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 /* These four support $?, $#, and $1 */
517 smalluint last_exitcode;
518 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
519 smalluint global_args_malloced;
520 /* how many non-NULL argv's we have. NB: $# + 1 */
524 char *argv0_for_re_execing;
525 char **argv_from_re_execing;
527 #if ENABLE_HUSH_LOOPS
528 unsigned depth_break_continue;
529 unsigned depth_of_loop;
533 struct variable *top_var; /* = &G.shell_ver (set in main()) */
534 struct variable shell_ver;
535 /* Signal and trap handling */
536 // unsigned count_SIGCHLD;
537 // unsigned handled_SIGCHLD;
538 /* which signals have non-DFL handler (even with no traps set)? */
539 unsigned non_DFL_mask;
540 char **traps; /* char *traps[NSIG] */
541 sigset_t blocked_set;
542 sigset_t inherited_set;
544 unsigned long memleak_value;
546 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
547 #if ENABLE_FEATURE_SH_STANDALONE
548 struct nofork_save_area nofork_save;
551 sigjmp_buf toplevel_jb;
554 #define G (*ptr_to_globals)
555 /* Not #defining name to G.name - this quickly gets unwieldy
556 * (too many defines). Also, I actually prefer to see when a variable
557 * is global, thus "G." prefix is a useful hint */
558 #define INIT_G() do { \
559 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
563 /* Function prototypes for builtins */
564 static int builtin_cd(char **argv);
565 static int builtin_echo(char **argv);
566 static int builtin_eval(char **argv);
567 static int builtin_exec(char **argv);
568 static int builtin_exit(char **argv);
569 static int builtin_export(char **argv);
571 static int builtin_fg_bg(char **argv);
572 static int builtin_jobs(char **argv);
575 static int builtin_help(char **argv);
578 static int builtin_memleak(char **argv);
580 static int builtin_pwd(char **argv);
581 static int builtin_read(char **argv);
582 static int builtin_set(char **argv);
583 static int builtin_shift(char **argv);
584 static int builtin_source(char **argv);
585 static int builtin_test(char **argv);
586 static int builtin_trap(char **argv);
587 static int builtin_true(char **argv);
588 static int builtin_umask(char **argv);
589 static int builtin_unset(char **argv);
590 static int builtin_wait(char **argv);
591 #if ENABLE_HUSH_LOOPS
592 static int builtin_break(char **argv);
593 static int builtin_continue(char **argv);
596 /* Table of built-in functions. They can be forked or not, depending on
597 * context: within pipes, they fork. As simple commands, they do not.
598 * When used in non-forking context, they can change global variables
599 * in the parent shell process. If forked, of course they cannot.
600 * For example, 'unset foo | whatever' will parse and run, but foo will
601 * still be set at the end. */
602 struct built_in_command {
604 int (*function)(char **argv);
607 #define BLTIN(cmd, func, help) { cmd, func, help }
609 #define BLTIN(cmd, func, help) { cmd, func }
613 /* For now, echo and test are unconditionally enabled.
614 * Maybe make it configurable? */
615 static const struct built_in_command bltins[] = {
616 BLTIN("." , builtin_source , "Run commands in a file"),
617 BLTIN(":" , builtin_true , "No-op"),
618 BLTIN("[" , builtin_test , "Test condition"),
620 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
622 #if ENABLE_HUSH_LOOPS
623 BLTIN("break" , builtin_break , "Exit from a loop"),
625 BLTIN("cd" , builtin_cd , "Change directory"),
626 #if ENABLE_HUSH_LOOPS
627 BLTIN("continue", builtin_continue, "Start new loop iteration"),
629 BLTIN("echo" , builtin_echo , "Write to stdout"),
630 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
631 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
632 BLTIN("exit" , builtin_exit , "Exit"),
633 BLTIN("export" , builtin_export , "Set environment variable"),
635 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
638 BLTIN("help" , builtin_help , "List shell built-in commands"),
641 BLTIN("jobs" , builtin_jobs , "List active jobs"),
644 BLTIN("memleak" , builtin_memleak , "Debug tool"),
646 BLTIN("pwd" , builtin_pwd , "Print current directory"),
647 BLTIN("read" , builtin_read , "Input environment variable"),
648 // BLTIN("return" , builtin_return , "Return from a function"),
649 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
650 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
651 BLTIN("test" , builtin_test , "Test condition"),
652 BLTIN("trap" , builtin_trap , "Trap signals"),
653 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
654 BLTIN("umask" , builtin_umask , "Set file creation mask"),
655 BLTIN("unset" , builtin_unset , "Unset environment variable"),
656 BLTIN("wait" , builtin_wait , "Wait for process"),
660 static void maybe_die(const char *notice, const char *msg)
662 /* Was using fancy stuff:
663 * (G_interactive_fd ? bb_error_msg : bb_error_msg_and_die)(...params...)
664 * but it SEGVs. ?! Oh well... explicit temp ptr works around that */
665 void FAST_FUNC (*fp)(const char *s, ...) = bb_error_msg_and_die;
666 #if ENABLE_HUSH_INTERACTIVE
667 if (G_interactive_fd)
670 fp(msg ? "%s: %s" : notice, notice, msg);
673 #define syntax(msg) maybe_die("syntax error", msg);
675 /* Debug -- trick gcc to expand __LINE__ and convert to string */
676 #define __syntax(msg, line) maybe_die("syntax error hush.c:" # line, msg)
677 #define _syntax(msg, line) __syntax(msg, line)
678 #define syntax(msg) _syntax(msg, __LINE__)
682 static int glob_needed(const char *s)
687 if (*s == '*' || *s == '[' || *s == '?')
694 static int is_assignment(const char *s)
696 if (!s || !(isalpha(*s) || *s == '_'))
699 while (isalnum(*s) || *s == '_')
704 /* Replace each \x with x in place, return ptr past NUL. */
705 static char *unbackslash(char *src)
711 if ((*dst++ = *src++) == '\0')
717 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
738 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
739 v[count1 + count2] = NULL;
742 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
745 #ifdef FOR_HUSH_LEAKTOOL
746 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
748 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
749 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
752 #define add_strings_to_strings(strings, add, need_to_dup) \
753 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
756 static char **add_string_to_strings(char **strings, char *add)
761 return add_strings_to_strings(strings, v, /*dup:*/ 0);
763 #ifdef FOR_HUSH_LEAKTOOL
764 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
766 char **ptr = add_string_to_strings(strings, add);
767 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
770 #define add_string_to_strings(strings, add) \
771 xx_add_string_to_strings(__LINE__, strings, add)
774 static void putenv_all(char **strings)
779 debug_printf_env("putenv '%s'\n", *strings);
784 static char **putenv_all_and_save_old(char **strings)
794 eq = strchr(*strings, '=');
797 v = getenv(*strings);
800 /* v points to VAL in VAR=VAL, go back to VAR */
801 v -= (eq - *strings) + 1;
802 old = add_string_to_strings(old, v);
811 static void free_strings_and_unsetenv(char **strings, int unset)
821 debug_printf_env("unsetenv '%s'\n", *v);
829 static void free_strings(char **strings)
831 free_strings_and_unsetenv(strings, 0);
835 /* Basic theory of signal handling in shell
836 * ========================================
837 * This does not describe what hush does, rather, it is current understanding
838 * what it _should_ do. If it doesn't, it's a bug.
839 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
841 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
842 * is finished or backgrounded. It is the same in interactive and
843 * non-interactive shells, and is the same regardless of whether
844 * a user trap handler is installed or a shell special one is in effect.
845 * ^C or ^Z from keyboard seem to execute "at once" because it usually
846 * backgrounds (i.e. stops) or kills all members of currently running
849 * Wait builtin in interruptible by signals for which user trap is set
850 * or by SIGINT in interactive shell.
852 * Trap handlers will execute even within trap handlers. (right?)
854 * User trap handlers are forgotten when subshell ("(cmd)") is entered. [TODO]
856 * If job control is off, backgrounded commands ("cmd &")
857 * have SIGINT, SIGQUIT set to SIG_IGN.
859 * Commands run in command substitution ("`cmd`")
860 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
862 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
863 * by the shell from its parent.
865 * Siganls which differ from SIG_DFL action
866 * (note: child (i.e., [v]forked) shell is not an interactive shell):
869 * SIGTERM (interactive): ignore
870 * SIGHUP (interactive):
871 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
872 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
873 * (note that ^Z is handled not by trapping SIGTSTP, but by seeing
874 * that all pipe members are stopped) (right?)
875 * SIGINT (interactive): wait for last pipe, ignore the rest
876 * of the command line, show prompt. NB: ^C does not send SIGINT
877 * to interactive shell while shell is waiting for a pipe,
878 * since shell is bg'ed (is not in foreground process group).
879 * (check/expand this)
880 * Example 1: this waits 5 sec, but does not execute ls:
881 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
882 * Example 2: this does not wait and does not execute ls:
883 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
884 * Example 3: this does not wait 5 sec, but executes ls:
885 * "sleep 5; ls -l" + press ^C
887 * (What happens to signals which are IGN on shell start?)
888 * (What happens with signal mask on shell start?)
890 * Implementation in hush
891 * ======================
892 * We use in-kernel pending signal mask to determine which signals were sent.
893 * We block all signals which we don't want to take action immediately,
894 * i.e. we block all signals which need to have special handling as described
895 * above, and all signals which have traps set.
896 * After each pipe execution, we extract any pending signals via sigtimedwait()
899 * unsigned non_DFL_mask: a mask of such "special" signals
900 * sigset_t blocked_set: current blocked signal set
903 * clear bit in blocked_set unless it is also in non_DFL_mask
904 * "trap 'cmd' SIGxxx":
905 * set bit in blocked_set (even if 'cmd' is '')
906 * after [v]fork, if we plan to be a shell:
907 * nothing for {} child shell (say, "true | { true; true; } | true")
908 * unset all traps if () shell. [TODO]
909 * after [v]fork, if we plan to exec:
910 * POSIX says pending signal mask is cleared in child - no need to clear it.
911 * Restore blocked signal set to one inherited by shell just prior to exec.
913 * Note: as a result, we do not use signal handlers much. The only uses
914 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
915 * and to restore tty pgrp on signal-induced exit.
918 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
920 // G.count_SIGCHLD++;
923 static int check_and_run_traps(int sig)
925 static const struct timespec zero_timespec = { 0, 0 };
926 smalluint save_rcode;
932 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
937 if (G.traps && G.traps[sig]) {
938 if (G.traps[sig][0]) {
939 /* We have user-defined handler */
940 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
941 save_rcode = G.last_exitcode;
944 G.last_exitcode = save_rcode;
945 } /* else: "" trap, ignoring signal */
948 /* not a trap: special action */
951 // G.count_SIGCHLD++;
960 default: /* ignored: */
961 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
970 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
971 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
972 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
973 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
975 /* Restores tty foreground process group, and exits.
976 * May be called as signal handler for fatal signal
977 * (will faithfully resend signal to itself, producing correct exit state)
978 * or called directly with -EXITCODE.
979 * We also call it if xfunc is exiting. */
980 static void sigexit(int sig) NORETURN;
981 static void sigexit(int sig)
983 /* Disable all signals: job control, SIGPIPE, etc. */
984 sigprocmask_allsigs(SIG_BLOCK);
986 /* Careful: we can end up here after [v]fork. Do not restore
987 * tty pgrp then, only top-level shell process does that */
988 if (G_interactive_fd && getpid() == G.root_pid)
989 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
991 /* Not a signal, just exit */
995 kill_myself_with_sig(sig); /* does not return */
999 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1000 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1004 /* Restores tty foreground process group, and exits. */
1005 static void hush_exit(int exitcode) NORETURN;
1006 static void hush_exit(int exitcode)
1008 if (G.traps && G.traps[0] && G.traps[0][0]) {
1009 char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
1010 //TODO: do we need to prevent recursion?
1016 fflush(NULL); /* flush all streams */
1017 sigexit(- (exitcode & 0xff));
1024 static const char *set_cwd(void)
1026 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1027 * we must not try to free(bb_msg_unknown) */
1028 if (G.cwd == bb_msg_unknown)
1030 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1032 G.cwd = bb_msg_unknown;
1037 /* Get/check local shell variables */
1038 static struct variable *get_local_var(const char *name)
1040 struct variable *cur;
1046 for (cur = G.top_var; cur; cur = cur->next) {
1047 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1053 static const char *get_local_var_value(const char *src)
1055 struct variable *var = get_local_var(src);
1057 return strchr(var->varstr, '=') + 1;
1061 /* str holds "NAME=VAL" and is expected to be malloced.
1062 * We take ownership of it.
1066 * -1: if NAME is set, leave export status alone
1067 * if NAME is not set, do not export
1068 * flg_read_only is set only when we handle -R var=val
1071 #define set_local_var(str, flg_export, flg_read_only) \
1072 set_local_var(str, flg_export)
1074 static int set_local_var(char *str, int flg_export, int flg_read_only)
1076 struct variable *cur;
1080 value = strchr(str, '=');
1081 if (!value) { /* not expected to ever happen? */
1086 name_len = value - str + 1; /* including '=' */
1087 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1089 if (strncmp(cur->varstr, str, name_len) != 0) {
1091 /* Bail out. Note that now cur points
1092 * to last var in linked list */
1098 /* We found an existing var with this name */
1100 if (cur->flg_read_only) {
1104 bb_error_msg("%s: readonly variable", str);
1108 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1109 unsetenv(str); /* just in case */
1111 if (strcmp(cur->varstr, str) == 0) {
1116 if (cur->max_len >= strlen(str)) {
1117 /* This one is from startup env, reuse space */
1118 strcpy(cur->varstr, str);
1121 /* max_len == 0 signifies "malloced" var, which we can
1122 * (and has to) free */
1126 goto set_str_and_exp;
1129 /* Not found - create next variable struct */
1130 cur->next = xzalloc(sizeof(*cur));
1136 cur->flg_read_only = flg_read_only;
1139 if (flg_export == 1)
1140 cur->flg_export = 1;
1141 if (cur->flg_export) {
1142 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1143 return putenv(cur->varstr);
1148 static int unset_local_var(const char *name)
1150 struct variable *cur;
1151 struct variable *prev = prev; /* for gcc */
1155 return EXIT_SUCCESS;
1156 name_len = strlen(name);
1159 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1160 if (cur->flg_read_only) {
1161 bb_error_msg("%s: readonly variable", name);
1162 return EXIT_FAILURE;
1164 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1165 * is ro, and we cannot reach this code on the 1st pass */
1166 prev->next = cur->next;
1167 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1168 bb_unsetenv(cur->varstr);
1172 return EXIT_SUCCESS;
1177 return EXIT_SUCCESS;
1180 #if ENABLE_SH_MATH_SUPPORT
1181 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1182 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1183 static char *endofname(const char *name)
1191 if (!is_in_name(*p))
1197 static void arith_set_local_var(const char *name, const char *val, int flags)
1199 /* arith code doesnt malloc space, so do it for it */
1200 char *var = xasprintf("%s=%s", name, val);
1201 set_local_var(var, flags, 0);
1209 static int static_get(struct in_str *i)
1218 static int static_peek(struct in_str *i)
1223 #if ENABLE_HUSH_INTERACTIVE
1225 static void cmdedit_set_initial_prompt(void)
1227 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1228 G.PS1 = getenv("PS1");
1235 static const char* setup_prompt_string(int promptmode)
1237 const char *prompt_str;
1238 debug_printf("setup_prompt_string %d ", promptmode);
1239 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1240 /* Set up the prompt */
1241 if (promptmode == 0) { /* PS1 */
1243 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1248 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1249 debug_printf("result '%s'\n", prompt_str);
1253 static void get_user_input(struct in_str *i)
1256 const char *prompt_str;
1258 prompt_str = setup_prompt_string(i->promptmode);
1259 #if ENABLE_FEATURE_EDITING
1260 /* Enable command line editing only while a command line
1261 * is actually being read */
1264 /* buglet: SIGINT will not make new prompt to appear _at once_,
1265 * only after <Enter>. (^C will work) */
1266 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1267 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1268 check_and_run_traps(0);
1269 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1270 i->eof_flag = (r < 0);
1271 if (i->eof_flag) { /* EOF/error detected */
1272 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1273 G.user_input_buf[1] = '\0';
1278 fputs(prompt_str, stdout);
1280 G.user_input_buf[0] = r = fgetc(i->file);
1281 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1282 //do we need check_and_run_traps(0)? (maybe only if stdin)
1283 } while (G.flag_SIGINT);
1284 i->eof_flag = (r == EOF);
1286 i->p = G.user_input_buf;
1289 #endif /* INTERACTIVE */
1291 /* This is the magic location that prints prompts
1292 * and gets data back from the user */
1293 static int file_get(struct in_str *i)
1297 /* If there is data waiting, eat it up */
1298 if (i->p && *i->p) {
1299 #if ENABLE_HUSH_INTERACTIVE
1303 if (i->eof_flag && !*i->p)
1305 /* note: ch is never NUL */
1307 /* need to double check i->file because we might be doing something
1308 * more complicated by now, like sourcing or substituting. */
1309 #if ENABLE_HUSH_INTERACTIVE
1310 if (G_interactive_fd && i->promptme && i->file == stdin) {
1313 } while (!*i->p); /* need non-empty line */
1314 i->promptmode = 1; /* PS2 */
1319 do ch = fgetc(i->file); while (ch == '\0');
1321 debug_printf("file_get: got '%c' %d\n", ch, ch);
1322 #if ENABLE_HUSH_INTERACTIVE
1329 /* All callers guarantee this routine will never
1330 * be used right after a newline, so prompting is not needed.
1332 static int file_peek(struct in_str *i)
1335 if (i->p && *i->p) {
1336 if (i->eof_flag && !i->p[1])
1339 /* note: ch is never NUL */
1341 do ch = fgetc(i->file); while (ch == '\0');
1342 i->eof_flag = (ch == EOF);
1343 i->peek_buf[0] = ch;
1344 i->peek_buf[1] = '\0';
1346 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1350 static void setup_file_in_str(struct in_str *i, FILE *f)
1352 i->peek = file_peek;
1354 #if ENABLE_HUSH_INTERACTIVE
1356 i->promptmode = 0; /* PS1 */
1362 static void setup_string_in_str(struct in_str *i, const char *s)
1364 i->peek = static_peek;
1365 i->get = static_get;
1366 #if ENABLE_HUSH_INTERACTIVE
1368 i->promptmode = 0; /* PS1 */
1378 #define B_CHUNK (32 * sizeof(char*))
1380 static void o_reset(o_string *o)
1388 static void o_free(o_string *o)
1391 memset(o, 0, sizeof(*o));
1394 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1399 static void o_grow_by(o_string *o, int len)
1401 if (o->length + len > o->maxlen) {
1402 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1403 o->data = xrealloc(o->data, 1 + o->maxlen);
1407 static void o_addchr(o_string *o, int ch)
1409 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1411 o->data[o->length] = ch;
1413 o->data[o->length] = '\0';
1416 static void o_addblock(o_string *o, const char *str, int len)
1419 memcpy(&o->data[o->length], str, len);
1421 o->data[o->length] = '\0';
1425 static void o_addstr(o_string *o, const char *str)
1427 o_addblock(o, str, strlen(str));
1429 static void nommu_addchr(o_string *o, int ch)
1435 #define nommu_addchr(o, str) ((void)0)
1438 static void o_addstr_with_NUL(o_string *o, const char *str)
1440 o_addblock(o, str, strlen(str) + 1);
1443 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1448 && (*str != '*' && *str != '?' && *str != '[')
1456 /* My analysis of quoting semantics tells me that state information
1457 * is associated with a destination, not a source.
1459 static void o_addqchr(o_string *o, int ch)
1462 char *found = strchr("*?[\\", ch);
1467 o->data[o->length] = '\\';
1470 o->data[o->length] = ch;
1472 o->data[o->length] = '\0';
1475 static void o_addQchr(o_string *o, int ch)
1478 if (o->o_escape && strchr("*?[\\", ch)) {
1480 o->data[o->length] = '\\';
1484 o->data[o->length] = ch;
1486 o->data[o->length] = '\0';
1489 static void o_addQstr(o_string *o, const char *str, int len)
1492 o_addblock(o, str, len);
1498 int ordinary_cnt = strcspn(str, "*?[\\");
1499 if (ordinary_cnt > len) /* paranoia */
1501 o_addblock(o, str, ordinary_cnt);
1502 if (ordinary_cnt == len)
1504 str += ordinary_cnt;
1505 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1509 if (ch) { /* it is necessarily one of "*?[\\" */
1511 o->data[o->length] = '\\';
1515 o->data[o->length] = ch;
1517 o->data[o->length] = '\0';
1521 /* A special kind of o_string for $VAR and `cmd` expansion.
1522 * It contains char* list[] at the beginning, which is grown in 16 element
1523 * increments. Actual string data starts at the next multiple of 16 * (char*).
1524 * list[i] contains an INDEX (int!) into this string data.
1525 * It means that if list[] needs to grow, data needs to be moved higher up
1526 * but list[i]'s need not be modified.
1527 * NB: remembering how many list[i]'s you have there is crucial.
1528 * o_finalize_list() operation post-processes this structure - calculates
1529 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1531 #if DEBUG_EXPAND || DEBUG_GLOB
1532 static void debug_print_list(const char *prefix, o_string *o, int n)
1534 char **list = (char**)o->data;
1535 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1537 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1538 prefix, list, n, string_start, o->length, o->maxlen);
1540 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1541 o->data + (int)list[i] + string_start,
1542 o->data + (int)list[i] + string_start);
1546 const char *p = o->data + (int)list[n - 1] + string_start;
1547 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1551 #define debug_print_list(prefix, o, n) ((void)0)
1554 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1555 * in list[n] so that it points past last stored byte so far.
1556 * It returns n+1. */
1557 static int o_save_ptr_helper(o_string *o, int n)
1559 char **list = (char**)o->data;
1563 if (!o->has_empty_slot) {
1564 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1565 string_len = o->length - string_start;
1566 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1567 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1568 /* list[n] points to string_start, make space for 16 more pointers */
1569 o->maxlen += 0x10 * sizeof(list[0]);
1570 o->data = xrealloc(o->data, o->maxlen + 1);
1571 list = (char**)o->data;
1572 memmove(list + n + 0x10, list + n, string_len);
1573 o->length += 0x10 * sizeof(list[0]);
1575 debug_printf_list("list[%d]=%d string_start=%d\n",
1576 n, string_len, string_start);
1579 /* We have empty slot at list[n], reuse without growth */
1580 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1581 string_len = o->length - string_start;
1582 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1583 n, string_len, string_start);
1584 o->has_empty_slot = 0;
1586 list[n] = (char*)(ptrdiff_t)string_len;
1590 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1591 static int o_get_last_ptr(o_string *o, int n)
1593 char **list = (char**)o->data;
1594 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1596 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1599 /* o_glob performs globbing on last list[], saving each result
1600 * as a new list[]. */
1601 static int o_glob(o_string *o, int n)
1607 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1609 return o_save_ptr_helper(o, n);
1610 pattern = o->data + o_get_last_ptr(o, n);
1611 debug_printf_glob("glob pattern '%s'\n", pattern);
1612 if (!glob_needed(pattern)) {
1614 o->length = unbackslash(pattern) - o->data;
1615 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1616 return o_save_ptr_helper(o, n);
1619 memset(&globdata, 0, sizeof(globdata));
1620 gr = glob(pattern, 0, NULL, &globdata);
1621 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1622 if (gr == GLOB_NOSPACE)
1623 bb_error_msg_and_die("out of memory during glob");
1624 if (gr == GLOB_NOMATCH) {
1625 globfree(&globdata);
1628 if (gr != 0) { /* GLOB_ABORTED ? */
1629 //TODO: testcase for bad glob pattern behavior
1630 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1632 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1633 char **argv = globdata.gl_pathv;
1634 o->length = pattern - o->data; /* "forget" pattern */
1636 o_addstr_with_NUL(o, *argv);
1637 n = o_save_ptr_helper(o, n);
1643 globfree(&globdata);
1645 debug_print_list("o_glob returning", o, n);
1649 /* If o->o_glob == 1, glob the string so far remembered.
1650 * Otherwise, just finish current list[] and start new */
1651 static int o_save_ptr(o_string *o, int n)
1653 if (o->o_glob) { /* if globbing is requested */
1654 /* If o->has_empty_slot, list[n] was already globbed
1655 * (if it was requested back then when it was filled)
1656 * so don't do that again! */
1657 if (!o->has_empty_slot)
1658 return o_glob(o, n); /* o_save_ptr_helper is inside */
1660 return o_save_ptr_helper(o, n);
1663 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1664 static char **o_finalize_list(o_string *o, int n)
1669 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1671 debug_print_list("finalized", o, n);
1672 debug_printf_expand("finalized n:%d\n", n);
1673 list = (char**)o->data;
1674 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1678 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1684 /* Expansion can recurse */
1685 #if ENABLE_HUSH_TICK
1686 static int process_command_subs(o_string *dest, const char *s);
1688 static char *expand_string_to_string(const char *str);
1690 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1691 parse_stream_dquoted(dest, input, dquote_end)
1693 static int parse_stream_dquoted(o_string *as_string,
1695 struct in_str *input,
1698 /* expand_strvec_to_strvec() takes a list of strings, expands
1699 * all variable references within and returns a pointer to
1700 * a list of expanded strings, possibly with larger number
1701 * of strings. (Think VAR="a b"; echo $VAR).
1702 * This new list is allocated as a single malloc block.
1703 * NULL-terminated list of char* pointers is at the beginning of it,
1704 * followed by strings themself.
1705 * Caller can deallocate entire list by single free(list). */
1707 /* Store given string, finalizing the word and starting new one whenever
1708 * we encounter IFS char(s). This is used for expanding variable values.
1709 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1710 static int expand_on_ifs(o_string *output, int n, const char *str)
1713 int word_len = strcspn(str, G.ifs);
1715 if (output->o_escape || !output->o_glob)
1716 o_addQstr(output, str, word_len);
1717 else /* protect backslashes against globbing up :) */
1718 o_addblock_duplicate_backslash(output, str, word_len);
1721 if (!*str) /* EOL - do not finalize word */
1723 o_addchr(output, '\0');
1724 debug_print_list("expand_on_ifs", output, n);
1725 n = o_save_ptr(output, n);
1726 str += strspn(str, G.ifs); /* skip ifs chars */
1728 debug_print_list("expand_on_ifs[1]", output, n);
1732 /* Helper to expand $((...)) and heredoc body. These act as if
1733 * they are in double quotes, with the exception that they are not :).
1734 * Just the rules are similar: "expand only $var and `cmd`"
1736 * Returns malloced string.
1737 * As an optimization, we return NULL if expansion is not needed.
1739 static char *expand_pseudo_dquoted(const char *str)
1742 struct in_str input;
1743 o_string dest = NULL_O_STRING;
1745 if (strchr(str, '$') == NULL
1746 #if ENABLE_HUSH_TICK
1747 && strchr(str, '`') == NULL
1753 /* We need to expand. Example:
1754 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1756 setup_string_in_str(&input, str);
1757 parse_stream_dquoted(NULL, &dest, &input, EOF);
1758 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1759 exp_str = expand_string_to_string(dest.data);
1760 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1761 o_free_unsafe(&dest);
1765 /* Expand all variable references in given string, adding words to list[]
1766 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1767 * to be filled). This routine is extremely tricky: has to deal with
1768 * variables/parameters with whitespace, $* and $@, and constructs like
1769 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1770 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1772 /* or_mask is either 0 (normal case) or 0x80
1773 * (expansion of right-hand side of assignment == 1-element expand.
1774 * It will also do no globbing, and thus we must not backslash-quote!) */
1776 char first_ch, ored_ch;
1784 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1785 debug_print_list("expand_vars_to_list", output, n);
1786 n = o_save_ptr(output, n);
1787 debug_print_list("expand_vars_to_list[0]", output, n);
1789 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1790 #if ENABLE_HUSH_TICK
1791 o_string subst_result = NULL_O_STRING;
1793 #if ENABLE_SH_MATH_SUPPORT
1794 char arith_buf[sizeof(arith_t)*3 + 2];
1796 o_addblock(output, arg, p - arg);
1797 debug_print_list("expand_vars_to_list[1]", output, n);
1799 p = strchr(p, SPECIAL_VAR_SYMBOL);
1801 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1802 /* "$@" is special. Even if quoted, it can still
1803 * expand to nothing (not even an empty string) */
1804 if ((first_ch & 0x7f) != '@')
1805 ored_ch |= first_ch;
1808 switch (first_ch & 0x7f) {
1809 /* Highest bit in first_ch indicates that var is double-quoted */
1811 val = utoa(G.root_pid);
1813 case '!': /* bg pid */
1814 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
1816 case '?': /* exitcode */
1817 val = utoa(G.last_exitcode);
1819 case '#': /* argc */
1820 if (arg[1] != SPECIAL_VAR_SYMBOL)
1821 /* actually, it's a ${#var} */
1823 val = utoa(G.global_argc ? G.global_argc-1 : 0);
1828 if (!G.global_argv[i])
1830 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
1831 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
1832 smallint sv = output->o_escape;
1833 /* unquoted var's contents should be globbed, so don't escape */
1834 output->o_escape = 0;
1835 while (G.global_argv[i]) {
1836 n = expand_on_ifs(output, n, G.global_argv[i]);
1837 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
1838 if (G.global_argv[i++][0] && G.global_argv[i]) {
1839 /* this argv[] is not empty and not last:
1840 * put terminating NUL, start new word */
1841 o_addchr(output, '\0');
1842 debug_print_list("expand_vars_to_list[2]", output, n);
1843 n = o_save_ptr(output, n);
1844 debug_print_list("expand_vars_to_list[3]", output, n);
1847 output->o_escape = sv;
1849 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
1850 * and in this case should treat it like '$*' - see 'else...' below */
1851 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
1853 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1854 if (++i >= G.global_argc)
1856 o_addchr(output, '\0');
1857 debug_print_list("expand_vars_to_list[4]", output, n);
1858 n = o_save_ptr(output, n);
1860 } else { /* quoted $*: add as one word */
1862 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
1863 if (!G.global_argv[++i])
1866 o_addchr(output, G.ifs[0]);
1870 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
1871 /* "Empty variable", used to make "" etc to not disappear */
1875 #if ENABLE_HUSH_TICK
1876 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
1879 //TODO: can we just stuff it into "output" directly?
1880 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
1881 process_command_subs(&subst_result, arg);
1882 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
1883 val = subst_result.data;
1886 #if ENABLE_SH_MATH_SUPPORT
1887 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
1888 arith_eval_hooks_t hooks;
1893 arg++; /* skip '+' */
1894 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
1895 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
1897 exp_str = expand_pseudo_dquoted(arg);
1898 hooks.lookupvar = get_local_var_value;
1899 hooks.setvar = arith_set_local_var;
1900 hooks.endofname = endofname;
1901 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
1906 case -3: maybe_die("arith", "exponent less than 0"); break;
1907 case -2: maybe_die("arith", "divide by zero"); break;
1908 case -5: maybe_die("arith", "expression recursion loop detected"); break;
1909 default: maybe_die("arith", "syntax error"); break;
1912 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
1913 sprintf(arith_buf, arith_t_fmt, res);
1918 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
1920 bool exp_len = false;
1921 bool exp_null = false;
1923 char exp_save = exp_save; /* for compiler */
1924 char exp_op = exp_op; /* for compiler */
1925 char *exp_word = exp_word; /* for compiler */
1929 arg[0] = first_ch & 0x7f;
1931 /* prepare for expansions */
1932 if (var[0] == '#') {
1933 /* handle length expansion ${#var} */
1937 /* maybe handle parameter expansion */
1938 exp_off = strcspn(var, ":-=+?%#");
1942 exp_save = var[exp_off];
1943 exp_null = exp_save == ':';
1944 exp_word = var + exp_off;
1945 if (exp_null) ++exp_word;
1946 exp_op = *exp_word++;
1947 var[exp_off] = '\0';
1951 /* lookup the variable in question */
1952 if (isdigit(var[0])) {
1953 /* handle_dollar() should have vetted var for us */
1955 if (i < G.global_argc)
1956 val = G.global_argv[i];
1957 /* else val remains NULL: $N with too big N */
1959 val = get_local_var_value(var);
1961 /* handle any expansions */
1963 debug_printf_expand("expand: length of '%s' = ", val);
1964 val = utoa(val ? strlen(val) : 0);
1965 debug_printf_expand("%s\n", val);
1966 } else if (exp_off) {
1967 if (exp_op == '%' || exp_op == '#') {
1968 /* we need to do a pattern match */
1971 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
1972 if (exp_op == *exp_word) /* ## or %% */
1974 val = dyn_val = xstrdup(val);
1975 loc = scan(dyn_val, exp_word, zero);
1981 /* we need to do an expansion */
1982 int exp_test = (!val || (exp_null && !val[0]));
1984 exp_test = !exp_test;
1985 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
1986 exp_null ? "true" : "false", exp_test);
1989 maybe_die(var, *exp_word ? exp_word : "parameter null or not set");
1993 if (exp_op == '=') {
1994 if (isdigit(var[0]) || var[0] == '#') {
1995 maybe_die(var, "special vars cannot assign in this way");
1998 char *new_var = xmalloc(strlen(var) + strlen(val) + 2);
1999 sprintf(new_var, "%s=%s", var, val);
2000 set_local_var(new_var, -1, 0);
2006 var[exp_off] = exp_save;
2010 #if ENABLE_HUSH_TICK
2013 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2014 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2016 /* unquoted var's contents should be globbed, so don't escape */
2017 smallint sv = output->o_escape;
2018 output->o_escape = 0;
2019 n = expand_on_ifs(output, n, val);
2021 output->o_escape = sv;
2023 } else { /* quoted $VAR, val will be appended below */
2024 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2027 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2029 o_addQstr(output, val, strlen(val));
2033 /* Do the check to avoid writing to a const string */
2034 if (*p != SPECIAL_VAR_SYMBOL)
2035 *p = SPECIAL_VAR_SYMBOL;
2037 #if ENABLE_HUSH_TICK
2038 o_free(&subst_result);
2041 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2044 debug_print_list("expand_vars_to_list[a]", output, n);
2045 /* this part is literal, and it was already pre-quoted
2046 * if needed (much earlier), do not use o_addQstr here! */
2047 o_addstr_with_NUL(output, arg);
2048 debug_print_list("expand_vars_to_list[b]", output, n);
2049 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2050 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2053 /* allow to reuse list[n] later without re-growth */
2054 output->has_empty_slot = 1;
2056 o_addchr(output, '\0');
2061 static char **expand_variables(char **argv, int or_mask)
2066 o_string output = NULL_O_STRING;
2068 if (or_mask & 0x100) {
2069 output.o_escape = 1; /* protect against globbing for "$var" */
2070 /* (unquoted $var will temporarily switch it off) */
2077 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2080 debug_print_list("expand_variables", &output, n);
2082 /* output.data (malloced in one block) gets returned in "list" */
2083 list = o_finalize_list(&output, n);
2084 debug_print_strings("expand_variables[1]", list);
2088 static char **expand_strvec_to_strvec(char **argv)
2090 return expand_variables(argv, 0x100);
2093 /* Used for expansion of right hand of assignments */
2094 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2096 static char *expand_string_to_string(const char *str)
2098 char *argv[2], **list;
2100 argv[0] = (char*)str;
2102 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2104 if (!list[0] || list[1])
2105 bb_error_msg_and_die("BUG in varexp2");
2106 /* actually, just move string 2*sizeof(char*) bytes back */
2107 overlapping_strcpy((char*)list, list[0]);
2108 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2112 /* Used for "eval" builtin */
2113 static char* expand_strvec_to_string(char **argv)
2117 list = expand_variables(argv, 0x80);
2118 /* Convert all NULs to spaces */
2123 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2124 bb_error_msg_and_die("BUG in varexp3");
2125 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2129 overlapping_strcpy((char*)list, list[0]);
2130 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2134 static char **expand_assignments(char **argv, int count)
2138 /* Expand assignments into one string each */
2139 for (i = 0; i < count; i++) {
2140 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2147 void re_execute_shell(const char *s, int is_heredoc); /* never called */
2148 #define clean_up_after_re_execute() ((void)0)
2149 static void reset_traps_to_defaults(void)
2157 for (sig = 0; sig < NSIG; sig++) {
2161 G.traps[sig] = NULL;
2162 /* There is no signal for 0 (EXIT) */
2165 /* there was a trap handler, we are removing it
2166 * (if sig has non-DFL handling,
2167 * we don't need to do anything) */
2168 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
2170 sigdelset(&G.blocked_set, sig);
2174 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2179 static void re_execute_shell(const char *s, int is_heredoc) NORETURN;
2180 static void re_execute_shell(const char *s, int is_heredoc)
2182 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2183 char *heredoc_argv[4];
2184 struct variable *cur;
2185 char **argv, **pp, **pp2;
2189 argv = heredoc_argv;
2190 argv[0] = (char *) G.argv0_for_re_execing;
2191 argv[1] = (char *) "-<";
2192 argv[2] = (char *) s;
2194 pp = &argv[3]; /* used as pointer to empty environmaent */
2198 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2199 , (unsigned) G.root_pid
2200 , (unsigned) G.last_bg_pid
2201 , (unsigned) G.last_exitcode
2202 USE_HUSH_LOOPS(, G.depth_of_loop)
2204 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...>
2205 * 3:-c 4:<cmd> <argN...> 5:NULL
2207 cnt = 5 + G.global_argc;
2208 for (cur = G.top_var; cur; cur = cur->next) {
2209 if (!cur->flg_export || cur->flg_read_only)
2212 G.argv_from_re_execing = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2213 *pp++ = (char *) G.argv0_for_re_execing;
2215 for (cur = G.top_var; cur; cur = cur->next) {
2216 if (cur->varstr == hush_version_str)
2218 if (cur->flg_read_only) {
2219 *pp++ = (char *) "-R";
2220 *pp++ = cur->varstr;
2221 } else if (!cur->flg_export) {
2222 *pp++ = (char *) "-V";
2223 *pp++ = cur->varstr;
2226 //TODO: pass functions
2227 /* We can pass activated traps here. Say, -Tnn:trap_string
2229 * However, POSIX says that subshells reset signals with traps
2231 * I tested bash-3.2 and it not only does that with true subshells
2232 * of the form ( list ), but with any forked children shells.
2233 * I set trap "echo W" WINCH; and then tried:
2235 * { echo 1; sleep 20; echo 2; } &
2236 * while true; do echo 1; sleep 20; echo 2; break; done &
2237 * true | { echo 1; sleep 20; echo 2; } | cat
2239 * In all these cases sending SIGWINCH to the child shell
2240 * did not run the trap. If I add trap "echo V" WINCH;
2241 * _inside_ group (just before echo 1), it works.
2243 * I conclude it means we don't need to pass active traps here.
2244 * exec syscall below resets them to SIG_DFL for us.
2246 *pp++ = (char *) "-c";
2248 pp2 = G.global_argv;
2251 /* *pp = NULL; - is already there */
2255 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2256 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2257 execve(bb_busybox_exec_path, argv, pp);
2258 /* Fallback. Useful for init=/bin/hush usage etc */
2259 if (argv[0][0] == '/')
2260 execve(argv[0], argv, pp);
2261 xfunc_error_retval = 127;
2262 bb_error_msg_and_die("can't re-execute the shell");
2265 static void clean_up_after_re_execute(void)
2267 char **pp = G.argv_from_re_execing;
2269 /* Must match re_execute_shell's allocations (if any) */
2271 G.argv_from_re_execing = NULL;
2274 #endif /* !BB_MMU */
2277 static void setup_heredoc(struct redir_struct *redir)
2279 struct fd_pair pair;
2282 /* the _body_ of heredoc (misleading field name) */
2283 const char *heredoc = redir->rd_filename;
2287 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2288 expanded = expand_pseudo_dquoted(heredoc);
2292 len = strlen(heredoc);
2294 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2296 xmove_fd(pair.rd, redir->rd_fd);
2298 /* Try writing without forking. Newer kernels have
2299 * dynamically growing pipes. Must use non-blocking write! */
2302 written = write(pair.wr, heredoc, len);
2312 ndelay_off(pair.wr);
2314 /* Okay, pipe buffer was not big enough */
2315 /* Note: we must not create a stray child (bastard? :)
2316 * for the unsuspecting parent process. Child creates a grandchild
2317 * and exits before parent execs the process which consumes heredoc
2318 * (that exec happens after we return from this function) */
2321 bb_perror_msg_and_die("vfork");
2324 pid = BB_MMU ? fork() : vfork();
2326 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2330 close(redir->rd_fd); /* read side of the pipe */
2332 full_write(pair.wr, heredoc, len); /* may loop or block */
2335 /* Delegate blocking writes to another process */
2336 disable_restore_tty_pgrp_on_exit();
2337 xmove_fd(pair.wr, STDOUT_FILENO);
2338 re_execute_shell(heredoc, 1);
2342 enable_restore_tty_pgrp_on_exit();
2343 clean_up_after_re_execute();
2346 wait(NULL); /* wait till child has died */
2349 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2350 * and stderr if they are redirected. */
2351 static int setup_redirects(struct command *prog, int squirrel[])
2353 //TODO: no callers ever check return value - ?!
2355 struct redir_struct *redir;
2357 for (redir = prog->redirects; redir; redir = redir->next) {
2358 if (redir->rd_type == REDIRECT_HEREDOC2) {
2359 if (squirrel && redir->rd_fd < 3) {
2360 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2362 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2364 debug_printf_parse("set heredoc '%s'\n",
2365 redir->rd_filename);
2366 setup_heredoc(redir);
2370 if (redir->rd_dup == -1) {
2372 if (redir->rd_filename == NULL) {
2373 /* Something went wrong in the parse.
2374 * Pretend it didn't happen */
2377 mode = redir_table[redir->rd_type].mode;
2378 //TODO: check redir for names like '\\'
2379 p = expand_string_to_string(redir->rd_filename);
2380 openfd = open_or_warn(p, mode);
2383 /* this could get lost if stderr has been redirected, but
2384 * bash and ash both lose it as well (though zsh doesn't!) */
2385 //what the above comment tries to say?
2389 openfd = redir->rd_dup;
2392 if (openfd != redir->rd_fd) {
2393 if (squirrel && redir->rd_fd < 3) {
2394 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2396 if (openfd == REDIRFD_CLOSE) {
2397 /* "n>-" means "close me" */
2398 close(redir->rd_fd);
2400 xdup2(openfd, redir->rd_fd);
2401 if (redir->rd_dup == -1)
2409 static void restore_redirects(int squirrel[])
2412 for (i = 0; i < 3; i++) {
2415 /* We simply die on error */
2423 #define free_pipe_list(head, indent) free_pipe_list(head)
2424 #define free_pipe(pi, indent) free_pipe(pi)
2426 static void free_pipe_list(struct pipe *head, int indent);
2428 /* Return code is the exit status of the pipe */
2429 static void free_pipe(struct pipe *pi, int indent)
2432 struct command *command;
2433 struct redir_struct *r, *rnext;
2436 if (pi->stopped_cmds > 0) /* why? */
2438 debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
2439 for (i = 0; i < pi->num_cmds; i++) {
2440 command = &pi->cmds[i];
2441 debug_printf_clean("%s command %d:\n", indenter(indent), i);
2442 if (command->argv) {
2443 for (a = 0, p = command->argv; *p; a++, p++) {
2444 debug_printf_clean("%s argv[%d] = %s\n",
2445 indenter(indent), a, *p);
2447 free_strings(command->argv);
2448 command->argv = NULL;
2450 /* not "else if": on syntax error, we may have both! */
2451 if (command->group) {
2452 debug_printf_clean("%s begin group (grp_type:%d)\n",
2453 indenter(indent), command->grp_type);
2454 free_pipe_list(command->group, indent+3);
2455 debug_printf_clean("%s end group\n", indenter(indent));
2456 command->group = NULL;
2459 free(command->group_as_string);
2460 command->group_as_string = NULL;
2462 for (r = command->redirects; r; r = rnext) {
2463 debug_printf_clean("%s redirect %d%s", indenter(indent),
2464 r->fd, redir_table[r->rd_type].descrip);
2465 /* guard against the case >$FOO, where foo is unset or blank */
2466 if (r->rd_filename) {
2467 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2468 free(r->rd_filename);
2469 r->rd_filename = NULL;
2471 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2475 command->redirects = NULL;
2477 free(pi->cmds); /* children are an array, they get freed all at once */
2485 static void free_pipe_list(struct pipe *head, int indent)
2487 struct pipe *pi, *next;
2489 for (pi = head; pi; pi = next) {
2491 debug_printf_clean("%s pipe reserved word %d\n", indenter(indent), pi->res_word);
2493 free_pipe(pi, indent);
2494 debug_printf_clean("%s pipe followup code %d\n", indenter(indent), pi->followup);
2496 /*pi->next = NULL;*/
2503 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2504 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2505 #define pseudo_exec(nommu_save, command, argv_expanded) \
2506 pseudo_exec(command, argv_expanded)
2509 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2511 * XXX no exit() here. If you don't exec, use _exit instead.
2512 * The at_exit handlers apparently confuse the calling process,
2513 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2514 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2515 char **argv, int assignment_cnt,
2516 char **argv_expanded) NORETURN;
2517 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2518 char **argv, int assignment_cnt,
2519 char **argv_expanded)
2523 /* Case when we are here: ... | var=val | ... */
2524 if (!argv[assignment_cnt])
2525 _exit(EXIT_SUCCESS);
2527 new_env = expand_assignments(argv, assignment_cnt);
2529 putenv_all(new_env);
2530 free(new_env); /* optional */
2532 nommu_save->new_env = new_env;
2533 nommu_save->old_env = putenv_all_and_save_old(new_env);
2535 if (argv_expanded) {
2536 argv = argv_expanded;
2538 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2540 nommu_save->argv = argv;
2544 /* On NOMMU, we must never block!
2545 * Example: { sleep 99999 | read line } & echo Ok
2546 * read builtin will block on read syscall, leaving parent blocked
2547 * in vfork. Therefore we can't do this:
2550 /* Check if the command matches any of the builtins.
2551 * Depending on context, this might be redundant. But it's
2552 * easier to waste a few CPU cycles than it is to figure out
2553 * if this is one of those cases.
2557 const struct built_in_command *x;
2558 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2559 if (strcmp(argv[0], x->cmd) == 0) {
2560 debug_printf_exec("running builtin '%s'\n",
2562 rcode = x->function(argv);
2570 #if ENABLE_FEATURE_SH_STANDALONE
2571 /* Check if the command matches any busybox applets */
2572 if (strchr(argv[0], '/') == NULL) {
2573 int a = find_applet_by_name(argv[0]);
2575 #if BB_MMU /* see above why on NOMMU it is not allowed */
2576 if (APPLET_IS_NOEXEC(a)) {
2577 debug_printf_exec("running applet '%s'\n", argv[0]);
2578 run_applet_no_and_exit(a, argv);
2581 /* Re-exec ourselves */
2582 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2583 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2584 execv(bb_busybox_exec_path, argv);
2585 /* If they called chroot or otherwise made the binary no longer
2586 * executable, fall through */
2591 debug_printf_exec("execing '%s'\n", argv[0]);
2592 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2593 execvp(argv[0], argv);
2594 bb_perror_msg("can't exec '%s'", argv[0]);
2595 _exit(EXIT_FAILURE);
2598 static int run_list(struct pipe *pi);
2600 /* Called after [v]fork() in run_pipe
2602 static void pseudo_exec(nommu_save_t *nommu_save,
2603 struct command *command,
2604 char **argv_expanded) NORETURN;
2605 static void pseudo_exec(nommu_save_t *nommu_save,
2606 struct command *command,
2607 char **argv_expanded)
2609 if (command->argv) {
2610 pseudo_exec_argv(nommu_save, command->argv,
2611 command->assignment_cnt, argv_expanded);
2614 if (command->group) {
2615 /* Cases when we are here:
2618 * ... | ( list ) | ...
2619 * ... | { list } | ...
2623 debug_printf_exec("pseudo_exec: run_list\n");
2624 reset_traps_to_defaults();
2625 rcode = run_list(command->group);
2626 /* OK to leak memory by not calling free_pipe_list,
2627 * since this process is about to exit */
2630 re_execute_shell(command->group_as_string, 0);
2634 /* Case when we are here: ... | >file */
2635 debug_printf_exec("pseudo_exec'ed null command\n");
2636 _exit(EXIT_SUCCESS);
2640 static const char *get_cmdtext(struct pipe *pi)
2646 /* This is subtle. ->cmdtext is created only on first backgrounding.
2647 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
2648 * On subsequent bg argv is trashed, but we won't use it */
2651 argv = pi->cmds[0].argv;
2652 if (!argv || !argv[0]) {
2653 pi->cmdtext = xzalloc(1);
2658 do len += strlen(*argv) + 1; while (*++argv);
2659 pi->cmdtext = p = xmalloc(len);
2660 argv = pi->cmds[0].argv;
2662 len = strlen(*argv);
2663 memcpy(p, *argv, len);
2671 static void insert_bg_job(struct pipe *pi)
2673 struct pipe *thejob;
2676 /* Linear search for the ID of the job to use */
2678 for (thejob = G.job_list; thejob; thejob = thejob->next)
2679 if (thejob->jobid >= pi->jobid)
2680 pi->jobid = thejob->jobid + 1;
2682 /* Add thejob to the list of running jobs */
2684 thejob = G.job_list = xmalloc(sizeof(*thejob));
2686 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
2688 thejob->next = xmalloc(sizeof(*thejob));
2689 thejob = thejob->next;
2692 /* Physically copy the struct job */
2693 memcpy(thejob, pi, sizeof(struct pipe));
2694 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
2695 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
2696 for (i = 0; i < pi->num_cmds; i++) {
2697 // TODO: do we really need to have so many fields which are just dead weight
2698 // at execution stage?
2699 thejob->cmds[i].pid = pi->cmds[i].pid;
2700 /* all other fields are not used and stay zero */
2702 thejob->next = NULL;
2703 thejob->cmdtext = xstrdup(get_cmdtext(pi));
2705 /* We don't wait for background thejobs to return -- append it
2706 to the list of backgrounded thejobs and leave it alone */
2707 if (G_interactive_fd)
2708 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
2709 G.last_bg_pid = thejob->cmds[0].pid;
2710 G.last_jobid = thejob->jobid;
2713 static void remove_bg_job(struct pipe *pi)
2715 struct pipe *prev_pipe;
2717 if (pi == G.job_list) {
2718 G.job_list = pi->next;
2720 prev_pipe = G.job_list;
2721 while (prev_pipe->next != pi)
2722 prev_pipe = prev_pipe->next;
2723 prev_pipe->next = pi->next;
2726 G.last_jobid = G.job_list->jobid;
2731 /* Remove a backgrounded job */
2732 static void delete_finished_bg_job(struct pipe *pi)
2735 pi->stopped_cmds = 0;
2741 /* Check to see if any processes have exited -- if they
2742 * have, figure out why and see if a job has completed */
2743 static int checkjobs(struct pipe* fg_pipe)
2753 debug_printf_jobs("checkjobs %p\n", fg_pipe);
2756 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
2757 // /* avoid doing syscall, nothing there anyway */
2760 attributes = WUNTRACED;
2761 if (fg_pipe == NULL)
2762 attributes |= WNOHANG;
2764 /* Do we do this right?
2765 * bash-3.00# sleep 20 | false
2767 * [3]+ Stopped sleep 20 | false
2768 * bash-3.00# echo $?
2769 * 1 <========== bg pipe is not fully done, but exitcode is already known!
2772 //FIXME: non-interactive bash does not continue even if all processes in fg pipe
2773 //are stopped. Testcase: "cat | cat" in a script (not on command line)
2774 // + killall -STOP cat
2781 // i = G.count_SIGCHLD;
2782 childpid = waitpid(-1, &status, attributes);
2783 if (childpid <= 0) {
2784 if (childpid && errno != ECHILD)
2785 bb_perror_msg("waitpid");
2786 // else /* Until next SIGCHLD, waitpid's are useless */
2787 // G.handled_SIGCHLD = i;
2790 dead = WIFEXITED(status) || WIFSIGNALED(status);
2793 if (WIFSTOPPED(status))
2794 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
2795 childpid, WSTOPSIG(status), WEXITSTATUS(status));
2796 if (WIFSIGNALED(status))
2797 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
2798 childpid, WTERMSIG(status), WEXITSTATUS(status));
2799 if (WIFEXITED(status))
2800 debug_printf_jobs("pid %d exited, exitcode %d\n",
2801 childpid, WEXITSTATUS(status));
2803 /* Were we asked to wait for fg pipe? */
2805 for (i = 0; i < fg_pipe->num_cmds; i++) {
2806 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
2807 if (fg_pipe->cmds[i].pid != childpid)
2809 /* printf("process %d exit %d\n", i, WEXITSTATUS(status)); */
2811 fg_pipe->cmds[i].pid = 0;
2812 fg_pipe->alive_cmds--;
2813 if (i == fg_pipe->num_cmds - 1) {
2814 /* last process gives overall exitstatus */
2815 rcode = WEXITSTATUS(status);
2816 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
2819 fg_pipe->cmds[i].is_stopped = 1;
2820 fg_pipe->stopped_cmds++;
2822 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
2823 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
2824 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
2825 /* All processes in fg pipe have exited/stopped */
2827 if (fg_pipe->alive_cmds)
2828 insert_bg_job(fg_pipe);
2832 /* There are still running processes in the fg pipe */
2833 goto wait_more; /* do waitpid again */
2835 /* it wasnt fg_pipe, look for process in bg pipes */
2839 /* We asked to wait for bg or orphaned children */
2840 /* No need to remember exitcode in this case */
2841 for (pi = G.job_list; pi; pi = pi->next) {
2842 for (i = 0; i < pi->num_cmds; i++) {
2843 if (pi->cmds[i].pid == childpid)
2844 goto found_pi_and_prognum;
2847 /* Happens when shell is used as init process (init=/bin/sh) */
2848 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
2849 continue; /* do waitpid again */
2851 found_pi_and_prognum:
2854 pi->cmds[i].pid = 0;
2856 if (!pi->alive_cmds) {
2857 if (G_interactive_fd)
2858 printf(JOB_STATUS_FORMAT, pi->jobid,
2859 "Done", pi->cmdtext);
2860 delete_finished_bg_job(pi);
2864 pi->cmds[i].is_stopped = 1;
2868 } /* while (waitpid succeeds)... */
2874 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
2877 int rcode = checkjobs(fg_pipe);
2878 /* Job finished, move the shell to the foreground */
2879 p = getpgid(0); /* pgid of our process */
2880 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
2881 tcsetpgrp(G_interactive_fd, p);
2886 /* Start all the jobs, but don't wait for anything to finish.
2889 * Return code is normally -1, when the caller has to wait for children
2890 * to finish to determine the exit status of the pipe. If the pipe
2891 * is a simple builtin command, however, the action is done by the
2892 * time run_pipe returns, and the exit code is provided as the
2895 * Returns -1 only if started some children. IOW: we have to
2896 * mask out retvals of builtins etc with 0xff!
2898 * The only case when we do not need to [v]fork is when the pipe
2899 * is single, non-backgrounded, non-subshell command. Examples:
2900 * cmd ; ... { list } ; ...
2901 * cmd && ... { list } && ...
2902 * cmd || ... { list } || ...
2903 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
2904 * or (if SH_STANDALONE) an applet, and we can run the { list }
2905 * with run_list(). If it isn't one of these, we fork and exec cmd.
2907 * Cases when we must fork:
2908 * non-single: cmd | cmd
2909 * backgrounded: cmd & { list } &
2910 * subshell: ( list ) [&]
2912 static int run_pipe(struct pipe *pi)
2914 static const char *const null_ptr = NULL;
2917 int pipefds[2]; /* pipefds[0] is for reading */
2918 struct command *command;
2919 char **argv_expanded;
2922 /* it is not always needed, but we aim to smaller code */
2923 int squirrel[] = { -1, -1, -1 };
2926 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
2928 USE_HUSH_JOB(pi->pgrp = -1;)
2929 pi->stopped_cmds = 0;
2930 command = &(pi->cmds[0]);
2931 argv_expanded = NULL;
2933 if (pi->num_cmds != 1
2934 || pi->followup == PIPE_BG
2935 || command->grp_type == GRP_SUBSHELL
2942 debug_printf_exec(": group:%p argv:'%s'\n",
2943 command->group, command->argv ? command->argv[0] : "NONE");
2945 if (command->group) {
2946 #if ENABLE_HUSH_FUNCTIONS
2947 if (command->grp_type == GRP_FUNCTION) {
2948 /* func () { list } */
2949 bb_error_msg("here we ought to remember function definition, and go on");
2950 return EXIT_SUCCESS;
2954 debug_printf("non-subshell group\n");
2955 setup_redirects(command, squirrel);
2956 debug_printf_exec(": run_list\n");
2957 rcode = run_list(command->group) & 0xff;
2958 restore_redirects(squirrel);
2959 debug_printf_exec("run_pipe return %d\n", rcode);
2960 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
2964 argv = command->argv ? command->argv : (char **) &null_ptr;
2966 const struct built_in_command *x;
2967 char **new_env = NULL;
2968 char **old_env = NULL;
2970 if (argv[command->assignment_cnt] == NULL) {
2971 /* Assignments, but no command */
2972 /* Ensure redirects take effect. Try "a=t >file" */
2973 setup_redirects(command, squirrel);
2974 restore_redirects(squirrel);
2975 /* Set shell variables */
2977 p = expand_string_to_string(*argv);
2978 debug_printf_exec("set shell var:'%s'->'%s'\n",
2980 set_local_var(p, 0, 0);
2983 /* Do we need to flag set_local_var() errors?
2984 * "assignment to readonly var" and "putenv error"
2986 return EXIT_SUCCESS;
2989 /* Expand the rest into (possibly) many strings each */
2990 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
2992 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2993 if (strcmp(argv_expanded[0], x->cmd) != 0)
2995 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
2996 debug_printf("exec with redirects only\n");
2997 setup_redirects(command, NULL);
2998 rcode = EXIT_SUCCESS;
2999 goto clean_up_and_ret1;
3001 debug_printf("builtin inline %s\n", argv_expanded[0]);
3002 /* XXX setup_redirects acts on file descriptors, not FILEs.
3003 * This is perfect for work that comes after exec().
3004 * Is it really safe for inline use? Experimentally,
3005 * things seem to work with glibc. */
3006 setup_redirects(command, squirrel);
3007 new_env = expand_assignments(argv, command->assignment_cnt);
3008 old_env = putenv_all_and_save_old(new_env);
3009 debug_printf_exec(": builtin '%s' '%s'...\n",
3010 x->cmd, argv_expanded[1]);
3011 rcode = x->function(argv_expanded) & 0xff;
3012 #if ENABLE_FEATURE_SH_STANDALONE
3015 restore_redirects(squirrel);
3016 free_strings_and_unsetenv(new_env, 1);
3017 putenv_all(old_env);
3018 /* Free the pointers, but the strings themselves
3019 * are in environ now, don't use free_strings! */
3022 free(argv_expanded);
3023 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3024 debug_printf_exec("run_pipe return %d\n", rcode);
3027 #if ENABLE_FEATURE_SH_STANDALONE
3028 i = find_applet_by_name(argv_expanded[0]);
3029 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3030 setup_redirects(command, squirrel);
3031 save_nofork_data(&G.nofork_save);
3032 new_env = expand_assignments(argv, command->assignment_cnt);
3033 old_env = putenv_all_and_save_old(new_env);
3034 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3035 argv_expanded[0], argv_expanded[1]);
3036 rcode = run_nofork_applet_prime(&G.nofork_save, i, argv_expanded);
3037 goto clean_up_and_ret;
3040 /* It is neither builtin nor applet. We must fork. */
3044 /* NB: argv_expanded may already be created, and that
3045 * might include `cmd` runs! Do not rerun it! We *must*
3046 * use argv_expanded if it's non-NULL */
3048 /* Going to fork a child per each pipe member */
3052 for (i = 0; i < pi->num_cmds; i++) {
3054 volatile nommu_save_t nommu_save;
3055 nommu_save.new_env = NULL;
3056 nommu_save.old_env = NULL;
3057 nommu_save.argv = NULL;
3059 command = &(pi->cmds[i]);
3060 if (command->argv) {
3061 debug_printf_exec(": pipe member '%s' '%s'...\n",
3062 command->argv[0], command->argv[1]);
3064 debug_printf_exec(": pipe member with no argv\n");
3067 /* pipes are inserted between pairs of commands */
3070 if ((i + 1) < pi->num_cmds)
3073 command->pid = BB_MMU ? fork() : vfork();
3074 if (!command->pid) { /* child */
3076 disable_restore_tty_pgrp_on_exit();
3078 /* Every child adds itself to new process group
3079 * with pgid == pid_of_first_child_in_pipe */
3080 if (G.run_list_level == 1 && G_interactive_fd) {
3083 if (pgrp < 0) /* true for 1st process only */
3085 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3086 /* We do it in *every* child, not just first,
3088 tcsetpgrp(G_interactive_fd, pgrp);
3092 xmove_fd(nextin, 0);
3093 xmove_fd(pipefds[1], 1); /* write end */
3095 close(pipefds[0]); /* read end */
3096 /* Like bash, explicit redirects override pipes,
3097 * and the pipe fd is available for dup'ing. */
3098 setup_redirects(command, NULL);
3100 /* Restore default handlers just prior to exec */
3101 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3103 /* Stores to nommu_save list of env vars putenv'ed
3104 * (NOMMU, on MMU we don't need that) */
3105 /* cast away volatility... */
3106 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3107 /* pseudo_exec() does not return */
3110 /* parent or error */
3111 enable_restore_tty_pgrp_on_exit();
3113 /* Clean up after vforked child */
3114 clean_up_after_re_execute();
3115 free(nommu_save.argv);
3116 free_strings_and_unsetenv(nommu_save.new_env, 1);
3117 putenv_all(nommu_save.old_env);
3118 /* Free the pointers, but the strings themselves
3119 * are in environ now, don't use free_strings! */
3120 free(nommu_save.old_env);
3122 free(argv_expanded);
3123 argv_expanded = NULL;
3124 if (command->pid < 0) { /* [v]fork failed */
3125 /* Clearly indicate, was it fork or vfork */
3126 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3130 /* Second and next children need to know pid of first one */
3132 pi->pgrp = command->pid;
3138 if ((i + 1) < pi->num_cmds)
3139 close(pipefds[1]); /* write end */
3140 /* Pass read (output) pipe end to next iteration */
3141 nextin = pipefds[0];
3144 if (!pi->alive_cmds) {
3145 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3149 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3153 #ifndef debug_print_tree
3154 static void debug_print_tree(struct pipe *pi, int lvl)
3156 static const char *const PIPE[] = {
3162 static const char *RES[] = {
3163 [RES_NONE ] = "NONE" ,
3166 [RES_THEN ] = "THEN" ,
3167 [RES_ELIF ] = "ELIF" ,
3168 [RES_ELSE ] = "ELSE" ,
3171 #if ENABLE_HUSH_LOOPS
3172 [RES_FOR ] = "FOR" ,
3173 [RES_WHILE] = "WHILE",
3174 [RES_UNTIL] = "UNTIL",
3176 [RES_DONE ] = "DONE" ,
3178 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3181 #if ENABLE_HUSH_CASE
3182 [RES_CASE ] = "CASE" ,
3183 [RES_MATCH] = "MATCH",
3184 [RES_CASEI] = "CASEI",
3185 [RES_ESAC ] = "ESAC" ,
3187 [RES_XXXX ] = "XXXX" ,
3188 [RES_SNTX ] = "SNTX" ,
3190 static const char *const GRPTYPE[] = {
3193 #if ENABLE_HUSH_FUNCTIONS
3202 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3203 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3205 while (prn < pi->num_cmds) {
3206 struct command *command = &pi->cmds[prn];
3207 char **argv = command->argv;
3209 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3211 command->assignment_cnt);
3212 if (command->group) {
3213 fprintf(stderr, " group %s: (argv=%p)\n",
3214 GRPTYPE[command->grp_type],
3216 debug_print_tree(command->group, lvl+1);
3220 if (argv) while (*argv) {
3221 fprintf(stderr, " '%s'", *argv);
3224 fprintf(stderr, "\n");
3233 /* NB: called by pseudo_exec, and therefore must not modify any
3234 * global data until exec/_exit (we can be a child after vfork!) */
3235 static int run_list(struct pipe *pi)
3237 #if ENABLE_HUSH_CASE
3238 char *case_word = NULL;
3240 #if ENABLE_HUSH_LOOPS
3241 struct pipe *loop_top = NULL;
3242 char *for_varname = NULL;
3243 char **for_lcur = NULL;
3244 char **for_list = NULL;
3246 smallint last_followup;
3248 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3249 smalluint cond_code = 0;
3251 enum { cond_code = 0 };
3254 smallint rword; /* enum reserved_style */
3255 smallint last_rword; /* ditto */
3258 debug_printf_exec("run_list start lvl %d\n", G.run_list_level + 1);
3260 #if ENABLE_HUSH_LOOPS
3261 /* Check syntax for "for" */
3262 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3263 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3265 /* current word is FOR or IN (BOLD in comments below) */
3266 if (cpipe->next == NULL) {
3267 syntax("malformed for");
3268 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3271 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3272 if (cpipe->next->res_word == RES_DO)
3274 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3275 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3276 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3278 syntax("malformed for");
3279 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3285 /* Past this point, all code paths should jump to ret: label
3286 * in order to return, no direct "return" statements please.
3287 * This helps to ensure that no memory is leaked. */
3289 ////TODO: ctrl-Z handling needs re-thinking and re-testing
3292 /* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
3293 * We are saving state before entering outermost list ("while...done")
3294 * so that ctrl-Z will correctly background _entire_ outermost list,
3295 * not just a part of it (like "sleep 1 | exit 2") */
3296 if (++G.run_list_level == 1 && G_interactive_fd) {
3297 if (sigsetjmp(G.toplevel_jb, 1)) {
3298 /* ctrl-Z forked and we are parent; or ctrl-C.
3299 * Sighandler has longjmped us here */
3300 signal(SIGINT, SIG_IGN);
3301 signal(SIGTSTP, SIG_IGN);
3302 /* Restore level (we can be coming from deep inside
3304 G.run_list_level = 1;
3305 #if ENABLE_FEATURE_SH_STANDALONE
3306 if (G.nofork_save.saved) { /* if save area is valid */
3307 debug_printf_jobs("exiting nofork early\n");
3308 restore_nofork_data(&G.nofork_save);
3311 //// if (G.ctrl_z_flag) {
3312 //// /* ctrl-Z has forked and stored pid of the child in pi->pid.
3313 //// * Remember this child as background job */
3314 //// insert_bg_job(pi);
3316 /* ctrl-C. We just stop doing whatever we were doing */
3319 USE_HUSH_LOOPS(loop_top = NULL;)
3320 USE_HUSH_LOOPS(G.depth_of_loop = 0;)
3324 //// /* ctrl-Z handler will store pid etc in pi */
3325 //// G.toplevel_list = pi;
3326 //// G.ctrl_z_flag = 0;
3327 ////#if ENABLE_FEATURE_SH_STANDALONE
3328 //// G.nofork_save.saved = 0; /* in case we will run a nofork later */
3330 //// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
3331 //// signal(SIGINT, handler_ctrl_c);
3337 last_rword = RES_XXXX;
3339 last_followup = PIPE_SEQ;
3340 rcode = G.last_exitcode;
3342 /* Go through list of pipes, (maybe) executing them. */
3343 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3347 IF_HAS_KEYWORDS(rword = pi->res_word;)
3348 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3349 rword, cond_code, last_rword);
3350 #if ENABLE_HUSH_LOOPS
3351 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3352 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3354 /* start of a loop: remember where loop starts */
3359 /* Still in the same "if...", "then..." or "do..." branch? */
3360 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3361 if ((rcode == 0 && last_followup == PIPE_OR)
3362 || (rcode != 0 && last_followup == PIPE_AND)
3364 /* It is "<true> || CMD" or "<false> && CMD"
3365 * and we should not execute CMD */
3366 debug_printf_exec("skipped cmd because of || or &&\n");
3367 last_followup = pi->followup;
3371 last_followup = pi->followup;
3372 IF_HAS_KEYWORDS(last_rword = rword;)
3375 if (rword == RES_THEN) {
3376 /* if false; then ... fi has exitcode 0! */
3377 G.last_exitcode = rcode = EXIT_SUCCESS;
3378 /* "if <false> THEN cmd": skip cmd */
3382 if (rword == RES_ELSE || rword == RES_ELIF) {
3383 /* "if <true> then ... ELSE/ELIF cmd":
3384 * skip cmd and all following ones */
3389 #if ENABLE_HUSH_LOOPS
3390 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3392 /* first loop through for */
3394 static const char encoded_dollar_at[] ALIGN1 = {
3395 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3396 }; /* encoded representation of "$@" */
3397 static const char *const encoded_dollar_at_argv[] = {
3398 encoded_dollar_at, NULL
3399 }; /* argv list with one element: "$@" */
3402 vals = (char**)encoded_dollar_at_argv;
3403 if (pi->next->res_word == RES_IN) {
3404 /* if no variable values after "in" we skip "for" */
3405 if (!pi->next->cmds[0].argv) {
3406 G.last_exitcode = rcode = EXIT_SUCCESS;
3407 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3410 vals = pi->next->cmds[0].argv;
3411 } /* else: "for var; do..." -> assume "$@" list */
3412 /* create list of variable values */
3413 debug_print_strings("for_list made from", vals);
3414 for_list = expand_strvec_to_strvec(vals);
3415 for_lcur = for_list;
3416 debug_print_strings("for_list", for_list);
3417 for_varname = pi->cmds[0].argv[0];
3418 pi->cmds[0].argv[0] = NULL;
3420 free(pi->cmds[0].argv[0]);
3422 /* "for" loop is over, clean up */
3426 pi->cmds[0].argv[0] = for_varname;
3429 /* Insert next value from for_lcur */
3430 //TODO: does it need escaping?
3431 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3432 pi->cmds[0].assignment_cnt = 1;
3434 if (rword == RES_IN) {
3435 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3437 if (rword == RES_DONE) {
3438 continue; /* "done" has no cmds too */
3441 #if ENABLE_HUSH_CASE
3442 if (rword == RES_CASE) {
3443 case_word = expand_strvec_to_string(pi->cmds->argv);
3446 if (rword == RES_MATCH) {
3449 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3451 /* all prev words didn't match, does this one match? */
3452 argv = pi->cmds->argv;
3454 char *pattern = expand_string_to_string(*argv);
3455 /* TODO: which FNM_xxx flags to use? */
3456 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3458 if (cond_code == 0) { /* match! we will execute this branch */
3459 free(case_word); /* make future "word)" stop */
3467 if (rword == RES_CASEI) { /* inside of a case branch */
3469 continue; /* not matched yet, skip this pipe */
3472 /* Just pressing <enter> in shell should check for jobs.
3473 * OTOH, in non-interactive shell this is useless
3474 * and only leads to extra job checks */
3475 if (pi->num_cmds == 0) {
3476 if (G_interactive_fd)
3477 goto check_jobs_and_continue;
3481 /* After analyzing all keywords and conditions, we decided
3482 * to execute this pipe. NB: have to do checkjobs(NULL)
3483 * after run_pipe to collect any background children,
3484 * even if list execution is to be stopped. */
3485 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3488 #if ENABLE_HUSH_LOOPS
3489 G.flag_break_continue = 0;
3491 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3493 /* We only ran a builtin: rcode is already known
3494 * and we don't need to wait for anything. */
3495 G.last_exitcode = rcode;
3496 debug_printf_exec(": builtin exitcode %d\n", rcode);
3497 check_and_run_traps(0);
3498 #if ENABLE_HUSH_LOOPS
3499 /* Was it "break" or "continue"? */
3500 if (G.flag_break_continue) {
3501 smallint fbc = G.flag_break_continue;
3502 /* We might fall into outer *loop*,
3503 * don't want to break it too */
3505 G.depth_break_continue--;
3506 if (G.depth_break_continue == 0)
3507 G.flag_break_continue = 0;
3508 /* else: e.g. "continue 2" should *break* once, *then* continue */
3509 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3510 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3511 goto check_jobs_and_break;
3512 /* "continue": simulate end of loop */
3517 } else if (pi->followup == PIPE_BG) {
3518 /* What does bash do with attempts to background builtins? */
3519 /* even bash 3.2 doesn't do that well with nested bg:
3520 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3521 * I'm NOT treating inner &'s as jobs */
3522 check_and_run_traps(0);
3524 if (G.run_list_level == 1)
3527 G.last_exitcode = rcode = EXIT_SUCCESS;
3528 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3531 if (G.run_list_level == 1 && G_interactive_fd) {
3532 /* Waits for completion, then fg's main shell */
3533 rcode = checkjobs_and_fg_shell(pi);
3534 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3535 check_and_run_traps(0);
3538 { /* This one just waits for completion */
3539 rcode = checkjobs(pi);
3540 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3541 check_and_run_traps(0);
3543 G.last_exitcode = rcode;
3547 /* Analyze how result affects subsequent commands */
3549 if (rword == RES_IF || rword == RES_ELIF)
3552 #if ENABLE_HUSH_LOOPS
3553 /* Beware of "while false; true; do ..."! */
3554 if (pi->next && pi->next->res_word == RES_DO) {
3555 if (rword == RES_WHILE) {
3557 /* "while false; do...done" - exitcode 0 */
3558 G.last_exitcode = rcode = EXIT_SUCCESS;
3559 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3560 goto check_jobs_and_break;
3563 if (rword == RES_UNTIL) {
3565 debug_printf_exec(": until expr is true: breaking\n");
3566 check_jobs_and_break:
3574 check_jobs_and_continue:
3579 //// if (G.ctrl_z_flag) {
3580 //// /* ctrl-Z forked somewhere in the past, we are the child,
3581 //// * and now we completed running the list. Exit. */
3587 //// if (!G.run_list_level && G_interactive_fd) {
3588 //// signal(SIGTSTP, SIG_IGN);
3589 //// signal(SIGINT, SIG_IGN);
3592 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
3593 #if ENABLE_HUSH_LOOPS
3598 #if ENABLE_HUSH_CASE
3604 /* Select which version we will use */
3605 static int run_and_free_list(struct pipe *pi)
3608 debug_printf_exec("run_and_free_list entered\n");
3610 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
3611 rcode = run_list(pi);
3613 /* free_pipe_list has the side effect of clearing memory.
3614 * In the long run that function can be merged with run_list,
3615 * but doing that now would hobble the debugging effort. */
3616 free_pipe_list(pi, /* indent: */ 0);
3617 debug_printf_exec("run_and_free_list return %d\n", rcode);
3622 static struct pipe *new_pipe(void)
3625 pi = xzalloc(sizeof(struct pipe));
3626 /*pi->followup = 0; - deliberately invalid value */
3627 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3631 /* Command (member of a pipe) is complete. The only possible error here
3632 * is out of memory, in which case xmalloc exits. */
3633 static int done_command(struct parse_context *ctx)
3635 /* The command is really already in the pipe structure, so
3636 * advance the pipe counter and make a new, null command. */
3637 struct pipe *pi = ctx->pipe;
3638 struct command *command = ctx->command;
3641 if (command->group == NULL
3642 && command->argv == NULL
3643 && command->redirects == NULL
3645 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3646 memset(command, 0, sizeof(*command)); /* paranoia */
3647 return pi->num_cmds;
3650 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3651 //debug_print_tree(ctx->list_head, 20);
3653 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3656 /* Only real trickiness here is that the uncommitted
3657 * command structure is not counted in pi->num_cmds. */
3658 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3659 command = &pi->cmds[pi->num_cmds];
3660 memset(command, 0, sizeof(*command));
3662 ctx->command = command;
3663 /* but ctx->pipe and ctx->list_head remain unchanged */
3665 return pi->num_cmds; /* used only for 0/nonzero check */
3668 static void done_pipe(struct parse_context *ctx, pipe_style type)
3672 debug_printf_parse("done_pipe entered, followup %d\n", type);
3673 /* Close previous command */
3674 not_null = done_command(ctx);
3675 ctx->pipe->followup = type;
3677 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3678 ctx->ctx_inverted = 0;
3679 ctx->pipe->res_word = ctx->ctx_res_w;
3682 /* Without this check, even just <enter> on command line generates
3683 * tree of three NOPs (!). Which is harmless but annoying.
3684 * IOW: it is safe to do it unconditionally.
3685 * RES_NONE case is for "for a in; do ..." (empty IN set)
3686 * and other cases to work. */
3689 || ctx->ctx_res_w == RES_FI
3690 || ctx->ctx_res_w == RES_DONE
3691 || ctx->ctx_res_w == RES_FOR
3692 || ctx->ctx_res_w == RES_IN
3693 || ctx->ctx_res_w == RES_ESAC
3697 debug_printf_parse("done_pipe: adding new pipe: "
3698 "not_null:%d ctx->ctx_res_w:%d\n",
3699 not_null, ctx->ctx_res_w);
3701 ctx->pipe->next = new_p;
3703 /* RES_THEN, RES_DO etc are "sticky" -
3704 * they remain set for commands inside if/while.
3705 * This is used to control execution.
3706 * RES_FOR and RES_IN are NOT sticky (needed to support
3707 * cases where variable or value happens to match a keyword):
3709 #if ENABLE_HUSH_LOOPS
3710 if (ctx->ctx_res_w == RES_FOR
3711 || ctx->ctx_res_w == RES_IN)
3712 ctx->ctx_res_w = RES_NONE;
3714 #if ENABLE_HUSH_CASE
3715 if (ctx->ctx_res_w == RES_MATCH)
3716 ctx->ctx_res_w = RES_CASEI;
3718 ctx->command = NULL; /* trick done_command below */
3719 /* Create the memory for command, roughly:
3720 * ctx->pipe->cmds = new struct command;
3721 * ctx->command = &ctx->pipe->cmds[0];
3724 //debug_print_tree(ctx->list_head, 10);
3726 debug_printf_parse("done_pipe return\n");
3729 static void initialize_context(struct parse_context *ctx)
3731 memset(ctx, 0, sizeof(*ctx));
3732 ctx->pipe = ctx->list_head = new_pipe();
3733 /* Create the memory for command, roughly:
3734 * ctx->pipe->cmds = new struct command;
3735 * ctx->command = &ctx->pipe->cmds[0];
3740 /* If a reserved word is found and processed, parse context is modified
3741 * and 1 is returned.
3744 struct reserved_combo {
3747 unsigned char assignment_flag;
3751 FLAG_END = (1 << RES_NONE ),
3753 FLAG_IF = (1 << RES_IF ),
3754 FLAG_THEN = (1 << RES_THEN ),
3755 FLAG_ELIF = (1 << RES_ELIF ),
3756 FLAG_ELSE = (1 << RES_ELSE ),
3757 FLAG_FI = (1 << RES_FI ),
3759 #if ENABLE_HUSH_LOOPS
3760 FLAG_FOR = (1 << RES_FOR ),
3761 FLAG_WHILE = (1 << RES_WHILE),
3762 FLAG_UNTIL = (1 << RES_UNTIL),
3763 FLAG_DO = (1 << RES_DO ),
3764 FLAG_DONE = (1 << RES_DONE ),
3765 FLAG_IN = (1 << RES_IN ),
3767 #if ENABLE_HUSH_CASE
3768 FLAG_MATCH = (1 << RES_MATCH),
3769 FLAG_ESAC = (1 << RES_ESAC ),
3771 FLAG_START = (1 << RES_XXXX ),
3774 static const struct reserved_combo* match_reserved_word(o_string *word)
3776 /* Mostly a list of accepted follow-up reserved words.
3777 * FLAG_END means we are done with the sequence, and are ready
3778 * to turn the compound list into a command.
3779 * FLAG_START means the word must start a new compound list.
3781 static const struct reserved_combo reserved_list[] = {
3783 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3784 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
3785 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3786 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
3787 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
3788 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3790 #if ENABLE_HUSH_LOOPS
3791 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3792 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3793 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
3794 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3795 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
3796 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3798 #if ENABLE_HUSH_CASE
3799 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3800 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3803 const struct reserved_combo *r;
3805 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3806 if (strcmp(word->data, r->literal) == 0)
3811 static int reserved_word(o_string *word, struct parse_context *ctx)
3813 #if ENABLE_HUSH_CASE
3814 static const struct reserved_combo reserved_match = {
3815 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3818 const struct reserved_combo *r;
3820 r = match_reserved_word(word);
3824 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3825 #if ENABLE_HUSH_CASE
3826 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
3827 /* "case word IN ..." - IN part starts first match part */
3828 r = &reserved_match;
3831 if (r->flag == 0) { /* '!' */
3832 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3833 syntax("! ! command");
3834 IF_HAS_KEYWORDS(ctx->ctx_res_w = RES_SNTX;)
3836 ctx->ctx_inverted = 1;
3839 if (r->flag & FLAG_START) {
3840 struct parse_context *old;
3841 old = xmalloc(sizeof(*old));
3842 debug_printf_parse("push stack %p\n", old);
3843 *old = *ctx; /* physical copy */
3844 initialize_context(ctx);
3846 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3848 ctx->ctx_res_w = RES_SNTX;
3851 ctx->ctx_res_w = r->res;
3852 ctx->old_flag = r->flag;
3853 if (ctx->old_flag & FLAG_END) {
3854 struct parse_context *old;
3855 done_pipe(ctx, PIPE_SEQ);
3856 debug_printf_parse("pop stack %p\n", ctx->stack);
3858 old->command->group = ctx->list_head;
3859 old->command->grp_type = GRP_NORMAL;
3861 o_addstr(&old->as_string, ctx->as_string.data);
3862 o_free_unsafe(&ctx->as_string);
3863 old->command->group_as_string = xstrdup(old->as_string.data);
3864 debug_printf_parse("pop, remembering as:'%s'\n",
3865 old->command->group_as_string);
3867 *ctx = *old; /* physical copy */
3870 word->o_assignment = r->assignment_flag;
3875 /* Word is complete, look at it and update parsing context.
3876 * Normal return is 0. Syntax errors return 1.
3877 * Note: on return, word is reset, but not o_free'd!
3879 static int done_word(o_string *word, struct parse_context *ctx)
3881 struct command *command = ctx->command;
3883 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3884 if (word->length == 0 && word->o_quoted == 0) {
3885 debug_printf_parse("done_word return 0: true null, ignored\n");
3888 /* If this word wasn't an assignment, next ones definitely
3889 * can't be assignments. Even if they look like ones. */
3890 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3891 && word->o_assignment != WORD_IS_KEYWORD
3893 word->o_assignment = NOT_ASSIGNMENT;
3895 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3896 command->assignment_cnt++;
3897 word->o_assignment = MAYBE_ASSIGNMENT;
3900 if (ctx->pending_redirect) {
3901 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3902 * only if run as "bash", not "sh" */
3903 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3905 * ...the word that follows the redirection operator
3906 * shall be subjected to tilde expansion, parameter expansion,
3907 * command substitution, arithmetic expansion, and quote
3908 * removal. Pathname expansion shall not be performed
3909 * on the word by a non-interactive shell; an interactive
3910 * shell may perform it, but shall do so only when
3911 * the expansion would result in one word."
3913 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3914 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
3917 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3919 word->o_assignment = NOT_ASSIGNMENT;
3920 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3922 /* "{ echo foo; } echo bar" - bad */
3923 /* NB: bash allows e.g.:
3924 * if true; then { echo foo; } fi
3925 * while if false; then false; fi do break; done
3927 * while if false; then false; fi; do; break; done
3929 if (command->group) {
3931 debug_printf_parse("done_word return 1: syntax error, "
3932 "groups and arglists don't mix\n");
3936 #if ENABLE_HUSH_CASE
3937 if (ctx->ctx_dsemicolon
3938 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3940 /* already done when ctx_dsemicolon was set to 1: */
3941 /* ctx->ctx_res_w = RES_MATCH; */
3942 ctx->ctx_dsemicolon = 0;
3945 if (!command->argv /* if it's the first word... */
3946 #if ENABLE_HUSH_LOOPS
3947 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3948 && ctx->ctx_res_w != RES_IN
3951 debug_printf_parse(": checking '%s' for reserved-ness\n", word->data);
3952 if (reserved_word(word, ctx)) {
3954 debug_printf_parse("done_word return %d\n",
3955 (ctx->ctx_res_w == RES_SNTX));
3956 return (ctx->ctx_res_w == RES_SNTX);
3960 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
3961 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3962 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3963 /* (otherwise it's known to be not empty and is already safe) */
3965 /* exclude "$@" - it can expand to no word despite "" */
3966 char *p = word->data;
3967 while (p[0] == SPECIAL_VAR_SYMBOL
3968 && (p[1] & 0x7f) == '@'
3969 && p[2] == SPECIAL_VAR_SYMBOL
3973 if (p == word->data || p[0] != '\0') {
3974 /* saw no "$@", or not only "$@" but some
3975 * real text is there too */
3976 /* insert "empty variable" reference, this makes
3977 * e.g. "", $empty"" etc to not disappear */
3978 o_addchr(word, SPECIAL_VAR_SYMBOL);
3979 o_addchr(word, SPECIAL_VAR_SYMBOL);
3982 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3983 debug_print_strings("word appended to argv", command->argv);
3987 ctx->pending_redirect = NULL;
3989 #if ENABLE_HUSH_LOOPS
3990 /* Force FOR to have just one word (variable name) */
3991 /* NB: basically, this makes hush see "for v in ..." syntax as if
3992 * as it is "for v; in ...". FOR and IN become two pipe structs
3994 if (ctx->ctx_res_w == RES_FOR) {
3995 //TODO: check that command->argv[0] is a valid variable name!
3996 done_pipe(ctx, PIPE_SEQ);
3999 #if ENABLE_HUSH_CASE
4000 /* Force CASE to have just one word */
4001 if (ctx->ctx_res_w == RES_CASE) {
4002 done_pipe(ctx, PIPE_SEQ);
4005 debug_printf_parse("done_word return 0\n");
4010 /* Peek ahead in the input to find out if we have a "&n" construct,
4011 * as in "2>&1", that represents duplicating a file descriptor.
4012 * Return: REDIRFD_CLOSE (-3) if >&- "close fd" construct is seen,
4013 * -2 (syntax error), -1 if no & was seen, or the number found.
4016 #define redirect_dup_num(as_string, input) \
4017 redirect_dup_num(input)
4019 static int redirect_dup_num(o_string *as_string, struct in_str *input)
4027 ch = i_getch(input); /* get the & */
4028 nommu_addchr(as_string, ch);
4031 ch = i_getch(input);
4032 nommu_addchr(as_string, ch);
4033 return REDIRFD_CLOSE;
4037 while (ch != EOF && isdigit(ch)) {
4038 d = d*10 + (ch-'0');
4040 ch = i_getch(input);
4041 nommu_addchr(as_string, ch);
4046 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4048 bb_error_msg("ambiguous redirect");
4052 /* Return code is 0 normally, 1 if a syntax error is detected
4054 static int parse_redirect(struct parse_context *ctx,
4057 struct in_str *input)
4059 struct command *command = ctx->command;
4060 struct redir_struct *redir;
4061 struct redir_struct **redirp;
4065 if (style != REDIRECT_HEREDOC) {
4066 /* Check for a '2>&1' type redirect */
4067 dup_num = redirect_dup_num(&ctx->as_string, input);
4069 return 1; /* syntax error */
4071 int ch = i_peek(input);
4072 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4073 if (dup_num) { /* <<-... */
4074 ch = i_getch(input);
4075 nommu_addchr(&ctx->as_string, ch);
4078 /* <<[-] word is the same as <<[-]word */
4079 while (ch == ' ' || ch == '\t') {
4080 ch = i_getch(input);
4081 nommu_addchr(&ctx->as_string, ch);
4086 if (style == REDIRECT_OVERWRITE && dup_num == -1) {
4087 int ch = i_peek(input);
4089 /* >|FILE redirect ("clobbering" >).
4090 * Since we do not support "set -o noclobber" yet,
4091 * >| and > are the same for now. Just eat |.
4093 ch = i_getch(input);
4094 nommu_addchr(&ctx->as_string, ch);
4098 /* Create a new redir_struct and append it to the linked list */
4099 redirp = &command->redirects;
4100 while ((redir = *redirp) != NULL) {
4101 redirp = &(redir->next);
4103 *redirp = redir = xzalloc(sizeof(*redir));
4104 /* redir->next = NULL; */
4105 /* redir->rd_filename = NULL; */
4106 redir->rd_type = style;
4107 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4109 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4110 redir_table[style].descrip);
4112 redir->rd_dup = dup_num;
4113 if (style != REDIRECT_HEREDOC && dup_num != -1) {
4114 /* Erik had a check here that the file descriptor in question
4115 * is legit; I postpone that to "run time"
4116 * A "-" representation of "close me" shows up as a -3 here */
4117 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4118 redir->rd_fd, redir->rd_dup);
4120 /* Set ctx->pending_redirect, so we know what to do at the
4121 * end of the next parsed word. */
4122 ctx->pending_redirect = redir;
4127 /* If a redirect is immediately preceded by a number, that number is
4128 * supposed to tell which file descriptor to redirect. This routine
4129 * looks for such preceding numbers. In an ideal world this routine
4130 * needs to handle all the following classes of redirects...
4131 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4132 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4133 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4134 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4136 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4138 * ... If n is quoted, the number shall not be recognized as part of
4139 * the redirection expression. For example:
4141 * writes the character 2 into file a"
4142 * We are getting it right by setting ->o_quoted on any \<char>
4144 * A -1 return means no valid number was found,
4145 * the caller should use the appropriate default for this redirection.
4147 static int redirect_opt_num(o_string *o)
4151 if (o->data == NULL)
4153 num = bb_strtou(o->data, NULL, 10);
4154 if (errno || num < 0)
4161 #define fetch_till_str(as_string, input, word, skip_tabs) \
4162 fetch_till_str(input, word, skip_tabs)
4164 static char *fetch_till_str(o_string *as_string,
4165 struct in_str *input,
4169 o_string heredoc = NULL_O_STRING;
4175 ch = i_getch(input);
4176 nommu_addchr(as_string, ch);
4178 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4179 heredoc.data[past_EOL] = '\0';
4180 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4181 return heredoc.data;
4184 o_addchr(&heredoc, ch);
4185 past_EOL = heredoc.length;
4188 ch = i_getch(input);
4189 nommu_addchr(as_string, ch);
4190 } while (skip_tabs && ch == '\t');
4191 } while (ch == '\n');
4194 o_free_unsafe(&heredoc);
4197 o_addchr(&heredoc, ch);
4198 nommu_addchr(as_string, ch);
4202 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4203 * and load them all. There should be exactly heredoc_cnt of them.
4205 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4207 struct pipe *pi = ctx->list_head;
4211 struct command *cmd = pi->cmds;
4213 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4215 cmd->argv ? cmd->argv[0] : "NONE");
4216 for (i = 0; i < pi->num_cmds; i++) {
4217 struct redir_struct *redir = cmd->redirects;
4219 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4220 i, cmd->argv ? cmd->argv[0] : "NONE");
4222 if (redir->rd_type == REDIRECT_HEREDOC) {
4225 if (heredoc_cnt <= 0) {
4226 syntax("heredoc BUG 1");
4227 return 1; /* error */
4229 redir->rd_type = REDIRECT_HEREDOC2;
4230 /* redir->dup is (ab)used to indicate <<- */
4231 p = fetch_till_str(&ctx->as_string, input,
4232 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4234 syntax("unexpected EOF in here document");
4237 free(redir->rd_filename);
4238 redir->rd_filename = p;
4241 redir = redir->next;
4247 /* Should be 0. If it isn't, it's a parse error */
4249 syntax("heredoc BUG 2");
4255 #define parse_stream(pstring, input, end_trigger) \
4256 parse_stream(input, end_trigger)
4258 static struct pipe *parse_stream(char **pstring,
4259 struct in_str *input,
4261 static void parse_and_run_string(const char *s);
4263 #if ENABLE_HUSH_TICK
4264 static FILE *generate_stream_from_string(const char *s)
4267 int pid, channel[2];
4270 pid = BB_MMU ? fork() : vfork();
4272 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4274 if (pid == 0) { /* child */
4275 disable_restore_tty_pgrp_on_exit();
4276 /* Process substitution is not considered to be usual
4277 * 'command execution'.
4278 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4285 close(channel[0]); /* NB: close _first_, then move fd! */
4286 xmove_fd(channel[1], 1);
4287 /* Prevent it from trying to handle ctrl-z etc */
4288 USE_HUSH_JOB(G.run_list_level = 1;)
4290 reset_traps_to_defaults();
4291 parse_and_run_string(s);
4292 _exit(G.last_exitcode);
4294 /* We re-execute after vfork on NOMMU. This makes this script safe:
4295 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4296 * huge=`cat BIG` # was blocking here forever
4299 re_execute_shell(s, 0);
4304 enable_restore_tty_pgrp_on_exit();
4305 clean_up_after_re_execute();
4307 pf = fdopen(channel[0], "r");
4311 /* Return code is exit status of the process that is run. */
4312 static int process_command_subs(o_string *dest, const char *s)
4315 struct in_str pipe_str;
4318 pf = generate_stream_from_string(s);
4321 close_on_exec_on(fileno(pf));
4323 /* Now send results of command back into original context */
4324 setup_file_in_str(&pipe_str, pf);
4326 while ((ch = i_getch(&pipe_str)) != EOF) {
4332 o_addchr(dest, '\n');
4335 o_addQchr(dest, ch);
4338 debug_printf("done reading from pipe, pclose()ing\n");
4339 /* Note: we got EOF, and we just close the read end of the pipe.
4340 * We do not wait for the `cmd` child to terminate. bash and ash do.
4342 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4343 * `false`; echo $? - bash outputs "1"
4346 debug_printf("closed FILE from child. return 0\n");
4351 static int parse_group(o_string *dest, struct parse_context *ctx,
4352 struct in_str *input, int ch)
4354 /* dest contains characters seen prior to ( or {.
4355 * Typically it's empty, but for function defs,
4356 * it contains function name (without '()'). */
4357 struct pipe *pipe_list;
4359 struct command *command = ctx->command;
4361 debug_printf_parse("parse_group entered\n");
4362 #if ENABLE_HUSH_FUNCTIONS
4363 if (ch == 'F') { /* function definition? */
4364 bb_error_msg("aha '%s' is a function, parsing it...", dest->data);
4365 //command->fname = dest->data;
4366 command->grp_type = GRP_FUNCTION;
4367 //TODO: review every o_reset() location... do they handle all o_string fields correctly?
4368 memset(dest, 0, sizeof(*dest));
4371 if (command->argv /* word [word](... */
4372 || dest->length /* word(... */
4373 || dest->o_quoted /* ""(... */
4376 debug_printf_parse("parse_group return 1: "
4377 "syntax error, groups and arglists don't mix\n");
4383 command->grp_type = GRP_SUBSHELL;
4387 char *as_string = NULL;
4389 pipe_list = parse_stream(&as_string, input, endch);
4392 o_addstr(&ctx->as_string, as_string);
4394 /* empty ()/{} or parse error? */
4395 if (!pipe_list || pipe_list == ERR_PTR) {
4400 debug_printf_parse("parse_group return 1: "
4401 "parse_stream returned %p\n", pipe_list);
4404 command->group = pipe_list;
4406 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4407 command->group_as_string = as_string;
4408 debug_printf_parse("end of group, remembering as:'%s'\n",
4409 command->group_as_string);
4412 debug_printf_parse("parse_group return 0\n");
4414 /* command remains "open", available for possible redirects */
4417 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4418 /* Subroutines for copying $(...) and `...` things */
4419 static int add_till_backquote(o_string *dest, struct in_str *input);
4421 static int add_till_single_quote(o_string *dest, struct in_str *input)
4424 int ch = i_getch(input);
4426 syntax("unterminated '");
4434 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4435 static int add_till_double_quote(o_string *dest, struct in_str *input)
4438 int ch = i_getch(input);
4440 syntax("unterminated \"");
4445 if (ch == '\\') { /* \x. Copy both chars. */
4447 ch = i_getch(input);
4451 if (add_till_backquote(dest, input))
4456 //if (ch == '$') ...
4459 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4461 * "Within the backquoted style of command substitution, backslash
4462 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4463 * The search for the matching backquote shall be satisfied by the first
4464 * backquote found without a preceding backslash; during this search,
4465 * if a non-escaped backquote is encountered within a shell comment,
4466 * a here-document, an embedded command substitution of the $(command)
4467 * form, or a quoted string, undefined results occur. A single-quoted
4468 * or double-quoted string that begins, but does not end, within the
4469 * "`...`" sequence produces undefined results."
4471 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4473 static int add_till_backquote(o_string *dest, struct in_str *input)
4476 int ch = i_getch(input);
4478 syntax("unterminated `");
4484 /* \x. Copy both chars unless it is \` */
4485 int ch2 = i_getch(input);
4487 syntax("unterminated `");
4490 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4497 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4498 * quoting and nested ()s.
4499 * "With the $(command) style of command substitution, all characters
4500 * following the open parenthesis to the matching closing parenthesis
4501 * constitute the command. Any valid shell script can be used for command,
4502 * except a script consisting solely of redirections which produces
4503 * unspecified results."
4505 * echo $(echo '(TEST)' BEST) (TEST) BEST
4506 * echo $(echo 'TEST)' BEST) TEST) BEST
4507 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4509 static int add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4513 int ch = i_getch(input);
4515 syntax("unterminated )");
4524 if (i_peek(input) == ')') {
4532 if (add_till_single_quote(dest, input))
4538 if (add_till_double_quote(dest, input))
4544 /* \x. Copy verbatim. Important for \(, \) */
4545 ch = i_getch(input);
4547 syntax("unterminated )");
4556 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
4558 /* Return code: 0 for OK, 1 for syntax error */
4560 #define handle_dollar(as_string, dest, input) \
4561 handle_dollar(dest, input)
4563 static int handle_dollar(o_string *as_string,
4565 struct in_str *input)
4568 int ch = i_peek(input); /* first character after the $ */
4569 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
4571 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
4573 ch = i_getch(input);
4574 nommu_addchr(as_string, ch);
4576 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4578 debug_printf_parse(": '%c'\n", ch);
4579 o_addchr(dest, ch | quote_mask);
4582 if (!isalnum(ch) && ch != '_')
4584 ch = i_getch(input);
4585 nommu_addchr(as_string, ch);
4587 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4588 } else if (isdigit(ch)) {
4590 ch = i_getch(input);
4591 nommu_addchr(as_string, ch);
4592 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4593 debug_printf_parse(": '%c'\n", ch);
4594 o_addchr(dest, ch | quote_mask);
4595 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4596 } else switch (ch) {
4598 case '!': /* last bg pid */
4599 case '?': /* last exit code */
4600 case '#': /* number of args */
4601 case '*': /* args */
4602 case '@': /* args */
4603 goto make_one_char_var;
4605 bool first_char, all_digits;
4607 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4608 ch = i_getch(input);
4609 nommu_addchr(as_string, ch);
4610 /* XXX maybe someone will try to escape the '}' */
4615 ch = i_getch(input);
4616 nommu_addchr(as_string, ch);
4622 /* ${#var}: length of var contents */
4624 else if (isdigit(ch)) {
4631 && ( (all_digits && !isdigit(ch))
4632 || (!all_digits && !isalnum(ch) && ch != '_')
4635 /* handle parameter expansions
4636 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4641 case ':': /* null modifier */
4642 if (expansion == 0) {
4643 debug_printf_parse(": null modifier\n");
4648 case '#': /* remove prefix */
4649 case '%': /* remove suffix */
4650 if (expansion == 0) {
4651 debug_printf_parse(": remove suffix/prefix\n");
4656 case '-': /* default value */
4657 case '=': /* assign default */
4658 case '+': /* alternative */
4659 case '?': /* error indicate */
4660 debug_printf_parse(": parameter expansion\n");
4665 syntax("unterminated ${name}");
4666 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
4671 debug_printf_parse(": '%c'\n", ch);
4672 o_addchr(dest, ch | quote_mask);
4676 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4679 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
4684 ch = i_getch(input);
4685 nommu_addchr(as_string, ch);
4686 # if ENABLE_SH_MATH_SUPPORT
4687 if (i_peek(input) == '(') {
4688 ch = i_getch(input);
4689 nommu_addchr(as_string, ch);
4690 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4691 o_addchr(dest, /*quote_mask |*/ '+');
4695 if (add_till_closing_paren(dest, input, true))
4699 o_addstr(as_string, dest->data + pos);
4700 o_addchr(as_string, ')');
4701 o_addchr(as_string, ')');
4704 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4708 # if ENABLE_HUSH_TICK
4709 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4710 o_addchr(dest, quote_mask | '`');
4714 if (add_till_closing_paren(dest, input, false))
4718 o_addstr(as_string, dest->data + pos);
4719 o_addchr(as_string, '`');
4722 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4728 ch = i_getch(input);
4729 nommu_addchr(as_string, ch);
4731 if (isalnum(ch)) { /* it's $_name or $_123 */
4737 /* $_ Shell or shell script name; or last cmd name */
4738 /* $- Option flags set by set builtin or shell options (-i etc) */
4740 o_addQchr(dest, '$');
4742 debug_printf_parse("handle_dollar return 0\n");
4747 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
4748 parse_stream_dquoted(dest, input, dquote_end)
4750 static int parse_stream_dquoted(o_string *as_string,
4752 struct in_str *input,
4759 ch = i_getch(input);
4761 nommu_addchr(as_string, ch);
4762 if (ch == dquote_end) { /* may be only '"' or EOF */
4763 if (dest->o_assignment == NOT_ASSIGNMENT)
4764 dest->o_escape ^= 1;
4765 debug_printf_parse("parse_stream_dquoted return 0\n");
4768 /* note: can't move it above ch == dquote_end check! */
4770 syntax("unterminated \"");
4771 debug_printf_parse("parse_stream_dquoted return 1: unterminated \"\n");
4776 next = i_peek(input);
4778 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4779 ch, ch, dest->o_escape);
4783 debug_printf_parse("parse_stream_dquoted return 1: \\<eof>\n");
4787 * "The backslash retains its special meaning [in "..."]
4788 * only when followed by one of the following characters:
4789 * $, `, ", \, or <newline>. A double quote may be quoted
4790 * within double quotes by preceding it with a backslash.
4791 * If enabled, history expansion will be performed unless
4792 * an ! appearing in double quotes is escaped using
4793 * a backslash. The backslash preceding the ! is not removed."
4795 if (strchr("$`\"\\", next) != NULL) {
4796 o_addqchr(dest, i_getch(input));
4798 o_addqchr(dest, '\\');
4803 if (handle_dollar(as_string, dest, input) != 0) {
4804 debug_printf_parse("parse_stream_dquoted return 1: "
4805 "handle_dollar returned non-0\n");
4810 #if ENABLE_HUSH_TICK
4812 //int pos = dest->length;
4813 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4814 o_addchr(dest, 0x80 | '`');
4815 if (add_till_backquote(dest, input))
4817 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4818 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4822 o_addQchr(dest, ch);
4824 && (dest->o_assignment == MAYBE_ASSIGNMENT
4825 || dest->o_assignment == WORD_IS_KEYWORD)
4826 && is_assignment(dest->data)
4828 dest->o_assignment = DEFINITELY_ASSIGNMENT;
4834 * Scan input until EOF or end_trigger char.
4835 * Return a list of pipes to execute, or NULL on EOF
4836 * or if end_trigger character is met.
4837 * On syntax error, exit is shell is not interactive,
4838 * reset parsing machinery and start parsing anew,
4839 * or return ERR_PTR.
4841 static struct pipe *parse_stream(char **pstring,
4842 struct in_str *input,
4845 struct parse_context ctx;
4846 o_string dest = NULL_O_STRING;
4850 /* Double-quote state is handled in the state variable is_in_dquote.
4851 * A single-quote triggers a bypass of the main loop until its mate is
4852 * found. When recursing, quote state is passed in via dest->o_escape.
4854 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4855 end_trigger ? : 'X');
4857 G.ifs = get_local_var_value("IFS");
4862 #if ENABLE_HUSH_INTERACTIVE
4863 input->promptmode = 0; /* PS1 */
4865 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
4866 initialize_context(&ctx);
4871 const char *is_special;
4875 redir_type redir_style;
4878 /* dest.o_quoted = 1; - already is (see below) */
4879 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
4882 /* We reached closing '"' */
4885 ch = i_getch(input);
4886 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4887 ch, ch, dest.o_escape);
4892 syntax("unterminated here document");
4895 if (done_word(&dest, &ctx)) {
4899 done_pipe(&ctx, PIPE_SEQ);
4901 /* If we got nothing... */
4902 // TODO: test script consisting of just "&"
4903 if (pi->num_cmds == 0
4904 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4906 free_pipe_list(pi, 0);
4909 debug_printf_parse("parse_stream return %p\n", pi);
4911 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4913 *pstring = ctx.as_string.data;
4915 o_free_unsafe(&ctx.as_string);
4919 nommu_addchr(&ctx.as_string, ch);
4920 is_ifs = strchr(G.ifs, ch);
4921 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
4922 "\\$\"" USE_HUSH_TICK("`") /* always special */
4925 if (!is_special && !is_ifs) { /* ordinary char */
4926 o_addQchr(&dest, ch);
4927 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4928 || dest.o_assignment == WORD_IS_KEYWORD)
4930 && is_assignment(dest.data)
4932 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4938 if (done_word(&dest, &ctx)) {
4942 #if ENABLE_HUSH_CASE
4943 /* "case ... in <newline> word) ..." -
4944 * newlines are ignored (but ';' wouldn't be) */
4945 if (ctx.command->argv == NULL
4946 && ctx.ctx_res_w == RES_MATCH
4951 /* Treat newline as a command separator. */
4952 done_pipe(&ctx, PIPE_SEQ);
4953 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4955 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4960 dest.o_assignment = MAYBE_ASSIGNMENT;
4962 /* note: if (is_ifs) continue;
4963 * will still trigger for us */
4966 if (end_trigger && end_trigger == ch
4967 && (heredoc_cnt == 0 || end_trigger != ';')
4969 //TODO: disallow "{ cmd }" without semicolon
4971 /* This is technically valid:
4972 * { cat <<HERE; }; echo Ok
4977 * but we don't support this.
4978 * We require heredoc to be in enclosing {}/(),
4981 syntax("unterminated here document");
4984 if (done_word(&dest, &ctx)) {
4987 done_pipe(&ctx, PIPE_SEQ);
4988 dest.o_assignment = MAYBE_ASSIGNMENT;
4989 /* Do we sit outside of any if's, loops or case's? */
4991 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4993 debug_printf_parse("parse_stream return %p: "
4994 "end_trigger char found\n",
4998 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5000 *pstring = ctx.as_string.data;
5002 o_free_unsafe(&ctx.as_string);
5004 return ctx.list_head;
5010 if (dest.o_assignment == MAYBE_ASSIGNMENT) {
5011 /* ch is a special char and thus this word
5012 * cannot be an assignment */
5013 dest.o_assignment = NOT_ASSIGNMENT;
5018 next = i_peek(input);
5023 if (dest.length == 0) {
5026 if (ch == EOF || ch == '\n')
5029 /* note: we do not add it to &ctx.as_string */
5031 nommu_addchr(&ctx.as_string, '\n');
5033 o_addQchr(&dest, ch);
5041 o_addchr(&dest, '\\');
5042 ch = i_getch(input);
5043 nommu_addchr(&ctx.as_string, ch);
5044 o_addchr(&dest, ch);
5045 /* Example: echo Hello \2>file
5046 * we need to know that word 2 is quoted */
5050 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5051 debug_printf_parse("parse_stream parse error: "
5052 "handle_dollar returned non-0\n");
5059 ch = i_getch(input);
5061 syntax("unterminated '");
5064 nommu_addchr(&ctx.as_string, ch);
5067 if (dest.o_assignment == NOT_ASSIGNMENT)
5068 o_addqchr(&dest, ch);
5070 o_addchr(&dest, ch);
5075 is_in_dquote ^= 1; /* invert */
5076 if (dest.o_assignment == NOT_ASSIGNMENT)
5079 #if ENABLE_HUSH_TICK
5084 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5085 o_addchr(&dest, '`');
5089 if (add_till_backquote(&dest, input))
5092 o_addstr(&ctx.as_string, dest.data + pos);
5093 o_addchr(&ctx.as_string, '`');
5095 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5096 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5101 redir_fd = redirect_opt_num(&dest);
5102 if (done_word(&dest, &ctx)) {
5105 redir_style = REDIRECT_OVERWRITE;
5107 redir_style = REDIRECT_APPEND;
5108 ch = i_getch(input);
5109 nommu_addchr(&ctx.as_string, ch);
5112 else if (next == '(') {
5113 syntax(">(process) not supported");
5117 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5121 redir_fd = redirect_opt_num(&dest);
5122 if (done_word(&dest, &ctx)) {
5125 redir_style = REDIRECT_INPUT;
5127 redir_style = REDIRECT_HEREDOC;
5129 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5130 ch = i_getch(input);
5131 nommu_addchr(&ctx.as_string, ch);
5132 } else if (next == '>') {
5133 redir_style = REDIRECT_IO;
5134 ch = i_getch(input);
5135 nommu_addchr(&ctx.as_string, ch);
5138 else if (next == '(') {
5139 syntax("<(process) not supported");
5143 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5147 #if ENABLE_HUSH_CASE
5150 if (done_word(&dest, &ctx)) {
5153 done_pipe(&ctx, PIPE_SEQ);
5154 #if ENABLE_HUSH_CASE
5155 /* Eat multiple semicolons, detect
5156 * whether it means something special */
5161 ch = i_getch(input);
5162 nommu_addchr(&ctx.as_string, ch);
5163 if (ctx.ctx_res_w == RES_CASEI) {
5164 ctx.ctx_dsemicolon = 1;
5165 ctx.ctx_res_w = RES_MATCH;
5171 /* We just finished a cmd. New one may start
5172 * with an assignment */
5173 dest.o_assignment = MAYBE_ASSIGNMENT;
5176 if (done_word(&dest, &ctx)) {
5180 ch = i_getch(input);
5181 nommu_addchr(&ctx.as_string, ch);
5182 done_pipe(&ctx, PIPE_AND);
5184 done_pipe(&ctx, PIPE_BG);
5188 if (done_word(&dest, &ctx)) {
5191 #if ENABLE_HUSH_CASE
5192 if (ctx.ctx_res_w == RES_MATCH)
5193 break; /* we are in case's "word | word)" */
5195 if (next == '|') { /* || */
5196 ch = i_getch(input);
5197 nommu_addchr(&ctx.as_string, ch);
5198 done_pipe(&ctx, PIPE_OR);
5200 /* we could pick up a file descriptor choice here
5201 * with redirect_opt_num(), but bash doesn't do it.
5202 * "echo foo 2| cat" yields "foo 2". */
5207 #if ENABLE_HUSH_CASE
5208 /* "case... in [(]word)..." - skip '(' */
5209 if (ctx.ctx_res_w == RES_MATCH
5210 && ctx.command->argv == NULL /* not (word|(... */
5211 && dest.length == 0 /* not word(... */
5212 && dest.o_quoted == 0 /* not ""(... */
5217 #if ENABLE_HUSH_FUNCTIONS
5218 if (dest.length != 0 /* not just () but word() */
5219 && dest.o_quoted == 0 /* not a"b"c() */
5220 && ctx.command->argv == NULL /* it's the first word */
5221 //TODO: "func ( ) {...}" - note spaces - is valid format too in bash
5222 && i_peek(input) == ')'
5223 && !match_reserved_word(&dest)
5225 bb_error_msg("seems like a function definition");
5227 //if !BB_MMU o_addchr(&ctx.as_string...
5229 //TODO: do it properly.
5230 ch = i_getch(input);
5231 } while (ch == ' ' || ch == '\n');
5233 syntax("was expecting {");
5236 ch = 'F'; /* magic value */
5240 if (parse_group(&dest, &ctx, input, ch) != 0) {
5245 #if ENABLE_HUSH_CASE
5246 if (ctx.ctx_res_w == RES_MATCH)
5250 /* proper use of this character is caught by end_trigger:
5251 * if we see {, we call parse_group(..., end_trigger='}')
5252 * and it will match } earlier (not here). */
5253 syntax("unexpected } or )");
5257 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5263 struct parse_context *pctx;
5264 IF_HAS_KEYWORDS(struct parse_context *p2;)
5266 /* Clean up allocated tree.
5267 * Samples for finding leaks on syntax error recovery path.
5268 * Run them from interactive shell, watch pmap `pidof hush`.
5269 * while if false; then false; fi do break; done
5271 * while if false; then false; fi; do break; fi
5272 * Samples to catch leaks at execution:
5273 * while if (true | {true;}); then echo ok; fi; do break; done
5274 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5278 /* Update pipe/command counts,
5279 * otherwise freeing may miss some */
5280 done_pipe(pctx, PIPE_SEQ);
5281 debug_printf_clean("freeing list %p from ctx %p\n",
5282 pctx->list_head, pctx);
5283 debug_print_tree(pctx->list_head, 0);
5284 free_pipe_list(pctx->list_head, 0);
5285 debug_printf_clean("freed list %p\n", pctx->list_head);
5287 o_free_unsafe(&pctx->as_string);
5289 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5293 IF_HAS_KEYWORDS(pctx = p2;)
5294 } while (HAS_KEYWORDS && pctx);
5295 /* Free text, clear all dest fields */
5297 /* If we are not in top-level parse, we return,
5298 * our caller will propagate error.
5300 if (end_trigger != ';') {
5307 /* Discard cached input, force prompt */
5309 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5314 /* Executing from string: eval, sh -c '...'
5315 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5316 * end_trigger controls how often we stop parsing
5317 * NUL: parse all, execute, return
5318 * ';': parse till ';' or newline, execute, repeat till EOF
5320 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5323 struct pipe *pipe_list;
5325 pipe_list = parse_stream(NULL, inp, end_trigger);
5326 if (!pipe_list) /* EOF */
5328 debug_print_tree(pipe_list, 0);
5329 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5330 run_and_free_list(pipe_list);
5334 static void parse_and_run_string(const char *s)
5336 struct in_str input;
5337 setup_string_in_str(&input, s);
5338 parse_and_run_stream(&input, '\0');
5341 static void parse_and_run_file(FILE *f)
5343 struct in_str input;
5344 setup_file_in_str(&input, f);
5345 parse_and_run_stream(&input, ';');
5348 /* Called a few times only (or even once if "sh -c") */
5349 static void block_signals(int second_time)
5354 mask = (1 << SIGQUIT);
5355 if (G_interactive_fd) {
5359 //TODO | (1 << SIGHUP)
5361 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
5366 G.non_DFL_mask = mask;
5369 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5373 sigaddset(&G.blocked_set, sig);
5377 sigdelset(&G.blocked_set, SIGCHLD);
5379 sigprocmask(SIG_SETMASK, &G.blocked_set,
5380 second_time ? NULL : &G.inherited_set);
5381 /* POSIX allows shell to re-enable SIGCHLD
5382 * even if it was SIG_IGN on entry */
5383 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5385 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5390 static void maybe_set_to_sigexit(int sig)
5392 void (*handler)(int);
5393 /* non_DFL_mask'ed signals are, well, masked,
5394 * no need to set handler for them.
5396 if (!((G.non_DFL_mask >> sig) & 1)) {
5397 handler = signal(sig, sigexit);
5398 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5399 signal(sig, handler);
5402 /* Set handlers to restore tty pgrp and exit */
5403 static void set_fatal_handlers(void)
5405 /* We _must_ restore tty pgrp on fatal signals */
5407 maybe_set_to_sigexit(SIGILL );
5408 maybe_set_to_sigexit(SIGFPE );
5409 maybe_set_to_sigexit(SIGBUS );
5410 maybe_set_to_sigexit(SIGSEGV);
5411 maybe_set_to_sigexit(SIGTRAP);
5412 } /* else: hush is perfect. what SEGV? */
5413 maybe_set_to_sigexit(SIGABRT);
5414 /* bash 3.2 seems to handle these just like 'fatal' ones */
5415 maybe_set_to_sigexit(SIGPIPE);
5416 maybe_set_to_sigexit(SIGALRM);
5417 //TODO: disable and move down when proper SIGHUP handling is added
5418 maybe_set_to_sigexit(SIGHUP );
5419 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5420 * if we aren't interactive... but in this case
5421 * we never want to restore pgrp on exit, and this fn is not called */
5422 /*maybe_set_to_sigexit(SIGTERM);*/
5423 /*maybe_set_to_sigexit(SIGINT );*/
5427 static int set_mode(const char cstate, const char mode)
5429 int state = (cstate == '-' ? 1 : 0);
5431 case 'n': G.fake_mode = state; break;
5432 case 'x': /*G.debug_mode = state;*/ break;
5433 default: return EXIT_FAILURE;
5435 return EXIT_SUCCESS;
5438 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5439 int hush_main(int argc, char **argv)
5441 static const struct variable const_shell_ver = {
5443 .varstr = (char*)hush_version_str,
5444 .max_len = 1, /* 0 can provoke free(name) */
5448 int signal_mask_is_inited = 0;
5451 struct variable *cur_var;
5454 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5455 G.last_exitcode = EXIT_SUCCESS;
5457 G.argv0_for_re_execing = argv[0];
5459 /* Deal with HUSH_VERSION */
5460 G.shell_ver = const_shell_ver; /* copying struct here */
5461 G.top_var = &G.shell_ver;
5462 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5463 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5464 /* Initialize our shell local variables with the values
5465 * currently living in the environment */
5466 cur_var = G.top_var;
5469 char *value = strchr(*e, '=');
5470 if (value) { /* paranoia */
5471 cur_var->next = xzalloc(sizeof(*cur_var));
5472 cur_var = cur_var->next;
5473 cur_var->varstr = *e;
5474 cur_var->max_len = strlen(*e);
5475 cur_var->flg_export = 1;
5479 debug_printf_env("putenv '%s'\n", hush_version_str);
5480 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5481 #if ENABLE_FEATURE_EDITING
5482 G.line_input_state = new_line_input_t(FOR_SHELL);
5484 G.global_argc = argc;
5485 G.global_argv = argv;
5486 /* Initialize some more globals to non-zero values */
5488 #if ENABLE_HUSH_INTERACTIVE
5489 if (ENABLE_FEATURE_EDITING)
5490 cmdedit_set_initial_prompt();
5494 /* Shell is non-interactive at first. We need to call
5495 * block_signals(0) if we are going to execute "sh <script>",
5496 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5497 * If we later decide that we are interactive, we run block_signals(0)
5498 * (or re-run block_signals(1) if we ran block_signals(0) before)
5499 * in order to intercept (more) signals.
5503 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5505 opt = getopt(argc, argv, "c:xins"
5515 G.root_pid = getpid();
5516 G.global_argv = argv + optind;
5517 if (!argv[optind]) {
5518 /* -c 'script' (no params): prevent empty $0 */
5519 *--G.global_argv = argv[0];
5521 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5522 G.global_argc = argc - optind;
5523 block_signals(0); /* 0: called 1st time */
5524 parse_and_run_string(optarg);
5527 /* Well, we cannot just declare interactiveness,
5528 * we have to have some stuff (ctty, etc) */
5529 /* G_interactive_fd++; */
5532 /* "-s" means "read from stdin", but this is how we always
5533 * operate, so simply do nothing here. */
5536 case '<': /* "big heredoc" support */
5537 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5540 G.root_pid = bb_strtou(optarg, &optarg, 16);
5542 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5544 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5545 # if ENABLE_HUSH_LOOPS
5547 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
5552 set_local_var(xstrdup(optarg), 0, opt == 'R');
5557 if (!set_mode('-', opt))
5561 fprintf(stderr, "Usage: sh [FILE]...\n"
5562 " or: sh -c command [args]...\n\n");
5568 } /* option parsing loop */
5571 G.root_pid = getpid();
5573 /* If we are login shell... */
5574 if (argv[0] && argv[0][0] == '-') {
5576 /* XXX what should argv be while sourcing /etc/profile? */
5577 debug_printf("sourcing /etc/profile\n");
5578 input = fopen_for_read("/etc/profile");
5579 if (input != NULL) {
5580 close_on_exec_on(fileno(input));
5581 block_signals(0); /* 0: called 1st time */
5582 signal_mask_is_inited = 1;
5583 parse_and_run_file(input);
5586 /* bash: after sourcing /etc/profile,
5587 * tries to source (in the given order):
5588 * ~/.bash_profile, ~/.bash_login, ~/.profile,
5589 * stopping of first found. --noprofile turns this off.
5590 * bash also sources ~/.bash_logout on exit.
5591 * If called as sh, skips .bash_XXX files.
5598 * "bash <script>" (which is never interactive (unless -i?))
5599 * sources $BASH_ENV here (without scanning $PATH).
5600 * If called as sh, does the same but with $ENV.
5602 debug_printf("running script '%s'\n", argv[optind]);
5603 G.global_argv = argv + optind;
5604 G.global_argc = argc - optind;
5605 input = xfopen_for_read(argv[optind]);
5606 close_on_exec_on(fileno(input));
5607 if (!signal_mask_is_inited)
5608 block_signals(0); /* 0: called 1st time */
5609 parse_and_run_file(input);
5610 #if ENABLE_FEATURE_CLEAN_UP
5616 /* Up to here, shell was non-interactive. Now it may become one.
5617 * NB: don't forget to (re)run block_signals(0/1) as needed.
5620 /* A shell is interactive if the '-i' flag was given, or if all of
5621 * the following conditions are met:
5623 * no arguments remaining or the -s flag given
5624 * standard input is a terminal
5625 * standard output is a terminal
5626 * Refer to Posix.2, the description of the 'sh' utility.
5629 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5630 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
5631 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
5632 //TODO: "interactive" and "have job control" are two different things.
5633 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
5634 //should stay on! Currently, we mix these into one.
5635 if (G.saved_tty_pgrp >= 0) {
5636 /* try to dup stdin to high fd#, >= 255 */
5637 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5638 if (G_interactive_fd < 0) {
5639 /* try to dup to any fd */
5640 G_interactive_fd = dup(STDIN_FILENO);
5641 if (G_interactive_fd < 0)
5643 G_interactive_fd = 0;
5645 // TODO: track & disallow any attempts of user
5646 // to (inadvertently) close/redirect it
5649 debug_printf("interactive_fd:%d\n", G_interactive_fd);
5650 if (G_interactive_fd) {
5653 /* We are indeed interactive shell, and we will perform
5654 * job control. Setting up for that. */
5656 close_on_exec_on(G_interactive_fd);
5657 /* If we were run as 'hush &', sleep until we are
5658 * in the foreground (tty pgrp == our pgrp).
5659 * If we get started under a job aware app (like bash),
5660 * make sure we are now in charge so we don't fight over
5661 * who gets the foreground */
5663 shell_pgrp = getpgrp();
5664 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
5665 if (G.saved_tty_pgrp == shell_pgrp)
5667 /* send TTIN to ourself (should stop us) */
5668 kill(- shell_pgrp, SIGTTIN);
5670 /* Block some signals */
5671 block_signals(signal_mask_is_inited);
5672 /* Set other signals to restore saved_tty_pgrp */
5673 set_fatal_handlers();
5674 /* Put ourselves in our own process group */
5675 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
5676 /* Grab control of the terminal */
5677 tcsetpgrp(G_interactive_fd, getpid());
5678 /* -1 is special - makes xfuncs longjmp, not exit
5679 * (we reset die_sleep = 0 whereever we [v]fork) */
5680 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
5681 if (setjmp(die_jmp)) {
5682 /* xfunc has failed! die die die */
5683 hush_exit(xfunc_error_retval);
5685 } else if (!signal_mask_is_inited) {
5686 block_signals(0); /* 0: called 1st time */
5687 } /* else: block_signals(0) was done before */
5688 #elif ENABLE_HUSH_INTERACTIVE
5689 /* No job control compiled in, only prompt/line editing */
5690 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
5691 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
5692 if (G_interactive_fd < 0) {
5693 /* try to dup to any fd */
5694 G_interactive_fd = dup(STDIN_FILENO);
5695 if (G_interactive_fd < 0)
5697 G_interactive_fd = 0;
5700 if (G_interactive_fd) {
5701 close_on_exec_on(G_interactive_fd);
5702 block_signals(signal_mask_is_inited);
5703 } else if (!signal_mask_is_inited) {
5707 /* We have interactiveness code disabled */
5708 if (!signal_mask_is_inited) {
5713 * if interactive but not a login shell, sources ~/.bashrc
5714 * (--norc turns this off, --rcfile <file> overrides)
5717 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
5718 printf("\n\n%s hush - the humble shell\n", bb_banner);
5719 printf("Enter 'help' for a list of built-in commands.\n\n");
5722 parse_and_run_file(stdin);
5725 #if ENABLE_FEATURE_CLEAN_UP
5726 if (G.cwd != bb_msg_unknown)
5728 cur_var = G.top_var->next;
5730 struct variable *tmp = cur_var;
5731 if (!cur_var->max_len)
5732 free(cur_var->varstr);
5733 cur_var = cur_var->next;
5737 hush_exit(G.last_exitcode);
5742 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5743 int lash_main(int argc, char **argv)
5745 //bb_error_msg("lash is deprecated, please use hush instead");
5746 return hush_main(argc, argv);
5754 static int builtin_trap(char **argv)
5761 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
5765 /* No args: print all trapped. This isn't 100% correct as we
5766 * should be escaping the cmd so that it can be pasted back in
5768 for (i = 0; i < NSIG; ++i)
5770 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
5771 return EXIT_SUCCESS;
5776 /* If first arg is decimal: reset all specified signals */
5777 sig = bb_strtou(*argv, NULL, 10);
5783 sig = get_signum(*argv++);
5784 if (sig < 0 || sig >= NSIG) {
5786 /* Mimic bash message exactly */
5787 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
5792 G.traps[sig] = xstrdup(new_cmd);
5794 debug_printf("trap: setting SIG%s (%i) to '%s'",
5795 get_signame(sig), sig, G.traps[sig]);
5797 /* There is no signal for 0 (EXIT) */
5802 sigaddset(&G.blocked_set, sig);
5804 /* There was a trap handler, we are removing it
5805 * (if sig has non-DFL handling,
5806 * we don't need to do anything) */
5807 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
5809 sigdelset(&G.blocked_set, sig);
5811 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5816 /* First arg is "-": reset all specified to default */
5817 /* First arg is "": ignore all specified */
5818 /* Everything else: execute first arg upon signal */
5820 bb_error_msg("trap: invalid arguments");
5821 return EXIT_FAILURE;
5823 if (NOT_LONE_DASH(*argv))
5829 static int builtin_true(char **argv UNUSED_PARAM)
5834 static int builtin_test(char **argv)
5841 return test_main(argc, argv - argc);
5844 static int builtin_echo(char **argv)
5851 return echo_main(argc, argv - argc);
5854 static int builtin_eval(char **argv)
5856 int rcode = EXIT_SUCCESS;
5859 char *str = expand_strvec_to_string(argv);
5861 * eval "echo Hi; done" ("done" is syntax error):
5862 * "echo Hi" will not execute too.
5864 parse_and_run_string(str);
5866 rcode = G.last_exitcode;
5871 static int builtin_cd(char **argv)
5873 const char *newdir = argv[1];
5874 if (newdir == NULL) {
5875 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
5876 * bash says "bash: cd: HOME not set" and does nothing (exitcode 1)
5878 newdir = getenv("HOME") ? : "/";
5880 if (chdir(newdir)) {
5881 /* Mimic bash message exactly */
5882 bb_perror_msg("cd: %s", newdir);
5883 return EXIT_FAILURE;
5886 return EXIT_SUCCESS;
5889 static int builtin_exec(char **argv)
5891 if (*++argv == NULL)
5892 return EXIT_SUCCESS; /* bash does this */
5897 // FIXME: if exec fails, bash does NOT exit! We do...
5898 pseudo_exec_argv(&dummy, argv, 0, NULL);
5903 static int builtin_exit(char **argv)
5905 debug_printf_exec("%s()\n", __func__);
5906 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
5907 //puts("exit"); /* bash does it */
5908 // TODO: warn if we have background jobs: "There are stopped jobs"
5909 // On second consecutive 'exit', exit anyway.
5910 if (*++argv == NULL)
5911 hush_exit(G.last_exitcode);
5912 /* mimic bash: exit 123abc == exit 255 + error msg */
5913 xfunc_error_retval = 255;
5914 /* bash: exit -2 == exit 254, no error msg */
5915 hush_exit(xatoi(*argv) & 0xff);
5918 static int builtin_export(char **argv)
5920 if (*++argv == NULL) {
5922 // ash emits: export VAR='VAL'
5923 // bash: declare -x VAR="VAL"
5924 // (both also escape as needed (quotes, $, etc))
5929 return EXIT_SUCCESS;
5936 value = strchr(name, '=');
5938 /* They are exporting something without a =VALUE */
5939 struct variable *var;
5941 var = get_local_var(name);
5943 var->flg_export = 1;
5944 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
5945 putenv(var->varstr);
5947 /* bash does not return an error when trying to export
5948 * an undefined variable. Do likewise. */
5951 set_local_var(xstrdup(name), 1, 0);
5954 return EXIT_SUCCESS;
5958 /* built-in 'fg' and 'bg' handler */
5959 static int builtin_fg_bg(char **argv)
5964 if (!G_interactive_fd)
5965 return EXIT_FAILURE;
5966 /* If they gave us no args, assume they want the last backgrounded task */
5968 for (pi = G.job_list; pi; pi = pi->next) {
5969 if (pi->jobid == G.last_jobid) {
5973 bb_error_msg("%s: no current job", argv[0]);
5974 return EXIT_FAILURE;
5976 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
5977 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
5978 return EXIT_FAILURE;
5980 for (pi = G.job_list; pi; pi = pi->next) {
5981 if (pi->jobid == jobnum) {
5985 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
5986 return EXIT_FAILURE;
5988 // TODO: bash prints a string representation
5989 // of job being foregrounded (like "sleep 1 | cat")
5990 if (argv[0][0] == 'f') {
5991 /* Put the job into the foreground. */
5992 tcsetpgrp(G_interactive_fd, pi->pgrp);
5995 /* Restart the processes in the job */
5996 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
5997 for (i = 0; i < pi->num_cmds; i++) {
5998 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
5999 pi->cmds[i].is_stopped = 0;
6001 pi->stopped_cmds = 0;
6003 i = kill(- pi->pgrp, SIGCONT);
6005 if (errno == ESRCH) {
6006 delete_finished_bg_job(pi);
6007 return EXIT_SUCCESS;
6009 bb_perror_msg("kill (SIGCONT)");
6012 if (argv[0][0] == 'f') {
6014 return checkjobs_and_fg_shell(pi);
6016 return EXIT_SUCCESS;
6020 #if ENABLE_HUSH_HELP
6021 static int builtin_help(char **argv UNUSED_PARAM)
6023 const struct built_in_command *x;
6026 "Built-in commands:\n"
6027 "------------------\n");
6028 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6029 printf("%s\t%s\n", x->cmd, x->descr);
6032 return EXIT_SUCCESS;
6037 static int builtin_jobs(char **argv UNUSED_PARAM)
6040 const char *status_string;
6042 for (job = G.job_list; job; job = job->next) {
6043 if (job->alive_cmds == job->stopped_cmds)
6044 status_string = "Stopped";
6046 status_string = "Running";
6048 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6050 return EXIT_SUCCESS;
6055 static int builtin_memleak(char **argv UNUSED_PARAM)
6060 /* Crude attempt to find where "free memory" starts,
6061 * sans fragmentation. */
6063 l = (unsigned long)p;
6066 if (l < (unsigned long)p) l = (unsigned long)p;
6069 if (!G.memleak_value)
6070 G.memleak_value = l;
6072 l -= G.memleak_value;
6079 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6084 static int builtin_pwd(char **argv UNUSED_PARAM)
6087 return EXIT_SUCCESS;
6090 static int builtin_read(char **argv)
6093 const char *name = argv[1] ? argv[1] : "REPLY";
6094 //TODO: check that argv[1] is a valid variable name
6096 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6097 return set_local_var(string, 0, 0);
6100 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6101 * built-in 'set' handler
6103 * set [-abCefhmnuvx] [-o option] [argument...]
6104 * set [+abCefhmnuvx] [+o option] [argument...]
6105 * set -- [argument...]
6108 * Implementations shall support the options in both their hyphen and
6109 * plus-sign forms. These options can also be specified as options to sh.
6111 * Write out all variables and their values: set
6112 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6113 * Turn on the -x and -v options: set -xv
6114 * Unset all positional parameters: set --
6115 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6116 * Set the positional parameters to the expansion of x, even if x expands
6117 * with a leading '-' or '+': set -- $x
6119 * So far, we only support "set -- [argument...]" and some of the short names.
6121 static int builtin_set(char **argv)
6124 char **pp, **g_argv;
6125 char *arg = *++argv;
6129 for (e = G.top_var; e; e = e->next)
6131 return EXIT_SUCCESS;
6135 if (!strcmp(arg, "--")) {
6140 if (arg[0] == '+' || arg[0] == '-') {
6141 for (n = 1; arg[n]; ++n)
6142 if (set_mode(arg[0], arg[n]))
6148 } while ((arg = *++argv) != NULL);
6149 /* Now argv[0] is 1st argument */
6151 /* Only reset global_argv if we didn't process anything */
6153 return EXIT_SUCCESS;
6156 /* NB: G.global_argv[0] ($0) is never freed/changed */
6157 g_argv = G.global_argv;
6158 if (G.global_args_malloced) {
6164 G.global_args_malloced = 1;
6165 pp = xzalloc(sizeof(pp[0]) * 2);
6166 pp[0] = g_argv[0]; /* retain $0 */
6169 /* This realloc's G.global_argv */
6170 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6177 return EXIT_SUCCESS;
6179 /* Nothing known, so abort */
6181 bb_error_msg("set: %s: invalid option", arg);
6182 return EXIT_FAILURE;
6185 static int builtin_shift(char **argv)
6191 if (n >= 0 && n < G.global_argc) {
6192 if (G.global_args_malloced) {
6195 free(G.global_argv[m++]);
6198 memmove(&G.global_argv[1], &G.global_argv[n+1],
6199 G.global_argc * sizeof(G.global_argv[0]));
6200 return EXIT_SUCCESS;
6202 return EXIT_FAILURE;
6205 static int builtin_source(char **argv)
6209 if (*++argv == NULL)
6210 return EXIT_FAILURE;
6212 /* XXX search through $PATH is missing */
6213 input = fopen_or_warn(*argv, "r");
6215 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6216 return EXIT_FAILURE;
6218 close_on_exec_on(fileno(input));
6220 /* Now run the file */
6222 /* XXX argv and argc are broken; need to save old G.global_argv
6223 * (pointer only is OK!) on this stack frame,
6224 * set G.global_argv=argv+1, recurse, and restore. */
6225 parse_and_run_file(input);
6227 return G.last_exitcode;
6230 static int builtin_umask(char **argv)
6233 const char *arg = argv[1];
6235 //TODO: umask may take chmod-like symbolic masks
6236 new_umask = bb_strtou(arg, NULL, 8);
6238 //Message? bash examples:
6239 //bash: umask: 'q': invalid symbolic mode operator
6240 //bash: umask: 999: octal number out of range
6241 return EXIT_FAILURE;
6244 new_umask = umask(0);
6245 printf("%.3o\n", (unsigned) new_umask);
6246 /* fall through and restore new_umask which we set to 0 */
6249 return EXIT_SUCCESS;
6252 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6253 static int builtin_unset(char **argv)
6259 return EXIT_SUCCESS;
6262 if (argv[0][0] == '-') {
6263 switch (argv[0][1]) {
6269 bb_error_msg("unset: %s: invalid option", *argv);
6270 return EXIT_FAILURE;
6272 //TODO: disallow "unset -vf ..." too
6279 if (unset_local_var(*argv)) {
6280 /* unset <nonexistent_var> doesn't fail.
6281 * Error is when one tries to unset RO var.
6282 * Message was printed by unset_local_var. */
6286 #if ENABLE_HUSH_FUNCTIONS
6288 unset_local_func(*argv);
6296 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6297 static int builtin_wait(char **argv)
6299 int ret = EXIT_SUCCESS;
6302 if (*++argv == NULL) {
6303 /* Don't care about wait results */
6304 /* Note 1: must wait until there are no more children */
6305 /* Note 2: must be interruptible */
6307 * $ sleep 3 & sleep 6 & wait
6312 * $ sleep 3 & sleep 6 & wait
6316 * ^C <-- after ~4 sec from keyboard
6319 sigaddset(&G.blocked_set, SIGCHLD);
6320 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6323 if (errno == ECHILD)
6325 /* Wait for SIGCHLD or any other signal of interest */
6326 /* sigtimedwait with infinite timeout: */
6327 sig = sigwaitinfo(&G.blocked_set, NULL);
6329 sig = check_and_run_traps(sig);
6330 if (sig && sig != SIGCHLD) { /* see note 2 */
6336 sigdelset(&G.blocked_set, SIGCHLD);
6337 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6341 /* This is probably buggy wrt interruptible-ness */
6343 pid_t pid = bb_strtou(*argv, NULL, 10);
6345 /* mimic bash message */
6346 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6347 return EXIT_FAILURE;
6349 if (waitpid(pid, &status, 0) == pid) {
6350 if (WIFSIGNALED(status))
6351 ret = 128 + WTERMSIG(status);
6352 else if (WIFEXITED(status))
6353 ret = WEXITSTATUS(status);
6357 bb_perror_msg("wait %s", *argv);
6366 #if ENABLE_HUSH_LOOPS
6367 static int builtin_break(char **argv)
6369 if (G.depth_of_loop == 0) {
6370 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6371 return EXIT_SUCCESS; /* bash compat */
6373 G.flag_break_continue++; /* BC_BREAK = 1 */
6374 G.depth_break_continue = 1;
6376 G.depth_break_continue = bb_strtou(argv[1], NULL, 10);
6377 if (errno || !G.depth_break_continue || argv[2]) {
6378 bb_error_msg("%s: bad arguments", argv[0]);
6379 G.flag_break_continue = BC_BREAK;
6380 G.depth_break_continue = UINT_MAX;
6383 if (G.depth_of_loop < G.depth_break_continue)
6384 G.depth_break_continue = G.depth_of_loop;
6385 return EXIT_SUCCESS;
6388 static int builtin_continue(char **argv)
6390 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6391 return builtin_break(argv);