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 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2346 overlapping_strcpy((char*)list, list[0]);
2347 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2351 static char **expand_assignments(char **argv, int count)
2355 /* Expand assignments into one string each */
2356 for (i = 0; i < count; i++) {
2357 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2365 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2367 static void reset_traps_to_defaults(void)
2369 /* This function is always called in a child shell
2370 * after fork (not vfork, NOMMU doesn't use this function).
2371 * Child shells are not interactive.
2372 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2373 * Testcase: (while :; do :; done) + ^Z should background.
2374 * Same goes for SIGTERM, SIGHUP, SIGINT.
2379 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2382 /* Stupid. It can be done with *single* &= op, but we can't use
2383 * the fact that G.blocked_set is implemented as a bitmask... */
2384 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2388 sigdelset(&G.blocked_set, sig);
2395 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2396 mask = G.non_DFL_mask;
2397 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2401 G.traps[sig] = NULL;
2402 /* There is no signal for 0 (EXIT) */
2405 /* There was a trap handler, we are removing it.
2406 * But if sig still has non-DFL handling,
2407 * we should not unblock it. */
2410 sigdelset(&G.blocked_set, sig);
2412 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2417 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2418 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2420 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2421 char *heredoc_argv[4];
2422 struct variable *cur;
2423 #if ENABLE_HUSH_FUNCTIONS
2424 struct function *funcp;
2429 if (!g_argv0) { /* heredoc */
2430 argv = heredoc_argv;
2431 argv[0] = (char *) G.argv0_for_re_execing;
2432 argv[1] = (char *) "-<";
2433 argv[2] = (char *) s;
2435 pp = &argv[3]; /* used as pointer to empty environment */
2439 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2440 , (unsigned) G.root_pid
2441 , (unsigned) G.last_bg_pid
2442 , (unsigned) G.last_exitcode
2443 USE_HUSH_LOOPS(, G.depth_of_loop)
2445 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2446 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2449 for (cur = G.top_var; cur; cur = cur->next) {
2450 if (!cur->flg_export || cur->flg_read_only)
2453 #if ENABLE_HUSH_FUNCTIONS
2454 for (funcp = G.top_func; funcp; funcp = funcp->next)
2460 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2461 *pp++ = (char *) G.argv0_for_re_execing;
2463 for (cur = G.top_var; cur; cur = cur->next) {
2464 if (cur->varstr == hush_version_str)
2466 if (cur->flg_read_only) {
2467 *pp++ = (char *) "-R";
2468 *pp++ = cur->varstr;
2469 } else if (!cur->flg_export) {
2470 *pp++ = (char *) "-V";
2471 *pp++ = cur->varstr;
2474 #if ENABLE_HUSH_FUNCTIONS
2475 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2476 *pp++ = (char *) "-F";
2477 *pp++ = funcp->name;
2478 *pp++ = funcp->body_as_string;
2481 /* We can pass activated traps here. Say, -Tnn:trap_string
2483 * However, POSIX says that subshells reset signals with traps
2485 * I tested bash-3.2 and it not only does that with true subshells
2486 * of the form ( list ), but with any forked children shells.
2487 * I set trap "echo W" WINCH; and then tried:
2489 * { echo 1; sleep 20; echo 2; } &
2490 * while true; do echo 1; sleep 20; echo 2; break; done &
2491 * true | { echo 1; sleep 20; echo 2; } | cat
2493 * In all these cases sending SIGWINCH to the child shell
2494 * did not run the trap. If I add trap "echo V" WINCH;
2495 * _inside_ group (just before echo 1), it works.
2497 * I conclude it means we don't need to pass active traps here.
2498 * exec syscall below resets them to SIG_DFL for us.
2500 *pp++ = (char *) "-c";
2505 /* *pp = NULL; - is already there */
2509 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2510 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2511 execve(bb_busybox_exec_path, argv, pp);
2512 /* Fallback. Useful for init=/bin/hush usage etc */
2513 if (argv[0][0] == '/')
2514 execve(argv[0], argv, pp);
2515 xfunc_error_retval = 127;
2516 bb_error_msg_and_die("can't re-execute the shell");
2518 #endif /* !BB_MMU */
2521 static void setup_heredoc(struct redir_struct *redir)
2523 struct fd_pair pair;
2526 /* the _body_ of heredoc (misleading field name) */
2527 const char *heredoc = redir->rd_filename;
2534 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2535 expanded = expand_pseudo_dquoted(heredoc);
2539 len = strlen(heredoc);
2541 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2543 xmove_fd(pair.rd, redir->rd_fd);
2545 /* Try writing without forking. Newer kernels have
2546 * dynamically growing pipes. Must use non-blocking write! */
2549 written = write(pair.wr, heredoc, len);
2560 ndelay_off(pair.wr);
2562 /* Okay, pipe buffer was not big enough */
2563 /* Note: we must not create a stray child (bastard? :)
2564 * for the unsuspecting parent process. Child creates a grandchild
2565 * and exits before parent execs the process which consumes heredoc
2566 * (that exec happens after we return from this function) */
2572 bb_perror_msg_and_die("vfork");
2575 disable_restore_tty_pgrp_on_exit();
2576 pid = BB_MMU ? fork() : vfork();
2578 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2582 close(redir->rd_fd); /* read side of the pipe */
2584 full_write(pair.wr, heredoc, len); /* may loop or block */
2587 /* Delegate blocking writes to another process */
2588 xmove_fd(pair.wr, STDOUT_FILENO);
2589 re_execute_shell(&to_free, heredoc, NULL, NULL);
2593 enable_restore_tty_pgrp_on_exit();
2599 wait(NULL); /* wait till child has died */
2602 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2603 * and stderr if they are redirected. */
2604 static int setup_redirects(struct command *prog, int squirrel[])
2607 struct redir_struct *redir;
2609 for (redir = prog->redirects; redir; redir = redir->next) {
2610 if (redir->rd_type == REDIRECT_HEREDOC2) {
2611 /* rd_fd<<HERE case */
2612 if (squirrel && redir->rd_fd < 3) {
2613 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2615 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2617 debug_printf_parse("set heredoc '%s'\n",
2618 redir->rd_filename);
2619 setup_heredoc(redir);
2623 if (redir->rd_dup == REDIRFD_TO_FILE) {
2624 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2626 if (redir->rd_filename == NULL) {
2627 /* Something went wrong in the parse.
2628 * Pretend it didn't happen */
2629 bb_error_msg("bug in redirect parse");
2632 mode = redir_table[redir->rd_type].mode;
2633 p = expand_string_to_string(redir->rd_filename);
2634 openfd = open_or_warn(p, mode);
2637 /* this could get lost if stderr has been redirected, but
2638 * bash and ash both lose it as well (though zsh doesn't!) */
2639 //what the above comment tries to say?
2643 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2644 openfd = redir->rd_dup;
2647 if (openfd != redir->rd_fd) {
2648 if (squirrel && redir->rd_fd < 3) {
2649 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2651 if (openfd == REDIRFD_CLOSE) {
2652 /* "n>-" means "close me" */
2653 close(redir->rd_fd);
2655 xdup2(openfd, redir->rd_fd);
2656 if (redir->rd_dup == REDIRFD_TO_FILE)
2664 static void restore_redirects(int squirrel[])
2667 for (i = 0; i < 3; i++) {
2670 /* We simply die on error */
2677 static void free_pipe_list(struct pipe *head);
2679 /* Return code is the exit status of the pipe */
2680 static void free_pipe(struct pipe *pi)
2683 struct command *command;
2684 struct redir_struct *r, *rnext;
2687 if (pi->stopped_cmds > 0) /* why? */
2689 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2690 for (i = 0; i < pi->num_cmds; i++) {
2691 command = &pi->cmds[i];
2692 debug_printf_clean(" command %d:\n", i);
2693 if (command->argv) {
2694 for (a = 0, p = command->argv; *p; a++, p++) {
2695 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2697 free_strings(command->argv);
2698 command->argv = NULL;
2700 /* not "else if": on syntax error, we may have both! */
2701 if (command->group) {
2702 debug_printf_clean(" begin group (grp_type:%d)\n",
2704 free_pipe_list(command->group);
2705 debug_printf_clean(" end group\n");
2706 command->group = NULL;
2708 /* else is crucial here.
2709 * If group != NULL, child_func is meaningless */
2710 #if ENABLE_HUSH_FUNCTIONS
2711 else if (command->child_func) {
2712 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2713 command->child_func->parent_cmd = NULL;
2717 free(command->group_as_string);
2718 command->group_as_string = NULL;
2720 for (r = command->redirects; r; r = rnext) {
2721 debug_printf_clean(" redirect %d%s",
2722 r->rd_fd, redir_table[r->rd_type].descrip);
2723 /* guard against the case >$FOO, where foo is unset or blank */
2724 if (r->rd_filename) {
2725 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2726 free(r->rd_filename);
2727 r->rd_filename = NULL;
2729 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2733 command->redirects = NULL;
2735 free(pi->cmds); /* children are an array, they get freed all at once */
2743 static void free_pipe_list(struct pipe *head)
2745 struct pipe *pi, *next;
2747 for (pi = head; pi; pi = next) {
2749 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2752 debug_printf_clean("pipe followup code %d\n", pi->followup);
2754 /*pi->next = NULL;*/
2760 static int run_list(struct pipe *pi);
2762 #define parse_stream(pstring, input, end_trigger) \
2763 parse_stream(input, end_trigger)
2765 static struct pipe *parse_stream(char **pstring,
2766 struct in_str *input,
2768 static void parse_and_run_string(const char *s);
2771 static const struct built_in_command* find_builtin(const char *name)
2773 const struct built_in_command *x;
2774 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2775 if (strcmp(name, x->cmd) != 0)
2777 debug_printf_exec("found builtin '%s'\n", name);
2783 #if ENABLE_HUSH_FUNCTIONS
2784 static const struct function *find_function(const char *name)
2786 const struct function *funcp = G.top_func;
2788 if (strcmp(name, funcp->name) == 0) {
2791 funcp = funcp->next;
2794 debug_printf_exec("found function '%s'\n", name);
2798 /* Note: takes ownership on name ptr */
2799 static struct function *new_function(char *name)
2801 struct function *funcp;
2802 struct function **funcpp = &G.top_func;
2804 while ((funcp = *funcpp) != NULL) {
2805 struct command *cmd;
2807 if (strcmp(funcp->name, name) != 0) {
2808 funcpp = &funcp->next;
2812 cmd = funcp->parent_cmd;
2813 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2815 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2817 /* Note: if !funcp->body, do not free body_as_string!
2818 * This is a special case of "-F name body" function:
2819 * body_as_string was not malloced! */
2821 free_pipe_list(funcp->body);
2823 free(funcp->body_as_string);
2827 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2828 cmd->argv[0] = funcp->name;
2829 cmd->group = funcp->body;
2831 cmd->group_as_string = funcp->body_as_string;
2836 debug_printf_exec("remembering new function '%s'\n", name);
2837 funcp = *funcpp = xzalloc(sizeof(*funcp));
2838 /*funcp->next = NULL;*/
2844 static void unset_func(const char *name)
2846 struct function *funcp;
2847 struct function **funcpp = &G.top_func;
2849 while ((funcp = *funcpp) != NULL) {
2850 if (strcmp(funcp->name, name) == 0) {
2851 *funcpp = funcp->next;
2852 /* funcp is unlinked now, deleting it */
2854 /* Note: if !funcp->body, do not free body_as_string!
2855 * This is a special case of "-F name body" function:
2856 * body_as_string was not malloced! */
2858 free_pipe_list(funcp->body);
2860 free(funcp->body_as_string);
2866 funcpp = &funcp->next;
2871 #define exec_function(nommu_save, funcp, argv) \
2872 exec_function(funcp, argv)
2874 static void exec_function(nommu_save_t *nommu_save,
2875 const struct function *funcp,
2876 char **argv) NORETURN;
2877 static void exec_function(nommu_save_t *nommu_save,
2878 const struct function *funcp,
2884 argv[0] = G.global_argv[0];
2885 G.global_argv = argv;
2889 /* On MMU, funcp->body is always non-NULL */
2890 n = run_list(funcp->body);
2894 re_execute_shell(&nommu_save->argv_from_re_execing,
2895 funcp->body_as_string,
2901 static int run_function(const struct function *funcp, char **argv)
2907 save_and_replace_G_args(&sv, argv);
2908 /* "we are in function, ok to use return" */
2909 sv_flg = G.flag_return_in_progress;
2910 G.flag_return_in_progress = -1;
2912 /* On MMU, funcp->body is always non-NULL */
2915 /* Function defined by -F */
2916 parse_and_run_string(funcp->body_as_string);
2917 rc = G.last_exitcode;
2921 rc = run_list(funcp->body);
2924 G.flag_return_in_progress = sv_flg;
2925 restore_G_args(&sv, argv);
2933 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2934 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2935 #define pseudo_exec(nommu_save, command, argv_expanded) \
2936 pseudo_exec(command, argv_expanded)
2939 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2941 * Don't exit() here. If you don't exec, use _exit instead.
2942 * The at_exit handlers apparently confuse the calling process,
2943 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2944 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2945 char **argv, int assignment_cnt,
2946 char **argv_expanded) NORETURN;
2947 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2948 char **argv, int assignment_cnt,
2949 char **argv_expanded)
2953 /* Case when we are here: ... | var=val | ... */
2954 if (!argv[assignment_cnt])
2955 _exit(EXIT_SUCCESS);
2957 new_env = expand_assignments(argv, assignment_cnt);
2959 putenv_all(new_env);
2960 free(new_env); /* optional */
2962 nommu_save->new_env = new_env;
2963 nommu_save->old_env = putenv_all_and_save_old(new_env);
2965 if (argv_expanded) {
2966 argv = argv_expanded;
2968 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2970 nommu_save->argv = argv;
2974 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2975 if (strchr(argv[0], '/') != NULL)
2979 /* On NOMMU, we must never block!
2980 * Example: { sleep 99999 | read line } & echo Ok
2981 * read builtin will block on read syscall, leaving parent blocked
2982 * in vfork. Therefore we can't do this:
2985 /* Check if the command matches any of the builtins.
2986 * Depending on context, this might be redundant. But it's
2987 * easier to waste a few CPU cycles than it is to figure out
2988 * if this is one of those cases.
2992 const struct built_in_command *x = find_builtin(argv[0]);
2994 rcode = x->function(argv);
3000 #if ENABLE_HUSH_FUNCTIONS
3001 /* Check if the command matches any functions */
3003 const struct function *funcp = find_function(argv[0]);
3005 exec_function(nommu_save, funcp, argv);
3010 #if ENABLE_FEATURE_SH_STANDALONE
3011 /* Check if the command matches any busybox applets */
3013 int a = find_applet_by_name(argv[0]);
3015 # if BB_MMU /* see above why on NOMMU it is not allowed */
3016 if (APPLET_IS_NOEXEC(a)) {
3017 debug_printf_exec("running applet '%s'\n", argv[0]);
3018 run_applet_no_and_exit(a, argv);
3021 /* Re-exec ourselves */
3022 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
3023 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3024 execv(bb_busybox_exec_path, argv);
3025 /* If they called chroot or otherwise made the binary no longer
3026 * executable, fall through */
3031 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
3034 debug_printf_exec("execing '%s'\n", argv[0]);
3035 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
3036 execvp(argv[0], argv);
3037 bb_perror_msg("can't exec '%s'", argv[0]);
3038 _exit(EXIT_FAILURE);
3041 /* Called after [v]fork() in run_pipe
3043 static void pseudo_exec(nommu_save_t *nommu_save,
3044 struct command *command,
3045 char **argv_expanded) NORETURN;
3046 static void pseudo_exec(nommu_save_t *nommu_save,
3047 struct command *command,
3048 char **argv_expanded)
3050 if (command->argv) {
3051 pseudo_exec_argv(nommu_save, command->argv,
3052 command->assignment_cnt, argv_expanded);
3055 if (command->group) {
3056 /* Cases when we are here:
3059 * ... | ( list ) | ...
3060 * ... | { list } | ...
3064 debug_printf_exec("pseudo_exec: run_list\n");
3065 reset_traps_to_defaults();
3066 rcode = run_list(command->group);
3067 /* OK to leak memory by not calling free_pipe_list,
3068 * since this process is about to exit */
3071 re_execute_shell(&nommu_save->argv_from_re_execing,
3072 command->group_as_string,
3078 /* Case when we are here: ... | >file */
3079 debug_printf_exec("pseudo_exec'ed null command\n");
3080 _exit(EXIT_SUCCESS);
3084 static const char *get_cmdtext(struct pipe *pi)
3090 /* This is subtle. ->cmdtext is created only on first backgrounding.
3091 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3092 * On subsequent bg argv is trashed, but we won't use it */
3095 argv = pi->cmds[0].argv;
3096 if (!argv || !argv[0]) {
3097 pi->cmdtext = xzalloc(1);
3103 len += strlen(*argv) + 1;
3106 pi->cmdtext = p;// = xmalloc(len);
3107 argv = pi->cmds[0].argv;
3109 len = strlen(*argv);
3110 memcpy(p, *argv, len);
3118 static void insert_bg_job(struct pipe *pi)
3120 struct pipe *job, **jobp;
3123 /* Linear search for the ID of the job to use */
3125 for (job = G.job_list; job; job = job->next)
3126 if (job->jobid >= pi->jobid)
3127 pi->jobid = job->jobid + 1;
3129 /* Add job to the list of running jobs */
3131 while ((job = *jobp) != NULL)
3133 job = *jobp = xmalloc(sizeof(*job));
3135 *job = *pi; /* physical copy */
3137 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3138 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
3139 for (i = 0; i < pi->num_cmds; i++) {
3140 job->cmds[i].pid = pi->cmds[i].pid;
3141 /* all other fields are not used and stay zero */
3143 job->cmdtext = xstrdup(get_cmdtext(pi));
3145 if (G_interactive_fd)
3146 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
3147 /* Last command's pid goes to $! */
3148 G.last_bg_pid = job->cmds[job->num_cmds - 1].pid;
3149 G.last_jobid = job->jobid;
3152 static void remove_bg_job(struct pipe *pi)
3154 struct pipe *prev_pipe;
3156 if (pi == G.job_list) {
3157 G.job_list = pi->next;
3159 prev_pipe = G.job_list;
3160 while (prev_pipe->next != pi)
3161 prev_pipe = prev_pipe->next;
3162 prev_pipe->next = pi->next;
3165 G.last_jobid = G.job_list->jobid;
3170 /* Remove a backgrounded job */
3171 static void delete_finished_bg_job(struct pipe *pi)
3174 pi->stopped_cmds = 0;
3180 /* Check to see if any processes have exited -- if they
3181 * have, figure out why and see if a job has completed */
3182 static int checkjobs(struct pipe* fg_pipe)
3192 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3195 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3196 // /* avoid doing syscall, nothing there anyway */
3199 attributes = WUNTRACED;
3200 if (fg_pipe == NULL)
3201 attributes |= WNOHANG;
3203 /* Do we do this right?
3204 * bash-3.00# sleep 20 | false
3206 * [3]+ Stopped sleep 20 | false
3207 * bash-3.00# echo $?
3208 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3209 * [hush 1.14.0: yes we do it right]
3216 // i = G.count_SIGCHLD;
3217 childpid = waitpid(-1, &status, attributes);
3218 if (childpid <= 0) {
3219 if (childpid && errno != ECHILD)
3220 bb_perror_msg("waitpid");
3221 // else /* Until next SIGCHLD, waitpid's are useless */
3222 // G.handled_SIGCHLD = i;
3225 dead = WIFEXITED(status) || WIFSIGNALED(status);
3228 if (WIFSTOPPED(status))
3229 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3230 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3231 if (WIFSIGNALED(status))
3232 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3233 childpid, WTERMSIG(status), WEXITSTATUS(status));
3234 if (WIFEXITED(status))
3235 debug_printf_jobs("pid %d exited, exitcode %d\n",
3236 childpid, WEXITSTATUS(status));
3238 /* Were we asked to wait for fg pipe? */
3240 for (i = 0; i < fg_pipe->num_cmds; i++) {
3241 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3242 if (fg_pipe->cmds[i].pid != childpid)
3245 fg_pipe->cmds[i].pid = 0;
3246 fg_pipe->alive_cmds--;
3247 if (i == fg_pipe->num_cmds - 1) {
3248 /* last process gives overall exitstatus */
3249 rcode = WEXITSTATUS(status);
3250 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3251 /* bash prints killing signal's name for *last*
3252 * process in pipe (prints just newline for SIGINT).
3253 * we just print newline for any sig:
3255 if (WIFSIGNALED(status)) {
3260 fg_pipe->cmds[i].is_stopped = 1;
3261 fg_pipe->stopped_cmds++;
3263 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3264 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3265 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3266 /* All processes in fg pipe have exited or stopped */
3267 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3268 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3269 * and "killall -STOP cat" */
3270 if (G_interactive_fd) {
3272 if (fg_pipe->alive_cmds)
3273 insert_bg_job(fg_pipe);
3278 /* There are still running processes in the fg pipe */
3279 goto wait_more; /* do waitpid again */
3281 /* it wasnt fg_pipe, look for process in bg pipes */
3285 /* We asked to wait for bg or orphaned children */
3286 /* No need to remember exitcode in this case */
3287 for (pi = G.job_list; pi; pi = pi->next) {
3288 for (i = 0; i < pi->num_cmds; i++) {
3289 if (pi->cmds[i].pid == childpid)
3290 goto found_pi_and_prognum;
3293 /* Happens when shell is used as init process (init=/bin/sh) */
3294 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3295 continue; /* do waitpid again */
3297 found_pi_and_prognum:
3300 pi->cmds[i].pid = 0;
3302 if (!pi->alive_cmds) {
3303 if (G_interactive_fd)
3304 printf(JOB_STATUS_FORMAT, pi->jobid,
3305 "Done", pi->cmdtext);
3306 delete_finished_bg_job(pi);
3310 pi->cmds[i].is_stopped = 1;
3314 } /* while (waitpid succeeds)... */
3320 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3323 int rcode = checkjobs(fg_pipe);
3324 /* Job finished, move the shell to the foreground */
3325 p = getpgid(0); /* pgid of our process */
3326 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3327 tcsetpgrp(G_interactive_fd, p);
3332 /* Start all the jobs, but don't wait for anything to finish.
3335 * Return code is normally -1, when the caller has to wait for children
3336 * to finish to determine the exit status of the pipe. If the pipe
3337 * is a simple builtin command, however, the action is done by the
3338 * time run_pipe returns, and the exit code is provided as the
3341 * Returns -1 only if started some children. IOW: we have to
3342 * mask out retvals of builtins etc with 0xff!
3344 * The only case when we do not need to [v]fork is when the pipe
3345 * is single, non-backgrounded, non-subshell command. Examples:
3346 * cmd ; ... { list } ; ...
3347 * cmd && ... { list } && ...
3348 * cmd || ... { list } || ...
3349 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3350 * or (if SH_STANDALONE) an applet, and we can run the { list }
3351 * with run_list. If it isn't one of these, we fork and exec cmd.
3353 * Cases when we must fork:
3354 * non-single: cmd | cmd
3355 * backgrounded: cmd & { list } &
3356 * subshell: ( list ) [&]
3358 static int run_pipe(struct pipe *pi)
3360 static const char *const null_ptr = NULL;
3363 int pipefds[2]; /* pipefds[0] is for reading */
3364 struct command *command;
3365 char **argv_expanded;
3368 /* it is not always needed, but we aim to smaller code */
3369 int squirrel[] = { -1, -1, -1 };
3372 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3375 USE_HUSH_JOB(pi->pgrp = -1;)
3376 pi->stopped_cmds = 0;
3377 command = &(pi->cmds[0]);
3378 argv_expanded = NULL;
3380 if (pi->num_cmds != 1
3381 || pi->followup == PIPE_BG
3382 || command->grp_type == GRP_SUBSHELL
3389 debug_printf_exec(": group:%p argv:'%s'\n",
3390 command->group, command->argv ? command->argv[0] : "NONE");
3392 if (command->group) {
3393 #if ENABLE_HUSH_FUNCTIONS
3394 if (command->grp_type == GRP_FUNCTION) {
3395 /* "executing" func () { list } */
3396 struct function *funcp;
3398 funcp = new_function(command->argv[0]);
3399 /* funcp->name is already set to argv[0] */
3400 funcp->body = command->group;
3402 funcp->body_as_string = command->group_as_string;
3403 command->group_as_string = NULL;
3405 command->group = NULL;
3406 command->argv[0] = NULL;
3407 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3408 funcp->parent_cmd = command;
3409 command->child_func = funcp;
3411 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3413 return EXIT_SUCCESS;
3417 debug_printf("non-subshell group\n");
3418 rcode = 1; /* exitcode if redir failed */
3419 if (setup_redirects(command, squirrel) == 0) {
3420 debug_printf_exec(": run_list\n");
3421 rcode = run_list(command->group) & 0xff;
3423 restore_redirects(squirrel);
3424 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3426 debug_printf_exec("run_pipe: return %d\n", rcode);
3430 argv = command->argv ? command->argv : (char **) &null_ptr;
3432 const struct built_in_command *x;
3433 #if ENABLE_HUSH_FUNCTIONS
3434 const struct function *funcp;
3438 char **new_env = NULL;
3439 char **old_env = NULL;
3441 if (argv[command->assignment_cnt] == NULL) {
3442 /* Assignments, but no command */
3443 /* Ensure redirects take effect. Try "a=t >file" */
3444 rcode = setup_redirects(command, squirrel);
3445 restore_redirects(squirrel);
3446 /* Set shell variables */
3448 p = expand_string_to_string(*argv);
3449 debug_printf_exec("set shell var:'%s'->'%s'\n",
3451 set_local_var(p, 0, 0);
3454 /* Do we need to flag set_local_var() errors?
3455 * "assignment to readonly var" and "putenv error"
3457 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3459 debug_printf_exec("run_pipe: return %d\n", rcode);
3463 /* Expand the rest into (possibly) many strings each */
3464 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3466 x = find_builtin(argv_expanded[0]);
3467 #if ENABLE_HUSH_FUNCTIONS
3470 funcp = find_function(argv_expanded[0]);
3474 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3475 debug_printf("exec with redirects only\n");
3476 rcode = setup_redirects(command, NULL);
3477 goto clean_up_and_ret1;
3480 /* setup_redirects acts on file descriptors, not FILEs.
3481 * This is perfect for work that comes after exec().
3482 * Is it really safe for inline use? Experimentally,
3483 * things seem to work. */
3484 rcode = setup_redirects(command, squirrel);
3486 new_env = expand_assignments(argv, command->assignment_cnt);
3487 old_env = putenv_all_and_save_old(new_env);
3489 debug_printf_exec(": builtin '%s' '%s'...\n",
3490 x->cmd, argv_expanded[1]);
3491 rcode = x->function(argv_expanded) & 0xff;
3493 #if ENABLE_HUSH_FUNCTIONS
3495 debug_printf_exec(": function '%s' '%s'...\n",
3496 funcp->name, argv_expanded[1]);
3497 rcode = run_function(funcp, argv_expanded) & 0xff;
3501 #if ENABLE_FEATURE_SH_STANDALONE
3504 restore_redirects(squirrel);
3505 free_strings_and_unsetenv(new_env, 1);
3506 putenv_all(old_env);
3507 /* Free the pointers, but the strings themselves
3508 * are in environ now, don't use free_strings! */
3511 free(argv_expanded);
3512 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3514 debug_printf_exec("run_pipe return %d\n", rcode);
3518 #if ENABLE_FEATURE_SH_STANDALONE
3519 i = find_applet_by_name(argv_expanded[0]);
3520 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3521 rcode = setup_redirects(command, squirrel);
3523 new_env = expand_assignments(argv, command->assignment_cnt);
3524 old_env = putenv_all_and_save_old(new_env);
3525 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3526 argv_expanded[0], argv_expanded[1]);
3527 rcode = run_nofork_applet(i, argv_expanded);
3529 goto clean_up_and_ret;
3532 /* It is neither builtin nor applet. We must fork. */
3536 /* NB: argv_expanded may already be created, and that
3537 * might include `cmd` runs! Do not rerun it! We *must*
3538 * use argv_expanded if it's non-NULL */
3540 /* Going to fork a child per each pipe member */
3544 for (i = 0; i < pi->num_cmds; i++) {
3546 volatile nommu_save_t nommu_save;
3547 nommu_save.new_env = NULL;
3548 nommu_save.old_env = NULL;
3549 nommu_save.argv = NULL;
3550 nommu_save.argv_from_re_execing = NULL;
3552 command = &(pi->cmds[i]);
3553 if (command->argv) {
3554 debug_printf_exec(": pipe member '%s' '%s'...\n",
3555 command->argv[0], command->argv[1]);
3557 debug_printf_exec(": pipe member with no argv\n");
3560 /* pipes are inserted between pairs of commands */
3563 if ((i + 1) < pi->num_cmds)
3566 command->pid = BB_MMU ? fork() : vfork();
3567 if (!command->pid) { /* child */
3569 disable_restore_tty_pgrp_on_exit();
3571 /* Every child adds itself to new process group
3572 * with pgid == pid_of_first_child_in_pipe */
3573 if (G.run_list_level == 1 && G_interactive_fd) {
3576 if (pgrp < 0) /* true for 1st process only */
3578 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3579 /* We do it in *every* child, not just first,
3581 tcsetpgrp(G_interactive_fd, pgrp);
3585 xmove_fd(nextin, 0);
3586 xmove_fd(pipefds[1], 1); /* write end */
3588 close(pipefds[0]); /* read end */
3589 /* Like bash, explicit redirects override pipes,
3590 * and the pipe fd is available for dup'ing. */
3591 if (setup_redirects(command, NULL))
3594 /* Restore default handlers just prior to exec */
3595 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3597 /* Stores to nommu_save list of env vars putenv'ed
3598 * (NOMMU, on MMU we don't need that) */
3599 /* cast away volatility... */
3600 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3601 /* pseudo_exec() does not return */
3604 /* parent or error */
3605 enable_restore_tty_pgrp_on_exit();
3607 /* Clean up after vforked child */
3608 free(nommu_save.argv);
3609 free(nommu_save.argv_from_re_execing);
3610 free_strings_and_unsetenv(nommu_save.new_env, 1);
3611 putenv_all(nommu_save.old_env);
3612 /* Free the pointers, but the strings themselves
3613 * are in environ now, don't use free_strings! */
3614 free(nommu_save.old_env);
3616 free(argv_expanded);
3617 argv_expanded = NULL;
3618 if (command->pid < 0) { /* [v]fork failed */
3619 /* Clearly indicate, was it fork or vfork */
3620 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3624 /* Second and next children need to know pid of first one */
3626 pi->pgrp = command->pid;
3632 if ((i + 1) < pi->num_cmds)
3633 close(pipefds[1]); /* write end */
3634 /* Pass read (output) pipe end to next iteration */
3635 nextin = pipefds[0];
3638 if (!pi->alive_cmds) {
3640 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3645 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3649 #ifndef debug_print_tree
3650 static void debug_print_tree(struct pipe *pi, int lvl)
3652 static const char *const PIPE[] = {
3658 static const char *RES[] = {
3659 [RES_NONE ] = "NONE" ,
3662 [RES_THEN ] = "THEN" ,
3663 [RES_ELIF ] = "ELIF" ,
3664 [RES_ELSE ] = "ELSE" ,
3667 #if ENABLE_HUSH_LOOPS
3668 [RES_FOR ] = "FOR" ,
3669 [RES_WHILE] = "WHILE",
3670 [RES_UNTIL] = "UNTIL",
3672 [RES_DONE ] = "DONE" ,
3674 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3677 #if ENABLE_HUSH_CASE
3678 [RES_CASE ] = "CASE" ,
3679 [RES_MATCH] = "MATCH",
3680 [RES_CASEI] = "CASEI",
3681 [RES_ESAC ] = "ESAC" ,
3683 [RES_XXXX ] = "XXXX" ,
3684 [RES_SNTX ] = "SNTX" ,
3686 static const char *const GRPTYPE[] = {
3689 #if ENABLE_HUSH_FUNCTIONS
3698 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3699 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3701 while (prn < pi->num_cmds) {
3702 struct command *command = &pi->cmds[prn];
3703 char **argv = command->argv;
3705 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3707 command->assignment_cnt);
3708 if (command->group) {
3709 fprintf(stderr, " group %s: (argv=%p)\n",
3710 GRPTYPE[command->grp_type],
3712 debug_print_tree(command->group, lvl+1);
3716 if (argv) while (*argv) {
3717 fprintf(stderr, " '%s'", *argv);
3720 fprintf(stderr, "\n");
3729 /* NB: called by pseudo_exec, and therefore must not modify any
3730 * global data until exec/_exit (we can be a child after vfork!) */
3731 static int run_list(struct pipe *pi)
3733 #if ENABLE_HUSH_CASE
3734 char *case_word = NULL;
3736 #if ENABLE_HUSH_LOOPS
3737 struct pipe *loop_top = NULL;
3738 char *for_varname = NULL;
3739 char **for_lcur = NULL;
3740 char **for_list = NULL;
3742 smallint last_followup;
3744 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3745 smalluint cond_code = 0;
3747 enum { cond_code = 0 };
3750 smallint rword; /* enum reserved_style */
3751 smallint last_rword; /* ditto */
3754 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3757 #if ENABLE_HUSH_LOOPS
3758 /* Check syntax for "for" */
3759 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3760 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3762 /* current word is FOR or IN (BOLD in comments below) */
3763 if (cpipe->next == NULL) {
3764 syntax_error("malformed for");
3766 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3769 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3770 if (cpipe->next->res_word == RES_DO)
3772 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3773 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3774 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3776 syntax_error("malformed for");
3778 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3784 /* Past this point, all code paths should jump to ret: label
3785 * in order to return, no direct "return" statements please.
3786 * This helps to ensure that no memory is leaked. */
3794 last_rword = RES_XXXX;
3796 last_followup = PIPE_SEQ;
3797 rcode = G.last_exitcode;
3799 /* Go through list of pipes, (maybe) executing them. */
3800 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3804 IF_HAS_KEYWORDS(rword = pi->res_word;)
3805 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3806 rword, cond_code, last_rword);
3807 #if ENABLE_HUSH_LOOPS
3808 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3809 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3811 /* start of a loop: remember where loop starts */
3816 /* Still in the same "if...", "then..." or "do..." branch? */
3817 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3818 if ((rcode == 0 && last_followup == PIPE_OR)
3819 || (rcode != 0 && last_followup == PIPE_AND)
3821 /* It is "<true> || CMD" or "<false> && CMD"
3822 * and we should not execute CMD */
3823 debug_printf_exec("skipped cmd because of || or &&\n");
3824 last_followup = pi->followup;
3828 last_followup = pi->followup;
3829 IF_HAS_KEYWORDS(last_rword = rword;)
3832 if (rword == RES_THEN) {
3833 /* if false; then ... fi has exitcode 0! */
3834 G.last_exitcode = rcode = EXIT_SUCCESS;
3835 /* "if <false> THEN cmd": skip cmd */
3839 if (rword == RES_ELSE || rword == RES_ELIF) {
3840 /* "if <true> then ... ELSE/ELIF cmd":
3841 * skip cmd and all following ones */
3846 #if ENABLE_HUSH_LOOPS
3847 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3849 /* first loop through for */
3851 static const char encoded_dollar_at[] ALIGN1 = {
3852 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3853 }; /* encoded representation of "$@" */
3854 static const char *const encoded_dollar_at_argv[] = {
3855 encoded_dollar_at, NULL
3856 }; /* argv list with one element: "$@" */
3859 vals = (char**)encoded_dollar_at_argv;
3860 if (pi->next->res_word == RES_IN) {
3861 /* if no variable values after "in" we skip "for" */
3862 if (!pi->next->cmds[0].argv) {
3863 G.last_exitcode = rcode = EXIT_SUCCESS;
3864 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3867 vals = pi->next->cmds[0].argv;
3868 } /* else: "for var; do..." -> assume "$@" list */
3869 /* create list of variable values */
3870 debug_print_strings("for_list made from", vals);
3871 for_list = expand_strvec_to_strvec(vals);
3872 for_lcur = for_list;
3873 debug_print_strings("for_list", for_list);
3874 for_varname = pi->cmds[0].argv[0];
3875 pi->cmds[0].argv[0] = NULL;
3877 free(pi->cmds[0].argv[0]);
3879 /* "for" loop is over, clean up */
3883 pi->cmds[0].argv[0] = for_varname;
3886 /* Insert next value from for_lcur */
3887 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3888 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3889 pi->cmds[0].assignment_cnt = 1;
3891 if (rword == RES_IN) {
3892 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3894 if (rword == RES_DONE) {
3895 continue; /* "done" has no cmds too */
3898 #if ENABLE_HUSH_CASE
3899 if (rword == RES_CASE) {
3900 case_word = expand_strvec_to_string(pi->cmds->argv);
3903 if (rword == RES_MATCH) {
3906 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3908 /* all prev words didn't match, does this one match? */
3909 argv = pi->cmds->argv;
3911 char *pattern = expand_string_to_string(*argv);
3912 /* TODO: which FNM_xxx flags to use? */
3913 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3915 if (cond_code == 0) { /* match! we will execute this branch */
3916 free(case_word); /* make future "word)" stop */
3924 if (rword == RES_CASEI) { /* inside of a case branch */
3926 continue; /* not matched yet, skip this pipe */
3929 /* Just pressing <enter> in shell should check for jobs.
3930 * OTOH, in non-interactive shell this is useless
3931 * and only leads to extra job checks */
3932 if (pi->num_cmds == 0) {
3933 if (G_interactive_fd)
3934 goto check_jobs_and_continue;
3938 /* After analyzing all keywords and conditions, we decided
3939 * to execute this pipe. NB: have to do checkjobs(NULL)
3940 * after run_pipe to collect any background children,
3941 * even if list execution is to be stopped. */
3942 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3945 #if ENABLE_HUSH_LOOPS
3946 G.flag_break_continue = 0;
3948 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3950 /* We ran a builtin, function, or group.
3951 * rcode is already known
3952 * and we don't need to wait for anything. */
3953 G.last_exitcode = rcode;
3954 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3955 check_and_run_traps(0);
3956 #if ENABLE_HUSH_LOOPS
3957 /* Was it "break" or "continue"? */
3958 if (G.flag_break_continue) {
3959 smallint fbc = G.flag_break_continue;
3960 /* We might fall into outer *loop*,
3961 * don't want to break it too */
3963 G.depth_break_continue--;
3964 if (G.depth_break_continue == 0)
3965 G.flag_break_continue = 0;
3966 /* else: e.g. "continue 2" should *break* once, *then* continue */
3967 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3968 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3969 goto check_jobs_and_break;
3970 /* "continue": simulate end of loop */
3975 #if ENABLE_HUSH_FUNCTIONS
3976 if (G.flag_return_in_progress == 1)
3977 goto check_jobs_and_break;
3979 } else if (pi->followup == PIPE_BG) {
3980 /* What does bash do with attempts to background builtins? */
3981 /* even bash 3.2 doesn't do that well with nested bg:
3982 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3983 * I'm NOT treating inner &'s as jobs */
3984 check_and_run_traps(0);
3986 if (G.run_list_level == 1)
3988 debug_printf_exec("insert_bg_job1\n");
3990 debug_printf_exec("insert_bg_job2\n");
3993 G.last_exitcode = rcode = EXIT_SUCCESS;
3994 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3997 if (G.run_list_level == 1 && G_interactive_fd) {
3998 /* Waits for completion, then fg's main shell */
3999 rcode = checkjobs_and_fg_shell(pi);
4000 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
4001 check_and_run_traps(0);
4004 { /* This one just waits for completion */
4005 rcode = checkjobs(pi);
4006 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
4007 check_and_run_traps(0);
4009 G.last_exitcode = rcode;
4013 /* Analyze how result affects subsequent commands */
4015 if (rword == RES_IF || rword == RES_ELIF)
4018 #if ENABLE_HUSH_LOOPS
4019 /* Beware of "while false; true; do ..."! */
4020 if (pi->next && pi->next->res_word == RES_DO) {
4021 if (rword == RES_WHILE) {
4023 /* "while false; do...done" - exitcode 0 */
4024 G.last_exitcode = rcode = EXIT_SUCCESS;
4025 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
4026 goto check_jobs_and_break;
4029 if (rword == RES_UNTIL) {
4031 debug_printf_exec(": until expr is true: breaking\n");
4032 check_jobs_and_break:
4040 check_jobs_and_continue:
4047 #if ENABLE_HUSH_LOOPS
4052 #if ENABLE_HUSH_CASE
4056 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4060 /* Select which version we will use */
4061 static int run_and_free_list(struct pipe *pi)
4064 debug_printf_exec("run_and_free_list entered\n");
4066 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4067 rcode = run_list(pi);
4069 /* free_pipe_list has the side effect of clearing memory.
4070 * In the long run that function can be merged with run_list,
4071 * but doing that now would hobble the debugging effort. */
4073 debug_printf_exec("run_and_free_list return %d\n", rcode);
4078 static struct pipe *new_pipe(void)
4081 pi = xzalloc(sizeof(struct pipe));
4082 /*pi->followup = 0; - deliberately invalid value */
4083 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4087 /* Command (member of a pipe) is complete, or we start a new pipe
4088 * if ctx->command is NULL.
4089 * No errors possible here.
4091 static int done_command(struct parse_context *ctx)
4093 /* The command is really already in the pipe structure, so
4094 * advance the pipe counter and make a new, null command. */
4095 struct pipe *pi = ctx->pipe;
4096 struct command *command = ctx->command;
4099 if (IS_NULL_CMD(command)) {
4100 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4104 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4105 //debug_print_tree(ctx->list_head, 20);
4107 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4110 /* Only real trickiness here is that the uncommitted
4111 * command structure is not counted in pi->num_cmds. */
4112 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4113 ctx->command = command = &pi->cmds[pi->num_cmds];
4115 memset(command, 0, sizeof(*command));
4116 return pi->num_cmds; /* used only for 0/nonzero check */
4119 static void done_pipe(struct parse_context *ctx, pipe_style type)
4123 debug_printf_parse("done_pipe entered, followup %d\n", type);
4124 /* Close previous command */
4125 not_null = done_command(ctx);
4126 ctx->pipe->followup = type;
4128 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4129 ctx->ctx_inverted = 0;
4130 ctx->pipe->res_word = ctx->ctx_res_w;
4133 /* Without this check, even just <enter> on command line generates
4134 * tree of three NOPs (!). Which is harmless but annoying.
4135 * IOW: it is safe to do it unconditionally. */
4138 || ctx->ctx_res_w == RES_FI
4140 #if ENABLE_HUSH_LOOPS
4141 || ctx->ctx_res_w == RES_DONE
4142 || ctx->ctx_res_w == RES_FOR
4143 || ctx->ctx_res_w == RES_IN
4145 #if ENABLE_HUSH_CASE
4146 || ctx->ctx_res_w == RES_ESAC
4150 debug_printf_parse("done_pipe: adding new pipe: "
4151 "not_null:%d ctx->ctx_res_w:%d\n",
4152 not_null, ctx->ctx_res_w);
4154 ctx->pipe->next = new_p;
4156 /* RES_THEN, RES_DO etc are "sticky" -
4157 * they remain set for pipes inside if/while.
4158 * This is used to control execution.
4159 * RES_FOR and RES_IN are NOT sticky (needed to support
4160 * cases where variable or value happens to match a keyword):
4162 #if ENABLE_HUSH_LOOPS
4163 if (ctx->ctx_res_w == RES_FOR
4164 || ctx->ctx_res_w == RES_IN)
4165 ctx->ctx_res_w = RES_NONE;
4167 #if ENABLE_HUSH_CASE
4168 if (ctx->ctx_res_w == RES_MATCH)
4169 ctx->ctx_res_w = RES_CASEI;
4171 ctx->command = NULL; /* trick done_command below */
4172 /* Create the memory for command, roughly:
4173 * ctx->pipe->cmds = new struct command;
4174 * ctx->command = &ctx->pipe->cmds[0];
4177 //debug_print_tree(ctx->list_head, 10);
4179 debug_printf_parse("done_pipe return\n");
4182 static void initialize_context(struct parse_context *ctx)
4184 memset(ctx, 0, sizeof(*ctx));
4185 ctx->pipe = ctx->list_head = new_pipe();
4186 /* Create the memory for command, roughly:
4187 * ctx->pipe->cmds = new struct command;
4188 * ctx->command = &ctx->pipe->cmds[0];
4193 /* If a reserved word is found and processed, parse context is modified
4194 * and 1 is returned.
4197 struct reserved_combo {
4200 unsigned char assignment_flag;
4204 FLAG_END = (1 << RES_NONE ),
4206 FLAG_IF = (1 << RES_IF ),
4207 FLAG_THEN = (1 << RES_THEN ),
4208 FLAG_ELIF = (1 << RES_ELIF ),
4209 FLAG_ELSE = (1 << RES_ELSE ),
4210 FLAG_FI = (1 << RES_FI ),
4212 #if ENABLE_HUSH_LOOPS
4213 FLAG_FOR = (1 << RES_FOR ),
4214 FLAG_WHILE = (1 << RES_WHILE),
4215 FLAG_UNTIL = (1 << RES_UNTIL),
4216 FLAG_DO = (1 << RES_DO ),
4217 FLAG_DONE = (1 << RES_DONE ),
4218 FLAG_IN = (1 << RES_IN ),
4220 #if ENABLE_HUSH_CASE
4221 FLAG_MATCH = (1 << RES_MATCH),
4222 FLAG_ESAC = (1 << RES_ESAC ),
4224 FLAG_START = (1 << RES_XXXX ),
4227 static const struct reserved_combo* match_reserved_word(o_string *word)
4229 /* Mostly a list of accepted follow-up reserved words.
4230 * FLAG_END means we are done with the sequence, and are ready
4231 * to turn the compound list into a command.
4232 * FLAG_START means the word must start a new compound list.
4234 static const struct reserved_combo reserved_list[] = {
4236 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4237 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4238 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4239 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4240 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4241 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4243 #if ENABLE_HUSH_LOOPS
4244 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4245 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4246 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4247 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4248 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4249 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4251 #if ENABLE_HUSH_CASE
4252 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4253 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4256 const struct reserved_combo *r;
4258 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4259 if (strcmp(word->data, r->literal) == 0)
4264 /* Return 0: not a keyword, 1: keyword
4266 static int reserved_word(o_string *word, struct parse_context *ctx)
4268 #if ENABLE_HUSH_CASE
4269 static const struct reserved_combo reserved_match = {
4270 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4273 const struct reserved_combo *r;
4277 r = match_reserved_word(word);
4281 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4282 #if ENABLE_HUSH_CASE
4283 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4284 /* "case word IN ..." - IN part starts first match part */
4285 r = &reserved_match;
4288 if (r->flag == 0) { /* '!' */
4289 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4290 syntax_error("! ! command");
4291 ctx->ctx_res_w = RES_SNTX;
4293 ctx->ctx_inverted = 1;
4296 if (r->flag & FLAG_START) {
4297 struct parse_context *old;
4299 old = xmalloc(sizeof(*old));
4300 debug_printf_parse("push stack %p\n", old);
4301 *old = *ctx; /* physical copy */
4302 initialize_context(ctx);
4304 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4305 syntax_error_at(word->data);
4306 ctx->ctx_res_w = RES_SNTX;
4309 /* "{...} fi" is ok. "{...} if" is not
4311 * if { echo foo; } then { echo bar; } fi */
4312 if (ctx->command->group)
4313 done_pipe(ctx, PIPE_SEQ);
4316 ctx->ctx_res_w = r->res;
4317 ctx->old_flag = r->flag;
4318 word->o_assignment = r->assignment_flag;
4320 if (ctx->old_flag & FLAG_END) {
4321 struct parse_context *old;
4323 done_pipe(ctx, PIPE_SEQ);
4324 debug_printf_parse("pop stack %p\n", ctx->stack);
4326 old->command->group = ctx->list_head;
4327 old->command->grp_type = GRP_NORMAL;
4329 o_addstr(&old->as_string, ctx->as_string.data);
4330 o_free_unsafe(&ctx->as_string);
4331 old->command->group_as_string = xstrdup(old->as_string.data);
4332 debug_printf_parse("pop, remembering as:'%s'\n",
4333 old->command->group_as_string);
4335 *ctx = *old; /* physical copy */
4342 /* Word is complete, look at it and update parsing context.
4343 * Normal return is 0. Syntax errors return 1.
4344 * Note: on return, word is reset, but not o_free'd!
4346 static int done_word(o_string *word, struct parse_context *ctx)
4348 struct command *command = ctx->command;
4350 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4351 if (word->length == 0 && word->o_quoted == 0) {
4352 debug_printf_parse("done_word return 0: true null, ignored\n");
4356 if (ctx->pending_redirect) {
4357 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4358 * only if run as "bash", not "sh" */
4359 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4361 * ...the word that follows the redirection operator
4362 * shall be subjected to tilde expansion, parameter expansion,
4363 * command substitution, arithmetic expansion, and quote
4364 * removal. Pathname expansion shall not be performed
4365 * on the word by a non-interactive shell; an interactive
4366 * shell may perform it, but shall do so only when
4367 * the expansion would result in one word."
4369 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4370 /* Cater for >\file case:
4371 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4372 * Same with heredocs:
4373 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4375 unbackslash(ctx->pending_redirect->rd_filename);
4376 /* Is it <<"HEREDOC"? */
4377 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4380 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4382 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4383 ctx->pending_redirect = NULL;
4385 /* If this word wasn't an assignment, next ones definitely
4386 * can't be assignments. Even if they look like ones. */
4387 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4388 && word->o_assignment != WORD_IS_KEYWORD
4390 word->o_assignment = NOT_ASSIGNMENT;
4392 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4393 command->assignment_cnt++;
4394 word->o_assignment = MAYBE_ASSIGNMENT;
4398 # if ENABLE_HUSH_CASE
4399 if (ctx->ctx_dsemicolon
4400 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4402 /* already done when ctx_dsemicolon was set to 1: */
4403 /* ctx->ctx_res_w = RES_MATCH; */
4404 ctx->ctx_dsemicolon = 0;
4407 if (!command->argv /* if it's the first word... */
4408 # if ENABLE_HUSH_LOOPS
4409 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4410 && ctx->ctx_res_w != RES_IN
4413 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4414 if (reserved_word(word, ctx)) {
4415 o_reset_to_empty_unquoted(word);
4416 debug_printf_parse("done_word return %d\n",
4417 (ctx->ctx_res_w == RES_SNTX));
4418 return (ctx->ctx_res_w == RES_SNTX);
4422 if (command->group) {
4423 /* "{ echo foo; } echo bar" - bad */
4424 syntax_error_at(word->data);
4425 debug_printf_parse("done_word return 1: syntax error, "
4426 "groups and arglists don't mix\n");
4429 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4430 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4431 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4432 /* (otherwise it's known to be not empty and is already safe) */
4434 /* exclude "$@" - it can expand to no word despite "" */
4435 char *p = word->data;
4436 while (p[0] == SPECIAL_VAR_SYMBOL
4437 && (p[1] & 0x7f) == '@'
4438 && p[2] == SPECIAL_VAR_SYMBOL
4442 if (p == word->data || p[0] != '\0') {
4443 /* saw no "$@", or not only "$@" but some
4444 * real text is there too */
4445 /* insert "empty variable" reference, this makes
4446 * e.g. "", $empty"" etc to not disappear */
4447 o_addchr(word, SPECIAL_VAR_SYMBOL);
4448 o_addchr(word, SPECIAL_VAR_SYMBOL);
4451 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4452 //SEGV, but good idea.
4453 // command->argv = add_string_to_strings(command->argv, word->data);
4454 // word->data = NULL;
4455 // word->length = 0;
4456 debug_print_strings("word appended to argv", command->argv);
4459 #if ENABLE_HUSH_LOOPS
4460 if (ctx->ctx_res_w == RES_FOR) {
4462 || !is_well_formed_var_name(command->argv[0], '\0')
4464 /* bash says just "not a valid identifier" */
4465 syntax_error("not a valid identifier in for");
4468 /* Force FOR to have just one word (variable name) */
4469 /* NB: basically, this makes hush see "for v in ..."
4470 * syntax as if it is "for v; in ...". FOR and IN become
4471 * two pipe structs in parse tree. */
4472 done_pipe(ctx, PIPE_SEQ);
4475 #if ENABLE_HUSH_CASE
4476 /* Force CASE to have just one word */
4477 if (ctx->ctx_res_w == RES_CASE) {
4478 done_pipe(ctx, PIPE_SEQ);
4482 o_reset_to_empty_unquoted(word);
4484 debug_printf_parse("done_word return 0\n");
4489 /* Peek ahead in the input to find out if we have a "&n" construct,
4490 * as in "2>&1", that represents duplicating a file descriptor.
4492 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4493 * REDIRFD_SYNTAX_ERR if syntax error,
4494 * REDIRFD_TO_FILE if no & was seen,
4495 * or the number found.
4498 #define parse_redir_right_fd(as_string, input) \
4499 parse_redir_right_fd(input)
4501 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4507 return REDIRFD_TO_FILE;
4509 ch = i_getch(input); /* get the & */
4510 nommu_addchr(as_string, ch);
4513 ch = i_getch(input);
4514 nommu_addchr(as_string, ch);
4515 return REDIRFD_CLOSE;
4519 while (ch != EOF && isdigit(ch)) {
4520 d = d*10 + (ch-'0');
4522 ch = i_getch(input);
4523 nommu_addchr(as_string, ch);
4528 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4530 bb_error_msg("ambiguous redirect");
4531 return REDIRFD_SYNTAX_ERR;
4534 /* Return code is 0 normal, 1 if a syntax error is detected
4536 static int parse_redirect(struct parse_context *ctx,
4539 struct in_str *input)
4541 struct command *command = ctx->command;
4542 struct redir_struct *redir;
4543 struct redir_struct **redirp;
4546 dup_num = REDIRFD_TO_FILE;
4547 if (style != REDIRECT_HEREDOC) {
4548 /* Check for a '>&1' type redirect */
4549 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4550 if (dup_num == REDIRFD_SYNTAX_ERR)
4553 int ch = i_peek(input);
4554 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4555 if (dup_num) { /* <<-... */
4556 ch = i_getch(input);
4557 nommu_addchr(&ctx->as_string, ch);
4562 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4563 int ch = i_peek(input);
4565 /* >|FILE redirect ("clobbering" >).
4566 * Since we do not support "set -o noclobber" yet,
4567 * >| and > are the same for now. Just eat |.
4569 ch = i_getch(input);
4570 nommu_addchr(&ctx->as_string, ch);
4574 /* Create a new redir_struct and append it to the linked list */
4575 redirp = &command->redirects;
4576 while ((redir = *redirp) != NULL) {
4577 redirp = &(redir->next);
4579 *redirp = redir = xzalloc(sizeof(*redir));
4580 /* redir->next = NULL; */
4581 /* redir->rd_filename = NULL; */
4582 redir->rd_type = style;
4583 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4585 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4586 redir_table[style].descrip);
4588 redir->rd_dup = dup_num;
4589 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4590 /* Erik had a check here that the file descriptor in question
4591 * is legit; I postpone that to "run time"
4592 * A "-" representation of "close me" shows up as a -3 here */
4593 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4594 redir->rd_fd, redir->rd_dup);
4596 /* Set ctx->pending_redirect, so we know what to do at the
4597 * end of the next parsed word. */
4598 ctx->pending_redirect = redir;
4603 /* If a redirect is immediately preceded by a number, that number is
4604 * supposed to tell which file descriptor to redirect. This routine
4605 * looks for such preceding numbers. In an ideal world this routine
4606 * needs to handle all the following classes of redirects...
4607 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4608 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4609 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4610 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4612 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4614 * ... If n is quoted, the number shall not be recognized as part of
4615 * the redirection expression. For example:
4617 * writes the character 2 into file a"
4618 * We are getting it right by setting ->o_quoted on any \<char>
4620 * A -1 return means no valid number was found,
4621 * the caller should use the appropriate default for this redirection.
4623 static int redirect_opt_num(o_string *o)
4627 if (o->data == NULL)
4629 num = bb_strtou(o->data, NULL, 10);
4630 if (errno || num < 0)
4632 o_reset_to_empty_unquoted(o);
4637 #define fetch_till_str(as_string, input, word, skip_tabs) \
4638 fetch_till_str(input, word, skip_tabs)
4640 static char *fetch_till_str(o_string *as_string,
4641 struct in_str *input,
4645 o_string heredoc = NULL_O_STRING;
4651 ch = i_getch(input);
4652 nommu_addchr(as_string, ch);
4654 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4655 heredoc.data[past_EOL] = '\0';
4656 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4657 return heredoc.data;
4660 o_addchr(&heredoc, ch);
4661 past_EOL = heredoc.length;
4664 ch = i_getch(input);
4665 nommu_addchr(as_string, ch);
4666 } while (skip_tabs && ch == '\t');
4667 } while (ch == '\n');
4670 o_free_unsafe(&heredoc);
4673 o_addchr(&heredoc, ch);
4674 nommu_addchr(as_string, ch);
4678 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4679 * and load them all. There should be exactly heredoc_cnt of them.
4681 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4683 struct pipe *pi = ctx->list_head;
4685 while (pi && heredoc_cnt) {
4687 struct command *cmd = pi->cmds;
4689 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4691 cmd->argv ? cmd->argv[0] : "NONE");
4692 for (i = 0; i < pi->num_cmds; i++) {
4693 struct redir_struct *redir = cmd->redirects;
4695 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4696 i, cmd->argv ? cmd->argv[0] : "NONE");
4698 if (redir->rd_type == REDIRECT_HEREDOC) {
4701 redir->rd_type = REDIRECT_HEREDOC2;
4702 /* redir->dup is (ab)used to indicate <<- */
4703 p = fetch_till_str(&ctx->as_string, input,
4704 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4706 syntax_error("unexpected EOF in here document");
4709 free(redir->rd_filename);
4710 redir->rd_filename = p;
4713 redir = redir->next;
4720 /* Should be 0. If it isn't, it's a parse error */
4722 bb_error_msg_and_die("heredoc BUG 2");
4728 #if ENABLE_HUSH_TICK
4729 static FILE *generate_stream_from_string(const char *s)
4732 int pid, channel[2];
4738 pid = BB_MMU ? fork() : vfork();
4740 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4742 if (pid == 0) { /* child */
4743 disable_restore_tty_pgrp_on_exit();
4744 /* Process substitution is not considered to be usual
4745 * 'command execution'.
4746 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4753 close(channel[0]); /* NB: close _first_, then move fd! */
4754 xmove_fd(channel[1], 1);
4755 /* Prevent it from trying to handle ctrl-z etc */
4756 USE_HUSH_JOB(G.run_list_level = 1;)
4758 reset_traps_to_defaults();
4759 parse_and_run_string(s);
4760 _exit(G.last_exitcode);
4762 /* We re-execute after vfork on NOMMU. This makes this script safe:
4763 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4764 * huge=`cat BIG` # was blocking here forever
4767 re_execute_shell(&to_free,
4775 enable_restore_tty_pgrp_on_exit();
4780 pf = fdopen(channel[0], "r");
4784 /* Return code is exit status of the process that is run. */
4785 static int process_command_subs(o_string *dest, const char *s)
4788 struct in_str pipe_str;
4791 pf = generate_stream_from_string(s);
4794 close_on_exec_on(fileno(pf));
4796 /* Now send results of command back into original context */
4797 setup_file_in_str(&pipe_str, pf);
4799 while ((ch = i_getch(&pipe_str)) != EOF) {
4805 o_addchr(dest, '\n');
4808 o_addQchr(dest, ch);
4811 debug_printf("done reading from pipe, pclose()ing\n");
4812 /* Note: we got EOF, and we just close the read end of the pipe.
4813 * We do not wait for the `cmd` child to terminate. bash and ash do.
4815 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4816 * `false`; echo $? - bash outputs "1"
4819 debug_printf("closed FILE from child. return 0\n");
4824 static int parse_group(o_string *dest, struct parse_context *ctx,
4825 struct in_str *input, int ch)
4827 /* dest contains characters seen prior to ( or {.
4828 * Typically it's empty, but for function defs,
4829 * it contains function name (without '()'). */
4830 struct pipe *pipe_list;
4832 struct command *command = ctx->command;
4834 debug_printf_parse("parse_group entered\n");
4835 #if ENABLE_HUSH_FUNCTIONS
4836 if (ch == '(' && !dest->o_quoted) {
4838 if (done_word(dest, ctx))
4841 goto skip; /* (... */
4842 if (command->argv[1]) { /* word word ... (... */
4843 syntax_error_unexpected_ch('(');
4846 /* it is "word(..." or "word (..." */
4848 ch = i_getch(input);
4849 while (ch == ' ' || ch == '\t');
4851 syntax_error_unexpected_ch(ch);
4854 nommu_addchr(&ctx->as_string, ch);
4856 ch = i_getch(input);
4857 while (ch == ' ' || ch == '\t' || ch == '\n');
4859 syntax_error_unexpected_ch(ch);
4862 nommu_addchr(&ctx->as_string, ch);
4863 command->grp_type = GRP_FUNCTION;
4867 if (command->argv /* word [word]{... */
4868 || dest->length /* word{... */
4869 || dest->o_quoted /* ""{... */
4872 debug_printf_parse("parse_group return 1: "
4873 "syntax error, groups and arglists don't mix\n");
4877 #if ENABLE_HUSH_FUNCTIONS
4883 command->grp_type = GRP_SUBSHELL;
4885 /* bash does not allow "{echo...", requires whitespace */
4886 ch = i_getch(input);
4887 if (ch != ' ' && ch != '\t' && ch != '\n') {
4888 syntax_error_unexpected_ch(ch);
4891 nommu_addchr(&ctx->as_string, ch);
4896 char *as_string = NULL;
4898 pipe_list = parse_stream(&as_string, input, endch);
4901 o_addstr(&ctx->as_string, as_string);
4903 /* empty ()/{} or parse error? */
4904 if (!pipe_list || pipe_list == ERR_PTR) {
4905 /* parse_stream already emitted error msg */
4909 debug_printf_parse("parse_group return 1: "
4910 "parse_stream returned %p\n", pipe_list);
4913 command->group = pipe_list;
4915 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4916 command->group_as_string = as_string;
4917 debug_printf_parse("end of group, remembering as:'%s'\n",
4918 command->group_as_string);
4921 debug_printf_parse("parse_group return 0\n");
4923 /* command remains "open", available for possible redirects */
4926 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4927 /* Subroutines for copying $(...) and `...` things */
4928 static void add_till_backquote(o_string *dest, struct in_str *input);
4930 static void add_till_single_quote(o_string *dest, struct in_str *input)
4933 int ch = i_getch(input);
4935 syntax_error_unterm_ch('\'');
4936 /*xfunc_die(); - redundant */
4943 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4944 static void add_till_double_quote(o_string *dest, struct in_str *input)
4947 int ch = i_getch(input);
4949 syntax_error_unterm_ch('"');
4950 /*xfunc_die(); - redundant */
4954 if (ch == '\\') { /* \x. Copy both chars. */
4956 ch = i_getch(input);
4960 add_till_backquote(dest, input);
4964 //if (ch == '$') ...
4967 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4969 * "Within the backquoted style of command substitution, backslash
4970 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4971 * The search for the matching backquote shall be satisfied by the first
4972 * backquote found without a preceding backslash; during this search,
4973 * if a non-escaped backquote is encountered within a shell comment,
4974 * a here-document, an embedded command substitution of the $(command)
4975 * form, or a quoted string, undefined results occur. A single-quoted
4976 * or double-quoted string that begins, but does not end, within the
4977 * "`...`" sequence produces undefined results."
4979 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4981 static void add_till_backquote(o_string *dest, struct in_str *input)
4984 int ch = i_getch(input);
4986 syntax_error_unterm_ch('`');
4987 /*xfunc_die(); - redundant */
4992 /* \x. Copy both chars unless it is \` */
4993 int ch2 = i_getch(input);
4995 syntax_error_unterm_ch('`');
4996 /*xfunc_die(); - redundant */
4998 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
5005 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
5006 * quoting and nested ()s.
5007 * "With the $(command) style of command substitution, all characters
5008 * following the open parenthesis to the matching closing parenthesis
5009 * constitute the command. Any valid shell script can be used for command,
5010 * except a script consisting solely of redirections which produces
5011 * unspecified results."
5013 * echo $(echo '(TEST)' BEST) (TEST) BEST
5014 * echo $(echo 'TEST)' BEST) TEST) BEST
5015 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
5017 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
5021 int ch = i_getch(input);
5023 syntax_error_unterm_ch(')');
5024 /*xfunc_die(); - redundant */
5032 if (i_peek(input) == ')') {
5040 add_till_single_quote(dest, input);
5045 add_till_double_quote(dest, input);
5050 /* \x. Copy verbatim. Important for \(, \) */
5051 ch = i_getch(input);
5053 syntax_error_unterm_ch(')');
5054 /*xfunc_die(); - redundant */
5061 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5063 /* Return code: 0 for OK, 1 for syntax error */
5065 #define handle_dollar(as_string, dest, input) \
5066 handle_dollar(dest, input)
5068 static int handle_dollar(o_string *as_string,
5070 struct in_str *input)
5073 int ch = i_peek(input); /* first character after the $ */
5074 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5076 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5078 ch = i_getch(input);
5079 nommu_addchr(as_string, ch);
5081 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5083 debug_printf_parse(": '%c'\n", ch);
5084 o_addchr(dest, ch | quote_mask);
5087 if (!isalnum(ch) && ch != '_')
5089 ch = i_getch(input);
5090 nommu_addchr(as_string, ch);
5092 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5093 } else if (isdigit(ch)) {
5095 ch = i_getch(input);
5096 nommu_addchr(as_string, ch);
5097 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5098 debug_printf_parse(": '%c'\n", ch);
5099 o_addchr(dest, ch | quote_mask);
5100 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5101 } else switch (ch) {
5103 case '!': /* last bg pid */
5104 case '?': /* last exit code */
5105 case '#': /* number of args */
5106 case '*': /* args */
5107 case '@': /* args */
5108 goto make_one_char_var;
5110 bool first_char, all_digits;
5112 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5113 ch = i_getch(input);
5114 nommu_addchr(as_string, ch);
5115 /* TODO: maybe someone will try to escape the '}' */
5120 ch = i_getch(input);
5121 nommu_addchr(as_string, ch);
5127 /* ${#var}: length of var contents */
5129 else if (isdigit(ch)) {
5136 && ( (all_digits && !isdigit(ch))
5137 || (!all_digits && !isalnum(ch) && ch != '_')
5140 /* handle parameter expansions
5141 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5146 case ':': /* null modifier */
5147 if (expansion == 0) {
5148 debug_printf_parse(": null modifier\n");
5153 case '#': /* remove prefix */
5154 case '%': /* remove suffix */
5155 if (expansion == 0) {
5156 debug_printf_parse(": remove suffix/prefix\n");
5161 case '-': /* default value */
5162 case '=': /* assign default */
5163 case '+': /* alternative */
5164 case '?': /* error indicate */
5165 debug_printf_parse(": parameter expansion\n");
5170 syntax_error_unterm_str("${name}");
5171 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5176 debug_printf_parse(": '%c'\n", ch);
5177 o_addchr(dest, ch | quote_mask);
5181 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5184 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5189 ch = i_getch(input);
5190 nommu_addchr(as_string, ch);
5191 # if ENABLE_SH_MATH_SUPPORT
5192 if (i_peek(input) == '(') {
5193 ch = i_getch(input);
5194 nommu_addchr(as_string, ch);
5195 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5196 o_addchr(dest, /*quote_mask |*/ '+');
5200 add_till_closing_paren(dest, input, true);
5203 o_addstr(as_string, dest->data + pos);
5204 o_addchr(as_string, ')');
5205 o_addchr(as_string, ')');
5208 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5212 # if ENABLE_HUSH_TICK
5213 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5214 o_addchr(dest, quote_mask | '`');
5218 add_till_closing_paren(dest, input, false);
5221 o_addstr(as_string, dest->data + pos);
5222 o_addchr(as_string, '`');
5225 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5231 ch = i_getch(input);
5232 nommu_addchr(as_string, ch);
5234 if (isalnum(ch)) { /* it's $_name or $_123 */
5240 /* $_ Shell or shell script name; or last cmd name */
5241 /* $- Option flags set by set builtin or shell options (-i etc) */
5243 o_addQchr(dest, '$');
5245 debug_printf_parse("handle_dollar return 0\n");
5250 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5251 parse_stream_dquoted(dest, input, dquote_end)
5253 static int parse_stream_dquoted(o_string *as_string,
5255 struct in_str *input,
5262 ch = i_getch(input);
5264 nommu_addchr(as_string, ch);
5265 if (ch == dquote_end) { /* may be only '"' or EOF */
5266 if (dest->o_assignment == NOT_ASSIGNMENT)
5267 dest->o_escape ^= 1;
5268 debug_printf_parse("parse_stream_dquoted return 0\n");
5271 /* note: can't move it above ch == dquote_end check! */
5273 syntax_error_unterm_ch('"');
5274 /*xfunc_die(); - redundant */
5278 next = i_peek(input);
5280 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5281 ch, ch, dest->o_escape);
5284 syntax_error("\\<eof>");
5288 * "The backslash retains its special meaning [in "..."]
5289 * only when followed by one of the following characters:
5290 * $, `, ", \, or <newline>. A double quote may be quoted
5291 * within double quotes by preceding it with a backslash.
5293 if (strchr("$`\"\\", next) != NULL) {
5294 o_addqchr(dest, i_getch(input));
5296 o_addqchr(dest, '\\');
5301 if (handle_dollar(as_string, dest, input) != 0) {
5302 debug_printf_parse("parse_stream_dquoted return 1: "
5303 "handle_dollar returned non-0\n");
5308 #if ENABLE_HUSH_TICK
5310 //int pos = dest->length;
5311 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5312 o_addchr(dest, 0x80 | '`');
5313 add_till_backquote(dest, input);
5314 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5315 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5319 o_addQchr(dest, ch);
5321 && (dest->o_assignment == MAYBE_ASSIGNMENT
5322 || dest->o_assignment == WORD_IS_KEYWORD)
5323 && is_well_formed_var_name(dest->data, '=')
5325 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5331 * Scan input until EOF or end_trigger char.
5332 * Return a list of pipes to execute, or NULL on EOF
5333 * or if end_trigger character is met.
5334 * On syntax error, exit is shell is not interactive,
5335 * reset parsing machinery and start parsing anew,
5336 * or return ERR_PTR.
5338 static struct pipe *parse_stream(char **pstring,
5339 struct in_str *input,
5342 struct parse_context ctx;
5343 o_string dest = NULL_O_STRING;
5347 /* Double-quote state is handled in the state variable is_in_dquote.
5348 * A single-quote triggers a bypass of the main loop until its mate is
5349 * found. When recursing, quote state is passed in via dest->o_escape.
5351 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5352 end_trigger ? : 'X');
5355 G.ifs = get_local_var_value("IFS");
5360 #if ENABLE_HUSH_INTERACTIVE
5361 input->promptmode = 0; /* PS1 */
5363 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5364 initialize_context(&ctx);
5369 const char *is_special;
5373 redir_type redir_style;
5376 /* dest.o_quoted = 1; - already is (see below) */
5377 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5380 /* We reached closing '"' */
5383 ch = i_getch(input);
5384 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5385 ch, ch, dest.o_escape);
5390 syntax_error_unterm_str("here document");
5393 if (done_word(&dest, &ctx)) {
5397 done_pipe(&ctx, PIPE_SEQ);
5399 /* If we got nothing... */
5400 /* (this makes bare "&" cmd a no-op.
5401 * bash says: "syntax error near unexpected token '&'") */
5402 if (pi->num_cmds == 0
5403 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5409 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5411 *pstring = ctx.as_string.data;
5413 o_free_unsafe(&ctx.as_string);
5416 debug_printf_parse("parse_stream return %p\n", pi);
5419 nommu_addchr(&ctx.as_string, ch);
5420 is_ifs = strchr(G.ifs, ch);
5421 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5422 "\\$\"" USE_HUSH_TICK("`") /* always special */
5425 if (!is_special && !is_ifs) { /* ordinary char */
5426 o_addQchr(&dest, ch);
5427 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5428 || dest.o_assignment == WORD_IS_KEYWORD)
5430 && is_well_formed_var_name(dest.data, '=')
5432 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5438 if (done_word(&dest, &ctx)) {
5442 #if ENABLE_HUSH_CASE
5443 /* "case ... in <newline> word) ..." -
5444 * newlines are ignored (but ';' wouldn't be) */
5445 if (ctx.command->argv == NULL
5446 && ctx.ctx_res_w == RES_MATCH
5451 /* Treat newline as a command separator. */
5452 done_pipe(&ctx, PIPE_SEQ);
5453 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5455 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5460 dest.o_assignment = MAYBE_ASSIGNMENT;
5462 /* note: if (is_ifs) continue;
5463 * will still trigger for us */
5466 if (end_trigger && end_trigger == ch
5467 && (heredoc_cnt == 0 || end_trigger != ';')
5470 /* This is technically valid:
5471 * { cat <<HERE; }; echo Ok
5475 * but we don't support this.
5476 * We require heredoc to be in enclosing {}/(),
5479 syntax_error_unterm_str("here document");
5482 if (done_word(&dest, &ctx)) {
5485 /* Disallow "{ cmd }" without semicolon or & */
5486 //debug_printf_parse("null pi %d\n", IS_NULL_PIPE(ctx.pipe))
5487 //debug_printf_parse("null cmd %d\n", IS_NULL_CMD(ctx.command))
5489 && !(IS_NULL_PIPE(ctx.pipe) && IS_NULL_CMD(ctx.command))
5491 syntax_error_unexpected_ch(ch);
5494 done_pipe(&ctx, PIPE_SEQ);
5495 dest.o_assignment = MAYBE_ASSIGNMENT;
5496 /* Do we sit outside of any if's, loops or case's? */
5498 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5502 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5504 *pstring = ctx.as_string.data;
5506 o_free_unsafe(&ctx.as_string);
5509 debug_printf_parse("parse_stream return %p: "
5510 "end_trigger char found\n",
5512 return ctx.list_head;
5520 next = i_peek(input);
5523 /* Catch <, > before deciding whether this word is
5524 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5527 redir_fd = redirect_opt_num(&dest);
5528 if (done_word(&dest, &ctx)) {
5531 redir_style = REDIRECT_OVERWRITE;
5533 redir_style = REDIRECT_APPEND;
5534 ch = i_getch(input);
5535 nommu_addchr(&ctx.as_string, ch);
5538 else if (next == '(') {
5539 syntax_error(">(process) not supported");
5543 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5545 continue; /* back to top of while (1) */
5547 redir_fd = redirect_opt_num(&dest);
5548 if (done_word(&dest, &ctx)) {
5551 redir_style = REDIRECT_INPUT;
5553 redir_style = REDIRECT_HEREDOC;
5555 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5556 ch = i_getch(input);
5557 nommu_addchr(&ctx.as_string, ch);
5558 } else if (next == '>') {
5559 redir_style = REDIRECT_IO;
5560 ch = i_getch(input);
5561 nommu_addchr(&ctx.as_string, ch);
5564 else if (next == '(') {
5565 syntax_error("<(process) not supported");
5569 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5571 continue; /* back to top of while (1) */
5574 if (dest.o_assignment == MAYBE_ASSIGNMENT
5575 /* check that we are not in word in "a=1 2>word b=1": */
5576 && !ctx.pending_redirect
5578 /* ch is a special char and thus this word
5579 * cannot be an assignment */
5580 dest.o_assignment = NOT_ASSIGNMENT;
5585 if (dest.length == 0) {
5588 if (ch == EOF || ch == '\n')
5591 /* note: we do not add it to &ctx.as_string */
5593 nommu_addchr(&ctx.as_string, '\n');
5595 o_addQchr(&dest, ch);
5600 syntax_error("\\<eof>");
5603 o_addchr(&dest, '\\');
5604 ch = i_getch(input);
5605 nommu_addchr(&ctx.as_string, ch);
5606 o_addchr(&dest, ch);
5607 /* Example: echo Hello \2>file
5608 * we need to know that word 2 is quoted */
5612 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5613 debug_printf_parse("parse_stream parse error: "
5614 "handle_dollar returned non-0\n");
5621 ch = i_getch(input);
5623 syntax_error_unterm_ch('\'');
5624 /*xfunc_die(); - redundant */
5626 nommu_addchr(&ctx.as_string, ch);
5629 if (dest.o_assignment == NOT_ASSIGNMENT)
5630 o_addqchr(&dest, ch);
5632 o_addchr(&dest, ch);
5637 is_in_dquote ^= 1; /* invert */
5638 if (dest.o_assignment == NOT_ASSIGNMENT)
5641 #if ENABLE_HUSH_TICK
5646 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5647 o_addchr(&dest, '`');
5651 add_till_backquote(&dest, input);
5653 o_addstr(&ctx.as_string, dest.data + pos);
5654 o_addchr(&ctx.as_string, '`');
5656 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5657 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5662 #if ENABLE_HUSH_CASE
5665 if (done_word(&dest, &ctx)) {
5668 done_pipe(&ctx, PIPE_SEQ);
5669 #if ENABLE_HUSH_CASE
5670 /* Eat multiple semicolons, detect
5671 * whether it means something special */
5676 ch = i_getch(input);
5677 nommu_addchr(&ctx.as_string, ch);
5678 if (ctx.ctx_res_w == RES_CASEI) {
5679 ctx.ctx_dsemicolon = 1;
5680 ctx.ctx_res_w = RES_MATCH;
5686 /* We just finished a cmd. New one may start
5687 * with an assignment */
5688 dest.o_assignment = MAYBE_ASSIGNMENT;
5691 if (done_word(&dest, &ctx)) {
5695 ch = i_getch(input);
5696 nommu_addchr(&ctx.as_string, ch);
5697 done_pipe(&ctx, PIPE_AND);
5699 done_pipe(&ctx, PIPE_BG);
5703 if (done_word(&dest, &ctx)) {
5706 #if ENABLE_HUSH_CASE
5707 if (ctx.ctx_res_w == RES_MATCH)
5708 break; /* we are in case's "word | word)" */
5710 if (next == '|') { /* || */
5711 ch = i_getch(input);
5712 nommu_addchr(&ctx.as_string, ch);
5713 done_pipe(&ctx, PIPE_OR);
5715 /* we could pick up a file descriptor choice here
5716 * with redirect_opt_num(), but bash doesn't do it.
5717 * "echo foo 2| cat" yields "foo 2". */
5722 #if ENABLE_HUSH_CASE
5723 /* "case... in [(]word)..." - skip '(' */
5724 if (ctx.ctx_res_w == RES_MATCH
5725 && ctx.command->argv == NULL /* not (word|(... */
5726 && dest.length == 0 /* not word(... */
5727 && dest.o_quoted == 0 /* not ""(... */
5733 if (parse_group(&dest, &ctx, input, ch) != 0) {
5738 #if ENABLE_HUSH_CASE
5739 if (ctx.ctx_res_w == RES_MATCH)
5743 /* proper use of this character is caught by end_trigger:
5744 * if we see {, we call parse_group(..., end_trigger='}')
5745 * and it will match } earlier (not here). */
5746 syntax_error_unexpected_ch(ch);
5750 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5756 struct parse_context *pctx;
5757 IF_HAS_KEYWORDS(struct parse_context *p2;)
5759 /* Clean up allocated tree.
5760 * Samples for finding leaks on syntax error recovery path.
5761 * Run them from interactive shell, watch pmap `pidof hush`.
5762 * while if false; then false; fi do break; done
5764 * while if false; then false; fi; do break; fi
5765 * Samples to catch leaks at execution:
5766 * while if (true | {true;}); then echo ok; fi; do break; done
5767 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5771 /* Update pipe/command counts,
5772 * otherwise freeing may miss some */
5773 done_pipe(pctx, PIPE_SEQ);
5774 debug_printf_clean("freeing list %p from ctx %p\n",
5775 pctx->list_head, pctx);
5776 debug_print_tree(pctx->list_head, 0);
5777 free_pipe_list(pctx->list_head);
5778 debug_printf_clean("freed list %p\n", pctx->list_head);
5780 o_free_unsafe(&pctx->as_string);
5782 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5786 IF_HAS_KEYWORDS(pctx = p2;)
5787 } while (HAS_KEYWORDS && pctx);
5788 /* Free text, clear all dest fields */
5790 /* If we are not in top-level parse, we return,
5791 * our caller will propagate error.
5793 if (end_trigger != ';') {
5801 /* Discard cached input, force prompt */
5803 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5808 /* Executing from string: eval, sh -c '...'
5809 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5810 * end_trigger controls how often we stop parsing
5811 * NUL: parse all, execute, return
5812 * ';': parse till ';' or newline, execute, repeat till EOF
5814 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5817 struct pipe *pipe_list;
5819 pipe_list = parse_stream(NULL, inp, end_trigger);
5820 if (!pipe_list) /* EOF */
5822 debug_print_tree(pipe_list, 0);
5823 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5824 run_and_free_list(pipe_list);
5828 static void parse_and_run_string(const char *s)
5830 struct in_str input;
5831 setup_string_in_str(&input, s);
5832 parse_and_run_stream(&input, '\0');
5835 static void parse_and_run_file(FILE *f)
5837 struct in_str input;
5838 setup_file_in_str(&input, f);
5839 parse_and_run_stream(&input, ';');
5842 /* Called a few times only (or even once if "sh -c") */
5843 static void block_signals(int second_time)
5848 mask = (1 << SIGQUIT);
5849 if (G_interactive_fd)
5850 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5851 G.non_DFL_mask = mask;
5854 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5858 sigaddset(&G.blocked_set, sig);
5862 sigdelset(&G.blocked_set, SIGCHLD);
5864 sigprocmask(SIG_SETMASK, &G.blocked_set,
5865 second_time ? NULL : &G.inherited_set);
5866 /* POSIX allows shell to re-enable SIGCHLD
5867 * even if it was SIG_IGN on entry */
5868 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5870 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5875 static void maybe_set_to_sigexit(int sig)
5877 void (*handler)(int);
5878 /* non_DFL_mask'ed signals are, well, masked,
5879 * no need to set handler for them.
5881 if (!((G.non_DFL_mask >> sig) & 1)) {
5882 handler = signal(sig, sigexit);
5883 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5884 signal(sig, handler);
5887 /* Set handlers to restore tty pgrp and exit */
5888 static void set_fatal_handlers(void)
5890 /* We _must_ restore tty pgrp on fatal signals */
5892 maybe_set_to_sigexit(SIGILL );
5893 maybe_set_to_sigexit(SIGFPE );
5894 maybe_set_to_sigexit(SIGBUS );
5895 maybe_set_to_sigexit(SIGSEGV);
5896 maybe_set_to_sigexit(SIGTRAP);
5897 } /* else: hush is perfect. what SEGV? */
5898 maybe_set_to_sigexit(SIGABRT);
5899 /* bash 3.2 seems to handle these just like 'fatal' ones */
5900 maybe_set_to_sigexit(SIGPIPE);
5901 maybe_set_to_sigexit(SIGALRM);
5902 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
5903 * if we aren't interactive... but in this case
5904 * we never want to restore pgrp on exit, and this fn is not called */
5905 /*maybe_set_to_sigexit(SIGHUP );*/
5906 /*maybe_set_to_sigexit(SIGTERM);*/
5907 /*maybe_set_to_sigexit(SIGINT );*/
5911 static int set_mode(const char cstate, const char mode)
5913 int state = (cstate == '-' ? 1 : 0);
5915 case 'n': G.fake_mode = state; break;
5916 case 'x': /*G.debug_mode = state;*/ break;
5917 default: return EXIT_FAILURE;
5919 return EXIT_SUCCESS;
5922 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5923 int hush_main(int argc, char **argv)
5925 static const struct variable const_shell_ver = {
5927 .varstr = (char*)hush_version_str,
5928 .max_len = 1, /* 0 can provoke free(name) */
5932 int signal_mask_is_inited = 0;
5935 struct variable *cur_var;
5938 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5939 G.last_exitcode = EXIT_SUCCESS;
5941 G.argv0_for_re_execing = argv[0];
5943 /* Deal with HUSH_VERSION */
5944 G.shell_ver = const_shell_ver; /* copying struct here */
5945 G.top_var = &G.shell_ver;
5946 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5947 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5948 /* Initialize our shell local variables with the values
5949 * currently living in the environment */
5950 cur_var = G.top_var;
5953 char *value = strchr(*e, '=');
5954 if (value) { /* paranoia */
5955 cur_var->next = xzalloc(sizeof(*cur_var));
5956 cur_var = cur_var->next;
5957 cur_var->varstr = *e;
5958 cur_var->max_len = strlen(*e);
5959 cur_var->flg_export = 1;
5963 debug_printf_env("putenv '%s'\n", hush_version_str);
5964 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5965 #if ENABLE_FEATURE_EDITING
5966 G.line_input_state = new_line_input_t(FOR_SHELL);
5968 G.global_argc = argc;
5969 G.global_argv = argv;
5970 /* Initialize some more globals to non-zero values */
5972 #if ENABLE_HUSH_INTERACTIVE
5973 if (ENABLE_FEATURE_EDITING)
5974 cmdedit_set_initial_prompt();
5978 if (setjmp(die_jmp)) {
5979 /* xfunc has failed! die die die */
5980 /* no EXIT traps, this is an escape hatch! */
5982 hush_exit(xfunc_error_retval);
5985 /* Shell is non-interactive at first. We need to call
5986 * block_signals(0) if we are going to execute "sh <script>",
5987 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5988 * If we later decide that we are interactive, we run block_signals(0)
5989 * (or re-run block_signals(1) if we ran block_signals(0) before)
5990 * in order to intercept (more) signals.
5994 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5996 opt = getopt(argc, argv, "c:xins"
5999 # if ENABLE_HUSH_FUNCTIONS
6009 G.root_pid = getpid();
6010 G.global_argv = argv + optind;
6011 if (!argv[optind]) {
6012 /* -c 'script' (no params): prevent empty $0 */
6013 *--G.global_argv = argv[0];
6015 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
6016 G.global_argc = argc - optind;
6017 block_signals(0); /* 0: called 1st time */
6018 parse_and_run_string(optarg);
6021 /* Well, we cannot just declare interactiveness,
6022 * we have to have some stuff (ctty, etc) */
6023 /* G_interactive_fd++; */
6026 /* "-s" means "read from stdin", but this is how we always
6027 * operate, so simply do nothing here. */
6030 case '<': /* "big heredoc" support */
6031 full_write(STDOUT_FILENO, optarg, strlen(optarg));
6034 G.root_pid = bb_strtou(optarg, &optarg, 16);
6036 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
6038 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
6039 # if ENABLE_HUSH_LOOPS
6041 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6046 set_local_var(xstrdup(optarg), 0, opt == 'R');
6048 # if ENABLE_HUSH_FUNCTIONS
6050 struct function *funcp = new_function(optarg);
6051 /* funcp->name is already set to optarg */
6052 /* funcp->body is set to NULL. It's a special case. */
6053 funcp->body_as_string = argv[optind];
6061 if (!set_mode('-', opt))
6065 fprintf(stderr, "Usage: sh [FILE]...\n"
6066 " or: sh -c command [args]...\n\n");
6072 } /* option parsing loop */
6075 G.root_pid = getpid();
6077 /* If we are login shell... */
6078 if (argv[0] && argv[0][0] == '-') {
6080 /* TODO: what should argv be while sourcing /etc/profile? */
6081 debug_printf("sourcing /etc/profile\n");
6082 input = fopen_for_read("/etc/profile");
6083 if (input != NULL) {
6084 close_on_exec_on(fileno(input));
6085 block_signals(0); /* 0: called 1st time */
6086 signal_mask_is_inited = 1;
6087 parse_and_run_file(input);
6090 /* bash: after sourcing /etc/profile,
6091 * tries to source (in the given order):
6092 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6093 * stopping of first found. --noprofile turns this off.
6094 * bash also sources ~/.bash_logout on exit.
6095 * If called as sh, skips .bash_XXX files.
6102 * "bash <script>" (which is never interactive (unless -i?))
6103 * sources $BASH_ENV here (without scanning $PATH).
6104 * If called as sh, does the same but with $ENV.
6106 debug_printf("running script '%s'\n", argv[optind]);
6107 G.global_argv = argv + optind;
6108 G.global_argc = argc - optind;
6109 input = xfopen_for_read(argv[optind]);
6110 close_on_exec_on(fileno(input));
6111 if (!signal_mask_is_inited)
6112 block_signals(0); /* 0: called 1st time */
6113 parse_and_run_file(input);
6114 #if ENABLE_FEATURE_CLEAN_UP
6120 /* Up to here, shell was non-interactive. Now it may become one.
6121 * NB: don't forget to (re)run block_signals(0/1) as needed.
6124 /* A shell is interactive if the '-i' flag was given, or if all of
6125 * the following conditions are met:
6127 * no arguments remaining or the -s flag given
6128 * standard input is a terminal
6129 * standard output is a terminal
6130 * Refer to Posix.2, the description of the 'sh' utility.
6133 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6134 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6135 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6136 //TODO: "interactive" and "have job control" are two different things.
6137 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6138 //should stay on! Currently, we mix these into one.
6139 if (G.saved_tty_pgrp >= 0) {
6140 /* try to dup stdin to high fd#, >= 255 */
6141 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6142 if (G_interactive_fd < 0) {
6143 /* try to dup to any fd */
6144 G_interactive_fd = dup(STDIN_FILENO);
6145 if (G_interactive_fd < 0)
6147 G_interactive_fd = 0;
6149 // TODO: track & disallow any attempts of user
6150 // to (inadvertently) close/redirect it
6153 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6154 if (G_interactive_fd) {
6157 /* We are indeed interactive shell, and we will perform
6158 * job control. Setting up for that. */
6160 close_on_exec_on(G_interactive_fd);
6161 /* If we were run as 'hush &', sleep until we are
6162 * in the foreground (tty pgrp == our pgrp).
6163 * If we get started under a job aware app (like bash),
6164 * make sure we are now in charge so we don't fight over
6165 * who gets the foreground */
6167 shell_pgrp = getpgrp();
6168 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6169 if (G.saved_tty_pgrp == shell_pgrp)
6171 /* send TTIN to ourself (should stop us) */
6172 kill(- shell_pgrp, SIGTTIN);
6174 /* Block some signals */
6175 block_signals(signal_mask_is_inited);
6176 /* Set other signals to restore saved_tty_pgrp */
6177 set_fatal_handlers();
6178 /* Put ourselves in our own process group */
6179 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6180 /* Grab control of the terminal */
6181 tcsetpgrp(G_interactive_fd, getpid());
6182 /* -1 is special - makes xfuncs longjmp, not exit
6183 * (we reset die_sleep = 0 whereever we [v]fork) */
6184 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6185 } else if (!signal_mask_is_inited) {
6186 block_signals(0); /* 0: called 1st time */
6187 } /* else: block_signals(0) was done before */
6188 #elif ENABLE_HUSH_INTERACTIVE
6189 /* No job control compiled in, only prompt/line editing */
6190 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6191 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6192 if (G_interactive_fd < 0) {
6193 /* try to dup to any fd */
6194 G_interactive_fd = dup(STDIN_FILENO);
6195 if (G_interactive_fd < 0)
6197 G_interactive_fd = 0;
6200 if (G_interactive_fd) {
6201 close_on_exec_on(G_interactive_fd);
6202 block_signals(signal_mask_is_inited);
6203 } else if (!signal_mask_is_inited) {
6207 /* We have interactiveness code disabled */
6208 if (!signal_mask_is_inited) {
6213 * if interactive but not a login shell, sources ~/.bashrc
6214 * (--norc turns this off, --rcfile <file> overrides)
6217 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6218 printf("\n\n%s hush - the humble shell\n", bb_banner);
6219 printf("Enter 'help' for a list of built-in commands.\n\n");
6222 parse_and_run_file(stdin);
6225 #if ENABLE_FEATURE_CLEAN_UP
6226 if (G.cwd != bb_msg_unknown)
6228 cur_var = G.top_var->next;
6230 struct variable *tmp = cur_var;
6231 if (!cur_var->max_len)
6232 free(cur_var->varstr);
6233 cur_var = cur_var->next;
6237 hush_exit(G.last_exitcode);
6242 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6243 int lash_main(int argc, char **argv)
6245 //bb_error_msg("lash is deprecated, please use hush instead");
6246 return hush_main(argc, argv);
6254 static int builtin_trap(char **argv)
6261 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6265 /* No args: print all trapped. This isn't 100% correct as we
6266 * should be escaping the cmd so that it can be pasted back in
6268 for (i = 0; i < NSIG; ++i)
6270 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6271 return EXIT_SUCCESS;
6276 /* If first arg is decimal: reset all specified signals */
6277 sig = bb_strtou(*argv, NULL, 10);
6283 sig = get_signum(*argv++);
6284 if (sig < 0 || sig >= NSIG) {
6286 /* Mimic bash message exactly */
6287 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6292 G.traps[sig] = xstrdup(new_cmd);
6294 debug_printf("trap: setting SIG%s (%i) to '%s'",
6295 get_signame(sig), sig, G.traps[sig]);
6297 /* There is no signal for 0 (EXIT) */
6302 sigaddset(&G.blocked_set, sig);
6304 /* There was a trap handler, we are removing it
6305 * (if sig has non-DFL handling,
6306 * we don't need to do anything) */
6307 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6309 sigdelset(&G.blocked_set, sig);
6311 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6316 /* First arg is "-": reset all specified to default */
6317 /* First arg is "": ignore all specified */
6318 /* Everything else: execute first arg upon signal */
6320 bb_error_msg("trap: invalid arguments");
6321 return EXIT_FAILURE;
6323 if (NOT_LONE_DASH(*argv))
6329 static int builtin_true(char **argv UNUSED_PARAM)
6334 static int builtin_test(char **argv)
6341 return test_main(argc, argv - argc);
6344 static int builtin_echo(char **argv)
6351 return echo_main(argc, argv - argc);
6354 static int builtin_eval(char **argv)
6356 int rcode = EXIT_SUCCESS;
6359 char *str = expand_strvec_to_string(argv);
6361 * eval "echo Hi; done" ("done" is syntax error):
6362 * "echo Hi" will not execute too.
6364 parse_and_run_string(str);
6366 rcode = G.last_exitcode;
6371 static int builtin_cd(char **argv)
6373 const char *newdir = argv[1];
6374 if (newdir == NULL) {
6375 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6376 * bash says "bash: cd: HOME not set" and does nothing
6379 newdir = getenv("HOME") ? : "/";
6381 if (chdir(newdir)) {
6382 /* Mimic bash message exactly */
6383 bb_perror_msg("cd: %s", newdir);
6384 return EXIT_FAILURE;
6387 return EXIT_SUCCESS;
6390 static int builtin_exec(char **argv)
6392 if (*++argv == NULL)
6393 return EXIT_SUCCESS; /* bash does this */
6398 /* TODO: if exec fails, bash does NOT exit! We do... */
6399 pseudo_exec_argv(&dummy, argv, 0, NULL);
6404 static int builtin_exit(char **argv)
6406 debug_printf_exec("%s()\n", __func__);
6408 /* interactive bash:
6409 * # trap "echo EEE" EXIT
6412 * There are stopped jobs.
6413 * (if there are _stopped_ jobs, running ones don't count)
6416 # EEE (then bash exits)
6418 * we can use G.exiting = -1 as indicator "last cmd was exit"
6421 /* note: EXIT trap is run by hush_exit */
6422 if (*++argv == NULL)
6423 hush_exit(G.last_exitcode);
6424 /* mimic bash: exit 123abc == exit 255 + error msg */
6425 xfunc_error_retval = 255;
6426 /* bash: exit -2 == exit 254, no error msg */
6427 hush_exit(xatoi(*argv) & 0xff);
6430 static int builtin_export(char **argv)
6432 if (*++argv == NULL) {
6439 /* ash emits: export VAR='VAL'
6440 * bash: declare -x VAR="VAL"
6441 * we follow ash example */
6442 const char *s = *e++;
6443 const char *p = strchr(s, '=');
6445 if (!p) /* wtf? take next variable */
6448 printf("export %.*s", (int)(p - s) + 1, s);
6452 p = strchrnul(s, '\'');
6454 printf("'%.*s'", (int)(p - s), s);
6459 /* s points to '; print ''...'''" */
6461 do putchar('\''); while (*++s == '\'');
6469 return EXIT_SUCCESS;
6476 value = strchr(name, '=');
6478 /* They are exporting something without a =VALUE */
6479 struct variable *var;
6481 var = get_local_var(name);
6483 var->flg_export = 1;
6484 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6485 putenv(var->varstr);
6487 /* bash does not return an error when trying to export
6488 * an undefined variable. Do likewise. */
6491 set_local_var(xstrdup(name), 1, 0);
6494 return EXIT_SUCCESS;
6498 /* built-in 'fg' and 'bg' handler */
6499 static int builtin_fg_bg(char **argv)
6504 if (!G_interactive_fd)
6505 return EXIT_FAILURE;
6506 /* If they gave us no args, assume they want the last backgrounded task */
6508 for (pi = G.job_list; pi; pi = pi->next) {
6509 if (pi->jobid == G.last_jobid) {
6513 bb_error_msg("%s: no current job", argv[0]);
6514 return EXIT_FAILURE;
6516 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6517 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6518 return EXIT_FAILURE;
6520 for (pi = G.job_list; pi; pi = pi->next) {
6521 if (pi->jobid == jobnum) {
6525 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6526 return EXIT_FAILURE;
6528 /* TODO: bash prints a string representation
6529 * of job being foregrounded (like "sleep 1 | cat") */
6530 if (argv[0][0] == 'f') {
6531 /* Put the job into the foreground. */
6532 tcsetpgrp(G_interactive_fd, pi->pgrp);
6535 /* Restart the processes in the job */
6536 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6537 for (i = 0; i < pi->num_cmds; i++) {
6538 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6539 pi->cmds[i].is_stopped = 0;
6541 pi->stopped_cmds = 0;
6543 i = kill(- pi->pgrp, SIGCONT);
6545 if (errno == ESRCH) {
6546 delete_finished_bg_job(pi);
6547 return EXIT_SUCCESS;
6549 bb_perror_msg("kill (SIGCONT)");
6552 if (argv[0][0] == 'f') {
6554 return checkjobs_and_fg_shell(pi);
6556 return EXIT_SUCCESS;
6560 #if ENABLE_HUSH_HELP
6561 static int builtin_help(char **argv UNUSED_PARAM)
6563 const struct built_in_command *x;
6566 "Built-in commands:\n"
6567 "------------------\n");
6568 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6569 printf("%s\t%s\n", x->cmd, x->descr);
6572 return EXIT_SUCCESS;
6577 static int builtin_jobs(char **argv UNUSED_PARAM)
6580 const char *status_string;
6582 for (job = G.job_list; job; job = job->next) {
6583 if (job->alive_cmds == job->stopped_cmds)
6584 status_string = "Stopped";
6586 status_string = "Running";
6588 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6590 return EXIT_SUCCESS;
6595 static int builtin_memleak(char **argv UNUSED_PARAM)
6600 /* Crude attempt to find where "free memory" starts,
6601 * sans fragmentation. */
6603 l = (unsigned long)p;
6606 if (l < (unsigned long)p) l = (unsigned long)p;
6609 if (!G.memleak_value)
6610 G.memleak_value = l;
6612 l -= G.memleak_value;
6619 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6624 static int builtin_pwd(char **argv UNUSED_PARAM)
6627 return EXIT_SUCCESS;
6630 static int builtin_read(char **argv)
6633 const char *name = "REPLY";
6637 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6638 * and _after_ that_ it will complain */
6639 if (!is_well_formed_var_name(name, '\0')) {
6640 /* Mimic bash message */
6641 bb_error_msg("read: '%s': not a valid identifier", name);
6646 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6648 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6649 return set_local_var(string, 0, 0);
6652 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6653 * built-in 'set' handler
6655 * set [-abCefhmnuvx] [-o option] [argument...]
6656 * set [+abCefhmnuvx] [+o option] [argument...]
6657 * set -- [argument...]
6660 * Implementations shall support the options in both their hyphen and
6661 * plus-sign forms. These options can also be specified as options to sh.
6663 * Write out all variables and their values: set
6664 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6665 * Turn on the -x and -v options: set -xv
6666 * Unset all positional parameters: set --
6667 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6668 * Set the positional parameters to the expansion of x, even if x expands
6669 * with a leading '-' or '+': set -- $x
6671 * So far, we only support "set -- [argument...]" and some of the short names.
6673 static int builtin_set(char **argv)
6676 char **pp, **g_argv;
6677 char *arg = *++argv;
6681 for (e = G.top_var; e; e = e->next)
6683 return EXIT_SUCCESS;
6687 if (!strcmp(arg, "--")) {
6691 if (arg[0] != '+' && arg[0] != '-')
6693 for (n = 1; arg[n]; ++n)
6694 if (set_mode(arg[0], arg[n]))
6696 } while ((arg = *++argv) != NULL);
6697 /* Now argv[0] is 1st argument */
6700 return EXIT_SUCCESS;
6703 /* NB: G.global_argv[0] ($0) is never freed/changed */
6704 g_argv = G.global_argv;
6705 if (G.global_args_malloced) {
6711 G.global_args_malloced = 1;
6712 pp = xzalloc(sizeof(pp[0]) * 2);
6713 pp[0] = g_argv[0]; /* retain $0 */
6716 /* This realloc's G.global_argv */
6717 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6724 return EXIT_SUCCESS;
6726 /* Nothing known, so abort */
6728 bb_error_msg("set: %s: invalid option", arg);
6729 return EXIT_FAILURE;
6732 static int builtin_shift(char **argv)
6738 if (n >= 0 && n < G.global_argc) {
6739 if (G.global_args_malloced) {
6742 free(G.global_argv[m++]);
6745 memmove(&G.global_argv[1], &G.global_argv[n+1],
6746 G.global_argc * sizeof(G.global_argv[0]));
6747 return EXIT_SUCCESS;
6749 return EXIT_FAILURE;
6752 static int builtin_source(char **argv)
6758 if (*++argv == NULL)
6759 return EXIT_FAILURE;
6761 // TODO: search through $PATH is missing
6762 input = fopen_or_warn(*argv, "r");
6764 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6765 return EXIT_FAILURE;
6767 close_on_exec_on(fileno(input));
6769 sv_flg = G.flag_return_in_progress;
6770 /* "we are inside sourced file, ok to use return" */
6771 G.flag_return_in_progress = -1;
6772 save_and_replace_G_args(&sv, argv);
6774 parse_and_run_file(input);
6777 restore_G_args(&sv, argv);
6778 G.flag_return_in_progress = sv_flg;
6780 return G.last_exitcode;
6783 static int builtin_umask(char **argv)
6790 mode_t old_mask = mask;
6793 rc = bb_parse_mode(argv[1], &mask);
6798 * bash: umask: 'q': invalid symbolic mode operator
6799 * bash: umask: 999: octal number out of range
6801 bb_error_msg("%s: '%s' invalid mode", argv[0], argv[1]);
6806 printf("%04o\n", (unsigned) mask);
6807 /* fall through and restore mask which we set to 0 */
6811 return !rc; /* rc != 0 - success */
6814 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6815 static int builtin_unset(char **argv)
6822 return EXIT_SUCCESS;
6825 while ((arg = *argv) != NULL && arg[0] == '-') {
6830 if (var == 0 || var == *arg) {
6834 /* else: unset -vf, which is illegal.
6837 bb_error_msg("unset: %s: invalid option", *argv);
6838 return EXIT_FAILURE;
6847 if (unset_local_var(*argv)) {
6848 /* unset <nonexistent_var> doesn't fail.
6849 * Error is when one tries to unset RO var.
6850 * Message was printed by unset_local_var. */
6854 #if ENABLE_HUSH_FUNCTIONS
6864 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6865 static int builtin_wait(char **argv)
6867 int ret = EXIT_SUCCESS;
6870 if (*++argv == NULL) {
6871 /* Don't care about wait results */
6872 /* Note 1: must wait until there are no more children */
6873 /* Note 2: must be interruptible */
6875 * $ sleep 3 & sleep 6 & wait
6880 * $ sleep 3 & sleep 6 & wait
6884 * ^C <-- after ~4 sec from keyboard
6887 sigaddset(&G.blocked_set, SIGCHLD);
6888 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6891 if (errno == ECHILD)
6893 /* Wait for SIGCHLD or any other signal of interest */
6894 /* sigtimedwait with infinite timeout: */
6895 sig = sigwaitinfo(&G.blocked_set, NULL);
6897 sig = check_and_run_traps(sig);
6898 if (sig && sig != SIGCHLD) { /* see note 2 */
6904 sigdelset(&G.blocked_set, SIGCHLD);
6905 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6909 /* This is probably buggy wrt interruptible-ness */
6911 pid_t pid = bb_strtou(*argv, NULL, 10);
6913 /* mimic bash message */
6914 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6915 return EXIT_FAILURE;
6917 if (waitpid(pid, &status, 0) == pid) {
6918 if (WIFSIGNALED(status))
6919 ret = 128 + WTERMSIG(status);
6920 else if (WIFEXITED(status))
6921 ret = WEXITSTATUS(status);
6925 bb_perror_msg("wait %s", *argv);
6934 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
6935 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
6938 def = bb_strtou(argv[1], NULL, 10);
6939 if (errno || def < def_min || argv[2]) {
6940 bb_error_msg("%s: bad arguments", argv[0]);
6948 #if ENABLE_HUSH_LOOPS
6949 static int builtin_break(char **argv)
6952 if (G.depth_of_loop == 0) {
6953 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6954 return EXIT_SUCCESS; /* bash compat */
6956 G.flag_break_continue++; /* BC_BREAK = 1 */
6958 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
6959 if (depth == UINT_MAX)
6960 G.flag_break_continue = BC_BREAK;
6961 if (G.depth_of_loop < depth)
6962 G.depth_break_continue = G.depth_of_loop;
6964 return EXIT_SUCCESS;
6967 static int builtin_continue(char **argv)
6969 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6970 return builtin_break(argv);
6974 #if ENABLE_HUSH_FUNCTIONS
6975 static int builtin_return(char **argv)
6979 if (G.flag_return_in_progress != -1) {
6980 bb_error_msg("%s: not in a function or sourced script", argv[0]);
6981 return EXIT_FAILURE; /* bash compat */
6984 G.flag_return_in_progress = 1;
6987 * out of range: wraps around at 256, does not error out
6988 * non-numeric param:
6989 * f() { false; return qwe; }; f; echo $?
6990 * bash: return: qwe: numeric argument required <== we do this
6991 * 255 <== we also do this
6993 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);