
621 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
623 #if ENABLE_HUSH_LOOPS
624 BLTIN("break" , builtin_break , "Exit from a loop"),
626 BLTIN("cd" , builtin_cd , "Change directory"),
627 #if ENABLE_HUSH_LOOPS
628 BLTIN("continue", builtin_continue, "Start new loop iteration"),
630 BLTIN("echo" , builtin_echo , "Write to stdout"),
631 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
632 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
633 BLTIN("exit" , builtin_exit , "Exit"),
634 BLTIN("export" , builtin_export , "Set environment variable"),
636 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
639 BLTIN("help" , builtin_help , "List shell built-in commands"),
642 BLTIN("jobs" , builtin_jobs , "List active jobs"),
645 BLTIN("memleak" , builtin_memleak , "Debug tool"),
647 BLTIN("pwd" , builtin_pwd , "Print current directory"),
648 BLTIN("read" , builtin_read , "Input environment variable"),
649 // BLTIN("return" , builtin_return , "Return from a function"),
650 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
651 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
652 BLTIN("test" , builtin_test , "Test condition"),
653 BLTIN("trap" , builtin_trap , "Trap signals"),
654 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
655 BLTIN("umask" , builtin_umask , "Set file creation mask"),
656 BLTIN("unset" , builtin_unset , "Unset environment variable"),
657 BLTIN("wait" , builtin_wait , "Wait for process"),
661 static void maybe_die(const char *notice, const char *msg)
663 /* Was using fancy stuff:
664 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
665 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
666 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
667 #if ENABLE_HUSH_INTERACTIVE
668 if (G_interactive_fd)
671 fp(msg ? "%s: %s" : notice, notice, msg);
674 #define syntax(msg) maybe_die("syntax error", msg);
676 /* Debug -- trick gcc to expand __LINE__ and convert to string */
677 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
678 #define _syntax(msg, line) __syntax(msg, line)
679 #define syntax(msg) _syntax(msg, __LINE__)
683 static int glob_needed(const char *s)
688 if (*s == '*' || *s == '[' || *s == '?')
695 static int is_assignment(const char *s)
697 if (!s || !(isalpha(*s) || *s == '_'))
700 while (isalnum(*s) || *s == '_')
705 /* Replace each \x with x in place, return ptr past NUL. */
706 static char *unbackslash(char *src)
712 if ((*dst++ = *src++) == '\0')
718 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
739 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
740 v[count1 + count2] = NULL;
743 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
746 #ifdef FOR_HUSH_LEAKTOOL
747 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
749 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
750 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
753 #define add_strings_to_strings(strings, add, need_to_dup) \
754 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
757 static char **add_string_to_strings(char **strings, char *add)
762 return add_strings_to_strings(strings, v, /*dup:*/ 0);
764 #ifdef FOR_HUSH_LEAKTOOL
765 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
767 char **ptr = add_string_to_strings(strings, add);
768 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
771 #define add_string_to_strings(strings, add) \
772 xx_add_string_to_strings(__LINE__, strings, add)
775 static void putenv_all(char **strings)
780 debug_printf_env("putenv '%s'\n", *strings);
785 static char **putenv_all_and_save_old(char **strings)
795 eq = strchr(*strings, '=');
798 v = getenv(*strings);
801 /* v points to VAL in VAR=VAL, go back to VAR */
802 v -= (eq - *strings) + 1;
803 old = add_string_to_strings(old, v);
812 static void free_strings_and_unsetenv(char **strings, int unset)
822 debug_printf_env("unsetenv '%s'\n", *v);
830 static void free_strings(char **strings)
832 free_strings_and_unsetenv(strings, 0);
836 /* Basic theory of signal handling in shell
837 * ========================================
838 * This does not describe what hush does, rather, it is current understanding
839 * what it _should_ do. If it doesn't, it's a bug.
840 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
842 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
843 * is finished or backgrounded. It is the same in interactive and
844 * non-interactive shells, and is the same regardless of whether
845 * a user trap handler is installed or a shell special one is in effect.
846 * ^C or ^Z from keyboard seem to execute "at once" because it usually
847 * backgrounds (i.e. stops) or kills all members of currently running
850 * Wait builtin in interruptible by signals for which user trap is set
851 * or by SIGINT in interactive shell.
853 * Trap handlers will execute even within trap handlers. (right?)
855 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
857 * If job control is off, backgrounded commands ("cmd &")
858 * have SIGINT, SIGQUIT set to SIG_IGN.
860 * Commands run in command substitution ("`cmd`")
861 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
863 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
864 * by the shell from its parent.
866 * Siganls which differ from SIG_DFL action
867 * (note: child (i.e., [v]forked) shell is not an interactive shell):
870 * SIGTERM (interactive): ignore
871 * SIGHUP (interactive):
872 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
873 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
874 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
875 * that all pipe members are stopped) (right?)
876 * SIGINT (interactive): wait for last pipe, ignore the rest
877 * of the command line, show prompt. NB: ^C does not send SIGINT
878 * to interactive shell while shell is waiting for a pipe,
879 * since shell is bg'ed (is not in foreground process group).
880 * (check/expand this)
881 * Example 1: this waits 5 sec, but does not execute ls:
882 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
883 * Example 2: this does not wait and does not execute ls:
884 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
885 * Example 3: this does not wait 5 sec, but executes ls:
886 * "sleep 5; ls -l" + press ^C
888 * (What happens to signals which are IGN on shell start?)
889 * (What happens with signal mask on shell start?)
891 * Implementation in hush
892 * ======================
893 * We use in-kernel pending signal mask to determine which signals were sent.
894 * We block all signals which we don't want to take action immediately,
895 * i.e. we block all signals which need to have special handling as described
896 * above, and all signals which have traps set.
897 * After each pipe execution, we extract any pending signals via sigtimedwait()
900 * unsigned non_DFL_mask: a mask of such "special" signals
901 * sigset_t blocked_set: current blocked signal set
904 * clear bit in blocked_set unless it is also in non_DFL_mask
905 * "trap 'cmd' SIGxxx":
906 * set bit in blocked_set (even if 'cmd' is '')
907 * after [v]fork, if we plan to be a shell:
908 * nothing for {} child shell (say, "true | { true; true; } | true")
909 * unset all traps if () shell.
910 * after [v]fork, if we plan to exec:
911 * POSIX says pending signal mask is cleared in child - no need to clear it.
912 * Restore blocked signal set to one inherited by shell just prior to exec.
914 * Note: as a result, we do not use signal handlers much. The only uses
915 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
916 * and to restore tty pgrp on signal-induced exit.
919 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
921 // G.count_SIGCHLD++;
924 static int check_and_run_traps(int sig)
926 static const struct timespec zero_timespec = { 0, 0 };
927 smalluint save_rcode;
933 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
938 if (G.traps && G.traps[sig]) {
939 if (G.traps[sig][0]) {
940 /* We have user-defined handler */
941 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
942 save_rcode = G.last_exitcode;
945 G.last_exitcode = save_rcode;
946 } /* else: "" trap, ignoring signal */
949 /* not a trap: special action */
952 // G.count_SIGCHLD++;
961 default: /* ignored: */
962 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
971 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
972 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
973 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
974 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
976 /* Restores tty foreground process group, and exits.
977 * May be called as signal handler for fatal signal
978 * (will faithfully resend signal to itself, producing correct exit state)
979 * or called directly with -EXITCODE.
980 * We also call it if xfunc is exiting. */
981 static void sigexit(int sig) NORETURN;
982 static void sigexit(int sig)
984 /* Disable all signals: job control, SIGPIPE, etc. */
985 sigprocmask_allsigs(SIG_BLOCK);
987 /* Careful: we can end up here after [v]fork. Do not restore
988 * tty pgrp then, only top-level shell process does that */
989 if (G_interactive_fd && getpid() == G.root_pid)
990 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
992 /* Not a signal, just exit */
996 kill_myself_with_sig(sig); /* does not return */
1000 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1001 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1005 /* Restores tty foreground process group, and exits. */
1006 static void hush_exit(int exitcode) NORETURN;
1007 static void hush_exit(int exitcode)
1009 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1010 /* Prevent recursion:
1011 * trap "echo Hi; exit" EXIT; exit
1013 char *argv[] = { NULL, G.traps[0], NULL };
1021 fflush(NULL); /* flush all streams */
1022 sigexit(- (exitcode & 0xff));
1029 static const char *set_cwd(void)
1031 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1032 * we must not try to free(bb_msg_unknown) */
1033 if (G.cwd == bb_msg_unknown)
1035 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1037 G.cwd = bb_msg_unknown;
1042 /* Get/check local shell variables */
1043 static struct variable *get_local_var(const char *name)
1045 struct variable *cur;
1051 for (cur = G.top_var; cur; cur = cur->next) {
1052 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1058 static const char *get_local_var_value(const char *src)
1060 struct variable *var = get_local_var(src);
1062 return strchr(var->varstr, '=') + 1;
1066 /* str holds "NAME=VAL" and is expected to be malloced.
1067 * We take ownership of it.
1071 * -1: if NAME is set, leave export status alone
1072 * if NAME is not set, do not export
1073 * flg_read_only is set only when we handle -R var=val
1076 #define set_local_var(str, flg_export, flg_read_only) \
1077 set_local_var(str, flg_export)
1079 static int set_local_var(char *str, int flg_export, int flg_read_only)
1081 struct variable *cur;
1085 value = strchr(str, '=');
1086 if (!value) { /* not expected to ever happen? */
1091 name_len = value - str + 1; /* including '=' */
1092 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1094 if (strncmp(cur->varstr, str, name_len) != 0) {
1096 /* Bail out. Note that now cur points
1097 * to last var in linked list */
1103 /* We found an existing var with this name */
1105 if (cur->flg_read_only) {
1109 bb_error_msg("%s: readonly variable", str);
1113 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1114 unsetenv(str); /* just in case */
1116 if (strcmp(cur->varstr, str) == 0) {
1121 if (cur->max_len >= strlen(str)) {
1122 /* This one is from startup env, reuse space */
1123 strcpy(cur->varstr, str);
1126 /* max_len == 0 signifies "malloced" var, which we can
1127 * (and has to) free */
1131 goto set_str_and_exp;
1134 /* Not found - create next variable struct */
1135 cur->next = xzalloc(sizeof(*cur));
1141 cur->flg_read_only = flg_read_only;
1144 if (flg_export == 1)
1145 cur->flg_export = 1;
1146 if (cur->flg_export) {
1147 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1148 return putenv(cur->varstr);
1153 static int unset_local_var(const char *name)
1155 struct variable *cur;
1156 struct variable *prev = prev; /* for gcc */
1160 return EXIT_SUCCESS;
1161 name_len = strlen(name);
1164 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1165 if (cur->flg_read_only) {
1166 bb_error_msg("%s: readonly variable", name);
1167 return EXIT_FAILURE;
1169 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1170 * is ro, and we cannot reach this code on the 1st pass */
1171 prev->next = cur->next;
1172 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1173 bb_unsetenv(cur->varstr);
1177 return EXIT_SUCCESS;
1182 return EXIT_SUCCESS;
1185 #if ENABLE_SH_MATH_SUPPORT
1186 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1187 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1188 static char *endofname(const char *name)
1196 if (!is_in_name(*p))
1202 static void arith_set_local_var(const char *name, const char *val, int flags)
1204 /* arith code doesnt malloc space, so do it for it */
1205 char *var = xasprintf("%s=%s", name, val);
1206 set_local_var(var, flags, 0);
1214 static int static_get(struct in_str *i)
1223 static int static_peek(struct in_str *i)
1228 #if ENABLE_HUSH_INTERACTIVE
1230 static void cmdedit_set_initial_prompt(void)
1232 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1233 G.PS1 = getenv("PS1");
1240 static const char* setup_prompt_string(int promptmode)
1242 const char *prompt_str;
1243 debug_printf("setup_prompt_string %d ", promptmode);
1244 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1245 /* Set up the prompt */
1246 if (promptmode == 0) { /* PS1 */
1248 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1253 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1254 debug_printf("result '%s'\n", prompt_str);
1258 static void get_user_input(struct in_str *i)
1261 const char *prompt_str;
1263 prompt_str = setup_prompt_string(i->promptmode);
1264 #if ENABLE_FEATURE_EDITING
1265 /* Enable command line editing only while a command line
1266 * is actually being read */
1269 /* buglet: SIGINT will not make new prompt to appear _at once_,
1270 * only after <Enter>. (^C will work) */
1271 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1272 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1273 check_and_run_traps(0);
1274 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1275 i->eof_flag = (r < 0);
1276 if (i->eof_flag) { /* EOF/error detected */
1277 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1278 G.user_input_buf[1] = '\0';
1283 fputs(prompt_str, stdout);
1285 G.user_input_buf[0] = r = fgetc(i->file);
1286 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1287 //do we need check_and_run_traps(0)? (maybe only if stdin)
1288 } while (G.flag_SIGINT);
1289 i->eof_flag = (r == EOF);
1291 i->p = G.user_input_buf;
1294 #endif /* INTERACTIVE */
1296 /* This is the magic location that prints prompts
1297 * and gets data back from the user */
1298 static int file_get(struct in_str *i)
1302 /* If there is data waiting, eat it up */
1303 if (i->p && *i->p) {
1304 #if ENABLE_HUSH_INTERACTIVE
1308 if (i->eof_flag && !*i->p)
1310 /* note: ch is never NUL */
1312 /* need to double check i->file because we might be doing something
1313 * more complicated by now, like sourcing or substituting. */
1314 #if ENABLE_HUSH_INTERACTIVE
1315 if (G_interactive_fd && i->promptme && i->file == stdin) {
1318 } while (!*i->p); /* need non-empty line */
1319 i->promptmode = 1; /* PS2 */
1324 do ch = fgetc(i->file); while (ch == '\0');
1326 debug_printf("file_get: got '%c' %d\n", ch, ch);
1327 #if ENABLE_HUSH_INTERACTIVE
1334 /* All callers guarantee this routine will never
1335 * be used right after a newline, so prompting is not needed.
1337 static int file_peek(struct in_str *i)
1340 if (i->p && *i->p) {
1341 if (i->eof_flag && !i->p[1])
1344 /* note: ch is never NUL */
1346 do ch = fgetc(i->file); while (ch == '\0');
1347 i->eof_flag = (ch == EOF);
1348 i->peek_buf[0] = ch;
1349 i->peek_buf[1] = '\0';
1351 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1355 static void setup_file_in_str(struct in_str *i, FILE *f)
1357 i->peek = file_peek;
1359 #if ENABLE_HUSH_INTERACTIVE
1361 i->promptmode = 0; /* PS1 */
1367 static void setup_string_in_str(struct in_str *i, const char *s)
1369 i->peek = static_peek;
1370 i->get = static_get;
1371 #if ENABLE_HUSH_INTERACTIVE
1373 i->promptmode = 0; /* PS1 */
1383 #define B_CHUNK (32 * sizeof(char*))
1385 static void o_reset(o_string *o)
1393 static void o_free(o_string *o)
1396 memset(o, 0, sizeof(*o));
1399 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1404 static void o_grow_by(o_string *o, int len)
1406 if (o->length + len > o->maxlen) {
1407 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1408 o->data = xrealloc(o->data, 1 + o->maxlen);
1412 static void o_addchr(o_string *o, int ch)
1414 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1416 o->data[o->length] = ch;
1418 o->data[o->length] = '\0';
1421 static void o_addblock(o_string *o, const char *str, int len)
1424 memcpy(&o->data[o->length], str, len);
1426 o->data[o->length] = '\0';
1430 static void o_addstr(o_string *o, const char *str)
1432 o_addblock(o, str, strlen(str));
1434 static void nommu_addchr(o_string *o, int ch)
1440 #define nommu_addchr(o, str) ((void)0)
1443 static void o_addstr_with_NUL(o_string *o, const char *str)
1445 o_addblock(o, str, strlen(str) + 1);
1448 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1453 && (*str != '*' && *str != '?' && *str != '[')
1461 /* My analysis of quoting semantics tells me that state information
1462 * is associated with a destination, not a source.
1464 static void o_addqchr(o_string *o, int ch)
1467 char *found = strchr("*?[\\", ch);
1472 o->data[o->length] = '\\';
1475 o->data[o->length] = ch;
1477 o->data[o->length] = '\0';
1480 static void o_addQchr(o_string *o, int ch)
1483 if (o->o_escape && strchr("*?[\\", ch)) {
1485 o->data[o->length] = '\\';
1489 o->data[o->length] = ch;
1491 o->data[o->length] = '\0';
1494 static void o_addQstr(o_string *o, const char *str, int len)
1497 o_addblock(o, str, len);
1503 int ordinary_cnt = strcspn(str, "*?[\\");
1504 if (ordinary_cnt > len) /* paranoia */
1506 o_addblock(o, str, ordinary_cnt);
1507 if (ordinary_cnt == len)
1509 str += ordinary_cnt;
1510 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1514 if (ch) { /* it is necessarily one of "*?[\\" */
1516 o->data[o->length] = '\\';
1520 o->data[o->length] = ch;
1522 o->data[o->length] = '\0';
1526 /* A special kind of o_string for $VAR and `cmd` expansion.
1527 * It contains char* list[] at the beginning, which is grown in 16 element
1528 * increments. Actual string data starts at the next multiple of 16 * (char*).
1529 * list[i] contains an INDEX (int!) into this string data.
1530 * It means that if list[] needs to grow, data needs to be moved higher up
1531 * but list[i]'s need not be modified.
1532 * NB: remembering how many list[i]'s you have there is crucial.
1533 * o_finalize_list() operation post-processes this structure - calculates
1534 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1536 #if DEBUG_EXPAND || DEBUG_GLOB
1537 static void debug_print_list(const char *prefix, o_string *o, int n)
1539 char **list = (char**)o->data;
1540 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1542 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1543 prefix, list, n, string_start, o->length, o->maxlen);
1545 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1546 o->data + (int)list[i] + string_start,
1547 o->data + (int)list[i] + string_start);
1551 const char *p = o->data + (int)list[n - 1] + string_start;
1552 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1556 #define debug_print_list(prefix, o, n) ((void)0)
1559 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1560 * in list[n] so that it points past last stored byte so far.
1561 * It returns n+1. */
1562 static int o_save_ptr_helper(o_string *o, int n)
1564 char **list = (char**)o->data;
1568 if (!o->has_empty_slot) {
1569 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1570 string_len = o->length - string_start;
1571 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1572 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1573 /* list[n] points to string_start, make space for 16 more pointers */
1574 o->maxlen += 0x10 * sizeof(list[0]);
1575 o->data = xrealloc(o->data, o->maxlen + 1);
1576 list = (char**)o->data;
1577 memmove(list + n + 0x10, list + n, string_len);
1578 o->length += 0x10 * sizeof(list[0]);
1580 debug_printf_list("list[%d]=%d string_start=%d\n",
1581 n, string_len, string_start);
1584 /* We have empty slot at list[n], reuse without growth */
1585 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1586 string_len = o->length - string_start;
1587 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1588 n, string_len, string_start);
1589 o->has_empty_slot = 0;
1591 list[n] = (char*)(ptrdiff_t)string_len;
1595 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1596 static int o_get_last_ptr(o_string *o, int n)
1598 char **list = (char**)o->data;
1599 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1601 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1604 /* o_glob performs globbing on last list[], saving each result
1605 * as a new list[]. */
1606 static int o_glob(o_string *o, int n)
1612 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1614 return o_save_ptr_helper(o, n);
1615 pattern = o->data + o_get_last_ptr(o, n);
1616 debug_printf_glob("glob pattern '%s'\n", pattern);
1617 if (!glob_needed(pattern)) {
1619 o->length = unbackslash(pattern) - o->data;
1620 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1621 return o_save_ptr_helper(o, n);
1624 memset(&globdata, 0, sizeof(globdata));
1625 gr = glob(pattern, 0, NULL, &globdata);
1626 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1627 if (gr == GLOB_NOSPACE)
1628 bb_error_msg_and_die("out of memory during glob");
1629 if (gr == GLOB_NOMATCH) {
1630 globfree(&globdata);
1633 if (gr != 0) { /* GLOB_ABORTED ? */
1634 //TODO: testcase for bad glob pattern behavior
1635 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1637 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1638 char **argv = globdata.gl_pathv;
1639 o->length = pattern - o->data; /* "forget" pattern */
1641 o_addstr_with_NUL(o, *argv);
1642 n = o_save_ptr_helper(o, n);
1648 globfree(&globdata);
1650 debug_print_list("o_glob returning", o, n);
1654 /* If o->o_glob == 1, glob the string so far remembered.
1655 * Otherwise, just finish current list[] and start new */
1656 static int o_save_ptr(o_string *o, int n)
1658 if (o->o_glob) { /* if globbing is requested */
1659 /* If o->has_empty_slot, list[n] was already globbed
1660 * (if it was requested back then when it was filled)
1661 * so don't do that again! */
1662 if (!o->has_empty_slot)
1663 return o_glob(o, n); /* o_save_ptr_helper is inside */
1665 return o_save_ptr_helper(o, n);
1668 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1669 static char **o_finalize_list(o_string *o, int n)
1674 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1676 debug_print_list("finalized", o, n);
1677 debug_printf_expand("finalized n:%d\n", n);
1678 list = (char**)o->data;
1679 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1683 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1689 /* Expansion can recurse */
1690 #if ENABLE_HUSH_TICK
1691 static int process_command_subs(o_string *dest, const char *s);
1693 static char *expand_string_to_string(const char *str);
1695 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1696 parse_stream_dquoted(dest, input, dquote_end)
1698 static int parse_stream_dquoted(o_string *as_string,
1700 struct in_str *input,
1703 /* expand_strvec_to_strvec() takes a list of strings, expands
1704 * all variable references within and returns a pointer to
1705 * a list of expanded strings, possibly with larger number
1706 * of strings. (Think VAR="a b"; echo $VAR).
1707 * This new list is allocated as a single malloc block.
1708 * NULL-terminated list of char* pointers is at the beginning of it,
1709 * followed by strings themself.
1710 * Caller can deallocate entire list by single free(list). */
1712 /* Store given string, finalizing the word and starting new one whenever
1713 * we encounter IFS char(s). This is used for expanding variable values.
1714 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1715 static int expand_on_ifs(o_string *output, int n, const char *str)
1718 int word_len = strcspn(str, G.ifs);
1720 if (output->o_escape || !output->o_glob)
1721 o_addQstr(output, str, word_len);
1722 else /* protect backslashes against globbing up :) */
1723 o_addblock_duplicate_backslash(output, str, word_len);
1726 if (!*str) /* EOL - do not finalize word */
1728 o_addchr(output, '\0');
1729 debug_print_list("expand_on_ifs", output, n);
1730 n = o_save_ptr(output, n);
1731 str += strspn(str, G.ifs); /* skip ifs chars */
1733 debug_print_list("expand_on_ifs[1]", output, n);
1737 /* Helper to expand $((...)) and heredoc body. These act as if
1738 * they are in double quotes, with the exception that they are not :).
1739 * Just the rules are similar: "expand only $var and `cmd`"
1741 * Returns malloced string.
1742 * As an optimization, we return NULL if expansion is not needed.
1744 static char *expand_pseudo_dquoted(const char *str)
1747 struct in_str input;
1748 o_string dest = NULL_O_STRING;
1750 if (strchr(str, '$') == NULL
1751 #if ENABLE_HUSH_TICK
1752 && strchr(str, '`') == NULL
1758 /* We need to expand. Example:
1759 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1761 setup_string_in_str(&input, str);
1762 parse_stream_dquoted(NULL, &dest, &input, EOF);
1763 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1764 exp_str = expand_string_to_string(dest.data);
1765 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1766 o_free_unsafe(&dest);
1770 /* Expand all variable references in given string, adding words to list[]
1771 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1772 * to be filled). This routine is extremely tricky: has to deal with
1773 * variables/parameters with whitespace, $* and $@, and constructs like
1774 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1775 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1777 /* or_mask is either 0 (normal case) or 0x80
1778 * (expansion of right-hand side of assignment == 1-element expand.
1779 * It will also do no globbing, and thus we must not backslash-quote!) */
1781 char first_ch, ored_ch;
1789 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1790 debug_print_list("expand_vars_to_list", output, n);
1791 n = o_save_ptr(output, n);
1792 debug_print_list("expand_vars_to_list[0]", output, n);
1794 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1795 #if ENABLE_HUSH_TICK
1796 o_string subst_result = NULL_O_STRING;
1798 #if ENABLE_SH_MATH_SUPPORT
1799 char arith_buf[sizeof(arith_t)*3 + 2];
1801 o_addblock(output, arg, p - arg);
1802 debug_print_list("expand_vars_to_list[1]", output, n);
1804 p = strchr(p, SPECIAL_VAR_SYMBOL);
1806 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1807 /* "$@" is special. Even if quoted, it can still
1808 * expand to nothing (not even an empty string) */
1809 if ((first_ch & 0x7f) != '@')
1810 ored_ch |= first_ch;
1813 switch (first_ch & 0x7f) {
1814 /* Highest bit in first_ch indicates that var is double-quoted */
1816 val = utoa(G.root_pid);
1818 case '!': /* bg pid */
1819 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1821 case '?': /* exitcode */
1822 val = utoa(G.last_exitcode);
1824 case '#': /* argc */
1825 if (arg[1] != SPECIAL_VAR_SYMBOL)
1826 /* actually, it's a ${#var} */
1828 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1833 if (!G.global_argv[i])
1835 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1836 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1837 smallint sv = output->o_escape;
1838 /* unquoted var's contents should be globbed, so don't escape */
1839 output->o_escape = 0;
1840 while (G.global_argv[i]) {
1841 n = expand_on_ifs(output, n, G.global_argv[i]);
1842 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1843 if (G.global_argv[i++][0] && G.global_argv[i]) {
1844 /* this argv[] is not empty and not last:
1845 * put terminating NUL, start new word */
1846 o_addchr(output, '\0');
1847 debug_print_list("expand_vars_to_list[2]", output, n);
1848 n = o_save_ptr(output, n);
1849 debug_print_list("expand_vars_to_list[3]", output, n);
1852 output->o_escape = sv;
1854 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1855 * and in this case should treat it like '$*' - see 'else...' below */
1856 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1858 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1859 if (++i >= G.global_argc)
1861 o_addchr(output, '\0');
1862 debug_print_list("expand_vars_to_list[4]", output, n);
1863 n = o_save_ptr(output, n);
1865 } else { /* quoted $*: add as one word */
1867 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1868 if (!G.global_argv[++i])
1871 o_addchr(output, G.ifs[0]);
1875 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1876 /* "Empty variable", used to make "" etc to not disappear */
1880 #if ENABLE_HUSH_TICK
1881 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1884 //TODO: can we just stuff it into "output" directly?
1885 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1886 process_command_subs(&subst_result, arg);
1887 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1888 val = subst_result.data;
1891 #if ENABLE_SH_MATH_SUPPORT
1892 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1893 arith_eval_hooks_t hooks;
1898 arg++; /* skip '+' */
1899 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1900 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1902 exp_str = expand_pseudo_dquoted(arg);
1903 hooks.lookupvar = get_local_var_value;
1904 hooks.setvar = arith_set_local_var;
1905 hooks.endofname = endofname;
1906 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1911 case -3: maybe_die("arith", "exponent less than 0"); break;
1912 case -2: maybe_die("arith", "divide by zero"); break;
1913 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1914 default: maybe_die("arith", "syntax error"); break;
1917 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1918 sprintf(arith_buf, arith_t_fmt, res);
1923 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1925 bool exp_len = false;
1926 bool exp_null = false;
1928 char exp_save = exp_save; /* for compiler */
1929 char exp_op = exp_op; /* for compiler */
1930 char *exp_word = exp_word; /* for compiler */
1934 arg[0] = first_ch & 0x7f;
1936 /* prepare for expansions */
1937 if (var[0] == '#') {
1938 /* handle length expansion ${#var} */
1942 /* maybe handle parameter expansion */
1943 exp_off = strcspn(var, ":-=+?%#");
1947 exp_save = var[exp_off];
1948 exp_null = exp_save == ':';
1949 exp_word = var + exp_off;
1950 if (exp_null) ++exp_word;
1951 exp_op = *exp_word++;
1952 var[exp_off] = '\0';
1956 /* lookup the variable in question */
1957 if (isdigit(var[0])) {
1958 /* handle_dollar() should have vetted var for us */
1960 if (i < G.global_argc)
1961 val = G.global_argv[i];
1962 /* else val remains NULL: $N with too big N */
1964 val = get_local_var_value(var);
1966 /* handle any expansions */
1968 debug_printf_expand("expand: length of '%s' = ", val);
1969 val = utoa(val ? strlen(val) : 0);
1970 debug_printf_expand("%s\n", val);
1971 } else if (exp_off) {
1972 if (exp_op == '%' || exp_op == '#') {
1973 /* we need to do a pattern match */
1976 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1977 if (exp_op == *exp_word) /* ## or %% */
1979 val = dyn_val = xstrdup(val);
1980 loc = scan(dyn_val, exp_word, zero);
1986 /* we need to do an expansion */
1987 int exp_test = (!val || (exp_null && !val[0]));
1989 exp_test = !exp_test;
1990 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1991 exp_null ? "true" : "false", exp_test);
1994 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1998 if (exp_op == '=') {
1999 if (isdigit(var[0]) || var[0] == '#') {
2000 maybe_die(var, "special vars cannot assign in this way");
2003 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
2004 sprintf(new_var, "%s=%s", var, val);
2005 set_local_var(new_var, -1, 0);
2011 var[exp_off] = exp_save;
2015 #if ENABLE_HUSH_TICK
2018 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2019 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2021 /* unquoted var's contents should be globbed, so don't escape */
2022 smallint sv = output->o_escape;
2023 output->o_escape = 0;
2024 n = expand_on_ifs(output, n, val);
2026 output->o_escape = sv;
2028 } else { /* quoted $VAR, val will be appended below */
2029 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2032 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2034 o_addQstr(output, val, strlen(val));
2038 /* Do the check to avoid writing to a const string */
2039 if (*p != SPECIAL_VAR_SYMBOL)
2040 *p = SPECIAL_VAR_SYMBOL;
2042 #if ENABLE_HUSH_TICK
2043 o_free(&subst_result);
2046 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2049 debug_print_list("expand_vars_to_list[a]", output, n);
2050 /* this part is literal, and it was already pre-quoted
2051 * if needed (much earlier), do not use o_addQstr here! */
2052 o_addstr_with_NUL(output, arg);
2053 debug_print_list("expand_vars_to_list[b]", output, n);
2054 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2055 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2058 /* allow to reuse list[n] later without re-growth */
2059 output->has_empty_slot = 1;
2061 o_addchr(output, '\0');
2066 static char **expand_variables(char **argv, int or_mask)
2071 o_string output = NULL_O_STRING;
2073 if (or_mask & 0x100) {
2074 output.o_escape = 1; /* protect against globbing for "$var" */
2075 /* (unquoted $var will temporarily switch it off) */
2082 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2085 debug_print_list("expand_variables", &output, n);
2087 /* output.data (malloced in one block) gets returned in "list" */
2088 list = o_finalize_list(&output, n);
2089 debug_print_strings("expand_variables[1]", list);
2093 static char **expand_strvec_to_strvec(char **argv)
2095 return expand_variables(argv, 0x100);
2098 /* Used for expansion of right hand of assignments */
2099 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2101 static char *expand_string_to_string(const char *str)
2103 char *argv[2], **list;
2105 argv[0] = (char*)str;
2107 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2109 if (!list[0] || list[1])
2110 bb_error_msg_and_die("BUG in varexp2");
2111 /* actually, just move string 2*sizeof(char*) bytes back */
2112 overlapping_strcpy((char*)list, list[0]);
2113 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2117 /* Used for "eval" builtin */
2118 static char* expand_strvec_to_string(char **argv)
2122 list = expand_variables(argv, 0x80);
2123 /* Convert all NULs to spaces */
2128 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2129 bb_error_msg_and_die("BUG in varexp3");
2130 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2134 overlapping_strcpy((char*)list, list[0]);
2135 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2139 static char **expand_assignments(char **argv, int count)
2143 /* Expand assignments into one string each */
2144 for (i = 0; i < count; i++) {
2145 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2152 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2153 #define clean_up_after_re_execute() ((void)0)
2154 static void reset_traps_to_defaults(void)
2162 for (sig = 0; sig < NSIG; sig++) {
2166 G.traps[sig] = NULL;
2167 /* There is no signal for 0 (EXIT) */
2170 /* there was a trap handler, we are removing it
2171 * (if sig has non-DFL handling,
2172 * we don't need to do anything) */
2173 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2175 sigdelset(&G.blocked_set, sig);
2179 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2184 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2185 static void re_execute_shell(const char *s, int is_heredoc)
2187 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2188 char *heredoc_argv[4];
2189 struct variable *cur;
2190 char **argv, **pp, **pp2;
2194 argv = heredoc_argv;
2195 argv[0] = (char *) G.argv0_for_re_execing;
2196 argv[1] = (char *) "-<";
2197 argv[2] = (char *) s;
2199 pp = &argv[3]; /* used as pointer to empty environment */
2203 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2204 , (unsigned) G.root_pid
2205 , (unsigned) G.last_bg_pid
2206 , (unsigned) G.last_exitcode
2207 USE_HUSH_LOOPS(, G.depth_of_loop)
2209 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2210 * 3:-c 4:<cmd> <argN...> 5:NULL
2212 cnt = 5 + G.global_argc;
2213 for (cur = G.top_var; cur; cur = cur->next) {
2214 if (!cur->flg_export || cur->flg_read_only)
2217 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2218 *pp++ = (char *) G.argv0_for_re_execing;
2220 for (cur = G.top_var; cur; cur = cur->next) {
2221 if (cur->varstr == hush_version_str)
2223 if (cur->flg_read_only) {
2224 *pp++ = (char *) "-R";
2225 *pp++ = cur->varstr;
2226 } else if (!cur->flg_export) {
2227 *pp++ = (char *) "-V";
2228 *pp++ = cur->varstr;
2231 //TODO: pass functions
2232 /* We can pass activated traps here. Say, -Tnn:trap_string
2234 * However, POSIX says that subshells reset signals with traps
2236 * I tested bash-3.2 and it not only does that with true subshells
2237 * of the form ( list ), but with any forked children shells.
2238 * I set trap "echo W" WINCH; and then tried:
2240 * { echo 1; sleep 20; echo 2; } &
2241 * while true; do echo 1; sleep 20; echo 2; break; done &
2242 * true | { echo 1; sleep 20; echo 2; } | cat
2244 * In all these cases sending SIGWINCH to the child shell
2245 * did not run the trap. If I add trap "echo V" WINCH;
2246 * _inside_ group (just before echo 1), it works.
2248 * I conclude it means we don't need to pass active traps here.
2249 * exec syscall below resets them to SIG_DFL for us.
2251 *pp++ = (char *) "-c";
2253 pp2 = G.global_argv;
2256 /* *pp = NULL; - is already there */
2260 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2261 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2262 execve(bb_busybox_exec_path, argv, pp);
2263 /* Fallback. Useful for init=/bin/hush usage etc */
2264 if (argv[0][0] == '/')
2265 execve(argv[0], argv, pp);
2266 xfunc_error_retval = 127;
2267 bb_error_msg_and_die("can't re-execute the shell");
2270 static void clean_up_after_re_execute(void)
2272 char **pp = G.argv_from_re_execing;
2274 /* Must match re_execute_shell's allocations (if any) */
2276 G.argv_from_re_execing = NULL;
2279 #endif /* !BB_MMU */
2282 static void setup_heredoc(struct redir_struct *redir)
2284 struct fd_pair pair;
2287 /* the _body_ of heredoc (misleading field name) */
2288 const char *heredoc = redir->rd_filename;
2292 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2293 expanded = expand_pseudo_dquoted(heredoc);
2297 len = strlen(heredoc);
2299 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2301 xmove_fd(pair.rd, redir->rd_fd);
2303 /* Try writing without forking. Newer kernels have
2304 * dynamically growing pipes. Must use non-blocking write! */
2307 written = write(pair.wr, heredoc, len);
2317 ndelay_off(pair.wr);
2319 /* Okay, pipe buffer was not big enough */
2320 /* Note: we must not create a stray child (bastard? :)
2321 * for the unsuspecting parent process. Child creates a grandchild
2322 * and exits before parent execs the process which consumes heredoc
2323 * (that exec happens after we return from this function) */
2326 bb_perror_msg_and_die("vfork");
2329 pid = BB_MMU ? fork() : vfork();
2331 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2335 close(redir->rd_fd); /* read side of the pipe */
2337 full_write(pair.wr, heredoc, len); /* may loop or block */
2340 /* Delegate blocking writes to another process */
2341 disable_restore_tty_pgrp_on_exit();
2342 xmove_fd(pair.wr, STDOUT_FILENO);
2343 re_execute_shell(heredoc, 1);
2347 enable_restore_tty_pgrp_on_exit();
2348 clean_up_after_re_execute();
2351 wait(NULL); /* wait till child has died */
2354 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2355 * and stderr if they are redirected. */
2356 static int setup_redirects(struct command *prog, int squirrel[])
2359 struct redir_struct *redir;
2361 for (redir = prog->redirects; redir; redir = redir->next) {
2362 if (redir->rd_type == REDIRECT_HEREDOC2) {
2363 if (squirrel && redir->rd_fd < 3) {
2364 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2366 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2368 debug_printf_parse("set heredoc '%s'\n",
2369 redir->rd_filename);
2370 setup_heredoc(redir);
2374 if (redir->rd_dup == -1) {
2376 if (redir->rd_filename == NULL) {
2377 /* Something went wrong in the parse.
2378 * Pretend it didn't happen */
2381 mode = redir_table[redir->rd_type].mode;
2382 //TODO: check redir for names like '\\'
2383 p = expand_string_to_string(redir->rd_filename);
2384 openfd = open_or_warn(p, mode);
2387 /* this could get lost if stderr has been redirected, but
2388 * bash and ash both lose it as well (though zsh doesn't!) */
2389 //what the above comment tries to say?
2393 openfd = redir->rd_dup;
2396 if (openfd != redir->rd_fd) {
2397 if (squirrel && redir->rd_fd < 3) {
2398 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2400 if (openfd == REDIRFD_CLOSE) {
2401 /* "n>-" means "close me" */
2402 close(redir->rd_fd);
2404 xdup2(openfd, redir->rd_fd);
2405 if (redir->rd_dup == -1)
2413 static void restore_redirects(int squirrel[])
2416 for (i = 0; i < 3; i++) {
2419 /* We simply die on error */
2427 #define free_pipe_list(head, indent) free_pipe_list(head)
2428 #define free_pipe(pi, indent) free_pipe(pi)
2430 static void free_pipe_list(struct pipe *head, int indent);
2432 /* Return code is the exit status of the pipe */
2433 static void free_pipe(struct pipe *pi, int indent)
2436 struct command *command;
2437 struct redir_struct *r, *rnext;
2440 if (pi->stopped_cmds > 0) /* why? */
2442 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2443 for (i = 0; i < pi->num_cmds; i++) {
2444 command = &pi->cmds[i];
2445 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2446 if (command->argv) {
2447 for (a = 0, p = command->argv; *p; a++, p++) {
2448 debug_printf_clean("%s argv[%d] = %s\n",
2449 indenter(indent), a, *p);
2451 free_strings(command->argv);
2452 command->argv = NULL;
2454 /* not "else if": on syntax error, we may have both! */
2455 if (command->group) {
2456 debug_printf_clean("%s begin group (grp_type:%d)\n",
2457 indenter(indent), command->grp_type);
2458 free_pipe_list(command->group, indent+3);
2459 debug_printf_clean("%s end group\n", indenter(indent));
2460 command->group = NULL;
2463 free(command->group_as_string);
2464 command->group_as_string = NULL;
2466 for (r = command->redirects; r; r = rnext) {
2467 debug_printf_clean("%s redirect %d%s", indenter(indent),
2468 r->fd, redir_table[r->rd_type].descrip);
2469 /* guard against the case >$FOO, where foo is unset or blank */
2470 if (r->rd_filename) {
2471 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2472 free(r->rd_filename);
2473 r->rd_filename = NULL;
2475 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2479 command->redirects = NULL;
2481 free(pi->cmds); /* children are an array, they get freed all at once */
2489 static void free_pipe_list(struct pipe *head, int indent)
2491 struct pipe *pi, *next;
2493 for (pi = head; pi; pi = next) {
2495 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2497 free_pipe(pi, indent);
2498 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2500 /*pi->next = NULL;*/
2507 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2508 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2509 #define pseudo_exec(nommu_save, command, argv_expanded) \
2510 pseudo_exec(command, argv_expanded)
2513 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2515 * XXX no exit() here. If you don't exec, use _exit instead.
2516 * The at_exit handlers apparently confuse the calling process,
2517 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2518 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2519 char **argv, int assignment_cnt,
2520 char **argv_expanded) NORETURN;
2521 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2522 char **argv, int assignment_cnt,
2523 char **argv_expanded)
2527 /* Case when we are here: ... | var=val | ... */
2528 if (!argv[assignment_cnt])
2529 _exit(EXIT_SUCCESS);
2531 new_env = expand_assignments(argv, assignment_cnt);
2533 putenv_all(new_env);
2534 free(new_env); /* optional */
2536 nommu_save->new_env = new_env;
2537 nommu_save->old_env = putenv_all_and_save_old(new_env);
2539 if (argv_expanded) {
2540 argv = argv_expanded;
2542 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2544 nommu_save->argv = argv;
2548 /* On NOMMU, we must never block!
2549 * Example: { sleep 99999 | read line } & echo Ok
2550 * read builtin will block on read syscall, leaving parent blocked
2551 * in vfork. Therefore we can't do this:
2554 /* Check if the command matches any of the builtins.
2555 * Depending on context, this might be redundant. But it's
2556 * easier to waste a few CPU cycles than it is to figure out
2557 * if this is one of those cases.
2561 const struct built_in_command *x;
2562 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2563 if (strcmp(argv[0], x->cmd) == 0) {
2564 debug_printf_exec("running builtin '%s'\n",
2566 rcode = x->function(argv);
2574 #if ENABLE_FEATURE_SH_STANDALONE
2575 /* Check if the command matches any busybox applets */
2576 if (strchr(argv[0], '/') == NULL) {
2577 int a = find_applet_by_name(argv[0]);
2579 #if BB_MMU /* see above why on NOMMU it is not allowed */
2580 if (APPLET_IS_NOEXEC(a)) {
2581 debug_printf_exec("running applet '%s'\n", argv[0]);
2582 run_applet_no_and_exit(a, argv);
2585 /* Re-exec ourselves */
2586 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2587 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2588 execv(bb_busybox_exec_path, argv);
2589 /* If they called chroot or otherwise made the binary no longer
2590 * executable, fall through */
2595 debug_printf_exec("execing '%s'\n", argv[0]);
2596 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2597 execvp(argv[0], argv);
2598 bb_perror_msg("can't exec '%s'", argv[0]);
2599 _exit(EXIT_FAILURE);
2602 static int run_list(struct pipe *pi);
2604 /* Called after [v]fork() in run_pipe
2606 static void pseudo_exec(nommu_save_t *nommu_save,
2607 struct command *command,
2608 char **argv_expanded) NORETURN;
2609 static void pseudo_exec(nommu_save_t *nommu_save,
2610 struct command *command,
2611 char **argv_expanded)
2613 if (command->argv) {
2614 pseudo_exec_argv(nommu_save, command->argv,
2615 command->assignment_cnt, argv_expanded);
2618 if (command->group) {
2619 /* Cases when we are here:
2622 * ... | ( list ) | ...
2623 * ... | { list } | ...
2627 debug_printf_exec("pseudo_exec: run_list\n");
2628 reset_traps_to_defaults();
2629 rcode = run_list(command->group);
2630 /* OK to leak memory by not calling free_pipe_list,
2631 * since this process is about to exit */
2634 re_execute_shell(command->group_as_string, 0);
2638 /* Case when we are here: ... | >file */
2639 debug_printf_exec("pseudo_exec'ed null command\n");
2640 _exit(EXIT_SUCCESS);
2644 static const char *get_cmdtext(struct pipe *pi)
2650 /* This is subtle. ->cmdtext is created only on first backgrounding.
2651 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2652 * On subsequent bg argv is trashed, but we won't use it */
2655 argv = pi->cmds[0].argv;
2656 if (!argv || !argv[0]) {
2657 pi->cmdtext = xzalloc(1);
2662 do len += strlen(*argv) + 1; while (*++argv);
2663 pi->cmdtext = p = xmalloc(len);
2664 argv = pi->cmds[0].argv;
2666 len = strlen(*argv);
2667 memcpy(p, *argv, len);
2675 static void insert_bg_job(struct pipe *pi)
2677 struct pipe *thejob;
2680 /* Linear search for the ID of the job to use */
2682 for (thejob = G.job_list; thejob; thejob = thejob->next)
2683 if (thejob->jobid >= pi->jobid)
2684 pi->jobid = thejob->jobid + 1;
2686 /* Add thejob to the list of running jobs */
2688 thejob = G.job_list = xmalloc(sizeof(*thejob));
2690 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2692 thejob->next = xmalloc(sizeof(*thejob));
2693 thejob = thejob->next;
2696 /* Physically copy the struct job */
2697 memcpy(thejob, pi, sizeof(struct pipe));
2698 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2699 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2700 for (i = 0; i < pi->num_cmds; i++) {
2701 // TODO: do we really need to have so many fields which are just dead weight
2702 // at execution stage?
2703 thejob->cmds[i].pid = pi->cmds[i].pid;
2704 /* all other fields are not used and stay zero */
2706 thejob->next = NULL;
2707 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2709 /* We don't wait for background thejobs to return -- append it
2710 to the list of backgrounded thejobs and leave it alone */
2711 if (G_interactive_fd)
2712 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2713 G.last_bg_pid = thejob->cmds[0].pid;
2714 G.last_jobid = thejob->jobid;
2717 static void remove_bg_job(struct pipe *pi)
2719 struct pipe *prev_pipe;
2721 if (pi == G.job_list) {
2722 G.job_list = pi->next;
2724 prev_pipe = G.job_list;
2725 while (prev_pipe->next != pi)
2726 prev_pipe = prev_pipe->next;
2727 prev_pipe->next = pi->next;
2730 G.last_jobid = G.job_list->jobid;
2735 /* Remove a backgrounded job */
2736 static void delete_finished_bg_job(struct pipe *pi)
2739 pi->stopped_cmds = 0;
2745 /* Check to see if any processes have exited -- if they
2746 * have, figure out why and see if a job has completed */
2747 static int checkjobs(struct pipe* fg_pipe)
2757 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2760 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2761 // /* avoid doing syscall, nothing there anyway */
2764 attributes = WUNTRACED;
2765 if (fg_pipe == NULL)
2766 attributes |= WNOHANG;
2768 /* Do we do this right?
2769 * bash-3.00# sleep 20 | false
2771 * [3]+ Stopped sleep 20 | false
2772 * bash-3.00# echo $?
2773 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2776 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2777 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2778 // + killall -STOP cat
2785 // i = G.count_SIGCHLD;
2786 childpid = waitpid(-1, &status, attributes);
2787 if (childpid <= 0) {
2788 if (childpid && errno != ECHILD)
2789 bb_perror_msg("waitpid");
2790 // else /* Until next SIGCHLD, waitpid's are useless */
2791 // G.handled_SIGCHLD = i;
2794 dead = WIFEXITED(status) || WIFSIGNALED(status);
2797 if (WIFSTOPPED(status))
2798 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2799 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2800 if (WIFSIGNALED(status))
2801 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2802 childpid, WTERMSIG(status), WEXITSTATUS(status));
2803 if (WIFEXITED(status))
2804 debug_printf_jobs("pid %d exited, exitcode %d\n",
2805 childpid, WEXITSTATUS(status));
2807 /* Were we asked to wait for fg pipe? */
2809 for (i = 0; i < fg_pipe->num_cmds; i++) {
2810 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2811 if (fg_pipe->cmds[i].pid != childpid)
2813 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2815 fg_pipe->cmds[i].pid = 0;
2816 fg_pipe->alive_cmds--;
2817 if (i == fg_pipe->num_cmds - 1) {
2818 /* last process gives overall exitstatus */
2819 rcode = WEXITSTATUS(status);
2820 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2823 fg_pipe->cmds[i].is_stopped = 1;
2824 fg_pipe->stopped_cmds++;
2826 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2827 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2828 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2829 /* All processes in fg pipe have exited/stopped */
2831 if (fg_pipe->alive_cmds)
2832 insert_bg_job(fg_pipe);
2836 /* There are still running processes in the fg pipe */
2837 goto wait_more; /* do waitpid again */
2839 /* it wasnt fg_pipe, look for process in bg pipes */
2843 /* We asked to wait for bg or orphaned children */
2844 /* No need to remember exitcode in this case */
2845 for (pi = G.job_list; pi; pi = pi->next) {
2846 for (i = 0; i < pi->num_cmds; i++) {
2847 if (pi->cmds[i].pid == childpid)
2848 goto found_pi_and_prognum;
2851 /* Happens when shell is used as init process (init=/bin/sh) */
2852 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2853 continue; /* do waitpid again */
2855 found_pi_and_prognum:
2858 pi->cmds[i].pid = 0;
2860 if (!pi->alive_cmds) {
2861 if (G_interactive_fd)
2862 printf(JOB_STATUS_FORMAT, pi->jobid,
2863 "Done", pi->cmdtext);
2864 delete_finished_bg_job(pi);
2868 pi->cmds[i].is_stopped = 1;
2872 } /* while (waitpid succeeds)... */
2878 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2881 int rcode = checkjobs(fg_pipe);
2882 /* Job finished, move the shell to the foreground */
2883 p = getpgid(0); /* pgid of our process */
2884 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2885 tcsetpgrp(G_interactive_fd, p);
2890 /* Start all the jobs, but don't wait for anything to finish.
2893 * Return code is normally -1, when the caller has to wait for children
2894 * to finish to determine the exit status of the pipe. If the pipe
2895 * is a simple builtin command, however, the action is done by the
2896 * time run_pipe returns, and the exit code is provided as the
2899 * Returns -1 only if started some children. IOW: we have to
2900 * mask out retvals of builtins etc with 0xff!
2902 * The only case when we do not need to [v]fork is when the pipe
2903 * is single, non-backgrounded, non-subshell command. Examples:
2904 * cmd ; ... { list } ; ...
2905 * cmd && ... { list } && ...
2906 * cmd || ... { list } || ...
2907 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2908 * or (if SH_STANDALONE) an applet, and we can run the { list }
2909 * with run_list(). If it isn't one of these, we fork and exec cmd.
2911 * Cases when we must fork:
2912 * non-single: cmd | cmd
2913 * backgrounded: cmd & { list } &
2914 * subshell: ( list ) [&]
2916 static int run_pipe(struct pipe *pi)
2918 static const char *const null_ptr = NULL;
2921 int pipefds[2]; /* pipefds[0] is for reading */
2922 struct command *command;
2923 char **argv_expanded;
2926 /* it is not always needed, but we aim to smaller code */
2927 int squirrel[] = { -1, -1, -1 };
2930 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2932 USE_HUSH_JOB(pi->pgrp = -1;)
2933 pi->stopped_cmds = 0;
2934 command = &(pi->cmds[0]);
2935 argv_expanded = NULL;
2937 if (pi->num_cmds != 1
2938 || pi->followup == PIPE_BG
2939 || command->grp_type == GRP_SUBSHELL
2946 debug_printf_exec(": group:%p argv:'%s'\n",
2947 command->group, command->argv ? command->argv[0] : "NONE");
2949 if (command->group) {
2950 #if ENABLE_HUSH_FUNCTIONS
2951 if (command->grp_type == GRP_FUNCTION) {
2952 /* func () { list } */
2953 bb_error_msg("here we ought to remember function definition, and go on");
2954 return EXIT_SUCCESS;
2958 debug_printf("non-subshell group\n");
2959 rcode = 1; /* exitcode if redir failed */
2960 if (setup_redirects(command, squirrel) == 0) {
2961 debug_printf_exec(": run_list\n");
2962 rcode = run_list(command->group) & 0xff;
2963 debug_printf_exec("run_pipe return %d\n", rcode);
2965 restore_redirects(squirrel);
2966 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2970 argv = command->argv ? command->argv : (char **) &null_ptr;
2972 const struct built_in_command *x;
2973 char **new_env = NULL;
2974 char **old_env = NULL;
2976 if (argv[command->assignment_cnt] == NULL) {
2977 /* Assignments, but no command */
2978 /* Ensure redirects take effect. Try "a=t >file" */
2979 rcode = setup_redirects(command, squirrel);
2980 restore_redirects(squirrel);
2981 /* Set shell variables */
2983 p = expand_string_to_string(*argv);
2984 debug_printf_exec("set shell var:'%s'->'%s'\n",
2986 set_local_var(p, 0, 0);
2989 /* Do we need to flag set_local_var() errors?
2990 * "assignment to readonly var" and "putenv error"
2992 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2996 /* Expand the rest into (possibly) many strings each */
2997 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2999 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
3000 if (strcmp(argv_expanded[0], x->cmd) != 0)
3002 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3003 debug_printf("exec with redirects only\n");
3004 rcode = setup_redirects(command, NULL);
3005 goto clean_up_and_ret1;
3007 debug_printf("builtin inline %s\n", argv_expanded[0]);
3008 /* XXX setup_redirects acts on file descriptors, not FILEs.
3009 * This is perfect for work that comes after exec().
3010 * Is it really safe for inline use? Experimentally,
3011 * things seem to work with glibc. */
3012 rcode = setup_redirects(command, squirrel);
3014 new_env = expand_assignments(argv, command->assignment_cnt);
3015 old_env = putenv_all_and_save_old(new_env);
3016 debug_printf_exec(": builtin '%s' '%s'...\n",
3017 x->cmd, argv_expanded[1]);
3018 rcode = x->function(argv_expanded) & 0xff;
3020 #if ENABLE_FEATURE_SH_STANDALONE
3023 restore_redirects(squirrel);
3024 free_strings_and_unsetenv(new_env, 1);
3025 putenv_all(old_env);
3026 /* Free the pointers, but the strings themselves
3027 * are in environ now, don't use free_strings! */
3030 free(argv_expanded);
3031 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3032 debug_printf_exec("run_pipe return %d\n", rcode);
3035 #if ENABLE_FEATURE_SH_STANDALONE
3036 i = find_applet_by_name(argv_expanded[0]);
3037 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3038 rcode = setup_redirects(command, squirrel);
3040 save_nofork_data(&G.nofork_save);
3041 new_env = expand_assignments(argv, command->assignment_cnt);
3042 old_env = putenv_all_and_save_old(new_env);
3043 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3044 argv_expanded[0], argv_expanded[1]);
3045 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3047 goto clean_up_and_ret;
3050 /* It is neither builtin nor applet. We must fork. */
3054 /* NB: argv_expanded may already be created, and that
3055 * might include `cmd` runs! Do not rerun it! We *must*
3056 * use argv_expanded if it's non-NULL */
3058 /* Going to fork a child per each pipe member */
3062 for (i = 0; i < pi->num_cmds; i++) {
3064 volatile nommu_save_t nommu_save;
3065 nommu_save.new_env = NULL;
3066 nommu_save.old_env = NULL;
3067 nommu_save.argv = NULL;
3069 command = &(pi->cmds[i]);
3070 if (command->argv) {
3071 debug_printf_exec(": pipe member '%s' '%s'...\n",
3072 command->argv[0], command->argv[1]);
3074 debug_printf_exec(": pipe member with no argv\n");
3077 /* pipes are inserted between pairs of commands */
3080 if ((i + 1) < pi->num_cmds)
3083 command->pid = BB_MMU ? fork() : vfork();
3084 if (!command->pid) { /* child */
3086 disable_restore_tty_pgrp_on_exit();
3088 /* Every child adds itself to new process group
3089 * with pgid == pid_of_first_child_in_pipe */
3090 if (G.run_list_level == 1 && G_interactive_fd) {
3093 if (pgrp < 0) /* true for 1st process only */
3095 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3096 /* We do it in *every* child, not just first,
3098 tcsetpgrp(G_interactive_fd, pgrp);
3102 xmove_fd(nextin, 0);
3103 xmove_fd(pipefds[1], 1); /* write end */
3105 close(pipefds[0]); /* read end */
3106 /* Like bash, explicit redirects override pipes,
3107 * and the pipe fd is available for dup'ing. */
3108 if (setup_redirects(command, NULL))
3111 /* Restore default handlers just prior to exec */
3112 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3114 /* Stores to nommu_save list of env vars putenv'ed
3115 * (NOMMU, on MMU we don't need that) */
3116 /* cast away volatility... */
3117 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3118 /* pseudo_exec() does not return */
3121 /* parent or error */
3122 enable_restore_tty_pgrp_on_exit();
3124 /* Clean up after vforked child */
3125 clean_up_after_re_execute();
3126 free(nommu_save.argv);
3127 free_strings_and_unsetenv(nommu_save.new_env, 1);
3128 putenv_all(nommu_save.old_env);
3129 /* Free the pointers, but the strings themselves
3130 * are in environ now, don't use free_strings! */
3131 free(nommu_save.old_env);
3133 free(argv_expanded);
3134 argv_expanded = NULL;
3135 if (command->pid < 0) { /* [v]fork failed */
3136 /* Clearly indicate, was it fork or vfork */
3137 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3141 /* Second and next children need to know pid of first one */
3143 pi->pgrp = command->pid;
3149 if ((i + 1) < pi->num_cmds)
3150 close(pipefds[1]); /* write end */
3151 /* Pass read (output) pipe end to next iteration */
3152 nextin = pipefds[0];
3155 if (!pi->alive_cmds) {
3156 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3160 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3164 #ifndef debug_print_tree
3165 static void debug_print_tree(struct pipe *pi, int lvl)
3167 static const char *const PIPE[] = {
3173 static const char *RES[] = {
3174 [RES_NONE ] = "NONE" ,
3177 [RES_THEN ] = "THEN" ,
3178 [RES_ELIF ] = "ELIF" ,
3179 [RES_ELSE ] = "ELSE" ,
3182 #if ENABLE_HUSH_LOOPS
3183 [RES_FOR ] = "FOR" ,
3184 [RES_WHILE] = "WHILE",
3185 [RES_UNTIL] = "UNTIL",
3187 [RES_DONE ] = "DONE" ,
3189 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3192 #if ENABLE_HUSH_CASE
3193 [RES_CASE ] = "CASE" ,
3194 [RES_MATCH] = "MATCH",
3195 [RES_CASEI] = "CASEI",
3196 [RES_ESAC ] = "ESAC" ,
3198 [RES_XXXX ] = "XXXX" ,
3199 [RES_SNTX ] = "SNTX" ,
3201 static const char *const GRPTYPE[] = {
3204 #if ENABLE_HUSH_FUNCTIONS
3213 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3214 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3216 while (prn < pi->num_cmds) {
3217 struct command *command = &pi->cmds[prn];
3218 char **argv = command->argv;
3220 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3222 command->assignment_cnt);
3223 if (command->group) {
3224 fprintf(stderr, " group %s: (argv=%p)\n",
3225 GRPTYPE[command->grp_type],
3227 debug_print_tree(command->group, lvl+1);
3231 if (argv) while (*argv) {
3232 fprintf(stderr, " '%s'", *argv);
3235 fprintf(stderr, "\n");
3244 /* NB: called by pseudo_exec, and therefore must not modify any
3245 * global data until exec/_exit (we can be a child after vfork!) */
3246 static int run_list(struct pipe *pi)
3248 #if ENABLE_HUSH_CASE
3249 char *case_word = NULL;
3251 #if ENABLE_HUSH_LOOPS
3252 struct pipe *loop_top = NULL;
3253 char *for_varname = NULL;
3254 char **for_lcur = NULL;
3255 char **for_list = NULL;
3257 smallint last_followup;
3259 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3260 smalluint cond_code = 0;
3262 enum { cond_code = 0 };
3265 smallint rword; /* enum reserved_style */
3266 smallint last_rword; /* ditto */
3269 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3271 #if ENABLE_HUSH_LOOPS
3272 /* Check syntax for "for" */
3273 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3274 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3276 /* current word is FOR or IN (BOLD in comments below) */
3277 if (cpipe->next == NULL) {
3278 syntax("malformed for");
3279 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3282 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3283 if (cpipe->next->res_word == RES_DO)
3285 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3286 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3287 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3289 syntax("malformed for");
3290 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3296 /* Past this point, all code paths should jump to ret: label
3297 * in order to return, no direct "return" statements please.
3298 * This helps to ensure that no memory is leaked. */
3300 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3303 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3304 * We are saving state before entering outermost list ("while...done")
3305 * so that ctrl-Z will correctly background _entire_ outermost list,
3306 * not just a part of it (like "sleep 1 | exit 2") */
3307 if (++G.run_list_level == 1 && G_interactive_fd) {
3308 if (sigsetjmp(G.toplevel_jb, 1)) {
3309 /* ctrl-Z forked and we are parent; or ctrl-C.
3310 * Sighandler has longjmped us here */
3311 signal(SIGINT, SIG_IGN);
3312 signal(SIGTSTP, SIG_IGN);
3313 /* Restore level (we can be coming from deep inside
3315 G.run_list_level = 1;
3316 #if ENABLE_FEATURE_SH_STANDALONE
3317 if (G.nofork_save.saved) { /* if save area is valid */
3318 debug_printf_jobs("exiting nofork early\n");
3319 restore_nofork_data(&G.nofork_save);
3322 //// if (G.ctrl_z_flag) {
3323 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3324 //// * Remember this child as background job */
3325 //// insert_bg_job(pi);
3327 /* ctrl-C. We just stop doing whatever we were doing */
3330 USE_HUSH_LOOPS(loop_top = NULL;)
3331 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3335 //// /* ctrl-Z handler will store pid etc in pi */
3336 //// G.toplevel_list = pi;
3337 //// G.ctrl_z_flag = 0;
3338 #if ENABLE_FEATURE_SH_STANDALONE
3339 G.nofork_save.saved = 0; /* in case we will run a nofork later */
3341 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3342 //// signal(SIGINT, handler_ctrl_c);
3348 last_rword = RES_XXXX;
3350 last_followup = PIPE_SEQ;
3351 rcode = G.last_exitcode;
3353 /* Go through list of pipes, (maybe) executing them. */
3354 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3358 IF_HAS_KEYWORDS(rword = pi->res_word;)
3359 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3360 rword, cond_code, last_rword);
3361 #if ENABLE_HUSH_LOOPS
3362 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3363 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3365 /* start of a loop: remember where loop starts */
3370 /* Still in the same "if...", "then..." or "do..." branch? */
3371 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3372 if ((rcode == 0 && last_followup == PIPE_OR)
3373 || (rcode != 0 && last_followup == PIPE_AND)
3375 /* It is "<true> || CMD" or "<false> && CMD"
3376 * and we should not execute CMD */
3377 debug_printf_exec("skipped cmd because of || or &&\n");
3378 last_followup = pi->followup;
3382 last_followup = pi->followup;
3383 IF_HAS_KEYWORDS(last_rword = rword;)
3386 if (rword == RES_THEN) {
3387 /* if false; then ... fi has exitcode 0! */
3388 G.last_exitcode = rcode = EXIT_SUCCESS;
3389 /* "if <false> THEN cmd": skip cmd */
3393 if (rword == RES_ELSE || rword == RES_ELIF) {
3394 /* "if <true> then ... ELSE/ELIF cmd":
3395 * skip cmd and all following ones */
3400 #if ENABLE_HUSH_LOOPS
3401 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3403 /* first loop through for */
3405 static const char encoded_dollar_at[] ALIGN1 = {
3406 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3407 }; /* encoded representation of "$@" */
3408 static const char *const encoded_dollar_at_argv[] = {
3409 encoded_dollar_at, NULL
3410 }; /* argv list with one element: "$@" */
3413 vals = (char**)encoded_dollar_at_argv;
3414 if (pi->next->res_word == RES_IN) {
3415 /* if no variable values after "in" we skip "for" */
3416 if (!pi->next->cmds[0].argv) {
3417 G.last_exitcode = rcode = EXIT_SUCCESS;
3418 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3421 vals = pi->next->cmds[0].argv;
3422 } /* else: "for var; do..." -> assume "$@" list */
3423 /* create list of variable values */
3424 debug_print_strings("for_list made from", vals);
3425 for_list = expand_strvec_to_strvec(vals);
3426 for_lcur = for_list;
3427 debug_print_strings("for_list", for_list);
3428 for_varname = pi->cmds[0].argv[0];
3429 pi->cmds[0].argv[0] = NULL;
3431 free(pi->cmds[0].argv[0]);
3433 /* "for" loop is over, clean up */
3437 pi->cmds[0].argv[0] = for_varname;
3440 /* Insert next value from for_lcur */
3441 //TODO: does it need escaping?
3442 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3443 pi->cmds[0].assignment_cnt = 1;
3445 if (rword == RES_IN) {
3446 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3448 if (rword == RES_DONE) {
3449 continue; /* "done" has no cmds too */
3452 #if ENABLE_HUSH_CASE
3453 if (rword == RES_CASE) {
3454 case_word = expand_strvec_to_string(pi->cmds->argv);
3457 if (rword == RES_MATCH) {
3460 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3462 /* all prev words didn't match, does this one match? */
3463 argv = pi->cmds->argv;
3465 char *pattern = expand_string_to_string(*argv);
3466 /* TODO: which FNM_xxx flags to use? */
3467 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3469 if (cond_code == 0) { /* match! we will execute this branch */
3470 free(case_word); /* make future "word)" stop */
3478 if (rword == RES_CASEI) { /* inside of a case branch */
3480 continue; /* not matched yet, skip this pipe */
3483 /* Just pressing <enter> in shell should check for jobs.
3484 * OTOH, in non-interactive shell this is useless
3485 * and only leads to extra job checks */
3486 if (pi->num_cmds == 0) {
3487 if (G_interactive_fd)
3488 goto check_jobs_and_continue;
3492 /* After analyzing all keywords and conditions, we decided
3493 * to execute this pipe. NB: have to do checkjobs(NULL)
3494 * after run_pipe to collect any background children,
3495 * even if list execution is to be stopped. */
3496 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3499 #if ENABLE_HUSH_LOOPS
3500 G.flag_break_continue = 0;
3502 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3504 /* We only ran a builtin: rcode is already known
3505 * and we don't need to wait for anything. */
3506 G.last_exitcode = rcode;
3507 debug_printf_exec(": builtin exitcode %d\n", rcode);
3508 check_and_run_traps(0);
3509 #if ENABLE_HUSH_LOOPS
3510 /* Was it "break" or "continue"? */
3511 if (G.flag_break_continue) {
3512 smallint fbc = G.flag_break_continue;
3513 /* We might fall into outer *loop*,
3514 * don't want to break it too */
3516 G.depth_break_continue--;
3517 if (G.depth_break_continue == 0)
3518 G.flag_break_continue = 0;
3519 /* else: e.g. "continue 2" should *break* once, *then* continue */
3520 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3521 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3522 goto check_jobs_and_break;
3523 /* "continue": simulate end of loop */
3528 } else if (pi->followup == PIPE_BG) {
3529 /* What does bash do with attempts to background builtins? */
3530 /* even bash 3.2 doesn't do that well with nested bg:
3531 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3532 * I'm NOT treating inner &'s as jobs */
3533 check_and_run_traps(0);
3535 if (G.run_list_level == 1)
3538 G.last_exitcode = rcode = EXIT_SUCCESS;
3539 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3542 if (G.run_list_level == 1 && G_interactive_fd) {
3543 /* Waits for completion, then fg's main shell */
3544 rcode = checkjobs_and_fg_shell(pi);
3545 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3546 check_and_run_traps(0);
3549 { /* This one just waits for completion */
3550 rcode = checkjobs(pi);
3551 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3552 check_and_run_traps(0);
3554 G.last_exitcode = rcode;
3558 /* Analyze how result affects subsequent commands */
3560 if (rword == RES_IF || rword == RES_ELIF)
3563 #if ENABLE_HUSH_LOOPS
3564 /* Beware of "while false; true; do ..."! */
3565 if (pi->next && pi->next->res_word == RES_DO) {
3566 if (rword == RES_WHILE) {
3568 /* "while false; do...done" - exitcode 0 */
3569 G.last_exitcode = rcode = EXIT_SUCCESS;
3570 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3571 goto check_jobs_and_break;
3574 if (rword == RES_UNTIL) {
3576 debug_printf_exec(": until expr is true: breaking\n");
3577 check_jobs_and_break:
3585 check_jobs_and_continue:
3590 //// if (G.ctrl_z_flag) {
3591 //// /* ctrl-Z forked somewhere in the past, we are the child,
3592 //// * and now we completed running the list. Exit. */
3598 //// if (!G.run_list_level && G_interactive_fd) {
3599 //// signal(SIGTSTP, SIG_IGN);
3600 //// signal(SIGINT, SIG_IGN);
3603 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3604 #if ENABLE_HUSH_LOOPS
3609 #if ENABLE_HUSH_CASE
3615 /* Select which version we will use */
3616 static int run_and_free_list(struct pipe *pi)
3619 debug_printf_exec("run_and_free_list entered\n");
3621 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3622 rcode = run_list(pi);
3624 /* free_pipe_list has the side effect of clearing memory.
3625 * In the long run that function can be merged with run_list,
3626 * but doing that now would hobble the debugging effort. */
3627 free_pipe_list(pi, /* indent: */ 0);
3628 debug_printf_exec("run_and_free_list return %d\n", rcode);
3633 static struct pipe *new_pipe(void)
3636 pi = xzalloc(sizeof(struct pipe));
3637 /*pi->followup = 0; - deliberately invalid value */
3638 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3642 /* Command (member of a pipe) is complete. The only possible error here
3643 * is out of memory, in which case xmalloc exits. */
3644 static int done_command(struct parse_context *ctx)
3646 /* The command is really already in the pipe structure, so
3647 * advance the pipe counter and make a new, null command. */
3648 struct pipe *pi = ctx->pipe;
3649 struct command *command = ctx->command;
3652 if (command->group == NULL
3653 && command->argv == NULL
3654 && command->redirects == NULL
3656 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3657 memset(command, 0, sizeof(*command)); /* paranoia */
3658 return pi->num_cmds;
3661 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3662 //debug_print_tree(ctx->list_head, 20);
3664 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3667 /* Only real trickiness here is that the uncommitted
3668 * command structure is not counted in pi->num_cmds. */
3669 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3670 command = &pi->cmds[pi->num_cmds];
3671 memset(command, 0, sizeof(*command));
3673 ctx->command = command;
3674 /* but ctx->pipe and ctx->list_head remain unchanged */
3676 return pi->num_cmds; /* used only for 0/nonzero check */
3679 static void done_pipe(struct parse_context *ctx, pipe_style type)
3683 debug_printf_parse("done_pipe entered, followup %d\n", type);
3684 /* Close previous command */
3685 not_null = done_command(ctx);
3686 ctx->pipe->followup = type;
3688 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3689 ctx->ctx_inverted = 0;
3690 ctx->pipe->res_word = ctx->ctx_res_w;
3693 /* Without this check, even just <enter> on command line generates
3694 * tree of three NOPs (!). Which is harmless but annoying.
3695 * IOW: it is safe to do it unconditionally.
3696 * RES_NONE case is for "for a in; do ..." (empty IN set)
3697 * and other cases to work. */
3700 || ctx->ctx_res_w == RES_FI
3701 || ctx->ctx_res_w == RES_DONE
3702 || ctx->ctx_res_w == RES_FOR
3703 || ctx->ctx_res_w == RES_IN
3704 || ctx->ctx_res_w == RES_ESAC
3708 debug_printf_parse("done_pipe: adding new pipe: "
3709 "not_null:%d ctx->ctx_res_w:%d\n",
3710 not_null, ctx->ctx_res_w);
3712 ctx->pipe->next = new_p;
3714 /* RES_THEN, RES_DO etc are "sticky" -
3715 * they remain set for commands inside if/while.
3716 * This is used to control execution.
3717 * RES_FOR and RES_IN are NOT sticky (needed to support
3718 * cases where variable or value happens to match a keyword):
3720 #if ENABLE_HUSH_LOOPS
3721 if (ctx->ctx_res_w == RES_FOR
3722 || ctx->ctx_res_w == RES_IN)
3723 ctx->ctx_res_w = RES_NONE;
3725 #if ENABLE_HUSH_CASE
3726 if (ctx->ctx_res_w == RES_MATCH)
3727 ctx->ctx_res_w = RES_CASEI;
3729 ctx->command = NULL; /* trick done_command below */
3730 /* Create the memory for command, roughly:
3731 * ctx->pipe->cmds = new struct command;
3732 * ctx->command = &ctx->pipe->cmds[0];
3735 //debug_print_tree(ctx->list_head, 10);
3737 debug_printf_parse("done_pipe return\n");
3740 static void initialize_context(struct parse_context *ctx)
3742 memset(ctx, 0, sizeof(*ctx));
3743 ctx->pipe = ctx->list_head = new_pipe();
3744 /* Create the memory for command, roughly:
3745 * ctx->pipe->cmds = new struct command;
3746 * ctx->command = &ctx->pipe->cmds[0];
3751 /* If a reserved word is found and processed, parse context is modified
3752 * and 1 is returned.
3755 struct reserved_combo {
3758 unsigned char assignment_flag;
3762 FLAG_END = (1 << RES_NONE ),
3764 FLAG_IF = (1 << RES_IF ),
3765 FLAG_THEN = (1 << RES_THEN ),
3766 FLAG_ELIF = (1 << RES_ELIF ),
3767 FLAG_ELSE = (1 << RES_ELSE ),
3768 FLAG_FI = (1 << RES_FI ),
3770 #if ENABLE_HUSH_LOOPS
3771 FLAG_FOR = (1 << RES_FOR ),
3772 FLAG_WHILE = (1 << RES_WHILE),
3773 FLAG_UNTIL = (1 << RES_UNTIL),
3774 FLAG_DO = (1 << RES_DO ),
3775 FLAG_DONE = (1 << RES_DONE ),
3776 FLAG_IN = (1 << RES_IN ),
3778 #if ENABLE_HUSH_CASE
3779 FLAG_MATCH = (1 << RES_MATCH),
3780 FLAG_ESAC = (1 << RES_ESAC ),
3782 FLAG_START = (1 << RES_XXXX ),
3785 static const struct reserved_combo* match_reserved_word(o_string *word)
3787 /* Mostly a list of accepted follow-up reserved words.
3788 * FLAG_END means we are done with the sequence, and are ready
3789 * to turn the compound list into a command.
3790 * FLAG_START means the word must start a new compound list.
3792 static const struct reserved_combo reserved_list[] = {
3794 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3795 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3796 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3797 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3798 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3799 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3801 #if ENABLE_HUSH_LOOPS
3802 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3803 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3804 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3805 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3806 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3807 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3809 #if ENABLE_HUSH_CASE
3810 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3811 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3814 const struct reserved_combo *r;
3816 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3817 if (strcmp(word->data, r->literal) == 0)
3822 static int reserved_word(o_string *word, struct parse_context *ctx)
3824 #if ENABLE_HUSH_CASE
3825 static const struct reserved_combo reserved_match = {
3826 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3829 const struct reserved_combo *r;
3831 r = match_reserved_word(word);
3835 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3836 #if ENABLE_HUSH_CASE
3837 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3838 /* "case word IN ..." - IN part starts first match part */
3839 r = &reserved_match;
3842 if (r->flag == 0) { /* '!' */
3843 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3844 syntax("! ! command");
3845 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3847 ctx->ctx_inverted = 1;
3850 if (r->flag & FLAG_START) {
3851 struct parse_context *old;
3852 old = xmalloc(sizeof(*old));
3853 debug_printf_parse("push stack %p\n", old);
3854 *old = *ctx; /* physical copy */
3855 initialize_context(ctx);
3857 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3859 ctx->ctx_res_w = RES_SNTX;
3862 ctx->ctx_res_w = r->res;
3863 ctx->old_flag = r->flag;
3864 if (ctx->old_flag & FLAG_END) {
3865 struct parse_context *old;
3866 done_pipe(ctx, PIPE_SEQ);
3867 debug_printf_parse("pop stack %p\n", ctx->stack);
3869 old->command->group = ctx->list_head;
3870 old->command->grp_type = GRP_NORMAL;
3872 o_addstr(&old->as_string, ctx->as_string.data);
3873 o_free_unsafe(&ctx->as_string);
3874 old->command->group_as_string = xstrdup(old->as_string.data);
3875 debug_printf_parse("pop, remembering as:'%s'\n",
3876 old->command->group_as_string);
3878 *ctx = *old; /* physical copy */
3881 word->o_assignment = r->assignment_flag;
3886 /* Word is complete, look at it and update parsing context.
3887 * Normal return is 0. Syntax errors return 1.
3888 * Note: on return, word is reset, but not o_free'd!
3890 static int done_word(o_string *word, struct parse_context *ctx)
3892 struct command *command = ctx->command;
3894 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3895 if (word->length == 0 && word->o_quoted == 0) {
3896 debug_printf_parse("done_word return 0: true null, ignored\n");
3899 /* If this word wasn't an assignment, next ones definitely
3900 * can't be assignments. Even if they look like ones. */
3901 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3902 && word->o_assignment != WORD_IS_KEYWORD
3904 word->o_assignment = NOT_ASSIGNMENT;
3906 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3907 command->assignment_cnt++;
3908 word->o_assignment = MAYBE_ASSIGNMENT;
3911 if (ctx->pending_redirect) {
3912 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3913 * only if run as "bash", not "sh" */
3914 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3916 * ...the word that follows the redirection operator
3917 * shall be subjected to tilde expansion, parameter expansion,
3918 * command substitution, arithmetic expansion, and quote
3919 * removal. Pathname expansion shall not be performed
3920 * on the word by a non-interactive shell; an interactive
3921 * shell may perform it, but shall do so only when
3922 * the expansion would result in one word."
3924 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3925 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3928 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3930 word->o_assignment = NOT_ASSIGNMENT;
3931 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3933 /* "{ echo foo; } echo bar" - bad */
3934 /* NB: bash allows e.g.:
3935 * if true; then { echo foo; } fi
3936 * while if false; then false; fi do break; done
3938 * while if false; then false; fi; do; break; done
3940 if (command->group) {
3942 debug_printf_parse("done_word return 1: syntax error, "
3943 "groups and arglists don't mix\n");
3947 #if ENABLE_HUSH_CASE
3948 if (ctx->ctx_dsemicolon
3949 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3951 /* already done when ctx_dsemicolon was set to 1: */
3952 /* ctx->ctx_res_w = RES_MATCH; */
3953 ctx->ctx_dsemicolon = 0;
3956 if (!command->argv /* if it's the first word... */
3957 #if ENABLE_HUSH_LOOPS
3958 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3959 && ctx->ctx_res_w != RES_IN
3962 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3963 if (reserved_word(word, ctx)) {
3965 debug_printf_parse("done_word return %d\n",
3966 (ctx->ctx_res_w == RES_SNTX));
3967 return (ctx->ctx_res_w == RES_SNTX);
3971 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
3972 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3973 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3974 /* (otherwise it's known to be not empty and is already safe) */
3976 /* exclude "$@" - it can expand to no word despite "" */
3977 char *p = word->data;
3978 while (p[0] == SPECIAL_VAR_SYMBOL
3979 && (p[1] & 0x7f) == '@'
3980 && p[2] == SPECIAL_VAR_SYMBOL
3984 if (p == word->data || p[0] != '\0') {
3985 /* saw no "$@", or not only "$@" but some
3986 * real text is there too */
3987 /* insert "empty variable" reference, this makes
3988 * e.g. "", $empty"" etc to not disappear */
3989 o_addchr(word, SPECIAL_VAR_SYMBOL);
3990 o_addchr(word, SPECIAL_VAR_SYMBOL);
3993 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3994 debug_print_strings("word appended to argv", command->argv);
3998 ctx->pending_redirect = NULL;
4000 #if ENABLE_HUSH_LOOPS
4001 /* Force FOR to have just one word (variable name) */
4002 /* NB: basically, this makes hush see "for v in ..." syntax as if
4003 * as it is "for v; in ...". FOR and IN become two pipe structs
4005 if (ctx->ctx_res_w == RES_FOR) {
4006 //TODO: check that command->argv[0] is a valid variable name!
4007 done_pipe(ctx, PIPE_SEQ);
4010 #if ENABLE_HUSH_CASE
4011 /* Force CASE to have just one word */
4012 if (ctx->ctx_res_w == RES_CASE) {
4013 done_pipe(ctx, PIPE_SEQ);
4016 debug_printf_parse("done_word return 0\n");
4021 /* Peek ahead in the input to find out if we have a "&n" construct,
4022 * as in "2>&1", that represents duplicating a file descriptor.
4023 * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
4024 * -2 (syntax error), -1 if no & was seen, or the number found.
4027 #define redirect_dup_num(as_string, input) \
4028 redirect_dup_num(input)
4030 static int redirect_dup_num(o_string *as_string, struct in_str *input)
4038 ch = i_getch(input); /* get the & */
4039 nommu_addchr(as_string, ch);
4042 ch = i_getch(input);
4043 nommu_addchr(as_string, ch);
4044 return REDIRFD_CLOSE;
4048 while (ch != EOF && isdigit(ch)) {
4049 d = d*10 + (ch-'0');
4051 ch = i_getch(input);
4052 nommu_addchr(as_string, ch);
4057 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4059 bb_error_msg("ambiguous redirect");
4063 /* Return code is 0 normally, 1 if a syntax error is detected
4065 static int parse_redirect(struct parse_context *ctx,
4068 struct in_str *input)
4070 struct command *command = ctx->command;
4071 struct redir_struct *redir;
4072 struct redir_struct **redirp;
4076 if (style != REDIRECT_HEREDOC) {
4077 /* Check for a '2>&1' type redirect */
4078 dup_num = redirect_dup_num(&ctx->as_string, input);
4080 return 1; /* syntax error */
4082 int ch = i_peek(input);
4083 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4084 if (dup_num) { /* <<-... */
4085 ch = i_getch(input);
4086 nommu_addchr(&ctx->as_string, ch);
4089 /* <<[-] word is the same as <<[-]word */
4090 while (ch == ' ' || ch == '\t') {
4091 ch = i_getch(input);
4092 nommu_addchr(&ctx->as_string, ch);
4097 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
4098 int ch = i_peek(input);
4100 /* >|FILE redirect ("clobbering" >).
4101 * Since we do not support "set -o noclobber" yet,
4102 * >| and > are the same for now. Just eat |.
4104 ch = i_getch(input);
4105 nommu_addchr(&ctx->as_string, ch);
4109 /* Create a new redir_struct and append it to the linked list */
4110 redirp = &command->redirects;
4111 while ((redir = *redirp) != NULL) {
4112 redirp = &(redir->next);
4114 *redirp = redir = xzalloc(sizeof(*redir));
4115 /* redir->next = NULL; */
4116 /* redir->rd_filename = NULL; */
4117 redir->rd_type = style;
4118 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4120 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4121 redir_table[style].descrip);
4123 redir->rd_dup = dup_num;
4124 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4125 /* Erik had a check here that the file descriptor in question
4126 * is legit; I postpone that to "run time"
4127 * A "-" representation of "close me" shows up as a -3 here */
4128 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4129 redir->rd_fd, redir->rd_dup);
4131 /* Set ctx->pending_redirect, so we know what to do at the
4132 * end of the next parsed word. */
4133 ctx->pending_redirect = redir;
4138 /* If a redirect is immediately preceded by a number, that number is
4139 * supposed to tell which file descriptor to redirect. This routine
4140 * looks for such preceding numbers. In an ideal world this routine
4141 * needs to handle all the following classes of redirects...
4142 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4143 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4144 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4145 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4147 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4149 * ... If n is quoted, the number shall not be recognized as part of
4150 * the redirection expression. For example:
4152 * writes the character 2 into file a"
4153 * We are getting it right by setting ->o_quoted on any \<char>
4155 * A -1 return means no valid number was found,
4156 * the caller should use the appropriate default for this redirection.
4158 static int redirect_opt_num(o_string *o)
4162 if (o->data == NULL)
4164 num = bb_strtou(o->data, NULL, 10);
4165 if (errno || num < 0)
4172 #define fetch_till_str(as_string, input, word, skip_tabs) \
4173 fetch_till_str(input, word, skip_tabs)
4175 static char *fetch_till_str(o_string *as_string,
4176 struct in_str *input,
4180 o_string heredoc = NULL_O_STRING;
4186 ch = i_getch(input);
4187 nommu_addchr(as_string, ch);
4189 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4190 heredoc.data[past_EOL] = '\0';
4191 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4192 return heredoc.data;
4195 o_addchr(&heredoc, ch);
4196 past_EOL = heredoc.length;
4199 ch = i_getch(input);
4200 nommu_addchr(as_string, ch);
4201 } while (skip_tabs && ch == '\t');
4202 } while (ch == '\n');
4205 o_free_unsafe(&heredoc);
4208 o_addchr(&heredoc, ch);
4209 nommu_addchr(as_string, ch);
4213 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4214 * and load them all. There should be exactly heredoc_cnt of them.
4216 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4218 struct pipe *pi = ctx->list_head;
4222 struct command *cmd = pi->cmds;
4224 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4226 cmd->argv ? cmd->argv[0] : "NONE");
4227 for (i = 0; i < pi->num_cmds; i++) {
4228 struct redir_struct *redir = cmd->redirects;
4230 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4231 i, cmd->argv ? cmd->argv[0] : "NONE");
4233 if (redir->rd_type == REDIRECT_HEREDOC) {
4236 if (heredoc_cnt <= 0) {
4237 syntax("heredoc BUG 1");
4238 return 1; /* error */
4240 redir->rd_type = REDIRECT_HEREDOC2;
4241 /* redir->dup is (ab)used to indicate <<- */
4242 p = fetch_till_str(&ctx->as_string, input,
4243 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4245 syntax("unexpected EOF in here document");
4248 free(redir->rd_filename);
4249 redir->rd_filename = p;
4252 redir = redir->next;
4258 /* Should be 0. If it isn't, it's a parse error */
4260 syntax("heredoc BUG 2");
4266 #define parse_stream(pstring, input, end_trigger) \
4267 parse_stream(input, end_trigger)
4269 static struct pipe *parse_stream(char **pstring,
4270 struct in_str *input,
4272 static void parse_and_run_string(const char *s);
4274 #if ENABLE_HUSH_TICK
4275 static FILE *generate_stream_from_string(const char *s)
4278 int pid, channel[2];
4281 pid = BB_MMU ? fork() : vfork();
4283 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4285 if (pid == 0) { /* child */
4286 disable_restore_tty_pgrp_on_exit();
4287 /* Process substitution is not considered to be usual
4288 * 'command execution'.
4289 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4296 close(channel[0]); /* NB: close _first_, then move fd! */
4297 xmove_fd(channel[1], 1);
4298 /* Prevent it from trying to handle ctrl-z etc */
4299 USE_HUSH_JOB(G.run_list_level = 1;)
4301 reset_traps_to_defaults();
4302 parse_and_run_string(s);
4303 _exit(G.last_exitcode);
4305 /* We re-execute after vfork on NOMMU. This makes this script safe:
4306 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4307 * huge=`cat BIG` # was blocking here forever
4310 re_execute_shell(s, 0);
4315 enable_restore_tty_pgrp_on_exit();
4316 clean_up_after_re_execute();
4318 pf = fdopen(channel[0], "r");
4322 /* Return code is exit status of the process that is run. */
4323 static int process_command_subs(o_string *dest, const char *s)
4326 struct in_str pipe_str;
4329 pf = generate_stream_from_string(s);
4332 close_on_exec_on(fileno(pf));
4334 /* Now send results of command back into original context */
4335 setup_file_in_str(&pipe_str, pf);
4337 while ((ch = i_getch(&pipe_str)) != EOF) {
4343 o_addchr(dest, '\n');
4346 o_addQchr(dest, ch);
4349 debug_printf("done reading from pipe, pclose()ing\n");
4350 /* Note: we got EOF, and we just close the read end of the pipe.
4351 * We do not wait for the `cmd` child to terminate. bash and ash do.
4353 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4354 * `false`; echo $? - bash outputs "1"
4357 debug_printf("closed FILE from child. return 0\n");
4362 static int parse_group(o_string *dest, struct parse_context *ctx,
4363 struct in_str *input, int ch)
4365 /* dest contains characters seen prior to ( or {.
4366 * Typically it's empty, but for function defs,
4367 * it contains function name (without '()'). */
4368 struct pipe *pipe_list;
4370 struct command *command = ctx->command;
4372 debug_printf_parse("parse_group entered\n");
4373 #if ENABLE_HUSH_FUNCTIONS
4374 if (ch == 'F') { /* function definition? */
4375 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4376 //command->fname = dest->data;
4377 command->grp_type = GRP_FUNCTION;
4378 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4379 memset(dest, 0, sizeof(*dest));
4382 if (command->argv /* word [word](... */
4383 || dest->length /* word(... */
4384 || dest->o_quoted /* ""(... */
4387 debug_printf_parse("parse_group return 1: "
4388 "syntax error, groups and arglists don't mix\n");
4394 command->grp_type = GRP_SUBSHELL;
4398 char *as_string = NULL;
4400 pipe_list = parse_stream(&as_string, input, endch);
4403 o_addstr(&ctx->as_string, as_string);
4405 /* empty ()/{} or parse error? */
4406 if (!pipe_list || pipe_list == ERR_PTR) {
4411 debug_printf_parse("parse_group return 1: "
4412 "parse_stream returned %p\n", pipe_list);
4415 command->group = pipe_list;
4417 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4418 command->group_as_string = as_string;
4419 debug_printf_parse("end of group, remembering as:'%s'\n",
4420 command->group_as_string);
4423 debug_printf_parse("parse_group return 0\n");
4425 /* command remains "open", available for possible redirects */
4428 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4429 /* Subroutines for copying $(...) and `...` things */
4430 static int add_till_backquote(o_string *dest, struct in_str *input);
4432 static int add_till_single_quote(o_string *dest, struct in_str *input)
4435 int ch = i_getch(input);
4437 syntax("unterminated '");
4445 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4446 static int add_till_double_quote(o_string *dest, struct in_str *input)
4449 int ch = i_getch(input);
4451 syntax("unterminated \"");
4456 if (ch == '\\') { /* \x. Copy both chars. */
4458 ch = i_getch(input);
4462 if (add_till_backquote(dest, input))
4467 //if (ch == '$') ...
4470 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4472 * "Within the backquoted style of command substitution, backslash
4473 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4474 * The search for the matching backquote shall be satisfied by the first
4475 * backquote found without a preceding backslash; during this search,
4476 * if a non-escaped backquote is encountered within a shell comment,
4477 * a here-document, an embedded command substitution of the $(command)
4478 * form, or a quoted string, undefined results occur. A single-quoted
4479 * or double-quoted string that begins, but does not end, within the
4480 * "`...`" sequence produces undefined results."
4482 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4484 static int add_till_backquote(o_string *dest, struct in_str *input)
4487 int ch = i_getch(input);
4489 syntax("unterminated `");
4495 /* \x. Copy both chars unless it is \` */
4496 int ch2 = i_getch(input);
4498 syntax("unterminated `");
4501 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4508 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4509 * quoting and nested ()s.
4510 * "With the $(command) style of command substitution, all characters
4511 * following the open parenthesis to the matching closing parenthesis
4512 * constitute the command. Any valid shell script can be used for command,
4513 * except a script consisting solely of redirections which produces
4514 * unspecified results."
4516 * echo $(echo '(TEST)' BEST) (TEST) BEST
4517 * echo $(echo 'TEST)' BEST) TEST) BEST
4518 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4520 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4524 int ch = i_getch(input);
4526 syntax("unterminated )");
4535 if (i_peek(input) == ')') {
4543 if (add_till_single_quote(dest, input))
4549 if (add_till_double_quote(dest, input))
4555 /* \x. Copy verbatim. Important for \(, \) */
4556 ch = i_getch(input);
4558 syntax("unterminated )");
4567 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4569 /* Return code: 0 for OK, 1 for syntax error */
4571 #define handle_dollar(as_string, dest, input) \
4572 handle_dollar(dest, input)
4574 static int handle_dollar(o_string *as_string,
4576 struct in_str *input)
4579 int ch = i_peek(input); /* first character after the $ */
4580 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4582 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4584 ch = i_getch(input);
4585 nommu_addchr(as_string, ch);
4587 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4589 debug_printf_parse(": '%c'\n", ch);
4590 o_addchr(dest, ch | quote_mask);
4593 if (!isalnum(ch) && ch != '_')
4595 ch = i_getch(input);
4596 nommu_addchr(as_string, ch);
4598 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4599 } else if (isdigit(ch)) {
4601 ch = i_getch(input);
4602 nommu_addchr(as_string, ch);
4603 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4604 debug_printf_parse(": '%c'\n", ch);
4605 o_addchr(dest, ch | quote_mask);
4606 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4607 } else switch (ch) {
4609 case '!': /* last bg pid */
4610 case '?': /* last exit code */
4611 case '#': /* number of args */
4612 case '*': /* args */
4613 case '@': /* args */
4614 goto make_one_char_var;
4616 bool first_char, all_digits;
4618 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4619 ch = i_getch(input);
4620 nommu_addchr(as_string, ch);
4621 /* XXX maybe someone will try to escape the '}' */
4626 ch = i_getch(input);
4627 nommu_addchr(as_string, ch);
4633 /* ${#var}: length of var contents */
4635 else if (isdigit(ch)) {
4642 && ( (all_digits && !isdigit(ch))
4643 || (!all_digits && !isalnum(ch) && ch != '_')
4646 /* handle parameter expansions
4647 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4652 case ':': /* null modifier */
4653 if (expansion == 0) {
4654 debug_printf_parse(": null modifier\n");
4659 case '#': /* remove prefix */
4660 case '%': /* remove suffix */
4661 if (expansion == 0) {
4662 debug_printf_parse(": remove suffix/prefix\n");
4667 case '-': /* default value */
4668 case '=': /* assign default */
4669 case '+': /* alternative */
4670 case '?': /* error indicate */
4671 debug_printf_parse(": parameter expansion\n");
4676 syntax("unterminated ${name}");
4677 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4682 debug_printf_parse(": '%c'\n", ch);
4683 o_addchr(dest, ch | quote_mask);
4687 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4690 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4695 ch = i_getch(input);
4696 nommu_addchr(as_string, ch);
4697 # if ENABLE_SH_MATH_SUPPORT
4698 if (i_peek(input) == '(') {
4699 ch = i_getch(input);
4700 nommu_addchr(as_string, ch);
4701 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4702 o_addchr(dest, /*quote_mask |*/ '+');
4706 if (add_till_closing_paren(dest, input, true))
4710 o_addstr(as_string, dest->data + pos);
4711 o_addchr(as_string, ')');
4712 o_addchr(as_string, ')');
4715 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4719 # if ENABLE_HUSH_TICK
4720 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4721 o_addchr(dest, quote_mask | '`');
4725 if (add_till_closing_paren(dest, input, false))
4729 o_addstr(as_string, dest->data + pos);
4730 o_addchr(as_string, '`');
4733 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4739 ch = i_getch(input);
4740 nommu_addchr(as_string, ch);
4742 if (isalnum(ch)) { /* it's $_name or $_123 */
4748 /* $_ Shell or shell script name; or last cmd name */
4749 /* $- Option flags set by set builtin or shell options (-i etc) */
4751 o_addQchr(dest, '$');
4753 debug_printf_parse("handle_dollar return 0\n");
4758 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4759 parse_stream_dquoted(dest, input, dquote_end)
4761 static int parse_stream_dquoted(o_string *as_string,
4763 struct in_str *input,
4770 ch = i_getch(input);
4772 nommu_addchr(as_string, ch);
4773 if (ch == dquote_end) { /* may be only '"' or EOF */
4774 if (dest->o_assignment == NOT_ASSIGNMENT)
4775 dest->o_escape ^= 1;
4776 debug_printf_parse("parse_stream_dquoted return 0\n");
4779 /* note: can't move it above ch == dquote_end check! */
4781 syntax("unterminated \"");
4782 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4787 next = i_peek(input);
4789 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4790 ch, ch, dest->o_escape);
4794 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4798 * "The backslash retains its special meaning [in "..."]
4799 * only when followed by one of the following characters:
4800 * $, `, ", \, or <newline>. A double quote may be quoted
4801 * within double quotes by preceding it with a backslash.
4802 * If enabled, history expansion will be performed unless
4803 * an ! appearing in double quotes is escaped using
4804 * a backslash. The backslash preceding the ! is not removed."
4806 if (strchr("$`\"\\", next) != NULL) {
4807 o_addqchr(dest, i_getch(input));
4809 o_addqchr(dest, '\\');
4814 if (handle_dollar(as_string, dest, input) != 0) {
4815 debug_printf_parse("parse_stream_dquoted return 1: "
4816 "handle_dollar returned non-0\n");
4821 #if ENABLE_HUSH_TICK
4823 //int pos = dest->length;
4824 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4825 o_addchr(dest, 0x80 | '`');
4826 if (add_till_backquote(dest, input))
4828 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4829 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4833 o_addQchr(dest, ch);
4835 && (dest->o_assignment == MAYBE_ASSIGNMENT
4836 || dest->o_assignment == WORD_IS_KEYWORD)
4837 && is_assignment(dest->data)
4839 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4845 * Scan input until EOF or end_trigger char.
4846 * Return a list of pipes to execute, or NULL on EOF
4847 * or if end_trigger character is met.
4848 * On syntax error, exit is shell is not interactive,
4849 * reset parsing machinery and start parsing anew,
4850 * or return ERR_PTR.
4852 static struct pipe *parse_stream(char **pstring,
4853 struct in_str *input,
4856 struct parse_context ctx;
4857 o_string dest = NULL_O_STRING;
4861 /* Double-quote state is handled in the state variable is_in_dquote.
4862 * A single-quote triggers a bypass of the main loop until its mate is
4863 * found. When recursing, quote state is passed in via dest->o_escape.
4865 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4866 end_trigger ? : 'X');
4868 G.ifs = get_local_var_value("IFS");
4873 #if ENABLE_HUSH_INTERACTIVE
4874 input->promptmode = 0; /* PS1 */
4876 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4877 initialize_context(&ctx);
4882 const char *is_special;
4886 redir_type redir_style;
4889 /* dest.o_quoted = 1; - already is (see below) */
4890 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4893 /* We reached closing '"' */
4896 ch = i_getch(input);
4897 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4898 ch, ch, dest.o_escape);
4903 syntax("unterminated here document");
4906 if (done_word(&dest, &ctx)) {
4910 done_pipe(&ctx, PIPE_SEQ);
4912 /* If we got nothing... */
4913 // TODO: test script consisting of just "&"
4914 if (pi->num_cmds == 0
4915 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4917 free_pipe_list(pi, 0);
4920 debug_printf_parse("parse_stream return %p\n", pi);
4922 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4924 *pstring = ctx.as_string.data;
4926 o_free_unsafe(&ctx.as_string);
4930 nommu_addchr(&ctx.as_string, ch);
4931 is_ifs = strchr(G.ifs, ch);
4932 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4933 "\\$\"" USE_HUSH_TICK("`") /* always special */
4936 if (!is_special && !is_ifs) { /* ordinary char */
4937 o_addQchr(&dest, ch);
4938 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4939 || dest.o_assignment == WORD_IS_KEYWORD)
4941 && is_assignment(dest.data)
4943 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4949 if (done_word(&dest, &ctx)) {
4953 #if ENABLE_HUSH_CASE
4954 /* "case ... in <newline> word) ..." -
4955 * newlines are ignored (but ';' wouldn't be) */
4956 if (ctx.command->argv == NULL
4957 && ctx.ctx_res_w == RES_MATCH
4962 /* Treat newline as a command separator. */
4963 done_pipe(&ctx, PIPE_SEQ);
4964 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4966 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4971 dest.o_assignment = MAYBE_ASSIGNMENT;
4973 /* note: if (is_ifs) continue;
4974 * will still trigger for us */
4977 if (end_trigger && end_trigger == ch
4978 && (heredoc_cnt == 0 || end_trigger != ';')
4980 //TODO: disallow "{ cmd }" without semicolon
4982 /* This is technically valid:
4983 * { cat <<HERE; }; echo Ok
4988 * but we don't support this.
4989 * We require heredoc to be in enclosing {}/(),
4992 syntax("unterminated here document");
4995 if (done_word(&dest, &ctx)) {
4998 done_pipe(&ctx, PIPE_SEQ);
4999 dest.o_assignment = MAYBE_ASSIGNMENT;
5000 /* Do we sit outside of any if's, loops or case's? */
5002 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5004 debug_printf_parse("parse_stream return %p: "
5005 "end_trigger char found\n",
5009 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5011 *pstring = ctx.as_string.data;
5013 o_free_unsafe(&ctx.as_string);
5015 return ctx.list_head;
5021 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
5022 /* ch is a special char and thus this word
5023 * cannot be an assignment */
5024 dest.o_assignment = NOT_ASSIGNMENT;
5029 next = i_peek(input);
5034 if (dest.length == 0) {
5037 if (ch == EOF || ch == '\n')
5040 /* note: we do not add it to &ctx.as_string */
5042 nommu_addchr(&ctx.as_string, '\n');
5044 o_addQchr(&dest, ch);
5052 o_addchr(&dest, '\\');
5053 ch = i_getch(input);
5054 nommu_addchr(&ctx.as_string, ch);
5055 o_addchr(&dest, ch);
5056 /* Example: echo Hello \2>file
5057 * we need to know that word 2 is quoted */
5061 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5062 debug_printf_parse("parse_stream parse error: "
5063 "handle_dollar returned non-0\n");
5070 ch = i_getch(input);
5072 syntax("unterminated '");
5075 nommu_addchr(&ctx.as_string, ch);
5078 if (dest.o_assignment == NOT_ASSIGNMENT)
5079 o_addqchr(&dest, ch);
5081 o_addchr(&dest, ch);
5086 is_in_dquote ^= 1; /* invert */
5087 if (dest.o_assignment == NOT_ASSIGNMENT)
5090 #if ENABLE_HUSH_TICK
5095 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5096 o_addchr(&dest, '`');
5100 if (add_till_backquote(&dest, input))
5103 o_addstr(&ctx.as_string, dest.data + pos);
5104 o_addchr(&ctx.as_string, '`');
5106 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5107 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5112 redir_fd = redirect_opt_num(&dest);
5113 if (done_word(&dest, &ctx)) {
5116 redir_style = REDIRECT_OVERWRITE;
5118 redir_style = REDIRECT_APPEND;
5119 ch = i_getch(input);
5120 nommu_addchr(&ctx.as_string, ch);
5123 else if (next == '(') {
5124 syntax(">(process) not supported");
5128 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5132 redir_fd = redirect_opt_num(&dest);
5133 if (done_word(&dest, &ctx)) {
5136 redir_style = REDIRECT_INPUT;
5138 redir_style = REDIRECT_HEREDOC;
5140 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5141 ch = i_getch(input);
5142 nommu_addchr(&ctx.as_string, ch);
5143 } else if (next == '>') {
5144 redir_style = REDIRECT_IO;
5145 ch = i_getch(input);
5146 nommu_addchr(&ctx.as_string, ch);
5149 else if (next == '(') {
5150 syntax("<(process) not supported");
5154 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5158 #if ENABLE_HUSH_CASE
5161 if (done_word(&dest, &ctx)) {
5164 done_pipe(&ctx, PIPE_SEQ);
5165 #if ENABLE_HUSH_CASE
5166 /* Eat multiple semicolons, detect
5167 * whether it means something special */
5172 ch = i_getch(input);
5173 nommu_addchr(&ctx.as_string, ch);
5174 if (ctx.ctx_res_w == RES_CASEI) {
5175 ctx.ctx_dsemicolon = 1;
5176 ctx.ctx_res_w = RES_MATCH;
5182 /* We just finished a cmd. New one may start
5183 * with an assignment */
5184 dest.o_assignment = MAYBE_ASSIGNMENT;
5187 if (done_word(&dest, &ctx)) {
5191 ch = i_getch(input);
5192 nommu_addchr(&ctx.as_string, ch);
5193 done_pipe(&ctx, PIPE_AND);
5195 done_pipe(&ctx, PIPE_BG);
5199 if (done_word(&dest, &ctx)) {
5202 #if ENABLE_HUSH_CASE
5203 if (ctx.ctx_res_w == RES_MATCH)
5204 break; /* we are in case's "word | word)" */
5206 if (next == '|') { /* || */
5207 ch = i_getch(input);
5208 nommu_addchr(&ctx.as_string, ch);
5209 done_pipe(&ctx, PIPE_OR);
5211 /* we could pick up a file descriptor choice here
5212 * with redirect_opt_num(), but bash doesn't do it.
5213 * "echo foo 2| cat" yields "foo 2". */
5218 #if ENABLE_HUSH_CASE
5219 /* "case... in [(]word)..." - skip '(' */
5220 if (ctx.ctx_res_w == RES_MATCH
5221 && ctx.command->argv == NULL /* not (word|(... */
5222 && dest.length == 0 /* not word(... */
5223 && dest.o_quoted == 0 /* not ""(... */
5228 #if ENABLE_HUSH_FUNCTIONS
5229 if (dest.length != 0 /* not just () but word() */
5230 && dest.o_quoted == 0 /* not a"b"c() */
5231 && ctx.command->argv == NULL /* it's the first word */
5232 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5233 && i_peek(input) == ')'
5234 && !match_reserved_word(&dest)
5236 bb_error_msg("seems like a function definition");
5238 //if !BB_MMU o_addchr(&ctx.as_string...
5240 //TODO: do it properly.
5241 ch = i_getch(input);
5242 } while (ch == ' ' || ch == '\n');
5244 syntax("was expecting {");
5247 ch = 'F'; /* magic value */
5251 if (parse_group(&dest, &ctx, input, ch) != 0) {
5256 #if ENABLE_HUSH_CASE
5257 if (ctx.ctx_res_w == RES_MATCH)
5261 /* proper use of this character is caught by end_trigger:
5262 * if we see {, we call parse_group(..., end_trigger='}')
5263 * and it will match } earlier (not here). */
5264 syntax("unexpected } or )");
5268 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5274 struct parse_context *pctx;
5275 IF_HAS_KEYWORDS(struct parse_context *p2;)
5277 /* Clean up allocated tree.
5278 * Samples for finding leaks on syntax error recovery path.
5279 * Run them from interactive shell, watch pmap `pidof hush`.
5280 * while if false; then false; fi do break; done
5282 * while if false; then false; fi; do break; fi
5283 * Samples to catch leaks at execution:
5284 * while if (true | {true;}); then echo ok; fi; do break; done
5285 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5289 /* Update pipe/command counts,
5290 * otherwise freeing may miss some */
5291 done_pipe(pctx, PIPE_SEQ);
5292 debug_printf_clean("freeing list %p from ctx %p\n",
5293 pctx->list_head, pctx);
5294 debug_print_tree(pctx->list_head, 0);
5295 free_pipe_list(pctx->list_head, 0);
5296 debug_printf_clean("freed list %p\n", pctx->list_head);
5298 o_free_unsafe(&pctx->as_string);
5300 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5304 IF_HAS_KEYWORDS(pctx = p2;)
5305 } while (HAS_KEYWORDS && pctx);
5306 /* Free text, clear all dest fields */
5308 /* If we are not in top-level parse, we return,
5309 * our caller will propagate error.
5311 if (end_trigger != ';') {
5318 /* Discard cached input, force prompt */
5320 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5325 /* Executing from string: eval, sh -c '...'
5326 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5327 * end_trigger controls how often we stop parsing
5328 * NUL: parse all, execute, return
5329 * ';': parse till ';' or newline, execute, repeat till EOF
5331 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5334 struct pipe *pipe_list;
5336 pipe_list = parse_stream(NULL, inp, end_trigger);
5337 if (!pipe_list) /* EOF */
5339 debug_print_tree(pipe_list, 0);
5340 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5341 run_and_free_list(pipe_list);
5345 static void parse_and_run_string(const char *s)
5347 struct in_str input;
5348 setup_string_in_str(&input, s);
5349 parse_and_run_stream(&input, '\0');
5352 static void parse_and_run_file(FILE *f)
5354 struct in_str input;
5355 setup_file_in_str(&input, f);
5356 parse_and_run_stream(&input, ';');
5359 /* Called a few times only (or even once if "sh -c") */
5360 static void block_signals(int second_time)
5365 mask = (1 << SIGQUIT);
5366 if (G_interactive_fd) {
5370 //TODO | (1 << SIGHUP)
5372 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5377 G.non_DFL_mask = mask;
5380 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5384 sigaddset(&G.blocked_set, sig);
5388 sigdelset(&G.blocked_set, SIGCHLD);
5390 sigprocmask(SIG_SETMASK, &G.blocked_set,
5391 second_time ? NULL : &G.inherited_set);
5392 /* POSIX allows shell to re-enable SIGCHLD
5393 * even if it was SIG_IGN on entry */
5394 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5396 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5401 static void maybe_set_to_sigexit(int sig)
5403 void (*handler)(int);
5404 /* non_DFL_mask'ed signals are, well, masked,
5405 * no need to set handler for them.
5407 if (!((G.non_DFL_mask >> sig) & 1)) {
5408 handler = signal(sig, sigexit);
5409 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5410 signal(sig, handler);
5413 /* Set handlers to restore tty pgrp and exit */
5414 static void set_fatal_handlers(void)
5416 /* We _must_ restore tty pgrp on fatal signals */
5418 maybe_set_to_sigexit(SIGILL );
5419 maybe_set_to_sigexit(SIGFPE );
5420 maybe_set_to_sigexit(SIGBUS );
5421 maybe_set_to_sigexit(SIGSEGV);
5422 maybe_set_to_sigexit(SIGTRAP);
5423 } /* else: hush is perfect. what SEGV? */
5424 maybe_set_to_sigexit(SIGABRT);
5425 /* bash 3.2 seems to handle these just like 'fatal' ones */
5426 maybe_set_to_sigexit(SIGPIPE);
5427 maybe_set_to_sigexit(SIGALRM);
5428 //TODO: disable and move down when proper SIGHUP handling is added
5429 maybe_set_to_sigexit(SIGHUP );
5430 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5431 * if we aren't interactive... but in this case
5432 * we never want to restore pgrp on exit, and this fn is not called */
5433 /*maybe_set_to_sigexit(SIGTERM);*/
5434 /*maybe_set_to_sigexit(SIGINT );*/
5438 static int set_mode(const char cstate, const char mode)
5440 int state = (cstate == '-' ? 1 : 0);
5442 case 'n': G.fake_mode = state; break;
5443 case 'x': /*G.debug_mode = state;*/ break;
5444 default: return EXIT_FAILURE;
5446 return EXIT_SUCCESS;
5449 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5450 int hush_main(int argc, char **argv)
5452 static const struct variable const_shell_ver = {
5454 .varstr = (char*)hush_version_str,
5455 .max_len = 1, /* 0 can provoke free(name) */
5459 int signal_mask_is_inited = 0;
5462 struct variable *cur_var;
5465 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5466 G.last_exitcode = EXIT_SUCCESS;
5468 G.argv0_for_re_execing = argv[0];
5470 /* Deal with HUSH_VERSION */
5471 G.shell_ver = const_shell_ver; /* copying struct here */
5472 G.top_var = &G.shell_ver;
5473 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5474 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5475 /* Initialize our shell local variables with the values
5476 * currently living in the environment */
5477 cur_var = G.top_var;
5480 char *value = strchr(*e, '=');
5481 if (value) { /* paranoia */
5482 cur_var->next = xzalloc(sizeof(*cur_var));
5483 cur_var = cur_var->next;
5484 cur_var->varstr = *e;
5485 cur_var->max_len = strlen(*e);
5486 cur_var->flg_export = 1;
5490 debug_printf_env("putenv '%s'\n", hush_version_str);
5491 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5492 #if ENABLE_FEATURE_EDITING
5493 G.line_input_state = new_line_input_t(FOR_SHELL);
5495 G.global_argc = argc;
5496 G.global_argv = argv;
5497 /* Initialize some more globals to non-zero values */
5499 #if ENABLE_HUSH_INTERACTIVE
5500 if (ENABLE_FEATURE_EDITING)
5501 cmdedit_set_initial_prompt();
5505 /* Shell is non-interactive at first. We need to call
5506 * block_signals(0) if we are going to execute "sh <script>",
5507 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5508 * If we later decide that we are interactive, we run block_signals(0)
5509 * (or re-run block_signals(1) if we ran block_signals(0) before)
5510 * in order to intercept (more) signals.
5514 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5516 opt = getopt(argc, argv, "c:xins"
5526 G.root_pid = getpid();
5527 G.global_argv = argv + optind;
5528 if (!argv[optind]) {
5529 /* -c 'script' (no params): prevent empty $0 */
5530 *--G.global_argv = argv[0];
5532 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5533 G.global_argc = argc - optind;
5534 block_signals(0); /* 0: called 1st time */
5535 parse_and_run_string(optarg);
5538 /* Well, we cannot just declare interactiveness,
5539 * we have to have some stuff (ctty, etc) */
5540 /* G_interactive_fd++; */
5543 /* "-s" means "read from stdin", but this is how we always
5544 * operate, so simply do nothing here. */
5547 case '<': /* "big heredoc" support */
5548 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5551 G.root_pid = bb_strtou(optarg, &optarg, 16);
5553 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5555 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5556 # if ENABLE_HUSH_LOOPS
5558 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5563 set_local_var(xstrdup(optarg), 0, opt == 'R');
5568 if (!set_mode('-', opt))
5572 fprintf(stderr, "Usage: sh [FILE]...\n"
5573 " or: sh -c command [args]...\n\n");
5579 } /* option parsing loop */
5582 G.root_pid = getpid();
5584 /* If we are login shell... */
5585 if (argv[0] && argv[0][0] == '-') {
5587 /* XXX what should argv be while sourcing /etc/profile? */
5588 debug_printf("sourcing /etc/profile\n");
5589 input = fopen_for_read("/etc/profile");
5590 if (input != NULL) {
5591 close_on_exec_on(fileno(input));
5592 block_signals(0); /* 0: called 1st time */
5593 signal_mask_is_inited = 1;
5594 parse_and_run_file(input);
5597 /* bash: after sourcing /etc/profile,
5598 * tries to source (in the given order):
5599 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5600 * stopping of first found. --noprofile turns this off.
5601 * bash also sources ~/.bash_logout on exit.
5602 * If called as sh, skips .bash_XXX files.
5609 * "bash <script>" (which is never interactive (unless -i?))
5610 * sources $BASH_ENV here (without scanning $PATH).
5611 * If called as sh, does the same but with $ENV.
5613 debug_printf("running script '%s'\n", argv[optind]);
5614 G.global_argv = argv + optind;
5615 G.global_argc = argc - optind;
5616 input = xfopen_for_read(argv[optind]);
5617 close_on_exec_on(fileno(input));
5618 if (!signal_mask_is_inited)
5619 block_signals(0); /* 0: called 1st time */
5620 parse_and_run_file(input);
5621 #if ENABLE_FEATURE_CLEAN_UP
5627 /* Up to here, shell was non-interactive. Now it may become one.
5628 * NB: don't forget to (re)run block_signals(0/1) as needed.
5631 /* A shell is interactive if the '-i' flag was given, or if all of
5632 * the following conditions are met:
5634 * no arguments remaining or the -s flag given
5635 * standard input is a terminal
5636 * standard output is a terminal
5637 * Refer to Posix.2, the description of the 'sh' utility.
5640 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5641 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5642 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5643 //TODO: "interactive" and "have job control" are two different things.
5644 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5645 //should stay on! Currently, we mix these into one.
5646 if (G.saved_tty_pgrp >= 0) {
5647 /* try to dup stdin to high fd#, >= 255 */
5648 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5649 if (G_interactive_fd < 0) {
5650 /* try to dup to any fd */
5651 G_interactive_fd = dup(STDIN_FILENO);
5652 if (G_interactive_fd < 0)
5654 G_interactive_fd = 0;
5656 // TODO: track & disallow any attempts of user
5657 // to (inadvertently) close/redirect it
5660 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5661 if (G_interactive_fd) {
5664 /* We are indeed interactive shell, and we will perform
5665 * job control. Setting up for that. */
5667 close_on_exec_on(G_interactive_fd);
5668 /* If we were run as 'hush &', sleep until we are
5669 * in the foreground (tty pgrp == our pgrp).
5670 * If we get started under a job aware app (like bash),
5671 * make sure we are now in charge so we don't fight over
5672 * who gets the foreground */
5674 shell_pgrp = getpgrp();
5675 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5676 if (G.saved_tty_pgrp == shell_pgrp)
5678 /* send TTIN to ourself (should stop us) */
5679 kill(- shell_pgrp, SIGTTIN);
5681 /* Block some signals */
5682 block_signals(signal_mask_is_inited);
5683 /* Set other signals to restore saved_tty_pgrp */
5684 set_fatal_handlers();
5685 /* Put ourselves in our own process group */
5686 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5687 /* Grab control of the terminal */
5688 tcsetpgrp(G_interactive_fd, getpid());
5689 /* -1 is special - makes xfuncs longjmp, not exit
5690 * (we reset die_sleep = 0 whereever we [v]fork) */
5691 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5692 if (setjmp(die_jmp)) {
5693 /* xfunc has failed! die die die */
5694 /* no EXIT traps, this is an escape hatch! */
5696 hush_exit(xfunc_error_retval);
5698 } else if (!signal_mask_is_inited) {
5699 block_signals(0); /* 0: called 1st time */
5700 } /* else: block_signals(0) was done before */
5701 #elif ENABLE_HUSH_INTERACTIVE
5702 /* No job control compiled in, only prompt/line editing */
5703 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5704 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5705 if (G_interactive_fd < 0) {
5706 /* try to dup to any fd */
5707 G_interactive_fd = dup(STDIN_FILENO);
5708 if (G_interactive_fd < 0)
5710 G_interactive_fd = 0;
5713 if (G_interactive_fd) {
5714 close_on_exec_on(G_interactive_fd);
5715 block_signals(signal_mask_is_inited);
5716 } else if (!signal_mask_is_inited) {
5720 /* We have interactiveness code disabled */
5721 if (!signal_mask_is_inited) {
5726 * if interactive but not a login shell, sources ~/.bashrc
5727 * (--norc turns this off, --rcfile <file> overrides)
5730 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5731 printf("\n\n%s hush - the humble shell\n", bb_banner);
5732 printf("Enter 'help' for a list of built-in commands.\n\n");
5735 parse_and_run_file(stdin);
5738 #if ENABLE_FEATURE_CLEAN_UP
5739 if (G.cwd != bb_msg_unknown)
5741 cur_var = G.top_var->next;
5743 struct variable *tmp = cur_var;
5744 if (!cur_var->max_len)
5745 free(cur_var->varstr);
5746 cur_var = cur_var->next;
5750 hush_exit(G.last_exitcode);
5755 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5756 int lash_main(int argc, char **argv)
5758 //bb_error_msg("lash is deprecated, please use hush instead");
5759 return hush_main(argc, argv);
5767 static int builtin_trap(char **argv)
5774 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5778 /* No args: print all trapped. This isn't 100% correct as we
5779 * should be escaping the cmd so that it can be pasted back in
5781 for (i = 0; i < NSIG; ++i)
5783 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5784 return EXIT_SUCCESS;
5789 /* If first arg is decimal: reset all specified signals */
5790 sig = bb_strtou(*argv, NULL, 10);
5796 sig = get_signum(*argv++);
5797 if (sig < 0 || sig >= NSIG) {
5799 /* Mimic bash message exactly */
5800 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5805 G.traps[sig] = xstrdup(new_cmd);
5807 debug_printf("trap: setting SIG%s (%i) to '%s'",
5808 get_signame(sig), sig, G.traps[sig]);
5810 /* There is no signal for 0 (EXIT) */
5815 sigaddset(&G.blocked_set, sig);
5817 /* There was a trap handler, we are removing it
5818 * (if sig has non-DFL handling,
5819 * we don't need to do anything) */
5820 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5822 sigdelset(&G.blocked_set, sig);
5824 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5829 /* First arg is "-": reset all specified to default */
5830 /* First arg is "": ignore all specified */
5831 /* Everything else: execute first arg upon signal */
5833 bb_error_msg("trap: invalid arguments");
5834 return EXIT_FAILURE;
5836 if (NOT_LONE_DASH(*argv))
5842 static int builtin_true(char **argv UNUSED_PARAM)
5847 static int builtin_test(char **argv)
5854 return test_main(argc, argv - argc);
5857 static int builtin_echo(char **argv)
5864 return echo_main(argc, argv - argc);
5867 static int builtin_eval(char **argv)
5869 int rcode = EXIT_SUCCESS;
5872 char *str = expand_strvec_to_string(argv);
5874 * eval "echo Hi; done" ("done" is syntax error):
5875 * "echo Hi" will not execute too.
5877 parse_and_run_string(str);
5879 rcode = G.last_exitcode;
5884 static int builtin_cd(char **argv)
5886 const char *newdir = argv[1];
5887 if (newdir == NULL) {
5888 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5889 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5891 newdir = getenv("HOME") ? : "/";
5893 if (chdir(newdir)) {
5894 /* Mimic bash message exactly */
5895 bb_perror_msg("cd: %s", newdir);
5896 return EXIT_FAILURE;
5899 return EXIT_SUCCESS;
5902 static int builtin_exec(char **argv)
5904 if (*++argv == NULL)
5905 return EXIT_SUCCESS; /* bash does this */
5910 // FIXME: if exec fails, bash does NOT exit! We do...
5911 pseudo_exec_argv(&dummy, argv, 0, NULL);
5916 static int builtin_exit(char **argv)
5918 debug_printf_exec("%s()\n", __func__);
5919 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5920 //puts("exit"); /* bash does it */
5921 // TODO: warn if we have background jobs: "There are stopped jobs"
5922 // On second consecutive 'exit', exit anyway.
5923 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
5925 /* note: EXIT trap is run by hush_exit */
5926 if (*++argv == NULL)
5927 hush_exit(G.last_exitcode);
5928 /* mimic bash: exit 123abc == exit 255 + error msg */
5929 xfunc_error_retval = 255;
5930 /* bash: exit -2 == exit 254, no error msg */
5931 hush_exit(xatoi(*argv) & 0xff);
5934 static int builtin_export(char **argv)
5936 if (*++argv == NULL) {
5938 // ash emits: export VAR='VAL'
5939 // bash: declare -x VAR="VAL"
5940 // (both also escape as needed (quotes, $, etc))
5945 return EXIT_SUCCESS;
5952 value = strchr(name, '=');
5954 /* They are exporting something without a =VALUE */
5955 struct variable *var;
5957 var = get_local_var(name);
5959 var->flg_export = 1;
5960 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5961 putenv(var->varstr);
5963 /* bash does not return an error when trying to export
5964 * an undefined variable. Do likewise. */
5967 set_local_var(xstrdup(name), 1, 0);
5970 return EXIT_SUCCESS;
5974 /* built-in 'fg' and 'bg' handler */
5975 static int builtin_fg_bg(char **argv)
5980 if (!G_interactive_fd)
5981 return EXIT_FAILURE;
5982 /* If they gave us no args, assume they want the last backgrounded task */
5984 for (pi = G.job_list; pi; pi = pi->next) {
5985 if (pi->jobid == G.last_jobid) {
5989 bb_error_msg("%s: no current job", argv[0]);
5990 return EXIT_FAILURE;
5992 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5993 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5994 return EXIT_FAILURE;
5996 for (pi = G.job_list; pi; pi = pi->next) {
5997 if (pi->jobid == jobnum) {
6001 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6002 return EXIT_FAILURE;
6004 // TODO: bash prints a string representation
6005 // of job being foregrounded (like "sleep 1 | cat")
6006 if (argv[0][0] == 'f') {
6007 /* Put the job into the foreground. */
6008 tcsetpgrp(G_interactive_fd, pi->pgrp);
6011 /* Restart the processes in the job */
6012 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6013 for (i = 0; i < pi->num_cmds; i++) {
6014 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6015 pi->cmds[i].is_stopped = 0;
6017 pi->stopped_cmds = 0;
6019 i = kill(- pi->pgrp, SIGCONT);
6021 if (errno == ESRCH) {
6022 delete_finished_bg_job(pi);
6023 return EXIT_SUCCESS;
6025 bb_perror_msg("kill (SIGCONT)");
6028 if (argv[0][0] == 'f') {
6030 return checkjobs_and_fg_shell(pi);
6032 return EXIT_SUCCESS;
6036 #if ENABLE_HUSH_HELP
6037 static int builtin_help(char **argv UNUSED_PARAM)
6039 const struct built_in_command *x;
6042 "Built-in commands:\n"
6043 "------------------\n");
6044 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6045 printf("%s\t%s\n", x->cmd, x->descr);
6048 return EXIT_SUCCESS;
6053 static int builtin_jobs(char **argv UNUSED_PARAM)
6056 const char *status_string;
6058 for (job = G.job_list; job; job = job->next) {
6059 if (job->alive_cmds == job->stopped_cmds)
6060 status_string = "Stopped";
6062 status_string = "Running";
6064 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6066 return EXIT_SUCCESS;
6071 static int builtin_memleak(char **argv UNUSED_PARAM)
6076 /* Crude attempt to find where "free memory" starts,
6077 * sans fragmentation. */
6079 l = (unsigned long)p;
6082 if (l < (unsigned long)p) l = (unsigned long)p;
6085 if (!G.memleak_value)
6086 G.memleak_value = l;
6088 l -= G.memleak_value;
6095 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6100 static int builtin_pwd(char **argv UNUSED_PARAM)
6103 return EXIT_SUCCESS;
6106 static int builtin_read(char **argv)
6109 const char *name = argv[1] ? argv[1] : "REPLY";
6110 //TODO: check that argv[1] is a valid variable name
6112 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6113 return set_local_var(string, 0, 0);
6116 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6117 * built-in 'set' handler
6119 * set [-abCefhmnuvx] [-o option] [argument...]
6120 * set [+abCefhmnuvx] [+o option] [argument...]
6121 * set -- [argument...]
6124 * Implementations shall support the options in both their hyphen and
6125 * plus-sign forms. These options can also be specified as options to sh.
6127 * Write out all variables and their values: set
6128 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6129 * Turn on the -x and -v options: set -xv
6130 * Unset all positional parameters: set --
6131 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6132 * Set the positional parameters to the expansion of x, even if x expands
6133 * with a leading '-' or '+': set -- $x
6135 * So far, we only support "set -- [argument...]" and some of the short names.
6137 static int builtin_set(char **argv)
6140 char **pp, **g_argv;
6141 char *arg = *++argv;
6145 for (e = G.top_var; e; e = e->next)
6147 return EXIT_SUCCESS;
6151 if (!strcmp(arg, "--")) {
6156 if (arg[0] == '+' || arg[0] == '-') {
6157 for (n = 1; arg[n]; ++n)
6158 if (set_mode(arg[0], arg[n]))
6164 } while ((arg = *++argv) != NULL);
6165 /* Now argv[0] is 1st argument */
6167 /* Only reset global_argv if we didn't process anything */
6169 return EXIT_SUCCESS;
6172 /* NB: G.global_argv[0] ($0) is never freed/changed */
6173 g_argv = G.global_argv;
6174 if (G.global_args_malloced) {
6180 G.global_args_malloced = 1;
6181 pp = xzalloc(sizeof(pp[0]) * 2);
6182 pp[0] = g_argv[0]; /* retain $0 */
6185 /* This realloc's G.global_argv */
6186 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6193 return EXIT_SUCCESS;
6195 /* Nothing known, so abort */
6197 bb_error_msg("set: %s: invalid option", arg);
6198 return EXIT_FAILURE;
6201 static int builtin_shift(char **argv)
6207 if (n >= 0 && n < G.global_argc) {
6208 if (G.global_args_malloced) {
6211 free(G.global_argv[m++]);
6214 memmove(&G.global_argv[1], &G.global_argv[n+1],
6215 G.global_argc * sizeof(G.global_argv[0]));
6216 return EXIT_SUCCESS;
6218 return EXIT_FAILURE;
6221 static int builtin_source(char **argv)
6225 if (*++argv == NULL)
6226 return EXIT_FAILURE;
6228 /* XXX search through $PATH is missing */
6229 input = fopen_or_warn(*argv, "r");
6231 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6232 return EXIT_FAILURE;
6234 close_on_exec_on(fileno(input));
6236 /* Now run the file */
6238 /* XXX argv and argc are broken; need to save old G.global_argv
6239 * (pointer only is OK!) on this stack frame,
6240 * set G.global_argv=argv+1, recurse, and restore. */
6241 parse_and_run_file(input);
6243 return G.last_exitcode;
6246 static int builtin_umask(char **argv)
6249 const char *arg = argv[1];
6251 //TODO: umask may take chmod-like symbolic masks
6252 new_umask = bb_strtou(arg, NULL, 8);
6254 //Message? bash examples:
6255 //bash: umask: 'q': invalid symbolic mode operator
6256 //bash: umask: 999: octal number out of range
6257 return EXIT_FAILURE;
6260 new_umask = umask(0);
6261 printf("%.3o\n", (unsigned) new_umask);
6262 /* fall through and restore new_umask which we set to 0 */
6265 return EXIT_SUCCESS;
6268 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6269 static int builtin_unset(char **argv)
6275 return EXIT_SUCCESS;
6278 if (argv[0][0] == '-') {
6279 switch (argv[0][1]) {
6285 bb_error_msg("unset: %s: invalid option", *argv);
6286 return EXIT_FAILURE;
6288 //TODO: disallow "unset -vf ..." too
6295 if (unset_local_var(*argv)) {
6296 /* unset <nonexistent_var> doesn't fail.
6297 * Error is when one tries to unset RO var.
6298 * Message was printed by unset_local_var. */
6302 #if ENABLE_HUSH_FUNCTIONS
6304 unset_local_func(*argv);
6312 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6313 static int builtin_wait(char **argv)
6315 int ret = EXIT_SUCCESS;
6318 if (*++argv == NULL) {
6319 /* Don't care about wait results */
6320 /* Note 1: must wait until there are no more children */
6321 /* Note 2: must be interruptible */
6323 * $ sleep 3 & sleep 6 & wait
6328 * $ sleep 3 & sleep 6 & wait
6332 * ^C <-- after ~4 sec from keyboard
6335 sigaddset(&G.blocked_set, SIGCHLD);
6336 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6339 if (errno == ECHILD)
6341 /* Wait for SIGCHLD or any other signal of interest */
6342 /* sigtimedwait with infinite timeout: */
6343 sig = sigwaitinfo(&G.blocked_set, NULL);
6345 sig = check_and_run_traps(sig);
6346 if (sig && sig != SIGCHLD) { /* see note 2 */
6352 sigdelset(&G.blocked_set, SIGCHLD);
6353 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6357 /* This is probably buggy wrt interruptible-ness */
6359 pid_t pid = bb_strtou(*argv, NULL, 10);
6361 /* mimic bash message */
6362 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6363 return EXIT_FAILURE;
6365 if (waitpid(pid, &status, 0) == pid) {
6366 if (WIFSIGNALED(status))
6367 ret = 128 + WTERMSIG(status);
6368 else if (WIFEXITED(status))
6369 ret = WEXITSTATUS(status);
6373 bb_perror_msg("wait %s", *argv);
6382 #if ENABLE_HUSH_LOOPS
6383 static int builtin_break(char **argv)
6385 if (G.depth_of_loop == 0) {
6386 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6387 return EXIT_SUCCESS; /* bash compat */
6389 G.flag_break_continue++; /* BC_BREAK = 1 */
6390 G.depth_break_continue = 1;
6392 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6393 if (errno || !G.depth_break_continue || argv[2]) {
6394 bb_error_msg("%s: bad arguments", argv[0]);
6395 G.flag_break_continue = BC_BREAK;
6396 G.depth_break_continue = UINT_MAX;
6399 if (G.depth_of_loop < G.depth_break_continue)
6400 G.depth_break_continue = G.depth_of_loop;
6401 return EXIT_SUCCESS;
6404 static int builtin_continue(char **argv)
6406 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6407 return builtin_break(argv);