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, 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 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * getopts: getopt() for shells
62 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
63 * fc -l[nr] [BEG] [END]: list range of commands in history
64 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
65 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
68 * redirection of stdout+stderr: &> and >&
69 * reserved words: function select
70 * advanced test: [[ ]]
71 * process substitution: <(list) and >(list)
74 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
75 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
76 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
78 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
79 * This is exactly equivalent to let "EXPR".
80 * $[EXPR]: synonym for $((EXPR))
81 * indirect expansion: ${!VAR}
82 * substring op on @: ${@:n:m}
85 * Some builtins mandated by standards:
86 * newgrp [GRP]: not a builtin in bash but a suid binary
87 * which spawns a new shell with new group ID
88 * In bash, export builtin is special, its arguments are assignments
89 * and therefore expansion of them should be "one-word" expansion:
90 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
92 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
93 * ls: cannot access i=a: No such file or directory
94 * ls: cannot access b: No such file or directory
95 * Note1: same applies to local builtin.
96 * Note2: bash 3.2.33(1) does this only if export word itself
98 * $ export i=`echo 'aaa bbb'`; echo "$i"
100 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
104 //config: bool "hush"
107 //config: hush is a small shell (25k). It handles the normal flow control
108 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
109 //config: case/esac. Redirections, here documents, $((arithmetic))
110 //config: and functions are supported.
112 //config: It will compile and work on no-mmu systems.
114 //config: It does not handle select, aliases, tilde expansion,
115 //config: &>file and >&file redirection of stdout+stderr.
117 //config:config HUSH_BASH_COMPAT
118 //config: bool "bash-compatible extensions"
120 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
122 //config:config HUSH_BRACE_EXPANSION
123 //config: bool "Brace expansion"
125 //config: depends on HUSH_BASH_COMPAT
127 //config: Enable {abc,def} extension.
129 //config:config HUSH_INTERACTIVE
130 //config: bool "Interactive mode"
132 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
134 //config: Enable interactive mode (prompt and command editing).
135 //config: Without this, hush simply reads and executes commands
136 //config: from stdin just like a shell script from a file.
137 //config: No prompt, no PS1/PS2 magic shell variables.
139 //config:config HUSH_SAVEHISTORY
140 //config: bool "Save command history to .hush_history"
142 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
144 //config:config HUSH_JOB
145 //config: bool "Job control"
147 //config: depends on HUSH_INTERACTIVE
149 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
150 //config: command (not entire shell), fg/bg builtins work. Without this option,
151 //config: "cmd &" still works by simply spawning a process and immediately
152 //config: prompting for next command (or executing next command in a script),
153 //config: but no separate process group is formed.
155 //config:config HUSH_TICK
156 //config: bool "Support process substitution"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable `command` and $(command).
162 //config:config HUSH_IF
163 //config: bool "Support if/then/elif/else/fi"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config:config HUSH_LOOPS
168 //config: bool "Support for, while and until loops"
170 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
172 //config:config HUSH_CASE
173 //config: bool "Support case ... esac statement"
175 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
177 //config: Enable case ... esac statement. +400 bytes.
179 //config:config HUSH_FUNCTIONS
180 //config: bool "Support funcname() { commands; } syntax"
182 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
184 //config: Enable support for shell functions. +800 bytes.
186 //config:config HUSH_LOCAL
187 //config: bool "local builtin"
189 //config: depends on HUSH_FUNCTIONS
191 //config: Enable support for local variables in functions.
193 //config:config HUSH_RANDOM_SUPPORT
194 //config: bool "Pseudorandom generator and $RANDOM variable"
196 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
198 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
199 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
201 //config:config HUSH_MODE_X
202 //config: bool "Support 'hush -x' option and 'set -x' command"
204 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
206 //config: This instructs hush to print commands before execution.
207 //config: Adds ~300 bytes.
209 //config:config HUSH_ECHO
210 //config: bool "echo builtin"
212 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
214 //config:config HUSH_PRINTF
215 //config: bool "printf builtin"
217 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
219 //config:config HUSH_TEST
220 //config: bool "test builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config:config HUSH_HELP
225 //config: bool "help builtin"
227 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
229 //config:config HUSH_EXPORT
230 //config: bool "export builtin"
232 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
234 //config:config HUSH_EXPORT_N
235 //config: bool "Support 'export -n' option"
237 //config: depends on HUSH_EXPORT
239 //config: export -n unexports variables. It is a bash extension.
241 //config:config HUSH_READONLY
242 //config: bool "readonly builtin"
244 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
246 //config: Enable support for read-only variables.
248 //config:config HUSH_KILL
249 //config: bool "kill builtin (supports kill %jobspec)"
251 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
253 //config:config HUSH_WAIT
254 //config: bool "wait builtin"
256 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
258 //config:config HUSH_TRAP
259 //config: bool "trap builtin"
261 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
263 //config:config HUSH_TYPE
264 //config: bool "type builtin"
266 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
268 //config:config HUSH_READ
269 //config: bool "read builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config:config HUSH_SET
274 //config: bool "set builtin"
276 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
278 //config:config HUSH_UNSET
279 //config: bool "unset builtin"
281 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
283 //config:config HUSH_ULIMIT
284 //config: bool "ulimit builtin"
286 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
288 //config:config HUSH_UMASK
289 //config: bool "umask builtin"
291 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
293 //config:config HUSH_MEMLEAK
294 //config: bool "memleak builtin (debugging)"
296 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
298 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
299 // APPLET_ODDNAME:name main location suid_type help
300 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
301 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
303 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
304 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
305 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
306 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
308 /* -i (interactive) and -s (read stdin) are also accepted,
309 * but currently do nothing, therefore aren't shown in help.
310 * NOMMU-specific options are not meant to be used by users,
311 * therefore we don't show them either.
313 //usage:#define hush_trivial_usage
314 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
315 //usage:#define hush_full_usage "\n\n"
316 //usage: "Unix shell interpreter"
318 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
319 || defined(__APPLE__) \
321 # include <malloc.h> /* for malloc_trim */
324 /* #include <dmalloc.h> */
326 # include <fnmatch.h>
328 #include <sys/utsname.h> /* for setting $HOSTNAME */
330 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
332 #include "shell_common.h"
335 #if ENABLE_HUSH_RANDOM_SUPPORT
338 # define CLEAR_RANDOM_T(rnd) ((void)0)
340 #ifndef F_DUPFD_CLOEXEC
341 # define F_DUPFD_CLOEXEC F_DUPFD
344 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
348 /* So far, all bash compat is controlled by one config option */
349 /* Separate defines document which part of code implements what */
350 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
351 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
352 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
353 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
354 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
358 #define LEAK_HUNTING 0
359 #define BUILD_AS_NOMMU 0
360 /* Enable/disable sanity checks. Ok to enable in production,
361 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
362 * Keeping 1 for now even in released versions.
365 /* Slightly bigger (+200 bytes), but faster hush.
366 * So far it only enables a trick with counting SIGCHLDs and forks,
367 * which allows us to do fewer waitpid's.
368 * (we can detect a case where neither forks were done nor SIGCHLDs happened
369 * and therefore waitpid will return the same result as last time)
371 #define ENABLE_HUSH_FAST 0
372 /* TODO: implement simplified code for users which do not need ${var%...} ops
373 * So far ${var%...} ops are always enabled:
375 #define ENABLE_HUSH_DOLLAR_OPS 1
380 # undef USE_FOR_NOMMU
383 # define USE_FOR_NOMMU(...) __VA_ARGS__
384 # define USE_FOR_MMU(...)
387 #include "NUM_APPLETS.h"
389 /* STANDALONE does not make sense, and won't compile */
390 # undef CONFIG_FEATURE_SH_STANDALONE
391 # undef ENABLE_FEATURE_SH_STANDALONE
392 # undef IF_FEATURE_SH_STANDALONE
393 # undef IF_NOT_FEATURE_SH_STANDALONE
394 # define ENABLE_FEATURE_SH_STANDALONE 0
395 # define IF_FEATURE_SH_STANDALONE(...)
396 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
399 #if !ENABLE_HUSH_INTERACTIVE
400 # undef ENABLE_FEATURE_EDITING
401 # define ENABLE_FEATURE_EDITING 0
402 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
403 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
404 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
405 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
408 /* Do we support ANY keywords? */
409 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 # define HAS_KEYWORDS 1
411 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
412 # define IF_HAS_NO_KEYWORDS(...)
414 # define HAS_KEYWORDS 0
415 # define IF_HAS_KEYWORDS(...)
416 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
419 /* If you comment out one of these below, it will be #defined later
420 * to perform debug printfs to stderr: */
421 #define debug_printf(...) do {} while (0)
422 /* Finer-grained debug switches */
423 #define debug_printf_parse(...) do {} while (0)
424 #define debug_print_tree(a, b) do {} while (0)
425 #define debug_printf_exec(...) do {} while (0)
426 #define debug_printf_env(...) do {} while (0)
427 #define debug_printf_jobs(...) do {} while (0)
428 #define debug_printf_expand(...) do {} while (0)
429 #define debug_printf_varexp(...) do {} while (0)
430 #define debug_printf_glob(...) do {} while (0)
431 #define debug_printf_redir(...) do {} while (0)
432 #define debug_printf_list(...) do {} while (0)
433 #define debug_printf_subst(...) do {} while (0)
434 #define debug_printf_clean(...) do {} while (0)
436 #define ERR_PTR ((void*)(long)1)
438 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
440 #define _SPECIAL_VARS_STR "_*@$!?#"
441 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
442 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
443 #if BASH_PATTERN_SUBST
444 /* Support / and // replace ops */
445 /* Note that // is stored as \ in "encoded" string representation */
446 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
447 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
448 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
450 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
451 # define VAR_SUBST_OPS "%#:-=+?"
452 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
455 #define SPECIAL_VAR_SYMBOL 3
459 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
461 /* This supports saving pointers malloced in vfork child,
462 * to be freed in the parent.
465 typedef struct nommu_save_t {
467 struct variable *old_vars;
469 char **argv_from_re_execing;
482 #if ENABLE_HUSH_LOOPS
489 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
494 /* three pseudo-keywords support contrived "case" syntax: */
495 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
496 RES_MATCH , /* "word)" */
497 RES_CASE_BODY, /* "this command is inside CASE" */
504 typedef struct o_string {
506 int length; /* position where data is appended */
509 /* At least some part of the string was inside '' or "",
510 * possibly empty one: word"", wo''rd etc. */
511 smallint has_quoted_part;
512 smallint has_empty_slot;
513 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
516 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
518 /* Protect newly added chars against globbing
519 * by prepending \ to *, ?, [, \ */
520 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
523 MAYBE_ASSIGNMENT = 0,
524 DEFINITELY_ASSIGNMENT = 1,
526 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
529 /* Used for initialization: o_string foo = NULL_O_STRING; */
530 #define NULL_O_STRING { NULL }
532 #ifndef debug_printf_parse
533 static const char *const assignment_flag[] = {
535 "DEFINITELY_ASSIGNMENT",
541 typedef struct in_str {
543 #if ENABLE_HUSH_INTERACTIVE
544 smallint promptmode; /* 0: PS1, 1: PS2 */
551 /* The descrip member of this structure is only used to make
552 * debugging output pretty */
553 static const struct {
555 signed char default_fd;
558 { O_RDONLY, 0, "<" },
559 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
560 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
561 { O_CREAT|O_RDWR, 1, "<>" },
562 { O_RDONLY, 0, "<<" },
563 /* Should not be needed. Bogus default_fd helps in debugging */
564 /* { O_RDONLY, 77, "<<" }, */
567 struct redir_struct {
568 struct redir_struct *next;
569 char *rd_filename; /* filename */
570 int rd_fd; /* fd to redirect */
571 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
573 smallint rd_type; /* (enum redir_type) */
574 /* note: for heredocs, rd_filename contains heredoc delimiter,
575 * and subsequently heredoc itself; and rd_dup is a bitmask:
576 * bit 0: do we need to trim leading tabs?
577 * bit 1: is heredoc quoted (<<'delim' syntax) ?
580 typedef enum redir_type {
582 REDIRECT_OVERWRITE = 1,
585 REDIRECT_HEREDOC = 4,
586 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
589 REDIRFD_SYNTAX_ERR = -2,
590 REDIRFD_TO_FILE = -1,
591 /* otherwise, rd_fd is redirected to rd_dup */
593 HEREDOC_SKIPTABS = 1,
599 pid_t pid; /* 0 if exited */
600 int assignment_cnt; /* how many argv[i] are assignments? */
601 smallint cmd_type; /* CMD_xxx */
603 #define CMD_SUBSHELL 1
605 /* used for "[[ EXPR ]]" */
606 # define CMD_SINGLEWORD_NOGLOB 2
608 #if ENABLE_HUSH_FUNCTIONS
609 # define CMD_FUNCDEF 3
612 smalluint cmd_exitcode;
613 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
616 char *group_as_string;
618 #if ENABLE_HUSH_FUNCTIONS
619 struct function *child_func;
620 /* This field is used to prevent a bug here:
621 * while...do f1() {a;}; f1; f1() {b;}; f1; done
622 * When we execute "f1() {a;}" cmd, we create new function and clear
623 * cmd->group, cmd->group_as_string, cmd->argv[0].
624 * When we execute "f1() {b;}", we notice that f1 exists,
625 * and that its "parent cmd" struct is still "alive",
626 * we put those fields back into cmd->xxx
627 * (struct function has ->parent_cmd ptr to facilitate that).
628 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
629 * Without this trick, loop would execute a;b;b;b;...
630 * instead of correct sequence a;b;a;b;...
631 * When command is freed, it severs the link
632 * (sets ->child_func->parent_cmd to NULL).
635 char **argv; /* command name and arguments */
636 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
637 * and on execution these are substituted with their values.
638 * Substitution can make _several_ words out of one argv[n]!
639 * Example: argv[0]=='.^C*^C.' here: echo .$*.
640 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
642 struct redir_struct *redirects; /* I/O redirections */
644 /* Is there anything in this command at all? */
645 #define IS_NULL_CMD(cmd) \
646 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
650 int num_cmds; /* total number of commands in pipe */
651 int alive_cmds; /* number of commands running (not exited) */
652 int stopped_cmds; /* number of commands alive, but stopped */
654 unsigned jobid; /* job number */
655 pid_t pgrp; /* process group ID for the job */
656 char *cmdtext; /* name of job */
658 struct command *cmds; /* array of commands in pipe */
659 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
660 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
661 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
663 typedef enum pipe_style {
669 /* Is there anything in this pipe at all? */
670 #define IS_NULL_PIPE(pi) \
671 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
673 /* This holds pointers to the various results of parsing */
674 struct parse_context {
675 /* linked list of pipes */
676 struct pipe *list_head;
677 /* last pipe (being constructed right now) */
679 /* last command in pipe (being constructed right now) */
680 struct command *command;
681 /* last redirect in command->redirects list */
682 struct redir_struct *pending_redirect;
688 smallint ctx_inverted; /* "! cmd | cmd" */
690 smallint ctx_dsemicolon; /* ";;" seen */
692 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
694 /* group we are enclosed in:
695 * example: "if pipe1; pipe2; then pipe3; fi"
696 * when we see "if" or "then", we malloc and copy current context,
697 * and make ->stack point to it. then we parse pipeN.
698 * when closing "then" / fi" / whatever is found,
699 * we move list_head into ->stack->command->group,
700 * copy ->stack into current context, and delete ->stack.
701 * (parsing of { list } and ( list ) doesn't use this method)
703 struct parse_context *stack;
707 /* On program start, environ points to initial environment.
708 * putenv adds new pointers into it, unsetenv removes them.
709 * Neither of these (de)allocates the strings.
710 * setenv allocates new strings in malloc space and does putenv,
711 * and thus setenv is unusable (leaky) for shell's purposes */
712 #define setenv(...) setenv_is_leaky_dont_use()
714 struct variable *next;
715 char *varstr; /* points to "name=" portion */
716 #if ENABLE_HUSH_LOCAL
717 unsigned func_nest_level;
719 int max_len; /* if > 0, name is part of initial env; else name is malloced */
720 smallint flg_export; /* putenv should be done on this var */
721 smallint flg_read_only;
729 #if ENABLE_HUSH_FUNCTIONS
731 struct function *next;
733 struct command *parent_cmd;
736 char *body_as_string;
742 /* set -/+o OPT support. (TODO: make it optional)
743 * bash supports the following opts:
754 * interactive-comments on
772 static const char o_opt_strings[] ALIGN1 =
776 #if ENABLE_HUSH_MODE_X
784 #if ENABLE_HUSH_MODE_X
792 struct FILE_list *next;
798 /* "Globals" within this file */
799 /* Sorted roughly by size (smaller offsets == smaller code) */
801 /* interactive_fd != 0 means we are an interactive shell.
802 * If we are, then saved_tty_pgrp can also be != 0, meaning
803 * that controlling tty is available. With saved_tty_pgrp == 0,
804 * job control still works, but terminal signals
805 * (^C, ^Z, ^Y, ^\) won't work at all, and background
806 * process groups can only be created with "cmd &".
807 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
808 * to give tty to the foreground process group,
809 * and will take it back when the group is stopped (^Z)
812 #if ENABLE_HUSH_INTERACTIVE
813 /* 'interactive_fd' is a fd# open to ctty, if we have one
814 * _AND_ if we decided to act interactively */
818 # define G_interactive_fd (G.interactive_fd)
820 # define G_interactive_fd 0
822 #if ENABLE_FEATURE_EDITING
823 line_input_t *line_input_state;
828 #if ENABLE_HUSH_RANDOM_SUPPORT
834 pid_t saved_tty_pgrp;
835 struct pipe *job_list;
836 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
838 # define G_saved_tty_pgrp 0
840 /* How deeply are we in context where "set -e" is ignored */
842 /* "set -e" rules (do we follow them correctly?):
843 * Exit if pipe, list, or compound command exits with a non-zero status.
844 * Shell does not exit if failed command is part of condition in
845 * if/while, part of && or || list except the last command, any command
846 * in a pipe but the last, or if the command's return value is being
847 * inverted with !. If a compound command other than a subshell returns a
848 * non-zero status because a command failed while -e was being ignored, the
849 * shell does not exit. A trap on ERR, if set, is executed before the shell
850 * exits [ERR is a bashism].
852 * If a compound command or function executes in a context where -e is
853 * ignored, none of the commands executed within are affected by the -e
854 * setting. If a compound command or function sets -e while executing in a
855 * context where -e is ignored, that setting does not have any effect until
856 * the compound command or the command containing the function call completes.
859 char o_opt[NUM_OPT_O];
860 #if ENABLE_HUSH_MODE_X
861 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
865 smallint flag_SIGINT;
866 #if ENABLE_HUSH_LOOPS
867 smallint flag_break_continue;
869 #if ENABLE_HUSH_FUNCTIONS
870 /* 0: outside of a function (or sourced file)
871 * -1: inside of a function, ok to use return builtin
872 * 1: return is invoked, skip all till end of func
874 smallint flag_return_in_progress;
875 # define G_flag_return_in_progress (G.flag_return_in_progress)
877 # define G_flag_return_in_progress 0
879 smallint exiting; /* used to prevent EXIT trap recursion */
880 /* These four support $?, $#, and $1 */
881 smalluint last_exitcode;
882 smalluint last_bg_pid_exitcode;
884 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
885 smalluint global_args_malloced;
886 # define G_global_args_malloced (G.global_args_malloced)
888 # define G_global_args_malloced 0
890 /* how many non-NULL argv's we have. NB: $# + 1 */
894 char *argv0_for_re_execing;
896 #if ENABLE_HUSH_LOOPS
897 unsigned depth_break_continue;
898 unsigned depth_of_loop;
902 struct variable *top_var;
903 char **expanded_assignments;
904 #if ENABLE_HUSH_FUNCTIONS
905 struct function *top_func;
906 # if ENABLE_HUSH_LOCAL
907 struct variable **shadowed_vars_pp;
908 unsigned func_nest_level;
911 /* Signal and trap handling */
913 unsigned count_SIGCHLD;
914 unsigned handled_SIGCHLD;
915 smallint we_have_children;
917 struct FILE_list *FILE_list;
918 /* Which signals have non-DFL handler (even with no traps set)?
919 * Set at the start to:
920 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
921 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
922 * The rest is cleared right before execv syscalls.
923 * Other than these two times, never modified.
925 unsigned special_sig_mask;
927 unsigned fatal_sig_mask;
928 # define G_fatal_sig_mask (G.fatal_sig_mask)
930 # define G_fatal_sig_mask 0
933 char **traps; /* char *traps[NSIG] */
934 # define G_traps G.traps
936 # define G_traps ((char**)NULL)
938 sigset_t pending_set;
939 #if ENABLE_HUSH_MEMLEAK
940 unsigned long memleak_value;
946 #if ENABLE_FEATURE_EDITING
947 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
950 #define G (*ptr_to_globals)
951 /* Not #defining name to G.name - this quickly gets unwieldy
952 * (too many defines). Also, I actually prefer to see when a variable
953 * is global, thus "G." prefix is a useful hint */
954 #define INIT_G() do { \
955 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
956 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
957 sigfillset(&G.sa.sa_mask); \
958 G.sa.sa_flags = SA_RESTART; \
962 /* Function prototypes for builtins */
963 static int builtin_cd(char **argv) FAST_FUNC;
965 static int builtin_echo(char **argv) FAST_FUNC;
967 static int builtin_eval(char **argv) FAST_FUNC;
968 static int builtin_exec(char **argv) FAST_FUNC;
969 static int builtin_exit(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_EXPORT
971 static int builtin_export(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_READONLY
974 static int builtin_readonly(char **argv) FAST_FUNC;
977 static int builtin_fg_bg(char **argv) FAST_FUNC;
978 static int builtin_jobs(char **argv) FAST_FUNC;
981 static int builtin_help(char **argv) FAST_FUNC;
983 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
984 static int builtin_history(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_LOCAL
987 static int builtin_local(char **argv) FAST_FUNC;
989 #if ENABLE_HUSH_MEMLEAK
990 static int builtin_memleak(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_PRINTF
993 static int builtin_printf(char **argv) FAST_FUNC;
995 static int builtin_pwd(char **argv) FAST_FUNC;
997 static int builtin_read(char **argv) FAST_FUNC;
1000 static int builtin_set(char **argv) FAST_FUNC;
1002 static int builtin_shift(char **argv) FAST_FUNC;
1003 static int builtin_source(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_TEST || BASH_TEST2
1005 static int builtin_test(char **argv) FAST_FUNC;
1007 #if ENABLE_HUSH_TRAP
1008 static int builtin_trap(char **argv) FAST_FUNC;
1010 #if ENABLE_HUSH_TYPE
1011 static int builtin_type(char **argv) FAST_FUNC;
1013 static int builtin_true(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_UMASK
1015 static int builtin_umask(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_UNSET
1018 static int builtin_unset(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_KILL
1021 static int builtin_kill(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_WAIT
1024 static int builtin_wait(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_LOOPS
1027 static int builtin_break(char **argv) FAST_FUNC;
1028 static int builtin_continue(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_FUNCTIONS
1031 static int builtin_return(char **argv) FAST_FUNC;
1034 /* Table of built-in functions. They can be forked or not, depending on
1035 * context: within pipes, they fork. As simple commands, they do not.
1036 * When used in non-forking context, they can change global variables
1037 * in the parent shell process. If forked, of course they cannot.
1038 * For example, 'unset foo | whatever' will parse and run, but foo will
1039 * still be set at the end. */
1040 struct built_in_command {
1042 int (*b_function)(char **argv) FAST_FUNC;
1043 #if ENABLE_HUSH_HELP
1044 const char *b_descr;
1045 # define BLTIN(cmd, func, help) { cmd, func, help }
1047 # define BLTIN(cmd, func, help) { cmd, func }
1051 static const struct built_in_command bltins1[] = {
1052 BLTIN("." , builtin_source , "Run commands in file"),
1053 BLTIN(":" , builtin_true , NULL),
1055 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1057 #if ENABLE_HUSH_LOOPS
1058 BLTIN("break" , builtin_break , "Exit loop"),
1060 BLTIN("cd" , builtin_cd , "Change directory"),
1061 #if ENABLE_HUSH_LOOPS
1062 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1064 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1065 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1066 BLTIN("exit" , builtin_exit , NULL),
1067 #if ENABLE_HUSH_EXPORT
1068 BLTIN("export" , builtin_export , "Set environment variables"),
1071 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1073 #if ENABLE_HUSH_HELP
1074 BLTIN("help" , builtin_help , NULL),
1076 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1077 BLTIN("history" , builtin_history , "Show history"),
1080 BLTIN("jobs" , builtin_jobs , "List jobs"),
1082 #if ENABLE_HUSH_KILL
1083 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1085 #if ENABLE_HUSH_LOCAL
1086 BLTIN("local" , builtin_local , "Set local variables"),
1088 #if ENABLE_HUSH_MEMLEAK
1089 BLTIN("memleak" , builtin_memleak , NULL),
1091 #if ENABLE_HUSH_READ
1092 BLTIN("read" , builtin_read , "Input into variable"),
1094 #if ENABLE_HUSH_READONLY
1095 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1097 #if ENABLE_HUSH_FUNCTIONS
1098 BLTIN("return" , builtin_return , "Return from function"),
1101 BLTIN("set" , builtin_set , "Set positional parameters"),
1103 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1105 BLTIN("source" , builtin_source , NULL),
1107 #if ENABLE_HUSH_TRAP
1108 BLTIN("trap" , builtin_trap , "Trap signals"),
1110 BLTIN("true" , builtin_true , NULL),
1111 #if ENABLE_HUSH_TYPE
1112 BLTIN("type" , builtin_type , "Show command type"),
1114 #if ENABLE_HUSH_ULIMIT
1115 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1117 #if ENABLE_HUSH_UMASK
1118 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1120 #if ENABLE_HUSH_UNSET
1121 BLTIN("unset" , builtin_unset , "Unset variables"),
1123 #if ENABLE_HUSH_WAIT
1124 BLTIN("wait" , builtin_wait , "Wait for process"),
1127 /* These builtins won't be used if we are on NOMMU and need to re-exec
1128 * (it's cheaper to run an external program in this case):
1130 static const struct built_in_command bltins2[] = {
1131 #if ENABLE_HUSH_TEST
1132 BLTIN("[" , builtin_test , NULL),
1135 BLTIN("[[" , builtin_test , NULL),
1137 #if ENABLE_HUSH_ECHO
1138 BLTIN("echo" , builtin_echo , NULL),
1140 #if ENABLE_HUSH_PRINTF
1141 BLTIN("printf" , builtin_printf , NULL),
1143 BLTIN("pwd" , builtin_pwd , NULL),
1144 #if ENABLE_HUSH_TEST
1145 BLTIN("test" , builtin_test , NULL),
1153 /* prevent disasters with G.debug_indent < 0 */
1154 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1155 # define debug_enter() (G.debug_indent++)
1156 # define debug_leave() (G.debug_indent--)
1158 # define indent() ((void)0)
1159 # define debug_enter() ((void)0)
1160 # define debug_leave() ((void)0)
1163 #ifndef debug_printf
1164 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_parse
1168 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1171 #ifndef debug_printf_exec
1172 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1175 #ifndef debug_printf_env
1176 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1179 #ifndef debug_printf_jobs
1180 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1181 # define DEBUG_JOBS 1
1183 # define DEBUG_JOBS 0
1186 #ifndef debug_printf_expand
1187 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1188 # define DEBUG_EXPAND 1
1190 # define DEBUG_EXPAND 0
1193 #ifndef debug_printf_varexp
1194 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_glob
1198 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1199 # define DEBUG_GLOB 1
1201 # define DEBUG_GLOB 0
1204 #ifndef debug_printf_redir
1205 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1208 #ifndef debug_printf_list
1209 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1212 #ifndef debug_printf_subst
1213 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1216 #ifndef debug_printf_clean
1217 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1218 # define DEBUG_CLEAN 1
1220 # define DEBUG_CLEAN 0
1224 static void debug_print_strings(const char *prefix, char **vv)
1227 fdprintf(2, "%s:\n", prefix);
1229 fdprintf(2, " '%s'\n", *vv++);
1232 # define debug_print_strings(prefix, vv) ((void)0)
1236 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1239 static void *xxmalloc(int lineno, size_t size)
1241 void *ptr = xmalloc((size + 0xff) & ~0xff);
1242 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1245 static void *xxrealloc(int lineno, void *ptr, size_t size)
1247 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1248 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1251 static char *xxstrdup(int lineno, const char *str)
1253 char *ptr = xstrdup(str);
1254 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1257 static void xxfree(void *ptr)
1259 fdprintf(2, "free %p\n", ptr);
1262 # define xmalloc(s) xxmalloc(__LINE__, s)
1263 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1264 # define xstrdup(s) xxstrdup(__LINE__, s)
1265 # define free(p) xxfree(p)
1269 /* Syntax and runtime errors. They always abort scripts.
1270 * In interactive use they usually discard unparsed and/or unexecuted commands
1271 * and return to the prompt.
1272 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1275 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(unsigned lineno, const char *fmt, ...)
1288 bb_error_msg("hush.c:%u", lineno);
1291 bb_verror_msg(fmt, p, NULL);
1293 if (!G_interactive_fd)
1297 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1300 bb_error_msg("syntax error: %s", msg);
1302 bb_error_msg("syntax error");
1305 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1307 bb_error_msg("syntax error at '%s'", msg);
1310 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1312 bb_error_msg("syntax error: unterminated %s", s);
1315 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1317 char msg[2] = { ch, '\0' };
1318 syntax_error_unterm_str(lineno, msg);
1321 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1327 bb_error_msg("hush.c:%u", lineno);
1329 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1333 # undef die_if_script
1334 # undef syntax_error
1335 # undef syntax_error_at
1336 # undef syntax_error_unterm_ch
1337 # undef syntax_error_unterm_str
1338 # undef syntax_error_unexpected_ch
1340 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1341 # define syntax_error(msg) syntax_error(__LINE__, msg)
1342 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1343 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1344 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1345 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1349 #if ENABLE_HUSH_INTERACTIVE
1350 static void cmdedit_update_prompt(void);
1352 # define cmdedit_update_prompt() ((void)0)
1356 /* Utility functions
1358 /* Replace each \x with x in place, return ptr past NUL. */
1359 static char *unbackslash(char *src)
1361 char *dst = src = strchrnul(src, '\\');
1365 if ((*dst++ = *src++) == '\0')
1371 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1392 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1393 v[count1 + count2] = NULL;
1396 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1400 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1402 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1403 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1406 #define add_strings_to_strings(strings, add, need_to_dup) \
1407 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1410 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1411 static char **add_string_to_strings(char **strings, char *add)
1416 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1419 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1421 char **ptr = add_string_to_strings(strings, add);
1422 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1425 #define add_string_to_strings(strings, add) \
1426 xx_add_string_to_strings(__LINE__, strings, add)
1429 static void free_strings(char **strings)
1443 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1447 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1457 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1461 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1467 /* fd was not open? */
1477 /* Manipulating the list of open FILEs */
1478 static FILE *remember_FILE(FILE *fp)
1481 struct FILE_list *n = xmalloc(sizeof(*n));
1482 n->next = G.FILE_list;
1486 close_on_exec_on(n->fd);
1490 static void fclose_and_forget(FILE *fp)
1492 struct FILE_list **pp = &G.FILE_list;
1494 struct FILE_list *cur = *pp;
1495 if (cur->fp == fp) {
1504 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1506 struct FILE_list *fl = G.FILE_list;
1509 /* We use it only on script files, they are all CLOEXEC */
1510 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1511 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1518 static void restore_redirected_FILEs(void)
1520 struct FILE_list *fl = G.FILE_list;
1522 int should_be = fileno(fl->fp);
1523 if (fl->fd != should_be) {
1524 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1525 xmove_fd(fl->fd, should_be);
1531 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1532 static void close_all_FILE_list(void)
1534 struct FILE_list *fl = G.FILE_list;
1536 /* fclose would also free FILE object.
1537 * It is disastrous if we share memory with a vforked parent.
1538 * I'm not sure we never come here after vfork.
1539 * Therefore just close fd, nothing more.
1541 /*fclose(fl->fp); - unsafe */
1549 /* Helpers for setting new $n and restoring them back
1551 typedef struct save_arg_t {
1555 IF_HUSH_SET(smallint sv_g_malloced;)
1558 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1560 sv->sv_argv0 = argv[0];
1561 sv->sv_g_argv = G.global_argv;
1562 sv->sv_g_argc = G.global_argc;
1563 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1565 argv[0] = G.global_argv[0]; /* retain $0 */
1566 G.global_argv = argv;
1567 IF_HUSH_SET(G.global_args_malloced = 0;)
1569 G.global_argc = 1 + string_array_len(argv + 1);
1572 static void restore_G_args(save_arg_t *sv, char **argv)
1575 if (G.global_args_malloced) {
1576 /* someone ran "set -- arg1 arg2 ...", undo */
1577 char **pp = G.global_argv;
1578 while (*++pp) /* note: does not free $0 */
1580 free(G.global_argv);
1583 argv[0] = sv->sv_argv0;
1584 G.global_argv = sv->sv_g_argv;
1585 G.global_argc = sv->sv_g_argc;
1586 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1590 /* Basic theory of signal handling in shell
1591 * ========================================
1592 * This does not describe what hush does, rather, it is current understanding
1593 * what it _should_ do. If it doesn't, it's a bug.
1594 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1596 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1597 * is finished or backgrounded. It is the same in interactive and
1598 * non-interactive shells, and is the same regardless of whether
1599 * a user trap handler is installed or a shell special one is in effect.
1600 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1601 * backgrounds (i.e. stops) or kills all members of currently running
1604 * Wait builtin is interruptible by signals for which user trap is set
1605 * or by SIGINT in interactive shell.
1607 * Trap handlers will execute even within trap handlers. (right?)
1609 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1610 * except for handlers set to '' (empty string).
1612 * If job control is off, backgrounded commands ("cmd &")
1613 * have SIGINT, SIGQUIT set to SIG_IGN.
1615 * Commands which are run in command substitution ("`cmd`")
1616 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1618 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1619 * by the shell from its parent.
1621 * Signals which differ from SIG_DFL action
1622 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1625 * SIGTERM (interactive): ignore
1626 * SIGHUP (interactive):
1627 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1628 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1629 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1630 * that all pipe members are stopped. Try this in bash:
1631 * while :; do :; done - ^Z does not background it
1632 * (while :; do :; done) - ^Z backgrounds it
1633 * SIGINT (interactive): wait for last pipe, ignore the rest
1634 * of the command line, show prompt. NB: ^C does not send SIGINT
1635 * to interactive shell while shell is waiting for a pipe,
1636 * since shell is bg'ed (is not in foreground process group).
1637 * Example 1: this waits 5 sec, but does not execute ls:
1638 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1639 * Example 2: this does not wait and does not execute ls:
1640 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1641 * Example 3: this does not wait 5 sec, but executes ls:
1642 * "sleep 5; ls -l" + press ^C
1643 * Example 4: this does not wait and does not execute ls:
1644 * "sleep 5 & wait; ls -l" + press ^C
1646 * (What happens to signals which are IGN on shell start?)
1647 * (What happens with signal mask on shell start?)
1649 * Old implementation
1650 * ==================
1651 * We use in-kernel pending signal mask to determine which signals were sent.
1652 * We block all signals which we don't want to take action immediately,
1653 * i.e. we block all signals which need to have special handling as described
1654 * above, and all signals which have traps set.
1655 * After each pipe execution, we extract any pending signals via sigtimedwait()
1658 * unsigned special_sig_mask: a mask of such "special" signals
1659 * sigset_t blocked_set: current blocked signal set
1662 * clear bit in blocked_set unless it is also in special_sig_mask
1663 * "trap 'cmd' SIGxxx":
1664 * set bit in blocked_set (even if 'cmd' is '')
1665 * after [v]fork, if we plan to be a shell:
1666 * unblock signals with special interactive handling
1667 * (child shell is not interactive),
1668 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1669 * after [v]fork, if we plan to exec:
1670 * POSIX says fork clears pending signal mask in child - no need to clear it.
1671 * Restore blocked signal set to one inherited by shell just prior to exec.
1673 * Note: as a result, we do not use signal handlers much. The only uses
1674 * are to count SIGCHLDs
1675 * and to restore tty pgrp on signal-induced exit.
1678 * Standard says "When a subshell is entered, traps that are not being ignored
1679 * are set to the default actions". bash interprets it so that traps which
1680 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1682 * Problem: the above approach makes it unwieldy to catch signals while
1683 * we are in read builtin, or while we read commands from stdin:
1684 * masked signals are not visible!
1686 * New implementation
1687 * ==================
1688 * We record each signal we are interested in by installing signal handler
1689 * for them - a bit like emulating kernel pending signal mask in userspace.
1690 * We are interested in: signals which need to have special handling
1691 * as described above, and all signals which have traps set.
1692 * Signals are recorded in pending_set.
1693 * After each pipe execution, we extract any pending signals
1696 * unsigned special_sig_mask: a mask of shell-special signals.
1697 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1698 * char *traps[sig] if trap for sig is set (even if it's '').
1699 * sigset_t pending_set: set of sigs we received.
1702 * if sig is in special_sig_mask, set handler back to:
1703 * record_pending_signo, or to IGN if it's a tty stop signal
1704 * if sig is in fatal_sig_mask, set handler back to sigexit.
1705 * else: set handler back to SIG_DFL
1706 * "trap 'cmd' SIGxxx":
1707 * set handler to record_pending_signo.
1709 * set handler to SIG_IGN.
1710 * after [v]fork, if we plan to be a shell:
1711 * set signals with special interactive handling to SIG_DFL
1712 * (because child shell is not interactive),
1713 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1714 * after [v]fork, if we plan to exec:
1715 * POSIX says fork clears pending signal mask in child - no need to clear it.
1717 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1718 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1721 * Standard says "When a subshell is entered, traps that are not being ignored
1722 * are set to the default actions". bash interprets it so that traps which
1723 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1726 SPECIAL_INTERACTIVE_SIGS = 0
1731 SPECIAL_JOBSTOP_SIGS = 0
1740 static void record_pending_signo(int sig)
1742 sigaddset(&G.pending_set, sig);
1743 #if ENABLE_HUSH_FAST
1744 if (sig == SIGCHLD) {
1746 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1751 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1753 struct sigaction old_sa;
1755 /* We could use signal() to install handlers... almost:
1756 * except that we need to mask ALL signals while handlers run.
1757 * I saw signal nesting in strace, race window isn't small.
1758 * SA_RESTART is also needed, but in Linux, signal()
1759 * sets SA_RESTART too.
1761 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1762 /* sigfillset(&G.sa.sa_mask); - already done */
1763 /* G.sa.sa_flags = SA_RESTART; - already done */
1764 G.sa.sa_handler = handler;
1765 sigaction(sig, &G.sa, &old_sa);
1766 return old_sa.sa_handler;
1769 static void hush_exit(int exitcode) NORETURN;
1771 static void restore_ttypgrp_and__exit(void) NORETURN;
1772 static void restore_ttypgrp_and__exit(void)
1774 /* xfunc has failed! die die die */
1775 /* no EXIT traps, this is an escape hatch! */
1777 hush_exit(xfunc_error_retval);
1782 /* Needed only on some libc:
1783 * It was observed that on exit(), fgetc'ed buffered data
1784 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1785 * With the net effect that even after fork(), not vfork(),
1786 * exit() in NOEXECed applet in "sh SCRIPT":
1787 * noexec_applet_here
1788 * echo END_OF_SCRIPT
1789 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1790 * This makes "echo END_OF_SCRIPT" executed twice.
1791 * Similar problems can be seen with die_if_script() -> xfunc_die()
1792 * and in `cmd` handling.
1793 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1795 static void fflush_and__exit(void) NORETURN;
1796 static void fflush_and__exit(void)
1799 _exit(xfunc_error_retval);
1802 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1803 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1804 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1805 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1807 /* Restores tty foreground process group, and exits.
1808 * May be called as signal handler for fatal signal
1809 * (will resend signal to itself, producing correct exit state)
1810 * or called directly with -EXITCODE.
1811 * We also call it if xfunc is exiting.
1813 static void sigexit(int sig) NORETURN;
1814 static void sigexit(int sig)
1816 /* Careful: we can end up here after [v]fork. Do not restore
1817 * tty pgrp then, only top-level shell process does that */
1818 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1819 /* Disable all signals: job control, SIGPIPE, etc.
1820 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1822 sigprocmask_allsigs(SIG_BLOCK);
1823 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1826 /* Not a signal, just exit */
1830 kill_myself_with_sig(sig); /* does not return */
1834 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1835 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1839 static sighandler_t pick_sighandler(unsigned sig)
1841 sighandler_t handler = SIG_DFL;
1842 if (sig < sizeof(unsigned)*8) {
1843 unsigned sigmask = (1 << sig);
1847 if (G_fatal_sig_mask & sigmask)
1851 /* sig has special handling? */
1852 if (G.special_sig_mask & sigmask) {
1853 handler = record_pending_signo;
1854 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1855 * in order to ignore them: they will be raised
1856 * in an endless loop when we try to do some
1857 * terminal ioctls! We do have to _ignore_ these.
1859 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1866 /* Restores tty foreground process group, and exits. */
1867 static void hush_exit(int exitcode)
1869 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1870 save_history(G.line_input_state);
1874 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1876 /* argv[0] is unused */
1877 argv[1] = G_traps[0];
1879 G.exiting = 1; /* prevent EXIT trap recursion */
1880 /* Note: G_traps[0] is not cleared!
1881 * "trap" will still show it, if executed
1886 #if ENABLE_FEATURE_CLEAN_UP
1888 struct variable *cur_var;
1889 if (G.cwd != bb_msg_unknown)
1891 cur_var = G.top_var;
1893 struct variable *tmp = cur_var;
1894 if (!cur_var->max_len)
1895 free(cur_var->varstr);
1896 cur_var = cur_var->next;
1904 sigexit(- (exitcode & 0xff));
1911 //TODO: return a mask of ALL handled sigs?
1912 static int check_and_run_traps(void)
1919 if (sigisemptyset(&G.pending_set))
1924 if (sigismember(&G.pending_set, sig)) {
1925 sigdelset(&G.pending_set, sig);
1928 } while (sig < NSIG);
1931 if (G_traps && G_traps[sig]) {
1932 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1933 if (G_traps[sig][0]) {
1934 /* We have user-defined handler */
1935 smalluint save_rcode;
1937 /* argv[0] is unused */
1938 argv[1] = G_traps[sig];
1940 save_rcode = G.last_exitcode;
1942 //FIXME: shouldn't it be set to 128 + sig instead?
1943 G.last_exitcode = save_rcode;
1945 } /* else: "" trap, ignoring signal */
1948 /* not a trap: special action */
1951 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1958 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1959 /* bash is observed to signal whole process groups,
1960 * not individual processes */
1961 for (job = G.job_list; job; job = job->next) {
1964 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1965 if (kill(- job->pgrp, SIGHUP) == 0)
1966 kill(- job->pgrp, SIGCONT);
1971 #if ENABLE_HUSH_FAST
1973 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1975 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1977 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1978 * This simplifies wait builtin a bit.
1982 default: /* ignored: */
1983 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1984 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1986 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1987 * Example: wait is not interrupted by TERM
1988 * in interactive shell, because TERM is ignored.
1997 static const char *get_cwd(int force)
1999 if (force || G.cwd == NULL) {
2000 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2001 * we must not try to free(bb_msg_unknown) */
2002 if (G.cwd == bb_msg_unknown)
2004 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2006 G.cwd = bb_msg_unknown;
2013 * Shell and environment variable support
2015 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2017 struct variable **pp;
2018 struct variable *cur;
2021 while ((cur = *pp) != NULL) {
2022 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2029 static const char* FAST_FUNC get_local_var_value(const char *name)
2031 struct variable **vpp;
2032 unsigned len = strlen(name);
2034 if (G.expanded_assignments) {
2035 char **cpp = G.expanded_assignments;
2038 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2039 return cp + len + 1;
2044 vpp = get_ptr_to_local_var(name, len);
2046 return (*vpp)->varstr + len + 1;
2048 if (strcmp(name, "PPID") == 0)
2049 return utoa(G.root_ppid);
2050 // bash compat: UID? EUID?
2051 #if ENABLE_HUSH_RANDOM_SUPPORT
2052 if (strcmp(name, "RANDOM") == 0)
2053 return utoa(next_random(&G.random_gen));
2058 /* str holds "NAME=VAL" and is expected to be malloced.
2059 * We take ownership of it.
2061 #define SETFLAG_EXPORT (1 << 0)
2062 #define SETFLAG_UNEXPORT (1 << 1)
2063 #define SETFLAG_MAKE_RO (1 << 2)
2064 #define SETFLAG_LOCAL_SHIFT 3
2065 static int set_local_var(char *str, unsigned flags)
2067 struct variable **var_pp;
2068 struct variable *cur;
2069 char *free_me = NULL;
2072 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2074 eq_sign = strchr(str, '=');
2075 if (!eq_sign) { /* not expected to ever happen? */
2080 name_len = eq_sign - str + 1; /* including '=' */
2081 var_pp = &G.top_var;
2082 while ((cur = *var_pp) != NULL) {
2083 if (strncmp(cur->varstr, str, name_len) != 0) {
2084 var_pp = &cur->next;
2088 /* We found an existing var with this name */
2089 if (cur->flg_read_only) {
2090 bb_error_msg("%s: readonly variable", str);
2094 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2095 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2100 #if ENABLE_HUSH_LOCAL
2101 if (cur->func_nest_level < local_lvl) {
2102 /* New variable is declared as local,
2103 * and existing one is global, or local
2104 * from enclosing function.
2105 * Remove and save old one: */
2106 *var_pp = cur->next;
2107 cur->next = *G.shadowed_vars_pp;
2108 *G.shadowed_vars_pp = cur;
2109 /* bash 3.2.33(1) and exported vars:
2111 * # f() { local z=a; env | grep ^z; }
2117 if (cur->flg_export)
2118 flags |= SETFLAG_EXPORT;
2122 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2127 if (cur->max_len != 0) {
2128 if (cur->max_len >= strlen(str)) {
2129 /* This one is from startup env, reuse space */
2130 strcpy(cur->varstr, str);
2135 goto set_str_and_exp;
2137 /* max_len == 0 signifies "malloced" var, which we can
2138 * (and have to) free. But we can't free(cur->varstr) here:
2139 * if cur->flg_export is 1, it is in the environment.
2140 * We should either unsetenv+free, or wait until putenv,
2141 * then putenv(new)+free(old).
2143 free_me = cur->varstr;
2144 goto set_str_and_exp;
2147 /* Not found - create new variable struct */
2148 cur = xzalloc(sizeof(*cur));
2149 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2150 cur->next = *var_pp;
2156 #if !BB_MMU || ENABLE_HUSH_READONLY
2157 if (flags & SETFLAG_MAKE_RO) {
2158 cur->flg_read_only = 1;
2161 if (flags & SETFLAG_EXPORT)
2162 cur->flg_export = 1;
2163 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2164 cmdedit_update_prompt();
2165 if (cur->flg_export) {
2166 if (flags & SETFLAG_UNEXPORT) {
2167 cur->flg_export = 0;
2168 /* unsetenv was already done */
2171 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2172 i = putenv(cur->varstr);
2173 /* only now we can free old exported malloced string */
2182 /* Used at startup and after each cd */
2183 static void set_pwd_var(unsigned flag)
2185 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2188 static int unset_local_var_len(const char *name, int name_len)
2190 struct variable *cur;
2191 struct variable **var_pp;
2194 return EXIT_SUCCESS;
2195 var_pp = &G.top_var;
2196 while ((cur = *var_pp) != NULL) {
2197 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2198 if (cur->flg_read_only) {
2199 bb_error_msg("%s: readonly variable", name);
2200 return EXIT_FAILURE;
2202 *var_pp = cur->next;
2203 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2204 bb_unsetenv(cur->varstr);
2205 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2206 cmdedit_update_prompt();
2210 return EXIT_SUCCESS;
2212 var_pp = &cur->next;
2214 return EXIT_SUCCESS;
2217 #if ENABLE_HUSH_UNSET
2218 static int unset_local_var(const char *name)
2220 return unset_local_var_len(name, strlen(name));
2224 static void unset_vars(char **strings)
2232 const char *eq = strchrnul(*v, '=');
2233 unset_local_var_len(*v, (int)(eq - *v));
2239 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2240 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2242 char *var = xasprintf("%s=%s", name, val);
2243 set_local_var(var, /*flag:*/ 0);
2249 * Helpers for "var1=val1 var2=val2 cmd" feature
2251 static void add_vars(struct variable *var)
2253 struct variable *next;
2257 var->next = G.top_var;
2259 if (var->flg_export) {
2260 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2261 putenv(var->varstr);
2263 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2269 static struct variable *set_vars_and_save_old(char **strings)
2272 struct variable *old = NULL;
2278 struct variable *var_p;
2279 struct variable **var_pp;
2282 eq = strchr(*s, '=');
2284 var_pp = get_ptr_to_local_var(*s, eq - *s);
2286 /* Remove variable from global linked list */
2288 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2289 *var_pp = var_p->next;
2290 /* Add it to returned list */
2294 set_local_var(*s, SETFLAG_EXPORT);
2305 static void reinit_unicode_for_hush(void)
2307 /* Unicode support should be activated even if LANG is set
2308 * _during_ shell execution, not only if it was set when
2309 * shell was started. Therefore, re-check LANG every time:
2311 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2312 || ENABLE_UNICODE_USING_LOCALE
2314 const char *s = get_local_var_value("LC_ALL");
2315 if (!s) s = get_local_var_value("LC_CTYPE");
2316 if (!s) s = get_local_var_value("LANG");
2322 * in_str support (strings, and "strings" read from files).
2325 #if ENABLE_HUSH_INTERACTIVE
2326 /* To test correct lineedit/interactive behavior, type from command line:
2332 * It exercises a lot of corner cases.
2334 static void cmdedit_update_prompt(void)
2336 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2337 G.PS1 = get_local_var_value("PS1");
2340 G.PS2 = get_local_var_value("PS2");
2347 static const char *setup_prompt_string(int promptmode)
2349 const char *prompt_str;
2350 debug_printf("setup_prompt_string %d ", promptmode);
2351 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2352 /* Set up the prompt */
2353 if (promptmode == 0) { /* PS1 */
2355 /* bash uses $PWD value, even if it is set by user.
2356 * It uses current dir only if PWD is unset.
2357 * We always use current dir. */
2358 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2363 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2364 debug_printf("prompt_str '%s'\n", prompt_str);
2367 static int get_user_input(struct in_str *i)
2370 const char *prompt_str;
2372 prompt_str = setup_prompt_string(i->promptmode);
2373 # if ENABLE_FEATURE_EDITING
2375 reinit_unicode_for_hush();
2376 if (G.flag_SIGINT) {
2377 /* There was ^C'ed, make it look prettier: */
2381 /* buglet: SIGINT will not make new prompt to appear _at once_,
2382 * only after <Enter>. (^C works immediately) */
2383 r = read_line_input(G.line_input_state, prompt_str,
2384 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2387 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2389 write(STDOUT_FILENO, "^C", 2);
2392 check_and_run_traps();
2393 if (r != 0 && !G.flag_SIGINT)
2395 /* ^C or SIGINT: repeat */
2396 G.last_exitcode = 128 + SIGINT;
2399 /* EOF/error detected */
2401 i->peek_buf[0] = r = EOF;
2404 i->p = G.user_input_buf;
2405 return (unsigned char)*i->p++;
2409 if (i->last_char == '\0' || i->last_char == '\n') {
2410 /* Why check_and_run_traps here? Try this interactively:
2411 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2412 * $ <[enter], repeatedly...>
2413 * Without check_and_run_traps, handler never runs.
2415 check_and_run_traps();
2416 fputs(prompt_str, stdout);
2419 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2421 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2422 * no ^C masking happens during fgetc, no special code for ^C:
2423 * it generates SIGINT as usual.
2425 check_and_run_traps();
2427 G.last_exitcode = 128 + SIGINT;
2434 /* This is the magic location that prints prompts
2435 * and gets data back from the user */
2436 static int fgetc_interactive(struct in_str *i)
2439 /* If it's interactive stdin, get new line. */
2440 if (G_interactive_fd && i->file == stdin) {
2441 /* Returns first char (or EOF), the rest is in i->p[] */
2442 ch = get_user_input(i);
2443 i->promptmode = 1; /* PS2 */
2445 /* Not stdin: script file, sourced file, etc */
2446 do ch = fgetc(i->file); while (ch == '\0');
2451 static inline int fgetc_interactive(struct in_str *i)
2454 do ch = fgetc(i->file); while (ch == '\0');
2457 #endif /* INTERACTIVE */
2459 static int i_getch(struct in_str *i)
2464 /* string-based in_str */
2465 ch = (unsigned char)*i->p;
2474 /* FILE-based in_str */
2476 #if ENABLE_FEATURE_EDITING
2477 /* This can be stdin, check line editing char[] buffer */
2478 if (i->p && *i->p != '\0') {
2479 ch = (unsigned char)*i->p++;
2483 /* peek_buf[] is an int array, not char. Can contain EOF. */
2484 ch = i->peek_buf[0];
2486 int ch2 = i->peek_buf[1];
2487 i->peek_buf[0] = ch2;
2488 if (ch2 == 0) /* very likely, avoid redundant write */
2494 ch = fgetc_interactive(i);
2496 debug_printf("file_get: got '%c' %d\n", ch, ch);
2501 static int i_peek(struct in_str *i)
2506 /* string-based in_str */
2507 /* Doesn't report EOF on NUL. None of the callers care. */
2508 return (unsigned char)*i->p;
2511 /* FILE-based in_str */
2513 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2514 /* This can be stdin, check line editing char[] buffer */
2515 if (i->p && *i->p != '\0')
2516 return (unsigned char)*i->p;
2518 /* peek_buf[] is an int array, not char. Can contain EOF. */
2519 ch = i->peek_buf[0];
2523 /* Need to get a new char */
2524 ch = fgetc_interactive(i);
2525 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2527 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2528 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2534 i->peek_buf[0] = ch;
2535 /*i->peek_buf[1] = 0; - already is */
2539 /* Only ever called if i_peek() was called, and did not return EOF.
2540 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2541 * not end-of-line. Therefore we never need to read a new editing line here.
2543 static int i_peek2(struct in_str *i)
2547 /* There are two cases when i->p[] buffer exists.
2548 * (1) it's a string in_str.
2549 * (2) It's a file, and we have a saved line editing buffer.
2550 * In both cases, we know that i->p[0] exists and not NUL, and
2551 * the peek2 result is in i->p[1].
2554 return (unsigned char)i->p[1];
2556 /* Now we know it is a file-based in_str. */
2558 /* peek_buf[] is an int array, not char. Can contain EOF. */
2559 /* Is there 2nd char? */
2560 ch = i->peek_buf[1];
2562 /* We did not read it yet, get it now */
2563 do ch = fgetc(i->file); while (ch == '\0');
2564 i->peek_buf[1] = ch;
2567 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2571 static void setup_file_in_str(struct in_str *i, FILE *f)
2573 memset(i, 0, sizeof(*i));
2574 /* i->promptmode = 0; - PS1 (memset did it) */
2579 static void setup_string_in_str(struct in_str *i, const char *s)
2581 memset(i, 0, sizeof(*i));
2582 /* i->promptmode = 0; - PS1 (memset did it) */
2583 /*i->file = NULL */;
2591 #define B_CHUNK (32 * sizeof(char*))
2593 static void o_reset_to_empty_unquoted(o_string *o)
2596 o->has_quoted_part = 0;
2601 static void o_free(o_string *o)
2604 memset(o, 0, sizeof(*o));
2607 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2612 static void o_grow_by(o_string *o, int len)
2614 if (o->length + len > o->maxlen) {
2615 o->maxlen += (2 * len) | (B_CHUNK-1);
2616 o->data = xrealloc(o->data, 1 + o->maxlen);
2620 static void o_addchr(o_string *o, int ch)
2622 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2623 if (o->length < o->maxlen) {
2624 /* likely. avoid o_grow_by() call */
2626 o->data[o->length] = ch;
2628 o->data[o->length] = '\0';
2636 /* Valid only if we know o_string is not empty */
2637 static void o_delchr(o_string *o)
2640 o->data[o->length] = '\0';
2644 static void o_addblock(o_string *o, const char *str, int len)
2647 memcpy(&o->data[o->length], str, len);
2649 o->data[o->length] = '\0';
2652 static void o_addstr(o_string *o, const char *str)
2654 o_addblock(o, str, strlen(str));
2658 static void nommu_addchr(o_string *o, int ch)
2664 # define nommu_addchr(o, str) ((void)0)
2667 static void o_addstr_with_NUL(o_string *o, const char *str)
2669 o_addblock(o, str, strlen(str) + 1);
2673 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2674 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2675 * Apparently, on unquoted $v bash still does globbing
2676 * ("v='*.txt'; echo $v" prints all .txt files),
2677 * but NOT brace expansion! Thus, there should be TWO independent
2678 * quoting mechanisms on $v expansion side: one protects
2679 * $v from brace expansion, and other additionally protects "$v" against globbing.
2680 * We have only second one.
2683 #if ENABLE_HUSH_BRACE_EXPANSION
2684 # define MAYBE_BRACES "{}"
2686 # define MAYBE_BRACES ""
2689 /* My analysis of quoting semantics tells me that state information
2690 * is associated with a destination, not a source.
2692 static void o_addqchr(o_string *o, int ch)
2695 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2700 o->data[o->length] = '\\';
2703 o->data[o->length] = ch;
2705 o->data[o->length] = '\0';
2708 static void o_addQchr(o_string *o, int ch)
2711 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2712 && strchr("*?[\\" MAYBE_BRACES, ch)
2715 o->data[o->length] = '\\';
2719 o->data[o->length] = ch;
2721 o->data[o->length] = '\0';
2724 static void o_addqblock(o_string *o, const char *str, int len)
2729 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2730 if (ordinary_cnt > len) /* paranoia */
2732 o_addblock(o, str, ordinary_cnt);
2733 if (ordinary_cnt == len)
2734 return; /* NUL is already added by o_addblock */
2735 str += ordinary_cnt;
2736 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2740 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2742 o->data[o->length] = '\\';
2746 o->data[o->length] = ch;
2749 o->data[o->length] = '\0';
2752 static void o_addQblock(o_string *o, const char *str, int len)
2754 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2755 o_addblock(o, str, len);
2758 o_addqblock(o, str, len);
2761 static void o_addQstr(o_string *o, const char *str)
2763 o_addQblock(o, str, strlen(str));
2766 /* A special kind of o_string for $VAR and `cmd` expansion.
2767 * It contains char* list[] at the beginning, which is grown in 16 element
2768 * increments. Actual string data starts at the next multiple of 16 * (char*).
2769 * list[i] contains an INDEX (int!) into this string data.
2770 * It means that if list[] needs to grow, data needs to be moved higher up
2771 * but list[i]'s need not be modified.
2772 * NB: remembering how many list[i]'s you have there is crucial.
2773 * o_finalize_list() operation post-processes this structure - calculates
2774 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2776 #if DEBUG_EXPAND || DEBUG_GLOB
2777 static void debug_print_list(const char *prefix, o_string *o, int n)
2779 char **list = (char**)o->data;
2780 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2784 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2785 prefix, list, n, string_start, o->length, o->maxlen,
2786 !!(o->o_expflags & EXP_FLAG_GLOB),
2788 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2791 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2792 o->data + (int)(uintptr_t)list[i] + string_start,
2793 o->data + (int)(uintptr_t)list[i] + string_start);
2797 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2799 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2803 # define debug_print_list(prefix, o, n) ((void)0)
2806 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2807 * in list[n] so that it points past last stored byte so far.
2808 * It returns n+1. */
2809 static int o_save_ptr_helper(o_string *o, int n)
2811 char **list = (char**)o->data;
2815 if (!o->has_empty_slot) {
2816 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2817 string_len = o->length - string_start;
2818 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2819 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2820 /* list[n] points to string_start, make space for 16 more pointers */
2821 o->maxlen += 0x10 * sizeof(list[0]);
2822 o->data = xrealloc(o->data, o->maxlen + 1);
2823 list = (char**)o->data;
2824 memmove(list + n + 0x10, list + n, string_len);
2825 o->length += 0x10 * sizeof(list[0]);
2827 debug_printf_list("list[%d]=%d string_start=%d\n",
2828 n, string_len, string_start);
2831 /* We have empty slot at list[n], reuse without growth */
2832 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2833 string_len = o->length - string_start;
2834 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2835 n, string_len, string_start);
2836 o->has_empty_slot = 0;
2838 o->has_quoted_part = 0;
2839 list[n] = (char*)(uintptr_t)string_len;
2843 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2844 static int o_get_last_ptr(o_string *o, int n)
2846 char **list = (char**)o->data;
2847 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2849 return ((int)(uintptr_t)list[n-1]) + string_start;
2852 #if ENABLE_HUSH_BRACE_EXPANSION
2853 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2854 * first, it processes even {a} (no commas), second,
2855 * I didn't manage to make it return strings when they don't match
2856 * existing files. Need to re-implement it.
2860 static int glob_needed(const char *s)
2869 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2875 /* Return pointer to next closing brace or to comma */
2876 static const char *next_brace_sub(const char *cp)
2880 while (*cp != '\0') {
2887 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2893 return *cp != '\0' ? cp : NULL;
2895 /* Recursive brace globber. Note: may garble pattern[]. */
2896 static int glob_brace(char *pattern, o_string *o, int n)
2898 char *new_pattern_buf;
2905 debug_printf_glob("glob_brace('%s')\n", pattern);
2911 if (*begin == '{') {
2912 /* Find the first sub-pattern and at the same time
2913 * find the rest after the closing brace */
2914 next = next_brace_sub(begin);
2916 /* An illegal expression */
2920 /* "{abc}" with no commas - illegal
2921 * brace expr, disregard and skip it */
2927 if (*begin == '\\' && begin[1] != '\0')
2931 debug_printf_glob("begin:%s\n", begin);
2932 debug_printf_glob("next:%s\n", next);
2934 /* Now find the end of the whole brace expression */
2936 while (*rest != '}') {
2937 rest = next_brace_sub(rest);
2939 /* An illegal expression */
2942 debug_printf_glob("rest:%s\n", rest);
2944 rest_len = strlen(++rest) + 1;
2946 /* We are sure the brace expression is well-formed */
2948 /* Allocate working buffer large enough for our work */
2949 new_pattern_buf = xmalloc(strlen(pattern));
2951 /* We have a brace expression. BEGIN points to the opening {,
2952 * NEXT points past the terminator of the first element, and REST
2953 * points past the final }. We will accumulate result names from
2954 * recursive runs for each brace alternative in the buffer using
2959 /* Construct the new glob expression */
2962 mempcpy(new_pattern_buf,
2963 /* We know the prefix for all sub-patterns */
2964 pattern, begin - pattern),
2968 /* Note: glob_brace() may garble new_pattern_buf[].
2969 * That's why we re-copy prefix every time (1st memcpy above).
2971 n = glob_brace(new_pattern_buf, o, n);
2973 /* We saw the last entry */
2977 next = next_brace_sub(next);
2979 free(new_pattern_buf);
2987 memset(&globdata, 0, sizeof(globdata));
2988 gr = glob(pattern, 0, NULL, &globdata);
2989 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2991 if (gr == GLOB_NOMATCH) {
2992 globfree(&globdata);
2993 /* NB: garbles parameter */
2994 unbackslash(pattern);
2995 o_addstr_with_NUL(o, pattern);
2996 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2997 return o_save_ptr_helper(o, n);
2999 if (gr == GLOB_NOSPACE)
3000 bb_error_msg_and_die(bb_msg_memory_exhausted);
3001 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3002 * but we didn't specify it. Paranoia again. */
3003 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3005 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3006 char **argv = globdata.gl_pathv;
3008 o_addstr_with_NUL(o, *argv);
3009 n = o_save_ptr_helper(o, n);
3015 globfree(&globdata);
3019 /* Performs globbing on last list[],
3020 * saving each result as a new list[].
3022 static int perform_glob(o_string *o, int n)
3024 char *pattern, *copy;
3026 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3028 return o_save_ptr_helper(o, n);
3029 pattern = o->data + o_get_last_ptr(o, n);
3030 debug_printf_glob("glob pattern '%s'\n", pattern);
3031 if (!glob_needed(pattern)) {
3032 /* unbackslash last string in o in place, fix length */
3033 o->length = unbackslash(pattern) - o->data;
3034 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3035 return o_save_ptr_helper(o, n);
3038 copy = xstrdup(pattern);
3039 /* "forget" pattern in o */
3040 o->length = pattern - o->data;
3041 n = glob_brace(copy, o, n);
3044 debug_print_list("perform_glob returning", o, n);
3048 #else /* !HUSH_BRACE_EXPANSION */
3051 static int glob_needed(const char *s)
3060 if (*s == '*' || *s == '[' || *s == '?')
3066 /* Performs globbing on last list[],
3067 * saving each result as a new list[].
3069 static int perform_glob(o_string *o, int n)
3075 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3077 return o_save_ptr_helper(o, n);
3078 pattern = o->data + o_get_last_ptr(o, n);
3079 debug_printf_glob("glob pattern '%s'\n", pattern);
3080 if (!glob_needed(pattern)) {
3082 /* unbackslash last string in o in place, fix length */
3083 o->length = unbackslash(pattern) - o->data;
3084 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3085 return o_save_ptr_helper(o, n);
3088 memset(&globdata, 0, sizeof(globdata));
3089 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3090 * If we glob "*.\*" and don't find anything, we need
3091 * to fall back to using literal "*.*", but GLOB_NOCHECK
3092 * will return "*.\*"!
3094 gr = glob(pattern, 0, NULL, &globdata);
3095 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3097 if (gr == GLOB_NOMATCH) {
3098 globfree(&globdata);
3101 if (gr == GLOB_NOSPACE)
3102 bb_error_msg_and_die(bb_msg_memory_exhausted);
3103 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3104 * but we didn't specify it. Paranoia again. */
3105 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3107 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3108 char **argv = globdata.gl_pathv;
3109 /* "forget" pattern in o */
3110 o->length = pattern - o->data;
3112 o_addstr_with_NUL(o, *argv);
3113 n = o_save_ptr_helper(o, n);
3119 globfree(&globdata);
3121 debug_print_list("perform_glob returning", o, n);
3125 #endif /* !HUSH_BRACE_EXPANSION */
3127 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3128 * Otherwise, just finish current list[] and start new */
3129 static int o_save_ptr(o_string *o, int n)
3131 if (o->o_expflags & EXP_FLAG_GLOB) {
3132 /* If o->has_empty_slot, list[n] was already globbed
3133 * (if it was requested back then when it was filled)
3134 * so don't do that again! */
3135 if (!o->has_empty_slot)
3136 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3138 return o_save_ptr_helper(o, n);
3141 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3142 static char **o_finalize_list(o_string *o, int n)
3147 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3149 debug_print_list("finalized", o, n);
3150 debug_printf_expand("finalized n:%d\n", n);
3151 list = (char**)o->data;
3152 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3156 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3161 static void free_pipe_list(struct pipe *pi);
3163 /* Returns pi->next - next pipe in the list */
3164 static struct pipe *free_pipe(struct pipe *pi)
3169 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3170 for (i = 0; i < pi->num_cmds; i++) {
3171 struct command *command;
3172 struct redir_struct *r, *rnext;
3174 command = &pi->cmds[i];
3175 debug_printf_clean(" command %d:\n", i);
3176 if (command->argv) {
3180 for (a = 0, p = command->argv; *p; a++, p++) {
3181 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3184 free_strings(command->argv);
3185 //command->argv = NULL;
3187 /* not "else if": on syntax error, we may have both! */
3188 if (command->group) {
3189 debug_printf_clean(" begin group (cmd_type:%d)\n",
3191 free_pipe_list(command->group);
3192 debug_printf_clean(" end group\n");
3193 //command->group = NULL;
3195 /* else is crucial here.
3196 * If group != NULL, child_func is meaningless */
3197 #if ENABLE_HUSH_FUNCTIONS
3198 else if (command->child_func) {
3199 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3200 command->child_func->parent_cmd = NULL;
3204 free(command->group_as_string);
3205 //command->group_as_string = NULL;
3207 for (r = command->redirects; r; r = rnext) {
3208 debug_printf_clean(" redirect %d%s",
3209 r->rd_fd, redir_table[r->rd_type].descrip);
3210 /* guard against the case >$FOO, where foo is unset or blank */
3211 if (r->rd_filename) {
3212 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3213 free(r->rd_filename);
3214 //r->rd_filename = NULL;
3216 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3220 //command->redirects = NULL;
3222 free(pi->cmds); /* children are an array, they get freed all at once */
3226 //pi->cmdtext = NULL;
3234 static void free_pipe_list(struct pipe *pi)
3238 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3240 debug_printf_clean("pipe followup code %d\n", pi->followup);
3246 /*** Parsing routines ***/
3248 #ifndef debug_print_tree
3249 static void debug_print_tree(struct pipe *pi, int lvl)
3251 static const char *const PIPE[] = {
3257 static const char *RES[] = {
3258 [RES_NONE ] = "NONE" ,
3261 [RES_THEN ] = "THEN" ,
3262 [RES_ELIF ] = "ELIF" ,
3263 [RES_ELSE ] = "ELSE" ,
3266 # if ENABLE_HUSH_LOOPS
3267 [RES_FOR ] = "FOR" ,
3268 [RES_WHILE] = "WHILE",
3269 [RES_UNTIL] = "UNTIL",
3271 [RES_DONE ] = "DONE" ,
3273 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3276 # if ENABLE_HUSH_CASE
3277 [RES_CASE ] = "CASE" ,
3278 [RES_CASE_IN ] = "CASE_IN" ,
3279 [RES_MATCH] = "MATCH",
3280 [RES_CASE_BODY] = "CASE_BODY",
3281 [RES_ESAC ] = "ESAC" ,
3283 [RES_XXXX ] = "XXXX" ,
3284 [RES_SNTX ] = "SNTX" ,
3286 static const char *const CMDTYPE[] = {
3290 # if ENABLE_HUSH_FUNCTIONS
3299 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3300 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3302 while (prn < pi->num_cmds) {
3303 struct command *command = &pi->cmds[prn];
3304 char **argv = command->argv;
3306 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3308 command->assignment_cnt);
3309 if (command->group) {
3310 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3311 CMDTYPE[command->cmd_type],
3314 , " group_as_string:", command->group_as_string
3319 debug_print_tree(command->group, lvl+1);
3323 if (argv) while (*argv) {
3324 fdprintf(2, " '%s'", *argv);
3334 #endif /* debug_print_tree */
3336 static struct pipe *new_pipe(void)
3339 pi = xzalloc(sizeof(struct pipe));
3340 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3344 /* Command (member of a pipe) is complete, or we start a new pipe
3345 * if ctx->command is NULL.
3346 * No errors possible here.
3348 static int done_command(struct parse_context *ctx)
3350 /* The command is really already in the pipe structure, so
3351 * advance the pipe counter and make a new, null command. */
3352 struct pipe *pi = ctx->pipe;
3353 struct command *command = ctx->command;
3355 #if 0 /* Instead we emit error message at run time */
3356 if (ctx->pending_redirect) {
3357 /* For example, "cmd >" (no filename to redirect to) */
3358 die_if_script("syntax error: %s", "invalid redirect");
3359 ctx->pending_redirect = NULL;
3364 if (IS_NULL_CMD(command)) {
3365 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3369 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3370 //debug_print_tree(ctx->list_head, 20);
3372 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3375 /* Only real trickiness here is that the uncommitted
3376 * command structure is not counted in pi->num_cmds. */
3377 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3378 ctx->command = command = &pi->cmds[pi->num_cmds];
3380 memset(command, 0, sizeof(*command));
3381 return pi->num_cmds; /* used only for 0/nonzero check */
3384 static void done_pipe(struct parse_context *ctx, pipe_style type)
3388 debug_printf_parse("done_pipe entered, followup %d\n", type);
3389 /* Close previous command */
3390 not_null = done_command(ctx);
3392 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3393 ctx->ctx_inverted = 0;
3394 ctx->pipe->res_word = ctx->ctx_res_w;
3396 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3397 /* Necessary since && and || have precedence over &:
3398 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3399 * in a backgrounded subshell.
3402 struct command *command;
3404 /* Is this actually this construct, all pipes end with && or ||? */
3405 pi = ctx->list_head;
3406 while (pi != ctx->pipe) {
3407 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3412 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3413 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3414 pi = xzalloc(sizeof(*pi));
3415 pi->followup = PIPE_BG;
3417 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3418 command = &pi->cmds[0];
3419 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3420 command->cmd_type = CMD_NORMAL;
3421 command->group = ctx->list_head;
3423 command->group_as_string = xstrndup(
3424 ctx->as_string.data,
3425 ctx->as_string.length - 1 /* do not copy last char, "&" */
3428 /* Replace all pipes in ctx with one newly created */
3429 ctx->list_head = ctx->pipe = pi;
3432 ctx->pipe->followup = type;
3435 /* Without this check, even just <enter> on command line generates
3436 * tree of three NOPs (!). Which is harmless but annoying.
3437 * IOW: it is safe to do it unconditionally. */
3440 || ctx->ctx_res_w == RES_FI
3442 #if ENABLE_HUSH_LOOPS
3443 || ctx->ctx_res_w == RES_DONE
3444 || ctx->ctx_res_w == RES_FOR
3445 || ctx->ctx_res_w == RES_IN
3447 #if ENABLE_HUSH_CASE
3448 || ctx->ctx_res_w == RES_ESAC
3452 debug_printf_parse("done_pipe: adding new pipe: "
3453 "not_null:%d ctx->ctx_res_w:%d\n",
3454 not_null, ctx->ctx_res_w);
3456 ctx->pipe->next = new_p;
3458 /* RES_THEN, RES_DO etc are "sticky" -
3459 * they remain set for pipes inside if/while.
3460 * This is used to control execution.
3461 * RES_FOR and RES_IN are NOT sticky (needed to support
3462 * cases where variable or value happens to match a keyword):
3464 #if ENABLE_HUSH_LOOPS
3465 if (ctx->ctx_res_w == RES_FOR
3466 || ctx->ctx_res_w == RES_IN)
3467 ctx->ctx_res_w = RES_NONE;
3469 #if ENABLE_HUSH_CASE
3470 if (ctx->ctx_res_w == RES_MATCH)
3471 ctx->ctx_res_w = RES_CASE_BODY;
3472 if (ctx->ctx_res_w == RES_CASE)
3473 ctx->ctx_res_w = RES_CASE_IN;
3475 ctx->command = NULL; /* trick done_command below */
3476 /* Create the memory for command, roughly:
3477 * ctx->pipe->cmds = new struct command;
3478 * ctx->command = &ctx->pipe->cmds[0];
3481 //debug_print_tree(ctx->list_head, 10);
3483 debug_printf_parse("done_pipe return\n");
3486 static void initialize_context(struct parse_context *ctx)
3488 memset(ctx, 0, sizeof(*ctx));
3489 ctx->pipe = ctx->list_head = new_pipe();
3490 /* Create the memory for command, roughly:
3491 * ctx->pipe->cmds = new struct command;
3492 * ctx->command = &ctx->pipe->cmds[0];
3497 /* If a reserved word is found and processed, parse context is modified
3498 * and 1 is returned.
3501 struct reserved_combo {
3504 unsigned char assignment_flag;
3508 FLAG_END = (1 << RES_NONE ),
3510 FLAG_IF = (1 << RES_IF ),
3511 FLAG_THEN = (1 << RES_THEN ),
3512 FLAG_ELIF = (1 << RES_ELIF ),
3513 FLAG_ELSE = (1 << RES_ELSE ),
3514 FLAG_FI = (1 << RES_FI ),
3516 # if ENABLE_HUSH_LOOPS
3517 FLAG_FOR = (1 << RES_FOR ),
3518 FLAG_WHILE = (1 << RES_WHILE),
3519 FLAG_UNTIL = (1 << RES_UNTIL),
3520 FLAG_DO = (1 << RES_DO ),
3521 FLAG_DONE = (1 << RES_DONE ),
3522 FLAG_IN = (1 << RES_IN ),
3524 # if ENABLE_HUSH_CASE
3525 FLAG_MATCH = (1 << RES_MATCH),
3526 FLAG_ESAC = (1 << RES_ESAC ),
3528 FLAG_START = (1 << RES_XXXX ),
3531 static const struct reserved_combo* match_reserved_word(o_string *word)
3533 /* Mostly a list of accepted follow-up reserved words.
3534 * FLAG_END means we are done with the sequence, and are ready
3535 * to turn the compound list into a command.
3536 * FLAG_START means the word must start a new compound list.
3538 static const struct reserved_combo reserved_list[] = {
3540 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3541 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3542 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3543 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3544 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3545 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3547 # if ENABLE_HUSH_LOOPS
3548 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3549 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3550 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3551 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3552 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3553 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3555 # if ENABLE_HUSH_CASE
3556 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3557 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3560 const struct reserved_combo *r;
3562 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3563 if (strcmp(word->data, r->literal) == 0)
3568 /* Return 0: not a keyword, 1: keyword
3570 static int reserved_word(o_string *word, struct parse_context *ctx)
3572 # if ENABLE_HUSH_CASE
3573 static const struct reserved_combo reserved_match = {
3574 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3577 const struct reserved_combo *r;
3579 if (word->has_quoted_part)
3581 r = match_reserved_word(word);
3585 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3586 # if ENABLE_HUSH_CASE
3587 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3588 /* "case word IN ..." - IN part starts first MATCH part */
3589 r = &reserved_match;
3592 if (r->flag == 0) { /* '!' */
3593 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3594 syntax_error("! ! command");
3595 ctx->ctx_res_w = RES_SNTX;
3597 ctx->ctx_inverted = 1;
3600 if (r->flag & FLAG_START) {
3601 struct parse_context *old;
3603 old = xmemdup(ctx, sizeof(*ctx));
3604 debug_printf_parse("push stack %p\n", old);
3605 initialize_context(ctx);
3607 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3608 syntax_error_at(word->data);
3609 ctx->ctx_res_w = RES_SNTX;
3612 /* "{...} fi" is ok. "{...} if" is not
3614 * if { echo foo; } then { echo bar; } fi */
3615 if (ctx->command->group)
3616 done_pipe(ctx, PIPE_SEQ);
3619 ctx->ctx_res_w = r->res;
3620 ctx->old_flag = r->flag;
3621 word->o_assignment = r->assignment_flag;
3622 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3624 if (ctx->old_flag & FLAG_END) {
3625 struct parse_context *old;
3627 done_pipe(ctx, PIPE_SEQ);
3628 debug_printf_parse("pop stack %p\n", ctx->stack);
3630 old->command->group = ctx->list_head;
3631 old->command->cmd_type = CMD_NORMAL;
3633 /* At this point, the compound command's string is in
3634 * ctx->as_string... except for the leading keyword!
3635 * Consider this example: "echo a | if true; then echo a; fi"
3636 * ctx->as_string will contain "true; then echo a; fi",
3637 * with "if " remaining in old->as_string!
3641 int len = old->as_string.length;
3642 /* Concatenate halves */
3643 o_addstr(&old->as_string, ctx->as_string.data);
3644 o_free_unsafe(&ctx->as_string);
3645 /* Find where leading keyword starts in first half */
3646 str = old->as_string.data + len;
3647 if (str > old->as_string.data)
3648 str--; /* skip whitespace after keyword */
3649 while (str > old->as_string.data && isalpha(str[-1]))
3651 /* Ugh, we're done with this horrid hack */
3652 old->command->group_as_string = xstrdup(str);
3653 debug_printf_parse("pop, remembering as:'%s'\n",
3654 old->command->group_as_string);
3657 *ctx = *old; /* physical copy */
3662 #endif /* HAS_KEYWORDS */
3664 /* Word is complete, look at it and update parsing context.
3665 * Normal return is 0. Syntax errors return 1.
3666 * Note: on return, word is reset, but not o_free'd!
3668 static int done_word(o_string *word, struct parse_context *ctx)
3670 struct command *command = ctx->command;
3672 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3673 if (word->length == 0 && !word->has_quoted_part) {
3674 debug_printf_parse("done_word return 0: true null, ignored\n");
3678 if (ctx->pending_redirect) {
3679 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3680 * only if run as "bash", not "sh" */
3681 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3683 * ...the word that follows the redirection operator
3684 * shall be subjected to tilde expansion, parameter expansion,
3685 * command substitution, arithmetic expansion, and quote
3686 * removal. Pathname expansion shall not be performed
3687 * on the word by a non-interactive shell; an interactive
3688 * shell may perform it, but shall do so only when
3689 * the expansion would result in one word."
3691 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3692 /* Cater for >\file case:
3693 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3694 * Same with heredocs:
3695 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3697 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3698 unbackslash(ctx->pending_redirect->rd_filename);
3699 /* Is it <<"HEREDOC"? */
3700 if (word->has_quoted_part) {
3701 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3704 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3705 ctx->pending_redirect = NULL;
3708 # if ENABLE_HUSH_CASE
3709 if (ctx->ctx_dsemicolon
3710 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3712 /* already done when ctx_dsemicolon was set to 1: */
3713 /* ctx->ctx_res_w = RES_MATCH; */
3714 ctx->ctx_dsemicolon = 0;
3717 if (!command->argv /* if it's the first word... */
3718 # if ENABLE_HUSH_LOOPS
3719 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3720 && ctx->ctx_res_w != RES_IN
3722 # if ENABLE_HUSH_CASE
3723 && ctx->ctx_res_w != RES_CASE
3726 int reserved = reserved_word(word, ctx);
3727 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3729 o_reset_to_empty_unquoted(word);
3730 debug_printf_parse("done_word return %d\n",
3731 (ctx->ctx_res_w == RES_SNTX));
3732 return (ctx->ctx_res_w == RES_SNTX);
3735 if (strcmp(word->data, "[[") == 0) {
3736 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3742 if (command->group) {
3743 /* "{ echo foo; } echo bar" - bad */
3744 syntax_error_at(word->data);
3745 debug_printf_parse("done_word return 1: syntax error, "
3746 "groups and arglists don't mix\n");
3750 /* If this word wasn't an assignment, next ones definitely
3751 * can't be assignments. Even if they look like ones. */
3752 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3753 && word->o_assignment != WORD_IS_KEYWORD
3755 word->o_assignment = NOT_ASSIGNMENT;
3757 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3758 command->assignment_cnt++;
3759 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3761 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3762 word->o_assignment = MAYBE_ASSIGNMENT;
3764 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3766 if (word->has_quoted_part
3767 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3768 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3769 /* (otherwise it's known to be not empty and is already safe) */
3771 /* exclude "$@" - it can expand to no word despite "" */
3772 char *p = word->data;
3773 while (p[0] == SPECIAL_VAR_SYMBOL
3774 && (p[1] & 0x7f) == '@'
3775 && p[2] == SPECIAL_VAR_SYMBOL
3780 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3781 debug_print_strings("word appended to argv", command->argv);
3784 #if ENABLE_HUSH_LOOPS
3785 if (ctx->ctx_res_w == RES_FOR) {
3786 if (word->has_quoted_part
3787 || !is_well_formed_var_name(command->argv[0], '\0')
3789 /* bash says just "not a valid identifier" */
3790 syntax_error("not a valid identifier in for");
3793 /* Force FOR to have just one word (variable name) */
3794 /* NB: basically, this makes hush see "for v in ..."
3795 * syntax as if it is "for v; in ...". FOR and IN become
3796 * two pipe structs in parse tree. */
3797 done_pipe(ctx, PIPE_SEQ);
3800 #if ENABLE_HUSH_CASE
3801 /* Force CASE to have just one word */
3802 if (ctx->ctx_res_w == RES_CASE) {
3803 done_pipe(ctx, PIPE_SEQ);
3807 o_reset_to_empty_unquoted(word);
3809 debug_printf_parse("done_word return 0\n");
3814 /* Peek ahead in the input to find out if we have a "&n" construct,
3815 * as in "2>&1", that represents duplicating a file descriptor.
3817 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3818 * REDIRFD_SYNTAX_ERR if syntax error,
3819 * REDIRFD_TO_FILE if no & was seen,
3820 * or the number found.
3823 #define parse_redir_right_fd(as_string, input) \
3824 parse_redir_right_fd(input)
3826 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3832 return REDIRFD_TO_FILE;
3834 ch = i_getch(input); /* get the & */
3835 nommu_addchr(as_string, ch);
3838 ch = i_getch(input);
3839 nommu_addchr(as_string, ch);
3840 return REDIRFD_CLOSE;
3844 while (ch != EOF && isdigit(ch)) {
3845 d = d*10 + (ch-'0');
3847 ch = i_getch(input);
3848 nommu_addchr(as_string, ch);
3853 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3855 bb_error_msg("ambiguous redirect");
3856 return REDIRFD_SYNTAX_ERR;
3859 /* Return code is 0 normal, 1 if a syntax error is detected
3861 static int parse_redirect(struct parse_context *ctx,
3864 struct in_str *input)
3866 struct command *command = ctx->command;
3867 struct redir_struct *redir;
3868 struct redir_struct **redirp;
3871 dup_num = REDIRFD_TO_FILE;
3872 if (style != REDIRECT_HEREDOC) {
3873 /* Check for a '>&1' type redirect */
3874 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3875 if (dup_num == REDIRFD_SYNTAX_ERR)
3878 int ch = i_peek(input);
3879 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3880 if (dup_num) { /* <<-... */
3881 ch = i_getch(input);
3882 nommu_addchr(&ctx->as_string, ch);
3887 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3888 int ch = i_peek(input);
3890 /* >|FILE redirect ("clobbering" >).
3891 * Since we do not support "set -o noclobber" yet,
3892 * >| and > are the same for now. Just eat |.
3894 ch = i_getch(input);
3895 nommu_addchr(&ctx->as_string, ch);
3899 /* Create a new redir_struct and append it to the linked list */
3900 redirp = &command->redirects;
3901 while ((redir = *redirp) != NULL) {
3902 redirp = &(redir->next);
3904 *redirp = redir = xzalloc(sizeof(*redir));
3905 /* redir->next = NULL; */
3906 /* redir->rd_filename = NULL; */
3907 redir->rd_type = style;
3908 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3910 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3911 redir_table[style].descrip);
3913 redir->rd_dup = dup_num;
3914 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3915 /* Erik had a check here that the file descriptor in question
3916 * is legit; I postpone that to "run time"
3917 * A "-" representation of "close me" shows up as a -3 here */
3918 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3919 redir->rd_fd, redir->rd_dup);
3921 #if 0 /* Instead we emit error message at run time */
3922 if (ctx->pending_redirect) {
3923 /* For example, "cmd > <file" */
3924 die_if_script("syntax error: %s", "invalid redirect");
3927 /* Set ctx->pending_redirect, so we know what to do at the
3928 * end of the next parsed word. */
3929 ctx->pending_redirect = redir;
3934 /* If a redirect is immediately preceded by a number, that number is
3935 * supposed to tell which file descriptor to redirect. This routine
3936 * looks for such preceding numbers. In an ideal world this routine
3937 * needs to handle all the following classes of redirects...
3938 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3939 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3940 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3941 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3943 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3945 * ... If n is quoted, the number shall not be recognized as part of
3946 * the redirection expression. For example:
3948 * writes the character 2 into file a"
3949 * We are getting it right by setting ->has_quoted_part on any \<char>
3951 * A -1 return means no valid number was found,
3952 * the caller should use the appropriate default for this redirection.
3954 static int redirect_opt_num(o_string *o)
3958 if (o->data == NULL)
3960 num = bb_strtou(o->data, NULL, 10);
3961 if (errno || num < 0)
3963 o_reset_to_empty_unquoted(o);
3968 #define fetch_till_str(as_string, input, word, skip_tabs) \
3969 fetch_till_str(input, word, skip_tabs)
3971 static char *fetch_till_str(o_string *as_string,
3972 struct in_str *input,
3976 o_string heredoc = NULL_O_STRING;
3978 int prev = 0; /* not \ */
3984 ch = i_getch(input);
3986 nommu_addchr(as_string, ch);
3987 if ((ch == '\n' || ch == EOF)
3988 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3990 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3991 heredoc.data[past_EOL] = '\0';
3992 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3993 return heredoc.data;
3995 while (ch == '\n') {
3996 o_addchr(&heredoc, ch);
3999 past_EOL = heredoc.length;
4001 ch = i_getch(input);
4003 nommu_addchr(as_string, ch);
4004 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4008 o_free_unsafe(&heredoc);
4011 o_addchr(&heredoc, ch);
4012 nommu_addchr(as_string, ch);
4013 if (prev == '\\' && ch == '\\')
4014 /* Correctly handle foo\\<eol> (not a line cont.) */
4015 prev = 0; /* not \ */
4021 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4022 * and load them all. There should be exactly heredoc_cnt of them.
4024 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4026 struct pipe *pi = ctx->list_head;
4028 while (pi && heredoc_cnt) {
4030 struct command *cmd = pi->cmds;
4032 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4034 cmd->argv ? cmd->argv[0] : "NONE");
4035 for (i = 0; i < pi->num_cmds; i++) {
4036 struct redir_struct *redir = cmd->redirects;
4038 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4039 i, cmd->argv ? cmd->argv[0] : "NONE");
4041 if (redir->rd_type == REDIRECT_HEREDOC) {
4044 redir->rd_type = REDIRECT_HEREDOC2;
4045 /* redir->rd_dup is (ab)used to indicate <<- */
4046 p = fetch_till_str(&ctx->as_string, input,
4047 redir->rd_filename, redir->rd_dup);
4049 syntax_error("unexpected EOF in here document");
4052 free(redir->rd_filename);
4053 redir->rd_filename = p;
4056 redir = redir->next;
4063 /* Should be 0. If it isn't, it's a parse error */
4065 bb_error_msg_and_die("heredoc BUG 2");
4071 static int run_list(struct pipe *pi);
4073 #define parse_stream(pstring, input, end_trigger) \
4074 parse_stream(input, end_trigger)
4076 static struct pipe *parse_stream(char **pstring,
4077 struct in_str *input,
4081 #if !ENABLE_HUSH_FUNCTIONS
4082 #define parse_group(dest, ctx, input, ch) \
4083 parse_group(ctx, input, ch)
4085 static int parse_group(o_string *dest, struct parse_context *ctx,
4086 struct in_str *input, int ch)
4088 /* dest contains characters seen prior to ( or {.
4089 * Typically it's empty, but for function defs,
4090 * it contains function name (without '()'). */
4091 struct pipe *pipe_list;
4093 struct command *command = ctx->command;
4095 debug_printf_parse("parse_group entered\n");
4096 #if ENABLE_HUSH_FUNCTIONS
4097 if (ch == '(' && !dest->has_quoted_part) {
4099 if (done_word(dest, ctx))
4102 goto skip; /* (... */
4103 if (command->argv[1]) { /* word word ... (... */
4104 syntax_error_unexpected_ch('(');
4107 /* it is "word(..." or "word (..." */
4109 ch = i_getch(input);
4110 while (ch == ' ' || ch == '\t');
4112 syntax_error_unexpected_ch(ch);
4115 nommu_addchr(&ctx->as_string, ch);
4117 ch = i_getch(input);
4118 while (ch == ' ' || ch == '\t' || ch == '\n');
4120 syntax_error_unexpected_ch(ch);
4123 nommu_addchr(&ctx->as_string, ch);
4124 command->cmd_type = CMD_FUNCDEF;
4129 #if 0 /* Prevented by caller */
4130 if (command->argv /* word [word]{... */
4131 || dest->length /* word{... */
4132 || dest->has_quoted_part /* ""{... */
4135 debug_printf_parse("parse_group return 1: "
4136 "syntax error, groups and arglists don't mix\n");
4141 #if ENABLE_HUSH_FUNCTIONS
4147 command->cmd_type = CMD_SUBSHELL;
4149 /* bash does not allow "{echo...", requires whitespace */
4151 if (ch != ' ' && ch != '\t' && ch != '\n'
4152 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4154 syntax_error_unexpected_ch(ch);
4158 ch = i_getch(input);
4159 nommu_addchr(&ctx->as_string, ch);
4165 # define as_string NULL
4167 char *as_string = NULL;
4169 pipe_list = parse_stream(&as_string, input, endch);
4172 o_addstr(&ctx->as_string, as_string);
4174 /* empty ()/{} or parse error? */
4175 if (!pipe_list || pipe_list == ERR_PTR) {
4176 /* parse_stream already emitted error msg */
4179 debug_printf_parse("parse_group return 1: "
4180 "parse_stream returned %p\n", pipe_list);
4183 command->group = pipe_list;
4185 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4186 command->group_as_string = as_string;
4187 debug_printf_parse("end of group, remembering as:'%s'\n",
4188 command->group_as_string);
4192 debug_printf_parse("parse_group return 0\n");
4194 /* command remains "open", available for possible redirects */
4197 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4202 ch = i_getch(input);
4205 ch2 = i_peek(input);
4208 /* backslash+newline, skip it */
4213 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4221 ch2 = i_peek2(input);
4224 /* backslash+newline, skip it */
4230 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4231 /* Subroutines for copying $(...) and `...` things */
4232 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4234 static int add_till_single_quote(o_string *dest, struct in_str *input)
4237 int ch = i_getch(input);
4239 syntax_error_unterm_ch('\'');
4247 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4248 static int add_till_double_quote(o_string *dest, struct in_str *input)
4251 int ch = i_getch(input);
4253 syntax_error_unterm_ch('"');
4258 if (ch == '\\') { /* \x. Copy both chars. */
4260 ch = i_getch(input);
4264 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4269 //if (ch == '$') ...
4272 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4274 * "Within the backquoted style of command substitution, backslash
4275 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4276 * The search for the matching backquote shall be satisfied by the first
4277 * backquote found without a preceding backslash; during this search,
4278 * if a non-escaped backquote is encountered within a shell comment,
4279 * a here-document, an embedded command substitution of the $(command)
4280 * form, or a quoted string, undefined results occur. A single-quoted
4281 * or double-quoted string that begins, but does not end, within the
4282 * "`...`" sequence produces undefined results."
4284 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4286 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4289 int ch = i_getch(input);
4293 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4294 ch = i_getch(input);
4298 && (!in_dquote || ch != '"')
4300 o_addchr(dest, '\\');
4304 syntax_error_unterm_ch('`');
4310 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4311 * quoting and nested ()s.
4312 * "With the $(command) style of command substitution, all characters
4313 * following the open parenthesis to the matching closing parenthesis
4314 * constitute the command. Any valid shell script can be used for command,
4315 * except a script consisting solely of redirections which produces
4316 * unspecified results."
4318 * echo $(echo '(TEST)' BEST) (TEST) BEST
4319 * echo $(echo 'TEST)' BEST) TEST) BEST
4320 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4322 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4323 * can contain arbitrary constructs, just like $(cmd).
4324 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4325 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4327 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4328 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4331 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4332 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4333 char end_char2 = end_ch >> 8;
4335 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4338 ch = i_getch(input);
4340 syntax_error_unterm_ch(end_ch);
4344 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4350 /* we look for closing )) of $((EXPR)) */
4351 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4352 i_getch(input); /* eat second ')' */
4357 if (ch == '(' || ch == '{') {
4358 ch = (ch == '(' ? ')' : '}');
4359 if (!add_till_closing_bracket(dest, input, ch))
4365 if (!add_till_single_quote(dest, input))
4371 if (!add_till_double_quote(dest, input))
4377 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4383 /* \x. Copy verbatim. Important for \(, \) */
4384 ch = i_getch(input);
4386 syntax_error_unterm_ch(')');
4391 /* "backslash+newline", ignore both */
4392 o_delchr(dest); /* undo insertion of '\' */
4402 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4404 /* Return code: 0 for OK, 1 for syntax error */
4406 #define parse_dollar(as_string, dest, input, quote_mask) \
4407 parse_dollar(dest, input, quote_mask)
4408 #define as_string NULL
4410 static int parse_dollar(o_string *as_string,
4412 struct in_str *input, unsigned char quote_mask)
4414 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4416 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4418 ch = i_getch(input);
4419 nommu_addchr(as_string, ch);
4421 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4423 debug_printf_parse(": '%c'\n", ch);
4424 o_addchr(dest, ch | quote_mask);
4426 ch = i_peek_and_eat_bkslash_nl(input);
4427 if (!isalnum(ch) && ch != '_') {
4428 /* End of variable name reached */
4431 ch = i_getch(input);
4432 nommu_addchr(as_string, ch);
4434 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4435 } else if (isdigit(ch)) {
4437 ch = i_getch(input);
4438 nommu_addchr(as_string, ch);
4439 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4440 debug_printf_parse(": '%c'\n", ch);
4441 o_addchr(dest, ch | quote_mask);
4442 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4443 } else switch (ch) {
4445 case '!': /* last bg pid */
4446 case '?': /* last exit code */
4447 case '#': /* number of args */
4448 case '*': /* args */
4449 case '@': /* args */
4450 goto make_one_char_var;
4452 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4454 ch = i_getch(input); /* eat '{' */
4455 nommu_addchr(as_string, ch);
4457 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4458 /* It should be ${?}, or ${#var},
4459 * or even ${?+subst} - operator acting on a special variable,
4460 * or the beginning of variable name.
4463 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4466 syntax_error_unterm_str("${name}");
4467 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4470 nommu_addchr(as_string, ch);
4473 /* It's possible to just call add_till_closing_bracket() at this point.
4474 * However, this regresses some of our testsuite cases
4475 * which check invalid constructs like ${%}.
4476 * Oh well... let's check that the var name part is fine... */
4482 debug_printf_parse(": '%c'\n", ch);
4484 ch = i_getch(input);
4485 nommu_addchr(as_string, ch);
4489 if (!isalnum(ch) && ch != '_') {
4491 unsigned char last_ch;
4492 /* handle parameter expansions
4493 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4495 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4496 goto bad_dollar_syntax;
4498 /* Eat everything until closing '}' (or ':') */
4502 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4504 /* It's ${var:N[:M]} thing */
4505 end_ch = '}' * 0x100 + ':';
4507 if (BASH_PATTERN_SUBST
4510 /* It's ${var/[/]pattern[/repl]} thing */
4511 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4513 nommu_addchr(as_string, '/');
4516 end_ch = '}' * 0x100 + '/';
4522 #if ENABLE_HUSH_DOLLAR_OPS
4523 last_ch = add_till_closing_bracket(dest, input, end_ch);
4524 if (last_ch == 0) /* error? */
4527 #error Simple code to only allow ${var} is not implemented
4530 o_addstr(as_string, dest->data + pos);
4531 o_addchr(as_string, last_ch);
4534 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4535 && (end_ch & 0xff00)
4537 /* close the first block: */
4538 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4539 /* while parsing N from ${var:N[:M]}
4540 * or pattern from ${var/[/]pattern[/repl]} */
4541 if ((end_ch & 0xff) == last_ch) {
4542 /* got ':' or '/'- parse the rest */
4547 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4548 /* it's ${var:N} - emulate :999999999 */
4549 o_addstr(dest, "999999999");
4550 } /* else: it's ${var/[/]pattern} */
4555 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4558 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4562 ch = i_getch(input);
4563 nommu_addchr(as_string, ch);
4564 # if ENABLE_FEATURE_SH_MATH
4565 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4566 ch = i_getch(input);
4567 nommu_addchr(as_string, ch);
4568 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4569 o_addchr(dest, /*quote_mask |*/ '+');
4572 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4573 return 0; /* error */
4575 o_addstr(as_string, dest->data + pos);
4576 o_addchr(as_string, ')');
4577 o_addchr(as_string, ')');
4579 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4583 # if ENABLE_HUSH_TICK
4584 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4585 o_addchr(dest, quote_mask | '`');
4588 if (!add_till_closing_bracket(dest, input, ')'))
4589 return 0; /* error */
4591 o_addstr(as_string, dest->data + pos);
4592 o_addchr(as_string, ')');
4594 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4600 ch = i_getch(input);
4601 nommu_addchr(as_string, ch);
4602 ch = i_peek_and_eat_bkslash_nl(input);
4603 if (isalnum(ch)) { /* it's $_name or $_123 */
4608 /* TODO: $_ and $-: */
4609 /* $_ Shell or shell script name; or last argument of last command
4610 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4611 * but in command's env, set to full pathname used to invoke it */
4612 /* $- Option flags set by set builtin or shell options (-i etc) */
4614 o_addQchr(dest, '$');
4616 debug_printf_parse("parse_dollar return 1 (ok)\n");
4622 # if BASH_PATTERN_SUBST
4623 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4624 encode_string(dest, input, dquote_end, process_bkslash)
4626 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4627 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4628 encode_string(dest, input, dquote_end)
4630 #define as_string NULL
4634 # if BASH_PATTERN_SUBST
4635 /* all parameters are needed, no macro tricks */
4637 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4638 encode_string(as_string, dest, input, dquote_end)
4641 static int encode_string(o_string *as_string,
4643 struct in_str *input,
4645 int process_bkslash)
4647 #if !BASH_PATTERN_SUBST
4648 const int process_bkslash = 1;
4654 ch = i_getch(input);
4656 nommu_addchr(as_string, ch);
4657 if (ch == dquote_end) { /* may be only '"' or EOF */
4658 debug_printf_parse("encode_string return 1 (ok)\n");
4661 /* note: can't move it above ch == dquote_end check! */
4663 syntax_error_unterm_ch('"');
4664 return 0; /* error */
4668 next = i_peek(input);
4670 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4671 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4672 if (process_bkslash && ch == '\\') {
4674 syntax_error("\\<eof>");
4678 * "The backslash retains its special meaning [in "..."]
4679 * only when followed by one of the following characters:
4680 * $, `, ", \, or <newline>. A double quote may be quoted
4681 * within double quotes by preceding it with a backslash."
4682 * NB: in (unquoted) heredoc, above does not apply to ",
4683 * therefore we check for it by "next == dquote_end" cond.
4685 if (next == dquote_end || strchr("$`\\\n", next)) {
4686 ch = i_getch(input); /* eat next */
4688 goto again; /* skip \<newline> */
4689 } /* else: ch remains == '\\', and we double it below: */
4690 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4691 nommu_addchr(as_string, ch);
4695 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4696 debug_printf_parse("encode_string return 0: "
4697 "parse_dollar returned 0 (error)\n");
4702 #if ENABLE_HUSH_TICK
4704 //unsigned pos = dest->length;
4705 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4706 o_addchr(dest, 0x80 | '`');
4707 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4708 return 0; /* error */
4709 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4710 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4714 o_addQchr(dest, ch);
4720 * Scan input until EOF or end_trigger char.
4721 * Return a list of pipes to execute, or NULL on EOF
4722 * or if end_trigger character is met.
4723 * On syntax error, exit if shell is not interactive,
4724 * reset parsing machinery and start parsing anew,
4725 * or return ERR_PTR.
4727 static struct pipe *parse_stream(char **pstring,
4728 struct in_str *input,
4731 struct parse_context ctx;
4732 o_string dest = NULL_O_STRING;
4735 /* Single-quote triggers a bypass of the main loop until its mate is
4736 * found. When recursing, quote state is passed in via dest->o_expflags.
4738 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4739 end_trigger ? end_trigger : 'X');
4742 /* If very first arg is "" or '', dest.data may end up NULL.
4743 * Preventing this: */
4744 o_addchr(&dest, '\0');
4747 /* We used to separate words on $IFS here. This was wrong.
4748 * $IFS is used only for word splitting when $var is expanded,
4749 * here we should use blank chars as separators, not $IFS
4752 if (MAYBE_ASSIGNMENT != 0)
4753 dest.o_assignment = MAYBE_ASSIGNMENT;
4754 initialize_context(&ctx);
4757 const char *is_blank;
4758 const char *is_special;
4762 redir_type redir_style;
4764 ch = i_getch(input);
4765 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4766 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4771 syntax_error_unterm_str("here document");
4774 if (end_trigger == ')') {
4775 syntax_error_unterm_ch('(');
4778 if (end_trigger == '}') {
4779 syntax_error_unterm_ch('{');
4783 if (done_word(&dest, &ctx)) {
4787 done_pipe(&ctx, PIPE_SEQ);
4789 /* If we got nothing... */
4790 /* (this makes bare "&" cmd a no-op.
4791 * bash says: "syntax error near unexpected token '&'") */
4792 if (pi->num_cmds == 0
4793 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4799 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4801 *pstring = ctx.as_string.data;
4803 o_free_unsafe(&ctx.as_string);
4806 debug_printf_parse("parse_stream return %p\n", pi);
4809 nommu_addchr(&ctx.as_string, ch);
4813 next = i_peek(input);
4815 is_special = "{}<>;&|()#'" /* special outside of "str" */
4816 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4817 /* Are { and } special here? */
4818 if (ctx.command->argv /* word [word]{... - non-special */
4819 || dest.length /* word{... - non-special */
4820 || dest.has_quoted_part /* ""{... - non-special */
4821 || (next != ';' /* }; - special */
4822 && next != ')' /* }) - special */
4823 && next != '(' /* {( - special */
4824 && next != '&' /* }& and }&& ... - special */
4825 && next != '|' /* }|| ... - special */
4826 && !strchr(defifs, next) /* {word - non-special */
4829 /* They are not special, skip "{}" */
4832 is_special = strchr(is_special, ch);
4833 is_blank = strchr(defifs, ch);
4835 if (!is_special && !is_blank) { /* ordinary char */
4837 o_addQchr(&dest, ch);
4838 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4839 || dest.o_assignment == WORD_IS_KEYWORD)
4841 && is_well_formed_var_name(dest.data, '=')
4843 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4844 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4850 if (done_word(&dest, &ctx)) {
4854 /* Is this a case when newline is simply ignored?
4856 * "cmd | <newline> cmd ..."
4857 * "case ... in <newline> word) ..."
4859 if (IS_NULL_CMD(ctx.command)
4860 && dest.length == 0 && !dest.has_quoted_part
4862 /* This newline can be ignored. But...
4863 * Without check #1, interactive shell
4864 * ignores even bare <newline>,
4865 * and shows the continuation prompt:
4866 * ps1_prompt$ <enter>
4867 * ps2> _ <=== wrong, should be ps1
4868 * Without check #2, "cmd & <newline>"
4869 * is similarly mistreated.
4870 * (BTW, this makes "cmd & cmd"
4871 * and "cmd && cmd" non-orthogonal.
4872 * Really, ask yourself, why
4873 * "cmd && <newline>" doesn't start
4874 * cmd but waits for more input?
4875 * The only reason is that it might be
4876 * a "cmd1 && <nl> cmd2 &" construct,
4877 * cmd1 may need to run in BG).
4879 struct pipe *pi = ctx.list_head;
4880 if (pi->num_cmds != 0 /* check #1 */
4881 && pi->followup != PIPE_BG /* check #2 */
4886 /* Treat newline as a command separator. */
4887 done_pipe(&ctx, PIPE_SEQ);
4888 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4890 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4895 dest.o_assignment = MAYBE_ASSIGNMENT;
4896 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4898 /* note: if (is_blank) continue;
4899 * will still trigger for us */
4903 /* "cmd}" or "cmd }..." without semicolon or &:
4904 * } is an ordinary char in this case, even inside { cmd; }
4905 * Pathological example: { ""}; } should exec "}" cmd
4908 if (dest.length != 0 /* word} */
4909 || dest.has_quoted_part /* ""} */
4913 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4914 /* Generally, there should be semicolon: "cmd; }"
4915 * However, bash allows to omit it if "cmd" is
4916 * a group. Examples:
4919 * { echo 0 >&2 | { echo 1; } }
4920 * { while false; do :; done }
4921 * { case a in b) ;; esac }
4923 if (ctx.command->group)
4927 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4928 /* Can't be an end of {cmd}, skip the check */
4929 goto skip_end_trigger;
4930 /* else: } does terminate a group */
4933 if (end_trigger && end_trigger == ch
4934 && (ch != ';' || heredoc_cnt == 0)
4935 #if ENABLE_HUSH_CASE
4937 || ctx.ctx_res_w != RES_MATCH
4938 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4943 /* This is technically valid:
4944 * { cat <<HERE; }; echo Ok
4948 * but we don't support this.
4949 * We require heredoc to be in enclosing {}/(),
4952 syntax_error_unterm_str("here document");
4955 if (done_word(&dest, &ctx)) {
4958 done_pipe(&ctx, PIPE_SEQ);
4959 dest.o_assignment = MAYBE_ASSIGNMENT;
4960 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4961 /* Do we sit outside of any if's, loops or case's? */
4963 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4967 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4969 *pstring = ctx.as_string.data;
4971 o_free_unsafe(&ctx.as_string);
4974 debug_printf_parse("parse_stream return %p: "
4975 "end_trigger char found\n",
4977 return ctx.list_head;
4984 /* Catch <, > before deciding whether this word is
4985 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4988 redir_fd = redirect_opt_num(&dest);
4989 if (done_word(&dest, &ctx)) {
4992 redir_style = REDIRECT_OVERWRITE;
4994 redir_style = REDIRECT_APPEND;
4995 ch = i_getch(input);
4996 nommu_addchr(&ctx.as_string, ch);
4999 else if (next == '(') {
5000 syntax_error(">(process) not supported");
5004 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5006 continue; /* back to top of while (1) */
5008 redir_fd = redirect_opt_num(&dest);
5009 if (done_word(&dest, &ctx)) {
5012 redir_style = REDIRECT_INPUT;
5014 redir_style = REDIRECT_HEREDOC;
5016 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5017 ch = i_getch(input);
5018 nommu_addchr(&ctx.as_string, ch);
5019 } else if (next == '>') {
5020 redir_style = REDIRECT_IO;
5021 ch = i_getch(input);
5022 nommu_addchr(&ctx.as_string, ch);
5025 else if (next == '(') {
5026 syntax_error("<(process) not supported");
5030 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5032 continue; /* back to top of while (1) */
5034 if (dest.length == 0 && !dest.has_quoted_part) {
5035 /* skip "#comment" */
5038 if (ch == EOF || ch == '\n')
5041 /* note: we do not add it to &ctx.as_string */
5043 nommu_addchr(&ctx.as_string, '\n');
5044 continue; /* back to top of while (1) */
5049 /* It's "\<newline>" */
5051 /* Remove trailing '\' from ctx.as_string */
5052 ctx.as_string.data[--ctx.as_string.length] = '\0';
5054 ch = i_getch(input); /* eat it */
5055 continue; /* back to top of while (1) */
5060 if (dest.o_assignment == MAYBE_ASSIGNMENT
5061 /* check that we are not in word in "a=1 2>word b=1": */
5062 && !ctx.pending_redirect
5064 /* ch is a special char and thus this word
5065 * cannot be an assignment */
5066 dest.o_assignment = NOT_ASSIGNMENT;
5067 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5070 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5073 case '#': /* non-comment #: "echo a#b" etc */
5074 o_addQchr(&dest, ch);
5078 syntax_error("\\<eof>");
5081 ch = i_getch(input);
5082 /* note: ch != '\n' (that case does not reach this place) */
5083 o_addchr(&dest, '\\');
5084 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5085 o_addchr(&dest, ch);
5086 nommu_addchr(&ctx.as_string, ch);
5087 /* Example: echo Hello \2>file
5088 * we need to know that word 2 is quoted */
5089 dest.has_quoted_part = 1;
5092 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5093 debug_printf_parse("parse_stream parse error: "
5094 "parse_dollar returned 0 (error)\n");
5099 dest.has_quoted_part = 1;
5100 if (next == '\'' && !ctx.pending_redirect) {
5101 insert_empty_quoted_str_marker:
5102 nommu_addchr(&ctx.as_string, next);
5103 i_getch(input); /* eat second ' */
5104 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5105 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5108 ch = i_getch(input);
5110 syntax_error_unterm_ch('\'');
5113 nommu_addchr(&ctx.as_string, ch);
5116 o_addqchr(&dest, ch);
5121 dest.has_quoted_part = 1;
5122 if (next == '"' && !ctx.pending_redirect)
5123 goto insert_empty_quoted_str_marker;
5124 if (dest.o_assignment == NOT_ASSIGNMENT)
5125 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5126 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5128 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5130 #if ENABLE_HUSH_TICK
5132 USE_FOR_NOMMU(unsigned pos;)
5134 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5135 o_addchr(&dest, '`');
5136 USE_FOR_NOMMU(pos = dest.length;)
5137 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5140 o_addstr(&ctx.as_string, dest.data + pos);
5141 o_addchr(&ctx.as_string, '`');
5143 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5144 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5149 #if ENABLE_HUSH_CASE
5152 if (done_word(&dest, &ctx)) {
5155 done_pipe(&ctx, PIPE_SEQ);
5156 #if ENABLE_HUSH_CASE
5157 /* Eat multiple semicolons, detect
5158 * whether it means something special */
5163 ch = i_getch(input);
5164 nommu_addchr(&ctx.as_string, ch);
5165 if (ctx.ctx_res_w == RES_CASE_BODY) {
5166 ctx.ctx_dsemicolon = 1;
5167 ctx.ctx_res_w = RES_MATCH;
5173 /* We just finished a cmd. New one may start
5174 * with an assignment */
5175 dest.o_assignment = MAYBE_ASSIGNMENT;
5176 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5179 if (done_word(&dest, &ctx)) {
5183 ch = i_getch(input);
5184 nommu_addchr(&ctx.as_string, ch);
5185 done_pipe(&ctx, PIPE_AND);
5187 done_pipe(&ctx, PIPE_BG);
5191 if (done_word(&dest, &ctx)) {
5194 #if ENABLE_HUSH_CASE
5195 if (ctx.ctx_res_w == RES_MATCH)
5196 break; /* we are in case's "word | word)" */
5198 if (next == '|') { /* || */
5199 ch = i_getch(input);
5200 nommu_addchr(&ctx.as_string, ch);
5201 done_pipe(&ctx, PIPE_OR);
5203 /* we could pick up a file descriptor choice here
5204 * with redirect_opt_num(), but bash doesn't do it.
5205 * "echo foo 2| cat" yields "foo 2". */
5210 #if ENABLE_HUSH_CASE
5211 /* "case... in [(]word)..." - skip '(' */
5212 if (ctx.ctx_res_w == RES_MATCH
5213 && ctx.command->argv == NULL /* not (word|(... */
5214 && dest.length == 0 /* not word(... */
5215 && dest.has_quoted_part == 0 /* not ""(... */
5221 if (parse_group(&dest, &ctx, input, ch) != 0) {
5226 #if ENABLE_HUSH_CASE
5227 if (ctx.ctx_res_w == RES_MATCH)
5231 /* proper use of this character is caught by end_trigger:
5232 * if we see {, we call parse_group(..., end_trigger='}')
5233 * and it will match } earlier (not here). */
5234 syntax_error_unexpected_ch(ch);
5235 G.last_exitcode = 2;
5239 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5244 G.last_exitcode = 1;
5247 struct parse_context *pctx;
5248 IF_HAS_KEYWORDS(struct parse_context *p2;)
5250 /* Clean up allocated tree.
5251 * Sample for finding leaks on syntax error recovery path.
5252 * Run it from interactive shell, watch pmap `pidof hush`.
5253 * while if false; then false; fi; do break; fi
5254 * Samples to catch leaks at execution:
5255 * while if (true | { true;}); then echo ok; fi; do break; done
5256 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5260 /* Update pipe/command counts,
5261 * otherwise freeing may miss some */
5262 done_pipe(pctx, PIPE_SEQ);
5263 debug_printf_clean("freeing list %p from ctx %p\n",
5264 pctx->list_head, pctx);
5265 debug_print_tree(pctx->list_head, 0);
5266 free_pipe_list(pctx->list_head);
5267 debug_printf_clean("freed list %p\n", pctx->list_head);
5269 o_free_unsafe(&pctx->as_string);
5271 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5275 IF_HAS_KEYWORDS(pctx = p2;)
5276 } while (HAS_KEYWORDS && pctx);
5289 /*** Execution routines ***/
5291 /* Expansion can recurse, need forward decls: */
5292 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5293 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5294 #define expand_string_to_string(str, do_unbackslash) \
5295 expand_string_to_string(str)
5297 static char *expand_string_to_string(const char *str, int do_unbackslash);
5298 #if ENABLE_HUSH_TICK
5299 static int process_command_subs(o_string *dest, const char *s);
5302 /* expand_strvec_to_strvec() takes a list of strings, expands
5303 * all variable references within and returns a pointer to
5304 * a list of expanded strings, possibly with larger number
5305 * of strings. (Think VAR="a b"; echo $VAR).
5306 * This new list is allocated as a single malloc block.
5307 * NULL-terminated list of char* pointers is at the beginning of it,
5308 * followed by strings themselves.
5309 * Caller can deallocate entire list by single free(list). */
5311 /* A horde of its helpers come first: */
5313 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5315 while (--len >= 0) {
5318 #if ENABLE_HUSH_BRACE_EXPANSION
5319 if (c == '{' || c == '}') {
5320 /* { -> \{, } -> \} */
5322 /* And now we want to add { or } and continue:
5325 * luckily, just falling through achieves this.
5331 /* \z -> \\\z; \<eol> -> \\<eol> */
5336 o_addchr(o, *str++);
5342 /* Store given string, finalizing the word and starting new one whenever
5343 * we encounter IFS char(s). This is used for expanding variable values.
5344 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5345 * Return in *ended_with_ifs:
5346 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5348 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5350 int last_is_ifs = 0;
5355 if (!*str) /* EOL - do not finalize word */
5357 word_len = strcspn(str, G.ifs);
5359 /* We have WORD_LEN leading non-IFS chars */
5360 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5361 o_addblock(output, str, word_len);
5363 /* Protect backslashes against globbing up :)
5364 * Example: "v='\*'; echo b$v" prints "b\*"
5365 * (and does not try to glob on "*")
5367 o_addblock_duplicate_backslash(output, str, word_len);
5368 /*/ Why can't we do it easier? */
5369 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5370 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5374 if (!*str) /* EOL - do not finalize word */
5378 /* We know str here points to at least one IFS char */
5380 str += strspn(str, G.ifs); /* skip IFS chars */
5381 if (!*str) /* EOL - do not finalize word */
5384 /* Start new word... but not always! */
5385 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5386 if (output->has_quoted_part
5387 /* Case "v=' a'; echo $v":
5388 * here nothing precedes the space in $v expansion,
5389 * therefore we should not finish the word
5390 * (IOW: if there *is* word to finalize, only then do it):
5392 || (n > 0 && output->data[output->length - 1])
5394 o_addchr(output, '\0');
5395 debug_print_list("expand_on_ifs", output, n);
5396 n = o_save_ptr(output, n);
5401 *ended_with_ifs = last_is_ifs;
5402 debug_print_list("expand_on_ifs[1]", output, n);
5406 /* Helper to expand $((...)) and heredoc body. These act as if
5407 * they are in double quotes, with the exception that they are not :).
5408 * Just the rules are similar: "expand only $var and `cmd`"
5410 * Returns malloced string.
5411 * As an optimization, we return NULL if expansion is not needed.
5413 #if !BASH_PATTERN_SUBST
5414 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5415 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5416 encode_then_expand_string(str)
5418 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5420 #if !BASH_PATTERN_SUBST
5421 const int do_unbackslash = 1;
5424 struct in_str input;
5425 o_string dest = NULL_O_STRING;
5427 if (!strchr(str, '$')
5428 && !strchr(str, '\\')
5429 #if ENABLE_HUSH_TICK
5430 && !strchr(str, '`')
5436 /* We need to expand. Example:
5437 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5439 setup_string_in_str(&input, str);
5440 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5441 //TODO: error check (encode_string returns 0 on error)?
5442 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5443 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5444 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5445 o_free_unsafe(&dest);
5449 #if ENABLE_FEATURE_SH_MATH
5450 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5452 arith_state_t math_state;
5456 math_state.lookupvar = get_local_var_value;
5457 math_state.setvar = set_local_var_from_halves;
5458 //math_state.endofname = endofname;
5459 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5460 res = arith(&math_state, exp_str ? exp_str : arg);
5463 *errmsg_p = math_state.errmsg;
5464 if (math_state.errmsg)
5465 die_if_script(math_state.errmsg);
5470 #if BASH_PATTERN_SUBST
5471 /* ${var/[/]pattern[/repl]} helpers */
5472 static char *strstr_pattern(char *val, const char *pattern, int *size)
5475 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5476 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5483 /* Optimization: if "*pat" did not match the start of "string",
5484 * we know that "tring", "ring" etc will not match too:
5486 if (pattern[0] == '*')
5491 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5493 char *result = NULL;
5494 unsigned res_len = 0;
5495 unsigned repl_len = strlen(repl);
5499 char *s = strstr_pattern(val, pattern, &size);
5503 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5504 memcpy(result + res_len, val, s - val);
5506 strcpy(result + res_len, repl);
5507 res_len += repl_len;
5508 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5514 if (val[0] && result) {
5515 result = xrealloc(result, res_len + strlen(val) + 1);
5516 strcpy(result + res_len, val);
5517 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5519 debug_printf_varexp("result:'%s'\n", result);
5522 #endif /* BASH_PATTERN_SUBST */
5525 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5527 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5529 const char *val = NULL;
5530 char *to_be_freed = NULL;
5535 char exp_save = exp_save; /* for compiler */
5536 char *exp_saveptr; /* points to expansion operator */
5537 char *exp_word = exp_word; /* for compiler */
5540 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5542 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5544 first_char = arg[0] = arg0 & 0x7f;
5547 if (first_char == '#' /* ${#... */
5548 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5550 /* It must be length operator: ${#var} */
5554 /* Maybe handle parameter expansion */
5555 if (exp_saveptr /* if 2nd char is one of expansion operators */
5556 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5558 /* ${?:0}, ${#[:]%0} etc */
5559 exp_saveptr = var + 1;
5561 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5562 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5564 exp_op = exp_save = *exp_saveptr;
5566 exp_word = exp_saveptr + 1;
5567 if (exp_op == ':') {
5568 exp_op = *exp_word++;
5569 //TODO: try ${var:} and ${var:bogus} in non-bash config
5571 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5573 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5578 *exp_saveptr = '\0';
5579 } /* else: it's not an expansion op, but bare ${var} */
5582 /* Look up the variable in question */
5583 if (isdigit(var[0])) {
5584 /* parse_dollar should have vetted var for us */
5585 int n = xatoi_positive(var);
5586 if (n < G.global_argc)
5587 val = G.global_argv[n];
5588 /* else val remains NULL: $N with too big N */
5592 val = utoa(G.root_pid);
5594 case '!': /* bg pid */
5595 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5597 case '?': /* exitcode */
5598 val = utoa(G.last_exitcode);
5600 case '#': /* argc */
5601 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5604 val = get_local_var_value(var);
5608 /* Handle any expansions */
5609 if (exp_op == 'L') {
5610 reinit_unicode_for_hush();
5611 debug_printf_expand("expand: length(%s)=", val);
5612 val = utoa(val ? unicode_strlen(val) : 0);
5613 debug_printf_expand("%s\n", val);
5614 } else if (exp_op) {
5615 if (exp_op == '%' || exp_op == '#') {
5616 /* Standard-mandated substring removal ops:
5617 * ${parameter%word} - remove smallest suffix pattern
5618 * ${parameter%%word} - remove largest suffix pattern
5619 * ${parameter#word} - remove smallest prefix pattern
5620 * ${parameter##word} - remove largest prefix pattern
5622 * Word is expanded to produce a glob pattern.
5623 * Then var's value is matched to it and matching part removed.
5625 if (val && val[0]) {
5629 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5630 if (exp_op == *exp_word) /* ## or %% */
5632 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5634 exp_word = exp_exp_word;
5635 /* HACK ALERT. We depend here on the fact that
5636 * G.global_argv and results of utoa and get_local_var_value
5637 * are actually in writable memory:
5638 * scan_and_match momentarily stores NULs there. */
5640 loc = scan_and_match(t, exp_word, scan_flags);
5641 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5642 // exp_op, t, exp_word, loc);
5644 if (loc) { /* match was found */
5645 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5646 val = loc; /* take right part */
5648 val = to_be_freed = xstrndup(val, loc - val); /* left */
5652 #if BASH_PATTERN_SUBST
5653 else if (exp_op == '/' || exp_op == '\\') {
5654 /* It's ${var/[/]pattern[/repl]} thing.
5655 * Note that in encoded form it has TWO parts:
5656 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5657 * and if // is used, it is encoded as \:
5658 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5660 /* Empty variable always gives nothing: */
5661 // "v=''; echo ${v/*/w}" prints "", not "w"
5662 if (val && val[0]) {
5663 /* pattern uses non-standard expansion.
5664 * repl should be unbackslashed and globbed
5665 * by the usual expansion rules:
5667 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5668 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5669 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5670 * v='a bz'; echo ${v/a*z/\z} prints "z"
5671 * (note that a*z _pattern_ is never globbed!)
5673 char *pattern, *repl, *t;
5674 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5676 pattern = xstrdup(exp_word);
5677 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5678 *p++ = SPECIAL_VAR_SYMBOL;
5680 p = strchr(p, SPECIAL_VAR_SYMBOL);
5682 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5683 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5684 /* HACK ALERT. We depend here on the fact that
5685 * G.global_argv and results of utoa and get_local_var_value
5686 * are actually in writable memory:
5687 * replace_pattern momentarily stores NULs there. */
5689 to_be_freed = replace_pattern(t,
5691 (repl ? repl : exp_word),
5693 if (to_be_freed) /* at least one replace happened */
5699 #endif /* BASH_PATTERN_SUBST */
5700 else if (exp_op == ':') {
5701 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5702 /* It's ${var:N[:M]} bashism.
5703 * Note that in encoded form it has TWO parts:
5704 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5709 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5712 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5713 *p++ = SPECIAL_VAR_SYMBOL;
5715 p = strchr(p, SPECIAL_VAR_SYMBOL);
5717 len = expand_and_evaluate_arith(exp_word, &errmsg);
5720 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5722 /* negative beg counts from the end */
5723 beg = (arith_t)strlen(val) + beg;
5724 if (beg < 0) /* ${v: -999999} is "" */
5727 debug_printf_varexp("from val:'%s'\n", val);
5729 /* in bash, len=-n means strlen()-n */
5730 len = (arith_t)strlen(val) - beg + len;
5731 if (len < 0) /* bash compat */
5732 die_if_script("%s: substring expression < 0", var);
5734 if (len <= 0 || !val || beg >= strlen(val)) {
5738 /* Paranoia. What if user entered 9999999999999
5739 * which fits in arith_t but not int? */
5742 val = to_be_freed = xstrndup(val + beg, len);
5744 debug_printf_varexp("val:'%s'\n", val);
5745 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5746 die_if_script("malformed ${%s:...}", var);
5749 } else { /* one of "-=+?" */
5750 /* Standard-mandated substitution ops:
5751 * ${var?word} - indicate error if unset
5752 * If var is unset, word (or a message indicating it is unset
5753 * if word is null) is written to standard error
5754 * and the shell exits with a non-zero exit status.
5755 * Otherwise, the value of var is substituted.
5756 * ${var-word} - use default value
5757 * If var is unset, word is substituted.
5758 * ${var=word} - assign and use default value
5759 * If var is unset, word is assigned to var.
5760 * In all cases, final value of var is substituted.
5761 * ${var+word} - use alternative value
5762 * If var is unset, null is substituted.
5763 * Otherwise, word is substituted.
5765 * Word is subjected to tilde expansion, parameter expansion,
5766 * command substitution, and arithmetic expansion.
5767 * If word is not needed, it is not expanded.
5769 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5770 * but also treat null var as if it is unset.
5772 int use_word = (!val || ((exp_save == ':') && !val[0]));
5774 use_word = !use_word;
5775 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5776 (exp_save == ':') ? "true" : "false", use_word);
5778 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5780 exp_word = to_be_freed;
5781 if (exp_op == '?') {
5782 /* mimic bash message */
5783 die_if_script("%s: %s",
5785 exp_word[0] ? exp_word : "parameter null or not set"
5787 //TODO: how interactive bash aborts expansion mid-command?
5792 if (exp_op == '=') {
5793 /* ${var=[word]} or ${var:=[word]} */
5794 if (isdigit(var[0]) || var[0] == '#') {
5795 /* mimic bash message */
5796 die_if_script("$%s: cannot assign in this way", var);
5799 char *new_var = xasprintf("%s=%s", var, val);
5800 set_local_var(new_var, /*flag:*/ 0);
5804 } /* one of "-=+?" */
5806 *exp_saveptr = exp_save;
5812 *to_be_freed_pp = to_be_freed;
5816 /* Expand all variable references in given string, adding words to list[]
5817 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5818 * to be filled). This routine is extremely tricky: has to deal with
5819 * variables/parameters with whitespace, $* and $@, and constructs like
5820 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5821 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5823 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5824 * expansion of right-hand side of assignment == 1-element expand.
5826 char cant_be_null = 0; /* only bit 0x80 matters */
5827 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5830 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5831 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5832 debug_print_list("expand_vars_to_list", output, n);
5833 n = o_save_ptr(output, n);
5834 debug_print_list("expand_vars_to_list[0]", output, n);
5836 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5838 char *to_be_freed = NULL;
5839 const char *val = NULL;
5840 #if ENABLE_HUSH_TICK
5841 o_string subst_result = NULL_O_STRING;
5843 #if ENABLE_FEATURE_SH_MATH
5844 char arith_buf[sizeof(arith_t)*3 + 2];
5848 o_addchr(output, '\0');
5849 n = o_save_ptr(output, n);
5853 o_addblock(output, arg, p - arg);
5854 debug_print_list("expand_vars_to_list[1]", output, n);
5856 p = strchr(p, SPECIAL_VAR_SYMBOL);
5858 /* Fetch special var name (if it is indeed one of them)
5859 * and quote bit, force the bit on if singleword expansion -
5860 * important for not getting v=$@ expand to many words. */
5861 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5863 /* Is this variable quoted and thus expansion can't be null?
5864 * "$@" is special. Even if quoted, it can still
5865 * expand to nothing (not even an empty string),
5866 * thus it is excluded. */
5867 if ((first_ch & 0x7f) != '@')
5868 cant_be_null |= first_ch;
5870 switch (first_ch & 0x7f) {
5871 /* Highest bit in first_ch indicates that var is double-quoted */
5875 if (!G.global_argv[1])
5878 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5879 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5880 while (G.global_argv[i]) {
5881 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5882 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5883 if (G.global_argv[i++][0] && G.global_argv[i]) {
5884 /* this argv[] is not empty and not last:
5885 * put terminating NUL, start new word */
5886 o_addchr(output, '\0');
5887 debug_print_list("expand_vars_to_list[2]", output, n);
5888 n = o_save_ptr(output, n);
5889 debug_print_list("expand_vars_to_list[3]", output, n);
5893 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5894 * and in this case should treat it like '$*' - see 'else...' below */
5895 if (first_ch == ('@'|0x80) /* quoted $@ */
5896 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5899 o_addQstr(output, G.global_argv[i]);
5900 if (++i >= G.global_argc)
5902 o_addchr(output, '\0');
5903 debug_print_list("expand_vars_to_list[4]", output, n);
5904 n = o_save_ptr(output, n);
5906 } else { /* quoted $* (or v="$@" case): add as one word */
5908 o_addQstr(output, G.global_argv[i]);
5909 if (!G.global_argv[++i])
5912 o_addchr(output, G.ifs[0]);
5914 output->has_quoted_part = 1;
5918 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5919 /* "Empty variable", used to make "" etc to not disappear */
5920 output->has_quoted_part = 1;
5922 cant_be_null = 0x80;
5924 #if ENABLE_HUSH_TICK
5925 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5926 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5928 /* Can't just stuff it into output o_string,
5929 * expanded result may need to be globbed
5931 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5932 G.last_exitcode = process_command_subs(&subst_result, arg);
5933 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5934 val = subst_result.data;
5937 #if ENABLE_FEATURE_SH_MATH
5938 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5941 arg++; /* skip '+' */
5942 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5943 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5944 res = expand_and_evaluate_arith(arg, NULL);
5945 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5946 sprintf(arith_buf, ARITH_FMT, res);
5952 val = expand_one_var(&to_be_freed, arg, &p);
5953 IF_HUSH_TICK(store_val:)
5954 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5955 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5956 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5957 if (val && val[0]) {
5958 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5961 } else { /* quoted $VAR, val will be appended below */
5962 output->has_quoted_part = 1;
5963 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5964 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5967 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5969 if (val && val[0]) {
5970 o_addQstr(output, val);
5974 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5975 * Do the check to avoid writing to a const string. */
5976 if (*p != SPECIAL_VAR_SYMBOL)
5977 *p = SPECIAL_VAR_SYMBOL;
5979 #if ENABLE_HUSH_TICK
5980 o_free(&subst_result);
5983 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5987 o_addchr(output, '\0');
5988 n = o_save_ptr(output, n);
5990 debug_print_list("expand_vars_to_list[a]", output, n);
5991 /* this part is literal, and it was already pre-quoted
5992 * if needed (much earlier), do not use o_addQstr here! */
5993 o_addstr_with_NUL(output, arg);
5994 debug_print_list("expand_vars_to_list[b]", output, n);
5995 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5996 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5999 /* allow to reuse list[n] later without re-growth */
6000 output->has_empty_slot = 1;
6002 o_addchr(output, '\0');
6008 static char **expand_variables(char **argv, unsigned expflags)
6012 o_string output = NULL_O_STRING;
6014 output.o_expflags = expflags;
6018 n = expand_vars_to_list(&output, n, *argv);
6021 debug_print_list("expand_variables", &output, n);
6023 /* output.data (malloced in one block) gets returned in "list" */
6024 list = o_finalize_list(&output, n);
6025 debug_print_strings("expand_variables[1]", list);
6029 static char **expand_strvec_to_strvec(char **argv)
6031 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6035 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6037 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6041 /* Used for expansion of right hand of assignments,
6042 * $((...)), heredocs, variable espansion parts.
6044 * NB: should NOT do globbing!
6045 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6047 static char *expand_string_to_string(const char *str, int do_unbackslash)
6049 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6050 const int do_unbackslash = 1;
6052 char *argv[2], **list;
6054 debug_printf_expand("string_to_string<='%s'\n", str);
6055 /* This is generally an optimization, but it also
6056 * handles "", which otherwise trips over !list[0] check below.
6057 * (is this ever happens that we actually get str="" here?)
6059 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6060 //TODO: Can use on strings with \ too, just unbackslash() them?
6061 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6062 return xstrdup(str);
6065 argv[0] = (char*)str;
6067 list = expand_variables(argv, do_unbackslash
6068 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6069 : EXP_FLAG_SINGLEWORD
6072 if (!list[0] || list[1])
6073 bb_error_msg_and_die("BUG in varexp2");
6074 /* actually, just move string 2*sizeof(char*) bytes back */
6075 overlapping_strcpy((char*)list, list[0]);
6077 unbackslash((char*)list);
6078 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6082 /* Used for "eval" builtin and case string */
6083 static char* expand_strvec_to_string(char **argv)
6087 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6088 /* Convert all NULs to spaces */
6093 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6094 bb_error_msg_and_die("BUG in varexp3");
6095 /* bash uses ' ' regardless of $IFS contents */
6100 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6101 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6105 static char **expand_assignments(char **argv, int count)
6110 G.expanded_assignments = p = NULL;
6111 /* Expand assignments into one string each */
6112 for (i = 0; i < count; i++) {
6113 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6115 G.expanded_assignments = NULL;
6120 static void switch_off_special_sigs(unsigned mask)
6123 while ((mask >>= 1) != 0) {
6127 #if ENABLE_HUSH_TRAP
6129 if (G_traps[sig] && !G_traps[sig][0])
6130 /* trap is '', has to remain SIG_IGN */
6133 G_traps[sig] = NULL;
6136 /* We are here only if no trap or trap was not '' */
6137 install_sighandler(sig, SIG_DFL);
6143 void re_execute_shell(char ***to_free, const char *s,
6144 char *g_argv0, char **g_argv,
6145 char **builtin_argv) NORETURN;
6147 static void reset_traps_to_defaults(void)
6149 /* This function is always called in a child shell
6150 * after fork (not vfork, NOMMU doesn't use this function).
6152 IF_HUSH_TRAP(unsigned sig;)
6155 /* Child shells are not interactive.
6156 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6157 * Testcase: (while :; do :; done) + ^Z should background.
6158 * Same goes for SIGTERM, SIGHUP, SIGINT.
6160 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6161 if (!G_traps && !mask)
6162 return; /* already no traps and no special sigs */
6164 /* Switch off special sigs */
6165 switch_off_special_sigs(mask);
6166 # if ENABLE_HUSH_JOB
6167 G_fatal_sig_mask = 0;
6169 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6170 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6171 * remain set in G.special_sig_mask */
6173 # if ENABLE_HUSH_TRAP
6177 /* Reset all sigs to default except ones with empty traps */
6178 for (sig = 0; sig < NSIG; sig++) {
6180 continue; /* no trap: nothing to do */
6181 if (!G_traps[sig][0])
6182 continue; /* empty trap: has to remain SIG_IGN */
6183 /* sig has non-empty trap, reset it: */
6185 G_traps[sig] = NULL;
6186 /* There is no signal for trap 0 (EXIT) */
6189 install_sighandler(sig, pick_sighandler(sig));
6196 static void re_execute_shell(char ***to_free, const char *s,
6197 char *g_argv0, char **g_argv,
6198 char **builtin_argv) NORETURN;
6199 static void re_execute_shell(char ***to_free, const char *s,
6200 char *g_argv0, char **g_argv,
6201 char **builtin_argv)
6203 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6204 /* delims + 2 * (number of bytes in printed hex numbers) */
6205 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6206 char *heredoc_argv[4];
6207 struct variable *cur;
6208 # if ENABLE_HUSH_FUNCTIONS
6209 struct function *funcp;
6213 unsigned long long empty_trap_mask;
6215 if (!g_argv0) { /* heredoc */
6216 argv = heredoc_argv;
6217 argv[0] = (char *) G.argv0_for_re_execing;
6218 argv[1] = (char *) "-<";
6219 argv[2] = (char *) s;
6221 pp = &argv[3]; /* used as pointer to empty environment */
6227 if (pp) while (*pp++)
6230 empty_trap_mask = 0;
6233 for (sig = 1; sig < NSIG; sig++) {
6234 if (G_traps[sig] && !G_traps[sig][0])
6235 empty_trap_mask |= 1LL << sig;
6239 sprintf(param_buf, NOMMU_HACK_FMT
6240 , (unsigned) G.root_pid
6241 , (unsigned) G.root_ppid
6242 , (unsigned) G.last_bg_pid
6243 , (unsigned) G.last_exitcode
6246 IF_HUSH_LOOPS(, G.depth_of_loop)
6248 # undef NOMMU_HACK_FMT
6249 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6250 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6253 for (cur = G.top_var; cur; cur = cur->next) {
6254 if (!cur->flg_export || cur->flg_read_only)
6257 # if ENABLE_HUSH_FUNCTIONS
6258 for (funcp = G.top_func; funcp; funcp = funcp->next)
6264 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6265 *pp++ = (char *) G.argv0_for_re_execing;
6267 for (cur = G.top_var; cur; cur = cur->next) {
6268 if (strcmp(cur->varstr, hush_version_str) == 0)
6270 if (cur->flg_read_only) {
6271 *pp++ = (char *) "-R";
6272 *pp++ = cur->varstr;
6273 } else if (!cur->flg_export) {
6274 *pp++ = (char *) "-V";
6275 *pp++ = cur->varstr;
6278 # if ENABLE_HUSH_FUNCTIONS
6279 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6280 *pp++ = (char *) "-F";
6281 *pp++ = funcp->name;
6282 *pp++ = funcp->body_as_string;
6285 /* We can pass activated traps here. Say, -Tnn:trap_string
6287 * However, POSIX says that subshells reset signals with traps
6289 * I tested bash-3.2 and it not only does that with true subshells
6290 * of the form ( list ), but with any forked children shells.
6291 * I set trap "echo W" WINCH; and then tried:
6293 * { echo 1; sleep 20; echo 2; } &
6294 * while true; do echo 1; sleep 20; echo 2; break; done &
6295 * true | { echo 1; sleep 20; echo 2; } | cat
6297 * In all these cases sending SIGWINCH to the child shell
6298 * did not run the trap. If I add trap "echo V" WINCH;
6299 * _inside_ group (just before echo 1), it works.
6301 * I conclude it means we don't need to pass active traps here.
6303 *pp++ = (char *) "-c";
6306 while (*++builtin_argv)
6307 *pp++ = *builtin_argv;
6308 *pp++ = (char *) "";
6313 /* *pp = NULL; - is already there */
6317 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6318 /* Don't propagate SIG_IGN to the child */
6319 if (SPECIAL_JOBSTOP_SIGS != 0)
6320 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6321 execve(bb_busybox_exec_path, argv, pp);
6322 /* Fallback. Useful for init=/bin/hush usage etc */
6323 if (argv[0][0] == '/')
6324 execve(argv[0], argv, pp);
6325 xfunc_error_retval = 127;
6326 bb_error_msg_and_die("can't re-execute the shell");
6328 #endif /* !BB_MMU */
6331 static int run_and_free_list(struct pipe *pi);
6333 /* Executing from string: eval, sh -c '...'
6334 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6335 * end_trigger controls how often we stop parsing
6336 * NUL: parse all, execute, return
6337 * ';': parse till ';' or newline, execute, repeat till EOF
6339 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6341 /* Why we need empty flag?
6342 * An obscure corner case "false; ``; echo $?":
6343 * empty command in `` should still set $? to 0.
6344 * But we can't just set $? to 0 at the start,
6345 * this breaks "false; echo `echo $?`" case.
6349 struct pipe *pipe_list;
6351 #if ENABLE_HUSH_INTERACTIVE
6352 if (end_trigger == ';')
6353 inp->promptmode = 0; /* PS1 */
6355 pipe_list = parse_stream(NULL, inp, end_trigger);
6356 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6357 /* If we are in "big" script
6358 * (not in `cmd` or something similar)...
6360 if (pipe_list == ERR_PTR && end_trigger == ';') {
6361 /* Discard cached input (rest of line) */
6362 int ch = inp->last_char;
6363 while (ch != EOF && ch != '\n') {
6364 //bb_error_msg("Discarded:'%c'", ch);
6369 /* This stream isn't empty */
6373 if (!pipe_list && empty)
6374 G.last_exitcode = 0;
6377 debug_print_tree(pipe_list, 0);
6378 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6379 run_and_free_list(pipe_list);
6381 if (G_flag_return_in_progress == 1)
6386 static void parse_and_run_string(const char *s)
6388 struct in_str input;
6389 setup_string_in_str(&input, s);
6390 parse_and_run_stream(&input, '\0');
6393 static void parse_and_run_file(FILE *f)
6395 struct in_str input;
6396 setup_file_in_str(&input, f);
6397 parse_and_run_stream(&input, ';');
6400 #if ENABLE_HUSH_TICK
6401 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6406 char **to_free = NULL;
6410 pid = BB_MMU ? xfork() : xvfork();
6411 if (pid == 0) { /* child */
6412 disable_restore_tty_pgrp_on_exit();
6413 /* Process substitution is not considered to be usual
6414 * 'command execution'.
6415 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6422 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6423 close(channel[0]); /* NB: close _first_, then move fd! */
6424 xmove_fd(channel[1], 1);
6425 /* Prevent it from trying to handle ctrl-z etc */
6426 IF_HUSH_JOB(G.run_list_level = 1;)
6427 # if ENABLE_HUSH_TRAP
6428 /* Awful hack for `trap` or $(trap).
6430 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6431 * contains an example where "trap" is executed in a subshell:
6433 * save_traps=$(trap)
6435 * eval "$save_traps"
6437 * Standard does not say that "trap" in subshell shall print
6438 * parent shell's traps. It only says that its output
6439 * must have suitable form, but then, in the above example
6440 * (which is not supposed to be normative), it implies that.
6442 * bash (and probably other shell) does implement it
6443 * (traps are reset to defaults, but "trap" still shows them),
6444 * but as a result, "trap" logic is hopelessly messed up:
6447 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6448 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6449 * # true | trap <--- trap is in subshell - no output (ditto)
6450 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6451 * trap -- 'echo Ho' SIGWINCH
6452 * # echo `(trap)` <--- in subshell in subshell - output
6453 * trap -- 'echo Ho' SIGWINCH
6454 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6455 * trap -- 'echo Ho' SIGWINCH
6457 * The rules when to forget and when to not forget traps
6458 * get really complex and nonsensical.
6460 * Our solution: ONLY bare $(trap) or `trap` is special.
6462 s = skip_whitespace(s);
6463 if (is_prefixed_with(s, "trap")
6464 && skip_whitespace(s + 4)[0] == '\0'
6466 static const char *const argv[] = { NULL, NULL };
6467 builtin_trap((char**)argv);
6468 fflush_all(); /* important */
6473 reset_traps_to_defaults();
6474 parse_and_run_string(s);
6475 _exit(G.last_exitcode);
6477 /* We re-execute after vfork on NOMMU. This makes this script safe:
6478 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6479 * huge=`cat BIG` # was blocking here forever
6482 re_execute_shell(&to_free,
6492 # if ENABLE_HUSH_FAST
6494 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6495 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6496 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6498 enable_restore_tty_pgrp_on_exit();
6503 return remember_FILE(xfdopen_for_read(channel[0]));
6506 /* Return code is exit status of the process that is run. */
6507 static int process_command_subs(o_string *dest, const char *s)
6510 struct in_str pipe_str;
6512 int status, ch, eol_cnt;
6514 fp = generate_stream_from_string(s, &pid);
6516 /* Now send results of command back into original context */
6517 setup_file_in_str(&pipe_str, fp);
6519 while ((ch = i_getch(&pipe_str)) != EOF) {
6525 o_addchr(dest, '\n');
6528 o_addQchr(dest, ch);
6531 debug_printf("done reading from `cmd` pipe, closing it\n");
6532 fclose_and_forget(fp);
6533 /* We need to extract exitcode. Test case
6534 * "true; echo `sleep 1; false` $?"
6536 safe_waitpid(pid, &status, 0);
6537 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6538 return WEXITSTATUS(status);
6540 #endif /* ENABLE_HUSH_TICK */
6543 static void setup_heredoc(struct redir_struct *redir)
6545 struct fd_pair pair;
6548 /* the _body_ of heredoc (misleading field name) */
6549 const char *heredoc = redir->rd_filename;
6556 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6557 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6561 len = strlen(heredoc);
6563 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6565 xmove_fd(pair.rd, redir->rd_fd);
6567 /* Try writing without forking. Newer kernels have
6568 * dynamically growing pipes. Must use non-blocking write! */
6571 written = write(pair.wr, heredoc, len);
6582 ndelay_off(pair.wr);
6584 /* Okay, pipe buffer was not big enough */
6585 /* Note: we must not create a stray child (bastard? :)
6586 * for the unsuspecting parent process. Child creates a grandchild
6587 * and exits before parent execs the process which consumes heredoc
6588 * (that exec happens after we return from this function) */
6595 disable_restore_tty_pgrp_on_exit();
6596 pid = BB_MMU ? xfork() : xvfork();
6600 close(redir->rd_fd); /* read side of the pipe */
6602 full_write(pair.wr, heredoc, len); /* may loop or block */
6605 /* Delegate blocking writes to another process */
6606 xmove_fd(pair.wr, STDOUT_FILENO);
6607 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6611 #if ENABLE_HUSH_FAST
6613 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6615 enable_restore_tty_pgrp_on_exit();
6621 wait(NULL); /* wait till child has died */
6627 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6628 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6631 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6635 if (sq) while (sq[i].orig_fd >= 0) {
6636 /* If we collide with an already moved fd... */
6637 if (fd == sq[i].moved_to) {
6638 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6639 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6640 if (sq[i].moved_to < 0) /* what? */
6644 if (fd == sq[i].orig_fd) {
6645 /* Example: echo Hello >/dev/null 1>&2 */
6646 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6652 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6654 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6655 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6656 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6657 if (sq[i].moved_to < 0 && errno != EBADF)
6659 sq[i+1].orig_fd = -1; /* end marker */
6663 /* fd: redirect wants this fd to be used (e.g. 3>file).
6664 * Move all conflicting internally used fds,
6665 * and remember them so that we can restore them later.
6667 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6669 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6672 #if ENABLE_HUSH_INTERACTIVE
6673 if (fd != 0 && fd == G.interactive_fd) {
6674 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6675 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6676 return 1; /* "we closed fd" */
6679 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6680 * (1) Redirect in a forked child. No need to save FILEs' fds,
6681 * we aren't going to use them anymore, ok to trash.
6682 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6683 * but how are we doing to restore them?
6684 * "fileno(fd) = new_fd" can't be done.
6689 /* If this one of script's fds? */
6690 if (save_FILEs_on_redirect(fd, avoid_fd))
6691 return 1; /* yes. "we closed fd" */
6693 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6694 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6695 return 0; /* "we did not close fd" */
6698 static void restore_redirects(struct squirrel *sq)
6703 while (sq[i].orig_fd >= 0) {
6704 if (sq[i].moved_to >= 0) {
6705 /* We simply die on error */
6706 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6707 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6709 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6710 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6711 close(sq[i].orig_fd);
6718 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6720 restore_redirected_FILEs();
6723 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6724 * and stderr if they are redirected. */
6725 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6728 struct redir_struct *redir;
6730 for (redir = prog->redirects; redir; redir = redir->next) {
6731 if (redir->rd_type == REDIRECT_HEREDOC2) {
6732 /* "rd_fd<<HERE" case */
6733 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6734 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6736 debug_printf_parse("set heredoc '%s'\n",
6737 redir->rd_filename);
6738 setup_heredoc(redir);
6742 if (redir->rd_dup == REDIRFD_TO_FILE) {
6743 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6745 if (redir->rd_filename == NULL) {
6748 * "cmd >" (no filename)
6749 * "cmd > <file" (2nd redirect starts too early)
6751 die_if_script("syntax error: %s", "invalid redirect");
6754 mode = redir_table[redir->rd_type].mode;
6755 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6756 openfd = open_or_warn(p, mode);
6759 /* Error message from open_or_warn can be lost
6760 * if stderr has been redirected, but bash
6761 * and ash both lose it as well
6762 * (though zsh doesn't!)
6767 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6768 openfd = redir->rd_dup;
6771 if (openfd != redir->rd_fd) {
6772 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6773 if (openfd == REDIRFD_CLOSE) {
6774 /* "rd_fd >&-" means "close me" */
6776 /* ^^^ optimization: saving may already
6777 * have closed it. If not... */
6778 close(redir->rd_fd);
6781 xdup2(openfd, redir->rd_fd);
6782 if (redir->rd_dup == REDIRFD_TO_FILE)
6783 /* "rd_fd > FILE" */
6785 /* else: "rd_fd > rd_dup" */
6792 static char *find_in_path(const char *arg)
6795 const char *PATH = get_local_var_value("PATH");
6801 const char *end = strchrnul(PATH, ':');
6802 int sz = end - PATH; /* must be int! */
6806 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6808 /* We have xxx::yyyy in $PATH,
6809 * it means "use current dir" */
6812 if (access(ret, F_OK) == 0)
6825 static const struct built_in_command *find_builtin_helper(const char *name,
6826 const struct built_in_command *x,
6827 const struct built_in_command *end)
6830 if (strcmp(name, x->b_cmd) != 0) {
6834 debug_printf_exec("found builtin '%s'\n", name);
6839 static const struct built_in_command *find_builtin1(const char *name)
6841 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6843 static const struct built_in_command *find_builtin(const char *name)
6845 const struct built_in_command *x = find_builtin1(name);
6848 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6851 #if ENABLE_HUSH_FUNCTIONS
6852 static struct function **find_function_slot(const char *name)
6854 struct function **funcpp = &G.top_func;
6856 if (strcmp(name, (*funcpp)->name) == 0) {
6859 funcpp = &(*funcpp)->next;
6864 static const struct function *find_function(const char *name)
6866 const struct function *funcp = *find_function_slot(name);
6868 debug_printf_exec("found function '%s'\n", name);
6872 /* Note: takes ownership on name ptr */
6873 static struct function *new_function(char *name)
6875 struct function **funcpp = find_function_slot(name);
6876 struct function *funcp = *funcpp;
6878 if (funcp != NULL) {
6879 struct command *cmd = funcp->parent_cmd;
6880 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6882 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6884 /* Note: if !funcp->body, do not free body_as_string!
6885 * This is a special case of "-F name body" function:
6886 * body_as_string was not malloced! */
6888 free_pipe_list(funcp->body);
6890 free(funcp->body_as_string);
6894 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6895 cmd->argv[0] = funcp->name;
6896 cmd->group = funcp->body;
6898 cmd->group_as_string = funcp->body_as_string;
6902 debug_printf_exec("remembering new function '%s'\n", name);
6903 funcp = *funcpp = xzalloc(sizeof(*funcp));
6904 /*funcp->next = NULL;*/
6911 # if ENABLE_HUSH_UNSET
6912 static void unset_func(const char *name)
6914 struct function **funcpp = find_function_slot(name);
6915 struct function *funcp = *funcpp;
6917 if (funcp != NULL) {
6918 debug_printf_exec("freeing function '%s'\n", funcp->name);
6919 *funcpp = funcp->next;
6920 /* funcp is unlinked now, deleting it.
6921 * Note: if !funcp->body, the function was created by
6922 * "-F name body", do not free ->body_as_string
6923 * and ->name as they were not malloced. */
6925 free_pipe_list(funcp->body);
6928 free(funcp->body_as_string);
6937 #define exec_function(to_free, funcp, argv) \
6938 exec_function(funcp, argv)
6940 static void exec_function(char ***to_free,
6941 const struct function *funcp,
6942 char **argv) NORETURN;
6943 static void exec_function(char ***to_free,
6944 const struct function *funcp,
6950 argv[0] = G.global_argv[0];
6951 G.global_argv = argv;
6952 G.global_argc = n = 1 + string_array_len(argv + 1);
6953 /* On MMU, funcp->body is always non-NULL */
6954 n = run_list(funcp->body);
6958 re_execute_shell(to_free,
6959 funcp->body_as_string,
6966 static int run_function(const struct function *funcp, char **argv)
6972 save_and_replace_G_args(&sv, argv);
6974 /* "we are in function, ok to use return" */
6975 sv_flg = G_flag_return_in_progress;
6976 G_flag_return_in_progress = -1;
6977 # if ENABLE_HUSH_LOCAL
6978 G.func_nest_level++;
6981 /* On MMU, funcp->body is always non-NULL */
6984 /* Function defined by -F */
6985 parse_and_run_string(funcp->body_as_string);
6986 rc = G.last_exitcode;
6990 rc = run_list(funcp->body);
6993 # if ENABLE_HUSH_LOCAL
6995 struct variable *var;
6996 struct variable **var_pp;
6998 var_pp = &G.top_var;
6999 while ((var = *var_pp) != NULL) {
7000 if (var->func_nest_level < G.func_nest_level) {
7001 var_pp = &var->next;
7005 if (var->flg_export)
7006 bb_unsetenv(var->varstr);
7007 /* Remove from global list */
7008 *var_pp = var->next;
7014 G.func_nest_level--;
7017 G_flag_return_in_progress = sv_flg;
7019 restore_G_args(&sv, argv);
7023 #endif /* ENABLE_HUSH_FUNCTIONS */
7027 #define exec_builtin(to_free, x, argv) \
7028 exec_builtin(x, argv)
7030 #define exec_builtin(to_free, x, argv) \
7031 exec_builtin(to_free, argv)
7033 static void exec_builtin(char ***to_free,
7034 const struct built_in_command *x,
7035 char **argv) NORETURN;
7036 static void exec_builtin(char ***to_free,
7037 const struct built_in_command *x,
7043 rcode = x->b_function(argv);
7048 /* On NOMMU, we must never block!
7049 * Example: { sleep 99 | read line; } & echo Ok
7051 re_execute_shell(to_free,
7060 static void execvp_or_die(char **argv) NORETURN;
7061 static void execvp_or_die(char **argv)
7064 debug_printf_exec("execing '%s'\n", argv[0]);
7065 /* Don't propagate SIG_IGN to the child */
7066 if (SPECIAL_JOBSTOP_SIGS != 0)
7067 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7068 execvp(argv[0], argv);
7070 if (errno == EACCES) e = 126;
7071 if (errno == ENOENT) e = 127;
7072 bb_perror_msg("can't execute '%s'", argv[0]);
7076 #if ENABLE_HUSH_MODE_X
7077 static void dump_cmd_in_x_mode(char **argv)
7079 if (G_x_mode && argv) {
7080 /* We want to output the line in one write op */
7088 len += strlen(argv[n++]) + 1;
7094 p += sprintf(p, " %s", argv[n++]);
7102 # define dump_cmd_in_x_mode(argv) ((void)0)
7106 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7107 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7108 #define pseudo_exec(nommu_save, command, argv_expanded) \
7109 pseudo_exec(command, argv_expanded)
7112 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7114 * Don't exit() here. If you don't exec, use _exit instead.
7115 * The at_exit handlers apparently confuse the calling process,
7116 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7118 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7119 char **argv, int assignment_cnt,
7120 char **argv_expanded) NORETURN;
7121 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7122 char **argv, int assignment_cnt,
7123 char **argv_expanded)
7127 new_env = expand_assignments(argv, assignment_cnt);
7128 dump_cmd_in_x_mode(new_env);
7130 if (!argv[assignment_cnt]) {
7131 /* Case when we are here: ... | var=val | ...
7132 * (note that we do not exit early, i.e., do not optimize out
7133 * expand_assignments(): think about ... | var=`sleep 1` | ...
7135 free_strings(new_env);
7136 _exit(EXIT_SUCCESS);
7140 set_vars_and_save_old(new_env);
7141 free(new_env); /* optional */
7142 /* we can also destroy set_vars_and_save_old's return value,
7145 nommu_save->new_env = new_env;
7146 nommu_save->old_vars = set_vars_and_save_old(new_env);
7149 if (argv_expanded) {
7150 argv = argv_expanded;
7152 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7154 nommu_save->argv = argv;
7157 dump_cmd_in_x_mode(argv);
7159 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7160 if (strchr(argv[0], '/') != NULL)
7164 /* Check if the command matches any of the builtins.
7165 * Depending on context, this might be redundant. But it's
7166 * easier to waste a few CPU cycles than it is to figure out
7167 * if this is one of those cases.
7170 /* On NOMMU, it is more expensive to re-execute shell
7171 * just in order to run echo or test builtin.
7172 * It's better to skip it here and run corresponding
7173 * non-builtin later. */
7174 const struct built_in_command *x;
7175 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7177 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7180 #if ENABLE_HUSH_FUNCTIONS
7181 /* Check if the command matches any functions */
7183 const struct function *funcp = find_function(argv[0]);
7185 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7190 #if ENABLE_FEATURE_SH_STANDALONE
7191 /* Check if the command matches any busybox applets */
7193 int a = find_applet_by_name(argv[0]);
7195 # if BB_MMU /* see above why on NOMMU it is not allowed */
7196 if (APPLET_IS_NOEXEC(a)) {
7197 /* Do not leak open fds from opened script files etc */
7198 close_all_FILE_list();
7199 debug_printf_exec("running applet '%s'\n", argv[0]);
7200 run_applet_no_and_exit(a, argv[0], argv);
7203 /* Re-exec ourselves */
7204 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7205 /* Don't propagate SIG_IGN to the child */
7206 if (SPECIAL_JOBSTOP_SIGS != 0)
7207 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7208 execv(bb_busybox_exec_path, argv);
7209 /* If they called chroot or otherwise made the binary no longer
7210 * executable, fall through */
7215 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7218 execvp_or_die(argv);
7221 /* Called after [v]fork() in run_pipe
7223 static void pseudo_exec(nommu_save_t *nommu_save,
7224 struct command *command,
7225 char **argv_expanded) NORETURN;
7226 static void pseudo_exec(nommu_save_t *nommu_save,
7227 struct command *command,
7228 char **argv_expanded)
7230 if (command->argv) {
7231 pseudo_exec_argv(nommu_save, command->argv,
7232 command->assignment_cnt, argv_expanded);
7235 if (command->group) {
7236 /* Cases when we are here:
7239 * ... | ( list ) | ...
7240 * ... | { list } | ...
7244 debug_printf_exec("pseudo_exec: run_list\n");
7245 reset_traps_to_defaults();
7246 rcode = run_list(command->group);
7247 /* OK to leak memory by not calling free_pipe_list,
7248 * since this process is about to exit */
7251 re_execute_shell(&nommu_save->argv_from_re_execing,
7252 command->group_as_string,
7259 /* Case when we are here: ... | >file */
7260 debug_printf_exec("pseudo_exec'ed null command\n");
7261 _exit(EXIT_SUCCESS);
7265 static const char *get_cmdtext(struct pipe *pi)
7271 /* This is subtle. ->cmdtext is created only on first backgrounding.
7272 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7273 * On subsequent bg argv is trashed, but we won't use it */
7277 argv = pi->cmds[0].argv;
7279 pi->cmdtext = xzalloc(1);
7284 len += strlen(*argv) + 1;
7288 argv = pi->cmds[0].argv;
7290 p = stpcpy(p, *argv);
7297 static void remove_job_from_table(struct pipe *pi)
7299 struct pipe *prev_pipe;
7301 if (pi == G.job_list) {
7302 G.job_list = pi->next;
7304 prev_pipe = G.job_list;
7305 while (prev_pipe->next != pi)
7306 prev_pipe = prev_pipe->next;
7307 prev_pipe->next = pi->next;
7311 G.last_jobid = G.job_list->jobid;
7314 static void delete_finished_job(struct pipe *pi)
7316 remove_job_from_table(pi);
7320 static void clean_up_last_dead_job(void)
7322 if (G.job_list && !G.job_list->alive_cmds)
7323 delete_finished_job(G.job_list);
7326 static void insert_job_into_table(struct pipe *pi)
7328 struct pipe *job, **jobp;
7331 clean_up_last_dead_job();
7333 /* Find the end of the list, and find next job ID to use */
7336 while ((job = *jobp) != NULL) {
7343 /* Create a new job struct at the end */
7344 job = *jobp = xmemdup(pi, sizeof(*pi));
7346 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7347 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7348 for (i = 0; i < pi->num_cmds; i++) {
7349 job->cmds[i].pid = pi->cmds[i].pid;
7350 /* all other fields are not used and stay zero */
7352 job->cmdtext = xstrdup(get_cmdtext(pi));
7354 if (G_interactive_fd)
7355 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7356 G.last_jobid = job->jobid;
7360 static int job_exited_or_stopped(struct pipe *pi)
7364 if (pi->alive_cmds != pi->stopped_cmds)
7367 /* All processes in fg pipe have exited or stopped */
7371 rcode = pi->cmds[i].cmd_exitcode;
7372 /* usually last process gives overall exitstatus,
7373 * but with "set -o pipefail", last *failed* process does */
7374 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7377 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7381 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7388 dead = WIFEXITED(status) || WIFSIGNALED(status);
7391 if (WIFSTOPPED(status))
7392 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7393 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7394 if (WIFSIGNALED(status))
7395 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7396 childpid, WTERMSIG(status), WEXITSTATUS(status));
7397 if (WIFEXITED(status))
7398 debug_printf_jobs("pid %d exited, exitcode %d\n",
7399 childpid, WEXITSTATUS(status));
7401 /* Were we asked to wait for a fg pipe? */
7403 i = fg_pipe->num_cmds;
7408 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7409 if (fg_pipe->cmds[i].pid != childpid)
7413 fg_pipe->cmds[i].pid = 0;
7414 fg_pipe->alive_cmds--;
7415 ex = WEXITSTATUS(status);
7416 /* bash prints killer signal's name for *last*
7417 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7418 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7420 if (WIFSIGNALED(status)) {
7421 int sig = WTERMSIG(status);
7422 if (i == fg_pipe->num_cmds-1)
7423 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7424 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7425 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7426 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7427 * Maybe we need to use sig | 128? */
7430 fg_pipe->cmds[i].cmd_exitcode = ex;
7432 fg_pipe->stopped_cmds++;
7434 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7435 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7436 rcode = job_exited_or_stopped(fg_pipe);
7438 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7439 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7440 * and "killall -STOP cat" */
7441 if (G_interactive_fd) {
7443 if (fg_pipe->alive_cmds != 0)
7444 insert_job_into_table(fg_pipe);
7448 if (fg_pipe->alive_cmds == 0)
7451 /* There are still running processes in the fg_pipe */
7454 /* It wasn't in fg_pipe, look for process in bg pipes */
7458 /* We were asked to wait for bg or orphaned children */
7459 /* No need to remember exitcode in this case */
7460 for (pi = G.job_list; pi; pi = pi->next) {
7461 for (i = 0; i < pi->num_cmds; i++) {
7462 if (pi->cmds[i].pid == childpid)
7463 goto found_pi_and_prognum;
7466 /* Happens when shell is used as init process (init=/bin/sh) */
7467 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7468 return -1; /* this wasn't a process from fg_pipe */
7470 found_pi_and_prognum:
7473 int rcode = WEXITSTATUS(status);
7474 if (WIFSIGNALED(status))
7475 rcode = 128 + WTERMSIG(status);
7476 pi->cmds[i].cmd_exitcode = rcode;
7477 if (G.last_bg_pid == pi->cmds[i].pid)
7478 G.last_bg_pid_exitcode = rcode;
7479 pi->cmds[i].pid = 0;
7481 if (!pi->alive_cmds) {
7482 if (G_interactive_fd) {
7483 printf(JOB_STATUS_FORMAT, pi->jobid,
7484 "Done", pi->cmdtext);
7485 delete_finished_job(pi);
7488 * bash deletes finished jobs from job table only in interactive mode,
7489 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7490 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7491 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7492 * We only retain one "dead" job, if it's the single job on the list.
7493 * This covers most of real-world scenarios where this is useful.
7495 if (pi != G.job_list)
7496 delete_finished_job(pi);
7504 return -1; /* this wasn't a process from fg_pipe */
7507 /* Check to see if any processes have exited -- if they have,
7508 * figure out why and see if a job has completed.
7510 * If non-NULL fg_pipe: wait for its completion or stop.
7511 * Return its exitcode or zero if stopped.
7513 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7514 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7515 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7516 * or 0 if no children changed status.
7518 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7519 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7520 * or 0 if no children changed status.
7522 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7528 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7530 attributes = WUNTRACED;
7531 if (fg_pipe == NULL)
7532 attributes |= WNOHANG;
7535 #if ENABLE_HUSH_FAST
7536 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7537 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7538 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7539 /* There was neither fork nor SIGCHLD since last waitpid */
7540 /* Avoid doing waitpid syscall if possible */
7541 if (!G.we_have_children) {
7545 if (fg_pipe == NULL) { /* is WNOHANG set? */
7546 /* We have children, but they did not exit
7547 * or stop yet (we saw no SIGCHLD) */
7550 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7554 /* Do we do this right?
7555 * bash-3.00# sleep 20 | false
7557 * [3]+ Stopped sleep 20 | false
7558 * bash-3.00# echo $?
7559 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7560 * [hush 1.14.0: yes we do it right]
7564 #if ENABLE_HUSH_FAST
7566 i = G.count_SIGCHLD;
7568 childpid = waitpid(-1, &status, attributes);
7569 if (childpid <= 0) {
7570 if (childpid && errno != ECHILD)
7571 bb_perror_msg("waitpid");
7572 #if ENABLE_HUSH_FAST
7573 else { /* Until next SIGCHLD, waitpid's are useless */
7574 G.we_have_children = (childpid == 0);
7575 G.handled_SIGCHLD = i;
7576 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7579 /* ECHILD (no children), or 0 (no change in children status) */
7583 rcode = process_wait_result(fg_pipe, childpid, status);
7585 /* fg_pipe exited or stopped */
7588 if (childpid == waitfor_pid) {
7589 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7590 rcode = WEXITSTATUS(status);
7591 if (WIFSIGNALED(status))
7592 rcode = 128 + WTERMSIG(status);
7593 if (WIFSTOPPED(status))
7594 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7595 rcode = 128 + WSTOPSIG(status);
7597 break; /* "wait PID" called us, give it exitcode+1 */
7599 /* This wasn't one of our processes, or */
7600 /* fg_pipe still has running processes, do waitpid again */
7601 } /* while (waitpid succeeds)... */
7607 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7610 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7611 if (G_saved_tty_pgrp) {
7612 /* Job finished, move the shell to the foreground */
7613 p = getpgrp(); /* our process group id */
7614 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7615 tcsetpgrp(G_interactive_fd, p);
7621 /* Start all the jobs, but don't wait for anything to finish.
7624 * Return code is normally -1, when the caller has to wait for children
7625 * to finish to determine the exit status of the pipe. If the pipe
7626 * is a simple builtin command, however, the action is done by the
7627 * time run_pipe returns, and the exit code is provided as the
7630 * Returns -1 only if started some children. IOW: we have to
7631 * mask out retvals of builtins etc with 0xff!
7633 * The only case when we do not need to [v]fork is when the pipe
7634 * is single, non-backgrounded, non-subshell command. Examples:
7635 * cmd ; ... { list } ; ...
7636 * cmd && ... { list } && ...
7637 * cmd || ... { list } || ...
7638 * If it is, then we can run cmd as a builtin, NOFORK,
7639 * or (if SH_STANDALONE) an applet, and we can run the { list }
7640 * with run_list. If it isn't one of these, we fork and exec cmd.
7642 * Cases when we must fork:
7643 * non-single: cmd | cmd
7644 * backgrounded: cmd & { list } &
7645 * subshell: ( list ) [&]
7647 #if !ENABLE_HUSH_MODE_X
7648 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7649 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7651 static int redirect_and_varexp_helper(char ***new_env_p,
7652 struct variable **old_vars_p,
7653 struct command *command,
7654 struct squirrel **sqp,
7655 char **argv_expanded)
7657 /* setup_redirects acts on file descriptors, not FILEs.
7658 * This is perfect for work that comes after exec().
7659 * Is it really safe for inline use? Experimentally,
7660 * things seem to work. */
7661 int rcode = setup_redirects(command, sqp);
7663 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7664 *new_env_p = new_env;
7665 dump_cmd_in_x_mode(new_env);
7666 dump_cmd_in_x_mode(argv_expanded);
7668 *old_vars_p = set_vars_and_save_old(new_env);
7672 static NOINLINE int run_pipe(struct pipe *pi)
7674 static const char *const null_ptr = NULL;
7678 struct command *command;
7679 char **argv_expanded;
7681 struct squirrel *squirrel = NULL;
7684 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7687 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7688 * Result should be 3 lines: q w e, qwe, q w e
7690 G.ifs = get_local_var_value("IFS");
7694 IF_HUSH_JOB(pi->pgrp = -1;)
7695 pi->stopped_cmds = 0;
7696 command = &pi->cmds[0];
7697 argv_expanded = NULL;
7699 if (pi->num_cmds != 1
7700 || pi->followup == PIPE_BG
7701 || command->cmd_type == CMD_SUBSHELL
7708 debug_printf_exec(": group:%p argv:'%s'\n",
7709 command->group, command->argv ? command->argv[0] : "NONE");
7711 if (command->group) {
7712 #if ENABLE_HUSH_FUNCTIONS
7713 if (command->cmd_type == CMD_FUNCDEF) {
7714 /* "executing" func () { list } */
7715 struct function *funcp;
7717 funcp = new_function(command->argv[0]);
7718 /* funcp->name is already set to argv[0] */
7719 funcp->body = command->group;
7721 funcp->body_as_string = command->group_as_string;
7722 command->group_as_string = NULL;
7724 command->group = NULL;
7725 command->argv[0] = NULL;
7726 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7727 funcp->parent_cmd = command;
7728 command->child_func = funcp;
7730 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7732 return EXIT_SUCCESS;
7736 debug_printf("non-subshell group\n");
7737 rcode = 1; /* exitcode if redir failed */
7738 if (setup_redirects(command, &squirrel) == 0) {
7739 debug_printf_exec(": run_list\n");
7740 rcode = run_list(command->group) & 0xff;
7742 restore_redirects(squirrel);
7743 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7745 debug_printf_exec("run_pipe: return %d\n", rcode);
7749 argv = command->argv ? command->argv : (char **) &null_ptr;
7751 const struct built_in_command *x;
7752 #if ENABLE_HUSH_FUNCTIONS
7753 const struct function *funcp;
7757 char **new_env = NULL;
7758 struct variable *old_vars = NULL;
7760 if (argv[command->assignment_cnt] == NULL) {
7761 /* Assignments, but no command */
7762 /* Ensure redirects take effect (that is, create files).
7763 * Try "a=t >file" */
7764 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7765 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7766 /* Set shell variables */
7770 if (set_local_var(*argv, /*flag:*/ 0)) {
7771 /* assignment to readonly var / putenv error? */
7777 /* Redirect error sets $? to 1. Otherwise,
7778 * if evaluating assignment value set $?, retain it.
7779 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7781 rcode = G.last_exitcode;
7782 /* Exit, _skipping_ variable restoring code: */
7783 goto clean_up_and_ret0;
7785 #else /* Older, bigger, but more correct code */
7787 rcode = setup_redirects(command, &squirrel);
7788 restore_redirects(squirrel);
7789 /* Set shell variables */
7791 bb_putchar_stderr('+');
7793 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7795 fprintf(stderr, " %s", p);
7796 debug_printf_exec("set shell var:'%s'->'%s'\n",
7798 if (set_local_var(p, /*flag:*/ 0)) {
7799 /* assignment to readonly var / putenv error? */
7805 bb_putchar_stderr('\n');
7806 /* Redirect error sets $? to 1. Otherwise,
7807 * if evaluating assignment value set $?, retain it.
7808 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7810 rcode = G.last_exitcode;
7811 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7813 debug_printf_exec("run_pipe: return %d\n", rcode);
7818 /* Expand the rest into (possibly) many strings each */
7820 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7821 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7825 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7828 /* if someone gives us an empty string: `cmd with empty output` */
7829 if (!argv_expanded[0]) {
7830 free(argv_expanded);
7832 return G.last_exitcode;
7835 x = find_builtin(argv_expanded[0]);
7836 #if ENABLE_HUSH_FUNCTIONS
7839 funcp = find_function(argv_expanded[0]);
7843 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7844 debug_printf("exec with redirects only\n");
7845 rcode = setup_redirects(command, NULL);
7846 /* rcode=1 can be if redir file can't be opened */
7847 goto clean_up_and_ret1;
7850 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7853 debug_printf_exec(": builtin '%s' '%s'...\n",
7854 x->b_cmd, argv_expanded[1]);
7856 rcode = x->b_function(argv_expanded) & 0xff;
7859 #if ENABLE_HUSH_FUNCTIONS
7861 # if ENABLE_HUSH_LOCAL
7862 struct variable **sv;
7863 sv = G.shadowed_vars_pp;
7864 G.shadowed_vars_pp = &old_vars;
7866 debug_printf_exec(": function '%s' '%s'...\n",
7867 funcp->name, argv_expanded[1]);
7868 rcode = run_function(funcp, argv_expanded) & 0xff;
7869 # if ENABLE_HUSH_LOCAL
7870 G.shadowed_vars_pp = sv;
7876 unset_vars(new_env);
7878 /* clean_up_and_ret0: */
7879 restore_redirects(squirrel);
7881 free(argv_expanded);
7882 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7884 debug_printf_exec("run_pipe return %d\n", rcode);
7888 if (ENABLE_FEATURE_SH_NOFORK) {
7889 int n = find_applet_by_name(argv_expanded[0]);
7890 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7891 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7893 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7894 argv_expanded[0], argv_expanded[1]);
7895 rcode = run_nofork_applet(n, argv_expanded);
7897 goto clean_up_and_ret;
7900 /* It is neither builtin nor applet. We must fork. */
7904 /* NB: argv_expanded may already be created, and that
7905 * might include `cmd` runs! Do not rerun it! We *must*
7906 * use argv_expanded if it's non-NULL */
7908 /* Going to fork a child per each pipe member */
7913 while (cmd_no < pi->num_cmds) {
7914 struct fd_pair pipefds;
7916 volatile nommu_save_t nommu_save;
7917 nommu_save.new_env = NULL;
7918 nommu_save.old_vars = NULL;
7919 nommu_save.argv = NULL;
7920 nommu_save.argv_from_re_execing = NULL;
7922 command = &pi->cmds[cmd_no];
7924 if (command->argv) {
7925 debug_printf_exec(": pipe member '%s' '%s'...\n",
7926 command->argv[0], command->argv[1]);
7928 debug_printf_exec(": pipe member with no argv\n");
7931 /* pipes are inserted between pairs of commands */
7934 if (cmd_no < pi->num_cmds)
7935 xpiped_pair(pipefds);
7937 command->pid = BB_MMU ? fork() : vfork();
7938 if (!command->pid) { /* child */
7940 disable_restore_tty_pgrp_on_exit();
7941 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7943 /* Every child adds itself to new process group
7944 * with pgid == pid_of_first_child_in_pipe */
7945 if (G.run_list_level == 1 && G_interactive_fd) {
7948 if (pgrp < 0) /* true for 1st process only */
7950 if (setpgid(0, pgrp) == 0
7951 && pi->followup != PIPE_BG
7952 && G_saved_tty_pgrp /* we have ctty */
7954 /* We do it in *every* child, not just first,
7956 tcsetpgrp(G_interactive_fd, pgrp);
7960 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7961 /* 1st cmd in backgrounded pipe
7962 * should have its stdin /dev/null'ed */
7964 if (open(bb_dev_null, O_RDONLY))
7965 xopen("/", O_RDONLY);
7967 xmove_fd(next_infd, 0);
7969 xmove_fd(pipefds.wr, 1);
7972 /* Like bash, explicit redirects override pipes,
7973 * and the pipe fd (fd#1) is available for dup'ing:
7974 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7975 * of cmd1 goes into pipe.
7977 if (setup_redirects(command, NULL)) {
7978 /* Happens when redir file can't be opened:
7979 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7981 * hush: can't open '/qwe/rty': No such file or directory
7983 * (echo BAR is not executed, it hits _exit(1) below)
7988 /* Stores to nommu_save list of env vars putenv'ed
7989 * (NOMMU, on MMU we don't need that) */
7990 /* cast away volatility... */
7991 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7992 /* pseudo_exec() does not return */
7995 /* parent or error */
7996 #if ENABLE_HUSH_FAST
7998 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8000 enable_restore_tty_pgrp_on_exit();
8002 /* Clean up after vforked child */
8003 free(nommu_save.argv);
8004 free(nommu_save.argv_from_re_execing);
8005 unset_vars(nommu_save.new_env);
8006 add_vars(nommu_save.old_vars);
8008 free(argv_expanded);
8009 argv_expanded = NULL;
8010 if (command->pid < 0) { /* [v]fork failed */
8011 /* Clearly indicate, was it fork or vfork */
8012 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8016 /* Second and next children need to know pid of first one */
8018 pi->pgrp = command->pid;
8024 if (cmd_no < pi->num_cmds)
8026 /* Pass read (output) pipe end to next iteration */
8027 next_infd = pipefds.rd;
8030 if (!pi->alive_cmds) {
8032 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8037 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8041 /* NB: called by pseudo_exec, and therefore must not modify any
8042 * global data until exec/_exit (we can be a child after vfork!) */
8043 static int run_list(struct pipe *pi)
8045 #if ENABLE_HUSH_CASE
8046 char *case_word = NULL;
8048 #if ENABLE_HUSH_LOOPS
8049 struct pipe *loop_top = NULL;
8050 char **for_lcur = NULL;
8051 char **for_list = NULL;
8053 smallint last_followup;
8055 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8056 smalluint cond_code = 0;
8058 enum { cond_code = 0 };
8061 smallint rword; /* RES_foo */
8062 smallint last_rword; /* ditto */
8065 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8068 #if ENABLE_HUSH_LOOPS
8069 /* Check syntax for "for" */
8072 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8073 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8075 /* current word is FOR or IN (BOLD in comments below) */
8076 if (cpipe->next == NULL) {
8077 syntax_error("malformed for");
8079 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8082 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8083 if (cpipe->next->res_word == RES_DO)
8085 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8086 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8087 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8089 syntax_error("malformed for");
8091 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8098 /* Past this point, all code paths should jump to ret: label
8099 * in order to return, no direct "return" statements please.
8100 * This helps to ensure that no memory is leaked. */
8108 last_rword = RES_XXXX;
8110 last_followup = PIPE_SEQ;
8111 rcode = G.last_exitcode;
8113 /* Go through list of pipes, (maybe) executing them. */
8114 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8116 int sv_errexit_depth;
8120 if (G_flag_return_in_progress == 1)
8123 IF_HAS_KEYWORDS(rword = pi->res_word;)
8124 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8125 rword, cond_code, last_rword);
8127 sv_errexit_depth = G.errexit_depth;
8128 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8129 pi->followup != PIPE_SEQ
8133 #if ENABLE_HUSH_LOOPS
8134 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8135 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8137 /* start of a loop: remember where loop starts */
8142 /* Still in the same "if...", "then..." or "do..." branch? */
8143 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8144 if ((rcode == 0 && last_followup == PIPE_OR)
8145 || (rcode != 0 && last_followup == PIPE_AND)
8147 /* It is "<true> || CMD" or "<false> && CMD"
8148 * and we should not execute CMD */
8149 debug_printf_exec("skipped cmd because of || or &&\n");
8150 last_followup = pi->followup;
8151 goto dont_check_jobs_but_continue;
8154 last_followup = pi->followup;
8155 IF_HAS_KEYWORDS(last_rword = rword;)
8158 if (rword == RES_THEN) {
8159 /* if false; then ... fi has exitcode 0! */
8160 G.last_exitcode = rcode = EXIT_SUCCESS;
8161 /* "if <false> THEN cmd": skip cmd */
8165 if (rword == RES_ELSE || rword == RES_ELIF) {
8166 /* "if <true> then ... ELSE/ELIF cmd":
8167 * skip cmd and all following ones */
8172 #if ENABLE_HUSH_LOOPS
8173 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8175 /* first loop through for */
8177 static const char encoded_dollar_at[] ALIGN1 = {
8178 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8179 }; /* encoded representation of "$@" */
8180 static const char *const encoded_dollar_at_argv[] = {
8181 encoded_dollar_at, NULL
8182 }; /* argv list with one element: "$@" */
8185 vals = (char**)encoded_dollar_at_argv;
8186 if (pi->next->res_word == RES_IN) {
8187 /* if no variable values after "in" we skip "for" */
8188 if (!pi->next->cmds[0].argv) {
8189 G.last_exitcode = rcode = EXIT_SUCCESS;
8190 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8193 vals = pi->next->cmds[0].argv;
8194 } /* else: "for var; do..." -> assume "$@" list */
8195 /* create list of variable values */
8196 debug_print_strings("for_list made from", vals);
8197 for_list = expand_strvec_to_strvec(vals);
8198 for_lcur = for_list;
8199 debug_print_strings("for_list", for_list);
8202 /* "for" loop is over, clean up */
8208 /* Insert next value from for_lcur */
8209 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8210 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8213 if (rword == RES_IN) {
8214 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8216 if (rword == RES_DONE) {
8217 continue; /* "done" has no cmds too */
8220 #if ENABLE_HUSH_CASE
8221 if (rword == RES_CASE) {
8222 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8223 case_word = expand_strvec_to_string(pi->cmds->argv);
8224 unbackslash(case_word);
8227 if (rword == RES_MATCH) {
8230 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8231 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8233 /* all prev words didn't match, does this one match? */
8234 argv = pi->cmds->argv;
8236 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8237 /* TODO: which FNM_xxx flags to use? */
8238 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8239 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8241 if (cond_code == 0) { /* match! we will execute this branch */
8243 case_word = NULL; /* make future "word)" stop */
8250 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8251 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8253 continue; /* not matched yet, skip this pipe */
8255 if (rword == RES_ESAC) {
8256 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8258 /* "case" did not match anything: still set $? (to 0) */
8259 G.last_exitcode = rcode = EXIT_SUCCESS;
8263 /* Just pressing <enter> in shell should check for jobs.
8264 * OTOH, in non-interactive shell this is useless
8265 * and only leads to extra job checks */
8266 if (pi->num_cmds == 0) {
8267 if (G_interactive_fd)
8268 goto check_jobs_and_continue;
8272 /* After analyzing all keywords and conditions, we decided
8273 * to execute this pipe. NB: have to do checkjobs(NULL)
8274 * after run_pipe to collect any background children,
8275 * even if list execution is to be stopped. */
8276 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8277 #if ENABLE_HUSH_LOOPS
8278 G.flag_break_continue = 0;
8280 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8282 /* We ran a builtin, function, or group.
8283 * rcode is already known
8284 * and we don't need to wait for anything. */
8285 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8286 G.last_exitcode = rcode;
8287 check_and_run_traps();
8288 #if ENABLE_HUSH_LOOPS
8289 /* Was it "break" or "continue"? */
8290 if (G.flag_break_continue) {
8291 smallint fbc = G.flag_break_continue;
8292 /* We might fall into outer *loop*,
8293 * don't want to break it too */
8295 G.depth_break_continue--;
8296 if (G.depth_break_continue == 0)
8297 G.flag_break_continue = 0;
8298 /* else: e.g. "continue 2" should *break* once, *then* continue */
8299 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8300 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8301 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8304 /* "continue": simulate end of loop */
8309 if (G_flag_return_in_progress == 1) {
8310 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8313 } else if (pi->followup == PIPE_BG) {
8314 /* What does bash do with attempts to background builtins? */
8315 /* even bash 3.2 doesn't do that well with nested bg:
8316 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8317 * I'm NOT treating inner &'s as jobs */
8319 if (G.run_list_level == 1)
8320 insert_job_into_table(pi);
8322 /* Last command's pid goes to $! */
8323 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8324 G.last_bg_pid_exitcode = 0;
8325 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8326 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8327 rcode = EXIT_SUCCESS;
8331 if (G.run_list_level == 1 && G_interactive_fd) {
8332 /* Waits for completion, then fg's main shell */
8333 rcode = checkjobs_and_fg_shell(pi);
8334 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8338 /* This one just waits for completion */
8339 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8340 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8342 G.last_exitcode = rcode;
8343 check_and_run_traps();
8346 /* Handle "set -e" */
8347 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8348 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8349 if (G.errexit_depth == 0)
8352 G.errexit_depth = sv_errexit_depth;
8354 /* Analyze how result affects subsequent commands */
8356 if (rword == RES_IF || rword == RES_ELIF)
8359 check_jobs_and_continue:
8360 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8361 dont_check_jobs_but_continue: ;
8362 #if ENABLE_HUSH_LOOPS
8363 /* Beware of "while false; true; do ..."! */
8365 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8366 /* check for RES_DONE is needed for "while ...; do \n done" case */
8368 if (rword == RES_WHILE) {
8370 /* "while false; do...done" - exitcode 0 */
8371 G.last_exitcode = rcode = EXIT_SUCCESS;
8372 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8376 if (rword == RES_UNTIL) {
8378 debug_printf_exec(": until expr is true: breaking\n");
8389 #if ENABLE_HUSH_LOOPS
8394 #if ENABLE_HUSH_CASE
8398 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8402 /* Select which version we will use */
8403 static int run_and_free_list(struct pipe *pi)
8406 debug_printf_exec("run_and_free_list entered\n");
8407 if (!G.o_opt[OPT_O_NOEXEC]) {
8408 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8409 rcode = run_list(pi);
8411 /* free_pipe_list has the side effect of clearing memory.
8412 * In the long run that function can be merged with run_list,
8413 * but doing that now would hobble the debugging effort. */
8415 debug_printf_exec("run_and_free_list return %d\n", rcode);
8420 static void install_sighandlers(unsigned mask)
8422 sighandler_t old_handler;
8424 while ((mask >>= 1) != 0) {
8428 old_handler = install_sighandler(sig, pick_sighandler(sig));
8429 /* POSIX allows shell to re-enable SIGCHLD
8430 * even if it was SIG_IGN on entry.
8431 * Therefore we skip IGN check for it:
8435 if (old_handler == SIG_IGN) {
8436 /* oops... restore back to IGN, and record this fact */
8437 install_sighandler(sig, old_handler);
8438 #if ENABLE_HUSH_TRAP
8440 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8442 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8448 /* Called a few times only (or even once if "sh -c") */
8449 static void install_special_sighandlers(void)
8453 /* Which signals are shell-special? */
8454 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8455 if (G_interactive_fd) {
8456 mask |= SPECIAL_INTERACTIVE_SIGS;
8457 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8458 mask |= SPECIAL_JOBSTOP_SIGS;
8460 /* Careful, do not re-install handlers we already installed */
8461 if (G.special_sig_mask != mask) {
8462 unsigned diff = mask & ~G.special_sig_mask;
8463 G.special_sig_mask = mask;
8464 install_sighandlers(diff);
8470 /* Set handlers to restore tty pgrp and exit */
8471 static void install_fatal_sighandlers(void)
8475 /* We will restore tty pgrp on these signals */
8477 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8478 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8479 + (1 << SIGBUS ) * HUSH_DEBUG
8480 + (1 << SIGSEGV) * HUSH_DEBUG
8481 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8483 /* bash 3.2 seems to handle these just like 'fatal' ones */
8486 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8487 * if we aren't interactive... but in this case
8488 * we never want to restore pgrp on exit, and this fn is not called
8490 /*+ (1 << SIGHUP )*/
8491 /*+ (1 << SIGTERM)*/
8492 /*+ (1 << SIGINT )*/
8494 G_fatal_sig_mask = mask;
8496 install_sighandlers(mask);
8500 static int set_mode(int state, char mode, const char *o_opt)
8505 G.o_opt[OPT_O_NOEXEC] = state;
8508 IF_HUSH_MODE_X(G_x_mode = state;)
8512 /* "set -+o" without parameter.
8513 * in bash, set -o produces this output:
8517 * We always use the second form.
8519 const char *p = o_opt_strings;
8522 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8528 idx = index_in_strings(o_opt_strings, o_opt);
8530 G.o_opt[idx] = state;
8534 G.o_opt[OPT_O_ERREXIT] = state;
8537 return EXIT_FAILURE;
8539 return EXIT_SUCCESS;
8542 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8543 int hush_main(int argc, char **argv)
8546 OPT_login = (1 << 0),
8550 unsigned builtin_argc;
8552 struct variable *cur_var;
8553 struct variable *shell_ver;
8556 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8557 G.last_exitcode = EXIT_SUCCESS;
8559 #if ENABLE_HUSH_FAST
8560 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8563 G.argv0_for_re_execing = argv[0];
8565 /* Deal with HUSH_VERSION */
8566 shell_ver = xzalloc(sizeof(*shell_ver));
8567 shell_ver->flg_export = 1;
8568 shell_ver->flg_read_only = 1;
8569 /* Code which handles ${var<op>...} needs writable values for all variables,
8570 * therefore we xstrdup: */
8571 shell_ver->varstr = xstrdup(hush_version_str);
8572 /* Create shell local variables from the values
8573 * currently living in the environment */
8574 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8575 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8576 G.top_var = shell_ver;
8577 cur_var = G.top_var;
8580 char *value = strchr(*e, '=');
8581 if (value) { /* paranoia */
8582 cur_var->next = xzalloc(sizeof(*cur_var));
8583 cur_var = cur_var->next;
8584 cur_var->varstr = *e;
8585 cur_var->max_len = strlen(*e);
8586 cur_var->flg_export = 1;
8590 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8591 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8592 putenv(shell_ver->varstr);
8595 set_pwd_var(SETFLAG_EXPORT);
8597 #if BASH_HOSTNAME_VAR
8598 /* Set (but not export) HOSTNAME unless already set */
8599 if (!get_local_var_value("HOSTNAME")) {
8602 set_local_var_from_halves("HOSTNAME", uts.nodename);
8604 /* bash also exports SHLVL and _,
8605 * and sets (but doesn't export) the following variables:
8607 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8608 * BASH_VERSION='3.2.0(1)-release'
8610 * MACHTYPE=i386-pc-linux-gnu
8612 * PPID=<NNNNN> - we also do it elsewhere
8623 * PIPESTATUS=([0]="0")
8624 * HISTFILE=/<xxx>/.bash_history
8628 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8630 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8641 #if ENABLE_FEATURE_EDITING
8642 G.line_input_state = new_line_input_t(FOR_SHELL);
8645 /* Initialize some more globals to non-zero values */
8646 cmdedit_update_prompt();
8648 die_func = restore_ttypgrp_and__exit;
8650 /* Shell is non-interactive at first. We need to call
8651 * install_special_sighandlers() if we are going to execute "sh <script>",
8652 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8653 * If we later decide that we are interactive, we run install_special_sighandlers()
8654 * in order to intercept (more) signals.
8658 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8659 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8662 opt = getopt(argc, argv, "+c:exinsl"
8665 # if ENABLE_HUSH_FUNCTIONS
8675 * sh ... -c 'script'
8676 * sh ... -c 'script' ARG0 [ARG1...]
8677 * On NOMMU, if builtin_argc != 0,
8678 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8679 * "" needs to be replaced with NULL
8680 * and BARGV vector fed to builtin function.
8681 * Note: the form without ARG0 never happens:
8682 * sh ... -c 'builtin' BARGV... ""
8685 G.root_pid = getpid();
8686 G.root_ppid = getppid();
8688 G.global_argv = argv + optind;
8689 G.global_argc = argc - optind;
8691 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8692 const struct built_in_command *x;
8694 install_special_sighandlers();
8695 x = find_builtin(optarg);
8696 if (x) { /* paranoia */
8697 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8698 G.global_argv += builtin_argc;
8699 G.global_argv[-1] = NULL; /* replace "" */
8701 G.last_exitcode = x->b_function(argv + optind - 1);
8705 if (!G.global_argv[0]) {
8706 /* -c 'script' (no params): prevent empty $0 */
8707 G.global_argv--; /* points to argv[i] of 'script' */
8708 G.global_argv[0] = argv[0];
8710 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8711 install_special_sighandlers();
8712 parse_and_run_string(optarg);
8715 /* Well, we cannot just declare interactiveness,
8716 * we have to have some stuff (ctty, etc) */
8717 /* G_interactive_fd++; */
8720 /* "-s" means "read from stdin", but this is how we always
8721 * operate, so simply do nothing here. */
8727 case '<': /* "big heredoc" support */
8728 full_write1_str(optarg);
8731 unsigned long long empty_trap_mask;
8733 G.root_pid = bb_strtou(optarg, &optarg, 16);
8735 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8737 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8739 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8741 builtin_argc = bb_strtou(optarg, &optarg, 16);
8743 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8744 if (empty_trap_mask != 0) {
8745 IF_HUSH_TRAP(int sig;)
8746 install_special_sighandlers();
8747 # if ENABLE_HUSH_TRAP
8748 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8749 for (sig = 1; sig < NSIG; sig++) {
8750 if (empty_trap_mask & (1LL << sig)) {
8751 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8752 install_sighandler(sig, SIG_IGN);
8757 # if ENABLE_HUSH_LOOPS
8759 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8765 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8767 # if ENABLE_HUSH_FUNCTIONS
8769 struct function *funcp = new_function(optarg);
8770 /* funcp->name is already set to optarg */
8771 /* funcp->body is set to NULL. It's a special case. */
8772 funcp->body_as_string = argv[optind];
8781 if (set_mode(1, opt, NULL) == 0) /* no error */
8785 fprintf(stderr, "Usage: sh [FILE]...\n"
8786 " or: sh -c command [args]...\n\n");
8792 } /* option parsing loop */
8794 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8795 G.global_argc = argc - (optind - 1);
8796 G.global_argv = argv + (optind - 1);
8797 G.global_argv[0] = argv[0];
8800 G.root_pid = getpid();
8801 G.root_ppid = getppid();
8804 /* If we are login shell... */
8805 if (flags & OPT_login) {
8807 debug_printf("sourcing /etc/profile\n");
8808 input = fopen_for_read("/etc/profile");
8809 if (input != NULL) {
8810 remember_FILE(input);
8811 install_special_sighandlers();
8812 parse_and_run_file(input);
8813 fclose_and_forget(input);
8815 /* bash: after sourcing /etc/profile,
8816 * tries to source (in the given order):
8817 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8818 * stopping on first found. --noprofile turns this off.
8819 * bash also sources ~/.bash_logout on exit.
8820 * If called as sh, skips .bash_XXX files.
8824 if (G.global_argv[1]) {
8827 * "bash <script>" (which is never interactive (unless -i?))
8828 * sources $BASH_ENV here (without scanning $PATH).
8829 * If called as sh, does the same but with $ENV.
8830 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8834 debug_printf("running script '%s'\n", G.global_argv[0]);
8835 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8836 input = xfopen_for_read(G.global_argv[0]);
8837 xfunc_error_retval = 1;
8838 remember_FILE(input);
8839 install_special_sighandlers();
8840 parse_and_run_file(input);
8841 #if ENABLE_FEATURE_CLEAN_UP
8842 fclose_and_forget(input);
8847 /* Up to here, shell was non-interactive. Now it may become one.
8848 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8851 /* A shell is interactive if the '-i' flag was given,
8852 * or if all of the following conditions are met:
8854 * no arguments remaining or the -s flag given
8855 * standard input is a terminal
8856 * standard output is a terminal
8857 * Refer to Posix.2, the description of the 'sh' utility.
8860 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8861 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8862 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8863 if (G_saved_tty_pgrp < 0)
8864 G_saved_tty_pgrp = 0;
8866 /* try to dup stdin to high fd#, >= 255 */
8867 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8868 if (G_interactive_fd < 0) {
8869 /* try to dup to any fd */
8870 G_interactive_fd = dup(STDIN_FILENO);
8871 if (G_interactive_fd < 0) {
8873 G_interactive_fd = 0;
8874 G_saved_tty_pgrp = 0;
8877 // TODO: track & disallow any attempts of user
8878 // to (inadvertently) close/redirect G_interactive_fd
8880 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8881 if (G_interactive_fd) {
8882 close_on_exec_on(G_interactive_fd);
8884 if (G_saved_tty_pgrp) {
8885 /* If we were run as 'hush &', sleep until we are
8886 * in the foreground (tty pgrp == our pgrp).
8887 * If we get started under a job aware app (like bash),
8888 * make sure we are now in charge so we don't fight over
8889 * who gets the foreground */
8891 pid_t shell_pgrp = getpgrp();
8892 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8893 if (G_saved_tty_pgrp == shell_pgrp)
8895 /* send TTIN to ourself (should stop us) */
8896 kill(- shell_pgrp, SIGTTIN);
8900 /* Install more signal handlers */
8901 install_special_sighandlers();
8903 if (G_saved_tty_pgrp) {
8904 /* Set other signals to restore saved_tty_pgrp */
8905 install_fatal_sighandlers();
8906 /* Put ourselves in our own process group
8907 * (bash, too, does this only if ctty is available) */
8908 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8909 /* Grab control of the terminal */
8910 tcsetpgrp(G_interactive_fd, getpid());
8912 enable_restore_tty_pgrp_on_exit();
8914 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8916 const char *hp = get_local_var_value("HISTFILE");
8918 hp = get_local_var_value("HOME");
8920 hp = concat_path_file(hp, ".hush_history");
8925 G.line_input_state->hist_file = hp;
8926 //set_local_var(xasprintf("HISTFILE=%s", ...));
8928 # if ENABLE_FEATURE_SH_HISTFILESIZE
8929 hp = get_local_var_value("HISTFILESIZE");
8930 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8935 install_special_sighandlers();
8937 #elif ENABLE_HUSH_INTERACTIVE
8938 /* No job control compiled in, only prompt/line editing */
8939 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8940 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8941 if (G_interactive_fd < 0) {
8942 /* try to dup to any fd */
8943 G_interactive_fd = dup(STDIN_FILENO);
8944 if (G_interactive_fd < 0)
8946 G_interactive_fd = 0;
8949 if (G_interactive_fd) {
8950 close_on_exec_on(G_interactive_fd);
8952 install_special_sighandlers();
8954 /* We have interactiveness code disabled */
8955 install_special_sighandlers();
8958 * if interactive but not a login shell, sources ~/.bashrc
8959 * (--norc turns this off, --rcfile <file> overrides)
8962 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8963 /* note: ash and hush share this string */
8964 printf("\n\n%s %s\n"
8965 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8968 "hush - the humble shell"
8972 parse_and_run_file(stdin);
8975 hush_exit(G.last_exitcode);
8982 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8987 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8988 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8990 int argc = string_array_len(argv);
8991 return applet_main_func(argc, argv);
8994 #if ENABLE_HUSH_TEST || BASH_TEST2
8995 static int FAST_FUNC builtin_test(char **argv)
8997 return run_applet_main(argv, test_main);
9000 #if ENABLE_HUSH_ECHO
9001 static int FAST_FUNC builtin_echo(char **argv)
9003 return run_applet_main(argv, echo_main);
9006 #if ENABLE_HUSH_PRINTF
9007 static int FAST_FUNC builtin_printf(char **argv)
9009 return run_applet_main(argv, printf_main);
9013 #if ENABLE_HUSH_HELP
9014 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9016 const struct built_in_command *x;
9019 "Built-in commands:\n"
9020 "------------------\n");
9021 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9023 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9025 return EXIT_SUCCESS;
9029 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9030 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9032 show_history(G.line_input_state);
9033 return EXIT_SUCCESS;
9037 static char **skip_dash_dash(char **argv)
9040 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9045 static int FAST_FUNC builtin_cd(char **argv)
9049 argv = skip_dash_dash(argv);
9051 if (newdir == NULL) {
9052 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9053 * bash says "bash: cd: HOME not set" and does nothing
9056 const char *home = get_local_var_value("HOME");
9057 newdir = home ? home : "/";
9059 if (chdir(newdir)) {
9060 /* Mimic bash message exactly */
9061 bb_perror_msg("cd: %s", newdir);
9062 return EXIT_FAILURE;
9064 /* Read current dir (get_cwd(1) is inside) and set PWD.
9065 * Note: do not enforce exporting. If PWD was unset or unexported,
9066 * set it again, but do not export. bash does the same.
9068 set_pwd_var(/*flag:*/ 0);
9069 return EXIT_SUCCESS;
9072 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9075 return EXIT_SUCCESS;
9078 static int FAST_FUNC builtin_eval(char **argv)
9080 int rcode = EXIT_SUCCESS;
9082 argv = skip_dash_dash(argv);
9084 char *str = expand_strvec_to_string(argv);
9086 * eval "echo Hi; done" ("done" is syntax error):
9087 * "echo Hi" will not execute too.
9089 parse_and_run_string(str);
9091 rcode = G.last_exitcode;
9096 static int FAST_FUNC builtin_exec(char **argv)
9098 argv = skip_dash_dash(argv);
9099 if (argv[0] == NULL)
9100 return EXIT_SUCCESS; /* bash does this */
9102 /* Careful: we can end up here after [v]fork. Do not restore
9103 * tty pgrp then, only top-level shell process does that */
9104 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9105 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9107 /* TODO: if exec fails, bash does NOT exit! We do.
9108 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9109 * and tcsetpgrp, and this is inherently racy.
9111 execvp_or_die(argv);
9114 static int FAST_FUNC builtin_exit(char **argv)
9116 debug_printf_exec("%s()\n", __func__);
9118 /* interactive bash:
9119 * # trap "echo EEE" EXIT
9122 * There are stopped jobs.
9123 * (if there are _stopped_ jobs, running ones don't count)
9126 * EEE (then bash exits)
9128 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9131 /* note: EXIT trap is run by hush_exit */
9132 argv = skip_dash_dash(argv);
9133 if (argv[0] == NULL)
9134 hush_exit(G.last_exitcode);
9135 /* mimic bash: exit 123abc == exit 255 + error msg */
9136 xfunc_error_retval = 255;
9137 /* bash: exit -2 == exit 254, no error msg */
9138 hush_exit(xatoi(argv[0]) & 0xff);
9141 #if ENABLE_HUSH_TYPE
9142 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9143 static int FAST_FUNC builtin_type(char **argv)
9145 int ret = EXIT_SUCCESS;
9151 if (0) {} /* make conditional compile easier below */
9152 /*else if (find_alias(*argv))
9153 type = "an alias";*/
9154 #if ENABLE_HUSH_FUNCTIONS
9155 else if (find_function(*argv))
9156 type = "a function";
9158 else if (find_builtin(*argv))
9159 type = "a shell builtin";
9160 else if ((path = find_in_path(*argv)) != NULL)
9163 bb_error_msg("type: %s: not found", *argv);
9168 printf("%s is %s\n", *argv, type);
9176 #if ENABLE_HUSH_READ
9177 /* Interruptibility of read builtin in bash
9178 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9180 * Empty trap makes read ignore corresponding signal, for any signal.
9183 * - terminates non-interactive shell;
9184 * - interrupts read in interactive shell;
9185 * if it has non-empty trap:
9186 * - executes trap and returns to command prompt in interactive shell;
9187 * - executes trap and returns to read in non-interactive shell;
9189 * - is ignored (does not interrupt) read in interactive shell;
9190 * - terminates non-interactive shell;
9191 * if it has non-empty trap:
9192 * - executes trap and returns to read;
9194 * - terminates shell (regardless of interactivity);
9195 * if it has non-empty trap:
9196 * - executes trap and returns to read;
9197 * SIGCHLD from children:
9198 * - does not interrupt read regardless of interactivity:
9199 * try: sleep 1 & read x; echo $x
9201 static int FAST_FUNC builtin_read(char **argv)
9211 /* "!": do not abort on errors.
9212 * Option string must start with "sr" to match BUILTIN_READ_xxx
9214 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9215 if (read_flags == (uint32_t)-1)
9216 return EXIT_FAILURE;
9218 ifs = get_local_var_value("IFS"); /* can be NULL */
9221 r = shell_builtin_read(set_local_var_from_halves,
9231 if ((uintptr_t)r == 1 && errno == EINTR) {
9232 unsigned sig = check_and_run_traps();
9237 if ((uintptr_t)r > 1) {
9238 bb_error_msg("%s", r);
9239 r = (char*)(uintptr_t)1;
9242 return (uintptr_t)r;
9246 #if ENABLE_HUSH_UMASK
9247 static int FAST_FUNC builtin_umask(char **argv)
9254 argv = skip_dash_dash(argv);
9256 mode_t old_mask = mask;
9258 /* numeric umasks are taken as-is */
9259 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9260 if (!isdigit(argv[0][0]))
9262 mask = bb_parse_mode(argv[0], mask);
9263 if (!isdigit(argv[0][0]))
9265 if ((unsigned)mask > 0777) {
9268 * bash: umask: 'q': invalid symbolic mode operator
9269 * bash: umask: 999: octal number out of range
9271 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9276 printf("%04o\n", (unsigned) mask);
9277 /* fall through and restore mask which we set to 0 */
9281 return !rc; /* rc != 0 - success */
9285 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9286 static void print_escaped(const char *s)
9291 const char *p = strchrnul(s, '\'');
9292 /* print 'xxxx', possibly just '' */
9293 printf("'%.*s'", (int)(p - s), s);
9298 /* s points to '; print "'''...'''" */
9300 do putchar('\''); while (*++s == '\'');
9306 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9307 static int helper_export_local(char **argv, unsigned flags)
9311 char *name_end = strchrnul(name, '=');
9313 /* So far we do not check that name is valid (TODO?) */
9315 if (*name_end == '\0') {
9316 struct variable *var, **vpp;
9318 vpp = get_ptr_to_local_var(name, name_end - name);
9319 var = vpp ? *vpp : NULL;
9321 if (flags & SETFLAG_UNEXPORT) {
9322 /* export -n NAME (without =VALUE) */
9324 var->flg_export = 0;
9325 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9327 } /* else: export -n NOT_EXISTING_VAR: no-op */
9330 if (flags & SETFLAG_EXPORT) {
9331 /* export NAME (without =VALUE) */
9333 var->flg_export = 1;
9334 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9335 putenv(var->varstr);
9339 if (flags & SETFLAG_MAKE_RO) {
9340 /* readonly NAME (without =VALUE) */
9342 var->flg_read_only = 1;
9346 # if ENABLE_HUSH_LOCAL
9347 /* Is this "local" bltin? */
9348 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9349 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9350 if (var && var->func_nest_level == lvl) {
9351 /* "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.
9362 /* Or, it's "local NAME" (without =VALUE).
9363 * bash sets the value to "".
9365 /* Or, it's "readonly NAME" (without =VALUE).
9366 * bash remembers NAME and disallows its creation
9369 name = xasprintf("%s=", name);
9371 /* (Un)exporting/making local NAME=VALUE */
9372 name = xstrdup(name);
9374 if (set_local_var(name, flags))
9375 return EXIT_FAILURE;
9377 return EXIT_SUCCESS;
9381 #if ENABLE_HUSH_EXPORT
9382 static int FAST_FUNC builtin_export(char **argv)
9384 unsigned opt_unexport;
9386 #if ENABLE_HUSH_EXPORT_N
9387 /* "!": do not abort on errors */
9388 opt_unexport = getopt32(argv, "!n");
9389 if (opt_unexport == (uint32_t)-1)
9390 return EXIT_FAILURE;
9397 if (argv[0] == NULL) {
9404 /* ash emits: export VAR='VAL'
9405 * bash: declare -x VAR="VAL"
9406 * we follow ash example */
9407 const char *s = *e++;
9408 const char *p = strchr(s, '=');
9410 if (!p) /* wtf? take next variable */
9413 printf("export %.*s", (int)(p - s) + 1, s);
9414 print_escaped(p + 1);
9418 /*fflush_all(); - done after each builtin anyway */
9420 return EXIT_SUCCESS;
9423 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9427 #if ENABLE_HUSH_LOCAL
9428 static int FAST_FUNC builtin_local(char **argv)
9430 if (G.func_nest_level == 0) {
9431 bb_error_msg("%s: not in a function", argv[0]);
9432 return EXIT_FAILURE; /* bash compat */
9435 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9439 #if ENABLE_HUSH_READONLY
9440 static int FAST_FUNC builtin_readonly(char **argv)
9443 if (*argv == NULL) {
9444 /* bash: readonly [-p]: list all readonly VARs
9445 * (-p has no effect in bash)
9448 for (e = G.top_var; e; e = e->next) {
9449 if (e->flg_read_only) {
9450 //TODO: quote value: readonly VAR='VAL'
9451 printf("readonly %s\n", e->varstr);
9454 return EXIT_SUCCESS;
9456 return helper_export_local(argv, SETFLAG_MAKE_RO);
9460 #if ENABLE_HUSH_UNSET
9461 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9462 static int FAST_FUNC builtin_unset(char **argv)
9467 /* "!": do not abort on errors */
9468 /* "+": stop at 1st non-option */
9469 opts = getopt32(argv, "!+vf");
9470 if (opts == (unsigned)-1)
9471 return EXIT_FAILURE;
9473 bb_error_msg("unset: -v and -f are exclusive");
9474 return EXIT_FAILURE;
9480 if (!(opts & 2)) { /* not -f */
9481 if (unset_local_var(*argv)) {
9482 /* unset <nonexistent_var> doesn't fail.
9483 * Error is when one tries to unset RO var.
9484 * Message was printed by unset_local_var. */
9488 # if ENABLE_HUSH_FUNCTIONS
9500 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9501 * built-in 'set' handler
9503 * set [-abCefhmnuvx] [-o option] [argument...]
9504 * set [+abCefhmnuvx] [+o option] [argument...]
9505 * set -- [argument...]
9508 * Implementations shall support the options in both their hyphen and
9509 * plus-sign forms. These options can also be specified as options to sh.
9511 * Write out all variables and their values: set
9512 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9513 * Turn on the -x and -v options: set -xv
9514 * Unset all positional parameters: set --
9515 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9516 * Set the positional parameters to the expansion of x, even if x expands
9517 * with a leading '-' or '+': set -- $x
9519 * So far, we only support "set -- [argument...]" and some of the short names.
9521 static int FAST_FUNC builtin_set(char **argv)
9524 char **pp, **g_argv;
9525 char *arg = *++argv;
9529 for (e = G.top_var; e; e = e->next)
9531 return EXIT_SUCCESS;
9535 if (strcmp(arg, "--") == 0) {
9539 if (arg[0] != '+' && arg[0] != '-')
9541 for (n = 1; arg[n]; ++n) {
9542 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9544 if (arg[n] == 'o' && argv[1])
9547 } while ((arg = *++argv) != NULL);
9548 /* Now argv[0] is 1st argument */
9551 return EXIT_SUCCESS;
9554 /* NB: G.global_argv[0] ($0) is never freed/changed */
9555 g_argv = G.global_argv;
9556 if (G.global_args_malloced) {
9562 G.global_args_malloced = 1;
9563 pp = xzalloc(sizeof(pp[0]) * 2);
9564 pp[0] = g_argv[0]; /* retain $0 */
9567 /* This realloc's G.global_argv */
9568 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9570 G.global_argc = 1 + string_array_len(pp + 1);
9572 return EXIT_SUCCESS;
9574 /* Nothing known, so abort */
9576 bb_error_msg("set: %s: invalid option", arg);
9577 return EXIT_FAILURE;
9581 static int FAST_FUNC builtin_shift(char **argv)
9584 argv = skip_dash_dash(argv);
9586 n = bb_strtou(argv[0], NULL, 10);
9587 if (errno || n < 0) {
9588 /* shared string with ash.c */
9589 bb_error_msg("Illegal number: %s", argv[0]);
9591 * ash aborts in this case.
9592 * bash prints error message and set $? to 1.
9593 * Interestingly, for "shift 99999" bash does not
9594 * print error message, but does set $? to 1
9595 * (and does no shifting at all).
9599 if (n >= 0 && n < G.global_argc) {
9600 if (G_global_args_malloced) {
9603 free(G.global_argv[m++]);
9606 memmove(&G.global_argv[1], &G.global_argv[n+1],
9607 G.global_argc * sizeof(G.global_argv[0]));
9608 return EXIT_SUCCESS;
9610 return EXIT_FAILURE;
9613 static int FAST_FUNC builtin_source(char **argv)
9615 char *arg_path, *filename;
9618 char *args_need_save;
9619 #if ENABLE_HUSH_FUNCTIONS
9623 argv = skip_dash_dash(argv);
9626 /* bash says: "bash: .: filename argument required" */
9627 return 2; /* bash compat */
9630 if (!strchr(filename, '/')) {
9631 arg_path = find_in_path(filename);
9633 filename = arg_path;
9635 input = remember_FILE(fopen_or_warn(filename, "r"));
9638 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9639 /* POSIX: non-interactive shell should abort here,
9640 * not merely fail. So far no one complained :)
9642 return EXIT_FAILURE;
9645 #if ENABLE_HUSH_FUNCTIONS
9646 sv_flg = G_flag_return_in_progress;
9647 /* "we are inside sourced file, ok to use return" */
9648 G_flag_return_in_progress = -1;
9650 args_need_save = argv[1]; /* used as a boolean variable */
9652 save_and_replace_G_args(&sv, argv);
9654 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9655 G.last_exitcode = 0;
9656 parse_and_run_file(input);
9657 fclose_and_forget(input);
9659 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9660 restore_G_args(&sv, argv);
9661 #if ENABLE_HUSH_FUNCTIONS
9662 G_flag_return_in_progress = sv_flg;
9665 return G.last_exitcode;
9668 #if ENABLE_HUSH_TRAP
9669 static int FAST_FUNC builtin_trap(char **argv)
9675 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9680 /* No args: print all trapped */
9681 for (i = 0; i < NSIG; ++i) {
9684 print_escaped(G_traps[i]);
9685 /* note: bash adds "SIG", but only if invoked
9686 * as "bash". If called as "sh", or if set -o posix,
9687 * then it prints short signal names.
9688 * We are printing short names: */
9689 printf(" %s\n", get_signame(i));
9692 /*fflush_all(); - done after each builtin anyway */
9693 return EXIT_SUCCESS;
9697 /* If first arg is a number: reset all specified signals */
9698 sig = bb_strtou(*argv, NULL, 10);
9704 sighandler_t handler;
9706 sig = get_signum(*argv++);
9707 if (sig < 0 || sig >= NSIG) {
9709 /* Mimic bash message exactly */
9710 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9715 G_traps[sig] = xstrdup(new_cmd);
9717 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9718 get_signame(sig), sig, G_traps[sig]);
9720 /* There is no signal for 0 (EXIT) */
9725 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9727 /* We are removing trap handler */
9728 handler = pick_sighandler(sig);
9729 install_sighandler(sig, handler);
9734 if (!argv[1]) { /* no second arg */
9735 bb_error_msg("trap: invalid arguments");
9736 return EXIT_FAILURE;
9739 /* First arg is "-": reset all specified to default */
9740 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9741 /* Everything else: set arg as signal handler
9742 * (includes "" case, which ignores signal) */
9743 if (argv[0][0] == '-') {
9744 if (argv[0][1] == '\0') { /* "-" */
9745 /* new_cmd remains NULL: "reset these sigs" */
9748 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9751 /* else: "-something", no special meaning */
9756 goto process_sig_list;
9761 static struct pipe *parse_jobspec(const char *str)
9766 if (sscanf(str, "%%%u", &jobnum) != 1) {
9768 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9770 bb_error_msg("bad argument '%s'", str);
9773 /* It is "%%", "%+" or "%" - current job */
9774 jobnum = G.last_jobid;
9776 bb_error_msg("no current job");
9780 for (pi = G.job_list; pi; pi = pi->next) {
9781 if (pi->jobid == jobnum) {
9785 bb_error_msg("%u: no such job", jobnum);
9789 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9792 const char *status_string;
9794 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9795 for (job = G.job_list; job; job = job->next) {
9796 if (job->alive_cmds == job->stopped_cmds)
9797 status_string = "Stopped";
9799 status_string = "Running";
9801 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9804 clean_up_last_dead_job();
9806 return EXIT_SUCCESS;
9809 /* built-in 'fg' and 'bg' handler */
9810 static int FAST_FUNC builtin_fg_bg(char **argv)
9815 if (!G_interactive_fd)
9816 return EXIT_FAILURE;
9818 /* If they gave us no args, assume they want the last backgrounded task */
9820 for (pi = G.job_list; pi; pi = pi->next) {
9821 if (pi->jobid == G.last_jobid) {
9825 bb_error_msg("%s: no current job", argv[0]);
9826 return EXIT_FAILURE;
9829 pi = parse_jobspec(argv[1]);
9831 return EXIT_FAILURE;
9833 /* TODO: bash prints a string representation
9834 * of job being foregrounded (like "sleep 1 | cat") */
9835 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9836 /* Put the job into the foreground. */
9837 tcsetpgrp(G_interactive_fd, pi->pgrp);
9840 /* Restart the processes in the job */
9841 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9842 for (i = 0; i < pi->num_cmds; i++) {
9843 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9845 pi->stopped_cmds = 0;
9847 i = kill(- pi->pgrp, SIGCONT);
9849 if (errno == ESRCH) {
9850 delete_finished_job(pi);
9851 return EXIT_SUCCESS;
9853 bb_perror_msg("kill (SIGCONT)");
9856 if (argv[0][0] == 'f') {
9857 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9858 return checkjobs_and_fg_shell(pi);
9860 return EXIT_SUCCESS;
9864 #if ENABLE_HUSH_KILL
9865 static int FAST_FUNC builtin_kill(char **argv)
9869 # if ENABLE_HUSH_JOB
9870 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9878 if (argv[i][0] != '%')
9881 * "kill %N" - job kill
9882 * Converting to pgrp / pid kill
9884 pi = parse_jobspec(argv[i]);
9886 /* Eat bad jobspec */
9890 argv[j - 1] = argv[j];
9897 * In jobs started under job control, we signal
9898 * entire process group by kill -PGRP_ID.
9899 * This happens, f.e., in interactive shell.
9901 * Otherwise, we signal each child via
9902 * kill PID1 PID2 PID3.
9904 * sh -c 'sleep 1|sleep 1 & kill %1'
9905 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9906 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9908 n = G_interactive_fd ? 1 : pi->num_cmds;
9909 dst = alloca(n * sizeof(int)*4);
9911 if (G_interactive_fd)
9912 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9913 else for (j = 0; j < n; j++) {
9914 struct command *cmd = &pi->cmds[j];
9915 /* Skip exited members of the job */
9919 * kill_main has matching code to expect
9920 * leading space. Needed to not confuse
9921 * negative pids with "kill -SIGNAL_NO" syntax
9923 dst += sprintf(dst, " %u", (int)cmd->pid);
9926 } while (argv[++i]);
9930 if (argv[1] || ret == 0) {
9931 ret = run_applet_main(argv, kill_main);
9933 /* else: ret = 1, "kill %bad_jobspec" case */
9938 #if ENABLE_HUSH_WAIT
9939 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9940 #if !ENABLE_HUSH_JOB
9941 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9943 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9950 if (!sigisemptyset(&G.pending_set))
9953 /* waitpid is not interruptible by SA_RESTARTed
9954 * signals which we use. Thus, this ugly dance:
9957 /* Make sure possible SIGCHLD is stored in kernel's
9958 * pending signal mask before we call waitpid.
9959 * Or else we may race with SIGCHLD, lose it,
9960 * and get stuck in sigsuspend...
9962 sigfillset(&oldset); /* block all signals, remember old set */
9963 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9965 if (!sigisemptyset(&G.pending_set)) {
9966 /* Crap! we raced with some signal! */
9970 /*errno = 0; - checkjobs does this */
9971 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9972 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9973 debug_printf_exec("checkjobs:%d\n", ret);
9976 int rcode = job_exited_or_stopped(waitfor_pipe);
9977 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9980 sigprocmask(SIG_SETMASK, &oldset, NULL);
9985 /* if ECHILD, there are no children (ret is -1 or 0) */
9986 /* if ret == 0, no children changed state */
9987 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9988 if (errno == ECHILD || ret) {
9990 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9992 sigprocmask(SIG_SETMASK, &oldset, NULL);
9995 /* Wait for SIGCHLD or any other signal */
9996 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9997 /* Note: sigsuspend invokes signal handler */
9998 sigsuspend(&oldset);
10000 sigprocmask(SIG_SETMASK, &oldset, NULL);
10002 /* So, did we get a signal? */
10003 sig = check_and_run_traps();
10004 if (sig /*&& sig != SIGCHLD - always true */) {
10008 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10013 static int FAST_FUNC builtin_wait(char **argv)
10018 argv = skip_dash_dash(argv);
10019 if (argv[0] == NULL) {
10020 /* Don't care about wait results */
10021 /* Note 1: must wait until there are no more children */
10022 /* Note 2: must be interruptible */
10024 * $ sleep 3 & sleep 6 & wait
10025 * [1] 30934 sleep 3
10026 * [2] 30935 sleep 6
10029 * $ sleep 3 & sleep 6 & wait
10030 * [1] 30936 sleep 3
10031 * [2] 30937 sleep 6
10033 * ^C <-- after ~4 sec from keyboard
10036 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10040 pid_t pid = bb_strtou(*argv, NULL, 10);
10041 if (errno || pid <= 0) {
10042 #if ENABLE_HUSH_JOB
10043 if (argv[0][0] == '%') {
10044 struct pipe *wait_pipe;
10045 ret = 127; /* bash compat for bad jobspecs */
10046 wait_pipe = parse_jobspec(*argv);
10048 ret = job_exited_or_stopped(wait_pipe);
10050 ret = wait_for_child_or_signal(wait_pipe, 0);
10052 /* waiting on "last dead job" removes it */
10053 clean_up_last_dead_job();
10056 /* else: parse_jobspec() already emitted error msg */
10060 /* mimic bash message */
10061 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10062 ret = EXIT_FAILURE;
10063 continue; /* bash checks all argv[] */
10066 /* Do we have such child? */
10067 ret = waitpid(pid, &status, WNOHANG);
10071 if (errno == ECHILD) {
10072 if (pid == G.last_bg_pid) {
10073 /* "wait $!" but last bg task has already exited. Try:
10074 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10075 * In bash it prints exitcode 0, then 3.
10076 * In dash, it is 127.
10078 ret = G.last_bg_pid_exitcode;
10080 /* Example: "wait 1". mimic bash message */
10081 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10085 bb_perror_msg("wait %s", *argv);
10087 continue; /* bash checks all argv[] */
10090 /* Yes, and it still runs */
10091 ret = wait_for_child_or_signal(NULL, pid);
10093 /* Yes, and it just exited */
10094 process_wait_result(NULL, pid, status);
10095 ret = WEXITSTATUS(status);
10096 if (WIFSIGNALED(status))
10097 ret = 128 + WTERMSIG(status);
10105 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10106 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10109 def = bb_strtou(argv[1], NULL, 10);
10110 if (errno || def < def_min || argv[2]) {
10111 bb_error_msg("%s: bad arguments", argv[0]);
10119 #if ENABLE_HUSH_LOOPS
10120 static int FAST_FUNC builtin_break(char **argv)
10123 if (G.depth_of_loop == 0) {
10124 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10125 /* if we came from builtin_continue(), need to undo "= 1" */
10126 G.flag_break_continue = 0;
10127 return EXIT_SUCCESS; /* bash compat */
10129 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10131 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10132 if (depth == UINT_MAX)
10133 G.flag_break_continue = BC_BREAK;
10134 if (G.depth_of_loop < depth)
10135 G.depth_break_continue = G.depth_of_loop;
10137 return EXIT_SUCCESS;
10140 static int FAST_FUNC builtin_continue(char **argv)
10142 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10143 return builtin_break(argv);
10147 #if ENABLE_HUSH_FUNCTIONS
10148 static int FAST_FUNC builtin_return(char **argv)
10152 if (G_flag_return_in_progress != -1) {
10153 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10154 return EXIT_FAILURE; /* bash compat */
10157 G_flag_return_in_progress = 1;
10160 * out of range: wraps around at 256, does not error out
10161 * non-numeric param:
10162 * f() { false; return qwe; }; f; echo $?
10163 * bash: return: qwe: numeric argument required <== we do this
10164 * 255 <== we also do this
10166 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10171 #if ENABLE_HUSH_MEMLEAK
10172 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10177 # ifdef M_TRIM_THRESHOLD
10178 /* Optional. Reduces probability of false positives */
10181 /* Crude attempt to find where "free memory" starts,
10182 * sans fragmentation. */
10184 l = (unsigned long)p;
10187 if (l < (unsigned long)p) l = (unsigned long)p;
10193 struct mallinfo mi = mallinfo();
10194 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10195 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10199 if (!G.memleak_value)
10200 G.memleak_value = l;
10202 l -= G.memleak_value;
10209 /* Exitcode is "how many kilobytes we leaked since 1st call" */