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:config HUSH_BRACE_EXPANSION
104 //config: bool "Brace expansion"
106 //config: depends on HUSH_BASH_COMPAT
108 //config: Enable {abc,def} extension.
110 //config:config HUSH_INTERACTIVE
111 //config: bool "Interactive mode"
113 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
115 //config: Enable interactive mode (prompt and command editing).
116 //config: Without this, hush simply reads and executes commands
117 //config: from stdin just like a shell script from a file.
118 //config: No prompt, no PS1/PS2 magic shell variables.
120 //config:config HUSH_SAVEHISTORY
121 //config: bool "Save command history to .hush_history"
123 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
125 //config:config HUSH_JOB
126 //config: bool "Job control"
128 //config: depends on HUSH_INTERACTIVE
130 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
131 //config: command (not entire shell), fg/bg builtins work. Without this option,
132 //config: "cmd &" still works by simply spawning a process and immediately
133 //config: prompting for next command (or executing next command in a script),
134 //config: but no separate process group is formed.
136 //config:config HUSH_TICK
137 //config: bool "Support process substitution"
139 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
141 //config: Enable `command` and $(command).
143 //config:config HUSH_IF
144 //config: bool "Support if/then/elif/else/fi"
146 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
148 //config:config HUSH_LOOPS
149 //config: bool "Support for, while and until loops"
151 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
153 //config:config HUSH_CASE
154 //config: bool "Support case ... esac statement"
156 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
158 //config: Enable case ... esac statement. +400 bytes.
160 //config:config HUSH_FUNCTIONS
161 //config: bool "Support funcname() { commands; } syntax"
163 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
165 //config: Enable support for shell functions. +800 bytes.
167 //config:config HUSH_LOCAL
168 //config: bool "local builtin"
170 //config: depends on HUSH_FUNCTIONS
172 //config: Enable support for local variables in functions.
174 //config:config HUSH_RANDOM_SUPPORT
175 //config: bool "Pseudorandom generator and $RANDOM variable"
177 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
179 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
180 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
182 //config:config HUSH_MODE_X
183 //config: bool "Support 'hush -x' option and 'set -x' command"
185 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
187 //config: This instructs hush to print commands before execution.
188 //config: Adds ~300 bytes.
190 //config:config HUSH_ECHO
191 //config: bool "echo builtin"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config:config HUSH_PRINTF
196 //config: bool "printf builtin"
198 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
200 //config:config HUSH_TEST
201 //config: bool "test builtin"
203 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
205 //config:config HUSH_HELP
206 //config: bool "help builtin"
208 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
210 //config:config HUSH_EXPORT
211 //config: bool "export builtin"
213 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
215 //config:config HUSH_EXPORT_N
216 //config: bool "Support 'export -n' option"
218 //config: depends on HUSH_EXPORT
220 //config: export -n unexports variables. It is a bash extension.
222 //config:config HUSH_KILL
223 //config: bool "kill builtin (supports kill %jobspec)"
225 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
227 //config:config HUSH_WAIT
228 //config: bool "wait builtin"
230 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
232 //config:config HUSH_TRAP
233 //config: bool "trap builtin"
235 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
237 //config:config HUSH_TYPE
238 //config: bool "type builtin"
240 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
242 //config:config HUSH_READ
243 //config: bool "read builtin"
245 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
247 //config:config HUSH_SET
248 //config: bool "set builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config:config HUSH_UNSET
253 //config: bool "unset builtin"
255 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
257 //config:config HUSH_ULIMIT
258 //config: bool "ulimit builtin"
260 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
262 //config:config HUSH_UMASK
263 //config: bool "umask builtin"
265 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
267 //config:config HUSH_MEMLEAK
268 //config: bool "memleak builtin (debugging)"
270 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config: bool "msh (deprecated: aliased to hush)"
275 //config: select HUSH
277 //config: msh is deprecated and will be removed, please migrate to hush.
279 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
280 // APPLET_ODDNAME:name main location suid_type help
281 //applet:IF_MSH( APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
282 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
283 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
285 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
286 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
287 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
288 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
290 /* -i (interactive) and -s (read stdin) are also accepted,
291 * but currently do nothing, therefore aren't shown in help.
292 * NOMMU-specific options are not meant to be used by users,
293 * therefore we don't show them either.
295 //usage:#define hush_trivial_usage
296 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
297 //usage:#define hush_full_usage "\n\n"
298 //usage: "Unix shell interpreter"
300 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
301 || defined(__APPLE__) \
303 # include <malloc.h> /* for malloc_trim */
306 /* #include <dmalloc.h> */
308 # include <fnmatch.h>
310 #include <sys/utsname.h> /* for setting $HOSTNAME */
312 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
314 #include "shell_common.h"
317 #if ENABLE_HUSH_RANDOM_SUPPORT
320 # define CLEAR_RANDOM_T(rnd) ((void)0)
322 #ifndef F_DUPFD_CLOEXEC
323 # define F_DUPFD_CLOEXEC F_DUPFD
326 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
330 /* So far, all bash compat is controlled by one config option */
331 /* Separate defines document which part of code implements what */
332 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
333 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
334 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
335 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
336 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
340 #define LEAK_HUNTING 0
341 #define BUILD_AS_NOMMU 0
342 /* Enable/disable sanity checks. Ok to enable in production,
343 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
344 * Keeping 1 for now even in released versions.
347 /* Slightly bigger (+200 bytes), but faster hush.
348 * So far it only enables a trick with counting SIGCHLDs and forks,
349 * which allows us to do fewer waitpid's.
350 * (we can detect a case where neither forks were done nor SIGCHLDs happened
351 * and therefore waitpid will return the same result as last time)
353 #define ENABLE_HUSH_FAST 0
354 /* TODO: implement simplified code for users which do not need ${var%...} ops
355 * So far ${var%...} ops are always enabled:
357 #define ENABLE_HUSH_DOLLAR_OPS 1
362 # undef USE_FOR_NOMMU
365 # define USE_FOR_NOMMU(...) __VA_ARGS__
366 # define USE_FOR_MMU(...)
369 #include "NUM_APPLETS.h"
371 /* STANDALONE does not make sense, and won't compile */
372 # undef CONFIG_FEATURE_SH_STANDALONE
373 # undef ENABLE_FEATURE_SH_STANDALONE
374 # undef IF_FEATURE_SH_STANDALONE
375 # undef IF_NOT_FEATURE_SH_STANDALONE
376 # define ENABLE_FEATURE_SH_STANDALONE 0
377 # define IF_FEATURE_SH_STANDALONE(...)
378 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
381 #if !ENABLE_HUSH_INTERACTIVE
382 # undef ENABLE_FEATURE_EDITING
383 # define ENABLE_FEATURE_EDITING 0
384 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
385 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
386 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
387 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
390 /* Do we support ANY keywords? */
391 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
392 # define HAS_KEYWORDS 1
393 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
394 # define IF_HAS_NO_KEYWORDS(...)
396 # define HAS_KEYWORDS 0
397 # define IF_HAS_KEYWORDS(...)
398 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
401 /* If you comment out one of these below, it will be #defined later
402 * to perform debug printfs to stderr: */
403 #define debug_printf(...) do {} while (0)
404 /* Finer-grained debug switches */
405 #define debug_printf_parse(...) do {} while (0)
406 #define debug_print_tree(a, b) do {} while (0)
407 #define debug_printf_exec(...) do {} while (0)
408 #define debug_printf_env(...) do {} while (0)
409 #define debug_printf_jobs(...) do {} while (0)
410 #define debug_printf_expand(...) do {} while (0)
411 #define debug_printf_varexp(...) do {} while (0)
412 #define debug_printf_glob(...) do {} while (0)
413 #define debug_printf_list(...) do {} while (0)
414 #define debug_printf_subst(...) do {} while (0)
415 #define debug_printf_clean(...) do {} while (0)
417 #define ERR_PTR ((void*)(long)1)
419 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
421 #define _SPECIAL_VARS_STR "_*@$!?#"
422 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
423 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
424 #if BASH_PATTERN_SUBST
425 /* Support / and // replace ops */
426 /* Note that // is stored as \ in "encoded" string representation */
427 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
428 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
429 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
431 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
432 # define VAR_SUBST_OPS "%#:-=+?"
433 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
436 #define SPECIAL_VAR_SYMBOL 3
440 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
442 /* This supports saving pointers malloced in vfork child,
443 * to be freed in the parent.
446 typedef struct nommu_save_t {
448 struct variable *old_vars;
450 char **argv_from_re_execing;
463 #if ENABLE_HUSH_LOOPS
470 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
475 /* three pseudo-keywords support contrived "case" syntax: */
476 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
477 RES_MATCH , /* "word)" */
478 RES_CASE_BODY, /* "this command is inside CASE" */
485 typedef struct o_string {
487 int length; /* position where data is appended */
490 /* At least some part of the string was inside '' or "",
491 * possibly empty one: word"", wo''rd etc. */
492 smallint has_quoted_part;
493 smallint has_empty_slot;
494 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
497 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
499 /* Protect newly added chars against globbing
500 * by prepending \ to *, ?, [, \ */
501 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
504 MAYBE_ASSIGNMENT = 0,
505 DEFINITELY_ASSIGNMENT = 1,
507 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
510 /* Used for initialization: o_string foo = NULL_O_STRING; */
511 #define NULL_O_STRING { NULL }
513 #ifndef debug_printf_parse
514 static const char *const assignment_flag[] = {
516 "DEFINITELY_ASSIGNMENT",
522 typedef struct in_str {
524 #if ENABLE_HUSH_INTERACTIVE
525 smallint promptmode; /* 0: PS1, 1: PS2 */
532 /* The descrip member of this structure is only used to make
533 * debugging output pretty */
534 static const struct {
536 signed char default_fd;
539 { O_RDONLY, 0, "<" },
540 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
541 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
542 { O_CREAT|O_RDWR, 1, "<>" },
543 { O_RDONLY, 0, "<<" },
544 /* Should not be needed. Bogus default_fd helps in debugging */
545 /* { O_RDONLY, 77, "<<" }, */
548 struct redir_struct {
549 struct redir_struct *next;
550 char *rd_filename; /* filename */
551 int rd_fd; /* fd to redirect */
552 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
554 smallint rd_type; /* (enum redir_type) */
555 /* note: for heredocs, rd_filename contains heredoc delimiter,
556 * and subsequently heredoc itself; and rd_dup is a bitmask:
557 * bit 0: do we need to trim leading tabs?
558 * bit 1: is heredoc quoted (<<'delim' syntax) ?
561 typedef enum redir_type {
563 REDIRECT_OVERWRITE = 1,
566 REDIRECT_HEREDOC = 4,
567 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
570 REDIRFD_SYNTAX_ERR = -2,
571 REDIRFD_TO_FILE = -1,
572 /* otherwise, rd_fd is redirected to rd_dup */
574 HEREDOC_SKIPTABS = 1,
580 pid_t pid; /* 0 if exited */
581 int assignment_cnt; /* how many argv[i] are assignments? */
582 smallint cmd_type; /* CMD_xxx */
584 #define CMD_SUBSHELL 1
586 /* used for "[[ EXPR ]]" */
587 # define CMD_SINGLEWORD_NOGLOB 2
589 #if ENABLE_HUSH_FUNCTIONS
590 # define CMD_FUNCDEF 3
593 smalluint cmd_exitcode;
594 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
597 char *group_as_string;
599 #if ENABLE_HUSH_FUNCTIONS
600 struct function *child_func;
601 /* This field is used to prevent a bug here:
602 * while...do f1() {a;}; f1; f1() {b;}; f1; done
603 * When we execute "f1() {a;}" cmd, we create new function and clear
604 * cmd->group, cmd->group_as_string, cmd->argv[0].
605 * When we execute "f1() {b;}", we notice that f1 exists,
606 * and that its "parent cmd" struct is still "alive",
607 * we put those fields back into cmd->xxx
608 * (struct function has ->parent_cmd ptr to facilitate that).
609 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
610 * Without this trick, loop would execute a;b;b;b;...
611 * instead of correct sequence a;b;a;b;...
612 * When command is freed, it severs the link
613 * (sets ->child_func->parent_cmd to NULL).
616 char **argv; /* command name and arguments */
617 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
618 * and on execution these are substituted with their values.
619 * Substitution can make _several_ words out of one argv[n]!
620 * Example: argv[0]=='.^C*^C.' here: echo .$*.
621 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
623 struct redir_struct *redirects; /* I/O redirections */
625 /* Is there anything in this command at all? */
626 #define IS_NULL_CMD(cmd) \
627 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
631 int num_cmds; /* total number of commands in pipe */
632 int alive_cmds; /* number of commands running (not exited) */
633 int stopped_cmds; /* number of commands alive, but stopped */
635 unsigned jobid; /* job number */
636 pid_t pgrp; /* process group ID for the job */
637 char *cmdtext; /* name of job */
639 struct command *cmds; /* array of commands in pipe */
640 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
641 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
642 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
644 typedef enum pipe_style {
650 /* Is there anything in this pipe at all? */
651 #define IS_NULL_PIPE(pi) \
652 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
654 /* This holds pointers to the various results of parsing */
655 struct parse_context {
656 /* linked list of pipes */
657 struct pipe *list_head;
658 /* last pipe (being constructed right now) */
660 /* last command in pipe (being constructed right now) */
661 struct command *command;
662 /* last redirect in command->redirects list */
663 struct redir_struct *pending_redirect;
669 smallint ctx_inverted; /* "! cmd | cmd" */
671 smallint ctx_dsemicolon; /* ";;" seen */
673 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
675 /* group we are enclosed in:
676 * example: "if pipe1; pipe2; then pipe3; fi"
677 * when we see "if" or "then", we malloc and copy current context,
678 * and make ->stack point to it. then we parse pipeN.
679 * when closing "then" / fi" / whatever is found,
680 * we move list_head into ->stack->command->group,
681 * copy ->stack into current context, and delete ->stack.
682 * (parsing of { list } and ( list ) doesn't use this method)
684 struct parse_context *stack;
688 /* On program start, environ points to initial environment.
689 * putenv adds new pointers into it, unsetenv removes them.
690 * Neither of these (de)allocates the strings.
691 * setenv allocates new strings in malloc space and does putenv,
692 * and thus setenv is unusable (leaky) for shell's purposes */
693 #define setenv(...) setenv_is_leaky_dont_use()
695 struct variable *next;
696 char *varstr; /* points to "name=" portion */
697 #if ENABLE_HUSH_LOCAL
698 unsigned func_nest_level;
700 int max_len; /* if > 0, name is part of initial env; else name is malloced */
701 smallint flg_export; /* putenv should be done on this var */
702 smallint flg_read_only;
710 #if ENABLE_HUSH_FUNCTIONS
712 struct function *next;
714 struct command *parent_cmd;
717 char *body_as_string;
723 /* set -/+o OPT support. (TODO: make it optional)
724 * bash supports the following opts:
735 * interactive-comments on
753 static const char o_opt_strings[] ALIGN1 =
756 #if ENABLE_HUSH_MODE_X
763 #if ENABLE_HUSH_MODE_X
771 struct FILE_list *next;
777 /* "Globals" within this file */
778 /* Sorted roughly by size (smaller offsets == smaller code) */
780 /* interactive_fd != 0 means we are an interactive shell.
781 * If we are, then saved_tty_pgrp can also be != 0, meaning
782 * that controlling tty is available. With saved_tty_pgrp == 0,
783 * job control still works, but terminal signals
784 * (^C, ^Z, ^Y, ^\) won't work at all, and background
785 * process groups can only be created with "cmd &".
786 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
787 * to give tty to the foreground process group,
788 * and will take it back when the group is stopped (^Z)
791 #if ENABLE_HUSH_INTERACTIVE
792 /* 'interactive_fd' is a fd# open to ctty, if we have one
793 * _AND_ if we decided to act interactively */
797 # define G_interactive_fd (G.interactive_fd)
799 # define G_interactive_fd 0
801 #if ENABLE_FEATURE_EDITING
802 line_input_t *line_input_state;
807 #if ENABLE_HUSH_RANDOM_SUPPORT
813 pid_t saved_tty_pgrp;
814 struct pipe *job_list;
815 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
817 # define G_saved_tty_pgrp 0
819 char o_opt[NUM_OPT_O];
820 #if ENABLE_HUSH_MODE_X
821 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
825 smallint flag_SIGINT;
826 #if ENABLE_HUSH_LOOPS
827 smallint flag_break_continue;
829 #if ENABLE_HUSH_FUNCTIONS
830 /* 0: outside of a function (or sourced file)
831 * -1: inside of a function, ok to use return builtin
832 * 1: return is invoked, skip all till end of func
834 smallint flag_return_in_progress;
835 # define G_flag_return_in_progress (G.flag_return_in_progress)
837 # define G_flag_return_in_progress 0
839 smallint exiting; /* used to prevent EXIT trap recursion */
840 /* These four support $?, $#, and $1 */
841 smalluint last_exitcode;
843 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
844 smalluint global_args_malloced;
845 # define G_global_args_malloced (G.global_args_malloced)
847 # define G_global_args_malloced 0
849 /* how many non-NULL argv's we have. NB: $# + 1 */
853 char *argv0_for_re_execing;
855 #if ENABLE_HUSH_LOOPS
856 unsigned depth_break_continue;
857 unsigned depth_of_loop;
861 struct variable *top_var;
862 char **expanded_assignments;
863 #if ENABLE_HUSH_FUNCTIONS
864 struct function *top_func;
865 # if ENABLE_HUSH_LOCAL
866 struct variable **shadowed_vars_pp;
867 unsigned func_nest_level;
870 /* Signal and trap handling */
872 unsigned count_SIGCHLD;
873 unsigned handled_SIGCHLD;
874 smallint we_have_children;
876 struct FILE_list *FILE_list;
877 /* Which signals have non-DFL handler (even with no traps set)?
878 * Set at the start to:
879 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
880 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
881 * The rest is cleared right before execv syscalls.
882 * Other than these two times, never modified.
884 unsigned special_sig_mask;
886 unsigned fatal_sig_mask;
887 # define G_fatal_sig_mask (G.fatal_sig_mask)
889 # define G_fatal_sig_mask 0
892 char **traps; /* char *traps[NSIG] */
893 # define G_traps G.traps
895 # define G_traps ((char**)NULL)
897 sigset_t pending_set;
898 #if ENABLE_HUSH_MEMLEAK
899 unsigned long memleak_value;
905 #if ENABLE_FEATURE_EDITING
906 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
909 #define G (*ptr_to_globals)
910 /* Not #defining name to G.name - this quickly gets unwieldy
911 * (too many defines). Also, I actually prefer to see when a variable
912 * is global, thus "G." prefix is a useful hint */
913 #define INIT_G() do { \
914 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
915 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
916 sigfillset(&G.sa.sa_mask); \
917 G.sa.sa_flags = SA_RESTART; \
921 /* Function prototypes for builtins */
922 static int builtin_cd(char **argv) FAST_FUNC;
924 static int builtin_echo(char **argv) FAST_FUNC;
926 static int builtin_eval(char **argv) FAST_FUNC;
927 static int builtin_exec(char **argv) FAST_FUNC;
928 static int builtin_exit(char **argv) FAST_FUNC;
929 #if ENABLE_HUSH_EXPORT
930 static int builtin_export(char **argv) FAST_FUNC;
933 static int builtin_fg_bg(char **argv) FAST_FUNC;
934 static int builtin_jobs(char **argv) FAST_FUNC;
937 static int builtin_help(char **argv) FAST_FUNC;
939 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
940 static int builtin_history(char **argv) FAST_FUNC;
942 #if ENABLE_HUSH_LOCAL
943 static int builtin_local(char **argv) FAST_FUNC;
945 #if ENABLE_HUSH_MEMLEAK
946 static int builtin_memleak(char **argv) FAST_FUNC;
948 #if ENABLE_HUSH_PRINTF
949 static int builtin_printf(char **argv) FAST_FUNC;
951 static int builtin_pwd(char **argv) FAST_FUNC;
953 static int builtin_read(char **argv) FAST_FUNC;
956 static int builtin_set(char **argv) FAST_FUNC;
958 static int builtin_shift(char **argv) FAST_FUNC;
959 static int builtin_source(char **argv) FAST_FUNC;
960 #if ENABLE_HUSH_TEST || BASH_TEST2
961 static int builtin_test(char **argv) FAST_FUNC;
964 static int builtin_trap(char **argv) FAST_FUNC;
967 static int builtin_type(char **argv) FAST_FUNC;
969 static int builtin_true(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_UMASK
971 static int builtin_umask(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_UNSET
974 static int builtin_unset(char **argv) FAST_FUNC;
977 static int builtin_kill(char **argv) FAST_FUNC;
980 static int builtin_wait(char **argv) FAST_FUNC;
982 #if ENABLE_HUSH_LOOPS
983 static int builtin_break(char **argv) FAST_FUNC;
984 static int builtin_continue(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_FUNCTIONS
987 static int builtin_return(char **argv) FAST_FUNC;
990 /* Table of built-in functions. They can be forked or not, depending on
991 * context: within pipes, they fork. As simple commands, they do not.
992 * When used in non-forking context, they can change global variables
993 * in the parent shell process. If forked, of course they cannot.
994 * For example, 'unset foo | whatever' will parse and run, but foo will
995 * still be set at the end. */
996 struct built_in_command {
998 int (*b_function)(char **argv) FAST_FUNC;
1000 const char *b_descr;
1001 # define BLTIN(cmd, func, help) { cmd, func, help }
1003 # define BLTIN(cmd, func, help) { cmd, func }
1007 static const struct built_in_command bltins1[] = {
1008 BLTIN("." , builtin_source , "Run commands in file"),
1009 BLTIN(":" , builtin_true , NULL),
1011 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1013 #if ENABLE_HUSH_LOOPS
1014 BLTIN("break" , builtin_break , "Exit loop"),
1016 BLTIN("cd" , builtin_cd , "Change directory"),
1017 #if ENABLE_HUSH_LOOPS
1018 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1020 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1021 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1022 BLTIN("exit" , builtin_exit , NULL),
1023 #if ENABLE_HUSH_EXPORT
1024 BLTIN("export" , builtin_export , "Set environment variables"),
1027 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1029 #if ENABLE_HUSH_HELP
1030 BLTIN("help" , builtin_help , NULL),
1032 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1033 BLTIN("history" , builtin_history , "Show history"),
1036 BLTIN("jobs" , builtin_jobs , "List jobs"),
1038 #if ENABLE_HUSH_KILL
1039 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1041 #if ENABLE_HUSH_LOCAL
1042 BLTIN("local" , builtin_local , "Set local variables"),
1044 #if ENABLE_HUSH_MEMLEAK
1045 BLTIN("memleak" , builtin_memleak , NULL),
1047 #if ENABLE_HUSH_READ
1048 BLTIN("read" , builtin_read , "Input into variable"),
1050 #if ENABLE_HUSH_FUNCTIONS
1051 BLTIN("return" , builtin_return , "Return from function"),
1054 BLTIN("set" , builtin_set , "Set positional parameters"),
1056 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1058 BLTIN("source" , builtin_source , NULL),
1060 #if ENABLE_HUSH_TRAP
1061 BLTIN("trap" , builtin_trap , "Trap signals"),
1063 BLTIN("true" , builtin_true , NULL),
1064 #if ENABLE_HUSH_TYPE
1065 BLTIN("type" , builtin_type , "Show command type"),
1067 #if ENABLE_HUSH_ULIMIT
1068 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1070 #if ENABLE_HUSH_UMASK
1071 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1073 #if ENABLE_HUSH_UNSET
1074 BLTIN("unset" , builtin_unset , "Unset variables"),
1076 #if ENABLE_HUSH_WAIT
1077 BLTIN("wait" , builtin_wait , "Wait for process"),
1080 /* These builtins won't be used if we are on NOMMU and need to re-exec
1081 * (it's cheaper to run an external program in this case):
1083 static const struct built_in_command bltins2[] = {
1084 #if ENABLE_HUSH_TEST
1085 BLTIN("[" , builtin_test , NULL),
1088 BLTIN("[[" , builtin_test , NULL),
1090 #if ENABLE_HUSH_ECHO
1091 BLTIN("echo" , builtin_echo , NULL),
1093 #if ENABLE_HUSH_PRINTF
1094 BLTIN("printf" , builtin_printf , NULL),
1096 BLTIN("pwd" , builtin_pwd , NULL),
1097 #if ENABLE_HUSH_TEST
1098 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 && BB_MMU
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 don't 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 don't 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 BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || 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 exercises 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);
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 BASH_SUBSTR || BASH_PATTERN_SUBST
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);
4259 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4265 /* we look for closing )) of $((EXPR)) */
4266 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4267 i_getch(input); /* eat second ')' */
4272 if (ch == '(' || ch == '{') {
4273 ch = (ch == '(' ? ')' : '}');
4274 if (!add_till_closing_bracket(dest, input, ch))
4280 if (!add_till_single_quote(dest, input))
4286 if (!add_till_double_quote(dest, input))
4292 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4298 /* \x. Copy verbatim. Important for \(, \) */
4299 ch = i_getch(input);
4301 syntax_error_unterm_ch(')');
4306 /* "backslash+newline", ignore both */
4307 o_delchr(dest); /* undo insertion of '\' */
4317 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4319 /* Return code: 0 for OK, 1 for syntax error */
4321 #define parse_dollar(as_string, dest, input, quote_mask) \
4322 parse_dollar(dest, input, quote_mask)
4323 #define as_string NULL
4325 static int parse_dollar(o_string *as_string,
4327 struct in_str *input, unsigned char quote_mask)
4329 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4331 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4333 ch = i_getch(input);
4334 nommu_addchr(as_string, ch);
4336 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4338 debug_printf_parse(": '%c'\n", ch);
4339 o_addchr(dest, ch | quote_mask);
4341 ch = i_peek_and_eat_bkslash_nl(input);
4342 if (!isalnum(ch) && ch != '_') {
4343 /* End of variable name reached */
4346 ch = i_getch(input);
4347 nommu_addchr(as_string, ch);
4349 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4350 } else if (isdigit(ch)) {
4352 ch = i_getch(input);
4353 nommu_addchr(as_string, ch);
4354 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4355 debug_printf_parse(": '%c'\n", ch);
4356 o_addchr(dest, ch | quote_mask);
4357 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4358 } else switch (ch) {
4360 case '!': /* last bg pid */
4361 case '?': /* last exit code */
4362 case '#': /* number of args */
4363 case '*': /* args */
4364 case '@': /* args */
4365 goto make_one_char_var;
4367 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4369 ch = i_getch(input); /* eat '{' */
4370 nommu_addchr(as_string, ch);
4372 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4373 /* It should be ${?}, or ${#var},
4374 * or even ${?+subst} - operator acting on a special variable,
4375 * or the beginning of variable name.
4378 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4381 syntax_error_unterm_str("${name}");
4382 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4385 nommu_addchr(as_string, ch);
4388 /* It's possible to just call add_till_closing_bracket() at this point.
4389 * However, this regresses some of our testsuite cases
4390 * which check invalid constructs like ${%}.
4391 * Oh well... let's check that the var name part is fine... */
4397 debug_printf_parse(": '%c'\n", ch);
4399 ch = i_getch(input);
4400 nommu_addchr(as_string, ch);
4404 if (!isalnum(ch) && ch != '_') {
4406 unsigned char last_ch;
4407 /* handle parameter expansions
4408 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4410 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4411 goto bad_dollar_syntax;
4413 /* Eat everything until closing '}' (or ':') */
4417 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4419 /* It's ${var:N[:M]} thing */
4420 end_ch = '}' * 0x100 + ':';
4422 if (BASH_PATTERN_SUBST
4425 /* It's ${var/[/]pattern[/repl]} thing */
4426 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4428 nommu_addchr(as_string, '/');
4431 end_ch = '}' * 0x100 + '/';
4437 #if ENABLE_HUSH_DOLLAR_OPS
4438 last_ch = add_till_closing_bracket(dest, input, end_ch);
4439 if (last_ch == 0) /* error? */
4442 #error Simple code to only allow ${var} is not implemented
4445 o_addstr(as_string, dest->data + pos);
4446 o_addchr(as_string, last_ch);
4449 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4450 && (end_ch & 0xff00)
4452 /* close the first block: */
4453 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4454 /* while parsing N from ${var:N[:M]}
4455 * or pattern from ${var/[/]pattern[/repl]} */
4456 if ((end_ch & 0xff) == last_ch) {
4457 /* got ':' or '/'- parse the rest */
4462 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4463 /* it's ${var:N} - emulate :999999999 */
4464 o_addstr(dest, "999999999");
4465 } /* else: it's ${var/[/]pattern} */
4470 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4473 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4477 ch = i_getch(input);
4478 nommu_addchr(as_string, ch);
4479 # if ENABLE_FEATURE_SH_MATH
4480 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4481 ch = i_getch(input);
4482 nommu_addchr(as_string, ch);
4483 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4484 o_addchr(dest, /*quote_mask |*/ '+');
4487 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4488 return 0; /* error */
4490 o_addstr(as_string, dest->data + pos);
4491 o_addchr(as_string, ')');
4492 o_addchr(as_string, ')');
4494 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4498 # if ENABLE_HUSH_TICK
4499 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4500 o_addchr(dest, quote_mask | '`');
4503 if (!add_till_closing_bracket(dest, input, ')'))
4504 return 0; /* error */
4506 o_addstr(as_string, dest->data + pos);
4507 o_addchr(as_string, ')');
4509 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4515 ch = i_getch(input);
4516 nommu_addchr(as_string, ch);
4517 ch = i_peek_and_eat_bkslash_nl(input);
4518 if (isalnum(ch)) { /* it's $_name or $_123 */
4523 /* TODO: $_ and $-: */
4524 /* $_ Shell or shell script name; or last argument of last command
4525 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4526 * but in command's env, set to full pathname used to invoke it */
4527 /* $- Option flags set by set builtin or shell options (-i etc) */
4529 o_addQchr(dest, '$');
4531 debug_printf_parse("parse_dollar return 1 (ok)\n");
4537 # if BASH_PATTERN_SUBST
4538 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4539 encode_string(dest, input, dquote_end, process_bkslash)
4541 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4542 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4543 encode_string(dest, input, dquote_end)
4545 #define as_string NULL
4549 # if BASH_PATTERN_SUBST
4550 /* all parameters are needed, no macro tricks */
4552 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4553 encode_string(as_string, dest, input, dquote_end)
4556 static int encode_string(o_string *as_string,
4558 struct in_str *input,
4560 int process_bkslash)
4562 #if !BASH_PATTERN_SUBST
4563 const int process_bkslash = 1;
4569 ch = i_getch(input);
4571 nommu_addchr(as_string, ch);
4572 if (ch == dquote_end) { /* may be only '"' or EOF */
4573 debug_printf_parse("encode_string return 1 (ok)\n");
4576 /* note: can't move it above ch == dquote_end check! */
4578 syntax_error_unterm_ch('"');
4579 return 0; /* error */
4583 next = i_peek(input);
4585 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4586 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4587 if (process_bkslash && ch == '\\') {
4589 syntax_error("\\<eof>");
4593 * "The backslash retains its special meaning [in "..."]
4594 * only when followed by one of the following characters:
4595 * $, `, ", \, or <newline>. A double quote may be quoted
4596 * within double quotes by preceding it with a backslash."
4597 * NB: in (unquoted) heredoc, above does not apply to ",
4598 * therefore we check for it by "next == dquote_end" cond.
4600 if (next == dquote_end || strchr("$`\\\n", next)) {
4601 ch = i_getch(input); /* eat next */
4603 goto again; /* skip \<newline> */
4604 } /* else: ch remains == '\\', and we double it below: */
4605 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4606 nommu_addchr(as_string, ch);
4610 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4611 debug_printf_parse("encode_string return 0: "
4612 "parse_dollar returned 0 (error)\n");
4617 #if ENABLE_HUSH_TICK
4619 //unsigned pos = dest->length;
4620 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4621 o_addchr(dest, 0x80 | '`');
4622 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4623 return 0; /* error */
4624 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4625 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4629 o_addQchr(dest, ch);
4635 * Scan input until EOF or end_trigger char.
4636 * Return a list of pipes to execute, or NULL on EOF
4637 * or if end_trigger character is met.
4638 * On syntax error, exit if shell is not interactive,
4639 * reset parsing machinery and start parsing anew,
4640 * or return ERR_PTR.
4642 static struct pipe *parse_stream(char **pstring,
4643 struct in_str *input,
4646 struct parse_context ctx;
4647 o_string dest = NULL_O_STRING;
4650 /* Single-quote triggers a bypass of the main loop until its mate is
4651 * found. When recursing, quote state is passed in via dest->o_expflags.
4653 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4654 end_trigger ? end_trigger : 'X');
4657 /* If very first arg is "" or '', dest.data may end up NULL.
4658 * Preventing this: */
4659 o_addchr(&dest, '\0');
4662 /* We used to separate words on $IFS here. This was wrong.
4663 * $IFS is used only for word splitting when $var is expanded,
4664 * here we should use blank chars as separators, not $IFS
4667 if (MAYBE_ASSIGNMENT != 0)
4668 dest.o_assignment = MAYBE_ASSIGNMENT;
4669 initialize_context(&ctx);
4672 const char *is_blank;
4673 const char *is_special;
4677 redir_type redir_style;
4679 ch = i_getch(input);
4680 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4681 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4686 syntax_error_unterm_str("here document");
4689 if (end_trigger == ')') {
4690 syntax_error_unterm_ch('(');
4693 if (end_trigger == '}') {
4694 syntax_error_unterm_ch('{');
4698 if (done_word(&dest, &ctx)) {
4702 done_pipe(&ctx, PIPE_SEQ);
4704 /* If we got nothing... */
4705 /* (this makes bare "&" cmd a no-op.
4706 * bash says: "syntax error near unexpected token '&'") */
4707 if (pi->num_cmds == 0
4708 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4714 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4716 *pstring = ctx.as_string.data;
4718 o_free_unsafe(&ctx.as_string);
4721 debug_printf_parse("parse_stream return %p\n", pi);
4724 nommu_addchr(&ctx.as_string, ch);
4728 next = i_peek(input);
4730 is_special = "{}<>;&|()#'" /* special outside of "str" */
4731 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4732 /* Are { and } special here? */
4733 if (ctx.command->argv /* word [word]{... - non-special */
4734 || dest.length /* word{... - non-special */
4735 || dest.has_quoted_part /* ""{... - non-special */
4736 || (next != ';' /* }; - special */
4737 && next != ')' /* }) - special */
4738 && next != '(' /* {( - special */
4739 && next != '&' /* }& and }&& ... - special */
4740 && next != '|' /* }|| ... - special */
4741 && !strchr(defifs, next) /* {word - non-special */
4744 /* They are not special, skip "{}" */
4747 is_special = strchr(is_special, ch);
4748 is_blank = strchr(defifs, ch);
4750 if (!is_special && !is_blank) { /* ordinary char */
4752 o_addQchr(&dest, ch);
4753 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4754 || dest.o_assignment == WORD_IS_KEYWORD)
4756 && is_well_formed_var_name(dest.data, '=')
4758 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4759 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4765 if (done_word(&dest, &ctx)) {
4769 /* Is this a case when newline is simply ignored?
4771 * "cmd | <newline> cmd ..."
4772 * "case ... in <newline> word) ..."
4774 if (IS_NULL_CMD(ctx.command)
4775 && dest.length == 0 && !dest.has_quoted_part
4777 /* This newline can be ignored. But...
4778 * Without check #1, interactive shell
4779 * ignores even bare <newline>,
4780 * and shows the continuation prompt:
4781 * ps1_prompt$ <enter>
4782 * ps2> _ <=== wrong, should be ps1
4783 * Without check #2, "cmd & <newline>"
4784 * is similarly mistreated.
4785 * (BTW, this makes "cmd & cmd"
4786 * and "cmd && cmd" non-orthogonal.
4787 * Really, ask yourself, why
4788 * "cmd && <newline>" doesn't start
4789 * cmd but waits for more input?
4792 struct pipe *pi = ctx.list_head;
4793 if (pi->num_cmds != 0 /* check #1 */
4794 && pi->followup != PIPE_BG /* check #2 */
4799 /* Treat newline as a command separator. */
4800 done_pipe(&ctx, PIPE_SEQ);
4801 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4803 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4808 dest.o_assignment = MAYBE_ASSIGNMENT;
4809 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4811 /* note: if (is_blank) continue;
4812 * will still trigger for us */
4816 /* "cmd}" or "cmd }..." without semicolon or &:
4817 * } is an ordinary char in this case, even inside { cmd; }
4818 * Pathological example: { ""}; } should exec "}" cmd
4821 if (dest.length != 0 /* word} */
4822 || dest.has_quoted_part /* ""} */
4826 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4827 /* Generally, there should be semicolon: "cmd; }"
4828 * However, bash allows to omit it if "cmd" is
4829 * a group. Examples:
4832 * { echo 0 >&2 | { echo 1; } }
4833 * { while false; do :; done }
4834 * { case a in b) ;; esac }
4836 if (ctx.command->group)
4840 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4841 /* Can't be an end of {cmd}, skip the check */
4842 goto skip_end_trigger;
4843 /* else: } does terminate a group */
4846 if (end_trigger && end_trigger == ch
4847 && (ch != ';' || heredoc_cnt == 0)
4848 #if ENABLE_HUSH_CASE
4850 || ctx.ctx_res_w != RES_MATCH
4851 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4856 /* This is technically valid:
4857 * { cat <<HERE; }; echo Ok
4861 * but we don't support this.
4862 * We require heredoc to be in enclosing {}/(),
4865 syntax_error_unterm_str("here document");
4868 if (done_word(&dest, &ctx)) {
4871 done_pipe(&ctx, PIPE_SEQ);
4872 dest.o_assignment = MAYBE_ASSIGNMENT;
4873 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4874 /* Do we sit outside of any if's, loops or case's? */
4876 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4880 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4882 *pstring = ctx.as_string.data;
4884 o_free_unsafe(&ctx.as_string);
4887 debug_printf_parse("parse_stream return %p: "
4888 "end_trigger char found\n",
4890 return ctx.list_head;
4897 /* Catch <, > before deciding whether this word is
4898 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4901 redir_fd = redirect_opt_num(&dest);
4902 if (done_word(&dest, &ctx)) {
4905 redir_style = REDIRECT_OVERWRITE;
4907 redir_style = REDIRECT_APPEND;
4908 ch = i_getch(input);
4909 nommu_addchr(&ctx.as_string, ch);
4912 else if (next == '(') {
4913 syntax_error(">(process) not supported");
4917 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4919 continue; /* back to top of while (1) */
4921 redir_fd = redirect_opt_num(&dest);
4922 if (done_word(&dest, &ctx)) {
4925 redir_style = REDIRECT_INPUT;
4927 redir_style = REDIRECT_HEREDOC;
4929 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4930 ch = i_getch(input);
4931 nommu_addchr(&ctx.as_string, ch);
4932 } else if (next == '>') {
4933 redir_style = REDIRECT_IO;
4934 ch = i_getch(input);
4935 nommu_addchr(&ctx.as_string, ch);
4938 else if (next == '(') {
4939 syntax_error("<(process) not supported");
4943 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4945 continue; /* back to top of while (1) */
4947 if (dest.length == 0 && !dest.has_quoted_part) {
4948 /* skip "#comment" */
4951 if (ch == EOF || ch == '\n')
4954 /* note: we do not add it to &ctx.as_string */
4956 nommu_addchr(&ctx.as_string, '\n');
4957 continue; /* back to top of while (1) */
4962 /* It's "\<newline>" */
4964 /* Remove trailing '\' from ctx.as_string */
4965 ctx.as_string.data[--ctx.as_string.length] = '\0';
4967 ch = i_getch(input); /* eat it */
4968 continue; /* back to top of while (1) */
4973 if (dest.o_assignment == MAYBE_ASSIGNMENT
4974 /* check that we are not in word in "a=1 2>word b=1": */
4975 && !ctx.pending_redirect
4977 /* ch is a special char and thus this word
4978 * cannot be an assignment */
4979 dest.o_assignment = NOT_ASSIGNMENT;
4980 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4983 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4986 case '#': /* non-comment #: "echo a#b" etc */
4987 o_addQchr(&dest, ch);
4991 syntax_error("\\<eof>");
4994 ch = i_getch(input);
4995 /* note: ch != '\n' (that case does not reach this place) */
4996 o_addchr(&dest, '\\');
4997 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4998 o_addchr(&dest, ch);
4999 nommu_addchr(&ctx.as_string, ch);
5000 /* Example: echo Hello \2>file
5001 * we need to know that word 2 is quoted */
5002 dest.has_quoted_part = 1;
5005 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5006 debug_printf_parse("parse_stream parse error: "
5007 "parse_dollar returned 0 (error)\n");
5012 dest.has_quoted_part = 1;
5013 if (next == '\'' && !ctx.pending_redirect) {
5014 insert_empty_quoted_str_marker:
5015 nommu_addchr(&ctx.as_string, next);
5016 i_getch(input); /* eat second ' */
5017 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5018 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5021 ch = i_getch(input);
5023 syntax_error_unterm_ch('\'');
5026 nommu_addchr(&ctx.as_string, ch);
5029 o_addqchr(&dest, ch);
5034 dest.has_quoted_part = 1;
5035 if (next == '"' && !ctx.pending_redirect)
5036 goto insert_empty_quoted_str_marker;
5037 if (dest.o_assignment == NOT_ASSIGNMENT)
5038 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5039 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5041 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5043 #if ENABLE_HUSH_TICK
5045 USE_FOR_NOMMU(unsigned pos;)
5047 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5048 o_addchr(&dest, '`');
5049 USE_FOR_NOMMU(pos = dest.length;)
5050 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5053 o_addstr(&ctx.as_string, dest.data + pos);
5054 o_addchr(&ctx.as_string, '`');
5056 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5057 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5062 #if ENABLE_HUSH_CASE
5065 if (done_word(&dest, &ctx)) {
5068 done_pipe(&ctx, PIPE_SEQ);
5069 #if ENABLE_HUSH_CASE
5070 /* Eat multiple semicolons, detect
5071 * whether it means something special */
5076 ch = i_getch(input);
5077 nommu_addchr(&ctx.as_string, ch);
5078 if (ctx.ctx_res_w == RES_CASE_BODY) {
5079 ctx.ctx_dsemicolon = 1;
5080 ctx.ctx_res_w = RES_MATCH;
5086 /* We just finished a cmd. New one may start
5087 * with an assignment */
5088 dest.o_assignment = MAYBE_ASSIGNMENT;
5089 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5092 if (done_word(&dest, &ctx)) {
5096 ch = i_getch(input);
5097 nommu_addchr(&ctx.as_string, ch);
5098 done_pipe(&ctx, PIPE_AND);
5100 done_pipe(&ctx, PIPE_BG);
5104 if (done_word(&dest, &ctx)) {
5107 #if ENABLE_HUSH_CASE
5108 if (ctx.ctx_res_w == RES_MATCH)
5109 break; /* we are in case's "word | word)" */
5111 if (next == '|') { /* || */
5112 ch = i_getch(input);
5113 nommu_addchr(&ctx.as_string, ch);
5114 done_pipe(&ctx, PIPE_OR);
5116 /* we could pick up a file descriptor choice here
5117 * with redirect_opt_num(), but bash doesn't do it.
5118 * "echo foo 2| cat" yields "foo 2". */
5123 #if ENABLE_HUSH_CASE
5124 /* "case... in [(]word)..." - skip '(' */
5125 if (ctx.ctx_res_w == RES_MATCH
5126 && ctx.command->argv == NULL /* not (word|(... */
5127 && dest.length == 0 /* not word(... */
5128 && dest.has_quoted_part == 0 /* not ""(... */
5134 if (parse_group(&dest, &ctx, input, ch) != 0) {
5139 #if ENABLE_HUSH_CASE
5140 if (ctx.ctx_res_w == RES_MATCH)
5144 /* proper use of this character is caught by end_trigger:
5145 * if we see {, we call parse_group(..., end_trigger='}')
5146 * and it will match } earlier (not here). */
5147 syntax_error_unexpected_ch(ch);
5148 G.last_exitcode = 2;
5152 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5157 G.last_exitcode = 1;
5160 struct parse_context *pctx;
5161 IF_HAS_KEYWORDS(struct parse_context *p2;)
5163 /* Clean up allocated tree.
5164 * Sample for finding leaks on syntax error recovery path.
5165 * Run it from interactive shell, watch pmap `pidof hush`.
5166 * while if false; then false; fi; do break; fi
5167 * Samples to catch leaks at execution:
5168 * while if (true | { true;}); then echo ok; fi; do break; done
5169 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5173 /* Update pipe/command counts,
5174 * otherwise freeing may miss some */
5175 done_pipe(pctx, PIPE_SEQ);
5176 debug_printf_clean("freeing list %p from ctx %p\n",
5177 pctx->list_head, pctx);
5178 debug_print_tree(pctx->list_head, 0);
5179 free_pipe_list(pctx->list_head);
5180 debug_printf_clean("freed list %p\n", pctx->list_head);
5182 o_free_unsafe(&pctx->as_string);
5184 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5188 IF_HAS_KEYWORDS(pctx = p2;)
5189 } while (HAS_KEYWORDS && pctx);
5202 /*** Execution routines ***/
5204 /* Expansion can recurse, need forward decls: */
5205 #if !BASH_PATTERN_SUBST
5206 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5207 #define expand_string_to_string(str, do_unbackslash) \
5208 expand_string_to_string(str)
5210 static char *expand_string_to_string(const char *str, int do_unbackslash);
5211 #if ENABLE_HUSH_TICK
5212 static int process_command_subs(o_string *dest, const char *s);
5215 /* expand_strvec_to_strvec() takes a list of strings, expands
5216 * all variable references within and returns a pointer to
5217 * a list of expanded strings, possibly with larger number
5218 * of strings. (Think VAR="a b"; echo $VAR).
5219 * This new list is allocated as a single malloc block.
5220 * NULL-terminated list of char* pointers is at the beginning of it,
5221 * followed by strings themselves.
5222 * Caller can deallocate entire list by single free(list). */
5224 /* A horde of its helpers come first: */
5226 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5228 while (--len >= 0) {
5231 #if ENABLE_HUSH_BRACE_EXPANSION
5232 if (c == '{' || c == '}') {
5233 /* { -> \{, } -> \} */
5235 /* And now we want to add { or } and continue:
5238 * luckily, just falling through achieves this.
5244 /* \z -> \\\z; \<eol> -> \\<eol> */
5249 o_addchr(o, *str++);
5255 /* Store given string, finalizing the word and starting new one whenever
5256 * we encounter IFS char(s). This is used for expanding variable values.
5257 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5258 * Return in *ended_with_ifs:
5259 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5261 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5263 int last_is_ifs = 0;
5268 if (!*str) /* EOL - do not finalize word */
5270 word_len = strcspn(str, G.ifs);
5272 /* We have WORD_LEN leading non-IFS chars */
5273 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5274 o_addblock(output, str, word_len);
5276 /* Protect backslashes against globbing up :)
5277 * Example: "v='\*'; echo b$v" prints "b\*"
5278 * (and does not try to glob on "*")
5280 o_addblock_duplicate_backslash(output, str, word_len);
5281 /*/ Why can't we do it easier? */
5282 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5283 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5287 if (!*str) /* EOL - do not finalize word */
5291 /* We know str here points to at least one IFS char */
5293 str += strspn(str, G.ifs); /* skip IFS chars */
5294 if (!*str) /* EOL - do not finalize word */
5297 /* Start new word... but not always! */
5298 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5299 if (output->has_quoted_part
5300 /* Case "v=' a'; echo $v":
5301 * here nothing precedes the space in $v expansion,
5302 * therefore we should not finish the word
5303 * (IOW: if there *is* word to finalize, only then do it):
5305 || (n > 0 && output->data[output->length - 1])
5307 o_addchr(output, '\0');
5308 debug_print_list("expand_on_ifs", output, n);
5309 n = o_save_ptr(output, n);
5314 *ended_with_ifs = last_is_ifs;
5315 debug_print_list("expand_on_ifs[1]", output, n);
5319 /* Helper to expand $((...)) and heredoc body. These act as if
5320 * they are in double quotes, with the exception that they are not :).
5321 * Just the rules are similar: "expand only $var and `cmd`"
5323 * Returns malloced string.
5324 * As an optimization, we return NULL if expansion is not needed.
5326 #if !BASH_PATTERN_SUBST
5327 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5328 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5329 encode_then_expand_string(str)
5331 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5334 struct in_str input;
5335 o_string dest = NULL_O_STRING;
5337 if (!strchr(str, '$')
5338 && !strchr(str, '\\')
5339 #if ENABLE_HUSH_TICK
5340 && !strchr(str, '`')
5346 /* We need to expand. Example:
5347 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5349 setup_string_in_str(&input, str);
5350 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5351 //TODO: error check (encode_string returns 0 on error)?
5352 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5353 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5354 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5355 o_free_unsafe(&dest);
5359 #if ENABLE_FEATURE_SH_MATH
5360 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5362 arith_state_t math_state;
5366 math_state.lookupvar = get_local_var_value;
5367 math_state.setvar = set_local_var_from_halves;
5368 //math_state.endofname = endofname;
5369 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5370 res = arith(&math_state, exp_str ? exp_str : arg);
5373 *errmsg_p = math_state.errmsg;
5374 if (math_state.errmsg)
5375 die_if_script(math_state.errmsg);
5380 #if BASH_PATTERN_SUBST
5381 /* ${var/[/]pattern[/repl]} helpers */
5382 static char *strstr_pattern(char *val, const char *pattern, int *size)
5385 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5386 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5393 /* Optimization: if "*pat" did not match the start of "string",
5394 * we know that "tring", "ring" etc will not match too:
5396 if (pattern[0] == '*')
5401 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5403 char *result = NULL;
5404 unsigned res_len = 0;
5405 unsigned repl_len = strlen(repl);
5409 char *s = strstr_pattern(val, pattern, &size);
5413 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5414 memcpy(result + res_len, val, s - val);
5416 strcpy(result + res_len, repl);
5417 res_len += repl_len;
5418 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5424 if (val[0] && result) {
5425 result = xrealloc(result, res_len + strlen(val) + 1);
5426 strcpy(result + res_len, val);
5427 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5429 debug_printf_varexp("result:'%s'\n", result);
5432 #endif /* BASH_PATTERN_SUBST */
5435 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5437 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5439 const char *val = NULL;
5440 char *to_be_freed = NULL;
5445 char exp_save = exp_save; /* for compiler */
5446 char *exp_saveptr; /* points to expansion operator */
5447 char *exp_word = exp_word; /* for compiler */
5450 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5452 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5454 first_char = arg[0] = arg0 & 0x7f;
5457 if (first_char == '#' /* ${#... */
5458 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5460 /* It must be length operator: ${#var} */
5464 /* Maybe handle parameter expansion */
5465 if (exp_saveptr /* if 2nd char is one of expansion operators */
5466 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5468 /* ${?:0}, ${#[:]%0} etc */
5469 exp_saveptr = var + 1;
5471 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5472 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5474 exp_op = exp_save = *exp_saveptr;
5476 exp_word = exp_saveptr + 1;
5477 if (exp_op == ':') {
5478 exp_op = *exp_word++;
5479 //TODO: try ${var:} and ${var:bogus} in non-bash config
5481 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5483 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5488 *exp_saveptr = '\0';
5489 } /* else: it's not an expansion op, but bare ${var} */
5492 /* Look up the variable in question */
5493 if (isdigit(var[0])) {
5494 /* parse_dollar should have vetted var for us */
5495 int n = xatoi_positive(var);
5496 if (n < G.global_argc)
5497 val = G.global_argv[n];
5498 /* else val remains NULL: $N with too big N */
5502 val = utoa(G.root_pid);
5504 case '!': /* bg pid */
5505 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5507 case '?': /* exitcode */
5508 val = utoa(G.last_exitcode);
5510 case '#': /* argc */
5511 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5514 val = get_local_var_value(var);
5518 /* Handle any expansions */
5519 if (exp_op == 'L') {
5520 reinit_unicode_for_hush();
5521 debug_printf_expand("expand: length(%s)=", val);
5522 val = utoa(val ? unicode_strlen(val) : 0);
5523 debug_printf_expand("%s\n", val);
5524 } else if (exp_op) {
5525 if (exp_op == '%' || exp_op == '#') {
5526 /* Standard-mandated substring removal ops:
5527 * ${parameter%word} - remove smallest suffix pattern
5528 * ${parameter%%word} - remove largest suffix pattern
5529 * ${parameter#word} - remove smallest prefix pattern
5530 * ${parameter##word} - remove largest prefix pattern
5532 * Word is expanded to produce a glob pattern.
5533 * Then var's value is matched to it and matching part removed.
5535 if (val && val[0]) {
5539 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5540 if (exp_op == *exp_word) /* ## or %% */
5542 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5544 exp_word = exp_exp_word;
5545 /* HACK ALERT. We depend here on the fact that
5546 * G.global_argv and results of utoa and get_local_var_value
5547 * are actually in writable memory:
5548 * scan_and_match momentarily stores NULs there. */
5550 loc = scan_and_match(t, exp_word, scan_flags);
5551 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5552 // exp_op, t, exp_word, loc);
5554 if (loc) { /* match was found */
5555 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5556 val = loc; /* take right part */
5558 val = to_be_freed = xstrndup(val, loc - val); /* left */
5562 #if BASH_PATTERN_SUBST
5563 else if (exp_op == '/' || exp_op == '\\') {
5564 /* It's ${var/[/]pattern[/repl]} thing.
5565 * Note that in encoded form it has TWO parts:
5566 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5567 * and if // is used, it is encoded as \:
5568 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5570 /* Empty variable always gives nothing: */
5571 // "v=''; echo ${v/*/w}" prints "", not "w"
5572 if (val && val[0]) {
5573 /* pattern uses non-standard expansion.
5574 * repl should be unbackslashed and globbed
5575 * by the usual expansion rules:
5577 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5578 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5579 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5580 * v='a bz'; echo ${v/a*z/\z} prints "z"
5581 * (note that a*z _pattern_ is never globbed!)
5583 char *pattern, *repl, *t;
5584 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5586 pattern = xstrdup(exp_word);
5587 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5588 *p++ = SPECIAL_VAR_SYMBOL;
5590 p = strchr(p, SPECIAL_VAR_SYMBOL);
5592 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5593 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5594 /* HACK ALERT. We depend here on the fact that
5595 * G.global_argv and results of utoa and get_local_var_value
5596 * are actually in writable memory:
5597 * replace_pattern momentarily stores NULs there. */
5599 to_be_freed = replace_pattern(t,
5601 (repl ? repl : exp_word),
5603 if (to_be_freed) /* at least one replace happened */
5609 #endif /* BASH_PATTERN_SUBST */
5610 else if (exp_op == ':') {
5611 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5612 /* It's ${var:N[:M]} bashism.
5613 * Note that in encoded form it has TWO parts:
5614 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5619 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5622 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5623 *p++ = SPECIAL_VAR_SYMBOL;
5625 p = strchr(p, SPECIAL_VAR_SYMBOL);
5627 len = expand_and_evaluate_arith(exp_word, &errmsg);
5630 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5631 if (len >= 0) { /* bash compat: len < 0 is illegal */
5632 if (beg < 0) /* bash compat */
5634 debug_printf_varexp("from val:'%s'\n", val);
5635 if (len == 0 || !val || beg >= strlen(val)) {
5639 /* Paranoia. What if user entered 9999999999999
5640 * which fits in arith_t but not int? */
5643 val = to_be_freed = xstrndup(val + beg, len);
5645 debug_printf_varexp("val:'%s'\n", val);
5647 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5649 die_if_script("malformed ${%s:...}", var);
5652 } else { /* one of "-=+?" */
5653 /* Standard-mandated substitution ops:
5654 * ${var?word} - indicate error if unset
5655 * If var is unset, word (or a message indicating it is unset
5656 * if word is null) is written to standard error
5657 * and the shell exits with a non-zero exit status.
5658 * Otherwise, the value of var is substituted.
5659 * ${var-word} - use default value
5660 * If var is unset, word is substituted.
5661 * ${var=word} - assign and use default value
5662 * If var is unset, word is assigned to var.
5663 * In all cases, final value of var is substituted.
5664 * ${var+word} - use alternative value
5665 * If var is unset, null is substituted.
5666 * Otherwise, word is substituted.
5668 * Word is subjected to tilde expansion, parameter expansion,
5669 * command substitution, and arithmetic expansion.
5670 * If word is not needed, it is not expanded.
5672 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5673 * but also treat null var as if it is unset.
5675 int use_word = (!val || ((exp_save == ':') && !val[0]));
5677 use_word = !use_word;
5678 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5679 (exp_save == ':') ? "true" : "false", use_word);
5681 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5683 exp_word = to_be_freed;
5684 if (exp_op == '?') {
5685 /* mimic bash message */
5686 die_if_script("%s: %s",
5688 exp_word[0] ? exp_word : "parameter null or not set"
5690 //TODO: how interactive bash aborts expansion mid-command?
5695 if (exp_op == '=') {
5696 /* ${var=[word]} or ${var:=[word]} */
5697 if (isdigit(var[0]) || var[0] == '#') {
5698 /* mimic bash message */
5699 die_if_script("$%s: cannot assign in this way", var);
5702 char *new_var = xasprintf("%s=%s", var, val);
5703 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5707 } /* one of "-=+?" */
5709 *exp_saveptr = exp_save;
5715 *to_be_freed_pp = to_be_freed;
5719 /* Expand all variable references in given string, adding words to list[]
5720 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5721 * to be filled). This routine is extremely tricky: has to deal with
5722 * variables/parameters with whitespace, $* and $@, and constructs like
5723 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5724 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5726 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5727 * expansion of right-hand side of assignment == 1-element expand.
5729 char cant_be_null = 0; /* only bit 0x80 matters */
5730 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5733 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5734 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5735 debug_print_list("expand_vars_to_list", output, n);
5736 n = o_save_ptr(output, n);
5737 debug_print_list("expand_vars_to_list[0]", output, n);
5739 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5741 char *to_be_freed = NULL;
5742 const char *val = NULL;
5743 #if ENABLE_HUSH_TICK
5744 o_string subst_result = NULL_O_STRING;
5746 #if ENABLE_FEATURE_SH_MATH
5747 char arith_buf[sizeof(arith_t)*3 + 2];
5751 o_addchr(output, '\0');
5752 n = o_save_ptr(output, n);
5756 o_addblock(output, arg, p - arg);
5757 debug_print_list("expand_vars_to_list[1]", output, n);
5759 p = strchr(p, SPECIAL_VAR_SYMBOL);
5761 /* Fetch special var name (if it is indeed one of them)
5762 * and quote bit, force the bit on if singleword expansion -
5763 * important for not getting v=$@ expand to many words. */
5764 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5766 /* Is this variable quoted and thus expansion can't be null?
5767 * "$@" is special. Even if quoted, it can still
5768 * expand to nothing (not even an empty string),
5769 * thus it is excluded. */
5770 if ((first_ch & 0x7f) != '@')
5771 cant_be_null |= first_ch;
5773 switch (first_ch & 0x7f) {
5774 /* Highest bit in first_ch indicates that var is double-quoted */
5778 if (!G.global_argv[1])
5781 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5782 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5783 while (G.global_argv[i]) {
5784 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5785 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5786 if (G.global_argv[i++][0] && G.global_argv[i]) {
5787 /* this argv[] is not empty and not last:
5788 * put terminating NUL, start new word */
5789 o_addchr(output, '\0');
5790 debug_print_list("expand_vars_to_list[2]", output, n);
5791 n = o_save_ptr(output, n);
5792 debug_print_list("expand_vars_to_list[3]", output, n);
5796 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5797 * and in this case should treat it like '$*' - see 'else...' below */
5798 if (first_ch == ('@'|0x80) /* quoted $@ */
5799 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5802 o_addQstr(output, G.global_argv[i]);
5803 if (++i >= G.global_argc)
5805 o_addchr(output, '\0');
5806 debug_print_list("expand_vars_to_list[4]", output, n);
5807 n = o_save_ptr(output, n);
5809 } else { /* quoted $* (or v="$@" case): add as one word */
5811 o_addQstr(output, G.global_argv[i]);
5812 if (!G.global_argv[++i])
5815 o_addchr(output, G.ifs[0]);
5817 output->has_quoted_part = 1;
5821 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5822 /* "Empty variable", used to make "" etc to not disappear */
5823 output->has_quoted_part = 1;
5825 cant_be_null = 0x80;
5827 #if ENABLE_HUSH_TICK
5828 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5829 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5831 /* Can't just stuff it into output o_string,
5832 * expanded result may need to be globbed
5834 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5835 G.last_exitcode = process_command_subs(&subst_result, arg);
5836 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5837 val = subst_result.data;
5840 #if ENABLE_FEATURE_SH_MATH
5841 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5844 arg++; /* skip '+' */
5845 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5846 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5847 res = expand_and_evaluate_arith(arg, NULL);
5848 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5849 sprintf(arith_buf, ARITH_FMT, res);
5855 val = expand_one_var(&to_be_freed, arg, &p);
5856 IF_HUSH_TICK(store_val:)
5857 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5858 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5859 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5860 if (val && val[0]) {
5861 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5864 } else { /* quoted $VAR, val will be appended below */
5865 output->has_quoted_part = 1;
5866 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5867 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5870 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5872 if (val && val[0]) {
5873 o_addQstr(output, val);
5877 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5878 * Do the check to avoid writing to a const string. */
5879 if (*p != SPECIAL_VAR_SYMBOL)
5880 *p = SPECIAL_VAR_SYMBOL;
5882 #if ENABLE_HUSH_TICK
5883 o_free(&subst_result);
5886 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5890 o_addchr(output, '\0');
5891 n = o_save_ptr(output, n);
5893 debug_print_list("expand_vars_to_list[a]", output, n);
5894 /* this part is literal, and it was already pre-quoted
5895 * if needed (much earlier), do not use o_addQstr here! */
5896 o_addstr_with_NUL(output, arg);
5897 debug_print_list("expand_vars_to_list[b]", output, n);
5898 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5899 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5902 /* allow to reuse list[n] later without re-growth */
5903 output->has_empty_slot = 1;
5905 o_addchr(output, '\0');
5911 static char **expand_variables(char **argv, unsigned expflags)
5915 o_string output = NULL_O_STRING;
5917 output.o_expflags = expflags;
5921 n = expand_vars_to_list(&output, n, *argv);
5924 debug_print_list("expand_variables", &output, n);
5926 /* output.data (malloced in one block) gets returned in "list" */
5927 list = o_finalize_list(&output, n);
5928 debug_print_strings("expand_variables[1]", list);
5932 static char **expand_strvec_to_strvec(char **argv)
5934 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5938 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5940 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5944 /* Used for expansion of right hand of assignments,
5945 * $((...)), heredocs, variable espansion parts.
5947 * NB: should NOT do globbing!
5948 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5950 static char *expand_string_to_string(const char *str, int do_unbackslash)
5952 #if !BASH_PATTERN_SUBST
5953 const int do_unbackslash = 1;
5955 char *argv[2], **list;
5957 debug_printf_expand("string_to_string<='%s'\n", str);
5958 /* This is generally an optimization, but it also
5959 * handles "", which otherwise trips over !list[0] check below.
5960 * (is this ever happens that we actually get str="" here?)
5962 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5963 //TODO: Can use on strings with \ too, just unbackslash() them?
5964 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5965 return xstrdup(str);
5968 argv[0] = (char*)str;
5970 list = expand_variables(argv, do_unbackslash
5971 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5972 : EXP_FLAG_SINGLEWORD
5975 if (!list[0] || list[1])
5976 bb_error_msg_and_die("BUG in varexp2");
5977 /* actually, just move string 2*sizeof(char*) bytes back */
5978 overlapping_strcpy((char*)list, list[0]);
5980 unbackslash((char*)list);
5981 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5985 /* Used for "eval" builtin */
5986 static char* expand_strvec_to_string(char **argv)
5990 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5991 /* Convert all NULs to spaces */
5996 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5997 bb_error_msg_and_die("BUG in varexp3");
5998 /* bash uses ' ' regardless of $IFS contents */
6003 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6004 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6008 static char **expand_assignments(char **argv, int count)
6013 G.expanded_assignments = p = NULL;
6014 /* Expand assignments into one string each */
6015 for (i = 0; i < count; i++) {
6016 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6018 G.expanded_assignments = NULL;
6023 static void switch_off_special_sigs(unsigned mask)
6026 while ((mask >>= 1) != 0) {
6030 #if ENABLE_HUSH_TRAP
6032 if (G_traps[sig] && !G_traps[sig][0])
6033 /* trap is '', has to remain SIG_IGN */
6036 G_traps[sig] = NULL;
6039 /* We are here only if no trap or trap was not '' */
6040 install_sighandler(sig, SIG_DFL);
6046 void re_execute_shell(char ***to_free, const char *s,
6047 char *g_argv0, char **g_argv,
6048 char **builtin_argv) NORETURN;
6050 static void reset_traps_to_defaults(void)
6052 /* This function is always called in a child shell
6053 * after fork (not vfork, NOMMU doesn't use this function).
6055 IF_HUSH_TRAP(unsigned sig;)
6058 /* Child shells are not interactive.
6059 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6060 * Testcase: (while :; do :; done) + ^Z should background.
6061 * Same goes for SIGTERM, SIGHUP, SIGINT.
6063 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6064 if (!G_traps && !mask)
6065 return; /* already no traps and no special sigs */
6067 /* Switch off special sigs */
6068 switch_off_special_sigs(mask);
6069 # if ENABLE_HUSH_JOB
6070 G_fatal_sig_mask = 0;
6072 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6073 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6074 * remain set in G.special_sig_mask */
6076 # if ENABLE_HUSH_TRAP
6080 /* Reset all sigs to default except ones with empty traps */
6081 for (sig = 0; sig < NSIG; sig++) {
6083 continue; /* no trap: nothing to do */
6084 if (!G_traps[sig][0])
6085 continue; /* empty trap: has to remain SIG_IGN */
6086 /* sig has non-empty trap, reset it: */
6088 G_traps[sig] = NULL;
6089 /* There is no signal for trap 0 (EXIT) */
6092 install_sighandler(sig, pick_sighandler(sig));
6099 static void re_execute_shell(char ***to_free, const char *s,
6100 char *g_argv0, char **g_argv,
6101 char **builtin_argv) NORETURN;
6102 static void re_execute_shell(char ***to_free, const char *s,
6103 char *g_argv0, char **g_argv,
6104 char **builtin_argv)
6106 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6107 /* delims + 2 * (number of bytes in printed hex numbers) */
6108 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6109 char *heredoc_argv[4];
6110 struct variable *cur;
6111 # if ENABLE_HUSH_FUNCTIONS
6112 struct function *funcp;
6116 unsigned long long empty_trap_mask;
6118 if (!g_argv0) { /* heredoc */
6119 argv = heredoc_argv;
6120 argv[0] = (char *) G.argv0_for_re_execing;
6121 argv[1] = (char *) "-<";
6122 argv[2] = (char *) s;
6124 pp = &argv[3]; /* used as pointer to empty environment */
6130 if (pp) while (*pp++)
6133 empty_trap_mask = 0;
6136 for (sig = 1; sig < NSIG; sig++) {
6137 if (G_traps[sig] && !G_traps[sig][0])
6138 empty_trap_mask |= 1LL << sig;
6142 sprintf(param_buf, NOMMU_HACK_FMT
6143 , (unsigned) G.root_pid
6144 , (unsigned) G.root_ppid
6145 , (unsigned) G.last_bg_pid
6146 , (unsigned) G.last_exitcode
6149 IF_HUSH_LOOPS(, G.depth_of_loop)
6151 # undef NOMMU_HACK_FMT
6152 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6153 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6156 for (cur = G.top_var; cur; cur = cur->next) {
6157 if (!cur->flg_export || cur->flg_read_only)
6160 # if ENABLE_HUSH_FUNCTIONS
6161 for (funcp = G.top_func; funcp; funcp = funcp->next)
6167 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6168 *pp++ = (char *) G.argv0_for_re_execing;
6170 for (cur = G.top_var; cur; cur = cur->next) {
6171 if (strcmp(cur->varstr, hush_version_str) == 0)
6173 if (cur->flg_read_only) {
6174 *pp++ = (char *) "-R";
6175 *pp++ = cur->varstr;
6176 } else if (!cur->flg_export) {
6177 *pp++ = (char *) "-V";
6178 *pp++ = cur->varstr;
6181 # if ENABLE_HUSH_FUNCTIONS
6182 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6183 *pp++ = (char *) "-F";
6184 *pp++ = funcp->name;
6185 *pp++ = funcp->body_as_string;
6188 /* We can pass activated traps here. Say, -Tnn:trap_string
6190 * However, POSIX says that subshells reset signals with traps
6192 * I tested bash-3.2 and it not only does that with true subshells
6193 * of the form ( list ), but with any forked children shells.
6194 * I set trap "echo W" WINCH; and then tried:
6196 * { echo 1; sleep 20; echo 2; } &
6197 * while true; do echo 1; sleep 20; echo 2; break; done &
6198 * true | { echo 1; sleep 20; echo 2; } | cat
6200 * In all these cases sending SIGWINCH to the child shell
6201 * did not run the trap. If I add trap "echo V" WINCH;
6202 * _inside_ group (just before echo 1), it works.
6204 * I conclude it means we don't need to pass active traps here.
6206 *pp++ = (char *) "-c";
6209 while (*++builtin_argv)
6210 *pp++ = *builtin_argv;
6211 *pp++ = (char *) "";
6216 /* *pp = NULL; - is already there */
6220 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6221 /* Don't propagate SIG_IGN to the child */
6222 if (SPECIAL_JOBSTOP_SIGS != 0)
6223 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6224 execve(bb_busybox_exec_path, argv, pp);
6225 /* Fallback. Useful for init=/bin/hush usage etc */
6226 if (argv[0][0] == '/')
6227 execve(argv[0], argv, pp);
6228 xfunc_error_retval = 127;
6229 bb_error_msg_and_die("can't re-execute the shell");
6231 #endif /* !BB_MMU */
6234 static int run_and_free_list(struct pipe *pi);
6236 /* Executing from string: eval, sh -c '...'
6237 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6238 * end_trigger controls how often we stop parsing
6239 * NUL: parse all, execute, return
6240 * ';': parse till ';' or newline, execute, repeat till EOF
6242 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6244 /* Why we need empty flag?
6245 * An obscure corner case "false; ``; echo $?":
6246 * empty command in `` should still set $? to 0.
6247 * But we can't just set $? to 0 at the start,
6248 * this breaks "false; echo `echo $?`" case.
6252 struct pipe *pipe_list;
6254 #if ENABLE_HUSH_INTERACTIVE
6255 if (end_trigger == ';')
6256 inp->promptmode = 0; /* PS1 */
6258 pipe_list = parse_stream(NULL, inp, end_trigger);
6259 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6260 /* If we are in "big" script
6261 * (not in `cmd` or something similar)...
6263 if (pipe_list == ERR_PTR && end_trigger == ';') {
6264 /* Discard cached input (rest of line) */
6265 int ch = inp->last_char;
6266 while (ch != EOF && ch != '\n') {
6267 //bb_error_msg("Discarded:'%c'", ch);
6272 /* This stream isn't empty */
6276 if (!pipe_list && empty)
6277 G.last_exitcode = 0;
6280 debug_print_tree(pipe_list, 0);
6281 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6282 run_and_free_list(pipe_list);
6284 if (G_flag_return_in_progress == 1)
6289 static void parse_and_run_string(const char *s)
6291 struct in_str input;
6292 setup_string_in_str(&input, s);
6293 parse_and_run_stream(&input, '\0');
6296 static void parse_and_run_file(FILE *f)
6298 struct in_str input;
6299 setup_file_in_str(&input, f);
6300 parse_and_run_stream(&input, ';');
6303 #if ENABLE_HUSH_TICK
6304 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6309 char **to_free = NULL;
6313 pid = BB_MMU ? xfork() : xvfork();
6314 if (pid == 0) { /* child */
6315 disable_restore_tty_pgrp_on_exit();
6316 /* Process substitution is not considered to be usual
6317 * 'command execution'.
6318 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6325 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6326 close(channel[0]); /* NB: close _first_, then move fd! */
6327 xmove_fd(channel[1], 1);
6328 /* Prevent it from trying to handle ctrl-z etc */
6329 IF_HUSH_JOB(G.run_list_level = 1;)
6330 # if ENABLE_HUSH_TRAP
6331 /* Awful hack for `trap` or $(trap).
6333 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6334 * contains an example where "trap" is executed in a subshell:
6336 * save_traps=$(trap)
6338 * eval "$save_traps"
6340 * Standard does not say that "trap" in subshell shall print
6341 * parent shell's traps. It only says that its output
6342 * must have suitable form, but then, in the above example
6343 * (which is not supposed to be normative), it implies that.
6345 * bash (and probably other shell) does implement it
6346 * (traps are reset to defaults, but "trap" still shows them),
6347 * but as a result, "trap" logic is hopelessly messed up:
6350 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6351 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6352 * # true | trap <--- trap is in subshell - no output (ditto)
6353 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6354 * trap -- 'echo Ho' SIGWINCH
6355 * # echo `(trap)` <--- in subshell in subshell - output
6356 * trap -- 'echo Ho' SIGWINCH
6357 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6358 * trap -- 'echo Ho' SIGWINCH
6360 * The rules when to forget and when to not forget traps
6361 * get really complex and nonsensical.
6363 * Our solution: ONLY bare $(trap) or `trap` is special.
6365 s = skip_whitespace(s);
6366 if (is_prefixed_with(s, "trap")
6367 && skip_whitespace(s + 4)[0] == '\0'
6369 static const char *const argv[] = { NULL, NULL };
6370 builtin_trap((char**)argv);
6371 fflush_all(); /* important */
6376 reset_traps_to_defaults();
6377 parse_and_run_string(s);
6378 _exit(G.last_exitcode);
6380 /* We re-execute after vfork on NOMMU. This makes this script safe:
6381 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6382 * huge=`cat BIG` # was blocking here forever
6385 re_execute_shell(&to_free,
6395 # if ENABLE_HUSH_FAST
6397 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6398 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6399 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6401 enable_restore_tty_pgrp_on_exit();
6406 return remember_FILE(xfdopen_for_read(channel[0]));
6409 /* Return code is exit status of the process that is run. */
6410 static int process_command_subs(o_string *dest, const char *s)
6413 struct in_str pipe_str;
6415 int status, ch, eol_cnt;
6417 fp = generate_stream_from_string(s, &pid);
6419 /* Now send results of command back into original context */
6420 setup_file_in_str(&pipe_str, fp);
6422 while ((ch = i_getch(&pipe_str)) != EOF) {
6428 o_addchr(dest, '\n');
6431 o_addQchr(dest, ch);
6434 debug_printf("done reading from `cmd` pipe, closing it\n");
6435 fclose_and_forget(fp);
6436 /* We need to extract exitcode. Test case
6437 * "true; echo `sleep 1; false` $?"
6439 safe_waitpid(pid, &status, 0);
6440 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6441 return WEXITSTATUS(status);
6443 #endif /* ENABLE_HUSH_TICK */
6446 static void setup_heredoc(struct redir_struct *redir)
6448 struct fd_pair pair;
6451 /* the _body_ of heredoc (misleading field name) */
6452 const char *heredoc = redir->rd_filename;
6459 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6460 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6464 len = strlen(heredoc);
6466 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6468 xmove_fd(pair.rd, redir->rd_fd);
6470 /* Try writing without forking. Newer kernels have
6471 * dynamically growing pipes. Must use non-blocking write! */
6474 written = write(pair.wr, heredoc, len);
6485 ndelay_off(pair.wr);
6487 /* Okay, pipe buffer was not big enough */
6488 /* Note: we must not create a stray child (bastard? :)
6489 * for the unsuspecting parent process. Child creates a grandchild
6490 * and exits before parent execs the process which consumes heredoc
6491 * (that exec happens after we return from this function) */
6498 disable_restore_tty_pgrp_on_exit();
6499 pid = BB_MMU ? xfork() : xvfork();
6503 close(redir->rd_fd); /* read side of the pipe */
6505 full_write(pair.wr, heredoc, len); /* may loop or block */
6508 /* Delegate blocking writes to another process */
6509 xmove_fd(pair.wr, STDOUT_FILENO);
6510 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6514 #if ENABLE_HUSH_FAST
6516 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6518 enable_restore_tty_pgrp_on_exit();
6524 wait(NULL); /* wait till child has died */
6527 /* fd: redirect wants this fd to be used (e.g. 3>file).
6528 * Move all conflicting internally used fds,
6529 * and remember them so that we can restore them later.
6531 static int save_fds_on_redirect(int fd, int squirrel[3])
6534 /* Handle redirects of fds 0,1,2 */
6536 /* If we collide with an already moved stdio fd... */
6537 if (fd == squirrel[0]) {
6538 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6541 if (fd == squirrel[1]) {
6542 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6545 if (fd == squirrel[2]) {
6546 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6549 /* If we are about to redirect stdio fd, and did not yet move it... */
6550 if (fd <= 2 && squirrel[fd] < 0) {
6551 /* We avoid taking stdio fds */
6552 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6553 if (squirrel[fd] < 0 && errno != EBADF)
6555 return 0; /* "we did not close fd" */
6559 #if ENABLE_HUSH_INTERACTIVE
6560 if (fd != 0 && fd == G.interactive_fd) {
6561 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6566 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6567 * (1) Redirect in a forked child. No need to save FILEs' fds,
6568 * we aren't going to use them anymore, ok to trash.
6569 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6570 * but how are we doing to use them?
6571 * "fileno(fd) = new_fd" can't be done.
6576 return save_FILEs_on_redirect(fd);
6579 static void restore_redirects(int squirrel[3])
6582 for (i = 0; i <= 2; i++) {
6585 /* We simply die on error */
6590 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6592 restore_redirected_FILEs();
6595 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6596 * and stderr if they are redirected. */
6597 static int setup_redirects(struct command *prog, int squirrel[])
6600 struct redir_struct *redir;
6602 for (redir = prog->redirects; redir; redir = redir->next) {
6603 if (redir->rd_type == REDIRECT_HEREDOC2) {
6604 /* "rd_fd<<HERE" case */
6605 save_fds_on_redirect(redir->rd_fd, squirrel);
6606 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6608 debug_printf_parse("set heredoc '%s'\n",
6609 redir->rd_filename);
6610 setup_heredoc(redir);
6614 if (redir->rd_dup == REDIRFD_TO_FILE) {
6615 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6617 if (redir->rd_filename == NULL) {
6620 * "cmd >" (no filename)
6621 * "cmd > <file" (2nd redirect starts too early)
6623 die_if_script("syntax error: %s", "invalid redirect");
6626 mode = redir_table[redir->rd_type].mode;
6627 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6628 openfd = open_or_warn(p, mode);
6631 /* Error message from open_or_warn can be lost
6632 * if stderr has been redirected, but bash
6633 * and ash both lose it as well
6634 * (though zsh doesn't!)
6639 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6640 openfd = redir->rd_dup;
6643 if (openfd != redir->rd_fd) {
6644 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6645 if (openfd == REDIRFD_CLOSE) {
6646 /* "rd_fd >&-" means "close me" */
6648 /* ^^^ optimization: saving may already
6649 * have closed it. If not... */
6650 close(redir->rd_fd);
6653 xdup2(openfd, redir->rd_fd);
6654 if (redir->rd_dup == REDIRFD_TO_FILE)
6655 /* "rd_fd > FILE" */
6657 /* else: "rd_fd > rd_dup" */
6664 static char *find_in_path(const char *arg)
6667 const char *PATH = get_local_var_value("PATH");
6673 const char *end = strchrnul(PATH, ':');
6674 int sz = end - PATH; /* must be int! */
6678 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6680 /* We have xxx::yyyy in $PATH,
6681 * it means "use current dir" */
6684 if (access(ret, F_OK) == 0)
6697 static const struct built_in_command *find_builtin_helper(const char *name,
6698 const struct built_in_command *x,
6699 const struct built_in_command *end)
6702 if (strcmp(name, x->b_cmd) != 0) {
6706 debug_printf_exec("found builtin '%s'\n", name);
6711 static const struct built_in_command *find_builtin1(const char *name)
6713 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6715 static const struct built_in_command *find_builtin(const char *name)
6717 const struct built_in_command *x = find_builtin1(name);
6720 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6723 #if ENABLE_HUSH_FUNCTIONS
6724 static struct function **find_function_slot(const char *name)
6726 struct function **funcpp = &G.top_func;
6728 if (strcmp(name, (*funcpp)->name) == 0) {
6731 funcpp = &(*funcpp)->next;
6736 static const struct function *find_function(const char *name)
6738 const struct function *funcp = *find_function_slot(name);
6740 debug_printf_exec("found function '%s'\n", name);
6744 /* Note: takes ownership on name ptr */
6745 static struct function *new_function(char *name)
6747 struct function **funcpp = find_function_slot(name);
6748 struct function *funcp = *funcpp;
6750 if (funcp != NULL) {
6751 struct command *cmd = funcp->parent_cmd;
6752 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6754 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6756 /* Note: if !funcp->body, do not free body_as_string!
6757 * This is a special case of "-F name body" function:
6758 * body_as_string was not malloced! */
6760 free_pipe_list(funcp->body);
6762 free(funcp->body_as_string);
6766 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6767 cmd->argv[0] = funcp->name;
6768 cmd->group = funcp->body;
6770 cmd->group_as_string = funcp->body_as_string;
6774 debug_printf_exec("remembering new function '%s'\n", name);
6775 funcp = *funcpp = xzalloc(sizeof(*funcp));
6776 /*funcp->next = NULL;*/
6783 # if ENABLE_HUSH_UNSET
6784 static void unset_func(const char *name)
6786 struct function **funcpp = find_function_slot(name);
6787 struct function *funcp = *funcpp;
6789 if (funcp != NULL) {
6790 debug_printf_exec("freeing function '%s'\n", funcp->name);
6791 *funcpp = funcp->next;
6792 /* funcp is unlinked now, deleting it.
6793 * Note: if !funcp->body, the function was created by
6794 * "-F name body", do not free ->body_as_string
6795 * and ->name as they were not malloced. */
6797 free_pipe_list(funcp->body);
6800 free(funcp->body_as_string);
6809 #define exec_function(to_free, funcp, argv) \
6810 exec_function(funcp, argv)
6812 static void exec_function(char ***to_free,
6813 const struct function *funcp,
6814 char **argv) NORETURN;
6815 static void exec_function(char ***to_free,
6816 const struct function *funcp,
6822 argv[0] = G.global_argv[0];
6823 G.global_argv = argv;
6827 /* On MMU, funcp->body is always non-NULL */
6828 n = run_list(funcp->body);
6832 re_execute_shell(to_free,
6833 funcp->body_as_string,
6840 static int run_function(const struct function *funcp, char **argv)
6846 save_and_replace_G_args(&sv, argv);
6848 /* "we are in function, ok to use return" */
6849 sv_flg = G_flag_return_in_progress;
6850 G_flag_return_in_progress = -1;
6851 # if ENABLE_HUSH_LOCAL
6852 G.func_nest_level++;
6855 /* On MMU, funcp->body is always non-NULL */
6858 /* Function defined by -F */
6859 parse_and_run_string(funcp->body_as_string);
6860 rc = G.last_exitcode;
6864 rc = run_list(funcp->body);
6867 # if ENABLE_HUSH_LOCAL
6869 struct variable *var;
6870 struct variable **var_pp;
6872 var_pp = &G.top_var;
6873 while ((var = *var_pp) != NULL) {
6874 if (var->func_nest_level < G.func_nest_level) {
6875 var_pp = &var->next;
6879 if (var->flg_export)
6880 bb_unsetenv(var->varstr);
6881 /* Remove from global list */
6882 *var_pp = var->next;
6888 G.func_nest_level--;
6891 G_flag_return_in_progress = sv_flg;
6893 restore_G_args(&sv, argv);
6897 #endif /* ENABLE_HUSH_FUNCTIONS */
6901 #define exec_builtin(to_free, x, argv) \
6902 exec_builtin(x, argv)
6904 #define exec_builtin(to_free, x, argv) \
6905 exec_builtin(to_free, argv)
6907 static void exec_builtin(char ***to_free,
6908 const struct built_in_command *x,
6909 char **argv) NORETURN;
6910 static void exec_builtin(char ***to_free,
6911 const struct built_in_command *x,
6917 rcode = x->b_function(argv);
6922 /* On NOMMU, we must never block!
6923 * Example: { sleep 99 | read line; } & echo Ok
6925 re_execute_shell(to_free,
6934 static void execvp_or_die(char **argv) NORETURN;
6935 static void execvp_or_die(char **argv)
6938 debug_printf_exec("execing '%s'\n", argv[0]);
6939 /* Don't propagate SIG_IGN to the child */
6940 if (SPECIAL_JOBSTOP_SIGS != 0)
6941 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6942 execvp(argv[0], argv);
6944 if (errno == EACCES) e = 126;
6945 if (errno == ENOENT) e = 127;
6946 bb_perror_msg("can't execute '%s'", argv[0]);
6950 #if ENABLE_HUSH_MODE_X
6951 static void dump_cmd_in_x_mode(char **argv)
6953 if (G_x_mode && argv) {
6954 /* We want to output the line in one write op */
6962 len += strlen(argv[n++]) + 1;
6968 p += sprintf(p, " %s", argv[n++]);
6976 # define dump_cmd_in_x_mode(argv) ((void)0)
6980 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6981 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6982 #define pseudo_exec(nommu_save, command, argv_expanded) \
6983 pseudo_exec(command, argv_expanded)
6986 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6988 * Don't exit() here. If you don't exec, use _exit instead.
6989 * The at_exit handlers apparently confuse the calling process,
6990 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6992 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6993 char **argv, int assignment_cnt,
6994 char **argv_expanded) NORETURN;
6995 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6996 char **argv, int assignment_cnt,
6997 char **argv_expanded)
7001 new_env = expand_assignments(argv, assignment_cnt);
7002 dump_cmd_in_x_mode(new_env);
7004 if (!argv[assignment_cnt]) {
7005 /* Case when we are here: ... | var=val | ...
7006 * (note that we do not exit early, i.e., do not optimize out
7007 * expand_assignments(): think about ... | var=`sleep 1` | ...
7009 free_strings(new_env);
7010 _exit(EXIT_SUCCESS);
7014 set_vars_and_save_old(new_env);
7015 free(new_env); /* optional */
7016 /* we can also destroy set_vars_and_save_old's return value,
7019 nommu_save->new_env = new_env;
7020 nommu_save->old_vars = set_vars_and_save_old(new_env);
7023 if (argv_expanded) {
7024 argv = argv_expanded;
7026 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7028 nommu_save->argv = argv;
7031 dump_cmd_in_x_mode(argv);
7033 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7034 if (strchr(argv[0], '/') != NULL)
7038 /* Check if the command matches any of the builtins.
7039 * Depending on context, this might be redundant. But it's
7040 * easier to waste a few CPU cycles than it is to figure out
7041 * if this is one of those cases.
7044 /* On NOMMU, it is more expensive to re-execute shell
7045 * just in order to run echo or test builtin.
7046 * It's better to skip it here and run corresponding
7047 * non-builtin later. */
7048 const struct built_in_command *x;
7049 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7051 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7054 #if ENABLE_HUSH_FUNCTIONS
7055 /* Check if the command matches any functions */
7057 const struct function *funcp = find_function(argv[0]);
7059 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7064 #if ENABLE_FEATURE_SH_STANDALONE
7065 /* Check if the command matches any busybox applets */
7067 int a = find_applet_by_name(argv[0]);
7069 # if BB_MMU /* see above why on NOMMU it is not allowed */
7070 if (APPLET_IS_NOEXEC(a)) {
7071 /* Do not leak open fds from opened script files etc */
7072 close_all_FILE_list();
7073 debug_printf_exec("running applet '%s'\n", argv[0]);
7074 run_applet_no_and_exit(a, argv);
7077 /* Re-exec ourselves */
7078 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7079 /* Don't propagate SIG_IGN to the child */
7080 if (SPECIAL_JOBSTOP_SIGS != 0)
7081 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7082 execv(bb_busybox_exec_path, argv);
7083 /* If they called chroot or otherwise made the binary no longer
7084 * executable, fall through */
7089 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7092 execvp_or_die(argv);
7095 /* Called after [v]fork() in run_pipe
7097 static void pseudo_exec(nommu_save_t *nommu_save,
7098 struct command *command,
7099 char **argv_expanded) NORETURN;
7100 static void pseudo_exec(nommu_save_t *nommu_save,
7101 struct command *command,
7102 char **argv_expanded)
7104 if (command->argv) {
7105 pseudo_exec_argv(nommu_save, command->argv,
7106 command->assignment_cnt, argv_expanded);
7109 if (command->group) {
7110 /* Cases when we are here:
7113 * ... | ( list ) | ...
7114 * ... | { list } | ...
7118 debug_printf_exec("pseudo_exec: run_list\n");
7119 reset_traps_to_defaults();
7120 rcode = run_list(command->group);
7121 /* OK to leak memory by not calling free_pipe_list,
7122 * since this process is about to exit */
7125 re_execute_shell(&nommu_save->argv_from_re_execing,
7126 command->group_as_string,
7133 /* Case when we are here: ... | >file */
7134 debug_printf_exec("pseudo_exec'ed null command\n");
7135 _exit(EXIT_SUCCESS);
7139 static const char *get_cmdtext(struct pipe *pi)
7145 /* This is subtle. ->cmdtext is created only on first backgrounding.
7146 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7147 * On subsequent bg argv is trashed, but we won't use it */
7151 argv = pi->cmds[0].argv;
7153 pi->cmdtext = xzalloc(1);
7158 len += strlen(*argv) + 1;
7162 argv = pi->cmds[0].argv;
7164 p = stpcpy(p, *argv);
7171 static void insert_bg_job(struct pipe *pi)
7173 struct pipe *job, **jobp;
7176 /* Linear search for the ID of the job to use */
7178 for (job = G.job_list; job; job = job->next)
7179 if (job->jobid >= pi->jobid)
7180 pi->jobid = job->jobid + 1;
7182 /* Add job to the list of running jobs */
7184 while ((job = *jobp) != NULL)
7186 job = *jobp = xmalloc(sizeof(*job));
7188 *job = *pi; /* physical copy */
7190 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7191 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7192 for (i = 0; i < pi->num_cmds; i++) {
7193 job->cmds[i].pid = pi->cmds[i].pid;
7194 /* all other fields are not used and stay zero */
7196 job->cmdtext = xstrdup(get_cmdtext(pi));
7198 if (G_interactive_fd)
7199 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7200 G.last_jobid = job->jobid;
7203 static void remove_bg_job(struct pipe *pi)
7205 struct pipe *prev_pipe;
7207 if (pi == G.job_list) {
7208 G.job_list = pi->next;
7210 prev_pipe = G.job_list;
7211 while (prev_pipe->next != pi)
7212 prev_pipe = prev_pipe->next;
7213 prev_pipe->next = pi->next;
7216 G.last_jobid = G.job_list->jobid;
7221 /* Remove a backgrounded job */
7222 static void delete_finished_bg_job(struct pipe *pi)
7229 static int job_exited_or_stopped(struct pipe *pi)
7233 if (pi->alive_cmds != pi->stopped_cmds)
7236 /* All processes in fg pipe have exited or stopped */
7240 rcode = pi->cmds[i].cmd_exitcode;
7241 /* usually last process gives overall exitstatus,
7242 * but with "set -o pipefail", last *failed* process does */
7243 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7246 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7250 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7257 dead = WIFEXITED(status) || WIFSIGNALED(status);
7260 if (WIFSTOPPED(status))
7261 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7262 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7263 if (WIFSIGNALED(status))
7264 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7265 childpid, WTERMSIG(status), WEXITSTATUS(status));
7266 if (WIFEXITED(status))
7267 debug_printf_jobs("pid %d exited, exitcode %d\n",
7268 childpid, WEXITSTATUS(status));
7270 /* Were we asked to wait for a fg pipe? */
7272 i = fg_pipe->num_cmds;
7277 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7278 if (fg_pipe->cmds[i].pid != childpid)
7282 fg_pipe->cmds[i].pid = 0;
7283 fg_pipe->alive_cmds--;
7284 ex = WEXITSTATUS(status);
7285 /* bash prints killer signal's name for *last*
7286 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7287 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7289 if (WIFSIGNALED(status)) {
7290 int sig = WTERMSIG(status);
7291 if (i == fg_pipe->num_cmds-1)
7292 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7293 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7294 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7295 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7296 * Maybe we need to use sig | 128? */
7299 fg_pipe->cmds[i].cmd_exitcode = ex;
7301 fg_pipe->stopped_cmds++;
7303 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7304 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7305 rcode = job_exited_or_stopped(fg_pipe);
7307 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7308 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7309 * and "killall -STOP cat" */
7310 if (G_interactive_fd) {
7312 if (fg_pipe->alive_cmds != 0)
7313 insert_bg_job(fg_pipe);
7317 if (fg_pipe->alive_cmds == 0)
7320 /* There are still running processes in the fg_pipe */
7323 /* It wasn't in fg_pipe, look for process in bg pipes */
7327 /* We were asked to wait for bg or orphaned children */
7328 /* No need to remember exitcode in this case */
7329 for (pi = G.job_list; pi; pi = pi->next) {
7330 for (i = 0; i < pi->num_cmds; i++) {
7331 if (pi->cmds[i].pid == childpid)
7332 goto found_pi_and_prognum;
7335 /* Happens when shell is used as init process (init=/bin/sh) */
7336 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7337 return -1; /* this wasn't a process from fg_pipe */
7339 found_pi_and_prognum:
7342 pi->cmds[i].pid = 0;
7343 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7344 if (WIFSIGNALED(status))
7345 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7347 if (!pi->alive_cmds) {
7348 if (G_interactive_fd)
7349 printf(JOB_STATUS_FORMAT, pi->jobid,
7350 "Done", pi->cmdtext);
7351 delete_finished_bg_job(pi);
7358 return -1; /* this wasn't a process from fg_pipe */
7361 /* Check to see if any processes have exited -- if they have,
7362 * figure out why and see if a job has completed.
7364 * If non-NULL fg_pipe: wait for its completion or stop.
7365 * Return its exitcode or zero if stopped.
7367 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7368 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7369 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7370 * or 0 if no children changed status.
7372 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7373 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7374 * or 0 if no children changed status.
7376 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7382 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7384 attributes = WUNTRACED;
7385 if (fg_pipe == NULL)
7386 attributes |= WNOHANG;
7389 #if ENABLE_HUSH_FAST
7390 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7391 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7392 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7393 /* There was neither fork nor SIGCHLD since last waitpid */
7394 /* Avoid doing waitpid syscall if possible */
7395 if (!G.we_have_children) {
7399 if (fg_pipe == NULL) { /* is WNOHANG set? */
7400 /* We have children, but they did not exit
7401 * or stop yet (we saw no SIGCHLD) */
7404 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7408 /* Do we do this right?
7409 * bash-3.00# sleep 20 | false
7411 * [3]+ Stopped sleep 20 | false
7412 * bash-3.00# echo $?
7413 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7414 * [hush 1.14.0: yes we do it right]
7418 #if ENABLE_HUSH_FAST
7420 i = G.count_SIGCHLD;
7422 childpid = waitpid(-1, &status, attributes);
7423 if (childpid <= 0) {
7424 if (childpid && errno != ECHILD)
7425 bb_perror_msg("waitpid");
7426 #if ENABLE_HUSH_FAST
7427 else { /* Until next SIGCHLD, waitpid's are useless */
7428 G.we_have_children = (childpid == 0);
7429 G.handled_SIGCHLD = i;
7430 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7433 /* ECHILD (no children), or 0 (no change in children status) */
7437 rcode = process_wait_result(fg_pipe, childpid, status);
7439 /* fg_pipe exited or stopped */
7442 if (childpid == waitfor_pid) {
7443 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7444 rcode = WEXITSTATUS(status);
7445 if (WIFSIGNALED(status))
7446 rcode = 128 + WTERMSIG(status);
7447 if (WIFSTOPPED(status))
7448 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7449 rcode = 128 + WSTOPSIG(status);
7451 break; /* "wait PID" called us, give it exitcode+1 */
7453 /* This wasn't one of our processes, or */
7454 /* fg_pipe still has running processes, do waitpid again */
7455 } /* while (waitpid succeeds)... */
7461 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7464 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7465 if (G_saved_tty_pgrp) {
7466 /* Job finished, move the shell to the foreground */
7467 p = getpgrp(); /* our process group id */
7468 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7469 tcsetpgrp(G_interactive_fd, p);
7475 /* Start all the jobs, but don't wait for anything to finish.
7478 * Return code is normally -1, when the caller has to wait for children
7479 * to finish to determine the exit status of the pipe. If the pipe
7480 * is a simple builtin command, however, the action is done by the
7481 * time run_pipe returns, and the exit code is provided as the
7484 * Returns -1 only if started some children. IOW: we have to
7485 * mask out retvals of builtins etc with 0xff!
7487 * The only case when we do not need to [v]fork is when the pipe
7488 * is single, non-backgrounded, non-subshell command. Examples:
7489 * cmd ; ... { list } ; ...
7490 * cmd && ... { list } && ...
7491 * cmd || ... { list } || ...
7492 * If it is, then we can run cmd as a builtin, NOFORK,
7493 * or (if SH_STANDALONE) an applet, and we can run the { list }
7494 * with run_list. If it isn't one of these, we fork and exec cmd.
7496 * Cases when we must fork:
7497 * non-single: cmd | cmd
7498 * backgrounded: cmd & { list } &
7499 * subshell: ( list ) [&]
7501 #if !ENABLE_HUSH_MODE_X
7502 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7503 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7505 static int redirect_and_varexp_helper(char ***new_env_p,
7506 struct variable **old_vars_p,
7507 struct command *command,
7509 char **argv_expanded)
7511 /* setup_redirects acts on file descriptors, not FILEs.
7512 * This is perfect for work that comes after exec().
7513 * Is it really safe for inline use? Experimentally,
7514 * things seem to work. */
7515 int rcode = setup_redirects(command, squirrel);
7517 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7518 *new_env_p = new_env;
7519 dump_cmd_in_x_mode(new_env);
7520 dump_cmd_in_x_mode(argv_expanded);
7522 *old_vars_p = set_vars_and_save_old(new_env);
7526 static NOINLINE int run_pipe(struct pipe *pi)
7528 static const char *const null_ptr = NULL;
7532 struct command *command;
7533 char **argv_expanded;
7535 /* it is not always needed, but we aim to smaller code */
7536 int squirrel[] = { -1, -1, -1 };
7539 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7542 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7543 * Result should be 3 lines: q w e, qwe, q w e
7545 G.ifs = get_local_var_value("IFS");
7549 IF_HUSH_JOB(pi->pgrp = -1;)
7550 pi->stopped_cmds = 0;
7551 command = &pi->cmds[0];
7552 argv_expanded = NULL;
7554 if (pi->num_cmds != 1
7555 || pi->followup == PIPE_BG
7556 || command->cmd_type == CMD_SUBSHELL
7563 debug_printf_exec(": group:%p argv:'%s'\n",
7564 command->group, command->argv ? command->argv[0] : "NONE");
7566 if (command->group) {
7567 #if ENABLE_HUSH_FUNCTIONS
7568 if (command->cmd_type == CMD_FUNCDEF) {
7569 /* "executing" func () { list } */
7570 struct function *funcp;
7572 funcp = new_function(command->argv[0]);
7573 /* funcp->name is already set to argv[0] */
7574 funcp->body = command->group;
7576 funcp->body_as_string = command->group_as_string;
7577 command->group_as_string = NULL;
7579 command->group = NULL;
7580 command->argv[0] = NULL;
7581 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7582 funcp->parent_cmd = command;
7583 command->child_func = funcp;
7585 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7587 return EXIT_SUCCESS;
7591 debug_printf("non-subshell group\n");
7592 rcode = 1; /* exitcode if redir failed */
7593 if (setup_redirects(command, squirrel) == 0) {
7594 debug_printf_exec(": run_list\n");
7595 rcode = run_list(command->group) & 0xff;
7597 restore_redirects(squirrel);
7598 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7600 debug_printf_exec("run_pipe: return %d\n", rcode);
7604 argv = command->argv ? command->argv : (char **) &null_ptr;
7606 const struct built_in_command *x;
7607 #if ENABLE_HUSH_FUNCTIONS
7608 const struct function *funcp;
7612 char **new_env = NULL;
7613 struct variable *old_vars = NULL;
7615 if (argv[command->assignment_cnt] == NULL) {
7616 /* Assignments, but no command */
7617 /* Ensure redirects take effect (that is, create files).
7618 * Try "a=t >file" */
7619 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7620 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7621 /* Set shell variables */
7625 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7626 /* Do we need to flag set_local_var() errors?
7627 * "assignment to readonly var" and "putenv error"
7632 /* Redirect error sets $? to 1. Otherwise,
7633 * if evaluating assignment value set $?, retain it.
7634 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7636 rcode = G.last_exitcode;
7637 /* Exit, _skipping_ variable restoring code: */
7638 goto clean_up_and_ret0;
7640 #else /* Older, bigger, but more correct code */
7642 rcode = setup_redirects(command, squirrel);
7643 restore_redirects(squirrel);
7644 /* Set shell variables */
7646 bb_putchar_stderr('+');
7648 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7650 fprintf(stderr, " %s", p);
7651 debug_printf_exec("set shell var:'%s'->'%s'\n",
7653 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7654 /* Do we need to flag set_local_var() errors?
7655 * "assignment to readonly var" and "putenv error"
7660 bb_putchar_stderr('\n');
7661 /* Redirect error sets $? to 1. Otherwise,
7662 * if evaluating assignment value set $?, retain it.
7663 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7665 rcode = G.last_exitcode;
7666 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7668 debug_printf_exec("run_pipe: return %d\n", rcode);
7673 /* Expand the rest into (possibly) many strings each */
7675 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7676 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7680 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7683 /* if someone gives us an empty string: `cmd with empty output` */
7684 if (!argv_expanded[0]) {
7685 free(argv_expanded);
7687 return G.last_exitcode;
7690 x = find_builtin(argv_expanded[0]);
7691 #if ENABLE_HUSH_FUNCTIONS
7694 funcp = find_function(argv_expanded[0]);
7698 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7699 debug_printf("exec with redirects only\n");
7700 rcode = setup_redirects(command, NULL);
7701 /* rcode=1 can be if redir file can't be opened */
7702 goto clean_up_and_ret1;
7705 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7708 debug_printf_exec(": builtin '%s' '%s'...\n",
7709 x->b_cmd, argv_expanded[1]);
7711 rcode = x->b_function(argv_expanded) & 0xff;
7714 #if ENABLE_HUSH_FUNCTIONS
7716 # if ENABLE_HUSH_LOCAL
7717 struct variable **sv;
7718 sv = G.shadowed_vars_pp;
7719 G.shadowed_vars_pp = &old_vars;
7721 debug_printf_exec(": function '%s' '%s'...\n",
7722 funcp->name, argv_expanded[1]);
7723 rcode = run_function(funcp, argv_expanded) & 0xff;
7724 # if ENABLE_HUSH_LOCAL
7725 G.shadowed_vars_pp = sv;
7731 unset_vars(new_env);
7733 /* clean_up_and_ret0: */
7734 restore_redirects(squirrel);
7736 free(argv_expanded);
7737 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7739 debug_printf_exec("run_pipe return %d\n", rcode);
7743 if (ENABLE_FEATURE_SH_NOFORK) {
7744 int n = find_applet_by_name(argv_expanded[0]);
7745 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7746 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7748 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7749 argv_expanded[0], argv_expanded[1]);
7750 rcode = run_nofork_applet(n, argv_expanded);
7752 goto clean_up_and_ret;
7755 /* It is neither builtin nor applet. We must fork. */
7759 /* NB: argv_expanded may already be created, and that
7760 * might include `cmd` runs! Do not rerun it! We *must*
7761 * use argv_expanded if it's non-NULL */
7763 /* Going to fork a child per each pipe member */
7768 while (cmd_no < pi->num_cmds) {
7769 struct fd_pair pipefds;
7771 volatile nommu_save_t nommu_save;
7772 nommu_save.new_env = NULL;
7773 nommu_save.old_vars = NULL;
7774 nommu_save.argv = NULL;
7775 nommu_save.argv_from_re_execing = NULL;
7777 command = &pi->cmds[cmd_no];
7779 if (command->argv) {
7780 debug_printf_exec(": pipe member '%s' '%s'...\n",
7781 command->argv[0], command->argv[1]);
7783 debug_printf_exec(": pipe member with no argv\n");
7786 /* pipes are inserted between pairs of commands */
7789 if (cmd_no < pi->num_cmds)
7790 xpiped_pair(pipefds);
7792 command->pid = BB_MMU ? fork() : vfork();
7793 if (!command->pid) { /* child */
7795 disable_restore_tty_pgrp_on_exit();
7796 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7798 /* Every child adds itself to new process group
7799 * with pgid == pid_of_first_child_in_pipe */
7800 if (G.run_list_level == 1 && G_interactive_fd) {
7803 if (pgrp < 0) /* true for 1st process only */
7805 if (setpgid(0, pgrp) == 0
7806 && pi->followup != PIPE_BG
7807 && G_saved_tty_pgrp /* we have ctty */
7809 /* We do it in *every* child, not just first,
7811 tcsetpgrp(G_interactive_fd, pgrp);
7815 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7816 /* 1st cmd in backgrounded pipe
7817 * should have its stdin /dev/null'ed */
7819 if (open(bb_dev_null, O_RDONLY))
7820 xopen("/", O_RDONLY);
7822 xmove_fd(next_infd, 0);
7824 xmove_fd(pipefds.wr, 1);
7827 /* Like bash, explicit redirects override pipes,
7828 * and the pipe fd (fd#1) is available for dup'ing:
7829 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7830 * of cmd1 goes into pipe.
7832 if (setup_redirects(command, NULL)) {
7833 /* Happens when redir file can't be opened:
7834 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7836 * hush: can't open '/qwe/rty': No such file or directory
7838 * (echo BAR is not executed, it hits _exit(1) below)
7843 /* Stores to nommu_save list of env vars putenv'ed
7844 * (NOMMU, on MMU we don't need that) */
7845 /* cast away volatility... */
7846 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7847 /* pseudo_exec() does not return */
7850 /* parent or error */
7851 #if ENABLE_HUSH_FAST
7853 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7855 enable_restore_tty_pgrp_on_exit();
7857 /* Clean up after vforked child */
7858 free(nommu_save.argv);
7859 free(nommu_save.argv_from_re_execing);
7860 unset_vars(nommu_save.new_env);
7861 add_vars(nommu_save.old_vars);
7863 free(argv_expanded);
7864 argv_expanded = NULL;
7865 if (command->pid < 0) { /* [v]fork failed */
7866 /* Clearly indicate, was it fork or vfork */
7867 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7871 /* Second and next children need to know pid of first one */
7873 pi->pgrp = command->pid;
7879 if (cmd_no < pi->num_cmds)
7881 /* Pass read (output) pipe end to next iteration */
7882 next_infd = pipefds.rd;
7885 if (!pi->alive_cmds) {
7887 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7892 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7896 /* NB: called by pseudo_exec, and therefore must not modify any
7897 * global data until exec/_exit (we can be a child after vfork!) */
7898 static int run_list(struct pipe *pi)
7900 #if ENABLE_HUSH_CASE
7901 char *case_word = NULL;
7903 #if ENABLE_HUSH_LOOPS
7904 struct pipe *loop_top = NULL;
7905 char **for_lcur = NULL;
7906 char **for_list = NULL;
7908 smallint last_followup;
7910 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7911 smalluint cond_code = 0;
7913 enum { cond_code = 0 };
7916 smallint rword; /* RES_foo */
7917 smallint last_rword; /* ditto */
7920 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7923 #if ENABLE_HUSH_LOOPS
7924 /* Check syntax for "for" */
7927 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7928 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7930 /* current word is FOR or IN (BOLD in comments below) */
7931 if (cpipe->next == NULL) {
7932 syntax_error("malformed for");
7934 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7937 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7938 if (cpipe->next->res_word == RES_DO)
7940 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7941 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7942 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7944 syntax_error("malformed for");
7946 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7953 /* Past this point, all code paths should jump to ret: label
7954 * in order to return, no direct "return" statements please.
7955 * This helps to ensure that no memory is leaked. */
7963 last_rword = RES_XXXX;
7965 last_followup = PIPE_SEQ;
7966 rcode = G.last_exitcode;
7968 /* Go through list of pipes, (maybe) executing them. */
7969 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7974 if (G_flag_return_in_progress == 1)
7977 IF_HAS_KEYWORDS(rword = pi->res_word;)
7978 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7979 rword, cond_code, last_rword);
7980 #if ENABLE_HUSH_LOOPS
7981 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7982 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7984 /* start of a loop: remember where loop starts */
7989 /* Still in the same "if...", "then..." or "do..." branch? */
7990 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7991 if ((rcode == 0 && last_followup == PIPE_OR)
7992 || (rcode != 0 && last_followup == PIPE_AND)
7994 /* It is "<true> || CMD" or "<false> && CMD"
7995 * and we should not execute CMD */
7996 debug_printf_exec("skipped cmd because of || or &&\n");
7997 last_followup = pi->followup;
7998 goto dont_check_jobs_but_continue;
8001 last_followup = pi->followup;
8002 IF_HAS_KEYWORDS(last_rword = rword;)
8005 if (rword == RES_THEN) {
8006 /* if false; then ... fi has exitcode 0! */
8007 G.last_exitcode = rcode = EXIT_SUCCESS;
8008 /* "if <false> THEN cmd": skip cmd */
8012 if (rword == RES_ELSE || rword == RES_ELIF) {
8013 /* "if <true> then ... ELSE/ELIF cmd":
8014 * skip cmd and all following ones */
8019 #if ENABLE_HUSH_LOOPS
8020 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8022 /* first loop through for */
8024 static const char encoded_dollar_at[] ALIGN1 = {
8025 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8026 }; /* encoded representation of "$@" */
8027 static const char *const encoded_dollar_at_argv[] = {
8028 encoded_dollar_at, NULL
8029 }; /* argv list with one element: "$@" */
8032 vals = (char**)encoded_dollar_at_argv;
8033 if (pi->next->res_word == RES_IN) {
8034 /* if no variable values after "in" we skip "for" */
8035 if (!pi->next->cmds[0].argv) {
8036 G.last_exitcode = rcode = EXIT_SUCCESS;
8037 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8040 vals = pi->next->cmds[0].argv;
8041 } /* else: "for var; do..." -> assume "$@" list */
8042 /* create list of variable values */
8043 debug_print_strings("for_list made from", vals);
8044 for_list = expand_strvec_to_strvec(vals);
8045 for_lcur = for_list;
8046 debug_print_strings("for_list", for_list);
8049 /* "for" loop is over, clean up */
8055 /* Insert next value from for_lcur */
8056 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8057 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8060 if (rword == RES_IN) {
8061 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8063 if (rword == RES_DONE) {
8064 continue; /* "done" has no cmds too */
8067 #if ENABLE_HUSH_CASE
8068 if (rword == RES_CASE) {
8069 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8070 case_word = expand_strvec_to_string(pi->cmds->argv);
8073 if (rword == RES_MATCH) {
8076 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8077 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8079 /* all prev words didn't match, does this one match? */
8080 argv = pi->cmds->argv;
8082 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8083 /* TODO: which FNM_xxx flags to use? */
8084 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8086 if (cond_code == 0) { /* match! we will execute this branch */
8088 case_word = NULL; /* make future "word)" stop */
8095 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8096 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8098 continue; /* not matched yet, skip this pipe */
8100 if (rword == RES_ESAC) {
8101 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8103 /* "case" did not match anything: still set $? (to 0) */
8104 G.last_exitcode = rcode = EXIT_SUCCESS;
8108 /* Just pressing <enter> in shell should check for jobs.
8109 * OTOH, in non-interactive shell this is useless
8110 * and only leads to extra job checks */
8111 if (pi->num_cmds == 0) {
8112 if (G_interactive_fd)
8113 goto check_jobs_and_continue;
8117 /* After analyzing all keywords and conditions, we decided
8118 * to execute this pipe. NB: have to do checkjobs(NULL)
8119 * after run_pipe to collect any background children,
8120 * even if list execution is to be stopped. */
8121 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8122 #if ENABLE_HUSH_LOOPS
8123 G.flag_break_continue = 0;
8125 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8127 /* We ran a builtin, function, or group.
8128 * rcode is already known
8129 * and we don't need to wait for anything. */
8130 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8131 G.last_exitcode = rcode;
8132 check_and_run_traps();
8133 #if ENABLE_HUSH_LOOPS
8134 /* Was it "break" or "continue"? */
8135 if (G.flag_break_continue) {
8136 smallint fbc = G.flag_break_continue;
8137 /* We might fall into outer *loop*,
8138 * don't want to break it too */
8140 G.depth_break_continue--;
8141 if (G.depth_break_continue == 0)
8142 G.flag_break_continue = 0;
8143 /* else: e.g. "continue 2" should *break* once, *then* continue */
8144 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8145 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8146 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8149 /* "continue": simulate end of loop */
8154 if (G_flag_return_in_progress == 1) {
8155 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8158 } else if (pi->followup == PIPE_BG) {
8159 /* What does bash do with attempts to background builtins? */
8160 /* even bash 3.2 doesn't do that well with nested bg:
8161 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8162 * I'm NOT treating inner &'s as jobs */
8164 if (G.run_list_level == 1)
8167 /* Last command's pid goes to $! */
8168 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8169 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8170 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8171 rcode = EXIT_SUCCESS;
8175 if (G.run_list_level == 1 && G_interactive_fd) {
8176 /* Waits for completion, then fg's main shell */
8177 rcode = checkjobs_and_fg_shell(pi);
8178 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8182 /* This one just waits for completion */
8183 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8184 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8186 G.last_exitcode = rcode;
8187 check_and_run_traps();
8190 /* Analyze how result affects subsequent commands */
8192 if (rword == RES_IF || rword == RES_ELIF)
8195 check_jobs_and_continue:
8196 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8197 dont_check_jobs_but_continue: ;
8198 #if ENABLE_HUSH_LOOPS
8199 /* Beware of "while false; true; do ..."! */
8201 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8202 /* check for RES_DONE is needed for "while ...; do \n done" case */
8204 if (rword == RES_WHILE) {
8206 /* "while false; do...done" - exitcode 0 */
8207 G.last_exitcode = rcode = EXIT_SUCCESS;
8208 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8212 if (rword == RES_UNTIL) {
8214 debug_printf_exec(": until expr is true: breaking\n");
8225 #if ENABLE_HUSH_LOOPS
8230 #if ENABLE_HUSH_CASE
8234 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8238 /* Select which version we will use */
8239 static int run_and_free_list(struct pipe *pi)
8242 debug_printf_exec("run_and_free_list entered\n");
8243 if (!G.o_opt[OPT_O_NOEXEC]) {
8244 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8245 rcode = run_list(pi);
8247 /* free_pipe_list has the side effect of clearing memory.
8248 * In the long run that function can be merged with run_list,
8249 * but doing that now would hobble the debugging effort. */
8251 debug_printf_exec("run_and_free_list return %d\n", rcode);
8256 static void install_sighandlers(unsigned mask)
8258 sighandler_t old_handler;
8260 while ((mask >>= 1) != 0) {
8264 old_handler = install_sighandler(sig, pick_sighandler(sig));
8265 /* POSIX allows shell to re-enable SIGCHLD
8266 * even if it was SIG_IGN on entry.
8267 * Therefore we skip IGN check for it:
8271 if (old_handler == SIG_IGN) {
8272 /* oops... restore back to IGN, and record this fact */
8273 install_sighandler(sig, old_handler);
8274 #if ENABLE_HUSH_TRAP
8276 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8278 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8284 /* Called a few times only (or even once if "sh -c") */
8285 static void install_special_sighandlers(void)
8289 /* Which signals are shell-special? */
8290 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8291 if (G_interactive_fd) {
8292 mask |= SPECIAL_INTERACTIVE_SIGS;
8293 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8294 mask |= SPECIAL_JOBSTOP_SIGS;
8296 /* Careful, do not re-install handlers we already installed */
8297 if (G.special_sig_mask != mask) {
8298 unsigned diff = mask & ~G.special_sig_mask;
8299 G.special_sig_mask = mask;
8300 install_sighandlers(diff);
8306 /* Set handlers to restore tty pgrp and exit */
8307 static void install_fatal_sighandlers(void)
8311 /* We will restore tty pgrp on these signals */
8313 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8314 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8315 + (1 << SIGBUS ) * HUSH_DEBUG
8316 + (1 << SIGSEGV) * HUSH_DEBUG
8317 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8319 /* bash 3.2 seems to handle these just like 'fatal' ones */
8322 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8323 * if we aren't interactive... but in this case
8324 * we never want to restore pgrp on exit, and this fn is not called
8326 /*+ (1 << SIGHUP )*/
8327 /*+ (1 << SIGTERM)*/
8328 /*+ (1 << SIGINT )*/
8330 G_fatal_sig_mask = mask;
8332 install_sighandlers(mask);
8336 static int set_mode(int state, char mode, const char *o_opt)
8341 G.o_opt[OPT_O_NOEXEC] = state;
8344 IF_HUSH_MODE_X(G_x_mode = state;)
8348 /* "set -+o" without parameter.
8349 * in bash, set -o produces this output:
8353 * We always use the second form.
8355 const char *p = o_opt_strings;
8358 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8364 idx = index_in_strings(o_opt_strings, o_opt);
8366 G.o_opt[idx] = state;
8370 return EXIT_FAILURE;
8372 return EXIT_SUCCESS;
8375 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8376 int hush_main(int argc, char **argv)
8379 OPT_login = (1 << 0),
8383 unsigned builtin_argc;
8385 struct variable *cur_var;
8386 struct variable *shell_ver;
8389 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8390 G.last_exitcode = EXIT_SUCCESS;
8392 #if ENABLE_HUSH_FAST
8393 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8396 G.argv0_for_re_execing = argv[0];
8398 /* Deal with HUSH_VERSION */
8399 shell_ver = xzalloc(sizeof(*shell_ver));
8400 shell_ver->flg_export = 1;
8401 shell_ver->flg_read_only = 1;
8402 /* Code which handles ${var<op>...} needs writable values for all variables,
8403 * therefore we xstrdup: */
8404 shell_ver->varstr = xstrdup(hush_version_str);
8405 /* Create shell local variables from the values
8406 * currently living in the environment */
8407 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8408 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8409 G.top_var = shell_ver;
8410 cur_var = G.top_var;
8413 char *value = strchr(*e, '=');
8414 if (value) { /* paranoia */
8415 cur_var->next = xzalloc(sizeof(*cur_var));
8416 cur_var = cur_var->next;
8417 cur_var->varstr = *e;
8418 cur_var->max_len = strlen(*e);
8419 cur_var->flg_export = 1;
8423 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8424 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8425 putenv(shell_ver->varstr);
8428 set_pwd_var(/*exp:*/ 1);
8430 #if BASH_HOSTNAME_VAR
8431 /* Set (but not export) HOSTNAME unless already set */
8432 if (!get_local_var_value("HOSTNAME")) {
8435 set_local_var_from_halves("HOSTNAME", uts.nodename);
8437 /* bash also exports SHLVL and _,
8438 * and sets (but doesn't export) the following variables:
8440 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8441 * BASH_VERSION='3.2.0(1)-release'
8443 * MACHTYPE=i386-pc-linux-gnu
8445 * PPID=<NNNNN> - we also do it elsewhere
8456 * PIPESTATUS=([0]="0")
8457 * HISTFILE=/<xxx>/.bash_history
8461 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8463 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8474 #if ENABLE_FEATURE_EDITING
8475 G.line_input_state = new_line_input_t(FOR_SHELL);
8478 /* Initialize some more globals to non-zero values */
8479 cmdedit_update_prompt();
8481 die_func = restore_ttypgrp_and__exit;
8483 /* Shell is non-interactive at first. We need to call
8484 * install_special_sighandlers() if we are going to execute "sh <script>",
8485 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8486 * If we later decide that we are interactive, we run install_special_sighandlers()
8487 * in order to intercept (more) signals.
8491 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8492 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8495 opt = getopt(argc, argv, "+c:xinsl"
8498 # if ENABLE_HUSH_FUNCTIONS
8508 * sh ... -c 'script'
8509 * sh ... -c 'script' ARG0 [ARG1...]
8510 * On NOMMU, if builtin_argc != 0,
8511 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8512 * "" needs to be replaced with NULL
8513 * and BARGV vector fed to builtin function.
8514 * Note: the form without ARG0 never happens:
8515 * sh ... -c 'builtin' BARGV... ""
8518 G.root_pid = getpid();
8519 G.root_ppid = getppid();
8521 G.global_argv = argv + optind;
8522 G.global_argc = argc - optind;
8524 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8525 const struct built_in_command *x;
8527 install_special_sighandlers();
8528 x = find_builtin(optarg);
8529 if (x) { /* paranoia */
8530 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8531 G.global_argv += builtin_argc;
8532 G.global_argv[-1] = NULL; /* replace "" */
8534 G.last_exitcode = x->b_function(argv + optind - 1);
8538 if (!G.global_argv[0]) {
8539 /* -c 'script' (no params): prevent empty $0 */
8540 G.global_argv--; /* points to argv[i] of 'script' */
8541 G.global_argv[0] = argv[0];
8543 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8544 install_special_sighandlers();
8545 parse_and_run_string(optarg);
8548 /* Well, we cannot just declare interactiveness,
8549 * we have to have some stuff (ctty, etc) */
8550 /* G_interactive_fd++; */
8553 /* "-s" means "read from stdin", but this is how we always
8554 * operate, so simply do nothing here. */
8560 case '<': /* "big heredoc" support */
8561 full_write1_str(optarg);
8564 unsigned long long empty_trap_mask;
8566 G.root_pid = bb_strtou(optarg, &optarg, 16);
8568 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8570 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8572 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8574 builtin_argc = bb_strtou(optarg, &optarg, 16);
8576 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8577 if (empty_trap_mask != 0) {
8578 IF_HUSH_TRAP(int sig;)
8579 install_special_sighandlers();
8580 # if ENABLE_HUSH_TRAP
8581 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8582 for (sig = 1; sig < NSIG; sig++) {
8583 if (empty_trap_mask & (1LL << sig)) {
8584 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8585 install_sighandler(sig, SIG_IGN);
8590 # if ENABLE_HUSH_LOOPS
8592 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8598 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8600 # if ENABLE_HUSH_FUNCTIONS
8602 struct function *funcp = new_function(optarg);
8603 /* funcp->name is already set to optarg */
8604 /* funcp->body is set to NULL. It's a special case. */
8605 funcp->body_as_string = argv[optind];
8613 if (set_mode(1, opt, NULL) == 0) /* no error */
8617 fprintf(stderr, "Usage: sh [FILE]...\n"
8618 " or: sh -c command [args]...\n\n");
8624 } /* option parsing loop */
8626 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8627 G.global_argc = argc - (optind - 1);
8628 G.global_argv = argv + (optind - 1);
8629 G.global_argv[0] = argv[0];
8632 G.root_pid = getpid();
8633 G.root_ppid = getppid();
8636 /* If we are login shell... */
8637 if (flags & OPT_login) {
8639 debug_printf("sourcing /etc/profile\n");
8640 input = fopen_for_read("/etc/profile");
8641 if (input != NULL) {
8642 remember_FILE(input);
8643 install_special_sighandlers();
8644 parse_and_run_file(input);
8645 fclose_and_forget(input);
8647 /* bash: after sourcing /etc/profile,
8648 * tries to source (in the given order):
8649 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8650 * stopping on first found. --noprofile turns this off.
8651 * bash also sources ~/.bash_logout on exit.
8652 * If called as sh, skips .bash_XXX files.
8656 if (G.global_argv[1]) {
8659 * "bash <script>" (which is never interactive (unless -i?))
8660 * sources $BASH_ENV here (without scanning $PATH).
8661 * If called as sh, does the same but with $ENV.
8662 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8666 debug_printf("running script '%s'\n", G.global_argv[0]);
8667 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8668 input = xfopen_for_read(G.global_argv[0]);
8669 xfunc_error_retval = 1;
8670 remember_FILE(input);
8671 install_special_sighandlers();
8672 parse_and_run_file(input);
8673 #if ENABLE_FEATURE_CLEAN_UP
8674 fclose_and_forget(input);
8679 /* Up to here, shell was non-interactive. Now it may become one.
8680 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8683 /* A shell is interactive if the '-i' flag was given,
8684 * or if all of the following conditions are met:
8686 * no arguments remaining or the -s flag given
8687 * standard input is a terminal
8688 * standard output is a terminal
8689 * Refer to Posix.2, the description of the 'sh' utility.
8692 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8693 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8694 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8695 if (G_saved_tty_pgrp < 0)
8696 G_saved_tty_pgrp = 0;
8698 /* try to dup stdin to high fd#, >= 255 */
8699 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8700 if (G_interactive_fd < 0) {
8701 /* try to dup to any fd */
8702 G_interactive_fd = dup(STDIN_FILENO);
8703 if (G_interactive_fd < 0) {
8705 G_interactive_fd = 0;
8706 G_saved_tty_pgrp = 0;
8709 // TODO: track & disallow any attempts of user
8710 // to (inadvertently) close/redirect G_interactive_fd
8712 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8713 if (G_interactive_fd) {
8714 close_on_exec_on(G_interactive_fd);
8716 if (G_saved_tty_pgrp) {
8717 /* If we were run as 'hush &', sleep until we are
8718 * in the foreground (tty pgrp == our pgrp).
8719 * If we get started under a job aware app (like bash),
8720 * make sure we are now in charge so we don't fight over
8721 * who gets the foreground */
8723 pid_t shell_pgrp = getpgrp();
8724 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8725 if (G_saved_tty_pgrp == shell_pgrp)
8727 /* send TTIN to ourself (should stop us) */
8728 kill(- shell_pgrp, SIGTTIN);
8732 /* Install more signal handlers */
8733 install_special_sighandlers();
8735 if (G_saved_tty_pgrp) {
8736 /* Set other signals to restore saved_tty_pgrp */
8737 install_fatal_sighandlers();
8738 /* Put ourselves in our own process group
8739 * (bash, too, does this only if ctty is available) */
8740 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8741 /* Grab control of the terminal */
8742 tcsetpgrp(G_interactive_fd, getpid());
8744 enable_restore_tty_pgrp_on_exit();
8746 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8748 const char *hp = get_local_var_value("HISTFILE");
8750 hp = get_local_var_value("HOME");
8752 hp = concat_path_file(hp, ".hush_history");
8757 G.line_input_state->hist_file = hp;
8758 //set_local_var(xasprintf("HISTFILE=%s", ...));
8760 # if ENABLE_FEATURE_SH_HISTFILESIZE
8761 hp = get_local_var_value("HISTFILESIZE");
8762 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8767 install_special_sighandlers();
8769 #elif ENABLE_HUSH_INTERACTIVE
8770 /* No job control compiled in, only prompt/line editing */
8771 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8772 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8773 if (G_interactive_fd < 0) {
8774 /* try to dup to any fd */
8775 G_interactive_fd = dup(STDIN_FILENO);
8776 if (G_interactive_fd < 0)
8778 G_interactive_fd = 0;
8781 if (G_interactive_fd) {
8782 close_on_exec_on(G_interactive_fd);
8784 install_special_sighandlers();
8786 /* We have interactiveness code disabled */
8787 install_special_sighandlers();
8790 * if interactive but not a login shell, sources ~/.bashrc
8791 * (--norc turns this off, --rcfile <file> overrides)
8794 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8795 /* note: ash and hush share this string */
8796 printf("\n\n%s %s\n"
8797 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8800 "hush - the humble shell"
8804 parse_and_run_file(stdin);
8807 hush_exit(G.last_exitcode);
8812 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8813 int msh_main(int argc, char **argv)
8815 bb_error_msg("msh is deprecated, please use hush instead");
8816 return hush_main(argc, argv);
8824 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8829 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8830 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8837 return applet_main_func(argc, argv - argc);
8840 #if ENABLE_HUSH_TEST || BASH_TEST2
8841 static int FAST_FUNC builtin_test(char **argv)
8843 return run_applet_main(argv, test_main);
8846 #if ENABLE_HUSH_ECHO
8847 static int FAST_FUNC builtin_echo(char **argv)
8849 return run_applet_main(argv, echo_main);
8852 #if ENABLE_HUSH_PRINTF
8853 static int FAST_FUNC builtin_printf(char **argv)
8855 return run_applet_main(argv, printf_main);
8859 #if ENABLE_HUSH_HELP
8860 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8862 const struct built_in_command *x;
8865 "Built-in commands:\n"
8866 "------------------\n");
8867 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8869 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8871 return EXIT_SUCCESS;
8875 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8876 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8878 show_history(G.line_input_state);
8879 return EXIT_SUCCESS;
8883 static char **skip_dash_dash(char **argv)
8886 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8891 static int FAST_FUNC builtin_cd(char **argv)
8895 argv = skip_dash_dash(argv);
8897 if (newdir == NULL) {
8898 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8899 * bash says "bash: cd: HOME not set" and does nothing
8902 const char *home = get_local_var_value("HOME");
8903 newdir = home ? home : "/";
8905 if (chdir(newdir)) {
8906 /* Mimic bash message exactly */
8907 bb_perror_msg("cd: %s", newdir);
8908 return EXIT_FAILURE;
8910 /* Read current dir (get_cwd(1) is inside) and set PWD.
8911 * Note: do not enforce exporting. If PWD was unset or unexported,
8912 * set it again, but do not export. bash does the same.
8914 set_pwd_var(/*exp:*/ 0);
8915 return EXIT_SUCCESS;
8918 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8921 return EXIT_SUCCESS;
8924 static int FAST_FUNC builtin_eval(char **argv)
8926 int rcode = EXIT_SUCCESS;
8928 argv = skip_dash_dash(argv);
8930 char *str = expand_strvec_to_string(argv);
8932 * eval "echo Hi; done" ("done" is syntax error):
8933 * "echo Hi" will not execute too.
8935 parse_and_run_string(str);
8937 rcode = G.last_exitcode;
8942 static int FAST_FUNC builtin_exec(char **argv)
8944 argv = skip_dash_dash(argv);
8945 if (argv[0] == NULL)
8946 return EXIT_SUCCESS; /* bash does this */
8948 /* Careful: we can end up here after [v]fork. Do not restore
8949 * tty pgrp then, only top-level shell process does that */
8950 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8951 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8953 /* TODO: if exec fails, bash does NOT exit! We do.
8954 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8955 * and tcsetpgrp, and this is inherently racy.
8957 execvp_or_die(argv);
8960 static int FAST_FUNC builtin_exit(char **argv)
8962 debug_printf_exec("%s()\n", __func__);
8964 /* interactive bash:
8965 * # trap "echo EEE" EXIT
8968 * There are stopped jobs.
8969 * (if there are _stopped_ jobs, running ones don't count)
8972 * EEE (then bash exits)
8974 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8977 /* note: EXIT trap is run by hush_exit */
8978 argv = skip_dash_dash(argv);
8979 if (argv[0] == NULL)
8980 hush_exit(G.last_exitcode);
8981 /* mimic bash: exit 123abc == exit 255 + error msg */
8982 xfunc_error_retval = 255;
8983 /* bash: exit -2 == exit 254, no error msg */
8984 hush_exit(xatoi(argv[0]) & 0xff);
8987 #if ENABLE_HUSH_TYPE
8988 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8989 static int FAST_FUNC builtin_type(char **argv)
8991 int ret = EXIT_SUCCESS;
8997 if (0) {} /* make conditional compile easier below */
8998 /*else if (find_alias(*argv))
8999 type = "an alias";*/
9000 #if ENABLE_HUSH_FUNCTIONS
9001 else if (find_function(*argv))
9002 type = "a function";
9004 else if (find_builtin(*argv))
9005 type = "a shell builtin";
9006 else if ((path = find_in_path(*argv)) != NULL)
9009 bb_error_msg("type: %s: not found", *argv);
9014 printf("%s is %s\n", *argv, type);
9022 #if ENABLE_HUSH_READ
9023 /* Interruptibility of read builtin in bash
9024 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9026 * Empty trap makes read ignore corresponding signal, for any signal.
9029 * - terminates non-interactive shell;
9030 * - interrupts read in interactive shell;
9031 * if it has non-empty trap:
9032 * - executes trap and returns to command prompt in interactive shell;
9033 * - executes trap and returns to read in non-interactive shell;
9035 * - is ignored (does not interrupt) read in interactive shell;
9036 * - terminates non-interactive shell;
9037 * if it has non-empty trap:
9038 * - executes trap and returns to read;
9040 * - terminates shell (regardless of interactivity);
9041 * if it has non-empty trap:
9042 * - executes trap and returns to read;
9043 * SIGCHLD from children:
9044 * - does not interrupt read regardless of interactivity:
9045 * try: sleep 1 & read x; echo $x
9047 static int FAST_FUNC builtin_read(char **argv)
9057 /* "!": do not abort on errors.
9058 * Option string must start with "sr" to match BUILTIN_READ_xxx
9060 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9061 if (read_flags == (uint32_t)-1)
9062 return EXIT_FAILURE;
9064 ifs = get_local_var_value("IFS"); /* can be NULL */
9067 r = shell_builtin_read(set_local_var_from_halves,
9077 if ((uintptr_t)r == 1 && errno == EINTR) {
9078 unsigned sig = check_and_run_traps();
9083 if ((uintptr_t)r > 1) {
9084 bb_error_msg("%s", r);
9085 r = (char*)(uintptr_t)1;
9088 return (uintptr_t)r;
9092 #if ENABLE_HUSH_UMASK
9093 static int FAST_FUNC builtin_umask(char **argv)
9100 argv = skip_dash_dash(argv);
9102 mode_t old_mask = mask;
9104 /* numeric umasks are taken as-is */
9105 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9106 if (!isdigit(argv[0][0]))
9108 mask = bb_parse_mode(argv[0], mask);
9109 if (!isdigit(argv[0][0]))
9111 if ((unsigned)mask > 0777) {
9114 * bash: umask: 'q': invalid symbolic mode operator
9115 * bash: umask: 999: octal number out of range
9117 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9122 printf("%04o\n", (unsigned) mask);
9123 /* fall through and restore mask which we set to 0 */
9127 return !rc; /* rc != 0 - success */
9131 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9132 static void print_escaped(const char *s)
9137 const char *p = strchrnul(s, '\'');
9138 /* print 'xxxx', possibly just '' */
9139 printf("'%.*s'", (int)(p - s), s);
9144 /* s points to '; print "'''...'''" */
9146 do putchar('\''); while (*++s == '\'');
9152 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9153 # if !ENABLE_HUSH_LOCAL
9154 #define helper_export_local(argv, exp, lvl) \
9155 helper_export_local(argv, exp)
9157 static void helper_export_local(char **argv, int exp, int lvl)
9161 char *name_end = strchrnul(name, '=');
9163 /* So far we do not check that name is valid (TODO?) */
9165 if (*name_end == '\0') {
9166 struct variable *var, **vpp;
9168 vpp = get_ptr_to_local_var(name, name_end - name);
9169 var = vpp ? *vpp : NULL;
9171 if (exp == -1) { /* unexporting? */
9172 /* export -n NAME (without =VALUE) */
9174 var->flg_export = 0;
9175 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9177 } /* else: export -n NOT_EXISTING_VAR: no-op */
9180 if (exp == 1) { /* exporting? */
9181 /* export NAME (without =VALUE) */
9183 var->flg_export = 1;
9184 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9185 putenv(var->varstr);
9189 # if ENABLE_HUSH_LOCAL
9190 if (exp == 0 /* local? */
9191 && var && var->func_nest_level == lvl
9193 /* "local x=abc; ...; local x" - ignore second local decl */
9197 /* Exporting non-existing variable.
9198 * bash does not put it in environment,
9199 * but remembers that it is exported,
9200 * and does put it in env when it is set later.
9201 * We just set it to "" and export. */
9202 /* Or, it's "local NAME" (without =VALUE).
9203 * bash sets the value to "". */
9204 name = xasprintf("%s=", name);
9206 /* (Un)exporting/making local NAME=VALUE */
9207 name = xstrdup(name);
9209 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9214 #if ENABLE_HUSH_EXPORT
9215 static int FAST_FUNC builtin_export(char **argv)
9217 unsigned opt_unexport;
9219 #if ENABLE_HUSH_EXPORT_N
9220 /* "!": do not abort on errors */
9221 opt_unexport = getopt32(argv, "!n");
9222 if (opt_unexport == (uint32_t)-1)
9223 return EXIT_FAILURE;
9230 if (argv[0] == NULL) {
9237 /* ash emits: export VAR='VAL'
9238 * bash: declare -x VAR="VAL"
9239 * we follow ash example */
9240 const char *s = *e++;
9241 const char *p = strchr(s, '=');
9243 if (!p) /* wtf? take next variable */
9246 printf("export %.*s", (int)(p - s) + 1, s);
9247 print_escaped(p + 1);
9251 /*fflush_all(); - done after each builtin anyway */
9253 return EXIT_SUCCESS;
9256 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9258 return EXIT_SUCCESS;
9262 #if ENABLE_HUSH_LOCAL
9263 static int FAST_FUNC builtin_local(char **argv)
9265 if (G.func_nest_level == 0) {
9266 bb_error_msg("%s: not in a function", argv[0]);
9267 return EXIT_FAILURE; /* bash compat */
9269 helper_export_local(argv, 0, G.func_nest_level);
9270 return EXIT_SUCCESS;
9274 #if ENABLE_HUSH_UNSET
9275 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9276 static int FAST_FUNC builtin_unset(char **argv)
9281 /* "!": do not abort on errors */
9282 /* "+": stop at 1st non-option */
9283 opts = getopt32(argv, "!+vf");
9284 if (opts == (unsigned)-1)
9285 return EXIT_FAILURE;
9287 bb_error_msg("unset: -v and -f are exclusive");
9288 return EXIT_FAILURE;
9294 if (!(opts & 2)) { /* not -f */
9295 if (unset_local_var(*argv)) {
9296 /* unset <nonexistent_var> doesn't fail.
9297 * Error is when one tries to unset RO var.
9298 * Message was printed by unset_local_var. */
9302 # if ENABLE_HUSH_FUNCTIONS
9314 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9315 * built-in 'set' handler
9317 * set [-abCefhmnuvx] [-o option] [argument...]
9318 * set [+abCefhmnuvx] [+o option] [argument...]
9319 * set -- [argument...]
9322 * Implementations shall support the options in both their hyphen and
9323 * plus-sign forms. These options can also be specified as options to sh.
9325 * Write out all variables and their values: set
9326 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9327 * Turn on the -x and -v options: set -xv
9328 * Unset all positional parameters: set --
9329 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9330 * Set the positional parameters to the expansion of x, even if x expands
9331 * with a leading '-' or '+': set -- $x
9333 * So far, we only support "set -- [argument...]" and some of the short names.
9335 static int FAST_FUNC builtin_set(char **argv)
9338 char **pp, **g_argv;
9339 char *arg = *++argv;
9343 for (e = G.top_var; e; e = e->next)
9345 return EXIT_SUCCESS;
9349 if (strcmp(arg, "--") == 0) {
9353 if (arg[0] != '+' && arg[0] != '-')
9355 for (n = 1; arg[n]; ++n) {
9356 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9358 if (arg[n] == 'o' && argv[1])
9361 } while ((arg = *++argv) != NULL);
9362 /* Now argv[0] is 1st argument */
9365 return EXIT_SUCCESS;
9368 /* NB: G.global_argv[0] ($0) is never freed/changed */
9369 g_argv = G.global_argv;
9370 if (G.global_args_malloced) {
9376 G.global_args_malloced = 1;
9377 pp = xzalloc(sizeof(pp[0]) * 2);
9378 pp[0] = g_argv[0]; /* retain $0 */
9381 /* This realloc's G.global_argv */
9382 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9389 return EXIT_SUCCESS;
9391 /* Nothing known, so abort */
9393 bb_error_msg("set: %s: invalid option", arg);
9394 return EXIT_FAILURE;
9398 static int FAST_FUNC builtin_shift(char **argv)
9401 argv = skip_dash_dash(argv);
9405 if (n >= 0 && n < G.global_argc) {
9406 if (G_global_args_malloced) {
9409 free(G.global_argv[m++]);
9412 memmove(&G.global_argv[1], &G.global_argv[n+1],
9413 G.global_argc * sizeof(G.global_argv[0]));
9414 return EXIT_SUCCESS;
9416 return EXIT_FAILURE;
9419 static int FAST_FUNC builtin_source(char **argv)
9421 char *arg_path, *filename;
9424 char *args_need_save;
9425 #if ENABLE_HUSH_FUNCTIONS
9429 argv = skip_dash_dash(argv);
9432 /* bash says: "bash: .: filename argument required" */
9433 return 2; /* bash compat */
9436 if (!strchr(filename, '/')) {
9437 arg_path = find_in_path(filename);
9439 filename = arg_path;
9441 input = remember_FILE(fopen_or_warn(filename, "r"));
9444 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9445 /* POSIX: non-interactive shell should abort here,
9446 * not merely fail. So far no one complained :)
9448 return EXIT_FAILURE;
9451 #if ENABLE_HUSH_FUNCTIONS
9452 sv_flg = G_flag_return_in_progress;
9453 /* "we are inside sourced file, ok to use return" */
9454 G_flag_return_in_progress = -1;
9456 args_need_save = argv[1]; /* used as a boolean variable */
9458 save_and_replace_G_args(&sv, argv);
9460 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9461 G.last_exitcode = 0;
9462 parse_and_run_file(input);
9463 fclose_and_forget(input);
9465 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9466 restore_G_args(&sv, argv);
9467 #if ENABLE_HUSH_FUNCTIONS
9468 G_flag_return_in_progress = sv_flg;
9471 return G.last_exitcode;
9474 #if ENABLE_HUSH_TRAP
9475 static int FAST_FUNC builtin_trap(char **argv)
9481 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9486 /* No args: print all trapped */
9487 for (i = 0; i < NSIG; ++i) {
9490 print_escaped(G_traps[i]);
9491 /* note: bash adds "SIG", but only if invoked
9492 * as "bash". If called as "sh", or if set -o posix,
9493 * then it prints short signal names.
9494 * We are printing short names: */
9495 printf(" %s\n", get_signame(i));
9498 /*fflush_all(); - done after each builtin anyway */
9499 return EXIT_SUCCESS;
9503 /* If first arg is a number: reset all specified signals */
9504 sig = bb_strtou(*argv, NULL, 10);
9510 sighandler_t handler;
9512 sig = get_signum(*argv++);
9513 if (sig < 0 || sig >= NSIG) {
9515 /* Mimic bash message exactly */
9516 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9521 G_traps[sig] = xstrdup(new_cmd);
9523 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9524 get_signame(sig), sig, G_traps[sig]);
9526 /* There is no signal for 0 (EXIT) */
9531 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9533 /* We are removing trap handler */
9534 handler = pick_sighandler(sig);
9535 install_sighandler(sig, handler);
9540 if (!argv[1]) { /* no second arg */
9541 bb_error_msg("trap: invalid arguments");
9542 return EXIT_FAILURE;
9545 /* First arg is "-": reset all specified to default */
9546 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9547 /* Everything else: set arg as signal handler
9548 * (includes "" case, which ignores signal) */
9549 if (argv[0][0] == '-') {
9550 if (argv[0][1] == '\0') { /* "-" */
9551 /* new_cmd remains NULL: "reset these sigs" */
9554 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9557 /* else: "-something", no special meaning */
9562 goto process_sig_list;
9567 static struct pipe *parse_jobspec(const char *str)
9572 if (sscanf(str, "%%%u", &jobnum) != 1) {
9574 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9576 bb_error_msg("bad argument '%s'", str);
9579 /* It is "%%", "%+" or "%" - current job */
9580 jobnum = G.last_jobid;
9582 bb_error_msg("no current job");
9586 for (pi = G.job_list; pi; pi = pi->next) {
9587 if (pi->jobid == jobnum) {
9591 bb_error_msg("%u: no such job", jobnum);
9595 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9598 const char *status_string;
9600 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9601 for (job = G.job_list; job; job = job->next) {
9602 if (job->alive_cmds == job->stopped_cmds)
9603 status_string = "Stopped";
9605 status_string = "Running";
9607 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9609 return EXIT_SUCCESS;
9612 /* built-in 'fg' and 'bg' handler */
9613 static int FAST_FUNC builtin_fg_bg(char **argv)
9618 if (!G_interactive_fd)
9619 return EXIT_FAILURE;
9621 /* If they gave us no args, assume they want the last backgrounded task */
9623 for (pi = G.job_list; pi; pi = pi->next) {
9624 if (pi->jobid == G.last_jobid) {
9628 bb_error_msg("%s: no current job", argv[0]);
9629 return EXIT_FAILURE;
9632 pi = parse_jobspec(argv[1]);
9634 return EXIT_FAILURE;
9636 /* TODO: bash prints a string representation
9637 * of job being foregrounded (like "sleep 1 | cat") */
9638 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9639 /* Put the job into the foreground. */
9640 tcsetpgrp(G_interactive_fd, pi->pgrp);
9643 /* Restart the processes in the job */
9644 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9645 for (i = 0; i < pi->num_cmds; i++) {
9646 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9648 pi->stopped_cmds = 0;
9650 i = kill(- pi->pgrp, SIGCONT);
9652 if (errno == ESRCH) {
9653 delete_finished_bg_job(pi);
9654 return EXIT_SUCCESS;
9656 bb_perror_msg("kill (SIGCONT)");
9659 if (argv[0][0] == 'f') {
9661 return checkjobs_and_fg_shell(pi);
9663 return EXIT_SUCCESS;
9667 #if ENABLE_HUSH_KILL
9668 static int FAST_FUNC builtin_kill(char **argv)
9672 # if ENABLE_HUSH_JOB
9673 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9681 if (argv[i][0] != '%')
9684 * "kill %N" - job kill
9685 * Converting to pgrp / pid kill
9687 pi = parse_jobspec(argv[i]);
9689 /* Eat bad jobspec */
9693 argv[j - 1] = argv[j];
9700 * In jobs started under job control, we signal
9701 * entire process group by kill -PGRP_ID.
9702 * This happens, f.e., in interactive shell.
9704 * Otherwise, we signal each child via
9705 * kill PID1 PID2 PID3.
9707 * sh -c 'sleep 1|sleep 1 & kill %1'
9708 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9709 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9711 n = G_interactive_fd ? 1 : pi->num_cmds;
9712 dst = alloca(n * sizeof(int)*4);
9714 if (G_interactive_fd)
9715 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9716 else for (j = 0; j < n; j++) {
9717 struct command *cmd = &pi->cmds[j];
9718 /* Skip exited members of the job */
9722 * kill_main has matching code to expect
9723 * leading space. Needed to not confuse
9724 * negative pids with "kill -SIGNAL_NO" syntax
9726 dst += sprintf(dst, " %u", (int)cmd->pid);
9729 } while (argv[++i]);
9733 if (argv[1] || ret == 0) {
9734 ret = run_applet_main(argv, kill_main);
9736 /* else: ret = 1, "kill %bad_jobspec" case */
9741 #if ENABLE_HUSH_WAIT
9742 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9743 #if !ENABLE_HUSH_JOB
9744 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9746 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9753 if (!sigisemptyset(&G.pending_set))
9756 /* waitpid is not interruptible by SA_RESTARTed
9757 * signals which we use. Thus, this ugly dance:
9760 /* Make sure possible SIGCHLD is stored in kernel's
9761 * pending signal mask before we call waitpid.
9762 * Or else we may race with SIGCHLD, lose it,
9763 * and get stuck in sigsuspend...
9765 sigfillset(&oldset); /* block all signals, remember old set */
9766 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9768 if (!sigisemptyset(&G.pending_set)) {
9769 /* Crap! we raced with some signal! */
9773 /*errno = 0; - checkjobs does this */
9774 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9775 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9776 debug_printf_exec("checkjobs:%d\n", ret);
9779 int rcode = job_exited_or_stopped(waitfor_pipe);
9780 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9783 sigprocmask(SIG_SETMASK, &oldset, NULL);
9788 /* if ECHILD, there are no children (ret is -1 or 0) */
9789 /* if ret == 0, no children changed state */
9790 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9791 if (errno == ECHILD || ret) {
9793 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9795 sigprocmask(SIG_SETMASK, &oldset, NULL);
9798 /* Wait for SIGCHLD or any other signal */
9799 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9800 /* Note: sigsuspend invokes signal handler */
9801 sigsuspend(&oldset);
9803 sigprocmask(SIG_SETMASK, &oldset, NULL);
9805 /* So, did we get a signal? */
9806 sig = check_and_run_traps();
9807 if (sig /*&& sig != SIGCHLD - always true */) {
9811 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9816 static int FAST_FUNC builtin_wait(char **argv)
9821 argv = skip_dash_dash(argv);
9822 if (argv[0] == NULL) {
9823 /* Don't care about wait results */
9824 /* Note 1: must wait until there are no more children */
9825 /* Note 2: must be interruptible */
9827 * $ sleep 3 & sleep 6 & wait
9832 * $ sleep 3 & sleep 6 & wait
9836 * ^C <-- after ~4 sec from keyboard
9839 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9843 pid_t pid = bb_strtou(*argv, NULL, 10);
9844 if (errno || pid <= 0) {
9846 if (argv[0][0] == '%') {
9847 struct pipe *wait_pipe;
9848 ret = 127; /* bash compat for bad jobspecs */
9849 wait_pipe = parse_jobspec(*argv);
9851 ret = job_exited_or_stopped(wait_pipe);
9853 ret = wait_for_child_or_signal(wait_pipe, 0);
9855 /* else: parse_jobspec() already emitted error msg */
9859 /* mimic bash message */
9860 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9862 continue; /* bash checks all argv[] */
9865 /* Do we have such child? */
9866 ret = waitpid(pid, &status, WNOHANG);
9869 if (errno == ECHILD) {
9870 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9871 /* "wait $!" but last bg task has already exited. Try:
9872 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9873 * In bash it prints exitcode 0, then 3.
9874 * In dash, it is 127.
9876 /* ret = G.last_bg_pid_exitstatus - FIXME */
9878 /* Example: "wait 1". mimic bash message */
9879 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9883 bb_perror_msg("wait %s", *argv);
9886 continue; /* bash checks all argv[] */
9889 /* Yes, and it still runs */
9890 ret = wait_for_child_or_signal(NULL, pid);
9892 /* Yes, and it just exited */
9893 process_wait_result(NULL, pid, status);
9894 ret = WEXITSTATUS(status);
9895 if (WIFSIGNALED(status))
9896 ret = 128 + WTERMSIG(status);
9904 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9905 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9908 def = bb_strtou(argv[1], NULL, 10);
9909 if (errno || def < def_min || argv[2]) {
9910 bb_error_msg("%s: bad arguments", argv[0]);
9918 #if ENABLE_HUSH_LOOPS
9919 static int FAST_FUNC builtin_break(char **argv)
9922 if (G.depth_of_loop == 0) {
9923 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9924 /* if we came from builtin_continue(), need to undo "= 1" */
9925 G.flag_break_continue = 0;
9926 return EXIT_SUCCESS; /* bash compat */
9928 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9930 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9931 if (depth == UINT_MAX)
9932 G.flag_break_continue = BC_BREAK;
9933 if (G.depth_of_loop < depth)
9934 G.depth_break_continue = G.depth_of_loop;
9936 return EXIT_SUCCESS;
9939 static int FAST_FUNC builtin_continue(char **argv)
9941 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9942 return builtin_break(argv);
9946 #if ENABLE_HUSH_FUNCTIONS
9947 static int FAST_FUNC builtin_return(char **argv)
9951 if (G_flag_return_in_progress != -1) {
9952 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9953 return EXIT_FAILURE; /* bash compat */
9956 G_flag_return_in_progress = 1;
9959 * out of range: wraps around at 256, does not error out
9960 * non-numeric param:
9961 * f() { false; return qwe; }; f; echo $?
9962 * bash: return: qwe: numeric argument required <== we do this
9963 * 255 <== we also do this
9965 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
9970 #if ENABLE_HUSH_MEMLEAK
9971 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9976 # ifdef M_TRIM_THRESHOLD
9977 /* Optional. Reduces probability of false positives */
9980 /* Crude attempt to find where "free memory" starts,
9981 * sans fragmentation. */
9983 l = (unsigned long)p;
9986 if (l < (unsigned long)p) l = (unsigned long)p;
9992 struct mallinfo mi = mallinfo();
9993 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9994 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9998 if (!G.memleak_value)
9999 G.memleak_value = l;
10001 l -= G.memleak_value;
10008 /* Exitcode is "how many kilobytes we leaked since 1st call" */