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 (64 kb)"
107 //config: hush is a small shell. 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 to 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 to finish"),
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 msg_and_die_if_script(lineno, ...) msg_and_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(void)
1285 if (!G_interactive_fd) {
1286 if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
1287 xfunc_error_retval = G.last_exitcode;
1292 static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
1297 bb_error_msg("hush.c:%u", lineno);
1300 bb_verror_msg(fmt, p, NULL);
1305 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1308 bb_error_msg("syntax error: %s", msg);
1310 bb_error_msg("syntax error");
1314 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1316 bb_error_msg("syntax error at '%s'", msg);
1320 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1322 bb_error_msg("syntax error: unterminated %s", s);
1323 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
1327 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1329 char msg[2] = { ch, '\0' };
1330 syntax_error_unterm_str(lineno, msg);
1333 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1339 bb_error_msg("hush.c:%u", lineno);
1341 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1346 # undef msg_and_die_if_script
1347 # undef syntax_error
1348 # undef syntax_error_at
1349 # undef syntax_error_unterm_ch
1350 # undef syntax_error_unterm_str
1351 # undef syntax_error_unexpected_ch
1353 # define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
1354 # define syntax_error(msg) syntax_error(__LINE__, msg)
1355 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1356 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1357 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1358 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1362 #if ENABLE_HUSH_INTERACTIVE
1363 static void cmdedit_update_prompt(void);
1365 # define cmdedit_update_prompt() ((void)0)
1369 /* Utility functions
1371 /* Replace each \x with x in place, return ptr past NUL. */
1372 static char *unbackslash(char *src)
1374 char *dst = src = strchrnul(src, '\\');
1378 if ((*dst++ = *src++) == '\0')
1384 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1405 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1406 v[count1 + count2] = NULL;
1409 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1413 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1415 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1416 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1419 #define add_strings_to_strings(strings, add, need_to_dup) \
1420 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1423 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1424 static char **add_string_to_strings(char **strings, char *add)
1429 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1432 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1434 char **ptr = add_string_to_strings(strings, add);
1435 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1438 #define add_string_to_strings(strings, add) \
1439 xx_add_string_to_strings(__LINE__, strings, add)
1442 static void free_strings(char **strings)
1456 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1460 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1470 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1474 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1480 /* fd was not open? */
1485 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1486 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1492 /* Manipulating the list of open FILEs */
1493 static FILE *remember_FILE(FILE *fp)
1496 struct FILE_list *n = xmalloc(sizeof(*n));
1497 n->next = G.FILE_list;
1501 close_on_exec_on(n->fd);
1505 static void fclose_and_forget(FILE *fp)
1507 struct FILE_list **pp = &G.FILE_list;
1509 struct FILE_list *cur = *pp;
1510 if (cur->fp == fp) {
1519 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1521 struct FILE_list *fl = G.FILE_list;
1524 /* We use it only on script files, they are all CLOEXEC */
1525 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1526 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1533 static void restore_redirected_FILEs(void)
1535 struct FILE_list *fl = G.FILE_list;
1537 int should_be = fileno(fl->fp);
1538 if (fl->fd != should_be) {
1539 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1540 xmove_fd(fl->fd, should_be);
1546 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1547 static void close_all_FILE_list(void)
1549 struct FILE_list *fl = G.FILE_list;
1551 /* fclose would also free FILE object.
1552 * It is disastrous if we share memory with a vforked parent.
1553 * I'm not sure we never come here after vfork.
1554 * Therefore just close fd, nothing more.
1556 /*fclose(fl->fp); - unsafe */
1562 static int fd_in_FILEs(int fd)
1564 struct FILE_list *fl = G.FILE_list;
1574 /* Helpers for setting new $n and restoring them back
1576 typedef struct save_arg_t {
1580 IF_HUSH_SET(smallint sv_g_malloced;)
1583 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1585 sv->sv_argv0 = argv[0];
1586 sv->sv_g_argv = G.global_argv;
1587 sv->sv_g_argc = G.global_argc;
1588 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1590 argv[0] = G.global_argv[0]; /* retain $0 */
1591 G.global_argv = argv;
1592 IF_HUSH_SET(G.global_args_malloced = 0;)
1594 G.global_argc = 1 + string_array_len(argv + 1);
1597 static void restore_G_args(save_arg_t *sv, char **argv)
1600 if (G.global_args_malloced) {
1601 /* someone ran "set -- arg1 arg2 ...", undo */
1602 char **pp = G.global_argv;
1603 while (*++pp) /* note: does not free $0 */
1605 free(G.global_argv);
1608 argv[0] = sv->sv_argv0;
1609 G.global_argv = sv->sv_g_argv;
1610 G.global_argc = sv->sv_g_argc;
1611 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1615 /* Basic theory of signal handling in shell
1616 * ========================================
1617 * This does not describe what hush does, rather, it is current understanding
1618 * what it _should_ do. If it doesn't, it's a bug.
1619 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1621 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1622 * is finished or backgrounded. It is the same in interactive and
1623 * non-interactive shells, and is the same regardless of whether
1624 * a user trap handler is installed or a shell special one is in effect.
1625 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1626 * backgrounds (i.e. stops) or kills all members of currently running
1629 * Wait builtin is interruptible by signals for which user trap is set
1630 * or by SIGINT in interactive shell.
1632 * Trap handlers will execute even within trap handlers. (right?)
1634 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1635 * except for handlers set to '' (empty string).
1637 * If job control is off, backgrounded commands ("cmd &")
1638 * have SIGINT, SIGQUIT set to SIG_IGN.
1640 * Commands which are run in command substitution ("`cmd`")
1641 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1643 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1644 * by the shell from its parent.
1646 * Signals which differ from SIG_DFL action
1647 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1650 * SIGTERM (interactive): ignore
1651 * SIGHUP (interactive):
1652 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1653 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1654 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1655 * that all pipe members are stopped. Try this in bash:
1656 * while :; do :; done - ^Z does not background it
1657 * (while :; do :; done) - ^Z backgrounds it
1658 * SIGINT (interactive): wait for last pipe, ignore the rest
1659 * of the command line, show prompt. NB: ^C does not send SIGINT
1660 * to interactive shell while shell is waiting for a pipe,
1661 * since shell is bg'ed (is not in foreground process group).
1662 * Example 1: this waits 5 sec, but does not execute ls:
1663 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1664 * Example 2: this does not wait and does not execute ls:
1665 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1666 * Example 3: this does not wait 5 sec, but executes ls:
1667 * "sleep 5; ls -l" + press ^C
1668 * Example 4: this does not wait and does not execute ls:
1669 * "sleep 5 & wait; ls -l" + press ^C
1671 * (What happens to signals which are IGN on shell start?)
1672 * (What happens with signal mask on shell start?)
1674 * Old implementation
1675 * ==================
1676 * We use in-kernel pending signal mask to determine which signals were sent.
1677 * We block all signals which we don't want to take action immediately,
1678 * i.e. we block all signals which need to have special handling as described
1679 * above, and all signals which have traps set.
1680 * After each pipe execution, we extract any pending signals via sigtimedwait()
1683 * unsigned special_sig_mask: a mask of such "special" signals
1684 * sigset_t blocked_set: current blocked signal set
1687 * clear bit in blocked_set unless it is also in special_sig_mask
1688 * "trap 'cmd' SIGxxx":
1689 * set bit in blocked_set (even if 'cmd' is '')
1690 * after [v]fork, if we plan to be a shell:
1691 * unblock signals with special interactive handling
1692 * (child shell is not interactive),
1693 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1694 * after [v]fork, if we plan to exec:
1695 * POSIX says fork clears pending signal mask in child - no need to clear it.
1696 * Restore blocked signal set to one inherited by shell just prior to exec.
1698 * Note: as a result, we do not use signal handlers much. The only uses
1699 * are to count SIGCHLDs
1700 * and to restore tty pgrp on signal-induced exit.
1703 * Standard says "When a subshell is entered, traps that are not being ignored
1704 * are set to the default actions". bash interprets it so that traps which
1705 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1707 * Problem: the above approach makes it unwieldy to catch signals while
1708 * we are in read builtin, or while we read commands from stdin:
1709 * masked signals are not visible!
1711 * New implementation
1712 * ==================
1713 * We record each signal we are interested in by installing signal handler
1714 * for them - a bit like emulating kernel pending signal mask in userspace.
1715 * We are interested in: signals which need to have special handling
1716 * as described above, and all signals which have traps set.
1717 * Signals are recorded in pending_set.
1718 * After each pipe execution, we extract any pending signals
1721 * unsigned special_sig_mask: a mask of shell-special signals.
1722 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1723 * char *traps[sig] if trap for sig is set (even if it's '').
1724 * sigset_t pending_set: set of sigs we received.
1727 * if sig is in special_sig_mask, set handler back to:
1728 * record_pending_signo, or to IGN if it's a tty stop signal
1729 * if sig is in fatal_sig_mask, set handler back to sigexit.
1730 * else: set handler back to SIG_DFL
1731 * "trap 'cmd' SIGxxx":
1732 * set handler to record_pending_signo.
1734 * set handler to SIG_IGN.
1735 * after [v]fork, if we plan to be a shell:
1736 * set signals with special interactive handling to SIG_DFL
1737 * (because child shell is not interactive),
1738 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1739 * after [v]fork, if we plan to exec:
1740 * POSIX says fork clears pending signal mask in child - no need to clear it.
1742 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1743 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1746 * Standard says "When a subshell is entered, traps that are not being ignored
1747 * are set to the default actions". bash interprets it so that traps which
1748 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1751 SPECIAL_INTERACTIVE_SIGS = 0
1756 SPECIAL_JOBSTOP_SIGS = 0
1765 static void record_pending_signo(int sig)
1767 sigaddset(&G.pending_set, sig);
1768 #if ENABLE_HUSH_FAST
1769 if (sig == SIGCHLD) {
1771 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1776 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1778 struct sigaction old_sa;
1780 /* We could use signal() to install handlers... almost:
1781 * except that we need to mask ALL signals while handlers run.
1782 * I saw signal nesting in strace, race window isn't small.
1783 * SA_RESTART is also needed, but in Linux, signal()
1784 * sets SA_RESTART too.
1786 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1787 /* sigfillset(&G.sa.sa_mask); - already done */
1788 /* G.sa.sa_flags = SA_RESTART; - already done */
1789 G.sa.sa_handler = handler;
1790 sigaction(sig, &G.sa, &old_sa);
1791 return old_sa.sa_handler;
1794 static void hush_exit(int exitcode) NORETURN;
1796 static void restore_ttypgrp_and__exit(void) NORETURN;
1797 static void restore_ttypgrp_and__exit(void)
1799 /* xfunc has failed! die die die */
1800 /* no EXIT traps, this is an escape hatch! */
1802 hush_exit(xfunc_error_retval);
1807 /* Needed only on some libc:
1808 * It was observed that on exit(), fgetc'ed buffered data
1809 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1810 * With the net effect that even after fork(), not vfork(),
1811 * exit() in NOEXECed applet in "sh SCRIPT":
1812 * noexec_applet_here
1813 * echo END_OF_SCRIPT
1814 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1815 * This makes "echo END_OF_SCRIPT" executed twice.
1816 * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
1817 * and in `cmd` handling.
1818 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1820 static void fflush_and__exit(void) NORETURN;
1821 static void fflush_and__exit(void)
1824 _exit(xfunc_error_retval);
1827 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1828 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1829 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1830 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1832 /* Restores tty foreground process group, and exits.
1833 * May be called as signal handler for fatal signal
1834 * (will resend signal to itself, producing correct exit state)
1835 * or called directly with -EXITCODE.
1836 * We also call it if xfunc is exiting.
1838 static void sigexit(int sig) NORETURN;
1839 static void sigexit(int sig)
1841 /* Careful: we can end up here after [v]fork. Do not restore
1842 * tty pgrp then, only top-level shell process does that */
1843 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1844 /* Disable all signals: job control, SIGPIPE, etc.
1845 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1847 sigprocmask_allsigs(SIG_BLOCK);
1848 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1851 /* Not a signal, just exit */
1855 kill_myself_with_sig(sig); /* does not return */
1859 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1860 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1864 static sighandler_t pick_sighandler(unsigned sig)
1866 sighandler_t handler = SIG_DFL;
1867 if (sig < sizeof(unsigned)*8) {
1868 unsigned sigmask = (1 << sig);
1872 if (G_fatal_sig_mask & sigmask)
1876 /* sig has special handling? */
1877 if (G.special_sig_mask & sigmask) {
1878 handler = record_pending_signo;
1879 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1880 * in order to ignore them: they will be raised
1881 * in an endless loop when we try to do some
1882 * terminal ioctls! We do have to _ignore_ these.
1884 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1891 /* Restores tty foreground process group, and exits. */
1892 static void hush_exit(int exitcode)
1894 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1895 save_history(G.line_input_state);
1899 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1901 /* argv[0] is unused */
1902 argv[1] = G_traps[0];
1904 G.exiting = 1; /* prevent EXIT trap recursion */
1905 /* Note: G_traps[0] is not cleared!
1906 * "trap" will still show it, if executed
1911 #if ENABLE_FEATURE_CLEAN_UP
1913 struct variable *cur_var;
1914 if (G.cwd != bb_msg_unknown)
1916 cur_var = G.top_var;
1918 struct variable *tmp = cur_var;
1919 if (!cur_var->max_len)
1920 free(cur_var->varstr);
1921 cur_var = cur_var->next;
1929 sigexit(- (exitcode & 0xff));
1936 //TODO: return a mask of ALL handled sigs?
1937 static int check_and_run_traps(void)
1944 if (sigisemptyset(&G.pending_set))
1949 if (sigismember(&G.pending_set, sig)) {
1950 sigdelset(&G.pending_set, sig);
1953 } while (sig < NSIG);
1956 if (G_traps && G_traps[sig]) {
1957 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1958 if (G_traps[sig][0]) {
1959 /* We have user-defined handler */
1960 smalluint save_rcode;
1962 /* argv[0] is unused */
1963 argv[1] = G_traps[sig];
1965 save_rcode = G.last_exitcode;
1967 //FIXME: shouldn't it be set to 128 + sig instead?
1968 G.last_exitcode = save_rcode;
1970 } /* else: "" trap, ignoring signal */
1973 /* not a trap: special action */
1976 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1982 //TODO: why are we doing this? ash and dash don't do this,
1983 //they have no handler for SIGHUP at all,
1984 //they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
1986 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1987 /* bash is observed to signal whole process groups,
1988 * not individual processes */
1989 for (job = G.job_list; job; job = job->next) {
1992 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1993 if (kill(- job->pgrp, SIGHUP) == 0)
1994 kill(- job->pgrp, SIGCONT);
1999 #if ENABLE_HUSH_FAST
2001 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
2003 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2005 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2006 * This simplifies wait builtin a bit.
2010 default: /* ignored: */
2011 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
2012 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
2014 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2015 * Example: wait is not interrupted by TERM
2016 * in interactive shell, because TERM is ignored.
2025 static const char *get_cwd(int force)
2027 if (force || G.cwd == NULL) {
2028 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2029 * we must not try to free(bb_msg_unknown) */
2030 if (G.cwd == bb_msg_unknown)
2032 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2034 G.cwd = bb_msg_unknown;
2041 * Shell and environment variable support
2043 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2045 struct variable **pp;
2046 struct variable *cur;
2049 while ((cur = *pp) != NULL) {
2050 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2057 static const char* FAST_FUNC get_local_var_value(const char *name)
2059 struct variable **vpp;
2060 unsigned len = strlen(name);
2062 if (G.expanded_assignments) {
2063 char **cpp = G.expanded_assignments;
2066 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2067 return cp + len + 1;
2072 vpp = get_ptr_to_local_var(name, len);
2074 return (*vpp)->varstr + len + 1;
2076 if (strcmp(name, "PPID") == 0)
2077 return utoa(G.root_ppid);
2078 // bash compat: UID? EUID?
2079 #if ENABLE_HUSH_RANDOM_SUPPORT
2080 if (strcmp(name, "RANDOM") == 0)
2081 return utoa(next_random(&G.random_gen));
2086 /* str holds "NAME=VAL" and is expected to be malloced.
2087 * We take ownership of it.
2089 #define SETFLAG_EXPORT (1 << 0)
2090 #define SETFLAG_UNEXPORT (1 << 1)
2091 #define SETFLAG_MAKE_RO (1 << 2)
2092 #define SETFLAG_LOCAL_SHIFT 3
2093 static int set_local_var(char *str, unsigned flags)
2095 struct variable **var_pp;
2096 struct variable *cur;
2097 char *free_me = NULL;
2100 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2102 eq_sign = strchr(str, '=');
2103 if (!eq_sign) { /* not expected to ever happen? */
2108 name_len = eq_sign - str + 1; /* including '=' */
2109 var_pp = &G.top_var;
2110 while ((cur = *var_pp) != NULL) {
2111 if (strncmp(cur->varstr, str, name_len) != 0) {
2112 var_pp = &cur->next;
2116 /* We found an existing var with this name */
2117 if (cur->flg_read_only) {
2118 bb_error_msg("%s: readonly variable", str);
2120 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2121 //but export per se succeeds (does put the var in env). We don't mimic that.
2124 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2125 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2130 #if ENABLE_HUSH_LOCAL
2131 if (cur->func_nest_level < local_lvl) {
2132 /* New variable is declared as local,
2133 * and existing one is global, or local
2134 * from enclosing function.
2135 * Remove and save old one: */
2136 *var_pp = cur->next;
2137 cur->next = *G.shadowed_vars_pp;
2138 *G.shadowed_vars_pp = cur;
2139 /* bash 3.2.33(1) and exported vars:
2141 * # f() { local z=a; env | grep ^z; }
2147 if (cur->flg_export)
2148 flags |= SETFLAG_EXPORT;
2152 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2157 if (cur->max_len != 0) {
2158 if (cur->max_len >= strlen(str)) {
2159 /* This one is from startup env, reuse space */
2160 strcpy(cur->varstr, str);
2165 goto set_str_and_exp;
2167 /* max_len == 0 signifies "malloced" var, which we can
2168 * (and have to) free. But we can't free(cur->varstr) here:
2169 * if cur->flg_export is 1, it is in the environment.
2170 * We should either unsetenv+free, or wait until putenv,
2171 * then putenv(new)+free(old).
2173 free_me = cur->varstr;
2174 goto set_str_and_exp;
2177 /* Not found - create new variable struct */
2178 cur = xzalloc(sizeof(*cur));
2179 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2180 cur->next = *var_pp;
2186 #if !BB_MMU || ENABLE_HUSH_READONLY
2187 if (flags & SETFLAG_MAKE_RO) {
2188 cur->flg_read_only = 1;
2191 if (flags & SETFLAG_EXPORT)
2192 cur->flg_export = 1;
2193 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2194 cmdedit_update_prompt();
2195 if (cur->flg_export) {
2196 if (flags & SETFLAG_UNEXPORT) {
2197 cur->flg_export = 0;
2198 /* unsetenv was already done */
2201 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2202 i = putenv(cur->varstr);
2203 /* only now we can free old exported malloced string */
2212 /* Used at startup and after each cd */
2213 static void set_pwd_var(unsigned flag)
2215 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2218 static int unset_local_var_len(const char *name, int name_len)
2220 struct variable *cur;
2221 struct variable **var_pp;
2224 return EXIT_SUCCESS;
2225 var_pp = &G.top_var;
2226 while ((cur = *var_pp) != NULL) {
2227 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2228 if (cur->flg_read_only) {
2229 bb_error_msg("%s: readonly variable", name);
2230 return EXIT_FAILURE;
2232 *var_pp = cur->next;
2233 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2234 bb_unsetenv(cur->varstr);
2235 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2236 cmdedit_update_prompt();
2240 return EXIT_SUCCESS;
2242 var_pp = &cur->next;
2244 return EXIT_SUCCESS;
2247 #if ENABLE_HUSH_UNSET
2248 static int unset_local_var(const char *name)
2250 return unset_local_var_len(name, strlen(name));
2254 static void unset_vars(char **strings)
2262 const char *eq = strchrnul(*v, '=');
2263 unset_local_var_len(*v, (int)(eq - *v));
2269 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2270 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2272 char *var = xasprintf("%s=%s", name, val);
2273 set_local_var(var, /*flag:*/ 0);
2279 * Helpers for "var1=val1 var2=val2 cmd" feature
2281 static void add_vars(struct variable *var)
2283 struct variable *next;
2287 var->next = G.top_var;
2289 if (var->flg_export) {
2290 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2291 putenv(var->varstr);
2293 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2299 static struct variable *set_vars_and_save_old(char **strings)
2302 struct variable *old = NULL;
2308 struct variable *var_p;
2309 struct variable **var_pp;
2312 eq = strchr(*s, '=');
2314 var_pp = get_ptr_to_local_var(*s, eq - *s);
2317 if (var_p->flg_read_only) {
2319 bb_error_msg("%s: readonly variable", *s);
2321 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2322 * If VAR is readonly, leaving it in the list
2323 * after asssignment error (msg above)
2324 * causes doubled error message later, on unset.
2326 debug_printf_env("removing/freeing '%s' element\n", *s);
2329 do { *p = p[1]; p++; } while (*p);
2332 /* Remove variable from global linked list */
2333 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2334 *var_pp = var_p->next;
2335 /* Add it to returned list */
2339 set_local_var(*s, SETFLAG_EXPORT);
2351 static void reinit_unicode_for_hush(void)
2353 /* Unicode support should be activated even if LANG is set
2354 * _during_ shell execution, not only if it was set when
2355 * shell was started. Therefore, re-check LANG every time:
2357 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2358 || ENABLE_UNICODE_USING_LOCALE
2360 const char *s = get_local_var_value("LC_ALL");
2361 if (!s) s = get_local_var_value("LC_CTYPE");
2362 if (!s) s = get_local_var_value("LANG");
2368 * in_str support (strings, and "strings" read from files).
2371 #if ENABLE_HUSH_INTERACTIVE
2372 /* To test correct lineedit/interactive behavior, type from command line:
2378 * It exercises a lot of corner cases.
2380 static void cmdedit_update_prompt(void)
2382 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2383 G.PS1 = get_local_var_value("PS1");
2386 G.PS2 = get_local_var_value("PS2");
2393 static const char *setup_prompt_string(int promptmode)
2395 const char *prompt_str;
2396 debug_printf("setup_prompt_string %d ", promptmode);
2397 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2398 /* Set up the prompt */
2399 if (promptmode == 0) { /* PS1 */
2401 /* bash uses $PWD value, even if it is set by user.
2402 * It uses current dir only if PWD is unset.
2403 * We always use current dir. */
2404 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2409 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2410 debug_printf("prompt_str '%s'\n", prompt_str);
2413 static int get_user_input(struct in_str *i)
2416 const char *prompt_str;
2418 prompt_str = setup_prompt_string(i->promptmode);
2419 # if ENABLE_FEATURE_EDITING
2421 reinit_unicode_for_hush();
2422 if (G.flag_SIGINT) {
2423 /* There was ^C'ed, make it look prettier: */
2427 /* buglet: SIGINT will not make new prompt to appear _at once_,
2428 * only after <Enter>. (^C works immediately) */
2429 r = read_line_input(G.line_input_state, prompt_str,
2430 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
2432 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2435 check_and_run_traps();
2436 if (r != 0 && !G.flag_SIGINT)
2438 /* ^C or SIGINT: repeat */
2439 /* bash prints ^C even on real SIGINT (non-kbd generated) */
2440 write(STDOUT_FILENO, "^C", 2);
2441 G.last_exitcode = 128 + SIGINT;
2444 /* EOF/error detected */
2446 i->peek_buf[0] = r = EOF;
2449 i->p = G.user_input_buf;
2450 return (unsigned char)*i->p++;
2454 if (i->last_char == '\0' || i->last_char == '\n') {
2455 /* Why check_and_run_traps here? Try this interactively:
2456 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2457 * $ <[enter], repeatedly...>
2458 * Without check_and_run_traps, handler never runs.
2460 check_and_run_traps();
2461 fputs(prompt_str, stdout);
2464 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2466 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2467 * no ^C masking happens during fgetc, no special code for ^C:
2468 * it generates SIGINT as usual.
2470 check_and_run_traps();
2472 G.last_exitcode = 128 + SIGINT;
2479 /* This is the magic location that prints prompts
2480 * and gets data back from the user */
2481 static int fgetc_interactive(struct in_str *i)
2484 /* If it's interactive stdin, get new line. */
2485 if (G_interactive_fd && i->file == stdin) {
2486 /* Returns first char (or EOF), the rest is in i->p[] */
2487 ch = get_user_input(i);
2488 i->promptmode = 1; /* PS2 */
2490 /* Not stdin: script file, sourced file, etc */
2491 do ch = fgetc(i->file); while (ch == '\0');
2496 static inline int fgetc_interactive(struct in_str *i)
2499 do ch = fgetc(i->file); while (ch == '\0');
2502 #endif /* INTERACTIVE */
2504 static int i_getch(struct in_str *i)
2509 /* string-based in_str */
2510 ch = (unsigned char)*i->p;
2519 /* FILE-based in_str */
2521 #if ENABLE_FEATURE_EDITING
2522 /* This can be stdin, check line editing char[] buffer */
2523 if (i->p && *i->p != '\0') {
2524 ch = (unsigned char)*i->p++;
2528 /* peek_buf[] is an int array, not char. Can contain EOF. */
2529 ch = i->peek_buf[0];
2531 int ch2 = i->peek_buf[1];
2532 i->peek_buf[0] = ch2;
2533 if (ch2 == 0) /* very likely, avoid redundant write */
2539 ch = fgetc_interactive(i);
2541 debug_printf("file_get: got '%c' %d\n", ch, ch);
2546 static int i_peek(struct in_str *i)
2551 /* string-based in_str */
2552 /* Doesn't report EOF on NUL. None of the callers care. */
2553 return (unsigned char)*i->p;
2556 /* FILE-based in_str */
2558 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2559 /* This can be stdin, check line editing char[] buffer */
2560 if (i->p && *i->p != '\0')
2561 return (unsigned char)*i->p;
2563 /* peek_buf[] is an int array, not char. Can contain EOF. */
2564 ch = i->peek_buf[0];
2568 /* Need to get a new char */
2569 ch = fgetc_interactive(i);
2570 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2572 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2573 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2579 i->peek_buf[0] = ch;
2580 /*i->peek_buf[1] = 0; - already is */
2584 /* Only ever called if i_peek() was called, and did not return EOF.
2585 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2586 * not end-of-line. Therefore we never need to read a new editing line here.
2588 static int i_peek2(struct in_str *i)
2592 /* There are two cases when i->p[] buffer exists.
2593 * (1) it's a string in_str.
2594 * (2) It's a file, and we have a saved line editing buffer.
2595 * In both cases, we know that i->p[0] exists and not NUL, and
2596 * the peek2 result is in i->p[1].
2599 return (unsigned char)i->p[1];
2601 /* Now we know it is a file-based in_str. */
2603 /* peek_buf[] is an int array, not char. Can contain EOF. */
2604 /* Is there 2nd char? */
2605 ch = i->peek_buf[1];
2607 /* We did not read it yet, get it now */
2608 do ch = fgetc(i->file); while (ch == '\0');
2609 i->peek_buf[1] = ch;
2612 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2616 static void setup_file_in_str(struct in_str *i, FILE *f)
2618 memset(i, 0, sizeof(*i));
2619 /* i->promptmode = 0; - PS1 (memset did it) */
2624 static void setup_string_in_str(struct in_str *i, const char *s)
2626 memset(i, 0, sizeof(*i));
2627 /* i->promptmode = 0; - PS1 (memset did it) */
2628 /*i->file = NULL */;
2636 #define B_CHUNK (32 * sizeof(char*))
2638 static void o_reset_to_empty_unquoted(o_string *o)
2641 o->has_quoted_part = 0;
2646 static void o_free(o_string *o)
2649 memset(o, 0, sizeof(*o));
2652 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2657 static void o_grow_by(o_string *o, int len)
2659 if (o->length + len > o->maxlen) {
2660 o->maxlen += (2 * len) | (B_CHUNK-1);
2661 o->data = xrealloc(o->data, 1 + o->maxlen);
2665 static void o_addchr(o_string *o, int ch)
2667 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2668 if (o->length < o->maxlen) {
2669 /* likely. avoid o_grow_by() call */
2671 o->data[o->length] = ch;
2673 o->data[o->length] = '\0';
2681 /* Valid only if we know o_string is not empty */
2682 static void o_delchr(o_string *o)
2685 o->data[o->length] = '\0';
2689 static void o_addblock(o_string *o, const char *str, int len)
2692 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2696 static void o_addstr(o_string *o, const char *str)
2698 o_addblock(o, str, strlen(str));
2702 static void nommu_addchr(o_string *o, int ch)
2708 # define nommu_addchr(o, str) ((void)0)
2711 static void o_addstr_with_NUL(o_string *o, const char *str)
2713 o_addblock(o, str, strlen(str) + 1);
2717 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2718 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2719 * Apparently, on unquoted $v bash still does globbing
2720 * ("v='*.txt'; echo $v" prints all .txt files),
2721 * but NOT brace expansion! Thus, there should be TWO independent
2722 * quoting mechanisms on $v expansion side: one protects
2723 * $v from brace expansion, and other additionally protects "$v" against globbing.
2724 * We have only second one.
2727 #if ENABLE_HUSH_BRACE_EXPANSION
2728 # define MAYBE_BRACES "{}"
2730 # define MAYBE_BRACES ""
2733 /* My analysis of quoting semantics tells me that state information
2734 * is associated with a destination, not a source.
2736 static void o_addqchr(o_string *o, int ch)
2739 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2744 o->data[o->length] = '\\';
2747 o->data[o->length] = ch;
2749 o->data[o->length] = '\0';
2752 static void o_addQchr(o_string *o, int ch)
2755 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2756 && strchr("*?[\\" MAYBE_BRACES, ch)
2759 o->data[o->length] = '\\';
2763 o->data[o->length] = ch;
2765 o->data[o->length] = '\0';
2768 static void o_addqblock(o_string *o, const char *str, int len)
2773 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2774 if (ordinary_cnt > len) /* paranoia */
2776 o_addblock(o, str, ordinary_cnt);
2777 if (ordinary_cnt == len)
2778 return; /* NUL is already added by o_addblock */
2779 str += ordinary_cnt;
2780 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2784 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2786 o->data[o->length] = '\\';
2790 o->data[o->length] = ch;
2793 o->data[o->length] = '\0';
2796 static void o_addQblock(o_string *o, const char *str, int len)
2798 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2799 o_addblock(o, str, len);
2802 o_addqblock(o, str, len);
2805 static void o_addQstr(o_string *o, const char *str)
2807 o_addQblock(o, str, strlen(str));
2810 /* A special kind of o_string for $VAR and `cmd` expansion.
2811 * It contains char* list[] at the beginning, which is grown in 16 element
2812 * increments. Actual string data starts at the next multiple of 16 * (char*).
2813 * list[i] contains an INDEX (int!) into this string data.
2814 * It means that if list[] needs to grow, data needs to be moved higher up
2815 * but list[i]'s need not be modified.
2816 * NB: remembering how many list[i]'s you have there is crucial.
2817 * o_finalize_list() operation post-processes this structure - calculates
2818 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2820 #if DEBUG_EXPAND || DEBUG_GLOB
2821 static void debug_print_list(const char *prefix, o_string *o, int n)
2823 char **list = (char**)o->data;
2824 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2828 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2829 prefix, list, n, string_start, o->length, o->maxlen,
2830 !!(o->o_expflags & EXP_FLAG_GLOB),
2832 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2835 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2836 o->data + (int)(uintptr_t)list[i] + string_start,
2837 o->data + (int)(uintptr_t)list[i] + string_start);
2841 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2843 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2847 # define debug_print_list(prefix, o, n) ((void)0)
2850 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2851 * in list[n] so that it points past last stored byte so far.
2852 * It returns n+1. */
2853 static int o_save_ptr_helper(o_string *o, int n)
2855 char **list = (char**)o->data;
2859 if (!o->has_empty_slot) {
2860 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2861 string_len = o->length - string_start;
2862 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2863 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2864 /* list[n] points to string_start, make space for 16 more pointers */
2865 o->maxlen += 0x10 * sizeof(list[0]);
2866 o->data = xrealloc(o->data, o->maxlen + 1);
2867 list = (char**)o->data;
2868 memmove(list + n + 0x10, list + n, string_len);
2869 o->length += 0x10 * sizeof(list[0]);
2871 debug_printf_list("list[%d]=%d string_start=%d\n",
2872 n, string_len, string_start);
2875 /* We have empty slot at list[n], reuse without growth */
2876 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2877 string_len = o->length - string_start;
2878 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2879 n, string_len, string_start);
2880 o->has_empty_slot = 0;
2882 o->has_quoted_part = 0;
2883 list[n] = (char*)(uintptr_t)string_len;
2887 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2888 static int o_get_last_ptr(o_string *o, int n)
2890 char **list = (char**)o->data;
2891 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2893 return ((int)(uintptr_t)list[n-1]) + string_start;
2896 #if ENABLE_HUSH_BRACE_EXPANSION
2897 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2898 * first, it processes even {a} (no commas), second,
2899 * I didn't manage to make it return strings when they don't match
2900 * existing files. Need to re-implement it.
2904 static int glob_needed(const char *s)
2913 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2919 /* Return pointer to next closing brace or to comma */
2920 static const char *next_brace_sub(const char *cp)
2924 while (*cp != '\0') {
2931 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2937 return *cp != '\0' ? cp : NULL;
2939 /* Recursive brace globber. Note: may garble pattern[]. */
2940 static int glob_brace(char *pattern, o_string *o, int n)
2942 char *new_pattern_buf;
2949 debug_printf_glob("glob_brace('%s')\n", pattern);
2955 if (*begin == '{') {
2956 /* Find the first sub-pattern and at the same time
2957 * find the rest after the closing brace */
2958 next = next_brace_sub(begin);
2960 /* An illegal expression */
2964 /* "{abc}" with no commas - illegal
2965 * brace expr, disregard and skip it */
2971 if (*begin == '\\' && begin[1] != '\0')
2975 debug_printf_glob("begin:%s\n", begin);
2976 debug_printf_glob("next:%s\n", next);
2978 /* Now find the end of the whole brace expression */
2980 while (*rest != '}') {
2981 rest = next_brace_sub(rest);
2983 /* An illegal expression */
2986 debug_printf_glob("rest:%s\n", rest);
2988 rest_len = strlen(++rest) + 1;
2990 /* We are sure the brace expression is well-formed */
2992 /* Allocate working buffer large enough for our work */
2993 new_pattern_buf = xmalloc(strlen(pattern));
2995 /* We have a brace expression. BEGIN points to the opening {,
2996 * NEXT points past the terminator of the first element, and REST
2997 * points past the final }. We will accumulate result names from
2998 * recursive runs for each brace alternative in the buffer using
3003 /* Construct the new glob expression */
3006 mempcpy(new_pattern_buf,
3007 /* We know the prefix for all sub-patterns */
3008 pattern, begin - pattern),
3012 /* Note: glob_brace() may garble new_pattern_buf[].
3013 * That's why we re-copy prefix every time (1st memcpy above).
3015 n = glob_brace(new_pattern_buf, o, n);
3017 /* We saw the last entry */
3021 next = next_brace_sub(next);
3023 free(new_pattern_buf);
3031 memset(&globdata, 0, sizeof(globdata));
3032 gr = glob(pattern, 0, NULL, &globdata);
3033 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3035 if (gr == GLOB_NOMATCH) {
3036 globfree(&globdata);
3037 /* NB: garbles parameter */
3038 unbackslash(pattern);
3039 o_addstr_with_NUL(o, pattern);
3040 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3041 return o_save_ptr_helper(o, n);
3043 if (gr == GLOB_NOSPACE)
3044 bb_error_msg_and_die(bb_msg_memory_exhausted);
3045 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3046 * but we didn't specify it. Paranoia again. */
3047 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3049 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3050 char **argv = globdata.gl_pathv;
3052 o_addstr_with_NUL(o, *argv);
3053 n = o_save_ptr_helper(o, n);
3059 globfree(&globdata);
3063 /* Performs globbing on last list[],
3064 * saving each result as a new list[].
3066 static int perform_glob(o_string *o, int n)
3068 char *pattern, *copy;
3070 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3072 return o_save_ptr_helper(o, n);
3073 pattern = o->data + o_get_last_ptr(o, n);
3074 debug_printf_glob("glob pattern '%s'\n", pattern);
3075 if (!glob_needed(pattern)) {
3076 /* unbackslash last string in o in place, fix length */
3077 o->length = unbackslash(pattern) - o->data;
3078 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3079 return o_save_ptr_helper(o, n);
3082 copy = xstrdup(pattern);
3083 /* "forget" pattern in o */
3084 o->length = pattern - o->data;
3085 n = glob_brace(copy, o, n);
3088 debug_print_list("perform_glob returning", o, n);
3092 #else /* !HUSH_BRACE_EXPANSION */
3095 static int glob_needed(const char *s)
3104 if (*s == '*' || *s == '[' || *s == '?')
3110 /* Performs globbing on last list[],
3111 * saving each result as a new list[].
3113 static int perform_glob(o_string *o, int n)
3119 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3121 return o_save_ptr_helper(o, n);
3122 pattern = o->data + o_get_last_ptr(o, n);
3123 debug_printf_glob("glob pattern '%s'\n", pattern);
3124 if (!glob_needed(pattern)) {
3126 /* unbackslash last string in o in place, fix length */
3127 o->length = unbackslash(pattern) - o->data;
3128 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3129 return o_save_ptr_helper(o, n);
3132 memset(&globdata, 0, sizeof(globdata));
3133 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3134 * If we glob "*.\*" and don't find anything, we need
3135 * to fall back to using literal "*.*", but GLOB_NOCHECK
3136 * will return "*.\*"!
3138 gr = glob(pattern, 0, NULL, &globdata);
3139 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3141 if (gr == GLOB_NOMATCH) {
3142 globfree(&globdata);
3145 if (gr == GLOB_NOSPACE)
3146 bb_error_msg_and_die(bb_msg_memory_exhausted);
3147 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3148 * but we didn't specify it. Paranoia again. */
3149 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3151 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3152 char **argv = globdata.gl_pathv;
3153 /* "forget" pattern in o */
3154 o->length = pattern - o->data;
3156 o_addstr_with_NUL(o, *argv);
3157 n = o_save_ptr_helper(o, n);
3163 globfree(&globdata);
3165 debug_print_list("perform_glob returning", o, n);
3169 #endif /* !HUSH_BRACE_EXPANSION */
3171 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3172 * Otherwise, just finish current list[] and start new */
3173 static int o_save_ptr(o_string *o, int n)
3175 if (o->o_expflags & EXP_FLAG_GLOB) {
3176 /* If o->has_empty_slot, list[n] was already globbed
3177 * (if it was requested back then when it was filled)
3178 * so don't do that again! */
3179 if (!o->has_empty_slot)
3180 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3182 return o_save_ptr_helper(o, n);
3185 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3186 static char **o_finalize_list(o_string *o, int n)
3191 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3193 debug_print_list("finalized", o, n);
3194 debug_printf_expand("finalized n:%d\n", n);
3195 list = (char**)o->data;
3196 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3200 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3205 static void free_pipe_list(struct pipe *pi);
3207 /* Returns pi->next - next pipe in the list */
3208 static struct pipe *free_pipe(struct pipe *pi)
3213 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3214 for (i = 0; i < pi->num_cmds; i++) {
3215 struct command *command;
3216 struct redir_struct *r, *rnext;
3218 command = &pi->cmds[i];
3219 debug_printf_clean(" command %d:\n", i);
3220 if (command->argv) {
3224 for (a = 0, p = command->argv; *p; a++, p++) {
3225 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3228 free_strings(command->argv);
3229 //command->argv = NULL;
3231 /* not "else if": on syntax error, we may have both! */
3232 if (command->group) {
3233 debug_printf_clean(" begin group (cmd_type:%d)\n",
3235 free_pipe_list(command->group);
3236 debug_printf_clean(" end group\n");
3237 //command->group = NULL;
3239 /* else is crucial here.
3240 * If group != NULL, child_func is meaningless */
3241 #if ENABLE_HUSH_FUNCTIONS
3242 else if (command->child_func) {
3243 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3244 command->child_func->parent_cmd = NULL;
3248 free(command->group_as_string);
3249 //command->group_as_string = NULL;
3251 for (r = command->redirects; r; r = rnext) {
3252 debug_printf_clean(" redirect %d%s",
3253 r->rd_fd, redir_table[r->rd_type].descrip);
3254 /* guard against the case >$FOO, where foo is unset or blank */
3255 if (r->rd_filename) {
3256 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3257 free(r->rd_filename);
3258 //r->rd_filename = NULL;
3260 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3264 //command->redirects = NULL;
3266 free(pi->cmds); /* children are an array, they get freed all at once */
3270 //pi->cmdtext = NULL;
3278 static void free_pipe_list(struct pipe *pi)
3282 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3284 debug_printf_clean("pipe followup code %d\n", pi->followup);
3290 /*** Parsing routines ***/
3292 #ifndef debug_print_tree
3293 static void debug_print_tree(struct pipe *pi, int lvl)
3295 static const char *const PIPE[] = {
3301 static const char *RES[] = {
3302 [RES_NONE ] = "NONE" ,
3305 [RES_THEN ] = "THEN" ,
3306 [RES_ELIF ] = "ELIF" ,
3307 [RES_ELSE ] = "ELSE" ,
3310 # if ENABLE_HUSH_LOOPS
3311 [RES_FOR ] = "FOR" ,
3312 [RES_WHILE] = "WHILE",
3313 [RES_UNTIL] = "UNTIL",
3315 [RES_DONE ] = "DONE" ,
3317 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3320 # if ENABLE_HUSH_CASE
3321 [RES_CASE ] = "CASE" ,
3322 [RES_CASE_IN ] = "CASE_IN" ,
3323 [RES_MATCH] = "MATCH",
3324 [RES_CASE_BODY] = "CASE_BODY",
3325 [RES_ESAC ] = "ESAC" ,
3327 [RES_XXXX ] = "XXXX" ,
3328 [RES_SNTX ] = "SNTX" ,
3330 static const char *const CMDTYPE[] = {
3334 # if ENABLE_HUSH_FUNCTIONS
3343 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3344 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3346 while (prn < pi->num_cmds) {
3347 struct command *command = &pi->cmds[prn];
3348 char **argv = command->argv;
3350 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3352 command->assignment_cnt);
3353 if (command->group) {
3354 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3355 CMDTYPE[command->cmd_type],
3358 , " group_as_string:", command->group_as_string
3363 debug_print_tree(command->group, lvl+1);
3367 if (argv) while (*argv) {
3368 fdprintf(2, " '%s'", *argv);
3378 #endif /* debug_print_tree */
3380 static struct pipe *new_pipe(void)
3383 pi = xzalloc(sizeof(struct pipe));
3384 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3388 /* Command (member of a pipe) is complete, or we start a new pipe
3389 * if ctx->command is NULL.
3390 * No errors possible here.
3392 static int done_command(struct parse_context *ctx)
3394 /* The command is really already in the pipe structure, so
3395 * advance the pipe counter and make a new, null command. */
3396 struct pipe *pi = ctx->pipe;
3397 struct command *command = ctx->command;
3399 #if 0 /* Instead we emit error message at run time */
3400 if (ctx->pending_redirect) {
3401 /* For example, "cmd >" (no filename to redirect to) */
3402 syntax_error("invalid redirect");
3403 ctx->pending_redirect = NULL;
3408 if (IS_NULL_CMD(command)) {
3409 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3413 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3414 //debug_print_tree(ctx->list_head, 20);
3416 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3419 /* Only real trickiness here is that the uncommitted
3420 * command structure is not counted in pi->num_cmds. */
3421 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3422 ctx->command = command = &pi->cmds[pi->num_cmds];
3424 memset(command, 0, sizeof(*command));
3425 return pi->num_cmds; /* used only for 0/nonzero check */
3428 static void done_pipe(struct parse_context *ctx, pipe_style type)
3432 debug_printf_parse("done_pipe entered, followup %d\n", type);
3433 /* Close previous command */
3434 not_null = done_command(ctx);
3436 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3437 ctx->ctx_inverted = 0;
3438 ctx->pipe->res_word = ctx->ctx_res_w;
3440 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3441 /* Necessary since && and || have precedence over &:
3442 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3443 * in a backgrounded subshell.
3446 struct command *command;
3448 /* Is this actually this construct, all pipes end with && or ||? */
3449 pi = ctx->list_head;
3450 while (pi != ctx->pipe) {
3451 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3456 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3457 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3458 pi = xzalloc(sizeof(*pi));
3459 pi->followup = PIPE_BG;
3461 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3462 command = &pi->cmds[0];
3463 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3464 command->cmd_type = CMD_NORMAL;
3465 command->group = ctx->list_head;
3467 command->group_as_string = xstrndup(
3468 ctx->as_string.data,
3469 ctx->as_string.length - 1 /* do not copy last char, "&" */
3472 /* Replace all pipes in ctx with one newly created */
3473 ctx->list_head = ctx->pipe = pi;
3476 ctx->pipe->followup = type;
3479 /* Without this check, even just <enter> on command line generates
3480 * tree of three NOPs (!). Which is harmless but annoying.
3481 * IOW: it is safe to do it unconditionally. */
3484 || ctx->ctx_res_w == RES_FI
3486 #if ENABLE_HUSH_LOOPS
3487 || ctx->ctx_res_w == RES_DONE
3488 || ctx->ctx_res_w == RES_FOR
3489 || ctx->ctx_res_w == RES_IN
3491 #if ENABLE_HUSH_CASE
3492 || ctx->ctx_res_w == RES_ESAC
3496 debug_printf_parse("done_pipe: adding new pipe: "
3497 "not_null:%d ctx->ctx_res_w:%d\n",
3498 not_null, ctx->ctx_res_w);
3500 ctx->pipe->next = new_p;
3502 /* RES_THEN, RES_DO etc are "sticky" -
3503 * they remain set for pipes inside if/while.
3504 * This is used to control execution.
3505 * RES_FOR and RES_IN are NOT sticky (needed to support
3506 * cases where variable or value happens to match a keyword):
3508 #if ENABLE_HUSH_LOOPS
3509 if (ctx->ctx_res_w == RES_FOR
3510 || ctx->ctx_res_w == RES_IN)
3511 ctx->ctx_res_w = RES_NONE;
3513 #if ENABLE_HUSH_CASE
3514 if (ctx->ctx_res_w == RES_MATCH)
3515 ctx->ctx_res_w = RES_CASE_BODY;
3516 if (ctx->ctx_res_w == RES_CASE)
3517 ctx->ctx_res_w = RES_CASE_IN;
3519 ctx->command = NULL; /* trick done_command below */
3520 /* Create the memory for command, roughly:
3521 * ctx->pipe->cmds = new struct command;
3522 * ctx->command = &ctx->pipe->cmds[0];
3525 //debug_print_tree(ctx->list_head, 10);
3527 debug_printf_parse("done_pipe return\n");
3530 static void initialize_context(struct parse_context *ctx)
3532 memset(ctx, 0, sizeof(*ctx));
3533 ctx->pipe = ctx->list_head = new_pipe();
3534 /* Create the memory for command, roughly:
3535 * ctx->pipe->cmds = new struct command;
3536 * ctx->command = &ctx->pipe->cmds[0];
3541 /* If a reserved word is found and processed, parse context is modified
3542 * and 1 is returned.
3545 struct reserved_combo {
3548 unsigned char assignment_flag;
3552 FLAG_END = (1 << RES_NONE ),
3554 FLAG_IF = (1 << RES_IF ),
3555 FLAG_THEN = (1 << RES_THEN ),
3556 FLAG_ELIF = (1 << RES_ELIF ),
3557 FLAG_ELSE = (1 << RES_ELSE ),
3558 FLAG_FI = (1 << RES_FI ),
3560 # if ENABLE_HUSH_LOOPS
3561 FLAG_FOR = (1 << RES_FOR ),
3562 FLAG_WHILE = (1 << RES_WHILE),
3563 FLAG_UNTIL = (1 << RES_UNTIL),
3564 FLAG_DO = (1 << RES_DO ),
3565 FLAG_DONE = (1 << RES_DONE ),
3566 FLAG_IN = (1 << RES_IN ),
3568 # if ENABLE_HUSH_CASE
3569 FLAG_MATCH = (1 << RES_MATCH),
3570 FLAG_ESAC = (1 << RES_ESAC ),
3572 FLAG_START = (1 << RES_XXXX ),
3575 static const struct reserved_combo* match_reserved_word(o_string *word)
3577 /* Mostly a list of accepted follow-up reserved words.
3578 * FLAG_END means we are done with the sequence, and are ready
3579 * to turn the compound list into a command.
3580 * FLAG_START means the word must start a new compound list.
3582 static const struct reserved_combo reserved_list[] = {
3584 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3585 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3586 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3587 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3588 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3589 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3591 # if ENABLE_HUSH_LOOPS
3592 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3593 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3594 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3595 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3596 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3597 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3599 # if ENABLE_HUSH_CASE
3600 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3601 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3604 const struct reserved_combo *r;
3606 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3607 if (strcmp(word->data, r->literal) == 0)
3612 /* Return 0: not a keyword, 1: keyword
3614 static int reserved_word(o_string *word, struct parse_context *ctx)
3616 # if ENABLE_HUSH_CASE
3617 static const struct reserved_combo reserved_match = {
3618 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3621 const struct reserved_combo *r;
3623 if (word->has_quoted_part)
3625 r = match_reserved_word(word);
3629 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3630 # if ENABLE_HUSH_CASE
3631 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3632 /* "case word IN ..." - IN part starts first MATCH part */
3633 r = &reserved_match;
3636 if (r->flag == 0) { /* '!' */
3637 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3638 syntax_error("! ! command");
3639 ctx->ctx_res_w = RES_SNTX;
3641 ctx->ctx_inverted = 1;
3644 if (r->flag & FLAG_START) {
3645 struct parse_context *old;
3647 old = xmemdup(ctx, sizeof(*ctx));
3648 debug_printf_parse("push stack %p\n", old);
3649 initialize_context(ctx);
3651 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3652 syntax_error_at(word->data);
3653 ctx->ctx_res_w = RES_SNTX;
3656 /* "{...} fi" is ok. "{...} if" is not
3658 * if { echo foo; } then { echo bar; } fi */
3659 if (ctx->command->group)
3660 done_pipe(ctx, PIPE_SEQ);
3663 ctx->ctx_res_w = r->res;
3664 ctx->old_flag = r->flag;
3665 word->o_assignment = r->assignment_flag;
3666 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3668 if (ctx->old_flag & FLAG_END) {
3669 struct parse_context *old;
3671 done_pipe(ctx, PIPE_SEQ);
3672 debug_printf_parse("pop stack %p\n", ctx->stack);
3674 old->command->group = ctx->list_head;
3675 old->command->cmd_type = CMD_NORMAL;
3677 /* At this point, the compound command's string is in
3678 * ctx->as_string... except for the leading keyword!
3679 * Consider this example: "echo a | if true; then echo a; fi"
3680 * ctx->as_string will contain "true; then echo a; fi",
3681 * with "if " remaining in old->as_string!
3685 int len = old->as_string.length;
3686 /* Concatenate halves */
3687 o_addstr(&old->as_string, ctx->as_string.data);
3688 o_free_unsafe(&ctx->as_string);
3689 /* Find where leading keyword starts in first half */
3690 str = old->as_string.data + len;
3691 if (str > old->as_string.data)
3692 str--; /* skip whitespace after keyword */
3693 while (str > old->as_string.data && isalpha(str[-1]))
3695 /* Ugh, we're done with this horrid hack */
3696 old->command->group_as_string = xstrdup(str);
3697 debug_printf_parse("pop, remembering as:'%s'\n",
3698 old->command->group_as_string);
3701 *ctx = *old; /* physical copy */
3706 #endif /* HAS_KEYWORDS */
3708 /* Word is complete, look at it and update parsing context.
3709 * Normal return is 0. Syntax errors return 1.
3710 * Note: on return, word is reset, but not o_free'd!
3712 static int done_word(o_string *word, struct parse_context *ctx)
3714 struct command *command = ctx->command;
3716 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3717 if (word->length == 0 && !word->has_quoted_part) {
3718 debug_printf_parse("done_word return 0: true null, ignored\n");
3722 if (ctx->pending_redirect) {
3723 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3724 * only if run as "bash", not "sh" */
3725 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3727 * ...the word that follows the redirection operator
3728 * shall be subjected to tilde expansion, parameter expansion,
3729 * command substitution, arithmetic expansion, and quote
3730 * removal. Pathname expansion shall not be performed
3731 * on the word by a non-interactive shell; an interactive
3732 * shell may perform it, but shall do so only when
3733 * the expansion would result in one word."
3735 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3736 /* Cater for >\file case:
3737 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3738 * Same with heredocs:
3739 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3741 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3742 unbackslash(ctx->pending_redirect->rd_filename);
3743 /* Is it <<"HEREDOC"? */
3744 if (word->has_quoted_part) {
3745 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3748 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3749 ctx->pending_redirect = NULL;
3752 # if ENABLE_HUSH_CASE
3753 if (ctx->ctx_dsemicolon
3754 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3756 /* already done when ctx_dsemicolon was set to 1: */
3757 /* ctx->ctx_res_w = RES_MATCH; */
3758 ctx->ctx_dsemicolon = 0;
3761 if (!command->argv /* if it's the first word... */
3762 # if ENABLE_HUSH_LOOPS
3763 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3764 && ctx->ctx_res_w != RES_IN
3766 # if ENABLE_HUSH_CASE
3767 && ctx->ctx_res_w != RES_CASE
3770 int reserved = reserved_word(word, ctx);
3771 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3773 o_reset_to_empty_unquoted(word);
3774 debug_printf_parse("done_word return %d\n",
3775 (ctx->ctx_res_w == RES_SNTX));
3776 return (ctx->ctx_res_w == RES_SNTX);
3779 if (strcmp(word->data, "[[") == 0) {
3780 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3786 if (command->group) {
3787 /* "{ echo foo; } echo bar" - bad */
3788 syntax_error_at(word->data);
3789 debug_printf_parse("done_word return 1: syntax error, "
3790 "groups and arglists don't mix\n");
3794 /* If this word wasn't an assignment, next ones definitely
3795 * can't be assignments. Even if they look like ones. */
3796 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3797 && word->o_assignment != WORD_IS_KEYWORD
3799 word->o_assignment = NOT_ASSIGNMENT;
3801 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3802 command->assignment_cnt++;
3803 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3805 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3806 word->o_assignment = MAYBE_ASSIGNMENT;
3808 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3810 if (word->has_quoted_part
3811 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3812 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3813 /* (otherwise it's known to be not empty and is already safe) */
3815 /* exclude "$@" - it can expand to no word despite "" */
3816 char *p = word->data;
3817 while (p[0] == SPECIAL_VAR_SYMBOL
3818 && (p[1] & 0x7f) == '@'
3819 && p[2] == SPECIAL_VAR_SYMBOL
3824 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3825 debug_print_strings("word appended to argv", command->argv);
3828 #if ENABLE_HUSH_LOOPS
3829 if (ctx->ctx_res_w == RES_FOR) {
3830 if (word->has_quoted_part
3831 || !is_well_formed_var_name(command->argv[0], '\0')
3833 /* bash says just "not a valid identifier" */
3834 syntax_error("not a valid identifier in for");
3837 /* Force FOR to have just one word (variable name) */
3838 /* NB: basically, this makes hush see "for v in ..."
3839 * syntax as if it is "for v; in ...". FOR and IN become
3840 * two pipe structs in parse tree. */
3841 done_pipe(ctx, PIPE_SEQ);
3844 #if ENABLE_HUSH_CASE
3845 /* Force CASE to have just one word */
3846 if (ctx->ctx_res_w == RES_CASE) {
3847 done_pipe(ctx, PIPE_SEQ);
3851 o_reset_to_empty_unquoted(word);
3853 debug_printf_parse("done_word return 0\n");
3858 /* Peek ahead in the input to find out if we have a "&n" construct,
3859 * as in "2>&1", that represents duplicating a file descriptor.
3861 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3862 * REDIRFD_SYNTAX_ERR if syntax error,
3863 * REDIRFD_TO_FILE if no & was seen,
3864 * or the number found.
3867 #define parse_redir_right_fd(as_string, input) \
3868 parse_redir_right_fd(input)
3870 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3876 return REDIRFD_TO_FILE;
3878 ch = i_getch(input); /* get the & */
3879 nommu_addchr(as_string, ch);
3882 ch = i_getch(input);
3883 nommu_addchr(as_string, ch);
3884 return REDIRFD_CLOSE;
3888 while (ch != EOF && isdigit(ch)) {
3889 d = d*10 + (ch-'0');
3891 ch = i_getch(input);
3892 nommu_addchr(as_string, ch);
3897 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3899 bb_error_msg("ambiguous redirect");
3900 return REDIRFD_SYNTAX_ERR;
3903 /* Return code is 0 normal, 1 if a syntax error is detected
3905 static int parse_redirect(struct parse_context *ctx,
3908 struct in_str *input)
3910 struct command *command = ctx->command;
3911 struct redir_struct *redir;
3912 struct redir_struct **redirp;
3915 dup_num = REDIRFD_TO_FILE;
3916 if (style != REDIRECT_HEREDOC) {
3917 /* Check for a '>&1' type redirect */
3918 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3919 if (dup_num == REDIRFD_SYNTAX_ERR)
3922 int ch = i_peek(input);
3923 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3924 if (dup_num) { /* <<-... */
3925 ch = i_getch(input);
3926 nommu_addchr(&ctx->as_string, ch);
3931 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3932 int ch = i_peek(input);
3934 /* >|FILE redirect ("clobbering" >).
3935 * Since we do not support "set -o noclobber" yet,
3936 * >| and > are the same for now. Just eat |.
3938 ch = i_getch(input);
3939 nommu_addchr(&ctx->as_string, ch);
3943 /* Create a new redir_struct and append it to the linked list */
3944 redirp = &command->redirects;
3945 while ((redir = *redirp) != NULL) {
3946 redirp = &(redir->next);
3948 *redirp = redir = xzalloc(sizeof(*redir));
3949 /* redir->next = NULL; */
3950 /* redir->rd_filename = NULL; */
3951 redir->rd_type = style;
3952 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3954 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3955 redir_table[style].descrip);
3957 redir->rd_dup = dup_num;
3958 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3959 /* Erik had a check here that the file descriptor in question
3960 * is legit; I postpone that to "run time"
3961 * A "-" representation of "close me" shows up as a -3 here */
3962 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3963 redir->rd_fd, redir->rd_dup);
3965 #if 0 /* Instead we emit error message at run time */
3966 if (ctx->pending_redirect) {
3967 /* For example, "cmd > <file" */
3968 syntax_error("invalid redirect");
3971 /* Set ctx->pending_redirect, so we know what to do at the
3972 * end of the next parsed word. */
3973 ctx->pending_redirect = redir;
3978 /* If a redirect is immediately preceded by a number, that number is
3979 * supposed to tell which file descriptor to redirect. This routine
3980 * looks for such preceding numbers. In an ideal world this routine
3981 * needs to handle all the following classes of redirects...
3982 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3983 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3984 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3985 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3987 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3989 * ... If n is quoted, the number shall not be recognized as part of
3990 * the redirection expression. For example:
3992 * writes the character 2 into file a"
3993 * We are getting it right by setting ->has_quoted_part on any \<char>
3995 * A -1 return means no valid number was found,
3996 * the caller should use the appropriate default for this redirection.
3998 static int redirect_opt_num(o_string *o)
4002 if (o->data == NULL)
4004 num = bb_strtou(o->data, NULL, 10);
4005 if (errno || num < 0)
4007 o_reset_to_empty_unquoted(o);
4012 #define fetch_till_str(as_string, input, word, skip_tabs) \
4013 fetch_till_str(input, word, skip_tabs)
4015 static char *fetch_till_str(o_string *as_string,
4016 struct in_str *input,
4020 o_string heredoc = NULL_O_STRING;
4022 int prev = 0; /* not \ */
4028 ch = i_getch(input);
4030 nommu_addchr(as_string, ch);
4031 if (ch == '\n' || ch == EOF) {
4033 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4034 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4035 heredoc.data[past_EOL] = '\0';
4036 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4037 return heredoc.data;
4040 /* This is a new line.
4041 * Remember position and backslash-escaping status.
4043 o_addchr(&heredoc, ch);
4046 past_EOL = heredoc.length;
4047 /* Get 1st char of next line, possibly skipping leading tabs */
4049 ch = i_getch(input);
4051 nommu_addchr(as_string, ch);
4052 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4053 /* If this immediately ended the line,
4054 * go back to end-of-line checks.
4057 goto check_heredoc_end;
4062 o_free_unsafe(&heredoc);
4065 o_addchr(&heredoc, ch);
4066 nommu_addchr(as_string, ch);
4067 if (prev == '\\' && ch == '\\')
4068 /* Correctly handle foo\\<eol> (not a line cont.) */
4069 prev = 0; /* not \ */
4075 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4076 * and load them all. There should be exactly heredoc_cnt of them.
4078 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4080 struct pipe *pi = ctx->list_head;
4082 while (pi && heredoc_cnt) {
4084 struct command *cmd = pi->cmds;
4086 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4088 cmd->argv ? cmd->argv[0] : "NONE");
4089 for (i = 0; i < pi->num_cmds; i++) {
4090 struct redir_struct *redir = cmd->redirects;
4092 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4093 i, cmd->argv ? cmd->argv[0] : "NONE");
4095 if (redir->rd_type == REDIRECT_HEREDOC) {
4098 redir->rd_type = REDIRECT_HEREDOC2;
4099 /* redir->rd_dup is (ab)used to indicate <<- */
4100 p = fetch_till_str(&ctx->as_string, input,
4101 redir->rd_filename, redir->rd_dup);
4103 syntax_error("unexpected EOF in here document");
4106 free(redir->rd_filename);
4107 redir->rd_filename = p;
4110 redir = redir->next;
4117 /* Should be 0. If it isn't, it's a parse error */
4119 bb_error_msg_and_die("heredoc BUG 2");
4125 static int run_list(struct pipe *pi);
4127 #define parse_stream(pstring, input, end_trigger) \
4128 parse_stream(input, end_trigger)
4130 static struct pipe *parse_stream(char **pstring,
4131 struct in_str *input,
4135 #if !ENABLE_HUSH_FUNCTIONS
4136 #define parse_group(dest, ctx, input, ch) \
4137 parse_group(ctx, input, ch)
4139 static int parse_group(o_string *dest, struct parse_context *ctx,
4140 struct in_str *input, int ch)
4142 /* dest contains characters seen prior to ( or {.
4143 * Typically it's empty, but for function defs,
4144 * it contains function name (without '()'). */
4145 struct pipe *pipe_list;
4147 struct command *command = ctx->command;
4149 debug_printf_parse("parse_group entered\n");
4150 #if ENABLE_HUSH_FUNCTIONS
4151 if (ch == '(' && !dest->has_quoted_part) {
4153 if (done_word(dest, ctx))
4156 goto skip; /* (... */
4157 if (command->argv[1]) { /* word word ... (... */
4158 syntax_error_unexpected_ch('(');
4161 /* it is "word(..." or "word (..." */
4163 ch = i_getch(input);
4164 while (ch == ' ' || ch == '\t');
4166 syntax_error_unexpected_ch(ch);
4169 nommu_addchr(&ctx->as_string, ch);
4171 ch = i_getch(input);
4172 while (ch == ' ' || ch == '\t' || ch == '\n');
4174 syntax_error_unexpected_ch(ch);
4177 nommu_addchr(&ctx->as_string, ch);
4178 command->cmd_type = CMD_FUNCDEF;
4183 #if 0 /* Prevented by caller */
4184 if (command->argv /* word [word]{... */
4185 || dest->length /* word{... */
4186 || dest->has_quoted_part /* ""{... */
4189 debug_printf_parse("parse_group return 1: "
4190 "syntax error, groups and arglists don't mix\n");
4195 #if ENABLE_HUSH_FUNCTIONS
4201 command->cmd_type = CMD_SUBSHELL;
4203 /* bash does not allow "{echo...", requires whitespace */
4205 if (ch != ' ' && ch != '\t' && ch != '\n'
4206 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4208 syntax_error_unexpected_ch(ch);
4212 ch = i_getch(input);
4213 nommu_addchr(&ctx->as_string, ch);
4219 # define as_string NULL
4221 char *as_string = NULL;
4223 pipe_list = parse_stream(&as_string, input, endch);
4226 o_addstr(&ctx->as_string, as_string);
4228 /* empty ()/{} or parse error? */
4229 if (!pipe_list || pipe_list == ERR_PTR) {
4230 /* parse_stream already emitted error msg */
4233 debug_printf_parse("parse_group return 1: "
4234 "parse_stream returned %p\n", pipe_list);
4237 command->group = pipe_list;
4239 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4240 command->group_as_string = as_string;
4241 debug_printf_parse("end of group, remembering as:'%s'\n",
4242 command->group_as_string);
4246 debug_printf_parse("parse_group return 0\n");
4248 /* command remains "open", available for possible redirects */
4251 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4256 ch = i_getch(input);
4259 ch2 = i_peek(input);
4262 /* backslash+newline, skip it */
4267 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4275 ch2 = i_peek2(input);
4278 /* backslash+newline, skip it */
4284 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4285 /* Subroutines for copying $(...) and `...` things */
4286 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4288 static int add_till_single_quote(o_string *dest, struct in_str *input)
4291 int ch = i_getch(input);
4293 syntax_error_unterm_ch('\'');
4301 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4302 static int add_till_double_quote(o_string *dest, struct in_str *input)
4305 int ch = i_getch(input);
4307 syntax_error_unterm_ch('"');
4312 if (ch == '\\') { /* \x. Copy both chars. */
4314 ch = i_getch(input);
4318 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4323 //if (ch == '$') ...
4326 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4328 * "Within the backquoted style of command substitution, backslash
4329 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4330 * The search for the matching backquote shall be satisfied by the first
4331 * backquote found without a preceding backslash; during this search,
4332 * if a non-escaped backquote is encountered within a shell comment,
4333 * a here-document, an embedded command substitution of the $(command)
4334 * form, or a quoted string, undefined results occur. A single-quoted
4335 * or double-quoted string that begins, but does not end, within the
4336 * "`...`" sequence produces undefined results."
4338 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4340 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4343 int ch = i_getch(input);
4347 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4348 ch = i_getch(input);
4352 && (!in_dquote || ch != '"')
4354 o_addchr(dest, '\\');
4358 syntax_error_unterm_ch('`');
4364 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4365 * quoting and nested ()s.
4366 * "With the $(command) style of command substitution, all characters
4367 * following the open parenthesis to the matching closing parenthesis
4368 * constitute the command. Any valid shell script can be used for command,
4369 * except a script consisting solely of redirections which produces
4370 * unspecified results."
4372 * echo $(echo '(TEST)' BEST) (TEST) BEST
4373 * echo $(echo 'TEST)' BEST) TEST) BEST
4374 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4376 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4377 * can contain arbitrary constructs, just like $(cmd).
4378 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4379 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4381 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4382 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4385 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4386 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4387 char end_char2 = end_ch >> 8;
4389 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4392 ch = i_getch(input);
4394 syntax_error_unterm_ch(end_ch);
4398 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4404 /* we look for closing )) of $((EXPR)) */
4405 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4406 i_getch(input); /* eat second ')' */
4411 if (ch == '(' || ch == '{') {
4412 ch = (ch == '(' ? ')' : '}');
4413 if (!add_till_closing_bracket(dest, input, ch))
4419 if (!add_till_single_quote(dest, input))
4425 if (!add_till_double_quote(dest, input))
4431 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4437 /* \x. Copy verbatim. Important for \(, \) */
4438 ch = i_getch(input);
4440 syntax_error_unterm_ch(')');
4445 /* "backslash+newline", ignore both */
4446 o_delchr(dest); /* undo insertion of '\' */
4456 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4458 /* Return code: 0 for OK, 1 for syntax error */
4460 #define parse_dollar(as_string, dest, input, quote_mask) \
4461 parse_dollar(dest, input, quote_mask)
4462 #define as_string NULL
4464 static int parse_dollar(o_string *as_string,
4466 struct in_str *input, unsigned char quote_mask)
4468 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4470 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4472 ch = i_getch(input);
4473 nommu_addchr(as_string, ch);
4475 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4477 debug_printf_parse(": '%c'\n", ch);
4478 o_addchr(dest, ch | quote_mask);
4480 ch = i_peek_and_eat_bkslash_nl(input);
4481 if (!isalnum(ch) && ch != '_') {
4482 /* End of variable name reached */
4485 ch = i_getch(input);
4486 nommu_addchr(as_string, ch);
4488 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4489 } else if (isdigit(ch)) {
4491 ch = i_getch(input);
4492 nommu_addchr(as_string, ch);
4493 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4494 debug_printf_parse(": '%c'\n", ch);
4495 o_addchr(dest, ch | quote_mask);
4496 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4497 } else switch (ch) {
4499 case '!': /* last bg pid */
4500 case '?': /* last exit code */
4501 case '#': /* number of args */
4502 case '*': /* args */
4503 case '@': /* args */
4504 goto make_one_char_var;
4508 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4510 ch = i_getch(input); /* eat '{' */
4511 nommu_addchr(as_string, ch);
4513 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4514 /* It should be ${?}, or ${#var},
4515 * or even ${?+subst} - operator acting on a special variable,
4516 * or the beginning of variable name.
4519 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4522 syntax_error_unterm_str("${name}");
4523 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4526 nommu_addchr(as_string, ch);
4530 /* It's possible to just call add_till_closing_bracket() at this point.
4531 * However, this regresses some of our testsuite cases
4532 * which check invalid constructs like ${%}.
4533 * Oh well... let's check that the var name part is fine... */
4539 debug_printf_parse(": '%c'\n", ch);
4541 ch = i_getch(input);
4542 nommu_addchr(as_string, ch);
4546 if (!isalnum(ch) && ch != '_') {
4548 unsigned char last_ch;
4549 /* handle parameter expansions
4550 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4552 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4553 if (len_single_ch != '#'
4554 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4555 || i_peek(input) != '}'
4557 goto bad_dollar_syntax;
4559 /* else: it's "length of C" ${#C} op,
4560 * where C is a single char
4561 * special var name, e.g. ${#!}.
4564 /* Eat everything until closing '}' (or ':') */
4568 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4570 /* It's ${var:N[:M]} thing */
4571 end_ch = '}' * 0x100 + ':';
4573 if (BASH_PATTERN_SUBST
4576 /* It's ${var/[/]pattern[/repl]} thing */
4577 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4579 nommu_addchr(as_string, '/');
4582 end_ch = '}' * 0x100 + '/';
4588 #if ENABLE_HUSH_DOLLAR_OPS
4589 last_ch = add_till_closing_bracket(dest, input, end_ch);
4590 if (last_ch == 0) /* error? */
4593 #error Simple code to only allow ${var} is not implemented
4596 o_addstr(as_string, dest->data + pos);
4597 o_addchr(as_string, last_ch);
4600 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4601 && (end_ch & 0xff00)
4603 /* close the first block: */
4604 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4605 /* while parsing N from ${var:N[:M]}
4606 * or pattern from ${var/[/]pattern[/repl]} */
4607 if ((end_ch & 0xff) == last_ch) {
4608 /* got ':' or '/'- parse the rest */
4613 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4614 /* it's ${var:N} - emulate :999999999 */
4615 o_addstr(dest, "999999999");
4616 } /* else: it's ${var/[/]pattern} */
4620 len_single_ch = 0; /* it can't be ${#C} op */
4622 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4625 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4629 ch = i_getch(input);
4630 nommu_addchr(as_string, ch);
4631 # if ENABLE_FEATURE_SH_MATH
4632 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4633 ch = i_getch(input);
4634 nommu_addchr(as_string, ch);
4635 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4636 o_addchr(dest, /*quote_mask |*/ '+');
4639 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4640 return 0; /* error */
4642 o_addstr(as_string, dest->data + pos);
4643 o_addchr(as_string, ')');
4644 o_addchr(as_string, ')');
4646 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4650 # if ENABLE_HUSH_TICK
4651 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4652 o_addchr(dest, quote_mask | '`');
4655 if (!add_till_closing_bracket(dest, input, ')'))
4656 return 0; /* error */
4658 o_addstr(as_string, dest->data + pos);
4659 o_addchr(as_string, ')');
4661 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4667 ch = i_getch(input);
4668 nommu_addchr(as_string, ch);
4669 ch = i_peek_and_eat_bkslash_nl(input);
4670 if (isalnum(ch)) { /* it's $_name or $_123 */
4675 /* TODO: $_ and $-: */
4676 /* $_ Shell or shell script name; or last argument of last command
4677 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4678 * but in command's env, set to full pathname used to invoke it */
4679 /* $- Option flags set by set builtin or shell options (-i etc) */
4681 o_addQchr(dest, '$');
4683 debug_printf_parse("parse_dollar return 1 (ok)\n");
4689 # if BASH_PATTERN_SUBST
4690 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4691 encode_string(dest, input, dquote_end, process_bkslash)
4693 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4694 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4695 encode_string(dest, input, dquote_end)
4697 #define as_string NULL
4701 # if BASH_PATTERN_SUBST
4702 /* all parameters are needed, no macro tricks */
4704 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4705 encode_string(as_string, dest, input, dquote_end)
4708 static int encode_string(o_string *as_string,
4710 struct in_str *input,
4712 int process_bkslash)
4714 #if !BASH_PATTERN_SUBST
4715 const int process_bkslash = 1;
4721 ch = i_getch(input);
4723 nommu_addchr(as_string, ch);
4724 if (ch == dquote_end) { /* may be only '"' or EOF */
4725 debug_printf_parse("encode_string return 1 (ok)\n");
4728 /* note: can't move it above ch == dquote_end check! */
4730 syntax_error_unterm_ch('"');
4731 return 0; /* error */
4735 next = i_peek(input);
4737 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4738 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4739 if (process_bkslash && ch == '\\') {
4741 syntax_error("\\<eof>");
4745 * "The backslash retains its special meaning [in "..."]
4746 * only when followed by one of the following characters:
4747 * $, `, ", \, or <newline>. A double quote may be quoted
4748 * within double quotes by preceding it with a backslash."
4749 * NB: in (unquoted) heredoc, above does not apply to ",
4750 * therefore we check for it by "next == dquote_end" cond.
4752 if (next == dquote_end || strchr("$`\\\n", next)) {
4753 ch = i_getch(input); /* eat next */
4755 goto again; /* skip \<newline> */
4756 } /* else: ch remains == '\\', and we double it below: */
4757 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4758 nommu_addchr(as_string, ch);
4762 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4763 debug_printf_parse("encode_string return 0: "
4764 "parse_dollar returned 0 (error)\n");
4769 #if ENABLE_HUSH_TICK
4771 //unsigned pos = dest->length;
4772 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4773 o_addchr(dest, 0x80 | '`');
4774 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4775 return 0; /* error */
4776 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4777 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4781 o_addQchr(dest, ch);
4787 * Scan input until EOF or end_trigger char.
4788 * Return a list of pipes to execute, or NULL on EOF
4789 * or if end_trigger character is met.
4790 * On syntax error, exit if shell is not interactive,
4791 * reset parsing machinery and start parsing anew,
4792 * or return ERR_PTR.
4794 static struct pipe *parse_stream(char **pstring,
4795 struct in_str *input,
4798 struct parse_context ctx;
4799 o_string dest = NULL_O_STRING;
4802 /* Single-quote triggers a bypass of the main loop until its mate is
4803 * found. When recursing, quote state is passed in via dest->o_expflags.
4805 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4806 end_trigger ? end_trigger : 'X');
4809 /* If very first arg is "" or '', dest.data may end up NULL.
4810 * Preventing this: */
4811 o_addchr(&dest, '\0');
4814 /* We used to separate words on $IFS here. This was wrong.
4815 * $IFS is used only for word splitting when $var is expanded,
4816 * here we should use blank chars as separators, not $IFS
4819 if (MAYBE_ASSIGNMENT != 0)
4820 dest.o_assignment = MAYBE_ASSIGNMENT;
4821 initialize_context(&ctx);
4824 const char *is_blank;
4825 const char *is_special;
4829 redir_type redir_style;
4831 ch = i_getch(input);
4832 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4833 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4838 syntax_error_unterm_str("here document");
4841 if (end_trigger == ')') {
4842 syntax_error_unterm_ch('(');
4845 if (end_trigger == '}') {
4846 syntax_error_unterm_ch('{');
4850 if (done_word(&dest, &ctx)) {
4854 done_pipe(&ctx, PIPE_SEQ);
4856 /* If we got nothing... */
4857 /* (this makes bare "&" cmd a no-op.
4858 * bash says: "syntax error near unexpected token '&'") */
4859 if (pi->num_cmds == 0
4860 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4866 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4868 *pstring = ctx.as_string.data;
4870 o_free_unsafe(&ctx.as_string);
4873 debug_printf_parse("parse_stream return %p\n", pi);
4876 nommu_addchr(&ctx.as_string, ch);
4880 next = i_peek(input);
4882 is_special = "{}<>;&|()#'" /* special outside of "str" */
4883 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4884 /* Are { and } special here? */
4885 if (ctx.command->argv /* word [word]{... - non-special */
4886 || dest.length /* word{... - non-special */
4887 || dest.has_quoted_part /* ""{... - non-special */
4888 || (next != ';' /* }; - special */
4889 && next != ')' /* }) - special */
4890 && next != '(' /* {( - special */
4891 && next != '&' /* }& and }&& ... - special */
4892 && next != '|' /* }|| ... - special */
4893 && !strchr(defifs, next) /* {word - non-special */
4896 /* They are not special, skip "{}" */
4899 is_special = strchr(is_special, ch);
4900 is_blank = strchr(defifs, ch);
4902 if (!is_special && !is_blank) { /* ordinary char */
4904 o_addQchr(&dest, ch);
4905 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4906 || dest.o_assignment == WORD_IS_KEYWORD)
4908 && is_well_formed_var_name(dest.data, '=')
4910 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4911 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4917 if (done_word(&dest, &ctx)) {
4921 /* Is this a case when newline is simply ignored?
4923 * "cmd | <newline> cmd ..."
4924 * "case ... in <newline> word) ..."
4926 if (IS_NULL_CMD(ctx.command)
4927 && dest.length == 0 && !dest.has_quoted_part
4929 /* This newline can be ignored. But...
4930 * Without check #1, interactive shell
4931 * ignores even bare <newline>,
4932 * and shows the continuation prompt:
4933 * ps1_prompt$ <enter>
4934 * ps2> _ <=== wrong, should be ps1
4935 * Without check #2, "cmd & <newline>"
4936 * is similarly mistreated.
4937 * (BTW, this makes "cmd & cmd"
4938 * and "cmd && cmd" non-orthogonal.
4939 * Really, ask yourself, why
4940 * "cmd && <newline>" doesn't start
4941 * cmd but waits for more input?
4942 * The only reason is that it might be
4943 * a "cmd1 && <nl> cmd2 &" construct,
4944 * cmd1 may need to run in BG).
4946 struct pipe *pi = ctx.list_head;
4947 if (pi->num_cmds != 0 /* check #1 */
4948 && pi->followup != PIPE_BG /* check #2 */
4953 /* Treat newline as a command separator. */
4954 done_pipe(&ctx, PIPE_SEQ);
4955 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4957 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4962 dest.o_assignment = MAYBE_ASSIGNMENT;
4963 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4965 /* note: if (is_blank) continue;
4966 * will still trigger for us */
4970 /* "cmd}" or "cmd }..." without semicolon or &:
4971 * } is an ordinary char in this case, even inside { cmd; }
4972 * Pathological example: { ""}; } should exec "}" cmd
4975 if (dest.length != 0 /* word} */
4976 || dest.has_quoted_part /* ""} */
4980 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4981 /* Generally, there should be semicolon: "cmd; }"
4982 * However, bash allows to omit it if "cmd" is
4983 * a group. Examples:
4986 * { echo 0 >&2 | { echo 1; } }
4987 * { while false; do :; done }
4988 * { case a in b) ;; esac }
4990 if (ctx.command->group)
4994 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4995 /* Can't be an end of {cmd}, skip the check */
4996 goto skip_end_trigger;
4997 /* else: } does terminate a group */
5000 if (end_trigger && end_trigger == ch
5001 && (ch != ';' || heredoc_cnt == 0)
5002 #if ENABLE_HUSH_CASE
5004 || ctx.ctx_res_w != RES_MATCH
5005 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5010 /* This is technically valid:
5011 * { cat <<HERE; }; echo Ok
5015 * but we don't support this.
5016 * We require heredoc to be in enclosing {}/(),
5019 syntax_error_unterm_str("here document");
5022 if (done_word(&dest, &ctx)) {
5025 done_pipe(&ctx, PIPE_SEQ);
5026 dest.o_assignment = MAYBE_ASSIGNMENT;
5027 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5028 /* Do we sit outside of any if's, loops or case's? */
5030 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5034 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5036 *pstring = ctx.as_string.data;
5038 o_free_unsafe(&ctx.as_string);
5040 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5041 /* Example: bare "{ }", "()" */
5042 G.last_exitcode = 2; /* bash compat */
5043 syntax_error_unexpected_ch(ch);
5046 debug_printf_parse("parse_stream return %p: "
5047 "end_trigger char found\n",
5050 return ctx.list_head;
5057 /* Catch <, > before deciding whether this word is
5058 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5061 redir_fd = redirect_opt_num(&dest);
5062 if (done_word(&dest, &ctx)) {
5065 redir_style = REDIRECT_OVERWRITE;
5067 redir_style = REDIRECT_APPEND;
5068 ch = i_getch(input);
5069 nommu_addchr(&ctx.as_string, ch);
5072 else if (next == '(') {
5073 syntax_error(">(process) not supported");
5077 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5079 continue; /* back to top of while (1) */
5081 redir_fd = redirect_opt_num(&dest);
5082 if (done_word(&dest, &ctx)) {
5085 redir_style = REDIRECT_INPUT;
5087 redir_style = REDIRECT_HEREDOC;
5089 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5090 ch = i_getch(input);
5091 nommu_addchr(&ctx.as_string, ch);
5092 } else if (next == '>') {
5093 redir_style = REDIRECT_IO;
5094 ch = i_getch(input);
5095 nommu_addchr(&ctx.as_string, ch);
5098 else if (next == '(') {
5099 syntax_error("<(process) not supported");
5103 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5105 continue; /* back to top of while (1) */
5107 if (dest.length == 0 && !dest.has_quoted_part) {
5108 /* skip "#comment" */
5111 if (ch == EOF || ch == '\n')
5114 /* note: we do not add it to &ctx.as_string */
5116 nommu_addchr(&ctx.as_string, '\n');
5117 continue; /* back to top of while (1) */
5122 /* It's "\<newline>" */
5124 /* Remove trailing '\' from ctx.as_string */
5125 ctx.as_string.data[--ctx.as_string.length] = '\0';
5127 ch = i_getch(input); /* eat it */
5128 continue; /* back to top of while (1) */
5133 if (dest.o_assignment == MAYBE_ASSIGNMENT
5134 /* check that we are not in word in "a=1 2>word b=1": */
5135 && !ctx.pending_redirect
5137 /* ch is a special char and thus this word
5138 * cannot be an assignment */
5139 dest.o_assignment = NOT_ASSIGNMENT;
5140 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5143 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5146 case '#': /* non-comment #: "echo a#b" etc */
5147 o_addQchr(&dest, ch);
5151 syntax_error("\\<eof>");
5154 ch = i_getch(input);
5155 /* note: ch != '\n' (that case does not reach this place) */
5156 o_addchr(&dest, '\\');
5157 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5158 o_addchr(&dest, ch);
5159 nommu_addchr(&ctx.as_string, ch);
5160 /* Example: echo Hello \2>file
5161 * we need to know that word 2 is quoted */
5162 dest.has_quoted_part = 1;
5165 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5166 debug_printf_parse("parse_stream parse error: "
5167 "parse_dollar returned 0 (error)\n");
5172 dest.has_quoted_part = 1;
5173 if (next == '\'' && !ctx.pending_redirect) {
5174 insert_empty_quoted_str_marker:
5175 nommu_addchr(&ctx.as_string, next);
5176 i_getch(input); /* eat second ' */
5177 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5178 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5181 ch = i_getch(input);
5183 syntax_error_unterm_ch('\'');
5186 nommu_addchr(&ctx.as_string, ch);
5189 o_addqchr(&dest, ch);
5194 dest.has_quoted_part = 1;
5195 if (next == '"' && !ctx.pending_redirect)
5196 goto insert_empty_quoted_str_marker;
5197 if (dest.o_assignment == NOT_ASSIGNMENT)
5198 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5199 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5201 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5203 #if ENABLE_HUSH_TICK
5205 USE_FOR_NOMMU(unsigned pos;)
5207 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5208 o_addchr(&dest, '`');
5209 USE_FOR_NOMMU(pos = dest.length;)
5210 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5213 o_addstr(&ctx.as_string, dest.data + pos);
5214 o_addchr(&ctx.as_string, '`');
5216 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5217 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5222 #if ENABLE_HUSH_CASE
5225 if (done_word(&dest, &ctx)) {
5228 done_pipe(&ctx, PIPE_SEQ);
5229 #if ENABLE_HUSH_CASE
5230 /* Eat multiple semicolons, detect
5231 * whether it means something special */
5236 ch = i_getch(input);
5237 nommu_addchr(&ctx.as_string, ch);
5238 if (ctx.ctx_res_w == RES_CASE_BODY) {
5239 ctx.ctx_dsemicolon = 1;
5240 ctx.ctx_res_w = RES_MATCH;
5246 /* We just finished a cmd. New one may start
5247 * with an assignment */
5248 dest.o_assignment = MAYBE_ASSIGNMENT;
5249 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5252 if (done_word(&dest, &ctx)) {
5256 ch = i_getch(input);
5257 nommu_addchr(&ctx.as_string, ch);
5258 done_pipe(&ctx, PIPE_AND);
5260 done_pipe(&ctx, PIPE_BG);
5264 if (done_word(&dest, &ctx)) {
5267 #if ENABLE_HUSH_CASE
5268 if (ctx.ctx_res_w == RES_MATCH)
5269 break; /* we are in case's "word | word)" */
5271 if (next == '|') { /* || */
5272 ch = i_getch(input);
5273 nommu_addchr(&ctx.as_string, ch);
5274 done_pipe(&ctx, PIPE_OR);
5276 /* we could pick up a file descriptor choice here
5277 * with redirect_opt_num(), but bash doesn't do it.
5278 * "echo foo 2| cat" yields "foo 2". */
5283 #if ENABLE_HUSH_CASE
5284 /* "case... in [(]word)..." - skip '(' */
5285 if (ctx.ctx_res_w == RES_MATCH
5286 && ctx.command->argv == NULL /* not (word|(... */
5287 && dest.length == 0 /* not word(... */
5288 && dest.has_quoted_part == 0 /* not ""(... */
5294 if (parse_group(&dest, &ctx, input, ch) != 0) {
5299 #if ENABLE_HUSH_CASE
5300 if (ctx.ctx_res_w == RES_MATCH)
5304 /* proper use of this character is caught by end_trigger:
5305 * if we see {, we call parse_group(..., end_trigger='}')
5306 * and it will match } earlier (not here). */
5307 G.last_exitcode = 2;
5308 syntax_error_unexpected_ch(ch);
5312 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5317 G.last_exitcode = 1;
5320 struct parse_context *pctx;
5321 IF_HAS_KEYWORDS(struct parse_context *p2;)
5323 /* Clean up allocated tree.
5324 * Sample for finding leaks on syntax error recovery path.
5325 * Run it from interactive shell, watch pmap `pidof hush`.
5326 * while if false; then false; fi; do break; fi
5327 * Samples to catch leaks at execution:
5328 * while if (true | { true;}); then echo ok; fi; do break; done
5329 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5333 /* Update pipe/command counts,
5334 * otherwise freeing may miss some */
5335 done_pipe(pctx, PIPE_SEQ);
5336 debug_printf_clean("freeing list %p from ctx %p\n",
5337 pctx->list_head, pctx);
5338 debug_print_tree(pctx->list_head, 0);
5339 free_pipe_list(pctx->list_head);
5340 debug_printf_clean("freed list %p\n", pctx->list_head);
5342 o_free_unsafe(&pctx->as_string);
5344 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5348 IF_HAS_KEYWORDS(pctx = p2;)
5349 } while (HAS_KEYWORDS && pctx);
5362 /*** Execution routines ***/
5364 /* Expansion can recurse, need forward decls: */
5365 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5366 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5367 #define expand_string_to_string(str, do_unbackslash) \
5368 expand_string_to_string(str)
5370 static char *expand_string_to_string(const char *str, int do_unbackslash);
5371 #if ENABLE_HUSH_TICK
5372 static int process_command_subs(o_string *dest, const char *s);
5375 /* expand_strvec_to_strvec() takes a list of strings, expands
5376 * all variable references within and returns a pointer to
5377 * a list of expanded strings, possibly with larger number
5378 * of strings. (Think VAR="a b"; echo $VAR).
5379 * This new list is allocated as a single malloc block.
5380 * NULL-terminated list of char* pointers is at the beginning of it,
5381 * followed by strings themselves.
5382 * Caller can deallocate entire list by single free(list). */
5384 /* A horde of its helpers come first: */
5386 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5388 while (--len >= 0) {
5391 #if ENABLE_HUSH_BRACE_EXPANSION
5392 if (c == '{' || c == '}') {
5393 /* { -> \{, } -> \} */
5395 /* And now we want to add { or } and continue:
5398 * luckily, just falling through achieves this.
5404 /* \z -> \\\z; \<eol> -> \\<eol> */
5409 o_addchr(o, *str++);
5415 /* Store given string, finalizing the word and starting new one whenever
5416 * we encounter IFS char(s). This is used for expanding variable values.
5417 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5418 * Return in *ended_with_ifs:
5419 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5421 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5423 int last_is_ifs = 0;
5428 if (!*str) /* EOL - do not finalize word */
5430 word_len = strcspn(str, G.ifs);
5432 /* We have WORD_LEN leading non-IFS chars */
5433 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5434 o_addblock(output, str, word_len);
5436 /* Protect backslashes against globbing up :)
5437 * Example: "v='\*'; echo b$v" prints "b\*"
5438 * (and does not try to glob on "*")
5440 o_addblock_duplicate_backslash(output, str, word_len);
5441 /*/ Why can't we do it easier? */
5442 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5443 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5447 if (!*str) /* EOL - do not finalize word */
5451 /* We know str here points to at least one IFS char */
5453 str += strspn(str, G.ifs); /* skip IFS chars */
5454 if (!*str) /* EOL - do not finalize word */
5457 /* Start new word... but not always! */
5458 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5459 if (output->has_quoted_part
5460 /* Case "v=' a'; echo $v":
5461 * here nothing precedes the space in $v expansion,
5462 * therefore we should not finish the word
5463 * (IOW: if there *is* word to finalize, only then do it):
5465 || (n > 0 && output->data[output->length - 1])
5467 o_addchr(output, '\0');
5468 debug_print_list("expand_on_ifs", output, n);
5469 n = o_save_ptr(output, n);
5474 *ended_with_ifs = last_is_ifs;
5475 debug_print_list("expand_on_ifs[1]", output, n);
5479 /* Helper to expand $((...)) and heredoc body. These act as if
5480 * they are in double quotes, with the exception that they are not :).
5481 * Just the rules are similar: "expand only $var and `cmd`"
5483 * Returns malloced string.
5484 * As an optimization, we return NULL if expansion is not needed.
5486 #if !BASH_PATTERN_SUBST
5487 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5488 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5489 encode_then_expand_string(str)
5491 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5493 #if !BASH_PATTERN_SUBST
5494 const int do_unbackslash = 1;
5497 struct in_str input;
5498 o_string dest = NULL_O_STRING;
5500 if (!strchr(str, '$')
5501 && !strchr(str, '\\')
5502 #if ENABLE_HUSH_TICK
5503 && !strchr(str, '`')
5509 /* We need to expand. Example:
5510 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5512 setup_string_in_str(&input, str);
5513 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5514 //TODO: error check (encode_string returns 0 on error)?
5515 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5516 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5517 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5518 o_free_unsafe(&dest);
5522 #if ENABLE_FEATURE_SH_MATH
5523 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5525 arith_state_t math_state;
5529 math_state.lookupvar = get_local_var_value;
5530 math_state.setvar = set_local_var_from_halves;
5531 //math_state.endofname = endofname;
5532 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5533 res = arith(&math_state, exp_str ? exp_str : arg);
5536 *errmsg_p = math_state.errmsg;
5537 if (math_state.errmsg)
5538 msg_and_die_if_script(math_state.errmsg);
5543 #if BASH_PATTERN_SUBST
5544 /* ${var/[/]pattern[/repl]} helpers */
5545 static char *strstr_pattern(char *val, const char *pattern, int *size)
5548 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5549 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5556 /* Optimization: if "*pat" did not match the start of "string",
5557 * we know that "tring", "ring" etc will not match too:
5559 if (pattern[0] == '*')
5564 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5566 char *result = NULL;
5567 unsigned res_len = 0;
5568 unsigned repl_len = strlen(repl);
5572 char *s = strstr_pattern(val, pattern, &size);
5576 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5577 strcpy(mempcpy(result + res_len, val, s - val), repl);
5578 res_len += (s - val) + repl_len;
5579 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5585 if (*val && result) {
5586 result = xrealloc(result, res_len + strlen(val) + 1);
5587 strcpy(result + res_len, val);
5588 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5590 debug_printf_varexp("result:'%s'\n", result);
5593 #endif /* BASH_PATTERN_SUBST */
5596 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5598 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5600 const char *val = NULL;
5601 char *to_be_freed = NULL;
5606 char exp_save = exp_save; /* for compiler */
5607 char *exp_saveptr; /* points to expansion operator */
5608 char *exp_word = exp_word; /* for compiler */
5611 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5613 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5615 first_char = arg[0] = arg0 & 0x7f;
5618 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5619 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5620 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5621 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5623 /* It must be length operator: ${#var} */
5627 /* Maybe handle parameter expansion */
5628 if (exp_saveptr /* if 2nd char is one of expansion operators */
5629 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5631 /* ${?:0}, ${#[:]%0} etc */
5632 exp_saveptr = var + 1;
5634 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5635 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5637 exp_op = exp_save = *exp_saveptr;
5639 exp_word = exp_saveptr + 1;
5640 if (exp_op == ':') {
5641 exp_op = *exp_word++;
5642 //TODO: try ${var:} and ${var:bogus} in non-bash config
5644 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5646 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5651 *exp_saveptr = '\0';
5652 } /* else: it's not an expansion op, but bare ${var} */
5655 /* Look up the variable in question */
5656 if (isdigit(var[0])) {
5657 /* parse_dollar should have vetted var for us */
5658 int n = xatoi_positive(var);
5659 if (n < G.global_argc)
5660 val = G.global_argv[n];
5661 /* else val remains NULL: $N with too big N */
5665 val = utoa(G.root_pid);
5667 case '!': /* bg pid */
5668 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5670 case '?': /* exitcode */
5671 val = utoa(G.last_exitcode);
5673 case '#': /* argc */
5674 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5677 val = get_local_var_value(var);
5681 /* Handle any expansions */
5682 if (exp_op == 'L') {
5683 reinit_unicode_for_hush();
5684 debug_printf_expand("expand: length(%s)=", val);
5685 val = utoa(val ? unicode_strlen(val) : 0);
5686 debug_printf_expand("%s\n", val);
5687 } else if (exp_op) {
5688 if (exp_op == '%' || exp_op == '#') {
5689 /* Standard-mandated substring removal ops:
5690 * ${parameter%word} - remove smallest suffix pattern
5691 * ${parameter%%word} - remove largest suffix pattern
5692 * ${parameter#word} - remove smallest prefix pattern
5693 * ${parameter##word} - remove largest prefix pattern
5695 * Word is expanded to produce a glob pattern.
5696 * Then var's value is matched to it and matching part removed.
5698 if (val && val[0]) {
5702 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5703 if (exp_op == *exp_word) /* ## or %% */
5705 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5707 exp_word = exp_exp_word;
5708 /* HACK ALERT. We depend here on the fact that
5709 * G.global_argv and results of utoa and get_local_var_value
5710 * are actually in writable memory:
5711 * scan_and_match momentarily stores NULs there. */
5713 loc = scan_and_match(t, exp_word, scan_flags);
5714 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5715 // exp_op, t, exp_word, loc);
5717 if (loc) { /* match was found */
5718 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5719 val = loc; /* take right part */
5721 val = to_be_freed = xstrndup(val, loc - val); /* left */
5725 #if BASH_PATTERN_SUBST
5726 else if (exp_op == '/' || exp_op == '\\') {
5727 /* It's ${var/[/]pattern[/repl]} thing.
5728 * Note that in encoded form it has TWO parts:
5729 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5730 * and if // is used, it is encoded as \:
5731 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5733 /* Empty variable always gives nothing: */
5734 // "v=''; echo ${v/*/w}" prints "", not "w"
5735 if (val && val[0]) {
5736 /* pattern uses non-standard expansion.
5737 * repl should be unbackslashed and globbed
5738 * by the usual expansion rules:
5740 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5741 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5742 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5743 * v='a bz'; echo ${v/a*z/\z} prints "z"
5744 * (note that a*z _pattern_ is never globbed!)
5746 char *pattern, *repl, *t;
5747 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5749 pattern = xstrdup(exp_word);
5750 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5751 *p++ = SPECIAL_VAR_SYMBOL;
5753 p = strchr(p, SPECIAL_VAR_SYMBOL);
5755 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5756 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5757 /* HACK ALERT. We depend here on the fact that
5758 * G.global_argv and results of utoa and get_local_var_value
5759 * are actually in writable memory:
5760 * replace_pattern momentarily stores NULs there. */
5762 to_be_freed = replace_pattern(t,
5764 (repl ? repl : exp_word),
5766 if (to_be_freed) /* at least one replace happened */
5772 #endif /* BASH_PATTERN_SUBST */
5773 else if (exp_op == ':') {
5774 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5775 /* It's ${var:N[:M]} bashism.
5776 * Note that in encoded form it has TWO parts:
5777 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5782 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5785 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5786 *p++ = SPECIAL_VAR_SYMBOL;
5788 p = strchr(p, SPECIAL_VAR_SYMBOL);
5790 len = expand_and_evaluate_arith(exp_word, &errmsg);
5793 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5795 /* negative beg counts from the end */
5796 beg = (arith_t)strlen(val) + beg;
5797 if (beg < 0) /* ${v: -999999} is "" */
5800 debug_printf_varexp("from val:'%s'\n", val);
5802 /* in bash, len=-n means strlen()-n */
5803 len = (arith_t)strlen(val) - beg + len;
5804 if (len < 0) /* bash compat */
5805 msg_and_die_if_script("%s: substring expression < 0", var);
5807 if (len <= 0 || !val || beg >= strlen(val)) {
5811 /* Paranoia. What if user entered 9999999999999
5812 * which fits in arith_t but not int? */
5815 val = to_be_freed = xstrndup(val + beg, len);
5817 debug_printf_varexp("val:'%s'\n", val);
5818 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5819 msg_and_die_if_script("malformed ${%s:...}", var);
5822 } else { /* one of "-=+?" */
5823 /* Standard-mandated substitution ops:
5824 * ${var?word} - indicate error if unset
5825 * If var is unset, word (or a message indicating it is unset
5826 * if word is null) is written to standard error
5827 * and the shell exits with a non-zero exit status.
5828 * Otherwise, the value of var is substituted.
5829 * ${var-word} - use default value
5830 * If var is unset, word is substituted.
5831 * ${var=word} - assign and use default value
5832 * If var is unset, word is assigned to var.
5833 * In all cases, final value of var is substituted.
5834 * ${var+word} - use alternative value
5835 * If var is unset, null is substituted.
5836 * Otherwise, word is substituted.
5838 * Word is subjected to tilde expansion, parameter expansion,
5839 * command substitution, and arithmetic expansion.
5840 * If word is not needed, it is not expanded.
5842 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5843 * but also treat null var as if it is unset.
5845 int use_word = (!val || ((exp_save == ':') && !val[0]));
5847 use_word = !use_word;
5848 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5849 (exp_save == ':') ? "true" : "false", use_word);
5851 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5853 exp_word = to_be_freed;
5854 if (exp_op == '?') {
5855 /* mimic bash message */
5856 msg_and_die_if_script("%s: %s",
5860 : "parameter null or not set"
5861 /* ash has more specific messages, a-la: */
5862 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5864 //TODO: how interactive bash aborts expansion mid-command?
5869 if (exp_op == '=') {
5870 /* ${var=[word]} or ${var:=[word]} */
5871 if (isdigit(var[0]) || var[0] == '#') {
5872 /* mimic bash message */
5873 msg_and_die_if_script("$%s: cannot assign in this way", var);
5876 char *new_var = xasprintf("%s=%s", var, val);
5877 set_local_var(new_var, /*flag:*/ 0);
5881 } /* one of "-=+?" */
5883 *exp_saveptr = exp_save;
5889 *to_be_freed_pp = to_be_freed;
5893 /* Expand all variable references in given string, adding words to list[]
5894 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5895 * to be filled). This routine is extremely tricky: has to deal with
5896 * variables/parameters with whitespace, $* and $@, and constructs like
5897 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5898 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5900 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5901 * expansion of right-hand side of assignment == 1-element expand.
5903 char cant_be_null = 0; /* only bit 0x80 matters */
5904 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5907 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5908 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5909 debug_print_list("expand_vars_to_list", output, n);
5910 n = o_save_ptr(output, n);
5911 debug_print_list("expand_vars_to_list[0]", output, n);
5913 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5915 char *to_be_freed = NULL;
5916 const char *val = NULL;
5917 #if ENABLE_HUSH_TICK
5918 o_string subst_result = NULL_O_STRING;
5920 #if ENABLE_FEATURE_SH_MATH
5921 char arith_buf[sizeof(arith_t)*3 + 2];
5925 o_addchr(output, '\0');
5926 n = o_save_ptr(output, n);
5930 o_addblock(output, arg, p - arg);
5931 debug_print_list("expand_vars_to_list[1]", output, n);
5933 p = strchr(p, SPECIAL_VAR_SYMBOL);
5935 /* Fetch special var name (if it is indeed one of them)
5936 * and quote bit, force the bit on if singleword expansion -
5937 * important for not getting v=$@ expand to many words. */
5938 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5940 /* Is this variable quoted and thus expansion can't be null?
5941 * "$@" is special. Even if quoted, it can still
5942 * expand to nothing (not even an empty string),
5943 * thus it is excluded. */
5944 if ((first_ch & 0x7f) != '@')
5945 cant_be_null |= first_ch;
5947 switch (first_ch & 0x7f) {
5948 /* Highest bit in first_ch indicates that var is double-quoted */
5952 if (!G.global_argv[1])
5955 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5956 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5957 while (G.global_argv[i]) {
5958 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5959 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5960 if (G.global_argv[i++][0] && G.global_argv[i]) {
5961 /* this argv[] is not empty and not last:
5962 * put terminating NUL, start new word */
5963 o_addchr(output, '\0');
5964 debug_print_list("expand_vars_to_list[2]", output, n);
5965 n = o_save_ptr(output, n);
5966 debug_print_list("expand_vars_to_list[3]", output, n);
5970 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5971 * and in this case should treat it like '$*' - see 'else...' below */
5972 if (first_ch == ('@'|0x80) /* quoted $@ */
5973 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5976 o_addQstr(output, G.global_argv[i]);
5977 if (++i >= G.global_argc)
5979 o_addchr(output, '\0');
5980 debug_print_list("expand_vars_to_list[4]", output, n);
5981 n = o_save_ptr(output, n);
5983 } else { /* quoted $* (or v="$@" case): add as one word */
5985 o_addQstr(output, G.global_argv[i]);
5986 if (!G.global_argv[++i])
5989 o_addchr(output, G.ifs[0]);
5991 output->has_quoted_part = 1;
5995 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5996 /* "Empty variable", used to make "" etc to not disappear */
5997 output->has_quoted_part = 1;
5999 cant_be_null = 0x80;
6001 #if ENABLE_HUSH_TICK
6002 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6003 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6005 /* Can't just stuff it into output o_string,
6006 * expanded result may need to be globbed
6008 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6009 G.last_exitcode = process_command_subs(&subst_result, arg);
6010 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6011 val = subst_result.data;
6014 #if ENABLE_FEATURE_SH_MATH
6015 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6018 arg++; /* skip '+' */
6019 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6020 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6021 res = expand_and_evaluate_arith(arg, NULL);
6022 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6023 sprintf(arith_buf, ARITH_FMT, res);
6029 val = expand_one_var(&to_be_freed, arg, &p);
6030 IF_HUSH_TICK(store_val:)
6031 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6032 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6033 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6034 if (val && val[0]) {
6035 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6038 } else { /* quoted $VAR, val will be appended below */
6039 output->has_quoted_part = 1;
6040 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6041 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6044 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6046 if (val && val[0]) {
6047 o_addQstr(output, val);
6051 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6052 * Do the check to avoid writing to a const string. */
6053 if (*p != SPECIAL_VAR_SYMBOL)
6054 *p = SPECIAL_VAR_SYMBOL;
6056 #if ENABLE_HUSH_TICK
6057 o_free(&subst_result);
6060 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6064 o_addchr(output, '\0');
6065 n = o_save_ptr(output, n);
6067 debug_print_list("expand_vars_to_list[a]", output, n);
6068 /* this part is literal, and it was already pre-quoted
6069 * if needed (much earlier), do not use o_addQstr here! */
6070 o_addstr_with_NUL(output, arg);
6071 debug_print_list("expand_vars_to_list[b]", output, n);
6072 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6073 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6076 /* allow to reuse list[n] later without re-growth */
6077 output->has_empty_slot = 1;
6079 o_addchr(output, '\0');
6085 static char **expand_variables(char **argv, unsigned expflags)
6089 o_string output = NULL_O_STRING;
6091 output.o_expflags = expflags;
6095 n = expand_vars_to_list(&output, n, *argv);
6098 debug_print_list("expand_variables", &output, n);
6100 /* output.data (malloced in one block) gets returned in "list" */
6101 list = o_finalize_list(&output, n);
6102 debug_print_strings("expand_variables[1]", list);
6106 static char **expand_strvec_to_strvec(char **argv)
6108 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6112 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6114 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6118 /* Used for expansion of right hand of assignments,
6119 * $((...)), heredocs, variable espansion parts.
6121 * NB: should NOT do globbing!
6122 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6124 static char *expand_string_to_string(const char *str, int do_unbackslash)
6126 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6127 const int do_unbackslash = 1;
6129 char *argv[2], **list;
6131 debug_printf_expand("string_to_string<='%s'\n", str);
6132 /* This is generally an optimization, but it also
6133 * handles "", which otherwise trips over !list[0] check below.
6134 * (is this ever happens that we actually get str="" here?)
6136 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6137 //TODO: Can use on strings with \ too, just unbackslash() them?
6138 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6139 return xstrdup(str);
6142 argv[0] = (char*)str;
6144 list = expand_variables(argv, do_unbackslash
6145 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6146 : EXP_FLAG_SINGLEWORD
6149 if (!list[0] || list[1])
6150 bb_error_msg_and_die("BUG in varexp2");
6151 /* actually, just move string 2*sizeof(char*) bytes back */
6152 overlapping_strcpy((char*)list, list[0]);
6154 unbackslash((char*)list);
6155 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6159 /* Used for "eval" builtin and case string */
6160 static char* expand_strvec_to_string(char **argv)
6164 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6165 /* Convert all NULs to spaces */
6170 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6171 bb_error_msg_and_die("BUG in varexp3");
6172 /* bash uses ' ' regardless of $IFS contents */
6177 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6178 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6182 static char **expand_assignments(char **argv, int count)
6187 G.expanded_assignments = p = NULL;
6188 /* Expand assignments into one string each */
6189 for (i = 0; i < count; i++) {
6190 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6192 G.expanded_assignments = NULL;
6197 static void switch_off_special_sigs(unsigned mask)
6200 while ((mask >>= 1) != 0) {
6204 #if ENABLE_HUSH_TRAP
6206 if (G_traps[sig] && !G_traps[sig][0])
6207 /* trap is '', has to remain SIG_IGN */
6210 G_traps[sig] = NULL;
6213 /* We are here only if no trap or trap was not '' */
6214 install_sighandler(sig, SIG_DFL);
6220 void re_execute_shell(char ***to_free, const char *s,
6221 char *g_argv0, char **g_argv,
6222 char **builtin_argv) NORETURN;
6224 static void reset_traps_to_defaults(void)
6226 /* This function is always called in a child shell
6227 * after fork (not vfork, NOMMU doesn't use this function).
6229 IF_HUSH_TRAP(unsigned sig;)
6232 /* Child shells are not interactive.
6233 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6234 * Testcase: (while :; do :; done) + ^Z should background.
6235 * Same goes for SIGTERM, SIGHUP, SIGINT.
6237 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6238 if (!G_traps && !mask)
6239 return; /* already no traps and no special sigs */
6241 /* Switch off special sigs */
6242 switch_off_special_sigs(mask);
6243 # if ENABLE_HUSH_JOB
6244 G_fatal_sig_mask = 0;
6246 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6247 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6248 * remain set in G.special_sig_mask */
6250 # if ENABLE_HUSH_TRAP
6254 /* Reset all sigs to default except ones with empty traps */
6255 for (sig = 0; sig < NSIG; sig++) {
6257 continue; /* no trap: nothing to do */
6258 if (!G_traps[sig][0])
6259 continue; /* empty trap: has to remain SIG_IGN */
6260 /* sig has non-empty trap, reset it: */
6262 G_traps[sig] = NULL;
6263 /* There is no signal for trap 0 (EXIT) */
6266 install_sighandler(sig, pick_sighandler(sig));
6273 static void re_execute_shell(char ***to_free, const char *s,
6274 char *g_argv0, char **g_argv,
6275 char **builtin_argv) NORETURN;
6276 static void re_execute_shell(char ***to_free, const char *s,
6277 char *g_argv0, char **g_argv,
6278 char **builtin_argv)
6280 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6281 /* delims + 2 * (number of bytes in printed hex numbers) */
6282 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6283 char *heredoc_argv[4];
6284 struct variable *cur;
6285 # if ENABLE_HUSH_FUNCTIONS
6286 struct function *funcp;
6290 unsigned long long empty_trap_mask;
6292 if (!g_argv0) { /* heredoc */
6293 argv = heredoc_argv;
6294 argv[0] = (char *) G.argv0_for_re_execing;
6295 argv[1] = (char *) "-<";
6296 argv[2] = (char *) s;
6298 pp = &argv[3]; /* used as pointer to empty environment */
6304 if (pp) while (*pp++)
6307 empty_trap_mask = 0;
6310 for (sig = 1; sig < NSIG; sig++) {
6311 if (G_traps[sig] && !G_traps[sig][0])
6312 empty_trap_mask |= 1LL << sig;
6316 sprintf(param_buf, NOMMU_HACK_FMT
6317 , (unsigned) G.root_pid
6318 , (unsigned) G.root_ppid
6319 , (unsigned) G.last_bg_pid
6320 , (unsigned) G.last_exitcode
6323 IF_HUSH_LOOPS(, G.depth_of_loop)
6325 # undef NOMMU_HACK_FMT
6326 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6327 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6330 for (cur = G.top_var; cur; cur = cur->next) {
6331 if (!cur->flg_export || cur->flg_read_only)
6334 # if ENABLE_HUSH_FUNCTIONS
6335 for (funcp = G.top_func; funcp; funcp = funcp->next)
6341 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6342 *pp++ = (char *) G.argv0_for_re_execing;
6344 for (cur = G.top_var; cur; cur = cur->next) {
6345 if (strcmp(cur->varstr, hush_version_str) == 0)
6347 if (cur->flg_read_only) {
6348 *pp++ = (char *) "-R";
6349 *pp++ = cur->varstr;
6350 } else if (!cur->flg_export) {
6351 *pp++ = (char *) "-V";
6352 *pp++ = cur->varstr;
6355 # if ENABLE_HUSH_FUNCTIONS
6356 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6357 *pp++ = (char *) "-F";
6358 *pp++ = funcp->name;
6359 *pp++ = funcp->body_as_string;
6362 /* We can pass activated traps here. Say, -Tnn:trap_string
6364 * However, POSIX says that subshells reset signals with traps
6366 * I tested bash-3.2 and it not only does that with true subshells
6367 * of the form ( list ), but with any forked children shells.
6368 * I set trap "echo W" WINCH; and then tried:
6370 * { echo 1; sleep 20; echo 2; } &
6371 * while true; do echo 1; sleep 20; echo 2; break; done &
6372 * true | { echo 1; sleep 20; echo 2; } | cat
6374 * In all these cases sending SIGWINCH to the child shell
6375 * did not run the trap. If I add trap "echo V" WINCH;
6376 * _inside_ group (just before echo 1), it works.
6378 * I conclude it means we don't need to pass active traps here.
6380 *pp++ = (char *) "-c";
6383 while (*++builtin_argv)
6384 *pp++ = *builtin_argv;
6385 *pp++ = (char *) "";
6390 /* *pp = NULL; - is already there */
6394 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6395 /* Don't propagate SIG_IGN to the child */
6396 if (SPECIAL_JOBSTOP_SIGS != 0)
6397 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6398 execve(bb_busybox_exec_path, argv, pp);
6399 /* Fallback. Useful for init=/bin/hush usage etc */
6400 if (argv[0][0] == '/')
6401 execve(argv[0], argv, pp);
6402 xfunc_error_retval = 127;
6403 bb_error_msg_and_die("can't re-execute the shell");
6405 #endif /* !BB_MMU */
6408 static int run_and_free_list(struct pipe *pi);
6410 /* Executing from string: eval, sh -c '...'
6411 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6412 * end_trigger controls how often we stop parsing
6413 * NUL: parse all, execute, return
6414 * ';': parse till ';' or newline, execute, repeat till EOF
6416 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6418 /* Why we need empty flag?
6419 * An obscure corner case "false; ``; echo $?":
6420 * empty command in `` should still set $? to 0.
6421 * But we can't just set $? to 0 at the start,
6422 * this breaks "false; echo `echo $?`" case.
6426 struct pipe *pipe_list;
6428 #if ENABLE_HUSH_INTERACTIVE
6429 if (end_trigger == ';')
6430 inp->promptmode = 0; /* PS1 */
6432 pipe_list = parse_stream(NULL, inp, end_trigger);
6433 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6434 /* If we are in "big" script
6435 * (not in `cmd` or something similar)...
6437 if (pipe_list == ERR_PTR && end_trigger == ';') {
6438 /* Discard cached input (rest of line) */
6439 int ch = inp->last_char;
6440 while (ch != EOF && ch != '\n') {
6441 //bb_error_msg("Discarded:'%c'", ch);
6446 /* This stream isn't empty */
6450 if (!pipe_list && empty)
6451 G.last_exitcode = 0;
6454 debug_print_tree(pipe_list, 0);
6455 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6456 run_and_free_list(pipe_list);
6458 if (G_flag_return_in_progress == 1)
6463 static void parse_and_run_string(const char *s)
6465 struct in_str input;
6466 setup_string_in_str(&input, s);
6467 parse_and_run_stream(&input, '\0');
6470 static void parse_and_run_file(FILE *f)
6472 struct in_str input;
6473 setup_file_in_str(&input, f);
6474 parse_and_run_stream(&input, ';');
6477 #if ENABLE_HUSH_TICK
6478 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6483 char **to_free = NULL;
6487 pid = BB_MMU ? xfork() : xvfork();
6488 if (pid == 0) { /* child */
6489 disable_restore_tty_pgrp_on_exit();
6490 /* Process substitution is not considered to be usual
6491 * 'command execution'.
6492 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6499 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6500 close(channel[0]); /* NB: close _first_, then move fd! */
6501 xmove_fd(channel[1], 1);
6502 /* Prevent it from trying to handle ctrl-z etc */
6503 IF_HUSH_JOB(G.run_list_level = 1;)
6504 # if ENABLE_HUSH_TRAP
6505 /* Awful hack for `trap` or $(trap).
6507 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6508 * contains an example where "trap" is executed in a subshell:
6510 * save_traps=$(trap)
6512 * eval "$save_traps"
6514 * Standard does not say that "trap" in subshell shall print
6515 * parent shell's traps. It only says that its output
6516 * must have suitable form, but then, in the above example
6517 * (which is not supposed to be normative), it implies that.
6519 * bash (and probably other shell) does implement it
6520 * (traps are reset to defaults, but "trap" still shows them),
6521 * but as a result, "trap" logic is hopelessly messed up:
6524 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6525 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6526 * # true | trap <--- trap is in subshell - no output (ditto)
6527 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6528 * trap -- 'echo Ho' SIGWINCH
6529 * # echo `(trap)` <--- in subshell in subshell - output
6530 * trap -- 'echo Ho' SIGWINCH
6531 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6532 * trap -- 'echo Ho' SIGWINCH
6534 * The rules when to forget and when to not forget traps
6535 * get really complex and nonsensical.
6537 * Our solution: ONLY bare $(trap) or `trap` is special.
6539 s = skip_whitespace(s);
6540 if (is_prefixed_with(s, "trap")
6541 && skip_whitespace(s + 4)[0] == '\0'
6543 static const char *const argv[] = { NULL, NULL };
6544 builtin_trap((char**)argv);
6545 fflush_all(); /* important */
6550 reset_traps_to_defaults();
6551 parse_and_run_string(s);
6552 _exit(G.last_exitcode);
6554 /* We re-execute after vfork on NOMMU. This makes this script safe:
6555 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6556 * huge=`cat BIG` # was blocking here forever
6559 re_execute_shell(&to_free,
6569 # if ENABLE_HUSH_FAST
6571 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6572 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6573 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6575 enable_restore_tty_pgrp_on_exit();
6580 return remember_FILE(xfdopen_for_read(channel[0]));
6583 /* Return code is exit status of the process that is run. */
6584 static int process_command_subs(o_string *dest, const char *s)
6587 struct in_str pipe_str;
6589 int status, ch, eol_cnt;
6591 fp = generate_stream_from_string(s, &pid);
6593 /* Now send results of command back into original context */
6594 setup_file_in_str(&pipe_str, fp);
6596 while ((ch = i_getch(&pipe_str)) != EOF) {
6602 o_addchr(dest, '\n');
6605 o_addQchr(dest, ch);
6608 debug_printf("done reading from `cmd` pipe, closing it\n");
6609 fclose_and_forget(fp);
6610 /* We need to extract exitcode. Test case
6611 * "true; echo `sleep 1; false` $?"
6613 safe_waitpid(pid, &status, 0);
6614 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6615 return WEXITSTATUS(status);
6617 #endif /* ENABLE_HUSH_TICK */
6620 static void setup_heredoc(struct redir_struct *redir)
6622 struct fd_pair pair;
6625 /* the _body_ of heredoc (misleading field name) */
6626 const char *heredoc = redir->rd_filename;
6633 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6634 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6638 len = strlen(heredoc);
6640 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6642 xmove_fd(pair.rd, redir->rd_fd);
6644 /* Try writing without forking. Newer kernels have
6645 * dynamically growing pipes. Must use non-blocking write! */
6648 written = write(pair.wr, heredoc, len);
6659 ndelay_off(pair.wr);
6661 /* Okay, pipe buffer was not big enough */
6662 /* Note: we must not create a stray child (bastard? :)
6663 * for the unsuspecting parent process. Child creates a grandchild
6664 * and exits before parent execs the process which consumes heredoc
6665 * (that exec happens after we return from this function) */
6672 disable_restore_tty_pgrp_on_exit();
6673 pid = BB_MMU ? xfork() : xvfork();
6677 close(redir->rd_fd); /* read side of the pipe */
6679 full_write(pair.wr, heredoc, len); /* may loop or block */
6682 /* Delegate blocking writes to another process */
6683 xmove_fd(pair.wr, STDOUT_FILENO);
6684 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6688 #if ENABLE_HUSH_FAST
6690 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6692 enable_restore_tty_pgrp_on_exit();
6698 wait(NULL); /* wait till child has died */
6704 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6705 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6708 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6710 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6711 sq[i].orig_fd = orig;
6712 sq[i].moved_to = moved;
6713 sq[i+1].orig_fd = -1; /* end marker */
6717 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6722 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6723 /* If we collide with an already moved fd... */
6724 if (fd == sq[i].moved_to) {
6725 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6726 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6727 if (sq[i].moved_to < 0) /* what? */
6731 if (fd == sq[i].orig_fd) {
6732 /* Example: echo Hello >/dev/null 1>&2 */
6733 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6738 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6739 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6740 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6741 if (moved_to < 0 && errno != EBADF)
6743 return append_squirrel(sq, i, fd, moved_to);
6746 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6750 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6751 /* If we collide with an already moved fd... */
6752 if (fd == sq[i].orig_fd) {
6754 * "echo 3>FILE 3>&- 3>FILE"
6755 * "echo 3>&- 3>FILE"
6756 * No need for last redirect to insert
6757 * another "need to close 3" indicator.
6759 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6764 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6765 return append_squirrel(sq, i, fd, -1);
6768 /* fd: redirect wants this fd to be used (e.g. 3>file).
6769 * Move all conflicting internally used fds,
6770 * and remember them so that we can restore them later.
6772 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6774 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6777 #if ENABLE_HUSH_INTERACTIVE
6778 if (fd == G.interactive_fd) {
6779 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6780 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6781 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6782 return 1; /* "we closed fd" */
6785 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6786 * (1) Redirect in a forked child. No need to save FILEs' fds,
6787 * we aren't going to use them anymore, ok to trash.
6788 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6789 * but how are we doing to restore them?
6790 * "fileno(fd) = new_fd" can't be done.
6795 /* If this one of script's fds? */
6796 if (save_FILEs_on_redirect(fd, avoid_fd))
6797 return 1; /* yes. "we closed fd" */
6799 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6800 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6801 return 0; /* "we did not close fd" */
6804 static void restore_redirects(struct squirrel *sq)
6808 for (i = 0; sq[i].orig_fd >= 0; i++) {
6809 if (sq[i].moved_to >= 0) {
6810 /* We simply die on error */
6811 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6812 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6814 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6815 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6816 close(sq[i].orig_fd);
6822 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6824 restore_redirected_FILEs();
6827 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6828 static void close_saved_fds_and_FILE_fds(void)
6830 if (G_interactive_fd)
6831 close(G_interactive_fd);
6832 close_all_FILE_list();
6836 static int internally_opened_fd(int fd, struct squirrel *sq)
6840 #if ENABLE_HUSH_INTERACTIVE
6841 if (fd == G.interactive_fd)
6844 /* If this one of script's fds? */
6845 if (fd_in_FILEs(fd))
6848 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6849 if (fd == sq[i].moved_to)
6855 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6856 * and stderr if they are redirected. */
6857 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6859 struct redir_struct *redir;
6861 for (redir = prog->redirects; redir; redir = redir->next) {
6865 if (redir->rd_type == REDIRECT_HEREDOC2) {
6866 /* "rd_fd<<HERE" case */
6867 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6868 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6870 debug_printf_parse("set heredoc '%s'\n",
6871 redir->rd_filename);
6872 setup_heredoc(redir);
6876 if (redir->rd_dup == REDIRFD_TO_FILE) {
6877 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6881 if (redir->rd_filename == NULL) {
6884 * "cmd >" (no filename)
6885 * "cmd > <file" (2nd redirect starts too early)
6887 syntax_error("invalid redirect");
6890 mode = redir_table[redir->rd_type].mode;
6891 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6892 newfd = open_or_warn(p, mode);
6895 /* Error message from open_or_warn can be lost
6896 * if stderr has been redirected, but bash
6897 * and ash both lose it as well
6898 * (though zsh doesn't!)
6902 if (newfd == redir->rd_fd && sqp) {
6903 /* open() gave us precisely the fd we wanted.
6904 * This means that this fd was not busy
6905 * (not opened to anywhere).
6906 * Remember to close it on restore:
6908 *sqp = add_squirrel_closed(*sqp, newfd);
6909 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6912 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6913 newfd = redir->rd_dup;
6916 if (newfd == redir->rd_fd)
6919 /* if "N>FILE": move newfd to redir->rd_fd */
6920 /* if "N>&M": dup newfd to redir->rd_fd */
6921 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6923 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6924 if (newfd == REDIRFD_CLOSE) {
6925 /* "N>&-" means "close me" */
6927 /* ^^^ optimization: saving may already
6928 * have closed it. If not... */
6929 close(redir->rd_fd);
6931 /* Sometimes we do another close on restore, getting EBADF.
6932 * Consider "echo 3>FILE 3>&-"
6933 * first redirect remembers "need to close 3",
6934 * and second redirect closes 3! Restore code then closes 3 again.
6937 /* if newfd is a script fd or saved fd, simulate EBADF */
6938 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6940 //bb_perror_msg_and_die("can't duplicate file descriptor");
6941 newfd = -1; /* same effect as code above */
6943 xdup2(newfd, redir->rd_fd);
6944 if (redir->rd_dup == REDIRFD_TO_FILE)
6945 /* "rd_fd > FILE" */
6947 /* else: "rd_fd > rd_dup" */
6953 static char *find_in_path(const char *arg)
6956 const char *PATH = get_local_var_value("PATH");
6962 const char *end = strchrnul(PATH, ':');
6963 int sz = end - PATH; /* must be int! */
6967 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6969 /* We have xxx::yyyy in $PATH,
6970 * it means "use current dir" */
6973 if (access(ret, F_OK) == 0)
6986 static const struct built_in_command *find_builtin_helper(const char *name,
6987 const struct built_in_command *x,
6988 const struct built_in_command *end)
6991 if (strcmp(name, x->b_cmd) != 0) {
6995 debug_printf_exec("found builtin '%s'\n", name);
7000 static const struct built_in_command *find_builtin1(const char *name)
7002 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7004 static const struct built_in_command *find_builtin(const char *name)
7006 const struct built_in_command *x = find_builtin1(name);
7009 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7012 #if ENABLE_HUSH_FUNCTIONS
7013 static struct function **find_function_slot(const char *name)
7015 struct function **funcpp = &G.top_func;
7017 if (strcmp(name, (*funcpp)->name) == 0) {
7020 funcpp = &(*funcpp)->next;
7025 static const struct function *find_function(const char *name)
7027 const struct function *funcp = *find_function_slot(name);
7029 debug_printf_exec("found function '%s'\n", name);
7033 /* Note: takes ownership on name ptr */
7034 static struct function *new_function(char *name)
7036 struct function **funcpp = find_function_slot(name);
7037 struct function *funcp = *funcpp;
7039 if (funcp != NULL) {
7040 struct command *cmd = funcp->parent_cmd;
7041 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7043 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7045 /* Note: if !funcp->body, do not free body_as_string!
7046 * This is a special case of "-F name body" function:
7047 * body_as_string was not malloced! */
7049 free_pipe_list(funcp->body);
7051 free(funcp->body_as_string);
7055 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7056 cmd->argv[0] = funcp->name;
7057 cmd->group = funcp->body;
7059 cmd->group_as_string = funcp->body_as_string;
7063 debug_printf_exec("remembering new function '%s'\n", name);
7064 funcp = *funcpp = xzalloc(sizeof(*funcp));
7065 /*funcp->next = NULL;*/
7072 # if ENABLE_HUSH_UNSET
7073 static void unset_func(const char *name)
7075 struct function **funcpp = find_function_slot(name);
7076 struct function *funcp = *funcpp;
7078 if (funcp != NULL) {
7079 debug_printf_exec("freeing function '%s'\n", funcp->name);
7080 *funcpp = funcp->next;
7081 /* funcp is unlinked now, deleting it.
7082 * Note: if !funcp->body, the function was created by
7083 * "-F name body", do not free ->body_as_string
7084 * and ->name as they were not malloced. */
7086 free_pipe_list(funcp->body);
7089 free(funcp->body_as_string);
7098 #define exec_function(to_free, funcp, argv) \
7099 exec_function(funcp, argv)
7101 static void exec_function(char ***to_free,
7102 const struct function *funcp,
7103 char **argv) NORETURN;
7104 static void exec_function(char ***to_free,
7105 const struct function *funcp,
7111 argv[0] = G.global_argv[0];
7112 G.global_argv = argv;
7113 G.global_argc = n = 1 + string_array_len(argv + 1);
7115 // Example when we are here: "cmd | func"
7116 // func will run with saved-redirect fds open.
7117 // $ f() { echo /proc/self/fd/*; }
7119 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7120 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7123 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7124 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7125 // They are CLOEXEC so external programs won't see them, but
7126 // for "more correctness" we might want to close those extra fds here:
7127 //? close_saved_fds_and_FILE_fds();
7129 /* "we are in function, ok to use return" */
7130 G_flag_return_in_progress = -1;
7131 IF_HUSH_LOCAL(G.func_nest_level++;)
7133 /* On MMU, funcp->body is always non-NULL */
7134 n = run_list(funcp->body);
7138 //? close_saved_fds_and_FILE_fds();
7140 //TODO: check whether "true | func_with_return" works
7142 re_execute_shell(to_free,
7143 funcp->body_as_string,
7150 static int run_function(const struct function *funcp, char **argv)
7156 save_and_replace_G_args(&sv, argv);
7158 /* "we are in function, ok to use return" */
7159 sv_flg = G_flag_return_in_progress;
7160 G_flag_return_in_progress = -1;
7161 IF_HUSH_LOCAL(G.func_nest_level++;)
7163 /* On MMU, funcp->body is always non-NULL */
7166 /* Function defined by -F */
7167 parse_and_run_string(funcp->body_as_string);
7168 rc = G.last_exitcode;
7172 rc = run_list(funcp->body);
7175 # if ENABLE_HUSH_LOCAL
7177 struct variable *var;
7178 struct variable **var_pp;
7180 var_pp = &G.top_var;
7181 while ((var = *var_pp) != NULL) {
7182 if (var->func_nest_level < G.func_nest_level) {
7183 var_pp = &var->next;
7187 if (var->flg_export)
7188 bb_unsetenv(var->varstr);
7189 /* Remove from global list */
7190 *var_pp = var->next;
7196 G.func_nest_level--;
7199 G_flag_return_in_progress = sv_flg;
7201 restore_G_args(&sv, argv);
7205 #endif /* ENABLE_HUSH_FUNCTIONS */
7209 #define exec_builtin(to_free, x, argv) \
7210 exec_builtin(x, argv)
7212 #define exec_builtin(to_free, x, argv) \
7213 exec_builtin(to_free, argv)
7215 static void exec_builtin(char ***to_free,
7216 const struct built_in_command *x,
7217 char **argv) NORETURN;
7218 static void exec_builtin(char ***to_free,
7219 const struct built_in_command *x,
7225 //? close_saved_fds_and_FILE_fds();
7226 rcode = x->b_function(argv);
7231 /* On NOMMU, we must never block!
7232 * Example: { sleep 99 | read line; } & echo Ok
7234 re_execute_shell(to_free,
7243 static void execvp_or_die(char **argv) NORETURN;
7244 static void execvp_or_die(char **argv)
7247 debug_printf_exec("execing '%s'\n", argv[0]);
7248 /* Don't propagate SIG_IGN to the child */
7249 if (SPECIAL_JOBSTOP_SIGS != 0)
7250 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7251 execvp(argv[0], argv);
7253 if (errno == EACCES) e = 126;
7254 if (errno == ENOENT) e = 127;
7255 bb_perror_msg("can't execute '%s'", argv[0]);
7259 #if ENABLE_HUSH_MODE_X
7260 static void dump_cmd_in_x_mode(char **argv)
7262 if (G_x_mode && argv) {
7263 /* We want to output the line in one write op */
7271 len += strlen(argv[n++]) + 1;
7277 p += sprintf(p, " %s", argv[n++]);
7285 # define dump_cmd_in_x_mode(argv) ((void)0)
7289 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7290 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7291 #define pseudo_exec(nommu_save, command, argv_expanded) \
7292 pseudo_exec(command, argv_expanded)
7295 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7297 * Don't exit() here. If you don't exec, use _exit instead.
7298 * The at_exit handlers apparently confuse the calling process,
7299 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7301 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7302 char **argv, int assignment_cnt,
7303 char **argv_expanded) NORETURN;
7304 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7305 char **argv, int assignment_cnt,
7306 char **argv_expanded)
7310 new_env = expand_assignments(argv, assignment_cnt);
7311 dump_cmd_in_x_mode(new_env);
7313 if (!argv[assignment_cnt]) {
7314 /* Case when we are here: ... | var=val | ...
7315 * (note that we do not exit early, i.e., do not optimize out
7316 * expand_assignments(): think about ... | var=`sleep 1` | ...
7318 free_strings(new_env);
7319 _exit(EXIT_SUCCESS);
7323 set_vars_and_save_old(new_env);
7324 free(new_env); /* optional */
7325 /* we can also destroy set_vars_and_save_old's return value,
7328 nommu_save->new_env = new_env;
7329 nommu_save->old_vars = set_vars_and_save_old(new_env);
7332 if (argv_expanded) {
7333 argv = argv_expanded;
7335 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7337 nommu_save->argv = argv;
7340 dump_cmd_in_x_mode(argv);
7342 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7343 if (strchr(argv[0], '/') != NULL)
7347 #if ENABLE_HUSH_FUNCTIONS
7348 /* Check if the command matches any functions (this goes before bltins) */
7350 const struct function *funcp = find_function(argv[0]);
7352 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7357 /* Check if the command matches any of the builtins.
7358 * Depending on context, this might be redundant. But it's
7359 * easier to waste a few CPU cycles than it is to figure out
7360 * if this is one of those cases.
7363 /* On NOMMU, it is more expensive to re-execute shell
7364 * just in order to run echo or test builtin.
7365 * It's better to skip it here and run corresponding
7366 * non-builtin later. */
7367 const struct built_in_command *x;
7368 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7370 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7374 #if ENABLE_FEATURE_SH_STANDALONE
7375 /* Check if the command matches any busybox applets */
7377 int a = find_applet_by_name(argv[0]);
7379 # if BB_MMU /* see above why on NOMMU it is not allowed */
7380 if (APPLET_IS_NOEXEC(a)) {
7381 /* Do not leak open fds from opened script files etc.
7382 * Testcase: interactive "ls -l /proc/self/fd"
7383 * should not show tty fd open.
7385 close_saved_fds_and_FILE_fds();
7386 //FIXME: should also close saved redir fds
7387 /* Without this, "rm -i FILE" can't be ^C'ed: */
7388 switch_off_special_sigs(G.special_sig_mask);
7389 debug_printf_exec("running applet '%s'\n", argv[0]);
7390 run_noexec_applet_and_exit(a, argv[0], argv);
7393 /* Re-exec ourselves */
7394 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7395 /* Don't propagate SIG_IGN to the child */
7396 if (SPECIAL_JOBSTOP_SIGS != 0)
7397 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7398 execv(bb_busybox_exec_path, argv);
7399 /* If they called chroot or otherwise made the binary no longer
7400 * executable, fall through */
7405 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7408 execvp_or_die(argv);
7411 /* Called after [v]fork() in run_pipe
7413 static void pseudo_exec(nommu_save_t *nommu_save,
7414 struct command *command,
7415 char **argv_expanded) NORETURN;
7416 static void pseudo_exec(nommu_save_t *nommu_save,
7417 struct command *command,
7418 char **argv_expanded)
7420 if (command->argv) {
7421 pseudo_exec_argv(nommu_save, command->argv,
7422 command->assignment_cnt, argv_expanded);
7425 if (command->group) {
7426 /* Cases when we are here:
7429 * ... | ( list ) | ...
7430 * ... | { list } | ...
7434 debug_printf_exec("pseudo_exec: run_list\n");
7435 reset_traps_to_defaults();
7436 rcode = run_list(command->group);
7437 /* OK to leak memory by not calling free_pipe_list,
7438 * since this process is about to exit */
7441 re_execute_shell(&nommu_save->argv_from_re_execing,
7442 command->group_as_string,
7449 /* Case when we are here: ... | >file */
7450 debug_printf_exec("pseudo_exec'ed null command\n");
7451 _exit(EXIT_SUCCESS);
7455 static const char *get_cmdtext(struct pipe *pi)
7461 /* This is subtle. ->cmdtext is created only on first backgrounding.
7462 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7463 * On subsequent bg argv is trashed, but we won't use it */
7467 argv = pi->cmds[0].argv;
7469 pi->cmdtext = xzalloc(1);
7474 len += strlen(*argv) + 1;
7478 argv = pi->cmds[0].argv;
7480 p = stpcpy(p, *argv);
7487 static void remove_job_from_table(struct pipe *pi)
7489 struct pipe *prev_pipe;
7491 if (pi == G.job_list) {
7492 G.job_list = pi->next;
7494 prev_pipe = G.job_list;
7495 while (prev_pipe->next != pi)
7496 prev_pipe = prev_pipe->next;
7497 prev_pipe->next = pi->next;
7501 G.last_jobid = G.job_list->jobid;
7504 static void delete_finished_job(struct pipe *pi)
7506 remove_job_from_table(pi);
7510 static void clean_up_last_dead_job(void)
7512 if (G.job_list && !G.job_list->alive_cmds)
7513 delete_finished_job(G.job_list);
7516 static void insert_job_into_table(struct pipe *pi)
7518 struct pipe *job, **jobp;
7521 clean_up_last_dead_job();
7523 /* Find the end of the list, and find next job ID to use */
7526 while ((job = *jobp) != NULL) {
7533 /* Create a new job struct at the end */
7534 job = *jobp = xmemdup(pi, sizeof(*pi));
7536 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7537 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7538 for (i = 0; i < pi->num_cmds; i++) {
7539 job->cmds[i].pid = pi->cmds[i].pid;
7540 /* all other fields are not used and stay zero */
7542 job->cmdtext = xstrdup(get_cmdtext(pi));
7544 if (G_interactive_fd)
7545 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7546 G.last_jobid = job->jobid;
7550 static int job_exited_or_stopped(struct pipe *pi)
7554 if (pi->alive_cmds != pi->stopped_cmds)
7557 /* All processes in fg pipe have exited or stopped */
7561 rcode = pi->cmds[i].cmd_exitcode;
7562 /* usually last process gives overall exitstatus,
7563 * but with "set -o pipefail", last *failed* process does */
7564 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7567 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7571 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7578 dead = WIFEXITED(status) || WIFSIGNALED(status);
7581 if (WIFSTOPPED(status))
7582 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7583 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7584 if (WIFSIGNALED(status))
7585 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7586 childpid, WTERMSIG(status), WEXITSTATUS(status));
7587 if (WIFEXITED(status))
7588 debug_printf_jobs("pid %d exited, exitcode %d\n",
7589 childpid, WEXITSTATUS(status));
7591 /* Were we asked to wait for a fg pipe? */
7593 i = fg_pipe->num_cmds;
7598 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7599 if (fg_pipe->cmds[i].pid != childpid)
7603 fg_pipe->cmds[i].pid = 0;
7604 fg_pipe->alive_cmds--;
7605 ex = WEXITSTATUS(status);
7606 /* bash prints killer signal's name for *last*
7607 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7608 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7610 if (WIFSIGNALED(status)) {
7611 int sig = WTERMSIG(status);
7612 if (i == fg_pipe->num_cmds-1)
7613 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7614 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7615 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7616 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7617 * Maybe we need to use sig | 128? */
7620 fg_pipe->cmds[i].cmd_exitcode = ex;
7622 fg_pipe->stopped_cmds++;
7624 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7625 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7626 rcode = job_exited_or_stopped(fg_pipe);
7628 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7629 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7630 * and "killall -STOP cat" */
7631 if (G_interactive_fd) {
7633 if (fg_pipe->alive_cmds != 0)
7634 insert_job_into_table(fg_pipe);
7638 if (fg_pipe->alive_cmds == 0)
7641 /* There are still running processes in the fg_pipe */
7644 /* It wasn't in fg_pipe, look for process in bg pipes */
7648 /* We were asked to wait for bg or orphaned children */
7649 /* No need to remember exitcode in this case */
7650 for (pi = G.job_list; pi; pi = pi->next) {
7651 for (i = 0; i < pi->num_cmds; i++) {
7652 if (pi->cmds[i].pid == childpid)
7653 goto found_pi_and_prognum;
7656 /* Happens when shell is used as init process (init=/bin/sh) */
7657 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7658 return -1; /* this wasn't a process from fg_pipe */
7660 found_pi_and_prognum:
7663 int rcode = WEXITSTATUS(status);
7664 if (WIFSIGNALED(status))
7665 rcode = 128 + WTERMSIG(status);
7666 pi->cmds[i].cmd_exitcode = rcode;
7667 if (G.last_bg_pid == pi->cmds[i].pid)
7668 G.last_bg_pid_exitcode = rcode;
7669 pi->cmds[i].pid = 0;
7671 if (!pi->alive_cmds) {
7672 if (G_interactive_fd) {
7673 printf(JOB_STATUS_FORMAT, pi->jobid,
7674 "Done", pi->cmdtext);
7675 delete_finished_job(pi);
7678 * bash deletes finished jobs from job table only in interactive mode,
7679 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7680 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7681 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7682 * We only retain one "dead" job, if it's the single job on the list.
7683 * This covers most of real-world scenarios where this is useful.
7685 if (pi != G.job_list)
7686 delete_finished_job(pi);
7694 return -1; /* this wasn't a process from fg_pipe */
7697 /* Check to see if any processes have exited -- if they have,
7698 * figure out why and see if a job has completed.
7700 * If non-NULL fg_pipe: wait for its completion or stop.
7701 * Return its exitcode or zero if stopped.
7703 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7704 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7705 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7706 * or 0 if no children changed status.
7708 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7709 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7710 * or 0 if no children changed status.
7712 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7718 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7720 attributes = WUNTRACED;
7721 if (fg_pipe == NULL)
7722 attributes |= WNOHANG;
7725 #if ENABLE_HUSH_FAST
7726 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7727 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7728 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7729 /* There was neither fork nor SIGCHLD since last waitpid */
7730 /* Avoid doing waitpid syscall if possible */
7731 if (!G.we_have_children) {
7735 if (fg_pipe == NULL) { /* is WNOHANG set? */
7736 /* We have children, but they did not exit
7737 * or stop yet (we saw no SIGCHLD) */
7740 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7744 /* Do we do this right?
7745 * bash-3.00# sleep 20 | false
7747 * [3]+ Stopped sleep 20 | false
7748 * bash-3.00# echo $?
7749 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7750 * [hush 1.14.0: yes we do it right]
7754 #if ENABLE_HUSH_FAST
7756 i = G.count_SIGCHLD;
7758 childpid = waitpid(-1, &status, attributes);
7759 if (childpid <= 0) {
7760 if (childpid && errno != ECHILD)
7761 bb_perror_msg("waitpid");
7762 #if ENABLE_HUSH_FAST
7763 else { /* Until next SIGCHLD, waitpid's are useless */
7764 G.we_have_children = (childpid == 0);
7765 G.handled_SIGCHLD = i;
7766 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7769 /* ECHILD (no children), or 0 (no change in children status) */
7773 rcode = process_wait_result(fg_pipe, childpid, status);
7775 /* fg_pipe exited or stopped */
7778 if (childpid == waitfor_pid) {
7779 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7780 rcode = WEXITSTATUS(status);
7781 if (WIFSIGNALED(status))
7782 rcode = 128 + WTERMSIG(status);
7783 if (WIFSTOPPED(status))
7784 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7785 rcode = 128 + WSTOPSIG(status);
7787 break; /* "wait PID" called us, give it exitcode+1 */
7789 /* This wasn't one of our processes, or */
7790 /* fg_pipe still has running processes, do waitpid again */
7791 } /* while (waitpid succeeds)... */
7797 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7800 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7801 if (G_saved_tty_pgrp) {
7802 /* Job finished, move the shell to the foreground */
7803 p = getpgrp(); /* our process group id */
7804 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7805 tcsetpgrp(G_interactive_fd, p);
7811 /* Start all the jobs, but don't wait for anything to finish.
7814 * Return code is normally -1, when the caller has to wait for children
7815 * to finish to determine the exit status of the pipe. If the pipe
7816 * is a simple builtin command, however, the action is done by the
7817 * time run_pipe returns, and the exit code is provided as the
7820 * Returns -1 only if started some children. IOW: we have to
7821 * mask out retvals of builtins etc with 0xff!
7823 * The only case when we do not need to [v]fork is when the pipe
7824 * is single, non-backgrounded, non-subshell command. Examples:
7825 * cmd ; ... { list } ; ...
7826 * cmd && ... { list } && ...
7827 * cmd || ... { list } || ...
7828 * If it is, then we can run cmd as a builtin, NOFORK,
7829 * or (if SH_STANDALONE) an applet, and we can run the { list }
7830 * with run_list. If it isn't one of these, we fork and exec cmd.
7832 * Cases when we must fork:
7833 * non-single: cmd | cmd
7834 * backgrounded: cmd & { list } &
7835 * subshell: ( list ) [&]
7837 #if !ENABLE_HUSH_MODE_X
7838 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7839 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7841 static int redirect_and_varexp_helper(char ***new_env_p,
7842 struct variable **old_vars_p,
7843 struct command *command,
7844 struct squirrel **sqp,
7845 char **argv_expanded)
7847 /* setup_redirects acts on file descriptors, not FILEs.
7848 * This is perfect for work that comes after exec().
7849 * Is it really safe for inline use? Experimentally,
7850 * things seem to work. */
7851 int rcode = setup_redirects(command, sqp);
7853 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7854 *new_env_p = new_env;
7855 dump_cmd_in_x_mode(new_env);
7856 dump_cmd_in_x_mode(argv_expanded);
7858 *old_vars_p = set_vars_and_save_old(new_env);
7862 static NOINLINE int run_pipe(struct pipe *pi)
7864 static const char *const null_ptr = NULL;
7868 struct command *command;
7869 char **argv_expanded;
7871 struct squirrel *squirrel = NULL;
7874 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7877 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7878 * Result should be 3 lines: q w e, qwe, q w e
7880 G.ifs = get_local_var_value("IFS");
7884 IF_HUSH_JOB(pi->pgrp = -1;)
7885 pi->stopped_cmds = 0;
7886 command = &pi->cmds[0];
7887 argv_expanded = NULL;
7889 if (pi->num_cmds != 1
7890 || pi->followup == PIPE_BG
7891 || command->cmd_type == CMD_SUBSHELL
7898 debug_printf_exec(": group:%p argv:'%s'\n",
7899 command->group, command->argv ? command->argv[0] : "NONE");
7901 if (command->group) {
7902 #if ENABLE_HUSH_FUNCTIONS
7903 if (command->cmd_type == CMD_FUNCDEF) {
7904 /* "executing" func () { list } */
7905 struct function *funcp;
7907 funcp = new_function(command->argv[0]);
7908 /* funcp->name is already set to argv[0] */
7909 funcp->body = command->group;
7911 funcp->body_as_string = command->group_as_string;
7912 command->group_as_string = NULL;
7914 command->group = NULL;
7915 command->argv[0] = NULL;
7916 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7917 funcp->parent_cmd = command;
7918 command->child_func = funcp;
7920 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7922 return EXIT_SUCCESS;
7926 debug_printf("non-subshell group\n");
7927 rcode = 1; /* exitcode if redir failed */
7928 if (setup_redirects(command, &squirrel) == 0) {
7929 debug_printf_exec(": run_list\n");
7930 rcode = run_list(command->group) & 0xff;
7932 restore_redirects(squirrel);
7933 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7935 debug_printf_exec("run_pipe: return %d\n", rcode);
7939 argv = command->argv ? command->argv : (char **) &null_ptr;
7941 const struct built_in_command *x;
7942 #if ENABLE_HUSH_FUNCTIONS
7943 const struct function *funcp;
7947 char **new_env = NULL;
7948 struct variable *old_vars = NULL;
7950 if (argv[command->assignment_cnt] == NULL) {
7951 /* Assignments, but no command */
7952 /* Ensure redirects take effect (that is, create files).
7953 * Try "a=t >file" */
7954 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7955 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7956 /* Set shell variables */
7960 if (set_local_var(*argv, /*flag:*/ 0)) {
7961 /* assignment to readonly var / putenv error? */
7967 /* Redirect error sets $? to 1. Otherwise,
7968 * if evaluating assignment value set $?, retain it.
7969 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7971 rcode = G.last_exitcode;
7972 /* Exit, _skipping_ variable restoring code: */
7973 goto clean_up_and_ret0;
7975 #else /* Older, bigger, but more correct code */
7977 rcode = setup_redirects(command, &squirrel);
7978 restore_redirects(squirrel);
7979 /* Set shell variables */
7981 bb_putchar_stderr('+');
7983 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7985 fprintf(stderr, " %s", p);
7986 debug_printf_exec("set shell var:'%s'->'%s'\n",
7988 if (set_local_var(p, /*flag:*/ 0)) {
7989 /* assignment to readonly var / putenv error? */
7995 bb_putchar_stderr('\n');
7996 /* Redirect error sets $? to 1. Otherwise,
7997 * if evaluating assignment value set $?, retain it.
7998 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8000 rcode = G.last_exitcode;
8001 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8003 debug_printf_exec("run_pipe: return %d\n", rcode);
8008 /* Expand the rest into (possibly) many strings each */
8010 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8011 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8015 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8018 /* if someone gives us an empty string: `cmd with empty output` */
8019 if (!argv_expanded[0]) {
8020 free(argv_expanded);
8022 return G.last_exitcode;
8025 #if ENABLE_HUSH_FUNCTIONS
8026 /* Check if argv[0] matches any functions (this goes before bltins) */
8027 funcp = find_function(argv_expanded[0]);
8031 x = find_builtin(argv_expanded[0]);
8034 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8035 debug_printf("exec with redirects only\n");
8036 rcode = setup_redirects(command, NULL);
8037 /* rcode=1 can be if redir file can't be opened */
8038 goto clean_up_and_ret1;
8041 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8044 debug_printf_exec(": builtin '%s' '%s'...\n",
8045 x->b_cmd, argv_expanded[1]);
8047 rcode = x->b_function(argv_expanded) & 0xff;
8050 #if ENABLE_HUSH_FUNCTIONS
8052 # if ENABLE_HUSH_LOCAL
8053 struct variable **sv;
8054 sv = G.shadowed_vars_pp;
8055 G.shadowed_vars_pp = &old_vars;
8057 debug_printf_exec(": function '%s' '%s'...\n",
8058 funcp->name, argv_expanded[1]);
8059 rcode = run_function(funcp, argv_expanded) & 0xff;
8060 # if ENABLE_HUSH_LOCAL
8061 G.shadowed_vars_pp = sv;
8067 unset_vars(new_env);
8069 /* clean_up_and_ret0: */
8070 restore_redirects(squirrel);
8072 * Try "usleep 99999999" + ^C + "echo $?"
8073 * with FEATURE_SH_NOFORK=y.
8076 /* It was builtin or nofork.
8077 * if this would be a real fork/execed program,
8078 * it should have died if a fatal sig was received.
8079 * But OTOH, there was no separate process,
8080 * the sig was sent to _shell_, not to non-existing
8082 * Let's just handle ^C only, this one is obvious:
8083 * we aren't ok with exitcode 0 when ^C was pressed
8084 * during builtin/nofork.
8086 if (sigismember(&G.pending_set, SIGINT))
8087 rcode = 128 + SIGINT;
8090 free(argv_expanded);
8091 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8093 debug_printf_exec("run_pipe return %d\n", rcode);
8097 if (ENABLE_FEATURE_SH_NOFORK) {
8098 int n = find_applet_by_name(argv_expanded[0]);
8099 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8100 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8102 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8103 argv_expanded[0], argv_expanded[1]);
8105 * Note: signals (^C) can't interrupt here.
8106 * We remember them and they will be acted upon
8107 * after applet returns.
8108 * This makes applets which can run for a long time
8109 * and/or wait for user input ineligible for NOFORK:
8110 * for example, "yes" or "rm" (rm -i waits for input).
8112 rcode = run_nofork_applet(n, argv_expanded);
8114 goto clean_up_and_ret;
8117 /* It is neither builtin nor applet. We must fork. */
8121 /* NB: argv_expanded may already be created, and that
8122 * might include `cmd` runs! Do not rerun it! We *must*
8123 * use argv_expanded if it's non-NULL */
8125 /* Going to fork a child per each pipe member */
8130 while (cmd_no < pi->num_cmds) {
8131 struct fd_pair pipefds;
8133 volatile nommu_save_t nommu_save;
8134 nommu_save.new_env = NULL;
8135 nommu_save.old_vars = NULL;
8136 nommu_save.argv = NULL;
8137 nommu_save.argv_from_re_execing = NULL;
8139 command = &pi->cmds[cmd_no];
8141 if (command->argv) {
8142 debug_printf_exec(": pipe member '%s' '%s'...\n",
8143 command->argv[0], command->argv[1]);
8145 debug_printf_exec(": pipe member with no argv\n");
8148 /* pipes are inserted between pairs of commands */
8151 if (cmd_no < pi->num_cmds)
8152 xpiped_pair(pipefds);
8154 command->pid = BB_MMU ? fork() : vfork();
8155 if (!command->pid) { /* child */
8157 disable_restore_tty_pgrp_on_exit();
8158 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8160 /* Every child adds itself to new process group
8161 * with pgid == pid_of_first_child_in_pipe */
8162 if (G.run_list_level == 1 && G_interactive_fd) {
8165 if (pgrp < 0) /* true for 1st process only */
8167 if (setpgid(0, pgrp) == 0
8168 && pi->followup != PIPE_BG
8169 && G_saved_tty_pgrp /* we have ctty */
8171 /* We do it in *every* child, not just first,
8173 tcsetpgrp(G_interactive_fd, pgrp);
8177 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8178 /* 1st cmd in backgrounded pipe
8179 * should have its stdin /dev/null'ed */
8181 if (open(bb_dev_null, O_RDONLY))
8182 xopen("/", O_RDONLY);
8184 xmove_fd(next_infd, 0);
8186 xmove_fd(pipefds.wr, 1);
8189 /* Like bash, explicit redirects override pipes,
8190 * and the pipe fd (fd#1) is available for dup'ing:
8191 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8192 * of cmd1 goes into pipe.
8194 if (setup_redirects(command, NULL)) {
8195 /* Happens when redir file can't be opened:
8196 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8198 * hush: can't open '/qwe/rty': No such file or directory
8200 * (echo BAR is not executed, it hits _exit(1) below)
8205 /* Stores to nommu_save list of env vars putenv'ed
8206 * (NOMMU, on MMU we don't need that) */
8207 /* cast away volatility... */
8208 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8209 /* pseudo_exec() does not return */
8212 /* parent or error */
8213 #if ENABLE_HUSH_FAST
8215 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8217 enable_restore_tty_pgrp_on_exit();
8219 /* Clean up after vforked child */
8220 free(nommu_save.argv);
8221 free(nommu_save.argv_from_re_execing);
8222 unset_vars(nommu_save.new_env);
8223 add_vars(nommu_save.old_vars);
8225 free(argv_expanded);
8226 argv_expanded = NULL;
8227 if (command->pid < 0) { /* [v]fork failed */
8228 /* Clearly indicate, was it fork or vfork */
8229 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8233 /* Second and next children need to know pid of first one */
8235 pi->pgrp = command->pid;
8241 if (cmd_no < pi->num_cmds)
8243 /* Pass read (output) pipe end to next iteration */
8244 next_infd = pipefds.rd;
8247 if (!pi->alive_cmds) {
8249 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8254 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8258 /* NB: called by pseudo_exec, and therefore must not modify any
8259 * global data until exec/_exit (we can be a child after vfork!) */
8260 static int run_list(struct pipe *pi)
8262 #if ENABLE_HUSH_CASE
8263 char *case_word = NULL;
8265 #if ENABLE_HUSH_LOOPS
8266 struct pipe *loop_top = NULL;
8267 char **for_lcur = NULL;
8268 char **for_list = NULL;
8270 smallint last_followup;
8272 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8273 smalluint cond_code = 0;
8275 enum { cond_code = 0 };
8278 smallint rword; /* RES_foo */
8279 smallint last_rword; /* ditto */
8282 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8285 #if ENABLE_HUSH_LOOPS
8286 /* Check syntax for "for" */
8289 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8290 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8292 /* current word is FOR or IN (BOLD in comments below) */
8293 if (cpipe->next == NULL) {
8294 syntax_error("malformed for");
8296 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8299 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8300 if (cpipe->next->res_word == RES_DO)
8302 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8303 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8304 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8306 syntax_error("malformed for");
8308 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8315 /* Past this point, all code paths should jump to ret: label
8316 * in order to return, no direct "return" statements please.
8317 * This helps to ensure that no memory is leaked. */
8325 last_rword = RES_XXXX;
8327 last_followup = PIPE_SEQ;
8328 rcode = G.last_exitcode;
8330 /* Go through list of pipes, (maybe) executing them. */
8331 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8333 int sv_errexit_depth;
8337 if (G_flag_return_in_progress == 1)
8340 IF_HAS_KEYWORDS(rword = pi->res_word;)
8341 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8342 rword, cond_code, last_rword);
8344 sv_errexit_depth = G.errexit_depth;
8345 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8346 pi->followup != PIPE_SEQ
8350 #if ENABLE_HUSH_LOOPS
8351 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8352 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8354 /* start of a loop: remember where loop starts */
8359 /* Still in the same "if...", "then..." or "do..." branch? */
8360 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8361 if ((rcode == 0 && last_followup == PIPE_OR)
8362 || (rcode != 0 && last_followup == PIPE_AND)
8364 /* It is "<true> || CMD" or "<false> && CMD"
8365 * and we should not execute CMD */
8366 debug_printf_exec("skipped cmd because of || or &&\n");
8367 last_followup = pi->followup;
8368 goto dont_check_jobs_but_continue;
8371 last_followup = pi->followup;
8372 IF_HAS_KEYWORDS(last_rword = rword;)
8375 if (rword == RES_THEN) {
8376 /* if false; then ... fi has exitcode 0! */
8377 G.last_exitcode = rcode = EXIT_SUCCESS;
8378 /* "if <false> THEN cmd": skip cmd */
8382 if (rword == RES_ELSE || rword == RES_ELIF) {
8383 /* "if <true> then ... ELSE/ELIF cmd":
8384 * skip cmd and all following ones */
8389 #if ENABLE_HUSH_LOOPS
8390 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8392 /* first loop through for */
8394 static const char encoded_dollar_at[] ALIGN1 = {
8395 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8396 }; /* encoded representation of "$@" */
8397 static const char *const encoded_dollar_at_argv[] = {
8398 encoded_dollar_at, NULL
8399 }; /* argv list with one element: "$@" */
8402 vals = (char**)encoded_dollar_at_argv;
8403 if (pi->next->res_word == RES_IN) {
8404 /* if no variable values after "in" we skip "for" */
8405 if (!pi->next->cmds[0].argv) {
8406 G.last_exitcode = rcode = EXIT_SUCCESS;
8407 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8410 vals = pi->next->cmds[0].argv;
8411 } /* else: "for var; do..." -> assume "$@" list */
8412 /* create list of variable values */
8413 debug_print_strings("for_list made from", vals);
8414 for_list = expand_strvec_to_strvec(vals);
8415 for_lcur = for_list;
8416 debug_print_strings("for_list", for_list);
8419 /* "for" loop is over, clean up */
8425 /* Insert next value from for_lcur */
8426 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8427 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8430 if (rword == RES_IN) {
8431 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8433 if (rword == RES_DONE) {
8434 continue; /* "done" has no cmds too */
8437 #if ENABLE_HUSH_CASE
8438 if (rword == RES_CASE) {
8439 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8440 case_word = expand_strvec_to_string(pi->cmds->argv);
8441 unbackslash(case_word);
8444 if (rword == RES_MATCH) {
8447 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8448 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8450 /* all prev words didn't match, does this one match? */
8451 argv = pi->cmds->argv;
8453 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8454 /* TODO: which FNM_xxx flags to use? */
8455 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8456 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8458 if (cond_code == 0) { /* match! we will execute this branch */
8460 case_word = NULL; /* make future "word)" stop */
8467 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8468 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8470 continue; /* not matched yet, skip this pipe */
8472 if (rword == RES_ESAC) {
8473 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8475 /* "case" did not match anything: still set $? (to 0) */
8476 G.last_exitcode = rcode = EXIT_SUCCESS;
8480 /* Just pressing <enter> in shell should check for jobs.
8481 * OTOH, in non-interactive shell this is useless
8482 * and only leads to extra job checks */
8483 if (pi->num_cmds == 0) {
8484 if (G_interactive_fd)
8485 goto check_jobs_and_continue;
8489 /* After analyzing all keywords and conditions, we decided
8490 * to execute this pipe. NB: have to do checkjobs(NULL)
8491 * after run_pipe to collect any background children,
8492 * even if list execution is to be stopped. */
8493 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8494 #if ENABLE_HUSH_LOOPS
8495 G.flag_break_continue = 0;
8497 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8499 /* We ran a builtin, function, or group.
8500 * rcode is already known
8501 * and we don't need to wait for anything. */
8502 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8503 G.last_exitcode = rcode;
8504 check_and_run_traps();
8505 #if ENABLE_HUSH_LOOPS
8506 /* Was it "break" or "continue"? */
8507 if (G.flag_break_continue) {
8508 smallint fbc = G.flag_break_continue;
8509 /* We might fall into outer *loop*,
8510 * don't want to break it too */
8512 G.depth_break_continue--;
8513 if (G.depth_break_continue == 0)
8514 G.flag_break_continue = 0;
8515 /* else: e.g. "continue 2" should *break* once, *then* continue */
8516 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8517 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8518 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8521 /* "continue": simulate end of loop */
8526 if (G_flag_return_in_progress == 1) {
8527 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8530 } else if (pi->followup == PIPE_BG) {
8531 /* What does bash do with attempts to background builtins? */
8532 /* even bash 3.2 doesn't do that well with nested bg:
8533 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8534 * I'm NOT treating inner &'s as jobs */
8536 if (G.run_list_level == 1)
8537 insert_job_into_table(pi);
8539 /* Last command's pid goes to $! */
8540 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8541 G.last_bg_pid_exitcode = 0;
8542 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8543 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8544 rcode = EXIT_SUCCESS;
8548 if (G.run_list_level == 1 && G_interactive_fd) {
8549 /* Waits for completion, then fg's main shell */
8550 rcode = checkjobs_and_fg_shell(pi);
8551 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8555 /* This one just waits for completion */
8556 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8557 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8559 G.last_exitcode = rcode;
8560 check_and_run_traps();
8563 /* Handle "set -e" */
8564 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8565 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8566 if (G.errexit_depth == 0)
8569 G.errexit_depth = sv_errexit_depth;
8571 /* Analyze how result affects subsequent commands */
8573 if (rword == RES_IF || rword == RES_ELIF)
8576 check_jobs_and_continue:
8577 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8578 dont_check_jobs_but_continue: ;
8579 #if ENABLE_HUSH_LOOPS
8580 /* Beware of "while false; true; do ..."! */
8582 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8583 /* check for RES_DONE is needed for "while ...; do \n done" case */
8585 if (rword == RES_WHILE) {
8587 /* "while false; do...done" - exitcode 0 */
8588 G.last_exitcode = rcode = EXIT_SUCCESS;
8589 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8593 if (rword == RES_UNTIL) {
8595 debug_printf_exec(": until expr is true: breaking\n");
8606 #if ENABLE_HUSH_LOOPS
8611 #if ENABLE_HUSH_CASE
8615 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8619 /* Select which version we will use */
8620 static int run_and_free_list(struct pipe *pi)
8623 debug_printf_exec("run_and_free_list entered\n");
8624 if (!G.o_opt[OPT_O_NOEXEC]) {
8625 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8626 rcode = run_list(pi);
8628 /* free_pipe_list has the side effect of clearing memory.
8629 * In the long run that function can be merged with run_list,
8630 * but doing that now would hobble the debugging effort. */
8632 debug_printf_exec("run_and_free_list return %d\n", rcode);
8637 static void install_sighandlers(unsigned mask)
8639 sighandler_t old_handler;
8641 while ((mask >>= 1) != 0) {
8645 old_handler = install_sighandler(sig, pick_sighandler(sig));
8646 /* POSIX allows shell to re-enable SIGCHLD
8647 * even if it was SIG_IGN on entry.
8648 * Therefore we skip IGN check for it:
8652 /* bash re-enables SIGHUP which is SIG_IGNed on entry.
8653 * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
8655 //if (sig == SIGHUP) continue; - TODO?
8656 if (old_handler == SIG_IGN) {
8657 /* oops... restore back to IGN, and record this fact */
8658 install_sighandler(sig, old_handler);
8659 #if ENABLE_HUSH_TRAP
8661 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8663 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8669 /* Called a few times only (or even once if "sh -c") */
8670 static void install_special_sighandlers(void)
8674 /* Which signals are shell-special? */
8675 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8676 if (G_interactive_fd) {
8677 mask |= SPECIAL_INTERACTIVE_SIGS;
8678 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8679 mask |= SPECIAL_JOBSTOP_SIGS;
8681 /* Careful, do not re-install handlers we already installed */
8682 if (G.special_sig_mask != mask) {
8683 unsigned diff = mask & ~G.special_sig_mask;
8684 G.special_sig_mask = mask;
8685 install_sighandlers(diff);
8691 /* Set handlers to restore tty pgrp and exit */
8692 static void install_fatal_sighandlers(void)
8696 /* We will restore tty pgrp on these signals */
8698 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8699 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8700 + (1 << SIGBUS ) * HUSH_DEBUG
8701 + (1 << SIGSEGV) * HUSH_DEBUG
8702 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8704 /* bash 3.2 seems to handle these just like 'fatal' ones */
8707 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8708 * if we aren't interactive... but in this case
8709 * we never want to restore pgrp on exit, and this fn is not called
8711 /*+ (1 << SIGHUP )*/
8712 /*+ (1 << SIGTERM)*/
8713 /*+ (1 << SIGINT )*/
8715 G_fatal_sig_mask = mask;
8717 install_sighandlers(mask);
8721 static int set_mode(int state, char mode, const char *o_opt)
8726 G.o_opt[OPT_O_NOEXEC] = state;
8729 IF_HUSH_MODE_X(G_x_mode = state;)
8733 /* "set -+o" without parameter.
8734 * in bash, set -o produces this output:
8738 * We always use the second form.
8740 const char *p = o_opt_strings;
8743 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8749 idx = index_in_strings(o_opt_strings, o_opt);
8751 G.o_opt[idx] = state;
8755 G.o_opt[OPT_O_ERREXIT] = state;
8758 return EXIT_FAILURE;
8760 return EXIT_SUCCESS;
8763 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8764 int hush_main(int argc, char **argv)
8767 OPT_login = (1 << 0),
8771 unsigned builtin_argc;
8773 struct variable *cur_var;
8774 struct variable *shell_ver;
8777 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8778 G.last_exitcode = EXIT_SUCCESS;
8780 #if ENABLE_HUSH_FAST
8781 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8784 G.argv0_for_re_execing = argv[0];
8786 /* Deal with HUSH_VERSION */
8787 shell_ver = xzalloc(sizeof(*shell_ver));
8788 shell_ver->flg_export = 1;
8789 shell_ver->flg_read_only = 1;
8790 /* Code which handles ${var<op>...} needs writable values for all variables,
8791 * therefore we xstrdup: */
8792 shell_ver->varstr = xstrdup(hush_version_str);
8793 /* Create shell local variables from the values
8794 * currently living in the environment */
8795 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8796 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8797 G.top_var = shell_ver;
8798 cur_var = G.top_var;
8801 char *value = strchr(*e, '=');
8802 if (value) { /* paranoia */
8803 cur_var->next = xzalloc(sizeof(*cur_var));
8804 cur_var = cur_var->next;
8805 cur_var->varstr = *e;
8806 cur_var->max_len = strlen(*e);
8807 cur_var->flg_export = 1;
8811 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8812 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8813 putenv(shell_ver->varstr);
8816 set_pwd_var(SETFLAG_EXPORT);
8818 #if BASH_HOSTNAME_VAR
8819 /* Set (but not export) HOSTNAME unless already set */
8820 if (!get_local_var_value("HOSTNAME")) {
8823 set_local_var_from_halves("HOSTNAME", uts.nodename);
8825 /* bash also exports SHLVL and _,
8826 * and sets (but doesn't export) the following variables:
8828 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8829 * BASH_VERSION='3.2.0(1)-release'
8831 * MACHTYPE=i386-pc-linux-gnu
8833 * PPID=<NNNNN> - we also do it elsewhere
8844 * PIPESTATUS=([0]="0")
8845 * HISTFILE=/<xxx>/.bash_history
8849 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8851 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8862 #if ENABLE_FEATURE_EDITING
8863 G.line_input_state = new_line_input_t(FOR_SHELL);
8866 /* Initialize some more globals to non-zero values */
8867 cmdedit_update_prompt();
8869 die_func = restore_ttypgrp_and__exit;
8871 /* Shell is non-interactive at first. We need to call
8872 * install_special_sighandlers() if we are going to execute "sh <script>",
8873 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8874 * If we later decide that we are interactive, we run install_special_sighandlers()
8875 * in order to intercept (more) signals.
8879 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8880 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8883 opt = getopt(argc, argv, "+c:exinsl"
8886 # if ENABLE_HUSH_FUNCTIONS
8896 * sh ... -c 'script'
8897 * sh ... -c 'script' ARG0 [ARG1...]
8898 * On NOMMU, if builtin_argc != 0,
8899 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8900 * "" needs to be replaced with NULL
8901 * and BARGV vector fed to builtin function.
8902 * Note: the form without ARG0 never happens:
8903 * sh ... -c 'builtin' BARGV... ""
8906 G.root_pid = getpid();
8907 G.root_ppid = getppid();
8909 G.global_argv = argv + optind;
8910 G.global_argc = argc - optind;
8912 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8913 const struct built_in_command *x;
8915 install_special_sighandlers();
8916 x = find_builtin(optarg);
8917 if (x) { /* paranoia */
8918 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8919 G.global_argv += builtin_argc;
8920 G.global_argv[-1] = NULL; /* replace "" */
8922 G.last_exitcode = x->b_function(argv + optind - 1);
8926 if (!G.global_argv[0]) {
8927 /* -c 'script' (no params): prevent empty $0 */
8928 G.global_argv--; /* points to argv[i] of 'script' */
8929 G.global_argv[0] = argv[0];
8931 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8932 install_special_sighandlers();
8933 parse_and_run_string(optarg);
8936 /* Well, we cannot just declare interactiveness,
8937 * we have to have some stuff (ctty, etc) */
8938 /* G_interactive_fd++; */
8941 /* "-s" means "read from stdin", but this is how we always
8942 * operate, so simply do nothing here. */
8948 case '<': /* "big heredoc" support */
8949 full_write1_str(optarg);
8952 unsigned long long empty_trap_mask;
8954 G.root_pid = bb_strtou(optarg, &optarg, 16);
8956 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8958 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8960 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8962 builtin_argc = bb_strtou(optarg, &optarg, 16);
8964 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8965 if (empty_trap_mask != 0) {
8966 IF_HUSH_TRAP(int sig;)
8967 install_special_sighandlers();
8968 # if ENABLE_HUSH_TRAP
8969 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8970 for (sig = 1; sig < NSIG; sig++) {
8971 if (empty_trap_mask & (1LL << sig)) {
8972 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8973 install_sighandler(sig, SIG_IGN);
8978 # if ENABLE_HUSH_LOOPS
8980 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8986 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8988 # if ENABLE_HUSH_FUNCTIONS
8990 struct function *funcp = new_function(optarg);
8991 /* funcp->name is already set to optarg */
8992 /* funcp->body is set to NULL. It's a special case. */
8993 funcp->body_as_string = argv[optind];
9002 if (set_mode(1, opt, NULL) == 0) /* no error */
9006 fprintf(stderr, "Usage: sh [FILE]...\n"
9007 " or: sh -c command [args]...\n\n");
9013 } /* option parsing loop */
9015 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9016 G.global_argc = argc - (optind - 1);
9017 G.global_argv = argv + (optind - 1);
9018 G.global_argv[0] = argv[0];
9021 G.root_pid = getpid();
9022 G.root_ppid = getppid();
9025 /* If we are login shell... */
9026 if (flags & OPT_login) {
9028 debug_printf("sourcing /etc/profile\n");
9029 input = fopen_for_read("/etc/profile");
9030 if (input != NULL) {
9031 remember_FILE(input);
9032 install_special_sighandlers();
9033 parse_and_run_file(input);
9034 fclose_and_forget(input);
9036 /* bash: after sourcing /etc/profile,
9037 * tries to source (in the given order):
9038 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9039 * stopping on first found. --noprofile turns this off.
9040 * bash also sources ~/.bash_logout on exit.
9041 * If called as sh, skips .bash_XXX files.
9045 if (G.global_argv[1]) {
9048 * "bash <script>" (which is never interactive (unless -i?))
9049 * sources $BASH_ENV here (without scanning $PATH).
9050 * If called as sh, does the same but with $ENV.
9051 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9055 debug_printf("running script '%s'\n", G.global_argv[0]);
9056 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9057 input = xfopen_for_read(G.global_argv[0]);
9058 xfunc_error_retval = 1;
9059 remember_FILE(input);
9060 install_special_sighandlers();
9061 parse_and_run_file(input);
9062 #if ENABLE_FEATURE_CLEAN_UP
9063 fclose_and_forget(input);
9068 /* Up to here, shell was non-interactive. Now it may become one.
9069 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9072 /* A shell is interactive if the '-i' flag was given,
9073 * or if all of the following conditions are met:
9075 * no arguments remaining or the -s flag given
9076 * standard input is a terminal
9077 * standard output is a terminal
9078 * Refer to Posix.2, the description of the 'sh' utility.
9081 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9082 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9083 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9084 if (G_saved_tty_pgrp < 0)
9085 G_saved_tty_pgrp = 0;
9087 /* try to dup stdin to high fd#, >= 255 */
9088 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9089 if (G_interactive_fd < 0) {
9090 /* try to dup to any fd */
9091 G_interactive_fd = dup(STDIN_FILENO);
9092 if (G_interactive_fd < 0) {
9094 G_interactive_fd = 0;
9095 G_saved_tty_pgrp = 0;
9098 // TODO: track & disallow any attempts of user
9099 // to (inadvertently) close/redirect G_interactive_fd
9101 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9102 if (G_interactive_fd) {
9103 close_on_exec_on(G_interactive_fd);
9105 if (G_saved_tty_pgrp) {
9106 /* If we were run as 'hush &', sleep until we are
9107 * in the foreground (tty pgrp == our pgrp).
9108 * If we get started under a job aware app (like bash),
9109 * make sure we are now in charge so we don't fight over
9110 * who gets the foreground */
9112 pid_t shell_pgrp = getpgrp();
9113 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9114 if (G_saved_tty_pgrp == shell_pgrp)
9116 /* send TTIN to ourself (should stop us) */
9117 kill(- shell_pgrp, SIGTTIN);
9121 /* Install more signal handlers */
9122 install_special_sighandlers();
9124 if (G_saved_tty_pgrp) {
9125 /* Set other signals to restore saved_tty_pgrp */
9126 install_fatal_sighandlers();
9127 /* Put ourselves in our own process group
9128 * (bash, too, does this only if ctty is available) */
9129 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9130 /* Grab control of the terminal */
9131 tcsetpgrp(G_interactive_fd, getpid());
9133 enable_restore_tty_pgrp_on_exit();
9135 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9137 const char *hp = get_local_var_value("HISTFILE");
9139 hp = get_local_var_value("HOME");
9141 hp = concat_path_file(hp, ".hush_history");
9146 G.line_input_state->hist_file = hp;
9147 //set_local_var(xasprintf("HISTFILE=%s", ...));
9149 # if ENABLE_FEATURE_SH_HISTFILESIZE
9150 hp = get_local_var_value("HISTFILESIZE");
9151 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9156 install_special_sighandlers();
9158 #elif ENABLE_HUSH_INTERACTIVE
9159 /* No job control compiled in, only prompt/line editing */
9160 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9161 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9162 if (G_interactive_fd < 0) {
9163 /* try to dup to any fd */
9164 G_interactive_fd = dup(STDIN_FILENO);
9165 if (G_interactive_fd < 0)
9167 G_interactive_fd = 0;
9170 if (G_interactive_fd) {
9171 close_on_exec_on(G_interactive_fd);
9173 install_special_sighandlers();
9175 /* We have interactiveness code disabled */
9176 install_special_sighandlers();
9179 * if interactive but not a login shell, sources ~/.bashrc
9180 * (--norc turns this off, --rcfile <file> overrides)
9183 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9184 /* note: ash and hush share this string */
9185 printf("\n\n%s %s\n"
9186 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9189 "hush - the humble shell"
9193 parse_and_run_file(stdin);
9196 hush_exit(G.last_exitcode);
9203 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9208 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9209 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9211 int argc = string_array_len(argv);
9212 return applet_main_func(argc, argv);
9215 #if ENABLE_HUSH_TEST || BASH_TEST2
9216 static int FAST_FUNC builtin_test(char **argv)
9218 return run_applet_main(argv, test_main);
9221 #if ENABLE_HUSH_ECHO
9222 static int FAST_FUNC builtin_echo(char **argv)
9224 return run_applet_main(argv, echo_main);
9227 #if ENABLE_HUSH_PRINTF
9228 static int FAST_FUNC builtin_printf(char **argv)
9230 return run_applet_main(argv, printf_main);
9234 #if ENABLE_HUSH_HELP
9235 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9237 const struct built_in_command *x;
9240 "Built-in commands:\n"
9241 "------------------\n");
9242 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9244 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9246 return EXIT_SUCCESS;
9250 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9251 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9253 show_history(G.line_input_state);
9254 return EXIT_SUCCESS;
9258 static char **skip_dash_dash(char **argv)
9261 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9266 static int FAST_FUNC builtin_cd(char **argv)
9270 argv = skip_dash_dash(argv);
9272 if (newdir == NULL) {
9273 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9274 * bash says "bash: cd: HOME not set" and does nothing
9277 const char *home = get_local_var_value("HOME");
9278 newdir = home ? home : "/";
9280 if (chdir(newdir)) {
9281 /* Mimic bash message exactly */
9282 bb_perror_msg("cd: %s", newdir);
9283 return EXIT_FAILURE;
9285 /* Read current dir (get_cwd(1) is inside) and set PWD.
9286 * Note: do not enforce exporting. If PWD was unset or unexported,
9287 * set it again, but do not export. bash does the same.
9289 set_pwd_var(/*flag:*/ 0);
9290 return EXIT_SUCCESS;
9293 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9296 return EXIT_SUCCESS;
9299 static int FAST_FUNC builtin_eval(char **argv)
9301 int rcode = EXIT_SUCCESS;
9303 argv = skip_dash_dash(argv);
9305 char *str = expand_strvec_to_string(argv);
9307 * eval "echo Hi; done" ("done" is syntax error):
9308 * "echo Hi" will not execute too.
9310 parse_and_run_string(str);
9312 rcode = G.last_exitcode;
9317 static int FAST_FUNC builtin_exec(char **argv)
9319 argv = skip_dash_dash(argv);
9320 if (argv[0] == NULL)
9321 return EXIT_SUCCESS; /* bash does this */
9323 /* Careful: we can end up here after [v]fork. Do not restore
9324 * tty pgrp then, only top-level shell process does that */
9325 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9326 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9328 /* Saved-redirect fds, script fds and G_interactive_fd are still
9329 * open here. However, they are all CLOEXEC, and execv below
9330 * closes them. Try interactive "exec ls -l /proc/self/fd",
9331 * it should show no extra open fds in the "ls" process.
9332 * If we'd try to run builtins/NOEXECs, this would need improving.
9334 //close_saved_fds_and_FILE_fds();
9336 /* TODO: if exec fails, bash does NOT exit! We do.
9337 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9338 * and tcsetpgrp, and this is inherently racy.
9340 execvp_or_die(argv);
9343 static int FAST_FUNC builtin_exit(char **argv)
9345 debug_printf_exec("%s()\n", __func__);
9347 /* interactive bash:
9348 * # trap "echo EEE" EXIT
9351 * There are stopped jobs.
9352 * (if there are _stopped_ jobs, running ones don't count)
9355 * EEE (then bash exits)
9357 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9360 /* note: EXIT trap is run by hush_exit */
9361 argv = skip_dash_dash(argv);
9362 if (argv[0] == NULL)
9363 hush_exit(G.last_exitcode);
9364 /* mimic bash: exit 123abc == exit 255 + error msg */
9365 xfunc_error_retval = 255;
9366 /* bash: exit -2 == exit 254, no error msg */
9367 hush_exit(xatoi(argv[0]) & 0xff);
9370 #if ENABLE_HUSH_TYPE
9371 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9372 static int FAST_FUNC builtin_type(char **argv)
9374 int ret = EXIT_SUCCESS;
9380 if (0) {} /* make conditional compile easier below */
9381 /*else if (find_alias(*argv))
9382 type = "an alias";*/
9383 #if ENABLE_HUSH_FUNCTIONS
9384 else if (find_function(*argv))
9385 type = "a function";
9387 else if (find_builtin(*argv))
9388 type = "a shell builtin";
9389 else if ((path = find_in_path(*argv)) != NULL)
9392 bb_error_msg("type: %s: not found", *argv);
9397 printf("%s is %s\n", *argv, type);
9405 #if ENABLE_HUSH_READ
9406 /* Interruptibility of read builtin in bash
9407 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9409 * Empty trap makes read ignore corresponding signal, for any signal.
9412 * - terminates non-interactive shell;
9413 * - interrupts read in interactive shell;
9414 * if it has non-empty trap:
9415 * - executes trap and returns to command prompt in interactive shell;
9416 * - executes trap and returns to read in non-interactive shell;
9418 * - is ignored (does not interrupt) read in interactive shell;
9419 * - terminates non-interactive shell;
9420 * if it has non-empty trap:
9421 * - executes trap and returns to read;
9423 * - terminates shell (regardless of interactivity);
9424 * if it has non-empty trap:
9425 * - executes trap and returns to read;
9426 * SIGCHLD from children:
9427 * - does not interrupt read regardless of interactivity:
9428 * try: sleep 1 & read x; echo $x
9430 static int FAST_FUNC builtin_read(char **argv)
9440 /* "!": do not abort on errors.
9441 * Option string must start with "sr" to match BUILTIN_READ_xxx
9443 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9444 if (read_flags == (uint32_t)-1)
9445 return EXIT_FAILURE;
9447 ifs = get_local_var_value("IFS"); /* can be NULL */
9450 r = shell_builtin_read(set_local_var_from_halves,
9460 if ((uintptr_t)r == 1 && errno == EINTR) {
9461 unsigned sig = check_and_run_traps();
9466 if ((uintptr_t)r > 1) {
9467 bb_error_msg("%s", r);
9468 r = (char*)(uintptr_t)1;
9471 return (uintptr_t)r;
9475 #if ENABLE_HUSH_UMASK
9476 static int FAST_FUNC builtin_umask(char **argv)
9483 argv = skip_dash_dash(argv);
9485 mode_t old_mask = mask;
9487 /* numeric umasks are taken as-is */
9488 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9489 if (!isdigit(argv[0][0]))
9491 mask = bb_parse_mode(argv[0], mask);
9492 if (!isdigit(argv[0][0]))
9494 if ((unsigned)mask > 0777) {
9497 * bash: umask: 'q': invalid symbolic mode operator
9498 * bash: umask: 999: octal number out of range
9500 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9505 printf("%04o\n", (unsigned) mask);
9506 /* fall through and restore mask which we set to 0 */
9510 return !rc; /* rc != 0 - success */
9514 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9515 static void print_escaped(const char *s)
9520 const char *p = strchrnul(s, '\'');
9521 /* print 'xxxx', possibly just '' */
9522 printf("'%.*s'", (int)(p - s), s);
9527 /* s points to '; print "'''...'''" */
9529 do putchar('\''); while (*++s == '\'');
9535 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9536 static int helper_export_local(char **argv, unsigned flags)
9540 char *name_end = strchrnul(name, '=');
9542 /* So far we do not check that name is valid (TODO?) */
9544 if (*name_end == '\0') {
9545 struct variable *var, **vpp;
9547 vpp = get_ptr_to_local_var(name, name_end - name);
9548 var = vpp ? *vpp : NULL;
9550 if (flags & SETFLAG_UNEXPORT) {
9551 /* export -n NAME (without =VALUE) */
9553 var->flg_export = 0;
9554 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9556 } /* else: export -n NOT_EXISTING_VAR: no-op */
9559 if (flags & SETFLAG_EXPORT) {
9560 /* export NAME (without =VALUE) */
9562 var->flg_export = 1;
9563 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9564 putenv(var->varstr);
9568 if (flags & SETFLAG_MAKE_RO) {
9569 /* readonly NAME (without =VALUE) */
9571 var->flg_read_only = 1;
9575 # if ENABLE_HUSH_LOCAL
9576 /* Is this "local" bltin? */
9577 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9578 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9579 if (var && var->func_nest_level == lvl) {
9580 /* "local x=abc; ...; local x" - ignore second local decl */
9585 /* Exporting non-existing variable.
9586 * bash does not put it in environment,
9587 * but remembers that it is exported,
9588 * and does put it in env when it is set later.
9589 * We just set it to "" and export.
9591 /* Or, it's "local NAME" (without =VALUE).
9592 * bash sets the value to "".
9594 /* Or, it's "readonly NAME" (without =VALUE).
9595 * bash remembers NAME and disallows its creation
9598 name = xasprintf("%s=", name);
9600 /* (Un)exporting/making local NAME=VALUE */
9601 name = xstrdup(name);
9603 if (set_local_var(name, flags))
9604 return EXIT_FAILURE;
9606 return EXIT_SUCCESS;
9610 #if ENABLE_HUSH_EXPORT
9611 static int FAST_FUNC builtin_export(char **argv)
9613 unsigned opt_unexport;
9615 #if ENABLE_HUSH_EXPORT_N
9616 /* "!": do not abort on errors */
9617 opt_unexport = getopt32(argv, "!n");
9618 if (opt_unexport == (uint32_t)-1)
9619 return EXIT_FAILURE;
9626 if (argv[0] == NULL) {
9633 /* ash emits: export VAR='VAL'
9634 * bash: declare -x VAR="VAL"
9635 * we follow ash example */
9636 const char *s = *e++;
9637 const char *p = strchr(s, '=');
9639 if (!p) /* wtf? take next variable */
9642 printf("export %.*s", (int)(p - s) + 1, s);
9643 print_escaped(p + 1);
9647 /*fflush_all(); - done after each builtin anyway */
9649 return EXIT_SUCCESS;
9652 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9656 #if ENABLE_HUSH_LOCAL
9657 static int FAST_FUNC builtin_local(char **argv)
9659 if (G.func_nest_level == 0) {
9660 bb_error_msg("%s: not in a function", argv[0]);
9661 return EXIT_FAILURE; /* bash compat */
9664 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9668 #if ENABLE_HUSH_READONLY
9669 static int FAST_FUNC builtin_readonly(char **argv)
9672 if (*argv == NULL) {
9673 /* bash: readonly [-p]: list all readonly VARs
9674 * (-p has no effect in bash)
9677 for (e = G.top_var; e; e = e->next) {
9678 if (e->flg_read_only) {
9679 //TODO: quote value: readonly VAR='VAL'
9680 printf("readonly %s\n", e->varstr);
9683 return EXIT_SUCCESS;
9685 return helper_export_local(argv, SETFLAG_MAKE_RO);
9689 #if ENABLE_HUSH_UNSET
9690 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9691 static int FAST_FUNC builtin_unset(char **argv)
9696 /* "!": do not abort on errors */
9697 /* "+": stop at 1st non-option */
9698 opts = getopt32(argv, "!+vf");
9699 if (opts == (unsigned)-1)
9700 return EXIT_FAILURE;
9702 bb_error_msg("unset: -v and -f are exclusive");
9703 return EXIT_FAILURE;
9709 if (!(opts & 2)) { /* not -f */
9710 if (unset_local_var(*argv)) {
9711 /* unset <nonexistent_var> doesn't fail.
9712 * Error is when one tries to unset RO var.
9713 * Message was printed by unset_local_var. */
9717 # if ENABLE_HUSH_FUNCTIONS
9729 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9730 * built-in 'set' handler
9732 * set [-abCefhmnuvx] [-o option] [argument...]
9733 * set [+abCefhmnuvx] [+o option] [argument...]
9734 * set -- [argument...]
9737 * Implementations shall support the options in both their hyphen and
9738 * plus-sign forms. These options can also be specified as options to sh.
9740 * Write out all variables and their values: set
9741 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9742 * Turn on the -x and -v options: set -xv
9743 * Unset all positional parameters: set --
9744 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9745 * Set the positional parameters to the expansion of x, even if x expands
9746 * with a leading '-' or '+': set -- $x
9748 * So far, we only support "set -- [argument...]" and some of the short names.
9750 static int FAST_FUNC builtin_set(char **argv)
9753 char **pp, **g_argv;
9754 char *arg = *++argv;
9758 for (e = G.top_var; e; e = e->next)
9760 return EXIT_SUCCESS;
9764 if (strcmp(arg, "--") == 0) {
9768 if (arg[0] != '+' && arg[0] != '-')
9770 for (n = 1; arg[n]; ++n) {
9771 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9773 if (arg[n] == 'o' && argv[1])
9776 } while ((arg = *++argv) != NULL);
9777 /* Now argv[0] is 1st argument */
9780 return EXIT_SUCCESS;
9783 /* NB: G.global_argv[0] ($0) is never freed/changed */
9784 g_argv = G.global_argv;
9785 if (G.global_args_malloced) {
9791 G.global_args_malloced = 1;
9792 pp = xzalloc(sizeof(pp[0]) * 2);
9793 pp[0] = g_argv[0]; /* retain $0 */
9796 /* This realloc's G.global_argv */
9797 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9799 G.global_argc = 1 + string_array_len(pp + 1);
9801 return EXIT_SUCCESS;
9803 /* Nothing known, so abort */
9805 bb_error_msg("set: %s: invalid option", arg);
9806 return EXIT_FAILURE;
9810 static int FAST_FUNC builtin_shift(char **argv)
9813 argv = skip_dash_dash(argv);
9815 n = bb_strtou(argv[0], NULL, 10);
9816 if (errno || n < 0) {
9817 /* shared string with ash.c */
9818 bb_error_msg("Illegal number: %s", argv[0]);
9820 * ash aborts in this case.
9821 * bash prints error message and set $? to 1.
9822 * Interestingly, for "shift 99999" bash does not
9823 * print error message, but does set $? to 1
9824 * (and does no shifting at all).
9828 if (n >= 0 && n < G.global_argc) {
9829 if (G_global_args_malloced) {
9832 free(G.global_argv[m++]);
9835 memmove(&G.global_argv[1], &G.global_argv[n+1],
9836 G.global_argc * sizeof(G.global_argv[0]));
9837 return EXIT_SUCCESS;
9839 return EXIT_FAILURE;
9842 static int FAST_FUNC builtin_source(char **argv)
9844 char *arg_path, *filename;
9847 char *args_need_save;
9848 #if ENABLE_HUSH_FUNCTIONS
9852 argv = skip_dash_dash(argv);
9855 /* bash says: "bash: .: filename argument required" */
9856 return 2; /* bash compat */
9859 if (!strchr(filename, '/')) {
9860 arg_path = find_in_path(filename);
9862 filename = arg_path;
9864 input = remember_FILE(fopen_or_warn(filename, "r"));
9867 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9868 /* POSIX: non-interactive shell should abort here,
9869 * not merely fail. So far no one complained :)
9871 return EXIT_FAILURE;
9874 #if ENABLE_HUSH_FUNCTIONS
9875 sv_flg = G_flag_return_in_progress;
9876 /* "we are inside sourced file, ok to use return" */
9877 G_flag_return_in_progress = -1;
9879 args_need_save = argv[1]; /* used as a boolean variable */
9881 save_and_replace_G_args(&sv, argv);
9883 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9884 G.last_exitcode = 0;
9885 parse_and_run_file(input);
9886 fclose_and_forget(input);
9888 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9889 restore_G_args(&sv, argv);
9890 #if ENABLE_HUSH_FUNCTIONS
9891 G_flag_return_in_progress = sv_flg;
9894 return G.last_exitcode;
9897 #if ENABLE_HUSH_TRAP
9898 static int FAST_FUNC builtin_trap(char **argv)
9904 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9909 /* No args: print all trapped */
9910 for (i = 0; i < NSIG; ++i) {
9913 print_escaped(G_traps[i]);
9914 /* note: bash adds "SIG", but only if invoked
9915 * as "bash". If called as "sh", or if set -o posix,
9916 * then it prints short signal names.
9917 * We are printing short names: */
9918 printf(" %s\n", get_signame(i));
9921 /*fflush_all(); - done after each builtin anyway */
9922 return EXIT_SUCCESS;
9926 /* If first arg is a number: reset all specified signals */
9927 sig = bb_strtou(*argv, NULL, 10);
9933 sighandler_t handler;
9935 sig = get_signum(*argv++);
9938 /* Mimic bash message exactly */
9939 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9944 G_traps[sig] = xstrdup(new_cmd);
9946 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9947 get_signame(sig), sig, G_traps[sig]);
9949 /* There is no signal for 0 (EXIT) */
9954 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9956 /* We are removing trap handler */
9957 handler = pick_sighandler(sig);
9958 install_sighandler(sig, handler);
9963 if (!argv[1]) { /* no second arg */
9964 bb_error_msg("trap: invalid arguments");
9965 return EXIT_FAILURE;
9968 /* First arg is "-": reset all specified to default */
9969 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9970 /* Everything else: set arg as signal handler
9971 * (includes "" case, which ignores signal) */
9972 if (argv[0][0] == '-') {
9973 if (argv[0][1] == '\0') { /* "-" */
9974 /* new_cmd remains NULL: "reset these sigs" */
9977 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9980 /* else: "-something", no special meaning */
9985 goto process_sig_list;
9990 static struct pipe *parse_jobspec(const char *str)
9995 if (sscanf(str, "%%%u", &jobnum) != 1) {
9997 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9999 bb_error_msg("bad argument '%s'", str);
10002 /* It is "%%", "%+" or "%" - current job */
10003 jobnum = G.last_jobid;
10005 bb_error_msg("no current job");
10009 for (pi = G.job_list; pi; pi = pi->next) {
10010 if (pi->jobid == jobnum) {
10014 bb_error_msg("%u: no such job", jobnum);
10018 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10021 const char *status_string;
10023 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10024 for (job = G.job_list; job; job = job->next) {
10025 if (job->alive_cmds == job->stopped_cmds)
10026 status_string = "Stopped";
10028 status_string = "Running";
10030 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10033 clean_up_last_dead_job();
10035 return EXIT_SUCCESS;
10038 /* built-in 'fg' and 'bg' handler */
10039 static int FAST_FUNC builtin_fg_bg(char **argv)
10044 if (!G_interactive_fd)
10045 return EXIT_FAILURE;
10047 /* If they gave us no args, assume they want the last backgrounded task */
10049 for (pi = G.job_list; pi; pi = pi->next) {
10050 if (pi->jobid == G.last_jobid) {
10054 bb_error_msg("%s: no current job", argv[0]);
10055 return EXIT_FAILURE;
10058 pi = parse_jobspec(argv[1]);
10060 return EXIT_FAILURE;
10062 /* TODO: bash prints a string representation
10063 * of job being foregrounded (like "sleep 1 | cat") */
10064 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10065 /* Put the job into the foreground. */
10066 tcsetpgrp(G_interactive_fd, pi->pgrp);
10069 /* Restart the processes in the job */
10070 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10071 for (i = 0; i < pi->num_cmds; i++) {
10072 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10074 pi->stopped_cmds = 0;
10076 i = kill(- pi->pgrp, SIGCONT);
10078 if (errno == ESRCH) {
10079 delete_finished_job(pi);
10080 return EXIT_SUCCESS;
10082 bb_perror_msg("kill (SIGCONT)");
10085 if (argv[0][0] == 'f') {
10086 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10087 return checkjobs_and_fg_shell(pi);
10089 return EXIT_SUCCESS;
10093 #if ENABLE_HUSH_KILL
10094 static int FAST_FUNC builtin_kill(char **argv)
10098 # if ENABLE_HUSH_JOB
10099 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10107 if (argv[i][0] != '%')
10110 * "kill %N" - job kill
10111 * Converting to pgrp / pid kill
10113 pi = parse_jobspec(argv[i]);
10115 /* Eat bad jobspec */
10119 argv[j - 1] = argv[j];
10126 * In jobs started under job control, we signal
10127 * entire process group by kill -PGRP_ID.
10128 * This happens, f.e., in interactive shell.
10130 * Otherwise, we signal each child via
10131 * kill PID1 PID2 PID3.
10133 * sh -c 'sleep 1|sleep 1 & kill %1'
10134 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10135 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10137 n = G_interactive_fd ? 1 : pi->num_cmds;
10138 dst = alloca(n * sizeof(int)*4);
10140 if (G_interactive_fd)
10141 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10142 else for (j = 0; j < n; j++) {
10143 struct command *cmd = &pi->cmds[j];
10144 /* Skip exited members of the job */
10148 * kill_main has matching code to expect
10149 * leading space. Needed to not confuse
10150 * negative pids with "kill -SIGNAL_NO" syntax
10152 dst += sprintf(dst, " %u", (int)cmd->pid);
10155 } while (argv[++i]);
10159 if (argv[1] || ret == 0) {
10160 ret = run_applet_main(argv, kill_main);
10162 /* else: ret = 1, "kill %bad_jobspec" case */
10167 #if ENABLE_HUSH_WAIT
10168 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10169 #if !ENABLE_HUSH_JOB
10170 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10172 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10179 if (!sigisemptyset(&G.pending_set))
10182 /* waitpid is not interruptible by SA_RESTARTed
10183 * signals which we use. Thus, this ugly dance:
10186 /* Make sure possible SIGCHLD is stored in kernel's
10187 * pending signal mask before we call waitpid.
10188 * Or else we may race with SIGCHLD, lose it,
10189 * and get stuck in sigsuspend...
10191 sigfillset(&oldset); /* block all signals, remember old set */
10192 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10194 if (!sigisemptyset(&G.pending_set)) {
10195 /* Crap! we raced with some signal! */
10199 /*errno = 0; - checkjobs does this */
10200 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10201 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10202 debug_printf_exec("checkjobs:%d\n", ret);
10203 #if ENABLE_HUSH_JOB
10204 if (waitfor_pipe) {
10205 int rcode = job_exited_or_stopped(waitfor_pipe);
10206 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10209 sigprocmask(SIG_SETMASK, &oldset, NULL);
10214 /* if ECHILD, there are no children (ret is -1 or 0) */
10215 /* if ret == 0, no children changed state */
10216 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10217 if (errno == ECHILD || ret) {
10219 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10221 sigprocmask(SIG_SETMASK, &oldset, NULL);
10224 /* Wait for SIGCHLD or any other signal */
10225 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10226 /* Note: sigsuspend invokes signal handler */
10227 sigsuspend(&oldset);
10229 sigprocmask(SIG_SETMASK, &oldset, NULL);
10231 /* So, did we get a signal? */
10232 sig = check_and_run_traps();
10233 if (sig /*&& sig != SIGCHLD - always true */) {
10234 /* Do this for any (non-ignored) signal, not only for ^C */
10238 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10243 static int FAST_FUNC builtin_wait(char **argv)
10248 argv = skip_dash_dash(argv);
10249 if (argv[0] == NULL) {
10250 /* Don't care about wait results */
10251 /* Note 1: must wait until there are no more children */
10252 /* Note 2: must be interruptible */
10254 * $ sleep 3 & sleep 6 & wait
10255 * [1] 30934 sleep 3
10256 * [2] 30935 sleep 6
10259 * $ sleep 3 & sleep 6 & wait
10260 * [1] 30936 sleep 3
10261 * [2] 30937 sleep 6
10263 * ^C <-- after ~4 sec from keyboard
10266 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10270 pid_t pid = bb_strtou(*argv, NULL, 10);
10271 if (errno || pid <= 0) {
10272 #if ENABLE_HUSH_JOB
10273 if (argv[0][0] == '%') {
10274 struct pipe *wait_pipe;
10275 ret = 127; /* bash compat for bad jobspecs */
10276 wait_pipe = parse_jobspec(*argv);
10278 ret = job_exited_or_stopped(wait_pipe);
10280 ret = wait_for_child_or_signal(wait_pipe, 0);
10282 /* waiting on "last dead job" removes it */
10283 clean_up_last_dead_job();
10286 /* else: parse_jobspec() already emitted error msg */
10290 /* mimic bash message */
10291 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10292 ret = EXIT_FAILURE;
10293 continue; /* bash checks all argv[] */
10296 /* Do we have such child? */
10297 ret = waitpid(pid, &status, WNOHANG);
10301 if (errno == ECHILD) {
10302 if (pid == G.last_bg_pid) {
10303 /* "wait $!" but last bg task has already exited. Try:
10304 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10305 * In bash it prints exitcode 0, then 3.
10306 * In dash, it is 127.
10308 ret = G.last_bg_pid_exitcode;
10310 /* Example: "wait 1". mimic bash message */
10311 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10315 bb_perror_msg("wait %s", *argv);
10317 continue; /* bash checks all argv[] */
10320 /* Yes, and it still runs */
10321 ret = wait_for_child_or_signal(NULL, pid);
10323 /* Yes, and it just exited */
10324 process_wait_result(NULL, pid, status);
10325 ret = WEXITSTATUS(status);
10326 if (WIFSIGNALED(status))
10327 ret = 128 + WTERMSIG(status);
10335 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10336 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10339 def = bb_strtou(argv[1], NULL, 10);
10340 if (errno || def < def_min || argv[2]) {
10341 bb_error_msg("%s: bad arguments", argv[0]);
10349 #if ENABLE_HUSH_LOOPS
10350 static int FAST_FUNC builtin_break(char **argv)
10353 if (G.depth_of_loop == 0) {
10354 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10355 /* if we came from builtin_continue(), need to undo "= 1" */
10356 G.flag_break_continue = 0;
10357 return EXIT_SUCCESS; /* bash compat */
10359 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10361 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10362 if (depth == UINT_MAX)
10363 G.flag_break_continue = BC_BREAK;
10364 if (G.depth_of_loop < depth)
10365 G.depth_break_continue = G.depth_of_loop;
10367 return EXIT_SUCCESS;
10370 static int FAST_FUNC builtin_continue(char **argv)
10372 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10373 return builtin_break(argv);
10377 #if ENABLE_HUSH_FUNCTIONS
10378 static int FAST_FUNC builtin_return(char **argv)
10382 if (G_flag_return_in_progress != -1) {
10383 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10384 return EXIT_FAILURE; /* bash compat */
10387 G_flag_return_in_progress = 1;
10390 * out of range: wraps around at 256, does not error out
10391 * non-numeric param:
10392 * f() { false; return qwe; }; f; echo $?
10393 * bash: return: qwe: numeric argument required <== we do this
10394 * 255 <== we also do this
10396 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10401 #if ENABLE_HUSH_MEMLEAK
10402 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10407 # ifdef M_TRIM_THRESHOLD
10408 /* Optional. Reduces probability of false positives */
10411 /* Crude attempt to find where "free memory" starts,
10412 * sans fragmentation. */
10414 l = (unsigned long)p;
10417 if (l < (unsigned long)p) l = (unsigned long)p;
10423 struct mallinfo mi = mallinfo();
10424 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10425 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10429 if (!G.memleak_value)
10430 G.memleak_value = l;
10432 l -= G.memleak_value;
10439 /* Exitcode is "how many kilobytes we leaked since 1st call" */