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
272 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
273 // APPLET_ODDNAME:name main location suid_type help
274 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
275 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
277 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
278 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
279 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
280 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
282 /* -i (interactive) and -s (read stdin) are also accepted,
283 * but currently do nothing, therefore aren't shown in help.
284 * NOMMU-specific options are not meant to be used by users,
285 * therefore we don't show them either.
287 //usage:#define hush_trivial_usage
288 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
289 //usage:#define hush_full_usage "\n\n"
290 //usage: "Unix shell interpreter"
292 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
293 || defined(__APPLE__) \
295 # include <malloc.h> /* for malloc_trim */
298 /* #include <dmalloc.h> */
300 # include <fnmatch.h>
302 #include <sys/utsname.h> /* for setting $HOSTNAME */
304 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
306 #include "shell_common.h"
309 #if ENABLE_HUSH_RANDOM_SUPPORT
312 # define CLEAR_RANDOM_T(rnd) ((void)0)
314 #ifndef F_DUPFD_CLOEXEC
315 # define F_DUPFD_CLOEXEC F_DUPFD
318 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
322 /* So far, all bash compat is controlled by one config option */
323 /* Separate defines document which part of code implements what */
324 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
325 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
326 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
327 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
328 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
332 #define LEAK_HUNTING 0
333 #define BUILD_AS_NOMMU 0
334 /* Enable/disable sanity checks. Ok to enable in production,
335 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
336 * Keeping 1 for now even in released versions.
339 /* Slightly bigger (+200 bytes), but faster hush.
340 * So far it only enables a trick with counting SIGCHLDs and forks,
341 * which allows us to do fewer waitpid's.
342 * (we can detect a case where neither forks were done nor SIGCHLDs happened
343 * and therefore waitpid will return the same result as last time)
345 #define ENABLE_HUSH_FAST 0
346 /* TODO: implement simplified code for users which do not need ${var%...} ops
347 * So far ${var%...} ops are always enabled:
349 #define ENABLE_HUSH_DOLLAR_OPS 1
354 # undef USE_FOR_NOMMU
357 # define USE_FOR_NOMMU(...) __VA_ARGS__
358 # define USE_FOR_MMU(...)
361 #include "NUM_APPLETS.h"
363 /* STANDALONE does not make sense, and won't compile */
364 # undef CONFIG_FEATURE_SH_STANDALONE
365 # undef ENABLE_FEATURE_SH_STANDALONE
366 # undef IF_FEATURE_SH_STANDALONE
367 # undef IF_NOT_FEATURE_SH_STANDALONE
368 # define ENABLE_FEATURE_SH_STANDALONE 0
369 # define IF_FEATURE_SH_STANDALONE(...)
370 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
373 #if !ENABLE_HUSH_INTERACTIVE
374 # undef ENABLE_FEATURE_EDITING
375 # define ENABLE_FEATURE_EDITING 0
376 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
377 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
378 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
379 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
382 /* Do we support ANY keywords? */
383 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
384 # define HAS_KEYWORDS 1
385 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
386 # define IF_HAS_NO_KEYWORDS(...)
388 # define HAS_KEYWORDS 0
389 # define IF_HAS_KEYWORDS(...)
390 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
393 /* If you comment out one of these below, it will be #defined later
394 * to perform debug printfs to stderr: */
395 #define debug_printf(...) do {} while (0)
396 /* Finer-grained debug switches */
397 #define debug_printf_parse(...) do {} while (0)
398 #define debug_print_tree(a, b) do {} while (0)
399 #define debug_printf_exec(...) do {} while (0)
400 #define debug_printf_env(...) do {} while (0)
401 #define debug_printf_jobs(...) do {} while (0)
402 #define debug_printf_expand(...) do {} while (0)
403 #define debug_printf_varexp(...) do {} while (0)
404 #define debug_printf_glob(...) do {} while (0)
405 #define debug_printf_list(...) do {} while (0)
406 #define debug_printf_subst(...) do {} while (0)
407 #define debug_printf_clean(...) do {} while (0)
409 #define ERR_PTR ((void*)(long)1)
411 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
413 #define _SPECIAL_VARS_STR "_*@$!?#"
414 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
415 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
416 #if BASH_PATTERN_SUBST
417 /* Support / and // replace ops */
418 /* Note that // is stored as \ in "encoded" string representation */
419 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
420 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
421 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
423 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
424 # define VAR_SUBST_OPS "%#:-=+?"
425 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
428 #define SPECIAL_VAR_SYMBOL 3
432 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
434 /* This supports saving pointers malloced in vfork child,
435 * to be freed in the parent.
438 typedef struct nommu_save_t {
440 struct variable *old_vars;
442 char **argv_from_re_execing;
455 #if ENABLE_HUSH_LOOPS
462 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
467 /* three pseudo-keywords support contrived "case" syntax: */
468 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
469 RES_MATCH , /* "word)" */
470 RES_CASE_BODY, /* "this command is inside CASE" */
477 typedef struct o_string {
479 int length; /* position where data is appended */
482 /* At least some part of the string was inside '' or "",
483 * possibly empty one: word"", wo''rd etc. */
484 smallint has_quoted_part;
485 smallint has_empty_slot;
486 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
489 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
491 /* Protect newly added chars against globbing
492 * by prepending \ to *, ?, [, \ */
493 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
496 MAYBE_ASSIGNMENT = 0,
497 DEFINITELY_ASSIGNMENT = 1,
499 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
502 /* Used for initialization: o_string foo = NULL_O_STRING; */
503 #define NULL_O_STRING { NULL }
505 #ifndef debug_printf_parse
506 static const char *const assignment_flag[] = {
508 "DEFINITELY_ASSIGNMENT",
514 typedef struct in_str {
516 #if ENABLE_HUSH_INTERACTIVE
517 smallint promptmode; /* 0: PS1, 1: PS2 */
524 /* The descrip member of this structure is only used to make
525 * debugging output pretty */
526 static const struct {
528 signed char default_fd;
531 { O_RDONLY, 0, "<" },
532 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
533 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
534 { O_CREAT|O_RDWR, 1, "<>" },
535 { O_RDONLY, 0, "<<" },
536 /* Should not be needed. Bogus default_fd helps in debugging */
537 /* { O_RDONLY, 77, "<<" }, */
540 struct redir_struct {
541 struct redir_struct *next;
542 char *rd_filename; /* filename */
543 int rd_fd; /* fd to redirect */
544 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
546 smallint rd_type; /* (enum redir_type) */
547 /* note: for heredocs, rd_filename contains heredoc delimiter,
548 * and subsequently heredoc itself; and rd_dup is a bitmask:
549 * bit 0: do we need to trim leading tabs?
550 * bit 1: is heredoc quoted (<<'delim' syntax) ?
553 typedef enum redir_type {
555 REDIRECT_OVERWRITE = 1,
558 REDIRECT_HEREDOC = 4,
559 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
562 REDIRFD_SYNTAX_ERR = -2,
563 REDIRFD_TO_FILE = -1,
564 /* otherwise, rd_fd is redirected to rd_dup */
566 HEREDOC_SKIPTABS = 1,
572 pid_t pid; /* 0 if exited */
573 int assignment_cnt; /* how many argv[i] are assignments? */
574 smallint cmd_type; /* CMD_xxx */
576 #define CMD_SUBSHELL 1
578 /* used for "[[ EXPR ]]" */
579 # define CMD_SINGLEWORD_NOGLOB 2
581 #if ENABLE_HUSH_FUNCTIONS
582 # define CMD_FUNCDEF 3
585 smalluint cmd_exitcode;
586 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
589 char *group_as_string;
591 #if ENABLE_HUSH_FUNCTIONS
592 struct function *child_func;
593 /* This field is used to prevent a bug here:
594 * while...do f1() {a;}; f1; f1() {b;}; f1; done
595 * When we execute "f1() {a;}" cmd, we create new function and clear
596 * cmd->group, cmd->group_as_string, cmd->argv[0].
597 * When we execute "f1() {b;}", we notice that f1 exists,
598 * and that its "parent cmd" struct is still "alive",
599 * we put those fields back into cmd->xxx
600 * (struct function has ->parent_cmd ptr to facilitate that).
601 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
602 * Without this trick, loop would execute a;b;b;b;...
603 * instead of correct sequence a;b;a;b;...
604 * When command is freed, it severs the link
605 * (sets ->child_func->parent_cmd to NULL).
608 char **argv; /* command name and arguments */
609 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
610 * and on execution these are substituted with their values.
611 * Substitution can make _several_ words out of one argv[n]!
612 * Example: argv[0]=='.^C*^C.' here: echo .$*.
613 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
615 struct redir_struct *redirects; /* I/O redirections */
617 /* Is there anything in this command at all? */
618 #define IS_NULL_CMD(cmd) \
619 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
623 int num_cmds; /* total number of commands in pipe */
624 int alive_cmds; /* number of commands running (not exited) */
625 int stopped_cmds; /* number of commands alive, but stopped */
627 unsigned jobid; /* job number */
628 pid_t pgrp; /* process group ID for the job */
629 char *cmdtext; /* name of job */
631 struct command *cmds; /* array of commands in pipe */
632 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
633 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
634 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
636 typedef enum pipe_style {
642 /* Is there anything in this pipe at all? */
643 #define IS_NULL_PIPE(pi) \
644 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
646 /* This holds pointers to the various results of parsing */
647 struct parse_context {
648 /* linked list of pipes */
649 struct pipe *list_head;
650 /* last pipe (being constructed right now) */
652 /* last command in pipe (being constructed right now) */
653 struct command *command;
654 /* last redirect in command->redirects list */
655 struct redir_struct *pending_redirect;
661 smallint ctx_inverted; /* "! cmd | cmd" */
663 smallint ctx_dsemicolon; /* ";;" seen */
665 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
667 /* group we are enclosed in:
668 * example: "if pipe1; pipe2; then pipe3; fi"
669 * when we see "if" or "then", we malloc and copy current context,
670 * and make ->stack point to it. then we parse pipeN.
671 * when closing "then" / fi" / whatever is found,
672 * we move list_head into ->stack->command->group,
673 * copy ->stack into current context, and delete ->stack.
674 * (parsing of { list } and ( list ) doesn't use this method)
676 struct parse_context *stack;
680 /* On program start, environ points to initial environment.
681 * putenv adds new pointers into it, unsetenv removes them.
682 * Neither of these (de)allocates the strings.
683 * setenv allocates new strings in malloc space and does putenv,
684 * and thus setenv is unusable (leaky) for shell's purposes */
685 #define setenv(...) setenv_is_leaky_dont_use()
687 struct variable *next;
688 char *varstr; /* points to "name=" portion */
689 #if ENABLE_HUSH_LOCAL
690 unsigned func_nest_level;
692 int max_len; /* if > 0, name is part of initial env; else name is malloced */
693 smallint flg_export; /* putenv should be done on this var */
694 smallint flg_read_only;
702 #if ENABLE_HUSH_FUNCTIONS
704 struct function *next;
706 struct command *parent_cmd;
709 char *body_as_string;
715 /* set -/+o OPT support. (TODO: make it optional)
716 * bash supports the following opts:
727 * interactive-comments on
745 static const char o_opt_strings[] ALIGN1 =
748 #if ENABLE_HUSH_MODE_X
755 #if ENABLE_HUSH_MODE_X
763 struct FILE_list *next;
769 /* "Globals" within this file */
770 /* Sorted roughly by size (smaller offsets == smaller code) */
772 /* interactive_fd != 0 means we are an interactive shell.
773 * If we are, then saved_tty_pgrp can also be != 0, meaning
774 * that controlling tty is available. With saved_tty_pgrp == 0,
775 * job control still works, but terminal signals
776 * (^C, ^Z, ^Y, ^\) won't work at all, and background
777 * process groups can only be created with "cmd &".
778 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
779 * to give tty to the foreground process group,
780 * and will take it back when the group is stopped (^Z)
783 #if ENABLE_HUSH_INTERACTIVE
784 /* 'interactive_fd' is a fd# open to ctty, if we have one
785 * _AND_ if we decided to act interactively */
789 # define G_interactive_fd (G.interactive_fd)
791 # define G_interactive_fd 0
793 #if ENABLE_FEATURE_EDITING
794 line_input_t *line_input_state;
799 #if ENABLE_HUSH_RANDOM_SUPPORT
805 pid_t saved_tty_pgrp;
806 struct pipe *job_list;
807 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
809 # define G_saved_tty_pgrp 0
811 char o_opt[NUM_OPT_O];
812 #if ENABLE_HUSH_MODE_X
813 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
817 smallint flag_SIGINT;
818 #if ENABLE_HUSH_LOOPS
819 smallint flag_break_continue;
821 #if ENABLE_HUSH_FUNCTIONS
822 /* 0: outside of a function (or sourced file)
823 * -1: inside of a function, ok to use return builtin
824 * 1: return is invoked, skip all till end of func
826 smallint flag_return_in_progress;
827 # define G_flag_return_in_progress (G.flag_return_in_progress)
829 # define G_flag_return_in_progress 0
831 smallint exiting; /* used to prevent EXIT trap recursion */
832 /* These four support $?, $#, and $1 */
833 smalluint last_exitcode;
835 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
836 smalluint global_args_malloced;
837 # define G_global_args_malloced (G.global_args_malloced)
839 # define G_global_args_malloced 0
841 /* how many non-NULL argv's we have. NB: $# + 1 */
845 char *argv0_for_re_execing;
847 #if ENABLE_HUSH_LOOPS
848 unsigned depth_break_continue;
849 unsigned depth_of_loop;
853 struct variable *top_var;
854 char **expanded_assignments;
855 #if ENABLE_HUSH_FUNCTIONS
856 struct function *top_func;
857 # if ENABLE_HUSH_LOCAL
858 struct variable **shadowed_vars_pp;
859 unsigned func_nest_level;
862 /* Signal and trap handling */
864 unsigned count_SIGCHLD;
865 unsigned handled_SIGCHLD;
866 smallint we_have_children;
868 struct FILE_list *FILE_list;
869 /* Which signals have non-DFL handler (even with no traps set)?
870 * Set at the start to:
871 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
872 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
873 * The rest is cleared right before execv syscalls.
874 * Other than these two times, never modified.
876 unsigned special_sig_mask;
878 unsigned fatal_sig_mask;
879 # define G_fatal_sig_mask (G.fatal_sig_mask)
881 # define G_fatal_sig_mask 0
884 char **traps; /* char *traps[NSIG] */
885 # define G_traps G.traps
887 # define G_traps ((char**)NULL)
889 sigset_t pending_set;
890 #if ENABLE_HUSH_MEMLEAK
891 unsigned long memleak_value;
897 #if ENABLE_FEATURE_EDITING
898 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
901 #define G (*ptr_to_globals)
902 /* Not #defining name to G.name - this quickly gets unwieldy
903 * (too many defines). Also, I actually prefer to see when a variable
904 * is global, thus "G." prefix is a useful hint */
905 #define INIT_G() do { \
906 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
907 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
908 sigfillset(&G.sa.sa_mask); \
909 G.sa.sa_flags = SA_RESTART; \
913 /* Function prototypes for builtins */
914 static int builtin_cd(char **argv) FAST_FUNC;
916 static int builtin_echo(char **argv) FAST_FUNC;
918 static int builtin_eval(char **argv) FAST_FUNC;
919 static int builtin_exec(char **argv) FAST_FUNC;
920 static int builtin_exit(char **argv) FAST_FUNC;
921 #if ENABLE_HUSH_EXPORT
922 static int builtin_export(char **argv) FAST_FUNC;
925 static int builtin_fg_bg(char **argv) FAST_FUNC;
926 static int builtin_jobs(char **argv) FAST_FUNC;
929 static int builtin_help(char **argv) FAST_FUNC;
931 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
932 static int builtin_history(char **argv) FAST_FUNC;
934 #if ENABLE_HUSH_LOCAL
935 static int builtin_local(char **argv) FAST_FUNC;
937 #if ENABLE_HUSH_MEMLEAK
938 static int builtin_memleak(char **argv) FAST_FUNC;
940 #if ENABLE_HUSH_PRINTF
941 static int builtin_printf(char **argv) FAST_FUNC;
943 static int builtin_pwd(char **argv) FAST_FUNC;
945 static int builtin_read(char **argv) FAST_FUNC;
948 static int builtin_set(char **argv) FAST_FUNC;
950 static int builtin_shift(char **argv) FAST_FUNC;
951 static int builtin_source(char **argv) FAST_FUNC;
952 #if ENABLE_HUSH_TEST || BASH_TEST2
953 static int builtin_test(char **argv) FAST_FUNC;
956 static int builtin_trap(char **argv) FAST_FUNC;
959 static int builtin_type(char **argv) FAST_FUNC;
961 static int builtin_true(char **argv) FAST_FUNC;
962 #if ENABLE_HUSH_UMASK
963 static int builtin_umask(char **argv) FAST_FUNC;
965 #if ENABLE_HUSH_UNSET
966 static int builtin_unset(char **argv) FAST_FUNC;
969 static int builtin_kill(char **argv) FAST_FUNC;
972 static int builtin_wait(char **argv) FAST_FUNC;
974 #if ENABLE_HUSH_LOOPS
975 static int builtin_break(char **argv) FAST_FUNC;
976 static int builtin_continue(char **argv) FAST_FUNC;
978 #if ENABLE_HUSH_FUNCTIONS
979 static int builtin_return(char **argv) FAST_FUNC;
982 /* Table of built-in functions. They can be forked or not, depending on
983 * context: within pipes, they fork. As simple commands, they do not.
984 * When used in non-forking context, they can change global variables
985 * in the parent shell process. If forked, of course they cannot.
986 * For example, 'unset foo | whatever' will parse and run, but foo will
987 * still be set at the end. */
988 struct built_in_command {
990 int (*b_function)(char **argv) FAST_FUNC;
993 # define BLTIN(cmd, func, help) { cmd, func, help }
995 # define BLTIN(cmd, func, help) { cmd, func }
999 static const struct built_in_command bltins1[] = {
1000 BLTIN("." , builtin_source , "Run commands in file"),
1001 BLTIN(":" , builtin_true , NULL),
1003 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1005 #if ENABLE_HUSH_LOOPS
1006 BLTIN("break" , builtin_break , "Exit loop"),
1008 BLTIN("cd" , builtin_cd , "Change directory"),
1009 #if ENABLE_HUSH_LOOPS
1010 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1012 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1013 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1014 BLTIN("exit" , builtin_exit , NULL),
1015 #if ENABLE_HUSH_EXPORT
1016 BLTIN("export" , builtin_export , "Set environment variables"),
1019 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1021 #if ENABLE_HUSH_HELP
1022 BLTIN("help" , builtin_help , NULL),
1024 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1025 BLTIN("history" , builtin_history , "Show history"),
1028 BLTIN("jobs" , builtin_jobs , "List jobs"),
1030 #if ENABLE_HUSH_KILL
1031 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1033 #if ENABLE_HUSH_LOCAL
1034 BLTIN("local" , builtin_local , "Set local variables"),
1036 #if ENABLE_HUSH_MEMLEAK
1037 BLTIN("memleak" , builtin_memleak , NULL),
1039 #if ENABLE_HUSH_READ
1040 BLTIN("read" , builtin_read , "Input into variable"),
1042 #if ENABLE_HUSH_FUNCTIONS
1043 BLTIN("return" , builtin_return , "Return from function"),
1046 BLTIN("set" , builtin_set , "Set positional parameters"),
1048 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1050 BLTIN("source" , builtin_source , NULL),
1052 #if ENABLE_HUSH_TRAP
1053 BLTIN("trap" , builtin_trap , "Trap signals"),
1055 BLTIN("true" , builtin_true , NULL),
1056 #if ENABLE_HUSH_TYPE
1057 BLTIN("type" , builtin_type , "Show command type"),
1059 #if ENABLE_HUSH_ULIMIT
1060 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1062 #if ENABLE_HUSH_UMASK
1063 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1065 #if ENABLE_HUSH_UNSET
1066 BLTIN("unset" , builtin_unset , "Unset variables"),
1068 #if ENABLE_HUSH_WAIT
1069 BLTIN("wait" , builtin_wait , "Wait for process"),
1072 /* These builtins won't be used if we are on NOMMU and need to re-exec
1073 * (it's cheaper to run an external program in this case):
1075 static const struct built_in_command bltins2[] = {
1076 #if ENABLE_HUSH_TEST
1077 BLTIN("[" , builtin_test , NULL),
1080 BLTIN("[[" , builtin_test , NULL),
1082 #if ENABLE_HUSH_ECHO
1083 BLTIN("echo" , builtin_echo , NULL),
1085 #if ENABLE_HUSH_PRINTF
1086 BLTIN("printf" , builtin_printf , NULL),
1088 BLTIN("pwd" , builtin_pwd , NULL),
1089 #if ENABLE_HUSH_TEST
1090 BLTIN("test" , builtin_test , NULL),
1098 /* prevent disasters with G.debug_indent < 0 */
1099 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1100 # define debug_enter() (G.debug_indent++)
1101 # define debug_leave() (G.debug_indent--)
1103 # define indent() ((void)0)
1104 # define debug_enter() ((void)0)
1105 # define debug_leave() ((void)0)
1108 #ifndef debug_printf
1109 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1112 #ifndef debug_printf_parse
1113 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1116 #ifndef debug_printf_exec
1117 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1120 #ifndef debug_printf_env
1121 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1124 #ifndef debug_printf_jobs
1125 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1126 # define DEBUG_JOBS 1
1128 # define DEBUG_JOBS 0
1131 #ifndef debug_printf_expand
1132 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1133 # define DEBUG_EXPAND 1
1135 # define DEBUG_EXPAND 0
1138 #ifndef debug_printf_varexp
1139 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1142 #ifndef debug_printf_glob
1143 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1144 # define DEBUG_GLOB 1
1146 # define DEBUG_GLOB 0
1149 #ifndef debug_printf_list
1150 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1153 #ifndef debug_printf_subst
1154 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1157 #ifndef debug_printf_clean
1158 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1159 # define DEBUG_CLEAN 1
1161 # define DEBUG_CLEAN 0
1165 static void debug_print_strings(const char *prefix, char **vv)
1168 fdprintf(2, "%s:\n", prefix);
1170 fdprintf(2, " '%s'\n", *vv++);
1173 # define debug_print_strings(prefix, vv) ((void)0)
1177 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1180 static void *xxmalloc(int lineno, size_t size)
1182 void *ptr = xmalloc((size + 0xff) & ~0xff);
1183 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1186 static void *xxrealloc(int lineno, void *ptr, size_t size)
1188 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1189 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1192 static char *xxstrdup(int lineno, const char *str)
1194 char *ptr = xstrdup(str);
1195 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1198 static void xxfree(void *ptr)
1200 fdprintf(2, "free %p\n", ptr);
1203 # define xmalloc(s) xxmalloc(__LINE__, s)
1204 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1205 # define xstrdup(s) xxstrdup(__LINE__, s)
1206 # define free(p) xxfree(p)
1210 /* Syntax and runtime errors. They always abort scripts.
1211 * In interactive use they usually discard unparsed and/or unexecuted commands
1212 * and return to the prompt.
1213 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1216 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1217 # define syntax_error(lineno, msg) syntax_error(msg)
1218 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1219 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1220 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1221 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1224 static void die_if_script(unsigned lineno, const char *fmt, ...)
1229 bb_error_msg("hush.c:%u", lineno);
1232 bb_verror_msg(fmt, p, NULL);
1234 if (!G_interactive_fd)
1238 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1241 bb_error_msg("syntax error: %s", msg);
1243 bb_error_msg("syntax error");
1246 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1248 bb_error_msg("syntax error at '%s'", msg);
1251 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1253 bb_error_msg("syntax error: unterminated %s", s);
1256 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1258 char msg[2] = { ch, '\0' };
1259 syntax_error_unterm_str(lineno, msg);
1262 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1268 bb_error_msg("hush.c:%u", lineno);
1270 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1274 # undef die_if_script
1275 # undef syntax_error
1276 # undef syntax_error_at
1277 # undef syntax_error_unterm_ch
1278 # undef syntax_error_unterm_str
1279 # undef syntax_error_unexpected_ch
1281 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1282 # define syntax_error(msg) syntax_error(__LINE__, msg)
1283 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1284 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1285 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1286 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1290 #if ENABLE_HUSH_INTERACTIVE
1291 static void cmdedit_update_prompt(void);
1293 # define cmdedit_update_prompt() ((void)0)
1297 /* Utility functions
1299 /* Replace each \x with x in place, return ptr past NUL. */
1300 static char *unbackslash(char *src)
1302 char *dst = src = strchrnul(src, '\\');
1306 if ((*dst++ = *src++) == '\0')
1312 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1333 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1334 v[count1 + count2] = NULL;
1337 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1341 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1343 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1344 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1347 #define add_strings_to_strings(strings, add, need_to_dup) \
1348 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1351 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1352 static char **add_string_to_strings(char **strings, char *add)
1357 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1360 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1362 char **ptr = add_string_to_strings(strings, add);
1363 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1366 #define add_string_to_strings(strings, add) \
1367 xx_add_string_to_strings(__LINE__, strings, add)
1370 static void free_strings(char **strings)
1385 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1387 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1388 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1390 /* fd was not open? */
1400 /* Manipulating the list of open FILEs */
1401 static FILE *remember_FILE(FILE *fp)
1404 struct FILE_list *n = xmalloc(sizeof(*n));
1405 n->next = G.FILE_list;
1409 close_on_exec_on(n->fd);
1413 static void fclose_and_forget(FILE *fp)
1415 struct FILE_list **pp = &G.FILE_list;
1417 struct FILE_list *cur = *pp;
1418 if (cur->fp == fp) {
1427 static int save_FILEs_on_redirect(int fd)
1429 struct FILE_list *fl = G.FILE_list;
1432 /* We use it only on script files, they are all CLOEXEC */
1433 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1440 static void restore_redirected_FILEs(void)
1442 struct FILE_list *fl = G.FILE_list;
1444 int should_be = fileno(fl->fp);
1445 if (fl->fd != should_be) {
1446 xmove_fd(fl->fd, should_be);
1452 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1453 static void close_all_FILE_list(void)
1455 struct FILE_list *fl = G.FILE_list;
1457 /* fclose would also free FILE object.
1458 * It is disastrous if we share memory with a vforked parent.
1459 * I'm not sure we never come here after vfork.
1460 * Therefore just close fd, nothing more.
1462 /*fclose(fl->fp); - unsafe */
1470 /* Helpers for setting new $n and restoring them back
1472 typedef struct save_arg_t {
1476 IF_HUSH_SET(smallint sv_g_malloced;)
1479 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1481 sv->sv_argv0 = argv[0];
1482 sv->sv_g_argv = G.global_argv;
1483 sv->sv_g_argc = G.global_argc;
1484 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1486 argv[0] = G.global_argv[0]; /* retain $0 */
1487 G.global_argv = argv;
1488 IF_HUSH_SET(G.global_args_malloced = 0;)
1490 G.global_argc = 1 + string_array_len(argv + 1);
1493 static void restore_G_args(save_arg_t *sv, char **argv)
1496 if (G.global_args_malloced) {
1497 /* someone ran "set -- arg1 arg2 ...", undo */
1498 char **pp = G.global_argv;
1499 while (*++pp) /* note: does not free $0 */
1501 free(G.global_argv);
1504 argv[0] = sv->sv_argv0;
1505 G.global_argv = sv->sv_g_argv;
1506 G.global_argc = sv->sv_g_argc;
1507 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1511 /* Basic theory of signal handling in shell
1512 * ========================================
1513 * This does not describe what hush does, rather, it is current understanding
1514 * what it _should_ do. If it doesn't, it's a bug.
1515 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1517 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1518 * is finished or backgrounded. It is the same in interactive and
1519 * non-interactive shells, and is the same regardless of whether
1520 * a user trap handler is installed or a shell special one is in effect.
1521 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1522 * backgrounds (i.e. stops) or kills all members of currently running
1525 * Wait builtin is interruptible by signals for which user trap is set
1526 * or by SIGINT in interactive shell.
1528 * Trap handlers will execute even within trap handlers. (right?)
1530 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1531 * except for handlers set to '' (empty string).
1533 * If job control is off, backgrounded commands ("cmd &")
1534 * have SIGINT, SIGQUIT set to SIG_IGN.
1536 * Commands which are run in command substitution ("`cmd`")
1537 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1539 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1540 * by the shell from its parent.
1542 * Signals which differ from SIG_DFL action
1543 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1546 * SIGTERM (interactive): ignore
1547 * SIGHUP (interactive):
1548 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1549 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1550 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1551 * that all pipe members are stopped. Try this in bash:
1552 * while :; do :; done - ^Z does not background it
1553 * (while :; do :; done) - ^Z backgrounds it
1554 * SIGINT (interactive): wait for last pipe, ignore the rest
1555 * of the command line, show prompt. NB: ^C does not send SIGINT
1556 * to interactive shell while shell is waiting for a pipe,
1557 * since shell is bg'ed (is not in foreground process group).
1558 * Example 1: this waits 5 sec, but does not execute ls:
1559 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1560 * Example 2: this does not wait and does not execute ls:
1561 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1562 * Example 3: this does not wait 5 sec, but executes ls:
1563 * "sleep 5; ls -l" + press ^C
1564 * Example 4: this does not wait and does not execute ls:
1565 * "sleep 5 & wait; ls -l" + press ^C
1567 * (What happens to signals which are IGN on shell start?)
1568 * (What happens with signal mask on shell start?)
1570 * Old implementation
1571 * ==================
1572 * We use in-kernel pending signal mask to determine which signals were sent.
1573 * We block all signals which we don't want to take action immediately,
1574 * i.e. we block all signals which need to have special handling as described
1575 * above, and all signals which have traps set.
1576 * After each pipe execution, we extract any pending signals via sigtimedwait()
1579 * unsigned special_sig_mask: a mask of such "special" signals
1580 * sigset_t blocked_set: current blocked signal set
1583 * clear bit in blocked_set unless it is also in special_sig_mask
1584 * "trap 'cmd' SIGxxx":
1585 * set bit in blocked_set (even if 'cmd' is '')
1586 * after [v]fork, if we plan to be a shell:
1587 * unblock signals with special interactive handling
1588 * (child shell is not interactive),
1589 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1590 * after [v]fork, if we plan to exec:
1591 * POSIX says fork clears pending signal mask in child - no need to clear it.
1592 * Restore blocked signal set to one inherited by shell just prior to exec.
1594 * Note: as a result, we do not use signal handlers much. The only uses
1595 * are to count SIGCHLDs
1596 * and to restore tty pgrp on signal-induced exit.
1599 * Standard says "When a subshell is entered, traps that are not being ignored
1600 * are set to the default actions". bash interprets it so that traps which
1601 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1603 * Problem: the above approach makes it unwieldy to catch signals while
1604 * we are in read builtin, or while we read commands from stdin:
1605 * masked signals are not visible!
1607 * New implementation
1608 * ==================
1609 * We record each signal we are interested in by installing signal handler
1610 * for them - a bit like emulating kernel pending signal mask in userspace.
1611 * We are interested in: signals which need to have special handling
1612 * as described above, and all signals which have traps set.
1613 * Signals are recorded in pending_set.
1614 * After each pipe execution, we extract any pending signals
1617 * unsigned special_sig_mask: a mask of shell-special signals.
1618 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1619 * char *traps[sig] if trap for sig is set (even if it's '').
1620 * sigset_t pending_set: set of sigs we received.
1623 * if sig is in special_sig_mask, set handler back to:
1624 * record_pending_signo, or to IGN if it's a tty stop signal
1625 * if sig is in fatal_sig_mask, set handler back to sigexit.
1626 * else: set handler back to SIG_DFL
1627 * "trap 'cmd' SIGxxx":
1628 * set handler to record_pending_signo.
1630 * set handler to SIG_IGN.
1631 * after [v]fork, if we plan to be a shell:
1632 * set signals with special interactive handling to SIG_DFL
1633 * (because child shell is not interactive),
1634 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1635 * after [v]fork, if we plan to exec:
1636 * POSIX says fork clears pending signal mask in child - no need to clear it.
1638 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1639 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1642 * Standard says "When a subshell is entered, traps that are not being ignored
1643 * are set to the default actions". bash interprets it so that traps which
1644 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1647 SPECIAL_INTERACTIVE_SIGS = 0
1652 SPECIAL_JOBSTOP_SIGS = 0
1661 static void record_pending_signo(int sig)
1663 sigaddset(&G.pending_set, sig);
1664 #if ENABLE_HUSH_FAST
1665 if (sig == SIGCHLD) {
1667 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1672 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1674 struct sigaction old_sa;
1676 /* We could use signal() to install handlers... almost:
1677 * except that we need to mask ALL signals while handlers run.
1678 * I saw signal nesting in strace, race window isn't small.
1679 * SA_RESTART is also needed, but in Linux, signal()
1680 * sets SA_RESTART too.
1682 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1683 /* sigfillset(&G.sa.sa_mask); - already done */
1684 /* G.sa.sa_flags = SA_RESTART; - already done */
1685 G.sa.sa_handler = handler;
1686 sigaction(sig, &G.sa, &old_sa);
1687 return old_sa.sa_handler;
1690 static void hush_exit(int exitcode) NORETURN;
1692 static void restore_ttypgrp_and__exit(void) NORETURN;
1693 static void restore_ttypgrp_and__exit(void)
1695 /* xfunc has failed! die die die */
1696 /* no EXIT traps, this is an escape hatch! */
1698 hush_exit(xfunc_error_retval);
1703 /* Needed only on some libc:
1704 * It was observed that on exit(), fgetc'ed buffered data
1705 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1706 * With the net effect that even after fork(), not vfork(),
1707 * exit() in NOEXECed applet in "sh SCRIPT":
1708 * noexec_applet_here
1709 * echo END_OF_SCRIPT
1710 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1711 * This makes "echo END_OF_SCRIPT" executed twice.
1712 * Similar problems can be seen with die_if_script() -> xfunc_die()
1713 * and in `cmd` handling.
1714 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1716 static void fflush_and__exit(void) NORETURN;
1717 static void fflush_and__exit(void)
1720 _exit(xfunc_error_retval);
1723 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1724 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1725 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1726 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1728 /* Restores tty foreground process group, and exits.
1729 * May be called as signal handler for fatal signal
1730 * (will resend signal to itself, producing correct exit state)
1731 * or called directly with -EXITCODE.
1732 * We also call it if xfunc is exiting.
1734 static void sigexit(int sig) NORETURN;
1735 static void sigexit(int sig)
1737 /* Careful: we can end up here after [v]fork. Do not restore
1738 * tty pgrp then, only top-level shell process does that */
1739 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1740 /* Disable all signals: job control, SIGPIPE, etc.
1741 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1743 sigprocmask_allsigs(SIG_BLOCK);
1744 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1747 /* Not a signal, just exit */
1751 kill_myself_with_sig(sig); /* does not return */
1755 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1756 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1760 static sighandler_t pick_sighandler(unsigned sig)
1762 sighandler_t handler = SIG_DFL;
1763 if (sig < sizeof(unsigned)*8) {
1764 unsigned sigmask = (1 << sig);
1768 if (G_fatal_sig_mask & sigmask)
1772 /* sig has special handling? */
1773 if (G.special_sig_mask & sigmask) {
1774 handler = record_pending_signo;
1775 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1776 * in order to ignore them: they will be raised
1777 * in an endless loop when we try to do some
1778 * terminal ioctls! We do have to _ignore_ these.
1780 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1787 /* Restores tty foreground process group, and exits. */
1788 static void hush_exit(int exitcode)
1790 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1791 save_history(G.line_input_state);
1795 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1797 /* argv[0] is unused */
1798 argv[1] = G_traps[0];
1800 G.exiting = 1; /* prevent EXIT trap recursion */
1801 /* Note: G_traps[0] is not cleared!
1802 * "trap" will still show it, if executed
1807 #if ENABLE_FEATURE_CLEAN_UP
1809 struct variable *cur_var;
1810 if (G.cwd != bb_msg_unknown)
1812 cur_var = G.top_var;
1814 struct variable *tmp = cur_var;
1815 if (!cur_var->max_len)
1816 free(cur_var->varstr);
1817 cur_var = cur_var->next;
1825 sigexit(- (exitcode & 0xff));
1832 //TODO: return a mask of ALL handled sigs?
1833 static int check_and_run_traps(void)
1840 if (sigisemptyset(&G.pending_set))
1845 if (sigismember(&G.pending_set, sig)) {
1846 sigdelset(&G.pending_set, sig);
1849 } while (sig < NSIG);
1852 if (G_traps && G_traps[sig]) {
1853 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1854 if (G_traps[sig][0]) {
1855 /* We have user-defined handler */
1856 smalluint save_rcode;
1858 /* argv[0] is unused */
1859 argv[1] = G_traps[sig];
1861 save_rcode = G.last_exitcode;
1863 //FIXME: shouldn't it be set to 128 + sig instead?
1864 G.last_exitcode = save_rcode;
1866 } /* else: "" trap, ignoring signal */
1869 /* not a trap: special action */
1872 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1879 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1880 /* bash is observed to signal whole process groups,
1881 * not individual processes */
1882 for (job = G.job_list; job; job = job->next) {
1885 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1886 if (kill(- job->pgrp, SIGHUP) == 0)
1887 kill(- job->pgrp, SIGCONT);
1892 #if ENABLE_HUSH_FAST
1894 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1896 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1898 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1899 * This simplifies wait builtin a bit.
1903 default: /* ignored: */
1904 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1905 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1907 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1908 * Example: wait is not interrupted by TERM
1909 * in interactive shell, because TERM is ignored.
1918 static const char *get_cwd(int force)
1920 if (force || G.cwd == NULL) {
1921 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1922 * we must not try to free(bb_msg_unknown) */
1923 if (G.cwd == bb_msg_unknown)
1925 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1927 G.cwd = bb_msg_unknown;
1934 * Shell and environment variable support
1936 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1938 struct variable **pp;
1939 struct variable *cur;
1942 while ((cur = *pp) != NULL) {
1943 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1950 static const char* FAST_FUNC get_local_var_value(const char *name)
1952 struct variable **vpp;
1953 unsigned len = strlen(name);
1955 if (G.expanded_assignments) {
1956 char **cpp = G.expanded_assignments;
1959 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1960 return cp + len + 1;
1965 vpp = get_ptr_to_local_var(name, len);
1967 return (*vpp)->varstr + len + 1;
1969 if (strcmp(name, "PPID") == 0)
1970 return utoa(G.root_ppid);
1971 // bash compat: UID? EUID?
1972 #if ENABLE_HUSH_RANDOM_SUPPORT
1973 if (strcmp(name, "RANDOM") == 0)
1974 return utoa(next_random(&G.random_gen));
1979 /* str holds "NAME=VAL" and is expected to be malloced.
1980 * We take ownership of it.
1982 * 0: do not change export flag
1983 * (if creating new variable, flag will be 0)
1984 * 1: set export flag and putenv the variable
1985 * -1: clear export flag and unsetenv the variable
1986 * flg_read_only is set only when we handle -R var=val
1988 #if !BB_MMU && ENABLE_HUSH_LOCAL
1989 /* all params are used */
1990 #elif BB_MMU && ENABLE_HUSH_LOCAL
1991 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1992 set_local_var(str, flg_export, local_lvl)
1993 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1994 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1995 set_local_var(str, flg_export)
1996 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1997 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1998 set_local_var(str, flg_export, flg_read_only)
2000 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2002 struct variable **var_pp;
2003 struct variable *cur;
2004 char *free_me = NULL;
2008 eq_sign = strchr(str, '=');
2009 if (!eq_sign) { /* not expected to ever happen? */
2014 name_len = eq_sign - str + 1; /* including '=' */
2015 var_pp = &G.top_var;
2016 while ((cur = *var_pp) != NULL) {
2017 if (strncmp(cur->varstr, str, name_len) != 0) {
2018 var_pp = &cur->next;
2022 /* We found an existing var with this name */
2023 if (cur->flg_read_only) {
2027 bb_error_msg("%s: readonly variable", str);
2031 if (flg_export == -1) { // "&& cur->flg_export" ?
2032 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2037 #if ENABLE_HUSH_LOCAL
2038 if (cur->func_nest_level < local_lvl) {
2039 /* New variable is declared as local,
2040 * and existing one is global, or local
2041 * from enclosing function.
2042 * Remove and save old one: */
2043 *var_pp = cur->next;
2044 cur->next = *G.shadowed_vars_pp;
2045 *G.shadowed_vars_pp = cur;
2046 /* bash 3.2.33(1) and exported vars:
2048 * # f() { local z=a; env | grep ^z; }
2054 if (cur->flg_export)
2059 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2064 if (cur->max_len != 0) {
2065 if (cur->max_len >= strlen(str)) {
2066 /* This one is from startup env, reuse space */
2067 strcpy(cur->varstr, str);
2072 goto set_str_and_exp;
2074 /* max_len == 0 signifies "malloced" var, which we can
2075 * (and have to) free. But we can't free(cur->varstr) here:
2076 * if cur->flg_export is 1, it is in the environment.
2077 * We should either unsetenv+free, or wait until putenv,
2078 * then putenv(new)+free(old).
2080 free_me = cur->varstr;
2081 goto set_str_and_exp;
2084 /* Not found - create new variable struct */
2085 cur = xzalloc(sizeof(*cur));
2086 #if ENABLE_HUSH_LOCAL
2087 cur->func_nest_level = local_lvl;
2089 cur->next = *var_pp;
2095 cur->flg_read_only = flg_read_only;
2098 if (flg_export == 1)
2099 cur->flg_export = 1;
2100 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2101 cmdedit_update_prompt();
2102 if (cur->flg_export) {
2103 if (flg_export == -1) {
2104 cur->flg_export = 0;
2105 /* unsetenv was already done */
2108 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2109 i = putenv(cur->varstr);
2110 /* only now we can free old exported malloced string */
2119 /* Used at startup and after each cd */
2120 static void set_pwd_var(int exp)
2122 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2123 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2126 static int unset_local_var_len(const char *name, int name_len)
2128 struct variable *cur;
2129 struct variable **var_pp;
2132 return EXIT_SUCCESS;
2133 var_pp = &G.top_var;
2134 while ((cur = *var_pp) != NULL) {
2135 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2136 if (cur->flg_read_only) {
2137 bb_error_msg("%s: readonly variable", name);
2138 return EXIT_FAILURE;
2140 *var_pp = cur->next;
2141 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2142 bb_unsetenv(cur->varstr);
2143 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2144 cmdedit_update_prompt();
2148 return EXIT_SUCCESS;
2150 var_pp = &cur->next;
2152 return EXIT_SUCCESS;
2155 #if ENABLE_HUSH_UNSET
2156 static int unset_local_var(const char *name)
2158 return unset_local_var_len(name, strlen(name));
2162 static void unset_vars(char **strings)
2170 const char *eq = strchrnul(*v, '=');
2171 unset_local_var_len(*v, (int)(eq - *v));
2177 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2178 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2180 char *var = xasprintf("%s=%s", name, val);
2181 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2187 * Helpers for "var1=val1 var2=val2 cmd" feature
2189 static void add_vars(struct variable *var)
2191 struct variable *next;
2195 var->next = G.top_var;
2197 if (var->flg_export) {
2198 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2199 putenv(var->varstr);
2201 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2207 static struct variable *set_vars_and_save_old(char **strings)
2210 struct variable *old = NULL;
2216 struct variable *var_p;
2217 struct variable **var_pp;
2220 eq = strchr(*s, '=');
2222 var_pp = get_ptr_to_local_var(*s, eq - *s);
2224 /* Remove variable from global linked list */
2226 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2227 *var_pp = var_p->next;
2228 /* Add it to returned list */
2232 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2243 static void reinit_unicode_for_hush(void)
2245 /* Unicode support should be activated even if LANG is set
2246 * _during_ shell execution, not only if it was set when
2247 * shell was started. Therefore, re-check LANG every time:
2249 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2250 || ENABLE_UNICODE_USING_LOCALE
2252 const char *s = get_local_var_value("LC_ALL");
2253 if (!s) s = get_local_var_value("LC_CTYPE");
2254 if (!s) s = get_local_var_value("LANG");
2260 * in_str support (strings, and "strings" read from files).
2263 #if ENABLE_HUSH_INTERACTIVE
2264 /* To test correct lineedit/interactive behavior, type from command line:
2270 * It exercises a lot of corner cases.
2272 static void cmdedit_update_prompt(void)
2274 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2275 G.PS1 = get_local_var_value("PS1");
2278 G.PS2 = get_local_var_value("PS2");
2285 static const char *setup_prompt_string(int promptmode)
2287 const char *prompt_str;
2288 debug_printf("setup_prompt_string %d ", promptmode);
2289 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2290 /* Set up the prompt */
2291 if (promptmode == 0) { /* PS1 */
2293 /* bash uses $PWD value, even if it is set by user.
2294 * It uses current dir only if PWD is unset.
2295 * We always use current dir. */
2296 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2301 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2302 debug_printf("prompt_str '%s'\n", prompt_str);
2305 static int get_user_input(struct in_str *i)
2308 const char *prompt_str;
2310 prompt_str = setup_prompt_string(i->promptmode);
2311 # if ENABLE_FEATURE_EDITING
2313 reinit_unicode_for_hush();
2314 if (G.flag_SIGINT) {
2315 /* There was ^C'ed, make it look prettier: */
2319 /* buglet: SIGINT will not make new prompt to appear _at once_,
2320 * only after <Enter>. (^C works immediately) */
2321 r = read_line_input(G.line_input_state, prompt_str,
2322 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2325 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2327 write(STDOUT_FILENO, "^C", 2);
2330 check_and_run_traps();
2331 if (r != 0 && !G.flag_SIGINT)
2333 /* ^C or SIGINT: repeat */
2334 G.last_exitcode = 128 + SIGINT;
2337 /* EOF/error detected */
2339 i->peek_buf[0] = r = EOF;
2342 i->p = G.user_input_buf;
2343 return (unsigned char)*i->p++;
2347 if (i->last_char == '\0' || i->last_char == '\n') {
2348 /* Why check_and_run_traps here? Try this interactively:
2349 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2350 * $ <[enter], repeatedly...>
2351 * Without check_and_run_traps, handler never runs.
2353 check_and_run_traps();
2354 fputs(prompt_str, stdout);
2357 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2359 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2360 * no ^C masking happens during fgetc, no special code for ^C:
2361 * it generates SIGINT as usual.
2363 check_and_run_traps();
2365 G.last_exitcode = 128 + SIGINT;
2372 /* This is the magic location that prints prompts
2373 * and gets data back from the user */
2374 static int fgetc_interactive(struct in_str *i)
2377 /* If it's interactive stdin, get new line. */
2378 if (G_interactive_fd && i->file == stdin) {
2379 /* Returns first char (or EOF), the rest is in i->p[] */
2380 ch = get_user_input(i);
2381 i->promptmode = 1; /* PS2 */
2383 /* Not stdin: script file, sourced file, etc */
2384 do ch = fgetc(i->file); while (ch == '\0');
2389 static inline int fgetc_interactive(struct in_str *i)
2392 do ch = fgetc(i->file); while (ch == '\0');
2395 #endif /* INTERACTIVE */
2397 static int i_getch(struct in_str *i)
2402 /* string-based in_str */
2403 ch = (unsigned char)*i->p;
2412 /* FILE-based in_str */
2414 #if ENABLE_FEATURE_EDITING
2415 /* This can be stdin, check line editing char[] buffer */
2416 if (i->p && *i->p != '\0') {
2417 ch = (unsigned char)*i->p++;
2421 /* peek_buf[] is an int array, not char. Can contain EOF. */
2422 ch = i->peek_buf[0];
2424 int ch2 = i->peek_buf[1];
2425 i->peek_buf[0] = ch2;
2426 if (ch2 == 0) /* very likely, avoid redundant write */
2432 ch = fgetc_interactive(i);
2434 debug_printf("file_get: got '%c' %d\n", ch, ch);
2439 static int i_peek(struct in_str *i)
2444 /* string-based in_str */
2445 /* Doesn't report EOF on NUL. None of the callers care. */
2446 return (unsigned char)*i->p;
2449 /* FILE-based in_str */
2451 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2452 /* This can be stdin, check line editing char[] buffer */
2453 if (i->p && *i->p != '\0')
2454 return (unsigned char)*i->p;
2456 /* peek_buf[] is an int array, not char. Can contain EOF. */
2457 ch = i->peek_buf[0];
2461 /* Need to get a new char */
2462 ch = fgetc_interactive(i);
2463 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2465 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2466 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2472 i->peek_buf[0] = ch;
2473 /*i->peek_buf[1] = 0; - already is */
2477 /* Only ever called if i_peek() was called, and did not return EOF.
2478 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2479 * not end-of-line. Therefore we never need to read a new editing line here.
2481 static int i_peek2(struct in_str *i)
2485 /* There are two cases when i->p[] buffer exists.
2486 * (1) it's a string in_str.
2487 * (2) It's a file, and we have a saved line editing buffer.
2488 * In both cases, we know that i->p[0] exists and not NUL, and
2489 * the peek2 result is in i->p[1].
2492 return (unsigned char)i->p[1];
2494 /* Now we know it is a file-based in_str. */
2496 /* peek_buf[] is an int array, not char. Can contain EOF. */
2497 /* Is there 2nd char? */
2498 ch = i->peek_buf[1];
2500 /* We did not read it yet, get it now */
2501 do ch = fgetc(i->file); while (ch == '\0');
2502 i->peek_buf[1] = ch;
2505 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2509 static void setup_file_in_str(struct in_str *i, FILE *f)
2511 memset(i, 0, sizeof(*i));
2512 /* i->promptmode = 0; - PS1 (memset did it) */
2517 static void setup_string_in_str(struct in_str *i, const char *s)
2519 memset(i, 0, sizeof(*i));
2520 /* i->promptmode = 0; - PS1 (memset did it) */
2521 /*i->file = NULL */;
2529 #define B_CHUNK (32 * sizeof(char*))
2531 static void o_reset_to_empty_unquoted(o_string *o)
2534 o->has_quoted_part = 0;
2539 static void o_free(o_string *o)
2542 memset(o, 0, sizeof(*o));
2545 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2550 static void o_grow_by(o_string *o, int len)
2552 if (o->length + len > o->maxlen) {
2553 o->maxlen += (2 * len) | (B_CHUNK-1);
2554 o->data = xrealloc(o->data, 1 + o->maxlen);
2558 static void o_addchr(o_string *o, int ch)
2560 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2561 if (o->length < o->maxlen) {
2562 /* likely. avoid o_grow_by() call */
2564 o->data[o->length] = ch;
2566 o->data[o->length] = '\0';
2574 /* Valid only if we know o_string is not empty */
2575 static void o_delchr(o_string *o)
2578 o->data[o->length] = '\0';
2582 static void o_addblock(o_string *o, const char *str, int len)
2585 memcpy(&o->data[o->length], str, len);
2587 o->data[o->length] = '\0';
2590 static void o_addstr(o_string *o, const char *str)
2592 o_addblock(o, str, strlen(str));
2596 static void nommu_addchr(o_string *o, int ch)
2602 # define nommu_addchr(o, str) ((void)0)
2605 static void o_addstr_with_NUL(o_string *o, const char *str)
2607 o_addblock(o, str, strlen(str) + 1);
2611 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2612 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2613 * Apparently, on unquoted $v bash still does globbing
2614 * ("v='*.txt'; echo $v" prints all .txt files),
2615 * but NOT brace expansion! Thus, there should be TWO independent
2616 * quoting mechanisms on $v expansion side: one protects
2617 * $v from brace expansion, and other additionally protects "$v" against globbing.
2618 * We have only second one.
2621 #if ENABLE_HUSH_BRACE_EXPANSION
2622 # define MAYBE_BRACES "{}"
2624 # define MAYBE_BRACES ""
2627 /* My analysis of quoting semantics tells me that state information
2628 * is associated with a destination, not a source.
2630 static void o_addqchr(o_string *o, int ch)
2633 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2638 o->data[o->length] = '\\';
2641 o->data[o->length] = ch;
2643 o->data[o->length] = '\0';
2646 static void o_addQchr(o_string *o, int ch)
2649 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2650 && strchr("*?[\\" MAYBE_BRACES, ch)
2653 o->data[o->length] = '\\';
2657 o->data[o->length] = ch;
2659 o->data[o->length] = '\0';
2662 static void o_addqblock(o_string *o, const char *str, int len)
2667 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2668 if (ordinary_cnt > len) /* paranoia */
2670 o_addblock(o, str, ordinary_cnt);
2671 if (ordinary_cnt == len)
2672 return; /* NUL is already added by o_addblock */
2673 str += ordinary_cnt;
2674 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2678 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2680 o->data[o->length] = '\\';
2684 o->data[o->length] = ch;
2687 o->data[o->length] = '\0';
2690 static void o_addQblock(o_string *o, const char *str, int len)
2692 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2693 o_addblock(o, str, len);
2696 o_addqblock(o, str, len);
2699 static void o_addQstr(o_string *o, const char *str)
2701 o_addQblock(o, str, strlen(str));
2704 /* A special kind of o_string for $VAR and `cmd` expansion.
2705 * It contains char* list[] at the beginning, which is grown in 16 element
2706 * increments. Actual string data starts at the next multiple of 16 * (char*).
2707 * list[i] contains an INDEX (int!) into this string data.
2708 * It means that if list[] needs to grow, data needs to be moved higher up
2709 * but list[i]'s need not be modified.
2710 * NB: remembering how many list[i]'s you have there is crucial.
2711 * o_finalize_list() operation post-processes this structure - calculates
2712 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2714 #if DEBUG_EXPAND || DEBUG_GLOB
2715 static void debug_print_list(const char *prefix, o_string *o, int n)
2717 char **list = (char**)o->data;
2718 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2722 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2723 prefix, list, n, string_start, o->length, o->maxlen,
2724 !!(o->o_expflags & EXP_FLAG_GLOB),
2726 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2729 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2730 o->data + (int)(uintptr_t)list[i] + string_start,
2731 o->data + (int)(uintptr_t)list[i] + string_start);
2735 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2737 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2741 # define debug_print_list(prefix, o, n) ((void)0)
2744 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2745 * in list[n] so that it points past last stored byte so far.
2746 * It returns n+1. */
2747 static int o_save_ptr_helper(o_string *o, int n)
2749 char **list = (char**)o->data;
2753 if (!o->has_empty_slot) {
2754 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2755 string_len = o->length - string_start;
2756 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2757 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2758 /* list[n] points to string_start, make space for 16 more pointers */
2759 o->maxlen += 0x10 * sizeof(list[0]);
2760 o->data = xrealloc(o->data, o->maxlen + 1);
2761 list = (char**)o->data;
2762 memmove(list + n + 0x10, list + n, string_len);
2763 o->length += 0x10 * sizeof(list[0]);
2765 debug_printf_list("list[%d]=%d string_start=%d\n",
2766 n, string_len, string_start);
2769 /* We have empty slot at list[n], reuse without growth */
2770 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2771 string_len = o->length - string_start;
2772 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2773 n, string_len, string_start);
2774 o->has_empty_slot = 0;
2776 o->has_quoted_part = 0;
2777 list[n] = (char*)(uintptr_t)string_len;
2781 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2782 static int o_get_last_ptr(o_string *o, int n)
2784 char **list = (char**)o->data;
2785 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2787 return ((int)(uintptr_t)list[n-1]) + string_start;
2790 #if ENABLE_HUSH_BRACE_EXPANSION
2791 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2792 * first, it processes even {a} (no commas), second,
2793 * I didn't manage to make it return strings when they don't match
2794 * existing files. Need to re-implement it.
2798 static int glob_needed(const char *s)
2807 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2813 /* Return pointer to next closing brace or to comma */
2814 static const char *next_brace_sub(const char *cp)
2818 while (*cp != '\0') {
2825 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2831 return *cp != '\0' ? cp : NULL;
2833 /* Recursive brace globber. Note: may garble pattern[]. */
2834 static int glob_brace(char *pattern, o_string *o, int n)
2836 char *new_pattern_buf;
2843 debug_printf_glob("glob_brace('%s')\n", pattern);
2849 if (*begin == '{') {
2850 /* Find the first sub-pattern and at the same time
2851 * find the rest after the closing brace */
2852 next = next_brace_sub(begin);
2854 /* An illegal expression */
2858 /* "{abc}" with no commas - illegal
2859 * brace expr, disregard and skip it */
2865 if (*begin == '\\' && begin[1] != '\0')
2869 debug_printf_glob("begin:%s\n", begin);
2870 debug_printf_glob("next:%s\n", next);
2872 /* Now find the end of the whole brace expression */
2874 while (*rest != '}') {
2875 rest = next_brace_sub(rest);
2877 /* An illegal expression */
2880 debug_printf_glob("rest:%s\n", rest);
2882 rest_len = strlen(++rest) + 1;
2884 /* We are sure the brace expression is well-formed */
2886 /* Allocate working buffer large enough for our work */
2887 new_pattern_buf = xmalloc(strlen(pattern));
2889 /* We have a brace expression. BEGIN points to the opening {,
2890 * NEXT points past the terminator of the first element, and REST
2891 * points past the final }. We will accumulate result names from
2892 * recursive runs for each brace alternative in the buffer using
2897 /* Construct the new glob expression */
2900 mempcpy(new_pattern_buf,
2901 /* We know the prefix for all sub-patterns */
2902 pattern, begin - pattern),
2906 /* Note: glob_brace() may garble new_pattern_buf[].
2907 * That's why we re-copy prefix every time (1st memcpy above).
2909 n = glob_brace(new_pattern_buf, o, n);
2911 /* We saw the last entry */
2915 next = next_brace_sub(next);
2917 free(new_pattern_buf);
2925 memset(&globdata, 0, sizeof(globdata));
2926 gr = glob(pattern, 0, NULL, &globdata);
2927 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2929 if (gr == GLOB_NOMATCH) {
2930 globfree(&globdata);
2931 /* NB: garbles parameter */
2932 unbackslash(pattern);
2933 o_addstr_with_NUL(o, pattern);
2934 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2935 return o_save_ptr_helper(o, n);
2937 if (gr == GLOB_NOSPACE)
2938 bb_error_msg_and_die(bb_msg_memory_exhausted);
2939 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2940 * but we didn't specify it. Paranoia again. */
2941 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2943 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2944 char **argv = globdata.gl_pathv;
2946 o_addstr_with_NUL(o, *argv);
2947 n = o_save_ptr_helper(o, n);
2953 globfree(&globdata);
2957 /* Performs globbing on last list[],
2958 * saving each result as a new list[].
2960 static int perform_glob(o_string *o, int n)
2962 char *pattern, *copy;
2964 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2966 return o_save_ptr_helper(o, n);
2967 pattern = o->data + o_get_last_ptr(o, n);
2968 debug_printf_glob("glob pattern '%s'\n", pattern);
2969 if (!glob_needed(pattern)) {
2970 /* unbackslash last string in o in place, fix length */
2971 o->length = unbackslash(pattern) - o->data;
2972 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2973 return o_save_ptr_helper(o, n);
2976 copy = xstrdup(pattern);
2977 /* "forget" pattern in o */
2978 o->length = pattern - o->data;
2979 n = glob_brace(copy, o, n);
2982 debug_print_list("perform_glob returning", o, n);
2986 #else /* !HUSH_BRACE_EXPANSION */
2989 static int glob_needed(const char *s)
2998 if (*s == '*' || *s == '[' || *s == '?')
3004 /* Performs globbing on last list[],
3005 * saving each result as a new list[].
3007 static int perform_glob(o_string *o, int n)
3013 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3015 return o_save_ptr_helper(o, n);
3016 pattern = o->data + o_get_last_ptr(o, n);
3017 debug_printf_glob("glob pattern '%s'\n", pattern);
3018 if (!glob_needed(pattern)) {
3020 /* unbackslash last string in o in place, fix length */
3021 o->length = unbackslash(pattern) - o->data;
3022 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3023 return o_save_ptr_helper(o, n);
3026 memset(&globdata, 0, sizeof(globdata));
3027 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3028 * If we glob "*.\*" and don't find anything, we need
3029 * to fall back to using literal "*.*", but GLOB_NOCHECK
3030 * will return "*.\*"!
3032 gr = glob(pattern, 0, NULL, &globdata);
3033 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3035 if (gr == GLOB_NOMATCH) {
3036 globfree(&globdata);
3039 if (gr == GLOB_NOSPACE)
3040 bb_error_msg_and_die(bb_msg_memory_exhausted);
3041 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3042 * but we didn't specify it. Paranoia again. */
3043 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3045 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3046 char **argv = globdata.gl_pathv;
3047 /* "forget" pattern in o */
3048 o->length = pattern - o->data;
3050 o_addstr_with_NUL(o, *argv);
3051 n = o_save_ptr_helper(o, n);
3057 globfree(&globdata);
3059 debug_print_list("perform_glob returning", o, n);
3063 #endif /* !HUSH_BRACE_EXPANSION */
3065 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3066 * Otherwise, just finish current list[] and start new */
3067 static int o_save_ptr(o_string *o, int n)
3069 if (o->o_expflags & EXP_FLAG_GLOB) {
3070 /* If o->has_empty_slot, list[n] was already globbed
3071 * (if it was requested back then when it was filled)
3072 * so don't do that again! */
3073 if (!o->has_empty_slot)
3074 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3076 return o_save_ptr_helper(o, n);
3079 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3080 static char **o_finalize_list(o_string *o, int n)
3085 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3087 debug_print_list("finalized", o, n);
3088 debug_printf_expand("finalized n:%d\n", n);
3089 list = (char**)o->data;
3090 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3094 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3099 static void free_pipe_list(struct pipe *pi);
3101 /* Returns pi->next - next pipe in the list */
3102 static struct pipe *free_pipe(struct pipe *pi)
3107 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3108 for (i = 0; i < pi->num_cmds; i++) {
3109 struct command *command;
3110 struct redir_struct *r, *rnext;
3112 command = &pi->cmds[i];
3113 debug_printf_clean(" command %d:\n", i);
3114 if (command->argv) {
3118 for (a = 0, p = command->argv; *p; a++, p++) {
3119 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3122 free_strings(command->argv);
3123 //command->argv = NULL;
3125 /* not "else if": on syntax error, we may have both! */
3126 if (command->group) {
3127 debug_printf_clean(" begin group (cmd_type:%d)\n",
3129 free_pipe_list(command->group);
3130 debug_printf_clean(" end group\n");
3131 //command->group = NULL;
3133 /* else is crucial here.
3134 * If group != NULL, child_func is meaningless */
3135 #if ENABLE_HUSH_FUNCTIONS
3136 else if (command->child_func) {
3137 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3138 command->child_func->parent_cmd = NULL;
3142 free(command->group_as_string);
3143 //command->group_as_string = NULL;
3145 for (r = command->redirects; r; r = rnext) {
3146 debug_printf_clean(" redirect %d%s",
3147 r->rd_fd, redir_table[r->rd_type].descrip);
3148 /* guard against the case >$FOO, where foo is unset or blank */
3149 if (r->rd_filename) {
3150 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3151 free(r->rd_filename);
3152 //r->rd_filename = NULL;
3154 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3158 //command->redirects = NULL;
3160 free(pi->cmds); /* children are an array, they get freed all at once */
3164 //pi->cmdtext = NULL;
3172 static void free_pipe_list(struct pipe *pi)
3176 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3178 debug_printf_clean("pipe followup code %d\n", pi->followup);
3184 /*** Parsing routines ***/
3186 #ifndef debug_print_tree
3187 static void debug_print_tree(struct pipe *pi, int lvl)
3189 static const char *const PIPE[] = {
3195 static const char *RES[] = {
3196 [RES_NONE ] = "NONE" ,
3199 [RES_THEN ] = "THEN" ,
3200 [RES_ELIF ] = "ELIF" ,
3201 [RES_ELSE ] = "ELSE" ,
3204 # if ENABLE_HUSH_LOOPS
3205 [RES_FOR ] = "FOR" ,
3206 [RES_WHILE] = "WHILE",
3207 [RES_UNTIL] = "UNTIL",
3209 [RES_DONE ] = "DONE" ,
3211 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3214 # if ENABLE_HUSH_CASE
3215 [RES_CASE ] = "CASE" ,
3216 [RES_CASE_IN ] = "CASE_IN" ,
3217 [RES_MATCH] = "MATCH",
3218 [RES_CASE_BODY] = "CASE_BODY",
3219 [RES_ESAC ] = "ESAC" ,
3221 [RES_XXXX ] = "XXXX" ,
3222 [RES_SNTX ] = "SNTX" ,
3224 static const char *const CMDTYPE[] = {
3228 # if ENABLE_HUSH_FUNCTIONS
3237 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3238 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3240 while (prn < pi->num_cmds) {
3241 struct command *command = &pi->cmds[prn];
3242 char **argv = command->argv;
3244 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3246 command->assignment_cnt);
3247 if (command->group) {
3248 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3249 CMDTYPE[command->cmd_type],
3252 , " group_as_string:", command->group_as_string
3257 debug_print_tree(command->group, lvl+1);
3261 if (argv) while (*argv) {
3262 fdprintf(2, " '%s'", *argv);
3272 #endif /* debug_print_tree */
3274 static struct pipe *new_pipe(void)
3277 pi = xzalloc(sizeof(struct pipe));
3278 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3282 /* Command (member of a pipe) is complete, or we start a new pipe
3283 * if ctx->command is NULL.
3284 * No errors possible here.
3286 static int done_command(struct parse_context *ctx)
3288 /* The command is really already in the pipe structure, so
3289 * advance the pipe counter and make a new, null command. */
3290 struct pipe *pi = ctx->pipe;
3291 struct command *command = ctx->command;
3293 #if 0 /* Instead we emit error message at run time */
3294 if (ctx->pending_redirect) {
3295 /* For example, "cmd >" (no filename to redirect to) */
3296 die_if_script("syntax error: %s", "invalid redirect");
3297 ctx->pending_redirect = NULL;
3302 if (IS_NULL_CMD(command)) {
3303 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3307 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3308 //debug_print_tree(ctx->list_head, 20);
3310 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3313 /* Only real trickiness here is that the uncommitted
3314 * command structure is not counted in pi->num_cmds. */
3315 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3316 ctx->command = command = &pi->cmds[pi->num_cmds];
3318 memset(command, 0, sizeof(*command));
3319 return pi->num_cmds; /* used only for 0/nonzero check */
3322 static void done_pipe(struct parse_context *ctx, pipe_style type)
3326 debug_printf_parse("done_pipe entered, followup %d\n", type);
3327 /* Close previous command */
3328 not_null = done_command(ctx);
3329 ctx->pipe->followup = type;
3331 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3332 ctx->ctx_inverted = 0;
3333 ctx->pipe->res_word = ctx->ctx_res_w;
3336 /* Without this check, even just <enter> on command line generates
3337 * tree of three NOPs (!). Which is harmless but annoying.
3338 * IOW: it is safe to do it unconditionally. */
3341 || ctx->ctx_res_w == RES_FI
3343 #if ENABLE_HUSH_LOOPS
3344 || ctx->ctx_res_w == RES_DONE
3345 || ctx->ctx_res_w == RES_FOR
3346 || ctx->ctx_res_w == RES_IN
3348 #if ENABLE_HUSH_CASE
3349 || ctx->ctx_res_w == RES_ESAC
3353 debug_printf_parse("done_pipe: adding new pipe: "
3354 "not_null:%d ctx->ctx_res_w:%d\n",
3355 not_null, ctx->ctx_res_w);
3357 ctx->pipe->next = new_p;
3359 /* RES_THEN, RES_DO etc are "sticky" -
3360 * they remain set for pipes inside if/while.
3361 * This is used to control execution.
3362 * RES_FOR and RES_IN are NOT sticky (needed to support
3363 * cases where variable or value happens to match a keyword):
3365 #if ENABLE_HUSH_LOOPS
3366 if (ctx->ctx_res_w == RES_FOR
3367 || ctx->ctx_res_w == RES_IN)
3368 ctx->ctx_res_w = RES_NONE;
3370 #if ENABLE_HUSH_CASE
3371 if (ctx->ctx_res_w == RES_MATCH)
3372 ctx->ctx_res_w = RES_CASE_BODY;
3373 if (ctx->ctx_res_w == RES_CASE)
3374 ctx->ctx_res_w = RES_CASE_IN;
3376 ctx->command = NULL; /* trick done_command below */
3377 /* Create the memory for command, roughly:
3378 * ctx->pipe->cmds = new struct command;
3379 * ctx->command = &ctx->pipe->cmds[0];
3382 //debug_print_tree(ctx->list_head, 10);
3384 debug_printf_parse("done_pipe return\n");
3387 static void initialize_context(struct parse_context *ctx)
3389 memset(ctx, 0, sizeof(*ctx));
3390 ctx->pipe = ctx->list_head = new_pipe();
3391 /* Create the memory for command, roughly:
3392 * ctx->pipe->cmds = new struct command;
3393 * ctx->command = &ctx->pipe->cmds[0];
3398 /* If a reserved word is found and processed, parse context is modified
3399 * and 1 is returned.
3402 struct reserved_combo {
3405 unsigned char assignment_flag;
3409 FLAG_END = (1 << RES_NONE ),
3411 FLAG_IF = (1 << RES_IF ),
3412 FLAG_THEN = (1 << RES_THEN ),
3413 FLAG_ELIF = (1 << RES_ELIF ),
3414 FLAG_ELSE = (1 << RES_ELSE ),
3415 FLAG_FI = (1 << RES_FI ),
3417 # if ENABLE_HUSH_LOOPS
3418 FLAG_FOR = (1 << RES_FOR ),
3419 FLAG_WHILE = (1 << RES_WHILE),
3420 FLAG_UNTIL = (1 << RES_UNTIL),
3421 FLAG_DO = (1 << RES_DO ),
3422 FLAG_DONE = (1 << RES_DONE ),
3423 FLAG_IN = (1 << RES_IN ),
3425 # if ENABLE_HUSH_CASE
3426 FLAG_MATCH = (1 << RES_MATCH),
3427 FLAG_ESAC = (1 << RES_ESAC ),
3429 FLAG_START = (1 << RES_XXXX ),
3432 static const struct reserved_combo* match_reserved_word(o_string *word)
3434 /* Mostly a list of accepted follow-up reserved words.
3435 * FLAG_END means we are done with the sequence, and are ready
3436 * to turn the compound list into a command.
3437 * FLAG_START means the word must start a new compound list.
3439 static const struct reserved_combo reserved_list[] = {
3441 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3442 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3443 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3444 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3445 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3446 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3448 # if ENABLE_HUSH_LOOPS
3449 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3450 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3451 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3452 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3453 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3454 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3456 # if ENABLE_HUSH_CASE
3457 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3458 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3461 const struct reserved_combo *r;
3463 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3464 if (strcmp(word->data, r->literal) == 0)
3469 /* Return 0: not a keyword, 1: keyword
3471 static int reserved_word(o_string *word, struct parse_context *ctx)
3473 # if ENABLE_HUSH_CASE
3474 static const struct reserved_combo reserved_match = {
3475 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3478 const struct reserved_combo *r;
3480 if (word->has_quoted_part)
3482 r = match_reserved_word(word);
3486 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3487 # if ENABLE_HUSH_CASE
3488 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3489 /* "case word IN ..." - IN part starts first MATCH part */
3490 r = &reserved_match;
3493 if (r->flag == 0) { /* '!' */
3494 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3495 syntax_error("! ! command");
3496 ctx->ctx_res_w = RES_SNTX;
3498 ctx->ctx_inverted = 1;
3501 if (r->flag & FLAG_START) {
3502 struct parse_context *old;
3504 old = xmalloc(sizeof(*old));
3505 debug_printf_parse("push stack %p\n", old);
3506 *old = *ctx; /* physical copy */
3507 initialize_context(ctx);
3509 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3510 syntax_error_at(word->data);
3511 ctx->ctx_res_w = RES_SNTX;
3514 /* "{...} fi" is ok. "{...} if" is not
3516 * if { echo foo; } then { echo bar; } fi */
3517 if (ctx->command->group)
3518 done_pipe(ctx, PIPE_SEQ);
3521 ctx->ctx_res_w = r->res;
3522 ctx->old_flag = r->flag;
3523 word->o_assignment = r->assignment_flag;
3524 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3526 if (ctx->old_flag & FLAG_END) {
3527 struct parse_context *old;
3529 done_pipe(ctx, PIPE_SEQ);
3530 debug_printf_parse("pop stack %p\n", ctx->stack);
3532 old->command->group = ctx->list_head;
3533 old->command->cmd_type = CMD_NORMAL;
3535 /* At this point, the compound command's string is in
3536 * ctx->as_string... except for the leading keyword!
3537 * Consider this example: "echo a | if true; then echo a; fi"
3538 * ctx->as_string will contain "true; then echo a; fi",
3539 * with "if " remaining in old->as_string!
3543 int len = old->as_string.length;
3544 /* Concatenate halves */
3545 o_addstr(&old->as_string, ctx->as_string.data);
3546 o_free_unsafe(&ctx->as_string);
3547 /* Find where leading keyword starts in first half */
3548 str = old->as_string.data + len;
3549 if (str > old->as_string.data)
3550 str--; /* skip whitespace after keyword */
3551 while (str > old->as_string.data && isalpha(str[-1]))
3553 /* Ugh, we're done with this horrid hack */
3554 old->command->group_as_string = xstrdup(str);
3555 debug_printf_parse("pop, remembering as:'%s'\n",
3556 old->command->group_as_string);
3559 *ctx = *old; /* physical copy */
3564 #endif /* HAS_KEYWORDS */
3566 /* Word is complete, look at it and update parsing context.
3567 * Normal return is 0. Syntax errors return 1.
3568 * Note: on return, word is reset, but not o_free'd!
3570 static int done_word(o_string *word, struct parse_context *ctx)
3572 struct command *command = ctx->command;
3574 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3575 if (word->length == 0 && !word->has_quoted_part) {
3576 debug_printf_parse("done_word return 0: true null, ignored\n");
3580 if (ctx->pending_redirect) {
3581 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3582 * only if run as "bash", not "sh" */
3583 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3585 * ...the word that follows the redirection operator
3586 * shall be subjected to tilde expansion, parameter expansion,
3587 * command substitution, arithmetic expansion, and quote
3588 * removal. Pathname expansion shall not be performed
3589 * on the word by a non-interactive shell; an interactive
3590 * shell may perform it, but shall do so only when
3591 * the expansion would result in one word."
3593 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3594 /* Cater for >\file case:
3595 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3596 * Same with heredocs:
3597 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3599 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3600 unbackslash(ctx->pending_redirect->rd_filename);
3601 /* Is it <<"HEREDOC"? */
3602 if (word->has_quoted_part) {
3603 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3606 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3607 ctx->pending_redirect = NULL;
3610 # if ENABLE_HUSH_CASE
3611 if (ctx->ctx_dsemicolon
3612 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3614 /* already done when ctx_dsemicolon was set to 1: */
3615 /* ctx->ctx_res_w = RES_MATCH; */
3616 ctx->ctx_dsemicolon = 0;
3619 if (!command->argv /* if it's the first word... */
3620 # if ENABLE_HUSH_LOOPS
3621 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3622 && ctx->ctx_res_w != RES_IN
3624 # if ENABLE_HUSH_CASE
3625 && ctx->ctx_res_w != RES_CASE
3628 int reserved = reserved_word(word, ctx);
3629 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3631 o_reset_to_empty_unquoted(word);
3632 debug_printf_parse("done_word return %d\n",
3633 (ctx->ctx_res_w == RES_SNTX));
3634 return (ctx->ctx_res_w == RES_SNTX);
3637 if (strcmp(word->data, "[[") == 0) {
3638 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3644 if (command->group) {
3645 /* "{ echo foo; } echo bar" - bad */
3646 syntax_error_at(word->data);
3647 debug_printf_parse("done_word return 1: syntax error, "
3648 "groups and arglists don't mix\n");
3652 /* If this word wasn't an assignment, next ones definitely
3653 * can't be assignments. Even if they look like ones. */
3654 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3655 && word->o_assignment != WORD_IS_KEYWORD
3657 word->o_assignment = NOT_ASSIGNMENT;
3659 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3660 command->assignment_cnt++;
3661 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3663 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3664 word->o_assignment = MAYBE_ASSIGNMENT;
3666 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3668 if (word->has_quoted_part
3669 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3670 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3671 /* (otherwise it's known to be not empty and is already safe) */
3673 /* exclude "$@" - it can expand to no word despite "" */
3674 char *p = word->data;
3675 while (p[0] == SPECIAL_VAR_SYMBOL
3676 && (p[1] & 0x7f) == '@'
3677 && p[2] == SPECIAL_VAR_SYMBOL
3682 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3683 debug_print_strings("word appended to argv", command->argv);
3686 #if ENABLE_HUSH_LOOPS
3687 if (ctx->ctx_res_w == RES_FOR) {
3688 if (word->has_quoted_part
3689 || !is_well_formed_var_name(command->argv[0], '\0')
3691 /* bash says just "not a valid identifier" */
3692 syntax_error("not a valid identifier in for");
3695 /* Force FOR to have just one word (variable name) */
3696 /* NB: basically, this makes hush see "for v in ..."
3697 * syntax as if it is "for v; in ...". FOR and IN become
3698 * two pipe structs in parse tree. */
3699 done_pipe(ctx, PIPE_SEQ);
3702 #if ENABLE_HUSH_CASE
3703 /* Force CASE to have just one word */
3704 if (ctx->ctx_res_w == RES_CASE) {
3705 done_pipe(ctx, PIPE_SEQ);
3709 o_reset_to_empty_unquoted(word);
3711 debug_printf_parse("done_word return 0\n");
3716 /* Peek ahead in the input to find out if we have a "&n" construct,
3717 * as in "2>&1", that represents duplicating a file descriptor.
3719 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3720 * REDIRFD_SYNTAX_ERR if syntax error,
3721 * REDIRFD_TO_FILE if no & was seen,
3722 * or the number found.
3725 #define parse_redir_right_fd(as_string, input) \
3726 parse_redir_right_fd(input)
3728 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3734 return REDIRFD_TO_FILE;
3736 ch = i_getch(input); /* get the & */
3737 nommu_addchr(as_string, ch);
3740 ch = i_getch(input);
3741 nommu_addchr(as_string, ch);
3742 return REDIRFD_CLOSE;
3746 while (ch != EOF && isdigit(ch)) {
3747 d = d*10 + (ch-'0');
3749 ch = i_getch(input);
3750 nommu_addchr(as_string, ch);
3755 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3757 bb_error_msg("ambiguous redirect");
3758 return REDIRFD_SYNTAX_ERR;
3761 /* Return code is 0 normal, 1 if a syntax error is detected
3763 static int parse_redirect(struct parse_context *ctx,
3766 struct in_str *input)
3768 struct command *command = ctx->command;
3769 struct redir_struct *redir;
3770 struct redir_struct **redirp;
3773 dup_num = REDIRFD_TO_FILE;
3774 if (style != REDIRECT_HEREDOC) {
3775 /* Check for a '>&1' type redirect */
3776 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3777 if (dup_num == REDIRFD_SYNTAX_ERR)
3780 int ch = i_peek(input);
3781 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3782 if (dup_num) { /* <<-... */
3783 ch = i_getch(input);
3784 nommu_addchr(&ctx->as_string, ch);
3789 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3790 int ch = i_peek(input);
3792 /* >|FILE redirect ("clobbering" >).
3793 * Since we do not support "set -o noclobber" yet,
3794 * >| and > are the same for now. Just eat |.
3796 ch = i_getch(input);
3797 nommu_addchr(&ctx->as_string, ch);
3801 /* Create a new redir_struct and append it to the linked list */
3802 redirp = &command->redirects;
3803 while ((redir = *redirp) != NULL) {
3804 redirp = &(redir->next);
3806 *redirp = redir = xzalloc(sizeof(*redir));
3807 /* redir->next = NULL; */
3808 /* redir->rd_filename = NULL; */
3809 redir->rd_type = style;
3810 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3812 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3813 redir_table[style].descrip);
3815 redir->rd_dup = dup_num;
3816 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3817 /* Erik had a check here that the file descriptor in question
3818 * is legit; I postpone that to "run time"
3819 * A "-" representation of "close me" shows up as a -3 here */
3820 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3821 redir->rd_fd, redir->rd_dup);
3823 #if 0 /* Instead we emit error message at run time */
3824 if (ctx->pending_redirect) {
3825 /* For example, "cmd > <file" */
3826 die_if_script("syntax error: %s", "invalid redirect");
3829 /* Set ctx->pending_redirect, so we know what to do at the
3830 * end of the next parsed word. */
3831 ctx->pending_redirect = redir;
3836 /* If a redirect is immediately preceded by a number, that number is
3837 * supposed to tell which file descriptor to redirect. This routine
3838 * looks for such preceding numbers. In an ideal world this routine
3839 * needs to handle all the following classes of redirects...
3840 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3841 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3842 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3843 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3845 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3847 * ... If n is quoted, the number shall not be recognized as part of
3848 * the redirection expression. For example:
3850 * writes the character 2 into file a"
3851 * We are getting it right by setting ->has_quoted_part on any \<char>
3853 * A -1 return means no valid number was found,
3854 * the caller should use the appropriate default for this redirection.
3856 static int redirect_opt_num(o_string *o)
3860 if (o->data == NULL)
3862 num = bb_strtou(o->data, NULL, 10);
3863 if (errno || num < 0)
3865 o_reset_to_empty_unquoted(o);
3870 #define fetch_till_str(as_string, input, word, skip_tabs) \
3871 fetch_till_str(input, word, skip_tabs)
3873 static char *fetch_till_str(o_string *as_string,
3874 struct in_str *input,
3878 o_string heredoc = NULL_O_STRING;
3880 int prev = 0; /* not \ */
3886 ch = i_getch(input);
3888 nommu_addchr(as_string, ch);
3889 if ((ch == '\n' || ch == EOF)
3890 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3892 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3893 heredoc.data[past_EOL] = '\0';
3894 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3895 return heredoc.data;
3897 while (ch == '\n') {
3898 o_addchr(&heredoc, ch);
3901 past_EOL = heredoc.length;
3903 ch = i_getch(input);
3905 nommu_addchr(as_string, ch);
3906 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3910 o_free_unsafe(&heredoc);
3913 o_addchr(&heredoc, ch);
3914 nommu_addchr(as_string, ch);
3915 if (prev == '\\' && ch == '\\')
3916 /* Correctly handle foo\\<eol> (not a line cont.) */
3917 prev = 0; /* not \ */
3923 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3924 * and load them all. There should be exactly heredoc_cnt of them.
3926 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3928 struct pipe *pi = ctx->list_head;
3930 while (pi && heredoc_cnt) {
3932 struct command *cmd = pi->cmds;
3934 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3936 cmd->argv ? cmd->argv[0] : "NONE");
3937 for (i = 0; i < pi->num_cmds; i++) {
3938 struct redir_struct *redir = cmd->redirects;
3940 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3941 i, cmd->argv ? cmd->argv[0] : "NONE");
3943 if (redir->rd_type == REDIRECT_HEREDOC) {
3946 redir->rd_type = REDIRECT_HEREDOC2;
3947 /* redir->rd_dup is (ab)used to indicate <<- */
3948 p = fetch_till_str(&ctx->as_string, input,
3949 redir->rd_filename, redir->rd_dup);
3951 syntax_error("unexpected EOF in here document");
3954 free(redir->rd_filename);
3955 redir->rd_filename = p;
3958 redir = redir->next;
3965 /* Should be 0. If it isn't, it's a parse error */
3967 bb_error_msg_and_die("heredoc BUG 2");
3973 static int run_list(struct pipe *pi);
3975 #define parse_stream(pstring, input, end_trigger) \
3976 parse_stream(input, end_trigger)
3978 static struct pipe *parse_stream(char **pstring,
3979 struct in_str *input,
3983 #if !ENABLE_HUSH_FUNCTIONS
3984 #define parse_group(dest, ctx, input, ch) \
3985 parse_group(ctx, input, ch)
3987 static int parse_group(o_string *dest, struct parse_context *ctx,
3988 struct in_str *input, int ch)
3990 /* dest contains characters seen prior to ( or {.
3991 * Typically it's empty, but for function defs,
3992 * it contains function name (without '()'). */
3993 struct pipe *pipe_list;
3995 struct command *command = ctx->command;
3997 debug_printf_parse("parse_group entered\n");
3998 #if ENABLE_HUSH_FUNCTIONS
3999 if (ch == '(' && !dest->has_quoted_part) {
4001 if (done_word(dest, ctx))
4004 goto skip; /* (... */
4005 if (command->argv[1]) { /* word word ... (... */
4006 syntax_error_unexpected_ch('(');
4009 /* it is "word(..." or "word (..." */
4011 ch = i_getch(input);
4012 while (ch == ' ' || ch == '\t');
4014 syntax_error_unexpected_ch(ch);
4017 nommu_addchr(&ctx->as_string, ch);
4019 ch = i_getch(input);
4020 while (ch == ' ' || ch == '\t' || ch == '\n');
4022 syntax_error_unexpected_ch(ch);
4025 nommu_addchr(&ctx->as_string, ch);
4026 command->cmd_type = CMD_FUNCDEF;
4031 #if 0 /* Prevented by caller */
4032 if (command->argv /* word [word]{... */
4033 || dest->length /* word{... */
4034 || dest->has_quoted_part /* ""{... */
4037 debug_printf_parse("parse_group return 1: "
4038 "syntax error, groups and arglists don't mix\n");
4043 #if ENABLE_HUSH_FUNCTIONS
4049 command->cmd_type = CMD_SUBSHELL;
4051 /* bash does not allow "{echo...", requires whitespace */
4053 if (ch != ' ' && ch != '\t' && ch != '\n'
4054 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4056 syntax_error_unexpected_ch(ch);
4060 ch = i_getch(input);
4061 nommu_addchr(&ctx->as_string, ch);
4067 # define as_string NULL
4069 char *as_string = NULL;
4071 pipe_list = parse_stream(&as_string, input, endch);
4074 o_addstr(&ctx->as_string, as_string);
4076 /* empty ()/{} or parse error? */
4077 if (!pipe_list || pipe_list == ERR_PTR) {
4078 /* parse_stream already emitted error msg */
4081 debug_printf_parse("parse_group return 1: "
4082 "parse_stream returned %p\n", pipe_list);
4085 command->group = pipe_list;
4087 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4088 command->group_as_string = as_string;
4089 debug_printf_parse("end of group, remembering as:'%s'\n",
4090 command->group_as_string);
4094 debug_printf_parse("parse_group return 0\n");
4096 /* command remains "open", available for possible redirects */
4099 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4104 ch = i_getch(input);
4107 ch2 = i_peek(input);
4110 /* backslash+newline, skip it */
4115 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4123 ch2 = i_peek2(input);
4126 /* backslash+newline, skip it */
4132 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4133 /* Subroutines for copying $(...) and `...` things */
4134 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4136 static int add_till_single_quote(o_string *dest, struct in_str *input)
4139 int ch = i_getch(input);
4141 syntax_error_unterm_ch('\'');
4149 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4150 static int add_till_double_quote(o_string *dest, struct in_str *input)
4153 int ch = i_getch(input);
4155 syntax_error_unterm_ch('"');
4160 if (ch == '\\') { /* \x. Copy both chars. */
4162 ch = i_getch(input);
4166 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4171 //if (ch == '$') ...
4174 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4176 * "Within the backquoted style of command substitution, backslash
4177 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4178 * The search for the matching backquote shall be satisfied by the first
4179 * backquote found without a preceding backslash; during this search,
4180 * if a non-escaped backquote is encountered within a shell comment,
4181 * a here-document, an embedded command substitution of the $(command)
4182 * form, or a quoted string, undefined results occur. A single-quoted
4183 * or double-quoted string that begins, but does not end, within the
4184 * "`...`" sequence produces undefined results."
4186 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4188 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4191 int ch = i_getch(input);
4195 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4196 ch = i_getch(input);
4200 && (!in_dquote || ch != '"')
4202 o_addchr(dest, '\\');
4206 syntax_error_unterm_ch('`');
4212 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4213 * quoting and nested ()s.
4214 * "With the $(command) style of command substitution, all characters
4215 * following the open parenthesis to the matching closing parenthesis
4216 * constitute the command. Any valid shell script can be used for command,
4217 * except a script consisting solely of redirections which produces
4218 * unspecified results."
4220 * echo $(echo '(TEST)' BEST) (TEST) BEST
4221 * echo $(echo 'TEST)' BEST) TEST) BEST
4222 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4224 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4225 * can contain arbitrary constructs, just like $(cmd).
4226 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4227 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4229 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4230 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4233 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4234 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4235 char end_char2 = end_ch >> 8;
4237 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4240 ch = i_getch(input);
4242 syntax_error_unterm_ch(end_ch);
4246 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4252 /* we look for closing )) of $((EXPR)) */
4253 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4254 i_getch(input); /* eat second ')' */
4259 if (ch == '(' || ch == '{') {
4260 ch = (ch == '(' ? ')' : '}');
4261 if (!add_till_closing_bracket(dest, input, ch))
4267 if (!add_till_single_quote(dest, input))
4273 if (!add_till_double_quote(dest, input))
4279 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4285 /* \x. Copy verbatim. Important for \(, \) */
4286 ch = i_getch(input);
4288 syntax_error_unterm_ch(')');
4293 /* "backslash+newline", ignore both */
4294 o_delchr(dest); /* undo insertion of '\' */
4304 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4306 /* Return code: 0 for OK, 1 for syntax error */
4308 #define parse_dollar(as_string, dest, input, quote_mask) \
4309 parse_dollar(dest, input, quote_mask)
4310 #define as_string NULL
4312 static int parse_dollar(o_string *as_string,
4314 struct in_str *input, unsigned char quote_mask)
4316 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4318 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4320 ch = i_getch(input);
4321 nommu_addchr(as_string, ch);
4323 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4325 debug_printf_parse(": '%c'\n", ch);
4326 o_addchr(dest, ch | quote_mask);
4328 ch = i_peek_and_eat_bkslash_nl(input);
4329 if (!isalnum(ch) && ch != '_') {
4330 /* End of variable name reached */
4333 ch = i_getch(input);
4334 nommu_addchr(as_string, ch);
4336 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4337 } else if (isdigit(ch)) {
4339 ch = i_getch(input);
4340 nommu_addchr(as_string, ch);
4341 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4342 debug_printf_parse(": '%c'\n", ch);
4343 o_addchr(dest, ch | quote_mask);
4344 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4345 } else switch (ch) {
4347 case '!': /* last bg pid */
4348 case '?': /* last exit code */
4349 case '#': /* number of args */
4350 case '*': /* args */
4351 case '@': /* args */
4352 goto make_one_char_var;
4354 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4356 ch = i_getch(input); /* eat '{' */
4357 nommu_addchr(as_string, ch);
4359 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4360 /* It should be ${?}, or ${#var},
4361 * or even ${?+subst} - operator acting on a special variable,
4362 * or the beginning of variable name.
4365 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4368 syntax_error_unterm_str("${name}");
4369 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4372 nommu_addchr(as_string, ch);
4375 /* It's possible to just call add_till_closing_bracket() at this point.
4376 * However, this regresses some of our testsuite cases
4377 * which check invalid constructs like ${%}.
4378 * Oh well... let's check that the var name part is fine... */
4384 debug_printf_parse(": '%c'\n", ch);
4386 ch = i_getch(input);
4387 nommu_addchr(as_string, ch);
4391 if (!isalnum(ch) && ch != '_') {
4393 unsigned char last_ch;
4394 /* handle parameter expansions
4395 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4397 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4398 goto bad_dollar_syntax;
4400 /* Eat everything until closing '}' (or ':') */
4404 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4406 /* It's ${var:N[:M]} thing */
4407 end_ch = '}' * 0x100 + ':';
4409 if (BASH_PATTERN_SUBST
4412 /* It's ${var/[/]pattern[/repl]} thing */
4413 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4415 nommu_addchr(as_string, '/');
4418 end_ch = '}' * 0x100 + '/';
4424 #if ENABLE_HUSH_DOLLAR_OPS
4425 last_ch = add_till_closing_bracket(dest, input, end_ch);
4426 if (last_ch == 0) /* error? */
4429 #error Simple code to only allow ${var} is not implemented
4432 o_addstr(as_string, dest->data + pos);
4433 o_addchr(as_string, last_ch);
4436 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4437 && (end_ch & 0xff00)
4439 /* close the first block: */
4440 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4441 /* while parsing N from ${var:N[:M]}
4442 * or pattern from ${var/[/]pattern[/repl]} */
4443 if ((end_ch & 0xff) == last_ch) {
4444 /* got ':' or '/'- parse the rest */
4449 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4450 /* it's ${var:N} - emulate :999999999 */
4451 o_addstr(dest, "999999999");
4452 } /* else: it's ${var/[/]pattern} */
4457 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4460 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4464 ch = i_getch(input);
4465 nommu_addchr(as_string, ch);
4466 # if ENABLE_FEATURE_SH_MATH
4467 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4468 ch = i_getch(input);
4469 nommu_addchr(as_string, ch);
4470 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4471 o_addchr(dest, /*quote_mask |*/ '+');
4474 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4475 return 0; /* error */
4477 o_addstr(as_string, dest->data + pos);
4478 o_addchr(as_string, ')');
4479 o_addchr(as_string, ')');
4481 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4485 # if ENABLE_HUSH_TICK
4486 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4487 o_addchr(dest, quote_mask | '`');
4490 if (!add_till_closing_bracket(dest, input, ')'))
4491 return 0; /* error */
4493 o_addstr(as_string, dest->data + pos);
4494 o_addchr(as_string, ')');
4496 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4502 ch = i_getch(input);
4503 nommu_addchr(as_string, ch);
4504 ch = i_peek_and_eat_bkslash_nl(input);
4505 if (isalnum(ch)) { /* it's $_name or $_123 */
4510 /* TODO: $_ and $-: */
4511 /* $_ Shell or shell script name; or last argument of last command
4512 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4513 * but in command's env, set to full pathname used to invoke it */
4514 /* $- Option flags set by set builtin or shell options (-i etc) */
4516 o_addQchr(dest, '$');
4518 debug_printf_parse("parse_dollar return 1 (ok)\n");
4524 # if BASH_PATTERN_SUBST
4525 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4526 encode_string(dest, input, dquote_end, process_bkslash)
4528 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4529 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4530 encode_string(dest, input, dquote_end)
4532 #define as_string NULL
4536 # if BASH_PATTERN_SUBST
4537 /* all parameters are needed, no macro tricks */
4539 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4540 encode_string(as_string, dest, input, dquote_end)
4543 static int encode_string(o_string *as_string,
4545 struct in_str *input,
4547 int process_bkslash)
4549 #if !BASH_PATTERN_SUBST
4550 const int process_bkslash = 1;
4556 ch = i_getch(input);
4558 nommu_addchr(as_string, ch);
4559 if (ch == dquote_end) { /* may be only '"' or EOF */
4560 debug_printf_parse("encode_string return 1 (ok)\n");
4563 /* note: can't move it above ch == dquote_end check! */
4565 syntax_error_unterm_ch('"');
4566 return 0; /* error */
4570 next = i_peek(input);
4572 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4573 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4574 if (process_bkslash && ch == '\\') {
4576 syntax_error("\\<eof>");
4580 * "The backslash retains its special meaning [in "..."]
4581 * only when followed by one of the following characters:
4582 * $, `, ", \, or <newline>. A double quote may be quoted
4583 * within double quotes by preceding it with a backslash."
4584 * NB: in (unquoted) heredoc, above does not apply to ",
4585 * therefore we check for it by "next == dquote_end" cond.
4587 if (next == dquote_end || strchr("$`\\\n", next)) {
4588 ch = i_getch(input); /* eat next */
4590 goto again; /* skip \<newline> */
4591 } /* else: ch remains == '\\', and we double it below: */
4592 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4593 nommu_addchr(as_string, ch);
4597 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4598 debug_printf_parse("encode_string return 0: "
4599 "parse_dollar returned 0 (error)\n");
4604 #if ENABLE_HUSH_TICK
4606 //unsigned pos = dest->length;
4607 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4608 o_addchr(dest, 0x80 | '`');
4609 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4610 return 0; /* error */
4611 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4612 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4616 o_addQchr(dest, ch);
4622 * Scan input until EOF or end_trigger char.
4623 * Return a list of pipes to execute, or NULL on EOF
4624 * or if end_trigger character is met.
4625 * On syntax error, exit if shell is not interactive,
4626 * reset parsing machinery and start parsing anew,
4627 * or return ERR_PTR.
4629 static struct pipe *parse_stream(char **pstring,
4630 struct in_str *input,
4633 struct parse_context ctx;
4634 o_string dest = NULL_O_STRING;
4637 /* Single-quote triggers a bypass of the main loop until its mate is
4638 * found. When recursing, quote state is passed in via dest->o_expflags.
4640 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4641 end_trigger ? end_trigger : 'X');
4644 /* If very first arg is "" or '', dest.data may end up NULL.
4645 * Preventing this: */
4646 o_addchr(&dest, '\0');
4649 /* We used to separate words on $IFS here. This was wrong.
4650 * $IFS is used only for word splitting when $var is expanded,
4651 * here we should use blank chars as separators, not $IFS
4654 if (MAYBE_ASSIGNMENT != 0)
4655 dest.o_assignment = MAYBE_ASSIGNMENT;
4656 initialize_context(&ctx);
4659 const char *is_blank;
4660 const char *is_special;
4664 redir_type redir_style;
4666 ch = i_getch(input);
4667 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4668 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4673 syntax_error_unterm_str("here document");
4676 if (end_trigger == ')') {
4677 syntax_error_unterm_ch('(');
4680 if (end_trigger == '}') {
4681 syntax_error_unterm_ch('{');
4685 if (done_word(&dest, &ctx)) {
4689 done_pipe(&ctx, PIPE_SEQ);
4691 /* If we got nothing... */
4692 /* (this makes bare "&" cmd a no-op.
4693 * bash says: "syntax error near unexpected token '&'") */
4694 if (pi->num_cmds == 0
4695 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4701 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4703 *pstring = ctx.as_string.data;
4705 o_free_unsafe(&ctx.as_string);
4708 debug_printf_parse("parse_stream return %p\n", pi);
4711 nommu_addchr(&ctx.as_string, ch);
4715 next = i_peek(input);
4717 is_special = "{}<>;&|()#'" /* special outside of "str" */
4718 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4719 /* Are { and } special here? */
4720 if (ctx.command->argv /* word [word]{... - non-special */
4721 || dest.length /* word{... - non-special */
4722 || dest.has_quoted_part /* ""{... - non-special */
4723 || (next != ';' /* }; - special */
4724 && next != ')' /* }) - special */
4725 && next != '(' /* {( - special */
4726 && next != '&' /* }& and }&& ... - special */
4727 && next != '|' /* }|| ... - special */
4728 && !strchr(defifs, next) /* {word - non-special */
4731 /* They are not special, skip "{}" */
4734 is_special = strchr(is_special, ch);
4735 is_blank = strchr(defifs, ch);
4737 if (!is_special && !is_blank) { /* ordinary char */
4739 o_addQchr(&dest, ch);
4740 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4741 || dest.o_assignment == WORD_IS_KEYWORD)
4743 && is_well_formed_var_name(dest.data, '=')
4745 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4746 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4752 if (done_word(&dest, &ctx)) {
4756 /* Is this a case when newline is simply ignored?
4758 * "cmd | <newline> cmd ..."
4759 * "case ... in <newline> word) ..."
4761 if (IS_NULL_CMD(ctx.command)
4762 && dest.length == 0 && !dest.has_quoted_part
4764 /* This newline can be ignored. But...
4765 * Without check #1, interactive shell
4766 * ignores even bare <newline>,
4767 * and shows the continuation prompt:
4768 * ps1_prompt$ <enter>
4769 * ps2> _ <=== wrong, should be ps1
4770 * Without check #2, "cmd & <newline>"
4771 * is similarly mistreated.
4772 * (BTW, this makes "cmd & cmd"
4773 * and "cmd && cmd" non-orthogonal.
4774 * Really, ask yourself, why
4775 * "cmd && <newline>" doesn't start
4776 * cmd but waits for more input?
4779 struct pipe *pi = ctx.list_head;
4780 if (pi->num_cmds != 0 /* check #1 */
4781 && pi->followup != PIPE_BG /* check #2 */
4786 /* Treat newline as a command separator. */
4787 done_pipe(&ctx, PIPE_SEQ);
4788 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4790 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4795 dest.o_assignment = MAYBE_ASSIGNMENT;
4796 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4798 /* note: if (is_blank) continue;
4799 * will still trigger for us */
4803 /* "cmd}" or "cmd }..." without semicolon or &:
4804 * } is an ordinary char in this case, even inside { cmd; }
4805 * Pathological example: { ""}; } should exec "}" cmd
4808 if (dest.length != 0 /* word} */
4809 || dest.has_quoted_part /* ""} */
4813 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4814 /* Generally, there should be semicolon: "cmd; }"
4815 * However, bash allows to omit it if "cmd" is
4816 * a group. Examples:
4819 * { echo 0 >&2 | { echo 1; } }
4820 * { while false; do :; done }
4821 * { case a in b) ;; esac }
4823 if (ctx.command->group)
4827 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4828 /* Can't be an end of {cmd}, skip the check */
4829 goto skip_end_trigger;
4830 /* else: } does terminate a group */
4833 if (end_trigger && end_trigger == ch
4834 && (ch != ';' || heredoc_cnt == 0)
4835 #if ENABLE_HUSH_CASE
4837 || ctx.ctx_res_w != RES_MATCH
4838 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4843 /* This is technically valid:
4844 * { cat <<HERE; }; echo Ok
4848 * but we don't support this.
4849 * We require heredoc to be in enclosing {}/(),
4852 syntax_error_unterm_str("here document");
4855 if (done_word(&dest, &ctx)) {
4858 done_pipe(&ctx, PIPE_SEQ);
4859 dest.o_assignment = MAYBE_ASSIGNMENT;
4860 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4861 /* Do we sit outside of any if's, loops or case's? */
4863 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4867 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4869 *pstring = ctx.as_string.data;
4871 o_free_unsafe(&ctx.as_string);
4874 debug_printf_parse("parse_stream return %p: "
4875 "end_trigger char found\n",
4877 return ctx.list_head;
4884 /* Catch <, > before deciding whether this word is
4885 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4888 redir_fd = redirect_opt_num(&dest);
4889 if (done_word(&dest, &ctx)) {
4892 redir_style = REDIRECT_OVERWRITE;
4894 redir_style = REDIRECT_APPEND;
4895 ch = i_getch(input);
4896 nommu_addchr(&ctx.as_string, ch);
4899 else if (next == '(') {
4900 syntax_error(">(process) not supported");
4904 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4906 continue; /* back to top of while (1) */
4908 redir_fd = redirect_opt_num(&dest);
4909 if (done_word(&dest, &ctx)) {
4912 redir_style = REDIRECT_INPUT;
4914 redir_style = REDIRECT_HEREDOC;
4916 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4917 ch = i_getch(input);
4918 nommu_addchr(&ctx.as_string, ch);
4919 } else if (next == '>') {
4920 redir_style = REDIRECT_IO;
4921 ch = i_getch(input);
4922 nommu_addchr(&ctx.as_string, ch);
4925 else if (next == '(') {
4926 syntax_error("<(process) not supported");
4930 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4932 continue; /* back to top of while (1) */
4934 if (dest.length == 0 && !dest.has_quoted_part) {
4935 /* skip "#comment" */
4938 if (ch == EOF || ch == '\n')
4941 /* note: we do not add it to &ctx.as_string */
4943 nommu_addchr(&ctx.as_string, '\n');
4944 continue; /* back to top of while (1) */
4949 /* It's "\<newline>" */
4951 /* Remove trailing '\' from ctx.as_string */
4952 ctx.as_string.data[--ctx.as_string.length] = '\0';
4954 ch = i_getch(input); /* eat it */
4955 continue; /* back to top of while (1) */
4960 if (dest.o_assignment == MAYBE_ASSIGNMENT
4961 /* check that we are not in word in "a=1 2>word b=1": */
4962 && !ctx.pending_redirect
4964 /* ch is a special char and thus this word
4965 * cannot be an assignment */
4966 dest.o_assignment = NOT_ASSIGNMENT;
4967 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4970 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4973 case '#': /* non-comment #: "echo a#b" etc */
4974 o_addQchr(&dest, ch);
4978 syntax_error("\\<eof>");
4981 ch = i_getch(input);
4982 /* note: ch != '\n' (that case does not reach this place) */
4983 o_addchr(&dest, '\\');
4984 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4985 o_addchr(&dest, ch);
4986 nommu_addchr(&ctx.as_string, ch);
4987 /* Example: echo Hello \2>file
4988 * we need to know that word 2 is quoted */
4989 dest.has_quoted_part = 1;
4992 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4993 debug_printf_parse("parse_stream parse error: "
4994 "parse_dollar returned 0 (error)\n");
4999 dest.has_quoted_part = 1;
5000 if (next == '\'' && !ctx.pending_redirect) {
5001 insert_empty_quoted_str_marker:
5002 nommu_addchr(&ctx.as_string, next);
5003 i_getch(input); /* eat second ' */
5004 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5005 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5008 ch = i_getch(input);
5010 syntax_error_unterm_ch('\'');
5013 nommu_addchr(&ctx.as_string, ch);
5016 o_addqchr(&dest, ch);
5021 dest.has_quoted_part = 1;
5022 if (next == '"' && !ctx.pending_redirect)
5023 goto insert_empty_quoted_str_marker;
5024 if (dest.o_assignment == NOT_ASSIGNMENT)
5025 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5026 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5028 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5030 #if ENABLE_HUSH_TICK
5032 USE_FOR_NOMMU(unsigned pos;)
5034 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5035 o_addchr(&dest, '`');
5036 USE_FOR_NOMMU(pos = dest.length;)
5037 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5040 o_addstr(&ctx.as_string, dest.data + pos);
5041 o_addchr(&ctx.as_string, '`');
5043 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5044 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5049 #if ENABLE_HUSH_CASE
5052 if (done_word(&dest, &ctx)) {
5055 done_pipe(&ctx, PIPE_SEQ);
5056 #if ENABLE_HUSH_CASE
5057 /* Eat multiple semicolons, detect
5058 * whether it means something special */
5063 ch = i_getch(input);
5064 nommu_addchr(&ctx.as_string, ch);
5065 if (ctx.ctx_res_w == RES_CASE_BODY) {
5066 ctx.ctx_dsemicolon = 1;
5067 ctx.ctx_res_w = RES_MATCH;
5073 /* We just finished a cmd. New one may start
5074 * with an assignment */
5075 dest.o_assignment = MAYBE_ASSIGNMENT;
5076 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5079 if (done_word(&dest, &ctx)) {
5083 ch = i_getch(input);
5084 nommu_addchr(&ctx.as_string, ch);
5085 done_pipe(&ctx, PIPE_AND);
5087 done_pipe(&ctx, PIPE_BG);
5091 if (done_word(&dest, &ctx)) {
5094 #if ENABLE_HUSH_CASE
5095 if (ctx.ctx_res_w == RES_MATCH)
5096 break; /* we are in case's "word | word)" */
5098 if (next == '|') { /* || */
5099 ch = i_getch(input);
5100 nommu_addchr(&ctx.as_string, ch);
5101 done_pipe(&ctx, PIPE_OR);
5103 /* we could pick up a file descriptor choice here
5104 * with redirect_opt_num(), but bash doesn't do it.
5105 * "echo foo 2| cat" yields "foo 2". */
5110 #if ENABLE_HUSH_CASE
5111 /* "case... in [(]word)..." - skip '(' */
5112 if (ctx.ctx_res_w == RES_MATCH
5113 && ctx.command->argv == NULL /* not (word|(... */
5114 && dest.length == 0 /* not word(... */
5115 && dest.has_quoted_part == 0 /* not ""(... */
5121 if (parse_group(&dest, &ctx, input, ch) != 0) {
5126 #if ENABLE_HUSH_CASE
5127 if (ctx.ctx_res_w == RES_MATCH)
5131 /* proper use of this character is caught by end_trigger:
5132 * if we see {, we call parse_group(..., end_trigger='}')
5133 * and it will match } earlier (not here). */
5134 syntax_error_unexpected_ch(ch);
5135 G.last_exitcode = 2;
5139 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5144 G.last_exitcode = 1;
5147 struct parse_context *pctx;
5148 IF_HAS_KEYWORDS(struct parse_context *p2;)
5150 /* Clean up allocated tree.
5151 * Sample for finding leaks on syntax error recovery path.
5152 * Run it from interactive shell, watch pmap `pidof hush`.
5153 * while if false; then false; fi; do break; fi
5154 * Samples to catch leaks at execution:
5155 * while if (true | { true;}); then echo ok; fi; do break; done
5156 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5160 /* Update pipe/command counts,
5161 * otherwise freeing may miss some */
5162 done_pipe(pctx, PIPE_SEQ);
5163 debug_printf_clean("freeing list %p from ctx %p\n",
5164 pctx->list_head, pctx);
5165 debug_print_tree(pctx->list_head, 0);
5166 free_pipe_list(pctx->list_head);
5167 debug_printf_clean("freed list %p\n", pctx->list_head);
5169 o_free_unsafe(&pctx->as_string);
5171 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5175 IF_HAS_KEYWORDS(pctx = p2;)
5176 } while (HAS_KEYWORDS && pctx);
5189 /*** Execution routines ***/
5191 /* Expansion can recurse, need forward decls: */
5192 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5193 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5194 #define expand_string_to_string(str, do_unbackslash) \
5195 expand_string_to_string(str)
5197 static char *expand_string_to_string(const char *str, int do_unbackslash);
5198 #if ENABLE_HUSH_TICK
5199 static int process_command_subs(o_string *dest, const char *s);
5202 /* expand_strvec_to_strvec() takes a list of strings, expands
5203 * all variable references within and returns a pointer to
5204 * a list of expanded strings, possibly with larger number
5205 * of strings. (Think VAR="a b"; echo $VAR).
5206 * This new list is allocated as a single malloc block.
5207 * NULL-terminated list of char* pointers is at the beginning of it,
5208 * followed by strings themselves.
5209 * Caller can deallocate entire list by single free(list). */
5211 /* A horde of its helpers come first: */
5213 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5215 while (--len >= 0) {
5218 #if ENABLE_HUSH_BRACE_EXPANSION
5219 if (c == '{' || c == '}') {
5220 /* { -> \{, } -> \} */
5222 /* And now we want to add { or } and continue:
5225 * luckily, just falling through achieves this.
5231 /* \z -> \\\z; \<eol> -> \\<eol> */
5236 o_addchr(o, *str++);
5242 /* Store given string, finalizing the word and starting new one whenever
5243 * we encounter IFS char(s). This is used for expanding variable values.
5244 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5245 * Return in *ended_with_ifs:
5246 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5248 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5250 int last_is_ifs = 0;
5255 if (!*str) /* EOL - do not finalize word */
5257 word_len = strcspn(str, G.ifs);
5259 /* We have WORD_LEN leading non-IFS chars */
5260 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5261 o_addblock(output, str, word_len);
5263 /* Protect backslashes against globbing up :)
5264 * Example: "v='\*'; echo b$v" prints "b\*"
5265 * (and does not try to glob on "*")
5267 o_addblock_duplicate_backslash(output, str, word_len);
5268 /*/ Why can't we do it easier? */
5269 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5270 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5274 if (!*str) /* EOL - do not finalize word */
5278 /* We know str here points to at least one IFS char */
5280 str += strspn(str, G.ifs); /* skip IFS chars */
5281 if (!*str) /* EOL - do not finalize word */
5284 /* Start new word... but not always! */
5285 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5286 if (output->has_quoted_part
5287 /* Case "v=' a'; echo $v":
5288 * here nothing precedes the space in $v expansion,
5289 * therefore we should not finish the word
5290 * (IOW: if there *is* word to finalize, only then do it):
5292 || (n > 0 && output->data[output->length - 1])
5294 o_addchr(output, '\0');
5295 debug_print_list("expand_on_ifs", output, n);
5296 n = o_save_ptr(output, n);
5301 *ended_with_ifs = last_is_ifs;
5302 debug_print_list("expand_on_ifs[1]", output, n);
5306 /* Helper to expand $((...)) and heredoc body. These act as if
5307 * they are in double quotes, with the exception that they are not :).
5308 * Just the rules are similar: "expand only $var and `cmd`"
5310 * Returns malloced string.
5311 * As an optimization, we return NULL if expansion is not needed.
5313 #if !BASH_PATTERN_SUBST
5314 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5315 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5316 encode_then_expand_string(str)
5318 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5320 #if !BASH_PATTERN_SUBST
5321 const int do_unbackslash = 1;
5324 struct in_str input;
5325 o_string dest = NULL_O_STRING;
5327 if (!strchr(str, '$')
5328 && !strchr(str, '\\')
5329 #if ENABLE_HUSH_TICK
5330 && !strchr(str, '`')
5336 /* We need to expand. Example:
5337 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5339 setup_string_in_str(&input, str);
5340 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5341 //TODO: error check (encode_string returns 0 on error)?
5342 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5343 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5344 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5345 o_free_unsafe(&dest);
5349 #if ENABLE_FEATURE_SH_MATH
5350 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5352 arith_state_t math_state;
5356 math_state.lookupvar = get_local_var_value;
5357 math_state.setvar = set_local_var_from_halves;
5358 //math_state.endofname = endofname;
5359 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5360 res = arith(&math_state, exp_str ? exp_str : arg);
5363 *errmsg_p = math_state.errmsg;
5364 if (math_state.errmsg)
5365 die_if_script(math_state.errmsg);
5370 #if BASH_PATTERN_SUBST
5371 /* ${var/[/]pattern[/repl]} helpers */
5372 static char *strstr_pattern(char *val, const char *pattern, int *size)
5375 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5376 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5383 /* Optimization: if "*pat" did not match the start of "string",
5384 * we know that "tring", "ring" etc will not match too:
5386 if (pattern[0] == '*')
5391 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5393 char *result = NULL;
5394 unsigned res_len = 0;
5395 unsigned repl_len = strlen(repl);
5399 char *s = strstr_pattern(val, pattern, &size);
5403 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5404 memcpy(result + res_len, val, s - val);
5406 strcpy(result + res_len, repl);
5407 res_len += repl_len;
5408 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5414 if (val[0] && result) {
5415 result = xrealloc(result, res_len + strlen(val) + 1);
5416 strcpy(result + res_len, val);
5417 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5419 debug_printf_varexp("result:'%s'\n", result);
5422 #endif /* BASH_PATTERN_SUBST */
5425 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5427 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5429 const char *val = NULL;
5430 char *to_be_freed = NULL;
5435 char exp_save = exp_save; /* for compiler */
5436 char *exp_saveptr; /* points to expansion operator */
5437 char *exp_word = exp_word; /* for compiler */
5440 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5442 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5444 first_char = arg[0] = arg0 & 0x7f;
5447 if (first_char == '#' /* ${#... */
5448 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5450 /* It must be length operator: ${#var} */
5454 /* Maybe handle parameter expansion */
5455 if (exp_saveptr /* if 2nd char is one of expansion operators */
5456 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5458 /* ${?:0}, ${#[:]%0} etc */
5459 exp_saveptr = var + 1;
5461 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5462 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5464 exp_op = exp_save = *exp_saveptr;
5466 exp_word = exp_saveptr + 1;
5467 if (exp_op == ':') {
5468 exp_op = *exp_word++;
5469 //TODO: try ${var:} and ${var:bogus} in non-bash config
5471 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5473 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5478 *exp_saveptr = '\0';
5479 } /* else: it's not an expansion op, but bare ${var} */
5482 /* Look up the variable in question */
5483 if (isdigit(var[0])) {
5484 /* parse_dollar should have vetted var for us */
5485 int n = xatoi_positive(var);
5486 if (n < G.global_argc)
5487 val = G.global_argv[n];
5488 /* else val remains NULL: $N with too big N */
5492 val = utoa(G.root_pid);
5494 case '!': /* bg pid */
5495 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5497 case '?': /* exitcode */
5498 val = utoa(G.last_exitcode);
5500 case '#': /* argc */
5501 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5504 val = get_local_var_value(var);
5508 /* Handle any expansions */
5509 if (exp_op == 'L') {
5510 reinit_unicode_for_hush();
5511 debug_printf_expand("expand: length(%s)=", val);
5512 val = utoa(val ? unicode_strlen(val) : 0);
5513 debug_printf_expand("%s\n", val);
5514 } else if (exp_op) {
5515 if (exp_op == '%' || exp_op == '#') {
5516 /* Standard-mandated substring removal ops:
5517 * ${parameter%word} - remove smallest suffix pattern
5518 * ${parameter%%word} - remove largest suffix pattern
5519 * ${parameter#word} - remove smallest prefix pattern
5520 * ${parameter##word} - remove largest prefix pattern
5522 * Word is expanded to produce a glob pattern.
5523 * Then var's value is matched to it and matching part removed.
5525 if (val && val[0]) {
5529 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5530 if (exp_op == *exp_word) /* ## or %% */
5532 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5534 exp_word = exp_exp_word;
5535 /* HACK ALERT. We depend here on the fact that
5536 * G.global_argv and results of utoa and get_local_var_value
5537 * are actually in writable memory:
5538 * scan_and_match momentarily stores NULs there. */
5540 loc = scan_and_match(t, exp_word, scan_flags);
5541 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5542 // exp_op, t, exp_word, loc);
5544 if (loc) { /* match was found */
5545 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5546 val = loc; /* take right part */
5548 val = to_be_freed = xstrndup(val, loc - val); /* left */
5552 #if BASH_PATTERN_SUBST
5553 else if (exp_op == '/' || exp_op == '\\') {
5554 /* It's ${var/[/]pattern[/repl]} thing.
5555 * Note that in encoded form it has TWO parts:
5556 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5557 * and if // is used, it is encoded as \:
5558 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5560 /* Empty variable always gives nothing: */
5561 // "v=''; echo ${v/*/w}" prints "", not "w"
5562 if (val && val[0]) {
5563 /* pattern uses non-standard expansion.
5564 * repl should be unbackslashed and globbed
5565 * by the usual expansion rules:
5567 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5568 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5569 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5570 * v='a bz'; echo ${v/a*z/\z} prints "z"
5571 * (note that a*z _pattern_ is never globbed!)
5573 char *pattern, *repl, *t;
5574 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5576 pattern = xstrdup(exp_word);
5577 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5578 *p++ = SPECIAL_VAR_SYMBOL;
5580 p = strchr(p, SPECIAL_VAR_SYMBOL);
5582 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5583 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5584 /* HACK ALERT. We depend here on the fact that
5585 * G.global_argv and results of utoa and get_local_var_value
5586 * are actually in writable memory:
5587 * replace_pattern momentarily stores NULs there. */
5589 to_be_freed = replace_pattern(t,
5591 (repl ? repl : exp_word),
5593 if (to_be_freed) /* at least one replace happened */
5599 #endif /* BASH_PATTERN_SUBST */
5600 else if (exp_op == ':') {
5601 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5602 /* It's ${var:N[:M]} bashism.
5603 * Note that in encoded form it has TWO parts:
5604 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5609 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5612 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5613 *p++ = SPECIAL_VAR_SYMBOL;
5615 p = strchr(p, SPECIAL_VAR_SYMBOL);
5617 len = expand_and_evaluate_arith(exp_word, &errmsg);
5620 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5621 if (len >= 0) { /* bash compat: len < 0 is illegal */
5623 /* negative beg counts from the end */
5624 beg = (arith_t)strlen(val) + beg;
5625 if (beg < 0) /* ${v: -999999} is "" */
5628 debug_printf_varexp("from val:'%s'\n", val);
5629 if (len == 0 || !val || beg >= strlen(val)) {
5633 /* Paranoia. What if user entered 9999999999999
5634 * which fits in arith_t but not int? */
5637 val = to_be_freed = xstrndup(val + beg, len);
5639 debug_printf_varexp("val:'%s'\n", val);
5641 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5643 die_if_script("malformed ${%s:...}", var);
5646 } else { /* one of "-=+?" */
5647 /* Standard-mandated substitution ops:
5648 * ${var?word} - indicate error if unset
5649 * If var is unset, word (or a message indicating it is unset
5650 * if word is null) is written to standard error
5651 * and the shell exits with a non-zero exit status.
5652 * Otherwise, the value of var is substituted.
5653 * ${var-word} - use default value
5654 * If var is unset, word is substituted.
5655 * ${var=word} - assign and use default value
5656 * If var is unset, word is assigned to var.
5657 * In all cases, final value of var is substituted.
5658 * ${var+word} - use alternative value
5659 * If var is unset, null is substituted.
5660 * Otherwise, word is substituted.
5662 * Word is subjected to tilde expansion, parameter expansion,
5663 * command substitution, and arithmetic expansion.
5664 * If word is not needed, it is not expanded.
5666 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5667 * but also treat null var as if it is unset.
5669 int use_word = (!val || ((exp_save == ':') && !val[0]));
5671 use_word = !use_word;
5672 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5673 (exp_save == ':') ? "true" : "false", use_word);
5675 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5677 exp_word = to_be_freed;
5678 if (exp_op == '?') {
5679 /* mimic bash message */
5680 die_if_script("%s: %s",
5682 exp_word[0] ? exp_word : "parameter null or not set"
5684 //TODO: how interactive bash aborts expansion mid-command?
5689 if (exp_op == '=') {
5690 /* ${var=[word]} or ${var:=[word]} */
5691 if (isdigit(var[0]) || var[0] == '#') {
5692 /* mimic bash message */
5693 die_if_script("$%s: cannot assign in this way", var);
5696 char *new_var = xasprintf("%s=%s", var, val);
5697 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5701 } /* one of "-=+?" */
5703 *exp_saveptr = exp_save;
5709 *to_be_freed_pp = to_be_freed;
5713 /* Expand all variable references in given string, adding words to list[]
5714 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5715 * to be filled). This routine is extremely tricky: has to deal with
5716 * variables/parameters with whitespace, $* and $@, and constructs like
5717 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5718 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5720 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5721 * expansion of right-hand side of assignment == 1-element expand.
5723 char cant_be_null = 0; /* only bit 0x80 matters */
5724 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5727 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5728 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5729 debug_print_list("expand_vars_to_list", output, n);
5730 n = o_save_ptr(output, n);
5731 debug_print_list("expand_vars_to_list[0]", output, n);
5733 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5735 char *to_be_freed = NULL;
5736 const char *val = NULL;
5737 #if ENABLE_HUSH_TICK
5738 o_string subst_result = NULL_O_STRING;
5740 #if ENABLE_FEATURE_SH_MATH
5741 char arith_buf[sizeof(arith_t)*3 + 2];
5745 o_addchr(output, '\0');
5746 n = o_save_ptr(output, n);
5750 o_addblock(output, arg, p - arg);
5751 debug_print_list("expand_vars_to_list[1]", output, n);
5753 p = strchr(p, SPECIAL_VAR_SYMBOL);
5755 /* Fetch special var name (if it is indeed one of them)
5756 * and quote bit, force the bit on if singleword expansion -
5757 * important for not getting v=$@ expand to many words. */
5758 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5760 /* Is this variable quoted and thus expansion can't be null?
5761 * "$@" is special. Even if quoted, it can still
5762 * expand to nothing (not even an empty string),
5763 * thus it is excluded. */
5764 if ((first_ch & 0x7f) != '@')
5765 cant_be_null |= first_ch;
5767 switch (first_ch & 0x7f) {
5768 /* Highest bit in first_ch indicates that var is double-quoted */
5772 if (!G.global_argv[1])
5775 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5776 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5777 while (G.global_argv[i]) {
5778 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5779 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5780 if (G.global_argv[i++][0] && G.global_argv[i]) {
5781 /* this argv[] is not empty and not last:
5782 * put terminating NUL, start new word */
5783 o_addchr(output, '\0');
5784 debug_print_list("expand_vars_to_list[2]", output, n);
5785 n = o_save_ptr(output, n);
5786 debug_print_list("expand_vars_to_list[3]", output, n);
5790 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5791 * and in this case should treat it like '$*' - see 'else...' below */
5792 if (first_ch == ('@'|0x80) /* quoted $@ */
5793 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5796 o_addQstr(output, G.global_argv[i]);
5797 if (++i >= G.global_argc)
5799 o_addchr(output, '\0');
5800 debug_print_list("expand_vars_to_list[4]", output, n);
5801 n = o_save_ptr(output, n);
5803 } else { /* quoted $* (or v="$@" case): add as one word */
5805 o_addQstr(output, G.global_argv[i]);
5806 if (!G.global_argv[++i])
5809 o_addchr(output, G.ifs[0]);
5811 output->has_quoted_part = 1;
5815 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5816 /* "Empty variable", used to make "" etc to not disappear */
5817 output->has_quoted_part = 1;
5819 cant_be_null = 0x80;
5821 #if ENABLE_HUSH_TICK
5822 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5823 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5825 /* Can't just stuff it into output o_string,
5826 * expanded result may need to be globbed
5828 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5829 G.last_exitcode = process_command_subs(&subst_result, arg);
5830 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5831 val = subst_result.data;
5834 #if ENABLE_FEATURE_SH_MATH
5835 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5838 arg++; /* skip '+' */
5839 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5840 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5841 res = expand_and_evaluate_arith(arg, NULL);
5842 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5843 sprintf(arith_buf, ARITH_FMT, res);
5849 val = expand_one_var(&to_be_freed, arg, &p);
5850 IF_HUSH_TICK(store_val:)
5851 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5852 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5853 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5854 if (val && val[0]) {
5855 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5858 } else { /* quoted $VAR, val will be appended below */
5859 output->has_quoted_part = 1;
5860 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5861 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5864 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5866 if (val && val[0]) {
5867 o_addQstr(output, val);
5871 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5872 * Do the check to avoid writing to a const string. */
5873 if (*p != SPECIAL_VAR_SYMBOL)
5874 *p = SPECIAL_VAR_SYMBOL;
5876 #if ENABLE_HUSH_TICK
5877 o_free(&subst_result);
5880 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5884 o_addchr(output, '\0');
5885 n = o_save_ptr(output, n);
5887 debug_print_list("expand_vars_to_list[a]", output, n);
5888 /* this part is literal, and it was already pre-quoted
5889 * if needed (much earlier), do not use o_addQstr here! */
5890 o_addstr_with_NUL(output, arg);
5891 debug_print_list("expand_vars_to_list[b]", output, n);
5892 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5893 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5896 /* allow to reuse list[n] later without re-growth */
5897 output->has_empty_slot = 1;
5899 o_addchr(output, '\0');
5905 static char **expand_variables(char **argv, unsigned expflags)
5909 o_string output = NULL_O_STRING;
5911 output.o_expflags = expflags;
5915 n = expand_vars_to_list(&output, n, *argv);
5918 debug_print_list("expand_variables", &output, n);
5920 /* output.data (malloced in one block) gets returned in "list" */
5921 list = o_finalize_list(&output, n);
5922 debug_print_strings("expand_variables[1]", list);
5926 static char **expand_strvec_to_strvec(char **argv)
5928 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5932 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5934 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5938 /* Used for expansion of right hand of assignments,
5939 * $((...)), heredocs, variable espansion parts.
5941 * NB: should NOT do globbing!
5942 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5944 static char *expand_string_to_string(const char *str, int do_unbackslash)
5946 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5947 const int do_unbackslash = 1;
5949 char *argv[2], **list;
5951 debug_printf_expand("string_to_string<='%s'\n", str);
5952 /* This is generally an optimization, but it also
5953 * handles "", which otherwise trips over !list[0] check below.
5954 * (is this ever happens that we actually get str="" here?)
5956 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5957 //TODO: Can use on strings with \ too, just unbackslash() them?
5958 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5959 return xstrdup(str);
5962 argv[0] = (char*)str;
5964 list = expand_variables(argv, do_unbackslash
5965 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5966 : EXP_FLAG_SINGLEWORD
5969 if (!list[0] || list[1])
5970 bb_error_msg_and_die("BUG in varexp2");
5971 /* actually, just move string 2*sizeof(char*) bytes back */
5972 overlapping_strcpy((char*)list, list[0]);
5974 unbackslash((char*)list);
5975 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5979 /* Used for "eval" builtin and case string */
5980 static char* expand_strvec_to_string(char **argv)
5984 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5985 /* Convert all NULs to spaces */
5990 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5991 bb_error_msg_and_die("BUG in varexp3");
5992 /* bash uses ' ' regardless of $IFS contents */
5997 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5998 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6002 static char **expand_assignments(char **argv, int count)
6007 G.expanded_assignments = p = NULL;
6008 /* Expand assignments into one string each */
6009 for (i = 0; i < count; i++) {
6010 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6012 G.expanded_assignments = NULL;
6017 static void switch_off_special_sigs(unsigned mask)
6020 while ((mask >>= 1) != 0) {
6024 #if ENABLE_HUSH_TRAP
6026 if (G_traps[sig] && !G_traps[sig][0])
6027 /* trap is '', has to remain SIG_IGN */
6030 G_traps[sig] = NULL;
6033 /* We are here only if no trap or trap was not '' */
6034 install_sighandler(sig, SIG_DFL);
6040 void re_execute_shell(char ***to_free, const char *s,
6041 char *g_argv0, char **g_argv,
6042 char **builtin_argv) NORETURN;
6044 static void reset_traps_to_defaults(void)
6046 /* This function is always called in a child shell
6047 * after fork (not vfork, NOMMU doesn't use this function).
6049 IF_HUSH_TRAP(unsigned sig;)
6052 /* Child shells are not interactive.
6053 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6054 * Testcase: (while :; do :; done) + ^Z should background.
6055 * Same goes for SIGTERM, SIGHUP, SIGINT.
6057 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6058 if (!G_traps && !mask)
6059 return; /* already no traps and no special sigs */
6061 /* Switch off special sigs */
6062 switch_off_special_sigs(mask);
6063 # if ENABLE_HUSH_JOB
6064 G_fatal_sig_mask = 0;
6066 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6067 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6068 * remain set in G.special_sig_mask */
6070 # if ENABLE_HUSH_TRAP
6074 /* Reset all sigs to default except ones with empty traps */
6075 for (sig = 0; sig < NSIG; sig++) {
6077 continue; /* no trap: nothing to do */
6078 if (!G_traps[sig][0])
6079 continue; /* empty trap: has to remain SIG_IGN */
6080 /* sig has non-empty trap, reset it: */
6082 G_traps[sig] = NULL;
6083 /* There is no signal for trap 0 (EXIT) */
6086 install_sighandler(sig, pick_sighandler(sig));
6093 static void re_execute_shell(char ***to_free, const char *s,
6094 char *g_argv0, char **g_argv,
6095 char **builtin_argv) NORETURN;
6096 static void re_execute_shell(char ***to_free, const char *s,
6097 char *g_argv0, char **g_argv,
6098 char **builtin_argv)
6100 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6101 /* delims + 2 * (number of bytes in printed hex numbers) */
6102 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6103 char *heredoc_argv[4];
6104 struct variable *cur;
6105 # if ENABLE_HUSH_FUNCTIONS
6106 struct function *funcp;
6110 unsigned long long empty_trap_mask;
6112 if (!g_argv0) { /* heredoc */
6113 argv = heredoc_argv;
6114 argv[0] = (char *) G.argv0_for_re_execing;
6115 argv[1] = (char *) "-<";
6116 argv[2] = (char *) s;
6118 pp = &argv[3]; /* used as pointer to empty environment */
6124 if (pp) while (*pp++)
6127 empty_trap_mask = 0;
6130 for (sig = 1; sig < NSIG; sig++) {
6131 if (G_traps[sig] && !G_traps[sig][0])
6132 empty_trap_mask |= 1LL << sig;
6136 sprintf(param_buf, NOMMU_HACK_FMT
6137 , (unsigned) G.root_pid
6138 , (unsigned) G.root_ppid
6139 , (unsigned) G.last_bg_pid
6140 , (unsigned) G.last_exitcode
6143 IF_HUSH_LOOPS(, G.depth_of_loop)
6145 # undef NOMMU_HACK_FMT
6146 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6147 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6150 for (cur = G.top_var; cur; cur = cur->next) {
6151 if (!cur->flg_export || cur->flg_read_only)
6154 # if ENABLE_HUSH_FUNCTIONS
6155 for (funcp = G.top_func; funcp; funcp = funcp->next)
6161 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6162 *pp++ = (char *) G.argv0_for_re_execing;
6164 for (cur = G.top_var; cur; cur = cur->next) {
6165 if (strcmp(cur->varstr, hush_version_str) == 0)
6167 if (cur->flg_read_only) {
6168 *pp++ = (char *) "-R";
6169 *pp++ = cur->varstr;
6170 } else if (!cur->flg_export) {
6171 *pp++ = (char *) "-V";
6172 *pp++ = cur->varstr;
6175 # if ENABLE_HUSH_FUNCTIONS
6176 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6177 *pp++ = (char *) "-F";
6178 *pp++ = funcp->name;
6179 *pp++ = funcp->body_as_string;
6182 /* We can pass activated traps here. Say, -Tnn:trap_string
6184 * However, POSIX says that subshells reset signals with traps
6186 * I tested bash-3.2 and it not only does that with true subshells
6187 * of the form ( list ), but with any forked children shells.
6188 * I set trap "echo W" WINCH; and then tried:
6190 * { echo 1; sleep 20; echo 2; } &
6191 * while true; do echo 1; sleep 20; echo 2; break; done &
6192 * true | { echo 1; sleep 20; echo 2; } | cat
6194 * In all these cases sending SIGWINCH to the child shell
6195 * did not run the trap. If I add trap "echo V" WINCH;
6196 * _inside_ group (just before echo 1), it works.
6198 * I conclude it means we don't need to pass active traps here.
6200 *pp++ = (char *) "-c";
6203 while (*++builtin_argv)
6204 *pp++ = *builtin_argv;
6205 *pp++ = (char *) "";
6210 /* *pp = NULL; - is already there */
6214 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6215 /* Don't propagate SIG_IGN to the child */
6216 if (SPECIAL_JOBSTOP_SIGS != 0)
6217 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6218 execve(bb_busybox_exec_path, argv, pp);
6219 /* Fallback. Useful for init=/bin/hush usage etc */
6220 if (argv[0][0] == '/')
6221 execve(argv[0], argv, pp);
6222 xfunc_error_retval = 127;
6223 bb_error_msg_and_die("can't re-execute the shell");
6225 #endif /* !BB_MMU */
6228 static int run_and_free_list(struct pipe *pi);
6230 /* Executing from string: eval, sh -c '...'
6231 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6232 * end_trigger controls how often we stop parsing
6233 * NUL: parse all, execute, return
6234 * ';': parse till ';' or newline, execute, repeat till EOF
6236 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6238 /* Why we need empty flag?
6239 * An obscure corner case "false; ``; echo $?":
6240 * empty command in `` should still set $? to 0.
6241 * But we can't just set $? to 0 at the start,
6242 * this breaks "false; echo `echo $?`" case.
6246 struct pipe *pipe_list;
6248 #if ENABLE_HUSH_INTERACTIVE
6249 if (end_trigger == ';')
6250 inp->promptmode = 0; /* PS1 */
6252 pipe_list = parse_stream(NULL, inp, end_trigger);
6253 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6254 /* If we are in "big" script
6255 * (not in `cmd` or something similar)...
6257 if (pipe_list == ERR_PTR && end_trigger == ';') {
6258 /* Discard cached input (rest of line) */
6259 int ch = inp->last_char;
6260 while (ch != EOF && ch != '\n') {
6261 //bb_error_msg("Discarded:'%c'", ch);
6266 /* This stream isn't empty */
6270 if (!pipe_list && empty)
6271 G.last_exitcode = 0;
6274 debug_print_tree(pipe_list, 0);
6275 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6276 run_and_free_list(pipe_list);
6278 if (G_flag_return_in_progress == 1)
6283 static void parse_and_run_string(const char *s)
6285 struct in_str input;
6286 setup_string_in_str(&input, s);
6287 parse_and_run_stream(&input, '\0');
6290 static void parse_and_run_file(FILE *f)
6292 struct in_str input;
6293 setup_file_in_str(&input, f);
6294 parse_and_run_stream(&input, ';');
6297 #if ENABLE_HUSH_TICK
6298 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6303 char **to_free = NULL;
6307 pid = BB_MMU ? xfork() : xvfork();
6308 if (pid == 0) { /* child */
6309 disable_restore_tty_pgrp_on_exit();
6310 /* Process substitution is not considered to be usual
6311 * 'command execution'.
6312 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6319 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6320 close(channel[0]); /* NB: close _first_, then move fd! */
6321 xmove_fd(channel[1], 1);
6322 /* Prevent it from trying to handle ctrl-z etc */
6323 IF_HUSH_JOB(G.run_list_level = 1;)
6324 # if ENABLE_HUSH_TRAP
6325 /* Awful hack for `trap` or $(trap).
6327 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6328 * contains an example where "trap" is executed in a subshell:
6330 * save_traps=$(trap)
6332 * eval "$save_traps"
6334 * Standard does not say that "trap" in subshell shall print
6335 * parent shell's traps. It only says that its output
6336 * must have suitable form, but then, in the above example
6337 * (which is not supposed to be normative), it implies that.
6339 * bash (and probably other shell) does implement it
6340 * (traps are reset to defaults, but "trap" still shows them),
6341 * but as a result, "trap" logic is hopelessly messed up:
6344 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6345 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6346 * # true | trap <--- trap is in subshell - no output (ditto)
6347 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6348 * trap -- 'echo Ho' SIGWINCH
6349 * # echo `(trap)` <--- in subshell in subshell - output
6350 * trap -- 'echo Ho' SIGWINCH
6351 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6352 * trap -- 'echo Ho' SIGWINCH
6354 * The rules when to forget and when to not forget traps
6355 * get really complex and nonsensical.
6357 * Our solution: ONLY bare $(trap) or `trap` is special.
6359 s = skip_whitespace(s);
6360 if (is_prefixed_with(s, "trap")
6361 && skip_whitespace(s + 4)[0] == '\0'
6363 static const char *const argv[] = { NULL, NULL };
6364 builtin_trap((char**)argv);
6365 fflush_all(); /* important */
6370 reset_traps_to_defaults();
6371 parse_and_run_string(s);
6372 _exit(G.last_exitcode);
6374 /* We re-execute after vfork on NOMMU. This makes this script safe:
6375 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6376 * huge=`cat BIG` # was blocking here forever
6379 re_execute_shell(&to_free,
6389 # if ENABLE_HUSH_FAST
6391 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6392 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6393 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6395 enable_restore_tty_pgrp_on_exit();
6400 return remember_FILE(xfdopen_for_read(channel[0]));
6403 /* Return code is exit status of the process that is run. */
6404 static int process_command_subs(o_string *dest, const char *s)
6407 struct in_str pipe_str;
6409 int status, ch, eol_cnt;
6411 fp = generate_stream_from_string(s, &pid);
6413 /* Now send results of command back into original context */
6414 setup_file_in_str(&pipe_str, fp);
6416 while ((ch = i_getch(&pipe_str)) != EOF) {
6422 o_addchr(dest, '\n');
6425 o_addQchr(dest, ch);
6428 debug_printf("done reading from `cmd` pipe, closing it\n");
6429 fclose_and_forget(fp);
6430 /* We need to extract exitcode. Test case
6431 * "true; echo `sleep 1; false` $?"
6433 safe_waitpid(pid, &status, 0);
6434 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6435 return WEXITSTATUS(status);
6437 #endif /* ENABLE_HUSH_TICK */
6440 static void setup_heredoc(struct redir_struct *redir)
6442 struct fd_pair pair;
6445 /* the _body_ of heredoc (misleading field name) */
6446 const char *heredoc = redir->rd_filename;
6453 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6454 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6458 len = strlen(heredoc);
6460 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6462 xmove_fd(pair.rd, redir->rd_fd);
6464 /* Try writing without forking. Newer kernels have
6465 * dynamically growing pipes. Must use non-blocking write! */
6468 written = write(pair.wr, heredoc, len);
6479 ndelay_off(pair.wr);
6481 /* Okay, pipe buffer was not big enough */
6482 /* Note: we must not create a stray child (bastard? :)
6483 * for the unsuspecting parent process. Child creates a grandchild
6484 * and exits before parent execs the process which consumes heredoc
6485 * (that exec happens after we return from this function) */
6492 disable_restore_tty_pgrp_on_exit();
6493 pid = BB_MMU ? xfork() : xvfork();
6497 close(redir->rd_fd); /* read side of the pipe */
6499 full_write(pair.wr, heredoc, len); /* may loop or block */
6502 /* Delegate blocking writes to another process */
6503 xmove_fd(pair.wr, STDOUT_FILENO);
6504 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6508 #if ENABLE_HUSH_FAST
6510 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6512 enable_restore_tty_pgrp_on_exit();
6518 wait(NULL); /* wait till child has died */
6521 /* fd: redirect wants this fd to be used (e.g. 3>file).
6522 * Move all conflicting internally used fds,
6523 * and remember them so that we can restore them later.
6525 static int save_fds_on_redirect(int fd, int squirrel[3])
6528 /* Handle redirects of fds 0,1,2 */
6530 /* If we collide with an already moved stdio fd... */
6531 if (fd == squirrel[0]) {
6532 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6535 if (fd == squirrel[1]) {
6536 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6539 if (fd == squirrel[2]) {
6540 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6543 /* If we are about to redirect stdio fd, and did not yet move it... */
6544 if (fd <= 2 && squirrel[fd] < 0) {
6545 /* We avoid taking stdio fds */
6546 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6547 if (squirrel[fd] < 0 && errno != EBADF)
6549 return 0; /* "we did not close fd" */
6553 #if ENABLE_HUSH_INTERACTIVE
6554 if (fd != 0 && fd == G.interactive_fd) {
6555 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6560 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6561 * (1) Redirect in a forked child. No need to save FILEs' fds,
6562 * we aren't going to use them anymore, ok to trash.
6563 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6564 * but how are we doing to use them?
6565 * "fileno(fd) = new_fd" can't be done.
6570 return save_FILEs_on_redirect(fd);
6573 static void restore_redirects(int squirrel[3])
6576 for (i = 0; i <= 2; i++) {
6579 /* We simply die on error */
6584 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6586 restore_redirected_FILEs();
6589 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6590 * and stderr if they are redirected. */
6591 static int setup_redirects(struct command *prog, int squirrel[])
6594 struct redir_struct *redir;
6596 for (redir = prog->redirects; redir; redir = redir->next) {
6597 if (redir->rd_type == REDIRECT_HEREDOC2) {
6598 /* "rd_fd<<HERE" case */
6599 save_fds_on_redirect(redir->rd_fd, squirrel);
6600 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6602 debug_printf_parse("set heredoc '%s'\n",
6603 redir->rd_filename);
6604 setup_heredoc(redir);
6608 if (redir->rd_dup == REDIRFD_TO_FILE) {
6609 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6611 if (redir->rd_filename == NULL) {
6614 * "cmd >" (no filename)
6615 * "cmd > <file" (2nd redirect starts too early)
6617 die_if_script("syntax error: %s", "invalid redirect");
6620 mode = redir_table[redir->rd_type].mode;
6621 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6622 openfd = open_or_warn(p, mode);
6625 /* Error message from open_or_warn can be lost
6626 * if stderr has been redirected, but bash
6627 * and ash both lose it as well
6628 * (though zsh doesn't!)
6633 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6634 openfd = redir->rd_dup;
6637 if (openfd != redir->rd_fd) {
6638 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6639 if (openfd == REDIRFD_CLOSE) {
6640 /* "rd_fd >&-" means "close me" */
6642 /* ^^^ optimization: saving may already
6643 * have closed it. If not... */
6644 close(redir->rd_fd);
6647 xdup2(openfd, redir->rd_fd);
6648 if (redir->rd_dup == REDIRFD_TO_FILE)
6649 /* "rd_fd > FILE" */
6651 /* else: "rd_fd > rd_dup" */
6658 static char *find_in_path(const char *arg)
6661 const char *PATH = get_local_var_value("PATH");
6667 const char *end = strchrnul(PATH, ':');
6668 int sz = end - PATH; /* must be int! */
6672 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6674 /* We have xxx::yyyy in $PATH,
6675 * it means "use current dir" */
6678 if (access(ret, F_OK) == 0)
6691 static const struct built_in_command *find_builtin_helper(const char *name,
6692 const struct built_in_command *x,
6693 const struct built_in_command *end)
6696 if (strcmp(name, x->b_cmd) != 0) {
6700 debug_printf_exec("found builtin '%s'\n", name);
6705 static const struct built_in_command *find_builtin1(const char *name)
6707 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6709 static const struct built_in_command *find_builtin(const char *name)
6711 const struct built_in_command *x = find_builtin1(name);
6714 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6717 #if ENABLE_HUSH_FUNCTIONS
6718 static struct function **find_function_slot(const char *name)
6720 struct function **funcpp = &G.top_func;
6722 if (strcmp(name, (*funcpp)->name) == 0) {
6725 funcpp = &(*funcpp)->next;
6730 static const struct function *find_function(const char *name)
6732 const struct function *funcp = *find_function_slot(name);
6734 debug_printf_exec("found function '%s'\n", name);
6738 /* Note: takes ownership on name ptr */
6739 static struct function *new_function(char *name)
6741 struct function **funcpp = find_function_slot(name);
6742 struct function *funcp = *funcpp;
6744 if (funcp != NULL) {
6745 struct command *cmd = funcp->parent_cmd;
6746 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6748 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6750 /* Note: if !funcp->body, do not free body_as_string!
6751 * This is a special case of "-F name body" function:
6752 * body_as_string was not malloced! */
6754 free_pipe_list(funcp->body);
6756 free(funcp->body_as_string);
6760 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6761 cmd->argv[0] = funcp->name;
6762 cmd->group = funcp->body;
6764 cmd->group_as_string = funcp->body_as_string;
6768 debug_printf_exec("remembering new function '%s'\n", name);
6769 funcp = *funcpp = xzalloc(sizeof(*funcp));
6770 /*funcp->next = NULL;*/
6777 # if ENABLE_HUSH_UNSET
6778 static void unset_func(const char *name)
6780 struct function **funcpp = find_function_slot(name);
6781 struct function *funcp = *funcpp;
6783 if (funcp != NULL) {
6784 debug_printf_exec("freeing function '%s'\n", funcp->name);
6785 *funcpp = funcp->next;
6786 /* funcp is unlinked now, deleting it.
6787 * Note: if !funcp->body, the function was created by
6788 * "-F name body", do not free ->body_as_string
6789 * and ->name as they were not malloced. */
6791 free_pipe_list(funcp->body);
6794 free(funcp->body_as_string);
6803 #define exec_function(to_free, funcp, argv) \
6804 exec_function(funcp, argv)
6806 static void exec_function(char ***to_free,
6807 const struct function *funcp,
6808 char **argv) NORETURN;
6809 static void exec_function(char ***to_free,
6810 const struct function *funcp,
6816 argv[0] = G.global_argv[0];
6817 G.global_argv = argv;
6818 G.global_argc = n = 1 + string_array_len(argv + 1);
6819 /* On MMU, funcp->body is always non-NULL */
6820 n = run_list(funcp->body);
6824 re_execute_shell(to_free,
6825 funcp->body_as_string,
6832 static int run_function(const struct function *funcp, char **argv)
6838 save_and_replace_G_args(&sv, argv);
6840 /* "we are in function, ok to use return" */
6841 sv_flg = G_flag_return_in_progress;
6842 G_flag_return_in_progress = -1;
6843 # if ENABLE_HUSH_LOCAL
6844 G.func_nest_level++;
6847 /* On MMU, funcp->body is always non-NULL */
6850 /* Function defined by -F */
6851 parse_and_run_string(funcp->body_as_string);
6852 rc = G.last_exitcode;
6856 rc = run_list(funcp->body);
6859 # if ENABLE_HUSH_LOCAL
6861 struct variable *var;
6862 struct variable **var_pp;
6864 var_pp = &G.top_var;
6865 while ((var = *var_pp) != NULL) {
6866 if (var->func_nest_level < G.func_nest_level) {
6867 var_pp = &var->next;
6871 if (var->flg_export)
6872 bb_unsetenv(var->varstr);
6873 /* Remove from global list */
6874 *var_pp = var->next;
6880 G.func_nest_level--;
6883 G_flag_return_in_progress = sv_flg;
6885 restore_G_args(&sv, argv);
6889 #endif /* ENABLE_HUSH_FUNCTIONS */
6893 #define exec_builtin(to_free, x, argv) \
6894 exec_builtin(x, argv)
6896 #define exec_builtin(to_free, x, argv) \
6897 exec_builtin(to_free, argv)
6899 static void exec_builtin(char ***to_free,
6900 const struct built_in_command *x,
6901 char **argv) NORETURN;
6902 static void exec_builtin(char ***to_free,
6903 const struct built_in_command *x,
6909 rcode = x->b_function(argv);
6914 /* On NOMMU, we must never block!
6915 * Example: { sleep 99 | read line; } & echo Ok
6917 re_execute_shell(to_free,
6926 static void execvp_or_die(char **argv) NORETURN;
6927 static void execvp_or_die(char **argv)
6930 debug_printf_exec("execing '%s'\n", argv[0]);
6931 /* Don't propagate SIG_IGN to the child */
6932 if (SPECIAL_JOBSTOP_SIGS != 0)
6933 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6934 execvp(argv[0], argv);
6936 if (errno == EACCES) e = 126;
6937 if (errno == ENOENT) e = 127;
6938 bb_perror_msg("can't execute '%s'", argv[0]);
6942 #if ENABLE_HUSH_MODE_X
6943 static void dump_cmd_in_x_mode(char **argv)
6945 if (G_x_mode && argv) {
6946 /* We want to output the line in one write op */
6954 len += strlen(argv[n++]) + 1;
6960 p += sprintf(p, " %s", argv[n++]);
6968 # define dump_cmd_in_x_mode(argv) ((void)0)
6972 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6973 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6974 #define pseudo_exec(nommu_save, command, argv_expanded) \
6975 pseudo_exec(command, argv_expanded)
6978 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6980 * Don't exit() here. If you don't exec, use _exit instead.
6981 * The at_exit handlers apparently confuse the calling process,
6982 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6984 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6985 char **argv, int assignment_cnt,
6986 char **argv_expanded) NORETURN;
6987 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6988 char **argv, int assignment_cnt,
6989 char **argv_expanded)
6993 new_env = expand_assignments(argv, assignment_cnt);
6994 dump_cmd_in_x_mode(new_env);
6996 if (!argv[assignment_cnt]) {
6997 /* Case when we are here: ... | var=val | ...
6998 * (note that we do not exit early, i.e., do not optimize out
6999 * expand_assignments(): think about ... | var=`sleep 1` | ...
7001 free_strings(new_env);
7002 _exit(EXIT_SUCCESS);
7006 set_vars_and_save_old(new_env);
7007 free(new_env); /* optional */
7008 /* we can also destroy set_vars_and_save_old's return value,
7011 nommu_save->new_env = new_env;
7012 nommu_save->old_vars = set_vars_and_save_old(new_env);
7015 if (argv_expanded) {
7016 argv = argv_expanded;
7018 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7020 nommu_save->argv = argv;
7023 dump_cmd_in_x_mode(argv);
7025 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7026 if (strchr(argv[0], '/') != NULL)
7030 /* Check if the command matches any of the builtins.
7031 * Depending on context, this might be redundant. But it's
7032 * easier to waste a few CPU cycles than it is to figure out
7033 * if this is one of those cases.
7036 /* On NOMMU, it is more expensive to re-execute shell
7037 * just in order to run echo or test builtin.
7038 * It's better to skip it here and run corresponding
7039 * non-builtin later. */
7040 const struct built_in_command *x;
7041 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7043 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7046 #if ENABLE_HUSH_FUNCTIONS
7047 /* Check if the command matches any functions */
7049 const struct function *funcp = find_function(argv[0]);
7051 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7056 #if ENABLE_FEATURE_SH_STANDALONE
7057 /* Check if the command matches any busybox applets */
7059 int a = find_applet_by_name(argv[0]);
7061 # if BB_MMU /* see above why on NOMMU it is not allowed */
7062 if (APPLET_IS_NOEXEC(a)) {
7063 /* Do not leak open fds from opened script files etc */
7064 close_all_FILE_list();
7065 debug_printf_exec("running applet '%s'\n", argv[0]);
7066 run_applet_no_and_exit(a, argv[0], argv);
7069 /* Re-exec ourselves */
7070 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7071 /* Don't propagate SIG_IGN to the child */
7072 if (SPECIAL_JOBSTOP_SIGS != 0)
7073 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7074 execv(bb_busybox_exec_path, argv);
7075 /* If they called chroot or otherwise made the binary no longer
7076 * executable, fall through */
7081 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7084 execvp_or_die(argv);
7087 /* Called after [v]fork() in run_pipe
7089 static void pseudo_exec(nommu_save_t *nommu_save,
7090 struct command *command,
7091 char **argv_expanded) NORETURN;
7092 static void pseudo_exec(nommu_save_t *nommu_save,
7093 struct command *command,
7094 char **argv_expanded)
7096 if (command->argv) {
7097 pseudo_exec_argv(nommu_save, command->argv,
7098 command->assignment_cnt, argv_expanded);
7101 if (command->group) {
7102 /* Cases when we are here:
7105 * ... | ( list ) | ...
7106 * ... | { list } | ...
7110 debug_printf_exec("pseudo_exec: run_list\n");
7111 reset_traps_to_defaults();
7112 rcode = run_list(command->group);
7113 /* OK to leak memory by not calling free_pipe_list,
7114 * since this process is about to exit */
7117 re_execute_shell(&nommu_save->argv_from_re_execing,
7118 command->group_as_string,
7125 /* Case when we are here: ... | >file */
7126 debug_printf_exec("pseudo_exec'ed null command\n");
7127 _exit(EXIT_SUCCESS);
7131 static const char *get_cmdtext(struct pipe *pi)
7137 /* This is subtle. ->cmdtext is created only on first backgrounding.
7138 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7139 * On subsequent bg argv is trashed, but we won't use it */
7143 argv = pi->cmds[0].argv;
7145 pi->cmdtext = xzalloc(1);
7150 len += strlen(*argv) + 1;
7154 argv = pi->cmds[0].argv;
7156 p = stpcpy(p, *argv);
7163 static void insert_bg_job(struct pipe *pi)
7165 struct pipe *job, **jobp;
7168 /* Linear search for the ID of the job to use */
7170 for (job = G.job_list; job; job = job->next)
7171 if (job->jobid >= pi->jobid)
7172 pi->jobid = job->jobid + 1;
7174 /* Add job to the list of running jobs */
7176 while ((job = *jobp) != NULL)
7178 job = *jobp = xmalloc(sizeof(*job));
7180 *job = *pi; /* physical copy */
7182 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7183 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7184 for (i = 0; i < pi->num_cmds; i++) {
7185 job->cmds[i].pid = pi->cmds[i].pid;
7186 /* all other fields are not used and stay zero */
7188 job->cmdtext = xstrdup(get_cmdtext(pi));
7190 if (G_interactive_fd)
7191 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7192 G.last_jobid = job->jobid;
7195 static void remove_bg_job(struct pipe *pi)
7197 struct pipe *prev_pipe;
7199 if (pi == G.job_list) {
7200 G.job_list = pi->next;
7202 prev_pipe = G.job_list;
7203 while (prev_pipe->next != pi)
7204 prev_pipe = prev_pipe->next;
7205 prev_pipe->next = pi->next;
7208 G.last_jobid = G.job_list->jobid;
7213 /* Remove a backgrounded job */
7214 static void delete_finished_bg_job(struct pipe *pi)
7221 static int job_exited_or_stopped(struct pipe *pi)
7225 if (pi->alive_cmds != pi->stopped_cmds)
7228 /* All processes in fg pipe have exited or stopped */
7232 rcode = pi->cmds[i].cmd_exitcode;
7233 /* usually last process gives overall exitstatus,
7234 * but with "set -o pipefail", last *failed* process does */
7235 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7238 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7242 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7249 dead = WIFEXITED(status) || WIFSIGNALED(status);
7252 if (WIFSTOPPED(status))
7253 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7254 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7255 if (WIFSIGNALED(status))
7256 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7257 childpid, WTERMSIG(status), WEXITSTATUS(status));
7258 if (WIFEXITED(status))
7259 debug_printf_jobs("pid %d exited, exitcode %d\n",
7260 childpid, WEXITSTATUS(status));
7262 /* Were we asked to wait for a fg pipe? */
7264 i = fg_pipe->num_cmds;
7269 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7270 if (fg_pipe->cmds[i].pid != childpid)
7274 fg_pipe->cmds[i].pid = 0;
7275 fg_pipe->alive_cmds--;
7276 ex = WEXITSTATUS(status);
7277 /* bash prints killer signal's name for *last*
7278 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7279 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7281 if (WIFSIGNALED(status)) {
7282 int sig = WTERMSIG(status);
7283 if (i == fg_pipe->num_cmds-1)
7284 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7285 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7286 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7287 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7288 * Maybe we need to use sig | 128? */
7291 fg_pipe->cmds[i].cmd_exitcode = ex;
7293 fg_pipe->stopped_cmds++;
7295 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7296 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7297 rcode = job_exited_or_stopped(fg_pipe);
7299 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7300 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7301 * and "killall -STOP cat" */
7302 if (G_interactive_fd) {
7304 if (fg_pipe->alive_cmds != 0)
7305 insert_bg_job(fg_pipe);
7309 if (fg_pipe->alive_cmds == 0)
7312 /* There are still running processes in the fg_pipe */
7315 /* It wasn't in fg_pipe, look for process in bg pipes */
7319 /* We were asked to wait for bg or orphaned children */
7320 /* No need to remember exitcode in this case */
7321 for (pi = G.job_list; pi; pi = pi->next) {
7322 for (i = 0; i < pi->num_cmds; i++) {
7323 if (pi->cmds[i].pid == childpid)
7324 goto found_pi_and_prognum;
7327 /* Happens when shell is used as init process (init=/bin/sh) */
7328 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7329 return -1; /* this wasn't a process from fg_pipe */
7331 found_pi_and_prognum:
7334 pi->cmds[i].pid = 0;
7335 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7336 if (WIFSIGNALED(status))
7337 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7339 if (!pi->alive_cmds) {
7340 if (G_interactive_fd)
7341 printf(JOB_STATUS_FORMAT, pi->jobid,
7342 "Done", pi->cmdtext);
7343 delete_finished_bg_job(pi);
7350 return -1; /* this wasn't a process from fg_pipe */
7353 /* Check to see if any processes have exited -- if they have,
7354 * figure out why and see if a job has completed.
7356 * If non-NULL fg_pipe: wait for its completion or stop.
7357 * Return its exitcode or zero if stopped.
7359 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7360 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7361 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7362 * or 0 if no children changed status.
7364 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7365 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7366 * or 0 if no children changed status.
7368 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7374 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7376 attributes = WUNTRACED;
7377 if (fg_pipe == NULL)
7378 attributes |= WNOHANG;
7381 #if ENABLE_HUSH_FAST
7382 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7383 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7384 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7385 /* There was neither fork nor SIGCHLD since last waitpid */
7386 /* Avoid doing waitpid syscall if possible */
7387 if (!G.we_have_children) {
7391 if (fg_pipe == NULL) { /* is WNOHANG set? */
7392 /* We have children, but they did not exit
7393 * or stop yet (we saw no SIGCHLD) */
7396 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7400 /* Do we do this right?
7401 * bash-3.00# sleep 20 | false
7403 * [3]+ Stopped sleep 20 | false
7404 * bash-3.00# echo $?
7405 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7406 * [hush 1.14.0: yes we do it right]
7410 #if ENABLE_HUSH_FAST
7412 i = G.count_SIGCHLD;
7414 childpid = waitpid(-1, &status, attributes);
7415 if (childpid <= 0) {
7416 if (childpid && errno != ECHILD)
7417 bb_perror_msg("waitpid");
7418 #if ENABLE_HUSH_FAST
7419 else { /* Until next SIGCHLD, waitpid's are useless */
7420 G.we_have_children = (childpid == 0);
7421 G.handled_SIGCHLD = i;
7422 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7425 /* ECHILD (no children), or 0 (no change in children status) */
7429 rcode = process_wait_result(fg_pipe, childpid, status);
7431 /* fg_pipe exited or stopped */
7434 if (childpid == waitfor_pid) {
7435 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7436 rcode = WEXITSTATUS(status);
7437 if (WIFSIGNALED(status))
7438 rcode = 128 + WTERMSIG(status);
7439 if (WIFSTOPPED(status))
7440 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7441 rcode = 128 + WSTOPSIG(status);
7443 break; /* "wait PID" called us, give it exitcode+1 */
7445 /* This wasn't one of our processes, or */
7446 /* fg_pipe still has running processes, do waitpid again */
7447 } /* while (waitpid succeeds)... */
7453 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7456 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7457 if (G_saved_tty_pgrp) {
7458 /* Job finished, move the shell to the foreground */
7459 p = getpgrp(); /* our process group id */
7460 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7461 tcsetpgrp(G_interactive_fd, p);
7467 /* Start all the jobs, but don't wait for anything to finish.
7470 * Return code is normally -1, when the caller has to wait for children
7471 * to finish to determine the exit status of the pipe. If the pipe
7472 * is a simple builtin command, however, the action is done by the
7473 * time run_pipe returns, and the exit code is provided as the
7476 * Returns -1 only if started some children. IOW: we have to
7477 * mask out retvals of builtins etc with 0xff!
7479 * The only case when we do not need to [v]fork is when the pipe
7480 * is single, non-backgrounded, non-subshell command. Examples:
7481 * cmd ; ... { list } ; ...
7482 * cmd && ... { list } && ...
7483 * cmd || ... { list } || ...
7484 * If it is, then we can run cmd as a builtin, NOFORK,
7485 * or (if SH_STANDALONE) an applet, and we can run the { list }
7486 * with run_list. If it isn't one of these, we fork and exec cmd.
7488 * Cases when we must fork:
7489 * non-single: cmd | cmd
7490 * backgrounded: cmd & { list } &
7491 * subshell: ( list ) [&]
7493 #if !ENABLE_HUSH_MODE_X
7494 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7495 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7497 static int redirect_and_varexp_helper(char ***new_env_p,
7498 struct variable **old_vars_p,
7499 struct command *command,
7501 char **argv_expanded)
7503 /* setup_redirects acts on file descriptors, not FILEs.
7504 * This is perfect for work that comes after exec().
7505 * Is it really safe for inline use? Experimentally,
7506 * things seem to work. */
7507 int rcode = setup_redirects(command, squirrel);
7509 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7510 *new_env_p = new_env;
7511 dump_cmd_in_x_mode(new_env);
7512 dump_cmd_in_x_mode(argv_expanded);
7514 *old_vars_p = set_vars_and_save_old(new_env);
7518 static NOINLINE int run_pipe(struct pipe *pi)
7520 static const char *const null_ptr = NULL;
7524 struct command *command;
7525 char **argv_expanded;
7527 /* it is not always needed, but we aim to smaller code */
7528 int squirrel[] = { -1, -1, -1 };
7531 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7534 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7535 * Result should be 3 lines: q w e, qwe, q w e
7537 G.ifs = get_local_var_value("IFS");
7541 IF_HUSH_JOB(pi->pgrp = -1;)
7542 pi->stopped_cmds = 0;
7543 command = &pi->cmds[0];
7544 argv_expanded = NULL;
7546 if (pi->num_cmds != 1
7547 || pi->followup == PIPE_BG
7548 || command->cmd_type == CMD_SUBSHELL
7555 debug_printf_exec(": group:%p argv:'%s'\n",
7556 command->group, command->argv ? command->argv[0] : "NONE");
7558 if (command->group) {
7559 #if ENABLE_HUSH_FUNCTIONS
7560 if (command->cmd_type == CMD_FUNCDEF) {
7561 /* "executing" func () { list } */
7562 struct function *funcp;
7564 funcp = new_function(command->argv[0]);
7565 /* funcp->name is already set to argv[0] */
7566 funcp->body = command->group;
7568 funcp->body_as_string = command->group_as_string;
7569 command->group_as_string = NULL;
7571 command->group = NULL;
7572 command->argv[0] = NULL;
7573 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7574 funcp->parent_cmd = command;
7575 command->child_func = funcp;
7577 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7579 return EXIT_SUCCESS;
7583 debug_printf("non-subshell group\n");
7584 rcode = 1; /* exitcode if redir failed */
7585 if (setup_redirects(command, squirrel) == 0) {
7586 debug_printf_exec(": run_list\n");
7587 rcode = run_list(command->group) & 0xff;
7589 restore_redirects(squirrel);
7590 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7592 debug_printf_exec("run_pipe: return %d\n", rcode);
7596 argv = command->argv ? command->argv : (char **) &null_ptr;
7598 const struct built_in_command *x;
7599 #if ENABLE_HUSH_FUNCTIONS
7600 const struct function *funcp;
7604 char **new_env = NULL;
7605 struct variable *old_vars = NULL;
7607 if (argv[command->assignment_cnt] == NULL) {
7608 /* Assignments, but no command */
7609 /* Ensure redirects take effect (that is, create files).
7610 * Try "a=t >file" */
7611 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7612 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7613 /* Set shell variables */
7617 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7618 /* Do we need to flag set_local_var() errors?
7619 * "assignment to readonly var" and "putenv error"
7624 /* Redirect error sets $? to 1. Otherwise,
7625 * if evaluating assignment value set $?, retain it.
7626 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7628 rcode = G.last_exitcode;
7629 /* Exit, _skipping_ variable restoring code: */
7630 goto clean_up_and_ret0;
7632 #else /* Older, bigger, but more correct code */
7634 rcode = setup_redirects(command, squirrel);
7635 restore_redirects(squirrel);
7636 /* Set shell variables */
7638 bb_putchar_stderr('+');
7640 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7642 fprintf(stderr, " %s", p);
7643 debug_printf_exec("set shell var:'%s'->'%s'\n",
7645 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7646 /* Do we need to flag set_local_var() errors?
7647 * "assignment to readonly var" and "putenv error"
7652 bb_putchar_stderr('\n');
7653 /* Redirect error sets $? to 1. Otherwise,
7654 * if evaluating assignment value set $?, retain it.
7655 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7657 rcode = G.last_exitcode;
7658 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7660 debug_printf_exec("run_pipe: return %d\n", rcode);
7665 /* Expand the rest into (possibly) many strings each */
7667 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7668 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7672 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7675 /* if someone gives us an empty string: `cmd with empty output` */
7676 if (!argv_expanded[0]) {
7677 free(argv_expanded);
7679 return G.last_exitcode;
7682 x = find_builtin(argv_expanded[0]);
7683 #if ENABLE_HUSH_FUNCTIONS
7686 funcp = find_function(argv_expanded[0]);
7690 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7691 debug_printf("exec with redirects only\n");
7692 rcode = setup_redirects(command, NULL);
7693 /* rcode=1 can be if redir file can't be opened */
7694 goto clean_up_and_ret1;
7697 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7700 debug_printf_exec(": builtin '%s' '%s'...\n",
7701 x->b_cmd, argv_expanded[1]);
7703 rcode = x->b_function(argv_expanded) & 0xff;
7706 #if ENABLE_HUSH_FUNCTIONS
7708 # if ENABLE_HUSH_LOCAL
7709 struct variable **sv;
7710 sv = G.shadowed_vars_pp;
7711 G.shadowed_vars_pp = &old_vars;
7713 debug_printf_exec(": function '%s' '%s'...\n",
7714 funcp->name, argv_expanded[1]);
7715 rcode = run_function(funcp, argv_expanded) & 0xff;
7716 # if ENABLE_HUSH_LOCAL
7717 G.shadowed_vars_pp = sv;
7723 unset_vars(new_env);
7725 /* clean_up_and_ret0: */
7727 //FIXME: this restores stdio fds, but does not close other redirects!
7728 //Example: after "echo TEST 9>/dev/null" fd#9 is not closed!
7729 //The squirreling code needs rework to remember all fds, not just 0,1,2.
7730 restore_redirects(squirrel);
7732 free(argv_expanded);
7733 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7735 debug_printf_exec("run_pipe return %d\n", rcode);
7739 if (ENABLE_FEATURE_SH_NOFORK) {
7740 int n = find_applet_by_name(argv_expanded[0]);
7741 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7742 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7744 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7745 argv_expanded[0], argv_expanded[1]);
7746 rcode = run_nofork_applet(n, argv_expanded);
7748 goto clean_up_and_ret;
7751 /* It is neither builtin nor applet. We must fork. */
7755 /* NB: argv_expanded may already be created, and that
7756 * might include `cmd` runs! Do not rerun it! We *must*
7757 * use argv_expanded if it's non-NULL */
7759 /* Going to fork a child per each pipe member */
7764 while (cmd_no < pi->num_cmds) {
7765 struct fd_pair pipefds;
7767 volatile nommu_save_t nommu_save;
7768 nommu_save.new_env = NULL;
7769 nommu_save.old_vars = NULL;
7770 nommu_save.argv = NULL;
7771 nommu_save.argv_from_re_execing = NULL;
7773 command = &pi->cmds[cmd_no];
7775 if (command->argv) {
7776 debug_printf_exec(": pipe member '%s' '%s'...\n",
7777 command->argv[0], command->argv[1]);
7779 debug_printf_exec(": pipe member with no argv\n");
7782 /* pipes are inserted between pairs of commands */
7785 if (cmd_no < pi->num_cmds)
7786 xpiped_pair(pipefds);
7788 command->pid = BB_MMU ? fork() : vfork();
7789 if (!command->pid) { /* child */
7791 disable_restore_tty_pgrp_on_exit();
7792 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7794 /* Every child adds itself to new process group
7795 * with pgid == pid_of_first_child_in_pipe */
7796 if (G.run_list_level == 1 && G_interactive_fd) {
7799 if (pgrp < 0) /* true for 1st process only */
7801 if (setpgid(0, pgrp) == 0
7802 && pi->followup != PIPE_BG
7803 && G_saved_tty_pgrp /* we have ctty */
7805 /* We do it in *every* child, not just first,
7807 tcsetpgrp(G_interactive_fd, pgrp);
7811 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7812 /* 1st cmd in backgrounded pipe
7813 * should have its stdin /dev/null'ed */
7815 if (open(bb_dev_null, O_RDONLY))
7816 xopen("/", O_RDONLY);
7818 xmove_fd(next_infd, 0);
7820 xmove_fd(pipefds.wr, 1);
7823 /* Like bash, explicit redirects override pipes,
7824 * and the pipe fd (fd#1) is available for dup'ing:
7825 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7826 * of cmd1 goes into pipe.
7828 if (setup_redirects(command, NULL)) {
7829 /* Happens when redir file can't be opened:
7830 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7832 * hush: can't open '/qwe/rty': No such file or directory
7834 * (echo BAR is not executed, it hits _exit(1) below)
7839 /* Stores to nommu_save list of env vars putenv'ed
7840 * (NOMMU, on MMU we don't need that) */
7841 /* cast away volatility... */
7842 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7843 /* pseudo_exec() does not return */
7846 /* parent or error */
7847 #if ENABLE_HUSH_FAST
7849 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7851 enable_restore_tty_pgrp_on_exit();
7853 /* Clean up after vforked child */
7854 free(nommu_save.argv);
7855 free(nommu_save.argv_from_re_execing);
7856 unset_vars(nommu_save.new_env);
7857 add_vars(nommu_save.old_vars);
7859 free(argv_expanded);
7860 argv_expanded = NULL;
7861 if (command->pid < 0) { /* [v]fork failed */
7862 /* Clearly indicate, was it fork or vfork */
7863 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7867 /* Second and next children need to know pid of first one */
7869 pi->pgrp = command->pid;
7875 if (cmd_no < pi->num_cmds)
7877 /* Pass read (output) pipe end to next iteration */
7878 next_infd = pipefds.rd;
7881 if (!pi->alive_cmds) {
7883 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7888 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7892 /* NB: called by pseudo_exec, and therefore must not modify any
7893 * global data until exec/_exit (we can be a child after vfork!) */
7894 static int run_list(struct pipe *pi)
7896 #if ENABLE_HUSH_CASE
7897 char *case_word = NULL;
7899 #if ENABLE_HUSH_LOOPS
7900 struct pipe *loop_top = NULL;
7901 char **for_lcur = NULL;
7902 char **for_list = NULL;
7904 smallint last_followup;
7906 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7907 smalluint cond_code = 0;
7909 enum { cond_code = 0 };
7912 smallint rword; /* RES_foo */
7913 smallint last_rword; /* ditto */
7916 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7919 #if ENABLE_HUSH_LOOPS
7920 /* Check syntax for "for" */
7923 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7924 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7926 /* current word is FOR or IN (BOLD in comments below) */
7927 if (cpipe->next == NULL) {
7928 syntax_error("malformed for");
7930 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7933 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7934 if (cpipe->next->res_word == RES_DO)
7936 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7937 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7938 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7940 syntax_error("malformed for");
7942 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7949 /* Past this point, all code paths should jump to ret: label
7950 * in order to return, no direct "return" statements please.
7951 * This helps to ensure that no memory is leaked. */
7959 last_rword = RES_XXXX;
7961 last_followup = PIPE_SEQ;
7962 rcode = G.last_exitcode;
7964 /* Go through list of pipes, (maybe) executing them. */
7965 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7970 if (G_flag_return_in_progress == 1)
7973 IF_HAS_KEYWORDS(rword = pi->res_word;)
7974 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7975 rword, cond_code, last_rword);
7976 #if ENABLE_HUSH_LOOPS
7977 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7978 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7980 /* start of a loop: remember where loop starts */
7985 /* Still in the same "if...", "then..." or "do..." branch? */
7986 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7987 if ((rcode == 0 && last_followup == PIPE_OR)
7988 || (rcode != 0 && last_followup == PIPE_AND)
7990 /* It is "<true> || CMD" or "<false> && CMD"
7991 * and we should not execute CMD */
7992 debug_printf_exec("skipped cmd because of || or &&\n");
7993 last_followup = pi->followup;
7994 goto dont_check_jobs_but_continue;
7997 last_followup = pi->followup;
7998 IF_HAS_KEYWORDS(last_rword = rword;)
8001 if (rword == RES_THEN) {
8002 /* if false; then ... fi has exitcode 0! */
8003 G.last_exitcode = rcode = EXIT_SUCCESS;
8004 /* "if <false> THEN cmd": skip cmd */
8008 if (rword == RES_ELSE || rword == RES_ELIF) {
8009 /* "if <true> then ... ELSE/ELIF cmd":
8010 * skip cmd and all following ones */
8015 #if ENABLE_HUSH_LOOPS
8016 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8018 /* first loop through for */
8020 static const char encoded_dollar_at[] ALIGN1 = {
8021 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8022 }; /* encoded representation of "$@" */
8023 static const char *const encoded_dollar_at_argv[] = {
8024 encoded_dollar_at, NULL
8025 }; /* argv list with one element: "$@" */
8028 vals = (char**)encoded_dollar_at_argv;
8029 if (pi->next->res_word == RES_IN) {
8030 /* if no variable values after "in" we skip "for" */
8031 if (!pi->next->cmds[0].argv) {
8032 G.last_exitcode = rcode = EXIT_SUCCESS;
8033 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8036 vals = pi->next->cmds[0].argv;
8037 } /* else: "for var; do..." -> assume "$@" list */
8038 /* create list of variable values */
8039 debug_print_strings("for_list made from", vals);
8040 for_list = expand_strvec_to_strvec(vals);
8041 for_lcur = for_list;
8042 debug_print_strings("for_list", for_list);
8045 /* "for" loop is over, clean up */
8051 /* Insert next value from for_lcur */
8052 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8053 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8056 if (rword == RES_IN) {
8057 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8059 if (rword == RES_DONE) {
8060 continue; /* "done" has no cmds too */
8063 #if ENABLE_HUSH_CASE
8064 if (rword == RES_CASE) {
8065 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8066 case_word = expand_strvec_to_string(pi->cmds->argv);
8067 unbackslash(case_word);
8070 if (rword == RES_MATCH) {
8073 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8074 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8076 /* all prev words didn't match, does this one match? */
8077 argv = pi->cmds->argv;
8079 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8080 /* TODO: which FNM_xxx flags to use? */
8081 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8082 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8084 if (cond_code == 0) { /* match! we will execute this branch */
8086 case_word = NULL; /* make future "word)" stop */
8093 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8094 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8096 continue; /* not matched yet, skip this pipe */
8098 if (rword == RES_ESAC) {
8099 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8101 /* "case" did not match anything: still set $? (to 0) */
8102 G.last_exitcode = rcode = EXIT_SUCCESS;
8106 /* Just pressing <enter> in shell should check for jobs.
8107 * OTOH, in non-interactive shell this is useless
8108 * and only leads to extra job checks */
8109 if (pi->num_cmds == 0) {
8110 if (G_interactive_fd)
8111 goto check_jobs_and_continue;
8115 /* After analyzing all keywords and conditions, we decided
8116 * to execute this pipe. NB: have to do checkjobs(NULL)
8117 * after run_pipe to collect any background children,
8118 * even if list execution is to be stopped. */
8119 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8120 #if ENABLE_HUSH_LOOPS
8121 G.flag_break_continue = 0;
8123 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8125 /* We ran a builtin, function, or group.
8126 * rcode is already known
8127 * and we don't need to wait for anything. */
8128 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8129 G.last_exitcode = rcode;
8130 check_and_run_traps();
8131 #if ENABLE_HUSH_LOOPS
8132 /* Was it "break" or "continue"? */
8133 if (G.flag_break_continue) {
8134 smallint fbc = G.flag_break_continue;
8135 /* We might fall into outer *loop*,
8136 * don't want to break it too */
8138 G.depth_break_continue--;
8139 if (G.depth_break_continue == 0)
8140 G.flag_break_continue = 0;
8141 /* else: e.g. "continue 2" should *break* once, *then* continue */
8142 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8143 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8144 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8147 /* "continue": simulate end of loop */
8152 if (G_flag_return_in_progress == 1) {
8153 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8156 } else if (pi->followup == PIPE_BG) {
8157 /* What does bash do with attempts to background builtins? */
8158 /* even bash 3.2 doesn't do that well with nested bg:
8159 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8160 * I'm NOT treating inner &'s as jobs */
8162 if (G.run_list_level == 1)
8165 /* Last command's pid goes to $! */
8166 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8167 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8168 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8169 rcode = EXIT_SUCCESS;
8173 if (G.run_list_level == 1 && G_interactive_fd) {
8174 /* Waits for completion, then fg's main shell */
8175 rcode = checkjobs_and_fg_shell(pi);
8176 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8180 /* This one just waits for completion */
8181 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8182 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8184 G.last_exitcode = rcode;
8185 check_and_run_traps();
8188 /* Analyze how result affects subsequent commands */
8190 if (rword == RES_IF || rword == RES_ELIF)
8193 check_jobs_and_continue:
8194 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8195 dont_check_jobs_but_continue: ;
8196 #if ENABLE_HUSH_LOOPS
8197 /* Beware of "while false; true; do ..."! */
8199 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8200 /* check for RES_DONE is needed for "while ...; do \n done" case */
8202 if (rword == RES_WHILE) {
8204 /* "while false; do...done" - exitcode 0 */
8205 G.last_exitcode = rcode = EXIT_SUCCESS;
8206 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8210 if (rword == RES_UNTIL) {
8212 debug_printf_exec(": until expr is true: breaking\n");
8223 #if ENABLE_HUSH_LOOPS
8228 #if ENABLE_HUSH_CASE
8232 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8236 /* Select which version we will use */
8237 static int run_and_free_list(struct pipe *pi)
8240 debug_printf_exec("run_and_free_list entered\n");
8241 if (!G.o_opt[OPT_O_NOEXEC]) {
8242 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8243 rcode = run_list(pi);
8245 /* free_pipe_list has the side effect of clearing memory.
8246 * In the long run that function can be merged with run_list,
8247 * but doing that now would hobble the debugging effort. */
8249 debug_printf_exec("run_and_free_list return %d\n", rcode);
8254 static void install_sighandlers(unsigned mask)
8256 sighandler_t old_handler;
8258 while ((mask >>= 1) != 0) {
8262 old_handler = install_sighandler(sig, pick_sighandler(sig));
8263 /* POSIX allows shell to re-enable SIGCHLD
8264 * even if it was SIG_IGN on entry.
8265 * Therefore we skip IGN check for it:
8269 if (old_handler == SIG_IGN) {
8270 /* oops... restore back to IGN, and record this fact */
8271 install_sighandler(sig, old_handler);
8272 #if ENABLE_HUSH_TRAP
8274 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8276 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8282 /* Called a few times only (or even once if "sh -c") */
8283 static void install_special_sighandlers(void)
8287 /* Which signals are shell-special? */
8288 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8289 if (G_interactive_fd) {
8290 mask |= SPECIAL_INTERACTIVE_SIGS;
8291 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8292 mask |= SPECIAL_JOBSTOP_SIGS;
8294 /* Careful, do not re-install handlers we already installed */
8295 if (G.special_sig_mask != mask) {
8296 unsigned diff = mask & ~G.special_sig_mask;
8297 G.special_sig_mask = mask;
8298 install_sighandlers(diff);
8304 /* Set handlers to restore tty pgrp and exit */
8305 static void install_fatal_sighandlers(void)
8309 /* We will restore tty pgrp on these signals */
8311 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8312 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8313 + (1 << SIGBUS ) * HUSH_DEBUG
8314 + (1 << SIGSEGV) * HUSH_DEBUG
8315 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8317 /* bash 3.2 seems to handle these just like 'fatal' ones */
8320 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8321 * if we aren't interactive... but in this case
8322 * we never want to restore pgrp on exit, and this fn is not called
8324 /*+ (1 << SIGHUP )*/
8325 /*+ (1 << SIGTERM)*/
8326 /*+ (1 << SIGINT )*/
8328 G_fatal_sig_mask = mask;
8330 install_sighandlers(mask);
8334 static int set_mode(int state, char mode, const char *o_opt)
8339 G.o_opt[OPT_O_NOEXEC] = state;
8342 IF_HUSH_MODE_X(G_x_mode = state;)
8346 /* "set -+o" without parameter.
8347 * in bash, set -o produces this output:
8351 * We always use the second form.
8353 const char *p = o_opt_strings;
8356 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8362 idx = index_in_strings(o_opt_strings, o_opt);
8364 G.o_opt[idx] = state;
8368 return EXIT_FAILURE;
8370 return EXIT_SUCCESS;
8373 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8374 int hush_main(int argc, char **argv)
8377 OPT_login = (1 << 0),
8381 unsigned builtin_argc;
8383 struct variable *cur_var;
8384 struct variable *shell_ver;
8387 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8388 G.last_exitcode = EXIT_SUCCESS;
8390 #if ENABLE_HUSH_FAST
8391 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8394 G.argv0_for_re_execing = argv[0];
8396 /* Deal with HUSH_VERSION */
8397 shell_ver = xzalloc(sizeof(*shell_ver));
8398 shell_ver->flg_export = 1;
8399 shell_ver->flg_read_only = 1;
8400 /* Code which handles ${var<op>...} needs writable values for all variables,
8401 * therefore we xstrdup: */
8402 shell_ver->varstr = xstrdup(hush_version_str);
8403 /* Create shell local variables from the values
8404 * currently living in the environment */
8405 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8406 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8407 G.top_var = shell_ver;
8408 cur_var = G.top_var;
8411 char *value = strchr(*e, '=');
8412 if (value) { /* paranoia */
8413 cur_var->next = xzalloc(sizeof(*cur_var));
8414 cur_var = cur_var->next;
8415 cur_var->varstr = *e;
8416 cur_var->max_len = strlen(*e);
8417 cur_var->flg_export = 1;
8421 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8422 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8423 putenv(shell_ver->varstr);
8426 set_pwd_var(/*exp:*/ 1);
8428 #if BASH_HOSTNAME_VAR
8429 /* Set (but not export) HOSTNAME unless already set */
8430 if (!get_local_var_value("HOSTNAME")) {
8433 set_local_var_from_halves("HOSTNAME", uts.nodename);
8435 /* bash also exports SHLVL and _,
8436 * and sets (but doesn't export) the following variables:
8438 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8439 * BASH_VERSION='3.2.0(1)-release'
8441 * MACHTYPE=i386-pc-linux-gnu
8443 * PPID=<NNNNN> - we also do it elsewhere
8454 * PIPESTATUS=([0]="0")
8455 * HISTFILE=/<xxx>/.bash_history
8459 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8461 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8472 #if ENABLE_FEATURE_EDITING
8473 G.line_input_state = new_line_input_t(FOR_SHELL);
8476 /* Initialize some more globals to non-zero values */
8477 cmdedit_update_prompt();
8479 die_func = restore_ttypgrp_and__exit;
8481 /* Shell is non-interactive at first. We need to call
8482 * install_special_sighandlers() if we are going to execute "sh <script>",
8483 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8484 * If we later decide that we are interactive, we run install_special_sighandlers()
8485 * in order to intercept (more) signals.
8489 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8490 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8493 opt = getopt(argc, argv, "+c:xinsl"
8496 # if ENABLE_HUSH_FUNCTIONS
8506 * sh ... -c 'script'
8507 * sh ... -c 'script' ARG0 [ARG1...]
8508 * On NOMMU, if builtin_argc != 0,
8509 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8510 * "" needs to be replaced with NULL
8511 * and BARGV vector fed to builtin function.
8512 * Note: the form without ARG0 never happens:
8513 * sh ... -c 'builtin' BARGV... ""
8516 G.root_pid = getpid();
8517 G.root_ppid = getppid();
8519 G.global_argv = argv + optind;
8520 G.global_argc = argc - optind;
8522 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8523 const struct built_in_command *x;
8525 install_special_sighandlers();
8526 x = find_builtin(optarg);
8527 if (x) { /* paranoia */
8528 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8529 G.global_argv += builtin_argc;
8530 G.global_argv[-1] = NULL; /* replace "" */
8532 G.last_exitcode = x->b_function(argv + optind - 1);
8536 if (!G.global_argv[0]) {
8537 /* -c 'script' (no params): prevent empty $0 */
8538 G.global_argv--; /* points to argv[i] of 'script' */
8539 G.global_argv[0] = argv[0];
8541 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8542 install_special_sighandlers();
8543 parse_and_run_string(optarg);
8546 /* Well, we cannot just declare interactiveness,
8547 * we have to have some stuff (ctty, etc) */
8548 /* G_interactive_fd++; */
8551 /* "-s" means "read from stdin", but this is how we always
8552 * operate, so simply do nothing here. */
8558 case '<': /* "big heredoc" support */
8559 full_write1_str(optarg);
8562 unsigned long long empty_trap_mask;
8564 G.root_pid = bb_strtou(optarg, &optarg, 16);
8566 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8568 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8570 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8572 builtin_argc = bb_strtou(optarg, &optarg, 16);
8574 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8575 if (empty_trap_mask != 0) {
8576 IF_HUSH_TRAP(int sig;)
8577 install_special_sighandlers();
8578 # if ENABLE_HUSH_TRAP
8579 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8580 for (sig = 1; sig < NSIG; sig++) {
8581 if (empty_trap_mask & (1LL << sig)) {
8582 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8583 install_sighandler(sig, SIG_IGN);
8588 # if ENABLE_HUSH_LOOPS
8590 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8596 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8598 # if ENABLE_HUSH_FUNCTIONS
8600 struct function *funcp = new_function(optarg);
8601 /* funcp->name is already set to optarg */
8602 /* funcp->body is set to NULL. It's a special case. */
8603 funcp->body_as_string = argv[optind];
8611 if (set_mode(1, opt, NULL) == 0) /* no error */
8615 fprintf(stderr, "Usage: sh [FILE]...\n"
8616 " or: sh -c command [args]...\n\n");
8622 } /* option parsing loop */
8624 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8625 G.global_argc = argc - (optind - 1);
8626 G.global_argv = argv + (optind - 1);
8627 G.global_argv[0] = argv[0];
8630 G.root_pid = getpid();
8631 G.root_ppid = getppid();
8634 /* If we are login shell... */
8635 if (flags & OPT_login) {
8637 debug_printf("sourcing /etc/profile\n");
8638 input = fopen_for_read("/etc/profile");
8639 if (input != NULL) {
8640 remember_FILE(input);
8641 install_special_sighandlers();
8642 parse_and_run_file(input);
8643 fclose_and_forget(input);
8645 /* bash: after sourcing /etc/profile,
8646 * tries to source (in the given order):
8647 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8648 * stopping on first found. --noprofile turns this off.
8649 * bash also sources ~/.bash_logout on exit.
8650 * If called as sh, skips .bash_XXX files.
8654 if (G.global_argv[1]) {
8657 * "bash <script>" (which is never interactive (unless -i?))
8658 * sources $BASH_ENV here (without scanning $PATH).
8659 * If called as sh, does the same but with $ENV.
8660 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8664 debug_printf("running script '%s'\n", G.global_argv[0]);
8665 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8666 input = xfopen_for_read(G.global_argv[0]);
8667 xfunc_error_retval = 1;
8668 remember_FILE(input);
8669 install_special_sighandlers();
8670 parse_and_run_file(input);
8671 #if ENABLE_FEATURE_CLEAN_UP
8672 fclose_and_forget(input);
8677 /* Up to here, shell was non-interactive. Now it may become one.
8678 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8681 /* A shell is interactive if the '-i' flag was given,
8682 * or if all of the following conditions are met:
8684 * no arguments remaining or the -s flag given
8685 * standard input is a terminal
8686 * standard output is a terminal
8687 * Refer to Posix.2, the description of the 'sh' utility.
8690 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8691 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8692 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8693 if (G_saved_tty_pgrp < 0)
8694 G_saved_tty_pgrp = 0;
8696 /* try to dup stdin to high fd#, >= 255 */
8697 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8698 if (G_interactive_fd < 0) {
8699 /* try to dup to any fd */
8700 G_interactive_fd = dup(STDIN_FILENO);
8701 if (G_interactive_fd < 0) {
8703 G_interactive_fd = 0;
8704 G_saved_tty_pgrp = 0;
8707 // TODO: track & disallow any attempts of user
8708 // to (inadvertently) close/redirect G_interactive_fd
8710 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8711 if (G_interactive_fd) {
8712 close_on_exec_on(G_interactive_fd);
8714 if (G_saved_tty_pgrp) {
8715 /* If we were run as 'hush &', sleep until we are
8716 * in the foreground (tty pgrp == our pgrp).
8717 * If we get started under a job aware app (like bash),
8718 * make sure we are now in charge so we don't fight over
8719 * who gets the foreground */
8721 pid_t shell_pgrp = getpgrp();
8722 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8723 if (G_saved_tty_pgrp == shell_pgrp)
8725 /* send TTIN to ourself (should stop us) */
8726 kill(- shell_pgrp, SIGTTIN);
8730 /* Install more signal handlers */
8731 install_special_sighandlers();
8733 if (G_saved_tty_pgrp) {
8734 /* Set other signals to restore saved_tty_pgrp */
8735 install_fatal_sighandlers();
8736 /* Put ourselves in our own process group
8737 * (bash, too, does this only if ctty is available) */
8738 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8739 /* Grab control of the terminal */
8740 tcsetpgrp(G_interactive_fd, getpid());
8742 enable_restore_tty_pgrp_on_exit();
8744 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8746 const char *hp = get_local_var_value("HISTFILE");
8748 hp = get_local_var_value("HOME");
8750 hp = concat_path_file(hp, ".hush_history");
8755 G.line_input_state->hist_file = hp;
8756 //set_local_var(xasprintf("HISTFILE=%s", ...));
8758 # if ENABLE_FEATURE_SH_HISTFILESIZE
8759 hp = get_local_var_value("HISTFILESIZE");
8760 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8765 install_special_sighandlers();
8767 #elif ENABLE_HUSH_INTERACTIVE
8768 /* No job control compiled in, only prompt/line editing */
8769 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8770 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8771 if (G_interactive_fd < 0) {
8772 /* try to dup to any fd */
8773 G_interactive_fd = dup(STDIN_FILENO);
8774 if (G_interactive_fd < 0)
8776 G_interactive_fd = 0;
8779 if (G_interactive_fd) {
8780 close_on_exec_on(G_interactive_fd);
8782 install_special_sighandlers();
8784 /* We have interactiveness code disabled */
8785 install_special_sighandlers();
8788 * if interactive but not a login shell, sources ~/.bashrc
8789 * (--norc turns this off, --rcfile <file> overrides)
8792 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8793 /* note: ash and hush share this string */
8794 printf("\n\n%s %s\n"
8795 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8798 "hush - the humble shell"
8802 parse_and_run_file(stdin);
8805 hush_exit(G.last_exitcode);
8812 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8817 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8818 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8820 int argc = string_array_len(argv);
8821 return applet_main_func(argc, argv);
8824 #if ENABLE_HUSH_TEST || BASH_TEST2
8825 static int FAST_FUNC builtin_test(char **argv)
8827 return run_applet_main(argv, test_main);
8830 #if ENABLE_HUSH_ECHO
8831 static int FAST_FUNC builtin_echo(char **argv)
8833 return run_applet_main(argv, echo_main);
8836 #if ENABLE_HUSH_PRINTF
8837 static int FAST_FUNC builtin_printf(char **argv)
8839 return run_applet_main(argv, printf_main);
8843 #if ENABLE_HUSH_HELP
8844 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8846 const struct built_in_command *x;
8849 "Built-in commands:\n"
8850 "------------------\n");
8851 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8853 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8855 return EXIT_SUCCESS;
8859 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8860 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8862 show_history(G.line_input_state);
8863 return EXIT_SUCCESS;
8867 static char **skip_dash_dash(char **argv)
8870 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8875 static int FAST_FUNC builtin_cd(char **argv)
8879 argv = skip_dash_dash(argv);
8881 if (newdir == NULL) {
8882 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8883 * bash says "bash: cd: HOME not set" and does nothing
8886 const char *home = get_local_var_value("HOME");
8887 newdir = home ? home : "/";
8889 if (chdir(newdir)) {
8890 /* Mimic bash message exactly */
8891 bb_perror_msg("cd: %s", newdir);
8892 return EXIT_FAILURE;
8894 /* Read current dir (get_cwd(1) is inside) and set PWD.
8895 * Note: do not enforce exporting. If PWD was unset or unexported,
8896 * set it again, but do not export. bash does the same.
8898 set_pwd_var(/*exp:*/ 0);
8899 return EXIT_SUCCESS;
8902 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8905 return EXIT_SUCCESS;
8908 static int FAST_FUNC builtin_eval(char **argv)
8910 int rcode = EXIT_SUCCESS;
8912 argv = skip_dash_dash(argv);
8914 char *str = expand_strvec_to_string(argv);
8916 * eval "echo Hi; done" ("done" is syntax error):
8917 * "echo Hi" will not execute too.
8919 parse_and_run_string(str);
8921 rcode = G.last_exitcode;
8926 static int FAST_FUNC builtin_exec(char **argv)
8928 argv = skip_dash_dash(argv);
8929 if (argv[0] == NULL)
8930 return EXIT_SUCCESS; /* bash does this */
8932 /* Careful: we can end up here after [v]fork. Do not restore
8933 * tty pgrp then, only top-level shell process does that */
8934 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8935 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8937 /* TODO: if exec fails, bash does NOT exit! We do.
8938 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8939 * and tcsetpgrp, and this is inherently racy.
8941 execvp_or_die(argv);
8944 static int FAST_FUNC builtin_exit(char **argv)
8946 debug_printf_exec("%s()\n", __func__);
8948 /* interactive bash:
8949 * # trap "echo EEE" EXIT
8952 * There are stopped jobs.
8953 * (if there are _stopped_ jobs, running ones don't count)
8956 * EEE (then bash exits)
8958 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8961 /* note: EXIT trap is run by hush_exit */
8962 argv = skip_dash_dash(argv);
8963 if (argv[0] == NULL)
8964 hush_exit(G.last_exitcode);
8965 /* mimic bash: exit 123abc == exit 255 + error msg */
8966 xfunc_error_retval = 255;
8967 /* bash: exit -2 == exit 254, no error msg */
8968 hush_exit(xatoi(argv[0]) & 0xff);
8971 #if ENABLE_HUSH_TYPE
8972 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8973 static int FAST_FUNC builtin_type(char **argv)
8975 int ret = EXIT_SUCCESS;
8981 if (0) {} /* make conditional compile easier below */
8982 /*else if (find_alias(*argv))
8983 type = "an alias";*/
8984 #if ENABLE_HUSH_FUNCTIONS
8985 else if (find_function(*argv))
8986 type = "a function";
8988 else if (find_builtin(*argv))
8989 type = "a shell builtin";
8990 else if ((path = find_in_path(*argv)) != NULL)
8993 bb_error_msg("type: %s: not found", *argv);
8998 printf("%s is %s\n", *argv, type);
9006 #if ENABLE_HUSH_READ
9007 /* Interruptibility of read builtin in bash
9008 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9010 * Empty trap makes read ignore corresponding signal, for any signal.
9013 * - terminates non-interactive shell;
9014 * - interrupts read in interactive shell;
9015 * if it has non-empty trap:
9016 * - executes trap and returns to command prompt in interactive shell;
9017 * - executes trap and returns to read in non-interactive shell;
9019 * - is ignored (does not interrupt) read in interactive shell;
9020 * - terminates non-interactive shell;
9021 * if it has non-empty trap:
9022 * - executes trap and returns to read;
9024 * - terminates shell (regardless of interactivity);
9025 * if it has non-empty trap:
9026 * - executes trap and returns to read;
9027 * SIGCHLD from children:
9028 * - does not interrupt read regardless of interactivity:
9029 * try: sleep 1 & read x; echo $x
9031 static int FAST_FUNC builtin_read(char **argv)
9041 /* "!": do not abort on errors.
9042 * Option string must start with "sr" to match BUILTIN_READ_xxx
9044 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9045 if (read_flags == (uint32_t)-1)
9046 return EXIT_FAILURE;
9048 ifs = get_local_var_value("IFS"); /* can be NULL */
9051 r = shell_builtin_read(set_local_var_from_halves,
9061 if ((uintptr_t)r == 1 && errno == EINTR) {
9062 unsigned sig = check_and_run_traps();
9067 if ((uintptr_t)r > 1) {
9068 bb_error_msg("%s", r);
9069 r = (char*)(uintptr_t)1;
9072 return (uintptr_t)r;
9076 #if ENABLE_HUSH_UMASK
9077 static int FAST_FUNC builtin_umask(char **argv)
9084 argv = skip_dash_dash(argv);
9086 mode_t old_mask = mask;
9088 /* numeric umasks are taken as-is */
9089 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9090 if (!isdigit(argv[0][0]))
9092 mask = bb_parse_mode(argv[0], mask);
9093 if (!isdigit(argv[0][0]))
9095 if ((unsigned)mask > 0777) {
9098 * bash: umask: 'q': invalid symbolic mode operator
9099 * bash: umask: 999: octal number out of range
9101 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9106 printf("%04o\n", (unsigned) mask);
9107 /* fall through and restore mask which we set to 0 */
9111 return !rc; /* rc != 0 - success */
9115 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9116 static void print_escaped(const char *s)
9121 const char *p = strchrnul(s, '\'');
9122 /* print 'xxxx', possibly just '' */
9123 printf("'%.*s'", (int)(p - s), s);
9128 /* s points to '; print "'''...'''" */
9130 do putchar('\''); while (*++s == '\'');
9136 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9137 # if !ENABLE_HUSH_LOCAL
9138 #define helper_export_local(argv, exp, lvl) \
9139 helper_export_local(argv, exp)
9141 static void helper_export_local(char **argv, int exp, int lvl)
9145 char *name_end = strchrnul(name, '=');
9147 /* So far we do not check that name is valid (TODO?) */
9149 if (*name_end == '\0') {
9150 struct variable *var, **vpp;
9152 vpp = get_ptr_to_local_var(name, name_end - name);
9153 var = vpp ? *vpp : NULL;
9155 if (exp == -1) { /* unexporting? */
9156 /* export -n NAME (without =VALUE) */
9158 var->flg_export = 0;
9159 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9161 } /* else: export -n NOT_EXISTING_VAR: no-op */
9164 if (exp == 1) { /* exporting? */
9165 /* export NAME (without =VALUE) */
9167 var->flg_export = 1;
9168 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9169 putenv(var->varstr);
9173 # if ENABLE_HUSH_LOCAL
9174 if (exp == 0 /* local? */
9175 && var && var->func_nest_level == lvl
9177 /* "local x=abc; ...; local x" - ignore second local decl */
9181 /* Exporting non-existing variable.
9182 * bash does not put it in environment,
9183 * but remembers that it is exported,
9184 * and does put it in env when it is set later.
9185 * We just set it to "" and export. */
9186 /* Or, it's "local NAME" (without =VALUE).
9187 * bash sets the value to "". */
9188 name = xasprintf("%s=", name);
9190 /* (Un)exporting/making local NAME=VALUE */
9191 name = xstrdup(name);
9193 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9198 #if ENABLE_HUSH_EXPORT
9199 static int FAST_FUNC builtin_export(char **argv)
9201 unsigned opt_unexport;
9203 #if ENABLE_HUSH_EXPORT_N
9204 /* "!": do not abort on errors */
9205 opt_unexport = getopt32(argv, "!n");
9206 if (opt_unexport == (uint32_t)-1)
9207 return EXIT_FAILURE;
9214 if (argv[0] == NULL) {
9221 /* ash emits: export VAR='VAL'
9222 * bash: declare -x VAR="VAL"
9223 * we follow ash example */
9224 const char *s = *e++;
9225 const char *p = strchr(s, '=');
9227 if (!p) /* wtf? take next variable */
9230 printf("export %.*s", (int)(p - s) + 1, s);
9231 print_escaped(p + 1);
9235 /*fflush_all(); - done after each builtin anyway */
9237 return EXIT_SUCCESS;
9240 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9242 return EXIT_SUCCESS;
9246 #if ENABLE_HUSH_LOCAL
9247 static int FAST_FUNC builtin_local(char **argv)
9249 if (G.func_nest_level == 0) {
9250 bb_error_msg("%s: not in a function", argv[0]);
9251 return EXIT_FAILURE; /* bash compat */
9253 helper_export_local(argv, 0, G.func_nest_level);
9254 return EXIT_SUCCESS;
9258 #if ENABLE_HUSH_UNSET
9259 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9260 static int FAST_FUNC builtin_unset(char **argv)
9265 /* "!": do not abort on errors */
9266 /* "+": stop at 1st non-option */
9267 opts = getopt32(argv, "!+vf");
9268 if (opts == (unsigned)-1)
9269 return EXIT_FAILURE;
9271 bb_error_msg("unset: -v and -f are exclusive");
9272 return EXIT_FAILURE;
9278 if (!(opts & 2)) { /* not -f */
9279 if (unset_local_var(*argv)) {
9280 /* unset <nonexistent_var> doesn't fail.
9281 * Error is when one tries to unset RO var.
9282 * Message was printed by unset_local_var. */
9286 # if ENABLE_HUSH_FUNCTIONS
9298 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9299 * built-in 'set' handler
9301 * set [-abCefhmnuvx] [-o option] [argument...]
9302 * set [+abCefhmnuvx] [+o option] [argument...]
9303 * set -- [argument...]
9306 * Implementations shall support the options in both their hyphen and
9307 * plus-sign forms. These options can also be specified as options to sh.
9309 * Write out all variables and their values: set
9310 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9311 * Turn on the -x and -v options: set -xv
9312 * Unset all positional parameters: set --
9313 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9314 * Set the positional parameters to the expansion of x, even if x expands
9315 * with a leading '-' or '+': set -- $x
9317 * So far, we only support "set -- [argument...]" and some of the short names.
9319 static int FAST_FUNC builtin_set(char **argv)
9322 char **pp, **g_argv;
9323 char *arg = *++argv;
9327 for (e = G.top_var; e; e = e->next)
9329 return EXIT_SUCCESS;
9333 if (strcmp(arg, "--") == 0) {
9337 if (arg[0] != '+' && arg[0] != '-')
9339 for (n = 1; arg[n]; ++n) {
9340 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9342 if (arg[n] == 'o' && argv[1])
9345 } while ((arg = *++argv) != NULL);
9346 /* Now argv[0] is 1st argument */
9349 return EXIT_SUCCESS;
9352 /* NB: G.global_argv[0] ($0) is never freed/changed */
9353 g_argv = G.global_argv;
9354 if (G.global_args_malloced) {
9360 G.global_args_malloced = 1;
9361 pp = xzalloc(sizeof(pp[0]) * 2);
9362 pp[0] = g_argv[0]; /* retain $0 */
9365 /* This realloc's G.global_argv */
9366 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9368 G.global_argc = 1 + string_array_len(pp + 1);
9370 return EXIT_SUCCESS;
9372 /* Nothing known, so abort */
9374 bb_error_msg("set: %s: invalid option", arg);
9375 return EXIT_FAILURE;
9379 static int FAST_FUNC builtin_shift(char **argv)
9382 argv = skip_dash_dash(argv);
9384 n = bb_strtou(argv[0], NULL, 10);
9385 if (errno || n < 0) {
9386 /* shared string with ash.c */
9387 bb_error_msg("Illegal number: %s", argv[0]);
9389 * ash aborts in this case.
9390 * bash prints error message and set $? to 1.
9391 * Interestingly, for "shift 99999" bash does not
9392 * print error message, but does set $? to 1
9393 * (and does no shifting at all).
9397 if (n >= 0 && n < G.global_argc) {
9398 if (G_global_args_malloced) {
9401 free(G.global_argv[m++]);
9404 memmove(&G.global_argv[1], &G.global_argv[n+1],
9405 G.global_argc * sizeof(G.global_argv[0]));
9406 return EXIT_SUCCESS;
9408 return EXIT_FAILURE;
9411 static int FAST_FUNC builtin_source(char **argv)
9413 char *arg_path, *filename;
9416 char *args_need_save;
9417 #if ENABLE_HUSH_FUNCTIONS
9421 argv = skip_dash_dash(argv);
9424 /* bash says: "bash: .: filename argument required" */
9425 return 2; /* bash compat */
9428 if (!strchr(filename, '/')) {
9429 arg_path = find_in_path(filename);
9431 filename = arg_path;
9433 input = remember_FILE(fopen_or_warn(filename, "r"));
9436 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9437 /* POSIX: non-interactive shell should abort here,
9438 * not merely fail. So far no one complained :)
9440 return EXIT_FAILURE;
9443 #if ENABLE_HUSH_FUNCTIONS
9444 sv_flg = G_flag_return_in_progress;
9445 /* "we are inside sourced file, ok to use return" */
9446 G_flag_return_in_progress = -1;
9448 args_need_save = argv[1]; /* used as a boolean variable */
9450 save_and_replace_G_args(&sv, argv);
9452 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9453 G.last_exitcode = 0;
9454 parse_and_run_file(input);
9455 fclose_and_forget(input);
9457 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9458 restore_G_args(&sv, argv);
9459 #if ENABLE_HUSH_FUNCTIONS
9460 G_flag_return_in_progress = sv_flg;
9463 return G.last_exitcode;
9466 #if ENABLE_HUSH_TRAP
9467 static int FAST_FUNC builtin_trap(char **argv)
9473 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9478 /* No args: print all trapped */
9479 for (i = 0; i < NSIG; ++i) {
9482 print_escaped(G_traps[i]);
9483 /* note: bash adds "SIG", but only if invoked
9484 * as "bash". If called as "sh", or if set -o posix,
9485 * then it prints short signal names.
9486 * We are printing short names: */
9487 printf(" %s\n", get_signame(i));
9490 /*fflush_all(); - done after each builtin anyway */
9491 return EXIT_SUCCESS;
9495 /* If first arg is a number: reset all specified signals */
9496 sig = bb_strtou(*argv, NULL, 10);
9502 sighandler_t handler;
9504 sig = get_signum(*argv++);
9505 if (sig < 0 || sig >= NSIG) {
9507 /* Mimic bash message exactly */
9508 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9513 G_traps[sig] = xstrdup(new_cmd);
9515 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9516 get_signame(sig), sig, G_traps[sig]);
9518 /* There is no signal for 0 (EXIT) */
9523 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9525 /* We are removing trap handler */
9526 handler = pick_sighandler(sig);
9527 install_sighandler(sig, handler);
9532 if (!argv[1]) { /* no second arg */
9533 bb_error_msg("trap: invalid arguments");
9534 return EXIT_FAILURE;
9537 /* First arg is "-": reset all specified to default */
9538 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9539 /* Everything else: set arg as signal handler
9540 * (includes "" case, which ignores signal) */
9541 if (argv[0][0] == '-') {
9542 if (argv[0][1] == '\0') { /* "-" */
9543 /* new_cmd remains NULL: "reset these sigs" */
9546 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9549 /* else: "-something", no special meaning */
9554 goto process_sig_list;
9559 static struct pipe *parse_jobspec(const char *str)
9564 if (sscanf(str, "%%%u", &jobnum) != 1) {
9566 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9568 bb_error_msg("bad argument '%s'", str);
9571 /* It is "%%", "%+" or "%" - current job */
9572 jobnum = G.last_jobid;
9574 bb_error_msg("no current job");
9578 for (pi = G.job_list; pi; pi = pi->next) {
9579 if (pi->jobid == jobnum) {
9583 bb_error_msg("%u: no such job", jobnum);
9587 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9590 const char *status_string;
9592 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9593 for (job = G.job_list; job; job = job->next) {
9594 if (job->alive_cmds == job->stopped_cmds)
9595 status_string = "Stopped";
9597 status_string = "Running";
9599 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9601 return EXIT_SUCCESS;
9604 /* built-in 'fg' and 'bg' handler */
9605 static int FAST_FUNC builtin_fg_bg(char **argv)
9610 if (!G_interactive_fd)
9611 return EXIT_FAILURE;
9613 /* If they gave us no args, assume they want the last backgrounded task */
9615 for (pi = G.job_list; pi; pi = pi->next) {
9616 if (pi->jobid == G.last_jobid) {
9620 bb_error_msg("%s: no current job", argv[0]);
9621 return EXIT_FAILURE;
9624 pi = parse_jobspec(argv[1]);
9626 return EXIT_FAILURE;
9628 /* TODO: bash prints a string representation
9629 * of job being foregrounded (like "sleep 1 | cat") */
9630 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9631 /* Put the job into the foreground. */
9632 tcsetpgrp(G_interactive_fd, pi->pgrp);
9635 /* Restart the processes in the job */
9636 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9637 for (i = 0; i < pi->num_cmds; i++) {
9638 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9640 pi->stopped_cmds = 0;
9642 i = kill(- pi->pgrp, SIGCONT);
9644 if (errno == ESRCH) {
9645 delete_finished_bg_job(pi);
9646 return EXIT_SUCCESS;
9648 bb_perror_msg("kill (SIGCONT)");
9651 if (argv[0][0] == 'f') {
9653 return checkjobs_and_fg_shell(pi);
9655 return EXIT_SUCCESS;
9659 #if ENABLE_HUSH_KILL
9660 static int FAST_FUNC builtin_kill(char **argv)
9664 # if ENABLE_HUSH_JOB
9665 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9673 if (argv[i][0] != '%')
9676 * "kill %N" - job kill
9677 * Converting to pgrp / pid kill
9679 pi = parse_jobspec(argv[i]);
9681 /* Eat bad jobspec */
9685 argv[j - 1] = argv[j];
9692 * In jobs started under job control, we signal
9693 * entire process group by kill -PGRP_ID.
9694 * This happens, f.e., in interactive shell.
9696 * Otherwise, we signal each child via
9697 * kill PID1 PID2 PID3.
9699 * sh -c 'sleep 1|sleep 1 & kill %1'
9700 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9701 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9703 n = G_interactive_fd ? 1 : pi->num_cmds;
9704 dst = alloca(n * sizeof(int)*4);
9706 if (G_interactive_fd)
9707 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9708 else for (j = 0; j < n; j++) {
9709 struct command *cmd = &pi->cmds[j];
9710 /* Skip exited members of the job */
9714 * kill_main has matching code to expect
9715 * leading space. Needed to not confuse
9716 * negative pids with "kill -SIGNAL_NO" syntax
9718 dst += sprintf(dst, " %u", (int)cmd->pid);
9721 } while (argv[++i]);
9725 if (argv[1] || ret == 0) {
9726 ret = run_applet_main(argv, kill_main);
9728 /* else: ret = 1, "kill %bad_jobspec" case */
9733 #if ENABLE_HUSH_WAIT
9734 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9735 #if !ENABLE_HUSH_JOB
9736 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9738 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9745 if (!sigisemptyset(&G.pending_set))
9748 /* waitpid is not interruptible by SA_RESTARTed
9749 * signals which we use. Thus, this ugly dance:
9752 /* Make sure possible SIGCHLD is stored in kernel's
9753 * pending signal mask before we call waitpid.
9754 * Or else we may race with SIGCHLD, lose it,
9755 * and get stuck in sigsuspend...
9757 sigfillset(&oldset); /* block all signals, remember old set */
9758 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9760 if (!sigisemptyset(&G.pending_set)) {
9761 /* Crap! we raced with some signal! */
9765 /*errno = 0; - checkjobs does this */
9766 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9767 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9768 debug_printf_exec("checkjobs:%d\n", ret);
9771 int rcode = job_exited_or_stopped(waitfor_pipe);
9772 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9775 sigprocmask(SIG_SETMASK, &oldset, NULL);
9780 /* if ECHILD, there are no children (ret is -1 or 0) */
9781 /* if ret == 0, no children changed state */
9782 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9783 if (errno == ECHILD || ret) {
9785 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9787 sigprocmask(SIG_SETMASK, &oldset, NULL);
9790 /* Wait for SIGCHLD or any other signal */
9791 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9792 /* Note: sigsuspend invokes signal handler */
9793 sigsuspend(&oldset);
9795 sigprocmask(SIG_SETMASK, &oldset, NULL);
9797 /* So, did we get a signal? */
9798 sig = check_and_run_traps();
9799 if (sig /*&& sig != SIGCHLD - always true */) {
9803 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9808 static int FAST_FUNC builtin_wait(char **argv)
9813 argv = skip_dash_dash(argv);
9814 if (argv[0] == NULL) {
9815 /* Don't care about wait results */
9816 /* Note 1: must wait until there are no more children */
9817 /* Note 2: must be interruptible */
9819 * $ sleep 3 & sleep 6 & wait
9824 * $ sleep 3 & sleep 6 & wait
9828 * ^C <-- after ~4 sec from keyboard
9831 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9835 pid_t pid = bb_strtou(*argv, NULL, 10);
9836 if (errno || pid <= 0) {
9838 if (argv[0][0] == '%') {
9839 struct pipe *wait_pipe;
9840 ret = 127; /* bash compat for bad jobspecs */
9841 wait_pipe = parse_jobspec(*argv);
9843 ret = job_exited_or_stopped(wait_pipe);
9845 ret = wait_for_child_or_signal(wait_pipe, 0);
9847 /* else: parse_jobspec() already emitted error msg */
9851 /* mimic bash message */
9852 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9854 continue; /* bash checks all argv[] */
9857 /* Do we have such child? */
9858 ret = waitpid(pid, &status, WNOHANG);
9861 if (errno == ECHILD) {
9862 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9863 /* "wait $!" but last bg task has already exited. Try:
9864 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9865 * In bash it prints exitcode 0, then 3.
9866 * In dash, it is 127.
9868 /* ret = G.last_bg_pid_exitstatus - FIXME */
9870 /* Example: "wait 1". mimic bash message */
9871 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9875 bb_perror_msg("wait %s", *argv);
9878 continue; /* bash checks all argv[] */
9881 /* Yes, and it still runs */
9882 ret = wait_for_child_or_signal(NULL, pid);
9884 /* Yes, and it just exited */
9885 process_wait_result(NULL, pid, status);
9886 ret = WEXITSTATUS(status);
9887 if (WIFSIGNALED(status))
9888 ret = 128 + WTERMSIG(status);
9896 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9897 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9900 def = bb_strtou(argv[1], NULL, 10);
9901 if (errno || def < def_min || argv[2]) {
9902 bb_error_msg("%s: bad arguments", argv[0]);
9910 #if ENABLE_HUSH_LOOPS
9911 static int FAST_FUNC builtin_break(char **argv)
9914 if (G.depth_of_loop == 0) {
9915 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9916 /* if we came from builtin_continue(), need to undo "= 1" */
9917 G.flag_break_continue = 0;
9918 return EXIT_SUCCESS; /* bash compat */
9920 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9922 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9923 if (depth == UINT_MAX)
9924 G.flag_break_continue = BC_BREAK;
9925 if (G.depth_of_loop < depth)
9926 G.depth_break_continue = G.depth_of_loop;
9928 return EXIT_SUCCESS;
9931 static int FAST_FUNC builtin_continue(char **argv)
9933 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9934 return builtin_break(argv);
9938 #if ENABLE_HUSH_FUNCTIONS
9939 static int FAST_FUNC builtin_return(char **argv)
9943 if (G_flag_return_in_progress != -1) {
9944 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9945 return EXIT_FAILURE; /* bash compat */
9948 G_flag_return_in_progress = 1;
9951 * out of range: wraps around at 256, does not error out
9952 * non-numeric param:
9953 * f() { false; return qwe; }; f; echo $?
9954 * bash: return: qwe: numeric argument required <== we do this
9955 * 255 <== we also do this
9957 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
9962 #if ENABLE_HUSH_MEMLEAK
9963 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9968 # ifdef M_TRIM_THRESHOLD
9969 /* Optional. Reduces probability of false positives */
9972 /* Crude attempt to find where "free memory" starts,
9973 * sans fragmentation. */
9975 l = (unsigned long)p;
9978 if (l < (unsigned long)p) l = (unsigned long)p;
9984 struct mallinfo mi = mallinfo();
9985 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9986 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9990 if (!G.memleak_value)
9991 G.memleak_value = l;
9993 l -= G.memleak_value;
10000 /* Exitcode is "how many kilobytes we leaked since 1st call" */