1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc, getopts, times:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * getopts: getopt() for shells
62 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
63 * fc -l[nr] [BEG] [END]: list range of commands in history
64 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
65 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
68 * redirection of stdout+stderr: &> and >&
69 * reserved words: function select
70 * advanced test: [[ ]]
71 * process substitution: <(list) and >(list)
74 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
75 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
76 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
78 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
79 * This is exactly equivalent to let "EXPR".
80 * $[EXPR]: synonym for $((EXPR))
81 * indirect expansion: ${!VAR}
82 * substring op on @: ${@:n:m}
85 * Some builtins mandated by standards:
86 * newgrp [GRP]: not a builtin in bash but a suid binary
87 * which spawns a new shell with new group ID
88 * In bash, export builtin is special, its arguments are assignments
89 * and therefore expansion of them should be "one-word" expansion:
90 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
92 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
93 * ls: cannot access i=a: No such file or directory
94 * ls: cannot access b: No such file or directory
95 * Note1: same applies to local builtin.
96 * Note2: bash 3.2.33(1) does this only if export word itself
98 * $ export i=`echo 'aaa bbb'`; echo "$i"
100 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
104 //config: bool "hush (64 kb)"
107 //config: hush is a small shell. It handles the normal flow control
108 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
109 //config: case/esac. Redirections, here documents, $((arithmetic))
110 //config: and functions are supported.
112 //config: It will compile and work on no-mmu systems.
114 //config: It does not handle select, aliases, tilde expansion,
115 //config: &>file and >&file redirection of stdout+stderr.
117 //config:config HUSH_BASH_COMPAT
118 //config: bool "bash-compatible extensions"
120 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
122 //config:config HUSH_BRACE_EXPANSION
123 //config: bool "Brace expansion"
125 //config: depends on HUSH_BASH_COMPAT
127 //config: Enable {abc,def} extension.
129 //config:config HUSH_INTERACTIVE
130 //config: bool "Interactive mode"
132 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
134 //config: Enable interactive mode (prompt and command editing).
135 //config: Without this, hush simply reads and executes commands
136 //config: from stdin just like a shell script from a file.
137 //config: No prompt, no PS1/PS2 magic shell variables.
139 //config:config HUSH_SAVEHISTORY
140 //config: bool "Save command history to .hush_history"
142 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
144 //config:config HUSH_JOB
145 //config: bool "Job control"
147 //config: depends on HUSH_INTERACTIVE
149 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
150 //config: command (not entire shell), fg/bg builtins work. Without this option,
151 //config: "cmd &" still works by simply spawning a process and immediately
152 //config: prompting for next command (or executing next command in a script),
153 //config: but no separate process group is formed.
155 //config:config HUSH_TICK
156 //config: bool "Support process substitution"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable `command` and $(command).
162 //config:config HUSH_IF
163 //config: bool "Support if/then/elif/else/fi"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config:config HUSH_LOOPS
168 //config: bool "Support for, while and until loops"
170 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
172 //config:config HUSH_CASE
173 //config: bool "Support case ... esac statement"
175 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
177 //config: Enable case ... esac statement. +400 bytes.
179 //config:config HUSH_FUNCTIONS
180 //config: bool "Support funcname() { commands; } syntax"
182 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
184 //config: Enable support for shell functions. +800 bytes.
186 //config:config HUSH_LOCAL
187 //config: bool "local builtin"
189 //config: depends on HUSH_FUNCTIONS
191 //config: Enable support for local variables in functions.
193 //config:config HUSH_RANDOM_SUPPORT
194 //config: bool "Pseudorandom generator and $RANDOM variable"
196 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
198 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
199 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
201 //config:config HUSH_MODE_X
202 //config: bool "Support 'hush -x' option and 'set -x' command"
204 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
206 //config: This instructs hush to print commands before execution.
207 //config: Adds ~300 bytes.
209 //config:config HUSH_ECHO
210 //config: bool "echo builtin"
212 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
214 //config:config HUSH_PRINTF
215 //config: bool "printf builtin"
217 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
219 //config:config HUSH_TEST
220 //config: bool "test builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config:config HUSH_HELP
225 //config: bool "help builtin"
227 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
229 //config:config HUSH_EXPORT
230 //config: bool "export builtin"
232 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
234 //config:config HUSH_EXPORT_N
235 //config: bool "Support 'export -n' option"
237 //config: depends on HUSH_EXPORT
239 //config: export -n unexports variables. It is a bash extension.
241 //config:config HUSH_READONLY
242 //config: bool "readonly builtin"
244 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
246 //config: Enable support for read-only variables.
248 //config:config HUSH_KILL
249 //config: bool "kill builtin (supports kill %jobspec)"
251 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
253 //config:config HUSH_WAIT
254 //config: bool "wait builtin"
256 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
258 //config:config HUSH_TRAP
259 //config: bool "trap builtin"
261 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
263 //config:config HUSH_TYPE
264 //config: bool "type builtin"
266 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
268 //config:config HUSH_READ
269 //config: bool "read builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config:config HUSH_SET
274 //config: bool "set builtin"
276 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
278 //config:config HUSH_UNSET
279 //config: bool "unset builtin"
281 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
283 //config:config HUSH_ULIMIT
284 //config: bool "ulimit builtin"
286 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
288 //config:config HUSH_UMASK
289 //config: bool "umask builtin"
291 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
293 //config:config HUSH_MEMLEAK
294 //config: bool "memleak builtin (debugging)"
296 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
298 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
299 // APPLET_ODDNAME:name main location suid_type help
300 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
301 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
303 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
304 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
305 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
306 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
308 /* -i (interactive) and -s (read stdin) are also accepted,
309 * but currently do nothing, therefore aren't shown in help.
310 * NOMMU-specific options are not meant to be used by users,
311 * therefore we don't show them either.
313 //usage:#define hush_trivial_usage
314 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
315 //usage:#define hush_full_usage "\n\n"
316 //usage: "Unix shell interpreter"
318 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
319 || defined(__APPLE__) \
321 # include <malloc.h> /* for malloc_trim */
324 /* #include <dmalloc.h> */
326 # include <fnmatch.h>
328 #include <sys/utsname.h> /* for setting $HOSTNAME */
330 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
332 #include "shell_common.h"
335 #if ENABLE_HUSH_RANDOM_SUPPORT
338 # define CLEAR_RANDOM_T(rnd) ((void)0)
340 #ifndef F_DUPFD_CLOEXEC
341 # define F_DUPFD_CLOEXEC F_DUPFD
344 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
348 /* So far, all bash compat is controlled by one config option */
349 /* Separate defines document which part of code implements what */
350 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
351 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
352 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
353 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
354 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
358 #define LEAK_HUNTING 0
359 #define BUILD_AS_NOMMU 0
360 /* Enable/disable sanity checks. Ok to enable in production,
361 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
362 * Keeping 1 for now even in released versions.
365 /* Slightly bigger (+200 bytes), but faster hush.
366 * So far it only enables a trick with counting SIGCHLDs and forks,
367 * which allows us to do fewer waitpid's.
368 * (we can detect a case where neither forks were done nor SIGCHLDs happened
369 * and therefore waitpid will return the same result as last time)
371 #define ENABLE_HUSH_FAST 0
372 /* TODO: implement simplified code for users which do not need ${var%...} ops
373 * So far ${var%...} ops are always enabled:
375 #define ENABLE_HUSH_DOLLAR_OPS 1
380 # undef USE_FOR_NOMMU
383 # define USE_FOR_NOMMU(...) __VA_ARGS__
384 # define USE_FOR_MMU(...)
387 #include "NUM_APPLETS.h"
389 /* STANDALONE does not make sense, and won't compile */
390 # undef CONFIG_FEATURE_SH_STANDALONE
391 # undef ENABLE_FEATURE_SH_STANDALONE
392 # undef IF_FEATURE_SH_STANDALONE
393 # undef IF_NOT_FEATURE_SH_STANDALONE
394 # define ENABLE_FEATURE_SH_STANDALONE 0
395 # define IF_FEATURE_SH_STANDALONE(...)
396 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
399 #if !ENABLE_HUSH_INTERACTIVE
400 # undef ENABLE_FEATURE_EDITING
401 # define ENABLE_FEATURE_EDITING 0
402 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
403 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
404 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
405 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
408 /* Do we support ANY keywords? */
409 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 # define HAS_KEYWORDS 1
411 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
412 # define IF_HAS_NO_KEYWORDS(...)
414 # define HAS_KEYWORDS 0
415 # define IF_HAS_KEYWORDS(...)
416 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
419 /* If you comment out one of these below, it will be #defined later
420 * to perform debug printfs to stderr: */
421 #define debug_printf(...) do {} while (0)
422 /* Finer-grained debug switches */
423 #define debug_printf_parse(...) do {} while (0)
424 #define debug_print_tree(a, b) do {} while (0)
425 #define debug_printf_exec(...) do {} while (0)
426 #define debug_printf_env(...) do {} while (0)
427 #define debug_printf_jobs(...) do {} while (0)
428 #define debug_printf_expand(...) do {} while (0)
429 #define debug_printf_varexp(...) do {} while (0)
430 #define debug_printf_glob(...) do {} while (0)
431 #define debug_printf_redir(...) do {} while (0)
432 #define debug_printf_list(...) do {} while (0)
433 #define debug_printf_subst(...) do {} while (0)
434 #define debug_printf_clean(...) do {} while (0)
436 #define ERR_PTR ((void*)(long)1)
438 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
440 #define _SPECIAL_VARS_STR "_*@$!?#"
441 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
442 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
443 #if BASH_PATTERN_SUBST
444 /* Support / and // replace ops */
445 /* Note that // is stored as \ in "encoded" string representation */
446 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
447 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
448 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
450 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
451 # define VAR_SUBST_OPS "%#:-=+?"
452 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
455 #define SPECIAL_VAR_SYMBOL 3
459 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
461 /* This supports saving pointers malloced in vfork child,
462 * to be freed in the parent.
465 typedef struct nommu_save_t {
467 struct variable *old_vars;
469 char **argv_from_re_execing;
482 #if ENABLE_HUSH_LOOPS
489 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
494 /* three pseudo-keywords support contrived "case" syntax: */
495 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
496 RES_MATCH , /* "word)" */
497 RES_CASE_BODY, /* "this command is inside CASE" */
504 typedef struct o_string {
506 int length; /* position where data is appended */
509 /* At least some part of the string was inside '' or "",
510 * possibly empty one: word"", wo''rd etc. */
511 smallint has_quoted_part;
512 smallint has_empty_slot;
513 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
516 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
518 /* Protect newly added chars against globbing
519 * by prepending \ to *, ?, [, \ */
520 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
523 MAYBE_ASSIGNMENT = 0,
524 DEFINITELY_ASSIGNMENT = 1,
526 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
529 /* Used for initialization: o_string foo = NULL_O_STRING; */
530 #define NULL_O_STRING { NULL }
532 #ifndef debug_printf_parse
533 static const char *const assignment_flag[] = {
535 "DEFINITELY_ASSIGNMENT",
541 typedef struct in_str {
543 #if ENABLE_HUSH_INTERACTIVE
544 smallint promptmode; /* 0: PS1, 1: PS2 */
551 /* The descrip member of this structure is only used to make
552 * debugging output pretty */
553 static const struct {
555 signed char default_fd;
558 { O_RDONLY, 0, "<" },
559 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
560 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
561 { O_CREAT|O_RDWR, 1, "<>" },
562 { O_RDONLY, 0, "<<" },
563 /* Should not be needed. Bogus default_fd helps in debugging */
564 /* { O_RDONLY, 77, "<<" }, */
567 struct redir_struct {
568 struct redir_struct *next;
569 char *rd_filename; /* filename */
570 int rd_fd; /* fd to redirect */
571 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
573 smallint rd_type; /* (enum redir_type) */
574 /* note: for heredocs, rd_filename contains heredoc delimiter,
575 * and subsequently heredoc itself; and rd_dup is a bitmask:
576 * bit 0: do we need to trim leading tabs?
577 * bit 1: is heredoc quoted (<<'delim' syntax) ?
580 typedef enum redir_type {
582 REDIRECT_OVERWRITE = 1,
585 REDIRECT_HEREDOC = 4,
586 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
589 REDIRFD_SYNTAX_ERR = -2,
590 REDIRFD_TO_FILE = -1,
591 /* otherwise, rd_fd is redirected to rd_dup */
593 HEREDOC_SKIPTABS = 1,
599 pid_t pid; /* 0 if exited */
600 int assignment_cnt; /* how many argv[i] are assignments? */
601 smallint cmd_type; /* CMD_xxx */
603 #define CMD_SUBSHELL 1
605 /* used for "[[ EXPR ]]" */
606 # define CMD_SINGLEWORD_NOGLOB 2
608 #if ENABLE_HUSH_FUNCTIONS
609 # define CMD_FUNCDEF 3
612 smalluint cmd_exitcode;
613 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
616 char *group_as_string;
618 #if ENABLE_HUSH_FUNCTIONS
619 struct function *child_func;
620 /* This field is used to prevent a bug here:
621 * while...do f1() {a;}; f1; f1() {b;}; f1; done
622 * When we execute "f1() {a;}" cmd, we create new function and clear
623 * cmd->group, cmd->group_as_string, cmd->argv[0].
624 * When we execute "f1() {b;}", we notice that f1 exists,
625 * and that its "parent cmd" struct is still "alive",
626 * we put those fields back into cmd->xxx
627 * (struct function has ->parent_cmd ptr to facilitate that).
628 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
629 * Without this trick, loop would execute a;b;b;b;...
630 * instead of correct sequence a;b;a;b;...
631 * When command is freed, it severs the link
632 * (sets ->child_func->parent_cmd to NULL).
635 char **argv; /* command name and arguments */
636 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
637 * and on execution these are substituted with their values.
638 * Substitution can make _several_ words out of one argv[n]!
639 * Example: argv[0]=='.^C*^C.' here: echo .$*.
640 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
642 struct redir_struct *redirects; /* I/O redirections */
644 /* Is there anything in this command at all? */
645 #define IS_NULL_CMD(cmd) \
646 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
650 int num_cmds; /* total number of commands in pipe */
651 int alive_cmds; /* number of commands running (not exited) */
652 int stopped_cmds; /* number of commands alive, but stopped */
654 unsigned jobid; /* job number */
655 pid_t pgrp; /* process group ID for the job */
656 char *cmdtext; /* name of job */
658 struct command *cmds; /* array of commands in pipe */
659 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
660 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
661 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
663 typedef enum pipe_style {
669 /* Is there anything in this pipe at all? */
670 #define IS_NULL_PIPE(pi) \
671 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
673 /* This holds pointers to the various results of parsing */
674 struct parse_context {
675 /* linked list of pipes */
676 struct pipe *list_head;
677 /* last pipe (being constructed right now) */
679 /* last command in pipe (being constructed right now) */
680 struct command *command;
681 /* last redirect in command->redirects list */
682 struct redir_struct *pending_redirect;
688 smallint ctx_inverted; /* "! cmd | cmd" */
690 smallint ctx_dsemicolon; /* ";;" seen */
692 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
694 /* group we are enclosed in:
695 * example: "if pipe1; pipe2; then pipe3; fi"
696 * when we see "if" or "then", we malloc and copy current context,
697 * and make ->stack point to it. then we parse pipeN.
698 * when closing "then" / fi" / whatever is found,
699 * we move list_head into ->stack->command->group,
700 * copy ->stack into current context, and delete ->stack.
701 * (parsing of { list } and ( list ) doesn't use this method)
703 struct parse_context *stack;
707 /* On program start, environ points to initial environment.
708 * putenv adds new pointers into it, unsetenv removes them.
709 * Neither of these (de)allocates the strings.
710 * setenv allocates new strings in malloc space and does putenv,
711 * and thus setenv is unusable (leaky) for shell's purposes */
712 #define setenv(...) setenv_is_leaky_dont_use()
714 struct variable *next;
715 char *varstr; /* points to "name=" portion */
716 #if ENABLE_HUSH_LOCAL
717 unsigned func_nest_level;
719 int max_len; /* if > 0, name is part of initial env; else name is malloced */
720 smallint flg_export; /* putenv should be done on this var */
721 smallint flg_read_only;
729 #if ENABLE_HUSH_FUNCTIONS
731 struct function *next;
733 struct command *parent_cmd;
736 char *body_as_string;
742 /* set -/+o OPT support. (TODO: make it optional)
743 * bash supports the following opts:
754 * interactive-comments on
772 static const char o_opt_strings[] ALIGN1 =
776 #if ENABLE_HUSH_MODE_X
784 #if ENABLE_HUSH_MODE_X
792 struct FILE_list *next;
798 /* "Globals" within this file */
799 /* Sorted roughly by size (smaller offsets == smaller code) */
801 /* interactive_fd != 0 means we are an interactive shell.
802 * If we are, then saved_tty_pgrp can also be != 0, meaning
803 * that controlling tty is available. With saved_tty_pgrp == 0,
804 * job control still works, but terminal signals
805 * (^C, ^Z, ^Y, ^\) won't work at all, and background
806 * process groups can only be created with "cmd &".
807 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
808 * to give tty to the foreground process group,
809 * and will take it back when the group is stopped (^Z)
812 #if ENABLE_HUSH_INTERACTIVE
813 /* 'interactive_fd' is a fd# open to ctty, if we have one
814 * _AND_ if we decided to act interactively */
818 # define G_interactive_fd (G.interactive_fd)
820 # define G_interactive_fd 0
822 #if ENABLE_FEATURE_EDITING
823 line_input_t *line_input_state;
828 #if ENABLE_HUSH_RANDOM_SUPPORT
834 pid_t saved_tty_pgrp;
835 struct pipe *job_list;
836 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
838 # define G_saved_tty_pgrp 0
840 /* How deeply are we in context where "set -e" is ignored */
842 /* "set -e" rules (do we follow them correctly?):
843 * Exit if pipe, list, or compound command exits with a non-zero status.
844 * Shell does not exit if failed command is part of condition in
845 * if/while, part of && or || list except the last command, any command
846 * in a pipe but the last, or if the command's return value is being
847 * inverted with !. If a compound command other than a subshell returns a
848 * non-zero status because a command failed while -e was being ignored, the
849 * shell does not exit. A trap on ERR, if set, is executed before the shell
850 * exits [ERR is a bashism].
852 * If a compound command or function executes in a context where -e is
853 * ignored, none of the commands executed within are affected by the -e
854 * setting. If a compound command or function sets -e while executing in a
855 * context where -e is ignored, that setting does not have any effect until
856 * the compound command or the command containing the function call completes.
859 char o_opt[NUM_OPT_O];
860 #if ENABLE_HUSH_MODE_X
861 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
865 smallint flag_SIGINT;
866 #if ENABLE_HUSH_LOOPS
867 smallint flag_break_continue;
869 #if ENABLE_HUSH_FUNCTIONS
870 /* 0: outside of a function (or sourced file)
871 * -1: inside of a function, ok to use return builtin
872 * 1: return is invoked, skip all till end of func
874 smallint flag_return_in_progress;
875 # define G_flag_return_in_progress (G.flag_return_in_progress)
877 # define G_flag_return_in_progress 0
879 smallint exiting; /* used to prevent EXIT trap recursion */
880 /* These four support $?, $#, and $1 */
881 smalluint last_exitcode;
882 smalluint last_bg_pid_exitcode;
884 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
885 smalluint global_args_malloced;
886 # define G_global_args_malloced (G.global_args_malloced)
888 # define G_global_args_malloced 0
890 /* how many non-NULL argv's we have. NB: $# + 1 */
894 char *argv0_for_re_execing;
896 #if ENABLE_HUSH_LOOPS
897 unsigned depth_break_continue;
898 unsigned depth_of_loop;
902 struct variable *top_var;
903 char **expanded_assignments;
904 #if ENABLE_HUSH_FUNCTIONS
905 struct function *top_func;
906 # if ENABLE_HUSH_LOCAL
907 struct variable **shadowed_vars_pp;
908 unsigned func_nest_level;
911 /* Signal and trap handling */
913 unsigned count_SIGCHLD;
914 unsigned handled_SIGCHLD;
915 smallint we_have_children;
917 struct FILE_list *FILE_list;
918 /* Which signals have non-DFL handler (even with no traps set)?
919 * Set at the start to:
920 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
921 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
922 * The rest is cleared right before execv syscalls.
923 * Other than these two times, never modified.
925 unsigned special_sig_mask;
927 unsigned fatal_sig_mask;
928 # define G_fatal_sig_mask (G.fatal_sig_mask)
930 # define G_fatal_sig_mask 0
933 char **traps; /* char *traps[NSIG] */
934 # define G_traps G.traps
936 # define G_traps ((char**)NULL)
938 sigset_t pending_set;
939 #if ENABLE_HUSH_MEMLEAK
940 unsigned long memleak_value;
946 #if ENABLE_FEATURE_EDITING
947 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
950 #define G (*ptr_to_globals)
951 /* Not #defining name to G.name - this quickly gets unwieldy
952 * (too many defines). Also, I actually prefer to see when a variable
953 * is global, thus "G." prefix is a useful hint */
954 #define INIT_G() do { \
955 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
956 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
957 sigfillset(&G.sa.sa_mask); \
958 G.sa.sa_flags = SA_RESTART; \
962 /* Function prototypes for builtins */
963 static int builtin_cd(char **argv) FAST_FUNC;
965 static int builtin_echo(char **argv) FAST_FUNC;
967 static int builtin_eval(char **argv) FAST_FUNC;
968 static int builtin_exec(char **argv) FAST_FUNC;
969 static int builtin_exit(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_EXPORT
971 static int builtin_export(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_READONLY
974 static int builtin_readonly(char **argv) FAST_FUNC;
977 static int builtin_fg_bg(char **argv) FAST_FUNC;
978 static int builtin_jobs(char **argv) FAST_FUNC;
981 static int builtin_help(char **argv) FAST_FUNC;
983 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
984 static int builtin_history(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_LOCAL
987 static int builtin_local(char **argv) FAST_FUNC;
989 #if ENABLE_HUSH_MEMLEAK
990 static int builtin_memleak(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_PRINTF
993 static int builtin_printf(char **argv) FAST_FUNC;
995 static int builtin_pwd(char **argv) FAST_FUNC;
997 static int builtin_read(char **argv) FAST_FUNC;
1000 static int builtin_set(char **argv) FAST_FUNC;
1002 static int builtin_shift(char **argv) FAST_FUNC;
1003 static int builtin_source(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_TEST || BASH_TEST2
1005 static int builtin_test(char **argv) FAST_FUNC;
1007 #if ENABLE_HUSH_TRAP
1008 static int builtin_trap(char **argv) FAST_FUNC;
1010 #if ENABLE_HUSH_TYPE
1011 static int builtin_type(char **argv) FAST_FUNC;
1013 static int builtin_true(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_UMASK
1015 static int builtin_umask(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_UNSET
1018 static int builtin_unset(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_KILL
1021 static int builtin_kill(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_WAIT
1024 static int builtin_wait(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_LOOPS
1027 static int builtin_break(char **argv) FAST_FUNC;
1028 static int builtin_continue(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_FUNCTIONS
1031 static int builtin_return(char **argv) FAST_FUNC;
1034 /* Table of built-in functions. They can be forked or not, depending on
1035 * context: within pipes, they fork. As simple commands, they do not.
1036 * When used in non-forking context, they can change global variables
1037 * in the parent shell process. If forked, of course they cannot.
1038 * For example, 'unset foo | whatever' will parse and run, but foo will
1039 * still be set at the end. */
1040 struct built_in_command {
1042 int (*b_function)(char **argv) FAST_FUNC;
1043 #if ENABLE_HUSH_HELP
1044 const char *b_descr;
1045 # define BLTIN(cmd, func, help) { cmd, func, help }
1047 # define BLTIN(cmd, func, help) { cmd, func }
1051 static const struct built_in_command bltins1[] = {
1052 BLTIN("." , builtin_source , "Run commands in file"),
1053 BLTIN(":" , builtin_true , NULL),
1055 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1057 #if ENABLE_HUSH_LOOPS
1058 BLTIN("break" , builtin_break , "Exit loop"),
1060 BLTIN("cd" , builtin_cd , "Change directory"),
1061 #if ENABLE_HUSH_LOOPS
1062 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1064 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1065 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1066 BLTIN("exit" , builtin_exit , NULL),
1067 #if ENABLE_HUSH_EXPORT
1068 BLTIN("export" , builtin_export , "Set environment variables"),
1071 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1073 #if ENABLE_HUSH_HELP
1074 BLTIN("help" , builtin_help , NULL),
1076 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1077 BLTIN("history" , builtin_history , "Show history"),
1080 BLTIN("jobs" , builtin_jobs , "List jobs"),
1082 #if ENABLE_HUSH_KILL
1083 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1085 #if ENABLE_HUSH_LOCAL
1086 BLTIN("local" , builtin_local , "Set local variables"),
1088 #if ENABLE_HUSH_MEMLEAK
1089 BLTIN("memleak" , builtin_memleak , NULL),
1091 #if ENABLE_HUSH_READ
1092 BLTIN("read" , builtin_read , "Input into variable"),
1094 #if ENABLE_HUSH_READONLY
1095 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1097 #if ENABLE_HUSH_FUNCTIONS
1098 BLTIN("return" , builtin_return , "Return from function"),
1101 BLTIN("set" , builtin_set , "Set positional parameters"),
1103 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1105 BLTIN("source" , builtin_source , NULL),
1107 #if ENABLE_HUSH_TRAP
1108 BLTIN("trap" , builtin_trap , "Trap signals"),
1110 BLTIN("true" , builtin_true , NULL),
1111 #if ENABLE_HUSH_TYPE
1112 BLTIN("type" , builtin_type , "Show command type"),
1114 #if ENABLE_HUSH_ULIMIT
1115 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1117 #if ENABLE_HUSH_UMASK
1118 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1120 #if ENABLE_HUSH_UNSET
1121 BLTIN("unset" , builtin_unset , "Unset variables"),
1123 #if ENABLE_HUSH_WAIT
1124 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1127 /* These builtins won't be used if we are on NOMMU and need to re-exec
1128 * (it's cheaper to run an external program in this case):
1130 static const struct built_in_command bltins2[] = {
1131 #if ENABLE_HUSH_TEST
1132 BLTIN("[" , builtin_test , NULL),
1135 BLTIN("[[" , builtin_test , NULL),
1137 #if ENABLE_HUSH_ECHO
1138 BLTIN("echo" , builtin_echo , NULL),
1140 #if ENABLE_HUSH_PRINTF
1141 BLTIN("printf" , builtin_printf , NULL),
1143 BLTIN("pwd" , builtin_pwd , NULL),
1144 #if ENABLE_HUSH_TEST
1145 BLTIN("test" , builtin_test , NULL),
1153 /* prevent disasters with G.debug_indent < 0 */
1154 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1155 # define debug_enter() (G.debug_indent++)
1156 # define debug_leave() (G.debug_indent--)
1158 # define indent() ((void)0)
1159 # define debug_enter() ((void)0)
1160 # define debug_leave() ((void)0)
1163 #ifndef debug_printf
1164 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_parse
1168 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1171 #ifndef debug_printf_exec
1172 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1175 #ifndef debug_printf_env
1176 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1179 #ifndef debug_printf_jobs
1180 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1181 # define DEBUG_JOBS 1
1183 # define DEBUG_JOBS 0
1186 #ifndef debug_printf_expand
1187 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1188 # define DEBUG_EXPAND 1
1190 # define DEBUG_EXPAND 0
1193 #ifndef debug_printf_varexp
1194 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_glob
1198 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1199 # define DEBUG_GLOB 1
1201 # define DEBUG_GLOB 0
1204 #ifndef debug_printf_redir
1205 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1208 #ifndef debug_printf_list
1209 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1212 #ifndef debug_printf_subst
1213 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1216 #ifndef debug_printf_clean
1217 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1218 # define DEBUG_CLEAN 1
1220 # define DEBUG_CLEAN 0
1224 static void debug_print_strings(const char *prefix, char **vv)
1227 fdprintf(2, "%s:\n", prefix);
1229 fdprintf(2, " '%s'\n", *vv++);
1232 # define debug_print_strings(prefix, vv) ((void)0)
1236 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1239 static void *xxmalloc(int lineno, size_t size)
1241 void *ptr = xmalloc((size + 0xff) & ~0xff);
1242 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1245 static void *xxrealloc(int lineno, void *ptr, size_t size)
1247 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1248 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1251 static char *xxstrdup(int lineno, const char *str)
1253 char *ptr = xstrdup(str);
1254 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1257 static void xxfree(void *ptr)
1259 fdprintf(2, "free %p\n", ptr);
1262 # define xmalloc(s) xxmalloc(__LINE__, s)
1263 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1264 # define xstrdup(s) xxstrdup(__LINE__, s)
1265 # define free(p) xxfree(p)
1269 /* Syntax and runtime errors. They always abort scripts.
1270 * In interactive use they usually discard unparsed and/or unexecuted commands
1271 * and return to the prompt.
1272 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1275 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(unsigned lineno, const char *fmt, ...)
1288 bb_error_msg("hush.c:%u", lineno);
1291 bb_verror_msg(fmt, p, NULL);
1293 if (!G_interactive_fd)
1297 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1300 bb_error_msg("syntax error: %s", msg);
1302 bb_error_msg("syntax error");
1305 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1307 bb_error_msg("syntax error at '%s'", msg);
1310 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1312 bb_error_msg("syntax error: unterminated %s", s);
1315 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1317 char msg[2] = { ch, '\0' };
1318 syntax_error_unterm_str(lineno, msg);
1321 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1327 bb_error_msg("hush.c:%u", lineno);
1329 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1333 # undef die_if_script
1334 # undef syntax_error
1335 # undef syntax_error_at
1336 # undef syntax_error_unterm_ch
1337 # undef syntax_error_unterm_str
1338 # undef syntax_error_unexpected_ch
1340 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1341 # define syntax_error(msg) syntax_error(__LINE__, msg)
1342 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1343 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1344 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1345 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1349 #if ENABLE_HUSH_INTERACTIVE
1350 static void cmdedit_update_prompt(void);
1352 # define cmdedit_update_prompt() ((void)0)
1356 /* Utility functions
1358 /* Replace each \x with x in place, return ptr past NUL. */
1359 static char *unbackslash(char *src)
1361 char *dst = src = strchrnul(src, '\\');
1365 if ((*dst++ = *src++) == '\0')
1371 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1392 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1393 v[count1 + count2] = NULL;
1396 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1400 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1402 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1403 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1406 #define add_strings_to_strings(strings, add, need_to_dup) \
1407 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1410 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1411 static char **add_string_to_strings(char **strings, char *add)
1416 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1419 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1421 char **ptr = add_string_to_strings(strings, add);
1422 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1425 #define add_string_to_strings(strings, add) \
1426 xx_add_string_to_strings(__LINE__, strings, add)
1429 static void free_strings(char **strings)
1443 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1447 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1457 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd)
1461 newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1);
1467 /* fd was not open? */
1477 /* Manipulating the list of open FILEs */
1478 static FILE *remember_FILE(FILE *fp)
1481 struct FILE_list *n = xmalloc(sizeof(*n));
1482 n->next = G.FILE_list;
1486 close_on_exec_on(n->fd);
1490 static void fclose_and_forget(FILE *fp)
1492 struct FILE_list **pp = &G.FILE_list;
1494 struct FILE_list *cur = *pp;
1495 if (cur->fp == fp) {
1504 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1506 struct FILE_list *fl = G.FILE_list;
1509 /* We use it only on script files, they are all CLOEXEC */
1510 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd);
1511 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1518 static void restore_redirected_FILEs(void)
1520 struct FILE_list *fl = G.FILE_list;
1522 int should_be = fileno(fl->fp);
1523 if (fl->fd != should_be) {
1524 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1525 xmove_fd(fl->fd, should_be);
1531 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1532 static void close_all_FILE_list(void)
1534 struct FILE_list *fl = G.FILE_list;
1536 /* fclose would also free FILE object.
1537 * It is disastrous if we share memory with a vforked parent.
1538 * I'm not sure we never come here after vfork.
1539 * Therefore just close fd, nothing more.
1541 /*fclose(fl->fp); - unsafe */
1549 /* Helpers for setting new $n and restoring them back
1551 typedef struct save_arg_t {
1555 IF_HUSH_SET(smallint sv_g_malloced;)
1558 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1560 sv->sv_argv0 = argv[0];
1561 sv->sv_g_argv = G.global_argv;
1562 sv->sv_g_argc = G.global_argc;
1563 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1565 argv[0] = G.global_argv[0]; /* retain $0 */
1566 G.global_argv = argv;
1567 IF_HUSH_SET(G.global_args_malloced = 0;)
1569 G.global_argc = 1 + string_array_len(argv + 1);
1572 static void restore_G_args(save_arg_t *sv, char **argv)
1575 if (G.global_args_malloced) {
1576 /* someone ran "set -- arg1 arg2 ...", undo */
1577 char **pp = G.global_argv;
1578 while (*++pp) /* note: does not free $0 */
1580 free(G.global_argv);
1583 argv[0] = sv->sv_argv0;
1584 G.global_argv = sv->sv_g_argv;
1585 G.global_argc = sv->sv_g_argc;
1586 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1590 /* Basic theory of signal handling in shell
1591 * ========================================
1592 * This does not describe what hush does, rather, it is current understanding
1593 * what it _should_ do. If it doesn't, it's a bug.
1594 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1596 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1597 * is finished or backgrounded. It is the same in interactive and
1598 * non-interactive shells, and is the same regardless of whether
1599 * a user trap handler is installed or a shell special one is in effect.
1600 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1601 * backgrounds (i.e. stops) or kills all members of currently running
1604 * Wait builtin is interruptible by signals for which user trap is set
1605 * or by SIGINT in interactive shell.
1607 * Trap handlers will execute even within trap handlers. (right?)
1609 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1610 * except for handlers set to '' (empty string).
1612 * If job control is off, backgrounded commands ("cmd &")
1613 * have SIGINT, SIGQUIT set to SIG_IGN.
1615 * Commands which are run in command substitution ("`cmd`")
1616 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1618 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1619 * by the shell from its parent.
1621 * Signals which differ from SIG_DFL action
1622 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1625 * SIGTERM (interactive): ignore
1626 * SIGHUP (interactive):
1627 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1628 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1629 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1630 * that all pipe members are stopped. Try this in bash:
1631 * while :; do :; done - ^Z does not background it
1632 * (while :; do :; done) - ^Z backgrounds it
1633 * SIGINT (interactive): wait for last pipe, ignore the rest
1634 * of the command line, show prompt. NB: ^C does not send SIGINT
1635 * to interactive shell while shell is waiting for a pipe,
1636 * since shell is bg'ed (is not in foreground process group).
1637 * Example 1: this waits 5 sec, but does not execute ls:
1638 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1639 * Example 2: this does not wait and does not execute ls:
1640 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1641 * Example 3: this does not wait 5 sec, but executes ls:
1642 * "sleep 5; ls -l" + press ^C
1643 * Example 4: this does not wait and does not execute ls:
1644 * "sleep 5 & wait; ls -l" + press ^C
1646 * (What happens to signals which are IGN on shell start?)
1647 * (What happens with signal mask on shell start?)
1649 * Old implementation
1650 * ==================
1651 * We use in-kernel pending signal mask to determine which signals were sent.
1652 * We block all signals which we don't want to take action immediately,
1653 * i.e. we block all signals which need to have special handling as described
1654 * above, and all signals which have traps set.
1655 * After each pipe execution, we extract any pending signals via sigtimedwait()
1658 * unsigned special_sig_mask: a mask of such "special" signals
1659 * sigset_t blocked_set: current blocked signal set
1662 * clear bit in blocked_set unless it is also in special_sig_mask
1663 * "trap 'cmd' SIGxxx":
1664 * set bit in blocked_set (even if 'cmd' is '')
1665 * after [v]fork, if we plan to be a shell:
1666 * unblock signals with special interactive handling
1667 * (child shell is not interactive),
1668 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1669 * after [v]fork, if we plan to exec:
1670 * POSIX says fork clears pending signal mask in child - no need to clear it.
1671 * Restore blocked signal set to one inherited by shell just prior to exec.
1673 * Note: as a result, we do not use signal handlers much. The only uses
1674 * are to count SIGCHLDs
1675 * and to restore tty pgrp on signal-induced exit.
1678 * Standard says "When a subshell is entered, traps that are not being ignored
1679 * are set to the default actions". bash interprets it so that traps which
1680 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1682 * Problem: the above approach makes it unwieldy to catch signals while
1683 * we are in read builtin, or while we read commands from stdin:
1684 * masked signals are not visible!
1686 * New implementation
1687 * ==================
1688 * We record each signal we are interested in by installing signal handler
1689 * for them - a bit like emulating kernel pending signal mask in userspace.
1690 * We are interested in: signals which need to have special handling
1691 * as described above, and all signals which have traps set.
1692 * Signals are recorded in pending_set.
1693 * After each pipe execution, we extract any pending signals
1696 * unsigned special_sig_mask: a mask of shell-special signals.
1697 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1698 * char *traps[sig] if trap for sig is set (even if it's '').
1699 * sigset_t pending_set: set of sigs we received.
1702 * if sig is in special_sig_mask, set handler back to:
1703 * record_pending_signo, or to IGN if it's a tty stop signal
1704 * if sig is in fatal_sig_mask, set handler back to sigexit.
1705 * else: set handler back to SIG_DFL
1706 * "trap 'cmd' SIGxxx":
1707 * set handler to record_pending_signo.
1709 * set handler to SIG_IGN.
1710 * after [v]fork, if we plan to be a shell:
1711 * set signals with special interactive handling to SIG_DFL
1712 * (because child shell is not interactive),
1713 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1714 * after [v]fork, if we plan to exec:
1715 * POSIX says fork clears pending signal mask in child - no need to clear it.
1717 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1718 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1721 * Standard says "When a subshell is entered, traps that are not being ignored
1722 * are set to the default actions". bash interprets it so that traps which
1723 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1726 SPECIAL_INTERACTIVE_SIGS = 0
1731 SPECIAL_JOBSTOP_SIGS = 0
1740 static void record_pending_signo(int sig)
1742 sigaddset(&G.pending_set, sig);
1743 #if ENABLE_HUSH_FAST
1744 if (sig == SIGCHLD) {
1746 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1751 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1753 struct sigaction old_sa;
1755 /* We could use signal() to install handlers... almost:
1756 * except that we need to mask ALL signals while handlers run.
1757 * I saw signal nesting in strace, race window isn't small.
1758 * SA_RESTART is also needed, but in Linux, signal()
1759 * sets SA_RESTART too.
1761 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1762 /* sigfillset(&G.sa.sa_mask); - already done */
1763 /* G.sa.sa_flags = SA_RESTART; - already done */
1764 G.sa.sa_handler = handler;
1765 sigaction(sig, &G.sa, &old_sa);
1766 return old_sa.sa_handler;
1769 static void hush_exit(int exitcode) NORETURN;
1771 static void restore_ttypgrp_and__exit(void) NORETURN;
1772 static void restore_ttypgrp_and__exit(void)
1774 /* xfunc has failed! die die die */
1775 /* no EXIT traps, this is an escape hatch! */
1777 hush_exit(xfunc_error_retval);
1782 /* Needed only on some libc:
1783 * It was observed that on exit(), fgetc'ed buffered data
1784 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1785 * With the net effect that even after fork(), not vfork(),
1786 * exit() in NOEXECed applet in "sh SCRIPT":
1787 * noexec_applet_here
1788 * echo END_OF_SCRIPT
1789 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1790 * This makes "echo END_OF_SCRIPT" executed twice.
1791 * Similar problems can be seen with die_if_script() -> xfunc_die()
1792 * and in `cmd` handling.
1793 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1795 static void fflush_and__exit(void) NORETURN;
1796 static void fflush_and__exit(void)
1799 _exit(xfunc_error_retval);
1802 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1803 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1804 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1805 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1807 /* Restores tty foreground process group, and exits.
1808 * May be called as signal handler for fatal signal
1809 * (will resend signal to itself, producing correct exit state)
1810 * or called directly with -EXITCODE.
1811 * We also call it if xfunc is exiting.
1813 static void sigexit(int sig) NORETURN;
1814 static void sigexit(int sig)
1816 /* Careful: we can end up here after [v]fork. Do not restore
1817 * tty pgrp then, only top-level shell process does that */
1818 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1819 /* Disable all signals: job control, SIGPIPE, etc.
1820 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1822 sigprocmask_allsigs(SIG_BLOCK);
1823 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1826 /* Not a signal, just exit */
1830 kill_myself_with_sig(sig); /* does not return */
1834 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1835 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1839 static sighandler_t pick_sighandler(unsigned sig)
1841 sighandler_t handler = SIG_DFL;
1842 if (sig < sizeof(unsigned)*8) {
1843 unsigned sigmask = (1 << sig);
1847 if (G_fatal_sig_mask & sigmask)
1851 /* sig has special handling? */
1852 if (G.special_sig_mask & sigmask) {
1853 handler = record_pending_signo;
1854 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1855 * in order to ignore them: they will be raised
1856 * in an endless loop when we try to do some
1857 * terminal ioctls! We do have to _ignore_ these.
1859 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1866 /* Restores tty foreground process group, and exits. */
1867 static void hush_exit(int exitcode)
1869 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1870 save_history(G.line_input_state);
1874 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1876 /* argv[0] is unused */
1877 argv[1] = G_traps[0];
1879 G.exiting = 1; /* prevent EXIT trap recursion */
1880 /* Note: G_traps[0] is not cleared!
1881 * "trap" will still show it, if executed
1886 #if ENABLE_FEATURE_CLEAN_UP
1888 struct variable *cur_var;
1889 if (G.cwd != bb_msg_unknown)
1891 cur_var = G.top_var;
1893 struct variable *tmp = cur_var;
1894 if (!cur_var->max_len)
1895 free(cur_var->varstr);
1896 cur_var = cur_var->next;
1904 sigexit(- (exitcode & 0xff));
1911 //TODO: return a mask of ALL handled sigs?
1912 static int check_and_run_traps(void)
1919 if (sigisemptyset(&G.pending_set))
1924 if (sigismember(&G.pending_set, sig)) {
1925 sigdelset(&G.pending_set, sig);
1928 } while (sig < NSIG);
1931 if (G_traps && G_traps[sig]) {
1932 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1933 if (G_traps[sig][0]) {
1934 /* We have user-defined handler */
1935 smalluint save_rcode;
1937 /* argv[0] is unused */
1938 argv[1] = G_traps[sig];
1940 save_rcode = G.last_exitcode;
1942 //FIXME: shouldn't it be set to 128 + sig instead?
1943 G.last_exitcode = save_rcode;
1945 } /* else: "" trap, ignoring signal */
1948 /* not a trap: special action */
1951 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1958 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1959 /* bash is observed to signal whole process groups,
1960 * not individual processes */
1961 for (job = G.job_list; job; job = job->next) {
1964 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1965 if (kill(- job->pgrp, SIGHUP) == 0)
1966 kill(- job->pgrp, SIGCONT);
1971 #if ENABLE_HUSH_FAST
1973 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1975 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1977 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1978 * This simplifies wait builtin a bit.
1982 default: /* ignored: */
1983 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1984 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1986 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1987 * Example: wait is not interrupted by TERM
1988 * in interactive shell, because TERM is ignored.
1997 static const char *get_cwd(int force)
1999 if (force || G.cwd == NULL) {
2000 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2001 * we must not try to free(bb_msg_unknown) */
2002 if (G.cwd == bb_msg_unknown)
2004 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2006 G.cwd = bb_msg_unknown;
2013 * Shell and environment variable support
2015 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2017 struct variable **pp;
2018 struct variable *cur;
2021 while ((cur = *pp) != NULL) {
2022 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2029 static const char* FAST_FUNC get_local_var_value(const char *name)
2031 struct variable **vpp;
2032 unsigned len = strlen(name);
2034 if (G.expanded_assignments) {
2035 char **cpp = G.expanded_assignments;
2038 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2039 return cp + len + 1;
2044 vpp = get_ptr_to_local_var(name, len);
2046 return (*vpp)->varstr + len + 1;
2048 if (strcmp(name, "PPID") == 0)
2049 return utoa(G.root_ppid);
2050 // bash compat: UID? EUID?
2051 #if ENABLE_HUSH_RANDOM_SUPPORT
2052 if (strcmp(name, "RANDOM") == 0)
2053 return utoa(next_random(&G.random_gen));
2058 /* str holds "NAME=VAL" and is expected to be malloced.
2059 * We take ownership of it.
2061 #define SETFLAG_EXPORT (1 << 0)
2062 #define SETFLAG_UNEXPORT (1 << 1)
2063 #define SETFLAG_MAKE_RO (1 << 2)
2064 #define SETFLAG_LOCAL_SHIFT 3
2065 static int set_local_var(char *str, unsigned flags)
2067 struct variable **var_pp;
2068 struct variable *cur;
2069 char *free_me = NULL;
2072 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2074 eq_sign = strchr(str, '=');
2075 if (!eq_sign) { /* not expected to ever happen? */
2080 name_len = eq_sign - str + 1; /* including '=' */
2081 var_pp = &G.top_var;
2082 while ((cur = *var_pp) != NULL) {
2083 if (strncmp(cur->varstr, str, name_len) != 0) {
2084 var_pp = &cur->next;
2088 /* We found an existing var with this name */
2089 if (cur->flg_read_only) {
2090 bb_error_msg("%s: readonly variable", str);
2092 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2093 //but export per se succeeds (does put the var in env). We don't mimic that.
2096 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2097 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2102 #if ENABLE_HUSH_LOCAL
2103 if (cur->func_nest_level < local_lvl) {
2104 /* New variable is declared as local,
2105 * and existing one is global, or local
2106 * from enclosing function.
2107 * Remove and save old one: */
2108 *var_pp = cur->next;
2109 cur->next = *G.shadowed_vars_pp;
2110 *G.shadowed_vars_pp = cur;
2111 /* bash 3.2.33(1) and exported vars:
2113 * # f() { local z=a; env | grep ^z; }
2119 if (cur->flg_export)
2120 flags |= SETFLAG_EXPORT;
2124 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2129 if (cur->max_len != 0) {
2130 if (cur->max_len >= strlen(str)) {
2131 /* This one is from startup env, reuse space */
2132 strcpy(cur->varstr, str);
2137 goto set_str_and_exp;
2139 /* max_len == 0 signifies "malloced" var, which we can
2140 * (and have to) free. But we can't free(cur->varstr) here:
2141 * if cur->flg_export is 1, it is in the environment.
2142 * We should either unsetenv+free, or wait until putenv,
2143 * then putenv(new)+free(old).
2145 free_me = cur->varstr;
2146 goto set_str_and_exp;
2149 /* Not found - create new variable struct */
2150 cur = xzalloc(sizeof(*cur));
2151 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2152 cur->next = *var_pp;
2158 #if !BB_MMU || ENABLE_HUSH_READONLY
2159 if (flags & SETFLAG_MAKE_RO) {
2160 cur->flg_read_only = 1;
2163 if (flags & SETFLAG_EXPORT)
2164 cur->flg_export = 1;
2165 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2166 cmdedit_update_prompt();
2167 if (cur->flg_export) {
2168 if (flags & SETFLAG_UNEXPORT) {
2169 cur->flg_export = 0;
2170 /* unsetenv was already done */
2173 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2174 i = putenv(cur->varstr);
2175 /* only now we can free old exported malloced string */
2184 /* Used at startup and after each cd */
2185 static void set_pwd_var(unsigned flag)
2187 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2190 static int unset_local_var_len(const char *name, int name_len)
2192 struct variable *cur;
2193 struct variable **var_pp;
2196 return EXIT_SUCCESS;
2197 var_pp = &G.top_var;
2198 while ((cur = *var_pp) != NULL) {
2199 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2200 if (cur->flg_read_only) {
2201 bb_error_msg("%s: readonly variable", name);
2202 return EXIT_FAILURE;
2204 *var_pp = cur->next;
2205 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2206 bb_unsetenv(cur->varstr);
2207 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2208 cmdedit_update_prompt();
2212 return EXIT_SUCCESS;
2214 var_pp = &cur->next;
2216 return EXIT_SUCCESS;
2219 #if ENABLE_HUSH_UNSET
2220 static int unset_local_var(const char *name)
2222 return unset_local_var_len(name, strlen(name));
2226 static void unset_vars(char **strings)
2234 const char *eq = strchrnul(*v, '=');
2235 unset_local_var_len(*v, (int)(eq - *v));
2241 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2242 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2244 char *var = xasprintf("%s=%s", name, val);
2245 set_local_var(var, /*flag:*/ 0);
2251 * Helpers for "var1=val1 var2=val2 cmd" feature
2253 static void add_vars(struct variable *var)
2255 struct variable *next;
2259 var->next = G.top_var;
2261 if (var->flg_export) {
2262 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2263 putenv(var->varstr);
2265 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2271 static struct variable *set_vars_and_save_old(char **strings)
2274 struct variable *old = NULL;
2280 struct variable *var_p;
2281 struct variable **var_pp;
2284 eq = strchr(*s, '=');
2286 var_pp = get_ptr_to_local_var(*s, eq - *s);
2289 if (var_p->flg_read_only) {
2291 bb_error_msg("%s: readonly variable", *s);
2293 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2294 * If VAR is readonly, leaving it in the list
2295 * after asssignment error (msg above)
2296 * causes doubled error message later, on unset.
2298 debug_printf_env("removing/freeing '%s' element\n", *s);
2301 do { *p = p[1]; p++; } while (*p);
2304 /* Remove variable from global linked list */
2305 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2306 *var_pp = var_p->next;
2307 /* Add it to returned list */
2311 set_local_var(*s, SETFLAG_EXPORT);
2323 static void reinit_unicode_for_hush(void)
2325 /* Unicode support should be activated even if LANG is set
2326 * _during_ shell execution, not only if it was set when
2327 * shell was started. Therefore, re-check LANG every time:
2329 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2330 || ENABLE_UNICODE_USING_LOCALE
2332 const char *s = get_local_var_value("LC_ALL");
2333 if (!s) s = get_local_var_value("LC_CTYPE");
2334 if (!s) s = get_local_var_value("LANG");
2340 * in_str support (strings, and "strings" read from files).
2343 #if ENABLE_HUSH_INTERACTIVE
2344 /* To test correct lineedit/interactive behavior, type from command line:
2350 * It exercises a lot of corner cases.
2352 static void cmdedit_update_prompt(void)
2354 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2355 G.PS1 = get_local_var_value("PS1");
2358 G.PS2 = get_local_var_value("PS2");
2365 static const char *setup_prompt_string(int promptmode)
2367 const char *prompt_str;
2368 debug_printf("setup_prompt_string %d ", promptmode);
2369 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2370 /* Set up the prompt */
2371 if (promptmode == 0) { /* PS1 */
2373 /* bash uses $PWD value, even if it is set by user.
2374 * It uses current dir only if PWD is unset.
2375 * We always use current dir. */
2376 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2381 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2382 debug_printf("prompt_str '%s'\n", prompt_str);
2385 static int get_user_input(struct in_str *i)
2388 const char *prompt_str;
2390 prompt_str = setup_prompt_string(i->promptmode);
2391 # if ENABLE_FEATURE_EDITING
2393 reinit_unicode_for_hush();
2394 if (G.flag_SIGINT) {
2395 /* There was ^C'ed, make it look prettier: */
2399 /* buglet: SIGINT will not make new prompt to appear _at once_,
2400 * only after <Enter>. (^C works immediately) */
2401 r = read_line_input(G.line_input_state, prompt_str,
2402 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2405 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2407 write(STDOUT_FILENO, "^C", 2);
2410 check_and_run_traps();
2411 if (r != 0 && !G.flag_SIGINT)
2413 /* ^C or SIGINT: repeat */
2414 G.last_exitcode = 128 + SIGINT;
2417 /* EOF/error detected */
2419 i->peek_buf[0] = r = EOF;
2422 i->p = G.user_input_buf;
2423 return (unsigned char)*i->p++;
2427 if (i->last_char == '\0' || i->last_char == '\n') {
2428 /* Why check_and_run_traps here? Try this interactively:
2429 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2430 * $ <[enter], repeatedly...>
2431 * Without check_and_run_traps, handler never runs.
2433 check_and_run_traps();
2434 fputs(prompt_str, stdout);
2437 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2439 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2440 * no ^C masking happens during fgetc, no special code for ^C:
2441 * it generates SIGINT as usual.
2443 check_and_run_traps();
2445 G.last_exitcode = 128 + SIGINT;
2452 /* This is the magic location that prints prompts
2453 * and gets data back from the user */
2454 static int fgetc_interactive(struct in_str *i)
2457 /* If it's interactive stdin, get new line. */
2458 if (G_interactive_fd && i->file == stdin) {
2459 /* Returns first char (or EOF), the rest is in i->p[] */
2460 ch = get_user_input(i);
2461 i->promptmode = 1; /* PS2 */
2463 /* Not stdin: script file, sourced file, etc */
2464 do ch = fgetc(i->file); while (ch == '\0');
2469 static inline int fgetc_interactive(struct in_str *i)
2472 do ch = fgetc(i->file); while (ch == '\0');
2475 #endif /* INTERACTIVE */
2477 static int i_getch(struct in_str *i)
2482 /* string-based in_str */
2483 ch = (unsigned char)*i->p;
2492 /* FILE-based in_str */
2494 #if ENABLE_FEATURE_EDITING
2495 /* This can be stdin, check line editing char[] buffer */
2496 if (i->p && *i->p != '\0') {
2497 ch = (unsigned char)*i->p++;
2501 /* peek_buf[] is an int array, not char. Can contain EOF. */
2502 ch = i->peek_buf[0];
2504 int ch2 = i->peek_buf[1];
2505 i->peek_buf[0] = ch2;
2506 if (ch2 == 0) /* very likely, avoid redundant write */
2512 ch = fgetc_interactive(i);
2514 debug_printf("file_get: got '%c' %d\n", ch, ch);
2519 static int i_peek(struct in_str *i)
2524 /* string-based in_str */
2525 /* Doesn't report EOF on NUL. None of the callers care. */
2526 return (unsigned char)*i->p;
2529 /* FILE-based in_str */
2531 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2532 /* This can be stdin, check line editing char[] buffer */
2533 if (i->p && *i->p != '\0')
2534 return (unsigned char)*i->p;
2536 /* peek_buf[] is an int array, not char. Can contain EOF. */
2537 ch = i->peek_buf[0];
2541 /* Need to get a new char */
2542 ch = fgetc_interactive(i);
2543 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2545 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2546 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2552 i->peek_buf[0] = ch;
2553 /*i->peek_buf[1] = 0; - already is */
2557 /* Only ever called if i_peek() was called, and did not return EOF.
2558 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2559 * not end-of-line. Therefore we never need to read a new editing line here.
2561 static int i_peek2(struct in_str *i)
2565 /* There are two cases when i->p[] buffer exists.
2566 * (1) it's a string in_str.
2567 * (2) It's a file, and we have a saved line editing buffer.
2568 * In both cases, we know that i->p[0] exists and not NUL, and
2569 * the peek2 result is in i->p[1].
2572 return (unsigned char)i->p[1];
2574 /* Now we know it is a file-based in_str. */
2576 /* peek_buf[] is an int array, not char. Can contain EOF. */
2577 /* Is there 2nd char? */
2578 ch = i->peek_buf[1];
2580 /* We did not read it yet, get it now */
2581 do ch = fgetc(i->file); while (ch == '\0');
2582 i->peek_buf[1] = ch;
2585 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2589 static void setup_file_in_str(struct in_str *i, FILE *f)
2591 memset(i, 0, sizeof(*i));
2592 /* i->promptmode = 0; - PS1 (memset did it) */
2597 static void setup_string_in_str(struct in_str *i, const char *s)
2599 memset(i, 0, sizeof(*i));
2600 /* i->promptmode = 0; - PS1 (memset did it) */
2601 /*i->file = NULL */;
2609 #define B_CHUNK (32 * sizeof(char*))
2611 static void o_reset_to_empty_unquoted(o_string *o)
2614 o->has_quoted_part = 0;
2619 static void o_free(o_string *o)
2622 memset(o, 0, sizeof(*o));
2625 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2630 static void o_grow_by(o_string *o, int len)
2632 if (o->length + len > o->maxlen) {
2633 o->maxlen += (2 * len) | (B_CHUNK-1);
2634 o->data = xrealloc(o->data, 1 + o->maxlen);
2638 static void o_addchr(o_string *o, int ch)
2640 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2641 if (o->length < o->maxlen) {
2642 /* likely. avoid o_grow_by() call */
2644 o->data[o->length] = ch;
2646 o->data[o->length] = '\0';
2654 /* Valid only if we know o_string is not empty */
2655 static void o_delchr(o_string *o)
2658 o->data[o->length] = '\0';
2662 static void o_addblock(o_string *o, const char *str, int len)
2665 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2669 static void o_addstr(o_string *o, const char *str)
2671 o_addblock(o, str, strlen(str));
2675 static void nommu_addchr(o_string *o, int ch)
2681 # define nommu_addchr(o, str) ((void)0)
2684 static void o_addstr_with_NUL(o_string *o, const char *str)
2686 o_addblock(o, str, strlen(str) + 1);
2690 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2691 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2692 * Apparently, on unquoted $v bash still does globbing
2693 * ("v='*.txt'; echo $v" prints all .txt files),
2694 * but NOT brace expansion! Thus, there should be TWO independent
2695 * quoting mechanisms on $v expansion side: one protects
2696 * $v from brace expansion, and other additionally protects "$v" against globbing.
2697 * We have only second one.
2700 #if ENABLE_HUSH_BRACE_EXPANSION
2701 # define MAYBE_BRACES "{}"
2703 # define MAYBE_BRACES ""
2706 /* My analysis of quoting semantics tells me that state information
2707 * is associated with a destination, not a source.
2709 static void o_addqchr(o_string *o, int ch)
2712 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2717 o->data[o->length] = '\\';
2720 o->data[o->length] = ch;
2722 o->data[o->length] = '\0';
2725 static void o_addQchr(o_string *o, int ch)
2728 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2729 && strchr("*?[\\" MAYBE_BRACES, ch)
2732 o->data[o->length] = '\\';
2736 o->data[o->length] = ch;
2738 o->data[o->length] = '\0';
2741 static void o_addqblock(o_string *o, const char *str, int len)
2746 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2747 if (ordinary_cnt > len) /* paranoia */
2749 o_addblock(o, str, ordinary_cnt);
2750 if (ordinary_cnt == len)
2751 return; /* NUL is already added by o_addblock */
2752 str += ordinary_cnt;
2753 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2757 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2759 o->data[o->length] = '\\';
2763 o->data[o->length] = ch;
2766 o->data[o->length] = '\0';
2769 static void o_addQblock(o_string *o, const char *str, int len)
2771 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2772 o_addblock(o, str, len);
2775 o_addqblock(o, str, len);
2778 static void o_addQstr(o_string *o, const char *str)
2780 o_addQblock(o, str, strlen(str));
2783 /* A special kind of o_string for $VAR and `cmd` expansion.
2784 * It contains char* list[] at the beginning, which is grown in 16 element
2785 * increments. Actual string data starts at the next multiple of 16 * (char*).
2786 * list[i] contains an INDEX (int!) into this string data.
2787 * It means that if list[] needs to grow, data needs to be moved higher up
2788 * but list[i]'s need not be modified.
2789 * NB: remembering how many list[i]'s you have there is crucial.
2790 * o_finalize_list() operation post-processes this structure - calculates
2791 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2793 #if DEBUG_EXPAND || DEBUG_GLOB
2794 static void debug_print_list(const char *prefix, o_string *o, int n)
2796 char **list = (char**)o->data;
2797 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2801 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2802 prefix, list, n, string_start, o->length, o->maxlen,
2803 !!(o->o_expflags & EXP_FLAG_GLOB),
2805 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2808 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2809 o->data + (int)(uintptr_t)list[i] + string_start,
2810 o->data + (int)(uintptr_t)list[i] + string_start);
2814 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2816 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2820 # define debug_print_list(prefix, o, n) ((void)0)
2823 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2824 * in list[n] so that it points past last stored byte so far.
2825 * It returns n+1. */
2826 static int o_save_ptr_helper(o_string *o, int n)
2828 char **list = (char**)o->data;
2832 if (!o->has_empty_slot) {
2833 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2834 string_len = o->length - string_start;
2835 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2836 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2837 /* list[n] points to string_start, make space for 16 more pointers */
2838 o->maxlen += 0x10 * sizeof(list[0]);
2839 o->data = xrealloc(o->data, o->maxlen + 1);
2840 list = (char**)o->data;
2841 memmove(list + n + 0x10, list + n, string_len);
2842 o->length += 0x10 * sizeof(list[0]);
2844 debug_printf_list("list[%d]=%d string_start=%d\n",
2845 n, string_len, string_start);
2848 /* We have empty slot at list[n], reuse without growth */
2849 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2850 string_len = o->length - string_start;
2851 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2852 n, string_len, string_start);
2853 o->has_empty_slot = 0;
2855 o->has_quoted_part = 0;
2856 list[n] = (char*)(uintptr_t)string_len;
2860 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2861 static int o_get_last_ptr(o_string *o, int n)
2863 char **list = (char**)o->data;
2864 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2866 return ((int)(uintptr_t)list[n-1]) + string_start;
2869 #if ENABLE_HUSH_BRACE_EXPANSION
2870 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2871 * first, it processes even {a} (no commas), second,
2872 * I didn't manage to make it return strings when they don't match
2873 * existing files. Need to re-implement it.
2877 static int glob_needed(const char *s)
2886 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2892 /* Return pointer to next closing brace or to comma */
2893 static const char *next_brace_sub(const char *cp)
2897 while (*cp != '\0') {
2904 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2910 return *cp != '\0' ? cp : NULL;
2912 /* Recursive brace globber. Note: may garble pattern[]. */
2913 static int glob_brace(char *pattern, o_string *o, int n)
2915 char *new_pattern_buf;
2922 debug_printf_glob("glob_brace('%s')\n", pattern);
2928 if (*begin == '{') {
2929 /* Find the first sub-pattern and at the same time
2930 * find the rest after the closing brace */
2931 next = next_brace_sub(begin);
2933 /* An illegal expression */
2937 /* "{abc}" with no commas - illegal
2938 * brace expr, disregard and skip it */
2944 if (*begin == '\\' && begin[1] != '\0')
2948 debug_printf_glob("begin:%s\n", begin);
2949 debug_printf_glob("next:%s\n", next);
2951 /* Now find the end of the whole brace expression */
2953 while (*rest != '}') {
2954 rest = next_brace_sub(rest);
2956 /* An illegal expression */
2959 debug_printf_glob("rest:%s\n", rest);
2961 rest_len = strlen(++rest) + 1;
2963 /* We are sure the brace expression is well-formed */
2965 /* Allocate working buffer large enough for our work */
2966 new_pattern_buf = xmalloc(strlen(pattern));
2968 /* We have a brace expression. BEGIN points to the opening {,
2969 * NEXT points past the terminator of the first element, and REST
2970 * points past the final }. We will accumulate result names from
2971 * recursive runs for each brace alternative in the buffer using
2976 /* Construct the new glob expression */
2979 mempcpy(new_pattern_buf,
2980 /* We know the prefix for all sub-patterns */
2981 pattern, begin - pattern),
2985 /* Note: glob_brace() may garble new_pattern_buf[].
2986 * That's why we re-copy prefix every time (1st memcpy above).
2988 n = glob_brace(new_pattern_buf, o, n);
2990 /* We saw the last entry */
2994 next = next_brace_sub(next);
2996 free(new_pattern_buf);
3004 memset(&globdata, 0, sizeof(globdata));
3005 gr = glob(pattern, 0, NULL, &globdata);
3006 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3008 if (gr == GLOB_NOMATCH) {
3009 globfree(&globdata);
3010 /* NB: garbles parameter */
3011 unbackslash(pattern);
3012 o_addstr_with_NUL(o, pattern);
3013 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3014 return o_save_ptr_helper(o, n);
3016 if (gr == GLOB_NOSPACE)
3017 bb_error_msg_and_die(bb_msg_memory_exhausted);
3018 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3019 * but we didn't specify it. Paranoia again. */
3020 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3022 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3023 char **argv = globdata.gl_pathv;
3025 o_addstr_with_NUL(o, *argv);
3026 n = o_save_ptr_helper(o, n);
3032 globfree(&globdata);
3036 /* Performs globbing on last list[],
3037 * saving each result as a new list[].
3039 static int perform_glob(o_string *o, int n)
3041 char *pattern, *copy;
3043 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3045 return o_save_ptr_helper(o, n);
3046 pattern = o->data + o_get_last_ptr(o, n);
3047 debug_printf_glob("glob pattern '%s'\n", pattern);
3048 if (!glob_needed(pattern)) {
3049 /* unbackslash last string in o in place, fix length */
3050 o->length = unbackslash(pattern) - o->data;
3051 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3052 return o_save_ptr_helper(o, n);
3055 copy = xstrdup(pattern);
3056 /* "forget" pattern in o */
3057 o->length = pattern - o->data;
3058 n = glob_brace(copy, o, n);
3061 debug_print_list("perform_glob returning", o, n);
3065 #else /* !HUSH_BRACE_EXPANSION */
3068 static int glob_needed(const char *s)
3077 if (*s == '*' || *s == '[' || *s == '?')
3083 /* Performs globbing on last list[],
3084 * saving each result as a new list[].
3086 static int perform_glob(o_string *o, int n)
3092 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3094 return o_save_ptr_helper(o, n);
3095 pattern = o->data + o_get_last_ptr(o, n);
3096 debug_printf_glob("glob pattern '%s'\n", pattern);
3097 if (!glob_needed(pattern)) {
3099 /* unbackslash last string in o in place, fix length */
3100 o->length = unbackslash(pattern) - o->data;
3101 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3102 return o_save_ptr_helper(o, n);
3105 memset(&globdata, 0, sizeof(globdata));
3106 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3107 * If we glob "*.\*" and don't find anything, we need
3108 * to fall back to using literal "*.*", but GLOB_NOCHECK
3109 * will return "*.\*"!
3111 gr = glob(pattern, 0, NULL, &globdata);
3112 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3114 if (gr == GLOB_NOMATCH) {
3115 globfree(&globdata);
3118 if (gr == GLOB_NOSPACE)
3119 bb_error_msg_and_die(bb_msg_memory_exhausted);
3120 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3121 * but we didn't specify it. Paranoia again. */
3122 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3124 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3125 char **argv = globdata.gl_pathv;
3126 /* "forget" pattern in o */
3127 o->length = pattern - o->data;
3129 o_addstr_with_NUL(o, *argv);
3130 n = o_save_ptr_helper(o, n);
3136 globfree(&globdata);
3138 debug_print_list("perform_glob returning", o, n);
3142 #endif /* !HUSH_BRACE_EXPANSION */
3144 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3145 * Otherwise, just finish current list[] and start new */
3146 static int o_save_ptr(o_string *o, int n)
3148 if (o->o_expflags & EXP_FLAG_GLOB) {
3149 /* If o->has_empty_slot, list[n] was already globbed
3150 * (if it was requested back then when it was filled)
3151 * so don't do that again! */
3152 if (!o->has_empty_slot)
3153 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3155 return o_save_ptr_helper(o, n);
3158 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3159 static char **o_finalize_list(o_string *o, int n)
3164 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3166 debug_print_list("finalized", o, n);
3167 debug_printf_expand("finalized n:%d\n", n);
3168 list = (char**)o->data;
3169 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3173 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3178 static void free_pipe_list(struct pipe *pi);
3180 /* Returns pi->next - next pipe in the list */
3181 static struct pipe *free_pipe(struct pipe *pi)
3186 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3187 for (i = 0; i < pi->num_cmds; i++) {
3188 struct command *command;
3189 struct redir_struct *r, *rnext;
3191 command = &pi->cmds[i];
3192 debug_printf_clean(" command %d:\n", i);
3193 if (command->argv) {
3197 for (a = 0, p = command->argv; *p; a++, p++) {
3198 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3201 free_strings(command->argv);
3202 //command->argv = NULL;
3204 /* not "else if": on syntax error, we may have both! */
3205 if (command->group) {
3206 debug_printf_clean(" begin group (cmd_type:%d)\n",
3208 free_pipe_list(command->group);
3209 debug_printf_clean(" end group\n");
3210 //command->group = NULL;
3212 /* else is crucial here.
3213 * If group != NULL, child_func is meaningless */
3214 #if ENABLE_HUSH_FUNCTIONS
3215 else if (command->child_func) {
3216 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3217 command->child_func->parent_cmd = NULL;
3221 free(command->group_as_string);
3222 //command->group_as_string = NULL;
3224 for (r = command->redirects; r; r = rnext) {
3225 debug_printf_clean(" redirect %d%s",
3226 r->rd_fd, redir_table[r->rd_type].descrip);
3227 /* guard against the case >$FOO, where foo is unset or blank */
3228 if (r->rd_filename) {
3229 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3230 free(r->rd_filename);
3231 //r->rd_filename = NULL;
3233 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3237 //command->redirects = NULL;
3239 free(pi->cmds); /* children are an array, they get freed all at once */
3243 //pi->cmdtext = NULL;
3251 static void free_pipe_list(struct pipe *pi)
3255 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3257 debug_printf_clean("pipe followup code %d\n", pi->followup);
3263 /*** Parsing routines ***/
3265 #ifndef debug_print_tree
3266 static void debug_print_tree(struct pipe *pi, int lvl)
3268 static const char *const PIPE[] = {
3274 static const char *RES[] = {
3275 [RES_NONE ] = "NONE" ,
3278 [RES_THEN ] = "THEN" ,
3279 [RES_ELIF ] = "ELIF" ,
3280 [RES_ELSE ] = "ELSE" ,
3283 # if ENABLE_HUSH_LOOPS
3284 [RES_FOR ] = "FOR" ,
3285 [RES_WHILE] = "WHILE",
3286 [RES_UNTIL] = "UNTIL",
3288 [RES_DONE ] = "DONE" ,
3290 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3293 # if ENABLE_HUSH_CASE
3294 [RES_CASE ] = "CASE" ,
3295 [RES_CASE_IN ] = "CASE_IN" ,
3296 [RES_MATCH] = "MATCH",
3297 [RES_CASE_BODY] = "CASE_BODY",
3298 [RES_ESAC ] = "ESAC" ,
3300 [RES_XXXX ] = "XXXX" ,
3301 [RES_SNTX ] = "SNTX" ,
3303 static const char *const CMDTYPE[] = {
3307 # if ENABLE_HUSH_FUNCTIONS
3316 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3317 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3319 while (prn < pi->num_cmds) {
3320 struct command *command = &pi->cmds[prn];
3321 char **argv = command->argv;
3323 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3325 command->assignment_cnt);
3326 if (command->group) {
3327 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3328 CMDTYPE[command->cmd_type],
3331 , " group_as_string:", command->group_as_string
3336 debug_print_tree(command->group, lvl+1);
3340 if (argv) while (*argv) {
3341 fdprintf(2, " '%s'", *argv);
3351 #endif /* debug_print_tree */
3353 static struct pipe *new_pipe(void)
3356 pi = xzalloc(sizeof(struct pipe));
3357 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3361 /* Command (member of a pipe) is complete, or we start a new pipe
3362 * if ctx->command is NULL.
3363 * No errors possible here.
3365 static int done_command(struct parse_context *ctx)
3367 /* The command is really already in the pipe structure, so
3368 * advance the pipe counter and make a new, null command. */
3369 struct pipe *pi = ctx->pipe;
3370 struct command *command = ctx->command;
3372 #if 0 /* Instead we emit error message at run time */
3373 if (ctx->pending_redirect) {
3374 /* For example, "cmd >" (no filename to redirect to) */
3375 die_if_script("syntax error: %s", "invalid redirect");
3376 ctx->pending_redirect = NULL;
3381 if (IS_NULL_CMD(command)) {
3382 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3386 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3387 //debug_print_tree(ctx->list_head, 20);
3389 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3392 /* Only real trickiness here is that the uncommitted
3393 * command structure is not counted in pi->num_cmds. */
3394 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3395 ctx->command = command = &pi->cmds[pi->num_cmds];
3397 memset(command, 0, sizeof(*command));
3398 return pi->num_cmds; /* used only for 0/nonzero check */
3401 static void done_pipe(struct parse_context *ctx, pipe_style type)
3405 debug_printf_parse("done_pipe entered, followup %d\n", type);
3406 /* Close previous command */
3407 not_null = done_command(ctx);
3409 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3410 ctx->ctx_inverted = 0;
3411 ctx->pipe->res_word = ctx->ctx_res_w;
3413 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3414 /* Necessary since && and || have precedence over &:
3415 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3416 * in a backgrounded subshell.
3419 struct command *command;
3421 /* Is this actually this construct, all pipes end with && or ||? */
3422 pi = ctx->list_head;
3423 while (pi != ctx->pipe) {
3424 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3429 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3430 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3431 pi = xzalloc(sizeof(*pi));
3432 pi->followup = PIPE_BG;
3434 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3435 command = &pi->cmds[0];
3436 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3437 command->cmd_type = CMD_NORMAL;
3438 command->group = ctx->list_head;
3440 command->group_as_string = xstrndup(
3441 ctx->as_string.data,
3442 ctx->as_string.length - 1 /* do not copy last char, "&" */
3445 /* Replace all pipes in ctx with one newly created */
3446 ctx->list_head = ctx->pipe = pi;
3449 ctx->pipe->followup = type;
3452 /* Without this check, even just <enter> on command line generates
3453 * tree of three NOPs (!). Which is harmless but annoying.
3454 * IOW: it is safe to do it unconditionally. */
3457 || ctx->ctx_res_w == RES_FI
3459 #if ENABLE_HUSH_LOOPS
3460 || ctx->ctx_res_w == RES_DONE
3461 || ctx->ctx_res_w == RES_FOR
3462 || ctx->ctx_res_w == RES_IN
3464 #if ENABLE_HUSH_CASE
3465 || ctx->ctx_res_w == RES_ESAC
3469 debug_printf_parse("done_pipe: adding new pipe: "
3470 "not_null:%d ctx->ctx_res_w:%d\n",
3471 not_null, ctx->ctx_res_w);
3473 ctx->pipe->next = new_p;
3475 /* RES_THEN, RES_DO etc are "sticky" -
3476 * they remain set for pipes inside if/while.
3477 * This is used to control execution.
3478 * RES_FOR and RES_IN are NOT sticky (needed to support
3479 * cases where variable or value happens to match a keyword):
3481 #if ENABLE_HUSH_LOOPS
3482 if (ctx->ctx_res_w == RES_FOR
3483 || ctx->ctx_res_w == RES_IN)
3484 ctx->ctx_res_w = RES_NONE;
3486 #if ENABLE_HUSH_CASE
3487 if (ctx->ctx_res_w == RES_MATCH)
3488 ctx->ctx_res_w = RES_CASE_BODY;
3489 if (ctx->ctx_res_w == RES_CASE)
3490 ctx->ctx_res_w = RES_CASE_IN;
3492 ctx->command = NULL; /* trick done_command below */
3493 /* Create the memory for command, roughly:
3494 * ctx->pipe->cmds = new struct command;
3495 * ctx->command = &ctx->pipe->cmds[0];
3498 //debug_print_tree(ctx->list_head, 10);
3500 debug_printf_parse("done_pipe return\n");
3503 static void initialize_context(struct parse_context *ctx)
3505 memset(ctx, 0, sizeof(*ctx));
3506 ctx->pipe = ctx->list_head = new_pipe();
3507 /* Create the memory for command, roughly:
3508 * ctx->pipe->cmds = new struct command;
3509 * ctx->command = &ctx->pipe->cmds[0];
3514 /* If a reserved word is found and processed, parse context is modified
3515 * and 1 is returned.
3518 struct reserved_combo {
3521 unsigned char assignment_flag;
3525 FLAG_END = (1 << RES_NONE ),
3527 FLAG_IF = (1 << RES_IF ),
3528 FLAG_THEN = (1 << RES_THEN ),
3529 FLAG_ELIF = (1 << RES_ELIF ),
3530 FLAG_ELSE = (1 << RES_ELSE ),
3531 FLAG_FI = (1 << RES_FI ),
3533 # if ENABLE_HUSH_LOOPS
3534 FLAG_FOR = (1 << RES_FOR ),
3535 FLAG_WHILE = (1 << RES_WHILE),
3536 FLAG_UNTIL = (1 << RES_UNTIL),
3537 FLAG_DO = (1 << RES_DO ),
3538 FLAG_DONE = (1 << RES_DONE ),
3539 FLAG_IN = (1 << RES_IN ),
3541 # if ENABLE_HUSH_CASE
3542 FLAG_MATCH = (1 << RES_MATCH),
3543 FLAG_ESAC = (1 << RES_ESAC ),
3545 FLAG_START = (1 << RES_XXXX ),
3548 static const struct reserved_combo* match_reserved_word(o_string *word)
3550 /* Mostly a list of accepted follow-up reserved words.
3551 * FLAG_END means we are done with the sequence, and are ready
3552 * to turn the compound list into a command.
3553 * FLAG_START means the word must start a new compound list.
3555 static const struct reserved_combo reserved_list[] = {
3557 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3558 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3559 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3560 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3561 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3562 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3564 # if ENABLE_HUSH_LOOPS
3565 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3566 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3567 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3568 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3569 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3570 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3572 # if ENABLE_HUSH_CASE
3573 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3574 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3577 const struct reserved_combo *r;
3579 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3580 if (strcmp(word->data, r->literal) == 0)
3585 /* Return 0: not a keyword, 1: keyword
3587 static int reserved_word(o_string *word, struct parse_context *ctx)
3589 # if ENABLE_HUSH_CASE
3590 static const struct reserved_combo reserved_match = {
3591 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3594 const struct reserved_combo *r;
3596 if (word->has_quoted_part)
3598 r = match_reserved_word(word);
3602 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3603 # if ENABLE_HUSH_CASE
3604 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3605 /* "case word IN ..." - IN part starts first MATCH part */
3606 r = &reserved_match;
3609 if (r->flag == 0) { /* '!' */
3610 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3611 syntax_error("! ! command");
3612 ctx->ctx_res_w = RES_SNTX;
3614 ctx->ctx_inverted = 1;
3617 if (r->flag & FLAG_START) {
3618 struct parse_context *old;
3620 old = xmemdup(ctx, sizeof(*ctx));
3621 debug_printf_parse("push stack %p\n", old);
3622 initialize_context(ctx);
3624 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3625 syntax_error_at(word->data);
3626 ctx->ctx_res_w = RES_SNTX;
3629 /* "{...} fi" is ok. "{...} if" is not
3631 * if { echo foo; } then { echo bar; } fi */
3632 if (ctx->command->group)
3633 done_pipe(ctx, PIPE_SEQ);
3636 ctx->ctx_res_w = r->res;
3637 ctx->old_flag = r->flag;
3638 word->o_assignment = r->assignment_flag;
3639 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3641 if (ctx->old_flag & FLAG_END) {
3642 struct parse_context *old;
3644 done_pipe(ctx, PIPE_SEQ);
3645 debug_printf_parse("pop stack %p\n", ctx->stack);
3647 old->command->group = ctx->list_head;
3648 old->command->cmd_type = CMD_NORMAL;
3650 /* At this point, the compound command's string is in
3651 * ctx->as_string... except for the leading keyword!
3652 * Consider this example: "echo a | if true; then echo a; fi"
3653 * ctx->as_string will contain "true; then echo a; fi",
3654 * with "if " remaining in old->as_string!
3658 int len = old->as_string.length;
3659 /* Concatenate halves */
3660 o_addstr(&old->as_string, ctx->as_string.data);
3661 o_free_unsafe(&ctx->as_string);
3662 /* Find where leading keyword starts in first half */
3663 str = old->as_string.data + len;
3664 if (str > old->as_string.data)
3665 str--; /* skip whitespace after keyword */
3666 while (str > old->as_string.data && isalpha(str[-1]))
3668 /* Ugh, we're done with this horrid hack */
3669 old->command->group_as_string = xstrdup(str);
3670 debug_printf_parse("pop, remembering as:'%s'\n",
3671 old->command->group_as_string);
3674 *ctx = *old; /* physical copy */
3679 #endif /* HAS_KEYWORDS */
3681 /* Word is complete, look at it and update parsing context.
3682 * Normal return is 0. Syntax errors return 1.
3683 * Note: on return, word is reset, but not o_free'd!
3685 static int done_word(o_string *word, struct parse_context *ctx)
3687 struct command *command = ctx->command;
3689 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3690 if (word->length == 0 && !word->has_quoted_part) {
3691 debug_printf_parse("done_word return 0: true null, ignored\n");
3695 if (ctx->pending_redirect) {
3696 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3697 * only if run as "bash", not "sh" */
3698 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3700 * ...the word that follows the redirection operator
3701 * shall be subjected to tilde expansion, parameter expansion,
3702 * command substitution, arithmetic expansion, and quote
3703 * removal. Pathname expansion shall not be performed
3704 * on the word by a non-interactive shell; an interactive
3705 * shell may perform it, but shall do so only when
3706 * the expansion would result in one word."
3708 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3709 /* Cater for >\file case:
3710 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3711 * Same with heredocs:
3712 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3714 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3715 unbackslash(ctx->pending_redirect->rd_filename);
3716 /* Is it <<"HEREDOC"? */
3717 if (word->has_quoted_part) {
3718 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3721 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3722 ctx->pending_redirect = NULL;
3725 # if ENABLE_HUSH_CASE
3726 if (ctx->ctx_dsemicolon
3727 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3729 /* already done when ctx_dsemicolon was set to 1: */
3730 /* ctx->ctx_res_w = RES_MATCH; */
3731 ctx->ctx_dsemicolon = 0;
3734 if (!command->argv /* if it's the first word... */
3735 # if ENABLE_HUSH_LOOPS
3736 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3737 && ctx->ctx_res_w != RES_IN
3739 # if ENABLE_HUSH_CASE
3740 && ctx->ctx_res_w != RES_CASE
3743 int reserved = reserved_word(word, ctx);
3744 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3746 o_reset_to_empty_unquoted(word);
3747 debug_printf_parse("done_word return %d\n",
3748 (ctx->ctx_res_w == RES_SNTX));
3749 return (ctx->ctx_res_w == RES_SNTX);
3752 if (strcmp(word->data, "[[") == 0) {
3753 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3759 if (command->group) {
3760 /* "{ echo foo; } echo bar" - bad */
3761 syntax_error_at(word->data);
3762 debug_printf_parse("done_word return 1: syntax error, "
3763 "groups and arglists don't mix\n");
3767 /* If this word wasn't an assignment, next ones definitely
3768 * can't be assignments. Even if they look like ones. */
3769 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3770 && word->o_assignment != WORD_IS_KEYWORD
3772 word->o_assignment = NOT_ASSIGNMENT;
3774 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3775 command->assignment_cnt++;
3776 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3778 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3779 word->o_assignment = MAYBE_ASSIGNMENT;
3781 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3783 if (word->has_quoted_part
3784 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3785 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3786 /* (otherwise it's known to be not empty and is already safe) */
3788 /* exclude "$@" - it can expand to no word despite "" */
3789 char *p = word->data;
3790 while (p[0] == SPECIAL_VAR_SYMBOL
3791 && (p[1] & 0x7f) == '@'
3792 && p[2] == SPECIAL_VAR_SYMBOL
3797 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3798 debug_print_strings("word appended to argv", command->argv);
3801 #if ENABLE_HUSH_LOOPS
3802 if (ctx->ctx_res_w == RES_FOR) {
3803 if (word->has_quoted_part
3804 || !is_well_formed_var_name(command->argv[0], '\0')
3806 /* bash says just "not a valid identifier" */
3807 syntax_error("not a valid identifier in for");
3810 /* Force FOR to have just one word (variable name) */
3811 /* NB: basically, this makes hush see "for v in ..."
3812 * syntax as if it is "for v; in ...". FOR and IN become
3813 * two pipe structs in parse tree. */
3814 done_pipe(ctx, PIPE_SEQ);
3817 #if ENABLE_HUSH_CASE
3818 /* Force CASE to have just one word */
3819 if (ctx->ctx_res_w == RES_CASE) {
3820 done_pipe(ctx, PIPE_SEQ);
3824 o_reset_to_empty_unquoted(word);
3826 debug_printf_parse("done_word return 0\n");
3831 /* Peek ahead in the input to find out if we have a "&n" construct,
3832 * as in "2>&1", that represents duplicating a file descriptor.
3834 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3835 * REDIRFD_SYNTAX_ERR if syntax error,
3836 * REDIRFD_TO_FILE if no & was seen,
3837 * or the number found.
3840 #define parse_redir_right_fd(as_string, input) \
3841 parse_redir_right_fd(input)
3843 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3849 return REDIRFD_TO_FILE;
3851 ch = i_getch(input); /* get the & */
3852 nommu_addchr(as_string, ch);
3855 ch = i_getch(input);
3856 nommu_addchr(as_string, ch);
3857 return REDIRFD_CLOSE;
3861 while (ch != EOF && isdigit(ch)) {
3862 d = d*10 + (ch-'0');
3864 ch = i_getch(input);
3865 nommu_addchr(as_string, ch);
3870 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3872 bb_error_msg("ambiguous redirect");
3873 return REDIRFD_SYNTAX_ERR;
3876 /* Return code is 0 normal, 1 if a syntax error is detected
3878 static int parse_redirect(struct parse_context *ctx,
3881 struct in_str *input)
3883 struct command *command = ctx->command;
3884 struct redir_struct *redir;
3885 struct redir_struct **redirp;
3888 dup_num = REDIRFD_TO_FILE;
3889 if (style != REDIRECT_HEREDOC) {
3890 /* Check for a '>&1' type redirect */
3891 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3892 if (dup_num == REDIRFD_SYNTAX_ERR)
3895 int ch = i_peek(input);
3896 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3897 if (dup_num) { /* <<-... */
3898 ch = i_getch(input);
3899 nommu_addchr(&ctx->as_string, ch);
3904 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3905 int ch = i_peek(input);
3907 /* >|FILE redirect ("clobbering" >).
3908 * Since we do not support "set -o noclobber" yet,
3909 * >| and > are the same for now. Just eat |.
3911 ch = i_getch(input);
3912 nommu_addchr(&ctx->as_string, ch);
3916 /* Create a new redir_struct and append it to the linked list */
3917 redirp = &command->redirects;
3918 while ((redir = *redirp) != NULL) {
3919 redirp = &(redir->next);
3921 *redirp = redir = xzalloc(sizeof(*redir));
3922 /* redir->next = NULL; */
3923 /* redir->rd_filename = NULL; */
3924 redir->rd_type = style;
3925 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3927 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3928 redir_table[style].descrip);
3930 redir->rd_dup = dup_num;
3931 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3932 /* Erik had a check here that the file descriptor in question
3933 * is legit; I postpone that to "run time"
3934 * A "-" representation of "close me" shows up as a -3 here */
3935 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3936 redir->rd_fd, redir->rd_dup);
3938 #if 0 /* Instead we emit error message at run time */
3939 if (ctx->pending_redirect) {
3940 /* For example, "cmd > <file" */
3941 die_if_script("syntax error: %s", "invalid redirect");
3944 /* Set ctx->pending_redirect, so we know what to do at the
3945 * end of the next parsed word. */
3946 ctx->pending_redirect = redir;
3951 /* If a redirect is immediately preceded by a number, that number is
3952 * supposed to tell which file descriptor to redirect. This routine
3953 * looks for such preceding numbers. In an ideal world this routine
3954 * needs to handle all the following classes of redirects...
3955 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3956 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3957 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3958 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3960 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3962 * ... If n is quoted, the number shall not be recognized as part of
3963 * the redirection expression. For example:
3965 * writes the character 2 into file a"
3966 * We are getting it right by setting ->has_quoted_part on any \<char>
3968 * A -1 return means no valid number was found,
3969 * the caller should use the appropriate default for this redirection.
3971 static int redirect_opt_num(o_string *o)
3975 if (o->data == NULL)
3977 num = bb_strtou(o->data, NULL, 10);
3978 if (errno || num < 0)
3980 o_reset_to_empty_unquoted(o);
3985 #define fetch_till_str(as_string, input, word, skip_tabs) \
3986 fetch_till_str(input, word, skip_tabs)
3988 static char *fetch_till_str(o_string *as_string,
3989 struct in_str *input,
3993 o_string heredoc = NULL_O_STRING;
3995 int prev = 0; /* not \ */
4001 ch = i_getch(input);
4003 nommu_addchr(as_string, ch);
4004 if ((ch == '\n' || ch == EOF)
4005 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
4007 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4008 heredoc.data[past_EOL] = '\0';
4009 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4010 return heredoc.data;
4012 while (ch == '\n') {
4013 o_addchr(&heredoc, ch);
4016 past_EOL = heredoc.length;
4018 ch = i_getch(input);
4020 nommu_addchr(as_string, ch);
4021 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4025 o_free_unsafe(&heredoc);
4028 o_addchr(&heredoc, ch);
4029 nommu_addchr(as_string, ch);
4030 if (prev == '\\' && ch == '\\')
4031 /* Correctly handle foo\\<eol> (not a line cont.) */
4032 prev = 0; /* not \ */
4038 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4039 * and load them all. There should be exactly heredoc_cnt of them.
4041 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4043 struct pipe *pi = ctx->list_head;
4045 while (pi && heredoc_cnt) {
4047 struct command *cmd = pi->cmds;
4049 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4051 cmd->argv ? cmd->argv[0] : "NONE");
4052 for (i = 0; i < pi->num_cmds; i++) {
4053 struct redir_struct *redir = cmd->redirects;
4055 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4056 i, cmd->argv ? cmd->argv[0] : "NONE");
4058 if (redir->rd_type == REDIRECT_HEREDOC) {
4061 redir->rd_type = REDIRECT_HEREDOC2;
4062 /* redir->rd_dup is (ab)used to indicate <<- */
4063 p = fetch_till_str(&ctx->as_string, input,
4064 redir->rd_filename, redir->rd_dup);
4066 syntax_error("unexpected EOF in here document");
4069 free(redir->rd_filename);
4070 redir->rd_filename = p;
4073 redir = redir->next;
4080 /* Should be 0. If it isn't, it's a parse error */
4082 bb_error_msg_and_die("heredoc BUG 2");
4088 static int run_list(struct pipe *pi);
4090 #define parse_stream(pstring, input, end_trigger) \
4091 parse_stream(input, end_trigger)
4093 static struct pipe *parse_stream(char **pstring,
4094 struct in_str *input,
4098 #if !ENABLE_HUSH_FUNCTIONS
4099 #define parse_group(dest, ctx, input, ch) \
4100 parse_group(ctx, input, ch)
4102 static int parse_group(o_string *dest, struct parse_context *ctx,
4103 struct in_str *input, int ch)
4105 /* dest contains characters seen prior to ( or {.
4106 * Typically it's empty, but for function defs,
4107 * it contains function name (without '()'). */
4108 struct pipe *pipe_list;
4110 struct command *command = ctx->command;
4112 debug_printf_parse("parse_group entered\n");
4113 #if ENABLE_HUSH_FUNCTIONS
4114 if (ch == '(' && !dest->has_quoted_part) {
4116 if (done_word(dest, ctx))
4119 goto skip; /* (... */
4120 if (command->argv[1]) { /* word word ... (... */
4121 syntax_error_unexpected_ch('(');
4124 /* it is "word(..." or "word (..." */
4126 ch = i_getch(input);
4127 while (ch == ' ' || ch == '\t');
4129 syntax_error_unexpected_ch(ch);
4132 nommu_addchr(&ctx->as_string, ch);
4134 ch = i_getch(input);
4135 while (ch == ' ' || ch == '\t' || ch == '\n');
4137 syntax_error_unexpected_ch(ch);
4140 nommu_addchr(&ctx->as_string, ch);
4141 command->cmd_type = CMD_FUNCDEF;
4146 #if 0 /* Prevented by caller */
4147 if (command->argv /* word [word]{... */
4148 || dest->length /* word{... */
4149 || dest->has_quoted_part /* ""{... */
4152 debug_printf_parse("parse_group return 1: "
4153 "syntax error, groups and arglists don't mix\n");
4158 #if ENABLE_HUSH_FUNCTIONS
4164 command->cmd_type = CMD_SUBSHELL;
4166 /* bash does not allow "{echo...", requires whitespace */
4168 if (ch != ' ' && ch != '\t' && ch != '\n'
4169 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4171 syntax_error_unexpected_ch(ch);
4175 ch = i_getch(input);
4176 nommu_addchr(&ctx->as_string, ch);
4182 # define as_string NULL
4184 char *as_string = NULL;
4186 pipe_list = parse_stream(&as_string, input, endch);
4189 o_addstr(&ctx->as_string, as_string);
4191 /* empty ()/{} or parse error? */
4192 if (!pipe_list || pipe_list == ERR_PTR) {
4193 /* parse_stream already emitted error msg */
4196 debug_printf_parse("parse_group return 1: "
4197 "parse_stream returned %p\n", pipe_list);
4200 command->group = pipe_list;
4202 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4203 command->group_as_string = as_string;
4204 debug_printf_parse("end of group, remembering as:'%s'\n",
4205 command->group_as_string);
4209 debug_printf_parse("parse_group return 0\n");
4211 /* command remains "open", available for possible redirects */
4214 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4219 ch = i_getch(input);
4222 ch2 = i_peek(input);
4225 /* backslash+newline, skip it */
4230 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4238 ch2 = i_peek2(input);
4241 /* backslash+newline, skip it */
4247 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4248 /* Subroutines for copying $(...) and `...` things */
4249 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4251 static int add_till_single_quote(o_string *dest, struct in_str *input)
4254 int ch = i_getch(input);
4256 syntax_error_unterm_ch('\'');
4264 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4265 static int add_till_double_quote(o_string *dest, struct in_str *input)
4268 int ch = i_getch(input);
4270 syntax_error_unterm_ch('"');
4275 if (ch == '\\') { /* \x. Copy both chars. */
4277 ch = i_getch(input);
4281 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4286 //if (ch == '$') ...
4289 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4291 * "Within the backquoted style of command substitution, backslash
4292 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4293 * The search for the matching backquote shall be satisfied by the first
4294 * backquote found without a preceding backslash; during this search,
4295 * if a non-escaped backquote is encountered within a shell comment,
4296 * a here-document, an embedded command substitution of the $(command)
4297 * form, or a quoted string, undefined results occur. A single-quoted
4298 * or double-quoted string that begins, but does not end, within the
4299 * "`...`" sequence produces undefined results."
4301 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4303 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4306 int ch = i_getch(input);
4310 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4311 ch = i_getch(input);
4315 && (!in_dquote || ch != '"')
4317 o_addchr(dest, '\\');
4321 syntax_error_unterm_ch('`');
4327 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4328 * quoting and nested ()s.
4329 * "With the $(command) style of command substitution, all characters
4330 * following the open parenthesis to the matching closing parenthesis
4331 * constitute the command. Any valid shell script can be used for command,
4332 * except a script consisting solely of redirections which produces
4333 * unspecified results."
4335 * echo $(echo '(TEST)' BEST) (TEST) BEST
4336 * echo $(echo 'TEST)' BEST) TEST) BEST
4337 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4339 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4340 * can contain arbitrary constructs, just like $(cmd).
4341 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4342 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4344 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4345 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4348 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4349 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4350 char end_char2 = end_ch >> 8;
4352 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4355 ch = i_getch(input);
4357 syntax_error_unterm_ch(end_ch);
4361 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4367 /* we look for closing )) of $((EXPR)) */
4368 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4369 i_getch(input); /* eat second ')' */
4374 if (ch == '(' || ch == '{') {
4375 ch = (ch == '(' ? ')' : '}');
4376 if (!add_till_closing_bracket(dest, input, ch))
4382 if (!add_till_single_quote(dest, input))
4388 if (!add_till_double_quote(dest, input))
4394 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4400 /* \x. Copy verbatim. Important for \(, \) */
4401 ch = i_getch(input);
4403 syntax_error_unterm_ch(')');
4408 /* "backslash+newline", ignore both */
4409 o_delchr(dest); /* undo insertion of '\' */
4419 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4421 /* Return code: 0 for OK, 1 for syntax error */
4423 #define parse_dollar(as_string, dest, input, quote_mask) \
4424 parse_dollar(dest, input, quote_mask)
4425 #define as_string NULL
4427 static int parse_dollar(o_string *as_string,
4429 struct in_str *input, unsigned char quote_mask)
4431 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4433 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4435 ch = i_getch(input);
4436 nommu_addchr(as_string, ch);
4438 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4440 debug_printf_parse(": '%c'\n", ch);
4441 o_addchr(dest, ch | quote_mask);
4443 ch = i_peek_and_eat_bkslash_nl(input);
4444 if (!isalnum(ch) && ch != '_') {
4445 /* End of variable name reached */
4448 ch = i_getch(input);
4449 nommu_addchr(as_string, ch);
4451 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4452 } else if (isdigit(ch)) {
4454 ch = i_getch(input);
4455 nommu_addchr(as_string, ch);
4456 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4457 debug_printf_parse(": '%c'\n", ch);
4458 o_addchr(dest, ch | quote_mask);
4459 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4460 } else switch (ch) {
4462 case '!': /* last bg pid */
4463 case '?': /* last exit code */
4464 case '#': /* number of args */
4465 case '*': /* args */
4466 case '@': /* args */
4467 goto make_one_char_var;
4469 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4471 ch = i_getch(input); /* eat '{' */
4472 nommu_addchr(as_string, ch);
4474 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4475 /* It should be ${?}, or ${#var},
4476 * or even ${?+subst} - operator acting on a special variable,
4477 * or the beginning of variable name.
4480 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4483 syntax_error_unterm_str("${name}");
4484 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4487 nommu_addchr(as_string, ch);
4490 /* It's possible to just call add_till_closing_bracket() at this point.
4491 * However, this regresses some of our testsuite cases
4492 * which check invalid constructs like ${%}.
4493 * Oh well... let's check that the var name part is fine... */
4499 debug_printf_parse(": '%c'\n", ch);
4501 ch = i_getch(input);
4502 nommu_addchr(as_string, ch);
4506 if (!isalnum(ch) && ch != '_') {
4508 unsigned char last_ch;
4509 /* handle parameter expansions
4510 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4512 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4513 goto bad_dollar_syntax;
4515 /* Eat everything until closing '}' (or ':') */
4519 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4521 /* It's ${var:N[:M]} thing */
4522 end_ch = '}' * 0x100 + ':';
4524 if (BASH_PATTERN_SUBST
4527 /* It's ${var/[/]pattern[/repl]} thing */
4528 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4530 nommu_addchr(as_string, '/');
4533 end_ch = '}' * 0x100 + '/';
4539 #if ENABLE_HUSH_DOLLAR_OPS
4540 last_ch = add_till_closing_bracket(dest, input, end_ch);
4541 if (last_ch == 0) /* error? */
4544 #error Simple code to only allow ${var} is not implemented
4547 o_addstr(as_string, dest->data + pos);
4548 o_addchr(as_string, last_ch);
4551 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4552 && (end_ch & 0xff00)
4554 /* close the first block: */
4555 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4556 /* while parsing N from ${var:N[:M]}
4557 * or pattern from ${var/[/]pattern[/repl]} */
4558 if ((end_ch & 0xff) == last_ch) {
4559 /* got ':' or '/'- parse the rest */
4564 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4565 /* it's ${var:N} - emulate :999999999 */
4566 o_addstr(dest, "999999999");
4567 } /* else: it's ${var/[/]pattern} */
4572 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4575 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4579 ch = i_getch(input);
4580 nommu_addchr(as_string, ch);
4581 # if ENABLE_FEATURE_SH_MATH
4582 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4583 ch = i_getch(input);
4584 nommu_addchr(as_string, ch);
4585 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4586 o_addchr(dest, /*quote_mask |*/ '+');
4589 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4590 return 0; /* error */
4592 o_addstr(as_string, dest->data + pos);
4593 o_addchr(as_string, ')');
4594 o_addchr(as_string, ')');
4596 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4600 # if ENABLE_HUSH_TICK
4601 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4602 o_addchr(dest, quote_mask | '`');
4605 if (!add_till_closing_bracket(dest, input, ')'))
4606 return 0; /* error */
4608 o_addstr(as_string, dest->data + pos);
4609 o_addchr(as_string, ')');
4611 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4617 ch = i_getch(input);
4618 nommu_addchr(as_string, ch);
4619 ch = i_peek_and_eat_bkslash_nl(input);
4620 if (isalnum(ch)) { /* it's $_name or $_123 */
4625 /* TODO: $_ and $-: */
4626 /* $_ Shell or shell script name; or last argument of last command
4627 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4628 * but in command's env, set to full pathname used to invoke it */
4629 /* $- Option flags set by set builtin or shell options (-i etc) */
4631 o_addQchr(dest, '$');
4633 debug_printf_parse("parse_dollar return 1 (ok)\n");
4639 # if BASH_PATTERN_SUBST
4640 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4641 encode_string(dest, input, dquote_end, process_bkslash)
4643 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4644 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4645 encode_string(dest, input, dquote_end)
4647 #define as_string NULL
4651 # if BASH_PATTERN_SUBST
4652 /* all parameters are needed, no macro tricks */
4654 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4655 encode_string(as_string, dest, input, dquote_end)
4658 static int encode_string(o_string *as_string,
4660 struct in_str *input,
4662 int process_bkslash)
4664 #if !BASH_PATTERN_SUBST
4665 const int process_bkslash = 1;
4671 ch = i_getch(input);
4673 nommu_addchr(as_string, ch);
4674 if (ch == dquote_end) { /* may be only '"' or EOF */
4675 debug_printf_parse("encode_string return 1 (ok)\n");
4678 /* note: can't move it above ch == dquote_end check! */
4680 syntax_error_unterm_ch('"');
4681 return 0; /* error */
4685 next = i_peek(input);
4687 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4688 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4689 if (process_bkslash && ch == '\\') {
4691 syntax_error("\\<eof>");
4695 * "The backslash retains its special meaning [in "..."]
4696 * only when followed by one of the following characters:
4697 * $, `, ", \, or <newline>. A double quote may be quoted
4698 * within double quotes by preceding it with a backslash."
4699 * NB: in (unquoted) heredoc, above does not apply to ",
4700 * therefore we check for it by "next == dquote_end" cond.
4702 if (next == dquote_end || strchr("$`\\\n", next)) {
4703 ch = i_getch(input); /* eat next */
4705 goto again; /* skip \<newline> */
4706 } /* else: ch remains == '\\', and we double it below: */
4707 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4708 nommu_addchr(as_string, ch);
4712 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4713 debug_printf_parse("encode_string return 0: "
4714 "parse_dollar returned 0 (error)\n");
4719 #if ENABLE_HUSH_TICK
4721 //unsigned pos = dest->length;
4722 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4723 o_addchr(dest, 0x80 | '`');
4724 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4725 return 0; /* error */
4726 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4727 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4731 o_addQchr(dest, ch);
4737 * Scan input until EOF or end_trigger char.
4738 * Return a list of pipes to execute, or NULL on EOF
4739 * or if end_trigger character is met.
4740 * On syntax error, exit if shell is not interactive,
4741 * reset parsing machinery and start parsing anew,
4742 * or return ERR_PTR.
4744 static struct pipe *parse_stream(char **pstring,
4745 struct in_str *input,
4748 struct parse_context ctx;
4749 o_string dest = NULL_O_STRING;
4752 /* Single-quote triggers a bypass of the main loop until its mate is
4753 * found. When recursing, quote state is passed in via dest->o_expflags.
4755 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4756 end_trigger ? end_trigger : 'X');
4759 /* If very first arg is "" or '', dest.data may end up NULL.
4760 * Preventing this: */
4761 o_addchr(&dest, '\0');
4764 /* We used to separate words on $IFS here. This was wrong.
4765 * $IFS is used only for word splitting when $var is expanded,
4766 * here we should use blank chars as separators, not $IFS
4769 if (MAYBE_ASSIGNMENT != 0)
4770 dest.o_assignment = MAYBE_ASSIGNMENT;
4771 initialize_context(&ctx);
4774 const char *is_blank;
4775 const char *is_special;
4779 redir_type redir_style;
4781 ch = i_getch(input);
4782 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4783 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4788 syntax_error_unterm_str("here document");
4791 if (end_trigger == ')') {
4792 syntax_error_unterm_ch('(');
4795 if (end_trigger == '}') {
4796 syntax_error_unterm_ch('{');
4800 if (done_word(&dest, &ctx)) {
4804 done_pipe(&ctx, PIPE_SEQ);
4806 /* If we got nothing... */
4807 /* (this makes bare "&" cmd a no-op.
4808 * bash says: "syntax error near unexpected token '&'") */
4809 if (pi->num_cmds == 0
4810 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4816 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4818 *pstring = ctx.as_string.data;
4820 o_free_unsafe(&ctx.as_string);
4823 debug_printf_parse("parse_stream return %p\n", pi);
4826 nommu_addchr(&ctx.as_string, ch);
4830 next = i_peek(input);
4832 is_special = "{}<>;&|()#'" /* special outside of "str" */
4833 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4834 /* Are { and } special here? */
4835 if (ctx.command->argv /* word [word]{... - non-special */
4836 || dest.length /* word{... - non-special */
4837 || dest.has_quoted_part /* ""{... - non-special */
4838 || (next != ';' /* }; - special */
4839 && next != ')' /* }) - special */
4840 && next != '(' /* {( - special */
4841 && next != '&' /* }& and }&& ... - special */
4842 && next != '|' /* }|| ... - special */
4843 && !strchr(defifs, next) /* {word - non-special */
4846 /* They are not special, skip "{}" */
4849 is_special = strchr(is_special, ch);
4850 is_blank = strchr(defifs, ch);
4852 if (!is_special && !is_blank) { /* ordinary char */
4854 o_addQchr(&dest, ch);
4855 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4856 || dest.o_assignment == WORD_IS_KEYWORD)
4858 && is_well_formed_var_name(dest.data, '=')
4860 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4861 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4867 if (done_word(&dest, &ctx)) {
4871 /* Is this a case when newline is simply ignored?
4873 * "cmd | <newline> cmd ..."
4874 * "case ... in <newline> word) ..."
4876 if (IS_NULL_CMD(ctx.command)
4877 && dest.length == 0 && !dest.has_quoted_part
4879 /* This newline can be ignored. But...
4880 * Without check #1, interactive shell
4881 * ignores even bare <newline>,
4882 * and shows the continuation prompt:
4883 * ps1_prompt$ <enter>
4884 * ps2> _ <=== wrong, should be ps1
4885 * Without check #2, "cmd & <newline>"
4886 * is similarly mistreated.
4887 * (BTW, this makes "cmd & cmd"
4888 * and "cmd && cmd" non-orthogonal.
4889 * Really, ask yourself, why
4890 * "cmd && <newline>" doesn't start
4891 * cmd but waits for more input?
4892 * The only reason is that it might be
4893 * a "cmd1 && <nl> cmd2 &" construct,
4894 * cmd1 may need to run in BG).
4896 struct pipe *pi = ctx.list_head;
4897 if (pi->num_cmds != 0 /* check #1 */
4898 && pi->followup != PIPE_BG /* check #2 */
4903 /* Treat newline as a command separator. */
4904 done_pipe(&ctx, PIPE_SEQ);
4905 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4907 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4912 dest.o_assignment = MAYBE_ASSIGNMENT;
4913 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4915 /* note: if (is_blank) continue;
4916 * will still trigger for us */
4920 /* "cmd}" or "cmd }..." without semicolon or &:
4921 * } is an ordinary char in this case, even inside { cmd; }
4922 * Pathological example: { ""}; } should exec "}" cmd
4925 if (dest.length != 0 /* word} */
4926 || dest.has_quoted_part /* ""} */
4930 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4931 /* Generally, there should be semicolon: "cmd; }"
4932 * However, bash allows to omit it if "cmd" is
4933 * a group. Examples:
4936 * { echo 0 >&2 | { echo 1; } }
4937 * { while false; do :; done }
4938 * { case a in b) ;; esac }
4940 if (ctx.command->group)
4944 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4945 /* Can't be an end of {cmd}, skip the check */
4946 goto skip_end_trigger;
4947 /* else: } does terminate a group */
4950 if (end_trigger && end_trigger == ch
4951 && (ch != ';' || heredoc_cnt == 0)
4952 #if ENABLE_HUSH_CASE
4954 || ctx.ctx_res_w != RES_MATCH
4955 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4960 /* This is technically valid:
4961 * { cat <<HERE; }; echo Ok
4965 * but we don't support this.
4966 * We require heredoc to be in enclosing {}/(),
4969 syntax_error_unterm_str("here document");
4972 if (done_word(&dest, &ctx)) {
4975 done_pipe(&ctx, PIPE_SEQ);
4976 dest.o_assignment = MAYBE_ASSIGNMENT;
4977 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4978 /* Do we sit outside of any if's, loops or case's? */
4980 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4984 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4986 *pstring = ctx.as_string.data;
4988 o_free_unsafe(&ctx.as_string);
4991 debug_printf_parse("parse_stream return %p: "
4992 "end_trigger char found\n",
4994 return ctx.list_head;
5001 /* Catch <, > before deciding whether this word is
5002 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5005 redir_fd = redirect_opt_num(&dest);
5006 if (done_word(&dest, &ctx)) {
5009 redir_style = REDIRECT_OVERWRITE;
5011 redir_style = REDIRECT_APPEND;
5012 ch = i_getch(input);
5013 nommu_addchr(&ctx.as_string, ch);
5016 else if (next == '(') {
5017 syntax_error(">(process) not supported");
5021 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5023 continue; /* back to top of while (1) */
5025 redir_fd = redirect_opt_num(&dest);
5026 if (done_word(&dest, &ctx)) {
5029 redir_style = REDIRECT_INPUT;
5031 redir_style = REDIRECT_HEREDOC;
5033 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5034 ch = i_getch(input);
5035 nommu_addchr(&ctx.as_string, ch);
5036 } else if (next == '>') {
5037 redir_style = REDIRECT_IO;
5038 ch = i_getch(input);
5039 nommu_addchr(&ctx.as_string, ch);
5042 else if (next == '(') {
5043 syntax_error("<(process) not supported");
5047 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5049 continue; /* back to top of while (1) */
5051 if (dest.length == 0 && !dest.has_quoted_part) {
5052 /* skip "#comment" */
5055 if (ch == EOF || ch == '\n')
5058 /* note: we do not add it to &ctx.as_string */
5060 nommu_addchr(&ctx.as_string, '\n');
5061 continue; /* back to top of while (1) */
5066 /* It's "\<newline>" */
5068 /* Remove trailing '\' from ctx.as_string */
5069 ctx.as_string.data[--ctx.as_string.length] = '\0';
5071 ch = i_getch(input); /* eat it */
5072 continue; /* back to top of while (1) */
5077 if (dest.o_assignment == MAYBE_ASSIGNMENT
5078 /* check that we are not in word in "a=1 2>word b=1": */
5079 && !ctx.pending_redirect
5081 /* ch is a special char and thus this word
5082 * cannot be an assignment */
5083 dest.o_assignment = NOT_ASSIGNMENT;
5084 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5087 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5090 case '#': /* non-comment #: "echo a#b" etc */
5091 o_addQchr(&dest, ch);
5095 syntax_error("\\<eof>");
5098 ch = i_getch(input);
5099 /* note: ch != '\n' (that case does not reach this place) */
5100 o_addchr(&dest, '\\');
5101 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5102 o_addchr(&dest, ch);
5103 nommu_addchr(&ctx.as_string, ch);
5104 /* Example: echo Hello \2>file
5105 * we need to know that word 2 is quoted */
5106 dest.has_quoted_part = 1;
5109 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5110 debug_printf_parse("parse_stream parse error: "
5111 "parse_dollar returned 0 (error)\n");
5116 dest.has_quoted_part = 1;
5117 if (next == '\'' && !ctx.pending_redirect) {
5118 insert_empty_quoted_str_marker:
5119 nommu_addchr(&ctx.as_string, next);
5120 i_getch(input); /* eat second ' */
5121 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5122 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5125 ch = i_getch(input);
5127 syntax_error_unterm_ch('\'');
5130 nommu_addchr(&ctx.as_string, ch);
5133 o_addqchr(&dest, ch);
5138 dest.has_quoted_part = 1;
5139 if (next == '"' && !ctx.pending_redirect)
5140 goto insert_empty_quoted_str_marker;
5141 if (dest.o_assignment == NOT_ASSIGNMENT)
5142 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5143 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5145 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5147 #if ENABLE_HUSH_TICK
5149 USE_FOR_NOMMU(unsigned pos;)
5151 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5152 o_addchr(&dest, '`');
5153 USE_FOR_NOMMU(pos = dest.length;)
5154 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5157 o_addstr(&ctx.as_string, dest.data + pos);
5158 o_addchr(&ctx.as_string, '`');
5160 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5161 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5166 #if ENABLE_HUSH_CASE
5169 if (done_word(&dest, &ctx)) {
5172 done_pipe(&ctx, PIPE_SEQ);
5173 #if ENABLE_HUSH_CASE
5174 /* Eat multiple semicolons, detect
5175 * whether it means something special */
5180 ch = i_getch(input);
5181 nommu_addchr(&ctx.as_string, ch);
5182 if (ctx.ctx_res_w == RES_CASE_BODY) {
5183 ctx.ctx_dsemicolon = 1;
5184 ctx.ctx_res_w = RES_MATCH;
5190 /* We just finished a cmd. New one may start
5191 * with an assignment */
5192 dest.o_assignment = MAYBE_ASSIGNMENT;
5193 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5196 if (done_word(&dest, &ctx)) {
5200 ch = i_getch(input);
5201 nommu_addchr(&ctx.as_string, ch);
5202 done_pipe(&ctx, PIPE_AND);
5204 done_pipe(&ctx, PIPE_BG);
5208 if (done_word(&dest, &ctx)) {
5211 #if ENABLE_HUSH_CASE
5212 if (ctx.ctx_res_w == RES_MATCH)
5213 break; /* we are in case's "word | word)" */
5215 if (next == '|') { /* || */
5216 ch = i_getch(input);
5217 nommu_addchr(&ctx.as_string, ch);
5218 done_pipe(&ctx, PIPE_OR);
5220 /* we could pick up a file descriptor choice here
5221 * with redirect_opt_num(), but bash doesn't do it.
5222 * "echo foo 2| cat" yields "foo 2". */
5227 #if ENABLE_HUSH_CASE
5228 /* "case... in [(]word)..." - skip '(' */
5229 if (ctx.ctx_res_w == RES_MATCH
5230 && ctx.command->argv == NULL /* not (word|(... */
5231 && dest.length == 0 /* not word(... */
5232 && dest.has_quoted_part == 0 /* not ""(... */
5238 if (parse_group(&dest, &ctx, input, ch) != 0) {
5243 #if ENABLE_HUSH_CASE
5244 if (ctx.ctx_res_w == RES_MATCH)
5248 /* proper use of this character is caught by end_trigger:
5249 * if we see {, we call parse_group(..., end_trigger='}')
5250 * and it will match } earlier (not here). */
5251 syntax_error_unexpected_ch(ch);
5252 G.last_exitcode = 2;
5256 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5261 G.last_exitcode = 1;
5264 struct parse_context *pctx;
5265 IF_HAS_KEYWORDS(struct parse_context *p2;)
5267 /* Clean up allocated tree.
5268 * Sample for finding leaks on syntax error recovery path.
5269 * Run it from interactive shell, watch pmap `pidof hush`.
5270 * while if false; then false; fi; do break; fi
5271 * Samples to catch leaks at execution:
5272 * while if (true | { true;}); then echo ok; fi; do break; done
5273 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5277 /* Update pipe/command counts,
5278 * otherwise freeing may miss some */
5279 done_pipe(pctx, PIPE_SEQ);
5280 debug_printf_clean("freeing list %p from ctx %p\n",
5281 pctx->list_head, pctx);
5282 debug_print_tree(pctx->list_head, 0);
5283 free_pipe_list(pctx->list_head);
5284 debug_printf_clean("freed list %p\n", pctx->list_head);
5286 o_free_unsafe(&pctx->as_string);
5288 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5292 IF_HAS_KEYWORDS(pctx = p2;)
5293 } while (HAS_KEYWORDS && pctx);
5306 /*** Execution routines ***/
5308 /* Expansion can recurse, need forward decls: */
5309 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5310 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5311 #define expand_string_to_string(str, do_unbackslash) \
5312 expand_string_to_string(str)
5314 static char *expand_string_to_string(const char *str, int do_unbackslash);
5315 #if ENABLE_HUSH_TICK
5316 static int process_command_subs(o_string *dest, const char *s);
5319 /* expand_strvec_to_strvec() takes a list of strings, expands
5320 * all variable references within and returns a pointer to
5321 * a list of expanded strings, possibly with larger number
5322 * of strings. (Think VAR="a b"; echo $VAR).
5323 * This new list is allocated as a single malloc block.
5324 * NULL-terminated list of char* pointers is at the beginning of it,
5325 * followed by strings themselves.
5326 * Caller can deallocate entire list by single free(list). */
5328 /* A horde of its helpers come first: */
5330 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5332 while (--len >= 0) {
5335 #if ENABLE_HUSH_BRACE_EXPANSION
5336 if (c == '{' || c == '}') {
5337 /* { -> \{, } -> \} */
5339 /* And now we want to add { or } and continue:
5342 * luckily, just falling through achieves this.
5348 /* \z -> \\\z; \<eol> -> \\<eol> */
5353 o_addchr(o, *str++);
5359 /* Store given string, finalizing the word and starting new one whenever
5360 * we encounter IFS char(s). This is used for expanding variable values.
5361 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5362 * Return in *ended_with_ifs:
5363 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5365 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5367 int last_is_ifs = 0;
5372 if (!*str) /* EOL - do not finalize word */
5374 word_len = strcspn(str, G.ifs);
5376 /* We have WORD_LEN leading non-IFS chars */
5377 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5378 o_addblock(output, str, word_len);
5380 /* Protect backslashes against globbing up :)
5381 * Example: "v='\*'; echo b$v" prints "b\*"
5382 * (and does not try to glob on "*")
5384 o_addblock_duplicate_backslash(output, str, word_len);
5385 /*/ Why can't we do it easier? */
5386 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5387 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5391 if (!*str) /* EOL - do not finalize word */
5395 /* We know str here points to at least one IFS char */
5397 str += strspn(str, G.ifs); /* skip IFS chars */
5398 if (!*str) /* EOL - do not finalize word */
5401 /* Start new word... but not always! */
5402 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5403 if (output->has_quoted_part
5404 /* Case "v=' a'; echo $v":
5405 * here nothing precedes the space in $v expansion,
5406 * therefore we should not finish the word
5407 * (IOW: if there *is* word to finalize, only then do it):
5409 || (n > 0 && output->data[output->length - 1])
5411 o_addchr(output, '\0');
5412 debug_print_list("expand_on_ifs", output, n);
5413 n = o_save_ptr(output, n);
5418 *ended_with_ifs = last_is_ifs;
5419 debug_print_list("expand_on_ifs[1]", output, n);
5423 /* Helper to expand $((...)) and heredoc body. These act as if
5424 * they are in double quotes, with the exception that they are not :).
5425 * Just the rules are similar: "expand only $var and `cmd`"
5427 * Returns malloced string.
5428 * As an optimization, we return NULL if expansion is not needed.
5430 #if !BASH_PATTERN_SUBST
5431 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5432 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5433 encode_then_expand_string(str)
5435 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5437 #if !BASH_PATTERN_SUBST
5438 const int do_unbackslash = 1;
5441 struct in_str input;
5442 o_string dest = NULL_O_STRING;
5444 if (!strchr(str, '$')
5445 && !strchr(str, '\\')
5446 #if ENABLE_HUSH_TICK
5447 && !strchr(str, '`')
5453 /* We need to expand. Example:
5454 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5456 setup_string_in_str(&input, str);
5457 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5458 //TODO: error check (encode_string returns 0 on error)?
5459 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5460 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5461 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5462 o_free_unsafe(&dest);
5466 #if ENABLE_FEATURE_SH_MATH
5467 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5469 arith_state_t math_state;
5473 math_state.lookupvar = get_local_var_value;
5474 math_state.setvar = set_local_var_from_halves;
5475 //math_state.endofname = endofname;
5476 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5477 res = arith(&math_state, exp_str ? exp_str : arg);
5480 *errmsg_p = math_state.errmsg;
5481 if (math_state.errmsg)
5482 die_if_script(math_state.errmsg);
5487 #if BASH_PATTERN_SUBST
5488 /* ${var/[/]pattern[/repl]} helpers */
5489 static char *strstr_pattern(char *val, const char *pattern, int *size)
5492 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5493 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5500 /* Optimization: if "*pat" did not match the start of "string",
5501 * we know that "tring", "ring" etc will not match too:
5503 if (pattern[0] == '*')
5508 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5510 char *result = NULL;
5511 unsigned res_len = 0;
5512 unsigned repl_len = strlen(repl);
5516 char *s = strstr_pattern(val, pattern, &size);
5520 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5521 strcpy(mempcpy(result + res_len, val, s - val), repl);
5522 res_len += (s - val) + repl_len;
5523 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5529 if (*val && result) {
5530 result = xrealloc(result, res_len + strlen(val) + 1);
5531 strcpy(result + res_len, val);
5532 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5534 debug_printf_varexp("result:'%s'\n", result);
5537 #endif /* BASH_PATTERN_SUBST */
5540 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5542 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5544 const char *val = NULL;
5545 char *to_be_freed = NULL;
5550 char exp_save = exp_save; /* for compiler */
5551 char *exp_saveptr; /* points to expansion operator */
5552 char *exp_word = exp_word; /* for compiler */
5555 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5557 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5559 first_char = arg[0] = arg0 & 0x7f;
5562 if (first_char == '#' /* ${#... */
5563 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5565 /* It must be length operator: ${#var} */
5569 /* Maybe handle parameter expansion */
5570 if (exp_saveptr /* if 2nd char is one of expansion operators */
5571 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5573 /* ${?:0}, ${#[:]%0} etc */
5574 exp_saveptr = var + 1;
5576 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5577 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5579 exp_op = exp_save = *exp_saveptr;
5581 exp_word = exp_saveptr + 1;
5582 if (exp_op == ':') {
5583 exp_op = *exp_word++;
5584 //TODO: try ${var:} and ${var:bogus} in non-bash config
5586 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5588 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5593 *exp_saveptr = '\0';
5594 } /* else: it's not an expansion op, but bare ${var} */
5597 /* Look up the variable in question */
5598 if (isdigit(var[0])) {
5599 /* parse_dollar should have vetted var for us */
5600 int n = xatoi_positive(var);
5601 if (n < G.global_argc)
5602 val = G.global_argv[n];
5603 /* else val remains NULL: $N with too big N */
5607 val = utoa(G.root_pid);
5609 case '!': /* bg pid */
5610 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5612 case '?': /* exitcode */
5613 val = utoa(G.last_exitcode);
5615 case '#': /* argc */
5616 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5619 val = get_local_var_value(var);
5623 /* Handle any expansions */
5624 if (exp_op == 'L') {
5625 reinit_unicode_for_hush();
5626 debug_printf_expand("expand: length(%s)=", val);
5627 val = utoa(val ? unicode_strlen(val) : 0);
5628 debug_printf_expand("%s\n", val);
5629 } else if (exp_op) {
5630 if (exp_op == '%' || exp_op == '#') {
5631 /* Standard-mandated substring removal ops:
5632 * ${parameter%word} - remove smallest suffix pattern
5633 * ${parameter%%word} - remove largest suffix pattern
5634 * ${parameter#word} - remove smallest prefix pattern
5635 * ${parameter##word} - remove largest prefix pattern
5637 * Word is expanded to produce a glob pattern.
5638 * Then var's value is matched to it and matching part removed.
5640 if (val && val[0]) {
5644 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5645 if (exp_op == *exp_word) /* ## or %% */
5647 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5649 exp_word = exp_exp_word;
5650 /* HACK ALERT. We depend here on the fact that
5651 * G.global_argv and results of utoa and get_local_var_value
5652 * are actually in writable memory:
5653 * scan_and_match momentarily stores NULs there. */
5655 loc = scan_and_match(t, exp_word, scan_flags);
5656 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5657 // exp_op, t, exp_word, loc);
5659 if (loc) { /* match was found */
5660 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5661 val = loc; /* take right part */
5663 val = to_be_freed = xstrndup(val, loc - val); /* left */
5667 #if BASH_PATTERN_SUBST
5668 else if (exp_op == '/' || exp_op == '\\') {
5669 /* It's ${var/[/]pattern[/repl]} thing.
5670 * Note that in encoded form it has TWO parts:
5671 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5672 * and if // is used, it is encoded as \:
5673 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5675 /* Empty variable always gives nothing: */
5676 // "v=''; echo ${v/*/w}" prints "", not "w"
5677 if (val && val[0]) {
5678 /* pattern uses non-standard expansion.
5679 * repl should be unbackslashed and globbed
5680 * by the usual expansion rules:
5682 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5683 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5684 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5685 * v='a bz'; echo ${v/a*z/\z} prints "z"
5686 * (note that a*z _pattern_ is never globbed!)
5688 char *pattern, *repl, *t;
5689 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5691 pattern = xstrdup(exp_word);
5692 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5693 *p++ = SPECIAL_VAR_SYMBOL;
5695 p = strchr(p, SPECIAL_VAR_SYMBOL);
5697 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5698 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5699 /* HACK ALERT. We depend here on the fact that
5700 * G.global_argv and results of utoa and get_local_var_value
5701 * are actually in writable memory:
5702 * replace_pattern momentarily stores NULs there. */
5704 to_be_freed = replace_pattern(t,
5706 (repl ? repl : exp_word),
5708 if (to_be_freed) /* at least one replace happened */
5714 #endif /* BASH_PATTERN_SUBST */
5715 else if (exp_op == ':') {
5716 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5717 /* It's ${var:N[:M]} bashism.
5718 * Note that in encoded form it has TWO parts:
5719 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5724 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5727 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5728 *p++ = SPECIAL_VAR_SYMBOL;
5730 p = strchr(p, SPECIAL_VAR_SYMBOL);
5732 len = expand_and_evaluate_arith(exp_word, &errmsg);
5735 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5737 /* negative beg counts from the end */
5738 beg = (arith_t)strlen(val) + beg;
5739 if (beg < 0) /* ${v: -999999} is "" */
5742 debug_printf_varexp("from val:'%s'\n", val);
5744 /* in bash, len=-n means strlen()-n */
5745 len = (arith_t)strlen(val) - beg + len;
5746 if (len < 0) /* bash compat */
5747 die_if_script("%s: substring expression < 0", var);
5749 if (len <= 0 || !val || beg >= strlen(val)) {
5753 /* Paranoia. What if user entered 9999999999999
5754 * which fits in arith_t but not int? */
5757 val = to_be_freed = xstrndup(val + beg, len);
5759 debug_printf_varexp("val:'%s'\n", val);
5760 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5761 die_if_script("malformed ${%s:...}", var);
5764 } else { /* one of "-=+?" */
5765 /* Standard-mandated substitution ops:
5766 * ${var?word} - indicate error if unset
5767 * If var is unset, word (or a message indicating it is unset
5768 * if word is null) is written to standard error
5769 * and the shell exits with a non-zero exit status.
5770 * Otherwise, the value of var is substituted.
5771 * ${var-word} - use default value
5772 * If var is unset, word is substituted.
5773 * ${var=word} - assign and use default value
5774 * If var is unset, word is assigned to var.
5775 * In all cases, final value of var is substituted.
5776 * ${var+word} - use alternative value
5777 * If var is unset, null is substituted.
5778 * Otherwise, word is substituted.
5780 * Word is subjected to tilde expansion, parameter expansion,
5781 * command substitution, and arithmetic expansion.
5782 * If word is not needed, it is not expanded.
5784 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5785 * but also treat null var as if it is unset.
5787 int use_word = (!val || ((exp_save == ':') && !val[0]));
5789 use_word = !use_word;
5790 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5791 (exp_save == ':') ? "true" : "false", use_word);
5793 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5795 exp_word = to_be_freed;
5796 if (exp_op == '?') {
5797 /* mimic bash message */
5798 die_if_script("%s: %s",
5800 exp_word[0] ? exp_word : "parameter null or not set"
5802 //TODO: how interactive bash aborts expansion mid-command?
5807 if (exp_op == '=') {
5808 /* ${var=[word]} or ${var:=[word]} */
5809 if (isdigit(var[0]) || var[0] == '#') {
5810 /* mimic bash message */
5811 die_if_script("$%s: cannot assign in this way", var);
5814 char *new_var = xasprintf("%s=%s", var, val);
5815 set_local_var(new_var, /*flag:*/ 0);
5819 } /* one of "-=+?" */
5821 *exp_saveptr = exp_save;
5827 *to_be_freed_pp = to_be_freed;
5831 /* Expand all variable references in given string, adding words to list[]
5832 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5833 * to be filled). This routine is extremely tricky: has to deal with
5834 * variables/parameters with whitespace, $* and $@, and constructs like
5835 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5836 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5838 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5839 * expansion of right-hand side of assignment == 1-element expand.
5841 char cant_be_null = 0; /* only bit 0x80 matters */
5842 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5845 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5846 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5847 debug_print_list("expand_vars_to_list", output, n);
5848 n = o_save_ptr(output, n);
5849 debug_print_list("expand_vars_to_list[0]", output, n);
5851 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5853 char *to_be_freed = NULL;
5854 const char *val = NULL;
5855 #if ENABLE_HUSH_TICK
5856 o_string subst_result = NULL_O_STRING;
5858 #if ENABLE_FEATURE_SH_MATH
5859 char arith_buf[sizeof(arith_t)*3 + 2];
5863 o_addchr(output, '\0');
5864 n = o_save_ptr(output, n);
5868 o_addblock(output, arg, p - arg);
5869 debug_print_list("expand_vars_to_list[1]", output, n);
5871 p = strchr(p, SPECIAL_VAR_SYMBOL);
5873 /* Fetch special var name (if it is indeed one of them)
5874 * and quote bit, force the bit on if singleword expansion -
5875 * important for not getting v=$@ expand to many words. */
5876 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5878 /* Is this variable quoted and thus expansion can't be null?
5879 * "$@" is special. Even if quoted, it can still
5880 * expand to nothing (not even an empty string),
5881 * thus it is excluded. */
5882 if ((first_ch & 0x7f) != '@')
5883 cant_be_null |= first_ch;
5885 switch (first_ch & 0x7f) {
5886 /* Highest bit in first_ch indicates that var is double-quoted */
5890 if (!G.global_argv[1])
5893 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5894 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5895 while (G.global_argv[i]) {
5896 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5897 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5898 if (G.global_argv[i++][0] && G.global_argv[i]) {
5899 /* this argv[] is not empty and not last:
5900 * put terminating NUL, start new word */
5901 o_addchr(output, '\0');
5902 debug_print_list("expand_vars_to_list[2]", output, n);
5903 n = o_save_ptr(output, n);
5904 debug_print_list("expand_vars_to_list[3]", output, n);
5908 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5909 * and in this case should treat it like '$*' - see 'else...' below */
5910 if (first_ch == ('@'|0x80) /* quoted $@ */
5911 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5914 o_addQstr(output, G.global_argv[i]);
5915 if (++i >= G.global_argc)
5917 o_addchr(output, '\0');
5918 debug_print_list("expand_vars_to_list[4]", output, n);
5919 n = o_save_ptr(output, n);
5921 } else { /* quoted $* (or v="$@" case): add as one word */
5923 o_addQstr(output, G.global_argv[i]);
5924 if (!G.global_argv[++i])
5927 o_addchr(output, G.ifs[0]);
5929 output->has_quoted_part = 1;
5933 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5934 /* "Empty variable", used to make "" etc to not disappear */
5935 output->has_quoted_part = 1;
5937 cant_be_null = 0x80;
5939 #if ENABLE_HUSH_TICK
5940 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5941 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5943 /* Can't just stuff it into output o_string,
5944 * expanded result may need to be globbed
5946 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5947 G.last_exitcode = process_command_subs(&subst_result, arg);
5948 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5949 val = subst_result.data;
5952 #if ENABLE_FEATURE_SH_MATH
5953 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5956 arg++; /* skip '+' */
5957 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5958 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5959 res = expand_and_evaluate_arith(arg, NULL);
5960 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5961 sprintf(arith_buf, ARITH_FMT, res);
5967 val = expand_one_var(&to_be_freed, arg, &p);
5968 IF_HUSH_TICK(store_val:)
5969 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5970 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5971 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5972 if (val && val[0]) {
5973 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5976 } else { /* quoted $VAR, val will be appended below */
5977 output->has_quoted_part = 1;
5978 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5979 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5982 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5984 if (val && val[0]) {
5985 o_addQstr(output, val);
5989 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5990 * Do the check to avoid writing to a const string. */
5991 if (*p != SPECIAL_VAR_SYMBOL)
5992 *p = SPECIAL_VAR_SYMBOL;
5994 #if ENABLE_HUSH_TICK
5995 o_free(&subst_result);
5998 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6002 o_addchr(output, '\0');
6003 n = o_save_ptr(output, n);
6005 debug_print_list("expand_vars_to_list[a]", output, n);
6006 /* this part is literal, and it was already pre-quoted
6007 * if needed (much earlier), do not use o_addQstr here! */
6008 o_addstr_with_NUL(output, arg);
6009 debug_print_list("expand_vars_to_list[b]", output, n);
6010 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6011 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6014 /* allow to reuse list[n] later without re-growth */
6015 output->has_empty_slot = 1;
6017 o_addchr(output, '\0');
6023 static char **expand_variables(char **argv, unsigned expflags)
6027 o_string output = NULL_O_STRING;
6029 output.o_expflags = expflags;
6033 n = expand_vars_to_list(&output, n, *argv);
6036 debug_print_list("expand_variables", &output, n);
6038 /* output.data (malloced in one block) gets returned in "list" */
6039 list = o_finalize_list(&output, n);
6040 debug_print_strings("expand_variables[1]", list);
6044 static char **expand_strvec_to_strvec(char **argv)
6046 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6050 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6052 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6056 /* Used for expansion of right hand of assignments,
6057 * $((...)), heredocs, variable espansion parts.
6059 * NB: should NOT do globbing!
6060 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6062 static char *expand_string_to_string(const char *str, int do_unbackslash)
6064 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6065 const int do_unbackslash = 1;
6067 char *argv[2], **list;
6069 debug_printf_expand("string_to_string<='%s'\n", str);
6070 /* This is generally an optimization, but it also
6071 * handles "", which otherwise trips over !list[0] check below.
6072 * (is this ever happens that we actually get str="" here?)
6074 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6075 //TODO: Can use on strings with \ too, just unbackslash() them?
6076 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6077 return xstrdup(str);
6080 argv[0] = (char*)str;
6082 list = expand_variables(argv, do_unbackslash
6083 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6084 : EXP_FLAG_SINGLEWORD
6087 if (!list[0] || list[1])
6088 bb_error_msg_and_die("BUG in varexp2");
6089 /* actually, just move string 2*sizeof(char*) bytes back */
6090 overlapping_strcpy((char*)list, list[0]);
6092 unbackslash((char*)list);
6093 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6097 /* Used for "eval" builtin and case string */
6098 static char* expand_strvec_to_string(char **argv)
6102 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6103 /* Convert all NULs to spaces */
6108 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6109 bb_error_msg_and_die("BUG in varexp3");
6110 /* bash uses ' ' regardless of $IFS contents */
6115 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6116 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6120 static char **expand_assignments(char **argv, int count)
6125 G.expanded_assignments = p = NULL;
6126 /* Expand assignments into one string each */
6127 for (i = 0; i < count; i++) {
6128 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6130 G.expanded_assignments = NULL;
6135 static void switch_off_special_sigs(unsigned mask)
6138 while ((mask >>= 1) != 0) {
6142 #if ENABLE_HUSH_TRAP
6144 if (G_traps[sig] && !G_traps[sig][0])
6145 /* trap is '', has to remain SIG_IGN */
6148 G_traps[sig] = NULL;
6151 /* We are here only if no trap or trap was not '' */
6152 install_sighandler(sig, SIG_DFL);
6158 void re_execute_shell(char ***to_free, const char *s,
6159 char *g_argv0, char **g_argv,
6160 char **builtin_argv) NORETURN;
6162 static void reset_traps_to_defaults(void)
6164 /* This function is always called in a child shell
6165 * after fork (not vfork, NOMMU doesn't use this function).
6167 IF_HUSH_TRAP(unsigned sig;)
6170 /* Child shells are not interactive.
6171 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6172 * Testcase: (while :; do :; done) + ^Z should background.
6173 * Same goes for SIGTERM, SIGHUP, SIGINT.
6175 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6176 if (!G_traps && !mask)
6177 return; /* already no traps and no special sigs */
6179 /* Switch off special sigs */
6180 switch_off_special_sigs(mask);
6181 # if ENABLE_HUSH_JOB
6182 G_fatal_sig_mask = 0;
6184 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6185 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6186 * remain set in G.special_sig_mask */
6188 # if ENABLE_HUSH_TRAP
6192 /* Reset all sigs to default except ones with empty traps */
6193 for (sig = 0; sig < NSIG; sig++) {
6195 continue; /* no trap: nothing to do */
6196 if (!G_traps[sig][0])
6197 continue; /* empty trap: has to remain SIG_IGN */
6198 /* sig has non-empty trap, reset it: */
6200 G_traps[sig] = NULL;
6201 /* There is no signal for trap 0 (EXIT) */
6204 install_sighandler(sig, pick_sighandler(sig));
6211 static void re_execute_shell(char ***to_free, const char *s,
6212 char *g_argv0, char **g_argv,
6213 char **builtin_argv) NORETURN;
6214 static void re_execute_shell(char ***to_free, const char *s,
6215 char *g_argv0, char **g_argv,
6216 char **builtin_argv)
6218 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6219 /* delims + 2 * (number of bytes in printed hex numbers) */
6220 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6221 char *heredoc_argv[4];
6222 struct variable *cur;
6223 # if ENABLE_HUSH_FUNCTIONS
6224 struct function *funcp;
6228 unsigned long long empty_trap_mask;
6230 if (!g_argv0) { /* heredoc */
6231 argv = heredoc_argv;
6232 argv[0] = (char *) G.argv0_for_re_execing;
6233 argv[1] = (char *) "-<";
6234 argv[2] = (char *) s;
6236 pp = &argv[3]; /* used as pointer to empty environment */
6242 if (pp) while (*pp++)
6245 empty_trap_mask = 0;
6248 for (sig = 1; sig < NSIG; sig++) {
6249 if (G_traps[sig] && !G_traps[sig][0])
6250 empty_trap_mask |= 1LL << sig;
6254 sprintf(param_buf, NOMMU_HACK_FMT
6255 , (unsigned) G.root_pid
6256 , (unsigned) G.root_ppid
6257 , (unsigned) G.last_bg_pid
6258 , (unsigned) G.last_exitcode
6261 IF_HUSH_LOOPS(, G.depth_of_loop)
6263 # undef NOMMU_HACK_FMT
6264 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6265 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6268 for (cur = G.top_var; cur; cur = cur->next) {
6269 if (!cur->flg_export || cur->flg_read_only)
6272 # if ENABLE_HUSH_FUNCTIONS
6273 for (funcp = G.top_func; funcp; funcp = funcp->next)
6279 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6280 *pp++ = (char *) G.argv0_for_re_execing;
6282 for (cur = G.top_var; cur; cur = cur->next) {
6283 if (strcmp(cur->varstr, hush_version_str) == 0)
6285 if (cur->flg_read_only) {
6286 *pp++ = (char *) "-R";
6287 *pp++ = cur->varstr;
6288 } else if (!cur->flg_export) {
6289 *pp++ = (char *) "-V";
6290 *pp++ = cur->varstr;
6293 # if ENABLE_HUSH_FUNCTIONS
6294 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6295 *pp++ = (char *) "-F";
6296 *pp++ = funcp->name;
6297 *pp++ = funcp->body_as_string;
6300 /* We can pass activated traps here. Say, -Tnn:trap_string
6302 * However, POSIX says that subshells reset signals with traps
6304 * I tested bash-3.2 and it not only does that with true subshells
6305 * of the form ( list ), but with any forked children shells.
6306 * I set trap "echo W" WINCH; and then tried:
6308 * { echo 1; sleep 20; echo 2; } &
6309 * while true; do echo 1; sleep 20; echo 2; break; done &
6310 * true | { echo 1; sleep 20; echo 2; } | cat
6312 * In all these cases sending SIGWINCH to the child shell
6313 * did not run the trap. If I add trap "echo V" WINCH;
6314 * _inside_ group (just before echo 1), it works.
6316 * I conclude it means we don't need to pass active traps here.
6318 *pp++ = (char *) "-c";
6321 while (*++builtin_argv)
6322 *pp++ = *builtin_argv;
6323 *pp++ = (char *) "";
6328 /* *pp = NULL; - is already there */
6332 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6333 /* Don't propagate SIG_IGN to the child */
6334 if (SPECIAL_JOBSTOP_SIGS != 0)
6335 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6336 execve(bb_busybox_exec_path, argv, pp);
6337 /* Fallback. Useful for init=/bin/hush usage etc */
6338 if (argv[0][0] == '/')
6339 execve(argv[0], argv, pp);
6340 xfunc_error_retval = 127;
6341 bb_error_msg_and_die("can't re-execute the shell");
6343 #endif /* !BB_MMU */
6346 static int run_and_free_list(struct pipe *pi);
6348 /* Executing from string: eval, sh -c '...'
6349 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6350 * end_trigger controls how often we stop parsing
6351 * NUL: parse all, execute, return
6352 * ';': parse till ';' or newline, execute, repeat till EOF
6354 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6356 /* Why we need empty flag?
6357 * An obscure corner case "false; ``; echo $?":
6358 * empty command in `` should still set $? to 0.
6359 * But we can't just set $? to 0 at the start,
6360 * this breaks "false; echo `echo $?`" case.
6364 struct pipe *pipe_list;
6366 #if ENABLE_HUSH_INTERACTIVE
6367 if (end_trigger == ';')
6368 inp->promptmode = 0; /* PS1 */
6370 pipe_list = parse_stream(NULL, inp, end_trigger);
6371 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6372 /* If we are in "big" script
6373 * (not in `cmd` or something similar)...
6375 if (pipe_list == ERR_PTR && end_trigger == ';') {
6376 /* Discard cached input (rest of line) */
6377 int ch = inp->last_char;
6378 while (ch != EOF && ch != '\n') {
6379 //bb_error_msg("Discarded:'%c'", ch);
6384 /* This stream isn't empty */
6388 if (!pipe_list && empty)
6389 G.last_exitcode = 0;
6392 debug_print_tree(pipe_list, 0);
6393 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6394 run_and_free_list(pipe_list);
6396 if (G_flag_return_in_progress == 1)
6401 static void parse_and_run_string(const char *s)
6403 struct in_str input;
6404 setup_string_in_str(&input, s);
6405 parse_and_run_stream(&input, '\0');
6408 static void parse_and_run_file(FILE *f)
6410 struct in_str input;
6411 setup_file_in_str(&input, f);
6412 parse_and_run_stream(&input, ';');
6415 #if ENABLE_HUSH_TICK
6416 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6421 char **to_free = NULL;
6425 pid = BB_MMU ? xfork() : xvfork();
6426 if (pid == 0) { /* child */
6427 disable_restore_tty_pgrp_on_exit();
6428 /* Process substitution is not considered to be usual
6429 * 'command execution'.
6430 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6437 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6438 close(channel[0]); /* NB: close _first_, then move fd! */
6439 xmove_fd(channel[1], 1);
6440 /* Prevent it from trying to handle ctrl-z etc */
6441 IF_HUSH_JOB(G.run_list_level = 1;)
6442 # if ENABLE_HUSH_TRAP
6443 /* Awful hack for `trap` or $(trap).
6445 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6446 * contains an example where "trap" is executed in a subshell:
6448 * save_traps=$(trap)
6450 * eval "$save_traps"
6452 * Standard does not say that "trap" in subshell shall print
6453 * parent shell's traps. It only says that its output
6454 * must have suitable form, but then, in the above example
6455 * (which is not supposed to be normative), it implies that.
6457 * bash (and probably other shell) does implement it
6458 * (traps are reset to defaults, but "trap" still shows them),
6459 * but as a result, "trap" logic is hopelessly messed up:
6462 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6463 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6464 * # true | trap <--- trap is in subshell - no output (ditto)
6465 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6466 * trap -- 'echo Ho' SIGWINCH
6467 * # echo `(trap)` <--- in subshell in subshell - output
6468 * trap -- 'echo Ho' SIGWINCH
6469 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6470 * trap -- 'echo Ho' SIGWINCH
6472 * The rules when to forget and when to not forget traps
6473 * get really complex and nonsensical.
6475 * Our solution: ONLY bare $(trap) or `trap` is special.
6477 s = skip_whitespace(s);
6478 if (is_prefixed_with(s, "trap")
6479 && skip_whitespace(s + 4)[0] == '\0'
6481 static const char *const argv[] = { NULL, NULL };
6482 builtin_trap((char**)argv);
6483 fflush_all(); /* important */
6488 reset_traps_to_defaults();
6489 parse_and_run_string(s);
6490 _exit(G.last_exitcode);
6492 /* We re-execute after vfork on NOMMU. This makes this script safe:
6493 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6494 * huge=`cat BIG` # was blocking here forever
6497 re_execute_shell(&to_free,
6507 # if ENABLE_HUSH_FAST
6509 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6510 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6511 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6513 enable_restore_tty_pgrp_on_exit();
6518 return remember_FILE(xfdopen_for_read(channel[0]));
6521 /* Return code is exit status of the process that is run. */
6522 static int process_command_subs(o_string *dest, const char *s)
6525 struct in_str pipe_str;
6527 int status, ch, eol_cnt;
6529 fp = generate_stream_from_string(s, &pid);
6531 /* Now send results of command back into original context */
6532 setup_file_in_str(&pipe_str, fp);
6534 while ((ch = i_getch(&pipe_str)) != EOF) {
6540 o_addchr(dest, '\n');
6543 o_addQchr(dest, ch);
6546 debug_printf("done reading from `cmd` pipe, closing it\n");
6547 fclose_and_forget(fp);
6548 /* We need to extract exitcode. Test case
6549 * "true; echo `sleep 1; false` $?"
6551 safe_waitpid(pid, &status, 0);
6552 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6553 return WEXITSTATUS(status);
6555 #endif /* ENABLE_HUSH_TICK */
6558 static void setup_heredoc(struct redir_struct *redir)
6560 struct fd_pair pair;
6563 /* the _body_ of heredoc (misleading field name) */
6564 const char *heredoc = redir->rd_filename;
6571 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6572 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6576 len = strlen(heredoc);
6578 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6580 xmove_fd(pair.rd, redir->rd_fd);
6582 /* Try writing without forking. Newer kernels have
6583 * dynamically growing pipes. Must use non-blocking write! */
6586 written = write(pair.wr, heredoc, len);
6597 ndelay_off(pair.wr);
6599 /* Okay, pipe buffer was not big enough */
6600 /* Note: we must not create a stray child (bastard? :)
6601 * for the unsuspecting parent process. Child creates a grandchild
6602 * and exits before parent execs the process which consumes heredoc
6603 * (that exec happens after we return from this function) */
6610 disable_restore_tty_pgrp_on_exit();
6611 pid = BB_MMU ? xfork() : xvfork();
6615 close(redir->rd_fd); /* read side of the pipe */
6617 full_write(pair.wr, heredoc, len); /* may loop or block */
6620 /* Delegate blocking writes to another process */
6621 xmove_fd(pair.wr, STDOUT_FILENO);
6622 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6626 #if ENABLE_HUSH_FAST
6628 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6630 enable_restore_tty_pgrp_on_exit();
6636 wait(NULL); /* wait till child has died */
6642 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6643 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6646 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6648 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6649 sq[i].orig_fd = orig;
6650 sq[i].moved_to = moved;
6651 sq[i+1].orig_fd = -1; /* end marker */
6655 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6660 if (sq) while (sq[i].orig_fd >= 0) {
6661 /* If we collide with an already moved fd... */
6662 if (fd == sq[i].moved_to) {
6663 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6664 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6665 if (sq[i].moved_to < 0) /* what? */
6669 if (fd == sq[i].orig_fd) {
6670 /* Example: echo Hello >/dev/null 1>&2 */
6671 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6677 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6678 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6679 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6680 if (moved_to < 0 && errno != EBADF)
6682 return append_squirrel(sq, i, fd, moved_to);
6685 /* fd: redirect wants this fd to be used (e.g. 3>file).
6686 * Move all conflicting internally used fds,
6687 * and remember them so that we can restore them later.
6689 static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6691 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6694 #if ENABLE_HUSH_INTERACTIVE
6695 if (fd != 0 && fd == G.interactive_fd) {
6696 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd);
6697 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6698 return 1; /* "we closed fd" */
6701 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6702 * (1) Redirect in a forked child. No need to save FILEs' fds,
6703 * we aren't going to use them anymore, ok to trash.
6704 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6705 * but how are we doing to restore them?
6706 * "fileno(fd) = new_fd" can't be done.
6711 /* If this one of script's fds? */
6712 if (save_FILEs_on_redirect(fd, avoid_fd))
6713 return 1; /* yes. "we closed fd" */
6715 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6716 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6717 return 0; /* "we did not close fd" */
6720 static void restore_redirects(struct squirrel *sq)
6725 while (sq[i].orig_fd >= 0) {
6726 if (sq[i].moved_to >= 0) {
6727 /* We simply die on error */
6728 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6729 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6731 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6732 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6733 close(sq[i].orig_fd);
6740 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6742 restore_redirected_FILEs();
6745 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6746 * and stderr if they are redirected. */
6747 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6750 struct redir_struct *redir;
6752 for (redir = prog->redirects; redir; redir = redir->next) {
6753 if (redir->rd_type == REDIRECT_HEREDOC2) {
6754 /* "rd_fd<<HERE" case */
6755 save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6756 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6758 debug_printf_parse("set heredoc '%s'\n",
6759 redir->rd_filename);
6760 setup_heredoc(redir);
6764 if (redir->rd_dup == REDIRFD_TO_FILE) {
6765 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6767 if (redir->rd_filename == NULL) {
6770 * "cmd >" (no filename)
6771 * "cmd > <file" (2nd redirect starts too early)
6773 die_if_script("syntax error: %s", "invalid redirect");
6776 mode = redir_table[redir->rd_type].mode;
6777 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6778 openfd = open_or_warn(p, mode);
6781 /* Error message from open_or_warn can be lost
6782 * if stderr has been redirected, but bash
6783 * and ash both lose it as well
6784 * (though zsh doesn't!)
6788 if (openfd == redir->rd_fd && sqp) {
6789 /* open() gave us precisely the fd we wanted.
6790 * This means that this fd was not busy
6791 * (not opened to anywhere).
6792 * Remember to close it on restore:
6794 struct squirrel *sq = *sqp;
6796 if (sq) while (sq[i].orig_fd >= 0)
6798 *sqp = append_squirrel(sq, i, openfd, -1); /* -1 = "it was closed" */
6799 debug_printf_redir("redir to previously closed fd %d\n", openfd);
6802 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6803 openfd = redir->rd_dup;
6806 if (openfd != redir->rd_fd) {
6807 int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp);
6808 if (openfd == REDIRFD_CLOSE) {
6809 /* "rd_fd >&-" means "close me" */
6811 /* ^^^ optimization: saving may already
6812 * have closed it. If not... */
6813 close(redir->rd_fd);
6816 xdup2(openfd, redir->rd_fd);
6817 if (redir->rd_dup == REDIRFD_TO_FILE)
6818 /* "rd_fd > FILE" */
6820 /* else: "rd_fd > rd_dup" */
6827 static char *find_in_path(const char *arg)
6830 const char *PATH = get_local_var_value("PATH");
6836 const char *end = strchrnul(PATH, ':');
6837 int sz = end - PATH; /* must be int! */
6841 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6843 /* We have xxx::yyyy in $PATH,
6844 * it means "use current dir" */
6847 if (access(ret, F_OK) == 0)
6860 static const struct built_in_command *find_builtin_helper(const char *name,
6861 const struct built_in_command *x,
6862 const struct built_in_command *end)
6865 if (strcmp(name, x->b_cmd) != 0) {
6869 debug_printf_exec("found builtin '%s'\n", name);
6874 static const struct built_in_command *find_builtin1(const char *name)
6876 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6878 static const struct built_in_command *find_builtin(const char *name)
6880 const struct built_in_command *x = find_builtin1(name);
6883 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6886 #if ENABLE_HUSH_FUNCTIONS
6887 static struct function **find_function_slot(const char *name)
6889 struct function **funcpp = &G.top_func;
6891 if (strcmp(name, (*funcpp)->name) == 0) {
6894 funcpp = &(*funcpp)->next;
6899 static const struct function *find_function(const char *name)
6901 const struct function *funcp = *find_function_slot(name);
6903 debug_printf_exec("found function '%s'\n", name);
6907 /* Note: takes ownership on name ptr */
6908 static struct function *new_function(char *name)
6910 struct function **funcpp = find_function_slot(name);
6911 struct function *funcp = *funcpp;
6913 if (funcp != NULL) {
6914 struct command *cmd = funcp->parent_cmd;
6915 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6917 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6919 /* Note: if !funcp->body, do not free body_as_string!
6920 * This is a special case of "-F name body" function:
6921 * body_as_string was not malloced! */
6923 free_pipe_list(funcp->body);
6925 free(funcp->body_as_string);
6929 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6930 cmd->argv[0] = funcp->name;
6931 cmd->group = funcp->body;
6933 cmd->group_as_string = funcp->body_as_string;
6937 debug_printf_exec("remembering new function '%s'\n", name);
6938 funcp = *funcpp = xzalloc(sizeof(*funcp));
6939 /*funcp->next = NULL;*/
6946 # if ENABLE_HUSH_UNSET
6947 static void unset_func(const char *name)
6949 struct function **funcpp = find_function_slot(name);
6950 struct function *funcp = *funcpp;
6952 if (funcp != NULL) {
6953 debug_printf_exec("freeing function '%s'\n", funcp->name);
6954 *funcpp = funcp->next;
6955 /* funcp is unlinked now, deleting it.
6956 * Note: if !funcp->body, the function was created by
6957 * "-F name body", do not free ->body_as_string
6958 * and ->name as they were not malloced. */
6960 free_pipe_list(funcp->body);
6963 free(funcp->body_as_string);
6972 #define exec_function(to_free, funcp, argv) \
6973 exec_function(funcp, argv)
6975 static void exec_function(char ***to_free,
6976 const struct function *funcp,
6977 char **argv) NORETURN;
6978 static void exec_function(char ***to_free,
6979 const struct function *funcp,
6985 argv[0] = G.global_argv[0];
6986 G.global_argv = argv;
6987 G.global_argc = n = 1 + string_array_len(argv + 1);
6988 /* On MMU, funcp->body is always non-NULL */
6989 n = run_list(funcp->body);
6993 re_execute_shell(to_free,
6994 funcp->body_as_string,
7001 static int run_function(const struct function *funcp, char **argv)
7007 save_and_replace_G_args(&sv, argv);
7009 /* "we are in function, ok to use return" */
7010 sv_flg = G_flag_return_in_progress;
7011 G_flag_return_in_progress = -1;
7012 # if ENABLE_HUSH_LOCAL
7013 G.func_nest_level++;
7016 /* On MMU, funcp->body is always non-NULL */
7019 /* Function defined by -F */
7020 parse_and_run_string(funcp->body_as_string);
7021 rc = G.last_exitcode;
7025 rc = run_list(funcp->body);
7028 # if ENABLE_HUSH_LOCAL
7030 struct variable *var;
7031 struct variable **var_pp;
7033 var_pp = &G.top_var;
7034 while ((var = *var_pp) != NULL) {
7035 if (var->func_nest_level < G.func_nest_level) {
7036 var_pp = &var->next;
7040 if (var->flg_export)
7041 bb_unsetenv(var->varstr);
7042 /* Remove from global list */
7043 *var_pp = var->next;
7049 G.func_nest_level--;
7052 G_flag_return_in_progress = sv_flg;
7054 restore_G_args(&sv, argv);
7058 #endif /* ENABLE_HUSH_FUNCTIONS */
7062 #define exec_builtin(to_free, x, argv) \
7063 exec_builtin(x, argv)
7065 #define exec_builtin(to_free, x, argv) \
7066 exec_builtin(to_free, argv)
7068 static void exec_builtin(char ***to_free,
7069 const struct built_in_command *x,
7070 char **argv) NORETURN;
7071 static void exec_builtin(char ***to_free,
7072 const struct built_in_command *x,
7078 rcode = x->b_function(argv);
7083 /* On NOMMU, we must never block!
7084 * Example: { sleep 99 | read line; } & echo Ok
7086 re_execute_shell(to_free,
7095 static void execvp_or_die(char **argv) NORETURN;
7096 static void execvp_or_die(char **argv)
7099 debug_printf_exec("execing '%s'\n", argv[0]);
7100 /* Don't propagate SIG_IGN to the child */
7101 if (SPECIAL_JOBSTOP_SIGS != 0)
7102 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7103 execvp(argv[0], argv);
7105 if (errno == EACCES) e = 126;
7106 if (errno == ENOENT) e = 127;
7107 bb_perror_msg("can't execute '%s'", argv[0]);
7111 #if ENABLE_HUSH_MODE_X
7112 static void dump_cmd_in_x_mode(char **argv)
7114 if (G_x_mode && argv) {
7115 /* We want to output the line in one write op */
7123 len += strlen(argv[n++]) + 1;
7129 p += sprintf(p, " %s", argv[n++]);
7137 # define dump_cmd_in_x_mode(argv) ((void)0)
7141 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7142 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7143 #define pseudo_exec(nommu_save, command, argv_expanded) \
7144 pseudo_exec(command, argv_expanded)
7147 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7149 * Don't exit() here. If you don't exec, use _exit instead.
7150 * The at_exit handlers apparently confuse the calling process,
7151 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7153 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7154 char **argv, int assignment_cnt,
7155 char **argv_expanded) NORETURN;
7156 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7157 char **argv, int assignment_cnt,
7158 char **argv_expanded)
7162 new_env = expand_assignments(argv, assignment_cnt);
7163 dump_cmd_in_x_mode(new_env);
7165 if (!argv[assignment_cnt]) {
7166 /* Case when we are here: ... | var=val | ...
7167 * (note that we do not exit early, i.e., do not optimize out
7168 * expand_assignments(): think about ... | var=`sleep 1` | ...
7170 free_strings(new_env);
7171 _exit(EXIT_SUCCESS);
7175 set_vars_and_save_old(new_env);
7176 free(new_env); /* optional */
7177 /* we can also destroy set_vars_and_save_old's return value,
7180 nommu_save->new_env = new_env;
7181 nommu_save->old_vars = set_vars_and_save_old(new_env);
7184 if (argv_expanded) {
7185 argv = argv_expanded;
7187 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7189 nommu_save->argv = argv;
7192 dump_cmd_in_x_mode(argv);
7194 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7195 if (strchr(argv[0], '/') != NULL)
7199 /* Check if the command matches any of the builtins.
7200 * Depending on context, this might be redundant. But it's
7201 * easier to waste a few CPU cycles than it is to figure out
7202 * if this is one of those cases.
7205 /* On NOMMU, it is more expensive to re-execute shell
7206 * just in order to run echo or test builtin.
7207 * It's better to skip it here and run corresponding
7208 * non-builtin later. */
7209 const struct built_in_command *x;
7210 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7212 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7215 #if ENABLE_HUSH_FUNCTIONS
7216 /* Check if the command matches any functions */
7218 const struct function *funcp = find_function(argv[0]);
7220 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7225 #if ENABLE_FEATURE_SH_STANDALONE
7226 /* Check if the command matches any busybox applets */
7228 int a = find_applet_by_name(argv[0]);
7230 # if BB_MMU /* see above why on NOMMU it is not allowed */
7231 if (APPLET_IS_NOEXEC(a)) {
7232 /* Do not leak open fds from opened script files etc */
7233 close_all_FILE_list();
7234 debug_printf_exec("running applet '%s'\n", argv[0]);
7235 run_applet_no_and_exit(a, argv[0], argv);
7238 /* Re-exec ourselves */
7239 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7240 /* Don't propagate SIG_IGN to the child */
7241 if (SPECIAL_JOBSTOP_SIGS != 0)
7242 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7243 execv(bb_busybox_exec_path, argv);
7244 /* If they called chroot or otherwise made the binary no longer
7245 * executable, fall through */
7250 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7253 execvp_or_die(argv);
7256 /* Called after [v]fork() in run_pipe
7258 static void pseudo_exec(nommu_save_t *nommu_save,
7259 struct command *command,
7260 char **argv_expanded) NORETURN;
7261 static void pseudo_exec(nommu_save_t *nommu_save,
7262 struct command *command,
7263 char **argv_expanded)
7265 if (command->argv) {
7266 pseudo_exec_argv(nommu_save, command->argv,
7267 command->assignment_cnt, argv_expanded);
7270 if (command->group) {
7271 /* Cases when we are here:
7274 * ... | ( list ) | ...
7275 * ... | { list } | ...
7279 debug_printf_exec("pseudo_exec: run_list\n");
7280 reset_traps_to_defaults();
7281 rcode = run_list(command->group);
7282 /* OK to leak memory by not calling free_pipe_list,
7283 * since this process is about to exit */
7286 re_execute_shell(&nommu_save->argv_from_re_execing,
7287 command->group_as_string,
7294 /* Case when we are here: ... | >file */
7295 debug_printf_exec("pseudo_exec'ed null command\n");
7296 _exit(EXIT_SUCCESS);
7300 static const char *get_cmdtext(struct pipe *pi)
7306 /* This is subtle. ->cmdtext is created only on first backgrounding.
7307 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7308 * On subsequent bg argv is trashed, but we won't use it */
7312 argv = pi->cmds[0].argv;
7314 pi->cmdtext = xzalloc(1);
7319 len += strlen(*argv) + 1;
7323 argv = pi->cmds[0].argv;
7325 p = stpcpy(p, *argv);
7332 static void remove_job_from_table(struct pipe *pi)
7334 struct pipe *prev_pipe;
7336 if (pi == G.job_list) {
7337 G.job_list = pi->next;
7339 prev_pipe = G.job_list;
7340 while (prev_pipe->next != pi)
7341 prev_pipe = prev_pipe->next;
7342 prev_pipe->next = pi->next;
7346 G.last_jobid = G.job_list->jobid;
7349 static void delete_finished_job(struct pipe *pi)
7351 remove_job_from_table(pi);
7355 static void clean_up_last_dead_job(void)
7357 if (G.job_list && !G.job_list->alive_cmds)
7358 delete_finished_job(G.job_list);
7361 static void insert_job_into_table(struct pipe *pi)
7363 struct pipe *job, **jobp;
7366 clean_up_last_dead_job();
7368 /* Find the end of the list, and find next job ID to use */
7371 while ((job = *jobp) != NULL) {
7378 /* Create a new job struct at the end */
7379 job = *jobp = xmemdup(pi, sizeof(*pi));
7381 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7382 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7383 for (i = 0; i < pi->num_cmds; i++) {
7384 job->cmds[i].pid = pi->cmds[i].pid;
7385 /* all other fields are not used and stay zero */
7387 job->cmdtext = xstrdup(get_cmdtext(pi));
7389 if (G_interactive_fd)
7390 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7391 G.last_jobid = job->jobid;
7395 static int job_exited_or_stopped(struct pipe *pi)
7399 if (pi->alive_cmds != pi->stopped_cmds)
7402 /* All processes in fg pipe have exited or stopped */
7406 rcode = pi->cmds[i].cmd_exitcode;
7407 /* usually last process gives overall exitstatus,
7408 * but with "set -o pipefail", last *failed* process does */
7409 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7412 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7416 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7423 dead = WIFEXITED(status) || WIFSIGNALED(status);
7426 if (WIFSTOPPED(status))
7427 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7428 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7429 if (WIFSIGNALED(status))
7430 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7431 childpid, WTERMSIG(status), WEXITSTATUS(status));
7432 if (WIFEXITED(status))
7433 debug_printf_jobs("pid %d exited, exitcode %d\n",
7434 childpid, WEXITSTATUS(status));
7436 /* Were we asked to wait for a fg pipe? */
7438 i = fg_pipe->num_cmds;
7443 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7444 if (fg_pipe->cmds[i].pid != childpid)
7448 fg_pipe->cmds[i].pid = 0;
7449 fg_pipe->alive_cmds--;
7450 ex = WEXITSTATUS(status);
7451 /* bash prints killer signal's name for *last*
7452 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7453 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7455 if (WIFSIGNALED(status)) {
7456 int sig = WTERMSIG(status);
7457 if (i == fg_pipe->num_cmds-1)
7458 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7459 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7460 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7461 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7462 * Maybe we need to use sig | 128? */
7465 fg_pipe->cmds[i].cmd_exitcode = ex;
7467 fg_pipe->stopped_cmds++;
7469 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7470 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7471 rcode = job_exited_or_stopped(fg_pipe);
7473 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7474 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7475 * and "killall -STOP cat" */
7476 if (G_interactive_fd) {
7478 if (fg_pipe->alive_cmds != 0)
7479 insert_job_into_table(fg_pipe);
7483 if (fg_pipe->alive_cmds == 0)
7486 /* There are still running processes in the fg_pipe */
7489 /* It wasn't in fg_pipe, look for process in bg pipes */
7493 /* We were asked to wait for bg or orphaned children */
7494 /* No need to remember exitcode in this case */
7495 for (pi = G.job_list; pi; pi = pi->next) {
7496 for (i = 0; i < pi->num_cmds; i++) {
7497 if (pi->cmds[i].pid == childpid)
7498 goto found_pi_and_prognum;
7501 /* Happens when shell is used as init process (init=/bin/sh) */
7502 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7503 return -1; /* this wasn't a process from fg_pipe */
7505 found_pi_and_prognum:
7508 int rcode = WEXITSTATUS(status);
7509 if (WIFSIGNALED(status))
7510 rcode = 128 + WTERMSIG(status);
7511 pi->cmds[i].cmd_exitcode = rcode;
7512 if (G.last_bg_pid == pi->cmds[i].pid)
7513 G.last_bg_pid_exitcode = rcode;
7514 pi->cmds[i].pid = 0;
7516 if (!pi->alive_cmds) {
7517 if (G_interactive_fd) {
7518 printf(JOB_STATUS_FORMAT, pi->jobid,
7519 "Done", pi->cmdtext);
7520 delete_finished_job(pi);
7523 * bash deletes finished jobs from job table only in interactive mode,
7524 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7525 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7526 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7527 * We only retain one "dead" job, if it's the single job on the list.
7528 * This covers most of real-world scenarios where this is useful.
7530 if (pi != G.job_list)
7531 delete_finished_job(pi);
7539 return -1; /* this wasn't a process from fg_pipe */
7542 /* Check to see if any processes have exited -- if they have,
7543 * figure out why and see if a job has completed.
7545 * If non-NULL fg_pipe: wait for its completion or stop.
7546 * Return its exitcode or zero if stopped.
7548 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7549 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7550 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7551 * or 0 if no children changed status.
7553 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7554 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7555 * or 0 if no children changed status.
7557 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7563 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7565 attributes = WUNTRACED;
7566 if (fg_pipe == NULL)
7567 attributes |= WNOHANG;
7570 #if ENABLE_HUSH_FAST
7571 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7572 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7573 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7574 /* There was neither fork nor SIGCHLD since last waitpid */
7575 /* Avoid doing waitpid syscall if possible */
7576 if (!G.we_have_children) {
7580 if (fg_pipe == NULL) { /* is WNOHANG set? */
7581 /* We have children, but they did not exit
7582 * or stop yet (we saw no SIGCHLD) */
7585 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7589 /* Do we do this right?
7590 * bash-3.00# sleep 20 | false
7592 * [3]+ Stopped sleep 20 | false
7593 * bash-3.00# echo $?
7594 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7595 * [hush 1.14.0: yes we do it right]
7599 #if ENABLE_HUSH_FAST
7601 i = G.count_SIGCHLD;
7603 childpid = waitpid(-1, &status, attributes);
7604 if (childpid <= 0) {
7605 if (childpid && errno != ECHILD)
7606 bb_perror_msg("waitpid");
7607 #if ENABLE_HUSH_FAST
7608 else { /* Until next SIGCHLD, waitpid's are useless */
7609 G.we_have_children = (childpid == 0);
7610 G.handled_SIGCHLD = i;
7611 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7614 /* ECHILD (no children), or 0 (no change in children status) */
7618 rcode = process_wait_result(fg_pipe, childpid, status);
7620 /* fg_pipe exited or stopped */
7623 if (childpid == waitfor_pid) {
7624 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7625 rcode = WEXITSTATUS(status);
7626 if (WIFSIGNALED(status))
7627 rcode = 128 + WTERMSIG(status);
7628 if (WIFSTOPPED(status))
7629 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7630 rcode = 128 + WSTOPSIG(status);
7632 break; /* "wait PID" called us, give it exitcode+1 */
7634 /* This wasn't one of our processes, or */
7635 /* fg_pipe still has running processes, do waitpid again */
7636 } /* while (waitpid succeeds)... */
7642 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7645 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7646 if (G_saved_tty_pgrp) {
7647 /* Job finished, move the shell to the foreground */
7648 p = getpgrp(); /* our process group id */
7649 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7650 tcsetpgrp(G_interactive_fd, p);
7656 /* Start all the jobs, but don't wait for anything to finish.
7659 * Return code is normally -1, when the caller has to wait for children
7660 * to finish to determine the exit status of the pipe. If the pipe
7661 * is a simple builtin command, however, the action is done by the
7662 * time run_pipe returns, and the exit code is provided as the
7665 * Returns -1 only if started some children. IOW: we have to
7666 * mask out retvals of builtins etc with 0xff!
7668 * The only case when we do not need to [v]fork is when the pipe
7669 * is single, non-backgrounded, non-subshell command. Examples:
7670 * cmd ; ... { list } ; ...
7671 * cmd && ... { list } && ...
7672 * cmd || ... { list } || ...
7673 * If it is, then we can run cmd as a builtin, NOFORK,
7674 * or (if SH_STANDALONE) an applet, and we can run the { list }
7675 * with run_list. If it isn't one of these, we fork and exec cmd.
7677 * Cases when we must fork:
7678 * non-single: cmd | cmd
7679 * backgrounded: cmd & { list } &
7680 * subshell: ( list ) [&]
7682 #if !ENABLE_HUSH_MODE_X
7683 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7684 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7686 static int redirect_and_varexp_helper(char ***new_env_p,
7687 struct variable **old_vars_p,
7688 struct command *command,
7689 struct squirrel **sqp,
7690 char **argv_expanded)
7692 /* setup_redirects acts on file descriptors, not FILEs.
7693 * This is perfect for work that comes after exec().
7694 * Is it really safe for inline use? Experimentally,
7695 * things seem to work. */
7696 int rcode = setup_redirects(command, sqp);
7698 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7699 *new_env_p = new_env;
7700 dump_cmd_in_x_mode(new_env);
7701 dump_cmd_in_x_mode(argv_expanded);
7703 *old_vars_p = set_vars_and_save_old(new_env);
7707 static NOINLINE int run_pipe(struct pipe *pi)
7709 static const char *const null_ptr = NULL;
7713 struct command *command;
7714 char **argv_expanded;
7716 struct squirrel *squirrel = NULL;
7719 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7722 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7723 * Result should be 3 lines: q w e, qwe, q w e
7725 G.ifs = get_local_var_value("IFS");
7729 IF_HUSH_JOB(pi->pgrp = -1;)
7730 pi->stopped_cmds = 0;
7731 command = &pi->cmds[0];
7732 argv_expanded = NULL;
7734 if (pi->num_cmds != 1
7735 || pi->followup == PIPE_BG
7736 || command->cmd_type == CMD_SUBSHELL
7743 debug_printf_exec(": group:%p argv:'%s'\n",
7744 command->group, command->argv ? command->argv[0] : "NONE");
7746 if (command->group) {
7747 #if ENABLE_HUSH_FUNCTIONS
7748 if (command->cmd_type == CMD_FUNCDEF) {
7749 /* "executing" func () { list } */
7750 struct function *funcp;
7752 funcp = new_function(command->argv[0]);
7753 /* funcp->name is already set to argv[0] */
7754 funcp->body = command->group;
7756 funcp->body_as_string = command->group_as_string;
7757 command->group_as_string = NULL;
7759 command->group = NULL;
7760 command->argv[0] = NULL;
7761 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7762 funcp->parent_cmd = command;
7763 command->child_func = funcp;
7765 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7767 return EXIT_SUCCESS;
7771 debug_printf("non-subshell group\n");
7772 rcode = 1; /* exitcode if redir failed */
7773 if (setup_redirects(command, &squirrel) == 0) {
7774 debug_printf_exec(": run_list\n");
7775 rcode = run_list(command->group) & 0xff;
7777 restore_redirects(squirrel);
7778 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7780 debug_printf_exec("run_pipe: return %d\n", rcode);
7784 argv = command->argv ? command->argv : (char **) &null_ptr;
7786 const struct built_in_command *x;
7787 #if ENABLE_HUSH_FUNCTIONS
7788 const struct function *funcp;
7792 char **new_env = NULL;
7793 struct variable *old_vars = NULL;
7795 if (argv[command->assignment_cnt] == NULL) {
7796 /* Assignments, but no command */
7797 /* Ensure redirects take effect (that is, create files).
7798 * Try "a=t >file" */
7799 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7800 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7801 /* Set shell variables */
7805 if (set_local_var(*argv, /*flag:*/ 0)) {
7806 /* assignment to readonly var / putenv error? */
7812 /* Redirect error sets $? to 1. Otherwise,
7813 * if evaluating assignment value set $?, retain it.
7814 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7816 rcode = G.last_exitcode;
7817 /* Exit, _skipping_ variable restoring code: */
7818 goto clean_up_and_ret0;
7820 #else /* Older, bigger, but more correct code */
7822 rcode = setup_redirects(command, &squirrel);
7823 restore_redirects(squirrel);
7824 /* Set shell variables */
7826 bb_putchar_stderr('+');
7828 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7830 fprintf(stderr, " %s", p);
7831 debug_printf_exec("set shell var:'%s'->'%s'\n",
7833 if (set_local_var(p, /*flag:*/ 0)) {
7834 /* assignment to readonly var / putenv error? */
7840 bb_putchar_stderr('\n');
7841 /* Redirect error sets $? to 1. Otherwise,
7842 * if evaluating assignment value set $?, retain it.
7843 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7845 rcode = G.last_exitcode;
7846 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7848 debug_printf_exec("run_pipe: return %d\n", rcode);
7853 /* Expand the rest into (possibly) many strings each */
7855 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7856 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7860 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7863 /* if someone gives us an empty string: `cmd with empty output` */
7864 if (!argv_expanded[0]) {
7865 free(argv_expanded);
7867 return G.last_exitcode;
7870 x = find_builtin(argv_expanded[0]);
7871 #if ENABLE_HUSH_FUNCTIONS
7874 funcp = find_function(argv_expanded[0]);
7878 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7879 debug_printf("exec with redirects only\n");
7880 rcode = setup_redirects(command, NULL);
7881 /* rcode=1 can be if redir file can't be opened */
7882 goto clean_up_and_ret1;
7885 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7888 debug_printf_exec(": builtin '%s' '%s'...\n",
7889 x->b_cmd, argv_expanded[1]);
7891 rcode = x->b_function(argv_expanded) & 0xff;
7894 #if ENABLE_HUSH_FUNCTIONS
7896 # if ENABLE_HUSH_LOCAL
7897 struct variable **sv;
7898 sv = G.shadowed_vars_pp;
7899 G.shadowed_vars_pp = &old_vars;
7901 debug_printf_exec(": function '%s' '%s'...\n",
7902 funcp->name, argv_expanded[1]);
7903 rcode = run_function(funcp, argv_expanded) & 0xff;
7904 # if ENABLE_HUSH_LOCAL
7905 G.shadowed_vars_pp = sv;
7911 unset_vars(new_env);
7913 /* clean_up_and_ret0: */
7914 restore_redirects(squirrel);
7916 free(argv_expanded);
7917 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7919 debug_printf_exec("run_pipe return %d\n", rcode);
7923 if (ENABLE_FEATURE_SH_NOFORK) {
7924 int n = find_applet_by_name(argv_expanded[0]);
7925 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7926 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
7928 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7929 argv_expanded[0], argv_expanded[1]);
7930 rcode = run_nofork_applet(n, argv_expanded);
7932 goto clean_up_and_ret;
7935 /* It is neither builtin nor applet. We must fork. */
7939 /* NB: argv_expanded may already be created, and that
7940 * might include `cmd` runs! Do not rerun it! We *must*
7941 * use argv_expanded if it's non-NULL */
7943 /* Going to fork a child per each pipe member */
7948 while (cmd_no < pi->num_cmds) {
7949 struct fd_pair pipefds;
7951 volatile nommu_save_t nommu_save;
7952 nommu_save.new_env = NULL;
7953 nommu_save.old_vars = NULL;
7954 nommu_save.argv = NULL;
7955 nommu_save.argv_from_re_execing = NULL;
7957 command = &pi->cmds[cmd_no];
7959 if (command->argv) {
7960 debug_printf_exec(": pipe member '%s' '%s'...\n",
7961 command->argv[0], command->argv[1]);
7963 debug_printf_exec(": pipe member with no argv\n");
7966 /* pipes are inserted between pairs of commands */
7969 if (cmd_no < pi->num_cmds)
7970 xpiped_pair(pipefds);
7972 command->pid = BB_MMU ? fork() : vfork();
7973 if (!command->pid) { /* child */
7975 disable_restore_tty_pgrp_on_exit();
7976 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7978 /* Every child adds itself to new process group
7979 * with pgid == pid_of_first_child_in_pipe */
7980 if (G.run_list_level == 1 && G_interactive_fd) {
7983 if (pgrp < 0) /* true for 1st process only */
7985 if (setpgid(0, pgrp) == 0
7986 && pi->followup != PIPE_BG
7987 && G_saved_tty_pgrp /* we have ctty */
7989 /* We do it in *every* child, not just first,
7991 tcsetpgrp(G_interactive_fd, pgrp);
7995 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7996 /* 1st cmd in backgrounded pipe
7997 * should have its stdin /dev/null'ed */
7999 if (open(bb_dev_null, O_RDONLY))
8000 xopen("/", O_RDONLY);
8002 xmove_fd(next_infd, 0);
8004 xmove_fd(pipefds.wr, 1);
8007 /* Like bash, explicit redirects override pipes,
8008 * and the pipe fd (fd#1) is available for dup'ing:
8009 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8010 * of cmd1 goes into pipe.
8012 if (setup_redirects(command, NULL)) {
8013 /* Happens when redir file can't be opened:
8014 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8016 * hush: can't open '/qwe/rty': No such file or directory
8018 * (echo BAR is not executed, it hits _exit(1) below)
8023 /* Stores to nommu_save list of env vars putenv'ed
8024 * (NOMMU, on MMU we don't need that) */
8025 /* cast away volatility... */
8026 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8027 /* pseudo_exec() does not return */
8030 /* parent or error */
8031 #if ENABLE_HUSH_FAST
8033 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8035 enable_restore_tty_pgrp_on_exit();
8037 /* Clean up after vforked child */
8038 free(nommu_save.argv);
8039 free(nommu_save.argv_from_re_execing);
8040 unset_vars(nommu_save.new_env);
8041 add_vars(nommu_save.old_vars);
8043 free(argv_expanded);
8044 argv_expanded = NULL;
8045 if (command->pid < 0) { /* [v]fork failed */
8046 /* Clearly indicate, was it fork or vfork */
8047 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8051 /* Second and next children need to know pid of first one */
8053 pi->pgrp = command->pid;
8059 if (cmd_no < pi->num_cmds)
8061 /* Pass read (output) pipe end to next iteration */
8062 next_infd = pipefds.rd;
8065 if (!pi->alive_cmds) {
8067 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8072 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8076 /* NB: called by pseudo_exec, and therefore must not modify any
8077 * global data until exec/_exit (we can be a child after vfork!) */
8078 static int run_list(struct pipe *pi)
8080 #if ENABLE_HUSH_CASE
8081 char *case_word = NULL;
8083 #if ENABLE_HUSH_LOOPS
8084 struct pipe *loop_top = NULL;
8085 char **for_lcur = NULL;
8086 char **for_list = NULL;
8088 smallint last_followup;
8090 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8091 smalluint cond_code = 0;
8093 enum { cond_code = 0 };
8096 smallint rword; /* RES_foo */
8097 smallint last_rword; /* ditto */
8100 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8103 #if ENABLE_HUSH_LOOPS
8104 /* Check syntax for "for" */
8107 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8108 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8110 /* current word is FOR or IN (BOLD in comments below) */
8111 if (cpipe->next == NULL) {
8112 syntax_error("malformed for");
8114 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8117 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8118 if (cpipe->next->res_word == RES_DO)
8120 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8121 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8122 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8124 syntax_error("malformed for");
8126 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8133 /* Past this point, all code paths should jump to ret: label
8134 * in order to return, no direct "return" statements please.
8135 * This helps to ensure that no memory is leaked. */
8143 last_rword = RES_XXXX;
8145 last_followup = PIPE_SEQ;
8146 rcode = G.last_exitcode;
8148 /* Go through list of pipes, (maybe) executing them. */
8149 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8151 int sv_errexit_depth;
8155 if (G_flag_return_in_progress == 1)
8158 IF_HAS_KEYWORDS(rword = pi->res_word;)
8159 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8160 rword, cond_code, last_rword);
8162 sv_errexit_depth = G.errexit_depth;
8163 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8164 pi->followup != PIPE_SEQ
8168 #if ENABLE_HUSH_LOOPS
8169 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8170 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8172 /* start of a loop: remember where loop starts */
8177 /* Still in the same "if...", "then..." or "do..." branch? */
8178 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8179 if ((rcode == 0 && last_followup == PIPE_OR)
8180 || (rcode != 0 && last_followup == PIPE_AND)
8182 /* It is "<true> || CMD" or "<false> && CMD"
8183 * and we should not execute CMD */
8184 debug_printf_exec("skipped cmd because of || or &&\n");
8185 last_followup = pi->followup;
8186 goto dont_check_jobs_but_continue;
8189 last_followup = pi->followup;
8190 IF_HAS_KEYWORDS(last_rword = rword;)
8193 if (rword == RES_THEN) {
8194 /* if false; then ... fi has exitcode 0! */
8195 G.last_exitcode = rcode = EXIT_SUCCESS;
8196 /* "if <false> THEN cmd": skip cmd */
8200 if (rword == RES_ELSE || rword == RES_ELIF) {
8201 /* "if <true> then ... ELSE/ELIF cmd":
8202 * skip cmd and all following ones */
8207 #if ENABLE_HUSH_LOOPS
8208 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8210 /* first loop through for */
8212 static const char encoded_dollar_at[] ALIGN1 = {
8213 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8214 }; /* encoded representation of "$@" */
8215 static const char *const encoded_dollar_at_argv[] = {
8216 encoded_dollar_at, NULL
8217 }; /* argv list with one element: "$@" */
8220 vals = (char**)encoded_dollar_at_argv;
8221 if (pi->next->res_word == RES_IN) {
8222 /* if no variable values after "in" we skip "for" */
8223 if (!pi->next->cmds[0].argv) {
8224 G.last_exitcode = rcode = EXIT_SUCCESS;
8225 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8228 vals = pi->next->cmds[0].argv;
8229 } /* else: "for var; do..." -> assume "$@" list */
8230 /* create list of variable values */
8231 debug_print_strings("for_list made from", vals);
8232 for_list = expand_strvec_to_strvec(vals);
8233 for_lcur = for_list;
8234 debug_print_strings("for_list", for_list);
8237 /* "for" loop is over, clean up */
8243 /* Insert next value from for_lcur */
8244 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8245 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8248 if (rword == RES_IN) {
8249 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8251 if (rword == RES_DONE) {
8252 continue; /* "done" has no cmds too */
8255 #if ENABLE_HUSH_CASE
8256 if (rword == RES_CASE) {
8257 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8258 case_word = expand_strvec_to_string(pi->cmds->argv);
8259 unbackslash(case_word);
8262 if (rword == RES_MATCH) {
8265 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8266 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8268 /* all prev words didn't match, does this one match? */
8269 argv = pi->cmds->argv;
8271 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8272 /* TODO: which FNM_xxx flags to use? */
8273 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8274 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8276 if (cond_code == 0) { /* match! we will execute this branch */
8278 case_word = NULL; /* make future "word)" stop */
8285 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8286 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8288 continue; /* not matched yet, skip this pipe */
8290 if (rword == RES_ESAC) {
8291 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8293 /* "case" did not match anything: still set $? (to 0) */
8294 G.last_exitcode = rcode = EXIT_SUCCESS;
8298 /* Just pressing <enter> in shell should check for jobs.
8299 * OTOH, in non-interactive shell this is useless
8300 * and only leads to extra job checks */
8301 if (pi->num_cmds == 0) {
8302 if (G_interactive_fd)
8303 goto check_jobs_and_continue;
8307 /* After analyzing all keywords and conditions, we decided
8308 * to execute this pipe. NB: have to do checkjobs(NULL)
8309 * after run_pipe to collect any background children,
8310 * even if list execution is to be stopped. */
8311 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8312 #if ENABLE_HUSH_LOOPS
8313 G.flag_break_continue = 0;
8315 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8317 /* We ran a builtin, function, or group.
8318 * rcode is already known
8319 * and we don't need to wait for anything. */
8320 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8321 G.last_exitcode = rcode;
8322 check_and_run_traps();
8323 #if ENABLE_HUSH_LOOPS
8324 /* Was it "break" or "continue"? */
8325 if (G.flag_break_continue) {
8326 smallint fbc = G.flag_break_continue;
8327 /* We might fall into outer *loop*,
8328 * don't want to break it too */
8330 G.depth_break_continue--;
8331 if (G.depth_break_continue == 0)
8332 G.flag_break_continue = 0;
8333 /* else: e.g. "continue 2" should *break* once, *then* continue */
8334 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8335 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8336 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8339 /* "continue": simulate end of loop */
8344 if (G_flag_return_in_progress == 1) {
8345 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8348 } else if (pi->followup == PIPE_BG) {
8349 /* What does bash do with attempts to background builtins? */
8350 /* even bash 3.2 doesn't do that well with nested bg:
8351 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8352 * I'm NOT treating inner &'s as jobs */
8354 if (G.run_list_level == 1)
8355 insert_job_into_table(pi);
8357 /* Last command's pid goes to $! */
8358 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8359 G.last_bg_pid_exitcode = 0;
8360 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8361 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8362 rcode = EXIT_SUCCESS;
8366 if (G.run_list_level == 1 && G_interactive_fd) {
8367 /* Waits for completion, then fg's main shell */
8368 rcode = checkjobs_and_fg_shell(pi);
8369 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8373 /* This one just waits for completion */
8374 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8375 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8377 G.last_exitcode = rcode;
8378 check_and_run_traps();
8381 /* Handle "set -e" */
8382 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8383 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8384 if (G.errexit_depth == 0)
8387 G.errexit_depth = sv_errexit_depth;
8389 /* Analyze how result affects subsequent commands */
8391 if (rword == RES_IF || rword == RES_ELIF)
8394 check_jobs_and_continue:
8395 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8396 dont_check_jobs_but_continue: ;
8397 #if ENABLE_HUSH_LOOPS
8398 /* Beware of "while false; true; do ..."! */
8400 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8401 /* check for RES_DONE is needed for "while ...; do \n done" case */
8403 if (rword == RES_WHILE) {
8405 /* "while false; do...done" - exitcode 0 */
8406 G.last_exitcode = rcode = EXIT_SUCCESS;
8407 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8411 if (rword == RES_UNTIL) {
8413 debug_printf_exec(": until expr is true: breaking\n");
8424 #if ENABLE_HUSH_LOOPS
8429 #if ENABLE_HUSH_CASE
8433 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8437 /* Select which version we will use */
8438 static int run_and_free_list(struct pipe *pi)
8441 debug_printf_exec("run_and_free_list entered\n");
8442 if (!G.o_opt[OPT_O_NOEXEC]) {
8443 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8444 rcode = run_list(pi);
8446 /* free_pipe_list has the side effect of clearing memory.
8447 * In the long run that function can be merged with run_list,
8448 * but doing that now would hobble the debugging effort. */
8450 debug_printf_exec("run_and_free_list return %d\n", rcode);
8455 static void install_sighandlers(unsigned mask)
8457 sighandler_t old_handler;
8459 while ((mask >>= 1) != 0) {
8463 old_handler = install_sighandler(sig, pick_sighandler(sig));
8464 /* POSIX allows shell to re-enable SIGCHLD
8465 * even if it was SIG_IGN on entry.
8466 * Therefore we skip IGN check for it:
8470 if (old_handler == SIG_IGN) {
8471 /* oops... restore back to IGN, and record this fact */
8472 install_sighandler(sig, old_handler);
8473 #if ENABLE_HUSH_TRAP
8475 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8477 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8483 /* Called a few times only (or even once if "sh -c") */
8484 static void install_special_sighandlers(void)
8488 /* Which signals are shell-special? */
8489 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8490 if (G_interactive_fd) {
8491 mask |= SPECIAL_INTERACTIVE_SIGS;
8492 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8493 mask |= SPECIAL_JOBSTOP_SIGS;
8495 /* Careful, do not re-install handlers we already installed */
8496 if (G.special_sig_mask != mask) {
8497 unsigned diff = mask & ~G.special_sig_mask;
8498 G.special_sig_mask = mask;
8499 install_sighandlers(diff);
8505 /* Set handlers to restore tty pgrp and exit */
8506 static void install_fatal_sighandlers(void)
8510 /* We will restore tty pgrp on these signals */
8512 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8513 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8514 + (1 << SIGBUS ) * HUSH_DEBUG
8515 + (1 << SIGSEGV) * HUSH_DEBUG
8516 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8518 /* bash 3.2 seems to handle these just like 'fatal' ones */
8521 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8522 * if we aren't interactive... but in this case
8523 * we never want to restore pgrp on exit, and this fn is not called
8525 /*+ (1 << SIGHUP )*/
8526 /*+ (1 << SIGTERM)*/
8527 /*+ (1 << SIGINT )*/
8529 G_fatal_sig_mask = mask;
8531 install_sighandlers(mask);
8535 static int set_mode(int state, char mode, const char *o_opt)
8540 G.o_opt[OPT_O_NOEXEC] = state;
8543 IF_HUSH_MODE_X(G_x_mode = state;)
8547 /* "set -+o" without parameter.
8548 * in bash, set -o produces this output:
8552 * We always use the second form.
8554 const char *p = o_opt_strings;
8557 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8563 idx = index_in_strings(o_opt_strings, o_opt);
8565 G.o_opt[idx] = state;
8569 G.o_opt[OPT_O_ERREXIT] = state;
8572 return EXIT_FAILURE;
8574 return EXIT_SUCCESS;
8577 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8578 int hush_main(int argc, char **argv)
8581 OPT_login = (1 << 0),
8585 unsigned builtin_argc;
8587 struct variable *cur_var;
8588 struct variable *shell_ver;
8591 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8592 G.last_exitcode = EXIT_SUCCESS;
8594 #if ENABLE_HUSH_FAST
8595 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8598 G.argv0_for_re_execing = argv[0];
8600 /* Deal with HUSH_VERSION */
8601 shell_ver = xzalloc(sizeof(*shell_ver));
8602 shell_ver->flg_export = 1;
8603 shell_ver->flg_read_only = 1;
8604 /* Code which handles ${var<op>...} needs writable values for all variables,
8605 * therefore we xstrdup: */
8606 shell_ver->varstr = xstrdup(hush_version_str);
8607 /* Create shell local variables from the values
8608 * currently living in the environment */
8609 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8610 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8611 G.top_var = shell_ver;
8612 cur_var = G.top_var;
8615 char *value = strchr(*e, '=');
8616 if (value) { /* paranoia */
8617 cur_var->next = xzalloc(sizeof(*cur_var));
8618 cur_var = cur_var->next;
8619 cur_var->varstr = *e;
8620 cur_var->max_len = strlen(*e);
8621 cur_var->flg_export = 1;
8625 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8626 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8627 putenv(shell_ver->varstr);
8630 set_pwd_var(SETFLAG_EXPORT);
8632 #if BASH_HOSTNAME_VAR
8633 /* Set (but not export) HOSTNAME unless already set */
8634 if (!get_local_var_value("HOSTNAME")) {
8637 set_local_var_from_halves("HOSTNAME", uts.nodename);
8639 /* bash also exports SHLVL and _,
8640 * and sets (but doesn't export) the following variables:
8642 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8643 * BASH_VERSION='3.2.0(1)-release'
8645 * MACHTYPE=i386-pc-linux-gnu
8647 * PPID=<NNNNN> - we also do it elsewhere
8658 * PIPESTATUS=([0]="0")
8659 * HISTFILE=/<xxx>/.bash_history
8663 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8665 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8676 #if ENABLE_FEATURE_EDITING
8677 G.line_input_state = new_line_input_t(FOR_SHELL);
8680 /* Initialize some more globals to non-zero values */
8681 cmdedit_update_prompt();
8683 die_func = restore_ttypgrp_and__exit;
8685 /* Shell is non-interactive at first. We need to call
8686 * install_special_sighandlers() if we are going to execute "sh <script>",
8687 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8688 * If we later decide that we are interactive, we run install_special_sighandlers()
8689 * in order to intercept (more) signals.
8693 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8694 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8697 opt = getopt(argc, argv, "+c:exinsl"
8700 # if ENABLE_HUSH_FUNCTIONS
8710 * sh ... -c 'script'
8711 * sh ... -c 'script' ARG0 [ARG1...]
8712 * On NOMMU, if builtin_argc != 0,
8713 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8714 * "" needs to be replaced with NULL
8715 * and BARGV vector fed to builtin function.
8716 * Note: the form without ARG0 never happens:
8717 * sh ... -c 'builtin' BARGV... ""
8720 G.root_pid = getpid();
8721 G.root_ppid = getppid();
8723 G.global_argv = argv + optind;
8724 G.global_argc = argc - optind;
8726 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8727 const struct built_in_command *x;
8729 install_special_sighandlers();
8730 x = find_builtin(optarg);
8731 if (x) { /* paranoia */
8732 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8733 G.global_argv += builtin_argc;
8734 G.global_argv[-1] = NULL; /* replace "" */
8736 G.last_exitcode = x->b_function(argv + optind - 1);
8740 if (!G.global_argv[0]) {
8741 /* -c 'script' (no params): prevent empty $0 */
8742 G.global_argv--; /* points to argv[i] of 'script' */
8743 G.global_argv[0] = argv[0];
8745 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8746 install_special_sighandlers();
8747 parse_and_run_string(optarg);
8750 /* Well, we cannot just declare interactiveness,
8751 * we have to have some stuff (ctty, etc) */
8752 /* G_interactive_fd++; */
8755 /* "-s" means "read from stdin", but this is how we always
8756 * operate, so simply do nothing here. */
8762 case '<': /* "big heredoc" support */
8763 full_write1_str(optarg);
8766 unsigned long long empty_trap_mask;
8768 G.root_pid = bb_strtou(optarg, &optarg, 16);
8770 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8772 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8774 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8776 builtin_argc = bb_strtou(optarg, &optarg, 16);
8778 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8779 if (empty_trap_mask != 0) {
8780 IF_HUSH_TRAP(int sig;)
8781 install_special_sighandlers();
8782 # if ENABLE_HUSH_TRAP
8783 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8784 for (sig = 1; sig < NSIG; sig++) {
8785 if (empty_trap_mask & (1LL << sig)) {
8786 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8787 install_sighandler(sig, SIG_IGN);
8792 # if ENABLE_HUSH_LOOPS
8794 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8800 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8802 # if ENABLE_HUSH_FUNCTIONS
8804 struct function *funcp = new_function(optarg);
8805 /* funcp->name is already set to optarg */
8806 /* funcp->body is set to NULL. It's a special case. */
8807 funcp->body_as_string = argv[optind];
8816 if (set_mode(1, opt, NULL) == 0) /* no error */
8820 fprintf(stderr, "Usage: sh [FILE]...\n"
8821 " or: sh -c command [args]...\n\n");
8827 } /* option parsing loop */
8829 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8830 G.global_argc = argc - (optind - 1);
8831 G.global_argv = argv + (optind - 1);
8832 G.global_argv[0] = argv[0];
8835 G.root_pid = getpid();
8836 G.root_ppid = getppid();
8839 /* If we are login shell... */
8840 if (flags & OPT_login) {
8842 debug_printf("sourcing /etc/profile\n");
8843 input = fopen_for_read("/etc/profile");
8844 if (input != NULL) {
8845 remember_FILE(input);
8846 install_special_sighandlers();
8847 parse_and_run_file(input);
8848 fclose_and_forget(input);
8850 /* bash: after sourcing /etc/profile,
8851 * tries to source (in the given order):
8852 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8853 * stopping on first found. --noprofile turns this off.
8854 * bash also sources ~/.bash_logout on exit.
8855 * If called as sh, skips .bash_XXX files.
8859 if (G.global_argv[1]) {
8862 * "bash <script>" (which is never interactive (unless -i?))
8863 * sources $BASH_ENV here (without scanning $PATH).
8864 * If called as sh, does the same but with $ENV.
8865 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8869 debug_printf("running script '%s'\n", G.global_argv[0]);
8870 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8871 input = xfopen_for_read(G.global_argv[0]);
8872 xfunc_error_retval = 1;
8873 remember_FILE(input);
8874 install_special_sighandlers();
8875 parse_and_run_file(input);
8876 #if ENABLE_FEATURE_CLEAN_UP
8877 fclose_and_forget(input);
8882 /* Up to here, shell was non-interactive. Now it may become one.
8883 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8886 /* A shell is interactive if the '-i' flag was given,
8887 * or if all of the following conditions are met:
8889 * no arguments remaining or the -s flag given
8890 * standard input is a terminal
8891 * standard output is a terminal
8892 * Refer to Posix.2, the description of the 'sh' utility.
8895 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8896 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8897 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8898 if (G_saved_tty_pgrp < 0)
8899 G_saved_tty_pgrp = 0;
8901 /* try to dup stdin to high fd#, >= 255 */
8902 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8903 if (G_interactive_fd < 0) {
8904 /* try to dup to any fd */
8905 G_interactive_fd = dup(STDIN_FILENO);
8906 if (G_interactive_fd < 0) {
8908 G_interactive_fd = 0;
8909 G_saved_tty_pgrp = 0;
8912 // TODO: track & disallow any attempts of user
8913 // to (inadvertently) close/redirect G_interactive_fd
8915 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8916 if (G_interactive_fd) {
8917 close_on_exec_on(G_interactive_fd);
8919 if (G_saved_tty_pgrp) {
8920 /* If we were run as 'hush &', sleep until we are
8921 * in the foreground (tty pgrp == our pgrp).
8922 * If we get started under a job aware app (like bash),
8923 * make sure we are now in charge so we don't fight over
8924 * who gets the foreground */
8926 pid_t shell_pgrp = getpgrp();
8927 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8928 if (G_saved_tty_pgrp == shell_pgrp)
8930 /* send TTIN to ourself (should stop us) */
8931 kill(- shell_pgrp, SIGTTIN);
8935 /* Install more signal handlers */
8936 install_special_sighandlers();
8938 if (G_saved_tty_pgrp) {
8939 /* Set other signals to restore saved_tty_pgrp */
8940 install_fatal_sighandlers();
8941 /* Put ourselves in our own process group
8942 * (bash, too, does this only if ctty is available) */
8943 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8944 /* Grab control of the terminal */
8945 tcsetpgrp(G_interactive_fd, getpid());
8947 enable_restore_tty_pgrp_on_exit();
8949 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8951 const char *hp = get_local_var_value("HISTFILE");
8953 hp = get_local_var_value("HOME");
8955 hp = concat_path_file(hp, ".hush_history");
8960 G.line_input_state->hist_file = hp;
8961 //set_local_var(xasprintf("HISTFILE=%s", ...));
8963 # if ENABLE_FEATURE_SH_HISTFILESIZE
8964 hp = get_local_var_value("HISTFILESIZE");
8965 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8970 install_special_sighandlers();
8972 #elif ENABLE_HUSH_INTERACTIVE
8973 /* No job control compiled in, only prompt/line editing */
8974 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8975 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
8976 if (G_interactive_fd < 0) {
8977 /* try to dup to any fd */
8978 G_interactive_fd = dup(STDIN_FILENO);
8979 if (G_interactive_fd < 0)
8981 G_interactive_fd = 0;
8984 if (G_interactive_fd) {
8985 close_on_exec_on(G_interactive_fd);
8987 install_special_sighandlers();
8989 /* We have interactiveness code disabled */
8990 install_special_sighandlers();
8993 * if interactive but not a login shell, sources ~/.bashrc
8994 * (--norc turns this off, --rcfile <file> overrides)
8997 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8998 /* note: ash and hush share this string */
8999 printf("\n\n%s %s\n"
9000 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9003 "hush - the humble shell"
9007 parse_and_run_file(stdin);
9010 hush_exit(G.last_exitcode);
9017 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9022 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9023 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9025 int argc = string_array_len(argv);
9026 return applet_main_func(argc, argv);
9029 #if ENABLE_HUSH_TEST || BASH_TEST2
9030 static int FAST_FUNC builtin_test(char **argv)
9032 return run_applet_main(argv, test_main);
9035 #if ENABLE_HUSH_ECHO
9036 static int FAST_FUNC builtin_echo(char **argv)
9038 return run_applet_main(argv, echo_main);
9041 #if ENABLE_HUSH_PRINTF
9042 static int FAST_FUNC builtin_printf(char **argv)
9044 return run_applet_main(argv, printf_main);
9048 #if ENABLE_HUSH_HELP
9049 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9051 const struct built_in_command *x;
9054 "Built-in commands:\n"
9055 "------------------\n");
9056 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9058 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9060 return EXIT_SUCCESS;
9064 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9065 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9067 show_history(G.line_input_state);
9068 return EXIT_SUCCESS;
9072 static char **skip_dash_dash(char **argv)
9075 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9080 static int FAST_FUNC builtin_cd(char **argv)
9084 argv = skip_dash_dash(argv);
9086 if (newdir == NULL) {
9087 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9088 * bash says "bash: cd: HOME not set" and does nothing
9091 const char *home = get_local_var_value("HOME");
9092 newdir = home ? home : "/";
9094 if (chdir(newdir)) {
9095 /* Mimic bash message exactly */
9096 bb_perror_msg("cd: %s", newdir);
9097 return EXIT_FAILURE;
9099 /* Read current dir (get_cwd(1) is inside) and set PWD.
9100 * Note: do not enforce exporting. If PWD was unset or unexported,
9101 * set it again, but do not export. bash does the same.
9103 set_pwd_var(/*flag:*/ 0);
9104 return EXIT_SUCCESS;
9107 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9110 return EXIT_SUCCESS;
9113 static int FAST_FUNC builtin_eval(char **argv)
9115 int rcode = EXIT_SUCCESS;
9117 argv = skip_dash_dash(argv);
9119 char *str = expand_strvec_to_string(argv);
9121 * eval "echo Hi; done" ("done" is syntax error):
9122 * "echo Hi" will not execute too.
9124 parse_and_run_string(str);
9126 rcode = G.last_exitcode;
9131 static int FAST_FUNC builtin_exec(char **argv)
9133 argv = skip_dash_dash(argv);
9134 if (argv[0] == NULL)
9135 return EXIT_SUCCESS; /* bash does this */
9137 /* Careful: we can end up here after [v]fork. Do not restore
9138 * tty pgrp then, only top-level shell process does that */
9139 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9140 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9142 /* TODO: if exec fails, bash does NOT exit! We do.
9143 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9144 * and tcsetpgrp, and this is inherently racy.
9146 execvp_or_die(argv);
9149 static int FAST_FUNC builtin_exit(char **argv)
9151 debug_printf_exec("%s()\n", __func__);
9153 /* interactive bash:
9154 * # trap "echo EEE" EXIT
9157 * There are stopped jobs.
9158 * (if there are _stopped_ jobs, running ones don't count)
9161 * EEE (then bash exits)
9163 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9166 /* note: EXIT trap is run by hush_exit */
9167 argv = skip_dash_dash(argv);
9168 if (argv[0] == NULL)
9169 hush_exit(G.last_exitcode);
9170 /* mimic bash: exit 123abc == exit 255 + error msg */
9171 xfunc_error_retval = 255;
9172 /* bash: exit -2 == exit 254, no error msg */
9173 hush_exit(xatoi(argv[0]) & 0xff);
9176 #if ENABLE_HUSH_TYPE
9177 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9178 static int FAST_FUNC builtin_type(char **argv)
9180 int ret = EXIT_SUCCESS;
9186 if (0) {} /* make conditional compile easier below */
9187 /*else if (find_alias(*argv))
9188 type = "an alias";*/
9189 #if ENABLE_HUSH_FUNCTIONS
9190 else if (find_function(*argv))
9191 type = "a function";
9193 else if (find_builtin(*argv))
9194 type = "a shell builtin";
9195 else if ((path = find_in_path(*argv)) != NULL)
9198 bb_error_msg("type: %s: not found", *argv);
9203 printf("%s is %s\n", *argv, type);
9211 #if ENABLE_HUSH_READ
9212 /* Interruptibility of read builtin in bash
9213 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9215 * Empty trap makes read ignore corresponding signal, for any signal.
9218 * - terminates non-interactive shell;
9219 * - interrupts read in interactive shell;
9220 * if it has non-empty trap:
9221 * - executes trap and returns to command prompt in interactive shell;
9222 * - executes trap and returns to read in non-interactive shell;
9224 * - is ignored (does not interrupt) read in interactive shell;
9225 * - terminates non-interactive shell;
9226 * if it has non-empty trap:
9227 * - executes trap and returns to read;
9229 * - terminates shell (regardless of interactivity);
9230 * if it has non-empty trap:
9231 * - executes trap and returns to read;
9232 * SIGCHLD from children:
9233 * - does not interrupt read regardless of interactivity:
9234 * try: sleep 1 & read x; echo $x
9236 static int FAST_FUNC builtin_read(char **argv)
9246 /* "!": do not abort on errors.
9247 * Option string must start with "sr" to match BUILTIN_READ_xxx
9249 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9250 if (read_flags == (uint32_t)-1)
9251 return EXIT_FAILURE;
9253 ifs = get_local_var_value("IFS"); /* can be NULL */
9256 r = shell_builtin_read(set_local_var_from_halves,
9266 if ((uintptr_t)r == 1 && errno == EINTR) {
9267 unsigned sig = check_and_run_traps();
9272 if ((uintptr_t)r > 1) {
9273 bb_error_msg("%s", r);
9274 r = (char*)(uintptr_t)1;
9277 return (uintptr_t)r;
9281 #if ENABLE_HUSH_UMASK
9282 static int FAST_FUNC builtin_umask(char **argv)
9289 argv = skip_dash_dash(argv);
9291 mode_t old_mask = mask;
9293 /* numeric umasks are taken as-is */
9294 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9295 if (!isdigit(argv[0][0]))
9297 mask = bb_parse_mode(argv[0], mask);
9298 if (!isdigit(argv[0][0]))
9300 if ((unsigned)mask > 0777) {
9303 * bash: umask: 'q': invalid symbolic mode operator
9304 * bash: umask: 999: octal number out of range
9306 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9311 printf("%04o\n", (unsigned) mask);
9312 /* fall through and restore mask which we set to 0 */
9316 return !rc; /* rc != 0 - success */
9320 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9321 static void print_escaped(const char *s)
9326 const char *p = strchrnul(s, '\'');
9327 /* print 'xxxx', possibly just '' */
9328 printf("'%.*s'", (int)(p - s), s);
9333 /* s points to '; print "'''...'''" */
9335 do putchar('\''); while (*++s == '\'');
9341 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9342 static int helper_export_local(char **argv, unsigned flags)
9346 char *name_end = strchrnul(name, '=');
9348 /* So far we do not check that name is valid (TODO?) */
9350 if (*name_end == '\0') {
9351 struct variable *var, **vpp;
9353 vpp = get_ptr_to_local_var(name, name_end - name);
9354 var = vpp ? *vpp : NULL;
9356 if (flags & SETFLAG_UNEXPORT) {
9357 /* export -n NAME (without =VALUE) */
9359 var->flg_export = 0;
9360 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9362 } /* else: export -n NOT_EXISTING_VAR: no-op */
9365 if (flags & SETFLAG_EXPORT) {
9366 /* export NAME (without =VALUE) */
9368 var->flg_export = 1;
9369 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9370 putenv(var->varstr);
9374 if (flags & SETFLAG_MAKE_RO) {
9375 /* readonly NAME (without =VALUE) */
9377 var->flg_read_only = 1;
9381 # if ENABLE_HUSH_LOCAL
9382 /* Is this "local" bltin? */
9383 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9384 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9385 if (var && var->func_nest_level == lvl) {
9386 /* "local x=abc; ...; local x" - ignore second local decl */
9391 /* Exporting non-existing variable.
9392 * bash does not put it in environment,
9393 * but remembers that it is exported,
9394 * and does put it in env when it is set later.
9395 * We just set it to "" and export.
9397 /* Or, it's "local NAME" (without =VALUE).
9398 * bash sets the value to "".
9400 /* Or, it's "readonly NAME" (without =VALUE).
9401 * bash remembers NAME and disallows its creation
9404 name = xasprintf("%s=", name);
9406 /* (Un)exporting/making local NAME=VALUE */
9407 name = xstrdup(name);
9409 if (set_local_var(name, flags))
9410 return EXIT_FAILURE;
9412 return EXIT_SUCCESS;
9416 #if ENABLE_HUSH_EXPORT
9417 static int FAST_FUNC builtin_export(char **argv)
9419 unsigned opt_unexport;
9421 #if ENABLE_HUSH_EXPORT_N
9422 /* "!": do not abort on errors */
9423 opt_unexport = getopt32(argv, "!n");
9424 if (opt_unexport == (uint32_t)-1)
9425 return EXIT_FAILURE;
9432 if (argv[0] == NULL) {
9439 /* ash emits: export VAR='VAL'
9440 * bash: declare -x VAR="VAL"
9441 * we follow ash example */
9442 const char *s = *e++;
9443 const char *p = strchr(s, '=');
9445 if (!p) /* wtf? take next variable */
9448 printf("export %.*s", (int)(p - s) + 1, s);
9449 print_escaped(p + 1);
9453 /*fflush_all(); - done after each builtin anyway */
9455 return EXIT_SUCCESS;
9458 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9462 #if ENABLE_HUSH_LOCAL
9463 static int FAST_FUNC builtin_local(char **argv)
9465 if (G.func_nest_level == 0) {
9466 bb_error_msg("%s: not in a function", argv[0]);
9467 return EXIT_FAILURE; /* bash compat */
9470 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9474 #if ENABLE_HUSH_READONLY
9475 static int FAST_FUNC builtin_readonly(char **argv)
9478 if (*argv == NULL) {
9479 /* bash: readonly [-p]: list all readonly VARs
9480 * (-p has no effect in bash)
9483 for (e = G.top_var; e; e = e->next) {
9484 if (e->flg_read_only) {
9485 //TODO: quote value: readonly VAR='VAL'
9486 printf("readonly %s\n", e->varstr);
9489 return EXIT_SUCCESS;
9491 return helper_export_local(argv, SETFLAG_MAKE_RO);
9495 #if ENABLE_HUSH_UNSET
9496 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9497 static int FAST_FUNC builtin_unset(char **argv)
9502 /* "!": do not abort on errors */
9503 /* "+": stop at 1st non-option */
9504 opts = getopt32(argv, "!+vf");
9505 if (opts == (unsigned)-1)
9506 return EXIT_FAILURE;
9508 bb_error_msg("unset: -v and -f are exclusive");
9509 return EXIT_FAILURE;
9515 if (!(opts & 2)) { /* not -f */
9516 if (unset_local_var(*argv)) {
9517 /* unset <nonexistent_var> doesn't fail.
9518 * Error is when one tries to unset RO var.
9519 * Message was printed by unset_local_var. */
9523 # if ENABLE_HUSH_FUNCTIONS
9535 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9536 * built-in 'set' handler
9538 * set [-abCefhmnuvx] [-o option] [argument...]
9539 * set [+abCefhmnuvx] [+o option] [argument...]
9540 * set -- [argument...]
9543 * Implementations shall support the options in both their hyphen and
9544 * plus-sign forms. These options can also be specified as options to sh.
9546 * Write out all variables and their values: set
9547 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9548 * Turn on the -x and -v options: set -xv
9549 * Unset all positional parameters: set --
9550 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9551 * Set the positional parameters to the expansion of x, even if x expands
9552 * with a leading '-' or '+': set -- $x
9554 * So far, we only support "set -- [argument...]" and some of the short names.
9556 static int FAST_FUNC builtin_set(char **argv)
9559 char **pp, **g_argv;
9560 char *arg = *++argv;
9564 for (e = G.top_var; e; e = e->next)
9566 return EXIT_SUCCESS;
9570 if (strcmp(arg, "--") == 0) {
9574 if (arg[0] != '+' && arg[0] != '-')
9576 for (n = 1; arg[n]; ++n) {
9577 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9579 if (arg[n] == 'o' && argv[1])
9582 } while ((arg = *++argv) != NULL);
9583 /* Now argv[0] is 1st argument */
9586 return EXIT_SUCCESS;
9589 /* NB: G.global_argv[0] ($0) is never freed/changed */
9590 g_argv = G.global_argv;
9591 if (G.global_args_malloced) {
9597 G.global_args_malloced = 1;
9598 pp = xzalloc(sizeof(pp[0]) * 2);
9599 pp[0] = g_argv[0]; /* retain $0 */
9602 /* This realloc's G.global_argv */
9603 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9605 G.global_argc = 1 + string_array_len(pp + 1);
9607 return EXIT_SUCCESS;
9609 /* Nothing known, so abort */
9611 bb_error_msg("set: %s: invalid option", arg);
9612 return EXIT_FAILURE;
9616 static int FAST_FUNC builtin_shift(char **argv)
9619 argv = skip_dash_dash(argv);
9621 n = bb_strtou(argv[0], NULL, 10);
9622 if (errno || n < 0) {
9623 /* shared string with ash.c */
9624 bb_error_msg("Illegal number: %s", argv[0]);
9626 * ash aborts in this case.
9627 * bash prints error message and set $? to 1.
9628 * Interestingly, for "shift 99999" bash does not
9629 * print error message, but does set $? to 1
9630 * (and does no shifting at all).
9634 if (n >= 0 && n < G.global_argc) {
9635 if (G_global_args_malloced) {
9638 free(G.global_argv[m++]);
9641 memmove(&G.global_argv[1], &G.global_argv[n+1],
9642 G.global_argc * sizeof(G.global_argv[0]));
9643 return EXIT_SUCCESS;
9645 return EXIT_FAILURE;
9648 static int FAST_FUNC builtin_source(char **argv)
9650 char *arg_path, *filename;
9653 char *args_need_save;
9654 #if ENABLE_HUSH_FUNCTIONS
9658 argv = skip_dash_dash(argv);
9661 /* bash says: "bash: .: filename argument required" */
9662 return 2; /* bash compat */
9665 if (!strchr(filename, '/')) {
9666 arg_path = find_in_path(filename);
9668 filename = arg_path;
9670 input = remember_FILE(fopen_or_warn(filename, "r"));
9673 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9674 /* POSIX: non-interactive shell should abort here,
9675 * not merely fail. So far no one complained :)
9677 return EXIT_FAILURE;
9680 #if ENABLE_HUSH_FUNCTIONS
9681 sv_flg = G_flag_return_in_progress;
9682 /* "we are inside sourced file, ok to use return" */
9683 G_flag_return_in_progress = -1;
9685 args_need_save = argv[1]; /* used as a boolean variable */
9687 save_and_replace_G_args(&sv, argv);
9689 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9690 G.last_exitcode = 0;
9691 parse_and_run_file(input);
9692 fclose_and_forget(input);
9694 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9695 restore_G_args(&sv, argv);
9696 #if ENABLE_HUSH_FUNCTIONS
9697 G_flag_return_in_progress = sv_flg;
9700 return G.last_exitcode;
9703 #if ENABLE_HUSH_TRAP
9704 static int FAST_FUNC builtin_trap(char **argv)
9710 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9715 /* No args: print all trapped */
9716 for (i = 0; i < NSIG; ++i) {
9719 print_escaped(G_traps[i]);
9720 /* note: bash adds "SIG", but only if invoked
9721 * as "bash". If called as "sh", or if set -o posix,
9722 * then it prints short signal names.
9723 * We are printing short names: */
9724 printf(" %s\n", get_signame(i));
9727 /*fflush_all(); - done after each builtin anyway */
9728 return EXIT_SUCCESS;
9732 /* If first arg is a number: reset all specified signals */
9733 sig = bb_strtou(*argv, NULL, 10);
9739 sighandler_t handler;
9741 sig = get_signum(*argv++);
9742 if (sig < 0 || sig >= NSIG) {
9744 /* Mimic bash message exactly */
9745 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9750 G_traps[sig] = xstrdup(new_cmd);
9752 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9753 get_signame(sig), sig, G_traps[sig]);
9755 /* There is no signal for 0 (EXIT) */
9760 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9762 /* We are removing trap handler */
9763 handler = pick_sighandler(sig);
9764 install_sighandler(sig, handler);
9769 if (!argv[1]) { /* no second arg */
9770 bb_error_msg("trap: invalid arguments");
9771 return EXIT_FAILURE;
9774 /* First arg is "-": reset all specified to default */
9775 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9776 /* Everything else: set arg as signal handler
9777 * (includes "" case, which ignores signal) */
9778 if (argv[0][0] == '-') {
9779 if (argv[0][1] == '\0') { /* "-" */
9780 /* new_cmd remains NULL: "reset these sigs" */
9783 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9786 /* else: "-something", no special meaning */
9791 goto process_sig_list;
9796 static struct pipe *parse_jobspec(const char *str)
9801 if (sscanf(str, "%%%u", &jobnum) != 1) {
9803 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9805 bb_error_msg("bad argument '%s'", str);
9808 /* It is "%%", "%+" or "%" - current job */
9809 jobnum = G.last_jobid;
9811 bb_error_msg("no current job");
9815 for (pi = G.job_list; pi; pi = pi->next) {
9816 if (pi->jobid == jobnum) {
9820 bb_error_msg("%u: no such job", jobnum);
9824 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9827 const char *status_string;
9829 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9830 for (job = G.job_list; job; job = job->next) {
9831 if (job->alive_cmds == job->stopped_cmds)
9832 status_string = "Stopped";
9834 status_string = "Running";
9836 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9839 clean_up_last_dead_job();
9841 return EXIT_SUCCESS;
9844 /* built-in 'fg' and 'bg' handler */
9845 static int FAST_FUNC builtin_fg_bg(char **argv)
9850 if (!G_interactive_fd)
9851 return EXIT_FAILURE;
9853 /* If they gave us no args, assume they want the last backgrounded task */
9855 for (pi = G.job_list; pi; pi = pi->next) {
9856 if (pi->jobid == G.last_jobid) {
9860 bb_error_msg("%s: no current job", argv[0]);
9861 return EXIT_FAILURE;
9864 pi = parse_jobspec(argv[1]);
9866 return EXIT_FAILURE;
9868 /* TODO: bash prints a string representation
9869 * of job being foregrounded (like "sleep 1 | cat") */
9870 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9871 /* Put the job into the foreground. */
9872 tcsetpgrp(G_interactive_fd, pi->pgrp);
9875 /* Restart the processes in the job */
9876 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9877 for (i = 0; i < pi->num_cmds; i++) {
9878 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9880 pi->stopped_cmds = 0;
9882 i = kill(- pi->pgrp, SIGCONT);
9884 if (errno == ESRCH) {
9885 delete_finished_job(pi);
9886 return EXIT_SUCCESS;
9888 bb_perror_msg("kill (SIGCONT)");
9891 if (argv[0][0] == 'f') {
9892 remove_job_from_table(pi); /* FG job shouldn't be in job table */
9893 return checkjobs_and_fg_shell(pi);
9895 return EXIT_SUCCESS;
9899 #if ENABLE_HUSH_KILL
9900 static int FAST_FUNC builtin_kill(char **argv)
9904 # if ENABLE_HUSH_JOB
9905 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9913 if (argv[i][0] != '%')
9916 * "kill %N" - job kill
9917 * Converting to pgrp / pid kill
9919 pi = parse_jobspec(argv[i]);
9921 /* Eat bad jobspec */
9925 argv[j - 1] = argv[j];
9932 * In jobs started under job control, we signal
9933 * entire process group by kill -PGRP_ID.
9934 * This happens, f.e., in interactive shell.
9936 * Otherwise, we signal each child via
9937 * kill PID1 PID2 PID3.
9939 * sh -c 'sleep 1|sleep 1 & kill %1'
9940 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9941 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9943 n = G_interactive_fd ? 1 : pi->num_cmds;
9944 dst = alloca(n * sizeof(int)*4);
9946 if (G_interactive_fd)
9947 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9948 else for (j = 0; j < n; j++) {
9949 struct command *cmd = &pi->cmds[j];
9950 /* Skip exited members of the job */
9954 * kill_main has matching code to expect
9955 * leading space. Needed to not confuse
9956 * negative pids with "kill -SIGNAL_NO" syntax
9958 dst += sprintf(dst, " %u", (int)cmd->pid);
9961 } while (argv[++i]);
9965 if (argv[1] || ret == 0) {
9966 ret = run_applet_main(argv, kill_main);
9968 /* else: ret = 1, "kill %bad_jobspec" case */
9973 #if ENABLE_HUSH_WAIT
9974 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9975 #if !ENABLE_HUSH_JOB
9976 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9978 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9985 if (!sigisemptyset(&G.pending_set))
9988 /* waitpid is not interruptible by SA_RESTARTed
9989 * signals which we use. Thus, this ugly dance:
9992 /* Make sure possible SIGCHLD is stored in kernel's
9993 * pending signal mask before we call waitpid.
9994 * Or else we may race with SIGCHLD, lose it,
9995 * and get stuck in sigsuspend...
9997 sigfillset(&oldset); /* block all signals, remember old set */
9998 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10000 if (!sigisemptyset(&G.pending_set)) {
10001 /* Crap! we raced with some signal! */
10005 /*errno = 0; - checkjobs does this */
10006 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10007 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10008 debug_printf_exec("checkjobs:%d\n", ret);
10009 #if ENABLE_HUSH_JOB
10010 if (waitfor_pipe) {
10011 int rcode = job_exited_or_stopped(waitfor_pipe);
10012 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10015 sigprocmask(SIG_SETMASK, &oldset, NULL);
10020 /* if ECHILD, there are no children (ret is -1 or 0) */
10021 /* if ret == 0, no children changed state */
10022 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10023 if (errno == ECHILD || ret) {
10025 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10027 sigprocmask(SIG_SETMASK, &oldset, NULL);
10030 /* Wait for SIGCHLD or any other signal */
10031 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10032 /* Note: sigsuspend invokes signal handler */
10033 sigsuspend(&oldset);
10035 sigprocmask(SIG_SETMASK, &oldset, NULL);
10037 /* So, did we get a signal? */
10038 sig = check_and_run_traps();
10039 if (sig /*&& sig != SIGCHLD - always true */) {
10043 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10048 static int FAST_FUNC builtin_wait(char **argv)
10053 argv = skip_dash_dash(argv);
10054 if (argv[0] == NULL) {
10055 /* Don't care about wait results */
10056 /* Note 1: must wait until there are no more children */
10057 /* Note 2: must be interruptible */
10059 * $ sleep 3 & sleep 6 & wait
10060 * [1] 30934 sleep 3
10061 * [2] 30935 sleep 6
10064 * $ sleep 3 & sleep 6 & wait
10065 * [1] 30936 sleep 3
10066 * [2] 30937 sleep 6
10068 * ^C <-- after ~4 sec from keyboard
10071 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10075 pid_t pid = bb_strtou(*argv, NULL, 10);
10076 if (errno || pid <= 0) {
10077 #if ENABLE_HUSH_JOB
10078 if (argv[0][0] == '%') {
10079 struct pipe *wait_pipe;
10080 ret = 127; /* bash compat for bad jobspecs */
10081 wait_pipe = parse_jobspec(*argv);
10083 ret = job_exited_or_stopped(wait_pipe);
10085 ret = wait_for_child_or_signal(wait_pipe, 0);
10087 /* waiting on "last dead job" removes it */
10088 clean_up_last_dead_job();
10091 /* else: parse_jobspec() already emitted error msg */
10095 /* mimic bash message */
10096 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10097 ret = EXIT_FAILURE;
10098 continue; /* bash checks all argv[] */
10101 /* Do we have such child? */
10102 ret = waitpid(pid, &status, WNOHANG);
10106 if (errno == ECHILD) {
10107 if (pid == G.last_bg_pid) {
10108 /* "wait $!" but last bg task has already exited. Try:
10109 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10110 * In bash it prints exitcode 0, then 3.
10111 * In dash, it is 127.
10113 ret = G.last_bg_pid_exitcode;
10115 /* Example: "wait 1". mimic bash message */
10116 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10120 bb_perror_msg("wait %s", *argv);
10122 continue; /* bash checks all argv[] */
10125 /* Yes, and it still runs */
10126 ret = wait_for_child_or_signal(NULL, pid);
10128 /* Yes, and it just exited */
10129 process_wait_result(NULL, pid, status);
10130 ret = WEXITSTATUS(status);
10131 if (WIFSIGNALED(status))
10132 ret = 128 + WTERMSIG(status);
10140 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10141 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10144 def = bb_strtou(argv[1], NULL, 10);
10145 if (errno || def < def_min || argv[2]) {
10146 bb_error_msg("%s: bad arguments", argv[0]);
10154 #if ENABLE_HUSH_LOOPS
10155 static int FAST_FUNC builtin_break(char **argv)
10158 if (G.depth_of_loop == 0) {
10159 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10160 /* if we came from builtin_continue(), need to undo "= 1" */
10161 G.flag_break_continue = 0;
10162 return EXIT_SUCCESS; /* bash compat */
10164 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10166 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10167 if (depth == UINT_MAX)
10168 G.flag_break_continue = BC_BREAK;
10169 if (G.depth_of_loop < depth)
10170 G.depth_break_continue = G.depth_of_loop;
10172 return EXIT_SUCCESS;
10175 static int FAST_FUNC builtin_continue(char **argv)
10177 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10178 return builtin_break(argv);
10182 #if ENABLE_HUSH_FUNCTIONS
10183 static int FAST_FUNC builtin_return(char **argv)
10187 if (G_flag_return_in_progress != -1) {
10188 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10189 return EXIT_FAILURE; /* bash compat */
10192 G_flag_return_in_progress = 1;
10195 * out of range: wraps around at 256, does not error out
10196 * non-numeric param:
10197 * f() { false; return qwe; }; f; echo $?
10198 * bash: return: qwe: numeric argument required <== we do this
10199 * 255 <== we also do this
10201 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10206 #if ENABLE_HUSH_MEMLEAK
10207 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10212 # ifdef M_TRIM_THRESHOLD
10213 /* Optional. Reduces probability of false positives */
10216 /* Crude attempt to find where "free memory" starts,
10217 * sans fragmentation. */
10219 l = (unsigned long)p;
10222 if (l < (unsigned long)p) l = (unsigned long)p;
10228 struct mallinfo mi = mallinfo();
10229 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10230 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10234 if (!G.memleak_value)
10235 G.memleak_value = l;
10237 l -= G.memleak_value;
10244 /* Exitcode is "how many kilobytes we leaked since 1st call" */