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 die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(unsigned lineno, const char *fmt, ...)
1288 bb_error_msg("hush.c:%u", lineno);
1291 bb_verror_msg(fmt, p, NULL);
1293 if (!G_interactive_fd)
1297 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1300 bb_error_msg("syntax error: %s", msg);
1302 bb_error_msg("syntax error");
1305 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1307 bb_error_msg("syntax error at '%s'", msg);
1310 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1312 bb_error_msg("syntax error: unterminated %s", s);
1315 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1317 char msg[2] = { ch, '\0' };
1318 syntax_error_unterm_str(lineno, msg);
1321 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1327 bb_error_msg("hush.c:%u", lineno);
1329 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1333 # undef die_if_script
1334 # undef syntax_error
1335 # undef syntax_error_at
1336 # undef syntax_error_unterm_ch
1337 # undef syntax_error_unterm_str
1338 # undef syntax_error_unexpected_ch
1340 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1341 # define syntax_error(msg) syntax_error(__LINE__, msg)
1342 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1343 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1344 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1345 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1349 #if ENABLE_HUSH_INTERACTIVE
1350 static void cmdedit_update_prompt(void);
1352 # define cmdedit_update_prompt() ((void)0)
1356 /* Utility functions
1358 /* Replace each \x with x in place, return ptr past NUL. */
1359 static char *unbackslash(char *src)
1361 char *dst = src = strchrnul(src, '\\');
1365 if ((*dst++ = *src++) == '\0')
1371 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1392 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1393 v[count1 + count2] = NULL;
1396 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1400 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1402 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1403 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1406 #define add_strings_to_strings(strings, add, need_to_dup) \
1407 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1410 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1411 static char **add_string_to_strings(char **strings, char *add)
1416 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1419 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1421 char **ptr = add_string_to_strings(strings, add);
1422 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1425 #define add_string_to_strings(strings, add) \
1426 xx_add_string_to_strings(__LINE__, strings, add)
1429 static void free_strings(char **strings)
1443 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1447 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1457 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1461 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1467 /* fd was not open? */
1477 /* Manipulating the list of open FILEs */
1478 static FILE *remember_FILE(FILE *fp)
1481 struct FILE_list *n = xmalloc(sizeof(*n));
1482 n->next = G.FILE_list;
1486 close_on_exec_on(n->fd);
1490 static void fclose_and_forget(FILE *fp)
1492 struct FILE_list **pp = &G.FILE_list;
1494 struct FILE_list *cur = *pp;
1495 if (cur->fp == fp) {
1504 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1506 struct FILE_list *fl = G.FILE_list;
1509 /* We use it only on script files, they are all CLOEXEC */
1510 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1511 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1518 static void restore_redirected_FILEs(void)
1520 struct FILE_list *fl = G.FILE_list;
1522 int should_be = fileno(fl->fp);
1523 if (fl->fd != should_be) {
1524 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1525 xmove_fd(fl->fd, should_be);
1531 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1532 static void close_all_FILE_list(void)
1534 struct FILE_list *fl = G.FILE_list;
1536 /* fclose would also free FILE object.
1537 * It is disastrous if we share memory with a vforked parent.
1538 * I'm not sure we never come here after vfork.
1539 * Therefore just close fd, nothing more.
1541 /*fclose(fl->fp); - unsafe */
1549 /* Helpers for setting new $n and restoring them back
1551 typedef struct save_arg_t {
1555 IF_HUSH_SET(smallint sv_g_malloced;)
1558 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1560 sv->sv_argv0 = argv[0];
1561 sv->sv_g_argv = G.global_argv;
1562 sv->sv_g_argc = G.global_argc;
1563 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1565 argv[0] = G.global_argv[0]; /* retain $0 */
1566 G.global_argv = argv;
1567 IF_HUSH_SET(G.global_args_malloced = 0;)
1569 G.global_argc = 1 + string_array_len(argv + 1);
1572 static void restore_G_args(save_arg_t *sv, char **argv)
1575 if (G.global_args_malloced) {
1576 /* someone ran "set -- arg1 arg2 ...", undo */
1577 char **pp = G.global_argv;
1578 while (*++pp) /* note: does not free $0 */
1580 free(G.global_argv);
1583 argv[0] = sv->sv_argv0;
1584 G.global_argv = sv->sv_g_argv;
1585 G.global_argc = sv->sv_g_argc;
1586 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1590 /* Basic theory of signal handling in shell
1591 * ========================================
1592 * This does not describe what hush does, rather, it is current understanding
1593 * what it _should_ do. If it doesn't, it's a bug.
1594 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1596 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1597 * is finished or backgrounded. It is the same in interactive and
1598 * non-interactive shells, and is the same regardless of whether
1599 * a user trap handler is installed or a shell special one is in effect.
1600 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1601 * backgrounds (i.e. stops) or kills all members of currently running
1604 * Wait builtin is interruptible by signals for which user trap is set
1605 * or by SIGINT in interactive shell.
1607 * Trap handlers will execute even within trap handlers. (right?)
1609 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1610 * except for handlers set to '' (empty string).
1612 * If job control is off, backgrounded commands ("cmd &")
1613 * have SIGINT, SIGQUIT set to SIG_IGN.
1615 * Commands which are run in command substitution ("`cmd`")
1616 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1618 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1619 * by the shell from its parent.
1621 * Signals which differ from SIG_DFL action
1622 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1625 * SIGTERM (interactive): ignore
1626 * SIGHUP (interactive):
1627 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1628 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1629 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1630 * that all pipe members are stopped. Try this in bash:
1631 * while :; do :; done - ^Z does not background it
1632 * (while :; do :; done) - ^Z backgrounds it
1633 * SIGINT (interactive): wait for last pipe, ignore the rest
1634 * of the command line, show prompt. NB: ^C does not send SIGINT
1635 * to interactive shell while shell is waiting for a pipe,
1636 * since shell is bg'ed (is not in foreground process group).
1637 * Example 1: this waits 5 sec, but does not execute ls:
1638 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1639 * Example 2: this does not wait and does not execute ls:
1640 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1641 * Example 3: this does not wait 5 sec, but executes ls:
1642 * "sleep 5; ls -l" + press ^C
1643 * Example 4: this does not wait and does not execute ls:
1644 * "sleep 5 & wait; ls -l" + press ^C
1646 * (What happens to signals which are IGN on shell start?)
1647 * (What happens with signal mask on shell start?)
1649 * Old implementation
1650 * ==================
1651 * We use in-kernel pending signal mask to determine which signals were sent.
1652 * We block all signals which we don't want to take action immediately,
1653 * i.e. we block all signals which need to have special handling as described
1654 * above, and all signals which have traps set.
1655 * After each pipe execution, we extract any pending signals via sigtimedwait()
1658 * unsigned special_sig_mask: a mask of such "special" signals
1659 * sigset_t blocked_set: current blocked signal set
1662 * clear bit in blocked_set unless it is also in special_sig_mask
1663 * "trap 'cmd' SIGxxx":
1664 * set bit in blocked_set (even if 'cmd' is '')
1665 * after [v]fork, if we plan to be a shell:
1666 * unblock signals with special interactive handling
1667 * (child shell is not interactive),
1668 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1669 * after [v]fork, if we plan to exec:
1670 * POSIX says fork clears pending signal mask in child - no need to clear it.
1671 * Restore blocked signal set to one inherited by shell just prior to exec.
1673 * Note: as a result, we do not use signal handlers much. The only uses
1674 * are to count SIGCHLDs
1675 * and to restore tty pgrp on signal-induced exit.
1678 * Standard says "When a subshell is entered, traps that are not being ignored
1679 * are set to the default actions". bash interprets it so that traps which
1680 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1682 * Problem: the above approach makes it unwieldy to catch signals while
1683 * we are in read builtin, or while we read commands from stdin:
1684 * masked signals are not visible!
1686 * New implementation
1687 * ==================
1688 * We record each signal we are interested in by installing signal handler
1689 * for them - a bit like emulating kernel pending signal mask in userspace.
1690 * We are interested in: signals which need to have special handling
1691 * as described above, and all signals which have traps set.
1692 * Signals are recorded in pending_set.
1693 * After each pipe execution, we extract any pending signals
1696 * unsigned special_sig_mask: a mask of shell-special signals.
1697 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1698 * char *traps[sig] if trap for sig is set (even if it's '').
1699 * sigset_t pending_set: set of sigs we received.
1702 * if sig is in special_sig_mask, set handler back to:
1703 * record_pending_signo, or to IGN if it's a tty stop signal
1704 * if sig is in fatal_sig_mask, set handler back to sigexit.
1705 * else: set handler back to SIG_DFL
1706 * "trap 'cmd' SIGxxx":
1707 * set handler to record_pending_signo.
1709 * set handler to SIG_IGN.
1710 * after [v]fork, if we plan to be a shell:
1711 * set signals with special interactive handling to SIG_DFL
1712 * (because child shell is not interactive),
1713 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1714 * after [v]fork, if we plan to exec:
1715 * POSIX says fork clears pending signal mask in child - no need to clear it.
1717 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1718 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1721 * Standard says "When a subshell is entered, traps that are not being ignored
1722 * are set to the default actions". bash interprets it so that traps which
1723 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1726 SPECIAL_INTERACTIVE_SIGS = 0
1731 SPECIAL_JOBSTOP_SIGS = 0
1740 static void record_pending_signo(int sig)
1742 sigaddset(&G.pending_set, sig);
1743 #if ENABLE_HUSH_FAST
1744 if (sig == SIGCHLD) {
1746 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1751 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1753 struct sigaction old_sa;
1755 /* We could use signal() to install handlers... almost:
1756 * except that we need to mask ALL signals while handlers run.
1757 * I saw signal nesting in strace, race window isn't small.
1758 * SA_RESTART is also needed, but in Linux, signal()
1759 * sets SA_RESTART too.
1761 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1762 /* sigfillset(&G.sa.sa_mask); - already done */
1763 /* G.sa.sa_flags = SA_RESTART; - already done */
1764 G.sa.sa_handler = handler;
1765 sigaction(sig, &G.sa, &old_sa);
1766 return old_sa.sa_handler;
1769 static void hush_exit(int exitcode) NORETURN;
1771 static void restore_ttypgrp_and__exit(void) NORETURN;
1772 static void restore_ttypgrp_and__exit(void)
1774 /* xfunc has failed! die die die */
1775 /* no EXIT traps, this is an escape hatch! */
1777 hush_exit(xfunc_error_retval);
1782 /* Needed only on some libc:
1783 * It was observed that on exit(), fgetc'ed buffered data
1784 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1785 * With the net effect that even after fork(), not vfork(),
1786 * exit() in NOEXECed applet in "sh SCRIPT":
1787 * noexec_applet_here
1788 * echo END_OF_SCRIPT
1789 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1790 * This makes "echo END_OF_SCRIPT" executed twice.
1791 * Similar problems can be seen with die_if_script() -> xfunc_die()
1792 * and in `cmd` handling.
1793 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1795 static void fflush_and__exit(void) NORETURN;
1796 static void fflush_and__exit(void)
1799 _exit(xfunc_error_retval);
1802 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1803 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1804 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1805 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1807 /* Restores tty foreground process group, and exits.
1808 * May be called as signal handler for fatal signal
1809 * (will resend signal to itself, producing correct exit state)
1810 * or called directly with -EXITCODE.
1811 * We also call it if xfunc is exiting.
1813 static void sigexit(int sig) NORETURN;
1814 static void sigexit(int sig)
1816 /* Careful: we can end up here after [v]fork. Do not restore
1817 * tty pgrp then, only top-level shell process does that */
1818 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1819 /* Disable all signals: job control, SIGPIPE, etc.
1820 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1822 sigprocmask_allsigs(SIG_BLOCK);
1823 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1826 /* Not a signal, just exit */
1830 kill_myself_with_sig(sig); /* does not return */
1834 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1835 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1839 static sighandler_t pick_sighandler(unsigned sig)
1841 sighandler_t handler = SIG_DFL;
1842 if (sig < sizeof(unsigned)*8) {
1843 unsigned sigmask = (1 << sig);
1847 if (G_fatal_sig_mask & sigmask)
1851 /* sig has special handling? */
1852 if (G.special_sig_mask & sigmask) {
1853 handler = record_pending_signo;
1854 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1855 * in order to ignore them: they will be raised
1856 * in an endless loop when we try to do some
1857 * terminal ioctls! We do have to _ignore_ these.
1859 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1866 /* Restores tty foreground process group, and exits. */
1867 static void hush_exit(int exitcode)
1869 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1870 save_history(G.line_input_state);
1874 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1876 /* argv[0] is unused */
1877 argv[1] = G_traps[0];
1879 G.exiting = 1; /* prevent EXIT trap recursion */
1880 /* Note: G_traps[0] is not cleared!
1881 * "trap" will still show it, if executed
1886 #if ENABLE_FEATURE_CLEAN_UP
1888 struct variable *cur_var;
1889 if (G.cwd != bb_msg_unknown)
1891 cur_var = G.top_var;
1893 struct variable *tmp = cur_var;
1894 if (!cur_var->max_len)
1895 free(cur_var->varstr);
1896 cur_var = cur_var->next;
1904 sigexit(- (exitcode & 0xff));
1911 //TODO: return a mask of ALL handled sigs?
1912 static int check_and_run_traps(void)
1919 if (sigisemptyset(&G.pending_set))
1924 if (sigismember(&G.pending_set, sig)) {
1925 sigdelset(&G.pending_set, sig);
1928 } while (sig < NSIG);
1931 if (G_traps && G_traps[sig]) {
1932 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1933 if (G_traps[sig][0]) {
1934 /* We have user-defined handler */
1935 smalluint save_rcode;
1937 /* argv[0] is unused */
1938 argv[1] = G_traps[sig];
1940 save_rcode = G.last_exitcode;
1942 //FIXME: shouldn't it be set to 128 + sig instead?
1943 G.last_exitcode = save_rcode;
1945 } /* else: "" trap, ignoring signal */
1948 /* not a trap: special action */
1951 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1958 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1959 /* bash is observed to signal whole process groups,
1960 * not individual processes */
1961 for (job = G.job_list; job; job = job->next) {
1964 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1965 if (kill(- job->pgrp, SIGHUP) == 0)
1966 kill(- job->pgrp, SIGCONT);
1971 #if ENABLE_HUSH_FAST
1973 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1975 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1977 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1978 * This simplifies wait builtin a bit.
1982 default: /* ignored: */
1983 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1984 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1986 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1987 * Example: wait is not interrupted by TERM
1988 * in interactive shell, because TERM is ignored.
1997 static const char *get_cwd(int force)
1999 if (force || G.cwd == NULL) {
2000 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2001 * we must not try to free(bb_msg_unknown) */
2002 if (G.cwd == bb_msg_unknown)
2004 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2006 G.cwd = bb_msg_unknown;
2013 * Shell and environment variable support
2015 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2017 struct variable **pp;
2018 struct variable *cur;
2021 while ((cur = *pp) != NULL) {
2022 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2029 static const char* FAST_FUNC get_local_var_value(const char *name)
2031 struct variable **vpp;
2032 unsigned len = strlen(name);
2034 if (G.expanded_assignments) {
2035 char **cpp = G.expanded_assignments;
2038 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2039 return cp + len + 1;
2044 vpp = get_ptr_to_local_var(name, len);
2046 return (*vpp)->varstr + len + 1;
2048 if (strcmp(name, "PPID") == 0)
2049 return utoa(G.root_ppid);
2050 // bash compat: UID? EUID?
2051 #if ENABLE_HUSH_RANDOM_SUPPORT
2052 if (strcmp(name, "RANDOM") == 0)
2053 return utoa(next_random(&G.random_gen));
2058 /* str holds "NAME=VAL" and is expected to be malloced.
2059 * We take ownership of it.
2061 #define SETFLAG_EXPORT (1 << 0)
2062 #define SETFLAG_UNEXPORT (1 << 1)
2063 #define SETFLAG_MAKE_RO (1 << 2)
2064 #define SETFLAG_LOCAL_SHIFT 3
2065 static int set_local_var(char *str, unsigned flags)
2067 struct variable **var_pp;
2068 struct variable *cur;
2069 char *free_me = NULL;
2072 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2074 eq_sign = strchr(str, '=');
2075 if (!eq_sign) { /* not expected to ever happen? */
2080 name_len = eq_sign - str + 1; /* including '=' */
2081 var_pp = &G.top_var;
2082 while ((cur = *var_pp) != NULL) {
2083 if (strncmp(cur->varstr, str, name_len) != 0) {
2084 var_pp = &cur->next;
2088 /* We found an existing var with this name */
2089 if (cur->flg_read_only) {
2090 bb_error_msg("%s: readonly variable", str);
2092 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2093 //but export per se succeeds (does put the var in env). We don't mimic that.
2096 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2097 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2102 #if ENABLE_HUSH_LOCAL
2103 if (cur->func_nest_level < local_lvl) {
2104 /* New variable is declared as local,
2105 * and existing one is global, or local
2106 * from enclosing function.
2107 * Remove and save old one: */
2108 *var_pp = cur->next;
2109 cur->next = *G.shadowed_vars_pp;
2110 *G.shadowed_vars_pp = cur;
2111 /* bash 3.2.33(1) and exported vars:
2113 * # f() { local z=a; env | grep ^z; }
2119 if (cur->flg_export)
2120 flags |= SETFLAG_EXPORT;
2124 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2129 if (cur->max_len != 0) {
2130 if (cur->max_len >= strlen(str)) {
2131 /* This one is from startup env, reuse space */
2132 strcpy(cur->varstr, str);
2137 goto set_str_and_exp;
2139 /* max_len == 0 signifies "malloced" var, which we can
2140 * (and have to) free. But we can't free(cur->varstr) here:
2141 * if cur->flg_export is 1, it is in the environment.
2142 * We should either unsetenv+free, or wait until putenv,
2143 * then putenv(new)+free(old).
2145 free_me = cur->varstr;
2146 goto set_str_and_exp;
2149 /* Not found - create new variable struct */
2150 cur = xzalloc(sizeof(*cur));
2151 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2152 cur->next = *var_pp;
2158 #if !BB_MMU || ENABLE_HUSH_READONLY
2159 if (flags & SETFLAG_MAKE_RO) {
2160 cur->flg_read_only = 1;
2163 if (flags & SETFLAG_EXPORT)
2164 cur->flg_export = 1;
2165 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2166 cmdedit_update_prompt();
2167 if (cur->flg_export) {
2168 if (flags & SETFLAG_UNEXPORT) {
2169 cur->flg_export = 0;
2170 /* unsetenv was already done */
2173 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2174 i = putenv(cur->varstr);
2175 /* only now we can free old exported malloced string */
2184 /* Used at startup and after each cd */
2185 static void set_pwd_var(unsigned flag)
2187 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2190 static int unset_local_var_len(const char *name, int name_len)
2192 struct variable *cur;
2193 struct variable **var_pp;
2196 return EXIT_SUCCESS;
2197 var_pp = &G.top_var;
2198 while ((cur = *var_pp) != NULL) {
2199 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2200 if (cur->flg_read_only) {
2201 bb_error_msg("%s: readonly variable", name);
2202 return EXIT_FAILURE;
2204 *var_pp = cur->next;
2205 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2206 bb_unsetenv(cur->varstr);
2207 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2208 cmdedit_update_prompt();
2212 return EXIT_SUCCESS;
2214 var_pp = &cur->next;
2216 return EXIT_SUCCESS;
2219 #if ENABLE_HUSH_UNSET
2220 static int unset_local_var(const char *name)
2222 return unset_local_var_len(name, strlen(name));
2226 static void unset_vars(char **strings)
2234 const char *eq = strchrnul(*v, '=');
2235 unset_local_var_len(*v, (int)(eq - *v));
2241 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2242 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2244 char *var = xasprintf("%s=%s", name, val);
2245 set_local_var(var, /*flag:*/ 0);
2251 * Helpers for "var1=val1 var2=val2 cmd" feature
2253 static void add_vars(struct variable *var)
2255 struct variable *next;
2259 var->next = G.top_var;
2261 if (var->flg_export) {
2262 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2263 putenv(var->varstr);
2265 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2271 static struct variable *set_vars_and_save_old(char **strings)
2274 struct variable *old = NULL;
2280 struct variable *var_p;
2281 struct variable **var_pp;
2284 eq = strchr(*s, '=');
2286 var_pp = get_ptr_to_local_var(*s, eq - *s);
2289 if (var_p->flg_read_only) {
2291 bb_error_msg("%s: readonly variable", *s);
2293 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2294 * If VAR is readonly, leaving it in the list
2295 * after asssignment error (msg above)
2296 * causes doubled error message later, on unset.
2298 debug_printf_env("removing/freeing '%s' element\n", *s);
2301 do { *p = p[1]; p++; } while (*p);
2304 /* Remove variable from global linked list */
2305 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2306 *var_pp = var_p->next;
2307 /* Add it to returned list */
2311 set_local_var(*s, SETFLAG_EXPORT);
2323 static void reinit_unicode_for_hush(void)
2325 /* Unicode support should be activated even if LANG is set
2326 * _during_ shell execution, not only if it was set when
2327 * shell was started. Therefore, re-check LANG every time:
2329 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2330 || ENABLE_UNICODE_USING_LOCALE
2332 const char *s = get_local_var_value("LC_ALL");
2333 if (!s) s = get_local_var_value("LC_CTYPE");
2334 if (!s) s = get_local_var_value("LANG");
2340 * in_str support (strings, and "strings" read from files).
2343 #if ENABLE_HUSH_INTERACTIVE
2344 /* To test correct lineedit/interactive behavior, type from command line:
2350 * It exercises a lot of corner cases.
2352 static void cmdedit_update_prompt(void)
2354 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2355 G.PS1 = get_local_var_value("PS1");
2358 G.PS2 = get_local_var_value("PS2");
2365 static const char *setup_prompt_string(int promptmode)
2367 const char *prompt_str;
2368 debug_printf("setup_prompt_string %d ", promptmode);
2369 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2370 /* Set up the prompt */
2371 if (promptmode == 0) { /* PS1 */
2373 /* bash uses $PWD value, even if it is set by user.
2374 * It uses current dir only if PWD is unset.
2375 * We always use current dir. */
2376 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2381 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2382 debug_printf("prompt_str '%s'\n", prompt_str);
2385 static int get_user_input(struct in_str *i)
2388 const char *prompt_str;
2390 prompt_str = setup_prompt_string(i->promptmode);
2391 # if ENABLE_FEATURE_EDITING
2393 reinit_unicode_for_hush();
2394 if (G.flag_SIGINT) {
2395 /* There was ^C'ed, make it look prettier: */
2399 /* buglet: SIGINT will not make new prompt to appear _at once_,
2400 * only after <Enter>. (^C works immediately) */
2401 r = read_line_input(G.line_input_state, prompt_str,
2402 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2405 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2407 write(STDOUT_FILENO, "^C", 2);
2410 check_and_run_traps();
2411 if (r != 0 && !G.flag_SIGINT)
2413 /* ^C or SIGINT: repeat */
2414 G.last_exitcode = 128 + SIGINT;
2417 /* EOF/error detected */
2419 i->peek_buf[0] = r = EOF;
2422 i->p = G.user_input_buf;
2423 return (unsigned char)*i->p++;
2427 if (i->last_char == '\0' || i->last_char == '\n') {
2428 /* Why check_and_run_traps here? Try this interactively:
2429 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2430 * $ <[enter], repeatedly...>
2431 * Without check_and_run_traps, handler never runs.
2433 check_and_run_traps();
2434 fputs(prompt_str, stdout);
2437 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2439 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2440 * no ^C masking happens during fgetc, no special code for ^C:
2441 * it generates SIGINT as usual.
2443 check_and_run_traps();
2445 G.last_exitcode = 128 + SIGINT;
2452 /* This is the magic location that prints prompts
2453 * and gets data back from the user */
2454 static int fgetc_interactive(struct in_str *i)
2457 /* If it's interactive stdin, get new line. */
2458 if (G_interactive_fd && i->file == stdin) {
2459 /* Returns first char (or EOF), the rest is in i->p[] */
2460 ch = get_user_input(i);
2461 i->promptmode = 1; /* PS2 */
2463 /* Not stdin: script file, sourced file, etc */
2464 do ch = fgetc(i->file); while (ch == '\0');
2469 static inline int fgetc_interactive(struct in_str *i)
2472 do ch = fgetc(i->file); while (ch == '\0');
2475 #endif /* INTERACTIVE */
2477 static int i_getch(struct in_str *i)
2482 /* string-based in_str */
2483 ch = (unsigned char)*i->p;
2492 /* FILE-based in_str */
2494 #if ENABLE_FEATURE_EDITING
2495 /* This can be stdin, check line editing char[] buffer */
2496 if (i->p && *i->p != '\0') {
2497 ch = (unsigned char)*i->p++;
2501 /* peek_buf[] is an int array, not char. Can contain EOF. */
2502 ch = i->peek_buf[0];
2504 int ch2 = i->peek_buf[1];
2505 i->peek_buf[0] = ch2;
2506 if (ch2 == 0) /* very likely, avoid redundant write */
2512 ch = fgetc_interactive(i);
2514 debug_printf("file_get: got '%c' %d\n", ch, ch);
2519 static int i_peek(struct in_str *i)
2524 /* string-based in_str */
2525 /* Doesn't report EOF on NUL. None of the callers care. */
2526 return (unsigned char)*i->p;
2529 /* FILE-based in_str */
2531 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2532 /* This can be stdin, check line editing char[] buffer */
2533 if (i->p && *i->p != '\0')
2534 return (unsigned char)*i->p;
2536 /* peek_buf[] is an int array, not char. Can contain EOF. */
2537 ch = i->peek_buf[0];
2541 /* Need to get a new char */
2542 ch = fgetc_interactive(i);
2543 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2545 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2546 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2552 i->peek_buf[0] = ch;
2553 /*i->peek_buf[1] = 0; - already is */
2557 /* Only ever called if i_peek() was called, and did not return EOF.
2558 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2559 * not end-of-line. Therefore we never need to read a new editing line here.
2561 static int i_peek2(struct in_str *i)
2565 /* There are two cases when i->p[] buffer exists.
2566 * (1) it's a string in_str.
2567 * (2) It's a file, and we have a saved line editing buffer.
2568 * In both cases, we know that i->p[0] exists and not NUL, and
2569 * the peek2 result is in i->p[1].
2572 return (unsigned char)i->p[1];
2574 /* Now we know it is a file-based in_str. */
2576 /* peek_buf[] is an int array, not char. Can contain EOF. */
2577 /* Is there 2nd char? */
2578 ch = i->peek_buf[1];
2580 /* We did not read it yet, get it now */
2581 do ch = fgetc(i->file); while (ch == '\0');
2582 i->peek_buf[1] = ch;
2585 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2589 static void setup_file_in_str(struct in_str *i, FILE *f)
2591 memset(i, 0, sizeof(*i));
2592 /* i->promptmode = 0; - PS1 (memset did it) */
2597 static void setup_string_in_str(struct in_str *i, const char *s)
2599 memset(i, 0, sizeof(*i));
2600 /* i->promptmode = 0; - PS1 (memset did it) */
2601 /*i->file = NULL */;
2609 #define B_CHUNK (32 * sizeof(char*))
2611 static void o_reset_to_empty_unquoted(o_string *o)
2614 o->has_quoted_part = 0;
2619 static void o_free(o_string *o)
2622 memset(o, 0, sizeof(*o));
2625 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2630 static void o_grow_by(o_string *o, int len)
2632 if (o->length + len > o->maxlen) {
2633 o->maxlen += (2 * len) | (B_CHUNK-1);
2634 o->data = xrealloc(o->data, 1 + o->maxlen);
2638 static void o_addchr(o_string *o, int ch)
2640 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2641 if (o->length < o->maxlen) {
2642 /* likely. avoid o_grow_by() call */
2644 o->data[o->length] = ch;
2646 o->data[o->length] = '\0';
2654 /* Valid only if we know o_string is not empty */
2655 static void o_delchr(o_string *o)
2658 o->data[o->length] = '\0';
2662 static void o_addblock(o_string *o, const char *str, int len)
2665 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2669 static void o_addstr(o_string *o, const char *str)
2671 o_addblock(o, str, strlen(str));
2675 static void nommu_addchr(o_string *o, int ch)
2681 # define nommu_addchr(o, str) ((void)0)
2684 static void o_addstr_with_NUL(o_string *o, const char *str)
2686 o_addblock(o, str, strlen(str) + 1);
2690 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2691 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2692 * Apparently, on unquoted $v bash still does globbing
2693 * ("v='*.txt'; echo $v" prints all .txt files),
2694 * but NOT brace expansion! Thus, there should be TWO independent
2695 * quoting mechanisms on $v expansion side: one protects
2696 * $v from brace expansion, and other additionally protects "$v" against globbing.
2697 * We have only second one.
2700 #if ENABLE_HUSH_BRACE_EXPANSION
2701 # define MAYBE_BRACES "{}"
2703 # define MAYBE_BRACES ""
2706 /* My analysis of quoting semantics tells me that state information
2707 * is associated with a destination, not a source.
2709 static void o_addqchr(o_string *o, int ch)
2712 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2717 o->data[o->length] = '\\';
2720 o->data[o->length] = ch;
2722 o->data[o->length] = '\0';
2725 static void o_addQchr(o_string *o, int ch)
2728 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2729 && strchr("*?[\\" MAYBE_BRACES, ch)
2732 o->data[o->length] = '\\';
2736 o->data[o->length] = ch;
2738 o->data[o->length] = '\0';
2741 static void o_addqblock(o_string *o, const char *str, int len)
2746 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2747 if (ordinary_cnt > len) /* paranoia */
2749 o_addblock(o, str, ordinary_cnt);
2750 if (ordinary_cnt == len)
2751 return; /* NUL is already added by o_addblock */
2752 str += ordinary_cnt;
2753 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2757 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2759 o->data[o->length] = '\\';
2763 o->data[o->length] = ch;
2766 o->data[o->length] = '\0';
2769 static void o_addQblock(o_string *o, const char *str, int len)
2771 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2772 o_addblock(o, str, len);
2775 o_addqblock(o, str, len);
2778 static void o_addQstr(o_string *o, const char *str)
2780 o_addQblock(o, str, strlen(str));
2783 /* A special kind of o_string for $VAR and `cmd` expansion.
2784 * It contains char* list[] at the beginning, which is grown in 16 element
2785 * increments. Actual string data starts at the next multiple of 16 * (char*).
2786 * list[i] contains an INDEX (int!) into this string data.
2787 * It means that if list[] needs to grow, data needs to be moved higher up
2788 * but list[i]'s need not be modified.
2789 * NB: remembering how many list[i]'s you have there is crucial.
2790 * o_finalize_list() operation post-processes this structure - calculates
2791 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2793 #if DEBUG_EXPAND || DEBUG_GLOB
2794 static void debug_print_list(const char *prefix, o_string *o, int n)
2796 char **list = (char**)o->data;
2797 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2801 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2802 prefix, list, n, string_start, o->length, o->maxlen,
2803 !!(o->o_expflags & EXP_FLAG_GLOB),
2805 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2808 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2809 o->data + (int)(uintptr_t)list[i] + string_start,
2810 o->data + (int)(uintptr_t)list[i] + string_start);
2814 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2816 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2820 # define debug_print_list(prefix, o, n) ((void)0)
2823 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2824 * in list[n] so that it points past last stored byte so far.
2825 * It returns n+1. */
2826 static int o_save_ptr_helper(o_string *o, int n)
2828 char **list = (char**)o->data;
2832 if (!o->has_empty_slot) {
2833 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2834 string_len = o->length - string_start;
2835 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2836 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2837 /* list[n] points to string_start, make space for 16 more pointers */
2838 o->maxlen += 0x10 * sizeof(list[0]);
2839 o->data = xrealloc(o->data, o->maxlen + 1);
2840 list = (char**)o->data;
2841 memmove(list + n + 0x10, list + n, string_len);
2842 o->length += 0x10 * sizeof(list[0]);
2844 debug_printf_list("list[%d]=%d string_start=%d\n",
2845 n, string_len, string_start);
2848 /* We have empty slot at list[n], reuse without growth */
2849 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2850 string_len = o->length - string_start;
2851 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2852 n, string_len, string_start);
2853 o->has_empty_slot = 0;
2855 o->has_quoted_part = 0;
2856 list[n] = (char*)(uintptr_t)string_len;
2860 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2861 static int o_get_last_ptr(o_string *o, int n)
2863 char **list = (char**)o->data;
2864 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2866 return ((int)(uintptr_t)list[n-1]) + string_start;
2869 #if ENABLE_HUSH_BRACE_EXPANSION
2870 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2871 * first, it processes even {a} (no commas), second,
2872 * I didn't manage to make it return strings when they don't match
2873 * existing files. Need to re-implement it.
2877 static int glob_needed(const char *s)
2886 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2892 /* Return pointer to next closing brace or to comma */
2893 static const char *next_brace_sub(const char *cp)
2897 while (*cp != '\0') {
2904 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2910 return *cp != '\0' ? cp : NULL;
2912 /* Recursive brace globber. Note: may garble pattern[]. */
2913 static int glob_brace(char *pattern, o_string *o, int n)
2915 char *new_pattern_buf;
2922 debug_printf_glob("glob_brace('%s')\n", pattern);
2928 if (*begin == '{') {
2929 /* Find the first sub-pattern and at the same time
2930 * find the rest after the closing brace */
2931 next = next_brace_sub(begin);
2933 /* An illegal expression */
2937 /* "{abc}" with no commas - illegal
2938 * brace expr, disregard and skip it */
2944 if (*begin == '\\' && begin[1] != '\0')
2948 debug_printf_glob("begin:%s\n", begin);
2949 debug_printf_glob("next:%s\n", next);
2951 /* Now find the end of the whole brace expression */
2953 while (*rest != '}') {
2954 rest = next_brace_sub(rest);
2956 /* An illegal expression */
2959 debug_printf_glob("rest:%s\n", rest);
2961 rest_len = strlen(++rest) + 1;
2963 /* We are sure the brace expression is well-formed */
2965 /* Allocate working buffer large enough for our work */
2966 new_pattern_buf = xmalloc(strlen(pattern));
2968 /* We have a brace expression. BEGIN points to the opening {,
2969 * NEXT points past the terminator of the first element, and REST
2970 * points past the final }. We will accumulate result names from
2971 * recursive runs for each brace alternative in the buffer using
2976 /* Construct the new glob expression */
2979 mempcpy(new_pattern_buf,
2980 /* We know the prefix for all sub-patterns */
2981 pattern, begin - pattern),
2985 /* Note: glob_brace() may garble new_pattern_buf[].
2986 * That's why we re-copy prefix every time (1st memcpy above).
2988 n = glob_brace(new_pattern_buf, o, n);
2990 /* We saw the last entry */
2994 next = next_brace_sub(next);
2996 free(new_pattern_buf);
3004 memset(&globdata, 0, sizeof(globdata));
3005 gr = glob(pattern, 0, NULL, &globdata);
3006 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3008 if (gr == GLOB_NOMATCH) {
3009 globfree(&globdata);
3010 /* NB: garbles parameter */
3011 unbackslash(pattern);
3012 o_addstr_with_NUL(o, pattern);
3013 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3014 return o_save_ptr_helper(o, n);
3016 if (gr == GLOB_NOSPACE)
3017 bb_error_msg_and_die(bb_msg_memory_exhausted);
3018 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3019 * but we didn't specify it. Paranoia again. */
3020 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3022 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3023 char **argv = globdata.gl_pathv;
3025 o_addstr_with_NUL(o, *argv);
3026 n = o_save_ptr_helper(o, n);
3032 globfree(&globdata);
3036 /* Performs globbing on last list[],
3037 * saving each result as a new list[].
3039 static int perform_glob(o_string *o, int n)
3041 char *pattern, *copy;
3043 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3045 return o_save_ptr_helper(o, n);
3046 pattern = o->data + o_get_last_ptr(o, n);
3047 debug_printf_glob("glob pattern '%s'\n", pattern);
3048 if (!glob_needed(pattern)) {
3049 /* unbackslash last string in o in place, fix length */
3050 o->length = unbackslash(pattern) - o->data;
3051 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3052 return o_save_ptr_helper(o, n);
3055 copy = xstrdup(pattern);
3056 /* "forget" pattern in o */
3057 o->length = pattern - o->data;
3058 n = glob_brace(copy, o, n);
3061 debug_print_list("perform_glob returning", o, n);
3065 #else /* !HUSH_BRACE_EXPANSION */
3068 static int glob_needed(const char *s)
3077 if (*s == '*' || *s == '[' || *s == '?')
3083 /* Performs globbing on last list[],
3084 * saving each result as a new list[].
3086 static int perform_glob(o_string *o, int n)
3092 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3094 return o_save_ptr_helper(o, n);
3095 pattern = o->data + o_get_last_ptr(o, n);
3096 debug_printf_glob("glob pattern '%s'\n", pattern);
3097 if (!glob_needed(pattern)) {
3099 /* unbackslash last string in o in place, fix length */
3100 o->length = unbackslash(pattern) - o->data;
3101 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3102 return o_save_ptr_helper(o, n);
3105 memset(&globdata, 0, sizeof(globdata));
3106 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3107 * If we glob "*.\*" and don't find anything, we need
3108 * to fall back to using literal "*.*", but GLOB_NOCHECK
3109 * will return "*.\*"!
3111 gr = glob(pattern, 0, NULL, &globdata);
3112 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3114 if (gr == GLOB_NOMATCH) {
3115 globfree(&globdata);
3118 if (gr == GLOB_NOSPACE)
3119 bb_error_msg_and_die(bb_msg_memory_exhausted);
3120 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3121 * but we didn't specify it. Paranoia again. */
3122 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3124 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3125 char **argv = globdata.gl_pathv;
3126 /* "forget" pattern in o */
3127 o->length = pattern - o->data;
3129 o_addstr_with_NUL(o, *argv);
3130 n = o_save_ptr_helper(o, n);
3136 globfree(&globdata);
3138 debug_print_list("perform_glob returning", o, n);
3142 #endif /* !HUSH_BRACE_EXPANSION */
3144 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3145 * Otherwise, just finish current list[] and start new */
3146 static int o_save_ptr(o_string *o, int n)
3148 if (o->o_expflags & EXP_FLAG_GLOB) {
3149 /* If o->has_empty_slot, list[n] was already globbed
3150 * (if it was requested back then when it was filled)
3151 * so don't do that again! */
3152 if (!o->has_empty_slot)
3153 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3155 return o_save_ptr_helper(o, n);
3158 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3159 static char **o_finalize_list(o_string *o, int n)
3164 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3166 debug_print_list("finalized", o, n);
3167 debug_printf_expand("finalized n:%d\n", n);
3168 list = (char**)o->data;
3169 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3173 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3178 static void free_pipe_list(struct pipe *pi);
3180 /* Returns pi->next - next pipe in the list */
3181 static struct pipe *free_pipe(struct pipe *pi)
3186 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3187 for (i = 0; i < pi->num_cmds; i++) {
3188 struct command *command;
3189 struct redir_struct *r, *rnext;
3191 command = &pi->cmds[i];
3192 debug_printf_clean(" command %d:\n", i);
3193 if (command->argv) {
3197 for (a = 0, p = command->argv; *p; a++, p++) {
3198 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3201 free_strings(command->argv);
3202 //command->argv = NULL;
3204 /* not "else if": on syntax error, we may have both! */
3205 if (command->group) {
3206 debug_printf_clean(" begin group (cmd_type:%d)\n",
3208 free_pipe_list(command->group);
3209 debug_printf_clean(" end group\n");
3210 //command->group = NULL;
3212 /* else is crucial here.
3213 * If group != NULL, child_func is meaningless */
3214 #if ENABLE_HUSH_FUNCTIONS
3215 else if (command->child_func) {
3216 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3217 command->child_func->parent_cmd = NULL;
3221 free(command->group_as_string);
3222 //command->group_as_string = NULL;
3224 for (r = command->redirects; r; r = rnext) {
3225 debug_printf_clean(" redirect %d%s",
3226 r->rd_fd, redir_table[r->rd_type].descrip);
3227 /* guard against the case >$FOO, where foo is unset or blank */
3228 if (r->rd_filename) {
3229 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3230 free(r->rd_filename);
3231 //r->rd_filename = NULL;
3233 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3237 //command->redirects = NULL;
3239 free(pi->cmds); /* children are an array, they get freed all at once */
3243 //pi->cmdtext = NULL;
3251 static void free_pipe_list(struct pipe *pi)
3255 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3257 debug_printf_clean("pipe followup code %d\n", pi->followup);
3263 /*** Parsing routines ***/
3265 #ifndef debug_print_tree
3266 static void debug_print_tree(struct pipe *pi, int lvl)
3268 static const char *const PIPE[] = {
3274 static const char *RES[] = {
3275 [RES_NONE ] = "NONE" ,
3278 [RES_THEN ] = "THEN" ,
3279 [RES_ELIF ] = "ELIF" ,
3280 [RES_ELSE ] = "ELSE" ,
3283 # if ENABLE_HUSH_LOOPS
3284 [RES_FOR ] = "FOR" ,
3285 [RES_WHILE] = "WHILE",
3286 [RES_UNTIL] = "UNTIL",
3288 [RES_DONE ] = "DONE" ,
3290 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3293 # if ENABLE_HUSH_CASE
3294 [RES_CASE ] = "CASE" ,
3295 [RES_CASE_IN ] = "CASE_IN" ,
3296 [RES_MATCH] = "MATCH",
3297 [RES_CASE_BODY] = "CASE_BODY",
3298 [RES_ESAC ] = "ESAC" ,
3300 [RES_XXXX ] = "XXXX" ,
3301 [RES_SNTX ] = "SNTX" ,
3303 static const char *const CMDTYPE[] = {
3307 # if ENABLE_HUSH_FUNCTIONS
3316 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3317 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3319 while (prn < pi->num_cmds) {
3320 struct command *command = &pi->cmds[prn];
3321 char **argv = command->argv;
3323 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3325 command->assignment_cnt);
3326 if (command->group) {
3327 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3328 CMDTYPE[command->cmd_type],
3331 , " group_as_string:", command->group_as_string
3336 debug_print_tree(command->group, lvl+1);
3340 if (argv) while (*argv) {
3341 fdprintf(2, " '%s'", *argv);
3351 #endif /* debug_print_tree */
3353 static struct pipe *new_pipe(void)
3356 pi = xzalloc(sizeof(struct pipe));
3357 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3361 /* Command (member of a pipe) is complete, or we start a new pipe
3362 * if ctx->command is NULL.
3363 * No errors possible here.
3365 static int done_command(struct parse_context *ctx)
3367 /* The command is really already in the pipe structure, so
3368 * advance the pipe counter and make a new, null command. */
3369 struct pipe *pi = ctx->pipe;
3370 struct command *command = ctx->command;
3372 #if 0 /* Instead we emit error message at run time */
3373 if (ctx->pending_redirect) {
3374 /* For example, "cmd >" (no filename to redirect to) */
3375 die_if_script("syntax error: %s", "invalid redirect");
3376 ctx->pending_redirect = NULL;
3381 if (IS_NULL_CMD(command)) {
3382 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3386 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3387 //debug_print_tree(ctx->list_head, 20);
3389 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3392 /* Only real trickiness here is that the uncommitted
3393 * command structure is not counted in pi->num_cmds. */
3394 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3395 ctx->command = command = &pi->cmds[pi->num_cmds];
3397 memset(command, 0, sizeof(*command));
3398 return pi->num_cmds; /* used only for 0/nonzero check */
3401 static void done_pipe(struct parse_context *ctx, pipe_style type)
3405 debug_printf_parse("done_pipe entered, followup %d\n", type);
3406 /* Close previous command */
3407 not_null = done_command(ctx);
3409 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3410 ctx->ctx_inverted = 0;
3411 ctx->pipe->res_word = ctx->ctx_res_w;
3413 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3414 /* Necessary since && and || have precedence over &:
3415 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3416 * in a backgrounded subshell.
3419 struct command *command;
3421 /* Is this actually this construct, all pipes end with && or ||? */
3422 pi = ctx->list_head;
3423 while (pi != ctx->pipe) {
3424 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3429 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3430 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3431 pi = xzalloc(sizeof(*pi));
3432 pi->followup = PIPE_BG;
3434 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3435 command = &pi->cmds[0];
3436 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3437 command->cmd_type = CMD_NORMAL;
3438 command->group = ctx->list_head;
3440 command->group_as_string = xstrndup(
3441 ctx->as_string.data,
3442 ctx->as_string.length - 1 /* do not copy last char, "&" */
3445 /* Replace all pipes in ctx with one newly created */
3446 ctx->list_head = ctx->pipe = pi;
3449 ctx->pipe->followup = type;
3452 /* Without this check, even just <enter> on command line generates
3453 * tree of three NOPs (!). Which is harmless but annoying.
3454 * IOW: it is safe to do it unconditionally. */
3457 || ctx->ctx_res_w == RES_FI
3459 #if ENABLE_HUSH_LOOPS
3460 || ctx->ctx_res_w == RES_DONE
3461 || ctx->ctx_res_w == RES_FOR
3462 || ctx->ctx_res_w == RES_IN
3464 #if ENABLE_HUSH_CASE
3465 || ctx->ctx_res_w == RES_ESAC
3469 debug_printf_parse("done_pipe: adding new pipe: "
3470 "not_null:%d ctx->ctx_res_w:%d\n",
3471 not_null, ctx->ctx_res_w);
3473 ctx->pipe->next = new_p;
3475 /* RES_THEN, RES_DO etc are "sticky" -
3476 * they remain set for pipes inside if/while.
3477 * This is used to control execution.
3478 * RES_FOR and RES_IN are NOT sticky (needed to support
3479 * cases where variable or value happens to match a keyword):
3481 #if ENABLE_HUSH_LOOPS
3482 if (ctx->ctx_res_w == RES_FOR
3483 || ctx->ctx_res_w == RES_IN)
3484 ctx->ctx_res_w = RES_NONE;
3486 #if ENABLE_HUSH_CASE
3487 if (ctx->ctx_res_w == RES_MATCH)
3488 ctx->ctx_res_w = RES_CASE_BODY;
3489 if (ctx->ctx_res_w == RES_CASE)
3490 ctx->ctx_res_w = RES_CASE_IN;
3492 ctx->command = NULL; /* trick done_command below */
3493 /* Create the memory for command, roughly:
3494 * ctx->pipe->cmds = new struct command;
3495 * ctx->command = &ctx->pipe->cmds[0];
3498 //debug_print_tree(ctx->list_head, 10);
3500 debug_printf_parse("done_pipe return\n");
3503 static void initialize_context(struct parse_context *ctx)
3505 memset(ctx, 0, sizeof(*ctx));
3506 ctx->pipe = ctx->list_head = new_pipe();
3507 /* Create the memory for command, roughly:
3508 * ctx->pipe->cmds = new struct command;
3509 * ctx->command = &ctx->pipe->cmds[0];
3514 /* If a reserved word is found and processed, parse context is modified
3515 * and 1 is returned.
3518 struct reserved_combo {
3521 unsigned char assignment_flag;
3525 FLAG_END = (1 << RES_NONE ),
3527 FLAG_IF = (1 << RES_IF ),
3528 FLAG_THEN = (1 << RES_THEN ),
3529 FLAG_ELIF = (1 << RES_ELIF ),
3530 FLAG_ELSE = (1 << RES_ELSE ),
3531 FLAG_FI = (1 << RES_FI ),
3533 # if ENABLE_HUSH_LOOPS
3534 FLAG_FOR = (1 << RES_FOR ),
3535 FLAG_WHILE = (1 << RES_WHILE),
3536 FLAG_UNTIL = (1 << RES_UNTIL),
3537 FLAG_DO = (1 << RES_DO ),
3538 FLAG_DONE = (1 << RES_DONE ),
3539 FLAG_IN = (1 << RES_IN ),
3541 # if ENABLE_HUSH_CASE
3542 FLAG_MATCH = (1 << RES_MATCH),
3543 FLAG_ESAC = (1 << RES_ESAC ),
3545 FLAG_START = (1 << RES_XXXX ),
3548 static const struct reserved_combo* match_reserved_word(o_string *word)
3550 /* Mostly a list of accepted follow-up reserved words.
3551 * FLAG_END means we are done with the sequence, and are ready
3552 * to turn the compound list into a command.
3553 * FLAG_START means the word must start a new compound list.
3555 static const struct reserved_combo reserved_list[] = {
3557 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3558 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3559 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3560 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3561 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3562 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3564 # if ENABLE_HUSH_LOOPS
3565 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3566 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3567 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3568 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3569 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3570 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3572 # if ENABLE_HUSH_CASE
3573 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3574 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3577 const struct reserved_combo *r;
3579 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3580 if (strcmp(word->data, r->literal) == 0)
3585 /* Return 0: not a keyword, 1: keyword
3587 static int reserved_word(o_string *word, struct parse_context *ctx)
3589 # if ENABLE_HUSH_CASE
3590 static const struct reserved_combo reserved_match = {
3591 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3594 const struct reserved_combo *r;
3596 if (word->has_quoted_part)
3598 r = match_reserved_word(word);
3602 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3603 # if ENABLE_HUSH_CASE
3604 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3605 /* "case word IN ..." - IN part starts first MATCH part */
3606 r = &reserved_match;
3609 if (r->flag == 0) { /* '!' */
3610 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3611 syntax_error("! ! command");
3612 ctx->ctx_res_w = RES_SNTX;
3614 ctx->ctx_inverted = 1;
3617 if (r->flag & FLAG_START) {
3618 struct parse_context *old;
3620 old = xmemdup(ctx, sizeof(*ctx));
3621 debug_printf_parse("push stack %p\n", old);
3622 initialize_context(ctx);
3624 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3625 syntax_error_at(word->data);
3626 ctx->ctx_res_w = RES_SNTX;
3629 /* "{...} fi" is ok. "{...} if" is not
3631 * if { echo foo; } then { echo bar; } fi */
3632 if (ctx->command->group)
3633 done_pipe(ctx, PIPE_SEQ);
3636 ctx->ctx_res_w = r->res;
3637 ctx->old_flag = r->flag;
3638 word->o_assignment = r->assignment_flag;
3639 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3641 if (ctx->old_flag & FLAG_END) {
3642 struct parse_context *old;
3644 done_pipe(ctx, PIPE_SEQ);
3645 debug_printf_parse("pop stack %p\n", ctx->stack);
3647 old->command->group = ctx->list_head;
3648 old->command->cmd_type = CMD_NORMAL;
3650 /* At this point, the compound command's string is in
3651 * ctx->as_string... except for the leading keyword!
3652 * Consider this example: "echo a | if true; then echo a; fi"
3653 * ctx->as_string will contain "true; then echo a; fi",
3654 * with "if " remaining in old->as_string!
3658 int len = old->as_string.length;
3659 /* Concatenate halves */
3660 o_addstr(&old->as_string, ctx->as_string.data);
3661 o_free_unsafe(&ctx->as_string);
3662 /* Find where leading keyword starts in first half */
3663 str = old->as_string.data + len;
3664 if (str > old->as_string.data)
3665 str--; /* skip whitespace after keyword */
3666 while (str > old->as_string.data && isalpha(str[-1]))
3668 /* Ugh, we're done with this horrid hack */
3669 old->command->group_as_string = xstrdup(str);
3670 debug_printf_parse("pop, remembering as:'%s'\n",
3671 old->command->group_as_string);
3674 *ctx = *old; /* physical copy */
3679 #endif /* HAS_KEYWORDS */
3681 /* Word is complete, look at it and update parsing context.
3682 * Normal return is 0. Syntax errors return 1.
3683 * Note: on return, word is reset, but not o_free'd!
3685 static int done_word(o_string *word, struct parse_context *ctx)
3687 struct command *command = ctx->command;
3689 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3690 if (word->length == 0 && !word->has_quoted_part) {
3691 debug_printf_parse("done_word return 0: true null, ignored\n");
3695 if (ctx->pending_redirect) {
3696 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3697 * only if run as "bash", not "sh" */
3698 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3700 * ...the word that follows the redirection operator
3701 * shall be subjected to tilde expansion, parameter expansion,
3702 * command substitution, arithmetic expansion, and quote
3703 * removal. Pathname expansion shall not be performed
3704 * on the word by a non-interactive shell; an interactive
3705 * shell may perform it, but shall do so only when
3706 * the expansion would result in one word."
3708 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3709 /* Cater for >\file case:
3710 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3711 * Same with heredocs:
3712 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3714 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3715 unbackslash(ctx->pending_redirect->rd_filename);
3716 /* Is it <<"HEREDOC"? */
3717 if (word->has_quoted_part) {
3718 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3721 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3722 ctx->pending_redirect = NULL;
3725 # if ENABLE_HUSH_CASE
3726 if (ctx->ctx_dsemicolon
3727 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3729 /* already done when ctx_dsemicolon was set to 1: */
3730 /* ctx->ctx_res_w = RES_MATCH; */
3731 ctx->ctx_dsemicolon = 0;
3734 if (!command->argv /* if it's the first word... */
3735 # if ENABLE_HUSH_LOOPS
3736 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3737 && ctx->ctx_res_w != RES_IN
3739 # if ENABLE_HUSH_CASE
3740 && ctx->ctx_res_w != RES_CASE
3743 int reserved = reserved_word(word, ctx);
3744 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3746 o_reset_to_empty_unquoted(word);
3747 debug_printf_parse("done_word return %d\n",
3748 (ctx->ctx_res_w == RES_SNTX));
3749 return (ctx->ctx_res_w == RES_SNTX);
3752 if (strcmp(word->data, "[[") == 0) {
3753 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3759 if (command->group) {
3760 /* "{ echo foo; } echo bar" - bad */
3761 syntax_error_at(word->data);
3762 debug_printf_parse("done_word return 1: syntax error, "
3763 "groups and arglists don't mix\n");
3767 /* If this word wasn't an assignment, next ones definitely
3768 * can't be assignments. Even if they look like ones. */
3769 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3770 && word->o_assignment != WORD_IS_KEYWORD
3772 word->o_assignment = NOT_ASSIGNMENT;
3774 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3775 command->assignment_cnt++;
3776 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3778 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3779 word->o_assignment = MAYBE_ASSIGNMENT;
3781 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3783 if (word->has_quoted_part
3784 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3785 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3786 /* (otherwise it's known to be not empty and is already safe) */
3788 /* exclude "$@" - it can expand to no word despite "" */
3789 char *p = word->data;
3790 while (p[0] == SPECIAL_VAR_SYMBOL
3791 && (p[1] & 0x7f) == '@'
3792 && p[2] == SPECIAL_VAR_SYMBOL
3797 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3798 debug_print_strings("word appended to argv", command->argv);
3801 #if ENABLE_HUSH_LOOPS
3802 if (ctx->ctx_res_w == RES_FOR) {
3803 if (word->has_quoted_part
3804 || !is_well_formed_var_name(command->argv[0], '\0')
3806 /* bash says just "not a valid identifier" */
3807 syntax_error("not a valid identifier in for");
3810 /* Force FOR to have just one word (variable name) */
3811 /* NB: basically, this makes hush see "for v in ..."
3812 * syntax as if it is "for v; in ...". FOR and IN become
3813 * two pipe structs in parse tree. */
3814 done_pipe(ctx, PIPE_SEQ);
3817 #if ENABLE_HUSH_CASE
3818 /* Force CASE to have just one word */
3819 if (ctx->ctx_res_w == RES_CASE) {
3820 done_pipe(ctx, PIPE_SEQ);
3824 o_reset_to_empty_unquoted(word);
3826 debug_printf_parse("done_word return 0\n");
3831 /* Peek ahead in the input to find out if we have a "&n" construct,
3832 * as in "2>&1", that represents duplicating a file descriptor.
3834 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3835 * REDIRFD_SYNTAX_ERR if syntax error,
3836 * REDIRFD_TO_FILE if no & was seen,
3837 * or the number found.
3840 #define parse_redir_right_fd(as_string, input) \
3841 parse_redir_right_fd(input)
3843 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3849 return REDIRFD_TO_FILE;
3851 ch = i_getch(input); /* get the & */
3852 nommu_addchr(as_string, ch);
3855 ch = i_getch(input);
3856 nommu_addchr(as_string, ch);
3857 return REDIRFD_CLOSE;
3861 while (ch != EOF && isdigit(ch)) {
3862 d = d*10 + (ch-'0');
3864 ch = i_getch(input);
3865 nommu_addchr(as_string, ch);
3870 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3872 bb_error_msg("ambiguous redirect");
3873 return REDIRFD_SYNTAX_ERR;
3876 /* Return code is 0 normal, 1 if a syntax error is detected
3878 static int parse_redirect(struct parse_context *ctx,
3881 struct in_str *input)
3883 struct command *command = ctx->command;
3884 struct redir_struct *redir;
3885 struct redir_struct **redirp;
3888 dup_num = REDIRFD_TO_FILE;
3889 if (style != REDIRECT_HEREDOC) {
3890 /* Check for a '>&1' type redirect */
3891 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3892 if (dup_num == REDIRFD_SYNTAX_ERR)
3895 int ch = i_peek(input);
3896 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3897 if (dup_num) { /* <<-... */
3898 ch = i_getch(input);
3899 nommu_addchr(&ctx->as_string, ch);
3904 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3905 int ch = i_peek(input);
3907 /* >|FILE redirect ("clobbering" >).
3908 * Since we do not support "set -o noclobber" yet,
3909 * >| and > are the same for now. Just eat |.
3911 ch = i_getch(input);
3912 nommu_addchr(&ctx->as_string, ch);
3916 /* Create a new redir_struct and append it to the linked list */
3917 redirp = &command->redirects;
3918 while ((redir = *redirp) != NULL) {
3919 redirp = &(redir->next);
3921 *redirp = redir = xzalloc(sizeof(*redir));
3922 /* redir->next = NULL; */
3923 /* redir->rd_filename = NULL; */
3924 redir->rd_type = style;
3925 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3927 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3928 redir_table[style].descrip);
3930 redir->rd_dup = dup_num;
3931 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3932 /* Erik had a check here that the file descriptor in question
3933 * is legit; I postpone that to "run time"
3934 * A "-" representation of "close me" shows up as a -3 here */
3935 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3936 redir->rd_fd, redir->rd_dup);
3938 #if 0 /* Instead we emit error message at run time */
3939 if (ctx->pending_redirect) {
3940 /* For example, "cmd > <file" */
3941 die_if_script("syntax error: %s", "invalid redirect");
3944 /* Set ctx->pending_redirect, so we know what to do at the
3945 * end of the next parsed word. */
3946 ctx->pending_redirect = redir;
3951 /* If a redirect is immediately preceded by a number, that number is
3952 * supposed to tell which file descriptor to redirect. This routine
3953 * looks for such preceding numbers. In an ideal world this routine
3954 * needs to handle all the following classes of redirects...
3955 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3956 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3957 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3958 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3960 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3962 * ... If n is quoted, the number shall not be recognized as part of
3963 * the redirection expression. For example:
3965 * writes the character 2 into file a"
3966 * We are getting it right by setting ->has_quoted_part on any \<char>
3968 * A -1 return means no valid number was found,
3969 * the caller should use the appropriate default for this redirection.
3971 static int redirect_opt_num(o_string *o)
3975 if (o->data == NULL)
3977 num = bb_strtou(o->data, NULL, 10);
3978 if (errno || num < 0)
3980 o_reset_to_empty_unquoted(o);
3985 #define fetch_till_str(as_string, input, word, skip_tabs) \
3986 fetch_till_str(input, word, skip_tabs)
3988 static char *fetch_till_str(o_string *as_string,
3989 struct in_str *input,
3993 o_string heredoc = NULL_O_STRING;
3995 int prev = 0; /* not \ */
4001 ch = i_getch(input);
4003 nommu_addchr(as_string, ch);
4004 if (ch == '\n' || ch == EOF) {
4006 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4007 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4008 heredoc.data[past_EOL] = '\0';
4009 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4010 return heredoc.data;
4013 /* This is a new line.
4014 * Remember position and backslash-escaping status.
4016 o_addchr(&heredoc, ch);
4019 past_EOL = heredoc.length;
4020 /* Get 1st char of next line, possibly skipping leading tabs */
4022 ch = i_getch(input);
4024 nommu_addchr(as_string, ch);
4025 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4026 /* If this immediately ended the line,
4027 * go back to end-of-line checks.
4030 goto check_heredoc_end;
4035 o_free_unsafe(&heredoc);
4038 o_addchr(&heredoc, ch);
4039 nommu_addchr(as_string, ch);
4040 if (prev == '\\' && ch == '\\')
4041 /* Correctly handle foo\\<eol> (not a line cont.) */
4042 prev = 0; /* not \ */
4048 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4049 * and load them all. There should be exactly heredoc_cnt of them.
4051 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4053 struct pipe *pi = ctx->list_head;
4055 while (pi && heredoc_cnt) {
4057 struct command *cmd = pi->cmds;
4059 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4061 cmd->argv ? cmd->argv[0] : "NONE");
4062 for (i = 0; i < pi->num_cmds; i++) {
4063 struct redir_struct *redir = cmd->redirects;
4065 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4066 i, cmd->argv ? cmd->argv[0] : "NONE");
4068 if (redir->rd_type == REDIRECT_HEREDOC) {
4071 redir->rd_type = REDIRECT_HEREDOC2;
4072 /* redir->rd_dup is (ab)used to indicate <<- */
4073 p = fetch_till_str(&ctx->as_string, input,
4074 redir->rd_filename, redir->rd_dup);
4076 syntax_error("unexpected EOF in here document");
4079 free(redir->rd_filename);
4080 redir->rd_filename = p;
4083 redir = redir->next;
4090 /* Should be 0. If it isn't, it's a parse error */
4092 bb_error_msg_and_die("heredoc BUG 2");
4098 static int run_list(struct pipe *pi);
4100 #define parse_stream(pstring, input, end_trigger) \
4101 parse_stream(input, end_trigger)
4103 static struct pipe *parse_stream(char **pstring,
4104 struct in_str *input,
4108 #if !ENABLE_HUSH_FUNCTIONS
4109 #define parse_group(dest, ctx, input, ch) \
4110 parse_group(ctx, input, ch)
4112 static int parse_group(o_string *dest, struct parse_context *ctx,
4113 struct in_str *input, int ch)
4115 /* dest contains characters seen prior to ( or {.
4116 * Typically it's empty, but for function defs,
4117 * it contains function name (without '()'). */
4118 struct pipe *pipe_list;
4120 struct command *command = ctx->command;
4122 debug_printf_parse("parse_group entered\n");
4123 #if ENABLE_HUSH_FUNCTIONS
4124 if (ch == '(' && !dest->has_quoted_part) {
4126 if (done_word(dest, ctx))
4129 goto skip; /* (... */
4130 if (command->argv[1]) { /* word word ... (... */
4131 syntax_error_unexpected_ch('(');
4134 /* it is "word(..." or "word (..." */
4136 ch = i_getch(input);
4137 while (ch == ' ' || ch == '\t');
4139 syntax_error_unexpected_ch(ch);
4142 nommu_addchr(&ctx->as_string, ch);
4144 ch = i_getch(input);
4145 while (ch == ' ' || ch == '\t' || ch == '\n');
4147 syntax_error_unexpected_ch(ch);
4150 nommu_addchr(&ctx->as_string, ch);
4151 command->cmd_type = CMD_FUNCDEF;
4156 #if 0 /* Prevented by caller */
4157 if (command->argv /* word [word]{... */
4158 || dest->length /* word{... */
4159 || dest->has_quoted_part /* ""{... */
4162 debug_printf_parse("parse_group return 1: "
4163 "syntax error, groups and arglists don't mix\n");
4168 #if ENABLE_HUSH_FUNCTIONS
4174 command->cmd_type = CMD_SUBSHELL;
4176 /* bash does not allow "{echo...", requires whitespace */
4178 if (ch != ' ' && ch != '\t' && ch != '\n'
4179 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4181 syntax_error_unexpected_ch(ch);
4185 ch = i_getch(input);
4186 nommu_addchr(&ctx->as_string, ch);
4192 # define as_string NULL
4194 char *as_string = NULL;
4196 pipe_list = parse_stream(&as_string, input, endch);
4199 o_addstr(&ctx->as_string, as_string);
4201 /* empty ()/{} or parse error? */
4202 if (!pipe_list || pipe_list == ERR_PTR) {
4203 /* parse_stream already emitted error msg */
4206 debug_printf_parse("parse_group return 1: "
4207 "parse_stream returned %p\n", pipe_list);
4210 command->group = pipe_list;
4212 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4213 command->group_as_string = as_string;
4214 debug_printf_parse("end of group, remembering as:'%s'\n",
4215 command->group_as_string);
4219 debug_printf_parse("parse_group return 0\n");
4221 /* command remains "open", available for possible redirects */
4224 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4229 ch = i_getch(input);
4232 ch2 = i_peek(input);
4235 /* backslash+newline, skip it */
4240 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4248 ch2 = i_peek2(input);
4251 /* backslash+newline, skip it */
4257 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4258 /* Subroutines for copying $(...) and `...` things */
4259 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4261 static int add_till_single_quote(o_string *dest, struct in_str *input)
4264 int ch = i_getch(input);
4266 syntax_error_unterm_ch('\'');
4274 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4275 static int add_till_double_quote(o_string *dest, struct in_str *input)
4278 int ch = i_getch(input);
4280 syntax_error_unterm_ch('"');
4285 if (ch == '\\') { /* \x. Copy both chars. */
4287 ch = i_getch(input);
4291 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4296 //if (ch == '$') ...
4299 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4301 * "Within the backquoted style of command substitution, backslash
4302 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4303 * The search for the matching backquote shall be satisfied by the first
4304 * backquote found without a preceding backslash; during this search,
4305 * if a non-escaped backquote is encountered within a shell comment,
4306 * a here-document, an embedded command substitution of the $(command)
4307 * form, or a quoted string, undefined results occur. A single-quoted
4308 * or double-quoted string that begins, but does not end, within the
4309 * "`...`" sequence produces undefined results."
4311 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4313 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4316 int ch = i_getch(input);
4320 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4321 ch = i_getch(input);
4325 && (!in_dquote || ch != '"')
4327 o_addchr(dest, '\\');
4331 syntax_error_unterm_ch('`');
4337 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4338 * quoting and nested ()s.
4339 * "With the $(command) style of command substitution, all characters
4340 * following the open parenthesis to the matching closing parenthesis
4341 * constitute the command. Any valid shell script can be used for command,
4342 * except a script consisting solely of redirections which produces
4343 * unspecified results."
4345 * echo $(echo '(TEST)' BEST) (TEST) BEST
4346 * echo $(echo 'TEST)' BEST) TEST) BEST
4347 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4349 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4350 * can contain arbitrary constructs, just like $(cmd).
4351 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4352 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4354 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4355 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4358 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4359 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4360 char end_char2 = end_ch >> 8;
4362 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4365 ch = i_getch(input);
4367 syntax_error_unterm_ch(end_ch);
4371 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4377 /* we look for closing )) of $((EXPR)) */
4378 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4379 i_getch(input); /* eat second ')' */
4384 if (ch == '(' || ch == '{') {
4385 ch = (ch == '(' ? ')' : '}');
4386 if (!add_till_closing_bracket(dest, input, ch))
4392 if (!add_till_single_quote(dest, input))
4398 if (!add_till_double_quote(dest, input))
4404 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4410 /* \x. Copy verbatim. Important for \(, \) */
4411 ch = i_getch(input);
4413 syntax_error_unterm_ch(')');
4418 /* "backslash+newline", ignore both */
4419 o_delchr(dest); /* undo insertion of '\' */
4429 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4431 /* Return code: 0 for OK, 1 for syntax error */
4433 #define parse_dollar(as_string, dest, input, quote_mask) \
4434 parse_dollar(dest, input, quote_mask)
4435 #define as_string NULL
4437 static int parse_dollar(o_string *as_string,
4439 struct in_str *input, unsigned char quote_mask)
4441 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4443 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4445 ch = i_getch(input);
4446 nommu_addchr(as_string, ch);
4448 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4450 debug_printf_parse(": '%c'\n", ch);
4451 o_addchr(dest, ch | quote_mask);
4453 ch = i_peek_and_eat_bkslash_nl(input);
4454 if (!isalnum(ch) && ch != '_') {
4455 /* End of variable name reached */
4458 ch = i_getch(input);
4459 nommu_addchr(as_string, ch);
4461 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4462 } else if (isdigit(ch)) {
4464 ch = i_getch(input);
4465 nommu_addchr(as_string, ch);
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 debug_printf_parse(": '%c'\n", ch);
4468 o_addchr(dest, ch | quote_mask);
4469 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4470 } else switch (ch) {
4472 case '!': /* last bg pid */
4473 case '?': /* last exit code */
4474 case '#': /* number of args */
4475 case '*': /* args */
4476 case '@': /* args */
4477 goto make_one_char_var;
4481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4483 ch = i_getch(input); /* eat '{' */
4484 nommu_addchr(as_string, ch);
4486 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4487 /* It should be ${?}, or ${#var},
4488 * or even ${?+subst} - operator acting on a special variable,
4489 * or the beginning of variable name.
4492 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4495 syntax_error_unterm_str("${name}");
4496 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4499 nommu_addchr(as_string, ch);
4503 /* It's possible to just call add_till_closing_bracket() at this point.
4504 * However, this regresses some of our testsuite cases
4505 * which check invalid constructs like ${%}.
4506 * Oh well... let's check that the var name part is fine... */
4512 debug_printf_parse(": '%c'\n", ch);
4514 ch = i_getch(input);
4515 nommu_addchr(as_string, ch);
4519 if (!isalnum(ch) && ch != '_') {
4521 unsigned char last_ch;
4522 /* handle parameter expansions
4523 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4525 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4526 if (len_single_ch != '#'
4527 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4528 || i_peek(input) != '}'
4530 goto bad_dollar_syntax;
4532 /* else: it's "length of C" ${#C} op,
4533 * where C is a single char
4534 * special var name, e.g. ${#!}.
4537 /* Eat everything until closing '}' (or ':') */
4541 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4543 /* It's ${var:N[:M]} thing */
4544 end_ch = '}' * 0x100 + ':';
4546 if (BASH_PATTERN_SUBST
4549 /* It's ${var/[/]pattern[/repl]} thing */
4550 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4552 nommu_addchr(as_string, '/');
4555 end_ch = '}' * 0x100 + '/';
4561 #if ENABLE_HUSH_DOLLAR_OPS
4562 last_ch = add_till_closing_bracket(dest, input, end_ch);
4563 if (last_ch == 0) /* error? */
4566 #error Simple code to only allow ${var} is not implemented
4569 o_addstr(as_string, dest->data + pos);
4570 o_addchr(as_string, last_ch);
4573 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4574 && (end_ch & 0xff00)
4576 /* close the first block: */
4577 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4578 /* while parsing N from ${var:N[:M]}
4579 * or pattern from ${var/[/]pattern[/repl]} */
4580 if ((end_ch & 0xff) == last_ch) {
4581 /* got ':' or '/'- parse the rest */
4586 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4587 /* it's ${var:N} - emulate :999999999 */
4588 o_addstr(dest, "999999999");
4589 } /* else: it's ${var/[/]pattern} */
4593 len_single_ch = 0; /* it can't be ${#C} op */
4595 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4598 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4602 ch = i_getch(input);
4603 nommu_addchr(as_string, ch);
4604 # if ENABLE_FEATURE_SH_MATH
4605 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4606 ch = i_getch(input);
4607 nommu_addchr(as_string, ch);
4608 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4609 o_addchr(dest, /*quote_mask |*/ '+');
4612 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4613 return 0; /* error */
4615 o_addstr(as_string, dest->data + pos);
4616 o_addchr(as_string, ')');
4617 o_addchr(as_string, ')');
4619 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4623 # if ENABLE_HUSH_TICK
4624 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4625 o_addchr(dest, quote_mask | '`');
4628 if (!add_till_closing_bracket(dest, input, ')'))
4629 return 0; /* error */
4631 o_addstr(as_string, dest->data + pos);
4632 o_addchr(as_string, ')');
4634 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4640 ch = i_getch(input);
4641 nommu_addchr(as_string, ch);
4642 ch = i_peek_and_eat_bkslash_nl(input);
4643 if (isalnum(ch)) { /* it's $_name or $_123 */
4648 /* TODO: $_ and $-: */
4649 /* $_ Shell or shell script name; or last argument of last command
4650 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4651 * but in command's env, set to full pathname used to invoke it */
4652 /* $- Option flags set by set builtin or shell options (-i etc) */
4654 o_addQchr(dest, '$');
4656 debug_printf_parse("parse_dollar return 1 (ok)\n");
4662 # if BASH_PATTERN_SUBST
4663 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4664 encode_string(dest, input, dquote_end, process_bkslash)
4666 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4667 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4668 encode_string(dest, input, dquote_end)
4670 #define as_string NULL
4674 # if BASH_PATTERN_SUBST
4675 /* all parameters are needed, no macro tricks */
4677 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4678 encode_string(as_string, dest, input, dquote_end)
4681 static int encode_string(o_string *as_string,
4683 struct in_str *input,
4685 int process_bkslash)
4687 #if !BASH_PATTERN_SUBST
4688 const int process_bkslash = 1;
4694 ch = i_getch(input);
4696 nommu_addchr(as_string, ch);
4697 if (ch == dquote_end) { /* may be only '"' or EOF */
4698 debug_printf_parse("encode_string return 1 (ok)\n");
4701 /* note: can't move it above ch == dquote_end check! */
4703 syntax_error_unterm_ch('"');
4704 return 0; /* error */
4708 next = i_peek(input);
4710 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4711 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4712 if (process_bkslash && ch == '\\') {
4714 syntax_error("\\<eof>");
4718 * "The backslash retains its special meaning [in "..."]
4719 * only when followed by one of the following characters:
4720 * $, `, ", \, or <newline>. A double quote may be quoted
4721 * within double quotes by preceding it with a backslash."
4722 * NB: in (unquoted) heredoc, above does not apply to ",
4723 * therefore we check for it by "next == dquote_end" cond.
4725 if (next == dquote_end || strchr("$`\\\n", next)) {
4726 ch = i_getch(input); /* eat next */
4728 goto again; /* skip \<newline> */
4729 } /* else: ch remains == '\\', and we double it below: */
4730 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4731 nommu_addchr(as_string, ch);
4735 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4736 debug_printf_parse("encode_string return 0: "
4737 "parse_dollar returned 0 (error)\n");
4742 #if ENABLE_HUSH_TICK
4744 //unsigned pos = dest->length;
4745 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4746 o_addchr(dest, 0x80 | '`');
4747 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4748 return 0; /* error */
4749 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4750 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4754 o_addQchr(dest, ch);
4760 * Scan input until EOF or end_trigger char.
4761 * Return a list of pipes to execute, or NULL on EOF
4762 * or if end_trigger character is met.
4763 * On syntax error, exit if shell is not interactive,
4764 * reset parsing machinery and start parsing anew,
4765 * or return ERR_PTR.
4767 static struct pipe *parse_stream(char **pstring,
4768 struct in_str *input,
4771 struct parse_context ctx;
4772 o_string dest = NULL_O_STRING;
4775 /* Single-quote triggers a bypass of the main loop until its mate is
4776 * found. When recursing, quote state is passed in via dest->o_expflags.
4778 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4779 end_trigger ? end_trigger : 'X');
4782 /* If very first arg is "" or '', dest.data may end up NULL.
4783 * Preventing this: */
4784 o_addchr(&dest, '\0');
4787 /* We used to separate words on $IFS here. This was wrong.
4788 * $IFS is used only for word splitting when $var is expanded,
4789 * here we should use blank chars as separators, not $IFS
4792 if (MAYBE_ASSIGNMENT != 0)
4793 dest.o_assignment = MAYBE_ASSIGNMENT;
4794 initialize_context(&ctx);
4797 const char *is_blank;
4798 const char *is_special;
4802 redir_type redir_style;
4804 ch = i_getch(input);
4805 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4806 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4811 syntax_error_unterm_str("here document");
4814 if (end_trigger == ')') {
4815 syntax_error_unterm_ch('(');
4818 if (end_trigger == '}') {
4819 syntax_error_unterm_ch('{');
4823 if (done_word(&dest, &ctx)) {
4827 done_pipe(&ctx, PIPE_SEQ);
4829 /* If we got nothing... */
4830 /* (this makes bare "&" cmd a no-op.
4831 * bash says: "syntax error near unexpected token '&'") */
4832 if (pi->num_cmds == 0
4833 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4839 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4841 *pstring = ctx.as_string.data;
4843 o_free_unsafe(&ctx.as_string);
4846 debug_printf_parse("parse_stream return %p\n", pi);
4849 nommu_addchr(&ctx.as_string, ch);
4853 next = i_peek(input);
4855 is_special = "{}<>;&|()#'" /* special outside of "str" */
4856 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4857 /* Are { and } special here? */
4858 if (ctx.command->argv /* word [word]{... - non-special */
4859 || dest.length /* word{... - non-special */
4860 || dest.has_quoted_part /* ""{... - non-special */
4861 || (next != ';' /* }; - special */
4862 && next != ')' /* }) - special */
4863 && next != '(' /* {( - special */
4864 && next != '&' /* }& and }&& ... - special */
4865 && next != '|' /* }|| ... - special */
4866 && !strchr(defifs, next) /* {word - non-special */
4869 /* They are not special, skip "{}" */
4872 is_special = strchr(is_special, ch);
4873 is_blank = strchr(defifs, ch);
4875 if (!is_special && !is_blank) { /* ordinary char */
4877 o_addQchr(&dest, ch);
4878 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4879 || dest.o_assignment == WORD_IS_KEYWORD)
4881 && is_well_formed_var_name(dest.data, '=')
4883 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4884 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4890 if (done_word(&dest, &ctx)) {
4894 /* Is this a case when newline is simply ignored?
4896 * "cmd | <newline> cmd ..."
4897 * "case ... in <newline> word) ..."
4899 if (IS_NULL_CMD(ctx.command)
4900 && dest.length == 0 && !dest.has_quoted_part
4902 /* This newline can be ignored. But...
4903 * Without check #1, interactive shell
4904 * ignores even bare <newline>,
4905 * and shows the continuation prompt:
4906 * ps1_prompt$ <enter>
4907 * ps2> _ <=== wrong, should be ps1
4908 * Without check #2, "cmd & <newline>"
4909 * is similarly mistreated.
4910 * (BTW, this makes "cmd & cmd"
4911 * and "cmd && cmd" non-orthogonal.
4912 * Really, ask yourself, why
4913 * "cmd && <newline>" doesn't start
4914 * cmd but waits for more input?
4915 * The only reason is that it might be
4916 * a "cmd1 && <nl> cmd2 &" construct,
4917 * cmd1 may need to run in BG).
4919 struct pipe *pi = ctx.list_head;
4920 if (pi->num_cmds != 0 /* check #1 */
4921 && pi->followup != PIPE_BG /* check #2 */
4926 /* Treat newline as a command separator. */
4927 done_pipe(&ctx, PIPE_SEQ);
4928 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4930 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4935 dest.o_assignment = MAYBE_ASSIGNMENT;
4936 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4938 /* note: if (is_blank) continue;
4939 * will still trigger for us */
4943 /* "cmd}" or "cmd }..." without semicolon or &:
4944 * } is an ordinary char in this case, even inside { cmd; }
4945 * Pathological example: { ""}; } should exec "}" cmd
4948 if (dest.length != 0 /* word} */
4949 || dest.has_quoted_part /* ""} */
4953 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4954 /* Generally, there should be semicolon: "cmd; }"
4955 * However, bash allows to omit it if "cmd" is
4956 * a group. Examples:
4959 * { echo 0 >&2 | { echo 1; } }
4960 * { while false; do :; done }
4961 * { case a in b) ;; esac }
4963 if (ctx.command->group)
4967 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4968 /* Can't be an end of {cmd}, skip the check */
4969 goto skip_end_trigger;
4970 /* else: } does terminate a group */
4973 if (end_trigger && end_trigger == ch
4974 && (ch != ';' || heredoc_cnt == 0)
4975 #if ENABLE_HUSH_CASE
4977 || ctx.ctx_res_w != RES_MATCH
4978 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4983 /* This is technically valid:
4984 * { cat <<HERE; }; echo Ok
4988 * but we don't support this.
4989 * We require heredoc to be in enclosing {}/(),
4992 syntax_error_unterm_str("here document");
4995 if (done_word(&dest, &ctx)) {
4998 done_pipe(&ctx, PIPE_SEQ);
4999 dest.o_assignment = MAYBE_ASSIGNMENT;
5000 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5001 /* Do we sit outside of any if's, loops or case's? */
5003 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5007 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5009 *pstring = ctx.as_string.data;
5011 o_free_unsafe(&ctx.as_string);
5014 debug_printf_parse("parse_stream return %p: "
5015 "end_trigger char found\n",
5017 return ctx.list_head;
5024 /* Catch <, > before deciding whether this word is
5025 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5028 redir_fd = redirect_opt_num(&dest);
5029 if (done_word(&dest, &ctx)) {
5032 redir_style = REDIRECT_OVERWRITE;
5034 redir_style = REDIRECT_APPEND;
5035 ch = i_getch(input);
5036 nommu_addchr(&ctx.as_string, ch);
5039 else if (next == '(') {
5040 syntax_error(">(process) not supported");
5044 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5046 continue; /* back to top of while (1) */
5048 redir_fd = redirect_opt_num(&dest);
5049 if (done_word(&dest, &ctx)) {
5052 redir_style = REDIRECT_INPUT;
5054 redir_style = REDIRECT_HEREDOC;
5056 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5057 ch = i_getch(input);
5058 nommu_addchr(&ctx.as_string, ch);
5059 } else if (next == '>') {
5060 redir_style = REDIRECT_IO;
5061 ch = i_getch(input);
5062 nommu_addchr(&ctx.as_string, ch);
5065 else if (next == '(') {
5066 syntax_error("<(process) not supported");
5070 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5072 continue; /* back to top of while (1) */
5074 if (dest.length == 0 && !dest.has_quoted_part) {
5075 /* skip "#comment" */
5078 if (ch == EOF || ch == '\n')
5081 /* note: we do not add it to &ctx.as_string */
5083 nommu_addchr(&ctx.as_string, '\n');
5084 continue; /* back to top of while (1) */
5089 /* It's "\<newline>" */
5091 /* Remove trailing '\' from ctx.as_string */
5092 ctx.as_string.data[--ctx.as_string.length] = '\0';
5094 ch = i_getch(input); /* eat it */
5095 continue; /* back to top of while (1) */
5100 if (dest.o_assignment == MAYBE_ASSIGNMENT
5101 /* check that we are not in word in "a=1 2>word b=1": */
5102 && !ctx.pending_redirect
5104 /* ch is a special char and thus this word
5105 * cannot be an assignment */
5106 dest.o_assignment = NOT_ASSIGNMENT;
5107 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5110 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5113 case '#': /* non-comment #: "echo a#b" etc */
5114 o_addQchr(&dest, ch);
5118 syntax_error("\\<eof>");
5121 ch = i_getch(input);
5122 /* note: ch != '\n' (that case does not reach this place) */
5123 o_addchr(&dest, '\\');
5124 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5125 o_addchr(&dest, ch);
5126 nommu_addchr(&ctx.as_string, ch);
5127 /* Example: echo Hello \2>file
5128 * we need to know that word 2 is quoted */
5129 dest.has_quoted_part = 1;
5132 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5133 debug_printf_parse("parse_stream parse error: "
5134 "parse_dollar returned 0 (error)\n");
5139 dest.has_quoted_part = 1;
5140 if (next == '\'' && !ctx.pending_redirect) {
5141 insert_empty_quoted_str_marker:
5142 nommu_addchr(&ctx.as_string, next);
5143 i_getch(input); /* eat second ' */
5144 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5145 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5148 ch = i_getch(input);
5150 syntax_error_unterm_ch('\'');
5153 nommu_addchr(&ctx.as_string, ch);
5156 o_addqchr(&dest, ch);
5161 dest.has_quoted_part = 1;
5162 if (next == '"' && !ctx.pending_redirect)
5163 goto insert_empty_quoted_str_marker;
5164 if (dest.o_assignment == NOT_ASSIGNMENT)
5165 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5166 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5168 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5170 #if ENABLE_HUSH_TICK
5172 USE_FOR_NOMMU(unsigned pos;)
5174 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5175 o_addchr(&dest, '`');
5176 USE_FOR_NOMMU(pos = dest.length;)
5177 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5180 o_addstr(&ctx.as_string, dest.data + pos);
5181 o_addchr(&ctx.as_string, '`');
5183 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5184 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5189 #if ENABLE_HUSH_CASE
5192 if (done_word(&dest, &ctx)) {
5195 done_pipe(&ctx, PIPE_SEQ);
5196 #if ENABLE_HUSH_CASE
5197 /* Eat multiple semicolons, detect
5198 * whether it means something special */
5203 ch = i_getch(input);
5204 nommu_addchr(&ctx.as_string, ch);
5205 if (ctx.ctx_res_w == RES_CASE_BODY) {
5206 ctx.ctx_dsemicolon = 1;
5207 ctx.ctx_res_w = RES_MATCH;
5213 /* We just finished a cmd. New one may start
5214 * with an assignment */
5215 dest.o_assignment = MAYBE_ASSIGNMENT;
5216 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5219 if (done_word(&dest, &ctx)) {
5223 ch = i_getch(input);
5224 nommu_addchr(&ctx.as_string, ch);
5225 done_pipe(&ctx, PIPE_AND);
5227 done_pipe(&ctx, PIPE_BG);
5231 if (done_word(&dest, &ctx)) {
5234 #if ENABLE_HUSH_CASE
5235 if (ctx.ctx_res_w == RES_MATCH)
5236 break; /* we are in case's "word | word)" */
5238 if (next == '|') { /* || */
5239 ch = i_getch(input);
5240 nommu_addchr(&ctx.as_string, ch);
5241 done_pipe(&ctx, PIPE_OR);
5243 /* we could pick up a file descriptor choice here
5244 * with redirect_opt_num(), but bash doesn't do it.
5245 * "echo foo 2| cat" yields "foo 2". */
5250 #if ENABLE_HUSH_CASE
5251 /* "case... in [(]word)..." - skip '(' */
5252 if (ctx.ctx_res_w == RES_MATCH
5253 && ctx.command->argv == NULL /* not (word|(... */
5254 && dest.length == 0 /* not word(... */
5255 && dest.has_quoted_part == 0 /* not ""(... */
5261 if (parse_group(&dest, &ctx, input, ch) != 0) {
5266 #if ENABLE_HUSH_CASE
5267 if (ctx.ctx_res_w == RES_MATCH)
5271 /* proper use of this character is caught by end_trigger:
5272 * if we see {, we call parse_group(..., end_trigger='}')
5273 * and it will match } earlier (not here). */
5274 syntax_error_unexpected_ch(ch);
5275 G.last_exitcode = 2;
5279 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5284 G.last_exitcode = 1;
5287 struct parse_context *pctx;
5288 IF_HAS_KEYWORDS(struct parse_context *p2;)
5290 /* Clean up allocated tree.
5291 * Sample for finding leaks on syntax error recovery path.
5292 * Run it from interactive shell, watch pmap `pidof hush`.
5293 * while if false; then false; fi; do break; fi
5294 * Samples to catch leaks at execution:
5295 * while if (true | { true;}); then echo ok; fi; do break; done
5296 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5300 /* Update pipe/command counts,
5301 * otherwise freeing may miss some */
5302 done_pipe(pctx, PIPE_SEQ);
5303 debug_printf_clean("freeing list %p from ctx %p\n",
5304 pctx->list_head, pctx);
5305 debug_print_tree(pctx->list_head, 0);
5306 free_pipe_list(pctx->list_head);
5307 debug_printf_clean("freed list %p\n", pctx->list_head);
5309 o_free_unsafe(&pctx->as_string);
5311 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5315 IF_HAS_KEYWORDS(pctx = p2;)
5316 } while (HAS_KEYWORDS && pctx);
5329 /*** Execution routines ***/
5331 /* Expansion can recurse, need forward decls: */
5332 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5333 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5334 #define expand_string_to_string(str, do_unbackslash) \
5335 expand_string_to_string(str)
5337 static char *expand_string_to_string(const char *str, int do_unbackslash);
5338 #if ENABLE_HUSH_TICK
5339 static int process_command_subs(o_string *dest, const char *s);
5342 /* expand_strvec_to_strvec() takes a list of strings, expands
5343 * all variable references within and returns a pointer to
5344 * a list of expanded strings, possibly with larger number
5345 * of strings. (Think VAR="a b"; echo $VAR).
5346 * This new list is allocated as a single malloc block.
5347 * NULL-terminated list of char* pointers is at the beginning of it,
5348 * followed by strings themselves.
5349 * Caller can deallocate entire list by single free(list). */
5351 /* A horde of its helpers come first: */
5353 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5355 while (--len >= 0) {
5358 #if ENABLE_HUSH_BRACE_EXPANSION
5359 if (c == '{' || c == '}') {
5360 /* { -> \{, } -> \} */
5362 /* And now we want to add { or } and continue:
5365 * luckily, just falling through achieves this.
5371 /* \z -> \\\z; \<eol> -> \\<eol> */
5376 o_addchr(o, *str++);
5382 /* Store given string, finalizing the word and starting new one whenever
5383 * we encounter IFS char(s). This is used for expanding variable values.
5384 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5385 * Return in *ended_with_ifs:
5386 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5388 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5390 int last_is_ifs = 0;
5395 if (!*str) /* EOL - do not finalize word */
5397 word_len = strcspn(str, G.ifs);
5399 /* We have WORD_LEN leading non-IFS chars */
5400 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5401 o_addblock(output, str, word_len);
5403 /* Protect backslashes against globbing up :)
5404 * Example: "v='\*'; echo b$v" prints "b\*"
5405 * (and does not try to glob on "*")
5407 o_addblock_duplicate_backslash(output, str, word_len);
5408 /*/ Why can't we do it easier? */
5409 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5410 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5414 if (!*str) /* EOL - do not finalize word */
5418 /* We know str here points to at least one IFS char */
5420 str += strspn(str, G.ifs); /* skip IFS chars */
5421 if (!*str) /* EOL - do not finalize word */
5424 /* Start new word... but not always! */
5425 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5426 if (output->has_quoted_part
5427 /* Case "v=' a'; echo $v":
5428 * here nothing precedes the space in $v expansion,
5429 * therefore we should not finish the word
5430 * (IOW: if there *is* word to finalize, only then do it):
5432 || (n > 0 && output->data[output->length - 1])
5434 o_addchr(output, '\0');
5435 debug_print_list("expand_on_ifs", output, n);
5436 n = o_save_ptr(output, n);
5441 *ended_with_ifs = last_is_ifs;
5442 debug_print_list("expand_on_ifs[1]", output, n);
5446 /* Helper to expand $((...)) and heredoc body. These act as if
5447 * they are in double quotes, with the exception that they are not :).
5448 * Just the rules are similar: "expand only $var and `cmd`"
5450 * Returns malloced string.
5451 * As an optimization, we return NULL if expansion is not needed.
5453 #if !BASH_PATTERN_SUBST
5454 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5455 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5456 encode_then_expand_string(str)
5458 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5460 #if !BASH_PATTERN_SUBST
5461 const int do_unbackslash = 1;
5464 struct in_str input;
5465 o_string dest = NULL_O_STRING;
5467 if (!strchr(str, '$')
5468 && !strchr(str, '\\')
5469 #if ENABLE_HUSH_TICK
5470 && !strchr(str, '`')
5476 /* We need to expand. Example:
5477 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5479 setup_string_in_str(&input, str);
5480 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5481 //TODO: error check (encode_string returns 0 on error)?
5482 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5483 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5484 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5485 o_free_unsafe(&dest);
5489 #if ENABLE_FEATURE_SH_MATH
5490 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5492 arith_state_t math_state;
5496 math_state.lookupvar = get_local_var_value;
5497 math_state.setvar = set_local_var_from_halves;
5498 //math_state.endofname = endofname;
5499 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5500 res = arith(&math_state, exp_str ? exp_str : arg);
5503 *errmsg_p = math_state.errmsg;
5504 if (math_state.errmsg)
5505 die_if_script(math_state.errmsg);
5510 #if BASH_PATTERN_SUBST
5511 /* ${var/[/]pattern[/repl]} helpers */
5512 static char *strstr_pattern(char *val, const char *pattern, int *size)
5515 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5516 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5523 /* Optimization: if "*pat" did not match the start of "string",
5524 * we know that "tring", "ring" etc will not match too:
5526 if (pattern[0] == '*')
5531 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5533 char *result = NULL;
5534 unsigned res_len = 0;
5535 unsigned repl_len = strlen(repl);
5539 char *s = strstr_pattern(val, pattern, &size);
5543 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5544 strcpy(mempcpy(result + res_len, val, s - val), repl);
5545 res_len += (s - val) + repl_len;
5546 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5552 if (*val && result) {
5553 result = xrealloc(result, res_len + strlen(val) + 1);
5554 strcpy(result + res_len, val);
5555 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5557 debug_printf_varexp("result:'%s'\n", result);
5560 #endif /* BASH_PATTERN_SUBST */
5563 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5565 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5567 const char *val = NULL;
5568 char *to_be_freed = NULL;
5573 char exp_save = exp_save; /* for compiler */
5574 char *exp_saveptr; /* points to expansion operator */
5575 char *exp_word = exp_word; /* for compiler */
5578 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5580 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5582 first_char = arg[0] = arg0 & 0x7f;
5585 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5586 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5587 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5588 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5590 /* It must be length operator: ${#var} */
5594 /* Maybe handle parameter expansion */
5595 if (exp_saveptr /* if 2nd char is one of expansion operators */
5596 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5598 /* ${?:0}, ${#[:]%0} etc */
5599 exp_saveptr = var + 1;
5601 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5602 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5604 exp_op = exp_save = *exp_saveptr;
5606 exp_word = exp_saveptr + 1;
5607 if (exp_op == ':') {
5608 exp_op = *exp_word++;
5609 //TODO: try ${var:} and ${var:bogus} in non-bash config
5611 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5613 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5618 *exp_saveptr = '\0';
5619 } /* else: it's not an expansion op, but bare ${var} */
5622 /* Look up the variable in question */
5623 if (isdigit(var[0])) {
5624 /* parse_dollar should have vetted var for us */
5625 int n = xatoi_positive(var);
5626 if (n < G.global_argc)
5627 val = G.global_argv[n];
5628 /* else val remains NULL: $N with too big N */
5632 val = utoa(G.root_pid);
5634 case '!': /* bg pid */
5635 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5637 case '?': /* exitcode */
5638 val = utoa(G.last_exitcode);
5640 case '#': /* argc */
5641 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5644 val = get_local_var_value(var);
5648 /* Handle any expansions */
5649 if (exp_op == 'L') {
5650 reinit_unicode_for_hush();
5651 debug_printf_expand("expand: length(%s)=", val);
5652 val = utoa(val ? unicode_strlen(val) : 0);
5653 debug_printf_expand("%s\n", val);
5654 } else if (exp_op) {
5655 if (exp_op == '%' || exp_op == '#') {
5656 /* Standard-mandated substring removal ops:
5657 * ${parameter%word} - remove smallest suffix pattern
5658 * ${parameter%%word} - remove largest suffix pattern
5659 * ${parameter#word} - remove smallest prefix pattern
5660 * ${parameter##word} - remove largest prefix pattern
5662 * Word is expanded to produce a glob pattern.
5663 * Then var's value is matched to it and matching part removed.
5665 if (val && val[0]) {
5669 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5670 if (exp_op == *exp_word) /* ## or %% */
5672 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5674 exp_word = exp_exp_word;
5675 /* HACK ALERT. We depend here on the fact that
5676 * G.global_argv and results of utoa and get_local_var_value
5677 * are actually in writable memory:
5678 * scan_and_match momentarily stores NULs there. */
5680 loc = scan_and_match(t, exp_word, scan_flags);
5681 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5682 // exp_op, t, exp_word, loc);
5684 if (loc) { /* match was found */
5685 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5686 val = loc; /* take right part */
5688 val = to_be_freed = xstrndup(val, loc - val); /* left */
5692 #if BASH_PATTERN_SUBST
5693 else if (exp_op == '/' || exp_op == '\\') {
5694 /* It's ${var/[/]pattern[/repl]} thing.
5695 * Note that in encoded form it has TWO parts:
5696 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5697 * and if // is used, it is encoded as \:
5698 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5700 /* Empty variable always gives nothing: */
5701 // "v=''; echo ${v/*/w}" prints "", not "w"
5702 if (val && val[0]) {
5703 /* pattern uses non-standard expansion.
5704 * repl should be unbackslashed and globbed
5705 * by the usual expansion rules:
5707 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5708 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5709 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5710 * v='a bz'; echo ${v/a*z/\z} prints "z"
5711 * (note that a*z _pattern_ is never globbed!)
5713 char *pattern, *repl, *t;
5714 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5716 pattern = xstrdup(exp_word);
5717 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5718 *p++ = SPECIAL_VAR_SYMBOL;
5720 p = strchr(p, SPECIAL_VAR_SYMBOL);
5722 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5723 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5724 /* HACK ALERT. We depend here on the fact that
5725 * G.global_argv and results of utoa and get_local_var_value
5726 * are actually in writable memory:
5727 * replace_pattern momentarily stores NULs there. */
5729 to_be_freed = replace_pattern(t,
5731 (repl ? repl : exp_word),
5733 if (to_be_freed) /* at least one replace happened */
5739 #endif /* BASH_PATTERN_SUBST */
5740 else if (exp_op == ':') {
5741 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5742 /* It's ${var:N[:M]} bashism.
5743 * Note that in encoded form it has TWO parts:
5744 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5749 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5752 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5753 *p++ = SPECIAL_VAR_SYMBOL;
5755 p = strchr(p, SPECIAL_VAR_SYMBOL);
5757 len = expand_and_evaluate_arith(exp_word, &errmsg);
5760 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5762 /* negative beg counts from the end */
5763 beg = (arith_t)strlen(val) + beg;
5764 if (beg < 0) /* ${v: -999999} is "" */
5767 debug_printf_varexp("from val:'%s'\n", val);
5769 /* in bash, len=-n means strlen()-n */
5770 len = (arith_t)strlen(val) - beg + len;
5771 if (len < 0) /* bash compat */
5772 die_if_script("%s: substring expression < 0", var);
5774 if (len <= 0 || !val || beg >= strlen(val)) {
5778 /* Paranoia. What if user entered 9999999999999
5779 * which fits in arith_t but not int? */
5782 val = to_be_freed = xstrndup(val + beg, len);
5784 debug_printf_varexp("val:'%s'\n", val);
5785 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5786 die_if_script("malformed ${%s:...}", var);
5789 } else { /* one of "-=+?" */
5790 /* Standard-mandated substitution ops:
5791 * ${var?word} - indicate error if unset
5792 * If var is unset, word (or a message indicating it is unset
5793 * if word is null) is written to standard error
5794 * and the shell exits with a non-zero exit status.
5795 * Otherwise, the value of var is substituted.
5796 * ${var-word} - use default value
5797 * If var is unset, word is substituted.
5798 * ${var=word} - assign and use default value
5799 * If var is unset, word is assigned to var.
5800 * In all cases, final value of var is substituted.
5801 * ${var+word} - use alternative value
5802 * If var is unset, null is substituted.
5803 * Otherwise, word is substituted.
5805 * Word is subjected to tilde expansion, parameter expansion,
5806 * command substitution, and arithmetic expansion.
5807 * If word is not needed, it is not expanded.
5809 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5810 * but also treat null var as if it is unset.
5812 int use_word = (!val || ((exp_save == ':') && !val[0]));
5814 use_word = !use_word;
5815 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5816 (exp_save == ':') ? "true" : "false", use_word);
5818 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5820 exp_word = to_be_freed;
5821 if (exp_op == '?') {
5822 /* mimic bash message */
5823 die_if_script("%s: %s",
5827 : "parameter null or not set"
5828 /* ash has more specific messages, a-la: */
5829 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5831 //TODO: how interactive bash aborts expansion mid-command?
5836 if (exp_op == '=') {
5837 /* ${var=[word]} or ${var:=[word]} */
5838 if (isdigit(var[0]) || var[0] == '#') {
5839 /* mimic bash message */
5840 die_if_script("$%s: cannot assign in this way", var);
5843 char *new_var = xasprintf("%s=%s", var, val);
5844 set_local_var(new_var, /*flag:*/ 0);
5848 } /* one of "-=+?" */
5850 *exp_saveptr = exp_save;
5856 *to_be_freed_pp = to_be_freed;
5860 /* Expand all variable references in given string, adding words to list[]
5861 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5862 * to be filled). This routine is extremely tricky: has to deal with
5863 * variables/parameters with whitespace, $* and $@, and constructs like
5864 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5865 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5867 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5868 * expansion of right-hand side of assignment == 1-element expand.
5870 char cant_be_null = 0; /* only bit 0x80 matters */
5871 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5874 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5875 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5876 debug_print_list("expand_vars_to_list", output, n);
5877 n = o_save_ptr(output, n);
5878 debug_print_list("expand_vars_to_list[0]", output, n);
5880 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5882 char *to_be_freed = NULL;
5883 const char *val = NULL;
5884 #if ENABLE_HUSH_TICK
5885 o_string subst_result = NULL_O_STRING;
5887 #if ENABLE_FEATURE_SH_MATH
5888 char arith_buf[sizeof(arith_t)*3 + 2];
5892 o_addchr(output, '\0');
5893 n = o_save_ptr(output, n);
5897 o_addblock(output, arg, p - arg);
5898 debug_print_list("expand_vars_to_list[1]", output, n);
5900 p = strchr(p, SPECIAL_VAR_SYMBOL);
5902 /* Fetch special var name (if it is indeed one of them)
5903 * and quote bit, force the bit on if singleword expansion -
5904 * important for not getting v=$@ expand to many words. */
5905 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5907 /* Is this variable quoted and thus expansion can't be null?
5908 * "$@" is special. Even if quoted, it can still
5909 * expand to nothing (not even an empty string),
5910 * thus it is excluded. */
5911 if ((first_ch & 0x7f) != '@')
5912 cant_be_null |= first_ch;
5914 switch (first_ch & 0x7f) {
5915 /* Highest bit in first_ch indicates that var is double-quoted */
5919 if (!G.global_argv[1])
5922 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5923 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5924 while (G.global_argv[i]) {
5925 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5926 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5927 if (G.global_argv[i++][0] && G.global_argv[i]) {
5928 /* this argv[] is not empty and not last:
5929 * put terminating NUL, start new word */
5930 o_addchr(output, '\0');
5931 debug_print_list("expand_vars_to_list[2]", output, n);
5932 n = o_save_ptr(output, n);
5933 debug_print_list("expand_vars_to_list[3]", output, n);
5937 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5938 * and in this case should treat it like '$*' - see 'else...' below */
5939 if (first_ch == ('@'|0x80) /* quoted $@ */
5940 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5943 o_addQstr(output, G.global_argv[i]);
5944 if (++i >= G.global_argc)
5946 o_addchr(output, '\0');
5947 debug_print_list("expand_vars_to_list[4]", output, n);
5948 n = o_save_ptr(output, n);
5950 } else { /* quoted $* (or v="$@" case): add as one word */
5952 o_addQstr(output, G.global_argv[i]);
5953 if (!G.global_argv[++i])
5956 o_addchr(output, G.ifs[0]);
5958 output->has_quoted_part = 1;
5962 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5963 /* "Empty variable", used to make "" etc to not disappear */
5964 output->has_quoted_part = 1;
5966 cant_be_null = 0x80;
5968 #if ENABLE_HUSH_TICK
5969 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5970 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5972 /* Can't just stuff it into output o_string,
5973 * expanded result may need to be globbed
5975 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5976 G.last_exitcode = process_command_subs(&subst_result, arg);
5977 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5978 val = subst_result.data;
5981 #if ENABLE_FEATURE_SH_MATH
5982 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5985 arg++; /* skip '+' */
5986 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5987 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5988 res = expand_and_evaluate_arith(arg, NULL);
5989 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5990 sprintf(arith_buf, ARITH_FMT, res);
5996 val = expand_one_var(&to_be_freed, arg, &p);
5997 IF_HUSH_TICK(store_val:)
5998 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5999 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6000 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6001 if (val && val[0]) {
6002 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6005 } else { /* quoted $VAR, val will be appended below */
6006 output->has_quoted_part = 1;
6007 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6008 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6011 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6013 if (val && val[0]) {
6014 o_addQstr(output, val);
6018 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6019 * Do the check to avoid writing to a const string. */
6020 if (*p != SPECIAL_VAR_SYMBOL)
6021 *p = SPECIAL_VAR_SYMBOL;
6023 #if ENABLE_HUSH_TICK
6024 o_free(&subst_result);
6027 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6031 o_addchr(output, '\0');
6032 n = o_save_ptr(output, n);
6034 debug_print_list("expand_vars_to_list[a]", output, n);
6035 /* this part is literal, and it was already pre-quoted
6036 * if needed (much earlier), do not use o_addQstr here! */
6037 o_addstr_with_NUL(output, arg);
6038 debug_print_list("expand_vars_to_list[b]", output, n);
6039 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6040 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6043 /* allow to reuse list[n] later without re-growth */
6044 output->has_empty_slot = 1;
6046 o_addchr(output, '\0');
6052 static char **expand_variables(char **argv, unsigned expflags)
6056 o_string output = NULL_O_STRING;
6058 output.o_expflags = expflags;
6062 n = expand_vars_to_list(&output, n, *argv);
6065 debug_print_list("expand_variables", &output, n);
6067 /* output.data (malloced in one block) gets returned in "list" */
6068 list = o_finalize_list(&output, n);
6069 debug_print_strings("expand_variables[1]", list);
6073 static char **expand_strvec_to_strvec(char **argv)
6075 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6079 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6081 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6085 /* Used for expansion of right hand of assignments,
6086 * $((...)), heredocs, variable espansion parts.
6088 * NB: should NOT do globbing!
6089 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6091 static char *expand_string_to_string(const char *str, int do_unbackslash)
6093 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6094 const int do_unbackslash = 1;
6096 char *argv[2], **list;
6098 debug_printf_expand("string_to_string<='%s'\n", str);
6099 /* This is generally an optimization, but it also
6100 * handles "", which otherwise trips over !list[0] check below.
6101 * (is this ever happens that we actually get str="" here?)
6103 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6104 //TODO: Can use on strings with \ too, just unbackslash() them?
6105 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6106 return xstrdup(str);
6109 argv[0] = (char*)str;
6111 list = expand_variables(argv, do_unbackslash
6112 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6113 : EXP_FLAG_SINGLEWORD
6116 if (!list[0] || list[1])
6117 bb_error_msg_and_die("BUG in varexp2");
6118 /* actually, just move string 2*sizeof(char*) bytes back */
6119 overlapping_strcpy((char*)list, list[0]);
6121 unbackslash((char*)list);
6122 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6126 /* Used for "eval" builtin and case string */
6127 static char* expand_strvec_to_string(char **argv)
6131 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6132 /* Convert all NULs to spaces */
6137 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6138 bb_error_msg_and_die("BUG in varexp3");
6139 /* bash uses ' ' regardless of $IFS contents */
6144 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6145 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6149 static char **expand_assignments(char **argv, int count)
6154 G.expanded_assignments = p = NULL;
6155 /* Expand assignments into one string each */
6156 for (i = 0; i < count; i++) {
6157 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6159 G.expanded_assignments = NULL;
6164 static void switch_off_special_sigs(unsigned mask)
6167 while ((mask >>= 1) != 0) {
6171 #if ENABLE_HUSH_TRAP
6173 if (G_traps[sig] && !G_traps[sig][0])
6174 /* trap is '', has to remain SIG_IGN */
6177 G_traps[sig] = NULL;
6180 /* We are here only if no trap or trap was not '' */
6181 install_sighandler(sig, SIG_DFL);
6187 void re_execute_shell(char ***to_free, const char *s,
6188 char *g_argv0, char **g_argv,
6189 char **builtin_argv) NORETURN;
6191 static void reset_traps_to_defaults(void)
6193 /* This function is always called in a child shell
6194 * after fork (not vfork, NOMMU doesn't use this function).
6196 IF_HUSH_TRAP(unsigned sig;)
6199 /* Child shells are not interactive.
6200 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6201 * Testcase: (while :; do :; done) + ^Z should background.
6202 * Same goes for SIGTERM, SIGHUP, SIGINT.
6204 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6205 if (!G_traps && !mask)
6206 return; /* already no traps and no special sigs */
6208 /* Switch off special sigs */
6209 switch_off_special_sigs(mask);
6210 # if ENABLE_HUSH_JOB
6211 G_fatal_sig_mask = 0;
6213 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6214 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6215 * remain set in G.special_sig_mask */
6217 # if ENABLE_HUSH_TRAP
6221 /* Reset all sigs to default except ones with empty traps */
6222 for (sig = 0; sig < NSIG; sig++) {
6224 continue; /* no trap: nothing to do */
6225 if (!G_traps[sig][0])
6226 continue; /* empty trap: has to remain SIG_IGN */
6227 /* sig has non-empty trap, reset it: */
6229 G_traps[sig] = NULL;
6230 /* There is no signal for trap 0 (EXIT) */
6233 install_sighandler(sig, pick_sighandler(sig));
6240 static void re_execute_shell(char ***to_free, const char *s,
6241 char *g_argv0, char **g_argv,
6242 char **builtin_argv) NORETURN;
6243 static void re_execute_shell(char ***to_free, const char *s,
6244 char *g_argv0, char **g_argv,
6245 char **builtin_argv)
6247 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6248 /* delims + 2 * (number of bytes in printed hex numbers) */
6249 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6250 char *heredoc_argv[4];
6251 struct variable *cur;
6252 # if ENABLE_HUSH_FUNCTIONS
6253 struct function *funcp;
6257 unsigned long long empty_trap_mask;
6259 if (!g_argv0) { /* heredoc */
6260 argv = heredoc_argv;
6261 argv[0] = (char *) G.argv0_for_re_execing;
6262 argv[1] = (char *) "-<";
6263 argv[2] = (char *) s;
6265 pp = &argv[3]; /* used as pointer to empty environment */
6271 if (pp) while (*pp++)
6274 empty_trap_mask = 0;
6277 for (sig = 1; sig < NSIG; sig++) {
6278 if (G_traps[sig] && !G_traps[sig][0])
6279 empty_trap_mask |= 1LL << sig;
6283 sprintf(param_buf, NOMMU_HACK_FMT
6284 , (unsigned) G.root_pid
6285 , (unsigned) G.root_ppid
6286 , (unsigned) G.last_bg_pid
6287 , (unsigned) G.last_exitcode
6290 IF_HUSH_LOOPS(, G.depth_of_loop)
6292 # undef NOMMU_HACK_FMT
6293 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6294 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6297 for (cur = G.top_var; cur; cur = cur->next) {
6298 if (!cur->flg_export || cur->flg_read_only)
6301 # if ENABLE_HUSH_FUNCTIONS
6302 for (funcp = G.top_func; funcp; funcp = funcp->next)
6308 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6309 *pp++ = (char *) G.argv0_for_re_execing;
6311 for (cur = G.top_var; cur; cur = cur->next) {
6312 if (strcmp(cur->varstr, hush_version_str) == 0)
6314 if (cur->flg_read_only) {
6315 *pp++ = (char *) "-R";
6316 *pp++ = cur->varstr;
6317 } else if (!cur->flg_export) {
6318 *pp++ = (char *) "-V";
6319 *pp++ = cur->varstr;
6322 # if ENABLE_HUSH_FUNCTIONS
6323 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6324 *pp++ = (char *) "-F";
6325 *pp++ = funcp->name;
6326 *pp++ = funcp->body_as_string;
6329 /* We can pass activated traps here. Say, -Tnn:trap_string
6331 * However, POSIX says that subshells reset signals with traps
6333 * I tested bash-3.2 and it not only does that with true subshells
6334 * of the form ( list ), but with any forked children shells.
6335 * I set trap "echo W" WINCH; and then tried:
6337 * { echo 1; sleep 20; echo 2; } &
6338 * while true; do echo 1; sleep 20; echo 2; break; done &
6339 * true | { echo 1; sleep 20; echo 2; } | cat
6341 * In all these cases sending SIGWINCH to the child shell
6342 * did not run the trap. If I add trap "echo V" WINCH;
6343 * _inside_ group (just before echo 1), it works.
6345 * I conclude it means we don't need to pass active traps here.
6347 *pp++ = (char *) "-c";
6350 while (*++builtin_argv)
6351 *pp++ = *builtin_argv;
6352 *pp++ = (char *) "";
6357 /* *pp = NULL; - is already there */
6361 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6362 /* Don't propagate SIG_IGN to the child */
6363 if (SPECIAL_JOBSTOP_SIGS != 0)
6364 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6365 execve(bb_busybox_exec_path, argv, pp);
6366 /* Fallback. Useful for init=/bin/hush usage etc */
6367 if (argv[0][0] == '/')
6368 execve(argv[0], argv, pp);
6369 xfunc_error_retval = 127;
6370 bb_error_msg_and_die("can't re-execute the shell");
6372 #endif /* !BB_MMU */
6375 static int run_and_free_list(struct pipe *pi);
6377 /* Executing from string: eval, sh -c '...'
6378 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6379 * end_trigger controls how often we stop parsing
6380 * NUL: parse all, execute, return
6381 * ';': parse till ';' or newline, execute, repeat till EOF
6383 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6385 /* Why we need empty flag?
6386 * An obscure corner case "false; ``; echo $?":
6387 * empty command in `` should still set $? to 0.
6388 * But we can't just set $? to 0 at the start,
6389 * this breaks "false; echo `echo $?`" case.
6393 struct pipe *pipe_list;
6395 #if ENABLE_HUSH_INTERACTIVE
6396 if (end_trigger == ';')
6397 inp->promptmode = 0; /* PS1 */
6399 pipe_list = parse_stream(NULL, inp, end_trigger);
6400 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6401 /* If we are in "big" script
6402 * (not in `cmd` or something similar)...
6404 if (pipe_list == ERR_PTR && end_trigger == ';') {
6405 /* Discard cached input (rest of line) */
6406 int ch = inp->last_char;
6407 while (ch != EOF && ch != '\n') {
6408 //bb_error_msg("Discarded:'%c'", ch);
6413 /* This stream isn't empty */
6417 if (!pipe_list && empty)
6418 G.last_exitcode = 0;
6421 debug_print_tree(pipe_list, 0);
6422 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6423 run_and_free_list(pipe_list);
6425 if (G_flag_return_in_progress == 1)
6430 static void parse_and_run_string(const char *s)
6432 struct in_str input;
6433 setup_string_in_str(&input, s);
6434 parse_and_run_stream(&input, '\0');
6437 static void parse_and_run_file(FILE *f)
6439 struct in_str input;
6440 setup_file_in_str(&input, f);
6441 parse_and_run_stream(&input, ';');
6444 #if ENABLE_HUSH_TICK
6445 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6450 char **to_free = NULL;
6454 pid = BB_MMU ? xfork() : xvfork();
6455 if (pid == 0) { /* child */
6456 disable_restore_tty_pgrp_on_exit();
6457 /* Process substitution is not considered to be usual
6458 * 'command execution'.
6459 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6466 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6467 close(channel[0]); /* NB: close _first_, then move fd! */
6468 xmove_fd(channel[1], 1);
6469 /* Prevent it from trying to handle ctrl-z etc */
6470 IF_HUSH_JOB(G.run_list_level = 1;)
6471 # if ENABLE_HUSH_TRAP
6472 /* Awful hack for `trap` or $(trap).
6474 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6475 * contains an example where "trap" is executed in a subshell:
6477 * save_traps=$(trap)
6479 * eval "$save_traps"
6481 * Standard does not say that "trap" in subshell shall print
6482 * parent shell's traps. It only says that its output
6483 * must have suitable form, but then, in the above example
6484 * (which is not supposed to be normative), it implies that.
6486 * bash (and probably other shell) does implement it
6487 * (traps are reset to defaults, but "trap" still shows them),
6488 * but as a result, "trap" logic is hopelessly messed up:
6491 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6492 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6493 * # true | trap <--- trap is in subshell - no output (ditto)
6494 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6495 * trap -- 'echo Ho' SIGWINCH
6496 * # echo `(trap)` <--- in subshell in subshell - output
6497 * trap -- 'echo Ho' SIGWINCH
6498 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6499 * trap -- 'echo Ho' SIGWINCH
6501 * The rules when to forget and when to not forget traps
6502 * get really complex and nonsensical.
6504 * Our solution: ONLY bare $(trap) or `trap` is special.
6506 s = skip_whitespace(s);
6507 if (is_prefixed_with(s, "trap")
6508 && skip_whitespace(s + 4)[0] == '\0'
6510 static const char *const argv[] = { NULL, NULL };
6511 builtin_trap((char**)argv);
6512 fflush_all(); /* important */
6517 reset_traps_to_defaults();
6518 parse_and_run_string(s);
6519 _exit(G.last_exitcode);
6521 /* We re-execute after vfork on NOMMU. This makes this script safe:
6522 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6523 * huge=`cat BIG` # was blocking here forever
6526 re_execute_shell(&to_free,
6536 # if ENABLE_HUSH_FAST
6538 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6539 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6540 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6542 enable_restore_tty_pgrp_on_exit();
6547 return remember_FILE(xfdopen_for_read(channel[0]));
6550 /* Return code is exit status of the process that is run. */
6551 static int process_command_subs(o_string *dest, const char *s)
6554 struct in_str pipe_str;
6556 int status, ch, eol_cnt;
6558 fp = generate_stream_from_string(s, &pid);
6560 /* Now send results of command back into original context */
6561 setup_file_in_str(&pipe_str, fp);
6563 while ((ch = i_getch(&pipe_str)) != EOF) {
6569 o_addchr(dest, '\n');
6572 o_addQchr(dest, ch);
6575 debug_printf("done reading from `cmd` pipe, closing it\n");
6576 fclose_and_forget(fp);
6577 /* We need to extract exitcode. Test case
6578 * "true; echo `sleep 1; false` $?"
6580 safe_waitpid(pid, &status, 0);
6581 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6582 return WEXITSTATUS(status);
6584 #endif /* ENABLE_HUSH_TICK */
6587 static void setup_heredoc(struct redir_struct *redir)
6589 struct fd_pair pair;
6592 /* the _body_ of heredoc (misleading field name) */
6593 const char *heredoc = redir->rd_filename;
6600 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6601 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6605 len = strlen(heredoc);
6607 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6609 xmove_fd(pair.rd, redir->rd_fd);
6611 /* Try writing without forking. Newer kernels have
6612 * dynamically growing pipes. Must use non-blocking write! */
6615 written = write(pair.wr, heredoc, len);
6626 ndelay_off(pair.wr);
6628 /* Okay, pipe buffer was not big enough */
6629 /* Note: we must not create a stray child (bastard? :)
6630 * for the unsuspecting parent process. Child creates a grandchild
6631 * and exits before parent execs the process which consumes heredoc
6632 * (that exec happens after we return from this function) */
6639 disable_restore_tty_pgrp_on_exit();
6640 pid = BB_MMU ? xfork() : xvfork();
6644 close(redir->rd_fd); /* read side of the pipe */
6646 full_write(pair.wr, heredoc, len); /* may loop or block */
6649 /* Delegate blocking writes to another process */
6650 xmove_fd(pair.wr, STDOUT_FILENO);
6651 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6655 #if ENABLE_HUSH_FAST
6657 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6659 enable_restore_tty_pgrp_on_exit();
6665 wait(NULL); /* wait till child has died */
6671 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6672 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6675 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6677 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6678 sq[i].orig_fd = orig;
6679 sq[i].moved_to = moved;
6680 sq[i+1].orig_fd = -1; /* end marker */
6684 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6689 if (sq) while (sq[i].orig_fd >= 0) {
6690 /* If we collide with an already moved fd... */
6691 if (fd == sq[i].moved_to) {
6692 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6693 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6694 if (sq[i].moved_to < 0) /* what? */
6698 if (fd == sq[i].orig_fd) {
6699 /* Example: echo Hello >/dev/null 1>&2 */
6700 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6706 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6707 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6708 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6709 if (moved_to < 0 && errno != EBADF)
6711 return append_squirrel(sq, i, fd, moved_to);
6714 /* fd: redirect wants this fd to be used (e.g. 3>file).
6715 * Move all conflicting internally used fds,
6716 * and remember them so that we can restore them later.
6718 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6720 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6723 #if ENABLE_HUSH_INTERACTIVE
6724 if (fd != 0 && fd == G.interactive_fd) {
6725 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6726 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6727 return 1; /* "we closed fd" */
6730 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6731 * (1) Redirect in a forked child. No need to save FILEs' fds,
6732 * we aren't going to use them anymore, ok to trash.
6733 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6734 * but how are we doing to restore them?
6735 * "fileno(fd) = new_fd" can't be done.
6740 /* If this one of script's fds? */
6741 if (save_FILEs_on_redirect(fd, avoid_fd))
6742 return 1; /* yes. "we closed fd" */
6744 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6745 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6746 return 0; /* "we did not close fd" */
6749 static void restore_redirects(struct squirrel *sq)
6754 while (sq[i].orig_fd >= 0) {
6755 if (sq[i].moved_to >= 0) {
6756 /* We simply die on error */
6757 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6758 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6760 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6761 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6762 close(sq[i].orig_fd);
6769 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6771 restore_redirected_FILEs();
6774 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6775 * and stderr if they are redirected. */
6776 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6779 struct redir_struct *redir;
6781 for (redir = prog->redirects; redir; redir = redir->next) {
6782 if (redir->rd_type == REDIRECT_HEREDOC2) {
6783 /* "rd_fd<<HERE" case */
6784 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6785 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6787 debug_printf_parse("set heredoc '%s'\n",
6788 redir->rd_filename);
6789 setup_heredoc(redir);
6793 if (redir->rd_dup == REDIRFD_TO_FILE) {
6794 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6796 if (redir->rd_filename == NULL) {
6799 * "cmd >" (no filename)
6800 * "cmd > <file" (2nd redirect starts too early)
6802 die_if_script("syntax error: %s", "invalid redirect");
6805 mode = redir_table[redir->rd_type].mode;
6806 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6807 openfd = open_or_warn(p, mode);
6810 /* Error message from open_or_warn can be lost
6811 * if stderr has been redirected, but bash
6812 * and ash both lose it as well
6813 * (though zsh doesn't!)
6817 if (openfd == redir->rd_fd && sqp) {
6818 /* open() gave us precisely the fd we wanted.
6819 * This means that this fd was not busy
6820 * (not opened to anywhere).
6821 * Remember to close it on restore:
6823 struct squirrel *sq = *sqp;
6825 if (sq) while (sq[i].orig_fd >= 0)
6827 *sqp = append_squirrel(sq, i, openfd, -1); /* -1 = "it was closed" */
6828 debug_printf_redir("redir to previously closed fd %d\n", openfd);
6831 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6832 openfd = redir->rd_dup;
6835 if (openfd != redir->rd_fd) {
6836 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6837 if (openfd == REDIRFD_CLOSE) {
6838 /* "rd_fd >&-" means "close me" */
6840 /* ^^^ optimization: saving may already
6841 * have closed it. If not... */
6842 close(redir->rd_fd);
6845 xdup2(openfd, redir->rd_fd);
6846 if (redir->rd_dup == REDIRFD_TO_FILE)
6847 /* "rd_fd > FILE" */
6849 /* else: "rd_fd > rd_dup" */
6856 static char *find_in_path(const char *arg)
6859 const char *PATH = get_local_var_value("PATH");
6865 const char *end = strchrnul(PATH, ':');
6866 int sz = end - PATH; /* must be int! */
6870 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6872 /* We have xxx::yyyy in $PATH,
6873 * it means "use current dir" */
6876 if (access(ret, F_OK) == 0)
6889 static const struct built_in_command *find_builtin_helper(const char *name,
6890 const struct built_in_command *x,
6891 const struct built_in_command *end)
6894 if (strcmp(name, x->b_cmd) != 0) {
6898 debug_printf_exec("found builtin '%s'\n", name);
6903 static const struct built_in_command *find_builtin1(const char *name)
6905 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6907 static const struct built_in_command *find_builtin(const char *name)
6909 const struct built_in_command *x = find_builtin1(name);
6912 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6915 #if ENABLE_HUSH_FUNCTIONS
6916 static struct function **find_function_slot(const char *name)
6918 struct function **funcpp = &G.top_func;
6920 if (strcmp(name, (*funcpp)->name) == 0) {
6923 funcpp = &(*funcpp)->next;
6928 static const struct function *find_function(const char *name)
6930 const struct function *funcp = *find_function_slot(name);
6932 debug_printf_exec("found function '%s'\n", name);
6936 /* Note: takes ownership on name ptr */
6937 static struct function *new_function(char *name)
6939 struct function **funcpp = find_function_slot(name);
6940 struct function *funcp = *funcpp;
6942 if (funcp != NULL) {
6943 struct command *cmd = funcp->parent_cmd;
6944 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6946 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6948 /* Note: if !funcp->body, do not free body_as_string!
6949 * This is a special case of "-F name body" function:
6950 * body_as_string was not malloced! */
6952 free_pipe_list(funcp->body);
6954 free(funcp->body_as_string);
6958 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6959 cmd->argv[0] = funcp->name;
6960 cmd->group = funcp->body;
6962 cmd->group_as_string = funcp->body_as_string;
6966 debug_printf_exec("remembering new function '%s'\n", name);
6967 funcp = *funcpp = xzalloc(sizeof(*funcp));
6968 /*funcp->next = NULL;*/
6975 # if ENABLE_HUSH_UNSET
6976 static void unset_func(const char *name)
6978 struct function **funcpp = find_function_slot(name);
6979 struct function *funcp = *funcpp;
6981 if (funcp != NULL) {
6982 debug_printf_exec("freeing function '%s'\n", funcp->name);
6983 *funcpp = funcp->next;
6984 /* funcp is unlinked now, deleting it.
6985 * Note: if !funcp->body, the function was created by
6986 * "-F name body", do not free ->body_as_string
6987 * and ->name as they were not malloced. */
6989 free_pipe_list(funcp->body);
6992 free(funcp->body_as_string);
7001 #define exec_function(to_free, funcp, argv) \
7002 exec_function(funcp, argv)
7004 static void exec_function(char ***to_free,
7005 const struct function *funcp,
7006 char **argv) NORETURN;
7007 static void exec_function(char ***to_free,
7008 const struct function *funcp,
7014 argv[0] = G.global_argv[0];
7015 G.global_argv = argv;
7016 G.global_argc = n = 1 + string_array_len(argv + 1);
7017 /* On MMU, funcp->body is always non-NULL */
7018 n = run_list(funcp->body);
7022 re_execute_shell(to_free,
7023 funcp->body_as_string,
7030 static int run_function(const struct function *funcp, char **argv)
7036 save_and_replace_G_args(&sv, argv);
7038 /* "we are in function, ok to use return" */
7039 sv_flg = G_flag_return_in_progress;
7040 G_flag_return_in_progress = -1;
7041 # if ENABLE_HUSH_LOCAL
7042 G.func_nest_level++;
7045 /* On MMU, funcp->body is always non-NULL */
7048 /* Function defined by -F */
7049 parse_and_run_string(funcp->body_as_string);
7050 rc = G.last_exitcode;
7054 rc = run_list(funcp->body);
7057 # if ENABLE_HUSH_LOCAL
7059 struct variable *var;
7060 struct variable **var_pp;
7062 var_pp = &G.top_var;
7063 while ((var = *var_pp) != NULL) {
7064 if (var->func_nest_level < G.func_nest_level) {
7065 var_pp = &var->next;
7069 if (var->flg_export)
7070 bb_unsetenv(var->varstr);
7071 /* Remove from global list */
7072 *var_pp = var->next;
7078 G.func_nest_level--;
7081 G_flag_return_in_progress = sv_flg;
7083 restore_G_args(&sv, argv);
7087 #endif /* ENABLE_HUSH_FUNCTIONS */
7091 #define exec_builtin(to_free, x, argv) \
7092 exec_builtin(x, argv)
7094 #define exec_builtin(to_free, x, argv) \
7095 exec_builtin(to_free, argv)
7097 static void exec_builtin(char ***to_free,
7098 const struct built_in_command *x,
7099 char **argv) NORETURN;
7100 static void exec_builtin(char ***to_free,
7101 const struct built_in_command *x,
7107 rcode = x->b_function(argv);
7112 /* On NOMMU, we must never block!
7113 * Example: { sleep 99 | read line; } & echo Ok
7115 re_execute_shell(to_free,
7124 static void execvp_or_die(char **argv) NORETURN;
7125 static void execvp_or_die(char **argv)
7128 debug_printf_exec("execing '%s'\n", argv[0]);
7129 /* Don't propagate SIG_IGN to the child */
7130 if (SPECIAL_JOBSTOP_SIGS != 0)
7131 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7132 execvp(argv[0], argv);
7134 if (errno == EACCES) e = 126;
7135 if (errno == ENOENT) e = 127;
7136 bb_perror_msg("can't execute '%s'", argv[0]);
7140 #if ENABLE_HUSH_MODE_X
7141 static void dump_cmd_in_x_mode(char **argv)
7143 if (G_x_mode && argv) {
7144 /* We want to output the line in one write op */
7152 len += strlen(argv[n++]) + 1;
7158 p += sprintf(p, " %s", argv[n++]);
7166 # define dump_cmd_in_x_mode(argv) ((void)0)
7170 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7171 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7172 #define pseudo_exec(nommu_save, command, argv_expanded) \
7173 pseudo_exec(command, argv_expanded)
7176 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7178 * Don't exit() here. If you don't exec, use _exit instead.
7179 * The at_exit handlers apparently confuse the calling process,
7180 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7182 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7183 char **argv, int assignment_cnt,
7184 char **argv_expanded) NORETURN;
7185 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7186 char **argv, int assignment_cnt,
7187 char **argv_expanded)
7191 new_env = expand_assignments(argv, assignment_cnt);
7192 dump_cmd_in_x_mode(new_env);
7194 if (!argv[assignment_cnt]) {
7195 /* Case when we are here: ... | var=val | ...
7196 * (note that we do not exit early, i.e., do not optimize out
7197 * expand_assignments(): think about ... | var=`sleep 1` | ...
7199 free_strings(new_env);
7200 _exit(EXIT_SUCCESS);
7204 set_vars_and_save_old(new_env);
7205 free(new_env); /* optional */
7206 /* we can also destroy set_vars_and_save_old's return value,
7209 nommu_save->new_env = new_env;
7210 nommu_save->old_vars = set_vars_and_save_old(new_env);
7213 if (argv_expanded) {
7214 argv = argv_expanded;
7216 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7218 nommu_save->argv = argv;
7221 dump_cmd_in_x_mode(argv);
7223 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7224 if (strchr(argv[0], '/') != NULL)
7228 /* Check if the command matches any of the builtins.
7229 * Depending on context, this might be redundant. But it's
7230 * easier to waste a few CPU cycles than it is to figure out
7231 * if this is one of those cases.
7234 /* On NOMMU, it is more expensive to re-execute shell
7235 * just in order to run echo or test builtin.
7236 * It's better to skip it here and run corresponding
7237 * non-builtin later. */
7238 const struct built_in_command *x;
7239 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7241 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7244 #if ENABLE_HUSH_FUNCTIONS
7245 /* Check if the command matches any functions */
7247 const struct function *funcp = find_function(argv[0]);
7249 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7254 #if ENABLE_FEATURE_SH_STANDALONE
7255 /* Check if the command matches any busybox applets */
7257 int a = find_applet_by_name(argv[0]);
7259 # if BB_MMU /* see above why on NOMMU it is not allowed */
7260 if (APPLET_IS_NOEXEC(a)) {
7261 /* Do not leak open fds from opened script files etc */
7262 close_all_FILE_list();
7263 debug_printf_exec("running applet '%s'\n", argv[0]);
7264 run_applet_no_and_exit(a, argv[0], argv);
7267 /* Re-exec ourselves */
7268 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7269 /* Don't propagate SIG_IGN to the child */
7270 if (SPECIAL_JOBSTOP_SIGS != 0)
7271 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7272 execv(bb_busybox_exec_path, argv);
7273 /* If they called chroot or otherwise made the binary no longer
7274 * executable, fall through */
7279 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7282 execvp_or_die(argv);
7285 /* Called after [v]fork() in run_pipe
7287 static void pseudo_exec(nommu_save_t *nommu_save,
7288 struct command *command,
7289 char **argv_expanded) NORETURN;
7290 static void pseudo_exec(nommu_save_t *nommu_save,
7291 struct command *command,
7292 char **argv_expanded)
7294 if (command->argv) {
7295 pseudo_exec_argv(nommu_save, command->argv,
7296 command->assignment_cnt, argv_expanded);
7299 if (command->group) {
7300 /* Cases when we are here:
7303 * ... | ( list ) | ...
7304 * ... | { list } | ...
7308 debug_printf_exec("pseudo_exec: run_list\n");
7309 reset_traps_to_defaults();
7310 rcode = run_list(command->group);
7311 /* OK to leak memory by not calling free_pipe_list,
7312 * since this process is about to exit */
7315 re_execute_shell(&nommu_save->argv_from_re_execing,
7316 command->group_as_string,
7323 /* Case when we are here: ... | >file */
7324 debug_printf_exec("pseudo_exec'ed null command\n");
7325 _exit(EXIT_SUCCESS);
7329 static const char *get_cmdtext(struct pipe *pi)
7335 /* This is subtle. ->cmdtext is created only on first backgrounding.
7336 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7337 * On subsequent bg argv is trashed, but we won't use it */
7341 argv = pi->cmds[0].argv;
7343 pi->cmdtext = xzalloc(1);
7348 len += strlen(*argv) + 1;
7352 argv = pi->cmds[0].argv;
7354 p = stpcpy(p, *argv);
7361 static void remove_job_from_table(struct pipe *pi)
7363 struct pipe *prev_pipe;
7365 if (pi == G.job_list) {
7366 G.job_list = pi->next;
7368 prev_pipe = G.job_list;
7369 while (prev_pipe->next != pi)
7370 prev_pipe = prev_pipe->next;
7371 prev_pipe->next = pi->next;
7375 G.last_jobid = G.job_list->jobid;
7378 static void delete_finished_job(struct pipe *pi)
7380 remove_job_from_table(pi);
7384 static void clean_up_last_dead_job(void)
7386 if (G.job_list && !G.job_list->alive_cmds)
7387 delete_finished_job(G.job_list);
7390 static void insert_job_into_table(struct pipe *pi)
7392 struct pipe *job, **jobp;
7395 clean_up_last_dead_job();
7397 /* Find the end of the list, and find next job ID to use */
7400 while ((job = *jobp) != NULL) {
7407 /* Create a new job struct at the end */
7408 job = *jobp = xmemdup(pi, sizeof(*pi));
7410 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7411 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7412 for (i = 0; i < pi->num_cmds; i++) {
7413 job->cmds[i].pid = pi->cmds[i].pid;
7414 /* all other fields are not used and stay zero */
7416 job->cmdtext = xstrdup(get_cmdtext(pi));
7418 if (G_interactive_fd)
7419 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7420 G.last_jobid = job->jobid;
7424 static int job_exited_or_stopped(struct pipe *pi)
7428 if (pi->alive_cmds != pi->stopped_cmds)
7431 /* All processes in fg pipe have exited or stopped */
7435 rcode = pi->cmds[i].cmd_exitcode;
7436 /* usually last process gives overall exitstatus,
7437 * but with "set -o pipefail", last *failed* process does */
7438 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7441 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7445 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7452 dead = WIFEXITED(status) || WIFSIGNALED(status);
7455 if (WIFSTOPPED(status))
7456 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7457 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7458 if (WIFSIGNALED(status))
7459 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7460 childpid, WTERMSIG(status), WEXITSTATUS(status));
7461 if (WIFEXITED(status))
7462 debug_printf_jobs("pid %d exited, exitcode %d\n",
7463 childpid, WEXITSTATUS(status));
7465 /* Were we asked to wait for a fg pipe? */
7467 i = fg_pipe->num_cmds;
7472 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7473 if (fg_pipe->cmds[i].pid != childpid)
7477 fg_pipe->cmds[i].pid = 0;
7478 fg_pipe->alive_cmds--;
7479 ex = WEXITSTATUS(status);
7480 /* bash prints killer signal's name for *last*
7481 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7482 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7484 if (WIFSIGNALED(status)) {
7485 int sig = WTERMSIG(status);
7486 if (i == fg_pipe->num_cmds-1)
7487 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7488 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7489 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7490 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7491 * Maybe we need to use sig | 128? */
7494 fg_pipe->cmds[i].cmd_exitcode = ex;
7496 fg_pipe->stopped_cmds++;
7498 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7499 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7500 rcode = job_exited_or_stopped(fg_pipe);
7502 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7503 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7504 * and "killall -STOP cat" */
7505 if (G_interactive_fd) {
7507 if (fg_pipe->alive_cmds != 0)
7508 insert_job_into_table(fg_pipe);
7512 if (fg_pipe->alive_cmds == 0)
7515 /* There are still running processes in the fg_pipe */
7518 /* It wasn't in fg_pipe, look for process in bg pipes */
7522 /* We were asked to wait for bg or orphaned children */
7523 /* No need to remember exitcode in this case */
7524 for (pi = G.job_list; pi; pi = pi->next) {
7525 for (i = 0; i < pi->num_cmds; i++) {
7526 if (pi->cmds[i].pid == childpid)
7527 goto found_pi_and_prognum;
7530 /* Happens when shell is used as init process (init=/bin/sh) */
7531 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7532 return -1; /* this wasn't a process from fg_pipe */
7534 found_pi_and_prognum:
7537 int rcode = WEXITSTATUS(status);
7538 if (WIFSIGNALED(status))
7539 rcode = 128 + WTERMSIG(status);
7540 pi->cmds[i].cmd_exitcode = rcode;
7541 if (G.last_bg_pid == pi->cmds[i].pid)
7542 G.last_bg_pid_exitcode = rcode;
7543 pi->cmds[i].pid = 0;
7545 if (!pi->alive_cmds) {
7546 if (G_interactive_fd) {
7547 printf(JOB_STATUS_FORMAT, pi->jobid,
7548 "Done", pi->cmdtext);
7549 delete_finished_job(pi);
7552 * bash deletes finished jobs from job table only in interactive mode,
7553 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7554 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7555 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7556 * We only retain one "dead" job, if it's the single job on the list.
7557 * This covers most of real-world scenarios where this is useful.
7559 if (pi != G.job_list)
7560 delete_finished_job(pi);
7568 return -1; /* this wasn't a process from fg_pipe */
7571 /* Check to see if any processes have exited -- if they have,
7572 * figure out why and see if a job has completed.
7574 * If non-NULL fg_pipe: wait for its completion or stop.
7575 * Return its exitcode or zero if stopped.
7577 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7578 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7579 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7580 * or 0 if no children changed status.
7582 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7583 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7584 * or 0 if no children changed status.
7586 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7592 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7594 attributes = WUNTRACED;
7595 if (fg_pipe == NULL)
7596 attributes |= WNOHANG;
7599 #if ENABLE_HUSH_FAST
7600 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7601 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7602 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7603 /* There was neither fork nor SIGCHLD since last waitpid */
7604 /* Avoid doing waitpid syscall if possible */
7605 if (!G.we_have_children) {
7609 if (fg_pipe == NULL) { /* is WNOHANG set? */
7610 /* We have children, but they did not exit
7611 * or stop yet (we saw no SIGCHLD) */
7614 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7618 /* Do we do this right?
7619 * bash-3.00# sleep 20 | false
7621 * [3]+ Stopped sleep 20 | false
7622 * bash-3.00# echo $?
7623 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7624 * [hush 1.14.0: yes we do it right]
7628 #if ENABLE_HUSH_FAST
7630 i = G.count_SIGCHLD;
7632 childpid = waitpid(-1, &status, attributes);
7633 if (childpid <= 0) {
7634 if (childpid && errno != ECHILD)
7635 bb_perror_msg("waitpid");
7636 #if ENABLE_HUSH_FAST
7637 else { /* Until next SIGCHLD, waitpid's are useless */
7638 G.we_have_children = (childpid == 0);
7639 G.handled_SIGCHLD = i;
7640 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7643 /* ECHILD (no children), or 0 (no change in children status) */
7647 rcode = process_wait_result(fg_pipe, childpid, status);
7649 /* fg_pipe exited or stopped */
7652 if (childpid == waitfor_pid) {
7653 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7654 rcode = WEXITSTATUS(status);
7655 if (WIFSIGNALED(status))
7656 rcode = 128 + WTERMSIG(status);
7657 if (WIFSTOPPED(status))
7658 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7659 rcode = 128 + WSTOPSIG(status);
7661 break; /* "wait PID" called us, give it exitcode+1 */
7663 /* This wasn't one of our processes, or */
7664 /* fg_pipe still has running processes, do waitpid again */
7665 } /* while (waitpid succeeds)... */
7671 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7674 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7675 if (G_saved_tty_pgrp) {
7676 /* Job finished, move the shell to the foreground */
7677 p = getpgrp(); /* our process group id */
7678 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7679 tcsetpgrp(G_interactive_fd, p);
7685 /* Start all the jobs, but don't wait for anything to finish.
7688 * Return code is normally -1, when the caller has to wait for children
7689 * to finish to determine the exit status of the pipe. If the pipe
7690 * is a simple builtin command, however, the action is done by the
7691 * time run_pipe returns, and the exit code is provided as the
7694 * Returns -1 only if started some children. IOW: we have to
7695 * mask out retvals of builtins etc with 0xff!
7697 * The only case when we do not need to [v]fork is when the pipe
7698 * is single, non-backgrounded, non-subshell command. Examples:
7699 * cmd ; ... { list } ; ...
7700 * cmd && ... { list } && ...
7701 * cmd || ... { list } || ...
7702 * If it is, then we can run cmd as a builtin, NOFORK,
7703 * or (if SH_STANDALONE) an applet, and we can run the { list }
7704 * with run_list. If it isn't one of these, we fork and exec cmd.
7706 * Cases when we must fork:
7707 * non-single: cmd | cmd
7708 * backgrounded: cmd & { list } &
7709 * subshell: ( list ) [&]
7711 #if !ENABLE_HUSH_MODE_X
7712 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7713 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7715 static int redirect_and_varexp_helper(char ***new_env_p,
7716 struct variable **old_vars_p,
7717 struct command *command,
7718 struct squirrel **sqp,
7719 char **argv_expanded)
7721 /* setup_redirects acts on file descriptors, not FILEs.
7722 * This is perfect for work that comes after exec().
7723 * Is it really safe for inline use? Experimentally,
7724 * things seem to work. */
7725 int rcode = setup_redirects(command, sqp);
7727 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7728 *new_env_p = new_env;
7729 dump_cmd_in_x_mode(new_env);
7730 dump_cmd_in_x_mode(argv_expanded);
7732 *old_vars_p = set_vars_and_save_old(new_env);
7736 static NOINLINE int run_pipe(struct pipe *pi)
7738 static const char *const null_ptr = NULL;
7742 struct command *command;
7743 char **argv_expanded;
7745 struct squirrel *squirrel = NULL;
7748 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7751 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7752 * Result should be 3 lines: q w e, qwe, q w e
7754 G.ifs = get_local_var_value("IFS");
7758 IF_HUSH_JOB(pi->pgrp = -1;)
7759 pi->stopped_cmds = 0;
7760 command = &pi->cmds[0];
7761 argv_expanded = NULL;
7763 if (pi->num_cmds != 1
7764 || pi->followup == PIPE_BG
7765 || command->cmd_type == CMD_SUBSHELL
7772 debug_printf_exec(": group:%p argv:'%s'\n",
7773 command->group, command->argv ? command->argv[0] : "NONE");
7775 if (command->group) {
7776 #if ENABLE_HUSH_FUNCTIONS
7777 if (command->cmd_type == CMD_FUNCDEF) {
7778 /* "executing" func () { list } */
7779 struct function *funcp;
7781 funcp = new_function(command->argv[0]);
7782 /* funcp->name is already set to argv[0] */
7783 funcp->body = command->group;
7785 funcp->body_as_string = command->group_as_string;
7786 command->group_as_string = NULL;
7788 command->group = NULL;
7789 command->argv[0] = NULL;
7790 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7791 funcp->parent_cmd = command;
7792 command->child_func = funcp;
7794 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7796 return EXIT_SUCCESS;
7800 debug_printf("non-subshell group\n");
7801 rcode = 1; /* exitcode if redir failed */
7802 if (setup_redirects(command, &squirrel) == 0) {
7803 debug_printf_exec(": run_list\n");
7804 rcode = run_list(command->group) & 0xff;
7806 restore_redirects(squirrel);
7807 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7809 debug_printf_exec("run_pipe: return %d\n", rcode);
7813 argv = command->argv ? command->argv : (char **) &null_ptr;
7815 const struct built_in_command *x;
7816 #if ENABLE_HUSH_FUNCTIONS
7817 const struct function *funcp;
7821 char **new_env = NULL;
7822 struct variable *old_vars = NULL;
7824 if (argv[command->assignment_cnt] == NULL) {
7825 /* Assignments, but no command */
7826 /* Ensure redirects take effect (that is, create files).
7827 * Try "a=t >file" */
7828 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7829 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7830 /* Set shell variables */
7834 if (set_local_var(*argv, /*flag:*/ 0)) {
7835 /* assignment to readonly var / putenv error? */
7841 /* Redirect error sets $? to 1. Otherwise,
7842 * if evaluating assignment value set $?, retain it.
7843 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7845 rcode = G.last_exitcode;
7846 /* Exit, _skipping_ variable restoring code: */
7847 goto clean_up_and_ret0;
7849 #else /* Older, bigger, but more correct code */
7851 rcode = setup_redirects(command, &squirrel);
7852 restore_redirects(squirrel);
7853 /* Set shell variables */
7855 bb_putchar_stderr('+');
7857 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7859 fprintf(stderr, " %s", p);
7860 debug_printf_exec("set shell var:'%s'->'%s'\n",
7862 if (set_local_var(p, /*flag:*/ 0)) {
7863 /* assignment to readonly var / putenv error? */
7869 bb_putchar_stderr('\n');
7870 /* Redirect error sets $? to 1. Otherwise,
7871 * if evaluating assignment value set $?, retain it.
7872 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7874 rcode = G.last_exitcode;
7875 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7877 debug_printf_exec("run_pipe: return %d\n", rcode);
7882 /* Expand the rest into (possibly) many strings each */
7884 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7885 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7889 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7892 /* if someone gives us an empty string: `cmd with empty output` */
7893 if (!argv_expanded[0]) {
7894 free(argv_expanded);
7896 return G.last_exitcode;
7899 x = find_builtin(argv_expanded[0]);
7900 #if ENABLE_HUSH_FUNCTIONS
7903 funcp = find_function(argv_expanded[0]);
7907 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7908 debug_printf("exec with redirects only\n");
7909 rcode = setup_redirects(command, NULL);
7910 /* rcode=1 can be if redir file can't be opened */
7911 goto clean_up_and_ret1;
7914 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7917 debug_printf_exec(": builtin '%s' '%s'...\n",
7918 x->b_cmd, argv_expanded[1]);
7920 rcode = x->b_function(argv_expanded) & 0xff;
7923 #if ENABLE_HUSH_FUNCTIONS
7925 # if ENABLE_HUSH_LOCAL
7926 struct variable **sv;
7927 sv = G.shadowed_vars_pp;
7928 G.shadowed_vars_pp = &old_vars;
7930 debug_printf_exec(": function '%s' '%s'...\n",
7931 funcp->name, argv_expanded[1]);
7932 rcode = run_function(funcp, argv_expanded) & 0xff;
7933 # if ENABLE_HUSH_LOCAL
7934 G.shadowed_vars_pp = sv;
7940 unset_vars(new_env);
7942 /* clean_up_and_ret0: */
7943 restore_redirects(squirrel);
7945 free(argv_expanded);
7946 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7948 debug_printf_exec("run_pipe return %d\n", rcode);
7952 if (ENABLE_FEATURE_SH_NOFORK) {
7953 int n = find_applet_by_name(argv_expanded[0]);
7954 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7955 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7957 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7958 argv_expanded[0], argv_expanded[1]);
7959 rcode = run_nofork_applet(n, argv_expanded);
7961 goto clean_up_and_ret;
7964 /* It is neither builtin nor applet. We must fork. */
7968 /* NB: argv_expanded may already be created, and that
7969 * might include `cmd` runs! Do not rerun it! We *must*
7970 * use argv_expanded if it's non-NULL */
7972 /* Going to fork a child per each pipe member */
7977 while (cmd_no < pi->num_cmds) {
7978 struct fd_pair pipefds;
7980 volatile nommu_save_t nommu_save;
7981 nommu_save.new_env = NULL;
7982 nommu_save.old_vars = NULL;
7983 nommu_save.argv = NULL;
7984 nommu_save.argv_from_re_execing = NULL;
7986 command = &pi->cmds[cmd_no];
7988 if (command->argv) {
7989 debug_printf_exec(": pipe member '%s' '%s'...\n",
7990 command->argv[0], command->argv[1]);
7992 debug_printf_exec(": pipe member with no argv\n");
7995 /* pipes are inserted between pairs of commands */
7998 if (cmd_no < pi->num_cmds)
7999 xpiped_pair(pipefds);
8001 command->pid = BB_MMU ? fork() : vfork();
8002 if (!command->pid) { /* child */
8004 disable_restore_tty_pgrp_on_exit();
8005 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8007 /* Every child adds itself to new process group
8008 * with pgid == pid_of_first_child_in_pipe */
8009 if (G.run_list_level == 1 && G_interactive_fd) {
8012 if (pgrp < 0) /* true for 1st process only */
8014 if (setpgid(0, pgrp) == 0
8015 && pi->followup != PIPE_BG
8016 && G_saved_tty_pgrp /* we have ctty */
8018 /* We do it in *every* child, not just first,
8020 tcsetpgrp(G_interactive_fd, pgrp);
8024 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8025 /* 1st cmd in backgrounded pipe
8026 * should have its stdin /dev/null'ed */
8028 if (open(bb_dev_null, O_RDONLY))
8029 xopen("/", O_RDONLY);
8031 xmove_fd(next_infd, 0);
8033 xmove_fd(pipefds.wr, 1);
8036 /* Like bash, explicit redirects override pipes,
8037 * and the pipe fd (fd#1) is available for dup'ing:
8038 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8039 * of cmd1 goes into pipe.
8041 if (setup_redirects(command, NULL)) {
8042 /* Happens when redir file can't be opened:
8043 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8045 * hush: can't open '/qwe/rty': No such file or directory
8047 * (echo BAR is not executed, it hits _exit(1) below)
8052 /* Stores to nommu_save list of env vars putenv'ed
8053 * (NOMMU, on MMU we don't need that) */
8054 /* cast away volatility... */
8055 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8056 /* pseudo_exec() does not return */
8059 /* parent or error */
8060 #if ENABLE_HUSH_FAST
8062 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8064 enable_restore_tty_pgrp_on_exit();
8066 /* Clean up after vforked child */
8067 free(nommu_save.argv);
8068 free(nommu_save.argv_from_re_execing);
8069 unset_vars(nommu_save.new_env);
8070 add_vars(nommu_save.old_vars);
8072 free(argv_expanded);
8073 argv_expanded = NULL;
8074 if (command->pid < 0) { /* [v]fork failed */
8075 /* Clearly indicate, was it fork or vfork */
8076 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8080 /* Second and next children need to know pid of first one */
8082 pi->pgrp = command->pid;
8088 if (cmd_no < pi->num_cmds)
8090 /* Pass read (output) pipe end to next iteration */
8091 next_infd = pipefds.rd;
8094 if (!pi->alive_cmds) {
8096 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8101 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8105 /* NB: called by pseudo_exec, and therefore must not modify any
8106 * global data until exec/_exit (we can be a child after vfork!) */
8107 static int run_list(struct pipe *pi)
8109 #if ENABLE_HUSH_CASE
8110 char *case_word = NULL;
8112 #if ENABLE_HUSH_LOOPS
8113 struct pipe *loop_top = NULL;
8114 char **for_lcur = NULL;
8115 char **for_list = NULL;
8117 smallint last_followup;
8119 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8120 smalluint cond_code = 0;
8122 enum { cond_code = 0 };
8125 smallint rword; /* RES_foo */
8126 smallint last_rword; /* ditto */
8129 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8132 #if ENABLE_HUSH_LOOPS
8133 /* Check syntax for "for" */
8136 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8137 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8139 /* current word is FOR or IN (BOLD in comments below) */
8140 if (cpipe->next == NULL) {
8141 syntax_error("malformed for");
8143 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8146 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8147 if (cpipe->next->res_word == RES_DO)
8149 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8150 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8151 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8153 syntax_error("malformed for");
8155 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8162 /* Past this point, all code paths should jump to ret: label
8163 * in order to return, no direct "return" statements please.
8164 * This helps to ensure that no memory is leaked. */
8172 last_rword = RES_XXXX;
8174 last_followup = PIPE_SEQ;
8175 rcode = G.last_exitcode;
8177 /* Go through list of pipes, (maybe) executing them. */
8178 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8180 int sv_errexit_depth;
8184 if (G_flag_return_in_progress == 1)
8187 IF_HAS_KEYWORDS(rword = pi->res_word;)
8188 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8189 rword, cond_code, last_rword);
8191 sv_errexit_depth = G.errexit_depth;
8192 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8193 pi->followup != PIPE_SEQ
8197 #if ENABLE_HUSH_LOOPS
8198 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8199 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8201 /* start of a loop: remember where loop starts */
8206 /* Still in the same "if...", "then..." or "do..." branch? */
8207 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8208 if ((rcode == 0 && last_followup == PIPE_OR)
8209 || (rcode != 0 && last_followup == PIPE_AND)
8211 /* It is "<true> || CMD" or "<false> && CMD"
8212 * and we should not execute CMD */
8213 debug_printf_exec("skipped cmd because of || or &&\n");
8214 last_followup = pi->followup;
8215 goto dont_check_jobs_but_continue;
8218 last_followup = pi->followup;
8219 IF_HAS_KEYWORDS(last_rword = rword;)
8222 if (rword == RES_THEN) {
8223 /* if false; then ... fi has exitcode 0! */
8224 G.last_exitcode = rcode = EXIT_SUCCESS;
8225 /* "if <false> THEN cmd": skip cmd */
8229 if (rword == RES_ELSE || rword == RES_ELIF) {
8230 /* "if <true> then ... ELSE/ELIF cmd":
8231 * skip cmd and all following ones */
8236 #if ENABLE_HUSH_LOOPS
8237 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8239 /* first loop through for */
8241 static const char encoded_dollar_at[] ALIGN1 = {
8242 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8243 }; /* encoded representation of "$@" */
8244 static const char *const encoded_dollar_at_argv[] = {
8245 encoded_dollar_at, NULL
8246 }; /* argv list with one element: "$@" */
8249 vals = (char**)encoded_dollar_at_argv;
8250 if (pi->next->res_word == RES_IN) {
8251 /* if no variable values after "in" we skip "for" */
8252 if (!pi->next->cmds[0].argv) {
8253 G.last_exitcode = rcode = EXIT_SUCCESS;
8254 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8257 vals = pi->next->cmds[0].argv;
8258 } /* else: "for var; do..." -> assume "$@" list */
8259 /* create list of variable values */
8260 debug_print_strings("for_list made from", vals);
8261 for_list = expand_strvec_to_strvec(vals);
8262 for_lcur = for_list;
8263 debug_print_strings("for_list", for_list);
8266 /* "for" loop is over, clean up */
8272 /* Insert next value from for_lcur */
8273 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8274 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8277 if (rword == RES_IN) {
8278 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8280 if (rword == RES_DONE) {
8281 continue; /* "done" has no cmds too */
8284 #if ENABLE_HUSH_CASE
8285 if (rword == RES_CASE) {
8286 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8287 case_word = expand_strvec_to_string(pi->cmds->argv);
8288 unbackslash(case_word);
8291 if (rword == RES_MATCH) {
8294 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8295 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8297 /* all prev words didn't match, does this one match? */
8298 argv = pi->cmds->argv;
8300 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8301 /* TODO: which FNM_xxx flags to use? */
8302 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8303 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8305 if (cond_code == 0) { /* match! we will execute this branch */
8307 case_word = NULL; /* make future "word)" stop */
8314 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8315 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8317 continue; /* not matched yet, skip this pipe */
8319 if (rword == RES_ESAC) {
8320 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8322 /* "case" did not match anything: still set $? (to 0) */
8323 G.last_exitcode = rcode = EXIT_SUCCESS;
8327 /* Just pressing <enter> in shell should check for jobs.
8328 * OTOH, in non-interactive shell this is useless
8329 * and only leads to extra job checks */
8330 if (pi->num_cmds == 0) {
8331 if (G_interactive_fd)
8332 goto check_jobs_and_continue;
8336 /* After analyzing all keywords and conditions, we decided
8337 * to execute this pipe. NB: have to do checkjobs(NULL)
8338 * after run_pipe to collect any background children,
8339 * even if list execution is to be stopped. */
8340 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8341 #if ENABLE_HUSH_LOOPS
8342 G.flag_break_continue = 0;
8344 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8346 /* We ran a builtin, function, or group.
8347 * rcode is already known
8348 * and we don't need to wait for anything. */
8349 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8350 G.last_exitcode = rcode;
8351 check_and_run_traps();
8352 #if ENABLE_HUSH_LOOPS
8353 /* Was it "break" or "continue"? */
8354 if (G.flag_break_continue) {
8355 smallint fbc = G.flag_break_continue;
8356 /* We might fall into outer *loop*,
8357 * don't want to break it too */
8359 G.depth_break_continue--;
8360 if (G.depth_break_continue == 0)
8361 G.flag_break_continue = 0;
8362 /* else: e.g. "continue 2" should *break* once, *then* continue */
8363 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8364 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8365 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8368 /* "continue": simulate end of loop */
8373 if (G_flag_return_in_progress == 1) {
8374 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8377 } else if (pi->followup == PIPE_BG) {
8378 /* What does bash do with attempts to background builtins? */
8379 /* even bash 3.2 doesn't do that well with nested bg:
8380 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8381 * I'm NOT treating inner &'s as jobs */
8383 if (G.run_list_level == 1)
8384 insert_job_into_table(pi);
8386 /* Last command's pid goes to $! */
8387 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8388 G.last_bg_pid_exitcode = 0;
8389 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8390 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8391 rcode = EXIT_SUCCESS;
8395 if (G.run_list_level == 1 && G_interactive_fd) {
8396 /* Waits for completion, then fg's main shell */
8397 rcode = checkjobs_and_fg_shell(pi);
8398 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8402 /* This one just waits for completion */
8403 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8404 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8406 G.last_exitcode = rcode;
8407 check_and_run_traps();
8410 /* Handle "set -e" */
8411 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8412 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8413 if (G.errexit_depth == 0)
8416 G.errexit_depth = sv_errexit_depth;
8418 /* Analyze how result affects subsequent commands */
8420 if (rword == RES_IF || rword == RES_ELIF)
8423 check_jobs_and_continue:
8424 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8425 dont_check_jobs_but_continue: ;
8426 #if ENABLE_HUSH_LOOPS
8427 /* Beware of "while false; true; do ..."! */
8429 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8430 /* check for RES_DONE is needed for "while ...; do \n done" case */
8432 if (rword == RES_WHILE) {
8434 /* "while false; do...done" - exitcode 0 */
8435 G.last_exitcode = rcode = EXIT_SUCCESS;
8436 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8440 if (rword == RES_UNTIL) {
8442 debug_printf_exec(": until expr is true: breaking\n");
8453 #if ENABLE_HUSH_LOOPS
8458 #if ENABLE_HUSH_CASE
8462 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8466 /* Select which version we will use */
8467 static int run_and_free_list(struct pipe *pi)
8470 debug_printf_exec("run_and_free_list entered\n");
8471 if (!G.o_opt[OPT_O_NOEXEC]) {
8472 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8473 rcode = run_list(pi);
8475 /* free_pipe_list has the side effect of clearing memory.
8476 * In the long run that function can be merged with run_list,
8477 * but doing that now would hobble the debugging effort. */
8479 debug_printf_exec("run_and_free_list return %d\n", rcode);
8484 static void install_sighandlers(unsigned mask)
8486 sighandler_t old_handler;
8488 while ((mask >>= 1) != 0) {
8492 old_handler = install_sighandler(sig, pick_sighandler(sig));
8493 /* POSIX allows shell to re-enable SIGCHLD
8494 * even if it was SIG_IGN on entry.
8495 * Therefore we skip IGN check for it:
8499 if (old_handler == SIG_IGN) {
8500 /* oops... restore back to IGN, and record this fact */
8501 install_sighandler(sig, old_handler);
8502 #if ENABLE_HUSH_TRAP
8504 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8506 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8512 /* Called a few times only (or even once if "sh -c") */
8513 static void install_special_sighandlers(void)
8517 /* Which signals are shell-special? */
8518 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8519 if (G_interactive_fd) {
8520 mask |= SPECIAL_INTERACTIVE_SIGS;
8521 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8522 mask |= SPECIAL_JOBSTOP_SIGS;
8524 /* Careful, do not re-install handlers we already installed */
8525 if (G.special_sig_mask != mask) {
8526 unsigned diff = mask & ~G.special_sig_mask;
8527 G.special_sig_mask = mask;
8528 install_sighandlers(diff);
8534 /* Set handlers to restore tty pgrp and exit */
8535 static void install_fatal_sighandlers(void)
8539 /* We will restore tty pgrp on these signals */
8541 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8542 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8543 + (1 << SIGBUS ) * HUSH_DEBUG
8544 + (1 << SIGSEGV) * HUSH_DEBUG
8545 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8547 /* bash 3.2 seems to handle these just like 'fatal' ones */
8550 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8551 * if we aren't interactive... but in this case
8552 * we never want to restore pgrp on exit, and this fn is not called
8554 /*+ (1 << SIGHUP )*/
8555 /*+ (1 << SIGTERM)*/
8556 /*+ (1 << SIGINT )*/
8558 G_fatal_sig_mask = mask;
8560 install_sighandlers(mask);
8564 static int set_mode(int state, char mode, const char *o_opt)
8569 G.o_opt[OPT_O_NOEXEC] = state;
8572 IF_HUSH_MODE_X(G_x_mode = state;)
8576 /* "set -+o" without parameter.
8577 * in bash, set -o produces this output:
8581 * We always use the second form.
8583 const char *p = o_opt_strings;
8586 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8592 idx = index_in_strings(o_opt_strings, o_opt);
8594 G.o_opt[idx] = state;
8598 G.o_opt[OPT_O_ERREXIT] = state;
8601 return EXIT_FAILURE;
8603 return EXIT_SUCCESS;
8606 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8607 int hush_main(int argc, char **argv)
8610 OPT_login = (1 << 0),
8614 unsigned builtin_argc;
8616 struct variable *cur_var;
8617 struct variable *shell_ver;
8620 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8621 G.last_exitcode = EXIT_SUCCESS;
8623 #if ENABLE_HUSH_FAST
8624 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8627 G.argv0_for_re_execing = argv[0];
8629 /* Deal with HUSH_VERSION */
8630 shell_ver = xzalloc(sizeof(*shell_ver));
8631 shell_ver->flg_export = 1;
8632 shell_ver->flg_read_only = 1;
8633 /* Code which handles ${var<op>...} needs writable values for all variables,
8634 * therefore we xstrdup: */
8635 shell_ver->varstr = xstrdup(hush_version_str);
8636 /* Create shell local variables from the values
8637 * currently living in the environment */
8638 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8639 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8640 G.top_var = shell_ver;
8641 cur_var = G.top_var;
8644 char *value = strchr(*e, '=');
8645 if (value) { /* paranoia */
8646 cur_var->next = xzalloc(sizeof(*cur_var));
8647 cur_var = cur_var->next;
8648 cur_var->varstr = *e;
8649 cur_var->max_len = strlen(*e);
8650 cur_var->flg_export = 1;
8654 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8655 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8656 putenv(shell_ver->varstr);
8659 set_pwd_var(SETFLAG_EXPORT);
8661 #if BASH_HOSTNAME_VAR
8662 /* Set (but not export) HOSTNAME unless already set */
8663 if (!get_local_var_value("HOSTNAME")) {
8666 set_local_var_from_halves("HOSTNAME", uts.nodename);
8668 /* bash also exports SHLVL and _,
8669 * and sets (but doesn't export) the following variables:
8671 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8672 * BASH_VERSION='3.2.0(1)-release'
8674 * MACHTYPE=i386-pc-linux-gnu
8676 * PPID=<NNNNN> - we also do it elsewhere
8687 * PIPESTATUS=([0]="0")
8688 * HISTFILE=/<xxx>/.bash_history
8692 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8694 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8705 #if ENABLE_FEATURE_EDITING
8706 G.line_input_state = new_line_input_t(FOR_SHELL);
8709 /* Initialize some more globals to non-zero values */
8710 cmdedit_update_prompt();
8712 die_func = restore_ttypgrp_and__exit;
8714 /* Shell is non-interactive at first. We need to call
8715 * install_special_sighandlers() if we are going to execute "sh <script>",
8716 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8717 * If we later decide that we are interactive, we run install_special_sighandlers()
8718 * in order to intercept (more) signals.
8722 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8723 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8726 opt = getopt(argc, argv, "+c:exinsl"
8729 # if ENABLE_HUSH_FUNCTIONS
8739 * sh ... -c 'script'
8740 * sh ... -c 'script' ARG0 [ARG1...]
8741 * On NOMMU, if builtin_argc != 0,
8742 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8743 * "" needs to be replaced with NULL
8744 * and BARGV vector fed to builtin function.
8745 * Note: the form without ARG0 never happens:
8746 * sh ... -c 'builtin' BARGV... ""
8749 G.root_pid = getpid();
8750 G.root_ppid = getppid();
8752 G.global_argv = argv + optind;
8753 G.global_argc = argc - optind;
8755 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8756 const struct built_in_command *x;
8758 install_special_sighandlers();
8759 x = find_builtin(optarg);
8760 if (x) { /* paranoia */
8761 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8762 G.global_argv += builtin_argc;
8763 G.global_argv[-1] = NULL; /* replace "" */
8765 G.last_exitcode = x->b_function(argv + optind - 1);
8769 if (!G.global_argv[0]) {
8770 /* -c 'script' (no params): prevent empty $0 */
8771 G.global_argv--; /* points to argv[i] of 'script' */
8772 G.global_argv[0] = argv[0];
8774 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8775 install_special_sighandlers();
8776 parse_and_run_string(optarg);
8779 /* Well, we cannot just declare interactiveness,
8780 * we have to have some stuff (ctty, etc) */
8781 /* G_interactive_fd++; */
8784 /* "-s" means "read from stdin", but this is how we always
8785 * operate, so simply do nothing here. */
8791 case '<': /* "big heredoc" support */
8792 full_write1_str(optarg);
8795 unsigned long long empty_trap_mask;
8797 G.root_pid = bb_strtou(optarg, &optarg, 16);
8799 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8801 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8803 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8805 builtin_argc = bb_strtou(optarg, &optarg, 16);
8807 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8808 if (empty_trap_mask != 0) {
8809 IF_HUSH_TRAP(int sig;)
8810 install_special_sighandlers();
8811 # if ENABLE_HUSH_TRAP
8812 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8813 for (sig = 1; sig < NSIG; sig++) {
8814 if (empty_trap_mask & (1LL << sig)) {
8815 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8816 install_sighandler(sig, SIG_IGN);
8821 # if ENABLE_HUSH_LOOPS
8823 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8829 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8831 # if ENABLE_HUSH_FUNCTIONS
8833 struct function *funcp = new_function(optarg);
8834 /* funcp->name is already set to optarg */
8835 /* funcp->body is set to NULL. It's a special case. */
8836 funcp->body_as_string = argv[optind];
8845 if (set_mode(1, opt, NULL) == 0) /* no error */
8849 fprintf(stderr, "Usage: sh [FILE]...\n"
8850 " or: sh -c command [args]...\n\n");
8856 } /* option parsing loop */
8858 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8859 G.global_argc = argc - (optind - 1);
8860 G.global_argv = argv + (optind - 1);
8861 G.global_argv[0] = argv[0];
8864 G.root_pid = getpid();
8865 G.root_ppid = getppid();
8868 /* If we are login shell... */
8869 if (flags & OPT_login) {
8871 debug_printf("sourcing /etc/profile\n");
8872 input = fopen_for_read("/etc/profile");
8873 if (input != NULL) {
8874 remember_FILE(input);
8875 install_special_sighandlers();
8876 parse_and_run_file(input);
8877 fclose_and_forget(input);
8879 /* bash: after sourcing /etc/profile,
8880 * tries to source (in the given order):
8881 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8882 * stopping on first found. --noprofile turns this off.
8883 * bash also sources ~/.bash_logout on exit.
8884 * If called as sh, skips .bash_XXX files.
8888 if (G.global_argv[1]) {
8891 * "bash <script>" (which is never interactive (unless -i?))
8892 * sources $BASH_ENV here (without scanning $PATH).
8893 * If called as sh, does the same but with $ENV.
8894 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8898 debug_printf("running script '%s'\n", G.global_argv[0]);
8899 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8900 input = xfopen_for_read(G.global_argv[0]);
8901 xfunc_error_retval = 1;
8902 remember_FILE(input);
8903 install_special_sighandlers();
8904 parse_and_run_file(input);
8905 #if ENABLE_FEATURE_CLEAN_UP
8906 fclose_and_forget(input);
8911 /* Up to here, shell was non-interactive. Now it may become one.
8912 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8915 /* A shell is interactive if the '-i' flag was given,
8916 * or if all of the following conditions are met:
8918 * no arguments remaining or the -s flag given
8919 * standard input is a terminal
8920 * standard output is a terminal
8921 * Refer to Posix.2, the description of the 'sh' utility.
8924 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8925 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8926 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8927 if (G_saved_tty_pgrp < 0)
8928 G_saved_tty_pgrp = 0;
8930 /* try to dup stdin to high fd#, >= 255 */
8931 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8932 if (G_interactive_fd < 0) {
8933 /* try to dup to any fd */
8934 G_interactive_fd = dup(STDIN_FILENO);
8935 if (G_interactive_fd < 0) {
8937 G_interactive_fd = 0;
8938 G_saved_tty_pgrp = 0;
8941 // TODO: track & disallow any attempts of user
8942 // to (inadvertently) close/redirect G_interactive_fd
8944 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8945 if (G_interactive_fd) {
8946 close_on_exec_on(G_interactive_fd);
8948 if (G_saved_tty_pgrp) {
8949 /* If we were run as 'hush &', sleep until we are
8950 * in the foreground (tty pgrp == our pgrp).
8951 * If we get started under a job aware app (like bash),
8952 * make sure we are now in charge so we don't fight over
8953 * who gets the foreground */
8955 pid_t shell_pgrp = getpgrp();
8956 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8957 if (G_saved_tty_pgrp == shell_pgrp)
8959 /* send TTIN to ourself (should stop us) */
8960 kill(- shell_pgrp, SIGTTIN);
8964 /* Install more signal handlers */
8965 install_special_sighandlers();
8967 if (G_saved_tty_pgrp) {
8968 /* Set other signals to restore saved_tty_pgrp */
8969 install_fatal_sighandlers();
8970 /* Put ourselves in our own process group
8971 * (bash, too, does this only if ctty is available) */
8972 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8973 /* Grab control of the terminal */
8974 tcsetpgrp(G_interactive_fd, getpid());
8976 enable_restore_tty_pgrp_on_exit();
8978 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8980 const char *hp = get_local_var_value("HISTFILE");
8982 hp = get_local_var_value("HOME");
8984 hp = concat_path_file(hp, ".hush_history");
8989 G.line_input_state->hist_file = hp;
8990 //set_local_var(xasprintf("HISTFILE=%s", ...));
8992 # if ENABLE_FEATURE_SH_HISTFILESIZE
8993 hp = get_local_var_value("HISTFILESIZE");
8994 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8999 install_special_sighandlers();
9001 #elif ENABLE_HUSH_INTERACTIVE
9002 /* No job control compiled in, only prompt/line editing */
9003 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9004 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9005 if (G_interactive_fd < 0) {
9006 /* try to dup to any fd */
9007 G_interactive_fd = dup(STDIN_FILENO);
9008 if (G_interactive_fd < 0)
9010 G_interactive_fd = 0;
9013 if (G_interactive_fd) {
9014 close_on_exec_on(G_interactive_fd);
9016 install_special_sighandlers();
9018 /* We have interactiveness code disabled */
9019 install_special_sighandlers();
9022 * if interactive but not a login shell, sources ~/.bashrc
9023 * (--norc turns this off, --rcfile <file> overrides)
9026 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9027 /* note: ash and hush share this string */
9028 printf("\n\n%s %s\n"
9029 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9032 "hush - the humble shell"
9036 parse_and_run_file(stdin);
9039 hush_exit(G.last_exitcode);
9046 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9051 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9052 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9054 int argc = string_array_len(argv);
9055 return applet_main_func(argc, argv);
9058 #if ENABLE_HUSH_TEST || BASH_TEST2
9059 static int FAST_FUNC builtin_test(char **argv)
9061 return run_applet_main(argv, test_main);
9064 #if ENABLE_HUSH_ECHO
9065 static int FAST_FUNC builtin_echo(char **argv)
9067 return run_applet_main(argv, echo_main);
9070 #if ENABLE_HUSH_PRINTF
9071 static int FAST_FUNC builtin_printf(char **argv)
9073 return run_applet_main(argv, printf_main);
9077 #if ENABLE_HUSH_HELP
9078 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9080 const struct built_in_command *x;
9083 "Built-in commands:\n"
9084 "------------------\n");
9085 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9087 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9089 return EXIT_SUCCESS;
9093 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9094 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9096 show_history(G.line_input_state);
9097 return EXIT_SUCCESS;
9101 static char **skip_dash_dash(char **argv)
9104 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9109 static int FAST_FUNC builtin_cd(char **argv)
9113 argv = skip_dash_dash(argv);
9115 if (newdir == NULL) {
9116 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9117 * bash says "bash: cd: HOME not set" and does nothing
9120 const char *home = get_local_var_value("HOME");
9121 newdir = home ? home : "/";
9123 if (chdir(newdir)) {
9124 /* Mimic bash message exactly */
9125 bb_perror_msg("cd: %s", newdir);
9126 return EXIT_FAILURE;
9128 /* Read current dir (get_cwd(1) is inside) and set PWD.
9129 * Note: do not enforce exporting. If PWD was unset or unexported,
9130 * set it again, but do not export. bash does the same.
9132 set_pwd_var(/*flag:*/ 0);
9133 return EXIT_SUCCESS;
9136 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9139 return EXIT_SUCCESS;
9142 static int FAST_FUNC builtin_eval(char **argv)
9144 int rcode = EXIT_SUCCESS;
9146 argv = skip_dash_dash(argv);
9148 char *str = expand_strvec_to_string(argv);
9150 * eval "echo Hi; done" ("done" is syntax error):
9151 * "echo Hi" will not execute too.
9153 parse_and_run_string(str);
9155 rcode = G.last_exitcode;
9160 static int FAST_FUNC builtin_exec(char **argv)
9162 argv = skip_dash_dash(argv);
9163 if (argv[0] == NULL)
9164 return EXIT_SUCCESS; /* bash does this */
9166 /* Careful: we can end up here after [v]fork. Do not restore
9167 * tty pgrp then, only top-level shell process does that */
9168 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9169 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9171 /* TODO: if exec fails, bash does NOT exit! We do.
9172 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9173 * and tcsetpgrp, and this is inherently racy.
9175 execvp_or_die(argv);
9178 static int FAST_FUNC builtin_exit(char **argv)
9180 debug_printf_exec("%s()\n", __func__);
9182 /* interactive bash:
9183 * # trap "echo EEE" EXIT
9186 * There are stopped jobs.
9187 * (if there are _stopped_ jobs, running ones don't count)
9190 * EEE (then bash exits)
9192 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9195 /* note: EXIT trap is run by hush_exit */
9196 argv = skip_dash_dash(argv);
9197 if (argv[0] == NULL)
9198 hush_exit(G.last_exitcode);
9199 /* mimic bash: exit 123abc == exit 255 + error msg */
9200 xfunc_error_retval = 255;
9201 /* bash: exit -2 == exit 254, no error msg */
9202 hush_exit(xatoi(argv[0]) & 0xff);
9205 #if ENABLE_HUSH_TYPE
9206 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9207 static int FAST_FUNC builtin_type(char **argv)
9209 int ret = EXIT_SUCCESS;
9215 if (0) {} /* make conditional compile easier below */
9216 /*else if (find_alias(*argv))
9217 type = "an alias";*/
9218 #if ENABLE_HUSH_FUNCTIONS
9219 else if (find_function(*argv))
9220 type = "a function";
9222 else if (find_builtin(*argv))
9223 type = "a shell builtin";
9224 else if ((path = find_in_path(*argv)) != NULL)
9227 bb_error_msg("type: %s: not found", *argv);
9232 printf("%s is %s\n", *argv, type);
9240 #if ENABLE_HUSH_READ
9241 /* Interruptibility of read builtin in bash
9242 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9244 * Empty trap makes read ignore corresponding signal, for any signal.
9247 * - terminates non-interactive shell;
9248 * - interrupts read in interactive shell;
9249 * if it has non-empty trap:
9250 * - executes trap and returns to command prompt in interactive shell;
9251 * - executes trap and returns to read in non-interactive shell;
9253 * - is ignored (does not interrupt) read in interactive shell;
9254 * - terminates non-interactive shell;
9255 * if it has non-empty trap:
9256 * - executes trap and returns to read;
9258 * - terminates shell (regardless of interactivity);
9259 * if it has non-empty trap:
9260 * - executes trap and returns to read;
9261 * SIGCHLD from children:
9262 * - does not interrupt read regardless of interactivity:
9263 * try: sleep 1 & read x; echo $x
9265 static int FAST_FUNC builtin_read(char **argv)
9275 /* "!": do not abort on errors.
9276 * Option string must start with "sr" to match BUILTIN_READ_xxx
9278 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9279 if (read_flags == (uint32_t)-1)
9280 return EXIT_FAILURE;
9282 ifs = get_local_var_value("IFS"); /* can be NULL */
9285 r = shell_builtin_read(set_local_var_from_halves,
9295 if ((uintptr_t)r == 1 && errno == EINTR) {
9296 unsigned sig = check_and_run_traps();
9301 if ((uintptr_t)r > 1) {
9302 bb_error_msg("%s", r);
9303 r = (char*)(uintptr_t)1;
9306 return (uintptr_t)r;
9310 #if ENABLE_HUSH_UMASK
9311 static int FAST_FUNC builtin_umask(char **argv)
9318 argv = skip_dash_dash(argv);
9320 mode_t old_mask = mask;
9322 /* numeric umasks are taken as-is */
9323 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9324 if (!isdigit(argv[0][0]))
9326 mask = bb_parse_mode(argv[0], mask);
9327 if (!isdigit(argv[0][0]))
9329 if ((unsigned)mask > 0777) {
9332 * bash: umask: 'q': invalid symbolic mode operator
9333 * bash: umask: 999: octal number out of range
9335 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9340 printf("%04o\n", (unsigned) mask);
9341 /* fall through and restore mask which we set to 0 */
9345 return !rc; /* rc != 0 - success */
9349 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9350 static void print_escaped(const char *s)
9355 const char *p = strchrnul(s, '\'');
9356 /* print 'xxxx', possibly just '' */
9357 printf("'%.*s'", (int)(p - s), s);
9362 /* s points to '; print "'''...'''" */
9364 do putchar('\''); while (*++s == '\'');
9370 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9371 static int helper_export_local(char **argv, unsigned flags)
9375 char *name_end = strchrnul(name, '=');
9377 /* So far we do not check that name is valid (TODO?) */
9379 if (*name_end == '\0') {
9380 struct variable *var, **vpp;
9382 vpp = get_ptr_to_local_var(name, name_end - name);
9383 var = vpp ? *vpp : NULL;
9385 if (flags & SETFLAG_UNEXPORT) {
9386 /* export -n NAME (without =VALUE) */
9388 var->flg_export = 0;
9389 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9391 } /* else: export -n NOT_EXISTING_VAR: no-op */
9394 if (flags & SETFLAG_EXPORT) {
9395 /* export NAME (without =VALUE) */
9397 var->flg_export = 1;
9398 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9399 putenv(var->varstr);
9403 if (flags & SETFLAG_MAKE_RO) {
9404 /* readonly NAME (without =VALUE) */
9406 var->flg_read_only = 1;
9410 # if ENABLE_HUSH_LOCAL
9411 /* Is this "local" bltin? */
9412 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9413 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9414 if (var && var->func_nest_level == lvl) {
9415 /* "local x=abc; ...; local x" - ignore second local decl */
9420 /* Exporting non-existing variable.
9421 * bash does not put it in environment,
9422 * but remembers that it is exported,
9423 * and does put it in env when it is set later.
9424 * We just set it to "" and export.
9426 /* Or, it's "local NAME" (without =VALUE).
9427 * bash sets the value to "".
9429 /* Or, it's "readonly NAME" (without =VALUE).
9430 * bash remembers NAME and disallows its creation
9433 name = xasprintf("%s=", name);
9435 /* (Un)exporting/making local NAME=VALUE */
9436 name = xstrdup(name);
9438 if (set_local_var(name, flags))
9439 return EXIT_FAILURE;
9441 return EXIT_SUCCESS;
9445 #if ENABLE_HUSH_EXPORT
9446 static int FAST_FUNC builtin_export(char **argv)
9448 unsigned opt_unexport;
9450 #if ENABLE_HUSH_EXPORT_N
9451 /* "!": do not abort on errors */
9452 opt_unexport = getopt32(argv, "!n");
9453 if (opt_unexport == (uint32_t)-1)
9454 return EXIT_FAILURE;
9461 if (argv[0] == NULL) {
9468 /* ash emits: export VAR='VAL'
9469 * bash: declare -x VAR="VAL"
9470 * we follow ash example */
9471 const char *s = *e++;
9472 const char *p = strchr(s, '=');
9474 if (!p) /* wtf? take next variable */
9477 printf("export %.*s", (int)(p - s) + 1, s);
9478 print_escaped(p + 1);
9482 /*fflush_all(); - done after each builtin anyway */
9484 return EXIT_SUCCESS;
9487 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9491 #if ENABLE_HUSH_LOCAL
9492 static int FAST_FUNC builtin_local(char **argv)
9494 if (G.func_nest_level == 0) {
9495 bb_error_msg("%s: not in a function", argv[0]);
9496 return EXIT_FAILURE; /* bash compat */
9499 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9503 #if ENABLE_HUSH_READONLY
9504 static int FAST_FUNC builtin_readonly(char **argv)
9507 if (*argv == NULL) {
9508 /* bash: readonly [-p]: list all readonly VARs
9509 * (-p has no effect in bash)
9512 for (e = G.top_var; e; e = e->next) {
9513 if (e->flg_read_only) {
9514 //TODO: quote value: readonly VAR='VAL'
9515 printf("readonly %s\n", e->varstr);
9518 return EXIT_SUCCESS;
9520 return helper_export_local(argv, SETFLAG_MAKE_RO);
9524 #if ENABLE_HUSH_UNSET
9525 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9526 static int FAST_FUNC builtin_unset(char **argv)
9531 /* "!": do not abort on errors */
9532 /* "+": stop at 1st non-option */
9533 opts = getopt32(argv, "!+vf");
9534 if (opts == (unsigned)-1)
9535 return EXIT_FAILURE;
9537 bb_error_msg("unset: -v and -f are exclusive");
9538 return EXIT_FAILURE;
9544 if (!(opts & 2)) { /* not -f */
9545 if (unset_local_var(*argv)) {
9546 /* unset <nonexistent_var> doesn't fail.
9547 * Error is when one tries to unset RO var.
9548 * Message was printed by unset_local_var. */
9552 # if ENABLE_HUSH_FUNCTIONS
9564 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9565 * built-in 'set' handler
9567 * set [-abCefhmnuvx] [-o option] [argument...]
9568 * set [+abCefhmnuvx] [+o option] [argument...]
9569 * set -- [argument...]
9572 * Implementations shall support the options in both their hyphen and
9573 * plus-sign forms. These options can also be specified as options to sh.
9575 * Write out all variables and their values: set
9576 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9577 * Turn on the -x and -v options: set -xv
9578 * Unset all positional parameters: set --
9579 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9580 * Set the positional parameters to the expansion of x, even if x expands
9581 * with a leading '-' or '+': set -- $x
9583 * So far, we only support "set -- [argument...]" and some of the short names.
9585 static int FAST_FUNC builtin_set(char **argv)
9588 char **pp, **g_argv;
9589 char *arg = *++argv;
9593 for (e = G.top_var; e; e = e->next)
9595 return EXIT_SUCCESS;
9599 if (strcmp(arg, "--") == 0) {
9603 if (arg[0] != '+' && arg[0] != '-')
9605 for (n = 1; arg[n]; ++n) {
9606 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9608 if (arg[n] == 'o' && argv[1])
9611 } while ((arg = *++argv) != NULL);
9612 /* Now argv[0] is 1st argument */
9615 return EXIT_SUCCESS;
9618 /* NB: G.global_argv[0] ($0) is never freed/changed */
9619 g_argv = G.global_argv;
9620 if (G.global_args_malloced) {
9626 G.global_args_malloced = 1;
9627 pp = xzalloc(sizeof(pp[0]) * 2);
9628 pp[0] = g_argv[0]; /* retain $0 */
9631 /* This realloc's G.global_argv */
9632 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9634 G.global_argc = 1 + string_array_len(pp + 1);
9636 return EXIT_SUCCESS;
9638 /* Nothing known, so abort */
9640 bb_error_msg("set: %s: invalid option", arg);
9641 return EXIT_FAILURE;
9645 static int FAST_FUNC builtin_shift(char **argv)
9648 argv = skip_dash_dash(argv);
9650 n = bb_strtou(argv[0], NULL, 10);
9651 if (errno || n < 0) {
9652 /* shared string with ash.c */
9653 bb_error_msg("Illegal number: %s", argv[0]);
9655 * ash aborts in this case.
9656 * bash prints error message and set $? to 1.
9657 * Interestingly, for "shift 99999" bash does not
9658 * print error message, but does set $? to 1
9659 * (and does no shifting at all).
9663 if (n >= 0 && n < G.global_argc) {
9664 if (G_global_args_malloced) {
9667 free(G.global_argv[m++]);
9670 memmove(&G.global_argv[1], &G.global_argv[n+1],
9671 G.global_argc * sizeof(G.global_argv[0]));
9672 return EXIT_SUCCESS;
9674 return EXIT_FAILURE;
9677 static int FAST_FUNC builtin_source(char **argv)
9679 char *arg_path, *filename;
9682 char *args_need_save;
9683 #if ENABLE_HUSH_FUNCTIONS
9687 argv = skip_dash_dash(argv);
9690 /* bash says: "bash: .: filename argument required" */
9691 return 2; /* bash compat */
9694 if (!strchr(filename, '/')) {
9695 arg_path = find_in_path(filename);
9697 filename = arg_path;
9699 input = remember_FILE(fopen_or_warn(filename, "r"));
9702 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9703 /* POSIX: non-interactive shell should abort here,
9704 * not merely fail. So far no one complained :)
9706 return EXIT_FAILURE;
9709 #if ENABLE_HUSH_FUNCTIONS
9710 sv_flg = G_flag_return_in_progress;
9711 /* "we are inside sourced file, ok to use return" */
9712 G_flag_return_in_progress = -1;
9714 args_need_save = argv[1]; /* used as a boolean variable */
9716 save_and_replace_G_args(&sv, argv);
9718 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9719 G.last_exitcode = 0;
9720 parse_and_run_file(input);
9721 fclose_and_forget(input);
9723 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9724 restore_G_args(&sv, argv);
9725 #if ENABLE_HUSH_FUNCTIONS
9726 G_flag_return_in_progress = sv_flg;
9729 return G.last_exitcode;
9732 #if ENABLE_HUSH_TRAP
9733 static int FAST_FUNC builtin_trap(char **argv)
9739 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9744 /* No args: print all trapped */
9745 for (i = 0; i < NSIG; ++i) {
9748 print_escaped(G_traps[i]);
9749 /* note: bash adds "SIG", but only if invoked
9750 * as "bash". If called as "sh", or if set -o posix,
9751 * then it prints short signal names.
9752 * We are printing short names: */
9753 printf(" %s\n", get_signame(i));
9756 /*fflush_all(); - done after each builtin anyway */
9757 return EXIT_SUCCESS;
9761 /* If first arg is a number: reset all specified signals */
9762 sig = bb_strtou(*argv, NULL, 10);
9768 sighandler_t handler;
9770 sig = get_signum(*argv++);
9773 /* Mimic bash message exactly */
9774 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9779 G_traps[sig] = xstrdup(new_cmd);
9781 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9782 get_signame(sig), sig, G_traps[sig]);
9784 /* There is no signal for 0 (EXIT) */
9789 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9791 /* We are removing trap handler */
9792 handler = pick_sighandler(sig);
9793 install_sighandler(sig, handler);
9798 if (!argv[1]) { /* no second arg */
9799 bb_error_msg("trap: invalid arguments");
9800 return EXIT_FAILURE;
9803 /* First arg is "-": reset all specified to default */
9804 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9805 /* Everything else: set arg as signal handler
9806 * (includes "" case, which ignores signal) */
9807 if (argv[0][0] == '-') {
9808 if (argv[0][1] == '\0') { /* "-" */
9809 /* new_cmd remains NULL: "reset these sigs" */
9812 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9815 /* else: "-something", no special meaning */
9820 goto process_sig_list;
9825 static struct pipe *parse_jobspec(const char *str)
9830 if (sscanf(str, "%%%u", &jobnum) != 1) {
9832 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9834 bb_error_msg("bad argument '%s'", str);
9837 /* It is "%%", "%+" or "%" - current job */
9838 jobnum = G.last_jobid;
9840 bb_error_msg("no current job");
9844 for (pi = G.job_list; pi; pi = pi->next) {
9845 if (pi->jobid == jobnum) {
9849 bb_error_msg("%u: no such job", jobnum);
9853 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9856 const char *status_string;
9858 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9859 for (job = G.job_list; job; job = job->next) {
9860 if (job->alive_cmds == job->stopped_cmds)
9861 status_string = "Stopped";
9863 status_string = "Running";
9865 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9868 clean_up_last_dead_job();
9870 return EXIT_SUCCESS;
9873 /* built-in 'fg' and 'bg' handler */
9874 static int FAST_FUNC builtin_fg_bg(char **argv)
9879 if (!G_interactive_fd)
9880 return EXIT_FAILURE;
9882 /* If they gave us no args, assume they want the last backgrounded task */
9884 for (pi = G.job_list; pi; pi = pi->next) {
9885 if (pi->jobid == G.last_jobid) {
9889 bb_error_msg("%s: no current job", argv[0]);
9890 return EXIT_FAILURE;
9893 pi = parse_jobspec(argv[1]);
9895 return EXIT_FAILURE;
9897 /* TODO: bash prints a string representation
9898 * of job being foregrounded (like "sleep 1 | cat") */
9899 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9900 /* Put the job into the foreground. */
9901 tcsetpgrp(G_interactive_fd, pi->pgrp);
9904 /* Restart the processes in the job */
9905 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9906 for (i = 0; i < pi->num_cmds; i++) {
9907 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9909 pi->stopped_cmds = 0;
9911 i = kill(- pi->pgrp, SIGCONT);
9913 if (errno == ESRCH) {
9914 delete_finished_job(pi);
9915 return EXIT_SUCCESS;
9917 bb_perror_msg("kill (SIGCONT)");
9920 if (argv[0][0] == 'f') {
9921 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9922 return checkjobs_and_fg_shell(pi);
9924 return EXIT_SUCCESS;
9928 #if ENABLE_HUSH_KILL
9929 static int FAST_FUNC builtin_kill(char **argv)
9933 # if ENABLE_HUSH_JOB
9934 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9942 if (argv[i][0] != '%')
9945 * "kill %N" - job kill
9946 * Converting to pgrp / pid kill
9948 pi = parse_jobspec(argv[i]);
9950 /* Eat bad jobspec */
9954 argv[j - 1] = argv[j];
9961 * In jobs started under job control, we signal
9962 * entire process group by kill -PGRP_ID.
9963 * This happens, f.e., in interactive shell.
9965 * Otherwise, we signal each child via
9966 * kill PID1 PID2 PID3.
9968 * sh -c 'sleep 1|sleep 1 & kill %1'
9969 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9970 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9972 n = G_interactive_fd ? 1 : pi->num_cmds;
9973 dst = alloca(n * sizeof(int)*4);
9975 if (G_interactive_fd)
9976 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9977 else for (j = 0; j < n; j++) {
9978 struct command *cmd = &pi->cmds[j];
9979 /* Skip exited members of the job */
9983 * kill_main has matching code to expect
9984 * leading space. Needed to not confuse
9985 * negative pids with "kill -SIGNAL_NO" syntax
9987 dst += sprintf(dst, " %u", (int)cmd->pid);
9990 } while (argv[++i]);
9994 if (argv[1] || ret == 0) {
9995 ret = run_applet_main(argv, kill_main);
9997 /* else: ret = 1, "kill %bad_jobspec" case */
10002 #if ENABLE_HUSH_WAIT
10003 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10004 #if !ENABLE_HUSH_JOB
10005 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10007 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10014 if (!sigisemptyset(&G.pending_set))
10017 /* waitpid is not interruptible by SA_RESTARTed
10018 * signals which we use. Thus, this ugly dance:
10021 /* Make sure possible SIGCHLD is stored in kernel's
10022 * pending signal mask before we call waitpid.
10023 * Or else we may race with SIGCHLD, lose it,
10024 * and get stuck in sigsuspend...
10026 sigfillset(&oldset); /* block all signals, remember old set */
10027 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10029 if (!sigisemptyset(&G.pending_set)) {
10030 /* Crap! we raced with some signal! */
10034 /*errno = 0; - checkjobs does this */
10035 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10036 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10037 debug_printf_exec("checkjobs:%d\n", ret);
10038 #if ENABLE_HUSH_JOB
10039 if (waitfor_pipe) {
10040 int rcode = job_exited_or_stopped(waitfor_pipe);
10041 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10044 sigprocmask(SIG_SETMASK, &oldset, NULL);
10049 /* if ECHILD, there are no children (ret is -1 or 0) */
10050 /* if ret == 0, no children changed state */
10051 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10052 if (errno == ECHILD || ret) {
10054 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10056 sigprocmask(SIG_SETMASK, &oldset, NULL);
10059 /* Wait for SIGCHLD or any other signal */
10060 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10061 /* Note: sigsuspend invokes signal handler */
10062 sigsuspend(&oldset);
10064 sigprocmask(SIG_SETMASK, &oldset, NULL);
10066 /* So, did we get a signal? */
10067 sig = check_and_run_traps();
10068 if (sig /*&& sig != SIGCHLD - always true */) {
10072 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10077 static int FAST_FUNC builtin_wait(char **argv)
10082 argv = skip_dash_dash(argv);
10083 if (argv[0] == NULL) {
10084 /* Don't care about wait results */
10085 /* Note 1: must wait until there are no more children */
10086 /* Note 2: must be interruptible */
10088 * $ sleep 3 & sleep 6 & wait
10089 * [1] 30934 sleep 3
10090 * [2] 30935 sleep 6
10093 * $ sleep 3 & sleep 6 & wait
10094 * [1] 30936 sleep 3
10095 * [2] 30937 sleep 6
10097 * ^C <-- after ~4 sec from keyboard
10100 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10104 pid_t pid = bb_strtou(*argv, NULL, 10);
10105 if (errno || pid <= 0) {
10106 #if ENABLE_HUSH_JOB
10107 if (argv[0][0] == '%') {
10108 struct pipe *wait_pipe;
10109 ret = 127; /* bash compat for bad jobspecs */
10110 wait_pipe = parse_jobspec(*argv);
10112 ret = job_exited_or_stopped(wait_pipe);
10114 ret = wait_for_child_or_signal(wait_pipe, 0);
10116 /* waiting on "last dead job" removes it */
10117 clean_up_last_dead_job();
10120 /* else: parse_jobspec() already emitted error msg */
10124 /* mimic bash message */
10125 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10126 ret = EXIT_FAILURE;
10127 continue; /* bash checks all argv[] */
10130 /* Do we have such child? */
10131 ret = waitpid(pid, &status, WNOHANG);
10135 if (errno == ECHILD) {
10136 if (pid == G.last_bg_pid) {
10137 /* "wait $!" but last bg task has already exited. Try:
10138 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10139 * In bash it prints exitcode 0, then 3.
10140 * In dash, it is 127.
10142 ret = G.last_bg_pid_exitcode;
10144 /* Example: "wait 1". mimic bash message */
10145 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10149 bb_perror_msg("wait %s", *argv);
10151 continue; /* bash checks all argv[] */
10154 /* Yes, and it still runs */
10155 ret = wait_for_child_or_signal(NULL, pid);
10157 /* Yes, and it just exited */
10158 process_wait_result(NULL, pid, status);
10159 ret = WEXITSTATUS(status);
10160 if (WIFSIGNALED(status))
10161 ret = 128 + WTERMSIG(status);
10169 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10170 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10173 def = bb_strtou(argv[1], NULL, 10);
10174 if (errno || def < def_min || argv[2]) {
10175 bb_error_msg("%s: bad arguments", argv[0]);
10183 #if ENABLE_HUSH_LOOPS
10184 static int FAST_FUNC builtin_break(char **argv)
10187 if (G.depth_of_loop == 0) {
10188 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10189 /* if we came from builtin_continue(), need to undo "= 1" */
10190 G.flag_break_continue = 0;
10191 return EXIT_SUCCESS; /* bash compat */
10193 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10195 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10196 if (depth == UINT_MAX)
10197 G.flag_break_continue = BC_BREAK;
10198 if (G.depth_of_loop < depth)
10199 G.depth_break_continue = G.depth_of_loop;
10201 return EXIT_SUCCESS;
10204 static int FAST_FUNC builtin_continue(char **argv)
10206 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10207 return builtin_break(argv);
10211 #if ENABLE_HUSH_FUNCTIONS
10212 static int FAST_FUNC builtin_return(char **argv)
10216 if (G_flag_return_in_progress != -1) {
10217 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10218 return EXIT_FAILURE; /* bash compat */
10221 G_flag_return_in_progress = 1;
10224 * out of range: wraps around at 256, does not error out
10225 * non-numeric param:
10226 * f() { false; return qwe; }; f; echo $?
10227 * bash: return: qwe: numeric argument required <== we do this
10228 * 255 <== we also do this
10230 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10235 #if ENABLE_HUSH_MEMLEAK
10236 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10241 # ifdef M_TRIM_THRESHOLD
10242 /* Optional. Reduces probability of false positives */
10245 /* Crude attempt to find where "free memory" starts,
10246 * sans fragmentation. */
10248 l = (unsigned long)p;
10251 if (l < (unsigned long)p) l = (unsigned long)p;
10257 struct mallinfo mi = mallinfo();
10258 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10259 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10263 if (!G.memleak_value)
10264 G.memleak_value = l;
10266 l -= G.memleak_value;
10273 /* Exitcode is "how many kilobytes we leaked since 1st call" */