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);
3377 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3378 ctx->ctx_inverted = 0;
3379 ctx->pipe->res_word = ctx->ctx_res_w;
3381 if (type != PIPE_BG || ctx->list_head == ctx->pipe) {
3383 ctx->pipe->followup = type;
3385 /* Necessary since && and || have more precedence than &:
3386 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3387 * in a backgrounded subshell.
3390 struct command *command;
3392 /* Is this actually the case? */
3393 pi = ctx->list_head;
3394 while (pi != ctx->pipe) {
3395 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3400 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3401 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3402 pi = xzalloc(sizeof(*pi));
3403 pi->followup = PIPE_BG;
3405 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3406 command = &pi->cmds[0];
3407 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3408 command->cmd_type = CMD_NORMAL;
3409 command->group = ctx->list_head;
3411 //TODO: is this correct?!
3412 command->group_as_string = xstrdup(ctx->as_string.data);
3414 /* Replace all pipes in ctx with one newly created */
3415 ctx->list_head = ctx->pipe = pi;
3418 /* Without this check, even just <enter> on command line generates
3419 * tree of three NOPs (!). Which is harmless but annoying.
3420 * IOW: it is safe to do it unconditionally. */
3423 || ctx->ctx_res_w == RES_FI
3425 #if ENABLE_HUSH_LOOPS
3426 || ctx->ctx_res_w == RES_DONE
3427 || ctx->ctx_res_w == RES_FOR
3428 || ctx->ctx_res_w == RES_IN
3430 #if ENABLE_HUSH_CASE
3431 || ctx->ctx_res_w == RES_ESAC
3435 debug_printf_parse("done_pipe: adding new pipe: "
3436 "not_null:%d ctx->ctx_res_w:%d\n",
3437 not_null, ctx->ctx_res_w);
3439 ctx->pipe->next = new_p;
3441 /* RES_THEN, RES_DO etc are "sticky" -
3442 * they remain set for pipes inside if/while.
3443 * This is used to control execution.
3444 * RES_FOR and RES_IN are NOT sticky (needed to support
3445 * cases where variable or value happens to match a keyword):
3447 #if ENABLE_HUSH_LOOPS
3448 if (ctx->ctx_res_w == RES_FOR
3449 || ctx->ctx_res_w == RES_IN)
3450 ctx->ctx_res_w = RES_NONE;
3452 #if ENABLE_HUSH_CASE
3453 if (ctx->ctx_res_w == RES_MATCH)
3454 ctx->ctx_res_w = RES_CASE_BODY;
3455 if (ctx->ctx_res_w == RES_CASE)
3456 ctx->ctx_res_w = RES_CASE_IN;
3458 ctx->command = NULL; /* trick done_command below */
3459 /* Create the memory for command, roughly:
3460 * ctx->pipe->cmds = new struct command;
3461 * ctx->command = &ctx->pipe->cmds[0];
3464 //debug_print_tree(ctx->list_head, 10);
3466 debug_printf_parse("done_pipe return\n");
3469 static void initialize_context(struct parse_context *ctx)
3471 memset(ctx, 0, sizeof(*ctx));
3472 ctx->pipe = ctx->list_head = new_pipe();
3473 /* Create the memory for command, roughly:
3474 * ctx->pipe->cmds = new struct command;
3475 * ctx->command = &ctx->pipe->cmds[0];
3480 /* If a reserved word is found and processed, parse context is modified
3481 * and 1 is returned.
3484 struct reserved_combo {
3487 unsigned char assignment_flag;
3491 FLAG_END = (1 << RES_NONE ),
3493 FLAG_IF = (1 << RES_IF ),
3494 FLAG_THEN = (1 << RES_THEN ),
3495 FLAG_ELIF = (1 << RES_ELIF ),
3496 FLAG_ELSE = (1 << RES_ELSE ),
3497 FLAG_FI = (1 << RES_FI ),
3499 # if ENABLE_HUSH_LOOPS
3500 FLAG_FOR = (1 << RES_FOR ),
3501 FLAG_WHILE = (1 << RES_WHILE),
3502 FLAG_UNTIL = (1 << RES_UNTIL),
3503 FLAG_DO = (1 << RES_DO ),
3504 FLAG_DONE = (1 << RES_DONE ),
3505 FLAG_IN = (1 << RES_IN ),
3507 # if ENABLE_HUSH_CASE
3508 FLAG_MATCH = (1 << RES_MATCH),
3509 FLAG_ESAC = (1 << RES_ESAC ),
3511 FLAG_START = (1 << RES_XXXX ),
3514 static const struct reserved_combo* match_reserved_word(o_string *word)
3516 /* Mostly a list of accepted follow-up reserved words.
3517 * FLAG_END means we are done with the sequence, and are ready
3518 * to turn the compound list into a command.
3519 * FLAG_START means the word must start a new compound list.
3521 static const struct reserved_combo reserved_list[] = {
3523 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3524 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3525 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3526 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3527 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3528 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3530 # if ENABLE_HUSH_LOOPS
3531 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3532 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3533 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3534 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3535 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3536 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3538 # if ENABLE_HUSH_CASE
3539 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3540 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3543 const struct reserved_combo *r;
3545 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3546 if (strcmp(word->data, r->literal) == 0)
3551 /* Return 0: not a keyword, 1: keyword
3553 static int reserved_word(o_string *word, struct parse_context *ctx)
3555 # if ENABLE_HUSH_CASE
3556 static const struct reserved_combo reserved_match = {
3557 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3560 const struct reserved_combo *r;
3562 if (word->has_quoted_part)
3564 r = match_reserved_word(word);
3568 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3569 # if ENABLE_HUSH_CASE
3570 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3571 /* "case word IN ..." - IN part starts first MATCH part */
3572 r = &reserved_match;
3575 if (r->flag == 0) { /* '!' */
3576 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3577 syntax_error("! ! command");
3578 ctx->ctx_res_w = RES_SNTX;
3580 ctx->ctx_inverted = 1;
3583 if (r->flag & FLAG_START) {
3584 struct parse_context *old;
3586 old = xmemdup(ctx, sizeof(*ctx));
3587 debug_printf_parse("push stack %p\n", old);
3588 initialize_context(ctx);
3590 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3591 syntax_error_at(word->data);
3592 ctx->ctx_res_w = RES_SNTX;
3595 /* "{...} fi" is ok. "{...} if" is not
3597 * if { echo foo; } then { echo bar; } fi */
3598 if (ctx->command->group)
3599 done_pipe(ctx, PIPE_SEQ);
3602 ctx->ctx_res_w = r->res;
3603 ctx->old_flag = r->flag;
3604 word->o_assignment = r->assignment_flag;
3605 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3607 if (ctx->old_flag & FLAG_END) {
3608 struct parse_context *old;
3610 done_pipe(ctx, PIPE_SEQ);
3611 debug_printf_parse("pop stack %p\n", ctx->stack);
3613 old->command->group = ctx->list_head;
3614 old->command->cmd_type = CMD_NORMAL;
3616 /* At this point, the compound command's string is in
3617 * ctx->as_string... except for the leading keyword!
3618 * Consider this example: "echo a | if true; then echo a; fi"
3619 * ctx->as_string will contain "true; then echo a; fi",
3620 * with "if " remaining in old->as_string!
3624 int len = old->as_string.length;
3625 /* Concatenate halves */
3626 o_addstr(&old->as_string, ctx->as_string.data);
3627 o_free_unsafe(&ctx->as_string);
3628 /* Find where leading keyword starts in first half */
3629 str = old->as_string.data + len;
3630 if (str > old->as_string.data)
3631 str--; /* skip whitespace after keyword */
3632 while (str > old->as_string.data && isalpha(str[-1]))
3634 /* Ugh, we're done with this horrid hack */
3635 old->command->group_as_string = xstrdup(str);
3636 debug_printf_parse("pop, remembering as:'%s'\n",
3637 old->command->group_as_string);
3640 *ctx = *old; /* physical copy */
3645 #endif /* HAS_KEYWORDS */
3647 /* Word is complete, look at it and update parsing context.
3648 * Normal return is 0. Syntax errors return 1.
3649 * Note: on return, word is reset, but not o_free'd!
3651 static int done_word(o_string *word, struct parse_context *ctx)
3653 struct command *command = ctx->command;
3655 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3656 if (word->length == 0 && !word->has_quoted_part) {
3657 debug_printf_parse("done_word return 0: true null, ignored\n");
3661 if (ctx->pending_redirect) {
3662 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3663 * only if run as "bash", not "sh" */
3664 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3666 * ...the word that follows the redirection operator
3667 * shall be subjected to tilde expansion, parameter expansion,
3668 * command substitution, arithmetic expansion, and quote
3669 * removal. Pathname expansion shall not be performed
3670 * on the word by a non-interactive shell; an interactive
3671 * shell may perform it, but shall do so only when
3672 * the expansion would result in one word."
3674 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3675 /* Cater for >\file case:
3676 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3677 * Same with heredocs:
3678 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3680 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3681 unbackslash(ctx->pending_redirect->rd_filename);
3682 /* Is it <<"HEREDOC"? */
3683 if (word->has_quoted_part) {
3684 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3687 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3688 ctx->pending_redirect = NULL;
3691 # if ENABLE_HUSH_CASE
3692 if (ctx->ctx_dsemicolon
3693 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3695 /* already done when ctx_dsemicolon was set to 1: */
3696 /* ctx->ctx_res_w = RES_MATCH; */
3697 ctx->ctx_dsemicolon = 0;
3700 if (!command->argv /* if it's the first word... */
3701 # if ENABLE_HUSH_LOOPS
3702 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3703 && ctx->ctx_res_w != RES_IN
3705 # if ENABLE_HUSH_CASE
3706 && ctx->ctx_res_w != RES_CASE
3709 int reserved = reserved_word(word, ctx);
3710 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3712 o_reset_to_empty_unquoted(word);
3713 debug_printf_parse("done_word return %d\n",
3714 (ctx->ctx_res_w == RES_SNTX));
3715 return (ctx->ctx_res_w == RES_SNTX);
3718 if (strcmp(word->data, "[[") == 0) {
3719 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3725 if (command->group) {
3726 /* "{ echo foo; } echo bar" - bad */
3727 syntax_error_at(word->data);
3728 debug_printf_parse("done_word return 1: syntax error, "
3729 "groups and arglists don't mix\n");
3733 /* If this word wasn't an assignment, next ones definitely
3734 * can't be assignments. Even if they look like ones. */
3735 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3736 && word->o_assignment != WORD_IS_KEYWORD
3738 word->o_assignment = NOT_ASSIGNMENT;
3740 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3741 command->assignment_cnt++;
3742 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3744 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3745 word->o_assignment = MAYBE_ASSIGNMENT;
3747 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3749 if (word->has_quoted_part
3750 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3751 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3752 /* (otherwise it's known to be not empty and is already safe) */
3754 /* exclude "$@" - it can expand to no word despite "" */
3755 char *p = word->data;
3756 while (p[0] == SPECIAL_VAR_SYMBOL
3757 && (p[1] & 0x7f) == '@'
3758 && p[2] == SPECIAL_VAR_SYMBOL
3763 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3764 debug_print_strings("word appended to argv", command->argv);
3767 #if ENABLE_HUSH_LOOPS
3768 if (ctx->ctx_res_w == RES_FOR) {
3769 if (word->has_quoted_part
3770 || !is_well_formed_var_name(command->argv[0], '\0')
3772 /* bash says just "not a valid identifier" */
3773 syntax_error("not a valid identifier in for");
3776 /* Force FOR to have just one word (variable name) */
3777 /* NB: basically, this makes hush see "for v in ..."
3778 * syntax as if it is "for v; in ...". FOR and IN become
3779 * two pipe structs in parse tree. */
3780 done_pipe(ctx, PIPE_SEQ);
3783 #if ENABLE_HUSH_CASE
3784 /* Force CASE to have just one word */
3785 if (ctx->ctx_res_w == RES_CASE) {
3786 done_pipe(ctx, PIPE_SEQ);
3790 o_reset_to_empty_unquoted(word);
3792 debug_printf_parse("done_word return 0\n");
3797 /* Peek ahead in the input to find out if we have a "&n" construct,
3798 * as in "2>&1", that represents duplicating a file descriptor.
3800 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3801 * REDIRFD_SYNTAX_ERR if syntax error,
3802 * REDIRFD_TO_FILE if no & was seen,
3803 * or the number found.
3806 #define parse_redir_right_fd(as_string, input) \
3807 parse_redir_right_fd(input)
3809 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3815 return REDIRFD_TO_FILE;
3817 ch = i_getch(input); /* get the & */
3818 nommu_addchr(as_string, ch);
3821 ch = i_getch(input);
3822 nommu_addchr(as_string, ch);
3823 return REDIRFD_CLOSE;
3827 while (ch != EOF && isdigit(ch)) {
3828 d = d*10 + (ch-'0');
3830 ch = i_getch(input);
3831 nommu_addchr(as_string, ch);
3836 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3838 bb_error_msg("ambiguous redirect");
3839 return REDIRFD_SYNTAX_ERR;
3842 /* Return code is 0 normal, 1 if a syntax error is detected
3844 static int parse_redirect(struct parse_context *ctx,
3847 struct in_str *input)
3849 struct command *command = ctx->command;
3850 struct redir_struct *redir;
3851 struct redir_struct **redirp;
3854 dup_num = REDIRFD_TO_FILE;
3855 if (style != REDIRECT_HEREDOC) {
3856 /* Check for a '>&1' type redirect */
3857 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3858 if (dup_num == REDIRFD_SYNTAX_ERR)
3861 int ch = i_peek(input);
3862 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3863 if (dup_num) { /* <<-... */
3864 ch = i_getch(input);
3865 nommu_addchr(&ctx->as_string, ch);
3870 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3871 int ch = i_peek(input);
3873 /* >|FILE redirect ("clobbering" >).
3874 * Since we do not support "set -o noclobber" yet,
3875 * >| and > are the same for now. Just eat |.
3877 ch = i_getch(input);
3878 nommu_addchr(&ctx->as_string, ch);
3882 /* Create a new redir_struct and append it to the linked list */
3883 redirp = &command->redirects;
3884 while ((redir = *redirp) != NULL) {
3885 redirp = &(redir->next);
3887 *redirp = redir = xzalloc(sizeof(*redir));
3888 /* redir->next = NULL; */
3889 /* redir->rd_filename = NULL; */
3890 redir->rd_type = style;
3891 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3893 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3894 redir_table[style].descrip);
3896 redir->rd_dup = dup_num;
3897 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3898 /* Erik had a check here that the file descriptor in question
3899 * is legit; I postpone that to "run time"
3900 * A "-" representation of "close me" shows up as a -3 here */
3901 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3902 redir->rd_fd, redir->rd_dup);
3904 #if 0 /* Instead we emit error message at run time */
3905 if (ctx->pending_redirect) {
3906 /* For example, "cmd > <file" */
3907 die_if_script("syntax error: %s", "invalid redirect");
3910 /* Set ctx->pending_redirect, so we know what to do at the
3911 * end of the next parsed word. */
3912 ctx->pending_redirect = redir;
3917 /* If a redirect is immediately preceded by a number, that number is
3918 * supposed to tell which file descriptor to redirect. This routine
3919 * looks for such preceding numbers. In an ideal world this routine
3920 * needs to handle all the following classes of redirects...
3921 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3922 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3923 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3924 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3926 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3928 * ... If n is quoted, the number shall not be recognized as part of
3929 * the redirection expression. For example:
3931 * writes the character 2 into file a"
3932 * We are getting it right by setting ->has_quoted_part on any \<char>
3934 * A -1 return means no valid number was found,
3935 * the caller should use the appropriate default for this redirection.
3937 static int redirect_opt_num(o_string *o)
3941 if (o->data == NULL)
3943 num = bb_strtou(o->data, NULL, 10);
3944 if (errno || num < 0)
3946 o_reset_to_empty_unquoted(o);
3951 #define fetch_till_str(as_string, input, word, skip_tabs) \
3952 fetch_till_str(input, word, skip_tabs)
3954 static char *fetch_till_str(o_string *as_string,
3955 struct in_str *input,
3959 o_string heredoc = NULL_O_STRING;
3961 int prev = 0; /* not \ */
3967 ch = i_getch(input);
3969 nommu_addchr(as_string, ch);
3970 if ((ch == '\n' || ch == EOF)
3971 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3973 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3974 heredoc.data[past_EOL] = '\0';
3975 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3976 return heredoc.data;
3978 while (ch == '\n') {
3979 o_addchr(&heredoc, ch);
3982 past_EOL = heredoc.length;
3984 ch = i_getch(input);
3986 nommu_addchr(as_string, ch);
3987 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3991 o_free_unsafe(&heredoc);
3994 o_addchr(&heredoc, ch);
3995 nommu_addchr(as_string, ch);
3996 if (prev == '\\' && ch == '\\')
3997 /* Correctly handle foo\\<eol> (not a line cont.) */
3998 prev = 0; /* not \ */
4004 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4005 * and load them all. There should be exactly heredoc_cnt of them.
4007 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4009 struct pipe *pi = ctx->list_head;
4011 while (pi && heredoc_cnt) {
4013 struct command *cmd = pi->cmds;
4015 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4017 cmd->argv ? cmd->argv[0] : "NONE");
4018 for (i = 0; i < pi->num_cmds; i++) {
4019 struct redir_struct *redir = cmd->redirects;
4021 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4022 i, cmd->argv ? cmd->argv[0] : "NONE");
4024 if (redir->rd_type == REDIRECT_HEREDOC) {
4027 redir->rd_type = REDIRECT_HEREDOC2;
4028 /* redir->rd_dup is (ab)used to indicate <<- */
4029 p = fetch_till_str(&ctx->as_string, input,
4030 redir->rd_filename, redir->rd_dup);
4032 syntax_error("unexpected EOF in here document");
4035 free(redir->rd_filename);
4036 redir->rd_filename = p;
4039 redir = redir->next;
4046 /* Should be 0. If it isn't, it's a parse error */
4048 bb_error_msg_and_die("heredoc BUG 2");
4054 static int run_list(struct pipe *pi);
4056 #define parse_stream(pstring, input, end_trigger) \
4057 parse_stream(input, end_trigger)
4059 static struct pipe *parse_stream(char **pstring,
4060 struct in_str *input,
4064 #if !ENABLE_HUSH_FUNCTIONS
4065 #define parse_group(dest, ctx, input, ch) \
4066 parse_group(ctx, input, ch)
4068 static int parse_group(o_string *dest, struct parse_context *ctx,
4069 struct in_str *input, int ch)
4071 /* dest contains characters seen prior to ( or {.
4072 * Typically it's empty, but for function defs,
4073 * it contains function name (without '()'). */
4074 struct pipe *pipe_list;
4076 struct command *command = ctx->command;
4078 debug_printf_parse("parse_group entered\n");
4079 #if ENABLE_HUSH_FUNCTIONS
4080 if (ch == '(' && !dest->has_quoted_part) {
4082 if (done_word(dest, ctx))
4085 goto skip; /* (... */
4086 if (command->argv[1]) { /* word word ... (... */
4087 syntax_error_unexpected_ch('(');
4090 /* it is "word(..." or "word (..." */
4092 ch = i_getch(input);
4093 while (ch == ' ' || ch == '\t');
4095 syntax_error_unexpected_ch(ch);
4098 nommu_addchr(&ctx->as_string, ch);
4100 ch = i_getch(input);
4101 while (ch == ' ' || ch == '\t' || ch == '\n');
4103 syntax_error_unexpected_ch(ch);
4106 nommu_addchr(&ctx->as_string, ch);
4107 command->cmd_type = CMD_FUNCDEF;
4112 #if 0 /* Prevented by caller */
4113 if (command->argv /* word [word]{... */
4114 || dest->length /* word{... */
4115 || dest->has_quoted_part /* ""{... */
4118 debug_printf_parse("parse_group return 1: "
4119 "syntax error, groups and arglists don't mix\n");
4124 #if ENABLE_HUSH_FUNCTIONS
4130 command->cmd_type = CMD_SUBSHELL;
4132 /* bash does not allow "{echo...", requires whitespace */
4134 if (ch != ' ' && ch != '\t' && ch != '\n'
4135 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4137 syntax_error_unexpected_ch(ch);
4141 ch = i_getch(input);
4142 nommu_addchr(&ctx->as_string, ch);
4148 # define as_string NULL
4150 char *as_string = NULL;
4152 pipe_list = parse_stream(&as_string, input, endch);
4155 o_addstr(&ctx->as_string, as_string);
4157 /* empty ()/{} or parse error? */
4158 if (!pipe_list || pipe_list == ERR_PTR) {
4159 /* parse_stream already emitted error msg */
4162 debug_printf_parse("parse_group return 1: "
4163 "parse_stream returned %p\n", pipe_list);
4166 command->group = pipe_list;
4168 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4169 command->group_as_string = as_string;
4170 debug_printf_parse("end of group, remembering as:'%s'\n",
4171 command->group_as_string);
4175 debug_printf_parse("parse_group return 0\n");
4177 /* command remains "open", available for possible redirects */
4180 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4185 ch = i_getch(input);
4188 ch2 = i_peek(input);
4191 /* backslash+newline, skip it */
4196 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4204 ch2 = i_peek2(input);
4207 /* backslash+newline, skip it */
4213 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4214 /* Subroutines for copying $(...) and `...` things */
4215 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4217 static int add_till_single_quote(o_string *dest, struct in_str *input)
4220 int ch = i_getch(input);
4222 syntax_error_unterm_ch('\'');
4230 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4231 static int add_till_double_quote(o_string *dest, struct in_str *input)
4234 int ch = i_getch(input);
4236 syntax_error_unterm_ch('"');
4241 if (ch == '\\') { /* \x. Copy both chars. */
4243 ch = i_getch(input);
4247 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4252 //if (ch == '$') ...
4255 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4257 * "Within the backquoted style of command substitution, backslash
4258 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4259 * The search for the matching backquote shall be satisfied by the first
4260 * backquote found without a preceding backslash; during this search,
4261 * if a non-escaped backquote is encountered within a shell comment,
4262 * a here-document, an embedded command substitution of the $(command)
4263 * form, or a quoted string, undefined results occur. A single-quoted
4264 * or double-quoted string that begins, but does not end, within the
4265 * "`...`" sequence produces undefined results."
4267 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4269 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4272 int ch = i_getch(input);
4276 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4277 ch = i_getch(input);
4281 && (!in_dquote || ch != '"')
4283 o_addchr(dest, '\\');
4287 syntax_error_unterm_ch('`');
4293 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4294 * quoting and nested ()s.
4295 * "With the $(command) style of command substitution, all characters
4296 * following the open parenthesis to the matching closing parenthesis
4297 * constitute the command. Any valid shell script can be used for command,
4298 * except a script consisting solely of redirections which produces
4299 * unspecified results."
4301 * echo $(echo '(TEST)' BEST) (TEST) BEST
4302 * echo $(echo 'TEST)' BEST) TEST) BEST
4303 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4305 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4306 * can contain arbitrary constructs, just like $(cmd).
4307 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4308 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4310 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4311 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4314 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4315 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4316 char end_char2 = end_ch >> 8;
4318 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4321 ch = i_getch(input);
4323 syntax_error_unterm_ch(end_ch);
4327 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4333 /* we look for closing )) of $((EXPR)) */
4334 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4335 i_getch(input); /* eat second ')' */
4340 if (ch == '(' || ch == '{') {
4341 ch = (ch == '(' ? ')' : '}');
4342 if (!add_till_closing_bracket(dest, input, ch))
4348 if (!add_till_single_quote(dest, input))
4354 if (!add_till_double_quote(dest, input))
4360 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4366 /* \x. Copy verbatim. Important for \(, \) */
4367 ch = i_getch(input);
4369 syntax_error_unterm_ch(')');
4374 /* "backslash+newline", ignore both */
4375 o_delchr(dest); /* undo insertion of '\' */
4385 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4387 /* Return code: 0 for OK, 1 for syntax error */
4389 #define parse_dollar(as_string, dest, input, quote_mask) \
4390 parse_dollar(dest, input, quote_mask)
4391 #define as_string NULL
4393 static int parse_dollar(o_string *as_string,
4395 struct in_str *input, unsigned char quote_mask)
4397 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4399 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4401 ch = i_getch(input);
4402 nommu_addchr(as_string, ch);
4404 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4406 debug_printf_parse(": '%c'\n", ch);
4407 o_addchr(dest, ch | quote_mask);
4409 ch = i_peek_and_eat_bkslash_nl(input);
4410 if (!isalnum(ch) && ch != '_') {
4411 /* End of variable name reached */
4414 ch = i_getch(input);
4415 nommu_addchr(as_string, ch);
4417 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4418 } else if (isdigit(ch)) {
4420 ch = i_getch(input);
4421 nommu_addchr(as_string, ch);
4422 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4423 debug_printf_parse(": '%c'\n", ch);
4424 o_addchr(dest, ch | quote_mask);
4425 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4426 } else switch (ch) {
4428 case '!': /* last bg pid */
4429 case '?': /* last exit code */
4430 case '#': /* number of args */
4431 case '*': /* args */
4432 case '@': /* args */
4433 goto make_one_char_var;
4435 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4437 ch = i_getch(input); /* eat '{' */
4438 nommu_addchr(as_string, ch);
4440 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4441 /* It should be ${?}, or ${#var},
4442 * or even ${?+subst} - operator acting on a special variable,
4443 * or the beginning of variable name.
4446 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4449 syntax_error_unterm_str("${name}");
4450 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4453 nommu_addchr(as_string, ch);
4456 /* It's possible to just call add_till_closing_bracket() at this point.
4457 * However, this regresses some of our testsuite cases
4458 * which check invalid constructs like ${%}.
4459 * Oh well... let's check that the var name part is fine... */
4465 debug_printf_parse(": '%c'\n", ch);
4467 ch = i_getch(input);
4468 nommu_addchr(as_string, ch);
4472 if (!isalnum(ch) && ch != '_') {
4474 unsigned char last_ch;
4475 /* handle parameter expansions
4476 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4478 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4479 goto bad_dollar_syntax;
4481 /* Eat everything until closing '}' (or ':') */
4485 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4487 /* It's ${var:N[:M]} thing */
4488 end_ch = '}' * 0x100 + ':';
4490 if (BASH_PATTERN_SUBST
4493 /* It's ${var/[/]pattern[/repl]} thing */
4494 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4496 nommu_addchr(as_string, '/');
4499 end_ch = '}' * 0x100 + '/';
4505 #if ENABLE_HUSH_DOLLAR_OPS
4506 last_ch = add_till_closing_bracket(dest, input, end_ch);
4507 if (last_ch == 0) /* error? */
4510 #error Simple code to only allow ${var} is not implemented
4513 o_addstr(as_string, dest->data + pos);
4514 o_addchr(as_string, last_ch);
4517 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4518 && (end_ch & 0xff00)
4520 /* close the first block: */
4521 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4522 /* while parsing N from ${var:N[:M]}
4523 * or pattern from ${var/[/]pattern[/repl]} */
4524 if ((end_ch & 0xff) == last_ch) {
4525 /* got ':' or '/'- parse the rest */
4530 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4531 /* it's ${var:N} - emulate :999999999 */
4532 o_addstr(dest, "999999999");
4533 } /* else: it's ${var/[/]pattern} */
4538 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4541 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4545 ch = i_getch(input);
4546 nommu_addchr(as_string, ch);
4547 # if ENABLE_FEATURE_SH_MATH
4548 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4549 ch = i_getch(input);
4550 nommu_addchr(as_string, ch);
4551 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4552 o_addchr(dest, /*quote_mask |*/ '+');
4555 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4556 return 0; /* error */
4558 o_addstr(as_string, dest->data + pos);
4559 o_addchr(as_string, ')');
4560 o_addchr(as_string, ')');
4562 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4566 # if ENABLE_HUSH_TICK
4567 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4568 o_addchr(dest, quote_mask | '`');
4571 if (!add_till_closing_bracket(dest, input, ')'))
4572 return 0; /* error */
4574 o_addstr(as_string, dest->data + pos);
4575 o_addchr(as_string, ')');
4577 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4583 ch = i_getch(input);
4584 nommu_addchr(as_string, ch);
4585 ch = i_peek_and_eat_bkslash_nl(input);
4586 if (isalnum(ch)) { /* it's $_name or $_123 */
4591 /* TODO: $_ and $-: */
4592 /* $_ Shell or shell script name; or last argument of last command
4593 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4594 * but in command's env, set to full pathname used to invoke it */
4595 /* $- Option flags set by set builtin or shell options (-i etc) */
4597 o_addQchr(dest, '$');
4599 debug_printf_parse("parse_dollar return 1 (ok)\n");
4605 # if BASH_PATTERN_SUBST
4606 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4607 encode_string(dest, input, dquote_end, process_bkslash)
4609 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4610 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4611 encode_string(dest, input, dquote_end)
4613 #define as_string NULL
4617 # if BASH_PATTERN_SUBST
4618 /* all parameters are needed, no macro tricks */
4620 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4621 encode_string(as_string, dest, input, dquote_end)
4624 static int encode_string(o_string *as_string,
4626 struct in_str *input,
4628 int process_bkslash)
4630 #if !BASH_PATTERN_SUBST
4631 const int process_bkslash = 1;
4637 ch = i_getch(input);
4639 nommu_addchr(as_string, ch);
4640 if (ch == dquote_end) { /* may be only '"' or EOF */
4641 debug_printf_parse("encode_string return 1 (ok)\n");
4644 /* note: can't move it above ch == dquote_end check! */
4646 syntax_error_unterm_ch('"');
4647 return 0; /* error */
4651 next = i_peek(input);
4653 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4654 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4655 if (process_bkslash && ch == '\\') {
4657 syntax_error("\\<eof>");
4661 * "The backslash retains its special meaning [in "..."]
4662 * only when followed by one of the following characters:
4663 * $, `, ", \, or <newline>. A double quote may be quoted
4664 * within double quotes by preceding it with a backslash."
4665 * NB: in (unquoted) heredoc, above does not apply to ",
4666 * therefore we check for it by "next == dquote_end" cond.
4668 if (next == dquote_end || strchr("$`\\\n", next)) {
4669 ch = i_getch(input); /* eat next */
4671 goto again; /* skip \<newline> */
4672 } /* else: ch remains == '\\', and we double it below: */
4673 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4674 nommu_addchr(as_string, ch);
4678 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4679 debug_printf_parse("encode_string return 0: "
4680 "parse_dollar returned 0 (error)\n");
4685 #if ENABLE_HUSH_TICK
4687 //unsigned pos = dest->length;
4688 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4689 o_addchr(dest, 0x80 | '`');
4690 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4691 return 0; /* error */
4692 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4693 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4697 o_addQchr(dest, ch);
4703 * Scan input until EOF or end_trigger char.
4704 * Return a list of pipes to execute, or NULL on EOF
4705 * or if end_trigger character is met.
4706 * On syntax error, exit if shell is not interactive,
4707 * reset parsing machinery and start parsing anew,
4708 * or return ERR_PTR.
4710 static struct pipe *parse_stream(char **pstring,
4711 struct in_str *input,
4714 struct parse_context ctx;
4715 o_string dest = NULL_O_STRING;
4718 /* Single-quote triggers a bypass of the main loop until its mate is
4719 * found. When recursing, quote state is passed in via dest->o_expflags.
4721 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4722 end_trigger ? end_trigger : 'X');
4725 /* If very first arg is "" or '', dest.data may end up NULL.
4726 * Preventing this: */
4727 o_addchr(&dest, '\0');
4730 /* We used to separate words on $IFS here. This was wrong.
4731 * $IFS is used only for word splitting when $var is expanded,
4732 * here we should use blank chars as separators, not $IFS
4735 if (MAYBE_ASSIGNMENT != 0)
4736 dest.o_assignment = MAYBE_ASSIGNMENT;
4737 initialize_context(&ctx);
4740 const char *is_blank;
4741 const char *is_special;
4745 redir_type redir_style;
4747 ch = i_getch(input);
4748 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4749 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4754 syntax_error_unterm_str("here document");
4757 if (end_trigger == ')') {
4758 syntax_error_unterm_ch('(');
4761 if (end_trigger == '}') {
4762 syntax_error_unterm_ch('{');
4766 if (done_word(&dest, &ctx)) {
4770 done_pipe(&ctx, PIPE_SEQ);
4772 /* If we got nothing... */
4773 /* (this makes bare "&" cmd a no-op.
4774 * bash says: "syntax error near unexpected token '&'") */
4775 if (pi->num_cmds == 0
4776 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4782 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4784 *pstring = ctx.as_string.data;
4786 o_free_unsafe(&ctx.as_string);
4789 debug_printf_parse("parse_stream return %p\n", pi);
4792 nommu_addchr(&ctx.as_string, ch);
4796 next = i_peek(input);
4798 is_special = "{}<>;&|()#'" /* special outside of "str" */
4799 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4800 /* Are { and } special here? */
4801 if (ctx.command->argv /* word [word]{... - non-special */
4802 || dest.length /* word{... - non-special */
4803 || dest.has_quoted_part /* ""{... - non-special */
4804 || (next != ';' /* }; - special */
4805 && next != ')' /* }) - special */
4806 && next != '(' /* {( - special */
4807 && next != '&' /* }& and }&& ... - special */
4808 && next != '|' /* }|| ... - special */
4809 && !strchr(defifs, next) /* {word - non-special */
4812 /* They are not special, skip "{}" */
4815 is_special = strchr(is_special, ch);
4816 is_blank = strchr(defifs, ch);
4818 if (!is_special && !is_blank) { /* ordinary char */
4820 o_addQchr(&dest, ch);
4821 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4822 || dest.o_assignment == WORD_IS_KEYWORD)
4824 && is_well_formed_var_name(dest.data, '=')
4826 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4827 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4833 if (done_word(&dest, &ctx)) {
4837 /* Is this a case when newline is simply ignored?
4839 * "cmd | <newline> cmd ..."
4840 * "case ... in <newline> word) ..."
4842 if (IS_NULL_CMD(ctx.command)
4843 && dest.length == 0 && !dest.has_quoted_part
4845 /* This newline can be ignored. But...
4846 * Without check #1, interactive shell
4847 * ignores even bare <newline>,
4848 * and shows the continuation prompt:
4849 * ps1_prompt$ <enter>
4850 * ps2> _ <=== wrong, should be ps1
4851 * Without check #2, "cmd & <newline>"
4852 * is similarly mistreated.
4853 * (BTW, this makes "cmd & cmd"
4854 * and "cmd && cmd" non-orthogonal.
4855 * Really, ask yourself, why
4856 * "cmd && <newline>" doesn't start
4857 * cmd but waits for more input?
4860 struct pipe *pi = ctx.list_head;
4861 if (pi->num_cmds != 0 /* check #1 */
4862 && pi->followup != PIPE_BG /* check #2 */
4867 /* Treat newline as a command separator. */
4868 done_pipe(&ctx, PIPE_SEQ);
4869 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4871 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4876 dest.o_assignment = MAYBE_ASSIGNMENT;
4877 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4879 /* note: if (is_blank) continue;
4880 * will still trigger for us */
4884 /* "cmd}" or "cmd }..." without semicolon or &:
4885 * } is an ordinary char in this case, even inside { cmd; }
4886 * Pathological example: { ""}; } should exec "}" cmd
4889 if (dest.length != 0 /* word} */
4890 || dest.has_quoted_part /* ""} */
4894 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4895 /* Generally, there should be semicolon: "cmd; }"
4896 * However, bash allows to omit it if "cmd" is
4897 * a group. Examples:
4900 * { echo 0 >&2 | { echo 1; } }
4901 * { while false; do :; done }
4902 * { case a in b) ;; esac }
4904 if (ctx.command->group)
4908 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4909 /* Can't be an end of {cmd}, skip the check */
4910 goto skip_end_trigger;
4911 /* else: } does terminate a group */
4914 if (end_trigger && end_trigger == ch
4915 && (ch != ';' || heredoc_cnt == 0)
4916 #if ENABLE_HUSH_CASE
4918 || ctx.ctx_res_w != RES_MATCH
4919 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4924 /* This is technically valid:
4925 * { cat <<HERE; }; echo Ok
4929 * but we don't support this.
4930 * We require heredoc to be in enclosing {}/(),
4933 syntax_error_unterm_str("here document");
4936 if (done_word(&dest, &ctx)) {
4939 done_pipe(&ctx, PIPE_SEQ);
4940 dest.o_assignment = MAYBE_ASSIGNMENT;
4941 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4942 /* Do we sit outside of any if's, loops or case's? */
4944 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4948 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4950 *pstring = ctx.as_string.data;
4952 o_free_unsafe(&ctx.as_string);
4955 debug_printf_parse("parse_stream return %p: "
4956 "end_trigger char found\n",
4958 return ctx.list_head;
4965 /* Catch <, > before deciding whether this word is
4966 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4969 redir_fd = redirect_opt_num(&dest);
4970 if (done_word(&dest, &ctx)) {
4973 redir_style = REDIRECT_OVERWRITE;
4975 redir_style = REDIRECT_APPEND;
4976 ch = i_getch(input);
4977 nommu_addchr(&ctx.as_string, ch);
4980 else if (next == '(') {
4981 syntax_error(">(process) not supported");
4985 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4987 continue; /* back to top of while (1) */
4989 redir_fd = redirect_opt_num(&dest);
4990 if (done_word(&dest, &ctx)) {
4993 redir_style = REDIRECT_INPUT;
4995 redir_style = REDIRECT_HEREDOC;
4997 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4998 ch = i_getch(input);
4999 nommu_addchr(&ctx.as_string, ch);
5000 } else if (next == '>') {
5001 redir_style = REDIRECT_IO;
5002 ch = i_getch(input);
5003 nommu_addchr(&ctx.as_string, ch);
5006 else if (next == '(') {
5007 syntax_error("<(process) not supported");
5011 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5013 continue; /* back to top of while (1) */
5015 if (dest.length == 0 && !dest.has_quoted_part) {
5016 /* skip "#comment" */
5019 if (ch == EOF || ch == '\n')
5022 /* note: we do not add it to &ctx.as_string */
5024 nommu_addchr(&ctx.as_string, '\n');
5025 continue; /* back to top of while (1) */
5030 /* It's "\<newline>" */
5032 /* Remove trailing '\' from ctx.as_string */
5033 ctx.as_string.data[--ctx.as_string.length] = '\0';
5035 ch = i_getch(input); /* eat it */
5036 continue; /* back to top of while (1) */
5041 if (dest.o_assignment == MAYBE_ASSIGNMENT
5042 /* check that we are not in word in "a=1 2>word b=1": */
5043 && !ctx.pending_redirect
5045 /* ch is a special char and thus this word
5046 * cannot be an assignment */
5047 dest.o_assignment = NOT_ASSIGNMENT;
5048 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5051 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5054 case '#': /* non-comment #: "echo a#b" etc */
5055 o_addQchr(&dest, ch);
5059 syntax_error("\\<eof>");
5062 ch = i_getch(input);
5063 /* note: ch != '\n' (that case does not reach this place) */
5064 o_addchr(&dest, '\\');
5065 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5066 o_addchr(&dest, ch);
5067 nommu_addchr(&ctx.as_string, ch);
5068 /* Example: echo Hello \2>file
5069 * we need to know that word 2 is quoted */
5070 dest.has_quoted_part = 1;
5073 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5074 debug_printf_parse("parse_stream parse error: "
5075 "parse_dollar returned 0 (error)\n");
5080 dest.has_quoted_part = 1;
5081 if (next == '\'' && !ctx.pending_redirect) {
5082 insert_empty_quoted_str_marker:
5083 nommu_addchr(&ctx.as_string, next);
5084 i_getch(input); /* eat second ' */
5085 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5086 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5089 ch = i_getch(input);
5091 syntax_error_unterm_ch('\'');
5094 nommu_addchr(&ctx.as_string, ch);
5097 o_addqchr(&dest, ch);
5102 dest.has_quoted_part = 1;
5103 if (next == '"' && !ctx.pending_redirect)
5104 goto insert_empty_quoted_str_marker;
5105 if (dest.o_assignment == NOT_ASSIGNMENT)
5106 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5107 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5109 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5111 #if ENABLE_HUSH_TICK
5113 USE_FOR_NOMMU(unsigned pos;)
5115 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5116 o_addchr(&dest, '`');
5117 USE_FOR_NOMMU(pos = dest.length;)
5118 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5121 o_addstr(&ctx.as_string, dest.data + pos);
5122 o_addchr(&ctx.as_string, '`');
5124 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5125 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5130 #if ENABLE_HUSH_CASE
5133 if (done_word(&dest, &ctx)) {
5136 done_pipe(&ctx, PIPE_SEQ);
5137 #if ENABLE_HUSH_CASE
5138 /* Eat multiple semicolons, detect
5139 * whether it means something special */
5144 ch = i_getch(input);
5145 nommu_addchr(&ctx.as_string, ch);
5146 if (ctx.ctx_res_w == RES_CASE_BODY) {
5147 ctx.ctx_dsemicolon = 1;
5148 ctx.ctx_res_w = RES_MATCH;
5154 /* We just finished a cmd. New one may start
5155 * with an assignment */
5156 dest.o_assignment = MAYBE_ASSIGNMENT;
5157 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5160 if (done_word(&dest, &ctx)) {
5164 ch = i_getch(input);
5165 nommu_addchr(&ctx.as_string, ch);
5166 done_pipe(&ctx, PIPE_AND);
5168 done_pipe(&ctx, PIPE_BG);
5172 if (done_word(&dest, &ctx)) {
5175 #if ENABLE_HUSH_CASE
5176 if (ctx.ctx_res_w == RES_MATCH)
5177 break; /* we are in case's "word | word)" */
5179 if (next == '|') { /* || */
5180 ch = i_getch(input);
5181 nommu_addchr(&ctx.as_string, ch);
5182 done_pipe(&ctx, PIPE_OR);
5184 /* we could pick up a file descriptor choice here
5185 * with redirect_opt_num(), but bash doesn't do it.
5186 * "echo foo 2| cat" yields "foo 2". */
5191 #if ENABLE_HUSH_CASE
5192 /* "case... in [(]word)..." - skip '(' */
5193 if (ctx.ctx_res_w == RES_MATCH
5194 && ctx.command->argv == NULL /* not (word|(... */
5195 && dest.length == 0 /* not word(... */
5196 && dest.has_quoted_part == 0 /* not ""(... */
5202 if (parse_group(&dest, &ctx, input, ch) != 0) {
5207 #if ENABLE_HUSH_CASE
5208 if (ctx.ctx_res_w == RES_MATCH)
5212 /* proper use of this character is caught by end_trigger:
5213 * if we see {, we call parse_group(..., end_trigger='}')
5214 * and it will match } earlier (not here). */
5215 syntax_error_unexpected_ch(ch);
5216 G.last_exitcode = 2;
5220 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5225 G.last_exitcode = 1;
5228 struct parse_context *pctx;
5229 IF_HAS_KEYWORDS(struct parse_context *p2;)
5231 /* Clean up allocated tree.
5232 * Sample for finding leaks on syntax error recovery path.
5233 * Run it from interactive shell, watch pmap `pidof hush`.
5234 * while if false; then false; fi; do break; fi
5235 * Samples to catch leaks at execution:
5236 * while if (true | { true;}); then echo ok; fi; do break; done
5237 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5241 /* Update pipe/command counts,
5242 * otherwise freeing may miss some */
5243 done_pipe(pctx, PIPE_SEQ);
5244 debug_printf_clean("freeing list %p from ctx %p\n",
5245 pctx->list_head, pctx);
5246 debug_print_tree(pctx->list_head, 0);
5247 free_pipe_list(pctx->list_head);
5248 debug_printf_clean("freed list %p\n", pctx->list_head);
5250 o_free_unsafe(&pctx->as_string);
5252 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5256 IF_HAS_KEYWORDS(pctx = p2;)
5257 } while (HAS_KEYWORDS && pctx);
5270 /*** Execution routines ***/
5272 /* Expansion can recurse, need forward decls: */
5273 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5274 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5275 #define expand_string_to_string(str, do_unbackslash) \
5276 expand_string_to_string(str)
5278 static char *expand_string_to_string(const char *str, int do_unbackslash);
5279 #if ENABLE_HUSH_TICK
5280 static int process_command_subs(o_string *dest, const char *s);
5283 /* expand_strvec_to_strvec() takes a list of strings, expands
5284 * all variable references within and returns a pointer to
5285 * a list of expanded strings, possibly with larger number
5286 * of strings. (Think VAR="a b"; echo $VAR).
5287 * This new list is allocated as a single malloc block.
5288 * NULL-terminated list of char* pointers is at the beginning of it,
5289 * followed by strings themselves.
5290 * Caller can deallocate entire list by single free(list). */
5292 /* A horde of its helpers come first: */
5294 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5296 while (--len >= 0) {
5299 #if ENABLE_HUSH_BRACE_EXPANSION
5300 if (c == '{' || c == '}') {
5301 /* { -> \{, } -> \} */
5303 /* And now we want to add { or } and continue:
5306 * luckily, just falling through achieves this.
5312 /* \z -> \\\z; \<eol> -> \\<eol> */
5317 o_addchr(o, *str++);
5323 /* Store given string, finalizing the word and starting new one whenever
5324 * we encounter IFS char(s). This is used for expanding variable values.
5325 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5326 * Return in *ended_with_ifs:
5327 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5329 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5331 int last_is_ifs = 0;
5336 if (!*str) /* EOL - do not finalize word */
5338 word_len = strcspn(str, G.ifs);
5340 /* We have WORD_LEN leading non-IFS chars */
5341 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5342 o_addblock(output, str, word_len);
5344 /* Protect backslashes against globbing up :)
5345 * Example: "v='\*'; echo b$v" prints "b\*"
5346 * (and does not try to glob on "*")
5348 o_addblock_duplicate_backslash(output, str, word_len);
5349 /*/ Why can't we do it easier? */
5350 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5351 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5355 if (!*str) /* EOL - do not finalize word */
5359 /* We know str here points to at least one IFS char */
5361 str += strspn(str, G.ifs); /* skip IFS chars */
5362 if (!*str) /* EOL - do not finalize word */
5365 /* Start new word... but not always! */
5366 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5367 if (output->has_quoted_part
5368 /* Case "v=' a'; echo $v":
5369 * here nothing precedes the space in $v expansion,
5370 * therefore we should not finish the word
5371 * (IOW: if there *is* word to finalize, only then do it):
5373 || (n > 0 && output->data[output->length - 1])
5375 o_addchr(output, '\0');
5376 debug_print_list("expand_on_ifs", output, n);
5377 n = o_save_ptr(output, n);
5382 *ended_with_ifs = last_is_ifs;
5383 debug_print_list("expand_on_ifs[1]", output, n);
5387 /* Helper to expand $((...)) and heredoc body. These act as if
5388 * they are in double quotes, with the exception that they are not :).
5389 * Just the rules are similar: "expand only $var and `cmd`"
5391 * Returns malloced string.
5392 * As an optimization, we return NULL if expansion is not needed.
5394 #if !BASH_PATTERN_SUBST
5395 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5396 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5397 encode_then_expand_string(str)
5399 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5401 #if !BASH_PATTERN_SUBST
5402 const int do_unbackslash = 1;
5405 struct in_str input;
5406 o_string dest = NULL_O_STRING;
5408 if (!strchr(str, '$')
5409 && !strchr(str, '\\')
5410 #if ENABLE_HUSH_TICK
5411 && !strchr(str, '`')
5417 /* We need to expand. Example:
5418 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5420 setup_string_in_str(&input, str);
5421 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5422 //TODO: error check (encode_string returns 0 on error)?
5423 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5424 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5425 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5426 o_free_unsafe(&dest);
5430 #if ENABLE_FEATURE_SH_MATH
5431 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5433 arith_state_t math_state;
5437 math_state.lookupvar = get_local_var_value;
5438 math_state.setvar = set_local_var_from_halves;
5439 //math_state.endofname = endofname;
5440 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5441 res = arith(&math_state, exp_str ? exp_str : arg);
5444 *errmsg_p = math_state.errmsg;
5445 if (math_state.errmsg)
5446 die_if_script(math_state.errmsg);
5451 #if BASH_PATTERN_SUBST
5452 /* ${var/[/]pattern[/repl]} helpers */
5453 static char *strstr_pattern(char *val, const char *pattern, int *size)
5456 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5457 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5464 /* Optimization: if "*pat" did not match the start of "string",
5465 * we know that "tring", "ring" etc will not match too:
5467 if (pattern[0] == '*')
5472 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5474 char *result = NULL;
5475 unsigned res_len = 0;
5476 unsigned repl_len = strlen(repl);
5480 char *s = strstr_pattern(val, pattern, &size);
5484 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5485 memcpy(result + res_len, val, s - val);
5487 strcpy(result + res_len, repl);
5488 res_len += repl_len;
5489 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5495 if (val[0] && result) {
5496 result = xrealloc(result, res_len + strlen(val) + 1);
5497 strcpy(result + res_len, val);
5498 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5500 debug_printf_varexp("result:'%s'\n", result);
5503 #endif /* BASH_PATTERN_SUBST */
5506 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5508 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5510 const char *val = NULL;
5511 char *to_be_freed = NULL;
5516 char exp_save = exp_save; /* for compiler */
5517 char *exp_saveptr; /* points to expansion operator */
5518 char *exp_word = exp_word; /* for compiler */
5521 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5523 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5525 first_char = arg[0] = arg0 & 0x7f;
5528 if (first_char == '#' /* ${#... */
5529 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5531 /* It must be length operator: ${#var} */
5535 /* Maybe handle parameter expansion */
5536 if (exp_saveptr /* if 2nd char is one of expansion operators */
5537 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5539 /* ${?:0}, ${#[:]%0} etc */
5540 exp_saveptr = var + 1;
5542 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5543 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5545 exp_op = exp_save = *exp_saveptr;
5547 exp_word = exp_saveptr + 1;
5548 if (exp_op == ':') {
5549 exp_op = *exp_word++;
5550 //TODO: try ${var:} and ${var:bogus} in non-bash config
5552 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5554 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5559 *exp_saveptr = '\0';
5560 } /* else: it's not an expansion op, but bare ${var} */
5563 /* Look up the variable in question */
5564 if (isdigit(var[0])) {
5565 /* parse_dollar should have vetted var for us */
5566 int n = xatoi_positive(var);
5567 if (n < G.global_argc)
5568 val = G.global_argv[n];
5569 /* else val remains NULL: $N with too big N */
5573 val = utoa(G.root_pid);
5575 case '!': /* bg pid */
5576 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5578 case '?': /* exitcode */
5579 val = utoa(G.last_exitcode);
5581 case '#': /* argc */
5582 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5585 val = get_local_var_value(var);
5589 /* Handle any expansions */
5590 if (exp_op == 'L') {
5591 reinit_unicode_for_hush();
5592 debug_printf_expand("expand: length(%s)=", val);
5593 val = utoa(val ? unicode_strlen(val) : 0);
5594 debug_printf_expand("%s\n", val);
5595 } else if (exp_op) {
5596 if (exp_op == '%' || exp_op == '#') {
5597 /* Standard-mandated substring removal ops:
5598 * ${parameter%word} - remove smallest suffix pattern
5599 * ${parameter%%word} - remove largest suffix pattern
5600 * ${parameter#word} - remove smallest prefix pattern
5601 * ${parameter##word} - remove largest prefix pattern
5603 * Word is expanded to produce a glob pattern.
5604 * Then var's value is matched to it and matching part removed.
5606 if (val && val[0]) {
5610 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5611 if (exp_op == *exp_word) /* ## or %% */
5613 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5615 exp_word = exp_exp_word;
5616 /* HACK ALERT. We depend here on the fact that
5617 * G.global_argv and results of utoa and get_local_var_value
5618 * are actually in writable memory:
5619 * scan_and_match momentarily stores NULs there. */
5621 loc = scan_and_match(t, exp_word, scan_flags);
5622 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5623 // exp_op, t, exp_word, loc);
5625 if (loc) { /* match was found */
5626 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5627 val = loc; /* take right part */
5629 val = to_be_freed = xstrndup(val, loc - val); /* left */
5633 #if BASH_PATTERN_SUBST
5634 else if (exp_op == '/' || exp_op == '\\') {
5635 /* It's ${var/[/]pattern[/repl]} thing.
5636 * Note that in encoded form it has TWO parts:
5637 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5638 * and if // is used, it is encoded as \:
5639 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5641 /* Empty variable always gives nothing: */
5642 // "v=''; echo ${v/*/w}" prints "", not "w"
5643 if (val && val[0]) {
5644 /* pattern uses non-standard expansion.
5645 * repl should be unbackslashed and globbed
5646 * by the usual expansion rules:
5648 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5649 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5650 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5651 * v='a bz'; echo ${v/a*z/\z} prints "z"
5652 * (note that a*z _pattern_ is never globbed!)
5654 char *pattern, *repl, *t;
5655 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5657 pattern = xstrdup(exp_word);
5658 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5659 *p++ = SPECIAL_VAR_SYMBOL;
5661 p = strchr(p, SPECIAL_VAR_SYMBOL);
5663 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5664 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5665 /* HACK ALERT. We depend here on the fact that
5666 * G.global_argv and results of utoa and get_local_var_value
5667 * are actually in writable memory:
5668 * replace_pattern momentarily stores NULs there. */
5670 to_be_freed = replace_pattern(t,
5672 (repl ? repl : exp_word),
5674 if (to_be_freed) /* at least one replace happened */
5680 #endif /* BASH_PATTERN_SUBST */
5681 else if (exp_op == ':') {
5682 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5683 /* It's ${var:N[:M]} bashism.
5684 * Note that in encoded form it has TWO parts:
5685 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5690 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5693 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5694 *p++ = SPECIAL_VAR_SYMBOL;
5696 p = strchr(p, SPECIAL_VAR_SYMBOL);
5698 len = expand_and_evaluate_arith(exp_word, &errmsg);
5701 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5702 if (len >= 0) { /* bash compat: len < 0 is illegal */
5704 /* negative beg counts from the end */
5705 beg = (arith_t)strlen(val) + beg;
5706 if (beg < 0) /* ${v: -999999} is "" */
5709 debug_printf_varexp("from val:'%s'\n", val);
5710 if (len == 0 || !val || beg >= strlen(val)) {
5714 /* Paranoia. What if user entered 9999999999999
5715 * which fits in arith_t but not int? */
5718 val = to_be_freed = xstrndup(val + beg, len);
5720 debug_printf_varexp("val:'%s'\n", val);
5722 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5724 die_if_script("malformed ${%s:...}", var);
5727 } else { /* one of "-=+?" */
5728 /* Standard-mandated substitution ops:
5729 * ${var?word} - indicate error if unset
5730 * If var is unset, word (or a message indicating it is unset
5731 * if word is null) is written to standard error
5732 * and the shell exits with a non-zero exit status.
5733 * Otherwise, the value of var is substituted.
5734 * ${var-word} - use default value
5735 * If var is unset, word is substituted.
5736 * ${var=word} - assign and use default value
5737 * If var is unset, word is assigned to var.
5738 * In all cases, final value of var is substituted.
5739 * ${var+word} - use alternative value
5740 * If var is unset, null is substituted.
5741 * Otherwise, word is substituted.
5743 * Word is subjected to tilde expansion, parameter expansion,
5744 * command substitution, and arithmetic expansion.
5745 * If word is not needed, it is not expanded.
5747 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5748 * but also treat null var as if it is unset.
5750 int use_word = (!val || ((exp_save == ':') && !val[0]));
5752 use_word = !use_word;
5753 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5754 (exp_save == ':') ? "true" : "false", use_word);
5756 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5758 exp_word = to_be_freed;
5759 if (exp_op == '?') {
5760 /* mimic bash message */
5761 die_if_script("%s: %s",
5763 exp_word[0] ? exp_word : "parameter null or not set"
5765 //TODO: how interactive bash aborts expansion mid-command?
5770 if (exp_op == '=') {
5771 /* ${var=[word]} or ${var:=[word]} */
5772 if (isdigit(var[0]) || var[0] == '#') {
5773 /* mimic bash message */
5774 die_if_script("$%s: cannot assign in this way", var);
5777 char *new_var = xasprintf("%s=%s", var, val);
5778 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5782 } /* one of "-=+?" */
5784 *exp_saveptr = exp_save;
5790 *to_be_freed_pp = to_be_freed;
5794 /* Expand all variable references in given string, adding words to list[]
5795 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5796 * to be filled). This routine is extremely tricky: has to deal with
5797 * variables/parameters with whitespace, $* and $@, and constructs like
5798 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5799 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5801 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5802 * expansion of right-hand side of assignment == 1-element expand.
5804 char cant_be_null = 0; /* only bit 0x80 matters */
5805 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5808 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5809 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5810 debug_print_list("expand_vars_to_list", output, n);
5811 n = o_save_ptr(output, n);
5812 debug_print_list("expand_vars_to_list[0]", output, n);
5814 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5816 char *to_be_freed = NULL;
5817 const char *val = NULL;
5818 #if ENABLE_HUSH_TICK
5819 o_string subst_result = NULL_O_STRING;
5821 #if ENABLE_FEATURE_SH_MATH
5822 char arith_buf[sizeof(arith_t)*3 + 2];
5826 o_addchr(output, '\0');
5827 n = o_save_ptr(output, n);
5831 o_addblock(output, arg, p - arg);
5832 debug_print_list("expand_vars_to_list[1]", output, n);
5834 p = strchr(p, SPECIAL_VAR_SYMBOL);
5836 /* Fetch special var name (if it is indeed one of them)
5837 * and quote bit, force the bit on if singleword expansion -
5838 * important for not getting v=$@ expand to many words. */
5839 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5841 /* Is this variable quoted and thus expansion can't be null?
5842 * "$@" is special. Even if quoted, it can still
5843 * expand to nothing (not even an empty string),
5844 * thus it is excluded. */
5845 if ((first_ch & 0x7f) != '@')
5846 cant_be_null |= first_ch;
5848 switch (first_ch & 0x7f) {
5849 /* Highest bit in first_ch indicates that var is double-quoted */
5853 if (!G.global_argv[1])
5856 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5857 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5858 while (G.global_argv[i]) {
5859 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5860 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5861 if (G.global_argv[i++][0] && G.global_argv[i]) {
5862 /* this argv[] is not empty and not last:
5863 * put terminating NUL, start new word */
5864 o_addchr(output, '\0');
5865 debug_print_list("expand_vars_to_list[2]", output, n);
5866 n = o_save_ptr(output, n);
5867 debug_print_list("expand_vars_to_list[3]", output, n);
5871 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5872 * and in this case should treat it like '$*' - see 'else...' below */
5873 if (first_ch == ('@'|0x80) /* quoted $@ */
5874 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5877 o_addQstr(output, G.global_argv[i]);
5878 if (++i >= G.global_argc)
5880 o_addchr(output, '\0');
5881 debug_print_list("expand_vars_to_list[4]", output, n);
5882 n = o_save_ptr(output, n);
5884 } else { /* quoted $* (or v="$@" case): add as one word */
5886 o_addQstr(output, G.global_argv[i]);
5887 if (!G.global_argv[++i])
5890 o_addchr(output, G.ifs[0]);
5892 output->has_quoted_part = 1;
5896 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5897 /* "Empty variable", used to make "" etc to not disappear */
5898 output->has_quoted_part = 1;
5900 cant_be_null = 0x80;
5902 #if ENABLE_HUSH_TICK
5903 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5904 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5906 /* Can't just stuff it into output o_string,
5907 * expanded result may need to be globbed
5909 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5910 G.last_exitcode = process_command_subs(&subst_result, arg);
5911 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5912 val = subst_result.data;
5915 #if ENABLE_FEATURE_SH_MATH
5916 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5919 arg++; /* skip '+' */
5920 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5921 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5922 res = expand_and_evaluate_arith(arg, NULL);
5923 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5924 sprintf(arith_buf, ARITH_FMT, res);
5930 val = expand_one_var(&to_be_freed, arg, &p);
5931 IF_HUSH_TICK(store_val:)
5932 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5933 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5934 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5935 if (val && val[0]) {
5936 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5939 } else { /* quoted $VAR, val will be appended below */
5940 output->has_quoted_part = 1;
5941 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5942 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5945 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5947 if (val && val[0]) {
5948 o_addQstr(output, val);
5952 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5953 * Do the check to avoid writing to a const string. */
5954 if (*p != SPECIAL_VAR_SYMBOL)
5955 *p = SPECIAL_VAR_SYMBOL;
5957 #if ENABLE_HUSH_TICK
5958 o_free(&subst_result);
5961 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5965 o_addchr(output, '\0');
5966 n = o_save_ptr(output, n);
5968 debug_print_list("expand_vars_to_list[a]", output, n);
5969 /* this part is literal, and it was already pre-quoted
5970 * if needed (much earlier), do not use o_addQstr here! */
5971 o_addstr_with_NUL(output, arg);
5972 debug_print_list("expand_vars_to_list[b]", output, n);
5973 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5974 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5977 /* allow to reuse list[n] later without re-growth */
5978 output->has_empty_slot = 1;
5980 o_addchr(output, '\0');
5986 static char **expand_variables(char **argv, unsigned expflags)
5990 o_string output = NULL_O_STRING;
5992 output.o_expflags = expflags;
5996 n = expand_vars_to_list(&output, n, *argv);
5999 debug_print_list("expand_variables", &output, n);
6001 /* output.data (malloced in one block) gets returned in "list" */
6002 list = o_finalize_list(&output, n);
6003 debug_print_strings("expand_variables[1]", list);
6007 static char **expand_strvec_to_strvec(char **argv)
6009 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6013 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6015 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6019 /* Used for expansion of right hand of assignments,
6020 * $((...)), heredocs, variable espansion parts.
6022 * NB: should NOT do globbing!
6023 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6025 static char *expand_string_to_string(const char *str, int do_unbackslash)
6027 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6028 const int do_unbackslash = 1;
6030 char *argv[2], **list;
6032 debug_printf_expand("string_to_string<='%s'\n", str);
6033 /* This is generally an optimization, but it also
6034 * handles "", which otherwise trips over !list[0] check below.
6035 * (is this ever happens that we actually get str="" here?)
6037 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6038 //TODO: Can use on strings with \ too, just unbackslash() them?
6039 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6040 return xstrdup(str);
6043 argv[0] = (char*)str;
6045 list = expand_variables(argv, do_unbackslash
6046 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6047 : EXP_FLAG_SINGLEWORD
6050 if (!list[0] || list[1])
6051 bb_error_msg_and_die("BUG in varexp2");
6052 /* actually, just move string 2*sizeof(char*) bytes back */
6053 overlapping_strcpy((char*)list, list[0]);
6055 unbackslash((char*)list);
6056 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6060 /* Used for "eval" builtin and case string */
6061 static char* expand_strvec_to_string(char **argv)
6065 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6066 /* Convert all NULs to spaces */
6071 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6072 bb_error_msg_and_die("BUG in varexp3");
6073 /* bash uses ' ' regardless of $IFS contents */
6078 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6079 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6083 static char **expand_assignments(char **argv, int count)
6088 G.expanded_assignments = p = NULL;
6089 /* Expand assignments into one string each */
6090 for (i = 0; i < count; i++) {
6091 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6093 G.expanded_assignments = NULL;
6098 static void switch_off_special_sigs(unsigned mask)
6101 while ((mask >>= 1) != 0) {
6105 #if ENABLE_HUSH_TRAP
6107 if (G_traps[sig] && !G_traps[sig][0])
6108 /* trap is '', has to remain SIG_IGN */
6111 G_traps[sig] = NULL;
6114 /* We are here only if no trap or trap was not '' */
6115 install_sighandler(sig, SIG_DFL);
6121 void re_execute_shell(char ***to_free, const char *s,
6122 char *g_argv0, char **g_argv,
6123 char **builtin_argv) NORETURN;
6125 static void reset_traps_to_defaults(void)
6127 /* This function is always called in a child shell
6128 * after fork (not vfork, NOMMU doesn't use this function).
6130 IF_HUSH_TRAP(unsigned sig;)
6133 /* Child shells are not interactive.
6134 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6135 * Testcase: (while :; do :; done) + ^Z should background.
6136 * Same goes for SIGTERM, SIGHUP, SIGINT.
6138 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6139 if (!G_traps && !mask)
6140 return; /* already no traps and no special sigs */
6142 /* Switch off special sigs */
6143 switch_off_special_sigs(mask);
6144 # if ENABLE_HUSH_JOB
6145 G_fatal_sig_mask = 0;
6147 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6148 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6149 * remain set in G.special_sig_mask */
6151 # if ENABLE_HUSH_TRAP
6155 /* Reset all sigs to default except ones with empty traps */
6156 for (sig = 0; sig < NSIG; sig++) {
6158 continue; /* no trap: nothing to do */
6159 if (!G_traps[sig][0])
6160 continue; /* empty trap: has to remain SIG_IGN */
6161 /* sig has non-empty trap, reset it: */
6163 G_traps[sig] = NULL;
6164 /* There is no signal for trap 0 (EXIT) */
6167 install_sighandler(sig, pick_sighandler(sig));
6174 static void re_execute_shell(char ***to_free, const char *s,
6175 char *g_argv0, char **g_argv,
6176 char **builtin_argv) NORETURN;
6177 static void re_execute_shell(char ***to_free, const char *s,
6178 char *g_argv0, char **g_argv,
6179 char **builtin_argv)
6181 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6182 /* delims + 2 * (number of bytes in printed hex numbers) */
6183 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6184 char *heredoc_argv[4];
6185 struct variable *cur;
6186 # if ENABLE_HUSH_FUNCTIONS
6187 struct function *funcp;
6191 unsigned long long empty_trap_mask;
6193 if (!g_argv0) { /* heredoc */
6194 argv = heredoc_argv;
6195 argv[0] = (char *) G.argv0_for_re_execing;
6196 argv[1] = (char *) "-<";
6197 argv[2] = (char *) s;
6199 pp = &argv[3]; /* used as pointer to empty environment */
6205 if (pp) while (*pp++)
6208 empty_trap_mask = 0;
6211 for (sig = 1; sig < NSIG; sig++) {
6212 if (G_traps[sig] && !G_traps[sig][0])
6213 empty_trap_mask |= 1LL << sig;
6217 sprintf(param_buf, NOMMU_HACK_FMT
6218 , (unsigned) G.root_pid
6219 , (unsigned) G.root_ppid
6220 , (unsigned) G.last_bg_pid
6221 , (unsigned) G.last_exitcode
6224 IF_HUSH_LOOPS(, G.depth_of_loop)
6226 # undef NOMMU_HACK_FMT
6227 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6228 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6231 for (cur = G.top_var; cur; cur = cur->next) {
6232 if (!cur->flg_export || cur->flg_read_only)
6235 # if ENABLE_HUSH_FUNCTIONS
6236 for (funcp = G.top_func; funcp; funcp = funcp->next)
6242 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6243 *pp++ = (char *) G.argv0_for_re_execing;
6245 for (cur = G.top_var; cur; cur = cur->next) {
6246 if (strcmp(cur->varstr, hush_version_str) == 0)
6248 if (cur->flg_read_only) {
6249 *pp++ = (char *) "-R";
6250 *pp++ = cur->varstr;
6251 } else if (!cur->flg_export) {
6252 *pp++ = (char *) "-V";
6253 *pp++ = cur->varstr;
6256 # if ENABLE_HUSH_FUNCTIONS
6257 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6258 *pp++ = (char *) "-F";
6259 *pp++ = funcp->name;
6260 *pp++ = funcp->body_as_string;
6263 /* We can pass activated traps here. Say, -Tnn:trap_string
6265 * However, POSIX says that subshells reset signals with traps
6267 * I tested bash-3.2 and it not only does that with true subshells
6268 * of the form ( list ), but with any forked children shells.
6269 * I set trap "echo W" WINCH; and then tried:
6271 * { echo 1; sleep 20; echo 2; } &
6272 * while true; do echo 1; sleep 20; echo 2; break; done &
6273 * true | { echo 1; sleep 20; echo 2; } | cat
6275 * In all these cases sending SIGWINCH to the child shell
6276 * did not run the trap. If I add trap "echo V" WINCH;
6277 * _inside_ group (just before echo 1), it works.
6279 * I conclude it means we don't need to pass active traps here.
6281 *pp++ = (char *) "-c";
6284 while (*++builtin_argv)
6285 *pp++ = *builtin_argv;
6286 *pp++ = (char *) "";
6291 /* *pp = NULL; - is already there */
6295 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6296 /* Don't propagate SIG_IGN to the child */
6297 if (SPECIAL_JOBSTOP_SIGS != 0)
6298 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6299 execve(bb_busybox_exec_path, argv, pp);
6300 /* Fallback. Useful for init=/bin/hush usage etc */
6301 if (argv[0][0] == '/')
6302 execve(argv[0], argv, pp);
6303 xfunc_error_retval = 127;
6304 bb_error_msg_and_die("can't re-execute the shell");
6306 #endif /* !BB_MMU */
6309 static int run_and_free_list(struct pipe *pi);
6311 /* Executing from string: eval, sh -c '...'
6312 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6313 * end_trigger controls how often we stop parsing
6314 * NUL: parse all, execute, return
6315 * ';': parse till ';' or newline, execute, repeat till EOF
6317 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6319 /* Why we need empty flag?
6320 * An obscure corner case "false; ``; echo $?":
6321 * empty command in `` should still set $? to 0.
6322 * But we can't just set $? to 0 at the start,
6323 * this breaks "false; echo `echo $?`" case.
6327 struct pipe *pipe_list;
6329 #if ENABLE_HUSH_INTERACTIVE
6330 if (end_trigger == ';')
6331 inp->promptmode = 0; /* PS1 */
6333 pipe_list = parse_stream(NULL, inp, end_trigger);
6334 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6335 /* If we are in "big" script
6336 * (not in `cmd` or something similar)...
6338 if (pipe_list == ERR_PTR && end_trigger == ';') {
6339 /* Discard cached input (rest of line) */
6340 int ch = inp->last_char;
6341 while (ch != EOF && ch != '\n') {
6342 //bb_error_msg("Discarded:'%c'", ch);
6347 /* This stream isn't empty */
6351 if (!pipe_list && empty)
6352 G.last_exitcode = 0;
6355 debug_print_tree(pipe_list, 0);
6356 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6357 run_and_free_list(pipe_list);
6359 if (G_flag_return_in_progress == 1)
6364 static void parse_and_run_string(const char *s)
6366 struct in_str input;
6367 setup_string_in_str(&input, s);
6368 parse_and_run_stream(&input, '\0');
6371 static void parse_and_run_file(FILE *f)
6373 struct in_str input;
6374 setup_file_in_str(&input, f);
6375 parse_and_run_stream(&input, ';');
6378 #if ENABLE_HUSH_TICK
6379 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6384 char **to_free = NULL;
6388 pid = BB_MMU ? xfork() : xvfork();
6389 if (pid == 0) { /* child */
6390 disable_restore_tty_pgrp_on_exit();
6391 /* Process substitution is not considered to be usual
6392 * 'command execution'.
6393 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6400 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6401 close(channel[0]); /* NB: close _first_, then move fd! */
6402 xmove_fd(channel[1], 1);
6403 /* Prevent it from trying to handle ctrl-z etc */
6404 IF_HUSH_JOB(G.run_list_level = 1;)
6405 # if ENABLE_HUSH_TRAP
6406 /* Awful hack for `trap` or $(trap).
6408 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6409 * contains an example where "trap" is executed in a subshell:
6411 * save_traps=$(trap)
6413 * eval "$save_traps"
6415 * Standard does not say that "trap" in subshell shall print
6416 * parent shell's traps. It only says that its output
6417 * must have suitable form, but then, in the above example
6418 * (which is not supposed to be normative), it implies that.
6420 * bash (and probably other shell) does implement it
6421 * (traps are reset to defaults, but "trap" still shows them),
6422 * but as a result, "trap" logic is hopelessly messed up:
6425 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6426 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6427 * # true | trap <--- trap is in subshell - no output (ditto)
6428 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6429 * trap -- 'echo Ho' SIGWINCH
6430 * # echo `(trap)` <--- in subshell in subshell - output
6431 * trap -- 'echo Ho' SIGWINCH
6432 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6433 * trap -- 'echo Ho' SIGWINCH
6435 * The rules when to forget and when to not forget traps
6436 * get really complex and nonsensical.
6438 * Our solution: ONLY bare $(trap) or `trap` is special.
6440 s = skip_whitespace(s);
6441 if (is_prefixed_with(s, "trap")
6442 && skip_whitespace(s + 4)[0] == '\0'
6444 static const char *const argv[] = { NULL, NULL };
6445 builtin_trap((char**)argv);
6446 fflush_all(); /* important */
6451 reset_traps_to_defaults();
6452 parse_and_run_string(s);
6453 _exit(G.last_exitcode);
6455 /* We re-execute after vfork on NOMMU. This makes this script safe:
6456 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6457 * huge=`cat BIG` # was blocking here forever
6460 re_execute_shell(&to_free,
6470 # if ENABLE_HUSH_FAST
6472 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6473 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6474 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6476 enable_restore_tty_pgrp_on_exit();
6481 return remember_FILE(xfdopen_for_read(channel[0]));
6484 /* Return code is exit status of the process that is run. */
6485 static int process_command_subs(o_string *dest, const char *s)
6488 struct in_str pipe_str;
6490 int status, ch, eol_cnt;
6492 fp = generate_stream_from_string(s, &pid);
6494 /* Now send results of command back into original context */
6495 setup_file_in_str(&pipe_str, fp);
6497 while ((ch = i_getch(&pipe_str)) != EOF) {
6503 o_addchr(dest, '\n');
6506 o_addQchr(dest, ch);
6509 debug_printf("done reading from `cmd` pipe, closing it\n");
6510 fclose_and_forget(fp);
6511 /* We need to extract exitcode. Test case
6512 * "true; echo `sleep 1; false` $?"
6514 safe_waitpid(pid, &status, 0);
6515 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6516 return WEXITSTATUS(status);
6518 #endif /* ENABLE_HUSH_TICK */
6521 static void setup_heredoc(struct redir_struct *redir)
6523 struct fd_pair pair;
6526 /* the _body_ of heredoc (misleading field name) */
6527 const char *heredoc = redir->rd_filename;
6534 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6535 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6539 len = strlen(heredoc);
6541 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6543 xmove_fd(pair.rd, redir->rd_fd);
6545 /* Try writing without forking. Newer kernels have
6546 * dynamically growing pipes. Must use non-blocking write! */
6549 written = write(pair.wr, heredoc, len);
6560 ndelay_off(pair.wr);
6562 /* Okay, pipe buffer was not big enough */
6563 /* Note: we must not create a stray child (bastard? :)
6564 * for the unsuspecting parent process. Child creates a grandchild
6565 * and exits before parent execs the process which consumes heredoc
6566 * (that exec happens after we return from this function) */
6573 disable_restore_tty_pgrp_on_exit();
6574 pid = BB_MMU ? xfork() : xvfork();
6578 close(redir->rd_fd); /* read side of the pipe */
6580 full_write(pair.wr, heredoc, len); /* may loop or block */
6583 /* Delegate blocking writes to another process */
6584 xmove_fd(pair.wr, STDOUT_FILENO);
6585 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6589 #if ENABLE_HUSH_FAST
6591 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6593 enable_restore_tty_pgrp_on_exit();
6599 wait(NULL); /* wait till child has died */
6605 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6606 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6609 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6613 if (sq) while (sq[i].orig_fd >= 0) {
6614 /* If we collide with an already moved fd... */
6615 if (fd == sq[i].moved_to) {
6616 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6617 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6618 if (sq[i].moved_to < 0) /* what? */
6622 if (fd == sq[i].orig_fd) {
6623 /* Example: echo Hello >/dev/null 1>&2 */
6624 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6630 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6632 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6633 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6634 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6635 if (sq[i].moved_to < 0 && errno != EBADF)
6637 sq[i+1].orig_fd = -1; /* end marker */
6641 /* fd: redirect wants this fd to be used (e.g. 3>file).
6642 * Move all conflicting internally used fds,
6643 * and remember them so that we can restore them later.
6645 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6647 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6650 #if ENABLE_HUSH_INTERACTIVE
6651 if (fd != 0 && fd == G.interactive_fd) {
6652 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6653 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6654 return 1; /* "we closed fd" */
6657 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6658 * (1) Redirect in a forked child. No need to save FILEs' fds,
6659 * we aren't going to use them anymore, ok to trash.
6660 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6661 * but how are we doing to restore them?
6662 * "fileno(fd) = new_fd" can't be done.
6667 /* If this one of script's fds? */
6668 if (save_FILEs_on_redirect(fd, avoid_fd))
6669 return 1; /* yes. "we closed fd" */
6671 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6672 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6673 return 0; /* "we did not close fd" */
6676 static void restore_redirects(struct squirrel *sq)
6681 while (sq[i].orig_fd >= 0) {
6682 if (sq[i].moved_to >= 0) {
6683 /* We simply die on error */
6684 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6685 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6687 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6688 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6689 close(sq[i].orig_fd);
6696 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6698 restore_redirected_FILEs();
6701 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6702 * and stderr if they are redirected. */
6703 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6706 struct redir_struct *redir;
6708 for (redir = prog->redirects; redir; redir = redir->next) {
6709 if (redir->rd_type == REDIRECT_HEREDOC2) {
6710 /* "rd_fd<<HERE" case */
6711 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6712 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6714 debug_printf_parse("set heredoc '%s'\n",
6715 redir->rd_filename);
6716 setup_heredoc(redir);
6720 if (redir->rd_dup == REDIRFD_TO_FILE) {
6721 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6723 if (redir->rd_filename == NULL) {
6726 * "cmd >" (no filename)
6727 * "cmd > <file" (2nd redirect starts too early)
6729 die_if_script("syntax error: %s", "invalid redirect");
6732 mode = redir_table[redir->rd_type].mode;
6733 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6734 openfd = open_or_warn(p, mode);
6737 /* Error message from open_or_warn can be lost
6738 * if stderr has been redirected, but bash
6739 * and ash both lose it as well
6740 * (though zsh doesn't!)
6745 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6746 openfd = redir->rd_dup;
6749 if (openfd != redir->rd_fd) {
6750 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6751 if (openfd == REDIRFD_CLOSE) {
6752 /* "rd_fd >&-" means "close me" */
6754 /* ^^^ optimization: saving may already
6755 * have closed it. If not... */
6756 close(redir->rd_fd);
6759 xdup2(openfd, redir->rd_fd);
6760 if (redir->rd_dup == REDIRFD_TO_FILE)
6761 /* "rd_fd > FILE" */
6763 /* else: "rd_fd > rd_dup" */
6770 static char *find_in_path(const char *arg)
6773 const char *PATH = get_local_var_value("PATH");
6779 const char *end = strchrnul(PATH, ':');
6780 int sz = end - PATH; /* must be int! */
6784 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6786 /* We have xxx::yyyy in $PATH,
6787 * it means "use current dir" */
6790 if (access(ret, F_OK) == 0)
6803 static const struct built_in_command *find_builtin_helper(const char *name,
6804 const struct built_in_command *x,
6805 const struct built_in_command *end)
6808 if (strcmp(name, x->b_cmd) != 0) {
6812 debug_printf_exec("found builtin '%s'\n", name);
6817 static const struct built_in_command *find_builtin1(const char *name)
6819 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6821 static const struct built_in_command *find_builtin(const char *name)
6823 const struct built_in_command *x = find_builtin1(name);
6826 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6829 #if ENABLE_HUSH_FUNCTIONS
6830 static struct function **find_function_slot(const char *name)
6832 struct function **funcpp = &G.top_func;
6834 if (strcmp(name, (*funcpp)->name) == 0) {
6837 funcpp = &(*funcpp)->next;
6842 static const struct function *find_function(const char *name)
6844 const struct function *funcp = *find_function_slot(name);
6846 debug_printf_exec("found function '%s'\n", name);
6850 /* Note: takes ownership on name ptr */
6851 static struct function *new_function(char *name)
6853 struct function **funcpp = find_function_slot(name);
6854 struct function *funcp = *funcpp;
6856 if (funcp != NULL) {
6857 struct command *cmd = funcp->parent_cmd;
6858 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6860 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6862 /* Note: if !funcp->body, do not free body_as_string!
6863 * This is a special case of "-F name body" function:
6864 * body_as_string was not malloced! */
6866 free_pipe_list(funcp->body);
6868 free(funcp->body_as_string);
6872 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6873 cmd->argv[0] = funcp->name;
6874 cmd->group = funcp->body;
6876 cmd->group_as_string = funcp->body_as_string;
6880 debug_printf_exec("remembering new function '%s'\n", name);
6881 funcp = *funcpp = xzalloc(sizeof(*funcp));
6882 /*funcp->next = NULL;*/
6889 # if ENABLE_HUSH_UNSET
6890 static void unset_func(const char *name)
6892 struct function **funcpp = find_function_slot(name);
6893 struct function *funcp = *funcpp;
6895 if (funcp != NULL) {
6896 debug_printf_exec("freeing function '%s'\n", funcp->name);
6897 *funcpp = funcp->next;
6898 /* funcp is unlinked now, deleting it.
6899 * Note: if !funcp->body, the function was created by
6900 * "-F name body", do not free ->body_as_string
6901 * and ->name as they were not malloced. */
6903 free_pipe_list(funcp->body);
6906 free(funcp->body_as_string);
6915 #define exec_function(to_free, funcp, argv) \
6916 exec_function(funcp, argv)
6918 static void exec_function(char ***to_free,
6919 const struct function *funcp,
6920 char **argv) NORETURN;
6921 static void exec_function(char ***to_free,
6922 const struct function *funcp,
6928 argv[0] = G.global_argv[0];
6929 G.global_argv = argv;
6930 G.global_argc = n = 1 + string_array_len(argv + 1);
6931 /* On MMU, funcp->body is always non-NULL */
6932 n = run_list(funcp->body);
6936 re_execute_shell(to_free,
6937 funcp->body_as_string,
6944 static int run_function(const struct function *funcp, char **argv)
6950 save_and_replace_G_args(&sv, argv);
6952 /* "we are in function, ok to use return" */
6953 sv_flg = G_flag_return_in_progress;
6954 G_flag_return_in_progress = -1;
6955 # if ENABLE_HUSH_LOCAL
6956 G.func_nest_level++;
6959 /* On MMU, funcp->body is always non-NULL */
6962 /* Function defined by -F */
6963 parse_and_run_string(funcp->body_as_string);
6964 rc = G.last_exitcode;
6968 rc = run_list(funcp->body);
6971 # if ENABLE_HUSH_LOCAL
6973 struct variable *var;
6974 struct variable **var_pp;
6976 var_pp = &G.top_var;
6977 while ((var = *var_pp) != NULL) {
6978 if (var->func_nest_level < G.func_nest_level) {
6979 var_pp = &var->next;
6983 if (var->flg_export)
6984 bb_unsetenv(var->varstr);
6985 /* Remove from global list */
6986 *var_pp = var->next;
6992 G.func_nest_level--;
6995 G_flag_return_in_progress = sv_flg;
6997 restore_G_args(&sv, argv);
7001 #endif /* ENABLE_HUSH_FUNCTIONS */
7005 #define exec_builtin(to_free, x, argv) \
7006 exec_builtin(x, argv)
7008 #define exec_builtin(to_free, x, argv) \
7009 exec_builtin(to_free, argv)
7011 static void exec_builtin(char ***to_free,
7012 const struct built_in_command *x,
7013 char **argv) NORETURN;
7014 static void exec_builtin(char ***to_free,
7015 const struct built_in_command *x,
7021 rcode = x->b_function(argv);
7026 /* On NOMMU, we must never block!
7027 * Example: { sleep 99 | read line; } & echo Ok
7029 re_execute_shell(to_free,
7038 static void execvp_or_die(char **argv) NORETURN;
7039 static void execvp_or_die(char **argv)
7042 debug_printf_exec("execing '%s'\n", argv[0]);
7043 /* Don't propagate SIG_IGN to the child */
7044 if (SPECIAL_JOBSTOP_SIGS != 0)
7045 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7046 execvp(argv[0], argv);
7048 if (errno == EACCES) e = 126;
7049 if (errno == ENOENT) e = 127;
7050 bb_perror_msg("can't execute '%s'", argv[0]);
7054 #if ENABLE_HUSH_MODE_X
7055 static void dump_cmd_in_x_mode(char **argv)
7057 if (G_x_mode && argv) {
7058 /* We want to output the line in one write op */
7066 len += strlen(argv[n++]) + 1;
7072 p += sprintf(p, " %s", argv[n++]);
7080 # define dump_cmd_in_x_mode(argv) ((void)0)
7084 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7085 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7086 #define pseudo_exec(nommu_save, command, argv_expanded) \
7087 pseudo_exec(command, argv_expanded)
7090 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7092 * Don't exit() here. If you don't exec, use _exit instead.
7093 * The at_exit handlers apparently confuse the calling process,
7094 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7096 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7097 char **argv, int assignment_cnt,
7098 char **argv_expanded) NORETURN;
7099 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7100 char **argv, int assignment_cnt,
7101 char **argv_expanded)
7105 new_env = expand_assignments(argv, assignment_cnt);
7106 dump_cmd_in_x_mode(new_env);
7108 if (!argv[assignment_cnt]) {
7109 /* Case when we are here: ... | var=val | ...
7110 * (note that we do not exit early, i.e., do not optimize out
7111 * expand_assignments(): think about ... | var=`sleep 1` | ...
7113 free_strings(new_env);
7114 _exit(EXIT_SUCCESS);
7118 set_vars_and_save_old(new_env);
7119 free(new_env); /* optional */
7120 /* we can also destroy set_vars_and_save_old's return value,
7123 nommu_save->new_env = new_env;
7124 nommu_save->old_vars = set_vars_and_save_old(new_env);
7127 if (argv_expanded) {
7128 argv = argv_expanded;
7130 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7132 nommu_save->argv = argv;
7135 dump_cmd_in_x_mode(argv);
7137 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7138 if (strchr(argv[0], '/') != NULL)
7142 /* Check if the command matches any of the builtins.
7143 * Depending on context, this might be redundant. But it's
7144 * easier to waste a few CPU cycles than it is to figure out
7145 * if this is one of those cases.
7148 /* On NOMMU, it is more expensive to re-execute shell
7149 * just in order to run echo or test builtin.
7150 * It's better to skip it here and run corresponding
7151 * non-builtin later. */
7152 const struct built_in_command *x;
7153 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7155 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7158 #if ENABLE_HUSH_FUNCTIONS
7159 /* Check if the command matches any functions */
7161 const struct function *funcp = find_function(argv[0]);
7163 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7168 #if ENABLE_FEATURE_SH_STANDALONE
7169 /* Check if the command matches any busybox applets */
7171 int a = find_applet_by_name(argv[0]);
7173 # if BB_MMU /* see above why on NOMMU it is not allowed */
7174 if (APPLET_IS_NOEXEC(a)) {
7175 /* Do not leak open fds from opened script files etc */
7176 close_all_FILE_list();
7177 debug_printf_exec("running applet '%s'\n", argv[0]);
7178 run_applet_no_and_exit(a, argv[0], argv);
7181 /* Re-exec ourselves */
7182 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7183 /* Don't propagate SIG_IGN to the child */
7184 if (SPECIAL_JOBSTOP_SIGS != 0)
7185 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7186 execv(bb_busybox_exec_path, argv);
7187 /* If they called chroot or otherwise made the binary no longer
7188 * executable, fall through */
7193 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7196 execvp_or_die(argv);
7199 /* Called after [v]fork() in run_pipe
7201 static void pseudo_exec(nommu_save_t *nommu_save,
7202 struct command *command,
7203 char **argv_expanded) NORETURN;
7204 static void pseudo_exec(nommu_save_t *nommu_save,
7205 struct command *command,
7206 char **argv_expanded)
7208 if (command->argv) {
7209 pseudo_exec_argv(nommu_save, command->argv,
7210 command->assignment_cnt, argv_expanded);
7213 if (command->group) {
7214 /* Cases when we are here:
7217 * ... | ( list ) | ...
7218 * ... | { list } | ...
7222 debug_printf_exec("pseudo_exec: run_list\n");
7223 reset_traps_to_defaults();
7224 rcode = run_list(command->group);
7225 /* OK to leak memory by not calling free_pipe_list,
7226 * since this process is about to exit */
7229 re_execute_shell(&nommu_save->argv_from_re_execing,
7230 command->group_as_string,
7237 /* Case when we are here: ... | >file */
7238 debug_printf_exec("pseudo_exec'ed null command\n");
7239 _exit(EXIT_SUCCESS);
7243 static const char *get_cmdtext(struct pipe *pi)
7249 /* This is subtle. ->cmdtext is created only on first backgrounding.
7250 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7251 * On subsequent bg argv is trashed, but we won't use it */
7255 argv = pi->cmds[0].argv;
7257 pi->cmdtext = xzalloc(1);
7262 len += strlen(*argv) + 1;
7266 argv = pi->cmds[0].argv;
7268 p = stpcpy(p, *argv);
7275 static void remove_job_from_table(struct pipe *pi)
7277 struct pipe *prev_pipe;
7279 if (pi == G.job_list) {
7280 G.job_list = pi->next;
7282 prev_pipe = G.job_list;
7283 while (prev_pipe->next != pi)
7284 prev_pipe = prev_pipe->next;
7285 prev_pipe->next = pi->next;
7289 G.last_jobid = G.job_list->jobid;
7292 static void delete_finished_job(struct pipe *pi)
7294 remove_job_from_table(pi);
7298 static void clean_up_last_dead_job(void)
7300 if (G.job_list && !G.job_list->alive_cmds)
7301 delete_finished_job(G.job_list);
7304 static void insert_job_into_table(struct pipe *pi)
7306 struct pipe *job, **jobp;
7309 clean_up_last_dead_job();
7311 /* Find the end of the list, and find next job ID to use */
7314 while ((job = *jobp) != NULL) {
7321 /* Create a new job struct at the end */
7322 job = *jobp = xmemdup(pi, sizeof(*pi));
7324 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7325 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7326 for (i = 0; i < pi->num_cmds; i++) {
7327 job->cmds[i].pid = pi->cmds[i].pid;
7328 /* all other fields are not used and stay zero */
7330 job->cmdtext = xstrdup(get_cmdtext(pi));
7332 if (G_interactive_fd)
7333 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7334 G.last_jobid = job->jobid;
7338 static int job_exited_or_stopped(struct pipe *pi)
7342 if (pi->alive_cmds != pi->stopped_cmds)
7345 /* All processes in fg pipe have exited or stopped */
7349 rcode = pi->cmds[i].cmd_exitcode;
7350 /* usually last process gives overall exitstatus,
7351 * but with "set -o pipefail", last *failed* process does */
7352 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7355 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7359 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7366 dead = WIFEXITED(status) || WIFSIGNALED(status);
7369 if (WIFSTOPPED(status))
7370 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7371 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7372 if (WIFSIGNALED(status))
7373 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7374 childpid, WTERMSIG(status), WEXITSTATUS(status));
7375 if (WIFEXITED(status))
7376 debug_printf_jobs("pid %d exited, exitcode %d\n",
7377 childpid, WEXITSTATUS(status));
7379 /* Were we asked to wait for a fg pipe? */
7381 i = fg_pipe->num_cmds;
7386 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7387 if (fg_pipe->cmds[i].pid != childpid)
7391 fg_pipe->cmds[i].pid = 0;
7392 fg_pipe->alive_cmds--;
7393 ex = WEXITSTATUS(status);
7394 /* bash prints killer signal's name for *last*
7395 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7396 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7398 if (WIFSIGNALED(status)) {
7399 int sig = WTERMSIG(status);
7400 if (i == fg_pipe->num_cmds-1)
7401 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7402 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7403 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7404 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7405 * Maybe we need to use sig | 128? */
7408 fg_pipe->cmds[i].cmd_exitcode = ex;
7410 fg_pipe->stopped_cmds++;
7412 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7413 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7414 rcode = job_exited_or_stopped(fg_pipe);
7416 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7417 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7418 * and "killall -STOP cat" */
7419 if (G_interactive_fd) {
7421 if (fg_pipe->alive_cmds != 0)
7422 insert_job_into_table(fg_pipe);
7426 if (fg_pipe->alive_cmds == 0)
7429 /* There are still running processes in the fg_pipe */
7432 /* It wasn't in fg_pipe, look for process in bg pipes */
7436 /* We were asked to wait for bg or orphaned children */
7437 /* No need to remember exitcode in this case */
7438 for (pi = G.job_list; pi; pi = pi->next) {
7439 for (i = 0; i < pi->num_cmds; i++) {
7440 if (pi->cmds[i].pid == childpid)
7441 goto found_pi_and_prognum;
7444 /* Happens when shell is used as init process (init=/bin/sh) */
7445 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7446 return -1; /* this wasn't a process from fg_pipe */
7448 found_pi_and_prognum:
7451 int rcode = WEXITSTATUS(status);
7452 if (WIFSIGNALED(status))
7453 rcode = 128 + WTERMSIG(status);
7454 pi->cmds[i].cmd_exitcode = rcode;
7455 if (G.last_bg_pid == pi->cmds[i].pid)
7456 G.last_bg_pid_exitcode = rcode;
7457 pi->cmds[i].pid = 0;
7459 if (!pi->alive_cmds) {
7460 if (G_interactive_fd) {
7461 printf(JOB_STATUS_FORMAT, pi->jobid,
7462 "Done", pi->cmdtext);
7463 delete_finished_job(pi);
7466 * bash deletes finished jobs from job table only in interactive mode,
7467 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7468 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7469 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7470 * We only retain one "dead" job, if it's the single job on the list.
7471 * This covers most of real-world scenarios where this is useful.
7473 if (pi != G.job_list)
7474 delete_finished_job(pi);
7482 return -1; /* this wasn't a process from fg_pipe */
7485 /* Check to see if any processes have exited -- if they have,
7486 * figure out why and see if a job has completed.
7488 * If non-NULL fg_pipe: wait for its completion or stop.
7489 * Return its exitcode or zero if stopped.
7491 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7492 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7493 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7494 * or 0 if no children changed status.
7496 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7497 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7498 * or 0 if no children changed status.
7500 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7506 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7508 attributes = WUNTRACED;
7509 if (fg_pipe == NULL)
7510 attributes |= WNOHANG;
7513 #if ENABLE_HUSH_FAST
7514 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7515 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7516 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7517 /* There was neither fork nor SIGCHLD since last waitpid */
7518 /* Avoid doing waitpid syscall if possible */
7519 if (!G.we_have_children) {
7523 if (fg_pipe == NULL) { /* is WNOHANG set? */
7524 /* We have children, but they did not exit
7525 * or stop yet (we saw no SIGCHLD) */
7528 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7532 /* Do we do this right?
7533 * bash-3.00# sleep 20 | false
7535 * [3]+ Stopped sleep 20 | false
7536 * bash-3.00# echo $?
7537 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7538 * [hush 1.14.0: yes we do it right]
7542 #if ENABLE_HUSH_FAST
7544 i = G.count_SIGCHLD;
7546 childpid = waitpid(-1, &status, attributes);
7547 if (childpid <= 0) {
7548 if (childpid && errno != ECHILD)
7549 bb_perror_msg("waitpid");
7550 #if ENABLE_HUSH_FAST
7551 else { /* Until next SIGCHLD, waitpid's are useless */
7552 G.we_have_children = (childpid == 0);
7553 G.handled_SIGCHLD = i;
7554 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7557 /* ECHILD (no children), or 0 (no change in children status) */
7561 rcode = process_wait_result(fg_pipe, childpid, status);
7563 /* fg_pipe exited or stopped */
7566 if (childpid == waitfor_pid) {
7567 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7568 rcode = WEXITSTATUS(status);
7569 if (WIFSIGNALED(status))
7570 rcode = 128 + WTERMSIG(status);
7571 if (WIFSTOPPED(status))
7572 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7573 rcode = 128 + WSTOPSIG(status);
7575 break; /* "wait PID" called us, give it exitcode+1 */
7577 /* This wasn't one of our processes, or */
7578 /* fg_pipe still has running processes, do waitpid again */
7579 } /* while (waitpid succeeds)... */
7585 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7588 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7589 if (G_saved_tty_pgrp) {
7590 /* Job finished, move the shell to the foreground */
7591 p = getpgrp(); /* our process group id */
7592 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7593 tcsetpgrp(G_interactive_fd, p);
7599 /* Start all the jobs, but don't wait for anything to finish.
7602 * Return code is normally -1, when the caller has to wait for children
7603 * to finish to determine the exit status of the pipe. If the pipe
7604 * is a simple builtin command, however, the action is done by the
7605 * time run_pipe returns, and the exit code is provided as the
7608 * Returns -1 only if started some children. IOW: we have to
7609 * mask out retvals of builtins etc with 0xff!
7611 * The only case when we do not need to [v]fork is when the pipe
7612 * is single, non-backgrounded, non-subshell command. Examples:
7613 * cmd ; ... { list } ; ...
7614 * cmd && ... { list } && ...
7615 * cmd || ... { list } || ...
7616 * If it is, then we can run cmd as a builtin, NOFORK,
7617 * or (if SH_STANDALONE) an applet, and we can run the { list }
7618 * with run_list. If it isn't one of these, we fork and exec cmd.
7620 * Cases when we must fork:
7621 * non-single: cmd | cmd
7622 * backgrounded: cmd & { list } &
7623 * subshell: ( list ) [&]
7625 #if !ENABLE_HUSH_MODE_X
7626 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7627 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7629 static int redirect_and_varexp_helper(char ***new_env_p,
7630 struct variable **old_vars_p,
7631 struct command *command,
7632 struct squirrel **sqp,
7633 char **argv_expanded)
7635 /* setup_redirects acts on file descriptors, not FILEs.
7636 * This is perfect for work that comes after exec().
7637 * Is it really safe for inline use? Experimentally,
7638 * things seem to work. */
7639 int rcode = setup_redirects(command, sqp);
7641 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7642 *new_env_p = new_env;
7643 dump_cmd_in_x_mode(new_env);
7644 dump_cmd_in_x_mode(argv_expanded);
7646 *old_vars_p = set_vars_and_save_old(new_env);
7650 static NOINLINE int run_pipe(struct pipe *pi)
7652 static const char *const null_ptr = NULL;
7656 struct command *command;
7657 char **argv_expanded;
7659 struct squirrel *squirrel = NULL;
7662 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7665 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7666 * Result should be 3 lines: q w e, qwe, q w e
7668 G.ifs = get_local_var_value("IFS");
7672 IF_HUSH_JOB(pi->pgrp = -1;)
7673 pi->stopped_cmds = 0;
7674 command = &pi->cmds[0];
7675 argv_expanded = NULL;
7677 if (pi->num_cmds != 1
7678 || pi->followup == PIPE_BG
7679 || command->cmd_type == CMD_SUBSHELL
7686 debug_printf_exec(": group:%p argv:'%s'\n",
7687 command->group, command->argv ? command->argv[0] : "NONE");
7689 if (command->group) {
7690 #if ENABLE_HUSH_FUNCTIONS
7691 if (command->cmd_type == CMD_FUNCDEF) {
7692 /* "executing" func () { list } */
7693 struct function *funcp;
7695 funcp = new_function(command->argv[0]);
7696 /* funcp->name is already set to argv[0] */
7697 funcp->body = command->group;
7699 funcp->body_as_string = command->group_as_string;
7700 command->group_as_string = NULL;
7702 command->group = NULL;
7703 command->argv[0] = NULL;
7704 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7705 funcp->parent_cmd = command;
7706 command->child_func = funcp;
7708 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7710 return EXIT_SUCCESS;
7714 debug_printf("non-subshell group\n");
7715 rcode = 1; /* exitcode if redir failed */
7716 if (setup_redirects(command, &squirrel) == 0) {
7717 debug_printf_exec(": run_list\n");
7718 rcode = run_list(command->group) & 0xff;
7720 restore_redirects(squirrel);
7721 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7723 debug_printf_exec("run_pipe: return %d\n", rcode);
7727 argv = command->argv ? command->argv : (char **) &null_ptr;
7729 const struct built_in_command *x;
7730 #if ENABLE_HUSH_FUNCTIONS
7731 const struct function *funcp;
7735 char **new_env = NULL;
7736 struct variable *old_vars = NULL;
7738 if (argv[command->assignment_cnt] == NULL) {
7739 /* Assignments, but no command */
7740 /* Ensure redirects take effect (that is, create files).
7741 * Try "a=t >file" */
7742 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7743 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7744 /* Set shell variables */
7748 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7749 /* Do we need to flag set_local_var() errors?
7750 * "assignment to readonly var" and "putenv error"
7755 /* Redirect error sets $? to 1. Otherwise,
7756 * if evaluating assignment value set $?, retain it.
7757 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7759 rcode = G.last_exitcode;
7760 /* Exit, _skipping_ variable restoring code: */
7761 goto clean_up_and_ret0;
7763 #else /* Older, bigger, but more correct code */
7765 rcode = setup_redirects(command, &squirrel);
7766 restore_redirects(squirrel);
7767 /* Set shell variables */
7769 bb_putchar_stderr('+');
7771 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7773 fprintf(stderr, " %s", p);
7774 debug_printf_exec("set shell var:'%s'->'%s'\n",
7776 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7777 /* Do we need to flag set_local_var() errors?
7778 * "assignment to readonly var" and "putenv error"
7783 bb_putchar_stderr('\n');
7784 /* Redirect error sets $? to 1. Otherwise,
7785 * if evaluating assignment value set $?, retain it.
7786 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7788 rcode = G.last_exitcode;
7789 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7791 debug_printf_exec("run_pipe: return %d\n", rcode);
7796 /* Expand the rest into (possibly) many strings each */
7798 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7799 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7803 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7806 /* if someone gives us an empty string: `cmd with empty output` */
7807 if (!argv_expanded[0]) {
7808 free(argv_expanded);
7810 return G.last_exitcode;
7813 x = find_builtin(argv_expanded[0]);
7814 #if ENABLE_HUSH_FUNCTIONS
7817 funcp = find_function(argv_expanded[0]);
7821 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7822 debug_printf("exec with redirects only\n");
7823 rcode = setup_redirects(command, NULL);
7824 /* rcode=1 can be if redir file can't be opened */
7825 goto clean_up_and_ret1;
7828 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7831 debug_printf_exec(": builtin '%s' '%s'...\n",
7832 x->b_cmd, argv_expanded[1]);
7834 rcode = x->b_function(argv_expanded) & 0xff;
7837 #if ENABLE_HUSH_FUNCTIONS
7839 # if ENABLE_HUSH_LOCAL
7840 struct variable **sv;
7841 sv = G.shadowed_vars_pp;
7842 G.shadowed_vars_pp = &old_vars;
7844 debug_printf_exec(": function '%s' '%s'...\n",
7845 funcp->name, argv_expanded[1]);
7846 rcode = run_function(funcp, argv_expanded) & 0xff;
7847 # if ENABLE_HUSH_LOCAL
7848 G.shadowed_vars_pp = sv;
7854 unset_vars(new_env);
7856 /* clean_up_and_ret0: */
7857 restore_redirects(squirrel);
7859 free(argv_expanded);
7860 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7862 debug_printf_exec("run_pipe return %d\n", rcode);
7866 if (ENABLE_FEATURE_SH_NOFORK) {
7867 int n = find_applet_by_name(argv_expanded[0]);
7868 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7869 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7871 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7872 argv_expanded[0], argv_expanded[1]);
7873 rcode = run_nofork_applet(n, argv_expanded);
7875 goto clean_up_and_ret;
7878 /* It is neither builtin nor applet. We must fork. */
7882 /* NB: argv_expanded may already be created, and that
7883 * might include `cmd` runs! Do not rerun it! We *must*
7884 * use argv_expanded if it's non-NULL */
7886 /* Going to fork a child per each pipe member */
7891 while (cmd_no < pi->num_cmds) {
7892 struct fd_pair pipefds;
7894 volatile nommu_save_t nommu_save;
7895 nommu_save.new_env = NULL;
7896 nommu_save.old_vars = NULL;
7897 nommu_save.argv = NULL;
7898 nommu_save.argv_from_re_execing = NULL;
7900 command = &pi->cmds[cmd_no];
7902 if (command->argv) {
7903 debug_printf_exec(": pipe member '%s' '%s'...\n",
7904 command->argv[0], command->argv[1]);
7906 debug_printf_exec(": pipe member with no argv\n");
7909 /* pipes are inserted between pairs of commands */
7912 if (cmd_no < pi->num_cmds)
7913 xpiped_pair(pipefds);
7915 command->pid = BB_MMU ? fork() : vfork();
7916 if (!command->pid) { /* child */
7918 disable_restore_tty_pgrp_on_exit();
7919 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7921 /* Every child adds itself to new process group
7922 * with pgid == pid_of_first_child_in_pipe */
7923 if (G.run_list_level == 1 && G_interactive_fd) {
7926 if (pgrp < 0) /* true for 1st process only */
7928 if (setpgid(0, pgrp) == 0
7929 && pi->followup != PIPE_BG
7930 && G_saved_tty_pgrp /* we have ctty */
7932 /* We do it in *every* child, not just first,
7934 tcsetpgrp(G_interactive_fd, pgrp);
7938 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7939 /* 1st cmd in backgrounded pipe
7940 * should have its stdin /dev/null'ed */
7942 if (open(bb_dev_null, O_RDONLY))
7943 xopen("/", O_RDONLY);
7945 xmove_fd(next_infd, 0);
7947 xmove_fd(pipefds.wr, 1);
7950 /* Like bash, explicit redirects override pipes,
7951 * and the pipe fd (fd#1) is available for dup'ing:
7952 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7953 * of cmd1 goes into pipe.
7955 if (setup_redirects(command, NULL)) {
7956 /* Happens when redir file can't be opened:
7957 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7959 * hush: can't open '/qwe/rty': No such file or directory
7961 * (echo BAR is not executed, it hits _exit(1) below)
7966 /* Stores to nommu_save list of env vars putenv'ed
7967 * (NOMMU, on MMU we don't need that) */
7968 /* cast away volatility... */
7969 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7970 /* pseudo_exec() does not return */
7973 /* parent or error */
7974 #if ENABLE_HUSH_FAST
7976 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7978 enable_restore_tty_pgrp_on_exit();
7980 /* Clean up after vforked child */
7981 free(nommu_save.argv);
7982 free(nommu_save.argv_from_re_execing);
7983 unset_vars(nommu_save.new_env);
7984 add_vars(nommu_save.old_vars);
7986 free(argv_expanded);
7987 argv_expanded = NULL;
7988 if (command->pid < 0) { /* [v]fork failed */
7989 /* Clearly indicate, was it fork or vfork */
7990 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7994 /* Second and next children need to know pid of first one */
7996 pi->pgrp = command->pid;
8002 if (cmd_no < pi->num_cmds)
8004 /* Pass read (output) pipe end to next iteration */
8005 next_infd = pipefds.rd;
8008 if (!pi->alive_cmds) {
8010 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8015 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8019 /* NB: called by pseudo_exec, and therefore must not modify any
8020 * global data until exec/_exit (we can be a child after vfork!) */
8021 static int run_list(struct pipe *pi)
8023 #if ENABLE_HUSH_CASE
8024 char *case_word = NULL;
8026 #if ENABLE_HUSH_LOOPS
8027 struct pipe *loop_top = NULL;
8028 char **for_lcur = NULL;
8029 char **for_list = NULL;
8031 smallint last_followup;
8033 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8034 smalluint cond_code = 0;
8036 enum { cond_code = 0 };
8039 smallint rword; /* RES_foo */
8040 smallint last_rword; /* ditto */
8043 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8046 #if ENABLE_HUSH_LOOPS
8047 /* Check syntax for "for" */
8050 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8051 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8053 /* current word is FOR or IN (BOLD in comments below) */
8054 if (cpipe->next == NULL) {
8055 syntax_error("malformed for");
8057 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8060 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8061 if (cpipe->next->res_word == RES_DO)
8063 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8064 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8065 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8067 syntax_error("malformed for");
8069 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8076 /* Past this point, all code paths should jump to ret: label
8077 * in order to return, no direct "return" statements please.
8078 * This helps to ensure that no memory is leaked. */
8086 last_rword = RES_XXXX;
8088 last_followup = PIPE_SEQ;
8089 rcode = G.last_exitcode;
8091 /* Go through list of pipes, (maybe) executing them. */
8092 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8094 int sv_errexit_depth;
8098 if (G_flag_return_in_progress == 1)
8101 IF_HAS_KEYWORDS(rword = pi->res_word;)
8102 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8103 rword, cond_code, last_rword);
8105 sv_errexit_depth = G.errexit_depth;
8106 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8107 pi->followup != PIPE_SEQ
8111 #if ENABLE_HUSH_LOOPS
8112 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8113 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8115 /* start of a loop: remember where loop starts */
8120 /* Still in the same "if...", "then..." or "do..." branch? */
8121 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8122 if ((rcode == 0 && last_followup == PIPE_OR)
8123 || (rcode != 0 && last_followup == PIPE_AND)
8125 /* It is "<true> || CMD" or "<false> && CMD"
8126 * and we should not execute CMD */
8127 debug_printf_exec("skipped cmd because of || or &&\n");
8128 last_followup = pi->followup;
8129 goto dont_check_jobs_but_continue;
8132 last_followup = pi->followup;
8133 IF_HAS_KEYWORDS(last_rword = rword;)
8136 if (rword == RES_THEN) {
8137 /* if false; then ... fi has exitcode 0! */
8138 G.last_exitcode = rcode = EXIT_SUCCESS;
8139 /* "if <false> THEN cmd": skip cmd */
8143 if (rword == RES_ELSE || rword == RES_ELIF) {
8144 /* "if <true> then ... ELSE/ELIF cmd":
8145 * skip cmd and all following ones */
8150 #if ENABLE_HUSH_LOOPS
8151 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8153 /* first loop through for */
8155 static const char encoded_dollar_at[] ALIGN1 = {
8156 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8157 }; /* encoded representation of "$@" */
8158 static const char *const encoded_dollar_at_argv[] = {
8159 encoded_dollar_at, NULL
8160 }; /* argv list with one element: "$@" */
8163 vals = (char**)encoded_dollar_at_argv;
8164 if (pi->next->res_word == RES_IN) {
8165 /* if no variable values after "in" we skip "for" */
8166 if (!pi->next->cmds[0].argv) {
8167 G.last_exitcode = rcode = EXIT_SUCCESS;
8168 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8171 vals = pi->next->cmds[0].argv;
8172 } /* else: "for var; do..." -> assume "$@" list */
8173 /* create list of variable values */
8174 debug_print_strings("for_list made from", vals);
8175 for_list = expand_strvec_to_strvec(vals);
8176 for_lcur = for_list;
8177 debug_print_strings("for_list", for_list);
8180 /* "for" loop is over, clean up */
8186 /* Insert next value from for_lcur */
8187 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8188 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8191 if (rword == RES_IN) {
8192 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8194 if (rword == RES_DONE) {
8195 continue; /* "done" has no cmds too */
8198 #if ENABLE_HUSH_CASE
8199 if (rword == RES_CASE) {
8200 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8201 case_word = expand_strvec_to_string(pi->cmds->argv);
8202 unbackslash(case_word);
8205 if (rword == RES_MATCH) {
8208 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8209 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8211 /* all prev words didn't match, does this one match? */
8212 argv = pi->cmds->argv;
8214 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8215 /* TODO: which FNM_xxx flags to use? */
8216 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8217 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8219 if (cond_code == 0) { /* match! we will execute this branch */
8221 case_word = NULL; /* make future "word)" stop */
8228 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8229 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8231 continue; /* not matched yet, skip this pipe */
8233 if (rword == RES_ESAC) {
8234 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8236 /* "case" did not match anything: still set $? (to 0) */
8237 G.last_exitcode = rcode = EXIT_SUCCESS;
8241 /* Just pressing <enter> in shell should check for jobs.
8242 * OTOH, in non-interactive shell this is useless
8243 * and only leads to extra job checks */
8244 if (pi->num_cmds == 0) {
8245 if (G_interactive_fd)
8246 goto check_jobs_and_continue;
8250 /* After analyzing all keywords and conditions, we decided
8251 * to execute this pipe. NB: have to do checkjobs(NULL)
8252 * after run_pipe to collect any background children,
8253 * even if list execution is to be stopped. */
8254 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8255 #if ENABLE_HUSH_LOOPS
8256 G.flag_break_continue = 0;
8258 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8260 /* We ran a builtin, function, or group.
8261 * rcode is already known
8262 * and we don't need to wait for anything. */
8263 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8264 G.last_exitcode = rcode;
8265 check_and_run_traps();
8266 #if ENABLE_HUSH_LOOPS
8267 /* Was it "break" or "continue"? */
8268 if (G.flag_break_continue) {
8269 smallint fbc = G.flag_break_continue;
8270 /* We might fall into outer *loop*,
8271 * don't want to break it too */
8273 G.depth_break_continue--;
8274 if (G.depth_break_continue == 0)
8275 G.flag_break_continue = 0;
8276 /* else: e.g. "continue 2" should *break* once, *then* continue */
8277 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8278 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8279 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8282 /* "continue": simulate end of loop */
8287 if (G_flag_return_in_progress == 1) {
8288 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8291 } else if (pi->followup == PIPE_BG) {
8292 /* What does bash do with attempts to background builtins? */
8293 /* even bash 3.2 doesn't do that well with nested bg:
8294 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8295 * I'm NOT treating inner &'s as jobs */
8297 if (G.run_list_level == 1)
8298 insert_job_into_table(pi);
8300 /* Last command's pid goes to $! */
8301 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8302 G.last_bg_pid_exitcode = 0;
8303 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8304 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8305 rcode = EXIT_SUCCESS;
8309 if (G.run_list_level == 1 && G_interactive_fd) {
8310 /* Waits for completion, then fg's main shell */
8311 rcode = checkjobs_and_fg_shell(pi);
8312 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8316 /* This one just waits for completion */
8317 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8318 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8320 G.last_exitcode = rcode;
8321 check_and_run_traps();
8324 /* Handle "set -e" */
8325 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8326 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8327 if (G.errexit_depth == 0)
8330 G.errexit_depth = sv_errexit_depth;
8332 /* Analyze how result affects subsequent commands */
8334 if (rword == RES_IF || rword == RES_ELIF)
8337 check_jobs_and_continue:
8338 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8339 dont_check_jobs_but_continue: ;
8340 #if ENABLE_HUSH_LOOPS
8341 /* Beware of "while false; true; do ..."! */
8343 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8344 /* check for RES_DONE is needed for "while ...; do \n done" case */
8346 if (rword == RES_WHILE) {
8348 /* "while false; do...done" - exitcode 0 */
8349 G.last_exitcode = rcode = EXIT_SUCCESS;
8350 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8354 if (rword == RES_UNTIL) {
8356 debug_printf_exec(": until expr is true: breaking\n");
8367 #if ENABLE_HUSH_LOOPS
8372 #if ENABLE_HUSH_CASE
8376 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8380 /* Select which version we will use */
8381 static int run_and_free_list(struct pipe *pi)
8384 debug_printf_exec("run_and_free_list entered\n");
8385 if (!G.o_opt[OPT_O_NOEXEC]) {
8386 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8387 rcode = run_list(pi);
8389 /* free_pipe_list has the side effect of clearing memory.
8390 * In the long run that function can be merged with run_list,
8391 * but doing that now would hobble the debugging effort. */
8393 debug_printf_exec("run_and_free_list return %d\n", rcode);
8398 static void install_sighandlers(unsigned mask)
8400 sighandler_t old_handler;
8402 while ((mask >>= 1) != 0) {
8406 old_handler = install_sighandler(sig, pick_sighandler(sig));
8407 /* POSIX allows shell to re-enable SIGCHLD
8408 * even if it was SIG_IGN on entry.
8409 * Therefore we skip IGN check for it:
8413 if (old_handler == SIG_IGN) {
8414 /* oops... restore back to IGN, and record this fact */
8415 install_sighandler(sig, old_handler);
8416 #if ENABLE_HUSH_TRAP
8418 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8420 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8426 /* Called a few times only (or even once if "sh -c") */
8427 static void install_special_sighandlers(void)
8431 /* Which signals are shell-special? */
8432 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8433 if (G_interactive_fd) {
8434 mask |= SPECIAL_INTERACTIVE_SIGS;
8435 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8436 mask |= SPECIAL_JOBSTOP_SIGS;
8438 /* Careful, do not re-install handlers we already installed */
8439 if (G.special_sig_mask != mask) {
8440 unsigned diff = mask & ~G.special_sig_mask;
8441 G.special_sig_mask = mask;
8442 install_sighandlers(diff);
8448 /* Set handlers to restore tty pgrp and exit */
8449 static void install_fatal_sighandlers(void)
8453 /* We will restore tty pgrp on these signals */
8455 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8456 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8457 + (1 << SIGBUS ) * HUSH_DEBUG
8458 + (1 << SIGSEGV) * HUSH_DEBUG
8459 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8461 /* bash 3.2 seems to handle these just like 'fatal' ones */
8464 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8465 * if we aren't interactive... but in this case
8466 * we never want to restore pgrp on exit, and this fn is not called
8468 /*+ (1 << SIGHUP )*/
8469 /*+ (1 << SIGTERM)*/
8470 /*+ (1 << SIGINT )*/
8472 G_fatal_sig_mask = mask;
8474 install_sighandlers(mask);
8478 static int set_mode(int state, char mode, const char *o_opt)
8483 G.o_opt[OPT_O_NOEXEC] = state;
8486 IF_HUSH_MODE_X(G_x_mode = state;)
8490 /* "set -+o" without parameter.
8491 * in bash, set -o produces this output:
8495 * We always use the second form.
8497 const char *p = o_opt_strings;
8500 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8506 idx = index_in_strings(o_opt_strings, o_opt);
8508 G.o_opt[idx] = state;
8512 G.o_opt[OPT_O_ERREXIT] = state;
8515 return EXIT_FAILURE;
8517 return EXIT_SUCCESS;
8520 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8521 int hush_main(int argc, char **argv)
8524 OPT_login = (1 << 0),
8528 unsigned builtin_argc;
8530 struct variable *cur_var;
8531 struct variable *shell_ver;
8534 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8535 G.last_exitcode = EXIT_SUCCESS;
8537 #if ENABLE_HUSH_FAST
8538 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8541 G.argv0_for_re_execing = argv[0];
8543 /* Deal with HUSH_VERSION */
8544 shell_ver = xzalloc(sizeof(*shell_ver));
8545 shell_ver->flg_export = 1;
8546 shell_ver->flg_read_only = 1;
8547 /* Code which handles ${var<op>...} needs writable values for all variables,
8548 * therefore we xstrdup: */
8549 shell_ver->varstr = xstrdup(hush_version_str);
8550 /* Create shell local variables from the values
8551 * currently living in the environment */
8552 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8553 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8554 G.top_var = shell_ver;
8555 cur_var = G.top_var;
8558 char *value = strchr(*e, '=');
8559 if (value) { /* paranoia */
8560 cur_var->next = xzalloc(sizeof(*cur_var));
8561 cur_var = cur_var->next;
8562 cur_var->varstr = *e;
8563 cur_var->max_len = strlen(*e);
8564 cur_var->flg_export = 1;
8568 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8569 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8570 putenv(shell_ver->varstr);
8573 set_pwd_var(/*exp:*/ 1);
8575 #if BASH_HOSTNAME_VAR
8576 /* Set (but not export) HOSTNAME unless already set */
8577 if (!get_local_var_value("HOSTNAME")) {
8580 set_local_var_from_halves("HOSTNAME", uts.nodename);
8582 /* bash also exports SHLVL and _,
8583 * and sets (but doesn't export) the following variables:
8585 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8586 * BASH_VERSION='3.2.0(1)-release'
8588 * MACHTYPE=i386-pc-linux-gnu
8590 * PPID=<NNNNN> - we also do it elsewhere
8601 * PIPESTATUS=([0]="0")
8602 * HISTFILE=/<xxx>/.bash_history
8606 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8608 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8619 #if ENABLE_FEATURE_EDITING
8620 G.line_input_state = new_line_input_t(FOR_SHELL);
8623 /* Initialize some more globals to non-zero values */
8624 cmdedit_update_prompt();
8626 die_func = restore_ttypgrp_and__exit;
8628 /* Shell is non-interactive at first. We need to call
8629 * install_special_sighandlers() if we are going to execute "sh <script>",
8630 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8631 * If we later decide that we are interactive, we run install_special_sighandlers()
8632 * in order to intercept (more) signals.
8636 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8637 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8640 opt = getopt(argc, argv, "+c:exinsl"
8643 # if ENABLE_HUSH_FUNCTIONS
8653 * sh ... -c 'script'
8654 * sh ... -c 'script' ARG0 [ARG1...]
8655 * On NOMMU, if builtin_argc != 0,
8656 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8657 * "" needs to be replaced with NULL
8658 * and BARGV vector fed to builtin function.
8659 * Note: the form without ARG0 never happens:
8660 * sh ... -c 'builtin' BARGV... ""
8663 G.root_pid = getpid();
8664 G.root_ppid = getppid();
8666 G.global_argv = argv + optind;
8667 G.global_argc = argc - optind;
8669 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8670 const struct built_in_command *x;
8672 install_special_sighandlers();
8673 x = find_builtin(optarg);
8674 if (x) { /* paranoia */
8675 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8676 G.global_argv += builtin_argc;
8677 G.global_argv[-1] = NULL; /* replace "" */
8679 G.last_exitcode = x->b_function(argv + optind - 1);
8683 if (!G.global_argv[0]) {
8684 /* -c 'script' (no params): prevent empty $0 */
8685 G.global_argv--; /* points to argv[i] of 'script' */
8686 G.global_argv[0] = argv[0];
8688 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8689 install_special_sighandlers();
8690 parse_and_run_string(optarg);
8693 /* Well, we cannot just declare interactiveness,
8694 * we have to have some stuff (ctty, etc) */
8695 /* G_interactive_fd++; */
8698 /* "-s" means "read from stdin", but this is how we always
8699 * operate, so simply do nothing here. */
8705 case '<': /* "big heredoc" support */
8706 full_write1_str(optarg);
8709 unsigned long long empty_trap_mask;
8711 G.root_pid = bb_strtou(optarg, &optarg, 16);
8713 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8715 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8717 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8719 builtin_argc = bb_strtou(optarg, &optarg, 16);
8721 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8722 if (empty_trap_mask != 0) {
8723 IF_HUSH_TRAP(int sig;)
8724 install_special_sighandlers();
8725 # if ENABLE_HUSH_TRAP
8726 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8727 for (sig = 1; sig < NSIG; sig++) {
8728 if (empty_trap_mask & (1LL << sig)) {
8729 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8730 install_sighandler(sig, SIG_IGN);
8735 # if ENABLE_HUSH_LOOPS
8737 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8743 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8745 # if ENABLE_HUSH_FUNCTIONS
8747 struct function *funcp = new_function(optarg);
8748 /* funcp->name is already set to optarg */
8749 /* funcp->body is set to NULL. It's a special case. */
8750 funcp->body_as_string = argv[optind];
8759 if (set_mode(1, opt, NULL) == 0) /* no error */
8763 fprintf(stderr, "Usage: sh [FILE]...\n"
8764 " or: sh -c command [args]...\n\n");
8770 } /* option parsing loop */
8772 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8773 G.global_argc = argc - (optind - 1);
8774 G.global_argv = argv + (optind - 1);
8775 G.global_argv[0] = argv[0];
8778 G.root_pid = getpid();
8779 G.root_ppid = getppid();
8782 /* If we are login shell... */
8783 if (flags & OPT_login) {
8785 debug_printf("sourcing /etc/profile\n");
8786 input = fopen_for_read("/etc/profile");
8787 if (input != NULL) {
8788 remember_FILE(input);
8789 install_special_sighandlers();
8790 parse_and_run_file(input);
8791 fclose_and_forget(input);
8793 /* bash: after sourcing /etc/profile,
8794 * tries to source (in the given order):
8795 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8796 * stopping on first found. --noprofile turns this off.
8797 * bash also sources ~/.bash_logout on exit.
8798 * If called as sh, skips .bash_XXX files.
8802 if (G.global_argv[1]) {
8805 * "bash <script>" (which is never interactive (unless -i?))
8806 * sources $BASH_ENV here (without scanning $PATH).
8807 * If called as sh, does the same but with $ENV.
8808 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8812 debug_printf("running script '%s'\n", G.global_argv[0]);
8813 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8814 input = xfopen_for_read(G.global_argv[0]);
8815 xfunc_error_retval = 1;
8816 remember_FILE(input);
8817 install_special_sighandlers();
8818 parse_and_run_file(input);
8819 #if ENABLE_FEATURE_CLEAN_UP
8820 fclose_and_forget(input);
8825 /* Up to here, shell was non-interactive. Now it may become one.
8826 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8829 /* A shell is interactive if the '-i' flag was given,
8830 * or if all of the following conditions are met:
8832 * no arguments remaining or the -s flag given
8833 * standard input is a terminal
8834 * standard output is a terminal
8835 * Refer to Posix.2, the description of the 'sh' utility.
8838 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8839 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8840 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8841 if (G_saved_tty_pgrp < 0)
8842 G_saved_tty_pgrp = 0;
8844 /* try to dup stdin to high fd#, >= 255 */
8845 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8846 if (G_interactive_fd < 0) {
8847 /* try to dup to any fd */
8848 G_interactive_fd = dup(STDIN_FILENO);
8849 if (G_interactive_fd < 0) {
8851 G_interactive_fd = 0;
8852 G_saved_tty_pgrp = 0;
8855 // TODO: track & disallow any attempts of user
8856 // to (inadvertently) close/redirect G_interactive_fd
8858 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8859 if (G_interactive_fd) {
8860 close_on_exec_on(G_interactive_fd);
8862 if (G_saved_tty_pgrp) {
8863 /* If we were run as 'hush &', sleep until we are
8864 * in the foreground (tty pgrp == our pgrp).
8865 * If we get started under a job aware app (like bash),
8866 * make sure we are now in charge so we don't fight over
8867 * who gets the foreground */
8869 pid_t shell_pgrp = getpgrp();
8870 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8871 if (G_saved_tty_pgrp == shell_pgrp)
8873 /* send TTIN to ourself (should stop us) */
8874 kill(- shell_pgrp, SIGTTIN);
8878 /* Install more signal handlers */
8879 install_special_sighandlers();
8881 if (G_saved_tty_pgrp) {
8882 /* Set other signals to restore saved_tty_pgrp */
8883 install_fatal_sighandlers();
8884 /* Put ourselves in our own process group
8885 * (bash, too, does this only if ctty is available) */
8886 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8887 /* Grab control of the terminal */
8888 tcsetpgrp(G_interactive_fd, getpid());
8890 enable_restore_tty_pgrp_on_exit();
8892 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8894 const char *hp = get_local_var_value("HISTFILE");
8896 hp = get_local_var_value("HOME");
8898 hp = concat_path_file(hp, ".hush_history");
8903 G.line_input_state->hist_file = hp;
8904 //set_local_var(xasprintf("HISTFILE=%s", ...));
8906 # if ENABLE_FEATURE_SH_HISTFILESIZE
8907 hp = get_local_var_value("HISTFILESIZE");
8908 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8913 install_special_sighandlers();
8915 #elif ENABLE_HUSH_INTERACTIVE
8916 /* No job control compiled in, only prompt/line editing */
8917 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8918 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8919 if (G_interactive_fd < 0) {
8920 /* try to dup to any fd */
8921 G_interactive_fd = dup(STDIN_FILENO);
8922 if (G_interactive_fd < 0)
8924 G_interactive_fd = 0;
8927 if (G_interactive_fd) {
8928 close_on_exec_on(G_interactive_fd);
8930 install_special_sighandlers();
8932 /* We have interactiveness code disabled */
8933 install_special_sighandlers();
8936 * if interactive but not a login shell, sources ~/.bashrc
8937 * (--norc turns this off, --rcfile <file> overrides)
8940 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8941 /* note: ash and hush share this string */
8942 printf("\n\n%s %s\n"
8943 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8946 "hush - the humble shell"
8950 parse_and_run_file(stdin);
8953 hush_exit(G.last_exitcode);
8960 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8965 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8966 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8968 int argc = string_array_len(argv);
8969 return applet_main_func(argc, argv);
8972 #if ENABLE_HUSH_TEST || BASH_TEST2
8973 static int FAST_FUNC builtin_test(char **argv)
8975 return run_applet_main(argv, test_main);
8978 #if ENABLE_HUSH_ECHO
8979 static int FAST_FUNC builtin_echo(char **argv)
8981 return run_applet_main(argv, echo_main);
8984 #if ENABLE_HUSH_PRINTF
8985 static int FAST_FUNC builtin_printf(char **argv)
8987 return run_applet_main(argv, printf_main);
8991 #if ENABLE_HUSH_HELP
8992 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8994 const struct built_in_command *x;
8997 "Built-in commands:\n"
8998 "------------------\n");
8999 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9001 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9003 return EXIT_SUCCESS;
9007 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9008 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9010 show_history(G.line_input_state);
9011 return EXIT_SUCCESS;
9015 static char **skip_dash_dash(char **argv)
9018 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9023 static int FAST_FUNC builtin_cd(char **argv)
9027 argv = skip_dash_dash(argv);
9029 if (newdir == NULL) {
9030 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9031 * bash says "bash: cd: HOME not set" and does nothing
9034 const char *home = get_local_var_value("HOME");
9035 newdir = home ? home : "/";
9037 if (chdir(newdir)) {
9038 /* Mimic bash message exactly */
9039 bb_perror_msg("cd: %s", newdir);
9040 return EXIT_FAILURE;
9042 /* Read current dir (get_cwd(1) is inside) and set PWD.
9043 * Note: do not enforce exporting. If PWD was unset or unexported,
9044 * set it again, but do not export. bash does the same.
9046 set_pwd_var(/*exp:*/ 0);
9047 return EXIT_SUCCESS;
9050 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9053 return EXIT_SUCCESS;
9056 static int FAST_FUNC builtin_eval(char **argv)
9058 int rcode = EXIT_SUCCESS;
9060 argv = skip_dash_dash(argv);
9062 char *str = expand_strvec_to_string(argv);
9064 * eval "echo Hi; done" ("done" is syntax error):
9065 * "echo Hi" will not execute too.
9067 parse_and_run_string(str);
9069 rcode = G.last_exitcode;
9074 static int FAST_FUNC builtin_exec(char **argv)
9076 argv = skip_dash_dash(argv);
9077 if (argv[0] == NULL)
9078 return EXIT_SUCCESS; /* bash does this */
9080 /* Careful: we can end up here after [v]fork. Do not restore
9081 * tty pgrp then, only top-level shell process does that */
9082 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9083 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9085 /* TODO: if exec fails, bash does NOT exit! We do.
9086 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9087 * and tcsetpgrp, and this is inherently racy.
9089 execvp_or_die(argv);
9092 static int FAST_FUNC builtin_exit(char **argv)
9094 debug_printf_exec("%s()\n", __func__);
9096 /* interactive bash:
9097 * # trap "echo EEE" EXIT
9100 * There are stopped jobs.
9101 * (if there are _stopped_ jobs, running ones don't count)
9104 * EEE (then bash exits)
9106 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9109 /* note: EXIT trap is run by hush_exit */
9110 argv = skip_dash_dash(argv);
9111 if (argv[0] == NULL)
9112 hush_exit(G.last_exitcode);
9113 /* mimic bash: exit 123abc == exit 255 + error msg */
9114 xfunc_error_retval = 255;
9115 /* bash: exit -2 == exit 254, no error msg */
9116 hush_exit(xatoi(argv[0]) & 0xff);
9119 #if ENABLE_HUSH_TYPE
9120 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9121 static int FAST_FUNC builtin_type(char **argv)
9123 int ret = EXIT_SUCCESS;
9129 if (0) {} /* make conditional compile easier below */
9130 /*else if (find_alias(*argv))
9131 type = "an alias";*/
9132 #if ENABLE_HUSH_FUNCTIONS
9133 else if (find_function(*argv))
9134 type = "a function";
9136 else if (find_builtin(*argv))
9137 type = "a shell builtin";
9138 else if ((path = find_in_path(*argv)) != NULL)
9141 bb_error_msg("type: %s: not found", *argv);
9146 printf("%s is %s\n", *argv, type);
9154 #if ENABLE_HUSH_READ
9155 /* Interruptibility of read builtin in bash
9156 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9158 * Empty trap makes read ignore corresponding signal, for any signal.
9161 * - terminates non-interactive shell;
9162 * - interrupts read in interactive shell;
9163 * if it has non-empty trap:
9164 * - executes trap and returns to command prompt in interactive shell;
9165 * - executes trap and returns to read in non-interactive shell;
9167 * - is ignored (does not interrupt) read in interactive shell;
9168 * - terminates non-interactive shell;
9169 * if it has non-empty trap:
9170 * - executes trap and returns to read;
9172 * - terminates shell (regardless of interactivity);
9173 * if it has non-empty trap:
9174 * - executes trap and returns to read;
9175 * SIGCHLD from children:
9176 * - does not interrupt read regardless of interactivity:
9177 * try: sleep 1 & read x; echo $x
9179 static int FAST_FUNC builtin_read(char **argv)
9189 /* "!": do not abort on errors.
9190 * Option string must start with "sr" to match BUILTIN_READ_xxx
9192 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9193 if (read_flags == (uint32_t)-1)
9194 return EXIT_FAILURE;
9196 ifs = get_local_var_value("IFS"); /* can be NULL */
9199 r = shell_builtin_read(set_local_var_from_halves,
9209 if ((uintptr_t)r == 1 && errno == EINTR) {
9210 unsigned sig = check_and_run_traps();
9215 if ((uintptr_t)r > 1) {
9216 bb_error_msg("%s", r);
9217 r = (char*)(uintptr_t)1;
9220 return (uintptr_t)r;
9224 #if ENABLE_HUSH_UMASK
9225 static int FAST_FUNC builtin_umask(char **argv)
9232 argv = skip_dash_dash(argv);
9234 mode_t old_mask = mask;
9236 /* numeric umasks are taken as-is */
9237 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9238 if (!isdigit(argv[0][0]))
9240 mask = bb_parse_mode(argv[0], mask);
9241 if (!isdigit(argv[0][0]))
9243 if ((unsigned)mask > 0777) {
9246 * bash: umask: 'q': invalid symbolic mode operator
9247 * bash: umask: 999: octal number out of range
9249 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9254 printf("%04o\n", (unsigned) mask);
9255 /* fall through and restore mask which we set to 0 */
9259 return !rc; /* rc != 0 - success */
9263 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9264 static void print_escaped(const char *s)
9269 const char *p = strchrnul(s, '\'');
9270 /* print 'xxxx', possibly just '' */
9271 printf("'%.*s'", (int)(p - s), s);
9276 /* s points to '; print "'''...'''" */
9278 do putchar('\''); while (*++s == '\'');
9284 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9285 # if !ENABLE_HUSH_LOCAL
9286 #define helper_export_local(argv, exp, lvl) \
9287 helper_export_local(argv, exp)
9289 static void helper_export_local(char **argv, int exp, int lvl)
9293 char *name_end = strchrnul(name, '=');
9295 /* So far we do not check that name is valid (TODO?) */
9297 if (*name_end == '\0') {
9298 struct variable *var, **vpp;
9300 vpp = get_ptr_to_local_var(name, name_end - name);
9301 var = vpp ? *vpp : NULL;
9303 if (exp == -1) { /* unexporting? */
9304 /* export -n NAME (without =VALUE) */
9306 var->flg_export = 0;
9307 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9309 } /* else: export -n NOT_EXISTING_VAR: no-op */
9312 if (exp == 1) { /* exporting? */
9313 /* export NAME (without =VALUE) */
9315 var->flg_export = 1;
9316 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9317 putenv(var->varstr);
9321 # if ENABLE_HUSH_LOCAL
9322 if (exp == 0 /* local? */
9323 && var && var->func_nest_level == lvl
9325 /* "local x=abc; ...; local x" - ignore second local decl */
9329 /* Exporting non-existing variable.
9330 * bash does not put it in environment,
9331 * but remembers that it is exported,
9332 * and does put it in env when it is set later.
9333 * We just set it to "" and export. */
9334 /* Or, it's "local NAME" (without =VALUE).
9335 * bash sets the value to "". */
9336 name = xasprintf("%s=", name);
9338 /* (Un)exporting/making local NAME=VALUE */
9339 name = xstrdup(name);
9341 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9346 #if ENABLE_HUSH_EXPORT
9347 static int FAST_FUNC builtin_export(char **argv)
9349 unsigned opt_unexport;
9351 #if ENABLE_HUSH_EXPORT_N
9352 /* "!": do not abort on errors */
9353 opt_unexport = getopt32(argv, "!n");
9354 if (opt_unexport == (uint32_t)-1)
9355 return EXIT_FAILURE;
9362 if (argv[0] == NULL) {
9369 /* ash emits: export VAR='VAL'
9370 * bash: declare -x VAR="VAL"
9371 * we follow ash example */
9372 const char *s = *e++;
9373 const char *p = strchr(s, '=');
9375 if (!p) /* wtf? take next variable */
9378 printf("export %.*s", (int)(p - s) + 1, s);
9379 print_escaped(p + 1);
9383 /*fflush_all(); - done after each builtin anyway */
9385 return EXIT_SUCCESS;
9388 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9390 return EXIT_SUCCESS;
9394 #if ENABLE_HUSH_LOCAL
9395 static int FAST_FUNC builtin_local(char **argv)
9397 if (G.func_nest_level == 0) {
9398 bb_error_msg("%s: not in a function", argv[0]);
9399 return EXIT_FAILURE; /* bash compat */
9401 helper_export_local(argv, 0, G.func_nest_level);
9402 return EXIT_SUCCESS;
9406 #if ENABLE_HUSH_UNSET
9407 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9408 static int FAST_FUNC builtin_unset(char **argv)
9413 /* "!": do not abort on errors */
9414 /* "+": stop at 1st non-option */
9415 opts = getopt32(argv, "!+vf");
9416 if (opts == (unsigned)-1)
9417 return EXIT_FAILURE;
9419 bb_error_msg("unset: -v and -f are exclusive");
9420 return EXIT_FAILURE;
9426 if (!(opts & 2)) { /* not -f */
9427 if (unset_local_var(*argv)) {
9428 /* unset <nonexistent_var> doesn't fail.
9429 * Error is when one tries to unset RO var.
9430 * Message was printed by unset_local_var. */
9434 # if ENABLE_HUSH_FUNCTIONS
9446 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9447 * built-in 'set' handler
9449 * set [-abCefhmnuvx] [-o option] [argument...]
9450 * set [+abCefhmnuvx] [+o option] [argument...]
9451 * set -- [argument...]
9454 * Implementations shall support the options in both their hyphen and
9455 * plus-sign forms. These options can also be specified as options to sh.
9457 * Write out all variables and their values: set
9458 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9459 * Turn on the -x and -v options: set -xv
9460 * Unset all positional parameters: set --
9461 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9462 * Set the positional parameters to the expansion of x, even if x expands
9463 * with a leading '-' or '+': set -- $x
9465 * So far, we only support "set -- [argument...]" and some of the short names.
9467 static int FAST_FUNC builtin_set(char **argv)
9470 char **pp, **g_argv;
9471 char *arg = *++argv;
9475 for (e = G.top_var; e; e = e->next)
9477 return EXIT_SUCCESS;
9481 if (strcmp(arg, "--") == 0) {
9485 if (arg[0] != '+' && arg[0] != '-')
9487 for (n = 1; arg[n]; ++n) {
9488 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9490 if (arg[n] == 'o' && argv[1])
9493 } while ((arg = *++argv) != NULL);
9494 /* Now argv[0] is 1st argument */
9497 return EXIT_SUCCESS;
9500 /* NB: G.global_argv[0] ($0) is never freed/changed */
9501 g_argv = G.global_argv;
9502 if (G.global_args_malloced) {
9508 G.global_args_malloced = 1;
9509 pp = xzalloc(sizeof(pp[0]) * 2);
9510 pp[0] = g_argv[0]; /* retain $0 */
9513 /* This realloc's G.global_argv */
9514 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9516 G.global_argc = 1 + string_array_len(pp + 1);
9518 return EXIT_SUCCESS;
9520 /* Nothing known, so abort */
9522 bb_error_msg("set: %s: invalid option", arg);
9523 return EXIT_FAILURE;
9527 static int FAST_FUNC builtin_shift(char **argv)
9530 argv = skip_dash_dash(argv);
9532 n = bb_strtou(argv[0], NULL, 10);
9533 if (errno || n < 0) {
9534 /* shared string with ash.c */
9535 bb_error_msg("Illegal number: %s", argv[0]);
9537 * ash aborts in this case.
9538 * bash prints error message and set $? to 1.
9539 * Interestingly, for "shift 99999" bash does not
9540 * print error message, but does set $? to 1
9541 * (and does no shifting at all).
9545 if (n >= 0 && n < G.global_argc) {
9546 if (G_global_args_malloced) {
9549 free(G.global_argv[m++]);
9552 memmove(&G.global_argv[1], &G.global_argv[n+1],
9553 G.global_argc * sizeof(G.global_argv[0]));
9554 return EXIT_SUCCESS;
9556 return EXIT_FAILURE;
9559 static int FAST_FUNC builtin_source(char **argv)
9561 char *arg_path, *filename;
9564 char *args_need_save;
9565 #if ENABLE_HUSH_FUNCTIONS
9569 argv = skip_dash_dash(argv);
9572 /* bash says: "bash: .: filename argument required" */
9573 return 2; /* bash compat */
9576 if (!strchr(filename, '/')) {
9577 arg_path = find_in_path(filename);
9579 filename = arg_path;
9581 input = remember_FILE(fopen_or_warn(filename, "r"));
9584 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9585 /* POSIX: non-interactive shell should abort here,
9586 * not merely fail. So far no one complained :)
9588 return EXIT_FAILURE;
9591 #if ENABLE_HUSH_FUNCTIONS
9592 sv_flg = G_flag_return_in_progress;
9593 /* "we are inside sourced file, ok to use return" */
9594 G_flag_return_in_progress = -1;
9596 args_need_save = argv[1]; /* used as a boolean variable */
9598 save_and_replace_G_args(&sv, argv);
9600 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9601 G.last_exitcode = 0;
9602 parse_and_run_file(input);
9603 fclose_and_forget(input);
9605 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9606 restore_G_args(&sv, argv);
9607 #if ENABLE_HUSH_FUNCTIONS
9608 G_flag_return_in_progress = sv_flg;
9611 return G.last_exitcode;
9614 #if ENABLE_HUSH_TRAP
9615 static int FAST_FUNC builtin_trap(char **argv)
9621 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9626 /* No args: print all trapped */
9627 for (i = 0; i < NSIG; ++i) {
9630 print_escaped(G_traps[i]);
9631 /* note: bash adds "SIG", but only if invoked
9632 * as "bash". If called as "sh", or if set -o posix,
9633 * then it prints short signal names.
9634 * We are printing short names: */
9635 printf(" %s\n", get_signame(i));
9638 /*fflush_all(); - done after each builtin anyway */
9639 return EXIT_SUCCESS;
9643 /* If first arg is a number: reset all specified signals */
9644 sig = bb_strtou(*argv, NULL, 10);
9650 sighandler_t handler;
9652 sig = get_signum(*argv++);
9653 if (sig < 0 || sig >= NSIG) {
9655 /* Mimic bash message exactly */
9656 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9661 G_traps[sig] = xstrdup(new_cmd);
9663 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9664 get_signame(sig), sig, G_traps[sig]);
9666 /* There is no signal for 0 (EXIT) */
9671 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9673 /* We are removing trap handler */
9674 handler = pick_sighandler(sig);
9675 install_sighandler(sig, handler);
9680 if (!argv[1]) { /* no second arg */
9681 bb_error_msg("trap: invalid arguments");
9682 return EXIT_FAILURE;
9685 /* First arg is "-": reset all specified to default */
9686 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9687 /* Everything else: set arg as signal handler
9688 * (includes "" case, which ignores signal) */
9689 if (argv[0][0] == '-') {
9690 if (argv[0][1] == '\0') { /* "-" */
9691 /* new_cmd remains NULL: "reset these sigs" */
9694 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9697 /* else: "-something", no special meaning */
9702 goto process_sig_list;
9707 static struct pipe *parse_jobspec(const char *str)
9712 if (sscanf(str, "%%%u", &jobnum) != 1) {
9714 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9716 bb_error_msg("bad argument '%s'", str);
9719 /* It is "%%", "%+" or "%" - current job */
9720 jobnum = G.last_jobid;
9722 bb_error_msg("no current job");
9726 for (pi = G.job_list; pi; pi = pi->next) {
9727 if (pi->jobid == jobnum) {
9731 bb_error_msg("%u: no such job", jobnum);
9735 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9738 const char *status_string;
9740 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9741 for (job = G.job_list; job; job = job->next) {
9742 if (job->alive_cmds == job->stopped_cmds)
9743 status_string = "Stopped";
9745 status_string = "Running";
9747 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9750 clean_up_last_dead_job();
9752 return EXIT_SUCCESS;
9755 /* built-in 'fg' and 'bg' handler */
9756 static int FAST_FUNC builtin_fg_bg(char **argv)
9761 if (!G_interactive_fd)
9762 return EXIT_FAILURE;
9764 /* If they gave us no args, assume they want the last backgrounded task */
9766 for (pi = G.job_list; pi; pi = pi->next) {
9767 if (pi->jobid == G.last_jobid) {
9771 bb_error_msg("%s: no current job", argv[0]);
9772 return EXIT_FAILURE;
9775 pi = parse_jobspec(argv[1]);
9777 return EXIT_FAILURE;
9779 /* TODO: bash prints a string representation
9780 * of job being foregrounded (like "sleep 1 | cat") */
9781 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9782 /* Put the job into the foreground. */
9783 tcsetpgrp(G_interactive_fd, pi->pgrp);
9786 /* Restart the processes in the job */
9787 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9788 for (i = 0; i < pi->num_cmds; i++) {
9789 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9791 pi->stopped_cmds = 0;
9793 i = kill(- pi->pgrp, SIGCONT);
9795 if (errno == ESRCH) {
9796 delete_finished_job(pi);
9797 return EXIT_SUCCESS;
9799 bb_perror_msg("kill (SIGCONT)");
9802 if (argv[0][0] == 'f') {
9803 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9804 return checkjobs_and_fg_shell(pi);
9806 return EXIT_SUCCESS;
9810 #if ENABLE_HUSH_KILL
9811 static int FAST_FUNC builtin_kill(char **argv)
9815 # if ENABLE_HUSH_JOB
9816 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9824 if (argv[i][0] != '%')
9827 * "kill %N" - job kill
9828 * Converting to pgrp / pid kill
9830 pi = parse_jobspec(argv[i]);
9832 /* Eat bad jobspec */
9836 argv[j - 1] = argv[j];
9843 * In jobs started under job control, we signal
9844 * entire process group by kill -PGRP_ID.
9845 * This happens, f.e., in interactive shell.
9847 * Otherwise, we signal each child via
9848 * kill PID1 PID2 PID3.
9850 * sh -c 'sleep 1|sleep 1 & kill %1'
9851 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9852 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9854 n = G_interactive_fd ? 1 : pi->num_cmds;
9855 dst = alloca(n * sizeof(int)*4);
9857 if (G_interactive_fd)
9858 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9859 else for (j = 0; j < n; j++) {
9860 struct command *cmd = &pi->cmds[j];
9861 /* Skip exited members of the job */
9865 * kill_main has matching code to expect
9866 * leading space. Needed to not confuse
9867 * negative pids with "kill -SIGNAL_NO" syntax
9869 dst += sprintf(dst, " %u", (int)cmd->pid);
9872 } while (argv[++i]);
9876 if (argv[1] || ret == 0) {
9877 ret = run_applet_main(argv, kill_main);
9879 /* else: ret = 1, "kill %bad_jobspec" case */
9884 #if ENABLE_HUSH_WAIT
9885 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9886 #if !ENABLE_HUSH_JOB
9887 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9889 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9896 if (!sigisemptyset(&G.pending_set))
9899 /* waitpid is not interruptible by SA_RESTARTed
9900 * signals which we use. Thus, this ugly dance:
9903 /* Make sure possible SIGCHLD is stored in kernel's
9904 * pending signal mask before we call waitpid.
9905 * Or else we may race with SIGCHLD, lose it,
9906 * and get stuck in sigsuspend...
9908 sigfillset(&oldset); /* block all signals, remember old set */
9909 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9911 if (!sigisemptyset(&G.pending_set)) {
9912 /* Crap! we raced with some signal! */
9916 /*errno = 0; - checkjobs does this */
9917 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9918 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9919 debug_printf_exec("checkjobs:%d\n", ret);
9922 int rcode = job_exited_or_stopped(waitfor_pipe);
9923 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9926 sigprocmask(SIG_SETMASK, &oldset, NULL);
9931 /* if ECHILD, there are no children (ret is -1 or 0) */
9932 /* if ret == 0, no children changed state */
9933 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9934 if (errno == ECHILD || ret) {
9936 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9938 sigprocmask(SIG_SETMASK, &oldset, NULL);
9941 /* Wait for SIGCHLD or any other signal */
9942 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9943 /* Note: sigsuspend invokes signal handler */
9944 sigsuspend(&oldset);
9946 sigprocmask(SIG_SETMASK, &oldset, NULL);
9948 /* So, did we get a signal? */
9949 sig = check_and_run_traps();
9950 if (sig /*&& sig != SIGCHLD - always true */) {
9954 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9959 static int FAST_FUNC builtin_wait(char **argv)
9964 argv = skip_dash_dash(argv);
9965 if (argv[0] == NULL) {
9966 /* Don't care about wait results */
9967 /* Note 1: must wait until there are no more children */
9968 /* Note 2: must be interruptible */
9970 * $ sleep 3 & sleep 6 & wait
9975 * $ sleep 3 & sleep 6 & wait
9979 * ^C <-- after ~4 sec from keyboard
9982 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9986 pid_t pid = bb_strtou(*argv, NULL, 10);
9987 if (errno || pid <= 0) {
9989 if (argv[0][0] == '%') {
9990 struct pipe *wait_pipe;
9991 ret = 127; /* bash compat for bad jobspecs */
9992 wait_pipe = parse_jobspec(*argv);
9994 ret = job_exited_or_stopped(wait_pipe);
9996 ret = wait_for_child_or_signal(wait_pipe, 0);
9998 /* waiting on "last dead job" removes it */
9999 clean_up_last_dead_job();
10002 /* else: parse_jobspec() already emitted error msg */
10006 /* mimic bash message */
10007 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10008 ret = EXIT_FAILURE;
10009 continue; /* bash checks all argv[] */
10012 /* Do we have such child? */
10013 ret = waitpid(pid, &status, WNOHANG);
10017 if (errno == ECHILD) {
10018 if (pid == G.last_bg_pid) {
10019 /* "wait $!" but last bg task has already exited. Try:
10020 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10021 * In bash it prints exitcode 0, then 3.
10022 * In dash, it is 127.
10024 ret = G.last_bg_pid_exitcode;
10026 /* Example: "wait 1". mimic bash message */
10027 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10031 bb_perror_msg("wait %s", *argv);
10033 continue; /* bash checks all argv[] */
10036 /* Yes, and it still runs */
10037 ret = wait_for_child_or_signal(NULL, pid);
10039 /* Yes, and it just exited */
10040 process_wait_result(NULL, pid, status);
10041 ret = WEXITSTATUS(status);
10042 if (WIFSIGNALED(status))
10043 ret = 128 + WTERMSIG(status);
10051 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10052 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10055 def = bb_strtou(argv[1], NULL, 10);
10056 if (errno || def < def_min || argv[2]) {
10057 bb_error_msg("%s: bad arguments", argv[0]);
10065 #if ENABLE_HUSH_LOOPS
10066 static int FAST_FUNC builtin_break(char **argv)
10069 if (G.depth_of_loop == 0) {
10070 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10071 /* if we came from builtin_continue(), need to undo "= 1" */
10072 G.flag_break_continue = 0;
10073 return EXIT_SUCCESS; /* bash compat */
10075 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10077 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10078 if (depth == UINT_MAX)
10079 G.flag_break_continue = BC_BREAK;
10080 if (G.depth_of_loop < depth)
10081 G.depth_break_continue = G.depth_of_loop;
10083 return EXIT_SUCCESS;
10086 static int FAST_FUNC builtin_continue(char **argv)
10088 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10089 return builtin_break(argv);
10093 #if ENABLE_HUSH_FUNCTIONS
10094 static int FAST_FUNC builtin_return(char **argv)
10098 if (G_flag_return_in_progress != -1) {
10099 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10100 return EXIT_FAILURE; /* bash compat */
10103 G_flag_return_in_progress = 1;
10106 * out of range: wraps around at 256, does not error out
10107 * non-numeric param:
10108 * f() { false; return qwe; }; f; echo $?
10109 * bash: return: qwe: numeric argument required <== we do this
10110 * 255 <== we also do this
10112 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10117 #if ENABLE_HUSH_MEMLEAK
10118 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10123 # ifdef M_TRIM_THRESHOLD
10124 /* Optional. Reduces probability of false positives */
10127 /* Crude attempt to find where "free memory" starts,
10128 * sans fragmentation. */
10130 l = (unsigned long)p;
10133 if (l < (unsigned long)p) l = (unsigned long)p;
10139 struct mallinfo mi = mallinfo();
10140 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10141 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10145 if (!G.memleak_value)
10146 G.memleak_value = l;
10148 l -= G.memleak_value;
10155 /* Exitcode is "how many kilobytes we leaked since 1st call" */