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"
55 * builtins: return, ulimit
56 * follow IFS rules more precisely, including update semantics
57 * figure out what to do with backslash-newline
58 * continuation lines, both explicit and implicit - done?
60 * separate job control from interactiveness
61 * (testcase: booting with init=/bin/hush does not show prompt (2009-04))
63 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
65 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
67 /* #include <dmalloc.h> */
74 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
78 /* Debug build knobs */
79 #define LEAK_HUNTING 0
80 #define BUILD_AS_NOMMU 0
81 /* Enable/disable sanity checks. Ok to enable in production,
82 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
83 * Keeping 1 for now even in released versions.
93 # define USE_FOR_NOMMU(...) __VA_ARGS__
94 # define USE_FOR_MMU(...)
97 #if defined SINGLE_APPLET_MAIN
98 /* STANDALONE does not make sense, and won't compile */
99 # undef CONFIG_FEATURE_SH_STANDALONE
100 # undef ENABLE_FEATURE_SH_STANDALONE
101 # undef USE_FEATURE_SH_STANDALONE
102 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
103 # define ENABLE_FEATURE_SH_STANDALONE 0
104 # define USE_FEATURE_SH_STANDALONE(...)
105 # define SKIP_FEATURE_SH_STANDALONE(...) __VA_ARGS__
108 #if !ENABLE_HUSH_INTERACTIVE
109 # undef ENABLE_FEATURE_EDITING
110 # define ENABLE_FEATURE_EDITING 0
111 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
112 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
115 /* Do we support ANY keywords? */
116 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
117 # define HAS_KEYWORDS 1
118 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
119 # define IF_HAS_NO_KEYWORDS(...)
121 # define HAS_KEYWORDS 0
122 # define IF_HAS_KEYWORDS(...)
123 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
126 /* If you comment out one of these below, it will be #defined later
127 * to perform debug printfs to stderr: */
128 #define debug_printf(...) do {} while (0)
129 /* Finer-grained debug switches */
130 #define debug_printf_parse(...) do {} while (0)
131 #define debug_print_tree(a, b) do {} while (0)
132 #define debug_printf_exec(...) do {} while (0)
133 #define debug_printf_env(...) do {} while (0)
134 #define debug_printf_jobs(...) do {} while (0)
135 #define debug_printf_expand(...) do {} while (0)
136 #define debug_printf_glob(...) do {} while (0)
137 #define debug_printf_list(...) do {} while (0)
138 #define debug_printf_subst(...) do {} while (0)
139 #define debug_printf_clean(...) do {} while (0)
141 #define ERR_PTR ((void*)(long)1)
143 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
145 #define SPECIAL_VAR_SYMBOL 3
147 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
149 /* This supports saving pointers malloced in vfork child,
150 * to be freed in the parent.
153 typedef struct nommu_save_t {
157 char **argv_from_re_execing;
161 /* The descrip member of this structure is only used to make
162 * debugging output pretty */
163 static const struct {
165 signed char default_fd;
169 { O_RDONLY, 0, "<" },
170 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
171 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
172 { O_RDONLY, 0, "<<" },
173 { O_CREAT|O_RDWR, 1, "<>" },
174 /* Should not be needed. Bogus default_fd helps in debugging */
175 /* { O_RDONLY, 77, "<<" }, */
178 typedef enum reserved_style {
187 #if ENABLE_HUSH_LOOPS
194 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
199 /* two pseudo-keywords support contrived "case" syntax: */
200 RES_MATCH , /* "word)" */
201 RES_CASEI , /* "this command is inside CASE" */
208 typedef struct o_string {
210 int length; /* position where data is appended */
212 /* Protect newly added chars against globbing
213 * (by prepending \ to *, ?, [, \) */
216 /* At least some part of the string was inside '' or "",
217 * possibly empty one: word"", wo''rd etc. */
219 smallint has_empty_slot;
220 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
223 MAYBE_ASSIGNMENT = 0,
224 DEFINITELY_ASSIGNMENT = 1,
226 WORD_IS_KEYWORD = 3, /* not assigment, but next word may be: "if v=xyz cmd;" */
228 /* Used for initialization: o_string foo = NULL_O_STRING; */
229 #define NULL_O_STRING { NULL }
231 /* I can almost use ordinary FILE*. Is open_memstream() universally
232 * available? Where is it documented? */
233 typedef struct in_str {
235 /* eof_flag=1: last char in ->p is really an EOF */
236 char eof_flag; /* meaningless if ->p == NULL */
238 #if ENABLE_HUSH_INTERACTIVE
240 smallint promptmode; /* 0: PS1, 1: PS2 */
243 int (*get) (struct in_str *);
244 int (*peek) (struct in_str *);
246 #define i_getch(input) ((input)->get(input))
247 #define i_peek(input) ((input)->peek(input))
249 struct redir_struct {
250 struct redir_struct *next;
251 char *rd_filename; /* filename */
252 int rd_fd; /* fd to redirect */
253 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
255 smallint rd_type; /* (enum redir_type) */
256 /* note: for heredocs, rd_filename contains heredoc delimiter,
257 * and subsequently heredoc itself; and rd_dup is a bitmask:
258 * 1: do we need to trim leading tabs?
259 * 2: is heredoc quoted (<<'delim' syntax) ?
262 typedef enum redir_type {
263 REDIRECT_INVALID = 0,
265 REDIRECT_OVERWRITE = 2,
267 REDIRECT_HEREDOC = 4,
269 REDIRECT_HEREDOC2 = 6, /* REDIRECT_HEREDOC after heredoc is loaded */
272 REDIRFD_SYNTAX_ERR = -2,
273 REDIRFD_TO_FILE = -1,
274 /* otherwise, rd_fd is redirected to rd_dup */
276 HEREDOC_SKIPTABS = 1,
282 pid_t pid; /* 0 if exited */
283 int assignment_cnt; /* how many argv[i] are assignments? */
284 smallint is_stopped; /* is the command currently running? */
285 smallint grp_type; /* GRP_xxx */
287 #define GRP_SUBSHELL 1
288 #if ENABLE_HUSH_FUNCTIONS
289 # define GRP_FUNCTION 2
291 struct pipe *group; /* if non-NULL, this "command" is { list },
292 * ( list ), or a compound statement */
294 char *group_as_string;
296 #if ENABLE_HUSH_FUNCTIONS
297 struct function *child_func;
298 /* This field is used to prevent a bug here:
299 * while...do f1() {a;}; f1; f1 {b;}; f1; done
300 * When we execute "f1() {a;}" cmd, we create new function and clear
301 * cmd->group, cmd->group_as_string, cmd->argv[0].
302 * when we execute "f1 {b;}", we notice that f1 exists,
303 * and that it's "parent cmd" struct is still "alive",
304 * we put those fields back into cmd->xxx
305 * (struct function has ->parent_cmd ptr to facilitate that).
306 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
307 * Without this trick, loop would execute a;b;b;b;...
308 * instead of correct sequence a;b;a;b;...
309 * When command is freed, it severs the link
310 * (sets ->child_func->parent_cmd to NULL).
313 char **argv; /* command name and arguments */
314 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
315 * and on execution these are substituted with their values.
316 * Substitution can make _several_ words out of one argv[n]!
317 * Example: argv[0]=='.^C*^C.' here: echo .$*.
318 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
320 struct redir_struct *redirects; /* I/O redirections */
322 /* Is there anything in this command at all? */
323 #define IS_NULL_CMD(cmd) \
324 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
329 int num_cmds; /* total number of commands in pipe */
330 int alive_cmds; /* number of commands running (not exited) */
331 int stopped_cmds; /* number of commands alive, but stopped */
333 int jobid; /* job number */
334 pid_t pgrp; /* process group ID for the job */
335 char *cmdtext; /* name of job */
337 struct command *cmds; /* array of commands in pipe */
338 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
339 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
340 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
342 typedef enum pipe_style {
348 /* Is there anything in this pipe at all? */
349 #define IS_NULL_PIPE(pi) \
350 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
352 /* This holds pointers to the various results of parsing */
353 struct parse_context {
354 /* linked list of pipes */
355 struct pipe *list_head;
356 /* last pipe (being constructed right now) */
358 /* last command in pipe (being constructed right now) */
359 struct command *command;
360 /* last redirect in command->redirects list */
361 struct redir_struct *pending_redirect;
367 smallint ctx_inverted; /* "! cmd | cmd" */
369 smallint ctx_dsemicolon; /* ";;" seen */
371 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
373 /* group we are enclosed in:
374 * example: "if pipe1; pipe2; then pipe3; fi"
375 * when we see "if" or "then", we malloc and copy current context,
376 * and make ->stack point to it. then we parse pipeN.
377 * when closing "then" / fi" / whatever is found,
378 * we move list_head into ->stack->command->group,
379 * copy ->stack into current context, and delete ->stack.
380 * (parsing of { list } and ( list ) doesn't use this method)
382 struct parse_context *stack;
386 /* On program start, environ points to initial environment.
387 * putenv adds new pointers into it, unsetenv removes them.
388 * Neither of these (de)allocates the strings.
389 * setenv allocates new strings in malloc space and does putenv,
390 * and thus setenv is unusable (leaky) for shell's purposes */
391 #define setenv(...) setenv_is_leaky_dont_use()
393 struct variable *next;
394 char *varstr; /* points to "name=" portion */
395 int max_len; /* if > 0, name is part of initial env; else name is malloced */
396 smallint flg_export; /* putenv should be done on this var */
397 smallint flg_read_only;
405 #if ENABLE_HUSH_FUNCTIONS
407 struct function *next;
409 struct command *parent_cmd;
412 char *body_as_string;
418 /* "Globals" within this file */
419 /* Sorted roughly by size (smaller offsets == smaller code) */
421 #if ENABLE_HUSH_INTERACTIVE
422 /* 'interactive_fd' is a fd# open to ctty, if we have one
423 * _AND_ if we decided to act interactively */
427 #define G_interactive_fd (G.interactive_fd)
429 #define G_interactive_fd 0
431 #if ENABLE_FEATURE_EDITING
432 line_input_t *line_input_state;
438 pid_t saved_tty_pgrp;
440 struct pipe *job_list;
441 struct pipe *toplevel_list;
443 smallint flag_SIGINT;
444 #if ENABLE_HUSH_LOOPS
445 smallint flag_break_continue;
447 #if ENABLE_HUSH_FUNCTIONS
448 /* 0: outside of a function (or sourced file)
449 * -1: inside of a function, ok to use return builtin
450 * 1: return is invoked, skip all till end of func.
452 smallint flag_return_in_progress;
455 smallint exiting; /* used to prevent EXIT trap recursion */
456 /* These four support $?, $#, and $1 */
457 smalluint last_exitcode;
458 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
459 smalluint global_args_malloced;
460 /* how many non-NULL argv's we have. NB: $# + 1 */
464 char *argv0_for_re_execing;
466 #if ENABLE_HUSH_LOOPS
467 unsigned depth_break_continue;
468 unsigned depth_of_loop;
472 struct variable *top_var; /* = &G.shell_ver (set in main()) */
473 struct variable shell_ver;
474 #if ENABLE_HUSH_FUNCTIONS
475 struct function *top_func;
477 /* Signal and trap handling */
478 // unsigned count_SIGCHLD;
479 // unsigned handled_SIGCHLD;
480 /* which signals have non-DFL handler (even with no traps set)? */
481 unsigned non_DFL_mask;
482 char **traps; /* char *traps[NSIG] */
483 sigset_t blocked_set;
484 sigset_t inherited_set;
486 unsigned long memleak_value;
489 char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
491 #define G (*ptr_to_globals)
492 /* Not #defining name to G.name - this quickly gets unwieldy
493 * (too many defines). Also, I actually prefer to see when a variable
494 * is global, thus "G." prefix is a useful hint */
495 #define INIT_G() do { \
496 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
500 /* Function prototypes for builtins */
501 static int builtin_cd(char **argv);
502 static int builtin_echo(char **argv);
503 static int builtin_eval(char **argv);
504 static int builtin_exec(char **argv);
505 static int builtin_exit(char **argv);
506 static int builtin_export(char **argv);
508 static int builtin_fg_bg(char **argv);
509 static int builtin_jobs(char **argv);
512 static int builtin_help(char **argv);
515 static int builtin_memleak(char **argv);
517 static int builtin_pwd(char **argv);
518 static int builtin_read(char **argv);
519 static int builtin_set(char **argv);
520 static int builtin_shift(char **argv);
521 static int builtin_source(char **argv);
522 static int builtin_test(char **argv);
523 static int builtin_trap(char **argv);
524 static int builtin_true(char **argv);
525 static int builtin_umask(char **argv);
526 static int builtin_unset(char **argv);
527 static int builtin_wait(char **argv);
528 #if ENABLE_HUSH_LOOPS
529 static int builtin_break(char **argv);
530 static int builtin_continue(char **argv);
532 #if ENABLE_HUSH_FUNCTIONS
533 static int builtin_return(char **argv);
536 /* Table of built-in functions. They can be forked or not, depending on
537 * context: within pipes, they fork. As simple commands, they do not.
538 * When used in non-forking context, they can change global variables
539 * in the parent shell process. If forked, of course they cannot.
540 * For example, 'unset foo | whatever' will parse and run, but foo will
541 * still be set at the end. */
542 struct built_in_command {
544 int (*function)(char **argv);
547 #define BLTIN(cmd, func, help) { cmd, func, help }
549 #define BLTIN(cmd, func, help) { cmd, func }
553 /* For now, echo and test are unconditionally enabled.
554 * Maybe make it configurable? */
555 static const struct built_in_command bltins[] = {
556 BLTIN("." , builtin_source , "Run commands in a file"),
557 BLTIN(":" , builtin_true , "No-op"),
558 BLTIN("[" , builtin_test , "Test condition"),
560 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
562 #if ENABLE_HUSH_LOOPS
563 BLTIN("break" , builtin_break , "Exit from a loop"),
565 BLTIN("cd" , builtin_cd , "Change directory"),
566 #if ENABLE_HUSH_LOOPS
567 BLTIN("continue", builtin_continue, "Start new loop iteration"),
569 BLTIN("echo" , builtin_echo , "Write to stdout"),
570 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
571 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
572 BLTIN("exit" , builtin_exit , "Exit"),
573 BLTIN("export" , builtin_export , "Set environment variable"),
575 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
578 BLTIN("help" , builtin_help , "List shell built-in commands"),
581 BLTIN("jobs" , builtin_jobs , "List active jobs"),
584 BLTIN("memleak" , builtin_memleak , "Debug tool"),
586 BLTIN("pwd" , builtin_pwd , "Print current directory"),
587 BLTIN("read" , builtin_read , "Input environment variable"),
588 #if ENABLE_HUSH_FUNCTIONS
589 BLTIN("return" , builtin_return , "Return from a function"),
591 BLTIN("set" , builtin_set , "Set/unset shell local variables"),
592 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
593 BLTIN("test" , builtin_test , "Test condition"),
594 BLTIN("trap" , builtin_trap , "Trap signals"),
595 // BLTIN("ulimit" , builtin_return , "Control resource limits"),
596 BLTIN("umask" , builtin_umask , "Set file creation mask"),
597 BLTIN("unset" , builtin_unset , "Unset environment variable"),
598 BLTIN("wait" , builtin_wait , "Wait for process"),
605 /* prevent disasters with G.debug_indent < 0 */
606 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
607 # define debug_enter() (G.debug_indent++)
608 # define debug_leave() (G.debug_indent--)
610 # define indent() ((void)0)
611 # define debug_enter() ((void)0)
612 # define debug_leave() ((void)0)
616 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
619 #ifndef debug_printf_parse
620 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
623 #ifndef debug_printf_exec
624 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
627 #ifndef debug_printf_env
628 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
631 #ifndef debug_printf_jobs
632 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
633 # define DEBUG_JOBS 1
635 # define DEBUG_JOBS 0
638 #ifndef debug_printf_expand
639 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
640 # define DEBUG_EXPAND 1
642 # define DEBUG_EXPAND 0
645 #ifndef debug_printf_glob
646 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
647 # define DEBUG_GLOB 1
649 # define DEBUG_GLOB 0
652 #ifndef debug_printf_list
653 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
656 #ifndef debug_printf_subst
657 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
660 #ifndef debug_printf_clean
661 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
662 # define DEBUG_CLEAN 1
664 # define DEBUG_CLEAN 0
668 static void debug_print_strings(const char *prefix, char **vv)
671 fprintf(stderr, "%s:\n", prefix);
673 fprintf(stderr, " '%s'\n", *vv++);
676 #define debug_print_strings(prefix, vv) ((void)0)
680 /* Leak hunting. Use hush_leaktool.sh for post-processing.
683 static void *xxmalloc(int lineno, size_t size)
685 void *ptr = xmalloc((size + 0xff) & ~0xff);
686 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
689 static void *xxrealloc(int lineno, void *ptr, size_t size)
691 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
692 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
695 static char *xxstrdup(int lineno, const char *str)
697 char *ptr = xstrdup(str);
698 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
701 static void xxfree(void *ptr)
703 fdprintf(2, "free %p\n", ptr);
706 #define xmalloc(s) xxmalloc(__LINE__, s)
707 #define xrealloc(p, s) xxrealloc(__LINE__, p, s)
708 #define xstrdup(s) xxstrdup(__LINE__, s)
709 #define free(p) xxfree(p)
713 /* Syntax and runtime errors. They always abort scripts.
714 * In interactive use they usually discard unparsed and/or unexecuted commands
715 * and return to the prompt.
716 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
719 # define die_if_script(lineno, fmt...) die_if_script(fmt)
720 # define syntax_error(lineno, msg) syntax_error(msg)
721 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
722 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
723 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
724 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
727 static void die_if_script(unsigned lineno, const char *fmt, ...)
732 bb_error_msg("hush.c:%u", lineno);
735 bb_verror_msg(fmt, p, NULL);
737 if (!G_interactive_fd)
741 static void syntax_error(unsigned lineno, const char *msg)
744 die_if_script(lineno, "syntax error: %s", msg);
746 die_if_script(lineno, "syntax error", NULL);
749 static void syntax_error_at(unsigned lineno, const char *msg)
751 die_if_script(lineno, "syntax error at '%s'", msg);
754 /* It so happens that all such cases are totally fatal
755 * even if shell is interactive: EOF while looking for closing
756 * delimiter. There is nowhere to read stuff from after that,
757 * it's EOF! The only choice is to terminate.
759 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
760 static void syntax_error_unterm_ch(unsigned lineno, char ch)
765 die_if_script(lineno, "syntax error: unterminated %s", msg);
769 static void syntax_error_unterm_str(unsigned lineno, const char *s)
771 die_if_script(lineno, "syntax error: unterminated %s", s);
774 static void syntax_error_unexpected_ch(unsigned lineno, char ch)
779 die_if_script(lineno, "syntax error: unexpected %s", msg);
783 # undef die_if_script
785 # undef syntax_error_at
786 # undef syntax_error_unterm_ch
787 # undef syntax_error_unterm_str
788 # undef syntax_error_unexpected_ch
790 # define die_if_script(fmt...) die_if_script(__LINE__, fmt)
791 # define syntax_error(msg) syntax_error(__LINE__, msg)
792 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
793 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
794 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
795 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
801 static int glob_needed(const char *s)
806 if (*s == '*' || *s == '[' || *s == '?')
813 static int is_well_formed_var_name(const char *s, char terminator)
815 if (!s || !(isalpha(*s) || *s == '_'))
818 while (isalnum(*s) || *s == '_')
820 return *s == terminator;
823 /* Replace each \x with x in place, return ptr past NUL. */
824 static char *unbackslash(char *src)
830 if ((*dst++ = *src++) == '\0')
836 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
857 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
858 v[count1 + count2] = NULL;
861 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
865 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
867 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
868 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
871 #define add_strings_to_strings(strings, add, need_to_dup) \
872 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
875 static char **add_string_to_strings(char **strings, char *add)
880 return add_strings_to_strings(strings, v, /*dup:*/ 0);
883 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
885 char **ptr = add_string_to_strings(strings, add);
886 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
889 #define add_string_to_strings(strings, add) \
890 xx_add_string_to_strings(__LINE__, strings, add)
893 static void putenv_all(char **strings)
898 debug_printf_env("putenv '%s'\n", *strings);
903 static char **putenv_all_and_save_old(char **strings)
913 eq = strchr(*strings, '=');
916 v = getenv(*strings);
919 /* v points to VAL in VAR=VAL, go back to VAR */
920 v -= (eq - *strings) + 1;
921 old = add_string_to_strings(old, v);
930 static void free_strings_and_unsetenv(char **strings, int unset)
940 debug_printf_env("unsetenv '%s'\n", *v);
948 static void free_strings(char **strings)
950 free_strings_and_unsetenv(strings, 0);
954 /* Helpers for setting new $n and restoring them back
956 typedef struct save_arg_t {
960 smallint sv_g_malloced;
963 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
967 sv->sv_argv0 = argv[0];
968 sv->sv_g_argv = G.global_argv;
969 sv->sv_g_argc = G.global_argc;
970 sv->sv_g_malloced = G.global_args_malloced;
972 argv[0] = G.global_argv[0]; /* retain $0 */
973 G.global_argv = argv;
974 G.global_args_malloced = 0;
982 static void restore_G_args(save_arg_t *sv, char **argv)
986 if (G.global_args_malloced) {
987 /* someone ran "set -- arg1 arg2 ...", undo */
989 while (*++pp) /* note: does not free $0 */
993 argv[0] = sv->sv_argv0;
994 G.global_argv = sv->sv_g_argv;
995 G.global_argc = sv->sv_g_argc;
996 G.global_args_malloced = sv->sv_g_malloced;
1000 /* Basic theory of signal handling in shell
1001 * ========================================
1002 * This does not describe what hush does, rather, it is current understanding
1003 * what it _should_ do. If it doesn't, it's a bug.
1004 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1006 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1007 * is finished or backgrounded. It is the same in interactive and
1008 * non-interactive shells, and is the same regardless of whether
1009 * a user trap handler is installed or a shell special one is in effect.
1010 * ^C or ^Z from keyboard seem to execute "at once" because it usually
1011 * backgrounds (i.e. stops) or kills all members of currently running
1014 * Wait builtin in interruptible by signals for which user trap is set
1015 * or by SIGINT in interactive shell.
1017 * Trap handlers will execute even within trap handlers. (right?)
1019 * User trap handlers are forgotten when subshell ("(cmd)") is entered.
1021 * If job control is off, backgrounded commands ("cmd &")
1022 * have SIGINT, SIGQUIT set to SIG_IGN.
1024 * Commands run in command substitution ("`cmd`")
1025 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1027 * Ordinary commands have signals set to SIG_IGN/DFL set as inherited
1028 * by the shell from its parent.
1030 * Siganls which differ from SIG_DFL action
1031 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1034 * SIGTERM (interactive): ignore
1035 * SIGHUP (interactive):
1036 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1037 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1038 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1039 * that all pipe members are stopped. Try this in bash:
1040 * while :; do :; done - ^Z does not background it
1041 * (while :; do :; done) - ^Z backgrounds it
1042 * SIGINT (interactive): wait for last pipe, ignore the rest
1043 * of the command line, show prompt. NB: ^C does not send SIGINT
1044 * to interactive shell while shell is waiting for a pipe,
1045 * since shell is bg'ed (is not in foreground process group).
1046 * Example 1: this waits 5 sec, but does not execute ls:
1047 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1048 * Example 2: this does not wait and does not execute ls:
1049 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1050 * Example 3: this does not wait 5 sec, but executes ls:
1051 * "sleep 5; ls -l" + press ^C
1053 * (What happens to signals which are IGN on shell start?)
1054 * (What happens with signal mask on shell start?)
1056 * Implementation in hush
1057 * ======================
1058 * We use in-kernel pending signal mask to determine which signals were sent.
1059 * We block all signals which we don't want to take action immediately,
1060 * i.e. we block all signals which need to have special handling as described
1061 * above, and all signals which have traps set.
1062 * After each pipe execution, we extract any pending signals via sigtimedwait()
1065 * unsigned non_DFL_mask: a mask of such "special" signals
1066 * sigset_t blocked_set: current blocked signal set
1069 * clear bit in blocked_set unless it is also in non_DFL_mask
1070 * "trap 'cmd' SIGxxx":
1071 * set bit in blocked_set (even if 'cmd' is '')
1072 * after [v]fork, if we plan to be a shell:
1073 * nothing for {} child shell (say, "true | { true; true; } | true")
1074 * unset all traps if () shell.
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)
1089 //TODO | (1 << SIGHUP)
1093 //static void SIGCHLD_handler(int sig UNUSED_PARAM)
1095 // G.count_SIGCHLD++;
1098 static int check_and_run_traps(int sig)
1100 static const struct timespec zero_timespec = { 0, 0 };
1101 smalluint save_rcode;
1107 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1112 if (G.traps && G.traps[sig]) {
1113 if (G.traps[sig][0]) {
1114 /* We have user-defined handler */
1115 char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
1116 save_rcode = G.last_exitcode;
1119 G.last_exitcode = save_rcode;
1120 } /* else: "" trap, ignoring signal */
1123 /* not a trap: special action */
1126 // G.count_SIGCHLD++;
1129 //TODO: add putchar('\n') also when we detect that child was killed (sleep 5 + ^C)
1130 /* Builtin was ^C'ed, make it look prettier: */
1137 default: /* ignored: */
1138 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1147 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1148 #define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1149 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1150 #define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1152 /* Restores tty foreground process group, and exits.
1153 * May be called as signal handler for fatal signal
1154 * (will faithfully resend signal to itself, producing correct exit state)
1155 * or called directly with -EXITCODE.
1156 * We also call it if xfunc is exiting. */
1157 static void sigexit(int sig) NORETURN;
1158 static void sigexit(int sig)
1160 /* Disable all signals: job control, SIGPIPE, etc. */
1161 sigprocmask_allsigs(SIG_BLOCK);
1163 /* Careful: we can end up here after [v]fork. Do not restore
1164 * tty pgrp then, only top-level shell process does that */
1165 if (G_interactive_fd && getpid() == G.root_pid)
1166 tcsetpgrp(G_interactive_fd, G.saved_tty_pgrp);
1168 /* Not a signal, just exit */
1172 kill_myself_with_sig(sig); /* does not return */
1176 #define disable_restore_tty_pgrp_on_exit() ((void)0)
1177 #define enable_restore_tty_pgrp_on_exit() ((void)0)
1181 /* Restores tty foreground process group, and exits. */
1182 static void hush_exit(int exitcode) NORETURN;
1183 static void hush_exit(int exitcode)
1185 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1186 /* Prevent recursion:
1187 * trap "echo Hi; exit" EXIT; exit
1189 char *argv[] = { NULL, G.traps[0], NULL };
1197 fflush(NULL); /* flush all streams */
1198 sigexit(- (exitcode & 0xff));
1205 static const char *set_cwd(void)
1207 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1208 * we must not try to free(bb_msg_unknown) */
1209 if (G.cwd == bb_msg_unknown)
1211 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1213 G.cwd = bb_msg_unknown;
1218 /* Get/check local shell variables */
1219 static struct variable *get_local_var(const char *name)
1221 struct variable *cur;
1227 for (cur = G.top_var; cur; cur = cur->next) {
1228 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1234 static const char *get_local_var_value(const char *src)
1236 struct variable *var = get_local_var(src);
1238 return strchr(var->varstr, '=') + 1;
1242 /* str holds "NAME=VAL" and is expected to be malloced.
1243 * We take ownership of it.
1247 * -1: if NAME is set, leave export status alone
1248 * if NAME is not set, do not export
1249 * flg_read_only is set only when we handle -R var=val
1252 #define set_local_var(str, flg_export, flg_read_only) \
1253 set_local_var(str, flg_export)
1255 static int set_local_var(char *str, int flg_export, int flg_read_only)
1257 struct variable *cur;
1261 value = strchr(str, '=');
1262 if (!value) { /* not expected to ever happen? */
1267 name_len = value - str + 1; /* including '=' */
1268 cur = G.top_var; /* cannot be NULL (we have HUSH_VERSION and it's RO) */
1270 if (strncmp(cur->varstr, str, name_len) != 0) {
1272 /* Bail out. Note that now cur points
1273 * to last var in linked list */
1279 /* We found an existing var with this name */
1281 if (cur->flg_read_only) {
1285 bb_error_msg("%s: readonly variable", str);
1289 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1290 unsetenv(str); /* just in case */
1292 if (strcmp(cur->varstr, str) == 0) {
1297 if (cur->max_len >= strlen(str)) {
1298 /* This one is from startup env, reuse space */
1299 strcpy(cur->varstr, str);
1302 /* max_len == 0 signifies "malloced" var, which we can
1303 * (and has to) free */
1307 goto set_str_and_exp;
1310 /* Not found - create next variable struct */
1311 cur->next = xzalloc(sizeof(*cur));
1317 cur->flg_read_only = flg_read_only;
1320 if (flg_export == 1)
1321 cur->flg_export = 1;
1322 if (cur->flg_export) {
1323 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1324 return putenv(cur->varstr);
1329 static int unset_local_var(const char *name)
1331 struct variable *cur;
1332 struct variable *prev = prev; /* for gcc */
1336 return EXIT_SUCCESS;
1337 name_len = strlen(name);
1340 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1341 if (cur->flg_read_only) {
1342 bb_error_msg("%s: readonly variable", name);
1343 return EXIT_FAILURE;
1345 /* prev is ok to use here because 1st variable, HUSH_VERSION,
1346 * is ro, and we cannot reach this code on the 1st pass */
1347 prev->next = cur->next;
1348 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1349 bb_unsetenv(cur->varstr);
1353 return EXIT_SUCCESS;
1358 return EXIT_SUCCESS;
1361 #if ENABLE_SH_MATH_SUPPORT
1362 #define is_name(c) ((c) == '_' || isalpha((unsigned char)(c)))
1363 #define is_in_name(c) ((c) == '_' || isalnum((unsigned char)(c)))
1364 static char *endofname(const char *name)
1372 if (!is_in_name(*p))
1378 static void arith_set_local_var(const char *name, const char *val, int flags)
1380 /* arith code doesnt malloc space, so do it for it */
1381 char *var = xasprintf("%s=%s", name, val);
1382 set_local_var(var, flags, 0);
1390 static int static_get(struct in_str *i)
1399 static int static_peek(struct in_str *i)
1404 #if ENABLE_HUSH_INTERACTIVE
1406 static void cmdedit_set_initial_prompt(void)
1408 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1409 G.PS1 = getenv("PS1");
1416 static const char* setup_prompt_string(int promptmode)
1418 const char *prompt_str;
1419 debug_printf("setup_prompt_string %d ", promptmode);
1420 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1421 /* Set up the prompt */
1422 if (promptmode == 0) { /* PS1 */
1424 G.PS1 = xasprintf("%s %c ", G.cwd, (geteuid() != 0) ? '$' : '#');
1429 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1430 debug_printf("result '%s'\n", prompt_str);
1434 static void get_user_input(struct in_str *i)
1437 const char *prompt_str;
1439 prompt_str = setup_prompt_string(i->promptmode);
1440 #if ENABLE_FEATURE_EDITING
1441 /* Enable command line editing only while a command line
1442 * is actually being read */
1445 /* buglet: SIGINT will not make new prompt to appear _at once_,
1446 * only after <Enter>. (^C will work) */
1447 r = read_line_input(prompt_str, G.user_input_buf, BUFSIZ-1, G.line_input_state);
1448 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1449 check_and_run_traps(0);
1450 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1451 i->eof_flag = (r < 0);
1452 if (i->eof_flag) { /* EOF/error detected */
1453 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1454 G.user_input_buf[1] = '\0';
1459 fputs(prompt_str, stdout);
1461 G.user_input_buf[0] = r = fgetc(i->file);
1462 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1463 //do we need check_and_run_traps(0)? (maybe only if stdin)
1464 } while (G.flag_SIGINT);
1465 i->eof_flag = (r == EOF);
1467 i->p = G.user_input_buf;
1470 #endif /* INTERACTIVE */
1472 /* This is the magic location that prints prompts
1473 * and gets data back from the user */
1474 static int file_get(struct in_str *i)
1478 /* If there is data waiting, eat it up */
1479 if (i->p && *i->p) {
1480 #if ENABLE_HUSH_INTERACTIVE
1484 if (i->eof_flag && !*i->p)
1486 /* note: ch is never NUL */
1488 /* need to double check i->file because we might be doing something
1489 * more complicated by now, like sourcing or substituting. */
1490 #if ENABLE_HUSH_INTERACTIVE
1491 if (G_interactive_fd && i->promptme && i->file == stdin) {
1494 } while (!*i->p); /* need non-empty line */
1495 i->promptmode = 1; /* PS2 */
1500 do ch = fgetc(i->file); while (ch == '\0');
1502 debug_printf("file_get: got '%c' %d\n", ch, ch);
1503 #if ENABLE_HUSH_INTERACTIVE
1510 /* All callers guarantee this routine will never
1511 * be used right after a newline, so prompting is not needed.
1513 static int file_peek(struct in_str *i)
1516 if (i->p && *i->p) {
1517 if (i->eof_flag && !i->p[1])
1520 /* note: ch is never NUL */
1522 do ch = fgetc(i->file); while (ch == '\0');
1523 i->eof_flag = (ch == EOF);
1524 i->peek_buf[0] = ch;
1525 i->peek_buf[1] = '\0';
1527 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1531 static void setup_file_in_str(struct in_str *i, FILE *f)
1533 i->peek = file_peek;
1535 #if ENABLE_HUSH_INTERACTIVE
1537 i->promptmode = 0; /* PS1 */
1543 static void setup_string_in_str(struct in_str *i, const char *s)
1545 i->peek = static_peek;
1546 i->get = static_get;
1547 #if ENABLE_HUSH_INTERACTIVE
1549 i->promptmode = 0; /* PS1 */
1559 #define B_CHUNK (32 * sizeof(char*))
1561 static void o_reset_to_empty_unquoted(o_string *o)
1569 static void o_free(o_string *o)
1572 memset(o, 0, sizeof(*o));
1575 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
1580 static void o_grow_by(o_string *o, int len)
1582 if (o->length + len > o->maxlen) {
1583 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
1584 o->data = xrealloc(o->data, 1 + o->maxlen);
1588 static void o_addchr(o_string *o, int ch)
1590 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
1592 o->data[o->length] = ch;
1594 o->data[o->length] = '\0';
1597 static void o_addblock(o_string *o, const char *str, int len)
1600 memcpy(&o->data[o->length], str, len);
1602 o->data[o->length] = '\0';
1606 static void o_addstr(o_string *o, const char *str)
1608 o_addblock(o, str, strlen(str));
1610 static void nommu_addchr(o_string *o, int ch)
1616 #define nommu_addchr(o, str) ((void)0)
1619 static void o_addstr_with_NUL(o_string *o, const char *str)
1621 o_addblock(o, str, strlen(str) + 1);
1624 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
1629 && (*str != '*' && *str != '?' && *str != '[')
1637 /* My analysis of quoting semantics tells me that state information
1638 * is associated with a destination, not a source.
1640 static void o_addqchr(o_string *o, int ch)
1643 char *found = strchr("*?[\\", ch);
1648 o->data[o->length] = '\\';
1651 o->data[o->length] = ch;
1653 o->data[o->length] = '\0';
1656 static void o_addQchr(o_string *o, int ch)
1659 if (o->o_escape && strchr("*?[\\", ch)) {
1661 o->data[o->length] = '\\';
1665 o->data[o->length] = ch;
1667 o->data[o->length] = '\0';
1670 static void o_addQstr(o_string *o, const char *str, int len)
1673 o_addblock(o, str, len);
1679 int ordinary_cnt = strcspn(str, "*?[\\");
1680 if (ordinary_cnt > len) /* paranoia */
1682 o_addblock(o, str, ordinary_cnt);
1683 if (ordinary_cnt == len)
1685 str += ordinary_cnt;
1686 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
1690 if (ch) { /* it is necessarily one of "*?[\\" */
1692 o->data[o->length] = '\\';
1696 o->data[o->length] = ch;
1698 o->data[o->length] = '\0';
1702 /* A special kind of o_string for $VAR and `cmd` expansion.
1703 * It contains char* list[] at the beginning, which is grown in 16 element
1704 * increments. Actual string data starts at the next multiple of 16 * (char*).
1705 * list[i] contains an INDEX (int!) into this string data.
1706 * It means that if list[] needs to grow, data needs to be moved higher up
1707 * but list[i]'s need not be modified.
1708 * NB: remembering how many list[i]'s you have there is crucial.
1709 * o_finalize_list() operation post-processes this structure - calculates
1710 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
1712 #if DEBUG_EXPAND || DEBUG_GLOB
1713 static void debug_print_list(const char *prefix, o_string *o, int n)
1715 char **list = (char**)o->data;
1716 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1720 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d\n",
1721 prefix, list, n, string_start, o->length, o->maxlen);
1724 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
1725 o->data + (int)list[i] + string_start,
1726 o->data + (int)list[i] + string_start);
1730 const char *p = o->data + (int)list[n - 1] + string_start;
1732 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
1736 #define debug_print_list(prefix, o, n) ((void)0)
1739 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
1740 * in list[n] so that it points past last stored byte so far.
1741 * It returns n+1. */
1742 static int o_save_ptr_helper(o_string *o, int n)
1744 char **list = (char**)o->data;
1748 if (!o->has_empty_slot) {
1749 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1750 string_len = o->length - string_start;
1751 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
1752 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
1753 /* list[n] points to string_start, make space for 16 more pointers */
1754 o->maxlen += 0x10 * sizeof(list[0]);
1755 o->data = xrealloc(o->data, o->maxlen + 1);
1756 list = (char**)o->data;
1757 memmove(list + n + 0x10, list + n, string_len);
1758 o->length += 0x10 * sizeof(list[0]);
1760 debug_printf_list("list[%d]=%d string_start=%d\n",
1761 n, string_len, string_start);
1764 /* We have empty slot at list[n], reuse without growth */
1765 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
1766 string_len = o->length - string_start;
1767 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
1768 n, string_len, string_start);
1769 o->has_empty_slot = 0;
1771 list[n] = (char*)(ptrdiff_t)string_len;
1775 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
1776 static int o_get_last_ptr(o_string *o, int n)
1778 char **list = (char**)o->data;
1779 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1781 return ((int)(ptrdiff_t)list[n-1]) + string_start;
1784 /* o_glob performs globbing on last list[], saving each result
1785 * as a new list[]. */
1786 static int o_glob(o_string *o, int n)
1792 debug_printf_glob("start o_glob: n:%d o->data:%p\n", n, o->data);
1794 return o_save_ptr_helper(o, n);
1795 pattern = o->data + o_get_last_ptr(o, n);
1796 debug_printf_glob("glob pattern '%s'\n", pattern);
1797 if (!glob_needed(pattern)) {
1799 o->length = unbackslash(pattern) - o->data;
1800 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
1801 return o_save_ptr_helper(o, n);
1804 memset(&globdata, 0, sizeof(globdata));
1805 gr = glob(pattern, 0, NULL, &globdata);
1806 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
1807 if (gr == GLOB_NOSPACE)
1808 bb_error_msg_and_die("out of memory during glob");
1809 if (gr == GLOB_NOMATCH) {
1810 globfree(&globdata);
1813 if (gr != 0) { /* GLOB_ABORTED ? */
1814 //TODO: testcase for bad glob pattern behavior
1815 bb_error_msg("glob(3) error %d on '%s'", gr, pattern);
1817 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
1818 char **argv = globdata.gl_pathv;
1819 o->length = pattern - o->data; /* "forget" pattern */
1821 o_addstr_with_NUL(o, *argv);
1822 n = o_save_ptr_helper(o, n);
1828 globfree(&globdata);
1830 debug_print_list("o_glob returning", o, n);
1834 /* If o->o_glob == 1, glob the string so far remembered.
1835 * Otherwise, just finish current list[] and start new */
1836 static int o_save_ptr(o_string *o, int n)
1838 if (o->o_glob) { /* if globbing is requested */
1839 /* If o->has_empty_slot, list[n] was already globbed
1840 * (if it was requested back then when it was filled)
1841 * so don't do that again! */
1842 if (!o->has_empty_slot)
1843 return o_glob(o, n); /* o_save_ptr_helper is inside */
1845 return o_save_ptr_helper(o, n);
1848 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
1849 static char **o_finalize_list(o_string *o, int n)
1854 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
1856 debug_print_list("finalized", o, n);
1857 debug_printf_expand("finalized n:%d\n", n);
1858 list = (char**)o->data;
1859 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
1863 list[n] = o->data + (int)(ptrdiff_t)list[n] + string_start;
1869 /* Expansion can recurse */
1870 #if ENABLE_HUSH_TICK
1871 static int process_command_subs(o_string *dest, const char *s);
1873 static char *expand_string_to_string(const char *str);
1875 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
1876 parse_stream_dquoted(dest, input, dquote_end)
1878 static int parse_stream_dquoted(o_string *as_string,
1880 struct in_str *input,
1883 /* expand_strvec_to_strvec() takes a list of strings, expands
1884 * all variable references within and returns a pointer to
1885 * a list of expanded strings, possibly with larger number
1886 * of strings. (Think VAR="a b"; echo $VAR).
1887 * This new list is allocated as a single malloc block.
1888 * NULL-terminated list of char* pointers is at the beginning of it,
1889 * followed by strings themself.
1890 * Caller can deallocate entire list by single free(list). */
1892 /* Store given string, finalizing the word and starting new one whenever
1893 * we encounter IFS char(s). This is used for expanding variable values.
1894 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
1895 static int expand_on_ifs(o_string *output, int n, const char *str)
1898 int word_len = strcspn(str, G.ifs);
1900 if (output->o_escape || !output->o_glob)
1901 o_addQstr(output, str, word_len);
1902 else /* protect backslashes against globbing up :) */
1903 o_addblock_duplicate_backslash(output, str, word_len);
1906 if (!*str) /* EOL - do not finalize word */
1908 o_addchr(output, '\0');
1909 debug_print_list("expand_on_ifs", output, n);
1910 n = o_save_ptr(output, n);
1911 str += strspn(str, G.ifs); /* skip ifs chars */
1913 debug_print_list("expand_on_ifs[1]", output, n);
1917 /* Helper to expand $((...)) and heredoc body. These act as if
1918 * they are in double quotes, with the exception that they are not :).
1919 * Just the rules are similar: "expand only $var and `cmd`"
1921 * Returns malloced string.
1922 * As an optimization, we return NULL if expansion is not needed.
1924 static char *expand_pseudo_dquoted(const char *str)
1927 struct in_str input;
1928 o_string dest = NULL_O_STRING;
1930 if (strchr(str, '$') == NULL
1931 #if ENABLE_HUSH_TICK
1932 && strchr(str, '`') == NULL
1938 /* We need to expand. Example:
1939 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
1941 setup_string_in_str(&input, str);
1942 parse_stream_dquoted(NULL, &dest, &input, EOF);
1943 //bb_error_msg("'%s' -> '%s'", str, dest.data);
1944 exp_str = expand_string_to_string(dest.data);
1945 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
1946 o_free_unsafe(&dest);
1950 /* Expand all variable references in given string, adding words to list[]
1951 * at n, n+1,... positions. Return updated n (so that list[n] is next one
1952 * to be filled). This routine is extremely tricky: has to deal with
1953 * variables/parameters with whitespace, $* and $@, and constructs like
1954 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
1955 static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask)
1957 /* or_mask is either 0 (normal case) or 0x80
1958 * (expansion of right-hand side of assignment == 1-element expand.
1959 * It will also do no globbing, and thus we must not backslash-quote!) */
1961 char first_ch, ored_ch;
1969 debug_printf_expand("expand_vars_to_list: arg '%s'\n", arg);
1970 debug_print_list("expand_vars_to_list", output, n);
1971 n = o_save_ptr(output, n);
1972 debug_print_list("expand_vars_to_list[0]", output, n);
1974 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
1975 #if ENABLE_HUSH_TICK
1976 o_string subst_result = NULL_O_STRING;
1978 #if ENABLE_SH_MATH_SUPPORT
1979 char arith_buf[sizeof(arith_t)*3 + 2];
1981 o_addblock(output, arg, p - arg);
1982 debug_print_list("expand_vars_to_list[1]", output, n);
1984 p = strchr(p, SPECIAL_VAR_SYMBOL);
1986 first_ch = arg[0] | or_mask; /* forced to "quoted" if or_mask = 0x80 */
1987 /* "$@" is special. Even if quoted, it can still
1988 * expand to nothing (not even an empty string) */
1989 if ((first_ch & 0x7f) != '@')
1990 ored_ch |= first_ch;
1993 switch (first_ch & 0x7f) {
1994 /* Highest bit in first_ch indicates that var is double-quoted */
1996 val = utoa(G.root_pid);
1998 case '!': /* bg pid */
1999 val = G.last_bg_pid ? utoa(G.last_bg_pid) : (char*)"";
2001 case '?': /* exitcode */
2002 val = utoa(G.last_exitcode);
2004 case '#': /* argc */
2005 if (arg[1] != SPECIAL_VAR_SYMBOL)
2006 /* actually, it's a ${#var} */
2008 val = utoa(G.global_argc ? G.global_argc-1 : 0);
2013 if (!G.global_argv[i])
2015 ored_ch |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
2016 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
2017 smallint sv = output->o_escape;
2018 /* unquoted var's contents should be globbed, so don't escape */
2019 output->o_escape = 0;
2020 while (G.global_argv[i]) {
2021 n = expand_on_ifs(output, n, G.global_argv[i]);
2022 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
2023 if (G.global_argv[i++][0] && G.global_argv[i]) {
2024 /* this argv[] is not empty and not last:
2025 * put terminating NUL, start new word */
2026 o_addchr(output, '\0');
2027 debug_print_list("expand_vars_to_list[2]", output, n);
2028 n = o_save_ptr(output, n);
2029 debug_print_list("expand_vars_to_list[3]", output, n);
2032 output->o_escape = sv;
2034 /* If or_mask is nonzero, we handle assignment 'a=....$@.....'
2035 * and in this case should treat it like '$*' - see 'else...' below */
2036 if (first_ch == ('@'|0x80) && !or_mask) { /* quoted $@ */
2038 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2039 if (++i >= G.global_argc)
2041 o_addchr(output, '\0');
2042 debug_print_list("expand_vars_to_list[4]", output, n);
2043 n = o_save_ptr(output, n);
2045 } else { /* quoted $*: add as one word */
2047 o_addQstr(output, G.global_argv[i], strlen(G.global_argv[i]));
2048 if (!G.global_argv[++i])
2051 o_addchr(output, G.ifs[0]);
2055 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
2056 /* "Empty variable", used to make "" etc to not disappear */
2060 #if ENABLE_HUSH_TICK
2061 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
2064 //TODO: can we just stuff it into "output" directly?
2065 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
2066 process_command_subs(&subst_result, arg);
2067 debug_printf_subst("SUBST RES '%s'\n", subst_result.data);
2068 val = subst_result.data;
2071 #if ENABLE_SH_MATH_SUPPORT
2072 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
2073 arith_eval_hooks_t hooks;
2078 arg++; /* skip '+' */
2079 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
2080 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
2082 exp_str = expand_pseudo_dquoted(arg);
2083 hooks.lookupvar = get_local_var_value;
2084 hooks.setvar = arith_set_local_var;
2085 hooks.endofname = endofname;
2086 res = arith(exp_str ? exp_str : arg, &errcode, &hooks);
2090 const char *msg = "error in arithmetic";
2093 msg = "exponent less than 0";
2096 msg = "divide by 0";
2099 msg = "expression recursion loop detected";
2104 debug_printf_subst("ARITH RES '"arith_t_fmt"'\n", res);
2105 sprintf(arith_buf, arith_t_fmt, res);
2110 default: /* <SPECIAL_VAR_SYMBOL>varname<SPECIAL_VAR_SYMBOL> */
2112 bool exp_len = false;
2113 bool exp_null = false;
2115 char exp_save = exp_save; /* for compiler */
2116 char exp_op = exp_op; /* for compiler */
2117 char *exp_word = exp_word; /* for compiler */
2121 arg[0] = first_ch & 0x7f;
2123 /* prepare for expansions */
2124 if (var[0] == '#') {
2125 /* handle length expansion ${#var} */
2129 /* maybe handle parameter expansion */
2130 exp_off = strcspn(var, ":-=+?%#");
2134 exp_save = var[exp_off];
2135 exp_null = exp_save == ':';
2136 exp_word = var + exp_off;
2139 exp_op = *exp_word++;
2140 var[exp_off] = '\0';
2144 /* lookup the variable in question */
2145 if (isdigit(var[0])) {
2146 /* handle_dollar() should have vetted var for us */
2148 if (i < G.global_argc)
2149 val = G.global_argv[i];
2150 /* else val remains NULL: $N with too big N */
2152 val = get_local_var_value(var);
2154 /* handle any expansions */
2156 debug_printf_expand("expand: length of '%s' = ", val);
2157 val = utoa(val ? strlen(val) : 0);
2158 debug_printf_expand("%s\n", val);
2159 } else if (exp_off) {
2160 if (exp_op == '%' || exp_op == '#') {
2162 /* we need to do a pattern match */
2165 scan_t scan = pick_scan(exp_op, *exp_word, &zero);
2166 if (exp_op == *exp_word) /* ## or %% */
2168 val = dyn_val = xstrdup(val);
2169 loc = scan(dyn_val, exp_word, zero);
2176 /* we need to do an expansion */
2177 int exp_test = (!val || (exp_null && !val[0]));
2179 exp_test = !exp_test;
2180 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
2181 exp_null ? "true" : "false", exp_test);
2183 if (exp_op == '?') {
2184 //TODO: how interactive bash aborts expansion mid-command?
2185 /* ${var?[error_msg_if_unset]} */
2186 /* ${var:?[error_msg_if_unset_or_null]} */
2187 /* mimic bash message */
2188 die_if_script("%s: %s",
2190 exp_word[0] ? exp_word : "parameter null or not set"
2196 if (exp_op == '=') {
2197 /* ${var=[word]} or ${var:=[word]} */
2198 if (isdigit(var[0]) || var[0] == '#') {
2199 /* mimic bash message */
2200 die_if_script("$%s: cannot assign in this way", var);
2203 char *new_var = xasprintf("%s=%s", var, val);
2204 set_local_var(new_var, -1, 0);
2210 var[exp_off] = exp_save;
2214 #if ENABLE_HUSH_TICK
2217 if (!(first_ch & 0x80)) { /* unquoted $VAR */
2218 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val, output->o_escape);
2220 /* unquoted var's contents should be globbed, so don't escape */
2221 smallint sv = output->o_escape;
2222 output->o_escape = 0;
2223 n = expand_on_ifs(output, n, val);
2225 output->o_escape = sv;
2227 } else { /* quoted $VAR, val will be appended below */
2228 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val, output->o_escape);
2231 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
2233 o_addQstr(output, val, strlen(val));
2237 /* Do the check to avoid writing to a const string */
2238 if (*p != SPECIAL_VAR_SYMBOL)
2239 *p = SPECIAL_VAR_SYMBOL;
2241 #if ENABLE_HUSH_TICK
2242 o_free(&subst_result);
2245 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
2248 debug_print_list("expand_vars_to_list[a]", output, n);
2249 /* this part is literal, and it was already pre-quoted
2250 * if needed (much earlier), do not use o_addQstr here! */
2251 o_addstr_with_NUL(output, arg);
2252 debug_print_list("expand_vars_to_list[b]", output, n);
2253 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
2254 && !(ored_ch & 0x80) /* and all vars were not quoted. */
2257 /* allow to reuse list[n] later without re-growth */
2258 output->has_empty_slot = 1;
2260 o_addchr(output, '\0');
2265 static char **expand_variables(char **argv, int or_mask)
2270 o_string output = NULL_O_STRING;
2272 if (or_mask & 0x100) {
2273 output.o_escape = 1; /* protect against globbing for "$var" */
2274 /* (unquoted $var will temporarily switch it off) */
2281 n = expand_vars_to_list(&output, n, *v, (char)or_mask);
2284 debug_print_list("expand_variables", &output, n);
2286 /* output.data (malloced in one block) gets returned in "list" */
2287 list = o_finalize_list(&output, n);
2288 debug_print_strings("expand_variables[1]", list);
2292 static char **expand_strvec_to_strvec(char **argv)
2294 return expand_variables(argv, 0x100);
2297 /* Used for expansion of right hand of assignments */
2298 /* NB: should NOT do globbing! "export v=/bin/c*; env | grep ^v=" outputs
2300 static char *expand_string_to_string(const char *str)
2302 char *argv[2], **list;
2304 argv[0] = (char*)str;
2306 list = expand_variables(argv, 0x80); /* 0x80: make one-element expansion */
2308 if (!list[0] || list[1])
2309 bb_error_msg_and_die("BUG in varexp2");
2310 /* actually, just move string 2*sizeof(char*) bytes back */
2311 overlapping_strcpy((char*)list, list[0]);
2312 debug_printf_expand("string_to_string='%s'\n", (char*)list);
2316 /* Used for "eval" builtin */
2317 static char* expand_strvec_to_string(char **argv)
2321 list = expand_variables(argv, 0x80);
2322 /* Convert all NULs to spaces */
2327 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
2328 bb_error_msg_and_die("BUG in varexp3");
2329 list[n][-1] = ' '; /* TODO: or to G.ifs[0]? */
2333 overlapping_strcpy((char*)list, list[0]);
2334 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
2338 static char **expand_assignments(char **argv, int count)
2342 /* Expand assignments into one string each */
2343 for (i = 0; i < count; i++) {
2344 p = add_string_to_strings(p, expand_string_to_string(argv[i]));
2352 void re_execute_shell(char ***to_free, const char *s, char *argv0, char **argv);
2354 static void reset_traps_to_defaults(void)
2356 /* This function is always called in a child shell
2357 * after fork (not vfork, NOMMU doesn't use this function).
2358 * Child shells are not interactive.
2359 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
2360 * Testcase: (while :; do :; done) + ^Z should background.
2361 * Same goes for SIGTERM, SIGHUP, SIGINT.
2366 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
2369 /* Stupid. It can be done with *single* &= op, but we can't use
2370 * the fact that G.blocked_set is implemented as a bitmask... */
2371 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
2375 sigdelset(&G.blocked_set, sig);
2382 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
2383 mask = G.non_DFL_mask;
2384 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
2388 G.traps[sig] = NULL;
2389 /* There is no signal for 0 (EXIT) */
2392 /* There was a trap handler, we are removing it.
2393 * But if sig still has non-DFL handling,
2394 * we should not unblock it. */
2397 sigdelset(&G.blocked_set, sig);
2399 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
2404 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv) NORETURN;
2405 static void re_execute_shell(char ***to_free, const char *s, char *g_argv0, char **g_argv)
2407 char param_buf[sizeof("-$%x:%x:%x:%x") + sizeof(unsigned) * 4];
2408 char *heredoc_argv[4];
2409 struct variable *cur;
2410 #if ENABLE_HUSH_FUNCTIONS
2411 struct function *funcp;
2416 if (!g_argv0) { /* heredoc */
2417 argv = heredoc_argv;
2418 argv[0] = (char *) G.argv0_for_re_execing;
2419 argv[1] = (char *) "-<";
2420 argv[2] = (char *) s;
2422 pp = &argv[3]; /* used as pointer to empty environment */
2426 sprintf(param_buf, "-$%x:%x:%x" USE_HUSH_LOOPS(":%x")
2427 , (unsigned) G.root_pid
2428 , (unsigned) G.last_bg_pid
2429 , (unsigned) G.last_exitcode
2430 USE_HUSH_LOOPS(, G.depth_of_loop)
2432 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<depth> <vars...> <funcs...>
2433 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
2436 for (cur = G.top_var; cur; cur = cur->next) {
2437 if (!cur->flg_export || cur->flg_read_only)
2440 #if ENABLE_HUSH_FUNCTIONS
2441 for (funcp = G.top_func; funcp; funcp = funcp->next)
2447 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
2448 *pp++ = (char *) G.argv0_for_re_execing;
2450 for (cur = G.top_var; cur; cur = cur->next) {
2451 if (cur->varstr == hush_version_str)
2453 if (cur->flg_read_only) {
2454 *pp++ = (char *) "-R";
2455 *pp++ = cur->varstr;
2456 } else if (!cur->flg_export) {
2457 *pp++ = (char *) "-V";
2458 *pp++ = cur->varstr;
2461 #if ENABLE_HUSH_FUNCTIONS
2462 for (funcp = G.top_func; funcp; funcp = funcp->next) {
2463 *pp++ = (char *) "-F";
2464 *pp++ = funcp->name;
2465 *pp++ = funcp->body_as_string;
2468 /* We can pass activated traps here. Say, -Tnn:trap_string
2470 * However, POSIX says that subshells reset signals with traps
2472 * I tested bash-3.2 and it not only does that with true subshells
2473 * of the form ( list ), but with any forked children shells.
2474 * I set trap "echo W" WINCH; and then tried:
2476 * { echo 1; sleep 20; echo 2; } &
2477 * while true; do echo 1; sleep 20; echo 2; break; done &
2478 * true | { echo 1; sleep 20; echo 2; } | cat
2480 * In all these cases sending SIGWINCH to the child shell
2481 * did not run the trap. If I add trap "echo V" WINCH;
2482 * _inside_ group (just before echo 1), it works.
2484 * I conclude it means we don't need to pass active traps here.
2485 * exec syscall below resets them to SIG_DFL for us.
2487 *pp++ = (char *) "-c";
2492 /* *pp = NULL; - is already there */
2496 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
2497 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2498 execve(bb_busybox_exec_path, argv, pp);
2499 /* Fallback. Useful for init=/bin/hush usage etc */
2500 if (argv[0][0] == '/')
2501 execve(argv[0], argv, pp);
2502 xfunc_error_retval = 127;
2503 bb_error_msg_and_die("can't re-execute the shell");
2505 #endif /* !BB_MMU */
2508 static void setup_heredoc(struct redir_struct *redir)
2510 struct fd_pair pair;
2513 /* the _body_ of heredoc (misleading field name) */
2514 const char *heredoc = redir->rd_filename;
2521 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
2522 expanded = expand_pseudo_dquoted(heredoc);
2526 len = strlen(heredoc);
2528 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
2530 xmove_fd(pair.rd, redir->rd_fd);
2532 /* Try writing without forking. Newer kernels have
2533 * dynamically growing pipes. Must use non-blocking write! */
2536 written = write(pair.wr, heredoc, len);
2547 ndelay_off(pair.wr);
2549 /* Okay, pipe buffer was not big enough */
2550 /* Note: we must not create a stray child (bastard? :)
2551 * for the unsuspecting parent process. Child creates a grandchild
2552 * and exits before parent execs the process which consumes heredoc
2553 * (that exec happens after we return from this function) */
2559 bb_perror_msg_and_die("vfork");
2562 disable_restore_tty_pgrp_on_exit();
2563 pid = BB_MMU ? fork() : vfork();
2565 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
2569 close(redir->rd_fd); /* read side of the pipe */
2571 full_write(pair.wr, heredoc, len); /* may loop or block */
2574 /* Delegate blocking writes to another process */
2575 xmove_fd(pair.wr, STDOUT_FILENO);
2576 re_execute_shell(&to_free, heredoc, NULL, NULL);
2580 enable_restore_tty_pgrp_on_exit();
2586 wait(NULL); /* wait till child has died */
2589 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
2590 * and stderr if they are redirected. */
2591 static int setup_redirects(struct command *prog, int squirrel[])
2594 struct redir_struct *redir;
2596 for (redir = prog->redirects; redir; redir = redir->next) {
2597 if (redir->rd_type == REDIRECT_HEREDOC2) {
2598 /* rd_fd<<HERE case */
2599 if (squirrel && redir->rd_fd < 3) {
2600 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2602 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
2604 debug_printf_parse("set heredoc '%s'\n",
2605 redir->rd_filename);
2606 setup_heredoc(redir);
2610 if (redir->rd_dup == REDIRFD_TO_FILE) {
2611 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
2613 if (redir->rd_filename == NULL) {
2614 /* Something went wrong in the parse.
2615 * Pretend it didn't happen */
2616 bb_error_msg("bug in redirect parse");
2619 mode = redir_table[redir->rd_type].mode;
2620 p = expand_string_to_string(redir->rd_filename);
2621 openfd = open_or_warn(p, mode);
2624 /* this could get lost if stderr has been redirected, but
2625 * bash and ash both lose it as well (though zsh doesn't!) */
2626 //what the above comment tries to say?
2630 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
2631 openfd = redir->rd_dup;
2634 if (openfd != redir->rd_fd) {
2635 if (squirrel && redir->rd_fd < 3) {
2636 squirrel[redir->rd_fd] = dup(redir->rd_fd);
2638 if (openfd == REDIRFD_CLOSE) {
2639 /* "n>-" means "close me" */
2640 close(redir->rd_fd);
2642 xdup2(openfd, redir->rd_fd);
2643 if (redir->rd_dup == REDIRFD_TO_FILE)
2651 static void restore_redirects(int squirrel[])
2654 for (i = 0; i < 3; i++) {
2657 /* We simply die on error */
2664 static void free_pipe_list(struct pipe *head);
2666 /* Return code is the exit status of the pipe */
2667 static void free_pipe(struct pipe *pi)
2670 struct command *command;
2671 struct redir_struct *r, *rnext;
2674 if (pi->stopped_cmds > 0) /* why? */
2676 debug_printf_clean("run pipe: (pid %d)\n", getpid());
2677 for (i = 0; i < pi->num_cmds; i++) {
2678 command = &pi->cmds[i];
2679 debug_printf_clean(" command %d:\n", i);
2680 if (command->argv) {
2681 for (a = 0, p = command->argv; *p; a++, p++) {
2682 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2684 free_strings(command->argv);
2685 command->argv = NULL;
2687 /* not "else if": on syntax error, we may have both! */
2688 if (command->group) {
2689 debug_printf_clean(" begin group (grp_type:%d)\n",
2691 free_pipe_list(command->group);
2692 debug_printf_clean(" end group\n");
2693 command->group = NULL;
2695 /* else is crucial here.
2696 * If group != NULL, child_func is meaningless */
2697 #if ENABLE_HUSH_FUNCTIONS
2698 else if (command->child_func) {
2699 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2700 command->child_func->parent_cmd = NULL;
2704 free(command->group_as_string);
2705 command->group_as_string = NULL;
2707 for (r = command->redirects; r; r = rnext) {
2708 debug_printf_clean(" redirect %d%s",
2709 r->rd_fd, redir_table[r->rd_type].descrip);
2710 /* guard against the case >$FOO, where foo is unset or blank */
2711 if (r->rd_filename) {
2712 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2713 free(r->rd_filename);
2714 r->rd_filename = NULL;
2716 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2720 command->redirects = NULL;
2722 free(pi->cmds); /* children are an array, they get freed all at once */
2730 static void free_pipe_list(struct pipe *head)
2732 struct pipe *pi, *next;
2734 for (pi = head; pi; pi = next) {
2736 debug_printf_clean(" pipe reserved word %d\n", pi->res_word);
2739 debug_printf_clean("pipe followup code %d\n", pi->followup);
2741 /*pi->next = NULL;*/
2747 static int run_list(struct pipe *pi);
2749 #define parse_stream(pstring, input, end_trigger) \
2750 parse_stream(input, end_trigger)
2752 static struct pipe *parse_stream(char **pstring,
2753 struct in_str *input,
2755 static void parse_and_run_string(const char *s);
2758 static const struct built_in_command* find_builtin(const char *name)
2760 const struct built_in_command *x;
2761 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
2762 if (strcmp(name, x->cmd) != 0)
2764 debug_printf_exec("found builtin '%s'\n", name);
2770 #if ENABLE_HUSH_FUNCTIONS
2771 static const struct function *find_function(const char *name)
2773 const struct function *funcp = G.top_func;
2775 if (strcmp(name, funcp->name) == 0) {
2778 funcp = funcp->next;
2780 debug_printf_exec("found function '%s'\n", name);
2784 /* Note: takes ownership on name ptr */
2785 static struct function *new_function(char *name)
2787 struct function *funcp;
2788 struct function **funcpp = &G.top_func;
2790 while ((funcp = *funcpp) != NULL) {
2791 struct command *cmd;
2793 if (strcmp(funcp->name, name) != 0) {
2794 funcpp = &funcp->next;
2798 cmd = funcp->parent_cmd;
2799 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
2801 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
2803 /* Note: if !funcp->body, do not free body_as_string!
2804 * This is a special case of "-F name body" function:
2805 * body_as_string was not malloced! */
2807 free_pipe_list(funcp->body);
2809 free(funcp->body_as_string);
2813 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
2814 cmd->argv[0] = funcp->name;
2815 cmd->group = funcp->body;
2817 cmd->group_as_string = funcp->body_as_string;
2822 debug_printf_exec("remembering new function '%s'\n", command->argv[0]);
2823 funcp = *funcpp = xzalloc(sizeof(*funcp));
2824 /*funcp->next = NULL;*/
2831 #define exec_function(nommu_save, funcp, argv) \
2832 exec_function(funcp, argv)
2834 static void exec_function(nommu_save_t *nommu_save,
2835 const struct function *funcp,
2836 char **argv) NORETURN;
2837 static void exec_function(nommu_save_t *nommu_save,
2838 const struct function *funcp,
2844 argv[0] = G.global_argv[0];
2845 G.global_argv = argv;
2849 /* On MMU, funcp->body is always non-NULL */
2850 n = run_list(funcp->body);
2854 re_execute_shell(&nommu_save->argv_from_re_execing,
2855 funcp->body_as_string,
2861 static int run_function(const struct function *funcp, char **argv)
2867 save_and_replace_G_args(&sv, argv);
2868 /* "we are in function, ok to use return" */
2869 sv_flg = G.flag_return_in_progress;
2870 G.flag_return_in_progress = -1;
2872 /* On MMU, funcp->body is always non-NULL */
2875 /* Function defined by -F */
2876 parse_and_run_string(funcp->body_as_string);
2877 rc = G.last_exitcode;
2881 rc = run_list(funcp->body);
2884 G.flag_return_in_progress = sv_flg;
2885 restore_G_args(&sv, argv);
2893 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
2894 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
2895 #define pseudo_exec(nommu_save, command, argv_expanded) \
2896 pseudo_exec(command, argv_expanded)
2899 /* Called after [v]fork() in run_pipe, or from builtin_exec.
2901 * Don't exit() here. If you don't exec, use _exit instead.
2902 * The at_exit handlers apparently confuse the calling process,
2903 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
2904 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2905 char **argv, int assignment_cnt,
2906 char **argv_expanded) NORETURN;
2907 static void pseudo_exec_argv(nommu_save_t *nommu_save,
2908 char **argv, int assignment_cnt,
2909 char **argv_expanded)
2913 /* Case when we are here: ... | var=val | ... */
2914 if (!argv[assignment_cnt])
2915 _exit(EXIT_SUCCESS);
2917 new_env = expand_assignments(argv, assignment_cnt);
2919 putenv_all(new_env);
2920 free(new_env); /* optional */
2922 nommu_save->new_env = new_env;
2923 nommu_save->old_env = putenv_all_and_save_old(new_env);
2925 if (argv_expanded) {
2926 argv = argv_expanded;
2928 argv = expand_strvec_to_strvec(argv + assignment_cnt);
2930 nommu_save->argv = argv;
2934 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2935 if (strchr(argv[0], '/') != NULL)
2939 /* On NOMMU, we must never block!
2940 * Example: { sleep 99999 | read line } & echo Ok
2941 * read builtin will block on read syscall, leaving parent blocked
2942 * in vfork. Therefore we can't do this:
2945 /* Check if the command matches any of the builtins.
2946 * Depending on context, this might be redundant. But it's
2947 * easier to waste a few CPU cycles than it is to figure out
2948 * if this is one of those cases.
2952 const struct built_in_command *x = find_builtin(argv[0]);
2954 rcode = x->function(argv);
2960 #if ENABLE_HUSH_FUNCTIONS
2961 /* Check if the command matches any functions */
2963 const struct function *funcp = find_function(argv[0]);
2965 exec_function(nommu_save, funcp, argv);
2970 #if ENABLE_FEATURE_SH_STANDALONE
2971 /* Check if the command matches any busybox applets */
2973 int a = find_applet_by_name(argv[0]);
2975 # if BB_MMU /* see above why on NOMMU it is not allowed */
2976 if (APPLET_IS_NOEXEC(a)) {
2977 debug_printf_exec("running applet '%s'\n", argv[0]);
2978 run_applet_no_and_exit(a, argv);
2981 /* Re-exec ourselves */
2982 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
2983 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2984 execv(bb_busybox_exec_path, argv);
2985 /* If they called chroot or otherwise made the binary no longer
2986 * executable, fall through */
2991 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
2994 debug_printf_exec("execing '%s'\n", argv[0]);
2995 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
2996 execvp(argv[0], argv);
2997 bb_perror_msg("can't exec '%s'", argv[0]);
2998 _exit(EXIT_FAILURE);
3001 /* Called after [v]fork() in run_pipe
3003 static void pseudo_exec(nommu_save_t *nommu_save,
3004 struct command *command,
3005 char **argv_expanded) NORETURN;
3006 static void pseudo_exec(nommu_save_t *nommu_save,
3007 struct command *command,
3008 char **argv_expanded)
3010 if (command->argv) {
3011 pseudo_exec_argv(nommu_save, command->argv,
3012 command->assignment_cnt, argv_expanded);
3015 if (command->group) {
3016 /* Cases when we are here:
3019 * ... | ( list ) | ...
3020 * ... | { list } | ...
3024 debug_printf_exec("pseudo_exec: run_list\n");
3025 reset_traps_to_defaults();
3026 rcode = run_list(command->group);
3027 /* OK to leak memory by not calling free_pipe_list,
3028 * since this process is about to exit */
3031 re_execute_shell(&nommu_save->argv_from_re_execing,
3032 command->group_as_string,
3038 /* Case when we are here: ... | >file */
3039 debug_printf_exec("pseudo_exec'ed null command\n");
3040 _exit(EXIT_SUCCESS);
3044 static const char *get_cmdtext(struct pipe *pi)
3050 /* This is subtle. ->cmdtext is created only on first backgrounding.
3051 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
3052 * On subsequent bg argv is trashed, but we won't use it */
3055 argv = pi->cmds[0].argv;
3056 if (!argv || !argv[0]) {
3057 pi->cmdtext = xzalloc(1);
3062 do len += strlen(*argv) + 1; while (*++argv);
3063 pi->cmdtext = p = xmalloc(len);
3064 argv = pi->cmds[0].argv;
3066 len = strlen(*argv);
3067 memcpy(p, *argv, len);
3075 static void insert_bg_job(struct pipe *pi)
3077 struct pipe *thejob;
3080 /* Linear search for the ID of the job to use */
3082 for (thejob = G.job_list; thejob; thejob = thejob->next)
3083 if (thejob->jobid >= pi->jobid)
3084 pi->jobid = thejob->jobid + 1;
3086 /* Add thejob to the list of running jobs */
3088 thejob = G.job_list = xmalloc(sizeof(*thejob));
3090 for (thejob = G.job_list; thejob->next; thejob = thejob->next)
3092 thejob->next = xmalloc(sizeof(*thejob));
3093 thejob = thejob->next;
3096 /* Physically copy the struct job */
3097 memcpy(thejob, pi, sizeof(struct pipe));
3098 thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
3099 /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */
3100 for (i = 0; i < pi->num_cmds; i++) {
3101 // TODO: do we really need to have so many fields which are just dead weight
3102 // at execution stage?
3103 thejob->cmds[i].pid = pi->cmds[i].pid;
3104 /* all other fields are not used and stay zero */
3106 thejob->next = NULL;
3107 thejob->cmdtext = xstrdup(get_cmdtext(pi));
3109 /* We don't wait for background thejobs to return -- append it
3110 to the list of backgrounded thejobs and leave it alone */
3111 if (G_interactive_fd)
3112 printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext);
3113 G.last_bg_pid = thejob->cmds[0].pid;
3114 G.last_jobid = thejob->jobid;
3117 static void remove_bg_job(struct pipe *pi)
3119 struct pipe *prev_pipe;
3121 if (pi == G.job_list) {
3122 G.job_list = pi->next;
3124 prev_pipe = G.job_list;
3125 while (prev_pipe->next != pi)
3126 prev_pipe = prev_pipe->next;
3127 prev_pipe->next = pi->next;
3130 G.last_jobid = G.job_list->jobid;
3135 /* Remove a backgrounded job */
3136 static void delete_finished_bg_job(struct pipe *pi)
3139 pi->stopped_cmds = 0;
3145 /* Check to see if any processes have exited -- if they
3146 * have, figure out why and see if a job has completed */
3147 static int checkjobs(struct pipe* fg_pipe)
3157 debug_printf_jobs("checkjobs %p\n", fg_pipe);
3160 // if (G.handled_SIGCHLD == G.count_SIGCHLD)
3161 // /* avoid doing syscall, nothing there anyway */
3164 attributes = WUNTRACED;
3165 if (fg_pipe == NULL)
3166 attributes |= WNOHANG;
3168 /* Do we do this right?
3169 * bash-3.00# sleep 20 | false
3171 * [3]+ Stopped sleep 20 | false
3172 * bash-3.00# echo $?
3173 * 1 <========== bg pipe is not fully done, but exitcode is already known!
3174 * [hush 1.14.0: yes we do it right]
3181 // i = G.count_SIGCHLD;
3182 childpid = waitpid(-1, &status, attributes);
3183 if (childpid <= 0) {
3184 if (childpid && errno != ECHILD)
3185 bb_perror_msg("waitpid");
3186 // else /* Until next SIGCHLD, waitpid's are useless */
3187 // G.handled_SIGCHLD = i;
3190 dead = WIFEXITED(status) || WIFSIGNALED(status);
3193 if (WIFSTOPPED(status))
3194 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
3195 childpid, WSTOPSIG(status), WEXITSTATUS(status));
3196 if (WIFSIGNALED(status))
3197 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
3198 childpid, WTERMSIG(status), WEXITSTATUS(status));
3199 if (WIFEXITED(status))
3200 debug_printf_jobs("pid %d exited, exitcode %d\n",
3201 childpid, WEXITSTATUS(status));
3203 /* Were we asked to wait for fg pipe? */
3205 for (i = 0; i < fg_pipe->num_cmds; i++) {
3206 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
3207 if (fg_pipe->cmds[i].pid != childpid)
3210 fg_pipe->cmds[i].pid = 0;
3211 fg_pipe->alive_cmds--;
3212 if (i == fg_pipe->num_cmds - 1) {
3213 /* last process gives overall exitstatus */
3214 rcode = WEXITSTATUS(status);
3215 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
3218 fg_pipe->cmds[i].is_stopped = 1;
3219 fg_pipe->stopped_cmds++;
3221 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
3222 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
3223 if (fg_pipe->alive_cmds - fg_pipe->stopped_cmds <= 0) {
3224 /* All processes in fg pipe have exited or stopped */
3225 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
3226 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
3227 * and "killall -STOP cat" */
3228 if (G_interactive_fd) {
3230 if (fg_pipe->alive_cmds)
3231 insert_bg_job(fg_pipe);
3236 /* There are still running processes in the fg pipe */
3237 goto wait_more; /* do waitpid again */
3239 /* it wasnt fg_pipe, look for process in bg pipes */
3243 /* We asked to wait for bg or orphaned children */
3244 /* No need to remember exitcode in this case */
3245 for (pi = G.job_list; pi; pi = pi->next) {
3246 for (i = 0; i < pi->num_cmds; i++) {
3247 if (pi->cmds[i].pid == childpid)
3248 goto found_pi_and_prognum;
3251 /* Happens when shell is used as init process (init=/bin/sh) */
3252 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
3253 continue; /* do waitpid again */
3255 found_pi_and_prognum:
3258 pi->cmds[i].pid = 0;
3260 if (!pi->alive_cmds) {
3261 if (G_interactive_fd)
3262 printf(JOB_STATUS_FORMAT, pi->jobid,
3263 "Done", pi->cmdtext);
3264 delete_finished_bg_job(pi);
3268 pi->cmds[i].is_stopped = 1;
3272 } /* while (waitpid succeeds)... */
3278 static int checkjobs_and_fg_shell(struct pipe* fg_pipe)
3281 int rcode = checkjobs(fg_pipe);
3282 /* Job finished, move the shell to the foreground */
3283 p = getpgid(0); /* pgid of our process */
3284 debug_printf_jobs("fg'ing ourself: getpgid(0)=%d\n", (int)p);
3285 tcsetpgrp(G_interactive_fd, p);
3290 /* Start all the jobs, but don't wait for anything to finish.
3293 * Return code is normally -1, when the caller has to wait for children
3294 * to finish to determine the exit status of the pipe. If the pipe
3295 * is a simple builtin command, however, the action is done by the
3296 * time run_pipe returns, and the exit code is provided as the
3299 * Returns -1 only if started some children. IOW: we have to
3300 * mask out retvals of builtins etc with 0xff!
3302 * The only case when we do not need to [v]fork is when the pipe
3303 * is single, non-backgrounded, non-subshell command. Examples:
3304 * cmd ; ... { list } ; ...
3305 * cmd && ... { list } && ...
3306 * cmd || ... { list } || ...
3307 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
3308 * or (if SH_STANDALONE) an applet, and we can run the { list }
3309 * with run_list(). If it isn't one of these, we fork and exec cmd.
3311 * Cases when we must fork:
3312 * non-single: cmd | cmd
3313 * backgrounded: cmd & { list } &
3314 * subshell: ( list ) [&]
3316 static int run_pipe(struct pipe *pi)
3318 static const char *const null_ptr = NULL;
3321 int pipefds[2]; /* pipefds[0] is for reading */
3322 struct command *command;
3323 char **argv_expanded;
3326 /* it is not always needed, but we aim to smaller code */
3327 int squirrel[] = { -1, -1, -1 };
3330 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
3333 USE_HUSH_JOB(pi->pgrp = -1;)
3334 pi->stopped_cmds = 0;
3335 command = &(pi->cmds[0]);
3336 argv_expanded = NULL;
3338 if (pi->num_cmds != 1
3339 || pi->followup == PIPE_BG
3340 || command->grp_type == GRP_SUBSHELL
3347 debug_printf_exec(": group:%p argv:'%s'\n",
3348 command->group, command->argv ? command->argv[0] : "NONE");
3350 if (command->group) {
3351 #if ENABLE_HUSH_FUNCTIONS
3352 if (command->grp_type == GRP_FUNCTION) {
3353 /* "executing" func () { list } */
3354 struct function *funcp;
3356 funcp = new_function(command->argv[0]);
3357 /* funcp->name is already set to argv[0] */
3358 funcp->body = command->group;
3360 funcp->body_as_string = command->group_as_string;
3361 command->group_as_string = NULL;
3363 command->group = NULL;
3364 command->argv[0] = NULL;
3365 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
3366 funcp->parent_cmd = command;
3367 command->child_func = funcp;
3369 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
3371 return EXIT_SUCCESS;
3375 debug_printf("non-subshell group\n");
3376 rcode = 1; /* exitcode if redir failed */
3377 if (setup_redirects(command, squirrel) == 0) {
3378 debug_printf_exec(": run_list\n");
3379 rcode = run_list(command->group) & 0xff;
3381 restore_redirects(squirrel);
3382 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3384 debug_printf_exec("run_pipe: return %d\n", rcode);
3388 argv = command->argv ? command->argv : (char **) &null_ptr;
3390 const struct built_in_command *x;
3391 #if ENABLE_HUSH_FUNCTIONS
3392 const struct function *funcp;
3396 char **new_env = NULL;
3397 char **old_env = NULL;
3399 if (argv[command->assignment_cnt] == NULL) {
3400 /* Assignments, but no command */
3401 /* Ensure redirects take effect. Try "a=t >file" */
3402 rcode = setup_redirects(command, squirrel);
3403 restore_redirects(squirrel);
3404 /* Set shell variables */
3406 p = expand_string_to_string(*argv);
3407 debug_printf_exec("set shell var:'%s'->'%s'\n",
3409 set_local_var(p, 0, 0);
3412 /* Do we need to flag set_local_var() errors?
3413 * "assignment to readonly var" and "putenv error"
3415 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3417 debug_printf_exec("run_pipe: return %d\n", rcode);
3421 /* Expand the rest into (possibly) many strings each */
3422 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
3424 x = find_builtin(argv_expanded[0]);
3425 #if ENABLE_HUSH_FUNCTIONS
3428 funcp = find_function(argv_expanded[0]);
3432 if (x->function == builtin_exec && argv_expanded[1] == NULL) {
3433 debug_printf("exec with redirects only\n");
3434 rcode = setup_redirects(command, NULL);
3435 goto clean_up_and_ret1;
3438 /* setup_redirects acts on file descriptors, not FILEs.
3439 * This is perfect for work that comes after exec().
3440 * Is it really safe for inline use? Experimentally,
3441 * things seem to work. */
3442 rcode = setup_redirects(command, squirrel);
3444 new_env = expand_assignments(argv, command->assignment_cnt);
3445 old_env = putenv_all_and_save_old(new_env);
3447 debug_printf_exec(": builtin '%s' '%s'...\n",
3448 x->cmd, argv_expanded[1]);
3449 rcode = x->function(argv_expanded) & 0xff;
3451 #if ENABLE_HUSH_FUNCTIONS
3453 debug_printf_exec(": function '%s' '%s'...\n",
3454 funcp->name, argv_expanded[1]);
3455 rcode = run_function(funcp, argv_expanded) & 0xff;
3459 #if ENABLE_FEATURE_SH_STANDALONE
3462 restore_redirects(squirrel);
3463 free_strings_and_unsetenv(new_env, 1);
3464 putenv_all(old_env);
3465 /* Free the pointers, but the strings themselves
3466 * are in environ now, don't use free_strings! */
3469 free(argv_expanded);
3470 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
3472 debug_printf_exec("run_pipe return %d\n", rcode);
3476 #if ENABLE_FEATURE_SH_STANDALONE
3477 i = find_applet_by_name(argv_expanded[0]);
3478 if (i >= 0 && APPLET_IS_NOFORK(i)) {
3479 rcode = setup_redirects(command, squirrel);
3481 new_env = expand_assignments(argv, command->assignment_cnt);
3482 old_env = putenv_all_and_save_old(new_env);
3483 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
3484 argv_expanded[0], argv_expanded[1]);
3485 rcode = run_nofork_applet(i, argv_expanded);
3487 goto clean_up_and_ret;
3490 /* It is neither builtin nor applet. We must fork. */
3494 /* NB: argv_expanded may already be created, and that
3495 * might include `cmd` runs! Do not rerun it! We *must*
3496 * use argv_expanded if it's non-NULL */
3498 /* Going to fork a child per each pipe member */
3502 for (i = 0; i < pi->num_cmds; i++) {
3504 volatile nommu_save_t nommu_save;
3505 nommu_save.new_env = NULL;
3506 nommu_save.old_env = NULL;
3507 nommu_save.argv = NULL;
3508 nommu_save.argv_from_re_execing = NULL;
3510 command = &(pi->cmds[i]);
3511 if (command->argv) {
3512 debug_printf_exec(": pipe member '%s' '%s'...\n",
3513 command->argv[0], command->argv[1]);
3515 debug_printf_exec(": pipe member with no argv\n");
3518 /* pipes are inserted between pairs of commands */
3521 if ((i + 1) < pi->num_cmds)
3524 command->pid = BB_MMU ? fork() : vfork();
3525 if (!command->pid) { /* child */
3527 disable_restore_tty_pgrp_on_exit();
3529 /* Every child adds itself to new process group
3530 * with pgid == pid_of_first_child_in_pipe */
3531 if (G.run_list_level == 1 && G_interactive_fd) {
3534 if (pgrp < 0) /* true for 1st process only */
3536 if (setpgid(0, pgrp) == 0 && pi->followup != PIPE_BG) {
3537 /* We do it in *every* child, not just first,
3539 tcsetpgrp(G_interactive_fd, pgrp);
3543 xmove_fd(nextin, 0);
3544 xmove_fd(pipefds[1], 1); /* write end */
3546 close(pipefds[0]); /* read end */
3547 /* Like bash, explicit redirects override pipes,
3548 * and the pipe fd is available for dup'ing. */
3549 if (setup_redirects(command, NULL))
3552 /* Restore default handlers just prior to exec */
3553 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
3555 /* Stores to nommu_save list of env vars putenv'ed
3556 * (NOMMU, on MMU we don't need that) */
3557 /* cast away volatility... */
3558 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
3559 /* pseudo_exec() does not return */
3562 /* parent or error */
3563 enable_restore_tty_pgrp_on_exit();
3565 /* Clean up after vforked child */
3566 free(nommu_save.argv);
3567 free(nommu_save.argv_from_re_execing);
3568 free_strings_and_unsetenv(nommu_save.new_env, 1);
3569 putenv_all(nommu_save.old_env);
3570 /* Free the pointers, but the strings themselves
3571 * are in environ now, don't use free_strings! */
3572 free(nommu_save.old_env);
3574 free(argv_expanded);
3575 argv_expanded = NULL;
3576 if (command->pid < 0) { /* [v]fork failed */
3577 /* Clearly indicate, was it fork or vfork */
3578 bb_perror_msg(BB_MMU ? "fork" : "vfork");
3582 /* Second and next children need to know pid of first one */
3584 pi->pgrp = command->pid;
3590 if ((i + 1) < pi->num_cmds)
3591 close(pipefds[1]); /* write end */
3592 /* Pass read (output) pipe end to next iteration */
3593 nextin = pipefds[0];
3596 if (!pi->alive_cmds) {
3598 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
3603 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
3607 #ifndef debug_print_tree
3608 static void debug_print_tree(struct pipe *pi, int lvl)
3610 static const char *const PIPE[] = {
3616 static const char *RES[] = {
3617 [RES_NONE ] = "NONE" ,
3620 [RES_THEN ] = "THEN" ,
3621 [RES_ELIF ] = "ELIF" ,
3622 [RES_ELSE ] = "ELSE" ,
3625 #if ENABLE_HUSH_LOOPS
3626 [RES_FOR ] = "FOR" ,
3627 [RES_WHILE] = "WHILE",
3628 [RES_UNTIL] = "UNTIL",
3630 [RES_DONE ] = "DONE" ,
3632 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3635 #if ENABLE_HUSH_CASE
3636 [RES_CASE ] = "CASE" ,
3637 [RES_MATCH] = "MATCH",
3638 [RES_CASEI] = "CASEI",
3639 [RES_ESAC ] = "ESAC" ,
3641 [RES_XXXX ] = "XXXX" ,
3642 [RES_SNTX ] = "SNTX" ,
3644 static const char *const GRPTYPE[] = {
3647 #if ENABLE_HUSH_FUNCTIONS
3656 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3657 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3659 while (prn < pi->num_cmds) {
3660 struct command *command = &pi->cmds[prn];
3661 char **argv = command->argv;
3663 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
3665 command->assignment_cnt);
3666 if (command->group) {
3667 fprintf(stderr, " group %s: (argv=%p)\n",
3668 GRPTYPE[command->grp_type],
3670 debug_print_tree(command->group, lvl+1);
3674 if (argv) while (*argv) {
3675 fprintf(stderr, " '%s'", *argv);
3678 fprintf(stderr, "\n");
3687 /* NB: called by pseudo_exec, and therefore must not modify any
3688 * global data until exec/_exit (we can be a child after vfork!) */
3689 static int run_list(struct pipe *pi)
3691 #if ENABLE_HUSH_CASE
3692 char *case_word = NULL;
3694 #if ENABLE_HUSH_LOOPS
3695 struct pipe *loop_top = NULL;
3696 char *for_varname = NULL;
3697 char **for_lcur = NULL;
3698 char **for_list = NULL;
3700 smallint last_followup;
3702 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
3703 smalluint cond_code = 0;
3705 enum { cond_code = 0 };
3708 smallint rword; /* enum reserved_style */
3709 smallint last_rword; /* ditto */
3712 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
3715 #if ENABLE_HUSH_LOOPS
3716 /* Check syntax for "for" */
3717 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
3718 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
3720 /* current word is FOR or IN (BOLD in comments below) */
3721 if (cpipe->next == NULL) {
3722 syntax_error("malformed for");
3724 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3727 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
3728 if (cpipe->next->res_word == RES_DO)
3730 /* next word is not "do". It must be "in" then ("FOR v in ...") */
3731 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
3732 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
3734 syntax_error("malformed for");
3736 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
3742 /* Past this point, all code paths should jump to ret: label
3743 * in order to return, no direct "return" statements please.
3744 * This helps to ensure that no memory is leaked. */
3752 last_rword = RES_XXXX;
3754 last_followup = PIPE_SEQ;
3755 rcode = G.last_exitcode;
3757 /* Go through list of pipes, (maybe) executing them. */
3758 for (; pi; pi = USE_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
3762 IF_HAS_KEYWORDS(rword = pi->res_word;)
3763 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
3764 rword, cond_code, last_rword);
3765 #if ENABLE_HUSH_LOOPS
3766 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
3767 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
3769 /* start of a loop: remember where loop starts */
3774 /* Still in the same "if...", "then..." or "do..." branch? */
3775 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
3776 if ((rcode == 0 && last_followup == PIPE_OR)
3777 || (rcode != 0 && last_followup == PIPE_AND)
3779 /* It is "<true> || CMD" or "<false> && CMD"
3780 * and we should not execute CMD */
3781 debug_printf_exec("skipped cmd because of || or &&\n");
3782 last_followup = pi->followup;
3786 last_followup = pi->followup;
3787 IF_HAS_KEYWORDS(last_rword = rword;)
3790 if (rword == RES_THEN) {
3791 /* if false; then ... fi has exitcode 0! */
3792 G.last_exitcode = rcode = EXIT_SUCCESS;
3793 /* "if <false> THEN cmd": skip cmd */
3797 if (rword == RES_ELSE || rword == RES_ELIF) {
3798 /* "if <true> then ... ELSE/ELIF cmd":
3799 * skip cmd and all following ones */
3804 #if ENABLE_HUSH_LOOPS
3805 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
3807 /* first loop through for */
3809 static const char encoded_dollar_at[] ALIGN1 = {
3810 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
3811 }; /* encoded representation of "$@" */
3812 static const char *const encoded_dollar_at_argv[] = {
3813 encoded_dollar_at, NULL
3814 }; /* argv list with one element: "$@" */
3817 vals = (char**)encoded_dollar_at_argv;
3818 if (pi->next->res_word == RES_IN) {
3819 /* if no variable values after "in" we skip "for" */
3820 if (!pi->next->cmds[0].argv) {
3821 G.last_exitcode = rcode = EXIT_SUCCESS;
3822 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
3825 vals = pi->next->cmds[0].argv;
3826 } /* else: "for var; do..." -> assume "$@" list */
3827 /* create list of variable values */
3828 debug_print_strings("for_list made from", vals);
3829 for_list = expand_strvec_to_strvec(vals);
3830 for_lcur = for_list;
3831 debug_print_strings("for_list", for_list);
3832 for_varname = pi->cmds[0].argv[0];
3833 pi->cmds[0].argv[0] = NULL;
3835 free(pi->cmds[0].argv[0]);
3837 /* "for" loop is over, clean up */
3841 pi->cmds[0].argv[0] = for_varname;
3844 /* Insert next value from for_lcur */
3845 /* note: *for_lcur already has quotes removed, $var expanded, etc */
3846 pi->cmds[0].argv[0] = xasprintf("%s=%s", for_varname, *for_lcur++);
3847 pi->cmds[0].assignment_cnt = 1;
3849 if (rword == RES_IN) {
3850 continue; /* "for v IN list;..." - "in" has no cmds anyway */
3852 if (rword == RES_DONE) {
3853 continue; /* "done" has no cmds too */
3856 #if ENABLE_HUSH_CASE
3857 if (rword == RES_CASE) {
3858 case_word = expand_strvec_to_string(pi->cmds->argv);
3861 if (rword == RES_MATCH) {
3864 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
3866 /* all prev words didn't match, does this one match? */
3867 argv = pi->cmds->argv;
3869 char *pattern = expand_string_to_string(*argv);
3870 /* TODO: which FNM_xxx flags to use? */
3871 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
3873 if (cond_code == 0) { /* match! we will execute this branch */
3874 free(case_word); /* make future "word)" stop */
3882 if (rword == RES_CASEI) { /* inside of a case branch */
3884 continue; /* not matched yet, skip this pipe */
3887 /* Just pressing <enter> in shell should check for jobs.
3888 * OTOH, in non-interactive shell this is useless
3889 * and only leads to extra job checks */
3890 if (pi->num_cmds == 0) {
3891 if (G_interactive_fd)
3892 goto check_jobs_and_continue;
3896 /* After analyzing all keywords and conditions, we decided
3897 * to execute this pipe. NB: have to do checkjobs(NULL)
3898 * after run_pipe to collect any background children,
3899 * even if list execution is to be stopped. */
3900 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
3903 #if ENABLE_HUSH_LOOPS
3904 G.flag_break_continue = 0;
3906 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
3908 /* We ran a builtin, function, or group.
3909 * rcode is already known
3910 * and we don't need to wait for anything. */
3911 G.last_exitcode = rcode;
3912 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
3913 check_and_run_traps(0);
3914 #if ENABLE_HUSH_LOOPS
3915 /* Was it "break" or "continue"? */
3916 if (G.flag_break_continue) {
3917 smallint fbc = G.flag_break_continue;
3918 /* We might fall into outer *loop*,
3919 * don't want to break it too */
3921 G.depth_break_continue--;
3922 if (G.depth_break_continue == 0)
3923 G.flag_break_continue = 0;
3924 /* else: e.g. "continue 2" should *break* once, *then* continue */
3925 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
3926 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
3927 goto check_jobs_and_break;
3928 /* "continue": simulate end of loop */
3933 #if ENABLE_HUSH_FUNCTIONS
3934 if (G.flag_return_in_progress == 1)
3935 goto check_jobs_and_break;
3937 } else if (pi->followup == PIPE_BG) {
3938 /* What does bash do with attempts to background builtins? */
3939 /* even bash 3.2 doesn't do that well with nested bg:
3940 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
3941 * I'm NOT treating inner &'s as jobs */
3942 check_and_run_traps(0);
3944 if (G.run_list_level == 1)
3947 G.last_exitcode = rcode = EXIT_SUCCESS;
3948 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
3951 if (G.run_list_level == 1 && G_interactive_fd) {
3952 /* Waits for completion, then fg's main shell */
3953 rcode = checkjobs_and_fg_shell(pi);
3954 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
3955 check_and_run_traps(0);
3958 { /* This one just waits for completion */
3959 rcode = checkjobs(pi);
3960 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
3961 check_and_run_traps(0);
3963 G.last_exitcode = rcode;
3967 /* Analyze how result affects subsequent commands */
3969 if (rword == RES_IF || rword == RES_ELIF)
3972 #if ENABLE_HUSH_LOOPS
3973 /* Beware of "while false; true; do ..."! */
3974 if (pi->next && pi->next->res_word == RES_DO) {
3975 if (rword == RES_WHILE) {
3977 /* "while false; do...done" - exitcode 0 */
3978 G.last_exitcode = rcode = EXIT_SUCCESS;
3979 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
3980 goto check_jobs_and_break;
3983 if (rword == RES_UNTIL) {
3985 debug_printf_exec(": until expr is true: breaking\n");
3986 check_jobs_and_break:
3994 check_jobs_and_continue:
4001 #if ENABLE_HUSH_LOOPS
4006 #if ENABLE_HUSH_CASE
4010 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
4014 /* Select which version we will use */
4015 static int run_and_free_list(struct pipe *pi)
4018 debug_printf_exec("run_and_free_list entered\n");
4020 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
4021 rcode = run_list(pi);
4023 /* free_pipe_list has the side effect of clearing memory.
4024 * In the long run that function can be merged with run_list,
4025 * but doing that now would hobble the debugging effort. */
4027 debug_printf_exec("run_and_free_list return %d\n", rcode);
4032 static struct pipe *new_pipe(void)
4035 pi = xzalloc(sizeof(struct pipe));
4036 /*pi->followup = 0; - deliberately invalid value */
4037 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
4041 /* Command (member of a pipe) is complete, or we start a new pipe
4042 * if ctx->command is NULL.
4043 * No errors possible here.
4045 static int done_command(struct parse_context *ctx)
4047 /* The command is really already in the pipe structure, so
4048 * advance the pipe counter and make a new, null command. */
4049 struct pipe *pi = ctx->pipe;
4050 struct command *command = ctx->command;
4053 if (IS_NULL_CMD(command)) {
4054 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
4058 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
4059 //debug_print_tree(ctx->list_head, 20);
4061 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
4064 /* Only real trickiness here is that the uncommitted
4065 * command structure is not counted in pi->num_cmds. */
4066 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
4067 ctx->command = command = &pi->cmds[pi->num_cmds];
4069 memset(command, 0, sizeof(*command));
4070 return pi->num_cmds; /* used only for 0/nonzero check */
4073 static void done_pipe(struct parse_context *ctx, pipe_style type)
4077 debug_printf_parse("done_pipe entered, followup %d\n", type);
4078 /* Close previous command */
4079 not_null = done_command(ctx);
4080 ctx->pipe->followup = type;
4082 ctx->pipe->pi_inverted = ctx->ctx_inverted;
4083 ctx->ctx_inverted = 0;
4084 ctx->pipe->res_word = ctx->ctx_res_w;
4087 /* Without this check, even just <enter> on command line generates
4088 * tree of three NOPs (!). Which is harmless but annoying.
4089 * IOW: it is safe to do it unconditionally. */
4092 || ctx->ctx_res_w == RES_FI
4094 #if ENABLE_HUSH_LOOPS
4095 || ctx->ctx_res_w == RES_DONE
4096 || ctx->ctx_res_w == RES_FOR
4097 || ctx->ctx_res_w == RES_IN
4099 #if ENABLE_HUSH_CASE
4100 || ctx->ctx_res_w == RES_ESAC
4104 debug_printf_parse("done_pipe: adding new pipe: "
4105 "not_null:%d ctx->ctx_res_w:%d\n",
4106 not_null, ctx->ctx_res_w);
4108 ctx->pipe->next = new_p;
4110 /* RES_THEN, RES_DO etc are "sticky" -
4111 * they remain set for pipes inside if/while.
4112 * This is used to control execution.
4113 * RES_FOR and RES_IN are NOT sticky (needed to support
4114 * cases where variable or value happens to match a keyword):
4116 #if ENABLE_HUSH_LOOPS
4117 if (ctx->ctx_res_w == RES_FOR
4118 || ctx->ctx_res_w == RES_IN)
4119 ctx->ctx_res_w = RES_NONE;
4121 #if ENABLE_HUSH_CASE
4122 if (ctx->ctx_res_w == RES_MATCH)
4123 ctx->ctx_res_w = RES_CASEI;
4125 ctx->command = NULL; /* trick done_command below */
4126 /* Create the memory for command, roughly:
4127 * ctx->pipe->cmds = new struct command;
4128 * ctx->command = &ctx->pipe->cmds[0];
4131 //debug_print_tree(ctx->list_head, 10);
4133 debug_printf_parse("done_pipe return\n");
4136 static void initialize_context(struct parse_context *ctx)
4138 memset(ctx, 0, sizeof(*ctx));
4139 ctx->pipe = ctx->list_head = new_pipe();
4140 /* Create the memory for command, roughly:
4141 * ctx->pipe->cmds = new struct command;
4142 * ctx->command = &ctx->pipe->cmds[0];
4147 /* If a reserved word is found and processed, parse context is modified
4148 * and 1 is returned.
4151 struct reserved_combo {
4154 unsigned char assignment_flag;
4158 FLAG_END = (1 << RES_NONE ),
4160 FLAG_IF = (1 << RES_IF ),
4161 FLAG_THEN = (1 << RES_THEN ),
4162 FLAG_ELIF = (1 << RES_ELIF ),
4163 FLAG_ELSE = (1 << RES_ELSE ),
4164 FLAG_FI = (1 << RES_FI ),
4166 #if ENABLE_HUSH_LOOPS
4167 FLAG_FOR = (1 << RES_FOR ),
4168 FLAG_WHILE = (1 << RES_WHILE),
4169 FLAG_UNTIL = (1 << RES_UNTIL),
4170 FLAG_DO = (1 << RES_DO ),
4171 FLAG_DONE = (1 << RES_DONE ),
4172 FLAG_IN = (1 << RES_IN ),
4174 #if ENABLE_HUSH_CASE
4175 FLAG_MATCH = (1 << RES_MATCH),
4176 FLAG_ESAC = (1 << RES_ESAC ),
4178 FLAG_START = (1 << RES_XXXX ),
4181 static const struct reserved_combo* match_reserved_word(o_string *word)
4183 /* Mostly a list of accepted follow-up reserved words.
4184 * FLAG_END means we are done with the sequence, and are ready
4185 * to turn the compound list into a command.
4186 * FLAG_START means the word must start a new compound list.
4188 static const struct reserved_combo reserved_list[] = {
4190 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
4191 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
4192 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
4193 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
4194 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
4195 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
4197 #if ENABLE_HUSH_LOOPS
4198 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
4199 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4200 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
4201 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
4202 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
4203 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
4205 #if ENABLE_HUSH_CASE
4206 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
4207 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
4210 const struct reserved_combo *r;
4212 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
4213 if (strcmp(word->data, r->literal) == 0)
4218 /* Return 0: not a keyword, 1: keyword
4220 static int reserved_word(o_string *word, struct parse_context *ctx)
4222 #if ENABLE_HUSH_CASE
4223 static const struct reserved_combo reserved_match = {
4224 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
4227 const struct reserved_combo *r;
4231 r = match_reserved_word(word);
4235 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
4236 #if ENABLE_HUSH_CASE
4237 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE)
4238 /* "case word IN ..." - IN part starts first match part */
4239 r = &reserved_match;
4242 if (r->flag == 0) { /* '!' */
4243 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
4244 syntax_error("! ! command");
4245 ctx->ctx_res_w = RES_SNTX;
4247 ctx->ctx_inverted = 1;
4250 if (r->flag & FLAG_START) {
4251 struct parse_context *old;
4253 old = xmalloc(sizeof(*old));
4254 debug_printf_parse("push stack %p\n", old);
4255 *old = *ctx; /* physical copy */
4256 initialize_context(ctx);
4258 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
4259 syntax_error_at(word->data);
4260 ctx->ctx_res_w = RES_SNTX;
4263 /* "{...} fi" is ok. "{...} if" is not
4265 * if { echo foo; } then { echo bar; } fi */
4266 if (ctx->command->group)
4267 done_pipe(ctx, PIPE_SEQ);
4270 ctx->ctx_res_w = r->res;
4271 ctx->old_flag = r->flag;
4272 word->o_assignment = r->assignment_flag;
4274 if (ctx->old_flag & FLAG_END) {
4275 struct parse_context *old;
4277 done_pipe(ctx, PIPE_SEQ);
4278 debug_printf_parse("pop stack %p\n", ctx->stack);
4280 old->command->group = ctx->list_head;
4281 old->command->grp_type = GRP_NORMAL;
4283 o_addstr(&old->as_string, ctx->as_string.data);
4284 o_free_unsafe(&ctx->as_string);
4285 old->command->group_as_string = xstrdup(old->as_string.data);
4286 debug_printf_parse("pop, remembering as:'%s'\n",
4287 old->command->group_as_string);
4289 *ctx = *old; /* physical copy */
4296 /* Word is complete, look at it and update parsing context.
4297 * Normal return is 0. Syntax errors return 1.
4298 * Note: on return, word is reset, but not o_free'd!
4300 static int done_word(o_string *word, struct parse_context *ctx)
4302 struct command *command = ctx->command;
4304 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
4305 if (word->length == 0 && word->o_quoted == 0) {
4306 debug_printf_parse("done_word return 0: true null, ignored\n");
4310 if (ctx->pending_redirect) {
4311 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
4312 * only if run as "bash", not "sh" */
4313 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4315 * ...the word that follows the redirection operator
4316 * shall be subjected to tilde expansion, parameter expansion,
4317 * command substitution, arithmetic expansion, and quote
4318 * removal. Pathname expansion shall not be performed
4319 * on the word by a non-interactive shell; an interactive
4320 * shell may perform it, but shall do so only when
4321 * the expansion would result in one word."
4323 ctx->pending_redirect->rd_filename = xstrdup(word->data);
4324 /* Cater for >\file case:
4325 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
4326 * Same with heredocs:
4327 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
4329 unbackslash(ctx->pending_redirect->rd_filename);
4330 /* Is it <<"HEREDOC"? */
4331 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC
4334 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
4336 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
4337 ctx->pending_redirect = NULL;
4339 /* If this word wasn't an assignment, next ones definitely
4340 * can't be assignments. Even if they look like ones. */
4341 if (word->o_assignment != DEFINITELY_ASSIGNMENT
4342 && word->o_assignment != WORD_IS_KEYWORD
4344 word->o_assignment = NOT_ASSIGNMENT;
4346 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
4347 command->assignment_cnt++;
4348 word->o_assignment = MAYBE_ASSIGNMENT;
4352 # if ENABLE_HUSH_CASE
4353 if (ctx->ctx_dsemicolon
4354 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
4356 /* already done when ctx_dsemicolon was set to 1: */
4357 /* ctx->ctx_res_w = RES_MATCH; */
4358 ctx->ctx_dsemicolon = 0;
4361 if (!command->argv /* if it's the first word... */
4362 # if ENABLE_HUSH_LOOPS
4363 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
4364 && ctx->ctx_res_w != RES_IN
4367 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
4368 if (reserved_word(word, ctx)) {
4369 o_reset_to_empty_unquoted(word);
4370 debug_printf_parse("done_word return %d\n",
4371 (ctx->ctx_res_w == RES_SNTX));
4372 return (ctx->ctx_res_w == RES_SNTX);
4376 if (command->group) {
4377 /* "{ echo foo; } echo bar" - bad */
4378 syntax_error_at(word->data);
4379 debug_printf_parse("done_word return 1: syntax error, "
4380 "groups and arglists don't mix\n");
4383 if (word->o_quoted /* word had "xx" or 'xx' at least as part of it. */
4384 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
4385 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
4386 /* (otherwise it's known to be not empty and is already safe) */
4388 /* exclude "$@" - it can expand to no word despite "" */
4389 char *p = word->data;
4390 while (p[0] == SPECIAL_VAR_SYMBOL
4391 && (p[1] & 0x7f) == '@'
4392 && p[2] == SPECIAL_VAR_SYMBOL
4396 if (p == word->data || p[0] != '\0') {
4397 /* saw no "$@", or not only "$@" but some
4398 * real text is there too */
4399 /* insert "empty variable" reference, this makes
4400 * e.g. "", $empty"" etc to not disappear */
4401 o_addchr(word, SPECIAL_VAR_SYMBOL);
4402 o_addchr(word, SPECIAL_VAR_SYMBOL);
4405 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
4406 //SEGV, but good idea.
4407 // command->argv = add_string_to_strings(command->argv, word->data);
4408 // word->data = NULL;
4409 // word->length = 0;
4410 debug_print_strings("word appended to argv", command->argv);
4413 #if ENABLE_HUSH_LOOPS
4414 if (ctx->ctx_res_w == RES_FOR) {
4416 || !is_well_formed_var_name(command->argv[0], '\0')
4418 /* bash says just "not a valid identifier" */
4419 syntax_error("not a valid identifier in for");
4422 /* Force FOR to have just one word (variable name) */
4423 /* NB: basically, this makes hush see "for v in ..."
4424 * syntax as if it is "for v; in ...". FOR and IN become
4425 * two pipe structs in parse tree. */
4426 done_pipe(ctx, PIPE_SEQ);
4429 #if ENABLE_HUSH_CASE
4430 /* Force CASE to have just one word */
4431 if (ctx->ctx_res_w == RES_CASE) {
4432 done_pipe(ctx, PIPE_SEQ);
4436 o_reset_to_empty_unquoted(word);
4438 debug_printf_parse("done_word return 0\n");
4443 /* Peek ahead in the input to find out if we have a "&n" construct,
4444 * as in "2>&1", that represents duplicating a file descriptor.
4446 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
4447 * REDIRFD_SYNTAX_ERR if syntax error,
4448 * REDIRFD_TO_FILE if no & was seen,
4449 * or the number found.
4452 #define parse_redir_right_fd(as_string, input) \
4453 parse_redir_right_fd(input)
4455 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
4461 return REDIRFD_TO_FILE;
4463 ch = i_getch(input); /* get the & */
4464 nommu_addchr(as_string, ch);
4467 ch = i_getch(input);
4468 nommu_addchr(as_string, ch);
4469 return REDIRFD_CLOSE;
4473 while (ch != EOF && isdigit(ch)) {
4474 d = d*10 + (ch-'0');
4476 ch = i_getch(input);
4477 nommu_addchr(as_string, ch);
4482 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
4484 bb_error_msg("ambiguous redirect");
4485 return REDIRFD_SYNTAX_ERR;
4488 /* Return code is 0 normal, 1 if a syntax error is detected
4490 static int parse_redirect(struct parse_context *ctx,
4493 struct in_str *input)
4495 struct command *command = ctx->command;
4496 struct redir_struct *redir;
4497 struct redir_struct **redirp;
4500 dup_num = REDIRFD_TO_FILE;
4501 if (style != REDIRECT_HEREDOC) {
4502 /* Check for a '>&1' type redirect */
4503 dup_num = parse_redir_right_fd(&ctx->as_string, input);
4504 if (dup_num == REDIRFD_SYNTAX_ERR)
4507 int ch = i_peek(input);
4508 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
4509 if (dup_num) { /* <<-... */
4510 ch = i_getch(input);
4511 nommu_addchr(&ctx->as_string, ch);
4516 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
4517 int ch = i_peek(input);
4519 /* >|FILE redirect ("clobbering" >).
4520 * Since we do not support "set -o noclobber" yet,
4521 * >| and > are the same for now. Just eat |.
4523 ch = i_getch(input);
4524 nommu_addchr(&ctx->as_string, ch);
4528 /* Create a new redir_struct and append it to the linked list */
4529 redirp = &command->redirects;
4530 while ((redir = *redirp) != NULL) {
4531 redirp = &(redir->next);
4533 *redirp = redir = xzalloc(sizeof(*redir));
4534 /* redir->next = NULL; */
4535 /* redir->rd_filename = NULL; */
4536 redir->rd_type = style;
4537 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
4539 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
4540 redir_table[style].descrip);
4542 redir->rd_dup = dup_num;
4543 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
4544 /* Erik had a check here that the file descriptor in question
4545 * is legit; I postpone that to "run time"
4546 * A "-" representation of "close me" shows up as a -3 here */
4547 debug_printf_parse("duplicating redirect '%d>&%d'\n",
4548 redir->rd_fd, redir->rd_dup);
4550 /* Set ctx->pending_redirect, so we know what to do at the
4551 * end of the next parsed word. */
4552 ctx->pending_redirect = redir;
4557 /* If a redirect is immediately preceded by a number, that number is
4558 * supposed to tell which file descriptor to redirect. This routine
4559 * looks for such preceding numbers. In an ideal world this routine
4560 * needs to handle all the following classes of redirects...
4561 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4562 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4563 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4564 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4566 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4568 * ... If n is quoted, the number shall not be recognized as part of
4569 * the redirection expression. For example:
4571 * writes the character 2 into file a"
4572 * We are getting it right by setting ->o_quoted on any \<char>
4574 * A -1 return means no valid number was found,
4575 * the caller should use the appropriate default for this redirection.
4577 static int redirect_opt_num(o_string *o)
4581 if (o->data == NULL)
4583 num = bb_strtou(o->data, NULL, 10);
4584 if (errno || num < 0)
4586 o_reset_to_empty_unquoted(o);
4591 #define fetch_till_str(as_string, input, word, skip_tabs) \
4592 fetch_till_str(input, word, skip_tabs)
4594 static char *fetch_till_str(o_string *as_string,
4595 struct in_str *input,
4599 o_string heredoc = NULL_O_STRING;
4605 ch = i_getch(input);
4606 nommu_addchr(as_string, ch);
4608 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4609 heredoc.data[past_EOL] = '\0';
4610 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4611 return heredoc.data;
4614 o_addchr(&heredoc, ch);
4615 past_EOL = heredoc.length;
4618 ch = i_getch(input);
4619 nommu_addchr(as_string, ch);
4620 } while (skip_tabs && ch == '\t');
4621 } while (ch == '\n');
4624 o_free_unsafe(&heredoc);
4627 o_addchr(&heredoc, ch);
4628 nommu_addchr(as_string, ch);
4632 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4633 * and load them all. There should be exactly heredoc_cnt of them.
4635 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4637 struct pipe *pi = ctx->list_head;
4639 while (pi && heredoc_cnt) {
4641 struct command *cmd = pi->cmds;
4643 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4645 cmd->argv ? cmd->argv[0] : "NONE");
4646 for (i = 0; i < pi->num_cmds; i++) {
4647 struct redir_struct *redir = cmd->redirects;
4649 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4650 i, cmd->argv ? cmd->argv[0] : "NONE");
4652 if (redir->rd_type == REDIRECT_HEREDOC) {
4655 redir->rd_type = REDIRECT_HEREDOC2;
4656 /* redir->dup is (ab)used to indicate <<- */
4657 p = fetch_till_str(&ctx->as_string, input,
4658 redir->rd_filename, redir->rd_dup & HEREDOC_SKIPTABS);
4660 syntax_error("unexpected EOF in here document");
4663 free(redir->rd_filename);
4664 redir->rd_filename = p;
4667 redir = redir->next;
4674 /* Should be 0. If it isn't, it's a parse error */
4676 bb_error_msg_and_die("heredoc BUG 2");
4682 #if ENABLE_HUSH_TICK
4683 static FILE *generate_stream_from_string(const char *s)
4686 int pid, channel[2];
4692 pid = BB_MMU ? fork() : vfork();
4694 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
4696 if (pid == 0) { /* child */
4697 disable_restore_tty_pgrp_on_exit();
4698 /* Process substitution is not considered to be usual
4699 * 'command execution'.
4700 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
4707 close(channel[0]); /* NB: close _first_, then move fd! */
4708 xmove_fd(channel[1], 1);
4709 /* Prevent it from trying to handle ctrl-z etc */
4710 USE_HUSH_JOB(G.run_list_level = 1;)
4712 reset_traps_to_defaults();
4713 parse_and_run_string(s);
4714 _exit(G.last_exitcode);
4716 /* We re-execute after vfork on NOMMU. This makes this script safe:
4717 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
4718 * huge=`cat BIG` # was blocking here forever
4721 re_execute_shell(&to_free,
4729 enable_restore_tty_pgrp_on_exit();
4734 pf = fdopen(channel[0], "r");
4738 /* Return code is exit status of the process that is run. */
4739 static int process_command_subs(o_string *dest, const char *s)
4742 struct in_str pipe_str;
4745 pf = generate_stream_from_string(s);
4748 close_on_exec_on(fileno(pf));
4750 /* Now send results of command back into original context */
4751 setup_file_in_str(&pipe_str, pf);
4753 while ((ch = i_getch(&pipe_str)) != EOF) {
4759 o_addchr(dest, '\n');
4762 o_addQchr(dest, ch);
4765 debug_printf("done reading from pipe, pclose()ing\n");
4766 /* Note: we got EOF, and we just close the read end of the pipe.
4767 * We do not wait for the `cmd` child to terminate. bash and ash do.
4769 * echo `echo Hi; exec 1>&-; sleep 2` - bash waits 2 sec
4770 * `false`; echo $? - bash outputs "1"
4773 debug_printf("closed FILE from child. return 0\n");
4778 static int parse_group(o_string *dest, struct parse_context *ctx,
4779 struct in_str *input, int ch)
4781 /* dest contains characters seen prior to ( or {.
4782 * Typically it's empty, but for function defs,
4783 * it contains function name (without '()'). */
4784 struct pipe *pipe_list;
4786 struct command *command = ctx->command;
4788 debug_printf_parse("parse_group entered\n");
4789 #if ENABLE_HUSH_FUNCTIONS
4790 if (ch == '(' && !dest->o_quoted) {
4792 if (done_word(dest, ctx))
4795 goto skip; /* (... */
4796 if (command->argv[1]) { /* word word ... (... */
4797 syntax_error_unexpected_ch('(');
4800 /* it is "word(..." or "word (..." */
4802 ch = i_getch(input);
4803 while (ch == ' ' || ch == '\t');
4805 syntax_error_unexpected_ch(ch);
4808 nommu_addchr(&ctx->as_string, ch);
4810 ch = i_getch(input);
4811 while (ch == ' ' || ch == '\t' || ch == '\n');
4813 syntax_error_unexpected_ch(ch);
4816 nommu_addchr(&ctx->as_string, ch);
4817 command->grp_type = GRP_FUNCTION;
4821 if (command->argv /* word [word]{... */
4822 || dest->length /* word{... */
4823 || dest->o_quoted /* ""{... */
4826 debug_printf_parse("parse_group return 1: "
4827 "syntax error, groups and arglists don't mix\n");
4831 #if ENABLE_HUSH_FUNCTIONS
4837 command->grp_type = GRP_SUBSHELL;
4839 /* bash does not allow "{echo...", requires whitespace */
4840 ch = i_getch(input);
4841 if (ch != ' ' && ch != '\t' && ch != '\n') {
4842 syntax_error_unexpected_ch(ch);
4845 nommu_addchr(&ctx->as_string, ch);
4850 char *as_string = NULL;
4852 pipe_list = parse_stream(&as_string, input, endch);
4855 o_addstr(&ctx->as_string, as_string);
4857 /* empty ()/{} or parse error? */
4858 if (!pipe_list || pipe_list == ERR_PTR) {
4859 /* parse_stream already emitted error msg */
4863 debug_printf_parse("parse_group return 1: "
4864 "parse_stream returned %p\n", pipe_list);
4867 command->group = pipe_list;
4869 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4870 command->group_as_string = as_string;
4871 debug_printf_parse("end of group, remembering as:'%s'\n",
4872 command->group_as_string);
4875 debug_printf_parse("parse_group return 0\n");
4877 /* command remains "open", available for possible redirects */
4880 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT
4881 /* Subroutines for copying $(...) and `...` things */
4882 static void add_till_backquote(o_string *dest, struct in_str *input);
4884 static void add_till_single_quote(o_string *dest, struct in_str *input)
4887 int ch = i_getch(input);
4889 syntax_error_unterm_ch('\'');
4890 /*xfunc_die(); - redundant */
4897 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4898 static void add_till_double_quote(o_string *dest, struct in_str *input)
4901 int ch = i_getch(input);
4903 syntax_error_unterm_ch('"');
4904 /*xfunc_die(); - redundant */
4908 if (ch == '\\') { /* \x. Copy both chars. */
4910 ch = i_getch(input);
4914 add_till_backquote(dest, input);
4918 //if (ch == '$') ...
4921 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4923 * "Within the backquoted style of command substitution, backslash
4924 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4925 * The search for the matching backquote shall be satisfied by the first
4926 * backquote found without a preceding backslash; during this search,
4927 * if a non-escaped backquote is encountered within a shell comment,
4928 * a here-document, an embedded command substitution of the $(command)
4929 * form, or a quoted string, undefined results occur. A single-quoted
4930 * or double-quoted string that begins, but does not end, within the
4931 * "`...`" sequence produces undefined results."
4933 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4935 static void add_till_backquote(o_string *dest, struct in_str *input)
4938 int ch = i_getch(input);
4940 syntax_error_unterm_ch('`');
4941 /*xfunc_die(); - redundant */
4946 /* \x. Copy both chars unless it is \` */
4947 int ch2 = i_getch(input);
4949 syntax_error_unterm_ch('`');
4950 /*xfunc_die(); - redundant */
4952 if (ch2 != '`' && ch2 != '$' && ch2 != '\\')
4959 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4960 * quoting and nested ()s.
4961 * "With the $(command) style of command substitution, all characters
4962 * following the open parenthesis to the matching closing parenthesis
4963 * constitute the command. Any valid shell script can be used for command,
4964 * except a script consisting solely of redirections which produces
4965 * unspecified results."
4967 * echo $(echo '(TEST)' BEST) (TEST) BEST
4968 * echo $(echo 'TEST)' BEST) TEST) BEST
4969 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4971 static void add_till_closing_paren(o_string *dest, struct in_str *input, bool dbl)
4975 int ch = i_getch(input);
4977 syntax_error_unterm_ch(')');
4978 /*xfunc_die(); - redundant */
4986 if (i_peek(input) == ')') {
4994 add_till_single_quote(dest, input);
4999 add_till_double_quote(dest, input);
5004 /* \x. Copy verbatim. Important for \(, \) */
5005 ch = i_getch(input);
5007 syntax_error_unterm_ch(')');
5008 /*xfunc_die(); - redundant */
5015 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT */
5017 /* Return code: 0 for OK, 1 for syntax error */
5019 #define handle_dollar(as_string, dest, input) \
5020 handle_dollar(dest, input)
5022 static int handle_dollar(o_string *as_string,
5024 struct in_str *input)
5027 int ch = i_peek(input); /* first character after the $ */
5028 unsigned char quote_mask = dest->o_escape ? 0x80 : 0;
5030 debug_printf_parse("handle_dollar entered: ch='%c'\n", ch);
5032 ch = i_getch(input);
5033 nommu_addchr(as_string, ch);
5035 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5037 debug_printf_parse(": '%c'\n", ch);
5038 o_addchr(dest, ch | quote_mask);
5041 if (!isalnum(ch) && ch != '_')
5043 ch = i_getch(input);
5044 nommu_addchr(as_string, ch);
5046 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5047 } else if (isdigit(ch)) {
5049 ch = i_getch(input);
5050 nommu_addchr(as_string, ch);
5051 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5052 debug_printf_parse(": '%c'\n", ch);
5053 o_addchr(dest, ch | quote_mask);
5054 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5055 } else switch (ch) {
5057 case '!': /* last bg pid */
5058 case '?': /* last exit code */
5059 case '#': /* number of args */
5060 case '*': /* args */
5061 case '@': /* args */
5062 goto make_one_char_var;
5064 bool first_char, all_digits;
5066 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5067 ch = i_getch(input);
5068 nommu_addchr(as_string, ch);
5069 /* TODO: maybe someone will try to escape the '}' */
5074 ch = i_getch(input);
5075 nommu_addchr(as_string, ch);
5081 /* ${#var}: length of var contents */
5083 else if (isdigit(ch)) {
5090 && ( (all_digits && !isdigit(ch))
5091 || (!all_digits && !isalnum(ch) && ch != '_')
5094 /* handle parameter expansions
5095 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
5100 case ':': /* null modifier */
5101 if (expansion == 0) {
5102 debug_printf_parse(": null modifier\n");
5107 case '#': /* remove prefix */
5108 case '%': /* remove suffix */
5109 if (expansion == 0) {
5110 debug_printf_parse(": remove suffix/prefix\n");
5115 case '-': /* default value */
5116 case '=': /* assign default */
5117 case '+': /* alternative */
5118 case '?': /* error indicate */
5119 debug_printf_parse(": parameter expansion\n");
5124 syntax_error_unterm_str("${name}");
5125 debug_printf_parse("handle_dollar return 1: unterminated ${name}\n");
5130 debug_printf_parse(": '%c'\n", ch);
5131 o_addchr(dest, ch | quote_mask);
5135 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5138 #if (ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK)
5143 ch = i_getch(input);
5144 nommu_addchr(as_string, ch);
5145 # if ENABLE_SH_MATH_SUPPORT
5146 if (i_peek(input) == '(') {
5147 ch = i_getch(input);
5148 nommu_addchr(as_string, ch);
5149 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5150 o_addchr(dest, /*quote_mask |*/ '+');
5154 add_till_closing_paren(dest, input, true);
5157 o_addstr(as_string, dest->data + pos);
5158 o_addchr(as_string, ')');
5159 o_addchr(as_string, ')');
5162 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5166 # if ENABLE_HUSH_TICK
5167 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5168 o_addchr(dest, quote_mask | '`');
5172 add_till_closing_paren(dest, input, false);
5175 o_addstr(as_string, dest->data + pos);
5176 o_addchr(as_string, '`');
5179 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5185 ch = i_getch(input);
5186 nommu_addchr(as_string, ch);
5188 if (isalnum(ch)) { /* it's $_name or $_123 */
5194 /* $_ Shell or shell script name; or last cmd name */
5195 /* $- Option flags set by set builtin or shell options (-i etc) */
5197 o_addQchr(dest, '$');
5199 debug_printf_parse("handle_dollar return 0\n");
5204 #define parse_stream_dquoted(as_string, dest, input, dquote_end) \
5205 parse_stream_dquoted(dest, input, dquote_end)
5207 static int parse_stream_dquoted(o_string *as_string,
5209 struct in_str *input,
5216 ch = i_getch(input);
5218 nommu_addchr(as_string, ch);
5219 if (ch == dquote_end) { /* may be only '"' or EOF */
5220 if (dest->o_assignment == NOT_ASSIGNMENT)
5221 dest->o_escape ^= 1;
5222 debug_printf_parse("parse_stream_dquoted return 0\n");
5225 /* note: can't move it above ch == dquote_end check! */
5227 syntax_error_unterm_ch('"');
5228 /*xfunc_die(); - redundant */
5232 next = i_peek(input);
5234 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5235 ch, ch, dest->o_escape);
5238 syntax_error("\\<eof>");
5242 * "The backslash retains its special meaning [in "..."]
5243 * only when followed by one of the following characters:
5244 * $, `, ", \, or <newline>. A double quote may be quoted
5245 * within double quotes by preceding it with a backslash.
5247 if (strchr("$`\"\\", next) != NULL) {
5248 o_addqchr(dest, i_getch(input));
5250 o_addqchr(dest, '\\');
5255 if (handle_dollar(as_string, dest, input) != 0) {
5256 debug_printf_parse("parse_stream_dquoted return 1: "
5257 "handle_dollar returned non-0\n");
5262 #if ENABLE_HUSH_TICK
5264 //int pos = dest->length;
5265 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5266 o_addchr(dest, 0x80 | '`');
5267 add_till_backquote(dest, input);
5268 o_addchr(dest, SPECIAL_VAR_SYMBOL);
5269 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
5273 o_addQchr(dest, ch);
5275 && (dest->o_assignment == MAYBE_ASSIGNMENT
5276 || dest->o_assignment == WORD_IS_KEYWORD)
5277 && is_well_formed_var_name(dest->data, '=')
5279 dest->o_assignment = DEFINITELY_ASSIGNMENT;
5285 * Scan input until EOF or end_trigger char.
5286 * Return a list of pipes to execute, or NULL on EOF
5287 * or if end_trigger character is met.
5288 * On syntax error, exit is shell is not interactive,
5289 * reset parsing machinery and start parsing anew,
5290 * or return ERR_PTR.
5292 static struct pipe *parse_stream(char **pstring,
5293 struct in_str *input,
5296 struct parse_context ctx;
5297 o_string dest = NULL_O_STRING;
5301 /* Double-quote state is handled in the state variable is_in_dquote.
5302 * A single-quote triggers a bypass of the main loop until its mate is
5303 * found. When recursing, quote state is passed in via dest->o_escape.
5305 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
5306 end_trigger ? : 'X');
5309 G.ifs = get_local_var_value("IFS");
5314 #if ENABLE_HUSH_INTERACTIVE
5315 input->promptmode = 0; /* PS1 */
5317 /* dest.o_assignment = MAYBE_ASSIGNMENT; - already is */
5318 initialize_context(&ctx);
5323 const char *is_special;
5327 redir_type redir_style;
5330 /* dest.o_quoted = 1; - already is (see below) */
5331 if (parse_stream_dquoted(&ctx.as_string, &dest, input, '"')) {
5334 /* We reached closing '"' */
5337 ch = i_getch(input);
5338 debug_printf_parse(": ch=%c (%d) escape=%d\n",
5339 ch, ch, dest.o_escape);
5344 syntax_error_unterm_str("here document");
5347 if (done_word(&dest, &ctx)) {
5351 done_pipe(&ctx, PIPE_SEQ);
5353 /* If we got nothing... */
5354 /* (this makes bare "&" cmd a no-op.
5355 * bash says: "syntax error near unexpected token '&'") */
5356 if (pi->num_cmds == 0
5357 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
5363 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5365 *pstring = ctx.as_string.data;
5367 o_free_unsafe(&ctx.as_string);
5370 debug_printf_parse("parse_stream return %p\n", pi);
5373 nommu_addchr(&ctx.as_string, ch);
5374 is_ifs = strchr(G.ifs, ch);
5375 is_special = strchr("<>;&|(){}#'" /* special outside of "str" */
5376 "\\$\"" USE_HUSH_TICK("`") /* always special */
5379 if (!is_special && !is_ifs) { /* ordinary char */
5380 o_addQchr(&dest, ch);
5381 if ((dest.o_assignment == MAYBE_ASSIGNMENT
5382 || dest.o_assignment == WORD_IS_KEYWORD)
5384 && is_well_formed_var_name(dest.data, '=')
5386 dest.o_assignment = DEFINITELY_ASSIGNMENT;
5392 if (done_word(&dest, &ctx)) {
5396 #if ENABLE_HUSH_CASE
5397 /* "case ... in <newline> word) ..." -
5398 * newlines are ignored (but ';' wouldn't be) */
5399 if (ctx.command->argv == NULL
5400 && ctx.ctx_res_w == RES_MATCH
5405 /* Treat newline as a command separator. */
5406 done_pipe(&ctx, PIPE_SEQ);
5407 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
5409 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
5414 dest.o_assignment = MAYBE_ASSIGNMENT;
5416 /* note: if (is_ifs) continue;
5417 * will still trigger for us */
5420 if (end_trigger && end_trigger == ch
5421 && (heredoc_cnt == 0 || end_trigger != ';')
5424 /* This is technically valid:
5425 * { cat <<HERE; }; echo Ok
5429 * but we don't support this.
5430 * We require heredoc to be in enclosing {}/(),
5433 syntax_error_unterm_str("here document");
5436 if (done_word(&dest, &ctx)) {
5439 /* Disallow "{ cmd }" without semicolon or & */
5440 //debug_printf_parse("null pi %d\n", IS_NULL_PIPE(ctx.pipe))
5441 //debug_printf_parse("null cmd %d\n", IS_NULL_CMD(ctx.command))
5443 && !(IS_NULL_PIPE(ctx.pipe) && IS_NULL_CMD(ctx.command))
5445 syntax_error_unexpected_ch(ch);
5448 done_pipe(&ctx, PIPE_SEQ);
5449 dest.o_assignment = MAYBE_ASSIGNMENT;
5450 /* Do we sit outside of any if's, loops or case's? */
5452 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5456 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
5458 *pstring = ctx.as_string.data;
5460 o_free_unsafe(&ctx.as_string);
5463 debug_printf_parse("parse_stream return %p: "
5464 "end_trigger char found\n",
5466 return ctx.list_head;
5474 next = i_peek(input);
5477 /* Catch <, > before deciding whether this word is
5478 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5481 redir_fd = redirect_opt_num(&dest);
5482 if (done_word(&dest, &ctx)) {
5485 redir_style = REDIRECT_OVERWRITE;
5487 redir_style = REDIRECT_APPEND;
5488 ch = i_getch(input);
5489 nommu_addchr(&ctx.as_string, ch);
5492 else if (next == '(') {
5493 syntax_error(">(process) not supported");
5497 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5499 continue; /* back to top of while (1) */
5501 redir_fd = redirect_opt_num(&dest);
5502 if (done_word(&dest, &ctx)) {
5505 redir_style = REDIRECT_INPUT;
5507 redir_style = REDIRECT_HEREDOC;
5509 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5510 ch = i_getch(input);
5511 nommu_addchr(&ctx.as_string, ch);
5512 } else if (next == '>') {
5513 redir_style = REDIRECT_IO;
5514 ch = i_getch(input);
5515 nommu_addchr(&ctx.as_string, ch);
5518 else if (next == '(') {
5519 syntax_error("<(process) not supported");
5523 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5525 continue; /* back to top of while (1) */
5528 if (dest.o_assignment == MAYBE_ASSIGNMENT
5529 /* check that we are not in word in "a=1 2>word b=1": */
5530 && !ctx.pending_redirect
5532 /* ch is a special char and thus this word
5533 * cannot be an assignment */
5534 dest.o_assignment = NOT_ASSIGNMENT;
5539 if (dest.length == 0) {
5542 if (ch == EOF || ch == '\n')
5545 /* note: we do not add it to &ctx.as_string */
5547 nommu_addchr(&ctx.as_string, '\n');
5549 o_addQchr(&dest, ch);
5554 syntax_error("\\<eof>");
5557 o_addchr(&dest, '\\');
5558 ch = i_getch(input);
5559 nommu_addchr(&ctx.as_string, ch);
5560 o_addchr(&dest, ch);
5561 /* Example: echo Hello \2>file
5562 * we need to know that word 2 is quoted */
5566 if (handle_dollar(&ctx.as_string, &dest, input) != 0) {
5567 debug_printf_parse("parse_stream parse error: "
5568 "handle_dollar returned non-0\n");
5575 ch = i_getch(input);
5577 syntax_error_unterm_ch('\'');
5578 /*xfunc_die(); - redundant */
5580 nommu_addchr(&ctx.as_string, ch);
5583 if (dest.o_assignment == NOT_ASSIGNMENT)
5584 o_addqchr(&dest, ch);
5586 o_addchr(&dest, ch);
5591 is_in_dquote ^= 1; /* invert */
5592 if (dest.o_assignment == NOT_ASSIGNMENT)
5595 #if ENABLE_HUSH_TICK
5600 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5601 o_addchr(&dest, '`');
5605 add_till_backquote(&dest, input);
5607 o_addstr(&ctx.as_string, dest.data + pos);
5608 o_addchr(&ctx.as_string, '`');
5610 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5611 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5616 #if ENABLE_HUSH_CASE
5619 if (done_word(&dest, &ctx)) {
5622 done_pipe(&ctx, PIPE_SEQ);
5623 #if ENABLE_HUSH_CASE
5624 /* Eat multiple semicolons, detect
5625 * whether it means something special */
5630 ch = i_getch(input);
5631 nommu_addchr(&ctx.as_string, ch);
5632 if (ctx.ctx_res_w == RES_CASEI) {
5633 ctx.ctx_dsemicolon = 1;
5634 ctx.ctx_res_w = RES_MATCH;
5640 /* We just finished a cmd. New one may start
5641 * with an assignment */
5642 dest.o_assignment = MAYBE_ASSIGNMENT;
5645 if (done_word(&dest, &ctx)) {
5649 ch = i_getch(input);
5650 nommu_addchr(&ctx.as_string, ch);
5651 done_pipe(&ctx, PIPE_AND);
5653 done_pipe(&ctx, PIPE_BG);
5657 if (done_word(&dest, &ctx)) {
5660 #if ENABLE_HUSH_CASE
5661 if (ctx.ctx_res_w == RES_MATCH)
5662 break; /* we are in case's "word | word)" */
5664 if (next == '|') { /* || */
5665 ch = i_getch(input);
5666 nommu_addchr(&ctx.as_string, ch);
5667 done_pipe(&ctx, PIPE_OR);
5669 /* we could pick up a file descriptor choice here
5670 * with redirect_opt_num(), but bash doesn't do it.
5671 * "echo foo 2| cat" yields "foo 2". */
5676 #if ENABLE_HUSH_CASE
5677 /* "case... in [(]word)..." - skip '(' */
5678 if (ctx.ctx_res_w == RES_MATCH
5679 && ctx.command->argv == NULL /* not (word|(... */
5680 && dest.length == 0 /* not word(... */
5681 && dest.o_quoted == 0 /* not ""(... */
5687 if (parse_group(&dest, &ctx, input, ch) != 0) {
5692 #if ENABLE_HUSH_CASE
5693 if (ctx.ctx_res_w == RES_MATCH)
5697 /* proper use of this character is caught by end_trigger:
5698 * if we see {, we call parse_group(..., end_trigger='}')
5699 * and it will match } earlier (not here). */
5700 syntax_error_unexpected_ch(ch);
5704 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5710 struct parse_context *pctx;
5711 IF_HAS_KEYWORDS(struct parse_context *p2;)
5713 /* Clean up allocated tree.
5714 * Samples for finding leaks on syntax error recovery path.
5715 * Run them from interactive shell, watch pmap `pidof hush`.
5716 * while if false; then false; fi do break; done
5718 * while if false; then false; fi; do break; fi
5719 * Samples to catch leaks at execution:
5720 * while if (true | {true;}); then echo ok; fi; do break; done
5721 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5725 /* Update pipe/command counts,
5726 * otherwise freeing may miss some */
5727 done_pipe(pctx, PIPE_SEQ);
5728 debug_printf_clean("freeing list %p from ctx %p\n",
5729 pctx->list_head, pctx);
5730 debug_print_tree(pctx->list_head, 0);
5731 free_pipe_list(pctx->list_head);
5732 debug_printf_clean("freed list %p\n", pctx->list_head);
5734 o_free_unsafe(&pctx->as_string);
5736 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5740 IF_HAS_KEYWORDS(pctx = p2;)
5741 } while (HAS_KEYWORDS && pctx);
5742 /* Free text, clear all dest fields */
5744 /* If we are not in top-level parse, we return,
5745 * our caller will propagate error.
5747 if (end_trigger != ';') {
5755 /* Discard cached input, force prompt */
5757 USE_HUSH_INTERACTIVE(input->promptme = 1;)
5762 /* Executing from string: eval, sh -c '...'
5763 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5764 * end_trigger controls how often we stop parsing
5765 * NUL: parse all, execute, return
5766 * ';': parse till ';' or newline, execute, repeat till EOF
5768 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5771 struct pipe *pipe_list;
5773 pipe_list = parse_stream(NULL, inp, end_trigger);
5774 if (!pipe_list) /* EOF */
5776 debug_print_tree(pipe_list, 0);
5777 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5778 run_and_free_list(pipe_list);
5782 static void parse_and_run_string(const char *s)
5784 struct in_str input;
5785 setup_string_in_str(&input, s);
5786 parse_and_run_stream(&input, '\0');
5789 static void parse_and_run_file(FILE *f)
5791 struct in_str input;
5792 setup_file_in_str(&input, f);
5793 parse_and_run_stream(&input, ';');
5796 /* Called a few times only (or even once if "sh -c") */
5797 static void block_signals(int second_time)
5802 mask = (1 << SIGQUIT);
5803 if (G_interactive_fd)
5804 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
5805 G.non_DFL_mask = mask;
5808 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
5812 sigaddset(&G.blocked_set, sig);
5816 sigdelset(&G.blocked_set, SIGCHLD);
5818 sigprocmask(SIG_SETMASK, &G.blocked_set,
5819 second_time ? NULL : &G.inherited_set);
5820 /* POSIX allows shell to re-enable SIGCHLD
5821 * even if it was SIG_IGN on entry */
5822 // G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
5824 signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
5829 static void maybe_set_to_sigexit(int sig)
5831 void (*handler)(int);
5832 /* non_DFL_mask'ed signals are, well, masked,
5833 * no need to set handler for them.
5835 if (!((G.non_DFL_mask >> sig) & 1)) {
5836 handler = signal(sig, sigexit);
5837 if (handler == SIG_IGN) /* oops... restore back to IGN! */
5838 signal(sig, handler);
5841 /* Set handlers to restore tty pgrp and exit */
5842 static void set_fatal_handlers(void)
5844 /* We _must_ restore tty pgrp on fatal signals */
5846 maybe_set_to_sigexit(SIGILL );
5847 maybe_set_to_sigexit(SIGFPE );
5848 maybe_set_to_sigexit(SIGBUS );
5849 maybe_set_to_sigexit(SIGSEGV);
5850 maybe_set_to_sigexit(SIGTRAP);
5851 } /* else: hush is perfect. what SEGV? */
5852 maybe_set_to_sigexit(SIGABRT);
5853 /* bash 3.2 seems to handle these just like 'fatal' ones */
5854 maybe_set_to_sigexit(SIGPIPE);
5855 maybe_set_to_sigexit(SIGALRM);
5856 //TODO: disable and move down when proper SIGHUP handling is added
5857 maybe_set_to_sigexit(SIGHUP );
5858 /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked.
5859 * if we aren't interactive... but in this case
5860 * we never want to restore pgrp on exit, and this fn is not called */
5861 /*maybe_set_to_sigexit(SIGTERM);*/
5862 /*maybe_set_to_sigexit(SIGINT );*/
5866 static int set_mode(const char cstate, const char mode)
5868 int state = (cstate == '-' ? 1 : 0);
5870 case 'n': G.fake_mode = state; break;
5871 case 'x': /*G.debug_mode = state;*/ break;
5872 default: return EXIT_FAILURE;
5874 return EXIT_SUCCESS;
5877 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
5878 int hush_main(int argc, char **argv)
5880 static const struct variable const_shell_ver = {
5882 .varstr = (char*)hush_version_str,
5883 .max_len = 1, /* 0 can provoke free(name) */
5887 int signal_mask_is_inited = 0;
5890 struct variable *cur_var;
5893 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
5894 G.last_exitcode = EXIT_SUCCESS;
5896 G.argv0_for_re_execing = argv[0];
5898 /* Deal with HUSH_VERSION */
5899 G.shell_ver = const_shell_ver; /* copying struct here */
5900 G.top_var = &G.shell_ver;
5901 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
5902 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
5903 /* Initialize our shell local variables with the values
5904 * currently living in the environment */
5905 cur_var = G.top_var;
5908 char *value = strchr(*e, '=');
5909 if (value) { /* paranoia */
5910 cur_var->next = xzalloc(sizeof(*cur_var));
5911 cur_var = cur_var->next;
5912 cur_var->varstr = *e;
5913 cur_var->max_len = strlen(*e);
5914 cur_var->flg_export = 1;
5918 debug_printf_env("putenv '%s'\n", hush_version_str);
5919 putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
5920 #if ENABLE_FEATURE_EDITING
5921 G.line_input_state = new_line_input_t(FOR_SHELL);
5923 G.global_argc = argc;
5924 G.global_argv = argv;
5925 /* Initialize some more globals to non-zero values */
5927 #if ENABLE_HUSH_INTERACTIVE
5928 if (ENABLE_FEATURE_EDITING)
5929 cmdedit_set_initial_prompt();
5933 if (setjmp(die_jmp)) {
5934 /* xfunc has failed! die die die */
5935 /* no EXIT traps, this is an escape hatch! */
5937 hush_exit(xfunc_error_retval);
5940 /* Shell is non-interactive at first. We need to call
5941 * block_signals(0) if we are going to execute "sh <script>",
5942 * "sh -c <cmds>" or login shell's /etc/profile and friends.
5943 * If we later decide that we are interactive, we run block_signals(0)
5944 * (or re-run block_signals(1) if we ran block_signals(0) before)
5945 * in order to intercept (more) signals.
5949 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
5951 opt = getopt(argc, argv, "c:xins"
5954 # if ENABLE_HUSH_FUNCTIONS
5964 G.root_pid = getpid();
5965 G.global_argv = argv + optind;
5966 if (!argv[optind]) {
5967 /* -c 'script' (no params): prevent empty $0 */
5968 *--G.global_argv = argv[0];
5970 } /* else -c 'script' PAR0 PAR1: $0 is PAR0 */
5971 G.global_argc = argc - optind;
5972 block_signals(0); /* 0: called 1st time */
5973 parse_and_run_string(optarg);
5976 /* Well, we cannot just declare interactiveness,
5977 * we have to have some stuff (ctty, etc) */
5978 /* G_interactive_fd++; */
5981 /* "-s" means "read from stdin", but this is how we always
5982 * operate, so simply do nothing here. */
5985 case '<': /* "big heredoc" support */
5986 full_write(STDOUT_FILENO, optarg, strlen(optarg));
5989 G.root_pid = bb_strtou(optarg, &optarg, 16);
5991 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
5993 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
5994 # if ENABLE_HUSH_LOOPS
5996 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
6001 set_local_var(xstrdup(optarg), 0, opt == 'R');
6003 # if ENABLE_HUSH_FUNCTIONS
6005 struct function *funcp = new_function(optarg);
6006 /* funcp->name is already set to optarg */
6007 /* funcp->body is set to NULL. It's a special case. */
6008 funcp->body_as_string = argv[optind];
6016 if (!set_mode('-', opt))
6020 fprintf(stderr, "Usage: sh [FILE]...\n"
6021 " or: sh -c command [args]...\n\n");
6027 } /* option parsing loop */
6030 G.root_pid = getpid();
6032 /* If we are login shell... */
6033 if (argv[0] && argv[0][0] == '-') {
6035 /* TODO: what should argv be while sourcing /etc/profile? */
6036 debug_printf("sourcing /etc/profile\n");
6037 input = fopen_for_read("/etc/profile");
6038 if (input != NULL) {
6039 close_on_exec_on(fileno(input));
6040 block_signals(0); /* 0: called 1st time */
6041 signal_mask_is_inited = 1;
6042 parse_and_run_file(input);
6045 /* bash: after sourcing /etc/profile,
6046 * tries to source (in the given order):
6047 * ~/.bash_profile, ~/.bash_login, ~/.profile,
6048 * stopping of first found. --noprofile turns this off.
6049 * bash also sources ~/.bash_logout on exit.
6050 * If called as sh, skips .bash_XXX files.
6057 * "bash <script>" (which is never interactive (unless -i?))
6058 * sources $BASH_ENV here (without scanning $PATH).
6059 * If called as sh, does the same but with $ENV.
6061 debug_printf("running script '%s'\n", argv[optind]);
6062 G.global_argv = argv + optind;
6063 G.global_argc = argc - optind;
6064 input = xfopen_for_read(argv[optind]);
6065 close_on_exec_on(fileno(input));
6066 if (!signal_mask_is_inited)
6067 block_signals(0); /* 0: called 1st time */
6068 parse_and_run_file(input);
6069 #if ENABLE_FEATURE_CLEAN_UP
6075 /* Up to here, shell was non-interactive. Now it may become one.
6076 * NB: don't forget to (re)run block_signals(0/1) as needed.
6079 /* A shell is interactive if the '-i' flag was given, or if all of
6080 * the following conditions are met:
6082 * no arguments remaining or the -s flag given
6083 * standard input is a terminal
6084 * standard output is a terminal
6085 * Refer to Posix.2, the description of the 'sh' utility.
6088 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6089 G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
6090 debug_printf("saved_tty_pgrp:%d\n", G.saved_tty_pgrp);
6091 //TODO: "interactive" and "have job control" are two different things.
6092 //If tcgetpgrp fails here, "have job control" is false, but "interactive"
6093 //should stay on! Currently, we mix these into one.
6094 if (G.saved_tty_pgrp >= 0) {
6095 /* try to dup stdin to high fd#, >= 255 */
6096 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6097 if (G_interactive_fd < 0) {
6098 /* try to dup to any fd */
6099 G_interactive_fd = dup(STDIN_FILENO);
6100 if (G_interactive_fd < 0)
6102 G_interactive_fd = 0;
6104 // TODO: track & disallow any attempts of user
6105 // to (inadvertently) close/redirect it
6108 debug_printf("interactive_fd:%d\n", G_interactive_fd);
6109 if (G_interactive_fd) {
6112 /* We are indeed interactive shell, and we will perform
6113 * job control. Setting up for that. */
6115 close_on_exec_on(G_interactive_fd);
6116 /* If we were run as 'hush &', sleep until we are
6117 * in the foreground (tty pgrp == our pgrp).
6118 * If we get started under a job aware app (like bash),
6119 * make sure we are now in charge so we don't fight over
6120 * who gets the foreground */
6122 shell_pgrp = getpgrp();
6123 G.saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
6124 if (G.saved_tty_pgrp == shell_pgrp)
6126 /* send TTIN to ourself (should stop us) */
6127 kill(- shell_pgrp, SIGTTIN);
6129 /* Block some signals */
6130 block_signals(signal_mask_is_inited);
6131 /* Set other signals to restore saved_tty_pgrp */
6132 set_fatal_handlers();
6133 /* Put ourselves in our own process group */
6134 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
6135 /* Grab control of the terminal */
6136 tcsetpgrp(G_interactive_fd, getpid());
6137 /* -1 is special - makes xfuncs longjmp, not exit
6138 * (we reset die_sleep = 0 whereever we [v]fork) */
6139 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
6140 } else if (!signal_mask_is_inited) {
6141 block_signals(0); /* 0: called 1st time */
6142 } /* else: block_signals(0) was done before */
6143 #elif ENABLE_HUSH_INTERACTIVE
6144 /* No job control compiled in, only prompt/line editing */
6145 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
6146 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
6147 if (G_interactive_fd < 0) {
6148 /* try to dup to any fd */
6149 G_interactive_fd = dup(STDIN_FILENO);
6150 if (G_interactive_fd < 0)
6152 G_interactive_fd = 0;
6155 if (G_interactive_fd) {
6156 close_on_exec_on(G_interactive_fd);
6157 block_signals(signal_mask_is_inited);
6158 } else if (!signal_mask_is_inited) {
6162 /* We have interactiveness code disabled */
6163 if (!signal_mask_is_inited) {
6168 * if interactive but not a login shell, sources ~/.bashrc
6169 * (--norc turns this off, --rcfile <file> overrides)
6172 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
6173 printf("\n\n%s hush - the humble shell\n", bb_banner);
6174 printf("Enter 'help' for a list of built-in commands.\n\n");
6177 parse_and_run_file(stdin);
6180 #if ENABLE_FEATURE_CLEAN_UP
6181 if (G.cwd != bb_msg_unknown)
6183 cur_var = G.top_var->next;
6185 struct variable *tmp = cur_var;
6186 if (!cur_var->max_len)
6187 free(cur_var->varstr);
6188 cur_var = cur_var->next;
6192 hush_exit(G.last_exitcode);
6197 int lash_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
6198 int lash_main(int argc, char **argv)
6200 //bb_error_msg("lash is deprecated, please use hush instead");
6201 return hush_main(argc, argv);
6209 static int builtin_trap(char **argv)
6216 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
6220 /* No args: print all trapped. This isn't 100% correct as we
6221 * should be escaping the cmd so that it can be pasted back in
6223 for (i = 0; i < NSIG; ++i)
6225 printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
6226 return EXIT_SUCCESS;
6231 /* If first arg is decimal: reset all specified signals */
6232 sig = bb_strtou(*argv, NULL, 10);
6238 sig = get_signum(*argv++);
6239 if (sig < 0 || sig >= NSIG) {
6241 /* Mimic bash message exactly */
6242 bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
6247 G.traps[sig] = xstrdup(new_cmd);
6249 debug_printf("trap: setting SIG%s (%i) to '%s'",
6250 get_signame(sig), sig, G.traps[sig]);
6252 /* There is no signal for 0 (EXIT) */
6257 sigaddset(&G.blocked_set, sig);
6259 /* There was a trap handler, we are removing it
6260 * (if sig has non-DFL handling,
6261 * we don't need to do anything) */
6262 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
6264 sigdelset(&G.blocked_set, sig);
6266 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6271 /* First arg is "-": reset all specified to default */
6272 /* First arg is "": ignore all specified */
6273 /* Everything else: execute first arg upon signal */
6275 bb_error_msg("trap: invalid arguments");
6276 return EXIT_FAILURE;
6278 if (NOT_LONE_DASH(*argv))
6284 static int builtin_true(char **argv UNUSED_PARAM)
6289 static int builtin_test(char **argv)
6296 return test_main(argc, argv - argc);
6299 static int builtin_echo(char **argv)
6306 return echo_main(argc, argv - argc);
6309 static int builtin_eval(char **argv)
6311 int rcode = EXIT_SUCCESS;
6314 char *str = expand_strvec_to_string(argv);
6316 * eval "echo Hi; done" ("done" is syntax error):
6317 * "echo Hi" will not execute too.
6319 parse_and_run_string(str);
6321 rcode = G.last_exitcode;
6326 static int builtin_cd(char **argv)
6328 const char *newdir = argv[1];
6329 if (newdir == NULL) {
6330 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
6331 * bash says "bash: cd: HOME not set" and does nothing
6334 newdir = getenv("HOME") ? : "/";
6336 if (chdir(newdir)) {
6337 /* Mimic bash message exactly */
6338 bb_perror_msg("cd: %s", newdir);
6339 return EXIT_FAILURE;
6342 return EXIT_SUCCESS;
6345 static int builtin_exec(char **argv)
6347 if (*++argv == NULL)
6348 return EXIT_SUCCESS; /* bash does this */
6353 // TODO: if exec fails, bash does NOT exit! We do...
6354 pseudo_exec_argv(&dummy, argv, 0, NULL);
6359 static int builtin_exit(char **argv)
6361 debug_printf_exec("%s()\n", __func__);
6362 // TODO: bash does it ONLY on top-level sh exit (+interacive only?)
6363 //puts("exit"); /* bash does it */
6364 // TODO: warn if we have background jobs: "There are stopped jobs"
6365 // On second consecutive 'exit', exit anyway.
6366 // perhaps use G.exiting = -1 as indicator "last cmd was exit"
6368 /* note: EXIT trap is run by hush_exit */
6369 if (*++argv == NULL)
6370 hush_exit(G.last_exitcode);
6371 /* mimic bash: exit 123abc == exit 255 + error msg */
6372 xfunc_error_retval = 255;
6373 /* bash: exit -2 == exit 254, no error msg */
6374 hush_exit(xatoi(*argv) & 0xff);
6377 static int builtin_export(char **argv)
6379 if (*++argv == NULL) {
6386 /* ash emits: export VAR='VAL'
6387 * bash: declare -x VAR="VAL"
6388 * we follow ash example */
6389 const char *s = *e++;
6390 const char *p = strchr(s, '=');
6392 if (!p) /* wtf? take next variable */
6395 printf("export %.*s", (int)(p - s) + 1, s);
6399 p = strchrnul(s, '\'');
6401 printf("'%.*s'", (int)(p - s), s);
6406 /* s points to '; print ''...'''" */
6408 do putchar('\''); while (*++s == '\'');
6416 return EXIT_SUCCESS;
6423 value = strchr(name, '=');
6425 /* They are exporting something without a =VALUE */
6426 struct variable *var;
6428 var = get_local_var(name);
6430 var->flg_export = 1;
6431 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
6432 putenv(var->varstr);
6434 /* bash does not return an error when trying to export
6435 * an undefined variable. Do likewise. */
6438 set_local_var(xstrdup(name), 1, 0);
6441 return EXIT_SUCCESS;
6445 /* built-in 'fg' and 'bg' handler */
6446 static int builtin_fg_bg(char **argv)
6451 if (!G_interactive_fd)
6452 return EXIT_FAILURE;
6453 /* If they gave us no args, assume they want the last backgrounded task */
6455 for (pi = G.job_list; pi; pi = pi->next) {
6456 if (pi->jobid == G.last_jobid) {
6460 bb_error_msg("%s: no current job", argv[0]);
6461 return EXIT_FAILURE;
6463 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
6464 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
6465 return EXIT_FAILURE;
6467 for (pi = G.job_list; pi; pi = pi->next) {
6468 if (pi->jobid == jobnum) {
6472 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
6473 return EXIT_FAILURE;
6475 // TODO: bash prints a string representation
6476 // of job being foregrounded (like "sleep 1 | cat")
6477 if (argv[0][0] == 'f') {
6478 /* Put the job into the foreground. */
6479 tcsetpgrp(G_interactive_fd, pi->pgrp);
6482 /* Restart the processes in the job */
6483 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
6484 for (i = 0; i < pi->num_cmds; i++) {
6485 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
6486 pi->cmds[i].is_stopped = 0;
6488 pi->stopped_cmds = 0;
6490 i = kill(- pi->pgrp, SIGCONT);
6492 if (errno == ESRCH) {
6493 delete_finished_bg_job(pi);
6494 return EXIT_SUCCESS;
6496 bb_perror_msg("kill (SIGCONT)");
6499 if (argv[0][0] == 'f') {
6501 return checkjobs_and_fg_shell(pi);
6503 return EXIT_SUCCESS;
6507 #if ENABLE_HUSH_HELP
6508 static int builtin_help(char **argv UNUSED_PARAM)
6510 const struct built_in_command *x;
6513 "Built-in commands:\n"
6514 "------------------\n");
6515 for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
6516 printf("%s\t%s\n", x->cmd, x->descr);
6519 return EXIT_SUCCESS;
6524 static int builtin_jobs(char **argv UNUSED_PARAM)
6527 const char *status_string;
6529 for (job = G.job_list; job; job = job->next) {
6530 if (job->alive_cmds == job->stopped_cmds)
6531 status_string = "Stopped";
6533 status_string = "Running";
6535 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
6537 return EXIT_SUCCESS;
6542 static int builtin_memleak(char **argv UNUSED_PARAM)
6547 /* Crude attempt to find where "free memory" starts,
6548 * sans fragmentation. */
6550 l = (unsigned long)p;
6553 if (l < (unsigned long)p) l = (unsigned long)p;
6556 if (!G.memleak_value)
6557 G.memleak_value = l;
6559 l -= G.memleak_value;
6566 /* Exitcode is "how many kilobytes we leaked since 1st call" */
6571 static int builtin_pwd(char **argv UNUSED_PARAM)
6574 return EXIT_SUCCESS;
6577 static int builtin_read(char **argv)
6580 const char *name = "REPLY";
6584 /* bash (3.2.33(1)) bug: "read 0abcd" will execute,
6585 * and _after_ that_ it will complain */
6586 if (!is_well_formed_var_name(name, '\0')) {
6587 /* Mimic bash message */
6588 bb_error_msg("read: '%s': not a valid identifier", name);
6593 //TODO: bash unbackslashes input, splits words and puts them in argv[i]
6595 string = xmalloc_reads(STDIN_FILENO, xasprintf("%s=", name), NULL);
6596 return set_local_var(string, 0, 0);
6599 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
6600 * built-in 'set' handler
6602 * set [-abCefhmnuvx] [-o option] [argument...]
6603 * set [+abCefhmnuvx] [+o option] [argument...]
6604 * set -- [argument...]
6607 * Implementations shall support the options in both their hyphen and
6608 * plus-sign forms. These options can also be specified as options to sh.
6610 * Write out all variables and their values: set
6611 * Set $1, $2, and $3 and set "$#" to 3: set c a b
6612 * Turn on the -x and -v options: set -xv
6613 * Unset all positional parameters: set --
6614 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
6615 * Set the positional parameters to the expansion of x, even if x expands
6616 * with a leading '-' or '+': set -- $x
6618 * So far, we only support "set -- [argument...]" and some of the short names.
6620 static int builtin_set(char **argv)
6623 char **pp, **g_argv;
6624 char *arg = *++argv;
6628 for (e = G.top_var; e; e = e->next)
6630 return EXIT_SUCCESS;
6634 if (!strcmp(arg, "--")) {
6638 if (arg[0] != '+' && arg[0] != '-')
6640 for (n = 1; arg[n]; ++n)
6641 if (set_mode(arg[0], arg[n]))
6643 } while ((arg = *++argv) != NULL);
6644 /* Now argv[0] is 1st argument */
6647 return EXIT_SUCCESS;
6650 /* NB: G.global_argv[0] ($0) is never freed/changed */
6651 g_argv = G.global_argv;
6652 if (G.global_args_malloced) {
6658 G.global_args_malloced = 1;
6659 pp = xzalloc(sizeof(pp[0]) * 2);
6660 pp[0] = g_argv[0]; /* retain $0 */
6663 /* This realloc's G.global_argv */
6664 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
6671 return EXIT_SUCCESS;
6673 /* Nothing known, so abort */
6675 bb_error_msg("set: %s: invalid option", arg);
6676 return EXIT_FAILURE;
6679 static int builtin_shift(char **argv)
6685 if (n >= 0 && n < G.global_argc) {
6686 if (G.global_args_malloced) {
6689 free(G.global_argv[m++]);
6692 memmove(&G.global_argv[1], &G.global_argv[n+1],
6693 G.global_argc * sizeof(G.global_argv[0]));
6694 return EXIT_SUCCESS;
6696 return EXIT_FAILURE;
6699 static int builtin_source(char **argv)
6705 if (*++argv == NULL)
6706 return EXIT_FAILURE;
6708 /* TODO: search through $PATH is missing */
6709 input = fopen_or_warn(*argv, "r");
6711 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
6712 return EXIT_FAILURE;
6714 close_on_exec_on(fileno(input));
6716 sv_flg = G.flag_return_in_progress;
6717 /* "we are inside sourced file, ok to use return" */
6718 G.flag_return_in_progress = -1;
6719 save_and_replace_G_args(&sv, argv);
6721 parse_and_run_file(input);
6724 restore_G_args(&sv, argv);
6725 G.flag_return_in_progress = sv_flg;
6727 return G.last_exitcode;
6730 static int builtin_umask(char **argv)
6733 const char *arg = argv[1];
6735 //TODO: umask may take chmod-like symbolic masks
6736 new_umask = bb_strtou(arg, NULL, 8);
6738 //Message? bash examples:
6739 //bash: umask: 'q': invalid symbolic mode operator
6740 //bash: umask: 999: octal number out of range
6741 return EXIT_FAILURE;
6744 new_umask = umask(0);
6745 printf("%.3o\n", (unsigned) new_umask);
6746 /* fall through and restore new_umask which we set to 0 */
6749 return EXIT_SUCCESS;
6752 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
6753 static int builtin_unset(char **argv)
6759 return EXIT_SUCCESS;
6762 if (argv[0][0] == '-') {
6763 switch (argv[0][1]) {
6769 bb_error_msg("unset: %s: invalid option", *argv);
6770 return EXIT_FAILURE;
6772 //TODO: disallow "unset -vf ..." too
6779 if (unset_local_var(*argv)) {
6780 /* unset <nonexistent_var> doesn't fail.
6781 * Error is when one tries to unset RO var.
6782 * Message was printed by unset_local_var. */
6786 //#if ENABLE_HUSH_FUNCTIONS
6788 // unset_local_func(*argv);
6796 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
6797 static int builtin_wait(char **argv)
6799 int ret = EXIT_SUCCESS;
6802 if (*++argv == NULL) {
6803 /* Don't care about wait results */
6804 /* Note 1: must wait until there are no more children */
6805 /* Note 2: must be interruptible */
6807 * $ sleep 3 & sleep 6 & wait
6812 * $ sleep 3 & sleep 6 & wait
6816 * ^C <-- after ~4 sec from keyboard
6819 sigaddset(&G.blocked_set, SIGCHLD);
6820 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6823 if (errno == ECHILD)
6825 /* Wait for SIGCHLD or any other signal of interest */
6826 /* sigtimedwait with infinite timeout: */
6827 sig = sigwaitinfo(&G.blocked_set, NULL);
6829 sig = check_and_run_traps(sig);
6830 if (sig && sig != SIGCHLD) { /* see note 2 */
6836 sigdelset(&G.blocked_set, SIGCHLD);
6837 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
6841 /* This is probably buggy wrt interruptible-ness */
6843 pid_t pid = bb_strtou(*argv, NULL, 10);
6845 /* mimic bash message */
6846 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
6847 return EXIT_FAILURE;
6849 if (waitpid(pid, &status, 0) == pid) {
6850 if (WIFSIGNALED(status))
6851 ret = 128 + WTERMSIG(status);
6852 else if (WIFEXITED(status))
6853 ret = WEXITSTATUS(status);
6857 bb_perror_msg("wait %s", *argv);
6866 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
6867 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
6870 def = bb_strtou(argv[1], NULL, 10);
6871 if (errno || def < def_min || argv[2]) {
6872 bb_error_msg("%s: bad arguments", argv[0]);
6880 #if ENABLE_HUSH_LOOPS
6881 static int builtin_break(char **argv)
6884 if (G.depth_of_loop == 0) {
6885 bb_error_msg("%s: only meaningful in a loop", argv[0]);
6886 return EXIT_SUCCESS; /* bash compat */
6888 G.flag_break_continue++; /* BC_BREAK = 1 */
6890 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
6891 if (depth == UINT_MAX)
6892 G.flag_break_continue = BC_BREAK;
6893 if (G.depth_of_loop < depth)
6894 G.depth_break_continue = G.depth_of_loop;
6896 return EXIT_SUCCESS;
6899 static int builtin_continue(char **argv)
6901 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
6902 return builtin_break(argv);
6906 #if ENABLE_HUSH_FUNCTIONS
6907 static int builtin_return(char **argv UNUSED_PARAM)
6911 if (G.flag_return_in_progress != -1) {
6912 bb_error_msg("%s: not in a function or sourced script", argv[0]);
6913 return EXIT_FAILURE; /* bash compat */
6916 G.flag_return_in_progress = 1;
6919 * out of range: wraps around at 256, does not error out
6920 * non-numeric param:
6921 * f() { false; return qwe; }; f; echo $?
6922 * bash: return: qwe: numeric argument required <== we do this
6923 * 255 <== we also do this
6925 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);