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 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
88 //config: hush is a small shell (25k). It handles the normal flow control
89 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
90 //config: case/esac. Redirections, here documents, $((arithmetic))
91 //config: and functions are supported.
93 //config: It will compile and work on no-mmu systems.
95 //config: It does not handle select, aliases, tilde expansion,
96 //config: &>file and >&file redirection of stdout+stderr.
98 //config:config HUSH_BASH_COMPAT
99 //config: bool "bash-compatible extensions"
101 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
103 //config: Enable bash-compatible extensions.
105 //config:config HUSH_BRACE_EXPANSION
106 //config: bool "Brace expansion"
108 //config: depends on HUSH_BASH_COMPAT
110 //config: Enable {abc,def} extension.
112 //config:config HUSH_INTERACTIVE
113 //config: bool "Interactive mode"
115 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
117 //config: Enable interactive mode (prompt and command editing).
118 //config: Without this, hush simply reads and executes commands
119 //config: from stdin just like a shell script from a file.
120 //config: No prompt, no PS1/PS2 magic shell variables.
122 //config:config HUSH_SAVEHISTORY
123 //config: bool "Save command history to .hush_history"
125 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
127 //config: Enable history saving in hush.
129 //config:config HUSH_JOB
130 //config: bool "Job control"
132 //config: depends on HUSH_INTERACTIVE
134 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
135 //config: command (not entire shell), fg/bg builtins work. Without this option,
136 //config: "cmd &" still works by simply spawning a process and immediately
137 //config: prompting for next command (or executing next command in a script),
138 //config: but no separate process group is formed.
140 //config:config HUSH_TICK
141 //config: bool "Process substitution"
143 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
145 //config: Enable process substitution `command` and $(command) in hush.
147 //config:config HUSH_IF
148 //config: bool "Support if/then/elif/else/fi"
150 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
152 //config: Enable if/then/elif/else/fi in hush.
154 //config:config HUSH_LOOPS
155 //config: bool "Support for, while and until loops"
157 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
159 //config: Enable for, while and until loops in hush.
161 //config:config HUSH_CASE
162 //config: bool "Support case ... esac statement"
164 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
166 //config: Enable case ... esac statement in hush. +400 bytes.
168 //config:config HUSH_FUNCTIONS
169 //config: bool "Support funcname() { commands; } syntax"
171 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
173 //config: Enable support for shell functions in hush. +800 bytes.
175 //config:config HUSH_LOCAL
176 //config: bool "local builtin"
178 //config: depends on HUSH_FUNCTIONS
180 //config: Enable support for local variables in functions.
182 //config:config HUSH_RANDOM_SUPPORT
183 //config: bool "Pseudorandom generator and $RANDOM variable"
185 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
187 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
188 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
190 //config:config HUSH_MODE_X
191 //config: bool "Support 'hush -x' option and 'set -x' command"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config: This instructs hush to print commands before execution.
196 //config: Adds ~300 bytes.
198 //config:config HUSH_EXPORT
199 //config: bool "export builtin"
201 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
203 //config: Enable export builtin in hush.
205 //config:config HUSH_EXPORT_N
206 //config: bool "Support 'export -n' option"
208 //config: depends on HUSH_EXPORT
210 //config: export -n unexports variables. It is a bash extension.
212 //config:config HUSH_HELP
213 //config: bool "help builtin"
215 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
217 //config: Enable help builtin in hush. Code size + ~1 kbyte.
219 //config:config HUSH_PRINTF
220 //config: bool "printf builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config: Enable printf builtin in hush.
226 //config:config HUSH_KILL
227 //config: bool "kill builtin (for kill %jobspec)"
229 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
231 //config: Enable kill builtin in hush.
233 //config:config HUSH_WAIT
234 //config: bool "wait builtin"
236 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
238 //config: Enable wait builtin in hush.
240 //config:config HUSH_TRAP
241 //config: bool "trap builtin"
243 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
245 //config: Enable trap builtin in hush.
247 //config:config HUSH_ULIMIT
248 //config: bool "ulimit builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config: Enable ulimit builtin in hush.
254 //config:config HUSH_TYPE
255 //config: bool "type builtin"
257 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
259 //config: Enable type builtin in hush.
261 //config:config HUSH_READ
262 //config: bool "read builtin"
264 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
266 //config: Enable read builtin in hush.
268 //config:config HUSH_SET
269 //config: bool "set builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config: Enable set builtin in hush.
275 //config:config HUSH_UNSET
276 //config: bool "unset builtin"
278 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
280 //config: Enable unset builtin in hush.
282 //config:config HUSH_UMASK
283 //config: bool "umask builtin"
285 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
287 //config: Enable umask builtin in hush.
289 //config:config HUSH_MEMLEAK
290 //config: bool "memleak builtin (debugging)"
292 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
294 //config: Enable memleak builtin in hush.
297 //config: bool "msh (deprecated: aliased to hush)"
299 //config: select HUSH
301 //config: msh is deprecated and will be removed, please migrate to hush.
303 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
304 //applet:IF_MSH(APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
305 //applet:IF_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
306 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
308 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
309 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
310 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
311 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
313 /* -i (interactive) and -s (read stdin) are also accepted,
314 * but currently do nothing, therefore aren't shown in help.
315 * NOMMU-specific options are not meant to be used by users,
316 * therefore we don't show them either.
318 //usage:#define hush_trivial_usage
319 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
320 //usage:#define hush_full_usage "\n\n"
321 //usage: "Unix shell interpreter"
323 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
324 || defined(__APPLE__) \
326 # include <malloc.h> /* for malloc_trim */
329 /* #include <dmalloc.h> */
331 # include <fnmatch.h>
333 #include <sys/utsname.h> /* for setting $HOSTNAME */
335 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
337 #include "shell_common.h"
340 #if ENABLE_HUSH_RANDOM_SUPPORT
343 # define CLEAR_RANDOM_T(rnd) ((void)0)
345 #ifndef F_DUPFD_CLOEXEC
346 # define F_DUPFD_CLOEXEC F_DUPFD
349 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
354 #define LEAK_HUNTING 0
355 #define BUILD_AS_NOMMU 0
356 /* Enable/disable sanity checks. Ok to enable in production,
357 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
358 * Keeping 1 for now even in released versions.
361 /* Slightly bigger (+200 bytes), but faster hush.
362 * So far it only enables a trick with counting SIGCHLDs and forks,
363 * which allows us to do fewer waitpid's.
364 * (we can detect a case where neither forks were done nor SIGCHLDs happened
365 * and therefore waitpid will return the same result as last time)
367 #define ENABLE_HUSH_FAST 0
368 /* TODO: implement simplified code for users which do not need ${var%...} ops
369 * So far ${var%...} ops are always enabled:
371 #define ENABLE_HUSH_DOLLAR_OPS 1
376 # undef USE_FOR_NOMMU
379 # define USE_FOR_NOMMU(...) __VA_ARGS__
380 # define USE_FOR_MMU(...)
383 #include "NUM_APPLETS.h"
385 /* STANDALONE does not make sense, and won't compile */
386 # undef CONFIG_FEATURE_SH_STANDALONE
387 # undef ENABLE_FEATURE_SH_STANDALONE
388 # undef IF_FEATURE_SH_STANDALONE
389 # undef IF_NOT_FEATURE_SH_STANDALONE
390 # define ENABLE_FEATURE_SH_STANDALONE 0
391 # define IF_FEATURE_SH_STANDALONE(...)
392 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
395 #if !ENABLE_HUSH_INTERACTIVE
396 # undef ENABLE_FEATURE_EDITING
397 # define ENABLE_FEATURE_EDITING 0
398 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
399 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
400 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
401 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
404 /* Do we support ANY keywords? */
405 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
406 # define HAS_KEYWORDS 1
407 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
408 # define IF_HAS_NO_KEYWORDS(...)
410 # define HAS_KEYWORDS 0
411 # define IF_HAS_KEYWORDS(...)
412 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
415 /* If you comment out one of these below, it will be #defined later
416 * to perform debug printfs to stderr: */
417 #define debug_printf(...) do {} while (0)
418 /* Finer-grained debug switches */
419 #define debug_printf_parse(...) do {} while (0)
420 #define debug_print_tree(a, b) do {} while (0)
421 #define debug_printf_exec(...) do {} while (0)
422 #define debug_printf_env(...) do {} while (0)
423 #define debug_printf_jobs(...) do {} while (0)
424 #define debug_printf_expand(...) do {} while (0)
425 #define debug_printf_varexp(...) do {} while (0)
426 #define debug_printf_glob(...) do {} while (0)
427 #define debug_printf_list(...) do {} while (0)
428 #define debug_printf_subst(...) do {} while (0)
429 #define debug_printf_clean(...) do {} while (0)
431 #define ERR_PTR ((void*)(long)1)
433 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
435 #define _SPECIAL_VARS_STR "_*@$!?#"
436 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
437 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
438 #if ENABLE_HUSH_BASH_COMPAT
439 /* Support / and // replace ops */
440 /* Note that // is stored as \ in "encoded" string representation */
441 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
442 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
443 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
445 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
446 # define VAR_SUBST_OPS "%#:-=+?"
447 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
450 #define SPECIAL_VAR_SYMBOL 3
454 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
456 /* This supports saving pointers malloced in vfork child,
457 * to be freed in the parent.
460 typedef struct nommu_save_t {
462 struct variable *old_vars;
464 char **argv_from_re_execing;
477 #if ENABLE_HUSH_LOOPS
484 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
489 /* three pseudo-keywords support contrived "case" syntax: */
490 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
491 RES_MATCH , /* "word)" */
492 RES_CASE_BODY, /* "this command is inside CASE" */
499 typedef struct o_string {
501 int length; /* position where data is appended */
504 /* At least some part of the string was inside '' or "",
505 * possibly empty one: word"", wo''rd etc. */
506 smallint has_quoted_part;
507 smallint has_empty_slot;
508 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
511 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
513 /* Protect newly added chars against globbing
514 * by prepending \ to *, ?, [, \ */
515 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
518 MAYBE_ASSIGNMENT = 0,
519 DEFINITELY_ASSIGNMENT = 1,
521 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
524 /* Used for initialization: o_string foo = NULL_O_STRING; */
525 #define NULL_O_STRING { NULL }
527 #ifndef debug_printf_parse
528 static const char *const assignment_flag[] = {
530 "DEFINITELY_ASSIGNMENT",
536 typedef struct in_str {
538 #if ENABLE_HUSH_INTERACTIVE
539 smallint promptmode; /* 0: PS1, 1: PS2 */
546 /* The descrip member of this structure is only used to make
547 * debugging output pretty */
548 static const struct {
550 signed char default_fd;
553 { O_RDONLY, 0, "<" },
554 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
555 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
556 { O_CREAT|O_RDWR, 1, "<>" },
557 { O_RDONLY, 0, "<<" },
558 /* Should not be needed. Bogus default_fd helps in debugging */
559 /* { O_RDONLY, 77, "<<" }, */
562 struct redir_struct {
563 struct redir_struct *next;
564 char *rd_filename; /* filename */
565 int rd_fd; /* fd to redirect */
566 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
568 smallint rd_type; /* (enum redir_type) */
569 /* note: for heredocs, rd_filename contains heredoc delimiter,
570 * and subsequently heredoc itself; and rd_dup is a bitmask:
571 * bit 0: do we need to trim leading tabs?
572 * bit 1: is heredoc quoted (<<'delim' syntax) ?
575 typedef enum redir_type {
577 REDIRECT_OVERWRITE = 1,
580 REDIRECT_HEREDOC = 4,
581 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
584 REDIRFD_SYNTAX_ERR = -2,
585 REDIRFD_TO_FILE = -1,
586 /* otherwise, rd_fd is redirected to rd_dup */
588 HEREDOC_SKIPTABS = 1,
594 pid_t pid; /* 0 if exited */
595 int assignment_cnt; /* how many argv[i] are assignments? */
596 smallint cmd_type; /* CMD_xxx */
598 #define CMD_SUBSHELL 1
599 #if ENABLE_HUSH_BASH_COMPAT
600 /* used for "[[ EXPR ]]" */
601 # define CMD_SINGLEWORD_NOGLOB 2
603 #if ENABLE_HUSH_FUNCTIONS
604 # define CMD_FUNCDEF 3
607 smalluint cmd_exitcode;
608 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
611 char *group_as_string;
613 #if ENABLE_HUSH_FUNCTIONS
614 struct function *child_func;
615 /* This field is used to prevent a bug here:
616 * while...do f1() {a;}; f1; f1() {b;}; f1; done
617 * When we execute "f1() {a;}" cmd, we create new function and clear
618 * cmd->group, cmd->group_as_string, cmd->argv[0].
619 * When we execute "f1() {b;}", we notice that f1 exists,
620 * and that its "parent cmd" struct is still "alive",
621 * we put those fields back into cmd->xxx
622 * (struct function has ->parent_cmd ptr to facilitate that).
623 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
624 * Without this trick, loop would execute a;b;b;b;...
625 * instead of correct sequence a;b;a;b;...
626 * When command is freed, it severs the link
627 * (sets ->child_func->parent_cmd to NULL).
630 char **argv; /* command name and arguments */
631 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
632 * and on execution these are substituted with their values.
633 * Substitution can make _several_ words out of one argv[n]!
634 * Example: argv[0]=='.^C*^C.' here: echo .$*.
635 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
637 struct redir_struct *redirects; /* I/O redirections */
639 /* Is there anything in this command at all? */
640 #define IS_NULL_CMD(cmd) \
641 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
645 int num_cmds; /* total number of commands in pipe */
646 int alive_cmds; /* number of commands running (not exited) */
647 int stopped_cmds; /* number of commands alive, but stopped */
649 unsigned jobid; /* job number */
650 pid_t pgrp; /* process group ID for the job */
651 char *cmdtext; /* name of job */
653 struct command *cmds; /* array of commands in pipe */
654 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
655 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
656 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
658 typedef enum pipe_style {
664 /* Is there anything in this pipe at all? */
665 #define IS_NULL_PIPE(pi) \
666 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
668 /* This holds pointers to the various results of parsing */
669 struct parse_context {
670 /* linked list of pipes */
671 struct pipe *list_head;
672 /* last pipe (being constructed right now) */
674 /* last command in pipe (being constructed right now) */
675 struct command *command;
676 /* last redirect in command->redirects list */
677 struct redir_struct *pending_redirect;
683 smallint ctx_inverted; /* "! cmd | cmd" */
685 smallint ctx_dsemicolon; /* ";;" seen */
687 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
689 /* group we are enclosed in:
690 * example: "if pipe1; pipe2; then pipe3; fi"
691 * when we see "if" or "then", we malloc and copy current context,
692 * and make ->stack point to it. then we parse pipeN.
693 * when closing "then" / fi" / whatever is found,
694 * we move list_head into ->stack->command->group,
695 * copy ->stack into current context, and delete ->stack.
696 * (parsing of { list } and ( list ) doesn't use this method)
698 struct parse_context *stack;
702 /* On program start, environ points to initial environment.
703 * putenv adds new pointers into it, unsetenv removes them.
704 * Neither of these (de)allocates the strings.
705 * setenv allocates new strings in malloc space and does putenv,
706 * and thus setenv is unusable (leaky) for shell's purposes */
707 #define setenv(...) setenv_is_leaky_dont_use()
709 struct variable *next;
710 char *varstr; /* points to "name=" portion */
711 #if ENABLE_HUSH_LOCAL
712 unsigned func_nest_level;
714 int max_len; /* if > 0, name is part of initial env; else name is malloced */
715 smallint flg_export; /* putenv should be done on this var */
716 smallint flg_read_only;
724 #if ENABLE_HUSH_FUNCTIONS
726 struct function *next;
728 struct command *parent_cmd;
731 char *body_as_string;
737 /* set -/+o OPT support. (TODO: make it optional)
738 * bash supports the following opts:
749 * interactive-comments on
767 static const char o_opt_strings[] ALIGN1 =
770 #if ENABLE_HUSH_MODE_X
777 #if ENABLE_HUSH_MODE_X
785 struct FILE_list *next;
791 /* "Globals" within this file */
792 /* Sorted roughly by size (smaller offsets == smaller code) */
794 /* interactive_fd != 0 means we are an interactive shell.
795 * If we are, then saved_tty_pgrp can also be != 0, meaning
796 * that controlling tty is available. With saved_tty_pgrp == 0,
797 * job control still works, but terminal signals
798 * (^C, ^Z, ^Y, ^\) won't work at all, and background
799 * process groups can only be created with "cmd &".
800 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
801 * to give tty to the foreground process group,
802 * and will take it back when the group is stopped (^Z)
805 #if ENABLE_HUSH_INTERACTIVE
806 /* 'interactive_fd' is a fd# open to ctty, if we have one
807 * _AND_ if we decided to act interactively */
811 # define G_interactive_fd (G.interactive_fd)
813 # define G_interactive_fd 0
815 #if ENABLE_FEATURE_EDITING
816 line_input_t *line_input_state;
821 #if ENABLE_HUSH_RANDOM_SUPPORT
827 pid_t saved_tty_pgrp;
828 struct pipe *job_list;
829 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
831 # define G_saved_tty_pgrp 0
833 char o_opt[NUM_OPT_O];
834 #if ENABLE_HUSH_MODE_X
835 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
839 smallint flag_SIGINT;
840 #if ENABLE_HUSH_LOOPS
841 smallint flag_break_continue;
843 #if ENABLE_HUSH_FUNCTIONS
844 /* 0: outside of a function (or sourced file)
845 * -1: inside of a function, ok to use return builtin
846 * 1: return is invoked, skip all till end of func
848 smallint flag_return_in_progress;
849 # define G_flag_return_in_progress (G.flag_return_in_progress)
851 # define G_flag_return_in_progress 0
853 smallint exiting; /* used to prevent EXIT trap recursion */
854 /* These four support $?, $#, and $1 */
855 smalluint last_exitcode;
857 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
858 smalluint global_args_malloced;
859 # define G_global_args_malloced (G.global_args_malloced)
861 # define G_global_args_malloced 0
863 /* how many non-NULL argv's we have. NB: $# + 1 */
867 char *argv0_for_re_execing;
869 #if ENABLE_HUSH_LOOPS
870 unsigned depth_break_continue;
871 unsigned depth_of_loop;
875 struct variable *top_var;
876 char **expanded_assignments;
877 #if ENABLE_HUSH_FUNCTIONS
878 struct function *top_func;
879 # if ENABLE_HUSH_LOCAL
880 struct variable **shadowed_vars_pp;
881 unsigned func_nest_level;
884 /* Signal and trap handling */
886 unsigned count_SIGCHLD;
887 unsigned handled_SIGCHLD;
888 smallint we_have_children;
890 struct FILE_list *FILE_list;
891 /* Which signals have non-DFL handler (even with no traps set)?
892 * Set at the start to:
893 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
894 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
895 * The rest is cleared right before execv syscalls.
896 * Other than these two times, never modified.
898 unsigned special_sig_mask;
900 unsigned fatal_sig_mask;
901 # define G_fatal_sig_mask (G.fatal_sig_mask)
903 # define G_fatal_sig_mask 0
906 char **traps; /* char *traps[NSIG] */
907 # define G_traps G.traps
909 # define G_traps ((char**)NULL)
911 sigset_t pending_set;
912 #if ENABLE_HUSH_MEMLEAK
913 unsigned long memleak_value;
919 #if ENABLE_FEATURE_EDITING
920 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
923 #define G (*ptr_to_globals)
924 /* Not #defining name to G.name - this quickly gets unwieldy
925 * (too many defines). Also, I actually prefer to see when a variable
926 * is global, thus "G." prefix is a useful hint */
927 #define INIT_G() do { \
928 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
929 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
930 sigfillset(&G.sa.sa_mask); \
931 G.sa.sa_flags = SA_RESTART; \
935 /* Function prototypes for builtins */
936 static int builtin_cd(char **argv) FAST_FUNC;
937 static int builtin_echo(char **argv) FAST_FUNC;
938 static int builtin_eval(char **argv) FAST_FUNC;
939 static int builtin_exec(char **argv) FAST_FUNC;
940 static int builtin_exit(char **argv) FAST_FUNC;
941 #if ENABLE_HUSH_EXPORT
942 static int builtin_export(char **argv) FAST_FUNC;
945 static int builtin_fg_bg(char **argv) FAST_FUNC;
946 static int builtin_jobs(char **argv) FAST_FUNC;
949 static int builtin_help(char **argv) FAST_FUNC;
951 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
952 static int builtin_history(char **argv) FAST_FUNC;
954 #if ENABLE_HUSH_LOCAL
955 static int builtin_local(char **argv) FAST_FUNC;
957 #if ENABLE_HUSH_MEMLEAK
958 static int builtin_memleak(char **argv) FAST_FUNC;
960 #if ENABLE_HUSH_PRINTF
961 static int builtin_printf(char **argv) FAST_FUNC;
963 static int builtin_pwd(char **argv) FAST_FUNC;
965 static int builtin_read(char **argv) FAST_FUNC;
968 static int builtin_set(char **argv) FAST_FUNC;
970 static int builtin_shift(char **argv) FAST_FUNC;
971 static int builtin_source(char **argv) FAST_FUNC;
972 static int builtin_test(char **argv) FAST_FUNC;
974 static int builtin_trap(char **argv) FAST_FUNC;
977 static int builtin_type(char **argv) FAST_FUNC;
979 static int builtin_true(char **argv) FAST_FUNC;
980 #if ENABLE_HUSH_UMASK
981 static int builtin_umask(char **argv) FAST_FUNC;
983 #if ENABLE_HUSH_UNSET
984 static int builtin_unset(char **argv) FAST_FUNC;
987 static int builtin_kill(char **argv) FAST_FUNC;
990 static int builtin_wait(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_LOOPS
993 static int builtin_break(char **argv) FAST_FUNC;
994 static int builtin_continue(char **argv) FAST_FUNC;
996 #if ENABLE_HUSH_FUNCTIONS
997 static int builtin_return(char **argv) FAST_FUNC;
1000 /* Table of built-in functions. They can be forked or not, depending on
1001 * context: within pipes, they fork. As simple commands, they do not.
1002 * When used in non-forking context, they can change global variables
1003 * in the parent shell process. If forked, of course they cannot.
1004 * For example, 'unset foo | whatever' will parse and run, but foo will
1005 * still be set at the end. */
1006 struct built_in_command {
1008 int (*b_function)(char **argv) FAST_FUNC;
1009 #if ENABLE_HUSH_HELP
1010 const char *b_descr;
1011 # define BLTIN(cmd, func, help) { cmd, func, help }
1013 # define BLTIN(cmd, func, help) { cmd, func }
1017 static const struct built_in_command bltins1[] = {
1018 BLTIN("." , builtin_source , "Run commands in a file"),
1019 BLTIN(":" , builtin_true , NULL),
1021 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
1023 #if ENABLE_HUSH_LOOPS
1024 BLTIN("break" , builtin_break , "Exit from a loop"),
1026 BLTIN("cd" , builtin_cd , "Change directory"),
1027 #if ENABLE_HUSH_LOOPS
1028 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1030 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1031 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1032 BLTIN("exit" , builtin_exit , "Exit"),
1033 #if ENABLE_HUSH_EXPORT
1034 BLTIN("export" , builtin_export , "Set environment variables"),
1037 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
1039 #if ENABLE_HUSH_HELP
1040 BLTIN("help" , builtin_help , NULL),
1042 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1043 BLTIN("history" , builtin_history , "Show command history"),
1046 BLTIN("jobs" , builtin_jobs , "List jobs"),
1048 #if ENABLE_HUSH_KILL
1049 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1051 #if ENABLE_HUSH_LOCAL
1052 BLTIN("local" , builtin_local , "Set local variables"),
1054 #if ENABLE_HUSH_MEMLEAK
1055 BLTIN("memleak" , builtin_memleak , NULL),
1057 #if ENABLE_HUSH_READ
1058 BLTIN("read" , builtin_read , "Input into variable"),
1060 #if ENABLE_HUSH_FUNCTIONS
1061 BLTIN("return" , builtin_return , "Return from a function"),
1064 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
1066 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1067 #if ENABLE_HUSH_BASH_COMPAT
1068 BLTIN("source" , builtin_source , "Run commands in a file"),
1070 #if ENABLE_HUSH_TRAP
1071 BLTIN("trap" , builtin_trap , "Trap signals"),
1073 BLTIN("true" , builtin_true , NULL),
1074 #if ENABLE_HUSH_TYPE
1075 BLTIN("type" , builtin_type , "Show command type"),
1077 #if ENABLE_HUSH_ULIMIT
1078 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1080 #if ENABLE_HUSH_UMASK
1081 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1083 #if ENABLE_HUSH_UNSET
1084 BLTIN("unset" , builtin_unset , "Unset variables"),
1086 #if ENABLE_HUSH_WAIT
1087 BLTIN("wait" , builtin_wait , "Wait for process"),
1090 /* For now, echo and test are unconditionally enabled.
1091 * Maybe make it configurable? */
1092 static const struct built_in_command bltins2[] = {
1093 BLTIN("[" , builtin_test , NULL),
1094 BLTIN("echo" , builtin_echo , NULL),
1095 #if ENABLE_HUSH_PRINTF
1096 BLTIN("printf" , builtin_printf , NULL),
1098 BLTIN("pwd" , builtin_pwd , NULL),
1099 BLTIN("test" , builtin_test , NULL),
1106 /* prevent disasters with G.debug_indent < 0 */
1107 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1108 # define debug_enter() (G.debug_indent++)
1109 # define debug_leave() (G.debug_indent--)
1111 # define indent() ((void)0)
1112 # define debug_enter() ((void)0)
1113 # define debug_leave() ((void)0)
1116 #ifndef debug_printf
1117 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1120 #ifndef debug_printf_parse
1121 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1124 #ifndef debug_printf_exec
1125 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1128 #ifndef debug_printf_env
1129 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1132 #ifndef debug_printf_jobs
1133 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1134 # define DEBUG_JOBS 1
1136 # define DEBUG_JOBS 0
1139 #ifndef debug_printf_expand
1140 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1141 # define DEBUG_EXPAND 1
1143 # define DEBUG_EXPAND 0
1146 #ifndef debug_printf_varexp
1147 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1150 #ifndef debug_printf_glob
1151 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1152 # define DEBUG_GLOB 1
1154 # define DEBUG_GLOB 0
1157 #ifndef debug_printf_list
1158 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1161 #ifndef debug_printf_subst
1162 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1165 #ifndef debug_printf_clean
1166 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 # define DEBUG_CLEAN 1
1169 # define DEBUG_CLEAN 0
1173 static void debug_print_strings(const char *prefix, char **vv)
1176 fdprintf(2, "%s:\n", prefix);
1178 fdprintf(2, " '%s'\n", *vv++);
1181 # define debug_print_strings(prefix, vv) ((void)0)
1185 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1188 static void *xxmalloc(int lineno, size_t size)
1190 void *ptr = xmalloc((size + 0xff) & ~0xff);
1191 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1194 static void *xxrealloc(int lineno, void *ptr, size_t size)
1196 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1197 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1200 static char *xxstrdup(int lineno, const char *str)
1202 char *ptr = xstrdup(str);
1203 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1206 static void xxfree(void *ptr)
1208 fdprintf(2, "free %p\n", ptr);
1211 # define xmalloc(s) xxmalloc(__LINE__, s)
1212 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1213 # define xstrdup(s) xxstrdup(__LINE__, s)
1214 # define free(p) xxfree(p)
1218 /* Syntax and runtime errors. They always abort scripts.
1219 * In interactive use they usually discard unparsed and/or unexecuted commands
1220 * and return to the prompt.
1221 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1224 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1225 # define syntax_error(lineno, msg) syntax_error(msg)
1226 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1227 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1228 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1229 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1232 static void die_if_script(unsigned lineno, const char *fmt, ...)
1237 bb_error_msg("hush.c:%u", lineno);
1240 bb_verror_msg(fmt, p, NULL);
1242 if (!G_interactive_fd)
1246 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1249 bb_error_msg("syntax error: %s", msg);
1251 bb_error_msg("syntax error");
1254 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1256 bb_error_msg("syntax error at '%s'", msg);
1259 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1261 bb_error_msg("syntax error: unterminated %s", s);
1264 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1266 char msg[2] = { ch, '\0' };
1267 syntax_error_unterm_str(lineno, msg);
1270 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1276 bb_error_msg("hush.c:%u", lineno);
1278 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1282 # undef die_if_script
1283 # undef syntax_error
1284 # undef syntax_error_at
1285 # undef syntax_error_unterm_ch
1286 # undef syntax_error_unterm_str
1287 # undef syntax_error_unexpected_ch
1289 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1290 # define syntax_error(msg) syntax_error(__LINE__, msg)
1291 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1292 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1293 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1294 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1298 #if ENABLE_HUSH_INTERACTIVE
1299 static void cmdedit_update_prompt(void);
1301 # define cmdedit_update_prompt() ((void)0)
1305 /* Utility functions
1307 /* Replace each \x with x in place, return ptr past NUL. */
1308 static char *unbackslash(char *src)
1310 char *dst = src = strchrnul(src, '\\');
1314 if ((*dst++ = *src++) == '\0')
1320 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1341 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1342 v[count1 + count2] = NULL;
1345 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1349 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1351 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1352 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1355 #define add_strings_to_strings(strings, add, need_to_dup) \
1356 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1359 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1360 static char **add_string_to_strings(char **strings, char *add)
1365 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1368 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1370 char **ptr = add_string_to_strings(strings, add);
1371 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1374 #define add_string_to_strings(strings, add) \
1375 xx_add_string_to_strings(__LINE__, strings, add)
1378 static void free_strings(char **strings)
1393 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1395 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1396 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1398 /* fd was not open? */
1408 /* Manipulating the list of open FILEs */
1409 static FILE *remember_FILE(FILE *fp)
1412 struct FILE_list *n = xmalloc(sizeof(*n));
1413 n->next = G.FILE_list;
1417 close_on_exec_on(n->fd);
1421 static void fclose_and_forget(FILE *fp)
1423 struct FILE_list **pp = &G.FILE_list;
1425 struct FILE_list *cur = *pp;
1426 if (cur->fp == fp) {
1435 static int save_FILEs_on_redirect(int fd)
1437 struct FILE_list *fl = G.FILE_list;
1440 /* We use it only on script files, they are all CLOEXEC */
1441 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1448 static void restore_redirected_FILEs(void)
1450 struct FILE_list *fl = G.FILE_list;
1452 int should_be = fileno(fl->fp);
1453 if (fl->fd != should_be) {
1454 xmove_fd(fl->fd, should_be);
1460 #if ENABLE_FEATURE_SH_STANDALONE
1461 static void close_all_FILE_list(void)
1463 struct FILE_list *fl = G.FILE_list;
1465 /* fclose would also free FILE object.
1466 * It is disastrous if we share memory with a vforked parent.
1467 * I'm not sure we never come here after vfork.
1468 * Therefore just close fd, nothing more.
1470 /*fclose(fl->fp); - unsafe */
1478 /* Helpers for setting new $n and restoring them back
1480 typedef struct save_arg_t {
1484 IF_HUSH_SET(smallint sv_g_malloced;)
1487 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1491 sv->sv_argv0 = argv[0];
1492 sv->sv_g_argv = G.global_argv;
1493 sv->sv_g_argc = G.global_argc;
1494 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1496 argv[0] = G.global_argv[0]; /* retain $0 */
1497 G.global_argv = argv;
1498 IF_HUSH_SET(G.global_args_malloced = 0;)
1506 static void restore_G_args(save_arg_t *sv, char **argv)
1509 if (G.global_args_malloced) {
1510 /* someone ran "set -- arg1 arg2 ...", undo */
1511 char **pp = G.global_argv;
1512 while (*++pp) /* note: does not free $0 */
1514 free(G.global_argv);
1517 argv[0] = sv->sv_argv0;
1518 G.global_argv = sv->sv_g_argv;
1519 G.global_argc = sv->sv_g_argc;
1520 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1524 /* Basic theory of signal handling in shell
1525 * ========================================
1526 * This does not describe what hush does, rather, it is current understanding
1527 * what it _should_ do. If it doesn't, it's a bug.
1528 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1530 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1531 * is finished or backgrounded. It is the same in interactive and
1532 * non-interactive shells, and is the same regardless of whether
1533 * a user trap handler is installed or a shell special one is in effect.
1534 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1535 * backgrounds (i.e. stops) or kills all members of currently running
1538 * Wait builtin is interruptible by signals for which user trap is set
1539 * or by SIGINT in interactive shell.
1541 * Trap handlers will execute even within trap handlers. (right?)
1543 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1544 * except for handlers set to '' (empty string).
1546 * If job control is off, backgrounded commands ("cmd &")
1547 * have SIGINT, SIGQUIT set to SIG_IGN.
1549 * Commands which are run in command substitution ("`cmd`")
1550 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1552 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1553 * by the shell from its parent.
1555 * Signals which differ from SIG_DFL action
1556 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1559 * SIGTERM (interactive): ignore
1560 * SIGHUP (interactive):
1561 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1562 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1563 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1564 * that all pipe members are stopped. Try this in bash:
1565 * while :; do :; done - ^Z does not background it
1566 * (while :; do :; done) - ^Z backgrounds it
1567 * SIGINT (interactive): wait for last pipe, ignore the rest
1568 * of the command line, show prompt. NB: ^C does not send SIGINT
1569 * to interactive shell while shell is waiting for a pipe,
1570 * since shell is bg'ed (is not in foreground process group).
1571 * Example 1: this waits 5 sec, but does not execute ls:
1572 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1573 * Example 2: this does not wait and does not execute ls:
1574 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1575 * Example 3: this does not wait 5 sec, but executes ls:
1576 * "sleep 5; ls -l" + press ^C
1577 * Example 4: this does not wait and does not execute ls:
1578 * "sleep 5 & wait; ls -l" + press ^C
1580 * (What happens to signals which are IGN on shell start?)
1581 * (What happens with signal mask on shell start?)
1583 * Old implementation
1584 * ==================
1585 * We use in-kernel pending signal mask to determine which signals were sent.
1586 * We block all signals which we don't want to take action immediately,
1587 * i.e. we block all signals which need to have special handling as described
1588 * above, and all signals which have traps set.
1589 * After each pipe execution, we extract any pending signals via sigtimedwait()
1592 * unsigned special_sig_mask: a mask of such "special" signals
1593 * sigset_t blocked_set: current blocked signal set
1596 * clear bit in blocked_set unless it is also in special_sig_mask
1597 * "trap 'cmd' SIGxxx":
1598 * set bit in blocked_set (even if 'cmd' is '')
1599 * after [v]fork, if we plan to be a shell:
1600 * unblock signals with special interactive handling
1601 * (child shell is not interactive),
1602 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1603 * after [v]fork, if we plan to exec:
1604 * POSIX says fork clears pending signal mask in child - no need to clear it.
1605 * Restore blocked signal set to one inherited by shell just prior to exec.
1607 * Note: as a result, we do not use signal handlers much. The only uses
1608 * are to count SIGCHLDs
1609 * and to restore tty pgrp on signal-induced exit.
1612 * Standard says "When a subshell is entered, traps that are not being ignored
1613 * are set to the default actions". bash interprets it so that traps which
1614 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1616 * Problem: the above approach makes it unwieldy to catch signals while
1617 * we are in read builtin, or while we read commands from stdin:
1618 * masked signals are not visible!
1620 * New implementation
1621 * ==================
1622 * We record each signal we are interested in by installing signal handler
1623 * for them - a bit like emulating kernel pending signal mask in userspace.
1624 * We are interested in: signals which need to have special handling
1625 * as described above, and all signals which have traps set.
1626 * Signals are recorded in pending_set.
1627 * After each pipe execution, we extract any pending signals
1630 * unsigned special_sig_mask: a mask of shell-special signals.
1631 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1632 * char *traps[sig] if trap for sig is set (even if it's '').
1633 * sigset_t pending_set: set of sigs we received.
1636 * if sig is in special_sig_mask, set handler back to:
1637 * record_pending_signo, or to IGN if it's a tty stop signal
1638 * if sig is in fatal_sig_mask, set handler back to sigexit.
1639 * else: set handler back to SIG_DFL
1640 * "trap 'cmd' SIGxxx":
1641 * set handler to record_pending_signo.
1643 * set handler to SIG_IGN.
1644 * after [v]fork, if we plan to be a shell:
1645 * set signals with special interactive handling to SIG_DFL
1646 * (because child shell is not interactive),
1647 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1648 * after [v]fork, if we plan to exec:
1649 * POSIX says fork clears pending signal mask in child - no need to clear it.
1651 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1652 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1655 * Standard says "When a subshell is entered, traps that are not being ignored
1656 * are set to the default actions". bash interprets it so that traps which
1657 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1660 SPECIAL_INTERACTIVE_SIGS = 0
1665 SPECIAL_JOBSTOP_SIGS = 0
1674 static void record_pending_signo(int sig)
1676 sigaddset(&G.pending_set, sig);
1677 #if ENABLE_HUSH_FAST
1678 if (sig == SIGCHLD) {
1680 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1685 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1687 struct sigaction old_sa;
1689 /* We could use signal() to install handlers... almost:
1690 * except that we need to mask ALL signals while handlers run.
1691 * I saw signal nesting in strace, race window isn't small.
1692 * SA_RESTART is also needed, but in Linux, signal()
1693 * sets SA_RESTART too.
1695 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1696 /* sigfillset(&G.sa.sa_mask); - already done */
1697 /* G.sa.sa_flags = SA_RESTART; - already done */
1698 G.sa.sa_handler = handler;
1699 sigaction(sig, &G.sa, &old_sa);
1700 return old_sa.sa_handler;
1703 static void hush_exit(int exitcode) NORETURN;
1705 static void restore_ttypgrp_and__exit(void) NORETURN;
1706 static void restore_ttypgrp_and__exit(void)
1708 /* xfunc has failed! die die die */
1709 /* no EXIT traps, this is an escape hatch! */
1711 hush_exit(xfunc_error_retval);
1716 /* Needed only on some libc:
1717 * It was observed that on exit(), fgetc'ed buffered data
1718 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1719 * With the net effect that even after fork(), not vfork(),
1720 * exit() in NOEXECed applet in "sh SCRIPT":
1721 * noexec_applet_here
1722 * echo END_OF_SCRIPT
1723 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1724 * This makes "echo END_OF_SCRIPT" executed twice.
1725 * Similar problems can be seen with die_if_script() -> xfunc_die()
1726 * and in `cmd` handling.
1727 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1729 static void fflush_and__exit(void) NORETURN;
1730 static void fflush_and__exit(void)
1733 _exit(xfunc_error_retval);
1736 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1737 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1738 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1739 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1741 /* Restores tty foreground process group, and exits.
1742 * May be called as signal handler for fatal signal
1743 * (will resend signal to itself, producing correct exit state)
1744 * or called directly with -EXITCODE.
1745 * We also call it if xfunc is exiting.
1747 static void sigexit(int sig) NORETURN;
1748 static void sigexit(int sig)
1750 /* Careful: we can end up here after [v]fork. Do not restore
1751 * tty pgrp then, only top-level shell process does that */
1752 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1753 /* Disable all signals: job control, SIGPIPE, etc.
1754 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1756 sigprocmask_allsigs(SIG_BLOCK);
1757 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1760 /* Not a signal, just exit */
1764 kill_myself_with_sig(sig); /* does not return */
1768 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1769 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1773 static sighandler_t pick_sighandler(unsigned sig)
1775 sighandler_t handler = SIG_DFL;
1776 if (sig < sizeof(unsigned)*8) {
1777 unsigned sigmask = (1 << sig);
1781 if (G_fatal_sig_mask & sigmask)
1785 /* sig has special handling? */
1786 if (G.special_sig_mask & sigmask) {
1787 handler = record_pending_signo;
1788 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1789 * in order to ignore them: they will be raised
1790 * in an endless loop when we try to do some
1791 * terminal ioctls! We do have to _ignore_ these.
1793 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1800 /* Restores tty foreground process group, and exits. */
1801 static void hush_exit(int exitcode)
1803 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1804 save_history(G.line_input_state);
1808 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1810 /* argv[0] is unused */
1811 argv[1] = G_traps[0];
1813 G.exiting = 1; /* prevent EXIT trap recursion */
1814 /* Note: G_traps[0] is not cleared!
1815 * "trap" will still show it, if executed
1820 #if ENABLE_FEATURE_CLEAN_UP
1822 struct variable *cur_var;
1823 if (G.cwd != bb_msg_unknown)
1825 cur_var = G.top_var;
1827 struct variable *tmp = cur_var;
1828 if (!cur_var->max_len)
1829 free(cur_var->varstr);
1830 cur_var = cur_var->next;
1838 sigexit(- (exitcode & 0xff));
1845 //TODO: return a mask of ALL handled sigs?
1846 static int check_and_run_traps(void)
1853 if (sigisemptyset(&G.pending_set))
1858 if (sigismember(&G.pending_set, sig)) {
1859 sigdelset(&G.pending_set, sig);
1862 } while (sig < NSIG);
1865 if (G_traps && G_traps[sig]) {
1866 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1867 if (G_traps[sig][0]) {
1868 /* We have user-defined handler */
1869 smalluint save_rcode;
1871 /* argv[0] is unused */
1872 argv[1] = G_traps[sig];
1874 save_rcode = G.last_exitcode;
1876 //FIXME: shouldn't it be set to 128 + sig instead?
1877 G.last_exitcode = save_rcode;
1879 } /* else: "" trap, ignoring signal */
1882 /* not a trap: special action */
1885 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1892 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1893 /* bash is observed to signal whole process groups,
1894 * not individual processes */
1895 for (job = G.job_list; job; job = job->next) {
1898 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1899 if (kill(- job->pgrp, SIGHUP) == 0)
1900 kill(- job->pgrp, SIGCONT);
1905 #if ENABLE_HUSH_FAST
1907 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1909 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1911 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1912 * This simplifies wait builtin a bit.
1916 default: /* ignored: */
1917 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1918 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1920 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1921 * Example: wait is not interrupted by TERM
1922 * in interactive shell, because TERM is ignored.
1931 static const char *get_cwd(int force)
1933 if (force || G.cwd == NULL) {
1934 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1935 * we must not try to free(bb_msg_unknown) */
1936 if (G.cwd == bb_msg_unknown)
1938 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1940 G.cwd = bb_msg_unknown;
1947 * Shell and environment variable support
1949 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1951 struct variable **pp;
1952 struct variable *cur;
1955 while ((cur = *pp) != NULL) {
1956 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1963 static const char* FAST_FUNC get_local_var_value(const char *name)
1965 struct variable **vpp;
1966 unsigned len = strlen(name);
1968 if (G.expanded_assignments) {
1969 char **cpp = G.expanded_assignments;
1972 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1973 return cp + len + 1;
1978 vpp = get_ptr_to_local_var(name, len);
1980 return (*vpp)->varstr + len + 1;
1982 if (strcmp(name, "PPID") == 0)
1983 return utoa(G.root_ppid);
1984 // bash compat: UID? EUID?
1985 #if ENABLE_HUSH_RANDOM_SUPPORT
1986 if (strcmp(name, "RANDOM") == 0)
1987 return utoa(next_random(&G.random_gen));
1992 /* str holds "NAME=VAL" and is expected to be malloced.
1993 * We take ownership of it.
1995 * 0: do not change export flag
1996 * (if creating new variable, flag will be 0)
1997 * 1: set export flag and putenv the variable
1998 * -1: clear export flag and unsetenv the variable
1999 * flg_read_only is set only when we handle -R var=val
2001 #if !BB_MMU && ENABLE_HUSH_LOCAL
2002 /* all params are used */
2003 #elif BB_MMU && ENABLE_HUSH_LOCAL
2004 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2005 set_local_var(str, flg_export, local_lvl)
2006 #elif BB_MMU && !ENABLE_HUSH_LOCAL
2007 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2008 set_local_var(str, flg_export)
2009 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2010 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2011 set_local_var(str, flg_export, flg_read_only)
2013 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2015 struct variable **var_pp;
2016 struct variable *cur;
2017 char *free_me = NULL;
2021 eq_sign = strchr(str, '=');
2022 if (!eq_sign) { /* not expected to ever happen? */
2027 name_len = eq_sign - str + 1; /* including '=' */
2028 var_pp = &G.top_var;
2029 while ((cur = *var_pp) != NULL) {
2030 if (strncmp(cur->varstr, str, name_len) != 0) {
2031 var_pp = &cur->next;
2035 /* We found an existing var with this name */
2036 if (cur->flg_read_only) {
2040 bb_error_msg("%s: readonly variable", str);
2044 if (flg_export == -1) { // "&& cur->flg_export" ?
2045 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2050 #if ENABLE_HUSH_LOCAL
2051 if (cur->func_nest_level < local_lvl) {
2052 /* New variable is declared as local,
2053 * and existing one is global, or local
2054 * from enclosing function.
2055 * Remove and save old one: */
2056 *var_pp = cur->next;
2057 cur->next = *G.shadowed_vars_pp;
2058 *G.shadowed_vars_pp = cur;
2059 /* bash 3.2.33(1) and exported vars:
2061 * # f() { local z=a; env | grep ^z; }
2067 if (cur->flg_export)
2072 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2077 if (cur->max_len != 0) {
2078 if (cur->max_len >= strlen(str)) {
2079 /* This one is from startup env, reuse space */
2080 strcpy(cur->varstr, str);
2085 goto set_str_and_exp;
2087 /* max_len == 0 signifies "malloced" var, which we can
2088 * (and have to) free. But we can't free(cur->varstr) here:
2089 * if cur->flg_export is 1, it is in the environment.
2090 * We should either unsetenv+free, or wait until putenv,
2091 * then putenv(new)+free(old).
2093 free_me = cur->varstr;
2094 goto set_str_and_exp;
2097 /* Not found - create new variable struct */
2098 cur = xzalloc(sizeof(*cur));
2099 #if ENABLE_HUSH_LOCAL
2100 cur->func_nest_level = local_lvl;
2102 cur->next = *var_pp;
2108 cur->flg_read_only = flg_read_only;
2111 if (flg_export == 1)
2112 cur->flg_export = 1;
2113 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2114 cmdedit_update_prompt();
2115 if (cur->flg_export) {
2116 if (flg_export == -1) {
2117 cur->flg_export = 0;
2118 /* unsetenv was already done */
2121 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2122 i = putenv(cur->varstr);
2123 /* only now we can free old exported malloced string */
2132 /* Used at startup and after each cd */
2133 static void set_pwd_var(int exp)
2135 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2136 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2139 static int unset_local_var_len(const char *name, int name_len)
2141 struct variable *cur;
2142 struct variable **var_pp;
2145 return EXIT_SUCCESS;
2146 var_pp = &G.top_var;
2147 while ((cur = *var_pp) != NULL) {
2148 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2149 if (cur->flg_read_only) {
2150 bb_error_msg("%s: readonly variable", name);
2151 return EXIT_FAILURE;
2153 *var_pp = cur->next;
2154 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2155 bb_unsetenv(cur->varstr);
2156 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2157 cmdedit_update_prompt();
2161 return EXIT_SUCCESS;
2163 var_pp = &cur->next;
2165 return EXIT_SUCCESS;
2168 #if ENABLE_HUSH_UNSET
2169 static int unset_local_var(const char *name)
2171 return unset_local_var_len(name, strlen(name));
2175 static void unset_vars(char **strings)
2183 const char *eq = strchrnul(*v, '=');
2184 unset_local_var_len(*v, (int)(eq - *v));
2190 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_BASH_COMPAT || ENABLE_HUSH_READ
2191 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2193 char *var = xasprintf("%s=%s", name, val);
2194 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2200 * Helpers for "var1=val1 var2=val2 cmd" feature
2202 static void add_vars(struct variable *var)
2204 struct variable *next;
2208 var->next = G.top_var;
2210 if (var->flg_export) {
2211 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2212 putenv(var->varstr);
2214 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2220 static struct variable *set_vars_and_save_old(char **strings)
2223 struct variable *old = NULL;
2229 struct variable *var_p;
2230 struct variable **var_pp;
2233 eq = strchr(*s, '=');
2235 var_pp = get_ptr_to_local_var(*s, eq - *s);
2237 /* Remove variable from global linked list */
2239 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2240 *var_pp = var_p->next;
2241 /* Add it to returned list */
2245 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2256 static void reinit_unicode_for_hush(void)
2258 /* Unicode support should be activated even if LANG is set
2259 * _during_ shell execution, not only if it was set when
2260 * shell was started. Therefore, re-check LANG every time:
2262 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2263 || ENABLE_UNICODE_USING_LOCALE
2265 const char *s = get_local_var_value("LC_ALL");
2266 if (!s) s = get_local_var_value("LC_CTYPE");
2267 if (!s) s = get_local_var_value("LANG");
2273 * in_str support (strings, and "strings" read from files).
2276 #if ENABLE_HUSH_INTERACTIVE
2277 /* To test correct lineedit/interactive behavior, type from command line:
2283 * It excercises a lot of corner cases.
2285 static void cmdedit_update_prompt(void)
2287 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2288 G.PS1 = get_local_var_value("PS1");
2291 G.PS2 = get_local_var_value("PS2");
2298 static const char *setup_prompt_string(int promptmode)
2300 const char *prompt_str;
2301 debug_printf("setup_prompt_string %d ", promptmode);
2302 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2303 /* Set up the prompt */
2304 if (promptmode == 0) { /* PS1 */
2306 /* bash uses $PWD value, even if it is set by user.
2307 * It uses current dir only if PWD is unset.
2308 * We always use current dir. */
2309 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2314 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2315 debug_printf("prompt_str '%s'\n", prompt_str);
2318 static int get_user_input(struct in_str *i)
2321 const char *prompt_str;
2323 prompt_str = setup_prompt_string(i->promptmode);
2324 # if ENABLE_FEATURE_EDITING
2326 reinit_unicode_for_hush();
2327 if (G.flag_SIGINT) {
2328 /* There was ^C'ed, make it look prettier: */
2332 /* buglet: SIGINT will not make new prompt to appear _at once_,
2333 * only after <Enter>. (^C works immediately) */
2334 r = read_line_input(G.line_input_state, prompt_str,
2335 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2338 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2340 write(STDOUT_FILENO, "^C", 2);
2343 check_and_run_traps();
2344 if (r != 0 && !G.flag_SIGINT)
2346 /* ^C or SIGINT: repeat */
2347 G.last_exitcode = 128 + SIGINT;
2350 /* EOF/error detected */
2352 i->peek_buf[0] = r = EOF;
2355 i->p = G.user_input_buf;
2356 return (unsigned char)*i->p++;
2360 if (i->last_char == '\0' || i->last_char == '\n') {
2361 /* Why check_and_run_traps here? Try this interactively:
2362 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2363 * $ <[enter], repeatedly...>
2364 * Without check_and_run_traps, handler never runs.
2366 check_and_run_traps();
2367 fputs(prompt_str, stdout);
2370 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2372 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2373 * no ^C masking happens during fgetc, no special code for ^C:
2374 * it generates SIGINT as usual.
2376 check_and_run_traps();
2378 G.last_exitcode = 128 + SIGINT;
2385 /* This is the magic location that prints prompts
2386 * and gets data back from the user */
2387 static int fgetc_interactive(struct in_str *i)
2390 /* If it's interactive stdin, get new line. */
2391 if (G_interactive_fd && i->file == stdin) {
2392 /* Returns first char (or EOF), the rest is in i->p[] */
2393 ch = get_user_input(i);
2394 i->promptmode = 1; /* PS2 */
2396 /* Not stdin: script file, sourced file, etc */
2397 do ch = fgetc(i->file); while (ch == '\0');
2402 static inline int fgetc_interactive(struct in_str *i)
2405 do ch = fgetc(i->file); while (ch == '\0');
2408 #endif /* INTERACTIVE */
2410 static int i_getch(struct in_str *i)
2415 /* string-based in_str */
2416 ch = (unsigned char)*i->p;
2425 /* FILE-based in_str */
2427 #if ENABLE_FEATURE_EDITING
2428 /* This can be stdin, check line editing char[] buffer */
2429 if (i->p && *i->p != '\0') {
2430 ch = (unsigned char)*i->p++;
2434 /* peek_buf[] is an int array, not char. Can contain EOF. */
2435 ch = i->peek_buf[0];
2437 int ch2 = i->peek_buf[1];
2438 i->peek_buf[0] = ch2;
2439 if (ch2 == 0) /* very likely, avoid redundant write */
2445 ch = fgetc_interactive(i);
2447 debug_printf("file_get: got '%c' %d\n", ch, ch);
2452 static int i_peek(struct in_str *i)
2457 /* string-based in_str */
2458 /* Doesn't report EOF on NUL. None of the callers care. */
2459 return (unsigned char)*i->p;
2462 /* FILE-based in_str */
2464 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2465 /* This can be stdin, check line editing char[] buffer */
2466 if (i->p && *i->p != '\0')
2467 return (unsigned char)*i->p;
2469 /* peek_buf[] is an int array, not char. Can contain EOF. */
2470 ch = i->peek_buf[0];
2474 /* Need to get a new char */
2475 ch = fgetc_interactive(i);
2476 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2478 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2479 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2485 i->peek_buf[0] = ch;
2486 /*i->peek_buf[1] = 0; - already is */
2490 /* Only ever called if i_peek() was called, and did not return EOF.
2491 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2492 * not end-of-line. Therefore we never need to read a new editing line here.
2494 static int i_peek2(struct in_str *i)
2498 /* There are two cases when i->p[] buffer exists.
2499 * (1) it's a string in_str.
2500 * (2) It's a file, and we have a saved line editing buffer.
2501 * In both cases, we know that i->p[0] exists and not NUL, and
2502 * the peek2 result is in i->p[1].
2505 return (unsigned char)i->p[1];
2507 /* Now we know it is a file-based in_str. */
2509 /* peek_buf[] is an int array, not char. Can contain EOF. */
2510 /* Is there 2nd char? */
2511 ch = i->peek_buf[1];
2513 /* We did not read it yet, get it now */
2514 do ch = fgetc(i->file); while (ch == '\0');
2515 i->peek_buf[1] = ch;
2518 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2522 static void setup_file_in_str(struct in_str *i, FILE *f)
2524 memset(i, 0, sizeof(*i));
2525 /* i->promptmode = 0; - PS1 (memset did it) */
2530 static void setup_string_in_str(struct in_str *i, const char *s)
2532 memset(i, 0, sizeof(*i));
2533 /* i->promptmode = 0; - PS1 (memset did it) */
2534 /*i->file = NULL */;
2542 #define B_CHUNK (32 * sizeof(char*))
2544 static void o_reset_to_empty_unquoted(o_string *o)
2547 o->has_quoted_part = 0;
2552 static void o_free(o_string *o)
2555 memset(o, 0, sizeof(*o));
2558 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2563 static void o_grow_by(o_string *o, int len)
2565 if (o->length + len > o->maxlen) {
2566 o->maxlen += (2 * len) | (B_CHUNK-1);
2567 o->data = xrealloc(o->data, 1 + o->maxlen);
2571 static void o_addchr(o_string *o, int ch)
2573 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2574 if (o->length < o->maxlen) {
2575 /* likely. avoid o_grow_by() call */
2577 o->data[o->length] = ch;
2579 o->data[o->length] = '\0';
2587 /* Valid only if we know o_string is not empty */
2588 static void o_delchr(o_string *o)
2591 o->data[o->length] = '\0';
2595 static void o_addblock(o_string *o, const char *str, int len)
2598 memcpy(&o->data[o->length], str, len);
2600 o->data[o->length] = '\0';
2603 static void o_addstr(o_string *o, const char *str)
2605 o_addblock(o, str, strlen(str));
2609 static void nommu_addchr(o_string *o, int ch)
2615 # define nommu_addchr(o, str) ((void)0)
2618 static void o_addstr_with_NUL(o_string *o, const char *str)
2620 o_addblock(o, str, strlen(str) + 1);
2624 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2625 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2626 * Apparently, on unquoted $v bash still does globbing
2627 * ("v='*.txt'; echo $v" prints all .txt files),
2628 * but NOT brace expansion! Thus, there should be TWO independent
2629 * quoting mechanisms on $v expansion side: one protects
2630 * $v from brace expansion, and other additionally protects "$v" against globbing.
2631 * We have only second one.
2634 #if ENABLE_HUSH_BRACE_EXPANSION
2635 # define MAYBE_BRACES "{}"
2637 # define MAYBE_BRACES ""
2640 /* My analysis of quoting semantics tells me that state information
2641 * is associated with a destination, not a source.
2643 static void o_addqchr(o_string *o, int ch)
2646 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2651 o->data[o->length] = '\\';
2654 o->data[o->length] = ch;
2656 o->data[o->length] = '\0';
2659 static void o_addQchr(o_string *o, int ch)
2662 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2663 && strchr("*?[\\" MAYBE_BRACES, ch)
2666 o->data[o->length] = '\\';
2670 o->data[o->length] = ch;
2672 o->data[o->length] = '\0';
2675 static void o_addqblock(o_string *o, const char *str, int len)
2680 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2681 if (ordinary_cnt > len) /* paranoia */
2683 o_addblock(o, str, ordinary_cnt);
2684 if (ordinary_cnt == len)
2685 return; /* NUL is already added by o_addblock */
2686 str += ordinary_cnt;
2687 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2691 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2693 o->data[o->length] = '\\';
2697 o->data[o->length] = ch;
2700 o->data[o->length] = '\0';
2703 static void o_addQblock(o_string *o, const char *str, int len)
2705 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2706 o_addblock(o, str, len);
2709 o_addqblock(o, str, len);
2712 static void o_addQstr(o_string *o, const char *str)
2714 o_addQblock(o, str, strlen(str));
2717 /* A special kind of o_string for $VAR and `cmd` expansion.
2718 * It contains char* list[] at the beginning, which is grown in 16 element
2719 * increments. Actual string data starts at the next multiple of 16 * (char*).
2720 * list[i] contains an INDEX (int!) into this string data.
2721 * It means that if list[] needs to grow, data needs to be moved higher up
2722 * but list[i]'s need not be modified.
2723 * NB: remembering how many list[i]'s you have there is crucial.
2724 * o_finalize_list() operation post-processes this structure - calculates
2725 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2727 #if DEBUG_EXPAND || DEBUG_GLOB
2728 static void debug_print_list(const char *prefix, o_string *o, int n)
2730 char **list = (char**)o->data;
2731 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2735 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2736 prefix, list, n, string_start, o->length, o->maxlen,
2737 !!(o->o_expflags & EXP_FLAG_GLOB),
2739 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2742 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2743 o->data + (int)(uintptr_t)list[i] + string_start,
2744 o->data + (int)(uintptr_t)list[i] + string_start);
2748 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2750 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2754 # define debug_print_list(prefix, o, n) ((void)0)
2757 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2758 * in list[n] so that it points past last stored byte so far.
2759 * It returns n+1. */
2760 static int o_save_ptr_helper(o_string *o, int n)
2762 char **list = (char**)o->data;
2766 if (!o->has_empty_slot) {
2767 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2768 string_len = o->length - string_start;
2769 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2770 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2771 /* list[n] points to string_start, make space for 16 more pointers */
2772 o->maxlen += 0x10 * sizeof(list[0]);
2773 o->data = xrealloc(o->data, o->maxlen + 1);
2774 list = (char**)o->data;
2775 memmove(list + n + 0x10, list + n, string_len);
2776 o->length += 0x10 * sizeof(list[0]);
2778 debug_printf_list("list[%d]=%d string_start=%d\n",
2779 n, string_len, string_start);
2782 /* We have empty slot at list[n], reuse without growth */
2783 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2784 string_len = o->length - string_start;
2785 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2786 n, string_len, string_start);
2787 o->has_empty_slot = 0;
2789 o->has_quoted_part = 0;
2790 list[n] = (char*)(uintptr_t)string_len;
2794 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2795 static int o_get_last_ptr(o_string *o, int n)
2797 char **list = (char**)o->data;
2798 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2800 return ((int)(uintptr_t)list[n-1]) + string_start;
2803 #if ENABLE_HUSH_BRACE_EXPANSION
2804 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2805 * first, it processes even {a} (no commas), second,
2806 * I didn't manage to make it return strings when they don't match
2807 * existing files. Need to re-implement it.
2811 static int glob_needed(const char *s)
2820 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2826 /* Return pointer to next closing brace or to comma */
2827 static const char *next_brace_sub(const char *cp)
2831 while (*cp != '\0') {
2838 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2844 return *cp != '\0' ? cp : NULL;
2846 /* Recursive brace globber. Note: may garble pattern[]. */
2847 static int glob_brace(char *pattern, o_string *o, int n)
2849 char *new_pattern_buf;
2856 debug_printf_glob("glob_brace('%s')\n", pattern);
2862 if (*begin == '{') {
2863 /* Find the first sub-pattern and at the same time
2864 * find the rest after the closing brace */
2865 next = next_brace_sub(begin);
2867 /* An illegal expression */
2871 /* "{abc}" with no commas - illegal
2872 * brace expr, disregard and skip it */
2878 if (*begin == '\\' && begin[1] != '\0')
2882 debug_printf_glob("begin:%s\n", begin);
2883 debug_printf_glob("next:%s\n", next);
2885 /* Now find the end of the whole brace expression */
2887 while (*rest != '}') {
2888 rest = next_brace_sub(rest);
2890 /* An illegal expression */
2893 debug_printf_glob("rest:%s\n", rest);
2895 rest_len = strlen(++rest) + 1;
2897 /* We are sure the brace expression is well-formed */
2899 /* Allocate working buffer large enough for our work */
2900 new_pattern_buf = xmalloc(strlen(pattern));
2902 /* We have a brace expression. BEGIN points to the opening {,
2903 * NEXT points past the terminator of the first element, and REST
2904 * points past the final }. We will accumulate result names from
2905 * recursive runs for each brace alternative in the buffer using
2910 /* Construct the new glob expression */
2913 mempcpy(new_pattern_buf,
2914 /* We know the prefix for all sub-patterns */
2915 pattern, begin - pattern),
2919 /* Note: glob_brace() may garble new_pattern_buf[].
2920 * That's why we re-copy prefix every time (1st memcpy above).
2922 n = glob_brace(new_pattern_buf, o, n);
2924 /* We saw the last entry */
2928 next = next_brace_sub(next);
2930 free(new_pattern_buf);
2938 memset(&globdata, 0, sizeof(globdata));
2939 gr = glob(pattern, 0, NULL, &globdata);
2940 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2942 if (gr == GLOB_NOMATCH) {
2943 globfree(&globdata);
2944 /* NB: garbles parameter */
2945 unbackslash(pattern);
2946 o_addstr_with_NUL(o, pattern);
2947 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2948 return o_save_ptr_helper(o, n);
2950 if (gr == GLOB_NOSPACE)
2951 bb_error_msg_and_die(bb_msg_memory_exhausted);
2952 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2953 * but we didn't specify it. Paranoia again. */
2954 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2956 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2957 char **argv = globdata.gl_pathv;
2959 o_addstr_with_NUL(o, *argv);
2960 n = o_save_ptr_helper(o, n);
2966 globfree(&globdata);
2970 /* Performs globbing on last list[],
2971 * saving each result as a new list[].
2973 static int perform_glob(o_string *o, int n)
2975 char *pattern, *copy;
2977 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2979 return o_save_ptr_helper(o, n);
2980 pattern = o->data + o_get_last_ptr(o, n);
2981 debug_printf_glob("glob pattern '%s'\n", pattern);
2982 if (!glob_needed(pattern)) {
2983 /* unbackslash last string in o in place, fix length */
2984 o->length = unbackslash(pattern) - o->data;
2985 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2986 return o_save_ptr_helper(o, n);
2989 copy = xstrdup(pattern);
2990 /* "forget" pattern in o */
2991 o->length = pattern - o->data;
2992 n = glob_brace(copy, o, n);
2995 debug_print_list("perform_glob returning", o, n);
2999 #else /* !HUSH_BRACE_EXPANSION */
3002 static int glob_needed(const char *s)
3011 if (*s == '*' || *s == '[' || *s == '?')
3017 /* Performs globbing on last list[],
3018 * saving each result as a new list[].
3020 static int perform_glob(o_string *o, int n)
3026 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3028 return o_save_ptr_helper(o, n);
3029 pattern = o->data + o_get_last_ptr(o, n);
3030 debug_printf_glob("glob pattern '%s'\n", pattern);
3031 if (!glob_needed(pattern)) {
3033 /* unbackslash last string in o in place, fix length */
3034 o->length = unbackslash(pattern) - o->data;
3035 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3036 return o_save_ptr_helper(o, n);
3039 memset(&globdata, 0, sizeof(globdata));
3040 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3041 * If we glob "*.\*" and don't find anything, we need
3042 * to fall back to using literal "*.*", but GLOB_NOCHECK
3043 * will return "*.\*"!
3045 gr = glob(pattern, 0, NULL, &globdata);
3046 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3048 if (gr == GLOB_NOMATCH) {
3049 globfree(&globdata);
3052 if (gr == GLOB_NOSPACE)
3053 bb_error_msg_and_die(bb_msg_memory_exhausted);
3054 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3055 * but we didn't specify it. Paranoia again. */
3056 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3058 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3059 char **argv = globdata.gl_pathv;
3060 /* "forget" pattern in o */
3061 o->length = pattern - o->data;
3063 o_addstr_with_NUL(o, *argv);
3064 n = o_save_ptr_helper(o, n);
3070 globfree(&globdata);
3072 debug_print_list("perform_glob returning", o, n);
3076 #endif /* !HUSH_BRACE_EXPANSION */
3078 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3079 * Otherwise, just finish current list[] and start new */
3080 static int o_save_ptr(o_string *o, int n)
3082 if (o->o_expflags & EXP_FLAG_GLOB) {
3083 /* If o->has_empty_slot, list[n] was already globbed
3084 * (if it was requested back then when it was filled)
3085 * so don't do that again! */
3086 if (!o->has_empty_slot)
3087 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3089 return o_save_ptr_helper(o, n);
3092 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3093 static char **o_finalize_list(o_string *o, int n)
3098 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3100 debug_print_list("finalized", o, n);
3101 debug_printf_expand("finalized n:%d\n", n);
3102 list = (char**)o->data;
3103 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3107 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3112 static void free_pipe_list(struct pipe *pi);
3114 /* Returns pi->next - next pipe in the list */
3115 static struct pipe *free_pipe(struct pipe *pi)
3120 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3121 for (i = 0; i < pi->num_cmds; i++) {
3122 struct command *command;
3123 struct redir_struct *r, *rnext;
3125 command = &pi->cmds[i];
3126 debug_printf_clean(" command %d:\n", i);
3127 if (command->argv) {
3131 for (a = 0, p = command->argv; *p; a++, p++) {
3132 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3135 free_strings(command->argv);
3136 //command->argv = NULL;
3138 /* not "else if": on syntax error, we may have both! */
3139 if (command->group) {
3140 debug_printf_clean(" begin group (cmd_type:%d)\n",
3142 free_pipe_list(command->group);
3143 debug_printf_clean(" end group\n");
3144 //command->group = NULL;
3146 /* else is crucial here.
3147 * If group != NULL, child_func is meaningless */
3148 #if ENABLE_HUSH_FUNCTIONS
3149 else if (command->child_func) {
3150 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3151 command->child_func->parent_cmd = NULL;
3155 free(command->group_as_string);
3156 //command->group_as_string = NULL;
3158 for (r = command->redirects; r; r = rnext) {
3159 debug_printf_clean(" redirect %d%s",
3160 r->rd_fd, redir_table[r->rd_type].descrip);
3161 /* guard against the case >$FOO, where foo is unset or blank */
3162 if (r->rd_filename) {
3163 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3164 free(r->rd_filename);
3165 //r->rd_filename = NULL;
3167 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3171 //command->redirects = NULL;
3173 free(pi->cmds); /* children are an array, they get freed all at once */
3177 //pi->cmdtext = NULL;
3185 static void free_pipe_list(struct pipe *pi)
3189 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3191 debug_printf_clean("pipe followup code %d\n", pi->followup);
3197 /*** Parsing routines ***/
3199 #ifndef debug_print_tree
3200 static void debug_print_tree(struct pipe *pi, int lvl)
3202 static const char *const PIPE[] = {
3208 static const char *RES[] = {
3209 [RES_NONE ] = "NONE" ,
3212 [RES_THEN ] = "THEN" ,
3213 [RES_ELIF ] = "ELIF" ,
3214 [RES_ELSE ] = "ELSE" ,
3217 # if ENABLE_HUSH_LOOPS
3218 [RES_FOR ] = "FOR" ,
3219 [RES_WHILE] = "WHILE",
3220 [RES_UNTIL] = "UNTIL",
3222 [RES_DONE ] = "DONE" ,
3224 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3227 # if ENABLE_HUSH_CASE
3228 [RES_CASE ] = "CASE" ,
3229 [RES_CASE_IN ] = "CASE_IN" ,
3230 [RES_MATCH] = "MATCH",
3231 [RES_CASE_BODY] = "CASE_BODY",
3232 [RES_ESAC ] = "ESAC" ,
3234 [RES_XXXX ] = "XXXX" ,
3235 [RES_SNTX ] = "SNTX" ,
3237 static const char *const CMDTYPE[] = {
3241 # if ENABLE_HUSH_FUNCTIONS
3250 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3251 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3253 while (prn < pi->num_cmds) {
3254 struct command *command = &pi->cmds[prn];
3255 char **argv = command->argv;
3257 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3259 command->assignment_cnt);
3260 if (command->group) {
3261 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3262 CMDTYPE[command->cmd_type],
3265 , " group_as_string:", command->group_as_string
3270 debug_print_tree(command->group, lvl+1);
3274 if (argv) while (*argv) {
3275 fdprintf(2, " '%s'", *argv);
3285 #endif /* debug_print_tree */
3287 static struct pipe *new_pipe(void)
3290 pi = xzalloc(sizeof(struct pipe));
3291 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3295 /* Command (member of a pipe) is complete, or we start a new pipe
3296 * if ctx->command is NULL.
3297 * No errors possible here.
3299 static int done_command(struct parse_context *ctx)
3301 /* The command is really already in the pipe structure, so
3302 * advance the pipe counter and make a new, null command. */
3303 struct pipe *pi = ctx->pipe;
3304 struct command *command = ctx->command;
3306 #if 0 /* Instead we emit error message at run time */
3307 if (ctx->pending_redirect) {
3308 /* For example, "cmd >" (no filename to redirect to) */
3309 die_if_script("syntax error: %s", "invalid redirect");
3310 ctx->pending_redirect = NULL;
3315 if (IS_NULL_CMD(command)) {
3316 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3320 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3321 //debug_print_tree(ctx->list_head, 20);
3323 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3326 /* Only real trickiness here is that the uncommitted
3327 * command structure is not counted in pi->num_cmds. */
3328 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3329 ctx->command = command = &pi->cmds[pi->num_cmds];
3331 memset(command, 0, sizeof(*command));
3332 return pi->num_cmds; /* used only for 0/nonzero check */
3335 static void done_pipe(struct parse_context *ctx, pipe_style type)
3339 debug_printf_parse("done_pipe entered, followup %d\n", type);
3340 /* Close previous command */
3341 not_null = done_command(ctx);
3342 ctx->pipe->followup = type;
3344 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3345 ctx->ctx_inverted = 0;
3346 ctx->pipe->res_word = ctx->ctx_res_w;
3349 /* Without this check, even just <enter> on command line generates
3350 * tree of three NOPs (!). Which is harmless but annoying.
3351 * IOW: it is safe to do it unconditionally. */
3354 || ctx->ctx_res_w == RES_FI
3356 #if ENABLE_HUSH_LOOPS
3357 || ctx->ctx_res_w == RES_DONE
3358 || ctx->ctx_res_w == RES_FOR
3359 || ctx->ctx_res_w == RES_IN
3361 #if ENABLE_HUSH_CASE
3362 || ctx->ctx_res_w == RES_ESAC
3366 debug_printf_parse("done_pipe: adding new pipe: "
3367 "not_null:%d ctx->ctx_res_w:%d\n",
3368 not_null, ctx->ctx_res_w);
3370 ctx->pipe->next = new_p;
3372 /* RES_THEN, RES_DO etc are "sticky" -
3373 * they remain set for pipes inside if/while.
3374 * This is used to control execution.
3375 * RES_FOR and RES_IN are NOT sticky (needed to support
3376 * cases where variable or value happens to match a keyword):
3378 #if ENABLE_HUSH_LOOPS
3379 if (ctx->ctx_res_w == RES_FOR
3380 || ctx->ctx_res_w == RES_IN)
3381 ctx->ctx_res_w = RES_NONE;
3383 #if ENABLE_HUSH_CASE
3384 if (ctx->ctx_res_w == RES_MATCH)
3385 ctx->ctx_res_w = RES_CASE_BODY;
3386 if (ctx->ctx_res_w == RES_CASE)
3387 ctx->ctx_res_w = RES_CASE_IN;
3389 ctx->command = NULL; /* trick done_command below */
3390 /* Create the memory for command, roughly:
3391 * ctx->pipe->cmds = new struct command;
3392 * ctx->command = &ctx->pipe->cmds[0];
3395 //debug_print_tree(ctx->list_head, 10);
3397 debug_printf_parse("done_pipe return\n");
3400 static void initialize_context(struct parse_context *ctx)
3402 memset(ctx, 0, sizeof(*ctx));
3403 ctx->pipe = ctx->list_head = new_pipe();
3404 /* Create the memory for command, roughly:
3405 * ctx->pipe->cmds = new struct command;
3406 * ctx->command = &ctx->pipe->cmds[0];
3411 /* If a reserved word is found and processed, parse context is modified
3412 * and 1 is returned.
3415 struct reserved_combo {
3418 unsigned char assignment_flag;
3422 FLAG_END = (1 << RES_NONE ),
3424 FLAG_IF = (1 << RES_IF ),
3425 FLAG_THEN = (1 << RES_THEN ),
3426 FLAG_ELIF = (1 << RES_ELIF ),
3427 FLAG_ELSE = (1 << RES_ELSE ),
3428 FLAG_FI = (1 << RES_FI ),
3430 # if ENABLE_HUSH_LOOPS
3431 FLAG_FOR = (1 << RES_FOR ),
3432 FLAG_WHILE = (1 << RES_WHILE),
3433 FLAG_UNTIL = (1 << RES_UNTIL),
3434 FLAG_DO = (1 << RES_DO ),
3435 FLAG_DONE = (1 << RES_DONE ),
3436 FLAG_IN = (1 << RES_IN ),
3438 # if ENABLE_HUSH_CASE
3439 FLAG_MATCH = (1 << RES_MATCH),
3440 FLAG_ESAC = (1 << RES_ESAC ),
3442 FLAG_START = (1 << RES_XXXX ),
3445 static const struct reserved_combo* match_reserved_word(o_string *word)
3447 /* Mostly a list of accepted follow-up reserved words.
3448 * FLAG_END means we are done with the sequence, and are ready
3449 * to turn the compound list into a command.
3450 * FLAG_START means the word must start a new compound list.
3452 static const struct reserved_combo reserved_list[] = {
3454 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3455 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3456 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3457 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3458 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3459 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3461 # if ENABLE_HUSH_LOOPS
3462 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3463 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3464 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3465 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3466 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3467 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3469 # if ENABLE_HUSH_CASE
3470 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3471 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3474 const struct reserved_combo *r;
3476 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3477 if (strcmp(word->data, r->literal) == 0)
3482 /* Return 0: not a keyword, 1: keyword
3484 static int reserved_word(o_string *word, struct parse_context *ctx)
3486 # if ENABLE_HUSH_CASE
3487 static const struct reserved_combo reserved_match = {
3488 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3491 const struct reserved_combo *r;
3493 if (word->has_quoted_part)
3495 r = match_reserved_word(word);
3499 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3500 # if ENABLE_HUSH_CASE
3501 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3502 /* "case word IN ..." - IN part starts first MATCH part */
3503 r = &reserved_match;
3506 if (r->flag == 0) { /* '!' */
3507 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3508 syntax_error("! ! command");
3509 ctx->ctx_res_w = RES_SNTX;
3511 ctx->ctx_inverted = 1;
3514 if (r->flag & FLAG_START) {
3515 struct parse_context *old;
3517 old = xmalloc(sizeof(*old));
3518 debug_printf_parse("push stack %p\n", old);
3519 *old = *ctx; /* physical copy */
3520 initialize_context(ctx);
3522 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3523 syntax_error_at(word->data);
3524 ctx->ctx_res_w = RES_SNTX;
3527 /* "{...} fi" is ok. "{...} if" is not
3529 * if { echo foo; } then { echo bar; } fi */
3530 if (ctx->command->group)
3531 done_pipe(ctx, PIPE_SEQ);
3534 ctx->ctx_res_w = r->res;
3535 ctx->old_flag = r->flag;
3536 word->o_assignment = r->assignment_flag;
3537 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3539 if (ctx->old_flag & FLAG_END) {
3540 struct parse_context *old;
3542 done_pipe(ctx, PIPE_SEQ);
3543 debug_printf_parse("pop stack %p\n", ctx->stack);
3545 old->command->group = ctx->list_head;
3546 old->command->cmd_type = CMD_NORMAL;
3548 /* At this point, the compound command's string is in
3549 * ctx->as_string... except for the leading keyword!
3550 * Consider this example: "echo a | if true; then echo a; fi"
3551 * ctx->as_string will contain "true; then echo a; fi",
3552 * with "if " remaining in old->as_string!
3556 int len = old->as_string.length;
3557 /* Concatenate halves */
3558 o_addstr(&old->as_string, ctx->as_string.data);
3559 o_free_unsafe(&ctx->as_string);
3560 /* Find where leading keyword starts in first half */
3561 str = old->as_string.data + len;
3562 if (str > old->as_string.data)
3563 str--; /* skip whitespace after keyword */
3564 while (str > old->as_string.data && isalpha(str[-1]))
3566 /* Ugh, we're done with this horrid hack */
3567 old->command->group_as_string = xstrdup(str);
3568 debug_printf_parse("pop, remembering as:'%s'\n",
3569 old->command->group_as_string);
3572 *ctx = *old; /* physical copy */
3577 #endif /* HAS_KEYWORDS */
3579 /* Word is complete, look at it and update parsing context.
3580 * Normal return is 0. Syntax errors return 1.
3581 * Note: on return, word is reset, but not o_free'd!
3583 static int done_word(o_string *word, struct parse_context *ctx)
3585 struct command *command = ctx->command;
3587 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3588 if (word->length == 0 && !word->has_quoted_part) {
3589 debug_printf_parse("done_word return 0: true null, ignored\n");
3593 if (ctx->pending_redirect) {
3594 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3595 * only if run as "bash", not "sh" */
3596 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3598 * ...the word that follows the redirection operator
3599 * shall be subjected to tilde expansion, parameter expansion,
3600 * command substitution, arithmetic expansion, and quote
3601 * removal. Pathname expansion shall not be performed
3602 * on the word by a non-interactive shell; an interactive
3603 * shell may perform it, but shall do so only when
3604 * the expansion would result in one word."
3606 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3607 /* Cater for >\file case:
3608 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3609 * Same with heredocs:
3610 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3612 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3613 unbackslash(ctx->pending_redirect->rd_filename);
3614 /* Is it <<"HEREDOC"? */
3615 if (word->has_quoted_part) {
3616 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3619 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3620 ctx->pending_redirect = NULL;
3623 # if ENABLE_HUSH_CASE
3624 if (ctx->ctx_dsemicolon
3625 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3627 /* already done when ctx_dsemicolon was set to 1: */
3628 /* ctx->ctx_res_w = RES_MATCH; */
3629 ctx->ctx_dsemicolon = 0;
3632 if (!command->argv /* if it's the first word... */
3633 # if ENABLE_HUSH_LOOPS
3634 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3635 && ctx->ctx_res_w != RES_IN
3637 # if ENABLE_HUSH_CASE
3638 && ctx->ctx_res_w != RES_CASE
3641 int reserved = reserved_word(word, ctx);
3642 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3644 o_reset_to_empty_unquoted(word);
3645 debug_printf_parse("done_word return %d\n",
3646 (ctx->ctx_res_w == RES_SNTX));
3647 return (ctx->ctx_res_w == RES_SNTX);
3649 # if ENABLE_HUSH_BASH_COMPAT
3650 if (strcmp(word->data, "[[") == 0) {
3651 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3657 if (command->group) {
3658 /* "{ echo foo; } echo bar" - bad */
3659 syntax_error_at(word->data);
3660 debug_printf_parse("done_word return 1: syntax error, "
3661 "groups and arglists don't mix\n");
3665 /* If this word wasn't an assignment, next ones definitely
3666 * can't be assignments. Even if they look like ones. */
3667 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3668 && word->o_assignment != WORD_IS_KEYWORD
3670 word->o_assignment = NOT_ASSIGNMENT;
3672 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3673 command->assignment_cnt++;
3674 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3676 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3677 word->o_assignment = MAYBE_ASSIGNMENT;
3679 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3681 if (word->has_quoted_part
3682 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3683 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3684 /* (otherwise it's known to be not empty and is already safe) */
3686 /* exclude "$@" - it can expand to no word despite "" */
3687 char *p = word->data;
3688 while (p[0] == SPECIAL_VAR_SYMBOL
3689 && (p[1] & 0x7f) == '@'
3690 && p[2] == SPECIAL_VAR_SYMBOL
3695 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3696 debug_print_strings("word appended to argv", command->argv);
3699 #if ENABLE_HUSH_LOOPS
3700 if (ctx->ctx_res_w == RES_FOR) {
3701 if (word->has_quoted_part
3702 || !is_well_formed_var_name(command->argv[0], '\0')
3704 /* bash says just "not a valid identifier" */
3705 syntax_error("not a valid identifier in for");
3708 /* Force FOR to have just one word (variable name) */
3709 /* NB: basically, this makes hush see "for v in ..."
3710 * syntax as if it is "for v; in ...". FOR and IN become
3711 * two pipe structs in parse tree. */
3712 done_pipe(ctx, PIPE_SEQ);
3715 #if ENABLE_HUSH_CASE
3716 /* Force CASE to have just one word */
3717 if (ctx->ctx_res_w == RES_CASE) {
3718 done_pipe(ctx, PIPE_SEQ);
3722 o_reset_to_empty_unquoted(word);
3724 debug_printf_parse("done_word return 0\n");
3729 /* Peek ahead in the input to find out if we have a "&n" construct,
3730 * as in "2>&1", that represents duplicating a file descriptor.
3732 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3733 * REDIRFD_SYNTAX_ERR if syntax error,
3734 * REDIRFD_TO_FILE if no & was seen,
3735 * or the number found.
3738 #define parse_redir_right_fd(as_string, input) \
3739 parse_redir_right_fd(input)
3741 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3747 return REDIRFD_TO_FILE;
3749 ch = i_getch(input); /* get the & */
3750 nommu_addchr(as_string, ch);
3753 ch = i_getch(input);
3754 nommu_addchr(as_string, ch);
3755 return REDIRFD_CLOSE;
3759 while (ch != EOF && isdigit(ch)) {
3760 d = d*10 + (ch-'0');
3762 ch = i_getch(input);
3763 nommu_addchr(as_string, ch);
3768 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3770 bb_error_msg("ambiguous redirect");
3771 return REDIRFD_SYNTAX_ERR;
3774 /* Return code is 0 normal, 1 if a syntax error is detected
3776 static int parse_redirect(struct parse_context *ctx,
3779 struct in_str *input)
3781 struct command *command = ctx->command;
3782 struct redir_struct *redir;
3783 struct redir_struct **redirp;
3786 dup_num = REDIRFD_TO_FILE;
3787 if (style != REDIRECT_HEREDOC) {
3788 /* Check for a '>&1' type redirect */
3789 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3790 if (dup_num == REDIRFD_SYNTAX_ERR)
3793 int ch = i_peek(input);
3794 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3795 if (dup_num) { /* <<-... */
3796 ch = i_getch(input);
3797 nommu_addchr(&ctx->as_string, ch);
3802 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3803 int ch = i_peek(input);
3805 /* >|FILE redirect ("clobbering" >).
3806 * Since we do not support "set -o noclobber" yet,
3807 * >| and > are the same for now. Just eat |.
3809 ch = i_getch(input);
3810 nommu_addchr(&ctx->as_string, ch);
3814 /* Create a new redir_struct and append it to the linked list */
3815 redirp = &command->redirects;
3816 while ((redir = *redirp) != NULL) {
3817 redirp = &(redir->next);
3819 *redirp = redir = xzalloc(sizeof(*redir));
3820 /* redir->next = NULL; */
3821 /* redir->rd_filename = NULL; */
3822 redir->rd_type = style;
3823 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3825 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3826 redir_table[style].descrip);
3828 redir->rd_dup = dup_num;
3829 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3830 /* Erik had a check here that the file descriptor in question
3831 * is legit; I postpone that to "run time"
3832 * A "-" representation of "close me" shows up as a -3 here */
3833 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3834 redir->rd_fd, redir->rd_dup);
3836 #if 0 /* Instead we emit error message at run time */
3837 if (ctx->pending_redirect) {
3838 /* For example, "cmd > <file" */
3839 die_if_script("syntax error: %s", "invalid redirect");
3842 /* Set ctx->pending_redirect, so we know what to do at the
3843 * end of the next parsed word. */
3844 ctx->pending_redirect = redir;
3849 /* If a redirect is immediately preceded by a number, that number is
3850 * supposed to tell which file descriptor to redirect. This routine
3851 * looks for such preceding numbers. In an ideal world this routine
3852 * needs to handle all the following classes of redirects...
3853 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3854 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3855 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3856 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3858 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3860 * ... If n is quoted, the number shall not be recognized as part of
3861 * the redirection expression. For example:
3863 * writes the character 2 into file a"
3864 * We are getting it right by setting ->has_quoted_part on any \<char>
3866 * A -1 return means no valid number was found,
3867 * the caller should use the appropriate default for this redirection.
3869 static int redirect_opt_num(o_string *o)
3873 if (o->data == NULL)
3875 num = bb_strtou(o->data, NULL, 10);
3876 if (errno || num < 0)
3878 o_reset_to_empty_unquoted(o);
3883 #define fetch_till_str(as_string, input, word, skip_tabs) \
3884 fetch_till_str(input, word, skip_tabs)
3886 static char *fetch_till_str(o_string *as_string,
3887 struct in_str *input,
3891 o_string heredoc = NULL_O_STRING;
3893 int prev = 0; /* not \ */
3899 ch = i_getch(input);
3901 nommu_addchr(as_string, ch);
3902 if ((ch == '\n' || ch == EOF)
3903 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3905 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3906 heredoc.data[past_EOL] = '\0';
3907 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3908 return heredoc.data;
3910 while (ch == '\n') {
3911 o_addchr(&heredoc, ch);
3914 past_EOL = heredoc.length;
3916 ch = i_getch(input);
3918 nommu_addchr(as_string, ch);
3919 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3923 o_free_unsafe(&heredoc);
3926 o_addchr(&heredoc, ch);
3927 nommu_addchr(as_string, ch);
3928 if (prev == '\\' && ch == '\\')
3929 /* Correctly handle foo\\<eol> (not a line cont.) */
3930 prev = 0; /* not \ */
3936 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3937 * and load them all. There should be exactly heredoc_cnt of them.
3939 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3941 struct pipe *pi = ctx->list_head;
3943 while (pi && heredoc_cnt) {
3945 struct command *cmd = pi->cmds;
3947 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3949 cmd->argv ? cmd->argv[0] : "NONE");
3950 for (i = 0; i < pi->num_cmds; i++) {
3951 struct redir_struct *redir = cmd->redirects;
3953 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3954 i, cmd->argv ? cmd->argv[0] : "NONE");
3956 if (redir->rd_type == REDIRECT_HEREDOC) {
3959 redir->rd_type = REDIRECT_HEREDOC2;
3960 /* redir->rd_dup is (ab)used to indicate <<- */
3961 p = fetch_till_str(&ctx->as_string, input,
3962 redir->rd_filename, redir->rd_dup);
3964 syntax_error("unexpected EOF in here document");
3967 free(redir->rd_filename);
3968 redir->rd_filename = p;
3971 redir = redir->next;
3978 /* Should be 0. If it isn't, it's a parse error */
3980 bb_error_msg_and_die("heredoc BUG 2");
3986 static int run_list(struct pipe *pi);
3988 #define parse_stream(pstring, input, end_trigger) \
3989 parse_stream(input, end_trigger)
3991 static struct pipe *parse_stream(char **pstring,
3992 struct in_str *input,
3996 #if !ENABLE_HUSH_FUNCTIONS
3997 #define parse_group(dest, ctx, input, ch) \
3998 parse_group(ctx, input, ch)
4000 static int parse_group(o_string *dest, struct parse_context *ctx,
4001 struct in_str *input, int ch)
4003 /* dest contains characters seen prior to ( or {.
4004 * Typically it's empty, but for function defs,
4005 * it contains function name (without '()'). */
4006 struct pipe *pipe_list;
4008 struct command *command = ctx->command;
4010 debug_printf_parse("parse_group entered\n");
4011 #if ENABLE_HUSH_FUNCTIONS
4012 if (ch == '(' && !dest->has_quoted_part) {
4014 if (done_word(dest, ctx))
4017 goto skip; /* (... */
4018 if (command->argv[1]) { /* word word ... (... */
4019 syntax_error_unexpected_ch('(');
4022 /* it is "word(..." or "word (..." */
4024 ch = i_getch(input);
4025 while (ch == ' ' || ch == '\t');
4027 syntax_error_unexpected_ch(ch);
4030 nommu_addchr(&ctx->as_string, ch);
4032 ch = i_getch(input);
4033 while (ch == ' ' || ch == '\t' || ch == '\n');
4035 syntax_error_unexpected_ch(ch);
4038 nommu_addchr(&ctx->as_string, ch);
4039 command->cmd_type = CMD_FUNCDEF;
4044 #if 0 /* Prevented by caller */
4045 if (command->argv /* word [word]{... */
4046 || dest->length /* word{... */
4047 || dest->has_quoted_part /* ""{... */
4050 debug_printf_parse("parse_group return 1: "
4051 "syntax error, groups and arglists don't mix\n");
4056 #if ENABLE_HUSH_FUNCTIONS
4062 command->cmd_type = CMD_SUBSHELL;
4064 /* bash does not allow "{echo...", requires whitespace */
4066 if (ch != ' ' && ch != '\t' && ch != '\n'
4067 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4069 syntax_error_unexpected_ch(ch);
4073 ch = i_getch(input);
4074 nommu_addchr(&ctx->as_string, ch);
4080 # define as_string NULL
4082 char *as_string = NULL;
4084 pipe_list = parse_stream(&as_string, input, endch);
4087 o_addstr(&ctx->as_string, as_string);
4089 /* empty ()/{} or parse error? */
4090 if (!pipe_list || pipe_list == ERR_PTR) {
4091 /* parse_stream already emitted error msg */
4094 debug_printf_parse("parse_group return 1: "
4095 "parse_stream returned %p\n", pipe_list);
4098 command->group = pipe_list;
4100 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4101 command->group_as_string = as_string;
4102 debug_printf_parse("end of group, remembering as:'%s'\n",
4103 command->group_as_string);
4107 debug_printf_parse("parse_group return 0\n");
4109 /* command remains "open", available for possible redirects */
4112 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4117 ch = i_getch(input);
4120 ch2 = i_peek(input);
4123 /* backslash+newline, skip it */
4128 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4136 ch2 = i_peek2(input);
4139 /* backslash+newline, skip it */
4145 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4146 /* Subroutines for copying $(...) and `...` things */
4147 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4149 static int add_till_single_quote(o_string *dest, struct in_str *input)
4152 int ch = i_getch(input);
4154 syntax_error_unterm_ch('\'');
4162 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4163 static int add_till_double_quote(o_string *dest, struct in_str *input)
4166 int ch = i_getch(input);
4168 syntax_error_unterm_ch('"');
4173 if (ch == '\\') { /* \x. Copy both chars. */
4175 ch = i_getch(input);
4179 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4184 //if (ch == '$') ...
4187 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4189 * "Within the backquoted style of command substitution, backslash
4190 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4191 * The search for the matching backquote shall be satisfied by the first
4192 * backquote found without a preceding backslash; during this search,
4193 * if a non-escaped backquote is encountered within a shell comment,
4194 * a here-document, an embedded command substitution of the $(command)
4195 * form, or a quoted string, undefined results occur. A single-quoted
4196 * or double-quoted string that begins, but does not end, within the
4197 * "`...`" sequence produces undefined results."
4199 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4201 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4204 int ch = i_getch(input);
4208 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4209 ch = i_getch(input);
4213 && (!in_dquote || ch != '"')
4215 o_addchr(dest, '\\');
4219 syntax_error_unterm_ch('`');
4225 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4226 * quoting and nested ()s.
4227 * "With the $(command) style of command substitution, all characters
4228 * following the open parenthesis to the matching closing parenthesis
4229 * constitute the command. Any valid shell script can be used for command,
4230 * except a script consisting solely of redirections which produces
4231 * unspecified results."
4233 * echo $(echo '(TEST)' BEST) (TEST) BEST
4234 * echo $(echo 'TEST)' BEST) TEST) BEST
4235 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4237 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4238 * can contain arbitrary constructs, just like $(cmd).
4239 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4240 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4242 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4243 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4246 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4247 # if ENABLE_HUSH_BASH_COMPAT
4248 char end_char2 = end_ch >> 8;
4250 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4253 ch = i_getch(input);
4255 syntax_error_unterm_ch(end_ch);
4258 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4261 /* we look for closing )) of $((EXPR)) */
4262 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4263 i_getch(input); /* eat second ')' */
4268 if (ch == '(' || ch == '{') {
4269 ch = (ch == '(' ? ')' : '}');
4270 if (!add_till_closing_bracket(dest, input, ch))
4276 if (!add_till_single_quote(dest, input))
4282 if (!add_till_double_quote(dest, input))
4288 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4294 /* \x. Copy verbatim. Important for \(, \) */
4295 ch = i_getch(input);
4297 syntax_error_unterm_ch(')');
4302 /* "backslash+newline", ignore both */
4303 o_delchr(dest); /* undo insertion of '\' */
4313 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4315 /* Return code: 0 for OK, 1 for syntax error */
4317 #define parse_dollar(as_string, dest, input, quote_mask) \
4318 parse_dollar(dest, input, quote_mask)
4319 #define as_string NULL
4321 static int parse_dollar(o_string *as_string,
4323 struct in_str *input, unsigned char quote_mask)
4325 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4327 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4329 ch = i_getch(input);
4330 nommu_addchr(as_string, ch);
4332 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4334 debug_printf_parse(": '%c'\n", ch);
4335 o_addchr(dest, ch | quote_mask);
4337 ch = i_peek_and_eat_bkslash_nl(input);
4338 if (!isalnum(ch) && ch != '_') {
4339 /* End of variable name reached */
4342 ch = i_getch(input);
4343 nommu_addchr(as_string, ch);
4345 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4346 } else if (isdigit(ch)) {
4348 ch = i_getch(input);
4349 nommu_addchr(as_string, ch);
4350 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4351 debug_printf_parse(": '%c'\n", ch);
4352 o_addchr(dest, ch | quote_mask);
4353 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4354 } else switch (ch) {
4356 case '!': /* last bg pid */
4357 case '?': /* last exit code */
4358 case '#': /* number of args */
4359 case '*': /* args */
4360 case '@': /* args */
4361 goto make_one_char_var;
4363 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4365 ch = i_getch(input); /* eat '{' */
4366 nommu_addchr(as_string, ch);
4368 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4369 /* It should be ${?}, or ${#var},
4370 * or even ${?+subst} - operator acting on a special variable,
4371 * or the beginning of variable name.
4374 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4377 syntax_error_unterm_str("${name}");
4378 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4381 nommu_addchr(as_string, ch);
4384 /* It's possible to just call add_till_closing_bracket() at this point.
4385 * However, this regresses some of our testsuite cases
4386 * which check invalid constructs like ${%}.
4387 * Oh well... let's check that the var name part is fine... */
4393 debug_printf_parse(": '%c'\n", ch);
4395 ch = i_getch(input);
4396 nommu_addchr(as_string, ch);
4400 if (!isalnum(ch) && ch != '_') {
4402 unsigned char last_ch;
4403 /* handle parameter expansions
4404 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4406 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4407 goto bad_dollar_syntax;
4409 /* Eat everything until closing '}' (or ':') */
4411 if (ENABLE_HUSH_BASH_COMPAT
4413 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4415 /* It's ${var:N[:M]} thing */
4416 end_ch = '}' * 0x100 + ':';
4418 if (ENABLE_HUSH_BASH_COMPAT
4421 /* It's ${var/[/]pattern[/repl]} thing */
4422 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4424 nommu_addchr(as_string, '/');
4427 end_ch = '}' * 0x100 + '/';
4433 #if ENABLE_HUSH_DOLLAR_OPS
4434 last_ch = add_till_closing_bracket(dest, input, end_ch);
4435 if (last_ch == 0) /* error? */
4438 #error Simple code to only allow ${var} is not implemented
4441 o_addstr(as_string, dest->data + pos);
4442 o_addchr(as_string, last_ch);
4445 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4446 /* close the first block: */
4447 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4448 /* while parsing N from ${var:N[:M]}
4449 * or pattern from ${var/[/]pattern[/repl]} */
4450 if ((end_ch & 0xff) == last_ch) {
4451 /* got ':' or '/'- parse the rest */
4456 if (end_ch == '}' * 0x100 + ':') {
4457 /* it's ${var:N} - emulate :999999999 */
4458 o_addstr(dest, "999999999");
4459 } /* else: it's ${var/[/]pattern} */
4464 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4467 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4471 ch = i_getch(input);
4472 nommu_addchr(as_string, ch);
4473 # if ENABLE_FEATURE_SH_MATH
4474 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4475 ch = i_getch(input);
4476 nommu_addchr(as_string, ch);
4477 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4478 o_addchr(dest, /*quote_mask |*/ '+');
4481 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4482 return 0; /* error */
4484 o_addstr(as_string, dest->data + pos);
4485 o_addchr(as_string, ')');
4486 o_addchr(as_string, ')');
4488 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4492 # if ENABLE_HUSH_TICK
4493 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4494 o_addchr(dest, quote_mask | '`');
4497 if (!add_till_closing_bracket(dest, input, ')'))
4498 return 0; /* error */
4500 o_addstr(as_string, dest->data + pos);
4501 o_addchr(as_string, ')');
4503 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4509 ch = i_getch(input);
4510 nommu_addchr(as_string, ch);
4511 ch = i_peek_and_eat_bkslash_nl(input);
4512 if (isalnum(ch)) { /* it's $_name or $_123 */
4517 /* TODO: $_ and $-: */
4518 /* $_ Shell or shell script name; or last argument of last command
4519 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4520 * but in command's env, set to full pathname used to invoke it */
4521 /* $- Option flags set by set builtin or shell options (-i etc) */
4523 o_addQchr(dest, '$');
4525 debug_printf_parse("parse_dollar return 1 (ok)\n");
4531 # if ENABLE_HUSH_BASH_COMPAT
4532 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4533 encode_string(dest, input, dquote_end, process_bkslash)
4535 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4536 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4537 encode_string(dest, input, dquote_end)
4539 #define as_string NULL
4543 # if ENABLE_HUSH_BASH_COMPAT
4544 /* all parameters are needed, no macro tricks */
4546 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4547 encode_string(as_string, dest, input, dquote_end)
4550 static int encode_string(o_string *as_string,
4552 struct in_str *input,
4554 int process_bkslash)
4556 #if !ENABLE_HUSH_BASH_COMPAT
4557 const int process_bkslash = 1;
4563 ch = i_getch(input);
4565 nommu_addchr(as_string, ch);
4566 if (ch == dquote_end) { /* may be only '"' or EOF */
4567 debug_printf_parse("encode_string return 1 (ok)\n");
4570 /* note: can't move it above ch == dquote_end check! */
4572 syntax_error_unterm_ch('"');
4573 return 0; /* error */
4577 next = i_peek(input);
4579 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4580 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4581 if (process_bkslash && ch == '\\') {
4583 syntax_error("\\<eof>");
4587 * "The backslash retains its special meaning [in "..."]
4588 * only when followed by one of the following characters:
4589 * $, `, ", \, or <newline>. A double quote may be quoted
4590 * within double quotes by preceding it with a backslash."
4591 * NB: in (unquoted) heredoc, above does not apply to ",
4592 * therefore we check for it by "next == dquote_end" cond.
4594 if (next == dquote_end || strchr("$`\\\n", next)) {
4595 ch = i_getch(input); /* eat next */
4597 goto again; /* skip \<newline> */
4598 } /* else: ch remains == '\\', and we double it below: */
4599 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4600 nommu_addchr(as_string, ch);
4604 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4605 debug_printf_parse("encode_string return 0: "
4606 "parse_dollar returned 0 (error)\n");
4611 #if ENABLE_HUSH_TICK
4613 //unsigned pos = dest->length;
4614 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4615 o_addchr(dest, 0x80 | '`');
4616 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4617 return 0; /* error */
4618 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4619 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4623 o_addQchr(dest, ch);
4629 * Scan input until EOF or end_trigger char.
4630 * Return a list of pipes to execute, or NULL on EOF
4631 * or if end_trigger character is met.
4632 * On syntax error, exit if shell is not interactive,
4633 * reset parsing machinery and start parsing anew,
4634 * or return ERR_PTR.
4636 static struct pipe *parse_stream(char **pstring,
4637 struct in_str *input,
4640 struct parse_context ctx;
4641 o_string dest = NULL_O_STRING;
4644 /* Single-quote triggers a bypass of the main loop until its mate is
4645 * found. When recursing, quote state is passed in via dest->o_expflags.
4647 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4648 end_trigger ? end_trigger : 'X');
4651 /* If very first arg is "" or '', dest.data may end up NULL.
4652 * Preventing this: */
4653 o_addchr(&dest, '\0');
4656 /* We used to separate words on $IFS here. This was wrong.
4657 * $IFS is used only for word splitting when $var is expanded,
4658 * here we should use blank chars as separators, not $IFS
4661 if (MAYBE_ASSIGNMENT != 0)
4662 dest.o_assignment = MAYBE_ASSIGNMENT;
4663 initialize_context(&ctx);
4666 const char *is_blank;
4667 const char *is_special;
4671 redir_type redir_style;
4673 ch = i_getch(input);
4674 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4675 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4680 syntax_error_unterm_str("here document");
4683 if (end_trigger == ')') {
4684 syntax_error_unterm_ch('(');
4687 if (end_trigger == '}') {
4688 syntax_error_unterm_ch('{');
4692 if (done_word(&dest, &ctx)) {
4696 done_pipe(&ctx, PIPE_SEQ);
4698 /* If we got nothing... */
4699 /* (this makes bare "&" cmd a no-op.
4700 * bash says: "syntax error near unexpected token '&'") */
4701 if (pi->num_cmds == 0
4702 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4708 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4710 *pstring = ctx.as_string.data;
4712 o_free_unsafe(&ctx.as_string);
4715 debug_printf_parse("parse_stream return %p\n", pi);
4718 nommu_addchr(&ctx.as_string, ch);
4722 next = i_peek(input);
4724 is_special = "{}<>;&|()#'" /* special outside of "str" */
4725 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4726 /* Are { and } special here? */
4727 if (ctx.command->argv /* word [word]{... - non-special */
4728 || dest.length /* word{... - non-special */
4729 || dest.has_quoted_part /* ""{... - non-special */
4730 || (next != ';' /* }; - special */
4731 && next != ')' /* }) - special */
4732 && next != '(' /* {( - special */
4733 && next != '&' /* }& and }&& ... - special */
4734 && next != '|' /* }|| ... - special */
4735 && !strchr(defifs, next) /* {word - non-special */
4738 /* They are not special, skip "{}" */
4741 is_special = strchr(is_special, ch);
4742 is_blank = strchr(defifs, ch);
4744 if (!is_special && !is_blank) { /* ordinary char */
4746 o_addQchr(&dest, ch);
4747 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4748 || dest.o_assignment == WORD_IS_KEYWORD)
4750 && is_well_formed_var_name(dest.data, '=')
4752 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4753 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4759 if (done_word(&dest, &ctx)) {
4763 /* Is this a case when newline is simply ignored?
4765 * "cmd | <newline> cmd ..."
4766 * "case ... in <newline> word) ..."
4768 if (IS_NULL_CMD(ctx.command)
4769 && dest.length == 0 && !dest.has_quoted_part
4771 /* This newline can be ignored. But...
4772 * Without check #1, interactive shell
4773 * ignores even bare <newline>,
4774 * and shows the continuation prompt:
4775 * ps1_prompt$ <enter>
4776 * ps2> _ <=== wrong, should be ps1
4777 * Without check #2, "cmd & <newline>"
4778 * is similarly mistreated.
4779 * (BTW, this makes "cmd & cmd"
4780 * and "cmd && cmd" non-orthogonal.
4781 * Really, ask yourself, why
4782 * "cmd && <newline>" doesn't start
4783 * cmd but waits for more input?
4786 struct pipe *pi = ctx.list_head;
4787 if (pi->num_cmds != 0 /* check #1 */
4788 && pi->followup != PIPE_BG /* check #2 */
4793 /* Treat newline as a command separator. */
4794 done_pipe(&ctx, PIPE_SEQ);
4795 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4797 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4802 dest.o_assignment = MAYBE_ASSIGNMENT;
4803 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4805 /* note: if (is_blank) continue;
4806 * will still trigger for us */
4810 /* "cmd}" or "cmd }..." without semicolon or &:
4811 * } is an ordinary char in this case, even inside { cmd; }
4812 * Pathological example: { ""}; } should exec "}" cmd
4815 if (dest.length != 0 /* word} */
4816 || dest.has_quoted_part /* ""} */
4820 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4821 /* Generally, there should be semicolon: "cmd; }"
4822 * However, bash allows to omit it if "cmd" is
4823 * a group. Examples:
4826 * { echo 0 >&2 | { echo 1; } }
4827 * { while false; do :; done }
4828 * { case a in b) ;; esac }
4830 if (ctx.command->group)
4834 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4835 /* Can't be an end of {cmd}, skip the check */
4836 goto skip_end_trigger;
4837 /* else: } does terminate a group */
4840 if (end_trigger && end_trigger == ch
4841 && (ch != ';' || heredoc_cnt == 0)
4842 #if ENABLE_HUSH_CASE
4844 || ctx.ctx_res_w != RES_MATCH
4845 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4850 /* This is technically valid:
4851 * { cat <<HERE; }; echo Ok
4855 * but we don't support this.
4856 * We require heredoc to be in enclosing {}/(),
4859 syntax_error_unterm_str("here document");
4862 if (done_word(&dest, &ctx)) {
4865 done_pipe(&ctx, PIPE_SEQ);
4866 dest.o_assignment = MAYBE_ASSIGNMENT;
4867 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4868 /* Do we sit outside of any if's, loops or case's? */
4870 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4874 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4876 *pstring = ctx.as_string.data;
4878 o_free_unsafe(&ctx.as_string);
4881 debug_printf_parse("parse_stream return %p: "
4882 "end_trigger char found\n",
4884 return ctx.list_head;
4891 /* Catch <, > before deciding whether this word is
4892 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4895 redir_fd = redirect_opt_num(&dest);
4896 if (done_word(&dest, &ctx)) {
4899 redir_style = REDIRECT_OVERWRITE;
4901 redir_style = REDIRECT_APPEND;
4902 ch = i_getch(input);
4903 nommu_addchr(&ctx.as_string, ch);
4906 else if (next == '(') {
4907 syntax_error(">(process) not supported");
4911 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4913 continue; /* back to top of while (1) */
4915 redir_fd = redirect_opt_num(&dest);
4916 if (done_word(&dest, &ctx)) {
4919 redir_style = REDIRECT_INPUT;
4921 redir_style = REDIRECT_HEREDOC;
4923 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4924 ch = i_getch(input);
4925 nommu_addchr(&ctx.as_string, ch);
4926 } else if (next == '>') {
4927 redir_style = REDIRECT_IO;
4928 ch = i_getch(input);
4929 nommu_addchr(&ctx.as_string, ch);
4932 else if (next == '(') {
4933 syntax_error("<(process) not supported");
4937 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4939 continue; /* back to top of while (1) */
4941 if (dest.length == 0 && !dest.has_quoted_part) {
4942 /* skip "#comment" */
4945 if (ch == EOF || ch == '\n')
4948 /* note: we do not add it to &ctx.as_string */
4950 nommu_addchr(&ctx.as_string, '\n');
4951 continue; /* back to top of while (1) */
4956 /* It's "\<newline>" */
4958 /* Remove trailing '\' from ctx.as_string */
4959 ctx.as_string.data[--ctx.as_string.length] = '\0';
4961 ch = i_getch(input); /* eat it */
4962 continue; /* back to top of while (1) */
4967 if (dest.o_assignment == MAYBE_ASSIGNMENT
4968 /* check that we are not in word in "a=1 2>word b=1": */
4969 && !ctx.pending_redirect
4971 /* ch is a special char and thus this word
4972 * cannot be an assignment */
4973 dest.o_assignment = NOT_ASSIGNMENT;
4974 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4977 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4980 case '#': /* non-comment #: "echo a#b" etc */
4981 o_addQchr(&dest, ch);
4985 syntax_error("\\<eof>");
4988 ch = i_getch(input);
4989 /* note: ch != '\n' (that case does not reach this place) */
4990 o_addchr(&dest, '\\');
4991 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4992 o_addchr(&dest, ch);
4993 nommu_addchr(&ctx.as_string, ch);
4994 /* Example: echo Hello \2>file
4995 * we need to know that word 2 is quoted */
4996 dest.has_quoted_part = 1;
4999 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5000 debug_printf_parse("parse_stream parse error: "
5001 "parse_dollar returned 0 (error)\n");
5006 dest.has_quoted_part = 1;
5007 if (next == '\'' && !ctx.pending_redirect) {
5008 insert_empty_quoted_str_marker:
5009 nommu_addchr(&ctx.as_string, next);
5010 i_getch(input); /* eat second ' */
5011 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5012 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5015 ch = i_getch(input);
5017 syntax_error_unterm_ch('\'');
5020 nommu_addchr(&ctx.as_string, ch);
5023 o_addqchr(&dest, ch);
5028 dest.has_quoted_part = 1;
5029 if (next == '"' && !ctx.pending_redirect)
5030 goto insert_empty_quoted_str_marker;
5031 if (dest.o_assignment == NOT_ASSIGNMENT)
5032 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5033 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5035 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5037 #if ENABLE_HUSH_TICK
5039 USE_FOR_NOMMU(unsigned pos;)
5041 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5042 o_addchr(&dest, '`');
5043 USE_FOR_NOMMU(pos = dest.length;)
5044 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5047 o_addstr(&ctx.as_string, dest.data + pos);
5048 o_addchr(&ctx.as_string, '`');
5050 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5051 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5056 #if ENABLE_HUSH_CASE
5059 if (done_word(&dest, &ctx)) {
5062 done_pipe(&ctx, PIPE_SEQ);
5063 #if ENABLE_HUSH_CASE
5064 /* Eat multiple semicolons, detect
5065 * whether it means something special */
5070 ch = i_getch(input);
5071 nommu_addchr(&ctx.as_string, ch);
5072 if (ctx.ctx_res_w == RES_CASE_BODY) {
5073 ctx.ctx_dsemicolon = 1;
5074 ctx.ctx_res_w = RES_MATCH;
5080 /* We just finished a cmd. New one may start
5081 * with an assignment */
5082 dest.o_assignment = MAYBE_ASSIGNMENT;
5083 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5086 if (done_word(&dest, &ctx)) {
5090 ch = i_getch(input);
5091 nommu_addchr(&ctx.as_string, ch);
5092 done_pipe(&ctx, PIPE_AND);
5094 done_pipe(&ctx, PIPE_BG);
5098 if (done_word(&dest, &ctx)) {
5101 #if ENABLE_HUSH_CASE
5102 if (ctx.ctx_res_w == RES_MATCH)
5103 break; /* we are in case's "word | word)" */
5105 if (next == '|') { /* || */
5106 ch = i_getch(input);
5107 nommu_addchr(&ctx.as_string, ch);
5108 done_pipe(&ctx, PIPE_OR);
5110 /* we could pick up a file descriptor choice here
5111 * with redirect_opt_num(), but bash doesn't do it.
5112 * "echo foo 2| cat" yields "foo 2". */
5117 #if ENABLE_HUSH_CASE
5118 /* "case... in [(]word)..." - skip '(' */
5119 if (ctx.ctx_res_w == RES_MATCH
5120 && ctx.command->argv == NULL /* not (word|(... */
5121 && dest.length == 0 /* not word(... */
5122 && dest.has_quoted_part == 0 /* not ""(... */
5128 if (parse_group(&dest, &ctx, input, ch) != 0) {
5133 #if ENABLE_HUSH_CASE
5134 if (ctx.ctx_res_w == RES_MATCH)
5138 /* proper use of this character is caught by end_trigger:
5139 * if we see {, we call parse_group(..., end_trigger='}')
5140 * and it will match } earlier (not here). */
5141 syntax_error_unexpected_ch(ch);
5142 G.last_exitcode = 2;
5146 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5151 G.last_exitcode = 1;
5154 struct parse_context *pctx;
5155 IF_HAS_KEYWORDS(struct parse_context *p2;)
5157 /* Clean up allocated tree.
5158 * Sample for finding leaks on syntax error recovery path.
5159 * Run it from interactive shell, watch pmap `pidof hush`.
5160 * while if false; then false; fi; do break; fi
5161 * Samples to catch leaks at execution:
5162 * while if (true | { true;}); then echo ok; fi; do break; done
5163 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5167 /* Update pipe/command counts,
5168 * otherwise freeing may miss some */
5169 done_pipe(pctx, PIPE_SEQ);
5170 debug_printf_clean("freeing list %p from ctx %p\n",
5171 pctx->list_head, pctx);
5172 debug_print_tree(pctx->list_head, 0);
5173 free_pipe_list(pctx->list_head);
5174 debug_printf_clean("freed list %p\n", pctx->list_head);
5176 o_free_unsafe(&pctx->as_string);
5178 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5182 IF_HAS_KEYWORDS(pctx = p2;)
5183 } while (HAS_KEYWORDS && pctx);
5196 /*** Execution routines ***/
5198 /* Expansion can recurse, need forward decls: */
5199 #if !ENABLE_HUSH_BASH_COMPAT
5200 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5201 #define expand_string_to_string(str, do_unbackslash) \
5202 expand_string_to_string(str)
5204 static char *expand_string_to_string(const char *str, int do_unbackslash);
5205 #if ENABLE_HUSH_TICK
5206 static int process_command_subs(o_string *dest, const char *s);
5209 /* expand_strvec_to_strvec() takes a list of strings, expands
5210 * all variable references within and returns a pointer to
5211 * a list of expanded strings, possibly with larger number
5212 * of strings. (Think VAR="a b"; echo $VAR).
5213 * This new list is allocated as a single malloc block.
5214 * NULL-terminated list of char* pointers is at the beginning of it,
5215 * followed by strings themselves.
5216 * Caller can deallocate entire list by single free(list). */
5218 /* A horde of its helpers come first: */
5220 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5222 while (--len >= 0) {
5225 #if ENABLE_HUSH_BRACE_EXPANSION
5226 if (c == '{' || c == '}') {
5227 /* { -> \{, } -> \} */
5229 /* And now we want to add { or } and continue:
5232 * luckily, just falling throught achieves this.
5238 /* \z -> \\\z; \<eol> -> \\<eol> */
5243 o_addchr(o, *str++);
5249 /* Store given string, finalizing the word and starting new one whenever
5250 * we encounter IFS char(s). This is used for expanding variable values.
5251 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5252 * Return in *ended_with_ifs:
5253 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5255 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5257 int last_is_ifs = 0;
5262 if (!*str) /* EOL - do not finalize word */
5264 word_len = strcspn(str, G.ifs);
5266 /* We have WORD_LEN leading non-IFS chars */
5267 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5268 o_addblock(output, str, word_len);
5270 /* Protect backslashes against globbing up :)
5271 * Example: "v='\*'; echo b$v" prints "b\*"
5272 * (and does not try to glob on "*")
5274 o_addblock_duplicate_backslash(output, str, word_len);
5275 /*/ Why can't we do it easier? */
5276 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5277 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5281 if (!*str) /* EOL - do not finalize word */
5285 /* We know str here points to at least one IFS char */
5287 str += strspn(str, G.ifs); /* skip IFS chars */
5288 if (!*str) /* EOL - do not finalize word */
5291 /* Start new word... but not always! */
5292 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5293 if (output->has_quoted_part
5294 /* Case "v=' a'; echo $v":
5295 * here nothing precedes the space in $v expansion,
5296 * therefore we should not finish the word
5297 * (IOW: if there *is* word to finalize, only then do it):
5299 || (n > 0 && output->data[output->length - 1])
5301 o_addchr(output, '\0');
5302 debug_print_list("expand_on_ifs", output, n);
5303 n = o_save_ptr(output, n);
5308 *ended_with_ifs = last_is_ifs;
5309 debug_print_list("expand_on_ifs[1]", output, n);
5313 /* Helper to expand $((...)) and heredoc body. These act as if
5314 * they are in double quotes, with the exception that they are not :).
5315 * Just the rules are similar: "expand only $var and `cmd`"
5317 * Returns malloced string.
5318 * As an optimization, we return NULL if expansion is not needed.
5320 #if !ENABLE_HUSH_BASH_COMPAT
5321 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5322 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5323 encode_then_expand_string(str)
5325 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5328 struct in_str input;
5329 o_string dest = NULL_O_STRING;
5331 if (!strchr(str, '$')
5332 && !strchr(str, '\\')
5333 #if ENABLE_HUSH_TICK
5334 && !strchr(str, '`')
5340 /* We need to expand. Example:
5341 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5343 setup_string_in_str(&input, str);
5344 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5345 //TODO: error check (encode_string returns 0 on error)?
5346 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5347 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5348 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5349 o_free_unsafe(&dest);
5353 #if ENABLE_FEATURE_SH_MATH
5354 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5356 arith_state_t math_state;
5360 math_state.lookupvar = get_local_var_value;
5361 math_state.setvar = set_local_var_from_halves;
5362 //math_state.endofname = endofname;
5363 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5364 res = arith(&math_state, exp_str ? exp_str : arg);
5367 *errmsg_p = math_state.errmsg;
5368 if (math_state.errmsg)
5369 die_if_script(math_state.errmsg);
5374 #if ENABLE_HUSH_BASH_COMPAT
5375 /* ${var/[/]pattern[/repl]} helpers */
5376 static char *strstr_pattern(char *val, const char *pattern, int *size)
5379 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5380 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5387 /* Optimization: if "*pat" did not match the start of "string",
5388 * we know that "tring", "ring" etc will not match too:
5390 if (pattern[0] == '*')
5395 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5397 char *result = NULL;
5398 unsigned res_len = 0;
5399 unsigned repl_len = strlen(repl);
5403 char *s = strstr_pattern(val, pattern, &size);
5407 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5408 memcpy(result + res_len, val, s - val);
5410 strcpy(result + res_len, repl);
5411 res_len += repl_len;
5412 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5418 if (val[0] && result) {
5419 result = xrealloc(result, res_len + strlen(val) + 1);
5420 strcpy(result + res_len, val);
5421 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5423 debug_printf_varexp("result:'%s'\n", result);
5429 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5431 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5433 const char *val = NULL;
5434 char *to_be_freed = NULL;
5439 char exp_save = exp_save; /* for compiler */
5440 char *exp_saveptr; /* points to expansion operator */
5441 char *exp_word = exp_word; /* for compiler */
5444 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5446 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5448 first_char = arg[0] = arg0 & 0x7f;
5451 if (first_char == '#' /* ${#... */
5452 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5454 /* It must be length operator: ${#var} */
5458 /* Maybe handle parameter expansion */
5459 if (exp_saveptr /* if 2nd char is one of expansion operators */
5460 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5462 /* ${?:0}, ${#[:]%0} etc */
5463 exp_saveptr = var + 1;
5465 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5466 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5468 exp_op = exp_save = *exp_saveptr;
5470 exp_word = exp_saveptr + 1;
5471 if (exp_op == ':') {
5472 exp_op = *exp_word++;
5473 //TODO: try ${var:} and ${var:bogus} in non-bash config
5474 if (ENABLE_HUSH_BASH_COMPAT
5475 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5477 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5482 *exp_saveptr = '\0';
5483 } /* else: it's not an expansion op, but bare ${var} */
5486 /* Look up the variable in question */
5487 if (isdigit(var[0])) {
5488 /* parse_dollar should have vetted var for us */
5489 int n = xatoi_positive(var);
5490 if (n < G.global_argc)
5491 val = G.global_argv[n];
5492 /* else val remains NULL: $N with too big N */
5496 val = utoa(G.root_pid);
5498 case '!': /* bg pid */
5499 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5501 case '?': /* exitcode */
5502 val = utoa(G.last_exitcode);
5504 case '#': /* argc */
5505 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5508 val = get_local_var_value(var);
5512 /* Handle any expansions */
5513 if (exp_op == 'L') {
5514 reinit_unicode_for_hush();
5515 debug_printf_expand("expand: length(%s)=", val);
5516 val = utoa(val ? unicode_strlen(val) : 0);
5517 debug_printf_expand("%s\n", val);
5518 } else if (exp_op) {
5519 if (exp_op == '%' || exp_op == '#') {
5520 /* Standard-mandated substring removal ops:
5521 * ${parameter%word} - remove smallest suffix pattern
5522 * ${parameter%%word} - remove largest suffix pattern
5523 * ${parameter#word} - remove smallest prefix pattern
5524 * ${parameter##word} - remove largest prefix pattern
5526 * Word is expanded to produce a glob pattern.
5527 * Then var's value is matched to it and matching part removed.
5529 if (val && val[0]) {
5533 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5534 if (exp_op == *exp_word) /* ## or %% */
5536 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5538 exp_word = exp_exp_word;
5539 /* HACK ALERT. We depend here on the fact that
5540 * G.global_argv and results of utoa and get_local_var_value
5541 * are actually in writable memory:
5542 * scan_and_match momentarily stores NULs there. */
5544 loc = scan_and_match(t, exp_word, scan_flags);
5545 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5546 // exp_op, t, exp_word, loc);
5548 if (loc) { /* match was found */
5549 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5550 val = loc; /* take right part */
5552 val = to_be_freed = xstrndup(val, loc - val); /* left */
5556 #if ENABLE_HUSH_BASH_COMPAT
5557 else if (exp_op == '/' || exp_op == '\\') {
5558 /* It's ${var/[/]pattern[/repl]} thing.
5559 * Note that in encoded form it has TWO parts:
5560 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5561 * and if // is used, it is encoded as \:
5562 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5564 /* Empty variable always gives nothing: */
5565 // "v=''; echo ${v/*/w}" prints "", not "w"
5566 if (val && val[0]) {
5567 /* pattern uses non-standard expansion.
5568 * repl should be unbackslashed and globbed
5569 * by the usual expansion rules:
5571 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5572 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5573 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5574 * v='a bz'; echo ${v/a*z/\z} prints "z"
5575 * (note that a*z _pattern_ is never globbed!)
5577 char *pattern, *repl, *t;
5578 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5580 pattern = xstrdup(exp_word);
5581 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5582 *p++ = SPECIAL_VAR_SYMBOL;
5584 p = strchr(p, SPECIAL_VAR_SYMBOL);
5586 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5587 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5588 /* HACK ALERT. We depend here on the fact that
5589 * G.global_argv and results of utoa and get_local_var_value
5590 * are actually in writable memory:
5591 * replace_pattern momentarily stores NULs there. */
5593 to_be_freed = replace_pattern(t,
5595 (repl ? repl : exp_word),
5597 if (to_be_freed) /* at least one replace happened */
5604 else if (exp_op == ':') {
5605 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_FEATURE_SH_MATH
5606 /* It's ${var:N[:M]} bashism.
5607 * Note that in encoded form it has TWO parts:
5608 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5613 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5616 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5617 *p++ = SPECIAL_VAR_SYMBOL;
5619 p = strchr(p, SPECIAL_VAR_SYMBOL);
5621 len = expand_and_evaluate_arith(exp_word, &errmsg);
5624 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5625 if (len >= 0) { /* bash compat: len < 0 is illegal */
5626 if (beg < 0) /* bash compat */
5628 debug_printf_varexp("from val:'%s'\n", val);
5629 if (len == 0 || !val || beg >= strlen(val)) {
5633 /* Paranoia. What if user entered 9999999999999
5634 * which fits in arith_t but not int? */
5637 val = to_be_freed = xstrndup(val + beg, len);
5639 debug_printf_varexp("val:'%s'\n", val);
5643 die_if_script("malformed ${%s:...}", var);
5646 } else { /* one of "-=+?" */
5647 /* Standard-mandated substitution ops:
5648 * ${var?word} - indicate error if unset
5649 * If var is unset, word (or a message indicating it is unset
5650 * if word is null) is written to standard error
5651 * and the shell exits with a non-zero exit status.
5652 * Otherwise, the value of var is substituted.
5653 * ${var-word} - use default value
5654 * If var is unset, word is substituted.
5655 * ${var=word} - assign and use default value
5656 * If var is unset, word is assigned to var.
5657 * In all cases, final value of var is substituted.
5658 * ${var+word} - use alternative value
5659 * If var is unset, null is substituted.
5660 * Otherwise, word is substituted.
5662 * Word is subjected to tilde expansion, parameter expansion,
5663 * command substitution, and arithmetic expansion.
5664 * If word is not needed, it is not expanded.
5666 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5667 * but also treat null var as if it is unset.
5669 int use_word = (!val || ((exp_save == ':') && !val[0]));
5671 use_word = !use_word;
5672 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5673 (exp_save == ':') ? "true" : "false", use_word);
5675 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5677 exp_word = to_be_freed;
5678 if (exp_op == '?') {
5679 /* mimic bash message */
5680 die_if_script("%s: %s",
5682 exp_word[0] ? exp_word : "parameter null or not set"
5684 //TODO: how interactive bash aborts expansion mid-command?
5689 if (exp_op == '=') {
5690 /* ${var=[word]} or ${var:=[word]} */
5691 if (isdigit(var[0]) || var[0] == '#') {
5692 /* mimic bash message */
5693 die_if_script("$%s: cannot assign in this way", var);
5696 char *new_var = xasprintf("%s=%s", var, val);
5697 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5701 } /* one of "-=+?" */
5703 *exp_saveptr = exp_save;
5709 *to_be_freed_pp = to_be_freed;
5713 /* Expand all variable references in given string, adding words to list[]
5714 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5715 * to be filled). This routine is extremely tricky: has to deal with
5716 * variables/parameters with whitespace, $* and $@, and constructs like
5717 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5718 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5720 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5721 * expansion of right-hand side of assignment == 1-element expand.
5723 char cant_be_null = 0; /* only bit 0x80 matters */
5724 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5727 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5728 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5729 debug_print_list("expand_vars_to_list", output, n);
5730 n = o_save_ptr(output, n);
5731 debug_print_list("expand_vars_to_list[0]", output, n);
5733 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5735 char *to_be_freed = NULL;
5736 const char *val = NULL;
5737 #if ENABLE_HUSH_TICK
5738 o_string subst_result = NULL_O_STRING;
5740 #if ENABLE_FEATURE_SH_MATH
5741 char arith_buf[sizeof(arith_t)*3 + 2];
5745 o_addchr(output, '\0');
5746 n = o_save_ptr(output, n);
5750 o_addblock(output, arg, p - arg);
5751 debug_print_list("expand_vars_to_list[1]", output, n);
5753 p = strchr(p, SPECIAL_VAR_SYMBOL);
5755 /* Fetch special var name (if it is indeed one of them)
5756 * and quote bit, force the bit on if singleword expansion -
5757 * important for not getting v=$@ expand to many words. */
5758 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5760 /* Is this variable quoted and thus expansion can't be null?
5761 * "$@" is special. Even if quoted, it can still
5762 * expand to nothing (not even an empty string),
5763 * thus it is excluded. */
5764 if ((first_ch & 0x7f) != '@')
5765 cant_be_null |= first_ch;
5767 switch (first_ch & 0x7f) {
5768 /* Highest bit in first_ch indicates that var is double-quoted */
5772 if (!G.global_argv[1])
5775 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5776 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5777 while (G.global_argv[i]) {
5778 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5779 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5780 if (G.global_argv[i++][0] && G.global_argv[i]) {
5781 /* this argv[] is not empty and not last:
5782 * put terminating NUL, start new word */
5783 o_addchr(output, '\0');
5784 debug_print_list("expand_vars_to_list[2]", output, n);
5785 n = o_save_ptr(output, n);
5786 debug_print_list("expand_vars_to_list[3]", output, n);
5790 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5791 * and in this case should treat it like '$*' - see 'else...' below */
5792 if (first_ch == ('@'|0x80) /* quoted $@ */
5793 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5796 o_addQstr(output, G.global_argv[i]);
5797 if (++i >= G.global_argc)
5799 o_addchr(output, '\0');
5800 debug_print_list("expand_vars_to_list[4]", output, n);
5801 n = o_save_ptr(output, n);
5803 } else { /* quoted $* (or v="$@" case): add as one word */
5805 o_addQstr(output, G.global_argv[i]);
5806 if (!G.global_argv[++i])
5809 o_addchr(output, G.ifs[0]);
5811 output->has_quoted_part = 1;
5815 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5816 /* "Empty variable", used to make "" etc to not disappear */
5817 output->has_quoted_part = 1;
5819 cant_be_null = 0x80;
5821 #if ENABLE_HUSH_TICK
5822 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5823 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5825 /* Can't just stuff it into output o_string,
5826 * expanded result may need to be globbed
5827 * and $IFS-splitted */
5828 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5829 G.last_exitcode = process_command_subs(&subst_result, arg);
5830 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5831 val = subst_result.data;
5834 #if ENABLE_FEATURE_SH_MATH
5835 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5838 arg++; /* skip '+' */
5839 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5840 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5841 res = expand_and_evaluate_arith(arg, NULL);
5842 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5843 sprintf(arith_buf, ARITH_FMT, res);
5849 val = expand_one_var(&to_be_freed, arg, &p);
5850 IF_HUSH_TICK(store_val:)
5851 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5852 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5853 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5854 if (val && val[0]) {
5855 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5858 } else { /* quoted $VAR, val will be appended below */
5859 output->has_quoted_part = 1;
5860 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5861 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5864 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5866 if (val && val[0]) {
5867 o_addQstr(output, val);
5871 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5872 * Do the check to avoid writing to a const string. */
5873 if (*p != SPECIAL_VAR_SYMBOL)
5874 *p = SPECIAL_VAR_SYMBOL;
5876 #if ENABLE_HUSH_TICK
5877 o_free(&subst_result);
5880 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5884 o_addchr(output, '\0');
5885 n = o_save_ptr(output, n);
5887 debug_print_list("expand_vars_to_list[a]", output, n);
5888 /* this part is literal, and it was already pre-quoted
5889 * if needed (much earlier), do not use o_addQstr here! */
5890 o_addstr_with_NUL(output, arg);
5891 debug_print_list("expand_vars_to_list[b]", output, n);
5892 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5893 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5896 /* allow to reuse list[n] later without re-growth */
5897 output->has_empty_slot = 1;
5899 o_addchr(output, '\0');
5905 static char **expand_variables(char **argv, unsigned expflags)
5909 o_string output = NULL_O_STRING;
5911 output.o_expflags = expflags;
5915 n = expand_vars_to_list(&output, n, *argv);
5918 debug_print_list("expand_variables", &output, n);
5920 /* output.data (malloced in one block) gets returned in "list" */
5921 list = o_finalize_list(&output, n);
5922 debug_print_strings("expand_variables[1]", list);
5926 static char **expand_strvec_to_strvec(char **argv)
5928 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5931 #if ENABLE_HUSH_BASH_COMPAT
5932 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5934 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5938 /* Used for expansion of right hand of assignments,
5939 * $((...)), heredocs, variable espansion parts.
5941 * NB: should NOT do globbing!
5942 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5944 static char *expand_string_to_string(const char *str, int do_unbackslash)
5946 #if !ENABLE_HUSH_BASH_COMPAT
5947 const int do_unbackslash = 1;
5949 char *argv[2], **list;
5951 debug_printf_expand("string_to_string<='%s'\n", str);
5952 /* This is generally an optimization, but it also
5953 * handles "", which otherwise trips over !list[0] check below.
5954 * (is this ever happens that we actually get str="" here?)
5956 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5957 //TODO: Can use on strings with \ too, just unbackslash() them?
5958 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5959 return xstrdup(str);
5962 argv[0] = (char*)str;
5964 list = expand_variables(argv, do_unbackslash
5965 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5966 : EXP_FLAG_SINGLEWORD
5969 if (!list[0] || list[1])
5970 bb_error_msg_and_die("BUG in varexp2");
5971 /* actually, just move string 2*sizeof(char*) bytes back */
5972 overlapping_strcpy((char*)list, list[0]);
5974 unbackslash((char*)list);
5975 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5979 /* Used for "eval" builtin */
5980 static char* expand_strvec_to_string(char **argv)
5984 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5985 /* Convert all NULs to spaces */
5990 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5991 bb_error_msg_and_die("BUG in varexp3");
5992 /* bash uses ' ' regardless of $IFS contents */
5997 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5998 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6002 static char **expand_assignments(char **argv, int count)
6007 G.expanded_assignments = p = NULL;
6008 /* Expand assignments into one string each */
6009 for (i = 0; i < count; i++) {
6010 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6012 G.expanded_assignments = NULL;
6017 static void switch_off_special_sigs(unsigned mask)
6020 while ((mask >>= 1) != 0) {
6024 #if ENABLE_HUSH_TRAP
6026 if (G_traps[sig] && !G_traps[sig][0])
6027 /* trap is '', has to remain SIG_IGN */
6030 G_traps[sig] = NULL;
6033 /* We are here only if no trap or trap was not '' */
6034 install_sighandler(sig, SIG_DFL);
6040 void re_execute_shell(char ***to_free, const char *s,
6041 char *g_argv0, char **g_argv,
6042 char **builtin_argv) NORETURN;
6044 static void reset_traps_to_defaults(void)
6046 /* This function is always called in a child shell
6047 * after fork (not vfork, NOMMU doesn't use this function).
6049 IF_HUSH_TRAP(unsigned sig;)
6052 /* Child shells are not interactive.
6053 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6054 * Testcase: (while :; do :; done) + ^Z should background.
6055 * Same goes for SIGTERM, SIGHUP, SIGINT.
6057 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6058 if (!G_traps && !mask)
6059 return; /* already no traps and no special sigs */
6061 /* Switch off special sigs */
6062 switch_off_special_sigs(mask);
6063 # if ENABLE_HUSH_JOB
6064 G_fatal_sig_mask = 0;
6066 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6067 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6068 * remain set in G.special_sig_mask */
6070 # if ENABLE_HUSH_TRAP
6074 /* Reset all sigs to default except ones with empty traps */
6075 for (sig = 0; sig < NSIG; sig++) {
6077 continue; /* no trap: nothing to do */
6078 if (!G_traps[sig][0])
6079 continue; /* empty trap: has to remain SIG_IGN */
6080 /* sig has non-empty trap, reset it: */
6082 G_traps[sig] = NULL;
6083 /* There is no signal for trap 0 (EXIT) */
6086 install_sighandler(sig, pick_sighandler(sig));
6093 static void re_execute_shell(char ***to_free, const char *s,
6094 char *g_argv0, char **g_argv,
6095 char **builtin_argv) NORETURN;
6096 static void re_execute_shell(char ***to_free, const char *s,
6097 char *g_argv0, char **g_argv,
6098 char **builtin_argv)
6100 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6101 /* delims + 2 * (number of bytes in printed hex numbers) */
6102 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6103 char *heredoc_argv[4];
6104 struct variable *cur;
6105 # if ENABLE_HUSH_FUNCTIONS
6106 struct function *funcp;
6110 unsigned long long empty_trap_mask;
6112 if (!g_argv0) { /* heredoc */
6113 argv = heredoc_argv;
6114 argv[0] = (char *) G.argv0_for_re_execing;
6115 argv[1] = (char *) "-<";
6116 argv[2] = (char *) s;
6118 pp = &argv[3]; /* used as pointer to empty environment */
6124 if (pp) while (*pp++)
6127 empty_trap_mask = 0;
6130 for (sig = 1; sig < NSIG; sig++) {
6131 if (G_traps[sig] && !G_traps[sig][0])
6132 empty_trap_mask |= 1LL << sig;
6136 sprintf(param_buf, NOMMU_HACK_FMT
6137 , (unsigned) G.root_pid
6138 , (unsigned) G.root_ppid
6139 , (unsigned) G.last_bg_pid
6140 , (unsigned) G.last_exitcode
6143 IF_HUSH_LOOPS(, G.depth_of_loop)
6145 # undef NOMMU_HACK_FMT
6146 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6147 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6150 for (cur = G.top_var; cur; cur = cur->next) {
6151 if (!cur->flg_export || cur->flg_read_only)
6154 # if ENABLE_HUSH_FUNCTIONS
6155 for (funcp = G.top_func; funcp; funcp = funcp->next)
6161 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6162 *pp++ = (char *) G.argv0_for_re_execing;
6164 for (cur = G.top_var; cur; cur = cur->next) {
6165 if (strcmp(cur->varstr, hush_version_str) == 0)
6167 if (cur->flg_read_only) {
6168 *pp++ = (char *) "-R";
6169 *pp++ = cur->varstr;
6170 } else if (!cur->flg_export) {
6171 *pp++ = (char *) "-V";
6172 *pp++ = cur->varstr;
6175 # if ENABLE_HUSH_FUNCTIONS
6176 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6177 *pp++ = (char *) "-F";
6178 *pp++ = funcp->name;
6179 *pp++ = funcp->body_as_string;
6182 /* We can pass activated traps here. Say, -Tnn:trap_string
6184 * However, POSIX says that subshells reset signals with traps
6186 * I tested bash-3.2 and it not only does that with true subshells
6187 * of the form ( list ), but with any forked children shells.
6188 * I set trap "echo W" WINCH; and then tried:
6190 * { echo 1; sleep 20; echo 2; } &
6191 * while true; do echo 1; sleep 20; echo 2; break; done &
6192 * true | { echo 1; sleep 20; echo 2; } | cat
6194 * In all these cases sending SIGWINCH to the child shell
6195 * did not run the trap. If I add trap "echo V" WINCH;
6196 * _inside_ group (just before echo 1), it works.
6198 * I conclude it means we don't need to pass active traps here.
6200 *pp++ = (char *) "-c";
6203 while (*++builtin_argv)
6204 *pp++ = *builtin_argv;
6205 *pp++ = (char *) "";
6210 /* *pp = NULL; - is already there */
6214 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6215 /* Don't propagate SIG_IGN to the child */
6216 if (SPECIAL_JOBSTOP_SIGS != 0)
6217 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6218 execve(bb_busybox_exec_path, argv, pp);
6219 /* Fallback. Useful for init=/bin/hush usage etc */
6220 if (argv[0][0] == '/')
6221 execve(argv[0], argv, pp);
6222 xfunc_error_retval = 127;
6223 bb_error_msg_and_die("can't re-execute the shell");
6225 #endif /* !BB_MMU */
6228 static int run_and_free_list(struct pipe *pi);
6230 /* Executing from string: eval, sh -c '...'
6231 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6232 * end_trigger controls how often we stop parsing
6233 * NUL: parse all, execute, return
6234 * ';': parse till ';' or newline, execute, repeat till EOF
6236 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6238 /* Why we need empty flag?
6239 * An obscure corner case "false; ``; echo $?":
6240 * empty command in `` should still set $? to 0.
6241 * But we can't just set $? to 0 at the start,
6242 * this breaks "false; echo `echo $?`" case.
6246 struct pipe *pipe_list;
6248 #if ENABLE_HUSH_INTERACTIVE
6249 if (end_trigger == ';')
6250 inp->promptmode = 0; /* PS1 */
6252 pipe_list = parse_stream(NULL, inp, end_trigger);
6253 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6254 /* If we are in "big" script
6255 * (not in `cmd` or something similar)...
6257 if (pipe_list == ERR_PTR && end_trigger == ';') {
6258 /* Discard cached input (rest of line) */
6259 int ch = inp->last_char;
6260 while (ch != EOF && ch != '\n') {
6261 //bb_error_msg("Discarded:'%c'", ch);
6266 /* This stream isn't empty */
6270 if (!pipe_list && empty)
6271 G.last_exitcode = 0;
6274 debug_print_tree(pipe_list, 0);
6275 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6276 run_and_free_list(pipe_list);
6278 if (G_flag_return_in_progress == 1)
6283 static void parse_and_run_string(const char *s)
6285 struct in_str input;
6286 setup_string_in_str(&input, s);
6287 parse_and_run_stream(&input, '\0');
6290 static void parse_and_run_file(FILE *f)
6292 struct in_str input;
6293 setup_file_in_str(&input, f);
6294 parse_and_run_stream(&input, ';');
6297 #if ENABLE_HUSH_TICK
6298 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6303 char **to_free = NULL;
6307 pid = BB_MMU ? xfork() : xvfork();
6308 if (pid == 0) { /* child */
6309 disable_restore_tty_pgrp_on_exit();
6310 /* Process substitution is not considered to be usual
6311 * 'command execution'.
6312 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6319 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6320 close(channel[0]); /* NB: close _first_, then move fd! */
6321 xmove_fd(channel[1], 1);
6322 /* Prevent it from trying to handle ctrl-z etc */
6323 IF_HUSH_JOB(G.run_list_level = 1;)
6324 # if ENABLE_HUSH_TRAP
6325 /* Awful hack for `trap` or $(trap).
6327 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6328 * contains an example where "trap" is executed in a subshell:
6330 * save_traps=$(trap)
6332 * eval "$save_traps"
6334 * Standard does not say that "trap" in subshell shall print
6335 * parent shell's traps. It only says that its output
6336 * must have suitable form, but then, in the above example
6337 * (which is not supposed to be normative), it implies that.
6339 * bash (and probably other shell) does implement it
6340 * (traps are reset to defaults, but "trap" still shows them),
6341 * but as a result, "trap" logic is hopelessly messed up:
6344 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6345 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6346 * # true | trap <--- trap is in subshell - no output (ditto)
6347 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6348 * trap -- 'echo Ho' SIGWINCH
6349 * # echo `(trap)` <--- in subshell in subshell - output
6350 * trap -- 'echo Ho' SIGWINCH
6351 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6352 * trap -- 'echo Ho' SIGWINCH
6354 * The rules when to forget and when to not forget traps
6355 * get really complex and nonsensical.
6357 * Our solution: ONLY bare $(trap) or `trap` is special.
6359 s = skip_whitespace(s);
6360 if (is_prefixed_with(s, "trap")
6361 && skip_whitespace(s + 4)[0] == '\0'
6363 static const char *const argv[] = { NULL, NULL };
6364 builtin_trap((char**)argv);
6365 fflush_all(); /* important */
6370 reset_traps_to_defaults();
6371 parse_and_run_string(s);
6372 _exit(G.last_exitcode);
6374 /* We re-execute after vfork on NOMMU. This makes this script safe:
6375 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6376 * huge=`cat BIG` # was blocking here forever
6379 re_execute_shell(&to_free,
6389 # if ENABLE_HUSH_FAST
6391 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6392 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6393 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6395 enable_restore_tty_pgrp_on_exit();
6400 return remember_FILE(xfdopen_for_read(channel[0]));
6403 /* Return code is exit status of the process that is run. */
6404 static int process_command_subs(o_string *dest, const char *s)
6407 struct in_str pipe_str;
6409 int status, ch, eol_cnt;
6411 fp = generate_stream_from_string(s, &pid);
6413 /* Now send results of command back into original context */
6414 setup_file_in_str(&pipe_str, fp);
6416 while ((ch = i_getch(&pipe_str)) != EOF) {
6422 o_addchr(dest, '\n');
6425 o_addQchr(dest, ch);
6428 debug_printf("done reading from `cmd` pipe, closing it\n");
6429 fclose_and_forget(fp);
6430 /* We need to extract exitcode. Test case
6431 * "true; echo `sleep 1; false` $?"
6433 safe_waitpid(pid, &status, 0);
6434 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6435 return WEXITSTATUS(status);
6437 #endif /* ENABLE_HUSH_TICK */
6440 static void setup_heredoc(struct redir_struct *redir)
6442 struct fd_pair pair;
6445 /* the _body_ of heredoc (misleading field name) */
6446 const char *heredoc = redir->rd_filename;
6453 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6454 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6458 len = strlen(heredoc);
6460 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6462 xmove_fd(pair.rd, redir->rd_fd);
6464 /* Try writing without forking. Newer kernels have
6465 * dynamically growing pipes. Must use non-blocking write! */
6468 written = write(pair.wr, heredoc, len);
6479 ndelay_off(pair.wr);
6481 /* Okay, pipe buffer was not big enough */
6482 /* Note: we must not create a stray child (bastard? :)
6483 * for the unsuspecting parent process. Child creates a grandchild
6484 * and exits before parent execs the process which consumes heredoc
6485 * (that exec happens after we return from this function) */
6492 disable_restore_tty_pgrp_on_exit();
6493 pid = BB_MMU ? xfork() : xvfork();
6497 close(redir->rd_fd); /* read side of the pipe */
6499 full_write(pair.wr, heredoc, len); /* may loop or block */
6502 /* Delegate blocking writes to another process */
6503 xmove_fd(pair.wr, STDOUT_FILENO);
6504 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6508 #if ENABLE_HUSH_FAST
6510 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6512 enable_restore_tty_pgrp_on_exit();
6518 wait(NULL); /* wait till child has died */
6521 /* fd: redirect wants this fd to be used (e.g. 3>file).
6522 * Move all conflicting internally used fds,
6523 * and remember them so that we can restore them later.
6525 static int save_fds_on_redirect(int fd, int squirrel[3])
6528 /* Handle redirects of fds 0,1,2 */
6530 /* If we collide with an already moved stdio fd... */
6531 if (fd == squirrel[0]) {
6532 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6535 if (fd == squirrel[1]) {
6536 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6539 if (fd == squirrel[2]) {
6540 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6543 /* If we are about to redirect stdio fd, and did not yet move it... */
6544 if (fd <= 2 && squirrel[fd] < 0) {
6545 /* We avoid taking stdio fds */
6546 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6547 if (squirrel[fd] < 0 && errno != EBADF)
6549 return 0; /* "we did not close fd" */
6553 #if ENABLE_HUSH_INTERACTIVE
6554 if (fd != 0 && fd == G.interactive_fd) {
6555 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6560 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6561 * (1) Redirect in a forked child. No need to save FILEs' fds,
6562 * we aren't going to use them anymore, ok to trash.
6563 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6564 * but how are we doing to use them?
6565 * "fileno(fd) = new_fd" can't be done.
6570 return save_FILEs_on_redirect(fd);
6573 static void restore_redirects(int squirrel[3])
6576 for (i = 0; i <= 2; i++) {
6579 /* We simply die on error */
6584 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6586 restore_redirected_FILEs();
6589 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6590 * and stderr if they are redirected. */
6591 static int setup_redirects(struct command *prog, int squirrel[])
6594 struct redir_struct *redir;
6596 for (redir = prog->redirects; redir; redir = redir->next) {
6597 if (redir->rd_type == REDIRECT_HEREDOC2) {
6598 /* "rd_fd<<HERE" case */
6599 save_fds_on_redirect(redir->rd_fd, squirrel);
6600 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6602 debug_printf_parse("set heredoc '%s'\n",
6603 redir->rd_filename);
6604 setup_heredoc(redir);
6608 if (redir->rd_dup == REDIRFD_TO_FILE) {
6609 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6611 if (redir->rd_filename == NULL) {
6614 * "cmd >" (no filename)
6615 * "cmd > <file" (2nd redirect starts too early)
6617 die_if_script("syntax error: %s", "invalid redirect");
6620 mode = redir_table[redir->rd_type].mode;
6621 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6622 openfd = open_or_warn(p, mode);
6625 /* Error message from open_or_warn can be lost
6626 * if stderr has been redirected, but bash
6627 * and ash both lose it as well
6628 * (though zsh doesn't!)
6633 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6634 openfd = redir->rd_dup;
6637 if (openfd != redir->rd_fd) {
6638 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6639 if (openfd == REDIRFD_CLOSE) {
6640 /* "rd_fd >&-" means "close me" */
6642 /* ^^^ optimization: saving may already
6643 * have closed it. If not... */
6644 close(redir->rd_fd);
6647 xdup2(openfd, redir->rd_fd);
6648 if (redir->rd_dup == REDIRFD_TO_FILE)
6649 /* "rd_fd > FILE" */
6651 /* else: "rd_fd > rd_dup" */
6658 static char *find_in_path(const char *arg)
6661 const char *PATH = get_local_var_value("PATH");
6667 const char *end = strchrnul(PATH, ':');
6668 int sz = end - PATH; /* must be int! */
6672 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6674 /* We have xxx::yyyy in $PATH,
6675 * it means "use current dir" */
6678 if (access(ret, F_OK) == 0)
6691 static const struct built_in_command *find_builtin_helper(const char *name,
6692 const struct built_in_command *x,
6693 const struct built_in_command *end)
6696 if (strcmp(name, x->b_cmd) != 0) {
6700 debug_printf_exec("found builtin '%s'\n", name);
6705 static const struct built_in_command *find_builtin1(const char *name)
6707 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6709 static const struct built_in_command *find_builtin(const char *name)
6711 const struct built_in_command *x = find_builtin1(name);
6714 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6717 #if ENABLE_HUSH_FUNCTIONS
6718 static struct function **find_function_slot(const char *name)
6720 struct function **funcpp = &G.top_func;
6722 if (strcmp(name, (*funcpp)->name) == 0) {
6725 funcpp = &(*funcpp)->next;
6730 static const struct function *find_function(const char *name)
6732 const struct function *funcp = *find_function_slot(name);
6734 debug_printf_exec("found function '%s'\n", name);
6738 /* Note: takes ownership on name ptr */
6739 static struct function *new_function(char *name)
6741 struct function **funcpp = find_function_slot(name);
6742 struct function *funcp = *funcpp;
6744 if (funcp != NULL) {
6745 struct command *cmd = funcp->parent_cmd;
6746 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6748 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6750 /* Note: if !funcp->body, do not free body_as_string!
6751 * This is a special case of "-F name body" function:
6752 * body_as_string was not malloced! */
6754 free_pipe_list(funcp->body);
6756 free(funcp->body_as_string);
6760 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6761 cmd->argv[0] = funcp->name;
6762 cmd->group = funcp->body;
6764 cmd->group_as_string = funcp->body_as_string;
6768 debug_printf_exec("remembering new function '%s'\n", name);
6769 funcp = *funcpp = xzalloc(sizeof(*funcp));
6770 /*funcp->next = NULL;*/
6777 # if ENABLE_HUSH_UNSET
6778 static void unset_func(const char *name)
6780 struct function **funcpp = find_function_slot(name);
6781 struct function *funcp = *funcpp;
6783 if (funcp != NULL) {
6784 debug_printf_exec("freeing function '%s'\n", funcp->name);
6785 *funcpp = funcp->next;
6786 /* funcp is unlinked now, deleting it.
6787 * Note: if !funcp->body, the function was created by
6788 * "-F name body", do not free ->body_as_string
6789 * and ->name as they were not malloced. */
6791 free_pipe_list(funcp->body);
6794 free(funcp->body_as_string);
6803 #define exec_function(to_free, funcp, argv) \
6804 exec_function(funcp, argv)
6806 static void exec_function(char ***to_free,
6807 const struct function *funcp,
6808 char **argv) NORETURN;
6809 static void exec_function(char ***to_free,
6810 const struct function *funcp,
6816 argv[0] = G.global_argv[0];
6817 G.global_argv = argv;
6821 /* On MMU, funcp->body is always non-NULL */
6822 n = run_list(funcp->body);
6826 re_execute_shell(to_free,
6827 funcp->body_as_string,
6834 static int run_function(const struct function *funcp, char **argv)
6840 save_and_replace_G_args(&sv, argv);
6842 /* "we are in function, ok to use return" */
6843 sv_flg = G_flag_return_in_progress;
6844 G_flag_return_in_progress = -1;
6845 # if ENABLE_HUSH_LOCAL
6846 G.func_nest_level++;
6849 /* On MMU, funcp->body is always non-NULL */
6852 /* Function defined by -F */
6853 parse_and_run_string(funcp->body_as_string);
6854 rc = G.last_exitcode;
6858 rc = run_list(funcp->body);
6861 # if ENABLE_HUSH_LOCAL
6863 struct variable *var;
6864 struct variable **var_pp;
6866 var_pp = &G.top_var;
6867 while ((var = *var_pp) != NULL) {
6868 if (var->func_nest_level < G.func_nest_level) {
6869 var_pp = &var->next;
6873 if (var->flg_export)
6874 bb_unsetenv(var->varstr);
6875 /* Remove from global list */
6876 *var_pp = var->next;
6882 G.func_nest_level--;
6885 G_flag_return_in_progress = sv_flg;
6887 restore_G_args(&sv, argv);
6891 #endif /* ENABLE_HUSH_FUNCTIONS */
6895 #define exec_builtin(to_free, x, argv) \
6896 exec_builtin(x, argv)
6898 #define exec_builtin(to_free, x, argv) \
6899 exec_builtin(to_free, argv)
6901 static void exec_builtin(char ***to_free,
6902 const struct built_in_command *x,
6903 char **argv) NORETURN;
6904 static void exec_builtin(char ***to_free,
6905 const struct built_in_command *x,
6911 rcode = x->b_function(argv);
6916 /* On NOMMU, we must never block!
6917 * Example: { sleep 99 | read line; } & echo Ok
6919 re_execute_shell(to_free,
6928 static void execvp_or_die(char **argv) NORETURN;
6929 static void execvp_or_die(char **argv)
6932 debug_printf_exec("execing '%s'\n", argv[0]);
6933 /* Don't propagate SIG_IGN to the child */
6934 if (SPECIAL_JOBSTOP_SIGS != 0)
6935 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6936 execvp(argv[0], argv);
6938 if (errno == EACCES) e = 126;
6939 if (errno == ENOENT) e = 127;
6940 bb_perror_msg("can't execute '%s'", argv[0]);
6944 #if ENABLE_HUSH_MODE_X
6945 static void dump_cmd_in_x_mode(char **argv)
6947 if (G_x_mode && argv) {
6948 /* We want to output the line in one write op */
6956 len += strlen(argv[n++]) + 1;
6962 p += sprintf(p, " %s", argv[n++]);
6970 # define dump_cmd_in_x_mode(argv) ((void)0)
6974 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6975 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6976 #define pseudo_exec(nommu_save, command, argv_expanded) \
6977 pseudo_exec(command, argv_expanded)
6980 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6982 * Don't exit() here. If you don't exec, use _exit instead.
6983 * The at_exit handlers apparently confuse the calling process,
6984 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6986 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6987 char **argv, int assignment_cnt,
6988 char **argv_expanded) NORETURN;
6989 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6990 char **argv, int assignment_cnt,
6991 char **argv_expanded)
6995 new_env = expand_assignments(argv, assignment_cnt);
6996 dump_cmd_in_x_mode(new_env);
6998 if (!argv[assignment_cnt]) {
6999 /* Case when we are here: ... | var=val | ...
7000 * (note that we do not exit early, i.e., do not optimize out
7001 * expand_assignments(): think about ... | var=`sleep 1` | ...
7003 free_strings(new_env);
7004 _exit(EXIT_SUCCESS);
7008 set_vars_and_save_old(new_env);
7009 free(new_env); /* optional */
7010 /* we can also destroy set_vars_and_save_old's return value,
7013 nommu_save->new_env = new_env;
7014 nommu_save->old_vars = set_vars_and_save_old(new_env);
7017 if (argv_expanded) {
7018 argv = argv_expanded;
7020 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7022 nommu_save->argv = argv;
7025 dump_cmd_in_x_mode(argv);
7027 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7028 if (strchr(argv[0], '/') != NULL)
7032 /* Check if the command matches any of the builtins.
7033 * Depending on context, this might be redundant. But it's
7034 * easier to waste a few CPU cycles than it is to figure out
7035 * if this is one of those cases.
7038 /* On NOMMU, it is more expensive to re-execute shell
7039 * just in order to run echo or test builtin.
7040 * It's better to skip it here and run corresponding
7041 * non-builtin later. */
7042 const struct built_in_command *x;
7043 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7045 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7048 #if ENABLE_HUSH_FUNCTIONS
7049 /* Check if the command matches any functions */
7051 const struct function *funcp = find_function(argv[0]);
7053 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7058 #if ENABLE_FEATURE_SH_STANDALONE
7059 /* Check if the command matches any busybox applets */
7061 int a = find_applet_by_name(argv[0]);
7063 # if BB_MMU /* see above why on NOMMU it is not allowed */
7064 if (APPLET_IS_NOEXEC(a)) {
7065 /* Do not leak open fds from opened script files etc */
7066 close_all_FILE_list();
7067 debug_printf_exec("running applet '%s'\n", argv[0]);
7068 run_applet_no_and_exit(a, argv);
7071 /* Re-exec ourselves */
7072 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7073 /* Don't propagate SIG_IGN to the child */
7074 if (SPECIAL_JOBSTOP_SIGS != 0)
7075 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7076 execv(bb_busybox_exec_path, argv);
7077 /* If they called chroot or otherwise made the binary no longer
7078 * executable, fall through */
7083 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7086 execvp_or_die(argv);
7089 /* Called after [v]fork() in run_pipe
7091 static void pseudo_exec(nommu_save_t *nommu_save,
7092 struct command *command,
7093 char **argv_expanded) NORETURN;
7094 static void pseudo_exec(nommu_save_t *nommu_save,
7095 struct command *command,
7096 char **argv_expanded)
7098 if (command->argv) {
7099 pseudo_exec_argv(nommu_save, command->argv,
7100 command->assignment_cnt, argv_expanded);
7103 if (command->group) {
7104 /* Cases when we are here:
7107 * ... | ( list ) | ...
7108 * ... | { list } | ...
7112 debug_printf_exec("pseudo_exec: run_list\n");
7113 reset_traps_to_defaults();
7114 rcode = run_list(command->group);
7115 /* OK to leak memory by not calling free_pipe_list,
7116 * since this process is about to exit */
7119 re_execute_shell(&nommu_save->argv_from_re_execing,
7120 command->group_as_string,
7127 /* Case when we are here: ... | >file */
7128 debug_printf_exec("pseudo_exec'ed null command\n");
7129 _exit(EXIT_SUCCESS);
7133 static const char *get_cmdtext(struct pipe *pi)
7139 /* This is subtle. ->cmdtext is created only on first backgrounding.
7140 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7141 * On subsequent bg argv is trashed, but we won't use it */
7145 argv = pi->cmds[0].argv;
7147 pi->cmdtext = xzalloc(1);
7152 len += strlen(*argv) + 1;
7156 argv = pi->cmds[0].argv;
7158 p = stpcpy(p, *argv);
7165 static void insert_bg_job(struct pipe *pi)
7167 struct pipe *job, **jobp;
7170 /* Linear search for the ID of the job to use */
7172 for (job = G.job_list; job; job = job->next)
7173 if (job->jobid >= pi->jobid)
7174 pi->jobid = job->jobid + 1;
7176 /* Add job to the list of running jobs */
7178 while ((job = *jobp) != NULL)
7180 job = *jobp = xmalloc(sizeof(*job));
7182 *job = *pi; /* physical copy */
7184 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7185 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7186 for (i = 0; i < pi->num_cmds; i++) {
7187 job->cmds[i].pid = pi->cmds[i].pid;
7188 /* all other fields are not used and stay zero */
7190 job->cmdtext = xstrdup(get_cmdtext(pi));
7192 if (G_interactive_fd)
7193 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7194 G.last_jobid = job->jobid;
7197 static void remove_bg_job(struct pipe *pi)
7199 struct pipe *prev_pipe;
7201 if (pi == G.job_list) {
7202 G.job_list = pi->next;
7204 prev_pipe = G.job_list;
7205 while (prev_pipe->next != pi)
7206 prev_pipe = prev_pipe->next;
7207 prev_pipe->next = pi->next;
7210 G.last_jobid = G.job_list->jobid;
7215 /* Remove a backgrounded job */
7216 static void delete_finished_bg_job(struct pipe *pi)
7223 static int job_exited_or_stopped(struct pipe *pi)
7227 if (pi->alive_cmds != pi->stopped_cmds)
7230 /* All processes in fg pipe have exited or stopped */
7234 rcode = pi->cmds[i].cmd_exitcode;
7235 /* usually last process gives overall exitstatus,
7236 * but with "set -o pipefail", last *failed* process does */
7237 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7240 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7244 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7251 dead = WIFEXITED(status) || WIFSIGNALED(status);
7254 if (WIFSTOPPED(status))
7255 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7256 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7257 if (WIFSIGNALED(status))
7258 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7259 childpid, WTERMSIG(status), WEXITSTATUS(status));
7260 if (WIFEXITED(status))
7261 debug_printf_jobs("pid %d exited, exitcode %d\n",
7262 childpid, WEXITSTATUS(status));
7264 /* Were we asked to wait for a fg pipe? */
7266 i = fg_pipe->num_cmds;
7271 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7272 if (fg_pipe->cmds[i].pid != childpid)
7276 fg_pipe->cmds[i].pid = 0;
7277 fg_pipe->alive_cmds--;
7278 ex = WEXITSTATUS(status);
7279 /* bash prints killer signal's name for *last*
7280 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7281 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7283 if (WIFSIGNALED(status)) {
7284 int sig = WTERMSIG(status);
7285 if (i == fg_pipe->num_cmds-1)
7286 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7287 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7288 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7289 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7290 * Maybe we need to use sig | 128? */
7293 fg_pipe->cmds[i].cmd_exitcode = ex;
7295 fg_pipe->stopped_cmds++;
7297 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7298 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7299 rcode = job_exited_or_stopped(fg_pipe);
7301 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7302 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7303 * and "killall -STOP cat" */
7304 if (G_interactive_fd) {
7306 if (fg_pipe->alive_cmds != 0)
7307 insert_bg_job(fg_pipe);
7311 if (fg_pipe->alive_cmds == 0)
7314 /* There are still running processes in the fg_pipe */
7317 /* It wasnt in fg_pipe, look for process in bg pipes */
7321 /* We were asked to wait for bg or orphaned children */
7322 /* No need to remember exitcode in this case */
7323 for (pi = G.job_list; pi; pi = pi->next) {
7324 for (i = 0; i < pi->num_cmds; i++) {
7325 if (pi->cmds[i].pid == childpid)
7326 goto found_pi_and_prognum;
7329 /* Happens when shell is used as init process (init=/bin/sh) */
7330 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7331 return -1; /* this wasn't a process from fg_pipe */
7333 found_pi_and_prognum:
7336 pi->cmds[i].pid = 0;
7337 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7338 if (WIFSIGNALED(status))
7339 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7341 if (!pi->alive_cmds) {
7342 if (G_interactive_fd)
7343 printf(JOB_STATUS_FORMAT, pi->jobid,
7344 "Done", pi->cmdtext);
7345 delete_finished_bg_job(pi);
7352 return -1; /* this wasn't a process from fg_pipe */
7355 /* Check to see if any processes have exited -- if they have,
7356 * figure out why and see if a job has completed.
7358 * If non-NULL fg_pipe: wait for its completion or stop.
7359 * Return its exitcode or zero if stopped.
7361 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7362 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7363 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7364 * or 0 if no children changed status.
7366 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7367 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7368 * or 0 if no children changed status.
7370 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7376 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7378 attributes = WUNTRACED;
7379 if (fg_pipe == NULL)
7380 attributes |= WNOHANG;
7383 #if ENABLE_HUSH_FAST
7384 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7385 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7386 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7387 /* There was neither fork nor SIGCHLD since last waitpid */
7388 /* Avoid doing waitpid syscall if possible */
7389 if (!G.we_have_children) {
7393 if (fg_pipe == NULL) { /* is WNOHANG set? */
7394 /* We have children, but they did not exit
7395 * or stop yet (we saw no SIGCHLD) */
7398 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7402 /* Do we do this right?
7403 * bash-3.00# sleep 20 | false
7405 * [3]+ Stopped sleep 20 | false
7406 * bash-3.00# echo $?
7407 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7408 * [hush 1.14.0: yes we do it right]
7412 #if ENABLE_HUSH_FAST
7414 i = G.count_SIGCHLD;
7416 childpid = waitpid(-1, &status, attributes);
7417 if (childpid <= 0) {
7418 if (childpid && errno != ECHILD)
7419 bb_perror_msg("waitpid");
7420 #if ENABLE_HUSH_FAST
7421 else { /* Until next SIGCHLD, waitpid's are useless */
7422 G.we_have_children = (childpid == 0);
7423 G.handled_SIGCHLD = i;
7424 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7427 /* ECHILD (no children), or 0 (no change in children status) */
7431 rcode = process_wait_result(fg_pipe, childpid, status);
7433 /* fg_pipe exited or stopped */
7436 if (childpid == waitfor_pid) {
7437 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7438 rcode = WEXITSTATUS(status);
7439 if (WIFSIGNALED(status))
7440 rcode = 128 + WTERMSIG(status);
7441 if (WIFSTOPPED(status))
7442 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7443 rcode = 128 + WSTOPSIG(status);
7445 break; /* "wait PID" called us, give it exitcode+1 */
7447 /* This wasn't one of our processes, or */
7448 /* fg_pipe still has running processes, do waitpid again */
7449 } /* while (waitpid succeeds)... */
7455 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7458 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7459 if (G_saved_tty_pgrp) {
7460 /* Job finished, move the shell to the foreground */
7461 p = getpgrp(); /* our process group id */
7462 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7463 tcsetpgrp(G_interactive_fd, p);
7469 /* Start all the jobs, but don't wait for anything to finish.
7472 * Return code is normally -1, when the caller has to wait for children
7473 * to finish to determine the exit status of the pipe. If the pipe
7474 * is a simple builtin command, however, the action is done by the
7475 * time run_pipe returns, and the exit code is provided as the
7478 * Returns -1 only if started some children. IOW: we have to
7479 * mask out retvals of builtins etc with 0xff!
7481 * The only case when we do not need to [v]fork is when the pipe
7482 * is single, non-backgrounded, non-subshell command. Examples:
7483 * cmd ; ... { list } ; ...
7484 * cmd && ... { list } && ...
7485 * cmd || ... { list } || ...
7486 * If it is, then we can run cmd as a builtin, NOFORK,
7487 * or (if SH_STANDALONE) an applet, and we can run the { list }
7488 * with run_list. If it isn't one of these, we fork and exec cmd.
7490 * Cases when we must fork:
7491 * non-single: cmd | cmd
7492 * backgrounded: cmd & { list } &
7493 * subshell: ( list ) [&]
7495 #if !ENABLE_HUSH_MODE_X
7496 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7497 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7499 static int redirect_and_varexp_helper(char ***new_env_p,
7500 struct variable **old_vars_p,
7501 struct command *command,
7503 char **argv_expanded)
7505 /* setup_redirects acts on file descriptors, not FILEs.
7506 * This is perfect for work that comes after exec().
7507 * Is it really safe for inline use? Experimentally,
7508 * things seem to work. */
7509 int rcode = setup_redirects(command, squirrel);
7511 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7512 *new_env_p = new_env;
7513 dump_cmd_in_x_mode(new_env);
7514 dump_cmd_in_x_mode(argv_expanded);
7516 *old_vars_p = set_vars_and_save_old(new_env);
7520 static NOINLINE int run_pipe(struct pipe *pi)
7522 static const char *const null_ptr = NULL;
7526 struct command *command;
7527 char **argv_expanded;
7529 /* it is not always needed, but we aim to smaller code */
7530 int squirrel[] = { -1, -1, -1 };
7533 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7536 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7537 * Result should be 3 lines: q w e, qwe, q w e
7539 G.ifs = get_local_var_value("IFS");
7543 IF_HUSH_JOB(pi->pgrp = -1;)
7544 pi->stopped_cmds = 0;
7545 command = &pi->cmds[0];
7546 argv_expanded = NULL;
7548 if (pi->num_cmds != 1
7549 || pi->followup == PIPE_BG
7550 || command->cmd_type == CMD_SUBSHELL
7557 debug_printf_exec(": group:%p argv:'%s'\n",
7558 command->group, command->argv ? command->argv[0] : "NONE");
7560 if (command->group) {
7561 #if ENABLE_HUSH_FUNCTIONS
7562 if (command->cmd_type == CMD_FUNCDEF) {
7563 /* "executing" func () { list } */
7564 struct function *funcp;
7566 funcp = new_function(command->argv[0]);
7567 /* funcp->name is already set to argv[0] */
7568 funcp->body = command->group;
7570 funcp->body_as_string = command->group_as_string;
7571 command->group_as_string = NULL;
7573 command->group = NULL;
7574 command->argv[0] = NULL;
7575 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7576 funcp->parent_cmd = command;
7577 command->child_func = funcp;
7579 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7581 return EXIT_SUCCESS;
7585 debug_printf("non-subshell group\n");
7586 rcode = 1; /* exitcode if redir failed */
7587 if (setup_redirects(command, squirrel) == 0) {
7588 debug_printf_exec(": run_list\n");
7589 rcode = run_list(command->group) & 0xff;
7591 restore_redirects(squirrel);
7592 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7594 debug_printf_exec("run_pipe: return %d\n", rcode);
7598 argv = command->argv ? command->argv : (char **) &null_ptr;
7600 const struct built_in_command *x;
7601 #if ENABLE_HUSH_FUNCTIONS
7602 const struct function *funcp;
7606 char **new_env = NULL;
7607 struct variable *old_vars = NULL;
7609 if (argv[command->assignment_cnt] == NULL) {
7610 /* Assignments, but no command */
7611 /* Ensure redirects take effect (that is, create files).
7612 * Try "a=t >file" */
7613 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7614 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7615 /* Set shell variables */
7619 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7620 /* Do we need to flag set_local_var() errors?
7621 * "assignment to readonly var" and "putenv error"
7626 /* Redirect error sets $? to 1. Otherwise,
7627 * if evaluating assignment value set $?, retain it.
7628 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7630 rcode = G.last_exitcode;
7631 /* Exit, _skipping_ variable restoring code: */
7632 goto clean_up_and_ret0;
7634 #else /* Older, bigger, but more correct code */
7636 rcode = setup_redirects(command, squirrel);
7637 restore_redirects(squirrel);
7638 /* Set shell variables */
7640 bb_putchar_stderr('+');
7642 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7644 fprintf(stderr, " %s", p);
7645 debug_printf_exec("set shell var:'%s'->'%s'\n",
7647 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7648 /* Do we need to flag set_local_var() errors?
7649 * "assignment to readonly var" and "putenv error"
7654 bb_putchar_stderr('\n');
7655 /* Redirect error sets $? to 1. Otherwise,
7656 * if evaluating assignment value set $?, retain it.
7657 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7659 rcode = G.last_exitcode;
7660 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7662 debug_printf_exec("run_pipe: return %d\n", rcode);
7667 /* Expand the rest into (possibly) many strings each */
7668 #if ENABLE_HUSH_BASH_COMPAT
7669 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7670 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7674 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7677 /* if someone gives us an empty string: `cmd with empty output` */
7678 if (!argv_expanded[0]) {
7679 free(argv_expanded);
7681 return G.last_exitcode;
7684 x = find_builtin(argv_expanded[0]);
7685 #if ENABLE_HUSH_FUNCTIONS
7688 funcp = find_function(argv_expanded[0]);
7692 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7693 debug_printf("exec with redirects only\n");
7694 rcode = setup_redirects(command, NULL);
7695 /* rcode=1 can be if redir file can't be opened */
7696 goto clean_up_and_ret1;
7699 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7702 debug_printf_exec(": builtin '%s' '%s'...\n",
7703 x->b_cmd, argv_expanded[1]);
7705 rcode = x->b_function(argv_expanded) & 0xff;
7708 #if ENABLE_HUSH_FUNCTIONS
7710 # if ENABLE_HUSH_LOCAL
7711 struct variable **sv;
7712 sv = G.shadowed_vars_pp;
7713 G.shadowed_vars_pp = &old_vars;
7715 debug_printf_exec(": function '%s' '%s'...\n",
7716 funcp->name, argv_expanded[1]);
7717 rcode = run_function(funcp, argv_expanded) & 0xff;
7718 # if ENABLE_HUSH_LOCAL
7719 G.shadowed_vars_pp = sv;
7725 unset_vars(new_env);
7727 /* clean_up_and_ret0: */
7728 restore_redirects(squirrel);
7730 free(argv_expanded);
7731 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7733 debug_printf_exec("run_pipe return %d\n", rcode);
7737 if (ENABLE_FEATURE_SH_NOFORK) {
7738 int n = find_applet_by_name(argv_expanded[0]);
7739 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7740 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7742 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7743 argv_expanded[0], argv_expanded[1]);
7744 rcode = run_nofork_applet(n, argv_expanded);
7746 goto clean_up_and_ret;
7749 /* It is neither builtin nor applet. We must fork. */
7753 /* NB: argv_expanded may already be created, and that
7754 * might include `cmd` runs! Do not rerun it! We *must*
7755 * use argv_expanded if it's non-NULL */
7757 /* Going to fork a child per each pipe member */
7762 while (cmd_no < pi->num_cmds) {
7763 struct fd_pair pipefds;
7765 volatile nommu_save_t nommu_save;
7766 nommu_save.new_env = NULL;
7767 nommu_save.old_vars = NULL;
7768 nommu_save.argv = NULL;
7769 nommu_save.argv_from_re_execing = NULL;
7771 command = &pi->cmds[cmd_no];
7773 if (command->argv) {
7774 debug_printf_exec(": pipe member '%s' '%s'...\n",
7775 command->argv[0], command->argv[1]);
7777 debug_printf_exec(": pipe member with no argv\n");
7780 /* pipes are inserted between pairs of commands */
7783 if (cmd_no < pi->num_cmds)
7784 xpiped_pair(pipefds);
7786 command->pid = BB_MMU ? fork() : vfork();
7787 if (!command->pid) { /* child */
7789 disable_restore_tty_pgrp_on_exit();
7790 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7792 /* Every child adds itself to new process group
7793 * with pgid == pid_of_first_child_in_pipe */
7794 if (G.run_list_level == 1 && G_interactive_fd) {
7797 if (pgrp < 0) /* true for 1st process only */
7799 if (setpgid(0, pgrp) == 0
7800 && pi->followup != PIPE_BG
7801 && G_saved_tty_pgrp /* we have ctty */
7803 /* We do it in *every* child, not just first,
7805 tcsetpgrp(G_interactive_fd, pgrp);
7809 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7810 /* 1st cmd in backgrounded pipe
7811 * should have its stdin /dev/null'ed */
7813 if (open(bb_dev_null, O_RDONLY))
7814 xopen("/", O_RDONLY);
7816 xmove_fd(next_infd, 0);
7818 xmove_fd(pipefds.wr, 1);
7821 /* Like bash, explicit redirects override pipes,
7822 * and the pipe fd (fd#1) is available for dup'ing:
7823 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7824 * of cmd1 goes into pipe.
7826 if (setup_redirects(command, NULL)) {
7827 /* Happens when redir file can't be opened:
7828 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7830 * hush: can't open '/qwe/rty': No such file or directory
7832 * (echo BAR is not executed, it hits _exit(1) below)
7837 /* Stores to nommu_save list of env vars putenv'ed
7838 * (NOMMU, on MMU we don't need that) */
7839 /* cast away volatility... */
7840 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7841 /* pseudo_exec() does not return */
7844 /* parent or error */
7845 #if ENABLE_HUSH_FAST
7847 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7849 enable_restore_tty_pgrp_on_exit();
7851 /* Clean up after vforked child */
7852 free(nommu_save.argv);
7853 free(nommu_save.argv_from_re_execing);
7854 unset_vars(nommu_save.new_env);
7855 add_vars(nommu_save.old_vars);
7857 free(argv_expanded);
7858 argv_expanded = NULL;
7859 if (command->pid < 0) { /* [v]fork failed */
7860 /* Clearly indicate, was it fork or vfork */
7861 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7865 /* Second and next children need to know pid of first one */
7867 pi->pgrp = command->pid;
7873 if (cmd_no < pi->num_cmds)
7875 /* Pass read (output) pipe end to next iteration */
7876 next_infd = pipefds.rd;
7879 if (!pi->alive_cmds) {
7881 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7886 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7890 /* NB: called by pseudo_exec, and therefore must not modify any
7891 * global data until exec/_exit (we can be a child after vfork!) */
7892 static int run_list(struct pipe *pi)
7894 #if ENABLE_HUSH_CASE
7895 char *case_word = NULL;
7897 #if ENABLE_HUSH_LOOPS
7898 struct pipe *loop_top = NULL;
7899 char **for_lcur = NULL;
7900 char **for_list = NULL;
7902 smallint last_followup;
7904 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7905 smalluint cond_code = 0;
7907 enum { cond_code = 0 };
7910 smallint rword; /* RES_foo */
7911 smallint last_rword; /* ditto */
7914 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7917 #if ENABLE_HUSH_LOOPS
7918 /* Check syntax for "for" */
7921 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7922 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7924 /* current word is FOR or IN (BOLD in comments below) */
7925 if (cpipe->next == NULL) {
7926 syntax_error("malformed for");
7928 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7931 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7932 if (cpipe->next->res_word == RES_DO)
7934 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7935 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7936 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7938 syntax_error("malformed for");
7940 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7947 /* Past this point, all code paths should jump to ret: label
7948 * in order to return, no direct "return" statements please.
7949 * This helps to ensure that no memory is leaked. */
7957 last_rword = RES_XXXX;
7959 last_followup = PIPE_SEQ;
7960 rcode = G.last_exitcode;
7962 /* Go through list of pipes, (maybe) executing them. */
7963 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7968 if (G_flag_return_in_progress == 1)
7971 IF_HAS_KEYWORDS(rword = pi->res_word;)
7972 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7973 rword, cond_code, last_rword);
7974 #if ENABLE_HUSH_LOOPS
7975 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7976 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7978 /* start of a loop: remember where loop starts */
7983 /* Still in the same "if...", "then..." or "do..." branch? */
7984 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7985 if ((rcode == 0 && last_followup == PIPE_OR)
7986 || (rcode != 0 && last_followup == PIPE_AND)
7988 /* It is "<true> || CMD" or "<false> && CMD"
7989 * and we should not execute CMD */
7990 debug_printf_exec("skipped cmd because of || or &&\n");
7991 last_followup = pi->followup;
7992 goto dont_check_jobs_but_continue;
7995 last_followup = pi->followup;
7996 IF_HAS_KEYWORDS(last_rword = rword;)
7999 if (rword == RES_THEN) {
8000 /* if false; then ... fi has exitcode 0! */
8001 G.last_exitcode = rcode = EXIT_SUCCESS;
8002 /* "if <false> THEN cmd": skip cmd */
8006 if (rword == RES_ELSE || rword == RES_ELIF) {
8007 /* "if <true> then ... ELSE/ELIF cmd":
8008 * skip cmd and all following ones */
8013 #if ENABLE_HUSH_LOOPS
8014 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8016 /* first loop through for */
8018 static const char encoded_dollar_at[] ALIGN1 = {
8019 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8020 }; /* encoded representation of "$@" */
8021 static const char *const encoded_dollar_at_argv[] = {
8022 encoded_dollar_at, NULL
8023 }; /* argv list with one element: "$@" */
8026 vals = (char**)encoded_dollar_at_argv;
8027 if (pi->next->res_word == RES_IN) {
8028 /* if no variable values after "in" we skip "for" */
8029 if (!pi->next->cmds[0].argv) {
8030 G.last_exitcode = rcode = EXIT_SUCCESS;
8031 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8034 vals = pi->next->cmds[0].argv;
8035 } /* else: "for var; do..." -> assume "$@" list */
8036 /* create list of variable values */
8037 debug_print_strings("for_list made from", vals);
8038 for_list = expand_strvec_to_strvec(vals);
8039 for_lcur = for_list;
8040 debug_print_strings("for_list", for_list);
8043 /* "for" loop is over, clean up */
8049 /* Insert next value from for_lcur */
8050 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8051 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8054 if (rword == RES_IN) {
8055 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8057 if (rword == RES_DONE) {
8058 continue; /* "done" has no cmds too */
8061 #if ENABLE_HUSH_CASE
8062 if (rword == RES_CASE) {
8063 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8064 case_word = expand_strvec_to_string(pi->cmds->argv);
8067 if (rword == RES_MATCH) {
8070 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8071 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8073 /* all prev words didn't match, does this one match? */
8074 argv = pi->cmds->argv;
8076 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8077 /* TODO: which FNM_xxx flags to use? */
8078 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8080 if (cond_code == 0) { /* match! we will execute this branch */
8082 case_word = NULL; /* make future "word)" stop */
8089 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8090 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8092 continue; /* not matched yet, skip this pipe */
8094 if (rword == RES_ESAC) {
8095 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8097 /* "case" did not match anything: still set $? (to 0) */
8098 G.last_exitcode = rcode = EXIT_SUCCESS;
8102 /* Just pressing <enter> in shell should check for jobs.
8103 * OTOH, in non-interactive shell this is useless
8104 * and only leads to extra job checks */
8105 if (pi->num_cmds == 0) {
8106 if (G_interactive_fd)
8107 goto check_jobs_and_continue;
8111 /* After analyzing all keywords and conditions, we decided
8112 * to execute this pipe. NB: have to do checkjobs(NULL)
8113 * after run_pipe to collect any background children,
8114 * even if list execution is to be stopped. */
8115 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8116 #if ENABLE_HUSH_LOOPS
8117 G.flag_break_continue = 0;
8119 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8121 /* We ran a builtin, function, or group.
8122 * rcode is already known
8123 * and we don't need to wait for anything. */
8124 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8125 G.last_exitcode = rcode;
8126 check_and_run_traps();
8127 #if ENABLE_HUSH_LOOPS
8128 /* Was it "break" or "continue"? */
8129 if (G.flag_break_continue) {
8130 smallint fbc = G.flag_break_continue;
8131 /* We might fall into outer *loop*,
8132 * don't want to break it too */
8134 G.depth_break_continue--;
8135 if (G.depth_break_continue == 0)
8136 G.flag_break_continue = 0;
8137 /* else: e.g. "continue 2" should *break* once, *then* continue */
8138 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8139 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8140 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8143 /* "continue": simulate end of loop */
8148 if (G_flag_return_in_progress == 1) {
8149 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8152 } else if (pi->followup == PIPE_BG) {
8153 /* What does bash do with attempts to background builtins? */
8154 /* even bash 3.2 doesn't do that well with nested bg:
8155 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8156 * I'm NOT treating inner &'s as jobs */
8158 if (G.run_list_level == 1)
8161 /* Last command's pid goes to $! */
8162 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8163 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8164 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8165 rcode = EXIT_SUCCESS;
8169 if (G.run_list_level == 1 && G_interactive_fd) {
8170 /* Waits for completion, then fg's main shell */
8171 rcode = checkjobs_and_fg_shell(pi);
8172 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8176 /* This one just waits for completion */
8177 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8178 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8180 G.last_exitcode = rcode;
8181 check_and_run_traps();
8184 /* Analyze how result affects subsequent commands */
8186 if (rword == RES_IF || rword == RES_ELIF)
8189 check_jobs_and_continue:
8190 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8191 dont_check_jobs_but_continue: ;
8192 #if ENABLE_HUSH_LOOPS
8193 /* Beware of "while false; true; do ..."! */
8195 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8196 /* check for RES_DONE is needed for "while ...; do \n done" case */
8198 if (rword == RES_WHILE) {
8200 /* "while false; do...done" - exitcode 0 */
8201 G.last_exitcode = rcode = EXIT_SUCCESS;
8202 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8206 if (rword == RES_UNTIL) {
8208 debug_printf_exec(": until expr is true: breaking\n");
8219 #if ENABLE_HUSH_LOOPS
8224 #if ENABLE_HUSH_CASE
8228 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8232 /* Select which version we will use */
8233 static int run_and_free_list(struct pipe *pi)
8236 debug_printf_exec("run_and_free_list entered\n");
8237 if (!G.o_opt[OPT_O_NOEXEC]) {
8238 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8239 rcode = run_list(pi);
8241 /* free_pipe_list has the side effect of clearing memory.
8242 * In the long run that function can be merged with run_list,
8243 * but doing that now would hobble the debugging effort. */
8245 debug_printf_exec("run_and_free_list return %d\n", rcode);
8250 static void install_sighandlers(unsigned mask)
8252 sighandler_t old_handler;
8254 while ((mask >>= 1) != 0) {
8258 old_handler = install_sighandler(sig, pick_sighandler(sig));
8259 /* POSIX allows shell to re-enable SIGCHLD
8260 * even if it was SIG_IGN on entry.
8261 * Therefore we skip IGN check for it:
8265 if (old_handler == SIG_IGN) {
8266 /* oops... restore back to IGN, and record this fact */
8267 install_sighandler(sig, old_handler);
8268 #if ENABLE_HUSH_TRAP
8270 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8272 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8278 /* Called a few times only (or even once if "sh -c") */
8279 static void install_special_sighandlers(void)
8283 /* Which signals are shell-special? */
8284 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8285 if (G_interactive_fd) {
8286 mask |= SPECIAL_INTERACTIVE_SIGS;
8287 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8288 mask |= SPECIAL_JOBSTOP_SIGS;
8290 /* Careful, do not re-install handlers we already installed */
8291 if (G.special_sig_mask != mask) {
8292 unsigned diff = mask & ~G.special_sig_mask;
8293 G.special_sig_mask = mask;
8294 install_sighandlers(diff);
8300 /* Set handlers to restore tty pgrp and exit */
8301 static void install_fatal_sighandlers(void)
8305 /* We will restore tty pgrp on these signals */
8307 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8308 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8309 + (1 << SIGBUS ) * HUSH_DEBUG
8310 + (1 << SIGSEGV) * HUSH_DEBUG
8311 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8313 /* bash 3.2 seems to handle these just like 'fatal' ones */
8316 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8317 * if we aren't interactive... but in this case
8318 * we never want to restore pgrp on exit, and this fn is not called
8320 /*+ (1 << SIGHUP )*/
8321 /*+ (1 << SIGTERM)*/
8322 /*+ (1 << SIGINT )*/
8324 G_fatal_sig_mask = mask;
8326 install_sighandlers(mask);
8330 static int set_mode(int state, char mode, const char *o_opt)
8335 G.o_opt[OPT_O_NOEXEC] = state;
8338 IF_HUSH_MODE_X(G_x_mode = state;)
8342 /* "set -+o" without parameter.
8343 * in bash, set -o produces this output:
8347 * We always use the second form.
8349 const char *p = o_opt_strings;
8352 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8358 idx = index_in_strings(o_opt_strings, o_opt);
8360 G.o_opt[idx] = state;
8364 return EXIT_FAILURE;
8366 return EXIT_SUCCESS;
8369 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8370 int hush_main(int argc, char **argv)
8373 OPT_login = (1 << 0),
8377 unsigned builtin_argc;
8379 struct variable *cur_var;
8380 struct variable *shell_ver;
8383 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8384 G.last_exitcode = EXIT_SUCCESS;
8386 #if ENABLE_HUSH_FAST
8387 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8390 G.argv0_for_re_execing = argv[0];
8392 /* Deal with HUSH_VERSION */
8393 shell_ver = xzalloc(sizeof(*shell_ver));
8394 shell_ver->flg_export = 1;
8395 shell_ver->flg_read_only = 1;
8396 /* Code which handles ${var<op>...} needs writable values for all variables,
8397 * therefore we xstrdup: */
8398 shell_ver->varstr = xstrdup(hush_version_str);
8399 /* Create shell local variables from the values
8400 * currently living in the environment */
8401 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8402 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8403 G.top_var = shell_ver;
8404 cur_var = G.top_var;
8407 char *value = strchr(*e, '=');
8408 if (value) { /* paranoia */
8409 cur_var->next = xzalloc(sizeof(*cur_var));
8410 cur_var = cur_var->next;
8411 cur_var->varstr = *e;
8412 cur_var->max_len = strlen(*e);
8413 cur_var->flg_export = 1;
8417 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8418 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8419 putenv(shell_ver->varstr);
8422 set_pwd_var(/*exp:*/ 1);
8424 #if ENABLE_HUSH_BASH_COMPAT
8425 /* Set (but not export) HOSTNAME unless already set */
8426 if (!get_local_var_value("HOSTNAME")) {
8429 set_local_var_from_halves("HOSTNAME", uts.nodename);
8431 /* bash also exports SHLVL and _,
8432 * and sets (but doesn't export) the following variables:
8434 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8435 * BASH_VERSION='3.2.0(1)-release'
8437 * MACHTYPE=i386-pc-linux-gnu
8439 * PPID=<NNNNN> - we also do it elsewhere
8450 * PIPESTATUS=([0]="0")
8451 * HISTFILE=/<xxx>/.bash_history
8455 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8457 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8468 #if ENABLE_FEATURE_EDITING
8469 G.line_input_state = new_line_input_t(FOR_SHELL);
8472 /* Initialize some more globals to non-zero values */
8473 cmdedit_update_prompt();
8475 die_func = restore_ttypgrp_and__exit;
8477 /* Shell is non-interactive at first. We need to call
8478 * install_special_sighandlers() if we are going to execute "sh <script>",
8479 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8480 * If we later decide that we are interactive, we run install_special_sighandlers()
8481 * in order to intercept (more) signals.
8485 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8486 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8489 opt = getopt(argc, argv, "+c:xinsl"
8492 # if ENABLE_HUSH_FUNCTIONS
8502 * sh ... -c 'script'
8503 * sh ... -c 'script' ARG0 [ARG1...]
8504 * On NOMMU, if builtin_argc != 0,
8505 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8506 * "" needs to be replaced with NULL
8507 * and BARGV vector fed to builtin function.
8508 * Note: the form without ARG0 never happens:
8509 * sh ... -c 'builtin' BARGV... ""
8512 G.root_pid = getpid();
8513 G.root_ppid = getppid();
8515 G.global_argv = argv + optind;
8516 G.global_argc = argc - optind;
8518 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8519 const struct built_in_command *x;
8521 install_special_sighandlers();
8522 x = find_builtin(optarg);
8523 if (x) { /* paranoia */
8524 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8525 G.global_argv += builtin_argc;
8526 G.global_argv[-1] = NULL; /* replace "" */
8528 G.last_exitcode = x->b_function(argv + optind - 1);
8532 if (!G.global_argv[0]) {
8533 /* -c 'script' (no params): prevent empty $0 */
8534 G.global_argv--; /* points to argv[i] of 'script' */
8535 G.global_argv[0] = argv[0];
8537 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8538 install_special_sighandlers();
8539 parse_and_run_string(optarg);
8542 /* Well, we cannot just declare interactiveness,
8543 * we have to have some stuff (ctty, etc) */
8544 /* G_interactive_fd++; */
8547 /* "-s" means "read from stdin", but this is how we always
8548 * operate, so simply do nothing here. */
8554 case '<': /* "big heredoc" support */
8555 full_write1_str(optarg);
8558 unsigned long long empty_trap_mask;
8560 G.root_pid = bb_strtou(optarg, &optarg, 16);
8562 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8564 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8566 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8568 builtin_argc = bb_strtou(optarg, &optarg, 16);
8570 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8571 if (empty_trap_mask != 0) {
8573 install_special_sighandlers();
8574 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8575 for (sig = 1; sig < NSIG; sig++) {
8576 if (empty_trap_mask & (1LL << sig)) {
8577 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8578 install_sighandler(sig, SIG_IGN);
8582 # if ENABLE_HUSH_LOOPS
8584 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8590 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8592 # if ENABLE_HUSH_FUNCTIONS
8594 struct function *funcp = new_function(optarg);
8595 /* funcp->name is already set to optarg */
8596 /* funcp->body is set to NULL. It's a special case. */
8597 funcp->body_as_string = argv[optind];
8605 if (set_mode(1, opt, NULL) == 0) /* no error */
8609 fprintf(stderr, "Usage: sh [FILE]...\n"
8610 " or: sh -c command [args]...\n\n");
8616 } /* option parsing loop */
8618 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8619 G.global_argc = argc - (optind - 1);
8620 G.global_argv = argv + (optind - 1);
8621 G.global_argv[0] = argv[0];
8624 G.root_pid = getpid();
8625 G.root_ppid = getppid();
8628 /* If we are login shell... */
8629 if (flags & OPT_login) {
8631 debug_printf("sourcing /etc/profile\n");
8632 input = fopen_for_read("/etc/profile");
8633 if (input != NULL) {
8634 remember_FILE(input);
8635 install_special_sighandlers();
8636 parse_and_run_file(input);
8637 fclose_and_forget(input);
8639 /* bash: after sourcing /etc/profile,
8640 * tries to source (in the given order):
8641 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8642 * stopping on first found. --noprofile turns this off.
8643 * bash also sources ~/.bash_logout on exit.
8644 * If called as sh, skips .bash_XXX files.
8648 if (G.global_argv[1]) {
8651 * "bash <script>" (which is never interactive (unless -i?))
8652 * sources $BASH_ENV here (without scanning $PATH).
8653 * If called as sh, does the same but with $ENV.
8654 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8658 debug_printf("running script '%s'\n", G.global_argv[0]);
8659 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8660 input = xfopen_for_read(G.global_argv[0]);
8661 xfunc_error_retval = 1;
8662 remember_FILE(input);
8663 install_special_sighandlers();
8664 parse_and_run_file(input);
8665 #if ENABLE_FEATURE_CLEAN_UP
8666 fclose_and_forget(input);
8671 /* Up to here, shell was non-interactive. Now it may become one.
8672 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8675 /* A shell is interactive if the '-i' flag was given,
8676 * or if all of the following conditions are met:
8678 * no arguments remaining or the -s flag given
8679 * standard input is a terminal
8680 * standard output is a terminal
8681 * Refer to Posix.2, the description of the 'sh' utility.
8684 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8685 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8686 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8687 if (G_saved_tty_pgrp < 0)
8688 G_saved_tty_pgrp = 0;
8690 /* try to dup stdin to high fd#, >= 255 */
8691 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8692 if (G_interactive_fd < 0) {
8693 /* try to dup to any fd */
8694 G_interactive_fd = dup(STDIN_FILENO);
8695 if (G_interactive_fd < 0) {
8697 G_interactive_fd = 0;
8698 G_saved_tty_pgrp = 0;
8701 // TODO: track & disallow any attempts of user
8702 // to (inadvertently) close/redirect G_interactive_fd
8704 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8705 if (G_interactive_fd) {
8706 close_on_exec_on(G_interactive_fd);
8708 if (G_saved_tty_pgrp) {
8709 /* If we were run as 'hush &', sleep until we are
8710 * in the foreground (tty pgrp == our pgrp).
8711 * If we get started under a job aware app (like bash),
8712 * make sure we are now in charge so we don't fight over
8713 * who gets the foreground */
8715 pid_t shell_pgrp = getpgrp();
8716 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8717 if (G_saved_tty_pgrp == shell_pgrp)
8719 /* send TTIN to ourself (should stop us) */
8720 kill(- shell_pgrp, SIGTTIN);
8724 /* Install more signal handlers */
8725 install_special_sighandlers();
8727 if (G_saved_tty_pgrp) {
8728 /* Set other signals to restore saved_tty_pgrp */
8729 install_fatal_sighandlers();
8730 /* Put ourselves in our own process group
8731 * (bash, too, does this only if ctty is available) */
8732 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8733 /* Grab control of the terminal */
8734 tcsetpgrp(G_interactive_fd, getpid());
8736 enable_restore_tty_pgrp_on_exit();
8738 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8740 const char *hp = get_local_var_value("HISTFILE");
8742 hp = get_local_var_value("HOME");
8744 hp = concat_path_file(hp, ".hush_history");
8749 G.line_input_state->hist_file = hp;
8750 //set_local_var(xasprintf("HISTFILE=%s", ...));
8752 # if ENABLE_FEATURE_SH_HISTFILESIZE
8753 hp = get_local_var_value("HISTFILESIZE");
8754 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8759 install_special_sighandlers();
8761 #elif ENABLE_HUSH_INTERACTIVE
8762 /* No job control compiled in, only prompt/line editing */
8763 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8764 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8765 if (G_interactive_fd < 0) {
8766 /* try to dup to any fd */
8767 G_interactive_fd = dup(STDIN_FILENO);
8768 if (G_interactive_fd < 0)
8770 G_interactive_fd = 0;
8773 if (G_interactive_fd) {
8774 close_on_exec_on(G_interactive_fd);
8776 install_special_sighandlers();
8778 /* We have interactiveness code disabled */
8779 install_special_sighandlers();
8782 * if interactive but not a login shell, sources ~/.bashrc
8783 * (--norc turns this off, --rcfile <file> overrides)
8786 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8787 /* note: ash and hush share this string */
8788 printf("\n\n%s %s\n"
8789 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8792 "hush - the humble shell"
8796 parse_and_run_file(stdin);
8799 hush_exit(G.last_exitcode);
8804 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8805 int msh_main(int argc, char **argv)
8807 bb_error_msg("msh is deprecated, please use hush instead");
8808 return hush_main(argc, argv);
8816 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8821 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8828 return applet_main_func(argc, argv - argc);
8831 static int FAST_FUNC builtin_test(char **argv)
8833 return run_applet_main(argv, test_main);
8836 static int FAST_FUNC builtin_echo(char **argv)
8838 return run_applet_main(argv, echo_main);
8841 #if ENABLE_HUSH_PRINTF
8842 static int FAST_FUNC builtin_printf(char **argv)
8844 return run_applet_main(argv, printf_main);
8848 static char **skip_dash_dash(char **argv)
8851 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8856 static int FAST_FUNC builtin_eval(char **argv)
8858 int rcode = EXIT_SUCCESS;
8860 argv = skip_dash_dash(argv);
8862 char *str = expand_strvec_to_string(argv);
8864 * eval "echo Hi; done" ("done" is syntax error):
8865 * "echo Hi" will not execute too.
8867 parse_and_run_string(str);
8869 rcode = G.last_exitcode;
8874 static int FAST_FUNC builtin_cd(char **argv)
8878 argv = skip_dash_dash(argv);
8880 if (newdir == NULL) {
8881 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8882 * bash says "bash: cd: HOME not set" and does nothing
8885 const char *home = get_local_var_value("HOME");
8886 newdir = home ? home : "/";
8888 if (chdir(newdir)) {
8889 /* Mimic bash message exactly */
8890 bb_perror_msg("cd: %s", newdir);
8891 return EXIT_FAILURE;
8893 /* Read current dir (get_cwd(1) is inside) and set PWD.
8894 * Note: do not enforce exporting. If PWD was unset or unexported,
8895 * set it again, but do not export. bash does the same.
8897 set_pwd_var(/*exp:*/ 0);
8898 return EXIT_SUCCESS;
8901 static int FAST_FUNC builtin_exec(char **argv)
8903 argv = skip_dash_dash(argv);
8904 if (argv[0] == NULL)
8905 return EXIT_SUCCESS; /* bash does this */
8907 /* Careful: we can end up here after [v]fork. Do not restore
8908 * tty pgrp then, only top-level shell process does that */
8909 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8910 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8912 /* TODO: if exec fails, bash does NOT exit! We do.
8913 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8914 * and tcsetpgrp, and this is inherently racy.
8916 execvp_or_die(argv);
8919 static int FAST_FUNC builtin_exit(char **argv)
8921 debug_printf_exec("%s()\n", __func__);
8923 /* interactive bash:
8924 * # trap "echo EEE" EXIT
8927 * There are stopped jobs.
8928 * (if there are _stopped_ jobs, running ones don't count)
8931 * EEE (then bash exits)
8933 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8936 /* note: EXIT trap is run by hush_exit */
8937 argv = skip_dash_dash(argv);
8938 if (argv[0] == NULL)
8939 hush_exit(G.last_exitcode);
8940 /* mimic bash: exit 123abc == exit 255 + error msg */
8941 xfunc_error_retval = 255;
8942 /* bash: exit -2 == exit 254, no error msg */
8943 hush_exit(xatoi(argv[0]) & 0xff);
8946 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
8947 static void print_escaped(const char *s)
8952 const char *p = strchrnul(s, '\'');
8953 /* print 'xxxx', possibly just '' */
8954 printf("'%.*s'", (int)(p - s), s);
8959 /* s points to '; print "'''...'''" */
8961 do putchar('\''); while (*++s == '\'');
8967 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
8968 # if !ENABLE_HUSH_LOCAL
8969 #define helper_export_local(argv, exp, lvl) \
8970 helper_export_local(argv, exp)
8972 static void helper_export_local(char **argv, int exp, int lvl)
8976 char *name_end = strchrnul(name, '=');
8978 /* So far we do not check that name is valid (TODO?) */
8980 if (*name_end == '\0') {
8981 struct variable *var, **vpp;
8983 vpp = get_ptr_to_local_var(name, name_end - name);
8984 var = vpp ? *vpp : NULL;
8986 if (exp == -1) { /* unexporting? */
8987 /* export -n NAME (without =VALUE) */
8989 var->flg_export = 0;
8990 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8992 } /* else: export -n NOT_EXISTING_VAR: no-op */
8995 if (exp == 1) { /* exporting? */
8996 /* export NAME (without =VALUE) */
8998 var->flg_export = 1;
8999 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9000 putenv(var->varstr);
9004 # if ENABLE_HUSH_LOCAL
9005 if (exp == 0 /* local? */
9006 && var && var->func_nest_level == lvl
9008 /* "local x=abc; ...; local x" - ignore second local decl */
9012 /* Exporting non-existing variable.
9013 * bash does not put it in environment,
9014 * but remembers that it is exported,
9015 * and does put it in env when it is set later.
9016 * We just set it to "" and export. */
9017 /* Or, it's "local NAME" (without =VALUE).
9018 * bash sets the value to "". */
9019 name = xasprintf("%s=", name);
9021 /* (Un)exporting/making local NAME=VALUE */
9022 name = xstrdup(name);
9024 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9029 #if ENABLE_HUSH_EXPORT
9030 static int FAST_FUNC builtin_export(char **argv)
9032 unsigned opt_unexport;
9034 #if ENABLE_HUSH_EXPORT_N
9035 /* "!": do not abort on errors */
9036 opt_unexport = getopt32(argv, "!n");
9037 if (opt_unexport == (uint32_t)-1)
9038 return EXIT_FAILURE;
9045 if (argv[0] == NULL) {
9052 /* ash emits: export VAR='VAL'
9053 * bash: declare -x VAR="VAL"
9054 * we follow ash example */
9055 const char *s = *e++;
9056 const char *p = strchr(s, '=');
9058 if (!p) /* wtf? take next variable */
9061 printf("export %.*s", (int)(p - s) + 1, s);
9062 print_escaped(p + 1);
9066 /*fflush_all(); - done after each builtin anyway */
9068 return EXIT_SUCCESS;
9071 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9073 return EXIT_SUCCESS;
9077 #if ENABLE_HUSH_LOCAL
9078 static int FAST_FUNC builtin_local(char **argv)
9080 if (G.func_nest_level == 0) {
9081 bb_error_msg("%s: not in a function", argv[0]);
9082 return EXIT_FAILURE; /* bash compat */
9084 helper_export_local(argv, 0, G.func_nest_level);
9085 return EXIT_SUCCESS;
9089 #if ENABLE_HUSH_UNSET
9090 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9091 static int FAST_FUNC builtin_unset(char **argv)
9096 /* "!": do not abort on errors */
9097 /* "+": stop at 1st non-option */
9098 opts = getopt32(argv, "!+vf");
9099 if (opts == (unsigned)-1)
9100 return EXIT_FAILURE;
9102 bb_error_msg("unset: -v and -f are exclusive");
9103 return EXIT_FAILURE;
9109 if (!(opts & 2)) { /* not -f */
9110 if (unset_local_var(*argv)) {
9111 /* unset <nonexistent_var> doesn't fail.
9112 * Error is when one tries to unset RO var.
9113 * Message was printed by unset_local_var. */
9117 # if ENABLE_HUSH_FUNCTIONS
9129 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9130 * built-in 'set' handler
9132 * set [-abCefhmnuvx] [-o option] [argument...]
9133 * set [+abCefhmnuvx] [+o option] [argument...]
9134 * set -- [argument...]
9137 * Implementations shall support the options in both their hyphen and
9138 * plus-sign forms. These options can also be specified as options to sh.
9140 * Write out all variables and their values: set
9141 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9142 * Turn on the -x and -v options: set -xv
9143 * Unset all positional parameters: set --
9144 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9145 * Set the positional parameters to the expansion of x, even if x expands
9146 * with a leading '-' or '+': set -- $x
9148 * So far, we only support "set -- [argument...]" and some of the short names.
9150 static int FAST_FUNC builtin_set(char **argv)
9153 char **pp, **g_argv;
9154 char *arg = *++argv;
9158 for (e = G.top_var; e; e = e->next)
9160 return EXIT_SUCCESS;
9164 if (strcmp(arg, "--") == 0) {
9168 if (arg[0] != '+' && arg[0] != '-')
9170 for (n = 1; arg[n]; ++n) {
9171 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9173 if (arg[n] == 'o' && argv[1])
9176 } while ((arg = *++argv) != NULL);
9177 /* Now argv[0] is 1st argument */
9180 return EXIT_SUCCESS;
9183 /* NB: G.global_argv[0] ($0) is never freed/changed */
9184 g_argv = G.global_argv;
9185 if (G.global_args_malloced) {
9191 G.global_args_malloced = 1;
9192 pp = xzalloc(sizeof(pp[0]) * 2);
9193 pp[0] = g_argv[0]; /* retain $0 */
9196 /* This realloc's G.global_argv */
9197 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9204 return EXIT_SUCCESS;
9206 /* Nothing known, so abort */
9208 bb_error_msg("set: %s: invalid option", arg);
9209 return EXIT_FAILURE;
9213 static int FAST_FUNC builtin_shift(char **argv)
9216 argv = skip_dash_dash(argv);
9220 if (n >= 0 && n < G.global_argc) {
9221 if (G_global_args_malloced) {
9224 free(G.global_argv[m++]);
9227 memmove(&G.global_argv[1], &G.global_argv[n+1],
9228 G.global_argc * sizeof(G.global_argv[0]));
9229 return EXIT_SUCCESS;
9231 return EXIT_FAILURE;
9234 #if ENABLE_HUSH_READ
9235 /* Interruptibility of read builtin in bash
9236 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9238 * Empty trap makes read ignore corresponding signal, for any signal.
9241 * - terminates non-interactive shell;
9242 * - interrupts read in interactive shell;
9243 * if it has non-empty trap:
9244 * - executes trap and returns to command prompt in interactive shell;
9245 * - executes trap and returns to read in non-interactive shell;
9247 * - is ignored (does not interrupt) read in interactive shell;
9248 * - terminates non-interactive shell;
9249 * if it has non-empty trap:
9250 * - executes trap and returns to read;
9252 * - terminates shell (regardless of interactivity);
9253 * if it has non-empty trap:
9254 * - executes trap and returns to read;
9256 static int FAST_FUNC builtin_read(char **argv)
9266 /* "!": do not abort on errors.
9267 * Option string must start with "sr" to match BUILTIN_READ_xxx
9269 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9270 if (read_flags == (uint32_t)-1)
9271 return EXIT_FAILURE;
9273 ifs = get_local_var_value("IFS"); /* can be NULL */
9276 r = shell_builtin_read(set_local_var_from_halves,
9286 if ((uintptr_t)r == 1 && errno == EINTR) {
9287 unsigned sig = check_and_run_traps();
9288 if (sig && sig != SIGINT)
9292 if ((uintptr_t)r > 1) {
9293 bb_error_msg("%s", r);
9294 r = (char*)(uintptr_t)1;
9297 return (uintptr_t)r;
9301 #if ENABLE_HUSH_TRAP
9302 static int FAST_FUNC builtin_trap(char **argv)
9308 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9313 /* No args: print all trapped */
9314 for (i = 0; i < NSIG; ++i) {
9317 print_escaped(G_traps[i]);
9318 /* note: bash adds "SIG", but only if invoked
9319 * as "bash". If called as "sh", or if set -o posix,
9320 * then it prints short signal names.
9321 * We are printing short names: */
9322 printf(" %s\n", get_signame(i));
9325 /*fflush_all(); - done after each builtin anyway */
9326 return EXIT_SUCCESS;
9330 /* If first arg is a number: reset all specified signals */
9331 sig = bb_strtou(*argv, NULL, 10);
9337 sighandler_t handler;
9339 sig = get_signum(*argv++);
9340 if (sig < 0 || sig >= NSIG) {
9342 /* Mimic bash message exactly */
9343 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9348 G_traps[sig] = xstrdup(new_cmd);
9350 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9351 get_signame(sig), sig, G_traps[sig]);
9353 /* There is no signal for 0 (EXIT) */
9358 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9360 /* We are removing trap handler */
9361 handler = pick_sighandler(sig);
9362 install_sighandler(sig, handler);
9367 if (!argv[1]) { /* no second arg */
9368 bb_error_msg("trap: invalid arguments");
9369 return EXIT_FAILURE;
9372 /* First arg is "-": reset all specified to default */
9373 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9374 /* Everything else: set arg as signal handler
9375 * (includes "" case, which ignores signal) */
9376 if (argv[0][0] == '-') {
9377 if (argv[0][1] == '\0') { /* "-" */
9378 /* new_cmd remains NULL: "reset these sigs" */
9381 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9384 /* else: "-something", no special meaning */
9389 goto process_sig_list;
9393 #if ENABLE_HUSH_TYPE
9394 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9395 static int FAST_FUNC builtin_type(char **argv)
9397 int ret = EXIT_SUCCESS;
9403 if (0) {} /* make conditional compile easier below */
9404 /*else if (find_alias(*argv))
9405 type = "an alias";*/
9406 #if ENABLE_HUSH_FUNCTIONS
9407 else if (find_function(*argv))
9408 type = "a function";
9410 else if (find_builtin(*argv))
9411 type = "a shell builtin";
9412 else if ((path = find_in_path(*argv)) != NULL)
9415 bb_error_msg("type: %s: not found", *argv);
9420 printf("%s is %s\n", *argv, type);
9429 static struct pipe *parse_jobspec(const char *str)
9434 if (sscanf(str, "%%%u", &jobnum) != 1) {
9436 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9438 bb_error_msg("bad argument '%s'", str);
9441 /* It is "%%", "%+" or "%" - current job */
9442 jobnum = G.last_jobid;
9444 bb_error_msg("no current job");
9448 for (pi = G.job_list; pi; pi = pi->next) {
9449 if (pi->jobid == jobnum) {
9453 bb_error_msg("%u: no such job", jobnum);
9457 /* built-in 'fg' and 'bg' handler */
9458 static int FAST_FUNC builtin_fg_bg(char **argv)
9463 if (!G_interactive_fd)
9464 return EXIT_FAILURE;
9466 /* If they gave us no args, assume they want the last backgrounded task */
9468 for (pi = G.job_list; pi; pi = pi->next) {
9469 if (pi->jobid == G.last_jobid) {
9473 bb_error_msg("%s: no current job", argv[0]);
9474 return EXIT_FAILURE;
9477 pi = parse_jobspec(argv[1]);
9479 return EXIT_FAILURE;
9481 /* TODO: bash prints a string representation
9482 * of job being foregrounded (like "sleep 1 | cat") */
9483 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9484 /* Put the job into the foreground. */
9485 tcsetpgrp(G_interactive_fd, pi->pgrp);
9488 /* Restart the processes in the job */
9489 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9490 for (i = 0; i < pi->num_cmds; i++) {
9491 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9493 pi->stopped_cmds = 0;
9495 i = kill(- pi->pgrp, SIGCONT);
9497 if (errno == ESRCH) {
9498 delete_finished_bg_job(pi);
9499 return EXIT_SUCCESS;
9501 bb_perror_msg("kill (SIGCONT)");
9504 if (argv[0][0] == 'f') {
9506 return checkjobs_and_fg_shell(pi);
9508 return EXIT_SUCCESS;
9512 #if ENABLE_HUSH_HELP
9513 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9515 const struct built_in_command *x;
9518 "Built-in commands:\n"
9519 "------------------\n");
9520 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9522 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9524 return EXIT_SUCCESS;
9528 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9529 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9531 show_history(G.line_input_state);
9532 return EXIT_SUCCESS;
9537 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9540 const char *status_string;
9542 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9543 for (job = G.job_list; job; job = job->next) {
9544 if (job->alive_cmds == job->stopped_cmds)
9545 status_string = "Stopped";
9547 status_string = "Running";
9549 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9551 return EXIT_SUCCESS;
9555 #if ENABLE_HUSH_MEMLEAK
9556 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9561 # ifdef M_TRIM_THRESHOLD
9562 /* Optional. Reduces probability of false positives */
9565 /* Crude attempt to find where "free memory" starts,
9566 * sans fragmentation. */
9568 l = (unsigned long)p;
9571 if (l < (unsigned long)p) l = (unsigned long)p;
9577 struct mallinfo mi = mallinfo();
9578 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9579 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9583 if (!G.memleak_value)
9584 G.memleak_value = l;
9586 l -= G.memleak_value;
9593 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9598 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9601 return EXIT_SUCCESS;
9604 static int FAST_FUNC builtin_source(char **argv)
9606 char *arg_path, *filename;
9609 char *args_need_save;
9610 #if ENABLE_HUSH_FUNCTIONS
9614 argv = skip_dash_dash(argv);
9617 /* bash says: "bash: .: filename argument required" */
9618 return 2; /* bash compat */
9621 if (!strchr(filename, '/')) {
9622 arg_path = find_in_path(filename);
9624 filename = arg_path;
9626 input = remember_FILE(fopen_or_warn(filename, "r"));
9629 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9630 /* POSIX: non-interactive shell should abort here,
9631 * not merely fail. So far no one complained :)
9633 return EXIT_FAILURE;
9636 #if ENABLE_HUSH_FUNCTIONS
9637 sv_flg = G_flag_return_in_progress;
9638 /* "we are inside sourced file, ok to use return" */
9639 G_flag_return_in_progress = -1;
9641 args_need_save = argv[1]; /* used as a boolean variable */
9643 save_and_replace_G_args(&sv, argv);
9645 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9646 G.last_exitcode = 0;
9647 parse_and_run_file(input);
9648 fclose_and_forget(input);
9650 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9651 restore_G_args(&sv, argv);
9652 #if ENABLE_HUSH_FUNCTIONS
9653 G_flag_return_in_progress = sv_flg;
9656 return G.last_exitcode;
9659 #if ENABLE_HUSH_UMASK
9660 static int FAST_FUNC builtin_umask(char **argv)
9667 argv = skip_dash_dash(argv);
9669 mode_t old_mask = mask;
9671 /* numeric umasks are taken as-is */
9672 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9673 if (!isdigit(argv[0][0]))
9675 mask = bb_parse_mode(argv[0], mask);
9676 if (!isdigit(argv[0][0]))
9678 if ((unsigned)mask > 0777) {
9681 * bash: umask: 'q': invalid symbolic mode operator
9682 * bash: umask: 999: octal number out of range
9684 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9689 printf("%04o\n", (unsigned) mask);
9690 /* fall through and restore mask which we set to 0 */
9694 return !rc; /* rc != 0 - success */
9698 #if ENABLE_HUSH_KILL
9699 static int FAST_FUNC builtin_kill(char **argv)
9703 # if ENABLE_HUSH_JOB
9704 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9712 if (argv[i][0] != '%')
9715 * "kill %N" - job kill
9716 * Converting to pgrp / pid kill
9718 pi = parse_jobspec(argv[i]);
9720 /* Eat bad jobspec */
9724 argv[j - 1] = argv[j];
9731 * In jobs started under job control, we signal
9732 * entire process group by kill -PGRP_ID.
9733 * This happens, f.e., in interactive shell.
9735 * Otherwise, we signal each child via
9736 * kill PID1 PID2 PID3.
9738 * sh -c 'sleep 1|sleep 1 & kill %1'
9739 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9740 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9742 n = G_interactive_fd ? 1 : pi->num_cmds;
9743 dst = alloca(n * sizeof(int)*4);
9745 if (G_interactive_fd)
9746 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9747 else for (j = 0; j < n; j++) {
9748 struct command *cmd = &pi->cmds[j];
9749 /* Skip exited members of the job */
9753 * kill_main has matching code to expect
9754 * leading space. Needed to not confuse
9755 * negative pids with "kill -SIGNAL_NO" syntax
9757 dst += sprintf(dst, " %u", (int)cmd->pid);
9760 } while (argv[++i]);
9764 if (argv[1] || ret == 0) {
9765 ret = run_applet_main(argv, kill_main);
9767 /* else: ret = 1, "kill %bad_jobspec" case */
9772 #if ENABLE_HUSH_WAIT
9773 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9774 #if !ENABLE_HUSH_JOB
9775 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9777 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9784 if (!sigisemptyset(&G.pending_set))
9787 /* waitpid is not interruptible by SA_RESTARTed
9788 * signals which we use. Thus, this ugly dance:
9791 /* Make sure possible SIGCHLD is stored in kernel's
9792 * pending signal mask before we call waitpid.
9793 * Or else we may race with SIGCHLD, lose it,
9794 * and get stuck in sigsuspend...
9796 sigfillset(&oldset); /* block all signals, remember old set */
9797 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9799 if (!sigisemptyset(&G.pending_set)) {
9800 /* Crap! we raced with some signal! */
9804 /*errno = 0; - checkjobs does this */
9805 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9806 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9807 debug_printf_exec("checkjobs:%d\n", ret);
9810 int rcode = job_exited_or_stopped(waitfor_pipe);
9811 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9814 sigprocmask(SIG_SETMASK, &oldset, NULL);
9819 /* if ECHILD, there are no children (ret is -1 or 0) */
9820 /* if ret == 0, no children changed state */
9821 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9822 if (errno == ECHILD || ret) {
9824 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9826 sigprocmask(SIG_SETMASK, &oldset, NULL);
9829 /* Wait for SIGCHLD or any other signal */
9830 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9831 /* Note: sigsuspend invokes signal handler */
9832 sigsuspend(&oldset);
9834 sigprocmask(SIG_SETMASK, &oldset, NULL);
9836 /* So, did we get a signal? */
9837 sig = check_and_run_traps();
9838 if (sig /*&& sig != SIGCHLD - always true */) {
9842 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9847 static int FAST_FUNC builtin_wait(char **argv)
9852 argv = skip_dash_dash(argv);
9853 if (argv[0] == NULL) {
9854 /* Don't care about wait results */
9855 /* Note 1: must wait until there are no more children */
9856 /* Note 2: must be interruptible */
9858 * $ sleep 3 & sleep 6 & wait
9863 * $ sleep 3 & sleep 6 & wait
9867 * ^C <-- after ~4 sec from keyboard
9870 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9874 pid_t pid = bb_strtou(*argv, NULL, 10);
9875 if (errno || pid <= 0) {
9877 if (argv[0][0] == '%') {
9878 struct pipe *wait_pipe;
9879 ret = 127; /* bash compat for bad jobspecs */
9880 wait_pipe = parse_jobspec(*argv);
9882 ret = job_exited_or_stopped(wait_pipe);
9884 ret = wait_for_child_or_signal(wait_pipe, 0);
9886 /* else: parse_jobspec() already emitted error msg */
9890 /* mimic bash message */
9891 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9893 continue; /* bash checks all argv[] */
9896 /* Do we have such child? */
9897 ret = waitpid(pid, &status, WNOHANG);
9900 if (errno == ECHILD) {
9901 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9902 /* "wait $!" but last bg task has already exited. Try:
9903 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9904 * In bash it prints exitcode 0, then 3.
9905 * In dash, it is 127.
9907 /* ret = G.last_bg_pid_exitstatus - FIXME */
9909 /* Example: "wait 1". mimic bash message */
9910 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9914 bb_perror_msg("wait %s", *argv);
9917 continue; /* bash checks all argv[] */
9920 /* Yes, and it still runs */
9921 ret = wait_for_child_or_signal(NULL, pid);
9923 /* Yes, and it just exited */
9924 process_wait_result(NULL, pid, status);
9925 ret = WEXITSTATUS(status);
9926 if (WIFSIGNALED(status))
9927 ret = 128 + WTERMSIG(status);
9935 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9936 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9939 def = bb_strtou(argv[1], NULL, 10);
9940 if (errno || def < def_min || argv[2]) {
9941 bb_error_msg("%s: bad arguments", argv[0]);
9949 #if ENABLE_HUSH_LOOPS
9950 static int FAST_FUNC builtin_break(char **argv)
9953 if (G.depth_of_loop == 0) {
9954 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9955 /* if we came from builtin_continue(), need to undo "= 1" */
9956 G.flag_break_continue = 0;
9957 return EXIT_SUCCESS; /* bash compat */
9959 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9961 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9962 if (depth == UINT_MAX)
9963 G.flag_break_continue = BC_BREAK;
9964 if (G.depth_of_loop < depth)
9965 G.depth_break_continue = G.depth_of_loop;
9967 return EXIT_SUCCESS;
9970 static int FAST_FUNC builtin_continue(char **argv)
9972 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9973 return builtin_break(argv);
9977 #if ENABLE_HUSH_FUNCTIONS
9978 static int FAST_FUNC builtin_return(char **argv)
9982 if (G_flag_return_in_progress != -1) {
9983 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9984 return EXIT_FAILURE; /* bash compat */
9987 G_flag_return_in_progress = 1;
9990 * out of range: wraps around at 256, does not error out
9991 * non-numeric param:
9992 * f() { false; return qwe; }; f; echo $?
9993 * bash: return: qwe: numeric argument required <== we do this
9994 * 255 <== we also do this
9996 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);