1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc, getopts, times:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * getopts: getopt() for shells
62 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
63 * fc -l[nr] [BEG] [END]: list range of commands in history
64 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
65 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
68 * redirection of stdout+stderr: &> and >&
69 * reserved words: function select
70 * advanced test: [[ ]]
71 * process substitution: <(list) and >(list)
74 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
75 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
76 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
78 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
79 * This is exactly equivalent to let "EXPR".
80 * $[EXPR]: synonym for $((EXPR))
81 * indirect expansion: ${!VAR}
82 * substring op on @: ${@:n:m}
85 * Some builtins mandated by standards:
86 * newgrp [GRP]: not a builtin in bash but a suid binary
87 * which spawns a new shell with new group ID
88 * In bash, export builtin is special, its arguments are assignments
89 * and therefore expansion of them should be "one-word" expansion:
90 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
92 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
93 * ls: cannot access i=a: No such file or directory
94 * ls: cannot access b: No such file or directory
95 * Note1: same applies to local builtin.
96 * Note2: bash 3.2.33(1) does this only if export word itself
98 * $ export i=`echo 'aaa bbb'`; echo "$i"
100 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
104 //config: bool "hush"
107 //config: hush is a small shell (25k). It handles the normal flow control
108 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
109 //config: case/esac. Redirections, here documents, $((arithmetic))
110 //config: and functions are supported.
112 //config: It will compile and work on no-mmu systems.
114 //config: It does not handle select, aliases, tilde expansion,
115 //config: &>file and >&file redirection of stdout+stderr.
117 //config:config HUSH_BASH_COMPAT
118 //config: bool "bash-compatible extensions"
120 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
122 //config:config HUSH_BRACE_EXPANSION
123 //config: bool "Brace expansion"
125 //config: depends on HUSH_BASH_COMPAT
127 //config: Enable {abc,def} extension.
129 //config:config HUSH_INTERACTIVE
130 //config: bool "Interactive mode"
132 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
134 //config: Enable interactive mode (prompt and command editing).
135 //config: Without this, hush simply reads and executes commands
136 //config: from stdin just like a shell script from a file.
137 //config: No prompt, no PS1/PS2 magic shell variables.
139 //config:config HUSH_SAVEHISTORY
140 //config: bool "Save command history to .hush_history"
142 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
144 //config:config HUSH_JOB
145 //config: bool "Job control"
147 //config: depends on HUSH_INTERACTIVE
149 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
150 //config: command (not entire shell), fg/bg builtins work. Without this option,
151 //config: "cmd &" still works by simply spawning a process and immediately
152 //config: prompting for next command (or executing next command in a script),
153 //config: but no separate process group is formed.
155 //config:config HUSH_TICK
156 //config: bool "Support process substitution"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable `command` and $(command).
162 //config:config HUSH_IF
163 //config: bool "Support if/then/elif/else/fi"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config:config HUSH_LOOPS
168 //config: bool "Support for, while and until loops"
170 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
172 //config:config HUSH_CASE
173 //config: bool "Support case ... esac statement"
175 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
177 //config: Enable case ... esac statement. +400 bytes.
179 //config:config HUSH_FUNCTIONS
180 //config: bool "Support funcname() { commands; } syntax"
182 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
184 //config: Enable support for shell functions. +800 bytes.
186 //config:config HUSH_LOCAL
187 //config: bool "local builtin"
189 //config: depends on HUSH_FUNCTIONS
191 //config: Enable support for local variables in functions.
193 //config:config HUSH_RANDOM_SUPPORT
194 //config: bool "Pseudorandom generator and $RANDOM variable"
196 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
198 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
199 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
201 //config:config HUSH_MODE_X
202 //config: bool "Support 'hush -x' option and 'set -x' command"
204 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
206 //config: This instructs hush to print commands before execution.
207 //config: Adds ~300 bytes.
209 //config:config HUSH_ECHO
210 //config: bool "echo builtin"
212 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
214 //config:config HUSH_PRINTF
215 //config: bool "printf builtin"
217 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
219 //config:config HUSH_TEST
220 //config: bool "test builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config:config HUSH_HELP
225 //config: bool "help builtin"
227 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
229 //config:config HUSH_EXPORT
230 //config: bool "export builtin"
232 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
234 //config:config HUSH_EXPORT_N
235 //config: bool "Support 'export -n' option"
237 //config: depends on HUSH_EXPORT
239 //config: export -n unexports variables. It is a bash extension.
241 //config:config HUSH_READONLY
242 //config: bool "readonly builtin"
244 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
246 //config: Enable support for read-only variables.
248 //config:config HUSH_KILL
249 //config: bool "kill builtin (supports kill %jobspec)"
251 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
253 //config:config HUSH_WAIT
254 //config: bool "wait builtin"
256 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
258 //config:config HUSH_TRAP
259 //config: bool "trap builtin"
261 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
263 //config:config HUSH_TYPE
264 //config: bool "type builtin"
266 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
268 //config:config HUSH_READ
269 //config: bool "read builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config:config HUSH_SET
274 //config: bool "set builtin"
276 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
278 //config:config HUSH_UNSET
279 //config: bool "unset builtin"
281 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
283 //config:config HUSH_ULIMIT
284 //config: bool "ulimit builtin"
286 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
288 //config:config HUSH_UMASK
289 //config: bool "umask builtin"
291 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
293 //config:config HUSH_MEMLEAK
294 //config: bool "memleak builtin (debugging)"
296 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
298 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
299 // APPLET_ODDNAME:name main location suid_type help
300 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
301 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
303 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
304 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
305 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
306 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
308 /* -i (interactive) and -s (read stdin) are also accepted,
309 * but currently do nothing, therefore aren't shown in help.
310 * NOMMU-specific options are not meant to be used by users,
311 * therefore we don't show them either.
313 //usage:#define hush_trivial_usage
314 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
315 //usage:#define hush_full_usage "\n\n"
316 //usage: "Unix shell interpreter"
318 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
319 || defined(__APPLE__) \
321 # include <malloc.h> /* for malloc_trim */
324 /* #include <dmalloc.h> */
326 # include <fnmatch.h>
328 #include <sys/utsname.h> /* for setting $HOSTNAME */
330 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
332 #include "shell_common.h"
335 #if ENABLE_HUSH_RANDOM_SUPPORT
338 # define CLEAR_RANDOM_T(rnd) ((void)0)
340 #ifndef F_DUPFD_CLOEXEC
341 # define F_DUPFD_CLOEXEC F_DUPFD
344 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
348 /* So far, all bash compat is controlled by one config option */
349 /* Separate defines document which part of code implements what */
350 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
351 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
352 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
353 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
354 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
358 #define LEAK_HUNTING 0
359 #define BUILD_AS_NOMMU 0
360 /* Enable/disable sanity checks. Ok to enable in production,
361 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
362 * Keeping 1 for now even in released versions.
365 /* Slightly bigger (+200 bytes), but faster hush.
366 * So far it only enables a trick with counting SIGCHLDs and forks,
367 * which allows us to do fewer waitpid's.
368 * (we can detect a case where neither forks were done nor SIGCHLDs happened
369 * and therefore waitpid will return the same result as last time)
371 #define ENABLE_HUSH_FAST 0
372 /* TODO: implement simplified code for users which do not need ${var%...} ops
373 * So far ${var%...} ops are always enabled:
375 #define ENABLE_HUSH_DOLLAR_OPS 1
380 # undef USE_FOR_NOMMU
383 # define USE_FOR_NOMMU(...) __VA_ARGS__
384 # define USE_FOR_MMU(...)
387 #include "NUM_APPLETS.h"
389 /* STANDALONE does not make sense, and won't compile */
390 # undef CONFIG_FEATURE_SH_STANDALONE
391 # undef ENABLE_FEATURE_SH_STANDALONE
392 # undef IF_FEATURE_SH_STANDALONE
393 # undef IF_NOT_FEATURE_SH_STANDALONE
394 # define ENABLE_FEATURE_SH_STANDALONE 0
395 # define IF_FEATURE_SH_STANDALONE(...)
396 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
399 #if !ENABLE_HUSH_INTERACTIVE
400 # undef ENABLE_FEATURE_EDITING
401 # define ENABLE_FEATURE_EDITING 0
402 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
403 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
404 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
405 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
408 /* Do we support ANY keywords? */
409 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 # define HAS_KEYWORDS 1
411 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
412 # define IF_HAS_NO_KEYWORDS(...)
414 # define HAS_KEYWORDS 0
415 # define IF_HAS_KEYWORDS(...)
416 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
419 /* If you comment out one of these below, it will be #defined later
420 * to perform debug printfs to stderr: */
421 #define debug_printf(...) do {} while (0)
422 /* Finer-grained debug switches */
423 #define debug_printf_parse(...) do {} while (0)
424 #define debug_print_tree(a, b) do {} while (0)
425 #define debug_printf_exec(...) do {} while (0)
426 #define debug_printf_env(...) do {} while (0)
427 #define debug_printf_jobs(...) do {} while (0)
428 #define debug_printf_expand(...) do {} while (0)
429 #define debug_printf_varexp(...) do {} while (0)
430 #define debug_printf_glob(...) do {} while (0)
431 #define debug_printf_redir(...) do {} while (0)
432 #define debug_printf_list(...) do {} while (0)
433 #define debug_printf_subst(...) do {} while (0)
434 #define debug_printf_clean(...) do {} while (0)
436 #define ERR_PTR ((void*)(long)1)
438 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
440 #define _SPECIAL_VARS_STR "_*@$!?#"
441 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
442 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
443 #if BASH_PATTERN_SUBST
444 /* Support / and // replace ops */
445 /* Note that // is stored as \ in "encoded" string representation */
446 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
447 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
448 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
450 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
451 # define VAR_SUBST_OPS "%#:-=+?"
452 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
455 #define SPECIAL_VAR_SYMBOL 3
459 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
461 /* This supports saving pointers malloced in vfork child,
462 * to be freed in the parent.
465 typedef struct nommu_save_t {
467 struct variable *old_vars;
469 char **argv_from_re_execing;
482 #if ENABLE_HUSH_LOOPS
489 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
494 /* three pseudo-keywords support contrived "case" syntax: */
495 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
496 RES_MATCH , /* "word)" */
497 RES_CASE_BODY, /* "this command is inside CASE" */
504 typedef struct o_string {
506 int length; /* position where data is appended */
509 /* At least some part of the string was inside '' or "",
510 * possibly empty one: word"", wo''rd etc. */
511 smallint has_quoted_part;
512 smallint has_empty_slot;
513 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
516 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
518 /* Protect newly added chars against globbing
519 * by prepending \ to *, ?, [, \ */
520 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
523 MAYBE_ASSIGNMENT = 0,
524 DEFINITELY_ASSIGNMENT = 1,
526 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
529 /* Used for initialization: o_string foo = NULL_O_STRING; */
530 #define NULL_O_STRING { NULL }
532 #ifndef debug_printf_parse
533 static const char *const assignment_flag[] = {
535 "DEFINITELY_ASSIGNMENT",
541 typedef struct in_str {
543 #if ENABLE_HUSH_INTERACTIVE
544 smallint promptmode; /* 0: PS1, 1: PS2 */
551 /* The descrip member of this structure is only used to make
552 * debugging output pretty */
553 static const struct {
555 signed char default_fd;
558 { O_RDONLY, 0, "<" },
559 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
560 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
561 { O_CREAT|O_RDWR, 1, "<>" },
562 { O_RDONLY, 0, "<<" },
563 /* Should not be needed. Bogus default_fd helps in debugging */
564 /* { O_RDONLY, 77, "<<" }, */
567 struct redir_struct {
568 struct redir_struct *next;
569 char *rd_filename; /* filename */
570 int rd_fd; /* fd to redirect */
571 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
573 smallint rd_type; /* (enum redir_type) */
574 /* note: for heredocs, rd_filename contains heredoc delimiter,
575 * and subsequently heredoc itself; and rd_dup is a bitmask:
576 * bit 0: do we need to trim leading tabs?
577 * bit 1: is heredoc quoted (<<'delim' syntax) ?
580 typedef enum redir_type {
582 REDIRECT_OVERWRITE = 1,
585 REDIRECT_HEREDOC = 4,
586 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
589 REDIRFD_SYNTAX_ERR = -2,
590 REDIRFD_TO_FILE = -1,
591 /* otherwise, rd_fd is redirected to rd_dup */
593 HEREDOC_SKIPTABS = 1,
599 pid_t pid; /* 0 if exited */
600 int assignment_cnt; /* how many argv[i] are assignments? */
601 smallint cmd_type; /* CMD_xxx */
603 #define CMD_SUBSHELL 1
605 /* used for "[[ EXPR ]]" */
606 # define CMD_SINGLEWORD_NOGLOB 2
608 #if ENABLE_HUSH_FUNCTIONS
609 # define CMD_FUNCDEF 3
612 smalluint cmd_exitcode;
613 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
616 char *group_as_string;
618 #if ENABLE_HUSH_FUNCTIONS
619 struct function *child_func;
620 /* This field is used to prevent a bug here:
621 * while...do f1() {a;}; f1; f1() {b;}; f1; done
622 * When we execute "f1() {a;}" cmd, we create new function and clear
623 * cmd->group, cmd->group_as_string, cmd->argv[0].
624 * When we execute "f1() {b;}", we notice that f1 exists,
625 * and that its "parent cmd" struct is still "alive",
626 * we put those fields back into cmd->xxx
627 * (struct function has ->parent_cmd ptr to facilitate that).
628 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
629 * Without this trick, loop would execute a;b;b;b;...
630 * instead of correct sequence a;b;a;b;...
631 * When command is freed, it severs the link
632 * (sets ->child_func->parent_cmd to NULL).
635 char **argv; /* command name and arguments */
636 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
637 * and on execution these are substituted with their values.
638 * Substitution can make _several_ words out of one argv[n]!
639 * Example: argv[0]=='.^C*^C.' here: echo .$*.
640 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
642 struct redir_struct *redirects; /* I/O redirections */
644 /* Is there anything in this command at all? */
645 #define IS_NULL_CMD(cmd) \
646 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
650 int num_cmds; /* total number of commands in pipe */
651 int alive_cmds; /* number of commands running (not exited) */
652 int stopped_cmds; /* number of commands alive, but stopped */
654 unsigned jobid; /* job number */
655 pid_t pgrp; /* process group ID for the job */
656 char *cmdtext; /* name of job */
658 struct command *cmds; /* array of commands in pipe */
659 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
660 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
661 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
663 typedef enum pipe_style {
669 /* Is there anything in this pipe at all? */
670 #define IS_NULL_PIPE(pi) \
671 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
673 /* This holds pointers to the various results of parsing */
674 struct parse_context {
675 /* linked list of pipes */
676 struct pipe *list_head;
677 /* last pipe (being constructed right now) */
679 /* last command in pipe (being constructed right now) */
680 struct command *command;
681 /* last redirect in command->redirects list */
682 struct redir_struct *pending_redirect;
688 smallint ctx_inverted; /* "! cmd | cmd" */
690 smallint ctx_dsemicolon; /* ";;" seen */
692 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
694 /* group we are enclosed in:
695 * example: "if pipe1; pipe2; then pipe3; fi"
696 * when we see "if" or "then", we malloc and copy current context,
697 * and make ->stack point to it. then we parse pipeN.
698 * when closing "then" / fi" / whatever is found,
699 * we move list_head into ->stack->command->group,
700 * copy ->stack into current context, and delete ->stack.
701 * (parsing of { list } and ( list ) doesn't use this method)
703 struct parse_context *stack;
707 /* On program start, environ points to initial environment.
708 * putenv adds new pointers into it, unsetenv removes them.
709 * Neither of these (de)allocates the strings.
710 * setenv allocates new strings in malloc space and does putenv,
711 * and thus setenv is unusable (leaky) for shell's purposes */
712 #define setenv(...) setenv_is_leaky_dont_use()
714 struct variable *next;
715 char *varstr; /* points to "name=" portion */
716 #if ENABLE_HUSH_LOCAL
717 unsigned func_nest_level;
719 int max_len; /* if > 0, name is part of initial env; else name is malloced */
720 smallint flg_export; /* putenv should be done on this var */
721 smallint flg_read_only;
729 #if ENABLE_HUSH_FUNCTIONS
731 struct function *next;
733 struct command *parent_cmd;
736 char *body_as_string;
742 /* set -/+o OPT support. (TODO: make it optional)
743 * bash supports the following opts:
754 * interactive-comments on
772 static const char o_opt_strings[] ALIGN1 =
776 #if ENABLE_HUSH_MODE_X
784 #if ENABLE_HUSH_MODE_X
792 struct FILE_list *next;
798 /* "Globals" within this file */
799 /* Sorted roughly by size (smaller offsets == smaller code) */
801 /* interactive_fd != 0 means we are an interactive shell.
802 * If we are, then saved_tty_pgrp can also be != 0, meaning
803 * that controlling tty is available. With saved_tty_pgrp == 0,
804 * job control still works, but terminal signals
805 * (^C, ^Z, ^Y, ^\) won't work at all, and background
806 * process groups can only be created with "cmd &".
807 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
808 * to give tty to the foreground process group,
809 * and will take it back when the group is stopped (^Z)
812 #if ENABLE_HUSH_INTERACTIVE
813 /* 'interactive_fd' is a fd# open to ctty, if we have one
814 * _AND_ if we decided to act interactively */
818 # define G_interactive_fd (G.interactive_fd)
820 # define G_interactive_fd 0
822 #if ENABLE_FEATURE_EDITING
823 line_input_t *line_input_state;
828 #if ENABLE_HUSH_RANDOM_SUPPORT
834 pid_t saved_tty_pgrp;
835 struct pipe *job_list;
836 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
838 # define G_saved_tty_pgrp 0
840 /* How deeply are we in context where "set -e" is ignored */
842 /* "set -e" rules (do we follow them correctly?):
843 * Exit if pipe, list, or compound command exits with a non-zero status.
844 * Shell does not exit if failed command is part of condition in
845 * if/while, part of && or || list except the last command, any command
846 * in a pipe but the last, or if the command's return value is being
847 * inverted with !. If a compound command other than a subshell returns a
848 * non-zero status because a command failed while -e was being ignored, the
849 * shell does not exit. A trap on ERR, if set, is executed before the shell
850 * exits [ERR is a bashism].
852 * If a compound command or function executes in a context where -e is
853 * ignored, none of the commands executed within are affected by the -e
854 * setting. If a compound command or function sets -e while executing in a
855 * context where -e is ignored, that setting does not have any effect until
856 * the compound command or the command containing the function call completes.
859 char o_opt[NUM_OPT_O];
860 #if ENABLE_HUSH_MODE_X
861 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
865 smallint flag_SIGINT;
866 #if ENABLE_HUSH_LOOPS
867 smallint flag_break_continue;
869 #if ENABLE_HUSH_FUNCTIONS
870 /* 0: outside of a function (or sourced file)
871 * -1: inside of a function, ok to use return builtin
872 * 1: return is invoked, skip all till end of func
874 smallint flag_return_in_progress;
875 # define G_flag_return_in_progress (G.flag_return_in_progress)
877 # define G_flag_return_in_progress 0
879 smallint exiting; /* used to prevent EXIT trap recursion */
880 /* These four support $?, $#, and $1 */
881 smalluint last_exitcode;
882 smalluint last_bg_pid_exitcode;
884 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
885 smalluint global_args_malloced;
886 # define G_global_args_malloced (G.global_args_malloced)
888 # define G_global_args_malloced 0
890 /* how many non-NULL argv's we have. NB: $# + 1 */
894 char *argv0_for_re_execing;
896 #if ENABLE_HUSH_LOOPS
897 unsigned depth_break_continue;
898 unsigned depth_of_loop;
902 struct variable *top_var;
903 char **expanded_assignments;
904 #if ENABLE_HUSH_FUNCTIONS
905 struct function *top_func;
906 # if ENABLE_HUSH_LOCAL
907 struct variable **shadowed_vars_pp;
908 unsigned func_nest_level;
911 /* Signal and trap handling */
913 unsigned count_SIGCHLD;
914 unsigned handled_SIGCHLD;
915 smallint we_have_children;
917 struct FILE_list *FILE_list;
918 /* Which signals have non-DFL handler (even with no traps set)?
919 * Set at the start to:
920 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
921 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
922 * The rest is cleared right before execv syscalls.
923 * Other than these two times, never modified.
925 unsigned special_sig_mask;
927 unsigned fatal_sig_mask;
928 # define G_fatal_sig_mask (G.fatal_sig_mask)
930 # define G_fatal_sig_mask 0
933 char **traps; /* char *traps[NSIG] */
934 # define G_traps G.traps
936 # define G_traps ((char**)NULL)
938 sigset_t pending_set;
939 #if ENABLE_HUSH_MEMLEAK
940 unsigned long memleak_value;
946 #if ENABLE_FEATURE_EDITING
947 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
950 #define G (*ptr_to_globals)
951 /* Not #defining name to G.name - this quickly gets unwieldy
952 * (too many defines). Also, I actually prefer to see when a variable
953 * is global, thus "G." prefix is a useful hint */
954 #define INIT_G() do { \
955 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
956 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
957 sigfillset(&G.sa.sa_mask); \
958 G.sa.sa_flags = SA_RESTART; \
962 /* Function prototypes for builtins */
963 static int builtin_cd(char **argv) FAST_FUNC;
965 static int builtin_echo(char **argv) FAST_FUNC;
967 static int builtin_eval(char **argv) FAST_FUNC;
968 static int builtin_exec(char **argv) FAST_FUNC;
969 static int builtin_exit(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_EXPORT
971 static int builtin_export(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_READONLY
974 static int builtin_readonly(char **argv) FAST_FUNC;
977 static int builtin_fg_bg(char **argv) FAST_FUNC;
978 static int builtin_jobs(char **argv) FAST_FUNC;
981 static int builtin_help(char **argv) FAST_FUNC;
983 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
984 static int builtin_history(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_LOCAL
987 static int builtin_local(char **argv) FAST_FUNC;
989 #if ENABLE_HUSH_MEMLEAK
990 static int builtin_memleak(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_PRINTF
993 static int builtin_printf(char **argv) FAST_FUNC;
995 static int builtin_pwd(char **argv) FAST_FUNC;
997 static int builtin_read(char **argv) FAST_FUNC;
1000 static int builtin_set(char **argv) FAST_FUNC;
1002 static int builtin_shift(char **argv) FAST_FUNC;
1003 static int builtin_source(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_TEST || BASH_TEST2
1005 static int builtin_test(char **argv) FAST_FUNC;
1007 #if ENABLE_HUSH_TRAP
1008 static int builtin_trap(char **argv) FAST_FUNC;
1010 #if ENABLE_HUSH_TYPE
1011 static int builtin_type(char **argv) FAST_FUNC;
1013 static int builtin_true(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_UMASK
1015 static int builtin_umask(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_UNSET
1018 static int builtin_unset(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_KILL
1021 static int builtin_kill(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_WAIT
1024 static int builtin_wait(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_LOOPS
1027 static int builtin_break(char **argv) FAST_FUNC;
1028 static int builtin_continue(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_FUNCTIONS
1031 static int builtin_return(char **argv) FAST_FUNC;
1034 /* Table of built-in functions. They can be forked or not, depending on
1035 * context: within pipes, they fork. As simple commands, they do not.
1036 * When used in non-forking context, they can change global variables
1037 * in the parent shell process. If forked, of course they cannot.
1038 * For example, 'unset foo | whatever' will parse and run, but foo will
1039 * still be set at the end. */
1040 struct built_in_command {
1042 int (*b_function)(char **argv) FAST_FUNC;
1043 #if ENABLE_HUSH_HELP
1044 const char *b_descr;
1045 # define BLTIN(cmd, func, help) { cmd, func, help }
1047 # define BLTIN(cmd, func, help) { cmd, func }
1051 static const struct built_in_command bltins1[] = {
1052 BLTIN("." , builtin_source , "Run commands in file"),
1053 BLTIN(":" , builtin_true , NULL),
1055 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1057 #if ENABLE_HUSH_LOOPS
1058 BLTIN("break" , builtin_break , "Exit loop"),
1060 BLTIN("cd" , builtin_cd , "Change directory"),
1061 #if ENABLE_HUSH_LOOPS
1062 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1064 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1065 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1066 BLTIN("exit" , builtin_exit , NULL),
1067 #if ENABLE_HUSH_EXPORT
1068 BLTIN("export" , builtin_export , "Set environment variables"),
1071 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1073 #if ENABLE_HUSH_HELP
1074 BLTIN("help" , builtin_help , NULL),
1076 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1077 BLTIN("history" , builtin_history , "Show history"),
1080 BLTIN("jobs" , builtin_jobs , "List jobs"),
1082 #if ENABLE_HUSH_KILL
1083 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1085 #if ENABLE_HUSH_LOCAL
1086 BLTIN("local" , builtin_local , "Set local variables"),
1088 #if ENABLE_HUSH_MEMLEAK
1089 BLTIN("memleak" , builtin_memleak , NULL),
1091 #if ENABLE_HUSH_READ
1092 BLTIN("read" , builtin_read , "Input into variable"),
1094 #if ENABLE_HUSH_READONLY
1095 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1097 #if ENABLE_HUSH_FUNCTIONS
1098 BLTIN("return" , builtin_return , "Return from function"),
1101 BLTIN("set" , builtin_set , "Set positional parameters"),
1103 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1105 BLTIN("source" , builtin_source , NULL),
1107 #if ENABLE_HUSH_TRAP
1108 BLTIN("trap" , builtin_trap , "Trap signals"),
1110 BLTIN("true" , builtin_true , NULL),
1111 #if ENABLE_HUSH_TYPE
1112 BLTIN("type" , builtin_type , "Show command type"),
1114 #if ENABLE_HUSH_ULIMIT
1115 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1117 #if ENABLE_HUSH_UMASK
1118 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1120 #if ENABLE_HUSH_UNSET
1121 BLTIN("unset" , builtin_unset , "Unset variables"),
1123 #if ENABLE_HUSH_WAIT
1124 BLTIN("wait" , builtin_wait , "Wait for process"),
1127 /* These builtins won't be used if we are on NOMMU and need to re-exec
1128 * (it's cheaper to run an external program in this case):
1130 static const struct built_in_command bltins2[] = {
1131 #if ENABLE_HUSH_TEST
1132 BLTIN("[" , builtin_test , NULL),
1135 BLTIN("[[" , builtin_test , NULL),
1137 #if ENABLE_HUSH_ECHO
1138 BLTIN("echo" , builtin_echo , NULL),
1140 #if ENABLE_HUSH_PRINTF
1141 BLTIN("printf" , builtin_printf , NULL),
1143 BLTIN("pwd" , builtin_pwd , NULL),
1144 #if ENABLE_HUSH_TEST
1145 BLTIN("test" , builtin_test , NULL),
1153 /* prevent disasters with G.debug_indent < 0 */
1154 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1155 # define debug_enter() (G.debug_indent++)
1156 # define debug_leave() (G.debug_indent--)
1158 # define indent() ((void)0)
1159 # define debug_enter() ((void)0)
1160 # define debug_leave() ((void)0)
1163 #ifndef debug_printf
1164 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_parse
1168 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1171 #ifndef debug_printf_exec
1172 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1175 #ifndef debug_printf_env
1176 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1179 #ifndef debug_printf_jobs
1180 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1181 # define DEBUG_JOBS 1
1183 # define DEBUG_JOBS 0
1186 #ifndef debug_printf_expand
1187 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1188 # define DEBUG_EXPAND 1
1190 # define DEBUG_EXPAND 0
1193 #ifndef debug_printf_varexp
1194 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_glob
1198 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1199 # define DEBUG_GLOB 1
1201 # define DEBUG_GLOB 0
1204 #ifndef debug_printf_redir
1205 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1208 #ifndef debug_printf_list
1209 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1212 #ifndef debug_printf_subst
1213 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1216 #ifndef debug_printf_clean
1217 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1218 # define DEBUG_CLEAN 1
1220 # define DEBUG_CLEAN 0
1224 static void debug_print_strings(const char *prefix, char **vv)
1227 fdprintf(2, "%s:\n", prefix);
1229 fdprintf(2, " '%s'\n", *vv++);
1232 # define debug_print_strings(prefix, vv) ((void)0)
1236 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1239 static void *xxmalloc(int lineno, size_t size)
1241 void *ptr = xmalloc((size + 0xff) & ~0xff);
1242 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1245 static void *xxrealloc(int lineno, void *ptr, size_t size)
1247 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1248 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1251 static char *xxstrdup(int lineno, const char *str)
1253 char *ptr = xstrdup(str);
1254 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1257 static void xxfree(void *ptr)
1259 fdprintf(2, "free %p\n", ptr);
1262 # define xmalloc(s) xxmalloc(__LINE__, s)
1263 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1264 # define xstrdup(s) xxstrdup(__LINE__, s)
1265 # define free(p) xxfree(p)
1269 /* Syntax and runtime errors. They always abort scripts.
1270 * In interactive use they usually discard unparsed and/or unexecuted commands
1271 * and return to the prompt.
1272 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1275 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(unsigned lineno, const char *fmt, ...)
1288 bb_error_msg("hush.c:%u", lineno);
1291 bb_verror_msg(fmt, p, NULL);
1293 if (!G_interactive_fd)
1297 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1300 bb_error_msg("syntax error: %s", msg);
1302 bb_error_msg("syntax error");
1305 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1307 bb_error_msg("syntax error at '%s'", msg);
1310 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1312 bb_error_msg("syntax error: unterminated %s", s);
1315 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1317 char msg[2] = { ch, '\0' };
1318 syntax_error_unterm_str(lineno, msg);
1321 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1327 bb_error_msg("hush.c:%u", lineno);
1329 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1333 # undef die_if_script
1334 # undef syntax_error
1335 # undef syntax_error_at
1336 # undef syntax_error_unterm_ch
1337 # undef syntax_error_unterm_str
1338 # undef syntax_error_unexpected_ch
1340 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1341 # define syntax_error(msg) syntax_error(__LINE__, msg)
1342 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1343 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1344 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1345 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1349 #if ENABLE_HUSH_INTERACTIVE
1350 static void cmdedit_update_prompt(void);
1352 # define cmdedit_update_prompt() ((void)0)
1356 /* Utility functions
1358 /* Replace each \x with x in place, return ptr past NUL. */
1359 static char *unbackslash(char *src)
1361 char *dst = src = strchrnul(src, '\\');
1365 if ((*dst++ = *src++) == '\0')
1371 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1392 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1393 v[count1 + count2] = NULL;
1396 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1400 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1402 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1403 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1406 #define add_strings_to_strings(strings, add, need_to_dup) \
1407 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1410 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1411 static char **add_string_to_strings(char **strings, char *add)
1416 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1419 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1421 char **ptr = add_string_to_strings(strings, add);
1422 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1425 #define add_string_to_strings(strings, add) \
1426 xx_add_string_to_strings(__LINE__, strings, add)
1429 static void free_strings(char **strings)
1443 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1447 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1457 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1461 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1467 /* fd was not open? */
1477 /* Manipulating the list of open FILEs */
1478 static FILE *remember_FILE(FILE *fp)
1481 struct FILE_list *n = xmalloc(sizeof(*n));
1482 n->next = G.FILE_list;
1486 close_on_exec_on(n->fd);
1490 static void fclose_and_forget(FILE *fp)
1492 struct FILE_list **pp = &G.FILE_list;
1494 struct FILE_list *cur = *pp;
1495 if (cur->fp == fp) {
1504 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1506 struct FILE_list *fl = G.FILE_list;
1509 /* We use it only on script files, they are all CLOEXEC */
1510 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1511 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1518 static void restore_redirected_FILEs(void)
1520 struct FILE_list *fl = G.FILE_list;
1522 int should_be = fileno(fl->fp);
1523 if (fl->fd != should_be) {
1524 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1525 xmove_fd(fl->fd, should_be);
1531 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1532 static void close_all_FILE_list(void)
1534 struct FILE_list *fl = G.FILE_list;
1536 /* fclose would also free FILE object.
1537 * It is disastrous if we share memory with a vforked parent.
1538 * I'm not sure we never come here after vfork.
1539 * Therefore just close fd, nothing more.
1541 /*fclose(fl->fp); - unsafe */
1549 /* Helpers for setting new $n and restoring them back
1551 typedef struct save_arg_t {
1555 IF_HUSH_SET(smallint sv_g_malloced;)
1558 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1560 sv->sv_argv0 = argv[0];
1561 sv->sv_g_argv = G.global_argv;
1562 sv->sv_g_argc = G.global_argc;
1563 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1565 argv[0] = G.global_argv[0]; /* retain $0 */
1566 G.global_argv = argv;
1567 IF_HUSH_SET(G.global_args_malloced = 0;)
1569 G.global_argc = 1 + string_array_len(argv + 1);
1572 static void restore_G_args(save_arg_t *sv, char **argv)
1575 if (G.global_args_malloced) {
1576 /* someone ran "set -- arg1 arg2 ...", undo */
1577 char **pp = G.global_argv;
1578 while (*++pp) /* note: does not free $0 */
1580 free(G.global_argv);
1583 argv[0] = sv->sv_argv0;
1584 G.global_argv = sv->sv_g_argv;
1585 G.global_argc = sv->sv_g_argc;
1586 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1590 /* Basic theory of signal handling in shell
1591 * ========================================
1592 * This does not describe what hush does, rather, it is current understanding
1593 * what it _should_ do. If it doesn't, it's a bug.
1594 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1596 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1597 * is finished or backgrounded. It is the same in interactive and
1598 * non-interactive shells, and is the same regardless of whether
1599 * a user trap handler is installed or a shell special one is in effect.
1600 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1601 * backgrounds (i.e. stops) or kills all members of currently running
1604 * Wait builtin is interruptible by signals for which user trap is set
1605 * or by SIGINT in interactive shell.
1607 * Trap handlers will execute even within trap handlers. (right?)
1609 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1610 * except for handlers set to '' (empty string).
1612 * If job control is off, backgrounded commands ("cmd &")
1613 * have SIGINT, SIGQUIT set to SIG_IGN.
1615 * Commands which are run in command substitution ("`cmd`")
1616 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1618 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1619 * by the shell from its parent.
1621 * Signals which differ from SIG_DFL action
1622 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1625 * SIGTERM (interactive): ignore
1626 * SIGHUP (interactive):
1627 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1628 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1629 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1630 * that all pipe members are stopped. Try this in bash:
1631 * while :; do :; done - ^Z does not background it
1632 * (while :; do :; done) - ^Z backgrounds it
1633 * SIGINT (interactive): wait for last pipe, ignore the rest
1634 * of the command line, show prompt. NB: ^C does not send SIGINT
1635 * to interactive shell while shell is waiting for a pipe,
1636 * since shell is bg'ed (is not in foreground process group).
1637 * Example 1: this waits 5 sec, but does not execute ls:
1638 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1639 * Example 2: this does not wait and does not execute ls:
1640 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1641 * Example 3: this does not wait 5 sec, but executes ls:
1642 * "sleep 5; ls -l" + press ^C
1643 * Example 4: this does not wait and does not execute ls:
1644 * "sleep 5 & wait; ls -l" + press ^C
1646 * (What happens to signals which are IGN on shell start?)
1647 * (What happens with signal mask on shell start?)
1649 * Old implementation
1650 * ==================
1651 * We use in-kernel pending signal mask to determine which signals were sent.
1652 * We block all signals which we don't want to take action immediately,
1653 * i.e. we block all signals which need to have special handling as described
1654 * above, and all signals which have traps set.
1655 * After each pipe execution, we extract any pending signals via sigtimedwait()
1658 * unsigned special_sig_mask: a mask of such "special" signals
1659 * sigset_t blocked_set: current blocked signal set
1662 * clear bit in blocked_set unless it is also in special_sig_mask
1663 * "trap 'cmd' SIGxxx":
1664 * set bit in blocked_set (even if 'cmd' is '')
1665 * after [v]fork, if we plan to be a shell:
1666 * unblock signals with special interactive handling
1667 * (child shell is not interactive),
1668 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1669 * after [v]fork, if we plan to exec:
1670 * POSIX says fork clears pending signal mask in child - no need to clear it.
1671 * Restore blocked signal set to one inherited by shell just prior to exec.
1673 * Note: as a result, we do not use signal handlers much. The only uses
1674 * are to count SIGCHLDs
1675 * and to restore tty pgrp on signal-induced exit.
1678 * Standard says "When a subshell is entered, traps that are not being ignored
1679 * are set to the default actions". bash interprets it so that traps which
1680 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1682 * Problem: the above approach makes it unwieldy to catch signals while
1683 * we are in read builtin, or while we read commands from stdin:
1684 * masked signals are not visible!
1686 * New implementation
1687 * ==================
1688 * We record each signal we are interested in by installing signal handler
1689 * for them - a bit like emulating kernel pending signal mask in userspace.
1690 * We are interested in: signals which need to have special handling
1691 * as described above, and all signals which have traps set.
1692 * Signals are recorded in pending_set.
1693 * After each pipe execution, we extract any pending signals
1696 * unsigned special_sig_mask: a mask of shell-special signals.
1697 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1698 * char *traps[sig] if trap for sig is set (even if it's '').
1699 * sigset_t pending_set: set of sigs we received.
1702 * if sig is in special_sig_mask, set handler back to:
1703 * record_pending_signo, or to IGN if it's a tty stop signal
1704 * if sig is in fatal_sig_mask, set handler back to sigexit.
1705 * else: set handler back to SIG_DFL
1706 * "trap 'cmd' SIGxxx":
1707 * set handler to record_pending_signo.
1709 * set handler to SIG_IGN.
1710 * after [v]fork, if we plan to be a shell:
1711 * set signals with special interactive handling to SIG_DFL
1712 * (because child shell is not interactive),
1713 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1714 * after [v]fork, if we plan to exec:
1715 * POSIX says fork clears pending signal mask in child - no need to clear it.
1717 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1718 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1721 * Standard says "When a subshell is entered, traps that are not being ignored
1722 * are set to the default actions". bash interprets it so that traps which
1723 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1726 SPECIAL_INTERACTIVE_SIGS = 0
1731 SPECIAL_JOBSTOP_SIGS = 0
1740 static void record_pending_signo(int sig)
1742 sigaddset(&G.pending_set, sig);
1743 #if ENABLE_HUSH_FAST
1744 if (sig == SIGCHLD) {
1746 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1751 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1753 struct sigaction old_sa;
1755 /* We could use signal() to install handlers... almost:
1756 * except that we need to mask ALL signals while handlers run.
1757 * I saw signal nesting in strace, race window isn't small.
1758 * SA_RESTART is also needed, but in Linux, signal()
1759 * sets SA_RESTART too.
1761 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1762 /* sigfillset(&G.sa.sa_mask); - already done */
1763 /* G.sa.sa_flags = SA_RESTART; - already done */
1764 G.sa.sa_handler = handler;
1765 sigaction(sig, &G.sa, &old_sa);
1766 return old_sa.sa_handler;
1769 static void hush_exit(int exitcode) NORETURN;
1771 static void restore_ttypgrp_and__exit(void) NORETURN;
1772 static void restore_ttypgrp_and__exit(void)
1774 /* xfunc has failed! die die die */
1775 /* no EXIT traps, this is an escape hatch! */
1777 hush_exit(xfunc_error_retval);
1782 /* Needed only on some libc:
1783 * It was observed that on exit(), fgetc'ed buffered data
1784 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1785 * With the net effect that even after fork(), not vfork(),
1786 * exit() in NOEXECed applet in "sh SCRIPT":
1787 * noexec_applet_here
1788 * echo END_OF_SCRIPT
1789 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1790 * This makes "echo END_OF_SCRIPT" executed twice.
1791 * Similar problems can be seen with die_if_script() -> xfunc_die()
1792 * and in `cmd` handling.
1793 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1795 static void fflush_and__exit(void) NORETURN;
1796 static void fflush_and__exit(void)
1799 _exit(xfunc_error_retval);
1802 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1803 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1804 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1805 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1807 /* Restores tty foreground process group, and exits.
1808 * May be called as signal handler for fatal signal
1809 * (will resend signal to itself, producing correct exit state)
1810 * or called directly with -EXITCODE.
1811 * We also call it if xfunc is exiting.
1813 static void sigexit(int sig) NORETURN;
1814 static void sigexit(int sig)
1816 /* Careful: we can end up here after [v]fork. Do not restore
1817 * tty pgrp then, only top-level shell process does that */
1818 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1819 /* Disable all signals: job control, SIGPIPE, etc.
1820 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1822 sigprocmask_allsigs(SIG_BLOCK);
1823 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1826 /* Not a signal, just exit */
1830 kill_myself_with_sig(sig); /* does not return */
1834 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1835 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1839 static sighandler_t pick_sighandler(unsigned sig)
1841 sighandler_t handler = SIG_DFL;
1842 if (sig < sizeof(unsigned)*8) {
1843 unsigned sigmask = (1 << sig);
1847 if (G_fatal_sig_mask & sigmask)
1851 /* sig has special handling? */
1852 if (G.special_sig_mask & sigmask) {
1853 handler = record_pending_signo;
1854 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1855 * in order to ignore them: they will be raised
1856 * in an endless loop when we try to do some
1857 * terminal ioctls! We do have to _ignore_ these.
1859 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1866 /* Restores tty foreground process group, and exits. */
1867 static void hush_exit(int exitcode)
1869 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1870 save_history(G.line_input_state);
1874 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1876 /* argv[0] is unused */
1877 argv[1] = G_traps[0];
1879 G.exiting = 1; /* prevent EXIT trap recursion */
1880 /* Note: G_traps[0] is not cleared!
1881 * "trap" will still show it, if executed
1886 #if ENABLE_FEATURE_CLEAN_UP
1888 struct variable *cur_var;
1889 if (G.cwd != bb_msg_unknown)
1891 cur_var = G.top_var;
1893 struct variable *tmp = cur_var;
1894 if (!cur_var->max_len)
1895 free(cur_var->varstr);
1896 cur_var = cur_var->next;
1904 sigexit(- (exitcode & 0xff));
1911 //TODO: return a mask of ALL handled sigs?
1912 static int check_and_run_traps(void)
1919 if (sigisemptyset(&G.pending_set))
1924 if (sigismember(&G.pending_set, sig)) {
1925 sigdelset(&G.pending_set, sig);
1928 } while (sig < NSIG);
1931 if (G_traps && G_traps[sig]) {
1932 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1933 if (G_traps[sig][0]) {
1934 /* We have user-defined handler */
1935 smalluint save_rcode;
1937 /* argv[0] is unused */
1938 argv[1] = G_traps[sig];
1940 save_rcode = G.last_exitcode;
1942 //FIXME: shouldn't it be set to 128 + sig instead?
1943 G.last_exitcode = save_rcode;
1945 } /* else: "" trap, ignoring signal */
1948 /* not a trap: special action */
1951 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1958 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1959 /* bash is observed to signal whole process groups,
1960 * not individual processes */
1961 for (job = G.job_list; job; job = job->next) {
1964 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1965 if (kill(- job->pgrp, SIGHUP) == 0)
1966 kill(- job->pgrp, SIGCONT);
1971 #if ENABLE_HUSH_FAST
1973 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1975 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1977 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1978 * This simplifies wait builtin a bit.
1982 default: /* ignored: */
1983 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1984 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1986 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1987 * Example: wait is not interrupted by TERM
1988 * in interactive shell, because TERM is ignored.
1997 static const char *get_cwd(int force)
1999 if (force || G.cwd == NULL) {
2000 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2001 * we must not try to free(bb_msg_unknown) */
2002 if (G.cwd == bb_msg_unknown)
2004 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2006 G.cwd = bb_msg_unknown;
2013 * Shell and environment variable support
2015 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2017 struct variable **pp;
2018 struct variable *cur;
2021 while ((cur = *pp) != NULL) {
2022 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2029 static const char* FAST_FUNC get_local_var_value(const char *name)
2031 struct variable **vpp;
2032 unsigned len = strlen(name);
2034 if (G.expanded_assignments) {
2035 char **cpp = G.expanded_assignments;
2038 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2039 return cp + len + 1;
2044 vpp = get_ptr_to_local_var(name, len);
2046 return (*vpp)->varstr + len + 1;
2048 if (strcmp(name, "PPID") == 0)
2049 return utoa(G.root_ppid);
2050 // bash compat: UID? EUID?
2051 #if ENABLE_HUSH_RANDOM_SUPPORT
2052 if (strcmp(name, "RANDOM") == 0)
2053 return utoa(next_random(&G.random_gen));
2058 /* str holds "NAME=VAL" and is expected to be malloced.
2059 * We take ownership of it.
2061 #define SETFLAG_EXPORT (1 << 0)
2062 #define SETFLAG_UNEXPORT (1 << 1)
2063 #define SETFLAG_MAKE_RO (1 << 2)
2064 #define SETFLAG_LOCAL_SHIFT 3
2065 static int set_local_var(char *str, unsigned flags)
2067 struct variable **var_pp;
2068 struct variable *cur;
2069 char *free_me = NULL;
2072 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2074 eq_sign = strchr(str, '=');
2075 if (!eq_sign) { /* not expected to ever happen? */
2080 name_len = eq_sign - str + 1; /* including '=' */
2081 var_pp = &G.top_var;
2082 while ((cur = *var_pp) != NULL) {
2083 if (strncmp(cur->varstr, str, name_len) != 0) {
2084 var_pp = &cur->next;
2088 /* We found an existing var with this name */
2089 if (cur->flg_read_only) {
2090 bb_error_msg("%s: readonly variable", str);
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) {
2290 bb_error_msg("%s: readonly variable", *s);
2293 /* Remove variable from global linked list */
2294 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2295 *var_pp = var_p->next;
2296 /* Add it to returned list */
2300 set_local_var(*s, SETFLAG_EXPORT);
2312 static void reinit_unicode_for_hush(void)
2314 /* Unicode support should be activated even if LANG is set
2315 * _during_ shell execution, not only if it was set when
2316 * shell was started. Therefore, re-check LANG every time:
2318 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2319 || ENABLE_UNICODE_USING_LOCALE
2321 const char *s = get_local_var_value("LC_ALL");
2322 if (!s) s = get_local_var_value("LC_CTYPE");
2323 if (!s) s = get_local_var_value("LANG");
2329 * in_str support (strings, and "strings" read from files).
2332 #if ENABLE_HUSH_INTERACTIVE
2333 /* To test correct lineedit/interactive behavior, type from command line:
2339 * It exercises a lot of corner cases.
2341 static void cmdedit_update_prompt(void)
2343 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2344 G.PS1 = get_local_var_value("PS1");
2347 G.PS2 = get_local_var_value("PS2");
2354 static const char *setup_prompt_string(int promptmode)
2356 const char *prompt_str;
2357 debug_printf("setup_prompt_string %d ", promptmode);
2358 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2359 /* Set up the prompt */
2360 if (promptmode == 0) { /* PS1 */
2362 /* bash uses $PWD value, even if it is set by user.
2363 * It uses current dir only if PWD is unset.
2364 * We always use current dir. */
2365 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2370 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2371 debug_printf("prompt_str '%s'\n", prompt_str);
2374 static int get_user_input(struct in_str *i)
2377 const char *prompt_str;
2379 prompt_str = setup_prompt_string(i->promptmode);
2380 # if ENABLE_FEATURE_EDITING
2382 reinit_unicode_for_hush();
2383 if (G.flag_SIGINT) {
2384 /* There was ^C'ed, make it look prettier: */
2388 /* buglet: SIGINT will not make new prompt to appear _at once_,
2389 * only after <Enter>. (^C works immediately) */
2390 r = read_line_input(G.line_input_state, prompt_str,
2391 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2394 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2396 write(STDOUT_FILENO, "^C", 2);
2399 check_and_run_traps();
2400 if (r != 0 && !G.flag_SIGINT)
2402 /* ^C or SIGINT: repeat */
2403 G.last_exitcode = 128 + SIGINT;
2406 /* EOF/error detected */
2408 i->peek_buf[0] = r = EOF;
2411 i->p = G.user_input_buf;
2412 return (unsigned char)*i->p++;
2416 if (i->last_char == '\0' || i->last_char == '\n') {
2417 /* Why check_and_run_traps here? Try this interactively:
2418 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2419 * $ <[enter], repeatedly...>
2420 * Without check_and_run_traps, handler never runs.
2422 check_and_run_traps();
2423 fputs(prompt_str, stdout);
2426 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2428 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2429 * no ^C masking happens during fgetc, no special code for ^C:
2430 * it generates SIGINT as usual.
2432 check_and_run_traps();
2434 G.last_exitcode = 128 + SIGINT;
2441 /* This is the magic location that prints prompts
2442 * and gets data back from the user */
2443 static int fgetc_interactive(struct in_str *i)
2446 /* If it's interactive stdin, get new line. */
2447 if (G_interactive_fd && i->file == stdin) {
2448 /* Returns first char (or EOF), the rest is in i->p[] */
2449 ch = get_user_input(i);
2450 i->promptmode = 1; /* PS2 */
2452 /* Not stdin: script file, sourced file, etc */
2453 do ch = fgetc(i->file); while (ch == '\0');
2458 static inline int fgetc_interactive(struct in_str *i)
2461 do ch = fgetc(i->file); while (ch == '\0');
2464 #endif /* INTERACTIVE */
2466 static int i_getch(struct in_str *i)
2471 /* string-based in_str */
2472 ch = (unsigned char)*i->p;
2481 /* FILE-based in_str */
2483 #if ENABLE_FEATURE_EDITING
2484 /* This can be stdin, check line editing char[] buffer */
2485 if (i->p && *i->p != '\0') {
2486 ch = (unsigned char)*i->p++;
2490 /* peek_buf[] is an int array, not char. Can contain EOF. */
2491 ch = i->peek_buf[0];
2493 int ch2 = i->peek_buf[1];
2494 i->peek_buf[0] = ch2;
2495 if (ch2 == 0) /* very likely, avoid redundant write */
2501 ch = fgetc_interactive(i);
2503 debug_printf("file_get: got '%c' %d\n", ch, ch);
2508 static int i_peek(struct in_str *i)
2513 /* string-based in_str */
2514 /* Doesn't report EOF on NUL. None of the callers care. */
2515 return (unsigned char)*i->p;
2518 /* FILE-based in_str */
2520 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2521 /* This can be stdin, check line editing char[] buffer */
2522 if (i->p && *i->p != '\0')
2523 return (unsigned char)*i->p;
2525 /* peek_buf[] is an int array, not char. Can contain EOF. */
2526 ch = i->peek_buf[0];
2530 /* Need to get a new char */
2531 ch = fgetc_interactive(i);
2532 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2534 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2535 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2541 i->peek_buf[0] = ch;
2542 /*i->peek_buf[1] = 0; - already is */
2546 /* Only ever called if i_peek() was called, and did not return EOF.
2547 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2548 * not end-of-line. Therefore we never need to read a new editing line here.
2550 static int i_peek2(struct in_str *i)
2554 /* There are two cases when i->p[] buffer exists.
2555 * (1) it's a string in_str.
2556 * (2) It's a file, and we have a saved line editing buffer.
2557 * In both cases, we know that i->p[0] exists and not NUL, and
2558 * the peek2 result is in i->p[1].
2561 return (unsigned char)i->p[1];
2563 /* Now we know it is a file-based in_str. */
2565 /* peek_buf[] is an int array, not char. Can contain EOF. */
2566 /* Is there 2nd char? */
2567 ch = i->peek_buf[1];
2569 /* We did not read it yet, get it now */
2570 do ch = fgetc(i->file); while (ch == '\0');
2571 i->peek_buf[1] = ch;
2574 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2578 static void setup_file_in_str(struct in_str *i, FILE *f)
2580 memset(i, 0, sizeof(*i));
2581 /* i->promptmode = 0; - PS1 (memset did it) */
2586 static void setup_string_in_str(struct in_str *i, const char *s)
2588 memset(i, 0, sizeof(*i));
2589 /* i->promptmode = 0; - PS1 (memset did it) */
2590 /*i->file = NULL */;
2598 #define B_CHUNK (32 * sizeof(char*))
2600 static void o_reset_to_empty_unquoted(o_string *o)
2603 o->has_quoted_part = 0;
2608 static void o_free(o_string *o)
2611 memset(o, 0, sizeof(*o));
2614 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2619 static void o_grow_by(o_string *o, int len)
2621 if (o->length + len > o->maxlen) {
2622 o->maxlen += (2 * len) | (B_CHUNK-1);
2623 o->data = xrealloc(o->data, 1 + o->maxlen);
2627 static void o_addchr(o_string *o, int ch)
2629 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2630 if (o->length < o->maxlen) {
2631 /* likely. avoid o_grow_by() call */
2633 o->data[o->length] = ch;
2635 o->data[o->length] = '\0';
2643 /* Valid only if we know o_string is not empty */
2644 static void o_delchr(o_string *o)
2647 o->data[o->length] = '\0';
2651 static void o_addblock(o_string *o, const char *str, int len)
2654 memcpy(&o->data[o->length], str, len);
2656 o->data[o->length] = '\0';
2659 static void o_addstr(o_string *o, const char *str)
2661 o_addblock(o, str, strlen(str));
2665 static void nommu_addchr(o_string *o, int ch)
2671 # define nommu_addchr(o, str) ((void)0)
2674 static void o_addstr_with_NUL(o_string *o, const char *str)
2676 o_addblock(o, str, strlen(str) + 1);
2680 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2681 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2682 * Apparently, on unquoted $v bash still does globbing
2683 * ("v='*.txt'; echo $v" prints all .txt files),
2684 * but NOT brace expansion! Thus, there should be TWO independent
2685 * quoting mechanisms on $v expansion side: one protects
2686 * $v from brace expansion, and other additionally protects "$v" against globbing.
2687 * We have only second one.
2690 #if ENABLE_HUSH_BRACE_EXPANSION
2691 # define MAYBE_BRACES "{}"
2693 # define MAYBE_BRACES ""
2696 /* My analysis of quoting semantics tells me that state information
2697 * is associated with a destination, not a source.
2699 static void o_addqchr(o_string *o, int ch)
2702 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2707 o->data[o->length] = '\\';
2710 o->data[o->length] = ch;
2712 o->data[o->length] = '\0';
2715 static void o_addQchr(o_string *o, int ch)
2718 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2719 && strchr("*?[\\" MAYBE_BRACES, ch)
2722 o->data[o->length] = '\\';
2726 o->data[o->length] = ch;
2728 o->data[o->length] = '\0';
2731 static void o_addqblock(o_string *o, const char *str, int len)
2736 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2737 if (ordinary_cnt > len) /* paranoia */
2739 o_addblock(o, str, ordinary_cnt);
2740 if (ordinary_cnt == len)
2741 return; /* NUL is already added by o_addblock */
2742 str += ordinary_cnt;
2743 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2747 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2749 o->data[o->length] = '\\';
2753 o->data[o->length] = ch;
2756 o->data[o->length] = '\0';
2759 static void o_addQblock(o_string *o, const char *str, int len)
2761 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2762 o_addblock(o, str, len);
2765 o_addqblock(o, str, len);
2768 static void o_addQstr(o_string *o, const char *str)
2770 o_addQblock(o, str, strlen(str));
2773 /* A special kind of o_string for $VAR and `cmd` expansion.
2774 * It contains char* list[] at the beginning, which is grown in 16 element
2775 * increments. Actual string data starts at the next multiple of 16 * (char*).
2776 * list[i] contains an INDEX (int!) into this string data.
2777 * It means that if list[] needs to grow, data needs to be moved higher up
2778 * but list[i]'s need not be modified.
2779 * NB: remembering how many list[i]'s you have there is crucial.
2780 * o_finalize_list() operation post-processes this structure - calculates
2781 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2783 #if DEBUG_EXPAND || DEBUG_GLOB
2784 static void debug_print_list(const char *prefix, o_string *o, int n)
2786 char **list = (char**)o->data;
2787 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2791 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2792 prefix, list, n, string_start, o->length, o->maxlen,
2793 !!(o->o_expflags & EXP_FLAG_GLOB),
2795 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2798 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2799 o->data + (int)(uintptr_t)list[i] + string_start,
2800 o->data + (int)(uintptr_t)list[i] + string_start);
2804 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2806 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2810 # define debug_print_list(prefix, o, n) ((void)0)
2813 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2814 * in list[n] so that it points past last stored byte so far.
2815 * It returns n+1. */
2816 static int o_save_ptr_helper(o_string *o, int n)
2818 char **list = (char**)o->data;
2822 if (!o->has_empty_slot) {
2823 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2824 string_len = o->length - string_start;
2825 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2826 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2827 /* list[n] points to string_start, make space for 16 more pointers */
2828 o->maxlen += 0x10 * sizeof(list[0]);
2829 o->data = xrealloc(o->data, o->maxlen + 1);
2830 list = (char**)o->data;
2831 memmove(list + n + 0x10, list + n, string_len);
2832 o->length += 0x10 * sizeof(list[0]);
2834 debug_printf_list("list[%d]=%d string_start=%d\n",
2835 n, string_len, string_start);
2838 /* We have empty slot at list[n], reuse without growth */
2839 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2840 string_len = o->length - string_start;
2841 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2842 n, string_len, string_start);
2843 o->has_empty_slot = 0;
2845 o->has_quoted_part = 0;
2846 list[n] = (char*)(uintptr_t)string_len;
2850 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2851 static int o_get_last_ptr(o_string *o, int n)
2853 char **list = (char**)o->data;
2854 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2856 return ((int)(uintptr_t)list[n-1]) + string_start;
2859 #if ENABLE_HUSH_BRACE_EXPANSION
2860 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2861 * first, it processes even {a} (no commas), second,
2862 * I didn't manage to make it return strings when they don't match
2863 * existing files. Need to re-implement it.
2867 static int glob_needed(const char *s)
2876 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2882 /* Return pointer to next closing brace or to comma */
2883 static const char *next_brace_sub(const char *cp)
2887 while (*cp != '\0') {
2894 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2900 return *cp != '\0' ? cp : NULL;
2902 /* Recursive brace globber. Note: may garble pattern[]. */
2903 static int glob_brace(char *pattern, o_string *o, int n)
2905 char *new_pattern_buf;
2912 debug_printf_glob("glob_brace('%s')\n", pattern);
2918 if (*begin == '{') {
2919 /* Find the first sub-pattern and at the same time
2920 * find the rest after the closing brace */
2921 next = next_brace_sub(begin);
2923 /* An illegal expression */
2927 /* "{abc}" with no commas - illegal
2928 * brace expr, disregard and skip it */
2934 if (*begin == '\\' && begin[1] != '\0')
2938 debug_printf_glob("begin:%s\n", begin);
2939 debug_printf_glob("next:%s\n", next);
2941 /* Now find the end of the whole brace expression */
2943 while (*rest != '}') {
2944 rest = next_brace_sub(rest);
2946 /* An illegal expression */
2949 debug_printf_glob("rest:%s\n", rest);
2951 rest_len = strlen(++rest) + 1;
2953 /* We are sure the brace expression is well-formed */
2955 /* Allocate working buffer large enough for our work */
2956 new_pattern_buf = xmalloc(strlen(pattern));
2958 /* We have a brace expression. BEGIN points to the opening {,
2959 * NEXT points past the terminator of the first element, and REST
2960 * points past the final }. We will accumulate result names from
2961 * recursive runs for each brace alternative in the buffer using
2966 /* Construct the new glob expression */
2969 mempcpy(new_pattern_buf,
2970 /* We know the prefix for all sub-patterns */
2971 pattern, begin - pattern),
2975 /* Note: glob_brace() may garble new_pattern_buf[].
2976 * That's why we re-copy prefix every time (1st memcpy above).
2978 n = glob_brace(new_pattern_buf, o, n);
2980 /* We saw the last entry */
2984 next = next_brace_sub(next);
2986 free(new_pattern_buf);
2994 memset(&globdata, 0, sizeof(globdata));
2995 gr = glob(pattern, 0, NULL, &globdata);
2996 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2998 if (gr == GLOB_NOMATCH) {
2999 globfree(&globdata);
3000 /* NB: garbles parameter */
3001 unbackslash(pattern);
3002 o_addstr_with_NUL(o, pattern);
3003 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3004 return o_save_ptr_helper(o, n);
3006 if (gr == GLOB_NOSPACE)
3007 bb_error_msg_and_die(bb_msg_memory_exhausted);
3008 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3009 * but we didn't specify it. Paranoia again. */
3010 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3012 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3013 char **argv = globdata.gl_pathv;
3015 o_addstr_with_NUL(o, *argv);
3016 n = o_save_ptr_helper(o, n);
3022 globfree(&globdata);
3026 /* Performs globbing on last list[],
3027 * saving each result as a new list[].
3029 static int perform_glob(o_string *o, int n)
3031 char *pattern, *copy;
3033 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3035 return o_save_ptr_helper(o, n);
3036 pattern = o->data + o_get_last_ptr(o, n);
3037 debug_printf_glob("glob pattern '%s'\n", pattern);
3038 if (!glob_needed(pattern)) {
3039 /* unbackslash last string in o in place, fix length */
3040 o->length = unbackslash(pattern) - o->data;
3041 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3042 return o_save_ptr_helper(o, n);
3045 copy = xstrdup(pattern);
3046 /* "forget" pattern in o */
3047 o->length = pattern - o->data;
3048 n = glob_brace(copy, o, n);
3051 debug_print_list("perform_glob returning", o, n);
3055 #else /* !HUSH_BRACE_EXPANSION */
3058 static int glob_needed(const char *s)
3067 if (*s == '*' || *s == '[' || *s == '?')
3073 /* Performs globbing on last list[],
3074 * saving each result as a new list[].
3076 static int perform_glob(o_string *o, int n)
3082 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3084 return o_save_ptr_helper(o, n);
3085 pattern = o->data + o_get_last_ptr(o, n);
3086 debug_printf_glob("glob pattern '%s'\n", pattern);
3087 if (!glob_needed(pattern)) {
3089 /* unbackslash last string in o in place, fix length */
3090 o->length = unbackslash(pattern) - o->data;
3091 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3092 return o_save_ptr_helper(o, n);
3095 memset(&globdata, 0, sizeof(globdata));
3096 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3097 * If we glob "*.\*" and don't find anything, we need
3098 * to fall back to using literal "*.*", but GLOB_NOCHECK
3099 * will return "*.\*"!
3101 gr = glob(pattern, 0, NULL, &globdata);
3102 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3104 if (gr == GLOB_NOMATCH) {
3105 globfree(&globdata);
3108 if (gr == GLOB_NOSPACE)
3109 bb_error_msg_and_die(bb_msg_memory_exhausted);
3110 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3111 * but we didn't specify it. Paranoia again. */
3112 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3114 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3115 char **argv = globdata.gl_pathv;
3116 /* "forget" pattern in o */
3117 o->length = pattern - o->data;
3119 o_addstr_with_NUL(o, *argv);
3120 n = o_save_ptr_helper(o, n);
3126 globfree(&globdata);
3128 debug_print_list("perform_glob returning", o, n);
3132 #endif /* !HUSH_BRACE_EXPANSION */
3134 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3135 * Otherwise, just finish current list[] and start new */
3136 static int o_save_ptr(o_string *o, int n)
3138 if (o->o_expflags & EXP_FLAG_GLOB) {
3139 /* If o->has_empty_slot, list[n] was already globbed
3140 * (if it was requested back then when it was filled)
3141 * so don't do that again! */
3142 if (!o->has_empty_slot)
3143 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3145 return o_save_ptr_helper(o, n);
3148 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3149 static char **o_finalize_list(o_string *o, int n)
3154 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3156 debug_print_list("finalized", o, n);
3157 debug_printf_expand("finalized n:%d\n", n);
3158 list = (char**)o->data;
3159 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3163 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3168 static void free_pipe_list(struct pipe *pi);
3170 /* Returns pi->next - next pipe in the list */
3171 static struct pipe *free_pipe(struct pipe *pi)
3176 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3177 for (i = 0; i < pi->num_cmds; i++) {
3178 struct command *command;
3179 struct redir_struct *r, *rnext;
3181 command = &pi->cmds[i];
3182 debug_printf_clean(" command %d:\n", i);
3183 if (command->argv) {
3187 for (a = 0, p = command->argv; *p; a++, p++) {
3188 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3191 free_strings(command->argv);
3192 //command->argv = NULL;
3194 /* not "else if": on syntax error, we may have both! */
3195 if (command->group) {
3196 debug_printf_clean(" begin group (cmd_type:%d)\n",
3198 free_pipe_list(command->group);
3199 debug_printf_clean(" end group\n");
3200 //command->group = NULL;
3202 /* else is crucial here.
3203 * If group != NULL, child_func is meaningless */
3204 #if ENABLE_HUSH_FUNCTIONS
3205 else if (command->child_func) {
3206 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3207 command->child_func->parent_cmd = NULL;
3211 free(command->group_as_string);
3212 //command->group_as_string = NULL;
3214 for (r = command->redirects; r; r = rnext) {
3215 debug_printf_clean(" redirect %d%s",
3216 r->rd_fd, redir_table[r->rd_type].descrip);
3217 /* guard against the case >$FOO, where foo is unset or blank */
3218 if (r->rd_filename) {
3219 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3220 free(r->rd_filename);
3221 //r->rd_filename = NULL;
3223 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3227 //command->redirects = NULL;
3229 free(pi->cmds); /* children are an array, they get freed all at once */
3233 //pi->cmdtext = NULL;
3241 static void free_pipe_list(struct pipe *pi)
3245 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3247 debug_printf_clean("pipe followup code %d\n", pi->followup);
3253 /*** Parsing routines ***/
3255 #ifndef debug_print_tree
3256 static void debug_print_tree(struct pipe *pi, int lvl)
3258 static const char *const PIPE[] = {
3264 static const char *RES[] = {
3265 [RES_NONE ] = "NONE" ,
3268 [RES_THEN ] = "THEN" ,
3269 [RES_ELIF ] = "ELIF" ,
3270 [RES_ELSE ] = "ELSE" ,
3273 # if ENABLE_HUSH_LOOPS
3274 [RES_FOR ] = "FOR" ,
3275 [RES_WHILE] = "WHILE",
3276 [RES_UNTIL] = "UNTIL",
3278 [RES_DONE ] = "DONE" ,
3280 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3283 # if ENABLE_HUSH_CASE
3284 [RES_CASE ] = "CASE" ,
3285 [RES_CASE_IN ] = "CASE_IN" ,
3286 [RES_MATCH] = "MATCH",
3287 [RES_CASE_BODY] = "CASE_BODY",
3288 [RES_ESAC ] = "ESAC" ,
3290 [RES_XXXX ] = "XXXX" ,
3291 [RES_SNTX ] = "SNTX" ,
3293 static const char *const CMDTYPE[] = {
3297 # if ENABLE_HUSH_FUNCTIONS
3306 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3307 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3309 while (prn < pi->num_cmds) {
3310 struct command *command = &pi->cmds[prn];
3311 char **argv = command->argv;
3313 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3315 command->assignment_cnt);
3316 if (command->group) {
3317 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3318 CMDTYPE[command->cmd_type],
3321 , " group_as_string:", command->group_as_string
3326 debug_print_tree(command->group, lvl+1);
3330 if (argv) while (*argv) {
3331 fdprintf(2, " '%s'", *argv);
3341 #endif /* debug_print_tree */
3343 static struct pipe *new_pipe(void)
3346 pi = xzalloc(sizeof(struct pipe));
3347 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3351 /* Command (member of a pipe) is complete, or we start a new pipe
3352 * if ctx->command is NULL.
3353 * No errors possible here.
3355 static int done_command(struct parse_context *ctx)
3357 /* The command is really already in the pipe structure, so
3358 * advance the pipe counter and make a new, null command. */
3359 struct pipe *pi = ctx->pipe;
3360 struct command *command = ctx->command;
3362 #if 0 /* Instead we emit error message at run time */
3363 if (ctx->pending_redirect) {
3364 /* For example, "cmd >" (no filename to redirect to) */
3365 die_if_script("syntax error: %s", "invalid redirect");
3366 ctx->pending_redirect = NULL;
3371 if (IS_NULL_CMD(command)) {
3372 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3376 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3377 //debug_print_tree(ctx->list_head, 20);
3379 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3382 /* Only real trickiness here is that the uncommitted
3383 * command structure is not counted in pi->num_cmds. */
3384 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3385 ctx->command = command = &pi->cmds[pi->num_cmds];
3387 memset(command, 0, sizeof(*command));
3388 return pi->num_cmds; /* used only for 0/nonzero check */
3391 static void done_pipe(struct parse_context *ctx, pipe_style type)
3395 debug_printf_parse("done_pipe entered, followup %d\n", type);
3396 /* Close previous command */
3397 not_null = done_command(ctx);
3399 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3400 ctx->ctx_inverted = 0;
3401 ctx->pipe->res_word = ctx->ctx_res_w;
3403 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3404 /* Necessary since && and || have precedence over &:
3405 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3406 * in a backgrounded subshell.
3409 struct command *command;
3411 /* Is this actually this construct, all pipes end with && or ||? */
3412 pi = ctx->list_head;
3413 while (pi != ctx->pipe) {
3414 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3419 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3420 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3421 pi = xzalloc(sizeof(*pi));
3422 pi->followup = PIPE_BG;
3424 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3425 command = &pi->cmds[0];
3426 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3427 command->cmd_type = CMD_NORMAL;
3428 command->group = ctx->list_head;
3430 command->group_as_string = xstrndup(
3431 ctx->as_string.data,
3432 ctx->as_string.length - 1 /* do not copy last char, "&" */
3435 /* Replace all pipes in ctx with one newly created */
3436 ctx->list_head = ctx->pipe = pi;
3439 ctx->pipe->followup = type;
3442 /* Without this check, even just <enter> on command line generates
3443 * tree of three NOPs (!). Which is harmless but annoying.
3444 * IOW: it is safe to do it unconditionally. */
3447 || ctx->ctx_res_w == RES_FI
3449 #if ENABLE_HUSH_LOOPS
3450 || ctx->ctx_res_w == RES_DONE
3451 || ctx->ctx_res_w == RES_FOR
3452 || ctx->ctx_res_w == RES_IN
3454 #if ENABLE_HUSH_CASE
3455 || ctx->ctx_res_w == RES_ESAC
3459 debug_printf_parse("done_pipe: adding new pipe: "
3460 "not_null:%d ctx->ctx_res_w:%d\n",
3461 not_null, ctx->ctx_res_w);
3463 ctx->pipe->next = new_p;
3465 /* RES_THEN, RES_DO etc are "sticky" -
3466 * they remain set for pipes inside if/while.
3467 * This is used to control execution.
3468 * RES_FOR and RES_IN are NOT sticky (needed to support
3469 * cases where variable or value happens to match a keyword):
3471 #if ENABLE_HUSH_LOOPS
3472 if (ctx->ctx_res_w == RES_FOR
3473 || ctx->ctx_res_w == RES_IN)
3474 ctx->ctx_res_w = RES_NONE;
3476 #if ENABLE_HUSH_CASE
3477 if (ctx->ctx_res_w == RES_MATCH)
3478 ctx->ctx_res_w = RES_CASE_BODY;
3479 if (ctx->ctx_res_w == RES_CASE)
3480 ctx->ctx_res_w = RES_CASE_IN;
3482 ctx->command = NULL; /* trick done_command below */
3483 /* Create the memory for command, roughly:
3484 * ctx->pipe->cmds = new struct command;
3485 * ctx->command = &ctx->pipe->cmds[0];
3488 //debug_print_tree(ctx->list_head, 10);
3490 debug_printf_parse("done_pipe return\n");
3493 static void initialize_context(struct parse_context *ctx)
3495 memset(ctx, 0, sizeof(*ctx));
3496 ctx->pipe = ctx->list_head = new_pipe();
3497 /* Create the memory for command, roughly:
3498 * ctx->pipe->cmds = new struct command;
3499 * ctx->command = &ctx->pipe->cmds[0];
3504 /* If a reserved word is found and processed, parse context is modified
3505 * and 1 is returned.
3508 struct reserved_combo {
3511 unsigned char assignment_flag;
3515 FLAG_END = (1 << RES_NONE ),
3517 FLAG_IF = (1 << RES_IF ),
3518 FLAG_THEN = (1 << RES_THEN ),
3519 FLAG_ELIF = (1 << RES_ELIF ),
3520 FLAG_ELSE = (1 << RES_ELSE ),
3521 FLAG_FI = (1 << RES_FI ),
3523 # if ENABLE_HUSH_LOOPS
3524 FLAG_FOR = (1 << RES_FOR ),
3525 FLAG_WHILE = (1 << RES_WHILE),
3526 FLAG_UNTIL = (1 << RES_UNTIL),
3527 FLAG_DO = (1 << RES_DO ),
3528 FLAG_DONE = (1 << RES_DONE ),
3529 FLAG_IN = (1 << RES_IN ),
3531 # if ENABLE_HUSH_CASE
3532 FLAG_MATCH = (1 << RES_MATCH),
3533 FLAG_ESAC = (1 << RES_ESAC ),
3535 FLAG_START = (1 << RES_XXXX ),
3538 static const struct reserved_combo* match_reserved_word(o_string *word)
3540 /* Mostly a list of accepted follow-up reserved words.
3541 * FLAG_END means we are done with the sequence, and are ready
3542 * to turn the compound list into a command.
3543 * FLAG_START means the word must start a new compound list.
3545 static const struct reserved_combo reserved_list[] = {
3547 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3548 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3549 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3550 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3551 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3552 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3554 # if ENABLE_HUSH_LOOPS
3555 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3556 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3557 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3558 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3559 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3560 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3562 # if ENABLE_HUSH_CASE
3563 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3564 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3567 const struct reserved_combo *r;
3569 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3570 if (strcmp(word->data, r->literal) == 0)
3575 /* Return 0: not a keyword, 1: keyword
3577 static int reserved_word(o_string *word, struct parse_context *ctx)
3579 # if ENABLE_HUSH_CASE
3580 static const struct reserved_combo reserved_match = {
3581 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3584 const struct reserved_combo *r;
3586 if (word->has_quoted_part)
3588 r = match_reserved_word(word);
3592 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3593 # if ENABLE_HUSH_CASE
3594 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3595 /* "case word IN ..." - IN part starts first MATCH part */
3596 r = &reserved_match;
3599 if (r->flag == 0) { /* '!' */
3600 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3601 syntax_error("! ! command");
3602 ctx->ctx_res_w = RES_SNTX;
3604 ctx->ctx_inverted = 1;
3607 if (r->flag & FLAG_START) {
3608 struct parse_context *old;
3610 old = xmemdup(ctx, sizeof(*ctx));
3611 debug_printf_parse("push stack %p\n", old);
3612 initialize_context(ctx);
3614 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3615 syntax_error_at(word->data);
3616 ctx->ctx_res_w = RES_SNTX;
3619 /* "{...} fi" is ok. "{...} if" is not
3621 * if { echo foo; } then { echo bar; } fi */
3622 if (ctx->command->group)
3623 done_pipe(ctx, PIPE_SEQ);
3626 ctx->ctx_res_w = r->res;
3627 ctx->old_flag = r->flag;
3628 word->o_assignment = r->assignment_flag;
3629 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3631 if (ctx->old_flag & FLAG_END) {
3632 struct parse_context *old;
3634 done_pipe(ctx, PIPE_SEQ);
3635 debug_printf_parse("pop stack %p\n", ctx->stack);
3637 old->command->group = ctx->list_head;
3638 old->command->cmd_type = CMD_NORMAL;
3640 /* At this point, the compound command's string is in
3641 * ctx->as_string... except for the leading keyword!
3642 * Consider this example: "echo a | if true; then echo a; fi"
3643 * ctx->as_string will contain "true; then echo a; fi",
3644 * with "if " remaining in old->as_string!
3648 int len = old->as_string.length;
3649 /* Concatenate halves */
3650 o_addstr(&old->as_string, ctx->as_string.data);
3651 o_free_unsafe(&ctx->as_string);
3652 /* Find where leading keyword starts in first half */
3653 str = old->as_string.data + len;
3654 if (str > old->as_string.data)
3655 str--; /* skip whitespace after keyword */
3656 while (str > old->as_string.data && isalpha(str[-1]))
3658 /* Ugh, we're done with this horrid hack */
3659 old->command->group_as_string = xstrdup(str);
3660 debug_printf_parse("pop, remembering as:'%s'\n",
3661 old->command->group_as_string);
3664 *ctx = *old; /* physical copy */
3669 #endif /* HAS_KEYWORDS */
3671 /* Word is complete, look at it and update parsing context.
3672 * Normal return is 0. Syntax errors return 1.
3673 * Note: on return, word is reset, but not o_free'd!
3675 static int done_word(o_string *word, struct parse_context *ctx)
3677 struct command *command = ctx->command;
3679 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3680 if (word->length == 0 && !word->has_quoted_part) {
3681 debug_printf_parse("done_word return 0: true null, ignored\n");
3685 if (ctx->pending_redirect) {
3686 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3687 * only if run as "bash", not "sh" */
3688 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3690 * ...the word that follows the redirection operator
3691 * shall be subjected to tilde expansion, parameter expansion,
3692 * command substitution, arithmetic expansion, and quote
3693 * removal. Pathname expansion shall not be performed
3694 * on the word by a non-interactive shell; an interactive
3695 * shell may perform it, but shall do so only when
3696 * the expansion would result in one word."
3698 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3699 /* Cater for >\file case:
3700 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3701 * Same with heredocs:
3702 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3704 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3705 unbackslash(ctx->pending_redirect->rd_filename);
3706 /* Is it <<"HEREDOC"? */
3707 if (word->has_quoted_part) {
3708 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3711 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3712 ctx->pending_redirect = NULL;
3715 # if ENABLE_HUSH_CASE
3716 if (ctx->ctx_dsemicolon
3717 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3719 /* already done when ctx_dsemicolon was set to 1: */
3720 /* ctx->ctx_res_w = RES_MATCH; */
3721 ctx->ctx_dsemicolon = 0;
3724 if (!command->argv /* if it's the first word... */
3725 # if ENABLE_HUSH_LOOPS
3726 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3727 && ctx->ctx_res_w != RES_IN
3729 # if ENABLE_HUSH_CASE
3730 && ctx->ctx_res_w != RES_CASE
3733 int reserved = reserved_word(word, ctx);
3734 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3736 o_reset_to_empty_unquoted(word);
3737 debug_printf_parse("done_word return %d\n",
3738 (ctx->ctx_res_w == RES_SNTX));
3739 return (ctx->ctx_res_w == RES_SNTX);
3742 if (strcmp(word->data, "[[") == 0) {
3743 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3749 if (command->group) {
3750 /* "{ echo foo; } echo bar" - bad */
3751 syntax_error_at(word->data);
3752 debug_printf_parse("done_word return 1: syntax error, "
3753 "groups and arglists don't mix\n");
3757 /* If this word wasn't an assignment, next ones definitely
3758 * can't be assignments. Even if they look like ones. */
3759 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3760 && word->o_assignment != WORD_IS_KEYWORD
3762 word->o_assignment = NOT_ASSIGNMENT;
3764 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3765 command->assignment_cnt++;
3766 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3768 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3769 word->o_assignment = MAYBE_ASSIGNMENT;
3771 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3773 if (word->has_quoted_part
3774 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3775 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3776 /* (otherwise it's known to be not empty and is already safe) */
3778 /* exclude "$@" - it can expand to no word despite "" */
3779 char *p = word->data;
3780 while (p[0] == SPECIAL_VAR_SYMBOL
3781 && (p[1] & 0x7f) == '@'
3782 && p[2] == SPECIAL_VAR_SYMBOL
3787 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3788 debug_print_strings("word appended to argv", command->argv);
3791 #if ENABLE_HUSH_LOOPS
3792 if (ctx->ctx_res_w == RES_FOR) {
3793 if (word->has_quoted_part
3794 || !is_well_formed_var_name(command->argv[0], '\0')
3796 /* bash says just "not a valid identifier" */
3797 syntax_error("not a valid identifier in for");
3800 /* Force FOR to have just one word (variable name) */
3801 /* NB: basically, this makes hush see "for v in ..."
3802 * syntax as if it is "for v; in ...". FOR and IN become
3803 * two pipe structs in parse tree. */
3804 done_pipe(ctx, PIPE_SEQ);
3807 #if ENABLE_HUSH_CASE
3808 /* Force CASE to have just one word */
3809 if (ctx->ctx_res_w == RES_CASE) {
3810 done_pipe(ctx, PIPE_SEQ);
3814 o_reset_to_empty_unquoted(word);
3816 debug_printf_parse("done_word return 0\n");
3821 /* Peek ahead in the input to find out if we have a "&n" construct,
3822 * as in "2>&1", that represents duplicating a file descriptor.
3824 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3825 * REDIRFD_SYNTAX_ERR if syntax error,
3826 * REDIRFD_TO_FILE if no & was seen,
3827 * or the number found.
3830 #define parse_redir_right_fd(as_string, input) \
3831 parse_redir_right_fd(input)
3833 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3839 return REDIRFD_TO_FILE;
3841 ch = i_getch(input); /* get the & */
3842 nommu_addchr(as_string, ch);
3845 ch = i_getch(input);
3846 nommu_addchr(as_string, ch);
3847 return REDIRFD_CLOSE;
3851 while (ch != EOF && isdigit(ch)) {
3852 d = d*10 + (ch-'0');
3854 ch = i_getch(input);
3855 nommu_addchr(as_string, ch);
3860 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3862 bb_error_msg("ambiguous redirect");
3863 return REDIRFD_SYNTAX_ERR;
3866 /* Return code is 0 normal, 1 if a syntax error is detected
3868 static int parse_redirect(struct parse_context *ctx,
3871 struct in_str *input)
3873 struct command *command = ctx->command;
3874 struct redir_struct *redir;
3875 struct redir_struct **redirp;
3878 dup_num = REDIRFD_TO_FILE;
3879 if (style != REDIRECT_HEREDOC) {
3880 /* Check for a '>&1' type redirect */
3881 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3882 if (dup_num == REDIRFD_SYNTAX_ERR)
3885 int ch = i_peek(input);
3886 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3887 if (dup_num) { /* <<-... */
3888 ch = i_getch(input);
3889 nommu_addchr(&ctx->as_string, ch);
3894 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3895 int ch = i_peek(input);
3897 /* >|FILE redirect ("clobbering" >).
3898 * Since we do not support "set -o noclobber" yet,
3899 * >| and > are the same for now. Just eat |.
3901 ch = i_getch(input);
3902 nommu_addchr(&ctx->as_string, ch);
3906 /* Create a new redir_struct and append it to the linked list */
3907 redirp = &command->redirects;
3908 while ((redir = *redirp) != NULL) {
3909 redirp = &(redir->next);
3911 *redirp = redir = xzalloc(sizeof(*redir));
3912 /* redir->next = NULL; */
3913 /* redir->rd_filename = NULL; */
3914 redir->rd_type = style;
3915 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3917 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3918 redir_table[style].descrip);
3920 redir->rd_dup = dup_num;
3921 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3922 /* Erik had a check here that the file descriptor in question
3923 * is legit; I postpone that to "run time"
3924 * A "-" representation of "close me" shows up as a -3 here */
3925 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3926 redir->rd_fd, redir->rd_dup);
3928 #if 0 /* Instead we emit error message at run time */
3929 if (ctx->pending_redirect) {
3930 /* For example, "cmd > <file" */
3931 die_if_script("syntax error: %s", "invalid redirect");
3934 /* Set ctx->pending_redirect, so we know what to do at the
3935 * end of the next parsed word. */
3936 ctx->pending_redirect = redir;
3941 /* If a redirect is immediately preceded by a number, that number is
3942 * supposed to tell which file descriptor to redirect. This routine
3943 * looks for such preceding numbers. In an ideal world this routine
3944 * needs to handle all the following classes of redirects...
3945 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3946 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3947 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3948 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3950 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3952 * ... If n is quoted, the number shall not be recognized as part of
3953 * the redirection expression. For example:
3955 * writes the character 2 into file a"
3956 * We are getting it right by setting ->has_quoted_part on any \<char>
3958 * A -1 return means no valid number was found,
3959 * the caller should use the appropriate default for this redirection.
3961 static int redirect_opt_num(o_string *o)
3965 if (o->data == NULL)
3967 num = bb_strtou(o->data, NULL, 10);
3968 if (errno || num < 0)
3970 o_reset_to_empty_unquoted(o);
3975 #define fetch_till_str(as_string, input, word, skip_tabs) \
3976 fetch_till_str(input, word, skip_tabs)
3978 static char *fetch_till_str(o_string *as_string,
3979 struct in_str *input,
3983 o_string heredoc = NULL_O_STRING;
3985 int prev = 0; /* not \ */
3991 ch = i_getch(input);
3993 nommu_addchr(as_string, ch);
3994 if ((ch == '\n' || ch == EOF)
3995 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3997 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3998 heredoc.data[past_EOL] = '\0';
3999 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4000 return heredoc.data;
4002 while (ch == '\n') {
4003 o_addchr(&heredoc, ch);
4006 past_EOL = heredoc.length;
4008 ch = i_getch(input);
4010 nommu_addchr(as_string, ch);
4011 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4015 o_free_unsafe(&heredoc);
4018 o_addchr(&heredoc, ch);
4019 nommu_addchr(as_string, ch);
4020 if (prev == '\\' && ch == '\\')
4021 /* Correctly handle foo\\<eol> (not a line cont.) */
4022 prev = 0; /* not \ */
4028 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4029 * and load them all. There should be exactly heredoc_cnt of them.
4031 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4033 struct pipe *pi = ctx->list_head;
4035 while (pi && heredoc_cnt) {
4037 struct command *cmd = pi->cmds;
4039 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4041 cmd->argv ? cmd->argv[0] : "NONE");
4042 for (i = 0; i < pi->num_cmds; i++) {
4043 struct redir_struct *redir = cmd->redirects;
4045 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4046 i, cmd->argv ? cmd->argv[0] : "NONE");
4048 if (redir->rd_type == REDIRECT_HEREDOC) {
4051 redir->rd_type = REDIRECT_HEREDOC2;
4052 /* redir->rd_dup is (ab)used to indicate <<- */
4053 p = fetch_till_str(&ctx->as_string, input,
4054 redir->rd_filename, redir->rd_dup);
4056 syntax_error("unexpected EOF in here document");
4059 free(redir->rd_filename);
4060 redir->rd_filename = p;
4063 redir = redir->next;
4070 /* Should be 0. If it isn't, it's a parse error */
4072 bb_error_msg_and_die("heredoc BUG 2");
4078 static int run_list(struct pipe *pi);
4080 #define parse_stream(pstring, input, end_trigger) \
4081 parse_stream(input, end_trigger)
4083 static struct pipe *parse_stream(char **pstring,
4084 struct in_str *input,
4088 #if !ENABLE_HUSH_FUNCTIONS
4089 #define parse_group(dest, ctx, input, ch) \
4090 parse_group(ctx, input, ch)
4092 static int parse_group(o_string *dest, struct parse_context *ctx,
4093 struct in_str *input, int ch)
4095 /* dest contains characters seen prior to ( or {.
4096 * Typically it's empty, but for function defs,
4097 * it contains function name (without '()'). */
4098 struct pipe *pipe_list;
4100 struct command *command = ctx->command;
4102 debug_printf_parse("parse_group entered\n");
4103 #if ENABLE_HUSH_FUNCTIONS
4104 if (ch == '(' && !dest->has_quoted_part) {
4106 if (done_word(dest, ctx))
4109 goto skip; /* (... */
4110 if (command->argv[1]) { /* word word ... (... */
4111 syntax_error_unexpected_ch('(');
4114 /* it is "word(..." or "word (..." */
4116 ch = i_getch(input);
4117 while (ch == ' ' || ch == '\t');
4119 syntax_error_unexpected_ch(ch);
4122 nommu_addchr(&ctx->as_string, ch);
4124 ch = i_getch(input);
4125 while (ch == ' ' || ch == '\t' || ch == '\n');
4127 syntax_error_unexpected_ch(ch);
4130 nommu_addchr(&ctx->as_string, ch);
4131 command->cmd_type = CMD_FUNCDEF;
4136 #if 0 /* Prevented by caller */
4137 if (command->argv /* word [word]{... */
4138 || dest->length /* word{... */
4139 || dest->has_quoted_part /* ""{... */
4142 debug_printf_parse("parse_group return 1: "
4143 "syntax error, groups and arglists don't mix\n");
4148 #if ENABLE_HUSH_FUNCTIONS
4154 command->cmd_type = CMD_SUBSHELL;
4156 /* bash does not allow "{echo...", requires whitespace */
4158 if (ch != ' ' && ch != '\t' && ch != '\n'
4159 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4161 syntax_error_unexpected_ch(ch);
4165 ch = i_getch(input);
4166 nommu_addchr(&ctx->as_string, ch);
4172 # define as_string NULL
4174 char *as_string = NULL;
4176 pipe_list = parse_stream(&as_string, input, endch);
4179 o_addstr(&ctx->as_string, as_string);
4181 /* empty ()/{} or parse error? */
4182 if (!pipe_list || pipe_list == ERR_PTR) {
4183 /* parse_stream already emitted error msg */
4186 debug_printf_parse("parse_group return 1: "
4187 "parse_stream returned %p\n", pipe_list);
4190 command->group = pipe_list;
4192 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4193 command->group_as_string = as_string;
4194 debug_printf_parse("end of group, remembering as:'%s'\n",
4195 command->group_as_string);
4199 debug_printf_parse("parse_group return 0\n");
4201 /* command remains "open", available for possible redirects */
4204 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4209 ch = i_getch(input);
4212 ch2 = i_peek(input);
4215 /* backslash+newline, skip it */
4220 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4228 ch2 = i_peek2(input);
4231 /* backslash+newline, skip it */
4237 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4238 /* Subroutines for copying $(...) and `...` things */
4239 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4241 static int add_till_single_quote(o_string *dest, struct in_str *input)
4244 int ch = i_getch(input);
4246 syntax_error_unterm_ch('\'');
4254 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4255 static int add_till_double_quote(o_string *dest, struct in_str *input)
4258 int ch = i_getch(input);
4260 syntax_error_unterm_ch('"');
4265 if (ch == '\\') { /* \x. Copy both chars. */
4267 ch = i_getch(input);
4271 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4276 //if (ch == '$') ...
4279 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4281 * "Within the backquoted style of command substitution, backslash
4282 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4283 * The search for the matching backquote shall be satisfied by the first
4284 * backquote found without a preceding backslash; during this search,
4285 * if a non-escaped backquote is encountered within a shell comment,
4286 * a here-document, an embedded command substitution of the $(command)
4287 * form, or a quoted string, undefined results occur. A single-quoted
4288 * or double-quoted string that begins, but does not end, within the
4289 * "`...`" sequence produces undefined results."
4291 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4293 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4296 int ch = i_getch(input);
4300 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4301 ch = i_getch(input);
4305 && (!in_dquote || ch != '"')
4307 o_addchr(dest, '\\');
4311 syntax_error_unterm_ch('`');
4317 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4318 * quoting and nested ()s.
4319 * "With the $(command) style of command substitution, all characters
4320 * following the open parenthesis to the matching closing parenthesis
4321 * constitute the command. Any valid shell script can be used for command,
4322 * except a script consisting solely of redirections which produces
4323 * unspecified results."
4325 * echo $(echo '(TEST)' BEST) (TEST) BEST
4326 * echo $(echo 'TEST)' BEST) TEST) BEST
4327 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4329 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4330 * can contain arbitrary constructs, just like $(cmd).
4331 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4332 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4334 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4335 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4338 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4339 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4340 char end_char2 = end_ch >> 8;
4342 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4345 ch = i_getch(input);
4347 syntax_error_unterm_ch(end_ch);
4351 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4357 /* we look for closing )) of $((EXPR)) */
4358 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4359 i_getch(input); /* eat second ')' */
4364 if (ch == '(' || ch == '{') {
4365 ch = (ch == '(' ? ')' : '}');
4366 if (!add_till_closing_bracket(dest, input, ch))
4372 if (!add_till_single_quote(dest, input))
4378 if (!add_till_double_quote(dest, input))
4384 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4390 /* \x. Copy verbatim. Important for \(, \) */
4391 ch = i_getch(input);
4393 syntax_error_unterm_ch(')');
4398 /* "backslash+newline", ignore both */
4399 o_delchr(dest); /* undo insertion of '\' */
4409 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4411 /* Return code: 0 for OK, 1 for syntax error */
4413 #define parse_dollar(as_string, dest, input, quote_mask) \
4414 parse_dollar(dest, input, quote_mask)
4415 #define as_string NULL
4417 static int parse_dollar(o_string *as_string,
4419 struct in_str *input, unsigned char quote_mask)
4421 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4423 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4425 ch = i_getch(input);
4426 nommu_addchr(as_string, ch);
4428 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4430 debug_printf_parse(": '%c'\n", ch);
4431 o_addchr(dest, ch | quote_mask);
4433 ch = i_peek_and_eat_bkslash_nl(input);
4434 if (!isalnum(ch) && ch != '_') {
4435 /* End of variable name reached */
4438 ch = i_getch(input);
4439 nommu_addchr(as_string, ch);
4441 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4442 } else if (isdigit(ch)) {
4444 ch = i_getch(input);
4445 nommu_addchr(as_string, ch);
4446 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4447 debug_printf_parse(": '%c'\n", ch);
4448 o_addchr(dest, ch | quote_mask);
4449 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4450 } else switch (ch) {
4452 case '!': /* last bg pid */
4453 case '?': /* last exit code */
4454 case '#': /* number of args */
4455 case '*': /* args */
4456 case '@': /* args */
4457 goto make_one_char_var;
4459 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4461 ch = i_getch(input); /* eat '{' */
4462 nommu_addchr(as_string, ch);
4464 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4465 /* It should be ${?}, or ${#var},
4466 * or even ${?+subst} - operator acting on a special variable,
4467 * or the beginning of variable name.
4470 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4473 syntax_error_unterm_str("${name}");
4474 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4477 nommu_addchr(as_string, ch);
4480 /* It's possible to just call add_till_closing_bracket() at this point.
4481 * However, this regresses some of our testsuite cases
4482 * which check invalid constructs like ${%}.
4483 * Oh well... let's check that the var name part is fine... */
4489 debug_printf_parse(": '%c'\n", ch);
4491 ch = i_getch(input);
4492 nommu_addchr(as_string, ch);
4496 if (!isalnum(ch) && ch != '_') {
4498 unsigned char last_ch;
4499 /* handle parameter expansions
4500 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4502 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4503 goto bad_dollar_syntax;
4505 /* Eat everything until closing '}' (or ':') */
4509 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4511 /* It's ${var:N[:M]} thing */
4512 end_ch = '}' * 0x100 + ':';
4514 if (BASH_PATTERN_SUBST
4517 /* It's ${var/[/]pattern[/repl]} thing */
4518 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4520 nommu_addchr(as_string, '/');
4523 end_ch = '}' * 0x100 + '/';
4529 #if ENABLE_HUSH_DOLLAR_OPS
4530 last_ch = add_till_closing_bracket(dest, input, end_ch);
4531 if (last_ch == 0) /* error? */
4534 #error Simple code to only allow ${var} is not implemented
4537 o_addstr(as_string, dest->data + pos);
4538 o_addchr(as_string, last_ch);
4541 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4542 && (end_ch & 0xff00)
4544 /* close the first block: */
4545 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4546 /* while parsing N from ${var:N[:M]}
4547 * or pattern from ${var/[/]pattern[/repl]} */
4548 if ((end_ch & 0xff) == last_ch) {
4549 /* got ':' or '/'- parse the rest */
4554 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4555 /* it's ${var:N} - emulate :999999999 */
4556 o_addstr(dest, "999999999");
4557 } /* else: it's ${var/[/]pattern} */
4562 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4565 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4569 ch = i_getch(input);
4570 nommu_addchr(as_string, ch);
4571 # if ENABLE_FEATURE_SH_MATH
4572 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4573 ch = i_getch(input);
4574 nommu_addchr(as_string, ch);
4575 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4576 o_addchr(dest, /*quote_mask |*/ '+');
4579 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4580 return 0; /* error */
4582 o_addstr(as_string, dest->data + pos);
4583 o_addchr(as_string, ')');
4584 o_addchr(as_string, ')');
4586 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4590 # if ENABLE_HUSH_TICK
4591 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4592 o_addchr(dest, quote_mask | '`');
4595 if (!add_till_closing_bracket(dest, input, ')'))
4596 return 0; /* error */
4598 o_addstr(as_string, dest->data + pos);
4599 o_addchr(as_string, ')');
4601 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4607 ch = i_getch(input);
4608 nommu_addchr(as_string, ch);
4609 ch = i_peek_and_eat_bkslash_nl(input);
4610 if (isalnum(ch)) { /* it's $_name or $_123 */
4615 /* TODO: $_ and $-: */
4616 /* $_ Shell or shell script name; or last argument of last command
4617 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4618 * but in command's env, set to full pathname used to invoke it */
4619 /* $- Option flags set by set builtin or shell options (-i etc) */
4621 o_addQchr(dest, '$');
4623 debug_printf_parse("parse_dollar return 1 (ok)\n");
4629 # if BASH_PATTERN_SUBST
4630 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4631 encode_string(dest, input, dquote_end, process_bkslash)
4633 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4634 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4635 encode_string(dest, input, dquote_end)
4637 #define as_string NULL
4641 # if BASH_PATTERN_SUBST
4642 /* all parameters are needed, no macro tricks */
4644 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4645 encode_string(as_string, dest, input, dquote_end)
4648 static int encode_string(o_string *as_string,
4650 struct in_str *input,
4652 int process_bkslash)
4654 #if !BASH_PATTERN_SUBST
4655 const int process_bkslash = 1;
4661 ch = i_getch(input);
4663 nommu_addchr(as_string, ch);
4664 if (ch == dquote_end) { /* may be only '"' or EOF */
4665 debug_printf_parse("encode_string return 1 (ok)\n");
4668 /* note: can't move it above ch == dquote_end check! */
4670 syntax_error_unterm_ch('"');
4671 return 0; /* error */
4675 next = i_peek(input);
4677 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4678 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4679 if (process_bkslash && ch == '\\') {
4681 syntax_error("\\<eof>");
4685 * "The backslash retains its special meaning [in "..."]
4686 * only when followed by one of the following characters:
4687 * $, `, ", \, or <newline>. A double quote may be quoted
4688 * within double quotes by preceding it with a backslash."
4689 * NB: in (unquoted) heredoc, above does not apply to ",
4690 * therefore we check for it by "next == dquote_end" cond.
4692 if (next == dquote_end || strchr("$`\\\n", next)) {
4693 ch = i_getch(input); /* eat next */
4695 goto again; /* skip \<newline> */
4696 } /* else: ch remains == '\\', and we double it below: */
4697 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4698 nommu_addchr(as_string, ch);
4702 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4703 debug_printf_parse("encode_string return 0: "
4704 "parse_dollar returned 0 (error)\n");
4709 #if ENABLE_HUSH_TICK
4711 //unsigned pos = dest->length;
4712 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4713 o_addchr(dest, 0x80 | '`');
4714 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4715 return 0; /* error */
4716 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4717 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4721 o_addQchr(dest, ch);
4727 * Scan input until EOF or end_trigger char.
4728 * Return a list of pipes to execute, or NULL on EOF
4729 * or if end_trigger character is met.
4730 * On syntax error, exit if shell is not interactive,
4731 * reset parsing machinery and start parsing anew,
4732 * or return ERR_PTR.
4734 static struct pipe *parse_stream(char **pstring,
4735 struct in_str *input,
4738 struct parse_context ctx;
4739 o_string dest = NULL_O_STRING;
4742 /* Single-quote triggers a bypass of the main loop until its mate is
4743 * found. When recursing, quote state is passed in via dest->o_expflags.
4745 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4746 end_trigger ? end_trigger : 'X');
4749 /* If very first arg is "" or '', dest.data may end up NULL.
4750 * Preventing this: */
4751 o_addchr(&dest, '\0');
4754 /* We used to separate words on $IFS here. This was wrong.
4755 * $IFS is used only for word splitting when $var is expanded,
4756 * here we should use blank chars as separators, not $IFS
4759 if (MAYBE_ASSIGNMENT != 0)
4760 dest.o_assignment = MAYBE_ASSIGNMENT;
4761 initialize_context(&ctx);
4764 const char *is_blank;
4765 const char *is_special;
4769 redir_type redir_style;
4771 ch = i_getch(input);
4772 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4773 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4778 syntax_error_unterm_str("here document");
4781 if (end_trigger == ')') {
4782 syntax_error_unterm_ch('(');
4785 if (end_trigger == '}') {
4786 syntax_error_unterm_ch('{');
4790 if (done_word(&dest, &ctx)) {
4794 done_pipe(&ctx, PIPE_SEQ);
4796 /* If we got nothing... */
4797 /* (this makes bare "&" cmd a no-op.
4798 * bash says: "syntax error near unexpected token '&'") */
4799 if (pi->num_cmds == 0
4800 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4806 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4808 *pstring = ctx.as_string.data;
4810 o_free_unsafe(&ctx.as_string);
4813 debug_printf_parse("parse_stream return %p\n", pi);
4816 nommu_addchr(&ctx.as_string, ch);
4820 next = i_peek(input);
4822 is_special = "{}<>;&|()#'" /* special outside of "str" */
4823 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4824 /* Are { and } special here? */
4825 if (ctx.command->argv /* word [word]{... - non-special */
4826 || dest.length /* word{... - non-special */
4827 || dest.has_quoted_part /* ""{... - non-special */
4828 || (next != ';' /* }; - special */
4829 && next != ')' /* }) - special */
4830 && next != '(' /* {( - special */
4831 && next != '&' /* }& and }&& ... - special */
4832 && next != '|' /* }|| ... - special */
4833 && !strchr(defifs, next) /* {word - non-special */
4836 /* They are not special, skip "{}" */
4839 is_special = strchr(is_special, ch);
4840 is_blank = strchr(defifs, ch);
4842 if (!is_special && !is_blank) { /* ordinary char */
4844 o_addQchr(&dest, ch);
4845 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4846 || dest.o_assignment == WORD_IS_KEYWORD)
4848 && is_well_formed_var_name(dest.data, '=')
4850 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4851 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4857 if (done_word(&dest, &ctx)) {
4861 /* Is this a case when newline is simply ignored?
4863 * "cmd | <newline> cmd ..."
4864 * "case ... in <newline> word) ..."
4866 if (IS_NULL_CMD(ctx.command)
4867 && dest.length == 0 && !dest.has_quoted_part
4869 /* This newline can be ignored. But...
4870 * Without check #1, interactive shell
4871 * ignores even bare <newline>,
4872 * and shows the continuation prompt:
4873 * ps1_prompt$ <enter>
4874 * ps2> _ <=== wrong, should be ps1
4875 * Without check #2, "cmd & <newline>"
4876 * is similarly mistreated.
4877 * (BTW, this makes "cmd & cmd"
4878 * and "cmd && cmd" non-orthogonal.
4879 * Really, ask yourself, why
4880 * "cmd && <newline>" doesn't start
4881 * cmd but waits for more input?
4882 * The only reason is that it might be
4883 * a "cmd1 && <nl> cmd2 &" construct,
4884 * cmd1 may need to run in BG).
4886 struct pipe *pi = ctx.list_head;
4887 if (pi->num_cmds != 0 /* check #1 */
4888 && pi->followup != PIPE_BG /* check #2 */
4893 /* Treat newline as a command separator. */
4894 done_pipe(&ctx, PIPE_SEQ);
4895 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4897 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4902 dest.o_assignment = MAYBE_ASSIGNMENT;
4903 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4905 /* note: if (is_blank) continue;
4906 * will still trigger for us */
4910 /* "cmd}" or "cmd }..." without semicolon or &:
4911 * } is an ordinary char in this case, even inside { cmd; }
4912 * Pathological example: { ""}; } should exec "}" cmd
4915 if (dest.length != 0 /* word} */
4916 || dest.has_quoted_part /* ""} */
4920 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4921 /* Generally, there should be semicolon: "cmd; }"
4922 * However, bash allows to omit it if "cmd" is
4923 * a group. Examples:
4926 * { echo 0 >&2 | { echo 1; } }
4927 * { while false; do :; done }
4928 * { case a in b) ;; esac }
4930 if (ctx.command->group)
4934 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4935 /* Can't be an end of {cmd}, skip the check */
4936 goto skip_end_trigger;
4937 /* else: } does terminate a group */
4940 if (end_trigger && end_trigger == ch
4941 && (ch != ';' || heredoc_cnt == 0)
4942 #if ENABLE_HUSH_CASE
4944 || ctx.ctx_res_w != RES_MATCH
4945 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4950 /* This is technically valid:
4951 * { cat <<HERE; }; echo Ok
4955 * but we don't support this.
4956 * We require heredoc to be in enclosing {}/(),
4959 syntax_error_unterm_str("here document");
4962 if (done_word(&dest, &ctx)) {
4965 done_pipe(&ctx, PIPE_SEQ);
4966 dest.o_assignment = MAYBE_ASSIGNMENT;
4967 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4968 /* Do we sit outside of any if's, loops or case's? */
4970 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4974 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4976 *pstring = ctx.as_string.data;
4978 o_free_unsafe(&ctx.as_string);
4981 debug_printf_parse("parse_stream return %p: "
4982 "end_trigger char found\n",
4984 return ctx.list_head;
4991 /* Catch <, > before deciding whether this word is
4992 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4995 redir_fd = redirect_opt_num(&dest);
4996 if (done_word(&dest, &ctx)) {
4999 redir_style = REDIRECT_OVERWRITE;
5001 redir_style = REDIRECT_APPEND;
5002 ch = i_getch(input);
5003 nommu_addchr(&ctx.as_string, ch);
5006 else if (next == '(') {
5007 syntax_error(">(process) not supported");
5011 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5013 continue; /* back to top of while (1) */
5015 redir_fd = redirect_opt_num(&dest);
5016 if (done_word(&dest, &ctx)) {
5019 redir_style = REDIRECT_INPUT;
5021 redir_style = REDIRECT_HEREDOC;
5023 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5024 ch = i_getch(input);
5025 nommu_addchr(&ctx.as_string, ch);
5026 } else if (next == '>') {
5027 redir_style = REDIRECT_IO;
5028 ch = i_getch(input);
5029 nommu_addchr(&ctx.as_string, ch);
5032 else if (next == '(') {
5033 syntax_error("<(process) not supported");
5037 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5039 continue; /* back to top of while (1) */
5041 if (dest.length == 0 && !dest.has_quoted_part) {
5042 /* skip "#comment" */
5045 if (ch == EOF || ch == '\n')
5048 /* note: we do not add it to &ctx.as_string */
5050 nommu_addchr(&ctx.as_string, '\n');
5051 continue; /* back to top of while (1) */
5056 /* It's "\<newline>" */
5058 /* Remove trailing '\' from ctx.as_string */
5059 ctx.as_string.data[--ctx.as_string.length] = '\0';
5061 ch = i_getch(input); /* eat it */
5062 continue; /* back to top of while (1) */
5067 if (dest.o_assignment == MAYBE_ASSIGNMENT
5068 /* check that we are not in word in "a=1 2>word b=1": */
5069 && !ctx.pending_redirect
5071 /* ch is a special char and thus this word
5072 * cannot be an assignment */
5073 dest.o_assignment = NOT_ASSIGNMENT;
5074 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5077 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5080 case '#': /* non-comment #: "echo a#b" etc */
5081 o_addQchr(&dest, ch);
5085 syntax_error("\\<eof>");
5088 ch = i_getch(input);
5089 /* note: ch != '\n' (that case does not reach this place) */
5090 o_addchr(&dest, '\\');
5091 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5092 o_addchr(&dest, ch);
5093 nommu_addchr(&ctx.as_string, ch);
5094 /* Example: echo Hello \2>file
5095 * we need to know that word 2 is quoted */
5096 dest.has_quoted_part = 1;
5099 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5100 debug_printf_parse("parse_stream parse error: "
5101 "parse_dollar returned 0 (error)\n");
5106 dest.has_quoted_part = 1;
5107 if (next == '\'' && !ctx.pending_redirect) {
5108 insert_empty_quoted_str_marker:
5109 nommu_addchr(&ctx.as_string, next);
5110 i_getch(input); /* eat second ' */
5111 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5112 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5115 ch = i_getch(input);
5117 syntax_error_unterm_ch('\'');
5120 nommu_addchr(&ctx.as_string, ch);
5123 o_addqchr(&dest, ch);
5128 dest.has_quoted_part = 1;
5129 if (next == '"' && !ctx.pending_redirect)
5130 goto insert_empty_quoted_str_marker;
5131 if (dest.o_assignment == NOT_ASSIGNMENT)
5132 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5133 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5135 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5137 #if ENABLE_HUSH_TICK
5139 USE_FOR_NOMMU(unsigned pos;)
5141 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5142 o_addchr(&dest, '`');
5143 USE_FOR_NOMMU(pos = dest.length;)
5144 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5147 o_addstr(&ctx.as_string, dest.data + pos);
5148 o_addchr(&ctx.as_string, '`');
5150 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5151 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5156 #if ENABLE_HUSH_CASE
5159 if (done_word(&dest, &ctx)) {
5162 done_pipe(&ctx, PIPE_SEQ);
5163 #if ENABLE_HUSH_CASE
5164 /* Eat multiple semicolons, detect
5165 * whether it means something special */
5170 ch = i_getch(input);
5171 nommu_addchr(&ctx.as_string, ch);
5172 if (ctx.ctx_res_w == RES_CASE_BODY) {
5173 ctx.ctx_dsemicolon = 1;
5174 ctx.ctx_res_w = RES_MATCH;
5180 /* We just finished a cmd. New one may start
5181 * with an assignment */
5182 dest.o_assignment = MAYBE_ASSIGNMENT;
5183 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5186 if (done_word(&dest, &ctx)) {
5190 ch = i_getch(input);
5191 nommu_addchr(&ctx.as_string, ch);
5192 done_pipe(&ctx, PIPE_AND);
5194 done_pipe(&ctx, PIPE_BG);
5198 if (done_word(&dest, &ctx)) {
5201 #if ENABLE_HUSH_CASE
5202 if (ctx.ctx_res_w == RES_MATCH)
5203 break; /* we are in case's "word | word)" */
5205 if (next == '|') { /* || */
5206 ch = i_getch(input);
5207 nommu_addchr(&ctx.as_string, ch);
5208 done_pipe(&ctx, PIPE_OR);
5210 /* we could pick up a file descriptor choice here
5211 * with redirect_opt_num(), but bash doesn't do it.
5212 * "echo foo 2| cat" yields "foo 2". */
5217 #if ENABLE_HUSH_CASE
5218 /* "case... in [(]word)..." - skip '(' */
5219 if (ctx.ctx_res_w == RES_MATCH
5220 && ctx.command->argv == NULL /* not (word|(... */
5221 && dest.length == 0 /* not word(... */
5222 && dest.has_quoted_part == 0 /* not ""(... */
5228 if (parse_group(&dest, &ctx, input, ch) != 0) {
5233 #if ENABLE_HUSH_CASE
5234 if (ctx.ctx_res_w == RES_MATCH)
5238 /* proper use of this character is caught by end_trigger:
5239 * if we see {, we call parse_group(..., end_trigger='}')
5240 * and it will match } earlier (not here). */
5241 syntax_error_unexpected_ch(ch);
5242 G.last_exitcode = 2;
5246 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5251 G.last_exitcode = 1;
5254 struct parse_context *pctx;
5255 IF_HAS_KEYWORDS(struct parse_context *p2;)
5257 /* Clean up allocated tree.
5258 * Sample for finding leaks on syntax error recovery path.
5259 * Run it from interactive shell, watch pmap `pidof hush`.
5260 * while if false; then false; fi; do break; fi
5261 * Samples to catch leaks at execution:
5262 * while if (true | { true;}); then echo ok; fi; do break; done
5263 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5267 /* Update pipe/command counts,
5268 * otherwise freeing may miss some */
5269 done_pipe(pctx, PIPE_SEQ);
5270 debug_printf_clean("freeing list %p from ctx %p\n",
5271 pctx->list_head, pctx);
5272 debug_print_tree(pctx->list_head, 0);
5273 free_pipe_list(pctx->list_head);
5274 debug_printf_clean("freed list %p\n", pctx->list_head);
5276 o_free_unsafe(&pctx->as_string);
5278 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5282 IF_HAS_KEYWORDS(pctx = p2;)
5283 } while (HAS_KEYWORDS && pctx);
5296 /*** Execution routines ***/
5298 /* Expansion can recurse, need forward decls: */
5299 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5300 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5301 #define expand_string_to_string(str, do_unbackslash) \
5302 expand_string_to_string(str)
5304 static char *expand_string_to_string(const char *str, int do_unbackslash);
5305 #if ENABLE_HUSH_TICK
5306 static int process_command_subs(o_string *dest, const char *s);
5309 /* expand_strvec_to_strvec() takes a list of strings, expands
5310 * all variable references within and returns a pointer to
5311 * a list of expanded strings, possibly with larger number
5312 * of strings. (Think VAR="a b"; echo $VAR).
5313 * This new list is allocated as a single malloc block.
5314 * NULL-terminated list of char* pointers is at the beginning of it,
5315 * followed by strings themselves.
5316 * Caller can deallocate entire list by single free(list). */
5318 /* A horde of its helpers come first: */
5320 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5322 while (--len >= 0) {
5325 #if ENABLE_HUSH_BRACE_EXPANSION
5326 if (c == '{' || c == '}') {
5327 /* { -> \{, } -> \} */
5329 /* And now we want to add { or } and continue:
5332 * luckily, just falling through achieves this.
5338 /* \z -> \\\z; \<eol> -> \\<eol> */
5343 o_addchr(o, *str++);
5349 /* Store given string, finalizing the word and starting new one whenever
5350 * we encounter IFS char(s). This is used for expanding variable values.
5351 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5352 * Return in *ended_with_ifs:
5353 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5355 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5357 int last_is_ifs = 0;
5362 if (!*str) /* EOL - do not finalize word */
5364 word_len = strcspn(str, G.ifs);
5366 /* We have WORD_LEN leading non-IFS chars */
5367 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5368 o_addblock(output, str, word_len);
5370 /* Protect backslashes against globbing up :)
5371 * Example: "v='\*'; echo b$v" prints "b\*"
5372 * (and does not try to glob on "*")
5374 o_addblock_duplicate_backslash(output, str, word_len);
5375 /*/ Why can't we do it easier? */
5376 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5377 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5381 if (!*str) /* EOL - do not finalize word */
5385 /* We know str here points to at least one IFS char */
5387 str += strspn(str, G.ifs); /* skip IFS chars */
5388 if (!*str) /* EOL - do not finalize word */
5391 /* Start new word... but not always! */
5392 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5393 if (output->has_quoted_part
5394 /* Case "v=' a'; echo $v":
5395 * here nothing precedes the space in $v expansion,
5396 * therefore we should not finish the word
5397 * (IOW: if there *is* word to finalize, only then do it):
5399 || (n > 0 && output->data[output->length - 1])
5401 o_addchr(output, '\0');
5402 debug_print_list("expand_on_ifs", output, n);
5403 n = o_save_ptr(output, n);
5408 *ended_with_ifs = last_is_ifs;
5409 debug_print_list("expand_on_ifs[1]", output, n);
5413 /* Helper to expand $((...)) and heredoc body. These act as if
5414 * they are in double quotes, with the exception that they are not :).
5415 * Just the rules are similar: "expand only $var and `cmd`"
5417 * Returns malloced string.
5418 * As an optimization, we return NULL if expansion is not needed.
5420 #if !BASH_PATTERN_SUBST
5421 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5422 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5423 encode_then_expand_string(str)
5425 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5427 #if !BASH_PATTERN_SUBST
5428 const int do_unbackslash = 1;
5431 struct in_str input;
5432 o_string dest = NULL_O_STRING;
5434 if (!strchr(str, '$')
5435 && !strchr(str, '\\')
5436 #if ENABLE_HUSH_TICK
5437 && !strchr(str, '`')
5443 /* We need to expand. Example:
5444 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5446 setup_string_in_str(&input, str);
5447 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5448 //TODO: error check (encode_string returns 0 on error)?
5449 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5450 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5451 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5452 o_free_unsafe(&dest);
5456 #if ENABLE_FEATURE_SH_MATH
5457 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5459 arith_state_t math_state;
5463 math_state.lookupvar = get_local_var_value;
5464 math_state.setvar = set_local_var_from_halves;
5465 //math_state.endofname = endofname;
5466 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5467 res = arith(&math_state, exp_str ? exp_str : arg);
5470 *errmsg_p = math_state.errmsg;
5471 if (math_state.errmsg)
5472 die_if_script(math_state.errmsg);
5477 #if BASH_PATTERN_SUBST
5478 /* ${var/[/]pattern[/repl]} helpers */
5479 static char *strstr_pattern(char *val, const char *pattern, int *size)
5482 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5483 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5490 /* Optimization: if "*pat" did not match the start of "string",
5491 * we know that "tring", "ring" etc will not match too:
5493 if (pattern[0] == '*')
5498 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5500 char *result = NULL;
5501 unsigned res_len = 0;
5502 unsigned repl_len = strlen(repl);
5506 char *s = strstr_pattern(val, pattern, &size);
5510 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5511 memcpy(result + res_len, val, s - val);
5513 strcpy(result + res_len, repl);
5514 res_len += repl_len;
5515 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5521 if (val[0] && result) {
5522 result = xrealloc(result, res_len + strlen(val) + 1);
5523 strcpy(result + res_len, val);
5524 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5526 debug_printf_varexp("result:'%s'\n", result);
5529 #endif /* BASH_PATTERN_SUBST */
5532 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5534 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5536 const char *val = NULL;
5537 char *to_be_freed = NULL;
5542 char exp_save = exp_save; /* for compiler */
5543 char *exp_saveptr; /* points to expansion operator */
5544 char *exp_word = exp_word; /* for compiler */
5547 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5549 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5551 first_char = arg[0] = arg0 & 0x7f;
5554 if (first_char == '#' /* ${#... */
5555 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5557 /* It must be length operator: ${#var} */
5561 /* Maybe handle parameter expansion */
5562 if (exp_saveptr /* if 2nd char is one of expansion operators */
5563 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5565 /* ${?:0}, ${#[:]%0} etc */
5566 exp_saveptr = var + 1;
5568 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5569 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5571 exp_op = exp_save = *exp_saveptr;
5573 exp_word = exp_saveptr + 1;
5574 if (exp_op == ':') {
5575 exp_op = *exp_word++;
5576 //TODO: try ${var:} and ${var:bogus} in non-bash config
5578 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5580 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5585 *exp_saveptr = '\0';
5586 } /* else: it's not an expansion op, but bare ${var} */
5589 /* Look up the variable in question */
5590 if (isdigit(var[0])) {
5591 /* parse_dollar should have vetted var for us */
5592 int n = xatoi_positive(var);
5593 if (n < G.global_argc)
5594 val = G.global_argv[n];
5595 /* else val remains NULL: $N with too big N */
5599 val = utoa(G.root_pid);
5601 case '!': /* bg pid */
5602 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5604 case '?': /* exitcode */
5605 val = utoa(G.last_exitcode);
5607 case '#': /* argc */
5608 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5611 val = get_local_var_value(var);
5615 /* Handle any expansions */
5616 if (exp_op == 'L') {
5617 reinit_unicode_for_hush();
5618 debug_printf_expand("expand: length(%s)=", val);
5619 val = utoa(val ? unicode_strlen(val) : 0);
5620 debug_printf_expand("%s\n", val);
5621 } else if (exp_op) {
5622 if (exp_op == '%' || exp_op == '#') {
5623 /* Standard-mandated substring removal ops:
5624 * ${parameter%word} - remove smallest suffix pattern
5625 * ${parameter%%word} - remove largest suffix pattern
5626 * ${parameter#word} - remove smallest prefix pattern
5627 * ${parameter##word} - remove largest prefix pattern
5629 * Word is expanded to produce a glob pattern.
5630 * Then var's value is matched to it and matching part removed.
5632 if (val && val[0]) {
5636 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5637 if (exp_op == *exp_word) /* ## or %% */
5639 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5641 exp_word = exp_exp_word;
5642 /* HACK ALERT. We depend here on the fact that
5643 * G.global_argv and results of utoa and get_local_var_value
5644 * are actually in writable memory:
5645 * scan_and_match momentarily stores NULs there. */
5647 loc = scan_and_match(t, exp_word, scan_flags);
5648 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5649 // exp_op, t, exp_word, loc);
5651 if (loc) { /* match was found */
5652 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5653 val = loc; /* take right part */
5655 val = to_be_freed = xstrndup(val, loc - val); /* left */
5659 #if BASH_PATTERN_SUBST
5660 else if (exp_op == '/' || exp_op == '\\') {
5661 /* It's ${var/[/]pattern[/repl]} thing.
5662 * Note that in encoded form it has TWO parts:
5663 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5664 * and if // is used, it is encoded as \:
5665 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5667 /* Empty variable always gives nothing: */
5668 // "v=''; echo ${v/*/w}" prints "", not "w"
5669 if (val && val[0]) {
5670 /* pattern uses non-standard expansion.
5671 * repl should be unbackslashed and globbed
5672 * by the usual expansion rules:
5674 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5675 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5676 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5677 * v='a bz'; echo ${v/a*z/\z} prints "z"
5678 * (note that a*z _pattern_ is never globbed!)
5680 char *pattern, *repl, *t;
5681 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5683 pattern = xstrdup(exp_word);
5684 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5685 *p++ = SPECIAL_VAR_SYMBOL;
5687 p = strchr(p, SPECIAL_VAR_SYMBOL);
5689 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5690 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5691 /* HACK ALERT. We depend here on the fact that
5692 * G.global_argv and results of utoa and get_local_var_value
5693 * are actually in writable memory:
5694 * replace_pattern momentarily stores NULs there. */
5696 to_be_freed = replace_pattern(t,
5698 (repl ? repl : exp_word),
5700 if (to_be_freed) /* at least one replace happened */
5706 #endif /* BASH_PATTERN_SUBST */
5707 else if (exp_op == ':') {
5708 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5709 /* It's ${var:N[:M]} bashism.
5710 * Note that in encoded form it has TWO parts:
5711 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5716 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5719 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5720 *p++ = SPECIAL_VAR_SYMBOL;
5722 p = strchr(p, SPECIAL_VAR_SYMBOL);
5724 len = expand_and_evaluate_arith(exp_word, &errmsg);
5727 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5729 /* negative beg counts from the end */
5730 beg = (arith_t)strlen(val) + beg;
5731 if (beg < 0) /* ${v: -999999} is "" */
5734 debug_printf_varexp("from val:'%s'\n", val);
5736 /* in bash, len=-n means strlen()-n */
5737 len = (arith_t)strlen(val) - beg + len;
5738 if (len < 0) /* bash compat */
5739 die_if_script("%s: substring expression < 0", var);
5741 if (len <= 0 || !val || beg >= strlen(val)) {
5745 /* Paranoia. What if user entered 9999999999999
5746 * which fits in arith_t but not int? */
5749 val = to_be_freed = xstrndup(val + beg, len);
5751 debug_printf_varexp("val:'%s'\n", val);
5752 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5753 die_if_script("malformed ${%s:...}", var);
5756 } else { /* one of "-=+?" */
5757 /* Standard-mandated substitution ops:
5758 * ${var?word} - indicate error if unset
5759 * If var is unset, word (or a message indicating it is unset
5760 * if word is null) is written to standard error
5761 * and the shell exits with a non-zero exit status.
5762 * Otherwise, the value of var is substituted.
5763 * ${var-word} - use default value
5764 * If var is unset, word is substituted.
5765 * ${var=word} - assign and use default value
5766 * If var is unset, word is assigned to var.
5767 * In all cases, final value of var is substituted.
5768 * ${var+word} - use alternative value
5769 * If var is unset, null is substituted.
5770 * Otherwise, word is substituted.
5772 * Word is subjected to tilde expansion, parameter expansion,
5773 * command substitution, and arithmetic expansion.
5774 * If word is not needed, it is not expanded.
5776 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5777 * but also treat null var as if it is unset.
5779 int use_word = (!val || ((exp_save == ':') && !val[0]));
5781 use_word = !use_word;
5782 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5783 (exp_save == ':') ? "true" : "false", use_word);
5785 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5787 exp_word = to_be_freed;
5788 if (exp_op == '?') {
5789 /* mimic bash message */
5790 die_if_script("%s: %s",
5792 exp_word[0] ? exp_word : "parameter null or not set"
5794 //TODO: how interactive bash aborts expansion mid-command?
5799 if (exp_op == '=') {
5800 /* ${var=[word]} or ${var:=[word]} */
5801 if (isdigit(var[0]) || var[0] == '#') {
5802 /* mimic bash message */
5803 die_if_script("$%s: cannot assign in this way", var);
5806 char *new_var = xasprintf("%s=%s", var, val);
5807 set_local_var(new_var, /*flag:*/ 0);
5811 } /* one of "-=+?" */
5813 *exp_saveptr = exp_save;
5819 *to_be_freed_pp = to_be_freed;
5823 /* Expand all variable references in given string, adding words to list[]
5824 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5825 * to be filled). This routine is extremely tricky: has to deal with
5826 * variables/parameters with whitespace, $* and $@, and constructs like
5827 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5828 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5830 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5831 * expansion of right-hand side of assignment == 1-element expand.
5833 char cant_be_null = 0; /* only bit 0x80 matters */
5834 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5837 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5838 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5839 debug_print_list("expand_vars_to_list", output, n);
5840 n = o_save_ptr(output, n);
5841 debug_print_list("expand_vars_to_list[0]", output, n);
5843 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5845 char *to_be_freed = NULL;
5846 const char *val = NULL;
5847 #if ENABLE_HUSH_TICK
5848 o_string subst_result = NULL_O_STRING;
5850 #if ENABLE_FEATURE_SH_MATH
5851 char arith_buf[sizeof(arith_t)*3 + 2];
5855 o_addchr(output, '\0');
5856 n = o_save_ptr(output, n);
5860 o_addblock(output, arg, p - arg);
5861 debug_print_list("expand_vars_to_list[1]", output, n);
5863 p = strchr(p, SPECIAL_VAR_SYMBOL);
5865 /* Fetch special var name (if it is indeed one of them)
5866 * and quote bit, force the bit on if singleword expansion -
5867 * important for not getting v=$@ expand to many words. */
5868 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5870 /* Is this variable quoted and thus expansion can't be null?
5871 * "$@" is special. Even if quoted, it can still
5872 * expand to nothing (not even an empty string),
5873 * thus it is excluded. */
5874 if ((first_ch & 0x7f) != '@')
5875 cant_be_null |= first_ch;
5877 switch (first_ch & 0x7f) {
5878 /* Highest bit in first_ch indicates that var is double-quoted */
5882 if (!G.global_argv[1])
5885 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5886 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5887 while (G.global_argv[i]) {
5888 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5889 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5890 if (G.global_argv[i++][0] && G.global_argv[i]) {
5891 /* this argv[] is not empty and not last:
5892 * put terminating NUL, start new word */
5893 o_addchr(output, '\0');
5894 debug_print_list("expand_vars_to_list[2]", output, n);
5895 n = o_save_ptr(output, n);
5896 debug_print_list("expand_vars_to_list[3]", output, n);
5900 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5901 * and in this case should treat it like '$*' - see 'else...' below */
5902 if (first_ch == ('@'|0x80) /* quoted $@ */
5903 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5906 o_addQstr(output, G.global_argv[i]);
5907 if (++i >= G.global_argc)
5909 o_addchr(output, '\0');
5910 debug_print_list("expand_vars_to_list[4]", output, n);
5911 n = o_save_ptr(output, n);
5913 } else { /* quoted $* (or v="$@" case): add as one word */
5915 o_addQstr(output, G.global_argv[i]);
5916 if (!G.global_argv[++i])
5919 o_addchr(output, G.ifs[0]);
5921 output->has_quoted_part = 1;
5925 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5926 /* "Empty variable", used to make "" etc to not disappear */
5927 output->has_quoted_part = 1;
5929 cant_be_null = 0x80;
5931 #if ENABLE_HUSH_TICK
5932 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5933 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5935 /* Can't just stuff it into output o_string,
5936 * expanded result may need to be globbed
5938 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5939 G.last_exitcode = process_command_subs(&subst_result, arg);
5940 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5941 val = subst_result.data;
5944 #if ENABLE_FEATURE_SH_MATH
5945 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5948 arg++; /* skip '+' */
5949 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5950 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5951 res = expand_and_evaluate_arith(arg, NULL);
5952 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5953 sprintf(arith_buf, ARITH_FMT, res);
5959 val = expand_one_var(&to_be_freed, arg, &p);
5960 IF_HUSH_TICK(store_val:)
5961 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5962 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5963 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5964 if (val && val[0]) {
5965 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5968 } else { /* quoted $VAR, val will be appended below */
5969 output->has_quoted_part = 1;
5970 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5971 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5974 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5976 if (val && val[0]) {
5977 o_addQstr(output, val);
5981 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5982 * Do the check to avoid writing to a const string. */
5983 if (*p != SPECIAL_VAR_SYMBOL)
5984 *p = SPECIAL_VAR_SYMBOL;
5986 #if ENABLE_HUSH_TICK
5987 o_free(&subst_result);
5990 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5994 o_addchr(output, '\0');
5995 n = o_save_ptr(output, n);
5997 debug_print_list("expand_vars_to_list[a]", output, n);
5998 /* this part is literal, and it was already pre-quoted
5999 * if needed (much earlier), do not use o_addQstr here! */
6000 o_addstr_with_NUL(output, arg);
6001 debug_print_list("expand_vars_to_list[b]", output, n);
6002 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6003 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6006 /* allow to reuse list[n] later without re-growth */
6007 output->has_empty_slot = 1;
6009 o_addchr(output, '\0');
6015 static char **expand_variables(char **argv, unsigned expflags)
6019 o_string output = NULL_O_STRING;
6021 output.o_expflags = expflags;
6025 n = expand_vars_to_list(&output, n, *argv);
6028 debug_print_list("expand_variables", &output, n);
6030 /* output.data (malloced in one block) gets returned in "list" */
6031 list = o_finalize_list(&output, n);
6032 debug_print_strings("expand_variables[1]", list);
6036 static char **expand_strvec_to_strvec(char **argv)
6038 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6042 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6044 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6048 /* Used for expansion of right hand of assignments,
6049 * $((...)), heredocs, variable espansion parts.
6051 * NB: should NOT do globbing!
6052 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6054 static char *expand_string_to_string(const char *str, int do_unbackslash)
6056 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6057 const int do_unbackslash = 1;
6059 char *argv[2], **list;
6061 debug_printf_expand("string_to_string<='%s'\n", str);
6062 /* This is generally an optimization, but it also
6063 * handles "", which otherwise trips over !list[0] check below.
6064 * (is this ever happens that we actually get str="" here?)
6066 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6067 //TODO: Can use on strings with \ too, just unbackslash() them?
6068 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6069 return xstrdup(str);
6072 argv[0] = (char*)str;
6074 list = expand_variables(argv, do_unbackslash
6075 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6076 : EXP_FLAG_SINGLEWORD
6079 if (!list[0] || list[1])
6080 bb_error_msg_and_die("BUG in varexp2");
6081 /* actually, just move string 2*sizeof(char*) bytes back */
6082 overlapping_strcpy((char*)list, list[0]);
6084 unbackslash((char*)list);
6085 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6089 /* Used for "eval" builtin and case string */
6090 static char* expand_strvec_to_string(char **argv)
6094 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6095 /* Convert all NULs to spaces */
6100 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6101 bb_error_msg_and_die("BUG in varexp3");
6102 /* bash uses ' ' regardless of $IFS contents */
6107 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6108 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6112 static char **expand_assignments(char **argv, int count)
6117 G.expanded_assignments = p = NULL;
6118 /* Expand assignments into one string each */
6119 for (i = 0; i < count; i++) {
6120 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6122 G.expanded_assignments = NULL;
6127 static void switch_off_special_sigs(unsigned mask)
6130 while ((mask >>= 1) != 0) {
6134 #if ENABLE_HUSH_TRAP
6136 if (G_traps[sig] && !G_traps[sig][0])
6137 /* trap is '', has to remain SIG_IGN */
6140 G_traps[sig] = NULL;
6143 /* We are here only if no trap or trap was not '' */
6144 install_sighandler(sig, SIG_DFL);
6150 void re_execute_shell(char ***to_free, const char *s,
6151 char *g_argv0, char **g_argv,
6152 char **builtin_argv) NORETURN;
6154 static void reset_traps_to_defaults(void)
6156 /* This function is always called in a child shell
6157 * after fork (not vfork, NOMMU doesn't use this function).
6159 IF_HUSH_TRAP(unsigned sig;)
6162 /* Child shells are not interactive.
6163 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6164 * Testcase: (while :; do :; done) + ^Z should background.
6165 * Same goes for SIGTERM, SIGHUP, SIGINT.
6167 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6168 if (!G_traps && !mask)
6169 return; /* already no traps and no special sigs */
6171 /* Switch off special sigs */
6172 switch_off_special_sigs(mask);
6173 # if ENABLE_HUSH_JOB
6174 G_fatal_sig_mask = 0;
6176 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6177 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6178 * remain set in G.special_sig_mask */
6180 # if ENABLE_HUSH_TRAP
6184 /* Reset all sigs to default except ones with empty traps */
6185 for (sig = 0; sig < NSIG; sig++) {
6187 continue; /* no trap: nothing to do */
6188 if (!G_traps[sig][0])
6189 continue; /* empty trap: has to remain SIG_IGN */
6190 /* sig has non-empty trap, reset it: */
6192 G_traps[sig] = NULL;
6193 /* There is no signal for trap 0 (EXIT) */
6196 install_sighandler(sig, pick_sighandler(sig));
6203 static void re_execute_shell(char ***to_free, const char *s,
6204 char *g_argv0, char **g_argv,
6205 char **builtin_argv) NORETURN;
6206 static void re_execute_shell(char ***to_free, const char *s,
6207 char *g_argv0, char **g_argv,
6208 char **builtin_argv)
6210 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6211 /* delims + 2 * (number of bytes in printed hex numbers) */
6212 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6213 char *heredoc_argv[4];
6214 struct variable *cur;
6215 # if ENABLE_HUSH_FUNCTIONS
6216 struct function *funcp;
6220 unsigned long long empty_trap_mask;
6222 if (!g_argv0) { /* heredoc */
6223 argv = heredoc_argv;
6224 argv[0] = (char *) G.argv0_for_re_execing;
6225 argv[1] = (char *) "-<";
6226 argv[2] = (char *) s;
6228 pp = &argv[3]; /* used as pointer to empty environment */
6234 if (pp) while (*pp++)
6237 empty_trap_mask = 0;
6240 for (sig = 1; sig < NSIG; sig++) {
6241 if (G_traps[sig] && !G_traps[sig][0])
6242 empty_trap_mask |= 1LL << sig;
6246 sprintf(param_buf, NOMMU_HACK_FMT
6247 , (unsigned) G.root_pid
6248 , (unsigned) G.root_ppid
6249 , (unsigned) G.last_bg_pid
6250 , (unsigned) G.last_exitcode
6253 IF_HUSH_LOOPS(, G.depth_of_loop)
6255 # undef NOMMU_HACK_FMT
6256 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6257 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6260 for (cur = G.top_var; cur; cur = cur->next) {
6261 if (!cur->flg_export || cur->flg_read_only)
6264 # if ENABLE_HUSH_FUNCTIONS
6265 for (funcp = G.top_func; funcp; funcp = funcp->next)
6271 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6272 *pp++ = (char *) G.argv0_for_re_execing;
6274 for (cur = G.top_var; cur; cur = cur->next) {
6275 if (strcmp(cur->varstr, hush_version_str) == 0)
6277 if (cur->flg_read_only) {
6278 *pp++ = (char *) "-R";
6279 *pp++ = cur->varstr;
6280 } else if (!cur->flg_export) {
6281 *pp++ = (char *) "-V";
6282 *pp++ = cur->varstr;
6285 # if ENABLE_HUSH_FUNCTIONS
6286 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6287 *pp++ = (char *) "-F";
6288 *pp++ = funcp->name;
6289 *pp++ = funcp->body_as_string;
6292 /* We can pass activated traps here. Say, -Tnn:trap_string
6294 * However, POSIX says that subshells reset signals with traps
6296 * I tested bash-3.2 and it not only does that with true subshells
6297 * of the form ( list ), but with any forked children shells.
6298 * I set trap "echo W" WINCH; and then tried:
6300 * { echo 1; sleep 20; echo 2; } &
6301 * while true; do echo 1; sleep 20; echo 2; break; done &
6302 * true | { echo 1; sleep 20; echo 2; } | cat
6304 * In all these cases sending SIGWINCH to the child shell
6305 * did not run the trap. If I add trap "echo V" WINCH;
6306 * _inside_ group (just before echo 1), it works.
6308 * I conclude it means we don't need to pass active traps here.
6310 *pp++ = (char *) "-c";
6313 while (*++builtin_argv)
6314 *pp++ = *builtin_argv;
6315 *pp++ = (char *) "";
6320 /* *pp = NULL; - is already there */
6324 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6325 /* Don't propagate SIG_IGN to the child */
6326 if (SPECIAL_JOBSTOP_SIGS != 0)
6327 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6328 execve(bb_busybox_exec_path, argv, pp);
6329 /* Fallback. Useful for init=/bin/hush usage etc */
6330 if (argv[0][0] == '/')
6331 execve(argv[0], argv, pp);
6332 xfunc_error_retval = 127;
6333 bb_error_msg_and_die("can't re-execute the shell");
6335 #endif /* !BB_MMU */
6338 static int run_and_free_list(struct pipe *pi);
6340 /* Executing from string: eval, sh -c '...'
6341 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6342 * end_trigger controls how often we stop parsing
6343 * NUL: parse all, execute, return
6344 * ';': parse till ';' or newline, execute, repeat till EOF
6346 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6348 /* Why we need empty flag?
6349 * An obscure corner case "false; ``; echo $?":
6350 * empty command in `` should still set $? to 0.
6351 * But we can't just set $? to 0 at the start,
6352 * this breaks "false; echo `echo $?`" case.
6356 struct pipe *pipe_list;
6358 #if ENABLE_HUSH_INTERACTIVE
6359 if (end_trigger == ';')
6360 inp->promptmode = 0; /* PS1 */
6362 pipe_list = parse_stream(NULL, inp, end_trigger);
6363 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6364 /* If we are in "big" script
6365 * (not in `cmd` or something similar)...
6367 if (pipe_list == ERR_PTR && end_trigger == ';') {
6368 /* Discard cached input (rest of line) */
6369 int ch = inp->last_char;
6370 while (ch != EOF && ch != '\n') {
6371 //bb_error_msg("Discarded:'%c'", ch);
6376 /* This stream isn't empty */
6380 if (!pipe_list && empty)
6381 G.last_exitcode = 0;
6384 debug_print_tree(pipe_list, 0);
6385 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6386 run_and_free_list(pipe_list);
6388 if (G_flag_return_in_progress == 1)
6393 static void parse_and_run_string(const char *s)
6395 struct in_str input;
6396 setup_string_in_str(&input, s);
6397 parse_and_run_stream(&input, '\0');
6400 static void parse_and_run_file(FILE *f)
6402 struct in_str input;
6403 setup_file_in_str(&input, f);
6404 parse_and_run_stream(&input, ';');
6407 #if ENABLE_HUSH_TICK
6408 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6413 char **to_free = NULL;
6417 pid = BB_MMU ? xfork() : xvfork();
6418 if (pid == 0) { /* child */
6419 disable_restore_tty_pgrp_on_exit();
6420 /* Process substitution is not considered to be usual
6421 * 'command execution'.
6422 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6429 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6430 close(channel[0]); /* NB: close _first_, then move fd! */
6431 xmove_fd(channel[1], 1);
6432 /* Prevent it from trying to handle ctrl-z etc */
6433 IF_HUSH_JOB(G.run_list_level = 1;)
6434 # if ENABLE_HUSH_TRAP
6435 /* Awful hack for `trap` or $(trap).
6437 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6438 * contains an example where "trap" is executed in a subshell:
6440 * save_traps=$(trap)
6442 * eval "$save_traps"
6444 * Standard does not say that "trap" in subshell shall print
6445 * parent shell's traps. It only says that its output
6446 * must have suitable form, but then, in the above example
6447 * (which is not supposed to be normative), it implies that.
6449 * bash (and probably other shell) does implement it
6450 * (traps are reset to defaults, but "trap" still shows them),
6451 * but as a result, "trap" logic is hopelessly messed up:
6454 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6455 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6456 * # true | trap <--- trap is in subshell - no output (ditto)
6457 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6458 * trap -- 'echo Ho' SIGWINCH
6459 * # echo `(trap)` <--- in subshell in subshell - output
6460 * trap -- 'echo Ho' SIGWINCH
6461 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6462 * trap -- 'echo Ho' SIGWINCH
6464 * The rules when to forget and when to not forget traps
6465 * get really complex and nonsensical.
6467 * Our solution: ONLY bare $(trap) or `trap` is special.
6469 s = skip_whitespace(s);
6470 if (is_prefixed_with(s, "trap")
6471 && skip_whitespace(s + 4)[0] == '\0'
6473 static const char *const argv[] = { NULL, NULL };
6474 builtin_trap((char**)argv);
6475 fflush_all(); /* important */
6480 reset_traps_to_defaults();
6481 parse_and_run_string(s);
6482 _exit(G.last_exitcode);
6484 /* We re-execute after vfork on NOMMU. This makes this script safe:
6485 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6486 * huge=`cat BIG` # was blocking here forever
6489 re_execute_shell(&to_free,
6499 # if ENABLE_HUSH_FAST
6501 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6502 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6503 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6505 enable_restore_tty_pgrp_on_exit();
6510 return remember_FILE(xfdopen_for_read(channel[0]));
6513 /* Return code is exit status of the process that is run. */
6514 static int process_command_subs(o_string *dest, const char *s)
6517 struct in_str pipe_str;
6519 int status, ch, eol_cnt;
6521 fp = generate_stream_from_string(s, &pid);
6523 /* Now send results of command back into original context */
6524 setup_file_in_str(&pipe_str, fp);
6526 while ((ch = i_getch(&pipe_str)) != EOF) {
6532 o_addchr(dest, '\n');
6535 o_addQchr(dest, ch);
6538 debug_printf("done reading from `cmd` pipe, closing it\n");
6539 fclose_and_forget(fp);
6540 /* We need to extract exitcode. Test case
6541 * "true; echo `sleep 1; false` $?"
6543 safe_waitpid(pid, &status, 0);
6544 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6545 return WEXITSTATUS(status);
6547 #endif /* ENABLE_HUSH_TICK */
6550 static void setup_heredoc(struct redir_struct *redir)
6552 struct fd_pair pair;
6555 /* the _body_ of heredoc (misleading field name) */
6556 const char *heredoc = redir->rd_filename;
6563 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6564 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6568 len = strlen(heredoc);
6570 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6572 xmove_fd(pair.rd, redir->rd_fd);
6574 /* Try writing without forking. Newer kernels have
6575 * dynamically growing pipes. Must use non-blocking write! */
6578 written = write(pair.wr, heredoc, len);
6589 ndelay_off(pair.wr);
6591 /* Okay, pipe buffer was not big enough */
6592 /* Note: we must not create a stray child (bastard? :)
6593 * for the unsuspecting parent process. Child creates a grandchild
6594 * and exits before parent execs the process which consumes heredoc
6595 * (that exec happens after we return from this function) */
6602 disable_restore_tty_pgrp_on_exit();
6603 pid = BB_MMU ? xfork() : xvfork();
6607 close(redir->rd_fd); /* read side of the pipe */
6609 full_write(pair.wr, heredoc, len); /* may loop or block */
6612 /* Delegate blocking writes to another process */
6613 xmove_fd(pair.wr, STDOUT_FILENO);
6614 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6618 #if ENABLE_HUSH_FAST
6620 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6622 enable_restore_tty_pgrp_on_exit();
6628 wait(NULL); /* wait till child has died */
6634 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6635 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6638 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6642 if (sq) while (sq[i].orig_fd >= 0) {
6643 /* If we collide with an already moved fd... */
6644 if (fd == sq[i].moved_to) {
6645 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6646 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6647 if (sq[i].moved_to < 0) /* what? */
6651 if (fd == sq[i].orig_fd) {
6652 /* Example: echo Hello >/dev/null 1>&2 */
6653 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6659 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6661 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6662 sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6663 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to);
6664 if (sq[i].moved_to < 0 && errno != EBADF)
6666 sq[i+1].orig_fd = -1; /* end marker */
6670 /* fd: redirect wants this fd to be used (e.g. 3>file).
6671 * Move all conflicting internally used fds,
6672 * and remember them so that we can restore them later.
6674 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6676 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6679 #if ENABLE_HUSH_INTERACTIVE
6680 if (fd != 0 && fd == G.interactive_fd) {
6681 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6682 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6683 return 1; /* "we closed fd" */
6686 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6687 * (1) Redirect in a forked child. No need to save FILEs' fds,
6688 * we aren't going to use them anymore, ok to trash.
6689 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6690 * but how are we doing to restore them?
6691 * "fileno(fd) = new_fd" can't be done.
6696 /* If this one of script's fds? */
6697 if (save_FILEs_on_redirect(fd, avoid_fd))
6698 return 1; /* yes. "we closed fd" */
6700 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6701 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6702 return 0; /* "we did not close fd" */
6705 static void restore_redirects(struct squirrel *sq)
6710 while (sq[i].orig_fd >= 0) {
6711 if (sq[i].moved_to >= 0) {
6712 /* We simply die on error */
6713 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6714 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6716 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6717 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6718 close(sq[i].orig_fd);
6725 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6727 restore_redirected_FILEs();
6730 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6731 * and stderr if they are redirected. */
6732 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6735 struct redir_struct *redir;
6737 for (redir = prog->redirects; redir; redir = redir->next) {
6738 if (redir->rd_type == REDIRECT_HEREDOC2) {
6739 /* "rd_fd<<HERE" case */
6740 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6741 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6743 debug_printf_parse("set heredoc '%s'\n",
6744 redir->rd_filename);
6745 setup_heredoc(redir);
6749 if (redir->rd_dup == REDIRFD_TO_FILE) {
6750 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6752 if (redir->rd_filename == NULL) {
6755 * "cmd >" (no filename)
6756 * "cmd > <file" (2nd redirect starts too early)
6758 die_if_script("syntax error: %s", "invalid redirect");
6761 mode = redir_table[redir->rd_type].mode;
6762 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6763 openfd = open_or_warn(p, mode);
6766 /* Error message from open_or_warn can be lost
6767 * if stderr has been redirected, but bash
6768 * and ash both lose it as well
6769 * (though zsh doesn't!)
6774 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6775 openfd = redir->rd_dup;
6778 if (openfd != redir->rd_fd) {
6779 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6780 if (openfd == REDIRFD_CLOSE) {
6781 /* "rd_fd >&-" means "close me" */
6783 /* ^^^ optimization: saving may already
6784 * have closed it. If not... */
6785 close(redir->rd_fd);
6788 xdup2(openfd, redir->rd_fd);
6789 if (redir->rd_dup == REDIRFD_TO_FILE)
6790 /* "rd_fd > FILE" */
6792 /* else: "rd_fd > rd_dup" */
6799 static char *find_in_path(const char *arg)
6802 const char *PATH = get_local_var_value("PATH");
6808 const char *end = strchrnul(PATH, ':');
6809 int sz = end - PATH; /* must be int! */
6813 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6815 /* We have xxx::yyyy in $PATH,
6816 * it means "use current dir" */
6819 if (access(ret, F_OK) == 0)
6832 static const struct built_in_command *find_builtin_helper(const char *name,
6833 const struct built_in_command *x,
6834 const struct built_in_command *end)
6837 if (strcmp(name, x->b_cmd) != 0) {
6841 debug_printf_exec("found builtin '%s'\n", name);
6846 static const struct built_in_command *find_builtin1(const char *name)
6848 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6850 static const struct built_in_command *find_builtin(const char *name)
6852 const struct built_in_command *x = find_builtin1(name);
6855 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6858 #if ENABLE_HUSH_FUNCTIONS
6859 static struct function **find_function_slot(const char *name)
6861 struct function **funcpp = &G.top_func;
6863 if (strcmp(name, (*funcpp)->name) == 0) {
6866 funcpp = &(*funcpp)->next;
6871 static const struct function *find_function(const char *name)
6873 const struct function *funcp = *find_function_slot(name);
6875 debug_printf_exec("found function '%s'\n", name);
6879 /* Note: takes ownership on name ptr */
6880 static struct function *new_function(char *name)
6882 struct function **funcpp = find_function_slot(name);
6883 struct function *funcp = *funcpp;
6885 if (funcp != NULL) {
6886 struct command *cmd = funcp->parent_cmd;
6887 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6889 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6891 /* Note: if !funcp->body, do not free body_as_string!
6892 * This is a special case of "-F name body" function:
6893 * body_as_string was not malloced! */
6895 free_pipe_list(funcp->body);
6897 free(funcp->body_as_string);
6901 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6902 cmd->argv[0] = funcp->name;
6903 cmd->group = funcp->body;
6905 cmd->group_as_string = funcp->body_as_string;
6909 debug_printf_exec("remembering new function '%s'\n", name);
6910 funcp = *funcpp = xzalloc(sizeof(*funcp));
6911 /*funcp->next = NULL;*/
6918 # if ENABLE_HUSH_UNSET
6919 static void unset_func(const char *name)
6921 struct function **funcpp = find_function_slot(name);
6922 struct function *funcp = *funcpp;
6924 if (funcp != NULL) {
6925 debug_printf_exec("freeing function '%s'\n", funcp->name);
6926 *funcpp = funcp->next;
6927 /* funcp is unlinked now, deleting it.
6928 * Note: if !funcp->body, the function was created by
6929 * "-F name body", do not free ->body_as_string
6930 * and ->name as they were not malloced. */
6932 free_pipe_list(funcp->body);
6935 free(funcp->body_as_string);
6944 #define exec_function(to_free, funcp, argv) \
6945 exec_function(funcp, argv)
6947 static void exec_function(char ***to_free,
6948 const struct function *funcp,
6949 char **argv) NORETURN;
6950 static void exec_function(char ***to_free,
6951 const struct function *funcp,
6957 argv[0] = G.global_argv[0];
6958 G.global_argv = argv;
6959 G.global_argc = n = 1 + string_array_len(argv + 1);
6960 /* On MMU, funcp->body is always non-NULL */
6961 n = run_list(funcp->body);
6965 re_execute_shell(to_free,
6966 funcp->body_as_string,
6973 static int run_function(const struct function *funcp, char **argv)
6979 save_and_replace_G_args(&sv, argv);
6981 /* "we are in function, ok to use return" */
6982 sv_flg = G_flag_return_in_progress;
6983 G_flag_return_in_progress = -1;
6984 # if ENABLE_HUSH_LOCAL
6985 G.func_nest_level++;
6988 /* On MMU, funcp->body is always non-NULL */
6991 /* Function defined by -F */
6992 parse_and_run_string(funcp->body_as_string);
6993 rc = G.last_exitcode;
6997 rc = run_list(funcp->body);
7000 # if ENABLE_HUSH_LOCAL
7002 struct variable *var;
7003 struct variable **var_pp;
7005 var_pp = &G.top_var;
7006 while ((var = *var_pp) != NULL) {
7007 if (var->func_nest_level < G.func_nest_level) {
7008 var_pp = &var->next;
7012 if (var->flg_export)
7013 bb_unsetenv(var->varstr);
7014 /* Remove from global list */
7015 *var_pp = var->next;
7021 G.func_nest_level--;
7024 G_flag_return_in_progress = sv_flg;
7026 restore_G_args(&sv, argv);
7030 #endif /* ENABLE_HUSH_FUNCTIONS */
7034 #define exec_builtin(to_free, x, argv) \
7035 exec_builtin(x, argv)
7037 #define exec_builtin(to_free, x, argv) \
7038 exec_builtin(to_free, argv)
7040 static void exec_builtin(char ***to_free,
7041 const struct built_in_command *x,
7042 char **argv) NORETURN;
7043 static void exec_builtin(char ***to_free,
7044 const struct built_in_command *x,
7050 rcode = x->b_function(argv);
7055 /* On NOMMU, we must never block!
7056 * Example: { sleep 99 | read line; } & echo Ok
7058 re_execute_shell(to_free,
7067 static void execvp_or_die(char **argv) NORETURN;
7068 static void execvp_or_die(char **argv)
7071 debug_printf_exec("execing '%s'\n", argv[0]);
7072 /* Don't propagate SIG_IGN to the child */
7073 if (SPECIAL_JOBSTOP_SIGS != 0)
7074 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7075 execvp(argv[0], argv);
7077 if (errno == EACCES) e = 126;
7078 if (errno == ENOENT) e = 127;
7079 bb_perror_msg("can't execute '%s'", argv[0]);
7083 #if ENABLE_HUSH_MODE_X
7084 static void dump_cmd_in_x_mode(char **argv)
7086 if (G_x_mode && argv) {
7087 /* We want to output the line in one write op */
7095 len += strlen(argv[n++]) + 1;
7101 p += sprintf(p, " %s", argv[n++]);
7109 # define dump_cmd_in_x_mode(argv) ((void)0)
7113 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7114 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7115 #define pseudo_exec(nommu_save, command, argv_expanded) \
7116 pseudo_exec(command, argv_expanded)
7119 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7121 * Don't exit() here. If you don't exec, use _exit instead.
7122 * The at_exit handlers apparently confuse the calling process,
7123 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7125 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7126 char **argv, int assignment_cnt,
7127 char **argv_expanded) NORETURN;
7128 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7129 char **argv, int assignment_cnt,
7130 char **argv_expanded)
7134 new_env = expand_assignments(argv, assignment_cnt);
7135 dump_cmd_in_x_mode(new_env);
7137 if (!argv[assignment_cnt]) {
7138 /* Case when we are here: ... | var=val | ...
7139 * (note that we do not exit early, i.e., do not optimize out
7140 * expand_assignments(): think about ... | var=`sleep 1` | ...
7142 free_strings(new_env);
7143 _exit(EXIT_SUCCESS);
7147 set_vars_and_save_old(new_env);
7148 free(new_env); /* optional */
7149 /* we can also destroy set_vars_and_save_old's return value,
7152 nommu_save->new_env = new_env;
7153 nommu_save->old_vars = set_vars_and_save_old(new_env);
7156 if (argv_expanded) {
7157 argv = argv_expanded;
7159 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7161 nommu_save->argv = argv;
7164 dump_cmd_in_x_mode(argv);
7166 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7167 if (strchr(argv[0], '/') != NULL)
7171 /* Check if the command matches any of the builtins.
7172 * Depending on context, this might be redundant. But it's
7173 * easier to waste a few CPU cycles than it is to figure out
7174 * if this is one of those cases.
7177 /* On NOMMU, it is more expensive to re-execute shell
7178 * just in order to run echo or test builtin.
7179 * It's better to skip it here and run corresponding
7180 * non-builtin later. */
7181 const struct built_in_command *x;
7182 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7184 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7187 #if ENABLE_HUSH_FUNCTIONS
7188 /* Check if the command matches any functions */
7190 const struct function *funcp = find_function(argv[0]);
7192 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7197 #if ENABLE_FEATURE_SH_STANDALONE
7198 /* Check if the command matches any busybox applets */
7200 int a = find_applet_by_name(argv[0]);
7202 # if BB_MMU /* see above why on NOMMU it is not allowed */
7203 if (APPLET_IS_NOEXEC(a)) {
7204 /* Do not leak open fds from opened script files etc */
7205 close_all_FILE_list();
7206 debug_printf_exec("running applet '%s'\n", argv[0]);
7207 run_applet_no_and_exit(a, argv[0], argv);
7210 /* Re-exec ourselves */
7211 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7212 /* Don't propagate SIG_IGN to the child */
7213 if (SPECIAL_JOBSTOP_SIGS != 0)
7214 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7215 execv(bb_busybox_exec_path, argv);
7216 /* If they called chroot or otherwise made the binary no longer
7217 * executable, fall through */
7222 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7225 execvp_or_die(argv);
7228 /* Called after [v]fork() in run_pipe
7230 static void pseudo_exec(nommu_save_t *nommu_save,
7231 struct command *command,
7232 char **argv_expanded) NORETURN;
7233 static void pseudo_exec(nommu_save_t *nommu_save,
7234 struct command *command,
7235 char **argv_expanded)
7237 if (command->argv) {
7238 pseudo_exec_argv(nommu_save, command->argv,
7239 command->assignment_cnt, argv_expanded);
7242 if (command->group) {
7243 /* Cases when we are here:
7246 * ... | ( list ) | ...
7247 * ... | { list } | ...
7251 debug_printf_exec("pseudo_exec: run_list\n");
7252 reset_traps_to_defaults();
7253 rcode = run_list(command->group);
7254 /* OK to leak memory by not calling free_pipe_list,
7255 * since this process is about to exit */
7258 re_execute_shell(&nommu_save->argv_from_re_execing,
7259 command->group_as_string,
7266 /* Case when we are here: ... | >file */
7267 debug_printf_exec("pseudo_exec'ed null command\n");
7268 _exit(EXIT_SUCCESS);
7272 static const char *get_cmdtext(struct pipe *pi)
7278 /* This is subtle. ->cmdtext is created only on first backgrounding.
7279 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7280 * On subsequent bg argv is trashed, but we won't use it */
7284 argv = pi->cmds[0].argv;
7286 pi->cmdtext = xzalloc(1);
7291 len += strlen(*argv) + 1;
7295 argv = pi->cmds[0].argv;
7297 p = stpcpy(p, *argv);
7304 static void remove_job_from_table(struct pipe *pi)
7306 struct pipe *prev_pipe;
7308 if (pi == G.job_list) {
7309 G.job_list = pi->next;
7311 prev_pipe = G.job_list;
7312 while (prev_pipe->next != pi)
7313 prev_pipe = prev_pipe->next;
7314 prev_pipe->next = pi->next;
7318 G.last_jobid = G.job_list->jobid;
7321 static void delete_finished_job(struct pipe *pi)
7323 remove_job_from_table(pi);
7327 static void clean_up_last_dead_job(void)
7329 if (G.job_list && !G.job_list->alive_cmds)
7330 delete_finished_job(G.job_list);
7333 static void insert_job_into_table(struct pipe *pi)
7335 struct pipe *job, **jobp;
7338 clean_up_last_dead_job();
7340 /* Find the end of the list, and find next job ID to use */
7343 while ((job = *jobp) != NULL) {
7350 /* Create a new job struct at the end */
7351 job = *jobp = xmemdup(pi, sizeof(*pi));
7353 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7354 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7355 for (i = 0; i < pi->num_cmds; i++) {
7356 job->cmds[i].pid = pi->cmds[i].pid;
7357 /* all other fields are not used and stay zero */
7359 job->cmdtext = xstrdup(get_cmdtext(pi));
7361 if (G_interactive_fd)
7362 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7363 G.last_jobid = job->jobid;
7367 static int job_exited_or_stopped(struct pipe *pi)
7371 if (pi->alive_cmds != pi->stopped_cmds)
7374 /* All processes in fg pipe have exited or stopped */
7378 rcode = pi->cmds[i].cmd_exitcode;
7379 /* usually last process gives overall exitstatus,
7380 * but with "set -o pipefail", last *failed* process does */
7381 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7384 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7388 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7395 dead = WIFEXITED(status) || WIFSIGNALED(status);
7398 if (WIFSTOPPED(status))
7399 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7400 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7401 if (WIFSIGNALED(status))
7402 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7403 childpid, WTERMSIG(status), WEXITSTATUS(status));
7404 if (WIFEXITED(status))
7405 debug_printf_jobs("pid %d exited, exitcode %d\n",
7406 childpid, WEXITSTATUS(status));
7408 /* Were we asked to wait for a fg pipe? */
7410 i = fg_pipe->num_cmds;
7415 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7416 if (fg_pipe->cmds[i].pid != childpid)
7420 fg_pipe->cmds[i].pid = 0;
7421 fg_pipe->alive_cmds--;
7422 ex = WEXITSTATUS(status);
7423 /* bash prints killer signal's name for *last*
7424 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7425 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7427 if (WIFSIGNALED(status)) {
7428 int sig = WTERMSIG(status);
7429 if (i == fg_pipe->num_cmds-1)
7430 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7431 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7432 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7433 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7434 * Maybe we need to use sig | 128? */
7437 fg_pipe->cmds[i].cmd_exitcode = ex;
7439 fg_pipe->stopped_cmds++;
7441 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7442 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7443 rcode = job_exited_or_stopped(fg_pipe);
7445 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7446 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7447 * and "killall -STOP cat" */
7448 if (G_interactive_fd) {
7450 if (fg_pipe->alive_cmds != 0)
7451 insert_job_into_table(fg_pipe);
7455 if (fg_pipe->alive_cmds == 0)
7458 /* There are still running processes in the fg_pipe */
7461 /* It wasn't in fg_pipe, look for process in bg pipes */
7465 /* We were asked to wait for bg or orphaned children */
7466 /* No need to remember exitcode in this case */
7467 for (pi = G.job_list; pi; pi = pi->next) {
7468 for (i = 0; i < pi->num_cmds; i++) {
7469 if (pi->cmds[i].pid == childpid)
7470 goto found_pi_and_prognum;
7473 /* Happens when shell is used as init process (init=/bin/sh) */
7474 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7475 return -1; /* this wasn't a process from fg_pipe */
7477 found_pi_and_prognum:
7480 int rcode = WEXITSTATUS(status);
7481 if (WIFSIGNALED(status))
7482 rcode = 128 + WTERMSIG(status);
7483 pi->cmds[i].cmd_exitcode = rcode;
7484 if (G.last_bg_pid == pi->cmds[i].pid)
7485 G.last_bg_pid_exitcode = rcode;
7486 pi->cmds[i].pid = 0;
7488 if (!pi->alive_cmds) {
7489 if (G_interactive_fd) {
7490 printf(JOB_STATUS_FORMAT, pi->jobid,
7491 "Done", pi->cmdtext);
7492 delete_finished_job(pi);
7495 * bash deletes finished jobs from job table only in interactive mode,
7496 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7497 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7498 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7499 * We only retain one "dead" job, if it's the single job on the list.
7500 * This covers most of real-world scenarios where this is useful.
7502 if (pi != G.job_list)
7503 delete_finished_job(pi);
7511 return -1; /* this wasn't a process from fg_pipe */
7514 /* Check to see if any processes have exited -- if they have,
7515 * figure out why and see if a job has completed.
7517 * If non-NULL fg_pipe: wait for its completion or stop.
7518 * Return its exitcode or zero if stopped.
7520 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7521 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7522 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7523 * or 0 if no children changed status.
7525 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7526 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7527 * or 0 if no children changed status.
7529 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7535 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7537 attributes = WUNTRACED;
7538 if (fg_pipe == NULL)
7539 attributes |= WNOHANG;
7542 #if ENABLE_HUSH_FAST
7543 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7544 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7545 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7546 /* There was neither fork nor SIGCHLD since last waitpid */
7547 /* Avoid doing waitpid syscall if possible */
7548 if (!G.we_have_children) {
7552 if (fg_pipe == NULL) { /* is WNOHANG set? */
7553 /* We have children, but they did not exit
7554 * or stop yet (we saw no SIGCHLD) */
7557 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7561 /* Do we do this right?
7562 * bash-3.00# sleep 20 | false
7564 * [3]+ Stopped sleep 20 | false
7565 * bash-3.00# echo $?
7566 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7567 * [hush 1.14.0: yes we do it right]
7571 #if ENABLE_HUSH_FAST
7573 i = G.count_SIGCHLD;
7575 childpid = waitpid(-1, &status, attributes);
7576 if (childpid <= 0) {
7577 if (childpid && errno != ECHILD)
7578 bb_perror_msg("waitpid");
7579 #if ENABLE_HUSH_FAST
7580 else { /* Until next SIGCHLD, waitpid's are useless */
7581 G.we_have_children = (childpid == 0);
7582 G.handled_SIGCHLD = i;
7583 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7586 /* ECHILD (no children), or 0 (no change in children status) */
7590 rcode = process_wait_result(fg_pipe, childpid, status);
7592 /* fg_pipe exited or stopped */
7595 if (childpid == waitfor_pid) {
7596 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7597 rcode = WEXITSTATUS(status);
7598 if (WIFSIGNALED(status))
7599 rcode = 128 + WTERMSIG(status);
7600 if (WIFSTOPPED(status))
7601 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7602 rcode = 128 + WSTOPSIG(status);
7604 break; /* "wait PID" called us, give it exitcode+1 */
7606 /* This wasn't one of our processes, or */
7607 /* fg_pipe still has running processes, do waitpid again */
7608 } /* while (waitpid succeeds)... */
7614 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7617 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7618 if (G_saved_tty_pgrp) {
7619 /* Job finished, move the shell to the foreground */
7620 p = getpgrp(); /* our process group id */
7621 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7622 tcsetpgrp(G_interactive_fd, p);
7628 /* Start all the jobs, but don't wait for anything to finish.
7631 * Return code is normally -1, when the caller has to wait for children
7632 * to finish to determine the exit status of the pipe. If the pipe
7633 * is a simple builtin command, however, the action is done by the
7634 * time run_pipe returns, and the exit code is provided as the
7637 * Returns -1 only if started some children. IOW: we have to
7638 * mask out retvals of builtins etc with 0xff!
7640 * The only case when we do not need to [v]fork is when the pipe
7641 * is single, non-backgrounded, non-subshell command. Examples:
7642 * cmd ; ... { list } ; ...
7643 * cmd && ... { list } && ...
7644 * cmd || ... { list } || ...
7645 * If it is, then we can run cmd as a builtin, NOFORK,
7646 * or (if SH_STANDALONE) an applet, and we can run the { list }
7647 * with run_list. If it isn't one of these, we fork and exec cmd.
7649 * Cases when we must fork:
7650 * non-single: cmd | cmd
7651 * backgrounded: cmd & { list } &
7652 * subshell: ( list ) [&]
7654 #if !ENABLE_HUSH_MODE_X
7655 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7656 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7658 static int redirect_and_varexp_helper(char ***new_env_p,
7659 struct variable **old_vars_p,
7660 struct command *command,
7661 struct squirrel **sqp,
7662 char **argv_expanded)
7664 /* setup_redirects acts on file descriptors, not FILEs.
7665 * This is perfect for work that comes after exec().
7666 * Is it really safe for inline use? Experimentally,
7667 * things seem to work. */
7668 int rcode = setup_redirects(command, sqp);
7670 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7671 *new_env_p = new_env;
7672 dump_cmd_in_x_mode(new_env);
7673 dump_cmd_in_x_mode(argv_expanded);
7675 *old_vars_p = set_vars_and_save_old(new_env);
7679 static NOINLINE int run_pipe(struct pipe *pi)
7681 static const char *const null_ptr = NULL;
7685 struct command *command;
7686 char **argv_expanded;
7688 struct squirrel *squirrel = NULL;
7691 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7694 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7695 * Result should be 3 lines: q w e, qwe, q w e
7697 G.ifs = get_local_var_value("IFS");
7701 IF_HUSH_JOB(pi->pgrp = -1;)
7702 pi->stopped_cmds = 0;
7703 command = &pi->cmds[0];
7704 argv_expanded = NULL;
7706 if (pi->num_cmds != 1
7707 || pi->followup == PIPE_BG
7708 || command->cmd_type == CMD_SUBSHELL
7715 debug_printf_exec(": group:%p argv:'%s'\n",
7716 command->group, command->argv ? command->argv[0] : "NONE");
7718 if (command->group) {
7719 #if ENABLE_HUSH_FUNCTIONS
7720 if (command->cmd_type == CMD_FUNCDEF) {
7721 /* "executing" func () { list } */
7722 struct function *funcp;
7724 funcp = new_function(command->argv[0]);
7725 /* funcp->name is already set to argv[0] */
7726 funcp->body = command->group;
7728 funcp->body_as_string = command->group_as_string;
7729 command->group_as_string = NULL;
7731 command->group = NULL;
7732 command->argv[0] = NULL;
7733 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7734 funcp->parent_cmd = command;
7735 command->child_func = funcp;
7737 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7739 return EXIT_SUCCESS;
7743 debug_printf("non-subshell group\n");
7744 rcode = 1; /* exitcode if redir failed */
7745 if (setup_redirects(command, &squirrel) == 0) {
7746 debug_printf_exec(": run_list\n");
7747 rcode = run_list(command->group) & 0xff;
7749 restore_redirects(squirrel);
7750 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7752 debug_printf_exec("run_pipe: return %d\n", rcode);
7756 argv = command->argv ? command->argv : (char **) &null_ptr;
7758 const struct built_in_command *x;
7759 #if ENABLE_HUSH_FUNCTIONS
7760 const struct function *funcp;
7764 char **new_env = NULL;
7765 struct variable *old_vars = NULL;
7767 if (argv[command->assignment_cnt] == NULL) {
7768 /* Assignments, but no command */
7769 /* Ensure redirects take effect (that is, create files).
7770 * Try "a=t >file" */
7771 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7772 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7773 /* Set shell variables */
7777 if (set_local_var(*argv, /*flag:*/ 0)) {
7778 /* assignment to readonly var / putenv error? */
7784 /* Redirect error sets $? to 1. Otherwise,
7785 * if evaluating assignment value set $?, retain it.
7786 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7788 rcode = G.last_exitcode;
7789 /* Exit, _skipping_ variable restoring code: */
7790 goto clean_up_and_ret0;
7792 #else /* Older, bigger, but more correct code */
7794 rcode = setup_redirects(command, &squirrel);
7795 restore_redirects(squirrel);
7796 /* Set shell variables */
7798 bb_putchar_stderr('+');
7800 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7802 fprintf(stderr, " %s", p);
7803 debug_printf_exec("set shell var:'%s'->'%s'\n",
7805 if (set_local_var(p, /*flag:*/ 0)) {
7806 /* assignment to readonly var / putenv error? */
7812 bb_putchar_stderr('\n');
7813 /* Redirect error sets $? to 1. Otherwise,
7814 * if evaluating assignment value set $?, retain it.
7815 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7817 rcode = G.last_exitcode;
7818 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7820 debug_printf_exec("run_pipe: return %d\n", rcode);
7825 /* Expand the rest into (possibly) many strings each */
7827 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7828 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7832 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7835 /* if someone gives us an empty string: `cmd with empty output` */
7836 if (!argv_expanded[0]) {
7837 free(argv_expanded);
7839 return G.last_exitcode;
7842 x = find_builtin(argv_expanded[0]);
7843 #if ENABLE_HUSH_FUNCTIONS
7846 funcp = find_function(argv_expanded[0]);
7850 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7851 debug_printf("exec with redirects only\n");
7852 rcode = setup_redirects(command, NULL);
7853 /* rcode=1 can be if redir file can't be opened */
7854 goto clean_up_and_ret1;
7857 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7860 debug_printf_exec(": builtin '%s' '%s'...\n",
7861 x->b_cmd, argv_expanded[1]);
7863 rcode = x->b_function(argv_expanded) & 0xff;
7866 #if ENABLE_HUSH_FUNCTIONS
7868 # if ENABLE_HUSH_LOCAL
7869 struct variable **sv;
7870 sv = G.shadowed_vars_pp;
7871 G.shadowed_vars_pp = &old_vars;
7873 debug_printf_exec(": function '%s' '%s'...\n",
7874 funcp->name, argv_expanded[1]);
7875 rcode = run_function(funcp, argv_expanded) & 0xff;
7876 # if ENABLE_HUSH_LOCAL
7877 G.shadowed_vars_pp = sv;
7883 unset_vars(new_env);
7885 /* clean_up_and_ret0: */
7886 restore_redirects(squirrel);
7888 free(argv_expanded);
7889 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7891 debug_printf_exec("run_pipe return %d\n", rcode);
7895 if (ENABLE_FEATURE_SH_NOFORK) {
7896 int n = find_applet_by_name(argv_expanded[0]);
7897 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7898 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7900 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7901 argv_expanded[0], argv_expanded[1]);
7902 rcode = run_nofork_applet(n, argv_expanded);
7904 goto clean_up_and_ret;
7907 /* It is neither builtin nor applet. We must fork. */
7911 /* NB: argv_expanded may already be created, and that
7912 * might include `cmd` runs! Do not rerun it! We *must*
7913 * use argv_expanded if it's non-NULL */
7915 /* Going to fork a child per each pipe member */
7920 while (cmd_no < pi->num_cmds) {
7921 struct fd_pair pipefds;
7923 volatile nommu_save_t nommu_save;
7924 nommu_save.new_env = NULL;
7925 nommu_save.old_vars = NULL;
7926 nommu_save.argv = NULL;
7927 nommu_save.argv_from_re_execing = NULL;
7929 command = &pi->cmds[cmd_no];
7931 if (command->argv) {
7932 debug_printf_exec(": pipe member '%s' '%s'...\n",
7933 command->argv[0], command->argv[1]);
7935 debug_printf_exec(": pipe member with no argv\n");
7938 /* pipes are inserted between pairs of commands */
7941 if (cmd_no < pi->num_cmds)
7942 xpiped_pair(pipefds);
7944 command->pid = BB_MMU ? fork() : vfork();
7945 if (!command->pid) { /* child */
7947 disable_restore_tty_pgrp_on_exit();
7948 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7950 /* Every child adds itself to new process group
7951 * with pgid == pid_of_first_child_in_pipe */
7952 if (G.run_list_level == 1 && G_interactive_fd) {
7955 if (pgrp < 0) /* true for 1st process only */
7957 if (setpgid(0, pgrp) == 0
7958 && pi->followup != PIPE_BG
7959 && G_saved_tty_pgrp /* we have ctty */
7961 /* We do it in *every* child, not just first,
7963 tcsetpgrp(G_interactive_fd, pgrp);
7967 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7968 /* 1st cmd in backgrounded pipe
7969 * should have its stdin /dev/null'ed */
7971 if (open(bb_dev_null, O_RDONLY))
7972 xopen("/", O_RDONLY);
7974 xmove_fd(next_infd, 0);
7976 xmove_fd(pipefds.wr, 1);
7979 /* Like bash, explicit redirects override pipes,
7980 * and the pipe fd (fd#1) is available for dup'ing:
7981 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7982 * of cmd1 goes into pipe.
7984 if (setup_redirects(command, NULL)) {
7985 /* Happens when redir file can't be opened:
7986 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7988 * hush: can't open '/qwe/rty': No such file or directory
7990 * (echo BAR is not executed, it hits _exit(1) below)
7995 /* Stores to nommu_save list of env vars putenv'ed
7996 * (NOMMU, on MMU we don't need that) */
7997 /* cast away volatility... */
7998 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7999 /* pseudo_exec() does not return */
8002 /* parent or error */
8003 #if ENABLE_HUSH_FAST
8005 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8007 enable_restore_tty_pgrp_on_exit();
8009 /* Clean up after vforked child */
8010 free(nommu_save.argv);
8011 free(nommu_save.argv_from_re_execing);
8012 unset_vars(nommu_save.new_env);
8013 add_vars(nommu_save.old_vars);
8015 free(argv_expanded);
8016 argv_expanded = NULL;
8017 if (command->pid < 0) { /* [v]fork failed */
8018 /* Clearly indicate, was it fork or vfork */
8019 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8023 /* Second and next children need to know pid of first one */
8025 pi->pgrp = command->pid;
8031 if (cmd_no < pi->num_cmds)
8033 /* Pass read (output) pipe end to next iteration */
8034 next_infd = pipefds.rd;
8037 if (!pi->alive_cmds) {
8039 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8044 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8048 /* NB: called by pseudo_exec, and therefore must not modify any
8049 * global data until exec/_exit (we can be a child after vfork!) */
8050 static int run_list(struct pipe *pi)
8052 #if ENABLE_HUSH_CASE
8053 char *case_word = NULL;
8055 #if ENABLE_HUSH_LOOPS
8056 struct pipe *loop_top = NULL;
8057 char **for_lcur = NULL;
8058 char **for_list = NULL;
8060 smallint last_followup;
8062 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8063 smalluint cond_code = 0;
8065 enum { cond_code = 0 };
8068 smallint rword; /* RES_foo */
8069 smallint last_rword; /* ditto */
8072 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8075 #if ENABLE_HUSH_LOOPS
8076 /* Check syntax for "for" */
8079 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8080 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8082 /* current word is FOR or IN (BOLD in comments below) */
8083 if (cpipe->next == NULL) {
8084 syntax_error("malformed for");
8086 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8089 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8090 if (cpipe->next->res_word == RES_DO)
8092 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8093 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8094 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8096 syntax_error("malformed for");
8098 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8105 /* Past this point, all code paths should jump to ret: label
8106 * in order to return, no direct "return" statements please.
8107 * This helps to ensure that no memory is leaked. */
8115 last_rword = RES_XXXX;
8117 last_followup = PIPE_SEQ;
8118 rcode = G.last_exitcode;
8120 /* Go through list of pipes, (maybe) executing them. */
8121 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8123 int sv_errexit_depth;
8127 if (G_flag_return_in_progress == 1)
8130 IF_HAS_KEYWORDS(rword = pi->res_word;)
8131 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8132 rword, cond_code, last_rword);
8134 sv_errexit_depth = G.errexit_depth;
8135 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8136 pi->followup != PIPE_SEQ
8140 #if ENABLE_HUSH_LOOPS
8141 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8142 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8144 /* start of a loop: remember where loop starts */
8149 /* Still in the same "if...", "then..." or "do..." branch? */
8150 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8151 if ((rcode == 0 && last_followup == PIPE_OR)
8152 || (rcode != 0 && last_followup == PIPE_AND)
8154 /* It is "<true> || CMD" or "<false> && CMD"
8155 * and we should not execute CMD */
8156 debug_printf_exec("skipped cmd because of || or &&\n");
8157 last_followup = pi->followup;
8158 goto dont_check_jobs_but_continue;
8161 last_followup = pi->followup;
8162 IF_HAS_KEYWORDS(last_rword = rword;)
8165 if (rword == RES_THEN) {
8166 /* if false; then ... fi has exitcode 0! */
8167 G.last_exitcode = rcode = EXIT_SUCCESS;
8168 /* "if <false> THEN cmd": skip cmd */
8172 if (rword == RES_ELSE || rword == RES_ELIF) {
8173 /* "if <true> then ... ELSE/ELIF cmd":
8174 * skip cmd and all following ones */
8179 #if ENABLE_HUSH_LOOPS
8180 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8182 /* first loop through for */
8184 static const char encoded_dollar_at[] ALIGN1 = {
8185 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8186 }; /* encoded representation of "$@" */
8187 static const char *const encoded_dollar_at_argv[] = {
8188 encoded_dollar_at, NULL
8189 }; /* argv list with one element: "$@" */
8192 vals = (char**)encoded_dollar_at_argv;
8193 if (pi->next->res_word == RES_IN) {
8194 /* if no variable values after "in" we skip "for" */
8195 if (!pi->next->cmds[0].argv) {
8196 G.last_exitcode = rcode = EXIT_SUCCESS;
8197 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8200 vals = pi->next->cmds[0].argv;
8201 } /* else: "for var; do..." -> assume "$@" list */
8202 /* create list of variable values */
8203 debug_print_strings("for_list made from", vals);
8204 for_list = expand_strvec_to_strvec(vals);
8205 for_lcur = for_list;
8206 debug_print_strings("for_list", for_list);
8209 /* "for" loop is over, clean up */
8215 /* Insert next value from for_lcur */
8216 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8217 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8220 if (rword == RES_IN) {
8221 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8223 if (rword == RES_DONE) {
8224 continue; /* "done" has no cmds too */
8227 #if ENABLE_HUSH_CASE
8228 if (rword == RES_CASE) {
8229 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8230 case_word = expand_strvec_to_string(pi->cmds->argv);
8231 unbackslash(case_word);
8234 if (rword == RES_MATCH) {
8237 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8238 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8240 /* all prev words didn't match, does this one match? */
8241 argv = pi->cmds->argv;
8243 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8244 /* TODO: which FNM_xxx flags to use? */
8245 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8246 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8248 if (cond_code == 0) { /* match! we will execute this branch */
8250 case_word = NULL; /* make future "word)" stop */
8257 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8258 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8260 continue; /* not matched yet, skip this pipe */
8262 if (rword == RES_ESAC) {
8263 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8265 /* "case" did not match anything: still set $? (to 0) */
8266 G.last_exitcode = rcode = EXIT_SUCCESS;
8270 /* Just pressing <enter> in shell should check for jobs.
8271 * OTOH, in non-interactive shell this is useless
8272 * and only leads to extra job checks */
8273 if (pi->num_cmds == 0) {
8274 if (G_interactive_fd)
8275 goto check_jobs_and_continue;
8279 /* After analyzing all keywords and conditions, we decided
8280 * to execute this pipe. NB: have to do checkjobs(NULL)
8281 * after run_pipe to collect any background children,
8282 * even if list execution is to be stopped. */
8283 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8284 #if ENABLE_HUSH_LOOPS
8285 G.flag_break_continue = 0;
8287 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8289 /* We ran a builtin, function, or group.
8290 * rcode is already known
8291 * and we don't need to wait for anything. */
8292 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8293 G.last_exitcode = rcode;
8294 check_and_run_traps();
8295 #if ENABLE_HUSH_LOOPS
8296 /* Was it "break" or "continue"? */
8297 if (G.flag_break_continue) {
8298 smallint fbc = G.flag_break_continue;
8299 /* We might fall into outer *loop*,
8300 * don't want to break it too */
8302 G.depth_break_continue--;
8303 if (G.depth_break_continue == 0)
8304 G.flag_break_continue = 0;
8305 /* else: e.g. "continue 2" should *break* once, *then* continue */
8306 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8307 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8308 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8311 /* "continue": simulate end of loop */
8316 if (G_flag_return_in_progress == 1) {
8317 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8320 } else if (pi->followup == PIPE_BG) {
8321 /* What does bash do with attempts to background builtins? */
8322 /* even bash 3.2 doesn't do that well with nested bg:
8323 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8324 * I'm NOT treating inner &'s as jobs */
8326 if (G.run_list_level == 1)
8327 insert_job_into_table(pi);
8329 /* Last command's pid goes to $! */
8330 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8331 G.last_bg_pid_exitcode = 0;
8332 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8333 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8334 rcode = EXIT_SUCCESS;
8338 if (G.run_list_level == 1 && G_interactive_fd) {
8339 /* Waits for completion, then fg's main shell */
8340 rcode = checkjobs_and_fg_shell(pi);
8341 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8345 /* This one just waits for completion */
8346 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8347 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8349 G.last_exitcode = rcode;
8350 check_and_run_traps();
8353 /* Handle "set -e" */
8354 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8355 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8356 if (G.errexit_depth == 0)
8359 G.errexit_depth = sv_errexit_depth;
8361 /* Analyze how result affects subsequent commands */
8363 if (rword == RES_IF || rword == RES_ELIF)
8366 check_jobs_and_continue:
8367 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8368 dont_check_jobs_but_continue: ;
8369 #if ENABLE_HUSH_LOOPS
8370 /* Beware of "while false; true; do ..."! */
8372 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8373 /* check for RES_DONE is needed for "while ...; do \n done" case */
8375 if (rword == RES_WHILE) {
8377 /* "while false; do...done" - exitcode 0 */
8378 G.last_exitcode = rcode = EXIT_SUCCESS;
8379 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8383 if (rword == RES_UNTIL) {
8385 debug_printf_exec(": until expr is true: breaking\n");
8396 #if ENABLE_HUSH_LOOPS
8401 #if ENABLE_HUSH_CASE
8405 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8409 /* Select which version we will use */
8410 static int run_and_free_list(struct pipe *pi)
8413 debug_printf_exec("run_and_free_list entered\n");
8414 if (!G.o_opt[OPT_O_NOEXEC]) {
8415 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8416 rcode = run_list(pi);
8418 /* free_pipe_list has the side effect of clearing memory.
8419 * In the long run that function can be merged with run_list,
8420 * but doing that now would hobble the debugging effort. */
8422 debug_printf_exec("run_and_free_list return %d\n", rcode);
8427 static void install_sighandlers(unsigned mask)
8429 sighandler_t old_handler;
8431 while ((mask >>= 1) != 0) {
8435 old_handler = install_sighandler(sig, pick_sighandler(sig));
8436 /* POSIX allows shell to re-enable SIGCHLD
8437 * even if it was SIG_IGN on entry.
8438 * Therefore we skip IGN check for it:
8442 if (old_handler == SIG_IGN) {
8443 /* oops... restore back to IGN, and record this fact */
8444 install_sighandler(sig, old_handler);
8445 #if ENABLE_HUSH_TRAP
8447 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8449 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8455 /* Called a few times only (or even once if "sh -c") */
8456 static void install_special_sighandlers(void)
8460 /* Which signals are shell-special? */
8461 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8462 if (G_interactive_fd) {
8463 mask |= SPECIAL_INTERACTIVE_SIGS;
8464 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8465 mask |= SPECIAL_JOBSTOP_SIGS;
8467 /* Careful, do not re-install handlers we already installed */
8468 if (G.special_sig_mask != mask) {
8469 unsigned diff = mask & ~G.special_sig_mask;
8470 G.special_sig_mask = mask;
8471 install_sighandlers(diff);
8477 /* Set handlers to restore tty pgrp and exit */
8478 static void install_fatal_sighandlers(void)
8482 /* We will restore tty pgrp on these signals */
8484 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8485 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8486 + (1 << SIGBUS ) * HUSH_DEBUG
8487 + (1 << SIGSEGV) * HUSH_DEBUG
8488 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8490 /* bash 3.2 seems to handle these just like 'fatal' ones */
8493 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8494 * if we aren't interactive... but in this case
8495 * we never want to restore pgrp on exit, and this fn is not called
8497 /*+ (1 << SIGHUP )*/
8498 /*+ (1 << SIGTERM)*/
8499 /*+ (1 << SIGINT )*/
8501 G_fatal_sig_mask = mask;
8503 install_sighandlers(mask);
8507 static int set_mode(int state, char mode, const char *o_opt)
8512 G.o_opt[OPT_O_NOEXEC] = state;
8515 IF_HUSH_MODE_X(G_x_mode = state;)
8519 /* "set -+o" without parameter.
8520 * in bash, set -o produces this output:
8524 * We always use the second form.
8526 const char *p = o_opt_strings;
8529 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8535 idx = index_in_strings(o_opt_strings, o_opt);
8537 G.o_opt[idx] = state;
8541 G.o_opt[OPT_O_ERREXIT] = state;
8544 return EXIT_FAILURE;
8546 return EXIT_SUCCESS;
8549 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8550 int hush_main(int argc, char **argv)
8553 OPT_login = (1 << 0),
8557 unsigned builtin_argc;
8559 struct variable *cur_var;
8560 struct variable *shell_ver;
8563 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8564 G.last_exitcode = EXIT_SUCCESS;
8566 #if ENABLE_HUSH_FAST
8567 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8570 G.argv0_for_re_execing = argv[0];
8572 /* Deal with HUSH_VERSION */
8573 shell_ver = xzalloc(sizeof(*shell_ver));
8574 shell_ver->flg_export = 1;
8575 shell_ver->flg_read_only = 1;
8576 /* Code which handles ${var<op>...} needs writable values for all variables,
8577 * therefore we xstrdup: */
8578 shell_ver->varstr = xstrdup(hush_version_str);
8579 /* Create shell local variables from the values
8580 * currently living in the environment */
8581 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8582 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8583 G.top_var = shell_ver;
8584 cur_var = G.top_var;
8587 char *value = strchr(*e, '=');
8588 if (value) { /* paranoia */
8589 cur_var->next = xzalloc(sizeof(*cur_var));
8590 cur_var = cur_var->next;
8591 cur_var->varstr = *e;
8592 cur_var->max_len = strlen(*e);
8593 cur_var->flg_export = 1;
8597 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8598 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8599 putenv(shell_ver->varstr);
8602 set_pwd_var(SETFLAG_EXPORT);
8604 #if BASH_HOSTNAME_VAR
8605 /* Set (but not export) HOSTNAME unless already set */
8606 if (!get_local_var_value("HOSTNAME")) {
8609 set_local_var_from_halves("HOSTNAME", uts.nodename);
8611 /* bash also exports SHLVL and _,
8612 * and sets (but doesn't export) the following variables:
8614 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8615 * BASH_VERSION='3.2.0(1)-release'
8617 * MACHTYPE=i386-pc-linux-gnu
8619 * PPID=<NNNNN> - we also do it elsewhere
8630 * PIPESTATUS=([0]="0")
8631 * HISTFILE=/<xxx>/.bash_history
8635 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8637 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8648 #if ENABLE_FEATURE_EDITING
8649 G.line_input_state = new_line_input_t(FOR_SHELL);
8652 /* Initialize some more globals to non-zero values */
8653 cmdedit_update_prompt();
8655 die_func = restore_ttypgrp_and__exit;
8657 /* Shell is non-interactive at first. We need to call
8658 * install_special_sighandlers() if we are going to execute "sh <script>",
8659 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8660 * If we later decide that we are interactive, we run install_special_sighandlers()
8661 * in order to intercept (more) signals.
8665 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8666 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8669 opt = getopt(argc, argv, "+c:exinsl"
8672 # if ENABLE_HUSH_FUNCTIONS
8682 * sh ... -c 'script'
8683 * sh ... -c 'script' ARG0 [ARG1...]
8684 * On NOMMU, if builtin_argc != 0,
8685 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8686 * "" needs to be replaced with NULL
8687 * and BARGV vector fed to builtin function.
8688 * Note: the form without ARG0 never happens:
8689 * sh ... -c 'builtin' BARGV... ""
8692 G.root_pid = getpid();
8693 G.root_ppid = getppid();
8695 G.global_argv = argv + optind;
8696 G.global_argc = argc - optind;
8698 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8699 const struct built_in_command *x;
8701 install_special_sighandlers();
8702 x = find_builtin(optarg);
8703 if (x) { /* paranoia */
8704 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8705 G.global_argv += builtin_argc;
8706 G.global_argv[-1] = NULL; /* replace "" */
8708 G.last_exitcode = x->b_function(argv + optind - 1);
8712 if (!G.global_argv[0]) {
8713 /* -c 'script' (no params): prevent empty $0 */
8714 G.global_argv--; /* points to argv[i] of 'script' */
8715 G.global_argv[0] = argv[0];
8717 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8718 install_special_sighandlers();
8719 parse_and_run_string(optarg);
8722 /* Well, we cannot just declare interactiveness,
8723 * we have to have some stuff (ctty, etc) */
8724 /* G_interactive_fd++; */
8727 /* "-s" means "read from stdin", but this is how we always
8728 * operate, so simply do nothing here. */
8734 case '<': /* "big heredoc" support */
8735 full_write1_str(optarg);
8738 unsigned long long empty_trap_mask;
8740 G.root_pid = bb_strtou(optarg, &optarg, 16);
8742 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8744 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8746 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8748 builtin_argc = bb_strtou(optarg, &optarg, 16);
8750 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8751 if (empty_trap_mask != 0) {
8752 IF_HUSH_TRAP(int sig;)
8753 install_special_sighandlers();
8754 # if ENABLE_HUSH_TRAP
8755 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8756 for (sig = 1; sig < NSIG; sig++) {
8757 if (empty_trap_mask & (1LL << sig)) {
8758 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8759 install_sighandler(sig, SIG_IGN);
8764 # if ENABLE_HUSH_LOOPS
8766 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8772 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8774 # if ENABLE_HUSH_FUNCTIONS
8776 struct function *funcp = new_function(optarg);
8777 /* funcp->name is already set to optarg */
8778 /* funcp->body is set to NULL. It's a special case. */
8779 funcp->body_as_string = argv[optind];
8788 if (set_mode(1, opt, NULL) == 0) /* no error */
8792 fprintf(stderr, "Usage: sh [FILE]...\n"
8793 " or: sh -c command [args]...\n\n");
8799 } /* option parsing loop */
8801 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8802 G.global_argc = argc - (optind - 1);
8803 G.global_argv = argv + (optind - 1);
8804 G.global_argv[0] = argv[0];
8807 G.root_pid = getpid();
8808 G.root_ppid = getppid();
8811 /* If we are login shell... */
8812 if (flags & OPT_login) {
8814 debug_printf("sourcing /etc/profile\n");
8815 input = fopen_for_read("/etc/profile");
8816 if (input != NULL) {
8817 remember_FILE(input);
8818 install_special_sighandlers();
8819 parse_and_run_file(input);
8820 fclose_and_forget(input);
8822 /* bash: after sourcing /etc/profile,
8823 * tries to source (in the given order):
8824 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8825 * stopping on first found. --noprofile turns this off.
8826 * bash also sources ~/.bash_logout on exit.
8827 * If called as sh, skips .bash_XXX files.
8831 if (G.global_argv[1]) {
8834 * "bash <script>" (which is never interactive (unless -i?))
8835 * sources $BASH_ENV here (without scanning $PATH).
8836 * If called as sh, does the same but with $ENV.
8837 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8841 debug_printf("running script '%s'\n", G.global_argv[0]);
8842 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8843 input = xfopen_for_read(G.global_argv[0]);
8844 xfunc_error_retval = 1;
8845 remember_FILE(input);
8846 install_special_sighandlers();
8847 parse_and_run_file(input);
8848 #if ENABLE_FEATURE_CLEAN_UP
8849 fclose_and_forget(input);
8854 /* Up to here, shell was non-interactive. Now it may become one.
8855 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8858 /* A shell is interactive if the '-i' flag was given,
8859 * or if all of the following conditions are met:
8861 * no arguments remaining or the -s flag given
8862 * standard input is a terminal
8863 * standard output is a terminal
8864 * Refer to Posix.2, the description of the 'sh' utility.
8867 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8868 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8869 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8870 if (G_saved_tty_pgrp < 0)
8871 G_saved_tty_pgrp = 0;
8873 /* try to dup stdin to high fd#, >= 255 */
8874 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8875 if (G_interactive_fd < 0) {
8876 /* try to dup to any fd */
8877 G_interactive_fd = dup(STDIN_FILENO);
8878 if (G_interactive_fd < 0) {
8880 G_interactive_fd = 0;
8881 G_saved_tty_pgrp = 0;
8884 // TODO: track & disallow any attempts of user
8885 // to (inadvertently) close/redirect G_interactive_fd
8887 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8888 if (G_interactive_fd) {
8889 close_on_exec_on(G_interactive_fd);
8891 if (G_saved_tty_pgrp) {
8892 /* If we were run as 'hush &', sleep until we are
8893 * in the foreground (tty pgrp == our pgrp).
8894 * If we get started under a job aware app (like bash),
8895 * make sure we are now in charge so we don't fight over
8896 * who gets the foreground */
8898 pid_t shell_pgrp = getpgrp();
8899 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8900 if (G_saved_tty_pgrp == shell_pgrp)
8902 /* send TTIN to ourself (should stop us) */
8903 kill(- shell_pgrp, SIGTTIN);
8907 /* Install more signal handlers */
8908 install_special_sighandlers();
8910 if (G_saved_tty_pgrp) {
8911 /* Set other signals to restore saved_tty_pgrp */
8912 install_fatal_sighandlers();
8913 /* Put ourselves in our own process group
8914 * (bash, too, does this only if ctty is available) */
8915 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8916 /* Grab control of the terminal */
8917 tcsetpgrp(G_interactive_fd, getpid());
8919 enable_restore_tty_pgrp_on_exit();
8921 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8923 const char *hp = get_local_var_value("HISTFILE");
8925 hp = get_local_var_value("HOME");
8927 hp = concat_path_file(hp, ".hush_history");
8932 G.line_input_state->hist_file = hp;
8933 //set_local_var(xasprintf("HISTFILE=%s", ...));
8935 # if ENABLE_FEATURE_SH_HISTFILESIZE
8936 hp = get_local_var_value("HISTFILESIZE");
8937 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8942 install_special_sighandlers();
8944 #elif ENABLE_HUSH_INTERACTIVE
8945 /* No job control compiled in, only prompt/line editing */
8946 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8947 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8948 if (G_interactive_fd < 0) {
8949 /* try to dup to any fd */
8950 G_interactive_fd = dup(STDIN_FILENO);
8951 if (G_interactive_fd < 0)
8953 G_interactive_fd = 0;
8956 if (G_interactive_fd) {
8957 close_on_exec_on(G_interactive_fd);
8959 install_special_sighandlers();
8961 /* We have interactiveness code disabled */
8962 install_special_sighandlers();
8965 * if interactive but not a login shell, sources ~/.bashrc
8966 * (--norc turns this off, --rcfile <file> overrides)
8969 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8970 /* note: ash and hush share this string */
8971 printf("\n\n%s %s\n"
8972 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8975 "hush - the humble shell"
8979 parse_and_run_file(stdin);
8982 hush_exit(G.last_exitcode);
8989 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8994 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8995 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8997 int argc = string_array_len(argv);
8998 return applet_main_func(argc, argv);
9001 #if ENABLE_HUSH_TEST || BASH_TEST2
9002 static int FAST_FUNC builtin_test(char **argv)
9004 return run_applet_main(argv, test_main);
9007 #if ENABLE_HUSH_ECHO
9008 static int FAST_FUNC builtin_echo(char **argv)
9010 return run_applet_main(argv, echo_main);
9013 #if ENABLE_HUSH_PRINTF
9014 static int FAST_FUNC builtin_printf(char **argv)
9016 return run_applet_main(argv, printf_main);
9020 #if ENABLE_HUSH_HELP
9021 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9023 const struct built_in_command *x;
9026 "Built-in commands:\n"
9027 "------------------\n");
9028 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9030 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9032 return EXIT_SUCCESS;
9036 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9037 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9039 show_history(G.line_input_state);
9040 return EXIT_SUCCESS;
9044 static char **skip_dash_dash(char **argv)
9047 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9052 static int FAST_FUNC builtin_cd(char **argv)
9056 argv = skip_dash_dash(argv);
9058 if (newdir == NULL) {
9059 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9060 * bash says "bash: cd: HOME not set" and does nothing
9063 const char *home = get_local_var_value("HOME");
9064 newdir = home ? home : "/";
9066 if (chdir(newdir)) {
9067 /* Mimic bash message exactly */
9068 bb_perror_msg("cd: %s", newdir);
9069 return EXIT_FAILURE;
9071 /* Read current dir (get_cwd(1) is inside) and set PWD.
9072 * Note: do not enforce exporting. If PWD was unset or unexported,
9073 * set it again, but do not export. bash does the same.
9075 set_pwd_var(/*flag:*/ 0);
9076 return EXIT_SUCCESS;
9079 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9082 return EXIT_SUCCESS;
9085 static int FAST_FUNC builtin_eval(char **argv)
9087 int rcode = EXIT_SUCCESS;
9089 argv = skip_dash_dash(argv);
9091 char *str = expand_strvec_to_string(argv);
9093 * eval "echo Hi; done" ("done" is syntax error):
9094 * "echo Hi" will not execute too.
9096 parse_and_run_string(str);
9098 rcode = G.last_exitcode;
9103 static int FAST_FUNC builtin_exec(char **argv)
9105 argv = skip_dash_dash(argv);
9106 if (argv[0] == NULL)
9107 return EXIT_SUCCESS; /* bash does this */
9109 /* Careful: we can end up here after [v]fork. Do not restore
9110 * tty pgrp then, only top-level shell process does that */
9111 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9112 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9114 /* TODO: if exec fails, bash does NOT exit! We do.
9115 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9116 * and tcsetpgrp, and this is inherently racy.
9118 execvp_or_die(argv);
9121 static int FAST_FUNC builtin_exit(char **argv)
9123 debug_printf_exec("%s()\n", __func__);
9125 /* interactive bash:
9126 * # trap "echo EEE" EXIT
9129 * There are stopped jobs.
9130 * (if there are _stopped_ jobs, running ones don't count)
9133 * EEE (then bash exits)
9135 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9138 /* note: EXIT trap is run by hush_exit */
9139 argv = skip_dash_dash(argv);
9140 if (argv[0] == NULL)
9141 hush_exit(G.last_exitcode);
9142 /* mimic bash: exit 123abc == exit 255 + error msg */
9143 xfunc_error_retval = 255;
9144 /* bash: exit -2 == exit 254, no error msg */
9145 hush_exit(xatoi(argv[0]) & 0xff);
9148 #if ENABLE_HUSH_TYPE
9149 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9150 static int FAST_FUNC builtin_type(char **argv)
9152 int ret = EXIT_SUCCESS;
9158 if (0) {} /* make conditional compile easier below */
9159 /*else if (find_alias(*argv))
9160 type = "an alias";*/
9161 #if ENABLE_HUSH_FUNCTIONS
9162 else if (find_function(*argv))
9163 type = "a function";
9165 else if (find_builtin(*argv))
9166 type = "a shell builtin";
9167 else if ((path = find_in_path(*argv)) != NULL)
9170 bb_error_msg("type: %s: not found", *argv);
9175 printf("%s is %s\n", *argv, type);
9183 #if ENABLE_HUSH_READ
9184 /* Interruptibility of read builtin in bash
9185 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9187 * Empty trap makes read ignore corresponding signal, for any signal.
9190 * - terminates non-interactive shell;
9191 * - interrupts read in interactive shell;
9192 * if it has non-empty trap:
9193 * - executes trap and returns to command prompt in interactive shell;
9194 * - executes trap and returns to read in non-interactive shell;
9196 * - is ignored (does not interrupt) read in interactive shell;
9197 * - terminates non-interactive shell;
9198 * if it has non-empty trap:
9199 * - executes trap and returns to read;
9201 * - terminates shell (regardless of interactivity);
9202 * if it has non-empty trap:
9203 * - executes trap and returns to read;
9204 * SIGCHLD from children:
9205 * - does not interrupt read regardless of interactivity:
9206 * try: sleep 1 & read x; echo $x
9208 static int FAST_FUNC builtin_read(char **argv)
9218 /* "!": do not abort on errors.
9219 * Option string must start with "sr" to match BUILTIN_READ_xxx
9221 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9222 if (read_flags == (uint32_t)-1)
9223 return EXIT_FAILURE;
9225 ifs = get_local_var_value("IFS"); /* can be NULL */
9228 r = shell_builtin_read(set_local_var_from_halves,
9238 if ((uintptr_t)r == 1 && errno == EINTR) {
9239 unsigned sig = check_and_run_traps();
9244 if ((uintptr_t)r > 1) {
9245 bb_error_msg("%s", r);
9246 r = (char*)(uintptr_t)1;
9249 return (uintptr_t)r;
9253 #if ENABLE_HUSH_UMASK
9254 static int FAST_FUNC builtin_umask(char **argv)
9261 argv = skip_dash_dash(argv);
9263 mode_t old_mask = mask;
9265 /* numeric umasks are taken as-is */
9266 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9267 if (!isdigit(argv[0][0]))
9269 mask = bb_parse_mode(argv[0], mask);
9270 if (!isdigit(argv[0][0]))
9272 if ((unsigned)mask > 0777) {
9275 * bash: umask: 'q': invalid symbolic mode operator
9276 * bash: umask: 999: octal number out of range
9278 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9283 printf("%04o\n", (unsigned) mask);
9284 /* fall through and restore mask which we set to 0 */
9288 return !rc; /* rc != 0 - success */
9292 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9293 static void print_escaped(const char *s)
9298 const char *p = strchrnul(s, '\'');
9299 /* print 'xxxx', possibly just '' */
9300 printf("'%.*s'", (int)(p - s), s);
9305 /* s points to '; print "'''...'''" */
9307 do putchar('\''); while (*++s == '\'');
9313 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9314 static int helper_export_local(char **argv, unsigned flags)
9318 char *name_end = strchrnul(name, '=');
9320 /* So far we do not check that name is valid (TODO?) */
9322 if (*name_end == '\0') {
9323 struct variable *var, **vpp;
9325 vpp = get_ptr_to_local_var(name, name_end - name);
9326 var = vpp ? *vpp : NULL;
9328 if (flags & SETFLAG_UNEXPORT) {
9329 /* export -n NAME (without =VALUE) */
9331 var->flg_export = 0;
9332 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9334 } /* else: export -n NOT_EXISTING_VAR: no-op */
9337 if (flags & SETFLAG_EXPORT) {
9338 /* export NAME (without =VALUE) */
9340 var->flg_export = 1;
9341 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9342 putenv(var->varstr);
9346 if (flags & SETFLAG_MAKE_RO) {
9347 /* readonly NAME (without =VALUE) */
9349 var->flg_read_only = 1;
9353 # if ENABLE_HUSH_LOCAL
9354 /* Is this "local" bltin? */
9355 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9356 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9357 if (var && var->func_nest_level == lvl) {
9358 /* "local x=abc; ...; local x" - ignore second local decl */
9363 /* Exporting non-existing variable.
9364 * bash does not put it in environment,
9365 * but remembers that it is exported,
9366 * and does put it in env when it is set later.
9367 * We just set it to "" and export.
9369 /* Or, it's "local NAME" (without =VALUE).
9370 * bash sets the value to "".
9372 /* Or, it's "readonly NAME" (without =VALUE).
9373 * bash remembers NAME and disallows its creation
9376 name = xasprintf("%s=", name);
9378 /* (Un)exporting/making local NAME=VALUE */
9379 name = xstrdup(name);
9381 if (set_local_var(name, flags))
9382 return EXIT_FAILURE;
9384 return EXIT_SUCCESS;
9388 #if ENABLE_HUSH_EXPORT
9389 static int FAST_FUNC builtin_export(char **argv)
9391 unsigned opt_unexport;
9393 #if ENABLE_HUSH_EXPORT_N
9394 /* "!": do not abort on errors */
9395 opt_unexport = getopt32(argv, "!n");
9396 if (opt_unexport == (uint32_t)-1)
9397 return EXIT_FAILURE;
9404 if (argv[0] == NULL) {
9411 /* ash emits: export VAR='VAL'
9412 * bash: declare -x VAR="VAL"
9413 * we follow ash example */
9414 const char *s = *e++;
9415 const char *p = strchr(s, '=');
9417 if (!p) /* wtf? take next variable */
9420 printf("export %.*s", (int)(p - s) + 1, s);
9421 print_escaped(p + 1);
9425 /*fflush_all(); - done after each builtin anyway */
9427 return EXIT_SUCCESS;
9430 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9434 #if ENABLE_HUSH_LOCAL
9435 static int FAST_FUNC builtin_local(char **argv)
9437 if (G.func_nest_level == 0) {
9438 bb_error_msg("%s: not in a function", argv[0]);
9439 return EXIT_FAILURE; /* bash compat */
9442 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9446 #if ENABLE_HUSH_READONLY
9447 static int FAST_FUNC builtin_readonly(char **argv)
9450 if (*argv == NULL) {
9451 /* bash: readonly [-p]: list all readonly VARs
9452 * (-p has no effect in bash)
9455 for (e = G.top_var; e; e = e->next) {
9456 if (e->flg_read_only) {
9457 //TODO: quote value: readonly VAR='VAL'
9458 printf("readonly %s\n", e->varstr);
9461 return EXIT_SUCCESS;
9463 return helper_export_local(argv, SETFLAG_MAKE_RO);
9467 #if ENABLE_HUSH_UNSET
9468 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9469 static int FAST_FUNC builtin_unset(char **argv)
9474 /* "!": do not abort on errors */
9475 /* "+": stop at 1st non-option */
9476 opts = getopt32(argv, "!+vf");
9477 if (opts == (unsigned)-1)
9478 return EXIT_FAILURE;
9480 bb_error_msg("unset: -v and -f are exclusive");
9481 return EXIT_FAILURE;
9487 if (!(opts & 2)) { /* not -f */
9488 if (unset_local_var(*argv)) {
9489 /* unset <nonexistent_var> doesn't fail.
9490 * Error is when one tries to unset RO var.
9491 * Message was printed by unset_local_var. */
9495 # if ENABLE_HUSH_FUNCTIONS
9507 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9508 * built-in 'set' handler
9510 * set [-abCefhmnuvx] [-o option] [argument...]
9511 * set [+abCefhmnuvx] [+o option] [argument...]
9512 * set -- [argument...]
9515 * Implementations shall support the options in both their hyphen and
9516 * plus-sign forms. These options can also be specified as options to sh.
9518 * Write out all variables and their values: set
9519 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9520 * Turn on the -x and -v options: set -xv
9521 * Unset all positional parameters: set --
9522 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9523 * Set the positional parameters to the expansion of x, even if x expands
9524 * with a leading '-' or '+': set -- $x
9526 * So far, we only support "set -- [argument...]" and some of the short names.
9528 static int FAST_FUNC builtin_set(char **argv)
9531 char **pp, **g_argv;
9532 char *arg = *++argv;
9536 for (e = G.top_var; e; e = e->next)
9538 return EXIT_SUCCESS;
9542 if (strcmp(arg, "--") == 0) {
9546 if (arg[0] != '+' && arg[0] != '-')
9548 for (n = 1; arg[n]; ++n) {
9549 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9551 if (arg[n] == 'o' && argv[1])
9554 } while ((arg = *++argv) != NULL);
9555 /* Now argv[0] is 1st argument */
9558 return EXIT_SUCCESS;
9561 /* NB: G.global_argv[0] ($0) is never freed/changed */
9562 g_argv = G.global_argv;
9563 if (G.global_args_malloced) {
9569 G.global_args_malloced = 1;
9570 pp = xzalloc(sizeof(pp[0]) * 2);
9571 pp[0] = g_argv[0]; /* retain $0 */
9574 /* This realloc's G.global_argv */
9575 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9577 G.global_argc = 1 + string_array_len(pp + 1);
9579 return EXIT_SUCCESS;
9581 /* Nothing known, so abort */
9583 bb_error_msg("set: %s: invalid option", arg);
9584 return EXIT_FAILURE;
9588 static int FAST_FUNC builtin_shift(char **argv)
9591 argv = skip_dash_dash(argv);
9593 n = bb_strtou(argv[0], NULL, 10);
9594 if (errno || n < 0) {
9595 /* shared string with ash.c */
9596 bb_error_msg("Illegal number: %s", argv[0]);
9598 * ash aborts in this case.
9599 * bash prints error message and set $? to 1.
9600 * Interestingly, for "shift 99999" bash does not
9601 * print error message, but does set $? to 1
9602 * (and does no shifting at all).
9606 if (n >= 0 && n < G.global_argc) {
9607 if (G_global_args_malloced) {
9610 free(G.global_argv[m++]);
9613 memmove(&G.global_argv[1], &G.global_argv[n+1],
9614 G.global_argc * sizeof(G.global_argv[0]));
9615 return EXIT_SUCCESS;
9617 return EXIT_FAILURE;
9620 static int FAST_FUNC builtin_source(char **argv)
9622 char *arg_path, *filename;
9625 char *args_need_save;
9626 #if ENABLE_HUSH_FUNCTIONS
9630 argv = skip_dash_dash(argv);
9633 /* bash says: "bash: .: filename argument required" */
9634 return 2; /* bash compat */
9637 if (!strchr(filename, '/')) {
9638 arg_path = find_in_path(filename);
9640 filename = arg_path;
9642 input = remember_FILE(fopen_or_warn(filename, "r"));
9645 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9646 /* POSIX: non-interactive shell should abort here,
9647 * not merely fail. So far no one complained :)
9649 return EXIT_FAILURE;
9652 #if ENABLE_HUSH_FUNCTIONS
9653 sv_flg = G_flag_return_in_progress;
9654 /* "we are inside sourced file, ok to use return" */
9655 G_flag_return_in_progress = -1;
9657 args_need_save = argv[1]; /* used as a boolean variable */
9659 save_and_replace_G_args(&sv, argv);
9661 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9662 G.last_exitcode = 0;
9663 parse_and_run_file(input);
9664 fclose_and_forget(input);
9666 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9667 restore_G_args(&sv, argv);
9668 #if ENABLE_HUSH_FUNCTIONS
9669 G_flag_return_in_progress = sv_flg;
9672 return G.last_exitcode;
9675 #if ENABLE_HUSH_TRAP
9676 static int FAST_FUNC builtin_trap(char **argv)
9682 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9687 /* No args: print all trapped */
9688 for (i = 0; i < NSIG; ++i) {
9691 print_escaped(G_traps[i]);
9692 /* note: bash adds "SIG", but only if invoked
9693 * as "bash". If called as "sh", or if set -o posix,
9694 * then it prints short signal names.
9695 * We are printing short names: */
9696 printf(" %s\n", get_signame(i));
9699 /*fflush_all(); - done after each builtin anyway */
9700 return EXIT_SUCCESS;
9704 /* If first arg is a number: reset all specified signals */
9705 sig = bb_strtou(*argv, NULL, 10);
9711 sighandler_t handler;
9713 sig = get_signum(*argv++);
9714 if (sig < 0 || sig >= NSIG) {
9716 /* Mimic bash message exactly */
9717 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9722 G_traps[sig] = xstrdup(new_cmd);
9724 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9725 get_signame(sig), sig, G_traps[sig]);
9727 /* There is no signal for 0 (EXIT) */
9732 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9734 /* We are removing trap handler */
9735 handler = pick_sighandler(sig);
9736 install_sighandler(sig, handler);
9741 if (!argv[1]) { /* no second arg */
9742 bb_error_msg("trap: invalid arguments");
9743 return EXIT_FAILURE;
9746 /* First arg is "-": reset all specified to default */
9747 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9748 /* Everything else: set arg as signal handler
9749 * (includes "" case, which ignores signal) */
9750 if (argv[0][0] == '-') {
9751 if (argv[0][1] == '\0') { /* "-" */
9752 /* new_cmd remains NULL: "reset these sigs" */
9755 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9758 /* else: "-something", no special meaning */
9763 goto process_sig_list;
9768 static struct pipe *parse_jobspec(const char *str)
9773 if (sscanf(str, "%%%u", &jobnum) != 1) {
9775 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9777 bb_error_msg("bad argument '%s'", str);
9780 /* It is "%%", "%+" or "%" - current job */
9781 jobnum = G.last_jobid;
9783 bb_error_msg("no current job");
9787 for (pi = G.job_list; pi; pi = pi->next) {
9788 if (pi->jobid == jobnum) {
9792 bb_error_msg("%u: no such job", jobnum);
9796 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9799 const char *status_string;
9801 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9802 for (job = G.job_list; job; job = job->next) {
9803 if (job->alive_cmds == job->stopped_cmds)
9804 status_string = "Stopped";
9806 status_string = "Running";
9808 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9811 clean_up_last_dead_job();
9813 return EXIT_SUCCESS;
9816 /* built-in 'fg' and 'bg' handler */
9817 static int FAST_FUNC builtin_fg_bg(char **argv)
9822 if (!G_interactive_fd)
9823 return EXIT_FAILURE;
9825 /* If they gave us no args, assume they want the last backgrounded task */
9827 for (pi = G.job_list; pi; pi = pi->next) {
9828 if (pi->jobid == G.last_jobid) {
9832 bb_error_msg("%s: no current job", argv[0]);
9833 return EXIT_FAILURE;
9836 pi = parse_jobspec(argv[1]);
9838 return EXIT_FAILURE;
9840 /* TODO: bash prints a string representation
9841 * of job being foregrounded (like "sleep 1 | cat") */
9842 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9843 /* Put the job into the foreground. */
9844 tcsetpgrp(G_interactive_fd, pi->pgrp);
9847 /* Restart the processes in the job */
9848 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9849 for (i = 0; i < pi->num_cmds; i++) {
9850 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9852 pi->stopped_cmds = 0;
9854 i = kill(- pi->pgrp, SIGCONT);
9856 if (errno == ESRCH) {
9857 delete_finished_job(pi);
9858 return EXIT_SUCCESS;
9860 bb_perror_msg("kill (SIGCONT)");
9863 if (argv[0][0] == 'f') {
9864 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9865 return checkjobs_and_fg_shell(pi);
9867 return EXIT_SUCCESS;
9871 #if ENABLE_HUSH_KILL
9872 static int FAST_FUNC builtin_kill(char **argv)
9876 # if ENABLE_HUSH_JOB
9877 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9885 if (argv[i][0] != '%')
9888 * "kill %N" - job kill
9889 * Converting to pgrp / pid kill
9891 pi = parse_jobspec(argv[i]);
9893 /* Eat bad jobspec */
9897 argv[j - 1] = argv[j];
9904 * In jobs started under job control, we signal
9905 * entire process group by kill -PGRP_ID.
9906 * This happens, f.e., in interactive shell.
9908 * Otherwise, we signal each child via
9909 * kill PID1 PID2 PID3.
9911 * sh -c 'sleep 1|sleep 1 & kill %1'
9912 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9913 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9915 n = G_interactive_fd ? 1 : pi->num_cmds;
9916 dst = alloca(n * sizeof(int)*4);
9918 if (G_interactive_fd)
9919 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9920 else for (j = 0; j < n; j++) {
9921 struct command *cmd = &pi->cmds[j];
9922 /* Skip exited members of the job */
9926 * kill_main has matching code to expect
9927 * leading space. Needed to not confuse
9928 * negative pids with "kill -SIGNAL_NO" syntax
9930 dst += sprintf(dst, " %u", (int)cmd->pid);
9933 } while (argv[++i]);
9937 if (argv[1] || ret == 0) {
9938 ret = run_applet_main(argv, kill_main);
9940 /* else: ret = 1, "kill %bad_jobspec" case */
9945 #if ENABLE_HUSH_WAIT
9946 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9947 #if !ENABLE_HUSH_JOB
9948 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9950 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9957 if (!sigisemptyset(&G.pending_set))
9960 /* waitpid is not interruptible by SA_RESTARTed
9961 * signals which we use. Thus, this ugly dance:
9964 /* Make sure possible SIGCHLD is stored in kernel's
9965 * pending signal mask before we call waitpid.
9966 * Or else we may race with SIGCHLD, lose it,
9967 * and get stuck in sigsuspend...
9969 sigfillset(&oldset); /* block all signals, remember old set */
9970 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9972 if (!sigisemptyset(&G.pending_set)) {
9973 /* Crap! we raced with some signal! */
9977 /*errno = 0; - checkjobs does this */
9978 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9979 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9980 debug_printf_exec("checkjobs:%d\n", ret);
9983 int rcode = job_exited_or_stopped(waitfor_pipe);
9984 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9987 sigprocmask(SIG_SETMASK, &oldset, NULL);
9992 /* if ECHILD, there are no children (ret is -1 or 0) */
9993 /* if ret == 0, no children changed state */
9994 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9995 if (errno == ECHILD || ret) {
9997 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9999 sigprocmask(SIG_SETMASK, &oldset, NULL);
10002 /* Wait for SIGCHLD or any other signal */
10003 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10004 /* Note: sigsuspend invokes signal handler */
10005 sigsuspend(&oldset);
10007 sigprocmask(SIG_SETMASK, &oldset, NULL);
10009 /* So, did we get a signal? */
10010 sig = check_and_run_traps();
10011 if (sig /*&& sig != SIGCHLD - always true */) {
10015 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10020 static int FAST_FUNC builtin_wait(char **argv)
10025 argv = skip_dash_dash(argv);
10026 if (argv[0] == NULL) {
10027 /* Don't care about wait results */
10028 /* Note 1: must wait until there are no more children */
10029 /* Note 2: must be interruptible */
10031 * $ sleep 3 & sleep 6 & wait
10032 * [1] 30934 sleep 3
10033 * [2] 30935 sleep 6
10036 * $ sleep 3 & sleep 6 & wait
10037 * [1] 30936 sleep 3
10038 * [2] 30937 sleep 6
10040 * ^C <-- after ~4 sec from keyboard
10043 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10047 pid_t pid = bb_strtou(*argv, NULL, 10);
10048 if (errno || pid <= 0) {
10049 #if ENABLE_HUSH_JOB
10050 if (argv[0][0] == '%') {
10051 struct pipe *wait_pipe;
10052 ret = 127; /* bash compat for bad jobspecs */
10053 wait_pipe = parse_jobspec(*argv);
10055 ret = job_exited_or_stopped(wait_pipe);
10057 ret = wait_for_child_or_signal(wait_pipe, 0);
10059 /* waiting on "last dead job" removes it */
10060 clean_up_last_dead_job();
10063 /* else: parse_jobspec() already emitted error msg */
10067 /* mimic bash message */
10068 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10069 ret = EXIT_FAILURE;
10070 continue; /* bash checks all argv[] */
10073 /* Do we have such child? */
10074 ret = waitpid(pid, &status, WNOHANG);
10078 if (errno == ECHILD) {
10079 if (pid == G.last_bg_pid) {
10080 /* "wait $!" but last bg task has already exited. Try:
10081 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10082 * In bash it prints exitcode 0, then 3.
10083 * In dash, it is 127.
10085 ret = G.last_bg_pid_exitcode;
10087 /* Example: "wait 1". mimic bash message */
10088 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10092 bb_perror_msg("wait %s", *argv);
10094 continue; /* bash checks all argv[] */
10097 /* Yes, and it still runs */
10098 ret = wait_for_child_or_signal(NULL, pid);
10100 /* Yes, and it just exited */
10101 process_wait_result(NULL, pid, status);
10102 ret = WEXITSTATUS(status);
10103 if (WIFSIGNALED(status))
10104 ret = 128 + WTERMSIG(status);
10112 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10113 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10116 def = bb_strtou(argv[1], NULL, 10);
10117 if (errno || def < def_min || argv[2]) {
10118 bb_error_msg("%s: bad arguments", argv[0]);
10126 #if ENABLE_HUSH_LOOPS
10127 static int FAST_FUNC builtin_break(char **argv)
10130 if (G.depth_of_loop == 0) {
10131 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10132 /* if we came from builtin_continue(), need to undo "= 1" */
10133 G.flag_break_continue = 0;
10134 return EXIT_SUCCESS; /* bash compat */
10136 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10138 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10139 if (depth == UINT_MAX)
10140 G.flag_break_continue = BC_BREAK;
10141 if (G.depth_of_loop < depth)
10142 G.depth_break_continue = G.depth_of_loop;
10144 return EXIT_SUCCESS;
10147 static int FAST_FUNC builtin_continue(char **argv)
10149 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10150 return builtin_break(argv);
10154 #if ENABLE_HUSH_FUNCTIONS
10155 static int FAST_FUNC builtin_return(char **argv)
10159 if (G_flag_return_in_progress != -1) {
10160 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10161 return EXIT_FAILURE; /* bash compat */
10164 G_flag_return_in_progress = 1;
10167 * out of range: wraps around at 256, does not error out
10168 * non-numeric param:
10169 * f() { false; return qwe; }; f; echo $?
10170 * bash: return: qwe: numeric argument required <== we do this
10171 * 255 <== we also do this
10173 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10178 #if ENABLE_HUSH_MEMLEAK
10179 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10184 # ifdef M_TRIM_THRESHOLD
10185 /* Optional. Reduces probability of false positives */
10188 /* Crude attempt to find where "free memory" starts,
10189 * sans fragmentation. */
10191 l = (unsigned long)p;
10194 if (l < (unsigned long)p) l = (unsigned long)p;
10200 struct mallinfo mi = mallinfo();
10201 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10202 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10206 if (!G.memleak_value)
10207 G.memleak_value = l;
10209 l -= G.memleak_value;
10216 /* Exitcode is "how many kilobytes we leaked since 1st call" */