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: Enable bash-compatible extensions.
105 //config:config HUSH_BRACE_EXPANSION
106 //config: bool "Brace expansion"
108 //config: depends on HUSH_BASH_COMPAT
110 //config: Enable {abc,def} extension.
112 //config:config HUSH_INTERACTIVE
113 //config: bool "Interactive mode"
115 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
117 //config: Enable interactive mode (prompt and command editing).
118 //config: Without this, hush simply reads and executes commands
119 //config: from stdin just like a shell script from a file.
120 //config: No prompt, no PS1/PS2 magic shell variables.
122 //config:config HUSH_SAVEHISTORY
123 //config: bool "Save command history to .hush_history"
125 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
127 //config: Enable history saving in hush.
129 //config:config HUSH_JOB
130 //config: bool "Job control"
132 //config: depends on HUSH_INTERACTIVE
134 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
135 //config: command (not entire shell), fg/bg builtins work. Without this option,
136 //config: "cmd &" still works by simply spawning a process and immediately
137 //config: prompting for next command (or executing next command in a script),
138 //config: but no separate process group is formed.
140 //config:config HUSH_TICK
141 //config: bool "Process substitution"
143 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
145 //config: Enable process substitution `command` and $(command) in hush.
147 //config:config HUSH_IF
148 //config: bool "Support if/then/elif/else/fi"
150 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
152 //config: Enable if/then/elif/else/fi in hush.
154 //config:config HUSH_LOOPS
155 //config: bool "Support for, while and until loops"
157 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
159 //config: Enable for, while and until loops in hush.
161 //config:config HUSH_CASE
162 //config: bool "Support case ... esac statement"
164 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
166 //config: Enable case ... esac statement in hush. +400 bytes.
168 //config:config HUSH_FUNCTIONS
169 //config: bool "Support funcname() { commands; } syntax"
171 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
173 //config: Enable support for shell functions in hush. +800 bytes.
175 //config:config HUSH_LOCAL
176 //config: bool "local builtin"
178 //config: depends on HUSH_FUNCTIONS
180 //config: Enable support for local variables in functions.
182 //config:config HUSH_RANDOM_SUPPORT
183 //config: bool "Pseudorandom generator and $RANDOM variable"
185 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
187 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
188 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
190 //config:config HUSH_MODE_X
191 //config: bool "Support 'hush -x' option and 'set -x' command"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config: This instructs hush to print commands before execution.
196 //config: Adds ~300 bytes.
198 //config:config HUSH_EXPORT
199 //config: bool "export builtin"
201 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
203 //config: Enable export builtin in hush.
205 //config:config HUSH_EXPORT_N
206 //config: bool "Support 'export -n' option"
208 //config: depends on HUSH_EXPORT
210 //config: export -n unexports variables. It is a bash extension.
212 //config:config HUSH_HELP
213 //config: bool "help builtin"
215 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
217 //config: Enable help builtin in hush. Code size + ~1 kbyte.
219 //config:config HUSH_PRINTF
220 //config: bool "printf builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config: Enable printf builtin in hush.
226 //config:config HUSH_KILL
227 //config: bool "kill builtin (for kill %jobspec)"
229 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
231 //config: Enable kill builtin in hush.
233 //config:config HUSH_WAIT
234 //config: bool "wait builtin"
236 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
238 //config: Enable wait builtin in hush.
240 //config:config HUSH_TRAP
241 //config: bool "trap builtin"
243 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
245 //config: Enable trap builtin in hush.
247 //config:config HUSH_ULIMIT
248 //config: bool "ulimit builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config: Enable ulimit builtin in hush.
254 //config:config HUSH_TYPE
255 //config: bool "type builtin"
257 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
259 //config: Enable type builtin in hush.
261 //config:config HUSH_READ
262 //config: bool "read builtin"
264 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
266 //config: Enable read builtin in hush.
268 //config:config HUSH_SET
269 //config: bool "set builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config: Enable set builtin in hush.
275 //config:config HUSH_UNSET
276 //config: bool "unset builtin"
278 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
280 //config: Enable unset builtin in hush.
282 //config:config HUSH_UMASK
283 //config: bool "umask builtin"
285 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
287 //config: Enable umask builtin in hush.
289 //config:config HUSH_MEMLEAK
290 //config: bool "memleak builtin (debugging)"
292 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
294 //config: Enable memleak builtin in hush.
297 //config: bool "msh (deprecated: aliased to hush)"
299 //config: select HUSH
301 //config: msh is deprecated and will be removed, please migrate to hush.
303 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
304 //applet:IF_MSH(APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
305 //applet:IF_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
306 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
308 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
309 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
310 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
311 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
313 /* -i (interactive) and -s (read stdin) are also accepted,
314 * but currently do nothing, therefore aren't shown in help.
315 * NOMMU-specific options are not meant to be used by users,
316 * therefore we don't show them either.
318 //usage:#define hush_trivial_usage
319 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
320 //usage:#define hush_full_usage "\n\n"
321 //usage: "Unix shell interpreter"
323 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
324 || defined(__APPLE__) \
326 # include <malloc.h> /* for malloc_trim */
329 /* #include <dmalloc.h> */
331 # include <fnmatch.h>
333 #include <sys/utsname.h> /* for setting $HOSTNAME */
335 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
337 #include "shell_common.h"
340 #if ENABLE_HUSH_RANDOM_SUPPORT
343 # define CLEAR_RANDOM_T(rnd) ((void)0)
345 #ifndef F_DUPFD_CLOEXEC
346 # define F_DUPFD_CLOEXEC F_DUPFD
349 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
354 #define LEAK_HUNTING 0
355 #define BUILD_AS_NOMMU 0
356 /* Enable/disable sanity checks. Ok to enable in production,
357 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
358 * Keeping 1 for now even in released versions.
361 /* Slightly bigger (+200 bytes), but faster hush.
362 * So far it only enables a trick with counting SIGCHLDs and forks,
363 * which allows us to do fewer waitpid's.
364 * (we can detect a case where neither forks were done nor SIGCHLDs happened
365 * and therefore waitpid will return the same result as last time)
367 #define ENABLE_HUSH_FAST 0
368 /* TODO: implement simplified code for users which do not need ${var%...} ops
369 * So far ${var%...} ops are always enabled:
371 #define ENABLE_HUSH_DOLLAR_OPS 1
376 # undef USE_FOR_NOMMU
379 # define USE_FOR_NOMMU(...) __VA_ARGS__
380 # define USE_FOR_MMU(...)
383 #include "NUM_APPLETS.h"
385 /* STANDALONE does not make sense, and won't compile */
386 # undef CONFIG_FEATURE_SH_STANDALONE
387 # undef ENABLE_FEATURE_SH_STANDALONE
388 # undef IF_FEATURE_SH_STANDALONE
389 # undef IF_NOT_FEATURE_SH_STANDALONE
390 # define ENABLE_FEATURE_SH_STANDALONE 0
391 # define IF_FEATURE_SH_STANDALONE(...)
392 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
395 #if !ENABLE_HUSH_INTERACTIVE
396 # undef ENABLE_FEATURE_EDITING
397 # define ENABLE_FEATURE_EDITING 0
398 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
399 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
400 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
401 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
404 /* Do we support ANY keywords? */
405 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
406 # define HAS_KEYWORDS 1
407 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
408 # define IF_HAS_NO_KEYWORDS(...)
410 # define HAS_KEYWORDS 0
411 # define IF_HAS_KEYWORDS(...)
412 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
415 /* If you comment out one of these below, it will be #defined later
416 * to perform debug printfs to stderr: */
417 #define debug_printf(...) do {} while (0)
418 /* Finer-grained debug switches */
419 #define debug_printf_parse(...) do {} while (0)
420 #define debug_print_tree(a, b) do {} while (0)
421 #define debug_printf_exec(...) do {} while (0)
422 #define debug_printf_env(...) do {} while (0)
423 #define debug_printf_jobs(...) do {} while (0)
424 #define debug_printf_expand(...) do {} while (0)
425 #define debug_printf_varexp(...) do {} while (0)
426 #define debug_printf_glob(...) do {} while (0)
427 #define debug_printf_list(...) do {} while (0)
428 #define debug_printf_subst(...) do {} while (0)
429 #define debug_printf_clean(...) do {} while (0)
431 #define ERR_PTR ((void*)(long)1)
433 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
435 #define _SPECIAL_VARS_STR "_*@$!?#"
436 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
437 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
438 #if ENABLE_HUSH_BASH_COMPAT
439 /* Support / and // replace ops */
440 /* Note that // is stored as \ in "encoded" string representation */
441 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
442 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
443 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
445 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
446 # define VAR_SUBST_OPS "%#:-=+?"
447 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
450 #define SPECIAL_VAR_SYMBOL 3
454 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
456 /* This supports saving pointers malloced in vfork child,
457 * to be freed in the parent.
460 typedef struct nommu_save_t {
462 struct variable *old_vars;
464 char **argv_from_re_execing;
477 #if ENABLE_HUSH_LOOPS
484 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
489 /* three pseudo-keywords support contrived "case" syntax: */
490 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
491 RES_MATCH , /* "word)" */
492 RES_CASE_BODY, /* "this command is inside CASE" */
499 typedef struct o_string {
501 int length; /* position where data is appended */
504 /* At least some part of the string was inside '' or "",
505 * possibly empty one: word"", wo''rd etc. */
506 smallint has_quoted_part;
507 smallint has_empty_slot;
508 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
511 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
513 /* Protect newly added chars against globbing
514 * by prepending \ to *, ?, [, \ */
515 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
518 MAYBE_ASSIGNMENT = 0,
519 DEFINITELY_ASSIGNMENT = 1,
521 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
524 /* Used for initialization: o_string foo = NULL_O_STRING; */
525 #define NULL_O_STRING { NULL }
527 #ifndef debug_printf_parse
528 static const char *const assignment_flag[] = {
530 "DEFINITELY_ASSIGNMENT",
536 typedef struct in_str {
538 #if ENABLE_HUSH_INTERACTIVE
539 smallint promptmode; /* 0: PS1, 1: PS2 */
546 /* The descrip member of this structure is only used to make
547 * debugging output pretty */
548 static const struct {
550 signed char default_fd;
553 { O_RDONLY, 0, "<" },
554 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
555 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
556 { O_CREAT|O_RDWR, 1, "<>" },
557 { O_RDONLY, 0, "<<" },
558 /* Should not be needed. Bogus default_fd helps in debugging */
559 /* { O_RDONLY, 77, "<<" }, */
562 struct redir_struct {
563 struct redir_struct *next;
564 char *rd_filename; /* filename */
565 int rd_fd; /* fd to redirect */
566 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
568 smallint rd_type; /* (enum redir_type) */
569 /* note: for heredocs, rd_filename contains heredoc delimiter,
570 * and subsequently heredoc itself; and rd_dup is a bitmask:
571 * bit 0: do we need to trim leading tabs?
572 * bit 1: is heredoc quoted (<<'delim' syntax) ?
575 typedef enum redir_type {
577 REDIRECT_OVERWRITE = 1,
580 REDIRECT_HEREDOC = 4,
581 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
584 REDIRFD_SYNTAX_ERR = -2,
585 REDIRFD_TO_FILE = -1,
586 /* otherwise, rd_fd is redirected to rd_dup */
588 HEREDOC_SKIPTABS = 1,
594 pid_t pid; /* 0 if exited */
595 int assignment_cnt; /* how many argv[i] are assignments? */
596 smallint cmd_type; /* CMD_xxx */
598 #define CMD_SUBSHELL 1
599 #if ENABLE_HUSH_BASH_COMPAT
600 /* used for "[[ EXPR ]]" */
601 # define CMD_SINGLEWORD_NOGLOB 2
603 #if ENABLE_HUSH_FUNCTIONS
604 # define CMD_FUNCDEF 3
607 smalluint cmd_exitcode;
608 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
611 char *group_as_string;
613 #if ENABLE_HUSH_FUNCTIONS
614 struct function *child_func;
615 /* This field is used to prevent a bug here:
616 * while...do f1() {a;}; f1; f1() {b;}; f1; done
617 * When we execute "f1() {a;}" cmd, we create new function and clear
618 * cmd->group, cmd->group_as_string, cmd->argv[0].
619 * When we execute "f1() {b;}", we notice that f1 exists,
620 * and that its "parent cmd" struct is still "alive",
621 * we put those fields back into cmd->xxx
622 * (struct function has ->parent_cmd ptr to facilitate that).
623 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
624 * Without this trick, loop would execute a;b;b;b;...
625 * instead of correct sequence a;b;a;b;...
626 * When command is freed, it severs the link
627 * (sets ->child_func->parent_cmd to NULL).
630 char **argv; /* command name and arguments */
631 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
632 * and on execution these are substituted with their values.
633 * Substitution can make _several_ words out of one argv[n]!
634 * Example: argv[0]=='.^C*^C.' here: echo .$*.
635 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
637 struct redir_struct *redirects; /* I/O redirections */
639 /* Is there anything in this command at all? */
640 #define IS_NULL_CMD(cmd) \
641 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
645 int num_cmds; /* total number of commands in pipe */
646 int alive_cmds; /* number of commands running (not exited) */
647 int stopped_cmds; /* number of commands alive, but stopped */
649 unsigned jobid; /* job number */
650 pid_t pgrp; /* process group ID for the job */
651 char *cmdtext; /* name of job */
653 struct command *cmds; /* array of commands in pipe */
654 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
655 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
656 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
658 typedef enum pipe_style {
664 /* Is there anything in this pipe at all? */
665 #define IS_NULL_PIPE(pi) \
666 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
668 /* This holds pointers to the various results of parsing */
669 struct parse_context {
670 /* linked list of pipes */
671 struct pipe *list_head;
672 /* last pipe (being constructed right now) */
674 /* last command in pipe (being constructed right now) */
675 struct command *command;
676 /* last redirect in command->redirects list */
677 struct redir_struct *pending_redirect;
683 smallint ctx_inverted; /* "! cmd | cmd" */
685 smallint ctx_dsemicolon; /* ";;" seen */
687 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
689 /* group we are enclosed in:
690 * example: "if pipe1; pipe2; then pipe3; fi"
691 * when we see "if" or "then", we malloc and copy current context,
692 * and make ->stack point to it. then we parse pipeN.
693 * when closing "then" / fi" / whatever is found,
694 * we move list_head into ->stack->command->group,
695 * copy ->stack into current context, and delete ->stack.
696 * (parsing of { list } and ( list ) doesn't use this method)
698 struct parse_context *stack;
702 /* On program start, environ points to initial environment.
703 * putenv adds new pointers into it, unsetenv removes them.
704 * Neither of these (de)allocates the strings.
705 * setenv allocates new strings in malloc space and does putenv,
706 * and thus setenv is unusable (leaky) for shell's purposes */
707 #define setenv(...) setenv_is_leaky_dont_use()
709 struct variable *next;
710 char *varstr; /* points to "name=" portion */
711 #if ENABLE_HUSH_LOCAL
712 unsigned func_nest_level;
714 int max_len; /* if > 0, name is part of initial env; else name is malloced */
715 smallint flg_export; /* putenv should be done on this var */
716 smallint flg_read_only;
724 #if ENABLE_HUSH_FUNCTIONS
726 struct function *next;
728 struct command *parent_cmd;
731 char *body_as_string;
737 /* set -/+o OPT support. (TODO: make it optional)
738 * bash supports the following opts:
749 * interactive-comments on
767 static const char o_opt_strings[] ALIGN1 =
770 #if ENABLE_HUSH_MODE_X
777 #if ENABLE_HUSH_MODE_X
785 struct FILE_list *next;
791 /* "Globals" within this file */
792 /* Sorted roughly by size (smaller offsets == smaller code) */
794 /* interactive_fd != 0 means we are an interactive shell.
795 * If we are, then saved_tty_pgrp can also be != 0, meaning
796 * that controlling tty is available. With saved_tty_pgrp == 0,
797 * job control still works, but terminal signals
798 * (^C, ^Z, ^Y, ^\) won't work at all, and background
799 * process groups can only be created with "cmd &".
800 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
801 * to give tty to the foreground process group,
802 * and will take it back when the group is stopped (^Z)
805 #if ENABLE_HUSH_INTERACTIVE
806 /* 'interactive_fd' is a fd# open to ctty, if we have one
807 * _AND_ if we decided to act interactively */
811 # define G_interactive_fd (G.interactive_fd)
813 # define G_interactive_fd 0
815 #if ENABLE_FEATURE_EDITING
816 line_input_t *line_input_state;
821 #if ENABLE_HUSH_RANDOM_SUPPORT
827 pid_t saved_tty_pgrp;
828 struct pipe *job_list;
829 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
831 # define G_saved_tty_pgrp 0
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 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
857 smalluint global_args_malloced;
858 /* how many non-NULL argv's we have. NB: $# + 1 */
862 char *argv0_for_re_execing;
864 #if ENABLE_HUSH_LOOPS
865 unsigned depth_break_continue;
866 unsigned depth_of_loop;
870 struct variable *top_var;
871 char **expanded_assignments;
872 #if ENABLE_HUSH_FUNCTIONS
873 struct function *top_func;
874 # if ENABLE_HUSH_LOCAL
875 struct variable **shadowed_vars_pp;
876 unsigned func_nest_level;
879 /* Signal and trap handling */
881 unsigned count_SIGCHLD;
882 unsigned handled_SIGCHLD;
883 smallint we_have_children;
885 struct FILE_list *FILE_list;
886 /* Which signals have non-DFL handler (even with no traps set)?
887 * Set at the start to:
888 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
889 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
890 * The rest is cleared right before execv syscalls.
891 * Other than these two times, never modified.
893 unsigned special_sig_mask;
895 unsigned fatal_sig_mask;
896 # define G_fatal_sig_mask G.fatal_sig_mask
898 # define G_fatal_sig_mask 0
901 char **traps; /* char *traps[NSIG] */
902 # define G_traps G.traps
904 # define G_traps ((char**)NULL)
906 sigset_t pending_set;
907 #if ENABLE_HUSH_MEMLEAK
908 unsigned long memleak_value;
914 #if ENABLE_FEATURE_EDITING
915 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
918 #define G (*ptr_to_globals)
919 /* Not #defining name to G.name - this quickly gets unwieldy
920 * (too many defines). Also, I actually prefer to see when a variable
921 * is global, thus "G." prefix is a useful hint */
922 #define INIT_G() do { \
923 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
924 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
925 sigfillset(&G.sa.sa_mask); \
926 G.sa.sa_flags = SA_RESTART; \
930 /* Function prototypes for builtins */
931 static int builtin_cd(char **argv) FAST_FUNC;
932 static int builtin_echo(char **argv) FAST_FUNC;
933 static int builtin_eval(char **argv) FAST_FUNC;
934 static int builtin_exec(char **argv) FAST_FUNC;
935 static int builtin_exit(char **argv) FAST_FUNC;
936 #if ENABLE_HUSH_EXPORT
937 static int builtin_export(char **argv) FAST_FUNC;
940 static int builtin_fg_bg(char **argv) FAST_FUNC;
941 static int builtin_jobs(char **argv) FAST_FUNC;
944 static int builtin_help(char **argv) FAST_FUNC;
946 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
947 static int builtin_history(char **argv) FAST_FUNC;
949 #if ENABLE_HUSH_LOCAL
950 static int builtin_local(char **argv) FAST_FUNC;
952 #if ENABLE_HUSH_MEMLEAK
953 static int builtin_memleak(char **argv) FAST_FUNC;
955 #if ENABLE_HUSH_PRINTF
956 static int builtin_printf(char **argv) FAST_FUNC;
958 static int builtin_pwd(char **argv) FAST_FUNC;
960 static int builtin_read(char **argv) FAST_FUNC;
963 static int builtin_set(char **argv) FAST_FUNC;
965 static int builtin_shift(char **argv) FAST_FUNC;
966 static int builtin_source(char **argv) FAST_FUNC;
967 static int builtin_test(char **argv) FAST_FUNC;
969 static int builtin_trap(char **argv) FAST_FUNC;
972 static int builtin_type(char **argv) FAST_FUNC;
974 static int builtin_true(char **argv) FAST_FUNC;
975 #if ENABLE_HUSH_UMASK
976 static int builtin_umask(char **argv) FAST_FUNC;
978 #if ENABLE_HUSH_UNSET
979 static int builtin_unset(char **argv) FAST_FUNC;
982 static int builtin_kill(char **argv) FAST_FUNC;
985 static int builtin_wait(char **argv) FAST_FUNC;
987 #if ENABLE_HUSH_LOOPS
988 static int builtin_break(char **argv) FAST_FUNC;
989 static int builtin_continue(char **argv) FAST_FUNC;
991 #if ENABLE_HUSH_FUNCTIONS
992 static int builtin_return(char **argv) FAST_FUNC;
995 /* Table of built-in functions. They can be forked or not, depending on
996 * context: within pipes, they fork. As simple commands, they do not.
997 * When used in non-forking context, they can change global variables
998 * in the parent shell process. If forked, of course they cannot.
999 * For example, 'unset foo | whatever' will parse and run, but foo will
1000 * still be set at the end. */
1001 struct built_in_command {
1003 int (*b_function)(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_HELP
1005 const char *b_descr;
1006 # define BLTIN(cmd, func, help) { cmd, func, help }
1008 # define BLTIN(cmd, func, help) { cmd, func }
1012 static const struct built_in_command bltins1[] = {
1013 BLTIN("." , builtin_source , "Run commands in a file"),
1014 BLTIN(":" , builtin_true , NULL),
1016 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
1018 #if ENABLE_HUSH_LOOPS
1019 BLTIN("break" , builtin_break , "Exit from a loop"),
1021 BLTIN("cd" , builtin_cd , "Change directory"),
1022 #if ENABLE_HUSH_LOOPS
1023 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1025 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1026 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1027 BLTIN("exit" , builtin_exit , "Exit"),
1028 #if ENABLE_HUSH_EXPORT
1029 BLTIN("export" , builtin_export , "Set environment variables"),
1032 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
1034 #if ENABLE_HUSH_HELP
1035 BLTIN("help" , builtin_help , NULL),
1037 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1038 BLTIN("history" , builtin_history , "Show command history"),
1041 BLTIN("jobs" , builtin_jobs , "List jobs"),
1043 #if ENABLE_HUSH_KILL
1044 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1046 #if ENABLE_HUSH_LOCAL
1047 BLTIN("local" , builtin_local , "Set local variables"),
1049 #if ENABLE_HUSH_MEMLEAK
1050 BLTIN("memleak" , builtin_memleak , NULL),
1052 #if ENABLE_HUSH_READ
1053 BLTIN("read" , builtin_read , "Input into variable"),
1055 #if ENABLE_HUSH_FUNCTIONS
1056 BLTIN("return" , builtin_return , "Return from a function"),
1059 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
1061 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1062 #if ENABLE_HUSH_BASH_COMPAT
1063 BLTIN("source" , builtin_source , "Run commands in a file"),
1065 #if ENABLE_HUSH_TRAP
1066 BLTIN("trap" , builtin_trap , "Trap signals"),
1068 BLTIN("true" , builtin_true , NULL),
1069 #if ENABLE_HUSH_TYPE
1070 BLTIN("type" , builtin_type , "Show command type"),
1072 #if ENABLE_HUSH_ULIMIT
1073 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1075 #if ENABLE_HUSH_UMASK
1076 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1078 #if ENABLE_HUSH_UNSET
1079 BLTIN("unset" , builtin_unset , "Unset variables"),
1081 #if ENABLE_HUSH_WAIT
1082 BLTIN("wait" , builtin_wait , "Wait for process"),
1085 /* For now, echo and test are unconditionally enabled.
1086 * Maybe make it configurable? */
1087 static const struct built_in_command bltins2[] = {
1088 BLTIN("[" , builtin_test , NULL),
1089 BLTIN("echo" , builtin_echo , NULL),
1090 #if ENABLE_HUSH_PRINTF
1091 BLTIN("printf" , builtin_printf , NULL),
1093 BLTIN("pwd" , builtin_pwd , NULL),
1094 BLTIN("test" , builtin_test , NULL),
1101 /* prevent disasters with G.debug_indent < 0 */
1102 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1103 # define debug_enter() (G.debug_indent++)
1104 # define debug_leave() (G.debug_indent--)
1106 # define indent() ((void)0)
1107 # define debug_enter() ((void)0)
1108 # define debug_leave() ((void)0)
1111 #ifndef debug_printf
1112 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1115 #ifndef debug_printf_parse
1116 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1119 #ifndef debug_printf_exec
1120 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1123 #ifndef debug_printf_env
1124 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1127 #ifndef debug_printf_jobs
1128 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1129 # define DEBUG_JOBS 1
1131 # define DEBUG_JOBS 0
1134 #ifndef debug_printf_expand
1135 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1136 # define DEBUG_EXPAND 1
1138 # define DEBUG_EXPAND 0
1141 #ifndef debug_printf_varexp
1142 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1145 #ifndef debug_printf_glob
1146 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1147 # define DEBUG_GLOB 1
1149 # define DEBUG_GLOB 0
1152 #ifndef debug_printf_list
1153 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1156 #ifndef debug_printf_subst
1157 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1160 #ifndef debug_printf_clean
1161 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1162 # define DEBUG_CLEAN 1
1164 # define DEBUG_CLEAN 0
1168 static void debug_print_strings(const char *prefix, char **vv)
1171 fdprintf(2, "%s:\n", prefix);
1173 fdprintf(2, " '%s'\n", *vv++);
1176 # define debug_print_strings(prefix, vv) ((void)0)
1180 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1183 static void *xxmalloc(int lineno, size_t size)
1185 void *ptr = xmalloc((size + 0xff) & ~0xff);
1186 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1189 static void *xxrealloc(int lineno, void *ptr, size_t size)
1191 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1192 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1195 static char *xxstrdup(int lineno, const char *str)
1197 char *ptr = xstrdup(str);
1198 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1201 static void xxfree(void *ptr)
1203 fdprintf(2, "free %p\n", ptr);
1206 # define xmalloc(s) xxmalloc(__LINE__, s)
1207 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1208 # define xstrdup(s) xxstrdup(__LINE__, s)
1209 # define free(p) xxfree(p)
1213 /* Syntax and runtime errors. They always abort scripts.
1214 * In interactive use they usually discard unparsed and/or unexecuted commands
1215 * and return to the prompt.
1216 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1219 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1220 # define syntax_error(lineno, msg) syntax_error(msg)
1221 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1222 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1223 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1224 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1227 static void die_if_script(unsigned lineno, const char *fmt, ...)
1232 bb_error_msg("hush.c:%u", lineno);
1235 bb_verror_msg(fmt, p, NULL);
1237 if (!G_interactive_fd)
1241 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1244 bb_error_msg("syntax error: %s", msg);
1246 bb_error_msg("syntax error");
1249 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1251 bb_error_msg("syntax error at '%s'", msg);
1254 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1256 bb_error_msg("syntax error: unterminated %s", s);
1259 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1261 char msg[2] = { ch, '\0' };
1262 syntax_error_unterm_str(lineno, msg);
1265 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1271 bb_error_msg("hush.c:%u", lineno);
1273 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1277 # undef die_if_script
1278 # undef syntax_error
1279 # undef syntax_error_at
1280 # undef syntax_error_unterm_ch
1281 # undef syntax_error_unterm_str
1282 # undef syntax_error_unexpected_ch
1284 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1285 # define syntax_error(msg) syntax_error(__LINE__, msg)
1286 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1287 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1288 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1289 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1293 #if ENABLE_HUSH_INTERACTIVE
1294 static void cmdedit_update_prompt(void);
1296 # define cmdedit_update_prompt() ((void)0)
1300 /* Utility functions
1302 /* Replace each \x with x in place, return ptr past NUL. */
1303 static char *unbackslash(char *src)
1305 char *dst = src = strchrnul(src, '\\');
1309 if ((*dst++ = *src++) == '\0')
1315 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1336 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1337 v[count1 + count2] = NULL;
1340 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1344 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1346 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1347 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1350 #define add_strings_to_strings(strings, add, need_to_dup) \
1351 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1354 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1355 static char **add_string_to_strings(char **strings, char *add)
1360 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1363 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1365 char **ptr = add_string_to_strings(strings, add);
1366 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1369 #define add_string_to_strings(strings, add) \
1370 xx_add_string_to_strings(__LINE__, strings, add)
1373 static void free_strings(char **strings)
1388 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1390 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1391 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1393 /* fd was not open? */
1403 /* Manipulating the list of open FILEs */
1404 static FILE *remember_FILE(FILE *fp)
1407 struct FILE_list *n = xmalloc(sizeof(*n));
1408 n->next = G.FILE_list;
1412 close_on_exec_on(n->fd);
1416 static void fclose_and_forget(FILE *fp)
1418 struct FILE_list **pp = &G.FILE_list;
1420 struct FILE_list *cur = *pp;
1421 if (cur->fp == fp) {
1430 static int save_FILEs_on_redirect(int fd)
1432 struct FILE_list *fl = G.FILE_list;
1435 /* We use it only on script files, they are all CLOEXEC */
1436 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1443 static void restore_redirected_FILEs(void)
1445 struct FILE_list *fl = G.FILE_list;
1447 int should_be = fileno(fl->fp);
1448 if (fl->fd != should_be) {
1449 xmove_fd(fl->fd, should_be);
1455 #if ENABLE_FEATURE_SH_STANDALONE
1456 static void close_all_FILE_list(void)
1458 struct FILE_list *fl = G.FILE_list;
1460 /* fclose would also free FILE object.
1461 * It is disastrous if we share memory with a vforked parent.
1462 * I'm not sure we never come here after vfork.
1463 * Therefore just close fd, nothing more.
1465 /*fclose(fl->fp); - unsafe */
1473 /* Helpers for setting new $n and restoring them back
1475 typedef struct save_arg_t {
1479 smallint sv_g_malloced;
1482 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1486 sv->sv_argv0 = argv[0];
1487 sv->sv_g_argv = G.global_argv;
1488 sv->sv_g_argc = G.global_argc;
1489 sv->sv_g_malloced = G.global_args_malloced;
1491 argv[0] = G.global_argv[0]; /* retain $0 */
1492 G.global_argv = argv;
1493 G.global_args_malloced = 0;
1501 static void restore_G_args(save_arg_t *sv, char **argv)
1505 if (G.global_args_malloced) {
1506 /* someone ran "set -- arg1 arg2 ...", undo */
1508 while (*++pp) /* note: does not free $0 */
1510 free(G.global_argv);
1512 argv[0] = sv->sv_argv0;
1513 G.global_argv = sv->sv_g_argv;
1514 G.global_argc = sv->sv_g_argc;
1515 G.global_args_malloced = sv->sv_g_malloced;
1519 /* Basic theory of signal handling in shell
1520 * ========================================
1521 * This does not describe what hush does, rather, it is current understanding
1522 * what it _should_ do. If it doesn't, it's a bug.
1523 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1525 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1526 * is finished or backgrounded. It is the same in interactive and
1527 * non-interactive shells, and is the same regardless of whether
1528 * a user trap handler is installed or a shell special one is in effect.
1529 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1530 * backgrounds (i.e. stops) or kills all members of currently running
1533 * Wait builtin is interruptible by signals for which user trap is set
1534 * or by SIGINT in interactive shell.
1536 * Trap handlers will execute even within trap handlers. (right?)
1538 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1539 * except for handlers set to '' (empty string).
1541 * If job control is off, backgrounded commands ("cmd &")
1542 * have SIGINT, SIGQUIT set to SIG_IGN.
1544 * Commands which are run in command substitution ("`cmd`")
1545 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1547 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1548 * by the shell from its parent.
1550 * Signals which differ from SIG_DFL action
1551 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1554 * SIGTERM (interactive): ignore
1555 * SIGHUP (interactive):
1556 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1557 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1558 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1559 * that all pipe members are stopped. Try this in bash:
1560 * while :; do :; done - ^Z does not background it
1561 * (while :; do :; done) - ^Z backgrounds it
1562 * SIGINT (interactive): wait for last pipe, ignore the rest
1563 * of the command line, show prompt. NB: ^C does not send SIGINT
1564 * to interactive shell while shell is waiting for a pipe,
1565 * since shell is bg'ed (is not in foreground process group).
1566 * Example 1: this waits 5 sec, but does not execute ls:
1567 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1568 * Example 2: this does not wait and does not execute ls:
1569 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1570 * Example 3: this does not wait 5 sec, but executes ls:
1571 * "sleep 5; ls -l" + press ^C
1572 * Example 4: this does not wait and does not execute ls:
1573 * "sleep 5 & wait; ls -l" + press ^C
1575 * (What happens to signals which are IGN on shell start?)
1576 * (What happens with signal mask on shell start?)
1578 * Old implementation
1579 * ==================
1580 * We use in-kernel pending signal mask to determine which signals were sent.
1581 * We block all signals which we don't want to take action immediately,
1582 * i.e. we block all signals which need to have special handling as described
1583 * above, and all signals which have traps set.
1584 * After each pipe execution, we extract any pending signals via sigtimedwait()
1587 * unsigned special_sig_mask: a mask of such "special" signals
1588 * sigset_t blocked_set: current blocked signal set
1591 * clear bit in blocked_set unless it is also in special_sig_mask
1592 * "trap 'cmd' SIGxxx":
1593 * set bit in blocked_set (even if 'cmd' is '')
1594 * after [v]fork, if we plan to be a shell:
1595 * unblock signals with special interactive handling
1596 * (child shell is not interactive),
1597 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1598 * after [v]fork, if we plan to exec:
1599 * POSIX says fork clears pending signal mask in child - no need to clear it.
1600 * Restore blocked signal set to one inherited by shell just prior to exec.
1602 * Note: as a result, we do not use signal handlers much. The only uses
1603 * are to count SIGCHLDs
1604 * and to restore tty pgrp on signal-induced exit.
1607 * Standard says "When a subshell is entered, traps that are not being ignored
1608 * are set to the default actions". bash interprets it so that traps which
1609 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1611 * Problem: the above approach makes it unwieldy to catch signals while
1612 * we are in read builtin, or while we read commands from stdin:
1613 * masked signals are not visible!
1615 * New implementation
1616 * ==================
1617 * We record each signal we are interested in by installing signal handler
1618 * for them - a bit like emulating kernel pending signal mask in userspace.
1619 * We are interested in: signals which need to have special handling
1620 * as described above, and all signals which have traps set.
1621 * Signals are recorded in pending_set.
1622 * After each pipe execution, we extract any pending signals
1625 * unsigned special_sig_mask: a mask of shell-special signals.
1626 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1627 * char *traps[sig] if trap for sig is set (even if it's '').
1628 * sigset_t pending_set: set of sigs we received.
1631 * if sig is in special_sig_mask, set handler back to:
1632 * record_pending_signo, or to IGN if it's a tty stop signal
1633 * if sig is in fatal_sig_mask, set handler back to sigexit.
1634 * else: set handler back to SIG_DFL
1635 * "trap 'cmd' SIGxxx":
1636 * set handler to record_pending_signo.
1638 * set handler to SIG_IGN.
1639 * after [v]fork, if we plan to be a shell:
1640 * set signals with special interactive handling to SIG_DFL
1641 * (because child shell is not interactive),
1642 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1643 * after [v]fork, if we plan to exec:
1644 * POSIX says fork clears pending signal mask in child - no need to clear it.
1646 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1647 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1650 * Standard says "When a subshell is entered, traps that are not being ignored
1651 * are set to the default actions". bash interprets it so that traps which
1652 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1655 SPECIAL_INTERACTIVE_SIGS = 0
1660 SPECIAL_JOBSTOP_SIGS = 0
1669 static void record_pending_signo(int sig)
1671 sigaddset(&G.pending_set, sig);
1672 #if ENABLE_HUSH_FAST
1673 if (sig == SIGCHLD) {
1675 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1680 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1682 struct sigaction old_sa;
1684 /* We could use signal() to install handlers... almost:
1685 * except that we need to mask ALL signals while handlers run.
1686 * I saw signal nesting in strace, race window isn't small.
1687 * SA_RESTART is also needed, but in Linux, signal()
1688 * sets SA_RESTART too.
1690 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1691 /* sigfillset(&G.sa.sa_mask); - already done */
1692 /* G.sa.sa_flags = SA_RESTART; - already done */
1693 G.sa.sa_handler = handler;
1694 sigaction(sig, &G.sa, &old_sa);
1695 return old_sa.sa_handler;
1698 static void hush_exit(int exitcode) NORETURN;
1700 static void restore_ttypgrp_and__exit(void) NORETURN;
1701 static void restore_ttypgrp_and__exit(void)
1703 /* xfunc has failed! die die die */
1704 /* no EXIT traps, this is an escape hatch! */
1706 hush_exit(xfunc_error_retval);
1711 /* Needed only on some libc:
1712 * It was observed that on exit(), fgetc'ed buffered data
1713 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1714 * With the net effect that even after fork(), not vfork(),
1715 * exit() in NOEXECed applet in "sh SCRIPT":
1716 * noexec_applet_here
1717 * echo END_OF_SCRIPT
1718 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1719 * This makes "echo END_OF_SCRIPT" executed twice.
1720 * Similar problems can be seen with die_if_script() -> xfunc_die()
1721 * and in `cmd` handling.
1722 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1724 static void fflush_and__exit(void) NORETURN;
1725 static void fflush_and__exit(void)
1728 _exit(xfunc_error_retval);
1731 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1732 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1733 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1734 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1736 /* Restores tty foreground process group, and exits.
1737 * May be called as signal handler for fatal signal
1738 * (will resend signal to itself, producing correct exit state)
1739 * or called directly with -EXITCODE.
1740 * We also call it if xfunc is exiting.
1742 static void sigexit(int sig) NORETURN;
1743 static void sigexit(int sig)
1745 /* Careful: we can end up here after [v]fork. Do not restore
1746 * tty pgrp then, only top-level shell process does that */
1747 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1748 /* Disable all signals: job control, SIGPIPE, etc.
1749 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1751 sigprocmask_allsigs(SIG_BLOCK);
1752 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1755 /* Not a signal, just exit */
1759 kill_myself_with_sig(sig); /* does not return */
1763 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1764 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1768 static sighandler_t pick_sighandler(unsigned sig)
1770 sighandler_t handler = SIG_DFL;
1771 if (sig < sizeof(unsigned)*8) {
1772 unsigned sigmask = (1 << sig);
1776 if (G_fatal_sig_mask & sigmask)
1780 /* sig has special handling? */
1781 if (G.special_sig_mask & sigmask) {
1782 handler = record_pending_signo;
1783 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1784 * in order to ignore them: they will be raised
1785 * in an endless loop when we try to do some
1786 * terminal ioctls! We do have to _ignore_ these.
1788 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1795 /* Restores tty foreground process group, and exits. */
1796 static void hush_exit(int exitcode)
1798 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1799 save_history(G.line_input_state);
1803 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1805 /* argv[0] is unused */
1806 argv[1] = G_traps[0];
1808 G.exiting = 1; /* prevent EXIT trap recursion */
1809 /* Note: G_traps[0] is not cleared!
1810 * "trap" will still show it, if executed
1815 #if ENABLE_FEATURE_CLEAN_UP
1817 struct variable *cur_var;
1818 if (G.cwd != bb_msg_unknown)
1820 cur_var = G.top_var;
1822 struct variable *tmp = cur_var;
1823 if (!cur_var->max_len)
1824 free(cur_var->varstr);
1825 cur_var = cur_var->next;
1833 sigexit(- (exitcode & 0xff));
1840 //TODO: return a mask of ALL handled sigs?
1841 static int check_and_run_traps(void)
1848 if (sigisemptyset(&G.pending_set))
1853 if (sigismember(&G.pending_set, sig)) {
1854 sigdelset(&G.pending_set, sig);
1857 } while (sig < NSIG);
1860 if (G_traps && G_traps[sig]) {
1861 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1862 if (G_traps[sig][0]) {
1863 /* We have user-defined handler */
1864 smalluint save_rcode;
1866 /* argv[0] is unused */
1867 argv[1] = G_traps[sig];
1869 save_rcode = G.last_exitcode;
1871 //FIXME: shouldn't it be set to 128 + sig instead?
1872 G.last_exitcode = save_rcode;
1874 } /* else: "" trap, ignoring signal */
1877 /* not a trap: special action */
1880 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1887 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1888 /* bash is observed to signal whole process groups,
1889 * not individual processes */
1890 for (job = G.job_list; job; job = job->next) {
1893 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1894 if (kill(- job->pgrp, SIGHUP) == 0)
1895 kill(- job->pgrp, SIGCONT);
1900 #if ENABLE_HUSH_FAST
1902 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1904 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1906 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1907 * This simplifies wait builtin a bit.
1911 default: /* ignored: */
1912 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1913 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1915 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1916 * Example: wait is not interrupted by TERM
1917 * in interactive shell, because TERM is ignored.
1926 static const char *get_cwd(int force)
1928 if (force || G.cwd == NULL) {
1929 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1930 * we must not try to free(bb_msg_unknown) */
1931 if (G.cwd == bb_msg_unknown)
1933 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1935 G.cwd = bb_msg_unknown;
1942 * Shell and environment variable support
1944 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1946 struct variable **pp;
1947 struct variable *cur;
1950 while ((cur = *pp) != NULL) {
1951 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1958 static const char* FAST_FUNC get_local_var_value(const char *name)
1960 struct variable **vpp;
1961 unsigned len = strlen(name);
1963 if (G.expanded_assignments) {
1964 char **cpp = G.expanded_assignments;
1967 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1968 return cp + len + 1;
1973 vpp = get_ptr_to_local_var(name, len);
1975 return (*vpp)->varstr + len + 1;
1977 if (strcmp(name, "PPID") == 0)
1978 return utoa(G.root_ppid);
1979 // bash compat: UID? EUID?
1980 #if ENABLE_HUSH_RANDOM_SUPPORT
1981 if (strcmp(name, "RANDOM") == 0)
1982 return utoa(next_random(&G.random_gen));
1987 /* str holds "NAME=VAL" and is expected to be malloced.
1988 * We take ownership of it.
1990 * 0: do not change export flag
1991 * (if creating new variable, flag will be 0)
1992 * 1: set export flag and putenv the variable
1993 * -1: clear export flag and unsetenv the variable
1994 * flg_read_only is set only when we handle -R var=val
1996 #if !BB_MMU && ENABLE_HUSH_LOCAL
1997 /* all params are used */
1998 #elif BB_MMU && ENABLE_HUSH_LOCAL
1999 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2000 set_local_var(str, flg_export, local_lvl)
2001 #elif BB_MMU && !ENABLE_HUSH_LOCAL
2002 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2003 set_local_var(str, flg_export)
2004 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2005 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2006 set_local_var(str, flg_export, flg_read_only)
2008 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2010 struct variable **var_pp;
2011 struct variable *cur;
2012 char *free_me = NULL;
2016 eq_sign = strchr(str, '=');
2017 if (!eq_sign) { /* not expected to ever happen? */
2022 name_len = eq_sign - str + 1; /* including '=' */
2023 var_pp = &G.top_var;
2024 while ((cur = *var_pp) != NULL) {
2025 if (strncmp(cur->varstr, str, name_len) != 0) {
2026 var_pp = &cur->next;
2030 /* We found an existing var with this name */
2031 if (cur->flg_read_only) {
2035 bb_error_msg("%s: readonly variable", str);
2039 if (flg_export == -1) { // "&& cur->flg_export" ?
2040 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2045 #if ENABLE_HUSH_LOCAL
2046 if (cur->func_nest_level < local_lvl) {
2047 /* New variable is declared as local,
2048 * and existing one is global, or local
2049 * from enclosing function.
2050 * Remove and save old one: */
2051 *var_pp = cur->next;
2052 cur->next = *G.shadowed_vars_pp;
2053 *G.shadowed_vars_pp = cur;
2054 /* bash 3.2.33(1) and exported vars:
2056 * # f() { local z=a; env | grep ^z; }
2062 if (cur->flg_export)
2067 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2072 if (cur->max_len != 0) {
2073 if (cur->max_len >= strlen(str)) {
2074 /* This one is from startup env, reuse space */
2075 strcpy(cur->varstr, str);
2080 goto set_str_and_exp;
2082 /* max_len == 0 signifies "malloced" var, which we can
2083 * (and have to) free. But we can't free(cur->varstr) here:
2084 * if cur->flg_export is 1, it is in the environment.
2085 * We should either unsetenv+free, or wait until putenv,
2086 * then putenv(new)+free(old).
2088 free_me = cur->varstr;
2089 goto set_str_and_exp;
2092 /* Not found - create new variable struct */
2093 cur = xzalloc(sizeof(*cur));
2094 #if ENABLE_HUSH_LOCAL
2095 cur->func_nest_level = local_lvl;
2097 cur->next = *var_pp;
2103 cur->flg_read_only = flg_read_only;
2106 if (flg_export == 1)
2107 cur->flg_export = 1;
2108 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2109 cmdedit_update_prompt();
2110 if (cur->flg_export) {
2111 if (flg_export == -1) {
2112 cur->flg_export = 0;
2113 /* unsetenv was already done */
2116 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2117 i = putenv(cur->varstr);
2118 /* only now we can free old exported malloced string */
2127 /* Used at startup and after each cd */
2128 static void set_pwd_var(int exp)
2130 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2131 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2134 static int unset_local_var_len(const char *name, int name_len)
2136 struct variable *cur;
2137 struct variable **var_pp;
2140 return EXIT_SUCCESS;
2141 var_pp = &G.top_var;
2142 while ((cur = *var_pp) != NULL) {
2143 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2144 if (cur->flg_read_only) {
2145 bb_error_msg("%s: readonly variable", name);
2146 return EXIT_FAILURE;
2148 *var_pp = cur->next;
2149 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2150 bb_unsetenv(cur->varstr);
2151 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2152 cmdedit_update_prompt();
2156 return EXIT_SUCCESS;
2158 var_pp = &cur->next;
2160 return EXIT_SUCCESS;
2163 #if ENABLE_HUSH_UNSET
2164 static int unset_local_var(const char *name)
2166 return unset_local_var_len(name, strlen(name));
2170 static void unset_vars(char **strings)
2178 const char *eq = strchrnul(*v, '=');
2179 unset_local_var_len(*v, (int)(eq - *v));
2185 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2187 char *var = xasprintf("%s=%s", name, val);
2188 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2193 * Helpers for "var1=val1 var2=val2 cmd" feature
2195 static void add_vars(struct variable *var)
2197 struct variable *next;
2201 var->next = G.top_var;
2203 if (var->flg_export) {
2204 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2205 putenv(var->varstr);
2207 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2213 static struct variable *set_vars_and_save_old(char **strings)
2216 struct variable *old = NULL;
2222 struct variable *var_p;
2223 struct variable **var_pp;
2226 eq = strchr(*s, '=');
2228 var_pp = get_ptr_to_local_var(*s, eq - *s);
2230 /* Remove variable from global linked list */
2232 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2233 *var_pp = var_p->next;
2234 /* Add it to returned list */
2238 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2249 static void reinit_unicode_for_hush(void)
2251 /* Unicode support should be activated even if LANG is set
2252 * _during_ shell execution, not only if it was set when
2253 * shell was started. Therefore, re-check LANG every time:
2255 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2256 || ENABLE_UNICODE_USING_LOCALE
2258 const char *s = get_local_var_value("LC_ALL");
2259 if (!s) s = get_local_var_value("LC_CTYPE");
2260 if (!s) s = get_local_var_value("LANG");
2266 * in_str support (strings, and "strings" read from files).
2269 #if ENABLE_HUSH_INTERACTIVE
2270 /* To test correct lineedit/interactive behavior, type from command line:
2276 * It excercises a lot of corner cases.
2278 static void cmdedit_update_prompt(void)
2280 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2281 G.PS1 = get_local_var_value("PS1");
2284 G.PS2 = get_local_var_value("PS2");
2291 static const char *setup_prompt_string(int promptmode)
2293 const char *prompt_str;
2294 debug_printf("setup_prompt_string %d ", promptmode);
2295 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2296 /* Set up the prompt */
2297 if (promptmode == 0) { /* PS1 */
2299 /* bash uses $PWD value, even if it is set by user.
2300 * It uses current dir only if PWD is unset.
2301 * We always use current dir. */
2302 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2307 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2308 debug_printf("prompt_str '%s'\n", prompt_str);
2311 static int get_user_input(struct in_str *i)
2314 const char *prompt_str;
2316 prompt_str = setup_prompt_string(i->promptmode);
2317 # if ENABLE_FEATURE_EDITING
2319 reinit_unicode_for_hush();
2320 if (G.flag_SIGINT) {
2321 /* There was ^C'ed, make it look prettier: */
2325 /* buglet: SIGINT will not make new prompt to appear _at once_,
2326 * only after <Enter>. (^C works immediately) */
2327 r = read_line_input(G.line_input_state, prompt_str,
2328 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2331 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2333 write(STDOUT_FILENO, "^C", 2);
2336 check_and_run_traps();
2337 if (r != 0 && !G.flag_SIGINT)
2339 /* ^C or SIGINT: repeat */
2340 G.last_exitcode = 128 + SIGINT;
2343 /* EOF/error detected */
2345 i->peek_buf[0] = r = EOF;
2348 i->p = G.user_input_buf;
2349 return (unsigned char)*i->p++;
2353 if (i->last_char == '\0' || i->last_char == '\n') {
2354 /* Why check_and_run_traps here? Try this interactively:
2355 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2356 * $ <[enter], repeatedly...>
2357 * Without check_and_run_traps, handler never runs.
2359 check_and_run_traps();
2360 fputs(prompt_str, stdout);
2363 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2365 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2366 * no ^C masking happens during fgetc, no special code for ^C:
2367 * it generates SIGINT as usual.
2369 check_and_run_traps();
2371 G.last_exitcode = 128 + SIGINT;
2378 /* This is the magic location that prints prompts
2379 * and gets data back from the user */
2380 static int fgetc_interactive(struct in_str *i)
2383 /* If it's interactive stdin, get new line. */
2384 if (G_interactive_fd && i->file == stdin) {
2385 /* Returns first char (or EOF), the rest is in i->p[] */
2386 ch = get_user_input(i);
2387 i->promptmode = 1; /* PS2 */
2389 /* Not stdin: script file, sourced file, etc */
2390 do ch = fgetc(i->file); while (ch == '\0');
2395 static inline int fgetc_interactive(struct in_str *i)
2398 do ch = fgetc(i->file); while (ch == '\0');
2401 #endif /* INTERACTIVE */
2403 static int i_getch(struct in_str *i)
2408 /* string-based in_str */
2409 ch = (unsigned char)*i->p;
2418 /* FILE-based in_str */
2420 #if ENABLE_FEATURE_EDITING
2421 /* This can be stdin, check line editing char[] buffer */
2422 if (i->p && *i->p != '\0') {
2423 ch = (unsigned char)*i->p++;
2427 /* peek_buf[] is an int array, not char. Can contain EOF. */
2428 ch = i->peek_buf[0];
2430 int ch2 = i->peek_buf[1];
2431 i->peek_buf[0] = ch2;
2432 if (ch2 == 0) /* very likely, avoid redundant write */
2438 ch = fgetc_interactive(i);
2440 debug_printf("file_get: got '%c' %d\n", ch, ch);
2445 static int i_peek(struct in_str *i)
2450 /* string-based in_str */
2451 /* Doesn't report EOF on NUL. None of the callers care. */
2452 return (unsigned char)*i->p;
2455 /* FILE-based in_str */
2457 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2458 /* This can be stdin, check line editing char[] buffer */
2459 if (i->p && *i->p != '\0')
2460 return (unsigned char)*i->p;
2462 /* peek_buf[] is an int array, not char. Can contain EOF. */
2463 ch = i->peek_buf[0];
2467 /* Need to get a new char */
2468 ch = fgetc_interactive(i);
2469 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2471 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2472 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2478 i->peek_buf[0] = ch;
2479 /*i->peek_buf[1] = 0; - already is */
2483 /* Only ever called if i_peek() was called, and did not return EOF.
2484 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2485 * not end-of-line. Therefore we never need to read a new editing line here.
2487 static int i_peek2(struct in_str *i)
2491 /* There are two cases when i->p[] buffer exists.
2492 * (1) it's a string in_str.
2493 * (2) It's a file, and we have a saved line editing buffer.
2494 * In both cases, we know that i->p[0] exists and not NUL, and
2495 * the peek2 result is in i->p[1].
2498 return (unsigned char)i->p[1];
2500 /* Now we know it is a file-based in_str. */
2502 /* peek_buf[] is an int array, not char. Can contain EOF. */
2503 /* Is there 2nd char? */
2504 ch = i->peek_buf[1];
2506 /* We did not read it yet, get it now */
2507 do ch = fgetc(i->file); while (ch == '\0');
2508 i->peek_buf[1] = ch;
2511 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2515 static void setup_file_in_str(struct in_str *i, FILE *f)
2517 memset(i, 0, sizeof(*i));
2518 /* i->promptmode = 0; - PS1 (memset did it) */
2523 static void setup_string_in_str(struct in_str *i, const char *s)
2525 memset(i, 0, sizeof(*i));
2526 /* i->promptmode = 0; - PS1 (memset did it) */
2527 /*i->file = NULL */;
2535 #define B_CHUNK (32 * sizeof(char*))
2537 static void o_reset_to_empty_unquoted(o_string *o)
2540 o->has_quoted_part = 0;
2545 static void o_free(o_string *o)
2548 memset(o, 0, sizeof(*o));
2551 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2556 static void o_grow_by(o_string *o, int len)
2558 if (o->length + len > o->maxlen) {
2559 o->maxlen += (2 * len) | (B_CHUNK-1);
2560 o->data = xrealloc(o->data, 1 + o->maxlen);
2564 static void o_addchr(o_string *o, int ch)
2566 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2567 if (o->length < o->maxlen) {
2568 /* likely. avoid o_grow_by() call */
2570 o->data[o->length] = ch;
2572 o->data[o->length] = '\0';
2580 /* Valid only if we know o_string is not empty */
2581 static void o_delchr(o_string *o)
2584 o->data[o->length] = '\0';
2588 static void o_addblock(o_string *o, const char *str, int len)
2591 memcpy(&o->data[o->length], str, len);
2593 o->data[o->length] = '\0';
2596 static void o_addstr(o_string *o, const char *str)
2598 o_addblock(o, str, strlen(str));
2602 static void nommu_addchr(o_string *o, int ch)
2608 # define nommu_addchr(o, str) ((void)0)
2611 static void o_addstr_with_NUL(o_string *o, const char *str)
2613 o_addblock(o, str, strlen(str) + 1);
2617 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2618 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2619 * Apparently, on unquoted $v bash still does globbing
2620 * ("v='*.txt'; echo $v" prints all .txt files),
2621 * but NOT brace expansion! Thus, there should be TWO independent
2622 * quoting mechanisms on $v expansion side: one protects
2623 * $v from brace expansion, and other additionally protects "$v" against globbing.
2624 * We have only second one.
2627 #if ENABLE_HUSH_BRACE_EXPANSION
2628 # define MAYBE_BRACES "{}"
2630 # define MAYBE_BRACES ""
2633 /* My analysis of quoting semantics tells me that state information
2634 * is associated with a destination, not a source.
2636 static void o_addqchr(o_string *o, int ch)
2639 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2644 o->data[o->length] = '\\';
2647 o->data[o->length] = ch;
2649 o->data[o->length] = '\0';
2652 static void o_addQchr(o_string *o, int ch)
2655 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2656 && strchr("*?[\\" MAYBE_BRACES, ch)
2659 o->data[o->length] = '\\';
2663 o->data[o->length] = ch;
2665 o->data[o->length] = '\0';
2668 static void o_addqblock(o_string *o, const char *str, int len)
2673 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2674 if (ordinary_cnt > len) /* paranoia */
2676 o_addblock(o, str, ordinary_cnt);
2677 if (ordinary_cnt == len)
2678 return; /* NUL is already added by o_addblock */
2679 str += ordinary_cnt;
2680 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2684 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2686 o->data[o->length] = '\\';
2690 o->data[o->length] = ch;
2693 o->data[o->length] = '\0';
2696 static void o_addQblock(o_string *o, const char *str, int len)
2698 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2699 o_addblock(o, str, len);
2702 o_addqblock(o, str, len);
2705 static void o_addQstr(o_string *o, const char *str)
2707 o_addQblock(o, str, strlen(str));
2710 /* A special kind of o_string for $VAR and `cmd` expansion.
2711 * It contains char* list[] at the beginning, which is grown in 16 element
2712 * increments. Actual string data starts at the next multiple of 16 * (char*).
2713 * list[i] contains an INDEX (int!) into this string data.
2714 * It means that if list[] needs to grow, data needs to be moved higher up
2715 * but list[i]'s need not be modified.
2716 * NB: remembering how many list[i]'s you have there is crucial.
2717 * o_finalize_list() operation post-processes this structure - calculates
2718 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2720 #if DEBUG_EXPAND || DEBUG_GLOB
2721 static void debug_print_list(const char *prefix, o_string *o, int n)
2723 char **list = (char**)o->data;
2724 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2728 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2729 prefix, list, n, string_start, o->length, o->maxlen,
2730 !!(o->o_expflags & EXP_FLAG_GLOB),
2732 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2735 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2736 o->data + (int)(uintptr_t)list[i] + string_start,
2737 o->data + (int)(uintptr_t)list[i] + string_start);
2741 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2743 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2747 # define debug_print_list(prefix, o, n) ((void)0)
2750 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2751 * in list[n] so that it points past last stored byte so far.
2752 * It returns n+1. */
2753 static int o_save_ptr_helper(o_string *o, int n)
2755 char **list = (char**)o->data;
2759 if (!o->has_empty_slot) {
2760 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2761 string_len = o->length - string_start;
2762 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2763 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2764 /* list[n] points to string_start, make space for 16 more pointers */
2765 o->maxlen += 0x10 * sizeof(list[0]);
2766 o->data = xrealloc(o->data, o->maxlen + 1);
2767 list = (char**)o->data;
2768 memmove(list + n + 0x10, list + n, string_len);
2769 o->length += 0x10 * sizeof(list[0]);
2771 debug_printf_list("list[%d]=%d string_start=%d\n",
2772 n, string_len, string_start);
2775 /* We have empty slot at list[n], reuse without growth */
2776 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2777 string_len = o->length - string_start;
2778 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2779 n, string_len, string_start);
2780 o->has_empty_slot = 0;
2782 o->has_quoted_part = 0;
2783 list[n] = (char*)(uintptr_t)string_len;
2787 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2788 static int o_get_last_ptr(o_string *o, int n)
2790 char **list = (char**)o->data;
2791 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2793 return ((int)(uintptr_t)list[n-1]) + string_start;
2796 #if ENABLE_HUSH_BRACE_EXPANSION
2797 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2798 * first, it processes even {a} (no commas), second,
2799 * I didn't manage to make it return strings when they don't match
2800 * existing files. Need to re-implement it.
2804 static int glob_needed(const char *s)
2813 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2819 /* Return pointer to next closing brace or to comma */
2820 static const char *next_brace_sub(const char *cp)
2824 while (*cp != '\0') {
2831 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2837 return *cp != '\0' ? cp : NULL;
2839 /* Recursive brace globber. Note: may garble pattern[]. */
2840 static int glob_brace(char *pattern, o_string *o, int n)
2842 char *new_pattern_buf;
2849 debug_printf_glob("glob_brace('%s')\n", pattern);
2855 if (*begin == '{') {
2856 /* Find the first sub-pattern and at the same time
2857 * find the rest after the closing brace */
2858 next = next_brace_sub(begin);
2860 /* An illegal expression */
2864 /* "{abc}" with no commas - illegal
2865 * brace expr, disregard and skip it */
2871 if (*begin == '\\' && begin[1] != '\0')
2875 debug_printf_glob("begin:%s\n", begin);
2876 debug_printf_glob("next:%s\n", next);
2878 /* Now find the end of the whole brace expression */
2880 while (*rest != '}') {
2881 rest = next_brace_sub(rest);
2883 /* An illegal expression */
2886 debug_printf_glob("rest:%s\n", rest);
2888 rest_len = strlen(++rest) + 1;
2890 /* We are sure the brace expression is well-formed */
2892 /* Allocate working buffer large enough for our work */
2893 new_pattern_buf = xmalloc(strlen(pattern));
2895 /* We have a brace expression. BEGIN points to the opening {,
2896 * NEXT points past the terminator of the first element, and REST
2897 * points past the final }. We will accumulate result names from
2898 * recursive runs for each brace alternative in the buffer using
2903 /* Construct the new glob expression */
2906 mempcpy(new_pattern_buf,
2907 /* We know the prefix for all sub-patterns */
2908 pattern, begin - pattern),
2912 /* Note: glob_brace() may garble new_pattern_buf[].
2913 * That's why we re-copy prefix every time (1st memcpy above).
2915 n = glob_brace(new_pattern_buf, o, n);
2917 /* We saw the last entry */
2921 next = next_brace_sub(next);
2923 free(new_pattern_buf);
2931 memset(&globdata, 0, sizeof(globdata));
2932 gr = glob(pattern, 0, NULL, &globdata);
2933 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2935 if (gr == GLOB_NOMATCH) {
2936 globfree(&globdata);
2937 /* NB: garbles parameter */
2938 unbackslash(pattern);
2939 o_addstr_with_NUL(o, pattern);
2940 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2941 return o_save_ptr_helper(o, n);
2943 if (gr == GLOB_NOSPACE)
2944 bb_error_msg_and_die(bb_msg_memory_exhausted);
2945 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2946 * but we didn't specify it. Paranoia again. */
2947 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2949 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2950 char **argv = globdata.gl_pathv;
2952 o_addstr_with_NUL(o, *argv);
2953 n = o_save_ptr_helper(o, n);
2959 globfree(&globdata);
2963 /* Performs globbing on last list[],
2964 * saving each result as a new list[].
2966 static int perform_glob(o_string *o, int n)
2968 char *pattern, *copy;
2970 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2972 return o_save_ptr_helper(o, n);
2973 pattern = o->data + o_get_last_ptr(o, n);
2974 debug_printf_glob("glob pattern '%s'\n", pattern);
2975 if (!glob_needed(pattern)) {
2976 /* unbackslash last string in o in place, fix length */
2977 o->length = unbackslash(pattern) - o->data;
2978 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2979 return o_save_ptr_helper(o, n);
2982 copy = xstrdup(pattern);
2983 /* "forget" pattern in o */
2984 o->length = pattern - o->data;
2985 n = glob_brace(copy, o, n);
2988 debug_print_list("perform_glob returning", o, n);
2992 #else /* !HUSH_BRACE_EXPANSION */
2995 static int glob_needed(const char *s)
3004 if (*s == '*' || *s == '[' || *s == '?')
3010 /* Performs globbing on last list[],
3011 * saving each result as a new list[].
3013 static int perform_glob(o_string *o, int n)
3019 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3021 return o_save_ptr_helper(o, n);
3022 pattern = o->data + o_get_last_ptr(o, n);
3023 debug_printf_glob("glob pattern '%s'\n", pattern);
3024 if (!glob_needed(pattern)) {
3026 /* unbackslash last string in o in place, fix length */
3027 o->length = unbackslash(pattern) - o->data;
3028 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3029 return o_save_ptr_helper(o, n);
3032 memset(&globdata, 0, sizeof(globdata));
3033 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3034 * If we glob "*.\*" and don't find anything, we need
3035 * to fall back to using literal "*.*", but GLOB_NOCHECK
3036 * will return "*.\*"!
3038 gr = glob(pattern, 0, NULL, &globdata);
3039 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3041 if (gr == GLOB_NOMATCH) {
3042 globfree(&globdata);
3045 if (gr == GLOB_NOSPACE)
3046 bb_error_msg_and_die(bb_msg_memory_exhausted);
3047 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3048 * but we didn't specify it. Paranoia again. */
3049 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3051 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3052 char **argv = globdata.gl_pathv;
3053 /* "forget" pattern in o */
3054 o->length = pattern - o->data;
3056 o_addstr_with_NUL(o, *argv);
3057 n = o_save_ptr_helper(o, n);
3063 globfree(&globdata);
3065 debug_print_list("perform_glob returning", o, n);
3069 #endif /* !HUSH_BRACE_EXPANSION */
3071 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3072 * Otherwise, just finish current list[] and start new */
3073 static int o_save_ptr(o_string *o, int n)
3075 if (o->o_expflags & EXP_FLAG_GLOB) {
3076 /* If o->has_empty_slot, list[n] was already globbed
3077 * (if it was requested back then when it was filled)
3078 * so don't do that again! */
3079 if (!o->has_empty_slot)
3080 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3082 return o_save_ptr_helper(o, n);
3085 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3086 static char **o_finalize_list(o_string *o, int n)
3091 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3093 debug_print_list("finalized", o, n);
3094 debug_printf_expand("finalized n:%d\n", n);
3095 list = (char**)o->data;
3096 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3100 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3105 static void free_pipe_list(struct pipe *pi);
3107 /* Returns pi->next - next pipe in the list */
3108 static struct pipe *free_pipe(struct pipe *pi)
3113 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3114 for (i = 0; i < pi->num_cmds; i++) {
3115 struct command *command;
3116 struct redir_struct *r, *rnext;
3118 command = &pi->cmds[i];
3119 debug_printf_clean(" command %d:\n", i);
3120 if (command->argv) {
3124 for (a = 0, p = command->argv; *p; a++, p++) {
3125 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3128 free_strings(command->argv);
3129 //command->argv = NULL;
3131 /* not "else if": on syntax error, we may have both! */
3132 if (command->group) {
3133 debug_printf_clean(" begin group (cmd_type:%d)\n",
3135 free_pipe_list(command->group);
3136 debug_printf_clean(" end group\n");
3137 //command->group = NULL;
3139 /* else is crucial here.
3140 * If group != NULL, child_func is meaningless */
3141 #if ENABLE_HUSH_FUNCTIONS
3142 else if (command->child_func) {
3143 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3144 command->child_func->parent_cmd = NULL;
3148 free(command->group_as_string);
3149 //command->group_as_string = NULL;
3151 for (r = command->redirects; r; r = rnext) {
3152 debug_printf_clean(" redirect %d%s",
3153 r->rd_fd, redir_table[r->rd_type].descrip);
3154 /* guard against the case >$FOO, where foo is unset or blank */
3155 if (r->rd_filename) {
3156 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3157 free(r->rd_filename);
3158 //r->rd_filename = NULL;
3160 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3164 //command->redirects = NULL;
3166 free(pi->cmds); /* children are an array, they get freed all at once */
3170 //pi->cmdtext = NULL;
3178 static void free_pipe_list(struct pipe *pi)
3182 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3184 debug_printf_clean("pipe followup code %d\n", pi->followup);
3190 /*** Parsing routines ***/
3192 #ifndef debug_print_tree
3193 static void debug_print_tree(struct pipe *pi, int lvl)
3195 static const char *const PIPE[] = {
3201 static const char *RES[] = {
3202 [RES_NONE ] = "NONE" ,
3205 [RES_THEN ] = "THEN" ,
3206 [RES_ELIF ] = "ELIF" ,
3207 [RES_ELSE ] = "ELSE" ,
3210 # if ENABLE_HUSH_LOOPS
3211 [RES_FOR ] = "FOR" ,
3212 [RES_WHILE] = "WHILE",
3213 [RES_UNTIL] = "UNTIL",
3215 [RES_DONE ] = "DONE" ,
3217 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3220 # if ENABLE_HUSH_CASE
3221 [RES_CASE ] = "CASE" ,
3222 [RES_CASE_IN ] = "CASE_IN" ,
3223 [RES_MATCH] = "MATCH",
3224 [RES_CASE_BODY] = "CASE_BODY",
3225 [RES_ESAC ] = "ESAC" ,
3227 [RES_XXXX ] = "XXXX" ,
3228 [RES_SNTX ] = "SNTX" ,
3230 static const char *const CMDTYPE[] = {
3234 # if ENABLE_HUSH_FUNCTIONS
3243 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3244 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3246 while (prn < pi->num_cmds) {
3247 struct command *command = &pi->cmds[prn];
3248 char **argv = command->argv;
3250 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3252 command->assignment_cnt);
3253 if (command->group) {
3254 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3255 CMDTYPE[command->cmd_type],
3258 , " group_as_string:", command->group_as_string
3263 debug_print_tree(command->group, lvl+1);
3267 if (argv) while (*argv) {
3268 fdprintf(2, " '%s'", *argv);
3278 #endif /* debug_print_tree */
3280 static struct pipe *new_pipe(void)
3283 pi = xzalloc(sizeof(struct pipe));
3284 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3288 /* Command (member of a pipe) is complete, or we start a new pipe
3289 * if ctx->command is NULL.
3290 * No errors possible here.
3292 static int done_command(struct parse_context *ctx)
3294 /* The command is really already in the pipe structure, so
3295 * advance the pipe counter and make a new, null command. */
3296 struct pipe *pi = ctx->pipe;
3297 struct command *command = ctx->command;
3299 #if 0 /* Instead we emit error message at run time */
3300 if (ctx->pending_redirect) {
3301 /* For example, "cmd >" (no filename to redirect to) */
3302 die_if_script("syntax error: %s", "invalid redirect");
3303 ctx->pending_redirect = NULL;
3308 if (IS_NULL_CMD(command)) {
3309 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3313 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3314 //debug_print_tree(ctx->list_head, 20);
3316 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3319 /* Only real trickiness here is that the uncommitted
3320 * command structure is not counted in pi->num_cmds. */
3321 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3322 ctx->command = command = &pi->cmds[pi->num_cmds];
3324 memset(command, 0, sizeof(*command));
3325 return pi->num_cmds; /* used only for 0/nonzero check */
3328 static void done_pipe(struct parse_context *ctx, pipe_style type)
3332 debug_printf_parse("done_pipe entered, followup %d\n", type);
3333 /* Close previous command */
3334 not_null = done_command(ctx);
3335 ctx->pipe->followup = type;
3337 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3338 ctx->ctx_inverted = 0;
3339 ctx->pipe->res_word = ctx->ctx_res_w;
3342 /* Without this check, even just <enter> on command line generates
3343 * tree of three NOPs (!). Which is harmless but annoying.
3344 * IOW: it is safe to do it unconditionally. */
3347 || ctx->ctx_res_w == RES_FI
3349 #if ENABLE_HUSH_LOOPS
3350 || ctx->ctx_res_w == RES_DONE
3351 || ctx->ctx_res_w == RES_FOR
3352 || ctx->ctx_res_w == RES_IN
3354 #if ENABLE_HUSH_CASE
3355 || ctx->ctx_res_w == RES_ESAC
3359 debug_printf_parse("done_pipe: adding new pipe: "
3360 "not_null:%d ctx->ctx_res_w:%d\n",
3361 not_null, ctx->ctx_res_w);
3363 ctx->pipe->next = new_p;
3365 /* RES_THEN, RES_DO etc are "sticky" -
3366 * they remain set for pipes inside if/while.
3367 * This is used to control execution.
3368 * RES_FOR and RES_IN are NOT sticky (needed to support
3369 * cases where variable or value happens to match a keyword):
3371 #if ENABLE_HUSH_LOOPS
3372 if (ctx->ctx_res_w == RES_FOR
3373 || ctx->ctx_res_w == RES_IN)
3374 ctx->ctx_res_w = RES_NONE;
3376 #if ENABLE_HUSH_CASE
3377 if (ctx->ctx_res_w == RES_MATCH)
3378 ctx->ctx_res_w = RES_CASE_BODY;
3379 if (ctx->ctx_res_w == RES_CASE)
3380 ctx->ctx_res_w = RES_CASE_IN;
3382 ctx->command = NULL; /* trick done_command below */
3383 /* Create the memory for command, roughly:
3384 * ctx->pipe->cmds = new struct command;
3385 * ctx->command = &ctx->pipe->cmds[0];
3388 //debug_print_tree(ctx->list_head, 10);
3390 debug_printf_parse("done_pipe return\n");
3393 static void initialize_context(struct parse_context *ctx)
3395 memset(ctx, 0, sizeof(*ctx));
3396 ctx->pipe = ctx->list_head = new_pipe();
3397 /* Create the memory for command, roughly:
3398 * ctx->pipe->cmds = new struct command;
3399 * ctx->command = &ctx->pipe->cmds[0];
3404 /* If a reserved word is found and processed, parse context is modified
3405 * and 1 is returned.
3408 struct reserved_combo {
3411 unsigned char assignment_flag;
3415 FLAG_END = (1 << RES_NONE ),
3417 FLAG_IF = (1 << RES_IF ),
3418 FLAG_THEN = (1 << RES_THEN ),
3419 FLAG_ELIF = (1 << RES_ELIF ),
3420 FLAG_ELSE = (1 << RES_ELSE ),
3421 FLAG_FI = (1 << RES_FI ),
3423 # if ENABLE_HUSH_LOOPS
3424 FLAG_FOR = (1 << RES_FOR ),
3425 FLAG_WHILE = (1 << RES_WHILE),
3426 FLAG_UNTIL = (1 << RES_UNTIL),
3427 FLAG_DO = (1 << RES_DO ),
3428 FLAG_DONE = (1 << RES_DONE ),
3429 FLAG_IN = (1 << RES_IN ),
3431 # if ENABLE_HUSH_CASE
3432 FLAG_MATCH = (1 << RES_MATCH),
3433 FLAG_ESAC = (1 << RES_ESAC ),
3435 FLAG_START = (1 << RES_XXXX ),
3438 static const struct reserved_combo* match_reserved_word(o_string *word)
3440 /* Mostly a list of accepted follow-up reserved words.
3441 * FLAG_END means we are done with the sequence, and are ready
3442 * to turn the compound list into a command.
3443 * FLAG_START means the word must start a new compound list.
3445 static const struct reserved_combo reserved_list[] = {
3447 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3448 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3449 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3450 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3451 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3452 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3454 # if ENABLE_HUSH_LOOPS
3455 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3456 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3457 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3458 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3459 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3460 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3462 # if ENABLE_HUSH_CASE
3463 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3464 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3467 const struct reserved_combo *r;
3469 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3470 if (strcmp(word->data, r->literal) == 0)
3475 /* Return 0: not a keyword, 1: keyword
3477 static int reserved_word(o_string *word, struct parse_context *ctx)
3479 # if ENABLE_HUSH_CASE
3480 static const struct reserved_combo reserved_match = {
3481 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3484 const struct reserved_combo *r;
3486 if (word->has_quoted_part)
3488 r = match_reserved_word(word);
3492 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3493 # if ENABLE_HUSH_CASE
3494 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3495 /* "case word IN ..." - IN part starts first MATCH part */
3496 r = &reserved_match;
3499 if (r->flag == 0) { /* '!' */
3500 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3501 syntax_error("! ! command");
3502 ctx->ctx_res_w = RES_SNTX;
3504 ctx->ctx_inverted = 1;
3507 if (r->flag & FLAG_START) {
3508 struct parse_context *old;
3510 old = xmalloc(sizeof(*old));
3511 debug_printf_parse("push stack %p\n", old);
3512 *old = *ctx; /* physical copy */
3513 initialize_context(ctx);
3515 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3516 syntax_error_at(word->data);
3517 ctx->ctx_res_w = RES_SNTX;
3520 /* "{...} fi" is ok. "{...} if" is not
3522 * if { echo foo; } then { echo bar; } fi */
3523 if (ctx->command->group)
3524 done_pipe(ctx, PIPE_SEQ);
3527 ctx->ctx_res_w = r->res;
3528 ctx->old_flag = r->flag;
3529 word->o_assignment = r->assignment_flag;
3530 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3532 if (ctx->old_flag & FLAG_END) {
3533 struct parse_context *old;
3535 done_pipe(ctx, PIPE_SEQ);
3536 debug_printf_parse("pop stack %p\n", ctx->stack);
3538 old->command->group = ctx->list_head;
3539 old->command->cmd_type = CMD_NORMAL;
3541 /* At this point, the compound command's string is in
3542 * ctx->as_string... except for the leading keyword!
3543 * Consider this example: "echo a | if true; then echo a; fi"
3544 * ctx->as_string will contain "true; then echo a; fi",
3545 * with "if " remaining in old->as_string!
3549 int len = old->as_string.length;
3550 /* Concatenate halves */
3551 o_addstr(&old->as_string, ctx->as_string.data);
3552 o_free_unsafe(&ctx->as_string);
3553 /* Find where leading keyword starts in first half */
3554 str = old->as_string.data + len;
3555 if (str > old->as_string.data)
3556 str--; /* skip whitespace after keyword */
3557 while (str > old->as_string.data && isalpha(str[-1]))
3559 /* Ugh, we're done with this horrid hack */
3560 old->command->group_as_string = xstrdup(str);
3561 debug_printf_parse("pop, remembering as:'%s'\n",
3562 old->command->group_as_string);
3565 *ctx = *old; /* physical copy */
3570 #endif /* HAS_KEYWORDS */
3572 /* Word is complete, look at it and update parsing context.
3573 * Normal return is 0. Syntax errors return 1.
3574 * Note: on return, word is reset, but not o_free'd!
3576 static int done_word(o_string *word, struct parse_context *ctx)
3578 struct command *command = ctx->command;
3580 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3581 if (word->length == 0 && !word->has_quoted_part) {
3582 debug_printf_parse("done_word return 0: true null, ignored\n");
3586 if (ctx->pending_redirect) {
3587 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3588 * only if run as "bash", not "sh" */
3589 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3591 * ...the word that follows the redirection operator
3592 * shall be subjected to tilde expansion, parameter expansion,
3593 * command substitution, arithmetic expansion, and quote
3594 * removal. Pathname expansion shall not be performed
3595 * on the word by a non-interactive shell; an interactive
3596 * shell may perform it, but shall do so only when
3597 * the expansion would result in one word."
3599 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3600 /* Cater for >\file case:
3601 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3602 * Same with heredocs:
3603 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3605 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3606 unbackslash(ctx->pending_redirect->rd_filename);
3607 /* Is it <<"HEREDOC"? */
3608 if (word->has_quoted_part) {
3609 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3612 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3613 ctx->pending_redirect = NULL;
3616 # if ENABLE_HUSH_CASE
3617 if (ctx->ctx_dsemicolon
3618 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3620 /* already done when ctx_dsemicolon was set to 1: */
3621 /* ctx->ctx_res_w = RES_MATCH; */
3622 ctx->ctx_dsemicolon = 0;
3625 if (!command->argv /* if it's the first word... */
3626 # if ENABLE_HUSH_LOOPS
3627 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3628 && ctx->ctx_res_w != RES_IN
3630 # if ENABLE_HUSH_CASE
3631 && ctx->ctx_res_w != RES_CASE
3634 int reserved = reserved_word(word, ctx);
3635 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3637 o_reset_to_empty_unquoted(word);
3638 debug_printf_parse("done_word return %d\n",
3639 (ctx->ctx_res_w == RES_SNTX));
3640 return (ctx->ctx_res_w == RES_SNTX);
3642 # if ENABLE_HUSH_BASH_COMPAT
3643 if (strcmp(word->data, "[[") == 0) {
3644 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3650 if (command->group) {
3651 /* "{ echo foo; } echo bar" - bad */
3652 syntax_error_at(word->data);
3653 debug_printf_parse("done_word return 1: syntax error, "
3654 "groups and arglists don't mix\n");
3658 /* If this word wasn't an assignment, next ones definitely
3659 * can't be assignments. Even if they look like ones. */
3660 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3661 && word->o_assignment != WORD_IS_KEYWORD
3663 word->o_assignment = NOT_ASSIGNMENT;
3665 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3666 command->assignment_cnt++;
3667 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3669 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3670 word->o_assignment = MAYBE_ASSIGNMENT;
3672 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3674 if (word->has_quoted_part
3675 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3676 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3677 /* (otherwise it's known to be not empty and is already safe) */
3679 /* exclude "$@" - it can expand to no word despite "" */
3680 char *p = word->data;
3681 while (p[0] == SPECIAL_VAR_SYMBOL
3682 && (p[1] & 0x7f) == '@'
3683 && p[2] == SPECIAL_VAR_SYMBOL
3688 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3689 debug_print_strings("word appended to argv", command->argv);
3692 #if ENABLE_HUSH_LOOPS
3693 if (ctx->ctx_res_w == RES_FOR) {
3694 if (word->has_quoted_part
3695 || !is_well_formed_var_name(command->argv[0], '\0')
3697 /* bash says just "not a valid identifier" */
3698 syntax_error("not a valid identifier in for");
3701 /* Force FOR to have just one word (variable name) */
3702 /* NB: basically, this makes hush see "for v in ..."
3703 * syntax as if it is "for v; in ...". FOR and IN become
3704 * two pipe structs in parse tree. */
3705 done_pipe(ctx, PIPE_SEQ);
3708 #if ENABLE_HUSH_CASE
3709 /* Force CASE to have just one word */
3710 if (ctx->ctx_res_w == RES_CASE) {
3711 done_pipe(ctx, PIPE_SEQ);
3715 o_reset_to_empty_unquoted(word);
3717 debug_printf_parse("done_word return 0\n");
3722 /* Peek ahead in the input to find out if we have a "&n" construct,
3723 * as in "2>&1", that represents duplicating a file descriptor.
3725 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3726 * REDIRFD_SYNTAX_ERR if syntax error,
3727 * REDIRFD_TO_FILE if no & was seen,
3728 * or the number found.
3731 #define parse_redir_right_fd(as_string, input) \
3732 parse_redir_right_fd(input)
3734 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3740 return REDIRFD_TO_FILE;
3742 ch = i_getch(input); /* get the & */
3743 nommu_addchr(as_string, ch);
3746 ch = i_getch(input);
3747 nommu_addchr(as_string, ch);
3748 return REDIRFD_CLOSE;
3752 while (ch != EOF && isdigit(ch)) {
3753 d = d*10 + (ch-'0');
3755 ch = i_getch(input);
3756 nommu_addchr(as_string, ch);
3761 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3763 bb_error_msg("ambiguous redirect");
3764 return REDIRFD_SYNTAX_ERR;
3767 /* Return code is 0 normal, 1 if a syntax error is detected
3769 static int parse_redirect(struct parse_context *ctx,
3772 struct in_str *input)
3774 struct command *command = ctx->command;
3775 struct redir_struct *redir;
3776 struct redir_struct **redirp;
3779 dup_num = REDIRFD_TO_FILE;
3780 if (style != REDIRECT_HEREDOC) {
3781 /* Check for a '>&1' type redirect */
3782 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3783 if (dup_num == REDIRFD_SYNTAX_ERR)
3786 int ch = i_peek(input);
3787 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3788 if (dup_num) { /* <<-... */
3789 ch = i_getch(input);
3790 nommu_addchr(&ctx->as_string, ch);
3795 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3796 int ch = i_peek(input);
3798 /* >|FILE redirect ("clobbering" >).
3799 * Since we do not support "set -o noclobber" yet,
3800 * >| and > are the same for now. Just eat |.
3802 ch = i_getch(input);
3803 nommu_addchr(&ctx->as_string, ch);
3807 /* Create a new redir_struct and append it to the linked list */
3808 redirp = &command->redirects;
3809 while ((redir = *redirp) != NULL) {
3810 redirp = &(redir->next);
3812 *redirp = redir = xzalloc(sizeof(*redir));
3813 /* redir->next = NULL; */
3814 /* redir->rd_filename = NULL; */
3815 redir->rd_type = style;
3816 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3818 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3819 redir_table[style].descrip);
3821 redir->rd_dup = dup_num;
3822 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3823 /* Erik had a check here that the file descriptor in question
3824 * is legit; I postpone that to "run time"
3825 * A "-" representation of "close me" shows up as a -3 here */
3826 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3827 redir->rd_fd, redir->rd_dup);
3829 #if 0 /* Instead we emit error message at run time */
3830 if (ctx->pending_redirect) {
3831 /* For example, "cmd > <file" */
3832 die_if_script("syntax error: %s", "invalid redirect");
3835 /* Set ctx->pending_redirect, so we know what to do at the
3836 * end of the next parsed word. */
3837 ctx->pending_redirect = redir;
3842 /* If a redirect is immediately preceded by a number, that number is
3843 * supposed to tell which file descriptor to redirect. This routine
3844 * looks for such preceding numbers. In an ideal world this routine
3845 * needs to handle all the following classes of redirects...
3846 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3847 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3848 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3849 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3851 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3853 * ... If n is quoted, the number shall not be recognized as part of
3854 * the redirection expression. For example:
3856 * writes the character 2 into file a"
3857 * We are getting it right by setting ->has_quoted_part on any \<char>
3859 * A -1 return means no valid number was found,
3860 * the caller should use the appropriate default for this redirection.
3862 static int redirect_opt_num(o_string *o)
3866 if (o->data == NULL)
3868 num = bb_strtou(o->data, NULL, 10);
3869 if (errno || num < 0)
3871 o_reset_to_empty_unquoted(o);
3876 #define fetch_till_str(as_string, input, word, skip_tabs) \
3877 fetch_till_str(input, word, skip_tabs)
3879 static char *fetch_till_str(o_string *as_string,
3880 struct in_str *input,
3884 o_string heredoc = NULL_O_STRING;
3886 int prev = 0; /* not \ */
3892 ch = i_getch(input);
3894 nommu_addchr(as_string, ch);
3895 if ((ch == '\n' || ch == EOF)
3896 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3898 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3899 heredoc.data[past_EOL] = '\0';
3900 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3901 return heredoc.data;
3903 while (ch == '\n') {
3904 o_addchr(&heredoc, ch);
3907 past_EOL = heredoc.length;
3909 ch = i_getch(input);
3911 nommu_addchr(as_string, ch);
3912 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3916 o_free_unsafe(&heredoc);
3919 o_addchr(&heredoc, ch);
3920 nommu_addchr(as_string, ch);
3921 if (prev == '\\' && ch == '\\')
3922 /* Correctly handle foo\\<eol> (not a line cont.) */
3923 prev = 0; /* not \ */
3929 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3930 * and load them all. There should be exactly heredoc_cnt of them.
3932 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3934 struct pipe *pi = ctx->list_head;
3936 while (pi && heredoc_cnt) {
3938 struct command *cmd = pi->cmds;
3940 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3942 cmd->argv ? cmd->argv[0] : "NONE");
3943 for (i = 0; i < pi->num_cmds; i++) {
3944 struct redir_struct *redir = cmd->redirects;
3946 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3947 i, cmd->argv ? cmd->argv[0] : "NONE");
3949 if (redir->rd_type == REDIRECT_HEREDOC) {
3952 redir->rd_type = REDIRECT_HEREDOC2;
3953 /* redir->rd_dup is (ab)used to indicate <<- */
3954 p = fetch_till_str(&ctx->as_string, input,
3955 redir->rd_filename, redir->rd_dup);
3957 syntax_error("unexpected EOF in here document");
3960 free(redir->rd_filename);
3961 redir->rd_filename = p;
3964 redir = redir->next;
3971 /* Should be 0. If it isn't, it's a parse error */
3973 bb_error_msg_and_die("heredoc BUG 2");
3979 static int run_list(struct pipe *pi);
3981 #define parse_stream(pstring, input, end_trigger) \
3982 parse_stream(input, end_trigger)
3984 static struct pipe *parse_stream(char **pstring,
3985 struct in_str *input,
3989 #if !ENABLE_HUSH_FUNCTIONS
3990 #define parse_group(dest, ctx, input, ch) \
3991 parse_group(ctx, input, ch)
3993 static int parse_group(o_string *dest, struct parse_context *ctx,
3994 struct in_str *input, int ch)
3996 /* dest contains characters seen prior to ( or {.
3997 * Typically it's empty, but for function defs,
3998 * it contains function name (without '()'). */
3999 struct pipe *pipe_list;
4001 struct command *command = ctx->command;
4003 debug_printf_parse("parse_group entered\n");
4004 #if ENABLE_HUSH_FUNCTIONS
4005 if (ch == '(' && !dest->has_quoted_part) {
4007 if (done_word(dest, ctx))
4010 goto skip; /* (... */
4011 if (command->argv[1]) { /* word word ... (... */
4012 syntax_error_unexpected_ch('(');
4015 /* it is "word(..." or "word (..." */
4017 ch = i_getch(input);
4018 while (ch == ' ' || ch == '\t');
4020 syntax_error_unexpected_ch(ch);
4023 nommu_addchr(&ctx->as_string, ch);
4025 ch = i_getch(input);
4026 while (ch == ' ' || ch == '\t' || ch == '\n');
4028 syntax_error_unexpected_ch(ch);
4031 nommu_addchr(&ctx->as_string, ch);
4032 command->cmd_type = CMD_FUNCDEF;
4037 #if 0 /* Prevented by caller */
4038 if (command->argv /* word [word]{... */
4039 || dest->length /* word{... */
4040 || dest->has_quoted_part /* ""{... */
4043 debug_printf_parse("parse_group return 1: "
4044 "syntax error, groups and arglists don't mix\n");
4049 #if ENABLE_HUSH_FUNCTIONS
4055 command->cmd_type = CMD_SUBSHELL;
4057 /* bash does not allow "{echo...", requires whitespace */
4059 if (ch != ' ' && ch != '\t' && ch != '\n'
4060 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4062 syntax_error_unexpected_ch(ch);
4066 ch = i_getch(input);
4067 nommu_addchr(&ctx->as_string, ch);
4073 # define as_string NULL
4075 char *as_string = NULL;
4077 pipe_list = parse_stream(&as_string, input, endch);
4080 o_addstr(&ctx->as_string, as_string);
4082 /* empty ()/{} or parse error? */
4083 if (!pipe_list || pipe_list == ERR_PTR) {
4084 /* parse_stream already emitted error msg */
4087 debug_printf_parse("parse_group return 1: "
4088 "parse_stream returned %p\n", pipe_list);
4091 command->group = pipe_list;
4093 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4094 command->group_as_string = as_string;
4095 debug_printf_parse("end of group, remembering as:'%s'\n",
4096 command->group_as_string);
4100 debug_printf_parse("parse_group return 0\n");
4102 /* command remains "open", available for possible redirects */
4105 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4110 ch = i_getch(input);
4113 ch2 = i_peek(input);
4116 /* backslash+newline, skip it */
4121 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4129 ch2 = i_peek2(input);
4132 /* backslash+newline, skip it */
4138 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4139 /* Subroutines for copying $(...) and `...` things */
4140 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4142 static int add_till_single_quote(o_string *dest, struct in_str *input)
4145 int ch = i_getch(input);
4147 syntax_error_unterm_ch('\'');
4155 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4156 static int add_till_double_quote(o_string *dest, struct in_str *input)
4159 int ch = i_getch(input);
4161 syntax_error_unterm_ch('"');
4166 if (ch == '\\') { /* \x. Copy both chars. */
4168 ch = i_getch(input);
4172 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4177 //if (ch == '$') ...
4180 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4182 * "Within the backquoted style of command substitution, backslash
4183 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4184 * The search for the matching backquote shall be satisfied by the first
4185 * backquote found without a preceding backslash; during this search,
4186 * if a non-escaped backquote is encountered within a shell comment,
4187 * a here-document, an embedded command substitution of the $(command)
4188 * form, or a quoted string, undefined results occur. A single-quoted
4189 * or double-quoted string that begins, but does not end, within the
4190 * "`...`" sequence produces undefined results."
4192 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4194 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4197 int ch = i_getch(input);
4201 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4202 ch = i_getch(input);
4206 && (!in_dquote || ch != '"')
4208 o_addchr(dest, '\\');
4212 syntax_error_unterm_ch('`');
4218 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4219 * quoting and nested ()s.
4220 * "With the $(command) style of command substitution, all characters
4221 * following the open parenthesis to the matching closing parenthesis
4222 * constitute the command. Any valid shell script can be used for command,
4223 * except a script consisting solely of redirections which produces
4224 * unspecified results."
4226 * echo $(echo '(TEST)' BEST) (TEST) BEST
4227 * echo $(echo 'TEST)' BEST) TEST) BEST
4228 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4230 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4231 * can contain arbitrary constructs, just like $(cmd).
4232 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4233 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4235 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4236 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4239 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4240 # if ENABLE_HUSH_BASH_COMPAT
4241 char end_char2 = end_ch >> 8;
4243 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4246 ch = i_getch(input);
4248 syntax_error_unterm_ch(end_ch);
4251 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4254 /* we look for closing )) of $((EXPR)) */
4255 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4256 i_getch(input); /* eat second ')' */
4261 if (ch == '(' || ch == '{') {
4262 ch = (ch == '(' ? ')' : '}');
4263 if (!add_till_closing_bracket(dest, input, ch))
4269 if (!add_till_single_quote(dest, input))
4275 if (!add_till_double_quote(dest, input))
4281 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4287 /* \x. Copy verbatim. Important for \(, \) */
4288 ch = i_getch(input);
4290 syntax_error_unterm_ch(')');
4295 /* "backslash+newline", ignore both */
4296 o_delchr(dest); /* undo insertion of '\' */
4306 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4308 /* Return code: 0 for OK, 1 for syntax error */
4310 #define parse_dollar(as_string, dest, input, quote_mask) \
4311 parse_dollar(dest, input, quote_mask)
4312 #define as_string NULL
4314 static int parse_dollar(o_string *as_string,
4316 struct in_str *input, unsigned char quote_mask)
4318 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4320 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4322 ch = i_getch(input);
4323 nommu_addchr(as_string, ch);
4325 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4327 debug_printf_parse(": '%c'\n", ch);
4328 o_addchr(dest, ch | quote_mask);
4330 ch = i_peek_and_eat_bkslash_nl(input);
4331 if (!isalnum(ch) && ch != '_') {
4332 /* End of variable name reached */
4335 ch = i_getch(input);
4336 nommu_addchr(as_string, ch);
4338 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4339 } else if (isdigit(ch)) {
4341 ch = i_getch(input);
4342 nommu_addchr(as_string, ch);
4343 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4344 debug_printf_parse(": '%c'\n", ch);
4345 o_addchr(dest, ch | quote_mask);
4346 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4347 } else switch (ch) {
4349 case '!': /* last bg pid */
4350 case '?': /* last exit code */
4351 case '#': /* number of args */
4352 case '*': /* args */
4353 case '@': /* args */
4354 goto make_one_char_var;
4356 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4358 ch = i_getch(input); /* eat '{' */
4359 nommu_addchr(as_string, ch);
4361 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4362 /* It should be ${?}, or ${#var},
4363 * or even ${?+subst} - operator acting on a special variable,
4364 * or the beginning of variable name.
4367 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4370 syntax_error_unterm_str("${name}");
4371 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4374 nommu_addchr(as_string, ch);
4377 /* It's possible to just call add_till_closing_bracket() at this point.
4378 * However, this regresses some of our testsuite cases
4379 * which check invalid constructs like ${%}.
4380 * Oh well... let's check that the var name part is fine... */
4386 debug_printf_parse(": '%c'\n", ch);
4388 ch = i_getch(input);
4389 nommu_addchr(as_string, ch);
4393 if (!isalnum(ch) && ch != '_') {
4395 unsigned char last_ch;
4396 /* handle parameter expansions
4397 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4399 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4400 goto bad_dollar_syntax;
4402 /* Eat everything until closing '}' (or ':') */
4404 if (ENABLE_HUSH_BASH_COMPAT
4406 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4408 /* It's ${var:N[:M]} thing */
4409 end_ch = '}' * 0x100 + ':';
4411 if (ENABLE_HUSH_BASH_COMPAT
4414 /* It's ${var/[/]pattern[/repl]} thing */
4415 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4417 nommu_addchr(as_string, '/');
4420 end_ch = '}' * 0x100 + '/';
4426 #if ENABLE_HUSH_DOLLAR_OPS
4427 last_ch = add_till_closing_bracket(dest, input, end_ch);
4428 if (last_ch == 0) /* error? */
4431 #error Simple code to only allow ${var} is not implemented
4434 o_addstr(as_string, dest->data + pos);
4435 o_addchr(as_string, last_ch);
4438 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4439 /* close the first block: */
4440 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4441 /* while parsing N from ${var:N[:M]}
4442 * or pattern from ${var/[/]pattern[/repl]} */
4443 if ((end_ch & 0xff) == last_ch) {
4444 /* got ':' or '/'- parse the rest */
4449 if (end_ch == '}' * 0x100 + ':') {
4450 /* it's ${var:N} - emulate :999999999 */
4451 o_addstr(dest, "999999999");
4452 } /* else: it's ${var/[/]pattern} */
4457 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4460 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4464 ch = i_getch(input);
4465 nommu_addchr(as_string, ch);
4466 # if ENABLE_FEATURE_SH_MATH
4467 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4468 ch = i_getch(input);
4469 nommu_addchr(as_string, ch);
4470 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4471 o_addchr(dest, /*quote_mask |*/ '+');
4474 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4475 return 0; /* error */
4477 o_addstr(as_string, dest->data + pos);
4478 o_addchr(as_string, ')');
4479 o_addchr(as_string, ')');
4481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4485 # if ENABLE_HUSH_TICK
4486 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4487 o_addchr(dest, quote_mask | '`');
4490 if (!add_till_closing_bracket(dest, input, ')'))
4491 return 0; /* error */
4493 o_addstr(as_string, dest->data + pos);
4494 o_addchr(as_string, ')');
4496 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4502 ch = i_getch(input);
4503 nommu_addchr(as_string, ch);
4504 ch = i_peek_and_eat_bkslash_nl(input);
4505 if (isalnum(ch)) { /* it's $_name or $_123 */
4510 /* TODO: $_ and $-: */
4511 /* $_ Shell or shell script name; or last argument of last command
4512 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4513 * but in command's env, set to full pathname used to invoke it */
4514 /* $- Option flags set by set builtin or shell options (-i etc) */
4516 o_addQchr(dest, '$');
4518 debug_printf_parse("parse_dollar return 1 (ok)\n");
4524 # if ENABLE_HUSH_BASH_COMPAT
4525 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4526 encode_string(dest, input, dquote_end, process_bkslash)
4528 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4529 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4530 encode_string(dest, input, dquote_end)
4532 #define as_string NULL
4536 # if ENABLE_HUSH_BASH_COMPAT
4537 /* all parameters are needed, no macro tricks */
4539 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4540 encode_string(as_string, dest, input, dquote_end)
4543 static int encode_string(o_string *as_string,
4545 struct in_str *input,
4547 int process_bkslash)
4549 #if !ENABLE_HUSH_BASH_COMPAT
4550 const int process_bkslash = 1;
4556 ch = i_getch(input);
4558 nommu_addchr(as_string, ch);
4559 if (ch == dquote_end) { /* may be only '"' or EOF */
4560 debug_printf_parse("encode_string return 1 (ok)\n");
4563 /* note: can't move it above ch == dquote_end check! */
4565 syntax_error_unterm_ch('"');
4566 return 0; /* error */
4570 next = i_peek(input);
4572 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4573 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4574 if (process_bkslash && ch == '\\') {
4576 syntax_error("\\<eof>");
4580 * "The backslash retains its special meaning [in "..."]
4581 * only when followed by one of the following characters:
4582 * $, `, ", \, or <newline>. A double quote may be quoted
4583 * within double quotes by preceding it with a backslash."
4584 * NB: in (unquoted) heredoc, above does not apply to ",
4585 * therefore we check for it by "next == dquote_end" cond.
4587 if (next == dquote_end || strchr("$`\\\n", next)) {
4588 ch = i_getch(input); /* eat next */
4590 goto again; /* skip \<newline> */
4591 } /* else: ch remains == '\\', and we double it below: */
4592 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4593 nommu_addchr(as_string, ch);
4597 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4598 debug_printf_parse("encode_string return 0: "
4599 "parse_dollar returned 0 (error)\n");
4604 #if ENABLE_HUSH_TICK
4606 //unsigned pos = dest->length;
4607 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4608 o_addchr(dest, 0x80 | '`');
4609 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4610 return 0; /* error */
4611 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4612 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4616 o_addQchr(dest, ch);
4622 * Scan input until EOF or end_trigger char.
4623 * Return a list of pipes to execute, or NULL on EOF
4624 * or if end_trigger character is met.
4625 * On syntax error, exit if shell is not interactive,
4626 * reset parsing machinery and start parsing anew,
4627 * or return ERR_PTR.
4629 static struct pipe *parse_stream(char **pstring,
4630 struct in_str *input,
4633 struct parse_context ctx;
4634 o_string dest = NULL_O_STRING;
4637 /* Single-quote triggers a bypass of the main loop until its mate is
4638 * found. When recursing, quote state is passed in via dest->o_expflags.
4640 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4641 end_trigger ? end_trigger : 'X');
4644 /* If very first arg is "" or '', dest.data may end up NULL.
4645 * Preventing this: */
4646 o_addchr(&dest, '\0');
4649 /* We used to separate words on $IFS here. This was wrong.
4650 * $IFS is used only for word splitting when $var is expanded,
4651 * here we should use blank chars as separators, not $IFS
4654 if (MAYBE_ASSIGNMENT != 0)
4655 dest.o_assignment = MAYBE_ASSIGNMENT;
4656 initialize_context(&ctx);
4659 const char *is_blank;
4660 const char *is_special;
4664 redir_type redir_style;
4666 ch = i_getch(input);
4667 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4668 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4673 syntax_error_unterm_str("here document");
4676 if (end_trigger == ')') {
4677 syntax_error_unterm_ch('(');
4680 if (end_trigger == '}') {
4681 syntax_error_unterm_ch('{');
4685 if (done_word(&dest, &ctx)) {
4689 done_pipe(&ctx, PIPE_SEQ);
4691 /* If we got nothing... */
4692 /* (this makes bare "&" cmd a no-op.
4693 * bash says: "syntax error near unexpected token '&'") */
4694 if (pi->num_cmds == 0
4695 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4701 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4703 *pstring = ctx.as_string.data;
4705 o_free_unsafe(&ctx.as_string);
4708 debug_printf_parse("parse_stream return %p\n", pi);
4711 nommu_addchr(&ctx.as_string, ch);
4715 next = i_peek(input);
4717 is_special = "{}<>;&|()#'" /* special outside of "str" */
4718 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4719 /* Are { and } special here? */
4720 if (ctx.command->argv /* word [word]{... - non-special */
4721 || dest.length /* word{... - non-special */
4722 || dest.has_quoted_part /* ""{... - non-special */
4723 || (next != ';' /* }; - special */
4724 && next != ')' /* }) - special */
4725 && next != '(' /* {( - special */
4726 && next != '&' /* }& and }&& ... - special */
4727 && next != '|' /* }|| ... - special */
4728 && !strchr(defifs, next) /* {word - non-special */
4731 /* They are not special, skip "{}" */
4734 is_special = strchr(is_special, ch);
4735 is_blank = strchr(defifs, ch);
4737 if (!is_special && !is_blank) { /* ordinary char */
4739 o_addQchr(&dest, ch);
4740 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4741 || dest.o_assignment == WORD_IS_KEYWORD)
4743 && is_well_formed_var_name(dest.data, '=')
4745 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4746 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4752 if (done_word(&dest, &ctx)) {
4756 /* Is this a case when newline is simply ignored?
4758 * "cmd | <newline> cmd ..."
4759 * "case ... in <newline> word) ..."
4761 if (IS_NULL_CMD(ctx.command)
4762 && dest.length == 0 && !dest.has_quoted_part
4764 /* This newline can be ignored. But...
4765 * Without check #1, interactive shell
4766 * ignores even bare <newline>,
4767 * and shows the continuation prompt:
4768 * ps1_prompt$ <enter>
4769 * ps2> _ <=== wrong, should be ps1
4770 * Without check #2, "cmd & <newline>"
4771 * is similarly mistreated.
4772 * (BTW, this makes "cmd & cmd"
4773 * and "cmd && cmd" non-orthogonal.
4774 * Really, ask yourself, why
4775 * "cmd && <newline>" doesn't start
4776 * cmd but waits for more input?
4779 struct pipe *pi = ctx.list_head;
4780 if (pi->num_cmds != 0 /* check #1 */
4781 && pi->followup != PIPE_BG /* check #2 */
4786 /* Treat newline as a command separator. */
4787 done_pipe(&ctx, PIPE_SEQ);
4788 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4790 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4795 dest.o_assignment = MAYBE_ASSIGNMENT;
4796 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4798 /* note: if (is_blank) continue;
4799 * will still trigger for us */
4803 /* "cmd}" or "cmd }..." without semicolon or &:
4804 * } is an ordinary char in this case, even inside { cmd; }
4805 * Pathological example: { ""}; } should exec "}" cmd
4808 if (dest.length != 0 /* word} */
4809 || dest.has_quoted_part /* ""} */
4813 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4814 /* Generally, there should be semicolon: "cmd; }"
4815 * However, bash allows to omit it if "cmd" is
4816 * a group. Examples:
4819 * { echo 0 >&2 | { echo 1; } }
4820 * { while false; do :; done }
4821 * { case a in b) ;; esac }
4823 if (ctx.command->group)
4827 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4828 /* Can't be an end of {cmd}, skip the check */
4829 goto skip_end_trigger;
4830 /* else: } does terminate a group */
4833 if (end_trigger && end_trigger == ch
4834 && (ch != ';' || heredoc_cnt == 0)
4835 #if ENABLE_HUSH_CASE
4837 || ctx.ctx_res_w != RES_MATCH
4838 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4843 /* This is technically valid:
4844 * { cat <<HERE; }; echo Ok
4848 * but we don't support this.
4849 * We require heredoc to be in enclosing {}/(),
4852 syntax_error_unterm_str("here document");
4855 if (done_word(&dest, &ctx)) {
4858 done_pipe(&ctx, PIPE_SEQ);
4859 dest.o_assignment = MAYBE_ASSIGNMENT;
4860 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4861 /* Do we sit outside of any if's, loops or case's? */
4863 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4867 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4869 *pstring = ctx.as_string.data;
4871 o_free_unsafe(&ctx.as_string);
4874 debug_printf_parse("parse_stream return %p: "
4875 "end_trigger char found\n",
4877 return ctx.list_head;
4884 /* Catch <, > before deciding whether this word is
4885 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4888 redir_fd = redirect_opt_num(&dest);
4889 if (done_word(&dest, &ctx)) {
4892 redir_style = REDIRECT_OVERWRITE;
4894 redir_style = REDIRECT_APPEND;
4895 ch = i_getch(input);
4896 nommu_addchr(&ctx.as_string, ch);
4899 else if (next == '(') {
4900 syntax_error(">(process) not supported");
4904 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4906 continue; /* back to top of while (1) */
4908 redir_fd = redirect_opt_num(&dest);
4909 if (done_word(&dest, &ctx)) {
4912 redir_style = REDIRECT_INPUT;
4914 redir_style = REDIRECT_HEREDOC;
4916 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4917 ch = i_getch(input);
4918 nommu_addchr(&ctx.as_string, ch);
4919 } else if (next == '>') {
4920 redir_style = REDIRECT_IO;
4921 ch = i_getch(input);
4922 nommu_addchr(&ctx.as_string, ch);
4925 else if (next == '(') {
4926 syntax_error("<(process) not supported");
4930 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4932 continue; /* back to top of while (1) */
4934 if (dest.length == 0 && !dest.has_quoted_part) {
4935 /* skip "#comment" */
4938 if (ch == EOF || ch == '\n')
4941 /* note: we do not add it to &ctx.as_string */
4943 nommu_addchr(&ctx.as_string, '\n');
4944 continue; /* back to top of while (1) */
4949 /* It's "\<newline>" */
4951 /* Remove trailing '\' from ctx.as_string */
4952 ctx.as_string.data[--ctx.as_string.length] = '\0';
4954 ch = i_getch(input); /* eat it */
4955 continue; /* back to top of while (1) */
4960 if (dest.o_assignment == MAYBE_ASSIGNMENT
4961 /* check that we are not in word in "a=1 2>word b=1": */
4962 && !ctx.pending_redirect
4964 /* ch is a special char and thus this word
4965 * cannot be an assignment */
4966 dest.o_assignment = NOT_ASSIGNMENT;
4967 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4970 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4973 case '#': /* non-comment #: "echo a#b" etc */
4974 o_addQchr(&dest, ch);
4978 syntax_error("\\<eof>");
4981 ch = i_getch(input);
4982 /* note: ch != '\n' (that case does not reach this place) */
4983 o_addchr(&dest, '\\');
4984 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4985 o_addchr(&dest, ch);
4986 nommu_addchr(&ctx.as_string, ch);
4987 /* Example: echo Hello \2>file
4988 * we need to know that word 2 is quoted */
4989 dest.has_quoted_part = 1;
4992 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4993 debug_printf_parse("parse_stream parse error: "
4994 "parse_dollar returned 0 (error)\n");
4999 dest.has_quoted_part = 1;
5000 if (next == '\'' && !ctx.pending_redirect) {
5001 insert_empty_quoted_str_marker:
5002 nommu_addchr(&ctx.as_string, next);
5003 i_getch(input); /* eat second ' */
5004 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5005 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5008 ch = i_getch(input);
5010 syntax_error_unterm_ch('\'');
5013 nommu_addchr(&ctx.as_string, ch);
5016 o_addqchr(&dest, ch);
5021 dest.has_quoted_part = 1;
5022 if (next == '"' && !ctx.pending_redirect)
5023 goto insert_empty_quoted_str_marker;
5024 if (dest.o_assignment == NOT_ASSIGNMENT)
5025 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5026 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5028 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5030 #if ENABLE_HUSH_TICK
5032 USE_FOR_NOMMU(unsigned pos;)
5034 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5035 o_addchr(&dest, '`');
5036 USE_FOR_NOMMU(pos = dest.length;)
5037 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5040 o_addstr(&ctx.as_string, dest.data + pos);
5041 o_addchr(&ctx.as_string, '`');
5043 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5044 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5049 #if ENABLE_HUSH_CASE
5052 if (done_word(&dest, &ctx)) {
5055 done_pipe(&ctx, PIPE_SEQ);
5056 #if ENABLE_HUSH_CASE
5057 /* Eat multiple semicolons, detect
5058 * whether it means something special */
5063 ch = i_getch(input);
5064 nommu_addchr(&ctx.as_string, ch);
5065 if (ctx.ctx_res_w == RES_CASE_BODY) {
5066 ctx.ctx_dsemicolon = 1;
5067 ctx.ctx_res_w = RES_MATCH;
5073 /* We just finished a cmd. New one may start
5074 * with an assignment */
5075 dest.o_assignment = MAYBE_ASSIGNMENT;
5076 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5079 if (done_word(&dest, &ctx)) {
5083 ch = i_getch(input);
5084 nommu_addchr(&ctx.as_string, ch);
5085 done_pipe(&ctx, PIPE_AND);
5087 done_pipe(&ctx, PIPE_BG);
5091 if (done_word(&dest, &ctx)) {
5094 #if ENABLE_HUSH_CASE
5095 if (ctx.ctx_res_w == RES_MATCH)
5096 break; /* we are in case's "word | word)" */
5098 if (next == '|') { /* || */
5099 ch = i_getch(input);
5100 nommu_addchr(&ctx.as_string, ch);
5101 done_pipe(&ctx, PIPE_OR);
5103 /* we could pick up a file descriptor choice here
5104 * with redirect_opt_num(), but bash doesn't do it.
5105 * "echo foo 2| cat" yields "foo 2". */
5110 #if ENABLE_HUSH_CASE
5111 /* "case... in [(]word)..." - skip '(' */
5112 if (ctx.ctx_res_w == RES_MATCH
5113 && ctx.command->argv == NULL /* not (word|(... */
5114 && dest.length == 0 /* not word(... */
5115 && dest.has_quoted_part == 0 /* not ""(... */
5121 if (parse_group(&dest, &ctx, input, ch) != 0) {
5126 #if ENABLE_HUSH_CASE
5127 if (ctx.ctx_res_w == RES_MATCH)
5131 /* proper use of this character is caught by end_trigger:
5132 * if we see {, we call parse_group(..., end_trigger='}')
5133 * and it will match } earlier (not here). */
5134 syntax_error_unexpected_ch(ch);
5135 G.last_exitcode = 2;
5139 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5144 G.last_exitcode = 1;
5147 struct parse_context *pctx;
5148 IF_HAS_KEYWORDS(struct parse_context *p2;)
5150 /* Clean up allocated tree.
5151 * Sample for finding leaks on syntax error recovery path.
5152 * Run it from interactive shell, watch pmap `pidof hush`.
5153 * while if false; then false; fi; do break; fi
5154 * Samples to catch leaks at execution:
5155 * while if (true | { true;}); then echo ok; fi; do break; done
5156 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5160 /* Update pipe/command counts,
5161 * otherwise freeing may miss some */
5162 done_pipe(pctx, PIPE_SEQ);
5163 debug_printf_clean("freeing list %p from ctx %p\n",
5164 pctx->list_head, pctx);
5165 debug_print_tree(pctx->list_head, 0);
5166 free_pipe_list(pctx->list_head);
5167 debug_printf_clean("freed list %p\n", pctx->list_head);
5169 o_free_unsafe(&pctx->as_string);
5171 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5175 IF_HAS_KEYWORDS(pctx = p2;)
5176 } while (HAS_KEYWORDS && pctx);
5189 /*** Execution routines ***/
5191 /* Expansion can recurse, need forward decls: */
5192 #if !ENABLE_HUSH_BASH_COMPAT
5193 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5194 #define expand_string_to_string(str, do_unbackslash) \
5195 expand_string_to_string(str)
5197 static char *expand_string_to_string(const char *str, int do_unbackslash);
5198 #if ENABLE_HUSH_TICK
5199 static int process_command_subs(o_string *dest, const char *s);
5202 /* expand_strvec_to_strvec() takes a list of strings, expands
5203 * all variable references within and returns a pointer to
5204 * a list of expanded strings, possibly with larger number
5205 * of strings. (Think VAR="a b"; echo $VAR).
5206 * This new list is allocated as a single malloc block.
5207 * NULL-terminated list of char* pointers is at the beginning of it,
5208 * followed by strings themselves.
5209 * Caller can deallocate entire list by single free(list). */
5211 /* A horde of its helpers come first: */
5213 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5215 while (--len >= 0) {
5218 #if ENABLE_HUSH_BRACE_EXPANSION
5219 if (c == '{' || c == '}') {
5220 /* { -> \{, } -> \} */
5222 /* And now we want to add { or } and continue:
5225 * luckily, just falling throught achieves this.
5231 /* \z -> \\\z; \<eol> -> \\<eol> */
5236 o_addchr(o, *str++);
5242 /* Store given string, finalizing the word and starting new one whenever
5243 * we encounter IFS char(s). This is used for expanding variable values.
5244 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5245 * Return in *ended_with_ifs:
5246 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5248 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5250 int last_is_ifs = 0;
5255 if (!*str) /* EOL - do not finalize word */
5257 word_len = strcspn(str, G.ifs);
5259 /* We have WORD_LEN leading non-IFS chars */
5260 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5261 o_addblock(output, str, word_len);
5263 /* Protect backslashes against globbing up :)
5264 * Example: "v='\*'; echo b$v" prints "b\*"
5265 * (and does not try to glob on "*")
5267 o_addblock_duplicate_backslash(output, str, word_len);
5268 /*/ Why can't we do it easier? */
5269 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5270 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5274 if (!*str) /* EOL - do not finalize word */
5278 /* We know str here points to at least one IFS char */
5280 str += strspn(str, G.ifs); /* skip IFS chars */
5281 if (!*str) /* EOL - do not finalize word */
5284 /* Start new word... but not always! */
5285 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5286 if (output->has_quoted_part
5287 /* Case "v=' a'; echo $v":
5288 * here nothing precedes the space in $v expansion,
5289 * therefore we should not finish the word
5290 * (IOW: if there *is* word to finalize, only then do it):
5292 || (n > 0 && output->data[output->length - 1])
5294 o_addchr(output, '\0');
5295 debug_print_list("expand_on_ifs", output, n);
5296 n = o_save_ptr(output, n);
5301 *ended_with_ifs = last_is_ifs;
5302 debug_print_list("expand_on_ifs[1]", output, n);
5306 /* Helper to expand $((...)) and heredoc body. These act as if
5307 * they are in double quotes, with the exception that they are not :).
5308 * Just the rules are similar: "expand only $var and `cmd`"
5310 * Returns malloced string.
5311 * As an optimization, we return NULL if expansion is not needed.
5313 #if !ENABLE_HUSH_BASH_COMPAT
5314 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5315 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5316 encode_then_expand_string(str)
5318 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5321 struct in_str input;
5322 o_string dest = NULL_O_STRING;
5324 if (!strchr(str, '$')
5325 && !strchr(str, '\\')
5326 #if ENABLE_HUSH_TICK
5327 && !strchr(str, '`')
5333 /* We need to expand. Example:
5334 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5336 setup_string_in_str(&input, str);
5337 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5338 //TODO: error check (encode_string returns 0 on error)?
5339 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5340 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5341 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5342 o_free_unsafe(&dest);
5346 #if ENABLE_FEATURE_SH_MATH
5347 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5349 arith_state_t math_state;
5353 math_state.lookupvar = get_local_var_value;
5354 math_state.setvar = set_local_var_from_halves;
5355 //math_state.endofname = endofname;
5356 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5357 res = arith(&math_state, exp_str ? exp_str : arg);
5360 *errmsg_p = math_state.errmsg;
5361 if (math_state.errmsg)
5362 die_if_script(math_state.errmsg);
5367 #if ENABLE_HUSH_BASH_COMPAT
5368 /* ${var/[/]pattern[/repl]} helpers */
5369 static char *strstr_pattern(char *val, const char *pattern, int *size)
5372 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5373 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5380 /* Optimization: if "*pat" did not match the start of "string",
5381 * we know that "tring", "ring" etc will not match too:
5383 if (pattern[0] == '*')
5388 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5390 char *result = NULL;
5391 unsigned res_len = 0;
5392 unsigned repl_len = strlen(repl);
5396 char *s = strstr_pattern(val, pattern, &size);
5400 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5401 memcpy(result + res_len, val, s - val);
5403 strcpy(result + res_len, repl);
5404 res_len += repl_len;
5405 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5411 if (val[0] && result) {
5412 result = xrealloc(result, res_len + strlen(val) + 1);
5413 strcpy(result + res_len, val);
5414 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5416 debug_printf_varexp("result:'%s'\n", result);
5422 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5424 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5426 const char *val = NULL;
5427 char *to_be_freed = NULL;
5432 char exp_save = exp_save; /* for compiler */
5433 char *exp_saveptr; /* points to expansion operator */
5434 char *exp_word = exp_word; /* for compiler */
5437 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5439 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5441 first_char = arg[0] = arg0 & 0x7f;
5444 if (first_char == '#' /* ${#... */
5445 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5447 /* It must be length operator: ${#var} */
5451 /* Maybe handle parameter expansion */
5452 if (exp_saveptr /* if 2nd char is one of expansion operators */
5453 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5455 /* ${?:0}, ${#[:]%0} etc */
5456 exp_saveptr = var + 1;
5458 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5459 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5461 exp_op = exp_save = *exp_saveptr;
5463 exp_word = exp_saveptr + 1;
5464 if (exp_op == ':') {
5465 exp_op = *exp_word++;
5466 //TODO: try ${var:} and ${var:bogus} in non-bash config
5467 if (ENABLE_HUSH_BASH_COMPAT
5468 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5470 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5475 *exp_saveptr = '\0';
5476 } /* else: it's not an expansion op, but bare ${var} */
5479 /* Look up the variable in question */
5480 if (isdigit(var[0])) {
5481 /* parse_dollar should have vetted var for us */
5482 int n = xatoi_positive(var);
5483 if (n < G.global_argc)
5484 val = G.global_argv[n];
5485 /* else val remains NULL: $N with too big N */
5489 val = utoa(G.root_pid);
5491 case '!': /* bg pid */
5492 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5494 case '?': /* exitcode */
5495 val = utoa(G.last_exitcode);
5497 case '#': /* argc */
5498 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5501 val = get_local_var_value(var);
5505 /* Handle any expansions */
5506 if (exp_op == 'L') {
5507 reinit_unicode_for_hush();
5508 debug_printf_expand("expand: length(%s)=", val);
5509 val = utoa(val ? unicode_strlen(val) : 0);
5510 debug_printf_expand("%s\n", val);
5511 } else if (exp_op) {
5512 if (exp_op == '%' || exp_op == '#') {
5513 /* Standard-mandated substring removal ops:
5514 * ${parameter%word} - remove smallest suffix pattern
5515 * ${parameter%%word} - remove largest suffix pattern
5516 * ${parameter#word} - remove smallest prefix pattern
5517 * ${parameter##word} - remove largest prefix pattern
5519 * Word is expanded to produce a glob pattern.
5520 * Then var's value is matched to it and matching part removed.
5522 if (val && val[0]) {
5526 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5527 if (exp_op == *exp_word) /* ## or %% */
5529 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5531 exp_word = exp_exp_word;
5532 /* HACK ALERT. We depend here on the fact that
5533 * G.global_argv and results of utoa and get_local_var_value
5534 * are actually in writable memory:
5535 * scan_and_match momentarily stores NULs there. */
5537 loc = scan_and_match(t, exp_word, scan_flags);
5538 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5539 // exp_op, t, exp_word, loc);
5541 if (loc) { /* match was found */
5542 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5543 val = loc; /* take right part */
5545 val = to_be_freed = xstrndup(val, loc - val); /* left */
5549 #if ENABLE_HUSH_BASH_COMPAT
5550 else if (exp_op == '/' || exp_op == '\\') {
5551 /* It's ${var/[/]pattern[/repl]} thing.
5552 * Note that in encoded form it has TWO parts:
5553 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5554 * and if // is used, it is encoded as \:
5555 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5557 /* Empty variable always gives nothing: */
5558 // "v=''; echo ${v/*/w}" prints "", not "w"
5559 if (val && val[0]) {
5560 /* pattern uses non-standard expansion.
5561 * repl should be unbackslashed and globbed
5562 * by the usual expansion rules:
5564 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5565 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5566 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5567 * v='a bz'; echo ${v/a*z/\z} prints "z"
5568 * (note that a*z _pattern_ is never globbed!)
5570 char *pattern, *repl, *t;
5571 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5573 pattern = xstrdup(exp_word);
5574 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5575 *p++ = SPECIAL_VAR_SYMBOL;
5577 p = strchr(p, SPECIAL_VAR_SYMBOL);
5579 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5580 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5581 /* HACK ALERT. We depend here on the fact that
5582 * G.global_argv and results of utoa and get_local_var_value
5583 * are actually in writable memory:
5584 * replace_pattern momentarily stores NULs there. */
5586 to_be_freed = replace_pattern(t,
5588 (repl ? repl : exp_word),
5590 if (to_be_freed) /* at least one replace happened */
5597 else if (exp_op == ':') {
5598 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_FEATURE_SH_MATH
5599 /* It's ${var:N[:M]} bashism.
5600 * Note that in encoded form it has TWO parts:
5601 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5606 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5609 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5610 *p++ = SPECIAL_VAR_SYMBOL;
5612 p = strchr(p, SPECIAL_VAR_SYMBOL);
5614 len = expand_and_evaluate_arith(exp_word, &errmsg);
5617 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5618 if (len >= 0) { /* bash compat: len < 0 is illegal */
5619 if (beg < 0) /* bash compat */
5621 debug_printf_varexp("from val:'%s'\n", val);
5622 if (len == 0 || !val || beg >= strlen(val)) {
5626 /* Paranoia. What if user entered 9999999999999
5627 * which fits in arith_t but not int? */
5630 val = to_be_freed = xstrndup(val + beg, len);
5632 debug_printf_varexp("val:'%s'\n", val);
5636 die_if_script("malformed ${%s:...}", var);
5639 } else { /* one of "-=+?" */
5640 /* Standard-mandated substitution ops:
5641 * ${var?word} - indicate error if unset
5642 * If var is unset, word (or a message indicating it is unset
5643 * if word is null) is written to standard error
5644 * and the shell exits with a non-zero exit status.
5645 * Otherwise, the value of var is substituted.
5646 * ${var-word} - use default value
5647 * If var is unset, word is substituted.
5648 * ${var=word} - assign and use default value
5649 * If var is unset, word is assigned to var.
5650 * In all cases, final value of var is substituted.
5651 * ${var+word} - use alternative value
5652 * If var is unset, null is substituted.
5653 * Otherwise, word is substituted.
5655 * Word is subjected to tilde expansion, parameter expansion,
5656 * command substitution, and arithmetic expansion.
5657 * If word is not needed, it is not expanded.
5659 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5660 * but also treat null var as if it is unset.
5662 int use_word = (!val || ((exp_save == ':') && !val[0]));
5664 use_word = !use_word;
5665 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5666 (exp_save == ':') ? "true" : "false", use_word);
5668 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5670 exp_word = to_be_freed;
5671 if (exp_op == '?') {
5672 /* mimic bash message */
5673 die_if_script("%s: %s",
5675 exp_word[0] ? exp_word : "parameter null or not set"
5677 //TODO: how interactive bash aborts expansion mid-command?
5682 if (exp_op == '=') {
5683 /* ${var=[word]} or ${var:=[word]} */
5684 if (isdigit(var[0]) || var[0] == '#') {
5685 /* mimic bash message */
5686 die_if_script("$%s: cannot assign in this way", var);
5689 char *new_var = xasprintf("%s=%s", var, val);
5690 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5694 } /* one of "-=+?" */
5696 *exp_saveptr = exp_save;
5702 *to_be_freed_pp = to_be_freed;
5706 /* Expand all variable references in given string, adding words to list[]
5707 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5708 * to be filled). This routine is extremely tricky: has to deal with
5709 * variables/parameters with whitespace, $* and $@, and constructs like
5710 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5711 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5713 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5714 * expansion of right-hand side of assignment == 1-element expand.
5716 char cant_be_null = 0; /* only bit 0x80 matters */
5717 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5720 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5721 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5722 debug_print_list("expand_vars_to_list", output, n);
5723 n = o_save_ptr(output, n);
5724 debug_print_list("expand_vars_to_list[0]", output, n);
5726 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5728 char *to_be_freed = NULL;
5729 const char *val = NULL;
5730 #if ENABLE_HUSH_TICK
5731 o_string subst_result = NULL_O_STRING;
5733 #if ENABLE_FEATURE_SH_MATH
5734 char arith_buf[sizeof(arith_t)*3 + 2];
5738 o_addchr(output, '\0');
5739 n = o_save_ptr(output, n);
5743 o_addblock(output, arg, p - arg);
5744 debug_print_list("expand_vars_to_list[1]", output, n);
5746 p = strchr(p, SPECIAL_VAR_SYMBOL);
5748 /* Fetch special var name (if it is indeed one of them)
5749 * and quote bit, force the bit on if singleword expansion -
5750 * important for not getting v=$@ expand to many words. */
5751 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5753 /* Is this variable quoted and thus expansion can't be null?
5754 * "$@" is special. Even if quoted, it can still
5755 * expand to nothing (not even an empty string),
5756 * thus it is excluded. */
5757 if ((first_ch & 0x7f) != '@')
5758 cant_be_null |= first_ch;
5760 switch (first_ch & 0x7f) {
5761 /* Highest bit in first_ch indicates that var is double-quoted */
5765 if (!G.global_argv[1])
5768 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5769 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5770 while (G.global_argv[i]) {
5771 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5772 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5773 if (G.global_argv[i++][0] && G.global_argv[i]) {
5774 /* this argv[] is not empty and not last:
5775 * put terminating NUL, start new word */
5776 o_addchr(output, '\0');
5777 debug_print_list("expand_vars_to_list[2]", output, n);
5778 n = o_save_ptr(output, n);
5779 debug_print_list("expand_vars_to_list[3]", output, n);
5783 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5784 * and in this case should treat it like '$*' - see 'else...' below */
5785 if (first_ch == ('@'|0x80) /* quoted $@ */
5786 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5789 o_addQstr(output, G.global_argv[i]);
5790 if (++i >= G.global_argc)
5792 o_addchr(output, '\0');
5793 debug_print_list("expand_vars_to_list[4]", output, n);
5794 n = o_save_ptr(output, n);
5796 } else { /* quoted $* (or v="$@" case): add as one word */
5798 o_addQstr(output, G.global_argv[i]);
5799 if (!G.global_argv[++i])
5802 o_addchr(output, G.ifs[0]);
5804 output->has_quoted_part = 1;
5808 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5809 /* "Empty variable", used to make "" etc to not disappear */
5810 output->has_quoted_part = 1;
5812 cant_be_null = 0x80;
5814 #if ENABLE_HUSH_TICK
5815 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5816 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5818 /* Can't just stuff it into output o_string,
5819 * expanded result may need to be globbed
5820 * and $IFS-splitted */
5821 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5822 G.last_exitcode = process_command_subs(&subst_result, arg);
5823 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5824 val = subst_result.data;
5827 #if ENABLE_FEATURE_SH_MATH
5828 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5831 arg++; /* skip '+' */
5832 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5833 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5834 res = expand_and_evaluate_arith(arg, NULL);
5835 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5836 sprintf(arith_buf, ARITH_FMT, res);
5842 val = expand_one_var(&to_be_freed, arg, &p);
5843 IF_HUSH_TICK(store_val:)
5844 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5845 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5846 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5847 if (val && val[0]) {
5848 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5851 } else { /* quoted $VAR, val will be appended below */
5852 output->has_quoted_part = 1;
5853 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5854 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5857 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5859 if (val && val[0]) {
5860 o_addQstr(output, val);
5864 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5865 * Do the check to avoid writing to a const string. */
5866 if (*p != SPECIAL_VAR_SYMBOL)
5867 *p = SPECIAL_VAR_SYMBOL;
5869 #if ENABLE_HUSH_TICK
5870 o_free(&subst_result);
5873 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5877 o_addchr(output, '\0');
5878 n = o_save_ptr(output, n);
5880 debug_print_list("expand_vars_to_list[a]", output, n);
5881 /* this part is literal, and it was already pre-quoted
5882 * if needed (much earlier), do not use o_addQstr here! */
5883 o_addstr_with_NUL(output, arg);
5884 debug_print_list("expand_vars_to_list[b]", output, n);
5885 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5886 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5889 /* allow to reuse list[n] later without re-growth */
5890 output->has_empty_slot = 1;
5892 o_addchr(output, '\0');
5898 static char **expand_variables(char **argv, unsigned expflags)
5902 o_string output = NULL_O_STRING;
5904 output.o_expflags = expflags;
5908 n = expand_vars_to_list(&output, n, *argv);
5911 debug_print_list("expand_variables", &output, n);
5913 /* output.data (malloced in one block) gets returned in "list" */
5914 list = o_finalize_list(&output, n);
5915 debug_print_strings("expand_variables[1]", list);
5919 static char **expand_strvec_to_strvec(char **argv)
5921 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5924 #if ENABLE_HUSH_BASH_COMPAT
5925 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5927 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5931 /* Used for expansion of right hand of assignments,
5932 * $((...)), heredocs, variable espansion parts.
5934 * NB: should NOT do globbing!
5935 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5937 static char *expand_string_to_string(const char *str, int do_unbackslash)
5939 #if !ENABLE_HUSH_BASH_COMPAT
5940 const int do_unbackslash = 1;
5942 char *argv[2], **list;
5944 debug_printf_expand("string_to_string<='%s'\n", str);
5945 /* This is generally an optimization, but it also
5946 * handles "", which otherwise trips over !list[0] check below.
5947 * (is this ever happens that we actually get str="" here?)
5949 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5950 //TODO: Can use on strings with \ too, just unbackslash() them?
5951 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5952 return xstrdup(str);
5955 argv[0] = (char*)str;
5957 list = expand_variables(argv, do_unbackslash
5958 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5959 : EXP_FLAG_SINGLEWORD
5962 if (!list[0] || list[1])
5963 bb_error_msg_and_die("BUG in varexp2");
5964 /* actually, just move string 2*sizeof(char*) bytes back */
5965 overlapping_strcpy((char*)list, list[0]);
5967 unbackslash((char*)list);
5968 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5972 /* Used for "eval" builtin */
5973 static char* expand_strvec_to_string(char **argv)
5977 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5978 /* Convert all NULs to spaces */
5983 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5984 bb_error_msg_and_die("BUG in varexp3");
5985 /* bash uses ' ' regardless of $IFS contents */
5990 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5991 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5995 static char **expand_assignments(char **argv, int count)
6000 G.expanded_assignments = p = NULL;
6001 /* Expand assignments into one string each */
6002 for (i = 0; i < count; i++) {
6003 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6005 G.expanded_assignments = NULL;
6010 static void switch_off_special_sigs(unsigned mask)
6013 while ((mask >>= 1) != 0) {
6017 #if ENABLE_HUSH_TRAP
6019 if (G_traps[sig] && !G_traps[sig][0])
6020 /* trap is '', has to remain SIG_IGN */
6023 G_traps[sig] = NULL;
6026 /* We are here only if no trap or trap was not '' */
6027 install_sighandler(sig, SIG_DFL);
6033 void re_execute_shell(char ***to_free, const char *s,
6034 char *g_argv0, char **g_argv,
6035 char **builtin_argv) NORETURN;
6037 static void reset_traps_to_defaults(void)
6039 /* This function is always called in a child shell
6040 * after fork (not vfork, NOMMU doesn't use this function).
6042 IF_HUSH_TRAP(unsigned sig;)
6045 /* Child shells are not interactive.
6046 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6047 * Testcase: (while :; do :; done) + ^Z should background.
6048 * Same goes for SIGTERM, SIGHUP, SIGINT.
6050 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6051 if (!G_traps && !mask)
6052 return; /* already no traps and no special sigs */
6054 /* Switch off special sigs */
6055 switch_off_special_sigs(mask);
6056 # if ENABLE_HUSH_JOB
6057 G_fatal_sig_mask = 0;
6059 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6060 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6061 * remain set in G.special_sig_mask */
6063 # if ENABLE_HUSH_TRAP
6067 /* Reset all sigs to default except ones with empty traps */
6068 for (sig = 0; sig < NSIG; sig++) {
6070 continue; /* no trap: nothing to do */
6071 if (!G_traps[sig][0])
6072 continue; /* empty trap: has to remain SIG_IGN */
6073 /* sig has non-empty trap, reset it: */
6075 G_traps[sig] = NULL;
6076 /* There is no signal for trap 0 (EXIT) */
6079 install_sighandler(sig, pick_sighandler(sig));
6086 static void re_execute_shell(char ***to_free, const char *s,
6087 char *g_argv0, char **g_argv,
6088 char **builtin_argv) NORETURN;
6089 static void re_execute_shell(char ***to_free, const char *s,
6090 char *g_argv0, char **g_argv,
6091 char **builtin_argv)
6093 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6094 /* delims + 2 * (number of bytes in printed hex numbers) */
6095 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6096 char *heredoc_argv[4];
6097 struct variable *cur;
6098 # if ENABLE_HUSH_FUNCTIONS
6099 struct function *funcp;
6103 unsigned long long empty_trap_mask;
6105 if (!g_argv0) { /* heredoc */
6106 argv = heredoc_argv;
6107 argv[0] = (char *) G.argv0_for_re_execing;
6108 argv[1] = (char *) "-<";
6109 argv[2] = (char *) s;
6111 pp = &argv[3]; /* used as pointer to empty environment */
6117 if (pp) while (*pp++)
6120 empty_trap_mask = 0;
6123 for (sig = 1; sig < NSIG; sig++) {
6124 if (G_traps[sig] && !G_traps[sig][0])
6125 empty_trap_mask |= 1LL << sig;
6129 sprintf(param_buf, NOMMU_HACK_FMT
6130 , (unsigned) G.root_pid
6131 , (unsigned) G.root_ppid
6132 , (unsigned) G.last_bg_pid
6133 , (unsigned) G.last_exitcode
6136 IF_HUSH_LOOPS(, G.depth_of_loop)
6138 # undef NOMMU_HACK_FMT
6139 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6140 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6143 for (cur = G.top_var; cur; cur = cur->next) {
6144 if (!cur->flg_export || cur->flg_read_only)
6147 # if ENABLE_HUSH_FUNCTIONS
6148 for (funcp = G.top_func; funcp; funcp = funcp->next)
6154 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6155 *pp++ = (char *) G.argv0_for_re_execing;
6157 for (cur = G.top_var; cur; cur = cur->next) {
6158 if (strcmp(cur->varstr, hush_version_str) == 0)
6160 if (cur->flg_read_only) {
6161 *pp++ = (char *) "-R";
6162 *pp++ = cur->varstr;
6163 } else if (!cur->flg_export) {
6164 *pp++ = (char *) "-V";
6165 *pp++ = cur->varstr;
6168 # if ENABLE_HUSH_FUNCTIONS
6169 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6170 *pp++ = (char *) "-F";
6171 *pp++ = funcp->name;
6172 *pp++ = funcp->body_as_string;
6175 /* We can pass activated traps here. Say, -Tnn:trap_string
6177 * However, POSIX says that subshells reset signals with traps
6179 * I tested bash-3.2 and it not only does that with true subshells
6180 * of the form ( list ), but with any forked children shells.
6181 * I set trap "echo W" WINCH; and then tried:
6183 * { echo 1; sleep 20; echo 2; } &
6184 * while true; do echo 1; sleep 20; echo 2; break; done &
6185 * true | { echo 1; sleep 20; echo 2; } | cat
6187 * In all these cases sending SIGWINCH to the child shell
6188 * did not run the trap. If I add trap "echo V" WINCH;
6189 * _inside_ group (just before echo 1), it works.
6191 * I conclude it means we don't need to pass active traps here.
6193 *pp++ = (char *) "-c";
6196 while (*++builtin_argv)
6197 *pp++ = *builtin_argv;
6198 *pp++ = (char *) "";
6203 /* *pp = NULL; - is already there */
6207 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6208 /* Don't propagate SIG_IGN to the child */
6209 if (SPECIAL_JOBSTOP_SIGS != 0)
6210 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6211 execve(bb_busybox_exec_path, argv, pp);
6212 /* Fallback. Useful for init=/bin/hush usage etc */
6213 if (argv[0][0] == '/')
6214 execve(argv[0], argv, pp);
6215 xfunc_error_retval = 127;
6216 bb_error_msg_and_die("can't re-execute the shell");
6218 #endif /* !BB_MMU */
6221 static int run_and_free_list(struct pipe *pi);
6223 /* Executing from string: eval, sh -c '...'
6224 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6225 * end_trigger controls how often we stop parsing
6226 * NUL: parse all, execute, return
6227 * ';': parse till ';' or newline, execute, repeat till EOF
6229 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6231 /* Why we need empty flag?
6232 * An obscure corner case "false; ``; echo $?":
6233 * empty command in `` should still set $? to 0.
6234 * But we can't just set $? to 0 at the start,
6235 * this breaks "false; echo `echo $?`" case.
6239 struct pipe *pipe_list;
6241 #if ENABLE_HUSH_INTERACTIVE
6242 if (end_trigger == ';')
6243 inp->promptmode = 0; /* PS1 */
6245 pipe_list = parse_stream(NULL, inp, end_trigger);
6246 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6247 /* If we are in "big" script
6248 * (not in `cmd` or something similar)...
6250 if (pipe_list == ERR_PTR && end_trigger == ';') {
6251 /* Discard cached input (rest of line) */
6252 int ch = inp->last_char;
6253 while (ch != EOF && ch != '\n') {
6254 //bb_error_msg("Discarded:'%c'", ch);
6259 /* This stream isn't empty */
6263 if (!pipe_list && empty)
6264 G.last_exitcode = 0;
6267 debug_print_tree(pipe_list, 0);
6268 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6269 run_and_free_list(pipe_list);
6271 if (G_flag_return_in_progress == 1)
6276 static void parse_and_run_string(const char *s)
6278 struct in_str input;
6279 setup_string_in_str(&input, s);
6280 parse_and_run_stream(&input, '\0');
6283 static void parse_and_run_file(FILE *f)
6285 struct in_str input;
6286 setup_file_in_str(&input, f);
6287 parse_and_run_stream(&input, ';');
6290 #if ENABLE_HUSH_TICK
6291 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6296 char **to_free = NULL;
6300 pid = BB_MMU ? xfork() : xvfork();
6301 if (pid == 0) { /* child */
6302 disable_restore_tty_pgrp_on_exit();
6303 /* Process substitution is not considered to be usual
6304 * 'command execution'.
6305 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6312 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6313 close(channel[0]); /* NB: close _first_, then move fd! */
6314 xmove_fd(channel[1], 1);
6315 /* Prevent it from trying to handle ctrl-z etc */
6316 IF_HUSH_JOB(G.run_list_level = 1;)
6317 # if ENABLE_HUSH_TRAP
6318 /* Awful hack for `trap` or $(trap).
6320 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6321 * contains an example where "trap" is executed in a subshell:
6323 * save_traps=$(trap)
6325 * eval "$save_traps"
6327 * Standard does not say that "trap" in subshell shall print
6328 * parent shell's traps. It only says that its output
6329 * must have suitable form, but then, in the above example
6330 * (which is not supposed to be normative), it implies that.
6332 * bash (and probably other shell) does implement it
6333 * (traps are reset to defaults, but "trap" still shows them),
6334 * but as a result, "trap" logic is hopelessly messed up:
6337 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6338 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6339 * # true | trap <--- trap is in subshell - no output (ditto)
6340 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6341 * trap -- 'echo Ho' SIGWINCH
6342 * # echo `(trap)` <--- in subshell in subshell - output
6343 * trap -- 'echo Ho' SIGWINCH
6344 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6345 * trap -- 'echo Ho' SIGWINCH
6347 * The rules when to forget and when to not forget traps
6348 * get really complex and nonsensical.
6350 * Our solution: ONLY bare $(trap) or `trap` is special.
6352 s = skip_whitespace(s);
6353 if (is_prefixed_with(s, "trap")
6354 && skip_whitespace(s + 4)[0] == '\0'
6356 static const char *const argv[] = { NULL, NULL };
6357 builtin_trap((char**)argv);
6358 fflush_all(); /* important */
6363 reset_traps_to_defaults();
6364 parse_and_run_string(s);
6365 _exit(G.last_exitcode);
6367 /* We re-execute after vfork on NOMMU. This makes this script safe:
6368 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6369 * huge=`cat BIG` # was blocking here forever
6372 re_execute_shell(&to_free,
6382 # if ENABLE_HUSH_FAST
6384 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6385 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6386 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6388 enable_restore_tty_pgrp_on_exit();
6393 return remember_FILE(xfdopen_for_read(channel[0]));
6396 /* Return code is exit status of the process that is run. */
6397 static int process_command_subs(o_string *dest, const char *s)
6400 struct in_str pipe_str;
6402 int status, ch, eol_cnt;
6404 fp = generate_stream_from_string(s, &pid);
6406 /* Now send results of command back into original context */
6407 setup_file_in_str(&pipe_str, fp);
6409 while ((ch = i_getch(&pipe_str)) != EOF) {
6415 o_addchr(dest, '\n');
6418 o_addQchr(dest, ch);
6421 debug_printf("done reading from `cmd` pipe, closing it\n");
6422 fclose_and_forget(fp);
6423 /* We need to extract exitcode. Test case
6424 * "true; echo `sleep 1; false` $?"
6426 safe_waitpid(pid, &status, 0);
6427 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6428 return WEXITSTATUS(status);
6430 #endif /* ENABLE_HUSH_TICK */
6433 static void setup_heredoc(struct redir_struct *redir)
6435 struct fd_pair pair;
6438 /* the _body_ of heredoc (misleading field name) */
6439 const char *heredoc = redir->rd_filename;
6446 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6447 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6451 len = strlen(heredoc);
6453 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6455 xmove_fd(pair.rd, redir->rd_fd);
6457 /* Try writing without forking. Newer kernels have
6458 * dynamically growing pipes. Must use non-blocking write! */
6461 written = write(pair.wr, heredoc, len);
6472 ndelay_off(pair.wr);
6474 /* Okay, pipe buffer was not big enough */
6475 /* Note: we must not create a stray child (bastard? :)
6476 * for the unsuspecting parent process. Child creates a grandchild
6477 * and exits before parent execs the process which consumes heredoc
6478 * (that exec happens after we return from this function) */
6485 disable_restore_tty_pgrp_on_exit();
6486 pid = BB_MMU ? xfork() : xvfork();
6490 close(redir->rd_fd); /* read side of the pipe */
6492 full_write(pair.wr, heredoc, len); /* may loop or block */
6495 /* Delegate blocking writes to another process */
6496 xmove_fd(pair.wr, STDOUT_FILENO);
6497 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6501 #if ENABLE_HUSH_FAST
6503 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6505 enable_restore_tty_pgrp_on_exit();
6511 wait(NULL); /* wait till child has died */
6514 /* fd: redirect wants this fd to be used (e.g. 3>file).
6515 * Move all conflicting internally used fds,
6516 * and remember them so that we can restore them later.
6518 static int save_fds_on_redirect(int fd, int squirrel[3])
6521 /* Handle redirects of fds 0,1,2 */
6523 /* If we collide with an already moved stdio fd... */
6524 if (fd == squirrel[0]) {
6525 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6528 if (fd == squirrel[1]) {
6529 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6532 if (fd == squirrel[2]) {
6533 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6536 /* If we are about to redirect stdio fd, and did not yet move it... */
6537 if (fd <= 2 && squirrel[fd] < 0) {
6538 /* We avoid taking stdio fds */
6539 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6540 if (squirrel[fd] < 0 && errno != EBADF)
6542 return 0; /* "we did not close fd" */
6546 #if ENABLE_HUSH_INTERACTIVE
6547 if (fd != 0 && fd == G.interactive_fd) {
6548 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6553 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6554 * (1) Redirect in a forked child. No need to save FILEs' fds,
6555 * we aren't going to use them anymore, ok to trash.
6556 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6557 * but how are we doing to use them?
6558 * "fileno(fd) = new_fd" can't be done.
6563 return save_FILEs_on_redirect(fd);
6566 static void restore_redirects(int squirrel[3])
6569 for (i = 0; i <= 2; i++) {
6572 /* We simply die on error */
6577 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6579 restore_redirected_FILEs();
6582 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6583 * and stderr if they are redirected. */
6584 static int setup_redirects(struct command *prog, int squirrel[])
6587 struct redir_struct *redir;
6589 for (redir = prog->redirects; redir; redir = redir->next) {
6590 if (redir->rd_type == REDIRECT_HEREDOC2) {
6591 /* "rd_fd<<HERE" case */
6592 save_fds_on_redirect(redir->rd_fd, squirrel);
6593 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6595 debug_printf_parse("set heredoc '%s'\n",
6596 redir->rd_filename);
6597 setup_heredoc(redir);
6601 if (redir->rd_dup == REDIRFD_TO_FILE) {
6602 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6604 if (redir->rd_filename == NULL) {
6607 * "cmd >" (no filename)
6608 * "cmd > <file" (2nd redirect starts too early)
6610 die_if_script("syntax error: %s", "invalid redirect");
6613 mode = redir_table[redir->rd_type].mode;
6614 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6615 openfd = open_or_warn(p, mode);
6618 /* Error message from open_or_warn can be lost
6619 * if stderr has been redirected, but bash
6620 * and ash both lose it as well
6621 * (though zsh doesn't!)
6626 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6627 openfd = redir->rd_dup;
6630 if (openfd != redir->rd_fd) {
6631 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6632 if (openfd == REDIRFD_CLOSE) {
6633 /* "rd_fd >&-" means "close me" */
6635 /* ^^^ optimization: saving may already
6636 * have closed it. If not... */
6637 close(redir->rd_fd);
6640 xdup2(openfd, redir->rd_fd);
6641 if (redir->rd_dup == REDIRFD_TO_FILE)
6642 /* "rd_fd > FILE" */
6644 /* else: "rd_fd > rd_dup" */
6651 static char *find_in_path(const char *arg)
6654 const char *PATH = get_local_var_value("PATH");
6660 const char *end = strchrnul(PATH, ':');
6661 int sz = end - PATH; /* must be int! */
6665 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6667 /* We have xxx::yyyy in $PATH,
6668 * it means "use current dir" */
6671 if (access(ret, F_OK) == 0)
6684 static const struct built_in_command *find_builtin_helper(const char *name,
6685 const struct built_in_command *x,
6686 const struct built_in_command *end)
6689 if (strcmp(name, x->b_cmd) != 0) {
6693 debug_printf_exec("found builtin '%s'\n", name);
6698 static const struct built_in_command *find_builtin1(const char *name)
6700 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6702 static const struct built_in_command *find_builtin(const char *name)
6704 const struct built_in_command *x = find_builtin1(name);
6707 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6710 #if ENABLE_HUSH_FUNCTIONS
6711 static struct function **find_function_slot(const char *name)
6713 struct function **funcpp = &G.top_func;
6715 if (strcmp(name, (*funcpp)->name) == 0) {
6718 funcpp = &(*funcpp)->next;
6723 static const struct function *find_function(const char *name)
6725 const struct function *funcp = *find_function_slot(name);
6727 debug_printf_exec("found function '%s'\n", name);
6731 /* Note: takes ownership on name ptr */
6732 static struct function *new_function(char *name)
6734 struct function **funcpp = find_function_slot(name);
6735 struct function *funcp = *funcpp;
6737 if (funcp != NULL) {
6738 struct command *cmd = funcp->parent_cmd;
6739 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6741 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6743 /* Note: if !funcp->body, do not free body_as_string!
6744 * This is a special case of "-F name body" function:
6745 * body_as_string was not malloced! */
6747 free_pipe_list(funcp->body);
6749 free(funcp->body_as_string);
6753 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6754 cmd->argv[0] = funcp->name;
6755 cmd->group = funcp->body;
6757 cmd->group_as_string = funcp->body_as_string;
6761 debug_printf_exec("remembering new function '%s'\n", name);
6762 funcp = *funcpp = xzalloc(sizeof(*funcp));
6763 /*funcp->next = NULL;*/
6770 # if ENABLE_HUSH_UNSET
6771 static void unset_func(const char *name)
6773 struct function **funcpp = find_function_slot(name);
6774 struct function *funcp = *funcpp;
6776 if (funcp != NULL) {
6777 debug_printf_exec("freeing function '%s'\n", funcp->name);
6778 *funcpp = funcp->next;
6779 /* funcp is unlinked now, deleting it.
6780 * Note: if !funcp->body, the function was created by
6781 * "-F name body", do not free ->body_as_string
6782 * and ->name as they were not malloced. */
6784 free_pipe_list(funcp->body);
6787 free(funcp->body_as_string);
6796 #define exec_function(to_free, funcp, argv) \
6797 exec_function(funcp, argv)
6799 static void exec_function(char ***to_free,
6800 const struct function *funcp,
6801 char **argv) NORETURN;
6802 static void exec_function(char ***to_free,
6803 const struct function *funcp,
6809 argv[0] = G.global_argv[0];
6810 G.global_argv = argv;
6814 /* On MMU, funcp->body is always non-NULL */
6815 n = run_list(funcp->body);
6819 re_execute_shell(to_free,
6820 funcp->body_as_string,
6827 static int run_function(const struct function *funcp, char **argv)
6833 save_and_replace_G_args(&sv, argv);
6835 /* "we are in function, ok to use return" */
6836 sv_flg = G_flag_return_in_progress;
6837 G_flag_return_in_progress = -1;
6838 # if ENABLE_HUSH_LOCAL
6839 G.func_nest_level++;
6842 /* On MMU, funcp->body is always non-NULL */
6845 /* Function defined by -F */
6846 parse_and_run_string(funcp->body_as_string);
6847 rc = G.last_exitcode;
6851 rc = run_list(funcp->body);
6854 # if ENABLE_HUSH_LOCAL
6856 struct variable *var;
6857 struct variable **var_pp;
6859 var_pp = &G.top_var;
6860 while ((var = *var_pp) != NULL) {
6861 if (var->func_nest_level < G.func_nest_level) {
6862 var_pp = &var->next;
6866 if (var->flg_export)
6867 bb_unsetenv(var->varstr);
6868 /* Remove from global list */
6869 *var_pp = var->next;
6875 G.func_nest_level--;
6878 G_flag_return_in_progress = sv_flg;
6880 restore_G_args(&sv, argv);
6884 #endif /* ENABLE_HUSH_FUNCTIONS */
6888 #define exec_builtin(to_free, x, argv) \
6889 exec_builtin(x, argv)
6891 #define exec_builtin(to_free, x, argv) \
6892 exec_builtin(to_free, argv)
6894 static void exec_builtin(char ***to_free,
6895 const struct built_in_command *x,
6896 char **argv) NORETURN;
6897 static void exec_builtin(char ***to_free,
6898 const struct built_in_command *x,
6904 rcode = x->b_function(argv);
6909 /* On NOMMU, we must never block!
6910 * Example: { sleep 99 | read line; } & echo Ok
6912 re_execute_shell(to_free,
6921 static void execvp_or_die(char **argv) NORETURN;
6922 static void execvp_or_die(char **argv)
6925 debug_printf_exec("execing '%s'\n", argv[0]);
6926 /* Don't propagate SIG_IGN to the child */
6927 if (SPECIAL_JOBSTOP_SIGS != 0)
6928 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6929 execvp(argv[0], argv);
6931 if (errno == EACCES) e = 126;
6932 if (errno == ENOENT) e = 127;
6933 bb_perror_msg("can't execute '%s'", argv[0]);
6937 #if ENABLE_HUSH_MODE_X
6938 static void dump_cmd_in_x_mode(char **argv)
6940 if (G_x_mode && argv) {
6941 /* We want to output the line in one write op */
6949 len += strlen(argv[n++]) + 1;
6955 p += sprintf(p, " %s", argv[n++]);
6963 # define dump_cmd_in_x_mode(argv) ((void)0)
6967 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6968 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6969 #define pseudo_exec(nommu_save, command, argv_expanded) \
6970 pseudo_exec(command, argv_expanded)
6973 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6975 * Don't exit() here. If you don't exec, use _exit instead.
6976 * The at_exit handlers apparently confuse the calling process,
6977 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6979 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6980 char **argv, int assignment_cnt,
6981 char **argv_expanded) NORETURN;
6982 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6983 char **argv, int assignment_cnt,
6984 char **argv_expanded)
6988 new_env = expand_assignments(argv, assignment_cnt);
6989 dump_cmd_in_x_mode(new_env);
6991 if (!argv[assignment_cnt]) {
6992 /* Case when we are here: ... | var=val | ...
6993 * (note that we do not exit early, i.e., do not optimize out
6994 * expand_assignments(): think about ... | var=`sleep 1` | ...
6996 free_strings(new_env);
6997 _exit(EXIT_SUCCESS);
7001 set_vars_and_save_old(new_env);
7002 free(new_env); /* optional */
7003 /* we can also destroy set_vars_and_save_old's return value,
7006 nommu_save->new_env = new_env;
7007 nommu_save->old_vars = set_vars_and_save_old(new_env);
7010 if (argv_expanded) {
7011 argv = argv_expanded;
7013 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7015 nommu_save->argv = argv;
7018 dump_cmd_in_x_mode(argv);
7020 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7021 if (strchr(argv[0], '/') != NULL)
7025 /* Check if the command matches any of the builtins.
7026 * Depending on context, this might be redundant. But it's
7027 * easier to waste a few CPU cycles than it is to figure out
7028 * if this is one of those cases.
7031 /* On NOMMU, it is more expensive to re-execute shell
7032 * just in order to run echo or test builtin.
7033 * It's better to skip it here and run corresponding
7034 * non-builtin later. */
7035 const struct built_in_command *x;
7036 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7038 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7041 #if ENABLE_HUSH_FUNCTIONS
7042 /* Check if the command matches any functions */
7044 const struct function *funcp = find_function(argv[0]);
7046 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7051 #if ENABLE_FEATURE_SH_STANDALONE
7052 /* Check if the command matches any busybox applets */
7054 int a = find_applet_by_name(argv[0]);
7056 # if BB_MMU /* see above why on NOMMU it is not allowed */
7057 if (APPLET_IS_NOEXEC(a)) {
7058 /* Do not leak open fds from opened script files etc */
7059 close_all_FILE_list();
7060 debug_printf_exec("running applet '%s'\n", argv[0]);
7061 run_applet_no_and_exit(a, argv);
7064 /* Re-exec ourselves */
7065 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7066 /* Don't propagate SIG_IGN to the child */
7067 if (SPECIAL_JOBSTOP_SIGS != 0)
7068 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7069 execv(bb_busybox_exec_path, argv);
7070 /* If they called chroot or otherwise made the binary no longer
7071 * executable, fall through */
7076 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7079 execvp_or_die(argv);
7082 /* Called after [v]fork() in run_pipe
7084 static void pseudo_exec(nommu_save_t *nommu_save,
7085 struct command *command,
7086 char **argv_expanded) NORETURN;
7087 static void pseudo_exec(nommu_save_t *nommu_save,
7088 struct command *command,
7089 char **argv_expanded)
7091 if (command->argv) {
7092 pseudo_exec_argv(nommu_save, command->argv,
7093 command->assignment_cnt, argv_expanded);
7096 if (command->group) {
7097 /* Cases when we are here:
7100 * ... | ( list ) | ...
7101 * ... | { list } | ...
7105 debug_printf_exec("pseudo_exec: run_list\n");
7106 reset_traps_to_defaults();
7107 rcode = run_list(command->group);
7108 /* OK to leak memory by not calling free_pipe_list,
7109 * since this process is about to exit */
7112 re_execute_shell(&nommu_save->argv_from_re_execing,
7113 command->group_as_string,
7120 /* Case when we are here: ... | >file */
7121 debug_printf_exec("pseudo_exec'ed null command\n");
7122 _exit(EXIT_SUCCESS);
7126 static const char *get_cmdtext(struct pipe *pi)
7132 /* This is subtle. ->cmdtext is created only on first backgrounding.
7133 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7134 * On subsequent bg argv is trashed, but we won't use it */
7138 argv = pi->cmds[0].argv;
7140 pi->cmdtext = xzalloc(1);
7145 len += strlen(*argv) + 1;
7149 argv = pi->cmds[0].argv;
7151 p = stpcpy(p, *argv);
7158 static void insert_bg_job(struct pipe *pi)
7160 struct pipe *job, **jobp;
7163 /* Linear search for the ID of the job to use */
7165 for (job = G.job_list; job; job = job->next)
7166 if (job->jobid >= pi->jobid)
7167 pi->jobid = job->jobid + 1;
7169 /* Add job to the list of running jobs */
7171 while ((job = *jobp) != NULL)
7173 job = *jobp = xmalloc(sizeof(*job));
7175 *job = *pi; /* physical copy */
7177 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7178 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7179 for (i = 0; i < pi->num_cmds; i++) {
7180 job->cmds[i].pid = pi->cmds[i].pid;
7181 /* all other fields are not used and stay zero */
7183 job->cmdtext = xstrdup(get_cmdtext(pi));
7185 if (G_interactive_fd)
7186 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7187 G.last_jobid = job->jobid;
7190 static void remove_bg_job(struct pipe *pi)
7192 struct pipe *prev_pipe;
7194 if (pi == G.job_list) {
7195 G.job_list = pi->next;
7197 prev_pipe = G.job_list;
7198 while (prev_pipe->next != pi)
7199 prev_pipe = prev_pipe->next;
7200 prev_pipe->next = pi->next;
7203 G.last_jobid = G.job_list->jobid;
7208 /* Remove a backgrounded job */
7209 static void delete_finished_bg_job(struct pipe *pi)
7216 static int job_exited_or_stopped(struct pipe *pi)
7220 if (pi->alive_cmds != pi->stopped_cmds)
7223 /* All processes in fg pipe have exited or stopped */
7227 rcode = pi->cmds[i].cmd_exitcode;
7228 /* usually last process gives overall exitstatus,
7229 * but with "set -o pipefail", last *failed* process does */
7230 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7233 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7237 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7244 dead = WIFEXITED(status) || WIFSIGNALED(status);
7247 if (WIFSTOPPED(status))
7248 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7249 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7250 if (WIFSIGNALED(status))
7251 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7252 childpid, WTERMSIG(status), WEXITSTATUS(status));
7253 if (WIFEXITED(status))
7254 debug_printf_jobs("pid %d exited, exitcode %d\n",
7255 childpid, WEXITSTATUS(status));
7257 /* Were we asked to wait for a fg pipe? */
7259 i = fg_pipe->num_cmds;
7264 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7265 if (fg_pipe->cmds[i].pid != childpid)
7269 fg_pipe->cmds[i].pid = 0;
7270 fg_pipe->alive_cmds--;
7271 ex = WEXITSTATUS(status);
7272 /* bash prints killer signal's name for *last*
7273 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7274 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7276 if (WIFSIGNALED(status)) {
7277 int sig = WTERMSIG(status);
7278 if (i == fg_pipe->num_cmds-1)
7279 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7280 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7281 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7282 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7283 * Maybe we need to use sig | 128? */
7286 fg_pipe->cmds[i].cmd_exitcode = ex;
7288 fg_pipe->stopped_cmds++;
7290 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7291 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7292 rcode = job_exited_or_stopped(fg_pipe);
7294 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7295 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7296 * and "killall -STOP cat" */
7297 if (G_interactive_fd) {
7299 if (fg_pipe->alive_cmds != 0)
7300 insert_bg_job(fg_pipe);
7304 if (fg_pipe->alive_cmds == 0)
7307 /* There are still running processes in the fg_pipe */
7310 /* It wasnt in fg_pipe, look for process in bg pipes */
7314 /* We were asked to wait for bg or orphaned children */
7315 /* No need to remember exitcode in this case */
7316 for (pi = G.job_list; pi; pi = pi->next) {
7317 for (i = 0; i < pi->num_cmds; i++) {
7318 if (pi->cmds[i].pid == childpid)
7319 goto found_pi_and_prognum;
7322 /* Happens when shell is used as init process (init=/bin/sh) */
7323 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7324 return -1; /* this wasn't a process from fg_pipe */
7326 found_pi_and_prognum:
7329 pi->cmds[i].pid = 0;
7330 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7331 if (WIFSIGNALED(status))
7332 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7334 if (!pi->alive_cmds) {
7335 if (G_interactive_fd)
7336 printf(JOB_STATUS_FORMAT, pi->jobid,
7337 "Done", pi->cmdtext);
7338 delete_finished_bg_job(pi);
7345 return -1; /* this wasn't a process from fg_pipe */
7348 /* Check to see if any processes have exited -- if they have,
7349 * figure out why and see if a job has completed.
7351 * If non-NULL fg_pipe: wait for its completion or stop.
7352 * Return its exitcode or zero if stopped.
7354 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7355 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7356 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7357 * or 0 if no children changed status.
7359 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7360 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7361 * or 0 if no children changed status.
7363 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7369 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7371 attributes = WUNTRACED;
7372 if (fg_pipe == NULL)
7373 attributes |= WNOHANG;
7376 #if ENABLE_HUSH_FAST
7377 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7378 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7379 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7380 /* There was neither fork nor SIGCHLD since last waitpid */
7381 /* Avoid doing waitpid syscall if possible */
7382 if (!G.we_have_children) {
7386 if (fg_pipe == NULL) { /* is WNOHANG set? */
7387 /* We have children, but they did not exit
7388 * or stop yet (we saw no SIGCHLD) */
7391 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7395 /* Do we do this right?
7396 * bash-3.00# sleep 20 | false
7398 * [3]+ Stopped sleep 20 | false
7399 * bash-3.00# echo $?
7400 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7401 * [hush 1.14.0: yes we do it right]
7405 #if ENABLE_HUSH_FAST
7407 i = G.count_SIGCHLD;
7409 childpid = waitpid(-1, &status, attributes);
7410 if (childpid <= 0) {
7411 if (childpid && errno != ECHILD)
7412 bb_perror_msg("waitpid");
7413 #if ENABLE_HUSH_FAST
7414 else { /* Until next SIGCHLD, waitpid's are useless */
7415 G.we_have_children = (childpid == 0);
7416 G.handled_SIGCHLD = i;
7417 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7420 /* ECHILD (no children), or 0 (no change in children status) */
7424 rcode = process_wait_result(fg_pipe, childpid, status);
7426 /* fg_pipe exited or stopped */
7429 if (childpid == waitfor_pid) {
7430 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7431 rcode = WEXITSTATUS(status);
7432 if (WIFSIGNALED(status))
7433 rcode = 128 + WTERMSIG(status);
7434 if (WIFSTOPPED(status))
7435 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7436 rcode = 128 + WSTOPSIG(status);
7438 break; /* "wait PID" called us, give it exitcode+1 */
7440 /* This wasn't one of our processes, or */
7441 /* fg_pipe still has running processes, do waitpid again */
7442 } /* while (waitpid succeeds)... */
7448 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7451 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7452 if (G_saved_tty_pgrp) {
7453 /* Job finished, move the shell to the foreground */
7454 p = getpgrp(); /* our process group id */
7455 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7456 tcsetpgrp(G_interactive_fd, p);
7462 /* Start all the jobs, but don't wait for anything to finish.
7465 * Return code is normally -1, when the caller has to wait for children
7466 * to finish to determine the exit status of the pipe. If the pipe
7467 * is a simple builtin command, however, the action is done by the
7468 * time run_pipe returns, and the exit code is provided as the
7471 * Returns -1 only if started some children. IOW: we have to
7472 * mask out retvals of builtins etc with 0xff!
7474 * The only case when we do not need to [v]fork is when the pipe
7475 * is single, non-backgrounded, non-subshell command. Examples:
7476 * cmd ; ... { list } ; ...
7477 * cmd && ... { list } && ...
7478 * cmd || ... { list } || ...
7479 * If it is, then we can run cmd as a builtin, NOFORK,
7480 * or (if SH_STANDALONE) an applet, and we can run the { list }
7481 * with run_list. If it isn't one of these, we fork and exec cmd.
7483 * Cases when we must fork:
7484 * non-single: cmd | cmd
7485 * backgrounded: cmd & { list } &
7486 * subshell: ( list ) [&]
7488 #if !ENABLE_HUSH_MODE_X
7489 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7490 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7492 static int redirect_and_varexp_helper(char ***new_env_p,
7493 struct variable **old_vars_p,
7494 struct command *command,
7496 char **argv_expanded)
7498 /* setup_redirects acts on file descriptors, not FILEs.
7499 * This is perfect for work that comes after exec().
7500 * Is it really safe for inline use? Experimentally,
7501 * things seem to work. */
7502 int rcode = setup_redirects(command, squirrel);
7504 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7505 *new_env_p = new_env;
7506 dump_cmd_in_x_mode(new_env);
7507 dump_cmd_in_x_mode(argv_expanded);
7509 *old_vars_p = set_vars_and_save_old(new_env);
7513 static NOINLINE int run_pipe(struct pipe *pi)
7515 static const char *const null_ptr = NULL;
7519 struct command *command;
7520 char **argv_expanded;
7522 /* it is not always needed, but we aim to smaller code */
7523 int squirrel[] = { -1, -1, -1 };
7526 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7529 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7530 * Result should be 3 lines: q w e, qwe, q w e
7532 G.ifs = get_local_var_value("IFS");
7536 IF_HUSH_JOB(pi->pgrp = -1;)
7537 pi->stopped_cmds = 0;
7538 command = &pi->cmds[0];
7539 argv_expanded = NULL;
7541 if (pi->num_cmds != 1
7542 || pi->followup == PIPE_BG
7543 || command->cmd_type == CMD_SUBSHELL
7550 debug_printf_exec(": group:%p argv:'%s'\n",
7551 command->group, command->argv ? command->argv[0] : "NONE");
7553 if (command->group) {
7554 #if ENABLE_HUSH_FUNCTIONS
7555 if (command->cmd_type == CMD_FUNCDEF) {
7556 /* "executing" func () { list } */
7557 struct function *funcp;
7559 funcp = new_function(command->argv[0]);
7560 /* funcp->name is already set to argv[0] */
7561 funcp->body = command->group;
7563 funcp->body_as_string = command->group_as_string;
7564 command->group_as_string = NULL;
7566 command->group = NULL;
7567 command->argv[0] = NULL;
7568 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7569 funcp->parent_cmd = command;
7570 command->child_func = funcp;
7572 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7574 return EXIT_SUCCESS;
7578 debug_printf("non-subshell group\n");
7579 rcode = 1; /* exitcode if redir failed */
7580 if (setup_redirects(command, squirrel) == 0) {
7581 debug_printf_exec(": run_list\n");
7582 rcode = run_list(command->group) & 0xff;
7584 restore_redirects(squirrel);
7585 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7587 debug_printf_exec("run_pipe: return %d\n", rcode);
7591 argv = command->argv ? command->argv : (char **) &null_ptr;
7593 const struct built_in_command *x;
7594 #if ENABLE_HUSH_FUNCTIONS
7595 const struct function *funcp;
7599 char **new_env = NULL;
7600 struct variable *old_vars = NULL;
7602 if (argv[command->assignment_cnt] == NULL) {
7603 /* Assignments, but no command */
7604 /* Ensure redirects take effect (that is, create files).
7605 * Try "a=t >file" */
7606 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7607 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7608 /* Set shell variables */
7612 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7613 /* Do we need to flag set_local_var() errors?
7614 * "assignment to readonly var" and "putenv error"
7619 /* Redirect error sets $? to 1. Otherwise,
7620 * if evaluating assignment value set $?, retain it.
7621 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7623 rcode = G.last_exitcode;
7624 /* Exit, _skipping_ variable restoring code: */
7625 goto clean_up_and_ret0;
7627 #else /* Older, bigger, but more correct code */
7629 rcode = setup_redirects(command, squirrel);
7630 restore_redirects(squirrel);
7631 /* Set shell variables */
7633 bb_putchar_stderr('+');
7635 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7637 fprintf(stderr, " %s", p);
7638 debug_printf_exec("set shell var:'%s'->'%s'\n",
7640 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7641 /* Do we need to flag set_local_var() errors?
7642 * "assignment to readonly var" and "putenv error"
7647 bb_putchar_stderr('\n');
7648 /* Redirect error sets $? to 1. Otherwise,
7649 * if evaluating assignment value set $?, retain it.
7650 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7652 rcode = G.last_exitcode;
7653 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7655 debug_printf_exec("run_pipe: return %d\n", rcode);
7660 /* Expand the rest into (possibly) many strings each */
7661 #if ENABLE_HUSH_BASH_COMPAT
7662 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7663 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7667 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7670 /* if someone gives us an empty string: `cmd with empty output` */
7671 if (!argv_expanded[0]) {
7672 free(argv_expanded);
7674 return G.last_exitcode;
7677 x = find_builtin(argv_expanded[0]);
7678 #if ENABLE_HUSH_FUNCTIONS
7681 funcp = find_function(argv_expanded[0]);
7685 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7686 debug_printf("exec with redirects only\n");
7687 rcode = setup_redirects(command, NULL);
7688 /* rcode=1 can be if redir file can't be opened */
7689 goto clean_up_and_ret1;
7692 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7695 debug_printf_exec(": builtin '%s' '%s'...\n",
7696 x->b_cmd, argv_expanded[1]);
7698 rcode = x->b_function(argv_expanded) & 0xff;
7701 #if ENABLE_HUSH_FUNCTIONS
7703 # if ENABLE_HUSH_LOCAL
7704 struct variable **sv;
7705 sv = G.shadowed_vars_pp;
7706 G.shadowed_vars_pp = &old_vars;
7708 debug_printf_exec(": function '%s' '%s'...\n",
7709 funcp->name, argv_expanded[1]);
7710 rcode = run_function(funcp, argv_expanded) & 0xff;
7711 # if ENABLE_HUSH_LOCAL
7712 G.shadowed_vars_pp = sv;
7718 unset_vars(new_env);
7720 /* clean_up_and_ret0: */
7721 restore_redirects(squirrel);
7723 free(argv_expanded);
7724 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7726 debug_printf_exec("run_pipe return %d\n", rcode);
7730 if (ENABLE_FEATURE_SH_NOFORK) {
7731 int n = find_applet_by_name(argv_expanded[0]);
7732 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7733 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7735 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7736 argv_expanded[0], argv_expanded[1]);
7737 rcode = run_nofork_applet(n, argv_expanded);
7739 goto clean_up_and_ret;
7742 /* It is neither builtin nor applet. We must fork. */
7746 /* NB: argv_expanded may already be created, and that
7747 * might include `cmd` runs! Do not rerun it! We *must*
7748 * use argv_expanded if it's non-NULL */
7750 /* Going to fork a child per each pipe member */
7755 while (cmd_no < pi->num_cmds) {
7756 struct fd_pair pipefds;
7758 volatile nommu_save_t nommu_save;
7759 nommu_save.new_env = NULL;
7760 nommu_save.old_vars = NULL;
7761 nommu_save.argv = NULL;
7762 nommu_save.argv_from_re_execing = NULL;
7764 command = &pi->cmds[cmd_no];
7766 if (command->argv) {
7767 debug_printf_exec(": pipe member '%s' '%s'...\n",
7768 command->argv[0], command->argv[1]);
7770 debug_printf_exec(": pipe member with no argv\n");
7773 /* pipes are inserted between pairs of commands */
7776 if (cmd_no < pi->num_cmds)
7777 xpiped_pair(pipefds);
7779 command->pid = BB_MMU ? fork() : vfork();
7780 if (!command->pid) { /* child */
7782 disable_restore_tty_pgrp_on_exit();
7783 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7785 /* Every child adds itself to new process group
7786 * with pgid == pid_of_first_child_in_pipe */
7787 if (G.run_list_level == 1 && G_interactive_fd) {
7790 if (pgrp < 0) /* true for 1st process only */
7792 if (setpgid(0, pgrp) == 0
7793 && pi->followup != PIPE_BG
7794 && G_saved_tty_pgrp /* we have ctty */
7796 /* We do it in *every* child, not just first,
7798 tcsetpgrp(G_interactive_fd, pgrp);
7802 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7803 /* 1st cmd in backgrounded pipe
7804 * should have its stdin /dev/null'ed */
7806 if (open(bb_dev_null, O_RDONLY))
7807 xopen("/", O_RDONLY);
7809 xmove_fd(next_infd, 0);
7811 xmove_fd(pipefds.wr, 1);
7814 /* Like bash, explicit redirects override pipes,
7815 * and the pipe fd (fd#1) is available for dup'ing:
7816 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7817 * of cmd1 goes into pipe.
7819 if (setup_redirects(command, NULL)) {
7820 /* Happens when redir file can't be opened:
7821 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7823 * hush: can't open '/qwe/rty': No such file or directory
7825 * (echo BAR is not executed, it hits _exit(1) below)
7830 /* Stores to nommu_save list of env vars putenv'ed
7831 * (NOMMU, on MMU we don't need that) */
7832 /* cast away volatility... */
7833 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7834 /* pseudo_exec() does not return */
7837 /* parent or error */
7838 #if ENABLE_HUSH_FAST
7840 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7842 enable_restore_tty_pgrp_on_exit();
7844 /* Clean up after vforked child */
7845 free(nommu_save.argv);
7846 free(nommu_save.argv_from_re_execing);
7847 unset_vars(nommu_save.new_env);
7848 add_vars(nommu_save.old_vars);
7850 free(argv_expanded);
7851 argv_expanded = NULL;
7852 if (command->pid < 0) { /* [v]fork failed */
7853 /* Clearly indicate, was it fork or vfork */
7854 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7858 /* Second and next children need to know pid of first one */
7860 pi->pgrp = command->pid;
7866 if (cmd_no < pi->num_cmds)
7868 /* Pass read (output) pipe end to next iteration */
7869 next_infd = pipefds.rd;
7872 if (!pi->alive_cmds) {
7874 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7879 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7883 /* NB: called by pseudo_exec, and therefore must not modify any
7884 * global data until exec/_exit (we can be a child after vfork!) */
7885 static int run_list(struct pipe *pi)
7887 #if ENABLE_HUSH_CASE
7888 char *case_word = NULL;
7890 #if ENABLE_HUSH_LOOPS
7891 struct pipe *loop_top = NULL;
7892 char **for_lcur = NULL;
7893 char **for_list = NULL;
7895 smallint last_followup;
7897 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7898 smalluint cond_code = 0;
7900 enum { cond_code = 0 };
7903 smallint rword; /* RES_foo */
7904 smallint last_rword; /* ditto */
7907 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7910 #if ENABLE_HUSH_LOOPS
7911 /* Check syntax for "for" */
7914 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7915 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7917 /* current word is FOR or IN (BOLD in comments below) */
7918 if (cpipe->next == NULL) {
7919 syntax_error("malformed for");
7921 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7924 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7925 if (cpipe->next->res_word == RES_DO)
7927 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7928 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7929 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7931 syntax_error("malformed for");
7933 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7940 /* Past this point, all code paths should jump to ret: label
7941 * in order to return, no direct "return" statements please.
7942 * This helps to ensure that no memory is leaked. */
7950 last_rword = RES_XXXX;
7952 last_followup = PIPE_SEQ;
7953 rcode = G.last_exitcode;
7955 /* Go through list of pipes, (maybe) executing them. */
7956 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7961 if (G_flag_return_in_progress == 1)
7964 IF_HAS_KEYWORDS(rword = pi->res_word;)
7965 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7966 rword, cond_code, last_rword);
7967 #if ENABLE_HUSH_LOOPS
7968 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7969 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7971 /* start of a loop: remember where loop starts */
7976 /* Still in the same "if...", "then..." or "do..." branch? */
7977 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7978 if ((rcode == 0 && last_followup == PIPE_OR)
7979 || (rcode != 0 && last_followup == PIPE_AND)
7981 /* It is "<true> || CMD" or "<false> && CMD"
7982 * and we should not execute CMD */
7983 debug_printf_exec("skipped cmd because of || or &&\n");
7984 last_followup = pi->followup;
7985 goto dont_check_jobs_but_continue;
7988 last_followup = pi->followup;
7989 IF_HAS_KEYWORDS(last_rword = rword;)
7992 if (rword == RES_THEN) {
7993 /* if false; then ... fi has exitcode 0! */
7994 G.last_exitcode = rcode = EXIT_SUCCESS;
7995 /* "if <false> THEN cmd": skip cmd */
7999 if (rword == RES_ELSE || rword == RES_ELIF) {
8000 /* "if <true> then ... ELSE/ELIF cmd":
8001 * skip cmd and all following ones */
8006 #if ENABLE_HUSH_LOOPS
8007 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8009 /* first loop through for */
8011 static const char encoded_dollar_at[] ALIGN1 = {
8012 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8013 }; /* encoded representation of "$@" */
8014 static const char *const encoded_dollar_at_argv[] = {
8015 encoded_dollar_at, NULL
8016 }; /* argv list with one element: "$@" */
8019 vals = (char**)encoded_dollar_at_argv;
8020 if (pi->next->res_word == RES_IN) {
8021 /* if no variable values after "in" we skip "for" */
8022 if (!pi->next->cmds[0].argv) {
8023 G.last_exitcode = rcode = EXIT_SUCCESS;
8024 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8027 vals = pi->next->cmds[0].argv;
8028 } /* else: "for var; do..." -> assume "$@" list */
8029 /* create list of variable values */
8030 debug_print_strings("for_list made from", vals);
8031 for_list = expand_strvec_to_strvec(vals);
8032 for_lcur = for_list;
8033 debug_print_strings("for_list", for_list);
8036 /* "for" loop is over, clean up */
8042 /* Insert next value from for_lcur */
8043 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8044 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8047 if (rword == RES_IN) {
8048 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8050 if (rword == RES_DONE) {
8051 continue; /* "done" has no cmds too */
8054 #if ENABLE_HUSH_CASE
8055 if (rword == RES_CASE) {
8056 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8057 case_word = expand_strvec_to_string(pi->cmds->argv);
8060 if (rword == RES_MATCH) {
8063 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8064 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8066 /* all prev words didn't match, does this one match? */
8067 argv = pi->cmds->argv;
8069 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8070 /* TODO: which FNM_xxx flags to use? */
8071 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8073 if (cond_code == 0) { /* match! we will execute this branch */
8075 case_word = NULL; /* make future "word)" stop */
8082 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8083 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8085 continue; /* not matched yet, skip this pipe */
8087 if (rword == RES_ESAC) {
8088 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8090 /* "case" did not match anything: still set $? (to 0) */
8091 G.last_exitcode = rcode = EXIT_SUCCESS;
8095 /* Just pressing <enter> in shell should check for jobs.
8096 * OTOH, in non-interactive shell this is useless
8097 * and only leads to extra job checks */
8098 if (pi->num_cmds == 0) {
8099 if (G_interactive_fd)
8100 goto check_jobs_and_continue;
8104 /* After analyzing all keywords and conditions, we decided
8105 * to execute this pipe. NB: have to do checkjobs(NULL)
8106 * after run_pipe to collect any background children,
8107 * even if list execution is to be stopped. */
8108 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8109 #if ENABLE_HUSH_LOOPS
8110 G.flag_break_continue = 0;
8112 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8114 /* We ran a builtin, function, or group.
8115 * rcode is already known
8116 * and we don't need to wait for anything. */
8117 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8118 G.last_exitcode = rcode;
8119 check_and_run_traps();
8120 #if ENABLE_HUSH_LOOPS
8121 /* Was it "break" or "continue"? */
8122 if (G.flag_break_continue) {
8123 smallint fbc = G.flag_break_continue;
8124 /* We might fall into outer *loop*,
8125 * don't want to break it too */
8127 G.depth_break_continue--;
8128 if (G.depth_break_continue == 0)
8129 G.flag_break_continue = 0;
8130 /* else: e.g. "continue 2" should *break* once, *then* continue */
8131 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8132 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8133 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8136 /* "continue": simulate end of loop */
8141 if (G_flag_return_in_progress == 1) {
8142 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8145 } else if (pi->followup == PIPE_BG) {
8146 /* What does bash do with attempts to background builtins? */
8147 /* even bash 3.2 doesn't do that well with nested bg:
8148 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8149 * I'm NOT treating inner &'s as jobs */
8151 if (G.run_list_level == 1)
8154 /* Last command's pid goes to $! */
8155 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8156 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8157 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8158 rcode = EXIT_SUCCESS;
8162 if (G.run_list_level == 1 && G_interactive_fd) {
8163 /* Waits for completion, then fg's main shell */
8164 rcode = checkjobs_and_fg_shell(pi);
8165 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8169 /* This one just waits for completion */
8170 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8171 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8173 G.last_exitcode = rcode;
8174 check_and_run_traps();
8177 /* Analyze how result affects subsequent commands */
8179 if (rword == RES_IF || rword == RES_ELIF)
8182 check_jobs_and_continue:
8183 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8184 dont_check_jobs_but_continue: ;
8185 #if ENABLE_HUSH_LOOPS
8186 /* Beware of "while false; true; do ..."! */
8188 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8189 /* check for RES_DONE is needed for "while ...; do \n done" case */
8191 if (rword == RES_WHILE) {
8193 /* "while false; do...done" - exitcode 0 */
8194 G.last_exitcode = rcode = EXIT_SUCCESS;
8195 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8199 if (rword == RES_UNTIL) {
8201 debug_printf_exec(": until expr is true: breaking\n");
8212 #if ENABLE_HUSH_LOOPS
8217 #if ENABLE_HUSH_CASE
8221 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8225 /* Select which version we will use */
8226 static int run_and_free_list(struct pipe *pi)
8229 debug_printf_exec("run_and_free_list entered\n");
8230 if (!G.o_opt[OPT_O_NOEXEC]) {
8231 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8232 rcode = run_list(pi);
8234 /* free_pipe_list has the side effect of clearing memory.
8235 * In the long run that function can be merged with run_list,
8236 * but doing that now would hobble the debugging effort. */
8238 debug_printf_exec("run_and_free_list return %d\n", rcode);
8243 static void install_sighandlers(unsigned mask)
8245 sighandler_t old_handler;
8247 while ((mask >>= 1) != 0) {
8251 old_handler = install_sighandler(sig, pick_sighandler(sig));
8252 /* POSIX allows shell to re-enable SIGCHLD
8253 * even if it was SIG_IGN on entry.
8254 * Therefore we skip IGN check for it:
8258 if (old_handler == SIG_IGN) {
8259 /* oops... restore back to IGN, and record this fact */
8260 install_sighandler(sig, old_handler);
8261 #if ENABLE_HUSH_TRAP
8263 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8265 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8271 /* Called a few times only (or even once if "sh -c") */
8272 static void install_special_sighandlers(void)
8276 /* Which signals are shell-special? */
8277 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8278 if (G_interactive_fd) {
8279 mask |= SPECIAL_INTERACTIVE_SIGS;
8280 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8281 mask |= SPECIAL_JOBSTOP_SIGS;
8283 /* Careful, do not re-install handlers we already installed */
8284 if (G.special_sig_mask != mask) {
8285 unsigned diff = mask & ~G.special_sig_mask;
8286 G.special_sig_mask = mask;
8287 install_sighandlers(diff);
8293 /* Set handlers to restore tty pgrp and exit */
8294 static void install_fatal_sighandlers(void)
8298 /* We will restore tty pgrp on these signals */
8300 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8301 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8302 + (1 << SIGBUS ) * HUSH_DEBUG
8303 + (1 << SIGSEGV) * HUSH_DEBUG
8304 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8306 /* bash 3.2 seems to handle these just like 'fatal' ones */
8309 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8310 * if we aren't interactive... but in this case
8311 * we never want to restore pgrp on exit, and this fn is not called
8313 /*+ (1 << SIGHUP )*/
8314 /*+ (1 << SIGTERM)*/
8315 /*+ (1 << SIGINT )*/
8317 G_fatal_sig_mask = mask;
8319 install_sighandlers(mask);
8323 static int set_mode(int state, char mode, const char *o_opt)
8328 G.o_opt[OPT_O_NOEXEC] = state;
8331 IF_HUSH_MODE_X(G_x_mode = state;)
8335 /* "set -+o" without parameter.
8336 * in bash, set -o produces this output:
8340 * We always use the second form.
8342 const char *p = o_opt_strings;
8345 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8351 idx = index_in_strings(o_opt_strings, o_opt);
8353 G.o_opt[idx] = state;
8357 return EXIT_FAILURE;
8359 return EXIT_SUCCESS;
8362 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8363 int hush_main(int argc, char **argv)
8366 OPT_login = (1 << 0),
8370 unsigned builtin_argc;
8372 struct variable *cur_var;
8373 struct variable *shell_ver;
8376 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8377 G.last_exitcode = EXIT_SUCCESS;
8379 #if ENABLE_HUSH_FAST
8380 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8383 G.argv0_for_re_execing = argv[0];
8385 /* Deal with HUSH_VERSION */
8386 shell_ver = xzalloc(sizeof(*shell_ver));
8387 shell_ver->flg_export = 1;
8388 shell_ver->flg_read_only = 1;
8389 /* Code which handles ${var<op>...} needs writable values for all variables,
8390 * therefore we xstrdup: */
8391 shell_ver->varstr = xstrdup(hush_version_str);
8392 /* Create shell local variables from the values
8393 * currently living in the environment */
8394 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8395 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8396 G.top_var = shell_ver;
8397 cur_var = G.top_var;
8400 char *value = strchr(*e, '=');
8401 if (value) { /* paranoia */
8402 cur_var->next = xzalloc(sizeof(*cur_var));
8403 cur_var = cur_var->next;
8404 cur_var->varstr = *e;
8405 cur_var->max_len = strlen(*e);
8406 cur_var->flg_export = 1;
8410 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8411 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8412 putenv(shell_ver->varstr);
8415 set_pwd_var(/*exp:*/ 1);
8417 #if ENABLE_HUSH_BASH_COMPAT
8418 /* Set (but not export) HOSTNAME unless already set */
8419 if (!get_local_var_value("HOSTNAME")) {
8422 set_local_var_from_halves("HOSTNAME", uts.nodename);
8424 /* bash also exports SHLVL and _,
8425 * and sets (but doesn't export) the following variables:
8427 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8428 * BASH_VERSION='3.2.0(1)-release'
8430 * MACHTYPE=i386-pc-linux-gnu
8432 * PPID=<NNNNN> - we also do it elsewhere
8443 * PIPESTATUS=([0]="0")
8444 * HISTFILE=/<xxx>/.bash_history
8448 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8450 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8461 #if ENABLE_FEATURE_EDITING
8462 G.line_input_state = new_line_input_t(FOR_SHELL);
8465 /* Initialize some more globals to non-zero values */
8466 cmdedit_update_prompt();
8468 die_func = restore_ttypgrp_and__exit;
8470 /* Shell is non-interactive at first. We need to call
8471 * install_special_sighandlers() if we are going to execute "sh <script>",
8472 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8473 * If we later decide that we are interactive, we run install_special_sighandlers()
8474 * in order to intercept (more) signals.
8478 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8479 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8482 opt = getopt(argc, argv, "+c:xinsl"
8485 # if ENABLE_HUSH_FUNCTIONS
8495 * sh ... -c 'script'
8496 * sh ... -c 'script' ARG0 [ARG1...]
8497 * On NOMMU, if builtin_argc != 0,
8498 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8499 * "" needs to be replaced with NULL
8500 * and BARGV vector fed to builtin function.
8501 * Note: the form without ARG0 never happens:
8502 * sh ... -c 'builtin' BARGV... ""
8505 G.root_pid = getpid();
8506 G.root_ppid = getppid();
8508 G.global_argv = argv + optind;
8509 G.global_argc = argc - optind;
8511 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8512 const struct built_in_command *x;
8514 install_special_sighandlers();
8515 x = find_builtin(optarg);
8516 if (x) { /* paranoia */
8517 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8518 G.global_argv += builtin_argc;
8519 G.global_argv[-1] = NULL; /* replace "" */
8521 G.last_exitcode = x->b_function(argv + optind - 1);
8525 if (!G.global_argv[0]) {
8526 /* -c 'script' (no params): prevent empty $0 */
8527 G.global_argv--; /* points to argv[i] of 'script' */
8528 G.global_argv[0] = argv[0];
8530 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8531 install_special_sighandlers();
8532 parse_and_run_string(optarg);
8535 /* Well, we cannot just declare interactiveness,
8536 * we have to have some stuff (ctty, etc) */
8537 /* G_interactive_fd++; */
8540 /* "-s" means "read from stdin", but this is how we always
8541 * operate, so simply do nothing here. */
8547 case '<': /* "big heredoc" support */
8548 full_write1_str(optarg);
8551 unsigned long long empty_trap_mask;
8553 G.root_pid = bb_strtou(optarg, &optarg, 16);
8555 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8557 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8559 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8561 builtin_argc = bb_strtou(optarg, &optarg, 16);
8563 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8564 if (empty_trap_mask != 0) {
8566 install_special_sighandlers();
8567 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8568 for (sig = 1; sig < NSIG; sig++) {
8569 if (empty_trap_mask & (1LL << sig)) {
8570 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8571 install_sighandler(sig, SIG_IGN);
8575 # if ENABLE_HUSH_LOOPS
8577 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8583 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8585 # if ENABLE_HUSH_FUNCTIONS
8587 struct function *funcp = new_function(optarg);
8588 /* funcp->name is already set to optarg */
8589 /* funcp->body is set to NULL. It's a special case. */
8590 funcp->body_as_string = argv[optind];
8598 if (set_mode(1, opt, NULL) == 0) /* no error */
8602 fprintf(stderr, "Usage: sh [FILE]...\n"
8603 " or: sh -c command [args]...\n\n");
8609 } /* option parsing loop */
8611 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8612 G.global_argc = argc - (optind - 1);
8613 G.global_argv = argv + (optind - 1);
8614 G.global_argv[0] = argv[0];
8617 G.root_pid = getpid();
8618 G.root_ppid = getppid();
8621 /* If we are login shell... */
8622 if (flags & OPT_login) {
8624 debug_printf("sourcing /etc/profile\n");
8625 input = fopen_for_read("/etc/profile");
8626 if (input != NULL) {
8627 remember_FILE(input);
8628 install_special_sighandlers();
8629 parse_and_run_file(input);
8630 fclose_and_forget(input);
8632 /* bash: after sourcing /etc/profile,
8633 * tries to source (in the given order):
8634 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8635 * stopping on first found. --noprofile turns this off.
8636 * bash also sources ~/.bash_logout on exit.
8637 * If called as sh, skips .bash_XXX files.
8641 if (G.global_argv[1]) {
8644 * "bash <script>" (which is never interactive (unless -i?))
8645 * sources $BASH_ENV here (without scanning $PATH).
8646 * If called as sh, does the same but with $ENV.
8647 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8651 debug_printf("running script '%s'\n", G.global_argv[0]);
8652 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8653 input = xfopen_for_read(G.global_argv[0]);
8654 xfunc_error_retval = 1;
8655 remember_FILE(input);
8656 install_special_sighandlers();
8657 parse_and_run_file(input);
8658 #if ENABLE_FEATURE_CLEAN_UP
8659 fclose_and_forget(input);
8664 /* Up to here, shell was non-interactive. Now it may become one.
8665 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8668 /* A shell is interactive if the '-i' flag was given,
8669 * or if all of the following conditions are met:
8671 * no arguments remaining or the -s flag given
8672 * standard input is a terminal
8673 * standard output is a terminal
8674 * Refer to Posix.2, the description of the 'sh' utility.
8677 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8678 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8679 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8680 if (G_saved_tty_pgrp < 0)
8681 G_saved_tty_pgrp = 0;
8683 /* try to dup stdin to high fd#, >= 255 */
8684 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8685 if (G_interactive_fd < 0) {
8686 /* try to dup to any fd */
8687 G_interactive_fd = dup(STDIN_FILENO);
8688 if (G_interactive_fd < 0) {
8690 G_interactive_fd = 0;
8691 G_saved_tty_pgrp = 0;
8694 // TODO: track & disallow any attempts of user
8695 // to (inadvertently) close/redirect G_interactive_fd
8697 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8698 if (G_interactive_fd) {
8699 close_on_exec_on(G_interactive_fd);
8701 if (G_saved_tty_pgrp) {
8702 /* If we were run as 'hush &', sleep until we are
8703 * in the foreground (tty pgrp == our pgrp).
8704 * If we get started under a job aware app (like bash),
8705 * make sure we are now in charge so we don't fight over
8706 * who gets the foreground */
8708 pid_t shell_pgrp = getpgrp();
8709 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8710 if (G_saved_tty_pgrp == shell_pgrp)
8712 /* send TTIN to ourself (should stop us) */
8713 kill(- shell_pgrp, SIGTTIN);
8717 /* Install more signal handlers */
8718 install_special_sighandlers();
8720 if (G_saved_tty_pgrp) {
8721 /* Set other signals to restore saved_tty_pgrp */
8722 install_fatal_sighandlers();
8723 /* Put ourselves in our own process group
8724 * (bash, too, does this only if ctty is available) */
8725 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8726 /* Grab control of the terminal */
8727 tcsetpgrp(G_interactive_fd, getpid());
8729 enable_restore_tty_pgrp_on_exit();
8731 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8733 const char *hp = get_local_var_value("HISTFILE");
8735 hp = get_local_var_value("HOME");
8737 hp = concat_path_file(hp, ".hush_history");
8742 G.line_input_state->hist_file = hp;
8743 //set_local_var(xasprintf("HISTFILE=%s", ...));
8745 # if ENABLE_FEATURE_SH_HISTFILESIZE
8746 hp = get_local_var_value("HISTFILESIZE");
8747 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8752 install_special_sighandlers();
8754 #elif ENABLE_HUSH_INTERACTIVE
8755 /* No job control compiled in, only prompt/line editing */
8756 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8757 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8758 if (G_interactive_fd < 0) {
8759 /* try to dup to any fd */
8760 G_interactive_fd = dup(STDIN_FILENO);
8761 if (G_interactive_fd < 0)
8763 G_interactive_fd = 0;
8766 if (G_interactive_fd) {
8767 close_on_exec_on(G_interactive_fd);
8769 install_special_sighandlers();
8771 /* We have interactiveness code disabled */
8772 install_special_sighandlers();
8775 * if interactive but not a login shell, sources ~/.bashrc
8776 * (--norc turns this off, --rcfile <file> overrides)
8779 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8780 /* note: ash and hush share this string */
8781 printf("\n\n%s %s\n"
8782 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8785 "hush - the humble shell"
8789 parse_and_run_file(stdin);
8792 hush_exit(G.last_exitcode);
8797 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8798 int msh_main(int argc, char **argv)
8800 bb_error_msg("msh is deprecated, please use hush instead");
8801 return hush_main(argc, argv);
8809 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8814 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8821 return applet_main_func(argc, argv - argc);
8824 static int FAST_FUNC builtin_test(char **argv)
8826 return run_applet_main(argv, test_main);
8829 static int FAST_FUNC builtin_echo(char **argv)
8831 return run_applet_main(argv, echo_main);
8834 #if ENABLE_HUSH_PRINTF
8835 static int FAST_FUNC builtin_printf(char **argv)
8837 return run_applet_main(argv, printf_main);
8841 static char **skip_dash_dash(char **argv)
8844 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8849 static int FAST_FUNC builtin_eval(char **argv)
8851 int rcode = EXIT_SUCCESS;
8853 argv = skip_dash_dash(argv);
8855 char *str = expand_strvec_to_string(argv);
8857 * eval "echo Hi; done" ("done" is syntax error):
8858 * "echo Hi" will not execute too.
8860 parse_and_run_string(str);
8862 rcode = G.last_exitcode;
8867 static int FAST_FUNC builtin_cd(char **argv)
8871 argv = skip_dash_dash(argv);
8873 if (newdir == NULL) {
8874 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8875 * bash says "bash: cd: HOME not set" and does nothing
8878 const char *home = get_local_var_value("HOME");
8879 newdir = home ? home : "/";
8881 if (chdir(newdir)) {
8882 /* Mimic bash message exactly */
8883 bb_perror_msg("cd: %s", newdir);
8884 return EXIT_FAILURE;
8886 /* Read current dir (get_cwd(1) is inside) and set PWD.
8887 * Note: do not enforce exporting. If PWD was unset or unexported,
8888 * set it again, but do not export. bash does the same.
8890 set_pwd_var(/*exp:*/ 0);
8891 return EXIT_SUCCESS;
8894 static int FAST_FUNC builtin_exec(char **argv)
8896 argv = skip_dash_dash(argv);
8897 if (argv[0] == NULL)
8898 return EXIT_SUCCESS; /* bash does this */
8900 /* Careful: we can end up here after [v]fork. Do not restore
8901 * tty pgrp then, only top-level shell process does that */
8902 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8903 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8905 /* TODO: if exec fails, bash does NOT exit! We do.
8906 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8907 * and tcsetpgrp, and this is inherently racy.
8909 execvp_or_die(argv);
8912 static int FAST_FUNC builtin_exit(char **argv)
8914 debug_printf_exec("%s()\n", __func__);
8916 /* interactive bash:
8917 * # trap "echo EEE" EXIT
8920 * There are stopped jobs.
8921 * (if there are _stopped_ jobs, running ones don't count)
8924 * EEE (then bash exits)
8926 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8929 /* note: EXIT trap is run by hush_exit */
8930 argv = skip_dash_dash(argv);
8931 if (argv[0] == NULL)
8932 hush_exit(G.last_exitcode);
8933 /* mimic bash: exit 123abc == exit 255 + error msg */
8934 xfunc_error_retval = 255;
8935 /* bash: exit -2 == exit 254, no error msg */
8936 hush_exit(xatoi(argv[0]) & 0xff);
8939 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
8940 static void print_escaped(const char *s)
8945 const char *p = strchrnul(s, '\'');
8946 /* print 'xxxx', possibly just '' */
8947 printf("'%.*s'", (int)(p - s), s);
8952 /* s points to '; print "'''...'''" */
8954 do putchar('\''); while (*++s == '\'');
8960 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
8961 # if !ENABLE_HUSH_LOCAL
8962 #define helper_export_local(argv, exp, lvl) \
8963 helper_export_local(argv, exp)
8965 static void helper_export_local(char **argv, int exp, int lvl)
8969 char *name_end = strchrnul(name, '=');
8971 /* So far we do not check that name is valid (TODO?) */
8973 if (*name_end == '\0') {
8974 struct variable *var, **vpp;
8976 vpp = get_ptr_to_local_var(name, name_end - name);
8977 var = vpp ? *vpp : NULL;
8979 if (exp == -1) { /* unexporting? */
8980 /* export -n NAME (without =VALUE) */
8982 var->flg_export = 0;
8983 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8985 } /* else: export -n NOT_EXISTING_VAR: no-op */
8988 if (exp == 1) { /* exporting? */
8989 /* export NAME (without =VALUE) */
8991 var->flg_export = 1;
8992 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8993 putenv(var->varstr);
8997 # if ENABLE_HUSH_LOCAL
8998 if (exp == 0 /* local? */
8999 && var && var->func_nest_level == lvl
9001 /* "local x=abc; ...; local x" - ignore second local decl */
9005 /* Exporting non-existing variable.
9006 * bash does not put it in environment,
9007 * but remembers that it is exported,
9008 * and does put it in env when it is set later.
9009 * We just set it to "" and export. */
9010 /* Or, it's "local NAME" (without =VALUE).
9011 * bash sets the value to "". */
9012 name = xasprintf("%s=", name);
9014 /* (Un)exporting/making local NAME=VALUE */
9015 name = xstrdup(name);
9017 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9022 #if ENABLE_HUSH_EXPORT
9023 static int FAST_FUNC builtin_export(char **argv)
9025 unsigned opt_unexport;
9027 #if ENABLE_HUSH_EXPORT_N
9028 /* "!": do not abort on errors */
9029 opt_unexport = getopt32(argv, "!n");
9030 if (opt_unexport == (uint32_t)-1)
9031 return EXIT_FAILURE;
9038 if (argv[0] == NULL) {
9045 /* ash emits: export VAR='VAL'
9046 * bash: declare -x VAR="VAL"
9047 * we follow ash example */
9048 const char *s = *e++;
9049 const char *p = strchr(s, '=');
9051 if (!p) /* wtf? take next variable */
9054 printf("export %.*s", (int)(p - s) + 1, s);
9055 print_escaped(p + 1);
9059 /*fflush_all(); - done after each builtin anyway */
9061 return EXIT_SUCCESS;
9064 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9066 return EXIT_SUCCESS;
9070 #if ENABLE_HUSH_LOCAL
9071 static int FAST_FUNC builtin_local(char **argv)
9073 if (G.func_nest_level == 0) {
9074 bb_error_msg("%s: not in a function", argv[0]);
9075 return EXIT_FAILURE; /* bash compat */
9077 helper_export_local(argv, 0, G.func_nest_level);
9078 return EXIT_SUCCESS;
9082 #if ENABLE_HUSH_UNSET
9083 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9084 static int FAST_FUNC builtin_unset(char **argv)
9089 /* "!": do not abort on errors */
9090 /* "+": stop at 1st non-option */
9091 opts = getopt32(argv, "!+vf");
9092 if (opts == (unsigned)-1)
9093 return EXIT_FAILURE;
9095 bb_error_msg("unset: -v and -f are exclusive");
9096 return EXIT_FAILURE;
9102 if (!(opts & 2)) { /* not -f */
9103 if (unset_local_var(*argv)) {
9104 /* unset <nonexistent_var> doesn't fail.
9105 * Error is when one tries to unset RO var.
9106 * Message was printed by unset_local_var. */
9110 # if ENABLE_HUSH_FUNCTIONS
9122 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9123 * built-in 'set' handler
9125 * set [-abCefhmnuvx] [-o option] [argument...]
9126 * set [+abCefhmnuvx] [+o option] [argument...]
9127 * set -- [argument...]
9130 * Implementations shall support the options in both their hyphen and
9131 * plus-sign forms. These options can also be specified as options to sh.
9133 * Write out all variables and their values: set
9134 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9135 * Turn on the -x and -v options: set -xv
9136 * Unset all positional parameters: set --
9137 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9138 * Set the positional parameters to the expansion of x, even if x expands
9139 * with a leading '-' or '+': set -- $x
9141 * So far, we only support "set -- [argument...]" and some of the short names.
9143 static int FAST_FUNC builtin_set(char **argv)
9146 char **pp, **g_argv;
9147 char *arg = *++argv;
9151 for (e = G.top_var; e; e = e->next)
9153 return EXIT_SUCCESS;
9157 if (strcmp(arg, "--") == 0) {
9161 if (arg[0] != '+' && arg[0] != '-')
9163 for (n = 1; arg[n]; ++n) {
9164 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9166 if (arg[n] == 'o' && argv[1])
9169 } while ((arg = *++argv) != NULL);
9170 /* Now argv[0] is 1st argument */
9173 return EXIT_SUCCESS;
9176 /* NB: G.global_argv[0] ($0) is never freed/changed */
9177 g_argv = G.global_argv;
9178 if (G.global_args_malloced) {
9184 G.global_args_malloced = 1;
9185 pp = xzalloc(sizeof(pp[0]) * 2);
9186 pp[0] = g_argv[0]; /* retain $0 */
9189 /* This realloc's G.global_argv */
9190 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9197 return EXIT_SUCCESS;
9199 /* Nothing known, so abort */
9201 bb_error_msg("set: %s: invalid option", arg);
9202 return EXIT_FAILURE;
9206 static int FAST_FUNC builtin_shift(char **argv)
9209 argv = skip_dash_dash(argv);
9213 if (n >= 0 && n < G.global_argc) {
9214 if (G.global_args_malloced) {
9217 free(G.global_argv[m++]);
9220 memmove(&G.global_argv[1], &G.global_argv[n+1],
9221 G.global_argc * sizeof(G.global_argv[0]));
9222 return EXIT_SUCCESS;
9224 return EXIT_FAILURE;
9227 #if ENABLE_HUSH_READ
9228 /* Interruptibility of read builtin in bash
9229 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9231 * Empty trap makes read ignore corresponding signal, for any signal.
9234 * - terminates non-interactive shell;
9235 * - interrupts read in interactive shell;
9236 * if it has non-empty trap:
9237 * - executes trap and returns to command prompt in interactive shell;
9238 * - executes trap and returns to read in non-interactive shell;
9240 * - is ignored (does not interrupt) read in interactive shell;
9241 * - terminates non-interactive shell;
9242 * if it has non-empty trap:
9243 * - executes trap and returns to read;
9245 * - terminates shell (regardless of interactivity);
9246 * if it has non-empty trap:
9247 * - executes trap and returns to read;
9249 static int FAST_FUNC builtin_read(char **argv)
9259 /* "!": do not abort on errors.
9260 * Option string must start with "sr" to match BUILTIN_READ_xxx
9262 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9263 if (read_flags == (uint32_t)-1)
9264 return EXIT_FAILURE;
9266 ifs = get_local_var_value("IFS"); /* can be NULL */
9269 r = shell_builtin_read(set_local_var_from_halves,
9279 if ((uintptr_t)r == 1 && errno == EINTR) {
9280 unsigned sig = check_and_run_traps();
9281 if (sig && sig != SIGINT)
9285 if ((uintptr_t)r > 1) {
9286 bb_error_msg("%s", r);
9287 r = (char*)(uintptr_t)1;
9290 return (uintptr_t)r;
9294 #if ENABLE_HUSH_TRAP
9295 static int FAST_FUNC builtin_trap(char **argv)
9301 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9306 /* No args: print all trapped */
9307 for (i = 0; i < NSIG; ++i) {
9310 print_escaped(G_traps[i]);
9311 /* note: bash adds "SIG", but only if invoked
9312 * as "bash". If called as "sh", or if set -o posix,
9313 * then it prints short signal names.
9314 * We are printing short names: */
9315 printf(" %s\n", get_signame(i));
9318 /*fflush_all(); - done after each builtin anyway */
9319 return EXIT_SUCCESS;
9323 /* If first arg is a number: reset all specified signals */
9324 sig = bb_strtou(*argv, NULL, 10);
9330 sighandler_t handler;
9332 sig = get_signum(*argv++);
9333 if (sig < 0 || sig >= NSIG) {
9335 /* Mimic bash message exactly */
9336 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9341 G_traps[sig] = xstrdup(new_cmd);
9343 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9344 get_signame(sig), sig, G_traps[sig]);
9346 /* There is no signal for 0 (EXIT) */
9351 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9353 /* We are removing trap handler */
9354 handler = pick_sighandler(sig);
9355 install_sighandler(sig, handler);
9360 if (!argv[1]) { /* no second arg */
9361 bb_error_msg("trap: invalid arguments");
9362 return EXIT_FAILURE;
9365 /* First arg is "-": reset all specified to default */
9366 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9367 /* Everything else: set arg as signal handler
9368 * (includes "" case, which ignores signal) */
9369 if (argv[0][0] == '-') {
9370 if (argv[0][1] == '\0') { /* "-" */
9371 /* new_cmd remains NULL: "reset these sigs" */
9374 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9377 /* else: "-something", no special meaning */
9382 goto process_sig_list;
9386 #if ENABLE_HUSH_TYPE
9387 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9388 static int FAST_FUNC builtin_type(char **argv)
9390 int ret = EXIT_SUCCESS;
9396 if (0) {} /* make conditional compile easier below */
9397 /*else if (find_alias(*argv))
9398 type = "an alias";*/
9399 #if ENABLE_HUSH_FUNCTIONS
9400 else if (find_function(*argv))
9401 type = "a function";
9403 else if (find_builtin(*argv))
9404 type = "a shell builtin";
9405 else if ((path = find_in_path(*argv)) != NULL)
9408 bb_error_msg("type: %s: not found", *argv);
9413 printf("%s is %s\n", *argv, type);
9422 static struct pipe *parse_jobspec(const char *str)
9427 if (sscanf(str, "%%%u", &jobnum) != 1) {
9429 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9431 bb_error_msg("bad argument '%s'", str);
9434 /* It is "%%", "%+" or "%" - current job */
9435 jobnum = G.last_jobid;
9437 bb_error_msg("no current job");
9441 for (pi = G.job_list; pi; pi = pi->next) {
9442 if (pi->jobid == jobnum) {
9446 bb_error_msg("%u: no such job", jobnum);
9450 /* built-in 'fg' and 'bg' handler */
9451 static int FAST_FUNC builtin_fg_bg(char **argv)
9456 if (!G_interactive_fd)
9457 return EXIT_FAILURE;
9459 /* If they gave us no args, assume they want the last backgrounded task */
9461 for (pi = G.job_list; pi; pi = pi->next) {
9462 if (pi->jobid == G.last_jobid) {
9466 bb_error_msg("%s: no current job", argv[0]);
9467 return EXIT_FAILURE;
9470 pi = parse_jobspec(argv[1]);
9472 return EXIT_FAILURE;
9474 /* TODO: bash prints a string representation
9475 * of job being foregrounded (like "sleep 1 | cat") */
9476 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9477 /* Put the job into the foreground. */
9478 tcsetpgrp(G_interactive_fd, pi->pgrp);
9481 /* Restart the processes in the job */
9482 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9483 for (i = 0; i < pi->num_cmds; i++) {
9484 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9486 pi->stopped_cmds = 0;
9488 i = kill(- pi->pgrp, SIGCONT);
9490 if (errno == ESRCH) {
9491 delete_finished_bg_job(pi);
9492 return EXIT_SUCCESS;
9494 bb_perror_msg("kill (SIGCONT)");
9497 if (argv[0][0] == 'f') {
9499 return checkjobs_and_fg_shell(pi);
9501 return EXIT_SUCCESS;
9505 #if ENABLE_HUSH_HELP
9506 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9508 const struct built_in_command *x;
9511 "Built-in commands:\n"
9512 "------------------\n");
9513 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9515 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9517 return EXIT_SUCCESS;
9521 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9522 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9524 show_history(G.line_input_state);
9525 return EXIT_SUCCESS;
9530 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9533 const char *status_string;
9535 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9536 for (job = G.job_list; job; job = job->next) {
9537 if (job->alive_cmds == job->stopped_cmds)
9538 status_string = "Stopped";
9540 status_string = "Running";
9542 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9544 return EXIT_SUCCESS;
9548 #if ENABLE_HUSH_MEMLEAK
9549 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9554 # ifdef M_TRIM_THRESHOLD
9555 /* Optional. Reduces probability of false positives */
9558 /* Crude attempt to find where "free memory" starts,
9559 * sans fragmentation. */
9561 l = (unsigned long)p;
9564 if (l < (unsigned long)p) l = (unsigned long)p;
9570 struct mallinfo mi = mallinfo();
9571 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9572 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9576 if (!G.memleak_value)
9577 G.memleak_value = l;
9579 l -= G.memleak_value;
9586 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9591 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9594 return EXIT_SUCCESS;
9597 static int FAST_FUNC builtin_source(char **argv)
9599 char *arg_path, *filename;
9602 #if ENABLE_HUSH_FUNCTIONS
9606 argv = skip_dash_dash(argv);
9609 /* bash says: "bash: .: filename argument required" */
9610 return 2; /* bash compat */
9613 if (!strchr(filename, '/')) {
9614 arg_path = find_in_path(filename);
9616 filename = arg_path;
9618 input = remember_FILE(fopen_or_warn(filename, "r"));
9621 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9622 /* POSIX: non-interactive shell should abort here,
9623 * not merely fail. So far no one complained :)
9625 return EXIT_FAILURE;
9628 #if ENABLE_HUSH_FUNCTIONS
9629 sv_flg = G_flag_return_in_progress;
9630 /* "we are inside sourced file, ok to use return" */
9631 G_flag_return_in_progress = -1;
9634 save_and_replace_G_args(&sv, argv);
9636 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9637 G.last_exitcode = 0;
9638 parse_and_run_file(input);
9639 fclose_and_forget(input);
9642 restore_G_args(&sv, argv);
9643 #if ENABLE_HUSH_FUNCTIONS
9644 G_flag_return_in_progress = sv_flg;
9647 return G.last_exitcode;
9650 #if ENABLE_HUSH_UMASK
9651 static int FAST_FUNC builtin_umask(char **argv)
9658 argv = skip_dash_dash(argv);
9660 mode_t old_mask = mask;
9662 /* numeric umasks are taken as-is */
9663 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9664 if (!isdigit(argv[0][0]))
9666 mask = bb_parse_mode(argv[0], mask);
9667 if (!isdigit(argv[0][0]))
9669 if ((unsigned)mask > 0777) {
9672 * bash: umask: 'q': invalid symbolic mode operator
9673 * bash: umask: 999: octal number out of range
9675 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9680 printf("%04o\n", (unsigned) mask);
9681 /* fall through and restore mask which we set to 0 */
9685 return !rc; /* rc != 0 - success */
9689 #if ENABLE_HUSH_KILL
9690 static int FAST_FUNC builtin_kill(char **argv)
9694 # if ENABLE_HUSH_JOB
9695 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9703 if (argv[i][0] != '%')
9706 * "kill %N" - job kill
9707 * Converting to pgrp / pid kill
9709 pi = parse_jobspec(argv[i]);
9711 /* Eat bad jobspec */
9715 argv[j - 1] = argv[j];
9722 * In jobs started under job control, we signal
9723 * entire process group by kill -PGRP_ID.
9724 * This happens, f.e., in interactive shell.
9726 * Otherwise, we signal each child via
9727 * kill PID1 PID2 PID3.
9729 * sh -c 'sleep 1|sleep 1 & kill %1'
9730 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9731 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9733 n = G_interactive_fd ? 1 : pi->num_cmds;
9734 dst = alloca(n * sizeof(int)*4);
9736 if (G_interactive_fd)
9737 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9738 else for (j = 0; j < n; j++) {
9739 struct command *cmd = &pi->cmds[j];
9740 /* Skip exited members of the job */
9744 * kill_main has matching code to expect
9745 * leading space. Needed to not confuse
9746 * negative pids with "kill -SIGNAL_NO" syntax
9748 dst += sprintf(dst, " %u", (int)cmd->pid);
9751 } while (argv[++i]);
9755 if (argv[1] || ret == 0) {
9756 ret = run_applet_main(argv, kill_main);
9758 /* else: ret = 1, "kill %bad_jobspec" case */
9763 #if ENABLE_HUSH_WAIT
9764 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9765 #if !ENABLE_HUSH_JOB
9766 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9768 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9775 if (!sigisemptyset(&G.pending_set))
9778 /* waitpid is not interruptible by SA_RESTARTed
9779 * signals which we use. Thus, this ugly dance:
9782 /* Make sure possible SIGCHLD is stored in kernel's
9783 * pending signal mask before we call waitpid.
9784 * Or else we may race with SIGCHLD, lose it,
9785 * and get stuck in sigsuspend...
9787 sigfillset(&oldset); /* block all signals, remember old set */
9788 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9790 if (!sigisemptyset(&G.pending_set)) {
9791 /* Crap! we raced with some signal! */
9795 /*errno = 0; - checkjobs does this */
9796 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9797 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9798 debug_printf_exec("checkjobs:%d\n", ret);
9801 int rcode = job_exited_or_stopped(waitfor_pipe);
9802 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9805 sigprocmask(SIG_SETMASK, &oldset, NULL);
9810 /* if ECHILD, there are no children (ret is -1 or 0) */
9811 /* if ret == 0, no children changed state */
9812 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9813 if (errno == ECHILD || ret) {
9815 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9817 sigprocmask(SIG_SETMASK, &oldset, NULL);
9820 /* Wait for SIGCHLD or any other signal */
9821 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9822 /* Note: sigsuspend invokes signal handler */
9823 sigsuspend(&oldset);
9825 sigprocmask(SIG_SETMASK, &oldset, NULL);
9827 /* So, did we get a signal? */
9828 sig = check_and_run_traps();
9829 if (sig /*&& sig != SIGCHLD - always true */) {
9833 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9838 static int FAST_FUNC builtin_wait(char **argv)
9843 argv = skip_dash_dash(argv);
9844 if (argv[0] == NULL) {
9845 /* Don't care about wait results */
9846 /* Note 1: must wait until there are no more children */
9847 /* Note 2: must be interruptible */
9849 * $ sleep 3 & sleep 6 & wait
9854 * $ sleep 3 & sleep 6 & wait
9858 * ^C <-- after ~4 sec from keyboard
9861 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9865 pid_t pid = bb_strtou(*argv, NULL, 10);
9866 if (errno || pid <= 0) {
9868 if (argv[0][0] == '%') {
9869 struct pipe *wait_pipe;
9870 ret = 127; /* bash compat for bad jobspecs */
9871 wait_pipe = parse_jobspec(*argv);
9873 ret = job_exited_or_stopped(wait_pipe);
9875 ret = wait_for_child_or_signal(wait_pipe, 0);
9877 /* else: parse_jobspec() already emitted error msg */
9881 /* mimic bash message */
9882 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9884 continue; /* bash checks all argv[] */
9887 /* Do we have such child? */
9888 ret = waitpid(pid, &status, WNOHANG);
9891 if (errno == ECHILD) {
9892 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9893 /* "wait $!" but last bg task has already exited. Try:
9894 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9895 * In bash it prints exitcode 0, then 3.
9896 * In dash, it is 127.
9898 /* ret = G.last_bg_pid_exitstatus - FIXME */
9900 /* Example: "wait 1". mimic bash message */
9901 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9905 bb_perror_msg("wait %s", *argv);
9908 continue; /* bash checks all argv[] */
9911 /* Yes, and it still runs */
9912 ret = wait_for_child_or_signal(NULL, pid);
9914 /* Yes, and it just exited */
9915 process_wait_result(NULL, pid, status);
9916 ret = WEXITSTATUS(status);
9917 if (WIFSIGNALED(status))
9918 ret = 128 + WTERMSIG(status);
9926 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9927 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9930 def = bb_strtou(argv[1], NULL, 10);
9931 if (errno || def < def_min || argv[2]) {
9932 bb_error_msg("%s: bad arguments", argv[0]);
9940 #if ENABLE_HUSH_LOOPS
9941 static int FAST_FUNC builtin_break(char **argv)
9944 if (G.depth_of_loop == 0) {
9945 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9946 /* if we came from builtin_continue(), need to undo "= 1" */
9947 G.flag_break_continue = 0;
9948 return EXIT_SUCCESS; /* bash compat */
9950 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9952 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9953 if (depth == UINT_MAX)
9954 G.flag_break_continue = BC_BREAK;
9955 if (G.depth_of_loop < depth)
9956 G.depth_break_continue = G.depth_of_loop;
9958 return EXIT_SUCCESS;
9961 static int FAST_FUNC builtin_continue(char **argv)
9963 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9964 return builtin_break(argv);
9968 #if ENABLE_HUSH_FUNCTIONS
9969 static int FAST_FUNC builtin_return(char **argv)
9973 if (G_flag_return_in_progress != -1) {
9974 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9975 return EXIT_FAILURE; /* bash compat */
9978 G_flag_return_in_progress = 1;
9981 * out of range: wraps around at 256, does not error out
9982 * non-numeric param:
9983 * f() { false; return qwe; }; f; echo $?
9984 * bash: return: qwe: numeric argument required <== we do this
9985 * 255 <== we also do this
9987 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);