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, getopts, readonly, times:
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 * readonly VAR[=VAL]...: make VARs readonly
61 * readonly [-p]: list all such VARs (-p has no effect in bash)
62 * getopts: getopt() for shells
63 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
64 * fc -l[nr] [BEG] [END]: list range of commands in history
65 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
66 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
69 * redirection of stdout+stderr: &> and >&
70 * reserved words: function select
71 * advanced test: [[ ]]
72 * process substitution: <(list) and >(list)
75 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
76 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
77 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
79 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
80 * This is exactly equivalent to let "EXPR".
81 * $[EXPR]: synonym for $((EXPR))
82 * indirect expansion: ${!VAR}
83 * substring op on @: ${@:n:m}
86 * Some builtins mandated by standards:
87 * newgrp [GRP]: not a builtin in bash but a suid binary
88 * which spawns a new shell with new group ID
89 * In bash, export builtin is special, its arguments are assignments
90 * and therefore expansion of them should be "one-word" expansion:
91 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
93 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
94 * ls: cannot access i=a: No such file or directory
95 * ls: cannot access b: No such file or directory
96 * Note1: same applies to local builtin.
97 * Note2: bash 3.2.33(1) does this only if export word itself
99 * $ export i=`echo 'aaa bbb'`; echo "$i"
101 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
105 //config: bool "hush"
108 //config: hush is a small shell (25k). It handles the normal flow control
109 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
110 //config: case/esac. Redirections, here documents, $((arithmetic))
111 //config: and functions are supported.
113 //config: It will compile and work on no-mmu systems.
115 //config: It does not handle select, aliases, tilde expansion,
116 //config: &>file and >&file redirection of stdout+stderr.
118 //config:config HUSH_BASH_COMPAT
119 //config: bool "bash-compatible extensions"
121 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
123 //config:config HUSH_BRACE_EXPANSION
124 //config: bool "Brace expansion"
126 //config: depends on HUSH_BASH_COMPAT
128 //config: Enable {abc,def} extension.
130 //config:config HUSH_INTERACTIVE
131 //config: bool "Interactive mode"
133 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
135 //config: Enable interactive mode (prompt and command editing).
136 //config: Without this, hush simply reads and executes commands
137 //config: from stdin just like a shell script from a file.
138 //config: No prompt, no PS1/PS2 magic shell variables.
140 //config:config HUSH_SAVEHISTORY
141 //config: bool "Save command history to .hush_history"
143 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
145 //config:config HUSH_JOB
146 //config: bool "Job control"
148 //config: depends on HUSH_INTERACTIVE
150 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
151 //config: command (not entire shell), fg/bg builtins work. Without this option,
152 //config: "cmd &" still works by simply spawning a process and immediately
153 //config: prompting for next command (or executing next command in a script),
154 //config: but no separate process group is formed.
156 //config:config HUSH_TICK
157 //config: bool "Support process substitution"
159 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
161 //config: Enable `command` and $(command).
163 //config:config HUSH_IF
164 //config: bool "Support if/then/elif/else/fi"
166 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
168 //config:config HUSH_LOOPS
169 //config: bool "Support for, while and until loops"
171 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
173 //config:config HUSH_CASE
174 //config: bool "Support case ... esac statement"
176 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
178 //config: Enable case ... esac statement. +400 bytes.
180 //config:config HUSH_FUNCTIONS
181 //config: bool "Support funcname() { commands; } syntax"
183 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
185 //config: Enable support for shell functions. +800 bytes.
187 //config:config HUSH_LOCAL
188 //config: bool "local builtin"
190 //config: depends on HUSH_FUNCTIONS
192 //config: Enable support for local variables in functions.
194 //config:config HUSH_RANDOM_SUPPORT
195 //config: bool "Pseudorandom generator and $RANDOM variable"
197 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
199 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
200 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
202 //config:config HUSH_MODE_X
203 //config: bool "Support 'hush -x' option and 'set -x' command"
205 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
207 //config: This instructs hush to print commands before execution.
208 //config: Adds ~300 bytes.
210 //config:config HUSH_ECHO
211 //config: bool "echo builtin"
213 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
215 //config:config HUSH_PRINTF
216 //config: bool "printf builtin"
218 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
220 //config:config HUSH_TEST
221 //config: bool "test builtin"
223 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
225 //config:config HUSH_HELP
226 //config: bool "help builtin"
228 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
230 //config:config HUSH_EXPORT
231 //config: bool "export builtin"
233 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
235 //config:config HUSH_EXPORT_N
236 //config: bool "Support 'export -n' option"
238 //config: depends on HUSH_EXPORT
240 //config: export -n unexports variables. It is a bash extension.
242 //config:config HUSH_KILL
243 //config: bool "kill builtin (supports kill %jobspec)"
245 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
247 //config:config HUSH_WAIT
248 //config: bool "wait builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config:config HUSH_TRAP
253 //config: bool "trap builtin"
255 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
257 //config:config HUSH_TYPE
258 //config: bool "type builtin"
260 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
262 //config:config HUSH_READ
263 //config: bool "read builtin"
265 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
267 //config:config HUSH_SET
268 //config: bool "set builtin"
270 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
272 //config:config HUSH_UNSET
273 //config: bool "unset builtin"
275 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
277 //config:config HUSH_ULIMIT
278 //config: bool "ulimit builtin"
280 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
282 //config:config HUSH_UMASK
283 //config: bool "umask builtin"
285 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
287 //config:config HUSH_MEMLEAK
288 //config: bool "memleak builtin (debugging)"
290 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
292 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
293 // APPLET_ODDNAME:name main location suid_type help
294 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
295 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
297 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
298 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
299 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
300 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
302 /* -i (interactive) and -s (read stdin) are also accepted,
303 * but currently do nothing, therefore aren't shown in help.
304 * NOMMU-specific options are not meant to be used by users,
305 * therefore we don't show them either.
307 //usage:#define hush_trivial_usage
308 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
309 //usage:#define hush_full_usage "\n\n"
310 //usage: "Unix shell interpreter"
312 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
313 || defined(__APPLE__) \
315 # include <malloc.h> /* for malloc_trim */
318 /* #include <dmalloc.h> */
320 # include <fnmatch.h>
322 #include <sys/utsname.h> /* for setting $HOSTNAME */
324 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
326 #include "shell_common.h"
329 #if ENABLE_HUSH_RANDOM_SUPPORT
332 # define CLEAR_RANDOM_T(rnd) ((void)0)
334 #ifndef F_DUPFD_CLOEXEC
335 # define F_DUPFD_CLOEXEC F_DUPFD
338 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
342 /* So far, all bash compat is controlled by one config option */
343 /* Separate defines document which part of code implements what */
344 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
345 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
346 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
347 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
348 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
352 #define LEAK_HUNTING 0
353 #define BUILD_AS_NOMMU 0
354 /* Enable/disable sanity checks. Ok to enable in production,
355 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
356 * Keeping 1 for now even in released versions.
359 /* Slightly bigger (+200 bytes), but faster hush.
360 * So far it only enables a trick with counting SIGCHLDs and forks,
361 * which allows us to do fewer waitpid's.
362 * (we can detect a case where neither forks were done nor SIGCHLDs happened
363 * and therefore waitpid will return the same result as last time)
365 #define ENABLE_HUSH_FAST 0
366 /* TODO: implement simplified code for users which do not need ${var%...} ops
367 * So far ${var%...} ops are always enabled:
369 #define ENABLE_HUSH_DOLLAR_OPS 1
374 # undef USE_FOR_NOMMU
377 # define USE_FOR_NOMMU(...) __VA_ARGS__
378 # define USE_FOR_MMU(...)
381 #include "NUM_APPLETS.h"
383 /* STANDALONE does not make sense, and won't compile */
384 # undef CONFIG_FEATURE_SH_STANDALONE
385 # undef ENABLE_FEATURE_SH_STANDALONE
386 # undef IF_FEATURE_SH_STANDALONE
387 # undef IF_NOT_FEATURE_SH_STANDALONE
388 # define ENABLE_FEATURE_SH_STANDALONE 0
389 # define IF_FEATURE_SH_STANDALONE(...)
390 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
393 #if !ENABLE_HUSH_INTERACTIVE
394 # undef ENABLE_FEATURE_EDITING
395 # define ENABLE_FEATURE_EDITING 0
396 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
397 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
398 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
399 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
402 /* Do we support ANY keywords? */
403 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
404 # define HAS_KEYWORDS 1
405 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
406 # define IF_HAS_NO_KEYWORDS(...)
408 # define HAS_KEYWORDS 0
409 # define IF_HAS_KEYWORDS(...)
410 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
413 /* If you comment out one of these below, it will be #defined later
414 * to perform debug printfs to stderr: */
415 #define debug_printf(...) do {} while (0)
416 /* Finer-grained debug switches */
417 #define debug_printf_parse(...) do {} while (0)
418 #define debug_print_tree(a, b) do {} while (0)
419 #define debug_printf_exec(...) do {} while (0)
420 #define debug_printf_env(...) do {} while (0)
421 #define debug_printf_jobs(...) do {} while (0)
422 #define debug_printf_expand(...) do {} while (0)
423 #define debug_printf_varexp(...) do {} while (0)
424 #define debug_printf_glob(...) do {} while (0)
425 #define debug_printf_redir(...) do {} while (0)
426 #define debug_printf_list(...) do {} while (0)
427 #define debug_printf_subst(...) do {} while (0)
428 #define debug_printf_clean(...) do {} while (0)
430 #define ERR_PTR ((void*)(long)1)
432 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
434 #define _SPECIAL_VARS_STR "_*@$!?#"
435 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
436 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
437 #if BASH_PATTERN_SUBST
438 /* Support / and // replace ops */
439 /* Note that // is stored as \ in "encoded" string representation */
440 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
441 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
442 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
444 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
445 # define VAR_SUBST_OPS "%#:-=+?"
446 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
449 #define SPECIAL_VAR_SYMBOL 3
453 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
455 /* This supports saving pointers malloced in vfork child,
456 * to be freed in the parent.
459 typedef struct nommu_save_t {
461 struct variable *old_vars;
463 char **argv_from_re_execing;
476 #if ENABLE_HUSH_LOOPS
483 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
488 /* three pseudo-keywords support contrived "case" syntax: */
489 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
490 RES_MATCH , /* "word)" */
491 RES_CASE_BODY, /* "this command is inside CASE" */
498 typedef struct o_string {
500 int length; /* position where data is appended */
503 /* At least some part of the string was inside '' or "",
504 * possibly empty one: word"", wo''rd etc. */
505 smallint has_quoted_part;
506 smallint has_empty_slot;
507 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
510 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
512 /* Protect newly added chars against globbing
513 * by prepending \ to *, ?, [, \ */
514 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
517 MAYBE_ASSIGNMENT = 0,
518 DEFINITELY_ASSIGNMENT = 1,
520 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
523 /* Used for initialization: o_string foo = NULL_O_STRING; */
524 #define NULL_O_STRING { NULL }
526 #ifndef debug_printf_parse
527 static const char *const assignment_flag[] = {
529 "DEFINITELY_ASSIGNMENT",
535 typedef struct in_str {
537 #if ENABLE_HUSH_INTERACTIVE
538 smallint promptmode; /* 0: PS1, 1: PS2 */
545 /* The descrip member of this structure is only used to make
546 * debugging output pretty */
547 static const struct {
549 signed char default_fd;
552 { O_RDONLY, 0, "<" },
553 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
554 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
555 { O_CREAT|O_RDWR, 1, "<>" },
556 { O_RDONLY, 0, "<<" },
557 /* Should not be needed. Bogus default_fd helps in debugging */
558 /* { O_RDONLY, 77, "<<" }, */
561 struct redir_struct {
562 struct redir_struct *next;
563 char *rd_filename; /* filename */
564 int rd_fd; /* fd to redirect */
565 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
567 smallint rd_type; /* (enum redir_type) */
568 /* note: for heredocs, rd_filename contains heredoc delimiter,
569 * and subsequently heredoc itself; and rd_dup is a bitmask:
570 * bit 0: do we need to trim leading tabs?
571 * bit 1: is heredoc quoted (<<'delim' syntax) ?
574 typedef enum redir_type {
576 REDIRECT_OVERWRITE = 1,
579 REDIRECT_HEREDOC = 4,
580 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
583 REDIRFD_SYNTAX_ERR = -2,
584 REDIRFD_TO_FILE = -1,
585 /* otherwise, rd_fd is redirected to rd_dup */
587 HEREDOC_SKIPTABS = 1,
593 pid_t pid; /* 0 if exited */
594 int assignment_cnt; /* how many argv[i] are assignments? */
595 smallint cmd_type; /* CMD_xxx */
597 #define CMD_SUBSHELL 1
599 /* used for "[[ EXPR ]]" */
600 # define CMD_SINGLEWORD_NOGLOB 2
602 #if ENABLE_HUSH_FUNCTIONS
603 # define CMD_FUNCDEF 3
606 smalluint cmd_exitcode;
607 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
610 char *group_as_string;
612 #if ENABLE_HUSH_FUNCTIONS
613 struct function *child_func;
614 /* This field is used to prevent a bug here:
615 * while...do f1() {a;}; f1; f1() {b;}; f1; done
616 * When we execute "f1() {a;}" cmd, we create new function and clear
617 * cmd->group, cmd->group_as_string, cmd->argv[0].
618 * When we execute "f1() {b;}", we notice that f1 exists,
619 * and that its "parent cmd" struct is still "alive",
620 * we put those fields back into cmd->xxx
621 * (struct function has ->parent_cmd ptr to facilitate that).
622 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
623 * Without this trick, loop would execute a;b;b;b;...
624 * instead of correct sequence a;b;a;b;...
625 * When command is freed, it severs the link
626 * (sets ->child_func->parent_cmd to NULL).
629 char **argv; /* command name and arguments */
630 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
631 * and on execution these are substituted with their values.
632 * Substitution can make _several_ words out of one argv[n]!
633 * Example: argv[0]=='.^C*^C.' here: echo .$*.
634 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
636 struct redir_struct *redirects; /* I/O redirections */
638 /* Is there anything in this command at all? */
639 #define IS_NULL_CMD(cmd) \
640 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
644 int num_cmds; /* total number of commands in pipe */
645 int alive_cmds; /* number of commands running (not exited) */
646 int stopped_cmds; /* number of commands alive, but stopped */
648 unsigned jobid; /* job number */
649 pid_t pgrp; /* process group ID for the job */
650 char *cmdtext; /* name of job */
652 struct command *cmds; /* array of commands in pipe */
653 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
654 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
655 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
657 typedef enum pipe_style {
663 /* Is there anything in this pipe at all? */
664 #define IS_NULL_PIPE(pi) \
665 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
667 /* This holds pointers to the various results of parsing */
668 struct parse_context {
669 /* linked list of pipes */
670 struct pipe *list_head;
671 /* last pipe (being constructed right now) */
673 /* last command in pipe (being constructed right now) */
674 struct command *command;
675 /* last redirect in command->redirects list */
676 struct redir_struct *pending_redirect;
682 smallint ctx_inverted; /* "! cmd | cmd" */
684 smallint ctx_dsemicolon; /* ";;" seen */
686 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
688 /* group we are enclosed in:
689 * example: "if pipe1; pipe2; then pipe3; fi"
690 * when we see "if" or "then", we malloc and copy current context,
691 * and make ->stack point to it. then we parse pipeN.
692 * when closing "then" / fi" / whatever is found,
693 * we move list_head into ->stack->command->group,
694 * copy ->stack into current context, and delete ->stack.
695 * (parsing of { list } and ( list ) doesn't use this method)
697 struct parse_context *stack;
701 /* On program start, environ points to initial environment.
702 * putenv adds new pointers into it, unsetenv removes them.
703 * Neither of these (de)allocates the strings.
704 * setenv allocates new strings in malloc space and does putenv,
705 * and thus setenv is unusable (leaky) for shell's purposes */
706 #define setenv(...) setenv_is_leaky_dont_use()
708 struct variable *next;
709 char *varstr; /* points to "name=" portion */
710 #if ENABLE_HUSH_LOCAL
711 unsigned func_nest_level;
713 int max_len; /* if > 0, name is part of initial env; else name is malloced */
714 smallint flg_export; /* putenv should be done on this var */
715 smallint flg_read_only;
723 #if ENABLE_HUSH_FUNCTIONS
725 struct function *next;
727 struct command *parent_cmd;
730 char *body_as_string;
736 /* set -/+o OPT support. (TODO: make it optional)
737 * bash supports the following opts:
748 * interactive-comments on
766 static const char o_opt_strings[] ALIGN1 =
770 #if ENABLE_HUSH_MODE_X
778 #if ENABLE_HUSH_MODE_X
786 struct FILE_list *next;
792 /* "Globals" within this file */
793 /* Sorted roughly by size (smaller offsets == smaller code) */
795 /* interactive_fd != 0 means we are an interactive shell.
796 * If we are, then saved_tty_pgrp can also be != 0, meaning
797 * that controlling tty is available. With saved_tty_pgrp == 0,
798 * job control still works, but terminal signals
799 * (^C, ^Z, ^Y, ^\) won't work at all, and background
800 * process groups can only be created with "cmd &".
801 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
802 * to give tty to the foreground process group,
803 * and will take it back when the group is stopped (^Z)
806 #if ENABLE_HUSH_INTERACTIVE
807 /* 'interactive_fd' is a fd# open to ctty, if we have one
808 * _AND_ if we decided to act interactively */
812 # define G_interactive_fd (G.interactive_fd)
814 # define G_interactive_fd 0
816 #if ENABLE_FEATURE_EDITING
817 line_input_t *line_input_state;
822 #if ENABLE_HUSH_RANDOM_SUPPORT
828 pid_t saved_tty_pgrp;
829 struct pipe *job_list;
830 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
832 # define G_saved_tty_pgrp 0
834 /* How deeply are we in context where "set -e" is ignored */
836 /* "set -e" rules (do we follow them correctly?):
837 * Exit if pipe, list, or compound command exits with a non-zero status.
838 * Shell does not exit if failed command is part of condition in
839 * if/while, part of && or || list except the last command, any command
840 * in a pipe but the last, or if the command's return value is being
841 * inverted with !. If a compound command other than a subshell returns a
842 * non-zero status because a command failed while -e was being ignored, the
843 * shell does not exit. A trap on ERR, if set, is executed before the shell
844 * exits [ERR is a bashism].
846 * If a compound command or function executes in a context where -e is
847 * ignored, none of the commands executed within are affected by the -e
848 * setting. If a compound command or function sets -e while executing in a
849 * context where -e is ignored, that setting does not have any effect until
850 * the compound command or the command containing the function call completes.
853 char o_opt[NUM_OPT_O];
854 #if ENABLE_HUSH_MODE_X
855 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
859 smallint flag_SIGINT;
860 #if ENABLE_HUSH_LOOPS
861 smallint flag_break_continue;
863 #if ENABLE_HUSH_FUNCTIONS
864 /* 0: outside of a function (or sourced file)
865 * -1: inside of a function, ok to use return builtin
866 * 1: return is invoked, skip all till end of func
868 smallint flag_return_in_progress;
869 # define G_flag_return_in_progress (G.flag_return_in_progress)
871 # define G_flag_return_in_progress 0
873 smallint exiting; /* used to prevent EXIT trap recursion */
874 /* These four support $?, $#, and $1 */
875 smalluint last_exitcode;
876 smalluint last_bg_pid_exitcode;
878 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
879 smalluint global_args_malloced;
880 # define G_global_args_malloced (G.global_args_malloced)
882 # define G_global_args_malloced 0
884 /* how many non-NULL argv's we have. NB: $# + 1 */
888 char *argv0_for_re_execing;
890 #if ENABLE_HUSH_LOOPS
891 unsigned depth_break_continue;
892 unsigned depth_of_loop;
896 struct variable *top_var;
897 char **expanded_assignments;
898 #if ENABLE_HUSH_FUNCTIONS
899 struct function *top_func;
900 # if ENABLE_HUSH_LOCAL
901 struct variable **shadowed_vars_pp;
902 unsigned func_nest_level;
905 /* Signal and trap handling */
907 unsigned count_SIGCHLD;
908 unsigned handled_SIGCHLD;
909 smallint we_have_children;
911 struct FILE_list *FILE_list;
912 /* Which signals have non-DFL handler (even with no traps set)?
913 * Set at the start to:
914 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
915 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
916 * The rest is cleared right before execv syscalls.
917 * Other than these two times, never modified.
919 unsigned special_sig_mask;
921 unsigned fatal_sig_mask;
922 # define G_fatal_sig_mask (G.fatal_sig_mask)
924 # define G_fatal_sig_mask 0
927 char **traps; /* char *traps[NSIG] */
928 # define G_traps G.traps
930 # define G_traps ((char**)NULL)
932 sigset_t pending_set;
933 #if ENABLE_HUSH_MEMLEAK
934 unsigned long memleak_value;
940 #if ENABLE_FEATURE_EDITING
941 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
944 #define G (*ptr_to_globals)
945 /* Not #defining name to G.name - this quickly gets unwieldy
946 * (too many defines). Also, I actually prefer to see when a variable
947 * is global, thus "G." prefix is a useful hint */
948 #define INIT_G() do { \
949 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
950 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
951 sigfillset(&G.sa.sa_mask); \
952 G.sa.sa_flags = SA_RESTART; \
956 /* Function prototypes for builtins */
957 static int builtin_cd(char **argv) FAST_FUNC;
959 static int builtin_echo(char **argv) FAST_FUNC;
961 static int builtin_eval(char **argv) FAST_FUNC;
962 static int builtin_exec(char **argv) FAST_FUNC;
963 static int builtin_exit(char **argv) FAST_FUNC;
964 #if ENABLE_HUSH_EXPORT
965 static int builtin_export(char **argv) FAST_FUNC;
968 static int builtin_fg_bg(char **argv) FAST_FUNC;
969 static int builtin_jobs(char **argv) FAST_FUNC;
972 static int builtin_help(char **argv) FAST_FUNC;
974 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
975 static int builtin_history(char **argv) FAST_FUNC;
977 #if ENABLE_HUSH_LOCAL
978 static int builtin_local(char **argv) FAST_FUNC;
980 #if ENABLE_HUSH_MEMLEAK
981 static int builtin_memleak(char **argv) FAST_FUNC;
983 #if ENABLE_HUSH_PRINTF
984 static int builtin_printf(char **argv) FAST_FUNC;
986 static int builtin_pwd(char **argv) FAST_FUNC;
988 static int builtin_read(char **argv) FAST_FUNC;
991 static int builtin_set(char **argv) FAST_FUNC;
993 static int builtin_shift(char **argv) FAST_FUNC;
994 static int builtin_source(char **argv) FAST_FUNC;
995 #if ENABLE_HUSH_TEST || BASH_TEST2
996 static int builtin_test(char **argv) FAST_FUNC;
999 static int builtin_trap(char **argv) FAST_FUNC;
1001 #if ENABLE_HUSH_TYPE
1002 static int builtin_type(char **argv) FAST_FUNC;
1004 static int builtin_true(char **argv) FAST_FUNC;
1005 #if ENABLE_HUSH_UMASK
1006 static int builtin_umask(char **argv) FAST_FUNC;
1008 #if ENABLE_HUSH_UNSET
1009 static int builtin_unset(char **argv) FAST_FUNC;
1011 #if ENABLE_HUSH_KILL
1012 static int builtin_kill(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_WAIT
1015 static int builtin_wait(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_LOOPS
1018 static int builtin_break(char **argv) FAST_FUNC;
1019 static int builtin_continue(char **argv) FAST_FUNC;
1021 #if ENABLE_HUSH_FUNCTIONS
1022 static int builtin_return(char **argv) FAST_FUNC;
1025 /* Table of built-in functions. They can be forked or not, depending on
1026 * context: within pipes, they fork. As simple commands, they do not.
1027 * When used in non-forking context, they can change global variables
1028 * in the parent shell process. If forked, of course they cannot.
1029 * For example, 'unset foo | whatever' will parse and run, but foo will
1030 * still be set at the end. */
1031 struct built_in_command {
1033 int (*b_function)(char **argv) FAST_FUNC;
1034 #if ENABLE_HUSH_HELP
1035 const char *b_descr;
1036 # define BLTIN(cmd, func, help) { cmd, func, help }
1038 # define BLTIN(cmd, func, help) { cmd, func }
1042 static const struct built_in_command bltins1[] = {
1043 BLTIN("." , builtin_source , "Run commands in file"),
1044 BLTIN(":" , builtin_true , NULL),
1046 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1048 #if ENABLE_HUSH_LOOPS
1049 BLTIN("break" , builtin_break , "Exit loop"),
1051 BLTIN("cd" , builtin_cd , "Change directory"),
1052 #if ENABLE_HUSH_LOOPS
1053 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1055 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1056 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1057 BLTIN("exit" , builtin_exit , NULL),
1058 #if ENABLE_HUSH_EXPORT
1059 BLTIN("export" , builtin_export , "Set environment variables"),
1062 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1064 #if ENABLE_HUSH_HELP
1065 BLTIN("help" , builtin_help , NULL),
1067 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1068 BLTIN("history" , builtin_history , "Show history"),
1071 BLTIN("jobs" , builtin_jobs , "List jobs"),
1073 #if ENABLE_HUSH_KILL
1074 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1076 #if ENABLE_HUSH_LOCAL
1077 BLTIN("local" , builtin_local , "Set local variables"),
1079 #if ENABLE_HUSH_MEMLEAK
1080 BLTIN("memleak" , builtin_memleak , NULL),
1082 #if ENABLE_HUSH_READ
1083 BLTIN("read" , builtin_read , "Input into variable"),
1085 #if ENABLE_HUSH_FUNCTIONS
1086 BLTIN("return" , builtin_return , "Return from function"),
1089 BLTIN("set" , builtin_set , "Set positional parameters"),
1091 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1093 BLTIN("source" , builtin_source , NULL),
1095 #if ENABLE_HUSH_TRAP
1096 BLTIN("trap" , builtin_trap , "Trap signals"),
1098 BLTIN("true" , builtin_true , NULL),
1099 #if ENABLE_HUSH_TYPE
1100 BLTIN("type" , builtin_type , "Show command type"),
1102 #if ENABLE_HUSH_ULIMIT
1103 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1105 #if ENABLE_HUSH_UMASK
1106 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1108 #if ENABLE_HUSH_UNSET
1109 BLTIN("unset" , builtin_unset , "Unset variables"),
1111 #if ENABLE_HUSH_WAIT
1112 BLTIN("wait" , builtin_wait , "Wait for process"),
1115 /* These builtins won't be used if we are on NOMMU and need to re-exec
1116 * (it's cheaper to run an external program in this case):
1118 static const struct built_in_command bltins2[] = {
1119 #if ENABLE_HUSH_TEST
1120 BLTIN("[" , builtin_test , NULL),
1123 BLTIN("[[" , builtin_test , NULL),
1125 #if ENABLE_HUSH_ECHO
1126 BLTIN("echo" , builtin_echo , NULL),
1128 #if ENABLE_HUSH_PRINTF
1129 BLTIN("printf" , builtin_printf , NULL),
1131 BLTIN("pwd" , builtin_pwd , NULL),
1132 #if ENABLE_HUSH_TEST
1133 BLTIN("test" , builtin_test , NULL),
1141 /* prevent disasters with G.debug_indent < 0 */
1142 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1143 # define debug_enter() (G.debug_indent++)
1144 # define debug_leave() (G.debug_indent--)
1146 # define indent() ((void)0)
1147 # define debug_enter() ((void)0)
1148 # define debug_leave() ((void)0)
1151 #ifndef debug_printf
1152 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1155 #ifndef debug_printf_parse
1156 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1159 #ifndef debug_printf_exec
1160 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1163 #ifndef debug_printf_env
1164 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_jobs
1168 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1169 # define DEBUG_JOBS 1
1171 # define DEBUG_JOBS 0
1174 #ifndef debug_printf_expand
1175 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1176 # define DEBUG_EXPAND 1
1178 # define DEBUG_EXPAND 0
1181 #ifndef debug_printf_varexp
1182 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1185 #ifndef debug_printf_glob
1186 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1187 # define DEBUG_GLOB 1
1189 # define DEBUG_GLOB 0
1192 #ifndef debug_printf_redir
1193 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1196 #ifndef debug_printf_list
1197 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1200 #ifndef debug_printf_subst
1201 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1204 #ifndef debug_printf_clean
1205 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1206 # define DEBUG_CLEAN 1
1208 # define DEBUG_CLEAN 0
1212 static void debug_print_strings(const char *prefix, char **vv)
1215 fdprintf(2, "%s:\n", prefix);
1217 fdprintf(2, " '%s'\n", *vv++);
1220 # define debug_print_strings(prefix, vv) ((void)0)
1224 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1227 static void *xxmalloc(int lineno, size_t size)
1229 void *ptr = xmalloc((size + 0xff) & ~0xff);
1230 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1233 static void *xxrealloc(int lineno, void *ptr, size_t size)
1235 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1236 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1239 static char *xxstrdup(int lineno, const char *str)
1241 char *ptr = xstrdup(str);
1242 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1245 static void xxfree(void *ptr)
1247 fdprintf(2, "free %p\n", ptr);
1250 # define xmalloc(s) xxmalloc(__LINE__, s)
1251 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1252 # define xstrdup(s) xxstrdup(__LINE__, s)
1253 # define free(p) xxfree(p)
1257 /* Syntax and runtime errors. They always abort scripts.
1258 * In interactive use they usually discard unparsed and/or unexecuted commands
1259 * and return to the prompt.
1260 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1263 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1264 # define syntax_error(lineno, msg) syntax_error(msg)
1265 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1266 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1267 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1268 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1271 static void die_if_script(unsigned lineno, const char *fmt, ...)
1276 bb_error_msg("hush.c:%u", lineno);
1279 bb_verror_msg(fmt, p, NULL);
1281 if (!G_interactive_fd)
1285 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1288 bb_error_msg("syntax error: %s", msg);
1290 bb_error_msg("syntax error");
1293 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1295 bb_error_msg("syntax error at '%s'", msg);
1298 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1300 bb_error_msg("syntax error: unterminated %s", s);
1303 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1305 char msg[2] = { ch, '\0' };
1306 syntax_error_unterm_str(lineno, msg);
1309 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1315 bb_error_msg("hush.c:%u", lineno);
1317 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1321 # undef die_if_script
1322 # undef syntax_error
1323 # undef syntax_error_at
1324 # undef syntax_error_unterm_ch
1325 # undef syntax_error_unterm_str
1326 # undef syntax_error_unexpected_ch
1328 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1329 # define syntax_error(msg) syntax_error(__LINE__, msg)
1330 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1331 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1332 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1333 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1337 #if ENABLE_HUSH_INTERACTIVE
1338 static void cmdedit_update_prompt(void);
1340 # define cmdedit_update_prompt() ((void)0)
1344 /* Utility functions
1346 /* Replace each \x with x in place, return ptr past NUL. */
1347 static char *unbackslash(char *src)
1349 char *dst = src = strchrnul(src, '\\');
1353 if ((*dst++ = *src++) == '\0')
1359 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1380 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1381 v[count1 + count2] = NULL;
1384 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1388 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1390 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1391 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1394 #define add_strings_to_strings(strings, add, need_to_dup) \
1395 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1398 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1399 static char **add_string_to_strings(char **strings, char *add)
1404 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1407 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1409 char **ptr = add_string_to_strings(strings, add);
1410 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1413 #define add_string_to_strings(strings, add) \
1414 xx_add_string_to_strings(__LINE__, strings, add)
1417 static void free_strings(char **strings)
1431 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1435 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1445 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1449 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1455 /* fd was not open? */
1465 /* Manipulating the list of open FILEs */
1466 static FILE *remember_FILE(FILE *fp)
1469 struct FILE_list *n = xmalloc(sizeof(*n));
1470 n->next = G.FILE_list;
1474 close_on_exec_on(n->fd);
1478 static void fclose_and_forget(FILE *fp)
1480 struct FILE_list **pp = &G.FILE_list;
1482 struct FILE_list *cur = *pp;
1483 if (cur->fp == fp) {
1492 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1494 struct FILE_list *fl = G.FILE_list;
1497 /* We use it only on script files, they are all CLOEXEC */
1498 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1499 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1506 static void restore_redirected_FILEs(void)
1508 struct FILE_list *fl = G.FILE_list;
1510 int should_be = fileno(fl->fp);
1511 if (fl->fd != should_be) {
1512 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1513 xmove_fd(fl->fd, should_be);
1519 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1520 static void close_all_FILE_list(void)
1522 struct FILE_list *fl = G.FILE_list;
1524 /* fclose would also free FILE object.
1525 * It is disastrous if we share memory with a vforked parent.
1526 * I'm not sure we never come here after vfork.
1527 * Therefore just close fd, nothing more.
1529 /*fclose(fl->fp); - unsafe */
1537 /* Helpers for setting new $n and restoring them back
1539 typedef struct save_arg_t {
1543 IF_HUSH_SET(smallint sv_g_malloced;)
1546 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1548 sv->sv_argv0 = argv[0];
1549 sv->sv_g_argv = G.global_argv;
1550 sv->sv_g_argc = G.global_argc;
1551 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1553 argv[0] = G.global_argv[0]; /* retain $0 */
1554 G.global_argv = argv;
1555 IF_HUSH_SET(G.global_args_malloced = 0;)
1557 G.global_argc = 1 + string_array_len(argv + 1);
1560 static void restore_G_args(save_arg_t *sv, char **argv)
1563 if (G.global_args_malloced) {
1564 /* someone ran "set -- arg1 arg2 ...", undo */
1565 char **pp = G.global_argv;
1566 while (*++pp) /* note: does not free $0 */
1568 free(G.global_argv);
1571 argv[0] = sv->sv_argv0;
1572 G.global_argv = sv->sv_g_argv;
1573 G.global_argc = sv->sv_g_argc;
1574 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1578 /* Basic theory of signal handling in shell
1579 * ========================================
1580 * This does not describe what hush does, rather, it is current understanding
1581 * what it _should_ do. If it doesn't, it's a bug.
1582 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1584 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1585 * is finished or backgrounded. It is the same in interactive and
1586 * non-interactive shells, and is the same regardless of whether
1587 * a user trap handler is installed or a shell special one is in effect.
1588 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1589 * backgrounds (i.e. stops) or kills all members of currently running
1592 * Wait builtin is interruptible by signals for which user trap is set
1593 * or by SIGINT in interactive shell.
1595 * Trap handlers will execute even within trap handlers. (right?)
1597 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1598 * except for handlers set to '' (empty string).
1600 * If job control is off, backgrounded commands ("cmd &")
1601 * have SIGINT, SIGQUIT set to SIG_IGN.
1603 * Commands which are run in command substitution ("`cmd`")
1604 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1606 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1607 * by the shell from its parent.
1609 * Signals which differ from SIG_DFL action
1610 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1613 * SIGTERM (interactive): ignore
1614 * SIGHUP (interactive):
1615 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1616 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1617 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1618 * that all pipe members are stopped. Try this in bash:
1619 * while :; do :; done - ^Z does not background it
1620 * (while :; do :; done) - ^Z backgrounds it
1621 * SIGINT (interactive): wait for last pipe, ignore the rest
1622 * of the command line, show prompt. NB: ^C does not send SIGINT
1623 * to interactive shell while shell is waiting for a pipe,
1624 * since shell is bg'ed (is not in foreground process group).
1625 * Example 1: this waits 5 sec, but does not execute ls:
1626 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1627 * Example 2: this does not wait and does not execute ls:
1628 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1629 * Example 3: this does not wait 5 sec, but executes ls:
1630 * "sleep 5; ls -l" + press ^C
1631 * Example 4: this does not wait and does not execute ls:
1632 * "sleep 5 & wait; ls -l" + press ^C
1634 * (What happens to signals which are IGN on shell start?)
1635 * (What happens with signal mask on shell start?)
1637 * Old implementation
1638 * ==================
1639 * We use in-kernel pending signal mask to determine which signals were sent.
1640 * We block all signals which we don't want to take action immediately,
1641 * i.e. we block all signals which need to have special handling as described
1642 * above, and all signals which have traps set.
1643 * After each pipe execution, we extract any pending signals via sigtimedwait()
1646 * unsigned special_sig_mask: a mask of such "special" signals
1647 * sigset_t blocked_set: current blocked signal set
1650 * clear bit in blocked_set unless it is also in special_sig_mask
1651 * "trap 'cmd' SIGxxx":
1652 * set bit in blocked_set (even if 'cmd' is '')
1653 * after [v]fork, if we plan to be a shell:
1654 * unblock signals with special interactive handling
1655 * (child shell is not interactive),
1656 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1657 * after [v]fork, if we plan to exec:
1658 * POSIX says fork clears pending signal mask in child - no need to clear it.
1659 * Restore blocked signal set to one inherited by shell just prior to exec.
1661 * Note: as a result, we do not use signal handlers much. The only uses
1662 * are to count SIGCHLDs
1663 * and to restore tty pgrp on signal-induced exit.
1666 * Standard says "When a subshell is entered, traps that are not being ignored
1667 * are set to the default actions". bash interprets it so that traps which
1668 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1670 * Problem: the above approach makes it unwieldy to catch signals while
1671 * we are in read builtin, or while we read commands from stdin:
1672 * masked signals are not visible!
1674 * New implementation
1675 * ==================
1676 * We record each signal we are interested in by installing signal handler
1677 * for them - a bit like emulating kernel pending signal mask in userspace.
1678 * We are interested in: signals which need to have special handling
1679 * as described above, and all signals which have traps set.
1680 * Signals are recorded in pending_set.
1681 * After each pipe execution, we extract any pending signals
1684 * unsigned special_sig_mask: a mask of shell-special signals.
1685 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1686 * char *traps[sig] if trap for sig is set (even if it's '').
1687 * sigset_t pending_set: set of sigs we received.
1690 * if sig is in special_sig_mask, set handler back to:
1691 * record_pending_signo, or to IGN if it's a tty stop signal
1692 * if sig is in fatal_sig_mask, set handler back to sigexit.
1693 * else: set handler back to SIG_DFL
1694 * "trap 'cmd' SIGxxx":
1695 * set handler to record_pending_signo.
1697 * set handler to SIG_IGN.
1698 * after [v]fork, if we plan to be a shell:
1699 * set signals with special interactive handling to SIG_DFL
1700 * (because child shell is not interactive),
1701 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1702 * after [v]fork, if we plan to exec:
1703 * POSIX says fork clears pending signal mask in child - no need to clear it.
1705 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1706 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1709 * Standard says "When a subshell is entered, traps that are not being ignored
1710 * are set to the default actions". bash interprets it so that traps which
1711 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1714 SPECIAL_INTERACTIVE_SIGS = 0
1719 SPECIAL_JOBSTOP_SIGS = 0
1728 static void record_pending_signo(int sig)
1730 sigaddset(&G.pending_set, sig);
1731 #if ENABLE_HUSH_FAST
1732 if (sig == SIGCHLD) {
1734 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1739 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1741 struct sigaction old_sa;
1743 /* We could use signal() to install handlers... almost:
1744 * except that we need to mask ALL signals while handlers run.
1745 * I saw signal nesting in strace, race window isn't small.
1746 * SA_RESTART is also needed, but in Linux, signal()
1747 * sets SA_RESTART too.
1749 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1750 /* sigfillset(&G.sa.sa_mask); - already done */
1751 /* G.sa.sa_flags = SA_RESTART; - already done */
1752 G.sa.sa_handler = handler;
1753 sigaction(sig, &G.sa, &old_sa);
1754 return old_sa.sa_handler;
1757 static void hush_exit(int exitcode) NORETURN;
1759 static void restore_ttypgrp_and__exit(void) NORETURN;
1760 static void restore_ttypgrp_and__exit(void)
1762 /* xfunc has failed! die die die */
1763 /* no EXIT traps, this is an escape hatch! */
1765 hush_exit(xfunc_error_retval);
1770 /* Needed only on some libc:
1771 * It was observed that on exit(), fgetc'ed buffered data
1772 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1773 * With the net effect that even after fork(), not vfork(),
1774 * exit() in NOEXECed applet in "sh SCRIPT":
1775 * noexec_applet_here
1776 * echo END_OF_SCRIPT
1777 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1778 * This makes "echo END_OF_SCRIPT" executed twice.
1779 * Similar problems can be seen with die_if_script() -> xfunc_die()
1780 * and in `cmd` handling.
1781 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1783 static void fflush_and__exit(void) NORETURN;
1784 static void fflush_and__exit(void)
1787 _exit(xfunc_error_retval);
1790 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1791 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1792 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1793 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1795 /* Restores tty foreground process group, and exits.
1796 * May be called as signal handler for fatal signal
1797 * (will resend signal to itself, producing correct exit state)
1798 * or called directly with -EXITCODE.
1799 * We also call it if xfunc is exiting.
1801 static void sigexit(int sig) NORETURN;
1802 static void sigexit(int sig)
1804 /* Careful: we can end up here after [v]fork. Do not restore
1805 * tty pgrp then, only top-level shell process does that */
1806 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1807 /* Disable all signals: job control, SIGPIPE, etc.
1808 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1810 sigprocmask_allsigs(SIG_BLOCK);
1811 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1814 /* Not a signal, just exit */
1818 kill_myself_with_sig(sig); /* does not return */
1822 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1823 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1827 static sighandler_t pick_sighandler(unsigned sig)
1829 sighandler_t handler = SIG_DFL;
1830 if (sig < sizeof(unsigned)*8) {
1831 unsigned sigmask = (1 << sig);
1835 if (G_fatal_sig_mask & sigmask)
1839 /* sig has special handling? */
1840 if (G.special_sig_mask & sigmask) {
1841 handler = record_pending_signo;
1842 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1843 * in order to ignore them: they will be raised
1844 * in an endless loop when we try to do some
1845 * terminal ioctls! We do have to _ignore_ these.
1847 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1854 /* Restores tty foreground process group, and exits. */
1855 static void hush_exit(int exitcode)
1857 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1858 save_history(G.line_input_state);
1862 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1864 /* argv[0] is unused */
1865 argv[1] = G_traps[0];
1867 G.exiting = 1; /* prevent EXIT trap recursion */
1868 /* Note: G_traps[0] is not cleared!
1869 * "trap" will still show it, if executed
1874 #if ENABLE_FEATURE_CLEAN_UP
1876 struct variable *cur_var;
1877 if (G.cwd != bb_msg_unknown)
1879 cur_var = G.top_var;
1881 struct variable *tmp = cur_var;
1882 if (!cur_var->max_len)
1883 free(cur_var->varstr);
1884 cur_var = cur_var->next;
1892 sigexit(- (exitcode & 0xff));
1899 //TODO: return a mask of ALL handled sigs?
1900 static int check_and_run_traps(void)
1907 if (sigisemptyset(&G.pending_set))
1912 if (sigismember(&G.pending_set, sig)) {
1913 sigdelset(&G.pending_set, sig);
1916 } while (sig < NSIG);
1919 if (G_traps && G_traps[sig]) {
1920 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1921 if (G_traps[sig][0]) {
1922 /* We have user-defined handler */
1923 smalluint save_rcode;
1925 /* argv[0] is unused */
1926 argv[1] = G_traps[sig];
1928 save_rcode = G.last_exitcode;
1930 //FIXME: shouldn't it be set to 128 + sig instead?
1931 G.last_exitcode = save_rcode;
1933 } /* else: "" trap, ignoring signal */
1936 /* not a trap: special action */
1939 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1946 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1947 /* bash is observed to signal whole process groups,
1948 * not individual processes */
1949 for (job = G.job_list; job; job = job->next) {
1952 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1953 if (kill(- job->pgrp, SIGHUP) == 0)
1954 kill(- job->pgrp, SIGCONT);
1959 #if ENABLE_HUSH_FAST
1961 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1963 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1965 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1966 * This simplifies wait builtin a bit.
1970 default: /* ignored: */
1971 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1972 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1974 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1975 * Example: wait is not interrupted by TERM
1976 * in interactive shell, because TERM is ignored.
1985 static const char *get_cwd(int force)
1987 if (force || G.cwd == NULL) {
1988 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1989 * we must not try to free(bb_msg_unknown) */
1990 if (G.cwd == bb_msg_unknown)
1992 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1994 G.cwd = bb_msg_unknown;
2001 * Shell and environment variable support
2003 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2005 struct variable **pp;
2006 struct variable *cur;
2009 while ((cur = *pp) != NULL) {
2010 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2017 static const char* FAST_FUNC get_local_var_value(const char *name)
2019 struct variable **vpp;
2020 unsigned len = strlen(name);
2022 if (G.expanded_assignments) {
2023 char **cpp = G.expanded_assignments;
2026 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2027 return cp + len + 1;
2032 vpp = get_ptr_to_local_var(name, len);
2034 return (*vpp)->varstr + len + 1;
2036 if (strcmp(name, "PPID") == 0)
2037 return utoa(G.root_ppid);
2038 // bash compat: UID? EUID?
2039 #if ENABLE_HUSH_RANDOM_SUPPORT
2040 if (strcmp(name, "RANDOM") == 0)
2041 return utoa(next_random(&G.random_gen));
2046 /* str holds "NAME=VAL" and is expected to be malloced.
2047 * We take ownership of it.
2049 * 0: do not change export flag
2050 * (if creating new variable, flag will be 0)
2051 * 1: set export flag and putenv the variable
2052 * -1: clear export flag and unsetenv the variable
2053 * flg_read_only is set only when we handle -R var=val
2055 #if !BB_MMU && ENABLE_HUSH_LOCAL
2056 /* all params are used */
2057 #elif BB_MMU && ENABLE_HUSH_LOCAL
2058 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2059 set_local_var(str, flg_export, local_lvl)
2060 #elif BB_MMU && !ENABLE_HUSH_LOCAL
2061 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2062 set_local_var(str, flg_export)
2063 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2064 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2065 set_local_var(str, flg_export, flg_read_only)
2067 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2069 struct variable **var_pp;
2070 struct variable *cur;
2071 char *free_me = NULL;
2075 eq_sign = strchr(str, '=');
2076 if (!eq_sign) { /* not expected to ever happen? */
2081 name_len = eq_sign - str + 1; /* including '=' */
2082 var_pp = &G.top_var;
2083 while ((cur = *var_pp) != NULL) {
2084 if (strncmp(cur->varstr, str, name_len) != 0) {
2085 var_pp = &cur->next;
2089 /* We found an existing var with this name */
2090 if (cur->flg_read_only) {
2094 bb_error_msg("%s: readonly variable", str);
2098 if (flg_export == -1) { // "&& cur->flg_export" ?
2099 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2104 #if ENABLE_HUSH_LOCAL
2105 if (cur->func_nest_level < local_lvl) {
2106 /* New variable is declared as local,
2107 * and existing one is global, or local
2108 * from enclosing function.
2109 * Remove and save old one: */
2110 *var_pp = cur->next;
2111 cur->next = *G.shadowed_vars_pp;
2112 *G.shadowed_vars_pp = cur;
2113 /* bash 3.2.33(1) and exported vars:
2115 * # f() { local z=a; env | grep ^z; }
2121 if (cur->flg_export)
2126 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2131 if (cur->max_len != 0) {
2132 if (cur->max_len >= strlen(str)) {
2133 /* This one is from startup env, reuse space */
2134 strcpy(cur->varstr, str);
2139 goto set_str_and_exp;
2141 /* max_len == 0 signifies "malloced" var, which we can
2142 * (and have to) free. But we can't free(cur->varstr) here:
2143 * if cur->flg_export is 1, it is in the environment.
2144 * We should either unsetenv+free, or wait until putenv,
2145 * then putenv(new)+free(old).
2147 free_me = cur->varstr;
2148 goto set_str_and_exp;
2151 /* Not found - create new variable struct */
2152 cur = xzalloc(sizeof(*cur));
2153 #if ENABLE_HUSH_LOCAL
2154 cur->func_nest_level = local_lvl;
2156 cur->next = *var_pp;
2162 cur->flg_read_only = flg_read_only;
2165 if (flg_export == 1)
2166 cur->flg_export = 1;
2167 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2168 cmdedit_update_prompt();
2169 if (cur->flg_export) {
2170 if (flg_export == -1) {
2171 cur->flg_export = 0;
2172 /* unsetenv was already done */
2175 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2176 i = putenv(cur->varstr);
2177 /* only now we can free old exported malloced string */
2186 /* Used at startup and after each cd */
2187 static void set_pwd_var(int exp)
2189 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2190 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2193 static int unset_local_var_len(const char *name, int name_len)
2195 struct variable *cur;
2196 struct variable **var_pp;
2199 return EXIT_SUCCESS;
2200 var_pp = &G.top_var;
2201 while ((cur = *var_pp) != NULL) {
2202 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2203 if (cur->flg_read_only) {
2204 bb_error_msg("%s: readonly variable", name);
2205 return EXIT_FAILURE;
2207 *var_pp = cur->next;
2208 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2209 bb_unsetenv(cur->varstr);
2210 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2211 cmdedit_update_prompt();
2215 return EXIT_SUCCESS;
2217 var_pp = &cur->next;
2219 return EXIT_SUCCESS;
2222 #if ENABLE_HUSH_UNSET
2223 static int unset_local_var(const char *name)
2225 return unset_local_var_len(name, strlen(name));
2229 static void unset_vars(char **strings)
2237 const char *eq = strchrnul(*v, '=');
2238 unset_local_var_len(*v, (int)(eq - *v));
2244 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2245 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2247 char *var = xasprintf("%s=%s", name, val);
2248 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2254 * Helpers for "var1=val1 var2=val2 cmd" feature
2256 static void add_vars(struct variable *var)
2258 struct variable *next;
2262 var->next = G.top_var;
2264 if (var->flg_export) {
2265 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2266 putenv(var->varstr);
2268 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2274 static struct variable *set_vars_and_save_old(char **strings)
2277 struct variable *old = NULL;
2283 struct variable *var_p;
2284 struct variable **var_pp;
2287 eq = strchr(*s, '=');
2289 var_pp = get_ptr_to_local_var(*s, eq - *s);
2291 /* Remove variable from global linked list */
2293 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2294 *var_pp = var_p->next;
2295 /* Add it to returned list */
2299 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2310 static void reinit_unicode_for_hush(void)
2312 /* Unicode support should be activated even if LANG is set
2313 * _during_ shell execution, not only if it was set when
2314 * shell was started. Therefore, re-check LANG every time:
2316 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2317 || ENABLE_UNICODE_USING_LOCALE
2319 const char *s = get_local_var_value("LC_ALL");
2320 if (!s) s = get_local_var_value("LC_CTYPE");
2321 if (!s) s = get_local_var_value("LANG");
2327 * in_str support (strings, and "strings" read from files).
2330 #if ENABLE_HUSH_INTERACTIVE
2331 /* To test correct lineedit/interactive behavior, type from command line:
2337 * It exercises a lot of corner cases.
2339 static void cmdedit_update_prompt(void)
2341 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2342 G.PS1 = get_local_var_value("PS1");
2345 G.PS2 = get_local_var_value("PS2");
2352 static const char *setup_prompt_string(int promptmode)
2354 const char *prompt_str;
2355 debug_printf("setup_prompt_string %d ", promptmode);
2356 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2357 /* Set up the prompt */
2358 if (promptmode == 0) { /* PS1 */
2360 /* bash uses $PWD value, even if it is set by user.
2361 * It uses current dir only if PWD is unset.
2362 * We always use current dir. */
2363 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2368 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2369 debug_printf("prompt_str '%s'\n", prompt_str);
2372 static int get_user_input(struct in_str *i)
2375 const char *prompt_str;
2377 prompt_str = setup_prompt_string(i->promptmode);
2378 # if ENABLE_FEATURE_EDITING
2380 reinit_unicode_for_hush();
2381 if (G.flag_SIGINT) {
2382 /* There was ^C'ed, make it look prettier: */
2386 /* buglet: SIGINT will not make new prompt to appear _at once_,
2387 * only after <Enter>. (^C works immediately) */
2388 r = read_line_input(G.line_input_state, prompt_str,
2389 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2392 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2394 write(STDOUT_FILENO, "^C", 2);
2397 check_and_run_traps();
2398 if (r != 0 && !G.flag_SIGINT)
2400 /* ^C or SIGINT: repeat */
2401 G.last_exitcode = 128 + SIGINT;
2404 /* EOF/error detected */
2406 i->peek_buf[0] = r = EOF;
2409 i->p = G.user_input_buf;
2410 return (unsigned char)*i->p++;
2414 if (i->last_char == '\0' || i->last_char == '\n') {
2415 /* Why check_and_run_traps here? Try this interactively:
2416 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2417 * $ <[enter], repeatedly...>
2418 * Without check_and_run_traps, handler never runs.
2420 check_and_run_traps();
2421 fputs(prompt_str, stdout);
2424 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2426 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2427 * no ^C masking happens during fgetc, no special code for ^C:
2428 * it generates SIGINT as usual.
2430 check_and_run_traps();
2432 G.last_exitcode = 128 + SIGINT;
2439 /* This is the magic location that prints prompts
2440 * and gets data back from the user */
2441 static int fgetc_interactive(struct in_str *i)
2444 /* If it's interactive stdin, get new line. */
2445 if (G_interactive_fd && i->file == stdin) {
2446 /* Returns first char (or EOF), the rest is in i->p[] */
2447 ch = get_user_input(i);
2448 i->promptmode = 1; /* PS2 */
2450 /* Not stdin: script file, sourced file, etc */
2451 do ch = fgetc(i->file); while (ch == '\0');
2456 static inline int fgetc_interactive(struct in_str *i)
2459 do ch = fgetc(i->file); while (ch == '\0');
2462 #endif /* INTERACTIVE */
2464 static int i_getch(struct in_str *i)
2469 /* string-based in_str */
2470 ch = (unsigned char)*i->p;
2479 /* FILE-based in_str */
2481 #if ENABLE_FEATURE_EDITING
2482 /* This can be stdin, check line editing char[] buffer */
2483 if (i->p && *i->p != '\0') {
2484 ch = (unsigned char)*i->p++;
2488 /* peek_buf[] is an int array, not char. Can contain EOF. */
2489 ch = i->peek_buf[0];
2491 int ch2 = i->peek_buf[1];
2492 i->peek_buf[0] = ch2;
2493 if (ch2 == 0) /* very likely, avoid redundant write */
2499 ch = fgetc_interactive(i);
2501 debug_printf("file_get: got '%c' %d\n", ch, ch);
2506 static int i_peek(struct in_str *i)
2511 /* string-based in_str */
2512 /* Doesn't report EOF on NUL. None of the callers care. */
2513 return (unsigned char)*i->p;
2516 /* FILE-based in_str */
2518 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2519 /* This can be stdin, check line editing char[] buffer */
2520 if (i->p && *i->p != '\0')
2521 return (unsigned char)*i->p;
2523 /* peek_buf[] is an int array, not char. Can contain EOF. */
2524 ch = i->peek_buf[0];
2528 /* Need to get a new char */
2529 ch = fgetc_interactive(i);
2530 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2532 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2533 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2539 i->peek_buf[0] = ch;
2540 /*i->peek_buf[1] = 0; - already is */
2544 /* Only ever called if i_peek() was called, and did not return EOF.
2545 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2546 * not end-of-line. Therefore we never need to read a new editing line here.
2548 static int i_peek2(struct in_str *i)
2552 /* There are two cases when i->p[] buffer exists.
2553 * (1) it's a string in_str.
2554 * (2) It's a file, and we have a saved line editing buffer.
2555 * In both cases, we know that i->p[0] exists and not NUL, and
2556 * the peek2 result is in i->p[1].
2559 return (unsigned char)i->p[1];
2561 /* Now we know it is a file-based in_str. */
2563 /* peek_buf[] is an int array, not char. Can contain EOF. */
2564 /* Is there 2nd char? */
2565 ch = i->peek_buf[1];
2567 /* We did not read it yet, get it now */
2568 do ch = fgetc(i->file); while (ch == '\0');
2569 i->peek_buf[1] = ch;
2572 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2576 static void setup_file_in_str(struct in_str *i, FILE *f)
2578 memset(i, 0, sizeof(*i));
2579 /* i->promptmode = 0; - PS1 (memset did it) */
2584 static void setup_string_in_str(struct in_str *i, const char *s)
2586 memset(i, 0, sizeof(*i));
2587 /* i->promptmode = 0; - PS1 (memset did it) */
2588 /*i->file = NULL */;
2596 #define B_CHUNK (32 * sizeof(char*))
2598 static void o_reset_to_empty_unquoted(o_string *o)
2601 o->has_quoted_part = 0;
2606 static void o_free(o_string *o)
2609 memset(o, 0, sizeof(*o));
2612 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2617 static void o_grow_by(o_string *o, int len)
2619 if (o->length + len > o->maxlen) {
2620 o->maxlen += (2 * len) | (B_CHUNK-1);
2621 o->data = xrealloc(o->data, 1 + o->maxlen);
2625 static void o_addchr(o_string *o, int ch)
2627 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2628 if (o->length < o->maxlen) {
2629 /* likely. avoid o_grow_by() call */
2631 o->data[o->length] = ch;
2633 o->data[o->length] = '\0';
2641 /* Valid only if we know o_string is not empty */
2642 static void o_delchr(o_string *o)
2645 o->data[o->length] = '\0';
2649 static void o_addblock(o_string *o, const char *str, int len)
2652 memcpy(&o->data[o->length], str, len);
2654 o->data[o->length] = '\0';
2657 static void o_addstr(o_string *o, const char *str)
2659 o_addblock(o, str, strlen(str));
2663 static void nommu_addchr(o_string *o, int ch)
2669 # define nommu_addchr(o, str) ((void)0)
2672 static void o_addstr_with_NUL(o_string *o, const char *str)
2674 o_addblock(o, str, strlen(str) + 1);
2678 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2679 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2680 * Apparently, on unquoted $v bash still does globbing
2681 * ("v='*.txt'; echo $v" prints all .txt files),
2682 * but NOT brace expansion! Thus, there should be TWO independent
2683 * quoting mechanisms on $v expansion side: one protects
2684 * $v from brace expansion, and other additionally protects "$v" against globbing.
2685 * We have only second one.
2688 #if ENABLE_HUSH_BRACE_EXPANSION
2689 # define MAYBE_BRACES "{}"
2691 # define MAYBE_BRACES ""
2694 /* My analysis of quoting semantics tells me that state information
2695 * is associated with a destination, not a source.
2697 static void o_addqchr(o_string *o, int ch)
2700 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2705 o->data[o->length] = '\\';
2708 o->data[o->length] = ch;
2710 o->data[o->length] = '\0';
2713 static void o_addQchr(o_string *o, int ch)
2716 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2717 && strchr("*?[\\" MAYBE_BRACES, ch)
2720 o->data[o->length] = '\\';
2724 o->data[o->length] = ch;
2726 o->data[o->length] = '\0';
2729 static void o_addqblock(o_string *o, const char *str, int len)
2734 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2735 if (ordinary_cnt > len) /* paranoia */
2737 o_addblock(o, str, ordinary_cnt);
2738 if (ordinary_cnt == len)
2739 return; /* NUL is already added by o_addblock */
2740 str += ordinary_cnt;
2741 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2745 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2747 o->data[o->length] = '\\';
2751 o->data[o->length] = ch;
2754 o->data[o->length] = '\0';
2757 static void o_addQblock(o_string *o, const char *str, int len)
2759 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2760 o_addblock(o, str, len);
2763 o_addqblock(o, str, len);
2766 static void o_addQstr(o_string *o, const char *str)
2768 o_addQblock(o, str, strlen(str));
2771 /* A special kind of o_string for $VAR and `cmd` expansion.
2772 * It contains char* list[] at the beginning, which is grown in 16 element
2773 * increments. Actual string data starts at the next multiple of 16 * (char*).
2774 * list[i] contains an INDEX (int!) into this string data.
2775 * It means that if list[] needs to grow, data needs to be moved higher up
2776 * but list[i]'s need not be modified.
2777 * NB: remembering how many list[i]'s you have there is crucial.
2778 * o_finalize_list() operation post-processes this structure - calculates
2779 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2781 #if DEBUG_EXPAND || DEBUG_GLOB
2782 static void debug_print_list(const char *prefix, o_string *o, int n)
2784 char **list = (char**)o->data;
2785 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2789 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2790 prefix, list, n, string_start, o->length, o->maxlen,
2791 !!(o->o_expflags & EXP_FLAG_GLOB),
2793 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2796 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2797 o->data + (int)(uintptr_t)list[i] + string_start,
2798 o->data + (int)(uintptr_t)list[i] + string_start);
2802 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2804 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2808 # define debug_print_list(prefix, o, n) ((void)0)
2811 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2812 * in list[n] so that it points past last stored byte so far.
2813 * It returns n+1. */
2814 static int o_save_ptr_helper(o_string *o, int n)
2816 char **list = (char**)o->data;
2820 if (!o->has_empty_slot) {
2821 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2822 string_len = o->length - string_start;
2823 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2824 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2825 /* list[n] points to string_start, make space for 16 more pointers */
2826 o->maxlen += 0x10 * sizeof(list[0]);
2827 o->data = xrealloc(o->data, o->maxlen + 1);
2828 list = (char**)o->data;
2829 memmove(list + n + 0x10, list + n, string_len);
2830 o->length += 0x10 * sizeof(list[0]);
2832 debug_printf_list("list[%d]=%d string_start=%d\n",
2833 n, string_len, string_start);
2836 /* We have empty slot at list[n], reuse without growth */
2837 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2838 string_len = o->length - string_start;
2839 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2840 n, string_len, string_start);
2841 o->has_empty_slot = 0;
2843 o->has_quoted_part = 0;
2844 list[n] = (char*)(uintptr_t)string_len;
2848 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2849 static int o_get_last_ptr(o_string *o, int n)
2851 char **list = (char**)o->data;
2852 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2854 return ((int)(uintptr_t)list[n-1]) + string_start;
2857 #if ENABLE_HUSH_BRACE_EXPANSION
2858 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2859 * first, it processes even {a} (no commas), second,
2860 * I didn't manage to make it return strings when they don't match
2861 * existing files. Need to re-implement it.
2865 static int glob_needed(const char *s)
2874 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2880 /* Return pointer to next closing brace or to comma */
2881 static const char *next_brace_sub(const char *cp)
2885 while (*cp != '\0') {
2892 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2898 return *cp != '\0' ? cp : NULL;
2900 /* Recursive brace globber. Note: may garble pattern[]. */
2901 static int glob_brace(char *pattern, o_string *o, int n)
2903 char *new_pattern_buf;
2910 debug_printf_glob("glob_brace('%s')\n", pattern);
2916 if (*begin == '{') {
2917 /* Find the first sub-pattern and at the same time
2918 * find the rest after the closing brace */
2919 next = next_brace_sub(begin);
2921 /* An illegal expression */
2925 /* "{abc}" with no commas - illegal
2926 * brace expr, disregard and skip it */
2932 if (*begin == '\\' && begin[1] != '\0')
2936 debug_printf_glob("begin:%s\n", begin);
2937 debug_printf_glob("next:%s\n", next);
2939 /* Now find the end of the whole brace expression */
2941 while (*rest != '}') {
2942 rest = next_brace_sub(rest);
2944 /* An illegal expression */
2947 debug_printf_glob("rest:%s\n", rest);
2949 rest_len = strlen(++rest) + 1;
2951 /* We are sure the brace expression is well-formed */
2953 /* Allocate working buffer large enough for our work */
2954 new_pattern_buf = xmalloc(strlen(pattern));
2956 /* We have a brace expression. BEGIN points to the opening {,
2957 * NEXT points past the terminator of the first element, and REST
2958 * points past the final }. We will accumulate result names from
2959 * recursive runs for each brace alternative in the buffer using
2964 /* Construct the new glob expression */
2967 mempcpy(new_pattern_buf,
2968 /* We know the prefix for all sub-patterns */
2969 pattern, begin - pattern),
2973 /* Note: glob_brace() may garble new_pattern_buf[].
2974 * That's why we re-copy prefix every time (1st memcpy above).
2976 n = glob_brace(new_pattern_buf, o, n);
2978 /* We saw the last entry */
2982 next = next_brace_sub(next);
2984 free(new_pattern_buf);
2992 memset(&globdata, 0, sizeof(globdata));
2993 gr = glob(pattern, 0, NULL, &globdata);
2994 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2996 if (gr == GLOB_NOMATCH) {
2997 globfree(&globdata);
2998 /* NB: garbles parameter */
2999 unbackslash(pattern);
3000 o_addstr_with_NUL(o, pattern);
3001 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3002 return o_save_ptr_helper(o, n);
3004 if (gr == GLOB_NOSPACE)
3005 bb_error_msg_and_die(bb_msg_memory_exhausted);
3006 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3007 * but we didn't specify it. Paranoia again. */
3008 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3010 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3011 char **argv = globdata.gl_pathv;
3013 o_addstr_with_NUL(o, *argv);
3014 n = o_save_ptr_helper(o, n);
3020 globfree(&globdata);
3024 /* Performs globbing on last list[],
3025 * saving each result as a new list[].
3027 static int perform_glob(o_string *o, int n)
3029 char *pattern, *copy;
3031 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3033 return o_save_ptr_helper(o, n);
3034 pattern = o->data + o_get_last_ptr(o, n);
3035 debug_printf_glob("glob pattern '%s'\n", pattern);
3036 if (!glob_needed(pattern)) {
3037 /* unbackslash last string in o in place, fix length */
3038 o->length = unbackslash(pattern) - o->data;
3039 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3040 return o_save_ptr_helper(o, n);
3043 copy = xstrdup(pattern);
3044 /* "forget" pattern in o */
3045 o->length = pattern - o->data;
3046 n = glob_brace(copy, o, n);
3049 debug_print_list("perform_glob returning", o, n);
3053 #else /* !HUSH_BRACE_EXPANSION */
3056 static int glob_needed(const char *s)
3065 if (*s == '*' || *s == '[' || *s == '?')
3071 /* Performs globbing on last list[],
3072 * saving each result as a new list[].
3074 static int perform_glob(o_string *o, int n)
3080 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3082 return o_save_ptr_helper(o, n);
3083 pattern = o->data + o_get_last_ptr(o, n);
3084 debug_printf_glob("glob pattern '%s'\n", pattern);
3085 if (!glob_needed(pattern)) {
3087 /* unbackslash last string in o in place, fix length */
3088 o->length = unbackslash(pattern) - o->data;
3089 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3090 return o_save_ptr_helper(o, n);
3093 memset(&globdata, 0, sizeof(globdata));
3094 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3095 * If we glob "*.\*" and don't find anything, we need
3096 * to fall back to using literal "*.*", but GLOB_NOCHECK
3097 * will return "*.\*"!
3099 gr = glob(pattern, 0, NULL, &globdata);
3100 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3102 if (gr == GLOB_NOMATCH) {
3103 globfree(&globdata);
3106 if (gr == GLOB_NOSPACE)
3107 bb_error_msg_and_die(bb_msg_memory_exhausted);
3108 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3109 * but we didn't specify it. Paranoia again. */
3110 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3112 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3113 char **argv = globdata.gl_pathv;
3114 /* "forget" pattern in o */
3115 o->length = pattern - o->data;
3117 o_addstr_with_NUL(o, *argv);
3118 n = o_save_ptr_helper(o, n);
3124 globfree(&globdata);
3126 debug_print_list("perform_glob returning", o, n);
3130 #endif /* !HUSH_BRACE_EXPANSION */
3132 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3133 * Otherwise, just finish current list[] and start new */
3134 static int o_save_ptr(o_string *o, int n)
3136 if (o->o_expflags & EXP_FLAG_GLOB) {
3137 /* If o->has_empty_slot, list[n] was already globbed
3138 * (if it was requested back then when it was filled)
3139 * so don't do that again! */
3140 if (!o->has_empty_slot)
3141 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3143 return o_save_ptr_helper(o, n);
3146 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3147 static char **o_finalize_list(o_string *o, int n)
3152 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3154 debug_print_list("finalized", o, n);
3155 debug_printf_expand("finalized n:%d\n", n);
3156 list = (char**)o->data;
3157 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3161 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3166 static void free_pipe_list(struct pipe *pi);
3168 /* Returns pi->next - next pipe in the list */
3169 static struct pipe *free_pipe(struct pipe *pi)
3174 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3175 for (i = 0; i < pi->num_cmds; i++) {
3176 struct command *command;
3177 struct redir_struct *r, *rnext;
3179 command = &pi->cmds[i];
3180 debug_printf_clean(" command %d:\n", i);
3181 if (command->argv) {
3185 for (a = 0, p = command->argv; *p; a++, p++) {
3186 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3189 free_strings(command->argv);
3190 //command->argv = NULL;
3192 /* not "else if": on syntax error, we may have both! */
3193 if (command->group) {
3194 debug_printf_clean(" begin group (cmd_type:%d)\n",
3196 free_pipe_list(command->group);
3197 debug_printf_clean(" end group\n");
3198 //command->group = NULL;
3200 /* else is crucial here.
3201 * If group != NULL, child_func is meaningless */
3202 #if ENABLE_HUSH_FUNCTIONS
3203 else if (command->child_func) {
3204 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3205 command->child_func->parent_cmd = NULL;
3209 free(command->group_as_string);
3210 //command->group_as_string = NULL;
3212 for (r = command->redirects; r; r = rnext) {
3213 debug_printf_clean(" redirect %d%s",
3214 r->rd_fd, redir_table[r->rd_type].descrip);
3215 /* guard against the case >$FOO, where foo is unset or blank */
3216 if (r->rd_filename) {
3217 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3218 free(r->rd_filename);
3219 //r->rd_filename = NULL;
3221 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3225 //command->redirects = NULL;
3227 free(pi->cmds); /* children are an array, they get freed all at once */
3231 //pi->cmdtext = NULL;
3239 static void free_pipe_list(struct pipe *pi)
3243 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3245 debug_printf_clean("pipe followup code %d\n", pi->followup);
3251 /*** Parsing routines ***/
3253 #ifndef debug_print_tree
3254 static void debug_print_tree(struct pipe *pi, int lvl)
3256 static const char *const PIPE[] = {
3262 static const char *RES[] = {
3263 [RES_NONE ] = "NONE" ,
3266 [RES_THEN ] = "THEN" ,
3267 [RES_ELIF ] = "ELIF" ,
3268 [RES_ELSE ] = "ELSE" ,
3271 # if ENABLE_HUSH_LOOPS
3272 [RES_FOR ] = "FOR" ,
3273 [RES_WHILE] = "WHILE",
3274 [RES_UNTIL] = "UNTIL",
3276 [RES_DONE ] = "DONE" ,
3278 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3281 # if ENABLE_HUSH_CASE
3282 [RES_CASE ] = "CASE" ,
3283 [RES_CASE_IN ] = "CASE_IN" ,
3284 [RES_MATCH] = "MATCH",
3285 [RES_CASE_BODY] = "CASE_BODY",
3286 [RES_ESAC ] = "ESAC" ,
3288 [RES_XXXX ] = "XXXX" ,
3289 [RES_SNTX ] = "SNTX" ,
3291 static const char *const CMDTYPE[] = {
3295 # if ENABLE_HUSH_FUNCTIONS
3304 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3305 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3307 while (prn < pi->num_cmds) {
3308 struct command *command = &pi->cmds[prn];
3309 char **argv = command->argv;
3311 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3313 command->assignment_cnt);
3314 if (command->group) {
3315 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3316 CMDTYPE[command->cmd_type],
3319 , " group_as_string:", command->group_as_string
3324 debug_print_tree(command->group, lvl+1);
3328 if (argv) while (*argv) {
3329 fdprintf(2, " '%s'", *argv);
3339 #endif /* debug_print_tree */
3341 static struct pipe *new_pipe(void)
3344 pi = xzalloc(sizeof(struct pipe));
3345 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3349 /* Command (member of a pipe) is complete, or we start a new pipe
3350 * if ctx->command is NULL.
3351 * No errors possible here.
3353 static int done_command(struct parse_context *ctx)
3355 /* The command is really already in the pipe structure, so
3356 * advance the pipe counter and make a new, null command. */
3357 struct pipe *pi = ctx->pipe;
3358 struct command *command = ctx->command;
3360 #if 0 /* Instead we emit error message at run time */
3361 if (ctx->pending_redirect) {
3362 /* For example, "cmd >" (no filename to redirect to) */
3363 die_if_script("syntax error: %s", "invalid redirect");
3364 ctx->pending_redirect = NULL;
3369 if (IS_NULL_CMD(command)) {
3370 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3374 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3375 //debug_print_tree(ctx->list_head, 20);
3377 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3380 /* Only real trickiness here is that the uncommitted
3381 * command structure is not counted in pi->num_cmds. */
3382 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3383 ctx->command = command = &pi->cmds[pi->num_cmds];
3385 memset(command, 0, sizeof(*command));
3386 return pi->num_cmds; /* used only for 0/nonzero check */
3389 static void done_pipe(struct parse_context *ctx, pipe_style type)
3393 debug_printf_parse("done_pipe entered, followup %d\n", type);
3394 /* Close previous command */
3395 not_null = done_command(ctx);
3397 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3398 ctx->ctx_inverted = 0;
3399 ctx->pipe->res_word = ctx->ctx_res_w;
3401 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3402 /* Necessary since && and || have precedence over &:
3403 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3404 * in a backgrounded subshell.
3407 struct command *command;
3409 /* Is this actually this construct, all pipes end with && or ||? */
3410 pi = ctx->list_head;
3411 while (pi != ctx->pipe) {
3412 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3417 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3418 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3419 pi = xzalloc(sizeof(*pi));
3420 pi->followup = PIPE_BG;
3422 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3423 command = &pi->cmds[0];
3424 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3425 command->cmd_type = CMD_NORMAL;
3426 command->group = ctx->list_head;
3428 command->group_as_string = xstrndup(
3429 ctx->as_string.data,
3430 ctx->as_string.length - 1 /* do not copy last char, "&" */
3433 /* Replace all pipes in ctx with one newly created */
3434 ctx->list_head = ctx->pipe = pi;
3437 ctx->pipe->followup = type;
3440 /* Without this check, even just <enter> on command line generates
3441 * tree of three NOPs (!). Which is harmless but annoying.
3442 * IOW: it is safe to do it unconditionally. */
3445 || ctx->ctx_res_w == RES_FI
3447 #if ENABLE_HUSH_LOOPS
3448 || ctx->ctx_res_w == RES_DONE
3449 || ctx->ctx_res_w == RES_FOR
3450 || ctx->ctx_res_w == RES_IN
3452 #if ENABLE_HUSH_CASE
3453 || ctx->ctx_res_w == RES_ESAC
3457 debug_printf_parse("done_pipe: adding new pipe: "
3458 "not_null:%d ctx->ctx_res_w:%d\n",
3459 not_null, ctx->ctx_res_w);
3461 ctx->pipe->next = new_p;
3463 /* RES_THEN, RES_DO etc are "sticky" -
3464 * they remain set for pipes inside if/while.
3465 * This is used to control execution.
3466 * RES_FOR and RES_IN are NOT sticky (needed to support
3467 * cases where variable or value happens to match a keyword):
3469 #if ENABLE_HUSH_LOOPS
3470 if (ctx->ctx_res_w == RES_FOR
3471 || ctx->ctx_res_w == RES_IN)
3472 ctx->ctx_res_w = RES_NONE;
3474 #if ENABLE_HUSH_CASE
3475 if (ctx->ctx_res_w == RES_MATCH)
3476 ctx->ctx_res_w = RES_CASE_BODY;
3477 if (ctx->ctx_res_w == RES_CASE)
3478 ctx->ctx_res_w = RES_CASE_IN;
3480 ctx->command = NULL; /* trick done_command below */
3481 /* Create the memory for command, roughly:
3482 * ctx->pipe->cmds = new struct command;
3483 * ctx->command = &ctx->pipe->cmds[0];
3486 //debug_print_tree(ctx->list_head, 10);
3488 debug_printf_parse("done_pipe return\n");
3491 static void initialize_context(struct parse_context *ctx)
3493 memset(ctx, 0, sizeof(*ctx));
3494 ctx->pipe = ctx->list_head = new_pipe();
3495 /* Create the memory for command, roughly:
3496 * ctx->pipe->cmds = new struct command;
3497 * ctx->command = &ctx->pipe->cmds[0];
3502 /* If a reserved word is found and processed, parse context is modified
3503 * and 1 is returned.
3506 struct reserved_combo {
3509 unsigned char assignment_flag;
3513 FLAG_END = (1 << RES_NONE ),
3515 FLAG_IF = (1 << RES_IF ),
3516 FLAG_THEN = (1 << RES_THEN ),
3517 FLAG_ELIF = (1 << RES_ELIF ),
3518 FLAG_ELSE = (1 << RES_ELSE ),
3519 FLAG_FI = (1 << RES_FI ),
3521 # if ENABLE_HUSH_LOOPS
3522 FLAG_FOR = (1 << RES_FOR ),
3523 FLAG_WHILE = (1 << RES_WHILE),
3524 FLAG_UNTIL = (1 << RES_UNTIL),
3525 FLAG_DO = (1 << RES_DO ),
3526 FLAG_DONE = (1 << RES_DONE ),
3527 FLAG_IN = (1 << RES_IN ),
3529 # if ENABLE_HUSH_CASE
3530 FLAG_MATCH = (1 << RES_MATCH),
3531 FLAG_ESAC = (1 << RES_ESAC ),
3533 FLAG_START = (1 << RES_XXXX ),
3536 static const struct reserved_combo* match_reserved_word(o_string *word)
3538 /* Mostly a list of accepted follow-up reserved words.
3539 * FLAG_END means we are done with the sequence, and are ready
3540 * to turn the compound list into a command.
3541 * FLAG_START means the word must start a new compound list.
3543 static const struct reserved_combo reserved_list[] = {
3545 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3546 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3547 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3548 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3549 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3550 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3552 # if ENABLE_HUSH_LOOPS
3553 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3554 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3555 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3556 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3557 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3558 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3560 # if ENABLE_HUSH_CASE
3561 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3562 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3565 const struct reserved_combo *r;
3567 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3568 if (strcmp(word->data, r->literal) == 0)
3573 /* Return 0: not a keyword, 1: keyword
3575 static int reserved_word(o_string *word, struct parse_context *ctx)
3577 # if ENABLE_HUSH_CASE
3578 static const struct reserved_combo reserved_match = {
3579 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3582 const struct reserved_combo *r;
3584 if (word->has_quoted_part)
3586 r = match_reserved_word(word);
3590 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3591 # if ENABLE_HUSH_CASE
3592 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3593 /* "case word IN ..." - IN part starts first MATCH part */
3594 r = &reserved_match;
3597 if (r->flag == 0) { /* '!' */
3598 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3599 syntax_error("! ! command");
3600 ctx->ctx_res_w = RES_SNTX;
3602 ctx->ctx_inverted = 1;
3605 if (r->flag & FLAG_START) {
3606 struct parse_context *old;
3608 old = xmemdup(ctx, sizeof(*ctx));
3609 debug_printf_parse("push stack %p\n", old);
3610 initialize_context(ctx);
3612 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3613 syntax_error_at(word->data);
3614 ctx->ctx_res_w = RES_SNTX;
3617 /* "{...} fi" is ok. "{...} if" is not
3619 * if { echo foo; } then { echo bar; } fi */
3620 if (ctx->command->group)
3621 done_pipe(ctx, PIPE_SEQ);
3624 ctx->ctx_res_w = r->res;
3625 ctx->old_flag = r->flag;
3626 word->o_assignment = r->assignment_flag;
3627 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3629 if (ctx->old_flag & FLAG_END) {
3630 struct parse_context *old;
3632 done_pipe(ctx, PIPE_SEQ);
3633 debug_printf_parse("pop stack %p\n", ctx->stack);
3635 old->command->group = ctx->list_head;
3636 old->command->cmd_type = CMD_NORMAL;
3638 /* At this point, the compound command's string is in
3639 * ctx->as_string... except for the leading keyword!
3640 * Consider this example: "echo a | if true; then echo a; fi"
3641 * ctx->as_string will contain "true; then echo a; fi",
3642 * with "if " remaining in old->as_string!
3646 int len = old->as_string.length;
3647 /* Concatenate halves */
3648 o_addstr(&old->as_string, ctx->as_string.data);
3649 o_free_unsafe(&ctx->as_string);
3650 /* Find where leading keyword starts in first half */
3651 str = old->as_string.data + len;
3652 if (str > old->as_string.data)
3653 str--; /* skip whitespace after keyword */
3654 while (str > old->as_string.data && isalpha(str[-1]))
3656 /* Ugh, we're done with this horrid hack */
3657 old->command->group_as_string = xstrdup(str);
3658 debug_printf_parse("pop, remembering as:'%s'\n",
3659 old->command->group_as_string);
3662 *ctx = *old; /* physical copy */
3667 #endif /* HAS_KEYWORDS */
3669 /* Word is complete, look at it and update parsing context.
3670 * Normal return is 0. Syntax errors return 1.
3671 * Note: on return, word is reset, but not o_free'd!
3673 static int done_word(o_string *word, struct parse_context *ctx)
3675 struct command *command = ctx->command;
3677 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3678 if (word->length == 0 && !word->has_quoted_part) {
3679 debug_printf_parse("done_word return 0: true null, ignored\n");
3683 if (ctx->pending_redirect) {
3684 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3685 * only if run as "bash", not "sh" */
3686 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3688 * ...the word that follows the redirection operator
3689 * shall be subjected to tilde expansion, parameter expansion,
3690 * command substitution, arithmetic expansion, and quote
3691 * removal. Pathname expansion shall not be performed
3692 * on the word by a non-interactive shell; an interactive
3693 * shell may perform it, but shall do so only when
3694 * the expansion would result in one word."
3696 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3697 /* Cater for >\file case:
3698 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3699 * Same with heredocs:
3700 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3702 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3703 unbackslash(ctx->pending_redirect->rd_filename);
3704 /* Is it <<"HEREDOC"? */
3705 if (word->has_quoted_part) {
3706 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3709 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3710 ctx->pending_redirect = NULL;
3713 # if ENABLE_HUSH_CASE
3714 if (ctx->ctx_dsemicolon
3715 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3717 /* already done when ctx_dsemicolon was set to 1: */
3718 /* ctx->ctx_res_w = RES_MATCH; */
3719 ctx->ctx_dsemicolon = 0;
3722 if (!command->argv /* if it's the first word... */
3723 # if ENABLE_HUSH_LOOPS
3724 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3725 && ctx->ctx_res_w != RES_IN
3727 # if ENABLE_HUSH_CASE
3728 && ctx->ctx_res_w != RES_CASE
3731 int reserved = reserved_word(word, ctx);
3732 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3734 o_reset_to_empty_unquoted(word);
3735 debug_printf_parse("done_word return %d\n",
3736 (ctx->ctx_res_w == RES_SNTX));
3737 return (ctx->ctx_res_w == RES_SNTX);
3740 if (strcmp(word->data, "[[") == 0) {
3741 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3747 if (command->group) {
3748 /* "{ echo foo; } echo bar" - bad */
3749 syntax_error_at(word->data);
3750 debug_printf_parse("done_word return 1: syntax error, "
3751 "groups and arglists don't mix\n");
3755 /* If this word wasn't an assignment, next ones definitely
3756 * can't be assignments. Even if they look like ones. */
3757 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3758 && word->o_assignment != WORD_IS_KEYWORD
3760 word->o_assignment = NOT_ASSIGNMENT;
3762 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3763 command->assignment_cnt++;
3764 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3766 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3767 word->o_assignment = MAYBE_ASSIGNMENT;
3769 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3771 if (word->has_quoted_part
3772 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3773 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3774 /* (otherwise it's known to be not empty and is already safe) */
3776 /* exclude "$@" - it can expand to no word despite "" */
3777 char *p = word->data;
3778 while (p[0] == SPECIAL_VAR_SYMBOL
3779 && (p[1] & 0x7f) == '@'
3780 && p[2] == SPECIAL_VAR_SYMBOL
3785 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3786 debug_print_strings("word appended to argv", command->argv);
3789 #if ENABLE_HUSH_LOOPS
3790 if (ctx->ctx_res_w == RES_FOR) {
3791 if (word->has_quoted_part
3792 || !is_well_formed_var_name(command->argv[0], '\0')
3794 /* bash says just "not a valid identifier" */
3795 syntax_error("not a valid identifier in for");
3798 /* Force FOR to have just one word (variable name) */
3799 /* NB: basically, this makes hush see "for v in ..."
3800 * syntax as if it is "for v; in ...". FOR and IN become
3801 * two pipe structs in parse tree. */
3802 done_pipe(ctx, PIPE_SEQ);
3805 #if ENABLE_HUSH_CASE
3806 /* Force CASE to have just one word */
3807 if (ctx->ctx_res_w == RES_CASE) {
3808 done_pipe(ctx, PIPE_SEQ);
3812 o_reset_to_empty_unquoted(word);
3814 debug_printf_parse("done_word return 0\n");
3819 /* Peek ahead in the input to find out if we have a "&n" construct,
3820 * as in "2>&1", that represents duplicating a file descriptor.
3822 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3823 * REDIRFD_SYNTAX_ERR if syntax error,
3824 * REDIRFD_TO_FILE if no & was seen,
3825 * or the number found.
3828 #define parse_redir_right_fd(as_string, input) \
3829 parse_redir_right_fd(input)
3831 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3837 return REDIRFD_TO_FILE;
3839 ch = i_getch(input); /* get the & */
3840 nommu_addchr(as_string, ch);
3843 ch = i_getch(input);
3844 nommu_addchr(as_string, ch);
3845 return REDIRFD_CLOSE;
3849 while (ch != EOF && isdigit(ch)) {
3850 d = d*10 + (ch-'0');
3852 ch = i_getch(input);
3853 nommu_addchr(as_string, ch);
3858 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3860 bb_error_msg("ambiguous redirect");
3861 return REDIRFD_SYNTAX_ERR;
3864 /* Return code is 0 normal, 1 if a syntax error is detected
3866 static int parse_redirect(struct parse_context *ctx,
3869 struct in_str *input)
3871 struct command *command = ctx->command;
3872 struct redir_struct *redir;
3873 struct redir_struct **redirp;
3876 dup_num = REDIRFD_TO_FILE;
3877 if (style != REDIRECT_HEREDOC) {
3878 /* Check for a '>&1' type redirect */
3879 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3880 if (dup_num == REDIRFD_SYNTAX_ERR)
3883 int ch = i_peek(input);
3884 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3885 if (dup_num) { /* <<-... */
3886 ch = i_getch(input);
3887 nommu_addchr(&ctx->as_string, ch);
3892 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3893 int ch = i_peek(input);
3895 /* >|FILE redirect ("clobbering" >).
3896 * Since we do not support "set -o noclobber" yet,
3897 * >| and > are the same for now. Just eat |.
3899 ch = i_getch(input);
3900 nommu_addchr(&ctx->as_string, ch);
3904 /* Create a new redir_struct and append it to the linked list */
3905 redirp = &command->redirects;
3906 while ((redir = *redirp) != NULL) {
3907 redirp = &(redir->next);
3909 *redirp = redir = xzalloc(sizeof(*redir));
3910 /* redir->next = NULL; */
3911 /* redir->rd_filename = NULL; */
3912 redir->rd_type = style;
3913 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3915 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3916 redir_table[style].descrip);
3918 redir->rd_dup = dup_num;
3919 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3920 /* Erik had a check here that the file descriptor in question
3921 * is legit; I postpone that to "run time"
3922 * A "-" representation of "close me" shows up as a -3 here */
3923 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3924 redir->rd_fd, redir->rd_dup);
3926 #if 0 /* Instead we emit error message at run time */
3927 if (ctx->pending_redirect) {
3928 /* For example, "cmd > <file" */
3929 die_if_script("syntax error: %s", "invalid redirect");
3932 /* Set ctx->pending_redirect, so we know what to do at the
3933 * end of the next parsed word. */
3934 ctx->pending_redirect = redir;
3939 /* If a redirect is immediately preceded by a number, that number is
3940 * supposed to tell which file descriptor to redirect. This routine
3941 * looks for such preceding numbers. In an ideal world this routine
3942 * needs to handle all the following classes of redirects...
3943 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3944 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3945 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3946 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3948 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3950 * ... If n is quoted, the number shall not be recognized as part of
3951 * the redirection expression. For example:
3953 * writes the character 2 into file a"
3954 * We are getting it right by setting ->has_quoted_part on any \<char>
3956 * A -1 return means no valid number was found,
3957 * the caller should use the appropriate default for this redirection.
3959 static int redirect_opt_num(o_string *o)
3963 if (o->data == NULL)
3965 num = bb_strtou(o->data, NULL, 10);
3966 if (errno || num < 0)
3968 o_reset_to_empty_unquoted(o);
3973 #define fetch_till_str(as_string, input, word, skip_tabs) \
3974 fetch_till_str(input, word, skip_tabs)
3976 static char *fetch_till_str(o_string *as_string,
3977 struct in_str *input,
3981 o_string heredoc = NULL_O_STRING;
3983 int prev = 0; /* not \ */
3989 ch = i_getch(input);
3991 nommu_addchr(as_string, ch);
3992 if ((ch == '\n' || ch == EOF)
3993 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3995 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3996 heredoc.data[past_EOL] = '\0';
3997 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3998 return heredoc.data;
4000 while (ch == '\n') {
4001 o_addchr(&heredoc, ch);
4004 past_EOL = heredoc.length;
4006 ch = i_getch(input);
4008 nommu_addchr(as_string, ch);
4009 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4013 o_free_unsafe(&heredoc);
4016 o_addchr(&heredoc, ch);
4017 nommu_addchr(as_string, ch);
4018 if (prev == '\\' && ch == '\\')
4019 /* Correctly handle foo\\<eol> (not a line cont.) */
4020 prev = 0; /* not \ */
4026 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4027 * and load them all. There should be exactly heredoc_cnt of them.
4029 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4031 struct pipe *pi = ctx->list_head;
4033 while (pi && heredoc_cnt) {
4035 struct command *cmd = pi->cmds;
4037 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4039 cmd->argv ? cmd->argv[0] : "NONE");
4040 for (i = 0; i < pi->num_cmds; i++) {
4041 struct redir_struct *redir = cmd->redirects;
4043 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4044 i, cmd->argv ? cmd->argv[0] : "NONE");
4046 if (redir->rd_type == REDIRECT_HEREDOC) {
4049 redir->rd_type = REDIRECT_HEREDOC2;
4050 /* redir->rd_dup is (ab)used to indicate <<- */
4051 p = fetch_till_str(&ctx->as_string, input,
4052 redir->rd_filename, redir->rd_dup);
4054 syntax_error("unexpected EOF in here document");
4057 free(redir->rd_filename);
4058 redir->rd_filename = p;
4061 redir = redir->next;
4068 /* Should be 0. If it isn't, it's a parse error */
4070 bb_error_msg_and_die("heredoc BUG 2");
4076 static int run_list(struct pipe *pi);
4078 #define parse_stream(pstring, input, end_trigger) \
4079 parse_stream(input, end_trigger)
4081 static struct pipe *parse_stream(char **pstring,
4082 struct in_str *input,
4086 #if !ENABLE_HUSH_FUNCTIONS
4087 #define parse_group(dest, ctx, input, ch) \
4088 parse_group(ctx, input, ch)
4090 static int parse_group(o_string *dest, struct parse_context *ctx,
4091 struct in_str *input, int ch)
4093 /* dest contains characters seen prior to ( or {.
4094 * Typically it's empty, but for function defs,
4095 * it contains function name (without '()'). */
4096 struct pipe *pipe_list;
4098 struct command *command = ctx->command;
4100 debug_printf_parse("parse_group entered\n");
4101 #if ENABLE_HUSH_FUNCTIONS
4102 if (ch == '(' && !dest->has_quoted_part) {
4104 if (done_word(dest, ctx))
4107 goto skip; /* (... */
4108 if (command->argv[1]) { /* word word ... (... */
4109 syntax_error_unexpected_ch('(');
4112 /* it is "word(..." or "word (..." */
4114 ch = i_getch(input);
4115 while (ch == ' ' || ch == '\t');
4117 syntax_error_unexpected_ch(ch);
4120 nommu_addchr(&ctx->as_string, ch);
4122 ch = i_getch(input);
4123 while (ch == ' ' || ch == '\t' || ch == '\n');
4125 syntax_error_unexpected_ch(ch);
4128 nommu_addchr(&ctx->as_string, ch);
4129 command->cmd_type = CMD_FUNCDEF;
4134 #if 0 /* Prevented by caller */
4135 if (command->argv /* word [word]{... */
4136 || dest->length /* word{... */
4137 || dest->has_quoted_part /* ""{... */
4140 debug_printf_parse("parse_group return 1: "
4141 "syntax error, groups and arglists don't mix\n");
4146 #if ENABLE_HUSH_FUNCTIONS
4152 command->cmd_type = CMD_SUBSHELL;
4154 /* bash does not allow "{echo...", requires whitespace */
4156 if (ch != ' ' && ch != '\t' && ch != '\n'
4157 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4159 syntax_error_unexpected_ch(ch);
4163 ch = i_getch(input);
4164 nommu_addchr(&ctx->as_string, ch);
4170 # define as_string NULL
4172 char *as_string = NULL;
4174 pipe_list = parse_stream(&as_string, input, endch);
4177 o_addstr(&ctx->as_string, as_string);
4179 /* empty ()/{} or parse error? */
4180 if (!pipe_list || pipe_list == ERR_PTR) {
4181 /* parse_stream already emitted error msg */
4184 debug_printf_parse("parse_group return 1: "
4185 "parse_stream returned %p\n", pipe_list);
4188 command->group = pipe_list;
4190 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4191 command->group_as_string = as_string;
4192 debug_printf_parse("end of group, remembering as:'%s'\n",
4193 command->group_as_string);
4197 debug_printf_parse("parse_group return 0\n");
4199 /* command remains "open", available for possible redirects */
4202 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4207 ch = i_getch(input);
4210 ch2 = i_peek(input);
4213 /* backslash+newline, skip it */
4218 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4226 ch2 = i_peek2(input);
4229 /* backslash+newline, skip it */
4235 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4236 /* Subroutines for copying $(...) and `...` things */
4237 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4239 static int add_till_single_quote(o_string *dest, struct in_str *input)
4242 int ch = i_getch(input);
4244 syntax_error_unterm_ch('\'');
4252 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4253 static int add_till_double_quote(o_string *dest, struct in_str *input)
4256 int ch = i_getch(input);
4258 syntax_error_unterm_ch('"');
4263 if (ch == '\\') { /* \x. Copy both chars. */
4265 ch = i_getch(input);
4269 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4274 //if (ch == '$') ...
4277 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4279 * "Within the backquoted style of command substitution, backslash
4280 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4281 * The search for the matching backquote shall be satisfied by the first
4282 * backquote found without a preceding backslash; during this search,
4283 * if a non-escaped backquote is encountered within a shell comment,
4284 * a here-document, an embedded command substitution of the $(command)
4285 * form, or a quoted string, undefined results occur. A single-quoted
4286 * or double-quoted string that begins, but does not end, within the
4287 * "`...`" sequence produces undefined results."
4289 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4291 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4294 int ch = i_getch(input);
4298 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4299 ch = i_getch(input);
4303 && (!in_dquote || ch != '"')
4305 o_addchr(dest, '\\');
4309 syntax_error_unterm_ch('`');
4315 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4316 * quoting and nested ()s.
4317 * "With the $(command) style of command substitution, all characters
4318 * following the open parenthesis to the matching closing parenthesis
4319 * constitute the command. Any valid shell script can be used for command,
4320 * except a script consisting solely of redirections which produces
4321 * unspecified results."
4323 * echo $(echo '(TEST)' BEST) (TEST) BEST
4324 * echo $(echo 'TEST)' BEST) TEST) BEST
4325 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4327 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4328 * can contain arbitrary constructs, just like $(cmd).
4329 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4330 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4332 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4333 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4336 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4337 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4338 char end_char2 = end_ch >> 8;
4340 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4343 ch = i_getch(input);
4345 syntax_error_unterm_ch(end_ch);
4349 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4355 /* we look for closing )) of $((EXPR)) */
4356 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4357 i_getch(input); /* eat second ')' */
4362 if (ch == '(' || ch == '{') {
4363 ch = (ch == '(' ? ')' : '}');
4364 if (!add_till_closing_bracket(dest, input, ch))
4370 if (!add_till_single_quote(dest, input))
4376 if (!add_till_double_quote(dest, input))
4382 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4388 /* \x. Copy verbatim. Important for \(, \) */
4389 ch = i_getch(input);
4391 syntax_error_unterm_ch(')');
4396 /* "backslash+newline", ignore both */
4397 o_delchr(dest); /* undo insertion of '\' */
4407 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4409 /* Return code: 0 for OK, 1 for syntax error */
4411 #define parse_dollar(as_string, dest, input, quote_mask) \
4412 parse_dollar(dest, input, quote_mask)
4413 #define as_string NULL
4415 static int parse_dollar(o_string *as_string,
4417 struct in_str *input, unsigned char quote_mask)
4419 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4421 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4423 ch = i_getch(input);
4424 nommu_addchr(as_string, ch);
4426 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4428 debug_printf_parse(": '%c'\n", ch);
4429 o_addchr(dest, ch | quote_mask);
4431 ch = i_peek_and_eat_bkslash_nl(input);
4432 if (!isalnum(ch) && ch != '_') {
4433 /* End of variable name reached */
4436 ch = i_getch(input);
4437 nommu_addchr(as_string, ch);
4439 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4440 } else if (isdigit(ch)) {
4442 ch = i_getch(input);
4443 nommu_addchr(as_string, ch);
4444 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4445 debug_printf_parse(": '%c'\n", ch);
4446 o_addchr(dest, ch | quote_mask);
4447 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4448 } else switch (ch) {
4450 case '!': /* last bg pid */
4451 case '?': /* last exit code */
4452 case '#': /* number of args */
4453 case '*': /* args */
4454 case '@': /* args */
4455 goto make_one_char_var;
4457 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4459 ch = i_getch(input); /* eat '{' */
4460 nommu_addchr(as_string, ch);
4462 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4463 /* It should be ${?}, or ${#var},
4464 * or even ${?+subst} - operator acting on a special variable,
4465 * or the beginning of variable name.
4468 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4471 syntax_error_unterm_str("${name}");
4472 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4475 nommu_addchr(as_string, ch);
4478 /* It's possible to just call add_till_closing_bracket() at this point.
4479 * However, this regresses some of our testsuite cases
4480 * which check invalid constructs like ${%}.
4481 * Oh well... let's check that the var name part is fine... */
4487 debug_printf_parse(": '%c'\n", ch);
4489 ch = i_getch(input);
4490 nommu_addchr(as_string, ch);
4494 if (!isalnum(ch) && ch != '_') {
4496 unsigned char last_ch;
4497 /* handle parameter expansions
4498 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4500 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4501 goto bad_dollar_syntax;
4503 /* Eat everything until closing '}' (or ':') */
4507 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4509 /* It's ${var:N[:M]} thing */
4510 end_ch = '}' * 0x100 + ':';
4512 if (BASH_PATTERN_SUBST
4515 /* It's ${var/[/]pattern[/repl]} thing */
4516 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4518 nommu_addchr(as_string, '/');
4521 end_ch = '}' * 0x100 + '/';
4527 #if ENABLE_HUSH_DOLLAR_OPS
4528 last_ch = add_till_closing_bracket(dest, input, end_ch);
4529 if (last_ch == 0) /* error? */
4532 #error Simple code to only allow ${var} is not implemented
4535 o_addstr(as_string, dest->data + pos);
4536 o_addchr(as_string, last_ch);
4539 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4540 && (end_ch & 0xff00)
4542 /* close the first block: */
4543 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4544 /* while parsing N from ${var:N[:M]}
4545 * or pattern from ${var/[/]pattern[/repl]} */
4546 if ((end_ch & 0xff) == last_ch) {
4547 /* got ':' or '/'- parse the rest */
4552 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4553 /* it's ${var:N} - emulate :999999999 */
4554 o_addstr(dest, "999999999");
4555 } /* else: it's ${var/[/]pattern} */
4560 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4563 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4567 ch = i_getch(input);
4568 nommu_addchr(as_string, ch);
4569 # if ENABLE_FEATURE_SH_MATH
4570 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4571 ch = i_getch(input);
4572 nommu_addchr(as_string, ch);
4573 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4574 o_addchr(dest, /*quote_mask |*/ '+');
4577 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4578 return 0; /* error */
4580 o_addstr(as_string, dest->data + pos);
4581 o_addchr(as_string, ')');
4582 o_addchr(as_string, ')');
4584 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4588 # if ENABLE_HUSH_TICK
4589 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4590 o_addchr(dest, quote_mask | '`');
4593 if (!add_till_closing_bracket(dest, input, ')'))
4594 return 0; /* error */
4596 o_addstr(as_string, dest->data + pos);
4597 o_addchr(as_string, ')');
4599 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4605 ch = i_getch(input);
4606 nommu_addchr(as_string, ch);
4607 ch = i_peek_and_eat_bkslash_nl(input);
4608 if (isalnum(ch)) { /* it's $_name or $_123 */
4613 /* TODO: $_ and $-: */
4614 /* $_ Shell or shell script name; or last argument of last command
4615 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4616 * but in command's env, set to full pathname used to invoke it */
4617 /* $- Option flags set by set builtin or shell options (-i etc) */
4619 o_addQchr(dest, '$');
4621 debug_printf_parse("parse_dollar return 1 (ok)\n");
4627 # if BASH_PATTERN_SUBST
4628 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4629 encode_string(dest, input, dquote_end, process_bkslash)
4631 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4632 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4633 encode_string(dest, input, dquote_end)
4635 #define as_string NULL
4639 # if BASH_PATTERN_SUBST
4640 /* all parameters are needed, no macro tricks */
4642 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4643 encode_string(as_string, dest, input, dquote_end)
4646 static int encode_string(o_string *as_string,
4648 struct in_str *input,
4650 int process_bkslash)
4652 #if !BASH_PATTERN_SUBST
4653 const int process_bkslash = 1;
4659 ch = i_getch(input);
4661 nommu_addchr(as_string, ch);
4662 if (ch == dquote_end) { /* may be only '"' or EOF */
4663 debug_printf_parse("encode_string return 1 (ok)\n");
4666 /* note: can't move it above ch == dquote_end check! */
4668 syntax_error_unterm_ch('"');
4669 return 0; /* error */
4673 next = i_peek(input);
4675 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4676 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4677 if (process_bkslash && ch == '\\') {
4679 syntax_error("\\<eof>");
4683 * "The backslash retains its special meaning [in "..."]
4684 * only when followed by one of the following characters:
4685 * $, `, ", \, or <newline>. A double quote may be quoted
4686 * within double quotes by preceding it with a backslash."
4687 * NB: in (unquoted) heredoc, above does not apply to ",
4688 * therefore we check for it by "next == dquote_end" cond.
4690 if (next == dquote_end || strchr("$`\\\n", next)) {
4691 ch = i_getch(input); /* eat next */
4693 goto again; /* skip \<newline> */
4694 } /* else: ch remains == '\\', and we double it below: */
4695 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4696 nommu_addchr(as_string, ch);
4700 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4701 debug_printf_parse("encode_string return 0: "
4702 "parse_dollar returned 0 (error)\n");
4707 #if ENABLE_HUSH_TICK
4709 //unsigned pos = dest->length;
4710 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4711 o_addchr(dest, 0x80 | '`');
4712 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4713 return 0; /* error */
4714 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4715 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4719 o_addQchr(dest, ch);
4725 * Scan input until EOF or end_trigger char.
4726 * Return a list of pipes to execute, or NULL on EOF
4727 * or if end_trigger character is met.
4728 * On syntax error, exit if shell is not interactive,
4729 * reset parsing machinery and start parsing anew,
4730 * or return ERR_PTR.
4732 static struct pipe *parse_stream(char **pstring,
4733 struct in_str *input,
4736 struct parse_context ctx;
4737 o_string dest = NULL_O_STRING;
4740 /* Single-quote triggers a bypass of the main loop until its mate is
4741 * found. When recursing, quote state is passed in via dest->o_expflags.
4743 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4744 end_trigger ? end_trigger : 'X');
4747 /* If very first arg is "" or '', dest.data may end up NULL.
4748 * Preventing this: */
4749 o_addchr(&dest, '\0');
4752 /* We used to separate words on $IFS here. This was wrong.
4753 * $IFS is used only for word splitting when $var is expanded,
4754 * here we should use blank chars as separators, not $IFS
4757 if (MAYBE_ASSIGNMENT != 0)
4758 dest.o_assignment = MAYBE_ASSIGNMENT;
4759 initialize_context(&ctx);
4762 const char *is_blank;
4763 const char *is_special;
4767 redir_type redir_style;
4769 ch = i_getch(input);
4770 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4771 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4776 syntax_error_unterm_str("here document");
4779 if (end_trigger == ')') {
4780 syntax_error_unterm_ch('(');
4783 if (end_trigger == '}') {
4784 syntax_error_unterm_ch('{');
4788 if (done_word(&dest, &ctx)) {
4792 done_pipe(&ctx, PIPE_SEQ);
4794 /* If we got nothing... */
4795 /* (this makes bare "&" cmd a no-op.
4796 * bash says: "syntax error near unexpected token '&'") */
4797 if (pi->num_cmds == 0
4798 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4804 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4806 *pstring = ctx.as_string.data;
4808 o_free_unsafe(&ctx.as_string);
4811 debug_printf_parse("parse_stream return %p\n", pi);
4814 nommu_addchr(&ctx.as_string, ch);
4818 next = i_peek(input);
4820 is_special = "{}<>;&|()#'" /* special outside of "str" */
4821 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4822 /* Are { and } special here? */
4823 if (ctx.command->argv /* word [word]{... - non-special */
4824 || dest.length /* word{... - non-special */
4825 || dest.has_quoted_part /* ""{... - non-special */
4826 || (next != ';' /* }; - special */
4827 && next != ')' /* }) - special */
4828 && next != '(' /* {( - special */
4829 && next != '&' /* }& and }&& ... - special */
4830 && next != '|' /* }|| ... - special */
4831 && !strchr(defifs, next) /* {word - non-special */
4834 /* They are not special, skip "{}" */
4837 is_special = strchr(is_special, ch);
4838 is_blank = strchr(defifs, ch);
4840 if (!is_special && !is_blank) { /* ordinary char */
4842 o_addQchr(&dest, ch);
4843 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4844 || dest.o_assignment == WORD_IS_KEYWORD)
4846 && is_well_formed_var_name(dest.data, '=')
4848 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4849 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4855 if (done_word(&dest, &ctx)) {
4859 /* Is this a case when newline is simply ignored?
4861 * "cmd | <newline> cmd ..."
4862 * "case ... in <newline> word) ..."
4864 if (IS_NULL_CMD(ctx.command)
4865 && dest.length == 0 && !dest.has_quoted_part
4867 /* This newline can be ignored. But...
4868 * Without check #1, interactive shell
4869 * ignores even bare <newline>,
4870 * and shows the continuation prompt:
4871 * ps1_prompt$ <enter>
4872 * ps2> _ <=== wrong, should be ps1
4873 * Without check #2, "cmd & <newline>"
4874 * is similarly mistreated.
4875 * (BTW, this makes "cmd & cmd"
4876 * and "cmd && cmd" non-orthogonal.
4877 * Really, ask yourself, why
4878 * "cmd && <newline>" doesn't start
4879 * cmd but waits for more input?
4880 * The only reason is that it might be
4881 * a "cmd1 && <nl> cmd2 &" construct,
4882 * cmd1 may need to run in BG).
4884 struct pipe *pi = ctx.list_head;
4885 if (pi->num_cmds != 0 /* check #1 */
4886 && pi->followup != PIPE_BG /* check #2 */
4891 /* Treat newline as a command separator. */
4892 done_pipe(&ctx, PIPE_SEQ);
4893 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4895 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4900 dest.o_assignment = MAYBE_ASSIGNMENT;
4901 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4903 /* note: if (is_blank) continue;
4904 * will still trigger for us */
4908 /* "cmd}" or "cmd }..." without semicolon or &:
4909 * } is an ordinary char in this case, even inside { cmd; }
4910 * Pathological example: { ""}; } should exec "}" cmd
4913 if (dest.length != 0 /* word} */
4914 || dest.has_quoted_part /* ""} */
4918 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4919 /* Generally, there should be semicolon: "cmd; }"
4920 * However, bash allows to omit it if "cmd" is
4921 * a group. Examples:
4924 * { echo 0 >&2 | { echo 1; } }
4925 * { while false; do :; done }
4926 * { case a in b) ;; esac }
4928 if (ctx.command->group)
4932 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4933 /* Can't be an end of {cmd}, skip the check */
4934 goto skip_end_trigger;
4935 /* else: } does terminate a group */
4938 if (end_trigger && end_trigger == ch
4939 && (ch != ';' || heredoc_cnt == 0)
4940 #if ENABLE_HUSH_CASE
4942 || ctx.ctx_res_w != RES_MATCH
4943 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4948 /* This is technically valid:
4949 * { cat <<HERE; }; echo Ok
4953 * but we don't support this.
4954 * We require heredoc to be in enclosing {}/(),
4957 syntax_error_unterm_str("here document");
4960 if (done_word(&dest, &ctx)) {
4963 done_pipe(&ctx, PIPE_SEQ);
4964 dest.o_assignment = MAYBE_ASSIGNMENT;
4965 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4966 /* Do we sit outside of any if's, loops or case's? */
4968 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4972 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4974 *pstring = ctx.as_string.data;
4976 o_free_unsafe(&ctx.as_string);
4979 debug_printf_parse("parse_stream return %p: "
4980 "end_trigger char found\n",
4982 return ctx.list_head;
4989 /* Catch <, > before deciding whether this word is
4990 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4993 redir_fd = redirect_opt_num(&dest);
4994 if (done_word(&dest, &ctx)) {
4997 redir_style = REDIRECT_OVERWRITE;
4999 redir_style = REDIRECT_APPEND;
5000 ch = i_getch(input);
5001 nommu_addchr(&ctx.as_string, ch);
5004 else if (next == '(') {
5005 syntax_error(">(process) not supported");
5009 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5011 continue; /* back to top of while (1) */
5013 redir_fd = redirect_opt_num(&dest);
5014 if (done_word(&dest, &ctx)) {
5017 redir_style = REDIRECT_INPUT;
5019 redir_style = REDIRECT_HEREDOC;
5021 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5022 ch = i_getch(input);
5023 nommu_addchr(&ctx.as_string, ch);
5024 } else if (next == '>') {
5025 redir_style = REDIRECT_IO;
5026 ch = i_getch(input);
5027 nommu_addchr(&ctx.as_string, ch);
5030 else if (next == '(') {
5031 syntax_error("<(process) not supported");
5035 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5037 continue; /* back to top of while (1) */
5039 if (dest.length == 0 && !dest.has_quoted_part) {
5040 /* skip "#comment" */
5043 if (ch == EOF || ch == '\n')
5046 /* note: we do not add it to &ctx.as_string */
5048 nommu_addchr(&ctx.as_string, '\n');
5049 continue; /* back to top of while (1) */
5054 /* It's "\<newline>" */
5056 /* Remove trailing '\' from ctx.as_string */
5057 ctx.as_string.data[--ctx.as_string.length] = '\0';
5059 ch = i_getch(input); /* eat it */
5060 continue; /* back to top of while (1) */
5065 if (dest.o_assignment == MAYBE_ASSIGNMENT
5066 /* check that we are not in word in "a=1 2>word b=1": */
5067 && !ctx.pending_redirect
5069 /* ch is a special char and thus this word
5070 * cannot be an assignment */
5071 dest.o_assignment = NOT_ASSIGNMENT;
5072 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5075 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5078 case '#': /* non-comment #: "echo a#b" etc */
5079 o_addQchr(&dest, ch);
5083 syntax_error("\\<eof>");
5086 ch = i_getch(input);
5087 /* note: ch != '\n' (that case does not reach this place) */
5088 o_addchr(&dest, '\\');
5089 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5090 o_addchr(&dest, ch);
5091 nommu_addchr(&ctx.as_string, ch);
5092 /* Example: echo Hello \2>file
5093 * we need to know that word 2 is quoted */
5094 dest.has_quoted_part = 1;
5097 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5098 debug_printf_parse("parse_stream parse error: "
5099 "parse_dollar returned 0 (error)\n");
5104 dest.has_quoted_part = 1;
5105 if (next == '\'' && !ctx.pending_redirect) {
5106 insert_empty_quoted_str_marker:
5107 nommu_addchr(&ctx.as_string, next);
5108 i_getch(input); /* eat second ' */
5109 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5110 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5113 ch = i_getch(input);
5115 syntax_error_unterm_ch('\'');
5118 nommu_addchr(&ctx.as_string, ch);
5121 o_addqchr(&dest, ch);
5126 dest.has_quoted_part = 1;
5127 if (next == '"' && !ctx.pending_redirect)
5128 goto insert_empty_quoted_str_marker;
5129 if (dest.o_assignment == NOT_ASSIGNMENT)
5130 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5131 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5133 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5135 #if ENABLE_HUSH_TICK
5137 USE_FOR_NOMMU(unsigned pos;)
5139 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5140 o_addchr(&dest, '`');
5141 USE_FOR_NOMMU(pos = dest.length;)
5142 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5145 o_addstr(&ctx.as_string, dest.data + pos);
5146 o_addchr(&ctx.as_string, '`');
5148 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5149 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5154 #if ENABLE_HUSH_CASE
5157 if (done_word(&dest, &ctx)) {
5160 done_pipe(&ctx, PIPE_SEQ);
5161 #if ENABLE_HUSH_CASE
5162 /* Eat multiple semicolons, detect
5163 * whether it means something special */
5168 ch = i_getch(input);
5169 nommu_addchr(&ctx.as_string, ch);
5170 if (ctx.ctx_res_w == RES_CASE_BODY) {
5171 ctx.ctx_dsemicolon = 1;
5172 ctx.ctx_res_w = RES_MATCH;
5178 /* We just finished a cmd. New one may start
5179 * with an assignment */
5180 dest.o_assignment = MAYBE_ASSIGNMENT;
5181 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5184 if (done_word(&dest, &ctx)) {
5188 ch = i_getch(input);
5189 nommu_addchr(&ctx.as_string, ch);
5190 done_pipe(&ctx, PIPE_AND);
5192 done_pipe(&ctx, PIPE_BG);
5196 if (done_word(&dest, &ctx)) {
5199 #if ENABLE_HUSH_CASE
5200 if (ctx.ctx_res_w == RES_MATCH)
5201 break; /* we are in case's "word | word)" */
5203 if (next == '|') { /* || */
5204 ch = i_getch(input);
5205 nommu_addchr(&ctx.as_string, ch);
5206 done_pipe(&ctx, PIPE_OR);
5208 /* we could pick up a file descriptor choice here
5209 * with redirect_opt_num(), but bash doesn't do it.
5210 * "echo foo 2| cat" yields "foo 2". */
5215 #if ENABLE_HUSH_CASE
5216 /* "case... in [(]word)..." - skip '(' */
5217 if (ctx.ctx_res_w == RES_MATCH
5218 && ctx.command->argv == NULL /* not (word|(... */
5219 && dest.length == 0 /* not word(... */
5220 && dest.has_quoted_part == 0 /* not ""(... */
5226 if (parse_group(&dest, &ctx, input, ch) != 0) {
5231 #if ENABLE_HUSH_CASE
5232 if (ctx.ctx_res_w == RES_MATCH)
5236 /* proper use of this character is caught by end_trigger:
5237 * if we see {, we call parse_group(..., end_trigger='}')
5238 * and it will match } earlier (not here). */
5239 syntax_error_unexpected_ch(ch);
5240 G.last_exitcode = 2;
5244 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5249 G.last_exitcode = 1;
5252 struct parse_context *pctx;
5253 IF_HAS_KEYWORDS(struct parse_context *p2;)
5255 /* Clean up allocated tree.
5256 * Sample for finding leaks on syntax error recovery path.
5257 * Run it from interactive shell, watch pmap `pidof hush`.
5258 * while if false; then false; fi; do break; fi
5259 * Samples to catch leaks at execution:
5260 * while if (true | { true;}); then echo ok; fi; do break; done
5261 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5265 /* Update pipe/command counts,
5266 * otherwise freeing may miss some */
5267 done_pipe(pctx, PIPE_SEQ);
5268 debug_printf_clean("freeing list %p from ctx %p\n",
5269 pctx->list_head, pctx);
5270 debug_print_tree(pctx->list_head, 0);
5271 free_pipe_list(pctx->list_head);
5272 debug_printf_clean("freed list %p\n", pctx->list_head);
5274 o_free_unsafe(&pctx->as_string);
5276 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5280 IF_HAS_KEYWORDS(pctx = p2;)
5281 } while (HAS_KEYWORDS && pctx);
5294 /*** Execution routines ***/
5296 /* Expansion can recurse, need forward decls: */
5297 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5298 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5299 #define expand_string_to_string(str, do_unbackslash) \
5300 expand_string_to_string(str)
5302 static char *expand_string_to_string(const char *str, int do_unbackslash);
5303 #if ENABLE_HUSH_TICK
5304 static int process_command_subs(o_string *dest, const char *s);
5307 /* expand_strvec_to_strvec() takes a list of strings, expands
5308 * all variable references within and returns a pointer to
5309 * a list of expanded strings, possibly with larger number
5310 * of strings. (Think VAR="a b"; echo $VAR).
5311 * This new list is allocated as a single malloc block.
5312 * NULL-terminated list of char* pointers is at the beginning of it,
5313 * followed by strings themselves.
5314 * Caller can deallocate entire list by single free(list). */
5316 /* A horde of its helpers come first: */
5318 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5320 while (--len >= 0) {
5323 #if ENABLE_HUSH_BRACE_EXPANSION
5324 if (c == '{' || c == '}') {
5325 /* { -> \{, } -> \} */
5327 /* And now we want to add { or } and continue:
5330 * luckily, just falling through achieves this.
5336 /* \z -> \\\z; \<eol> -> \\<eol> */
5341 o_addchr(o, *str++);
5347 /* Store given string, finalizing the word and starting new one whenever
5348 * we encounter IFS char(s). This is used for expanding variable values.
5349 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5350 * Return in *ended_with_ifs:
5351 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5353 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5355 int last_is_ifs = 0;
5360 if (!*str) /* EOL - do not finalize word */
5362 word_len = strcspn(str, G.ifs);
5364 /* We have WORD_LEN leading non-IFS chars */
5365 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5366 o_addblock(output, str, word_len);
5368 /* Protect backslashes against globbing up :)
5369 * Example: "v='\*'; echo b$v" prints "b\*"
5370 * (and does not try to glob on "*")
5372 o_addblock_duplicate_backslash(output, str, word_len);
5373 /*/ Why can't we do it easier? */
5374 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5375 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5379 if (!*str) /* EOL - do not finalize word */
5383 /* We know str here points to at least one IFS char */
5385 str += strspn(str, G.ifs); /* skip IFS chars */
5386 if (!*str) /* EOL - do not finalize word */
5389 /* Start new word... but not always! */
5390 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5391 if (output->has_quoted_part
5392 /* Case "v=' a'; echo $v":
5393 * here nothing precedes the space in $v expansion,
5394 * therefore we should not finish the word
5395 * (IOW: if there *is* word to finalize, only then do it):
5397 || (n > 0 && output->data[output->length - 1])
5399 o_addchr(output, '\0');
5400 debug_print_list("expand_on_ifs", output, n);
5401 n = o_save_ptr(output, n);
5406 *ended_with_ifs = last_is_ifs;
5407 debug_print_list("expand_on_ifs[1]", output, n);
5411 /* Helper to expand $((...)) and heredoc body. These act as if
5412 * they are in double quotes, with the exception that they are not :).
5413 * Just the rules are similar: "expand only $var and `cmd`"
5415 * Returns malloced string.
5416 * As an optimization, we return NULL if expansion is not needed.
5418 #if !BASH_PATTERN_SUBST
5419 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5420 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5421 encode_then_expand_string(str)
5423 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5425 #if !BASH_PATTERN_SUBST
5426 const int do_unbackslash = 1;
5429 struct in_str input;
5430 o_string dest = NULL_O_STRING;
5432 if (!strchr(str, '$')
5433 && !strchr(str, '\\')
5434 #if ENABLE_HUSH_TICK
5435 && !strchr(str, '`')
5441 /* We need to expand. Example:
5442 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5444 setup_string_in_str(&input, str);
5445 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5446 //TODO: error check (encode_string returns 0 on error)?
5447 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5448 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5449 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5450 o_free_unsafe(&dest);
5454 #if ENABLE_FEATURE_SH_MATH
5455 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5457 arith_state_t math_state;
5461 math_state.lookupvar = get_local_var_value;
5462 math_state.setvar = set_local_var_from_halves;
5463 //math_state.endofname = endofname;
5464 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5465 res = arith(&math_state, exp_str ? exp_str : arg);
5468 *errmsg_p = math_state.errmsg;
5469 if (math_state.errmsg)
5470 die_if_script(math_state.errmsg);
5475 #if BASH_PATTERN_SUBST
5476 /* ${var/[/]pattern[/repl]} helpers */
5477 static char *strstr_pattern(char *val, const char *pattern, int *size)
5480 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5481 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5488 /* Optimization: if "*pat" did not match the start of "string",
5489 * we know that "tring", "ring" etc will not match too:
5491 if (pattern[0] == '*')
5496 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5498 char *result = NULL;
5499 unsigned res_len = 0;
5500 unsigned repl_len = strlen(repl);
5504 char *s = strstr_pattern(val, pattern, &size);
5508 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5509 memcpy(result + res_len, val, s - val);
5511 strcpy(result + res_len, repl);
5512 res_len += repl_len;
5513 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5519 if (val[0] && result) {
5520 result = xrealloc(result, res_len + strlen(val) + 1);
5521 strcpy(result + res_len, val);
5522 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5524 debug_printf_varexp("result:'%s'\n", result);
5527 #endif /* BASH_PATTERN_SUBST */
5530 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5532 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5534 const char *val = NULL;
5535 char *to_be_freed = NULL;
5540 char exp_save = exp_save; /* for compiler */
5541 char *exp_saveptr; /* points to expansion operator */
5542 char *exp_word = exp_word; /* for compiler */
5545 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5547 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5549 first_char = arg[0] = arg0 & 0x7f;
5552 if (first_char == '#' /* ${#... */
5553 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5555 /* It must be length operator: ${#var} */
5559 /* Maybe handle parameter expansion */
5560 if (exp_saveptr /* if 2nd char is one of expansion operators */
5561 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5563 /* ${?:0}, ${#[:]%0} etc */
5564 exp_saveptr = var + 1;
5566 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5567 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5569 exp_op = exp_save = *exp_saveptr;
5571 exp_word = exp_saveptr + 1;
5572 if (exp_op == ':') {
5573 exp_op = *exp_word++;
5574 //TODO: try ${var:} and ${var:bogus} in non-bash config
5576 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5578 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5583 *exp_saveptr = '\0';
5584 } /* else: it's not an expansion op, but bare ${var} */
5587 /* Look up the variable in question */
5588 if (isdigit(var[0])) {
5589 /* parse_dollar should have vetted var for us */
5590 int n = xatoi_positive(var);
5591 if (n < G.global_argc)
5592 val = G.global_argv[n];
5593 /* else val remains NULL: $N with too big N */
5597 val = utoa(G.root_pid);
5599 case '!': /* bg pid */
5600 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5602 case '?': /* exitcode */
5603 val = utoa(G.last_exitcode);
5605 case '#': /* argc */
5606 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5609 val = get_local_var_value(var);
5613 /* Handle any expansions */
5614 if (exp_op == 'L') {
5615 reinit_unicode_for_hush();
5616 debug_printf_expand("expand: length(%s)=", val);
5617 val = utoa(val ? unicode_strlen(val) : 0);
5618 debug_printf_expand("%s\n", val);
5619 } else if (exp_op) {
5620 if (exp_op == '%' || exp_op == '#') {
5621 /* Standard-mandated substring removal ops:
5622 * ${parameter%word} - remove smallest suffix pattern
5623 * ${parameter%%word} - remove largest suffix pattern
5624 * ${parameter#word} - remove smallest prefix pattern
5625 * ${parameter##word} - remove largest prefix pattern
5627 * Word is expanded to produce a glob pattern.
5628 * Then var's value is matched to it and matching part removed.
5630 if (val && val[0]) {
5634 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5635 if (exp_op == *exp_word) /* ## or %% */
5637 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5639 exp_word = exp_exp_word;
5640 /* HACK ALERT. We depend here on the fact that
5641 * G.global_argv and results of utoa and get_local_var_value
5642 * are actually in writable memory:
5643 * scan_and_match momentarily stores NULs there. */
5645 loc = scan_and_match(t, exp_word, scan_flags);
5646 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5647 // exp_op, t, exp_word, loc);
5649 if (loc) { /* match was found */
5650 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5651 val = loc; /* take right part */
5653 val = to_be_freed = xstrndup(val, loc - val); /* left */
5657 #if BASH_PATTERN_SUBST
5658 else if (exp_op == '/' || exp_op == '\\') {
5659 /* It's ${var/[/]pattern[/repl]} thing.
5660 * Note that in encoded form it has TWO parts:
5661 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5662 * and if // is used, it is encoded as \:
5663 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5665 /* Empty variable always gives nothing: */
5666 // "v=''; echo ${v/*/w}" prints "", not "w"
5667 if (val && val[0]) {
5668 /* pattern uses non-standard expansion.
5669 * repl should be unbackslashed and globbed
5670 * by the usual expansion rules:
5672 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5673 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5674 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5675 * v='a bz'; echo ${v/a*z/\z} prints "z"
5676 * (note that a*z _pattern_ is never globbed!)
5678 char *pattern, *repl, *t;
5679 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5681 pattern = xstrdup(exp_word);
5682 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5683 *p++ = SPECIAL_VAR_SYMBOL;
5685 p = strchr(p, SPECIAL_VAR_SYMBOL);
5687 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5688 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5689 /* HACK ALERT. We depend here on the fact that
5690 * G.global_argv and results of utoa and get_local_var_value
5691 * are actually in writable memory:
5692 * replace_pattern momentarily stores NULs there. */
5694 to_be_freed = replace_pattern(t,
5696 (repl ? repl : exp_word),
5698 if (to_be_freed) /* at least one replace happened */
5704 #endif /* BASH_PATTERN_SUBST */
5705 else if (exp_op == ':') {
5706 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5707 /* It's ${var:N[:M]} bashism.
5708 * Note that in encoded form it has TWO parts:
5709 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5714 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5717 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5718 *p++ = SPECIAL_VAR_SYMBOL;
5720 p = strchr(p, SPECIAL_VAR_SYMBOL);
5722 len = expand_and_evaluate_arith(exp_word, &errmsg);
5725 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5728 /* negative beg counts from the end */
5729 beg = (arith_t)strlen(val) + beg;
5730 if (beg < 0) /* ${v: -999999} is "" */
5733 debug_printf_varexp("from val:'%s'\n", val);
5734 if (len == 0 || !val || beg >= strlen(val)) {
5738 /* Paranoia. What if user entered 9999999999999
5739 * which fits in arith_t but not int? */
5742 val = to_be_freed = xstrndup(val + beg, len);
5744 debug_printf_varexp("val:'%s'\n", val);
5746 //TODO: in bash, len=-n means strlen()-n
5747 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5749 die_if_script("malformed ${%s:...}", var);
5752 } else { /* one of "-=+?" */
5753 /* Standard-mandated substitution ops:
5754 * ${var?word} - indicate error if unset
5755 * If var is unset, word (or a message indicating it is unset
5756 * if word is null) is written to standard error
5757 * and the shell exits with a non-zero exit status.
5758 * Otherwise, the value of var is substituted.
5759 * ${var-word} - use default value
5760 * If var is unset, word is substituted.
5761 * ${var=word} - assign and use default value
5762 * If var is unset, word is assigned to var.
5763 * In all cases, final value of var is substituted.
5764 * ${var+word} - use alternative value
5765 * If var is unset, null is substituted.
5766 * Otherwise, word is substituted.
5768 * Word is subjected to tilde expansion, parameter expansion,
5769 * command substitution, and arithmetic expansion.
5770 * If word is not needed, it is not expanded.
5772 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5773 * but also treat null var as if it is unset.
5775 int use_word = (!val || ((exp_save == ':') && !val[0]));
5777 use_word = !use_word;
5778 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5779 (exp_save == ':') ? "true" : "false", use_word);
5781 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5783 exp_word = to_be_freed;
5784 if (exp_op == '?') {
5785 /* mimic bash message */
5786 die_if_script("%s: %s",
5788 exp_word[0] ? exp_word : "parameter null or not set"
5790 //TODO: how interactive bash aborts expansion mid-command?
5795 if (exp_op == '=') {
5796 /* ${var=[word]} or ${var:=[word]} */
5797 if (isdigit(var[0]) || var[0] == '#') {
5798 /* mimic bash message */
5799 die_if_script("$%s: cannot assign in this way", var);
5802 char *new_var = xasprintf("%s=%s", var, val);
5803 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5807 } /* one of "-=+?" */
5809 *exp_saveptr = exp_save;
5815 *to_be_freed_pp = to_be_freed;
5819 /* Expand all variable references in given string, adding words to list[]
5820 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5821 * to be filled). This routine is extremely tricky: has to deal with
5822 * variables/parameters with whitespace, $* and $@, and constructs like
5823 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5824 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5826 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5827 * expansion of right-hand side of assignment == 1-element expand.
5829 char cant_be_null = 0; /* only bit 0x80 matters */
5830 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5833 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5834 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5835 debug_print_list("expand_vars_to_list", output, n);
5836 n = o_save_ptr(output, n);
5837 debug_print_list("expand_vars_to_list[0]", output, n);
5839 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5841 char *to_be_freed = NULL;
5842 const char *val = NULL;
5843 #if ENABLE_HUSH_TICK
5844 o_string subst_result = NULL_O_STRING;
5846 #if ENABLE_FEATURE_SH_MATH
5847 char arith_buf[sizeof(arith_t)*3 + 2];
5851 o_addchr(output, '\0');
5852 n = o_save_ptr(output, n);
5856 o_addblock(output, arg, p - arg);
5857 debug_print_list("expand_vars_to_list[1]", output, n);
5859 p = strchr(p, SPECIAL_VAR_SYMBOL);
5861 /* Fetch special var name (if it is indeed one of them)
5862 * and quote bit, force the bit on if singleword expansion -
5863 * important for not getting v=$@ expand to many words. */
5864 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5866 /* Is this variable quoted and thus expansion can't be null?
5867 * "$@" is special. Even if quoted, it can still
5868 * expand to nothing (not even an empty string),
5869 * thus it is excluded. */
5870 if ((first_ch & 0x7f) != '@')
5871 cant_be_null |= first_ch;
5873 switch (first_ch & 0x7f) {
5874 /* Highest bit in first_ch indicates that var is double-quoted */
5878 if (!G.global_argv[1])
5881 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5882 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5883 while (G.global_argv[i]) {
5884 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5885 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5886 if (G.global_argv[i++][0] && G.global_argv[i]) {
5887 /* this argv[] is not empty and not last:
5888 * put terminating NUL, start new word */
5889 o_addchr(output, '\0');
5890 debug_print_list("expand_vars_to_list[2]", output, n);
5891 n = o_save_ptr(output, n);
5892 debug_print_list("expand_vars_to_list[3]", output, n);
5896 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5897 * and in this case should treat it like '$*' - see 'else...' below */
5898 if (first_ch == ('@'|0x80) /* quoted $@ */
5899 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5902 o_addQstr(output, G.global_argv[i]);
5903 if (++i >= G.global_argc)
5905 o_addchr(output, '\0');
5906 debug_print_list("expand_vars_to_list[4]", output, n);
5907 n = o_save_ptr(output, n);
5909 } else { /* quoted $* (or v="$@" case): add as one word */
5911 o_addQstr(output, G.global_argv[i]);
5912 if (!G.global_argv[++i])
5915 o_addchr(output, G.ifs[0]);
5917 output->has_quoted_part = 1;
5921 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5922 /* "Empty variable", used to make "" etc to not disappear */
5923 output->has_quoted_part = 1;
5925 cant_be_null = 0x80;
5927 #if ENABLE_HUSH_TICK
5928 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5929 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5931 /* Can't just stuff it into output o_string,
5932 * expanded result may need to be globbed
5934 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5935 G.last_exitcode = process_command_subs(&subst_result, arg);
5936 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5937 val = subst_result.data;
5940 #if ENABLE_FEATURE_SH_MATH
5941 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5944 arg++; /* skip '+' */
5945 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5946 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5947 res = expand_and_evaluate_arith(arg, NULL);
5948 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5949 sprintf(arith_buf, ARITH_FMT, res);
5955 val = expand_one_var(&to_be_freed, arg, &p);
5956 IF_HUSH_TICK(store_val:)
5957 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5958 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5959 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5960 if (val && val[0]) {
5961 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5964 } else { /* quoted $VAR, val will be appended below */
5965 output->has_quoted_part = 1;
5966 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5967 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5970 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5972 if (val && val[0]) {
5973 o_addQstr(output, val);
5977 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5978 * Do the check to avoid writing to a const string. */
5979 if (*p != SPECIAL_VAR_SYMBOL)
5980 *p = SPECIAL_VAR_SYMBOL;
5982 #if ENABLE_HUSH_TICK
5983 o_free(&subst_result);
5986 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5990 o_addchr(output, '\0');
5991 n = o_save_ptr(output, n);
5993 debug_print_list("expand_vars_to_list[a]", output, n);
5994 /* this part is literal, and it was already pre-quoted
5995 * if needed (much earlier), do not use o_addQstr here! */
5996 o_addstr_with_NUL(output, arg);
5997 debug_print_list("expand_vars_to_list[b]", output, n);
5998 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5999 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6002 /* allow to reuse list[n] later without re-growth */
6003 output->has_empty_slot = 1;
6005 o_addchr(output, '\0');
6011 static char **expand_variables(char **argv, unsigned expflags)
6015 o_string output = NULL_O_STRING;
6017 output.o_expflags = expflags;
6021 n = expand_vars_to_list(&output, n, *argv);
6024 debug_print_list("expand_variables", &output, n);
6026 /* output.data (malloced in one block) gets returned in "list" */
6027 list = o_finalize_list(&output, n);
6028 debug_print_strings("expand_variables[1]", list);
6032 static char **expand_strvec_to_strvec(char **argv)
6034 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6038 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6040 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6044 /* Used for expansion of right hand of assignments,
6045 * $((...)), heredocs, variable espansion parts.
6047 * NB: should NOT do globbing!
6048 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6050 static char *expand_string_to_string(const char *str, int do_unbackslash)
6052 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6053 const int do_unbackslash = 1;
6055 char *argv[2], **list;
6057 debug_printf_expand("string_to_string<='%s'\n", str);
6058 /* This is generally an optimization, but it also
6059 * handles "", which otherwise trips over !list[0] check below.
6060 * (is this ever happens that we actually get str="" here?)
6062 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6063 //TODO: Can use on strings with \ too, just unbackslash() them?
6064 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6065 return xstrdup(str);
6068 argv[0] = (char*)str;
6070 list = expand_variables(argv, do_unbackslash
6071 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6072 : EXP_FLAG_SINGLEWORD
6075 if (!list[0] || list[1])
6076 bb_error_msg_and_die("BUG in varexp2");
6077 /* actually, just move string 2*sizeof(char*) bytes back */
6078 overlapping_strcpy((char*)list, list[0]);
6080 unbackslash((char*)list);
6081 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6085 /* Used for "eval" builtin and case string */
6086 static char* expand_strvec_to_string(char **argv)
6090 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6091 /* Convert all NULs to spaces */
6096 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6097 bb_error_msg_and_die("BUG in varexp3");
6098 /* bash uses ' ' regardless of $IFS contents */
6103 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6104 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6108 static char **expand_assignments(char **argv, int count)
6113 G.expanded_assignments = p = NULL;
6114 /* Expand assignments into one string each */
6115 for (i = 0; i < count; i++) {
6116 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6118 G.expanded_assignments = NULL;
6123 static void switch_off_special_sigs(unsigned mask)
6126 while ((mask >>= 1) != 0) {
6130 #if ENABLE_HUSH_TRAP
6132 if (G_traps[sig] && !G_traps[sig][0])
6133 /* trap is '', has to remain SIG_IGN */
6136 G_traps[sig] = NULL;
6139 /* We are here only if no trap or trap was not '' */
6140 install_sighandler(sig, SIG_DFL);
6146 void re_execute_shell(char ***to_free, const char *s,
6147 char *g_argv0, char **g_argv,
6148 char **builtin_argv) NORETURN;
6150 static void reset_traps_to_defaults(void)
6152 /* This function is always called in a child shell
6153 * after fork (not vfork, NOMMU doesn't use this function).
6155 IF_HUSH_TRAP(unsigned sig;)
6158 /* Child shells are not interactive.
6159 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6160 * Testcase: (while :; do :; done) + ^Z should background.
6161 * Same goes for SIGTERM, SIGHUP, SIGINT.
6163 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6164 if (!G_traps && !mask)
6165 return; /* already no traps and no special sigs */
6167 /* Switch off special sigs */
6168 switch_off_special_sigs(mask);
6169 # if ENABLE_HUSH_JOB
6170 G_fatal_sig_mask = 0;
6172 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6173 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6174 * remain set in G.special_sig_mask */
6176 # if ENABLE_HUSH_TRAP
6180 /* Reset all sigs to default except ones with empty traps */
6181 for (sig = 0; sig < NSIG; sig++) {
6183 continue; /* no trap: nothing to do */
6184 if (!G_traps[sig][0])
6185 continue; /* empty trap: has to remain SIG_IGN */
6186 /* sig has non-empty trap, reset it: */
6188 G_traps[sig] = NULL;
6189 /* There is no signal for trap 0 (EXIT) */
6192 install_sighandler(sig, pick_sighandler(sig));
6199 static void re_execute_shell(char ***to_free, const char *s,
6200 char *g_argv0, char **g_argv,
6201 char **builtin_argv) NORETURN;
6202 static void re_execute_shell(char ***to_free, const char *s,
6203 char *g_argv0, char **g_argv,
6204 char **builtin_argv)
6206 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6207 /* delims + 2 * (number of bytes in printed hex numbers) */
6208 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6209 char *heredoc_argv[4];
6210 struct variable *cur;
6211 # if ENABLE_HUSH_FUNCTIONS
6212 struct function *funcp;
6216 unsigned long long empty_trap_mask;
6218 if (!g_argv0) { /* heredoc */
6219 argv = heredoc_argv;
6220 argv[0] = (char *) G.argv0_for_re_execing;
6221 argv[1] = (char *) "-<";
6222 argv[2] = (char *) s;
6224 pp = &argv[3]; /* used as pointer to empty environment */
6230 if (pp) while (*pp++)
6233 empty_trap_mask = 0;
6236 for (sig = 1; sig < NSIG; sig++) {
6237 if (G_traps[sig] && !G_traps[sig][0])
6238 empty_trap_mask |= 1LL << sig;
6242 sprintf(param_buf, NOMMU_HACK_FMT
6243 , (unsigned) G.root_pid
6244 , (unsigned) G.root_ppid
6245 , (unsigned) G.last_bg_pid
6246 , (unsigned) G.last_exitcode
6249 IF_HUSH_LOOPS(, G.depth_of_loop)
6251 # undef NOMMU_HACK_FMT
6252 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6253 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6256 for (cur = G.top_var; cur; cur = cur->next) {
6257 if (!cur->flg_export || cur->flg_read_only)
6260 # if ENABLE_HUSH_FUNCTIONS
6261 for (funcp = G.top_func; funcp; funcp = funcp->next)
6267 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6268 *pp++ = (char *) G.argv0_for_re_execing;
6270 for (cur = G.top_var; cur; cur = cur->next) {
6271 if (strcmp(cur->varstr, hush_version_str) == 0)
6273 if (cur->flg_read_only) {
6274 *pp++ = (char *) "-R";
6275 *pp++ = cur->varstr;
6276 } else if (!cur->flg_export) {
6277 *pp++ = (char *) "-V";
6278 *pp++ = cur->varstr;
6281 # if ENABLE_HUSH_FUNCTIONS
6282 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6283 *pp++ = (char *) "-F";
6284 *pp++ = funcp->name;
6285 *pp++ = funcp->body_as_string;
6288 /* We can pass activated traps here. Say, -Tnn:trap_string
6290 * However, POSIX says that subshells reset signals with traps
6292 * I tested bash-3.2 and it not only does that with true subshells
6293 * of the form ( list ), but with any forked children shells.
6294 * I set trap "echo W" WINCH; and then tried:
6296 * { echo 1; sleep 20; echo 2; } &
6297 * while true; do echo 1; sleep 20; echo 2; break; done &
6298 * true | { echo 1; sleep 20; echo 2; } | cat
6300 * In all these cases sending SIGWINCH to the child shell
6301 * did not run the trap. If I add trap "echo V" WINCH;
6302 * _inside_ group (just before echo 1), it works.
6304 * I conclude it means we don't need to pass active traps here.
6306 *pp++ = (char *) "-c";
6309 while (*++builtin_argv)
6310 *pp++ = *builtin_argv;
6311 *pp++ = (char *) "";
6316 /* *pp = NULL; - is already there */
6320 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6321 /* Don't propagate SIG_IGN to the child */
6322 if (SPECIAL_JOBSTOP_SIGS != 0)
6323 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6324 execve(bb_busybox_exec_path, argv, pp);
6325 /* Fallback. Useful for init=/bin/hush usage etc */
6326 if (argv[0][0] == '/')
6327 execve(argv[0], argv, pp);
6328 xfunc_error_retval = 127;
6329 bb_error_msg_and_die("can't re-execute the shell");
6331 #endif /* !BB_MMU */
6334 static int run_and_free_list(struct pipe *pi);
6336 /* Executing from string: eval, sh -c '...'
6337 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6338 * end_trigger controls how often we stop parsing
6339 * NUL: parse all, execute, return
6340 * ';': parse till ';' or newline, execute, repeat till EOF
6342 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6344 /* Why we need empty flag?
6345 * An obscure corner case "false; ``; echo $?":
6346 * empty command in `` should still set $? to 0.
6347 * But we can't just set $? to 0 at the start,
6348 * this breaks "false; echo `echo $?`" case.
6352 struct pipe *pipe_list;
6354 #if ENABLE_HUSH_INTERACTIVE
6355 if (end_trigger == ';')
6356 inp->promptmode = 0; /* PS1 */
6358 pipe_list = parse_stream(NULL, inp, end_trigger);
6359 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6360 /* If we are in "big" script
6361 * (not in `cmd` or something similar)...
6363 if (pipe_list == ERR_PTR && end_trigger == ';') {
6364 /* Discard cached input (rest of line) */
6365 int ch = inp->last_char;
6366 while (ch != EOF && ch != '\n') {
6367 //bb_error_msg("Discarded:'%c'", ch);
6372 /* This stream isn't empty */
6376 if (!pipe_list && empty)
6377 G.last_exitcode = 0;
6380 debug_print_tree(pipe_list, 0);
6381 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6382 run_and_free_list(pipe_list);
6384 if (G_flag_return_in_progress == 1)
6389 static void parse_and_run_string(const char *s)
6391 struct in_str input;
6392 setup_string_in_str(&input, s);
6393 parse_and_run_stream(&input, '\0');
6396 static void parse_and_run_file(FILE *f)
6398 struct in_str input;
6399 setup_file_in_str(&input, f);
6400 parse_and_run_stream(&input, ';');
6403 #if ENABLE_HUSH_TICK
6404 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6409 char **to_free = NULL;
6413 pid = BB_MMU ? xfork() : xvfork();
6414 if (pid == 0) { /* child */
6415 disable_restore_tty_pgrp_on_exit();
6416 /* Process substitution is not considered to be usual
6417 * 'command execution'.
6418 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6425 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6426 close(channel[0]); /* NB: close _first_, then move fd! */
6427 xmove_fd(channel[1], 1);
6428 /* Prevent it from trying to handle ctrl-z etc */
6429 IF_HUSH_JOB(G.run_list_level = 1;)
6430 # if ENABLE_HUSH_TRAP
6431 /* Awful hack for `trap` or $(trap).
6433 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6434 * contains an example where "trap" is executed in a subshell:
6436 * save_traps=$(trap)
6438 * eval "$save_traps"
6440 * Standard does not say that "trap" in subshell shall print
6441 * parent shell's traps. It only says that its output
6442 * must have suitable form, but then, in the above example
6443 * (which is not supposed to be normative), it implies that.
6445 * bash (and probably other shell) does implement it
6446 * (traps are reset to defaults, but "trap" still shows them),
6447 * but as a result, "trap" logic is hopelessly messed up:
6450 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6451 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6452 * # true | trap <--- trap is in subshell - no output (ditto)
6453 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6454 * trap -- 'echo Ho' SIGWINCH
6455 * # echo `(trap)` <--- in subshell in subshell - output
6456 * trap -- 'echo Ho' SIGWINCH
6457 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6458 * trap -- 'echo Ho' SIGWINCH
6460 * The rules when to forget and when to not forget traps
6461 * get really complex and nonsensical.
6463 * Our solution: ONLY bare $(trap) or `trap` is special.
6465 s = skip_whitespace(s);
6466 if (is_prefixed_with(s, "trap")
6467 && skip_whitespace(s + 4)[0] == '\0'
6469 static const char *const argv[] = { NULL, NULL };
6470 builtin_trap((char**)argv);
6471 fflush_all(); /* important */
6476 reset_traps_to_defaults();
6477 parse_and_run_string(s);
6478 _exit(G.last_exitcode);
6480 /* We re-execute after vfork on NOMMU. This makes this script safe:
6481 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6482 * huge=`cat BIG` # was blocking here forever
6485 re_execute_shell(&to_free,
6495 # if ENABLE_HUSH_FAST
6497 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6498 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6499 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6501 enable_restore_tty_pgrp_on_exit();
6506 return remember_FILE(xfdopen_for_read(channel[0]));
6509 /* Return code is exit status of the process that is run. */
6510 static int process_command_subs(o_string *dest, const char *s)
6513 struct in_str pipe_str;
6515 int status, ch, eol_cnt;
6517 fp = generate_stream_from_string(s, &pid);
6519 /* Now send results of command back into original context */
6520 setup_file_in_str(&pipe_str, fp);
6522 while ((ch = i_getch(&pipe_str)) != EOF) {
6528 o_addchr(dest, '\n');
6531 o_addQchr(dest, ch);
6534 debug_printf("done reading from `cmd` pipe, closing it\n");
6535 fclose_and_forget(fp);
6536 /* We need to extract exitcode. Test case
6537 * "true; echo `sleep 1; false` $?"
6539 safe_waitpid(pid, &status, 0);
6540 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6541 return WEXITSTATUS(status);
6543 #endif /* ENABLE_HUSH_TICK */
6546 static void setup_heredoc(struct redir_struct *redir)
6548 struct fd_pair pair;
6551 /* the _body_ of heredoc (misleading field name) */
6552 const char *heredoc = redir->rd_filename;
6559 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6560 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6564 len = strlen(heredoc);
6566 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6568 xmove_fd(pair.rd, redir->rd_fd);
6570 /* Try writing without forking. Newer kernels have
6571 * dynamically growing pipes. Must use non-blocking write! */
6574 written = write(pair.wr, heredoc, len);
6585 ndelay_off(pair.wr);
6587 /* Okay, pipe buffer was not big enough */
6588 /* Note: we must not create a stray child (bastard? :)
6589 * for the unsuspecting parent process. Child creates a grandchild
6590 * and exits before parent execs the process which consumes heredoc
6591 * (that exec happens after we return from this function) */
6598 disable_restore_tty_pgrp_on_exit();
6599 pid = BB_MMU ? xfork() : xvfork();
6603 close(redir->rd_fd); /* read side of the pipe */
6605 full_write(pair.wr, heredoc, len); /* may loop or block */
6608 /* Delegate blocking writes to another process */
6609 xmove_fd(pair.wr, STDOUT_FILENO);
6610 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6614 #if ENABLE_HUSH_FAST
6616 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6618 enable_restore_tty_pgrp_on_exit();
6624 wait(NULL); /* wait till child has died */
6630 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6631 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6634 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6638 if (sq) while (sq[i].orig_fd >= 0) {
6639 /* If we collide with an already moved fd... */
6640 if (fd == sq[i].moved_to) {
6641 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6642 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6643 if (sq[i].moved_to < 0) /* what? */
6647 if (fd == sq[i].orig_fd) {
6648 /* Example: echo Hello >/dev/null 1>&2 */
6649 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6655 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6657 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6658 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6659 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6660 if (sq[i].moved_to < 0 && errno != EBADF)
6662 sq[i+1].orig_fd = -1; /* end marker */
6666 /* fd: redirect wants this fd to be used (e.g. 3>file).
6667 * Move all conflicting internally used fds,
6668 * and remember them so that we can restore them later.
6670 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6672 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6675 #if ENABLE_HUSH_INTERACTIVE
6676 if (fd != 0 && fd == G.interactive_fd) {
6677 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6678 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6679 return 1; /* "we closed fd" */
6682 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6683 * (1) Redirect in a forked child. No need to save FILEs' fds,
6684 * we aren't going to use them anymore, ok to trash.
6685 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6686 * but how are we doing to restore them?
6687 * "fileno(fd) = new_fd" can't be done.
6692 /* If this one of script's fds? */
6693 if (save_FILEs_on_redirect(fd, avoid_fd))
6694 return 1; /* yes. "we closed fd" */
6696 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6697 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6698 return 0; /* "we did not close fd" */
6701 static void restore_redirects(struct squirrel *sq)
6706 while (sq[i].orig_fd >= 0) {
6707 if (sq[i].moved_to >= 0) {
6708 /* We simply die on error */
6709 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6710 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6712 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6713 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6714 close(sq[i].orig_fd);
6721 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6723 restore_redirected_FILEs();
6726 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6727 * and stderr if they are redirected. */
6728 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6731 struct redir_struct *redir;
6733 for (redir = prog->redirects; redir; redir = redir->next) {
6734 if (redir->rd_type == REDIRECT_HEREDOC2) {
6735 /* "rd_fd<<HERE" case */
6736 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6737 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6739 debug_printf_parse("set heredoc '%s'\n",
6740 redir->rd_filename);
6741 setup_heredoc(redir);
6745 if (redir->rd_dup == REDIRFD_TO_FILE) {
6746 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6748 if (redir->rd_filename == NULL) {
6751 * "cmd >" (no filename)
6752 * "cmd > <file" (2nd redirect starts too early)
6754 die_if_script("syntax error: %s", "invalid redirect");
6757 mode = redir_table[redir->rd_type].mode;
6758 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6759 openfd = open_or_warn(p, mode);
6762 /* Error message from open_or_warn can be lost
6763 * if stderr has been redirected, but bash
6764 * and ash both lose it as well
6765 * (though zsh doesn't!)
6770 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6771 openfd = redir->rd_dup;
6774 if (openfd != redir->rd_fd) {
6775 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6776 if (openfd == REDIRFD_CLOSE) {
6777 /* "rd_fd >&-" means "close me" */
6779 /* ^^^ optimization: saving may already
6780 * have closed it. If not... */
6781 close(redir->rd_fd);
6784 xdup2(openfd, redir->rd_fd);
6785 if (redir->rd_dup == REDIRFD_TO_FILE)
6786 /* "rd_fd > FILE" */
6788 /* else: "rd_fd > rd_dup" */
6795 static char *find_in_path(const char *arg)
6798 const char *PATH = get_local_var_value("PATH");
6804 const char *end = strchrnul(PATH, ':');
6805 int sz = end - PATH; /* must be int! */
6809 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6811 /* We have xxx::yyyy in $PATH,
6812 * it means "use current dir" */
6815 if (access(ret, F_OK) == 0)
6828 static const struct built_in_command *find_builtin_helper(const char *name,
6829 const struct built_in_command *x,
6830 const struct built_in_command *end)
6833 if (strcmp(name, x->b_cmd) != 0) {
6837 debug_printf_exec("found builtin '%s'\n", name);
6842 static const struct built_in_command *find_builtin1(const char *name)
6844 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6846 static const struct built_in_command *find_builtin(const char *name)
6848 const struct built_in_command *x = find_builtin1(name);
6851 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6854 #if ENABLE_HUSH_FUNCTIONS
6855 static struct function **find_function_slot(const char *name)
6857 struct function **funcpp = &G.top_func;
6859 if (strcmp(name, (*funcpp)->name) == 0) {
6862 funcpp = &(*funcpp)->next;
6867 static const struct function *find_function(const char *name)
6869 const struct function *funcp = *find_function_slot(name);
6871 debug_printf_exec("found function '%s'\n", name);
6875 /* Note: takes ownership on name ptr */
6876 static struct function *new_function(char *name)
6878 struct function **funcpp = find_function_slot(name);
6879 struct function *funcp = *funcpp;
6881 if (funcp != NULL) {
6882 struct command *cmd = funcp->parent_cmd;
6883 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6885 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6887 /* Note: if !funcp->body, do not free body_as_string!
6888 * This is a special case of "-F name body" function:
6889 * body_as_string was not malloced! */
6891 free_pipe_list(funcp->body);
6893 free(funcp->body_as_string);
6897 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6898 cmd->argv[0] = funcp->name;
6899 cmd->group = funcp->body;
6901 cmd->group_as_string = funcp->body_as_string;
6905 debug_printf_exec("remembering new function '%s'\n", name);
6906 funcp = *funcpp = xzalloc(sizeof(*funcp));
6907 /*funcp->next = NULL;*/
6914 # if ENABLE_HUSH_UNSET
6915 static void unset_func(const char *name)
6917 struct function **funcpp = find_function_slot(name);
6918 struct function *funcp = *funcpp;
6920 if (funcp != NULL) {
6921 debug_printf_exec("freeing function '%s'\n", funcp->name);
6922 *funcpp = funcp->next;
6923 /* funcp is unlinked now, deleting it.
6924 * Note: if !funcp->body, the function was created by
6925 * "-F name body", do not free ->body_as_string
6926 * and ->name as they were not malloced. */
6928 free_pipe_list(funcp->body);
6931 free(funcp->body_as_string);
6940 #define exec_function(to_free, funcp, argv) \
6941 exec_function(funcp, argv)
6943 static void exec_function(char ***to_free,
6944 const struct function *funcp,
6945 char **argv) NORETURN;
6946 static void exec_function(char ***to_free,
6947 const struct function *funcp,
6953 argv[0] = G.global_argv[0];
6954 G.global_argv = argv;
6955 G.global_argc = n = 1 + string_array_len(argv + 1);
6956 /* On MMU, funcp->body is always non-NULL */
6957 n = run_list(funcp->body);
6961 re_execute_shell(to_free,
6962 funcp->body_as_string,
6969 static int run_function(const struct function *funcp, char **argv)
6975 save_and_replace_G_args(&sv, argv);
6977 /* "we are in function, ok to use return" */
6978 sv_flg = G_flag_return_in_progress;
6979 G_flag_return_in_progress = -1;
6980 # if ENABLE_HUSH_LOCAL
6981 G.func_nest_level++;
6984 /* On MMU, funcp->body is always non-NULL */
6987 /* Function defined by -F */
6988 parse_and_run_string(funcp->body_as_string);
6989 rc = G.last_exitcode;
6993 rc = run_list(funcp->body);
6996 # if ENABLE_HUSH_LOCAL
6998 struct variable *var;
6999 struct variable **var_pp;
7001 var_pp = &G.top_var;
7002 while ((var = *var_pp) != NULL) {
7003 if (var->func_nest_level < G.func_nest_level) {
7004 var_pp = &var->next;
7008 if (var->flg_export)
7009 bb_unsetenv(var->varstr);
7010 /* Remove from global list */
7011 *var_pp = var->next;
7017 G.func_nest_level--;
7020 G_flag_return_in_progress = sv_flg;
7022 restore_G_args(&sv, argv);
7026 #endif /* ENABLE_HUSH_FUNCTIONS */
7030 #define exec_builtin(to_free, x, argv) \
7031 exec_builtin(x, argv)
7033 #define exec_builtin(to_free, x, argv) \
7034 exec_builtin(to_free, argv)
7036 static void exec_builtin(char ***to_free,
7037 const struct built_in_command *x,
7038 char **argv) NORETURN;
7039 static void exec_builtin(char ***to_free,
7040 const struct built_in_command *x,
7046 rcode = x->b_function(argv);
7051 /* On NOMMU, we must never block!
7052 * Example: { sleep 99 | read line; } & echo Ok
7054 re_execute_shell(to_free,
7063 static void execvp_or_die(char **argv) NORETURN;
7064 static void execvp_or_die(char **argv)
7067 debug_printf_exec("execing '%s'\n", argv[0]);
7068 /* Don't propagate SIG_IGN to the child */
7069 if (SPECIAL_JOBSTOP_SIGS != 0)
7070 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7071 execvp(argv[0], argv);
7073 if (errno == EACCES) e = 126;
7074 if (errno == ENOENT) e = 127;
7075 bb_perror_msg("can't execute '%s'", argv[0]);
7079 #if ENABLE_HUSH_MODE_X
7080 static void dump_cmd_in_x_mode(char **argv)
7082 if (G_x_mode && argv) {
7083 /* We want to output the line in one write op */
7091 len += strlen(argv[n++]) + 1;
7097 p += sprintf(p, " %s", argv[n++]);
7105 # define dump_cmd_in_x_mode(argv) ((void)0)
7109 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7110 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7111 #define pseudo_exec(nommu_save, command, argv_expanded) \
7112 pseudo_exec(command, argv_expanded)
7115 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7117 * Don't exit() here. If you don't exec, use _exit instead.
7118 * The at_exit handlers apparently confuse the calling process,
7119 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7121 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7122 char **argv, int assignment_cnt,
7123 char **argv_expanded) NORETURN;
7124 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7125 char **argv, int assignment_cnt,
7126 char **argv_expanded)
7130 new_env = expand_assignments(argv, assignment_cnt);
7131 dump_cmd_in_x_mode(new_env);
7133 if (!argv[assignment_cnt]) {
7134 /* Case when we are here: ... | var=val | ...
7135 * (note that we do not exit early, i.e., do not optimize out
7136 * expand_assignments(): think about ... | var=`sleep 1` | ...
7138 free_strings(new_env);
7139 _exit(EXIT_SUCCESS);
7143 set_vars_and_save_old(new_env);
7144 free(new_env); /* optional */
7145 /* we can also destroy set_vars_and_save_old's return value,
7148 nommu_save->new_env = new_env;
7149 nommu_save->old_vars = set_vars_and_save_old(new_env);
7152 if (argv_expanded) {
7153 argv = argv_expanded;
7155 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7157 nommu_save->argv = argv;
7160 dump_cmd_in_x_mode(argv);
7162 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7163 if (strchr(argv[0], '/') != NULL)
7167 /* Check if the command matches any of the builtins.
7168 * Depending on context, this might be redundant. But it's
7169 * easier to waste a few CPU cycles than it is to figure out
7170 * if this is one of those cases.
7173 /* On NOMMU, it is more expensive to re-execute shell
7174 * just in order to run echo or test builtin.
7175 * It's better to skip it here and run corresponding
7176 * non-builtin later. */
7177 const struct built_in_command *x;
7178 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7180 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7183 #if ENABLE_HUSH_FUNCTIONS
7184 /* Check if the command matches any functions */
7186 const struct function *funcp = find_function(argv[0]);
7188 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7193 #if ENABLE_FEATURE_SH_STANDALONE
7194 /* Check if the command matches any busybox applets */
7196 int a = find_applet_by_name(argv[0]);
7198 # if BB_MMU /* see above why on NOMMU it is not allowed */
7199 if (APPLET_IS_NOEXEC(a)) {
7200 /* Do not leak open fds from opened script files etc */
7201 close_all_FILE_list();
7202 debug_printf_exec("running applet '%s'\n", argv[0]);
7203 run_applet_no_and_exit(a, argv[0], argv);
7206 /* Re-exec ourselves */
7207 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7208 /* Don't propagate SIG_IGN to the child */
7209 if (SPECIAL_JOBSTOP_SIGS != 0)
7210 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7211 execv(bb_busybox_exec_path, argv);
7212 /* If they called chroot or otherwise made the binary no longer
7213 * executable, fall through */
7218 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7221 execvp_or_die(argv);
7224 /* Called after [v]fork() in run_pipe
7226 static void pseudo_exec(nommu_save_t *nommu_save,
7227 struct command *command,
7228 char **argv_expanded) NORETURN;
7229 static void pseudo_exec(nommu_save_t *nommu_save,
7230 struct command *command,
7231 char **argv_expanded)
7233 if (command->argv) {
7234 pseudo_exec_argv(nommu_save, command->argv,
7235 command->assignment_cnt, argv_expanded);
7238 if (command->group) {
7239 /* Cases when we are here:
7242 * ... | ( list ) | ...
7243 * ... | { list } | ...
7247 debug_printf_exec("pseudo_exec: run_list\n");
7248 reset_traps_to_defaults();
7249 rcode = run_list(command->group);
7250 /* OK to leak memory by not calling free_pipe_list,
7251 * since this process is about to exit */
7254 re_execute_shell(&nommu_save->argv_from_re_execing,
7255 command->group_as_string,
7262 /* Case when we are here: ... | >file */
7263 debug_printf_exec("pseudo_exec'ed null command\n");
7264 _exit(EXIT_SUCCESS);
7268 static const char *get_cmdtext(struct pipe *pi)
7274 /* This is subtle. ->cmdtext is created only on first backgrounding.
7275 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7276 * On subsequent bg argv is trashed, but we won't use it */
7280 argv = pi->cmds[0].argv;
7282 pi->cmdtext = xzalloc(1);
7287 len += strlen(*argv) + 1;
7291 argv = pi->cmds[0].argv;
7293 p = stpcpy(p, *argv);
7300 static void remove_job_from_table(struct pipe *pi)
7302 struct pipe *prev_pipe;
7304 if (pi == G.job_list) {
7305 G.job_list = pi->next;
7307 prev_pipe = G.job_list;
7308 while (prev_pipe->next != pi)
7309 prev_pipe = prev_pipe->next;
7310 prev_pipe->next = pi->next;
7314 G.last_jobid = G.job_list->jobid;
7317 static void delete_finished_job(struct pipe *pi)
7319 remove_job_from_table(pi);
7323 static void clean_up_last_dead_job(void)
7325 if (G.job_list && !G.job_list->alive_cmds)
7326 delete_finished_job(G.job_list);
7329 static void insert_job_into_table(struct pipe *pi)
7331 struct pipe *job, **jobp;
7334 clean_up_last_dead_job();
7336 /* Find the end of the list, and find next job ID to use */
7339 while ((job = *jobp) != NULL) {
7346 /* Create a new job struct at the end */
7347 job = *jobp = xmemdup(pi, sizeof(*pi));
7349 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7350 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7351 for (i = 0; i < pi->num_cmds; i++) {
7352 job->cmds[i].pid = pi->cmds[i].pid;
7353 /* all other fields are not used and stay zero */
7355 job->cmdtext = xstrdup(get_cmdtext(pi));
7357 if (G_interactive_fd)
7358 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7359 G.last_jobid = job->jobid;
7363 static int job_exited_or_stopped(struct pipe *pi)
7367 if (pi->alive_cmds != pi->stopped_cmds)
7370 /* All processes in fg pipe have exited or stopped */
7374 rcode = pi->cmds[i].cmd_exitcode;
7375 /* usually last process gives overall exitstatus,
7376 * but with "set -o pipefail", last *failed* process does */
7377 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7380 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7384 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7391 dead = WIFEXITED(status) || WIFSIGNALED(status);
7394 if (WIFSTOPPED(status))
7395 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7396 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7397 if (WIFSIGNALED(status))
7398 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7399 childpid, WTERMSIG(status), WEXITSTATUS(status));
7400 if (WIFEXITED(status))
7401 debug_printf_jobs("pid %d exited, exitcode %d\n",
7402 childpid, WEXITSTATUS(status));
7404 /* Were we asked to wait for a fg pipe? */
7406 i = fg_pipe->num_cmds;
7411 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7412 if (fg_pipe->cmds[i].pid != childpid)
7416 fg_pipe->cmds[i].pid = 0;
7417 fg_pipe->alive_cmds--;
7418 ex = WEXITSTATUS(status);
7419 /* bash prints killer signal's name for *last*
7420 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7421 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7423 if (WIFSIGNALED(status)) {
7424 int sig = WTERMSIG(status);
7425 if (i == fg_pipe->num_cmds-1)
7426 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7427 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7428 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7429 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7430 * Maybe we need to use sig | 128? */
7433 fg_pipe->cmds[i].cmd_exitcode = ex;
7435 fg_pipe->stopped_cmds++;
7437 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7438 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7439 rcode = job_exited_or_stopped(fg_pipe);
7441 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7442 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7443 * and "killall -STOP cat" */
7444 if (G_interactive_fd) {
7446 if (fg_pipe->alive_cmds != 0)
7447 insert_job_into_table(fg_pipe);
7451 if (fg_pipe->alive_cmds == 0)
7454 /* There are still running processes in the fg_pipe */
7457 /* It wasn't in fg_pipe, look for process in bg pipes */
7461 /* We were asked to wait for bg or orphaned children */
7462 /* No need to remember exitcode in this case */
7463 for (pi = G.job_list; pi; pi = pi->next) {
7464 for (i = 0; i < pi->num_cmds; i++) {
7465 if (pi->cmds[i].pid == childpid)
7466 goto found_pi_and_prognum;
7469 /* Happens when shell is used as init process (init=/bin/sh) */
7470 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7471 return -1; /* this wasn't a process from fg_pipe */
7473 found_pi_and_prognum:
7476 int rcode = WEXITSTATUS(status);
7477 if (WIFSIGNALED(status))
7478 rcode = 128 + WTERMSIG(status);
7479 pi->cmds[i].cmd_exitcode = rcode;
7480 if (G.last_bg_pid == pi->cmds[i].pid)
7481 G.last_bg_pid_exitcode = rcode;
7482 pi->cmds[i].pid = 0;
7484 if (!pi->alive_cmds) {
7485 if (G_interactive_fd) {
7486 printf(JOB_STATUS_FORMAT, pi->jobid,
7487 "Done", pi->cmdtext);
7488 delete_finished_job(pi);
7491 * bash deletes finished jobs from job table only in interactive mode,
7492 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7493 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7494 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7495 * We only retain one "dead" job, if it's the single job on the list.
7496 * This covers most of real-world scenarios where this is useful.
7498 if (pi != G.job_list)
7499 delete_finished_job(pi);
7507 return -1; /* this wasn't a process from fg_pipe */
7510 /* Check to see if any processes have exited -- if they have,
7511 * figure out why and see if a job has completed.
7513 * If non-NULL fg_pipe: wait for its completion or stop.
7514 * Return its exitcode or zero if stopped.
7516 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7517 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7518 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7519 * or 0 if no children changed status.
7521 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7522 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7523 * or 0 if no children changed status.
7525 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7531 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7533 attributes = WUNTRACED;
7534 if (fg_pipe == NULL)
7535 attributes |= WNOHANG;
7538 #if ENABLE_HUSH_FAST
7539 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7540 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7541 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7542 /* There was neither fork nor SIGCHLD since last waitpid */
7543 /* Avoid doing waitpid syscall if possible */
7544 if (!G.we_have_children) {
7548 if (fg_pipe == NULL) { /* is WNOHANG set? */
7549 /* We have children, but they did not exit
7550 * or stop yet (we saw no SIGCHLD) */
7553 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7557 /* Do we do this right?
7558 * bash-3.00# sleep 20 | false
7560 * [3]+ Stopped sleep 20 | false
7561 * bash-3.00# echo $?
7562 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7563 * [hush 1.14.0: yes we do it right]
7567 #if ENABLE_HUSH_FAST
7569 i = G.count_SIGCHLD;
7571 childpid = waitpid(-1, &status, attributes);
7572 if (childpid <= 0) {
7573 if (childpid && errno != ECHILD)
7574 bb_perror_msg("waitpid");
7575 #if ENABLE_HUSH_FAST
7576 else { /* Until next SIGCHLD, waitpid's are useless */
7577 G.we_have_children = (childpid == 0);
7578 G.handled_SIGCHLD = i;
7579 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7582 /* ECHILD (no children), or 0 (no change in children status) */
7586 rcode = process_wait_result(fg_pipe, childpid, status);
7588 /* fg_pipe exited or stopped */
7591 if (childpid == waitfor_pid) {
7592 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7593 rcode = WEXITSTATUS(status);
7594 if (WIFSIGNALED(status))
7595 rcode = 128 + WTERMSIG(status);
7596 if (WIFSTOPPED(status))
7597 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7598 rcode = 128 + WSTOPSIG(status);
7600 break; /* "wait PID" called us, give it exitcode+1 */
7602 /* This wasn't one of our processes, or */
7603 /* fg_pipe still has running processes, do waitpid again */
7604 } /* while (waitpid succeeds)... */
7610 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7613 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7614 if (G_saved_tty_pgrp) {
7615 /* Job finished, move the shell to the foreground */
7616 p = getpgrp(); /* our process group id */
7617 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7618 tcsetpgrp(G_interactive_fd, p);
7624 /* Start all the jobs, but don't wait for anything to finish.
7627 * Return code is normally -1, when the caller has to wait for children
7628 * to finish to determine the exit status of the pipe. If the pipe
7629 * is a simple builtin command, however, the action is done by the
7630 * time run_pipe returns, and the exit code is provided as the
7633 * Returns -1 only if started some children. IOW: we have to
7634 * mask out retvals of builtins etc with 0xff!
7636 * The only case when we do not need to [v]fork is when the pipe
7637 * is single, non-backgrounded, non-subshell command. Examples:
7638 * cmd ; ... { list } ; ...
7639 * cmd && ... { list } && ...
7640 * cmd || ... { list } || ...
7641 * If it is, then we can run cmd as a builtin, NOFORK,
7642 * or (if SH_STANDALONE) an applet, and we can run the { list }
7643 * with run_list. If it isn't one of these, we fork and exec cmd.
7645 * Cases when we must fork:
7646 * non-single: cmd | cmd
7647 * backgrounded: cmd & { list } &
7648 * subshell: ( list ) [&]
7650 #if !ENABLE_HUSH_MODE_X
7651 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7652 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7654 static int redirect_and_varexp_helper(char ***new_env_p,
7655 struct variable **old_vars_p,
7656 struct command *command,
7657 struct squirrel **sqp,
7658 char **argv_expanded)
7660 /* setup_redirects acts on file descriptors, not FILEs.
7661 * This is perfect for work that comes after exec().
7662 * Is it really safe for inline use? Experimentally,
7663 * things seem to work. */
7664 int rcode = setup_redirects(command, sqp);
7666 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7667 *new_env_p = new_env;
7668 dump_cmd_in_x_mode(new_env);
7669 dump_cmd_in_x_mode(argv_expanded);
7671 *old_vars_p = set_vars_and_save_old(new_env);
7675 static NOINLINE int run_pipe(struct pipe *pi)
7677 static const char *const null_ptr = NULL;
7681 struct command *command;
7682 char **argv_expanded;
7684 struct squirrel *squirrel = NULL;
7687 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7690 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7691 * Result should be 3 lines: q w e, qwe, q w e
7693 G.ifs = get_local_var_value("IFS");
7697 IF_HUSH_JOB(pi->pgrp = -1;)
7698 pi->stopped_cmds = 0;
7699 command = &pi->cmds[0];
7700 argv_expanded = NULL;
7702 if (pi->num_cmds != 1
7703 || pi->followup == PIPE_BG
7704 || command->cmd_type == CMD_SUBSHELL
7711 debug_printf_exec(": group:%p argv:'%s'\n",
7712 command->group, command->argv ? command->argv[0] : "NONE");
7714 if (command->group) {
7715 #if ENABLE_HUSH_FUNCTIONS
7716 if (command->cmd_type == CMD_FUNCDEF) {
7717 /* "executing" func () { list } */
7718 struct function *funcp;
7720 funcp = new_function(command->argv[0]);
7721 /* funcp->name is already set to argv[0] */
7722 funcp->body = command->group;
7724 funcp->body_as_string = command->group_as_string;
7725 command->group_as_string = NULL;
7727 command->group = NULL;
7728 command->argv[0] = NULL;
7729 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7730 funcp->parent_cmd = command;
7731 command->child_func = funcp;
7733 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7735 return EXIT_SUCCESS;
7739 debug_printf("non-subshell group\n");
7740 rcode = 1; /* exitcode if redir failed */
7741 if (setup_redirects(command, &squirrel) == 0) {
7742 debug_printf_exec(": run_list\n");
7743 rcode = run_list(command->group) & 0xff;
7745 restore_redirects(squirrel);
7746 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7748 debug_printf_exec("run_pipe: return %d\n", rcode);
7752 argv = command->argv ? command->argv : (char **) &null_ptr;
7754 const struct built_in_command *x;
7755 #if ENABLE_HUSH_FUNCTIONS
7756 const struct function *funcp;
7760 char **new_env = NULL;
7761 struct variable *old_vars = NULL;
7763 if (argv[command->assignment_cnt] == NULL) {
7764 /* Assignments, but no command */
7765 /* Ensure redirects take effect (that is, create files).
7766 * Try "a=t >file" */
7767 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7768 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7769 /* Set shell variables */
7773 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7774 /* Do we need to flag set_local_var() errors?
7775 * "assignment to readonly var" and "putenv error"
7780 /* Redirect error sets $? to 1. Otherwise,
7781 * if evaluating assignment value set $?, retain it.
7782 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7784 rcode = G.last_exitcode;
7785 /* Exit, _skipping_ variable restoring code: */
7786 goto clean_up_and_ret0;
7788 #else /* Older, bigger, but more correct code */
7790 rcode = setup_redirects(command, &squirrel);
7791 restore_redirects(squirrel);
7792 /* Set shell variables */
7794 bb_putchar_stderr('+');
7796 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7798 fprintf(stderr, " %s", p);
7799 debug_printf_exec("set shell var:'%s'->'%s'\n",
7801 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7802 /* Do we need to flag set_local_var() errors?
7803 * "assignment to readonly var" and "putenv error"
7808 bb_putchar_stderr('\n');
7809 /* Redirect error sets $? to 1. Otherwise,
7810 * if evaluating assignment value set $?, retain it.
7811 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7813 rcode = G.last_exitcode;
7814 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7816 debug_printf_exec("run_pipe: return %d\n", rcode);
7821 /* Expand the rest into (possibly) many strings each */
7823 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7824 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7828 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7831 /* if someone gives us an empty string: `cmd with empty output` */
7832 if (!argv_expanded[0]) {
7833 free(argv_expanded);
7835 return G.last_exitcode;
7838 x = find_builtin(argv_expanded[0]);
7839 #if ENABLE_HUSH_FUNCTIONS
7842 funcp = find_function(argv_expanded[0]);
7846 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7847 debug_printf("exec with redirects only\n");
7848 rcode = setup_redirects(command, NULL);
7849 /* rcode=1 can be if redir file can't be opened */
7850 goto clean_up_and_ret1;
7853 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7856 debug_printf_exec(": builtin '%s' '%s'...\n",
7857 x->b_cmd, argv_expanded[1]);
7859 rcode = x->b_function(argv_expanded) & 0xff;
7862 #if ENABLE_HUSH_FUNCTIONS
7864 # if ENABLE_HUSH_LOCAL
7865 struct variable **sv;
7866 sv = G.shadowed_vars_pp;
7867 G.shadowed_vars_pp = &old_vars;
7869 debug_printf_exec(": function '%s' '%s'...\n",
7870 funcp->name, argv_expanded[1]);
7871 rcode = run_function(funcp, argv_expanded) & 0xff;
7872 # if ENABLE_HUSH_LOCAL
7873 G.shadowed_vars_pp = sv;
7879 unset_vars(new_env);
7881 /* clean_up_and_ret0: */
7882 restore_redirects(squirrel);
7884 free(argv_expanded);
7885 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7887 debug_printf_exec("run_pipe return %d\n", rcode);
7891 if (ENABLE_FEATURE_SH_NOFORK) {
7892 int n = find_applet_by_name(argv_expanded[0]);
7893 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7894 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7896 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7897 argv_expanded[0], argv_expanded[1]);
7898 rcode = run_nofork_applet(n, argv_expanded);
7900 goto clean_up_and_ret;
7903 /* It is neither builtin nor applet. We must fork. */
7907 /* NB: argv_expanded may already be created, and that
7908 * might include `cmd` runs! Do not rerun it! We *must*
7909 * use argv_expanded if it's non-NULL */
7911 /* Going to fork a child per each pipe member */
7916 while (cmd_no < pi->num_cmds) {
7917 struct fd_pair pipefds;
7919 volatile nommu_save_t nommu_save;
7920 nommu_save.new_env = NULL;
7921 nommu_save.old_vars = NULL;
7922 nommu_save.argv = NULL;
7923 nommu_save.argv_from_re_execing = NULL;
7925 command = &pi->cmds[cmd_no];
7927 if (command->argv) {
7928 debug_printf_exec(": pipe member '%s' '%s'...\n",
7929 command->argv[0], command->argv[1]);
7931 debug_printf_exec(": pipe member with no argv\n");
7934 /* pipes are inserted between pairs of commands */
7937 if (cmd_no < pi->num_cmds)
7938 xpiped_pair(pipefds);
7940 command->pid = BB_MMU ? fork() : vfork();
7941 if (!command->pid) { /* child */
7943 disable_restore_tty_pgrp_on_exit();
7944 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7946 /* Every child adds itself to new process group
7947 * with pgid == pid_of_first_child_in_pipe */
7948 if (G.run_list_level == 1 && G_interactive_fd) {
7951 if (pgrp < 0) /* true for 1st process only */
7953 if (setpgid(0, pgrp) == 0
7954 && pi->followup != PIPE_BG
7955 && G_saved_tty_pgrp /* we have ctty */
7957 /* We do it in *every* child, not just first,
7959 tcsetpgrp(G_interactive_fd, pgrp);
7963 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7964 /* 1st cmd in backgrounded pipe
7965 * should have its stdin /dev/null'ed */
7967 if (open(bb_dev_null, O_RDONLY))
7968 xopen("/", O_RDONLY);
7970 xmove_fd(next_infd, 0);
7972 xmove_fd(pipefds.wr, 1);
7975 /* Like bash, explicit redirects override pipes,
7976 * and the pipe fd (fd#1) is available for dup'ing:
7977 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7978 * of cmd1 goes into pipe.
7980 if (setup_redirects(command, NULL)) {
7981 /* Happens when redir file can't be opened:
7982 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7984 * hush: can't open '/qwe/rty': No such file or directory
7986 * (echo BAR is not executed, it hits _exit(1) below)
7991 /* Stores to nommu_save list of env vars putenv'ed
7992 * (NOMMU, on MMU we don't need that) */
7993 /* cast away volatility... */
7994 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7995 /* pseudo_exec() does not return */
7998 /* parent or error */
7999 #if ENABLE_HUSH_FAST
8001 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8003 enable_restore_tty_pgrp_on_exit();
8005 /* Clean up after vforked child */
8006 free(nommu_save.argv);
8007 free(nommu_save.argv_from_re_execing);
8008 unset_vars(nommu_save.new_env);
8009 add_vars(nommu_save.old_vars);
8011 free(argv_expanded);
8012 argv_expanded = NULL;
8013 if (command->pid < 0) { /* [v]fork failed */
8014 /* Clearly indicate, was it fork or vfork */
8015 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8019 /* Second and next children need to know pid of first one */
8021 pi->pgrp = command->pid;
8027 if (cmd_no < pi->num_cmds)
8029 /* Pass read (output) pipe end to next iteration */
8030 next_infd = pipefds.rd;
8033 if (!pi->alive_cmds) {
8035 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8040 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8044 /* NB: called by pseudo_exec, and therefore must not modify any
8045 * global data until exec/_exit (we can be a child after vfork!) */
8046 static int run_list(struct pipe *pi)
8048 #if ENABLE_HUSH_CASE
8049 char *case_word = NULL;
8051 #if ENABLE_HUSH_LOOPS
8052 struct pipe *loop_top = NULL;
8053 char **for_lcur = NULL;
8054 char **for_list = NULL;
8056 smallint last_followup;
8058 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8059 smalluint cond_code = 0;
8061 enum { cond_code = 0 };
8064 smallint rword; /* RES_foo */
8065 smallint last_rword; /* ditto */
8068 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8071 #if ENABLE_HUSH_LOOPS
8072 /* Check syntax for "for" */
8075 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8076 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8078 /* current word is FOR or IN (BOLD in comments below) */
8079 if (cpipe->next == NULL) {
8080 syntax_error("malformed for");
8082 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8085 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8086 if (cpipe->next->res_word == RES_DO)
8088 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8089 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8090 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8092 syntax_error("malformed for");
8094 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8101 /* Past this point, all code paths should jump to ret: label
8102 * in order to return, no direct "return" statements please.
8103 * This helps to ensure that no memory is leaked. */
8111 last_rword = RES_XXXX;
8113 last_followup = PIPE_SEQ;
8114 rcode = G.last_exitcode;
8116 /* Go through list of pipes, (maybe) executing them. */
8117 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8119 int sv_errexit_depth;
8123 if (G_flag_return_in_progress == 1)
8126 IF_HAS_KEYWORDS(rword = pi->res_word;)
8127 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8128 rword, cond_code, last_rword);
8130 sv_errexit_depth = G.errexit_depth;
8131 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8132 pi->followup != PIPE_SEQ
8136 #if ENABLE_HUSH_LOOPS
8137 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8138 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8140 /* start of a loop: remember where loop starts */
8145 /* Still in the same "if...", "then..." or "do..." branch? */
8146 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8147 if ((rcode == 0 && last_followup == PIPE_OR)
8148 || (rcode != 0 && last_followup == PIPE_AND)
8150 /* It is "<true> || CMD" or "<false> && CMD"
8151 * and we should not execute CMD */
8152 debug_printf_exec("skipped cmd because of || or &&\n");
8153 last_followup = pi->followup;
8154 goto dont_check_jobs_but_continue;
8157 last_followup = pi->followup;
8158 IF_HAS_KEYWORDS(last_rword = rword;)
8161 if (rword == RES_THEN) {
8162 /* if false; then ... fi has exitcode 0! */
8163 G.last_exitcode = rcode = EXIT_SUCCESS;
8164 /* "if <false> THEN cmd": skip cmd */
8168 if (rword == RES_ELSE || rword == RES_ELIF) {
8169 /* "if <true> then ... ELSE/ELIF cmd":
8170 * skip cmd and all following ones */
8175 #if ENABLE_HUSH_LOOPS
8176 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8178 /* first loop through for */
8180 static const char encoded_dollar_at[] ALIGN1 = {
8181 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8182 }; /* encoded representation of "$@" */
8183 static const char *const encoded_dollar_at_argv[] = {
8184 encoded_dollar_at, NULL
8185 }; /* argv list with one element: "$@" */
8188 vals = (char**)encoded_dollar_at_argv;
8189 if (pi->next->res_word == RES_IN) {
8190 /* if no variable values after "in" we skip "for" */
8191 if (!pi->next->cmds[0].argv) {
8192 G.last_exitcode = rcode = EXIT_SUCCESS;
8193 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8196 vals = pi->next->cmds[0].argv;
8197 } /* else: "for var; do..." -> assume "$@" list */
8198 /* create list of variable values */
8199 debug_print_strings("for_list made from", vals);
8200 for_list = expand_strvec_to_strvec(vals);
8201 for_lcur = for_list;
8202 debug_print_strings("for_list", for_list);
8205 /* "for" loop is over, clean up */
8211 /* Insert next value from for_lcur */
8212 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8213 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8216 if (rword == RES_IN) {
8217 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8219 if (rword == RES_DONE) {
8220 continue; /* "done" has no cmds too */
8223 #if ENABLE_HUSH_CASE
8224 if (rword == RES_CASE) {
8225 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8226 case_word = expand_strvec_to_string(pi->cmds->argv);
8227 unbackslash(case_word);
8230 if (rword == RES_MATCH) {
8233 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8234 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8236 /* all prev words didn't match, does this one match? */
8237 argv = pi->cmds->argv;
8239 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8240 /* TODO: which FNM_xxx flags to use? */
8241 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8242 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8244 if (cond_code == 0) { /* match! we will execute this branch */
8246 case_word = NULL; /* make future "word)" stop */
8253 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8254 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8256 continue; /* not matched yet, skip this pipe */
8258 if (rword == RES_ESAC) {
8259 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8261 /* "case" did not match anything: still set $? (to 0) */
8262 G.last_exitcode = rcode = EXIT_SUCCESS;
8266 /* Just pressing <enter> in shell should check for jobs.
8267 * OTOH, in non-interactive shell this is useless
8268 * and only leads to extra job checks */
8269 if (pi->num_cmds == 0) {
8270 if (G_interactive_fd)
8271 goto check_jobs_and_continue;
8275 /* After analyzing all keywords and conditions, we decided
8276 * to execute this pipe. NB: have to do checkjobs(NULL)
8277 * after run_pipe to collect any background children,
8278 * even if list execution is to be stopped. */
8279 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8280 #if ENABLE_HUSH_LOOPS
8281 G.flag_break_continue = 0;
8283 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8285 /* We ran a builtin, function, or group.
8286 * rcode is already known
8287 * and we don't need to wait for anything. */
8288 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8289 G.last_exitcode = rcode;
8290 check_and_run_traps();
8291 #if ENABLE_HUSH_LOOPS
8292 /* Was it "break" or "continue"? */
8293 if (G.flag_break_continue) {
8294 smallint fbc = G.flag_break_continue;
8295 /* We might fall into outer *loop*,
8296 * don't want to break it too */
8298 G.depth_break_continue--;
8299 if (G.depth_break_continue == 0)
8300 G.flag_break_continue = 0;
8301 /* else: e.g. "continue 2" should *break* once, *then* continue */
8302 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8303 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8304 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8307 /* "continue": simulate end of loop */
8312 if (G_flag_return_in_progress == 1) {
8313 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8316 } else if (pi->followup == PIPE_BG) {
8317 /* What does bash do with attempts to background builtins? */
8318 /* even bash 3.2 doesn't do that well with nested bg:
8319 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8320 * I'm NOT treating inner &'s as jobs */
8322 if (G.run_list_level == 1)
8323 insert_job_into_table(pi);
8325 /* Last command's pid goes to $! */
8326 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8327 G.last_bg_pid_exitcode = 0;
8328 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8329 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8330 rcode = EXIT_SUCCESS;
8334 if (G.run_list_level == 1 && G_interactive_fd) {
8335 /* Waits for completion, then fg's main shell */
8336 rcode = checkjobs_and_fg_shell(pi);
8337 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8341 /* This one just waits for completion */
8342 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8343 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8345 G.last_exitcode = rcode;
8346 check_and_run_traps();
8349 /* Handle "set -e" */
8350 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8351 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8352 if (G.errexit_depth == 0)
8355 G.errexit_depth = sv_errexit_depth;
8357 /* Analyze how result affects subsequent commands */
8359 if (rword == RES_IF || rword == RES_ELIF)
8362 check_jobs_and_continue:
8363 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8364 dont_check_jobs_but_continue: ;
8365 #if ENABLE_HUSH_LOOPS
8366 /* Beware of "while false; true; do ..."! */
8368 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8369 /* check for RES_DONE is needed for "while ...; do \n done" case */
8371 if (rword == RES_WHILE) {
8373 /* "while false; do...done" - exitcode 0 */
8374 G.last_exitcode = rcode = EXIT_SUCCESS;
8375 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8379 if (rword == RES_UNTIL) {
8381 debug_printf_exec(": until expr is true: breaking\n");
8392 #if ENABLE_HUSH_LOOPS
8397 #if ENABLE_HUSH_CASE
8401 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8405 /* Select which version we will use */
8406 static int run_and_free_list(struct pipe *pi)
8409 debug_printf_exec("run_and_free_list entered\n");
8410 if (!G.o_opt[OPT_O_NOEXEC]) {
8411 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8412 rcode = run_list(pi);
8414 /* free_pipe_list has the side effect of clearing memory.
8415 * In the long run that function can be merged with run_list,
8416 * but doing that now would hobble the debugging effort. */
8418 debug_printf_exec("run_and_free_list return %d\n", rcode);
8423 static void install_sighandlers(unsigned mask)
8425 sighandler_t old_handler;
8427 while ((mask >>= 1) != 0) {
8431 old_handler = install_sighandler(sig, pick_sighandler(sig));
8432 /* POSIX allows shell to re-enable SIGCHLD
8433 * even if it was SIG_IGN on entry.
8434 * Therefore we skip IGN check for it:
8438 if (old_handler == SIG_IGN) {
8439 /* oops... restore back to IGN, and record this fact */
8440 install_sighandler(sig, old_handler);
8441 #if ENABLE_HUSH_TRAP
8443 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8445 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8451 /* Called a few times only (or even once if "sh -c") */
8452 static void install_special_sighandlers(void)
8456 /* Which signals are shell-special? */
8457 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8458 if (G_interactive_fd) {
8459 mask |= SPECIAL_INTERACTIVE_SIGS;
8460 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8461 mask |= SPECIAL_JOBSTOP_SIGS;
8463 /* Careful, do not re-install handlers we already installed */
8464 if (G.special_sig_mask != mask) {
8465 unsigned diff = mask & ~G.special_sig_mask;
8466 G.special_sig_mask = mask;
8467 install_sighandlers(diff);
8473 /* Set handlers to restore tty pgrp and exit */
8474 static void install_fatal_sighandlers(void)
8478 /* We will restore tty pgrp on these signals */
8480 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8481 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8482 + (1 << SIGBUS ) * HUSH_DEBUG
8483 + (1 << SIGSEGV) * HUSH_DEBUG
8484 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8486 /* bash 3.2 seems to handle these just like 'fatal' ones */
8489 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8490 * if we aren't interactive... but in this case
8491 * we never want to restore pgrp on exit, and this fn is not called
8493 /*+ (1 << SIGHUP )*/
8494 /*+ (1 << SIGTERM)*/
8495 /*+ (1 << SIGINT )*/
8497 G_fatal_sig_mask = mask;
8499 install_sighandlers(mask);
8503 static int set_mode(int state, char mode, const char *o_opt)
8508 G.o_opt[OPT_O_NOEXEC] = state;
8511 IF_HUSH_MODE_X(G_x_mode = state;)
8515 /* "set -+o" without parameter.
8516 * in bash, set -o produces this output:
8520 * We always use the second form.
8522 const char *p = o_opt_strings;
8525 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8531 idx = index_in_strings(o_opt_strings, o_opt);
8533 G.o_opt[idx] = state;
8537 G.o_opt[OPT_O_ERREXIT] = state;
8540 return EXIT_FAILURE;
8542 return EXIT_SUCCESS;
8545 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8546 int hush_main(int argc, char **argv)
8549 OPT_login = (1 << 0),
8553 unsigned builtin_argc;
8555 struct variable *cur_var;
8556 struct variable *shell_ver;
8559 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8560 G.last_exitcode = EXIT_SUCCESS;
8562 #if ENABLE_HUSH_FAST
8563 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8566 G.argv0_for_re_execing = argv[0];
8568 /* Deal with HUSH_VERSION */
8569 shell_ver = xzalloc(sizeof(*shell_ver));
8570 shell_ver->flg_export = 1;
8571 shell_ver->flg_read_only = 1;
8572 /* Code which handles ${var<op>...} needs writable values for all variables,
8573 * therefore we xstrdup: */
8574 shell_ver->varstr = xstrdup(hush_version_str);
8575 /* Create shell local variables from the values
8576 * currently living in the environment */
8577 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8578 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8579 G.top_var = shell_ver;
8580 cur_var = G.top_var;
8583 char *value = strchr(*e, '=');
8584 if (value) { /* paranoia */
8585 cur_var->next = xzalloc(sizeof(*cur_var));
8586 cur_var = cur_var->next;
8587 cur_var->varstr = *e;
8588 cur_var->max_len = strlen(*e);
8589 cur_var->flg_export = 1;
8593 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8594 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8595 putenv(shell_ver->varstr);
8598 set_pwd_var(/*exp:*/ 1);
8600 #if BASH_HOSTNAME_VAR
8601 /* Set (but not export) HOSTNAME unless already set */
8602 if (!get_local_var_value("HOSTNAME")) {
8605 set_local_var_from_halves("HOSTNAME", uts.nodename);
8607 /* bash also exports SHLVL and _,
8608 * and sets (but doesn't export) the following variables:
8610 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8611 * BASH_VERSION='3.2.0(1)-release'
8613 * MACHTYPE=i386-pc-linux-gnu
8615 * PPID=<NNNNN> - we also do it elsewhere
8626 * PIPESTATUS=([0]="0")
8627 * HISTFILE=/<xxx>/.bash_history
8631 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8633 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8644 #if ENABLE_FEATURE_EDITING
8645 G.line_input_state = new_line_input_t(FOR_SHELL);
8648 /* Initialize some more globals to non-zero values */
8649 cmdedit_update_prompt();
8651 die_func = restore_ttypgrp_and__exit;
8653 /* Shell is non-interactive at first. We need to call
8654 * install_special_sighandlers() if we are going to execute "sh <script>",
8655 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8656 * If we later decide that we are interactive, we run install_special_sighandlers()
8657 * in order to intercept (more) signals.
8661 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8662 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8665 opt = getopt(argc, argv, "+c:exinsl"
8668 # if ENABLE_HUSH_FUNCTIONS
8678 * sh ... -c 'script'
8679 * sh ... -c 'script' ARG0 [ARG1...]
8680 * On NOMMU, if builtin_argc != 0,
8681 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8682 * "" needs to be replaced with NULL
8683 * and BARGV vector fed to builtin function.
8684 * Note: the form without ARG0 never happens:
8685 * sh ... -c 'builtin' BARGV... ""
8688 G.root_pid = getpid();
8689 G.root_ppid = getppid();
8691 G.global_argv = argv + optind;
8692 G.global_argc = argc - optind;
8694 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8695 const struct built_in_command *x;
8697 install_special_sighandlers();
8698 x = find_builtin(optarg);
8699 if (x) { /* paranoia */
8700 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8701 G.global_argv += builtin_argc;
8702 G.global_argv[-1] = NULL; /* replace "" */
8704 G.last_exitcode = x->b_function(argv + optind - 1);
8708 if (!G.global_argv[0]) {
8709 /* -c 'script' (no params): prevent empty $0 */
8710 G.global_argv--; /* points to argv[i] of 'script' */
8711 G.global_argv[0] = argv[0];
8713 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8714 install_special_sighandlers();
8715 parse_and_run_string(optarg);
8718 /* Well, we cannot just declare interactiveness,
8719 * we have to have some stuff (ctty, etc) */
8720 /* G_interactive_fd++; */
8723 /* "-s" means "read from stdin", but this is how we always
8724 * operate, so simply do nothing here. */
8730 case '<': /* "big heredoc" support */
8731 full_write1_str(optarg);
8734 unsigned long long empty_trap_mask;
8736 G.root_pid = bb_strtou(optarg, &optarg, 16);
8738 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8740 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8742 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8744 builtin_argc = bb_strtou(optarg, &optarg, 16);
8746 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8747 if (empty_trap_mask != 0) {
8748 IF_HUSH_TRAP(int sig;)
8749 install_special_sighandlers();
8750 # if ENABLE_HUSH_TRAP
8751 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8752 for (sig = 1; sig < NSIG; sig++) {
8753 if (empty_trap_mask & (1LL << sig)) {
8754 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8755 install_sighandler(sig, SIG_IGN);
8760 # if ENABLE_HUSH_LOOPS
8762 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8768 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8770 # if ENABLE_HUSH_FUNCTIONS
8772 struct function *funcp = new_function(optarg);
8773 /* funcp->name is already set to optarg */
8774 /* funcp->body is set to NULL. It's a special case. */
8775 funcp->body_as_string = argv[optind];
8784 if (set_mode(1, opt, NULL) == 0) /* no error */
8788 fprintf(stderr, "Usage: sh [FILE]...\n"
8789 " or: sh -c command [args]...\n\n");
8795 } /* option parsing loop */
8797 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8798 G.global_argc = argc - (optind - 1);
8799 G.global_argv = argv + (optind - 1);
8800 G.global_argv[0] = argv[0];
8803 G.root_pid = getpid();
8804 G.root_ppid = getppid();
8807 /* If we are login shell... */
8808 if (flags & OPT_login) {
8810 debug_printf("sourcing /etc/profile\n");
8811 input = fopen_for_read("/etc/profile");
8812 if (input != NULL) {
8813 remember_FILE(input);
8814 install_special_sighandlers();
8815 parse_and_run_file(input);
8816 fclose_and_forget(input);
8818 /* bash: after sourcing /etc/profile,
8819 * tries to source (in the given order):
8820 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8821 * stopping on first found. --noprofile turns this off.
8822 * bash also sources ~/.bash_logout on exit.
8823 * If called as sh, skips .bash_XXX files.
8827 if (G.global_argv[1]) {
8830 * "bash <script>" (which is never interactive (unless -i?))
8831 * sources $BASH_ENV here (without scanning $PATH).
8832 * If called as sh, does the same but with $ENV.
8833 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8837 debug_printf("running script '%s'\n", G.global_argv[0]);
8838 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8839 input = xfopen_for_read(G.global_argv[0]);
8840 xfunc_error_retval = 1;
8841 remember_FILE(input);
8842 install_special_sighandlers();
8843 parse_and_run_file(input);
8844 #if ENABLE_FEATURE_CLEAN_UP
8845 fclose_and_forget(input);
8850 /* Up to here, shell was non-interactive. Now it may become one.
8851 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8854 /* A shell is interactive if the '-i' flag was given,
8855 * or if all of the following conditions are met:
8857 * no arguments remaining or the -s flag given
8858 * standard input is a terminal
8859 * standard output is a terminal
8860 * Refer to Posix.2, the description of the 'sh' utility.
8863 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8864 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8865 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8866 if (G_saved_tty_pgrp < 0)
8867 G_saved_tty_pgrp = 0;
8869 /* try to dup stdin to high fd#, >= 255 */
8870 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8871 if (G_interactive_fd < 0) {
8872 /* try to dup to any fd */
8873 G_interactive_fd = dup(STDIN_FILENO);
8874 if (G_interactive_fd < 0) {
8876 G_interactive_fd = 0;
8877 G_saved_tty_pgrp = 0;
8880 // TODO: track & disallow any attempts of user
8881 // to (inadvertently) close/redirect G_interactive_fd
8883 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8884 if (G_interactive_fd) {
8885 close_on_exec_on(G_interactive_fd);
8887 if (G_saved_tty_pgrp) {
8888 /* If we were run as 'hush &', sleep until we are
8889 * in the foreground (tty pgrp == our pgrp).
8890 * If we get started under a job aware app (like bash),
8891 * make sure we are now in charge so we don't fight over
8892 * who gets the foreground */
8894 pid_t shell_pgrp = getpgrp();
8895 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8896 if (G_saved_tty_pgrp == shell_pgrp)
8898 /* send TTIN to ourself (should stop us) */
8899 kill(- shell_pgrp, SIGTTIN);
8903 /* Install more signal handlers */
8904 install_special_sighandlers();
8906 if (G_saved_tty_pgrp) {
8907 /* Set other signals to restore saved_tty_pgrp */
8908 install_fatal_sighandlers();
8909 /* Put ourselves in our own process group
8910 * (bash, too, does this only if ctty is available) */
8911 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8912 /* Grab control of the terminal */
8913 tcsetpgrp(G_interactive_fd, getpid());
8915 enable_restore_tty_pgrp_on_exit();
8917 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8919 const char *hp = get_local_var_value("HISTFILE");
8921 hp = get_local_var_value("HOME");
8923 hp = concat_path_file(hp, ".hush_history");
8928 G.line_input_state->hist_file = hp;
8929 //set_local_var(xasprintf("HISTFILE=%s", ...));
8931 # if ENABLE_FEATURE_SH_HISTFILESIZE
8932 hp = get_local_var_value("HISTFILESIZE");
8933 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8938 install_special_sighandlers();
8940 #elif ENABLE_HUSH_INTERACTIVE
8941 /* No job control compiled in, only prompt/line editing */
8942 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8943 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8944 if (G_interactive_fd < 0) {
8945 /* try to dup to any fd */
8946 G_interactive_fd = dup(STDIN_FILENO);
8947 if (G_interactive_fd < 0)
8949 G_interactive_fd = 0;
8952 if (G_interactive_fd) {
8953 close_on_exec_on(G_interactive_fd);
8955 install_special_sighandlers();
8957 /* We have interactiveness code disabled */
8958 install_special_sighandlers();
8961 * if interactive but not a login shell, sources ~/.bashrc
8962 * (--norc turns this off, --rcfile <file> overrides)
8965 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8966 /* note: ash and hush share this string */
8967 printf("\n\n%s %s\n"
8968 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8971 "hush - the humble shell"
8975 parse_and_run_file(stdin);
8978 hush_exit(G.last_exitcode);
8985 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8990 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8991 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8993 int argc = string_array_len(argv);
8994 return applet_main_func(argc, argv);
8997 #if ENABLE_HUSH_TEST || BASH_TEST2
8998 static int FAST_FUNC builtin_test(char **argv)
9000 return run_applet_main(argv, test_main);
9003 #if ENABLE_HUSH_ECHO
9004 static int FAST_FUNC builtin_echo(char **argv)
9006 return run_applet_main(argv, echo_main);
9009 #if ENABLE_HUSH_PRINTF
9010 static int FAST_FUNC builtin_printf(char **argv)
9012 return run_applet_main(argv, printf_main);
9016 #if ENABLE_HUSH_HELP
9017 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9019 const struct built_in_command *x;
9022 "Built-in commands:\n"
9023 "------------------\n");
9024 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9026 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9028 return EXIT_SUCCESS;
9032 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9033 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9035 show_history(G.line_input_state);
9036 return EXIT_SUCCESS;
9040 static char **skip_dash_dash(char **argv)
9043 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9048 static int FAST_FUNC builtin_cd(char **argv)
9052 argv = skip_dash_dash(argv);
9054 if (newdir == NULL) {
9055 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9056 * bash says "bash: cd: HOME not set" and does nothing
9059 const char *home = get_local_var_value("HOME");
9060 newdir = home ? home : "/";
9062 if (chdir(newdir)) {
9063 /* Mimic bash message exactly */
9064 bb_perror_msg("cd: %s", newdir);
9065 return EXIT_FAILURE;
9067 /* Read current dir (get_cwd(1) is inside) and set PWD.
9068 * Note: do not enforce exporting. If PWD was unset or unexported,
9069 * set it again, but do not export. bash does the same.
9071 set_pwd_var(/*exp:*/ 0);
9072 return EXIT_SUCCESS;
9075 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9078 return EXIT_SUCCESS;
9081 static int FAST_FUNC builtin_eval(char **argv)
9083 int rcode = EXIT_SUCCESS;
9085 argv = skip_dash_dash(argv);
9087 char *str = expand_strvec_to_string(argv);
9089 * eval "echo Hi; done" ("done" is syntax error):
9090 * "echo Hi" will not execute too.
9092 parse_and_run_string(str);
9094 rcode = G.last_exitcode;
9099 static int FAST_FUNC builtin_exec(char **argv)
9101 argv = skip_dash_dash(argv);
9102 if (argv[0] == NULL)
9103 return EXIT_SUCCESS; /* bash does this */
9105 /* Careful: we can end up here after [v]fork. Do not restore
9106 * tty pgrp then, only top-level shell process does that */
9107 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9108 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9110 /* TODO: if exec fails, bash does NOT exit! We do.
9111 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9112 * and tcsetpgrp, and this is inherently racy.
9114 execvp_or_die(argv);
9117 static int FAST_FUNC builtin_exit(char **argv)
9119 debug_printf_exec("%s()\n", __func__);
9121 /* interactive bash:
9122 * # trap "echo EEE" EXIT
9125 * There are stopped jobs.
9126 * (if there are _stopped_ jobs, running ones don't count)
9129 * EEE (then bash exits)
9131 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9134 /* note: EXIT trap is run by hush_exit */
9135 argv = skip_dash_dash(argv);
9136 if (argv[0] == NULL)
9137 hush_exit(G.last_exitcode);
9138 /* mimic bash: exit 123abc == exit 255 + error msg */
9139 xfunc_error_retval = 255;
9140 /* bash: exit -2 == exit 254, no error msg */
9141 hush_exit(xatoi(argv[0]) & 0xff);
9144 #if ENABLE_HUSH_TYPE
9145 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9146 static int FAST_FUNC builtin_type(char **argv)
9148 int ret = EXIT_SUCCESS;
9154 if (0) {} /* make conditional compile easier below */
9155 /*else if (find_alias(*argv))
9156 type = "an alias";*/
9157 #if ENABLE_HUSH_FUNCTIONS
9158 else if (find_function(*argv))
9159 type = "a function";
9161 else if (find_builtin(*argv))
9162 type = "a shell builtin";
9163 else if ((path = find_in_path(*argv)) != NULL)
9166 bb_error_msg("type: %s: not found", *argv);
9171 printf("%s is %s\n", *argv, type);
9179 #if ENABLE_HUSH_READ
9180 /* Interruptibility of read builtin in bash
9181 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9183 * Empty trap makes read ignore corresponding signal, for any signal.
9186 * - terminates non-interactive shell;
9187 * - interrupts read in interactive shell;
9188 * if it has non-empty trap:
9189 * - executes trap and returns to command prompt in interactive shell;
9190 * - executes trap and returns to read in non-interactive shell;
9192 * - is ignored (does not interrupt) read in interactive shell;
9193 * - terminates non-interactive shell;
9194 * if it has non-empty trap:
9195 * - executes trap and returns to read;
9197 * - terminates shell (regardless of interactivity);
9198 * if it has non-empty trap:
9199 * - executes trap and returns to read;
9200 * SIGCHLD from children:
9201 * - does not interrupt read regardless of interactivity:
9202 * try: sleep 1 & read x; echo $x
9204 static int FAST_FUNC builtin_read(char **argv)
9214 /* "!": do not abort on errors.
9215 * Option string must start with "sr" to match BUILTIN_READ_xxx
9217 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9218 if (read_flags == (uint32_t)-1)
9219 return EXIT_FAILURE;
9221 ifs = get_local_var_value("IFS"); /* can be NULL */
9224 r = shell_builtin_read(set_local_var_from_halves,
9234 if ((uintptr_t)r == 1 && errno == EINTR) {
9235 unsigned sig = check_and_run_traps();
9240 if ((uintptr_t)r > 1) {
9241 bb_error_msg("%s", r);
9242 r = (char*)(uintptr_t)1;
9245 return (uintptr_t)r;
9249 #if ENABLE_HUSH_UMASK
9250 static int FAST_FUNC builtin_umask(char **argv)
9257 argv = skip_dash_dash(argv);
9259 mode_t old_mask = mask;
9261 /* numeric umasks are taken as-is */
9262 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9263 if (!isdigit(argv[0][0]))
9265 mask = bb_parse_mode(argv[0], mask);
9266 if (!isdigit(argv[0][0]))
9268 if ((unsigned)mask > 0777) {
9271 * bash: umask: 'q': invalid symbolic mode operator
9272 * bash: umask: 999: octal number out of range
9274 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9279 printf("%04o\n", (unsigned) mask);
9280 /* fall through and restore mask which we set to 0 */
9284 return !rc; /* rc != 0 - success */
9288 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9289 static void print_escaped(const char *s)
9294 const char *p = strchrnul(s, '\'');
9295 /* print 'xxxx', possibly just '' */
9296 printf("'%.*s'", (int)(p - s), s);
9301 /* s points to '; print "'''...'''" */
9303 do putchar('\''); while (*++s == '\'');
9309 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9310 # if !ENABLE_HUSH_LOCAL
9311 #define helper_export_local(argv, exp, lvl) \
9312 helper_export_local(argv, exp)
9314 static void helper_export_local(char **argv, int exp, int lvl)
9318 char *name_end = strchrnul(name, '=');
9320 /* So far we do not check that name is valid (TODO?) */
9322 if (*name_end == '\0') {
9323 struct variable *var, **vpp;
9325 vpp = get_ptr_to_local_var(name, name_end - name);
9326 var = vpp ? *vpp : NULL;
9328 if (exp == -1) { /* unexporting? */
9329 /* export -n NAME (without =VALUE) */
9331 var->flg_export = 0;
9332 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9334 } /* else: export -n NOT_EXISTING_VAR: no-op */
9337 if (exp == 1) { /* exporting? */
9338 /* export NAME (without =VALUE) */
9340 var->flg_export = 1;
9341 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9342 putenv(var->varstr);
9346 # if ENABLE_HUSH_LOCAL
9347 if (exp == 0 /* local? */
9348 && var && var->func_nest_level == lvl
9350 /* "local x=abc; ...; local x" - ignore second local decl */
9354 /* Exporting non-existing variable.
9355 * bash does not put it in environment,
9356 * but remembers that it is exported,
9357 * and does put it in env when it is set later.
9358 * We just set it to "" and export. */
9359 /* Or, it's "local NAME" (without =VALUE).
9360 * bash sets the value to "". */
9361 name = xasprintf("%s=", name);
9363 /* (Un)exporting/making local NAME=VALUE */
9364 name = xstrdup(name);
9366 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9371 #if ENABLE_HUSH_EXPORT
9372 static int FAST_FUNC builtin_export(char **argv)
9374 unsigned opt_unexport;
9376 #if ENABLE_HUSH_EXPORT_N
9377 /* "!": do not abort on errors */
9378 opt_unexport = getopt32(argv, "!n");
9379 if (opt_unexport == (uint32_t)-1)
9380 return EXIT_FAILURE;
9387 if (argv[0] == NULL) {
9394 /* ash emits: export VAR='VAL'
9395 * bash: declare -x VAR="VAL"
9396 * we follow ash example */
9397 const char *s = *e++;
9398 const char *p = strchr(s, '=');
9400 if (!p) /* wtf? take next variable */
9403 printf("export %.*s", (int)(p - s) + 1, s);
9404 print_escaped(p + 1);
9408 /*fflush_all(); - done after each builtin anyway */
9410 return EXIT_SUCCESS;
9413 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9415 return EXIT_SUCCESS;
9419 #if ENABLE_HUSH_LOCAL
9420 static int FAST_FUNC builtin_local(char **argv)
9422 if (G.func_nest_level == 0) {
9423 bb_error_msg("%s: not in a function", argv[0]);
9424 return EXIT_FAILURE; /* bash compat */
9426 helper_export_local(argv, 0, G.func_nest_level);
9427 return EXIT_SUCCESS;
9431 #if ENABLE_HUSH_UNSET
9432 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9433 static int FAST_FUNC builtin_unset(char **argv)
9438 /* "!": do not abort on errors */
9439 /* "+": stop at 1st non-option */
9440 opts = getopt32(argv, "!+vf");
9441 if (opts == (unsigned)-1)
9442 return EXIT_FAILURE;
9444 bb_error_msg("unset: -v and -f are exclusive");
9445 return EXIT_FAILURE;
9451 if (!(opts & 2)) { /* not -f */
9452 if (unset_local_var(*argv)) {
9453 /* unset <nonexistent_var> doesn't fail.
9454 * Error is when one tries to unset RO var.
9455 * Message was printed by unset_local_var. */
9459 # if ENABLE_HUSH_FUNCTIONS
9471 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9472 * built-in 'set' handler
9474 * set [-abCefhmnuvx] [-o option] [argument...]
9475 * set [+abCefhmnuvx] [+o option] [argument...]
9476 * set -- [argument...]
9479 * Implementations shall support the options in both their hyphen and
9480 * plus-sign forms. These options can also be specified as options to sh.
9482 * Write out all variables and their values: set
9483 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9484 * Turn on the -x and -v options: set -xv
9485 * Unset all positional parameters: set --
9486 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9487 * Set the positional parameters to the expansion of x, even if x expands
9488 * with a leading '-' or '+': set -- $x
9490 * So far, we only support "set -- [argument...]" and some of the short names.
9492 static int FAST_FUNC builtin_set(char **argv)
9495 char **pp, **g_argv;
9496 char *arg = *++argv;
9500 for (e = G.top_var; e; e = e->next)
9502 return EXIT_SUCCESS;
9506 if (strcmp(arg, "--") == 0) {
9510 if (arg[0] != '+' && arg[0] != '-')
9512 for (n = 1; arg[n]; ++n) {
9513 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9515 if (arg[n] == 'o' && argv[1])
9518 } while ((arg = *++argv) != NULL);
9519 /* Now argv[0] is 1st argument */
9522 return EXIT_SUCCESS;
9525 /* NB: G.global_argv[0] ($0) is never freed/changed */
9526 g_argv = G.global_argv;
9527 if (G.global_args_malloced) {
9533 G.global_args_malloced = 1;
9534 pp = xzalloc(sizeof(pp[0]) * 2);
9535 pp[0] = g_argv[0]; /* retain $0 */
9538 /* This realloc's G.global_argv */
9539 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9541 G.global_argc = 1 + string_array_len(pp + 1);
9543 return EXIT_SUCCESS;
9545 /* Nothing known, so abort */
9547 bb_error_msg("set: %s: invalid option", arg);
9548 return EXIT_FAILURE;
9552 static int FAST_FUNC builtin_shift(char **argv)
9555 argv = skip_dash_dash(argv);
9557 n = bb_strtou(argv[0], NULL, 10);
9558 if (errno || n < 0) {
9559 /* shared string with ash.c */
9560 bb_error_msg("Illegal number: %s", argv[0]);
9562 * ash aborts in this case.
9563 * bash prints error message and set $? to 1.
9564 * Interestingly, for "shift 99999" bash does not
9565 * print error message, but does set $? to 1
9566 * (and does no shifting at all).
9570 if (n >= 0 && n < G.global_argc) {
9571 if (G_global_args_malloced) {
9574 free(G.global_argv[m++]);
9577 memmove(&G.global_argv[1], &G.global_argv[n+1],
9578 G.global_argc * sizeof(G.global_argv[0]));
9579 return EXIT_SUCCESS;
9581 return EXIT_FAILURE;
9584 static int FAST_FUNC builtin_source(char **argv)
9586 char *arg_path, *filename;
9589 char *args_need_save;
9590 #if ENABLE_HUSH_FUNCTIONS
9594 argv = skip_dash_dash(argv);
9597 /* bash says: "bash: .: filename argument required" */
9598 return 2; /* bash compat */
9601 if (!strchr(filename, '/')) {
9602 arg_path = find_in_path(filename);
9604 filename = arg_path;
9606 input = remember_FILE(fopen_or_warn(filename, "r"));
9609 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9610 /* POSIX: non-interactive shell should abort here,
9611 * not merely fail. So far no one complained :)
9613 return EXIT_FAILURE;
9616 #if ENABLE_HUSH_FUNCTIONS
9617 sv_flg = G_flag_return_in_progress;
9618 /* "we are inside sourced file, ok to use return" */
9619 G_flag_return_in_progress = -1;
9621 args_need_save = argv[1]; /* used as a boolean variable */
9623 save_and_replace_G_args(&sv, argv);
9625 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9626 G.last_exitcode = 0;
9627 parse_and_run_file(input);
9628 fclose_and_forget(input);
9630 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9631 restore_G_args(&sv, argv);
9632 #if ENABLE_HUSH_FUNCTIONS
9633 G_flag_return_in_progress = sv_flg;
9636 return G.last_exitcode;
9639 #if ENABLE_HUSH_TRAP
9640 static int FAST_FUNC builtin_trap(char **argv)
9646 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9651 /* No args: print all trapped */
9652 for (i = 0; i < NSIG; ++i) {
9655 print_escaped(G_traps[i]);
9656 /* note: bash adds "SIG", but only if invoked
9657 * as "bash". If called as "sh", or if set -o posix,
9658 * then it prints short signal names.
9659 * We are printing short names: */
9660 printf(" %s\n", get_signame(i));
9663 /*fflush_all(); - done after each builtin anyway */
9664 return EXIT_SUCCESS;
9668 /* If first arg is a number: reset all specified signals */
9669 sig = bb_strtou(*argv, NULL, 10);
9675 sighandler_t handler;
9677 sig = get_signum(*argv++);
9678 if (sig < 0 || sig >= NSIG) {
9680 /* Mimic bash message exactly */
9681 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9686 G_traps[sig] = xstrdup(new_cmd);
9688 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9689 get_signame(sig), sig, G_traps[sig]);
9691 /* There is no signal for 0 (EXIT) */
9696 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9698 /* We are removing trap handler */
9699 handler = pick_sighandler(sig);
9700 install_sighandler(sig, handler);
9705 if (!argv[1]) { /* no second arg */
9706 bb_error_msg("trap: invalid arguments");
9707 return EXIT_FAILURE;
9710 /* First arg is "-": reset all specified to default */
9711 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9712 /* Everything else: set arg as signal handler
9713 * (includes "" case, which ignores signal) */
9714 if (argv[0][0] == '-') {
9715 if (argv[0][1] == '\0') { /* "-" */
9716 /* new_cmd remains NULL: "reset these sigs" */
9719 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9722 /* else: "-something", no special meaning */
9727 goto process_sig_list;
9732 static struct pipe *parse_jobspec(const char *str)
9737 if (sscanf(str, "%%%u", &jobnum) != 1) {
9739 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9741 bb_error_msg("bad argument '%s'", str);
9744 /* It is "%%", "%+" or "%" - current job */
9745 jobnum = G.last_jobid;
9747 bb_error_msg("no current job");
9751 for (pi = G.job_list; pi; pi = pi->next) {
9752 if (pi->jobid == jobnum) {
9756 bb_error_msg("%u: no such job", jobnum);
9760 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9763 const char *status_string;
9765 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9766 for (job = G.job_list; job; job = job->next) {
9767 if (job->alive_cmds == job->stopped_cmds)
9768 status_string = "Stopped";
9770 status_string = "Running";
9772 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9775 clean_up_last_dead_job();
9777 return EXIT_SUCCESS;
9780 /* built-in 'fg' and 'bg' handler */
9781 static int FAST_FUNC builtin_fg_bg(char **argv)
9786 if (!G_interactive_fd)
9787 return EXIT_FAILURE;
9789 /* If they gave us no args, assume they want the last backgrounded task */
9791 for (pi = G.job_list; pi; pi = pi->next) {
9792 if (pi->jobid == G.last_jobid) {
9796 bb_error_msg("%s: no current job", argv[0]);
9797 return EXIT_FAILURE;
9800 pi = parse_jobspec(argv[1]);
9802 return EXIT_FAILURE;
9804 /* TODO: bash prints a string representation
9805 * of job being foregrounded (like "sleep 1 | cat") */
9806 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9807 /* Put the job into the foreground. */
9808 tcsetpgrp(G_interactive_fd, pi->pgrp);
9811 /* Restart the processes in the job */
9812 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9813 for (i = 0; i < pi->num_cmds; i++) {
9814 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9816 pi->stopped_cmds = 0;
9818 i = kill(- pi->pgrp, SIGCONT);
9820 if (errno == ESRCH) {
9821 delete_finished_job(pi);
9822 return EXIT_SUCCESS;
9824 bb_perror_msg("kill (SIGCONT)");
9827 if (argv[0][0] == 'f') {
9828 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9829 return checkjobs_and_fg_shell(pi);
9831 return EXIT_SUCCESS;
9835 #if ENABLE_HUSH_KILL
9836 static int FAST_FUNC builtin_kill(char **argv)
9840 # if ENABLE_HUSH_JOB
9841 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9849 if (argv[i][0] != '%')
9852 * "kill %N" - job kill
9853 * Converting to pgrp / pid kill
9855 pi = parse_jobspec(argv[i]);
9857 /* Eat bad jobspec */
9861 argv[j - 1] = argv[j];
9868 * In jobs started under job control, we signal
9869 * entire process group by kill -PGRP_ID.
9870 * This happens, f.e., in interactive shell.
9872 * Otherwise, we signal each child via
9873 * kill PID1 PID2 PID3.
9875 * sh -c 'sleep 1|sleep 1 & kill %1'
9876 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9877 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9879 n = G_interactive_fd ? 1 : pi->num_cmds;
9880 dst = alloca(n * sizeof(int)*4);
9882 if (G_interactive_fd)
9883 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9884 else for (j = 0; j < n; j++) {
9885 struct command *cmd = &pi->cmds[j];
9886 /* Skip exited members of the job */
9890 * kill_main has matching code to expect
9891 * leading space. Needed to not confuse
9892 * negative pids with "kill -SIGNAL_NO" syntax
9894 dst += sprintf(dst, " %u", (int)cmd->pid);
9897 } while (argv[++i]);
9901 if (argv[1] || ret == 0) {
9902 ret = run_applet_main(argv, kill_main);
9904 /* else: ret = 1, "kill %bad_jobspec" case */
9909 #if ENABLE_HUSH_WAIT
9910 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9911 #if !ENABLE_HUSH_JOB
9912 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9914 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9921 if (!sigisemptyset(&G.pending_set))
9924 /* waitpid is not interruptible by SA_RESTARTed
9925 * signals which we use. Thus, this ugly dance:
9928 /* Make sure possible SIGCHLD is stored in kernel's
9929 * pending signal mask before we call waitpid.
9930 * Or else we may race with SIGCHLD, lose it,
9931 * and get stuck in sigsuspend...
9933 sigfillset(&oldset); /* block all signals, remember old set */
9934 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9936 if (!sigisemptyset(&G.pending_set)) {
9937 /* Crap! we raced with some signal! */
9941 /*errno = 0; - checkjobs does this */
9942 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9943 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9944 debug_printf_exec("checkjobs:%d\n", ret);
9947 int rcode = job_exited_or_stopped(waitfor_pipe);
9948 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9951 sigprocmask(SIG_SETMASK, &oldset, NULL);
9956 /* if ECHILD, there are no children (ret is -1 or 0) */
9957 /* if ret == 0, no children changed state */
9958 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9959 if (errno == ECHILD || ret) {
9961 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9963 sigprocmask(SIG_SETMASK, &oldset, NULL);
9966 /* Wait for SIGCHLD or any other signal */
9967 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9968 /* Note: sigsuspend invokes signal handler */
9969 sigsuspend(&oldset);
9971 sigprocmask(SIG_SETMASK, &oldset, NULL);
9973 /* So, did we get a signal? */
9974 sig = check_and_run_traps();
9975 if (sig /*&& sig != SIGCHLD - always true */) {
9979 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9984 static int FAST_FUNC builtin_wait(char **argv)
9989 argv = skip_dash_dash(argv);
9990 if (argv[0] == NULL) {
9991 /* Don't care about wait results */
9992 /* Note 1: must wait until there are no more children */
9993 /* Note 2: must be interruptible */
9995 * $ sleep 3 & sleep 6 & wait
10000 * $ sleep 3 & sleep 6 & wait
10001 * [1] 30936 sleep 3
10002 * [2] 30937 sleep 6
10004 * ^C <-- after ~4 sec from keyboard
10007 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10011 pid_t pid = bb_strtou(*argv, NULL, 10);
10012 if (errno || pid <= 0) {
10013 #if ENABLE_HUSH_JOB
10014 if (argv[0][0] == '%') {
10015 struct pipe *wait_pipe;
10016 ret = 127; /* bash compat for bad jobspecs */
10017 wait_pipe = parse_jobspec(*argv);
10019 ret = job_exited_or_stopped(wait_pipe);
10021 ret = wait_for_child_or_signal(wait_pipe, 0);
10023 /* waiting on "last dead job" removes it */
10024 clean_up_last_dead_job();
10027 /* else: parse_jobspec() already emitted error msg */
10031 /* mimic bash message */
10032 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10033 ret = EXIT_FAILURE;
10034 continue; /* bash checks all argv[] */
10037 /* Do we have such child? */
10038 ret = waitpid(pid, &status, WNOHANG);
10042 if (errno == ECHILD) {
10043 if (pid == G.last_bg_pid) {
10044 /* "wait $!" but last bg task has already exited. Try:
10045 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10046 * In bash it prints exitcode 0, then 3.
10047 * In dash, it is 127.
10049 ret = G.last_bg_pid_exitcode;
10051 /* Example: "wait 1". mimic bash message */
10052 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10056 bb_perror_msg("wait %s", *argv);
10058 continue; /* bash checks all argv[] */
10061 /* Yes, and it still runs */
10062 ret = wait_for_child_or_signal(NULL, pid);
10064 /* Yes, and it just exited */
10065 process_wait_result(NULL, pid, status);
10066 ret = WEXITSTATUS(status);
10067 if (WIFSIGNALED(status))
10068 ret = 128 + WTERMSIG(status);
10076 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10077 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10080 def = bb_strtou(argv[1], NULL, 10);
10081 if (errno || def < def_min || argv[2]) {
10082 bb_error_msg("%s: bad arguments", argv[0]);
10090 #if ENABLE_HUSH_LOOPS
10091 static int FAST_FUNC builtin_break(char **argv)
10094 if (G.depth_of_loop == 0) {
10095 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10096 /* if we came from builtin_continue(), need to undo "= 1" */
10097 G.flag_break_continue = 0;
10098 return EXIT_SUCCESS; /* bash compat */
10100 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10102 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10103 if (depth == UINT_MAX)
10104 G.flag_break_continue = BC_BREAK;
10105 if (G.depth_of_loop < depth)
10106 G.depth_break_continue = G.depth_of_loop;
10108 return EXIT_SUCCESS;
10111 static int FAST_FUNC builtin_continue(char **argv)
10113 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10114 return builtin_break(argv);
10118 #if ENABLE_HUSH_FUNCTIONS
10119 static int FAST_FUNC builtin_return(char **argv)
10123 if (G_flag_return_in_progress != -1) {
10124 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10125 return EXIT_FAILURE; /* bash compat */
10128 G_flag_return_in_progress = 1;
10131 * out of range: wraps around at 256, does not error out
10132 * non-numeric param:
10133 * f() { false; return qwe; }; f; echo $?
10134 * bash: return: qwe: numeric argument required <== we do this
10135 * 255 <== we also do this
10137 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10142 #if ENABLE_HUSH_MEMLEAK
10143 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10148 # ifdef M_TRIM_THRESHOLD
10149 /* Optional. Reduces probability of false positives */
10152 /* Crude attempt to find where "free memory" starts,
10153 * sans fragmentation. */
10155 l = (unsigned long)p;
10158 if (l < (unsigned long)p) l = (unsigned long)p;
10164 struct mallinfo mi = mallinfo();
10165 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10166 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10170 if (!G.memleak_value)
10171 G.memleak_value = l;
10173 l -= G.memleak_value;
10180 /* Exitcode is "how many kilobytes we leaked since 1st call" */