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>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
84 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
85 || defined(__APPLE__) \
87 # include <malloc.h> /* for malloc_trim */
90 /* #include <dmalloc.h> */
95 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
97 #include "shell_common.h"
100 #if ENABLE_HUSH_RANDOM_SUPPORT
103 # define CLEAR_RANDOM_T(rnd) ((void)0)
106 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
110 //config: bool "hush"
113 //config: hush is a small shell (25k). It handles the normal flow control
114 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
115 //config: case/esac. Redirections, here documents, $((arithmetic))
116 //config: and functions are supported.
118 //config: It will compile and work on no-mmu systems.
120 //config: It does not handle select, aliases, tilde expansion,
121 //config: &>file and >&file redirection of stdout+stderr.
123 //config:config HUSH_BASH_COMPAT
124 //config: bool "bash-compatible extensions"
126 //config: depends on HUSH
128 //config: Enable bash-compatible extensions.
130 //config:config HUSH_BRACE_EXPANSION
131 //config: bool "Brace expansion"
133 //config: depends on HUSH_BASH_COMPAT
135 //config: Enable {abc,def} extension.
137 //config:config HUSH_HELP
138 //config: bool "help builtin"
140 //config: depends on HUSH
142 //config: Enable help builtin in hush. Code size + ~1 kbyte.
144 //config:config HUSH_INTERACTIVE
145 //config: bool "Interactive mode"
147 //config: depends on HUSH
149 //config: Enable interactive mode (prompt and command editing).
150 //config: Without this, hush simply reads and executes commands
151 //config: from stdin just like a shell script from a file.
152 //config: No prompt, no PS1/PS2 magic shell variables.
154 //config:config HUSH_SAVEHISTORY
155 //config: bool "Save command history to .hush_history"
157 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
159 //config: Enable history saving in hush.
161 //config:config HUSH_JOB
162 //config: bool "Job control"
164 //config: depends on HUSH_INTERACTIVE
166 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
167 //config: command (not entire shell), fg/bg builtins work. Without this option,
168 //config: "cmd &" still works by simply spawning a process and immediately
169 //config: prompting for next command (or executing next command in a script),
170 //config: but no separate process group is formed.
172 //config:config HUSH_TICK
173 //config: bool "Process substitution"
175 //config: depends on HUSH
177 //config: Enable process substitution `command` and $(command) in hush.
179 //config:config HUSH_IF
180 //config: bool "Support if/then/elif/else/fi"
182 //config: depends on HUSH
184 //config: Enable if/then/elif/else/fi in hush.
186 //config:config HUSH_LOOPS
187 //config: bool "Support for, while and until loops"
189 //config: depends on HUSH
191 //config: Enable for, while and until loops in hush.
193 //config:config HUSH_CASE
194 //config: bool "Support case ... esac statement"
196 //config: depends on HUSH
198 //config: Enable case ... esac statement in hush. +400 bytes.
200 //config:config HUSH_FUNCTIONS
201 //config: bool "Support funcname() { commands; } syntax"
203 //config: depends on HUSH
205 //config: Enable support for shell functions in hush. +800 bytes.
207 //config:config HUSH_LOCAL
208 //config: bool "Support local builtin"
210 //config: depends on HUSH_FUNCTIONS
212 //config: Enable support for local variables in functions.
214 //config:config HUSH_RANDOM_SUPPORT
215 //config: bool "Pseudorandom generator and $RANDOM variable"
217 //config: depends on HUSH
219 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
220 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
222 //config:config HUSH_EXPORT_N
223 //config: bool "Support 'export -n' option"
225 //config: depends on HUSH
227 //config: export -n unexports variables. It is a bash extension.
229 //config:config HUSH_MODE_X
230 //config: bool "Support 'hush -x' option and 'set -x' command"
232 //config: depends on HUSH
234 //config: This instructs hush to print commands before execution.
235 //config: Adds ~300 bytes.
238 //config: bool "msh (deprecated: aliased to hush)"
240 //config: select HUSH
242 //config: msh is deprecated and will be removed, please migrate to hush.
245 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
246 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
247 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
248 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
250 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
251 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
253 /* -i (interactive) and -s (read stdin) are also accepted,
254 * but currently do nothing, therefore aren't shown in help.
255 * NOMMU-specific options are not meant to be used by users,
256 * therefore we don't show them either.
258 //usage:#define hush_trivial_usage
259 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
260 //usage:#define hush_full_usage "\n\n"
261 //usage: "Unix shell interpreter"
263 //usage:#define msh_trivial_usage hush_trivial_usage
264 //usage:#define msh_full_usage hush_full_usage
266 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
267 //usage:# define sh_trivial_usage hush_trivial_usage
268 //usage:# define sh_full_usage hush_full_usage
270 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
271 //usage:# define bash_trivial_usage hush_trivial_usage
272 //usage:# define bash_full_usage hush_full_usage
277 #define LEAK_HUNTING 0
278 #define BUILD_AS_NOMMU 0
279 /* Enable/disable sanity checks. Ok to enable in production,
280 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
281 * Keeping 1 for now even in released versions.
284 /* Slightly bigger (+200 bytes), but faster hush.
285 * So far it only enables a trick with counting SIGCHLDs and forks,
286 * which allows us to do fewer waitpid's.
287 * (we can detect a case where neither forks were done nor SIGCHLDs happened
288 * and therefore waitpid will return the same result as last time)
290 #define ENABLE_HUSH_FAST 0
291 /* TODO: implement simplified code for users which do not need ${var%...} ops
292 * So far ${var%...} ops are always enabled:
294 #define ENABLE_HUSH_DOLLAR_OPS 1
299 # undef USE_FOR_NOMMU
302 # define USE_FOR_NOMMU(...) __VA_ARGS__
303 # define USE_FOR_MMU(...)
306 #include "NUM_APPLETS.h"
308 /* STANDALONE does not make sense, and won't compile */
309 # undef CONFIG_FEATURE_SH_STANDALONE
310 # undef ENABLE_FEATURE_SH_STANDALONE
311 # undef IF_FEATURE_SH_STANDALONE
312 # undef IF_NOT_FEATURE_SH_STANDALONE
313 # define ENABLE_FEATURE_SH_STANDALONE 0
314 # define IF_FEATURE_SH_STANDALONE(...)
315 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
318 #if !ENABLE_HUSH_INTERACTIVE
319 # undef ENABLE_FEATURE_EDITING
320 # define ENABLE_FEATURE_EDITING 0
321 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
322 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
323 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
324 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
327 /* Do we support ANY keywords? */
328 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
329 # define HAS_KEYWORDS 1
330 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
331 # define IF_HAS_NO_KEYWORDS(...)
333 # define HAS_KEYWORDS 0
334 # define IF_HAS_KEYWORDS(...)
335 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
338 /* If you comment out one of these below, it will be #defined later
339 * to perform debug printfs to stderr: */
340 #define debug_printf(...) do {} while (0)
341 /* Finer-grained debug switches */
342 #define debug_printf_parse(...) do {} while (0)
343 #define debug_print_tree(a, b) do {} while (0)
344 #define debug_printf_exec(...) do {} while (0)
345 #define debug_printf_env(...) do {} while (0)
346 #define debug_printf_jobs(...) do {} while (0)
347 #define debug_printf_expand(...) do {} while (0)
348 #define debug_printf_varexp(...) do {} while (0)
349 #define debug_printf_glob(...) do {} while (0)
350 #define debug_printf_list(...) do {} while (0)
351 #define debug_printf_subst(...) do {} while (0)
352 #define debug_printf_clean(...) do {} while (0)
354 #define ERR_PTR ((void*)(long)1)
356 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
358 #define _SPECIAL_VARS_STR "_*@$!?#"
359 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
360 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
361 #if ENABLE_HUSH_BASH_COMPAT
362 /* Support / and // replace ops */
363 /* Note that // is stored as \ in "encoded" string representation */
364 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
365 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
366 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
368 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
369 # define VAR_SUBST_OPS "%#:-=+?"
370 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
373 #define SPECIAL_VAR_SYMBOL 3
377 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
379 /* This supports saving pointers malloced in vfork child,
380 * to be freed in the parent.
383 typedef struct nommu_save_t {
385 struct variable *old_vars;
387 char **argv_from_re_execing;
400 #if ENABLE_HUSH_LOOPS
407 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
412 /* three pseudo-keywords support contrived "case" syntax: */
413 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
414 RES_MATCH , /* "word)" */
415 RES_CASE_BODY, /* "this command is inside CASE" */
422 typedef struct o_string {
424 int length; /* position where data is appended */
427 /* At least some part of the string was inside '' or "",
428 * possibly empty one: word"", wo''rd etc. */
429 smallint has_quoted_part;
430 smallint has_empty_slot;
431 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
434 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
436 /* Protect newly added chars against globbing
437 * by prepending \ to *, ?, [, \ */
438 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
441 MAYBE_ASSIGNMENT = 0,
442 DEFINITELY_ASSIGNMENT = 1,
444 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
447 /* Used for initialization: o_string foo = NULL_O_STRING; */
448 #define NULL_O_STRING { NULL }
450 #ifndef debug_printf_parse
451 static const char *const assignment_flag[] = {
453 "DEFINITELY_ASSIGNMENT",
459 typedef struct in_str {
461 /* eof_flag=1: last char in ->p is really an EOF */
462 char eof_flag; /* meaningless if ->p == NULL */
464 #if ENABLE_HUSH_INTERACTIVE
465 smallint promptmode; /* 0: PS1, 1: PS2 */
469 int (*get) (struct in_str *) FAST_FUNC;
470 int (*peek) (struct in_str *) FAST_FUNC;
472 #define i_getch(input) ((input)->get(input))
473 #define i_peek(input) ((input)->peek(input))
475 /* The descrip member of this structure is only used to make
476 * debugging output pretty */
477 static const struct {
479 signed char default_fd;
482 { O_RDONLY, 0, "<" },
483 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
484 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
485 { O_CREAT|O_RDWR, 1, "<>" },
486 { O_RDONLY, 0, "<<" },
487 /* Should not be needed. Bogus default_fd helps in debugging */
488 /* { O_RDONLY, 77, "<<" }, */
491 struct redir_struct {
492 struct redir_struct *next;
493 char *rd_filename; /* filename */
494 int rd_fd; /* fd to redirect */
495 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
497 smallint rd_type; /* (enum redir_type) */
498 /* note: for heredocs, rd_filename contains heredoc delimiter,
499 * and subsequently heredoc itself; and rd_dup is a bitmask:
500 * bit 0: do we need to trim leading tabs?
501 * bit 1: is heredoc quoted (<<'delim' syntax) ?
504 typedef enum redir_type {
506 REDIRECT_OVERWRITE = 1,
509 REDIRECT_HEREDOC = 4,
510 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
513 REDIRFD_SYNTAX_ERR = -2,
514 REDIRFD_TO_FILE = -1,
515 /* otherwise, rd_fd is redirected to rd_dup */
517 HEREDOC_SKIPTABS = 1,
523 pid_t pid; /* 0 if exited */
524 int assignment_cnt; /* how many argv[i] are assignments? */
525 smallint cmd_type; /* CMD_xxx */
527 #define CMD_SUBSHELL 1
528 #if ENABLE_HUSH_BASH_COMPAT
529 /* used for "[[ EXPR ]]" */
530 # define CMD_SINGLEWORD_NOGLOB 2
532 #if ENABLE_HUSH_FUNCTIONS
533 # define CMD_FUNCDEF 3
536 smalluint cmd_exitcode;
537 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
540 char *group_as_string;
542 #if ENABLE_HUSH_FUNCTIONS
543 struct function *child_func;
544 /* This field is used to prevent a bug here:
545 * while...do f1() {a;}; f1; f1() {b;}; f1; done
546 * When we execute "f1() {a;}" cmd, we create new function and clear
547 * cmd->group, cmd->group_as_string, cmd->argv[0].
548 * When we execute "f1() {b;}", we notice that f1 exists,
549 * and that its "parent cmd" struct is still "alive",
550 * we put those fields back into cmd->xxx
551 * (struct function has ->parent_cmd ptr to facilitate that).
552 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
553 * Without this trick, loop would execute a;b;b;b;...
554 * instead of correct sequence a;b;a;b;...
555 * When command is freed, it severs the link
556 * (sets ->child_func->parent_cmd to NULL).
559 char **argv; /* command name and arguments */
560 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
561 * and on execution these are substituted with their values.
562 * Substitution can make _several_ words out of one argv[n]!
563 * Example: argv[0]=='.^C*^C.' here: echo .$*.
564 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
566 struct redir_struct *redirects; /* I/O redirections */
568 /* Is there anything in this command at all? */
569 #define IS_NULL_CMD(cmd) \
570 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
574 int num_cmds; /* total number of commands in pipe */
575 int alive_cmds; /* number of commands running (not exited) */
576 int stopped_cmds; /* number of commands alive, but stopped */
578 int jobid; /* job number */
579 pid_t pgrp; /* process group ID for the job */
580 char *cmdtext; /* name of job */
582 struct command *cmds; /* array of commands in pipe */
583 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
584 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
585 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
587 typedef enum pipe_style {
593 /* Is there anything in this pipe at all? */
594 #define IS_NULL_PIPE(pi) \
595 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
597 /* This holds pointers to the various results of parsing */
598 struct parse_context {
599 /* linked list of pipes */
600 struct pipe *list_head;
601 /* last pipe (being constructed right now) */
603 /* last command in pipe (being constructed right now) */
604 struct command *command;
605 /* last redirect in command->redirects list */
606 struct redir_struct *pending_redirect;
612 smallint ctx_inverted; /* "! cmd | cmd" */
614 smallint ctx_dsemicolon; /* ";;" seen */
616 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
618 /* group we are enclosed in:
619 * example: "if pipe1; pipe2; then pipe3; fi"
620 * when we see "if" or "then", we malloc and copy current context,
621 * and make ->stack point to it. then we parse pipeN.
622 * when closing "then" / fi" / whatever is found,
623 * we move list_head into ->stack->command->group,
624 * copy ->stack into current context, and delete ->stack.
625 * (parsing of { list } and ( list ) doesn't use this method)
627 struct parse_context *stack;
631 /* On program start, environ points to initial environment.
632 * putenv adds new pointers into it, unsetenv removes them.
633 * Neither of these (de)allocates the strings.
634 * setenv allocates new strings in malloc space and does putenv,
635 * and thus setenv is unusable (leaky) for shell's purposes */
636 #define setenv(...) setenv_is_leaky_dont_use()
638 struct variable *next;
639 char *varstr; /* points to "name=" portion */
640 #if ENABLE_HUSH_LOCAL
641 unsigned func_nest_level;
643 int max_len; /* if > 0, name is part of initial env; else name is malloced */
644 smallint flg_export; /* putenv should be done on this var */
645 smallint flg_read_only;
653 #if ENABLE_HUSH_FUNCTIONS
655 struct function *next;
657 struct command *parent_cmd;
660 char *body_as_string;
666 /* set -/+o OPT support. (TODO: make it optional)
667 * bash supports the following opts:
678 * interactive-comments on
696 static const char o_opt_strings[] ALIGN1 =
699 #if ENABLE_HUSH_MODE_X
706 #if ENABLE_HUSH_MODE_X
713 /* "Globals" within this file */
714 /* Sorted roughly by size (smaller offsets == smaller code) */
716 /* interactive_fd != 0 means we are an interactive shell.
717 * If we are, then saved_tty_pgrp can also be != 0, meaning
718 * that controlling tty is available. With saved_tty_pgrp == 0,
719 * job control still works, but terminal signals
720 * (^C, ^Z, ^Y, ^\) won't work at all, and background
721 * process groups can only be created with "cmd &".
722 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
723 * to give tty to the foreground process group,
724 * and will take it back when the group is stopped (^Z)
727 #if ENABLE_HUSH_INTERACTIVE
728 /* 'interactive_fd' is a fd# open to ctty, if we have one
729 * _AND_ if we decided to act interactively */
733 # define G_interactive_fd (G.interactive_fd)
735 # define G_interactive_fd 0
737 #if ENABLE_FEATURE_EDITING
738 line_input_t *line_input_state;
743 #if ENABLE_HUSH_RANDOM_SUPPORT
749 pid_t saved_tty_pgrp;
750 struct pipe *job_list;
751 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
753 # define G_saved_tty_pgrp 0
755 char o_opt[NUM_OPT_O];
756 #if ENABLE_HUSH_MODE_X
757 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
761 smallint flag_SIGINT;
762 #if ENABLE_HUSH_LOOPS
763 smallint flag_break_continue;
765 #if ENABLE_HUSH_FUNCTIONS
766 /* 0: outside of a function (or sourced file)
767 * -1: inside of a function, ok to use return builtin
768 * 1: return is invoked, skip all till end of func
770 smallint flag_return_in_progress;
772 smallint exiting; /* used to prevent EXIT trap recursion */
773 /* These four support $?, $#, and $1 */
774 smalluint last_exitcode;
775 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
776 smalluint global_args_malloced;
777 /* how many non-NULL argv's we have. NB: $# + 1 */
781 char *argv0_for_re_execing;
783 #if ENABLE_HUSH_LOOPS
784 unsigned depth_break_continue;
785 unsigned depth_of_loop;
789 struct variable *top_var;
790 char **expanded_assignments;
791 #if ENABLE_HUSH_FUNCTIONS
792 struct function *top_func;
793 # if ENABLE_HUSH_LOCAL
794 struct variable **shadowed_vars_pp;
795 unsigned func_nest_level;
798 /* Signal and trap handling */
800 unsigned count_SIGCHLD;
801 unsigned handled_SIGCHLD;
802 smallint we_have_children;
804 /* Which signals have non-DFL handler (even with no traps set)?
805 * Set at the start to:
806 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
807 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
808 * The rest is cleared right before execv syscalls.
809 * Other than these two times, never modified.
811 unsigned special_sig_mask;
813 unsigned fatal_sig_mask;
814 # define G_fatal_sig_mask G.fatal_sig_mask
816 # define G_fatal_sig_mask 0
818 char **traps; /* char *traps[NSIG] */
819 sigset_t pending_set;
821 unsigned long memleak_value;
825 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
827 #define G (*ptr_to_globals)
828 /* Not #defining name to G.name - this quickly gets unwieldy
829 * (too many defines). Also, I actually prefer to see when a variable
830 * is global, thus "G." prefix is a useful hint */
831 #define INIT_G() do { \
832 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
833 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
834 sigfillset(&G.sa.sa_mask); \
835 G.sa.sa_flags = SA_RESTART; \
839 /* Function prototypes for builtins */
840 static int builtin_cd(char **argv) FAST_FUNC;
841 static int builtin_echo(char **argv) FAST_FUNC;
842 static int builtin_eval(char **argv) FAST_FUNC;
843 static int builtin_exec(char **argv) FAST_FUNC;
844 static int builtin_exit(char **argv) FAST_FUNC;
845 static int builtin_export(char **argv) FAST_FUNC;
847 static int builtin_fg_bg(char **argv) FAST_FUNC;
848 static int builtin_jobs(char **argv) FAST_FUNC;
851 static int builtin_help(char **argv) FAST_FUNC;
853 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
854 static int builtin_history(char **argv) FAST_FUNC;
856 #if ENABLE_HUSH_LOCAL
857 static int builtin_local(char **argv) FAST_FUNC;
860 static int builtin_memleak(char **argv) FAST_FUNC;
863 static int builtin_printf(char **argv) FAST_FUNC;
865 static int builtin_pwd(char **argv) FAST_FUNC;
866 static int builtin_read(char **argv) FAST_FUNC;
867 static int builtin_set(char **argv) FAST_FUNC;
868 static int builtin_shift(char **argv) FAST_FUNC;
869 static int builtin_source(char **argv) FAST_FUNC;
870 static int builtin_test(char **argv) FAST_FUNC;
871 static int builtin_trap(char **argv) FAST_FUNC;
872 static int builtin_type(char **argv) FAST_FUNC;
873 static int builtin_true(char **argv) FAST_FUNC;
874 static int builtin_umask(char **argv) FAST_FUNC;
875 static int builtin_unset(char **argv) FAST_FUNC;
876 static int builtin_wait(char **argv) FAST_FUNC;
877 #if ENABLE_HUSH_LOOPS
878 static int builtin_break(char **argv) FAST_FUNC;
879 static int builtin_continue(char **argv) FAST_FUNC;
881 #if ENABLE_HUSH_FUNCTIONS
882 static int builtin_return(char **argv) FAST_FUNC;
885 /* Table of built-in functions. They can be forked or not, depending on
886 * context: within pipes, they fork. As simple commands, they do not.
887 * When used in non-forking context, they can change global variables
888 * in the parent shell process. If forked, of course they cannot.
889 * For example, 'unset foo | whatever' will parse and run, but foo will
890 * still be set at the end. */
891 struct built_in_command {
893 int (*b_function)(char **argv) FAST_FUNC;
896 # define BLTIN(cmd, func, help) { cmd, func, help }
898 # define BLTIN(cmd, func, help) { cmd, func }
902 static const struct built_in_command bltins1[] = {
903 BLTIN("." , builtin_source , "Run commands in a file"),
904 BLTIN(":" , builtin_true , NULL),
906 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
908 #if ENABLE_HUSH_LOOPS
909 BLTIN("break" , builtin_break , "Exit from a loop"),
911 BLTIN("cd" , builtin_cd , "Change directory"),
912 #if ENABLE_HUSH_LOOPS
913 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
915 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
916 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
917 BLTIN("exit" , builtin_exit , "Exit"),
918 BLTIN("export" , builtin_export , "Set environment variables"),
920 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
923 BLTIN("help" , builtin_help , NULL),
925 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
926 BLTIN("history" , builtin_history , "Show command history"),
929 BLTIN("jobs" , builtin_jobs , "List jobs"),
931 #if ENABLE_HUSH_LOCAL
932 BLTIN("local" , builtin_local , "Set local variables"),
935 BLTIN("memleak" , builtin_memleak , NULL),
937 BLTIN("read" , builtin_read , "Input into variable"),
938 #if ENABLE_HUSH_FUNCTIONS
939 BLTIN("return" , builtin_return , "Return from a function"),
941 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
942 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
943 #if ENABLE_HUSH_BASH_COMPAT
944 BLTIN("source" , builtin_source , "Run commands in a file"),
946 BLTIN("trap" , builtin_trap , "Trap signals"),
947 BLTIN("type" , builtin_type , "Show command type"),
948 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
949 BLTIN("umask" , builtin_umask , "Set file creation mask"),
950 BLTIN("unset" , builtin_unset , "Unset variables"),
951 BLTIN("wait" , builtin_wait , "Wait for process"),
953 /* For now, echo and test are unconditionally enabled.
954 * Maybe make it configurable? */
955 static const struct built_in_command bltins2[] = {
956 BLTIN("[" , builtin_test , NULL),
957 BLTIN("echo" , builtin_echo , NULL),
959 BLTIN("printf" , builtin_printf , NULL),
961 BLTIN("pwd" , builtin_pwd , NULL),
962 BLTIN("test" , builtin_test , NULL),
969 /* prevent disasters with G.debug_indent < 0 */
970 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
971 # define debug_enter() (G.debug_indent++)
972 # define debug_leave() (G.debug_indent--)
974 # define indent() ((void)0)
975 # define debug_enter() ((void)0)
976 # define debug_leave() ((void)0)
980 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
983 #ifndef debug_printf_parse
984 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
987 #ifndef debug_printf_exec
988 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
991 #ifndef debug_printf_env
992 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
995 #ifndef debug_printf_jobs
996 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
997 # define DEBUG_JOBS 1
999 # define DEBUG_JOBS 0
1002 #ifndef debug_printf_expand
1003 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1004 # define DEBUG_EXPAND 1
1006 # define DEBUG_EXPAND 0
1009 #ifndef debug_printf_varexp
1010 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1013 #ifndef debug_printf_glob
1014 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1015 # define DEBUG_GLOB 1
1017 # define DEBUG_GLOB 0
1020 #ifndef debug_printf_list
1021 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1024 #ifndef debug_printf_subst
1025 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1028 #ifndef debug_printf_clean
1029 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1030 # define DEBUG_CLEAN 1
1032 # define DEBUG_CLEAN 0
1036 static void debug_print_strings(const char *prefix, char **vv)
1039 fdprintf(2, "%s:\n", prefix);
1041 fdprintf(2, " '%s'\n", *vv++);
1044 # define debug_print_strings(prefix, vv) ((void)0)
1048 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1051 static void *xxmalloc(int lineno, size_t size)
1053 void *ptr = xmalloc((size + 0xff) & ~0xff);
1054 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1057 static void *xxrealloc(int lineno, void *ptr, size_t size)
1059 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1060 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1063 static char *xxstrdup(int lineno, const char *str)
1065 char *ptr = xstrdup(str);
1066 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1069 static void xxfree(void *ptr)
1071 fdprintf(2, "free %p\n", ptr);
1074 # define xmalloc(s) xxmalloc(__LINE__, s)
1075 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1076 # define xstrdup(s) xxstrdup(__LINE__, s)
1077 # define free(p) xxfree(p)
1081 /* Syntax and runtime errors. They always abort scripts.
1082 * In interactive use they usually discard unparsed and/or unexecuted commands
1083 * and return to the prompt.
1084 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1087 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1088 # define syntax_error(lineno, msg) syntax_error(msg)
1089 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1090 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1091 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1092 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1095 static void die_if_script(unsigned lineno, const char *fmt, ...)
1100 bb_error_msg("hush.c:%u", lineno);
1103 bb_verror_msg(fmt, p, NULL);
1105 if (!G_interactive_fd)
1109 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1112 bb_error_msg("syntax error: %s", msg);
1114 bb_error_msg("syntax error");
1117 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1119 bb_error_msg("syntax error at '%s'", msg);
1122 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1124 bb_error_msg("syntax error: unterminated %s", s);
1127 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1129 char msg[2] = { ch, '\0' };
1130 syntax_error_unterm_str(lineno, msg);
1133 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1138 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1142 # undef die_if_script
1143 # undef syntax_error
1144 # undef syntax_error_at
1145 # undef syntax_error_unterm_ch
1146 # undef syntax_error_unterm_str
1147 # undef syntax_error_unexpected_ch
1149 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1150 # define syntax_error(msg) syntax_error(__LINE__, msg)
1151 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1152 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1153 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1154 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1158 #if ENABLE_HUSH_INTERACTIVE
1159 static void cmdedit_update_prompt(void);
1161 # define cmdedit_update_prompt() ((void)0)
1165 /* Utility functions
1167 /* Replace each \x with x in place, return ptr past NUL. */
1168 static char *unbackslash(char *src)
1170 char *dst = src = strchrnul(src, '\\');
1174 if ((*dst++ = *src++) == '\0')
1180 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1201 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1202 v[count1 + count2] = NULL;
1205 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1209 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1211 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1212 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1215 #define add_strings_to_strings(strings, add, need_to_dup) \
1216 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1219 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1220 static char **add_string_to_strings(char **strings, char *add)
1225 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1228 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1230 char **ptr = add_string_to_strings(strings, add);
1231 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1234 #define add_string_to_strings(strings, add) \
1235 xx_add_string_to_strings(__LINE__, strings, add)
1238 static void free_strings(char **strings)
1253 /* Helpers for setting new $n and restoring them back
1255 typedef struct save_arg_t {
1259 smallint sv_g_malloced;
1262 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1266 sv->sv_argv0 = argv[0];
1267 sv->sv_g_argv = G.global_argv;
1268 sv->sv_g_argc = G.global_argc;
1269 sv->sv_g_malloced = G.global_args_malloced;
1271 argv[0] = G.global_argv[0]; /* retain $0 */
1272 G.global_argv = argv;
1273 G.global_args_malloced = 0;
1281 static void restore_G_args(save_arg_t *sv, char **argv)
1285 if (G.global_args_malloced) {
1286 /* someone ran "set -- arg1 arg2 ...", undo */
1288 while (*++pp) /* note: does not free $0 */
1290 free(G.global_argv);
1292 argv[0] = sv->sv_argv0;
1293 G.global_argv = sv->sv_g_argv;
1294 G.global_argc = sv->sv_g_argc;
1295 G.global_args_malloced = sv->sv_g_malloced;
1299 /* Basic theory of signal handling in shell
1300 * ========================================
1301 * This does not describe what hush does, rather, it is current understanding
1302 * what it _should_ do. If it doesn't, it's a bug.
1303 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1305 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1306 * is finished or backgrounded. It is the same in interactive and
1307 * non-interactive shells, and is the same regardless of whether
1308 * a user trap handler is installed or a shell special one is in effect.
1309 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1310 * backgrounds (i.e. stops) or kills all members of currently running
1313 * Wait builtin in interruptible by signals for which user trap is set
1314 * or by SIGINT in interactive shell.
1316 * Trap handlers will execute even within trap handlers. (right?)
1318 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1319 * except for handlers set to '' (empty string).
1321 * If job control is off, backgrounded commands ("cmd &")
1322 * have SIGINT, SIGQUIT set to SIG_IGN.
1324 * Commands which are run in command substitution ("`cmd`")
1325 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1327 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1328 * by the shell from its parent.
1330 * Signals which differ from SIG_DFL action
1331 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1334 * SIGTERM (interactive): ignore
1335 * SIGHUP (interactive):
1336 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1337 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1338 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1339 * that all pipe members are stopped. Try this in bash:
1340 * while :; do :; done - ^Z does not background it
1341 * (while :; do :; done) - ^Z backgrounds it
1342 * SIGINT (interactive): wait for last pipe, ignore the rest
1343 * of the command line, show prompt. NB: ^C does not send SIGINT
1344 * to interactive shell while shell is waiting for a pipe,
1345 * since shell is bg'ed (is not in foreground process group).
1346 * Example 1: this waits 5 sec, but does not execute ls:
1347 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1348 * Example 2: this does not wait and does not execute ls:
1349 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1350 * Example 3: this does not wait 5 sec, but executes ls:
1351 * "sleep 5; ls -l" + press ^C
1352 * Example 4: this does not wait and does not execute ls:
1353 * "sleep 5 & wait; ls -l" + press ^C
1355 * (What happens to signals which are IGN on shell start?)
1356 * (What happens with signal mask on shell start?)
1358 * Old implementation
1359 * ==================
1360 * We use in-kernel pending signal mask to determine which signals were sent.
1361 * We block all signals which we don't want to take action immediately,
1362 * i.e. we block all signals which need to have special handling as described
1363 * above, and all signals which have traps set.
1364 * After each pipe execution, we extract any pending signals via sigtimedwait()
1367 * unsigned special_sig_mask: a mask of such "special" signals
1368 * sigset_t blocked_set: current blocked signal set
1371 * clear bit in blocked_set unless it is also in special_sig_mask
1372 * "trap 'cmd' SIGxxx":
1373 * set bit in blocked_set (even if 'cmd' is '')
1374 * after [v]fork, if we plan to be a shell:
1375 * unblock signals with special interactive handling
1376 * (child shell is not interactive),
1377 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1378 * after [v]fork, if we plan to exec:
1379 * POSIX says fork clears pending signal mask in child - no need to clear it.
1380 * Restore blocked signal set to one inherited by shell just prior to exec.
1382 * Note: as a result, we do not use signal handlers much. The only uses
1383 * are to count SIGCHLDs
1384 * and to restore tty pgrp on signal-induced exit.
1387 * Standard says "When a subshell is entered, traps that are not being ignored
1388 * are set to the default actions". bash interprets it so that traps which
1389 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1391 * Problem: the above approach makes it unwieldy to catch signals while
1392 * we are in read builtin, of while we read commands from stdin:
1393 * masked signals are not visible!
1395 * New implementation
1396 * ==================
1397 * We record each signal we are interested in by installing signal handler
1398 * for them - a bit like emulating kernel pending signal mask in userspace.
1399 * We are interested in: signals which need to have special handling
1400 * as described above, and all signals which have traps set.
1401 * Signals are rocorded in pending_set.
1402 * After each pipe execution, we extract any pending signals
1405 * unsigned special_sig_mask: a mask of shell-special signals.
1406 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1407 * char *traps[sig] if trap for sig is set (even if it's '').
1408 * sigset_t pending_set: set of sigs we received.
1411 * if sig is in special_sig_mask, set handler back to:
1412 * record_pending_signo, or to IGN if it's a tty stop signal
1413 * if sig is in fatal_sig_mask, set handler back to sigexit.
1414 * else: set handler back to SIG_DFL
1415 * "trap 'cmd' SIGxxx":
1416 * set handler to record_pending_signo.
1418 * set handler to SIG_IGN.
1419 * after [v]fork, if we plan to be a shell:
1420 * set signals with special interactive handling to SIG_DFL
1421 * (because child shell is not interactive),
1422 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1423 * after [v]fork, if we plan to exec:
1424 * POSIX says fork clears pending signal mask in child - no need to clear it.
1426 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1427 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1430 * Standard says "When a subshell is entered, traps that are not being ignored
1431 * are set to the default actions". bash interprets it so that traps which
1432 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1435 SPECIAL_INTERACTIVE_SIGS = 0
1440 SPECIAL_JOBSTOP_SIGS = 0
1449 static void record_pending_signo(int sig)
1451 sigaddset(&G.pending_set, sig);
1452 #if ENABLE_HUSH_FAST
1453 if (sig == SIGCHLD) {
1455 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1460 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1462 struct sigaction old_sa;
1464 /* We could use signal() to install handlers... almost:
1465 * except that we need to mask ALL signals while handlers run.
1466 * I saw signal nesting in strace, race window isn't small.
1467 * SA_RESTART is also needed, but in Linux, signal()
1468 * sets SA_RESTART too.
1470 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1471 /* sigfillset(&G.sa.sa_mask); - already done */
1472 /* G.sa.sa_flags = SA_RESTART; - already done */
1473 G.sa.sa_handler = handler;
1474 sigaction(sig, &G.sa, &old_sa);
1475 return old_sa.sa_handler;
1480 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1481 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1482 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1483 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1485 /* Restores tty foreground process group, and exits.
1486 * May be called as signal handler for fatal signal
1487 * (will resend signal to itself, producing correct exit state)
1488 * or called directly with -EXITCODE.
1489 * We also call it if xfunc is exiting. */
1490 static void sigexit(int sig) NORETURN;
1491 static void sigexit(int sig)
1493 /* Careful: we can end up here after [v]fork. Do not restore
1494 * tty pgrp then, only top-level shell process does that */
1495 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1496 /* Disable all signals: job control, SIGPIPE, etc.
1497 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1499 sigprocmask_allsigs(SIG_BLOCK);
1500 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1503 /* Not a signal, just exit */
1507 kill_myself_with_sig(sig); /* does not return */
1511 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1512 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1516 static sighandler_t pick_sighandler(unsigned sig)
1518 sighandler_t handler = SIG_DFL;
1519 if (sig < sizeof(unsigned)*8) {
1520 unsigned sigmask = (1 << sig);
1524 if (G_fatal_sig_mask & sigmask)
1528 /* sig has special handling? */
1529 if (G.special_sig_mask & sigmask) {
1530 handler = record_pending_signo;
1531 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1532 * in order to ignore them: they will be raised
1533 * in an endless loop when we try to do some
1534 * terminal ioctls! We do have to _ignore_ these.
1536 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1543 /* Restores tty foreground process group, and exits. */
1544 static void hush_exit(int exitcode) NORETURN;
1545 static void hush_exit(int exitcode)
1547 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1548 save_history(G.line_input_state);
1552 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1554 /* argv[0] is unused */
1555 argv[1] = G.traps[0];
1557 G.exiting = 1; /* prevent EXIT trap recursion */
1558 /* Note: G.traps[0] is not cleared!
1559 * "trap" will still show it, if executed
1564 #if ENABLE_FEATURE_CLEAN_UP
1566 struct variable *cur_var;
1567 if (G.cwd != bb_msg_unknown)
1569 cur_var = G.top_var;
1571 struct variable *tmp = cur_var;
1572 if (!cur_var->max_len)
1573 free(cur_var->varstr);
1574 cur_var = cur_var->next;
1582 sigexit(- (exitcode & 0xff));
1589 //TODO: return a mask of ALL handled sigs?
1590 static int check_and_run_traps(void)
1597 if (sigisemptyset(&G.pending_set))
1602 if (sigismember(&G.pending_set, sig)) {
1603 sigdelset(&G.pending_set, sig);
1606 } while (sig < NSIG);
1609 if (G.traps && G.traps[sig]) {
1610 if (G.traps[sig][0]) {
1611 /* We have user-defined handler */
1612 smalluint save_rcode;
1614 /* argv[0] is unused */
1615 argv[1] = G.traps[sig];
1617 save_rcode = G.last_exitcode;
1619 G.last_exitcode = save_rcode;
1621 } /* else: "" trap, ignoring signal */
1624 /* not a trap: special action */
1627 /* Builtin was ^C'ed, make it look prettier: */
1635 /* bash is observed to signal whole process groups,
1636 * not individual processes */
1637 for (job = G.job_list; job; job = job->next) {
1640 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1641 if (kill(- job->pgrp, SIGHUP) == 0)
1642 kill(- job->pgrp, SIGCONT);
1647 #if ENABLE_HUSH_FAST
1650 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1652 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1653 * This simplifies wait builtin a bit.
1657 default: /* ignored: */
1658 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1660 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1661 * Example: wait is not interrupted by TERM
1662 * in interactive shell, because TERM is ignored.
1671 static const char *get_cwd(int force)
1673 if (force || G.cwd == NULL) {
1674 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1675 * we must not try to free(bb_msg_unknown) */
1676 if (G.cwd == bb_msg_unknown)
1678 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1680 G.cwd = bb_msg_unknown;
1687 * Shell and environment variable support
1689 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1691 struct variable **pp;
1692 struct variable *cur;
1695 while ((cur = *pp) != NULL) {
1696 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1703 static const char* FAST_FUNC get_local_var_value(const char *name)
1705 struct variable **vpp;
1706 unsigned len = strlen(name);
1708 if (G.expanded_assignments) {
1709 char **cpp = G.expanded_assignments;
1712 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1713 return cp + len + 1;
1718 vpp = get_ptr_to_local_var(name, len);
1720 return (*vpp)->varstr + len + 1;
1722 if (strcmp(name, "PPID") == 0)
1723 return utoa(G.root_ppid);
1724 // bash compat: UID? EUID?
1725 #if ENABLE_HUSH_RANDOM_SUPPORT
1726 if (strcmp(name, "RANDOM") == 0)
1727 return utoa(next_random(&G.random_gen));
1732 /* str holds "NAME=VAL" and is expected to be malloced.
1733 * We take ownership of it.
1735 * 0: do not change export flag
1736 * (if creating new variable, flag will be 0)
1737 * 1: set export flag and putenv the variable
1738 * -1: clear export flag and unsetenv the variable
1739 * flg_read_only is set only when we handle -R var=val
1741 #if !BB_MMU && ENABLE_HUSH_LOCAL
1742 /* all params are used */
1743 #elif BB_MMU && ENABLE_HUSH_LOCAL
1744 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1745 set_local_var(str, flg_export, local_lvl)
1746 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1747 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1748 set_local_var(str, flg_export)
1749 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1750 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1751 set_local_var(str, flg_export, flg_read_only)
1753 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1755 struct variable **var_pp;
1756 struct variable *cur;
1760 eq_sign = strchr(str, '=');
1761 if (!eq_sign) { /* not expected to ever happen? */
1766 name_len = eq_sign - str + 1; /* including '=' */
1767 var_pp = &G.top_var;
1768 while ((cur = *var_pp) != NULL) {
1769 if (strncmp(cur->varstr, str, name_len) != 0) {
1770 var_pp = &cur->next;
1773 /* We found an existing var with this name */
1774 if (cur->flg_read_only) {
1778 bb_error_msg("%s: readonly variable", str);
1782 if (flg_export == -1) { // "&& cur->flg_export" ?
1783 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1788 #if ENABLE_HUSH_LOCAL
1789 if (cur->func_nest_level < local_lvl) {
1790 /* New variable is declared as local,
1791 * and existing one is global, or local
1792 * from enclosing function.
1793 * Remove and save old one: */
1794 *var_pp = cur->next;
1795 cur->next = *G.shadowed_vars_pp;
1796 *G.shadowed_vars_pp = cur;
1797 /* bash 3.2.33(1) and exported vars:
1799 * # f() { local z=a; env | grep ^z; }
1805 if (cur->flg_export)
1810 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1815 if (cur->max_len != 0) {
1816 if (cur->max_len >= strlen(str)) {
1817 /* This one is from startup env, reuse space */
1818 strcpy(cur->varstr, str);
1822 /* max_len == 0 signifies "malloced" var, which we can
1823 * (and has to) free */
1827 goto set_str_and_exp;
1830 /* Not found - create new variable struct */
1831 cur = xzalloc(sizeof(*cur));
1832 #if ENABLE_HUSH_LOCAL
1833 cur->func_nest_level = local_lvl;
1835 cur->next = *var_pp;
1841 cur->flg_read_only = flg_read_only;
1844 if (flg_export == 1)
1845 cur->flg_export = 1;
1846 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1847 cmdedit_update_prompt();
1848 if (cur->flg_export) {
1849 if (flg_export == -1) {
1850 cur->flg_export = 0;
1851 /* unsetenv was already done */
1853 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1854 return putenv(cur->varstr);
1860 /* Used at startup and after each cd */
1861 static void set_pwd_var(int exp)
1863 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1864 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1867 static int unset_local_var_len(const char *name, int name_len)
1869 struct variable *cur;
1870 struct variable **var_pp;
1873 return EXIT_SUCCESS;
1874 var_pp = &G.top_var;
1875 while ((cur = *var_pp) != NULL) {
1876 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1877 if (cur->flg_read_only) {
1878 bb_error_msg("%s: readonly variable", name);
1879 return EXIT_FAILURE;
1881 *var_pp = cur->next;
1882 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1883 bb_unsetenv(cur->varstr);
1884 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1885 cmdedit_update_prompt();
1889 return EXIT_SUCCESS;
1891 var_pp = &cur->next;
1893 return EXIT_SUCCESS;
1896 static int unset_local_var(const char *name)
1898 return unset_local_var_len(name, strlen(name));
1901 static void unset_vars(char **strings)
1909 const char *eq = strchrnul(*v, '=');
1910 unset_local_var_len(*v, (int)(eq - *v));
1916 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1918 char *var = xasprintf("%s=%s", name, val);
1919 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1924 * Helpers for "var1=val1 var2=val2 cmd" feature
1926 static void add_vars(struct variable *var)
1928 struct variable *next;
1932 var->next = G.top_var;
1934 if (var->flg_export) {
1935 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1936 putenv(var->varstr);
1938 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1944 static struct variable *set_vars_and_save_old(char **strings)
1947 struct variable *old = NULL;
1953 struct variable *var_p;
1954 struct variable **var_pp;
1957 eq = strchr(*s, '=');
1959 var_pp = get_ptr_to_local_var(*s, eq - *s);
1961 /* Remove variable from global linked list */
1963 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1964 *var_pp = var_p->next;
1965 /* Add it to returned list */
1969 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1980 static int FAST_FUNC static_get(struct in_str *i)
1991 static int FAST_FUNC static_peek(struct in_str *i)
1996 #if ENABLE_HUSH_INTERACTIVE
1998 static void cmdedit_update_prompt(void)
2000 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2001 G.PS1 = get_local_var_value("PS1");
2004 G.PS2 = get_local_var_value("PS2");
2012 static const char *setup_prompt_string(int promptmode)
2014 const char *prompt_str;
2015 debug_printf("setup_prompt_string %d ", promptmode);
2016 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2017 /* Set up the prompt */
2018 if (promptmode == 0) { /* PS1 */
2020 /* bash uses $PWD value, even if it is set by user.
2021 * It uses current dir only if PWD is unset.
2022 * We always use current dir. */
2023 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2028 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2029 debug_printf("result '%s'\n", prompt_str);
2033 static void get_user_input(struct in_str *i)
2036 const char *prompt_str;
2038 prompt_str = setup_prompt_string(i->promptmode);
2039 # if ENABLE_FEATURE_EDITING
2040 /* Enable command line editing only while a command line
2041 * is actually being read */
2043 /* Unicode support should be activated even if LANG is set
2044 * _during_ shell execution, not only if it was set when
2045 * shell was started. Therefore, re-check LANG every time:
2047 const char *s = get_local_var_value("LC_ALL");
2048 if (!s) s = get_local_var_value("LANG");
2052 /* buglet: SIGINT will not make new prompt to appear _at once_,
2053 * only after <Enter>. (^C will work) */
2054 r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
2055 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2056 check_and_run_traps();
2057 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2058 i->eof_flag = (r < 0);
2059 if (i->eof_flag) { /* EOF/error detected */
2060 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
2061 G.user_input_buf[1] = '\0';
2066 if (i->last_char == '\0' || i->last_char == '\n') {
2067 /* Why check_and_run_traps here? Try this interactively:
2068 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2069 * $ <[enter], repeatedly...>
2070 * Without check_and_run_traps, handler never runs.
2072 check_and_run_traps();
2073 fputs(prompt_str, stdout);
2076 G.user_input_buf[0] = r = fgetc(i->file);
2077 /*G.user_input_buf[1] = '\0'; - already is and never changed */
2078 } while (G.flag_SIGINT);
2079 i->eof_flag = (r == EOF);
2081 i->p = G.user_input_buf;
2084 #endif /* INTERACTIVE */
2086 /* This is the magic location that prints prompts
2087 * and gets data back from the user */
2088 static int FAST_FUNC file_get(struct in_str *i)
2092 /* If there is data waiting, eat it up */
2093 if (i->p && *i->p) {
2094 #if ENABLE_HUSH_INTERACTIVE
2098 if (i->eof_flag && !*i->p)
2100 /* note: ch is never NUL */
2102 /* need to double check i->file because we might be doing something
2103 * more complicated by now, like sourcing or substituting. */
2104 #if ENABLE_HUSH_INTERACTIVE
2105 if (G_interactive_fd && i->file == stdin) {
2108 } while (!*i->p); /* need non-empty line */
2109 i->promptmode = 1; /* PS2 */
2113 do ch = fgetc(i->file); while (ch == '\0');
2115 debug_printf("file_get: got '%c' %d\n", ch, ch);
2120 /* All callers guarantee this routine will never
2121 * be used right after a newline, so prompting is not needed.
2123 static int FAST_FUNC file_peek(struct in_str *i)
2126 if (i->p && *i->p) {
2127 if (i->eof_flag && !i->p[1])
2130 /* note: ch is never NUL */
2132 do ch = fgetc(i->file); while (ch == '\0');
2133 i->eof_flag = (ch == EOF);
2134 i->peek_buf[0] = ch;
2135 i->peek_buf[1] = '\0';
2137 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2141 static void setup_file_in_str(struct in_str *i, FILE *f)
2143 memset(i, 0, sizeof(*i));
2144 i->peek = file_peek;
2146 /* i->promptmode = 0; - PS1 (memset did it) */
2151 static void setup_string_in_str(struct in_str *i, const char *s)
2153 memset(i, 0, sizeof(*i));
2154 i->peek = static_peek;
2155 i->get = static_get;
2156 /* i->promptmode = 0; - PS1 (memset did it) */
2158 /* i->eof_flag = 0; */
2165 #define B_CHUNK (32 * sizeof(char*))
2167 static void o_reset_to_empty_unquoted(o_string *o)
2170 o->has_quoted_part = 0;
2175 static void o_free(o_string *o)
2178 memset(o, 0, sizeof(*o));
2181 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2186 static void o_grow_by(o_string *o, int len)
2188 if (o->length + len > o->maxlen) {
2189 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2190 o->data = xrealloc(o->data, 1 + o->maxlen);
2194 static void o_addchr(o_string *o, int ch)
2196 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2198 o->data[o->length] = ch;
2200 o->data[o->length] = '\0';
2203 static void o_addblock(o_string *o, const char *str, int len)
2206 memcpy(&o->data[o->length], str, len);
2208 o->data[o->length] = '\0';
2211 static void o_addstr(o_string *o, const char *str)
2213 o_addblock(o, str, strlen(str));
2217 static void nommu_addchr(o_string *o, int ch)
2223 # define nommu_addchr(o, str) ((void)0)
2226 static void o_addstr_with_NUL(o_string *o, const char *str)
2228 o_addblock(o, str, strlen(str) + 1);
2232 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2233 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2234 * Apparently, on unquoted $v bash still does globbing
2235 * ("v='*.txt'; echo $v" prints all .txt files),
2236 * but NOT brace expansion! Thus, there should be TWO independent
2237 * quoting mechanisms on $v expansion side: one protects
2238 * $v from brace expansion, and other additionally protects "$v" against globbing.
2239 * We have only second one.
2242 #if ENABLE_HUSH_BRACE_EXPANSION
2243 # define MAYBE_BRACES "{}"
2245 # define MAYBE_BRACES ""
2248 /* My analysis of quoting semantics tells me that state information
2249 * is associated with a destination, not a source.
2251 static void o_addqchr(o_string *o, int ch)
2254 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2259 o->data[o->length] = '\\';
2262 o->data[o->length] = ch;
2264 o->data[o->length] = '\0';
2267 static void o_addQchr(o_string *o, int ch)
2270 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2271 && strchr("*?[\\" MAYBE_BRACES, ch)
2274 o->data[o->length] = '\\';
2278 o->data[o->length] = ch;
2280 o->data[o->length] = '\0';
2283 static void o_addqblock(o_string *o, const char *str, int len)
2288 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2289 if (ordinary_cnt > len) /* paranoia */
2291 o_addblock(o, str, ordinary_cnt);
2292 if (ordinary_cnt == len)
2293 return; /* NUL is already added by o_addblock */
2294 str += ordinary_cnt;
2295 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2299 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2301 o->data[o->length] = '\\';
2305 o->data[o->length] = ch;
2308 o->data[o->length] = '\0';
2311 static void o_addQblock(o_string *o, const char *str, int len)
2313 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2314 o_addblock(o, str, len);
2317 o_addqblock(o, str, len);
2320 static void o_addQstr(o_string *o, const char *str)
2322 o_addQblock(o, str, strlen(str));
2325 /* A special kind of o_string for $VAR and `cmd` expansion.
2326 * It contains char* list[] at the beginning, which is grown in 16 element
2327 * increments. Actual string data starts at the next multiple of 16 * (char*).
2328 * list[i] contains an INDEX (int!) into this string data.
2329 * It means that if list[] needs to grow, data needs to be moved higher up
2330 * but list[i]'s need not be modified.
2331 * NB: remembering how many list[i]'s you have there is crucial.
2332 * o_finalize_list() operation post-processes this structure - calculates
2333 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2335 #if DEBUG_EXPAND || DEBUG_GLOB
2336 static void debug_print_list(const char *prefix, o_string *o, int n)
2338 char **list = (char**)o->data;
2339 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2343 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2344 prefix, list, n, string_start, o->length, o->maxlen,
2345 !!(o->o_expflags & EXP_FLAG_GLOB),
2347 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2350 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2351 o->data + (int)(uintptr_t)list[i] + string_start,
2352 o->data + (int)(uintptr_t)list[i] + string_start);
2356 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2358 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2362 # define debug_print_list(prefix, o, n) ((void)0)
2365 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2366 * in list[n] so that it points past last stored byte so far.
2367 * It returns n+1. */
2368 static int o_save_ptr_helper(o_string *o, int n)
2370 char **list = (char**)o->data;
2374 if (!o->has_empty_slot) {
2375 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2376 string_len = o->length - string_start;
2377 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2378 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2379 /* list[n] points to string_start, make space for 16 more pointers */
2380 o->maxlen += 0x10 * sizeof(list[0]);
2381 o->data = xrealloc(o->data, o->maxlen + 1);
2382 list = (char**)o->data;
2383 memmove(list + n + 0x10, list + n, string_len);
2384 o->length += 0x10 * sizeof(list[0]);
2386 debug_printf_list("list[%d]=%d string_start=%d\n",
2387 n, string_len, string_start);
2390 /* We have empty slot at list[n], reuse without growth */
2391 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2392 string_len = o->length - string_start;
2393 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2394 n, string_len, string_start);
2395 o->has_empty_slot = 0;
2397 o->has_quoted_part = 0;
2398 list[n] = (char*)(uintptr_t)string_len;
2402 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2403 static int o_get_last_ptr(o_string *o, int n)
2405 char **list = (char**)o->data;
2406 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2408 return ((int)(uintptr_t)list[n-1]) + string_start;
2411 #if ENABLE_HUSH_BRACE_EXPANSION
2412 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2413 * first, it processes even {a} (no commas), second,
2414 * I didn't manage to make it return strings when they don't match
2415 * existing files. Need to re-implement it.
2419 static int glob_needed(const char *s)
2428 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2434 /* Return pointer to next closing brace or to comma */
2435 static const char *next_brace_sub(const char *cp)
2439 while (*cp != '\0') {
2446 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2452 return *cp != '\0' ? cp : NULL;
2454 /* Recursive brace globber. Note: may garble pattern[]. */
2455 static int glob_brace(char *pattern, o_string *o, int n)
2457 char *new_pattern_buf;
2464 debug_printf_glob("glob_brace('%s')\n", pattern);
2470 if (*begin == '{') {
2471 /* Find the first sub-pattern and at the same time
2472 * find the rest after the closing brace */
2473 next = next_brace_sub(begin);
2475 /* An illegal expression */
2479 /* "{abc}" with no commas - illegal
2480 * brace expr, disregard and skip it */
2486 if (*begin == '\\' && begin[1] != '\0')
2490 debug_printf_glob("begin:%s\n", begin);
2491 debug_printf_glob("next:%s\n", next);
2493 /* Now find the end of the whole brace expression */
2495 while (*rest != '}') {
2496 rest = next_brace_sub(rest);
2498 /* An illegal expression */
2501 debug_printf_glob("rest:%s\n", rest);
2503 rest_len = strlen(++rest) + 1;
2505 /* We are sure the brace expression is well-formed */
2507 /* Allocate working buffer large enough for our work */
2508 new_pattern_buf = xmalloc(strlen(pattern));
2510 /* We have a brace expression. BEGIN points to the opening {,
2511 * NEXT points past the terminator of the first element, and REST
2512 * points past the final }. We will accumulate result names from
2513 * recursive runs for each brace alternative in the buffer using
2518 /* Construct the new glob expression */
2521 mempcpy(new_pattern_buf,
2522 /* We know the prefix for all sub-patterns */
2523 pattern, begin - pattern),
2527 /* Note: glob_brace() may garble new_pattern_buf[].
2528 * That's why we re-copy prefix every time (1st memcpy above).
2530 n = glob_brace(new_pattern_buf, o, n);
2532 /* We saw the last entry */
2536 next = next_brace_sub(next);
2538 free(new_pattern_buf);
2546 memset(&globdata, 0, sizeof(globdata));
2547 gr = glob(pattern, 0, NULL, &globdata);
2548 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2550 if (gr == GLOB_NOMATCH) {
2551 globfree(&globdata);
2552 /* NB: garbles parameter */
2553 unbackslash(pattern);
2554 o_addstr_with_NUL(o, pattern);
2555 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2556 return o_save_ptr_helper(o, n);
2558 if (gr == GLOB_NOSPACE)
2559 bb_error_msg_and_die(bb_msg_memory_exhausted);
2560 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2561 * but we didn't specify it. Paranoia again. */
2562 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2564 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2565 char **argv = globdata.gl_pathv;
2567 o_addstr_with_NUL(o, *argv);
2568 n = o_save_ptr_helper(o, n);
2574 globfree(&globdata);
2578 /* Performs globbing on last list[],
2579 * saving each result as a new list[].
2581 static int perform_glob(o_string *o, int n)
2583 char *pattern, *copy;
2585 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2587 return o_save_ptr_helper(o, n);
2588 pattern = o->data + o_get_last_ptr(o, n);
2589 debug_printf_glob("glob pattern '%s'\n", pattern);
2590 if (!glob_needed(pattern)) {
2591 /* unbackslash last string in o in place, fix length */
2592 o->length = unbackslash(pattern) - o->data;
2593 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2594 return o_save_ptr_helper(o, n);
2597 copy = xstrdup(pattern);
2598 /* "forget" pattern in o */
2599 o->length = pattern - o->data;
2600 n = glob_brace(copy, o, n);
2603 debug_print_list("perform_glob returning", o, n);
2607 #else /* !HUSH_BRACE_EXPANSION */
2610 static int glob_needed(const char *s)
2619 if (*s == '*' || *s == '[' || *s == '?')
2625 /* Performs globbing on last list[],
2626 * saving each result as a new list[].
2628 static int perform_glob(o_string *o, int n)
2634 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2636 return o_save_ptr_helper(o, n);
2637 pattern = o->data + o_get_last_ptr(o, n);
2638 debug_printf_glob("glob pattern '%s'\n", pattern);
2639 if (!glob_needed(pattern)) {
2641 /* unbackslash last string in o in place, fix length */
2642 o->length = unbackslash(pattern) - o->data;
2643 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2644 return o_save_ptr_helper(o, n);
2647 memset(&globdata, 0, sizeof(globdata));
2648 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2649 * If we glob "*.\*" and don't find anything, we need
2650 * to fall back to using literal "*.*", but GLOB_NOCHECK
2651 * will return "*.\*"!
2653 gr = glob(pattern, 0, NULL, &globdata);
2654 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2656 if (gr == GLOB_NOMATCH) {
2657 globfree(&globdata);
2660 if (gr == GLOB_NOSPACE)
2661 bb_error_msg_and_die(bb_msg_memory_exhausted);
2662 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2663 * but we didn't specify it. Paranoia again. */
2664 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2666 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2667 char **argv = globdata.gl_pathv;
2668 /* "forget" pattern in o */
2669 o->length = pattern - o->data;
2671 o_addstr_with_NUL(o, *argv);
2672 n = o_save_ptr_helper(o, n);
2678 globfree(&globdata);
2680 debug_print_list("perform_glob returning", o, n);
2684 #endif /* !HUSH_BRACE_EXPANSION */
2686 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2687 * Otherwise, just finish current list[] and start new */
2688 static int o_save_ptr(o_string *o, int n)
2690 if (o->o_expflags & EXP_FLAG_GLOB) {
2691 /* If o->has_empty_slot, list[n] was already globbed
2692 * (if it was requested back then when it was filled)
2693 * so don't do that again! */
2694 if (!o->has_empty_slot)
2695 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2697 return o_save_ptr_helper(o, n);
2700 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2701 static char **o_finalize_list(o_string *o, int n)
2706 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2708 debug_print_list("finalized", o, n);
2709 debug_printf_expand("finalized n:%d\n", n);
2710 list = (char**)o->data;
2711 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2715 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2720 static void free_pipe_list(struct pipe *pi);
2722 /* Returns pi->next - next pipe in the list */
2723 static struct pipe *free_pipe(struct pipe *pi)
2728 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2729 for (i = 0; i < pi->num_cmds; i++) {
2730 struct command *command;
2731 struct redir_struct *r, *rnext;
2733 command = &pi->cmds[i];
2734 debug_printf_clean(" command %d:\n", i);
2735 if (command->argv) {
2739 for (a = 0, p = command->argv; *p; a++, p++) {
2740 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2743 free_strings(command->argv);
2744 //command->argv = NULL;
2746 /* not "else if": on syntax error, we may have both! */
2747 if (command->group) {
2748 debug_printf_clean(" begin group (cmd_type:%d)\n",
2750 free_pipe_list(command->group);
2751 debug_printf_clean(" end group\n");
2752 //command->group = NULL;
2754 /* else is crucial here.
2755 * If group != NULL, child_func is meaningless */
2756 #if ENABLE_HUSH_FUNCTIONS
2757 else if (command->child_func) {
2758 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2759 command->child_func->parent_cmd = NULL;
2763 free(command->group_as_string);
2764 //command->group_as_string = NULL;
2766 for (r = command->redirects; r; r = rnext) {
2767 debug_printf_clean(" redirect %d%s",
2768 r->rd_fd, redir_table[r->rd_type].descrip);
2769 /* guard against the case >$FOO, where foo is unset or blank */
2770 if (r->rd_filename) {
2771 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2772 free(r->rd_filename);
2773 //r->rd_filename = NULL;
2775 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2779 //command->redirects = NULL;
2781 free(pi->cmds); /* children are an array, they get freed all at once */
2785 //pi->cmdtext = NULL;
2793 static void free_pipe_list(struct pipe *pi)
2797 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2799 debug_printf_clean("pipe followup code %d\n", pi->followup);
2805 /*** Parsing routines ***/
2807 #ifndef debug_print_tree
2808 static void debug_print_tree(struct pipe *pi, int lvl)
2810 static const char *const PIPE[] = {
2816 static const char *RES[] = {
2817 [RES_NONE ] = "NONE" ,
2820 [RES_THEN ] = "THEN" ,
2821 [RES_ELIF ] = "ELIF" ,
2822 [RES_ELSE ] = "ELSE" ,
2825 # if ENABLE_HUSH_LOOPS
2826 [RES_FOR ] = "FOR" ,
2827 [RES_WHILE] = "WHILE",
2828 [RES_UNTIL] = "UNTIL",
2830 [RES_DONE ] = "DONE" ,
2832 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2835 # if ENABLE_HUSH_CASE
2836 [RES_CASE ] = "CASE" ,
2837 [RES_CASE_IN ] = "CASE_IN" ,
2838 [RES_MATCH] = "MATCH",
2839 [RES_CASE_BODY] = "CASE_BODY",
2840 [RES_ESAC ] = "ESAC" ,
2842 [RES_XXXX ] = "XXXX" ,
2843 [RES_SNTX ] = "SNTX" ,
2845 static const char *const CMDTYPE[] = {
2849 # if ENABLE_HUSH_FUNCTIONS
2858 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2859 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2861 while (prn < pi->num_cmds) {
2862 struct command *command = &pi->cmds[prn];
2863 char **argv = command->argv;
2865 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
2867 command->assignment_cnt);
2868 if (command->group) {
2869 fdprintf(2, " group %s: (argv=%p)%s%s\n",
2870 CMDTYPE[command->cmd_type],
2873 , " group_as_string:", command->group_as_string
2878 debug_print_tree(command->group, lvl+1);
2882 if (argv) while (*argv) {
2883 fdprintf(2, " '%s'", *argv);
2893 #endif /* debug_print_tree */
2895 static struct pipe *new_pipe(void)
2898 pi = xzalloc(sizeof(struct pipe));
2899 /*pi->followup = 0; - deliberately invalid value */
2900 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2904 /* Command (member of a pipe) is complete, or we start a new pipe
2905 * if ctx->command is NULL.
2906 * No errors possible here.
2908 static int done_command(struct parse_context *ctx)
2910 /* The command is really already in the pipe structure, so
2911 * advance the pipe counter and make a new, null command. */
2912 struct pipe *pi = ctx->pipe;
2913 struct command *command = ctx->command;
2916 if (IS_NULL_CMD(command)) {
2917 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2921 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2922 //debug_print_tree(ctx->list_head, 20);
2924 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2927 /* Only real trickiness here is that the uncommitted
2928 * command structure is not counted in pi->num_cmds. */
2929 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2930 ctx->command = command = &pi->cmds[pi->num_cmds];
2932 memset(command, 0, sizeof(*command));
2933 return pi->num_cmds; /* used only for 0/nonzero check */
2936 static void done_pipe(struct parse_context *ctx, pipe_style type)
2940 debug_printf_parse("done_pipe entered, followup %d\n", type);
2941 /* Close previous command */
2942 not_null = done_command(ctx);
2943 ctx->pipe->followup = type;
2945 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2946 ctx->ctx_inverted = 0;
2947 ctx->pipe->res_word = ctx->ctx_res_w;
2950 /* Without this check, even just <enter> on command line generates
2951 * tree of three NOPs (!). Which is harmless but annoying.
2952 * IOW: it is safe to do it unconditionally. */
2955 || ctx->ctx_res_w == RES_FI
2957 #if ENABLE_HUSH_LOOPS
2958 || ctx->ctx_res_w == RES_DONE
2959 || ctx->ctx_res_w == RES_FOR
2960 || ctx->ctx_res_w == RES_IN
2962 #if ENABLE_HUSH_CASE
2963 || ctx->ctx_res_w == RES_ESAC
2967 debug_printf_parse("done_pipe: adding new pipe: "
2968 "not_null:%d ctx->ctx_res_w:%d\n",
2969 not_null, ctx->ctx_res_w);
2971 ctx->pipe->next = new_p;
2973 /* RES_THEN, RES_DO etc are "sticky" -
2974 * they remain set for pipes inside if/while.
2975 * This is used to control execution.
2976 * RES_FOR and RES_IN are NOT sticky (needed to support
2977 * cases where variable or value happens to match a keyword):
2979 #if ENABLE_HUSH_LOOPS
2980 if (ctx->ctx_res_w == RES_FOR
2981 || ctx->ctx_res_w == RES_IN)
2982 ctx->ctx_res_w = RES_NONE;
2984 #if ENABLE_HUSH_CASE
2985 if (ctx->ctx_res_w == RES_MATCH)
2986 ctx->ctx_res_w = RES_CASE_BODY;
2987 if (ctx->ctx_res_w == RES_CASE)
2988 ctx->ctx_res_w = RES_CASE_IN;
2990 ctx->command = NULL; /* trick done_command below */
2991 /* Create the memory for command, roughly:
2992 * ctx->pipe->cmds = new struct command;
2993 * ctx->command = &ctx->pipe->cmds[0];
2996 //debug_print_tree(ctx->list_head, 10);
2998 debug_printf_parse("done_pipe return\n");
3001 static void initialize_context(struct parse_context *ctx)
3003 memset(ctx, 0, sizeof(*ctx));
3004 ctx->pipe = ctx->list_head = new_pipe();
3005 /* Create the memory for command, roughly:
3006 * ctx->pipe->cmds = new struct command;
3007 * ctx->command = &ctx->pipe->cmds[0];
3012 /* If a reserved word is found and processed, parse context is modified
3013 * and 1 is returned.
3016 struct reserved_combo {
3019 unsigned char assignment_flag;
3023 FLAG_END = (1 << RES_NONE ),
3025 FLAG_IF = (1 << RES_IF ),
3026 FLAG_THEN = (1 << RES_THEN ),
3027 FLAG_ELIF = (1 << RES_ELIF ),
3028 FLAG_ELSE = (1 << RES_ELSE ),
3029 FLAG_FI = (1 << RES_FI ),
3031 # if ENABLE_HUSH_LOOPS
3032 FLAG_FOR = (1 << RES_FOR ),
3033 FLAG_WHILE = (1 << RES_WHILE),
3034 FLAG_UNTIL = (1 << RES_UNTIL),
3035 FLAG_DO = (1 << RES_DO ),
3036 FLAG_DONE = (1 << RES_DONE ),
3037 FLAG_IN = (1 << RES_IN ),
3039 # if ENABLE_HUSH_CASE
3040 FLAG_MATCH = (1 << RES_MATCH),
3041 FLAG_ESAC = (1 << RES_ESAC ),
3043 FLAG_START = (1 << RES_XXXX ),
3046 static const struct reserved_combo* match_reserved_word(o_string *word)
3048 /* Mostly a list of accepted follow-up reserved words.
3049 * FLAG_END means we are done with the sequence, and are ready
3050 * to turn the compound list into a command.
3051 * FLAG_START means the word must start a new compound list.
3053 static const struct reserved_combo reserved_list[] = {
3055 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3056 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3057 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3058 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3059 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3060 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3062 # if ENABLE_HUSH_LOOPS
3063 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3064 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3065 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3066 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3067 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3068 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3070 # if ENABLE_HUSH_CASE
3071 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3072 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3075 const struct reserved_combo *r;
3077 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3078 if (strcmp(word->data, r->literal) == 0)
3083 /* Return 0: not a keyword, 1: keyword
3085 static int reserved_word(o_string *word, struct parse_context *ctx)
3087 # if ENABLE_HUSH_CASE
3088 static const struct reserved_combo reserved_match = {
3089 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3092 const struct reserved_combo *r;
3094 if (word->has_quoted_part)
3096 r = match_reserved_word(word);
3100 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3101 # if ENABLE_HUSH_CASE
3102 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3103 /* "case word IN ..." - IN part starts first MATCH part */
3104 r = &reserved_match;
3107 if (r->flag == 0) { /* '!' */
3108 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3109 syntax_error("! ! command");
3110 ctx->ctx_res_w = RES_SNTX;
3112 ctx->ctx_inverted = 1;
3115 if (r->flag & FLAG_START) {
3116 struct parse_context *old;
3118 old = xmalloc(sizeof(*old));
3119 debug_printf_parse("push stack %p\n", old);
3120 *old = *ctx; /* physical copy */
3121 initialize_context(ctx);
3123 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3124 syntax_error_at(word->data);
3125 ctx->ctx_res_w = RES_SNTX;
3128 /* "{...} fi" is ok. "{...} if" is not
3130 * if { echo foo; } then { echo bar; } fi */
3131 if (ctx->command->group)
3132 done_pipe(ctx, PIPE_SEQ);
3135 ctx->ctx_res_w = r->res;
3136 ctx->old_flag = r->flag;
3137 word->o_assignment = r->assignment_flag;
3138 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3140 if (ctx->old_flag & FLAG_END) {
3141 struct parse_context *old;
3143 done_pipe(ctx, PIPE_SEQ);
3144 debug_printf_parse("pop stack %p\n", ctx->stack);
3146 old->command->group = ctx->list_head;
3147 old->command->cmd_type = CMD_NORMAL;
3149 o_addstr(&old->as_string, ctx->as_string.data);
3150 o_free_unsafe(&ctx->as_string);
3151 old->command->group_as_string = xstrdup(old->as_string.data);
3152 debug_printf_parse("pop, remembering as:'%s'\n",
3153 old->command->group_as_string);
3155 *ctx = *old; /* physical copy */
3160 #endif /* HAS_KEYWORDS */
3162 /* Word is complete, look at it and update parsing context.
3163 * Normal return is 0. Syntax errors return 1.
3164 * Note: on return, word is reset, but not o_free'd!
3166 static int done_word(o_string *word, struct parse_context *ctx)
3168 struct command *command = ctx->command;
3170 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3171 if (word->length == 0 && !word->has_quoted_part) {
3172 debug_printf_parse("done_word return 0: true null, ignored\n");
3176 if (ctx->pending_redirect) {
3177 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3178 * only if run as "bash", not "sh" */
3179 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3181 * ...the word that follows the redirection operator
3182 * shall be subjected to tilde expansion, parameter expansion,
3183 * command substitution, arithmetic expansion, and quote
3184 * removal. Pathname expansion shall not be performed
3185 * on the word by a non-interactive shell; an interactive
3186 * shell may perform it, but shall do so only when
3187 * the expansion would result in one word."
3189 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3190 /* Cater for >\file case:
3191 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3192 * Same with heredocs:
3193 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3195 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3196 unbackslash(ctx->pending_redirect->rd_filename);
3197 /* Is it <<"HEREDOC"? */
3198 if (word->has_quoted_part) {
3199 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3202 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3203 ctx->pending_redirect = NULL;
3206 # if ENABLE_HUSH_CASE
3207 if (ctx->ctx_dsemicolon
3208 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3210 /* already done when ctx_dsemicolon was set to 1: */
3211 /* ctx->ctx_res_w = RES_MATCH; */
3212 ctx->ctx_dsemicolon = 0;
3215 if (!command->argv /* if it's the first word... */
3216 # if ENABLE_HUSH_LOOPS
3217 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3218 && ctx->ctx_res_w != RES_IN
3220 # if ENABLE_HUSH_CASE
3221 && ctx->ctx_res_w != RES_CASE
3224 int reserved = reserved_word(word, ctx);
3225 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3227 o_reset_to_empty_unquoted(word);
3228 debug_printf_parse("done_word return %d\n",
3229 (ctx->ctx_res_w == RES_SNTX));
3230 return (ctx->ctx_res_w == RES_SNTX);
3232 # if ENABLE_HUSH_BASH_COMPAT
3233 if (strcmp(word->data, "[[") == 0) {
3234 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3240 if (command->group) {
3241 /* "{ echo foo; } echo bar" - bad */
3242 syntax_error_at(word->data);
3243 debug_printf_parse("done_word return 1: syntax error, "
3244 "groups and arglists don't mix\n");
3248 /* If this word wasn't an assignment, next ones definitely
3249 * can't be assignments. Even if they look like ones. */
3250 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3251 && word->o_assignment != WORD_IS_KEYWORD
3253 word->o_assignment = NOT_ASSIGNMENT;
3255 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3256 command->assignment_cnt++;
3257 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3259 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3260 word->o_assignment = MAYBE_ASSIGNMENT;
3262 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3264 if (word->has_quoted_part
3265 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3266 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3267 /* (otherwise it's known to be not empty and is already safe) */
3269 /* exclude "$@" - it can expand to no word despite "" */
3270 char *p = word->data;
3271 while (p[0] == SPECIAL_VAR_SYMBOL
3272 && (p[1] & 0x7f) == '@'
3273 && p[2] == SPECIAL_VAR_SYMBOL
3278 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3279 debug_print_strings("word appended to argv", command->argv);
3282 #if ENABLE_HUSH_LOOPS
3283 if (ctx->ctx_res_w == RES_FOR) {
3284 if (word->has_quoted_part
3285 || !is_well_formed_var_name(command->argv[0], '\0')
3287 /* bash says just "not a valid identifier" */
3288 syntax_error("not a valid identifier in for");
3291 /* Force FOR to have just one word (variable name) */
3292 /* NB: basically, this makes hush see "for v in ..."
3293 * syntax as if it is "for v; in ...". FOR and IN become
3294 * two pipe structs in parse tree. */
3295 done_pipe(ctx, PIPE_SEQ);
3298 #if ENABLE_HUSH_CASE
3299 /* Force CASE to have just one word */
3300 if (ctx->ctx_res_w == RES_CASE) {
3301 done_pipe(ctx, PIPE_SEQ);
3305 o_reset_to_empty_unquoted(word);
3307 debug_printf_parse("done_word return 0\n");
3312 /* Peek ahead in the input to find out if we have a "&n" construct,
3313 * as in "2>&1", that represents duplicating a file descriptor.
3315 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3316 * REDIRFD_SYNTAX_ERR if syntax error,
3317 * REDIRFD_TO_FILE if no & was seen,
3318 * or the number found.
3321 #define parse_redir_right_fd(as_string, input) \
3322 parse_redir_right_fd(input)
3324 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3330 return REDIRFD_TO_FILE;
3332 ch = i_getch(input); /* get the & */
3333 nommu_addchr(as_string, ch);
3336 ch = i_getch(input);
3337 nommu_addchr(as_string, ch);
3338 return REDIRFD_CLOSE;
3342 while (ch != EOF && isdigit(ch)) {
3343 d = d*10 + (ch-'0');
3345 ch = i_getch(input);
3346 nommu_addchr(as_string, ch);
3351 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3353 bb_error_msg("ambiguous redirect");
3354 return REDIRFD_SYNTAX_ERR;
3357 /* Return code is 0 normal, 1 if a syntax error is detected
3359 static int parse_redirect(struct parse_context *ctx,
3362 struct in_str *input)
3364 struct command *command = ctx->command;
3365 struct redir_struct *redir;
3366 struct redir_struct **redirp;
3369 dup_num = REDIRFD_TO_FILE;
3370 if (style != REDIRECT_HEREDOC) {
3371 /* Check for a '>&1' type redirect */
3372 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3373 if (dup_num == REDIRFD_SYNTAX_ERR)
3376 int ch = i_peek(input);
3377 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3378 if (dup_num) { /* <<-... */
3379 ch = i_getch(input);
3380 nommu_addchr(&ctx->as_string, ch);
3385 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3386 int ch = i_peek(input);
3388 /* >|FILE redirect ("clobbering" >).
3389 * Since we do not support "set -o noclobber" yet,
3390 * >| and > are the same for now. Just eat |.
3392 ch = i_getch(input);
3393 nommu_addchr(&ctx->as_string, ch);
3397 /* Create a new redir_struct and append it to the linked list */
3398 redirp = &command->redirects;
3399 while ((redir = *redirp) != NULL) {
3400 redirp = &(redir->next);
3402 *redirp = redir = xzalloc(sizeof(*redir));
3403 /* redir->next = NULL; */
3404 /* redir->rd_filename = NULL; */
3405 redir->rd_type = style;
3406 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3408 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3409 redir_table[style].descrip);
3411 redir->rd_dup = dup_num;
3412 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3413 /* Erik had a check here that the file descriptor in question
3414 * is legit; I postpone that to "run time"
3415 * A "-" representation of "close me" shows up as a -3 here */
3416 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3417 redir->rd_fd, redir->rd_dup);
3419 /* Set ctx->pending_redirect, so we know what to do at the
3420 * end of the next parsed word. */
3421 ctx->pending_redirect = redir;
3426 /* If a redirect is immediately preceded by a number, that number is
3427 * supposed to tell which file descriptor to redirect. This routine
3428 * looks for such preceding numbers. In an ideal world this routine
3429 * needs to handle all the following classes of redirects...
3430 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3431 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3432 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3433 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3435 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3437 * ... If n is quoted, the number shall not be recognized as part of
3438 * the redirection expression. For example:
3440 * writes the character 2 into file a"
3441 * We are getting it right by setting ->has_quoted_part on any \<char>
3443 * A -1 return means no valid number was found,
3444 * the caller should use the appropriate default for this redirection.
3446 static int redirect_opt_num(o_string *o)
3450 if (o->data == NULL)
3452 num = bb_strtou(o->data, NULL, 10);
3453 if (errno || num < 0)
3455 o_reset_to_empty_unquoted(o);
3460 #define fetch_till_str(as_string, input, word, skip_tabs) \
3461 fetch_till_str(input, word, skip_tabs)
3463 static char *fetch_till_str(o_string *as_string,
3464 struct in_str *input,
3468 o_string heredoc = NULL_O_STRING;
3470 int prev = 0; /* not \ */
3476 ch = i_getch(input);
3478 nommu_addchr(as_string, ch);
3479 if ((ch == '\n' || ch == EOF)
3480 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3482 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3483 heredoc.data[past_EOL] = '\0';
3484 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3485 return heredoc.data;
3487 while (ch == '\n') {
3488 o_addchr(&heredoc, ch);
3491 past_EOL = heredoc.length;
3493 ch = i_getch(input);
3495 nommu_addchr(as_string, ch);
3496 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3500 o_free_unsafe(&heredoc);
3503 o_addchr(&heredoc, ch);
3504 nommu_addchr(as_string, ch);
3505 if (prev == '\\' && ch == '\\')
3506 /* Correctly handle foo\\<eol> (not a line cont.) */
3507 prev = 0; /* not \ */
3513 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3514 * and load them all. There should be exactly heredoc_cnt of them.
3516 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3518 struct pipe *pi = ctx->list_head;
3520 while (pi && heredoc_cnt) {
3522 struct command *cmd = pi->cmds;
3524 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3526 cmd->argv ? cmd->argv[0] : "NONE");
3527 for (i = 0; i < pi->num_cmds; i++) {
3528 struct redir_struct *redir = cmd->redirects;
3530 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3531 i, cmd->argv ? cmd->argv[0] : "NONE");
3533 if (redir->rd_type == REDIRECT_HEREDOC) {
3536 redir->rd_type = REDIRECT_HEREDOC2;
3537 /* redir->rd_dup is (ab)used to indicate <<- */
3538 p = fetch_till_str(&ctx->as_string, input,
3539 redir->rd_filename, redir->rd_dup);
3541 syntax_error("unexpected EOF in here document");
3544 free(redir->rd_filename);
3545 redir->rd_filename = p;
3548 redir = redir->next;
3555 /* Should be 0. If it isn't, it's a parse error */
3557 bb_error_msg_and_die("heredoc BUG 2");
3563 static int run_list(struct pipe *pi);
3565 #define parse_stream(pstring, input, end_trigger) \
3566 parse_stream(input, end_trigger)
3568 static struct pipe *parse_stream(char **pstring,
3569 struct in_str *input,
3573 #if !ENABLE_HUSH_FUNCTIONS
3574 #define parse_group(dest, ctx, input, ch) \
3575 parse_group(ctx, input, ch)
3577 static int parse_group(o_string *dest, struct parse_context *ctx,
3578 struct in_str *input, int ch)
3580 /* dest contains characters seen prior to ( or {.
3581 * Typically it's empty, but for function defs,
3582 * it contains function name (without '()'). */
3583 struct pipe *pipe_list;
3585 struct command *command = ctx->command;
3587 debug_printf_parse("parse_group entered\n");
3588 #if ENABLE_HUSH_FUNCTIONS
3589 if (ch == '(' && !dest->has_quoted_part) {
3591 if (done_word(dest, ctx))
3594 goto skip; /* (... */
3595 if (command->argv[1]) { /* word word ... (... */
3596 syntax_error_unexpected_ch('(');
3599 /* it is "word(..." or "word (..." */
3601 ch = i_getch(input);
3602 while (ch == ' ' || ch == '\t');
3604 syntax_error_unexpected_ch(ch);
3607 nommu_addchr(&ctx->as_string, ch);
3609 ch = i_getch(input);
3610 while (ch == ' ' || ch == '\t' || ch == '\n');
3612 syntax_error_unexpected_ch(ch);
3615 nommu_addchr(&ctx->as_string, ch);
3616 command->cmd_type = CMD_FUNCDEF;
3621 #if 0 /* Prevented by caller */
3622 if (command->argv /* word [word]{... */
3623 || dest->length /* word{... */
3624 || dest->has_quoted_part /* ""{... */
3627 debug_printf_parse("parse_group return 1: "
3628 "syntax error, groups and arglists don't mix\n");
3633 #if ENABLE_HUSH_FUNCTIONS
3639 command->cmd_type = CMD_SUBSHELL;
3641 /* bash does not allow "{echo...", requires whitespace */
3642 ch = i_getch(input);
3643 if (ch != ' ' && ch != '\t' && ch != '\n') {
3644 syntax_error_unexpected_ch(ch);
3647 nommu_addchr(&ctx->as_string, ch);
3652 # define as_string NULL
3654 char *as_string = NULL;
3656 pipe_list = parse_stream(&as_string, input, endch);
3659 o_addstr(&ctx->as_string, as_string);
3661 /* empty ()/{} or parse error? */
3662 if (!pipe_list || pipe_list == ERR_PTR) {
3663 /* parse_stream already emitted error msg */
3666 debug_printf_parse("parse_group return 1: "
3667 "parse_stream returned %p\n", pipe_list);
3670 command->group = pipe_list;
3672 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3673 command->group_as_string = as_string;
3674 debug_printf_parse("end of group, remembering as:'%s'\n",
3675 command->group_as_string);
3679 debug_printf_parse("parse_group return 0\n");
3681 /* command remains "open", available for possible redirects */
3684 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3685 /* Subroutines for copying $(...) and `...` things */
3686 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3688 static int add_till_single_quote(o_string *dest, struct in_str *input)
3691 int ch = i_getch(input);
3693 syntax_error_unterm_ch('\'');
3701 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3702 static int add_till_double_quote(o_string *dest, struct in_str *input)
3705 int ch = i_getch(input);
3707 syntax_error_unterm_ch('"');
3712 if (ch == '\\') { /* \x. Copy both chars. */
3714 ch = i_getch(input);
3718 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
3723 //if (ch == '$') ...
3726 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3728 * "Within the backquoted style of command substitution, backslash
3729 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3730 * The search for the matching backquote shall be satisfied by the first
3731 * backquote found without a preceding backslash; during this search,
3732 * if a non-escaped backquote is encountered within a shell comment,
3733 * a here-document, an embedded command substitution of the $(command)
3734 * form, or a quoted string, undefined results occur. A single-quoted
3735 * or double-quoted string that begins, but does not end, within the
3736 * "`...`" sequence produces undefined results."
3738 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3740 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3743 int ch = i_getch(input);
3747 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3748 ch = i_getch(input);
3752 && (!in_dquote || ch != '"')
3754 o_addchr(dest, '\\');
3758 syntax_error_unterm_ch('`');
3764 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3765 * quoting and nested ()s.
3766 * "With the $(command) style of command substitution, all characters
3767 * following the open parenthesis to the matching closing parenthesis
3768 * constitute the command. Any valid shell script can be used for command,
3769 * except a script consisting solely of redirections which produces
3770 * unspecified results."
3772 * echo $(echo '(TEST)' BEST) (TEST) BEST
3773 * echo $(echo 'TEST)' BEST) TEST) BEST
3774 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3776 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3777 * can contain arbitrary constructs, just like $(cmd).
3778 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3779 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3781 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3782 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3785 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3786 # if ENABLE_HUSH_BASH_COMPAT
3787 char end_char2 = end_ch >> 8;
3789 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3792 ch = i_getch(input);
3794 syntax_error_unterm_ch(end_ch);
3797 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3800 /* we look for closing )) of $((EXPR)) */
3801 if (i_peek(input) == end_ch) {
3802 i_getch(input); /* eat second ')' */
3807 if (ch == '(' || ch == '{') {
3808 ch = (ch == '(' ? ')' : '}');
3809 if (!add_till_closing_bracket(dest, input, ch))
3815 if (!add_till_single_quote(dest, input))
3821 if (!add_till_double_quote(dest, input))
3827 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
3833 /* \x. Copy verbatim. Important for \(, \) */
3834 ch = i_getch(input);
3836 syntax_error_unterm_ch(')');
3845 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3847 /* Return code: 0 for OK, 1 for syntax error */
3849 #define parse_dollar(as_string, dest, input, quote_mask) \
3850 parse_dollar(dest, input, quote_mask)
3851 #define as_string NULL
3853 static int parse_dollar(o_string *as_string,
3855 struct in_str *input, unsigned char quote_mask)
3857 int ch = i_peek(input); /* first character after the $ */
3859 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3861 ch = i_getch(input);
3862 nommu_addchr(as_string, ch);
3864 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3866 debug_printf_parse(": '%c'\n", ch);
3867 o_addchr(dest, ch | quote_mask);
3870 if (!isalnum(ch) && ch != '_')
3872 ch = i_getch(input);
3873 nommu_addchr(as_string, ch);
3875 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3876 } else if (isdigit(ch)) {
3878 ch = i_getch(input);
3879 nommu_addchr(as_string, ch);
3880 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3881 debug_printf_parse(": '%c'\n", ch);
3882 o_addchr(dest, ch | quote_mask);
3883 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3884 } else switch (ch) {
3886 case '!': /* last bg pid */
3887 case '?': /* last exit code */
3888 case '#': /* number of args */
3889 case '*': /* args */
3890 case '@': /* args */
3891 goto make_one_char_var;
3893 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3895 ch = i_getch(input); /* eat '{' */
3896 nommu_addchr(as_string, ch);
3898 ch = i_getch(input); /* first char after '{' */
3899 /* It should be ${?}, or ${#var},
3900 * or even ${?+subst} - operator acting on a special variable,
3901 * or the beginning of variable name.
3904 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3907 syntax_error_unterm_str("${name}");
3908 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
3911 nommu_addchr(as_string, ch);
3914 /* It's possible to just call add_till_closing_bracket() at this point.
3915 * However, this regresses some of our testsuite cases
3916 * which check invalid constructs like ${%}.
3917 * Oh well... let's check that the var name part is fine... */
3923 debug_printf_parse(": '%c'\n", ch);
3925 ch = i_getch(input);
3926 nommu_addchr(as_string, ch);
3930 if (!isalnum(ch) && ch != '_') {
3932 unsigned char last_ch;
3933 /* handle parameter expansions
3934 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3936 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3937 goto bad_dollar_syntax;
3939 /* Eat everything until closing '}' (or ':') */
3941 if (ENABLE_HUSH_BASH_COMPAT
3943 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3945 /* It's ${var:N[:M]} thing */
3946 end_ch = '}' * 0x100 + ':';
3948 if (ENABLE_HUSH_BASH_COMPAT
3951 /* It's ${var/[/]pattern[/repl]} thing */
3952 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3954 nommu_addchr(as_string, '/');
3957 end_ch = '}' * 0x100 + '/';
3963 #if ENABLE_HUSH_DOLLAR_OPS
3964 last_ch = add_till_closing_bracket(dest, input, end_ch);
3965 if (last_ch == 0) /* error? */
3968 #error Simple code to only allow ${var} is not implemented
3971 o_addstr(as_string, dest->data + pos);
3972 o_addchr(as_string, last_ch);
3975 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3976 /* close the first block: */
3977 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3978 /* while parsing N from ${var:N[:M]}
3979 * or pattern from ${var/[/]pattern[/repl]} */
3980 if ((end_ch & 0xff) == last_ch) {
3981 /* got ':' or '/'- parse the rest */
3986 if (end_ch == '}' * 0x100 + ':') {
3987 /* it's ${var:N} - emulate :999999999 */
3988 o_addstr(dest, "999999999");
3989 } /* else: it's ${var/[/]pattern} */
3994 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3997 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4001 ch = i_getch(input);
4002 nommu_addchr(as_string, ch);
4003 # if ENABLE_SH_MATH_SUPPORT
4004 if (i_peek(input) == '(') {
4005 ch = i_getch(input);
4006 nommu_addchr(as_string, ch);
4007 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4008 o_addchr(dest, /*quote_mask |*/ '+');
4011 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4012 return 0; /* error */
4014 o_addstr(as_string, dest->data + pos);
4015 o_addchr(as_string, ')');
4016 o_addchr(as_string, ')');
4018 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4022 # if ENABLE_HUSH_TICK
4023 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4024 o_addchr(dest, quote_mask | '`');
4027 if (!add_till_closing_bracket(dest, input, ')'))
4028 return 0; /* error */
4030 o_addstr(as_string, dest->data + pos);
4031 o_addchr(as_string, ')');
4033 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4039 ch = i_getch(input);
4040 nommu_addchr(as_string, ch);
4042 if (isalnum(ch)) { /* it's $_name or $_123 */
4047 /* TODO: $_ and $-: */
4048 /* $_ Shell or shell script name; or last argument of last command
4049 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4050 * but in command's env, set to full pathname used to invoke it */
4051 /* $- Option flags set by set builtin or shell options (-i etc) */
4053 o_addQchr(dest, '$');
4055 debug_printf_parse("parse_dollar return 1 (ok)\n");
4061 # if ENABLE_HUSH_BASH_COMPAT
4062 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4063 encode_string(dest, input, dquote_end, process_bkslash)
4065 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4066 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4067 encode_string(dest, input, dquote_end)
4069 #define as_string NULL
4073 # if ENABLE_HUSH_BASH_COMPAT
4074 /* all parameters are needed, no macro tricks */
4076 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4077 encode_string(as_string, dest, input, dquote_end)
4080 static int encode_string(o_string *as_string,
4082 struct in_str *input,
4084 int process_bkslash)
4086 #if !ENABLE_HUSH_BASH_COMPAT
4087 const int process_bkslash = 1;
4093 ch = i_getch(input);
4095 nommu_addchr(as_string, ch);
4096 if (ch == dquote_end) { /* may be only '"' or EOF */
4097 debug_printf_parse("encode_string return 1 (ok)\n");
4100 /* note: can't move it above ch == dquote_end check! */
4102 syntax_error_unterm_ch('"');
4103 return 0; /* error */
4107 next = i_peek(input);
4109 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4110 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4111 if (process_bkslash && ch == '\\') {
4113 syntax_error("\\<eof>");
4117 * "The backslash retains its special meaning [in "..."]
4118 * only when followed by one of the following characters:
4119 * $, `, ", \, or <newline>. A double quote may be quoted
4120 * within double quotes by preceding it with a backslash."
4121 * NB: in (unquoted) heredoc, above does not apply to ",
4122 * therefore we check for it by "next == dquote_end" cond.
4124 if (next == dquote_end || strchr("$`\\\n", next)) {
4125 ch = i_getch(input); /* eat next */
4127 goto again; /* skip \<newline> */
4128 } /* else: ch remains == '\\', and we double it below: */
4129 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4130 nommu_addchr(as_string, ch);
4134 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4135 debug_printf_parse("encode_string return 0: "
4136 "parse_dollar returned 0 (error)\n");
4141 #if ENABLE_HUSH_TICK
4143 //unsigned pos = dest->length;
4144 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4145 o_addchr(dest, 0x80 | '`');
4146 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4147 return 0; /* error */
4148 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4149 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4153 o_addQchr(dest, ch);
4159 * Scan input until EOF or end_trigger char.
4160 * Return a list of pipes to execute, or NULL on EOF
4161 * or if end_trigger character is met.
4162 * On syntax error, exit if shell is not interactive,
4163 * reset parsing machinery and start parsing anew,
4164 * or return ERR_PTR.
4166 static struct pipe *parse_stream(char **pstring,
4167 struct in_str *input,
4170 struct parse_context ctx;
4171 o_string dest = NULL_O_STRING;
4174 /* Single-quote triggers a bypass of the main loop until its mate is
4175 * found. When recursing, quote state is passed in via dest->o_expflags.
4177 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4178 end_trigger ? end_trigger : 'X');
4181 /* If very first arg is "" or '', dest.data may end up NULL.
4182 * Preventing this: */
4183 o_addchr(&dest, '\0');
4186 /* We used to separate words on $IFS here. This was wrong.
4187 * $IFS is used only for word splitting when $var is expanded,
4188 * here we should use blank chars as separators, not $IFS
4191 if (MAYBE_ASSIGNMENT != 0)
4192 dest.o_assignment = MAYBE_ASSIGNMENT;
4193 initialize_context(&ctx);
4196 const char *is_blank;
4197 const char *is_special;
4201 redir_type redir_style;
4203 ch = i_getch(input);
4204 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4205 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4210 syntax_error_unterm_str("here document");
4213 /* end_trigger == '}' case errors out earlier,
4214 * checking only ')' */
4215 if (end_trigger == ')') {
4216 syntax_error_unterm_ch('(');
4220 if (done_word(&dest, &ctx)) {
4224 done_pipe(&ctx, PIPE_SEQ);
4226 /* If we got nothing... */
4227 /* (this makes bare "&" cmd a no-op.
4228 * bash says: "syntax error near unexpected token '&'") */
4229 if (pi->num_cmds == 0
4230 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4236 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4238 *pstring = ctx.as_string.data;
4240 o_free_unsafe(&ctx.as_string);
4243 debug_printf_parse("parse_stream return %p\n", pi);
4246 nommu_addchr(&ctx.as_string, ch);
4250 next = i_peek(input);
4252 is_special = "{}<>;&|()#'" /* special outside of "str" */
4253 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4254 /* Are { and } special here? */
4255 if (ctx.command->argv /* word [word]{... - non-special */
4256 || dest.length /* word{... - non-special */
4257 || dest.has_quoted_part /* ""{... - non-special */
4258 || (next != ';' /* }; - special */
4259 && next != ')' /* }) - special */
4260 && next != '&' /* }& and }&& ... - special */
4261 && next != '|' /* }|| ... - special */
4262 && !strchr(defifs, next) /* {word - non-special */
4265 /* They are not special, skip "{}" */
4268 is_special = strchr(is_special, ch);
4269 is_blank = strchr(defifs, ch);
4271 if (!is_special && !is_blank) { /* ordinary char */
4273 o_addQchr(&dest, ch);
4274 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4275 || dest.o_assignment == WORD_IS_KEYWORD)
4277 && is_well_formed_var_name(dest.data, '=')
4279 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4280 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4286 if (done_word(&dest, &ctx)) {
4290 /* Is this a case when newline is simply ignored?
4292 * "cmd | <newline> cmd ..."
4293 * "case ... in <newline> word) ..."
4295 if (IS_NULL_CMD(ctx.command)
4296 && dest.length == 0 && !dest.has_quoted_part
4298 /* This newline can be ignored. But...
4299 * Without check #1, interactive shell
4300 * ignores even bare <newline>,
4301 * and shows the continuation prompt:
4302 * ps1_prompt$ <enter>
4303 * ps2> _ <=== wrong, should be ps1
4304 * Without check #2, "cmd & <newline>"
4305 * is similarly mistreated.
4306 * (BTW, this makes "cmd & cmd"
4307 * and "cmd && cmd" non-orthogonal.
4308 * Really, ask yourself, why
4309 * "cmd && <newline>" doesn't start
4310 * cmd but waits for more input?
4313 struct pipe *pi = ctx.list_head;
4314 if (pi->num_cmds != 0 /* check #1 */
4315 && pi->followup != PIPE_BG /* check #2 */
4320 /* Treat newline as a command separator. */
4321 done_pipe(&ctx, PIPE_SEQ);
4322 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4324 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4329 dest.o_assignment = MAYBE_ASSIGNMENT;
4330 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4332 /* note: if (is_blank) continue;
4333 * will still trigger for us */
4337 /* "cmd}" or "cmd }..." without semicolon or &:
4338 * } is an ordinary char in this case, even inside { cmd; }
4339 * Pathological example: { ""}; } should exec "}" cmd
4342 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4343 || dest.length != 0 /* word} */
4344 || dest.has_quoted_part /* ""} */
4348 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4349 goto skip_end_trigger;
4350 /* else: } does terminate a group */
4353 if (end_trigger && end_trigger == ch
4354 && (ch != ';' || heredoc_cnt == 0)
4355 #if ENABLE_HUSH_CASE
4357 || ctx.ctx_res_w != RES_MATCH
4358 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4363 /* This is technically valid:
4364 * { cat <<HERE; }; echo Ok
4368 * but we don't support this.
4369 * We require heredoc to be in enclosing {}/(),
4372 syntax_error_unterm_str("here document");
4375 if (done_word(&dest, &ctx)) {
4378 done_pipe(&ctx, PIPE_SEQ);
4379 dest.o_assignment = MAYBE_ASSIGNMENT;
4380 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4381 /* Do we sit outside of any if's, loops or case's? */
4383 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4387 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4389 *pstring = ctx.as_string.data;
4391 o_free_unsafe(&ctx.as_string);
4394 debug_printf_parse("parse_stream return %p: "
4395 "end_trigger char found\n",
4397 return ctx.list_head;
4404 /* Catch <, > before deciding whether this word is
4405 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4408 redir_fd = redirect_opt_num(&dest);
4409 if (done_word(&dest, &ctx)) {
4412 redir_style = REDIRECT_OVERWRITE;
4414 redir_style = REDIRECT_APPEND;
4415 ch = i_getch(input);
4416 nommu_addchr(&ctx.as_string, ch);
4419 else if (next == '(') {
4420 syntax_error(">(process) not supported");
4424 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4426 continue; /* back to top of while (1) */
4428 redir_fd = redirect_opt_num(&dest);
4429 if (done_word(&dest, &ctx)) {
4432 redir_style = REDIRECT_INPUT;
4434 redir_style = REDIRECT_HEREDOC;
4436 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4437 ch = i_getch(input);
4438 nommu_addchr(&ctx.as_string, ch);
4439 } else if (next == '>') {
4440 redir_style = REDIRECT_IO;
4441 ch = i_getch(input);
4442 nommu_addchr(&ctx.as_string, ch);
4445 else if (next == '(') {
4446 syntax_error("<(process) not supported");
4450 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4452 continue; /* back to top of while (1) */
4454 if (dest.length == 0 && !dest.has_quoted_part) {
4455 /* skip "#comment" */
4458 if (ch == EOF || ch == '\n')
4461 /* note: we do not add it to &ctx.as_string */
4463 nommu_addchr(&ctx.as_string, '\n');
4464 continue; /* back to top of while (1) */
4469 /* It's "\<newline>" */
4471 /* Remove trailing '\' from ctx.as_string */
4472 ctx.as_string.data[--ctx.as_string.length] = '\0';
4474 ch = i_getch(input); /* eat it */
4475 continue; /* back to top of while (1) */
4480 if (dest.o_assignment == MAYBE_ASSIGNMENT
4481 /* check that we are not in word in "a=1 2>word b=1": */
4482 && !ctx.pending_redirect
4484 /* ch is a special char and thus this word
4485 * cannot be an assignment */
4486 dest.o_assignment = NOT_ASSIGNMENT;
4487 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4490 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4493 case '#': /* non-comment #: "echo a#b" etc */
4494 o_addQchr(&dest, ch);
4498 syntax_error("\\<eof>");
4501 ch = i_getch(input);
4502 /* note: ch != '\n' (that case does not reach this place) */
4503 o_addchr(&dest, '\\');
4504 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4505 o_addchr(&dest, ch);
4506 nommu_addchr(&ctx.as_string, ch);
4507 /* Example: echo Hello \2>file
4508 * we need to know that word 2 is quoted */
4509 dest.has_quoted_part = 1;
4512 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4513 debug_printf_parse("parse_stream parse error: "
4514 "parse_dollar returned 0 (error)\n");
4519 dest.has_quoted_part = 1;
4520 if (next == '\'' && !ctx.pending_redirect) {
4521 insert_empty_quoted_str_marker:
4522 nommu_addchr(&ctx.as_string, next);
4523 i_getch(input); /* eat second ' */
4524 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4525 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4528 ch = i_getch(input);
4530 syntax_error_unterm_ch('\'');
4533 nommu_addchr(&ctx.as_string, ch);
4536 o_addqchr(&dest, ch);
4541 dest.has_quoted_part = 1;
4542 if (next == '"' && !ctx.pending_redirect)
4543 goto insert_empty_quoted_str_marker;
4544 if (dest.o_assignment == NOT_ASSIGNMENT)
4545 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4546 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4548 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4550 #if ENABLE_HUSH_TICK
4552 USE_FOR_NOMMU(unsigned pos;)
4554 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4555 o_addchr(&dest, '`');
4556 USE_FOR_NOMMU(pos = dest.length;)
4557 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4560 o_addstr(&ctx.as_string, dest.data + pos);
4561 o_addchr(&ctx.as_string, '`');
4563 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4564 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4569 #if ENABLE_HUSH_CASE
4572 if (done_word(&dest, &ctx)) {
4575 done_pipe(&ctx, PIPE_SEQ);
4576 #if ENABLE_HUSH_CASE
4577 /* Eat multiple semicolons, detect
4578 * whether it means something special */
4583 ch = i_getch(input);
4584 nommu_addchr(&ctx.as_string, ch);
4585 if (ctx.ctx_res_w == RES_CASE_BODY) {
4586 ctx.ctx_dsemicolon = 1;
4587 ctx.ctx_res_w = RES_MATCH;
4593 /* We just finished a cmd. New one may start
4594 * with an assignment */
4595 dest.o_assignment = MAYBE_ASSIGNMENT;
4596 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4599 if (done_word(&dest, &ctx)) {
4603 ch = i_getch(input);
4604 nommu_addchr(&ctx.as_string, ch);
4605 done_pipe(&ctx, PIPE_AND);
4607 done_pipe(&ctx, PIPE_BG);
4611 if (done_word(&dest, &ctx)) {
4614 #if ENABLE_HUSH_CASE
4615 if (ctx.ctx_res_w == RES_MATCH)
4616 break; /* we are in case's "word | word)" */
4618 if (next == '|') { /* || */
4619 ch = i_getch(input);
4620 nommu_addchr(&ctx.as_string, ch);
4621 done_pipe(&ctx, PIPE_OR);
4623 /* we could pick up a file descriptor choice here
4624 * with redirect_opt_num(), but bash doesn't do it.
4625 * "echo foo 2| cat" yields "foo 2". */
4628 o_reset_to_empty_unquoted(&ctx.as_string);
4633 #if ENABLE_HUSH_CASE
4634 /* "case... in [(]word)..." - skip '(' */
4635 if (ctx.ctx_res_w == RES_MATCH
4636 && ctx.command->argv == NULL /* not (word|(... */
4637 && dest.length == 0 /* not word(... */
4638 && dest.has_quoted_part == 0 /* not ""(... */
4644 if (parse_group(&dest, &ctx, input, ch) != 0) {
4649 #if ENABLE_HUSH_CASE
4650 if (ctx.ctx_res_w == RES_MATCH)
4654 /* proper use of this character is caught by end_trigger:
4655 * if we see {, we call parse_group(..., end_trigger='}')
4656 * and it will match } earlier (not here). */
4657 syntax_error_unexpected_ch(ch);
4661 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4667 struct parse_context *pctx;
4668 IF_HAS_KEYWORDS(struct parse_context *p2;)
4670 /* Clean up allocated tree.
4671 * Sample for finding leaks on syntax error recovery path.
4672 * Run it from interactive shell, watch pmap `pidof hush`.
4673 * while if false; then false; fi; do break; fi
4674 * Samples to catch leaks at execution:
4675 * while if (true | {true;}); then echo ok; fi; do break; done
4676 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4680 /* Update pipe/command counts,
4681 * otherwise freeing may miss some */
4682 done_pipe(pctx, PIPE_SEQ);
4683 debug_printf_clean("freeing list %p from ctx %p\n",
4684 pctx->list_head, pctx);
4685 debug_print_tree(pctx->list_head, 0);
4686 free_pipe_list(pctx->list_head);
4687 debug_printf_clean("freed list %p\n", pctx->list_head);
4689 o_free_unsafe(&pctx->as_string);
4691 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4695 IF_HAS_KEYWORDS(pctx = p2;)
4696 } while (HAS_KEYWORDS && pctx);
4699 G.last_exitcode = 1;
4710 /*** Execution routines ***/
4712 /* Expansion can recurse, need forward decls: */
4713 #if !ENABLE_HUSH_BASH_COMPAT
4714 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4715 #define expand_string_to_string(str, do_unbackslash) \
4716 expand_string_to_string(str)
4718 static char *expand_string_to_string(const char *str, int do_unbackslash);
4719 #if ENABLE_HUSH_TICK
4720 static int process_command_subs(o_string *dest, const char *s);
4723 /* expand_strvec_to_strvec() takes a list of strings, expands
4724 * all variable references within and returns a pointer to
4725 * a list of expanded strings, possibly with larger number
4726 * of strings. (Think VAR="a b"; echo $VAR).
4727 * This new list is allocated as a single malloc block.
4728 * NULL-terminated list of char* pointers is at the beginning of it,
4729 * followed by strings themselves.
4730 * Caller can deallocate entire list by single free(list). */
4732 /* A horde of its helpers come first: */
4734 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4736 while (--len >= 0) {
4739 #if ENABLE_HUSH_BRACE_EXPANSION
4740 if (c == '{' || c == '}') {
4741 /* { -> \{, } -> \} */
4743 /* And now we want to add { or } and continue:
4746 * luckily, just falling throught achieves this.
4752 /* \z -> \\\z; \<eol> -> \\<eol> */
4757 o_addchr(o, *str++);
4763 /* Store given string, finalizing the word and starting new one whenever
4764 * we encounter IFS char(s). This is used for expanding variable values.
4765 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
4766 * Return in *ended_with_ifs:
4767 * 1 - ended with IFS char, else 0 (this includes case of empty str).
4769 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
4771 int last_is_ifs = 0;
4776 if (!*str) /* EOL - do not finalize word */
4778 word_len = strcspn(str, G.ifs);
4780 /* We have WORD_LEN leading non-IFS chars */
4781 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4782 o_addblock(output, str, word_len);
4784 /* Protect backslashes against globbing up :)
4785 * Example: "v='\*'; echo b$v" prints "b\*"
4786 * (and does not try to glob on "*")
4788 o_addblock_duplicate_backslash(output, str, word_len);
4789 /*/ Why can't we do it easier? */
4790 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4791 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4795 if (!*str) /* EOL - do not finalize word */
4799 /* We know str here points to at least one IFS char */
4801 str += strspn(str, G.ifs); /* skip IFS chars */
4802 if (!*str) /* EOL - do not finalize word */
4805 /* Start new word... but not always! */
4806 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
4807 if (output->has_quoted_part
4808 /* Case "v=' a'; echo $v":
4809 * here nothing precedes the space in $v expansion,
4810 * therefore we should not finish the word
4811 * (IOW: if there *is* word to finalize, only then do it):
4813 || (n > 0 && output->data[output->length - 1])
4815 o_addchr(output, '\0');
4816 debug_print_list("expand_on_ifs", output, n);
4817 n = o_save_ptr(output, n);
4822 *ended_with_ifs = last_is_ifs;
4823 debug_print_list("expand_on_ifs[1]", output, n);
4827 /* Helper to expand $((...)) and heredoc body. These act as if
4828 * they are in double quotes, with the exception that they are not :).
4829 * Just the rules are similar: "expand only $var and `cmd`"
4831 * Returns malloced string.
4832 * As an optimization, we return NULL if expansion is not needed.
4834 #if !ENABLE_HUSH_BASH_COMPAT
4835 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4836 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4837 encode_then_expand_string(str)
4839 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4842 struct in_str input;
4843 o_string dest = NULL_O_STRING;
4845 if (!strchr(str, '$')
4846 && !strchr(str, '\\')
4847 #if ENABLE_HUSH_TICK
4848 && !strchr(str, '`')
4854 /* We need to expand. Example:
4855 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4857 setup_string_in_str(&input, str);
4858 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4859 //TODO: error check (encode_string returns 0 on error)?
4860 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4861 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4862 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4863 o_free_unsafe(&dest);
4867 #if ENABLE_SH_MATH_SUPPORT
4868 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4870 arith_state_t math_state;
4874 math_state.lookupvar = get_local_var_value;
4875 math_state.setvar = set_local_var_from_halves;
4876 //math_state.endofname = endofname;
4877 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4878 res = arith(&math_state, exp_str ? exp_str : arg);
4881 *errmsg_p = math_state.errmsg;
4882 if (math_state.errmsg)
4883 die_if_script(math_state.errmsg);
4888 #if ENABLE_HUSH_BASH_COMPAT
4889 /* ${var/[/]pattern[/repl]} helpers */
4890 static char *strstr_pattern(char *val, const char *pattern, int *size)
4893 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4894 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4901 /* Optimization: if "*pat" did not match the start of "string",
4902 * we know that "tring", "ring" etc will not match too:
4904 if (pattern[0] == '*')
4909 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4911 char *result = NULL;
4912 unsigned res_len = 0;
4913 unsigned repl_len = strlen(repl);
4917 char *s = strstr_pattern(val, pattern, &size);
4921 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4922 memcpy(result + res_len, val, s - val);
4924 strcpy(result + res_len, repl);
4925 res_len += repl_len;
4926 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4932 if (val[0] && result) {
4933 result = xrealloc(result, res_len + strlen(val) + 1);
4934 strcpy(result + res_len, val);
4935 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4937 debug_printf_varexp("result:'%s'\n", result);
4943 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4945 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4947 const char *val = NULL;
4948 char *to_be_freed = NULL;
4953 char exp_save = exp_save; /* for compiler */
4954 char *exp_saveptr; /* points to expansion operator */
4955 char *exp_word = exp_word; /* for compiler */
4958 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4960 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4962 first_char = arg[0] = arg0 & 0x7f;
4965 if (first_char == '#' /* ${#... */
4966 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4968 /* It must be length operator: ${#var} */
4972 /* Maybe handle parameter expansion */
4973 if (exp_saveptr /* if 2nd char is one of expansion operators */
4974 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4976 /* ${?:0}, ${#[:]%0} etc */
4977 exp_saveptr = var + 1;
4979 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4980 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4982 exp_op = exp_save = *exp_saveptr;
4984 exp_word = exp_saveptr + 1;
4985 if (exp_op == ':') {
4986 exp_op = *exp_word++;
4987 //TODO: try ${var:} and ${var:bogus} in non-bash config
4988 if (ENABLE_HUSH_BASH_COMPAT
4989 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4991 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4996 *exp_saveptr = '\0';
4997 } /* else: it's not an expansion op, but bare ${var} */
5000 /* Look up the variable in question */
5001 if (isdigit(var[0])) {
5002 /* parse_dollar should have vetted var for us */
5003 int n = xatoi_positive(var);
5004 if (n < G.global_argc)
5005 val = G.global_argv[n];
5006 /* else val remains NULL: $N with too big N */
5010 val = utoa(G.root_pid);
5012 case '!': /* bg pid */
5013 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5015 case '?': /* exitcode */
5016 val = utoa(G.last_exitcode);
5018 case '#': /* argc */
5019 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5022 val = get_local_var_value(var);
5026 /* Handle any expansions */
5027 if (exp_op == 'L') {
5028 debug_printf_expand("expand: length(%s)=", val);
5029 val = utoa(val ? strlen(val) : 0);
5030 debug_printf_expand("%s\n", val);
5031 } else if (exp_op) {
5032 if (exp_op == '%' || exp_op == '#') {
5033 /* Standard-mandated substring removal ops:
5034 * ${parameter%word} - remove smallest suffix pattern
5035 * ${parameter%%word} - remove largest suffix pattern
5036 * ${parameter#word} - remove smallest prefix pattern
5037 * ${parameter##word} - remove largest prefix pattern
5039 * Word is expanded to produce a glob pattern.
5040 * Then var's value is matched to it and matching part removed.
5042 if (val && val[0]) {
5046 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5047 if (exp_op == *exp_word) /* ## or %% */
5049 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5051 exp_word = exp_exp_word;
5052 /* HACK ALERT. We depend here on the fact that
5053 * G.global_argv and results of utoa and get_local_var_value
5054 * are actually in writable memory:
5055 * scan_and_match momentarily stores NULs there. */
5057 loc = scan_and_match(t, exp_word, scan_flags);
5058 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5059 // exp_op, t, exp_word, loc);
5061 if (loc) { /* match was found */
5062 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5063 val = loc; /* take right part */
5065 val = to_be_freed = xstrndup(val, loc - val); /* left */
5069 #if ENABLE_HUSH_BASH_COMPAT
5070 else if (exp_op == '/' || exp_op == '\\') {
5071 /* It's ${var/[/]pattern[/repl]} thing.
5072 * Note that in encoded form it has TWO parts:
5073 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5074 * and if // is used, it is encoded as \:
5075 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5077 /* Empty variable always gives nothing: */
5078 // "v=''; echo ${v/*/w}" prints "", not "w"
5079 if (val && val[0]) {
5080 /* pattern uses non-standard expansion.
5081 * repl should be unbackslashed and globbed
5082 * by the usual expansion rules:
5084 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5085 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5086 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5087 * v='a bz'; echo ${v/a*z/\z} prints "z"
5088 * (note that a*z _pattern_ is never globbed!)
5090 char *pattern, *repl, *t;
5091 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5093 pattern = xstrdup(exp_word);
5094 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5095 *p++ = SPECIAL_VAR_SYMBOL;
5097 p = strchr(p, SPECIAL_VAR_SYMBOL);
5099 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5100 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5101 /* HACK ALERT. We depend here on the fact that
5102 * G.global_argv and results of utoa and get_local_var_value
5103 * are actually in writable memory:
5104 * replace_pattern momentarily stores NULs there. */
5106 to_be_freed = replace_pattern(t,
5108 (repl ? repl : exp_word),
5110 if (to_be_freed) /* at least one replace happened */
5117 else if (exp_op == ':') {
5118 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5119 /* It's ${var:N[:M]} bashism.
5120 * Note that in encoded form it has TWO parts:
5121 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5126 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5129 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5130 *p++ = SPECIAL_VAR_SYMBOL;
5132 p = strchr(p, SPECIAL_VAR_SYMBOL);
5134 len = expand_and_evaluate_arith(exp_word, &errmsg);
5137 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5138 if (len >= 0) { /* bash compat: len < 0 is illegal */
5139 if (beg < 0) /* bash compat */
5141 debug_printf_varexp("from val:'%s'\n", val);
5142 if (len == 0 || !val || beg >= strlen(val)) {
5146 /* Paranoia. What if user entered 9999999999999
5147 * which fits in arith_t but not int? */
5150 val = to_be_freed = xstrndup(val + beg, len);
5152 debug_printf_varexp("val:'%s'\n", val);
5156 die_if_script("malformed ${%s:...}", var);
5159 } else { /* one of "-=+?" */
5160 /* Standard-mandated substitution ops:
5161 * ${var?word} - indicate error if unset
5162 * If var is unset, word (or a message indicating it is unset
5163 * if word is null) is written to standard error
5164 * and the shell exits with a non-zero exit status.
5165 * Otherwise, the value of var is substituted.
5166 * ${var-word} - use default value
5167 * If var is unset, word is substituted.
5168 * ${var=word} - assign and use default value
5169 * If var is unset, word is assigned to var.
5170 * In all cases, final value of var is substituted.
5171 * ${var+word} - use alternative value
5172 * If var is unset, null is substituted.
5173 * Otherwise, word is substituted.
5175 * Word is subjected to tilde expansion, parameter expansion,
5176 * command substitution, and arithmetic expansion.
5177 * If word is not needed, it is not expanded.
5179 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5180 * but also treat null var as if it is unset.
5182 int use_word = (!val || ((exp_save == ':') && !val[0]));
5184 use_word = !use_word;
5185 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5186 (exp_save == ':') ? "true" : "false", use_word);
5188 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5190 exp_word = to_be_freed;
5191 if (exp_op == '?') {
5192 /* mimic bash message */
5193 die_if_script("%s: %s",
5195 exp_word[0] ? exp_word : "parameter null or not set"
5197 //TODO: how interactive bash aborts expansion mid-command?
5202 if (exp_op == '=') {
5203 /* ${var=[word]} or ${var:=[word]} */
5204 if (isdigit(var[0]) || var[0] == '#') {
5205 /* mimic bash message */
5206 die_if_script("$%s: cannot assign in this way", var);
5209 char *new_var = xasprintf("%s=%s", var, val);
5210 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5214 } /* one of "-=+?" */
5216 *exp_saveptr = exp_save;
5222 *to_be_freed_pp = to_be_freed;
5226 /* Expand all variable references in given string, adding words to list[]
5227 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5228 * to be filled). This routine is extremely tricky: has to deal with
5229 * variables/parameters with whitespace, $* and $@, and constructs like
5230 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5231 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5233 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5234 * expansion of right-hand side of assignment == 1-element expand.
5236 char cant_be_null = 0; /* only bit 0x80 matters */
5237 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5240 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5241 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5242 debug_print_list("expand_vars_to_list", output, n);
5243 n = o_save_ptr(output, n);
5244 debug_print_list("expand_vars_to_list[0]", output, n);
5246 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5248 char *to_be_freed = NULL;
5249 const char *val = NULL;
5250 #if ENABLE_HUSH_TICK
5251 o_string subst_result = NULL_O_STRING;
5253 #if ENABLE_SH_MATH_SUPPORT
5254 char arith_buf[sizeof(arith_t)*3 + 2];
5258 o_addchr(output, '\0');
5259 n = o_save_ptr(output, n);
5263 o_addblock(output, arg, p - arg);
5264 debug_print_list("expand_vars_to_list[1]", output, n);
5266 p = strchr(p, SPECIAL_VAR_SYMBOL);
5268 /* Fetch special var name (if it is indeed one of them)
5269 * and quote bit, force the bit on if singleword expansion -
5270 * important for not getting v=$@ expand to many words. */
5271 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5273 /* Is this variable quoted and thus expansion can't be null?
5274 * "$@" is special. Even if quoted, it can still
5275 * expand to nothing (not even an empty string),
5276 * thus it is excluded. */
5277 if ((first_ch & 0x7f) != '@')
5278 cant_be_null |= first_ch;
5280 switch (first_ch & 0x7f) {
5281 /* Highest bit in first_ch indicates that var is double-quoted */
5285 if (!G.global_argv[1])
5288 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5289 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5290 while (G.global_argv[i]) {
5291 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5292 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5293 if (G.global_argv[i++][0] && G.global_argv[i]) {
5294 /* this argv[] is not empty and not last:
5295 * put terminating NUL, start new word */
5296 o_addchr(output, '\0');
5297 debug_print_list("expand_vars_to_list[2]", output, n);
5298 n = o_save_ptr(output, n);
5299 debug_print_list("expand_vars_to_list[3]", output, n);
5303 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5304 * and in this case should treat it like '$*' - see 'else...' below */
5305 if (first_ch == ('@'|0x80) /* quoted $@ */
5306 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5309 o_addQstr(output, G.global_argv[i]);
5310 if (++i >= G.global_argc)
5312 o_addchr(output, '\0');
5313 debug_print_list("expand_vars_to_list[4]", output, n);
5314 n = o_save_ptr(output, n);
5316 } else { /* quoted $* (or v="$@" case): add as one word */
5318 o_addQstr(output, G.global_argv[i]);
5319 if (!G.global_argv[++i])
5322 o_addchr(output, G.ifs[0]);
5324 output->has_quoted_part = 1;
5328 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5329 /* "Empty variable", used to make "" etc to not disappear */
5330 output->has_quoted_part = 1;
5332 cant_be_null = 0x80;
5334 #if ENABLE_HUSH_TICK
5335 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5336 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5338 /* Can't just stuff it into output o_string,
5339 * expanded result may need to be globbed
5340 * and $IFS-splitted */
5341 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5342 G.last_exitcode = process_command_subs(&subst_result, arg);
5343 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5344 val = subst_result.data;
5347 #if ENABLE_SH_MATH_SUPPORT
5348 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5351 arg++; /* skip '+' */
5352 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5353 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5354 res = expand_and_evaluate_arith(arg, NULL);
5355 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5356 sprintf(arith_buf, ARITH_FMT, res);
5362 val = expand_one_var(&to_be_freed, arg, &p);
5363 IF_HUSH_TICK(store_val:)
5364 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5365 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5366 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5367 if (val && val[0]) {
5368 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5371 } else { /* quoted $VAR, val will be appended below */
5372 output->has_quoted_part = 1;
5373 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5374 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5378 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5380 if (val && val[0]) {
5381 o_addQstr(output, val);
5385 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5386 * Do the check to avoid writing to a const string. */
5387 if (*p != SPECIAL_VAR_SYMBOL)
5388 *p = SPECIAL_VAR_SYMBOL;
5390 #if ENABLE_HUSH_TICK
5391 o_free(&subst_result);
5394 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5398 o_addchr(output, '\0');
5399 n = o_save_ptr(output, n);
5401 debug_print_list("expand_vars_to_list[a]", output, n);
5402 /* this part is literal, and it was already pre-quoted
5403 * if needed (much earlier), do not use o_addQstr here! */
5404 o_addstr_with_NUL(output, arg);
5405 debug_print_list("expand_vars_to_list[b]", output, n);
5406 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5407 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5410 /* allow to reuse list[n] later without re-growth */
5411 output->has_empty_slot = 1;
5413 o_addchr(output, '\0');
5419 static char **expand_variables(char **argv, unsigned expflags)
5423 o_string output = NULL_O_STRING;
5425 output.o_expflags = expflags;
5429 n = expand_vars_to_list(&output, n, *argv);
5432 debug_print_list("expand_variables", &output, n);
5434 /* output.data (malloced in one block) gets returned in "list" */
5435 list = o_finalize_list(&output, n);
5436 debug_print_strings("expand_variables[1]", list);
5440 static char **expand_strvec_to_strvec(char **argv)
5442 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5445 #if ENABLE_HUSH_BASH_COMPAT
5446 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5448 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5452 /* Used for expansion of right hand of assignments,
5453 * $((...)), heredocs, variable espansion parts.
5455 * NB: should NOT do globbing!
5456 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5458 static char *expand_string_to_string(const char *str, int do_unbackslash)
5460 #if !ENABLE_HUSH_BASH_COMPAT
5461 const int do_unbackslash = 1;
5463 char *argv[2], **list;
5465 debug_printf_expand("string_to_string<='%s'\n", str);
5466 /* This is generally an optimization, but it also
5467 * handles "", which otherwise trips over !list[0] check below.
5468 * (is this ever happens that we actually get str="" here?)
5470 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5471 //TODO: Can use on strings with \ too, just unbackslash() them?
5472 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5473 return xstrdup(str);
5476 argv[0] = (char*)str;
5478 list = expand_variables(argv, do_unbackslash
5479 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5480 : EXP_FLAG_SINGLEWORD
5483 if (!list[0] || list[1])
5484 bb_error_msg_and_die("BUG in varexp2");
5485 /* actually, just move string 2*sizeof(char*) bytes back */
5486 overlapping_strcpy((char*)list, list[0]);
5488 unbackslash((char*)list);
5489 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5493 /* Used for "eval" builtin */
5494 static char* expand_strvec_to_string(char **argv)
5498 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5499 /* Convert all NULs to spaces */
5504 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5505 bb_error_msg_and_die("BUG in varexp3");
5506 /* bash uses ' ' regardless of $IFS contents */
5511 overlapping_strcpy((char*)list, list[0]);
5512 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5516 static char **expand_assignments(char **argv, int count)
5521 G.expanded_assignments = p = NULL;
5522 /* Expand assignments into one string each */
5523 for (i = 0; i < count; i++) {
5524 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5526 G.expanded_assignments = NULL;
5531 static void switch_off_special_sigs(unsigned mask)
5534 while ((mask >>= 1) != 0) {
5539 if (G.traps[sig] && !G.traps[sig][0])
5540 /* trap is '', has to remain SIG_IGN */
5543 G.traps[sig] = NULL;
5545 /* We are here only if no trap or trap was not '' */
5546 install_sighandler(sig, SIG_DFL);
5552 void re_execute_shell(char ***to_free, const char *s,
5553 char *g_argv0, char **g_argv,
5554 char **builtin_argv) NORETURN;
5556 static void reset_traps_to_defaults(void)
5558 /* This function is always called in a child shell
5559 * after fork (not vfork, NOMMU doesn't use this function).
5564 /* Child shells are not interactive.
5565 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5566 * Testcase: (while :; do :; done) + ^Z should background.
5567 * Same goes for SIGTERM, SIGHUP, SIGINT.
5569 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5570 if (!G.traps && !mask)
5571 return; /* already no traps and no special sigs */
5573 /* Switch off special sigs */
5574 switch_off_special_sigs(mask);
5576 G_fatal_sig_mask = 0;
5578 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5579 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5580 * remain set in G.special_sig_mask */
5585 /* Reset all sigs to default except ones with empty traps */
5586 for (sig = 0; sig < NSIG; sig++) {
5588 continue; /* no trap: nothing to do */
5589 if (!G.traps[sig][0])
5590 continue; /* empty trap: has to remain SIG_IGN */
5591 /* sig has non-empty trap, reset it: */
5593 G.traps[sig] = NULL;
5594 /* There is no signal for trap 0 (EXIT) */
5597 install_sighandler(sig, pick_sighandler(sig));
5603 static void re_execute_shell(char ***to_free, const char *s,
5604 char *g_argv0, char **g_argv,
5605 char **builtin_argv) NORETURN;
5606 static void re_execute_shell(char ***to_free, const char *s,
5607 char *g_argv0, char **g_argv,
5608 char **builtin_argv)
5610 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5611 /* delims + 2 * (number of bytes in printed hex numbers) */
5612 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5613 char *heredoc_argv[4];
5614 struct variable *cur;
5615 # if ENABLE_HUSH_FUNCTIONS
5616 struct function *funcp;
5620 unsigned long long empty_trap_mask;
5622 if (!g_argv0) { /* heredoc */
5623 argv = heredoc_argv;
5624 argv[0] = (char *) G.argv0_for_re_execing;
5625 argv[1] = (char *) "-<";
5626 argv[2] = (char *) s;
5628 pp = &argv[3]; /* used as pointer to empty environment */
5634 if (pp) while (*pp++)
5637 empty_trap_mask = 0;
5640 for (sig = 1; sig < NSIG; sig++) {
5641 if (G.traps[sig] && !G.traps[sig][0])
5642 empty_trap_mask |= 1LL << sig;
5646 sprintf(param_buf, NOMMU_HACK_FMT
5647 , (unsigned) G.root_pid
5648 , (unsigned) G.root_ppid
5649 , (unsigned) G.last_bg_pid
5650 , (unsigned) G.last_exitcode
5653 IF_HUSH_LOOPS(, G.depth_of_loop)
5655 # undef NOMMU_HACK_FMT
5656 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5657 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5660 for (cur = G.top_var; cur; cur = cur->next) {
5661 if (!cur->flg_export || cur->flg_read_only)
5664 # if ENABLE_HUSH_FUNCTIONS
5665 for (funcp = G.top_func; funcp; funcp = funcp->next)
5671 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5672 *pp++ = (char *) G.argv0_for_re_execing;
5674 for (cur = G.top_var; cur; cur = cur->next) {
5675 if (strcmp(cur->varstr, hush_version_str) == 0)
5677 if (cur->flg_read_only) {
5678 *pp++ = (char *) "-R";
5679 *pp++ = cur->varstr;
5680 } else if (!cur->flg_export) {
5681 *pp++ = (char *) "-V";
5682 *pp++ = cur->varstr;
5685 # if ENABLE_HUSH_FUNCTIONS
5686 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5687 *pp++ = (char *) "-F";
5688 *pp++ = funcp->name;
5689 *pp++ = funcp->body_as_string;
5692 /* We can pass activated traps here. Say, -Tnn:trap_string
5694 * However, POSIX says that subshells reset signals with traps
5696 * I tested bash-3.2 and it not only does that with true subshells
5697 * of the form ( list ), but with any forked children shells.
5698 * I set trap "echo W" WINCH; and then tried:
5700 * { echo 1; sleep 20; echo 2; } &
5701 * while true; do echo 1; sleep 20; echo 2; break; done &
5702 * true | { echo 1; sleep 20; echo 2; } | cat
5704 * In all these cases sending SIGWINCH to the child shell
5705 * did not run the trap. If I add trap "echo V" WINCH;
5706 * _inside_ group (just before echo 1), it works.
5708 * I conclude it means we don't need to pass active traps here.
5710 *pp++ = (char *) "-c";
5713 while (*++builtin_argv)
5714 *pp++ = *builtin_argv;
5715 *pp++ = (char *) "";
5720 /* *pp = NULL; - is already there */
5724 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5725 /* Don't propagate SIG_IGN to the child */
5726 if (SPECIAL_JOBSTOP_SIGS != 0)
5727 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
5728 execve(bb_busybox_exec_path, argv, pp);
5729 /* Fallback. Useful for init=/bin/hush usage etc */
5730 if (argv[0][0] == '/')
5731 execve(argv[0], argv, pp);
5732 xfunc_error_retval = 127;
5733 bb_error_msg_and_die("can't re-execute the shell");
5735 #endif /* !BB_MMU */
5738 static int run_and_free_list(struct pipe *pi);
5740 /* Executing from string: eval, sh -c '...'
5741 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5742 * end_trigger controls how often we stop parsing
5743 * NUL: parse all, execute, return
5744 * ';': parse till ';' or newline, execute, repeat till EOF
5746 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5748 /* Why we need empty flag?
5749 * An obscure corner case "false; ``; echo $?":
5750 * empty command in `` should still set $? to 0.
5751 * But we can't just set $? to 0 at the start,
5752 * this breaks "false; echo `echo $?`" case.
5756 struct pipe *pipe_list;
5758 #if ENABLE_HUSH_INTERACTIVE
5759 if (end_trigger == ';')
5760 inp->promptmode = 0; /* PS1 */
5762 pipe_list = parse_stream(NULL, inp, end_trigger);
5763 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
5764 /* If we are in "big" script
5765 * (not in `cmd` or something similar)...
5767 if (pipe_list == ERR_PTR && end_trigger == ';') {
5768 /* Discard cached input (rest of line) */
5769 int ch = inp->last_char;
5770 while (ch != EOF && ch != '\n') {
5771 //bb_error_msg("Discarded:'%c'", ch);
5776 /* This stream isn't empty */
5780 if (!pipe_list && empty)
5781 G.last_exitcode = 0;
5784 debug_print_tree(pipe_list, 0);
5785 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5786 run_and_free_list(pipe_list);
5788 #if ENABLE_HUSH_FUNCTIONS
5789 if (G.flag_return_in_progress == 1)
5795 static void parse_and_run_string(const char *s)
5797 struct in_str input;
5798 setup_string_in_str(&input, s);
5799 parse_and_run_stream(&input, '\0');
5802 static void parse_and_run_file(FILE *f)
5804 struct in_str input;
5805 setup_file_in_str(&input, f);
5806 parse_and_run_stream(&input, ';');
5809 #if ENABLE_HUSH_TICK
5810 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5815 char **to_free = NULL;
5819 pid = BB_MMU ? xfork() : xvfork();
5820 if (pid == 0) { /* child */
5821 disable_restore_tty_pgrp_on_exit();
5822 /* Process substitution is not considered to be usual
5823 * 'command execution'.
5824 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5831 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5832 close(channel[0]); /* NB: close _first_, then move fd! */
5833 xmove_fd(channel[1], 1);
5834 /* Prevent it from trying to handle ctrl-z etc */
5835 IF_HUSH_JOB(G.run_list_level = 1;)
5836 /* Awful hack for `trap` or $(trap).
5838 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5839 * contains an example where "trap" is executed in a subshell:
5841 * save_traps=$(trap)
5843 * eval "$save_traps"
5845 * Standard does not say that "trap" in subshell shall print
5846 * parent shell's traps. It only says that its output
5847 * must have suitable form, but then, in the above example
5848 * (which is not supposed to be normative), it implies that.
5850 * bash (and probably other shell) does implement it
5851 * (traps are reset to defaults, but "trap" still shows them),
5852 * but as a result, "trap" logic is hopelessly messed up:
5855 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5856 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5857 * # true | trap <--- trap is in subshell - no output (ditto)
5858 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5859 * trap -- 'echo Ho' SIGWINCH
5860 * # echo `(trap)` <--- in subshell in subshell - output
5861 * trap -- 'echo Ho' SIGWINCH
5862 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5863 * trap -- 'echo Ho' SIGWINCH
5865 * The rules when to forget and when to not forget traps
5866 * get really complex and nonsensical.
5868 * Our solution: ONLY bare $(trap) or `trap` is special.
5870 s = skip_whitespace(s);
5871 if (strncmp(s, "trap", 4) == 0
5872 && skip_whitespace(s + 4)[0] == '\0'
5874 static const char *const argv[] = { NULL, NULL };
5875 builtin_trap((char**)argv);
5876 exit(0); /* not _exit() - we need to fflush */
5879 reset_traps_to_defaults();
5880 parse_and_run_string(s);
5881 _exit(G.last_exitcode);
5883 /* We re-execute after vfork on NOMMU. This makes this script safe:
5884 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5885 * huge=`cat BIG` # was blocking here forever
5888 re_execute_shell(&to_free,
5898 # if ENABLE_HUSH_FAST
5900 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5901 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5902 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5904 enable_restore_tty_pgrp_on_exit();
5909 close_on_exec_on(channel[0]);
5910 return xfdopen_for_read(channel[0]);
5913 /* Return code is exit status of the process that is run. */
5914 static int process_command_subs(o_string *dest, const char *s)
5917 struct in_str pipe_str;
5919 int status, ch, eol_cnt;
5921 fp = generate_stream_from_string(s, &pid);
5923 /* Now send results of command back into original context */
5924 setup_file_in_str(&pipe_str, fp);
5926 while ((ch = i_getch(&pipe_str)) != EOF) {
5932 o_addchr(dest, '\n');
5935 o_addQchr(dest, ch);
5938 debug_printf("done reading from `cmd` pipe, closing it\n");
5940 /* We need to extract exitcode. Test case
5941 * "true; echo `sleep 1; false` $?"
5943 safe_waitpid(pid, &status, 0);
5944 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5945 return WEXITSTATUS(status);
5947 #endif /* ENABLE_HUSH_TICK */
5950 static void setup_heredoc(struct redir_struct *redir)
5952 struct fd_pair pair;
5955 /* the _body_ of heredoc (misleading field name) */
5956 const char *heredoc = redir->rd_filename;
5963 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5964 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5968 len = strlen(heredoc);
5970 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5972 xmove_fd(pair.rd, redir->rd_fd);
5974 /* Try writing without forking. Newer kernels have
5975 * dynamically growing pipes. Must use non-blocking write! */
5978 written = write(pair.wr, heredoc, len);
5989 ndelay_off(pair.wr);
5991 /* Okay, pipe buffer was not big enough */
5992 /* Note: we must not create a stray child (bastard? :)
5993 * for the unsuspecting parent process. Child creates a grandchild
5994 * and exits before parent execs the process which consumes heredoc
5995 * (that exec happens after we return from this function) */
6002 disable_restore_tty_pgrp_on_exit();
6003 pid = BB_MMU ? xfork() : xvfork();
6007 close(redir->rd_fd); /* read side of the pipe */
6009 full_write(pair.wr, heredoc, len); /* may loop or block */
6012 /* Delegate blocking writes to another process */
6013 xmove_fd(pair.wr, STDOUT_FILENO);
6014 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6018 #if ENABLE_HUSH_FAST
6020 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6022 enable_restore_tty_pgrp_on_exit();
6028 wait(NULL); /* wait till child has died */
6031 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6032 * and stderr if they are redirected. */
6033 static int setup_redirects(struct command *prog, int squirrel[])
6036 struct redir_struct *redir;
6038 for (redir = prog->redirects; redir; redir = redir->next) {
6039 if (redir->rd_type == REDIRECT_HEREDOC2) {
6040 /* rd_fd<<HERE case */
6041 if (squirrel && redir->rd_fd < 3
6042 && squirrel[redir->rd_fd] < 0
6044 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6046 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6048 debug_printf_parse("set heredoc '%s'\n",
6049 redir->rd_filename);
6050 setup_heredoc(redir);
6054 if (redir->rd_dup == REDIRFD_TO_FILE) {
6055 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
6057 if (redir->rd_filename == NULL) {
6058 /* Something went wrong in the parse.
6059 * Pretend it didn't happen */
6060 bb_error_msg("bug in redirect parse");
6063 mode = redir_table[redir->rd_type].mode;
6064 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6065 openfd = open_or_warn(p, mode);
6068 /* this could get lost if stderr has been redirected, but
6069 * bash and ash both lose it as well (though zsh doesn't!) */
6070 //what the above comment tries to say?
6074 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
6075 openfd = redir->rd_dup;
6078 if (openfd != redir->rd_fd) {
6079 if (squirrel && redir->rd_fd < 3
6080 && squirrel[redir->rd_fd] < 0
6082 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6084 if (openfd == REDIRFD_CLOSE) {
6085 /* "n>-" means "close me" */
6086 close(redir->rd_fd);
6088 xdup2(openfd, redir->rd_fd);
6089 if (redir->rd_dup == REDIRFD_TO_FILE)
6097 static void restore_redirects(int squirrel[])
6100 for (i = 0; i < 3; i++) {
6103 /* We simply die on error */
6109 static char *find_in_path(const char *arg)
6112 const char *PATH = get_local_var_value("PATH");
6118 const char *end = strchrnul(PATH, ':');
6119 int sz = end - PATH; /* must be int! */
6123 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6125 /* We have xxx::yyyy in $PATH,
6126 * it means "use current dir" */
6129 if (access(ret, F_OK) == 0)
6142 static const struct built_in_command *find_builtin_helper(const char *name,
6143 const struct built_in_command *x,
6144 const struct built_in_command *end)
6147 if (strcmp(name, x->b_cmd) != 0) {
6151 debug_printf_exec("found builtin '%s'\n", name);
6156 static const struct built_in_command *find_builtin1(const char *name)
6158 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6160 static const struct built_in_command *find_builtin(const char *name)
6162 const struct built_in_command *x = find_builtin1(name);
6165 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6168 #if ENABLE_HUSH_FUNCTIONS
6169 static struct function **find_function_slot(const char *name)
6171 struct function **funcpp = &G.top_func;
6173 if (strcmp(name, (*funcpp)->name) == 0) {
6176 funcpp = &(*funcpp)->next;
6181 static const struct function *find_function(const char *name)
6183 const struct function *funcp = *find_function_slot(name);
6185 debug_printf_exec("found function '%s'\n", name);
6189 /* Note: takes ownership on name ptr */
6190 static struct function *new_function(char *name)
6192 struct function **funcpp = find_function_slot(name);
6193 struct function *funcp = *funcpp;
6195 if (funcp != NULL) {
6196 struct command *cmd = funcp->parent_cmd;
6197 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6199 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6201 /* Note: if !funcp->body, do not free body_as_string!
6202 * This is a special case of "-F name body" function:
6203 * body_as_string was not malloced! */
6205 free_pipe_list(funcp->body);
6207 free(funcp->body_as_string);
6211 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6212 cmd->argv[0] = funcp->name;
6213 cmd->group = funcp->body;
6215 cmd->group_as_string = funcp->body_as_string;
6219 debug_printf_exec("remembering new function '%s'\n", name);
6220 funcp = *funcpp = xzalloc(sizeof(*funcp));
6221 /*funcp->next = NULL;*/
6228 static void unset_func(const char *name)
6230 struct function **funcpp = find_function_slot(name);
6231 struct function *funcp = *funcpp;
6233 if (funcp != NULL) {
6234 debug_printf_exec("freeing function '%s'\n", funcp->name);
6235 *funcpp = funcp->next;
6236 /* funcp is unlinked now, deleting it.
6237 * Note: if !funcp->body, the function was created by
6238 * "-F name body", do not free ->body_as_string
6239 * and ->name as they were not malloced. */
6241 free_pipe_list(funcp->body);
6244 free(funcp->body_as_string);
6252 #define exec_function(to_free, funcp, argv) \
6253 exec_function(funcp, argv)
6255 static void exec_function(char ***to_free,
6256 const struct function *funcp,
6257 char **argv) NORETURN;
6258 static void exec_function(char ***to_free,
6259 const struct function *funcp,
6265 argv[0] = G.global_argv[0];
6266 G.global_argv = argv;
6270 /* On MMU, funcp->body is always non-NULL */
6271 n = run_list(funcp->body);
6275 re_execute_shell(to_free,
6276 funcp->body_as_string,
6283 static int run_function(const struct function *funcp, char **argv)
6289 save_and_replace_G_args(&sv, argv);
6291 /* "we are in function, ok to use return" */
6292 sv_flg = G.flag_return_in_progress;
6293 G.flag_return_in_progress = -1;
6294 # if ENABLE_HUSH_LOCAL
6295 G.func_nest_level++;
6298 /* On MMU, funcp->body is always non-NULL */
6301 /* Function defined by -F */
6302 parse_and_run_string(funcp->body_as_string);
6303 rc = G.last_exitcode;
6307 rc = run_list(funcp->body);
6310 # if ENABLE_HUSH_LOCAL
6312 struct variable *var;
6313 struct variable **var_pp;
6315 var_pp = &G.top_var;
6316 while ((var = *var_pp) != NULL) {
6317 if (var->func_nest_level < G.func_nest_level) {
6318 var_pp = &var->next;
6322 if (var->flg_export)
6323 bb_unsetenv(var->varstr);
6324 /* Remove from global list */
6325 *var_pp = var->next;
6331 G.func_nest_level--;
6334 G.flag_return_in_progress = sv_flg;
6336 restore_G_args(&sv, argv);
6340 #endif /* ENABLE_HUSH_FUNCTIONS */
6344 #define exec_builtin(to_free, x, argv) \
6345 exec_builtin(x, argv)
6347 #define exec_builtin(to_free, x, argv) \
6348 exec_builtin(to_free, argv)
6350 static void exec_builtin(char ***to_free,
6351 const struct built_in_command *x,
6352 char **argv) NORETURN;
6353 static void exec_builtin(char ***to_free,
6354 const struct built_in_command *x,
6360 rcode = x->b_function(argv);
6365 /* On NOMMU, we must never block!
6366 * Example: { sleep 99 | read line; } & echo Ok
6368 re_execute_shell(to_free,
6377 static void execvp_or_die(char **argv) NORETURN;
6378 static void execvp_or_die(char **argv)
6380 debug_printf_exec("execing '%s'\n", argv[0]);
6381 /* Don't propagate SIG_IGN to the child */
6382 if (SPECIAL_JOBSTOP_SIGS != 0)
6383 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6384 execvp(argv[0], argv);
6385 bb_perror_msg("can't execute '%s'", argv[0]);
6386 _exit(127); /* bash compat */
6389 #if ENABLE_HUSH_MODE_X
6390 static void dump_cmd_in_x_mode(char **argv)
6392 if (G_x_mode && argv) {
6393 /* We want to output the line in one write op */
6401 len += strlen(argv[n++]) + 1;
6407 p += sprintf(p, " %s", argv[n++]);
6415 # define dump_cmd_in_x_mode(argv) ((void)0)
6419 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6420 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6421 #define pseudo_exec(nommu_save, command, argv_expanded) \
6422 pseudo_exec(command, argv_expanded)
6425 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6427 * Don't exit() here. If you don't exec, use _exit instead.
6428 * The at_exit handlers apparently confuse the calling process,
6429 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6430 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6431 char **argv, int assignment_cnt,
6432 char **argv_expanded) NORETURN;
6433 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6434 char **argv, int assignment_cnt,
6435 char **argv_expanded)
6439 new_env = expand_assignments(argv, assignment_cnt);
6440 dump_cmd_in_x_mode(new_env);
6442 if (!argv[assignment_cnt]) {
6443 /* Case when we are here: ... | var=val | ...
6444 * (note that we do not exit early, i.e., do not optimize out
6445 * expand_assignments(): think about ... | var=`sleep 1` | ...
6447 free_strings(new_env);
6448 _exit(EXIT_SUCCESS);
6452 set_vars_and_save_old(new_env);
6453 free(new_env); /* optional */
6454 /* we can also destroy set_vars_and_save_old's return value,
6457 nommu_save->new_env = new_env;
6458 nommu_save->old_vars = set_vars_and_save_old(new_env);
6461 if (argv_expanded) {
6462 argv = argv_expanded;
6464 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6466 nommu_save->argv = argv;
6469 dump_cmd_in_x_mode(argv);
6471 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6472 if (strchr(argv[0], '/') != NULL)
6476 /* Check if the command matches any of the builtins.
6477 * Depending on context, this might be redundant. But it's
6478 * easier to waste a few CPU cycles than it is to figure out
6479 * if this is one of those cases.
6482 /* On NOMMU, it is more expensive to re-execute shell
6483 * just in order to run echo or test builtin.
6484 * It's better to skip it here and run corresponding
6485 * non-builtin later. */
6486 const struct built_in_command *x;
6487 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6489 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6492 #if ENABLE_HUSH_FUNCTIONS
6493 /* Check if the command matches any functions */
6495 const struct function *funcp = find_function(argv[0]);
6497 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6502 #if ENABLE_FEATURE_SH_STANDALONE
6503 /* Check if the command matches any busybox applets */
6505 int a = find_applet_by_name(argv[0]);
6507 # if BB_MMU /* see above why on NOMMU it is not allowed */
6508 if (APPLET_IS_NOEXEC(a)) {
6509 debug_printf_exec("running applet '%s'\n", argv[0]);
6510 run_applet_no_and_exit(a, argv);
6513 /* Re-exec ourselves */
6514 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6515 /* Don't propagate SIG_IGN to the child */
6516 if (SPECIAL_JOBSTOP_SIGS != 0)
6517 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6518 execv(bb_busybox_exec_path, argv);
6519 /* If they called chroot or otherwise made the binary no longer
6520 * executable, fall through */
6525 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6528 execvp_or_die(argv);
6531 /* Called after [v]fork() in run_pipe
6533 static void pseudo_exec(nommu_save_t *nommu_save,
6534 struct command *command,
6535 char **argv_expanded) NORETURN;
6536 static void pseudo_exec(nommu_save_t *nommu_save,
6537 struct command *command,
6538 char **argv_expanded)
6540 if (command->argv) {
6541 pseudo_exec_argv(nommu_save, command->argv,
6542 command->assignment_cnt, argv_expanded);
6545 if (command->group) {
6546 /* Cases when we are here:
6549 * ... | ( list ) | ...
6550 * ... | { list } | ...
6554 debug_printf_exec("pseudo_exec: run_list\n");
6555 reset_traps_to_defaults();
6556 rcode = run_list(command->group);
6557 /* OK to leak memory by not calling free_pipe_list,
6558 * since this process is about to exit */
6561 re_execute_shell(&nommu_save->argv_from_re_execing,
6562 command->group_as_string,
6569 /* Case when we are here: ... | >file */
6570 debug_printf_exec("pseudo_exec'ed null command\n");
6571 _exit(EXIT_SUCCESS);
6575 static const char *get_cmdtext(struct pipe *pi)
6581 /* This is subtle. ->cmdtext is created only on first backgrounding.
6582 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6583 * On subsequent bg argv is trashed, but we won't use it */
6586 argv = pi->cmds[0].argv;
6587 if (!argv || !argv[0]) {
6588 pi->cmdtext = xzalloc(1);
6594 len += strlen(*argv) + 1;
6598 argv = pi->cmds[0].argv;
6600 len = strlen(*argv);
6601 memcpy(p, *argv, len);
6609 static void insert_bg_job(struct pipe *pi)
6611 struct pipe *job, **jobp;
6614 /* Linear search for the ID of the job to use */
6616 for (job = G.job_list; job; job = job->next)
6617 if (job->jobid >= pi->jobid)
6618 pi->jobid = job->jobid + 1;
6620 /* Add job to the list of running jobs */
6622 while ((job = *jobp) != NULL)
6624 job = *jobp = xmalloc(sizeof(*job));
6626 *job = *pi; /* physical copy */
6628 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6629 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6630 for (i = 0; i < pi->num_cmds; i++) {
6631 job->cmds[i].pid = pi->cmds[i].pid;
6632 /* all other fields are not used and stay zero */
6634 job->cmdtext = xstrdup(get_cmdtext(pi));
6636 if (G_interactive_fd)
6637 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6638 G.last_jobid = job->jobid;
6641 static void remove_bg_job(struct pipe *pi)
6643 struct pipe *prev_pipe;
6645 if (pi == G.job_list) {
6646 G.job_list = pi->next;
6648 prev_pipe = G.job_list;
6649 while (prev_pipe->next != pi)
6650 prev_pipe = prev_pipe->next;
6651 prev_pipe->next = pi->next;
6654 G.last_jobid = G.job_list->jobid;
6659 /* Remove a backgrounded job */
6660 static void delete_finished_bg_job(struct pipe *pi)
6667 /* Check to see if any processes have exited -- if they
6668 * have, figure out why and see if a job has completed */
6669 static int checkjobs(struct pipe *fg_pipe)
6679 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6681 attributes = WUNTRACED;
6682 if (fg_pipe == NULL)
6683 attributes |= WNOHANG;
6686 #if ENABLE_HUSH_FAST
6687 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6688 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6689 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6690 /* There was neither fork nor SIGCHLD since last waitpid */
6691 /* Avoid doing waitpid syscall if possible */
6692 if (!G.we_have_children) {
6696 if (fg_pipe == NULL) { /* is WNOHANG set? */
6697 /* We have children, but they did not exit
6698 * or stop yet (we saw no SIGCHLD) */
6701 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6705 /* Do we do this right?
6706 * bash-3.00# sleep 20 | false
6708 * [3]+ Stopped sleep 20 | false
6709 * bash-3.00# echo $?
6710 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6711 * [hush 1.14.0: yes we do it right]
6718 #if ENABLE_HUSH_FAST
6719 i = G.count_SIGCHLD;
6721 childpid = waitpid(-1, &status, attributes);
6722 if (childpid <= 0) {
6723 if (childpid && errno != ECHILD)
6724 bb_perror_msg("waitpid");
6725 #if ENABLE_HUSH_FAST
6726 else { /* Until next SIGCHLD, waitpid's are useless */
6727 G.we_have_children = (childpid == 0);
6728 G.handled_SIGCHLD = i;
6729 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6734 dead = WIFEXITED(status) || WIFSIGNALED(status);
6737 if (WIFSTOPPED(status))
6738 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6739 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6740 if (WIFSIGNALED(status))
6741 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6742 childpid, WTERMSIG(status), WEXITSTATUS(status));
6743 if (WIFEXITED(status))
6744 debug_printf_jobs("pid %d exited, exitcode %d\n",
6745 childpid, WEXITSTATUS(status));
6747 /* Were we asked to wait for fg pipe? */
6749 i = fg_pipe->num_cmds;
6751 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6752 if (fg_pipe->cmds[i].pid != childpid)
6756 fg_pipe->cmds[i].pid = 0;
6757 fg_pipe->alive_cmds--;
6758 ex = WEXITSTATUS(status);
6759 /* bash prints killer signal's name for *last*
6760 * process in pipe (prints just newline for SIGINT/SIGPIPE).
6761 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6763 if (WIFSIGNALED(status)) {
6764 int sig = WTERMSIG(status);
6765 if (i == fg_pipe->num_cmds-1)
6766 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
6767 printf("%s\n", sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
6768 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
6769 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6770 * Maybe we need to use sig | 128? */
6773 fg_pipe->cmds[i].cmd_exitcode = ex;
6775 fg_pipe->stopped_cmds++;
6777 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6778 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6779 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6780 /* All processes in fg pipe have exited or stopped */
6781 i = fg_pipe->num_cmds;
6783 rcode = fg_pipe->cmds[i].cmd_exitcode;
6784 /* usually last process gives overall exitstatus,
6785 * but with "set -o pipefail", last *failed* process does */
6786 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6789 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6790 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6791 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6792 * and "killall -STOP cat" */
6793 if (G_interactive_fd) {
6795 if (fg_pipe->alive_cmds != 0)
6796 insert_bg_job(fg_pipe);
6800 if (fg_pipe->alive_cmds == 0)
6803 /* There are still running processes in the fg pipe */
6804 goto wait_more; /* do waitpid again */
6806 /* it wasnt fg_pipe, look for process in bg pipes */
6810 /* We asked to wait for bg or orphaned children */
6811 /* No need to remember exitcode in this case */
6812 for (pi = G.job_list; pi; pi = pi->next) {
6813 for (i = 0; i < pi->num_cmds; i++) {
6814 if (pi->cmds[i].pid == childpid)
6815 goto found_pi_and_prognum;
6818 /* Happens when shell is used as init process (init=/bin/sh) */
6819 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6820 continue; /* do waitpid again */
6822 found_pi_and_prognum:
6825 pi->cmds[i].pid = 0;
6827 if (!pi->alive_cmds) {
6828 if (G_interactive_fd)
6829 printf(JOB_STATUS_FORMAT, pi->jobid,
6830 "Done", pi->cmdtext);
6831 delete_finished_bg_job(pi);
6838 } /* while (waitpid succeeds)... */
6844 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6847 int rcode = checkjobs(fg_pipe);
6848 if (G_saved_tty_pgrp) {
6849 /* Job finished, move the shell to the foreground */
6850 p = getpgrp(); /* our process group id */
6851 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6852 tcsetpgrp(G_interactive_fd, p);
6858 /* Start all the jobs, but don't wait for anything to finish.
6861 * Return code is normally -1, when the caller has to wait for children
6862 * to finish to determine the exit status of the pipe. If the pipe
6863 * is a simple builtin command, however, the action is done by the
6864 * time run_pipe returns, and the exit code is provided as the
6867 * Returns -1 only if started some children. IOW: we have to
6868 * mask out retvals of builtins etc with 0xff!
6870 * The only case when we do not need to [v]fork is when the pipe
6871 * is single, non-backgrounded, non-subshell command. Examples:
6872 * cmd ; ... { list } ; ...
6873 * cmd && ... { list } && ...
6874 * cmd || ... { list } || ...
6875 * If it is, then we can run cmd as a builtin, NOFORK,
6876 * or (if SH_STANDALONE) an applet, and we can run the { list }
6877 * with run_list. If it isn't one of these, we fork and exec cmd.
6879 * Cases when we must fork:
6880 * non-single: cmd | cmd
6881 * backgrounded: cmd & { list } &
6882 * subshell: ( list ) [&]
6884 #if !ENABLE_HUSH_MODE_X
6885 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6886 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6888 static int redirect_and_varexp_helper(char ***new_env_p,
6889 struct variable **old_vars_p,
6890 struct command *command,
6892 char **argv_expanded)
6894 /* setup_redirects acts on file descriptors, not FILEs.
6895 * This is perfect for work that comes after exec().
6896 * Is it really safe for inline use? Experimentally,
6897 * things seem to work. */
6898 int rcode = setup_redirects(command, squirrel);
6900 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6901 *new_env_p = new_env;
6902 dump_cmd_in_x_mode(new_env);
6903 dump_cmd_in_x_mode(argv_expanded);
6905 *old_vars_p = set_vars_and_save_old(new_env);
6909 static NOINLINE int run_pipe(struct pipe *pi)
6911 static const char *const null_ptr = NULL;
6915 struct command *command;
6916 char **argv_expanded;
6918 /* it is not always needed, but we aim to smaller code */
6919 int squirrel[] = { -1, -1, -1 };
6922 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6925 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6926 * Result should be 3 lines: q w e, qwe, q w e
6928 G.ifs = get_local_var_value("IFS");
6932 IF_HUSH_JOB(pi->pgrp = -1;)
6933 pi->stopped_cmds = 0;
6934 command = &pi->cmds[0];
6935 argv_expanded = NULL;
6937 if (pi->num_cmds != 1
6938 || pi->followup == PIPE_BG
6939 || command->cmd_type == CMD_SUBSHELL
6946 debug_printf_exec(": group:%p argv:'%s'\n",
6947 command->group, command->argv ? command->argv[0] : "NONE");
6949 if (command->group) {
6950 #if ENABLE_HUSH_FUNCTIONS
6951 if (command->cmd_type == CMD_FUNCDEF) {
6952 /* "executing" func () { list } */
6953 struct function *funcp;
6955 funcp = new_function(command->argv[0]);
6956 /* funcp->name is already set to argv[0] */
6957 funcp->body = command->group;
6959 funcp->body_as_string = command->group_as_string;
6960 command->group_as_string = NULL;
6962 command->group = NULL;
6963 command->argv[0] = NULL;
6964 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6965 funcp->parent_cmd = command;
6966 command->child_func = funcp;
6968 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6970 return EXIT_SUCCESS;
6974 debug_printf("non-subshell group\n");
6975 rcode = 1; /* exitcode if redir failed */
6976 if (setup_redirects(command, squirrel) == 0) {
6977 debug_printf_exec(": run_list\n");
6978 rcode = run_list(command->group) & 0xff;
6980 restore_redirects(squirrel);
6981 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6983 debug_printf_exec("run_pipe: return %d\n", rcode);
6987 argv = command->argv ? command->argv : (char **) &null_ptr;
6989 const struct built_in_command *x;
6990 #if ENABLE_HUSH_FUNCTIONS
6991 const struct function *funcp;
6995 char **new_env = NULL;
6996 struct variable *old_vars = NULL;
6998 if (argv[command->assignment_cnt] == NULL) {
6999 /* Assignments, but no command */
7000 /* Ensure redirects take effect (that is, create files).
7001 * Try "a=t >file" */
7002 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7003 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7004 /* Set shell variables */
7008 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7009 /* Do we need to flag set_local_var() errors?
7010 * "assignment to readonly var" and "putenv error"
7015 /* Redirect error sets $? to 1. Otherwise,
7016 * if evaluating assignment value set $?, retain it.
7017 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7019 rcode = G.last_exitcode;
7020 /* Exit, _skipping_ variable restoring code: */
7021 goto clean_up_and_ret0;
7023 #else /* Older, bigger, but more correct code */
7025 rcode = setup_redirects(command, squirrel);
7026 restore_redirects(squirrel);
7027 /* Set shell variables */
7029 bb_putchar_stderr('+');
7031 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7033 fprintf(stderr, " %s", p);
7034 debug_printf_exec("set shell var:'%s'->'%s'\n",
7036 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7037 /* Do we need to flag set_local_var() errors?
7038 * "assignment to readonly var" and "putenv error"
7043 bb_putchar_stderr('\n');
7044 /* Redirect error sets $? to 1. Otherwise,
7045 * if evaluating assignment value set $?, retain it.
7046 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7048 rcode = G.last_exitcode;
7049 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7051 debug_printf_exec("run_pipe: return %d\n", rcode);
7056 /* Expand the rest into (possibly) many strings each */
7057 #if ENABLE_HUSH_BASH_COMPAT
7058 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7059 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7063 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7066 /* if someone gives us an empty string: `cmd with empty output` */
7067 if (!argv_expanded[0]) {
7068 free(argv_expanded);
7070 return G.last_exitcode;
7073 x = find_builtin(argv_expanded[0]);
7074 #if ENABLE_HUSH_FUNCTIONS
7077 funcp = find_function(argv_expanded[0]);
7081 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7082 debug_printf("exec with redirects only\n");
7083 rcode = setup_redirects(command, NULL);
7084 goto clean_up_and_ret1;
7087 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7090 debug_printf_exec(": builtin '%s' '%s'...\n",
7091 x->b_cmd, argv_expanded[1]);
7093 rcode = x->b_function(argv_expanded) & 0xff;
7096 #if ENABLE_HUSH_FUNCTIONS
7098 # if ENABLE_HUSH_LOCAL
7099 struct variable **sv;
7100 sv = G.shadowed_vars_pp;
7101 G.shadowed_vars_pp = &old_vars;
7103 debug_printf_exec(": function '%s' '%s'...\n",
7104 funcp->name, argv_expanded[1]);
7105 rcode = run_function(funcp, argv_expanded) & 0xff;
7106 # if ENABLE_HUSH_LOCAL
7107 G.shadowed_vars_pp = sv;
7113 unset_vars(new_env);
7115 /* clean_up_and_ret0: */
7116 restore_redirects(squirrel);
7118 free(argv_expanded);
7119 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7121 debug_printf_exec("run_pipe return %d\n", rcode);
7125 if (ENABLE_FEATURE_SH_NOFORK) {
7126 int n = find_applet_by_name(argv_expanded[0]);
7127 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7128 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7130 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7131 argv_expanded[0], argv_expanded[1]);
7132 rcode = run_nofork_applet(n, argv_expanded);
7134 goto clean_up_and_ret;
7137 /* It is neither builtin nor applet. We must fork. */
7141 /* NB: argv_expanded may already be created, and that
7142 * might include `cmd` runs! Do not rerun it! We *must*
7143 * use argv_expanded if it's non-NULL */
7145 /* Going to fork a child per each pipe member */
7150 while (cmd_no < pi->num_cmds) {
7151 struct fd_pair pipefds;
7153 volatile nommu_save_t nommu_save;
7154 nommu_save.new_env = NULL;
7155 nommu_save.old_vars = NULL;
7156 nommu_save.argv = NULL;
7157 nommu_save.argv_from_re_execing = NULL;
7159 command = &pi->cmds[cmd_no];
7161 if (command->argv) {
7162 debug_printf_exec(": pipe member '%s' '%s'...\n",
7163 command->argv[0], command->argv[1]);
7165 debug_printf_exec(": pipe member with no argv\n");
7168 /* pipes are inserted between pairs of commands */
7171 if (cmd_no < pi->num_cmds)
7172 xpiped_pair(pipefds);
7174 command->pid = BB_MMU ? fork() : vfork();
7175 if (!command->pid) { /* child */
7177 disable_restore_tty_pgrp_on_exit();
7178 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7180 /* Every child adds itself to new process group
7181 * with pgid == pid_of_first_child_in_pipe */
7182 if (G.run_list_level == 1 && G_interactive_fd) {
7185 if (pgrp < 0) /* true for 1st process only */
7187 if (setpgid(0, pgrp) == 0
7188 && pi->followup != PIPE_BG
7189 && G_saved_tty_pgrp /* we have ctty */
7191 /* We do it in *every* child, not just first,
7193 tcsetpgrp(G_interactive_fd, pgrp);
7197 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7198 /* 1st cmd in backgrounded pipe
7199 * should have its stdin /dev/null'ed */
7201 if (open(bb_dev_null, O_RDONLY))
7202 xopen("/", O_RDONLY);
7204 xmove_fd(next_infd, 0);
7206 xmove_fd(pipefds.wr, 1);
7209 /* Like bash, explicit redirects override pipes,
7210 * and the pipe fd is available for dup'ing. */
7211 if (setup_redirects(command, NULL))
7214 /* Stores to nommu_save list of env vars putenv'ed
7215 * (NOMMU, on MMU we don't need that) */
7216 /* cast away volatility... */
7217 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7218 /* pseudo_exec() does not return */
7221 /* parent or error */
7222 #if ENABLE_HUSH_FAST
7224 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7226 enable_restore_tty_pgrp_on_exit();
7228 /* Clean up after vforked child */
7229 free(nommu_save.argv);
7230 free(nommu_save.argv_from_re_execing);
7231 unset_vars(nommu_save.new_env);
7232 add_vars(nommu_save.old_vars);
7234 free(argv_expanded);
7235 argv_expanded = NULL;
7236 if (command->pid < 0) { /* [v]fork failed */
7237 /* Clearly indicate, was it fork or vfork */
7238 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7242 /* Second and next children need to know pid of first one */
7244 pi->pgrp = command->pid;
7250 if (cmd_no < pi->num_cmds)
7252 /* Pass read (output) pipe end to next iteration */
7253 next_infd = pipefds.rd;
7256 if (!pi->alive_cmds) {
7258 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7263 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7267 /* NB: called by pseudo_exec, and therefore must not modify any
7268 * global data until exec/_exit (we can be a child after vfork!) */
7269 static int run_list(struct pipe *pi)
7271 #if ENABLE_HUSH_CASE
7272 char *case_word = NULL;
7274 #if ENABLE_HUSH_LOOPS
7275 struct pipe *loop_top = NULL;
7276 char **for_lcur = NULL;
7277 char **for_list = NULL;
7279 smallint last_followup;
7281 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7282 smalluint cond_code = 0;
7284 enum { cond_code = 0 };
7287 smallint rword; /* RES_foo */
7288 smallint last_rword; /* ditto */
7291 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7294 #if ENABLE_HUSH_LOOPS
7295 /* Check syntax for "for" */
7298 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7299 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7301 /* current word is FOR or IN (BOLD in comments below) */
7302 if (cpipe->next == NULL) {
7303 syntax_error("malformed for");
7305 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7308 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7309 if (cpipe->next->res_word == RES_DO)
7311 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7312 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7313 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7315 syntax_error("malformed for");
7317 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7324 /* Past this point, all code paths should jump to ret: label
7325 * in order to return, no direct "return" statements please.
7326 * This helps to ensure that no memory is leaked. */
7334 last_rword = RES_XXXX;
7336 last_followup = PIPE_SEQ;
7337 rcode = G.last_exitcode;
7339 /* Go through list of pipes, (maybe) executing them. */
7340 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7344 IF_HAS_KEYWORDS(rword = pi->res_word;)
7345 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7346 rword, cond_code, last_rword);
7347 #if ENABLE_HUSH_LOOPS
7348 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7349 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7351 /* start of a loop: remember where loop starts */
7356 /* Still in the same "if...", "then..." or "do..." branch? */
7357 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7358 if ((rcode == 0 && last_followup == PIPE_OR)
7359 || (rcode != 0 && last_followup == PIPE_AND)
7361 /* It is "<true> || CMD" or "<false> && CMD"
7362 * and we should not execute CMD */
7363 debug_printf_exec("skipped cmd because of || or &&\n");
7364 last_followup = pi->followup;
7365 goto dont_check_jobs_but_continue;
7368 last_followup = pi->followup;
7369 IF_HAS_KEYWORDS(last_rword = rword;)
7372 if (rword == RES_THEN) {
7373 /* if false; then ... fi has exitcode 0! */
7374 G.last_exitcode = rcode = EXIT_SUCCESS;
7375 /* "if <false> THEN cmd": skip cmd */
7379 if (rword == RES_ELSE || rword == RES_ELIF) {
7380 /* "if <true> then ... ELSE/ELIF cmd":
7381 * skip cmd and all following ones */
7386 #if ENABLE_HUSH_LOOPS
7387 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7389 /* first loop through for */
7391 static const char encoded_dollar_at[] ALIGN1 = {
7392 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7393 }; /* encoded representation of "$@" */
7394 static const char *const encoded_dollar_at_argv[] = {
7395 encoded_dollar_at, NULL
7396 }; /* argv list with one element: "$@" */
7399 vals = (char**)encoded_dollar_at_argv;
7400 if (pi->next->res_word == RES_IN) {
7401 /* if no variable values after "in" we skip "for" */
7402 if (!pi->next->cmds[0].argv) {
7403 G.last_exitcode = rcode = EXIT_SUCCESS;
7404 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7407 vals = pi->next->cmds[0].argv;
7408 } /* else: "for var; do..." -> assume "$@" list */
7409 /* create list of variable values */
7410 debug_print_strings("for_list made from", vals);
7411 for_list = expand_strvec_to_strvec(vals);
7412 for_lcur = for_list;
7413 debug_print_strings("for_list", for_list);
7416 /* "for" loop is over, clean up */
7422 /* Insert next value from for_lcur */
7423 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7424 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7427 if (rword == RES_IN) {
7428 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7430 if (rword == RES_DONE) {
7431 continue; /* "done" has no cmds too */
7434 #if ENABLE_HUSH_CASE
7435 if (rword == RES_CASE) {
7436 case_word = expand_strvec_to_string(pi->cmds->argv);
7439 if (rword == RES_MATCH) {
7442 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7444 /* all prev words didn't match, does this one match? */
7445 argv = pi->cmds->argv;
7447 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7448 /* TODO: which FNM_xxx flags to use? */
7449 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7451 if (cond_code == 0) { /* match! we will execute this branch */
7452 free(case_word); /* make future "word)" stop */
7460 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7462 continue; /* not matched yet, skip this pipe */
7465 /* Just pressing <enter> in shell should check for jobs.
7466 * OTOH, in non-interactive shell this is useless
7467 * and only leads to extra job checks */
7468 if (pi->num_cmds == 0) {
7469 if (G_interactive_fd)
7470 goto check_jobs_and_continue;
7474 /* After analyzing all keywords and conditions, we decided
7475 * to execute this pipe. NB: have to do checkjobs(NULL)
7476 * after run_pipe to collect any background children,
7477 * even if list execution is to be stopped. */
7478 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7481 #if ENABLE_HUSH_LOOPS
7482 G.flag_break_continue = 0;
7484 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7486 /* We ran a builtin, function, or group.
7487 * rcode is already known
7488 * and we don't need to wait for anything. */
7489 G.last_exitcode = rcode;
7490 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7491 check_and_run_traps();
7492 #if ENABLE_HUSH_LOOPS
7493 /* Was it "break" or "continue"? */
7494 if (G.flag_break_continue) {
7495 smallint fbc = G.flag_break_continue;
7496 /* We might fall into outer *loop*,
7497 * don't want to break it too */
7499 G.depth_break_continue--;
7500 if (G.depth_break_continue == 0)
7501 G.flag_break_continue = 0;
7502 /* else: e.g. "continue 2" should *break* once, *then* continue */
7503 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7504 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7508 /* "continue": simulate end of loop */
7513 #if ENABLE_HUSH_FUNCTIONS
7514 if (G.flag_return_in_progress == 1) {
7519 } else if (pi->followup == PIPE_BG) {
7520 /* What does bash do with attempts to background builtins? */
7521 /* even bash 3.2 doesn't do that well with nested bg:
7522 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7523 * I'm NOT treating inner &'s as jobs */
7524 check_and_run_traps();
7526 if (G.run_list_level == 1)
7529 /* Last command's pid goes to $! */
7530 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7531 G.last_exitcode = rcode = EXIT_SUCCESS;
7532 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7535 if (G.run_list_level == 1 && G_interactive_fd) {
7536 /* Waits for completion, then fg's main shell */
7537 rcode = checkjobs_and_fg_shell(pi);
7538 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7539 check_and_run_traps();
7542 { /* This one just waits for completion */
7543 rcode = checkjobs(pi);
7544 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7545 check_and_run_traps();
7547 G.last_exitcode = rcode;
7551 /* Analyze how result affects subsequent commands */
7553 if (rword == RES_IF || rword == RES_ELIF)
7556 check_jobs_and_continue:
7558 dont_check_jobs_but_continue: ;
7559 #if ENABLE_HUSH_LOOPS
7560 /* Beware of "while false; true; do ..."! */
7562 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7563 /* check for RES_DONE is needed for "while ...; do \n done" case */
7565 if (rword == RES_WHILE) {
7567 /* "while false; do...done" - exitcode 0 */
7568 G.last_exitcode = rcode = EXIT_SUCCESS;
7569 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7573 if (rword == RES_UNTIL) {
7575 debug_printf_exec(": until expr is true: breaking\n");
7586 #if ENABLE_HUSH_LOOPS
7591 #if ENABLE_HUSH_CASE
7595 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7599 /* Select which version we will use */
7600 static int run_and_free_list(struct pipe *pi)
7603 debug_printf_exec("run_and_free_list entered\n");
7604 if (!G.o_opt[OPT_O_NOEXEC]) {
7605 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7606 rcode = run_list(pi);
7608 /* free_pipe_list has the side effect of clearing memory.
7609 * In the long run that function can be merged with run_list,
7610 * but doing that now would hobble the debugging effort. */
7612 debug_printf_exec("run_and_free_list return %d\n", rcode);
7617 static void install_sighandlers(unsigned mask)
7619 sighandler_t old_handler;
7621 while ((mask >>= 1) != 0) {
7625 old_handler = install_sighandler(sig, pick_sighandler(sig));
7626 /* POSIX allows shell to re-enable SIGCHLD
7627 * even if it was SIG_IGN on entry.
7628 * Therefore we skip IGN check for it:
7632 if (old_handler == SIG_IGN) {
7633 /* oops... restore back to IGN, and record this fact */
7634 install_sighandler(sig, old_handler);
7636 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7638 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7643 /* Called a few times only (or even once if "sh -c") */
7644 static void install_special_sighandlers(void)
7648 /* Which signals are shell-special? */
7649 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
7650 if (G_interactive_fd) {
7651 mask |= SPECIAL_INTERACTIVE_SIGS;
7652 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7653 mask |= SPECIAL_JOBSTOP_SIGS;
7655 /* Careful, do not re-install handlers we already installed */
7656 if (G.special_sig_mask != mask) {
7657 unsigned diff = mask & ~G.special_sig_mask;
7658 G.special_sig_mask = mask;
7659 install_sighandlers(diff);
7665 /* Set handlers to restore tty pgrp and exit */
7666 static void install_fatal_sighandlers(void)
7670 /* We will restore tty pgrp on these signals */
7672 + (1 << SIGILL ) * HUSH_DEBUG
7673 + (1 << SIGFPE ) * HUSH_DEBUG
7674 + (1 << SIGBUS ) * HUSH_DEBUG
7675 + (1 << SIGSEGV) * HUSH_DEBUG
7676 + (1 << SIGTRAP) * HUSH_DEBUG
7678 /* bash 3.2 seems to handle these just like 'fatal' ones */
7681 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
7682 * if we aren't interactive... but in this case
7683 * we never want to restore pgrp on exit, and this fn is not called
7685 /*+ (1 << SIGHUP )*/
7686 /*+ (1 << SIGTERM)*/
7687 /*+ (1 << SIGINT )*/
7689 G_fatal_sig_mask = mask;
7691 install_sighandlers(mask);
7695 static int set_mode(int state, char mode, const char *o_opt)
7700 G.o_opt[OPT_O_NOEXEC] = state;
7703 IF_HUSH_MODE_X(G_x_mode = state;)
7707 /* "set -+o" without parameter.
7708 * in bash, set -o produces this output:
7712 * We always use the second form.
7714 const char *p = o_opt_strings;
7717 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7723 idx = index_in_strings(o_opt_strings, o_opt);
7725 G.o_opt[idx] = state;
7729 return EXIT_FAILURE;
7731 return EXIT_SUCCESS;
7734 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7735 int hush_main(int argc, char **argv)
7738 OPT_login = (1 << 0),
7742 unsigned builtin_argc;
7744 struct variable *cur_var;
7745 struct variable *shell_ver;
7748 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
7749 G.last_exitcode = EXIT_SUCCESS;
7750 #if ENABLE_HUSH_FAST
7751 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7754 G.argv0_for_re_execing = argv[0];
7756 /* Deal with HUSH_VERSION */
7757 shell_ver = xzalloc(sizeof(*shell_ver));
7758 shell_ver->flg_export = 1;
7759 shell_ver->flg_read_only = 1;
7760 /* Code which handles ${var<op>...} needs writable values for all variables,
7761 * therefore we xstrdup: */
7762 shell_ver->varstr = xstrdup(hush_version_str);
7763 /* Create shell local variables from the values
7764 * currently living in the environment */
7765 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7766 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7767 G.top_var = shell_ver;
7768 cur_var = G.top_var;
7771 char *value = strchr(*e, '=');
7772 if (value) { /* paranoia */
7773 cur_var->next = xzalloc(sizeof(*cur_var));
7774 cur_var = cur_var->next;
7775 cur_var->varstr = *e;
7776 cur_var->max_len = strlen(*e);
7777 cur_var->flg_export = 1;
7781 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7782 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
7783 putenv(shell_ver->varstr);
7786 set_pwd_var(/*exp:*/ 1);
7787 /* bash also exports SHLVL and _,
7788 * and sets (but doesn't export) the following variables:
7790 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7791 * BASH_VERSION='3.2.0(1)-release'
7793 * MACHTYPE=i386-pc-linux-gnu
7795 * HOSTNAME=<xxxxxxxxxx>
7796 * PPID=<NNNNN> - we also do it elsewhere
7807 * PIPESTATUS=([0]="0")
7808 * HISTFILE=/<xxx>/.bash_history
7812 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7814 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7824 #if ENABLE_FEATURE_EDITING
7825 G.line_input_state = new_line_input_t(FOR_SHELL);
7828 /* Initialize some more globals to non-zero values */
7829 cmdedit_update_prompt();
7831 if (setjmp(die_jmp)) {
7832 /* xfunc has failed! die die die */
7833 /* no EXIT traps, this is an escape hatch! */
7835 hush_exit(xfunc_error_retval);
7838 /* Shell is non-interactive at first. We need to call
7839 * install_special_sighandlers() if we are going to execute "sh <script>",
7840 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7841 * If we later decide that we are interactive, we run install_special_sighandlers()
7842 * in order to intercept (more) signals.
7846 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7847 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
7850 opt = getopt(argc, argv, "+c:xinsl"
7853 # if ENABLE_HUSH_FUNCTIONS
7863 * sh ... -c 'script'
7864 * sh ... -c 'script' ARG0 [ARG1...]
7865 * On NOMMU, if builtin_argc != 0,
7866 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7867 * "" needs to be replaced with NULL
7868 * and BARGV vector fed to builtin function.
7869 * Note: the form without ARG0 never happens:
7870 * sh ... -c 'builtin' BARGV... ""
7873 G.root_pid = getpid();
7874 G.root_ppid = getppid();
7876 G.global_argv = argv + optind;
7877 G.global_argc = argc - optind;
7879 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7880 const struct built_in_command *x;
7882 install_special_sighandlers();
7883 x = find_builtin(optarg);
7884 if (x) { /* paranoia */
7885 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7886 G.global_argv += builtin_argc;
7887 G.global_argv[-1] = NULL; /* replace "" */
7889 G.last_exitcode = x->b_function(argv + optind - 1);
7893 if (!G.global_argv[0]) {
7894 /* -c 'script' (no params): prevent empty $0 */
7895 G.global_argv--; /* points to argv[i] of 'script' */
7896 G.global_argv[0] = argv[0];
7898 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7899 install_special_sighandlers();
7900 parse_and_run_string(optarg);
7903 /* Well, we cannot just declare interactiveness,
7904 * we have to have some stuff (ctty, etc) */
7905 /* G_interactive_fd++; */
7908 /* "-s" means "read from stdin", but this is how we always
7909 * operate, so simply do nothing here. */
7915 case '<': /* "big heredoc" support */
7916 full_write1_str(optarg);
7919 unsigned long long empty_trap_mask;
7921 G.root_pid = bb_strtou(optarg, &optarg, 16);
7923 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7925 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7927 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7929 builtin_argc = bb_strtou(optarg, &optarg, 16);
7931 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7932 if (empty_trap_mask != 0) {
7934 install_special_sighandlers();
7935 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7936 for (sig = 1; sig < NSIG; sig++) {
7937 if (empty_trap_mask & (1LL << sig)) {
7938 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7939 install_sighandler(sig, SIG_IGN);
7943 # if ENABLE_HUSH_LOOPS
7945 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7951 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7953 # if ENABLE_HUSH_FUNCTIONS
7955 struct function *funcp = new_function(optarg);
7956 /* funcp->name is already set to optarg */
7957 /* funcp->body is set to NULL. It's a special case. */
7958 funcp->body_as_string = argv[optind];
7966 if (set_mode(1, opt, NULL) == 0) /* no error */
7970 fprintf(stderr, "Usage: sh [FILE]...\n"
7971 " or: sh -c command [args]...\n\n");
7977 } /* option parsing loop */
7979 /* Skip options. Try "hush -l": $1 should not be "-l"! */
7980 G.global_argc = argc - (optind - 1);
7981 G.global_argv = argv + (optind - 1);
7982 G.global_argv[0] = argv[0];
7985 G.root_pid = getpid();
7986 G.root_ppid = getppid();
7989 /* If we are login shell... */
7990 if (flags & OPT_login) {
7992 debug_printf("sourcing /etc/profile\n");
7993 input = fopen_for_read("/etc/profile");
7994 if (input != NULL) {
7995 close_on_exec_on(fileno(input));
7996 install_special_sighandlers();
7997 parse_and_run_file(input);
8000 /* bash: after sourcing /etc/profile,
8001 * tries to source (in the given order):
8002 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8003 * stopping on first found. --noprofile turns this off.
8004 * bash also sources ~/.bash_logout on exit.
8005 * If called as sh, skips .bash_XXX files.
8009 if (G.global_argv[1]) {
8012 * "bash <script>" (which is never interactive (unless -i?))
8013 * sources $BASH_ENV here (without scanning $PATH).
8014 * If called as sh, does the same but with $ENV.
8018 debug_printf("running script '%s'\n", G.global_argv[0]);
8019 input = xfopen_for_read(G.global_argv[0]);
8020 close_on_exec_on(fileno(input));
8021 install_special_sighandlers();
8022 parse_and_run_file(input);
8023 #if ENABLE_FEATURE_CLEAN_UP
8029 /* Up to here, shell was non-interactive. Now it may become one.
8030 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8033 /* A shell is interactive if the '-i' flag was given,
8034 * or if all of the following conditions are met:
8036 * no arguments remaining or the -s flag given
8037 * standard input is a terminal
8038 * standard output is a terminal
8039 * Refer to Posix.2, the description of the 'sh' utility.
8042 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8043 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8044 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8045 if (G_saved_tty_pgrp < 0)
8046 G_saved_tty_pgrp = 0;
8048 /* try to dup stdin to high fd#, >= 255 */
8049 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8050 if (G_interactive_fd < 0) {
8051 /* try to dup to any fd */
8052 G_interactive_fd = dup(STDIN_FILENO);
8053 if (G_interactive_fd < 0) {
8055 G_interactive_fd = 0;
8056 G_saved_tty_pgrp = 0;
8059 // TODO: track & disallow any attempts of user
8060 // to (inadvertently) close/redirect G_interactive_fd
8062 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8063 if (G_interactive_fd) {
8064 close_on_exec_on(G_interactive_fd);
8066 if (G_saved_tty_pgrp) {
8067 /* If we were run as 'hush &', sleep until we are
8068 * in the foreground (tty pgrp == our pgrp).
8069 * If we get started under a job aware app (like bash),
8070 * make sure we are now in charge so we don't fight over
8071 * who gets the foreground */
8073 pid_t shell_pgrp = getpgrp();
8074 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8075 if (G_saved_tty_pgrp == shell_pgrp)
8077 /* send TTIN to ourself (should stop us) */
8078 kill(- shell_pgrp, SIGTTIN);
8082 /* Install more signal handlers */
8083 install_special_sighandlers();
8085 if (G_saved_tty_pgrp) {
8086 /* Set other signals to restore saved_tty_pgrp */
8087 install_fatal_sighandlers();
8088 /* Put ourselves in our own process group
8089 * (bash, too, does this only if ctty is available) */
8090 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8091 /* Grab control of the terminal */
8092 tcsetpgrp(G_interactive_fd, getpid());
8094 /* -1 is special - makes xfuncs longjmp, not exit
8095 * (we reset die_sleep = 0 whereever we [v]fork) */
8096 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
8098 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8100 const char *hp = get_local_var_value("HISTFILE");
8102 hp = get_local_var_value("HOME");
8104 hp = concat_path_file(hp, ".hush_history");
8109 G.line_input_state->hist_file = hp;
8110 //set_local_var(xasprintf("HISTFILE=%s", ...));
8112 # if ENABLE_FEATURE_SH_HISTFILESIZE
8113 hp = get_local_var_value("HISTFILESIZE");
8114 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8119 install_special_sighandlers();
8121 #elif ENABLE_HUSH_INTERACTIVE
8122 /* No job control compiled in, only prompt/line editing */
8123 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8124 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8125 if (G_interactive_fd < 0) {
8126 /* try to dup to any fd */
8127 G_interactive_fd = dup(STDIN_FILENO);
8128 if (G_interactive_fd < 0)
8130 G_interactive_fd = 0;
8133 if (G_interactive_fd) {
8134 close_on_exec_on(G_interactive_fd);
8136 install_special_sighandlers();
8138 /* We have interactiveness code disabled */
8139 install_special_sighandlers();
8142 * if interactive but not a login shell, sources ~/.bashrc
8143 * (--norc turns this off, --rcfile <file> overrides)
8146 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8147 /* note: ash and hush share this string */
8148 printf("\n\n%s %s\n"
8149 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8152 "hush - the humble shell"
8156 parse_and_run_file(stdin);
8159 hush_exit(G.last_exitcode);
8164 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8165 int msh_main(int argc, char **argv)
8167 //bb_error_msg("msh is deprecated, please use hush instead");
8168 return hush_main(argc, argv);
8176 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8181 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8188 return applet_main_func(argc, argv - argc);
8191 static int FAST_FUNC builtin_test(char **argv)
8193 return run_applet_main(argv, test_main);
8196 static int FAST_FUNC builtin_echo(char **argv)
8198 return run_applet_main(argv, echo_main);
8202 static int FAST_FUNC builtin_printf(char **argv)
8204 return run_applet_main(argv, printf_main);
8208 static char **skip_dash_dash(char **argv)
8211 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8216 static int FAST_FUNC builtin_eval(char **argv)
8218 int rcode = EXIT_SUCCESS;
8220 argv = skip_dash_dash(argv);
8222 char *str = expand_strvec_to_string(argv);
8224 * eval "echo Hi; done" ("done" is syntax error):
8225 * "echo Hi" will not execute too.
8227 parse_and_run_string(str);
8229 rcode = G.last_exitcode;
8234 static int FAST_FUNC builtin_cd(char **argv)
8238 argv = skip_dash_dash(argv);
8240 if (newdir == NULL) {
8241 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8242 * bash says "bash: cd: HOME not set" and does nothing
8245 const char *home = get_local_var_value("HOME");
8246 newdir = home ? home : "/";
8248 if (chdir(newdir)) {
8249 /* Mimic bash message exactly */
8250 bb_perror_msg("cd: %s", newdir);
8251 return EXIT_FAILURE;
8253 /* Read current dir (get_cwd(1) is inside) and set PWD.
8254 * Note: do not enforce exporting. If PWD was unset or unexported,
8255 * set it again, but do not export. bash does the same.
8257 set_pwd_var(/*exp:*/ 0);
8258 return EXIT_SUCCESS;
8261 static int FAST_FUNC builtin_exec(char **argv)
8263 argv = skip_dash_dash(argv);
8264 if (argv[0] == NULL)
8265 return EXIT_SUCCESS; /* bash does this */
8267 /* Careful: we can end up here after [v]fork. Do not restore
8268 * tty pgrp then, only top-level shell process does that */
8269 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8270 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8272 /* TODO: if exec fails, bash does NOT exit! We do.
8273 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8274 * and tcsetpgrp, and this is inherently racy.
8276 execvp_or_die(argv);
8279 static int FAST_FUNC builtin_exit(char **argv)
8281 debug_printf_exec("%s()\n", __func__);
8283 /* interactive bash:
8284 * # trap "echo EEE" EXIT
8287 * There are stopped jobs.
8288 * (if there are _stopped_ jobs, running ones don't count)
8291 * EEE (then bash exits)
8293 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8296 /* note: EXIT trap is run by hush_exit */
8297 argv = skip_dash_dash(argv);
8298 if (argv[0] == NULL)
8299 hush_exit(G.last_exitcode);
8300 /* mimic bash: exit 123abc == exit 255 + error msg */
8301 xfunc_error_retval = 255;
8302 /* bash: exit -2 == exit 254, no error msg */
8303 hush_exit(xatoi(argv[0]) & 0xff);
8306 static void print_escaped(const char *s)
8311 const char *p = strchrnul(s, '\'');
8312 /* print 'xxxx', possibly just '' */
8313 printf("'%.*s'", (int)(p - s), s);
8318 /* s points to '; print "'''...'''" */
8320 do putchar('\''); while (*++s == '\'');
8325 #if !ENABLE_HUSH_LOCAL
8326 #define helper_export_local(argv, exp, lvl) \
8327 helper_export_local(argv, exp)
8329 static void helper_export_local(char **argv, int exp, int lvl)
8333 char *name_end = strchrnul(name, '=');
8335 /* So far we do not check that name is valid (TODO?) */
8337 if (*name_end == '\0') {
8338 struct variable *var, **vpp;
8340 vpp = get_ptr_to_local_var(name, name_end - name);
8341 var = vpp ? *vpp : NULL;
8343 if (exp == -1) { /* unexporting? */
8344 /* export -n NAME (without =VALUE) */
8346 var->flg_export = 0;
8347 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8349 } /* else: export -n NOT_EXISTING_VAR: no-op */
8352 if (exp == 1) { /* exporting? */
8353 /* export NAME (without =VALUE) */
8355 var->flg_export = 1;
8356 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8357 putenv(var->varstr);
8361 /* Exporting non-existing variable.
8362 * bash does not put it in environment,
8363 * but remembers that it is exported,
8364 * and does put it in env when it is set later.
8365 * We just set it to "" and export. */
8366 /* Or, it's "local NAME" (without =VALUE).
8367 * bash sets the value to "". */
8368 name = xasprintf("%s=", name);
8370 /* (Un)exporting/making local NAME=VALUE */
8371 name = xstrdup(name);
8373 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8377 static int FAST_FUNC builtin_export(char **argv)
8379 unsigned opt_unexport;
8381 #if ENABLE_HUSH_EXPORT_N
8382 /* "!": do not abort on errors */
8383 opt_unexport = getopt32(argv, "!n");
8384 if (opt_unexport == (uint32_t)-1)
8385 return EXIT_FAILURE;
8392 if (argv[0] == NULL) {
8399 /* ash emits: export VAR='VAL'
8400 * bash: declare -x VAR="VAL"
8401 * we follow ash example */
8402 const char *s = *e++;
8403 const char *p = strchr(s, '=');
8405 if (!p) /* wtf? take next variable */
8408 printf("export %.*s", (int)(p - s) + 1, s);
8409 print_escaped(p + 1);
8413 /*fflush_all(); - done after each builtin anyway */
8415 return EXIT_SUCCESS;
8418 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8420 return EXIT_SUCCESS;
8423 #if ENABLE_HUSH_LOCAL
8424 static int FAST_FUNC builtin_local(char **argv)
8426 if (G.func_nest_level == 0) {
8427 bb_error_msg("%s: not in a function", argv[0]);
8428 return EXIT_FAILURE; /* bash compat */
8430 helper_export_local(argv, 0, G.func_nest_level);
8431 return EXIT_SUCCESS;
8435 static int FAST_FUNC builtin_trap(char **argv)
8441 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8446 /* No args: print all trapped */
8447 for (i = 0; i < NSIG; ++i) {
8450 print_escaped(G.traps[i]);
8451 /* note: bash adds "SIG", but only if invoked
8452 * as "bash". If called as "sh", or if set -o posix,
8453 * then it prints short signal names.
8454 * We are printing short names: */
8455 printf(" %s\n", get_signame(i));
8458 /*fflush_all(); - done after each builtin anyway */
8459 return EXIT_SUCCESS;
8463 /* If first arg is a number: reset all specified signals */
8464 sig = bb_strtou(*argv, NULL, 10);
8470 sighandler_t handler;
8472 sig = get_signum(*argv++);
8473 if (sig < 0 || sig >= NSIG) {
8475 /* Mimic bash message exactly */
8476 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8481 G.traps[sig] = xstrdup(new_cmd);
8483 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8484 get_signame(sig), sig, G.traps[sig]);
8486 /* There is no signal for 0 (EXIT) */
8491 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
8493 /* We are removing trap handler */
8494 handler = pick_sighandler(sig);
8495 install_sighandler(sig, handler);
8500 if (!argv[1]) { /* no second arg */
8501 bb_error_msg("trap: invalid arguments");
8502 return EXIT_FAILURE;
8505 /* First arg is "-": reset all specified to default */
8506 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8507 /* Everything else: set arg as signal handler
8508 * (includes "" case, which ignores signal) */
8509 if (argv[0][0] == '-') {
8510 if (argv[0][1] == '\0') { /* "-" */
8511 /* new_cmd remains NULL: "reset these sigs" */
8514 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8517 /* else: "-something", no special meaning */
8522 goto process_sig_list;
8525 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8526 static int FAST_FUNC builtin_type(char **argv)
8528 int ret = EXIT_SUCCESS;
8534 if (0) {} /* make conditional compile easier below */
8535 /*else if (find_alias(*argv))
8536 type = "an alias";*/
8537 #if ENABLE_HUSH_FUNCTIONS
8538 else if (find_function(*argv))
8539 type = "a function";
8541 else if (find_builtin(*argv))
8542 type = "a shell builtin";
8543 else if ((path = find_in_path(*argv)) != NULL)
8546 bb_error_msg("type: %s: not found", *argv);
8551 printf("%s is %s\n", *argv, type);
8559 /* built-in 'fg' and 'bg' handler */
8560 static int FAST_FUNC builtin_fg_bg(char **argv)
8565 if (!G_interactive_fd)
8566 return EXIT_FAILURE;
8568 /* If they gave us no args, assume they want the last backgrounded task */
8570 for (pi = G.job_list; pi; pi = pi->next) {
8571 if (pi->jobid == G.last_jobid) {
8575 bb_error_msg("%s: no current job", argv[0]);
8576 return EXIT_FAILURE;
8578 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8579 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8580 return EXIT_FAILURE;
8582 for (pi = G.job_list; pi; pi = pi->next) {
8583 if (pi->jobid == jobnum) {
8587 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8588 return EXIT_FAILURE;
8590 /* TODO: bash prints a string representation
8591 * of job being foregrounded (like "sleep 1 | cat") */
8592 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8593 /* Put the job into the foreground. */
8594 tcsetpgrp(G_interactive_fd, pi->pgrp);
8597 /* Restart the processes in the job */
8598 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8599 for (i = 0; i < pi->num_cmds; i++) {
8600 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8602 pi->stopped_cmds = 0;
8604 i = kill(- pi->pgrp, SIGCONT);
8606 if (errno == ESRCH) {
8607 delete_finished_bg_job(pi);
8608 return EXIT_SUCCESS;
8610 bb_perror_msg("kill (SIGCONT)");
8613 if (argv[0][0] == 'f') {
8615 return checkjobs_and_fg_shell(pi);
8617 return EXIT_SUCCESS;
8621 #if ENABLE_HUSH_HELP
8622 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8624 const struct built_in_command *x;
8627 "Built-in commands:\n"
8628 "------------------\n");
8629 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8631 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8634 return EXIT_SUCCESS;
8638 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8639 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8641 show_history(G.line_input_state);
8642 return EXIT_SUCCESS;
8647 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8650 const char *status_string;
8652 for (job = G.job_list; job; job = job->next) {
8653 if (job->alive_cmds == job->stopped_cmds)
8654 status_string = "Stopped";
8656 status_string = "Running";
8658 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8660 return EXIT_SUCCESS;
8665 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8670 # ifdef M_TRIM_THRESHOLD
8671 /* Optional. Reduces probability of false positives */
8674 /* Crude attempt to find where "free memory" starts,
8675 * sans fragmentation. */
8677 l = (unsigned long)p;
8680 if (l < (unsigned long)p) l = (unsigned long)p;
8683 if (!G.memleak_value)
8684 G.memleak_value = l;
8686 l -= G.memleak_value;
8693 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8698 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8701 return EXIT_SUCCESS;
8704 /* Interruptibility of read builtin in bash
8705 * (tested on bash-4.2.8 by sending signals (not by ^C)):
8707 * Empty trap makes read ignore corresponding signal, for any signal.
8710 * - terminates non-interactive shell;
8711 * - interrupts read in interactive shell;
8712 * if it has non-empty trap:
8713 * - executes trap and returns to command prompt in interactive shell;
8714 * - executes trap and returns to read in non-interactive shell;
8716 * - is ignored (does not interrupt) read in interactive shell;
8717 * - terminates non-interactive shell;
8718 * if it has non-empty trap:
8719 * - executes trap and returns to read;
8721 * - terminates shell (regardless of interactivity);
8722 * if it has non-empty trap:
8723 * - executes trap and returns to read;
8725 static int FAST_FUNC builtin_read(char **argv)
8735 /* "!": do not abort on errors.
8736 * Option string must start with "sr" to match BUILTIN_READ_xxx
8738 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8739 if (read_flags == (uint32_t)-1)
8740 return EXIT_FAILURE;
8742 ifs = get_local_var_value("IFS"); /* can be NULL */
8745 r = shell_builtin_read(set_local_var_from_halves,
8755 if ((uintptr_t)r == 1 && errno == EINTR) {
8756 unsigned sig = check_and_run_traps();
8757 if (sig && sig != SIGINT)
8761 if ((uintptr_t)r > 1) {
8762 bb_error_msg("%s", r);
8763 r = (char*)(uintptr_t)1;
8766 return (uintptr_t)r;
8769 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8770 * built-in 'set' handler
8772 * set [-abCefhmnuvx] [-o option] [argument...]
8773 * set [+abCefhmnuvx] [+o option] [argument...]
8774 * set -- [argument...]
8777 * Implementations shall support the options in both their hyphen and
8778 * plus-sign forms. These options can also be specified as options to sh.
8780 * Write out all variables and their values: set
8781 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8782 * Turn on the -x and -v options: set -xv
8783 * Unset all positional parameters: set --
8784 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8785 * Set the positional parameters to the expansion of x, even if x expands
8786 * with a leading '-' or '+': set -- $x
8788 * So far, we only support "set -- [argument...]" and some of the short names.
8790 static int FAST_FUNC builtin_set(char **argv)
8793 char **pp, **g_argv;
8794 char *arg = *++argv;
8798 for (e = G.top_var; e; e = e->next)
8800 return EXIT_SUCCESS;
8804 if (strcmp(arg, "--") == 0) {
8808 if (arg[0] != '+' && arg[0] != '-')
8810 for (n = 1; arg[n]; ++n) {
8811 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8813 if (arg[n] == 'o' && argv[1])
8816 } while ((arg = *++argv) != NULL);
8817 /* Now argv[0] is 1st argument */
8820 return EXIT_SUCCESS;
8823 /* NB: G.global_argv[0] ($0) is never freed/changed */
8824 g_argv = G.global_argv;
8825 if (G.global_args_malloced) {
8831 G.global_args_malloced = 1;
8832 pp = xzalloc(sizeof(pp[0]) * 2);
8833 pp[0] = g_argv[0]; /* retain $0 */
8836 /* This realloc's G.global_argv */
8837 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8844 return EXIT_SUCCESS;
8846 /* Nothing known, so abort */
8848 bb_error_msg("set: %s: invalid option", arg);
8849 return EXIT_FAILURE;
8852 static int FAST_FUNC builtin_shift(char **argv)
8855 argv = skip_dash_dash(argv);
8859 if (n >= 0 && n < G.global_argc) {
8860 if (G.global_args_malloced) {
8863 free(G.global_argv[m++]);
8866 memmove(&G.global_argv[1], &G.global_argv[n+1],
8867 G.global_argc * sizeof(G.global_argv[0]));
8868 return EXIT_SUCCESS;
8870 return EXIT_FAILURE;
8873 static int FAST_FUNC builtin_source(char **argv)
8875 char *arg_path, *filename;
8878 #if ENABLE_HUSH_FUNCTIONS
8882 argv = skip_dash_dash(argv);
8885 /* bash says: "bash: .: filename argument required" */
8886 return 2; /* bash compat */
8889 if (!strchr(filename, '/')) {
8890 arg_path = find_in_path(filename);
8892 filename = arg_path;
8894 input = fopen_or_warn(filename, "r");
8897 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8898 /* POSIX: non-interactive shell should abort here,
8899 * not merely fail. So far no one complained :)
8901 return EXIT_FAILURE;
8903 close_on_exec_on(fileno(input));
8905 #if ENABLE_HUSH_FUNCTIONS
8906 sv_flg = G.flag_return_in_progress;
8907 /* "we are inside sourced file, ok to use return" */
8908 G.flag_return_in_progress = -1;
8911 save_and_replace_G_args(&sv, argv);
8913 parse_and_run_file(input);
8917 restore_G_args(&sv, argv);
8918 #if ENABLE_HUSH_FUNCTIONS
8919 G.flag_return_in_progress = sv_flg;
8922 return G.last_exitcode;
8925 static int FAST_FUNC builtin_umask(char **argv)
8931 argv = skip_dash_dash(argv);
8933 mode_t old_mask = mask;
8936 rc = bb_parse_mode(argv[0], &mask);
8941 * bash: umask: 'q': invalid symbolic mode operator
8942 * bash: umask: 999: octal number out of range
8944 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8949 printf("%04o\n", (unsigned) mask);
8950 /* fall through and restore mask which we set to 0 */
8954 return !rc; /* rc != 0 - success */
8957 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8958 static int FAST_FUNC builtin_unset(char **argv)
8963 /* "!": do not abort on errors */
8964 /* "+": stop at 1st non-option */
8965 opts = getopt32(argv, "!+vf");
8966 if (opts == (unsigned)-1)
8967 return EXIT_FAILURE;
8969 bb_error_msg("unset: -v and -f are exclusive");
8970 return EXIT_FAILURE;
8976 if (!(opts & 2)) { /* not -f */
8977 if (unset_local_var(*argv)) {
8978 /* unset <nonexistent_var> doesn't fail.
8979 * Error is when one tries to unset RO var.
8980 * Message was printed by unset_local_var. */
8984 #if ENABLE_HUSH_FUNCTIONS
8994 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8995 static int FAST_FUNC builtin_wait(char **argv)
8997 int ret = EXIT_SUCCESS;
9000 argv = skip_dash_dash(argv);
9001 if (argv[0] == NULL) {
9002 /* Don't care about wait results */
9003 /* Note 1: must wait until there are no more children */
9004 /* Note 2: must be interruptible */
9006 * $ sleep 3 & sleep 6 & wait
9011 * $ sleep 3 & sleep 6 & wait
9015 * ^C <-- after ~4 sec from keyboard
9020 sigset_t oldset, allsigs;
9022 /* waitpid is not interruptible by SA_RESTARTed
9023 * signals which we use. Thus, this ugly dance:
9026 /* Make sure possible SIGCHLD is stored in kernel's
9027 * pending signal mask before we call waitpid.
9028 * Or else we may race with SIGCHLD, lose it,
9029 * and get stuck in sigwaitinfo...
9031 sigfillset(&allsigs);
9032 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9034 if (!sigisemptyset(&G.pending_set)) {
9035 /* Crap! we raced with some signal! */
9040 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9041 if (errno == ECHILD) {
9042 sigprocmask(SIG_SETMASK, &oldset, NULL);
9046 /* Wait for SIGCHLD or any other signal */
9047 //sig = sigwaitinfo(&allsigs, NULL);
9048 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9049 /* Note: sigsuspend invokes signal handler */
9050 sigsuspend(&oldset);
9052 sigprocmask(SIG_SETMASK, &oldset, NULL);
9054 /* So, did we get a signal? */
9056 // raise(sig); /* run handler */
9057 sig = check_and_run_traps();
9058 if (sig /*&& sig != SIGCHLD - always true */) {
9063 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9068 /* This is probably buggy wrt interruptible-ness */
9070 pid_t pid = bb_strtou(*argv, NULL, 10);
9072 /* mimic bash message */
9073 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9074 return EXIT_FAILURE;
9076 if (waitpid(pid, &status, 0) == pid) {
9077 if (WIFSIGNALED(status))
9078 ret = 128 + WTERMSIG(status);
9079 else if (WIFEXITED(status))
9080 ret = WEXITSTATUS(status);
9084 bb_perror_msg("wait %s", *argv);
9093 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9094 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9097 def = bb_strtou(argv[1], NULL, 10);
9098 if (errno || def < def_min || argv[2]) {
9099 bb_error_msg("%s: bad arguments", argv[0]);
9107 #if ENABLE_HUSH_LOOPS
9108 static int FAST_FUNC builtin_break(char **argv)
9111 if (G.depth_of_loop == 0) {
9112 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9113 return EXIT_SUCCESS; /* bash compat */
9115 G.flag_break_continue++; /* BC_BREAK = 1 */
9117 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9118 if (depth == UINT_MAX)
9119 G.flag_break_continue = BC_BREAK;
9120 if (G.depth_of_loop < depth)
9121 G.depth_break_continue = G.depth_of_loop;
9123 return EXIT_SUCCESS;
9126 static int FAST_FUNC builtin_continue(char **argv)
9128 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9129 return builtin_break(argv);
9133 #if ENABLE_HUSH_FUNCTIONS
9134 static int FAST_FUNC builtin_return(char **argv)
9138 if (G.flag_return_in_progress != -1) {
9139 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9140 return EXIT_FAILURE; /* bash compat */
9143 G.flag_return_in_progress = 1;
9146 * out of range: wraps around at 256, does not error out
9147 * non-numeric param:
9148 * f() { false; return qwe; }; f; echo $?
9149 * bash: return: qwe: numeric argument required <== we do this
9150 * 255 <== we also do this
9152 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);