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"
88 //config: hush is a small shell (25k). It handles the normal flow control
89 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
90 //config: case/esac. Redirections, here documents, $((arithmetic))
91 //config: and functions are supported.
93 //config: It will compile and work on no-mmu systems.
95 //config: It does not handle select, aliases, tilde expansion,
96 //config: &>file and >&file redirection of stdout+stderr.
98 //config:config HUSH_BASH_COMPAT
99 //config: bool "bash-compatible extensions"
101 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
103 //config:config HUSH_BRACE_EXPANSION
104 //config: bool "Brace expansion"
106 //config: depends on HUSH_BASH_COMPAT
108 //config: Enable {abc,def} extension.
110 //config:config HUSH_INTERACTIVE
111 //config: bool "Interactive mode"
113 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
115 //config: Enable interactive mode (prompt and command editing).
116 //config: Without this, hush simply reads and executes commands
117 //config: from stdin just like a shell script from a file.
118 //config: No prompt, no PS1/PS2 magic shell variables.
120 //config:config HUSH_SAVEHISTORY
121 //config: bool "Save command history to .hush_history"
123 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
125 //config:config HUSH_JOB
126 //config: bool "Job control"
128 //config: depends on HUSH_INTERACTIVE
130 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
131 //config: command (not entire shell), fg/bg builtins work. Without this option,
132 //config: "cmd &" still works by simply spawning a process and immediately
133 //config: prompting for next command (or executing next command in a script),
134 //config: but no separate process group is formed.
136 //config:config HUSH_TICK
137 //config: bool "Support process substitution"
139 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
141 //config: Enable `command` and $(command).
143 //config:config HUSH_IF
144 //config: bool "Support if/then/elif/else/fi"
146 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
148 //config:config HUSH_LOOPS
149 //config: bool "Support for, while and until loops"
151 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
153 //config:config HUSH_CASE
154 //config: bool "Support case ... esac statement"
156 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
158 //config: Enable case ... esac statement. +400 bytes.
160 //config:config HUSH_FUNCTIONS
161 //config: bool "Support funcname() { commands; } syntax"
163 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
165 //config: Enable support for shell functions. +800 bytes.
167 //config:config HUSH_LOCAL
168 //config: bool "local builtin"
170 //config: depends on HUSH_FUNCTIONS
172 //config: Enable support for local variables in functions.
174 //config:config HUSH_RANDOM_SUPPORT
175 //config: bool "Pseudorandom generator and $RANDOM variable"
177 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
179 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
180 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
182 //config:config HUSH_MODE_X
183 //config: bool "Support 'hush -x' option and 'set -x' command"
185 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
187 //config: This instructs hush to print commands before execution.
188 //config: Adds ~300 bytes.
190 //config:config HUSH_ECHO
191 //config: bool "echo builtin"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config:config HUSH_PRINTF
196 //config: bool "printf builtin"
198 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
200 //config:config HUSH_TEST
201 //config: bool "test builtin"
203 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
205 //config:config HUSH_HELP
206 //config: bool "help builtin"
208 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
210 //config:config HUSH_EXPORT
211 //config: bool "export builtin"
213 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
215 //config:config HUSH_EXPORT_N
216 //config: bool "Support 'export -n' option"
218 //config: depends on HUSH_EXPORT
220 //config: export -n unexports variables. It is a bash extension.
222 //config:config HUSH_KILL
223 //config: bool "kill builtin (supports kill %jobspec)"
225 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
227 //config:config HUSH_WAIT
228 //config: bool "wait builtin"
230 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
232 //config:config HUSH_TRAP
233 //config: bool "trap builtin"
235 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
237 //config:config HUSH_TYPE
238 //config: bool "type builtin"
240 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
242 //config:config HUSH_READ
243 //config: bool "read builtin"
245 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
247 //config:config HUSH_SET
248 //config: bool "set builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config:config HUSH_UNSET
253 //config: bool "unset builtin"
255 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
257 //config:config HUSH_ULIMIT
258 //config: bool "ulimit builtin"
260 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
262 //config:config HUSH_UMASK
263 //config: bool "umask builtin"
265 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
267 //config:config HUSH_MEMLEAK
268 //config: bool "memleak builtin (debugging)"
270 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
272 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
273 // APPLET_ODDNAME:name main location suid_type help
274 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
275 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
277 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
278 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
279 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
280 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
282 /* -i (interactive) and -s (read stdin) are also accepted,
283 * but currently do nothing, therefore aren't shown in help.
284 * NOMMU-specific options are not meant to be used by users,
285 * therefore we don't show them either.
287 //usage:#define hush_trivial_usage
288 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
289 //usage:#define hush_full_usage "\n\n"
290 //usage: "Unix shell interpreter"
292 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
293 || defined(__APPLE__) \
295 # include <malloc.h> /* for malloc_trim */
298 /* #include <dmalloc.h> */
300 # include <fnmatch.h>
302 #include <sys/utsname.h> /* for setting $HOSTNAME */
304 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
306 #include "shell_common.h"
309 #if ENABLE_HUSH_RANDOM_SUPPORT
312 # define CLEAR_RANDOM_T(rnd) ((void)0)
314 #ifndef F_DUPFD_CLOEXEC
315 # define F_DUPFD_CLOEXEC F_DUPFD
318 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
322 /* So far, all bash compat is controlled by one config option */
323 /* Separate defines document which part of code implements what */
324 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
325 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
326 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
327 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
328 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
332 #define LEAK_HUNTING 0
333 #define BUILD_AS_NOMMU 0
334 /* Enable/disable sanity checks. Ok to enable in production,
335 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
336 * Keeping 1 for now even in released versions.
339 /* Slightly bigger (+200 bytes), but faster hush.
340 * So far it only enables a trick with counting SIGCHLDs and forks,
341 * which allows us to do fewer waitpid's.
342 * (we can detect a case where neither forks were done nor SIGCHLDs happened
343 * and therefore waitpid will return the same result as last time)
345 #define ENABLE_HUSH_FAST 0
346 /* TODO: implement simplified code for users which do not need ${var%...} ops
347 * So far ${var%...} ops are always enabled:
349 #define ENABLE_HUSH_DOLLAR_OPS 1
354 # undef USE_FOR_NOMMU
357 # define USE_FOR_NOMMU(...) __VA_ARGS__
358 # define USE_FOR_MMU(...)
361 #include "NUM_APPLETS.h"
363 /* STANDALONE does not make sense, and won't compile */
364 # undef CONFIG_FEATURE_SH_STANDALONE
365 # undef ENABLE_FEATURE_SH_STANDALONE
366 # undef IF_FEATURE_SH_STANDALONE
367 # undef IF_NOT_FEATURE_SH_STANDALONE
368 # define ENABLE_FEATURE_SH_STANDALONE 0
369 # define IF_FEATURE_SH_STANDALONE(...)
370 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
373 #if !ENABLE_HUSH_INTERACTIVE
374 # undef ENABLE_FEATURE_EDITING
375 # define ENABLE_FEATURE_EDITING 0
376 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
377 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
378 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
379 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
382 /* Do we support ANY keywords? */
383 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
384 # define HAS_KEYWORDS 1
385 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
386 # define IF_HAS_NO_KEYWORDS(...)
388 # define HAS_KEYWORDS 0
389 # define IF_HAS_KEYWORDS(...)
390 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
393 /* If you comment out one of these below, it will be #defined later
394 * to perform debug printfs to stderr: */
395 #define debug_printf(...) do {} while (0)
396 /* Finer-grained debug switches */
397 #define debug_printf_parse(...) do {} while (0)
398 #define debug_print_tree(a, b) do {} while (0)
399 #define debug_printf_exec(...) do {} while (0)
400 #define debug_printf_env(...) do {} while (0)
401 #define debug_printf_jobs(...) do {} while (0)
402 #define debug_printf_expand(...) do {} while (0)
403 #define debug_printf_varexp(...) do {} while (0)
404 #define debug_printf_glob(...) do {} while (0)
405 #define debug_printf_redir(...) do {} while (0)
406 #define debug_printf_list(...) do {} while (0)
407 #define debug_printf_subst(...) do {} while (0)
408 #define debug_printf_clean(...) do {} while (0)
410 #define ERR_PTR ((void*)(long)1)
412 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
414 #define _SPECIAL_VARS_STR "_*@$!?#"
415 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
416 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
417 #if BASH_PATTERN_SUBST
418 /* Support / and // replace ops */
419 /* Note that // is stored as \ in "encoded" string representation */
420 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
421 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
422 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
424 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
425 # define VAR_SUBST_OPS "%#:-=+?"
426 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
429 #define SPECIAL_VAR_SYMBOL 3
433 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
435 /* This supports saving pointers malloced in vfork child,
436 * to be freed in the parent.
439 typedef struct nommu_save_t {
441 struct variable *old_vars;
443 char **argv_from_re_execing;
456 #if ENABLE_HUSH_LOOPS
463 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
468 /* three pseudo-keywords support contrived "case" syntax: */
469 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
470 RES_MATCH , /* "word)" */
471 RES_CASE_BODY, /* "this command is inside CASE" */
478 typedef struct o_string {
480 int length; /* position where data is appended */
483 /* At least some part of the string was inside '' or "",
484 * possibly empty one: word"", wo''rd etc. */
485 smallint has_quoted_part;
486 smallint has_empty_slot;
487 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
490 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
492 /* Protect newly added chars against globbing
493 * by prepending \ to *, ?, [, \ */
494 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
497 MAYBE_ASSIGNMENT = 0,
498 DEFINITELY_ASSIGNMENT = 1,
500 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
503 /* Used for initialization: o_string foo = NULL_O_STRING; */
504 #define NULL_O_STRING { NULL }
506 #ifndef debug_printf_parse
507 static const char *const assignment_flag[] = {
509 "DEFINITELY_ASSIGNMENT",
515 typedef struct in_str {
517 #if ENABLE_HUSH_INTERACTIVE
518 smallint promptmode; /* 0: PS1, 1: PS2 */
525 /* The descrip member of this structure is only used to make
526 * debugging output pretty */
527 static const struct {
529 signed char default_fd;
532 { O_RDONLY, 0, "<" },
533 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
534 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
535 { O_CREAT|O_RDWR, 1, "<>" },
536 { O_RDONLY, 0, "<<" },
537 /* Should not be needed. Bogus default_fd helps in debugging */
538 /* { O_RDONLY, 77, "<<" }, */
541 struct redir_struct {
542 struct redir_struct *next;
543 char *rd_filename; /* filename */
544 int rd_fd; /* fd to redirect */
545 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
547 smallint rd_type; /* (enum redir_type) */
548 /* note: for heredocs, rd_filename contains heredoc delimiter,
549 * and subsequently heredoc itself; and rd_dup is a bitmask:
550 * bit 0: do we need to trim leading tabs?
551 * bit 1: is heredoc quoted (<<'delim' syntax) ?
554 typedef enum redir_type {
556 REDIRECT_OVERWRITE = 1,
559 REDIRECT_HEREDOC = 4,
560 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
563 REDIRFD_SYNTAX_ERR = -2,
564 REDIRFD_TO_FILE = -1,
565 /* otherwise, rd_fd is redirected to rd_dup */
567 HEREDOC_SKIPTABS = 1,
573 pid_t pid; /* 0 if exited */
574 int assignment_cnt; /* how many argv[i] are assignments? */
575 smallint cmd_type; /* CMD_xxx */
577 #define CMD_SUBSHELL 1
579 /* used for "[[ EXPR ]]" */
580 # define CMD_SINGLEWORD_NOGLOB 2
582 #if ENABLE_HUSH_FUNCTIONS
583 # define CMD_FUNCDEF 3
586 smalluint cmd_exitcode;
587 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
590 char *group_as_string;
592 #if ENABLE_HUSH_FUNCTIONS
593 struct function *child_func;
594 /* This field is used to prevent a bug here:
595 * while...do f1() {a;}; f1; f1() {b;}; f1; done
596 * When we execute "f1() {a;}" cmd, we create new function and clear
597 * cmd->group, cmd->group_as_string, cmd->argv[0].
598 * When we execute "f1() {b;}", we notice that f1 exists,
599 * and that its "parent cmd" struct is still "alive",
600 * we put those fields back into cmd->xxx
601 * (struct function has ->parent_cmd ptr to facilitate that).
602 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
603 * Without this trick, loop would execute a;b;b;b;...
604 * instead of correct sequence a;b;a;b;...
605 * When command is freed, it severs the link
606 * (sets ->child_func->parent_cmd to NULL).
609 char **argv; /* command name and arguments */
610 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
611 * and on execution these are substituted with their values.
612 * Substitution can make _several_ words out of one argv[n]!
613 * Example: argv[0]=='.^C*^C.' here: echo .$*.
614 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
616 struct redir_struct *redirects; /* I/O redirections */
618 /* Is there anything in this command at all? */
619 #define IS_NULL_CMD(cmd) \
620 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
624 int num_cmds; /* total number of commands in pipe */
625 int alive_cmds; /* number of commands running (not exited) */
626 int stopped_cmds; /* number of commands alive, but stopped */
628 unsigned jobid; /* job number */
629 pid_t pgrp; /* process group ID for the job */
630 char *cmdtext; /* name of job */
632 struct command *cmds; /* array of commands in pipe */
633 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
634 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
635 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
637 typedef enum pipe_style {
643 /* Is there anything in this pipe at all? */
644 #define IS_NULL_PIPE(pi) \
645 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
647 /* This holds pointers to the various results of parsing */
648 struct parse_context {
649 /* linked list of pipes */
650 struct pipe *list_head;
651 /* last pipe (being constructed right now) */
653 /* last command in pipe (being constructed right now) */
654 struct command *command;
655 /* last redirect in command->redirects list */
656 struct redir_struct *pending_redirect;
662 smallint ctx_inverted; /* "! cmd | cmd" */
664 smallint ctx_dsemicolon; /* ";;" seen */
666 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
668 /* group we are enclosed in:
669 * example: "if pipe1; pipe2; then pipe3; fi"
670 * when we see "if" or "then", we malloc and copy current context,
671 * and make ->stack point to it. then we parse pipeN.
672 * when closing "then" / fi" / whatever is found,
673 * we move list_head into ->stack->command->group,
674 * copy ->stack into current context, and delete ->stack.
675 * (parsing of { list } and ( list ) doesn't use this method)
677 struct parse_context *stack;
681 /* On program start, environ points to initial environment.
682 * putenv adds new pointers into it, unsetenv removes them.
683 * Neither of these (de)allocates the strings.
684 * setenv allocates new strings in malloc space and does putenv,
685 * and thus setenv is unusable (leaky) for shell's purposes */
686 #define setenv(...) setenv_is_leaky_dont_use()
688 struct variable *next;
689 char *varstr; /* points to "name=" portion */
690 #if ENABLE_HUSH_LOCAL
691 unsigned func_nest_level;
693 int max_len; /* if > 0, name is part of initial env; else name is malloced */
694 smallint flg_export; /* putenv should be done on this var */
695 smallint flg_read_only;
703 #if ENABLE_HUSH_FUNCTIONS
705 struct function *next;
707 struct command *parent_cmd;
710 char *body_as_string;
716 /* set -/+o OPT support. (TODO: make it optional)
717 * bash supports the following opts:
728 * interactive-comments on
746 static const char o_opt_strings[] ALIGN1 =
750 #if ENABLE_HUSH_MODE_X
758 #if ENABLE_HUSH_MODE_X
766 struct FILE_list *next;
772 /* "Globals" within this file */
773 /* Sorted roughly by size (smaller offsets == smaller code) */
775 /* interactive_fd != 0 means we are an interactive shell.
776 * If we are, then saved_tty_pgrp can also be != 0, meaning
777 * that controlling tty is available. With saved_tty_pgrp == 0,
778 * job control still works, but terminal signals
779 * (^C, ^Z, ^Y, ^\) won't work at all, and background
780 * process groups can only be created with "cmd &".
781 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
782 * to give tty to the foreground process group,
783 * and will take it back when the group is stopped (^Z)
786 #if ENABLE_HUSH_INTERACTIVE
787 /* 'interactive_fd' is a fd# open to ctty, if we have one
788 * _AND_ if we decided to act interactively */
792 # define G_interactive_fd (G.interactive_fd)
794 # define G_interactive_fd 0
796 #if ENABLE_FEATURE_EDITING
797 line_input_t *line_input_state;
802 #if ENABLE_HUSH_RANDOM_SUPPORT
808 pid_t saved_tty_pgrp;
809 struct pipe *job_list;
810 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
812 # define G_saved_tty_pgrp 0
814 /* How deeply are we in context where "set -e" is ignored */
816 /* "set -e" rules (do we follow them correctly?):
817 * Exit if pipe, list, or compound command exits with a non-zero status.
818 * Shell does not exit if failed command is part of condition in
819 * if/while, part of && or || list except the last command, any command
820 * in a pipe but the last, or if the command's return value is being
821 * inverted with !. If a compound command other than a subshell returns a
822 * non-zero status because a command failed while -e was being ignored, the
823 * shell does not exit. A trap on ERR, if set, is executed before the shell
824 * exits [ERR is a bashism].
826 * If a compound command or function executes in a context where -e is
827 * ignored, none of the commands executed within are affected by the -e
828 * setting. If a compound command or function sets -e while executing in a
829 * context where -e is ignored, that setting does not have any effect until
830 * the compound command or the command containing the function call completes.
833 char o_opt[NUM_OPT_O];
834 #if ENABLE_HUSH_MODE_X
835 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
839 smallint flag_SIGINT;
840 #if ENABLE_HUSH_LOOPS
841 smallint flag_break_continue;
843 #if ENABLE_HUSH_FUNCTIONS
844 /* 0: outside of a function (or sourced file)
845 * -1: inside of a function, ok to use return builtin
846 * 1: return is invoked, skip all till end of func
848 smallint flag_return_in_progress;
849 # define G_flag_return_in_progress (G.flag_return_in_progress)
851 # define G_flag_return_in_progress 0
853 smallint exiting; /* used to prevent EXIT trap recursion */
854 /* These four support $?, $#, and $1 */
855 smalluint last_exitcode;
856 smalluint last_bg_pid_exitcode;
858 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
859 smalluint global_args_malloced;
860 # define G_global_args_malloced (G.global_args_malloced)
862 # define G_global_args_malloced 0
864 /* how many non-NULL argv's we have. NB: $# + 1 */
868 char *argv0_for_re_execing;
870 #if ENABLE_HUSH_LOOPS
871 unsigned depth_break_continue;
872 unsigned depth_of_loop;
876 struct variable *top_var;
877 char **expanded_assignments;
878 #if ENABLE_HUSH_FUNCTIONS
879 struct function *top_func;
880 # if ENABLE_HUSH_LOCAL
881 struct variable **shadowed_vars_pp;
882 unsigned func_nest_level;
885 /* Signal and trap handling */
887 unsigned count_SIGCHLD;
888 unsigned handled_SIGCHLD;
889 smallint we_have_children;
891 struct FILE_list *FILE_list;
892 /* Which signals have non-DFL handler (even with no traps set)?
893 * Set at the start to:
894 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
895 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
896 * The rest is cleared right before execv syscalls.
897 * Other than these two times, never modified.
899 unsigned special_sig_mask;
901 unsigned fatal_sig_mask;
902 # define G_fatal_sig_mask (G.fatal_sig_mask)
904 # define G_fatal_sig_mask 0
907 char **traps; /* char *traps[NSIG] */
908 # define G_traps G.traps
910 # define G_traps ((char**)NULL)
912 sigset_t pending_set;
913 #if ENABLE_HUSH_MEMLEAK
914 unsigned long memleak_value;
920 #if ENABLE_FEATURE_EDITING
921 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
924 #define G (*ptr_to_globals)
925 /* Not #defining name to G.name - this quickly gets unwieldy
926 * (too many defines). Also, I actually prefer to see when a variable
927 * is global, thus "G." prefix is a useful hint */
928 #define INIT_G() do { \
929 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
930 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
931 sigfillset(&G.sa.sa_mask); \
932 G.sa.sa_flags = SA_RESTART; \
936 /* Function prototypes for builtins */
937 static int builtin_cd(char **argv) FAST_FUNC;
939 static int builtin_echo(char **argv) FAST_FUNC;
941 static int builtin_eval(char **argv) FAST_FUNC;
942 static int builtin_exec(char **argv) FAST_FUNC;
943 static int builtin_exit(char **argv) FAST_FUNC;
944 #if ENABLE_HUSH_EXPORT
945 static int builtin_export(char **argv) FAST_FUNC;
948 static int builtin_fg_bg(char **argv) FAST_FUNC;
949 static int builtin_jobs(char **argv) FAST_FUNC;
952 static int builtin_help(char **argv) FAST_FUNC;
954 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
955 static int builtin_history(char **argv) FAST_FUNC;
957 #if ENABLE_HUSH_LOCAL
958 static int builtin_local(char **argv) FAST_FUNC;
960 #if ENABLE_HUSH_MEMLEAK
961 static int builtin_memleak(char **argv) FAST_FUNC;
963 #if ENABLE_HUSH_PRINTF
964 static int builtin_printf(char **argv) FAST_FUNC;
966 static int builtin_pwd(char **argv) FAST_FUNC;
968 static int builtin_read(char **argv) FAST_FUNC;
971 static int builtin_set(char **argv) FAST_FUNC;
973 static int builtin_shift(char **argv) FAST_FUNC;
974 static int builtin_source(char **argv) FAST_FUNC;
975 #if ENABLE_HUSH_TEST || BASH_TEST2
976 static int builtin_test(char **argv) FAST_FUNC;
979 static int builtin_trap(char **argv) FAST_FUNC;
982 static int builtin_type(char **argv) FAST_FUNC;
984 static int builtin_true(char **argv) FAST_FUNC;
985 #if ENABLE_HUSH_UMASK
986 static int builtin_umask(char **argv) FAST_FUNC;
988 #if ENABLE_HUSH_UNSET
989 static int builtin_unset(char **argv) FAST_FUNC;
992 static int builtin_kill(char **argv) FAST_FUNC;
995 static int builtin_wait(char **argv) FAST_FUNC;
997 #if ENABLE_HUSH_LOOPS
998 static int builtin_break(char **argv) FAST_FUNC;
999 static int builtin_continue(char **argv) FAST_FUNC;
1001 #if ENABLE_HUSH_FUNCTIONS
1002 static int builtin_return(char **argv) FAST_FUNC;
1005 /* Table of built-in functions. They can be forked or not, depending on
1006 * context: within pipes, they fork. As simple commands, they do not.
1007 * When used in non-forking context, they can change global variables
1008 * in the parent shell process. If forked, of course they cannot.
1009 * For example, 'unset foo | whatever' will parse and run, but foo will
1010 * still be set at the end. */
1011 struct built_in_command {
1013 int (*b_function)(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_HELP
1015 const char *b_descr;
1016 # define BLTIN(cmd, func, help) { cmd, func, help }
1018 # define BLTIN(cmd, func, help) { cmd, func }
1022 static const struct built_in_command bltins1[] = {
1023 BLTIN("." , builtin_source , "Run commands in file"),
1024 BLTIN(":" , builtin_true , NULL),
1026 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1028 #if ENABLE_HUSH_LOOPS
1029 BLTIN("break" , builtin_break , "Exit loop"),
1031 BLTIN("cd" , builtin_cd , "Change directory"),
1032 #if ENABLE_HUSH_LOOPS
1033 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1035 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1036 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1037 BLTIN("exit" , builtin_exit , NULL),
1038 #if ENABLE_HUSH_EXPORT
1039 BLTIN("export" , builtin_export , "Set environment variables"),
1042 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1044 #if ENABLE_HUSH_HELP
1045 BLTIN("help" , builtin_help , NULL),
1047 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1048 BLTIN("history" , builtin_history , "Show history"),
1051 BLTIN("jobs" , builtin_jobs , "List jobs"),
1053 #if ENABLE_HUSH_KILL
1054 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1056 #if ENABLE_HUSH_LOCAL
1057 BLTIN("local" , builtin_local , "Set local variables"),
1059 #if ENABLE_HUSH_MEMLEAK
1060 BLTIN("memleak" , builtin_memleak , NULL),
1062 #if ENABLE_HUSH_READ
1063 BLTIN("read" , builtin_read , "Input into variable"),
1065 #if ENABLE_HUSH_FUNCTIONS
1066 BLTIN("return" , builtin_return , "Return from function"),
1069 BLTIN("set" , builtin_set , "Set positional parameters"),
1071 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1073 BLTIN("source" , builtin_source , NULL),
1075 #if ENABLE_HUSH_TRAP
1076 BLTIN("trap" , builtin_trap , "Trap signals"),
1078 BLTIN("true" , builtin_true , NULL),
1079 #if ENABLE_HUSH_TYPE
1080 BLTIN("type" , builtin_type , "Show command type"),
1082 #if ENABLE_HUSH_ULIMIT
1083 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1085 #if ENABLE_HUSH_UMASK
1086 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1088 #if ENABLE_HUSH_UNSET
1089 BLTIN("unset" , builtin_unset , "Unset variables"),
1091 #if ENABLE_HUSH_WAIT
1092 BLTIN("wait" , builtin_wait , "Wait for process"),
1095 /* These builtins won't be used if we are on NOMMU and need to re-exec
1096 * (it's cheaper to run an external program in this case):
1098 static const struct built_in_command bltins2[] = {
1099 #if ENABLE_HUSH_TEST
1100 BLTIN("[" , builtin_test , NULL),
1103 BLTIN("[[" , builtin_test , NULL),
1105 #if ENABLE_HUSH_ECHO
1106 BLTIN("echo" , builtin_echo , NULL),
1108 #if ENABLE_HUSH_PRINTF
1109 BLTIN("printf" , builtin_printf , NULL),
1111 BLTIN("pwd" , builtin_pwd , NULL),
1112 #if ENABLE_HUSH_TEST
1113 BLTIN("test" , builtin_test , NULL),
1121 /* prevent disasters with G.debug_indent < 0 */
1122 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1123 # define debug_enter() (G.debug_indent++)
1124 # define debug_leave() (G.debug_indent--)
1126 # define indent() ((void)0)
1127 # define debug_enter() ((void)0)
1128 # define debug_leave() ((void)0)
1131 #ifndef debug_printf
1132 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1135 #ifndef debug_printf_parse
1136 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1139 #ifndef debug_printf_exec
1140 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1143 #ifndef debug_printf_env
1144 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1147 #ifndef debug_printf_jobs
1148 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1149 # define DEBUG_JOBS 1
1151 # define DEBUG_JOBS 0
1154 #ifndef debug_printf_expand
1155 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1156 # define DEBUG_EXPAND 1
1158 # define DEBUG_EXPAND 0
1161 #ifndef debug_printf_varexp
1162 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1165 #ifndef debug_printf_glob
1166 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 # define DEBUG_GLOB 1
1169 # define DEBUG_GLOB 0
1172 #ifndef debug_printf_redir
1173 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1176 #ifndef debug_printf_list
1177 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1180 #ifndef debug_printf_subst
1181 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1184 #ifndef debug_printf_clean
1185 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1186 # define DEBUG_CLEAN 1
1188 # define DEBUG_CLEAN 0
1192 static void debug_print_strings(const char *prefix, char **vv)
1195 fdprintf(2, "%s:\n", prefix);
1197 fdprintf(2, " '%s'\n", *vv++);
1200 # define debug_print_strings(prefix, vv) ((void)0)
1204 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1207 static void *xxmalloc(int lineno, size_t size)
1209 void *ptr = xmalloc((size + 0xff) & ~0xff);
1210 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1213 static void *xxrealloc(int lineno, void *ptr, size_t size)
1215 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1216 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1219 static char *xxstrdup(int lineno, const char *str)
1221 char *ptr = xstrdup(str);
1222 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1225 static void xxfree(void *ptr)
1227 fdprintf(2, "free %p\n", ptr);
1230 # define xmalloc(s) xxmalloc(__LINE__, s)
1231 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1232 # define xstrdup(s) xxstrdup(__LINE__, s)
1233 # define free(p) xxfree(p)
1237 /* Syntax and runtime errors. They always abort scripts.
1238 * In interactive use they usually discard unparsed and/or unexecuted commands
1239 * and return to the prompt.
1240 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1243 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1244 # define syntax_error(lineno, msg) syntax_error(msg)
1245 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1246 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1247 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1248 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1251 static void die_if_script(unsigned lineno, const char *fmt, ...)
1256 bb_error_msg("hush.c:%u", lineno);
1259 bb_verror_msg(fmt, p, NULL);
1261 if (!G_interactive_fd)
1265 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1268 bb_error_msg("syntax error: %s", msg);
1270 bb_error_msg("syntax error");
1273 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1275 bb_error_msg("syntax error at '%s'", msg);
1278 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1280 bb_error_msg("syntax error: unterminated %s", s);
1283 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1285 char msg[2] = { ch, '\0' };
1286 syntax_error_unterm_str(lineno, msg);
1289 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1295 bb_error_msg("hush.c:%u", lineno);
1297 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1301 # undef die_if_script
1302 # undef syntax_error
1303 # undef syntax_error_at
1304 # undef syntax_error_unterm_ch
1305 # undef syntax_error_unterm_str
1306 # undef syntax_error_unexpected_ch
1308 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1309 # define syntax_error(msg) syntax_error(__LINE__, msg)
1310 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1311 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1312 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1313 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1317 #if ENABLE_HUSH_INTERACTIVE
1318 static void cmdedit_update_prompt(void);
1320 # define cmdedit_update_prompt() ((void)0)
1324 /* Utility functions
1326 /* Replace each \x with x in place, return ptr past NUL. */
1327 static char *unbackslash(char *src)
1329 char *dst = src = strchrnul(src, '\\');
1333 if ((*dst++ = *src++) == '\0')
1339 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1360 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1361 v[count1 + count2] = NULL;
1364 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1368 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1370 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1371 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1374 #define add_strings_to_strings(strings, add, need_to_dup) \
1375 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1378 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1379 static char **add_string_to_strings(char **strings, char *add)
1384 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1387 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1389 char **ptr = add_string_to_strings(strings, add);
1390 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1393 #define add_string_to_strings(strings, add) \
1394 xx_add_string_to_strings(__LINE__, strings, add)
1397 static void free_strings(char **strings)
1411 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1415 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1425 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1429 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1435 /* fd was not open? */
1445 /* Manipulating the list of open FILEs */
1446 static FILE *remember_FILE(FILE *fp)
1449 struct FILE_list *n = xmalloc(sizeof(*n));
1450 n->next = G.FILE_list;
1454 close_on_exec_on(n->fd);
1458 static void fclose_and_forget(FILE *fp)
1460 struct FILE_list **pp = &G.FILE_list;
1462 struct FILE_list *cur = *pp;
1463 if (cur->fp == fp) {
1472 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1474 struct FILE_list *fl = G.FILE_list;
1477 /* We use it only on script files, they are all CLOEXEC */
1478 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1479 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1486 static void restore_redirected_FILEs(void)
1488 struct FILE_list *fl = G.FILE_list;
1490 int should_be = fileno(fl->fp);
1491 if (fl->fd != should_be) {
1492 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1493 xmove_fd(fl->fd, should_be);
1499 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1500 static void close_all_FILE_list(void)
1502 struct FILE_list *fl = G.FILE_list;
1504 /* fclose would also free FILE object.
1505 * It is disastrous if we share memory with a vforked parent.
1506 * I'm not sure we never come here after vfork.
1507 * Therefore just close fd, nothing more.
1509 /*fclose(fl->fp); - unsafe */
1517 /* Helpers for setting new $n and restoring them back
1519 typedef struct save_arg_t {
1523 IF_HUSH_SET(smallint sv_g_malloced;)
1526 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1528 sv->sv_argv0 = argv[0];
1529 sv->sv_g_argv = G.global_argv;
1530 sv->sv_g_argc = G.global_argc;
1531 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1533 argv[0] = G.global_argv[0]; /* retain $0 */
1534 G.global_argv = argv;
1535 IF_HUSH_SET(G.global_args_malloced = 0;)
1537 G.global_argc = 1 + string_array_len(argv + 1);
1540 static void restore_G_args(save_arg_t *sv, char **argv)
1543 if (G.global_args_malloced) {
1544 /* someone ran "set -- arg1 arg2 ...", undo */
1545 char **pp = G.global_argv;
1546 while (*++pp) /* note: does not free $0 */
1548 free(G.global_argv);
1551 argv[0] = sv->sv_argv0;
1552 G.global_argv = sv->sv_g_argv;
1553 G.global_argc = sv->sv_g_argc;
1554 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1558 /* Basic theory of signal handling in shell
1559 * ========================================
1560 * This does not describe what hush does, rather, it is current understanding
1561 * what it _should_ do. If it doesn't, it's a bug.
1562 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1564 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1565 * is finished or backgrounded. It is the same in interactive and
1566 * non-interactive shells, and is the same regardless of whether
1567 * a user trap handler is installed or a shell special one is in effect.
1568 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1569 * backgrounds (i.e. stops) or kills all members of currently running
1572 * Wait builtin is interruptible by signals for which user trap is set
1573 * or by SIGINT in interactive shell.
1575 * Trap handlers will execute even within trap handlers. (right?)
1577 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1578 * except for handlers set to '' (empty string).
1580 * If job control is off, backgrounded commands ("cmd &")
1581 * have SIGINT, SIGQUIT set to SIG_IGN.
1583 * Commands which are run in command substitution ("`cmd`")
1584 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1586 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1587 * by the shell from its parent.
1589 * Signals which differ from SIG_DFL action
1590 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1593 * SIGTERM (interactive): ignore
1594 * SIGHUP (interactive):
1595 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1596 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1597 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1598 * that all pipe members are stopped. Try this in bash:
1599 * while :; do :; done - ^Z does not background it
1600 * (while :; do :; done) - ^Z backgrounds it
1601 * SIGINT (interactive): wait for last pipe, ignore the rest
1602 * of the command line, show prompt. NB: ^C does not send SIGINT
1603 * to interactive shell while shell is waiting for a pipe,
1604 * since shell is bg'ed (is not in foreground process group).
1605 * Example 1: this waits 5 sec, but does not execute ls:
1606 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1607 * Example 2: this does not wait and does not execute ls:
1608 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1609 * Example 3: this does not wait 5 sec, but executes ls:
1610 * "sleep 5; ls -l" + press ^C
1611 * Example 4: this does not wait and does not execute ls:
1612 * "sleep 5 & wait; ls -l" + press ^C
1614 * (What happens to signals which are IGN on shell start?)
1615 * (What happens with signal mask on shell start?)
1617 * Old implementation
1618 * ==================
1619 * We use in-kernel pending signal mask to determine which signals were sent.
1620 * We block all signals which we don't want to take action immediately,
1621 * i.e. we block all signals which need to have special handling as described
1622 * above, and all signals which have traps set.
1623 * After each pipe execution, we extract any pending signals via sigtimedwait()
1626 * unsigned special_sig_mask: a mask of such "special" signals
1627 * sigset_t blocked_set: current blocked signal set
1630 * clear bit in blocked_set unless it is also in special_sig_mask
1631 * "trap 'cmd' SIGxxx":
1632 * set bit in blocked_set (even if 'cmd' is '')
1633 * after [v]fork, if we plan to be a shell:
1634 * unblock signals with special interactive handling
1635 * (child shell is not interactive),
1636 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1637 * after [v]fork, if we plan to exec:
1638 * POSIX says fork clears pending signal mask in child - no need to clear it.
1639 * Restore blocked signal set to one inherited by shell just prior to exec.
1641 * Note: as a result, we do not use signal handlers much. The only uses
1642 * are to count SIGCHLDs
1643 * and to restore tty pgrp on signal-induced exit.
1646 * Standard says "When a subshell is entered, traps that are not being ignored
1647 * are set to the default actions". bash interprets it so that traps which
1648 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1650 * Problem: the above approach makes it unwieldy to catch signals while
1651 * we are in read builtin, or while we read commands from stdin:
1652 * masked signals are not visible!
1654 * New implementation
1655 * ==================
1656 * We record each signal we are interested in by installing signal handler
1657 * for them - a bit like emulating kernel pending signal mask in userspace.
1658 * We are interested in: signals which need to have special handling
1659 * as described above, and all signals which have traps set.
1660 * Signals are recorded in pending_set.
1661 * After each pipe execution, we extract any pending signals
1664 * unsigned special_sig_mask: a mask of shell-special signals.
1665 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1666 * char *traps[sig] if trap for sig is set (even if it's '').
1667 * sigset_t pending_set: set of sigs we received.
1670 * if sig is in special_sig_mask, set handler back to:
1671 * record_pending_signo, or to IGN if it's a tty stop signal
1672 * if sig is in fatal_sig_mask, set handler back to sigexit.
1673 * else: set handler back to SIG_DFL
1674 * "trap 'cmd' SIGxxx":
1675 * set handler to record_pending_signo.
1677 * set handler to SIG_IGN.
1678 * after [v]fork, if we plan to be a shell:
1679 * set signals with special interactive handling to SIG_DFL
1680 * (because child shell is not interactive),
1681 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1682 * after [v]fork, if we plan to exec:
1683 * POSIX says fork clears pending signal mask in child - no need to clear it.
1685 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1686 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1689 * Standard says "When a subshell is entered, traps that are not being ignored
1690 * are set to the default actions". bash interprets it so that traps which
1691 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1694 SPECIAL_INTERACTIVE_SIGS = 0
1699 SPECIAL_JOBSTOP_SIGS = 0
1708 static void record_pending_signo(int sig)
1710 sigaddset(&G.pending_set, sig);
1711 #if ENABLE_HUSH_FAST
1712 if (sig == SIGCHLD) {
1714 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1719 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1721 struct sigaction old_sa;
1723 /* We could use signal() to install handlers... almost:
1724 * except that we need to mask ALL signals while handlers run.
1725 * I saw signal nesting in strace, race window isn't small.
1726 * SA_RESTART is also needed, but in Linux, signal()
1727 * sets SA_RESTART too.
1729 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1730 /* sigfillset(&G.sa.sa_mask); - already done */
1731 /* G.sa.sa_flags = SA_RESTART; - already done */
1732 G.sa.sa_handler = handler;
1733 sigaction(sig, &G.sa, &old_sa);
1734 return old_sa.sa_handler;
1737 static void hush_exit(int exitcode) NORETURN;
1739 static void restore_ttypgrp_and__exit(void) NORETURN;
1740 static void restore_ttypgrp_and__exit(void)
1742 /* xfunc has failed! die die die */
1743 /* no EXIT traps, this is an escape hatch! */
1745 hush_exit(xfunc_error_retval);
1750 /* Needed only on some libc:
1751 * It was observed that on exit(), fgetc'ed buffered data
1752 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1753 * With the net effect that even after fork(), not vfork(),
1754 * exit() in NOEXECed applet in "sh SCRIPT":
1755 * noexec_applet_here
1756 * echo END_OF_SCRIPT
1757 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1758 * This makes "echo END_OF_SCRIPT" executed twice.
1759 * Similar problems can be seen with die_if_script() -> xfunc_die()
1760 * and in `cmd` handling.
1761 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1763 static void fflush_and__exit(void) NORETURN;
1764 static void fflush_and__exit(void)
1767 _exit(xfunc_error_retval);
1770 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1771 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1772 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1773 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1775 /* Restores tty foreground process group, and exits.
1776 * May be called as signal handler for fatal signal
1777 * (will resend signal to itself, producing correct exit state)
1778 * or called directly with -EXITCODE.
1779 * We also call it if xfunc is exiting.
1781 static void sigexit(int sig) NORETURN;
1782 static void sigexit(int sig)
1784 /* Careful: we can end up here after [v]fork. Do not restore
1785 * tty pgrp then, only top-level shell process does that */
1786 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1787 /* Disable all signals: job control, SIGPIPE, etc.
1788 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1790 sigprocmask_allsigs(SIG_BLOCK);
1791 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1794 /* Not a signal, just exit */
1798 kill_myself_with_sig(sig); /* does not return */
1802 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1803 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1807 static sighandler_t pick_sighandler(unsigned sig)
1809 sighandler_t handler = SIG_DFL;
1810 if (sig < sizeof(unsigned)*8) {
1811 unsigned sigmask = (1 << sig);
1815 if (G_fatal_sig_mask & sigmask)
1819 /* sig has special handling? */
1820 if (G.special_sig_mask & sigmask) {
1821 handler = record_pending_signo;
1822 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1823 * in order to ignore them: they will be raised
1824 * in an endless loop when we try to do some
1825 * terminal ioctls! We do have to _ignore_ these.
1827 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1834 /* Restores tty foreground process group, and exits. */
1835 static void hush_exit(int exitcode)
1837 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1838 save_history(G.line_input_state);
1842 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1844 /* argv[0] is unused */
1845 argv[1] = G_traps[0];
1847 G.exiting = 1; /* prevent EXIT trap recursion */
1848 /* Note: G_traps[0] is not cleared!
1849 * "trap" will still show it, if executed
1854 #if ENABLE_FEATURE_CLEAN_UP
1856 struct variable *cur_var;
1857 if (G.cwd != bb_msg_unknown)
1859 cur_var = G.top_var;
1861 struct variable *tmp = cur_var;
1862 if (!cur_var->max_len)
1863 free(cur_var->varstr);
1864 cur_var = cur_var->next;
1872 sigexit(- (exitcode & 0xff));
1879 //TODO: return a mask of ALL handled sigs?
1880 static int check_and_run_traps(void)
1887 if (sigisemptyset(&G.pending_set))
1892 if (sigismember(&G.pending_set, sig)) {
1893 sigdelset(&G.pending_set, sig);
1896 } while (sig < NSIG);
1899 if (G_traps && G_traps[sig]) {
1900 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1901 if (G_traps[sig][0]) {
1902 /* We have user-defined handler */
1903 smalluint save_rcode;
1905 /* argv[0] is unused */
1906 argv[1] = G_traps[sig];
1908 save_rcode = G.last_exitcode;
1910 //FIXME: shouldn't it be set to 128 + sig instead?
1911 G.last_exitcode = save_rcode;
1913 } /* else: "" trap, ignoring signal */
1916 /* not a trap: special action */
1919 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1926 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1927 /* bash is observed to signal whole process groups,
1928 * not individual processes */
1929 for (job = G.job_list; job; job = job->next) {
1932 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1933 if (kill(- job->pgrp, SIGHUP) == 0)
1934 kill(- job->pgrp, SIGCONT);
1939 #if ENABLE_HUSH_FAST
1941 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1943 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1945 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1946 * This simplifies wait builtin a bit.
1950 default: /* ignored: */
1951 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1952 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1954 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1955 * Example: wait is not interrupted by TERM
1956 * in interactive shell, because TERM is ignored.
1965 static const char *get_cwd(int force)
1967 if (force || G.cwd == NULL) {
1968 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1969 * we must not try to free(bb_msg_unknown) */
1970 if (G.cwd == bb_msg_unknown)
1972 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1974 G.cwd = bb_msg_unknown;
1981 * Shell and environment variable support
1983 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1985 struct variable **pp;
1986 struct variable *cur;
1989 while ((cur = *pp) != NULL) {
1990 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1997 static const char* FAST_FUNC get_local_var_value(const char *name)
1999 struct variable **vpp;
2000 unsigned len = strlen(name);
2002 if (G.expanded_assignments) {
2003 char **cpp = G.expanded_assignments;
2006 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2007 return cp + len + 1;
2012 vpp = get_ptr_to_local_var(name, len);
2014 return (*vpp)->varstr + len + 1;
2016 if (strcmp(name, "PPID") == 0)
2017 return utoa(G.root_ppid);
2018 // bash compat: UID? EUID?
2019 #if ENABLE_HUSH_RANDOM_SUPPORT
2020 if (strcmp(name, "RANDOM") == 0)
2021 return utoa(next_random(&G.random_gen));
2026 /* str holds "NAME=VAL" and is expected to be malloced.
2027 * We take ownership of it.
2029 * 0: do not change export flag
2030 * (if creating new variable, flag will be 0)
2031 * 1: set export flag and putenv the variable
2032 * -1: clear export flag and unsetenv the variable
2033 * flg_read_only is set only when we handle -R var=val
2035 #if !BB_MMU && ENABLE_HUSH_LOCAL
2036 /* all params are used */
2037 #elif BB_MMU && ENABLE_HUSH_LOCAL
2038 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2039 set_local_var(str, flg_export, local_lvl)
2040 #elif BB_MMU && !ENABLE_HUSH_LOCAL
2041 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2042 set_local_var(str, flg_export)
2043 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2044 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2045 set_local_var(str, flg_export, flg_read_only)
2047 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2049 struct variable **var_pp;
2050 struct variable *cur;
2051 char *free_me = NULL;
2055 eq_sign = strchr(str, '=');
2056 if (!eq_sign) { /* not expected to ever happen? */
2061 name_len = eq_sign - str + 1; /* including '=' */
2062 var_pp = &G.top_var;
2063 while ((cur = *var_pp) != NULL) {
2064 if (strncmp(cur->varstr, str, name_len) != 0) {
2065 var_pp = &cur->next;
2069 /* We found an existing var with this name */
2070 if (cur->flg_read_only) {
2074 bb_error_msg("%s: readonly variable", str);
2078 if (flg_export == -1) { // "&& cur->flg_export" ?
2079 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2084 #if ENABLE_HUSH_LOCAL
2085 if (cur->func_nest_level < local_lvl) {
2086 /* New variable is declared as local,
2087 * and existing one is global, or local
2088 * from enclosing function.
2089 * Remove and save old one: */
2090 *var_pp = cur->next;
2091 cur->next = *G.shadowed_vars_pp;
2092 *G.shadowed_vars_pp = cur;
2093 /* bash 3.2.33(1) and exported vars:
2095 * # f() { local z=a; env | grep ^z; }
2101 if (cur->flg_export)
2106 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2111 if (cur->max_len != 0) {
2112 if (cur->max_len >= strlen(str)) {
2113 /* This one is from startup env, reuse space */
2114 strcpy(cur->varstr, str);
2119 goto set_str_and_exp;
2121 /* max_len == 0 signifies "malloced" var, which we can
2122 * (and have to) free. But we can't free(cur->varstr) here:
2123 * if cur->flg_export is 1, it is in the environment.
2124 * We should either unsetenv+free, or wait until putenv,
2125 * then putenv(new)+free(old).
2127 free_me = cur->varstr;
2128 goto set_str_and_exp;
2131 /* Not found - create new variable struct */
2132 cur = xzalloc(sizeof(*cur));
2133 #if ENABLE_HUSH_LOCAL
2134 cur->func_nest_level = local_lvl;
2136 cur->next = *var_pp;
2142 cur->flg_read_only = flg_read_only;
2145 if (flg_export == 1)
2146 cur->flg_export = 1;
2147 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2148 cmdedit_update_prompt();
2149 if (cur->flg_export) {
2150 if (flg_export == -1) {
2151 cur->flg_export = 0;
2152 /* unsetenv was already done */
2155 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2156 i = putenv(cur->varstr);
2157 /* only now we can free old exported malloced string */
2166 /* Used at startup and after each cd */
2167 static void set_pwd_var(int exp)
2169 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2170 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2173 static int unset_local_var_len(const char *name, int name_len)
2175 struct variable *cur;
2176 struct variable **var_pp;
2179 return EXIT_SUCCESS;
2180 var_pp = &G.top_var;
2181 while ((cur = *var_pp) != NULL) {
2182 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2183 if (cur->flg_read_only) {
2184 bb_error_msg("%s: readonly variable", name);
2185 return EXIT_FAILURE;
2187 *var_pp = cur->next;
2188 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2189 bb_unsetenv(cur->varstr);
2190 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2191 cmdedit_update_prompt();
2195 return EXIT_SUCCESS;
2197 var_pp = &cur->next;
2199 return EXIT_SUCCESS;
2202 #if ENABLE_HUSH_UNSET
2203 static int unset_local_var(const char *name)
2205 return unset_local_var_len(name, strlen(name));
2209 static void unset_vars(char **strings)
2217 const char *eq = strchrnul(*v, '=');
2218 unset_local_var_len(*v, (int)(eq - *v));
2224 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2225 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2227 char *var = xasprintf("%s=%s", name, val);
2228 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2234 * Helpers for "var1=val1 var2=val2 cmd" feature
2236 static void add_vars(struct variable *var)
2238 struct variable *next;
2242 var->next = G.top_var;
2244 if (var->flg_export) {
2245 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2246 putenv(var->varstr);
2248 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2254 static struct variable *set_vars_and_save_old(char **strings)
2257 struct variable *old = NULL;
2263 struct variable *var_p;
2264 struct variable **var_pp;
2267 eq = strchr(*s, '=');
2269 var_pp = get_ptr_to_local_var(*s, eq - *s);
2271 /* Remove variable from global linked list */
2273 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2274 *var_pp = var_p->next;
2275 /* Add it to returned list */
2279 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2290 static void reinit_unicode_for_hush(void)
2292 /* Unicode support should be activated even if LANG is set
2293 * _during_ shell execution, not only if it was set when
2294 * shell was started. Therefore, re-check LANG every time:
2296 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2297 || ENABLE_UNICODE_USING_LOCALE
2299 const char *s = get_local_var_value("LC_ALL");
2300 if (!s) s = get_local_var_value("LC_CTYPE");
2301 if (!s) s = get_local_var_value("LANG");
2307 * in_str support (strings, and "strings" read from files).
2310 #if ENABLE_HUSH_INTERACTIVE
2311 /* To test correct lineedit/interactive behavior, type from command line:
2317 * It exercises a lot of corner cases.
2319 static void cmdedit_update_prompt(void)
2321 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2322 G.PS1 = get_local_var_value("PS1");
2325 G.PS2 = get_local_var_value("PS2");
2332 static const char *setup_prompt_string(int promptmode)
2334 const char *prompt_str;
2335 debug_printf("setup_prompt_string %d ", promptmode);
2336 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2337 /* Set up the prompt */
2338 if (promptmode == 0) { /* PS1 */
2340 /* bash uses $PWD value, even if it is set by user.
2341 * It uses current dir only if PWD is unset.
2342 * We always use current dir. */
2343 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2348 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2349 debug_printf("prompt_str '%s'\n", prompt_str);
2352 static int get_user_input(struct in_str *i)
2355 const char *prompt_str;
2357 prompt_str = setup_prompt_string(i->promptmode);
2358 # if ENABLE_FEATURE_EDITING
2360 reinit_unicode_for_hush();
2361 if (G.flag_SIGINT) {
2362 /* There was ^C'ed, make it look prettier: */
2366 /* buglet: SIGINT will not make new prompt to appear _at once_,
2367 * only after <Enter>. (^C works immediately) */
2368 r = read_line_input(G.line_input_state, prompt_str,
2369 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2372 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2374 write(STDOUT_FILENO, "^C", 2);
2377 check_and_run_traps();
2378 if (r != 0 && !G.flag_SIGINT)
2380 /* ^C or SIGINT: repeat */
2381 G.last_exitcode = 128 + SIGINT;
2384 /* EOF/error detected */
2386 i->peek_buf[0] = r = EOF;
2389 i->p = G.user_input_buf;
2390 return (unsigned char)*i->p++;
2394 if (i->last_char == '\0' || i->last_char == '\n') {
2395 /* Why check_and_run_traps here? Try this interactively:
2396 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2397 * $ <[enter], repeatedly...>
2398 * Without check_and_run_traps, handler never runs.
2400 check_and_run_traps();
2401 fputs(prompt_str, stdout);
2404 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2406 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2407 * no ^C masking happens during fgetc, no special code for ^C:
2408 * it generates SIGINT as usual.
2410 check_and_run_traps();
2412 G.last_exitcode = 128 + SIGINT;
2419 /* This is the magic location that prints prompts
2420 * and gets data back from the user */
2421 static int fgetc_interactive(struct in_str *i)
2424 /* If it's interactive stdin, get new line. */
2425 if (G_interactive_fd && i->file == stdin) {
2426 /* Returns first char (or EOF), the rest is in i->p[] */
2427 ch = get_user_input(i);
2428 i->promptmode = 1; /* PS2 */
2430 /* Not stdin: script file, sourced file, etc */
2431 do ch = fgetc(i->file); while (ch == '\0');
2436 static inline int fgetc_interactive(struct in_str *i)
2439 do ch = fgetc(i->file); while (ch == '\0');
2442 #endif /* INTERACTIVE */
2444 static int i_getch(struct in_str *i)
2449 /* string-based in_str */
2450 ch = (unsigned char)*i->p;
2459 /* FILE-based in_str */
2461 #if ENABLE_FEATURE_EDITING
2462 /* This can be stdin, check line editing char[] buffer */
2463 if (i->p && *i->p != '\0') {
2464 ch = (unsigned char)*i->p++;
2468 /* peek_buf[] is an int array, not char. Can contain EOF. */
2469 ch = i->peek_buf[0];
2471 int ch2 = i->peek_buf[1];
2472 i->peek_buf[0] = ch2;
2473 if (ch2 == 0) /* very likely, avoid redundant write */
2479 ch = fgetc_interactive(i);
2481 debug_printf("file_get: got '%c' %d\n", ch, ch);
2486 static int i_peek(struct in_str *i)
2491 /* string-based in_str */
2492 /* Doesn't report EOF on NUL. None of the callers care. */
2493 return (unsigned char)*i->p;
2496 /* FILE-based in_str */
2498 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2499 /* This can be stdin, check line editing char[] buffer */
2500 if (i->p && *i->p != '\0')
2501 return (unsigned char)*i->p;
2503 /* peek_buf[] is an int array, not char. Can contain EOF. */
2504 ch = i->peek_buf[0];
2508 /* Need to get a new char */
2509 ch = fgetc_interactive(i);
2510 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2512 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2513 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2519 i->peek_buf[0] = ch;
2520 /*i->peek_buf[1] = 0; - already is */
2524 /* Only ever called if i_peek() was called, and did not return EOF.
2525 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2526 * not end-of-line. Therefore we never need to read a new editing line here.
2528 static int i_peek2(struct in_str *i)
2532 /* There are two cases when i->p[] buffer exists.
2533 * (1) it's a string in_str.
2534 * (2) It's a file, and we have a saved line editing buffer.
2535 * In both cases, we know that i->p[0] exists and not NUL, and
2536 * the peek2 result is in i->p[1].
2539 return (unsigned char)i->p[1];
2541 /* Now we know it is a file-based in_str. */
2543 /* peek_buf[] is an int array, not char. Can contain EOF. */
2544 /* Is there 2nd char? */
2545 ch = i->peek_buf[1];
2547 /* We did not read it yet, get it now */
2548 do ch = fgetc(i->file); while (ch == '\0');
2549 i->peek_buf[1] = ch;
2552 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2556 static void setup_file_in_str(struct in_str *i, FILE *f)
2558 memset(i, 0, sizeof(*i));
2559 /* i->promptmode = 0; - PS1 (memset did it) */
2564 static void setup_string_in_str(struct in_str *i, const char *s)
2566 memset(i, 0, sizeof(*i));
2567 /* i->promptmode = 0; - PS1 (memset did it) */
2568 /*i->file = NULL */;
2576 #define B_CHUNK (32 * sizeof(char*))
2578 static void o_reset_to_empty_unquoted(o_string *o)
2581 o->has_quoted_part = 0;
2586 static void o_free(o_string *o)
2589 memset(o, 0, sizeof(*o));
2592 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2597 static void o_grow_by(o_string *o, int len)
2599 if (o->length + len > o->maxlen) {
2600 o->maxlen += (2 * len) | (B_CHUNK-1);
2601 o->data = xrealloc(o->data, 1 + o->maxlen);
2605 static void o_addchr(o_string *o, int ch)
2607 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2608 if (o->length < o->maxlen) {
2609 /* likely. avoid o_grow_by() call */
2611 o->data[o->length] = ch;
2613 o->data[o->length] = '\0';
2621 /* Valid only if we know o_string is not empty */
2622 static void o_delchr(o_string *o)
2625 o->data[o->length] = '\0';
2629 static void o_addblock(o_string *o, const char *str, int len)
2632 memcpy(&o->data[o->length], str, len);
2634 o->data[o->length] = '\0';
2637 static void o_addstr(o_string *o, const char *str)
2639 o_addblock(o, str, strlen(str));
2643 static void nommu_addchr(o_string *o, int ch)
2649 # define nommu_addchr(o, str) ((void)0)
2652 static void o_addstr_with_NUL(o_string *o, const char *str)
2654 o_addblock(o, str, strlen(str) + 1);
2658 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2659 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2660 * Apparently, on unquoted $v bash still does globbing
2661 * ("v='*.txt'; echo $v" prints all .txt files),
2662 * but NOT brace expansion! Thus, there should be TWO independent
2663 * quoting mechanisms on $v expansion side: one protects
2664 * $v from brace expansion, and other additionally protects "$v" against globbing.
2665 * We have only second one.
2668 #if ENABLE_HUSH_BRACE_EXPANSION
2669 # define MAYBE_BRACES "{}"
2671 # define MAYBE_BRACES ""
2674 /* My analysis of quoting semantics tells me that state information
2675 * is associated with a destination, not a source.
2677 static void o_addqchr(o_string *o, int ch)
2680 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2685 o->data[o->length] = '\\';
2688 o->data[o->length] = ch;
2690 o->data[o->length] = '\0';
2693 static void o_addQchr(o_string *o, int ch)
2696 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2697 && strchr("*?[\\" MAYBE_BRACES, ch)
2700 o->data[o->length] = '\\';
2704 o->data[o->length] = ch;
2706 o->data[o->length] = '\0';
2709 static void o_addqblock(o_string *o, const char *str, int len)
2714 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2715 if (ordinary_cnt > len) /* paranoia */
2717 o_addblock(o, str, ordinary_cnt);
2718 if (ordinary_cnt == len)
2719 return; /* NUL is already added by o_addblock */
2720 str += ordinary_cnt;
2721 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2725 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2727 o->data[o->length] = '\\';
2731 o->data[o->length] = ch;
2734 o->data[o->length] = '\0';
2737 static void o_addQblock(o_string *o, const char *str, int len)
2739 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2740 o_addblock(o, str, len);
2743 o_addqblock(o, str, len);
2746 static void o_addQstr(o_string *o, const char *str)
2748 o_addQblock(o, str, strlen(str));
2751 /* A special kind of o_string for $VAR and `cmd` expansion.
2752 * It contains char* list[] at the beginning, which is grown in 16 element
2753 * increments. Actual string data starts at the next multiple of 16 * (char*).
2754 * list[i] contains an INDEX (int!) into this string data.
2755 * It means that if list[] needs to grow, data needs to be moved higher up
2756 * but list[i]'s need not be modified.
2757 * NB: remembering how many list[i]'s you have there is crucial.
2758 * o_finalize_list() operation post-processes this structure - calculates
2759 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2761 #if DEBUG_EXPAND || DEBUG_GLOB
2762 static void debug_print_list(const char *prefix, o_string *o, int n)
2764 char **list = (char**)o->data;
2765 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2769 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2770 prefix, list, n, string_start, o->length, o->maxlen,
2771 !!(o->o_expflags & EXP_FLAG_GLOB),
2773 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2776 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2777 o->data + (int)(uintptr_t)list[i] + string_start,
2778 o->data + (int)(uintptr_t)list[i] + string_start);
2782 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2784 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2788 # define debug_print_list(prefix, o, n) ((void)0)
2791 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2792 * in list[n] so that it points past last stored byte so far.
2793 * It returns n+1. */
2794 static int o_save_ptr_helper(o_string *o, int n)
2796 char **list = (char**)o->data;
2800 if (!o->has_empty_slot) {
2801 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2802 string_len = o->length - string_start;
2803 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2804 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2805 /* list[n] points to string_start, make space for 16 more pointers */
2806 o->maxlen += 0x10 * sizeof(list[0]);
2807 o->data = xrealloc(o->data, o->maxlen + 1);
2808 list = (char**)o->data;
2809 memmove(list + n + 0x10, list + n, string_len);
2810 o->length += 0x10 * sizeof(list[0]);
2812 debug_printf_list("list[%d]=%d string_start=%d\n",
2813 n, string_len, string_start);
2816 /* We have empty slot at list[n], reuse without growth */
2817 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2818 string_len = o->length - string_start;
2819 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2820 n, string_len, string_start);
2821 o->has_empty_slot = 0;
2823 o->has_quoted_part = 0;
2824 list[n] = (char*)(uintptr_t)string_len;
2828 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2829 static int o_get_last_ptr(o_string *o, int n)
2831 char **list = (char**)o->data;
2832 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2834 return ((int)(uintptr_t)list[n-1]) + string_start;
2837 #if ENABLE_HUSH_BRACE_EXPANSION
2838 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2839 * first, it processes even {a} (no commas), second,
2840 * I didn't manage to make it return strings when they don't match
2841 * existing files. Need to re-implement it.
2845 static int glob_needed(const char *s)
2854 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2860 /* Return pointer to next closing brace or to comma */
2861 static const char *next_brace_sub(const char *cp)
2865 while (*cp != '\0') {
2872 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2878 return *cp != '\0' ? cp : NULL;
2880 /* Recursive brace globber. Note: may garble pattern[]. */
2881 static int glob_brace(char *pattern, o_string *o, int n)
2883 char *new_pattern_buf;
2890 debug_printf_glob("glob_brace('%s')\n", pattern);
2896 if (*begin == '{') {
2897 /* Find the first sub-pattern and at the same time
2898 * find the rest after the closing brace */
2899 next = next_brace_sub(begin);
2901 /* An illegal expression */
2905 /* "{abc}" with no commas - illegal
2906 * brace expr, disregard and skip it */
2912 if (*begin == '\\' && begin[1] != '\0')
2916 debug_printf_glob("begin:%s\n", begin);
2917 debug_printf_glob("next:%s\n", next);
2919 /* Now find the end of the whole brace expression */
2921 while (*rest != '}') {
2922 rest = next_brace_sub(rest);
2924 /* An illegal expression */
2927 debug_printf_glob("rest:%s\n", rest);
2929 rest_len = strlen(++rest) + 1;
2931 /* We are sure the brace expression is well-formed */
2933 /* Allocate working buffer large enough for our work */
2934 new_pattern_buf = xmalloc(strlen(pattern));
2936 /* We have a brace expression. BEGIN points to the opening {,
2937 * NEXT points past the terminator of the first element, and REST
2938 * points past the final }. We will accumulate result names from
2939 * recursive runs for each brace alternative in the buffer using
2944 /* Construct the new glob expression */
2947 mempcpy(new_pattern_buf,
2948 /* We know the prefix for all sub-patterns */
2949 pattern, begin - pattern),
2953 /* Note: glob_brace() may garble new_pattern_buf[].
2954 * That's why we re-copy prefix every time (1st memcpy above).
2956 n = glob_brace(new_pattern_buf, o, n);
2958 /* We saw the last entry */
2962 next = next_brace_sub(next);
2964 free(new_pattern_buf);
2972 memset(&globdata, 0, sizeof(globdata));
2973 gr = glob(pattern, 0, NULL, &globdata);
2974 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2976 if (gr == GLOB_NOMATCH) {
2977 globfree(&globdata);
2978 /* NB: garbles parameter */
2979 unbackslash(pattern);
2980 o_addstr_with_NUL(o, pattern);
2981 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2982 return o_save_ptr_helper(o, n);
2984 if (gr == GLOB_NOSPACE)
2985 bb_error_msg_and_die(bb_msg_memory_exhausted);
2986 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2987 * but we didn't specify it. Paranoia again. */
2988 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2990 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2991 char **argv = globdata.gl_pathv;
2993 o_addstr_with_NUL(o, *argv);
2994 n = o_save_ptr_helper(o, n);
3000 globfree(&globdata);
3004 /* Performs globbing on last list[],
3005 * saving each result as a new list[].
3007 static int perform_glob(o_string *o, int n)
3009 char *pattern, *copy;
3011 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3013 return o_save_ptr_helper(o, n);
3014 pattern = o->data + o_get_last_ptr(o, n);
3015 debug_printf_glob("glob pattern '%s'\n", pattern);
3016 if (!glob_needed(pattern)) {
3017 /* unbackslash last string in o in place, fix length */
3018 o->length = unbackslash(pattern) - o->data;
3019 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3020 return o_save_ptr_helper(o, n);
3023 copy = xstrdup(pattern);
3024 /* "forget" pattern in o */
3025 o->length = pattern - o->data;
3026 n = glob_brace(copy, o, n);
3029 debug_print_list("perform_glob returning", o, n);
3033 #else /* !HUSH_BRACE_EXPANSION */
3036 static int glob_needed(const char *s)
3045 if (*s == '*' || *s == '[' || *s == '?')
3051 /* Performs globbing on last list[],
3052 * saving each result as a new list[].
3054 static int perform_glob(o_string *o, int n)
3060 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3062 return o_save_ptr_helper(o, n);
3063 pattern = o->data + o_get_last_ptr(o, n);
3064 debug_printf_glob("glob pattern '%s'\n", pattern);
3065 if (!glob_needed(pattern)) {
3067 /* unbackslash last string in o in place, fix length */
3068 o->length = unbackslash(pattern) - o->data;
3069 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3070 return o_save_ptr_helper(o, n);
3073 memset(&globdata, 0, sizeof(globdata));
3074 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3075 * If we glob "*.\*" and don't find anything, we need
3076 * to fall back to using literal "*.*", but GLOB_NOCHECK
3077 * will return "*.\*"!
3079 gr = glob(pattern, 0, NULL, &globdata);
3080 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3082 if (gr == GLOB_NOMATCH) {
3083 globfree(&globdata);
3086 if (gr == GLOB_NOSPACE)
3087 bb_error_msg_and_die(bb_msg_memory_exhausted);
3088 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3089 * but we didn't specify it. Paranoia again. */
3090 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3092 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3093 char **argv = globdata.gl_pathv;
3094 /* "forget" pattern in o */
3095 o->length = pattern - o->data;
3097 o_addstr_with_NUL(o, *argv);
3098 n = o_save_ptr_helper(o, n);
3104 globfree(&globdata);
3106 debug_print_list("perform_glob returning", o, n);
3110 #endif /* !HUSH_BRACE_EXPANSION */
3112 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3113 * Otherwise, just finish current list[] and start new */
3114 static int o_save_ptr(o_string *o, int n)
3116 if (o->o_expflags & EXP_FLAG_GLOB) {
3117 /* If o->has_empty_slot, list[n] was already globbed
3118 * (if it was requested back then when it was filled)
3119 * so don't do that again! */
3120 if (!o->has_empty_slot)
3121 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3123 return o_save_ptr_helper(o, n);
3126 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3127 static char **o_finalize_list(o_string *o, int n)
3132 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3134 debug_print_list("finalized", o, n);
3135 debug_printf_expand("finalized n:%d\n", n);
3136 list = (char**)o->data;
3137 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3141 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3146 static void free_pipe_list(struct pipe *pi);
3148 /* Returns pi->next - next pipe in the list */
3149 static struct pipe *free_pipe(struct pipe *pi)
3154 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3155 for (i = 0; i < pi->num_cmds; i++) {
3156 struct command *command;
3157 struct redir_struct *r, *rnext;
3159 command = &pi->cmds[i];
3160 debug_printf_clean(" command %d:\n", i);
3161 if (command->argv) {
3165 for (a = 0, p = command->argv; *p; a++, p++) {
3166 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3169 free_strings(command->argv);
3170 //command->argv = NULL;
3172 /* not "else if": on syntax error, we may have both! */
3173 if (command->group) {
3174 debug_printf_clean(" begin group (cmd_type:%d)\n",
3176 free_pipe_list(command->group);
3177 debug_printf_clean(" end group\n");
3178 //command->group = NULL;
3180 /* else is crucial here.
3181 * If group != NULL, child_func is meaningless */
3182 #if ENABLE_HUSH_FUNCTIONS
3183 else if (command->child_func) {
3184 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3185 command->child_func->parent_cmd = NULL;
3189 free(command->group_as_string);
3190 //command->group_as_string = NULL;
3192 for (r = command->redirects; r; r = rnext) {
3193 debug_printf_clean(" redirect %d%s",
3194 r->rd_fd, redir_table[r->rd_type].descrip);
3195 /* guard against the case >$FOO, where foo is unset or blank */
3196 if (r->rd_filename) {
3197 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3198 free(r->rd_filename);
3199 //r->rd_filename = NULL;
3201 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3205 //command->redirects = NULL;
3207 free(pi->cmds); /* children are an array, they get freed all at once */
3211 //pi->cmdtext = NULL;
3219 static void free_pipe_list(struct pipe *pi)
3223 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3225 debug_printf_clean("pipe followup code %d\n", pi->followup);
3231 /*** Parsing routines ***/
3233 #ifndef debug_print_tree
3234 static void debug_print_tree(struct pipe *pi, int lvl)
3236 static const char *const PIPE[] = {
3242 static const char *RES[] = {
3243 [RES_NONE ] = "NONE" ,
3246 [RES_THEN ] = "THEN" ,
3247 [RES_ELIF ] = "ELIF" ,
3248 [RES_ELSE ] = "ELSE" ,
3251 # if ENABLE_HUSH_LOOPS
3252 [RES_FOR ] = "FOR" ,
3253 [RES_WHILE] = "WHILE",
3254 [RES_UNTIL] = "UNTIL",
3256 [RES_DONE ] = "DONE" ,
3258 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3261 # if ENABLE_HUSH_CASE
3262 [RES_CASE ] = "CASE" ,
3263 [RES_CASE_IN ] = "CASE_IN" ,
3264 [RES_MATCH] = "MATCH",
3265 [RES_CASE_BODY] = "CASE_BODY",
3266 [RES_ESAC ] = "ESAC" ,
3268 [RES_XXXX ] = "XXXX" ,
3269 [RES_SNTX ] = "SNTX" ,
3271 static const char *const CMDTYPE[] = {
3275 # if ENABLE_HUSH_FUNCTIONS
3284 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3285 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3287 while (prn < pi->num_cmds) {
3288 struct command *command = &pi->cmds[prn];
3289 char **argv = command->argv;
3291 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3293 command->assignment_cnt);
3294 if (command->group) {
3295 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3296 CMDTYPE[command->cmd_type],
3299 , " group_as_string:", command->group_as_string
3304 debug_print_tree(command->group, lvl+1);
3308 if (argv) while (*argv) {
3309 fdprintf(2, " '%s'", *argv);
3319 #endif /* debug_print_tree */
3321 static struct pipe *new_pipe(void)
3324 pi = xzalloc(sizeof(struct pipe));
3325 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3329 /* Command (member of a pipe) is complete, or we start a new pipe
3330 * if ctx->command is NULL.
3331 * No errors possible here.
3333 static int done_command(struct parse_context *ctx)
3335 /* The command is really already in the pipe structure, so
3336 * advance the pipe counter and make a new, null command. */
3337 struct pipe *pi = ctx->pipe;
3338 struct command *command = ctx->command;
3340 #if 0 /* Instead we emit error message at run time */
3341 if (ctx->pending_redirect) {
3342 /* For example, "cmd >" (no filename to redirect to) */
3343 die_if_script("syntax error: %s", "invalid redirect");
3344 ctx->pending_redirect = NULL;
3349 if (IS_NULL_CMD(command)) {
3350 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3354 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3355 //debug_print_tree(ctx->list_head, 20);
3357 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3360 /* Only real trickiness here is that the uncommitted
3361 * command structure is not counted in pi->num_cmds. */
3362 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3363 ctx->command = command = &pi->cmds[pi->num_cmds];
3365 memset(command, 0, sizeof(*command));
3366 return pi->num_cmds; /* used only for 0/nonzero check */
3369 static void done_pipe(struct parse_context *ctx, pipe_style type)
3373 debug_printf_parse("done_pipe entered, followup %d\n", type);
3374 /* Close previous command */
3375 not_null = done_command(ctx);
3376 ctx->pipe->followup = type;
3378 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3379 ctx->ctx_inverted = 0;
3380 ctx->pipe->res_word = ctx->ctx_res_w;
3383 /* Without this check, even just <enter> on command line generates
3384 * tree of three NOPs (!). Which is harmless but annoying.
3385 * IOW: it is safe to do it unconditionally. */
3388 || ctx->ctx_res_w == RES_FI
3390 #if ENABLE_HUSH_LOOPS
3391 || ctx->ctx_res_w == RES_DONE
3392 || ctx->ctx_res_w == RES_FOR
3393 || ctx->ctx_res_w == RES_IN
3395 #if ENABLE_HUSH_CASE
3396 || ctx->ctx_res_w == RES_ESAC
3400 debug_printf_parse("done_pipe: adding new pipe: "
3401 "not_null:%d ctx->ctx_res_w:%d\n",
3402 not_null, ctx->ctx_res_w);
3404 ctx->pipe->next = new_p;
3406 /* RES_THEN, RES_DO etc are "sticky" -
3407 * they remain set for pipes inside if/while.
3408 * This is used to control execution.
3409 * RES_FOR and RES_IN are NOT sticky (needed to support
3410 * cases where variable or value happens to match a keyword):
3412 #if ENABLE_HUSH_LOOPS
3413 if (ctx->ctx_res_w == RES_FOR
3414 || ctx->ctx_res_w == RES_IN)
3415 ctx->ctx_res_w = RES_NONE;
3417 #if ENABLE_HUSH_CASE
3418 if (ctx->ctx_res_w == RES_MATCH)
3419 ctx->ctx_res_w = RES_CASE_BODY;
3420 if (ctx->ctx_res_w == RES_CASE)
3421 ctx->ctx_res_w = RES_CASE_IN;
3423 ctx->command = NULL; /* trick done_command below */
3424 /* Create the memory for command, roughly:
3425 * ctx->pipe->cmds = new struct command;
3426 * ctx->command = &ctx->pipe->cmds[0];
3429 //debug_print_tree(ctx->list_head, 10);
3431 debug_printf_parse("done_pipe return\n");
3434 static void initialize_context(struct parse_context *ctx)
3436 memset(ctx, 0, sizeof(*ctx));
3437 ctx->pipe = ctx->list_head = new_pipe();
3438 /* Create the memory for command, roughly:
3439 * ctx->pipe->cmds = new struct command;
3440 * ctx->command = &ctx->pipe->cmds[0];
3445 /* If a reserved word is found and processed, parse context is modified
3446 * and 1 is returned.
3449 struct reserved_combo {
3452 unsigned char assignment_flag;
3456 FLAG_END = (1 << RES_NONE ),
3458 FLAG_IF = (1 << RES_IF ),
3459 FLAG_THEN = (1 << RES_THEN ),
3460 FLAG_ELIF = (1 << RES_ELIF ),
3461 FLAG_ELSE = (1 << RES_ELSE ),
3462 FLAG_FI = (1 << RES_FI ),
3464 # if ENABLE_HUSH_LOOPS
3465 FLAG_FOR = (1 << RES_FOR ),
3466 FLAG_WHILE = (1 << RES_WHILE),
3467 FLAG_UNTIL = (1 << RES_UNTIL),
3468 FLAG_DO = (1 << RES_DO ),
3469 FLAG_DONE = (1 << RES_DONE ),
3470 FLAG_IN = (1 << RES_IN ),
3472 # if ENABLE_HUSH_CASE
3473 FLAG_MATCH = (1 << RES_MATCH),
3474 FLAG_ESAC = (1 << RES_ESAC ),
3476 FLAG_START = (1 << RES_XXXX ),
3479 static const struct reserved_combo* match_reserved_word(o_string *word)
3481 /* Mostly a list of accepted follow-up reserved words.
3482 * FLAG_END means we are done with the sequence, and are ready
3483 * to turn the compound list into a command.
3484 * FLAG_START means the word must start a new compound list.
3486 static const struct reserved_combo reserved_list[] = {
3488 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3489 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3490 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3491 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3492 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3493 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3495 # if ENABLE_HUSH_LOOPS
3496 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3497 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3498 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3499 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3500 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3501 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3503 # if ENABLE_HUSH_CASE
3504 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3505 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3508 const struct reserved_combo *r;
3510 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3511 if (strcmp(word->data, r->literal) == 0)
3516 /* Return 0: not a keyword, 1: keyword
3518 static int reserved_word(o_string *word, struct parse_context *ctx)
3520 # if ENABLE_HUSH_CASE
3521 static const struct reserved_combo reserved_match = {
3522 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3525 const struct reserved_combo *r;
3527 if (word->has_quoted_part)
3529 r = match_reserved_word(word);
3533 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3534 # if ENABLE_HUSH_CASE
3535 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3536 /* "case word IN ..." - IN part starts first MATCH part */
3537 r = &reserved_match;
3540 if (r->flag == 0) { /* '!' */
3541 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3542 syntax_error("! ! command");
3543 ctx->ctx_res_w = RES_SNTX;
3545 ctx->ctx_inverted = 1;
3548 if (r->flag & FLAG_START) {
3549 struct parse_context *old;
3551 old = xmemdup(ctx, sizeof(*ctx));
3552 debug_printf_parse("push stack %p\n", old);
3553 initialize_context(ctx);
3555 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3556 syntax_error_at(word->data);
3557 ctx->ctx_res_w = RES_SNTX;
3560 /* "{...} fi" is ok. "{...} if" is not
3562 * if { echo foo; } then { echo bar; } fi */
3563 if (ctx->command->group)
3564 done_pipe(ctx, PIPE_SEQ);
3567 ctx->ctx_res_w = r->res;
3568 ctx->old_flag = r->flag;
3569 word->o_assignment = r->assignment_flag;
3570 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3572 if (ctx->old_flag & FLAG_END) {
3573 struct parse_context *old;
3575 done_pipe(ctx, PIPE_SEQ);
3576 debug_printf_parse("pop stack %p\n", ctx->stack);
3578 old->command->group = ctx->list_head;
3579 old->command->cmd_type = CMD_NORMAL;
3581 /* At this point, the compound command's string is in
3582 * ctx->as_string... except for the leading keyword!
3583 * Consider this example: "echo a | if true; then echo a; fi"
3584 * ctx->as_string will contain "true; then echo a; fi",
3585 * with "if " remaining in old->as_string!
3589 int len = old->as_string.length;
3590 /* Concatenate halves */
3591 o_addstr(&old->as_string, ctx->as_string.data);
3592 o_free_unsafe(&ctx->as_string);
3593 /* Find where leading keyword starts in first half */
3594 str = old->as_string.data + len;
3595 if (str > old->as_string.data)
3596 str--; /* skip whitespace after keyword */
3597 while (str > old->as_string.data && isalpha(str[-1]))
3599 /* Ugh, we're done with this horrid hack */
3600 old->command->group_as_string = xstrdup(str);
3601 debug_printf_parse("pop, remembering as:'%s'\n",
3602 old->command->group_as_string);
3605 *ctx = *old; /* physical copy */
3610 #endif /* HAS_KEYWORDS */
3612 /* Word is complete, look at it and update parsing context.
3613 * Normal return is 0. Syntax errors return 1.
3614 * Note: on return, word is reset, but not o_free'd!
3616 static int done_word(o_string *word, struct parse_context *ctx)
3618 struct command *command = ctx->command;
3620 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3621 if (word->length == 0 && !word->has_quoted_part) {
3622 debug_printf_parse("done_word return 0: true null, ignored\n");
3626 if (ctx->pending_redirect) {
3627 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3628 * only if run as "bash", not "sh" */
3629 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3631 * ...the word that follows the redirection operator
3632 * shall be subjected to tilde expansion, parameter expansion,
3633 * command substitution, arithmetic expansion, and quote
3634 * removal. Pathname expansion shall not be performed
3635 * on the word by a non-interactive shell; an interactive
3636 * shell may perform it, but shall do so only when
3637 * the expansion would result in one word."
3639 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3640 /* Cater for >\file case:
3641 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3642 * Same with heredocs:
3643 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3645 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3646 unbackslash(ctx->pending_redirect->rd_filename);
3647 /* Is it <<"HEREDOC"? */
3648 if (word->has_quoted_part) {
3649 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3652 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3653 ctx->pending_redirect = NULL;
3656 # if ENABLE_HUSH_CASE
3657 if (ctx->ctx_dsemicolon
3658 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3660 /* already done when ctx_dsemicolon was set to 1: */
3661 /* ctx->ctx_res_w = RES_MATCH; */
3662 ctx->ctx_dsemicolon = 0;
3665 if (!command->argv /* if it's the first word... */
3666 # if ENABLE_HUSH_LOOPS
3667 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3668 && ctx->ctx_res_w != RES_IN
3670 # if ENABLE_HUSH_CASE
3671 && ctx->ctx_res_w != RES_CASE
3674 int reserved = reserved_word(word, ctx);
3675 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3677 o_reset_to_empty_unquoted(word);
3678 debug_printf_parse("done_word return %d\n",
3679 (ctx->ctx_res_w == RES_SNTX));
3680 return (ctx->ctx_res_w == RES_SNTX);
3683 if (strcmp(word->data, "[[") == 0) {
3684 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3690 if (command->group) {
3691 /* "{ echo foo; } echo bar" - bad */
3692 syntax_error_at(word->data);
3693 debug_printf_parse("done_word return 1: syntax error, "
3694 "groups and arglists don't mix\n");
3698 /* If this word wasn't an assignment, next ones definitely
3699 * can't be assignments. Even if they look like ones. */
3700 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3701 && word->o_assignment != WORD_IS_KEYWORD
3703 word->o_assignment = NOT_ASSIGNMENT;
3705 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3706 command->assignment_cnt++;
3707 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3709 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3710 word->o_assignment = MAYBE_ASSIGNMENT;
3712 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3714 if (word->has_quoted_part
3715 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3716 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3717 /* (otherwise it's known to be not empty and is already safe) */
3719 /* exclude "$@" - it can expand to no word despite "" */
3720 char *p = word->data;
3721 while (p[0] == SPECIAL_VAR_SYMBOL
3722 && (p[1] & 0x7f) == '@'
3723 && p[2] == SPECIAL_VAR_SYMBOL
3728 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3729 debug_print_strings("word appended to argv", command->argv);
3732 #if ENABLE_HUSH_LOOPS
3733 if (ctx->ctx_res_w == RES_FOR) {
3734 if (word->has_quoted_part
3735 || !is_well_formed_var_name(command->argv[0], '\0')
3737 /* bash says just "not a valid identifier" */
3738 syntax_error("not a valid identifier in for");
3741 /* Force FOR to have just one word (variable name) */
3742 /* NB: basically, this makes hush see "for v in ..."
3743 * syntax as if it is "for v; in ...". FOR and IN become
3744 * two pipe structs in parse tree. */
3745 done_pipe(ctx, PIPE_SEQ);
3748 #if ENABLE_HUSH_CASE
3749 /* Force CASE to have just one word */
3750 if (ctx->ctx_res_w == RES_CASE) {
3751 done_pipe(ctx, PIPE_SEQ);
3755 o_reset_to_empty_unquoted(word);
3757 debug_printf_parse("done_word return 0\n");
3762 /* Peek ahead in the input to find out if we have a "&n" construct,
3763 * as in "2>&1", that represents duplicating a file descriptor.
3765 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3766 * REDIRFD_SYNTAX_ERR if syntax error,
3767 * REDIRFD_TO_FILE if no & was seen,
3768 * or the number found.
3771 #define parse_redir_right_fd(as_string, input) \
3772 parse_redir_right_fd(input)
3774 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3780 return REDIRFD_TO_FILE;
3782 ch = i_getch(input); /* get the & */
3783 nommu_addchr(as_string, ch);
3786 ch = i_getch(input);
3787 nommu_addchr(as_string, ch);
3788 return REDIRFD_CLOSE;
3792 while (ch != EOF && isdigit(ch)) {
3793 d = d*10 + (ch-'0');
3795 ch = i_getch(input);
3796 nommu_addchr(as_string, ch);
3801 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3803 bb_error_msg("ambiguous redirect");
3804 return REDIRFD_SYNTAX_ERR;
3807 /* Return code is 0 normal, 1 if a syntax error is detected
3809 static int parse_redirect(struct parse_context *ctx,
3812 struct in_str *input)
3814 struct command *command = ctx->command;
3815 struct redir_struct *redir;
3816 struct redir_struct **redirp;
3819 dup_num = REDIRFD_TO_FILE;
3820 if (style != REDIRECT_HEREDOC) {
3821 /* Check for a '>&1' type redirect */
3822 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3823 if (dup_num == REDIRFD_SYNTAX_ERR)
3826 int ch = i_peek(input);
3827 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3828 if (dup_num) { /* <<-... */
3829 ch = i_getch(input);
3830 nommu_addchr(&ctx->as_string, ch);
3835 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3836 int ch = i_peek(input);
3838 /* >|FILE redirect ("clobbering" >).
3839 * Since we do not support "set -o noclobber" yet,
3840 * >| and > are the same for now. Just eat |.
3842 ch = i_getch(input);
3843 nommu_addchr(&ctx->as_string, ch);
3847 /* Create a new redir_struct and append it to the linked list */
3848 redirp = &command->redirects;
3849 while ((redir = *redirp) != NULL) {
3850 redirp = &(redir->next);
3852 *redirp = redir = xzalloc(sizeof(*redir));
3853 /* redir->next = NULL; */
3854 /* redir->rd_filename = NULL; */
3855 redir->rd_type = style;
3856 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3858 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3859 redir_table[style].descrip);
3861 redir->rd_dup = dup_num;
3862 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3863 /* Erik had a check here that the file descriptor in question
3864 * is legit; I postpone that to "run time"
3865 * A "-" representation of "close me" shows up as a -3 here */
3866 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3867 redir->rd_fd, redir->rd_dup);
3869 #if 0 /* Instead we emit error message at run time */
3870 if (ctx->pending_redirect) {
3871 /* For example, "cmd > <file" */
3872 die_if_script("syntax error: %s", "invalid redirect");
3875 /* Set ctx->pending_redirect, so we know what to do at the
3876 * end of the next parsed word. */
3877 ctx->pending_redirect = redir;
3882 /* If a redirect is immediately preceded by a number, that number is
3883 * supposed to tell which file descriptor to redirect. This routine
3884 * looks for such preceding numbers. In an ideal world this routine
3885 * needs to handle all the following classes of redirects...
3886 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3887 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3888 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3889 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3891 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3893 * ... If n is quoted, the number shall not be recognized as part of
3894 * the redirection expression. For example:
3896 * writes the character 2 into file a"
3897 * We are getting it right by setting ->has_quoted_part on any \<char>
3899 * A -1 return means no valid number was found,
3900 * the caller should use the appropriate default for this redirection.
3902 static int redirect_opt_num(o_string *o)
3906 if (o->data == NULL)
3908 num = bb_strtou(o->data, NULL, 10);
3909 if (errno || num < 0)
3911 o_reset_to_empty_unquoted(o);
3916 #define fetch_till_str(as_string, input, word, skip_tabs) \
3917 fetch_till_str(input, word, skip_tabs)
3919 static char *fetch_till_str(o_string *as_string,
3920 struct in_str *input,
3924 o_string heredoc = NULL_O_STRING;
3926 int prev = 0; /* not \ */
3932 ch = i_getch(input);
3934 nommu_addchr(as_string, ch);
3935 if ((ch == '\n' || ch == EOF)
3936 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3938 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3939 heredoc.data[past_EOL] = '\0';
3940 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3941 return heredoc.data;
3943 while (ch == '\n') {
3944 o_addchr(&heredoc, ch);
3947 past_EOL = heredoc.length;
3949 ch = i_getch(input);
3951 nommu_addchr(as_string, ch);
3952 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3956 o_free_unsafe(&heredoc);
3959 o_addchr(&heredoc, ch);
3960 nommu_addchr(as_string, ch);
3961 if (prev == '\\' && ch == '\\')
3962 /* Correctly handle foo\\<eol> (not a line cont.) */
3963 prev = 0; /* not \ */
3969 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3970 * and load them all. There should be exactly heredoc_cnt of them.
3972 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3974 struct pipe *pi = ctx->list_head;
3976 while (pi && heredoc_cnt) {
3978 struct command *cmd = pi->cmds;
3980 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3982 cmd->argv ? cmd->argv[0] : "NONE");
3983 for (i = 0; i < pi->num_cmds; i++) {
3984 struct redir_struct *redir = cmd->redirects;
3986 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3987 i, cmd->argv ? cmd->argv[0] : "NONE");
3989 if (redir->rd_type == REDIRECT_HEREDOC) {
3992 redir->rd_type = REDIRECT_HEREDOC2;
3993 /* redir->rd_dup is (ab)used to indicate <<- */
3994 p = fetch_till_str(&ctx->as_string, input,
3995 redir->rd_filename, redir->rd_dup);
3997 syntax_error("unexpected EOF in here document");
4000 free(redir->rd_filename);
4001 redir->rd_filename = p;
4004 redir = redir->next;
4011 /* Should be 0. If it isn't, it's a parse error */
4013 bb_error_msg_and_die("heredoc BUG 2");
4019 static int run_list(struct pipe *pi);
4021 #define parse_stream(pstring, input, end_trigger) \
4022 parse_stream(input, end_trigger)
4024 static struct pipe *parse_stream(char **pstring,
4025 struct in_str *input,
4029 #if !ENABLE_HUSH_FUNCTIONS
4030 #define parse_group(dest, ctx, input, ch) \
4031 parse_group(ctx, input, ch)
4033 static int parse_group(o_string *dest, struct parse_context *ctx,
4034 struct in_str *input, int ch)
4036 /* dest contains characters seen prior to ( or {.
4037 * Typically it's empty, but for function defs,
4038 * it contains function name (without '()'). */
4039 struct pipe *pipe_list;
4041 struct command *command = ctx->command;
4043 debug_printf_parse("parse_group entered\n");
4044 #if ENABLE_HUSH_FUNCTIONS
4045 if (ch == '(' && !dest->has_quoted_part) {
4047 if (done_word(dest, ctx))
4050 goto skip; /* (... */
4051 if (command->argv[1]) { /* word word ... (... */
4052 syntax_error_unexpected_ch('(');
4055 /* it is "word(..." or "word (..." */
4057 ch = i_getch(input);
4058 while (ch == ' ' || ch == '\t');
4060 syntax_error_unexpected_ch(ch);
4063 nommu_addchr(&ctx->as_string, ch);
4065 ch = i_getch(input);
4066 while (ch == ' ' || ch == '\t' || ch == '\n');
4068 syntax_error_unexpected_ch(ch);
4071 nommu_addchr(&ctx->as_string, ch);
4072 command->cmd_type = CMD_FUNCDEF;
4077 #if 0 /* Prevented by caller */
4078 if (command->argv /* word [word]{... */
4079 || dest->length /* word{... */
4080 || dest->has_quoted_part /* ""{... */
4083 debug_printf_parse("parse_group return 1: "
4084 "syntax error, groups and arglists don't mix\n");
4089 #if ENABLE_HUSH_FUNCTIONS
4095 command->cmd_type = CMD_SUBSHELL;
4097 /* bash does not allow "{echo...", requires whitespace */
4099 if (ch != ' ' && ch != '\t' && ch != '\n'
4100 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4102 syntax_error_unexpected_ch(ch);
4106 ch = i_getch(input);
4107 nommu_addchr(&ctx->as_string, ch);
4113 # define as_string NULL
4115 char *as_string = NULL;
4117 pipe_list = parse_stream(&as_string, input, endch);
4120 o_addstr(&ctx->as_string, as_string);
4122 /* empty ()/{} or parse error? */
4123 if (!pipe_list || pipe_list == ERR_PTR) {
4124 /* parse_stream already emitted error msg */
4127 debug_printf_parse("parse_group return 1: "
4128 "parse_stream returned %p\n", pipe_list);
4131 command->group = pipe_list;
4133 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4134 command->group_as_string = as_string;
4135 debug_printf_parse("end of group, remembering as:'%s'\n",
4136 command->group_as_string);
4140 debug_printf_parse("parse_group return 0\n");
4142 /* command remains "open", available for possible redirects */
4145 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4150 ch = i_getch(input);
4153 ch2 = i_peek(input);
4156 /* backslash+newline, skip it */
4161 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4169 ch2 = i_peek2(input);
4172 /* backslash+newline, skip it */
4178 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4179 /* Subroutines for copying $(...) and `...` things */
4180 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4182 static int add_till_single_quote(o_string *dest, struct in_str *input)
4185 int ch = i_getch(input);
4187 syntax_error_unterm_ch('\'');
4195 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4196 static int add_till_double_quote(o_string *dest, struct in_str *input)
4199 int ch = i_getch(input);
4201 syntax_error_unterm_ch('"');
4206 if (ch == '\\') { /* \x. Copy both chars. */
4208 ch = i_getch(input);
4212 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4217 //if (ch == '$') ...
4220 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4222 * "Within the backquoted style of command substitution, backslash
4223 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4224 * The search for the matching backquote shall be satisfied by the first
4225 * backquote found without a preceding backslash; during this search,
4226 * if a non-escaped backquote is encountered within a shell comment,
4227 * a here-document, an embedded command substitution of the $(command)
4228 * form, or a quoted string, undefined results occur. A single-quoted
4229 * or double-quoted string that begins, but does not end, within the
4230 * "`...`" sequence produces undefined results."
4232 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4234 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4237 int ch = i_getch(input);
4241 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4242 ch = i_getch(input);
4246 && (!in_dquote || ch != '"')
4248 o_addchr(dest, '\\');
4252 syntax_error_unterm_ch('`');
4258 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4259 * quoting and nested ()s.
4260 * "With the $(command) style of command substitution, all characters
4261 * following the open parenthesis to the matching closing parenthesis
4262 * constitute the command. Any valid shell script can be used for command,
4263 * except a script consisting solely of redirections which produces
4264 * unspecified results."
4266 * echo $(echo '(TEST)' BEST) (TEST) BEST
4267 * echo $(echo 'TEST)' BEST) TEST) BEST
4268 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4270 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4271 * can contain arbitrary constructs, just like $(cmd).
4272 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4273 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4275 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4276 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4279 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4280 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4281 char end_char2 = end_ch >> 8;
4283 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4286 ch = i_getch(input);
4288 syntax_error_unterm_ch(end_ch);
4292 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4298 /* we look for closing )) of $((EXPR)) */
4299 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4300 i_getch(input); /* eat second ')' */
4305 if (ch == '(' || ch == '{') {
4306 ch = (ch == '(' ? ')' : '}');
4307 if (!add_till_closing_bracket(dest, input, ch))
4313 if (!add_till_single_quote(dest, input))
4319 if (!add_till_double_quote(dest, input))
4325 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4331 /* \x. Copy verbatim. Important for \(, \) */
4332 ch = i_getch(input);
4334 syntax_error_unterm_ch(')');
4339 /* "backslash+newline", ignore both */
4340 o_delchr(dest); /* undo insertion of '\' */
4350 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4352 /* Return code: 0 for OK, 1 for syntax error */
4354 #define parse_dollar(as_string, dest, input, quote_mask) \
4355 parse_dollar(dest, input, quote_mask)
4356 #define as_string NULL
4358 static int parse_dollar(o_string *as_string,
4360 struct in_str *input, unsigned char quote_mask)
4362 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4364 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4366 ch = i_getch(input);
4367 nommu_addchr(as_string, ch);
4369 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4371 debug_printf_parse(": '%c'\n", ch);
4372 o_addchr(dest, ch | quote_mask);
4374 ch = i_peek_and_eat_bkslash_nl(input);
4375 if (!isalnum(ch) && ch != '_') {
4376 /* End of variable name reached */
4379 ch = i_getch(input);
4380 nommu_addchr(as_string, ch);
4382 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4383 } else if (isdigit(ch)) {
4385 ch = i_getch(input);
4386 nommu_addchr(as_string, ch);
4387 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4388 debug_printf_parse(": '%c'\n", ch);
4389 o_addchr(dest, ch | quote_mask);
4390 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4391 } else switch (ch) {
4393 case '!': /* last bg pid */
4394 case '?': /* last exit code */
4395 case '#': /* number of args */
4396 case '*': /* args */
4397 case '@': /* args */
4398 goto make_one_char_var;
4400 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4402 ch = i_getch(input); /* eat '{' */
4403 nommu_addchr(as_string, ch);
4405 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4406 /* It should be ${?}, or ${#var},
4407 * or even ${?+subst} - operator acting on a special variable,
4408 * or the beginning of variable name.
4411 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4414 syntax_error_unterm_str("${name}");
4415 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4418 nommu_addchr(as_string, ch);
4421 /* It's possible to just call add_till_closing_bracket() at this point.
4422 * However, this regresses some of our testsuite cases
4423 * which check invalid constructs like ${%}.
4424 * Oh well... let's check that the var name part is fine... */
4430 debug_printf_parse(": '%c'\n", ch);
4432 ch = i_getch(input);
4433 nommu_addchr(as_string, ch);
4437 if (!isalnum(ch) && ch != '_') {
4439 unsigned char last_ch;
4440 /* handle parameter expansions
4441 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4443 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4444 goto bad_dollar_syntax;
4446 /* Eat everything until closing '}' (or ':') */
4450 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4452 /* It's ${var:N[:M]} thing */
4453 end_ch = '}' * 0x100 + ':';
4455 if (BASH_PATTERN_SUBST
4458 /* It's ${var/[/]pattern[/repl]} thing */
4459 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4461 nommu_addchr(as_string, '/');
4464 end_ch = '}' * 0x100 + '/';
4470 #if ENABLE_HUSH_DOLLAR_OPS
4471 last_ch = add_till_closing_bracket(dest, input, end_ch);
4472 if (last_ch == 0) /* error? */
4475 #error Simple code to only allow ${var} is not implemented
4478 o_addstr(as_string, dest->data + pos);
4479 o_addchr(as_string, last_ch);
4482 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4483 && (end_ch & 0xff00)
4485 /* close the first block: */
4486 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4487 /* while parsing N from ${var:N[:M]}
4488 * or pattern from ${var/[/]pattern[/repl]} */
4489 if ((end_ch & 0xff) == last_ch) {
4490 /* got ':' or '/'- parse the rest */
4495 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4496 /* it's ${var:N} - emulate :999999999 */
4497 o_addstr(dest, "999999999");
4498 } /* else: it's ${var/[/]pattern} */
4503 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4506 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4510 ch = i_getch(input);
4511 nommu_addchr(as_string, ch);
4512 # if ENABLE_FEATURE_SH_MATH
4513 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4514 ch = i_getch(input);
4515 nommu_addchr(as_string, ch);
4516 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4517 o_addchr(dest, /*quote_mask |*/ '+');
4520 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4521 return 0; /* error */
4523 o_addstr(as_string, dest->data + pos);
4524 o_addchr(as_string, ')');
4525 o_addchr(as_string, ')');
4527 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4531 # if ENABLE_HUSH_TICK
4532 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4533 o_addchr(dest, quote_mask | '`');
4536 if (!add_till_closing_bracket(dest, input, ')'))
4537 return 0; /* error */
4539 o_addstr(as_string, dest->data + pos);
4540 o_addchr(as_string, ')');
4542 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4548 ch = i_getch(input);
4549 nommu_addchr(as_string, ch);
4550 ch = i_peek_and_eat_bkslash_nl(input);
4551 if (isalnum(ch)) { /* it's $_name or $_123 */
4556 /* TODO: $_ and $-: */
4557 /* $_ Shell or shell script name; or last argument of last command
4558 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4559 * but in command's env, set to full pathname used to invoke it */
4560 /* $- Option flags set by set builtin or shell options (-i etc) */
4562 o_addQchr(dest, '$');
4564 debug_printf_parse("parse_dollar return 1 (ok)\n");
4570 # if BASH_PATTERN_SUBST
4571 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4572 encode_string(dest, input, dquote_end, process_bkslash)
4574 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4575 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4576 encode_string(dest, input, dquote_end)
4578 #define as_string NULL
4582 # if BASH_PATTERN_SUBST
4583 /* all parameters are needed, no macro tricks */
4585 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4586 encode_string(as_string, dest, input, dquote_end)
4589 static int encode_string(o_string *as_string,
4591 struct in_str *input,
4593 int process_bkslash)
4595 #if !BASH_PATTERN_SUBST
4596 const int process_bkslash = 1;
4602 ch = i_getch(input);
4604 nommu_addchr(as_string, ch);
4605 if (ch == dquote_end) { /* may be only '"' or EOF */
4606 debug_printf_parse("encode_string return 1 (ok)\n");
4609 /* note: can't move it above ch == dquote_end check! */
4611 syntax_error_unterm_ch('"');
4612 return 0; /* error */
4616 next = i_peek(input);
4618 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4619 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4620 if (process_bkslash && ch == '\\') {
4622 syntax_error("\\<eof>");
4626 * "The backslash retains its special meaning [in "..."]
4627 * only when followed by one of the following characters:
4628 * $, `, ", \, or <newline>. A double quote may be quoted
4629 * within double quotes by preceding it with a backslash."
4630 * NB: in (unquoted) heredoc, above does not apply to ",
4631 * therefore we check for it by "next == dquote_end" cond.
4633 if (next == dquote_end || strchr("$`\\\n", next)) {
4634 ch = i_getch(input); /* eat next */
4636 goto again; /* skip \<newline> */
4637 } /* else: ch remains == '\\', and we double it below: */
4638 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4639 nommu_addchr(as_string, ch);
4643 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4644 debug_printf_parse("encode_string return 0: "
4645 "parse_dollar returned 0 (error)\n");
4650 #if ENABLE_HUSH_TICK
4652 //unsigned pos = dest->length;
4653 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4654 o_addchr(dest, 0x80 | '`');
4655 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4656 return 0; /* error */
4657 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4658 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4662 o_addQchr(dest, ch);
4668 * Scan input until EOF or end_trigger char.
4669 * Return a list of pipes to execute, or NULL on EOF
4670 * or if end_trigger character is met.
4671 * On syntax error, exit if shell is not interactive,
4672 * reset parsing machinery and start parsing anew,
4673 * or return ERR_PTR.
4675 static struct pipe *parse_stream(char **pstring,
4676 struct in_str *input,
4679 struct parse_context ctx;
4680 o_string dest = NULL_O_STRING;
4683 /* Single-quote triggers a bypass of the main loop until its mate is
4684 * found. When recursing, quote state is passed in via dest->o_expflags.
4686 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4687 end_trigger ? end_trigger : 'X');
4690 /* If very first arg is "" or '', dest.data may end up NULL.
4691 * Preventing this: */
4692 o_addchr(&dest, '\0');
4695 /* We used to separate words on $IFS here. This was wrong.
4696 * $IFS is used only for word splitting when $var is expanded,
4697 * here we should use blank chars as separators, not $IFS
4700 if (MAYBE_ASSIGNMENT != 0)
4701 dest.o_assignment = MAYBE_ASSIGNMENT;
4702 initialize_context(&ctx);
4705 const char *is_blank;
4706 const char *is_special;
4710 redir_type redir_style;
4712 ch = i_getch(input);
4713 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4714 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4719 syntax_error_unterm_str("here document");
4722 if (end_trigger == ')') {
4723 syntax_error_unterm_ch('(');
4726 if (end_trigger == '}') {
4727 syntax_error_unterm_ch('{');
4731 if (done_word(&dest, &ctx)) {
4735 done_pipe(&ctx, PIPE_SEQ);
4737 /* If we got nothing... */
4738 /* (this makes bare "&" cmd a no-op.
4739 * bash says: "syntax error near unexpected token '&'") */
4740 if (pi->num_cmds == 0
4741 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4747 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4749 *pstring = ctx.as_string.data;
4751 o_free_unsafe(&ctx.as_string);
4754 debug_printf_parse("parse_stream return %p\n", pi);
4757 nommu_addchr(&ctx.as_string, ch);
4761 next = i_peek(input);
4763 is_special = "{}<>;&|()#'" /* special outside of "str" */
4764 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4765 /* Are { and } special here? */
4766 if (ctx.command->argv /* word [word]{... - non-special */
4767 || dest.length /* word{... - non-special */
4768 || dest.has_quoted_part /* ""{... - non-special */
4769 || (next != ';' /* }; - special */
4770 && next != ')' /* }) - special */
4771 && next != '(' /* {( - special */
4772 && next != '&' /* }& and }&& ... - special */
4773 && next != '|' /* }|| ... - special */
4774 && !strchr(defifs, next) /* {word - non-special */
4777 /* They are not special, skip "{}" */
4780 is_special = strchr(is_special, ch);
4781 is_blank = strchr(defifs, ch);
4783 if (!is_special && !is_blank) { /* ordinary char */
4785 o_addQchr(&dest, ch);
4786 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4787 || dest.o_assignment == WORD_IS_KEYWORD)
4789 && is_well_formed_var_name(dest.data, '=')
4791 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4792 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4798 if (done_word(&dest, &ctx)) {
4802 /* Is this a case when newline is simply ignored?
4804 * "cmd | <newline> cmd ..."
4805 * "case ... in <newline> word) ..."
4807 if (IS_NULL_CMD(ctx.command)
4808 && dest.length == 0 && !dest.has_quoted_part
4810 /* This newline can be ignored. But...
4811 * Without check #1, interactive shell
4812 * ignores even bare <newline>,
4813 * and shows the continuation prompt:
4814 * ps1_prompt$ <enter>
4815 * ps2> _ <=== wrong, should be ps1
4816 * Without check #2, "cmd & <newline>"
4817 * is similarly mistreated.
4818 * (BTW, this makes "cmd & cmd"
4819 * and "cmd && cmd" non-orthogonal.
4820 * Really, ask yourself, why
4821 * "cmd && <newline>" doesn't start
4822 * cmd but waits for more input?
4825 struct pipe *pi = ctx.list_head;
4826 if (pi->num_cmds != 0 /* check #1 */
4827 && pi->followup != PIPE_BG /* check #2 */
4832 /* Treat newline as a command separator. */
4833 done_pipe(&ctx, PIPE_SEQ);
4834 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4836 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4841 dest.o_assignment = MAYBE_ASSIGNMENT;
4842 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4844 /* note: if (is_blank) continue;
4845 * will still trigger for us */
4849 /* "cmd}" or "cmd }..." without semicolon or &:
4850 * } is an ordinary char in this case, even inside { cmd; }
4851 * Pathological example: { ""}; } should exec "}" cmd
4854 if (dest.length != 0 /* word} */
4855 || dest.has_quoted_part /* ""} */
4859 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4860 /* Generally, there should be semicolon: "cmd; }"
4861 * However, bash allows to omit it if "cmd" is
4862 * a group. Examples:
4865 * { echo 0 >&2 | { echo 1; } }
4866 * { while false; do :; done }
4867 * { case a in b) ;; esac }
4869 if (ctx.command->group)
4873 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4874 /* Can't be an end of {cmd}, skip the check */
4875 goto skip_end_trigger;
4876 /* else: } does terminate a group */
4879 if (end_trigger && end_trigger == ch
4880 && (ch != ';' || heredoc_cnt == 0)
4881 #if ENABLE_HUSH_CASE
4883 || ctx.ctx_res_w != RES_MATCH
4884 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4889 /* This is technically valid:
4890 * { cat <<HERE; }; echo Ok
4894 * but we don't support this.
4895 * We require heredoc to be in enclosing {}/(),
4898 syntax_error_unterm_str("here document");
4901 if (done_word(&dest, &ctx)) {
4904 done_pipe(&ctx, PIPE_SEQ);
4905 dest.o_assignment = MAYBE_ASSIGNMENT;
4906 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4907 /* Do we sit outside of any if's, loops or case's? */
4909 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4913 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4915 *pstring = ctx.as_string.data;
4917 o_free_unsafe(&ctx.as_string);
4920 debug_printf_parse("parse_stream return %p: "
4921 "end_trigger char found\n",
4923 return ctx.list_head;
4930 /* Catch <, > before deciding whether this word is
4931 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4934 redir_fd = redirect_opt_num(&dest);
4935 if (done_word(&dest, &ctx)) {
4938 redir_style = REDIRECT_OVERWRITE;
4940 redir_style = REDIRECT_APPEND;
4941 ch = i_getch(input);
4942 nommu_addchr(&ctx.as_string, ch);
4945 else if (next == '(') {
4946 syntax_error(">(process) not supported");
4950 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4952 continue; /* back to top of while (1) */
4954 redir_fd = redirect_opt_num(&dest);
4955 if (done_word(&dest, &ctx)) {
4958 redir_style = REDIRECT_INPUT;
4960 redir_style = REDIRECT_HEREDOC;
4962 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4963 ch = i_getch(input);
4964 nommu_addchr(&ctx.as_string, ch);
4965 } else if (next == '>') {
4966 redir_style = REDIRECT_IO;
4967 ch = i_getch(input);
4968 nommu_addchr(&ctx.as_string, ch);
4971 else if (next == '(') {
4972 syntax_error("<(process) not supported");
4976 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4978 continue; /* back to top of while (1) */
4980 if (dest.length == 0 && !dest.has_quoted_part) {
4981 /* skip "#comment" */
4984 if (ch == EOF || ch == '\n')
4987 /* note: we do not add it to &ctx.as_string */
4989 nommu_addchr(&ctx.as_string, '\n');
4990 continue; /* back to top of while (1) */
4995 /* It's "\<newline>" */
4997 /* Remove trailing '\' from ctx.as_string */
4998 ctx.as_string.data[--ctx.as_string.length] = '\0';
5000 ch = i_getch(input); /* eat it */
5001 continue; /* back to top of while (1) */
5006 if (dest.o_assignment == MAYBE_ASSIGNMENT
5007 /* check that we are not in word in "a=1 2>word b=1": */
5008 && !ctx.pending_redirect
5010 /* ch is a special char and thus this word
5011 * cannot be an assignment */
5012 dest.o_assignment = NOT_ASSIGNMENT;
5013 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5016 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5019 case '#': /* non-comment #: "echo a#b" etc */
5020 o_addQchr(&dest, ch);
5024 syntax_error("\\<eof>");
5027 ch = i_getch(input);
5028 /* note: ch != '\n' (that case does not reach this place) */
5029 o_addchr(&dest, '\\');
5030 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5031 o_addchr(&dest, ch);
5032 nommu_addchr(&ctx.as_string, ch);
5033 /* Example: echo Hello \2>file
5034 * we need to know that word 2 is quoted */
5035 dest.has_quoted_part = 1;
5038 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5039 debug_printf_parse("parse_stream parse error: "
5040 "parse_dollar returned 0 (error)\n");
5045 dest.has_quoted_part = 1;
5046 if (next == '\'' && !ctx.pending_redirect) {
5047 insert_empty_quoted_str_marker:
5048 nommu_addchr(&ctx.as_string, next);
5049 i_getch(input); /* eat second ' */
5050 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5051 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5054 ch = i_getch(input);
5056 syntax_error_unterm_ch('\'');
5059 nommu_addchr(&ctx.as_string, ch);
5062 o_addqchr(&dest, ch);
5067 dest.has_quoted_part = 1;
5068 if (next == '"' && !ctx.pending_redirect)
5069 goto insert_empty_quoted_str_marker;
5070 if (dest.o_assignment == NOT_ASSIGNMENT)
5071 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5072 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5074 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5076 #if ENABLE_HUSH_TICK
5078 USE_FOR_NOMMU(unsigned pos;)
5080 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5081 o_addchr(&dest, '`');
5082 USE_FOR_NOMMU(pos = dest.length;)
5083 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5086 o_addstr(&ctx.as_string, dest.data + pos);
5087 o_addchr(&ctx.as_string, '`');
5089 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5090 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5095 #if ENABLE_HUSH_CASE
5098 if (done_word(&dest, &ctx)) {
5101 done_pipe(&ctx, PIPE_SEQ);
5102 #if ENABLE_HUSH_CASE
5103 /* Eat multiple semicolons, detect
5104 * whether it means something special */
5109 ch = i_getch(input);
5110 nommu_addchr(&ctx.as_string, ch);
5111 if (ctx.ctx_res_w == RES_CASE_BODY) {
5112 ctx.ctx_dsemicolon = 1;
5113 ctx.ctx_res_w = RES_MATCH;
5119 /* We just finished a cmd. New one may start
5120 * with an assignment */
5121 dest.o_assignment = MAYBE_ASSIGNMENT;
5122 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5125 if (done_word(&dest, &ctx)) {
5129 ch = i_getch(input);
5130 nommu_addchr(&ctx.as_string, ch);
5131 done_pipe(&ctx, PIPE_AND);
5133 done_pipe(&ctx, PIPE_BG);
5137 if (done_word(&dest, &ctx)) {
5140 #if ENABLE_HUSH_CASE
5141 if (ctx.ctx_res_w == RES_MATCH)
5142 break; /* we are in case's "word | word)" */
5144 if (next == '|') { /* || */
5145 ch = i_getch(input);
5146 nommu_addchr(&ctx.as_string, ch);
5147 done_pipe(&ctx, PIPE_OR);
5149 /* we could pick up a file descriptor choice here
5150 * with redirect_opt_num(), but bash doesn't do it.
5151 * "echo foo 2| cat" yields "foo 2". */
5156 #if ENABLE_HUSH_CASE
5157 /* "case... in [(]word)..." - skip '(' */
5158 if (ctx.ctx_res_w == RES_MATCH
5159 && ctx.command->argv == NULL /* not (word|(... */
5160 && dest.length == 0 /* not word(... */
5161 && dest.has_quoted_part == 0 /* not ""(... */
5167 if (parse_group(&dest, &ctx, input, ch) != 0) {
5172 #if ENABLE_HUSH_CASE
5173 if (ctx.ctx_res_w == RES_MATCH)
5177 /* proper use of this character is caught by end_trigger:
5178 * if we see {, we call parse_group(..., end_trigger='}')
5179 * and it will match } earlier (not here). */
5180 syntax_error_unexpected_ch(ch);
5181 G.last_exitcode = 2;
5185 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5190 G.last_exitcode = 1;
5193 struct parse_context *pctx;
5194 IF_HAS_KEYWORDS(struct parse_context *p2;)
5196 /* Clean up allocated tree.
5197 * Sample for finding leaks on syntax error recovery path.
5198 * Run it from interactive shell, watch pmap `pidof hush`.
5199 * while if false; then false; fi; do break; fi
5200 * Samples to catch leaks at execution:
5201 * while if (true | { true;}); then echo ok; fi; do break; done
5202 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5206 /* Update pipe/command counts,
5207 * otherwise freeing may miss some */
5208 done_pipe(pctx, PIPE_SEQ);
5209 debug_printf_clean("freeing list %p from ctx %p\n",
5210 pctx->list_head, pctx);
5211 debug_print_tree(pctx->list_head, 0);
5212 free_pipe_list(pctx->list_head);
5213 debug_printf_clean("freed list %p\n", pctx->list_head);
5215 o_free_unsafe(&pctx->as_string);
5217 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5221 IF_HAS_KEYWORDS(pctx = p2;)
5222 } while (HAS_KEYWORDS && pctx);
5235 /*** Execution routines ***/
5237 /* Expansion can recurse, need forward decls: */
5238 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5239 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5240 #define expand_string_to_string(str, do_unbackslash) \
5241 expand_string_to_string(str)
5243 static char *expand_string_to_string(const char *str, int do_unbackslash);
5244 #if ENABLE_HUSH_TICK
5245 static int process_command_subs(o_string *dest, const char *s);
5248 /* expand_strvec_to_strvec() takes a list of strings, expands
5249 * all variable references within and returns a pointer to
5250 * a list of expanded strings, possibly with larger number
5251 * of strings. (Think VAR="a b"; echo $VAR).
5252 * This new list is allocated as a single malloc block.
5253 * NULL-terminated list of char* pointers is at the beginning of it,
5254 * followed by strings themselves.
5255 * Caller can deallocate entire list by single free(list). */
5257 /* A horde of its helpers come first: */
5259 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5261 while (--len >= 0) {
5264 #if ENABLE_HUSH_BRACE_EXPANSION
5265 if (c == '{' || c == '}') {
5266 /* { -> \{, } -> \} */
5268 /* And now we want to add { or } and continue:
5271 * luckily, just falling through achieves this.
5277 /* \z -> \\\z; \<eol> -> \\<eol> */
5282 o_addchr(o, *str++);
5288 /* Store given string, finalizing the word and starting new one whenever
5289 * we encounter IFS char(s). This is used for expanding variable values.
5290 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5291 * Return in *ended_with_ifs:
5292 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5294 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5296 int last_is_ifs = 0;
5301 if (!*str) /* EOL - do not finalize word */
5303 word_len = strcspn(str, G.ifs);
5305 /* We have WORD_LEN leading non-IFS chars */
5306 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5307 o_addblock(output, str, word_len);
5309 /* Protect backslashes against globbing up :)
5310 * Example: "v='\*'; echo b$v" prints "b\*"
5311 * (and does not try to glob on "*")
5313 o_addblock_duplicate_backslash(output, str, word_len);
5314 /*/ Why can't we do it easier? */
5315 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5316 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5320 if (!*str) /* EOL - do not finalize word */
5324 /* We know str here points to at least one IFS char */
5326 str += strspn(str, G.ifs); /* skip IFS chars */
5327 if (!*str) /* EOL - do not finalize word */
5330 /* Start new word... but not always! */
5331 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5332 if (output->has_quoted_part
5333 /* Case "v=' a'; echo $v":
5334 * here nothing precedes the space in $v expansion,
5335 * therefore we should not finish the word
5336 * (IOW: if there *is* word to finalize, only then do it):
5338 || (n > 0 && output->data[output->length - 1])
5340 o_addchr(output, '\0');
5341 debug_print_list("expand_on_ifs", output, n);
5342 n = o_save_ptr(output, n);
5347 *ended_with_ifs = last_is_ifs;
5348 debug_print_list("expand_on_ifs[1]", output, n);
5352 /* Helper to expand $((...)) and heredoc body. These act as if
5353 * they are in double quotes, with the exception that they are not :).
5354 * Just the rules are similar: "expand only $var and `cmd`"
5356 * Returns malloced string.
5357 * As an optimization, we return NULL if expansion is not needed.
5359 #if !BASH_PATTERN_SUBST
5360 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5361 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5362 encode_then_expand_string(str)
5364 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5366 #if !BASH_PATTERN_SUBST
5367 const int do_unbackslash = 1;
5370 struct in_str input;
5371 o_string dest = NULL_O_STRING;
5373 if (!strchr(str, '$')
5374 && !strchr(str, '\\')
5375 #if ENABLE_HUSH_TICK
5376 && !strchr(str, '`')
5382 /* We need to expand. Example:
5383 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5385 setup_string_in_str(&input, str);
5386 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5387 //TODO: error check (encode_string returns 0 on error)?
5388 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5389 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5390 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5391 o_free_unsafe(&dest);
5395 #if ENABLE_FEATURE_SH_MATH
5396 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5398 arith_state_t math_state;
5402 math_state.lookupvar = get_local_var_value;
5403 math_state.setvar = set_local_var_from_halves;
5404 //math_state.endofname = endofname;
5405 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5406 res = arith(&math_state, exp_str ? exp_str : arg);
5409 *errmsg_p = math_state.errmsg;
5410 if (math_state.errmsg)
5411 die_if_script(math_state.errmsg);
5416 #if BASH_PATTERN_SUBST
5417 /* ${var/[/]pattern[/repl]} helpers */
5418 static char *strstr_pattern(char *val, const char *pattern, int *size)
5421 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5422 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5429 /* Optimization: if "*pat" did not match the start of "string",
5430 * we know that "tring", "ring" etc will not match too:
5432 if (pattern[0] == '*')
5437 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5439 char *result = NULL;
5440 unsigned res_len = 0;
5441 unsigned repl_len = strlen(repl);
5445 char *s = strstr_pattern(val, pattern, &size);
5449 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5450 memcpy(result + res_len, val, s - val);
5452 strcpy(result + res_len, repl);
5453 res_len += repl_len;
5454 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5460 if (val[0] && result) {
5461 result = xrealloc(result, res_len + strlen(val) + 1);
5462 strcpy(result + res_len, val);
5463 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5465 debug_printf_varexp("result:'%s'\n", result);
5468 #endif /* BASH_PATTERN_SUBST */
5471 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5473 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5475 const char *val = NULL;
5476 char *to_be_freed = NULL;
5481 char exp_save = exp_save; /* for compiler */
5482 char *exp_saveptr; /* points to expansion operator */
5483 char *exp_word = exp_word; /* for compiler */
5486 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5488 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5490 first_char = arg[0] = arg0 & 0x7f;
5493 if (first_char == '#' /* ${#... */
5494 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5496 /* It must be length operator: ${#var} */
5500 /* Maybe handle parameter expansion */
5501 if (exp_saveptr /* if 2nd char is one of expansion operators */
5502 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5504 /* ${?:0}, ${#[:]%0} etc */
5505 exp_saveptr = var + 1;
5507 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5508 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5510 exp_op = exp_save = *exp_saveptr;
5512 exp_word = exp_saveptr + 1;
5513 if (exp_op == ':') {
5514 exp_op = *exp_word++;
5515 //TODO: try ${var:} and ${var:bogus} in non-bash config
5517 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5519 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5524 *exp_saveptr = '\0';
5525 } /* else: it's not an expansion op, but bare ${var} */
5528 /* Look up the variable in question */
5529 if (isdigit(var[0])) {
5530 /* parse_dollar should have vetted var for us */
5531 int n = xatoi_positive(var);
5532 if (n < G.global_argc)
5533 val = G.global_argv[n];
5534 /* else val remains NULL: $N with too big N */
5538 val = utoa(G.root_pid);
5540 case '!': /* bg pid */
5541 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5543 case '?': /* exitcode */
5544 val = utoa(G.last_exitcode);
5546 case '#': /* argc */
5547 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5550 val = get_local_var_value(var);
5554 /* Handle any expansions */
5555 if (exp_op == 'L') {
5556 reinit_unicode_for_hush();
5557 debug_printf_expand("expand: length(%s)=", val);
5558 val = utoa(val ? unicode_strlen(val) : 0);
5559 debug_printf_expand("%s\n", val);
5560 } else if (exp_op) {
5561 if (exp_op == '%' || exp_op == '#') {
5562 /* Standard-mandated substring removal ops:
5563 * ${parameter%word} - remove smallest suffix pattern
5564 * ${parameter%%word} - remove largest suffix pattern
5565 * ${parameter#word} - remove smallest prefix pattern
5566 * ${parameter##word} - remove largest prefix pattern
5568 * Word is expanded to produce a glob pattern.
5569 * Then var's value is matched to it and matching part removed.
5571 if (val && val[0]) {
5575 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5576 if (exp_op == *exp_word) /* ## or %% */
5578 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5580 exp_word = exp_exp_word;
5581 /* HACK ALERT. We depend here on the fact that
5582 * G.global_argv and results of utoa and get_local_var_value
5583 * are actually in writable memory:
5584 * scan_and_match momentarily stores NULs there. */
5586 loc = scan_and_match(t, exp_word, scan_flags);
5587 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5588 // exp_op, t, exp_word, loc);
5590 if (loc) { /* match was found */
5591 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5592 val = loc; /* take right part */
5594 val = to_be_freed = xstrndup(val, loc - val); /* left */
5598 #if BASH_PATTERN_SUBST
5599 else if (exp_op == '/' || exp_op == '\\') {
5600 /* It's ${var/[/]pattern[/repl]} thing.
5601 * Note that in encoded form it has TWO parts:
5602 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5603 * and if // is used, it is encoded as \:
5604 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5606 /* Empty variable always gives nothing: */
5607 // "v=''; echo ${v/*/w}" prints "", not "w"
5608 if (val && val[0]) {
5609 /* pattern uses non-standard expansion.
5610 * repl should be unbackslashed and globbed
5611 * by the usual expansion rules:
5613 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5614 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5615 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5616 * v='a bz'; echo ${v/a*z/\z} prints "z"
5617 * (note that a*z _pattern_ is never globbed!)
5619 char *pattern, *repl, *t;
5620 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5622 pattern = xstrdup(exp_word);
5623 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5624 *p++ = SPECIAL_VAR_SYMBOL;
5626 p = strchr(p, SPECIAL_VAR_SYMBOL);
5628 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5629 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5630 /* HACK ALERT. We depend here on the fact that
5631 * G.global_argv and results of utoa and get_local_var_value
5632 * are actually in writable memory:
5633 * replace_pattern momentarily stores NULs there. */
5635 to_be_freed = replace_pattern(t,
5637 (repl ? repl : exp_word),
5639 if (to_be_freed) /* at least one replace happened */
5645 #endif /* BASH_PATTERN_SUBST */
5646 else if (exp_op == ':') {
5647 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5648 /* It's ${var:N[:M]} bashism.
5649 * Note that in encoded form it has TWO parts:
5650 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5655 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5658 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5659 *p++ = SPECIAL_VAR_SYMBOL;
5661 p = strchr(p, SPECIAL_VAR_SYMBOL);
5663 len = expand_and_evaluate_arith(exp_word, &errmsg);
5666 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5667 if (len >= 0) { /* bash compat: len < 0 is illegal */
5669 /* negative beg counts from the end */
5670 beg = (arith_t)strlen(val) + beg;
5671 if (beg < 0) /* ${v: -999999} is "" */
5674 debug_printf_varexp("from val:'%s'\n", val);
5675 if (len == 0 || !val || beg >= strlen(val)) {
5679 /* Paranoia. What if user entered 9999999999999
5680 * which fits in arith_t but not int? */
5683 val = to_be_freed = xstrndup(val + beg, len);
5685 debug_printf_varexp("val:'%s'\n", val);
5687 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5689 die_if_script("malformed ${%s:...}", var);
5692 } else { /* one of "-=+?" */
5693 /* Standard-mandated substitution ops:
5694 * ${var?word} - indicate error if unset
5695 * If var is unset, word (or a message indicating it is unset
5696 * if word is null) is written to standard error
5697 * and the shell exits with a non-zero exit status.
5698 * Otherwise, the value of var is substituted.
5699 * ${var-word} - use default value
5700 * If var is unset, word is substituted.
5701 * ${var=word} - assign and use default value
5702 * If var is unset, word is assigned to var.
5703 * In all cases, final value of var is substituted.
5704 * ${var+word} - use alternative value
5705 * If var is unset, null is substituted.
5706 * Otherwise, word is substituted.
5708 * Word is subjected to tilde expansion, parameter expansion,
5709 * command substitution, and arithmetic expansion.
5710 * If word is not needed, it is not expanded.
5712 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5713 * but also treat null var as if it is unset.
5715 int use_word = (!val || ((exp_save == ':') && !val[0]));
5717 use_word = !use_word;
5718 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5719 (exp_save == ':') ? "true" : "false", use_word);
5721 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5723 exp_word = to_be_freed;
5724 if (exp_op == '?') {
5725 /* mimic bash message */
5726 die_if_script("%s: %s",
5728 exp_word[0] ? exp_word : "parameter null or not set"
5730 //TODO: how interactive bash aborts expansion mid-command?
5735 if (exp_op == '=') {
5736 /* ${var=[word]} or ${var:=[word]} */
5737 if (isdigit(var[0]) || var[0] == '#') {
5738 /* mimic bash message */
5739 die_if_script("$%s: cannot assign in this way", var);
5742 char *new_var = xasprintf("%s=%s", var, val);
5743 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5747 } /* one of "-=+?" */
5749 *exp_saveptr = exp_save;
5755 *to_be_freed_pp = to_be_freed;
5759 /* Expand all variable references in given string, adding words to list[]
5760 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5761 * to be filled). This routine is extremely tricky: has to deal with
5762 * variables/parameters with whitespace, $* and $@, and constructs like
5763 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5764 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5766 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5767 * expansion of right-hand side of assignment == 1-element expand.
5769 char cant_be_null = 0; /* only bit 0x80 matters */
5770 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5773 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5774 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5775 debug_print_list("expand_vars_to_list", output, n);
5776 n = o_save_ptr(output, n);
5777 debug_print_list("expand_vars_to_list[0]", output, n);
5779 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5781 char *to_be_freed = NULL;
5782 const char *val = NULL;
5783 #if ENABLE_HUSH_TICK
5784 o_string subst_result = NULL_O_STRING;
5786 #if ENABLE_FEATURE_SH_MATH
5787 char arith_buf[sizeof(arith_t)*3 + 2];
5791 o_addchr(output, '\0');
5792 n = o_save_ptr(output, n);
5796 o_addblock(output, arg, p - arg);
5797 debug_print_list("expand_vars_to_list[1]", output, n);
5799 p = strchr(p, SPECIAL_VAR_SYMBOL);
5801 /* Fetch special var name (if it is indeed one of them)
5802 * and quote bit, force the bit on if singleword expansion -
5803 * important for not getting v=$@ expand to many words. */
5804 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5806 /* Is this variable quoted and thus expansion can't be null?
5807 * "$@" is special. Even if quoted, it can still
5808 * expand to nothing (not even an empty string),
5809 * thus it is excluded. */
5810 if ((first_ch & 0x7f) != '@')
5811 cant_be_null |= first_ch;
5813 switch (first_ch & 0x7f) {
5814 /* Highest bit in first_ch indicates that var is double-quoted */
5818 if (!G.global_argv[1])
5821 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5822 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5823 while (G.global_argv[i]) {
5824 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5825 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5826 if (G.global_argv[i++][0] && G.global_argv[i]) {
5827 /* this argv[] is not empty and not last:
5828 * put terminating NUL, start new word */
5829 o_addchr(output, '\0');
5830 debug_print_list("expand_vars_to_list[2]", output, n);
5831 n = o_save_ptr(output, n);
5832 debug_print_list("expand_vars_to_list[3]", output, n);
5836 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5837 * and in this case should treat it like '$*' - see 'else...' below */
5838 if (first_ch == ('@'|0x80) /* quoted $@ */
5839 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5842 o_addQstr(output, G.global_argv[i]);
5843 if (++i >= G.global_argc)
5845 o_addchr(output, '\0');
5846 debug_print_list("expand_vars_to_list[4]", output, n);
5847 n = o_save_ptr(output, n);
5849 } else { /* quoted $* (or v="$@" case): add as one word */
5851 o_addQstr(output, G.global_argv[i]);
5852 if (!G.global_argv[++i])
5855 o_addchr(output, G.ifs[0]);
5857 output->has_quoted_part = 1;
5861 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5862 /* "Empty variable", used to make "" etc to not disappear */
5863 output->has_quoted_part = 1;
5865 cant_be_null = 0x80;
5867 #if ENABLE_HUSH_TICK
5868 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5869 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5871 /* Can't just stuff it into output o_string,
5872 * expanded result may need to be globbed
5874 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5875 G.last_exitcode = process_command_subs(&subst_result, arg);
5876 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5877 val = subst_result.data;
5880 #if ENABLE_FEATURE_SH_MATH
5881 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5884 arg++; /* skip '+' */
5885 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5886 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5887 res = expand_and_evaluate_arith(arg, NULL);
5888 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5889 sprintf(arith_buf, ARITH_FMT, res);
5895 val = expand_one_var(&to_be_freed, arg, &p);
5896 IF_HUSH_TICK(store_val:)
5897 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5898 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5899 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5900 if (val && val[0]) {
5901 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5904 } else { /* quoted $VAR, val will be appended below */
5905 output->has_quoted_part = 1;
5906 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5907 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5910 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5912 if (val && val[0]) {
5913 o_addQstr(output, val);
5917 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5918 * Do the check to avoid writing to a const string. */
5919 if (*p != SPECIAL_VAR_SYMBOL)
5920 *p = SPECIAL_VAR_SYMBOL;
5922 #if ENABLE_HUSH_TICK
5923 o_free(&subst_result);
5926 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5930 o_addchr(output, '\0');
5931 n = o_save_ptr(output, n);
5933 debug_print_list("expand_vars_to_list[a]", output, n);
5934 /* this part is literal, and it was already pre-quoted
5935 * if needed (much earlier), do not use o_addQstr here! */
5936 o_addstr_with_NUL(output, arg);
5937 debug_print_list("expand_vars_to_list[b]", output, n);
5938 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5939 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5942 /* allow to reuse list[n] later without re-growth */
5943 output->has_empty_slot = 1;
5945 o_addchr(output, '\0');
5951 static char **expand_variables(char **argv, unsigned expflags)
5955 o_string output = NULL_O_STRING;
5957 output.o_expflags = expflags;
5961 n = expand_vars_to_list(&output, n, *argv);
5964 debug_print_list("expand_variables", &output, n);
5966 /* output.data (malloced in one block) gets returned in "list" */
5967 list = o_finalize_list(&output, n);
5968 debug_print_strings("expand_variables[1]", list);
5972 static char **expand_strvec_to_strvec(char **argv)
5974 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5978 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5980 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5984 /* Used for expansion of right hand of assignments,
5985 * $((...)), heredocs, variable espansion parts.
5987 * NB: should NOT do globbing!
5988 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5990 static char *expand_string_to_string(const char *str, int do_unbackslash)
5992 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5993 const int do_unbackslash = 1;
5995 char *argv[2], **list;
5997 debug_printf_expand("string_to_string<='%s'\n", str);
5998 /* This is generally an optimization, but it also
5999 * handles "", which otherwise trips over !list[0] check below.
6000 * (is this ever happens that we actually get str="" here?)
6002 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6003 //TODO: Can use on strings with \ too, just unbackslash() them?
6004 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6005 return xstrdup(str);
6008 argv[0] = (char*)str;
6010 list = expand_variables(argv, do_unbackslash
6011 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6012 : EXP_FLAG_SINGLEWORD
6015 if (!list[0] || list[1])
6016 bb_error_msg_and_die("BUG in varexp2");
6017 /* actually, just move string 2*sizeof(char*) bytes back */
6018 overlapping_strcpy((char*)list, list[0]);
6020 unbackslash((char*)list);
6021 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6025 /* Used for "eval" builtin and case string */
6026 static char* expand_strvec_to_string(char **argv)
6030 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6031 /* Convert all NULs to spaces */
6036 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6037 bb_error_msg_and_die("BUG in varexp3");
6038 /* bash uses ' ' regardless of $IFS contents */
6043 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6044 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6048 static char **expand_assignments(char **argv, int count)
6053 G.expanded_assignments = p = NULL;
6054 /* Expand assignments into one string each */
6055 for (i = 0; i < count; i++) {
6056 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6058 G.expanded_assignments = NULL;
6063 static void switch_off_special_sigs(unsigned mask)
6066 while ((mask >>= 1) != 0) {
6070 #if ENABLE_HUSH_TRAP
6072 if (G_traps[sig] && !G_traps[sig][0])
6073 /* trap is '', has to remain SIG_IGN */
6076 G_traps[sig] = NULL;
6079 /* We are here only if no trap or trap was not '' */
6080 install_sighandler(sig, SIG_DFL);
6086 void re_execute_shell(char ***to_free, const char *s,
6087 char *g_argv0, char **g_argv,
6088 char **builtin_argv) NORETURN;
6090 static void reset_traps_to_defaults(void)
6092 /* This function is always called in a child shell
6093 * after fork (not vfork, NOMMU doesn't use this function).
6095 IF_HUSH_TRAP(unsigned sig;)
6098 /* Child shells are not interactive.
6099 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6100 * Testcase: (while :; do :; done) + ^Z should background.
6101 * Same goes for SIGTERM, SIGHUP, SIGINT.
6103 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6104 if (!G_traps && !mask)
6105 return; /* already no traps and no special sigs */
6107 /* Switch off special sigs */
6108 switch_off_special_sigs(mask);
6109 # if ENABLE_HUSH_JOB
6110 G_fatal_sig_mask = 0;
6112 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6113 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6114 * remain set in G.special_sig_mask */
6116 # if ENABLE_HUSH_TRAP
6120 /* Reset all sigs to default except ones with empty traps */
6121 for (sig = 0; sig < NSIG; sig++) {
6123 continue; /* no trap: nothing to do */
6124 if (!G_traps[sig][0])
6125 continue; /* empty trap: has to remain SIG_IGN */
6126 /* sig has non-empty trap, reset it: */
6128 G_traps[sig] = NULL;
6129 /* There is no signal for trap 0 (EXIT) */
6132 install_sighandler(sig, pick_sighandler(sig));
6139 static void re_execute_shell(char ***to_free, const char *s,
6140 char *g_argv0, char **g_argv,
6141 char **builtin_argv) NORETURN;
6142 static void re_execute_shell(char ***to_free, const char *s,
6143 char *g_argv0, char **g_argv,
6144 char **builtin_argv)
6146 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6147 /* delims + 2 * (number of bytes in printed hex numbers) */
6148 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6149 char *heredoc_argv[4];
6150 struct variable *cur;
6151 # if ENABLE_HUSH_FUNCTIONS
6152 struct function *funcp;
6156 unsigned long long empty_trap_mask;
6158 if (!g_argv0) { /* heredoc */
6159 argv = heredoc_argv;
6160 argv[0] = (char *) G.argv0_for_re_execing;
6161 argv[1] = (char *) "-<";
6162 argv[2] = (char *) s;
6164 pp = &argv[3]; /* used as pointer to empty environment */
6170 if (pp) while (*pp++)
6173 empty_trap_mask = 0;
6176 for (sig = 1; sig < NSIG; sig++) {
6177 if (G_traps[sig] && !G_traps[sig][0])
6178 empty_trap_mask |= 1LL << sig;
6182 sprintf(param_buf, NOMMU_HACK_FMT
6183 , (unsigned) G.root_pid
6184 , (unsigned) G.root_ppid
6185 , (unsigned) G.last_bg_pid
6186 , (unsigned) G.last_exitcode
6189 IF_HUSH_LOOPS(, G.depth_of_loop)
6191 # undef NOMMU_HACK_FMT
6192 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6193 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6196 for (cur = G.top_var; cur; cur = cur->next) {
6197 if (!cur->flg_export || cur->flg_read_only)
6200 # if ENABLE_HUSH_FUNCTIONS
6201 for (funcp = G.top_func; funcp; funcp = funcp->next)
6207 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6208 *pp++ = (char *) G.argv0_for_re_execing;
6210 for (cur = G.top_var; cur; cur = cur->next) {
6211 if (strcmp(cur->varstr, hush_version_str) == 0)
6213 if (cur->flg_read_only) {
6214 *pp++ = (char *) "-R";
6215 *pp++ = cur->varstr;
6216 } else if (!cur->flg_export) {
6217 *pp++ = (char *) "-V";
6218 *pp++ = cur->varstr;
6221 # if ENABLE_HUSH_FUNCTIONS
6222 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6223 *pp++ = (char *) "-F";
6224 *pp++ = funcp->name;
6225 *pp++ = funcp->body_as_string;
6228 /* We can pass activated traps here. Say, -Tnn:trap_string
6230 * However, POSIX says that subshells reset signals with traps
6232 * I tested bash-3.2 and it not only does that with true subshells
6233 * of the form ( list ), but with any forked children shells.
6234 * I set trap "echo W" WINCH; and then tried:
6236 * { echo 1; sleep 20; echo 2; } &
6237 * while true; do echo 1; sleep 20; echo 2; break; done &
6238 * true | { echo 1; sleep 20; echo 2; } | cat
6240 * In all these cases sending SIGWINCH to the child shell
6241 * did not run the trap. If I add trap "echo V" WINCH;
6242 * _inside_ group (just before echo 1), it works.
6244 * I conclude it means we don't need to pass active traps here.
6246 *pp++ = (char *) "-c";
6249 while (*++builtin_argv)
6250 *pp++ = *builtin_argv;
6251 *pp++ = (char *) "";
6256 /* *pp = NULL; - is already there */
6260 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6261 /* Don't propagate SIG_IGN to the child */
6262 if (SPECIAL_JOBSTOP_SIGS != 0)
6263 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6264 execve(bb_busybox_exec_path, argv, pp);
6265 /* Fallback. Useful for init=/bin/hush usage etc */
6266 if (argv[0][0] == '/')
6267 execve(argv[0], argv, pp);
6268 xfunc_error_retval = 127;
6269 bb_error_msg_and_die("can't re-execute the shell");
6271 #endif /* !BB_MMU */
6274 static int run_and_free_list(struct pipe *pi);
6276 /* Executing from string: eval, sh -c '...'
6277 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6278 * end_trigger controls how often we stop parsing
6279 * NUL: parse all, execute, return
6280 * ';': parse till ';' or newline, execute, repeat till EOF
6282 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6284 /* Why we need empty flag?
6285 * An obscure corner case "false; ``; echo $?":
6286 * empty command in `` should still set $? to 0.
6287 * But we can't just set $? to 0 at the start,
6288 * this breaks "false; echo `echo $?`" case.
6292 struct pipe *pipe_list;
6294 #if ENABLE_HUSH_INTERACTIVE
6295 if (end_trigger == ';')
6296 inp->promptmode = 0; /* PS1 */
6298 pipe_list = parse_stream(NULL, inp, end_trigger);
6299 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6300 /* If we are in "big" script
6301 * (not in `cmd` or something similar)...
6303 if (pipe_list == ERR_PTR && end_trigger == ';') {
6304 /* Discard cached input (rest of line) */
6305 int ch = inp->last_char;
6306 while (ch != EOF && ch != '\n') {
6307 //bb_error_msg("Discarded:'%c'", ch);
6312 /* This stream isn't empty */
6316 if (!pipe_list && empty)
6317 G.last_exitcode = 0;
6320 debug_print_tree(pipe_list, 0);
6321 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6322 run_and_free_list(pipe_list);
6324 if (G_flag_return_in_progress == 1)
6329 static void parse_and_run_string(const char *s)
6331 struct in_str input;
6332 setup_string_in_str(&input, s);
6333 parse_and_run_stream(&input, '\0');
6336 static void parse_and_run_file(FILE *f)
6338 struct in_str input;
6339 setup_file_in_str(&input, f);
6340 parse_and_run_stream(&input, ';');
6343 #if ENABLE_HUSH_TICK
6344 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6349 char **to_free = NULL;
6353 pid = BB_MMU ? xfork() : xvfork();
6354 if (pid == 0) { /* child */
6355 disable_restore_tty_pgrp_on_exit();
6356 /* Process substitution is not considered to be usual
6357 * 'command execution'.
6358 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6365 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6366 close(channel[0]); /* NB: close _first_, then move fd! */
6367 xmove_fd(channel[1], 1);
6368 /* Prevent it from trying to handle ctrl-z etc */
6369 IF_HUSH_JOB(G.run_list_level = 1;)
6370 # if ENABLE_HUSH_TRAP
6371 /* Awful hack for `trap` or $(trap).
6373 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6374 * contains an example where "trap" is executed in a subshell:
6376 * save_traps=$(trap)
6378 * eval "$save_traps"
6380 * Standard does not say that "trap" in subshell shall print
6381 * parent shell's traps. It only says that its output
6382 * must have suitable form, but then, in the above example
6383 * (which is not supposed to be normative), it implies that.
6385 * bash (and probably other shell) does implement it
6386 * (traps are reset to defaults, but "trap" still shows them),
6387 * but as a result, "trap" logic is hopelessly messed up:
6390 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6391 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6392 * # true | trap <--- trap is in subshell - no output (ditto)
6393 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6394 * trap -- 'echo Ho' SIGWINCH
6395 * # echo `(trap)` <--- in subshell in subshell - output
6396 * trap -- 'echo Ho' SIGWINCH
6397 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6398 * trap -- 'echo Ho' SIGWINCH
6400 * The rules when to forget and when to not forget traps
6401 * get really complex and nonsensical.
6403 * Our solution: ONLY bare $(trap) or `trap` is special.
6405 s = skip_whitespace(s);
6406 if (is_prefixed_with(s, "trap")
6407 && skip_whitespace(s + 4)[0] == '\0'
6409 static const char *const argv[] = { NULL, NULL };
6410 builtin_trap((char**)argv);
6411 fflush_all(); /* important */
6416 reset_traps_to_defaults();
6417 parse_and_run_string(s);
6418 _exit(G.last_exitcode);
6420 /* We re-execute after vfork on NOMMU. This makes this script safe:
6421 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6422 * huge=`cat BIG` # was blocking here forever
6425 re_execute_shell(&to_free,
6435 # if ENABLE_HUSH_FAST
6437 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6438 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6439 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6441 enable_restore_tty_pgrp_on_exit();
6446 return remember_FILE(xfdopen_for_read(channel[0]));
6449 /* Return code is exit status of the process that is run. */
6450 static int process_command_subs(o_string *dest, const char *s)
6453 struct in_str pipe_str;
6455 int status, ch, eol_cnt;
6457 fp = generate_stream_from_string(s, &pid);
6459 /* Now send results of command back into original context */
6460 setup_file_in_str(&pipe_str, fp);
6462 while ((ch = i_getch(&pipe_str)) != EOF) {
6468 o_addchr(dest, '\n');
6471 o_addQchr(dest, ch);
6474 debug_printf("done reading from `cmd` pipe, closing it\n");
6475 fclose_and_forget(fp);
6476 /* We need to extract exitcode. Test case
6477 * "true; echo `sleep 1; false` $?"
6479 safe_waitpid(pid, &status, 0);
6480 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6481 return WEXITSTATUS(status);
6483 #endif /* ENABLE_HUSH_TICK */
6486 static void setup_heredoc(struct redir_struct *redir)
6488 struct fd_pair pair;
6491 /* the _body_ of heredoc (misleading field name) */
6492 const char *heredoc = redir->rd_filename;
6499 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6500 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6504 len = strlen(heredoc);
6506 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6508 xmove_fd(pair.rd, redir->rd_fd);
6510 /* Try writing without forking. Newer kernels have
6511 * dynamically growing pipes. Must use non-blocking write! */
6514 written = write(pair.wr, heredoc, len);
6525 ndelay_off(pair.wr);
6527 /* Okay, pipe buffer was not big enough */
6528 /* Note: we must not create a stray child (bastard? :)
6529 * for the unsuspecting parent process. Child creates a grandchild
6530 * and exits before parent execs the process which consumes heredoc
6531 * (that exec happens after we return from this function) */
6538 disable_restore_tty_pgrp_on_exit();
6539 pid = BB_MMU ? xfork() : xvfork();
6543 close(redir->rd_fd); /* read side of the pipe */
6545 full_write(pair.wr, heredoc, len); /* may loop or block */
6548 /* Delegate blocking writes to another process */
6549 xmove_fd(pair.wr, STDOUT_FILENO);
6550 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6554 #if ENABLE_HUSH_FAST
6556 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6558 enable_restore_tty_pgrp_on_exit();
6564 wait(NULL); /* wait till child has died */
6570 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6571 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6574 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6578 if (sq) while (sq[i].orig_fd >= 0) {
6579 /* If we collide with an already moved fd... */
6580 if (fd == sq[i].moved_to) {
6581 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6582 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6583 if (sq[i].moved_to < 0) /* what? */
6587 if (fd == sq[i].orig_fd) {
6588 /* Example: echo Hello >/dev/null 1>&2 */
6589 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6595 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6597 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6598 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6599 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6600 if (sq[i].moved_to < 0 && errno != EBADF)
6602 sq[i+1].orig_fd = -1; /* end marker */
6606 /* fd: redirect wants this fd to be used (e.g. 3>file).
6607 * Move all conflicting internally used fds,
6608 * and remember them so that we can restore them later.
6610 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6612 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6615 #if ENABLE_HUSH_INTERACTIVE
6616 if (fd != 0 && fd == G.interactive_fd) {
6617 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6618 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6619 return 1; /* "we closed fd" */
6622 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6623 * (1) Redirect in a forked child. No need to save FILEs' fds,
6624 * we aren't going to use them anymore, ok to trash.
6625 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6626 * but how are we doing to restore them?
6627 * "fileno(fd) = new_fd" can't be done.
6632 /* If this one of script's fds? */
6633 if (save_FILEs_on_redirect(fd, avoid_fd))
6634 return 1; /* yes. "we closed fd" */
6636 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6637 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6638 return 0; /* "we did not close fd" */
6641 static void restore_redirects(struct squirrel *sq)
6646 while (sq[i].orig_fd >= 0) {
6647 if (sq[i].moved_to >= 0) {
6648 /* We simply die on error */
6649 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6650 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6652 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6653 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6654 close(sq[i].orig_fd);
6661 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6663 restore_redirected_FILEs();
6666 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6667 * and stderr if they are redirected. */
6668 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6671 struct redir_struct *redir;
6673 for (redir = prog->redirects; redir; redir = redir->next) {
6674 if (redir->rd_type == REDIRECT_HEREDOC2) {
6675 /* "rd_fd<<HERE" case */
6676 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6677 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6679 debug_printf_parse("set heredoc '%s'\n",
6680 redir->rd_filename);
6681 setup_heredoc(redir);
6685 if (redir->rd_dup == REDIRFD_TO_FILE) {
6686 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6688 if (redir->rd_filename == NULL) {
6691 * "cmd >" (no filename)
6692 * "cmd > <file" (2nd redirect starts too early)
6694 die_if_script("syntax error: %s", "invalid redirect");
6697 mode = redir_table[redir->rd_type].mode;
6698 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6699 openfd = open_or_warn(p, mode);
6702 /* Error message from open_or_warn can be lost
6703 * if stderr has been redirected, but bash
6704 * and ash both lose it as well
6705 * (though zsh doesn't!)
6710 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6711 openfd = redir->rd_dup;
6714 if (openfd != redir->rd_fd) {
6715 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6716 if (openfd == REDIRFD_CLOSE) {
6717 /* "rd_fd >&-" means "close me" */
6719 /* ^^^ optimization: saving may already
6720 * have closed it. If not... */
6721 close(redir->rd_fd);
6724 xdup2(openfd, redir->rd_fd);
6725 if (redir->rd_dup == REDIRFD_TO_FILE)
6726 /* "rd_fd > FILE" */
6728 /* else: "rd_fd > rd_dup" */
6735 static char *find_in_path(const char *arg)
6738 const char *PATH = get_local_var_value("PATH");
6744 const char *end = strchrnul(PATH, ':');
6745 int sz = end - PATH; /* must be int! */
6749 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6751 /* We have xxx::yyyy in $PATH,
6752 * it means "use current dir" */
6755 if (access(ret, F_OK) == 0)
6768 static const struct built_in_command *find_builtin_helper(const char *name,
6769 const struct built_in_command *x,
6770 const struct built_in_command *end)
6773 if (strcmp(name, x->b_cmd) != 0) {
6777 debug_printf_exec("found builtin '%s'\n", name);
6782 static const struct built_in_command *find_builtin1(const char *name)
6784 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6786 static const struct built_in_command *find_builtin(const char *name)
6788 const struct built_in_command *x = find_builtin1(name);
6791 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6794 #if ENABLE_HUSH_FUNCTIONS
6795 static struct function **find_function_slot(const char *name)
6797 struct function **funcpp = &G.top_func;
6799 if (strcmp(name, (*funcpp)->name) == 0) {
6802 funcpp = &(*funcpp)->next;
6807 static const struct function *find_function(const char *name)
6809 const struct function *funcp = *find_function_slot(name);
6811 debug_printf_exec("found function '%s'\n", name);
6815 /* Note: takes ownership on name ptr */
6816 static struct function *new_function(char *name)
6818 struct function **funcpp = find_function_slot(name);
6819 struct function *funcp = *funcpp;
6821 if (funcp != NULL) {
6822 struct command *cmd = funcp->parent_cmd;
6823 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6825 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6827 /* Note: if !funcp->body, do not free body_as_string!
6828 * This is a special case of "-F name body" function:
6829 * body_as_string was not malloced! */
6831 free_pipe_list(funcp->body);
6833 free(funcp->body_as_string);
6837 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6838 cmd->argv[0] = funcp->name;
6839 cmd->group = funcp->body;
6841 cmd->group_as_string = funcp->body_as_string;
6845 debug_printf_exec("remembering new function '%s'\n", name);
6846 funcp = *funcpp = xzalloc(sizeof(*funcp));
6847 /*funcp->next = NULL;*/
6854 # if ENABLE_HUSH_UNSET
6855 static void unset_func(const char *name)
6857 struct function **funcpp = find_function_slot(name);
6858 struct function *funcp = *funcpp;
6860 if (funcp != NULL) {
6861 debug_printf_exec("freeing function '%s'\n", funcp->name);
6862 *funcpp = funcp->next;
6863 /* funcp is unlinked now, deleting it.
6864 * Note: if !funcp->body, the function was created by
6865 * "-F name body", do not free ->body_as_string
6866 * and ->name as they were not malloced. */
6868 free_pipe_list(funcp->body);
6871 free(funcp->body_as_string);
6880 #define exec_function(to_free, funcp, argv) \
6881 exec_function(funcp, argv)
6883 static void exec_function(char ***to_free,
6884 const struct function *funcp,
6885 char **argv) NORETURN;
6886 static void exec_function(char ***to_free,
6887 const struct function *funcp,
6893 argv[0] = G.global_argv[0];
6894 G.global_argv = argv;
6895 G.global_argc = n = 1 + string_array_len(argv + 1);
6896 /* On MMU, funcp->body is always non-NULL */
6897 n = run_list(funcp->body);
6901 re_execute_shell(to_free,
6902 funcp->body_as_string,
6909 static int run_function(const struct function *funcp, char **argv)
6915 save_and_replace_G_args(&sv, argv);
6917 /* "we are in function, ok to use return" */
6918 sv_flg = G_flag_return_in_progress;
6919 G_flag_return_in_progress = -1;
6920 # if ENABLE_HUSH_LOCAL
6921 G.func_nest_level++;
6924 /* On MMU, funcp->body is always non-NULL */
6927 /* Function defined by -F */
6928 parse_and_run_string(funcp->body_as_string);
6929 rc = G.last_exitcode;
6933 rc = run_list(funcp->body);
6936 # if ENABLE_HUSH_LOCAL
6938 struct variable *var;
6939 struct variable **var_pp;
6941 var_pp = &G.top_var;
6942 while ((var = *var_pp) != NULL) {
6943 if (var->func_nest_level < G.func_nest_level) {
6944 var_pp = &var->next;
6948 if (var->flg_export)
6949 bb_unsetenv(var->varstr);
6950 /* Remove from global list */
6951 *var_pp = var->next;
6957 G.func_nest_level--;
6960 G_flag_return_in_progress = sv_flg;
6962 restore_G_args(&sv, argv);
6966 #endif /* ENABLE_HUSH_FUNCTIONS */
6970 #define exec_builtin(to_free, x, argv) \
6971 exec_builtin(x, argv)
6973 #define exec_builtin(to_free, x, argv) \
6974 exec_builtin(to_free, argv)
6976 static void exec_builtin(char ***to_free,
6977 const struct built_in_command *x,
6978 char **argv) NORETURN;
6979 static void exec_builtin(char ***to_free,
6980 const struct built_in_command *x,
6986 rcode = x->b_function(argv);
6991 /* On NOMMU, we must never block!
6992 * Example: { sleep 99 | read line; } & echo Ok
6994 re_execute_shell(to_free,
7003 static void execvp_or_die(char **argv) NORETURN;
7004 static void execvp_or_die(char **argv)
7007 debug_printf_exec("execing '%s'\n", argv[0]);
7008 /* Don't propagate SIG_IGN to the child */
7009 if (SPECIAL_JOBSTOP_SIGS != 0)
7010 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7011 execvp(argv[0], argv);
7013 if (errno == EACCES) e = 126;
7014 if (errno == ENOENT) e = 127;
7015 bb_perror_msg("can't execute '%s'", argv[0]);
7019 #if ENABLE_HUSH_MODE_X
7020 static void dump_cmd_in_x_mode(char **argv)
7022 if (G_x_mode && argv) {
7023 /* We want to output the line in one write op */
7031 len += strlen(argv[n++]) + 1;
7037 p += sprintf(p, " %s", argv[n++]);
7045 # define dump_cmd_in_x_mode(argv) ((void)0)
7049 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7050 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7051 #define pseudo_exec(nommu_save, command, argv_expanded) \
7052 pseudo_exec(command, argv_expanded)
7055 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7057 * Don't exit() here. If you don't exec, use _exit instead.
7058 * The at_exit handlers apparently confuse the calling process,
7059 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7061 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7062 char **argv, int assignment_cnt,
7063 char **argv_expanded) NORETURN;
7064 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7065 char **argv, int assignment_cnt,
7066 char **argv_expanded)
7070 new_env = expand_assignments(argv, assignment_cnt);
7071 dump_cmd_in_x_mode(new_env);
7073 if (!argv[assignment_cnt]) {
7074 /* Case when we are here: ... | var=val | ...
7075 * (note that we do not exit early, i.e., do not optimize out
7076 * expand_assignments(): think about ... | var=`sleep 1` | ...
7078 free_strings(new_env);
7079 _exit(EXIT_SUCCESS);
7083 set_vars_and_save_old(new_env);
7084 free(new_env); /* optional */
7085 /* we can also destroy set_vars_and_save_old's return value,
7088 nommu_save->new_env = new_env;
7089 nommu_save->old_vars = set_vars_and_save_old(new_env);
7092 if (argv_expanded) {
7093 argv = argv_expanded;
7095 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7097 nommu_save->argv = argv;
7100 dump_cmd_in_x_mode(argv);
7102 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7103 if (strchr(argv[0], '/') != NULL)
7107 /* Check if the command matches any of the builtins.
7108 * Depending on context, this might be redundant. But it's
7109 * easier to waste a few CPU cycles than it is to figure out
7110 * if this is one of those cases.
7113 /* On NOMMU, it is more expensive to re-execute shell
7114 * just in order to run echo or test builtin.
7115 * It's better to skip it here and run corresponding
7116 * non-builtin later. */
7117 const struct built_in_command *x;
7118 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7120 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7123 #if ENABLE_HUSH_FUNCTIONS
7124 /* Check if the command matches any functions */
7126 const struct function *funcp = find_function(argv[0]);
7128 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7133 #if ENABLE_FEATURE_SH_STANDALONE
7134 /* Check if the command matches any busybox applets */
7136 int a = find_applet_by_name(argv[0]);
7138 # if BB_MMU /* see above why on NOMMU it is not allowed */
7139 if (APPLET_IS_NOEXEC(a)) {
7140 /* Do not leak open fds from opened script files etc */
7141 close_all_FILE_list();
7142 debug_printf_exec("running applet '%s'\n", argv[0]);
7143 run_applet_no_and_exit(a, argv[0], argv);
7146 /* Re-exec ourselves */
7147 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7148 /* Don't propagate SIG_IGN to the child */
7149 if (SPECIAL_JOBSTOP_SIGS != 0)
7150 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7151 execv(bb_busybox_exec_path, argv);
7152 /* If they called chroot or otherwise made the binary no longer
7153 * executable, fall through */
7158 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7161 execvp_or_die(argv);
7164 /* Called after [v]fork() in run_pipe
7166 static void pseudo_exec(nommu_save_t *nommu_save,
7167 struct command *command,
7168 char **argv_expanded) NORETURN;
7169 static void pseudo_exec(nommu_save_t *nommu_save,
7170 struct command *command,
7171 char **argv_expanded)
7173 if (command->argv) {
7174 pseudo_exec_argv(nommu_save, command->argv,
7175 command->assignment_cnt, argv_expanded);
7178 if (command->group) {
7179 /* Cases when we are here:
7182 * ... | ( list ) | ...
7183 * ... | { list } | ...
7187 debug_printf_exec("pseudo_exec: run_list\n");
7188 reset_traps_to_defaults();
7189 rcode = run_list(command->group);
7190 /* OK to leak memory by not calling free_pipe_list,
7191 * since this process is about to exit */
7194 re_execute_shell(&nommu_save->argv_from_re_execing,
7195 command->group_as_string,
7202 /* Case when we are here: ... | >file */
7203 debug_printf_exec("pseudo_exec'ed null command\n");
7204 _exit(EXIT_SUCCESS);
7208 static const char *get_cmdtext(struct pipe *pi)
7214 /* This is subtle. ->cmdtext is created only on first backgrounding.
7215 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7216 * On subsequent bg argv is trashed, but we won't use it */
7220 argv = pi->cmds[0].argv;
7222 pi->cmdtext = xzalloc(1);
7227 len += strlen(*argv) + 1;
7231 argv = pi->cmds[0].argv;
7233 p = stpcpy(p, *argv);
7240 static void insert_job_into_table(struct pipe *pi)
7242 struct pipe *job, **jobp;
7245 /* Find the end of the list, and find next job ID to use */
7248 while ((job = *jobp) != NULL) {
7255 /* Create a new job struct at the end */
7256 job = *jobp = xmemdup(pi, sizeof(*pi));
7258 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7259 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7260 for (i = 0; i < pi->num_cmds; i++) {
7261 job->cmds[i].pid = pi->cmds[i].pid;
7262 /* all other fields are not used and stay zero */
7264 job->cmdtext = xstrdup(get_cmdtext(pi));
7266 if (G_interactive_fd)
7267 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7268 G.last_jobid = job->jobid;
7271 static void remove_job_from_table(struct pipe *pi)
7273 struct pipe *prev_pipe;
7275 if (pi == G.job_list) {
7276 G.job_list = pi->next;
7278 prev_pipe = G.job_list;
7279 while (prev_pipe->next != pi)
7280 prev_pipe = prev_pipe->next;
7281 prev_pipe->next = pi->next;
7284 G.last_jobid = G.job_list->jobid;
7289 static void delete_finished_job(struct pipe *pi)
7291 remove_job_from_table(pi);
7296 static int job_exited_or_stopped(struct pipe *pi)
7300 if (pi->alive_cmds != pi->stopped_cmds)
7303 /* All processes in fg pipe have exited or stopped */
7307 rcode = pi->cmds[i].cmd_exitcode;
7308 /* usually last process gives overall exitstatus,
7309 * but with "set -o pipefail", last *failed* process does */
7310 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7313 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7317 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7324 dead = WIFEXITED(status) || WIFSIGNALED(status);
7327 if (WIFSTOPPED(status))
7328 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7329 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7330 if (WIFSIGNALED(status))
7331 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7332 childpid, WTERMSIG(status), WEXITSTATUS(status));
7333 if (WIFEXITED(status))
7334 debug_printf_jobs("pid %d exited, exitcode %d\n",
7335 childpid, WEXITSTATUS(status));
7337 /* Were we asked to wait for a fg pipe? */
7339 i = fg_pipe->num_cmds;
7344 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7345 if (fg_pipe->cmds[i].pid != childpid)
7349 fg_pipe->cmds[i].pid = 0;
7350 fg_pipe->alive_cmds--;
7351 ex = WEXITSTATUS(status);
7352 /* bash prints killer signal's name for *last*
7353 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7354 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7356 if (WIFSIGNALED(status)) {
7357 int sig = WTERMSIG(status);
7358 if (i == fg_pipe->num_cmds-1)
7359 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7360 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7361 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7362 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7363 * Maybe we need to use sig | 128? */
7366 fg_pipe->cmds[i].cmd_exitcode = ex;
7368 fg_pipe->stopped_cmds++;
7370 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7371 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7372 rcode = job_exited_or_stopped(fg_pipe);
7374 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7375 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7376 * and "killall -STOP cat" */
7377 if (G_interactive_fd) {
7379 if (fg_pipe->alive_cmds != 0)
7380 insert_job_into_table(fg_pipe);
7384 if (fg_pipe->alive_cmds == 0)
7387 /* There are still running processes in the fg_pipe */
7390 /* It wasn't in fg_pipe, look for process in bg pipes */
7394 /* We were asked to wait for bg or orphaned children */
7395 /* No need to remember exitcode in this case */
7396 for (pi = G.job_list; pi; pi = pi->next) {
7397 for (i = 0; i < pi->num_cmds; i++) {
7398 if (pi->cmds[i].pid == childpid)
7399 goto found_pi_and_prognum;
7402 /* Happens when shell is used as init process (init=/bin/sh) */
7403 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7404 return -1; /* this wasn't a process from fg_pipe */
7406 found_pi_and_prognum:
7409 int rcode = WEXITSTATUS(status);
7410 if (WIFSIGNALED(status))
7411 rcode = 128 + WTERMSIG(status);
7412 pi->cmds[i].cmd_exitcode = rcode;
7413 if (G.last_bg_pid == pi->cmds[i].pid)
7414 G.last_bg_pid_exitcode = rcode;
7415 pi->cmds[i].pid = 0;
7417 if (!pi->alive_cmds) {
7418 if (G_interactive_fd)
7419 printf(JOB_STATUS_FORMAT, pi->jobid,
7420 "Done", pi->cmdtext);
7421 delete_finished_job(pi);
7422 //bash deletes finished jobs from job table only in interactive mode, after "jobs" cmd,
7423 //or if pid of a new process matches one of the old ones
7424 //(see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7425 //Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7432 return -1; /* this wasn't a process from fg_pipe */
7435 /* Check to see if any processes have exited -- if they have,
7436 * figure out why and see if a job has completed.
7438 * If non-NULL fg_pipe: wait for its completion or stop.
7439 * Return its exitcode or zero if stopped.
7441 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7442 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7443 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7444 * or 0 if no children changed status.
7446 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7447 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7448 * or 0 if no children changed status.
7450 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7456 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7458 attributes = WUNTRACED;
7459 if (fg_pipe == NULL)
7460 attributes |= WNOHANG;
7463 #if ENABLE_HUSH_FAST
7464 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7465 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7466 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7467 /* There was neither fork nor SIGCHLD since last waitpid */
7468 /* Avoid doing waitpid syscall if possible */
7469 if (!G.we_have_children) {
7473 if (fg_pipe == NULL) { /* is WNOHANG set? */
7474 /* We have children, but they did not exit
7475 * or stop yet (we saw no SIGCHLD) */
7478 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7482 /* Do we do this right?
7483 * bash-3.00# sleep 20 | false
7485 * [3]+ Stopped sleep 20 | false
7486 * bash-3.00# echo $?
7487 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7488 * [hush 1.14.0: yes we do it right]
7492 #if ENABLE_HUSH_FAST
7494 i = G.count_SIGCHLD;
7496 childpid = waitpid(-1, &status, attributes);
7497 if (childpid <= 0) {
7498 if (childpid && errno != ECHILD)
7499 bb_perror_msg("waitpid");
7500 #if ENABLE_HUSH_FAST
7501 else { /* Until next SIGCHLD, waitpid's are useless */
7502 G.we_have_children = (childpid == 0);
7503 G.handled_SIGCHLD = i;
7504 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7507 /* ECHILD (no children), or 0 (no change in children status) */
7511 rcode = process_wait_result(fg_pipe, childpid, status);
7513 /* fg_pipe exited or stopped */
7516 if (childpid == waitfor_pid) {
7517 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7518 rcode = WEXITSTATUS(status);
7519 if (WIFSIGNALED(status))
7520 rcode = 128 + WTERMSIG(status);
7521 if (WIFSTOPPED(status))
7522 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7523 rcode = 128 + WSTOPSIG(status);
7525 break; /* "wait PID" called us, give it exitcode+1 */
7527 /* This wasn't one of our processes, or */
7528 /* fg_pipe still has running processes, do waitpid again */
7529 } /* while (waitpid succeeds)... */
7535 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7538 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7539 if (G_saved_tty_pgrp) {
7540 /* Job finished, move the shell to the foreground */
7541 p = getpgrp(); /* our process group id */
7542 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7543 tcsetpgrp(G_interactive_fd, p);
7549 /* Start all the jobs, but don't wait for anything to finish.
7552 * Return code is normally -1, when the caller has to wait for children
7553 * to finish to determine the exit status of the pipe. If the pipe
7554 * is a simple builtin command, however, the action is done by the
7555 * time run_pipe returns, and the exit code is provided as the
7558 * Returns -1 only if started some children. IOW: we have to
7559 * mask out retvals of builtins etc with 0xff!
7561 * The only case when we do not need to [v]fork is when the pipe
7562 * is single, non-backgrounded, non-subshell command. Examples:
7563 * cmd ; ... { list } ; ...
7564 * cmd && ... { list } && ...
7565 * cmd || ... { list } || ...
7566 * If it is, then we can run cmd as a builtin, NOFORK,
7567 * or (if SH_STANDALONE) an applet, and we can run the { list }
7568 * with run_list. If it isn't one of these, we fork and exec cmd.
7570 * Cases when we must fork:
7571 * non-single: cmd | cmd
7572 * backgrounded: cmd & { list } &
7573 * subshell: ( list ) [&]
7575 #if !ENABLE_HUSH_MODE_X
7576 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7577 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7579 static int redirect_and_varexp_helper(char ***new_env_p,
7580 struct variable **old_vars_p,
7581 struct command *command,
7582 struct squirrel **sqp,
7583 char **argv_expanded)
7585 /* setup_redirects acts on file descriptors, not FILEs.
7586 * This is perfect for work that comes after exec().
7587 * Is it really safe for inline use? Experimentally,
7588 * things seem to work. */
7589 int rcode = setup_redirects(command, sqp);
7591 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7592 *new_env_p = new_env;
7593 dump_cmd_in_x_mode(new_env);
7594 dump_cmd_in_x_mode(argv_expanded);
7596 *old_vars_p = set_vars_and_save_old(new_env);
7600 static NOINLINE int run_pipe(struct pipe *pi)
7602 static const char *const null_ptr = NULL;
7606 struct command *command;
7607 char **argv_expanded;
7609 struct squirrel *squirrel = NULL;
7612 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7615 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7616 * Result should be 3 lines: q w e, qwe, q w e
7618 G.ifs = get_local_var_value("IFS");
7622 IF_HUSH_JOB(pi->pgrp = -1;)
7623 pi->stopped_cmds = 0;
7624 command = &pi->cmds[0];
7625 argv_expanded = NULL;
7627 if (pi->num_cmds != 1
7628 || pi->followup == PIPE_BG
7629 || command->cmd_type == CMD_SUBSHELL
7636 debug_printf_exec(": group:%p argv:'%s'\n",
7637 command->group, command->argv ? command->argv[0] : "NONE");
7639 if (command->group) {
7640 #if ENABLE_HUSH_FUNCTIONS
7641 if (command->cmd_type == CMD_FUNCDEF) {
7642 /* "executing" func () { list } */
7643 struct function *funcp;
7645 funcp = new_function(command->argv[0]);
7646 /* funcp->name is already set to argv[0] */
7647 funcp->body = command->group;
7649 funcp->body_as_string = command->group_as_string;
7650 command->group_as_string = NULL;
7652 command->group = NULL;
7653 command->argv[0] = NULL;
7654 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7655 funcp->parent_cmd = command;
7656 command->child_func = funcp;
7658 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7660 return EXIT_SUCCESS;
7664 debug_printf("non-subshell group\n");
7665 rcode = 1; /* exitcode if redir failed */
7666 if (setup_redirects(command, &squirrel) == 0) {
7667 debug_printf_exec(": run_list\n");
7668 rcode = run_list(command->group) & 0xff;
7670 restore_redirects(squirrel);
7671 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7673 debug_printf_exec("run_pipe: return %d\n", rcode);
7677 argv = command->argv ? command->argv : (char **) &null_ptr;
7679 const struct built_in_command *x;
7680 #if ENABLE_HUSH_FUNCTIONS
7681 const struct function *funcp;
7685 char **new_env = NULL;
7686 struct variable *old_vars = NULL;
7688 if (argv[command->assignment_cnt] == NULL) {
7689 /* Assignments, but no command */
7690 /* Ensure redirects take effect (that is, create files).
7691 * Try "a=t >file" */
7692 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7693 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7694 /* Set shell variables */
7698 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7699 /* Do we need to flag set_local_var() errors?
7700 * "assignment to readonly var" and "putenv error"
7705 /* Redirect error sets $? to 1. Otherwise,
7706 * if evaluating assignment value set $?, retain it.
7707 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7709 rcode = G.last_exitcode;
7710 /* Exit, _skipping_ variable restoring code: */
7711 goto clean_up_and_ret0;
7713 #else /* Older, bigger, but more correct code */
7715 rcode = setup_redirects(command, &squirrel);
7716 restore_redirects(squirrel);
7717 /* Set shell variables */
7719 bb_putchar_stderr('+');
7721 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7723 fprintf(stderr, " %s", p);
7724 debug_printf_exec("set shell var:'%s'->'%s'\n",
7726 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7727 /* Do we need to flag set_local_var() errors?
7728 * "assignment to readonly var" and "putenv error"
7733 bb_putchar_stderr('\n');
7734 /* Redirect error sets $? to 1. Otherwise,
7735 * if evaluating assignment value set $?, retain it.
7736 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7738 rcode = G.last_exitcode;
7739 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7741 debug_printf_exec("run_pipe: return %d\n", rcode);
7746 /* Expand the rest into (possibly) many strings each */
7748 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7749 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7753 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7756 /* if someone gives us an empty string: `cmd with empty output` */
7757 if (!argv_expanded[0]) {
7758 free(argv_expanded);
7760 return G.last_exitcode;
7763 x = find_builtin(argv_expanded[0]);
7764 #if ENABLE_HUSH_FUNCTIONS
7767 funcp = find_function(argv_expanded[0]);
7771 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7772 debug_printf("exec with redirects only\n");
7773 rcode = setup_redirects(command, NULL);
7774 /* rcode=1 can be if redir file can't be opened */
7775 goto clean_up_and_ret1;
7778 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7781 debug_printf_exec(": builtin '%s' '%s'...\n",
7782 x->b_cmd, argv_expanded[1]);
7784 rcode = x->b_function(argv_expanded) & 0xff;
7787 #if ENABLE_HUSH_FUNCTIONS
7789 # if ENABLE_HUSH_LOCAL
7790 struct variable **sv;
7791 sv = G.shadowed_vars_pp;
7792 G.shadowed_vars_pp = &old_vars;
7794 debug_printf_exec(": function '%s' '%s'...\n",
7795 funcp->name, argv_expanded[1]);
7796 rcode = run_function(funcp, argv_expanded) & 0xff;
7797 # if ENABLE_HUSH_LOCAL
7798 G.shadowed_vars_pp = sv;
7804 unset_vars(new_env);
7806 /* clean_up_and_ret0: */
7807 restore_redirects(squirrel);
7809 free(argv_expanded);
7810 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7812 debug_printf_exec("run_pipe return %d\n", rcode);
7816 if (ENABLE_FEATURE_SH_NOFORK) {
7817 int n = find_applet_by_name(argv_expanded[0]);
7818 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7819 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7821 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7822 argv_expanded[0], argv_expanded[1]);
7823 rcode = run_nofork_applet(n, argv_expanded);
7825 goto clean_up_and_ret;
7828 /* It is neither builtin nor applet. We must fork. */
7832 /* NB: argv_expanded may already be created, and that
7833 * might include `cmd` runs! Do not rerun it! We *must*
7834 * use argv_expanded if it's non-NULL */
7836 /* Going to fork a child per each pipe member */
7841 while (cmd_no < pi->num_cmds) {
7842 struct fd_pair pipefds;
7844 volatile nommu_save_t nommu_save;
7845 nommu_save.new_env = NULL;
7846 nommu_save.old_vars = NULL;
7847 nommu_save.argv = NULL;
7848 nommu_save.argv_from_re_execing = NULL;
7850 command = &pi->cmds[cmd_no];
7852 if (command->argv) {
7853 debug_printf_exec(": pipe member '%s' '%s'...\n",
7854 command->argv[0], command->argv[1]);
7856 debug_printf_exec(": pipe member with no argv\n");
7859 /* pipes are inserted between pairs of commands */
7862 if (cmd_no < pi->num_cmds)
7863 xpiped_pair(pipefds);
7865 command->pid = BB_MMU ? fork() : vfork();
7866 if (!command->pid) { /* child */
7868 disable_restore_tty_pgrp_on_exit();
7869 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7871 /* Every child adds itself to new process group
7872 * with pgid == pid_of_first_child_in_pipe */
7873 if (G.run_list_level == 1 && G_interactive_fd) {
7876 if (pgrp < 0) /* true for 1st process only */
7878 if (setpgid(0, pgrp) == 0
7879 && pi->followup != PIPE_BG
7880 && G_saved_tty_pgrp /* we have ctty */
7882 /* We do it in *every* child, not just first,
7884 tcsetpgrp(G_interactive_fd, pgrp);
7888 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7889 /* 1st cmd in backgrounded pipe
7890 * should have its stdin /dev/null'ed */
7892 if (open(bb_dev_null, O_RDONLY))
7893 xopen("/", O_RDONLY);
7895 xmove_fd(next_infd, 0);
7897 xmove_fd(pipefds.wr, 1);
7900 /* Like bash, explicit redirects override pipes,
7901 * and the pipe fd (fd#1) is available for dup'ing:
7902 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7903 * of cmd1 goes into pipe.
7905 if (setup_redirects(command, NULL)) {
7906 /* Happens when redir file can't be opened:
7907 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7909 * hush: can't open '/qwe/rty': No such file or directory
7911 * (echo BAR is not executed, it hits _exit(1) below)
7916 /* Stores to nommu_save list of env vars putenv'ed
7917 * (NOMMU, on MMU we don't need that) */
7918 /* cast away volatility... */
7919 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7920 /* pseudo_exec() does not return */
7923 /* parent or error */
7924 #if ENABLE_HUSH_FAST
7926 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7928 enable_restore_tty_pgrp_on_exit();
7930 /* Clean up after vforked child */
7931 free(nommu_save.argv);
7932 free(nommu_save.argv_from_re_execing);
7933 unset_vars(nommu_save.new_env);
7934 add_vars(nommu_save.old_vars);
7936 free(argv_expanded);
7937 argv_expanded = NULL;
7938 if (command->pid < 0) { /* [v]fork failed */
7939 /* Clearly indicate, was it fork or vfork */
7940 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7944 /* Second and next children need to know pid of first one */
7946 pi->pgrp = command->pid;
7952 if (cmd_no < pi->num_cmds)
7954 /* Pass read (output) pipe end to next iteration */
7955 next_infd = pipefds.rd;
7958 if (!pi->alive_cmds) {
7960 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7965 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7969 /* NB: called by pseudo_exec, and therefore must not modify any
7970 * global data until exec/_exit (we can be a child after vfork!) */
7971 static int run_list(struct pipe *pi)
7973 #if ENABLE_HUSH_CASE
7974 char *case_word = NULL;
7976 #if ENABLE_HUSH_LOOPS
7977 struct pipe *loop_top = NULL;
7978 char **for_lcur = NULL;
7979 char **for_list = NULL;
7981 smallint last_followup;
7983 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7984 smalluint cond_code = 0;
7986 enum { cond_code = 0 };
7989 smallint rword; /* RES_foo */
7990 smallint last_rword; /* ditto */
7993 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7996 #if ENABLE_HUSH_LOOPS
7997 /* Check syntax for "for" */
8000 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8001 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8003 /* current word is FOR or IN (BOLD in comments below) */
8004 if (cpipe->next == NULL) {
8005 syntax_error("malformed for");
8007 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8010 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8011 if (cpipe->next->res_word == RES_DO)
8013 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8014 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8015 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8017 syntax_error("malformed for");
8019 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8026 /* Past this point, all code paths should jump to ret: label
8027 * in order to return, no direct "return" statements please.
8028 * This helps to ensure that no memory is leaked. */
8036 last_rword = RES_XXXX;
8038 last_followup = PIPE_SEQ;
8039 rcode = G.last_exitcode;
8041 /* Go through list of pipes, (maybe) executing them. */
8042 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8044 int sv_errexit_depth;
8048 if (G_flag_return_in_progress == 1)
8051 IF_HAS_KEYWORDS(rword = pi->res_word;)
8052 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8053 rword, cond_code, last_rword);
8055 sv_errexit_depth = G.errexit_depth;
8056 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8057 pi->followup != PIPE_SEQ
8061 #if ENABLE_HUSH_LOOPS
8062 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8063 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8065 /* start of a loop: remember where loop starts */
8070 /* Still in the same "if...", "then..." or "do..." branch? */
8071 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8072 if ((rcode == 0 && last_followup == PIPE_OR)
8073 || (rcode != 0 && last_followup == PIPE_AND)
8075 /* It is "<true> || CMD" or "<false> && CMD"
8076 * and we should not execute CMD */
8077 debug_printf_exec("skipped cmd because of || or &&\n");
8078 last_followup = pi->followup;
8079 goto dont_check_jobs_but_continue;
8082 last_followup = pi->followup;
8083 IF_HAS_KEYWORDS(last_rword = rword;)
8086 if (rword == RES_THEN) {
8087 /* if false; then ... fi has exitcode 0! */
8088 G.last_exitcode = rcode = EXIT_SUCCESS;
8089 /* "if <false> THEN cmd": skip cmd */
8093 if (rword == RES_ELSE || rword == RES_ELIF) {
8094 /* "if <true> then ... ELSE/ELIF cmd":
8095 * skip cmd and all following ones */
8100 #if ENABLE_HUSH_LOOPS
8101 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8103 /* first loop through for */
8105 static const char encoded_dollar_at[] ALIGN1 = {
8106 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8107 }; /* encoded representation of "$@" */
8108 static const char *const encoded_dollar_at_argv[] = {
8109 encoded_dollar_at, NULL
8110 }; /* argv list with one element: "$@" */
8113 vals = (char**)encoded_dollar_at_argv;
8114 if (pi->next->res_word == RES_IN) {
8115 /* if no variable values after "in" we skip "for" */
8116 if (!pi->next->cmds[0].argv) {
8117 G.last_exitcode = rcode = EXIT_SUCCESS;
8118 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8121 vals = pi->next->cmds[0].argv;
8122 } /* else: "for var; do..." -> assume "$@" list */
8123 /* create list of variable values */
8124 debug_print_strings("for_list made from", vals);
8125 for_list = expand_strvec_to_strvec(vals);
8126 for_lcur = for_list;
8127 debug_print_strings("for_list", for_list);
8130 /* "for" loop is over, clean up */
8136 /* Insert next value from for_lcur */
8137 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8138 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8141 if (rword == RES_IN) {
8142 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8144 if (rword == RES_DONE) {
8145 continue; /* "done" has no cmds too */
8148 #if ENABLE_HUSH_CASE
8149 if (rword == RES_CASE) {
8150 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8151 case_word = expand_strvec_to_string(pi->cmds->argv);
8152 unbackslash(case_word);
8155 if (rword == RES_MATCH) {
8158 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8159 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8161 /* all prev words didn't match, does this one match? */
8162 argv = pi->cmds->argv;
8164 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8165 /* TODO: which FNM_xxx flags to use? */
8166 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8167 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8169 if (cond_code == 0) { /* match! we will execute this branch */
8171 case_word = NULL; /* make future "word)" stop */
8178 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8179 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8181 continue; /* not matched yet, skip this pipe */
8183 if (rword == RES_ESAC) {
8184 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8186 /* "case" did not match anything: still set $? (to 0) */
8187 G.last_exitcode = rcode = EXIT_SUCCESS;
8191 /* Just pressing <enter> in shell should check for jobs.
8192 * OTOH, in non-interactive shell this is useless
8193 * and only leads to extra job checks */
8194 if (pi->num_cmds == 0) {
8195 if (G_interactive_fd)
8196 goto check_jobs_and_continue;
8200 /* After analyzing all keywords and conditions, we decided
8201 * to execute this pipe. NB: have to do checkjobs(NULL)
8202 * after run_pipe to collect any background children,
8203 * even if list execution is to be stopped. */
8204 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8205 #if ENABLE_HUSH_LOOPS
8206 G.flag_break_continue = 0;
8208 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8210 /* We ran a builtin, function, or group.
8211 * rcode is already known
8212 * and we don't need to wait for anything. */
8213 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8214 G.last_exitcode = rcode;
8215 check_and_run_traps();
8216 #if ENABLE_HUSH_LOOPS
8217 /* Was it "break" or "continue"? */
8218 if (G.flag_break_continue) {
8219 smallint fbc = G.flag_break_continue;
8220 /* We might fall into outer *loop*,
8221 * don't want to break it too */
8223 G.depth_break_continue--;
8224 if (G.depth_break_continue == 0)
8225 G.flag_break_continue = 0;
8226 /* else: e.g. "continue 2" should *break* once, *then* continue */
8227 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8228 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8229 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8232 /* "continue": simulate end of loop */
8237 if (G_flag_return_in_progress == 1) {
8238 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8241 } else if (pi->followup == PIPE_BG) {
8242 /* What does bash do with attempts to background builtins? */
8243 /* even bash 3.2 doesn't do that well with nested bg:
8244 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8245 * I'm NOT treating inner &'s as jobs */
8247 if (G.run_list_level == 1)
8248 insert_job_into_table(pi);
8250 /* Last command's pid goes to $! */
8251 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8252 G.last_bg_pid_exitcode = 0;
8253 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8254 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8255 rcode = EXIT_SUCCESS;
8259 if (G.run_list_level == 1 && G_interactive_fd) {
8260 /* Waits for completion, then fg's main shell */
8261 rcode = checkjobs_and_fg_shell(pi);
8262 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8266 /* This one just waits for completion */
8267 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8268 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8270 G.last_exitcode = rcode;
8271 check_and_run_traps();
8274 /* Handle "set -e" */
8275 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8276 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8277 if (G.errexit_depth == 0)
8280 G.errexit_depth = sv_errexit_depth;
8282 /* Analyze how result affects subsequent commands */
8284 if (rword == RES_IF || rword == RES_ELIF)
8287 check_jobs_and_continue:
8288 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8289 dont_check_jobs_but_continue: ;
8290 #if ENABLE_HUSH_LOOPS
8291 /* Beware of "while false; true; do ..."! */
8293 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8294 /* check for RES_DONE is needed for "while ...; do \n done" case */
8296 if (rword == RES_WHILE) {
8298 /* "while false; do...done" - exitcode 0 */
8299 G.last_exitcode = rcode = EXIT_SUCCESS;
8300 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8304 if (rword == RES_UNTIL) {
8306 debug_printf_exec(": until expr is true: breaking\n");
8317 #if ENABLE_HUSH_LOOPS
8322 #if ENABLE_HUSH_CASE
8326 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8330 /* Select which version we will use */
8331 static int run_and_free_list(struct pipe *pi)
8334 debug_printf_exec("run_and_free_list entered\n");
8335 if (!G.o_opt[OPT_O_NOEXEC]) {
8336 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8337 rcode = run_list(pi);
8339 /* free_pipe_list has the side effect of clearing memory.
8340 * In the long run that function can be merged with run_list,
8341 * but doing that now would hobble the debugging effort. */
8343 debug_printf_exec("run_and_free_list return %d\n", rcode);
8348 static void install_sighandlers(unsigned mask)
8350 sighandler_t old_handler;
8352 while ((mask >>= 1) != 0) {
8356 old_handler = install_sighandler(sig, pick_sighandler(sig));
8357 /* POSIX allows shell to re-enable SIGCHLD
8358 * even if it was SIG_IGN on entry.
8359 * Therefore we skip IGN check for it:
8363 if (old_handler == SIG_IGN) {
8364 /* oops... restore back to IGN, and record this fact */
8365 install_sighandler(sig, old_handler);
8366 #if ENABLE_HUSH_TRAP
8368 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8370 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8376 /* Called a few times only (or even once if "sh -c") */
8377 static void install_special_sighandlers(void)
8381 /* Which signals are shell-special? */
8382 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8383 if (G_interactive_fd) {
8384 mask |= SPECIAL_INTERACTIVE_SIGS;
8385 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8386 mask |= SPECIAL_JOBSTOP_SIGS;
8388 /* Careful, do not re-install handlers we already installed */
8389 if (G.special_sig_mask != mask) {
8390 unsigned diff = mask & ~G.special_sig_mask;
8391 G.special_sig_mask = mask;
8392 install_sighandlers(diff);
8398 /* Set handlers to restore tty pgrp and exit */
8399 static void install_fatal_sighandlers(void)
8403 /* We will restore tty pgrp on these signals */
8405 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8406 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8407 + (1 << SIGBUS ) * HUSH_DEBUG
8408 + (1 << SIGSEGV) * HUSH_DEBUG
8409 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8411 /* bash 3.2 seems to handle these just like 'fatal' ones */
8414 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8415 * if we aren't interactive... but in this case
8416 * we never want to restore pgrp on exit, and this fn is not called
8418 /*+ (1 << SIGHUP )*/
8419 /*+ (1 << SIGTERM)*/
8420 /*+ (1 << SIGINT )*/
8422 G_fatal_sig_mask = mask;
8424 install_sighandlers(mask);
8428 static int set_mode(int state, char mode, const char *o_opt)
8433 G.o_opt[OPT_O_NOEXEC] = state;
8436 IF_HUSH_MODE_X(G_x_mode = state;)
8440 /* "set -+o" without parameter.
8441 * in bash, set -o produces this output:
8445 * We always use the second form.
8447 const char *p = o_opt_strings;
8450 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8456 idx = index_in_strings(o_opt_strings, o_opt);
8458 G.o_opt[idx] = state;
8462 G.o_opt[OPT_O_ERREXIT] = state;
8465 return EXIT_FAILURE;
8467 return EXIT_SUCCESS;
8470 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8471 int hush_main(int argc, char **argv)
8474 OPT_login = (1 << 0),
8478 unsigned builtin_argc;
8480 struct variable *cur_var;
8481 struct variable *shell_ver;
8484 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8485 G.last_exitcode = EXIT_SUCCESS;
8487 #if ENABLE_HUSH_FAST
8488 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8491 G.argv0_for_re_execing = argv[0];
8493 /* Deal with HUSH_VERSION */
8494 shell_ver = xzalloc(sizeof(*shell_ver));
8495 shell_ver->flg_export = 1;
8496 shell_ver->flg_read_only = 1;
8497 /* Code which handles ${var<op>...} needs writable values for all variables,
8498 * therefore we xstrdup: */
8499 shell_ver->varstr = xstrdup(hush_version_str);
8500 /* Create shell local variables from the values
8501 * currently living in the environment */
8502 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8503 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8504 G.top_var = shell_ver;
8505 cur_var = G.top_var;
8508 char *value = strchr(*e, '=');
8509 if (value) { /* paranoia */
8510 cur_var->next = xzalloc(sizeof(*cur_var));
8511 cur_var = cur_var->next;
8512 cur_var->varstr = *e;
8513 cur_var->max_len = strlen(*e);
8514 cur_var->flg_export = 1;
8518 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8519 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8520 putenv(shell_ver->varstr);
8523 set_pwd_var(/*exp:*/ 1);
8525 #if BASH_HOSTNAME_VAR
8526 /* Set (but not export) HOSTNAME unless already set */
8527 if (!get_local_var_value("HOSTNAME")) {
8530 set_local_var_from_halves("HOSTNAME", uts.nodename);
8532 /* bash also exports SHLVL and _,
8533 * and sets (but doesn't export) the following variables:
8535 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8536 * BASH_VERSION='3.2.0(1)-release'
8538 * MACHTYPE=i386-pc-linux-gnu
8540 * PPID=<NNNNN> - we also do it elsewhere
8551 * PIPESTATUS=([0]="0")
8552 * HISTFILE=/<xxx>/.bash_history
8556 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8558 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8569 #if ENABLE_FEATURE_EDITING
8570 G.line_input_state = new_line_input_t(FOR_SHELL);
8573 /* Initialize some more globals to non-zero values */
8574 cmdedit_update_prompt();
8576 die_func = restore_ttypgrp_and__exit;
8578 /* Shell is non-interactive at first. We need to call
8579 * install_special_sighandlers() if we are going to execute "sh <script>",
8580 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8581 * If we later decide that we are interactive, we run install_special_sighandlers()
8582 * in order to intercept (more) signals.
8586 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8587 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8590 opt = getopt(argc, argv, "+c:exinsl"
8593 # if ENABLE_HUSH_FUNCTIONS
8603 * sh ... -c 'script'
8604 * sh ... -c 'script' ARG0 [ARG1...]
8605 * On NOMMU, if builtin_argc != 0,
8606 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8607 * "" needs to be replaced with NULL
8608 * and BARGV vector fed to builtin function.
8609 * Note: the form without ARG0 never happens:
8610 * sh ... -c 'builtin' BARGV... ""
8613 G.root_pid = getpid();
8614 G.root_ppid = getppid();
8616 G.global_argv = argv + optind;
8617 G.global_argc = argc - optind;
8619 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8620 const struct built_in_command *x;
8622 install_special_sighandlers();
8623 x = find_builtin(optarg);
8624 if (x) { /* paranoia */
8625 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8626 G.global_argv += builtin_argc;
8627 G.global_argv[-1] = NULL; /* replace "" */
8629 G.last_exitcode = x->b_function(argv + optind - 1);
8633 if (!G.global_argv[0]) {
8634 /* -c 'script' (no params): prevent empty $0 */
8635 G.global_argv--; /* points to argv[i] of 'script' */
8636 G.global_argv[0] = argv[0];
8638 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8639 install_special_sighandlers();
8640 parse_and_run_string(optarg);
8643 /* Well, we cannot just declare interactiveness,
8644 * we have to have some stuff (ctty, etc) */
8645 /* G_interactive_fd++; */
8648 /* "-s" means "read from stdin", but this is how we always
8649 * operate, so simply do nothing here. */
8655 case '<': /* "big heredoc" support */
8656 full_write1_str(optarg);
8659 unsigned long long empty_trap_mask;
8661 G.root_pid = bb_strtou(optarg, &optarg, 16);
8663 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8665 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8667 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8669 builtin_argc = bb_strtou(optarg, &optarg, 16);
8671 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8672 if (empty_trap_mask != 0) {
8673 IF_HUSH_TRAP(int sig;)
8674 install_special_sighandlers();
8675 # if ENABLE_HUSH_TRAP
8676 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8677 for (sig = 1; sig < NSIG; sig++) {
8678 if (empty_trap_mask & (1LL << sig)) {
8679 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8680 install_sighandler(sig, SIG_IGN);
8685 # if ENABLE_HUSH_LOOPS
8687 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8693 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8695 # if ENABLE_HUSH_FUNCTIONS
8697 struct function *funcp = new_function(optarg);
8698 /* funcp->name is already set to optarg */
8699 /* funcp->body is set to NULL. It's a special case. */
8700 funcp->body_as_string = argv[optind];
8709 if (set_mode(1, opt, NULL) == 0) /* no error */
8713 fprintf(stderr, "Usage: sh [FILE]...\n"
8714 " or: sh -c command [args]...\n\n");
8720 } /* option parsing loop */
8722 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8723 G.global_argc = argc - (optind - 1);
8724 G.global_argv = argv + (optind - 1);
8725 G.global_argv[0] = argv[0];
8728 G.root_pid = getpid();
8729 G.root_ppid = getppid();
8732 /* If we are login shell... */
8733 if (flags & OPT_login) {
8735 debug_printf("sourcing /etc/profile\n");
8736 input = fopen_for_read("/etc/profile");
8737 if (input != NULL) {
8738 remember_FILE(input);
8739 install_special_sighandlers();
8740 parse_and_run_file(input);
8741 fclose_and_forget(input);
8743 /* bash: after sourcing /etc/profile,
8744 * tries to source (in the given order):
8745 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8746 * stopping on first found. --noprofile turns this off.
8747 * bash also sources ~/.bash_logout on exit.
8748 * If called as sh, skips .bash_XXX files.
8752 if (G.global_argv[1]) {
8755 * "bash <script>" (which is never interactive (unless -i?))
8756 * sources $BASH_ENV here (without scanning $PATH).
8757 * If called as sh, does the same but with $ENV.
8758 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8762 debug_printf("running script '%s'\n", G.global_argv[0]);
8763 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8764 input = xfopen_for_read(G.global_argv[0]);
8765 xfunc_error_retval = 1;
8766 remember_FILE(input);
8767 install_special_sighandlers();
8768 parse_and_run_file(input);
8769 #if ENABLE_FEATURE_CLEAN_UP
8770 fclose_and_forget(input);
8775 /* Up to here, shell was non-interactive. Now it may become one.
8776 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8779 /* A shell is interactive if the '-i' flag was given,
8780 * or if all of the following conditions are met:
8782 * no arguments remaining or the -s flag given
8783 * standard input is a terminal
8784 * standard output is a terminal
8785 * Refer to Posix.2, the description of the 'sh' utility.
8788 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8789 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8790 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8791 if (G_saved_tty_pgrp < 0)
8792 G_saved_tty_pgrp = 0;
8794 /* try to dup stdin to high fd#, >= 255 */
8795 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8796 if (G_interactive_fd < 0) {
8797 /* try to dup to any fd */
8798 G_interactive_fd = dup(STDIN_FILENO);
8799 if (G_interactive_fd < 0) {
8801 G_interactive_fd = 0;
8802 G_saved_tty_pgrp = 0;
8805 // TODO: track & disallow any attempts of user
8806 // to (inadvertently) close/redirect G_interactive_fd
8808 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8809 if (G_interactive_fd) {
8810 close_on_exec_on(G_interactive_fd);
8812 if (G_saved_tty_pgrp) {
8813 /* If we were run as 'hush &', sleep until we are
8814 * in the foreground (tty pgrp == our pgrp).
8815 * If we get started under a job aware app (like bash),
8816 * make sure we are now in charge so we don't fight over
8817 * who gets the foreground */
8819 pid_t shell_pgrp = getpgrp();
8820 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8821 if (G_saved_tty_pgrp == shell_pgrp)
8823 /* send TTIN to ourself (should stop us) */
8824 kill(- shell_pgrp, SIGTTIN);
8828 /* Install more signal handlers */
8829 install_special_sighandlers();
8831 if (G_saved_tty_pgrp) {
8832 /* Set other signals to restore saved_tty_pgrp */
8833 install_fatal_sighandlers();
8834 /* Put ourselves in our own process group
8835 * (bash, too, does this only if ctty is available) */
8836 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8837 /* Grab control of the terminal */
8838 tcsetpgrp(G_interactive_fd, getpid());
8840 enable_restore_tty_pgrp_on_exit();
8842 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8844 const char *hp = get_local_var_value("HISTFILE");
8846 hp = get_local_var_value("HOME");
8848 hp = concat_path_file(hp, ".hush_history");
8853 G.line_input_state->hist_file = hp;
8854 //set_local_var(xasprintf("HISTFILE=%s", ...));
8856 # if ENABLE_FEATURE_SH_HISTFILESIZE
8857 hp = get_local_var_value("HISTFILESIZE");
8858 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8863 install_special_sighandlers();
8865 #elif ENABLE_HUSH_INTERACTIVE
8866 /* No job control compiled in, only prompt/line editing */
8867 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8868 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8869 if (G_interactive_fd < 0) {
8870 /* try to dup to any fd */
8871 G_interactive_fd = dup(STDIN_FILENO);
8872 if (G_interactive_fd < 0)
8874 G_interactive_fd = 0;
8877 if (G_interactive_fd) {
8878 close_on_exec_on(G_interactive_fd);
8880 install_special_sighandlers();
8882 /* We have interactiveness code disabled */
8883 install_special_sighandlers();
8886 * if interactive but not a login shell, sources ~/.bashrc
8887 * (--norc turns this off, --rcfile <file> overrides)
8890 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8891 /* note: ash and hush share this string */
8892 printf("\n\n%s %s\n"
8893 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8896 "hush - the humble shell"
8900 parse_and_run_file(stdin);
8903 hush_exit(G.last_exitcode);
8910 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8915 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8916 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8918 int argc = string_array_len(argv);
8919 return applet_main_func(argc, argv);
8922 #if ENABLE_HUSH_TEST || BASH_TEST2
8923 static int FAST_FUNC builtin_test(char **argv)
8925 return run_applet_main(argv, test_main);
8928 #if ENABLE_HUSH_ECHO
8929 static int FAST_FUNC builtin_echo(char **argv)
8931 return run_applet_main(argv, echo_main);
8934 #if ENABLE_HUSH_PRINTF
8935 static int FAST_FUNC builtin_printf(char **argv)
8937 return run_applet_main(argv, printf_main);
8941 #if ENABLE_HUSH_HELP
8942 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8944 const struct built_in_command *x;
8947 "Built-in commands:\n"
8948 "------------------\n");
8949 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8951 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8953 return EXIT_SUCCESS;
8957 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8958 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8960 show_history(G.line_input_state);
8961 return EXIT_SUCCESS;
8965 static char **skip_dash_dash(char **argv)
8968 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8973 static int FAST_FUNC builtin_cd(char **argv)
8977 argv = skip_dash_dash(argv);
8979 if (newdir == NULL) {
8980 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8981 * bash says "bash: cd: HOME not set" and does nothing
8984 const char *home = get_local_var_value("HOME");
8985 newdir = home ? home : "/";
8987 if (chdir(newdir)) {
8988 /* Mimic bash message exactly */
8989 bb_perror_msg("cd: %s", newdir);
8990 return EXIT_FAILURE;
8992 /* Read current dir (get_cwd(1) is inside) and set PWD.
8993 * Note: do not enforce exporting. If PWD was unset or unexported,
8994 * set it again, but do not export. bash does the same.
8996 set_pwd_var(/*exp:*/ 0);
8997 return EXIT_SUCCESS;
9000 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9003 return EXIT_SUCCESS;
9006 static int FAST_FUNC builtin_eval(char **argv)
9008 int rcode = EXIT_SUCCESS;
9010 argv = skip_dash_dash(argv);
9012 char *str = expand_strvec_to_string(argv);
9014 * eval "echo Hi; done" ("done" is syntax error):
9015 * "echo Hi" will not execute too.
9017 parse_and_run_string(str);
9019 rcode = G.last_exitcode;
9024 static int FAST_FUNC builtin_exec(char **argv)
9026 argv = skip_dash_dash(argv);
9027 if (argv[0] == NULL)
9028 return EXIT_SUCCESS; /* bash does this */
9030 /* Careful: we can end up here after [v]fork. Do not restore
9031 * tty pgrp then, only top-level shell process does that */
9032 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9033 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9035 /* TODO: if exec fails, bash does NOT exit! We do.
9036 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9037 * and tcsetpgrp, and this is inherently racy.
9039 execvp_or_die(argv);
9042 static int FAST_FUNC builtin_exit(char **argv)
9044 debug_printf_exec("%s()\n", __func__);
9046 /* interactive bash:
9047 * # trap "echo EEE" EXIT
9050 * There are stopped jobs.
9051 * (if there are _stopped_ jobs, running ones don't count)
9054 * EEE (then bash exits)
9056 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9059 /* note: EXIT trap is run by hush_exit */
9060 argv = skip_dash_dash(argv);
9061 if (argv[0] == NULL)
9062 hush_exit(G.last_exitcode);
9063 /* mimic bash: exit 123abc == exit 255 + error msg */
9064 xfunc_error_retval = 255;
9065 /* bash: exit -2 == exit 254, no error msg */
9066 hush_exit(xatoi(argv[0]) & 0xff);
9069 #if ENABLE_HUSH_TYPE
9070 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9071 static int FAST_FUNC builtin_type(char **argv)
9073 int ret = EXIT_SUCCESS;
9079 if (0) {} /* make conditional compile easier below */
9080 /*else if (find_alias(*argv))
9081 type = "an alias";*/
9082 #if ENABLE_HUSH_FUNCTIONS
9083 else if (find_function(*argv))
9084 type = "a function";
9086 else if (find_builtin(*argv))
9087 type = "a shell builtin";
9088 else if ((path = find_in_path(*argv)) != NULL)
9091 bb_error_msg("type: %s: not found", *argv);
9096 printf("%s is %s\n", *argv, type);
9104 #if ENABLE_HUSH_READ
9105 /* Interruptibility of read builtin in bash
9106 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9108 * Empty trap makes read ignore corresponding signal, for any signal.
9111 * - terminates non-interactive shell;
9112 * - interrupts read in interactive shell;
9113 * if it has non-empty trap:
9114 * - executes trap and returns to command prompt in interactive shell;
9115 * - executes trap and returns to read in non-interactive shell;
9117 * - is ignored (does not interrupt) read in interactive shell;
9118 * - terminates non-interactive shell;
9119 * if it has non-empty trap:
9120 * - executes trap and returns to read;
9122 * - terminates shell (regardless of interactivity);
9123 * if it has non-empty trap:
9124 * - executes trap and returns to read;
9125 * SIGCHLD from children:
9126 * - does not interrupt read regardless of interactivity:
9127 * try: sleep 1 & read x; echo $x
9129 static int FAST_FUNC builtin_read(char **argv)
9139 /* "!": do not abort on errors.
9140 * Option string must start with "sr" to match BUILTIN_READ_xxx
9142 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9143 if (read_flags == (uint32_t)-1)
9144 return EXIT_FAILURE;
9146 ifs = get_local_var_value("IFS"); /* can be NULL */
9149 r = shell_builtin_read(set_local_var_from_halves,
9159 if ((uintptr_t)r == 1 && errno == EINTR) {
9160 unsigned sig = check_and_run_traps();
9165 if ((uintptr_t)r > 1) {
9166 bb_error_msg("%s", r);
9167 r = (char*)(uintptr_t)1;
9170 return (uintptr_t)r;
9174 #if ENABLE_HUSH_UMASK
9175 static int FAST_FUNC builtin_umask(char **argv)
9182 argv = skip_dash_dash(argv);
9184 mode_t old_mask = mask;
9186 /* numeric umasks are taken as-is */
9187 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9188 if (!isdigit(argv[0][0]))
9190 mask = bb_parse_mode(argv[0], mask);
9191 if (!isdigit(argv[0][0]))
9193 if ((unsigned)mask > 0777) {
9196 * bash: umask: 'q': invalid symbolic mode operator
9197 * bash: umask: 999: octal number out of range
9199 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9204 printf("%04o\n", (unsigned) mask);
9205 /* fall through and restore mask which we set to 0 */
9209 return !rc; /* rc != 0 - success */
9213 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9214 static void print_escaped(const char *s)
9219 const char *p = strchrnul(s, '\'');
9220 /* print 'xxxx', possibly just '' */
9221 printf("'%.*s'", (int)(p - s), s);
9226 /* s points to '; print "'''...'''" */
9228 do putchar('\''); while (*++s == '\'');
9234 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9235 # if !ENABLE_HUSH_LOCAL
9236 #define helper_export_local(argv, exp, lvl) \
9237 helper_export_local(argv, exp)
9239 static void helper_export_local(char **argv, int exp, int lvl)
9243 char *name_end = strchrnul(name, '=');
9245 /* So far we do not check that name is valid (TODO?) */
9247 if (*name_end == '\0') {
9248 struct variable *var, **vpp;
9250 vpp = get_ptr_to_local_var(name, name_end - name);
9251 var = vpp ? *vpp : NULL;
9253 if (exp == -1) { /* unexporting? */
9254 /* export -n NAME (without =VALUE) */
9256 var->flg_export = 0;
9257 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9259 } /* else: export -n NOT_EXISTING_VAR: no-op */
9262 if (exp == 1) { /* exporting? */
9263 /* export NAME (without =VALUE) */
9265 var->flg_export = 1;
9266 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9267 putenv(var->varstr);
9271 # if ENABLE_HUSH_LOCAL
9272 if (exp == 0 /* local? */
9273 && var && var->func_nest_level == lvl
9275 /* "local x=abc; ...; local x" - ignore second local decl */
9279 /* Exporting non-existing variable.
9280 * bash does not put it in environment,
9281 * but remembers that it is exported,
9282 * and does put it in env when it is set later.
9283 * We just set it to "" and export. */
9284 /* Or, it's "local NAME" (without =VALUE).
9285 * bash sets the value to "". */
9286 name = xasprintf("%s=", name);
9288 /* (Un)exporting/making local NAME=VALUE */
9289 name = xstrdup(name);
9291 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9296 #if ENABLE_HUSH_EXPORT
9297 static int FAST_FUNC builtin_export(char **argv)
9299 unsigned opt_unexport;
9301 #if ENABLE_HUSH_EXPORT_N
9302 /* "!": do not abort on errors */
9303 opt_unexport = getopt32(argv, "!n");
9304 if (opt_unexport == (uint32_t)-1)
9305 return EXIT_FAILURE;
9312 if (argv[0] == NULL) {
9319 /* ash emits: export VAR='VAL'
9320 * bash: declare -x VAR="VAL"
9321 * we follow ash example */
9322 const char *s = *e++;
9323 const char *p = strchr(s, '=');
9325 if (!p) /* wtf? take next variable */
9328 printf("export %.*s", (int)(p - s) + 1, s);
9329 print_escaped(p + 1);
9333 /*fflush_all(); - done after each builtin anyway */
9335 return EXIT_SUCCESS;
9338 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9340 return EXIT_SUCCESS;
9344 #if ENABLE_HUSH_LOCAL
9345 static int FAST_FUNC builtin_local(char **argv)
9347 if (G.func_nest_level == 0) {
9348 bb_error_msg("%s: not in a function", argv[0]);
9349 return EXIT_FAILURE; /* bash compat */
9351 helper_export_local(argv, 0, G.func_nest_level);
9352 return EXIT_SUCCESS;
9356 #if ENABLE_HUSH_UNSET
9357 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9358 static int FAST_FUNC builtin_unset(char **argv)
9363 /* "!": do not abort on errors */
9364 /* "+": stop at 1st non-option */
9365 opts = getopt32(argv, "!+vf");
9366 if (opts == (unsigned)-1)
9367 return EXIT_FAILURE;
9369 bb_error_msg("unset: -v and -f are exclusive");
9370 return EXIT_FAILURE;
9376 if (!(opts & 2)) { /* not -f */
9377 if (unset_local_var(*argv)) {
9378 /* unset <nonexistent_var> doesn't fail.
9379 * Error is when one tries to unset RO var.
9380 * Message was printed by unset_local_var. */
9384 # if ENABLE_HUSH_FUNCTIONS
9396 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9397 * built-in 'set' handler
9399 * set [-abCefhmnuvx] [-o option] [argument...]
9400 * set [+abCefhmnuvx] [+o option] [argument...]
9401 * set -- [argument...]
9404 * Implementations shall support the options in both their hyphen and
9405 * plus-sign forms. These options can also be specified as options to sh.
9407 * Write out all variables and their values: set
9408 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9409 * Turn on the -x and -v options: set -xv
9410 * Unset all positional parameters: set --
9411 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9412 * Set the positional parameters to the expansion of x, even if x expands
9413 * with a leading '-' or '+': set -- $x
9415 * So far, we only support "set -- [argument...]" and some of the short names.
9417 static int FAST_FUNC builtin_set(char **argv)
9420 char **pp, **g_argv;
9421 char *arg = *++argv;
9425 for (e = G.top_var; e; e = e->next)
9427 return EXIT_SUCCESS;
9431 if (strcmp(arg, "--") == 0) {
9435 if (arg[0] != '+' && arg[0] != '-')
9437 for (n = 1; arg[n]; ++n) {
9438 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9440 if (arg[n] == 'o' && argv[1])
9443 } while ((arg = *++argv) != NULL);
9444 /* Now argv[0] is 1st argument */
9447 return EXIT_SUCCESS;
9450 /* NB: G.global_argv[0] ($0) is never freed/changed */
9451 g_argv = G.global_argv;
9452 if (G.global_args_malloced) {
9458 G.global_args_malloced = 1;
9459 pp = xzalloc(sizeof(pp[0]) * 2);
9460 pp[0] = g_argv[0]; /* retain $0 */
9463 /* This realloc's G.global_argv */
9464 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9466 G.global_argc = 1 + string_array_len(pp + 1);
9468 return EXIT_SUCCESS;
9470 /* Nothing known, so abort */
9472 bb_error_msg("set: %s: invalid option", arg);
9473 return EXIT_FAILURE;
9477 static int FAST_FUNC builtin_shift(char **argv)
9480 argv = skip_dash_dash(argv);
9482 n = bb_strtou(argv[0], NULL, 10);
9483 if (errno || n < 0) {
9484 /* shared string with ash.c */
9485 bb_error_msg("Illegal number: %s", argv[0]);
9487 * ash aborts in this case.
9488 * bash prints error message and set $? to 1.
9489 * Interestingly, for "shift 99999" bash does not
9490 * print error message, but does set $? to 1
9491 * (and does no shifting at all).
9495 if (n >= 0 && n < G.global_argc) {
9496 if (G_global_args_malloced) {
9499 free(G.global_argv[m++]);
9502 memmove(&G.global_argv[1], &G.global_argv[n+1],
9503 G.global_argc * sizeof(G.global_argv[0]));
9504 return EXIT_SUCCESS;
9506 return EXIT_FAILURE;
9509 static int FAST_FUNC builtin_source(char **argv)
9511 char *arg_path, *filename;
9514 char *args_need_save;
9515 #if ENABLE_HUSH_FUNCTIONS
9519 argv = skip_dash_dash(argv);
9522 /* bash says: "bash: .: filename argument required" */
9523 return 2; /* bash compat */
9526 if (!strchr(filename, '/')) {
9527 arg_path = find_in_path(filename);
9529 filename = arg_path;
9531 input = remember_FILE(fopen_or_warn(filename, "r"));
9534 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9535 /* POSIX: non-interactive shell should abort here,
9536 * not merely fail. So far no one complained :)
9538 return EXIT_FAILURE;
9541 #if ENABLE_HUSH_FUNCTIONS
9542 sv_flg = G_flag_return_in_progress;
9543 /* "we are inside sourced file, ok to use return" */
9544 G_flag_return_in_progress = -1;
9546 args_need_save = argv[1]; /* used as a boolean variable */
9548 save_and_replace_G_args(&sv, argv);
9550 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9551 G.last_exitcode = 0;
9552 parse_and_run_file(input);
9553 fclose_and_forget(input);
9555 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9556 restore_G_args(&sv, argv);
9557 #if ENABLE_HUSH_FUNCTIONS
9558 G_flag_return_in_progress = sv_flg;
9561 return G.last_exitcode;
9564 #if ENABLE_HUSH_TRAP
9565 static int FAST_FUNC builtin_trap(char **argv)
9571 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9576 /* No args: print all trapped */
9577 for (i = 0; i < NSIG; ++i) {
9580 print_escaped(G_traps[i]);
9581 /* note: bash adds "SIG", but only if invoked
9582 * as "bash". If called as "sh", or if set -o posix,
9583 * then it prints short signal names.
9584 * We are printing short names: */
9585 printf(" %s\n", get_signame(i));
9588 /*fflush_all(); - done after each builtin anyway */
9589 return EXIT_SUCCESS;
9593 /* If first arg is a number: reset all specified signals */
9594 sig = bb_strtou(*argv, NULL, 10);
9600 sighandler_t handler;
9602 sig = get_signum(*argv++);
9603 if (sig < 0 || sig >= NSIG) {
9605 /* Mimic bash message exactly */
9606 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9611 G_traps[sig] = xstrdup(new_cmd);
9613 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9614 get_signame(sig), sig, G_traps[sig]);
9616 /* There is no signal for 0 (EXIT) */
9621 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9623 /* We are removing trap handler */
9624 handler = pick_sighandler(sig);
9625 install_sighandler(sig, handler);
9630 if (!argv[1]) { /* no second arg */
9631 bb_error_msg("trap: invalid arguments");
9632 return EXIT_FAILURE;
9635 /* First arg is "-": reset all specified to default */
9636 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9637 /* Everything else: set arg as signal handler
9638 * (includes "" case, which ignores signal) */
9639 if (argv[0][0] == '-') {
9640 if (argv[0][1] == '\0') { /* "-" */
9641 /* new_cmd remains NULL: "reset these sigs" */
9644 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9647 /* else: "-something", no special meaning */
9652 goto process_sig_list;
9657 static struct pipe *parse_jobspec(const char *str)
9662 if (sscanf(str, "%%%u", &jobnum) != 1) {
9664 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9666 bb_error_msg("bad argument '%s'", str);
9669 /* It is "%%", "%+" or "%" - current job */
9670 jobnum = G.last_jobid;
9672 bb_error_msg("no current job");
9676 for (pi = G.job_list; pi; pi = pi->next) {
9677 if (pi->jobid == jobnum) {
9681 bb_error_msg("%u: no such job", jobnum);
9685 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9688 const char *status_string;
9690 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9691 for (job = G.job_list; job; job = job->next) {
9692 if (job->alive_cmds == job->stopped_cmds)
9693 status_string = "Stopped";
9695 status_string = "Running";
9697 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9699 return EXIT_SUCCESS;
9702 /* built-in 'fg' and 'bg' handler */
9703 static int FAST_FUNC builtin_fg_bg(char **argv)
9708 if (!G_interactive_fd)
9709 return EXIT_FAILURE;
9711 /* If they gave us no args, assume they want the last backgrounded task */
9713 for (pi = G.job_list; pi; pi = pi->next) {
9714 if (pi->jobid == G.last_jobid) {
9718 bb_error_msg("%s: no current job", argv[0]);
9719 return EXIT_FAILURE;
9722 pi = parse_jobspec(argv[1]);
9724 return EXIT_FAILURE;
9726 /* TODO: bash prints a string representation
9727 * of job being foregrounded (like "sleep 1 | cat") */
9728 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9729 /* Put the job into the foreground. */
9730 tcsetpgrp(G_interactive_fd, pi->pgrp);
9733 /* Restart the processes in the job */
9734 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9735 for (i = 0; i < pi->num_cmds; i++) {
9736 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9738 pi->stopped_cmds = 0;
9740 i = kill(- pi->pgrp, SIGCONT);
9742 if (errno == ESRCH) {
9743 delete_finished_job(pi);
9744 return EXIT_SUCCESS;
9746 bb_perror_msg("kill (SIGCONT)");
9749 if (argv[0][0] == 'f') {
9750 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9751 return checkjobs_and_fg_shell(pi);
9753 return EXIT_SUCCESS;
9757 #if ENABLE_HUSH_KILL
9758 static int FAST_FUNC builtin_kill(char **argv)
9762 # if ENABLE_HUSH_JOB
9763 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9771 if (argv[i][0] != '%')
9774 * "kill %N" - job kill
9775 * Converting to pgrp / pid kill
9777 pi = parse_jobspec(argv[i]);
9779 /* Eat bad jobspec */
9783 argv[j - 1] = argv[j];
9790 * In jobs started under job control, we signal
9791 * entire process group by kill -PGRP_ID.
9792 * This happens, f.e., in interactive shell.
9794 * Otherwise, we signal each child via
9795 * kill PID1 PID2 PID3.
9797 * sh -c 'sleep 1|sleep 1 & kill %1'
9798 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9799 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9801 n = G_interactive_fd ? 1 : pi->num_cmds;
9802 dst = alloca(n * sizeof(int)*4);
9804 if (G_interactive_fd)
9805 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9806 else for (j = 0; j < n; j++) {
9807 struct command *cmd = &pi->cmds[j];
9808 /* Skip exited members of the job */
9812 * kill_main has matching code to expect
9813 * leading space. Needed to not confuse
9814 * negative pids with "kill -SIGNAL_NO" syntax
9816 dst += sprintf(dst, " %u", (int)cmd->pid);
9819 } while (argv[++i]);
9823 if (argv[1] || ret == 0) {
9824 ret = run_applet_main(argv, kill_main);
9826 /* else: ret = 1, "kill %bad_jobspec" case */
9831 #if ENABLE_HUSH_WAIT
9832 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9833 #if !ENABLE_HUSH_JOB
9834 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9836 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9843 if (!sigisemptyset(&G.pending_set))
9846 /* waitpid is not interruptible by SA_RESTARTed
9847 * signals which we use. Thus, this ugly dance:
9850 /* Make sure possible SIGCHLD is stored in kernel's
9851 * pending signal mask before we call waitpid.
9852 * Or else we may race with SIGCHLD, lose it,
9853 * and get stuck in sigsuspend...
9855 sigfillset(&oldset); /* block all signals, remember old set */
9856 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9858 if (!sigisemptyset(&G.pending_set)) {
9859 /* Crap! we raced with some signal! */
9863 /*errno = 0; - checkjobs does this */
9864 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9865 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9866 debug_printf_exec("checkjobs:%d\n", ret);
9869 int rcode = job_exited_or_stopped(waitfor_pipe);
9870 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9873 sigprocmask(SIG_SETMASK, &oldset, NULL);
9878 /* if ECHILD, there are no children (ret is -1 or 0) */
9879 /* if ret == 0, no children changed state */
9880 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9881 if (errno == ECHILD || ret) {
9883 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9885 sigprocmask(SIG_SETMASK, &oldset, NULL);
9888 /* Wait for SIGCHLD or any other signal */
9889 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9890 /* Note: sigsuspend invokes signal handler */
9891 sigsuspend(&oldset);
9893 sigprocmask(SIG_SETMASK, &oldset, NULL);
9895 /* So, did we get a signal? */
9896 sig = check_and_run_traps();
9897 if (sig /*&& sig != SIGCHLD - always true */) {
9901 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9906 static int FAST_FUNC builtin_wait(char **argv)
9911 argv = skip_dash_dash(argv);
9912 if (argv[0] == NULL) {
9913 /* Don't care about wait results */
9914 /* Note 1: must wait until there are no more children */
9915 /* Note 2: must be interruptible */
9917 * $ sleep 3 & sleep 6 & wait
9922 * $ sleep 3 & sleep 6 & wait
9926 * ^C <-- after ~4 sec from keyboard
9929 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9933 pid_t pid = bb_strtou(*argv, NULL, 10);
9934 if (errno || pid <= 0) {
9936 if (argv[0][0] == '%') {
9937 struct pipe *wait_pipe;
9938 ret = 127; /* bash compat for bad jobspecs */
9939 wait_pipe = parse_jobspec(*argv);
9941 ret = job_exited_or_stopped(wait_pipe);
9943 ret = wait_for_child_or_signal(wait_pipe, 0);
9944 //bash immediately deletes finished jobs from job table only in interactive mode,
9945 //we _always_ delete them at once. If we'd start keeping some dead jobs, this
9946 //(and more) would be necessary to avoid accumulating dead jobs:
9949 if (!wait_pipe->alive_cmds)
9950 delete_finished_job(wait_pipe);
9954 /* else: parse_jobspec() already emitted error msg */
9958 /* mimic bash message */
9959 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9961 continue; /* bash checks all argv[] */
9964 /* Do we have such child? */
9965 ret = waitpid(pid, &status, WNOHANG);
9969 if (errno == ECHILD) {
9970 if (pid == G.last_bg_pid) {
9971 /* "wait $!" but last bg task has already exited. Try:
9972 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9973 * In bash it prints exitcode 0, then 3.
9974 * In dash, it is 127.
9976 ret = G.last_bg_pid_exitcode;
9978 /* Example: "wait 1". mimic bash message */
9979 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9983 bb_perror_msg("wait %s", *argv);
9985 continue; /* bash checks all argv[] */
9988 /* Yes, and it still runs */
9989 ret = wait_for_child_or_signal(NULL, pid);
9991 /* Yes, and it just exited */
9992 process_wait_result(NULL, pid, status);
9993 ret = WEXITSTATUS(status);
9994 if (WIFSIGNALED(status))
9995 ret = 128 + WTERMSIG(status);
10003 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10004 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10007 def = bb_strtou(argv[1], NULL, 10);
10008 if (errno || def < def_min || argv[2]) {
10009 bb_error_msg("%s: bad arguments", argv[0]);
10017 #if ENABLE_HUSH_LOOPS
10018 static int FAST_FUNC builtin_break(char **argv)
10021 if (G.depth_of_loop == 0) {
10022 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10023 /* if we came from builtin_continue(), need to undo "= 1" */
10024 G.flag_break_continue = 0;
10025 return EXIT_SUCCESS; /* bash compat */
10027 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10029 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10030 if (depth == UINT_MAX)
10031 G.flag_break_continue = BC_BREAK;
10032 if (G.depth_of_loop < depth)
10033 G.depth_break_continue = G.depth_of_loop;
10035 return EXIT_SUCCESS;
10038 static int FAST_FUNC builtin_continue(char **argv)
10040 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10041 return builtin_break(argv);
10045 #if ENABLE_HUSH_FUNCTIONS
10046 static int FAST_FUNC builtin_return(char **argv)
10050 if (G_flag_return_in_progress != -1) {
10051 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10052 return EXIT_FAILURE; /* bash compat */
10055 G_flag_return_in_progress = 1;
10058 * out of range: wraps around at 256, does not error out
10059 * non-numeric param:
10060 * f() { false; return qwe; }; f; echo $?
10061 * bash: return: qwe: numeric argument required <== we do this
10062 * 255 <== we also do this
10064 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10069 #if ENABLE_HUSH_MEMLEAK
10070 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10075 # ifdef M_TRIM_THRESHOLD
10076 /* Optional. Reduces probability of false positives */
10079 /* Crude attempt to find where "free memory" starts,
10080 * sans fragmentation. */
10082 l = (unsigned long)p;
10085 if (l < (unsigned long)p) l = (unsigned long)p;
10091 struct mallinfo mi = mallinfo();
10092 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10093 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10097 if (!G.memleak_value)
10098 G.memleak_value = l;
10100 l -= G.memleak_value;
10107 /* Exitcode is "how many kilobytes we leaked since 1st call" */