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);
5727 /* negative beg counts from the end */
5728 beg = (arith_t)strlen(val) + beg;
5729 if (beg < 0) /* ${v: -999999} is "" */
5732 debug_printf_varexp("from val:'%s'\n", val);
5734 /* in bash, len=-n means strlen()-n */
5735 len = (arith_t)strlen(val) - beg + len;
5736 if (len < 0) /* bash compat */
5737 die_if_script("%s: substring expression < 0", var);
5739 if (len <= 0 || !val || beg >= strlen(val)) {
5743 /* Paranoia. What if user entered 9999999999999
5744 * which fits in arith_t but not int? */
5747 val = to_be_freed = xstrndup(val + beg, len);
5749 debug_printf_varexp("val:'%s'\n", val);
5750 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5751 die_if_script("malformed ${%s:...}", var);
5754 } else { /* one of "-=+?" */
5755 /* Standard-mandated substitution ops:
5756 * ${var?word} - indicate error if unset
5757 * If var is unset, word (or a message indicating it is unset
5758 * if word is null) is written to standard error
5759 * and the shell exits with a non-zero exit status.
5760 * Otherwise, the value of var is substituted.
5761 * ${var-word} - use default value
5762 * If var is unset, word is substituted.
5763 * ${var=word} - assign and use default value
5764 * If var is unset, word is assigned to var.
5765 * In all cases, final value of var is substituted.
5766 * ${var+word} - use alternative value
5767 * If var is unset, null is substituted.
5768 * Otherwise, word is substituted.
5770 * Word is subjected to tilde expansion, parameter expansion,
5771 * command substitution, and arithmetic expansion.
5772 * If word is not needed, it is not expanded.
5774 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5775 * but also treat null var as if it is unset.
5777 int use_word = (!val || ((exp_save == ':') && !val[0]));
5779 use_word = !use_word;
5780 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5781 (exp_save == ':') ? "true" : "false", use_word);
5783 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5785 exp_word = to_be_freed;
5786 if (exp_op == '?') {
5787 /* mimic bash message */
5788 die_if_script("%s: %s",
5790 exp_word[0] ? exp_word : "parameter null or not set"
5792 //TODO: how interactive bash aborts expansion mid-command?
5797 if (exp_op == '=') {
5798 /* ${var=[word]} or ${var:=[word]} */
5799 if (isdigit(var[0]) || var[0] == '#') {
5800 /* mimic bash message */
5801 die_if_script("$%s: cannot assign in this way", var);
5804 char *new_var = xasprintf("%s=%s", var, val);
5805 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5809 } /* one of "-=+?" */
5811 *exp_saveptr = exp_save;
5817 *to_be_freed_pp = to_be_freed;
5821 /* Expand all variable references in given string, adding words to list[]
5822 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5823 * to be filled). This routine is extremely tricky: has to deal with
5824 * variables/parameters with whitespace, $* and $@, and constructs like
5825 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5826 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5828 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5829 * expansion of right-hand side of assignment == 1-element expand.
5831 char cant_be_null = 0; /* only bit 0x80 matters */
5832 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5835 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5836 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5837 debug_print_list("expand_vars_to_list", output, n);
5838 n = o_save_ptr(output, n);
5839 debug_print_list("expand_vars_to_list[0]", output, n);
5841 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5843 char *to_be_freed = NULL;
5844 const char *val = NULL;
5845 #if ENABLE_HUSH_TICK
5846 o_string subst_result = NULL_O_STRING;
5848 #if ENABLE_FEATURE_SH_MATH
5849 char arith_buf[sizeof(arith_t)*3 + 2];
5853 o_addchr(output, '\0');
5854 n = o_save_ptr(output, n);
5858 o_addblock(output, arg, p - arg);
5859 debug_print_list("expand_vars_to_list[1]", output, n);
5861 p = strchr(p, SPECIAL_VAR_SYMBOL);
5863 /* Fetch special var name (if it is indeed one of them)
5864 * and quote bit, force the bit on if singleword expansion -
5865 * important for not getting v=$@ expand to many words. */
5866 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5868 /* Is this variable quoted and thus expansion can't be null?
5869 * "$@" is special. Even if quoted, it can still
5870 * expand to nothing (not even an empty string),
5871 * thus it is excluded. */
5872 if ((first_ch & 0x7f) != '@')
5873 cant_be_null |= first_ch;
5875 switch (first_ch & 0x7f) {
5876 /* Highest bit in first_ch indicates that var is double-quoted */
5880 if (!G.global_argv[1])
5883 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5884 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5885 while (G.global_argv[i]) {
5886 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5887 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5888 if (G.global_argv[i++][0] && G.global_argv[i]) {
5889 /* this argv[] is not empty and not last:
5890 * put terminating NUL, start new word */
5891 o_addchr(output, '\0');
5892 debug_print_list("expand_vars_to_list[2]", output, n);
5893 n = o_save_ptr(output, n);
5894 debug_print_list("expand_vars_to_list[3]", output, n);
5898 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5899 * and in this case should treat it like '$*' - see 'else...' below */
5900 if (first_ch == ('@'|0x80) /* quoted $@ */
5901 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5904 o_addQstr(output, G.global_argv[i]);
5905 if (++i >= G.global_argc)
5907 o_addchr(output, '\0');
5908 debug_print_list("expand_vars_to_list[4]", output, n);
5909 n = o_save_ptr(output, n);
5911 } else { /* quoted $* (or v="$@" case): add as one word */
5913 o_addQstr(output, G.global_argv[i]);
5914 if (!G.global_argv[++i])
5917 o_addchr(output, G.ifs[0]);
5919 output->has_quoted_part = 1;
5923 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5924 /* "Empty variable", used to make "" etc to not disappear */
5925 output->has_quoted_part = 1;
5927 cant_be_null = 0x80;
5929 #if ENABLE_HUSH_TICK
5930 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5931 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5933 /* Can't just stuff it into output o_string,
5934 * expanded result may need to be globbed
5936 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5937 G.last_exitcode = process_command_subs(&subst_result, arg);
5938 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5939 val = subst_result.data;
5942 #if ENABLE_FEATURE_SH_MATH
5943 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5946 arg++; /* skip '+' */
5947 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5948 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5949 res = expand_and_evaluate_arith(arg, NULL);
5950 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5951 sprintf(arith_buf, ARITH_FMT, res);
5957 val = expand_one_var(&to_be_freed, arg, &p);
5958 IF_HUSH_TICK(store_val:)
5959 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5960 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5961 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5962 if (val && val[0]) {
5963 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5966 } else { /* quoted $VAR, val will be appended below */
5967 output->has_quoted_part = 1;
5968 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5969 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5972 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5974 if (val && val[0]) {
5975 o_addQstr(output, val);
5979 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5980 * Do the check to avoid writing to a const string. */
5981 if (*p != SPECIAL_VAR_SYMBOL)
5982 *p = SPECIAL_VAR_SYMBOL;
5984 #if ENABLE_HUSH_TICK
5985 o_free(&subst_result);
5988 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5992 o_addchr(output, '\0');
5993 n = o_save_ptr(output, n);
5995 debug_print_list("expand_vars_to_list[a]", output, n);
5996 /* this part is literal, and it was already pre-quoted
5997 * if needed (much earlier), do not use o_addQstr here! */
5998 o_addstr_with_NUL(output, arg);
5999 debug_print_list("expand_vars_to_list[b]", output, n);
6000 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6001 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6004 /* allow to reuse list[n] later without re-growth */
6005 output->has_empty_slot = 1;
6007 o_addchr(output, '\0');
6013 static char **expand_variables(char **argv, unsigned expflags)
6017 o_string output = NULL_O_STRING;
6019 output.o_expflags = expflags;
6023 n = expand_vars_to_list(&output, n, *argv);
6026 debug_print_list("expand_variables", &output, n);
6028 /* output.data (malloced in one block) gets returned in "list" */
6029 list = o_finalize_list(&output, n);
6030 debug_print_strings("expand_variables[1]", list);
6034 static char **expand_strvec_to_strvec(char **argv)
6036 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6040 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6042 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6046 /* Used for expansion of right hand of assignments,
6047 * $((...)), heredocs, variable espansion parts.
6049 * NB: should NOT do globbing!
6050 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6052 static char *expand_string_to_string(const char *str, int do_unbackslash)
6054 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6055 const int do_unbackslash = 1;
6057 char *argv[2], **list;
6059 debug_printf_expand("string_to_string<='%s'\n", str);
6060 /* This is generally an optimization, but it also
6061 * handles "", which otherwise trips over !list[0] check below.
6062 * (is this ever happens that we actually get str="" here?)
6064 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6065 //TODO: Can use on strings with \ too, just unbackslash() them?
6066 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6067 return xstrdup(str);
6070 argv[0] = (char*)str;
6072 list = expand_variables(argv, do_unbackslash
6073 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6074 : EXP_FLAG_SINGLEWORD
6077 if (!list[0] || list[1])
6078 bb_error_msg_and_die("BUG in varexp2");
6079 /* actually, just move string 2*sizeof(char*) bytes back */
6080 overlapping_strcpy((char*)list, list[0]);
6082 unbackslash((char*)list);
6083 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6087 /* Used for "eval" builtin and case string */
6088 static char* expand_strvec_to_string(char **argv)
6092 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6093 /* Convert all NULs to spaces */
6098 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6099 bb_error_msg_and_die("BUG in varexp3");
6100 /* bash uses ' ' regardless of $IFS contents */
6105 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6106 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6110 static char **expand_assignments(char **argv, int count)
6115 G.expanded_assignments = p = NULL;
6116 /* Expand assignments into one string each */
6117 for (i = 0; i < count; i++) {
6118 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6120 G.expanded_assignments = NULL;
6125 static void switch_off_special_sigs(unsigned mask)
6128 while ((mask >>= 1) != 0) {
6132 #if ENABLE_HUSH_TRAP
6134 if (G_traps[sig] && !G_traps[sig][0])
6135 /* trap is '', has to remain SIG_IGN */
6138 G_traps[sig] = NULL;
6141 /* We are here only if no trap or trap was not '' */
6142 install_sighandler(sig, SIG_DFL);
6148 void re_execute_shell(char ***to_free, const char *s,
6149 char *g_argv0, char **g_argv,
6150 char **builtin_argv) NORETURN;
6152 static void reset_traps_to_defaults(void)
6154 /* This function is always called in a child shell
6155 * after fork (not vfork, NOMMU doesn't use this function).
6157 IF_HUSH_TRAP(unsigned sig;)
6160 /* Child shells are not interactive.
6161 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6162 * Testcase: (while :; do :; done) + ^Z should background.
6163 * Same goes for SIGTERM, SIGHUP, SIGINT.
6165 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6166 if (!G_traps && !mask)
6167 return; /* already no traps and no special sigs */
6169 /* Switch off special sigs */
6170 switch_off_special_sigs(mask);
6171 # if ENABLE_HUSH_JOB
6172 G_fatal_sig_mask = 0;
6174 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6175 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6176 * remain set in G.special_sig_mask */
6178 # if ENABLE_HUSH_TRAP
6182 /* Reset all sigs to default except ones with empty traps */
6183 for (sig = 0; sig < NSIG; sig++) {
6185 continue; /* no trap: nothing to do */
6186 if (!G_traps[sig][0])
6187 continue; /* empty trap: has to remain SIG_IGN */
6188 /* sig has non-empty trap, reset it: */
6190 G_traps[sig] = NULL;
6191 /* There is no signal for trap 0 (EXIT) */
6194 install_sighandler(sig, pick_sighandler(sig));
6201 static void re_execute_shell(char ***to_free, const char *s,
6202 char *g_argv0, char **g_argv,
6203 char **builtin_argv) NORETURN;
6204 static void re_execute_shell(char ***to_free, const char *s,
6205 char *g_argv0, char **g_argv,
6206 char **builtin_argv)
6208 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6209 /* delims + 2 * (number of bytes in printed hex numbers) */
6210 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6211 char *heredoc_argv[4];
6212 struct variable *cur;
6213 # if ENABLE_HUSH_FUNCTIONS
6214 struct function *funcp;
6218 unsigned long long empty_trap_mask;
6220 if (!g_argv0) { /* heredoc */
6221 argv = heredoc_argv;
6222 argv[0] = (char *) G.argv0_for_re_execing;
6223 argv[1] = (char *) "-<";
6224 argv[2] = (char *) s;
6226 pp = &argv[3]; /* used as pointer to empty environment */
6232 if (pp) while (*pp++)
6235 empty_trap_mask = 0;
6238 for (sig = 1; sig < NSIG; sig++) {
6239 if (G_traps[sig] && !G_traps[sig][0])
6240 empty_trap_mask |= 1LL << sig;
6244 sprintf(param_buf, NOMMU_HACK_FMT
6245 , (unsigned) G.root_pid
6246 , (unsigned) G.root_ppid
6247 , (unsigned) G.last_bg_pid
6248 , (unsigned) G.last_exitcode
6251 IF_HUSH_LOOPS(, G.depth_of_loop)
6253 # undef NOMMU_HACK_FMT
6254 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6255 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6258 for (cur = G.top_var; cur; cur = cur->next) {
6259 if (!cur->flg_export || cur->flg_read_only)
6262 # if ENABLE_HUSH_FUNCTIONS
6263 for (funcp = G.top_func; funcp; funcp = funcp->next)
6269 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6270 *pp++ = (char *) G.argv0_for_re_execing;
6272 for (cur = G.top_var; cur; cur = cur->next) {
6273 if (strcmp(cur->varstr, hush_version_str) == 0)
6275 if (cur->flg_read_only) {
6276 *pp++ = (char *) "-R";
6277 *pp++ = cur->varstr;
6278 } else if (!cur->flg_export) {
6279 *pp++ = (char *) "-V";
6280 *pp++ = cur->varstr;
6283 # if ENABLE_HUSH_FUNCTIONS
6284 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6285 *pp++ = (char *) "-F";
6286 *pp++ = funcp->name;
6287 *pp++ = funcp->body_as_string;
6290 /* We can pass activated traps here. Say, -Tnn:trap_string
6292 * However, POSIX says that subshells reset signals with traps
6294 * I tested bash-3.2 and it not only does that with true subshells
6295 * of the form ( list ), but with any forked children shells.
6296 * I set trap "echo W" WINCH; and then tried:
6298 * { echo 1; sleep 20; echo 2; } &
6299 * while true; do echo 1; sleep 20; echo 2; break; done &
6300 * true | { echo 1; sleep 20; echo 2; } | cat
6302 * In all these cases sending SIGWINCH to the child shell
6303 * did not run the trap. If I add trap "echo V" WINCH;
6304 * _inside_ group (just before echo 1), it works.
6306 * I conclude it means we don't need to pass active traps here.
6308 *pp++ = (char *) "-c";
6311 while (*++builtin_argv)
6312 *pp++ = *builtin_argv;
6313 *pp++ = (char *) "";
6318 /* *pp = NULL; - is already there */
6322 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6323 /* Don't propagate SIG_IGN to the child */
6324 if (SPECIAL_JOBSTOP_SIGS != 0)
6325 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6326 execve(bb_busybox_exec_path, argv, pp);
6327 /* Fallback. Useful for init=/bin/hush usage etc */
6328 if (argv[0][0] == '/')
6329 execve(argv[0], argv, pp);
6330 xfunc_error_retval = 127;
6331 bb_error_msg_and_die("can't re-execute the shell");
6333 #endif /* !BB_MMU */
6336 static int run_and_free_list(struct pipe *pi);
6338 /* Executing from string: eval, sh -c '...'
6339 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6340 * end_trigger controls how often we stop parsing
6341 * NUL: parse all, execute, return
6342 * ';': parse till ';' or newline, execute, repeat till EOF
6344 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6346 /* Why we need empty flag?
6347 * An obscure corner case "false; ``; echo $?":
6348 * empty command in `` should still set $? to 0.
6349 * But we can't just set $? to 0 at the start,
6350 * this breaks "false; echo `echo $?`" case.
6354 struct pipe *pipe_list;
6356 #if ENABLE_HUSH_INTERACTIVE
6357 if (end_trigger == ';')
6358 inp->promptmode = 0; /* PS1 */
6360 pipe_list = parse_stream(NULL, inp, end_trigger);
6361 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6362 /* If we are in "big" script
6363 * (not in `cmd` or something similar)...
6365 if (pipe_list == ERR_PTR && end_trigger == ';') {
6366 /* Discard cached input (rest of line) */
6367 int ch = inp->last_char;
6368 while (ch != EOF && ch != '\n') {
6369 //bb_error_msg("Discarded:'%c'", ch);
6374 /* This stream isn't empty */
6378 if (!pipe_list && empty)
6379 G.last_exitcode = 0;
6382 debug_print_tree(pipe_list, 0);
6383 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6384 run_and_free_list(pipe_list);
6386 if (G_flag_return_in_progress == 1)
6391 static void parse_and_run_string(const char *s)
6393 struct in_str input;
6394 setup_string_in_str(&input, s);
6395 parse_and_run_stream(&input, '\0');
6398 static void parse_and_run_file(FILE *f)
6400 struct in_str input;
6401 setup_file_in_str(&input, f);
6402 parse_and_run_stream(&input, ';');
6405 #if ENABLE_HUSH_TICK
6406 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6411 char **to_free = NULL;
6415 pid = BB_MMU ? xfork() : xvfork();
6416 if (pid == 0) { /* child */
6417 disable_restore_tty_pgrp_on_exit();
6418 /* Process substitution is not considered to be usual
6419 * 'command execution'.
6420 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6427 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6428 close(channel[0]); /* NB: close _first_, then move fd! */
6429 xmove_fd(channel[1], 1);
6430 /* Prevent it from trying to handle ctrl-z etc */
6431 IF_HUSH_JOB(G.run_list_level = 1;)
6432 # if ENABLE_HUSH_TRAP
6433 /* Awful hack for `trap` or $(trap).
6435 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6436 * contains an example where "trap" is executed in a subshell:
6438 * save_traps=$(trap)
6440 * eval "$save_traps"
6442 * Standard does not say that "trap" in subshell shall print
6443 * parent shell's traps. It only says that its output
6444 * must have suitable form, but then, in the above example
6445 * (which is not supposed to be normative), it implies that.
6447 * bash (and probably other shell) does implement it
6448 * (traps are reset to defaults, but "trap" still shows them),
6449 * but as a result, "trap" logic is hopelessly messed up:
6452 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6453 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6454 * # true | trap <--- trap is in subshell - no output (ditto)
6455 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6456 * trap -- 'echo Ho' SIGWINCH
6457 * # echo `(trap)` <--- in subshell in subshell - output
6458 * trap -- 'echo Ho' SIGWINCH
6459 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6460 * trap -- 'echo Ho' SIGWINCH
6462 * The rules when to forget and when to not forget traps
6463 * get really complex and nonsensical.
6465 * Our solution: ONLY bare $(trap) or `trap` is special.
6467 s = skip_whitespace(s);
6468 if (is_prefixed_with(s, "trap")
6469 && skip_whitespace(s + 4)[0] == '\0'
6471 static const char *const argv[] = { NULL, NULL };
6472 builtin_trap((char**)argv);
6473 fflush_all(); /* important */
6478 reset_traps_to_defaults();
6479 parse_and_run_string(s);
6480 _exit(G.last_exitcode);
6482 /* We re-execute after vfork on NOMMU. This makes this script safe:
6483 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6484 * huge=`cat BIG` # was blocking here forever
6487 re_execute_shell(&to_free,
6497 # if ENABLE_HUSH_FAST
6499 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6500 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6501 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6503 enable_restore_tty_pgrp_on_exit();
6508 return remember_FILE(xfdopen_for_read(channel[0]));
6511 /* Return code is exit status of the process that is run. */
6512 static int process_command_subs(o_string *dest, const char *s)
6515 struct in_str pipe_str;
6517 int status, ch, eol_cnt;
6519 fp = generate_stream_from_string(s, &pid);
6521 /* Now send results of command back into original context */
6522 setup_file_in_str(&pipe_str, fp);
6524 while ((ch = i_getch(&pipe_str)) != EOF) {
6530 o_addchr(dest, '\n');
6533 o_addQchr(dest, ch);
6536 debug_printf("done reading from `cmd` pipe, closing it\n");
6537 fclose_and_forget(fp);
6538 /* We need to extract exitcode. Test case
6539 * "true; echo `sleep 1; false` $?"
6541 safe_waitpid(pid, &status, 0);
6542 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6543 return WEXITSTATUS(status);
6545 #endif /* ENABLE_HUSH_TICK */
6548 static void setup_heredoc(struct redir_struct *redir)
6550 struct fd_pair pair;
6553 /* the _body_ of heredoc (misleading field name) */
6554 const char *heredoc = redir->rd_filename;
6561 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6562 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6566 len = strlen(heredoc);
6568 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6570 xmove_fd(pair.rd, redir->rd_fd);
6572 /* Try writing without forking. Newer kernels have
6573 * dynamically growing pipes. Must use non-blocking write! */
6576 written = write(pair.wr, heredoc, len);
6587 ndelay_off(pair.wr);
6589 /* Okay, pipe buffer was not big enough */
6590 /* Note: we must not create a stray child (bastard? :)
6591 * for the unsuspecting parent process. Child creates a grandchild
6592 * and exits before parent execs the process which consumes heredoc
6593 * (that exec happens after we return from this function) */
6600 disable_restore_tty_pgrp_on_exit();
6601 pid = BB_MMU ? xfork() : xvfork();
6605 close(redir->rd_fd); /* read side of the pipe */
6607 full_write(pair.wr, heredoc, len); /* may loop or block */
6610 /* Delegate blocking writes to another process */
6611 xmove_fd(pair.wr, STDOUT_FILENO);
6612 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6616 #if ENABLE_HUSH_FAST
6618 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6620 enable_restore_tty_pgrp_on_exit();
6626 wait(NULL); /* wait till child has died */
6632 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6633 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6636 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6640 if (sq) while (sq[i].orig_fd >= 0) {
6641 /* If we collide with an already moved fd... */
6642 if (fd == sq[i].moved_to) {
6643 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6644 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6645 if (sq[i].moved_to < 0) /* what? */
6649 if (fd == sq[i].orig_fd) {
6650 /* Example: echo Hello >/dev/null 1>&2 */
6651 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6657 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6659 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6660 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6661 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6662 if (sq[i].moved_to < 0 && errno != EBADF)
6664 sq[i+1].orig_fd = -1; /* end marker */
6668 /* fd: redirect wants this fd to be used (e.g. 3>file).
6669 * Move all conflicting internally used fds,
6670 * and remember them so that we can restore them later.
6672 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6674 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6677 #if ENABLE_HUSH_INTERACTIVE
6678 if (fd != 0 && fd == G.interactive_fd) {
6679 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6680 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6681 return 1; /* "we closed fd" */
6684 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6685 * (1) Redirect in a forked child. No need to save FILEs' fds,
6686 * we aren't going to use them anymore, ok to trash.
6687 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6688 * but how are we doing to restore them?
6689 * "fileno(fd) = new_fd" can't be done.
6694 /* If this one of script's fds? */
6695 if (save_FILEs_on_redirect(fd, avoid_fd))
6696 return 1; /* yes. "we closed fd" */
6698 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6699 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6700 return 0; /* "we did not close fd" */
6703 static void restore_redirects(struct squirrel *sq)
6708 while (sq[i].orig_fd >= 0) {
6709 if (sq[i].moved_to >= 0) {
6710 /* We simply die on error */
6711 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6712 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6714 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6715 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6716 close(sq[i].orig_fd);
6723 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6725 restore_redirected_FILEs();
6728 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6729 * and stderr if they are redirected. */
6730 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6733 struct redir_struct *redir;
6735 for (redir = prog->redirects; redir; redir = redir->next) {
6736 if (redir->rd_type == REDIRECT_HEREDOC2) {
6737 /* "rd_fd<<HERE" case */
6738 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6739 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6741 debug_printf_parse("set heredoc '%s'\n",
6742 redir->rd_filename);
6743 setup_heredoc(redir);
6747 if (redir->rd_dup == REDIRFD_TO_FILE) {
6748 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6750 if (redir->rd_filename == NULL) {
6753 * "cmd >" (no filename)
6754 * "cmd > <file" (2nd redirect starts too early)
6756 die_if_script("syntax error: %s", "invalid redirect");
6759 mode = redir_table[redir->rd_type].mode;
6760 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6761 openfd = open_or_warn(p, mode);
6764 /* Error message from open_or_warn can be lost
6765 * if stderr has been redirected, but bash
6766 * and ash both lose it as well
6767 * (though zsh doesn't!)
6772 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6773 openfd = redir->rd_dup;
6776 if (openfd != redir->rd_fd) {
6777 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6778 if (openfd == REDIRFD_CLOSE) {
6779 /* "rd_fd >&-" means "close me" */
6781 /* ^^^ optimization: saving may already
6782 * have closed it. If not... */
6783 close(redir->rd_fd);
6786 xdup2(openfd, redir->rd_fd);
6787 if (redir->rd_dup == REDIRFD_TO_FILE)
6788 /* "rd_fd > FILE" */
6790 /* else: "rd_fd > rd_dup" */
6797 static char *find_in_path(const char *arg)
6800 const char *PATH = get_local_var_value("PATH");
6806 const char *end = strchrnul(PATH, ':');
6807 int sz = end - PATH; /* must be int! */
6811 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6813 /* We have xxx::yyyy in $PATH,
6814 * it means "use current dir" */
6817 if (access(ret, F_OK) == 0)
6830 static const struct built_in_command *find_builtin_helper(const char *name,
6831 const struct built_in_command *x,
6832 const struct built_in_command *end)
6835 if (strcmp(name, x->b_cmd) != 0) {
6839 debug_printf_exec("found builtin '%s'\n", name);
6844 static const struct built_in_command *find_builtin1(const char *name)
6846 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6848 static const struct built_in_command *find_builtin(const char *name)
6850 const struct built_in_command *x = find_builtin1(name);
6853 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6856 #if ENABLE_HUSH_FUNCTIONS
6857 static struct function **find_function_slot(const char *name)
6859 struct function **funcpp = &G.top_func;
6861 if (strcmp(name, (*funcpp)->name) == 0) {
6864 funcpp = &(*funcpp)->next;
6869 static const struct function *find_function(const char *name)
6871 const struct function *funcp = *find_function_slot(name);
6873 debug_printf_exec("found function '%s'\n", name);
6877 /* Note: takes ownership on name ptr */
6878 static struct function *new_function(char *name)
6880 struct function **funcpp = find_function_slot(name);
6881 struct function *funcp = *funcpp;
6883 if (funcp != NULL) {
6884 struct command *cmd = funcp->parent_cmd;
6885 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6887 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6889 /* Note: if !funcp->body, do not free body_as_string!
6890 * This is a special case of "-F name body" function:
6891 * body_as_string was not malloced! */
6893 free_pipe_list(funcp->body);
6895 free(funcp->body_as_string);
6899 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6900 cmd->argv[0] = funcp->name;
6901 cmd->group = funcp->body;
6903 cmd->group_as_string = funcp->body_as_string;
6907 debug_printf_exec("remembering new function '%s'\n", name);
6908 funcp = *funcpp = xzalloc(sizeof(*funcp));
6909 /*funcp->next = NULL;*/
6916 # if ENABLE_HUSH_UNSET
6917 static void unset_func(const char *name)
6919 struct function **funcpp = find_function_slot(name);
6920 struct function *funcp = *funcpp;
6922 if (funcp != NULL) {
6923 debug_printf_exec("freeing function '%s'\n", funcp->name);
6924 *funcpp = funcp->next;
6925 /* funcp is unlinked now, deleting it.
6926 * Note: if !funcp->body, the function was created by
6927 * "-F name body", do not free ->body_as_string
6928 * and ->name as they were not malloced. */
6930 free_pipe_list(funcp->body);
6933 free(funcp->body_as_string);
6942 #define exec_function(to_free, funcp, argv) \
6943 exec_function(funcp, argv)
6945 static void exec_function(char ***to_free,
6946 const struct function *funcp,
6947 char **argv) NORETURN;
6948 static void exec_function(char ***to_free,
6949 const struct function *funcp,
6955 argv[0] = G.global_argv[0];
6956 G.global_argv = argv;
6957 G.global_argc = n = 1 + string_array_len(argv + 1);
6958 /* On MMU, funcp->body is always non-NULL */
6959 n = run_list(funcp->body);
6963 re_execute_shell(to_free,
6964 funcp->body_as_string,
6971 static int run_function(const struct function *funcp, char **argv)
6977 save_and_replace_G_args(&sv, argv);
6979 /* "we are in function, ok to use return" */
6980 sv_flg = G_flag_return_in_progress;
6981 G_flag_return_in_progress = -1;
6982 # if ENABLE_HUSH_LOCAL
6983 G.func_nest_level++;
6986 /* On MMU, funcp->body is always non-NULL */
6989 /* Function defined by -F */
6990 parse_and_run_string(funcp->body_as_string);
6991 rc = G.last_exitcode;
6995 rc = run_list(funcp->body);
6998 # if ENABLE_HUSH_LOCAL
7000 struct variable *var;
7001 struct variable **var_pp;
7003 var_pp = &G.top_var;
7004 while ((var = *var_pp) != NULL) {
7005 if (var->func_nest_level < G.func_nest_level) {
7006 var_pp = &var->next;
7010 if (var->flg_export)
7011 bb_unsetenv(var->varstr);
7012 /* Remove from global list */
7013 *var_pp = var->next;
7019 G.func_nest_level--;
7022 G_flag_return_in_progress = sv_flg;
7024 restore_G_args(&sv, argv);
7028 #endif /* ENABLE_HUSH_FUNCTIONS */
7032 #define exec_builtin(to_free, x, argv) \
7033 exec_builtin(x, argv)
7035 #define exec_builtin(to_free, x, argv) \
7036 exec_builtin(to_free, argv)
7038 static void exec_builtin(char ***to_free,
7039 const struct built_in_command *x,
7040 char **argv) NORETURN;
7041 static void exec_builtin(char ***to_free,
7042 const struct built_in_command *x,
7048 rcode = x->b_function(argv);
7053 /* On NOMMU, we must never block!
7054 * Example: { sleep 99 | read line; } & echo Ok
7056 re_execute_shell(to_free,
7065 static void execvp_or_die(char **argv) NORETURN;
7066 static void execvp_or_die(char **argv)
7069 debug_printf_exec("execing '%s'\n", argv[0]);
7070 /* Don't propagate SIG_IGN to the child */
7071 if (SPECIAL_JOBSTOP_SIGS != 0)
7072 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7073 execvp(argv[0], argv);
7075 if (errno == EACCES) e = 126;
7076 if (errno == ENOENT) e = 127;
7077 bb_perror_msg("can't execute '%s'", argv[0]);
7081 #if ENABLE_HUSH_MODE_X
7082 static void dump_cmd_in_x_mode(char **argv)
7084 if (G_x_mode && argv) {
7085 /* We want to output the line in one write op */
7093 len += strlen(argv[n++]) + 1;
7099 p += sprintf(p, " %s", argv[n++]);
7107 # define dump_cmd_in_x_mode(argv) ((void)0)
7111 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7112 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7113 #define pseudo_exec(nommu_save, command, argv_expanded) \
7114 pseudo_exec(command, argv_expanded)
7117 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7119 * Don't exit() here. If you don't exec, use _exit instead.
7120 * The at_exit handlers apparently confuse the calling process,
7121 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7123 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7124 char **argv, int assignment_cnt,
7125 char **argv_expanded) NORETURN;
7126 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7127 char **argv, int assignment_cnt,
7128 char **argv_expanded)
7132 new_env = expand_assignments(argv, assignment_cnt);
7133 dump_cmd_in_x_mode(new_env);
7135 if (!argv[assignment_cnt]) {
7136 /* Case when we are here: ... | var=val | ...
7137 * (note that we do not exit early, i.e., do not optimize out
7138 * expand_assignments(): think about ... | var=`sleep 1` | ...
7140 free_strings(new_env);
7141 _exit(EXIT_SUCCESS);
7145 set_vars_and_save_old(new_env);
7146 free(new_env); /* optional */
7147 /* we can also destroy set_vars_and_save_old's return value,
7150 nommu_save->new_env = new_env;
7151 nommu_save->old_vars = set_vars_and_save_old(new_env);
7154 if (argv_expanded) {
7155 argv = argv_expanded;
7157 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7159 nommu_save->argv = argv;
7162 dump_cmd_in_x_mode(argv);
7164 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7165 if (strchr(argv[0], '/') != NULL)
7169 /* Check if the command matches any of the builtins.
7170 * Depending on context, this might be redundant. But it's
7171 * easier to waste a few CPU cycles than it is to figure out
7172 * if this is one of those cases.
7175 /* On NOMMU, it is more expensive to re-execute shell
7176 * just in order to run echo or test builtin.
7177 * It's better to skip it here and run corresponding
7178 * non-builtin later. */
7179 const struct built_in_command *x;
7180 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7182 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7185 #if ENABLE_HUSH_FUNCTIONS
7186 /* Check if the command matches any functions */
7188 const struct function *funcp = find_function(argv[0]);
7190 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7195 #if ENABLE_FEATURE_SH_STANDALONE
7196 /* Check if the command matches any busybox applets */
7198 int a = find_applet_by_name(argv[0]);
7200 # if BB_MMU /* see above why on NOMMU it is not allowed */
7201 if (APPLET_IS_NOEXEC(a)) {
7202 /* Do not leak open fds from opened script files etc */
7203 close_all_FILE_list();
7204 debug_printf_exec("running applet '%s'\n", argv[0]);
7205 run_applet_no_and_exit(a, argv[0], argv);
7208 /* Re-exec ourselves */
7209 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7210 /* Don't propagate SIG_IGN to the child */
7211 if (SPECIAL_JOBSTOP_SIGS != 0)
7212 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7213 execv(bb_busybox_exec_path, argv);
7214 /* If they called chroot or otherwise made the binary no longer
7215 * executable, fall through */
7220 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7223 execvp_or_die(argv);
7226 /* Called after [v]fork() in run_pipe
7228 static void pseudo_exec(nommu_save_t *nommu_save,
7229 struct command *command,
7230 char **argv_expanded) NORETURN;
7231 static void pseudo_exec(nommu_save_t *nommu_save,
7232 struct command *command,
7233 char **argv_expanded)
7235 if (command->argv) {
7236 pseudo_exec_argv(nommu_save, command->argv,
7237 command->assignment_cnt, argv_expanded);
7240 if (command->group) {
7241 /* Cases when we are here:
7244 * ... | ( list ) | ...
7245 * ... | { list } | ...
7249 debug_printf_exec("pseudo_exec: run_list\n");
7250 reset_traps_to_defaults();
7251 rcode = run_list(command->group);
7252 /* OK to leak memory by not calling free_pipe_list,
7253 * since this process is about to exit */
7256 re_execute_shell(&nommu_save->argv_from_re_execing,
7257 command->group_as_string,
7264 /* Case when we are here: ... | >file */
7265 debug_printf_exec("pseudo_exec'ed null command\n");
7266 _exit(EXIT_SUCCESS);
7270 static const char *get_cmdtext(struct pipe *pi)
7276 /* This is subtle. ->cmdtext is created only on first backgrounding.
7277 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7278 * On subsequent bg argv is trashed, but we won't use it */
7282 argv = pi->cmds[0].argv;
7284 pi->cmdtext = xzalloc(1);
7289 len += strlen(*argv) + 1;
7293 argv = pi->cmds[0].argv;
7295 p = stpcpy(p, *argv);
7302 static void remove_job_from_table(struct pipe *pi)
7304 struct pipe *prev_pipe;
7306 if (pi == G.job_list) {
7307 G.job_list = pi->next;
7309 prev_pipe = G.job_list;
7310 while (prev_pipe->next != pi)
7311 prev_pipe = prev_pipe->next;
7312 prev_pipe->next = pi->next;
7316 G.last_jobid = G.job_list->jobid;
7319 static void delete_finished_job(struct pipe *pi)
7321 remove_job_from_table(pi);
7325 static void clean_up_last_dead_job(void)
7327 if (G.job_list && !G.job_list->alive_cmds)
7328 delete_finished_job(G.job_list);
7331 static void insert_job_into_table(struct pipe *pi)
7333 struct pipe *job, **jobp;
7336 clean_up_last_dead_job();
7338 /* Find the end of the list, and find next job ID to use */
7341 while ((job = *jobp) != NULL) {
7348 /* Create a new job struct at the end */
7349 job = *jobp = xmemdup(pi, sizeof(*pi));
7351 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7352 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7353 for (i = 0; i < pi->num_cmds; i++) {
7354 job->cmds[i].pid = pi->cmds[i].pid;
7355 /* all other fields are not used and stay zero */
7357 job->cmdtext = xstrdup(get_cmdtext(pi));
7359 if (G_interactive_fd)
7360 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7361 G.last_jobid = job->jobid;
7365 static int job_exited_or_stopped(struct pipe *pi)
7369 if (pi->alive_cmds != pi->stopped_cmds)
7372 /* All processes in fg pipe have exited or stopped */
7376 rcode = pi->cmds[i].cmd_exitcode;
7377 /* usually last process gives overall exitstatus,
7378 * but with "set -o pipefail", last *failed* process does */
7379 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7382 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7386 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7393 dead = WIFEXITED(status) || WIFSIGNALED(status);
7396 if (WIFSTOPPED(status))
7397 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7398 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7399 if (WIFSIGNALED(status))
7400 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7401 childpid, WTERMSIG(status), WEXITSTATUS(status));
7402 if (WIFEXITED(status))
7403 debug_printf_jobs("pid %d exited, exitcode %d\n",
7404 childpid, WEXITSTATUS(status));
7406 /* Were we asked to wait for a fg pipe? */
7408 i = fg_pipe->num_cmds;
7413 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7414 if (fg_pipe->cmds[i].pid != childpid)
7418 fg_pipe->cmds[i].pid = 0;
7419 fg_pipe->alive_cmds--;
7420 ex = WEXITSTATUS(status);
7421 /* bash prints killer signal's name for *last*
7422 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7423 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7425 if (WIFSIGNALED(status)) {
7426 int sig = WTERMSIG(status);
7427 if (i == fg_pipe->num_cmds-1)
7428 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7429 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7430 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7431 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7432 * Maybe we need to use sig | 128? */
7435 fg_pipe->cmds[i].cmd_exitcode = ex;
7437 fg_pipe->stopped_cmds++;
7439 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7440 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7441 rcode = job_exited_or_stopped(fg_pipe);
7443 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7444 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7445 * and "killall -STOP cat" */
7446 if (G_interactive_fd) {
7448 if (fg_pipe->alive_cmds != 0)
7449 insert_job_into_table(fg_pipe);
7453 if (fg_pipe->alive_cmds == 0)
7456 /* There are still running processes in the fg_pipe */
7459 /* It wasn't in fg_pipe, look for process in bg pipes */
7463 /* We were asked to wait for bg or orphaned children */
7464 /* No need to remember exitcode in this case */
7465 for (pi = G.job_list; pi; pi = pi->next) {
7466 for (i = 0; i < pi->num_cmds; i++) {
7467 if (pi->cmds[i].pid == childpid)
7468 goto found_pi_and_prognum;
7471 /* Happens when shell is used as init process (init=/bin/sh) */
7472 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7473 return -1; /* this wasn't a process from fg_pipe */
7475 found_pi_and_prognum:
7478 int rcode = WEXITSTATUS(status);
7479 if (WIFSIGNALED(status))
7480 rcode = 128 + WTERMSIG(status);
7481 pi->cmds[i].cmd_exitcode = rcode;
7482 if (G.last_bg_pid == pi->cmds[i].pid)
7483 G.last_bg_pid_exitcode = rcode;
7484 pi->cmds[i].pid = 0;
7486 if (!pi->alive_cmds) {
7487 if (G_interactive_fd) {
7488 printf(JOB_STATUS_FORMAT, pi->jobid,
7489 "Done", pi->cmdtext);
7490 delete_finished_job(pi);
7493 * bash deletes finished jobs from job table only in interactive mode,
7494 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7495 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7496 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7497 * We only retain one "dead" job, if it's the single job on the list.
7498 * This covers most of real-world scenarios where this is useful.
7500 if (pi != G.job_list)
7501 delete_finished_job(pi);
7509 return -1; /* this wasn't a process from fg_pipe */
7512 /* Check to see if any processes have exited -- if they have,
7513 * figure out why and see if a job has completed.
7515 * If non-NULL fg_pipe: wait for its completion or stop.
7516 * Return its exitcode or zero if stopped.
7518 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7519 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7520 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7521 * or 0 if no children changed status.
7523 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7524 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7525 * or 0 if no children changed status.
7527 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7533 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7535 attributes = WUNTRACED;
7536 if (fg_pipe == NULL)
7537 attributes |= WNOHANG;
7540 #if ENABLE_HUSH_FAST
7541 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7542 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7543 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7544 /* There was neither fork nor SIGCHLD since last waitpid */
7545 /* Avoid doing waitpid syscall if possible */
7546 if (!G.we_have_children) {
7550 if (fg_pipe == NULL) { /* is WNOHANG set? */
7551 /* We have children, but they did not exit
7552 * or stop yet (we saw no SIGCHLD) */
7555 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7559 /* Do we do this right?
7560 * bash-3.00# sleep 20 | false
7562 * [3]+ Stopped sleep 20 | false
7563 * bash-3.00# echo $?
7564 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7565 * [hush 1.14.0: yes we do it right]
7569 #if ENABLE_HUSH_FAST
7571 i = G.count_SIGCHLD;
7573 childpid = waitpid(-1, &status, attributes);
7574 if (childpid <= 0) {
7575 if (childpid && errno != ECHILD)
7576 bb_perror_msg("waitpid");
7577 #if ENABLE_HUSH_FAST
7578 else { /* Until next SIGCHLD, waitpid's are useless */
7579 G.we_have_children = (childpid == 0);
7580 G.handled_SIGCHLD = i;
7581 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7584 /* ECHILD (no children), or 0 (no change in children status) */
7588 rcode = process_wait_result(fg_pipe, childpid, status);
7590 /* fg_pipe exited or stopped */
7593 if (childpid == waitfor_pid) {
7594 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7595 rcode = WEXITSTATUS(status);
7596 if (WIFSIGNALED(status))
7597 rcode = 128 + WTERMSIG(status);
7598 if (WIFSTOPPED(status))
7599 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7600 rcode = 128 + WSTOPSIG(status);
7602 break; /* "wait PID" called us, give it exitcode+1 */
7604 /* This wasn't one of our processes, or */
7605 /* fg_pipe still has running processes, do waitpid again */
7606 } /* while (waitpid succeeds)... */
7612 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7615 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7616 if (G_saved_tty_pgrp) {
7617 /* Job finished, move the shell to the foreground */
7618 p = getpgrp(); /* our process group id */
7619 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7620 tcsetpgrp(G_interactive_fd, p);
7626 /* Start all the jobs, but don't wait for anything to finish.
7629 * Return code is normally -1, when the caller has to wait for children
7630 * to finish to determine the exit status of the pipe. If the pipe
7631 * is a simple builtin command, however, the action is done by the
7632 * time run_pipe returns, and the exit code is provided as the
7635 * Returns -1 only if started some children. IOW: we have to
7636 * mask out retvals of builtins etc with 0xff!
7638 * The only case when we do not need to [v]fork is when the pipe
7639 * is single, non-backgrounded, non-subshell command. Examples:
7640 * cmd ; ... { list } ; ...
7641 * cmd && ... { list } && ...
7642 * cmd || ... { list } || ...
7643 * If it is, then we can run cmd as a builtin, NOFORK,
7644 * or (if SH_STANDALONE) an applet, and we can run the { list }
7645 * with run_list. If it isn't one of these, we fork and exec cmd.
7647 * Cases when we must fork:
7648 * non-single: cmd | cmd
7649 * backgrounded: cmd & { list } &
7650 * subshell: ( list ) [&]
7652 #if !ENABLE_HUSH_MODE_X
7653 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7654 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7656 static int redirect_and_varexp_helper(char ***new_env_p,
7657 struct variable **old_vars_p,
7658 struct command *command,
7659 struct squirrel **sqp,
7660 char **argv_expanded)
7662 /* setup_redirects acts on file descriptors, not FILEs.
7663 * This is perfect for work that comes after exec().
7664 * Is it really safe for inline use? Experimentally,
7665 * things seem to work. */
7666 int rcode = setup_redirects(command, sqp);
7668 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7669 *new_env_p = new_env;
7670 dump_cmd_in_x_mode(new_env);
7671 dump_cmd_in_x_mode(argv_expanded);
7673 *old_vars_p = set_vars_and_save_old(new_env);
7677 static NOINLINE int run_pipe(struct pipe *pi)
7679 static const char *const null_ptr = NULL;
7683 struct command *command;
7684 char **argv_expanded;
7686 struct squirrel *squirrel = NULL;
7689 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7692 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7693 * Result should be 3 lines: q w e, qwe, q w e
7695 G.ifs = get_local_var_value("IFS");
7699 IF_HUSH_JOB(pi->pgrp = -1;)
7700 pi->stopped_cmds = 0;
7701 command = &pi->cmds[0];
7702 argv_expanded = NULL;
7704 if (pi->num_cmds != 1
7705 || pi->followup == PIPE_BG
7706 || command->cmd_type == CMD_SUBSHELL
7713 debug_printf_exec(": group:%p argv:'%s'\n",
7714 command->group, command->argv ? command->argv[0] : "NONE");
7716 if (command->group) {
7717 #if ENABLE_HUSH_FUNCTIONS
7718 if (command->cmd_type == CMD_FUNCDEF) {
7719 /* "executing" func () { list } */
7720 struct function *funcp;
7722 funcp = new_function(command->argv[0]);
7723 /* funcp->name is already set to argv[0] */
7724 funcp->body = command->group;
7726 funcp->body_as_string = command->group_as_string;
7727 command->group_as_string = NULL;
7729 command->group = NULL;
7730 command->argv[0] = NULL;
7731 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7732 funcp->parent_cmd = command;
7733 command->child_func = funcp;
7735 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7737 return EXIT_SUCCESS;
7741 debug_printf("non-subshell group\n");
7742 rcode = 1; /* exitcode if redir failed */
7743 if (setup_redirects(command, &squirrel) == 0) {
7744 debug_printf_exec(": run_list\n");
7745 rcode = run_list(command->group) & 0xff;
7747 restore_redirects(squirrel);
7748 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7750 debug_printf_exec("run_pipe: return %d\n", rcode);
7754 argv = command->argv ? command->argv : (char **) &null_ptr;
7756 const struct built_in_command *x;
7757 #if ENABLE_HUSH_FUNCTIONS
7758 const struct function *funcp;
7762 char **new_env = NULL;
7763 struct variable *old_vars = NULL;
7765 if (argv[command->assignment_cnt] == NULL) {
7766 /* Assignments, but no command */
7767 /* Ensure redirects take effect (that is, create files).
7768 * Try "a=t >file" */
7769 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7770 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7771 /* Set shell variables */
7775 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7776 /* Do we need to flag set_local_var() errors?
7777 * "assignment to readonly var" and "putenv error"
7782 /* Redirect error sets $? to 1. Otherwise,
7783 * if evaluating assignment value set $?, retain it.
7784 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7786 rcode = G.last_exitcode;
7787 /* Exit, _skipping_ variable restoring code: */
7788 goto clean_up_and_ret0;
7790 #else /* Older, bigger, but more correct code */
7792 rcode = setup_redirects(command, &squirrel);
7793 restore_redirects(squirrel);
7794 /* Set shell variables */
7796 bb_putchar_stderr('+');
7798 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7800 fprintf(stderr, " %s", p);
7801 debug_printf_exec("set shell var:'%s'->'%s'\n",
7803 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7804 /* Do we need to flag set_local_var() errors?
7805 * "assignment to readonly var" and "putenv error"
7810 bb_putchar_stderr('\n');
7811 /* Redirect error sets $? to 1. Otherwise,
7812 * if evaluating assignment value set $?, retain it.
7813 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7815 rcode = G.last_exitcode;
7816 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7818 debug_printf_exec("run_pipe: return %d\n", rcode);
7823 /* Expand the rest into (possibly) many strings each */
7825 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7826 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7830 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7833 /* if someone gives us an empty string: `cmd with empty output` */
7834 if (!argv_expanded[0]) {
7835 free(argv_expanded);
7837 return G.last_exitcode;
7840 x = find_builtin(argv_expanded[0]);
7841 #if ENABLE_HUSH_FUNCTIONS
7844 funcp = find_function(argv_expanded[0]);
7848 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7849 debug_printf("exec with redirects only\n");
7850 rcode = setup_redirects(command, NULL);
7851 /* rcode=1 can be if redir file can't be opened */
7852 goto clean_up_and_ret1;
7855 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7858 debug_printf_exec(": builtin '%s' '%s'...\n",
7859 x->b_cmd, argv_expanded[1]);
7861 rcode = x->b_function(argv_expanded) & 0xff;
7864 #if ENABLE_HUSH_FUNCTIONS
7866 # if ENABLE_HUSH_LOCAL
7867 struct variable **sv;
7868 sv = G.shadowed_vars_pp;
7869 G.shadowed_vars_pp = &old_vars;
7871 debug_printf_exec(": function '%s' '%s'...\n",
7872 funcp->name, argv_expanded[1]);
7873 rcode = run_function(funcp, argv_expanded) & 0xff;
7874 # if ENABLE_HUSH_LOCAL
7875 G.shadowed_vars_pp = sv;
7881 unset_vars(new_env);
7883 /* clean_up_and_ret0: */
7884 restore_redirects(squirrel);
7886 free(argv_expanded);
7887 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7889 debug_printf_exec("run_pipe return %d\n", rcode);
7893 if (ENABLE_FEATURE_SH_NOFORK) {
7894 int n = find_applet_by_name(argv_expanded[0]);
7895 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7896 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7898 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7899 argv_expanded[0], argv_expanded[1]);
7900 rcode = run_nofork_applet(n, argv_expanded);
7902 goto clean_up_and_ret;
7905 /* It is neither builtin nor applet. We must fork. */
7909 /* NB: argv_expanded may already be created, and that
7910 * might include `cmd` runs! Do not rerun it! We *must*
7911 * use argv_expanded if it's non-NULL */
7913 /* Going to fork a child per each pipe member */
7918 while (cmd_no < pi->num_cmds) {
7919 struct fd_pair pipefds;
7921 volatile nommu_save_t nommu_save;
7922 nommu_save.new_env = NULL;
7923 nommu_save.old_vars = NULL;
7924 nommu_save.argv = NULL;
7925 nommu_save.argv_from_re_execing = NULL;
7927 command = &pi->cmds[cmd_no];
7929 if (command->argv) {
7930 debug_printf_exec(": pipe member '%s' '%s'...\n",
7931 command->argv[0], command->argv[1]);
7933 debug_printf_exec(": pipe member with no argv\n");
7936 /* pipes are inserted between pairs of commands */
7939 if (cmd_no < pi->num_cmds)
7940 xpiped_pair(pipefds);
7942 command->pid = BB_MMU ? fork() : vfork();
7943 if (!command->pid) { /* child */
7945 disable_restore_tty_pgrp_on_exit();
7946 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7948 /* Every child adds itself to new process group
7949 * with pgid == pid_of_first_child_in_pipe */
7950 if (G.run_list_level == 1 && G_interactive_fd) {
7953 if (pgrp < 0) /* true for 1st process only */
7955 if (setpgid(0, pgrp) == 0
7956 && pi->followup != PIPE_BG
7957 && G_saved_tty_pgrp /* we have ctty */
7959 /* We do it in *every* child, not just first,
7961 tcsetpgrp(G_interactive_fd, pgrp);
7965 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7966 /* 1st cmd in backgrounded pipe
7967 * should have its stdin /dev/null'ed */
7969 if (open(bb_dev_null, O_RDONLY))
7970 xopen("/", O_RDONLY);
7972 xmove_fd(next_infd, 0);
7974 xmove_fd(pipefds.wr, 1);
7977 /* Like bash, explicit redirects override pipes,
7978 * and the pipe fd (fd#1) is available for dup'ing:
7979 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7980 * of cmd1 goes into pipe.
7982 if (setup_redirects(command, NULL)) {
7983 /* Happens when redir file can't be opened:
7984 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7986 * hush: can't open '/qwe/rty': No such file or directory
7988 * (echo BAR is not executed, it hits _exit(1) below)
7993 /* Stores to nommu_save list of env vars putenv'ed
7994 * (NOMMU, on MMU we don't need that) */
7995 /* cast away volatility... */
7996 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7997 /* pseudo_exec() does not return */
8000 /* parent or error */
8001 #if ENABLE_HUSH_FAST
8003 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8005 enable_restore_tty_pgrp_on_exit();
8007 /* Clean up after vforked child */
8008 free(nommu_save.argv);
8009 free(nommu_save.argv_from_re_execing);
8010 unset_vars(nommu_save.new_env);
8011 add_vars(nommu_save.old_vars);
8013 free(argv_expanded);
8014 argv_expanded = NULL;
8015 if (command->pid < 0) { /* [v]fork failed */
8016 /* Clearly indicate, was it fork or vfork */
8017 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8021 /* Second and next children need to know pid of first one */
8023 pi->pgrp = command->pid;
8029 if (cmd_no < pi->num_cmds)
8031 /* Pass read (output) pipe end to next iteration */
8032 next_infd = pipefds.rd;
8035 if (!pi->alive_cmds) {
8037 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8042 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8046 /* NB: called by pseudo_exec, and therefore must not modify any
8047 * global data until exec/_exit (we can be a child after vfork!) */
8048 static int run_list(struct pipe *pi)
8050 #if ENABLE_HUSH_CASE
8051 char *case_word = NULL;
8053 #if ENABLE_HUSH_LOOPS
8054 struct pipe *loop_top = NULL;
8055 char **for_lcur = NULL;
8056 char **for_list = NULL;
8058 smallint last_followup;
8060 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8061 smalluint cond_code = 0;
8063 enum { cond_code = 0 };
8066 smallint rword; /* RES_foo */
8067 smallint last_rword; /* ditto */
8070 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8073 #if ENABLE_HUSH_LOOPS
8074 /* Check syntax for "for" */
8077 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8078 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8080 /* current word is FOR or IN (BOLD in comments below) */
8081 if (cpipe->next == NULL) {
8082 syntax_error("malformed for");
8084 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8087 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8088 if (cpipe->next->res_word == RES_DO)
8090 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8091 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8092 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8094 syntax_error("malformed for");
8096 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8103 /* Past this point, all code paths should jump to ret: label
8104 * in order to return, no direct "return" statements please.
8105 * This helps to ensure that no memory is leaked. */
8113 last_rword = RES_XXXX;
8115 last_followup = PIPE_SEQ;
8116 rcode = G.last_exitcode;
8118 /* Go through list of pipes, (maybe) executing them. */
8119 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8121 int sv_errexit_depth;
8125 if (G_flag_return_in_progress == 1)
8128 IF_HAS_KEYWORDS(rword = pi->res_word;)
8129 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8130 rword, cond_code, last_rword);
8132 sv_errexit_depth = G.errexit_depth;
8133 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8134 pi->followup != PIPE_SEQ
8138 #if ENABLE_HUSH_LOOPS
8139 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8140 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8142 /* start of a loop: remember where loop starts */
8147 /* Still in the same "if...", "then..." or "do..." branch? */
8148 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8149 if ((rcode == 0 && last_followup == PIPE_OR)
8150 || (rcode != 0 && last_followup == PIPE_AND)
8152 /* It is "<true> || CMD" or "<false> && CMD"
8153 * and we should not execute CMD */
8154 debug_printf_exec("skipped cmd because of || or &&\n");
8155 last_followup = pi->followup;
8156 goto dont_check_jobs_but_continue;
8159 last_followup = pi->followup;
8160 IF_HAS_KEYWORDS(last_rword = rword;)
8163 if (rword == RES_THEN) {
8164 /* if false; then ... fi has exitcode 0! */
8165 G.last_exitcode = rcode = EXIT_SUCCESS;
8166 /* "if <false> THEN cmd": skip cmd */
8170 if (rword == RES_ELSE || rword == RES_ELIF) {
8171 /* "if <true> then ... ELSE/ELIF cmd":
8172 * skip cmd and all following ones */
8177 #if ENABLE_HUSH_LOOPS
8178 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8180 /* first loop through for */
8182 static const char encoded_dollar_at[] ALIGN1 = {
8183 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8184 }; /* encoded representation of "$@" */
8185 static const char *const encoded_dollar_at_argv[] = {
8186 encoded_dollar_at, NULL
8187 }; /* argv list with one element: "$@" */
8190 vals = (char**)encoded_dollar_at_argv;
8191 if (pi->next->res_word == RES_IN) {
8192 /* if no variable values after "in" we skip "for" */
8193 if (!pi->next->cmds[0].argv) {
8194 G.last_exitcode = rcode = EXIT_SUCCESS;
8195 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8198 vals = pi->next->cmds[0].argv;
8199 } /* else: "for var; do..." -> assume "$@" list */
8200 /* create list of variable values */
8201 debug_print_strings("for_list made from", vals);
8202 for_list = expand_strvec_to_strvec(vals);
8203 for_lcur = for_list;
8204 debug_print_strings("for_list", for_list);
8207 /* "for" loop is over, clean up */
8213 /* Insert next value from for_lcur */
8214 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8215 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8218 if (rword == RES_IN) {
8219 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8221 if (rword == RES_DONE) {
8222 continue; /* "done" has no cmds too */
8225 #if ENABLE_HUSH_CASE
8226 if (rword == RES_CASE) {
8227 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8228 case_word = expand_strvec_to_string(pi->cmds->argv);
8229 unbackslash(case_word);
8232 if (rword == RES_MATCH) {
8235 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8236 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8238 /* all prev words didn't match, does this one match? */
8239 argv = pi->cmds->argv;
8241 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8242 /* TODO: which FNM_xxx flags to use? */
8243 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8244 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8246 if (cond_code == 0) { /* match! we will execute this branch */
8248 case_word = NULL; /* make future "word)" stop */
8255 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8256 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8258 continue; /* not matched yet, skip this pipe */
8260 if (rword == RES_ESAC) {
8261 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8263 /* "case" did not match anything: still set $? (to 0) */
8264 G.last_exitcode = rcode = EXIT_SUCCESS;
8268 /* Just pressing <enter> in shell should check for jobs.
8269 * OTOH, in non-interactive shell this is useless
8270 * and only leads to extra job checks */
8271 if (pi->num_cmds == 0) {
8272 if (G_interactive_fd)
8273 goto check_jobs_and_continue;
8277 /* After analyzing all keywords and conditions, we decided
8278 * to execute this pipe. NB: have to do checkjobs(NULL)
8279 * after run_pipe to collect any background children,
8280 * even if list execution is to be stopped. */
8281 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8282 #if ENABLE_HUSH_LOOPS
8283 G.flag_break_continue = 0;
8285 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8287 /* We ran a builtin, function, or group.
8288 * rcode is already known
8289 * and we don't need to wait for anything. */
8290 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8291 G.last_exitcode = rcode;
8292 check_and_run_traps();
8293 #if ENABLE_HUSH_LOOPS
8294 /* Was it "break" or "continue"? */
8295 if (G.flag_break_continue) {
8296 smallint fbc = G.flag_break_continue;
8297 /* We might fall into outer *loop*,
8298 * don't want to break it too */
8300 G.depth_break_continue--;
8301 if (G.depth_break_continue == 0)
8302 G.flag_break_continue = 0;
8303 /* else: e.g. "continue 2" should *break* once, *then* continue */
8304 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8305 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8306 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8309 /* "continue": simulate end of loop */
8314 if (G_flag_return_in_progress == 1) {
8315 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8318 } else if (pi->followup == PIPE_BG) {
8319 /* What does bash do with attempts to background builtins? */
8320 /* even bash 3.2 doesn't do that well with nested bg:
8321 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8322 * I'm NOT treating inner &'s as jobs */
8324 if (G.run_list_level == 1)
8325 insert_job_into_table(pi);
8327 /* Last command's pid goes to $! */
8328 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8329 G.last_bg_pid_exitcode = 0;
8330 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8331 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8332 rcode = EXIT_SUCCESS;
8336 if (G.run_list_level == 1 && G_interactive_fd) {
8337 /* Waits for completion, then fg's main shell */
8338 rcode = checkjobs_and_fg_shell(pi);
8339 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8343 /* This one just waits for completion */
8344 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8345 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8347 G.last_exitcode = rcode;
8348 check_and_run_traps();
8351 /* Handle "set -e" */
8352 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8353 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8354 if (G.errexit_depth == 0)
8357 G.errexit_depth = sv_errexit_depth;
8359 /* Analyze how result affects subsequent commands */
8361 if (rword == RES_IF || rword == RES_ELIF)
8364 check_jobs_and_continue:
8365 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8366 dont_check_jobs_but_continue: ;
8367 #if ENABLE_HUSH_LOOPS
8368 /* Beware of "while false; true; do ..."! */
8370 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8371 /* check for RES_DONE is needed for "while ...; do \n done" case */
8373 if (rword == RES_WHILE) {
8375 /* "while false; do...done" - exitcode 0 */
8376 G.last_exitcode = rcode = EXIT_SUCCESS;
8377 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8381 if (rword == RES_UNTIL) {
8383 debug_printf_exec(": until expr is true: breaking\n");
8394 #if ENABLE_HUSH_LOOPS
8399 #if ENABLE_HUSH_CASE
8403 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8407 /* Select which version we will use */
8408 static int run_and_free_list(struct pipe *pi)
8411 debug_printf_exec("run_and_free_list entered\n");
8412 if (!G.o_opt[OPT_O_NOEXEC]) {
8413 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8414 rcode = run_list(pi);
8416 /* free_pipe_list has the side effect of clearing memory.
8417 * In the long run that function can be merged with run_list,
8418 * but doing that now would hobble the debugging effort. */
8420 debug_printf_exec("run_and_free_list return %d\n", rcode);
8425 static void install_sighandlers(unsigned mask)
8427 sighandler_t old_handler;
8429 while ((mask >>= 1) != 0) {
8433 old_handler = install_sighandler(sig, pick_sighandler(sig));
8434 /* POSIX allows shell to re-enable SIGCHLD
8435 * even if it was SIG_IGN on entry.
8436 * Therefore we skip IGN check for it:
8440 if (old_handler == SIG_IGN) {
8441 /* oops... restore back to IGN, and record this fact */
8442 install_sighandler(sig, old_handler);
8443 #if ENABLE_HUSH_TRAP
8445 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8447 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8453 /* Called a few times only (or even once if "sh -c") */
8454 static void install_special_sighandlers(void)
8458 /* Which signals are shell-special? */
8459 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8460 if (G_interactive_fd) {
8461 mask |= SPECIAL_INTERACTIVE_SIGS;
8462 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8463 mask |= SPECIAL_JOBSTOP_SIGS;
8465 /* Careful, do not re-install handlers we already installed */
8466 if (G.special_sig_mask != mask) {
8467 unsigned diff = mask & ~G.special_sig_mask;
8468 G.special_sig_mask = mask;
8469 install_sighandlers(diff);
8475 /* Set handlers to restore tty pgrp and exit */
8476 static void install_fatal_sighandlers(void)
8480 /* We will restore tty pgrp on these signals */
8482 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8483 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8484 + (1 << SIGBUS ) * HUSH_DEBUG
8485 + (1 << SIGSEGV) * HUSH_DEBUG
8486 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8488 /* bash 3.2 seems to handle these just like 'fatal' ones */
8491 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8492 * if we aren't interactive... but in this case
8493 * we never want to restore pgrp on exit, and this fn is not called
8495 /*+ (1 << SIGHUP )*/
8496 /*+ (1 << SIGTERM)*/
8497 /*+ (1 << SIGINT )*/
8499 G_fatal_sig_mask = mask;
8501 install_sighandlers(mask);
8505 static int set_mode(int state, char mode, const char *o_opt)
8510 G.o_opt[OPT_O_NOEXEC] = state;
8513 IF_HUSH_MODE_X(G_x_mode = state;)
8517 /* "set -+o" without parameter.
8518 * in bash, set -o produces this output:
8522 * We always use the second form.
8524 const char *p = o_opt_strings;
8527 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8533 idx = index_in_strings(o_opt_strings, o_opt);
8535 G.o_opt[idx] = state;
8539 G.o_opt[OPT_O_ERREXIT] = state;
8542 return EXIT_FAILURE;
8544 return EXIT_SUCCESS;
8547 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8548 int hush_main(int argc, char **argv)
8551 OPT_login = (1 << 0),
8555 unsigned builtin_argc;
8557 struct variable *cur_var;
8558 struct variable *shell_ver;
8561 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8562 G.last_exitcode = EXIT_SUCCESS;
8564 #if ENABLE_HUSH_FAST
8565 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8568 G.argv0_for_re_execing = argv[0];
8570 /* Deal with HUSH_VERSION */
8571 shell_ver = xzalloc(sizeof(*shell_ver));
8572 shell_ver->flg_export = 1;
8573 shell_ver->flg_read_only = 1;
8574 /* Code which handles ${var<op>...} needs writable values for all variables,
8575 * therefore we xstrdup: */
8576 shell_ver->varstr = xstrdup(hush_version_str);
8577 /* Create shell local variables from the values
8578 * currently living in the environment */
8579 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8580 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8581 G.top_var = shell_ver;
8582 cur_var = G.top_var;
8585 char *value = strchr(*e, '=');
8586 if (value) { /* paranoia */
8587 cur_var->next = xzalloc(sizeof(*cur_var));
8588 cur_var = cur_var->next;
8589 cur_var->varstr = *e;
8590 cur_var->max_len = strlen(*e);
8591 cur_var->flg_export = 1;
8595 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8596 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8597 putenv(shell_ver->varstr);
8600 set_pwd_var(/*exp:*/ 1);
8602 #if BASH_HOSTNAME_VAR
8603 /* Set (but not export) HOSTNAME unless already set */
8604 if (!get_local_var_value("HOSTNAME")) {
8607 set_local_var_from_halves("HOSTNAME", uts.nodename);
8609 /* bash also exports SHLVL and _,
8610 * and sets (but doesn't export) the following variables:
8612 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8613 * BASH_VERSION='3.2.0(1)-release'
8615 * MACHTYPE=i386-pc-linux-gnu
8617 * PPID=<NNNNN> - we also do it elsewhere
8628 * PIPESTATUS=([0]="0")
8629 * HISTFILE=/<xxx>/.bash_history
8633 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8635 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8646 #if ENABLE_FEATURE_EDITING
8647 G.line_input_state = new_line_input_t(FOR_SHELL);
8650 /* Initialize some more globals to non-zero values */
8651 cmdedit_update_prompt();
8653 die_func = restore_ttypgrp_and__exit;
8655 /* Shell is non-interactive at first. We need to call
8656 * install_special_sighandlers() if we are going to execute "sh <script>",
8657 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8658 * If we later decide that we are interactive, we run install_special_sighandlers()
8659 * in order to intercept (more) signals.
8663 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8664 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8667 opt = getopt(argc, argv, "+c:exinsl"
8670 # if ENABLE_HUSH_FUNCTIONS
8680 * sh ... -c 'script'
8681 * sh ... -c 'script' ARG0 [ARG1...]
8682 * On NOMMU, if builtin_argc != 0,
8683 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8684 * "" needs to be replaced with NULL
8685 * and BARGV vector fed to builtin function.
8686 * Note: the form without ARG0 never happens:
8687 * sh ... -c 'builtin' BARGV... ""
8690 G.root_pid = getpid();
8691 G.root_ppid = getppid();
8693 G.global_argv = argv + optind;
8694 G.global_argc = argc - optind;
8696 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8697 const struct built_in_command *x;
8699 install_special_sighandlers();
8700 x = find_builtin(optarg);
8701 if (x) { /* paranoia */
8702 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8703 G.global_argv += builtin_argc;
8704 G.global_argv[-1] = NULL; /* replace "" */
8706 G.last_exitcode = x->b_function(argv + optind - 1);
8710 if (!G.global_argv[0]) {
8711 /* -c 'script' (no params): prevent empty $0 */
8712 G.global_argv--; /* points to argv[i] of 'script' */
8713 G.global_argv[0] = argv[0];
8715 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8716 install_special_sighandlers();
8717 parse_and_run_string(optarg);
8720 /* Well, we cannot just declare interactiveness,
8721 * we have to have some stuff (ctty, etc) */
8722 /* G_interactive_fd++; */
8725 /* "-s" means "read from stdin", but this is how we always
8726 * operate, so simply do nothing here. */
8732 case '<': /* "big heredoc" support */
8733 full_write1_str(optarg);
8736 unsigned long long empty_trap_mask;
8738 G.root_pid = bb_strtou(optarg, &optarg, 16);
8740 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8742 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8744 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8746 builtin_argc = bb_strtou(optarg, &optarg, 16);
8748 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8749 if (empty_trap_mask != 0) {
8750 IF_HUSH_TRAP(int sig;)
8751 install_special_sighandlers();
8752 # if ENABLE_HUSH_TRAP
8753 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8754 for (sig = 1; sig < NSIG; sig++) {
8755 if (empty_trap_mask & (1LL << sig)) {
8756 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8757 install_sighandler(sig, SIG_IGN);
8762 # if ENABLE_HUSH_LOOPS
8764 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8770 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8772 # if ENABLE_HUSH_FUNCTIONS
8774 struct function *funcp = new_function(optarg);
8775 /* funcp->name is already set to optarg */
8776 /* funcp->body is set to NULL. It's a special case. */
8777 funcp->body_as_string = argv[optind];
8786 if (set_mode(1, opt, NULL) == 0) /* no error */
8790 fprintf(stderr, "Usage: sh [FILE]...\n"
8791 " or: sh -c command [args]...\n\n");
8797 } /* option parsing loop */
8799 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8800 G.global_argc = argc - (optind - 1);
8801 G.global_argv = argv + (optind - 1);
8802 G.global_argv[0] = argv[0];
8805 G.root_pid = getpid();
8806 G.root_ppid = getppid();
8809 /* If we are login shell... */
8810 if (flags & OPT_login) {
8812 debug_printf("sourcing /etc/profile\n");
8813 input = fopen_for_read("/etc/profile");
8814 if (input != NULL) {
8815 remember_FILE(input);
8816 install_special_sighandlers();
8817 parse_and_run_file(input);
8818 fclose_and_forget(input);
8820 /* bash: after sourcing /etc/profile,
8821 * tries to source (in the given order):
8822 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8823 * stopping on first found. --noprofile turns this off.
8824 * bash also sources ~/.bash_logout on exit.
8825 * If called as sh, skips .bash_XXX files.
8829 if (G.global_argv[1]) {
8832 * "bash <script>" (which is never interactive (unless -i?))
8833 * sources $BASH_ENV here (without scanning $PATH).
8834 * If called as sh, does the same but with $ENV.
8835 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8839 debug_printf("running script '%s'\n", G.global_argv[0]);
8840 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8841 input = xfopen_for_read(G.global_argv[0]);
8842 xfunc_error_retval = 1;
8843 remember_FILE(input);
8844 install_special_sighandlers();
8845 parse_and_run_file(input);
8846 #if ENABLE_FEATURE_CLEAN_UP
8847 fclose_and_forget(input);
8852 /* Up to here, shell was non-interactive. Now it may become one.
8853 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8856 /* A shell is interactive if the '-i' flag was given,
8857 * or if all of the following conditions are met:
8859 * no arguments remaining or the -s flag given
8860 * standard input is a terminal
8861 * standard output is a terminal
8862 * Refer to Posix.2, the description of the 'sh' utility.
8865 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8866 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8867 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8868 if (G_saved_tty_pgrp < 0)
8869 G_saved_tty_pgrp = 0;
8871 /* try to dup stdin to high fd#, >= 255 */
8872 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8873 if (G_interactive_fd < 0) {
8874 /* try to dup to any fd */
8875 G_interactive_fd = dup(STDIN_FILENO);
8876 if (G_interactive_fd < 0) {
8878 G_interactive_fd = 0;
8879 G_saved_tty_pgrp = 0;
8882 // TODO: track & disallow any attempts of user
8883 // to (inadvertently) close/redirect G_interactive_fd
8885 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8886 if (G_interactive_fd) {
8887 close_on_exec_on(G_interactive_fd);
8889 if (G_saved_tty_pgrp) {
8890 /* If we were run as 'hush &', sleep until we are
8891 * in the foreground (tty pgrp == our pgrp).
8892 * If we get started under a job aware app (like bash),
8893 * make sure we are now in charge so we don't fight over
8894 * who gets the foreground */
8896 pid_t shell_pgrp = getpgrp();
8897 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8898 if (G_saved_tty_pgrp == shell_pgrp)
8900 /* send TTIN to ourself (should stop us) */
8901 kill(- shell_pgrp, SIGTTIN);
8905 /* Install more signal handlers */
8906 install_special_sighandlers();
8908 if (G_saved_tty_pgrp) {
8909 /* Set other signals to restore saved_tty_pgrp */
8910 install_fatal_sighandlers();
8911 /* Put ourselves in our own process group
8912 * (bash, too, does this only if ctty is available) */
8913 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8914 /* Grab control of the terminal */
8915 tcsetpgrp(G_interactive_fd, getpid());
8917 enable_restore_tty_pgrp_on_exit();
8919 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8921 const char *hp = get_local_var_value("HISTFILE");
8923 hp = get_local_var_value("HOME");
8925 hp = concat_path_file(hp, ".hush_history");
8930 G.line_input_state->hist_file = hp;
8931 //set_local_var(xasprintf("HISTFILE=%s", ...));
8933 # if ENABLE_FEATURE_SH_HISTFILESIZE
8934 hp = get_local_var_value("HISTFILESIZE");
8935 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8940 install_special_sighandlers();
8942 #elif ENABLE_HUSH_INTERACTIVE
8943 /* No job control compiled in, only prompt/line editing */
8944 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8945 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8946 if (G_interactive_fd < 0) {
8947 /* try to dup to any fd */
8948 G_interactive_fd = dup(STDIN_FILENO);
8949 if (G_interactive_fd < 0)
8951 G_interactive_fd = 0;
8954 if (G_interactive_fd) {
8955 close_on_exec_on(G_interactive_fd);
8957 install_special_sighandlers();
8959 /* We have interactiveness code disabled */
8960 install_special_sighandlers();
8963 * if interactive but not a login shell, sources ~/.bashrc
8964 * (--norc turns this off, --rcfile <file> overrides)
8967 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8968 /* note: ash and hush share this string */
8969 printf("\n\n%s %s\n"
8970 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8973 "hush - the humble shell"
8977 parse_and_run_file(stdin);
8980 hush_exit(G.last_exitcode);
8987 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8992 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8993 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8995 int argc = string_array_len(argv);
8996 return applet_main_func(argc, argv);
8999 #if ENABLE_HUSH_TEST || BASH_TEST2
9000 static int FAST_FUNC builtin_test(char **argv)
9002 return run_applet_main(argv, test_main);
9005 #if ENABLE_HUSH_ECHO
9006 static int FAST_FUNC builtin_echo(char **argv)
9008 return run_applet_main(argv, echo_main);
9011 #if ENABLE_HUSH_PRINTF
9012 static int FAST_FUNC builtin_printf(char **argv)
9014 return run_applet_main(argv, printf_main);
9018 #if ENABLE_HUSH_HELP
9019 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9021 const struct built_in_command *x;
9024 "Built-in commands:\n"
9025 "------------------\n");
9026 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9028 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9030 return EXIT_SUCCESS;
9034 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9035 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9037 show_history(G.line_input_state);
9038 return EXIT_SUCCESS;
9042 static char **skip_dash_dash(char **argv)
9045 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9050 static int FAST_FUNC builtin_cd(char **argv)
9054 argv = skip_dash_dash(argv);
9056 if (newdir == NULL) {
9057 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9058 * bash says "bash: cd: HOME not set" and does nothing
9061 const char *home = get_local_var_value("HOME");
9062 newdir = home ? home : "/";
9064 if (chdir(newdir)) {
9065 /* Mimic bash message exactly */
9066 bb_perror_msg("cd: %s", newdir);
9067 return EXIT_FAILURE;
9069 /* Read current dir (get_cwd(1) is inside) and set PWD.
9070 * Note: do not enforce exporting. If PWD was unset or unexported,
9071 * set it again, but do not export. bash does the same.
9073 set_pwd_var(/*exp:*/ 0);
9074 return EXIT_SUCCESS;
9077 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9080 return EXIT_SUCCESS;
9083 static int FAST_FUNC builtin_eval(char **argv)
9085 int rcode = EXIT_SUCCESS;
9087 argv = skip_dash_dash(argv);
9089 char *str = expand_strvec_to_string(argv);
9091 * eval "echo Hi; done" ("done" is syntax error):
9092 * "echo Hi" will not execute too.
9094 parse_and_run_string(str);
9096 rcode = G.last_exitcode;
9101 static int FAST_FUNC builtin_exec(char **argv)
9103 argv = skip_dash_dash(argv);
9104 if (argv[0] == NULL)
9105 return EXIT_SUCCESS; /* bash does this */
9107 /* Careful: we can end up here after [v]fork. Do not restore
9108 * tty pgrp then, only top-level shell process does that */
9109 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9110 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9112 /* TODO: if exec fails, bash does NOT exit! We do.
9113 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9114 * and tcsetpgrp, and this is inherently racy.
9116 execvp_or_die(argv);
9119 static int FAST_FUNC builtin_exit(char **argv)
9121 debug_printf_exec("%s()\n", __func__);
9123 /* interactive bash:
9124 * # trap "echo EEE" EXIT
9127 * There are stopped jobs.
9128 * (if there are _stopped_ jobs, running ones don't count)
9131 * EEE (then bash exits)
9133 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9136 /* note: EXIT trap is run by hush_exit */
9137 argv = skip_dash_dash(argv);
9138 if (argv[0] == NULL)
9139 hush_exit(G.last_exitcode);
9140 /* mimic bash: exit 123abc == exit 255 + error msg */
9141 xfunc_error_retval = 255;
9142 /* bash: exit -2 == exit 254, no error msg */
9143 hush_exit(xatoi(argv[0]) & 0xff);
9146 #if ENABLE_HUSH_TYPE
9147 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9148 static int FAST_FUNC builtin_type(char **argv)
9150 int ret = EXIT_SUCCESS;
9156 if (0) {} /* make conditional compile easier below */
9157 /*else if (find_alias(*argv))
9158 type = "an alias";*/
9159 #if ENABLE_HUSH_FUNCTIONS
9160 else if (find_function(*argv))
9161 type = "a function";
9163 else if (find_builtin(*argv))
9164 type = "a shell builtin";
9165 else if ((path = find_in_path(*argv)) != NULL)
9168 bb_error_msg("type: %s: not found", *argv);
9173 printf("%s is %s\n", *argv, type);
9181 #if ENABLE_HUSH_READ
9182 /* Interruptibility of read builtin in bash
9183 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9185 * Empty trap makes read ignore corresponding signal, for any signal.
9188 * - terminates non-interactive shell;
9189 * - interrupts read in interactive shell;
9190 * if it has non-empty trap:
9191 * - executes trap and returns to command prompt in interactive shell;
9192 * - executes trap and returns to read in non-interactive shell;
9194 * - is ignored (does not interrupt) read in interactive shell;
9195 * - terminates non-interactive shell;
9196 * if it has non-empty trap:
9197 * - executes trap and returns to read;
9199 * - terminates shell (regardless of interactivity);
9200 * if it has non-empty trap:
9201 * - executes trap and returns to read;
9202 * SIGCHLD from children:
9203 * - does not interrupt read regardless of interactivity:
9204 * try: sleep 1 & read x; echo $x
9206 static int FAST_FUNC builtin_read(char **argv)
9216 /* "!": do not abort on errors.
9217 * Option string must start with "sr" to match BUILTIN_READ_xxx
9219 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9220 if (read_flags == (uint32_t)-1)
9221 return EXIT_FAILURE;
9223 ifs = get_local_var_value("IFS"); /* can be NULL */
9226 r = shell_builtin_read(set_local_var_from_halves,
9236 if ((uintptr_t)r == 1 && errno == EINTR) {
9237 unsigned sig = check_and_run_traps();
9242 if ((uintptr_t)r > 1) {
9243 bb_error_msg("%s", r);
9244 r = (char*)(uintptr_t)1;
9247 return (uintptr_t)r;
9251 #if ENABLE_HUSH_UMASK
9252 static int FAST_FUNC builtin_umask(char **argv)
9259 argv = skip_dash_dash(argv);
9261 mode_t old_mask = mask;
9263 /* numeric umasks are taken as-is */
9264 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9265 if (!isdigit(argv[0][0]))
9267 mask = bb_parse_mode(argv[0], mask);
9268 if (!isdigit(argv[0][0]))
9270 if ((unsigned)mask > 0777) {
9273 * bash: umask: 'q': invalid symbolic mode operator
9274 * bash: umask: 999: octal number out of range
9276 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9281 printf("%04o\n", (unsigned) mask);
9282 /* fall through and restore mask which we set to 0 */
9286 return !rc; /* rc != 0 - success */
9290 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9291 static void print_escaped(const char *s)
9296 const char *p = strchrnul(s, '\'');
9297 /* print 'xxxx', possibly just '' */
9298 printf("'%.*s'", (int)(p - s), s);
9303 /* s points to '; print "'''...'''" */
9305 do putchar('\''); while (*++s == '\'');
9311 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9312 # if !ENABLE_HUSH_LOCAL
9313 #define helper_export_local(argv, exp, lvl) \
9314 helper_export_local(argv, exp)
9316 static void helper_export_local(char **argv, int exp, int lvl)
9320 char *name_end = strchrnul(name, '=');
9322 /* So far we do not check that name is valid (TODO?) */
9324 if (*name_end == '\0') {
9325 struct variable *var, **vpp;
9327 vpp = get_ptr_to_local_var(name, name_end - name);
9328 var = vpp ? *vpp : NULL;
9330 if (exp == -1) { /* unexporting? */
9331 /* export -n NAME (without =VALUE) */
9333 var->flg_export = 0;
9334 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9336 } /* else: export -n NOT_EXISTING_VAR: no-op */
9339 if (exp == 1) { /* exporting? */
9340 /* export NAME (without =VALUE) */
9342 var->flg_export = 1;
9343 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9344 putenv(var->varstr);
9348 # if ENABLE_HUSH_LOCAL
9349 if (exp == 0 /* local? */
9350 && var && var->func_nest_level == lvl
9352 /* "local x=abc; ...; local x" - ignore second local decl */
9356 /* Exporting non-existing variable.
9357 * bash does not put it in environment,
9358 * but remembers that it is exported,
9359 * and does put it in env when it is set later.
9360 * We just set it to "" and export. */
9361 /* Or, it's "local NAME" (without =VALUE).
9362 * bash sets the value to "". */
9363 name = xasprintf("%s=", name);
9365 /* (Un)exporting/making local NAME=VALUE */
9366 name = xstrdup(name);
9368 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9373 #if ENABLE_HUSH_EXPORT
9374 static int FAST_FUNC builtin_export(char **argv)
9376 unsigned opt_unexport;
9378 #if ENABLE_HUSH_EXPORT_N
9379 /* "!": do not abort on errors */
9380 opt_unexport = getopt32(argv, "!n");
9381 if (opt_unexport == (uint32_t)-1)
9382 return EXIT_FAILURE;
9389 if (argv[0] == NULL) {
9396 /* ash emits: export VAR='VAL'
9397 * bash: declare -x VAR="VAL"
9398 * we follow ash example */
9399 const char *s = *e++;
9400 const char *p = strchr(s, '=');
9402 if (!p) /* wtf? take next variable */
9405 printf("export %.*s", (int)(p - s) + 1, s);
9406 print_escaped(p + 1);
9410 /*fflush_all(); - done after each builtin anyway */
9412 return EXIT_SUCCESS;
9415 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9417 return EXIT_SUCCESS;
9421 #if ENABLE_HUSH_LOCAL
9422 static int FAST_FUNC builtin_local(char **argv)
9424 if (G.func_nest_level == 0) {
9425 bb_error_msg("%s: not in a function", argv[0]);
9426 return EXIT_FAILURE; /* bash compat */
9428 helper_export_local(argv, 0, G.func_nest_level);
9429 return EXIT_SUCCESS;
9433 #if ENABLE_HUSH_UNSET
9434 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9435 static int FAST_FUNC builtin_unset(char **argv)
9440 /* "!": do not abort on errors */
9441 /* "+": stop at 1st non-option */
9442 opts = getopt32(argv, "!+vf");
9443 if (opts == (unsigned)-1)
9444 return EXIT_FAILURE;
9446 bb_error_msg("unset: -v and -f are exclusive");
9447 return EXIT_FAILURE;
9453 if (!(opts & 2)) { /* not -f */
9454 if (unset_local_var(*argv)) {
9455 /* unset <nonexistent_var> doesn't fail.
9456 * Error is when one tries to unset RO var.
9457 * Message was printed by unset_local_var. */
9461 # if ENABLE_HUSH_FUNCTIONS
9473 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9474 * built-in 'set' handler
9476 * set [-abCefhmnuvx] [-o option] [argument...]
9477 * set [+abCefhmnuvx] [+o option] [argument...]
9478 * set -- [argument...]
9481 * Implementations shall support the options in both their hyphen and
9482 * plus-sign forms. These options can also be specified as options to sh.
9484 * Write out all variables and their values: set
9485 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9486 * Turn on the -x and -v options: set -xv
9487 * Unset all positional parameters: set --
9488 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9489 * Set the positional parameters to the expansion of x, even if x expands
9490 * with a leading '-' or '+': set -- $x
9492 * So far, we only support "set -- [argument...]" and some of the short names.
9494 static int FAST_FUNC builtin_set(char **argv)
9497 char **pp, **g_argv;
9498 char *arg = *++argv;
9502 for (e = G.top_var; e; e = e->next)
9504 return EXIT_SUCCESS;
9508 if (strcmp(arg, "--") == 0) {
9512 if (arg[0] != '+' && arg[0] != '-')
9514 for (n = 1; arg[n]; ++n) {
9515 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9517 if (arg[n] == 'o' && argv[1])
9520 } while ((arg = *++argv) != NULL);
9521 /* Now argv[0] is 1st argument */
9524 return EXIT_SUCCESS;
9527 /* NB: G.global_argv[0] ($0) is never freed/changed */
9528 g_argv = G.global_argv;
9529 if (G.global_args_malloced) {
9535 G.global_args_malloced = 1;
9536 pp = xzalloc(sizeof(pp[0]) * 2);
9537 pp[0] = g_argv[0]; /* retain $0 */
9540 /* This realloc's G.global_argv */
9541 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9543 G.global_argc = 1 + string_array_len(pp + 1);
9545 return EXIT_SUCCESS;
9547 /* Nothing known, so abort */
9549 bb_error_msg("set: %s: invalid option", arg);
9550 return EXIT_FAILURE;
9554 static int FAST_FUNC builtin_shift(char **argv)
9557 argv = skip_dash_dash(argv);
9559 n = bb_strtou(argv[0], NULL, 10);
9560 if (errno || n < 0) {
9561 /* shared string with ash.c */
9562 bb_error_msg("Illegal number: %s", argv[0]);
9564 * ash aborts in this case.
9565 * bash prints error message and set $? to 1.
9566 * Interestingly, for "shift 99999" bash does not
9567 * print error message, but does set $? to 1
9568 * (and does no shifting at all).
9572 if (n >= 0 && n < G.global_argc) {
9573 if (G_global_args_malloced) {
9576 free(G.global_argv[m++]);
9579 memmove(&G.global_argv[1], &G.global_argv[n+1],
9580 G.global_argc * sizeof(G.global_argv[0]));
9581 return EXIT_SUCCESS;
9583 return EXIT_FAILURE;
9586 static int FAST_FUNC builtin_source(char **argv)
9588 char *arg_path, *filename;
9591 char *args_need_save;
9592 #if ENABLE_HUSH_FUNCTIONS
9596 argv = skip_dash_dash(argv);
9599 /* bash says: "bash: .: filename argument required" */
9600 return 2; /* bash compat */
9603 if (!strchr(filename, '/')) {
9604 arg_path = find_in_path(filename);
9606 filename = arg_path;
9608 input = remember_FILE(fopen_or_warn(filename, "r"));
9611 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9612 /* POSIX: non-interactive shell should abort here,
9613 * not merely fail. So far no one complained :)
9615 return EXIT_FAILURE;
9618 #if ENABLE_HUSH_FUNCTIONS
9619 sv_flg = G_flag_return_in_progress;
9620 /* "we are inside sourced file, ok to use return" */
9621 G_flag_return_in_progress = -1;
9623 args_need_save = argv[1]; /* used as a boolean variable */
9625 save_and_replace_G_args(&sv, argv);
9627 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9628 G.last_exitcode = 0;
9629 parse_and_run_file(input);
9630 fclose_and_forget(input);
9632 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9633 restore_G_args(&sv, argv);
9634 #if ENABLE_HUSH_FUNCTIONS
9635 G_flag_return_in_progress = sv_flg;
9638 return G.last_exitcode;
9641 #if ENABLE_HUSH_TRAP
9642 static int FAST_FUNC builtin_trap(char **argv)
9648 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9653 /* No args: print all trapped */
9654 for (i = 0; i < NSIG; ++i) {
9657 print_escaped(G_traps[i]);
9658 /* note: bash adds "SIG", but only if invoked
9659 * as "bash". If called as "sh", or if set -o posix,
9660 * then it prints short signal names.
9661 * We are printing short names: */
9662 printf(" %s\n", get_signame(i));
9665 /*fflush_all(); - done after each builtin anyway */
9666 return EXIT_SUCCESS;
9670 /* If first arg is a number: reset all specified signals */
9671 sig = bb_strtou(*argv, NULL, 10);
9677 sighandler_t handler;
9679 sig = get_signum(*argv++);
9680 if (sig < 0 || sig >= NSIG) {
9682 /* Mimic bash message exactly */
9683 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9688 G_traps[sig] = xstrdup(new_cmd);
9690 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9691 get_signame(sig), sig, G_traps[sig]);
9693 /* There is no signal for 0 (EXIT) */
9698 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9700 /* We are removing trap handler */
9701 handler = pick_sighandler(sig);
9702 install_sighandler(sig, handler);
9707 if (!argv[1]) { /* no second arg */
9708 bb_error_msg("trap: invalid arguments");
9709 return EXIT_FAILURE;
9712 /* First arg is "-": reset all specified to default */
9713 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9714 /* Everything else: set arg as signal handler
9715 * (includes "" case, which ignores signal) */
9716 if (argv[0][0] == '-') {
9717 if (argv[0][1] == '\0') { /* "-" */
9718 /* new_cmd remains NULL: "reset these sigs" */
9721 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9724 /* else: "-something", no special meaning */
9729 goto process_sig_list;
9734 static struct pipe *parse_jobspec(const char *str)
9739 if (sscanf(str, "%%%u", &jobnum) != 1) {
9741 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9743 bb_error_msg("bad argument '%s'", str);
9746 /* It is "%%", "%+" or "%" - current job */
9747 jobnum = G.last_jobid;
9749 bb_error_msg("no current job");
9753 for (pi = G.job_list; pi; pi = pi->next) {
9754 if (pi->jobid == jobnum) {
9758 bb_error_msg("%u: no such job", jobnum);
9762 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9765 const char *status_string;
9767 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9768 for (job = G.job_list; job; job = job->next) {
9769 if (job->alive_cmds == job->stopped_cmds)
9770 status_string = "Stopped";
9772 status_string = "Running";
9774 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9777 clean_up_last_dead_job();
9779 return EXIT_SUCCESS;
9782 /* built-in 'fg' and 'bg' handler */
9783 static int FAST_FUNC builtin_fg_bg(char **argv)
9788 if (!G_interactive_fd)
9789 return EXIT_FAILURE;
9791 /* If they gave us no args, assume they want the last backgrounded task */
9793 for (pi = G.job_list; pi; pi = pi->next) {
9794 if (pi->jobid == G.last_jobid) {
9798 bb_error_msg("%s: no current job", argv[0]);
9799 return EXIT_FAILURE;
9802 pi = parse_jobspec(argv[1]);
9804 return EXIT_FAILURE;
9806 /* TODO: bash prints a string representation
9807 * of job being foregrounded (like "sleep 1 | cat") */
9808 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9809 /* Put the job into the foreground. */
9810 tcsetpgrp(G_interactive_fd, pi->pgrp);
9813 /* Restart the processes in the job */
9814 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9815 for (i = 0; i < pi->num_cmds; i++) {
9816 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9818 pi->stopped_cmds = 0;
9820 i = kill(- pi->pgrp, SIGCONT);
9822 if (errno == ESRCH) {
9823 delete_finished_job(pi);
9824 return EXIT_SUCCESS;
9826 bb_perror_msg("kill (SIGCONT)");
9829 if (argv[0][0] == 'f') {
9830 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9831 return checkjobs_and_fg_shell(pi);
9833 return EXIT_SUCCESS;
9837 #if ENABLE_HUSH_KILL
9838 static int FAST_FUNC builtin_kill(char **argv)
9842 # if ENABLE_HUSH_JOB
9843 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9851 if (argv[i][0] != '%')
9854 * "kill %N" - job kill
9855 * Converting to pgrp / pid kill
9857 pi = parse_jobspec(argv[i]);
9859 /* Eat bad jobspec */
9863 argv[j - 1] = argv[j];
9870 * In jobs started under job control, we signal
9871 * entire process group by kill -PGRP_ID.
9872 * This happens, f.e., in interactive shell.
9874 * Otherwise, we signal each child via
9875 * kill PID1 PID2 PID3.
9877 * sh -c 'sleep 1|sleep 1 & kill %1'
9878 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9879 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9881 n = G_interactive_fd ? 1 : pi->num_cmds;
9882 dst = alloca(n * sizeof(int)*4);
9884 if (G_interactive_fd)
9885 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9886 else for (j = 0; j < n; j++) {
9887 struct command *cmd = &pi->cmds[j];
9888 /* Skip exited members of the job */
9892 * kill_main has matching code to expect
9893 * leading space. Needed to not confuse
9894 * negative pids with "kill -SIGNAL_NO" syntax
9896 dst += sprintf(dst, " %u", (int)cmd->pid);
9899 } while (argv[++i]);
9903 if (argv[1] || ret == 0) {
9904 ret = run_applet_main(argv, kill_main);
9906 /* else: ret = 1, "kill %bad_jobspec" case */
9911 #if ENABLE_HUSH_WAIT
9912 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9913 #if !ENABLE_HUSH_JOB
9914 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9916 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9923 if (!sigisemptyset(&G.pending_set))
9926 /* waitpid is not interruptible by SA_RESTARTed
9927 * signals which we use. Thus, this ugly dance:
9930 /* Make sure possible SIGCHLD is stored in kernel's
9931 * pending signal mask before we call waitpid.
9932 * Or else we may race with SIGCHLD, lose it,
9933 * and get stuck in sigsuspend...
9935 sigfillset(&oldset); /* block all signals, remember old set */
9936 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9938 if (!sigisemptyset(&G.pending_set)) {
9939 /* Crap! we raced with some signal! */
9943 /*errno = 0; - checkjobs does this */
9944 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9945 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9946 debug_printf_exec("checkjobs:%d\n", ret);
9949 int rcode = job_exited_or_stopped(waitfor_pipe);
9950 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9953 sigprocmask(SIG_SETMASK, &oldset, NULL);
9958 /* if ECHILD, there are no children (ret is -1 or 0) */
9959 /* if ret == 0, no children changed state */
9960 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9961 if (errno == ECHILD || ret) {
9963 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9965 sigprocmask(SIG_SETMASK, &oldset, NULL);
9968 /* Wait for SIGCHLD or any other signal */
9969 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9970 /* Note: sigsuspend invokes signal handler */
9971 sigsuspend(&oldset);
9973 sigprocmask(SIG_SETMASK, &oldset, NULL);
9975 /* So, did we get a signal? */
9976 sig = check_and_run_traps();
9977 if (sig /*&& sig != SIGCHLD - always true */) {
9981 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9986 static int FAST_FUNC builtin_wait(char **argv)
9991 argv = skip_dash_dash(argv);
9992 if (argv[0] == NULL) {
9993 /* Don't care about wait results */
9994 /* Note 1: must wait until there are no more children */
9995 /* Note 2: must be interruptible */
9997 * $ sleep 3 & sleep 6 & wait
10002 * $ sleep 3 & sleep 6 & wait
10003 * [1] 30936 sleep 3
10004 * [2] 30937 sleep 6
10006 * ^C <-- after ~4 sec from keyboard
10009 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10013 pid_t pid = bb_strtou(*argv, NULL, 10);
10014 if (errno || pid <= 0) {
10015 #if ENABLE_HUSH_JOB
10016 if (argv[0][0] == '%') {
10017 struct pipe *wait_pipe;
10018 ret = 127; /* bash compat for bad jobspecs */
10019 wait_pipe = parse_jobspec(*argv);
10021 ret = job_exited_or_stopped(wait_pipe);
10023 ret = wait_for_child_or_signal(wait_pipe, 0);
10025 /* waiting on "last dead job" removes it */
10026 clean_up_last_dead_job();
10029 /* else: parse_jobspec() already emitted error msg */
10033 /* mimic bash message */
10034 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10035 ret = EXIT_FAILURE;
10036 continue; /* bash checks all argv[] */
10039 /* Do we have such child? */
10040 ret = waitpid(pid, &status, WNOHANG);
10044 if (errno == ECHILD) {
10045 if (pid == G.last_bg_pid) {
10046 /* "wait $!" but last bg task has already exited. Try:
10047 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10048 * In bash it prints exitcode 0, then 3.
10049 * In dash, it is 127.
10051 ret = G.last_bg_pid_exitcode;
10053 /* Example: "wait 1". mimic bash message */
10054 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10058 bb_perror_msg("wait %s", *argv);
10060 continue; /* bash checks all argv[] */
10063 /* Yes, and it still runs */
10064 ret = wait_for_child_or_signal(NULL, pid);
10066 /* Yes, and it just exited */
10067 process_wait_result(NULL, pid, status);
10068 ret = WEXITSTATUS(status);
10069 if (WIFSIGNALED(status))
10070 ret = 128 + WTERMSIG(status);
10078 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10079 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10082 def = bb_strtou(argv[1], NULL, 10);
10083 if (errno || def < def_min || argv[2]) {
10084 bb_error_msg("%s: bad arguments", argv[0]);
10092 #if ENABLE_HUSH_LOOPS
10093 static int FAST_FUNC builtin_break(char **argv)
10096 if (G.depth_of_loop == 0) {
10097 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10098 /* if we came from builtin_continue(), need to undo "= 1" */
10099 G.flag_break_continue = 0;
10100 return EXIT_SUCCESS; /* bash compat */
10102 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10104 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10105 if (depth == UINT_MAX)
10106 G.flag_break_continue = BC_BREAK;
10107 if (G.depth_of_loop < depth)
10108 G.depth_break_continue = G.depth_of_loop;
10110 return EXIT_SUCCESS;
10113 static int FAST_FUNC builtin_continue(char **argv)
10115 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10116 return builtin_break(argv);
10120 #if ENABLE_HUSH_FUNCTIONS
10121 static int FAST_FUNC builtin_return(char **argv)
10125 if (G_flag_return_in_progress != -1) {
10126 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10127 return EXIT_FAILURE; /* bash compat */
10130 G_flag_return_in_progress = 1;
10133 * out of range: wraps around at 256, does not error out
10134 * non-numeric param:
10135 * f() { false; return qwe; }; f; echo $?
10136 * bash: return: qwe: numeric argument required <== we do this
10137 * 255 <== we also do this
10139 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10144 #if ENABLE_HUSH_MEMLEAK
10145 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10150 # ifdef M_TRIM_THRESHOLD
10151 /* Optional. Reduces probability of false positives */
10154 /* Crude attempt to find where "free memory" starts,
10155 * sans fragmentation. */
10157 l = (unsigned long)p;
10160 if (l < (unsigned long)p) l = (unsigned long)p;
10166 struct mallinfo mi = mallinfo();
10167 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10168 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10172 if (!G.memleak_value)
10173 G.memleak_value = l;
10175 l -= G.memleak_value;
10182 /* Exitcode is "how many kilobytes we leaked since 1st call" */