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 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * NB: so far, only naked "command CMD" is implemented.
62 * fc -l[nr] [BEG] [END]: list range of commands in history
63 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
64 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
67 * redirection of stdout+stderr: &> and >&
68 * reserved words: function select
69 * advanced test: [[ ]]
70 * process substitution: <(list) and >(list)
73 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
74 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
75 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
77 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
78 * This is exactly equivalent to let "EXPR".
79 * $[EXPR]: synonym for $((EXPR))
80 * indirect expansion: ${!VAR}
81 * substring op on @: ${@:n:m}
84 * Some builtins mandated by standards:
85 * newgrp [GRP]: not a builtin in bash but a suid binary
86 * which spawns a new shell with new group ID
87 * In bash, export builtin is special, its arguments are assignments
88 * and therefore expansion of them should be "one-word" expansion:
89 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
91 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
92 * ls: cannot access i=a: No such file or directory
93 * ls: cannot access b: No such file or directory
94 * Note1: same applies to local builtin.
95 * Note2: bash 3.2.33(1) does this only if export word itself
97 * $ export i=`echo 'aaa bbb'`; echo "$i"
99 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
103 //config: bool "hush (64 kb)"
106 //config: hush is a small shell. It handles the normal flow control
107 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
108 //config: case/esac. Redirections, here documents, $((arithmetic))
109 //config: and functions are supported.
111 //config: It will compile and work on no-mmu systems.
113 //config: It does not handle select, aliases, tilde expansion,
114 //config: &>file and >&file redirection of stdout+stderr.
116 //config:config HUSH_BASH_COMPAT
117 //config: bool "bash-compatible extensions"
119 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
121 //config:config HUSH_BRACE_EXPANSION
122 //config: bool "Brace expansion"
124 //config: depends on HUSH_BASH_COMPAT
126 //config: Enable {abc,def} extension.
128 //config:config HUSH_INTERACTIVE
129 //config: bool "Interactive mode"
131 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
133 //config: Enable interactive mode (prompt and command editing).
134 //config: Without this, hush simply reads and executes commands
135 //config: from stdin just like a shell script from a file.
136 //config: No prompt, no PS1/PS2 magic shell variables.
138 //config:config HUSH_SAVEHISTORY
139 //config: bool "Save command history to .hush_history"
141 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
143 //config:config HUSH_JOB
144 //config: bool "Job control"
146 //config: depends on HUSH_INTERACTIVE
148 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
149 //config: command (not entire shell), fg/bg builtins work. Without this option,
150 //config: "cmd &" still works by simply spawning a process and immediately
151 //config: prompting for next command (or executing next command in a script),
152 //config: but no separate process group is formed.
154 //config:config HUSH_TICK
155 //config: bool "Support process substitution"
157 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
159 //config: Enable `command` and $(command).
161 //config:config HUSH_IF
162 //config: bool "Support if/then/elif/else/fi"
164 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
166 //config:config HUSH_LOOPS
167 //config: bool "Support for, while and until loops"
169 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
171 //config:config HUSH_CASE
172 //config: bool "Support case ... esac statement"
174 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
176 //config: Enable case ... esac statement. +400 bytes.
178 //config:config HUSH_FUNCTIONS
179 //config: bool "Support funcname() { commands; } syntax"
181 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
183 //config: Enable support for shell functions. +800 bytes.
185 //config:config HUSH_LOCAL
186 //config: bool "local builtin"
188 //config: depends on HUSH_FUNCTIONS
190 //config: Enable support for local variables in functions.
192 //config:config HUSH_RANDOM_SUPPORT
193 //config: bool "Pseudorandom generator and $RANDOM variable"
195 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
197 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
198 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
200 //config:config HUSH_MODE_X
201 //config: bool "Support 'hush -x' option and 'set -x' command"
203 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
205 //config: This instructs hush to print commands before execution.
206 //config: Adds ~300 bytes.
208 //config:config HUSH_ECHO
209 //config: bool "echo builtin"
211 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
213 //config:config HUSH_PRINTF
214 //config: bool "printf builtin"
216 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
218 //config:config HUSH_TEST
219 //config: bool "test builtin"
221 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
223 //config:config HUSH_HELP
224 //config: bool "help builtin"
226 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
228 //config:config HUSH_EXPORT
229 //config: bool "export builtin"
231 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
233 //config:config HUSH_EXPORT_N
234 //config: bool "Support 'export -n' option"
236 //config: depends on HUSH_EXPORT
238 //config: export -n unexports variables. It is a bash extension.
240 //config:config HUSH_READONLY
241 //config: bool "readonly builtin"
243 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
245 //config: Enable support for read-only variables.
247 //config:config HUSH_KILL
248 //config: bool "kill builtin (supports kill %jobspec)"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config:config HUSH_WAIT
253 //config: bool "wait builtin"
255 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
257 //config:config HUSH_COMMAND
258 //config: bool "command builtin"
260 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
262 //config:config HUSH_TRAP
263 //config: bool "trap builtin"
265 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
267 //config:config HUSH_TYPE
268 //config: bool "type builtin"
270 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
272 //config:config HUSH_TIMES
273 //config: bool "times builtin"
275 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
277 //config:config HUSH_READ
278 //config: bool "read builtin"
280 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
282 //config:config HUSH_SET
283 //config: bool "set builtin"
285 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
287 //config:config HUSH_UNSET
288 //config: bool "unset builtin"
290 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
292 //config:config HUSH_ULIMIT
293 //config: bool "ulimit builtin"
295 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
297 //config:config HUSH_UMASK
298 //config: bool "umask builtin"
300 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
302 //config:config HUSH_GETOPTS
303 //config: bool "getopts builtin"
305 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
307 //config:config HUSH_MEMLEAK
308 //config: bool "memleak builtin (debugging)"
310 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
312 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
313 // APPLET_ODDNAME:name main location suid_type help
314 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
315 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
317 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
318 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
319 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
320 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
322 /* -i (interactive) and -s (read stdin) are also accepted,
323 * but currently do nothing, therefore aren't shown in help.
324 * NOMMU-specific options are not meant to be used by users,
325 * therefore we don't show them either.
327 //usage:#define hush_trivial_usage
328 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
329 //usage:#define hush_full_usage "\n\n"
330 //usage: "Unix shell interpreter"
332 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
333 || defined(__APPLE__) \
335 # include <malloc.h> /* for malloc_trim */
338 /* #include <dmalloc.h> */
340 # include <fnmatch.h>
342 #include <sys/times.h>
343 #include <sys/utsname.h> /* for setting $HOSTNAME */
345 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
347 #include "shell_common.h"
350 #if ENABLE_HUSH_RANDOM_SUPPORT
353 # define CLEAR_RANDOM_T(rnd) ((void)0)
355 #ifndef F_DUPFD_CLOEXEC
356 # define F_DUPFD_CLOEXEC F_DUPFD
359 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
363 /* So far, all bash compat is controlled by one config option */
364 /* Separate defines document which part of code implements what */
365 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
366 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
367 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
368 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
369 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
370 #define BASH_READ_D ENABLE_HUSH_BASH_COMPAT
374 #define LEAK_HUNTING 0
375 #define BUILD_AS_NOMMU 0
376 /* Enable/disable sanity checks. Ok to enable in production,
377 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
378 * Keeping 1 for now even in released versions.
381 /* Slightly bigger (+200 bytes), but faster hush.
382 * So far it only enables a trick with counting SIGCHLDs and forks,
383 * which allows us to do fewer waitpid's.
384 * (we can detect a case where neither forks were done nor SIGCHLDs happened
385 * and therefore waitpid will return the same result as last time)
387 #define ENABLE_HUSH_FAST 0
388 /* TODO: implement simplified code for users which do not need ${var%...} ops
389 * So far ${var%...} ops are always enabled:
391 #define ENABLE_HUSH_DOLLAR_OPS 1
396 # undef USE_FOR_NOMMU
399 # define USE_FOR_NOMMU(...) __VA_ARGS__
400 # define USE_FOR_MMU(...)
403 #include "NUM_APPLETS.h"
405 /* STANDALONE does not make sense, and won't compile */
406 # undef CONFIG_FEATURE_SH_STANDALONE
407 # undef ENABLE_FEATURE_SH_STANDALONE
408 # undef IF_FEATURE_SH_STANDALONE
409 # undef IF_NOT_FEATURE_SH_STANDALONE
410 # define ENABLE_FEATURE_SH_STANDALONE 0
411 # define IF_FEATURE_SH_STANDALONE(...)
412 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
415 #if !ENABLE_HUSH_INTERACTIVE
416 # undef ENABLE_FEATURE_EDITING
417 # define ENABLE_FEATURE_EDITING 0
418 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
419 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
420 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
421 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
424 /* Do we support ANY keywords? */
425 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
426 # define HAS_KEYWORDS 1
427 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
428 # define IF_HAS_NO_KEYWORDS(...)
430 # define HAS_KEYWORDS 0
431 # define IF_HAS_KEYWORDS(...)
432 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
435 /* If you comment out one of these below, it will be #defined later
436 * to perform debug printfs to stderr: */
437 #define debug_printf(...) do {} while (0)
438 /* Finer-grained debug switches */
439 #define debug_printf_parse(...) do {} while (0)
440 #define debug_print_tree(a, b) do {} while (0)
441 #define debug_printf_exec(...) do {} while (0)
442 #define debug_printf_env(...) do {} while (0)
443 #define debug_printf_jobs(...) do {} while (0)
444 #define debug_printf_expand(...) do {} while (0)
445 #define debug_printf_varexp(...) do {} while (0)
446 #define debug_printf_glob(...) do {} while (0)
447 #define debug_printf_redir(...) do {} while (0)
448 #define debug_printf_list(...) do {} while (0)
449 #define debug_printf_subst(...) do {} while (0)
450 #define debug_printf_clean(...) do {} while (0)
452 #define ERR_PTR ((void*)(long)1)
454 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
456 #define _SPECIAL_VARS_STR "_*@$!?#"
457 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
458 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
459 #if BASH_PATTERN_SUBST
460 /* Support / and // replace ops */
461 /* Note that // is stored as \ in "encoded" string representation */
462 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
463 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
464 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
466 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
467 # define VAR_SUBST_OPS "%#:-=+?"
468 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
471 #define SPECIAL_VAR_SYMBOL_STR "\3"
472 #define SPECIAL_VAR_SYMBOL 3
473 /* The "variable" with name "\1" emits string "\3". Testcase: "echo ^C" */
474 #define SPECIAL_VAR_QUOTED_SVS 1
478 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
480 /* This supports saving pointers malloced in vfork child,
481 * to be freed in the parent.
484 typedef struct nommu_save_t {
486 struct variable *old_vars;
488 char **argv_from_re_execing;
501 #if ENABLE_HUSH_LOOPS
508 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
513 /* three pseudo-keywords support contrived "case" syntax: */
514 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
515 RES_MATCH , /* "word)" */
516 RES_CASE_BODY, /* "this command is inside CASE" */
523 typedef struct o_string {
525 int length; /* position where data is appended */
528 /* At least some part of the string was inside '' or "",
529 * possibly empty one: word"", wo''rd etc. */
530 smallint has_quoted_part;
531 smallint has_empty_slot;
532 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
535 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
537 /* Protect newly added chars against globbing
538 * by prepending \ to *, ?, [, \ */
539 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
542 MAYBE_ASSIGNMENT = 0,
543 DEFINITELY_ASSIGNMENT = 1,
545 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
548 /* Used for initialization: o_string foo = NULL_O_STRING; */
549 #define NULL_O_STRING { NULL }
551 #ifndef debug_printf_parse
552 static const char *const assignment_flag[] = {
554 "DEFINITELY_ASSIGNMENT",
560 typedef struct in_str {
562 #if ENABLE_HUSH_INTERACTIVE
563 smallint promptmode; /* 0: PS1, 1: PS2 */
570 /* The descrip member of this structure is only used to make
571 * debugging output pretty */
572 static const struct {
574 signed char default_fd;
577 { O_RDONLY, 0, "<" },
578 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
579 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
580 { O_CREAT|O_RDWR, 1, "<>" },
581 { O_RDONLY, 0, "<<" },
582 /* Should not be needed. Bogus default_fd helps in debugging */
583 /* { O_RDONLY, 77, "<<" }, */
586 struct redir_struct {
587 struct redir_struct *next;
588 char *rd_filename; /* filename */
589 int rd_fd; /* fd to redirect */
590 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
592 smallint rd_type; /* (enum redir_type) */
593 /* note: for heredocs, rd_filename contains heredoc delimiter,
594 * and subsequently heredoc itself; and rd_dup is a bitmask:
595 * bit 0: do we need to trim leading tabs?
596 * bit 1: is heredoc quoted (<<'delim' syntax) ?
599 typedef enum redir_type {
601 REDIRECT_OVERWRITE = 1,
604 REDIRECT_HEREDOC = 4,
605 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
608 REDIRFD_SYNTAX_ERR = -2,
609 REDIRFD_TO_FILE = -1,
610 /* otherwise, rd_fd is redirected to rd_dup */
612 HEREDOC_SKIPTABS = 1,
618 pid_t pid; /* 0 if exited */
619 int assignment_cnt; /* how many argv[i] are assignments? */
620 smallint cmd_type; /* CMD_xxx */
622 #define CMD_SUBSHELL 1
624 /* used for "[[ EXPR ]]" */
625 # define CMD_SINGLEWORD_NOGLOB 2
627 #if ENABLE_HUSH_FUNCTIONS
628 # define CMD_FUNCDEF 3
631 smalluint cmd_exitcode;
632 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
635 char *group_as_string;
637 #if ENABLE_HUSH_FUNCTIONS
638 struct function *child_func;
639 /* This field is used to prevent a bug here:
640 * while...do f1() {a;}; f1; f1() {b;}; f1; done
641 * When we execute "f1() {a;}" cmd, we create new function and clear
642 * cmd->group, cmd->group_as_string, cmd->argv[0].
643 * When we execute "f1() {b;}", we notice that f1 exists,
644 * and that its "parent cmd" struct is still "alive",
645 * we put those fields back into cmd->xxx
646 * (struct function has ->parent_cmd ptr to facilitate that).
647 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
648 * Without this trick, loop would execute a;b;b;b;...
649 * instead of correct sequence a;b;a;b;...
650 * When command is freed, it severs the link
651 * (sets ->child_func->parent_cmd to NULL).
654 char **argv; /* command name and arguments */
655 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
656 * and on execution these are substituted with their values.
657 * Substitution can make _several_ words out of one argv[n]!
658 * Example: argv[0]=='.^C*^C.' here: echo .$*.
659 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
661 struct redir_struct *redirects; /* I/O redirections */
663 /* Is there anything in this command at all? */
664 #define IS_NULL_CMD(cmd) \
665 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
669 int num_cmds; /* total number of commands in pipe */
670 int alive_cmds; /* number of commands running (not exited) */
671 int stopped_cmds; /* number of commands alive, but stopped */
673 unsigned jobid; /* job number */
674 pid_t pgrp; /* process group ID for the job */
675 char *cmdtext; /* name of job */
677 struct command *cmds; /* array of commands in pipe */
678 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
679 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
680 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
682 typedef enum pipe_style {
688 /* Is there anything in this pipe at all? */
689 #define IS_NULL_PIPE(pi) \
690 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
692 /* This holds pointers to the various results of parsing */
693 struct parse_context {
694 /* linked list of pipes */
695 struct pipe *list_head;
696 /* last pipe (being constructed right now) */
698 /* last command in pipe (being constructed right now) */
699 struct command *command;
700 /* last redirect in command->redirects list */
701 struct redir_struct *pending_redirect;
707 smallint ctx_inverted; /* "! cmd | cmd" */
709 smallint ctx_dsemicolon; /* ";;" seen */
711 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
713 /* group we are enclosed in:
714 * example: "if pipe1; pipe2; then pipe3; fi"
715 * when we see "if" or "then", we malloc and copy current context,
716 * and make ->stack point to it. then we parse pipeN.
717 * when closing "then" / fi" / whatever is found,
718 * we move list_head into ->stack->command->group,
719 * copy ->stack into current context, and delete ->stack.
720 * (parsing of { list } and ( list ) doesn't use this method)
722 struct parse_context *stack;
726 /* On program start, environ points to initial environment.
727 * putenv adds new pointers into it, unsetenv removes them.
728 * Neither of these (de)allocates the strings.
729 * setenv allocates new strings in malloc space and does putenv,
730 * and thus setenv is unusable (leaky) for shell's purposes */
731 #define setenv(...) setenv_is_leaky_dont_use()
733 struct variable *next;
734 char *varstr; /* points to "name=" portion */
735 #if ENABLE_HUSH_LOCAL
736 unsigned func_nest_level;
738 int max_len; /* if > 0, name is part of initial env; else name is malloced */
739 smallint flg_export; /* putenv should be done on this var */
740 smallint flg_read_only;
748 #if ENABLE_HUSH_FUNCTIONS
750 struct function *next;
752 struct command *parent_cmd;
755 char *body_as_string;
761 /* set -/+o OPT support. (TODO: make it optional)
762 * bash supports the following opts:
773 * interactive-comments on
791 static const char o_opt_strings[] ALIGN1 =
795 #if ENABLE_HUSH_MODE_X
803 #if ENABLE_HUSH_MODE_X
811 struct FILE_list *next;
817 /* "Globals" within this file */
818 /* Sorted roughly by size (smaller offsets == smaller code) */
820 /* interactive_fd != 0 means we are an interactive shell.
821 * If we are, then saved_tty_pgrp can also be != 0, meaning
822 * that controlling tty is available. With saved_tty_pgrp == 0,
823 * job control still works, but terminal signals
824 * (^C, ^Z, ^Y, ^\) won't work at all, and background
825 * process groups can only be created with "cmd &".
826 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
827 * to give tty to the foreground process group,
828 * and will take it back when the group is stopped (^Z)
831 #if ENABLE_HUSH_INTERACTIVE
832 /* 'interactive_fd' is a fd# open to ctty, if we have one
833 * _AND_ if we decided to act interactively */
837 # define G_interactive_fd (G.interactive_fd)
839 # define G_interactive_fd 0
841 #if ENABLE_FEATURE_EDITING
842 line_input_t *line_input_state;
847 #if ENABLE_HUSH_RANDOM_SUPPORT
853 pid_t saved_tty_pgrp;
854 struct pipe *job_list;
855 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
857 # define G_saved_tty_pgrp 0
859 /* How deeply are we in context where "set -e" is ignored */
861 /* "set -e" rules (do we follow them correctly?):
862 * Exit if pipe, list, or compound command exits with a non-zero status.
863 * Shell does not exit if failed command is part of condition in
864 * if/while, part of && or || list except the last command, any command
865 * in a pipe but the last, or if the command's return value is being
866 * inverted with !. If a compound command other than a subshell returns a
867 * non-zero status because a command failed while -e was being ignored, the
868 * shell does not exit. A trap on ERR, if set, is executed before the shell
869 * exits [ERR is a bashism].
871 * If a compound command or function executes in a context where -e is
872 * ignored, none of the commands executed within are affected by the -e
873 * setting. If a compound command or function sets -e while executing in a
874 * context where -e is ignored, that setting does not have any effect until
875 * the compound command or the command containing the function call completes.
878 char o_opt[NUM_OPT_O];
879 #if ENABLE_HUSH_MODE_X
880 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
884 smallint flag_SIGINT;
885 #if ENABLE_HUSH_LOOPS
886 smallint flag_break_continue;
888 #if ENABLE_HUSH_FUNCTIONS
889 /* 0: outside of a function (or sourced file)
890 * -1: inside of a function, ok to use return builtin
891 * 1: return is invoked, skip all till end of func
893 smallint flag_return_in_progress;
894 # define G_flag_return_in_progress (G.flag_return_in_progress)
896 # define G_flag_return_in_progress 0
898 smallint exiting; /* used to prevent EXIT trap recursion */
899 /* These four support $?, $#, and $1 */
900 smalluint last_exitcode;
901 smalluint last_bg_pid_exitcode;
903 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
904 smalluint global_args_malloced;
905 # define G_global_args_malloced (G.global_args_malloced)
907 # define G_global_args_malloced 0
909 /* how many non-NULL argv's we have. NB: $# + 1 */
913 char *argv0_for_re_execing;
915 #if ENABLE_HUSH_LOOPS
916 unsigned depth_break_continue;
917 unsigned depth_of_loop;
919 #if ENABLE_HUSH_GETOPTS
920 unsigned getopt_count;
924 struct variable *top_var;
925 char **expanded_assignments;
926 #if ENABLE_HUSH_FUNCTIONS
927 struct function *top_func;
928 # if ENABLE_HUSH_LOCAL
929 struct variable **shadowed_vars_pp;
930 unsigned func_nest_level;
933 /* Signal and trap handling */
935 unsigned count_SIGCHLD;
936 unsigned handled_SIGCHLD;
937 smallint we_have_children;
939 struct FILE_list *FILE_list;
940 /* Which signals have non-DFL handler (even with no traps set)?
941 * Set at the start to:
942 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
943 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
944 * The rest is cleared right before execv syscalls.
945 * Other than these two times, never modified.
947 unsigned special_sig_mask;
949 unsigned fatal_sig_mask;
950 # define G_fatal_sig_mask (G.fatal_sig_mask)
952 # define G_fatal_sig_mask 0
955 char **traps; /* char *traps[NSIG] */
956 # define G_traps G.traps
958 # define G_traps ((char**)NULL)
960 sigset_t pending_set;
961 #if ENABLE_HUSH_MEMLEAK
962 unsigned long memleak_value;
968 #if ENABLE_FEATURE_EDITING
969 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
972 #define G (*ptr_to_globals)
973 /* Not #defining name to G.name - this quickly gets unwieldy
974 * (too many defines). Also, I actually prefer to see when a variable
975 * is global, thus "G." prefix is a useful hint */
976 #define INIT_G() do { \
977 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
978 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
979 sigfillset(&G.sa.sa_mask); \
980 G.sa.sa_flags = SA_RESTART; \
984 /* Function prototypes for builtins */
985 static int builtin_cd(char **argv) FAST_FUNC;
987 static int builtin_echo(char **argv) FAST_FUNC;
989 static int builtin_eval(char **argv) FAST_FUNC;
990 static int builtin_exec(char **argv) FAST_FUNC;
991 static int builtin_exit(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_EXPORT
993 static int builtin_export(char **argv) FAST_FUNC;
995 #if ENABLE_HUSH_READONLY
996 static int builtin_readonly(char **argv) FAST_FUNC;
999 static int builtin_fg_bg(char **argv) FAST_FUNC;
1000 static int builtin_jobs(char **argv) FAST_FUNC;
1002 #if ENABLE_HUSH_GETOPTS
1003 static int builtin_getopts(char **argv) FAST_FUNC;
1005 #if ENABLE_HUSH_HELP
1006 static int builtin_help(char **argv) FAST_FUNC;
1008 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1009 static int builtin_history(char **argv) FAST_FUNC;
1011 #if ENABLE_HUSH_LOCAL
1012 static int builtin_local(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_MEMLEAK
1015 static int builtin_memleak(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_PRINTF
1018 static int builtin_printf(char **argv) FAST_FUNC;
1020 static int builtin_pwd(char **argv) FAST_FUNC;
1021 #if ENABLE_HUSH_READ
1022 static int builtin_read(char **argv) FAST_FUNC;
1025 static int builtin_set(char **argv) FAST_FUNC;
1027 static int builtin_shift(char **argv) FAST_FUNC;
1028 static int builtin_source(char **argv) FAST_FUNC;
1029 #if ENABLE_HUSH_TEST || BASH_TEST2
1030 static int builtin_test(char **argv) FAST_FUNC;
1032 #if ENABLE_HUSH_TRAP
1033 static int builtin_trap(char **argv) FAST_FUNC;
1035 #if ENABLE_HUSH_TYPE
1036 static int builtin_type(char **argv) FAST_FUNC;
1038 #if ENABLE_HUSH_TIMES
1039 static int builtin_times(char **argv) FAST_FUNC;
1041 static int builtin_true(char **argv) FAST_FUNC;
1042 #if ENABLE_HUSH_UMASK
1043 static int builtin_umask(char **argv) FAST_FUNC;
1045 #if ENABLE_HUSH_UNSET
1046 static int builtin_unset(char **argv) FAST_FUNC;
1048 #if ENABLE_HUSH_KILL
1049 static int builtin_kill(char **argv) FAST_FUNC;
1051 #if ENABLE_HUSH_WAIT
1052 static int builtin_wait(char **argv) FAST_FUNC;
1054 #if ENABLE_HUSH_LOOPS
1055 static int builtin_break(char **argv) FAST_FUNC;
1056 static int builtin_continue(char **argv) FAST_FUNC;
1058 #if ENABLE_HUSH_FUNCTIONS
1059 static int builtin_return(char **argv) FAST_FUNC;
1062 /* Table of built-in functions. They can be forked or not, depending on
1063 * context: within pipes, they fork. As simple commands, they do not.
1064 * When used in non-forking context, they can change global variables
1065 * in the parent shell process. If forked, of course they cannot.
1066 * For example, 'unset foo | whatever' will parse and run, but foo will
1067 * still be set at the end. */
1068 struct built_in_command {
1070 int (*b_function)(char **argv) FAST_FUNC;
1071 #if ENABLE_HUSH_HELP
1072 const char *b_descr;
1073 # define BLTIN(cmd, func, help) { cmd, func, help }
1075 # define BLTIN(cmd, func, help) { cmd, func }
1079 static const struct built_in_command bltins1[] = {
1080 BLTIN("." , builtin_source , "Run commands in file"),
1081 BLTIN(":" , builtin_true , NULL),
1083 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1085 #if ENABLE_HUSH_LOOPS
1086 BLTIN("break" , builtin_break , "Exit loop"),
1088 BLTIN("cd" , builtin_cd , "Change directory"),
1089 #if ENABLE_HUSH_LOOPS
1090 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1092 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1093 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1094 BLTIN("exit" , builtin_exit , NULL),
1095 #if ENABLE_HUSH_EXPORT
1096 BLTIN("export" , builtin_export , "Set environment variables"),
1099 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1101 #if ENABLE_HUSH_GETOPTS
1102 BLTIN("getopts" , builtin_getopts , NULL),
1104 #if ENABLE_HUSH_HELP
1105 BLTIN("help" , builtin_help , NULL),
1107 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1108 BLTIN("history" , builtin_history , "Show history"),
1111 BLTIN("jobs" , builtin_jobs , "List jobs"),
1113 #if ENABLE_HUSH_KILL
1114 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1116 #if ENABLE_HUSH_LOCAL
1117 BLTIN("local" , builtin_local , "Set local variables"),
1119 #if ENABLE_HUSH_MEMLEAK
1120 BLTIN("memleak" , builtin_memleak , NULL),
1122 #if ENABLE_HUSH_READ
1123 BLTIN("read" , builtin_read , "Input into variable"),
1125 #if ENABLE_HUSH_READONLY
1126 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1128 #if ENABLE_HUSH_FUNCTIONS
1129 BLTIN("return" , builtin_return , "Return from function"),
1132 BLTIN("set" , builtin_set , "Set positional parameters"),
1134 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1136 BLTIN("source" , builtin_source , NULL),
1138 #if ENABLE_HUSH_TIMES
1139 BLTIN("times" , builtin_times , NULL),
1141 #if ENABLE_HUSH_TRAP
1142 BLTIN("trap" , builtin_trap , "Trap signals"),
1144 BLTIN("true" , builtin_true , NULL),
1145 #if ENABLE_HUSH_TYPE
1146 BLTIN("type" , builtin_type , "Show command type"),
1148 #if ENABLE_HUSH_ULIMIT
1149 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1151 #if ENABLE_HUSH_UMASK
1152 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1154 #if ENABLE_HUSH_UNSET
1155 BLTIN("unset" , builtin_unset , "Unset variables"),
1157 #if ENABLE_HUSH_WAIT
1158 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1161 /* These builtins won't be used if we are on NOMMU and need to re-exec
1162 * (it's cheaper to run an external program in this case):
1164 static const struct built_in_command bltins2[] = {
1165 #if ENABLE_HUSH_TEST
1166 BLTIN("[" , builtin_test , NULL),
1169 BLTIN("[[" , builtin_test , NULL),
1171 #if ENABLE_HUSH_ECHO
1172 BLTIN("echo" , builtin_echo , NULL),
1174 #if ENABLE_HUSH_PRINTF
1175 BLTIN("printf" , builtin_printf , NULL),
1177 BLTIN("pwd" , builtin_pwd , NULL),
1178 #if ENABLE_HUSH_TEST
1179 BLTIN("test" , builtin_test , NULL),
1187 /* prevent disasters with G.debug_indent < 0 */
1188 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1189 # define debug_enter() (G.debug_indent++)
1190 # define debug_leave() (G.debug_indent--)
1192 # define indent() ((void)0)
1193 # define debug_enter() ((void)0)
1194 # define debug_leave() ((void)0)
1197 #ifndef debug_printf
1198 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1201 #ifndef debug_printf_parse
1202 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1205 #ifndef debug_printf_exec
1206 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1209 #ifndef debug_printf_env
1210 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1213 #ifndef debug_printf_jobs
1214 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1215 # define DEBUG_JOBS 1
1217 # define DEBUG_JOBS 0
1220 #ifndef debug_printf_expand
1221 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1222 # define DEBUG_EXPAND 1
1224 # define DEBUG_EXPAND 0
1227 #ifndef debug_printf_varexp
1228 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1231 #ifndef debug_printf_glob
1232 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1233 # define DEBUG_GLOB 1
1235 # define DEBUG_GLOB 0
1238 #ifndef debug_printf_redir
1239 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1242 #ifndef debug_printf_list
1243 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1246 #ifndef debug_printf_subst
1247 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1250 #ifndef debug_printf_clean
1251 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1252 # define DEBUG_CLEAN 1
1254 # define DEBUG_CLEAN 0
1258 static void debug_print_strings(const char *prefix, char **vv)
1261 fdprintf(2, "%s:\n", prefix);
1263 fdprintf(2, " '%s'\n", *vv++);
1266 # define debug_print_strings(prefix, vv) ((void)0)
1270 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1273 static void *xxmalloc(int lineno, size_t size)
1275 void *ptr = xmalloc((size + 0xff) & ~0xff);
1276 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1279 static void *xxrealloc(int lineno, void *ptr, size_t size)
1281 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1282 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1285 static char *xxstrdup(int lineno, const char *str)
1287 char *ptr = xstrdup(str);
1288 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1291 static void xxfree(void *ptr)
1293 fdprintf(2, "free %p\n", ptr);
1296 # define xmalloc(s) xxmalloc(__LINE__, s)
1297 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1298 # define xstrdup(s) xxstrdup(__LINE__, s)
1299 # define free(p) xxfree(p)
1303 /* Syntax and runtime errors. They always abort scripts.
1304 * In interactive use they usually discard unparsed and/or unexecuted commands
1305 * and return to the prompt.
1306 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1309 # define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__)
1310 # define syntax_error(lineno, msg) syntax_error(msg)
1311 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1312 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1313 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1314 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1317 static void die_if_script(void)
1319 if (!G_interactive_fd) {
1320 if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
1321 xfunc_error_retval = G.last_exitcode;
1326 static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
1331 bb_error_msg("hush.c:%u", lineno);
1334 bb_verror_msg(fmt, p, NULL);
1339 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1342 bb_error_msg("syntax error: %s", msg);
1344 bb_error_msg("syntax error");
1348 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1350 bb_error_msg("syntax error at '%s'", msg);
1354 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1356 bb_error_msg("syntax error: unterminated %s", s);
1357 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
1361 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1363 char msg[2] = { ch, '\0' };
1364 syntax_error_unterm_str(lineno, msg);
1367 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1373 bb_error_msg("hush.c:%u", lineno);
1375 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1380 # undef msg_and_die_if_script
1381 # undef syntax_error
1382 # undef syntax_error_at
1383 # undef syntax_error_unterm_ch
1384 # undef syntax_error_unterm_str
1385 # undef syntax_error_unexpected_ch
1387 # define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
1388 # define syntax_error(msg) syntax_error(__LINE__, msg)
1389 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1390 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1391 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1392 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1396 #if ENABLE_HUSH_INTERACTIVE
1397 static void cmdedit_update_prompt(void);
1399 # define cmdedit_update_prompt() ((void)0)
1403 /* Utility functions
1405 /* Replace each \x with x in place, return ptr past NUL. */
1406 static char *unbackslash(char *src)
1408 char *dst = src = strchrnul(src, '\\');
1412 if ((*dst++ = *src++) == '\0')
1418 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1439 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1440 v[count1 + count2] = NULL;
1443 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1447 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1449 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1450 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1453 #define add_strings_to_strings(strings, add, need_to_dup) \
1454 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1457 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1458 static char **add_string_to_strings(char **strings, char *add)
1463 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1466 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1468 char **ptr = add_string_to_strings(strings, add);
1469 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1472 #define add_string_to_strings(strings, add) \
1473 xx_add_string_to_strings(__LINE__, strings, add)
1476 static void free_strings(char **strings)
1490 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1494 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1504 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1508 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1514 /* fd was not open? */
1519 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1520 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1526 /* Manipulating the list of open FILEs */
1527 static FILE *remember_FILE(FILE *fp)
1530 struct FILE_list *n = xmalloc(sizeof(*n));
1531 n->next = G.FILE_list;
1535 close_on_exec_on(n->fd);
1539 static void fclose_and_forget(FILE *fp)
1541 struct FILE_list **pp = &G.FILE_list;
1543 struct FILE_list *cur = *pp;
1544 if (cur->fp == fp) {
1553 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1555 struct FILE_list *fl = G.FILE_list;
1558 /* We use it only on script files, they are all CLOEXEC */
1559 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1560 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1567 static void restore_redirected_FILEs(void)
1569 struct FILE_list *fl = G.FILE_list;
1571 int should_be = fileno(fl->fp);
1572 if (fl->fd != should_be) {
1573 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1574 xmove_fd(fl->fd, should_be);
1580 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1581 static void close_all_FILE_list(void)
1583 struct FILE_list *fl = G.FILE_list;
1585 /* fclose would also free FILE object.
1586 * It is disastrous if we share memory with a vforked parent.
1587 * I'm not sure we never come here after vfork.
1588 * Therefore just close fd, nothing more.
1590 /*fclose(fl->fp); - unsafe */
1596 static int fd_in_FILEs(int fd)
1598 struct FILE_list *fl = G.FILE_list;
1608 /* Helpers for setting new $n and restoring them back
1610 typedef struct save_arg_t {
1614 IF_HUSH_SET(smallint sv_g_malloced;)
1617 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1619 sv->sv_argv0 = argv[0];
1620 sv->sv_g_argv = G.global_argv;
1621 sv->sv_g_argc = G.global_argc;
1622 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1624 argv[0] = G.global_argv[0]; /* retain $0 */
1625 G.global_argv = argv;
1626 IF_HUSH_SET(G.global_args_malloced = 0;)
1628 G.global_argc = 1 + string_array_len(argv + 1);
1631 static void restore_G_args(save_arg_t *sv, char **argv)
1634 if (G.global_args_malloced) {
1635 /* someone ran "set -- arg1 arg2 ...", undo */
1636 char **pp = G.global_argv;
1637 while (*++pp) /* note: does not free $0 */
1639 free(G.global_argv);
1642 argv[0] = sv->sv_argv0;
1643 G.global_argv = sv->sv_g_argv;
1644 G.global_argc = sv->sv_g_argc;
1645 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1649 /* Basic theory of signal handling in shell
1650 * ========================================
1651 * This does not describe what hush does, rather, it is current understanding
1652 * what it _should_ do. If it doesn't, it's a bug.
1653 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1655 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1656 * is finished or backgrounded. It is the same in interactive and
1657 * non-interactive shells, and is the same regardless of whether
1658 * a user trap handler is installed or a shell special one is in effect.
1659 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1660 * backgrounds (i.e. stops) or kills all members of currently running
1663 * Wait builtin is interruptible by signals for which user trap is set
1664 * or by SIGINT in interactive shell.
1666 * Trap handlers will execute even within trap handlers. (right?)
1668 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1669 * except for handlers set to '' (empty string).
1671 * If job control is off, backgrounded commands ("cmd &")
1672 * have SIGINT, SIGQUIT set to SIG_IGN.
1674 * Commands which are run in command substitution ("`cmd`")
1675 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1677 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1678 * by the shell from its parent.
1680 * Signals which differ from SIG_DFL action
1681 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1684 * SIGTERM (interactive): ignore
1685 * SIGHUP (interactive):
1686 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1687 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1688 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1689 * that all pipe members are stopped. Try this in bash:
1690 * while :; do :; done - ^Z does not background it
1691 * (while :; do :; done) - ^Z backgrounds it
1692 * SIGINT (interactive): wait for last pipe, ignore the rest
1693 * of the command line, show prompt. NB: ^C does not send SIGINT
1694 * to interactive shell while shell is waiting for a pipe,
1695 * since shell is bg'ed (is not in foreground process group).
1696 * Example 1: this waits 5 sec, but does not execute ls:
1697 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1698 * Example 2: this does not wait and does not execute ls:
1699 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1700 * Example 3: this does not wait 5 sec, but executes ls:
1701 * "sleep 5; ls -l" + press ^C
1702 * Example 4: this does not wait and does not execute ls:
1703 * "sleep 5 & wait; ls -l" + press ^C
1705 * (What happens to signals which are IGN on shell start?)
1706 * (What happens with signal mask on shell start?)
1708 * Old implementation
1709 * ==================
1710 * We use in-kernel pending signal mask to determine which signals were sent.
1711 * We block all signals which we don't want to take action immediately,
1712 * i.e. we block all signals which need to have special handling as described
1713 * above, and all signals which have traps set.
1714 * After each pipe execution, we extract any pending signals via sigtimedwait()
1717 * unsigned special_sig_mask: a mask of such "special" signals
1718 * sigset_t blocked_set: current blocked signal set
1721 * clear bit in blocked_set unless it is also in special_sig_mask
1722 * "trap 'cmd' SIGxxx":
1723 * set bit in blocked_set (even if 'cmd' is '')
1724 * after [v]fork, if we plan to be a shell:
1725 * unblock signals with special interactive handling
1726 * (child shell is not interactive),
1727 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1728 * after [v]fork, if we plan to exec:
1729 * POSIX says fork clears pending signal mask in child - no need to clear it.
1730 * Restore blocked signal set to one inherited by shell just prior to exec.
1732 * Note: as a result, we do not use signal handlers much. The only uses
1733 * are to count SIGCHLDs
1734 * and to restore tty pgrp on signal-induced exit.
1737 * Standard says "When a subshell is entered, traps that are not being ignored
1738 * are set to the default actions". bash interprets it so that traps which
1739 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1741 * Problem: the above approach makes it unwieldy to catch signals while
1742 * we are in read builtin, or while we read commands from stdin:
1743 * masked signals are not visible!
1745 * New implementation
1746 * ==================
1747 * We record each signal we are interested in by installing signal handler
1748 * for them - a bit like emulating kernel pending signal mask in userspace.
1749 * We are interested in: signals which need to have special handling
1750 * as described above, and all signals which have traps set.
1751 * Signals are recorded in pending_set.
1752 * After each pipe execution, we extract any pending signals
1755 * unsigned special_sig_mask: a mask of shell-special signals.
1756 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1757 * char *traps[sig] if trap for sig is set (even if it's '').
1758 * sigset_t pending_set: set of sigs we received.
1761 * if sig is in special_sig_mask, set handler back to:
1762 * record_pending_signo, or to IGN if it's a tty stop signal
1763 * if sig is in fatal_sig_mask, set handler back to sigexit.
1764 * else: set handler back to SIG_DFL
1765 * "trap 'cmd' SIGxxx":
1766 * set handler to record_pending_signo.
1768 * set handler to SIG_IGN.
1769 * after [v]fork, if we plan to be a shell:
1770 * set signals with special interactive handling to SIG_DFL
1771 * (because child shell is not interactive),
1772 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1773 * after [v]fork, if we plan to exec:
1774 * POSIX says fork clears pending signal mask in child - no need to clear it.
1776 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1777 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1780 * Standard says "When a subshell is entered, traps that are not being ignored
1781 * are set to the default actions". bash interprets it so that traps which
1782 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1785 SPECIAL_INTERACTIVE_SIGS = 0
1790 SPECIAL_JOBSTOP_SIGS = 0
1799 static void record_pending_signo(int sig)
1801 sigaddset(&G.pending_set, sig);
1802 #if ENABLE_HUSH_FAST
1803 if (sig == SIGCHLD) {
1805 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1810 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1812 struct sigaction old_sa;
1814 /* We could use signal() to install handlers... almost:
1815 * except that we need to mask ALL signals while handlers run.
1816 * I saw signal nesting in strace, race window isn't small.
1817 * SA_RESTART is also needed, but in Linux, signal()
1818 * sets SA_RESTART too.
1820 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1821 /* sigfillset(&G.sa.sa_mask); - already done */
1822 /* G.sa.sa_flags = SA_RESTART; - already done */
1823 G.sa.sa_handler = handler;
1824 sigaction(sig, &G.sa, &old_sa);
1825 return old_sa.sa_handler;
1828 static void hush_exit(int exitcode) NORETURN;
1830 static void restore_ttypgrp_and__exit(void) NORETURN;
1831 static void restore_ttypgrp_and__exit(void)
1833 /* xfunc has failed! die die die */
1834 /* no EXIT traps, this is an escape hatch! */
1836 hush_exit(xfunc_error_retval);
1841 /* Needed only on some libc:
1842 * It was observed that on exit(), fgetc'ed buffered data
1843 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1844 * With the net effect that even after fork(), not vfork(),
1845 * exit() in NOEXECed applet in "sh SCRIPT":
1846 * noexec_applet_here
1847 * echo END_OF_SCRIPT
1848 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1849 * This makes "echo END_OF_SCRIPT" executed twice.
1850 * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
1851 * and in `cmd` handling.
1852 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1854 static void fflush_and__exit(void) NORETURN;
1855 static void fflush_and__exit(void)
1858 _exit(xfunc_error_retval);
1861 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1862 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1863 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1864 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1866 /* Restores tty foreground process group, and exits.
1867 * May be called as signal handler for fatal signal
1868 * (will resend signal to itself, producing correct exit state)
1869 * or called directly with -EXITCODE.
1870 * We also call it if xfunc is exiting.
1872 static void sigexit(int sig) NORETURN;
1873 static void sigexit(int sig)
1875 /* Careful: we can end up here after [v]fork. Do not restore
1876 * tty pgrp then, only top-level shell process does that */
1877 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1878 /* Disable all signals: job control, SIGPIPE, etc.
1879 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1881 sigprocmask_allsigs(SIG_BLOCK);
1882 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1885 /* Not a signal, just exit */
1889 kill_myself_with_sig(sig); /* does not return */
1893 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1894 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1898 static sighandler_t pick_sighandler(unsigned sig)
1900 sighandler_t handler = SIG_DFL;
1901 if (sig < sizeof(unsigned)*8) {
1902 unsigned sigmask = (1 << sig);
1906 if (G_fatal_sig_mask & sigmask)
1910 /* sig has special handling? */
1911 if (G.special_sig_mask & sigmask) {
1912 handler = record_pending_signo;
1913 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1914 * in order to ignore them: they will be raised
1915 * in an endless loop when we try to do some
1916 * terminal ioctls! We do have to _ignore_ these.
1918 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1925 /* Restores tty foreground process group, and exits. */
1926 static void hush_exit(int exitcode)
1928 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1929 save_history(G.line_input_state);
1933 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1935 /* argv[0] is unused */
1936 argv[1] = G_traps[0];
1938 G.exiting = 1; /* prevent EXIT trap recursion */
1939 /* Note: G_traps[0] is not cleared!
1940 * "trap" will still show it, if executed
1945 #if ENABLE_FEATURE_CLEAN_UP
1947 struct variable *cur_var;
1948 if (G.cwd != bb_msg_unknown)
1950 cur_var = G.top_var;
1952 struct variable *tmp = cur_var;
1953 if (!cur_var->max_len)
1954 free(cur_var->varstr);
1955 cur_var = cur_var->next;
1963 sigexit(- (exitcode & 0xff));
1970 //TODO: return a mask of ALL handled sigs?
1971 static int check_and_run_traps(void)
1978 if (sigisemptyset(&G.pending_set))
1983 if (sigismember(&G.pending_set, sig)) {
1984 sigdelset(&G.pending_set, sig);
1987 } while (sig < NSIG);
1990 if (G_traps && G_traps[sig]) {
1991 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1992 if (G_traps[sig][0]) {
1993 /* We have user-defined handler */
1994 smalluint save_rcode;
1996 /* argv[0] is unused */
1997 argv[1] = G_traps[sig];
1999 save_rcode = G.last_exitcode;
2001 //FIXME: shouldn't it be set to 128 + sig instead?
2002 G.last_exitcode = save_rcode;
2004 } /* else: "" trap, ignoring signal */
2007 /* not a trap: special action */
2010 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
2016 //TODO: why are we doing this? ash and dash don't do this,
2017 //they have no handler for SIGHUP at all,
2018 //they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
2020 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
2021 /* bash is observed to signal whole process groups,
2022 * not individual processes */
2023 for (job = G.job_list; job; job = job->next) {
2026 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
2027 if (kill(- job->pgrp, SIGHUP) == 0)
2028 kill(- job->pgrp, SIGCONT);
2033 #if ENABLE_HUSH_FAST
2035 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
2037 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2039 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2040 * This simplifies wait builtin a bit.
2044 default: /* ignored: */
2045 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
2046 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
2048 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2049 * Example: wait is not interrupted by TERM
2050 * in interactive shell, because TERM is ignored.
2059 static const char *get_cwd(int force)
2061 if (force || G.cwd == NULL) {
2062 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2063 * we must not try to free(bb_msg_unknown) */
2064 if (G.cwd == bb_msg_unknown)
2066 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2068 G.cwd = bb_msg_unknown;
2075 * Shell and environment variable support
2077 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2079 struct variable **pp;
2080 struct variable *cur;
2083 while ((cur = *pp) != NULL) {
2084 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2091 static const char* FAST_FUNC get_local_var_value(const char *name)
2093 struct variable **vpp;
2094 unsigned len = strlen(name);
2096 if (G.expanded_assignments) {
2097 char **cpp = G.expanded_assignments;
2100 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2101 return cp + len + 1;
2106 vpp = get_ptr_to_local_var(name, len);
2108 return (*vpp)->varstr + len + 1;
2110 if (strcmp(name, "PPID") == 0)
2111 return utoa(G.root_ppid);
2112 // bash compat: UID? EUID?
2113 #if ENABLE_HUSH_RANDOM_SUPPORT
2114 if (strcmp(name, "RANDOM") == 0)
2115 return utoa(next_random(&G.random_gen));
2120 /* str holds "NAME=VAL" and is expected to be malloced.
2121 * We take ownership of it.
2123 #define SETFLAG_EXPORT (1 << 0)
2124 #define SETFLAG_UNEXPORT (1 << 1)
2125 #define SETFLAG_MAKE_RO (1 << 2)
2126 #define SETFLAG_LOCAL_SHIFT 3
2127 static int set_local_var(char *str, unsigned flags)
2129 struct variable **var_pp;
2130 struct variable *cur;
2131 char *free_me = NULL;
2134 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2136 eq_sign = strchr(str, '=');
2137 if (!eq_sign) { /* not expected to ever happen? */
2142 name_len = eq_sign - str + 1; /* including '=' */
2143 var_pp = &G.top_var;
2144 while ((cur = *var_pp) != NULL) {
2145 if (strncmp(cur->varstr, str, name_len) != 0) {
2146 var_pp = &cur->next;
2150 /* We found an existing var with this name */
2151 if (cur->flg_read_only) {
2152 bb_error_msg("%s: readonly variable", str);
2154 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2155 //but export per se succeeds (does put the var in env). We don't mimic that.
2158 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2159 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2164 #if ENABLE_HUSH_LOCAL
2165 if (cur->func_nest_level < local_lvl) {
2166 /* New variable is declared as local,
2167 * and existing one is global, or local
2168 * from enclosing function.
2169 * Remove and save old one: */
2170 *var_pp = cur->next;
2171 cur->next = *G.shadowed_vars_pp;
2172 *G.shadowed_vars_pp = cur;
2173 /* bash 3.2.33(1) and exported vars:
2175 * # f() { local z=a; env | grep ^z; }
2181 if (cur->flg_export)
2182 flags |= SETFLAG_EXPORT;
2186 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2191 if (cur->max_len != 0) {
2192 if (cur->max_len >= strlen(str)) {
2193 /* This one is from startup env, reuse space */
2194 strcpy(cur->varstr, str);
2199 goto set_str_and_exp;
2201 /* max_len == 0 signifies "malloced" var, which we can
2202 * (and have to) free. But we can't free(cur->varstr) here:
2203 * if cur->flg_export is 1, it is in the environment.
2204 * We should either unsetenv+free, or wait until putenv,
2205 * then putenv(new)+free(old).
2207 free_me = cur->varstr;
2208 goto set_str_and_exp;
2211 /* Not found - create new variable struct */
2212 cur = xzalloc(sizeof(*cur));
2213 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2214 cur->next = *var_pp;
2220 #if !BB_MMU || ENABLE_HUSH_READONLY
2221 if (flags & SETFLAG_MAKE_RO) {
2222 cur->flg_read_only = 1;
2225 if (flags & SETFLAG_EXPORT)
2226 cur->flg_export = 1;
2227 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2228 cmdedit_update_prompt();
2229 #if ENABLE_HUSH_GETOPTS
2230 /* defoptindvar is a "OPTIND=..." constant string */
2231 if (strncmp(cur->varstr, defoptindvar, 7) == 0)
2234 if (cur->flg_export) {
2235 if (flags & SETFLAG_UNEXPORT) {
2236 cur->flg_export = 0;
2237 /* unsetenv was already done */
2240 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2241 i = putenv(cur->varstr);
2242 /* only now we can free old exported malloced string */
2251 /* Used at startup and after each cd */
2252 static void set_pwd_var(unsigned flag)
2254 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2257 static int unset_local_var_len(const char *name, int name_len)
2259 struct variable *cur;
2260 struct variable **var_pp;
2263 return EXIT_SUCCESS;
2264 #if ENABLE_HUSH_GETOPTS
2265 if (name_len == 6 && strncmp(name, "OPTIND", 6) == 0)
2268 var_pp = &G.top_var;
2269 while ((cur = *var_pp) != NULL) {
2270 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2271 if (cur->flg_read_only) {
2272 bb_error_msg("%s: readonly variable", name);
2273 return EXIT_FAILURE;
2275 *var_pp = cur->next;
2276 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2277 bb_unsetenv(cur->varstr);
2278 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2279 cmdedit_update_prompt();
2283 return EXIT_SUCCESS;
2285 var_pp = &cur->next;
2287 return EXIT_SUCCESS;
2290 #if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS
2291 static int unset_local_var(const char *name)
2293 return unset_local_var_len(name, strlen(name));
2297 static void unset_vars(char **strings)
2305 const char *eq = strchrnul(*v, '=');
2306 unset_local_var_len(*v, (int)(eq - *v));
2312 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ || ENABLE_HUSH_GETOPTS
2313 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2315 char *var = xasprintf("%s=%s", name, val);
2316 set_local_var(var, /*flag:*/ 0);
2322 * Helpers for "var1=val1 var2=val2 cmd" feature
2324 static void add_vars(struct variable *var)
2326 struct variable *next;
2330 var->next = G.top_var;
2332 if (var->flg_export) {
2333 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2334 putenv(var->varstr);
2336 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2342 static struct variable *set_vars_and_save_old(char **strings)
2345 struct variable *old = NULL;
2351 struct variable *var_p;
2352 struct variable **var_pp;
2355 eq = strchr(*s, '=');
2357 var_pp = get_ptr_to_local_var(*s, eq - *s);
2360 if (var_p->flg_read_only) {
2362 bb_error_msg("%s: readonly variable", *s);
2364 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2365 * If VAR is readonly, leaving it in the list
2366 * after asssignment error (msg above)
2367 * causes doubled error message later, on unset.
2369 debug_printf_env("removing/freeing '%s' element\n", *s);
2372 do { *p = p[1]; p++; } while (*p);
2375 /* Remove variable from global linked list */
2376 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2377 *var_pp = var_p->next;
2378 /* Add it to returned list */
2382 set_local_var(*s, SETFLAG_EXPORT);
2394 static void reinit_unicode_for_hush(void)
2396 /* Unicode support should be activated even if LANG is set
2397 * _during_ shell execution, not only if it was set when
2398 * shell was started. Therefore, re-check LANG every time:
2400 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2401 || ENABLE_UNICODE_USING_LOCALE
2403 const char *s = get_local_var_value("LC_ALL");
2404 if (!s) s = get_local_var_value("LC_CTYPE");
2405 if (!s) s = get_local_var_value("LANG");
2411 * in_str support (strings, and "strings" read from files).
2414 #if ENABLE_HUSH_INTERACTIVE
2415 /* To test correct lineedit/interactive behavior, type from command line:
2421 * It exercises a lot of corner cases.
2423 static void cmdedit_update_prompt(void)
2425 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2426 G.PS1 = get_local_var_value("PS1");
2429 G.PS2 = get_local_var_value("PS2");
2436 static const char *setup_prompt_string(int promptmode)
2438 const char *prompt_str;
2439 debug_printf("setup_prompt_string %d ", promptmode);
2440 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2441 /* Set up the prompt */
2442 if (promptmode == 0) { /* PS1 */
2444 /* bash uses $PWD value, even if it is set by user.
2445 * It uses current dir only if PWD is unset.
2446 * We always use current dir. */
2447 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2452 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2453 debug_printf("prompt_str '%s'\n", prompt_str);
2456 static int get_user_input(struct in_str *i)
2459 const char *prompt_str;
2461 prompt_str = setup_prompt_string(i->promptmode);
2462 # if ENABLE_FEATURE_EDITING
2464 reinit_unicode_for_hush();
2465 if (G.flag_SIGINT) {
2466 /* There was ^C'ed, make it look prettier: */
2470 /* buglet: SIGINT will not make new prompt to appear _at once_,
2471 * only after <Enter>. (^C works immediately) */
2472 r = read_line_input(G.line_input_state, prompt_str,
2473 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
2475 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2478 check_and_run_traps();
2479 if (r != 0 && !G.flag_SIGINT)
2481 /* ^C or SIGINT: repeat */
2482 /* bash prints ^C even on real SIGINT (non-kbd generated) */
2483 write(STDOUT_FILENO, "^C", 2);
2484 G.last_exitcode = 128 + SIGINT;
2487 /* EOF/error detected */
2489 i->peek_buf[0] = r = EOF;
2492 i->p = G.user_input_buf;
2493 return (unsigned char)*i->p++;
2497 if (i->last_char == '\0' || i->last_char == '\n') {
2498 /* Why check_and_run_traps here? Try this interactively:
2499 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2500 * $ <[enter], repeatedly...>
2501 * Without check_and_run_traps, handler never runs.
2503 check_and_run_traps();
2504 fputs(prompt_str, stdout);
2507 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2509 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2510 * no ^C masking happens during fgetc, no special code for ^C:
2511 * it generates SIGINT as usual.
2513 check_and_run_traps();
2515 G.last_exitcode = 128 + SIGINT;
2522 /* This is the magic location that prints prompts
2523 * and gets data back from the user */
2524 static int fgetc_interactive(struct in_str *i)
2527 /* If it's interactive stdin, get new line. */
2528 if (G_interactive_fd && i->file == stdin) {
2529 /* Returns first char (or EOF), the rest is in i->p[] */
2530 ch = get_user_input(i);
2531 i->promptmode = 1; /* PS2 */
2533 /* Not stdin: script file, sourced file, etc */
2534 do ch = fgetc(i->file); while (ch == '\0');
2539 static inline int fgetc_interactive(struct in_str *i)
2542 do ch = fgetc(i->file); while (ch == '\0');
2545 #endif /* INTERACTIVE */
2547 static int i_getch(struct in_str *i)
2552 /* string-based in_str */
2553 ch = (unsigned char)*i->p;
2562 /* FILE-based in_str */
2564 #if ENABLE_FEATURE_EDITING
2565 /* This can be stdin, check line editing char[] buffer */
2566 if (i->p && *i->p != '\0') {
2567 ch = (unsigned char)*i->p++;
2571 /* peek_buf[] is an int array, not char. Can contain EOF. */
2572 ch = i->peek_buf[0];
2574 int ch2 = i->peek_buf[1];
2575 i->peek_buf[0] = ch2;
2576 if (ch2 == 0) /* very likely, avoid redundant write */
2582 ch = fgetc_interactive(i);
2584 debug_printf("file_get: got '%c' %d\n", ch, ch);
2589 static int i_peek(struct in_str *i)
2594 /* string-based in_str */
2595 /* Doesn't report EOF on NUL. None of the callers care. */
2596 return (unsigned char)*i->p;
2599 /* FILE-based in_str */
2601 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2602 /* This can be stdin, check line editing char[] buffer */
2603 if (i->p && *i->p != '\0')
2604 return (unsigned char)*i->p;
2606 /* peek_buf[] is an int array, not char. Can contain EOF. */
2607 ch = i->peek_buf[0];
2611 /* Need to get a new char */
2612 ch = fgetc_interactive(i);
2613 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2615 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2616 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2622 i->peek_buf[0] = ch;
2623 /*i->peek_buf[1] = 0; - already is */
2627 /* Only ever called if i_peek() was called, and did not return EOF.
2628 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2629 * not end-of-line. Therefore we never need to read a new editing line here.
2631 static int i_peek2(struct in_str *i)
2635 /* There are two cases when i->p[] buffer exists.
2636 * (1) it's a string in_str.
2637 * (2) It's a file, and we have a saved line editing buffer.
2638 * In both cases, we know that i->p[0] exists and not NUL, and
2639 * the peek2 result is in i->p[1].
2642 return (unsigned char)i->p[1];
2644 /* Now we know it is a file-based in_str. */
2646 /* peek_buf[] is an int array, not char. Can contain EOF. */
2647 /* Is there 2nd char? */
2648 ch = i->peek_buf[1];
2650 /* We did not read it yet, get it now */
2651 do ch = fgetc(i->file); while (ch == '\0');
2652 i->peek_buf[1] = ch;
2655 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2659 static void setup_file_in_str(struct in_str *i, FILE *f)
2661 memset(i, 0, sizeof(*i));
2662 /* i->promptmode = 0; - PS1 (memset did it) */
2667 static void setup_string_in_str(struct in_str *i, const char *s)
2669 memset(i, 0, sizeof(*i));
2670 /* i->promptmode = 0; - PS1 (memset did it) */
2671 /*i->file = NULL */;
2679 #define B_CHUNK (32 * sizeof(char*))
2681 static void o_reset_to_empty_unquoted(o_string *o)
2684 o->has_quoted_part = 0;
2689 static void o_free(o_string *o)
2692 memset(o, 0, sizeof(*o));
2695 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2700 static void o_grow_by(o_string *o, int len)
2702 if (o->length + len > o->maxlen) {
2703 o->maxlen += (2 * len) | (B_CHUNK-1);
2704 o->data = xrealloc(o->data, 1 + o->maxlen);
2708 static void o_addchr(o_string *o, int ch)
2710 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2711 if (o->length < o->maxlen) {
2712 /* likely. avoid o_grow_by() call */
2714 o->data[o->length] = ch;
2716 o->data[o->length] = '\0';
2724 /* Valid only if we know o_string is not empty */
2725 static void o_delchr(o_string *o)
2728 o->data[o->length] = '\0';
2732 static void o_addblock(o_string *o, const char *str, int len)
2735 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2739 static void o_addstr(o_string *o, const char *str)
2741 o_addblock(o, str, strlen(str));
2745 static void nommu_addchr(o_string *o, int ch)
2751 # define nommu_addchr(o, str) ((void)0)
2754 static void o_addstr_with_NUL(o_string *o, const char *str)
2756 o_addblock(o, str, strlen(str) + 1);
2760 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2761 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2762 * Apparently, on unquoted $v bash still does globbing
2763 * ("v='*.txt'; echo $v" prints all .txt files),
2764 * but NOT brace expansion! Thus, there should be TWO independent
2765 * quoting mechanisms on $v expansion side: one protects
2766 * $v from brace expansion, and other additionally protects "$v" against globbing.
2767 * We have only second one.
2770 #if ENABLE_HUSH_BRACE_EXPANSION
2771 # define MAYBE_BRACES "{}"
2773 # define MAYBE_BRACES ""
2776 /* My analysis of quoting semantics tells me that state information
2777 * is associated with a destination, not a source.
2779 static void o_addqchr(o_string *o, int ch)
2782 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2787 o->data[o->length] = '\\';
2790 o->data[o->length] = ch;
2792 o->data[o->length] = '\0';
2795 static void o_addQchr(o_string *o, int ch)
2798 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2799 && strchr("*?[\\" MAYBE_BRACES, ch)
2802 o->data[o->length] = '\\';
2806 o->data[o->length] = ch;
2808 o->data[o->length] = '\0';
2811 static void o_addqblock(o_string *o, const char *str, int len)
2816 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2817 if (ordinary_cnt > len) /* paranoia */
2819 o_addblock(o, str, ordinary_cnt);
2820 if (ordinary_cnt == len)
2821 return; /* NUL is already added by o_addblock */
2822 str += ordinary_cnt;
2823 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2827 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2829 o->data[o->length] = '\\';
2833 o->data[o->length] = ch;
2836 o->data[o->length] = '\0';
2839 static void o_addQblock(o_string *o, const char *str, int len)
2841 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2842 o_addblock(o, str, len);
2845 o_addqblock(o, str, len);
2848 static void o_addQstr(o_string *o, const char *str)
2850 o_addQblock(o, str, strlen(str));
2853 /* A special kind of o_string for $VAR and `cmd` expansion.
2854 * It contains char* list[] at the beginning, which is grown in 16 element
2855 * increments. Actual string data starts at the next multiple of 16 * (char*).
2856 * list[i] contains an INDEX (int!) into this string data.
2857 * It means that if list[] needs to grow, data needs to be moved higher up
2858 * but list[i]'s need not be modified.
2859 * NB: remembering how many list[i]'s you have there is crucial.
2860 * o_finalize_list() operation post-processes this structure - calculates
2861 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2863 #if DEBUG_EXPAND || DEBUG_GLOB
2864 static void debug_print_list(const char *prefix, o_string *o, int n)
2866 char **list = (char**)o->data;
2867 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2871 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2872 prefix, list, n, string_start, o->length, o->maxlen,
2873 !!(o->o_expflags & EXP_FLAG_GLOB),
2875 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2878 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2879 o->data + (int)(uintptr_t)list[i] + string_start,
2880 o->data + (int)(uintptr_t)list[i] + string_start);
2884 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2886 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2890 # define debug_print_list(prefix, o, n) ((void)0)
2893 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2894 * in list[n] so that it points past last stored byte so far.
2895 * It returns n+1. */
2896 static int o_save_ptr_helper(o_string *o, int n)
2898 char **list = (char**)o->data;
2902 if (!o->has_empty_slot) {
2903 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2904 string_len = o->length - string_start;
2905 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2906 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2907 /* list[n] points to string_start, make space for 16 more pointers */
2908 o->maxlen += 0x10 * sizeof(list[0]);
2909 o->data = xrealloc(o->data, o->maxlen + 1);
2910 list = (char**)o->data;
2911 memmove(list + n + 0x10, list + n, string_len);
2912 o->length += 0x10 * sizeof(list[0]);
2914 debug_printf_list("list[%d]=%d string_start=%d\n",
2915 n, string_len, string_start);
2918 /* We have empty slot at list[n], reuse without growth */
2919 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2920 string_len = o->length - string_start;
2921 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2922 n, string_len, string_start);
2923 o->has_empty_slot = 0;
2925 o->has_quoted_part = 0;
2926 list[n] = (char*)(uintptr_t)string_len;
2930 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2931 static int o_get_last_ptr(o_string *o, int n)
2933 char **list = (char**)o->data;
2934 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2936 return ((int)(uintptr_t)list[n-1]) + string_start;
2939 #if ENABLE_HUSH_BRACE_EXPANSION
2940 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2941 * first, it processes even {a} (no commas), second,
2942 * I didn't manage to make it return strings when they don't match
2943 * existing files. Need to re-implement it.
2947 static int glob_needed(const char *s)
2956 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2962 /* Return pointer to next closing brace or to comma */
2963 static const char *next_brace_sub(const char *cp)
2967 while (*cp != '\0') {
2974 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2980 return *cp != '\0' ? cp : NULL;
2982 /* Recursive brace globber. Note: may garble pattern[]. */
2983 static int glob_brace(char *pattern, o_string *o, int n)
2985 char *new_pattern_buf;
2992 debug_printf_glob("glob_brace('%s')\n", pattern);
2998 if (*begin == '{') {
2999 /* Find the first sub-pattern and at the same time
3000 * find the rest after the closing brace */
3001 next = next_brace_sub(begin);
3003 /* An illegal expression */
3007 /* "{abc}" with no commas - illegal
3008 * brace expr, disregard and skip it */
3014 if (*begin == '\\' && begin[1] != '\0')
3018 debug_printf_glob("begin:%s\n", begin);
3019 debug_printf_glob("next:%s\n", next);
3021 /* Now find the end of the whole brace expression */
3023 while (*rest != '}') {
3024 rest = next_brace_sub(rest);
3026 /* An illegal expression */
3029 debug_printf_glob("rest:%s\n", rest);
3031 rest_len = strlen(++rest) + 1;
3033 /* We are sure the brace expression is well-formed */
3035 /* Allocate working buffer large enough for our work */
3036 new_pattern_buf = xmalloc(strlen(pattern));
3038 /* We have a brace expression. BEGIN points to the opening {,
3039 * NEXT points past the terminator of the first element, and REST
3040 * points past the final }. We will accumulate result names from
3041 * recursive runs for each brace alternative in the buffer using
3046 /* Construct the new glob expression */
3049 mempcpy(new_pattern_buf,
3050 /* We know the prefix for all sub-patterns */
3051 pattern, begin - pattern),
3055 /* Note: glob_brace() may garble new_pattern_buf[].
3056 * That's why we re-copy prefix every time (1st memcpy above).
3058 n = glob_brace(new_pattern_buf, o, n);
3060 /* We saw the last entry */
3064 next = next_brace_sub(next);
3066 free(new_pattern_buf);
3074 memset(&globdata, 0, sizeof(globdata));
3075 gr = glob(pattern, 0, NULL, &globdata);
3076 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3078 if (gr == GLOB_NOMATCH) {
3079 globfree(&globdata);
3080 /* NB: garbles parameter */
3081 unbackslash(pattern);
3082 o_addstr_with_NUL(o, pattern);
3083 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3084 return o_save_ptr_helper(o, n);
3086 if (gr == GLOB_NOSPACE)
3087 bb_error_msg_and_die(bb_msg_memory_exhausted);
3088 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3089 * but we didn't specify it. Paranoia again. */
3090 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3092 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3093 char **argv = globdata.gl_pathv;
3095 o_addstr_with_NUL(o, *argv);
3096 n = o_save_ptr_helper(o, n);
3102 globfree(&globdata);
3106 /* Performs globbing on last list[],
3107 * saving each result as a new list[].
3109 static int perform_glob(o_string *o, int n)
3111 char *pattern, *copy;
3113 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3115 return o_save_ptr_helper(o, n);
3116 pattern = o->data + o_get_last_ptr(o, n);
3117 debug_printf_glob("glob pattern '%s'\n", pattern);
3118 if (!glob_needed(pattern)) {
3119 /* unbackslash last string in o in place, fix length */
3120 o->length = unbackslash(pattern) - o->data;
3121 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3122 return o_save_ptr_helper(o, n);
3125 copy = xstrdup(pattern);
3126 /* "forget" pattern in o */
3127 o->length = pattern - o->data;
3128 n = glob_brace(copy, o, n);
3131 debug_print_list("perform_glob returning", o, n);
3135 #else /* !HUSH_BRACE_EXPANSION */
3138 static int glob_needed(const char *s)
3147 if (*s == '*' || *s == '[' || *s == '?')
3153 /* Performs globbing on last list[],
3154 * saving each result as a new list[].
3156 static int perform_glob(o_string *o, int n)
3162 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3164 return o_save_ptr_helper(o, n);
3165 pattern = o->data + o_get_last_ptr(o, n);
3166 debug_printf_glob("glob pattern '%s'\n", pattern);
3167 if (!glob_needed(pattern)) {
3169 /* unbackslash last string in o in place, fix length */
3170 o->length = unbackslash(pattern) - o->data;
3171 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3172 return o_save_ptr_helper(o, n);
3175 memset(&globdata, 0, sizeof(globdata));
3176 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3177 * If we glob "*.\*" and don't find anything, we need
3178 * to fall back to using literal "*.*", but GLOB_NOCHECK
3179 * will return "*.\*"!
3181 gr = glob(pattern, 0, NULL, &globdata);
3182 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3184 if (gr == GLOB_NOMATCH) {
3185 globfree(&globdata);
3188 if (gr == GLOB_NOSPACE)
3189 bb_error_msg_and_die(bb_msg_memory_exhausted);
3190 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3191 * but we didn't specify it. Paranoia again. */
3192 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3194 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3195 char **argv = globdata.gl_pathv;
3196 /* "forget" pattern in o */
3197 o->length = pattern - o->data;
3199 o_addstr_with_NUL(o, *argv);
3200 n = o_save_ptr_helper(o, n);
3206 globfree(&globdata);
3208 debug_print_list("perform_glob returning", o, n);
3212 #endif /* !HUSH_BRACE_EXPANSION */
3214 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3215 * Otherwise, just finish current list[] and start new */
3216 static int o_save_ptr(o_string *o, int n)
3218 if (o->o_expflags & EXP_FLAG_GLOB) {
3219 /* If o->has_empty_slot, list[n] was already globbed
3220 * (if it was requested back then when it was filled)
3221 * so don't do that again! */
3222 if (!o->has_empty_slot)
3223 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3225 return o_save_ptr_helper(o, n);
3228 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3229 static char **o_finalize_list(o_string *o, int n)
3234 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3236 debug_print_list("finalized", o, n);
3237 debug_printf_expand("finalized n:%d\n", n);
3238 list = (char**)o->data;
3239 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3243 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3248 static void free_pipe_list(struct pipe *pi);
3250 /* Returns pi->next - next pipe in the list */
3251 static struct pipe *free_pipe(struct pipe *pi)
3256 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3257 for (i = 0; i < pi->num_cmds; i++) {
3258 struct command *command;
3259 struct redir_struct *r, *rnext;
3261 command = &pi->cmds[i];
3262 debug_printf_clean(" command %d:\n", i);
3263 if (command->argv) {
3267 for (a = 0, p = command->argv; *p; a++, p++) {
3268 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3271 free_strings(command->argv);
3272 //command->argv = NULL;
3274 /* not "else if": on syntax error, we may have both! */
3275 if (command->group) {
3276 debug_printf_clean(" begin group (cmd_type:%d)\n",
3278 free_pipe_list(command->group);
3279 debug_printf_clean(" end group\n");
3280 //command->group = NULL;
3282 /* else is crucial here.
3283 * If group != NULL, child_func is meaningless */
3284 #if ENABLE_HUSH_FUNCTIONS
3285 else if (command->child_func) {
3286 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3287 command->child_func->parent_cmd = NULL;
3291 free(command->group_as_string);
3292 //command->group_as_string = NULL;
3294 for (r = command->redirects; r; r = rnext) {
3295 debug_printf_clean(" redirect %d%s",
3296 r->rd_fd, redir_table[r->rd_type].descrip);
3297 /* guard against the case >$FOO, where foo is unset or blank */
3298 if (r->rd_filename) {
3299 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3300 free(r->rd_filename);
3301 //r->rd_filename = NULL;
3303 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3307 //command->redirects = NULL;
3309 free(pi->cmds); /* children are an array, they get freed all at once */
3313 //pi->cmdtext = NULL;
3321 static void free_pipe_list(struct pipe *pi)
3325 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3327 debug_printf_clean("pipe followup code %d\n", pi->followup);
3333 /*** Parsing routines ***/
3335 #ifndef debug_print_tree
3336 static void debug_print_tree(struct pipe *pi, int lvl)
3338 static const char *const PIPE[] = {
3344 static const char *RES[] = {
3345 [RES_NONE ] = "NONE" ,
3348 [RES_THEN ] = "THEN" ,
3349 [RES_ELIF ] = "ELIF" ,
3350 [RES_ELSE ] = "ELSE" ,
3353 # if ENABLE_HUSH_LOOPS
3354 [RES_FOR ] = "FOR" ,
3355 [RES_WHILE] = "WHILE",
3356 [RES_UNTIL] = "UNTIL",
3358 [RES_DONE ] = "DONE" ,
3360 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3363 # if ENABLE_HUSH_CASE
3364 [RES_CASE ] = "CASE" ,
3365 [RES_CASE_IN ] = "CASE_IN" ,
3366 [RES_MATCH] = "MATCH",
3367 [RES_CASE_BODY] = "CASE_BODY",
3368 [RES_ESAC ] = "ESAC" ,
3370 [RES_XXXX ] = "XXXX" ,
3371 [RES_SNTX ] = "SNTX" ,
3373 static const char *const CMDTYPE[] = {
3377 # if ENABLE_HUSH_FUNCTIONS
3386 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3387 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3389 while (prn < pi->num_cmds) {
3390 struct command *command = &pi->cmds[prn];
3391 char **argv = command->argv;
3393 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3395 command->assignment_cnt);
3396 if (command->group) {
3397 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3398 CMDTYPE[command->cmd_type],
3401 , " group_as_string:", command->group_as_string
3406 debug_print_tree(command->group, lvl+1);
3410 if (argv) while (*argv) {
3411 fdprintf(2, " '%s'", *argv);
3421 #endif /* debug_print_tree */
3423 static struct pipe *new_pipe(void)
3426 pi = xzalloc(sizeof(struct pipe));
3427 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3431 /* Command (member of a pipe) is complete, or we start a new pipe
3432 * if ctx->command is NULL.
3433 * No errors possible here.
3435 static int done_command(struct parse_context *ctx)
3437 /* The command is really already in the pipe structure, so
3438 * advance the pipe counter and make a new, null command. */
3439 struct pipe *pi = ctx->pipe;
3440 struct command *command = ctx->command;
3442 #if 0 /* Instead we emit error message at run time */
3443 if (ctx->pending_redirect) {
3444 /* For example, "cmd >" (no filename to redirect to) */
3445 syntax_error("invalid redirect");
3446 ctx->pending_redirect = NULL;
3451 if (IS_NULL_CMD(command)) {
3452 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3456 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3457 //debug_print_tree(ctx->list_head, 20);
3459 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3462 /* Only real trickiness here is that the uncommitted
3463 * command structure is not counted in pi->num_cmds. */
3464 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3465 ctx->command = command = &pi->cmds[pi->num_cmds];
3467 memset(command, 0, sizeof(*command));
3468 return pi->num_cmds; /* used only for 0/nonzero check */
3471 static void done_pipe(struct parse_context *ctx, pipe_style type)
3475 debug_printf_parse("done_pipe entered, followup %d\n", type);
3476 /* Close previous command */
3477 not_null = done_command(ctx);
3479 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3480 ctx->ctx_inverted = 0;
3481 ctx->pipe->res_word = ctx->ctx_res_w;
3483 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3484 /* Necessary since && and || have precedence over &:
3485 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3486 * in a backgrounded subshell.
3489 struct command *command;
3491 /* Is this actually this construct, all pipes end with && or ||? */
3492 pi = ctx->list_head;
3493 while (pi != ctx->pipe) {
3494 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3499 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3500 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3501 pi = xzalloc(sizeof(*pi));
3502 pi->followup = PIPE_BG;
3504 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3505 command = &pi->cmds[0];
3506 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3507 command->cmd_type = CMD_NORMAL;
3508 command->group = ctx->list_head;
3510 command->group_as_string = xstrndup(
3511 ctx->as_string.data,
3512 ctx->as_string.length - 1 /* do not copy last char, "&" */
3515 /* Replace all pipes in ctx with one newly created */
3516 ctx->list_head = ctx->pipe = pi;
3519 ctx->pipe->followup = type;
3522 /* Without this check, even just <enter> on command line generates
3523 * tree of three NOPs (!). Which is harmless but annoying.
3524 * IOW: it is safe to do it unconditionally. */
3527 || ctx->ctx_res_w == RES_FI
3529 #if ENABLE_HUSH_LOOPS
3530 || ctx->ctx_res_w == RES_DONE
3531 || ctx->ctx_res_w == RES_FOR
3532 || ctx->ctx_res_w == RES_IN
3534 #if ENABLE_HUSH_CASE
3535 || ctx->ctx_res_w == RES_ESAC
3539 debug_printf_parse("done_pipe: adding new pipe: "
3540 "not_null:%d ctx->ctx_res_w:%d\n",
3541 not_null, ctx->ctx_res_w);
3543 ctx->pipe->next = new_p;
3545 /* RES_THEN, RES_DO etc are "sticky" -
3546 * they remain set for pipes inside if/while.
3547 * This is used to control execution.
3548 * RES_FOR and RES_IN are NOT sticky (needed to support
3549 * cases where variable or value happens to match a keyword):
3551 #if ENABLE_HUSH_LOOPS
3552 if (ctx->ctx_res_w == RES_FOR
3553 || ctx->ctx_res_w == RES_IN)
3554 ctx->ctx_res_w = RES_NONE;
3556 #if ENABLE_HUSH_CASE
3557 if (ctx->ctx_res_w == RES_MATCH)
3558 ctx->ctx_res_w = RES_CASE_BODY;
3559 if (ctx->ctx_res_w == RES_CASE)
3560 ctx->ctx_res_w = RES_CASE_IN;
3562 ctx->command = NULL; /* trick done_command below */
3563 /* Create the memory for command, roughly:
3564 * ctx->pipe->cmds = new struct command;
3565 * ctx->command = &ctx->pipe->cmds[0];
3568 //debug_print_tree(ctx->list_head, 10);
3570 debug_printf_parse("done_pipe return\n");
3573 static void initialize_context(struct parse_context *ctx)
3575 memset(ctx, 0, sizeof(*ctx));
3576 ctx->pipe = ctx->list_head = new_pipe();
3577 /* Create the memory for command, roughly:
3578 * ctx->pipe->cmds = new struct command;
3579 * ctx->command = &ctx->pipe->cmds[0];
3584 /* If a reserved word is found and processed, parse context is modified
3585 * and 1 is returned.
3588 struct reserved_combo {
3591 unsigned char assignment_flag;
3595 FLAG_END = (1 << RES_NONE ),
3597 FLAG_IF = (1 << RES_IF ),
3598 FLAG_THEN = (1 << RES_THEN ),
3599 FLAG_ELIF = (1 << RES_ELIF ),
3600 FLAG_ELSE = (1 << RES_ELSE ),
3601 FLAG_FI = (1 << RES_FI ),
3603 # if ENABLE_HUSH_LOOPS
3604 FLAG_FOR = (1 << RES_FOR ),
3605 FLAG_WHILE = (1 << RES_WHILE),
3606 FLAG_UNTIL = (1 << RES_UNTIL),
3607 FLAG_DO = (1 << RES_DO ),
3608 FLAG_DONE = (1 << RES_DONE ),
3609 FLAG_IN = (1 << RES_IN ),
3611 # if ENABLE_HUSH_CASE
3612 FLAG_MATCH = (1 << RES_MATCH),
3613 FLAG_ESAC = (1 << RES_ESAC ),
3615 FLAG_START = (1 << RES_XXXX ),
3618 static const struct reserved_combo* match_reserved_word(o_string *word)
3620 /* Mostly a list of accepted follow-up reserved words.
3621 * FLAG_END means we are done with the sequence, and are ready
3622 * to turn the compound list into a command.
3623 * FLAG_START means the word must start a new compound list.
3625 static const struct reserved_combo reserved_list[] = {
3627 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3628 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3629 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3630 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3631 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3632 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3634 # if ENABLE_HUSH_LOOPS
3635 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3636 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3637 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3638 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3639 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3640 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3642 # if ENABLE_HUSH_CASE
3643 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3644 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3647 const struct reserved_combo *r;
3649 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3650 if (strcmp(word->data, r->literal) == 0)
3655 /* Return 0: not a keyword, 1: keyword
3657 static int reserved_word(o_string *word, struct parse_context *ctx)
3659 # if ENABLE_HUSH_CASE
3660 static const struct reserved_combo reserved_match = {
3661 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3664 const struct reserved_combo *r;
3666 if (word->has_quoted_part)
3668 r = match_reserved_word(word);
3672 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3673 # if ENABLE_HUSH_CASE
3674 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3675 /* "case word IN ..." - IN part starts first MATCH part */
3676 r = &reserved_match;
3679 if (r->flag == 0) { /* '!' */
3680 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3681 syntax_error("! ! command");
3682 ctx->ctx_res_w = RES_SNTX;
3684 ctx->ctx_inverted = 1;
3687 if (r->flag & FLAG_START) {
3688 struct parse_context *old;
3690 old = xmemdup(ctx, sizeof(*ctx));
3691 debug_printf_parse("push stack %p\n", old);
3692 initialize_context(ctx);
3694 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3695 syntax_error_at(word->data);
3696 ctx->ctx_res_w = RES_SNTX;
3699 /* "{...} fi" is ok. "{...} if" is not
3701 * if { echo foo; } then { echo bar; } fi */
3702 if (ctx->command->group)
3703 done_pipe(ctx, PIPE_SEQ);
3706 ctx->ctx_res_w = r->res;
3707 ctx->old_flag = r->flag;
3708 word->o_assignment = r->assignment_flag;
3709 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3711 if (ctx->old_flag & FLAG_END) {
3712 struct parse_context *old;
3714 done_pipe(ctx, PIPE_SEQ);
3715 debug_printf_parse("pop stack %p\n", ctx->stack);
3717 old->command->group = ctx->list_head;
3718 old->command->cmd_type = CMD_NORMAL;
3720 /* At this point, the compound command's string is in
3721 * ctx->as_string... except for the leading keyword!
3722 * Consider this example: "echo a | if true; then echo a; fi"
3723 * ctx->as_string will contain "true; then echo a; fi",
3724 * with "if " remaining in old->as_string!
3728 int len = old->as_string.length;
3729 /* Concatenate halves */
3730 o_addstr(&old->as_string, ctx->as_string.data);
3731 o_free_unsafe(&ctx->as_string);
3732 /* Find where leading keyword starts in first half */
3733 str = old->as_string.data + len;
3734 if (str > old->as_string.data)
3735 str--; /* skip whitespace after keyword */
3736 while (str > old->as_string.data && isalpha(str[-1]))
3738 /* Ugh, we're done with this horrid hack */
3739 old->command->group_as_string = xstrdup(str);
3740 debug_printf_parse("pop, remembering as:'%s'\n",
3741 old->command->group_as_string);
3744 *ctx = *old; /* physical copy */
3749 #endif /* HAS_KEYWORDS */
3751 /* Word is complete, look at it and update parsing context.
3752 * Normal return is 0. Syntax errors return 1.
3753 * Note: on return, word is reset, but not o_free'd!
3755 static int done_word(o_string *word, struct parse_context *ctx)
3757 struct command *command = ctx->command;
3759 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3760 if (word->length == 0 && !word->has_quoted_part) {
3761 debug_printf_parse("done_word return 0: true null, ignored\n");
3765 if (ctx->pending_redirect) {
3766 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3767 * only if run as "bash", not "sh" */
3768 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3770 * ...the word that follows the redirection operator
3771 * shall be subjected to tilde expansion, parameter expansion,
3772 * command substitution, arithmetic expansion, and quote
3773 * removal. Pathname expansion shall not be performed
3774 * on the word by a non-interactive shell; an interactive
3775 * shell may perform it, but shall do so only when
3776 * the expansion would result in one word."
3778 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3779 /* Cater for >\file case:
3780 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3781 * Same with heredocs:
3782 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3784 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3785 unbackslash(ctx->pending_redirect->rd_filename);
3786 /* Is it <<"HEREDOC"? */
3787 if (word->has_quoted_part) {
3788 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3791 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3792 ctx->pending_redirect = NULL;
3795 # if ENABLE_HUSH_CASE
3796 if (ctx->ctx_dsemicolon
3797 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3799 /* already done when ctx_dsemicolon was set to 1: */
3800 /* ctx->ctx_res_w = RES_MATCH; */
3801 ctx->ctx_dsemicolon = 0;
3804 if (!command->argv /* if it's the first word... */
3805 # if ENABLE_HUSH_LOOPS
3806 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3807 && ctx->ctx_res_w != RES_IN
3809 # if ENABLE_HUSH_CASE
3810 && ctx->ctx_res_w != RES_CASE
3813 int reserved = reserved_word(word, ctx);
3814 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3816 o_reset_to_empty_unquoted(word);
3817 debug_printf_parse("done_word return %d\n",
3818 (ctx->ctx_res_w == RES_SNTX));
3819 return (ctx->ctx_res_w == RES_SNTX);
3822 if (strcmp(word->data, "[[") == 0) {
3823 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3829 if (command->group) {
3830 /* "{ echo foo; } echo bar" - bad */
3831 syntax_error_at(word->data);
3832 debug_printf_parse("done_word return 1: syntax error, "
3833 "groups and arglists don't mix\n");
3837 /* If this word wasn't an assignment, next ones definitely
3838 * can't be assignments. Even if they look like ones. */
3839 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3840 && word->o_assignment != WORD_IS_KEYWORD
3842 word->o_assignment = NOT_ASSIGNMENT;
3844 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3845 command->assignment_cnt++;
3846 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3848 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3849 word->o_assignment = MAYBE_ASSIGNMENT;
3851 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3852 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3853 debug_print_strings("word appended to argv", command->argv);
3856 #if ENABLE_HUSH_LOOPS
3857 if (ctx->ctx_res_w == RES_FOR) {
3858 if (word->has_quoted_part
3859 || !is_well_formed_var_name(command->argv[0], '\0')
3861 /* bash says just "not a valid identifier" */
3862 syntax_error("not a valid identifier in for");
3865 /* Force FOR to have just one word (variable name) */
3866 /* NB: basically, this makes hush see "for v in ..."
3867 * syntax as if it is "for v; in ...". FOR and IN become
3868 * two pipe structs in parse tree. */
3869 done_pipe(ctx, PIPE_SEQ);
3872 #if ENABLE_HUSH_CASE
3873 /* Force CASE to have just one word */
3874 if (ctx->ctx_res_w == RES_CASE) {
3875 done_pipe(ctx, PIPE_SEQ);
3879 o_reset_to_empty_unquoted(word);
3881 debug_printf_parse("done_word return 0\n");
3886 /* Peek ahead in the input to find out if we have a "&n" construct,
3887 * as in "2>&1", that represents duplicating a file descriptor.
3889 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3890 * REDIRFD_SYNTAX_ERR if syntax error,
3891 * REDIRFD_TO_FILE if no & was seen,
3892 * or the number found.
3895 #define parse_redir_right_fd(as_string, input) \
3896 parse_redir_right_fd(input)
3898 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3904 return REDIRFD_TO_FILE;
3906 ch = i_getch(input); /* get the & */
3907 nommu_addchr(as_string, ch);
3910 ch = i_getch(input);
3911 nommu_addchr(as_string, ch);
3912 return REDIRFD_CLOSE;
3916 while (ch != EOF && isdigit(ch)) {
3917 d = d*10 + (ch-'0');
3919 ch = i_getch(input);
3920 nommu_addchr(as_string, ch);
3925 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3927 bb_error_msg("ambiguous redirect");
3928 return REDIRFD_SYNTAX_ERR;
3931 /* Return code is 0 normal, 1 if a syntax error is detected
3933 static int parse_redirect(struct parse_context *ctx,
3936 struct in_str *input)
3938 struct command *command = ctx->command;
3939 struct redir_struct *redir;
3940 struct redir_struct **redirp;
3943 dup_num = REDIRFD_TO_FILE;
3944 if (style != REDIRECT_HEREDOC) {
3945 /* Check for a '>&1' type redirect */
3946 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3947 if (dup_num == REDIRFD_SYNTAX_ERR)
3950 int ch = i_peek(input);
3951 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3952 if (dup_num) { /* <<-... */
3953 ch = i_getch(input);
3954 nommu_addchr(&ctx->as_string, ch);
3959 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3960 int ch = i_peek(input);
3962 /* >|FILE redirect ("clobbering" >).
3963 * Since we do not support "set -o noclobber" yet,
3964 * >| and > are the same for now. Just eat |.
3966 ch = i_getch(input);
3967 nommu_addchr(&ctx->as_string, ch);
3971 /* Create a new redir_struct and append it to the linked list */
3972 redirp = &command->redirects;
3973 while ((redir = *redirp) != NULL) {
3974 redirp = &(redir->next);
3976 *redirp = redir = xzalloc(sizeof(*redir));
3977 /* redir->next = NULL; */
3978 /* redir->rd_filename = NULL; */
3979 redir->rd_type = style;
3980 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3982 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3983 redir_table[style].descrip);
3985 redir->rd_dup = dup_num;
3986 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3987 /* Erik had a check here that the file descriptor in question
3988 * is legit; I postpone that to "run time"
3989 * A "-" representation of "close me" shows up as a -3 here */
3990 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3991 redir->rd_fd, redir->rd_dup);
3993 #if 0 /* Instead we emit error message at run time */
3994 if (ctx->pending_redirect) {
3995 /* For example, "cmd > <file" */
3996 syntax_error("invalid redirect");
3999 /* Set ctx->pending_redirect, so we know what to do at the
4000 * end of the next parsed word. */
4001 ctx->pending_redirect = redir;
4006 /* If a redirect is immediately preceded by a number, that number is
4007 * supposed to tell which file descriptor to redirect. This routine
4008 * looks for such preceding numbers. In an ideal world this routine
4009 * needs to handle all the following classes of redirects...
4010 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4011 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4012 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4013 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4015 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4017 * ... If n is quoted, the number shall not be recognized as part of
4018 * the redirection expression. For example:
4020 * writes the character 2 into file a"
4021 * We are getting it right by setting ->has_quoted_part on any \<char>
4023 * A -1 return means no valid number was found,
4024 * the caller should use the appropriate default for this redirection.
4026 static int redirect_opt_num(o_string *o)
4030 if (o->data == NULL)
4032 num = bb_strtou(o->data, NULL, 10);
4033 if (errno || num < 0)
4035 o_reset_to_empty_unquoted(o);
4040 #define fetch_till_str(as_string, input, word, skip_tabs) \
4041 fetch_till_str(input, word, skip_tabs)
4043 static char *fetch_till_str(o_string *as_string,
4044 struct in_str *input,
4048 o_string heredoc = NULL_O_STRING;
4050 int prev = 0; /* not \ */
4056 ch = i_getch(input);
4058 nommu_addchr(as_string, ch);
4059 if (ch == '\n' || ch == EOF) {
4061 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4062 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4063 heredoc.data[past_EOL] = '\0';
4064 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4065 return heredoc.data;
4068 /* This is a new line.
4069 * Remember position and backslash-escaping status.
4071 o_addchr(&heredoc, ch);
4074 past_EOL = heredoc.length;
4075 /* Get 1st char of next line, possibly skipping leading tabs */
4077 ch = i_getch(input);
4079 nommu_addchr(as_string, ch);
4080 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4081 /* If this immediately ended the line,
4082 * go back to end-of-line checks.
4085 goto check_heredoc_end;
4090 o_free_unsafe(&heredoc);
4093 o_addchr(&heredoc, ch);
4094 nommu_addchr(as_string, ch);
4095 if (prev == '\\' && ch == '\\')
4096 /* Correctly handle foo\\<eol> (not a line cont.) */
4097 prev = 0; /* not \ */
4103 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4104 * and load them all. There should be exactly heredoc_cnt of them.
4106 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4108 struct pipe *pi = ctx->list_head;
4110 while (pi && heredoc_cnt) {
4112 struct command *cmd = pi->cmds;
4114 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4116 cmd->argv ? cmd->argv[0] : "NONE");
4117 for (i = 0; i < pi->num_cmds; i++) {
4118 struct redir_struct *redir = cmd->redirects;
4120 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4121 i, cmd->argv ? cmd->argv[0] : "NONE");
4123 if (redir->rd_type == REDIRECT_HEREDOC) {
4126 redir->rd_type = REDIRECT_HEREDOC2;
4127 /* redir->rd_dup is (ab)used to indicate <<- */
4128 p = fetch_till_str(&ctx->as_string, input,
4129 redir->rd_filename, redir->rd_dup);
4131 syntax_error("unexpected EOF in here document");
4134 free(redir->rd_filename);
4135 redir->rd_filename = p;
4138 redir = redir->next;
4145 /* Should be 0. If it isn't, it's a parse error */
4147 bb_error_msg_and_die("heredoc BUG 2");
4153 static int run_list(struct pipe *pi);
4155 #define parse_stream(pstring, input, end_trigger) \
4156 parse_stream(input, end_trigger)
4158 static struct pipe *parse_stream(char **pstring,
4159 struct in_str *input,
4163 #if !ENABLE_HUSH_FUNCTIONS
4164 #define parse_group(dest, ctx, input, ch) \
4165 parse_group(ctx, input, ch)
4167 static int parse_group(o_string *dest, struct parse_context *ctx,
4168 struct in_str *input, int ch)
4170 /* dest contains characters seen prior to ( or {.
4171 * Typically it's empty, but for function defs,
4172 * it contains function name (without '()'). */
4173 struct pipe *pipe_list;
4175 struct command *command = ctx->command;
4177 debug_printf_parse("parse_group entered\n");
4178 #if ENABLE_HUSH_FUNCTIONS
4179 if (ch == '(' && !dest->has_quoted_part) {
4181 if (done_word(dest, ctx))
4184 goto skip; /* (... */
4185 if (command->argv[1]) { /* word word ... (... */
4186 syntax_error_unexpected_ch('(');
4189 /* it is "word(..." or "word (..." */
4191 ch = i_getch(input);
4192 while (ch == ' ' || ch == '\t');
4194 syntax_error_unexpected_ch(ch);
4197 nommu_addchr(&ctx->as_string, ch);
4199 ch = i_getch(input);
4200 while (ch == ' ' || ch == '\t' || ch == '\n');
4202 syntax_error_unexpected_ch(ch);
4205 nommu_addchr(&ctx->as_string, ch);
4206 command->cmd_type = CMD_FUNCDEF;
4211 #if 0 /* Prevented by caller */
4212 if (command->argv /* word [word]{... */
4213 || dest->length /* word{... */
4214 || dest->has_quoted_part /* ""{... */
4217 debug_printf_parse("parse_group return 1: "
4218 "syntax error, groups and arglists don't mix\n");
4223 #if ENABLE_HUSH_FUNCTIONS
4229 command->cmd_type = CMD_SUBSHELL;
4231 /* bash does not allow "{echo...", requires whitespace */
4233 if (ch != ' ' && ch != '\t' && ch != '\n'
4234 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4236 syntax_error_unexpected_ch(ch);
4240 ch = i_getch(input);
4241 nommu_addchr(&ctx->as_string, ch);
4247 # define as_string NULL
4249 char *as_string = NULL;
4251 pipe_list = parse_stream(&as_string, input, endch);
4254 o_addstr(&ctx->as_string, as_string);
4256 /* empty ()/{} or parse error? */
4257 if (!pipe_list || pipe_list == ERR_PTR) {
4258 /* parse_stream already emitted error msg */
4261 debug_printf_parse("parse_group return 1: "
4262 "parse_stream returned %p\n", pipe_list);
4265 command->group = pipe_list;
4267 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4268 command->group_as_string = as_string;
4269 debug_printf_parse("end of group, remembering as:'%s'\n",
4270 command->group_as_string);
4274 debug_printf_parse("parse_group return 0\n");
4276 /* command remains "open", available for possible redirects */
4279 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4284 ch = i_getch(input);
4287 ch2 = i_peek(input);
4290 /* backslash+newline, skip it */
4295 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4303 ch2 = i_peek2(input);
4306 /* backslash+newline, skip it */
4312 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4313 /* Subroutines for copying $(...) and `...` things */
4314 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4316 static int add_till_single_quote(o_string *dest, struct in_str *input)
4319 int ch = i_getch(input);
4321 syntax_error_unterm_ch('\'');
4329 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4330 static int add_till_double_quote(o_string *dest, struct in_str *input)
4333 int ch = i_getch(input);
4335 syntax_error_unterm_ch('"');
4340 if (ch == '\\') { /* \x. Copy both chars. */
4342 ch = i_getch(input);
4346 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4351 //if (ch == '$') ...
4354 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4356 * "Within the backquoted style of command substitution, backslash
4357 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4358 * The search for the matching backquote shall be satisfied by the first
4359 * backquote found without a preceding backslash; during this search,
4360 * if a non-escaped backquote is encountered within a shell comment,
4361 * a here-document, an embedded command substitution of the $(command)
4362 * form, or a quoted string, undefined results occur. A single-quoted
4363 * or double-quoted string that begins, but does not end, within the
4364 * "`...`" sequence produces undefined results."
4366 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4368 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4371 int ch = i_getch(input);
4375 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4376 ch = i_getch(input);
4380 && (!in_dquote || ch != '"')
4382 o_addchr(dest, '\\');
4386 syntax_error_unterm_ch('`');
4392 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4393 * quoting and nested ()s.
4394 * "With the $(command) style of command substitution, all characters
4395 * following the open parenthesis to the matching closing parenthesis
4396 * constitute the command. Any valid shell script can be used for command,
4397 * except a script consisting solely of redirections which produces
4398 * unspecified results."
4400 * echo $(echo '(TEST)' BEST) (TEST) BEST
4401 * echo $(echo 'TEST)' BEST) TEST) BEST
4402 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4404 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4405 * can contain arbitrary constructs, just like $(cmd).
4406 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4407 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4409 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4410 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4413 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4414 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4415 char end_char2 = end_ch >> 8;
4417 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4420 ch = i_getch(input);
4422 syntax_error_unterm_ch(end_ch);
4426 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4432 /* we look for closing )) of $((EXPR)) */
4433 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4434 i_getch(input); /* eat second ')' */
4439 if (ch == '(' || ch == '{') {
4440 ch = (ch == '(' ? ')' : '}');
4441 if (!add_till_closing_bracket(dest, input, ch))
4447 if (!add_till_single_quote(dest, input))
4453 if (!add_till_double_quote(dest, input))
4459 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4465 /* \x. Copy verbatim. Important for \(, \) */
4466 ch = i_getch(input);
4468 syntax_error_unterm_ch(')');
4473 /* "backslash+newline", ignore both */
4474 o_delchr(dest); /* undo insertion of '\' */
4484 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4486 /* Return code: 0 for OK, 1 for syntax error */
4488 #define parse_dollar(as_string, dest, input, quote_mask) \
4489 parse_dollar(dest, input, quote_mask)
4490 #define as_string NULL
4492 static int parse_dollar(o_string *as_string,
4494 struct in_str *input, unsigned char quote_mask)
4496 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4498 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4500 ch = i_getch(input);
4501 nommu_addchr(as_string, ch);
4503 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4505 debug_printf_parse(": '%c'\n", ch);
4506 o_addchr(dest, ch | quote_mask);
4508 ch = i_peek_and_eat_bkslash_nl(input);
4509 if (!isalnum(ch) && ch != '_') {
4510 /* End of variable name reached */
4513 ch = i_getch(input);
4514 nommu_addchr(as_string, ch);
4516 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4517 } else if (isdigit(ch)) {
4519 ch = i_getch(input);
4520 nommu_addchr(as_string, ch);
4521 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4522 debug_printf_parse(": '%c'\n", ch);
4523 o_addchr(dest, ch | quote_mask);
4524 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4525 } else switch (ch) {
4527 case '!': /* last bg pid */
4528 case '?': /* last exit code */
4529 case '#': /* number of args */
4530 case '*': /* args */
4531 case '@': /* args */
4532 goto make_one_char_var;
4536 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4538 ch = i_getch(input); /* eat '{' */
4539 nommu_addchr(as_string, ch);
4541 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4542 /* It should be ${?}, or ${#var},
4543 * or even ${?+subst} - operator acting on a special variable,
4544 * or the beginning of variable name.
4547 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4550 syntax_error_unterm_str("${name}");
4551 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4554 nommu_addchr(as_string, ch);
4558 /* It's possible to just call add_till_closing_bracket() at this point.
4559 * However, this regresses some of our testsuite cases
4560 * which check invalid constructs like ${%}.
4561 * Oh well... let's check that the var name part is fine... */
4567 debug_printf_parse(": '%c'\n", ch);
4569 ch = i_getch(input);
4570 nommu_addchr(as_string, ch);
4574 if (!isalnum(ch) && ch != '_') {
4576 unsigned char last_ch;
4577 /* handle parameter expansions
4578 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4580 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4581 if (len_single_ch != '#'
4582 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4583 || i_peek(input) != '}'
4585 goto bad_dollar_syntax;
4587 /* else: it's "length of C" ${#C} op,
4588 * where C is a single char
4589 * special var name, e.g. ${#!}.
4592 /* Eat everything until closing '}' (or ':') */
4596 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4598 /* It's ${var:N[:M]} thing */
4599 end_ch = '}' * 0x100 + ':';
4601 if (BASH_PATTERN_SUBST
4604 /* It's ${var/[/]pattern[/repl]} thing */
4605 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4607 nommu_addchr(as_string, '/');
4610 end_ch = '}' * 0x100 + '/';
4616 #if ENABLE_HUSH_DOLLAR_OPS
4617 last_ch = add_till_closing_bracket(dest, input, end_ch);
4618 if (last_ch == 0) /* error? */
4621 #error Simple code to only allow ${var} is not implemented
4624 o_addstr(as_string, dest->data + pos);
4625 o_addchr(as_string, last_ch);
4628 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4629 && (end_ch & 0xff00)
4631 /* close the first block: */
4632 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4633 /* while parsing N from ${var:N[:M]}
4634 * or pattern from ${var/[/]pattern[/repl]} */
4635 if ((end_ch & 0xff) == last_ch) {
4636 /* got ':' or '/'- parse the rest */
4641 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4642 /* it's ${var:N} - emulate :999999999 */
4643 o_addstr(dest, "999999999");
4644 } /* else: it's ${var/[/]pattern} */
4648 len_single_ch = 0; /* it can't be ${#C} op */
4650 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4653 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4657 ch = i_getch(input);
4658 nommu_addchr(as_string, ch);
4659 # if ENABLE_FEATURE_SH_MATH
4660 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4661 ch = i_getch(input);
4662 nommu_addchr(as_string, ch);
4663 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4664 o_addchr(dest, /*quote_mask |*/ '+');
4667 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4668 return 0; /* error */
4670 o_addstr(as_string, dest->data + pos);
4671 o_addchr(as_string, ')');
4672 o_addchr(as_string, ')');
4674 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4678 # if ENABLE_HUSH_TICK
4679 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4680 o_addchr(dest, quote_mask | '`');
4683 if (!add_till_closing_bracket(dest, input, ')'))
4684 return 0; /* error */
4686 o_addstr(as_string, dest->data + pos);
4687 o_addchr(as_string, ')');
4689 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4695 ch = i_getch(input);
4696 nommu_addchr(as_string, ch);
4697 ch = i_peek_and_eat_bkslash_nl(input);
4698 if (isalnum(ch)) { /* it's $_name or $_123 */
4703 /* TODO: $_ and $-: */
4704 /* $_ Shell or shell script name; or last argument of last command
4705 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4706 * but in command's env, set to full pathname used to invoke it */
4707 /* $- Option flags set by set builtin or shell options (-i etc) */
4709 o_addQchr(dest, '$');
4711 debug_printf_parse("parse_dollar return 1 (ok)\n");
4717 # if BASH_PATTERN_SUBST
4718 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4719 encode_string(dest, input, dquote_end, process_bkslash)
4721 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4722 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4723 encode_string(dest, input, dquote_end)
4725 #define as_string NULL
4729 # if BASH_PATTERN_SUBST
4730 /* all parameters are needed, no macro tricks */
4732 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4733 encode_string(as_string, dest, input, dquote_end)
4736 static int encode_string(o_string *as_string,
4738 struct in_str *input,
4740 int process_bkslash)
4742 #if !BASH_PATTERN_SUBST
4743 const int process_bkslash = 1;
4749 ch = i_getch(input);
4751 nommu_addchr(as_string, ch);
4752 if (ch == dquote_end) { /* may be only '"' or EOF */
4753 debug_printf_parse("encode_string return 1 (ok)\n");
4756 /* note: can't move it above ch == dquote_end check! */
4758 syntax_error_unterm_ch('"');
4759 return 0; /* error */
4763 next = i_peek(input);
4765 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4766 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4767 if (process_bkslash && ch == '\\') {
4769 syntax_error("\\<eof>");
4773 * "The backslash retains its special meaning [in "..."]
4774 * only when followed by one of the following characters:
4775 * $, `, ", \, or <newline>. A double quote may be quoted
4776 * within double quotes by preceding it with a backslash."
4777 * NB: in (unquoted) heredoc, above does not apply to ",
4778 * therefore we check for it by "next == dquote_end" cond.
4780 if (next == dquote_end || strchr("$`\\\n", next)) {
4781 ch = i_getch(input); /* eat next */
4783 goto again; /* skip \<newline> */
4784 } /* else: ch remains == '\\', and we double it below: */
4785 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4786 nommu_addchr(as_string, ch);
4790 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4791 debug_printf_parse("encode_string return 0: "
4792 "parse_dollar returned 0 (error)\n");
4797 #if ENABLE_HUSH_TICK
4799 //unsigned pos = dest->length;
4800 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4801 o_addchr(dest, 0x80 | '`');
4802 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4803 return 0; /* error */
4804 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4805 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4809 o_addQchr(dest, ch);
4815 * Scan input until EOF or end_trigger char.
4816 * Return a list of pipes to execute, or NULL on EOF
4817 * or if end_trigger character is met.
4818 * On syntax error, exit if shell is not interactive,
4819 * reset parsing machinery and start parsing anew,
4820 * or return ERR_PTR.
4822 static struct pipe *parse_stream(char **pstring,
4823 struct in_str *input,
4826 struct parse_context ctx;
4827 o_string dest = NULL_O_STRING;
4830 /* Single-quote triggers a bypass of the main loop until its mate is
4831 * found. When recursing, quote state is passed in via dest->o_expflags.
4833 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4834 end_trigger ? end_trigger : 'X');
4837 /* If very first arg is "" or '', dest.data may end up NULL.
4838 * Preventing this: */
4839 o_addchr(&dest, '\0');
4842 /* We used to separate words on $IFS here. This was wrong.
4843 * $IFS is used only for word splitting when $var is expanded,
4844 * here we should use blank chars as separators, not $IFS
4847 if (MAYBE_ASSIGNMENT != 0)
4848 dest.o_assignment = MAYBE_ASSIGNMENT;
4849 initialize_context(&ctx);
4852 const char *is_blank;
4853 const char *is_special;
4857 redir_type redir_style;
4859 ch = i_getch(input);
4860 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4861 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4866 syntax_error_unterm_str("here document");
4869 if (end_trigger == ')') {
4870 syntax_error_unterm_ch('(');
4873 if (end_trigger == '}') {
4874 syntax_error_unterm_ch('{');
4878 if (done_word(&dest, &ctx)) {
4882 done_pipe(&ctx, PIPE_SEQ);
4884 /* If we got nothing... */
4885 /* (this makes bare "&" cmd a no-op.
4886 * bash says: "syntax error near unexpected token '&'") */
4887 if (pi->num_cmds == 0
4888 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4894 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4896 *pstring = ctx.as_string.data;
4898 o_free_unsafe(&ctx.as_string);
4901 debug_printf_parse("parse_stream return %p\n", pi);
4904 nommu_addchr(&ctx.as_string, ch);
4908 next = i_peek(input);
4910 is_special = "{}<>;&|()#'" /* special outside of "str" */
4911 "\\$\"" IF_HUSH_TICK("`") /* always special */
4912 SPECIAL_VAR_SYMBOL_STR;
4913 /* Are { and } special here? */
4914 if (ctx.command->argv /* word [word]{... - non-special */
4915 || dest.length /* word{... - non-special */
4916 || dest.has_quoted_part /* ""{... - non-special */
4917 || (next != ';' /* }; - special */
4918 && next != ')' /* }) - special */
4919 && next != '(' /* {( - special */
4920 && next != '&' /* }& and }&& ... - special */
4921 && next != '|' /* }|| ... - special */
4922 && !strchr(defifs, next) /* {word - non-special */
4925 /* They are not special, skip "{}" */
4928 is_special = strchr(is_special, ch);
4929 is_blank = strchr(defifs, ch);
4931 if (!is_special && !is_blank) { /* ordinary char */
4933 o_addQchr(&dest, ch);
4934 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4935 || dest.o_assignment == WORD_IS_KEYWORD)
4937 && is_well_formed_var_name(dest.data, '=')
4939 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4940 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4946 if (done_word(&dest, &ctx)) {
4950 /* Is this a case when newline is simply ignored?
4952 * "cmd | <newline> cmd ..."
4953 * "case ... in <newline> word) ..."
4955 if (IS_NULL_CMD(ctx.command)
4956 && dest.length == 0 && !dest.has_quoted_part
4958 /* This newline can be ignored. But...
4959 * Without check #1, interactive shell
4960 * ignores even bare <newline>,
4961 * and shows the continuation prompt:
4962 * ps1_prompt$ <enter>
4963 * ps2> _ <=== wrong, should be ps1
4964 * Without check #2, "cmd & <newline>"
4965 * is similarly mistreated.
4966 * (BTW, this makes "cmd & cmd"
4967 * and "cmd && cmd" non-orthogonal.
4968 * Really, ask yourself, why
4969 * "cmd && <newline>" doesn't start
4970 * cmd but waits for more input?
4971 * The only reason is that it might be
4972 * a "cmd1 && <nl> cmd2 &" construct,
4973 * cmd1 may need to run in BG).
4975 struct pipe *pi = ctx.list_head;
4976 if (pi->num_cmds != 0 /* check #1 */
4977 && pi->followup != PIPE_BG /* check #2 */
4982 /* Treat newline as a command separator. */
4983 done_pipe(&ctx, PIPE_SEQ);
4984 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4986 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4991 dest.o_assignment = MAYBE_ASSIGNMENT;
4992 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4994 /* note: if (is_blank) continue;
4995 * will still trigger for us */
4999 /* "cmd}" or "cmd }..." without semicolon or &:
5000 * } is an ordinary char in this case, even inside { cmd; }
5001 * Pathological example: { ""}; } should exec "}" cmd
5004 if (dest.length != 0 /* word} */
5005 || dest.has_quoted_part /* ""} */
5009 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
5010 /* Generally, there should be semicolon: "cmd; }"
5011 * However, bash allows to omit it if "cmd" is
5012 * a group. Examples:
5015 * { echo 0 >&2 | { echo 1; } }
5016 * { while false; do :; done }
5017 * { case a in b) ;; esac }
5019 if (ctx.command->group)
5023 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5024 /* Can't be an end of {cmd}, skip the check */
5025 goto skip_end_trigger;
5026 /* else: } does terminate a group */
5029 if (end_trigger && end_trigger == ch
5030 && (ch != ';' || heredoc_cnt == 0)
5031 #if ENABLE_HUSH_CASE
5033 || ctx.ctx_res_w != RES_MATCH
5034 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5039 /* This is technically valid:
5040 * { cat <<HERE; }; echo Ok
5044 * but we don't support this.
5045 * We require heredoc to be in enclosing {}/(),
5048 syntax_error_unterm_str("here document");
5051 if (done_word(&dest, &ctx)) {
5054 done_pipe(&ctx, PIPE_SEQ);
5055 dest.o_assignment = MAYBE_ASSIGNMENT;
5056 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5057 /* Do we sit outside of any if's, loops or case's? */
5059 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5063 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5065 *pstring = ctx.as_string.data;
5067 o_free_unsafe(&ctx.as_string);
5069 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5070 /* Example: bare "{ }", "()" */
5071 G.last_exitcode = 2; /* bash compat */
5072 syntax_error_unexpected_ch(ch);
5075 debug_printf_parse("parse_stream return %p: "
5076 "end_trigger char found\n",
5079 return ctx.list_head;
5086 /* Catch <, > before deciding whether this word is
5087 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5090 redir_fd = redirect_opt_num(&dest);
5091 if (done_word(&dest, &ctx)) {
5094 redir_style = REDIRECT_OVERWRITE;
5096 redir_style = REDIRECT_APPEND;
5097 ch = i_getch(input);
5098 nommu_addchr(&ctx.as_string, ch);
5101 else if (next == '(') {
5102 syntax_error(">(process) not supported");
5106 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5108 continue; /* back to top of while (1) */
5110 redir_fd = redirect_opt_num(&dest);
5111 if (done_word(&dest, &ctx)) {
5114 redir_style = REDIRECT_INPUT;
5116 redir_style = REDIRECT_HEREDOC;
5118 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5119 ch = i_getch(input);
5120 nommu_addchr(&ctx.as_string, ch);
5121 } else if (next == '>') {
5122 redir_style = REDIRECT_IO;
5123 ch = i_getch(input);
5124 nommu_addchr(&ctx.as_string, ch);
5127 else if (next == '(') {
5128 syntax_error("<(process) not supported");
5132 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5134 continue; /* back to top of while (1) */
5136 if (dest.length == 0 && !dest.has_quoted_part) {
5137 /* skip "#comment" */
5138 /* note: we do not add it to &ctx.as_string */
5140 * comment inside $() goes to the next \n, even inside quoted string (!):
5141 * cmd "$(cmd2 #comment)" - syntax error
5142 * cmd "`cmd2 #comment`" - ok
5143 * We accept both (comment ends where command subst ends, in both cases).
5148 nommu_addchr(&ctx.as_string, '\n');
5151 ch = i_getch(input);
5155 continue; /* back to top of while (1) */
5160 /* It's "\<newline>" */
5162 /* Remove trailing '\' from ctx.as_string */
5163 ctx.as_string.data[--ctx.as_string.length] = '\0';
5165 ch = i_getch(input); /* eat it */
5166 continue; /* back to top of while (1) */
5171 if (dest.o_assignment == MAYBE_ASSIGNMENT
5172 /* check that we are not in word in "a=1 2>word b=1": */
5173 && !ctx.pending_redirect
5175 /* ch is a special char and thus this word
5176 * cannot be an assignment */
5177 dest.o_assignment = NOT_ASSIGNMENT;
5178 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5181 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5184 case SPECIAL_VAR_SYMBOL:
5185 /* Convert raw ^C to corresponding special variable reference */
5186 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5187 o_addchr(&dest, SPECIAL_VAR_QUOTED_SVS);
5190 /* non-comment #: "echo a#b" etc */
5191 o_addchr(&dest, ch);
5195 syntax_error("\\<eof>");
5198 ch = i_getch(input);
5199 /* note: ch != '\n' (that case does not reach this place) */
5200 o_addchr(&dest, '\\');
5201 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5202 o_addchr(&dest, ch);
5203 nommu_addchr(&ctx.as_string, ch);
5204 /* Example: echo Hello \2>file
5205 * we need to know that word 2 is quoted */
5206 dest.has_quoted_part = 1;
5209 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5210 debug_printf_parse("parse_stream parse error: "
5211 "parse_dollar returned 0 (error)\n");
5216 dest.has_quoted_part = 1;
5217 if (next == '\'' && !ctx.pending_redirect) {
5218 insert_empty_quoted_str_marker:
5219 nommu_addchr(&ctx.as_string, next);
5220 i_getch(input); /* eat second ' */
5221 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5222 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5225 ch = i_getch(input);
5227 syntax_error_unterm_ch('\'');
5230 nommu_addchr(&ctx.as_string, ch);
5233 o_addqchr(&dest, ch);
5238 dest.has_quoted_part = 1;
5239 if (next == '"' && !ctx.pending_redirect)
5240 goto insert_empty_quoted_str_marker;
5241 if (dest.o_assignment == NOT_ASSIGNMENT)
5242 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5243 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5245 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5247 #if ENABLE_HUSH_TICK
5249 USE_FOR_NOMMU(unsigned pos;)
5251 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5252 o_addchr(&dest, '`');
5253 USE_FOR_NOMMU(pos = dest.length;)
5254 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5257 o_addstr(&ctx.as_string, dest.data + pos);
5258 o_addchr(&ctx.as_string, '`');
5260 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5261 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5266 #if ENABLE_HUSH_CASE
5269 if (done_word(&dest, &ctx)) {
5272 done_pipe(&ctx, PIPE_SEQ);
5273 #if ENABLE_HUSH_CASE
5274 /* Eat multiple semicolons, detect
5275 * whether it means something special */
5280 ch = i_getch(input);
5281 nommu_addchr(&ctx.as_string, ch);
5282 if (ctx.ctx_res_w == RES_CASE_BODY) {
5283 ctx.ctx_dsemicolon = 1;
5284 ctx.ctx_res_w = RES_MATCH;
5290 /* We just finished a cmd. New one may start
5291 * with an assignment */
5292 dest.o_assignment = MAYBE_ASSIGNMENT;
5293 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5296 if (done_word(&dest, &ctx)) {
5300 ch = i_getch(input);
5301 nommu_addchr(&ctx.as_string, ch);
5302 done_pipe(&ctx, PIPE_AND);
5304 done_pipe(&ctx, PIPE_BG);
5308 if (done_word(&dest, &ctx)) {
5311 #if ENABLE_HUSH_CASE
5312 if (ctx.ctx_res_w == RES_MATCH)
5313 break; /* we are in case's "word | word)" */
5315 if (next == '|') { /* || */
5316 ch = i_getch(input);
5317 nommu_addchr(&ctx.as_string, ch);
5318 done_pipe(&ctx, PIPE_OR);
5320 /* we could pick up a file descriptor choice here
5321 * with redirect_opt_num(), but bash doesn't do it.
5322 * "echo foo 2| cat" yields "foo 2". */
5327 #if ENABLE_HUSH_CASE
5328 /* "case... in [(]word)..." - skip '(' */
5329 if (ctx.ctx_res_w == RES_MATCH
5330 && ctx.command->argv == NULL /* not (word|(... */
5331 && dest.length == 0 /* not word(... */
5332 && dest.has_quoted_part == 0 /* not ""(... */
5338 if (parse_group(&dest, &ctx, input, ch) != 0) {
5343 #if ENABLE_HUSH_CASE
5344 if (ctx.ctx_res_w == RES_MATCH)
5348 /* proper use of this character is caught by end_trigger:
5349 * if we see {, we call parse_group(..., end_trigger='}')
5350 * and it will match } earlier (not here). */
5351 G.last_exitcode = 2;
5352 syntax_error_unexpected_ch(ch);
5356 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5361 G.last_exitcode = 1;
5364 struct parse_context *pctx;
5365 IF_HAS_KEYWORDS(struct parse_context *p2;)
5367 /* Clean up allocated tree.
5368 * Sample for finding leaks on syntax error recovery path.
5369 * Run it from interactive shell, watch pmap `pidof hush`.
5370 * while if false; then false; fi; do break; fi
5371 * Samples to catch leaks at execution:
5372 * while if (true | { true;}); then echo ok; fi; do break; done
5373 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5377 /* Update pipe/command counts,
5378 * otherwise freeing may miss some */
5379 done_pipe(pctx, PIPE_SEQ);
5380 debug_printf_clean("freeing list %p from ctx %p\n",
5381 pctx->list_head, pctx);
5382 debug_print_tree(pctx->list_head, 0);
5383 free_pipe_list(pctx->list_head);
5384 debug_printf_clean("freed list %p\n", pctx->list_head);
5386 o_free_unsafe(&pctx->as_string);
5388 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5392 IF_HAS_KEYWORDS(pctx = p2;)
5393 } while (HAS_KEYWORDS && pctx);
5406 /*** Execution routines ***/
5408 /* Expansion can recurse, need forward decls: */
5409 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5410 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5411 #define expand_string_to_string(str, do_unbackslash) \
5412 expand_string_to_string(str)
5414 static char *expand_string_to_string(const char *str, int do_unbackslash);
5415 #if ENABLE_HUSH_TICK
5416 static int process_command_subs(o_string *dest, const char *s);
5419 /* expand_strvec_to_strvec() takes a list of strings, expands
5420 * all variable references within and returns a pointer to
5421 * a list of expanded strings, possibly with larger number
5422 * of strings. (Think VAR="a b"; echo $VAR).
5423 * This new list is allocated as a single malloc block.
5424 * NULL-terminated list of char* pointers is at the beginning of it,
5425 * followed by strings themselves.
5426 * Caller can deallocate entire list by single free(list). */
5428 /* A horde of its helpers come first: */
5430 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5432 while (--len >= 0) {
5435 #if ENABLE_HUSH_BRACE_EXPANSION
5436 if (c == '{' || c == '}') {
5437 /* { -> \{, } -> \} */
5439 /* And now we want to add { or } and continue:
5442 * luckily, just falling through achieves this.
5448 /* \z -> \\\z; \<eol> -> \\<eol> */
5453 o_addchr(o, *str++);
5459 /* Store given string, finalizing the word and starting new one whenever
5460 * we encounter IFS char(s). This is used for expanding variable values.
5461 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5462 * Return in *ended_with_ifs:
5463 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5465 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5467 int last_is_ifs = 0;
5472 if (!*str) /* EOL - do not finalize word */
5474 word_len = strcspn(str, G.ifs);
5476 /* We have WORD_LEN leading non-IFS chars */
5477 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5478 o_addblock(output, str, word_len);
5480 /* Protect backslashes against globbing up :)
5481 * Example: "v='\*'; echo b$v" prints "b\*"
5482 * (and does not try to glob on "*")
5484 o_addblock_duplicate_backslash(output, str, word_len);
5485 /*/ Why can't we do it easier? */
5486 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5487 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5491 if (!*str) /* EOL - do not finalize word */
5495 /* We know str here points to at least one IFS char */
5497 str += strspn(str, G.ifs); /* skip IFS chars */
5498 if (!*str) /* EOL - do not finalize word */
5501 /* Start new word... but not always! */
5502 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5503 if (output->has_quoted_part
5504 /* Case "v=' a'; echo $v":
5505 * here nothing precedes the space in $v expansion,
5506 * therefore we should not finish the word
5507 * (IOW: if there *is* word to finalize, only then do it):
5509 || (n > 0 && output->data[output->length - 1])
5511 o_addchr(output, '\0');
5512 debug_print_list("expand_on_ifs", output, n);
5513 n = o_save_ptr(output, n);
5518 *ended_with_ifs = last_is_ifs;
5519 debug_print_list("expand_on_ifs[1]", output, n);
5523 /* Helper to expand $((...)) and heredoc body. These act as if
5524 * they are in double quotes, with the exception that they are not :).
5525 * Just the rules are similar: "expand only $var and `cmd`"
5527 * Returns malloced string.
5528 * As an optimization, we return NULL if expansion is not needed.
5530 #if !BASH_PATTERN_SUBST
5531 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5532 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5533 encode_then_expand_string(str)
5535 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5537 #if !BASH_PATTERN_SUBST
5538 enum { do_unbackslash = 1 };
5541 struct in_str input;
5542 o_string dest = NULL_O_STRING;
5544 if (!strchr(str, '$')
5545 && !strchr(str, '\\')
5546 #if ENABLE_HUSH_TICK
5547 && !strchr(str, '`')
5553 /* We need to expand. Example:
5554 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5556 setup_string_in_str(&input, str);
5557 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5558 //TODO: error check (encode_string returns 0 on error)?
5559 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5560 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5561 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5562 o_free_unsafe(&dest);
5566 #if ENABLE_FEATURE_SH_MATH
5567 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5569 arith_state_t math_state;
5573 math_state.lookupvar = get_local_var_value;
5574 math_state.setvar = set_local_var_from_halves;
5575 //math_state.endofname = endofname;
5576 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5577 res = arith(&math_state, exp_str ? exp_str : arg);
5580 *errmsg_p = math_state.errmsg;
5581 if (math_state.errmsg)
5582 msg_and_die_if_script(math_state.errmsg);
5587 #if BASH_PATTERN_SUBST
5588 /* ${var/[/]pattern[/repl]} helpers */
5589 static char *strstr_pattern(char *val, const char *pattern, int *size)
5592 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5593 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5600 /* Optimization: if "*pat" did not match the start of "string",
5601 * we know that "tring", "ring" etc will not match too:
5603 if (pattern[0] == '*')
5608 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5610 char *result = NULL;
5611 unsigned res_len = 0;
5612 unsigned repl_len = strlen(repl);
5616 char *s = strstr_pattern(val, pattern, &size);
5620 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5621 strcpy(mempcpy(result + res_len, val, s - val), repl);
5622 res_len += (s - val) + repl_len;
5623 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5629 if (*val && result) {
5630 result = xrealloc(result, res_len + strlen(val) + 1);
5631 strcpy(result + res_len, val);
5632 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5634 debug_printf_varexp("result:'%s'\n", result);
5637 #endif /* BASH_PATTERN_SUBST */
5640 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5642 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5644 const char *val = NULL;
5645 char *to_be_freed = NULL;
5650 char exp_save = exp_save; /* for compiler */
5651 char *exp_saveptr; /* points to expansion operator */
5652 char *exp_word = exp_word; /* for compiler */
5655 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5657 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5659 first_char = arg[0] = arg0 & 0x7f;
5662 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5663 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5664 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5665 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5667 /* It must be length operator: ${#var} */
5671 /* Maybe handle parameter expansion */
5672 if (exp_saveptr /* if 2nd char is one of expansion operators */
5673 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5675 /* ${?:0}, ${#[:]%0} etc */
5676 exp_saveptr = var + 1;
5678 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5679 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5681 exp_op = exp_save = *exp_saveptr;
5683 exp_word = exp_saveptr + 1;
5684 if (exp_op == ':') {
5685 exp_op = *exp_word++;
5686 //TODO: try ${var:} and ${var:bogus} in non-bash config
5688 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5690 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5695 *exp_saveptr = '\0';
5696 } /* else: it's not an expansion op, but bare ${var} */
5699 /* Look up the variable in question */
5700 if (isdigit(var[0])) {
5701 /* parse_dollar should have vetted var for us */
5702 int n = xatoi_positive(var);
5703 if (n < G.global_argc)
5704 val = G.global_argv[n];
5705 /* else val remains NULL: $N with too big N */
5709 val = utoa(G.root_pid);
5711 case '!': /* bg pid */
5712 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5714 case '?': /* exitcode */
5715 val = utoa(G.last_exitcode);
5717 case '#': /* argc */
5718 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5721 val = get_local_var_value(var);
5725 /* Handle any expansions */
5726 if (exp_op == 'L') {
5727 reinit_unicode_for_hush();
5728 debug_printf_expand("expand: length(%s)=", val);
5729 val = utoa(val ? unicode_strlen(val) : 0);
5730 debug_printf_expand("%s\n", val);
5731 } else if (exp_op) {
5732 if (exp_op == '%' || exp_op == '#') {
5733 /* Standard-mandated substring removal ops:
5734 * ${parameter%word} - remove smallest suffix pattern
5735 * ${parameter%%word} - remove largest suffix pattern
5736 * ${parameter#word} - remove smallest prefix pattern
5737 * ${parameter##word} - remove largest prefix pattern
5739 * Word is expanded to produce a glob pattern.
5740 * Then var's value is matched to it and matching part removed.
5742 if (val && val[0]) {
5746 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5747 if (exp_op == *exp_word) /* ## or %% */
5749 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5751 exp_word = exp_exp_word;
5752 /* HACK ALERT. We depend here on the fact that
5753 * G.global_argv and results of utoa and get_local_var_value
5754 * are actually in writable memory:
5755 * scan_and_match momentarily stores NULs there. */
5757 loc = scan_and_match(t, exp_word, scan_flags);
5758 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5759 // exp_op, t, exp_word, loc);
5761 if (loc) { /* match was found */
5762 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5763 val = loc; /* take right part */
5765 val = to_be_freed = xstrndup(val, loc - val); /* left */
5769 #if BASH_PATTERN_SUBST
5770 else if (exp_op == '/' || exp_op == '\\') {
5771 /* It's ${var/[/]pattern[/repl]} thing.
5772 * Note that in encoded form it has TWO parts:
5773 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5774 * and if // is used, it is encoded as \:
5775 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5777 /* Empty variable always gives nothing: */
5778 // "v=''; echo ${v/*/w}" prints "", not "w"
5779 if (val && val[0]) {
5780 /* pattern uses non-standard expansion.
5781 * repl should be unbackslashed and globbed
5782 * by the usual expansion rules:
5784 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5785 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5786 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5787 * v='a bz'; echo ${v/a*z/\z} prints "z"
5788 * (note that a*z _pattern_ is never globbed!)
5790 char *pattern, *repl, *t;
5791 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5793 pattern = xstrdup(exp_word);
5794 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5795 *p++ = SPECIAL_VAR_SYMBOL;
5797 p = strchr(p, SPECIAL_VAR_SYMBOL);
5799 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5800 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5801 /* HACK ALERT. We depend here on the fact that
5802 * G.global_argv and results of utoa and get_local_var_value
5803 * are actually in writable memory:
5804 * replace_pattern momentarily stores NULs there. */
5806 to_be_freed = replace_pattern(t,
5808 (repl ? repl : exp_word),
5810 if (to_be_freed) /* at least one replace happened */
5816 #endif /* BASH_PATTERN_SUBST */
5817 else if (exp_op == ':') {
5818 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5819 /* It's ${var:N[:M]} bashism.
5820 * Note that in encoded form it has TWO parts:
5821 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5826 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5829 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5830 *p++ = SPECIAL_VAR_SYMBOL;
5832 p = strchr(p, SPECIAL_VAR_SYMBOL);
5834 len = expand_and_evaluate_arith(exp_word, &errmsg);
5837 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5839 /* negative beg counts from the end */
5840 beg = (arith_t)strlen(val) + beg;
5841 if (beg < 0) /* ${v: -999999} is "" */
5844 debug_printf_varexp("from val:'%s'\n", val);
5846 /* in bash, len=-n means strlen()-n */
5847 len = (arith_t)strlen(val) - beg + len;
5848 if (len < 0) /* bash compat */
5849 msg_and_die_if_script("%s: substring expression < 0", var);
5851 if (len <= 0 || !val || beg >= strlen(val)) {
5855 /* Paranoia. What if user entered 9999999999999
5856 * which fits in arith_t but not int? */
5859 val = to_be_freed = xstrndup(val + beg, len);
5861 debug_printf_varexp("val:'%s'\n", val);
5862 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5863 msg_and_die_if_script("malformed ${%s:...}", var);
5866 } else { /* one of "-=+?" */
5867 /* Standard-mandated substitution ops:
5868 * ${var?word} - indicate error if unset
5869 * If var is unset, word (or a message indicating it is unset
5870 * if word is null) is written to standard error
5871 * and the shell exits with a non-zero exit status.
5872 * Otherwise, the value of var is substituted.
5873 * ${var-word} - use default value
5874 * If var is unset, word is substituted.
5875 * ${var=word} - assign and use default value
5876 * If var is unset, word is assigned to var.
5877 * In all cases, final value of var is substituted.
5878 * ${var+word} - use alternative value
5879 * If var is unset, null is substituted.
5880 * Otherwise, word is substituted.
5882 * Word is subjected to tilde expansion, parameter expansion,
5883 * command substitution, and arithmetic expansion.
5884 * If word is not needed, it is not expanded.
5886 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5887 * but also treat null var as if it is unset.
5889 int use_word = (!val || ((exp_save == ':') && !val[0]));
5891 use_word = !use_word;
5892 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5893 (exp_save == ':') ? "true" : "false", use_word);
5895 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5897 exp_word = to_be_freed;
5898 if (exp_op == '?') {
5899 /* mimic bash message */
5900 msg_and_die_if_script("%s: %s",
5904 : "parameter null or not set"
5905 /* ash has more specific messages, a-la: */
5906 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5908 //TODO: how interactive bash aborts expansion mid-command?
5913 if (exp_op == '=') {
5914 /* ${var=[word]} or ${var:=[word]} */
5915 if (isdigit(var[0]) || var[0] == '#') {
5916 /* mimic bash message */
5917 msg_and_die_if_script("$%s: cannot assign in this way", var);
5920 char *new_var = xasprintf("%s=%s", var, val);
5921 set_local_var(new_var, /*flag:*/ 0);
5925 } /* one of "-=+?" */
5927 *exp_saveptr = exp_save;
5933 *to_be_freed_pp = to_be_freed;
5937 /* Expand all variable references in given string, adding words to list[]
5938 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5939 * to be filled). This routine is extremely tricky: has to deal with
5940 * variables/parameters with whitespace, $* and $@, and constructs like
5941 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5942 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5944 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5945 * expansion of right-hand side of assignment == 1-element expand.
5947 char cant_be_null = 0; /* only bit 0x80 matters */
5948 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5951 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5952 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5953 debug_print_list("expand_vars_to_list", output, n);
5954 n = o_save_ptr(output, n);
5955 debug_print_list("expand_vars_to_list[0]", output, n);
5957 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5959 char *to_be_freed = NULL;
5960 const char *val = NULL;
5961 #if ENABLE_HUSH_TICK
5962 o_string subst_result = NULL_O_STRING;
5964 #if ENABLE_FEATURE_SH_MATH
5965 char arith_buf[sizeof(arith_t)*3 + 2];
5969 o_addchr(output, '\0');
5970 n = o_save_ptr(output, n);
5974 o_addblock(output, arg, p - arg);
5975 debug_print_list("expand_vars_to_list[1]", output, n);
5977 p = strchr(p, SPECIAL_VAR_SYMBOL);
5979 /* Fetch special var name (if it is indeed one of them)
5980 * and quote bit, force the bit on if singleword expansion -
5981 * important for not getting v=$@ expand to many words. */
5982 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5984 /* Is this variable quoted and thus expansion can't be null?
5985 * "$@" is special. Even if quoted, it can still
5986 * expand to nothing (not even an empty string),
5987 * thus it is excluded. */
5988 if ((first_ch & 0x7f) != '@')
5989 cant_be_null |= first_ch;
5991 switch (first_ch & 0x7f) {
5992 /* Highest bit in first_ch indicates that var is double-quoted */
5996 if (!G.global_argv[1])
5999 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
6000 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
6001 while (G.global_argv[i]) {
6002 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
6003 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
6004 if (G.global_argv[i++][0] && G.global_argv[i]) {
6005 /* this argv[] is not empty and not last:
6006 * put terminating NUL, start new word */
6007 o_addchr(output, '\0');
6008 debug_print_list("expand_vars_to_list[2]", output, n);
6009 n = o_save_ptr(output, n);
6010 debug_print_list("expand_vars_to_list[3]", output, n);
6014 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
6015 * and in this case should treat it like '$*' - see 'else...' below */
6016 if (first_ch == ('@'|0x80) /* quoted $@ */
6017 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
6020 o_addQstr(output, G.global_argv[i]);
6021 if (++i >= G.global_argc)
6023 o_addchr(output, '\0');
6024 debug_print_list("expand_vars_to_list[4]", output, n);
6025 n = o_save_ptr(output, n);
6027 } else { /* quoted $* (or v="$@" case): add as one word */
6029 o_addQstr(output, G.global_argv[i]);
6030 if (!G.global_argv[++i])
6033 o_addchr(output, G.ifs[0]);
6035 output->has_quoted_part = 1;
6039 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
6040 /* "Empty variable", used to make "" etc to not disappear */
6041 output->has_quoted_part = 1;
6043 cant_be_null = 0x80;
6045 case SPECIAL_VAR_QUOTED_SVS:
6046 /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_QUOTED_SVS><SPECIAL_VAR_SYMBOL> */
6048 val = SPECIAL_VAR_SYMBOL_STR;
6050 #if ENABLE_HUSH_TICK
6051 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6052 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6054 /* Can't just stuff it into output o_string,
6055 * expanded result may need to be globbed
6057 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6058 G.last_exitcode = process_command_subs(&subst_result, arg);
6059 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6060 val = subst_result.data;
6063 #if ENABLE_FEATURE_SH_MATH
6064 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6067 arg++; /* skip '+' */
6068 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6069 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6070 res = expand_and_evaluate_arith(arg, NULL);
6071 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6072 sprintf(arith_buf, ARITH_FMT, res);
6078 val = expand_one_var(&to_be_freed, arg, &p);
6079 IF_HUSH_TICK(store_val:)
6080 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6081 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6082 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6083 if (val && val[0]) {
6084 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6087 } else { /* quoted $VAR, val will be appended below */
6088 output->has_quoted_part = 1;
6089 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6090 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6093 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6095 if (val && val[0]) {
6096 o_addQstr(output, val);
6100 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6101 * Do the check to avoid writing to a const string. */
6102 if (*p != SPECIAL_VAR_SYMBOL)
6103 *p = SPECIAL_VAR_SYMBOL;
6105 #if ENABLE_HUSH_TICK
6106 o_free(&subst_result);
6109 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6113 o_addchr(output, '\0');
6114 n = o_save_ptr(output, n);
6116 debug_print_list("expand_vars_to_list[a]", output, n);
6117 /* this part is literal, and it was already pre-quoted
6118 * if needed (much earlier), do not use o_addQstr here! */
6119 o_addstr_with_NUL(output, arg);
6120 debug_print_list("expand_vars_to_list[b]", output, n);
6121 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6122 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6125 /* allow to reuse list[n] later without re-growth */
6126 output->has_empty_slot = 1;
6128 o_addchr(output, '\0');
6134 static char **expand_variables(char **argv, unsigned expflags)
6138 o_string output = NULL_O_STRING;
6140 output.o_expflags = expflags;
6144 n = expand_vars_to_list(&output, n, *argv);
6147 debug_print_list("expand_variables", &output, n);
6149 /* output.data (malloced in one block) gets returned in "list" */
6150 list = o_finalize_list(&output, n);
6151 debug_print_strings("expand_variables[1]", list);
6155 static char **expand_strvec_to_strvec(char **argv)
6157 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6161 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6163 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6167 /* Used for expansion of right hand of assignments,
6168 * $((...)), heredocs, variable espansion parts.
6170 * NB: should NOT do globbing!
6171 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6173 static char *expand_string_to_string(const char *str, int do_unbackslash)
6175 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6176 const int do_unbackslash = 1;
6178 char *argv[2], **list;
6180 debug_printf_expand("string_to_string<='%s'\n", str);
6181 /* This is generally an optimization, but it also
6182 * handles "", which otherwise trips over !list[0] check below.
6183 * (is this ever happens that we actually get str="" here?)
6185 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6186 //TODO: Can use on strings with \ too, just unbackslash() them?
6187 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6188 return xstrdup(str);
6191 argv[0] = (char*)str;
6193 list = expand_variables(argv, do_unbackslash
6194 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6195 : EXP_FLAG_SINGLEWORD
6198 if (!list[0] || list[1])
6199 bb_error_msg_and_die("BUG in varexp2");
6200 /* actually, just move string 2*sizeof(char*) bytes back */
6201 overlapping_strcpy((char*)list, list[0]);
6203 unbackslash((char*)list);
6204 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6208 #if ENABLE_HUSH_CASE
6209 static char* expand_strvec_to_string(char **argv)
6213 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6214 /* Convert all NULs to spaces */
6219 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6220 bb_error_msg_and_die("BUG in varexp3");
6221 /* bash uses ' ' regardless of $IFS contents */
6226 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6227 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6232 static char **expand_assignments(char **argv, int count)
6237 G.expanded_assignments = p = NULL;
6238 /* Expand assignments into one string each */
6239 for (i = 0; i < count; i++) {
6240 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6242 G.expanded_assignments = NULL;
6247 static void switch_off_special_sigs(unsigned mask)
6250 while ((mask >>= 1) != 0) {
6254 #if ENABLE_HUSH_TRAP
6256 if (G_traps[sig] && !G_traps[sig][0])
6257 /* trap is '', has to remain SIG_IGN */
6260 G_traps[sig] = NULL;
6263 /* We are here only if no trap or trap was not '' */
6264 install_sighandler(sig, SIG_DFL);
6270 void re_execute_shell(char ***to_free, const char *s,
6271 char *g_argv0, char **g_argv,
6272 char **builtin_argv) NORETURN;
6274 static void reset_traps_to_defaults(void)
6276 /* This function is always called in a child shell
6277 * after fork (not vfork, NOMMU doesn't use this function).
6279 IF_HUSH_TRAP(unsigned sig;)
6282 /* Child shells are not interactive.
6283 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6284 * Testcase: (while :; do :; done) + ^Z should background.
6285 * Same goes for SIGTERM, SIGHUP, SIGINT.
6287 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6288 if (!G_traps && !mask)
6289 return; /* already no traps and no special sigs */
6291 /* Switch off special sigs */
6292 switch_off_special_sigs(mask);
6293 # if ENABLE_HUSH_JOB
6294 G_fatal_sig_mask = 0;
6296 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6297 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6298 * remain set in G.special_sig_mask */
6300 # if ENABLE_HUSH_TRAP
6304 /* Reset all sigs to default except ones with empty traps */
6305 for (sig = 0; sig < NSIG; sig++) {
6307 continue; /* no trap: nothing to do */
6308 if (!G_traps[sig][0])
6309 continue; /* empty trap: has to remain SIG_IGN */
6310 /* sig has non-empty trap, reset it: */
6312 G_traps[sig] = NULL;
6313 /* There is no signal for trap 0 (EXIT) */
6316 install_sighandler(sig, pick_sighandler(sig));
6323 static void re_execute_shell(char ***to_free, const char *s,
6324 char *g_argv0, char **g_argv,
6325 char **builtin_argv) NORETURN;
6326 static void re_execute_shell(char ***to_free, const char *s,
6327 char *g_argv0, char **g_argv,
6328 char **builtin_argv)
6330 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6331 /* delims + 2 * (number of bytes in printed hex numbers) */
6332 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6333 char *heredoc_argv[4];
6334 struct variable *cur;
6335 # if ENABLE_HUSH_FUNCTIONS
6336 struct function *funcp;
6340 unsigned long long empty_trap_mask;
6342 if (!g_argv0) { /* heredoc */
6343 argv = heredoc_argv;
6344 argv[0] = (char *) G.argv0_for_re_execing;
6345 argv[1] = (char *) "-<";
6346 argv[2] = (char *) s;
6348 pp = &argv[3]; /* used as pointer to empty environment */
6354 if (pp) while (*pp++)
6357 empty_trap_mask = 0;
6360 for (sig = 1; sig < NSIG; sig++) {
6361 if (G_traps[sig] && !G_traps[sig][0])
6362 empty_trap_mask |= 1LL << sig;
6366 sprintf(param_buf, NOMMU_HACK_FMT
6367 , (unsigned) G.root_pid
6368 , (unsigned) G.root_ppid
6369 , (unsigned) G.last_bg_pid
6370 , (unsigned) G.last_exitcode
6373 IF_HUSH_LOOPS(, G.depth_of_loop)
6375 # undef NOMMU_HACK_FMT
6376 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6377 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6380 for (cur = G.top_var; cur; cur = cur->next) {
6381 if (!cur->flg_export || cur->flg_read_only)
6384 # if ENABLE_HUSH_FUNCTIONS
6385 for (funcp = G.top_func; funcp; funcp = funcp->next)
6391 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6392 *pp++ = (char *) G.argv0_for_re_execing;
6394 for (cur = G.top_var; cur; cur = cur->next) {
6395 if (strcmp(cur->varstr, hush_version_str) == 0)
6397 if (cur->flg_read_only) {
6398 *pp++ = (char *) "-R";
6399 *pp++ = cur->varstr;
6400 } else if (!cur->flg_export) {
6401 *pp++ = (char *) "-V";
6402 *pp++ = cur->varstr;
6405 # if ENABLE_HUSH_FUNCTIONS
6406 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6407 *pp++ = (char *) "-F";
6408 *pp++ = funcp->name;
6409 *pp++ = funcp->body_as_string;
6412 /* We can pass activated traps here. Say, -Tnn:trap_string
6414 * However, POSIX says that subshells reset signals with traps
6416 * I tested bash-3.2 and it not only does that with true subshells
6417 * of the form ( list ), but with any forked children shells.
6418 * I set trap "echo W" WINCH; and then tried:
6420 * { echo 1; sleep 20; echo 2; } &
6421 * while true; do echo 1; sleep 20; echo 2; break; done &
6422 * true | { echo 1; sleep 20; echo 2; } | cat
6424 * In all these cases sending SIGWINCH to the child shell
6425 * did not run the trap. If I add trap "echo V" WINCH;
6426 * _inside_ group (just before echo 1), it works.
6428 * I conclude it means we don't need to pass active traps here.
6430 *pp++ = (char *) "-c";
6433 while (*++builtin_argv)
6434 *pp++ = *builtin_argv;
6435 *pp++ = (char *) "";
6440 /* *pp = NULL; - is already there */
6444 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6445 /* Don't propagate SIG_IGN to the child */
6446 if (SPECIAL_JOBSTOP_SIGS != 0)
6447 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6448 execve(bb_busybox_exec_path, argv, pp);
6449 /* Fallback. Useful for init=/bin/hush usage etc */
6450 if (argv[0][0] == '/')
6451 execve(argv[0], argv, pp);
6452 xfunc_error_retval = 127;
6453 bb_error_msg_and_die("can't re-execute the shell");
6455 #endif /* !BB_MMU */
6458 static int run_and_free_list(struct pipe *pi);
6460 /* Executing from string: eval, sh -c '...'
6461 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6462 * end_trigger controls how often we stop parsing
6463 * NUL: parse all, execute, return
6464 * ';': parse till ';' or newline, execute, repeat till EOF
6466 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6468 /* Why we need empty flag?
6469 * An obscure corner case "false; ``; echo $?":
6470 * empty command in `` should still set $? to 0.
6471 * But we can't just set $? to 0 at the start,
6472 * this breaks "false; echo `echo $?`" case.
6476 struct pipe *pipe_list;
6478 #if ENABLE_HUSH_INTERACTIVE
6479 if (end_trigger == ';')
6480 inp->promptmode = 0; /* PS1 */
6482 pipe_list = parse_stream(NULL, inp, end_trigger);
6483 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6484 /* If we are in "big" script
6485 * (not in `cmd` or something similar)...
6487 if (pipe_list == ERR_PTR && end_trigger == ';') {
6488 /* Discard cached input (rest of line) */
6489 int ch = inp->last_char;
6490 while (ch != EOF && ch != '\n') {
6491 //bb_error_msg("Discarded:'%c'", ch);
6496 /* This stream isn't empty */
6500 if (!pipe_list && empty)
6501 G.last_exitcode = 0;
6504 debug_print_tree(pipe_list, 0);
6505 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6506 run_and_free_list(pipe_list);
6508 if (G_flag_return_in_progress == 1)
6513 static void parse_and_run_string(const char *s)
6515 struct in_str input;
6516 setup_string_in_str(&input, s);
6517 parse_and_run_stream(&input, '\0');
6520 static void parse_and_run_file(FILE *f)
6522 struct in_str input;
6523 setup_file_in_str(&input, f);
6524 parse_and_run_stream(&input, ';');
6527 #if ENABLE_HUSH_TICK
6528 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6533 char **to_free = NULL;
6537 pid = BB_MMU ? xfork() : xvfork();
6538 if (pid == 0) { /* child */
6539 disable_restore_tty_pgrp_on_exit();
6540 /* Process substitution is not considered to be usual
6541 * 'command execution'.
6542 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6549 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6550 close(channel[0]); /* NB: close _first_, then move fd! */
6551 xmove_fd(channel[1], 1);
6552 /* Prevent it from trying to handle ctrl-z etc */
6553 IF_HUSH_JOB(G.run_list_level = 1;)
6554 # if ENABLE_HUSH_TRAP
6555 /* Awful hack for `trap` or $(trap).
6557 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6558 * contains an example where "trap" is executed in a subshell:
6560 * save_traps=$(trap)
6562 * eval "$save_traps"
6564 * Standard does not say that "trap" in subshell shall print
6565 * parent shell's traps. It only says that its output
6566 * must have suitable form, but then, in the above example
6567 * (which is not supposed to be normative), it implies that.
6569 * bash (and probably other shell) does implement it
6570 * (traps are reset to defaults, but "trap" still shows them),
6571 * but as a result, "trap" logic is hopelessly messed up:
6574 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6575 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6576 * # true | trap <--- trap is in subshell - no output (ditto)
6577 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6578 * trap -- 'echo Ho' SIGWINCH
6579 * # echo `(trap)` <--- in subshell in subshell - output
6580 * trap -- 'echo Ho' SIGWINCH
6581 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6582 * trap -- 'echo Ho' SIGWINCH
6584 * The rules when to forget and when to not forget traps
6585 * get really complex and nonsensical.
6587 * Our solution: ONLY bare $(trap) or `trap` is special.
6589 s = skip_whitespace(s);
6590 if (is_prefixed_with(s, "trap")
6591 && skip_whitespace(s + 4)[0] == '\0'
6593 static const char *const argv[] = { NULL, NULL };
6594 builtin_trap((char**)argv);
6595 fflush_all(); /* important */
6600 reset_traps_to_defaults();
6601 parse_and_run_string(s);
6602 _exit(G.last_exitcode);
6604 /* We re-execute after vfork on NOMMU. This makes this script safe:
6605 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6606 * huge=`cat BIG` # was blocking here forever
6609 re_execute_shell(&to_free,
6619 # if ENABLE_HUSH_FAST
6621 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6622 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6623 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6625 enable_restore_tty_pgrp_on_exit();
6630 return remember_FILE(xfdopen_for_read(channel[0]));
6633 /* Return code is exit status of the process that is run. */
6634 static int process_command_subs(o_string *dest, const char *s)
6637 struct in_str pipe_str;
6639 int status, ch, eol_cnt;
6641 fp = generate_stream_from_string(s, &pid);
6643 /* Now send results of command back into original context */
6644 setup_file_in_str(&pipe_str, fp);
6646 while ((ch = i_getch(&pipe_str)) != EOF) {
6652 o_addchr(dest, '\n');
6655 o_addQchr(dest, ch);
6658 debug_printf("done reading from `cmd` pipe, closing it\n");
6659 fclose_and_forget(fp);
6660 /* We need to extract exitcode. Test case
6661 * "true; echo `sleep 1; false` $?"
6663 safe_waitpid(pid, &status, 0);
6664 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6665 return WEXITSTATUS(status);
6667 #endif /* ENABLE_HUSH_TICK */
6670 static void setup_heredoc(struct redir_struct *redir)
6672 struct fd_pair pair;
6675 /* the _body_ of heredoc (misleading field name) */
6676 const char *heredoc = redir->rd_filename;
6683 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6684 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6688 len = strlen(heredoc);
6690 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6692 xmove_fd(pair.rd, redir->rd_fd);
6694 /* Try writing without forking. Newer kernels have
6695 * dynamically growing pipes. Must use non-blocking write! */
6698 written = write(pair.wr, heredoc, len);
6709 ndelay_off(pair.wr);
6711 /* Okay, pipe buffer was not big enough */
6712 /* Note: we must not create a stray child (bastard? :)
6713 * for the unsuspecting parent process. Child creates a grandchild
6714 * and exits before parent execs the process which consumes heredoc
6715 * (that exec happens after we return from this function) */
6722 disable_restore_tty_pgrp_on_exit();
6723 pid = BB_MMU ? xfork() : xvfork();
6727 close(redir->rd_fd); /* read side of the pipe */
6729 full_write(pair.wr, heredoc, len); /* may loop or block */
6732 /* Delegate blocking writes to another process */
6733 xmove_fd(pair.wr, STDOUT_FILENO);
6734 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6738 #if ENABLE_HUSH_FAST
6740 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6742 enable_restore_tty_pgrp_on_exit();
6748 wait(NULL); /* wait till child has died */
6754 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6755 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6758 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6760 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6761 sq[i].orig_fd = orig;
6762 sq[i].moved_to = moved;
6763 sq[i+1].orig_fd = -1; /* end marker */
6767 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6773 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6774 /* If we collide with an already moved fd... */
6775 if (fd == sq[i].moved_to) {
6776 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6777 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6778 if (sq[i].moved_to < 0) /* what? */
6782 if (fd == sq[i].orig_fd) {
6783 /* Example: echo Hello >/dev/null 1>&2 */
6784 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6789 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6790 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6791 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6792 if (moved_to < 0 && errno != EBADF)
6794 return append_squirrel(sq, i, fd, moved_to);
6797 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6802 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6803 /* If we collide with an already moved fd... */
6804 if (fd == sq[i].orig_fd) {
6806 * "echo 3>FILE 3>&- 3>FILE"
6807 * "echo 3>&- 3>FILE"
6808 * No need for last redirect to insert
6809 * another "need to close 3" indicator.
6811 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6816 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6817 return append_squirrel(sq, i, fd, -1);
6820 /* fd: redirect wants this fd to be used (e.g. 3>file).
6821 * Move all conflicting internally used fds,
6822 * and remember them so that we can restore them later.
6824 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6826 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6829 #if ENABLE_HUSH_INTERACTIVE
6830 if (fd == G.interactive_fd) {
6831 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6832 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6833 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6834 return 1; /* "we closed fd" */
6837 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6838 * (1) Redirect in a forked child. No need to save FILEs' fds,
6839 * we aren't going to use them anymore, ok to trash.
6840 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6841 * but how are we doing to restore them?
6842 * "fileno(fd) = new_fd" can't be done.
6847 /* If this one of script's fds? */
6848 if (save_FILEs_on_redirect(fd, avoid_fd))
6849 return 1; /* yes. "we closed fd" */
6851 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6852 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6853 return 0; /* "we did not close fd" */
6856 static void restore_redirects(struct squirrel *sq)
6860 for (i = 0; sq[i].orig_fd >= 0; i++) {
6861 if (sq[i].moved_to >= 0) {
6862 /* We simply die on error */
6863 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6864 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6866 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6867 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6868 close(sq[i].orig_fd);
6874 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6876 restore_redirected_FILEs();
6879 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6880 static void close_saved_fds_and_FILE_fds(void)
6882 if (G_interactive_fd)
6883 close(G_interactive_fd);
6884 close_all_FILE_list();
6888 static int internally_opened_fd(int fd, struct squirrel *sq)
6892 #if ENABLE_HUSH_INTERACTIVE
6893 if (fd == G.interactive_fd)
6896 /* If this one of script's fds? */
6897 if (fd_in_FILEs(fd))
6900 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6901 if (fd == sq[i].moved_to)
6907 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6908 * and stderr if they are redirected. */
6909 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6911 struct redir_struct *redir;
6913 for (redir = prog->redirects; redir; redir = redir->next) {
6917 if (redir->rd_type == REDIRECT_HEREDOC2) {
6918 /* "rd_fd<<HERE" case */
6919 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6920 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6922 debug_printf_parse("set heredoc '%s'\n",
6923 redir->rd_filename);
6924 setup_heredoc(redir);
6928 if (redir->rd_dup == REDIRFD_TO_FILE) {
6929 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6933 if (redir->rd_filename == NULL) {
6936 * "cmd >" (no filename)
6937 * "cmd > <file" (2nd redirect starts too early)
6939 syntax_error("invalid redirect");
6942 mode = redir_table[redir->rd_type].mode;
6943 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6944 newfd = open_or_warn(p, mode);
6947 /* Error message from open_or_warn can be lost
6948 * if stderr has been redirected, but bash
6949 * and ash both lose it as well
6950 * (though zsh doesn't!)
6954 if (newfd == redir->rd_fd && sqp) {
6955 /* open() gave us precisely the fd we wanted.
6956 * This means that this fd was not busy
6957 * (not opened to anywhere).
6958 * Remember to close it on restore:
6960 *sqp = add_squirrel_closed(*sqp, newfd);
6961 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6964 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6965 newfd = redir->rd_dup;
6968 if (newfd == redir->rd_fd)
6971 /* if "N>FILE": move newfd to redir->rd_fd */
6972 /* if "N>&M": dup newfd to redir->rd_fd */
6973 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6975 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6976 if (newfd == REDIRFD_CLOSE) {
6977 /* "N>&-" means "close me" */
6979 /* ^^^ optimization: saving may already
6980 * have closed it. If not... */
6981 close(redir->rd_fd);
6983 /* Sometimes we do another close on restore, getting EBADF.
6984 * Consider "echo 3>FILE 3>&-"
6985 * first redirect remembers "need to close 3",
6986 * and second redirect closes 3! Restore code then closes 3 again.
6989 /* if newfd is a script fd or saved fd, simulate EBADF */
6990 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6992 //bb_perror_msg_and_die("can't duplicate file descriptor");
6993 newfd = -1; /* same effect as code above */
6995 xdup2(newfd, redir->rd_fd);
6996 if (redir->rd_dup == REDIRFD_TO_FILE)
6997 /* "rd_fd > FILE" */
6999 /* else: "rd_fd > rd_dup" */
7005 static char *find_in_path(const char *arg)
7008 const char *PATH = get_local_var_value("PATH");
7014 const char *end = strchrnul(PATH, ':');
7015 int sz = end - PATH; /* must be int! */
7019 ret = xasprintf("%.*s/%s", sz, PATH, arg);
7021 /* We have xxx::yyyy in $PATH,
7022 * it means "use current dir" */
7025 if (access(ret, F_OK) == 0)
7038 static const struct built_in_command *find_builtin_helper(const char *name,
7039 const struct built_in_command *x,
7040 const struct built_in_command *end)
7043 if (strcmp(name, x->b_cmd) != 0) {
7047 debug_printf_exec("found builtin '%s'\n", name);
7052 static const struct built_in_command *find_builtin1(const char *name)
7054 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7056 static const struct built_in_command *find_builtin(const char *name)
7058 const struct built_in_command *x = find_builtin1(name);
7061 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7064 #if ENABLE_HUSH_FUNCTIONS
7065 static struct function **find_function_slot(const char *name)
7067 struct function **funcpp = &G.top_func;
7069 if (strcmp(name, (*funcpp)->name) == 0) {
7072 funcpp = &(*funcpp)->next;
7077 static const struct function *find_function(const char *name)
7079 const struct function *funcp = *find_function_slot(name);
7081 debug_printf_exec("found function '%s'\n", name);
7085 /* Note: takes ownership on name ptr */
7086 static struct function *new_function(char *name)
7088 struct function **funcpp = find_function_slot(name);
7089 struct function *funcp = *funcpp;
7091 if (funcp != NULL) {
7092 struct command *cmd = funcp->parent_cmd;
7093 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7095 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7097 /* Note: if !funcp->body, do not free body_as_string!
7098 * This is a special case of "-F name body" function:
7099 * body_as_string was not malloced! */
7101 free_pipe_list(funcp->body);
7103 free(funcp->body_as_string);
7107 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7108 cmd->argv[0] = funcp->name;
7109 cmd->group = funcp->body;
7111 cmd->group_as_string = funcp->body_as_string;
7115 debug_printf_exec("remembering new function '%s'\n", name);
7116 funcp = *funcpp = xzalloc(sizeof(*funcp));
7117 /*funcp->next = NULL;*/
7124 # if ENABLE_HUSH_UNSET
7125 static void unset_func(const char *name)
7127 struct function **funcpp = find_function_slot(name);
7128 struct function *funcp = *funcpp;
7130 if (funcp != NULL) {
7131 debug_printf_exec("freeing function '%s'\n", funcp->name);
7132 *funcpp = funcp->next;
7133 /* funcp is unlinked now, deleting it.
7134 * Note: if !funcp->body, the function was created by
7135 * "-F name body", do not free ->body_as_string
7136 * and ->name as they were not malloced. */
7138 free_pipe_list(funcp->body);
7141 free(funcp->body_as_string);
7150 #define exec_function(to_free, funcp, argv) \
7151 exec_function(funcp, argv)
7153 static void exec_function(char ***to_free,
7154 const struct function *funcp,
7155 char **argv) NORETURN;
7156 static void exec_function(char ***to_free,
7157 const struct function *funcp,
7163 argv[0] = G.global_argv[0];
7164 G.global_argv = argv;
7165 G.global_argc = n = 1 + string_array_len(argv + 1);
7167 // Example when we are here: "cmd | func"
7168 // func will run with saved-redirect fds open.
7169 // $ f() { echo /proc/self/fd/*; }
7171 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7172 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7175 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7176 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7177 // They are CLOEXEC so external programs won't see them, but
7178 // for "more correctness" we might want to close those extra fds here:
7179 //? close_saved_fds_and_FILE_fds();
7181 /* "we are in function, ok to use return" */
7182 G_flag_return_in_progress = -1;
7183 IF_HUSH_LOCAL(G.func_nest_level++;)
7185 /* On MMU, funcp->body is always non-NULL */
7186 n = run_list(funcp->body);
7190 //? close_saved_fds_and_FILE_fds();
7192 //TODO: check whether "true | func_with_return" works
7194 re_execute_shell(to_free,
7195 funcp->body_as_string,
7202 static int run_function(const struct function *funcp, char **argv)
7208 save_and_replace_G_args(&sv, argv);
7210 /* "we are in function, ok to use return" */
7211 sv_flg = G_flag_return_in_progress;
7212 G_flag_return_in_progress = -1;
7213 IF_HUSH_LOCAL(G.func_nest_level++;)
7215 /* On MMU, funcp->body is always non-NULL */
7218 /* Function defined by -F */
7219 parse_and_run_string(funcp->body_as_string);
7220 rc = G.last_exitcode;
7224 rc = run_list(funcp->body);
7227 # if ENABLE_HUSH_LOCAL
7229 struct variable *var;
7230 struct variable **var_pp;
7232 var_pp = &G.top_var;
7233 while ((var = *var_pp) != NULL) {
7234 if (var->func_nest_level < G.func_nest_level) {
7235 var_pp = &var->next;
7239 if (var->flg_export)
7240 bb_unsetenv(var->varstr);
7241 /* Remove from global list */
7242 *var_pp = var->next;
7248 G.func_nest_level--;
7251 G_flag_return_in_progress = sv_flg;
7253 restore_G_args(&sv, argv);
7257 #endif /* ENABLE_HUSH_FUNCTIONS */
7261 #define exec_builtin(to_free, x, argv) \
7262 exec_builtin(x, argv)
7264 #define exec_builtin(to_free, x, argv) \
7265 exec_builtin(to_free, argv)
7267 static void exec_builtin(char ***to_free,
7268 const struct built_in_command *x,
7269 char **argv) NORETURN;
7270 static void exec_builtin(char ***to_free,
7271 const struct built_in_command *x,
7277 //? close_saved_fds_and_FILE_fds();
7278 rcode = x->b_function(argv);
7283 /* On NOMMU, we must never block!
7284 * Example: { sleep 99 | read line; } & echo Ok
7286 re_execute_shell(to_free,
7295 static void execvp_or_die(char **argv) NORETURN;
7296 static void execvp_or_die(char **argv)
7299 debug_printf_exec("execing '%s'\n", argv[0]);
7300 /* Don't propagate SIG_IGN to the child */
7301 if (SPECIAL_JOBSTOP_SIGS != 0)
7302 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7303 execvp(argv[0], argv);
7305 if (errno == EACCES) e = 126;
7306 if (errno == ENOENT) e = 127;
7307 bb_perror_msg("can't execute '%s'", argv[0]);
7311 #if ENABLE_HUSH_MODE_X
7312 static void dump_cmd_in_x_mode(char **argv)
7314 if (G_x_mode && argv) {
7315 /* We want to output the line in one write op */
7323 len += strlen(argv[n++]) + 1;
7329 p += sprintf(p, " %s", argv[n++]);
7337 # define dump_cmd_in_x_mode(argv) ((void)0)
7341 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7342 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7343 #define pseudo_exec(nommu_save, command, argv_expanded) \
7344 pseudo_exec(command, argv_expanded)
7347 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7349 * Don't exit() here. If you don't exec, use _exit instead.
7350 * The at_exit handlers apparently confuse the calling process,
7351 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7353 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7354 char **argv, int assignment_cnt,
7355 char **argv_expanded) NORETURN;
7356 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7357 char **argv, int assignment_cnt,
7358 char **argv_expanded)
7362 new_env = expand_assignments(argv, assignment_cnt);
7363 dump_cmd_in_x_mode(new_env);
7365 if (!argv[assignment_cnt]) {
7366 /* Case when we are here: ... | var=val | ...
7367 * (note that we do not exit early, i.e., do not optimize out
7368 * expand_assignments(): think about ... | var=`sleep 1` | ...
7370 free_strings(new_env);
7371 _exit(EXIT_SUCCESS);
7375 set_vars_and_save_old(new_env);
7376 free(new_env); /* optional */
7377 /* we can also destroy set_vars_and_save_old's return value,
7380 nommu_save->new_env = new_env;
7381 nommu_save->old_vars = set_vars_and_save_old(new_env);
7384 if (argv_expanded) {
7385 argv = argv_expanded;
7387 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7389 nommu_save->argv = argv;
7392 dump_cmd_in_x_mode(argv);
7394 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7395 if (strchr(argv[0], '/') != NULL)
7399 #if ENABLE_HUSH_FUNCTIONS
7400 /* Check if the command matches any functions (this goes before bltins) */
7402 const struct function *funcp = find_function(argv[0]);
7404 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7409 /* Check if the command matches any of the builtins.
7410 * Depending on context, this might be redundant. But it's
7411 * easier to waste a few CPU cycles than it is to figure out
7412 * if this is one of those cases.
7415 const struct built_in_command *x;
7417 #if ENABLE_HUSH_COMMAND
7418 /* This loop effectively makes "command BAR" run BAR without
7419 * looking it up among functions.
7421 while (strcmp(argv[0], "command") == 0 && argv[1])
7423 //TODO: implement -Vvp and "disable dying if BAR is a builtin" behavior
7425 /* On NOMMU, it is more expensive to re-execute shell
7426 * just in order to run echo or test builtin.
7427 * It's better to skip it here and run corresponding
7428 * non-builtin later. */
7429 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7431 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7435 #if ENABLE_FEATURE_SH_STANDALONE
7436 /* Check if the command matches any busybox applets */
7438 int a = find_applet_by_name(argv[0]);
7440 # if BB_MMU /* see above why on NOMMU it is not allowed */
7441 if (APPLET_IS_NOEXEC(a)) {
7442 /* Do not leak open fds from opened script files etc.
7443 * Testcase: interactive "ls -l /proc/self/fd"
7444 * should not show tty fd open.
7446 close_saved_fds_and_FILE_fds();
7447 //FIXME: should also close saved redir fds
7448 /* Without this, "rm -i FILE" can't be ^C'ed: */
7449 switch_off_special_sigs(G.special_sig_mask);
7450 debug_printf_exec("running applet '%s'\n", argv[0]);
7451 run_noexec_applet_and_exit(a, argv[0], argv);
7454 /* Re-exec ourselves */
7455 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7456 /* Don't propagate SIG_IGN to the child */
7457 if (SPECIAL_JOBSTOP_SIGS != 0)
7458 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7459 execv(bb_busybox_exec_path, argv);
7460 /* If they called chroot or otherwise made the binary no longer
7461 * executable, fall through */
7466 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7469 execvp_or_die(argv);
7472 /* Called after [v]fork() in run_pipe
7474 static void pseudo_exec(nommu_save_t *nommu_save,
7475 struct command *command,
7476 char **argv_expanded) NORETURN;
7477 static void pseudo_exec(nommu_save_t *nommu_save,
7478 struct command *command,
7479 char **argv_expanded)
7481 if (command->argv) {
7482 pseudo_exec_argv(nommu_save, command->argv,
7483 command->assignment_cnt, argv_expanded);
7486 if (command->group) {
7487 /* Cases when we are here:
7490 * ... | ( list ) | ...
7491 * ... | { list } | ...
7495 debug_printf_exec("pseudo_exec: run_list\n");
7496 reset_traps_to_defaults();
7497 rcode = run_list(command->group);
7498 /* OK to leak memory by not calling free_pipe_list,
7499 * since this process is about to exit */
7502 re_execute_shell(&nommu_save->argv_from_re_execing,
7503 command->group_as_string,
7510 /* Case when we are here: ... | >file */
7511 debug_printf_exec("pseudo_exec'ed null command\n");
7512 _exit(EXIT_SUCCESS);
7516 static const char *get_cmdtext(struct pipe *pi)
7522 /* This is subtle. ->cmdtext is created only on first backgrounding.
7523 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7524 * On subsequent bg argv is trashed, but we won't use it */
7528 argv = pi->cmds[0].argv;
7530 pi->cmdtext = xzalloc(1);
7535 len += strlen(*argv) + 1;
7539 argv = pi->cmds[0].argv;
7541 p = stpcpy(p, *argv);
7548 static void remove_job_from_table(struct pipe *pi)
7550 struct pipe *prev_pipe;
7552 if (pi == G.job_list) {
7553 G.job_list = pi->next;
7555 prev_pipe = G.job_list;
7556 while (prev_pipe->next != pi)
7557 prev_pipe = prev_pipe->next;
7558 prev_pipe->next = pi->next;
7562 G.last_jobid = G.job_list->jobid;
7565 static void delete_finished_job(struct pipe *pi)
7567 remove_job_from_table(pi);
7571 static void clean_up_last_dead_job(void)
7573 if (G.job_list && !G.job_list->alive_cmds)
7574 delete_finished_job(G.job_list);
7577 static void insert_job_into_table(struct pipe *pi)
7579 struct pipe *job, **jobp;
7582 clean_up_last_dead_job();
7584 /* Find the end of the list, and find next job ID to use */
7587 while ((job = *jobp) != NULL) {
7594 /* Create a new job struct at the end */
7595 job = *jobp = xmemdup(pi, sizeof(*pi));
7597 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7598 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7599 for (i = 0; i < pi->num_cmds; i++) {
7600 job->cmds[i].pid = pi->cmds[i].pid;
7601 /* all other fields are not used and stay zero */
7603 job->cmdtext = xstrdup(get_cmdtext(pi));
7605 if (G_interactive_fd)
7606 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7607 G.last_jobid = job->jobid;
7611 static int job_exited_or_stopped(struct pipe *pi)
7615 if (pi->alive_cmds != pi->stopped_cmds)
7618 /* All processes in fg pipe have exited or stopped */
7622 rcode = pi->cmds[i].cmd_exitcode;
7623 /* usually last process gives overall exitstatus,
7624 * but with "set -o pipefail", last *failed* process does */
7625 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7628 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7632 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7639 dead = WIFEXITED(status) || WIFSIGNALED(status);
7642 if (WIFSTOPPED(status))
7643 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7644 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7645 if (WIFSIGNALED(status))
7646 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7647 childpid, WTERMSIG(status), WEXITSTATUS(status));
7648 if (WIFEXITED(status))
7649 debug_printf_jobs("pid %d exited, exitcode %d\n",
7650 childpid, WEXITSTATUS(status));
7652 /* Were we asked to wait for a fg pipe? */
7654 i = fg_pipe->num_cmds;
7659 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7660 if (fg_pipe->cmds[i].pid != childpid)
7664 fg_pipe->cmds[i].pid = 0;
7665 fg_pipe->alive_cmds--;
7666 ex = WEXITSTATUS(status);
7667 /* bash prints killer signal's name for *last*
7668 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7669 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7671 if (WIFSIGNALED(status)) {
7672 int sig = WTERMSIG(status);
7673 if (i == fg_pipe->num_cmds-1)
7674 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7675 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7676 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7677 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7678 * Maybe we need to use sig | 128? */
7681 fg_pipe->cmds[i].cmd_exitcode = ex;
7683 fg_pipe->stopped_cmds++;
7685 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7686 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7687 rcode = job_exited_or_stopped(fg_pipe);
7689 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7690 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7691 * and "killall -STOP cat" */
7692 if (G_interactive_fd) {
7694 if (fg_pipe->alive_cmds != 0)
7695 insert_job_into_table(fg_pipe);
7699 if (fg_pipe->alive_cmds == 0)
7702 /* There are still running processes in the fg_pipe */
7705 /* It wasn't in fg_pipe, look for process in bg pipes */
7709 /* We were asked to wait for bg or orphaned children */
7710 /* No need to remember exitcode in this case */
7711 for (pi = G.job_list; pi; pi = pi->next) {
7712 for (i = 0; i < pi->num_cmds; i++) {
7713 if (pi->cmds[i].pid == childpid)
7714 goto found_pi_and_prognum;
7717 /* Happens when shell is used as init process (init=/bin/sh) */
7718 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7719 return -1; /* this wasn't a process from fg_pipe */
7721 found_pi_and_prognum:
7724 int rcode = WEXITSTATUS(status);
7725 if (WIFSIGNALED(status))
7726 rcode = 128 + WTERMSIG(status);
7727 pi->cmds[i].cmd_exitcode = rcode;
7728 if (G.last_bg_pid == pi->cmds[i].pid)
7729 G.last_bg_pid_exitcode = rcode;
7730 pi->cmds[i].pid = 0;
7732 if (!pi->alive_cmds) {
7733 if (G_interactive_fd) {
7734 printf(JOB_STATUS_FORMAT, pi->jobid,
7735 "Done", pi->cmdtext);
7736 delete_finished_job(pi);
7739 * bash deletes finished jobs from job table only in interactive mode,
7740 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7741 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7742 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7743 * We only retain one "dead" job, if it's the single job on the list.
7744 * This covers most of real-world scenarios where this is useful.
7746 if (pi != G.job_list)
7747 delete_finished_job(pi);
7755 return -1; /* this wasn't a process from fg_pipe */
7758 /* Check to see if any processes have exited -- if they have,
7759 * figure out why and see if a job has completed.
7761 * If non-NULL fg_pipe: wait for its completion or stop.
7762 * Return its exitcode or zero if stopped.
7764 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7765 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7766 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7767 * or 0 if no children changed status.
7769 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7770 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7771 * or 0 if no children changed status.
7773 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7779 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7781 attributes = WUNTRACED;
7782 if (fg_pipe == NULL)
7783 attributes |= WNOHANG;
7786 #if ENABLE_HUSH_FAST
7787 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7788 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7789 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7790 /* There was neither fork nor SIGCHLD since last waitpid */
7791 /* Avoid doing waitpid syscall if possible */
7792 if (!G.we_have_children) {
7796 if (fg_pipe == NULL) { /* is WNOHANG set? */
7797 /* We have children, but they did not exit
7798 * or stop yet (we saw no SIGCHLD) */
7801 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7805 /* Do we do this right?
7806 * bash-3.00# sleep 20 | false
7808 * [3]+ Stopped sleep 20 | false
7809 * bash-3.00# echo $?
7810 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7811 * [hush 1.14.0: yes we do it right]
7815 #if ENABLE_HUSH_FAST
7817 i = G.count_SIGCHLD;
7819 childpid = waitpid(-1, &status, attributes);
7820 if (childpid <= 0) {
7821 if (childpid && errno != ECHILD)
7822 bb_perror_msg("waitpid");
7823 #if ENABLE_HUSH_FAST
7824 else { /* Until next SIGCHLD, waitpid's are useless */
7825 G.we_have_children = (childpid == 0);
7826 G.handled_SIGCHLD = i;
7827 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7830 /* ECHILD (no children), or 0 (no change in children status) */
7834 rcode = process_wait_result(fg_pipe, childpid, status);
7836 /* fg_pipe exited or stopped */
7839 if (childpid == waitfor_pid) {
7840 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7841 rcode = WEXITSTATUS(status);
7842 if (WIFSIGNALED(status))
7843 rcode = 128 + WTERMSIG(status);
7844 if (WIFSTOPPED(status))
7845 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7846 rcode = 128 + WSTOPSIG(status);
7848 break; /* "wait PID" called us, give it exitcode+1 */
7850 /* This wasn't one of our processes, or */
7851 /* fg_pipe still has running processes, do waitpid again */
7852 } /* while (waitpid succeeds)... */
7858 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7861 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7862 if (G_saved_tty_pgrp) {
7863 /* Job finished, move the shell to the foreground */
7864 p = getpgrp(); /* our process group id */
7865 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7866 tcsetpgrp(G_interactive_fd, p);
7872 /* Start all the jobs, but don't wait for anything to finish.
7875 * Return code is normally -1, when the caller has to wait for children
7876 * to finish to determine the exit status of the pipe. If the pipe
7877 * is a simple builtin command, however, the action is done by the
7878 * time run_pipe returns, and the exit code is provided as the
7881 * Returns -1 only if started some children. IOW: we have to
7882 * mask out retvals of builtins etc with 0xff!
7884 * The only case when we do not need to [v]fork is when the pipe
7885 * is single, non-backgrounded, non-subshell command. Examples:
7886 * cmd ; ... { list } ; ...
7887 * cmd && ... { list } && ...
7888 * cmd || ... { list } || ...
7889 * If it is, then we can run cmd as a builtin, NOFORK,
7890 * or (if SH_STANDALONE) an applet, and we can run the { list }
7891 * with run_list. If it isn't one of these, we fork and exec cmd.
7893 * Cases when we must fork:
7894 * non-single: cmd | cmd
7895 * backgrounded: cmd & { list } &
7896 * subshell: ( list ) [&]
7898 #if !ENABLE_HUSH_MODE_X
7899 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7900 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7902 static int redirect_and_varexp_helper(char ***new_env_p,
7903 struct variable **old_vars_p,
7904 struct command *command,
7905 struct squirrel **sqp,
7906 char **argv_expanded)
7908 /* setup_redirects acts on file descriptors, not FILEs.
7909 * This is perfect for work that comes after exec().
7910 * Is it really safe for inline use? Experimentally,
7911 * things seem to work. */
7912 int rcode = setup_redirects(command, sqp);
7914 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7915 *new_env_p = new_env;
7916 dump_cmd_in_x_mode(new_env);
7917 dump_cmd_in_x_mode(argv_expanded);
7919 *old_vars_p = set_vars_and_save_old(new_env);
7923 static NOINLINE int run_pipe(struct pipe *pi)
7925 static const char *const null_ptr = NULL;
7929 struct command *command;
7930 char **argv_expanded;
7932 struct squirrel *squirrel = NULL;
7935 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7938 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7939 * Result should be 3 lines: q w e, qwe, q w e
7941 G.ifs = get_local_var_value("IFS");
7945 IF_HUSH_JOB(pi->pgrp = -1;)
7946 pi->stopped_cmds = 0;
7947 command = &pi->cmds[0];
7948 argv_expanded = NULL;
7950 if (pi->num_cmds != 1
7951 || pi->followup == PIPE_BG
7952 || command->cmd_type == CMD_SUBSHELL
7959 debug_printf_exec(": group:%p argv:'%s'\n",
7960 command->group, command->argv ? command->argv[0] : "NONE");
7962 if (command->group) {
7963 #if ENABLE_HUSH_FUNCTIONS
7964 if (command->cmd_type == CMD_FUNCDEF) {
7965 /* "executing" func () { list } */
7966 struct function *funcp;
7968 funcp = new_function(command->argv[0]);
7969 /* funcp->name is already set to argv[0] */
7970 funcp->body = command->group;
7972 funcp->body_as_string = command->group_as_string;
7973 command->group_as_string = NULL;
7975 command->group = NULL;
7976 command->argv[0] = NULL;
7977 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7978 funcp->parent_cmd = command;
7979 command->child_func = funcp;
7981 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7983 return EXIT_SUCCESS;
7987 debug_printf("non-subshell group\n");
7988 rcode = 1; /* exitcode if redir failed */
7989 if (setup_redirects(command, &squirrel) == 0) {
7990 debug_printf_exec(": run_list\n");
7991 rcode = run_list(command->group) & 0xff;
7993 restore_redirects(squirrel);
7994 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7996 debug_printf_exec("run_pipe: return %d\n", rcode);
8000 argv = command->argv ? command->argv : (char **) &null_ptr;
8002 const struct built_in_command *x;
8003 #if ENABLE_HUSH_FUNCTIONS
8004 const struct function *funcp;
8008 char **new_env = NULL;
8009 struct variable *old_vars = NULL;
8011 if (argv[command->assignment_cnt] == NULL) {
8012 /* Assignments, but no command */
8013 /* Ensure redirects take effect (that is, create files).
8014 * Try "a=t >file" */
8015 #if 0 /* A few cases in testsuite fail with this code. FIXME */
8016 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
8017 /* Set shell variables */
8021 if (set_local_var(*argv, /*flag:*/ 0)) {
8022 /* assignment to readonly var / putenv error? */
8028 /* Redirect error sets $? to 1. Otherwise,
8029 * if evaluating assignment value set $?, retain it.
8030 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8032 rcode = G.last_exitcode;
8033 /* Exit, _skipping_ variable restoring code: */
8034 goto clean_up_and_ret0;
8036 #else /* Older, bigger, but more correct code */
8038 rcode = setup_redirects(command, &squirrel);
8039 restore_redirects(squirrel);
8040 /* Set shell variables */
8042 bb_putchar_stderr('+');
8044 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8046 fprintf(stderr, " %s", p);
8047 debug_printf_exec("set shell var:'%s'->'%s'\n",
8049 if (set_local_var(p, /*flag:*/ 0)) {
8050 /* assignment to readonly var / putenv error? */
8056 bb_putchar_stderr('\n');
8057 /* Redirect error sets $? to 1. Otherwise,
8058 * if evaluating assignment value set $?, retain it.
8059 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8061 rcode = G.last_exitcode;
8062 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8064 debug_printf_exec("run_pipe: return %d\n", rcode);
8069 /* Expand the rest into (possibly) many strings each */
8071 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8072 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8076 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8079 /* if someone gives us an empty string: `cmd with empty output` */
8080 if (!argv_expanded[0]) {
8081 free(argv_expanded);
8083 return G.last_exitcode;
8086 #if ENABLE_HUSH_FUNCTIONS
8087 /* Check if argv[0] matches any functions (this goes before bltins) */
8088 funcp = find_function(argv_expanded[0]);
8092 x = find_builtin(argv_expanded[0]);
8095 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8096 debug_printf("exec with redirects only\n");
8097 rcode = setup_redirects(command, NULL);
8098 /* rcode=1 can be if redir file can't be opened */
8099 goto clean_up_and_ret1;
8102 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8105 debug_printf_exec(": builtin '%s' '%s'...\n",
8106 x->b_cmd, argv_expanded[1]);
8108 rcode = x->b_function(argv_expanded) & 0xff;
8111 #if ENABLE_HUSH_FUNCTIONS
8113 # if ENABLE_HUSH_LOCAL
8114 struct variable **sv;
8115 sv = G.shadowed_vars_pp;
8116 G.shadowed_vars_pp = &old_vars;
8118 debug_printf_exec(": function '%s' '%s'...\n",
8119 funcp->name, argv_expanded[1]);
8120 rcode = run_function(funcp, argv_expanded) & 0xff;
8121 # if ENABLE_HUSH_LOCAL
8122 G.shadowed_vars_pp = sv;
8128 unset_vars(new_env);
8130 /* clean_up_and_ret0: */
8131 restore_redirects(squirrel);
8133 * Try "usleep 99999999" + ^C + "echo $?"
8134 * with FEATURE_SH_NOFORK=y.
8137 /* It was builtin or nofork.
8138 * if this would be a real fork/execed program,
8139 * it should have died if a fatal sig was received.
8140 * But OTOH, there was no separate process,
8141 * the sig was sent to _shell_, not to non-existing
8143 * Let's just handle ^C only, this one is obvious:
8144 * we aren't ok with exitcode 0 when ^C was pressed
8145 * during builtin/nofork.
8147 if (sigismember(&G.pending_set, SIGINT))
8148 rcode = 128 + SIGINT;
8151 free(argv_expanded);
8152 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8154 debug_printf_exec("run_pipe return %d\n", rcode);
8158 if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) {
8159 int n = find_applet_by_name(argv_expanded[0]);
8160 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8161 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8163 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8164 argv_expanded[0], argv_expanded[1]);
8166 * Note: signals (^C) can't interrupt here.
8167 * We remember them and they will be acted upon
8168 * after applet returns.
8169 * This makes applets which can run for a long time
8170 * and/or wait for user input ineligible for NOFORK:
8171 * for example, "yes" or "rm" (rm -i waits for input).
8173 rcode = run_nofork_applet(n, argv_expanded);
8175 goto clean_up_and_ret;
8178 /* It is neither builtin nor applet. We must fork. */
8182 /* NB: argv_expanded may already be created, and that
8183 * might include `cmd` runs! Do not rerun it! We *must*
8184 * use argv_expanded if it's non-NULL */
8186 /* Going to fork a child per each pipe member */
8191 while (cmd_no < pi->num_cmds) {
8192 struct fd_pair pipefds;
8194 volatile nommu_save_t nommu_save;
8195 nommu_save.new_env = NULL;
8196 nommu_save.old_vars = NULL;
8197 nommu_save.argv = NULL;
8198 nommu_save.argv_from_re_execing = NULL;
8200 command = &pi->cmds[cmd_no];
8202 if (command->argv) {
8203 debug_printf_exec(": pipe member '%s' '%s'...\n",
8204 command->argv[0], command->argv[1]);
8206 debug_printf_exec(": pipe member with no argv\n");
8209 /* pipes are inserted between pairs of commands */
8212 if (cmd_no < pi->num_cmds)
8213 xpiped_pair(pipefds);
8215 command->pid = BB_MMU ? fork() : vfork();
8216 if (!command->pid) { /* child */
8218 disable_restore_tty_pgrp_on_exit();
8219 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8221 /* Every child adds itself to new process group
8222 * with pgid == pid_of_first_child_in_pipe */
8223 if (G.run_list_level == 1 && G_interactive_fd) {
8226 if (pgrp < 0) /* true for 1st process only */
8228 if (setpgid(0, pgrp) == 0
8229 && pi->followup != PIPE_BG
8230 && G_saved_tty_pgrp /* we have ctty */
8232 /* We do it in *every* child, not just first,
8234 tcsetpgrp(G_interactive_fd, pgrp);
8238 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8239 /* 1st cmd in backgrounded pipe
8240 * should have its stdin /dev/null'ed */
8242 if (open(bb_dev_null, O_RDONLY))
8243 xopen("/", O_RDONLY);
8245 xmove_fd(next_infd, 0);
8247 xmove_fd(pipefds.wr, 1);
8250 /* Like bash, explicit redirects override pipes,
8251 * and the pipe fd (fd#1) is available for dup'ing:
8252 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8253 * of cmd1 goes into pipe.
8255 if (setup_redirects(command, NULL)) {
8256 /* Happens when redir file can't be opened:
8257 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8259 * hush: can't open '/qwe/rty': No such file or directory
8261 * (echo BAR is not executed, it hits _exit(1) below)
8266 /* Stores to nommu_save list of env vars putenv'ed
8267 * (NOMMU, on MMU we don't need that) */
8268 /* cast away volatility... */
8269 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8270 /* pseudo_exec() does not return */
8273 /* parent or error */
8274 #if ENABLE_HUSH_FAST
8276 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8278 enable_restore_tty_pgrp_on_exit();
8280 /* Clean up after vforked child */
8281 free(nommu_save.argv);
8282 free(nommu_save.argv_from_re_execing);
8283 unset_vars(nommu_save.new_env);
8284 add_vars(nommu_save.old_vars);
8286 free(argv_expanded);
8287 argv_expanded = NULL;
8288 if (command->pid < 0) { /* [v]fork failed */
8289 /* Clearly indicate, was it fork or vfork */
8290 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8294 /* Second and next children need to know pid of first one */
8296 pi->pgrp = command->pid;
8302 if (cmd_no < pi->num_cmds)
8304 /* Pass read (output) pipe end to next iteration */
8305 next_infd = pipefds.rd;
8308 if (!pi->alive_cmds) {
8310 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8315 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8319 /* NB: called by pseudo_exec, and therefore must not modify any
8320 * global data until exec/_exit (we can be a child after vfork!) */
8321 static int run_list(struct pipe *pi)
8323 #if ENABLE_HUSH_CASE
8324 char *case_word = NULL;
8326 #if ENABLE_HUSH_LOOPS
8327 struct pipe *loop_top = NULL;
8328 char **for_lcur = NULL;
8329 char **for_list = NULL;
8331 smallint last_followup;
8333 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8334 smalluint cond_code = 0;
8336 enum { cond_code = 0 };
8339 smallint rword; /* RES_foo */
8340 smallint last_rword; /* ditto */
8343 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8346 #if ENABLE_HUSH_LOOPS
8347 /* Check syntax for "for" */
8350 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8351 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8353 /* current word is FOR or IN (BOLD in comments below) */
8354 if (cpipe->next == NULL) {
8355 syntax_error("malformed for");
8357 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8360 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8361 if (cpipe->next->res_word == RES_DO)
8363 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8364 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8365 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8367 syntax_error("malformed for");
8369 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8376 /* Past this point, all code paths should jump to ret: label
8377 * in order to return, no direct "return" statements please.
8378 * This helps to ensure that no memory is leaked. */
8386 last_rword = RES_XXXX;
8388 last_followup = PIPE_SEQ;
8389 rcode = G.last_exitcode;
8391 /* Go through list of pipes, (maybe) executing them. */
8392 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8394 int sv_errexit_depth;
8398 if (G_flag_return_in_progress == 1)
8401 IF_HAS_KEYWORDS(rword = pi->res_word;)
8402 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8403 rword, cond_code, last_rword);
8405 sv_errexit_depth = G.errexit_depth;
8408 rword == RES_IF || rword == RES_ELIF ||
8410 pi->followup != PIPE_SEQ
8414 #if ENABLE_HUSH_LOOPS
8415 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8416 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8418 /* start of a loop: remember where loop starts */
8423 /* Still in the same "if...", "then..." or "do..." branch? */
8424 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8425 if ((rcode == 0 && last_followup == PIPE_OR)
8426 || (rcode != 0 && last_followup == PIPE_AND)
8428 /* It is "<true> || CMD" or "<false> && CMD"
8429 * and we should not execute CMD */
8430 debug_printf_exec("skipped cmd because of || or &&\n");
8431 last_followup = pi->followup;
8432 goto dont_check_jobs_but_continue;
8435 last_followup = pi->followup;
8436 IF_HAS_KEYWORDS(last_rword = rword;)
8439 if (rword == RES_THEN) {
8440 /* if false; then ... fi has exitcode 0! */
8441 G.last_exitcode = rcode = EXIT_SUCCESS;
8442 /* "if <false> THEN cmd": skip cmd */
8446 if (rword == RES_ELSE || rword == RES_ELIF) {
8447 /* "if <true> then ... ELSE/ELIF cmd":
8448 * skip cmd and all following ones */
8453 #if ENABLE_HUSH_LOOPS
8454 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8456 /* first loop through for */
8458 static const char encoded_dollar_at[] ALIGN1 = {
8459 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8460 }; /* encoded representation of "$@" */
8461 static const char *const encoded_dollar_at_argv[] = {
8462 encoded_dollar_at, NULL
8463 }; /* argv list with one element: "$@" */
8466 vals = (char**)encoded_dollar_at_argv;
8467 if (pi->next->res_word == RES_IN) {
8468 /* if no variable values after "in" we skip "for" */
8469 if (!pi->next->cmds[0].argv) {
8470 G.last_exitcode = rcode = EXIT_SUCCESS;
8471 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8474 vals = pi->next->cmds[0].argv;
8475 } /* else: "for var; do..." -> assume "$@" list */
8476 /* create list of variable values */
8477 debug_print_strings("for_list made from", vals);
8478 for_list = expand_strvec_to_strvec(vals);
8479 for_lcur = for_list;
8480 debug_print_strings("for_list", for_list);
8483 /* "for" loop is over, clean up */
8489 /* Insert next value from for_lcur */
8490 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8491 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8494 if (rword == RES_IN) {
8495 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8497 if (rword == RES_DONE) {
8498 continue; /* "done" has no cmds too */
8501 #if ENABLE_HUSH_CASE
8502 if (rword == RES_CASE) {
8503 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8504 case_word = expand_strvec_to_string(pi->cmds->argv);
8505 unbackslash(case_word);
8508 if (rword == RES_MATCH) {
8511 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8512 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8514 /* all prev words didn't match, does this one match? */
8515 argv = pi->cmds->argv;
8517 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8518 /* TODO: which FNM_xxx flags to use? */
8519 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8520 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8522 if (cond_code == 0) { /* match! we will execute this branch */
8524 case_word = NULL; /* make future "word)" stop */
8531 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8532 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8534 continue; /* not matched yet, skip this pipe */
8536 if (rword == RES_ESAC) {
8537 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8539 /* "case" did not match anything: still set $? (to 0) */
8540 G.last_exitcode = rcode = EXIT_SUCCESS;
8544 /* Just pressing <enter> in shell should check for jobs.
8545 * OTOH, in non-interactive shell this is useless
8546 * and only leads to extra job checks */
8547 if (pi->num_cmds == 0) {
8548 if (G_interactive_fd)
8549 goto check_jobs_and_continue;
8553 /* After analyzing all keywords and conditions, we decided
8554 * to execute this pipe. NB: have to do checkjobs(NULL)
8555 * after run_pipe to collect any background children,
8556 * even if list execution is to be stopped. */
8557 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8558 #if ENABLE_HUSH_LOOPS
8559 G.flag_break_continue = 0;
8561 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8563 /* We ran a builtin, function, or group.
8564 * rcode is already known
8565 * and we don't need to wait for anything. */
8566 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8567 G.last_exitcode = rcode;
8568 check_and_run_traps();
8569 #if ENABLE_HUSH_LOOPS
8570 /* Was it "break" or "continue"? */
8571 if (G.flag_break_continue) {
8572 smallint fbc = G.flag_break_continue;
8573 /* We might fall into outer *loop*,
8574 * don't want to break it too */
8576 G.depth_break_continue--;
8577 if (G.depth_break_continue == 0)
8578 G.flag_break_continue = 0;
8579 /* else: e.g. "continue 2" should *break* once, *then* continue */
8580 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8581 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8582 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8585 /* "continue": simulate end of loop */
8590 if (G_flag_return_in_progress == 1) {
8591 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8594 } else if (pi->followup == PIPE_BG) {
8595 /* What does bash do with attempts to background builtins? */
8596 /* even bash 3.2 doesn't do that well with nested bg:
8597 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8598 * I'm NOT treating inner &'s as jobs */
8600 if (G.run_list_level == 1)
8601 insert_job_into_table(pi);
8603 /* Last command's pid goes to $! */
8604 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8605 G.last_bg_pid_exitcode = 0;
8606 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8607 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8608 rcode = EXIT_SUCCESS;
8612 if (G.run_list_level == 1 && G_interactive_fd) {
8613 /* Waits for completion, then fg's main shell */
8614 rcode = checkjobs_and_fg_shell(pi);
8615 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8619 /* This one just waits for completion */
8620 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8621 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8623 G.last_exitcode = rcode;
8624 check_and_run_traps();
8627 /* Handle "set -e" */
8628 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8629 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8630 if (G.errexit_depth == 0)
8633 G.errexit_depth = sv_errexit_depth;
8635 /* Analyze how result affects subsequent commands */
8637 if (rword == RES_IF || rword == RES_ELIF)
8640 check_jobs_and_continue:
8641 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8642 dont_check_jobs_but_continue: ;
8643 #if ENABLE_HUSH_LOOPS
8644 /* Beware of "while false; true; do ..."! */
8646 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8647 /* check for RES_DONE is needed for "while ...; do \n done" case */
8649 if (rword == RES_WHILE) {
8651 /* "while false; do...done" - exitcode 0 */
8652 G.last_exitcode = rcode = EXIT_SUCCESS;
8653 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8657 if (rword == RES_UNTIL) {
8659 debug_printf_exec(": until expr is true: breaking\n");
8670 #if ENABLE_HUSH_LOOPS
8675 #if ENABLE_HUSH_CASE
8679 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8683 /* Select which version we will use */
8684 static int run_and_free_list(struct pipe *pi)
8687 debug_printf_exec("run_and_free_list entered\n");
8688 if (!G.o_opt[OPT_O_NOEXEC]) {
8689 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8690 rcode = run_list(pi);
8692 /* free_pipe_list has the side effect of clearing memory.
8693 * In the long run that function can be merged with run_list,
8694 * but doing that now would hobble the debugging effort. */
8696 debug_printf_exec("run_and_free_list return %d\n", rcode);
8701 static void install_sighandlers(unsigned mask)
8703 sighandler_t old_handler;
8705 while ((mask >>= 1) != 0) {
8709 old_handler = install_sighandler(sig, pick_sighandler(sig));
8710 /* POSIX allows shell to re-enable SIGCHLD
8711 * even if it was SIG_IGN on entry.
8712 * Therefore we skip IGN check for it:
8716 /* bash re-enables SIGHUP which is SIG_IGNed on entry.
8717 * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
8719 //if (sig == SIGHUP) continue; - TODO?
8720 if (old_handler == SIG_IGN) {
8721 /* oops... restore back to IGN, and record this fact */
8722 install_sighandler(sig, old_handler);
8723 #if ENABLE_HUSH_TRAP
8725 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8727 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8733 /* Called a few times only (or even once if "sh -c") */
8734 static void install_special_sighandlers(void)
8738 /* Which signals are shell-special? */
8739 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8740 if (G_interactive_fd) {
8741 mask |= SPECIAL_INTERACTIVE_SIGS;
8742 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8743 mask |= SPECIAL_JOBSTOP_SIGS;
8745 /* Careful, do not re-install handlers we already installed */
8746 if (G.special_sig_mask != mask) {
8747 unsigned diff = mask & ~G.special_sig_mask;
8748 G.special_sig_mask = mask;
8749 install_sighandlers(diff);
8755 /* Set handlers to restore tty pgrp and exit */
8756 static void install_fatal_sighandlers(void)
8760 /* We will restore tty pgrp on these signals */
8762 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8763 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8764 + (1 << SIGBUS ) * HUSH_DEBUG
8765 + (1 << SIGSEGV) * HUSH_DEBUG
8766 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8768 /* bash 3.2 seems to handle these just like 'fatal' ones */
8771 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8772 * if we aren't interactive... but in this case
8773 * we never want to restore pgrp on exit, and this fn is not called
8775 /*+ (1 << SIGHUP )*/
8776 /*+ (1 << SIGTERM)*/
8777 /*+ (1 << SIGINT )*/
8779 G_fatal_sig_mask = mask;
8781 install_sighandlers(mask);
8785 static int set_mode(int state, char mode, const char *o_opt)
8790 G.o_opt[OPT_O_NOEXEC] = state;
8793 IF_HUSH_MODE_X(G_x_mode = state;)
8797 /* "set -+o" without parameter.
8798 * in bash, set -o produces this output:
8802 * We always use the second form.
8804 const char *p = o_opt_strings;
8807 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8813 idx = index_in_strings(o_opt_strings, o_opt);
8815 G.o_opt[idx] = state;
8819 G.o_opt[OPT_O_ERREXIT] = state;
8822 return EXIT_FAILURE;
8824 return EXIT_SUCCESS;
8827 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8828 int hush_main(int argc, char **argv)
8831 OPT_login = (1 << 0),
8835 unsigned builtin_argc;
8837 struct variable *cur_var;
8838 struct variable *shell_ver;
8841 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8842 G.last_exitcode = EXIT_SUCCESS;
8844 #if ENABLE_HUSH_FAST
8845 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8848 G.argv0_for_re_execing = argv[0];
8850 /* Deal with HUSH_VERSION */
8851 shell_ver = xzalloc(sizeof(*shell_ver));
8852 shell_ver->flg_export = 1;
8853 shell_ver->flg_read_only = 1;
8854 /* Code which handles ${var<op>...} needs writable values for all variables,
8855 * therefore we xstrdup: */
8856 shell_ver->varstr = xstrdup(hush_version_str);
8857 /* Create shell local variables from the values
8858 * currently living in the environment */
8859 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8860 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8861 G.top_var = shell_ver;
8862 cur_var = G.top_var;
8865 char *value = strchr(*e, '=');
8866 if (value) { /* paranoia */
8867 cur_var->next = xzalloc(sizeof(*cur_var));
8868 cur_var = cur_var->next;
8869 cur_var->varstr = *e;
8870 cur_var->max_len = strlen(*e);
8871 cur_var->flg_export = 1;
8875 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8876 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8877 putenv(shell_ver->varstr);
8880 set_pwd_var(SETFLAG_EXPORT);
8882 #if BASH_HOSTNAME_VAR
8883 /* Set (but not export) HOSTNAME unless already set */
8884 if (!get_local_var_value("HOSTNAME")) {
8887 set_local_var_from_halves("HOSTNAME", uts.nodename);
8889 /* bash also exports SHLVL and _,
8890 * and sets (but doesn't export) the following variables:
8892 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8893 * BASH_VERSION='3.2.0(1)-release'
8895 * MACHTYPE=i386-pc-linux-gnu
8897 * PPID=<NNNNN> - we also do it elsewhere
8908 * PIPESTATUS=([0]="0")
8909 * HISTFILE=/<xxx>/.bash_history
8913 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8915 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8926 #if ENABLE_FEATURE_EDITING
8927 G.line_input_state = new_line_input_t(FOR_SHELL);
8930 /* Initialize some more globals to non-zero values */
8931 cmdedit_update_prompt();
8933 die_func = restore_ttypgrp_and__exit;
8935 /* Shell is non-interactive at first. We need to call
8936 * install_special_sighandlers() if we are going to execute "sh <script>",
8937 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8938 * If we later decide that we are interactive, we run install_special_sighandlers()
8939 * in order to intercept (more) signals.
8943 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8944 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8947 opt = getopt(argc, argv, "+c:exinsl"
8950 # if ENABLE_HUSH_FUNCTIONS
8960 * sh ... -c 'script'
8961 * sh ... -c 'script' ARG0 [ARG1...]
8962 * On NOMMU, if builtin_argc != 0,
8963 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8964 * "" needs to be replaced with NULL
8965 * and BARGV vector fed to builtin function.
8966 * Note: the form without ARG0 never happens:
8967 * sh ... -c 'builtin' BARGV... ""
8970 G.root_pid = getpid();
8971 G.root_ppid = getppid();
8973 G.global_argv = argv + optind;
8974 G.global_argc = argc - optind;
8976 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8977 const struct built_in_command *x;
8979 install_special_sighandlers();
8980 x = find_builtin(optarg);
8981 if (x) { /* paranoia */
8982 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8983 G.global_argv += builtin_argc;
8984 G.global_argv[-1] = NULL; /* replace "" */
8986 G.last_exitcode = x->b_function(argv + optind - 1);
8990 if (!G.global_argv[0]) {
8991 /* -c 'script' (no params): prevent empty $0 */
8992 G.global_argv--; /* points to argv[i] of 'script' */
8993 G.global_argv[0] = argv[0];
8995 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8996 install_special_sighandlers();
8997 parse_and_run_string(optarg);
9000 /* Well, we cannot just declare interactiveness,
9001 * we have to have some stuff (ctty, etc) */
9002 /* G_interactive_fd++; */
9005 /* "-s" means "read from stdin", but this is how we always
9006 * operate, so simply do nothing here. */
9012 case '<': /* "big heredoc" support */
9013 full_write1_str(optarg);
9016 unsigned long long empty_trap_mask;
9018 G.root_pid = bb_strtou(optarg, &optarg, 16);
9020 G.root_ppid = bb_strtou(optarg, &optarg, 16);
9022 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
9024 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
9026 builtin_argc = bb_strtou(optarg, &optarg, 16);
9028 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
9029 if (empty_trap_mask != 0) {
9030 IF_HUSH_TRAP(int sig;)
9031 install_special_sighandlers();
9032 # if ENABLE_HUSH_TRAP
9033 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9034 for (sig = 1; sig < NSIG; sig++) {
9035 if (empty_trap_mask & (1LL << sig)) {
9036 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
9037 install_sighandler(sig, SIG_IGN);
9042 # if ENABLE_HUSH_LOOPS
9044 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
9050 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
9052 # if ENABLE_HUSH_FUNCTIONS
9054 struct function *funcp = new_function(optarg);
9055 /* funcp->name is already set to optarg */
9056 /* funcp->body is set to NULL. It's a special case. */
9057 funcp->body_as_string = argv[optind];
9066 if (set_mode(1, opt, NULL) == 0) /* no error */
9070 fprintf(stderr, "Usage: sh [FILE]...\n"
9071 " or: sh -c command [args]...\n\n");
9077 } /* option parsing loop */
9079 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9080 G.global_argc = argc - (optind - 1);
9081 G.global_argv = argv + (optind - 1);
9082 G.global_argv[0] = argv[0];
9085 G.root_pid = getpid();
9086 G.root_ppid = getppid();
9089 /* If we are login shell... */
9090 if (flags & OPT_login) {
9092 debug_printf("sourcing /etc/profile\n");
9093 input = fopen_for_read("/etc/profile");
9094 if (input != NULL) {
9095 remember_FILE(input);
9096 install_special_sighandlers();
9097 parse_and_run_file(input);
9098 fclose_and_forget(input);
9100 /* bash: after sourcing /etc/profile,
9101 * tries to source (in the given order):
9102 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9103 * stopping on first found. --noprofile turns this off.
9104 * bash also sources ~/.bash_logout on exit.
9105 * If called as sh, skips .bash_XXX files.
9109 if (G.global_argv[1]) {
9112 * "bash <script>" (which is never interactive (unless -i?))
9113 * sources $BASH_ENV here (without scanning $PATH).
9114 * If called as sh, does the same but with $ENV.
9115 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9119 debug_printf("running script '%s'\n", G.global_argv[0]);
9120 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9121 input = xfopen_for_read(G.global_argv[0]);
9122 xfunc_error_retval = 1;
9123 remember_FILE(input);
9124 install_special_sighandlers();
9125 parse_and_run_file(input);
9126 #if ENABLE_FEATURE_CLEAN_UP
9127 fclose_and_forget(input);
9132 /* Up to here, shell was non-interactive. Now it may become one.
9133 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9136 /* A shell is interactive if the '-i' flag was given,
9137 * or if all of the following conditions are met:
9139 * no arguments remaining or the -s flag given
9140 * standard input is a terminal
9141 * standard output is a terminal
9142 * Refer to Posix.2, the description of the 'sh' utility.
9145 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9146 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9147 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9148 if (G_saved_tty_pgrp < 0)
9149 G_saved_tty_pgrp = 0;
9151 /* try to dup stdin to high fd#, >= 255 */
9152 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9153 if (G_interactive_fd < 0) {
9154 /* try to dup to any fd */
9155 G_interactive_fd = dup(STDIN_FILENO);
9156 if (G_interactive_fd < 0) {
9158 G_interactive_fd = 0;
9159 G_saved_tty_pgrp = 0;
9162 // TODO: track & disallow any attempts of user
9163 // to (inadvertently) close/redirect G_interactive_fd
9165 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9166 if (G_interactive_fd) {
9167 close_on_exec_on(G_interactive_fd);
9169 if (G_saved_tty_pgrp) {
9170 /* If we were run as 'hush &', sleep until we are
9171 * in the foreground (tty pgrp == our pgrp).
9172 * If we get started under a job aware app (like bash),
9173 * make sure we are now in charge so we don't fight over
9174 * who gets the foreground */
9176 pid_t shell_pgrp = getpgrp();
9177 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9178 if (G_saved_tty_pgrp == shell_pgrp)
9180 /* send TTIN to ourself (should stop us) */
9181 kill(- shell_pgrp, SIGTTIN);
9185 /* Install more signal handlers */
9186 install_special_sighandlers();
9188 if (G_saved_tty_pgrp) {
9189 /* Set other signals to restore saved_tty_pgrp */
9190 install_fatal_sighandlers();
9191 /* Put ourselves in our own process group
9192 * (bash, too, does this only if ctty is available) */
9193 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9194 /* Grab control of the terminal */
9195 tcsetpgrp(G_interactive_fd, getpid());
9197 enable_restore_tty_pgrp_on_exit();
9199 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9201 const char *hp = get_local_var_value("HISTFILE");
9203 hp = get_local_var_value("HOME");
9205 hp = concat_path_file(hp, ".hush_history");
9210 G.line_input_state->hist_file = hp;
9211 //set_local_var(xasprintf("HISTFILE=%s", ...));
9213 # if ENABLE_FEATURE_SH_HISTFILESIZE
9214 hp = get_local_var_value("HISTFILESIZE");
9215 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9220 install_special_sighandlers();
9222 #elif ENABLE_HUSH_INTERACTIVE
9223 /* No job control compiled in, only prompt/line editing */
9224 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9225 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9226 if (G_interactive_fd < 0) {
9227 /* try to dup to any fd */
9228 G_interactive_fd = dup(STDIN_FILENO);
9229 if (G_interactive_fd < 0)
9231 G_interactive_fd = 0;
9234 if (G_interactive_fd) {
9235 close_on_exec_on(G_interactive_fd);
9237 install_special_sighandlers();
9239 /* We have interactiveness code disabled */
9240 install_special_sighandlers();
9243 * if interactive but not a login shell, sources ~/.bashrc
9244 * (--norc turns this off, --rcfile <file> overrides)
9247 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9248 /* note: ash and hush share this string */
9249 printf("\n\n%s %s\n"
9250 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9253 "hush - the humble shell"
9257 parse_and_run_file(stdin);
9260 hush_exit(G.last_exitcode);
9267 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9272 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9273 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9275 int argc = string_array_len(argv);
9276 return applet_main_func(argc, argv);
9279 #if ENABLE_HUSH_TEST || BASH_TEST2
9280 static int FAST_FUNC builtin_test(char **argv)
9282 return run_applet_main(argv, test_main);
9285 #if ENABLE_HUSH_ECHO
9286 static int FAST_FUNC builtin_echo(char **argv)
9288 return run_applet_main(argv, echo_main);
9291 #if ENABLE_HUSH_PRINTF
9292 static int FAST_FUNC builtin_printf(char **argv)
9294 return run_applet_main(argv, printf_main);
9298 #if ENABLE_HUSH_HELP
9299 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9301 const struct built_in_command *x;
9304 "Built-in commands:\n"
9305 "------------------\n");
9306 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9308 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9310 return EXIT_SUCCESS;
9314 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9315 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9317 show_history(G.line_input_state);
9318 return EXIT_SUCCESS;
9322 static char **skip_dash_dash(char **argv)
9325 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9330 static int FAST_FUNC builtin_cd(char **argv)
9334 argv = skip_dash_dash(argv);
9336 if (newdir == NULL) {
9337 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9338 * bash says "bash: cd: HOME not set" and does nothing
9341 const char *home = get_local_var_value("HOME");
9342 newdir = home ? home : "/";
9344 if (chdir(newdir)) {
9345 /* Mimic bash message exactly */
9346 bb_perror_msg("cd: %s", newdir);
9347 return EXIT_FAILURE;
9349 /* Read current dir (get_cwd(1) is inside) and set PWD.
9350 * Note: do not enforce exporting. If PWD was unset or unexported,
9351 * set it again, but do not export. bash does the same.
9353 set_pwd_var(/*flag:*/ 0);
9354 return EXIT_SUCCESS;
9357 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9360 return EXIT_SUCCESS;
9363 static int FAST_FUNC builtin_eval(char **argv)
9365 int rcode = EXIT_SUCCESS;
9367 argv = skip_dash_dash(argv);
9372 /* "The eval utility shall construct a command by
9373 * concatenating arguments together, separating
9374 * each with a <space> character."
9380 len += strlen(*pp) + 1;
9382 str = p = xmalloc(len);
9392 * eval "echo Hi; done" ("done" is syntax error):
9393 * "echo Hi" will not execute too.
9395 parse_and_run_string(str ? str : argv[0]);
9397 rcode = G.last_exitcode;
9402 static int FAST_FUNC builtin_exec(char **argv)
9404 argv = skip_dash_dash(argv);
9405 if (argv[0] == NULL)
9406 return EXIT_SUCCESS; /* bash does this */
9408 /* Careful: we can end up here after [v]fork. Do not restore
9409 * tty pgrp then, only top-level shell process does that */
9410 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9411 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9413 /* Saved-redirect fds, script fds and G_interactive_fd are still
9414 * open here. However, they are all CLOEXEC, and execv below
9415 * closes them. Try interactive "exec ls -l /proc/self/fd",
9416 * it should show no extra open fds in the "ls" process.
9417 * If we'd try to run builtins/NOEXECs, this would need improving.
9419 //close_saved_fds_and_FILE_fds();
9421 /* TODO: if exec fails, bash does NOT exit! We do.
9422 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9423 * and tcsetpgrp, and this is inherently racy.
9425 execvp_or_die(argv);
9428 static int FAST_FUNC builtin_exit(char **argv)
9430 debug_printf_exec("%s()\n", __func__);
9432 /* interactive bash:
9433 * # trap "echo EEE" EXIT
9436 * There are stopped jobs.
9437 * (if there are _stopped_ jobs, running ones don't count)
9440 * EEE (then bash exits)
9442 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9445 /* note: EXIT trap is run by hush_exit */
9446 argv = skip_dash_dash(argv);
9447 if (argv[0] == NULL)
9448 hush_exit(G.last_exitcode);
9449 /* mimic bash: exit 123abc == exit 255 + error msg */
9450 xfunc_error_retval = 255;
9451 /* bash: exit -2 == exit 254, no error msg */
9452 hush_exit(xatoi(argv[0]) & 0xff);
9455 #if ENABLE_HUSH_TYPE
9456 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9457 static int FAST_FUNC builtin_type(char **argv)
9459 int ret = EXIT_SUCCESS;
9465 if (0) {} /* make conditional compile easier below */
9466 /*else if (find_alias(*argv))
9467 type = "an alias";*/
9468 #if ENABLE_HUSH_FUNCTIONS
9469 else if (find_function(*argv))
9470 type = "a function";
9472 else if (find_builtin(*argv))
9473 type = "a shell builtin";
9474 else if ((path = find_in_path(*argv)) != NULL)
9477 bb_error_msg("type: %s: not found", *argv);
9482 printf("%s is %s\n", *argv, type);
9490 #if ENABLE_HUSH_READ
9491 /* Interruptibility of read builtin in bash
9492 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9494 * Empty trap makes read ignore corresponding signal, for any signal.
9497 * - terminates non-interactive shell;
9498 * - interrupts read in interactive shell;
9499 * if it has non-empty trap:
9500 * - executes trap and returns to command prompt in interactive shell;
9501 * - executes trap and returns to read in non-interactive shell;
9503 * - is ignored (does not interrupt) read in interactive shell;
9504 * - terminates non-interactive shell;
9505 * if it has non-empty trap:
9506 * - executes trap and returns to read;
9508 * - terminates shell (regardless of interactivity);
9509 * if it has non-empty trap:
9510 * - executes trap and returns to read;
9511 * SIGCHLD from children:
9512 * - does not interrupt read regardless of interactivity:
9513 * try: sleep 1 & read x; echo $x
9515 static int FAST_FUNC builtin_read(char **argv)
9522 char *opt_d = NULL; /* optimized out if !BASH */
9526 /* "!": do not abort on errors.
9527 * Option string must start with "sr" to match BUILTIN_READ_xxx
9529 read_flags = getopt32(argv,
9531 "!srn:p:t:u:d:", &opt_n, &opt_p, &opt_t, &opt_u, &opt_d
9533 "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u
9536 if (read_flags == (uint32_t)-1)
9537 return EXIT_FAILURE;
9539 ifs = get_local_var_value("IFS"); /* can be NULL */
9542 r = shell_builtin_read(set_local_var_from_halves,
9553 if ((uintptr_t)r == 1 && errno == EINTR) {
9554 unsigned sig = check_and_run_traps();
9559 if ((uintptr_t)r > 1) {
9560 bb_error_msg("%s", r);
9561 r = (char*)(uintptr_t)1;
9564 return (uintptr_t)r;
9568 #if ENABLE_HUSH_UMASK
9569 static int FAST_FUNC builtin_umask(char **argv)
9576 argv = skip_dash_dash(argv);
9578 mode_t old_mask = mask;
9580 /* numeric umasks are taken as-is */
9581 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9582 if (!isdigit(argv[0][0]))
9584 mask = bb_parse_mode(argv[0], mask);
9585 if (!isdigit(argv[0][0]))
9587 if ((unsigned)mask > 0777) {
9590 * bash: umask: 'q': invalid symbolic mode operator
9591 * bash: umask: 999: octal number out of range
9593 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9598 printf("%04o\n", (unsigned) mask);
9599 /* fall through and restore mask which we set to 0 */
9603 return !rc; /* rc != 0 - success */
9607 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9608 static void print_escaped(const char *s)
9613 const char *p = strchrnul(s, '\'');
9614 /* print 'xxxx', possibly just '' */
9615 printf("'%.*s'", (int)(p - s), s);
9620 /* s points to '; print "'''...'''" */
9622 do putchar('\''); while (*++s == '\'');
9628 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9629 static int helper_export_local(char **argv, unsigned flags)
9633 char *name_end = strchrnul(name, '=');
9635 /* So far we do not check that name is valid (TODO?) */
9637 if (*name_end == '\0') {
9638 struct variable *var, **vpp;
9640 vpp = get_ptr_to_local_var(name, name_end - name);
9641 var = vpp ? *vpp : NULL;
9643 if (flags & SETFLAG_UNEXPORT) {
9644 /* export -n NAME (without =VALUE) */
9646 var->flg_export = 0;
9647 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9649 } /* else: export -n NOT_EXISTING_VAR: no-op */
9652 if (flags & SETFLAG_EXPORT) {
9653 /* export NAME (without =VALUE) */
9655 var->flg_export = 1;
9656 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9657 putenv(var->varstr);
9661 if (flags & SETFLAG_MAKE_RO) {
9662 /* readonly NAME (without =VALUE) */
9664 var->flg_read_only = 1;
9668 # if ENABLE_HUSH_LOCAL
9669 /* Is this "local" bltin? */
9670 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9671 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9672 if (var && var->func_nest_level == lvl) {
9673 /* "local x=abc; ...; local x" - ignore second local decl */
9678 /* Exporting non-existing variable.
9679 * bash does not put it in environment,
9680 * but remembers that it is exported,
9681 * and does put it in env when it is set later.
9682 * We just set it to "" and export.
9684 /* Or, it's "local NAME" (without =VALUE).
9685 * bash sets the value to "".
9687 /* Or, it's "readonly NAME" (without =VALUE).
9688 * bash remembers NAME and disallows its creation
9691 name = xasprintf("%s=", name);
9693 /* (Un)exporting/making local NAME=VALUE */
9694 name = xstrdup(name);
9696 if (set_local_var(name, flags))
9697 return EXIT_FAILURE;
9699 return EXIT_SUCCESS;
9703 #if ENABLE_HUSH_EXPORT
9704 static int FAST_FUNC builtin_export(char **argv)
9706 unsigned opt_unexport;
9708 #if ENABLE_HUSH_EXPORT_N
9709 /* "!": do not abort on errors */
9710 opt_unexport = getopt32(argv, "!n");
9711 if (opt_unexport == (uint32_t)-1)
9712 return EXIT_FAILURE;
9719 if (argv[0] == NULL) {
9726 /* ash emits: export VAR='VAL'
9727 * bash: declare -x VAR="VAL"
9728 * we follow ash example */
9729 const char *s = *e++;
9730 const char *p = strchr(s, '=');
9732 if (!p) /* wtf? take next variable */
9735 printf("export %.*s", (int)(p - s) + 1, s);
9736 print_escaped(p + 1);
9740 /*fflush_all(); - done after each builtin anyway */
9742 return EXIT_SUCCESS;
9745 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9749 #if ENABLE_HUSH_LOCAL
9750 static int FAST_FUNC builtin_local(char **argv)
9752 if (G.func_nest_level == 0) {
9753 bb_error_msg("%s: not in a function", argv[0]);
9754 return EXIT_FAILURE; /* bash compat */
9757 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9761 #if ENABLE_HUSH_READONLY
9762 static int FAST_FUNC builtin_readonly(char **argv)
9765 if (*argv == NULL) {
9766 /* bash: readonly [-p]: list all readonly VARs
9767 * (-p has no effect in bash)
9770 for (e = G.top_var; e; e = e->next) {
9771 if (e->flg_read_only) {
9772 //TODO: quote value: readonly VAR='VAL'
9773 printf("readonly %s\n", e->varstr);
9776 return EXIT_SUCCESS;
9778 return helper_export_local(argv, SETFLAG_MAKE_RO);
9782 #if ENABLE_HUSH_UNSET
9783 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9784 static int FAST_FUNC builtin_unset(char **argv)
9789 /* "!": do not abort on errors */
9790 /* "+": stop at 1st non-option */
9791 opts = getopt32(argv, "!+vf");
9792 if (opts == (unsigned)-1)
9793 return EXIT_FAILURE;
9795 bb_error_msg("unset: -v and -f are exclusive");
9796 return EXIT_FAILURE;
9802 if (!(opts & 2)) { /* not -f */
9803 if (unset_local_var(*argv)) {
9804 /* unset <nonexistent_var> doesn't fail.
9805 * Error is when one tries to unset RO var.
9806 * Message was printed by unset_local_var. */
9810 # if ENABLE_HUSH_FUNCTIONS
9822 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9823 * built-in 'set' handler
9825 * set [-abCefhmnuvx] [-o option] [argument...]
9826 * set [+abCefhmnuvx] [+o option] [argument...]
9827 * set -- [argument...]
9830 * Implementations shall support the options in both their hyphen and
9831 * plus-sign forms. These options can also be specified as options to sh.
9833 * Write out all variables and their values: set
9834 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9835 * Turn on the -x and -v options: set -xv
9836 * Unset all positional parameters: set --
9837 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9838 * Set the positional parameters to the expansion of x, even if x expands
9839 * with a leading '-' or '+': set -- $x
9841 * So far, we only support "set -- [argument...]" and some of the short names.
9843 static int FAST_FUNC builtin_set(char **argv)
9846 char **pp, **g_argv;
9847 char *arg = *++argv;
9851 for (e = G.top_var; e; e = e->next)
9853 return EXIT_SUCCESS;
9857 if (strcmp(arg, "--") == 0) {
9861 if (arg[0] != '+' && arg[0] != '-')
9863 for (n = 1; arg[n]; ++n) {
9864 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9866 if (arg[n] == 'o' && argv[1])
9869 } while ((arg = *++argv) != NULL);
9870 /* Now argv[0] is 1st argument */
9873 return EXIT_SUCCESS;
9876 /* NB: G.global_argv[0] ($0) is never freed/changed */
9877 g_argv = G.global_argv;
9878 if (G.global_args_malloced) {
9884 G.global_args_malloced = 1;
9885 pp = xzalloc(sizeof(pp[0]) * 2);
9886 pp[0] = g_argv[0]; /* retain $0 */
9889 /* This realloc's G.global_argv */
9890 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9892 G.global_argc = 1 + string_array_len(pp + 1);
9894 return EXIT_SUCCESS;
9896 /* Nothing known, so abort */
9898 bb_error_msg("set: %s: invalid option", arg);
9899 return EXIT_FAILURE;
9903 static int FAST_FUNC builtin_shift(char **argv)
9906 argv = skip_dash_dash(argv);
9908 n = bb_strtou(argv[0], NULL, 10);
9909 if (errno || n < 0) {
9910 /* shared string with ash.c */
9911 bb_error_msg("Illegal number: %s", argv[0]);
9913 * ash aborts in this case.
9914 * bash prints error message and set $? to 1.
9915 * Interestingly, for "shift 99999" bash does not
9916 * print error message, but does set $? to 1
9917 * (and does no shifting at all).
9921 if (n >= 0 && n < G.global_argc) {
9922 if (G_global_args_malloced) {
9925 free(G.global_argv[m++]);
9928 memmove(&G.global_argv[1], &G.global_argv[n+1],
9929 G.global_argc * sizeof(G.global_argv[0]));
9930 return EXIT_SUCCESS;
9932 return EXIT_FAILURE;
9935 #if ENABLE_HUSH_GETOPTS
9936 static int FAST_FUNC builtin_getopts(char **argv)
9938 /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
9941 If a required argument is not found, and getopts is not silent,
9942 a question mark (?) is placed in VAR, OPTARG is unset, and a
9943 diagnostic message is printed. If getopts is silent, then a
9944 colon (:) is placed in VAR and OPTARG is set to the option
9947 Test that VAR is a valid variable name?
9949 "Whenever the shell is invoked, OPTIND shall be initialized to 1"
9952 const char *cp, *optstring, *var;
9953 int c, n, exitcode, my_opterr;
9956 optstring = *++argv;
9957 if (!optstring || !(var = *++argv)) {
9958 bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
9959 return EXIT_FAILURE;
9963 argv[0] = G.global_argv[0]; /* for error messages in getopt() */
9965 argv = G.global_argv;
9969 if (optstring[0] != ':') {
9970 cp = get_local_var_value("OPTERR");
9971 /* 0 if "OPTERR=0", 1 otherwise */
9972 my_opterr = (!cp || NOT_LONE_CHAR(cp, '0'));
9975 /* getopts stops on first non-option. Add "+" to force that */
9976 /*if (optstring[0] != '+')*/ {
9977 char *s = alloca(strlen(optstring) + 2);
9978 sprintf(s, "+%s", optstring);
9982 /* Naively, now we should just
9983 * cp = get_local_var_value("OPTIND");
9984 * optind = cp ? atoi(cp) : 0;
9986 * opterr = my_opterr;
9987 * c = getopt(string_array_len(argv), argv, optstring);
9988 * and be done? Not so fast...
9989 * Unlike normal getopt() usage in C programs, here
9990 * each successive call will (usually) have the same argv[] CONTENTS,
9991 * but not the ADDRESSES. Worse yet, it's possible that between
9992 * invocations of "getopts", there will be calls to shell builtins
9993 * which use getopt() internally. Example:
9994 * while getopts "abc" RES -a -bc -abc de; do
9997 * This would not work correctly: getopt() call inside "unset"
9998 * modifies internal libc state which is tracking position in
9999 * multi-option strings ("-abc"). At best, it can skip options
10000 * or return the same option infinitely. With glibc implementation
10001 * of getopt(), it would use outright invalid pointers and return
10002 * garbage even _without_ "unset" mangling internal state.
10004 * We resort to resetting getopt() state and calling it N times,
10005 * until we get Nth result (or failure).
10006 * (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set).
10010 n = string_array_len(argv);
10013 opterr = (count < G.getopt_count) ? 0 : my_opterr;
10014 c = getopt(n, argv, optstring);
10018 } while (count <= G.getopt_count);
10020 /* Set OPTIND. Prevent resetting of the magic counter! */
10021 set_local_var_from_halves("OPTIND", utoa(optind));
10022 G.getopt_count = count; /* "next time, give me N+1'th result" */
10023 GETOPT_RESET(); /* just in case */
10026 /* Always set or unset, never left as-is, even on exit/error:
10027 * "If no option was found, or if the option that was found
10028 * does not have an option-argument, OPTARG shall be unset."
10032 /* If ":optstring" and unknown option is seen,
10033 * it is stored to OPTARG.
10035 if (optstring[1] == ':') {
10041 set_local_var_from_halves("OPTARG", cp);
10043 unset_local_var("OPTARG");
10045 /* Convert -1 to "?" */
10046 exitcode = EXIT_SUCCESS;
10047 if (c < 0) { /* -1: end of options */
10048 exitcode = EXIT_FAILURE;
10054 set_local_var_from_halves(var, cbuf);
10060 static int FAST_FUNC builtin_source(char **argv)
10062 char *arg_path, *filename;
10065 char *args_need_save;
10066 #if ENABLE_HUSH_FUNCTIONS
10070 argv = skip_dash_dash(argv);
10071 filename = argv[0];
10073 /* bash says: "bash: .: filename argument required" */
10074 return 2; /* bash compat */
10077 if (!strchr(filename, '/')) {
10078 arg_path = find_in_path(filename);
10080 filename = arg_path;
10082 input = remember_FILE(fopen_or_warn(filename, "r"));
10085 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
10086 /* POSIX: non-interactive shell should abort here,
10087 * not merely fail. So far no one complained :)
10089 return EXIT_FAILURE;
10092 #if ENABLE_HUSH_FUNCTIONS
10093 sv_flg = G_flag_return_in_progress;
10094 /* "we are inside sourced file, ok to use return" */
10095 G_flag_return_in_progress = -1;
10097 args_need_save = argv[1]; /* used as a boolean variable */
10098 if (args_need_save)
10099 save_and_replace_G_args(&sv, argv);
10101 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
10102 G.last_exitcode = 0;
10103 parse_and_run_file(input);
10104 fclose_and_forget(input);
10106 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
10107 restore_G_args(&sv, argv);
10108 #if ENABLE_HUSH_FUNCTIONS
10109 G_flag_return_in_progress = sv_flg;
10112 return G.last_exitcode;
10115 #if ENABLE_HUSH_TRAP
10116 static int FAST_FUNC builtin_trap(char **argv)
10122 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
10127 /* No args: print all trapped */
10128 for (i = 0; i < NSIG; ++i) {
10130 printf("trap -- ");
10131 print_escaped(G_traps[i]);
10132 /* note: bash adds "SIG", but only if invoked
10133 * as "bash". If called as "sh", or if set -o posix,
10134 * then it prints short signal names.
10135 * We are printing short names: */
10136 printf(" %s\n", get_signame(i));
10139 /*fflush_all(); - done after each builtin anyway */
10140 return EXIT_SUCCESS;
10144 /* If first arg is a number: reset all specified signals */
10145 sig = bb_strtou(*argv, NULL, 10);
10149 ret = EXIT_SUCCESS;
10151 sighandler_t handler;
10153 sig = get_signum(*argv++);
10155 ret = EXIT_FAILURE;
10156 /* Mimic bash message exactly */
10157 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
10161 free(G_traps[sig]);
10162 G_traps[sig] = xstrdup(new_cmd);
10164 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
10165 get_signame(sig), sig, G_traps[sig]);
10167 /* There is no signal for 0 (EXIT) */
10172 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
10174 /* We are removing trap handler */
10175 handler = pick_sighandler(sig);
10176 install_sighandler(sig, handler);
10181 if (!argv[1]) { /* no second arg */
10182 bb_error_msg("trap: invalid arguments");
10183 return EXIT_FAILURE;
10186 /* First arg is "-": reset all specified to default */
10187 /* First arg is "--": skip it, the rest is "handler SIGs..." */
10188 /* Everything else: set arg as signal handler
10189 * (includes "" case, which ignores signal) */
10190 if (argv[0][0] == '-') {
10191 if (argv[0][1] == '\0') { /* "-" */
10192 /* new_cmd remains NULL: "reset these sigs" */
10195 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
10198 /* else: "-something", no special meaning */
10203 goto process_sig_list;
10207 #if ENABLE_HUSH_JOB
10208 static struct pipe *parse_jobspec(const char *str)
10213 if (sscanf(str, "%%%u", &jobnum) != 1) {
10215 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
10217 bb_error_msg("bad argument '%s'", str);
10220 /* It is "%%", "%+" or "%" - current job */
10221 jobnum = G.last_jobid;
10223 bb_error_msg("no current job");
10227 for (pi = G.job_list; pi; pi = pi->next) {
10228 if (pi->jobid == jobnum) {
10232 bb_error_msg("%u: no such job", jobnum);
10236 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10239 const char *status_string;
10241 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10242 for (job = G.job_list; job; job = job->next) {
10243 if (job->alive_cmds == job->stopped_cmds)
10244 status_string = "Stopped";
10246 status_string = "Running";
10248 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10251 clean_up_last_dead_job();
10253 return EXIT_SUCCESS;
10256 /* built-in 'fg' and 'bg' handler */
10257 static int FAST_FUNC builtin_fg_bg(char **argv)
10262 if (!G_interactive_fd)
10263 return EXIT_FAILURE;
10265 /* If they gave us no args, assume they want the last backgrounded task */
10267 for (pi = G.job_list; pi; pi = pi->next) {
10268 if (pi->jobid == G.last_jobid) {
10272 bb_error_msg("%s: no current job", argv[0]);
10273 return EXIT_FAILURE;
10276 pi = parse_jobspec(argv[1]);
10278 return EXIT_FAILURE;
10280 /* TODO: bash prints a string representation
10281 * of job being foregrounded (like "sleep 1 | cat") */
10282 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10283 /* Put the job into the foreground. */
10284 tcsetpgrp(G_interactive_fd, pi->pgrp);
10287 /* Restart the processes in the job */
10288 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10289 for (i = 0; i < pi->num_cmds; i++) {
10290 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10292 pi->stopped_cmds = 0;
10294 i = kill(- pi->pgrp, SIGCONT);
10296 if (errno == ESRCH) {
10297 delete_finished_job(pi);
10298 return EXIT_SUCCESS;
10300 bb_perror_msg("kill (SIGCONT)");
10303 if (argv[0][0] == 'f') {
10304 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10305 return checkjobs_and_fg_shell(pi);
10307 return EXIT_SUCCESS;
10311 #if ENABLE_HUSH_KILL
10312 static int FAST_FUNC builtin_kill(char **argv)
10316 # if ENABLE_HUSH_JOB
10317 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10325 if (argv[i][0] != '%')
10328 * "kill %N" - job kill
10329 * Converting to pgrp / pid kill
10331 pi = parse_jobspec(argv[i]);
10333 /* Eat bad jobspec */
10337 argv[j - 1] = argv[j];
10344 * In jobs started under job control, we signal
10345 * entire process group by kill -PGRP_ID.
10346 * This happens, f.e., in interactive shell.
10348 * Otherwise, we signal each child via
10349 * kill PID1 PID2 PID3.
10351 * sh -c 'sleep 1|sleep 1 & kill %1'
10352 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10353 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10355 n = G_interactive_fd ? 1 : pi->num_cmds;
10356 dst = alloca(n * sizeof(int)*4);
10358 if (G_interactive_fd)
10359 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10360 else for (j = 0; j < n; j++) {
10361 struct command *cmd = &pi->cmds[j];
10362 /* Skip exited members of the job */
10366 * kill_main has matching code to expect
10367 * leading space. Needed to not confuse
10368 * negative pids with "kill -SIGNAL_NO" syntax
10370 dst += sprintf(dst, " %u", (int)cmd->pid);
10373 } while (argv[++i]);
10377 if (argv[1] || ret == 0) {
10378 ret = run_applet_main(argv, kill_main);
10380 /* else: ret = 1, "kill %bad_jobspec" case */
10385 #if ENABLE_HUSH_WAIT
10386 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10387 #if !ENABLE_HUSH_JOB
10388 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10390 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10397 if (!sigisemptyset(&G.pending_set))
10400 /* waitpid is not interruptible by SA_RESTARTed
10401 * signals which we use. Thus, this ugly dance:
10404 /* Make sure possible SIGCHLD is stored in kernel's
10405 * pending signal mask before we call waitpid.
10406 * Or else we may race with SIGCHLD, lose it,
10407 * and get stuck in sigsuspend...
10409 sigfillset(&oldset); /* block all signals, remember old set */
10410 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10412 if (!sigisemptyset(&G.pending_set)) {
10413 /* Crap! we raced with some signal! */
10417 /*errno = 0; - checkjobs does this */
10418 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10419 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10420 debug_printf_exec("checkjobs:%d\n", ret);
10421 #if ENABLE_HUSH_JOB
10422 if (waitfor_pipe) {
10423 int rcode = job_exited_or_stopped(waitfor_pipe);
10424 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10427 sigprocmask(SIG_SETMASK, &oldset, NULL);
10432 /* if ECHILD, there are no children (ret is -1 or 0) */
10433 /* if ret == 0, no children changed state */
10434 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10435 if (errno == ECHILD || ret) {
10437 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10439 sigprocmask(SIG_SETMASK, &oldset, NULL);
10442 /* Wait for SIGCHLD or any other signal */
10443 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10444 /* Note: sigsuspend invokes signal handler */
10445 sigsuspend(&oldset);
10447 sigprocmask(SIG_SETMASK, &oldset, NULL);
10449 /* So, did we get a signal? */
10450 sig = check_and_run_traps();
10451 if (sig /*&& sig != SIGCHLD - always true */) {
10452 /* Do this for any (non-ignored) signal, not only for ^C */
10456 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10461 static int FAST_FUNC builtin_wait(char **argv)
10466 argv = skip_dash_dash(argv);
10467 if (argv[0] == NULL) {
10468 /* Don't care about wait results */
10469 /* Note 1: must wait until there are no more children */
10470 /* Note 2: must be interruptible */
10472 * $ sleep 3 & sleep 6 & wait
10473 * [1] 30934 sleep 3
10474 * [2] 30935 sleep 6
10477 * $ sleep 3 & sleep 6 & wait
10478 * [1] 30936 sleep 3
10479 * [2] 30937 sleep 6
10481 * ^C <-- after ~4 sec from keyboard
10484 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10488 pid_t pid = bb_strtou(*argv, NULL, 10);
10489 if (errno || pid <= 0) {
10490 #if ENABLE_HUSH_JOB
10491 if (argv[0][0] == '%') {
10492 struct pipe *wait_pipe;
10493 ret = 127; /* bash compat for bad jobspecs */
10494 wait_pipe = parse_jobspec(*argv);
10496 ret = job_exited_or_stopped(wait_pipe);
10498 ret = wait_for_child_or_signal(wait_pipe, 0);
10500 /* waiting on "last dead job" removes it */
10501 clean_up_last_dead_job();
10504 /* else: parse_jobspec() already emitted error msg */
10508 /* mimic bash message */
10509 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10510 ret = EXIT_FAILURE;
10511 continue; /* bash checks all argv[] */
10514 /* Do we have such child? */
10515 ret = waitpid(pid, &status, WNOHANG);
10519 if (errno == ECHILD) {
10520 if (pid == G.last_bg_pid) {
10521 /* "wait $!" but last bg task has already exited. Try:
10522 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10523 * In bash it prints exitcode 0, then 3.
10524 * In dash, it is 127.
10526 ret = G.last_bg_pid_exitcode;
10528 /* Example: "wait 1". mimic bash message */
10529 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10533 bb_perror_msg("wait %s", *argv);
10535 continue; /* bash checks all argv[] */
10538 /* Yes, and it still runs */
10539 ret = wait_for_child_or_signal(NULL, pid);
10541 /* Yes, and it just exited */
10542 process_wait_result(NULL, pid, status);
10543 ret = WEXITSTATUS(status);
10544 if (WIFSIGNALED(status))
10545 ret = 128 + WTERMSIG(status);
10553 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10554 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10557 def = bb_strtou(argv[1], NULL, 10);
10558 if (errno || def < def_min || argv[2]) {
10559 bb_error_msg("%s: bad arguments", argv[0]);
10567 #if ENABLE_HUSH_LOOPS
10568 static int FAST_FUNC builtin_break(char **argv)
10571 if (G.depth_of_loop == 0) {
10572 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10573 /* if we came from builtin_continue(), need to undo "= 1" */
10574 G.flag_break_continue = 0;
10575 return EXIT_SUCCESS; /* bash compat */
10577 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10579 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10580 if (depth == UINT_MAX)
10581 G.flag_break_continue = BC_BREAK;
10582 if (G.depth_of_loop < depth)
10583 G.depth_break_continue = G.depth_of_loop;
10585 return EXIT_SUCCESS;
10588 static int FAST_FUNC builtin_continue(char **argv)
10590 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10591 return builtin_break(argv);
10595 #if ENABLE_HUSH_FUNCTIONS
10596 static int FAST_FUNC builtin_return(char **argv)
10600 if (G_flag_return_in_progress != -1) {
10601 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10602 return EXIT_FAILURE; /* bash compat */
10605 G_flag_return_in_progress = 1;
10608 * out of range: wraps around at 256, does not error out
10609 * non-numeric param:
10610 * f() { false; return qwe; }; f; echo $?
10611 * bash: return: qwe: numeric argument required <== we do this
10612 * 255 <== we also do this
10614 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10619 #if ENABLE_HUSH_TIMES
10620 static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
10622 static const uint8_t times_tbl[] ALIGN1 = {
10623 ' ', offsetof(struct tms, tms_utime),
10624 '\n', offsetof(struct tms, tms_stime),
10625 ' ', offsetof(struct tms, tms_cutime),
10626 '\n', offsetof(struct tms, tms_cstime),
10633 clk_tck = bb_clk_tck();
10638 unsigned sec, frac;
10640 t = *(clock_t *)(((char *) &buf) + p[1]);
10642 frac = t % clk_tck;
10643 printf("%um%u.%03us%c",
10644 sec / 60, sec % 60,
10645 (frac * 1000) / clk_tck,
10650 return EXIT_SUCCESS;
10654 #if ENABLE_HUSH_MEMLEAK
10655 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10660 # ifdef M_TRIM_THRESHOLD
10661 /* Optional. Reduces probability of false positives */
10664 /* Crude attempt to find where "free memory" starts,
10665 * sans fragmentation. */
10667 l = (unsigned long)p;
10670 if (l < (unsigned long)p) l = (unsigned long)p;
10676 struct mallinfo mi = mallinfo();
10677 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10678 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10682 if (!G.memleak_value)
10683 G.memleak_value = l;
10685 l -= G.memleak_value;
10692 /* Exitcode is "how many kilobytes we leaked since 1st call" */