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
45 * Bash stuff (maybe optionally enable?):
46 * &> and >& redirection of stdout+stderr
48 * reserved words: [[ ]] function select
49 * substrings ${var:1:5}
52 * grep for "TODO" and fix (some of them are easy)
53 * change { and } from special chars to reserved words
54 * $var refs in function do not pick up values set by "var=val func"
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?
59 * separate job control from interactiveness
60 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
62 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
64 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
66 /* #include <dmalloc.h> */
73 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
77 /* Debug build knobs */
78 #define LEAK_HUNTING 0
79 #define BUILD_AS_NOMMU 0
80 /* Enable/disable sanity checks. Ok to enable in production,
81 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
82 * Keeping 1 for now even in released versions.
92 # define USE_FOR_NOMMU(...) __VA_ARGS__
93 # define USE_FOR_MMU(...)
96 #if defined SINGLE_APPLET_MAIN
97 /* STANDALONE does not make sense, and won't compile */
98 # undef CONFIG_FEATURE_SH_STANDALONE
99 # undef ENABLE_FEATURE_SH_STANDALONE
100 # undef USE_FEATURE_SH_STANDALONE
101 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
102 # define ENABLE_FEATURE_SH_STANDALONE 0
103 # define USE_FEATURE_SH_STANDALONE(...)
104 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
107 #if !ENABLE_HUSH_INTERACTIVE
108 # undef ENABLE_FEATURE_EDITING
109 # define ENABLE_FEATURE_EDITING 0
110 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
111 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
114 /* Do we support ANY keywords? */
115 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
116 # define HAS_KEYWORDS 1
117 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
118 # define IF_HAS_NO_KEYWORDS(...)
120 # define HAS_KEYWORDS 0
121 # define IF_HAS_KEYWORDS(...)
122 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
125 /* If you comment out one of these below, it will be #defined later
126 * to perform debug printfs to stderr: */
127 #define debug_printf(...) do {} while (0)
128 /* Finer-grained debug switches */
129 #define debug_printf_parse(...) do {} while (0)
130 #define debug_print_tree(a, b) do {} while (0)
131 #define debug_printf_exec(...) do {} while (0)
132 #define debug_printf_env(...) do {} while (0)
133 #define debug_printf_jobs(...) do {} while (0)
134 #define debug_printf_expand(...) do {} while (0)
135 #define debug_printf_glob(...) do {} while (0)
136 #define debug_printf_list(...) do {} while (0)
137 #define debug_printf_subst(...) do {} while (0)
138 #define debug_printf_clean(...) do {} while (0)
140 #define ERR_PTR ((void*)(long)1)
142 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
144 #define SPECIAL_VAR_SYMBOL 3
146 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
148 /* This supports saving pointers malloced in vfork child,
149 * to be freed in the parent.
152 typedef struct nommu_save_t {
156 char **argv_from_re_execing;
160 /* The descrip member of this structure is only used to make
161 * debugging output pretty */
162 static const struct {
164 signed char default_fd;
168 { O_RDONLY, 0, "<" },
169 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
170 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
171 { O_RDONLY, 0, "<<" },
172 { O_CREAT|O_RDWR, 1, "<>" },
173 /* Should not be needed. Bogus default_fd helps in debugging */
174 /* { O_RDONLY, 77, "<<" }, */
177 typedef enum reserved_style {
186 #if ENABLE_HUSH_LOOPS
193 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
198 /* two pseudo-keywords support contrived "case" syntax: */
199 RES_MATCH , /* "word)" */
200 RES_CASEI , /* "this command is inside CASE" */
207 typedef struct o_string {
209 int length; /* position where data is appended */
211 /* Protect newly added chars against globbing
212 * (by prepending \ to *, ?, [, \) */
215 /* At least some part of the string was inside '' or "",
216 * possibly empty one: word"", wo''rd etc. */
218 smallint has_empty_slot;
219 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
222 MAYBE_ASSIGNMENT = 0,
223 DEFINITELY_ASSIGNMENT = 1,
225 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
227 /* Used for initialization: o_string foo = NULL_O_STRING; */
228 #define NULL_O_STRING { NULL }
230 /* I can almost use ordinary FILE*. Is open_memstream() universally
231 * available? Where is it documented? */
232 typedef struct in_str {
234 /* eof_flag=1: last char in ->p is really an EOF */
235 char eof_flag; /* meaningless if ->p == NULL */
237 #if ENABLE_HUSH_INTERACTIVE
239 smallint promptmode; /* 0: PS1, 1: PS2 */
242 int (*get) (struct in_str *);
243 int (*peek) (struct in_str *);
245 #define i_getch(input) ((input)->get(input))
246 #define i_peek(input) ((input)->peek(input))
248 struct redir_struct {
249 struct redir_struct *next;
250 char *rd_filename; /* filename */
251 int rd_fd; /* fd to redirect */
252 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
254 smallint rd_type; /* (enum redir_type) */
255 /* note: for heredocs, rd_filename contains heredoc delimiter,
256 * and subsequently heredoc itself; and rd_dup is a bitmask:
257 * 1: do we need to trim leading tabs?
258 * 2: is heredoc quoted (<<'delim' syntax) ?
261 typedef enum redir_type {
262 REDIRECT_INVALID = 0,
264 REDIRECT_OVERWRITE = 2,
266 REDIRECT_HEREDOC = 4,
268 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
271 REDIRFD_SYNTAX_ERR = -2,
272 REDIRFD_TO_FILE = -1,
273 /* otherwise, rd_fd is redirected to rd_dup */
275 HEREDOC_SKIPTABS = 1,
281 pid_t pid; /* 0 if exited */
282 int assignment_cnt; /* how many argv[i] are assignments? */
283 smallint is_stopped; /* is the command currently running? */
284 smallint grp_type; /* GRP_xxx */
286 #define GRP_SUBSHELL 1
287 #if ENABLE_HUSH_FUNCTIONS
288 # define GRP_FUNCTION 2
290 struct pipe *group; /* if non-NULL, this "command" is { list },
291 * ( list ), or a compound statement */
293 char *group_as_string;
295 #if ENABLE_HUSH_FUNCTIONS
296 struct function *child_func;
297 /* This field is used to prevent a bug here:
298 * while...do f1() {a;}; f1; f1 {b;}; f1; done
299 * When we execute "f1() {a;}" cmd, we create new function and clear
300 * cmd->group, cmd->group_as_string, cmd->argv[0].
301 * when we execute "f1 {b;}", we notice that f1 exists,
302 * and that it's "parent cmd" struct is still "alive",
303 * we put those fields back into cmd->xxx
304 * (struct function has ->parent_cmd ptr to facilitate that).
305 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
306 * Without this trick, loop would execute a;b;b;b;...
307 * instead of correct sequence a;b;a;b;...
308 * When command is freed, it severs the link
309 * (sets ->child_func->parent_cmd to NULL).
312 char **argv; /* command name and arguments */
313 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
314 * and on execution these are substituted with their values.
315 * Substitution can make _several_ words out of one argv[n]!
316 * Example: argv[0]=='.^C*^C.' here: echo .$*.
317 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
319 struct redir_struct *redirects; /* I/O redirections */
321 /* Is there anything in this command at all? */
322 #define IS_NULL_CMD(cmd) \
323 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
328 int num_cmds; /* total number of commands in pipe */
329 int alive_cmds; /* number of commands running (not exited) */
330 int stopped_cmds; /* number of commands alive, but stopped */
332 int jobid; /* job number */
333 pid_t pgrp; /* process group ID for the job */
334 char *cmdtext; /* name of job */
336 struct command *cmds; /* array of commands in pipe */
337 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
338 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
339 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
341 typedef enum pipe_style {
347 /* Is there anything in this pipe at all? */
348 #define IS_NULL_PIPE(pi) \
349 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
351 /* This holds pointers to the various results of parsing */
352 struct parse_context {
353 /* linked list of pipes */
354 struct pipe *list_head;
355 /* last pipe (being constructed right now) */
357 /* last command in pipe (being constructed right now) */
358 struct command *command;
359 /* last redirect in command->redirects list */
360 struct redir_struct *pending_redirect;
366 smallint ctx_inverted; /* "! cmd | cmd" */
368 smallint ctx_dsemicolon; /* ";;" seen */
370 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
372 /* group we are enclosed in:
373 * example: "if pipe1; pipe2; then pipe3; fi"
374 * when we see "if" or "then", we malloc and copy current context,
375 * and make ->stack point to it. then we parse pipeN.
376 * when closing "then" / fi" / whatever is found,
377 * we move list_head into ->stack->command->group,
378 * copy ->stack into current context, and delete ->stack.
379 * (parsing of { list } and ( list ) doesn't use this method)
381 struct parse_context *stack;
385 /* On program start, environ points to initial environment.
386 * putenv adds new pointers into it, unsetenv removes them.
387 * Neither of these (de)allocates the strings.
388 * setenv allocates new strings in malloc space and does putenv,
389 * and thus setenv is unusable (leaky) for shell's purposes */
390 #define setenv(...) setenv_is_leaky_dont_use()
392 struct variable *next;
393 char *varstr; /* points to "name=" portion */
394 int max_len; /* if > 0, name is part of initial env; else name is malloced */
395 smallint flg_export; /* putenv should be done on this var */
396 smallint flg_read_only;
404 #if ENABLE_HUSH_FUNCTIONS
406 struct function *next;
408 struct command *parent_cmd;
411 char *body_as_string;
417 /* "Globals" within this file */
418 /* Sorted roughly by size (smaller offsets == smaller code) */
420 #if ENABLE_HUSH_INTERACTIVE
421 /* 'interactive_fd' is a fd# open to ctty, if we have one
422 * _AND_ if we decided to act interactively */
426 #define G_interactive_fd (G.interactive_fd)
428 #define G_interactive_fd 0
430 #if ENABLE_FEATURE_EDITING
431 line_input_t *line_input_state;
437 pid_t saved_tty_pgrp;
439 struct pipe *job_list;
440 struct pipe *toplevel_list;
442 smallint flag_SIGINT;
443 #if ENABLE_HUSH_LOOPS
444 smallint flag_break_continue;
446 #if ENABLE_HUSH_FUNCTIONS
447 /* 0: outside of a function (or sourced file)
448 * -1: inside of a function, ok to use return builtin
449 * 1: return is invoked, skip all till end of func.
451 smallint flag_return_in_progress;
454 smallint exiting; /* used to prevent EXIT trap recursion */
455 /* These four support $?, $#, and $1 */
456 smalluint last_exitcode;
457 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
458 smalluint global_args_malloced;
459 /* how many non-NULL argv's we have. NB: $# + 1 */
463 char *argv0_for_re_execing;
465 #if ENABLE_HUSH_LOOPS
466 unsigned depth_break_continue;
467 unsigned depth_of_loop;
471 struct variable *top_var; /* = &G.shell_ver (set in main()) */
472 struct variable shell_ver;
473 #if ENABLE_HUSH_FUNCTIONS
474 struct function *top_func;
476 /* Signal and trap handling */
477 // unsigned count_SIGCHLD;
478 // unsigned handled_SIGCHLD;
479 /* which signals have non-DFL handler (even with no traps set)? */
480 unsigned non_DFL_mask;
481 char **traps; /* char *traps[NSIG] */
482 sigset_t blocked_set;
483 sigset_t inherited_set;
485 unsigned long memleak_value;
488 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
490 #define G (*ptr_to_globals)
491 /* Not #defining name to G.name - this quickly gets unwieldy
492 * (too many defines). Also, I actually prefer to see when a variable
493 * is global, thus "G." prefix is a useful hint */
494 #define INIT_G() do { \
495 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
499 /* Function prototypes for builtins */
500 static int builtin_cd(char **argv);
501 static int builtin_echo(char **argv);
502 static int builtin_eval(char **argv);
503 static int builtin_exec(char **argv);
504 static int builtin_exit(char **argv);
505 static int builtin_export(char **argv);
507 static int builtin_fg_bg(char **argv);
508 static int builtin_jobs(char **argv);
511 static int builtin_help(char **argv);
514 static int builtin_memleak(char **argv);
516 static int builtin_pwd(char **argv);
517 static int builtin_read(char **argv);
518 static int builtin_set(char **argv);
519 static int builtin_shift(char **argv);
520 static int builtin_source(char **argv);
521 static int builtin_test(char **argv);
522 static int builtin_trap(char **argv);
523 static int builtin_true(char **argv);
524 static int builtin_umask(char **argv);
525 static int builtin_unset(char **argv);
526 static int builtin_wait(char **argv);
527 #if ENABLE_HUSH_LOOPS
528 static int builtin_break(char **argv);
529 static int builtin_continue(char **argv);
531 #if ENABLE_HUSH_FUNCTIONS
532 static int builtin_return(char **argv);
535 /* Table of built-in functions. They can be forked or not, depending on
536 * context: within pipes, they fork. As simple commands, they do not.
537 * When used in non-forking context, they can change global variables
538 * in the parent shell process. If forked, of course they cannot.
539 * For example, 'unset foo | whatever' will parse and run, but foo will
540 * still be set at the end. */
541 struct built_in_command {
543 int (*function)(char **argv);
546 #define BLTIN(cmd, func, help) { cmd, func, help }
548 #define BLTIN(cmd, func, help) { cmd, func }
552 /* For now, echo and test are unconditionally enabled.
553 * Maybe make it configurable? */
554 static const struct built_in_command bltins[] = {
555 BLTIN("." , builtin_source , "Run commands in a file"),
556 BLTIN(":" , builtin_true , "No-op"),
557 BLTIN("[" , builtin_test , "Test condition"),
559 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
561 #if ENABLE_HUSH_LOOPS
562 BLTIN("break" , builtin_break , "Exit from a loop"),
564 BLTIN("cd" , builtin_cd , "Change directory"),
565 #if ENABLE_HUSH_LOOPS
566 BLTIN("continue", builtin_continue, "Start new loop iteration"),
568 BLTIN("echo" , builtin_echo , "Write to stdout"),
569 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
570 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
571 BLTIN("exit" , builtin_exit , "Exit"),
572 BLTIN("export" , builtin_export , "Set environment variable"),
574 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
577 BLTIN("help" , builtin_help , "List shell built-in commands"),
580 BLTIN("jobs" , builtin_jobs , "List active jobs"),
583 BLTIN("memleak" , builtin_memleak , "Debug tool"),
585 BLTIN("pwd" , builtin_pwd , "Print current directory"),
586 BLTIN("read" , builtin_read , "Input environment variable"),
587 #if ENABLE_HUSH_FUNCTIONS
588 BLTIN("return" , builtin_return , "Return from a function"),
590 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
591 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
592 BLTIN("test" , builtin_test , "Test condition"),
593 BLTIN("trap" , builtin_trap , "Trap signals"),
594 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
595 BLTIN("umask" , builtin_umask , "Set file creation mask"),
596 BLTIN("unset" , builtin_unset , "Unset environment variable"),
597 BLTIN("wait" , builtin_wait , "Wait for process"),
604 /* prevent disasters with G.debug_indent < 0 */
605 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
606 # define debug_enter() (G.debug_indent++)
607 # define debug_leave() (G.debug_indent--)
609 # define indent() ((void)0)
610 # define debug_enter() ((void)0)
611 # define debug_leave() ((void)0)
615 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
618 #ifndef debug_printf_parse
619 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
622 #ifndef debug_printf_exec
623 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
626 #ifndef debug_printf_env
627 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
630 #ifndef debug_printf_jobs
631 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
632 # define DEBUG_JOBS 1
634 # define DEBUG_JOBS 0
637 #ifndef debug_printf_expand
638 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
639 # define DEBUG_EXPAND 1
641 # define DEBUG_EXPAND 0
644 #ifndef debug_printf_glob
645 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
646 # define DEBUG_GLOB 1
648 # define DEBUG_GLOB 0
651 #ifndef debug_printf_list
652 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
655 #ifndef debug_printf_subst
656 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
659 #ifndef debug_printf_clean
660 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
661 # define DEBUG_CLEAN 1
663 # define DEBUG_CLEAN 0
667 static void debug_print_strings(const char *prefix, char **vv)
670 fprintf(stderr, "%s:\n", prefix);
672 fprintf(stderr, " '%s'\n", *vv++);
675 #define debug_print_strings(prefix, vv) ((void)0)
679 /* Leak hunting. Use hush_leaktool.sh for post-processing.
682 static void *xxmalloc(int lineno, size_t size)
684 void *ptr = xmalloc((size + 0xff) & ~0xff);
685 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
688 static void *xxrealloc(int lineno, void *ptr, size_t size)
690 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
691 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
694 static char *xxstrdup(int lineno, const char *str)
696 char *ptr = xstrdup(str);
697 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
700 static void xxfree(void *ptr)
702 fdprintf(2, "free %p\n", ptr);
705 #define xmalloc(s) xxmalloc(__LINE__, s)
706 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
707 #define xstrdup(s) xxstrdup(__LINE__, s)
708 #define free(p) xxfree(p)
712 /* Syntax and runtime errors. They always abort scripts.
713 * In interactive use they usually discard unparsed and/or unexecuted commands
714 * and return to the prompt.
715 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
718 # define die_if_script(lineno, fmt...) die_if_script(fmt)
719 # define syntax_error(lineno, msg) syntax_error(msg)
720 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
721 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
722 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
723 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
726 static void die_if_script(unsigned lineno, const char *fmt, ...)
731 bb_error_msg("hush.c:%u", lineno);
734 bb_verror_msg(fmt, p, NULL);
736 if (!G_interactive_fd)
740 static void syntax_error(unsigned lineno, const char *msg)
743 die_if_script(lineno, "syntax error: %s", msg);
745 die_if_script(lineno, "syntax error", NULL);
748 static void syntax_error_at(unsigned lineno, const char *msg)
750 die_if_script(lineno, "syntax error at '%s'", msg);
753 /* It so happens that all such cases are totally fatal
754 * even if shell is interactive: EOF while looking for closing
755 * delimiter. There is nowhere to read stuff from after that,
756 * it's EOF! The only choice is to terminate.
758 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
759 static void syntax_error_unterm_ch(unsigned lineno, char ch)
764 die_if_script(lineno, "syntax error: unterminated %s", msg);
768 static void syntax_error_unterm_str(unsigned lineno, const char *s)
770 die_if_script(lineno, "syntax error: unterminated %s", s);
773 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
778 die_if_script(lineno, "syntax error: unexpected %s", msg);
782 # undef die_if_script
784 # undef syntax_error_at
785 # undef syntax_error_unterm_ch
786 # undef syntax_error_unterm_str
787 # undef syntax_error_unexpected_ch
789 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
790 # define syntax_error(msg) syntax_error(__LINE__, msg)
791 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
792 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
793 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
794 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
800 static int glob_needed(const char *s)
805 if (*s == '*' || *s == '[' || *s == '?')
812 static int is_well_formed_var_name(const char *s, char terminator)
814 if (!s || !(isalpha(*s) || *s == '_'))
817 while (isalnum(*s) || *s == '_')
819 return *s == terminator;
822 /* Replace each \x with x in place, return ptr past NUL. */
823 static char *unbackslash(char *src)
829 if ((*dst++ = *src++) == '\0')
835 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
856 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
857 v[count1 + count2] = NULL;
860 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
864 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
866 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
867 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
870 #define add_strings_to_strings(strings, add, need_to_dup) \
871 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
874 static char **add_string_to_strings(char **strings, char *add)
879 return add_strings_to_strings(strings, v, /*dup:*/ 0);
882 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
884 char **ptr = add_string_to_strings(strings, add);
885 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
888 #define add_string_to_strings(strings, add) \
889 xx_add_string_to_strings(__LINE__, strings, add)
892 static void putenv_all(char **strings)
897 debug_printf_env("putenv '%s'\n", *strings);
902 static char **putenv_all_and_save_old(char **strings)
912 eq = strchr(*strings, '=');
915 v = getenv(*strings);
918 /* v points to VAL in VAR=VAL, go back to VAR */
919 v -= (eq - *strings) + 1;
920 old = add_string_to_strings(old, v);
929 static void free_strings_and_unsetenv(char **strings, int unset)
939 debug_printf_env("unsetenv '%s'\n", *v);
947 static void free_strings(char **strings)
949 free_strings_and_unsetenv(strings, 0);
953 /* Helpers for setting new $n and restoring them back
955 typedef struct save_arg_t {
959 smallint sv_g_malloced;
962 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
966 sv->sv_argv0 = argv[0];
967 sv->sv_g_argv = G.global_argv;
968 sv->sv_g_argc = G.global_argc;
969 sv->sv_g_malloced = G.global_args_malloced;
971 argv[0] = G.global_argv[0]; /* retain $0 */
972 G.global_argv = argv;
973 G.global_args_malloced = 0;
981 static void restore_G_args(save_arg_t *sv, char **argv)
985 if (G.global_args_malloced) {
986 /* someone ran "set -- arg1 arg2 ...", undo */
988 while (*++pp) /* note: does not free $0 */
992 argv[0] = sv->sv_argv0;
993 G.global_argv = sv->sv_g_argv;
994 G.global_argc = sv->sv_g_argc;
995 G.global_args_malloced = sv->sv_g_malloced;
999 /* Basic theory of signal handling in shell
1000 * ========================================
1001 * This does not describe what hush does, rather, it is current understanding
1002 * what it _should_ do. If it doesn't, it's a bug.
1003 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1005 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1006 * is finished or backgrounded. It is the same in interactive and
1007 * non-interactive shells, and is the same regardless of whether
1008 * a user trap handler is installed or a shell special one is in effect.
1009 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1010 * backgrounds (i.e. stops) or kills all members of currently running
1013 * Wait builtin in interruptible by signals for which user trap is set
1014 * or by SIGINT in interactive shell.
1016 * Trap handlers will execute even within trap handlers. (right?)
1018 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1020 * If job control is off, backgrounded commands ("cmd &")
1021 * have SIGINT, SIGQUIT set to SIG_IGN.
1023 * Commands run in command substitution ("`cmd`")
1024 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1026 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
1027 * by the shell from its parent.
1029 * Siganls which differ from SIG_DFL action
1030 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1033 * SIGTERM (interactive): ignore
1034 * SIGHUP (interactive):
1035 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1036 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1037 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1038 * that all pipe members are stopped. Try this in bash:
1039 * while :; do :; done - ^Z does not background it
1040 * (while :; do :; done) - ^Z backgrounds it
1041 * SIGINT (interactive): wait for last pipe, ignore the rest
1042 * of the command line, show prompt. NB: ^C does not send SIGINT
1043 * to interactive shell while shell is waiting for a pipe,
1044 * since shell is bg'ed (is not in foreground process group).
1045 * Example 1: this waits 5 sec, but does not execute ls:
1046 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1047 * Example 2: this does not wait and does not execute ls:
1048 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1049 * Example 3: this does not wait 5 sec, but executes ls:
1050 * "sleep 5; ls -l" + press ^C
1052 * (What happens to signals which are IGN on shell start?)
1053 * (What happens with signal mask on shell start?)
1055 * Implementation in hush
1056 * ======================
1057 * We use in-kernel pending signal mask to determine which signals were sent.
1058 * We block all signals which we don't want to take action immediately,
1059 * i.e. we block all signals which need to have special handling as described
1060 * above, and all signals which have traps set.
1061 * After each pipe execution, we extract any pending signals via sigtimedwait()
1064 * unsigned non_DFL_mask: a mask of such "special" signals
1065 * sigset_t blocked_set: current blocked signal set
1068 * clear bit in blocked_set unless it is also in non_DFL_mask
1069 * "trap 'cmd' SIGxxx":
1070 * set bit in blocked_set (even if 'cmd' is '')
1071 * after [v]fork, if we plan to be a shell:
1072 * unblock signals with special interactive handling
1073 * (child shell is not interactive),
1074 * unset all traps (note: regardless of child shell's type - {}, (), etc)
1075 * after [v]fork, if we plan to exec:
1076 * POSIX says pending signal mask is cleared in child - no need to clear it.
1077 * Restore blocked signal set to one inherited by shell just prior to exec.
1079 * Note: as a result, we do not use signal handlers much. The only uses
1080 * are to count SIGCHLDs [disabled - bug somewhere, + bloat]
1081 * and to restore tty pgrp on signal-induced exit.
1084 SPECIAL_INTERACTIVE_SIGS = 0
1086 | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
1093 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1095 // G.count_SIGCHLD++;
1100 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1101 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1102 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1103 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1105 /* Restores tty foreground process group, and exits.
1106 * May be called as signal handler for fatal signal
1107 * (will resend signal to itself, producing correct exit state)
1108 * or called directly with -EXITCODE.
1109 * We also call it if xfunc is exiting. */
1110 static void sigexit(int sig) NORETURN;
1111 static void sigexit(int sig)
1113 /* Disable all signals: job control, SIGPIPE, etc. */
1114 sigprocmask_allsigs(SIG_BLOCK);
1116 /* Careful: we can end up here after [v]fork. Do not restore
1117 * tty pgrp then, only top-level shell process does that */
1118 if (G_interactive_fd && getpid() == G.root_pid)
1119 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1121 /* Not a signal, just exit */
1125 kill_myself_with_sig(sig); /* does not return */
1129 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1130 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1134 /* Restores tty foreground process group, and exits. */
1135 static void hush_exit(int exitcode) NORETURN;
1136 static void hush_exit(int exitcode)
1138 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1139 /* Prevent recursion:
1140 * trap "echo Hi; exit" EXIT; exit
1142 char *argv[] = { NULL, G.traps[0], NULL };
1150 fflush(NULL); /* flush all streams */
1151 sigexit(- (exitcode & 0xff));
1157 static int check_and_run_traps(int sig)
1159 static const struct timespec zero_timespec = { 0, 0 };
1160 smalluint save_rcode;
1166 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1171 if (G.traps && G.traps[sig]) {
1172 if (G.traps[sig][0]) {
1173 /* We have user-defined handler */
1174 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1175 save_rcode = G.last_exitcode;
1178 G.last_exitcode = save_rcode;
1179 } /* else: "" trap, ignoring signal */
1182 /* not a trap: special action */
1185 // G.count_SIGCHLD++;
1188 /* Builtin was ^C'ed, make it look prettier: */
1195 /* bash is observed to signal whole process groups,
1196 * not individual processes */
1197 for (job = G.job_list; job; job = job->next) {
1200 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1201 if (kill(- job->pgrp, SIGHUP) == 0)
1202 kill(- job->pgrp, SIGCONT);
1207 default: /* ignored: */
1208 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1216 static const char *set_cwd(void)
1218 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1219 * we must not try to free(bb_msg_unknown) */
1220 if (G.cwd == bb_msg_unknown)
1222 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1224 G.cwd = bb_msg_unknown;
1229 /* Get/check local shell variables */
1230 static struct variable *get_local_var(const char *name)
1232 struct variable *cur;
1238 for (cur = G.top_var; cur; cur = cur->next) {
1239 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1245 static const char *get_local_var_value(const char *src)
1247 struct variable *var = get_local_var(src);
1249 return strchr(var->varstr, '=') + 1;
1253 /* str holds "NAME=VAL" and is expected to be malloced.
1254 * We take ownership of it.
1258 * -1: if NAME is set, leave export status alone
1259 * if NAME is not set, do not export
1260 * flg_read_only is set only when we handle -R var=val
1263 #define set_local_var(str, flg_export, flg_read_only) \
1264 set_local_var(str, flg_export)
1266 static int set_local_var(char *str, int flg_export, int flg_read_only)
1268 struct variable *cur;
1272 value = strchr(str, '=');
1273 if (!value) { /* not expected to ever happen? */
1278 name_len = value - str + 1; /* including '=' */
1279 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1281 if (strncmp(cur->varstr, str, name_len) != 0) {
1283 /* Bail out. Note that now cur points
1284 * to last var in linked list */
1290 /* We found an existing var with this name */
1292 if (cur->flg_read_only) {
1296 bb_error_msg("%s: readonly variable", str);
1300 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1301 unsetenv(str); /* just in case */
1303 if (strcmp(cur->varstr, str) == 0) {
1308 if (cur->max_len >= strlen(str)) {
1309 /* This one is from startup env, reuse space */
1310 strcpy(cur->varstr, str);
1313 /* max_len == 0 signifies "malloced" var, which we can
1314 * (and has to) free */
1318 goto set_str_and_exp;
1321 /* Not found - create next variable struct */
1322 cur->next = xzalloc(sizeof(*cur));
1328 cur->flg_read_only = flg_read_only;
1331 if (flg_export == 1)
1332 cur->flg_export = 1;
1333 if (cur->flg_export) {
1334 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1335 return putenv(cur->varstr);
1340 static int unset_local_var(const char *name)
1342 struct variable *cur;
1343 struct variable *prev = prev; /* for gcc */
1347 return EXIT_SUCCESS;
1348 name_len = strlen(name);
1351 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1352 if (cur->flg_read_only) {
1353 bb_error_msg("%s: readonly variable", name);
1354 return EXIT_FAILURE;
1356 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1357 * is ro, and we cannot reach this code on the 1st pass */
1358 prev->next = cur->next;
1359 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1360 bb_unsetenv(cur->varstr);
1364 return EXIT_SUCCESS;
1369 return EXIT_SUCCESS;
1372 #if ENABLE_SH_MATH_SUPPORT
1373 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1374 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1375 static char *endofname(const char *name)
1383 if (!is_in_name(*p))
1389 static void arith_set_local_var(const char *name, const char *val, int flags)
1391 /* arith code doesnt malloc space, so do it for it */
1392 char *var = xasprintf("%s=%s", name, val);
1393 set_local_var(var, flags, 0);
1401 static int static_get(struct in_str *i)
1410 static int static_peek(struct in_str *i)
1415 #if ENABLE_HUSH_INTERACTIVE
1417 static void cmdedit_set_initial_prompt(void)
1419 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1420 G.PS1 = getenv("PS1");
1427 static const char* setup_prompt_string(int promptmode)
1429 const char *prompt_str;
1430 debug_printf("setup_prompt_string %d ", promptmode);
1431 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1432 /* Set up the prompt */
1433 if (promptmode == 0) { /* PS1 */
1435 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1440 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1441 debug_printf("result '%s'\n", prompt_str);
1445 static void get_user_input(struct in_str *i)
1448 const char *prompt_str;
1450 prompt_str = setup_prompt_string(i->promptmode);
1451 #if ENABLE_FEATURE_EDITING
1452 /* Enable command line editing only while a command line
1453 * is actually being read */
1456 /* buglet: SIGINT will not make new prompt to appear _at once_,
1457 * only after <Enter>. (^C will work) */
1458 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1459 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1460 check_and_run_traps(0);
1461 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1462 i->eof_flag = (r < 0);
1463 if (i->eof_flag) { /* EOF/error detected */
1464 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1465 G.user_input_buf[1] = '\0';
1470 fputs(prompt_str, stdout);
1472 G.user_input_buf[0] = r = fgetc(i->file);
1473 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1474 //do we need check_and_run_traps(0)? (maybe only if stdin)
1475 } while (G.flag_SIGINT);
1476 i->eof_flag = (r == EOF);
1478 i->p = G.user_input_buf;
1481 #endif /* INTERACTIVE */
1483 /* This is the magic location that prints prompts
1484 * and gets data back from the user */
1485 static int file_get(struct in_str *i)
1489 /* If there is data waiting, eat it up */
1490 if (i->p && *i->p) {
1491 #if ENABLE_HUSH_INTERACTIVE
1495 if (i->eof_flag && !*i->p)
1497 /* note: ch is never NUL */
1499 /* need to double check i->file because we might be doing something
1500 * more complicated by now, like sourcing or substituting. */
1501 #if ENABLE_HUSH_INTERACTIVE
1502 if (G_interactive_fd && i->promptme && i->file == stdin) {
1505 } while (!*i->p); /* need non-empty line */
1506 i->promptmode = 1; /* PS2 */
1511 do ch = fgetc(i->file); while (ch == '\0');
1513 debug_printf("file_get: got '%c' %d\n", ch, ch);
1514 #if ENABLE_HUSH_INTERACTIVE
1521 /* All callers guarantee this routine will never
1522 * be used right after a newline, so prompting is not needed.
1524 static int file_peek(struct in_str *i)
1527 if (i->p && *i->p) {
1528 if (i->eof_flag && !i->p[1])
1531 /* note: ch is never NUL */
1533 do ch = fgetc(i->file); while (ch == '\0');
1534 i->eof_flag = (ch == EOF);
1535 i->peek_buf[0] = ch;
1536 i->peek_buf[1] = '\0';
1538 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1542 static void setup_file_in_str(struct in_str *i, FILE *f)
1544 i->peek = file_peek;
1546 #if ENABLE_HUSH_INTERACTIVE
1548 i->promptmode = 0; /* PS1 */
1554 static void setup_string_in_str(struct in_str *i, const char *s)
1556 i->peek = static_peek;
1557 i->get = static_get;
1558 #if ENABLE_HUSH_INTERACTIVE
1560 i->promptmode = 0; /* PS1 */
1570 #define B_CHUNK (32 * sizeof(char*))
1572 static void o_reset_to_empty_unquoted(o_string *o)
1580 static void o_free(o_string *o)
1583 memset(o, 0, sizeof(*o));
1586 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1591 static void o_grow_by(o_string *o, int len)
1593 if (o->length + len > o->maxlen) {
1594 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1595 o->data = xrealloc(o->data, 1 + o->maxlen);
1599 static void o_addchr(o_string *o, int ch)
1601 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1603 o->data[o->length] = ch;
1605 o->data[o->length] = '\0';
1608 static void o_addblock(o_string *o, const char *str, int len)
1611 memcpy(&o->data[o->length], str, len);
1613 o->data[o->length] = '\0';
1617 static void o_addstr(o_string *o, const char *str)
1619 o_addblock(o, str, strlen(str));
1621 static void nommu_addchr(o_string *o, int ch)
1627 #define nommu_addchr(o, str) ((void)0)
1630 static void o_addstr_with_NUL(o_string *o, const char *str)
1632 o_addblock(o, str, strlen(str) + 1);
1635 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1640 && (*str != '*' && *str != '?' && *str != '[')
1648 /* My analysis of quoting semantics tells me that state information
1649 * is associated with a destination, not a source.
1651 static void o_addqchr(o_string *o, int ch)
1654 char *found = strchr("*?[\\", ch);
1659 o->data[o->length] = '\\';
1662 o->data[o->length] = ch;
1664 o->data[o->length] = '\0';
1667 static void o_addQchr(o_string *o, int ch)
1670 if (o->o_escape && strchr("*?[\\", ch)) {
1672 o->data[o->length] = '\\';
1676 o->data[o->length] = ch;
1678 o->data[o->length] = '\0';
1681 static void o_addQstr(o_string *o, const char *str, int len)
1684 o_addblock(o, str, len);
1690 int ordinary_cnt = strcspn(str, "*?[\\");
1691 if (ordinary_cnt > len) /* paranoia */
1693 o_addblock(o, str, ordinary_cnt);
1694 if (ordinary_cnt == len)
1696 str += ordinary_cnt;
1697 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1701 if (ch) { /* it is necessarily one of "*?[\\" */
1703 o->data[o->length] = '\\';
1707 o->data[o->length] = ch;
1709 o->data[o->length] = '\0';
1713 /* A special kind of o_string for $VAR and `cmd` expansion.
1714 * It contains char* list[] at the beginning, which is grown in 16 element
1715 * increments. Actual string data starts at the next multiple of 16 * (char*).
1716 * list[i] contains an INDEX (int!) into this string data.
1717 * It means that if list[] needs to grow, data needs to be moved higher up
1718 * but list[i]'s need not be modified.
1719 * NB: remembering how many list[i]'s you have there is crucial.
1720 * o_finalize_list() operation post-processes this structure - calculates
1721 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1723 #if DEBUG_EXPAND || DEBUG_GLOB
1724 static void debug_print_list(const char *prefix, o_string *o, int n)
1726 char **list = (char**)o->data;
1727 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1731 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1732 prefix, list, n, string_start, o->length, o->maxlen);
1735 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1736 o->data + (int)list[i] + string_start,
1737 o->data + (int)list[i] + string_start);
1741 const char *p = o->data + (int)list[n - 1] + string_start;
1743 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1747 #define debug_print_list(prefix, o, n) ((void)0)
1750 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1751 * in list[n] so that it points past last stored byte so far.
1752 * It returns n+1. */
1753 static int o_save_ptr_helper(o_string *o, int n)
1755 char **list = (char**)o->data;
1759 if (!o->has_empty_slot) {
1760 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1761 string_len = o->length - string_start;
1762 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1763 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1764 /* list[n] points to string_start, make space for 16 more pointers */
1765 o->maxlen += 0x10 * sizeof(list[0]);
1766 o->data = xrealloc(o->data, o->maxlen + 1);
1767 list = (char**)o->data;
1768 memmove(list + n + 0x10, list + n, string_len);
1769 o->length += 0x10 * sizeof(list[0]);
1771 debug_printf_list("list[%d]=%d string_start=%d\n",
1772 n, string_len, string_start);
1775 /* We have empty slot at list[n], reuse without growth */
1776 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1777 string_len = o->length - string_start;
1778 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1779 n, string_len, string_start);
1780 o->has_empty_slot = 0;
1782 list[n] = (char*)(ptrdiff_t)string_len;
1786 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1787 static int o_get_last_ptr(o_string *o, int n)
1789 char **list = (char**)o->data;
1790 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1792 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1795 /* o_glob performs globbing on last list[], saving each result
1796 * as a new list[]. */
1797 static int o_glob(o_string *o, int n)
1803 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1805 return o_save_ptr_helper(o, n);
1806 pattern = o->data + o_get_last_ptr(o, n);
1807 debug_printf_glob("glob pattern '%s'\n", pattern);
1808 if (!glob_needed(pattern)) {
1810 o->length = unbackslash(pattern) - o->data;
1811 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1812 return o_save_ptr_helper(o, n);
1815 memset(&globdata, 0, sizeof(globdata));
1816 gr = glob(pattern, 0, NULL, &globdata);
1817 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1818 if (gr == GLOB_NOSPACE)
1819 bb_error_msg_and_die("out of memory during glob");
1820 if (gr == GLOB_NOMATCH) {
1821 globfree(&globdata);
1824 if (gr != 0) { /* GLOB_ABORTED ? */
1825 /* TODO: testcase for bad glob pattern behavior */
1826 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1828 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1829 char **argv = globdata.gl_pathv;
1830 o->length = pattern - o->data; /* "forget" pattern */
1832 o_addstr_with_NUL(o, *argv);
1833 n = o_save_ptr_helper(o, n);
1839 globfree(&globdata);
1841 debug_print_list("o_glob returning", o, n);
1845 /* If o->o_glob == 1, glob the string so far remembered.
1846 * Otherwise, just finish current list[] and start new */
1847 static int o_save_ptr(o_string *o, int n)
1849 if (o->o_glob) { /* if globbing is requested */
1850 /* If o->has_empty_slot, list[n] was already globbed
1851 * (if it was requested back then when it was filled)
1852 * so don't do that again! */
1853 if (!o->has_empty_slot)
1854 return o_glob(o, n); /* o_save_ptr_helper is inside */
1856 return o_save_ptr_helper(o, n);
1859 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1860 static char **o_finalize_list(o_string *o, int n)
1865 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1867 debug_print_list("finalized", o, n);
1868 debug_printf_expand("finalized n:%d\n", n);
1869 list = (char**)o->data;
1870 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1874 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1880 /* Expansion can recurse */
1881 #if ENABLE_HUSH_TICK
1882 static int process_command_subs(o_string *dest, const char *s);
1884 static char *expand_string_to_string(const char *str);
1886 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1887 parse_stream_dquoted(dest, input, dquote_end)
1889 static int parse_stream_dquoted(o_string *as_string,
1891 struct in_str *input,
1894 /* expand_strvec_to_strvec() takes a list of strings, expands
1895 * all variable references within and returns a pointer to
1896 * a list of expanded strings, possibly with larger number
1897 * of strings. (Think VAR="a b"; echo $VAR).
1898 * This new list is allocated as a single malloc block.
1899 * NULL-terminated list of char* pointers is at the beginning of it,
1900 * followed by strings themself.
1901 * Caller can deallocate entire list by single free(list). */
1903 /* Store given string, finalizing the word and starting new one whenever
1904 * we encounter IFS char(s). This is used for expanding variable values.
1905 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1906 static int expand_on_ifs(o_string *output, int n, const char *str)
1909 int word_len = strcspn(str, G.ifs);
1911 if (output->o_escape || !output->o_glob)
1912 o_addQstr(output, str, word_len);
1913 else /* protect backslashes against globbing up :) */
1914 o_addblock_duplicate_backslash(output, str, word_len);
1917 if (!*str) /* EOL - do not finalize word */
1919 o_addchr(output, '\0');
1920 debug_print_list("expand_on_ifs", output, n);
1921 n = o_save_ptr(output, n);
1922 str += strspn(str, G.ifs); /* skip ifs chars */
1924 debug_print_list("expand_on_ifs[1]", output, n);
1928 /* Helper to expand $((...)) and heredoc body. These act as if
1929 * they are in double quotes, with the exception that they are not :).
1930 * Just the rules are similar: "expand only $var and `cmd`"
1932 * Returns malloced string.
1933 * As an optimization, we return NULL if expansion is not needed.
1935 static char *expand_pseudo_dquoted(const char *str)
1938 struct in_str input;
1939 o_string dest = NULL_O_STRING;
1941 if (strchr(str, '$') == NULL
1942 #if ENABLE_HUSH_TICK
1943 && strchr(str, '`') == NULL
1949 /* We need to expand. Example:
1950 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1952 setup_string_in_str(&input, str);
1953 parse_stream_dquoted(NULL, &dest, &input, EOF);
1954 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1955 exp_str = expand_string_to_string(dest.data);
1956 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1957 o_free_unsafe(&dest);
1961 /* Expand all variable references in given string, adding words to list[]
1962 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1963 * to be filled). This routine is extremely tricky: has to deal with
1964 * variables/parameters with whitespace, $* and $@, and constructs like
1965 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1966 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1968 /* or_mask is either 0 (normal case) or 0x80
1969 * (expansion of right-hand side of assignment == 1-element expand.
1970 * It will also do no globbing, and thus we must not backslash-quote!) */
1972 char first_ch, ored_ch;
1980 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1981 debug_print_list("expand_vars_to_list", output, n);
1982 n = o_save_ptr(output, n);
1983 debug_print_list("expand_vars_to_list[0]", output, n);
1985 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1986 #if ENABLE_HUSH_TICK
1987 o_string subst_result = NULL_O_STRING;
1989 #if ENABLE_SH_MATH_SUPPORT
1990 char arith_buf[sizeof(arith_t)*3 + 2];
1992 o_addblock(output, arg, p - arg);
1993 debug_print_list("expand_vars_to_list[1]", output, n);
1995 p = strchr(p, SPECIAL_VAR_SYMBOL);
1997 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1998 /* "$@" is special. Even if quoted, it can still
1999 * expand to nothing (not even an empty string) */
2000 if ((first_ch & 0x7f) != '@')
2001 ored_ch |= first_ch;
2004 switch (first_ch & 0x7f) {
2005 /* Highest bit in first_ch indicates that var is double-quoted */
2007 val = utoa(G.root_pid);
2009 case '!': /* bg pid */
2010 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2012 case '?': /* exitcode */
2013 val = utoa(G.last_exitcode);
2015 case '#': /* argc */
2016 if (arg[1] != SPECIAL_VAR_SYMBOL)
2017 /* actually, it's a ${#var} */
2019 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2024 if (!G.global_argv[i])
2026 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2027 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2028 smallint sv = output->o_escape;
2029 /* unquoted var's contents should be globbed, so don't escape */
2030 output->o_escape = 0;
2031 while (G.global_argv[i]) {
2032 n = expand_on_ifs(output, n, G.global_argv[i]);
2033 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2034 if (G.global_argv[i++][0] && G.global_argv[i]) {
2035 /* this argv[] is not empty and not last:
2036 * put terminating NUL, start new word */
2037 o_addchr(output, '\0');
2038 debug_print_list("expand_vars_to_list[2]", output, n);
2039 n = o_save_ptr(output, n);
2040 debug_print_list("expand_vars_to_list[3]", output, n);
2043 output->o_escape = sv;
2045 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2046 * and in this case should treat it like '$*' - see 'else...' below */
2047 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2049 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2050 if (++i >= G.global_argc)
2052 o_addchr(output, '\0');
2053 debug_print_list("expand_vars_to_list[4]", output, n);
2054 n = o_save_ptr(output, n);
2056 } else { /* quoted $*: add as one word */
2058 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2059 if (!G.global_argv[++i])
2062 o_addchr(output, G.ifs[0]);
2066 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2067 /* "Empty variable", used to make "" etc to not disappear */
2071 #if ENABLE_HUSH_TICK
2072 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2075 /* Can't just stuff it into output o_string,
2076 * expanded result may need to be globbed
2077 * and $IFS-splitted */
2078 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2079 process_command_subs(&subst_result, arg);
2080 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2081 val = subst_result.data;
2084 #if ENABLE_SH_MATH_SUPPORT
2085 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2086 arith_eval_hooks_t hooks;
2091 arg++; /* skip '+' */
2092 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2093 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2095 exp_str = expand_pseudo_dquoted(arg);
2096 hooks.lookupvar = get_local_var_value;
2097 hooks.setvar = arith_set_local_var;
2098 hooks.endofname = endofname;
2099 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2103 const char *msg = "error in arithmetic";
2106 msg = "exponent less than 0";
2109 msg = "divide by 0";
2112 msg = "expression recursion loop detected";
2117 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2118 sprintf(arith_buf, arith_t_fmt, res);
2123 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2125 bool exp_len = false;
2126 bool exp_null = false;
2128 char exp_save = exp_save; /* for compiler */
2129 char exp_op = exp_op; /* for compiler */
2130 char *exp_word = exp_word; /* for compiler */
2134 arg[0] = first_ch & 0x7f;
2136 /* prepare for expansions */
2137 if (var[0] == '#') {
2138 /* handle length expansion ${#var} */
2142 /* maybe handle parameter expansion */
2143 exp_off = strcspn(var, ":-=+?%#");
2147 exp_save = var[exp_off];
2148 exp_null = exp_save == ':';
2149 exp_word = var + exp_off;
2152 exp_op = *exp_word++;
2153 var[exp_off] = '\0';
2157 /* lookup the variable in question */
2158 if (isdigit(var[0])) {
2159 /* handle_dollar() should have vetted var for us */
2161 if (i < G.global_argc)
2162 val = G.global_argv[i];
2163 /* else val remains NULL: $N with too big N */
2165 val = get_local_var_value(var);
2167 /* handle any expansions */
2169 debug_printf_expand("expand: length of '%s' = ", val);
2170 val = utoa(val ? strlen(val) : 0);
2171 debug_printf_expand("%s\n", val);
2172 } else if (exp_off) {
2173 if (exp_op == '%' || exp_op == '#') {
2175 /* we need to do a pattern match */
2178 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2179 if (exp_op == *exp_word) /* ## or %% */
2181 val = dyn_val = xstrdup(val);
2182 loc = scan(dyn_val, exp_word, zero);
2189 /* we need to do an expansion */
2190 int exp_test = (!val || (exp_null && !val[0]));
2192 exp_test = !exp_test;
2193 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2194 exp_null ? "true" : "false", exp_test);
2196 if (exp_op == '?') {
2197 //TODO: how interactive bash aborts expansion mid-command?
2198 /* ${var?[error_msg_if_unset]} */
2199 /* ${var:?[error_msg_if_unset_or_null]} */
2200 /* mimic bash message */
2201 die_if_script("%s: %s",
2203 exp_word[0] ? exp_word : "parameter null or not set"
2209 if (exp_op == '=') {
2210 /* ${var=[word]} or ${var:=[word]} */
2211 if (isdigit(var[0]) || var[0] == '#') {
2212 /* mimic bash message */
2213 die_if_script("$%s: cannot assign in this way", var);
2216 char *new_var = xasprintf("%s=%s", var, val);
2217 set_local_var(new_var, -1, 0);
2223 var[exp_off] = exp_save;
2227 #if ENABLE_HUSH_TICK
2230 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2231 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2233 /* unquoted var's contents should be globbed, so don't escape */
2234 smallint sv = output->o_escape;
2235 output->o_escape = 0;
2236 n = expand_on_ifs(output, n, val);
2238 output->o_escape = sv;
2240 } else { /* quoted $VAR, val will be appended below */
2241 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2244 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2246 o_addQstr(output, val, strlen(val));
2250 /* Do the check to avoid writing to a const string */
2251 if (*p != SPECIAL_VAR_SYMBOL)
2252 *p = SPECIAL_VAR_SYMBOL;
2254 #if ENABLE_HUSH_TICK
2255 o_free(&subst_result);
2258 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2261 debug_print_list("expand_vars_to_list[a]", output, n);
2262 /* this part is literal, and it was already pre-quoted
2263 * if needed (much earlier), do not use o_addQstr here! */
2264 o_addstr_with_NUL(output, arg);
2265 debug_print_list("expand_vars_to_list[b]", output, n);
2266 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2267 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2270 /* allow to reuse list[n] later without re-growth */
2271 output->has_empty_slot = 1;
2273 o_addchr(output, '\0');
2278 static char **expand_variables(char **argv, int or_mask)
2283 o_string output = NULL_O_STRING;
2285 if (or_mask & 0x100) {
2286 output.o_escape = 1; /* protect against globbing for "$var" */
2287 /* (unquoted $var will temporarily switch it off) */
2294 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2297 debug_print_list("expand_variables", &output, n);
2299 /* output.data (malloced in one block) gets returned in "list" */
2300 list = o_finalize_list(&output, n);
2301 debug_print_strings("expand_variables[1]", list);
2305 static char **expand_strvec_to_strvec(char **argv)
2307 return expand_variables(argv, 0x100);
2310 /* Used for expansion of right hand of assignments */
2311 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2313 static char *expand_string_to_string(const char *str)
2315 char *argv[2], **list;
2317 argv[0] = (char*)str;
2319 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2321 if (!list[0] || list[1])
2322 bb_error_msg_and_die("BUG in varexp2");
2323 /* actually, just move string 2*sizeof(char*) bytes back */
2324 overlapping_strcpy((char*)list, list[0]);
2325 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2329 /* Used for "eval" builtin */
2330 static char* expand_strvec_to_string(char **argv)
2334 list = expand_variables(argv, 0x80);
2335 /* Convert all NULs to spaces */
2340 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2341 bb_error_msg_and_die("BUG in varexp3");
2342 /* bash uses ' ' regardless of $IFS contents */
2347 overlapping_strcpy((char*)list, list[0]);
2348 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2352 static char **expand_assignments(char **argv, int count)
2356 /* Expand assignments into one string each */
2357 for (i = 0; i < count; i++) {
2358 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2366 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2368 static void reset_traps_to_defaults(void)
2370 /* This function is always called in a child shell
2371 * after fork (not vfork, NOMMU doesn't use this function).
2372 * Child shells are not interactive.
2373 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2374 * Testcase: (while :; do :; done) + ^Z should background.
2375 * Same goes for SIGTERM, SIGHUP, SIGINT.
2380 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2383 /* Stupid. It can be done with *single* &= op, but we can't use
2384 * the fact that G.blocked_set is implemented as a bitmask... */
2385 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2389 sigdelset(&G.blocked_set, sig);
2396 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2397 mask = G.non_DFL_mask;
2398 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2402 G.traps[sig] = NULL;
2403 /* There is no signal for 0 (EXIT) */
2406 /* There was a trap handler, we are removing it.
2407 * But if sig still has non-DFL handling,
2408 * we should not unblock it. */
2411 sigdelset(&G.blocked_set, sig);
2413 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2418 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2419 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2421 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2422 char *heredoc_argv[4];
2423 struct variable *cur;
2424 #if ENABLE_HUSH_FUNCTIONS
2425 struct function *funcp;
2430 if (!g_argv0) { /* heredoc */
2431 argv = heredoc_argv;
2432 argv[0] = (char *) G.argv0_for_re_execing;
2433 argv[1] = (char *) "-<";
2434 argv[2] = (char *) s;
2436 pp = &argv[3]; /* used as pointer to empty environment */
2440 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2441 , (unsigned) G.root_pid
2442 , (unsigned) G.last_bg_pid
2443 , (unsigned) G.last_exitcode
2444 USE_HUSH_LOOPS(, G.depth_of_loop)
2446 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2447 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2450 for (cur = G.top_var; cur; cur = cur->next) {
2451 if (!cur->flg_export || cur->flg_read_only)
2454 #if ENABLE_HUSH_FUNCTIONS
2455 for (funcp = G.top_func; funcp; funcp = funcp->next)
2461 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2462 *pp++ = (char *) G.argv0_for_re_execing;
2464 for (cur = G.top_var; cur; cur = cur->next) {
2465 if (cur->varstr == hush_version_str)
2467 if (cur->flg_read_only) {
2468 *pp++ = (char *) "-R";
2469 *pp++ = cur->varstr;
2470 } else if (!cur->flg_export) {
2471 *pp++ = (char *) "-V";
2472 *pp++ = cur->varstr;
2475 #if ENABLE_HUSH_FUNCTIONS
2476 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2477 *pp++ = (char *) "-F";
2478 *pp++ = funcp->name;
2479 *pp++ = funcp->body_as_string;
2482 /* We can pass activated traps here. Say, -Tnn:trap_string
2484 * However, POSIX says that subshells reset signals with traps
2486 * I tested bash-3.2 and it not only does that with true subshells
2487 * of the form ( list ), but with any forked children shells.
2488 * I set trap "echo W" WINCH; and then tried:
2490 * { echo 1; sleep 20; echo 2; } &
2491 * while true; do echo 1; sleep 20; echo 2; break; done &
2492 * true | { echo 1; sleep 20; echo 2; } | cat
2494 * In all these cases sending SIGWINCH to the child shell
2495 * did not run the trap. If I add trap "echo V" WINCH;
2496 * _inside_ group (just before echo 1), it works.
2498 * I conclude it means we don't need to pass active traps here.
2499 * exec syscall below resets them to SIG_DFL for us.
2501 *pp++ = (char *) "-c";
2506 /* *pp = NULL; - is already there */
2510 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2511 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2512 execve(bb_busybox_exec_path, argv, pp);
2513 /* Fallback. Useful for init=/bin/hush usage etc */
2514 if (argv[0][0] == '/')
2515 execve(argv[0], argv, pp);
2516 xfunc_error_retval = 127;
2517 bb_error_msg_and_die("can't re-execute the shell");
2519 #endif /* !BB_MMU */
2522 static void setup_heredoc(struct redir_struct *redir)
2524 struct fd_pair pair;
2527 /* the _body_ of heredoc (misleading field name) */
2528 const char *heredoc = redir->rd_filename;
2535 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2536 expanded = expand_pseudo_dquoted(heredoc);
2540 len = strlen(heredoc);
2542 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2544 xmove_fd(pair.rd, redir->rd_fd);
2546 /* Try writing without forking. Newer kernels have
2547 * dynamically growing pipes. Must use non-blocking write! */
2550 written = write(pair.wr, heredoc, len);
2561 ndelay_off(pair.wr);
2563 /* Okay, pipe buffer was not big enough */
2564 /* Note: we must not create a stray child (bastard? :)
2565 * for the unsuspecting parent process. Child creates a grandchild
2566 * and exits before parent execs the process which consumes heredoc
2567 * (that exec happens after we return from this function) */
2573 bb_perror_msg_and_die("vfork");
2576 disable_restore_tty_pgrp_on_exit();
2577 pid = BB_MMU ? fork() : vfork();
2579 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2583 close(redir->rd_fd); /* read side of the pipe */
2585 full_write(pair.wr, heredoc, len); /* may loop or block */
2588 /* Delegate blocking writes to another process */
2589 xmove_fd(pair.wr, STDOUT_FILENO);
2590 re_execute_shell(&to_free, heredoc, NULL, NULL);
2594 enable_restore_tty_pgrp_on_exit();
2600 wait(NULL); /* wait till child has died */
2603 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2604 * and stderr if they are redirected. */
2605 static int setup_redirects(struct command *prog, int squirrel[])
2608 struct redir_struct *redir;
2610 for (redir = prog->redirects; redir; redir = redir->next) {
2611 if (redir->rd_type == REDIRECT_HEREDOC2) {
2612 /* rd_fd<<HERE case */
2613 if (squirrel && redir->rd_fd < 3) {
2614 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2616 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2618 debug_printf_parse("set heredoc '%s'\n",
2619 redir->rd_filename);
2620 setup_heredoc(redir);
2624 if (redir->rd_dup == REDIRFD_TO_FILE) {
2625 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2627 if (redir->rd_filename == NULL) {
2628 /* Something went wrong in the parse.
2629 * Pretend it didn't happen */
2630 bb_error_msg("bug in redirect parse");
2633 mode = redir_table[redir->rd_type].mode;
2634 p = expand_string_to_string(redir->rd_filename);
2635 openfd = open_or_warn(p, mode);
2638 /* this could get lost if stderr has been redirected, but
2639 * bash and ash both lose it as well (though zsh doesn't!) */
2640 //what the above comment tries to say?
2644 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2645 openfd = redir->rd_dup;
2648 if (openfd != redir->rd_fd) {
2649 if (squirrel && redir->rd_fd < 3) {
2650 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2652 if (openfd == REDIRFD_CLOSE) {
2653 /* "n>-" means "close me" */
2654 close(redir->rd_fd);
2656 xdup2(openfd, redir->rd_fd);
2657 if (redir->rd_dup == REDIRFD_TO_FILE)
2665 static void restore_redirects(int squirrel[])
2668 for (i = 0; i < 3; i++) {
2671 /* We simply die on error */
2678 static void free_pipe_list(struct pipe *head);
2680 /* Return code is the exit status of the pipe */
2681 static void free_pipe(struct pipe *pi)
2684 struct command *command;
2685 struct redir_struct *r, *rnext;
2688 if (pi->stopped_cmds > 0) /* why? */
2690 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2691 for (i = 0; i < pi->num_cmds; i++) {
2692 command = &pi->cmds[i];
2693 debug_printf_clean(" command %d:\n", i);
2694 if (command->argv) {
2695 for (a = 0, p = command->argv; *p; a++, p++) {
2696 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2698 free_strings(command->argv);
2699 command->argv = NULL;
2701 /* not "else if": on syntax error, we may have both! */
2702 if (command->group) {
2703 debug_printf_clean(" begin group (grp_type:%d)\n",
2705 free_pipe_list(command->group);
2706 debug_printf_clean(" end group\n");
2707 command->group = NULL;
2709 /* else is crucial here.
2710 * If group != NULL, child_func is meaningless */
2711 #if ENABLE_HUSH_FUNCTIONS
2712 else if (command->child_func) {
2713 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2714 command->child_func->parent_cmd = NULL;
2718 free(command->group_as_string);
2719 command->group_as_string = NULL;
2721 for (r = command->redirects; r; r = rnext) {
2722 debug_printf_clean(" redirect %d%s",
2723 r->rd_fd, redir_table[r->rd_type].descrip);
2724 /* guard against the case >$FOO, where foo is unset or blank */
2725 if (r->rd_filename) {
2726 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2727 free(r->rd_filename);
2728 r->rd_filename = NULL;
2730 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2734 command->redirects = NULL;
2736 free(pi->cmds); /* children are an array, they get freed all at once */
2744 static void free_pipe_list(struct pipe *head)
2746 struct pipe *pi, *next;
2748 for (pi = head; pi; pi = next) {
2750 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2753 debug_printf_clean("pipe followup code %d\n", pi->followup);
2755 /*pi->next = NULL;*/
2761 static int run_list(struct pipe *pi);
2763 #define parse_stream(pstring, input, end_trigger) \
2764 parse_stream(input, end_trigger)
2766 static struct pipe *parse_stream(char **pstring,
2767 struct in_str *input,
2769 static void parse_and_run_string(const char *s);
2772 static const struct built_in_command* find_builtin(const char *name)
2774 const struct built_in_command *x;
2775 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2776 if (strcmp(name, x->cmd) != 0)
2778 debug_printf_exec("found builtin '%s'\n", name);
2784 #if ENABLE_HUSH_FUNCTIONS
2785 static const struct function *find_function(const char *name)
2787 const struct function *funcp = G.top_func;
2789 if (strcmp(name, funcp->name) == 0) {
2792 funcp = funcp->next;
2795 debug_printf_exec("found function '%s'\n", name);
2799 /* Note: takes ownership on name ptr */
2800 static struct function *new_function(char *name)
2802 struct function *funcp;
2803 struct function **funcpp = &G.top_func;
2805 while ((funcp = *funcpp) != NULL) {
2806 struct command *cmd;
2808 if (strcmp(funcp->name, name) != 0) {
2809 funcpp = &funcp->next;
2813 cmd = funcp->parent_cmd;
2814 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2816 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2818 /* Note: if !funcp->body, do not free body_as_string!
2819 * This is a special case of "-F name body" function:
2820 * body_as_string was not malloced! */
2822 free_pipe_list(funcp->body);
2824 free(funcp->body_as_string);
2828 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2829 cmd->argv[0] = funcp->name;
2830 cmd->group = funcp->body;
2832 cmd->group_as_string = funcp->body_as_string;
2837 debug_printf_exec("remembering new function '%s'\n", name);
2838 funcp = *funcpp = xzalloc(sizeof(*funcp));
2839 /*funcp->next = NULL;*/
2845 static void unset_func(const char *name)
2847 struct function *funcp;
2848 struct function **funcpp = &G.top_func;
2850 while ((funcp = *funcpp) != NULL) {
2851 if (strcmp(funcp->name, name) == 0) {
2852 *funcpp = funcp->next;
2853 /* funcp is unlinked now, deleting it */
2855 /* Note: if !funcp->body, do not free body_as_string!
2856 * This is a special case of "-F name body" function:
2857 * body_as_string was not malloced! */
2859 free_pipe_list(funcp->body);
2861 free(funcp->body_as_string);
2867 funcpp = &funcp->next;
2872 #define exec_function(nommu_save, funcp, argv) \
2873 exec_function(funcp, argv)
2875 static void exec_function(nommu_save_t *nommu_save,
2876 const struct function *funcp,
2877 char **argv) NORETURN;
2878 static void exec_function(nommu_save_t *nommu_save,
2879 const struct function *funcp,
2885 argv[0] = G.global_argv[0];
2886 G.global_argv = argv;
2890 /* On MMU, funcp->body is always non-NULL */
2891 n = run_list(funcp->body);
2895 re_execute_shell(&nommu_save->argv_from_re_execing,
2896 funcp->body_as_string,
2902 static int run_function(const struct function *funcp, char **argv)
2906 #if ENABLE_HUSH_FUNCTIONS
2910 save_and_replace_G_args(&sv, argv);
2911 #if ENABLE_HUSH_FUNCTIONS
2912 /* "we are in function, ok to use return" */
2913 sv_flg = G.flag_return_in_progress;
2914 G.flag_return_in_progress = -1;
2917 /* On MMU, funcp->body is always non-NULL */
2920 /* Function defined by -F */
2921 parse_and_run_string(funcp->body_as_string);
2922 rc = G.last_exitcode;
2926 rc = run_list(funcp->body);
2929 #if ENABLE_HUSH_FUNCTIONS
2930 G.flag_return_in_progress = sv_flg;
2932 restore_G_args(&sv, argv);
2940 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2941 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2942 #define pseudo_exec(nommu_save, command, argv_expanded) \
2943 pseudo_exec(command, argv_expanded)
2946 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2948 * Don't exit() here. If you don't exec, use _exit instead.
2949 * The at_exit handlers apparently confuse the calling process,
2950 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2951 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2952 char **argv, int assignment_cnt,
2953 char **argv_expanded) NORETURN;
2954 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2955 char **argv, int assignment_cnt,
2956 char **argv_expanded)
2960 /* Case when we are here: ... | var=val | ... */
2961 if (!argv[assignment_cnt])
2962 _exit(EXIT_SUCCESS);
2964 new_env = expand_assignments(argv, assignment_cnt);
2966 putenv_all(new_env);
2967 free(new_env); /* optional */
2969 nommu_save->new_env = new_env;
2970 nommu_save->old_env = putenv_all_and_save_old(new_env);
2972 if (argv_expanded) {
2973 argv = argv_expanded;
2975 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2977 nommu_save->argv = argv;
2981 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2982 if (strchr(argv[0], '/') != NULL)
2986 /* On NOMMU, we must never block!
2987 * Example: { sleep 99999 | read line } & echo Ok
2988 * read builtin will block on read syscall, leaving parent blocked
2989 * in vfork. Therefore we can't do this:
2992 /* Check if the command matches any of the builtins.
2993 * Depending on context, this might be redundant. But it's
2994 * easier to waste a few CPU cycles than it is to figure out
2995 * if this is one of those cases.
2999 const struct built_in_command *x = find_builtin(argv[0]);
3001 rcode = x->function(argv);
3007 #if ENABLE_HUSH_FUNCTIONS
3008 /* Check if the command matches any functions */
3010 const struct function *funcp = find_function(argv[0]);
3012 exec_function(nommu_save, funcp, argv);
3017 #if ENABLE_FEATURE_SH_STANDALONE
3018 /* Check if the command matches any busybox applets */
3020 int a = find_applet_by_name(argv[0]);
3022 # if BB_MMU /* see above why on NOMMU it is not allowed */
3023 if (APPLET_IS_NOEXEC(a)) {
3024 debug_printf_exec("running applet '%s'\n", argv[0]);
3025 run_applet_no_and_exit(a, argv);
3028 /* Re-exec ourselves */
3029 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3030 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3031 execv(bb_busybox_exec_path, argv);
3032 /* If they called chroot or otherwise made the binary no longer
3033 * executable, fall through */
3038 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3041 debug_printf_exec("execing '%s'\n", argv[0]);
3042 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3043 execvp(argv[0], argv);
3044 bb_perror_msg("can't exec '%s'", argv[0]);
3045 _exit(EXIT_FAILURE);
3048 /* Called after [v]fork() in run_pipe
3050 static void pseudo_exec(nommu_save_t *nommu_save,
3051 struct command *command,
3052 char **argv_expanded) NORETURN;
3053 static void pseudo_exec(nommu_save_t *nommu_save,
3054 struct command *command,
3055 char **argv_expanded)
3057 if (command->argv) {
3058 pseudo_exec_argv(nommu_save, command->argv,
3059 command->assignment_cnt, argv_expanded);
3062 if (command->group) {
3063 /* Cases when we are here:
3066 * ... | ( list ) | ...
3067 * ... | { list } | ...
3071 debug_printf_exec("pseudo_exec: run_list\n");
3072 reset_traps_to_defaults();
3073 rcode = run_list(command->group);
3074 /* OK to leak memory by not calling free_pipe_list,
3075 * since this process is about to exit */
3078 re_execute_shell(&nommu_save->argv_from_re_execing,
3079 command->group_as_string,
3085 /* Case when we are here: ... | >file */
3086 debug_printf_exec("pseudo_exec'ed null command\n");
3087 _exit(EXIT_SUCCESS);
3091 static const char *get_cmdtext(struct pipe *pi)
3097 /* This is subtle. ->cmdtext is created only on first backgrounding.
3098 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3099 * On subsequent bg argv is trashed, but we won't use it */
3102 argv = pi->cmds[0].argv;
3103 if (!argv || !argv[0]) {
3104 pi->cmdtext = xzalloc(1);
3110 len += strlen(*argv) + 1;
3113 pi->cmdtext = p;// = xmalloc(len);
3114 argv = pi->cmds[0].argv;
3116 len = strlen(*argv);
3117 memcpy(p, *argv, len);
3125 static void insert_bg_job(struct pipe *pi)
3127 struct pipe *job, **jobp;
3130 /* Linear search for the ID of the job to use */
3132 for (job = G.job_list; job; job = job->next)
3133 if (job->jobid >= pi->jobid)
3134 pi->jobid = job->jobid + 1;
3136 /* Add job to the list of running jobs */
3138 while ((job = *jobp) != NULL)
3140 job = *jobp = xmalloc(sizeof(*job));
3142 *job = *pi; /* physical copy */
3144 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3145 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3146 for (i = 0; i < pi->num_cmds; i++) {
3147 job->cmds[i].pid = pi->cmds[i].pid;
3148 /* all other fields are not used and stay zero */
3150 job->cmdtext = xstrdup(get_cmdtext(pi));
3152 if (G_interactive_fd)
3153 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3154 /* Last command's pid goes to $! */
3155 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3156 G.last_jobid = job->jobid;
3159 static void remove_bg_job(struct pipe *pi)
3161 struct pipe *prev_pipe;
3163 if (pi == G.job_list) {
3164 G.job_list = pi->next;
3166 prev_pipe = G.job_list;
3167 while (prev_pipe->next != pi)
3168 prev_pipe = prev_pipe->next;
3169 prev_pipe->next = pi->next;
3172 G.last_jobid = G.job_list->jobid;
3177 /* Remove a backgrounded job */
3178 static void delete_finished_bg_job(struct pipe *pi)
3181 pi->stopped_cmds = 0;
3187 /* Check to see if any processes have exited -- if they
3188 * have, figure out why and see if a job has completed */
3189 static int checkjobs(struct pipe* fg_pipe)
3199 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3202 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3203 // /* avoid doing syscall, nothing there anyway */
3206 attributes = WUNTRACED;
3207 if (fg_pipe == NULL)
3208 attributes |= WNOHANG;
3210 /* Do we do this right?
3211 * bash-3.00# sleep 20 | false
3213 * [3]+ Stopped sleep 20 | false
3214 * bash-3.00# echo $?
3215 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3216 * [hush 1.14.0: yes we do it right]
3223 // i = G.count_SIGCHLD;
3224 childpid = waitpid(-1, &status, attributes);
3225 if (childpid <= 0) {
3226 if (childpid && errno != ECHILD)
3227 bb_perror_msg("waitpid");
3228 // else /* Until next SIGCHLD, waitpid's are useless */
3229 // G.handled_SIGCHLD = i;
3232 dead = WIFEXITED(status) || WIFSIGNALED(status);
3235 if (WIFSTOPPED(status))
3236 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3237 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3238 if (WIFSIGNALED(status))
3239 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3240 childpid, WTERMSIG(status), WEXITSTATUS(status));
3241 if (WIFEXITED(status))
3242 debug_printf_jobs("pid %d exited, exitcode %d\n",
3243 childpid, WEXITSTATUS(status));
3245 /* Were we asked to wait for fg pipe? */
3247 for (i = 0; i < fg_pipe->num_cmds; i++) {
3248 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3249 if (fg_pipe->cmds[i].pid != childpid)
3252 fg_pipe->cmds[i].pid = 0;
3253 fg_pipe->alive_cmds--;
3254 if (i == fg_pipe->num_cmds - 1) {
3255 /* last process gives overall exitstatus */
3256 /* Note: is WIFSIGNALED, WEXITSTATUS = sig + 128 */
3257 rcode = WEXITSTATUS(status);
3258 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3259 /* bash prints killing signal's name for *last*
3260 * process in pipe (prints just newline for SIGINT).
3261 * Mimic this. Example: "sleep 5" + ^\
3263 if (WIFSIGNALED(status)) {
3264 int sig = WTERMSIG(status);
3265 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
3269 fg_pipe->cmds[i].is_stopped = 1;
3270 fg_pipe->stopped_cmds++;
3272 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3273 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3274 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3275 /* All processes in fg pipe have exited or stopped */
3276 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3277 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3278 * and "killall -STOP cat" */
3279 if (G_interactive_fd) {
3281 if (fg_pipe->alive_cmds)
3282 insert_bg_job(fg_pipe);
3287 /* There are still running processes in the fg pipe */
3288 goto wait_more; /* do waitpid again */
3290 /* it wasnt fg_pipe, look for process in bg pipes */
3294 /* We asked to wait for bg or orphaned children */
3295 /* No need to remember exitcode in this case */
3296 for (pi = G.job_list; pi; pi = pi->next) {
3297 for (i = 0; i < pi->num_cmds; i++) {
3298 if (pi->cmds[i].pid == childpid)
3299 goto found_pi_and_prognum;
3302 /* Happens when shell is used as init process (init=/bin/sh) */
3303 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3304 continue; /* do waitpid again */
3306 found_pi_and_prognum:
3309 pi->cmds[i].pid = 0;
3311 if (!pi->alive_cmds) {
3312 if (G_interactive_fd)
3313 printf(JOB_STATUS_FORMAT, pi->jobid,
3314 "Done", pi->cmdtext);
3315 delete_finished_bg_job(pi);
3319 pi->cmds[i].is_stopped = 1;
3323 } /* while (waitpid succeeds)... */
3329 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3332 int rcode = checkjobs(fg_pipe);
3333 /* Job finished, move the shell to the foreground */
3334 p = getpgid(0); /* pgid of our process */
3335 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3336 tcsetpgrp(G_interactive_fd, p);
3341 /* Start all the jobs, but don't wait for anything to finish.
3344 * Return code is normally -1, when the caller has to wait for children
3345 * to finish to determine the exit status of the pipe. If the pipe
3346 * is a simple builtin command, however, the action is done by the
3347 * time run_pipe returns, and the exit code is provided as the
3350 * Returns -1 only if started some children. IOW: we have to
3351 * mask out retvals of builtins etc with 0xff!
3353 * The only case when we do not need to [v]fork is when the pipe
3354 * is single, non-backgrounded, non-subshell command. Examples:
3355 * cmd ; ... { list } ; ...
3356 * cmd && ... { list } && ...
3357 * cmd || ... { list } || ...
3358 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3359 * or (if SH_STANDALONE) an applet, and we can run the { list }
3360 * with run_list. If it isn't one of these, we fork and exec cmd.
3362 * Cases when we must fork:
3363 * non-single: cmd | cmd
3364 * backgrounded: cmd & { list } &
3365 * subshell: ( list ) [&]
3367 static int run_pipe(struct pipe *pi)
3369 static const char *const null_ptr = NULL;
3372 int pipefds[2]; /* pipefds[0] is for reading */
3373 struct command *command;
3374 char **argv_expanded;
3377 /* it is not always needed, but we aim to smaller code */
3378 int squirrel[] = { -1, -1, -1 };
3381 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3384 USE_HUSH_JOB(pi->pgrp = -1;)
3385 pi->stopped_cmds = 0;
3386 command = &(pi->cmds[0]);
3387 argv_expanded = NULL;
3389 if (pi->num_cmds != 1
3390 || pi->followup == PIPE_BG
3391 || command->grp_type == GRP_SUBSHELL
3398 debug_printf_exec(": group:%p argv:'%s'\n",
3399 command->group, command->argv ? command->argv[0] : "NONE");
3401 if (command->group) {
3402 #if ENABLE_HUSH_FUNCTIONS
3403 if (command->grp_type == GRP_FUNCTION) {
3404 /* "executing" func () { list } */
3405 struct function *funcp;
3407 funcp = new_function(command->argv[0]);
3408 /* funcp->name is already set to argv[0] */
3409 funcp->body = command->group;
3411 funcp->body_as_string = command->group_as_string;
3412 command->group_as_string = NULL;
3414 command->group = NULL;
3415 command->argv[0] = NULL;
3416 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3417 funcp->parent_cmd = command;
3418 command->child_func = funcp;
3420 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3422 return EXIT_SUCCESS;
3426 debug_printf("non-subshell group\n");
3427 rcode = 1; /* exitcode if redir failed */
3428 if (setup_redirects(command, squirrel) == 0) {
3429 debug_printf_exec(": run_list\n");
3430 rcode = run_list(command->group) & 0xff;
3432 restore_redirects(squirrel);
3433 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3435 debug_printf_exec("run_pipe: return %d\n", rcode);
3439 argv = command->argv ? command->argv : (char **) &null_ptr;
3441 const struct built_in_command *x;
3442 #if ENABLE_HUSH_FUNCTIONS
3443 const struct function *funcp;
3447 char **new_env = NULL;
3448 char **old_env = NULL;
3450 if (argv[command->assignment_cnt] == NULL) {
3451 /* Assignments, but no command */
3452 /* Ensure redirects take effect. Try "a=t >file" */
3453 rcode = setup_redirects(command, squirrel);
3454 restore_redirects(squirrel);
3455 /* Set shell variables */
3457 p = expand_string_to_string(*argv);
3458 debug_printf_exec("set shell var:'%s'->'%s'\n",
3460 set_local_var(p, 0, 0);
3463 /* Do we need to flag set_local_var() errors?
3464 * "assignment to readonly var" and "putenv error"
3466 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3468 debug_printf_exec("run_pipe: return %d\n", rcode);
3472 /* Expand the rest into (possibly) many strings each */
3473 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3475 x = find_builtin(argv_expanded[0]);
3476 #if ENABLE_HUSH_FUNCTIONS
3479 funcp = find_function(argv_expanded[0]);
3483 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3484 debug_printf("exec with redirects only\n");
3485 rcode = setup_redirects(command, NULL);
3486 goto clean_up_and_ret1;
3489 /* setup_redirects acts on file descriptors, not FILEs.
3490 * This is perfect for work that comes after exec().
3491 * Is it really safe for inline use? Experimentally,
3492 * things seem to work. */
3493 rcode = setup_redirects(command, squirrel);
3495 new_env = expand_assignments(argv, command->assignment_cnt);
3496 old_env = putenv_all_and_save_old(new_env);
3498 debug_printf_exec(": builtin '%s' '%s'...\n",
3499 x->cmd, argv_expanded[1]);
3500 rcode = x->function(argv_expanded) & 0xff;
3503 #if ENABLE_HUSH_FUNCTIONS
3505 debug_printf_exec(": function '%s' '%s'...\n",
3506 funcp->name, argv_expanded[1]);
3507 rcode = run_function(funcp, argv_expanded) & 0xff;
3511 #if ENABLE_FEATURE_SH_STANDALONE
3514 restore_redirects(squirrel);
3515 free_strings_and_unsetenv(new_env, 1);
3516 putenv_all(old_env);
3517 /* Free the pointers, but the strings themselves
3518 * are in environ now, don't use free_strings! */
3521 free(argv_expanded);
3522 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3524 debug_printf_exec("run_pipe return %d\n", rcode);
3528 #if ENABLE_FEATURE_SH_STANDALONE
3529 i = find_applet_by_name(argv_expanded[0]);
3530 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3531 rcode = setup_redirects(command, squirrel);
3533 new_env = expand_assignments(argv, command->assignment_cnt);
3534 old_env = putenv_all_and_save_old(new_env);
3535 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3536 argv_expanded[0], argv_expanded[1]);
3537 rcode = run_nofork_applet(i, argv_expanded);
3539 goto clean_up_and_ret;
3542 /* It is neither builtin nor applet. We must fork. */
3546 /* NB: argv_expanded may already be created, and that
3547 * might include `cmd` runs! Do not rerun it! We *must*
3548 * use argv_expanded if it's non-NULL */
3550 /* Going to fork a child per each pipe member */
3554 for (i = 0; i < pi->num_cmds; i++) {
3556 volatile nommu_save_t nommu_save;
3557 nommu_save.new_env = NULL;
3558 nommu_save.old_env = NULL;
3559 nommu_save.argv = NULL;
3560 nommu_save.argv_from_re_execing = NULL;
3562 command = &(pi->cmds[i]);
3563 if (command->argv) {
3564 debug_printf_exec(": pipe member '%s' '%s'...\n",
3565 command->argv[0], command->argv[1]);
3567 debug_printf_exec(": pipe member with no argv\n");
3570 /* pipes are inserted between pairs of commands */
3573 if ((i + 1) < pi->num_cmds)
3576 command->pid = BB_MMU ? fork() : vfork();
3577 if (!command->pid) { /* child */
3579 disable_restore_tty_pgrp_on_exit();
3581 /* Every child adds itself to new process group
3582 * with pgid == pid_of_first_child_in_pipe */
3583 if (G.run_list_level == 1 && G_interactive_fd) {
3586 if (pgrp < 0) /* true for 1st process only */
3588 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3589 /* We do it in *every* child, not just first,
3591 tcsetpgrp(G_interactive_fd, pgrp);
3595 xmove_fd(nextin, 0);
3596 xmove_fd(pipefds[1], 1); /* write end */
3598 close(pipefds[0]); /* read end */
3599 /* Like bash, explicit redirects override pipes,
3600 * and the pipe fd is available for dup'ing. */
3601 if (setup_redirects(command, NULL))
3604 /* Restore default handlers just prior to exec */
3605 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3607 /* Stores to nommu_save list of env vars putenv'ed
3608 * (NOMMU, on MMU we don't need that) */
3609 /* cast away volatility... */
3610 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3611 /* pseudo_exec() does not return */
3614 /* parent or error */
3615 enable_restore_tty_pgrp_on_exit();
3617 /* Clean up after vforked child */
3618 free(nommu_save.argv);
3619 free(nommu_save.argv_from_re_execing);
3620 free_strings_and_unsetenv(nommu_save.new_env, 1);
3621 putenv_all(nommu_save.old_env);
3622 /* Free the pointers, but the strings themselves
3623 * are in environ now, don't use free_strings! */
3624 free(nommu_save.old_env);
3626 free(argv_expanded);
3627 argv_expanded = NULL;
3628 if (command->pid < 0) { /* [v]fork failed */
3629 /* Clearly indicate, was it fork or vfork */
3630 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3634 /* Second and next children need to know pid of first one */
3636 pi->pgrp = command->pid;
3642 if ((i + 1) < pi->num_cmds)
3643 close(pipefds[1]); /* write end */
3644 /* Pass read (output) pipe end to next iteration */
3645 nextin = pipefds[0];
3648 if (!pi->alive_cmds) {
3650 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3655 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3659 #ifndef debug_print_tree
3660 static void debug_print_tree(struct pipe *pi, int lvl)
3662 static const char *const PIPE[] = {
3668 static const char *RES[] = {
3669 [RES_NONE ] = "NONE" ,
3672 [RES_THEN ] = "THEN" ,
3673 [RES_ELIF ] = "ELIF" ,
3674 [RES_ELSE ] = "ELSE" ,
3677 #if ENABLE_HUSH_LOOPS
3678 [RES_FOR ] = "FOR" ,
3679 [RES_WHILE] = "WHILE",
3680 [RES_UNTIL] = "UNTIL",
3682 [RES_DONE ] = "DONE" ,
3684 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3687 #if ENABLE_HUSH_CASE
3688 [RES_CASE ] = "CASE" ,
3689 [RES_MATCH] = "MATCH",
3690 [RES_CASEI] = "CASEI",
3691 [RES_ESAC ] = "ESAC" ,
3693 [RES_XXXX ] = "XXXX" ,
3694 [RES_SNTX ] = "SNTX" ,
3696 static const char *const GRPTYPE[] = {
3699 #if ENABLE_HUSH_FUNCTIONS
3708 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3709 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3711 while (prn < pi->num_cmds) {
3712 struct command *command = &pi->cmds[prn];
3713 char **argv = command->argv;
3715 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3717 command->assignment_cnt);
3718 if (command->group) {
3719 fprintf(stderr, " group %s: (argv=%p)\n",
3720 GRPTYPE[command->grp_type],
3722 debug_print_tree(command->group, lvl+1);
3726 if (argv) while (*argv) {
3727 fprintf(stderr, " '%s'", *argv);
3730 fprintf(stderr, "\n");
3739 /* NB: called by pseudo_exec, and therefore must not modify any
3740 * global data until exec/_exit (we can be a child after vfork!) */
3741 static int run_list(struct pipe *pi)
3743 #if ENABLE_HUSH_CASE
3744 char *case_word = NULL;
3746 #if ENABLE_HUSH_LOOPS
3747 struct pipe *loop_top = NULL;
3748 char *for_varname = NULL;
3749 char **for_lcur = NULL;
3750 char **for_list = NULL;
3752 smallint last_followup;
3754 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3755 smalluint cond_code = 0;
3757 enum { cond_code = 0 };
3760 smallint rword; /* enum reserved_style */
3761 smallint last_rword; /* ditto */
3764 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3767 #if ENABLE_HUSH_LOOPS
3768 /* Check syntax for "for" */
3769 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3770 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3772 /* current word is FOR or IN (BOLD in comments below) */
3773 if (cpipe->next == NULL) {
3774 syntax_error("malformed for");
3776 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3779 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3780 if (cpipe->next->res_word == RES_DO)
3782 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3783 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3784 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3786 syntax_error("malformed for");
3788 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3794 /* Past this point, all code paths should jump to ret: label
3795 * in order to return, no direct "return" statements please.
3796 * This helps to ensure that no memory is leaked. */
3804 last_rword = RES_XXXX;
3806 last_followup = PIPE_SEQ;
3807 rcode = G.last_exitcode;
3809 /* Go through list of pipes, (maybe) executing them. */
3810 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3814 IF_HAS_KEYWORDS(rword = pi->res_word;)
3815 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3816 rword, cond_code, last_rword);
3817 #if ENABLE_HUSH_LOOPS
3818 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3819 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3821 /* start of a loop: remember where loop starts */
3826 /* Still in the same "if...", "then..." or "do..." branch? */
3827 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3828 if ((rcode == 0 && last_followup == PIPE_OR)
3829 || (rcode != 0 && last_followup == PIPE_AND)
3831 /* It is "<true> || CMD" or "<false> && CMD"
3832 * and we should not execute CMD */
3833 debug_printf_exec("skipped cmd because of || or &&\n");
3834 last_followup = pi->followup;
3838 last_followup = pi->followup;
3839 IF_HAS_KEYWORDS(last_rword = rword;)
3842 if (rword == RES_THEN) {
3843 /* if false; then ... fi has exitcode 0! */
3844 G.last_exitcode = rcode = EXIT_SUCCESS;
3845 /* "if <false> THEN cmd": skip cmd */
3849 if (rword == RES_ELSE || rword == RES_ELIF) {
3850 /* "if <true> then ... ELSE/ELIF cmd":
3851 * skip cmd and all following ones */
3856 #if ENABLE_HUSH_LOOPS
3857 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3859 /* first loop through for */
3861 static const char encoded_dollar_at[] ALIGN1 = {
3862 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3863 }; /* encoded representation of "$@" */
3864 static const char *const encoded_dollar_at_argv[] = {
3865 encoded_dollar_at, NULL
3866 }; /* argv list with one element: "$@" */
3869 vals = (char**)encoded_dollar_at_argv;
3870 if (pi->next->res_word == RES_IN) {
3871 /* if no variable values after "in" we skip "for" */
3872 if (!pi->next->cmds[0].argv) {
3873 G.last_exitcode = rcode = EXIT_SUCCESS;
3874 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3877 vals = pi->next->cmds[0].argv;
3878 } /* else: "for var; do..." -> assume "$@" list */
3879 /* create list of variable values */
3880 debug_print_strings("for_list made from", vals);
3881 for_list = expand_strvec_to_strvec(vals);
3882 for_lcur = for_list;
3883 debug_print_strings("for_list", for_list);
3884 for_varname = pi->cmds[0].argv[0];
3885 pi->cmds[0].argv[0] = NULL;
3887 free(pi->cmds[0].argv[0]);
3889 /* "for" loop is over, clean up */
3893 pi->cmds[0].argv[0] = for_varname;
3896 /* Insert next value from for_lcur */
3897 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3898 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3899 pi->cmds[0].assignment_cnt = 1;
3901 if (rword == RES_IN) {
3902 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3904 if (rword == RES_DONE) {
3905 continue; /* "done" has no cmds too */
3908 #if ENABLE_HUSH_CASE
3909 if (rword == RES_CASE) {
3910 case_word = expand_strvec_to_string(pi->cmds->argv);
3913 if (rword == RES_MATCH) {
3916 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3918 /* all prev words didn't match, does this one match? */
3919 argv = pi->cmds->argv;
3921 char *pattern = expand_string_to_string(*argv);
3922 /* TODO: which FNM_xxx flags to use? */
3923 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3925 if (cond_code == 0) { /* match! we will execute this branch */
3926 free(case_word); /* make future "word)" stop */
3934 if (rword == RES_CASEI) { /* inside of a case branch */
3936 continue; /* not matched yet, skip this pipe */
3939 /* Just pressing <enter> in shell should check for jobs.
3940 * OTOH, in non-interactive shell this is useless
3941 * and only leads to extra job checks */
3942 if (pi->num_cmds == 0) {
3943 if (G_interactive_fd)
3944 goto check_jobs_and_continue;
3948 /* After analyzing all keywords and conditions, we decided
3949 * to execute this pipe. NB: have to do checkjobs(NULL)
3950 * after run_pipe to collect any background children,
3951 * even if list execution is to be stopped. */
3952 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3955 #if ENABLE_HUSH_LOOPS
3956 G.flag_break_continue = 0;
3958 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3960 /* We ran a builtin, function, or group.
3961 * rcode is already known
3962 * and we don't need to wait for anything. */
3963 G.last_exitcode = rcode;
3964 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3965 check_and_run_traps(0);
3966 #if ENABLE_HUSH_LOOPS
3967 /* Was it "break" or "continue"? */
3968 if (G.flag_break_continue) {
3969 smallint fbc = G.flag_break_continue;
3970 /* We might fall into outer *loop*,
3971 * don't want to break it too */
3973 G.depth_break_continue--;
3974 if (G.depth_break_continue == 0)
3975 G.flag_break_continue = 0;
3976 /* else: e.g. "continue 2" should *break* once, *then* continue */
3977 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3978 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3979 goto check_jobs_and_break;
3980 /* "continue": simulate end of loop */
3985 #if ENABLE_HUSH_FUNCTIONS
3986 if (G.flag_return_in_progress == 1)
3987 goto check_jobs_and_break;
3989 } else if (pi->followup == PIPE_BG) {
3990 /* What does bash do with attempts to background builtins? */
3991 /* even bash 3.2 doesn't do that well with nested bg:
3992 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3993 * I'm NOT treating inner &'s as jobs */
3994 check_and_run_traps(0);
3996 if (G.run_list_level == 1)
3998 debug_printf_exec("insert_bg_job1\n");
4000 debug_printf_exec("insert_bg_job2\n");
4003 G.last_exitcode = rcode = EXIT_SUCCESS;
4004 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
4007 if (G.run_list_level == 1 && G_interactive_fd) {
4008 /* Waits for completion, then fg's main shell */
4009 rcode = checkjobs_and_fg_shell(pi);
4010 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4011 check_and_run_traps(0);
4014 { /* This one just waits for completion */
4015 rcode = checkjobs(pi);
4016 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4017 check_and_run_traps(0);
4019 G.last_exitcode = rcode;
4023 /* Analyze how result affects subsequent commands */
4025 if (rword == RES_IF || rword == RES_ELIF)
4028 #if ENABLE_HUSH_LOOPS
4029 /* Beware of "while false; true; do ..."! */
4030 if (pi->next && pi->next->res_word == RES_DO) {
4031 if (rword == RES_WHILE) {
4033 /* "while false; do...done" - exitcode 0 */
4034 G.last_exitcode = rcode = EXIT_SUCCESS;
4035 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4036 goto check_jobs_and_break;
4039 if (rword == RES_UNTIL) {
4041 debug_printf_exec(": until expr is true: breaking\n");
4042 check_jobs_and_break:
4050 check_jobs_and_continue:
4057 #if ENABLE_HUSH_LOOPS
4062 #if ENABLE_HUSH_CASE
4066 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4070 /* Select which version we will use */
4071 static int run_and_free_list(struct pipe *pi)
4074 debug_printf_exec("run_and_free_list entered\n");
4076 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4077 rcode = run_list(pi);
4079 /* free_pipe_list has the side effect of clearing memory.
4080 * In the long run that function can be merged with run_list,
4081 * but doing that now would hobble the debugging effort. */
4083 debug_printf_exec("run_and_free_list return %d\n", rcode);
4088 static struct pipe *new_pipe(void)
4091 pi = xzalloc(sizeof(struct pipe));
4092 /*pi->followup = 0; - deliberately invalid value */
4093 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4097 /* Command (member of a pipe) is complete, or we start a new pipe
4098 * if ctx->command is NULL.
4099 * No errors possible here.
4101 static int done_command(struct parse_context *ctx)
4103 /* The command is really already in the pipe structure, so
4104 * advance the pipe counter and make a new, null command. */
4105 struct pipe *pi = ctx->pipe;
4106 struct command *command = ctx->command;
4109 if (IS_NULL_CMD(command)) {
4110 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4114 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4115 //debug_print_tree(ctx->list_head, 20);
4117 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4120 /* Only real trickiness here is that the uncommitted
4121 * command structure is not counted in pi->num_cmds. */
4122 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4123 ctx->command = command = &pi->cmds[pi->num_cmds];
4125 memset(command, 0, sizeof(*command));
4126 return pi->num_cmds; /* used only for 0/nonzero check */
4129 static void done_pipe(struct parse_context *ctx, pipe_style type)
4133 debug_printf_parse("done_pipe entered, followup %d\n", type);
4134 /* Close previous command */
4135 not_null = done_command(ctx);
4136 ctx->pipe->followup = type;
4138 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4139 ctx->ctx_inverted = 0;
4140 ctx->pipe->res_word = ctx->ctx_res_w;
4143 /* Without this check, even just <enter> on command line generates
4144 * tree of three NOPs (!). Which is harmless but annoying.
4145 * IOW: it is safe to do it unconditionally. */
4148 || ctx->ctx_res_w == RES_FI
4150 #if ENABLE_HUSH_LOOPS
4151 || ctx->ctx_res_w == RES_DONE
4152 || ctx->ctx_res_w == RES_FOR
4153 || ctx->ctx_res_w == RES_IN
4155 #if ENABLE_HUSH_CASE
4156 || ctx->ctx_res_w == RES_ESAC
4160 debug_printf_parse("done_pipe: adding new pipe: "
4161 "not_null:%d ctx->ctx_res_w:%d\n",
4162 not_null, ctx->ctx_res_w);
4164 ctx->pipe->next = new_p;
4166 /* RES_THEN, RES_DO etc are "sticky" -
4167 * they remain set for pipes inside if/while.
4168 * This is used to control execution.
4169 * RES_FOR and RES_IN are NOT sticky (needed to support
4170 * cases where variable or value happens to match a keyword):
4172 #if ENABLE_HUSH_LOOPS
4173 if (ctx->ctx_res_w == RES_FOR
4174 || ctx->ctx_res_w == RES_IN)
4175 ctx->ctx_res_w = RES_NONE;
4177 #if ENABLE_HUSH_CASE
4178 if (ctx->ctx_res_w == RES_MATCH)
4179 ctx->ctx_res_w = RES_CASEI;
4181 ctx->command = NULL; /* trick done_command below */
4182 /* Create the memory for command, roughly:
4183 * ctx->pipe->cmds = new struct command;
4184 * ctx->command = &ctx->pipe->cmds[0];
4187 //debug_print_tree(ctx->list_head, 10);
4189 debug_printf_parse("done_pipe return\n");
4192 static void initialize_context(struct parse_context *ctx)
4194 memset(ctx, 0, sizeof(*ctx));
4195 ctx->pipe = ctx->list_head = new_pipe();
4196 /* Create the memory for command, roughly:
4197 * ctx->pipe->cmds = new struct command;
4198 * ctx->command = &ctx->pipe->cmds[0];
4203 /* If a reserved word is found and processed, parse context is modified
4204 * and 1 is returned.
4207 struct reserved_combo {
4210 unsigned char assignment_flag;
4214 FLAG_END = (1 << RES_NONE ),
4216 FLAG_IF = (1 << RES_IF ),
4217 FLAG_THEN = (1 << RES_THEN ),
4218 FLAG_ELIF = (1 << RES_ELIF ),
4219 FLAG_ELSE = (1 << RES_ELSE ),
4220 FLAG_FI = (1 << RES_FI ),
4222 #if ENABLE_HUSH_LOOPS
4223 FLAG_FOR = (1 << RES_FOR ),
4224 FLAG_WHILE = (1 << RES_WHILE),
4225 FLAG_UNTIL = (1 << RES_UNTIL),
4226 FLAG_DO = (1 << RES_DO ),
4227 FLAG_DONE = (1 << RES_DONE ),
4228 FLAG_IN = (1 << RES_IN ),
4230 #if ENABLE_HUSH_CASE
4231 FLAG_MATCH = (1 << RES_MATCH),
4232 FLAG_ESAC = (1 << RES_ESAC ),
4234 FLAG_START = (1 << RES_XXXX ),
4237 static const struct reserved_combo* match_reserved_word(o_string *word)
4239 /* Mostly a list of accepted follow-up reserved words.
4240 * FLAG_END means we are done with the sequence, and are ready
4241 * to turn the compound list into a command.
4242 * FLAG_START means the word must start a new compound list.
4244 static const struct reserved_combo reserved_list[] = {
4246 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4247 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4248 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4249 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4250 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4251 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4253 #if ENABLE_HUSH_LOOPS
4254 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4255 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4256 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4257 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4258 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4259 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4261 #if ENABLE_HUSH_CASE
4262 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4263 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4266 const struct reserved_combo *r;
4268 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4269 if (strcmp(word->data, r->literal) == 0)
4274 /* Return 0: not a keyword, 1: keyword
4276 static int reserved_word(o_string *word, struct parse_context *ctx)
4278 #if ENABLE_HUSH_CASE
4279 static const struct reserved_combo reserved_match = {
4280 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4283 const struct reserved_combo *r;
4287 r = match_reserved_word(word);
4291 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4292 #if ENABLE_HUSH_CASE
4293 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4294 /* "case word IN ..." - IN part starts first match part */
4295 r = &reserved_match;
4298 if (r->flag == 0) { /* '!' */
4299 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4300 syntax_error("! ! command");
4301 ctx->ctx_res_w = RES_SNTX;
4303 ctx->ctx_inverted = 1;
4306 if (r->flag & FLAG_START) {
4307 struct parse_context *old;
4309 old = xmalloc(sizeof(*old));
4310 debug_printf_parse("push stack %p\n", old);
4311 *old = *ctx; /* physical copy */
4312 initialize_context(ctx);
4314 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4315 syntax_error_at(word->data);
4316 ctx->ctx_res_w = RES_SNTX;
4319 /* "{...} fi" is ok. "{...} if" is not
4321 * if { echo foo; } then { echo bar; } fi */
4322 if (ctx->command->group)
4323 done_pipe(ctx, PIPE_SEQ);
4326 ctx->ctx_res_w = r->res;
4327 ctx->old_flag = r->flag;
4328 word->o_assignment = r->assignment_flag;
4330 if (ctx->old_flag & FLAG_END) {
4331 struct parse_context *old;
4333 done_pipe(ctx, PIPE_SEQ);
4334 debug_printf_parse("pop stack %p\n", ctx->stack);
4336 old->command->group = ctx->list_head;
4337 old->command->grp_type = GRP_NORMAL;
4339 o_addstr(&old->as_string, ctx->as_string.data);
4340 o_free_unsafe(&ctx->as_string);
4341 old->command->group_as_string = xstrdup(old->as_string.data);
4342 debug_printf_parse("pop, remembering as:'%s'\n",
4343 old->command->group_as_string);
4345 *ctx = *old; /* physical copy */
4352 /* Word is complete, look at it and update parsing context.
4353 * Normal return is 0. Syntax errors return 1.
4354 * Note: on return, word is reset, but not o_free'd!
4356 static int done_word(o_string *word, struct parse_context *ctx)
4358 struct command *command = ctx->command;
4360 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4361 if (word->length == 0 && word->o_quoted == 0) {
4362 debug_printf_parse("done_word return 0: true null, ignored\n");
4366 if (ctx->pending_redirect) {
4367 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4368 * only if run as "bash", not "sh" */
4369 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4371 * ...the word that follows the redirection operator
4372 * shall be subjected to tilde expansion, parameter expansion,
4373 * command substitution, arithmetic expansion, and quote
4374 * removal. Pathname expansion shall not be performed
4375 * on the word by a non-interactive shell; an interactive
4376 * shell may perform it, but shall do so only when
4377 * the expansion would result in one word."
4379 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4380 /* Cater for >\file case:
4381 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4382 * Same with heredocs:
4383 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4385 unbackslash(ctx->pending_redirect->rd_filename);
4386 /* Is it <<"HEREDOC"? */
4387 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4390 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4392 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4393 ctx->pending_redirect = NULL;
4395 /* If this word wasn't an assignment, next ones definitely
4396 * can't be assignments. Even if they look like ones. */
4397 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4398 && word->o_assignment != WORD_IS_KEYWORD
4400 word->o_assignment = NOT_ASSIGNMENT;
4402 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4403 command->assignment_cnt++;
4404 word->o_assignment = MAYBE_ASSIGNMENT;
4408 # if ENABLE_HUSH_CASE
4409 if (ctx->ctx_dsemicolon
4410 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4412 /* already done when ctx_dsemicolon was set to 1: */
4413 /* ctx->ctx_res_w = RES_MATCH; */
4414 ctx->ctx_dsemicolon = 0;
4417 if (!command->argv /* if it's the first word... */
4418 # if ENABLE_HUSH_LOOPS
4419 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4420 && ctx->ctx_res_w != RES_IN
4423 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4424 if (reserved_word(word, ctx)) {
4425 o_reset_to_empty_unquoted(word);
4426 debug_printf_parse("done_word return %d\n",
4427 (ctx->ctx_res_w == RES_SNTX));
4428 return (ctx->ctx_res_w == RES_SNTX);
4432 if (command->group) {
4433 /* "{ echo foo; } echo bar" - bad */
4434 syntax_error_at(word->data);
4435 debug_printf_parse("done_word return 1: syntax error, "
4436 "groups and arglists don't mix\n");
4439 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4440 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4441 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4442 /* (otherwise it's known to be not empty and is already safe) */
4444 /* exclude "$@" - it can expand to no word despite "" */
4445 char *p = word->data;
4446 while (p[0] == SPECIAL_VAR_SYMBOL
4447 && (p[1] & 0x7f) == '@'
4448 && p[2] == SPECIAL_VAR_SYMBOL
4452 if (p == word->data || p[0] != '\0') {
4453 /* saw no "$@", or not only "$@" but some
4454 * real text is there too */
4455 /* insert "empty variable" reference, this makes
4456 * e.g. "", $empty"" etc to not disappear */
4457 o_addchr(word, SPECIAL_VAR_SYMBOL);
4458 o_addchr(word, SPECIAL_VAR_SYMBOL);
4461 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4462 debug_print_strings("word appended to argv", command->argv);
4465 #if ENABLE_HUSH_LOOPS
4466 if (ctx->ctx_res_w == RES_FOR) {
4468 || !is_well_formed_var_name(command->argv[0], '\0')
4470 /* bash says just "not a valid identifier" */
4471 syntax_error("not a valid identifier in for");
4474 /* Force FOR to have just one word (variable name) */
4475 /* NB: basically, this makes hush see "for v in ..."
4476 * syntax as if it is "for v; in ...". FOR and IN become
4477 * two pipe structs in parse tree. */
4478 done_pipe(ctx, PIPE_SEQ);
4481 #if ENABLE_HUSH_CASE
4482 /* Force CASE to have just one word */
4483 if (ctx->ctx_res_w == RES_CASE) {
4484 done_pipe(ctx, PIPE_SEQ);
4488 o_reset_to_empty_unquoted(word);
4490 debug_printf_parse("done_word return 0\n");
4495 /* Peek ahead in the input to find out if we have a "&n" construct,
4496 * as in "2>&1", that represents duplicating a file descriptor.
4498 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4499 * REDIRFD_SYNTAX_ERR if syntax error,
4500 * REDIRFD_TO_FILE if no & was seen,
4501 * or the number found.
4504 #define parse_redir_right_fd(as_string, input) \
4505 parse_redir_right_fd(input)
4507 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4513 return REDIRFD_TO_FILE;
4515 ch = i_getch(input); /* get the & */
4516 nommu_addchr(as_string, ch);
4519 ch = i_getch(input);
4520 nommu_addchr(as_string, ch);
4521 return REDIRFD_CLOSE;
4525 while (ch != EOF && isdigit(ch)) {
4526 d = d*10 + (ch-'0');
4528 ch = i_getch(input);
4529 nommu_addchr(as_string, ch);
4534 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4536 bb_error_msg("ambiguous redirect");
4537 return REDIRFD_SYNTAX_ERR;
4540 /* Return code is 0 normal, 1 if a syntax error is detected
4542 static int parse_redirect(struct parse_context *ctx,
4545 struct in_str *input)
4547 struct command *command = ctx->command;
4548 struct redir_struct *redir;
4549 struct redir_struct **redirp;
4552 dup_num = REDIRFD_TO_FILE;
4553 if (style != REDIRECT_HEREDOC) {
4554 /* Check for a '>&1' type redirect */
4555 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4556 if (dup_num == REDIRFD_SYNTAX_ERR)
4559 int ch = i_peek(input);
4560 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4561 if (dup_num) { /* <<-... */
4562 ch = i_getch(input);
4563 nommu_addchr(&ctx->as_string, ch);
4568 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4569 int ch = i_peek(input);
4571 /* >|FILE redirect ("clobbering" >).
4572 * Since we do not support "set -o noclobber" yet,
4573 * >| and > are the same for now. Just eat |.
4575 ch = i_getch(input);
4576 nommu_addchr(&ctx->as_string, ch);
4580 /* Create a new redir_struct and append it to the linked list */
4581 redirp = &command->redirects;
4582 while ((redir = *redirp) != NULL) {
4583 redirp = &(redir->next);
4585 *redirp = redir = xzalloc(sizeof(*redir));
4586 /* redir->next = NULL; */
4587 /* redir->rd_filename = NULL; */
4588 redir->rd_type = style;
4589 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4591 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4592 redir_table[style].descrip);
4594 redir->rd_dup = dup_num;
4595 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4596 /* Erik had a check here that the file descriptor in question
4597 * is legit; I postpone that to "run time"
4598 * A "-" representation of "close me" shows up as a -3 here */
4599 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4600 redir->rd_fd, redir->rd_dup);
4602 /* Set ctx->pending_redirect, so we know what to do at the
4603 * end of the next parsed word. */
4604 ctx->pending_redirect = redir;
4609 /* If a redirect is immediately preceded by a number, that number is
4610 * supposed to tell which file descriptor to redirect. This routine
4611 * looks for such preceding numbers. In an ideal world this routine
4612 * needs to handle all the following classes of redirects...
4613 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4614 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4615 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4616 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4618 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4620 * ... If n is quoted, the number shall not be recognized as part of
4621 * the redirection expression. For example:
4623 * writes the character 2 into file a"
4624 * We are getting it right by setting ->o_quoted on any \<char>
4626 * A -1 return means no valid number was found,
4627 * the caller should use the appropriate default for this redirection.
4629 static int redirect_opt_num(o_string *o)
4633 if (o->data == NULL)
4635 num = bb_strtou(o->data, NULL, 10);
4636 if (errno || num < 0)
4638 o_reset_to_empty_unquoted(o);
4643 #define fetch_till_str(as_string, input, word, skip_tabs) \
4644 fetch_till_str(input, word, skip_tabs)
4646 static char *fetch_till_str(o_string *as_string,
4647 struct in_str *input,
4651 o_string heredoc = NULL_O_STRING;
4657 ch = i_getch(input);
4658 nommu_addchr(as_string, ch);
4660 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4661 heredoc.data[past_EOL] = '\0';
4662 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4663 return heredoc.data;
4666 o_addchr(&heredoc, ch);
4667 past_EOL = heredoc.length;
4670 ch = i_getch(input);
4671 nommu_addchr(as_string, ch);
4672 } while (skip_tabs && ch == '\t');
4673 } while (ch == '\n');
4676 o_free_unsafe(&heredoc);
4679 o_addchr(&heredoc, ch);
4680 nommu_addchr(as_string, ch);
4684 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4685 * and load them all. There should be exactly heredoc_cnt of them.
4687 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4689 struct pipe *pi = ctx->list_head;
4691 while (pi && heredoc_cnt) {
4693 struct command *cmd = pi->cmds;
4695 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4697 cmd->argv ? cmd->argv[0] : "NONE");
4698 for (i = 0; i < pi->num_cmds; i++) {
4699 struct redir_struct *redir = cmd->redirects;
4701 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4702 i, cmd->argv ? cmd->argv[0] : "NONE");
4704 if (redir->rd_type == REDIRECT_HEREDOC) {
4707 redir->rd_type = REDIRECT_HEREDOC2;
4708 /* redir->dup is (ab)used to indicate <<- */
4709 p = fetch_till_str(&ctx->as_string, input,
4710 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4712 syntax_error("unexpected EOF in here document");
4715 free(redir->rd_filename);
4716 redir->rd_filename = p;
4719 redir = redir->next;
4726 /* Should be 0. If it isn't, it's a parse error */
4728 bb_error_msg_and_die("heredoc BUG 2");
4734 #if ENABLE_HUSH_TICK
4735 static FILE *generate_stream_from_string(const char *s)
4738 int pid, channel[2];
4744 pid = BB_MMU ? fork() : vfork();
4746 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4748 if (pid == 0) { /* child */
4749 disable_restore_tty_pgrp_on_exit();
4750 /* Process substitution is not considered to be usual
4751 * 'command execution'.
4752 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4759 close(channel[0]); /* NB: close _first_, then move fd! */
4760 xmove_fd(channel[1], 1);
4761 /* Prevent it from trying to handle ctrl-z etc */
4762 USE_HUSH_JOB(G.run_list_level = 1;)
4764 reset_traps_to_defaults();
4765 parse_and_run_string(s);
4766 _exit(G.last_exitcode);
4768 /* We re-execute after vfork on NOMMU. This makes this script safe:
4769 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4770 * huge=`cat BIG` # was blocking here forever
4773 re_execute_shell(&to_free,
4781 enable_restore_tty_pgrp_on_exit();
4786 pf = fdopen(channel[0], "r");
4790 /* Return code is exit status of the process that is run. */
4791 static int process_command_subs(o_string *dest, const char *s)
4794 struct in_str pipe_str;
4797 pf = generate_stream_from_string(s);
4800 close_on_exec_on(fileno(pf));
4802 /* Now send results of command back into original context */
4803 setup_file_in_str(&pipe_str, pf);
4805 while ((ch = i_getch(&pipe_str)) != EOF) {
4811 o_addchr(dest, '\n');
4814 o_addQchr(dest, ch);
4817 debug_printf("done reading from pipe, pclose()ing\n");
4818 /* Note: we got EOF, and we just close the read end of the pipe.
4819 * We do not wait for the `cmd` child to terminate. bash and ash do.
4821 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4822 * `false`; echo $? - bash outputs "1"
4825 debug_printf("closed FILE from child. return 0\n");
4830 static int parse_group(o_string *dest, struct parse_context *ctx,
4831 struct in_str *input, int ch)
4833 /* dest contains characters seen prior to ( or {.
4834 * Typically it's empty, but for function defs,
4835 * it contains function name (without '()'). */
4836 struct pipe *pipe_list;
4838 struct command *command = ctx->command;
4840 debug_printf_parse("parse_group entered\n");
4841 #if ENABLE_HUSH_FUNCTIONS
4842 if (ch == '(' && !dest->o_quoted) {
4844 if (done_word(dest, ctx))
4847 goto skip; /* (... */
4848 if (command->argv[1]) { /* word word ... (... */
4849 syntax_error_unexpected_ch('(');
4852 /* it is "word(..." or "word (..." */
4854 ch = i_getch(input);
4855 while (ch == ' ' || ch == '\t');
4857 syntax_error_unexpected_ch(ch);
4860 nommu_addchr(&ctx->as_string, ch);
4862 ch = i_getch(input);
4863 while (ch == ' ' || ch == '\t' || ch == '\n');
4865 syntax_error_unexpected_ch(ch);
4868 nommu_addchr(&ctx->as_string, ch);
4869 command->grp_type = GRP_FUNCTION;
4873 if (command->argv /* word [word]{... */
4874 || dest->length /* word{... */
4875 || dest->o_quoted /* ""{... */
4878 debug_printf_parse("parse_group return 1: "
4879 "syntax error, groups and arglists don't mix\n");
4883 #if ENABLE_HUSH_FUNCTIONS
4889 command->grp_type = GRP_SUBSHELL;
4891 /* bash does not allow "{echo...", requires whitespace */
4892 ch = i_getch(input);
4893 if (ch != ' ' && ch != '\t' && ch != '\n') {
4894 syntax_error_unexpected_ch(ch);
4897 nommu_addchr(&ctx->as_string, ch);
4902 char *as_string = NULL;
4904 pipe_list = parse_stream(&as_string, input, endch);
4907 o_addstr(&ctx->as_string, as_string);
4909 /* empty ()/{} or parse error? */
4910 if (!pipe_list || pipe_list == ERR_PTR) {
4911 /* parse_stream already emitted error msg */
4915 debug_printf_parse("parse_group return 1: "
4916 "parse_stream returned %p\n", pipe_list);
4919 command->group = pipe_list;
4921 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4922 command->group_as_string = as_string;
4923 debug_printf_parse("end of group, remembering as:'%s'\n",
4924 command->group_as_string);
4927 debug_printf_parse("parse_group return 0\n");
4929 /* command remains "open", available for possible redirects */
4932 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4933 /* Subroutines for copying $(...) and `...` things */
4934 static void add_till_backquote(o_string *dest, struct in_str *input);
4936 static void add_till_single_quote(o_string *dest, struct in_str *input)
4939 int ch = i_getch(input);
4941 syntax_error_unterm_ch('\'');
4942 /*xfunc_die(); - redundant */
4949 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4950 static void add_till_double_quote(o_string *dest, struct in_str *input)
4953 int ch = i_getch(input);
4955 syntax_error_unterm_ch('"');
4956 /*xfunc_die(); - redundant */
4960 if (ch == '\\') { /* \x. Copy both chars. */
4962 ch = i_getch(input);
4966 add_till_backquote(dest, input);
4970 //if (ch == '$') ...
4973 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4975 * "Within the backquoted style of command substitution, backslash
4976 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4977 * The search for the matching backquote shall be satisfied by the first
4978 * backquote found without a preceding backslash; during this search,
4979 * if a non-escaped backquote is encountered within a shell comment,
4980 * a here-document, an embedded command substitution of the $(command)
4981 * form, or a quoted string, undefined results occur. A single-quoted
4982 * or double-quoted string that begins, but does not end, within the
4983 * "`...`" sequence produces undefined results."
4985 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4987 static void add_till_backquote(o_string *dest, struct in_str *input)
4990 int ch = i_getch(input);
4992 syntax_error_unterm_ch('`');
4993 /*xfunc_die(); - redundant */
4998 /* \x. Copy both chars unless it is \` */
4999 int ch2 = i_getch(input);
5001 syntax_error_unterm_ch('`');
5002 /*xfunc_die(); - redundant */
5004 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5011 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5012 * quoting and nested ()s.
5013 * "With the $(command) style of command substitution, all characters
5014 * following the open parenthesis to the matching closing parenthesis
5015 * constitute the command. Any valid shell script can be used for command,
5016 * except a script consisting solely of redirections which produces
5017 * unspecified results."
5019 * echo $(echo '(TEST)' BEST) (TEST) BEST
5020 * echo $(echo 'TEST)' BEST) TEST) BEST
5021 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5023 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5027 int ch = i_getch(input);
5029 syntax_error_unterm_ch(')');
5030 /*xfunc_die(); - redundant */
5038 if (i_peek(input) == ')') {
5046 add_till_single_quote(dest, input);
5051 add_till_double_quote(dest, input);
5056 /* \x. Copy verbatim. Important for \(, \) */
5057 ch = i_getch(input);
5059 syntax_error_unterm_ch(')');
5060 /*xfunc_die(); - redundant */
5067 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5069 /* Return code: 0 for OK, 1 for syntax error */
5071 #define handle_dollar(as_string, dest, input) \
5072 handle_dollar(dest, input)
5074 static int handle_dollar(o_string *as_string,
5076 struct in_str *input)
5079 int ch = i_peek(input); /* first character after the $ */
5080 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5082 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5084 ch = i_getch(input);
5085 nommu_addchr(as_string, ch);
5087 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5089 debug_printf_parse(": '%c'\n", ch);
5090 o_addchr(dest, ch | quote_mask);
5093 if (!isalnum(ch) && ch != '_')
5095 ch = i_getch(input);
5096 nommu_addchr(as_string, ch);
5098 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5099 } else if (isdigit(ch)) {
5101 ch = i_getch(input);
5102 nommu_addchr(as_string, ch);
5103 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5104 debug_printf_parse(": '%c'\n", ch);
5105 o_addchr(dest, ch | quote_mask);
5106 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5107 } else switch (ch) {
5109 case '!': /* last bg pid */
5110 case '?': /* last exit code */
5111 case '#': /* number of args */
5112 case '*': /* args */
5113 case '@': /* args */
5114 goto make_one_char_var;
5116 bool first_char, all_digits;
5118 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5119 ch = i_getch(input);
5120 nommu_addchr(as_string, ch);
5121 /* TODO: maybe someone will try to escape the '}' */
5126 ch = i_getch(input);
5127 nommu_addchr(as_string, ch);
5134 /* ${#var}: length of var contents */
5144 && ( (all_digits && !isdigit(ch))
5145 || (!all_digits && !isalnum(ch) && ch != '_')
5148 /* handle parameter expansions
5149 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5154 case ':': /* null modifier */
5155 if (expansion == 0) {
5156 debug_printf_parse(": null modifier\n");
5161 case '#': /* remove prefix */
5162 case '%': /* remove suffix */
5163 if (expansion == 0) {
5164 debug_printf_parse(": remove suffix/prefix\n");
5169 case '-': /* default value */
5170 case '=': /* assign default */
5171 case '+': /* alternative */
5172 case '?': /* error indicate */
5173 debug_printf_parse(": parameter expansion\n");
5178 syntax_error_unterm_str("${name}");
5179 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5184 debug_printf_parse(": '%c'\n", ch);
5185 o_addchr(dest, ch | quote_mask);
5189 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5192 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5197 ch = i_getch(input);
5198 nommu_addchr(as_string, ch);
5199 # if ENABLE_SH_MATH_SUPPORT
5200 if (i_peek(input) == '(') {
5201 ch = i_getch(input);
5202 nommu_addchr(as_string, ch);
5203 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5204 o_addchr(dest, /*quote_mask |*/ '+');
5208 add_till_closing_paren(dest, input, true);
5211 o_addstr(as_string, dest->data + pos);
5212 o_addchr(as_string, ')');
5213 o_addchr(as_string, ')');
5216 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5220 # if ENABLE_HUSH_TICK
5221 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5222 o_addchr(dest, quote_mask | '`');
5226 add_till_closing_paren(dest, input, false);
5229 o_addstr(as_string, dest->data + pos);
5230 o_addchr(as_string, '`');
5233 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5239 ch = i_getch(input);
5240 nommu_addchr(as_string, ch);
5242 if (isalnum(ch)) { /* it's $_name or $_123 */
5248 /* $_ Shell or shell script name; or last cmd name */
5249 /* $- Option flags set by set builtin or shell options (-i etc) */
5251 o_addQchr(dest, '$');
5253 debug_printf_parse("handle_dollar return 0\n");
5258 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5259 parse_stream_dquoted(dest, input, dquote_end)
5261 static int parse_stream_dquoted(o_string *as_string,
5263 struct in_str *input,
5270 ch = i_getch(input);
5272 nommu_addchr(as_string, ch);
5273 if (ch == dquote_end) { /* may be only '"' or EOF */
5274 if (dest->o_assignment == NOT_ASSIGNMENT)
5275 dest->o_escape ^= 1;
5276 debug_printf_parse("parse_stream_dquoted return 0\n");
5279 /* note: can't move it above ch == dquote_end check! */
5281 syntax_error_unterm_ch('"');
5282 /*xfunc_die(); - redundant */
5286 next = i_peek(input);
5288 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5289 ch, ch, dest->o_escape);
5292 syntax_error("\\<eof>");
5296 * "The backslash retains its special meaning [in "..."]
5297 * only when followed by one of the following characters:
5298 * $, `, ", \, or <newline>. A double quote may be quoted
5299 * within double quotes by preceding it with a backslash.
5301 if (strchr("$`\"\\", next) != NULL) {
5302 o_addqchr(dest, i_getch(input));
5304 o_addqchr(dest, '\\');
5309 if (handle_dollar(as_string, dest, input) != 0) {
5310 debug_printf_parse("parse_stream_dquoted return 1: "
5311 "handle_dollar returned non-0\n");
5316 #if ENABLE_HUSH_TICK
5318 //int pos = dest->length;
5319 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5320 o_addchr(dest, 0x80 | '`');
5321 add_till_backquote(dest, input);
5322 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5323 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5327 o_addQchr(dest, ch);
5329 && (dest->o_assignment == MAYBE_ASSIGNMENT
5330 || dest->o_assignment == WORD_IS_KEYWORD)
5331 && is_well_formed_var_name(dest->data, '=')
5333 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5339 * Scan input until EOF or end_trigger char.
5340 * Return a list of pipes to execute, or NULL on EOF
5341 * or if end_trigger character is met.
5342 * On syntax error, exit is shell is not interactive,
5343 * reset parsing machinery and start parsing anew,
5344 * or return ERR_PTR.
5346 static struct pipe *parse_stream(char **pstring,
5347 struct in_str *input,
5350 struct parse_context ctx;
5351 o_string dest = NULL_O_STRING;
5355 /* Double-quote state is handled in the state variable is_in_dquote.
5356 * A single-quote triggers a bypass of the main loop until its mate is
5357 * found. When recursing, quote state is passed in via dest->o_escape.
5359 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5360 end_trigger ? : 'X');
5363 G.ifs = get_local_var_value("IFS");
5368 #if ENABLE_HUSH_INTERACTIVE
5369 input->promptmode = 0; /* PS1 */
5371 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5372 initialize_context(&ctx);
5377 const char *is_special;
5381 redir_type redir_style;
5384 /* dest.o_quoted = 1; - already is (see below) */
5385 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5388 /* We reached closing '"' */
5391 ch = i_getch(input);
5392 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5393 ch, ch, dest.o_escape);
5398 syntax_error_unterm_str("here document");
5401 if (done_word(&dest, &ctx)) {
5405 done_pipe(&ctx, PIPE_SEQ);
5407 /* If we got nothing... */
5408 /* (this makes bare "&" cmd a no-op.
5409 * bash says: "syntax error near unexpected token '&'") */
5410 if (pi->num_cmds == 0
5411 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5417 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5419 *pstring = ctx.as_string.data;
5421 o_free_unsafe(&ctx.as_string);
5424 debug_printf_parse("parse_stream return %p\n", pi);
5427 nommu_addchr(&ctx.as_string, ch);
5428 is_ifs = strchr(G.ifs, ch);
5429 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5430 "\\$\"" USE_HUSH_TICK("`") /* always special */
5433 if (!is_special && !is_ifs) { /* ordinary char */
5435 o_addQchr(&dest, ch);
5436 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5437 || dest.o_assignment == WORD_IS_KEYWORD)
5439 && is_well_formed_var_name(dest.data, '=')
5441 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5447 if (done_word(&dest, &ctx)) {
5451 #if ENABLE_HUSH_CASE
5452 /* "case ... in <newline> word) ..." -
5453 * newlines are ignored (but ';' wouldn't be) */
5454 if (ctx.command->argv == NULL
5455 && ctx.ctx_res_w == RES_MATCH
5460 /* Treat newline as a command separator. */
5461 done_pipe(&ctx, PIPE_SEQ);
5462 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5464 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5469 dest.o_assignment = MAYBE_ASSIGNMENT;
5471 /* note: if (is_ifs) continue;
5472 * will still trigger for us */
5476 /* "cmd}" or "cmd }..." without semicolon or &:
5477 * } is an ordinary char in this case, even inside { cmd; }
5478 * Pathological example: { ""}; } should exec "}" cmd
5481 if (!IS_NULL_CMD(ctx.command) /* cmd } */
5482 || dest.length != 0 /* word} */
5483 || dest.o_quoted /* ""} */
5487 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5488 goto skip_end_trigger;
5489 /* else: } does terminate a group */
5492 if (end_trigger && end_trigger == ch
5493 && (heredoc_cnt == 0 || end_trigger != ';')
5496 /* This is technically valid:
5497 * { cat <<HERE; }; echo Ok
5501 * but we don't support this.
5502 * We require heredoc to be in enclosing {}/(),
5505 syntax_error_unterm_str("here document");
5508 if (done_word(&dest, &ctx)) {
5511 done_pipe(&ctx, PIPE_SEQ);
5512 dest.o_assignment = MAYBE_ASSIGNMENT;
5513 /* Do we sit outside of any if's, loops or case's? */
5515 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5519 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5521 *pstring = ctx.as_string.data;
5523 o_free_unsafe(&ctx.as_string);
5526 debug_printf_parse("parse_stream return %p: "
5527 "end_trigger char found\n",
5529 return ctx.list_head;
5538 next = i_peek(input);
5541 /* Catch <, > before deciding whether this word is
5542 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5545 redir_fd = redirect_opt_num(&dest);
5546 if (done_word(&dest, &ctx)) {
5549 redir_style = REDIRECT_OVERWRITE;
5551 redir_style = REDIRECT_APPEND;
5552 ch = i_getch(input);
5553 nommu_addchr(&ctx.as_string, ch);
5556 else if (next == '(') {
5557 syntax_error(">(process) not supported");
5561 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5563 continue; /* back to top of while (1) */
5565 redir_fd = redirect_opt_num(&dest);
5566 if (done_word(&dest, &ctx)) {
5569 redir_style = REDIRECT_INPUT;
5571 redir_style = REDIRECT_HEREDOC;
5573 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5574 ch = i_getch(input);
5575 nommu_addchr(&ctx.as_string, ch);
5576 } else if (next == '>') {
5577 redir_style = REDIRECT_IO;
5578 ch = i_getch(input);
5579 nommu_addchr(&ctx.as_string, ch);
5582 else if (next == '(') {
5583 syntax_error("<(process) not supported");
5587 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5589 continue; /* back to top of while (1) */
5592 if (dest.o_assignment == MAYBE_ASSIGNMENT
5593 /* check that we are not in word in "a=1 2>word b=1": */
5594 && !ctx.pending_redirect
5596 /* ch is a special char and thus this word
5597 * cannot be an assignment */
5598 dest.o_assignment = NOT_ASSIGNMENT;
5603 if (dest.length == 0) {
5606 if (ch == EOF || ch == '\n')
5609 /* note: we do not add it to &ctx.as_string */
5611 nommu_addchr(&ctx.as_string, '\n');
5613 o_addQchr(&dest, ch);
5618 syntax_error("\\<eof>");
5621 o_addchr(&dest, '\\');
5622 ch = i_getch(input);
5623 nommu_addchr(&ctx.as_string, ch);
5624 o_addchr(&dest, ch);
5625 /* Example: echo Hello \2>file
5626 * we need to know that word 2 is quoted */
5630 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5631 debug_printf_parse("parse_stream parse error: "
5632 "handle_dollar returned non-0\n");
5639 ch = i_getch(input);
5641 syntax_error_unterm_ch('\'');
5642 /*xfunc_die(); - redundant */
5644 nommu_addchr(&ctx.as_string, ch);
5647 if (dest.o_assignment == NOT_ASSIGNMENT)
5648 o_addqchr(&dest, ch);
5650 o_addchr(&dest, ch);
5655 is_in_dquote ^= 1; /* invert */
5656 if (dest.o_assignment == NOT_ASSIGNMENT)
5659 #if ENABLE_HUSH_TICK
5664 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5665 o_addchr(&dest, '`');
5669 add_till_backquote(&dest, input);
5671 o_addstr(&ctx.as_string, dest.data + pos);
5672 o_addchr(&ctx.as_string, '`');
5674 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5675 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5680 #if ENABLE_HUSH_CASE
5683 if (done_word(&dest, &ctx)) {
5686 done_pipe(&ctx, PIPE_SEQ);
5687 #if ENABLE_HUSH_CASE
5688 /* Eat multiple semicolons, detect
5689 * whether it means something special */
5694 ch = i_getch(input);
5695 nommu_addchr(&ctx.as_string, ch);
5696 if (ctx.ctx_res_w == RES_CASEI) {
5697 ctx.ctx_dsemicolon = 1;
5698 ctx.ctx_res_w = RES_MATCH;
5704 /* We just finished a cmd. New one may start
5705 * with an assignment */
5706 dest.o_assignment = MAYBE_ASSIGNMENT;
5709 if (done_word(&dest, &ctx)) {
5713 ch = i_getch(input);
5714 nommu_addchr(&ctx.as_string, ch);
5715 done_pipe(&ctx, PIPE_AND);
5717 done_pipe(&ctx, PIPE_BG);
5721 if (done_word(&dest, &ctx)) {
5724 #if ENABLE_HUSH_CASE
5725 if (ctx.ctx_res_w == RES_MATCH)
5726 break; /* we are in case's "word | word)" */
5728 if (next == '|') { /* || */
5729 ch = i_getch(input);
5730 nommu_addchr(&ctx.as_string, ch);
5731 done_pipe(&ctx, PIPE_OR);
5733 /* we could pick up a file descriptor choice here
5734 * with redirect_opt_num(), but bash doesn't do it.
5735 * "echo foo 2| cat" yields "foo 2". */
5740 #if ENABLE_HUSH_CASE
5741 /* "case... in [(]word)..." - skip '(' */
5742 if (ctx.ctx_res_w == RES_MATCH
5743 && ctx.command->argv == NULL /* not (word|(... */
5744 && dest.length == 0 /* not word(... */
5745 && dest.o_quoted == 0 /* not ""(... */
5751 if (parse_group(&dest, &ctx, input, ch) != 0) {
5756 #if ENABLE_HUSH_CASE
5757 if (ctx.ctx_res_w == RES_MATCH)
5761 /* proper use of this character is caught by end_trigger:
5762 * if we see {, we call parse_group(..., end_trigger='}')
5763 * and it will match } earlier (not here). */
5764 syntax_error_unexpected_ch(ch);
5768 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5774 struct parse_context *pctx;
5775 IF_HAS_KEYWORDS(struct parse_context *p2;)
5777 /* Clean up allocated tree.
5778 * Samples for finding leaks on syntax error recovery path.
5779 * Run them from interactive shell, watch pmap `pidof hush`.
5780 * while if false; then false; fi do break; done
5782 * while if false; then false; fi; do break; fi
5783 * Samples to catch leaks at execution:
5784 * while if (true | {true;}); then echo ok; fi; do break; done
5785 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5789 /* Update pipe/command counts,
5790 * otherwise freeing may miss some */
5791 done_pipe(pctx, PIPE_SEQ);
5792 debug_printf_clean("freeing list %p from ctx %p\n",
5793 pctx->list_head, pctx);
5794 debug_print_tree(pctx->list_head, 0);
5795 free_pipe_list(pctx->list_head);
5796 debug_printf_clean("freed list %p\n", pctx->list_head);
5798 o_free_unsafe(&pctx->as_string);
5800 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5804 IF_HAS_KEYWORDS(pctx = p2;)
5805 } while (HAS_KEYWORDS && pctx);
5806 /* Free text, clear all dest fields */
5808 /* If we are not in top-level parse, we return,
5809 * our caller will propagate error.
5811 if (end_trigger != ';') {
5819 /* Discard cached input, force prompt */
5821 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5826 /* Executing from string: eval, sh -c '...'
5827 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5828 * end_trigger controls how often we stop parsing
5829 * NUL: parse all, execute, return
5830 * ';': parse till ';' or newline, execute, repeat till EOF
5832 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5835 struct pipe *pipe_list;
5837 pipe_list = parse_stream(NULL, inp, end_trigger);
5838 if (!pipe_list) /* EOF */
5840 debug_print_tree(pipe_list, 0);
5841 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5842 run_and_free_list(pipe_list);
5846 static void parse_and_run_string(const char *s)
5848 struct in_str input;
5849 setup_string_in_str(&input, s);
5850 parse_and_run_stream(&input, '\0');
5853 static void parse_and_run_file(FILE *f)
5855 struct in_str input;
5856 setup_file_in_str(&input, f);
5857 parse_and_run_stream(&input, ';');
5860 /* Called a few times only (or even once if "sh -c") */
5861 static void block_signals(int second_time)
5866 mask = (1 << SIGQUIT);
5867 if (G_interactive_fd)
5868 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5869 G.non_DFL_mask = mask;
5872 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5876 sigaddset(&G.blocked_set, sig);
5880 sigdelset(&G.blocked_set, SIGCHLD);
5882 sigprocmask(SIG_SETMASK, &G.blocked_set,
5883 second_time ? NULL : &G.inherited_set);
5884 /* POSIX allows shell to re-enable SIGCHLD
5885 * even if it was SIG_IGN on entry */
5886 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5888 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5893 static void maybe_set_to_sigexit(int sig)
5895 void (*handler)(int);
5896 /* non_DFL_mask'ed signals are, well, masked,
5897 * no need to set handler for them.
5899 if (!((G.non_DFL_mask >> sig) & 1)) {
5900 handler = signal(sig, sigexit);
5901 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5902 signal(sig, handler);
5905 /* Set handlers to restore tty pgrp and exit */
5906 static void set_fatal_handlers(void)
5908 /* We _must_ restore tty pgrp on fatal signals */
5910 maybe_set_to_sigexit(SIGILL );
5911 maybe_set_to_sigexit(SIGFPE );
5912 maybe_set_to_sigexit(SIGBUS );
5913 maybe_set_to_sigexit(SIGSEGV);
5914 maybe_set_to_sigexit(SIGTRAP);
5915 } /* else: hush is perfect. what SEGV? */
5916 maybe_set_to_sigexit(SIGABRT);
5917 /* bash 3.2 seems to handle these just like 'fatal' ones */
5918 maybe_set_to_sigexit(SIGPIPE);
5919 maybe_set_to_sigexit(SIGALRM);
5920 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
5921 * if we aren't interactive... but in this case
5922 * we never want to restore pgrp on exit, and this fn is not called */
5923 /*maybe_set_to_sigexit(SIGHUP );*/
5924 /*maybe_set_to_sigexit(SIGTERM);*/
5925 /*maybe_set_to_sigexit(SIGINT );*/
5929 static int set_mode(const char cstate, const char mode)
5931 int state = (cstate == '-' ? 1 : 0);
5933 case 'n': G.fake_mode = state; break;
5934 case 'x': /*G.debug_mode = state;*/ break;
5935 default: return EXIT_FAILURE;
5937 return EXIT_SUCCESS;
5940 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5941 int hush_main(int argc, char **argv)
5943 static const struct variable const_shell_ver = {
5945 .varstr = (char*)hush_version_str,
5946 .max_len = 1, /* 0 can provoke free(name) */
5950 int signal_mask_is_inited = 0;
5953 struct variable *cur_var;
5956 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5957 G.last_exitcode = EXIT_SUCCESS;
5959 G.argv0_for_re_execing = argv[0];
5961 /* Deal with HUSH_VERSION */
5962 G.shell_ver = const_shell_ver; /* copying struct here */
5963 G.top_var = &G.shell_ver;
5964 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5965 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5966 /* Initialize our shell local variables with the values
5967 * currently living in the environment */
5968 cur_var = G.top_var;
5971 char *value = strchr(*e, '=');
5972 if (value) { /* paranoia */
5973 cur_var->next = xzalloc(sizeof(*cur_var));
5974 cur_var = cur_var->next;
5975 cur_var->varstr = *e;
5976 cur_var->max_len = strlen(*e);
5977 cur_var->flg_export = 1;
5981 debug_printf_env("putenv '%s'\n", hush_version_str);
5982 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5983 #if ENABLE_FEATURE_EDITING
5984 G.line_input_state = new_line_input_t(FOR_SHELL);
5986 G.global_argc = argc;
5987 G.global_argv = argv;
5988 /* Initialize some more globals to non-zero values */
5990 #if ENABLE_HUSH_INTERACTIVE
5991 if (ENABLE_FEATURE_EDITING)
5992 cmdedit_set_initial_prompt();
5996 if (setjmp(die_jmp)) {
5997 /* xfunc has failed! die die die */
5998 /* no EXIT traps, this is an escape hatch! */
6000 hush_exit(xfunc_error_retval);
6003 /* Shell is non-interactive at first. We need to call
6004 * block_signals(0) if we are going to execute "sh <script>",
6005 * "sh -c <cmds>" or login shell's /etc/profile and friends.
6006 * If we later decide that we are interactive, we run block_signals(0)
6007 * (or re-run block_signals(1) if we ran block_signals(0) before)
6008 * in order to intercept (more) signals.
6012 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
6014 opt = getopt(argc, argv, "c:xins"
6017 # if ENABLE_HUSH_FUNCTIONS
6027 G.root_pid = getpid();
6028 G.global_argv = argv + optind;
6029 if (!argv[optind]) {
6030 /* -c 'script' (no params): prevent empty $0 */
6031 *--G.global_argv = argv[0];
6033 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6034 G.global_argc = argc - optind;
6035 block_signals(0); /* 0: called 1st time */
6036 parse_and_run_string(optarg);
6039 /* Well, we cannot just declare interactiveness,
6040 * we have to have some stuff (ctty, etc) */
6041 /* G_interactive_fd++; */
6044 /* "-s" means "read from stdin", but this is how we always
6045 * operate, so simply do nothing here. */
6048 case '<': /* "big heredoc" support */
6049 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6052 G.root_pid = bb_strtou(optarg, &optarg, 16);
6054 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6056 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6057 # if ENABLE_HUSH_LOOPS
6059 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6064 set_local_var(xstrdup(optarg), 0, opt == 'R');
6066 # if ENABLE_HUSH_FUNCTIONS
6068 struct function *funcp = new_function(optarg);
6069 /* funcp->name is already set to optarg */
6070 /* funcp->body is set to NULL. It's a special case. */
6071 funcp->body_as_string = argv[optind];
6079 if (!set_mode('-', opt))
6083 fprintf(stderr, "Usage: sh [FILE]...\n"
6084 " or: sh -c command [args]...\n\n");
6090 } /* option parsing loop */
6093 G.root_pid = getpid();
6095 /* If we are login shell... */
6096 if (argv[0] && argv[0][0] == '-') {
6098 /* TODO: what should argv be while sourcing /etc/profile? */
6099 debug_printf("sourcing /etc/profile\n");
6100 input = fopen_for_read("/etc/profile");
6101 if (input != NULL) {
6102 close_on_exec_on(fileno(input));
6103 block_signals(0); /* 0: called 1st time */
6104 signal_mask_is_inited = 1;
6105 parse_and_run_file(input);
6108 /* bash: after sourcing /etc/profile,
6109 * tries to source (in the given order):
6110 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6111 * stopping of first found. --noprofile turns this off.
6112 * bash also sources ~/.bash_logout on exit.
6113 * If called as sh, skips .bash_XXX files.
6120 * "bash <script>" (which is never interactive (unless -i?))
6121 * sources $BASH_ENV here (without scanning $PATH).
6122 * If called as sh, does the same but with $ENV.
6124 debug_printf("running script '%s'\n", argv[optind]);
6125 G.global_argv = argv + optind;
6126 G.global_argc = argc - optind;
6127 input = xfopen_for_read(argv[optind]);
6128 close_on_exec_on(fileno(input));
6129 if (!signal_mask_is_inited)
6130 block_signals(0); /* 0: called 1st time */
6131 parse_and_run_file(input);
6132 #if ENABLE_FEATURE_CLEAN_UP
6138 /* Up to here, shell was non-interactive. Now it may become one.
6139 * NB: don't forget to (re)run block_signals(0/1) as needed.
6142 /* A shell is interactive if the '-i' flag was given, or if all of
6143 * the following conditions are met:
6145 * no arguments remaining or the -s flag given
6146 * standard input is a terminal
6147 * standard output is a terminal
6148 * Refer to Posix.2, the description of the 'sh' utility.
6151 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6152 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6153 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6154 //TODO: "interactive" and "have job control" are two different things.
6155 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6156 //should stay on! Currently, we mix these into one.
6157 if (G.saved_tty_pgrp >= 0) {
6158 /* try to dup stdin to high fd#, >= 255 */
6159 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6160 if (G_interactive_fd < 0) {
6161 /* try to dup to any fd */
6162 G_interactive_fd = dup(STDIN_FILENO);
6163 if (G_interactive_fd < 0)
6165 G_interactive_fd = 0;
6167 // TODO: track & disallow any attempts of user
6168 // to (inadvertently) close/redirect it
6171 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6172 if (G_interactive_fd) {
6175 /* We are indeed interactive shell, and we will perform
6176 * job control. Setting up for that. */
6178 close_on_exec_on(G_interactive_fd);
6179 /* If we were run as 'hush &', sleep until we are
6180 * in the foreground (tty pgrp == our pgrp).
6181 * If we get started under a job aware app (like bash),
6182 * make sure we are now in charge so we don't fight over
6183 * who gets the foreground */
6185 shell_pgrp = getpgrp();
6186 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6187 if (G.saved_tty_pgrp == shell_pgrp)
6189 /* send TTIN to ourself (should stop us) */
6190 kill(- shell_pgrp, SIGTTIN);
6192 /* Block some signals */
6193 block_signals(signal_mask_is_inited);
6194 /* Set other signals to restore saved_tty_pgrp */
6195 set_fatal_handlers();
6196 /* Put ourselves in our own process group */
6197 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6198 /* Grab control of the terminal */
6199 tcsetpgrp(G_interactive_fd, getpid());
6200 /* -1 is special - makes xfuncs longjmp, not exit
6201 * (we reset die_sleep = 0 whereever we [v]fork) */
6202 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6203 } else if (!signal_mask_is_inited) {
6204 block_signals(0); /* 0: called 1st time */
6205 } /* else: block_signals(0) was done before */
6206 #elif ENABLE_HUSH_INTERACTIVE
6207 /* No job control compiled in, only prompt/line editing */
6208 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6209 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6210 if (G_interactive_fd < 0) {
6211 /* try to dup to any fd */
6212 G_interactive_fd = dup(STDIN_FILENO);
6213 if (G_interactive_fd < 0)
6215 G_interactive_fd = 0;
6218 if (G_interactive_fd) {
6219 close_on_exec_on(G_interactive_fd);
6220 block_signals(signal_mask_is_inited);
6221 } else if (!signal_mask_is_inited) {
6225 /* We have interactiveness code disabled */
6226 if (!signal_mask_is_inited) {
6231 * if interactive but not a login shell, sources ~/.bashrc
6232 * (--norc turns this off, --rcfile <file> overrides)
6235 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6236 printf("\n\n%s hush - the humble shell\n", bb_banner);
6237 printf("Enter 'help' for a list of built-in commands.\n\n");
6240 parse_and_run_file(stdin);
6243 #if ENABLE_FEATURE_CLEAN_UP
6244 if (G.cwd != bb_msg_unknown)
6246 cur_var = G.top_var->next;
6248 struct variable *tmp = cur_var;
6249 if (!cur_var->max_len)
6250 free(cur_var->varstr);
6251 cur_var = cur_var->next;
6255 hush_exit(G.last_exitcode);
6260 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6261 int lash_main(int argc, char **argv)
6263 //bb_error_msg("lash is deprecated, please use hush instead");
6264 return hush_main(argc, argv);
6272 static int builtin_true(char **argv UNUSED_PARAM)
6277 static int builtin_test(char **argv)
6284 return test_main(argc, argv - argc);
6287 static int builtin_echo(char **argv)
6294 return echo_main(argc, argv - argc);
6297 static int builtin_eval(char **argv)
6299 int rcode = EXIT_SUCCESS;
6302 char *str = expand_strvec_to_string(argv);
6304 * eval "echo Hi; done" ("done" is syntax error):
6305 * "echo Hi" will not execute too.
6307 parse_and_run_string(str);
6309 rcode = G.last_exitcode;
6314 static int builtin_cd(char **argv)
6316 const char *newdir = argv[1];
6317 if (newdir == NULL) {
6318 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6319 * bash says "bash: cd: HOME not set" and does nothing
6322 newdir = getenv("HOME") ? : "/";
6324 if (chdir(newdir)) {
6325 /* Mimic bash message exactly */
6326 bb_perror_msg("cd: %s", newdir);
6327 return EXIT_FAILURE;
6330 return EXIT_SUCCESS;
6333 static int builtin_exec(char **argv)
6335 if (*++argv == NULL)
6336 return EXIT_SUCCESS; /* bash does this */
6341 /* TODO: if exec fails, bash does NOT exit! We do... */
6342 pseudo_exec_argv(&dummy, argv, 0, NULL);
6347 static int builtin_exit(char **argv)
6349 debug_printf_exec("%s()\n", __func__);
6351 /* interactive bash:
6352 * # trap "echo EEE" EXIT
6355 * There are stopped jobs.
6356 * (if there are _stopped_ jobs, running ones don't count)
6359 # EEE (then bash exits)
6361 * we can use G.exiting = -1 as indicator "last cmd was exit"
6364 /* note: EXIT trap is run by hush_exit */
6365 if (*++argv == NULL)
6366 hush_exit(G.last_exitcode);
6367 /* mimic bash: exit 123abc == exit 255 + error msg */
6368 xfunc_error_retval = 255;
6369 /* bash: exit -2 == exit 254, no error msg */
6370 hush_exit(xatoi(*argv) & 0xff);
6373 static void print_escaped(const char *s)
6379 p = strchrnul(s, '\'');
6380 /* print 'xxxx', possibly just '' */
6381 printf("'%.*s'", (int)(p - s), s);
6386 /* s points to '; print "'''...'''" */
6388 do putchar('\''); while (*++s == '\'');
6393 static int builtin_export(char **argv)
6395 if (*++argv == NULL) {
6402 /* ash emits: export VAR='VAL'
6403 * bash: declare -x VAR="VAL"
6404 * we follow ash example */
6405 const char *s = *e++;
6406 const char *p = strchr(s, '=');
6408 if (!p) /* wtf? take next variable */
6411 printf("export %.*s", (int)(p - s) + 1, s);
6412 print_escaped(p + 1);
6416 /*fflush(stdout); - done after each builtin anyway */
6418 return EXIT_SUCCESS;
6424 /* So far we do not check that name is valid */
6425 if (strchr(name, '=') == NULL) {
6426 /* Exporting a name without a =VALUE */
6427 struct variable *var;
6429 var = get_local_var(name);
6431 var->flg_export = 1;
6432 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6433 putenv(var->varstr);
6436 /* Exporting non-existing variable.
6437 * bash does not put it in environment,
6438 * but remembers that it is exported,
6439 * and does put it in env when it is set later.
6440 * We just set it to "" and export. */
6441 name = xasprintf("%s=", name);
6443 /* Exporting VAR=VALUE */
6444 name = xstrdup(name);
6446 set_local_var(name, 1, 0);
6449 return EXIT_SUCCESS;
6452 static int builtin_trap(char **argv)
6458 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6463 /* No args: print all trapped */
6464 for (i = 0; i < NSIG; ++i) {
6467 print_escaped(G.traps[i]);
6468 printf(" %s\n", get_signame(i));
6471 /*fflush(stdout); - done after each builtin anyway */
6472 return EXIT_SUCCESS;
6476 /* If first arg is a number: reset all specified signals */
6477 sig = bb_strtou(*argv, NULL, 10);
6483 sig = get_signum(*argv++);
6484 if (sig < 0 || sig >= NSIG) {
6486 /* Mimic bash message exactly */
6487 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
6492 G.traps[sig] = xstrdup(new_cmd);
6494 debug_printf("trap: setting SIG%s (%i) to '%s'",
6495 get_signame(sig), sig, G.traps[sig]);
6497 /* There is no signal for 0 (EXIT) */
6502 sigaddset(&G.blocked_set, sig);
6504 /* There was a trap handler, we are removing it
6505 * (if sig has non-DFL handling,
6506 * we don't need to do anything) */
6507 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6509 sigdelset(&G.blocked_set, sig);
6512 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6516 if (!argv[1]) { /* no second arg */
6517 bb_error_msg("trap: invalid arguments");
6518 return EXIT_FAILURE;
6521 /* First arg is "-": reset all specified to default */
6522 /* First arg is "--": skip it, the rest is "handler SIGs..." */
6523 /* Everything else: set arg as signal handler
6524 * (includes "" case, which ignores signal) */
6525 if (argv[0][0] == '-') {
6526 if (argv[0][1] == '\0') { /* "-" */
6527 /* new_cmd remains NULL: "reset these sigs" */
6530 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
6533 /* else: "-something", no special meaning */
6538 goto process_sig_list;
6542 /* built-in 'fg' and 'bg' handler */
6543 static int builtin_fg_bg(char **argv)
6548 if (!G_interactive_fd)
6549 return EXIT_FAILURE;
6550 /* If they gave us no args, assume they want the last backgrounded task */
6552 for (pi = G.job_list; pi; pi = pi->next) {
6553 if (pi->jobid == G.last_jobid) {
6557 bb_error_msg("%s: no current job", argv[0]);
6558 return EXIT_FAILURE;
6560 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6561 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6562 return EXIT_FAILURE;
6564 for (pi = G.job_list; pi; pi = pi->next) {
6565 if (pi->jobid == jobnum) {
6569 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6570 return EXIT_FAILURE;
6572 /* TODO: bash prints a string representation
6573 * of job being foregrounded (like "sleep 1 | cat") */
6574 if (argv[0][0] == 'f') {
6575 /* Put the job into the foreground. */
6576 tcsetpgrp(G_interactive_fd, pi->pgrp);
6579 /* Restart the processes in the job */
6580 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6581 for (i = 0; i < pi->num_cmds; i++) {
6582 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6583 pi->cmds[i].is_stopped = 0;
6585 pi->stopped_cmds = 0;
6587 i = kill(- pi->pgrp, SIGCONT);
6589 if (errno == ESRCH) {
6590 delete_finished_bg_job(pi);
6591 return EXIT_SUCCESS;
6593 bb_perror_msg("kill (SIGCONT)");
6596 if (argv[0][0] == 'f') {
6598 return checkjobs_and_fg_shell(pi);
6600 return EXIT_SUCCESS;
6604 #if ENABLE_HUSH_HELP
6605 static int builtin_help(char **argv UNUSED_PARAM)
6607 const struct built_in_command *x;
6610 "Built-in commands:\n"
6611 "------------------\n");
6612 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6613 printf("%s\t%s\n", x->cmd, x->descr);
6616 return EXIT_SUCCESS;
6621 static int builtin_jobs(char **argv UNUSED_PARAM)
6624 const char *status_string;
6626 for (job = G.job_list; job; job = job->next) {
6627 if (job->alive_cmds == job->stopped_cmds)
6628 status_string = "Stopped";
6630 status_string = "Running";
6632 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6634 return EXIT_SUCCESS;
6639 static int builtin_memleak(char **argv UNUSED_PARAM)
6644 /* Crude attempt to find where "free memory" starts,
6645 * sans fragmentation. */
6647 l = (unsigned long)p;
6650 if (l < (unsigned long)p) l = (unsigned long)p;
6653 if (!G.memleak_value)
6654 G.memleak_value = l;
6656 l -= G.memleak_value;
6663 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6668 static int builtin_pwd(char **argv UNUSED_PARAM)
6671 return EXIT_SUCCESS;
6674 static int builtin_read(char **argv)
6677 const char *name = "REPLY";
6681 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6682 * and _after_ that_ it will complain */
6683 if (!is_well_formed_var_name(name, '\0')) {
6684 /* Mimic bash message */
6685 bb_error_msg("read: '%s': not a valid identifier", name);
6690 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6692 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6693 return set_local_var(string, 0, 0);
6696 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6697 * built-in 'set' handler
6699 * set [-abCefhmnuvx] [-o option] [argument...]
6700 * set [+abCefhmnuvx] [+o option] [argument...]
6701 * set -- [argument...]
6704 * Implementations shall support the options in both their hyphen and
6705 * plus-sign forms. These options can also be specified as options to sh.
6707 * Write out all variables and their values: set
6708 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6709 * Turn on the -x and -v options: set -xv
6710 * Unset all positional parameters: set --
6711 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6712 * Set the positional parameters to the expansion of x, even if x expands
6713 * with a leading '-' or '+': set -- $x
6715 * So far, we only support "set -- [argument...]" and some of the short names.
6717 static int builtin_set(char **argv)
6720 char **pp, **g_argv;
6721 char *arg = *++argv;
6725 for (e = G.top_var; e; e = e->next)
6727 return EXIT_SUCCESS;
6731 if (!strcmp(arg, "--")) {
6735 if (arg[0] != '+' && arg[0] != '-')
6737 for (n = 1; arg[n]; ++n)
6738 if (set_mode(arg[0], arg[n]))
6740 } while ((arg = *++argv) != NULL);
6741 /* Now argv[0] is 1st argument */
6744 return EXIT_SUCCESS;
6747 /* NB: G.global_argv[0] ($0) is never freed/changed */
6748 g_argv = G.global_argv;
6749 if (G.global_args_malloced) {
6755 G.global_args_malloced = 1;
6756 pp = xzalloc(sizeof(pp[0]) * 2);
6757 pp[0] = g_argv[0]; /* retain $0 */
6760 /* This realloc's G.global_argv */
6761 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6768 return EXIT_SUCCESS;
6770 /* Nothing known, so abort */
6772 bb_error_msg("set: %s: invalid option", arg);
6773 return EXIT_FAILURE;
6776 static int builtin_shift(char **argv)
6782 if (n >= 0 && n < G.global_argc) {
6783 if (G.global_args_malloced) {
6786 free(G.global_argv[m++]);
6789 memmove(&G.global_argv[1], &G.global_argv[n+1],
6790 G.global_argc * sizeof(G.global_argv[0]));
6791 return EXIT_SUCCESS;
6793 return EXIT_FAILURE;
6796 static int builtin_source(char **argv)
6800 #if ENABLE_HUSH_FUNCTIONS
6804 if (*++argv == NULL)
6805 return EXIT_FAILURE;
6807 // TODO: search through $PATH is missing
6808 input = fopen_or_warn(*argv, "r");
6810 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6811 return EXIT_FAILURE;
6813 close_on_exec_on(fileno(input));
6815 #if ENABLE_HUSH_FUNCTIONS
6816 sv_flg = G.flag_return_in_progress;
6817 /* "we are inside sourced file, ok to use return" */
6818 G.flag_return_in_progress = -1;
6820 save_and_replace_G_args(&sv, argv);
6822 parse_and_run_file(input);
6825 restore_G_args(&sv, argv);
6826 #if ENABLE_HUSH_FUNCTIONS
6827 G.flag_return_in_progress = sv_flg;
6830 return G.last_exitcode;
6833 static int builtin_umask(char **argv)
6840 mode_t old_mask = mask;
6843 rc = bb_parse_mode(argv[1], &mask);
6848 * bash: umask: 'q': invalid symbolic mode operator
6849 * bash: umask: 999: octal number out of range
6851 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
6856 printf("%04o\n", (unsigned) mask);
6857 /* fall through and restore mask which we set to 0 */
6861 return !rc; /* rc != 0 - success */
6864 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6865 static int builtin_unset(char **argv)
6872 return EXIT_SUCCESS;
6875 while ((arg = *argv) != NULL && arg[0] == '-') {
6881 if (var == 0 || var == *arg) {
6885 /* else: unset -vf, which is illegal.
6888 bb_error_msg("unset: %s: invalid option", *argv);
6889 return EXIT_FAILURE;
6898 if (unset_local_var(*argv)) {
6899 /* unset <nonexistent_var> doesn't fail.
6900 * Error is when one tries to unset RO var.
6901 * Message was printed by unset_local_var. */
6905 #if ENABLE_HUSH_FUNCTIONS
6915 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6916 static int builtin_wait(char **argv)
6918 int ret = EXIT_SUCCESS;
6921 if (*++argv == NULL) {
6922 /* Don't care about wait results */
6923 /* Note 1: must wait until there are no more children */
6924 /* Note 2: must be interruptible */
6926 * $ sleep 3 & sleep 6 & wait
6931 * $ sleep 3 & sleep 6 & wait
6935 * ^C <-- after ~4 sec from keyboard
6938 sigaddset(&G.blocked_set, SIGCHLD);
6939 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6942 if (errno == ECHILD)
6944 /* Wait for SIGCHLD or any other signal of interest */
6945 /* sigtimedwait with infinite timeout: */
6946 sig = sigwaitinfo(&G.blocked_set, NULL);
6948 sig = check_and_run_traps(sig);
6949 if (sig && sig != SIGCHLD) { /* see note 2 */
6955 sigdelset(&G.blocked_set, SIGCHLD);
6956 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6960 /* This is probably buggy wrt interruptible-ness */
6962 pid_t pid = bb_strtou(*argv, NULL, 10);
6964 /* mimic bash message */
6965 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6966 return EXIT_FAILURE;
6968 if (waitpid(pid, &status, 0) == pid) {
6969 if (WIFSIGNALED(status))
6970 ret = 128 + WTERMSIG(status);
6971 else if (WIFEXITED(status))
6972 ret = WEXITSTATUS(status);
6976 bb_perror_msg("wait %s", *argv);
6985 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
6986 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
6989 def = bb_strtou(argv[1], NULL, 10);
6990 if (errno || def < def_min || argv[2]) {
6991 bb_error_msg("%s: bad arguments", argv[0]);
6999 #if ENABLE_HUSH_LOOPS
7000 static int builtin_break(char **argv)
7003 if (G.depth_of_loop == 0) {
7004 bb_error_msg("%s: only meaningful in a loop", argv[0]);
7005 return EXIT_SUCCESS; /* bash compat */
7007 G.flag_break_continue++; /* BC_BREAK = 1 */
7009 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
7010 if (depth == UINT_MAX)
7011 G.flag_break_continue = BC_BREAK;
7012 if (G.depth_of_loop < depth)
7013 G.depth_break_continue = G.depth_of_loop;
7015 return EXIT_SUCCESS;
7018 static int builtin_continue(char **argv)
7020 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
7021 return builtin_break(argv);
7025 #if ENABLE_HUSH_FUNCTIONS
7026 static int builtin_return(char **argv)
7030 if (G.flag_return_in_progress != -1) {
7031 bb_error_msg("%s: not in a function or sourced script", argv[0]);
7032 return EXIT_FAILURE; /* bash compat */
7035 G.flag_return_in_progress = 1;
7038 * out of range: wraps around at 256, does not error out
7039 * non-numeric param:
7040 * f() { false; return qwe; }; f; echo $?
7041 * bash: return: qwe: numeric argument required <== we do this
7042 * 255 <== we also do this
7044 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);