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)
1483 sv->sv_argv0 = argv[0];
1484 sv->sv_g_argv = G.global_argv;
1485 sv->sv_g_argc = G.global_argc;
1486 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1488 argv[0] = G.global_argv[0]; /* retain $0 */
1489 G.global_argv = argv;
1490 IF_HUSH_SET(G.global_args_malloced = 0;)
1498 static void restore_G_args(save_arg_t *sv, char **argv)
1501 if (G.global_args_malloced) {
1502 /* someone ran "set -- arg1 arg2 ...", undo */
1503 char **pp = G.global_argv;
1504 while (*++pp) /* note: does not free $0 */
1506 free(G.global_argv);
1509 argv[0] = sv->sv_argv0;
1510 G.global_argv = sv->sv_g_argv;
1511 G.global_argc = sv->sv_g_argc;
1512 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1516 /* Basic theory of signal handling in shell
1517 * ========================================
1518 * This does not describe what hush does, rather, it is current understanding
1519 * what it _should_ do. If it doesn't, it's a bug.
1520 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1522 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1523 * is finished or backgrounded. It is the same in interactive and
1524 * non-interactive shells, and is the same regardless of whether
1525 * a user trap handler is installed or a shell special one is in effect.
1526 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1527 * backgrounds (i.e. stops) or kills all members of currently running
1530 * Wait builtin is interruptible by signals for which user trap is set
1531 * or by SIGINT in interactive shell.
1533 * Trap handlers will execute even within trap handlers. (right?)
1535 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1536 * except for handlers set to '' (empty string).
1538 * If job control is off, backgrounded commands ("cmd &")
1539 * have SIGINT, SIGQUIT set to SIG_IGN.
1541 * Commands which are run in command substitution ("`cmd`")
1542 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1544 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1545 * by the shell from its parent.
1547 * Signals which differ from SIG_DFL action
1548 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1551 * SIGTERM (interactive): ignore
1552 * SIGHUP (interactive):
1553 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1554 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1555 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1556 * that all pipe members are stopped. Try this in bash:
1557 * while :; do :; done - ^Z does not background it
1558 * (while :; do :; done) - ^Z backgrounds it
1559 * SIGINT (interactive): wait for last pipe, ignore the rest
1560 * of the command line, show prompt. NB: ^C does not send SIGINT
1561 * to interactive shell while shell is waiting for a pipe,
1562 * since shell is bg'ed (is not in foreground process group).
1563 * Example 1: this waits 5 sec, but does not execute ls:
1564 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1565 * Example 2: this does not wait and does not execute ls:
1566 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1567 * Example 3: this does not wait 5 sec, but executes ls:
1568 * "sleep 5; ls -l" + press ^C
1569 * Example 4: this does not wait and does not execute ls:
1570 * "sleep 5 & wait; ls -l" + press ^C
1572 * (What happens to signals which are IGN on shell start?)
1573 * (What happens with signal mask on shell start?)
1575 * Old implementation
1576 * ==================
1577 * We use in-kernel pending signal mask to determine which signals were sent.
1578 * We block all signals which we don't want to take action immediately,
1579 * i.e. we block all signals which need to have special handling as described
1580 * above, and all signals which have traps set.
1581 * After each pipe execution, we extract any pending signals via sigtimedwait()
1584 * unsigned special_sig_mask: a mask of such "special" signals
1585 * sigset_t blocked_set: current blocked signal set
1588 * clear bit in blocked_set unless it is also in special_sig_mask
1589 * "trap 'cmd' SIGxxx":
1590 * set bit in blocked_set (even if 'cmd' is '')
1591 * after [v]fork, if we plan to be a shell:
1592 * unblock signals with special interactive handling
1593 * (child shell is not interactive),
1594 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1595 * after [v]fork, if we plan to exec:
1596 * POSIX says fork clears pending signal mask in child - no need to clear it.
1597 * Restore blocked signal set to one inherited by shell just prior to exec.
1599 * Note: as a result, we do not use signal handlers much. The only uses
1600 * are to count SIGCHLDs
1601 * and to restore tty pgrp on signal-induced exit.
1604 * Standard says "When a subshell is entered, traps that are not being ignored
1605 * are set to the default actions". bash interprets it so that traps which
1606 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1608 * Problem: the above approach makes it unwieldy to catch signals while
1609 * we are in read builtin, or while we read commands from stdin:
1610 * masked signals are not visible!
1612 * New implementation
1613 * ==================
1614 * We record each signal we are interested in by installing signal handler
1615 * for them - a bit like emulating kernel pending signal mask in userspace.
1616 * We are interested in: signals which need to have special handling
1617 * as described above, and all signals which have traps set.
1618 * Signals are recorded in pending_set.
1619 * After each pipe execution, we extract any pending signals
1622 * unsigned special_sig_mask: a mask of shell-special signals.
1623 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1624 * char *traps[sig] if trap for sig is set (even if it's '').
1625 * sigset_t pending_set: set of sigs we received.
1628 * if sig is in special_sig_mask, set handler back to:
1629 * record_pending_signo, or to IGN if it's a tty stop signal
1630 * if sig is in fatal_sig_mask, set handler back to sigexit.
1631 * else: set handler back to SIG_DFL
1632 * "trap 'cmd' SIGxxx":
1633 * set handler to record_pending_signo.
1635 * set handler to SIG_IGN.
1636 * after [v]fork, if we plan to be a shell:
1637 * set signals with special interactive handling to SIG_DFL
1638 * (because child shell is not interactive),
1639 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1640 * after [v]fork, if we plan to exec:
1641 * POSIX says fork clears pending signal mask in child - no need to clear it.
1643 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1644 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1647 * Standard says "When a subshell is entered, traps that are not being ignored
1648 * are set to the default actions". bash interprets it so that traps which
1649 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1652 SPECIAL_INTERACTIVE_SIGS = 0
1657 SPECIAL_JOBSTOP_SIGS = 0
1666 static void record_pending_signo(int sig)
1668 sigaddset(&G.pending_set, sig);
1669 #if ENABLE_HUSH_FAST
1670 if (sig == SIGCHLD) {
1672 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1677 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1679 struct sigaction old_sa;
1681 /* We could use signal() to install handlers... almost:
1682 * except that we need to mask ALL signals while handlers run.
1683 * I saw signal nesting in strace, race window isn't small.
1684 * SA_RESTART is also needed, but in Linux, signal()
1685 * sets SA_RESTART too.
1687 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1688 /* sigfillset(&G.sa.sa_mask); - already done */
1689 /* G.sa.sa_flags = SA_RESTART; - already done */
1690 G.sa.sa_handler = handler;
1691 sigaction(sig, &G.sa, &old_sa);
1692 return old_sa.sa_handler;
1695 static void hush_exit(int exitcode) NORETURN;
1697 static void restore_ttypgrp_and__exit(void) NORETURN;
1698 static void restore_ttypgrp_and__exit(void)
1700 /* xfunc has failed! die die die */
1701 /* no EXIT traps, this is an escape hatch! */
1703 hush_exit(xfunc_error_retval);
1708 /* Needed only on some libc:
1709 * It was observed that on exit(), fgetc'ed buffered data
1710 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1711 * With the net effect that even after fork(), not vfork(),
1712 * exit() in NOEXECed applet in "sh SCRIPT":
1713 * noexec_applet_here
1714 * echo END_OF_SCRIPT
1715 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1716 * This makes "echo END_OF_SCRIPT" executed twice.
1717 * Similar problems can be seen with die_if_script() -> xfunc_die()
1718 * and in `cmd` handling.
1719 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1721 static void fflush_and__exit(void) NORETURN;
1722 static void fflush_and__exit(void)
1725 _exit(xfunc_error_retval);
1728 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1729 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1730 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1731 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1733 /* Restores tty foreground process group, and exits.
1734 * May be called as signal handler for fatal signal
1735 * (will resend signal to itself, producing correct exit state)
1736 * or called directly with -EXITCODE.
1737 * We also call it if xfunc is exiting.
1739 static void sigexit(int sig) NORETURN;
1740 static void sigexit(int sig)
1742 /* Careful: we can end up here after [v]fork. Do not restore
1743 * tty pgrp then, only top-level shell process does that */
1744 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1745 /* Disable all signals: job control, SIGPIPE, etc.
1746 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1748 sigprocmask_allsigs(SIG_BLOCK);
1749 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1752 /* Not a signal, just exit */
1756 kill_myself_with_sig(sig); /* does not return */
1760 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1761 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1765 static sighandler_t pick_sighandler(unsigned sig)
1767 sighandler_t handler = SIG_DFL;
1768 if (sig < sizeof(unsigned)*8) {
1769 unsigned sigmask = (1 << sig);
1773 if (G_fatal_sig_mask & sigmask)
1777 /* sig has special handling? */
1778 if (G.special_sig_mask & sigmask) {
1779 handler = record_pending_signo;
1780 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1781 * in order to ignore them: they will be raised
1782 * in an endless loop when we try to do some
1783 * terminal ioctls! We do have to _ignore_ these.
1785 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1792 /* Restores tty foreground process group, and exits. */
1793 static void hush_exit(int exitcode)
1795 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1796 save_history(G.line_input_state);
1800 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1802 /* argv[0] is unused */
1803 argv[1] = G_traps[0];
1805 G.exiting = 1; /* prevent EXIT trap recursion */
1806 /* Note: G_traps[0] is not cleared!
1807 * "trap" will still show it, if executed
1812 #if ENABLE_FEATURE_CLEAN_UP
1814 struct variable *cur_var;
1815 if (G.cwd != bb_msg_unknown)
1817 cur_var = G.top_var;
1819 struct variable *tmp = cur_var;
1820 if (!cur_var->max_len)
1821 free(cur_var->varstr);
1822 cur_var = cur_var->next;
1830 sigexit(- (exitcode & 0xff));
1837 //TODO: return a mask of ALL handled sigs?
1838 static int check_and_run_traps(void)
1845 if (sigisemptyset(&G.pending_set))
1850 if (sigismember(&G.pending_set, sig)) {
1851 sigdelset(&G.pending_set, sig);
1854 } while (sig < NSIG);
1857 if (G_traps && G_traps[sig]) {
1858 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1859 if (G_traps[sig][0]) {
1860 /* We have user-defined handler */
1861 smalluint save_rcode;
1863 /* argv[0] is unused */
1864 argv[1] = G_traps[sig];
1866 save_rcode = G.last_exitcode;
1868 //FIXME: shouldn't it be set to 128 + sig instead?
1869 G.last_exitcode = save_rcode;
1871 } /* else: "" trap, ignoring signal */
1874 /* not a trap: special action */
1877 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1884 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1885 /* bash is observed to signal whole process groups,
1886 * not individual processes */
1887 for (job = G.job_list; job; job = job->next) {
1890 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1891 if (kill(- job->pgrp, SIGHUP) == 0)
1892 kill(- job->pgrp, SIGCONT);
1897 #if ENABLE_HUSH_FAST
1899 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1901 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1903 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1904 * This simplifies wait builtin a bit.
1908 default: /* ignored: */
1909 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1910 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1912 * We don't do 'last_sig = sig' here -> NOT returning this sig.
1913 * Example: wait is not interrupted by TERM
1914 * in interactive shell, because TERM is ignored.
1923 static const char *get_cwd(int force)
1925 if (force || G.cwd == NULL) {
1926 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1927 * we must not try to free(bb_msg_unknown) */
1928 if (G.cwd == bb_msg_unknown)
1930 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1932 G.cwd = bb_msg_unknown;
1939 * Shell and environment variable support
1941 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1943 struct variable **pp;
1944 struct variable *cur;
1947 while ((cur = *pp) != NULL) {
1948 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1955 static const char* FAST_FUNC get_local_var_value(const char *name)
1957 struct variable **vpp;
1958 unsigned len = strlen(name);
1960 if (G.expanded_assignments) {
1961 char **cpp = G.expanded_assignments;
1964 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1965 return cp + len + 1;
1970 vpp = get_ptr_to_local_var(name, len);
1972 return (*vpp)->varstr + len + 1;
1974 if (strcmp(name, "PPID") == 0)
1975 return utoa(G.root_ppid);
1976 // bash compat: UID? EUID?
1977 #if ENABLE_HUSH_RANDOM_SUPPORT
1978 if (strcmp(name, "RANDOM") == 0)
1979 return utoa(next_random(&G.random_gen));
1984 /* str holds "NAME=VAL" and is expected to be malloced.
1985 * We take ownership of it.
1987 * 0: do not change export flag
1988 * (if creating new variable, flag will be 0)
1989 * 1: set export flag and putenv the variable
1990 * -1: clear export flag and unsetenv the variable
1991 * flg_read_only is set only when we handle -R var=val
1993 #if !BB_MMU && ENABLE_HUSH_LOCAL
1994 /* all params are used */
1995 #elif BB_MMU && ENABLE_HUSH_LOCAL
1996 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1997 set_local_var(str, flg_export, local_lvl)
1998 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1999 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2000 set_local_var(str, flg_export)
2001 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2002 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2003 set_local_var(str, flg_export, flg_read_only)
2005 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2007 struct variable **var_pp;
2008 struct variable *cur;
2009 char *free_me = NULL;
2013 eq_sign = strchr(str, '=');
2014 if (!eq_sign) { /* not expected to ever happen? */
2019 name_len = eq_sign - str + 1; /* including '=' */
2020 var_pp = &G.top_var;
2021 while ((cur = *var_pp) != NULL) {
2022 if (strncmp(cur->varstr, str, name_len) != 0) {
2023 var_pp = &cur->next;
2027 /* We found an existing var with this name */
2028 if (cur->flg_read_only) {
2032 bb_error_msg("%s: readonly variable", str);
2036 if (flg_export == -1) { // "&& cur->flg_export" ?
2037 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2042 #if ENABLE_HUSH_LOCAL
2043 if (cur->func_nest_level < local_lvl) {
2044 /* New variable is declared as local,
2045 * and existing one is global, or local
2046 * from enclosing function.
2047 * Remove and save old one: */
2048 *var_pp = cur->next;
2049 cur->next = *G.shadowed_vars_pp;
2050 *G.shadowed_vars_pp = cur;
2051 /* bash 3.2.33(1) and exported vars:
2053 * # f() { local z=a; env | grep ^z; }
2059 if (cur->flg_export)
2064 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2069 if (cur->max_len != 0) {
2070 if (cur->max_len >= strlen(str)) {
2071 /* This one is from startup env, reuse space */
2072 strcpy(cur->varstr, str);
2077 goto set_str_and_exp;
2079 /* max_len == 0 signifies "malloced" var, which we can
2080 * (and have to) free. But we can't free(cur->varstr) here:
2081 * if cur->flg_export is 1, it is in the environment.
2082 * We should either unsetenv+free, or wait until putenv,
2083 * then putenv(new)+free(old).
2085 free_me = cur->varstr;
2086 goto set_str_and_exp;
2089 /* Not found - create new variable struct */
2090 cur = xzalloc(sizeof(*cur));
2091 #if ENABLE_HUSH_LOCAL
2092 cur->func_nest_level = local_lvl;
2094 cur->next = *var_pp;
2100 cur->flg_read_only = flg_read_only;
2103 if (flg_export == 1)
2104 cur->flg_export = 1;
2105 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2106 cmdedit_update_prompt();
2107 if (cur->flg_export) {
2108 if (flg_export == -1) {
2109 cur->flg_export = 0;
2110 /* unsetenv was already done */
2113 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2114 i = putenv(cur->varstr);
2115 /* only now we can free old exported malloced string */
2124 /* Used at startup and after each cd */
2125 static void set_pwd_var(int exp)
2127 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2128 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2131 static int unset_local_var_len(const char *name, int name_len)
2133 struct variable *cur;
2134 struct variable **var_pp;
2137 return EXIT_SUCCESS;
2138 var_pp = &G.top_var;
2139 while ((cur = *var_pp) != NULL) {
2140 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2141 if (cur->flg_read_only) {
2142 bb_error_msg("%s: readonly variable", name);
2143 return EXIT_FAILURE;
2145 *var_pp = cur->next;
2146 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2147 bb_unsetenv(cur->varstr);
2148 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2149 cmdedit_update_prompt();
2153 return EXIT_SUCCESS;
2155 var_pp = &cur->next;
2157 return EXIT_SUCCESS;
2160 #if ENABLE_HUSH_UNSET
2161 static int unset_local_var(const char *name)
2163 return unset_local_var_len(name, strlen(name));
2167 static void unset_vars(char **strings)
2175 const char *eq = strchrnul(*v, '=');
2176 unset_local_var_len(*v, (int)(eq - *v));
2182 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2183 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2185 char *var = xasprintf("%s=%s", name, val);
2186 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2192 * Helpers for "var1=val1 var2=val2 cmd" feature
2194 static void add_vars(struct variable *var)
2196 struct variable *next;
2200 var->next = G.top_var;
2202 if (var->flg_export) {
2203 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2204 putenv(var->varstr);
2206 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2212 static struct variable *set_vars_and_save_old(char **strings)
2215 struct variable *old = NULL;
2221 struct variable *var_p;
2222 struct variable **var_pp;
2225 eq = strchr(*s, '=');
2227 var_pp = get_ptr_to_local_var(*s, eq - *s);
2229 /* Remove variable from global linked list */
2231 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2232 *var_pp = var_p->next;
2233 /* Add it to returned list */
2237 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2248 static void reinit_unicode_for_hush(void)
2250 /* Unicode support should be activated even if LANG is set
2251 * _during_ shell execution, not only if it was set when
2252 * shell was started. Therefore, re-check LANG every time:
2254 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2255 || ENABLE_UNICODE_USING_LOCALE
2257 const char *s = get_local_var_value("LC_ALL");
2258 if (!s) s = get_local_var_value("LC_CTYPE");
2259 if (!s) s = get_local_var_value("LANG");
2265 * in_str support (strings, and "strings" read from files).
2268 #if ENABLE_HUSH_INTERACTIVE
2269 /* To test correct lineedit/interactive behavior, type from command line:
2275 * It exercises a lot of corner cases.
2277 static void cmdedit_update_prompt(void)
2279 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2280 G.PS1 = get_local_var_value("PS1");
2283 G.PS2 = get_local_var_value("PS2");
2290 static const char *setup_prompt_string(int promptmode)
2292 const char *prompt_str;
2293 debug_printf("setup_prompt_string %d ", promptmode);
2294 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2295 /* Set up the prompt */
2296 if (promptmode == 0) { /* PS1 */
2298 /* bash uses $PWD value, even if it is set by user.
2299 * It uses current dir only if PWD is unset.
2300 * We always use current dir. */
2301 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2306 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2307 debug_printf("prompt_str '%s'\n", prompt_str);
2310 static int get_user_input(struct in_str *i)
2313 const char *prompt_str;
2315 prompt_str = setup_prompt_string(i->promptmode);
2316 # if ENABLE_FEATURE_EDITING
2318 reinit_unicode_for_hush();
2319 if (G.flag_SIGINT) {
2320 /* There was ^C'ed, make it look prettier: */
2324 /* buglet: SIGINT will not make new prompt to appear _at once_,
2325 * only after <Enter>. (^C works immediately) */
2326 r = read_line_input(G.line_input_state, prompt_str,
2327 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2330 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2332 write(STDOUT_FILENO, "^C", 2);
2335 check_and_run_traps();
2336 if (r != 0 && !G.flag_SIGINT)
2338 /* ^C or SIGINT: repeat */
2339 G.last_exitcode = 128 + SIGINT;
2342 /* EOF/error detected */
2344 i->peek_buf[0] = r = EOF;
2347 i->p = G.user_input_buf;
2348 return (unsigned char)*i->p++;
2352 if (i->last_char == '\0' || i->last_char == '\n') {
2353 /* Why check_and_run_traps here? Try this interactively:
2354 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2355 * $ <[enter], repeatedly...>
2356 * Without check_and_run_traps, handler never runs.
2358 check_and_run_traps();
2359 fputs(prompt_str, stdout);
2362 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2364 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2365 * no ^C masking happens during fgetc, no special code for ^C:
2366 * it generates SIGINT as usual.
2368 check_and_run_traps();
2370 G.last_exitcode = 128 + SIGINT;
2377 /* This is the magic location that prints prompts
2378 * and gets data back from the user */
2379 static int fgetc_interactive(struct in_str *i)
2382 /* If it's interactive stdin, get new line. */
2383 if (G_interactive_fd && i->file == stdin) {
2384 /* Returns first char (or EOF), the rest is in i->p[] */
2385 ch = get_user_input(i);
2386 i->promptmode = 1; /* PS2 */
2388 /* Not stdin: script file, sourced file, etc */
2389 do ch = fgetc(i->file); while (ch == '\0');
2394 static inline int fgetc_interactive(struct in_str *i)
2397 do ch = fgetc(i->file); while (ch == '\0');
2400 #endif /* INTERACTIVE */
2402 static int i_getch(struct in_str *i)
2407 /* string-based in_str */
2408 ch = (unsigned char)*i->p;
2417 /* FILE-based in_str */
2419 #if ENABLE_FEATURE_EDITING
2420 /* This can be stdin, check line editing char[] buffer */
2421 if (i->p && *i->p != '\0') {
2422 ch = (unsigned char)*i->p++;
2426 /* peek_buf[] is an int array, not char. Can contain EOF. */
2427 ch = i->peek_buf[0];
2429 int ch2 = i->peek_buf[1];
2430 i->peek_buf[0] = ch2;
2431 if (ch2 == 0) /* very likely, avoid redundant write */
2437 ch = fgetc_interactive(i);
2439 debug_printf("file_get: got '%c' %d\n", ch, ch);
2444 static int i_peek(struct in_str *i)
2449 /* string-based in_str */
2450 /* Doesn't report EOF on NUL. None of the callers care. */
2451 return (unsigned char)*i->p;
2454 /* FILE-based in_str */
2456 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2457 /* This can be stdin, check line editing char[] buffer */
2458 if (i->p && *i->p != '\0')
2459 return (unsigned char)*i->p;
2461 /* peek_buf[] is an int array, not char. Can contain EOF. */
2462 ch = i->peek_buf[0];
2466 /* Need to get a new char */
2467 ch = fgetc_interactive(i);
2468 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2470 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2471 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2477 i->peek_buf[0] = ch;
2478 /*i->peek_buf[1] = 0; - already is */
2482 /* Only ever called if i_peek() was called, and did not return EOF.
2483 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2484 * not end-of-line. Therefore we never need to read a new editing line here.
2486 static int i_peek2(struct in_str *i)
2490 /* There are two cases when i->p[] buffer exists.
2491 * (1) it's a string in_str.
2492 * (2) It's a file, and we have a saved line editing buffer.
2493 * In both cases, we know that i->p[0] exists and not NUL, and
2494 * the peek2 result is in i->p[1].
2497 return (unsigned char)i->p[1];
2499 /* Now we know it is a file-based in_str. */
2501 /* peek_buf[] is an int array, not char. Can contain EOF. */
2502 /* Is there 2nd char? */
2503 ch = i->peek_buf[1];
2505 /* We did not read it yet, get it now */
2506 do ch = fgetc(i->file); while (ch == '\0');
2507 i->peek_buf[1] = ch;
2510 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2514 static void setup_file_in_str(struct in_str *i, FILE *f)
2516 memset(i, 0, sizeof(*i));
2517 /* i->promptmode = 0; - PS1 (memset did it) */
2522 static void setup_string_in_str(struct in_str *i, const char *s)
2524 memset(i, 0, sizeof(*i));
2525 /* i->promptmode = 0; - PS1 (memset did it) */
2526 /*i->file = NULL */;
2534 #define B_CHUNK (32 * sizeof(char*))
2536 static void o_reset_to_empty_unquoted(o_string *o)
2539 o->has_quoted_part = 0;
2544 static void o_free(o_string *o)
2547 memset(o, 0, sizeof(*o));
2550 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2555 static void o_grow_by(o_string *o, int len)
2557 if (o->length + len > o->maxlen) {
2558 o->maxlen += (2 * len) | (B_CHUNK-1);
2559 o->data = xrealloc(o->data, 1 + o->maxlen);
2563 static void o_addchr(o_string *o, int ch)
2565 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2566 if (o->length < o->maxlen) {
2567 /* likely. avoid o_grow_by() call */
2569 o->data[o->length] = ch;
2571 o->data[o->length] = '\0';
2579 /* Valid only if we know o_string is not empty */
2580 static void o_delchr(o_string *o)
2583 o->data[o->length] = '\0';
2587 static void o_addblock(o_string *o, const char *str, int len)
2590 memcpy(&o->data[o->length], str, len);
2592 o->data[o->length] = '\0';
2595 static void o_addstr(o_string *o, const char *str)
2597 o_addblock(o, str, strlen(str));
2601 static void nommu_addchr(o_string *o, int ch)
2607 # define nommu_addchr(o, str) ((void)0)
2610 static void o_addstr_with_NUL(o_string *o, const char *str)
2612 o_addblock(o, str, strlen(str) + 1);
2616 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2617 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2618 * Apparently, on unquoted $v bash still does globbing
2619 * ("v='*.txt'; echo $v" prints all .txt files),
2620 * but NOT brace expansion! Thus, there should be TWO independent
2621 * quoting mechanisms on $v expansion side: one protects
2622 * $v from brace expansion, and other additionally protects "$v" against globbing.
2623 * We have only second one.
2626 #if ENABLE_HUSH_BRACE_EXPANSION
2627 # define MAYBE_BRACES "{}"
2629 # define MAYBE_BRACES ""
2632 /* My analysis of quoting semantics tells me that state information
2633 * is associated with a destination, not a source.
2635 static void o_addqchr(o_string *o, int ch)
2638 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2643 o->data[o->length] = '\\';
2646 o->data[o->length] = ch;
2648 o->data[o->length] = '\0';
2651 static void o_addQchr(o_string *o, int ch)
2654 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2655 && strchr("*?[\\" MAYBE_BRACES, ch)
2658 o->data[o->length] = '\\';
2662 o->data[o->length] = ch;
2664 o->data[o->length] = '\0';
2667 static void o_addqblock(o_string *o, const char *str, int len)
2672 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2673 if (ordinary_cnt > len) /* paranoia */
2675 o_addblock(o, str, ordinary_cnt);
2676 if (ordinary_cnt == len)
2677 return; /* NUL is already added by o_addblock */
2678 str += ordinary_cnt;
2679 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2683 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2685 o->data[o->length] = '\\';
2689 o->data[o->length] = ch;
2692 o->data[o->length] = '\0';
2695 static void o_addQblock(o_string *o, const char *str, int len)
2697 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2698 o_addblock(o, str, len);
2701 o_addqblock(o, str, len);
2704 static void o_addQstr(o_string *o, const char *str)
2706 o_addQblock(o, str, strlen(str));
2709 /* A special kind of o_string for $VAR and `cmd` expansion.
2710 * It contains char* list[] at the beginning, which is grown in 16 element
2711 * increments. Actual string data starts at the next multiple of 16 * (char*).
2712 * list[i] contains an INDEX (int!) into this string data.
2713 * It means that if list[] needs to grow, data needs to be moved higher up
2714 * but list[i]'s need not be modified.
2715 * NB: remembering how many list[i]'s you have there is crucial.
2716 * o_finalize_list() operation post-processes this structure - calculates
2717 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2719 #if DEBUG_EXPAND || DEBUG_GLOB
2720 static void debug_print_list(const char *prefix, o_string *o, int n)
2722 char **list = (char**)o->data;
2723 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2727 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2728 prefix, list, n, string_start, o->length, o->maxlen,
2729 !!(o->o_expflags & EXP_FLAG_GLOB),
2731 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2734 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2735 o->data + (int)(uintptr_t)list[i] + string_start,
2736 o->data + (int)(uintptr_t)list[i] + string_start);
2740 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2742 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2746 # define debug_print_list(prefix, o, n) ((void)0)
2749 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2750 * in list[n] so that it points past last stored byte so far.
2751 * It returns n+1. */
2752 static int o_save_ptr_helper(o_string *o, int n)
2754 char **list = (char**)o->data;
2758 if (!o->has_empty_slot) {
2759 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2760 string_len = o->length - string_start;
2761 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2762 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2763 /* list[n] points to string_start, make space for 16 more pointers */
2764 o->maxlen += 0x10 * sizeof(list[0]);
2765 o->data = xrealloc(o->data, o->maxlen + 1);
2766 list = (char**)o->data;
2767 memmove(list + n + 0x10, list + n, string_len);
2768 o->length += 0x10 * sizeof(list[0]);
2770 debug_printf_list("list[%d]=%d string_start=%d\n",
2771 n, string_len, string_start);
2774 /* We have empty slot at list[n], reuse without growth */
2775 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2776 string_len = o->length - string_start;
2777 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2778 n, string_len, string_start);
2779 o->has_empty_slot = 0;
2781 o->has_quoted_part = 0;
2782 list[n] = (char*)(uintptr_t)string_len;
2786 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2787 static int o_get_last_ptr(o_string *o, int n)
2789 char **list = (char**)o->data;
2790 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2792 return ((int)(uintptr_t)list[n-1]) + string_start;
2795 #if ENABLE_HUSH_BRACE_EXPANSION
2796 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2797 * first, it processes even {a} (no commas), second,
2798 * I didn't manage to make it return strings when they don't match
2799 * existing files. Need to re-implement it.
2803 static int glob_needed(const char *s)
2812 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2818 /* Return pointer to next closing brace or to comma */
2819 static const char *next_brace_sub(const char *cp)
2823 while (*cp != '\0') {
2830 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2836 return *cp != '\0' ? cp : NULL;
2838 /* Recursive brace globber. Note: may garble pattern[]. */
2839 static int glob_brace(char *pattern, o_string *o, int n)
2841 char *new_pattern_buf;
2848 debug_printf_glob("glob_brace('%s')\n", pattern);
2854 if (*begin == '{') {
2855 /* Find the first sub-pattern and at the same time
2856 * find the rest after the closing brace */
2857 next = next_brace_sub(begin);
2859 /* An illegal expression */
2863 /* "{abc}" with no commas - illegal
2864 * brace expr, disregard and skip it */
2870 if (*begin == '\\' && begin[1] != '\0')
2874 debug_printf_glob("begin:%s\n", begin);
2875 debug_printf_glob("next:%s\n", next);
2877 /* Now find the end of the whole brace expression */
2879 while (*rest != '}') {
2880 rest = next_brace_sub(rest);
2882 /* An illegal expression */
2885 debug_printf_glob("rest:%s\n", rest);
2887 rest_len = strlen(++rest) + 1;
2889 /* We are sure the brace expression is well-formed */
2891 /* Allocate working buffer large enough for our work */
2892 new_pattern_buf = xmalloc(strlen(pattern));
2894 /* We have a brace expression. BEGIN points to the opening {,
2895 * NEXT points past the terminator of the first element, and REST
2896 * points past the final }. We will accumulate result names from
2897 * recursive runs for each brace alternative in the buffer using
2902 /* Construct the new glob expression */
2905 mempcpy(new_pattern_buf,
2906 /* We know the prefix for all sub-patterns */
2907 pattern, begin - pattern),
2911 /* Note: glob_brace() may garble new_pattern_buf[].
2912 * That's why we re-copy prefix every time (1st memcpy above).
2914 n = glob_brace(new_pattern_buf, o, n);
2916 /* We saw the last entry */
2920 next = next_brace_sub(next);
2922 free(new_pattern_buf);
2930 memset(&globdata, 0, sizeof(globdata));
2931 gr = glob(pattern, 0, NULL, &globdata);
2932 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2934 if (gr == GLOB_NOMATCH) {
2935 globfree(&globdata);
2936 /* NB: garbles parameter */
2937 unbackslash(pattern);
2938 o_addstr_with_NUL(o, pattern);
2939 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2940 return o_save_ptr_helper(o, n);
2942 if (gr == GLOB_NOSPACE)
2943 bb_error_msg_and_die(bb_msg_memory_exhausted);
2944 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2945 * but we didn't specify it. Paranoia again. */
2946 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2948 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2949 char **argv = globdata.gl_pathv;
2951 o_addstr_with_NUL(o, *argv);
2952 n = o_save_ptr_helper(o, n);
2958 globfree(&globdata);
2962 /* Performs globbing on last list[],
2963 * saving each result as a new list[].
2965 static int perform_glob(o_string *o, int n)
2967 char *pattern, *copy;
2969 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2971 return o_save_ptr_helper(o, n);
2972 pattern = o->data + o_get_last_ptr(o, n);
2973 debug_printf_glob("glob pattern '%s'\n", pattern);
2974 if (!glob_needed(pattern)) {
2975 /* unbackslash last string in o in place, fix length */
2976 o->length = unbackslash(pattern) - o->data;
2977 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2978 return o_save_ptr_helper(o, n);
2981 copy = xstrdup(pattern);
2982 /* "forget" pattern in o */
2983 o->length = pattern - o->data;
2984 n = glob_brace(copy, o, n);
2987 debug_print_list("perform_glob returning", o, n);
2991 #else /* !HUSH_BRACE_EXPANSION */
2994 static int glob_needed(const char *s)
3003 if (*s == '*' || *s == '[' || *s == '?')
3009 /* Performs globbing on last list[],
3010 * saving each result as a new list[].
3012 static int perform_glob(o_string *o, int n)
3018 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3020 return o_save_ptr_helper(o, n);
3021 pattern = o->data + o_get_last_ptr(o, n);
3022 debug_printf_glob("glob pattern '%s'\n", pattern);
3023 if (!glob_needed(pattern)) {
3025 /* unbackslash last string in o in place, fix length */
3026 o->length = unbackslash(pattern) - o->data;
3027 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3028 return o_save_ptr_helper(o, n);
3031 memset(&globdata, 0, sizeof(globdata));
3032 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3033 * If we glob "*.\*" and don't find anything, we need
3034 * to fall back to using literal "*.*", but GLOB_NOCHECK
3035 * will return "*.\*"!
3037 gr = glob(pattern, 0, NULL, &globdata);
3038 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3040 if (gr == GLOB_NOMATCH) {
3041 globfree(&globdata);
3044 if (gr == GLOB_NOSPACE)
3045 bb_error_msg_and_die(bb_msg_memory_exhausted);
3046 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3047 * but we didn't specify it. Paranoia again. */
3048 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3050 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3051 char **argv = globdata.gl_pathv;
3052 /* "forget" pattern in o */
3053 o->length = pattern - o->data;
3055 o_addstr_with_NUL(o, *argv);
3056 n = o_save_ptr_helper(o, n);
3062 globfree(&globdata);
3064 debug_print_list("perform_glob returning", o, n);
3068 #endif /* !HUSH_BRACE_EXPANSION */
3070 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3071 * Otherwise, just finish current list[] and start new */
3072 static int o_save_ptr(o_string *o, int n)
3074 if (o->o_expflags & EXP_FLAG_GLOB) {
3075 /* If o->has_empty_slot, list[n] was already globbed
3076 * (if it was requested back then when it was filled)
3077 * so don't do that again! */
3078 if (!o->has_empty_slot)
3079 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3081 return o_save_ptr_helper(o, n);
3084 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3085 static char **o_finalize_list(o_string *o, int n)
3090 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3092 debug_print_list("finalized", o, n);
3093 debug_printf_expand("finalized n:%d\n", n);
3094 list = (char**)o->data;
3095 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3099 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3104 static void free_pipe_list(struct pipe *pi);
3106 /* Returns pi->next - next pipe in the list */
3107 static struct pipe *free_pipe(struct pipe *pi)
3112 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3113 for (i = 0; i < pi->num_cmds; i++) {
3114 struct command *command;
3115 struct redir_struct *r, *rnext;
3117 command = &pi->cmds[i];
3118 debug_printf_clean(" command %d:\n", i);
3119 if (command->argv) {
3123 for (a = 0, p = command->argv; *p; a++, p++) {
3124 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3127 free_strings(command->argv);
3128 //command->argv = NULL;
3130 /* not "else if": on syntax error, we may have both! */
3131 if (command->group) {
3132 debug_printf_clean(" begin group (cmd_type:%d)\n",
3134 free_pipe_list(command->group);
3135 debug_printf_clean(" end group\n");
3136 //command->group = NULL;
3138 /* else is crucial here.
3139 * If group != NULL, child_func is meaningless */
3140 #if ENABLE_HUSH_FUNCTIONS
3141 else if (command->child_func) {
3142 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3143 command->child_func->parent_cmd = NULL;
3147 free(command->group_as_string);
3148 //command->group_as_string = NULL;
3150 for (r = command->redirects; r; r = rnext) {
3151 debug_printf_clean(" redirect %d%s",
3152 r->rd_fd, redir_table[r->rd_type].descrip);
3153 /* guard against the case >$FOO, where foo is unset or blank */
3154 if (r->rd_filename) {
3155 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3156 free(r->rd_filename);
3157 //r->rd_filename = NULL;
3159 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3163 //command->redirects = NULL;
3165 free(pi->cmds); /* children are an array, they get freed all at once */
3169 //pi->cmdtext = NULL;
3177 static void free_pipe_list(struct pipe *pi)
3181 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3183 debug_printf_clean("pipe followup code %d\n", pi->followup);
3189 /*** Parsing routines ***/
3191 #ifndef debug_print_tree
3192 static void debug_print_tree(struct pipe *pi, int lvl)
3194 static const char *const PIPE[] = {
3200 static const char *RES[] = {
3201 [RES_NONE ] = "NONE" ,
3204 [RES_THEN ] = "THEN" ,
3205 [RES_ELIF ] = "ELIF" ,
3206 [RES_ELSE ] = "ELSE" ,
3209 # if ENABLE_HUSH_LOOPS
3210 [RES_FOR ] = "FOR" ,
3211 [RES_WHILE] = "WHILE",
3212 [RES_UNTIL] = "UNTIL",
3214 [RES_DONE ] = "DONE" ,
3216 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3219 # if ENABLE_HUSH_CASE
3220 [RES_CASE ] = "CASE" ,
3221 [RES_CASE_IN ] = "CASE_IN" ,
3222 [RES_MATCH] = "MATCH",
3223 [RES_CASE_BODY] = "CASE_BODY",
3224 [RES_ESAC ] = "ESAC" ,
3226 [RES_XXXX ] = "XXXX" ,
3227 [RES_SNTX ] = "SNTX" ,
3229 static const char *const CMDTYPE[] = {
3233 # if ENABLE_HUSH_FUNCTIONS
3242 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3243 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3245 while (prn < pi->num_cmds) {
3246 struct command *command = &pi->cmds[prn];
3247 char **argv = command->argv;
3249 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3251 command->assignment_cnt);
3252 if (command->group) {
3253 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3254 CMDTYPE[command->cmd_type],
3257 , " group_as_string:", command->group_as_string
3262 debug_print_tree(command->group, lvl+1);
3266 if (argv) while (*argv) {
3267 fdprintf(2, " '%s'", *argv);
3277 #endif /* debug_print_tree */
3279 static struct pipe *new_pipe(void)
3282 pi = xzalloc(sizeof(struct pipe));
3283 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3287 /* Command (member of a pipe) is complete, or we start a new pipe
3288 * if ctx->command is NULL.
3289 * No errors possible here.
3291 static int done_command(struct parse_context *ctx)
3293 /* The command is really already in the pipe structure, so
3294 * advance the pipe counter and make a new, null command. */
3295 struct pipe *pi = ctx->pipe;
3296 struct command *command = ctx->command;
3298 #if 0 /* Instead we emit error message at run time */
3299 if (ctx->pending_redirect) {
3300 /* For example, "cmd >" (no filename to redirect to) */
3301 die_if_script("syntax error: %s", "invalid redirect");
3302 ctx->pending_redirect = NULL;
3307 if (IS_NULL_CMD(command)) {
3308 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3312 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3313 //debug_print_tree(ctx->list_head, 20);
3315 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3318 /* Only real trickiness here is that the uncommitted
3319 * command structure is not counted in pi->num_cmds. */
3320 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3321 ctx->command = command = &pi->cmds[pi->num_cmds];
3323 memset(command, 0, sizeof(*command));
3324 return pi->num_cmds; /* used only for 0/nonzero check */
3327 static void done_pipe(struct parse_context *ctx, pipe_style type)
3331 debug_printf_parse("done_pipe entered, followup %d\n", type);
3332 /* Close previous command */
3333 not_null = done_command(ctx);
3334 ctx->pipe->followup = type;
3336 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3337 ctx->ctx_inverted = 0;
3338 ctx->pipe->res_word = ctx->ctx_res_w;
3341 /* Without this check, even just <enter> on command line generates
3342 * tree of three NOPs (!). Which is harmless but annoying.
3343 * IOW: it is safe to do it unconditionally. */
3346 || ctx->ctx_res_w == RES_FI
3348 #if ENABLE_HUSH_LOOPS
3349 || ctx->ctx_res_w == RES_DONE
3350 || ctx->ctx_res_w == RES_FOR
3351 || ctx->ctx_res_w == RES_IN
3353 #if ENABLE_HUSH_CASE
3354 || ctx->ctx_res_w == RES_ESAC
3358 debug_printf_parse("done_pipe: adding new pipe: "
3359 "not_null:%d ctx->ctx_res_w:%d\n",
3360 not_null, ctx->ctx_res_w);
3362 ctx->pipe->next = new_p;
3364 /* RES_THEN, RES_DO etc are "sticky" -
3365 * they remain set for pipes inside if/while.
3366 * This is used to control execution.
3367 * RES_FOR and RES_IN are NOT sticky (needed to support
3368 * cases where variable or value happens to match a keyword):
3370 #if ENABLE_HUSH_LOOPS
3371 if (ctx->ctx_res_w == RES_FOR
3372 || ctx->ctx_res_w == RES_IN)
3373 ctx->ctx_res_w = RES_NONE;
3375 #if ENABLE_HUSH_CASE
3376 if (ctx->ctx_res_w == RES_MATCH)
3377 ctx->ctx_res_w = RES_CASE_BODY;
3378 if (ctx->ctx_res_w == RES_CASE)
3379 ctx->ctx_res_w = RES_CASE_IN;
3381 ctx->command = NULL; /* trick done_command below */
3382 /* Create the memory for command, roughly:
3383 * ctx->pipe->cmds = new struct command;
3384 * ctx->command = &ctx->pipe->cmds[0];
3387 //debug_print_tree(ctx->list_head, 10);
3389 debug_printf_parse("done_pipe return\n");
3392 static void initialize_context(struct parse_context *ctx)
3394 memset(ctx, 0, sizeof(*ctx));
3395 ctx->pipe = ctx->list_head = new_pipe();
3396 /* Create the memory for command, roughly:
3397 * ctx->pipe->cmds = new struct command;
3398 * ctx->command = &ctx->pipe->cmds[0];
3403 /* If a reserved word is found and processed, parse context is modified
3404 * and 1 is returned.
3407 struct reserved_combo {
3410 unsigned char assignment_flag;
3414 FLAG_END = (1 << RES_NONE ),
3416 FLAG_IF = (1 << RES_IF ),
3417 FLAG_THEN = (1 << RES_THEN ),
3418 FLAG_ELIF = (1 << RES_ELIF ),
3419 FLAG_ELSE = (1 << RES_ELSE ),
3420 FLAG_FI = (1 << RES_FI ),
3422 # if ENABLE_HUSH_LOOPS
3423 FLAG_FOR = (1 << RES_FOR ),
3424 FLAG_WHILE = (1 << RES_WHILE),
3425 FLAG_UNTIL = (1 << RES_UNTIL),
3426 FLAG_DO = (1 << RES_DO ),
3427 FLAG_DONE = (1 << RES_DONE ),
3428 FLAG_IN = (1 << RES_IN ),
3430 # if ENABLE_HUSH_CASE
3431 FLAG_MATCH = (1 << RES_MATCH),
3432 FLAG_ESAC = (1 << RES_ESAC ),
3434 FLAG_START = (1 << RES_XXXX ),
3437 static const struct reserved_combo* match_reserved_word(o_string *word)
3439 /* Mostly a list of accepted follow-up reserved words.
3440 * FLAG_END means we are done with the sequence, and are ready
3441 * to turn the compound list into a command.
3442 * FLAG_START means the word must start a new compound list.
3444 static const struct reserved_combo reserved_list[] = {
3446 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3447 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3448 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3449 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3450 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3451 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3453 # if ENABLE_HUSH_LOOPS
3454 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3455 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3456 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3457 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3458 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3459 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3461 # if ENABLE_HUSH_CASE
3462 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3463 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3466 const struct reserved_combo *r;
3468 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3469 if (strcmp(word->data, r->literal) == 0)
3474 /* Return 0: not a keyword, 1: keyword
3476 static int reserved_word(o_string *word, struct parse_context *ctx)
3478 # if ENABLE_HUSH_CASE
3479 static const struct reserved_combo reserved_match = {
3480 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3483 const struct reserved_combo *r;
3485 if (word->has_quoted_part)
3487 r = match_reserved_word(word);
3491 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3492 # if ENABLE_HUSH_CASE
3493 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3494 /* "case word IN ..." - IN part starts first MATCH part */
3495 r = &reserved_match;
3498 if (r->flag == 0) { /* '!' */
3499 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3500 syntax_error("! ! command");
3501 ctx->ctx_res_w = RES_SNTX;
3503 ctx->ctx_inverted = 1;
3506 if (r->flag & FLAG_START) {
3507 struct parse_context *old;
3509 old = xmalloc(sizeof(*old));
3510 debug_printf_parse("push stack %p\n", old);
3511 *old = *ctx; /* physical copy */
3512 initialize_context(ctx);
3514 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3515 syntax_error_at(word->data);
3516 ctx->ctx_res_w = RES_SNTX;
3519 /* "{...} fi" is ok. "{...} if" is not
3521 * if { echo foo; } then { echo bar; } fi */
3522 if (ctx->command->group)
3523 done_pipe(ctx, PIPE_SEQ);
3526 ctx->ctx_res_w = r->res;
3527 ctx->old_flag = r->flag;
3528 word->o_assignment = r->assignment_flag;
3529 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3531 if (ctx->old_flag & FLAG_END) {
3532 struct parse_context *old;
3534 done_pipe(ctx, PIPE_SEQ);
3535 debug_printf_parse("pop stack %p\n", ctx->stack);
3537 old->command->group = ctx->list_head;
3538 old->command->cmd_type = CMD_NORMAL;
3540 /* At this point, the compound command's string is in
3541 * ctx->as_string... except for the leading keyword!
3542 * Consider this example: "echo a | if true; then echo a; fi"
3543 * ctx->as_string will contain "true; then echo a; fi",
3544 * with "if " remaining in old->as_string!
3548 int len = old->as_string.length;
3549 /* Concatenate halves */
3550 o_addstr(&old->as_string, ctx->as_string.data);
3551 o_free_unsafe(&ctx->as_string);
3552 /* Find where leading keyword starts in first half */
3553 str = old->as_string.data + len;
3554 if (str > old->as_string.data)
3555 str--; /* skip whitespace after keyword */
3556 while (str > old->as_string.data && isalpha(str[-1]))
3558 /* Ugh, we're done with this horrid hack */
3559 old->command->group_as_string = xstrdup(str);
3560 debug_printf_parse("pop, remembering as:'%s'\n",
3561 old->command->group_as_string);
3564 *ctx = *old; /* physical copy */
3569 #endif /* HAS_KEYWORDS */
3571 /* Word is complete, look at it and update parsing context.
3572 * Normal return is 0. Syntax errors return 1.
3573 * Note: on return, word is reset, but not o_free'd!
3575 static int done_word(o_string *word, struct parse_context *ctx)
3577 struct command *command = ctx->command;
3579 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3580 if (word->length == 0 && !word->has_quoted_part) {
3581 debug_printf_parse("done_word return 0: true null, ignored\n");
3585 if (ctx->pending_redirect) {
3586 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3587 * only if run as "bash", not "sh" */
3588 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3590 * ...the word that follows the redirection operator
3591 * shall be subjected to tilde expansion, parameter expansion,
3592 * command substitution, arithmetic expansion, and quote
3593 * removal. Pathname expansion shall not be performed
3594 * on the word by a non-interactive shell; an interactive
3595 * shell may perform it, but shall do so only when
3596 * the expansion would result in one word."
3598 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3599 /* Cater for >\file case:
3600 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3601 * Same with heredocs:
3602 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3604 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3605 unbackslash(ctx->pending_redirect->rd_filename);
3606 /* Is it <<"HEREDOC"? */
3607 if (word->has_quoted_part) {
3608 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3611 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3612 ctx->pending_redirect = NULL;
3615 # if ENABLE_HUSH_CASE
3616 if (ctx->ctx_dsemicolon
3617 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3619 /* already done when ctx_dsemicolon was set to 1: */
3620 /* ctx->ctx_res_w = RES_MATCH; */
3621 ctx->ctx_dsemicolon = 0;
3624 if (!command->argv /* if it's the first word... */
3625 # if ENABLE_HUSH_LOOPS
3626 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3627 && ctx->ctx_res_w != RES_IN
3629 # if ENABLE_HUSH_CASE
3630 && ctx->ctx_res_w != RES_CASE
3633 int reserved = reserved_word(word, ctx);
3634 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3636 o_reset_to_empty_unquoted(word);
3637 debug_printf_parse("done_word return %d\n",
3638 (ctx->ctx_res_w == RES_SNTX));
3639 return (ctx->ctx_res_w == RES_SNTX);
3642 if (strcmp(word->data, "[[") == 0) {
3643 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3649 if (command->group) {
3650 /* "{ echo foo; } echo bar" - bad */
3651 syntax_error_at(word->data);
3652 debug_printf_parse("done_word return 1: syntax error, "
3653 "groups and arglists don't mix\n");
3657 /* If this word wasn't an assignment, next ones definitely
3658 * can't be assignments. Even if they look like ones. */
3659 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3660 && word->o_assignment != WORD_IS_KEYWORD
3662 word->o_assignment = NOT_ASSIGNMENT;
3664 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3665 command->assignment_cnt++;
3666 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3668 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3669 word->o_assignment = MAYBE_ASSIGNMENT;
3671 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3673 if (word->has_quoted_part
3674 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3675 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3676 /* (otherwise it's known to be not empty and is already safe) */
3678 /* exclude "$@" - it can expand to no word despite "" */
3679 char *p = word->data;
3680 while (p[0] == SPECIAL_VAR_SYMBOL
3681 && (p[1] & 0x7f) == '@'
3682 && p[2] == SPECIAL_VAR_SYMBOL
3687 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3688 debug_print_strings("word appended to argv", command->argv);
3691 #if ENABLE_HUSH_LOOPS
3692 if (ctx->ctx_res_w == RES_FOR) {
3693 if (word->has_quoted_part
3694 || !is_well_formed_var_name(command->argv[0], '\0')
3696 /* bash says just "not a valid identifier" */
3697 syntax_error("not a valid identifier in for");
3700 /* Force FOR to have just one word (variable name) */
3701 /* NB: basically, this makes hush see "for v in ..."
3702 * syntax as if it is "for v; in ...". FOR and IN become
3703 * two pipe structs in parse tree. */
3704 done_pipe(ctx, PIPE_SEQ);
3707 #if ENABLE_HUSH_CASE
3708 /* Force CASE to have just one word */
3709 if (ctx->ctx_res_w == RES_CASE) {
3710 done_pipe(ctx, PIPE_SEQ);
3714 o_reset_to_empty_unquoted(word);
3716 debug_printf_parse("done_word return 0\n");
3721 /* Peek ahead in the input to find out if we have a "&n" construct,
3722 * as in "2>&1", that represents duplicating a file descriptor.
3724 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3725 * REDIRFD_SYNTAX_ERR if syntax error,
3726 * REDIRFD_TO_FILE if no & was seen,
3727 * or the number found.
3730 #define parse_redir_right_fd(as_string, input) \
3731 parse_redir_right_fd(input)
3733 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3739 return REDIRFD_TO_FILE;
3741 ch = i_getch(input); /* get the & */
3742 nommu_addchr(as_string, ch);
3745 ch = i_getch(input);
3746 nommu_addchr(as_string, ch);
3747 return REDIRFD_CLOSE;
3751 while (ch != EOF && isdigit(ch)) {
3752 d = d*10 + (ch-'0');
3754 ch = i_getch(input);
3755 nommu_addchr(as_string, ch);
3760 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3762 bb_error_msg("ambiguous redirect");
3763 return REDIRFD_SYNTAX_ERR;
3766 /* Return code is 0 normal, 1 if a syntax error is detected
3768 static int parse_redirect(struct parse_context *ctx,
3771 struct in_str *input)
3773 struct command *command = ctx->command;
3774 struct redir_struct *redir;
3775 struct redir_struct **redirp;
3778 dup_num = REDIRFD_TO_FILE;
3779 if (style != REDIRECT_HEREDOC) {
3780 /* Check for a '>&1' type redirect */
3781 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3782 if (dup_num == REDIRFD_SYNTAX_ERR)
3785 int ch = i_peek(input);
3786 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3787 if (dup_num) { /* <<-... */
3788 ch = i_getch(input);
3789 nommu_addchr(&ctx->as_string, ch);
3794 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3795 int ch = i_peek(input);
3797 /* >|FILE redirect ("clobbering" >).
3798 * Since we do not support "set -o noclobber" yet,
3799 * >| and > are the same for now. Just eat |.
3801 ch = i_getch(input);
3802 nommu_addchr(&ctx->as_string, ch);
3806 /* Create a new redir_struct and append it to the linked list */
3807 redirp = &command->redirects;
3808 while ((redir = *redirp) != NULL) {
3809 redirp = &(redir->next);
3811 *redirp = redir = xzalloc(sizeof(*redir));
3812 /* redir->next = NULL; */
3813 /* redir->rd_filename = NULL; */
3814 redir->rd_type = style;
3815 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3817 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3818 redir_table[style].descrip);
3820 redir->rd_dup = dup_num;
3821 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3822 /* Erik had a check here that the file descriptor in question
3823 * is legit; I postpone that to "run time"
3824 * A "-" representation of "close me" shows up as a -3 here */
3825 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3826 redir->rd_fd, redir->rd_dup);
3828 #if 0 /* Instead we emit error message at run time */
3829 if (ctx->pending_redirect) {
3830 /* For example, "cmd > <file" */
3831 die_if_script("syntax error: %s", "invalid redirect");
3834 /* Set ctx->pending_redirect, so we know what to do at the
3835 * end of the next parsed word. */
3836 ctx->pending_redirect = redir;
3841 /* If a redirect is immediately preceded by a number, that number is
3842 * supposed to tell which file descriptor to redirect. This routine
3843 * looks for such preceding numbers. In an ideal world this routine
3844 * needs to handle all the following classes of redirects...
3845 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3846 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3847 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3848 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3850 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3852 * ... If n is quoted, the number shall not be recognized as part of
3853 * the redirection expression. For example:
3855 * writes the character 2 into file a"
3856 * We are getting it right by setting ->has_quoted_part on any \<char>
3858 * A -1 return means no valid number was found,
3859 * the caller should use the appropriate default for this redirection.
3861 static int redirect_opt_num(o_string *o)
3865 if (o->data == NULL)
3867 num = bb_strtou(o->data, NULL, 10);
3868 if (errno || num < 0)
3870 o_reset_to_empty_unquoted(o);
3875 #define fetch_till_str(as_string, input, word, skip_tabs) \
3876 fetch_till_str(input, word, skip_tabs)
3878 static char *fetch_till_str(o_string *as_string,
3879 struct in_str *input,
3883 o_string heredoc = NULL_O_STRING;
3885 int prev = 0; /* not \ */
3891 ch = i_getch(input);
3893 nommu_addchr(as_string, ch);
3894 if ((ch == '\n' || ch == EOF)
3895 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3897 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3898 heredoc.data[past_EOL] = '\0';
3899 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3900 return heredoc.data;
3902 while (ch == '\n') {
3903 o_addchr(&heredoc, ch);
3906 past_EOL = heredoc.length;
3908 ch = i_getch(input);
3910 nommu_addchr(as_string, ch);
3911 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3915 o_free_unsafe(&heredoc);
3918 o_addchr(&heredoc, ch);
3919 nommu_addchr(as_string, ch);
3920 if (prev == '\\' && ch == '\\')
3921 /* Correctly handle foo\\<eol> (not a line cont.) */
3922 prev = 0; /* not \ */
3928 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3929 * and load them all. There should be exactly heredoc_cnt of them.
3931 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3933 struct pipe *pi = ctx->list_head;
3935 while (pi && heredoc_cnt) {
3937 struct command *cmd = pi->cmds;
3939 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3941 cmd->argv ? cmd->argv[0] : "NONE");
3942 for (i = 0; i < pi->num_cmds; i++) {
3943 struct redir_struct *redir = cmd->redirects;
3945 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3946 i, cmd->argv ? cmd->argv[0] : "NONE");
3948 if (redir->rd_type == REDIRECT_HEREDOC) {
3951 redir->rd_type = REDIRECT_HEREDOC2;
3952 /* redir->rd_dup is (ab)used to indicate <<- */
3953 p = fetch_till_str(&ctx->as_string, input,
3954 redir->rd_filename, redir->rd_dup);
3956 syntax_error("unexpected EOF in here document");
3959 free(redir->rd_filename);
3960 redir->rd_filename = p;
3963 redir = redir->next;
3970 /* Should be 0. If it isn't, it's a parse error */
3972 bb_error_msg_and_die("heredoc BUG 2");
3978 static int run_list(struct pipe *pi);
3980 #define parse_stream(pstring, input, end_trigger) \
3981 parse_stream(input, end_trigger)
3983 static struct pipe *parse_stream(char **pstring,
3984 struct in_str *input,
3988 #if !ENABLE_HUSH_FUNCTIONS
3989 #define parse_group(dest, ctx, input, ch) \
3990 parse_group(ctx, input, ch)
3992 static int parse_group(o_string *dest, struct parse_context *ctx,
3993 struct in_str *input, int ch)
3995 /* dest contains characters seen prior to ( or {.
3996 * Typically it's empty, but for function defs,
3997 * it contains function name (without '()'). */
3998 struct pipe *pipe_list;
4000 struct command *command = ctx->command;
4002 debug_printf_parse("parse_group entered\n");
4003 #if ENABLE_HUSH_FUNCTIONS
4004 if (ch == '(' && !dest->has_quoted_part) {
4006 if (done_word(dest, ctx))
4009 goto skip; /* (... */
4010 if (command->argv[1]) { /* word word ... (... */
4011 syntax_error_unexpected_ch('(');
4014 /* it is "word(..." or "word (..." */
4016 ch = i_getch(input);
4017 while (ch == ' ' || ch == '\t');
4019 syntax_error_unexpected_ch(ch);
4022 nommu_addchr(&ctx->as_string, ch);
4024 ch = i_getch(input);
4025 while (ch == ' ' || ch == '\t' || ch == '\n');
4027 syntax_error_unexpected_ch(ch);
4030 nommu_addchr(&ctx->as_string, ch);
4031 command->cmd_type = CMD_FUNCDEF;
4036 #if 0 /* Prevented by caller */
4037 if (command->argv /* word [word]{... */
4038 || dest->length /* word{... */
4039 || dest->has_quoted_part /* ""{... */
4042 debug_printf_parse("parse_group return 1: "
4043 "syntax error, groups and arglists don't mix\n");
4048 #if ENABLE_HUSH_FUNCTIONS
4054 command->cmd_type = CMD_SUBSHELL;
4056 /* bash does not allow "{echo...", requires whitespace */
4058 if (ch != ' ' && ch != '\t' && ch != '\n'
4059 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4061 syntax_error_unexpected_ch(ch);
4065 ch = i_getch(input);
4066 nommu_addchr(&ctx->as_string, ch);
4072 # define as_string NULL
4074 char *as_string = NULL;
4076 pipe_list = parse_stream(&as_string, input, endch);
4079 o_addstr(&ctx->as_string, as_string);
4081 /* empty ()/{} or parse error? */
4082 if (!pipe_list || pipe_list == ERR_PTR) {
4083 /* parse_stream already emitted error msg */
4086 debug_printf_parse("parse_group return 1: "
4087 "parse_stream returned %p\n", pipe_list);
4090 command->group = pipe_list;
4092 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4093 command->group_as_string = as_string;
4094 debug_printf_parse("end of group, remembering as:'%s'\n",
4095 command->group_as_string);
4099 debug_printf_parse("parse_group return 0\n");
4101 /* command remains "open", available for possible redirects */
4104 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4109 ch = i_getch(input);
4112 ch2 = i_peek(input);
4115 /* backslash+newline, skip it */
4120 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4128 ch2 = i_peek2(input);
4131 /* backslash+newline, skip it */
4137 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4138 /* Subroutines for copying $(...) and `...` things */
4139 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4141 static int add_till_single_quote(o_string *dest, struct in_str *input)
4144 int ch = i_getch(input);
4146 syntax_error_unterm_ch('\'');
4154 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4155 static int add_till_double_quote(o_string *dest, struct in_str *input)
4158 int ch = i_getch(input);
4160 syntax_error_unterm_ch('"');
4165 if (ch == '\\') { /* \x. Copy both chars. */
4167 ch = i_getch(input);
4171 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4176 //if (ch == '$') ...
4179 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4181 * "Within the backquoted style of command substitution, backslash
4182 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4183 * The search for the matching backquote shall be satisfied by the first
4184 * backquote found without a preceding backslash; during this search,
4185 * if a non-escaped backquote is encountered within a shell comment,
4186 * a here-document, an embedded command substitution of the $(command)
4187 * form, or a quoted string, undefined results occur. A single-quoted
4188 * or double-quoted string that begins, but does not end, within the
4189 * "`...`" sequence produces undefined results."
4191 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4193 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4196 int ch = i_getch(input);
4200 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4201 ch = i_getch(input);
4205 && (!in_dquote || ch != '"')
4207 o_addchr(dest, '\\');
4211 syntax_error_unterm_ch('`');
4217 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4218 * quoting and nested ()s.
4219 * "With the $(command) style of command substitution, all characters
4220 * following the open parenthesis to the matching closing parenthesis
4221 * constitute the command. Any valid shell script can be used for command,
4222 * except a script consisting solely of redirections which produces
4223 * unspecified results."
4225 * echo $(echo '(TEST)' BEST) (TEST) BEST
4226 * echo $(echo 'TEST)' BEST) TEST) BEST
4227 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4229 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4230 * can contain arbitrary constructs, just like $(cmd).
4231 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4232 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4234 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4235 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4238 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4239 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4240 char end_char2 = end_ch >> 8;
4242 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4245 ch = i_getch(input);
4247 syntax_error_unterm_ch(end_ch);
4251 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4257 /* we look for closing )) of $((EXPR)) */
4258 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4259 i_getch(input); /* eat second ')' */
4264 if (ch == '(' || ch == '{') {
4265 ch = (ch == '(' ? ')' : '}');
4266 if (!add_till_closing_bracket(dest, input, ch))
4272 if (!add_till_single_quote(dest, input))
4278 if (!add_till_double_quote(dest, input))
4284 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4290 /* \x. Copy verbatim. Important for \(, \) */
4291 ch = i_getch(input);
4293 syntax_error_unterm_ch(')');
4298 /* "backslash+newline", ignore both */
4299 o_delchr(dest); /* undo insertion of '\' */
4309 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4311 /* Return code: 0 for OK, 1 for syntax error */
4313 #define parse_dollar(as_string, dest, input, quote_mask) \
4314 parse_dollar(dest, input, quote_mask)
4315 #define as_string NULL
4317 static int parse_dollar(o_string *as_string,
4319 struct in_str *input, unsigned char quote_mask)
4321 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4323 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4325 ch = i_getch(input);
4326 nommu_addchr(as_string, ch);
4328 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4330 debug_printf_parse(": '%c'\n", ch);
4331 o_addchr(dest, ch | quote_mask);
4333 ch = i_peek_and_eat_bkslash_nl(input);
4334 if (!isalnum(ch) && ch != '_') {
4335 /* End of variable name reached */
4338 ch = i_getch(input);
4339 nommu_addchr(as_string, ch);
4341 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4342 } else if (isdigit(ch)) {
4344 ch = i_getch(input);
4345 nommu_addchr(as_string, ch);
4346 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4347 debug_printf_parse(": '%c'\n", ch);
4348 o_addchr(dest, ch | quote_mask);
4349 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4350 } else switch (ch) {
4352 case '!': /* last bg pid */
4353 case '?': /* last exit code */
4354 case '#': /* number of args */
4355 case '*': /* args */
4356 case '@': /* args */
4357 goto make_one_char_var;
4359 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4361 ch = i_getch(input); /* eat '{' */
4362 nommu_addchr(as_string, ch);
4364 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4365 /* It should be ${?}, or ${#var},
4366 * or even ${?+subst} - operator acting on a special variable,
4367 * or the beginning of variable name.
4370 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4373 syntax_error_unterm_str("${name}");
4374 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4377 nommu_addchr(as_string, ch);
4380 /* It's possible to just call add_till_closing_bracket() at this point.
4381 * However, this regresses some of our testsuite cases
4382 * which check invalid constructs like ${%}.
4383 * Oh well... let's check that the var name part is fine... */
4389 debug_printf_parse(": '%c'\n", ch);
4391 ch = i_getch(input);
4392 nommu_addchr(as_string, ch);
4396 if (!isalnum(ch) && ch != '_') {
4398 unsigned char last_ch;
4399 /* handle parameter expansions
4400 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4402 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4403 goto bad_dollar_syntax;
4405 /* Eat everything until closing '}' (or ':') */
4409 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4411 /* It's ${var:N[:M]} thing */
4412 end_ch = '}' * 0x100 + ':';
4414 if (BASH_PATTERN_SUBST
4417 /* It's ${var/[/]pattern[/repl]} thing */
4418 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4420 nommu_addchr(as_string, '/');
4423 end_ch = '}' * 0x100 + '/';
4429 #if ENABLE_HUSH_DOLLAR_OPS
4430 last_ch = add_till_closing_bracket(dest, input, end_ch);
4431 if (last_ch == 0) /* error? */
4434 #error Simple code to only allow ${var} is not implemented
4437 o_addstr(as_string, dest->data + pos);
4438 o_addchr(as_string, last_ch);
4441 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4442 && (end_ch & 0xff00)
4444 /* close the first block: */
4445 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4446 /* while parsing N from ${var:N[:M]}
4447 * or pattern from ${var/[/]pattern[/repl]} */
4448 if ((end_ch & 0xff) == last_ch) {
4449 /* got ':' or '/'- parse the rest */
4454 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4455 /* it's ${var:N} - emulate :999999999 */
4456 o_addstr(dest, "999999999");
4457 } /* else: it's ${var/[/]pattern} */
4462 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4465 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4469 ch = i_getch(input);
4470 nommu_addchr(as_string, ch);
4471 # if ENABLE_FEATURE_SH_MATH
4472 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4473 ch = i_getch(input);
4474 nommu_addchr(as_string, ch);
4475 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4476 o_addchr(dest, /*quote_mask |*/ '+');
4479 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4480 return 0; /* error */
4482 o_addstr(as_string, dest->data + pos);
4483 o_addchr(as_string, ')');
4484 o_addchr(as_string, ')');
4486 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4490 # if ENABLE_HUSH_TICK
4491 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4492 o_addchr(dest, quote_mask | '`');
4495 if (!add_till_closing_bracket(dest, input, ')'))
4496 return 0; /* error */
4498 o_addstr(as_string, dest->data + pos);
4499 o_addchr(as_string, ')');
4501 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4507 ch = i_getch(input);
4508 nommu_addchr(as_string, ch);
4509 ch = i_peek_and_eat_bkslash_nl(input);
4510 if (isalnum(ch)) { /* it's $_name or $_123 */
4515 /* TODO: $_ and $-: */
4516 /* $_ Shell or shell script name; or last argument of last command
4517 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4518 * but in command's env, set to full pathname used to invoke it */
4519 /* $- Option flags set by set builtin or shell options (-i etc) */
4521 o_addQchr(dest, '$');
4523 debug_printf_parse("parse_dollar return 1 (ok)\n");
4529 # if BASH_PATTERN_SUBST
4530 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4531 encode_string(dest, input, dquote_end, process_bkslash)
4533 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4534 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4535 encode_string(dest, input, dquote_end)
4537 #define as_string NULL
4541 # if BASH_PATTERN_SUBST
4542 /* all parameters are needed, no macro tricks */
4544 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4545 encode_string(as_string, dest, input, dquote_end)
4548 static int encode_string(o_string *as_string,
4550 struct in_str *input,
4552 int process_bkslash)
4554 #if !BASH_PATTERN_SUBST
4555 const int process_bkslash = 1;
4561 ch = i_getch(input);
4563 nommu_addchr(as_string, ch);
4564 if (ch == dquote_end) { /* may be only '"' or EOF */
4565 debug_printf_parse("encode_string return 1 (ok)\n");
4568 /* note: can't move it above ch == dquote_end check! */
4570 syntax_error_unterm_ch('"');
4571 return 0; /* error */
4575 next = i_peek(input);
4577 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4578 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4579 if (process_bkslash && ch == '\\') {
4581 syntax_error("\\<eof>");
4585 * "The backslash retains its special meaning [in "..."]
4586 * only when followed by one of the following characters:
4587 * $, `, ", \, or <newline>. A double quote may be quoted
4588 * within double quotes by preceding it with a backslash."
4589 * NB: in (unquoted) heredoc, above does not apply to ",
4590 * therefore we check for it by "next == dquote_end" cond.
4592 if (next == dquote_end || strchr("$`\\\n", next)) {
4593 ch = i_getch(input); /* eat next */
4595 goto again; /* skip \<newline> */
4596 } /* else: ch remains == '\\', and we double it below: */
4597 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4598 nommu_addchr(as_string, ch);
4602 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4603 debug_printf_parse("encode_string return 0: "
4604 "parse_dollar returned 0 (error)\n");
4609 #if ENABLE_HUSH_TICK
4611 //unsigned pos = dest->length;
4612 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4613 o_addchr(dest, 0x80 | '`');
4614 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4615 return 0; /* error */
4616 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4617 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4621 o_addQchr(dest, ch);
4627 * Scan input until EOF or end_trigger char.
4628 * Return a list of pipes to execute, or NULL on EOF
4629 * or if end_trigger character is met.
4630 * On syntax error, exit if shell is not interactive,
4631 * reset parsing machinery and start parsing anew,
4632 * or return ERR_PTR.
4634 static struct pipe *parse_stream(char **pstring,
4635 struct in_str *input,
4638 struct parse_context ctx;
4639 o_string dest = NULL_O_STRING;
4642 /* Single-quote triggers a bypass of the main loop until its mate is
4643 * found. When recursing, quote state is passed in via dest->o_expflags.
4645 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4646 end_trigger ? end_trigger : 'X');
4649 /* If very first arg is "" or '', dest.data may end up NULL.
4650 * Preventing this: */
4651 o_addchr(&dest, '\0');
4654 /* We used to separate words on $IFS here. This was wrong.
4655 * $IFS is used only for word splitting when $var is expanded,
4656 * here we should use blank chars as separators, not $IFS
4659 if (MAYBE_ASSIGNMENT != 0)
4660 dest.o_assignment = MAYBE_ASSIGNMENT;
4661 initialize_context(&ctx);
4664 const char *is_blank;
4665 const char *is_special;
4669 redir_type redir_style;
4671 ch = i_getch(input);
4672 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4673 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4678 syntax_error_unterm_str("here document");
4681 if (end_trigger == ')') {
4682 syntax_error_unterm_ch('(');
4685 if (end_trigger == '}') {
4686 syntax_error_unterm_ch('{');
4690 if (done_word(&dest, &ctx)) {
4694 done_pipe(&ctx, PIPE_SEQ);
4696 /* If we got nothing... */
4697 /* (this makes bare "&" cmd a no-op.
4698 * bash says: "syntax error near unexpected token '&'") */
4699 if (pi->num_cmds == 0
4700 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4706 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4708 *pstring = ctx.as_string.data;
4710 o_free_unsafe(&ctx.as_string);
4713 debug_printf_parse("parse_stream return %p\n", pi);
4716 nommu_addchr(&ctx.as_string, ch);
4720 next = i_peek(input);
4722 is_special = "{}<>;&|()#'" /* special outside of "str" */
4723 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4724 /* Are { and } special here? */
4725 if (ctx.command->argv /* word [word]{... - non-special */
4726 || dest.length /* word{... - non-special */
4727 || dest.has_quoted_part /* ""{... - non-special */
4728 || (next != ';' /* }; - special */
4729 && next != ')' /* }) - special */
4730 && next != '(' /* {( - special */
4731 && next != '&' /* }& and }&& ... - special */
4732 && next != '|' /* }|| ... - special */
4733 && !strchr(defifs, next) /* {word - non-special */
4736 /* They are not special, skip "{}" */
4739 is_special = strchr(is_special, ch);
4740 is_blank = strchr(defifs, ch);
4742 if (!is_special && !is_blank) { /* ordinary char */
4744 o_addQchr(&dest, ch);
4745 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4746 || dest.o_assignment == WORD_IS_KEYWORD)
4748 && is_well_formed_var_name(dest.data, '=')
4750 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4751 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4757 if (done_word(&dest, &ctx)) {
4761 /* Is this a case when newline is simply ignored?
4763 * "cmd | <newline> cmd ..."
4764 * "case ... in <newline> word) ..."
4766 if (IS_NULL_CMD(ctx.command)
4767 && dest.length == 0 && !dest.has_quoted_part
4769 /* This newline can be ignored. But...
4770 * Without check #1, interactive shell
4771 * ignores even bare <newline>,
4772 * and shows the continuation prompt:
4773 * ps1_prompt$ <enter>
4774 * ps2> _ <=== wrong, should be ps1
4775 * Without check #2, "cmd & <newline>"
4776 * is similarly mistreated.
4777 * (BTW, this makes "cmd & cmd"
4778 * and "cmd && cmd" non-orthogonal.
4779 * Really, ask yourself, why
4780 * "cmd && <newline>" doesn't start
4781 * cmd but waits for more input?
4784 struct pipe *pi = ctx.list_head;
4785 if (pi->num_cmds != 0 /* check #1 */
4786 && pi->followup != PIPE_BG /* check #2 */
4791 /* Treat newline as a command separator. */
4792 done_pipe(&ctx, PIPE_SEQ);
4793 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4795 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4800 dest.o_assignment = MAYBE_ASSIGNMENT;
4801 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4803 /* note: if (is_blank) continue;
4804 * will still trigger for us */
4808 /* "cmd}" or "cmd }..." without semicolon or &:
4809 * } is an ordinary char in this case, even inside { cmd; }
4810 * Pathological example: { ""}; } should exec "}" cmd
4813 if (dest.length != 0 /* word} */
4814 || dest.has_quoted_part /* ""} */
4818 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4819 /* Generally, there should be semicolon: "cmd; }"
4820 * However, bash allows to omit it if "cmd" is
4821 * a group. Examples:
4824 * { echo 0 >&2 | { echo 1; } }
4825 * { while false; do :; done }
4826 * { case a in b) ;; esac }
4828 if (ctx.command->group)
4832 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4833 /* Can't be an end of {cmd}, skip the check */
4834 goto skip_end_trigger;
4835 /* else: } does terminate a group */
4838 if (end_trigger && end_trigger == ch
4839 && (ch != ';' || heredoc_cnt == 0)
4840 #if ENABLE_HUSH_CASE
4842 || ctx.ctx_res_w != RES_MATCH
4843 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4848 /* This is technically valid:
4849 * { cat <<HERE; }; echo Ok
4853 * but we don't support this.
4854 * We require heredoc to be in enclosing {}/(),
4857 syntax_error_unterm_str("here document");
4860 if (done_word(&dest, &ctx)) {
4863 done_pipe(&ctx, PIPE_SEQ);
4864 dest.o_assignment = MAYBE_ASSIGNMENT;
4865 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4866 /* Do we sit outside of any if's, loops or case's? */
4868 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4872 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4874 *pstring = ctx.as_string.data;
4876 o_free_unsafe(&ctx.as_string);
4879 debug_printf_parse("parse_stream return %p: "
4880 "end_trigger char found\n",
4882 return ctx.list_head;
4889 /* Catch <, > before deciding whether this word is
4890 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4893 redir_fd = redirect_opt_num(&dest);
4894 if (done_word(&dest, &ctx)) {
4897 redir_style = REDIRECT_OVERWRITE;
4899 redir_style = REDIRECT_APPEND;
4900 ch = i_getch(input);
4901 nommu_addchr(&ctx.as_string, ch);
4904 else if (next == '(') {
4905 syntax_error(">(process) not supported");
4909 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4911 continue; /* back to top of while (1) */
4913 redir_fd = redirect_opt_num(&dest);
4914 if (done_word(&dest, &ctx)) {
4917 redir_style = REDIRECT_INPUT;
4919 redir_style = REDIRECT_HEREDOC;
4921 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4922 ch = i_getch(input);
4923 nommu_addchr(&ctx.as_string, ch);
4924 } else if (next == '>') {
4925 redir_style = REDIRECT_IO;
4926 ch = i_getch(input);
4927 nommu_addchr(&ctx.as_string, ch);
4930 else if (next == '(') {
4931 syntax_error("<(process) not supported");
4935 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4937 continue; /* back to top of while (1) */
4939 if (dest.length == 0 && !dest.has_quoted_part) {
4940 /* skip "#comment" */
4943 if (ch == EOF || ch == '\n')
4946 /* note: we do not add it to &ctx.as_string */
4948 nommu_addchr(&ctx.as_string, '\n');
4949 continue; /* back to top of while (1) */
4954 /* It's "\<newline>" */
4956 /* Remove trailing '\' from ctx.as_string */
4957 ctx.as_string.data[--ctx.as_string.length] = '\0';
4959 ch = i_getch(input); /* eat it */
4960 continue; /* back to top of while (1) */
4965 if (dest.o_assignment == MAYBE_ASSIGNMENT
4966 /* check that we are not in word in "a=1 2>word b=1": */
4967 && !ctx.pending_redirect
4969 /* ch is a special char and thus this word
4970 * cannot be an assignment */
4971 dest.o_assignment = NOT_ASSIGNMENT;
4972 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4975 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4978 case '#': /* non-comment #: "echo a#b" etc */
4979 o_addQchr(&dest, ch);
4983 syntax_error("\\<eof>");
4986 ch = i_getch(input);
4987 /* note: ch != '\n' (that case does not reach this place) */
4988 o_addchr(&dest, '\\');
4989 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4990 o_addchr(&dest, ch);
4991 nommu_addchr(&ctx.as_string, ch);
4992 /* Example: echo Hello \2>file
4993 * we need to know that word 2 is quoted */
4994 dest.has_quoted_part = 1;
4997 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4998 debug_printf_parse("parse_stream parse error: "
4999 "parse_dollar returned 0 (error)\n");
5004 dest.has_quoted_part = 1;
5005 if (next == '\'' && !ctx.pending_redirect) {
5006 insert_empty_quoted_str_marker:
5007 nommu_addchr(&ctx.as_string, next);
5008 i_getch(input); /* eat second ' */
5009 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5010 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5013 ch = i_getch(input);
5015 syntax_error_unterm_ch('\'');
5018 nommu_addchr(&ctx.as_string, ch);
5021 o_addqchr(&dest, ch);
5026 dest.has_quoted_part = 1;
5027 if (next == '"' && !ctx.pending_redirect)
5028 goto insert_empty_quoted_str_marker;
5029 if (dest.o_assignment == NOT_ASSIGNMENT)
5030 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5031 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5033 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5035 #if ENABLE_HUSH_TICK
5037 USE_FOR_NOMMU(unsigned pos;)
5039 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5040 o_addchr(&dest, '`');
5041 USE_FOR_NOMMU(pos = dest.length;)
5042 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5045 o_addstr(&ctx.as_string, dest.data + pos);
5046 o_addchr(&ctx.as_string, '`');
5048 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5049 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5054 #if ENABLE_HUSH_CASE
5057 if (done_word(&dest, &ctx)) {
5060 done_pipe(&ctx, PIPE_SEQ);
5061 #if ENABLE_HUSH_CASE
5062 /* Eat multiple semicolons, detect
5063 * whether it means something special */
5068 ch = i_getch(input);
5069 nommu_addchr(&ctx.as_string, ch);
5070 if (ctx.ctx_res_w == RES_CASE_BODY) {
5071 ctx.ctx_dsemicolon = 1;
5072 ctx.ctx_res_w = RES_MATCH;
5078 /* We just finished a cmd. New one may start
5079 * with an assignment */
5080 dest.o_assignment = MAYBE_ASSIGNMENT;
5081 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5084 if (done_word(&dest, &ctx)) {
5088 ch = i_getch(input);
5089 nommu_addchr(&ctx.as_string, ch);
5090 done_pipe(&ctx, PIPE_AND);
5092 done_pipe(&ctx, PIPE_BG);
5096 if (done_word(&dest, &ctx)) {
5099 #if ENABLE_HUSH_CASE
5100 if (ctx.ctx_res_w == RES_MATCH)
5101 break; /* we are in case's "word | word)" */
5103 if (next == '|') { /* || */
5104 ch = i_getch(input);
5105 nommu_addchr(&ctx.as_string, ch);
5106 done_pipe(&ctx, PIPE_OR);
5108 /* we could pick up a file descriptor choice here
5109 * with redirect_opt_num(), but bash doesn't do it.
5110 * "echo foo 2| cat" yields "foo 2". */
5115 #if ENABLE_HUSH_CASE
5116 /* "case... in [(]word)..." - skip '(' */
5117 if (ctx.ctx_res_w == RES_MATCH
5118 && ctx.command->argv == NULL /* not (word|(... */
5119 && dest.length == 0 /* not word(... */
5120 && dest.has_quoted_part == 0 /* not ""(... */
5126 if (parse_group(&dest, &ctx, input, ch) != 0) {
5131 #if ENABLE_HUSH_CASE
5132 if (ctx.ctx_res_w == RES_MATCH)
5136 /* proper use of this character is caught by end_trigger:
5137 * if we see {, we call parse_group(..., end_trigger='}')
5138 * and it will match } earlier (not here). */
5139 syntax_error_unexpected_ch(ch);
5140 G.last_exitcode = 2;
5144 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5149 G.last_exitcode = 1;
5152 struct parse_context *pctx;
5153 IF_HAS_KEYWORDS(struct parse_context *p2;)
5155 /* Clean up allocated tree.
5156 * Sample for finding leaks on syntax error recovery path.
5157 * Run it from interactive shell, watch pmap `pidof hush`.
5158 * while if false; then false; fi; do break; fi
5159 * Samples to catch leaks at execution:
5160 * while if (true | { true;}); then echo ok; fi; do break; done
5161 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5165 /* Update pipe/command counts,
5166 * otherwise freeing may miss some */
5167 done_pipe(pctx, PIPE_SEQ);
5168 debug_printf_clean("freeing list %p from ctx %p\n",
5169 pctx->list_head, pctx);
5170 debug_print_tree(pctx->list_head, 0);
5171 free_pipe_list(pctx->list_head);
5172 debug_printf_clean("freed list %p\n", pctx->list_head);
5174 o_free_unsafe(&pctx->as_string);
5176 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5180 IF_HAS_KEYWORDS(pctx = p2;)
5181 } while (HAS_KEYWORDS && pctx);
5194 /*** Execution routines ***/
5196 /* Expansion can recurse, need forward decls: */
5197 #if !BASH_PATTERN_SUBST
5198 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5199 #define expand_string_to_string(str, do_unbackslash) \
5200 expand_string_to_string(str)
5202 static char *expand_string_to_string(const char *str, int do_unbackslash);
5203 #if ENABLE_HUSH_TICK
5204 static int process_command_subs(o_string *dest, const char *s);
5207 /* expand_strvec_to_strvec() takes a list of strings, expands
5208 * all variable references within and returns a pointer to
5209 * a list of expanded strings, possibly with larger number
5210 * of strings. (Think VAR="a b"; echo $VAR).
5211 * This new list is allocated as a single malloc block.
5212 * NULL-terminated list of char* pointers is at the beginning of it,
5213 * followed by strings themselves.
5214 * Caller can deallocate entire list by single free(list). */
5216 /* A horde of its helpers come first: */
5218 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5220 while (--len >= 0) {
5223 #if ENABLE_HUSH_BRACE_EXPANSION
5224 if (c == '{' || c == '}') {
5225 /* { -> \{, } -> \} */
5227 /* And now we want to add { or } and continue:
5230 * luckily, just falling through achieves this.
5236 /* \z -> \\\z; \<eol> -> \\<eol> */
5241 o_addchr(o, *str++);
5247 /* Store given string, finalizing the word and starting new one whenever
5248 * we encounter IFS char(s). This is used for expanding variable values.
5249 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5250 * Return in *ended_with_ifs:
5251 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5253 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5255 int last_is_ifs = 0;
5260 if (!*str) /* EOL - do not finalize word */
5262 word_len = strcspn(str, G.ifs);
5264 /* We have WORD_LEN leading non-IFS chars */
5265 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5266 o_addblock(output, str, word_len);
5268 /* Protect backslashes against globbing up :)
5269 * Example: "v='\*'; echo b$v" prints "b\*"
5270 * (and does not try to glob on "*")
5272 o_addblock_duplicate_backslash(output, str, word_len);
5273 /*/ Why can't we do it easier? */
5274 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5275 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5279 if (!*str) /* EOL - do not finalize word */
5283 /* We know str here points to at least one IFS char */
5285 str += strspn(str, G.ifs); /* skip IFS chars */
5286 if (!*str) /* EOL - do not finalize word */
5289 /* Start new word... but not always! */
5290 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5291 if (output->has_quoted_part
5292 /* Case "v=' a'; echo $v":
5293 * here nothing precedes the space in $v expansion,
5294 * therefore we should not finish the word
5295 * (IOW: if there *is* word to finalize, only then do it):
5297 || (n > 0 && output->data[output->length - 1])
5299 o_addchr(output, '\0');
5300 debug_print_list("expand_on_ifs", output, n);
5301 n = o_save_ptr(output, n);
5306 *ended_with_ifs = last_is_ifs;
5307 debug_print_list("expand_on_ifs[1]", output, n);
5311 /* Helper to expand $((...)) and heredoc body. These act as if
5312 * they are in double quotes, with the exception that they are not :).
5313 * Just the rules are similar: "expand only $var and `cmd`"
5315 * Returns malloced string.
5316 * As an optimization, we return NULL if expansion is not needed.
5318 #if !BASH_PATTERN_SUBST
5319 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5320 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5321 encode_then_expand_string(str)
5323 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5326 struct in_str input;
5327 o_string dest = NULL_O_STRING;
5329 if (!strchr(str, '$')
5330 && !strchr(str, '\\')
5331 #if ENABLE_HUSH_TICK
5332 && !strchr(str, '`')
5338 /* We need to expand. Example:
5339 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5341 setup_string_in_str(&input, str);
5342 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5343 //TODO: error check (encode_string returns 0 on error)?
5344 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5345 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5346 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5347 o_free_unsafe(&dest);
5351 #if ENABLE_FEATURE_SH_MATH
5352 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5354 arith_state_t math_state;
5358 math_state.lookupvar = get_local_var_value;
5359 math_state.setvar = set_local_var_from_halves;
5360 //math_state.endofname = endofname;
5361 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5362 res = arith(&math_state, exp_str ? exp_str : arg);
5365 *errmsg_p = math_state.errmsg;
5366 if (math_state.errmsg)
5367 die_if_script(math_state.errmsg);
5372 #if BASH_PATTERN_SUBST
5373 /* ${var/[/]pattern[/repl]} helpers */
5374 static char *strstr_pattern(char *val, const char *pattern, int *size)
5377 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5378 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5385 /* Optimization: if "*pat" did not match the start of "string",
5386 * we know that "tring", "ring" etc will not match too:
5388 if (pattern[0] == '*')
5393 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5395 char *result = NULL;
5396 unsigned res_len = 0;
5397 unsigned repl_len = strlen(repl);
5401 char *s = strstr_pattern(val, pattern, &size);
5405 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5406 memcpy(result + res_len, val, s - val);
5408 strcpy(result + res_len, repl);
5409 res_len += repl_len;
5410 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5416 if (val[0] && result) {
5417 result = xrealloc(result, res_len + strlen(val) + 1);
5418 strcpy(result + res_len, val);
5419 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5421 debug_printf_varexp("result:'%s'\n", result);
5424 #endif /* BASH_PATTERN_SUBST */
5427 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5429 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5431 const char *val = NULL;
5432 char *to_be_freed = NULL;
5437 char exp_save = exp_save; /* for compiler */
5438 char *exp_saveptr; /* points to expansion operator */
5439 char *exp_word = exp_word; /* for compiler */
5442 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5444 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5446 first_char = arg[0] = arg0 & 0x7f;
5449 if (first_char == '#' /* ${#... */
5450 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5452 /* It must be length operator: ${#var} */
5456 /* Maybe handle parameter expansion */
5457 if (exp_saveptr /* if 2nd char is one of expansion operators */
5458 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5460 /* ${?:0}, ${#[:]%0} etc */
5461 exp_saveptr = var + 1;
5463 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5464 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5466 exp_op = exp_save = *exp_saveptr;
5468 exp_word = exp_saveptr + 1;
5469 if (exp_op == ':') {
5470 exp_op = *exp_word++;
5471 //TODO: try ${var:} and ${var:bogus} in non-bash config
5473 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5475 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5480 *exp_saveptr = '\0';
5481 } /* else: it's not an expansion op, but bare ${var} */
5484 /* Look up the variable in question */
5485 if (isdigit(var[0])) {
5486 /* parse_dollar should have vetted var for us */
5487 int n = xatoi_positive(var);
5488 if (n < G.global_argc)
5489 val = G.global_argv[n];
5490 /* else val remains NULL: $N with too big N */
5494 val = utoa(G.root_pid);
5496 case '!': /* bg pid */
5497 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5499 case '?': /* exitcode */
5500 val = utoa(G.last_exitcode);
5502 case '#': /* argc */
5503 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5506 val = get_local_var_value(var);
5510 /* Handle any expansions */
5511 if (exp_op == 'L') {
5512 reinit_unicode_for_hush();
5513 debug_printf_expand("expand: length(%s)=", val);
5514 val = utoa(val ? unicode_strlen(val) : 0);
5515 debug_printf_expand("%s\n", val);
5516 } else if (exp_op) {
5517 if (exp_op == '%' || exp_op == '#') {
5518 /* Standard-mandated substring removal ops:
5519 * ${parameter%word} - remove smallest suffix pattern
5520 * ${parameter%%word} - remove largest suffix pattern
5521 * ${parameter#word} - remove smallest prefix pattern
5522 * ${parameter##word} - remove largest prefix pattern
5524 * Word is expanded to produce a glob pattern.
5525 * Then var's value is matched to it and matching part removed.
5527 if (val && val[0]) {
5531 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5532 if (exp_op == *exp_word) /* ## or %% */
5534 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5536 exp_word = exp_exp_word;
5537 /* HACK ALERT. We depend here on the fact that
5538 * G.global_argv and results of utoa and get_local_var_value
5539 * are actually in writable memory:
5540 * scan_and_match momentarily stores NULs there. */
5542 loc = scan_and_match(t, exp_word, scan_flags);
5543 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5544 // exp_op, t, exp_word, loc);
5546 if (loc) { /* match was found */
5547 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5548 val = loc; /* take right part */
5550 val = to_be_freed = xstrndup(val, loc - val); /* left */
5554 #if BASH_PATTERN_SUBST
5555 else if (exp_op == '/' || exp_op == '\\') {
5556 /* It's ${var/[/]pattern[/repl]} thing.
5557 * Note that in encoded form it has TWO parts:
5558 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5559 * and if // is used, it is encoded as \:
5560 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5562 /* Empty variable always gives nothing: */
5563 // "v=''; echo ${v/*/w}" prints "", not "w"
5564 if (val && val[0]) {
5565 /* pattern uses non-standard expansion.
5566 * repl should be unbackslashed and globbed
5567 * by the usual expansion rules:
5569 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5570 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5571 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5572 * v='a bz'; echo ${v/a*z/\z} prints "z"
5573 * (note that a*z _pattern_ is never globbed!)
5575 char *pattern, *repl, *t;
5576 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5578 pattern = xstrdup(exp_word);
5579 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5580 *p++ = SPECIAL_VAR_SYMBOL;
5582 p = strchr(p, SPECIAL_VAR_SYMBOL);
5584 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5585 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5586 /* HACK ALERT. We depend here on the fact that
5587 * G.global_argv and results of utoa and get_local_var_value
5588 * are actually in writable memory:
5589 * replace_pattern momentarily stores NULs there. */
5591 to_be_freed = replace_pattern(t,
5593 (repl ? repl : exp_word),
5595 if (to_be_freed) /* at least one replace happened */
5601 #endif /* BASH_PATTERN_SUBST */
5602 else if (exp_op == ':') {
5603 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5604 /* It's ${var:N[:M]} bashism.
5605 * Note that in encoded form it has TWO parts:
5606 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5611 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5614 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5615 *p++ = SPECIAL_VAR_SYMBOL;
5617 p = strchr(p, SPECIAL_VAR_SYMBOL);
5619 len = expand_and_evaluate_arith(exp_word, &errmsg);
5622 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5623 if (len >= 0) { /* bash compat: len < 0 is illegal */
5624 if (beg < 0) /* bash compat */
5626 debug_printf_varexp("from val:'%s'\n", val);
5627 if (len == 0 || !val || beg >= strlen(val)) {
5631 /* Paranoia. What if user entered 9999999999999
5632 * which fits in arith_t but not int? */
5635 val = to_be_freed = xstrndup(val + beg, len);
5637 debug_printf_varexp("val:'%s'\n", val);
5639 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5641 die_if_script("malformed ${%s:...}", var);
5644 } else { /* one of "-=+?" */
5645 /* Standard-mandated substitution ops:
5646 * ${var?word} - indicate error if unset
5647 * If var is unset, word (or a message indicating it is unset
5648 * if word is null) is written to standard error
5649 * and the shell exits with a non-zero exit status.
5650 * Otherwise, the value of var is substituted.
5651 * ${var-word} - use default value
5652 * If var is unset, word is substituted.
5653 * ${var=word} - assign and use default value
5654 * If var is unset, word is assigned to var.
5655 * In all cases, final value of var is substituted.
5656 * ${var+word} - use alternative value
5657 * If var is unset, null is substituted.
5658 * Otherwise, word is substituted.
5660 * Word is subjected to tilde expansion, parameter expansion,
5661 * command substitution, and arithmetic expansion.
5662 * If word is not needed, it is not expanded.
5664 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5665 * but also treat null var as if it is unset.
5667 int use_word = (!val || ((exp_save == ':') && !val[0]));
5669 use_word = !use_word;
5670 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5671 (exp_save == ':') ? "true" : "false", use_word);
5673 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5675 exp_word = to_be_freed;
5676 if (exp_op == '?') {
5677 /* mimic bash message */
5678 die_if_script("%s: %s",
5680 exp_word[0] ? exp_word : "parameter null or not set"
5682 //TODO: how interactive bash aborts expansion mid-command?
5687 if (exp_op == '=') {
5688 /* ${var=[word]} or ${var:=[word]} */
5689 if (isdigit(var[0]) || var[0] == '#') {
5690 /* mimic bash message */
5691 die_if_script("$%s: cannot assign in this way", var);
5694 char *new_var = xasprintf("%s=%s", var, val);
5695 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5699 } /* one of "-=+?" */
5701 *exp_saveptr = exp_save;
5707 *to_be_freed_pp = to_be_freed;
5711 /* Expand all variable references in given string, adding words to list[]
5712 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5713 * to be filled). This routine is extremely tricky: has to deal with
5714 * variables/parameters with whitespace, $* and $@, and constructs like
5715 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5716 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5718 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5719 * expansion of right-hand side of assignment == 1-element expand.
5721 char cant_be_null = 0; /* only bit 0x80 matters */
5722 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5725 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5726 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5727 debug_print_list("expand_vars_to_list", output, n);
5728 n = o_save_ptr(output, n);
5729 debug_print_list("expand_vars_to_list[0]", output, n);
5731 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5733 char *to_be_freed = NULL;
5734 const char *val = NULL;
5735 #if ENABLE_HUSH_TICK
5736 o_string subst_result = NULL_O_STRING;
5738 #if ENABLE_FEATURE_SH_MATH
5739 char arith_buf[sizeof(arith_t)*3 + 2];
5743 o_addchr(output, '\0');
5744 n = o_save_ptr(output, n);
5748 o_addblock(output, arg, p - arg);
5749 debug_print_list("expand_vars_to_list[1]", output, n);
5751 p = strchr(p, SPECIAL_VAR_SYMBOL);
5753 /* Fetch special var name (if it is indeed one of them)
5754 * and quote bit, force the bit on if singleword expansion -
5755 * important for not getting v=$@ expand to many words. */
5756 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5758 /* Is this variable quoted and thus expansion can't be null?
5759 * "$@" is special. Even if quoted, it can still
5760 * expand to nothing (not even an empty string),
5761 * thus it is excluded. */
5762 if ((first_ch & 0x7f) != '@')
5763 cant_be_null |= first_ch;
5765 switch (first_ch & 0x7f) {
5766 /* Highest bit in first_ch indicates that var is double-quoted */
5770 if (!G.global_argv[1])
5773 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5774 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5775 while (G.global_argv[i]) {
5776 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5777 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5778 if (G.global_argv[i++][0] && G.global_argv[i]) {
5779 /* this argv[] is not empty and not last:
5780 * put terminating NUL, start new word */
5781 o_addchr(output, '\0');
5782 debug_print_list("expand_vars_to_list[2]", output, n);
5783 n = o_save_ptr(output, n);
5784 debug_print_list("expand_vars_to_list[3]", output, n);
5788 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5789 * and in this case should treat it like '$*' - see 'else...' below */
5790 if (first_ch == ('@'|0x80) /* quoted $@ */
5791 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5794 o_addQstr(output, G.global_argv[i]);
5795 if (++i >= G.global_argc)
5797 o_addchr(output, '\0');
5798 debug_print_list("expand_vars_to_list[4]", output, n);
5799 n = o_save_ptr(output, n);
5801 } else { /* quoted $* (or v="$@" case): add as one word */
5803 o_addQstr(output, G.global_argv[i]);
5804 if (!G.global_argv[++i])
5807 o_addchr(output, G.ifs[0]);
5809 output->has_quoted_part = 1;
5813 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5814 /* "Empty variable", used to make "" etc to not disappear */
5815 output->has_quoted_part = 1;
5817 cant_be_null = 0x80;
5819 #if ENABLE_HUSH_TICK
5820 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5821 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5823 /* Can't just stuff it into output o_string,
5824 * expanded result may need to be globbed
5826 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5827 G.last_exitcode = process_command_subs(&subst_result, arg);
5828 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5829 val = subst_result.data;
5832 #if ENABLE_FEATURE_SH_MATH
5833 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5836 arg++; /* skip '+' */
5837 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5838 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5839 res = expand_and_evaluate_arith(arg, NULL);
5840 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5841 sprintf(arith_buf, ARITH_FMT, res);
5847 val = expand_one_var(&to_be_freed, arg, &p);
5848 IF_HUSH_TICK(store_val:)
5849 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5850 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5851 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5852 if (val && val[0]) {
5853 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5856 } else { /* quoted $VAR, val will be appended below */
5857 output->has_quoted_part = 1;
5858 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5859 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5862 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5864 if (val && val[0]) {
5865 o_addQstr(output, val);
5869 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5870 * Do the check to avoid writing to a const string. */
5871 if (*p != SPECIAL_VAR_SYMBOL)
5872 *p = SPECIAL_VAR_SYMBOL;
5874 #if ENABLE_HUSH_TICK
5875 o_free(&subst_result);
5878 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5882 o_addchr(output, '\0');
5883 n = o_save_ptr(output, n);
5885 debug_print_list("expand_vars_to_list[a]", output, n);
5886 /* this part is literal, and it was already pre-quoted
5887 * if needed (much earlier), do not use o_addQstr here! */
5888 o_addstr_with_NUL(output, arg);
5889 debug_print_list("expand_vars_to_list[b]", output, n);
5890 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5891 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5894 /* allow to reuse list[n] later without re-growth */
5895 output->has_empty_slot = 1;
5897 o_addchr(output, '\0');
5903 static char **expand_variables(char **argv, unsigned expflags)
5907 o_string output = NULL_O_STRING;
5909 output.o_expflags = expflags;
5913 n = expand_vars_to_list(&output, n, *argv);
5916 debug_print_list("expand_variables", &output, n);
5918 /* output.data (malloced in one block) gets returned in "list" */
5919 list = o_finalize_list(&output, n);
5920 debug_print_strings("expand_variables[1]", list);
5924 static char **expand_strvec_to_strvec(char **argv)
5926 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5930 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5932 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5936 /* Used for expansion of right hand of assignments,
5937 * $((...)), heredocs, variable espansion parts.
5939 * NB: should NOT do globbing!
5940 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5942 static char *expand_string_to_string(const char *str, int do_unbackslash)
5944 #if !BASH_PATTERN_SUBST
5945 const int do_unbackslash = 1;
5947 char *argv[2], **list;
5949 debug_printf_expand("string_to_string<='%s'\n", str);
5950 /* This is generally an optimization, but it also
5951 * handles "", which otherwise trips over !list[0] check below.
5952 * (is this ever happens that we actually get str="" here?)
5954 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5955 //TODO: Can use on strings with \ too, just unbackslash() them?
5956 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5957 return xstrdup(str);
5960 argv[0] = (char*)str;
5962 list = expand_variables(argv, do_unbackslash
5963 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5964 : EXP_FLAG_SINGLEWORD
5967 if (!list[0] || list[1])
5968 bb_error_msg_and_die("BUG in varexp2");
5969 /* actually, just move string 2*sizeof(char*) bytes back */
5970 overlapping_strcpy((char*)list, list[0]);
5972 unbackslash((char*)list);
5973 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5977 /* Used for "eval" builtin */
5978 static char* expand_strvec_to_string(char **argv)
5982 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5983 /* Convert all NULs to spaces */
5988 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5989 bb_error_msg_and_die("BUG in varexp3");
5990 /* bash uses ' ' regardless of $IFS contents */
5995 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5996 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6000 static char **expand_assignments(char **argv, int count)
6005 G.expanded_assignments = p = NULL;
6006 /* Expand assignments into one string each */
6007 for (i = 0; i < count; i++) {
6008 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6010 G.expanded_assignments = NULL;
6015 static void switch_off_special_sigs(unsigned mask)
6018 while ((mask >>= 1) != 0) {
6022 #if ENABLE_HUSH_TRAP
6024 if (G_traps[sig] && !G_traps[sig][0])
6025 /* trap is '', has to remain SIG_IGN */
6028 G_traps[sig] = NULL;
6031 /* We are here only if no trap or trap was not '' */
6032 install_sighandler(sig, SIG_DFL);
6038 void re_execute_shell(char ***to_free, const char *s,
6039 char *g_argv0, char **g_argv,
6040 char **builtin_argv) NORETURN;
6042 static void reset_traps_to_defaults(void)
6044 /* This function is always called in a child shell
6045 * after fork (not vfork, NOMMU doesn't use this function).
6047 IF_HUSH_TRAP(unsigned sig;)
6050 /* Child shells are not interactive.
6051 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6052 * Testcase: (while :; do :; done) + ^Z should background.
6053 * Same goes for SIGTERM, SIGHUP, SIGINT.
6055 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6056 if (!G_traps && !mask)
6057 return; /* already no traps and no special sigs */
6059 /* Switch off special sigs */
6060 switch_off_special_sigs(mask);
6061 # if ENABLE_HUSH_JOB
6062 G_fatal_sig_mask = 0;
6064 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6065 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6066 * remain set in G.special_sig_mask */
6068 # if ENABLE_HUSH_TRAP
6072 /* Reset all sigs to default except ones with empty traps */
6073 for (sig = 0; sig < NSIG; sig++) {
6075 continue; /* no trap: nothing to do */
6076 if (!G_traps[sig][0])
6077 continue; /* empty trap: has to remain SIG_IGN */
6078 /* sig has non-empty trap, reset it: */
6080 G_traps[sig] = NULL;
6081 /* There is no signal for trap 0 (EXIT) */
6084 install_sighandler(sig, pick_sighandler(sig));
6091 static void re_execute_shell(char ***to_free, const char *s,
6092 char *g_argv0, char **g_argv,
6093 char **builtin_argv) NORETURN;
6094 static void re_execute_shell(char ***to_free, const char *s,
6095 char *g_argv0, char **g_argv,
6096 char **builtin_argv)
6098 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6099 /* delims + 2 * (number of bytes in printed hex numbers) */
6100 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6101 char *heredoc_argv[4];
6102 struct variable *cur;
6103 # if ENABLE_HUSH_FUNCTIONS
6104 struct function *funcp;
6108 unsigned long long empty_trap_mask;
6110 if (!g_argv0) { /* heredoc */
6111 argv = heredoc_argv;
6112 argv[0] = (char *) G.argv0_for_re_execing;
6113 argv[1] = (char *) "-<";
6114 argv[2] = (char *) s;
6116 pp = &argv[3]; /* used as pointer to empty environment */
6122 if (pp) while (*pp++)
6125 empty_trap_mask = 0;
6128 for (sig = 1; sig < NSIG; sig++) {
6129 if (G_traps[sig] && !G_traps[sig][0])
6130 empty_trap_mask |= 1LL << sig;
6134 sprintf(param_buf, NOMMU_HACK_FMT
6135 , (unsigned) G.root_pid
6136 , (unsigned) G.root_ppid
6137 , (unsigned) G.last_bg_pid
6138 , (unsigned) G.last_exitcode
6141 IF_HUSH_LOOPS(, G.depth_of_loop)
6143 # undef NOMMU_HACK_FMT
6144 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6145 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6148 for (cur = G.top_var; cur; cur = cur->next) {
6149 if (!cur->flg_export || cur->flg_read_only)
6152 # if ENABLE_HUSH_FUNCTIONS
6153 for (funcp = G.top_func; funcp; funcp = funcp->next)
6159 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6160 *pp++ = (char *) G.argv0_for_re_execing;
6162 for (cur = G.top_var; cur; cur = cur->next) {
6163 if (strcmp(cur->varstr, hush_version_str) == 0)
6165 if (cur->flg_read_only) {
6166 *pp++ = (char *) "-R";
6167 *pp++ = cur->varstr;
6168 } else if (!cur->flg_export) {
6169 *pp++ = (char *) "-V";
6170 *pp++ = cur->varstr;
6173 # if ENABLE_HUSH_FUNCTIONS
6174 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6175 *pp++ = (char *) "-F";
6176 *pp++ = funcp->name;
6177 *pp++ = funcp->body_as_string;
6180 /* We can pass activated traps here. Say, -Tnn:trap_string
6182 * However, POSIX says that subshells reset signals with traps
6184 * I tested bash-3.2 and it not only does that with true subshells
6185 * of the form ( list ), but with any forked children shells.
6186 * I set trap "echo W" WINCH; and then tried:
6188 * { echo 1; sleep 20; echo 2; } &
6189 * while true; do echo 1; sleep 20; echo 2; break; done &
6190 * true | { echo 1; sleep 20; echo 2; } | cat
6192 * In all these cases sending SIGWINCH to the child shell
6193 * did not run the trap. If I add trap "echo V" WINCH;
6194 * _inside_ group (just before echo 1), it works.
6196 * I conclude it means we don't need to pass active traps here.
6198 *pp++ = (char *) "-c";
6201 while (*++builtin_argv)
6202 *pp++ = *builtin_argv;
6203 *pp++ = (char *) "";
6208 /* *pp = NULL; - is already there */
6212 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6213 /* Don't propagate SIG_IGN to the child */
6214 if (SPECIAL_JOBSTOP_SIGS != 0)
6215 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6216 execve(bb_busybox_exec_path, argv, pp);
6217 /* Fallback. Useful for init=/bin/hush usage etc */
6218 if (argv[0][0] == '/')
6219 execve(argv[0], argv, pp);
6220 xfunc_error_retval = 127;
6221 bb_error_msg_and_die("can't re-execute the shell");
6223 #endif /* !BB_MMU */
6226 static int run_and_free_list(struct pipe *pi);
6228 /* Executing from string: eval, sh -c '...'
6229 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6230 * end_trigger controls how often we stop parsing
6231 * NUL: parse all, execute, return
6232 * ';': parse till ';' or newline, execute, repeat till EOF
6234 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6236 /* Why we need empty flag?
6237 * An obscure corner case "false; ``; echo $?":
6238 * empty command in `` should still set $? to 0.
6239 * But we can't just set $? to 0 at the start,
6240 * this breaks "false; echo `echo $?`" case.
6244 struct pipe *pipe_list;
6246 #if ENABLE_HUSH_INTERACTIVE
6247 if (end_trigger == ';')
6248 inp->promptmode = 0; /* PS1 */
6250 pipe_list = parse_stream(NULL, inp, end_trigger);
6251 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6252 /* If we are in "big" script
6253 * (not in `cmd` or something similar)...
6255 if (pipe_list == ERR_PTR && end_trigger == ';') {
6256 /* Discard cached input (rest of line) */
6257 int ch = inp->last_char;
6258 while (ch != EOF && ch != '\n') {
6259 //bb_error_msg("Discarded:'%c'", ch);
6264 /* This stream isn't empty */
6268 if (!pipe_list && empty)
6269 G.last_exitcode = 0;
6272 debug_print_tree(pipe_list, 0);
6273 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6274 run_and_free_list(pipe_list);
6276 if (G_flag_return_in_progress == 1)
6281 static void parse_and_run_string(const char *s)
6283 struct in_str input;
6284 setup_string_in_str(&input, s);
6285 parse_and_run_stream(&input, '\0');
6288 static void parse_and_run_file(FILE *f)
6290 struct in_str input;
6291 setup_file_in_str(&input, f);
6292 parse_and_run_stream(&input, ';');
6295 #if ENABLE_HUSH_TICK
6296 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6301 char **to_free = NULL;
6305 pid = BB_MMU ? xfork() : xvfork();
6306 if (pid == 0) { /* child */
6307 disable_restore_tty_pgrp_on_exit();
6308 /* Process substitution is not considered to be usual
6309 * 'command execution'.
6310 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6317 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6318 close(channel[0]); /* NB: close _first_, then move fd! */
6319 xmove_fd(channel[1], 1);
6320 /* Prevent it from trying to handle ctrl-z etc */
6321 IF_HUSH_JOB(G.run_list_level = 1;)
6322 # if ENABLE_HUSH_TRAP
6323 /* Awful hack for `trap` or $(trap).
6325 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6326 * contains an example where "trap" is executed in a subshell:
6328 * save_traps=$(trap)
6330 * eval "$save_traps"
6332 * Standard does not say that "trap" in subshell shall print
6333 * parent shell's traps. It only says that its output
6334 * must have suitable form, but then, in the above example
6335 * (which is not supposed to be normative), it implies that.
6337 * bash (and probably other shell) does implement it
6338 * (traps are reset to defaults, but "trap" still shows them),
6339 * but as a result, "trap" logic is hopelessly messed up:
6342 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6343 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6344 * # true | trap <--- trap is in subshell - no output (ditto)
6345 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6346 * trap -- 'echo Ho' SIGWINCH
6347 * # echo `(trap)` <--- in subshell in subshell - output
6348 * trap -- 'echo Ho' SIGWINCH
6349 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6350 * trap -- 'echo Ho' SIGWINCH
6352 * The rules when to forget and when to not forget traps
6353 * get really complex and nonsensical.
6355 * Our solution: ONLY bare $(trap) or `trap` is special.
6357 s = skip_whitespace(s);
6358 if (is_prefixed_with(s, "trap")
6359 && skip_whitespace(s + 4)[0] == '\0'
6361 static const char *const argv[] = { NULL, NULL };
6362 builtin_trap((char**)argv);
6363 fflush_all(); /* important */
6368 reset_traps_to_defaults();
6369 parse_and_run_string(s);
6370 _exit(G.last_exitcode);
6372 /* We re-execute after vfork on NOMMU. This makes this script safe:
6373 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6374 * huge=`cat BIG` # was blocking here forever
6377 re_execute_shell(&to_free,
6387 # if ENABLE_HUSH_FAST
6389 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6390 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6391 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6393 enable_restore_tty_pgrp_on_exit();
6398 return remember_FILE(xfdopen_for_read(channel[0]));
6401 /* Return code is exit status of the process that is run. */
6402 static int process_command_subs(o_string *dest, const char *s)
6405 struct in_str pipe_str;
6407 int status, ch, eol_cnt;
6409 fp = generate_stream_from_string(s, &pid);
6411 /* Now send results of command back into original context */
6412 setup_file_in_str(&pipe_str, fp);
6414 while ((ch = i_getch(&pipe_str)) != EOF) {
6420 o_addchr(dest, '\n');
6423 o_addQchr(dest, ch);
6426 debug_printf("done reading from `cmd` pipe, closing it\n");
6427 fclose_and_forget(fp);
6428 /* We need to extract exitcode. Test case
6429 * "true; echo `sleep 1; false` $?"
6431 safe_waitpid(pid, &status, 0);
6432 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6433 return WEXITSTATUS(status);
6435 #endif /* ENABLE_HUSH_TICK */
6438 static void setup_heredoc(struct redir_struct *redir)
6440 struct fd_pair pair;
6443 /* the _body_ of heredoc (misleading field name) */
6444 const char *heredoc = redir->rd_filename;
6451 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6452 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6456 len = strlen(heredoc);
6458 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6460 xmove_fd(pair.rd, redir->rd_fd);
6462 /* Try writing without forking. Newer kernels have
6463 * dynamically growing pipes. Must use non-blocking write! */
6466 written = write(pair.wr, heredoc, len);
6477 ndelay_off(pair.wr);
6479 /* Okay, pipe buffer was not big enough */
6480 /* Note: we must not create a stray child (bastard? :)
6481 * for the unsuspecting parent process. Child creates a grandchild
6482 * and exits before parent execs the process which consumes heredoc
6483 * (that exec happens after we return from this function) */
6490 disable_restore_tty_pgrp_on_exit();
6491 pid = BB_MMU ? xfork() : xvfork();
6495 close(redir->rd_fd); /* read side of the pipe */
6497 full_write(pair.wr, heredoc, len); /* may loop or block */
6500 /* Delegate blocking writes to another process */
6501 xmove_fd(pair.wr, STDOUT_FILENO);
6502 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6506 #if ENABLE_HUSH_FAST
6508 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6510 enable_restore_tty_pgrp_on_exit();
6516 wait(NULL); /* wait till child has died */
6519 /* fd: redirect wants this fd to be used (e.g. 3>file).
6520 * Move all conflicting internally used fds,
6521 * and remember them so that we can restore them later.
6523 static int save_fds_on_redirect(int fd, int squirrel[3])
6526 /* Handle redirects of fds 0,1,2 */
6528 /* If we collide with an already moved stdio fd... */
6529 if (fd == squirrel[0]) {
6530 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6533 if (fd == squirrel[1]) {
6534 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6537 if (fd == squirrel[2]) {
6538 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6541 /* If we are about to redirect stdio fd, and did not yet move it... */
6542 if (fd <= 2 && squirrel[fd] < 0) {
6543 /* We avoid taking stdio fds */
6544 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6545 if (squirrel[fd] < 0 && errno != EBADF)
6547 return 0; /* "we did not close fd" */
6551 #if ENABLE_HUSH_INTERACTIVE
6552 if (fd != 0 && fd == G.interactive_fd) {
6553 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6558 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6559 * (1) Redirect in a forked child. No need to save FILEs' fds,
6560 * we aren't going to use them anymore, ok to trash.
6561 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6562 * but how are we doing to use them?
6563 * "fileno(fd) = new_fd" can't be done.
6568 return save_FILEs_on_redirect(fd);
6571 static void restore_redirects(int squirrel[3])
6574 for (i = 0; i <= 2; i++) {
6577 /* We simply die on error */
6582 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6584 restore_redirected_FILEs();
6587 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6588 * and stderr if they are redirected. */
6589 static int setup_redirects(struct command *prog, int squirrel[])
6592 struct redir_struct *redir;
6594 for (redir = prog->redirects; redir; redir = redir->next) {
6595 if (redir->rd_type == REDIRECT_HEREDOC2) {
6596 /* "rd_fd<<HERE" case */
6597 save_fds_on_redirect(redir->rd_fd, squirrel);
6598 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6600 debug_printf_parse("set heredoc '%s'\n",
6601 redir->rd_filename);
6602 setup_heredoc(redir);
6606 if (redir->rd_dup == REDIRFD_TO_FILE) {
6607 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6609 if (redir->rd_filename == NULL) {
6612 * "cmd >" (no filename)
6613 * "cmd > <file" (2nd redirect starts too early)
6615 die_if_script("syntax error: %s", "invalid redirect");
6618 mode = redir_table[redir->rd_type].mode;
6619 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6620 openfd = open_or_warn(p, mode);
6623 /* Error message from open_or_warn can be lost
6624 * if stderr has been redirected, but bash
6625 * and ash both lose it as well
6626 * (though zsh doesn't!)
6631 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6632 openfd = redir->rd_dup;
6635 if (openfd != redir->rd_fd) {
6636 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6637 if (openfd == REDIRFD_CLOSE) {
6638 /* "rd_fd >&-" means "close me" */
6640 /* ^^^ optimization: saving may already
6641 * have closed it. If not... */
6642 close(redir->rd_fd);
6645 xdup2(openfd, redir->rd_fd);
6646 if (redir->rd_dup == REDIRFD_TO_FILE)
6647 /* "rd_fd > FILE" */
6649 /* else: "rd_fd > rd_dup" */
6656 static char *find_in_path(const char *arg)
6659 const char *PATH = get_local_var_value("PATH");
6665 const char *end = strchrnul(PATH, ':');
6666 int sz = end - PATH; /* must be int! */
6670 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6672 /* We have xxx::yyyy in $PATH,
6673 * it means "use current dir" */
6676 if (access(ret, F_OK) == 0)
6689 static const struct built_in_command *find_builtin_helper(const char *name,
6690 const struct built_in_command *x,
6691 const struct built_in_command *end)
6694 if (strcmp(name, x->b_cmd) != 0) {
6698 debug_printf_exec("found builtin '%s'\n", name);
6703 static const struct built_in_command *find_builtin1(const char *name)
6705 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6707 static const struct built_in_command *find_builtin(const char *name)
6709 const struct built_in_command *x = find_builtin1(name);
6712 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6715 #if ENABLE_HUSH_FUNCTIONS
6716 static struct function **find_function_slot(const char *name)
6718 struct function **funcpp = &G.top_func;
6720 if (strcmp(name, (*funcpp)->name) == 0) {
6723 funcpp = &(*funcpp)->next;
6728 static const struct function *find_function(const char *name)
6730 const struct function *funcp = *find_function_slot(name);
6732 debug_printf_exec("found function '%s'\n", name);
6736 /* Note: takes ownership on name ptr */
6737 static struct function *new_function(char *name)
6739 struct function **funcpp = find_function_slot(name);
6740 struct function *funcp = *funcpp;
6742 if (funcp != NULL) {
6743 struct command *cmd = funcp->parent_cmd;
6744 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6746 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6748 /* Note: if !funcp->body, do not free body_as_string!
6749 * This is a special case of "-F name body" function:
6750 * body_as_string was not malloced! */
6752 free_pipe_list(funcp->body);
6754 free(funcp->body_as_string);
6758 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6759 cmd->argv[0] = funcp->name;
6760 cmd->group = funcp->body;
6762 cmd->group_as_string = funcp->body_as_string;
6766 debug_printf_exec("remembering new function '%s'\n", name);
6767 funcp = *funcpp = xzalloc(sizeof(*funcp));
6768 /*funcp->next = NULL;*/
6775 # if ENABLE_HUSH_UNSET
6776 static void unset_func(const char *name)
6778 struct function **funcpp = find_function_slot(name);
6779 struct function *funcp = *funcpp;
6781 if (funcp != NULL) {
6782 debug_printf_exec("freeing function '%s'\n", funcp->name);
6783 *funcpp = funcp->next;
6784 /* funcp is unlinked now, deleting it.
6785 * Note: if !funcp->body, the function was created by
6786 * "-F name body", do not free ->body_as_string
6787 * and ->name as they were not malloced. */
6789 free_pipe_list(funcp->body);
6792 free(funcp->body_as_string);
6801 #define exec_function(to_free, funcp, argv) \
6802 exec_function(funcp, argv)
6804 static void exec_function(char ***to_free,
6805 const struct function *funcp,
6806 char **argv) NORETURN;
6807 static void exec_function(char ***to_free,
6808 const struct function *funcp,
6814 argv[0] = G.global_argv[0];
6815 G.global_argv = argv;
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);
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: */
7726 restore_redirects(squirrel);
7728 free(argv_expanded);
7729 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7731 debug_printf_exec("run_pipe return %d\n", rcode);
7735 if (ENABLE_FEATURE_SH_NOFORK) {
7736 int n = find_applet_by_name(argv_expanded[0]);
7737 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7738 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7740 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7741 argv_expanded[0], argv_expanded[1]);
7742 rcode = run_nofork_applet(n, argv_expanded);
7744 goto clean_up_and_ret;
7747 /* It is neither builtin nor applet. We must fork. */
7751 /* NB: argv_expanded may already be created, and that
7752 * might include `cmd` runs! Do not rerun it! We *must*
7753 * use argv_expanded if it's non-NULL */
7755 /* Going to fork a child per each pipe member */
7760 while (cmd_no < pi->num_cmds) {
7761 struct fd_pair pipefds;
7763 volatile nommu_save_t nommu_save;
7764 nommu_save.new_env = NULL;
7765 nommu_save.old_vars = NULL;
7766 nommu_save.argv = NULL;
7767 nommu_save.argv_from_re_execing = NULL;
7769 command = &pi->cmds[cmd_no];
7771 if (command->argv) {
7772 debug_printf_exec(": pipe member '%s' '%s'...\n",
7773 command->argv[0], command->argv[1]);
7775 debug_printf_exec(": pipe member with no argv\n");
7778 /* pipes are inserted between pairs of commands */
7781 if (cmd_no < pi->num_cmds)
7782 xpiped_pair(pipefds);
7784 command->pid = BB_MMU ? fork() : vfork();
7785 if (!command->pid) { /* child */
7787 disable_restore_tty_pgrp_on_exit();
7788 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7790 /* Every child adds itself to new process group
7791 * with pgid == pid_of_first_child_in_pipe */
7792 if (G.run_list_level == 1 && G_interactive_fd) {
7795 if (pgrp < 0) /* true for 1st process only */
7797 if (setpgid(0, pgrp) == 0
7798 && pi->followup != PIPE_BG
7799 && G_saved_tty_pgrp /* we have ctty */
7801 /* We do it in *every* child, not just first,
7803 tcsetpgrp(G_interactive_fd, pgrp);
7807 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7808 /* 1st cmd in backgrounded pipe
7809 * should have its stdin /dev/null'ed */
7811 if (open(bb_dev_null, O_RDONLY))
7812 xopen("/", O_RDONLY);
7814 xmove_fd(next_infd, 0);
7816 xmove_fd(pipefds.wr, 1);
7819 /* Like bash, explicit redirects override pipes,
7820 * and the pipe fd (fd#1) is available for dup'ing:
7821 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7822 * of cmd1 goes into pipe.
7824 if (setup_redirects(command, NULL)) {
7825 /* Happens when redir file can't be opened:
7826 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7828 * hush: can't open '/qwe/rty': No such file or directory
7830 * (echo BAR is not executed, it hits _exit(1) below)
7835 /* Stores to nommu_save list of env vars putenv'ed
7836 * (NOMMU, on MMU we don't need that) */
7837 /* cast away volatility... */
7838 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7839 /* pseudo_exec() does not return */
7842 /* parent or error */
7843 #if ENABLE_HUSH_FAST
7845 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7847 enable_restore_tty_pgrp_on_exit();
7849 /* Clean up after vforked child */
7850 free(nommu_save.argv);
7851 free(nommu_save.argv_from_re_execing);
7852 unset_vars(nommu_save.new_env);
7853 add_vars(nommu_save.old_vars);
7855 free(argv_expanded);
7856 argv_expanded = NULL;
7857 if (command->pid < 0) { /* [v]fork failed */
7858 /* Clearly indicate, was it fork or vfork */
7859 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7863 /* Second and next children need to know pid of first one */
7865 pi->pgrp = command->pid;
7871 if (cmd_no < pi->num_cmds)
7873 /* Pass read (output) pipe end to next iteration */
7874 next_infd = pipefds.rd;
7877 if (!pi->alive_cmds) {
7879 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7884 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7888 /* NB: called by pseudo_exec, and therefore must not modify any
7889 * global data until exec/_exit (we can be a child after vfork!) */
7890 static int run_list(struct pipe *pi)
7892 #if ENABLE_HUSH_CASE
7893 char *case_word = NULL;
7895 #if ENABLE_HUSH_LOOPS
7896 struct pipe *loop_top = NULL;
7897 char **for_lcur = NULL;
7898 char **for_list = NULL;
7900 smallint last_followup;
7902 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7903 smalluint cond_code = 0;
7905 enum { cond_code = 0 };
7908 smallint rword; /* RES_foo */
7909 smallint last_rword; /* ditto */
7912 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7915 #if ENABLE_HUSH_LOOPS
7916 /* Check syntax for "for" */
7919 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7920 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7922 /* current word is FOR or IN (BOLD in comments below) */
7923 if (cpipe->next == NULL) {
7924 syntax_error("malformed for");
7926 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7929 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7930 if (cpipe->next->res_word == RES_DO)
7932 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7933 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7934 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7936 syntax_error("malformed for");
7938 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7945 /* Past this point, all code paths should jump to ret: label
7946 * in order to return, no direct "return" statements please.
7947 * This helps to ensure that no memory is leaked. */
7955 last_rword = RES_XXXX;
7957 last_followup = PIPE_SEQ;
7958 rcode = G.last_exitcode;
7960 /* Go through list of pipes, (maybe) executing them. */
7961 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7966 if (G_flag_return_in_progress == 1)
7969 IF_HAS_KEYWORDS(rword = pi->res_word;)
7970 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7971 rword, cond_code, last_rword);
7972 #if ENABLE_HUSH_LOOPS
7973 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7974 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7976 /* start of a loop: remember where loop starts */
7981 /* Still in the same "if...", "then..." or "do..." branch? */
7982 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7983 if ((rcode == 0 && last_followup == PIPE_OR)
7984 || (rcode != 0 && last_followup == PIPE_AND)
7986 /* It is "<true> || CMD" or "<false> && CMD"
7987 * and we should not execute CMD */
7988 debug_printf_exec("skipped cmd because of || or &&\n");
7989 last_followup = pi->followup;
7990 goto dont_check_jobs_but_continue;
7993 last_followup = pi->followup;
7994 IF_HAS_KEYWORDS(last_rword = rword;)
7997 if (rword == RES_THEN) {
7998 /* if false; then ... fi has exitcode 0! */
7999 G.last_exitcode = rcode = EXIT_SUCCESS;
8000 /* "if <false> THEN cmd": skip cmd */
8004 if (rword == RES_ELSE || rword == RES_ELIF) {
8005 /* "if <true> then ... ELSE/ELIF cmd":
8006 * skip cmd and all following ones */
8011 #if ENABLE_HUSH_LOOPS
8012 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8014 /* first loop through for */
8016 static const char encoded_dollar_at[] ALIGN1 = {
8017 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8018 }; /* encoded representation of "$@" */
8019 static const char *const encoded_dollar_at_argv[] = {
8020 encoded_dollar_at, NULL
8021 }; /* argv list with one element: "$@" */
8024 vals = (char**)encoded_dollar_at_argv;
8025 if (pi->next->res_word == RES_IN) {
8026 /* if no variable values after "in" we skip "for" */
8027 if (!pi->next->cmds[0].argv) {
8028 G.last_exitcode = rcode = EXIT_SUCCESS;
8029 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8032 vals = pi->next->cmds[0].argv;
8033 } /* else: "for var; do..." -> assume "$@" list */
8034 /* create list of variable values */
8035 debug_print_strings("for_list made from", vals);
8036 for_list = expand_strvec_to_strvec(vals);
8037 for_lcur = for_list;
8038 debug_print_strings("for_list", for_list);
8041 /* "for" loop is over, clean up */
8047 /* Insert next value from for_lcur */
8048 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8049 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8052 if (rword == RES_IN) {
8053 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8055 if (rword == RES_DONE) {
8056 continue; /* "done" has no cmds too */
8059 #if ENABLE_HUSH_CASE
8060 if (rword == RES_CASE) {
8061 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8062 case_word = expand_strvec_to_string(pi->cmds->argv);
8065 if (rword == RES_MATCH) {
8068 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8069 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8071 /* all prev words didn't match, does this one match? */
8072 argv = pi->cmds->argv;
8074 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8075 /* TODO: which FNM_xxx flags to use? */
8076 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8078 if (cond_code == 0) { /* match! we will execute this branch */
8080 case_word = NULL; /* make future "word)" stop */
8087 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8088 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8090 continue; /* not matched yet, skip this pipe */
8092 if (rword == RES_ESAC) {
8093 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8095 /* "case" did not match anything: still set $? (to 0) */
8096 G.last_exitcode = rcode = EXIT_SUCCESS;
8100 /* Just pressing <enter> in shell should check for jobs.
8101 * OTOH, in non-interactive shell this is useless
8102 * and only leads to extra job checks */
8103 if (pi->num_cmds == 0) {
8104 if (G_interactive_fd)
8105 goto check_jobs_and_continue;
8109 /* After analyzing all keywords and conditions, we decided
8110 * to execute this pipe. NB: have to do checkjobs(NULL)
8111 * after run_pipe to collect any background children,
8112 * even if list execution is to be stopped. */
8113 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8114 #if ENABLE_HUSH_LOOPS
8115 G.flag_break_continue = 0;
8117 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8119 /* We ran a builtin, function, or group.
8120 * rcode is already known
8121 * and we don't need to wait for anything. */
8122 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8123 G.last_exitcode = rcode;
8124 check_and_run_traps();
8125 #if ENABLE_HUSH_LOOPS
8126 /* Was it "break" or "continue"? */
8127 if (G.flag_break_continue) {
8128 smallint fbc = G.flag_break_continue;
8129 /* We might fall into outer *loop*,
8130 * don't want to break it too */
8132 G.depth_break_continue--;
8133 if (G.depth_break_continue == 0)
8134 G.flag_break_continue = 0;
8135 /* else: e.g. "continue 2" should *break* once, *then* continue */
8136 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8137 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8138 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8141 /* "continue": simulate end of loop */
8146 if (G_flag_return_in_progress == 1) {
8147 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8150 } else if (pi->followup == PIPE_BG) {
8151 /* What does bash do with attempts to background builtins? */
8152 /* even bash 3.2 doesn't do that well with nested bg:
8153 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8154 * I'm NOT treating inner &'s as jobs */
8156 if (G.run_list_level == 1)
8159 /* Last command's pid goes to $! */
8160 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8161 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8162 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8163 rcode = EXIT_SUCCESS;
8167 if (G.run_list_level == 1 && G_interactive_fd) {
8168 /* Waits for completion, then fg's main shell */
8169 rcode = checkjobs_and_fg_shell(pi);
8170 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8174 /* This one just waits for completion */
8175 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8176 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8178 G.last_exitcode = rcode;
8179 check_and_run_traps();
8182 /* Analyze how result affects subsequent commands */
8184 if (rword == RES_IF || rword == RES_ELIF)
8187 check_jobs_and_continue:
8188 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8189 dont_check_jobs_but_continue: ;
8190 #if ENABLE_HUSH_LOOPS
8191 /* Beware of "while false; true; do ..."! */
8193 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8194 /* check for RES_DONE is needed for "while ...; do \n done" case */
8196 if (rword == RES_WHILE) {
8198 /* "while false; do...done" - exitcode 0 */
8199 G.last_exitcode = rcode = EXIT_SUCCESS;
8200 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8204 if (rword == RES_UNTIL) {
8206 debug_printf_exec(": until expr is true: breaking\n");
8217 #if ENABLE_HUSH_LOOPS
8222 #if ENABLE_HUSH_CASE
8226 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8230 /* Select which version we will use */
8231 static int run_and_free_list(struct pipe *pi)
8234 debug_printf_exec("run_and_free_list entered\n");
8235 if (!G.o_opt[OPT_O_NOEXEC]) {
8236 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8237 rcode = run_list(pi);
8239 /* free_pipe_list has the side effect of clearing memory.
8240 * In the long run that function can be merged with run_list,
8241 * but doing that now would hobble the debugging effort. */
8243 debug_printf_exec("run_and_free_list return %d\n", rcode);
8248 static void install_sighandlers(unsigned mask)
8250 sighandler_t old_handler;
8252 while ((mask >>= 1) != 0) {
8256 old_handler = install_sighandler(sig, pick_sighandler(sig));
8257 /* POSIX allows shell to re-enable SIGCHLD
8258 * even if it was SIG_IGN on entry.
8259 * Therefore we skip IGN check for it:
8263 if (old_handler == SIG_IGN) {
8264 /* oops... restore back to IGN, and record this fact */
8265 install_sighandler(sig, old_handler);
8266 #if ENABLE_HUSH_TRAP
8268 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8270 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8276 /* Called a few times only (or even once if "sh -c") */
8277 static void install_special_sighandlers(void)
8281 /* Which signals are shell-special? */
8282 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8283 if (G_interactive_fd) {
8284 mask |= SPECIAL_INTERACTIVE_SIGS;
8285 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8286 mask |= SPECIAL_JOBSTOP_SIGS;
8288 /* Careful, do not re-install handlers we already installed */
8289 if (G.special_sig_mask != mask) {
8290 unsigned diff = mask & ~G.special_sig_mask;
8291 G.special_sig_mask = mask;
8292 install_sighandlers(diff);
8298 /* Set handlers to restore tty pgrp and exit */
8299 static void install_fatal_sighandlers(void)
8303 /* We will restore tty pgrp on these signals */
8305 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8306 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8307 + (1 << SIGBUS ) * HUSH_DEBUG
8308 + (1 << SIGSEGV) * HUSH_DEBUG
8309 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8311 /* bash 3.2 seems to handle these just like 'fatal' ones */
8314 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8315 * if we aren't interactive... but in this case
8316 * we never want to restore pgrp on exit, and this fn is not called
8318 /*+ (1 << SIGHUP )*/
8319 /*+ (1 << SIGTERM)*/
8320 /*+ (1 << SIGINT )*/
8322 G_fatal_sig_mask = mask;
8324 install_sighandlers(mask);
8328 static int set_mode(int state, char mode, const char *o_opt)
8333 G.o_opt[OPT_O_NOEXEC] = state;
8336 IF_HUSH_MODE_X(G_x_mode = state;)
8340 /* "set -+o" without parameter.
8341 * in bash, set -o produces this output:
8345 * We always use the second form.
8347 const char *p = o_opt_strings;
8350 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8356 idx = index_in_strings(o_opt_strings, o_opt);
8358 G.o_opt[idx] = state;
8362 return EXIT_FAILURE;
8364 return EXIT_SUCCESS;
8367 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8368 int hush_main(int argc, char **argv)
8371 OPT_login = (1 << 0),
8375 unsigned builtin_argc;
8377 struct variable *cur_var;
8378 struct variable *shell_ver;
8381 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8382 G.last_exitcode = EXIT_SUCCESS;
8384 #if ENABLE_HUSH_FAST
8385 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8388 G.argv0_for_re_execing = argv[0];
8390 /* Deal with HUSH_VERSION */
8391 shell_ver = xzalloc(sizeof(*shell_ver));
8392 shell_ver->flg_export = 1;
8393 shell_ver->flg_read_only = 1;
8394 /* Code which handles ${var<op>...} needs writable values for all variables,
8395 * therefore we xstrdup: */
8396 shell_ver->varstr = xstrdup(hush_version_str);
8397 /* Create shell local variables from the values
8398 * currently living in the environment */
8399 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8400 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8401 G.top_var = shell_ver;
8402 cur_var = G.top_var;
8405 char *value = strchr(*e, '=');
8406 if (value) { /* paranoia */
8407 cur_var->next = xzalloc(sizeof(*cur_var));
8408 cur_var = cur_var->next;
8409 cur_var->varstr = *e;
8410 cur_var->max_len = strlen(*e);
8411 cur_var->flg_export = 1;
8415 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8416 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8417 putenv(shell_ver->varstr);
8420 set_pwd_var(/*exp:*/ 1);
8422 #if BASH_HOSTNAME_VAR
8423 /* Set (but not export) HOSTNAME unless already set */
8424 if (!get_local_var_value("HOSTNAME")) {
8427 set_local_var_from_halves("HOSTNAME", uts.nodename);
8429 /* bash also exports SHLVL and _,
8430 * and sets (but doesn't export) the following variables:
8432 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8433 * BASH_VERSION='3.2.0(1)-release'
8435 * MACHTYPE=i386-pc-linux-gnu
8437 * PPID=<NNNNN> - we also do it elsewhere
8448 * PIPESTATUS=([0]="0")
8449 * HISTFILE=/<xxx>/.bash_history
8453 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8455 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8466 #if ENABLE_FEATURE_EDITING
8467 G.line_input_state = new_line_input_t(FOR_SHELL);
8470 /* Initialize some more globals to non-zero values */
8471 cmdedit_update_prompt();
8473 die_func = restore_ttypgrp_and__exit;
8475 /* Shell is non-interactive at first. We need to call
8476 * install_special_sighandlers() if we are going to execute "sh <script>",
8477 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8478 * If we later decide that we are interactive, we run install_special_sighandlers()
8479 * in order to intercept (more) signals.
8483 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8484 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8487 opt = getopt(argc, argv, "+c:xinsl"
8490 # if ENABLE_HUSH_FUNCTIONS
8500 * sh ... -c 'script'
8501 * sh ... -c 'script' ARG0 [ARG1...]
8502 * On NOMMU, if builtin_argc != 0,
8503 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8504 * "" needs to be replaced with NULL
8505 * and BARGV vector fed to builtin function.
8506 * Note: the form without ARG0 never happens:
8507 * sh ... -c 'builtin' BARGV... ""
8510 G.root_pid = getpid();
8511 G.root_ppid = getppid();
8513 G.global_argv = argv + optind;
8514 G.global_argc = argc - optind;
8516 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8517 const struct built_in_command *x;
8519 install_special_sighandlers();
8520 x = find_builtin(optarg);
8521 if (x) { /* paranoia */
8522 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8523 G.global_argv += builtin_argc;
8524 G.global_argv[-1] = NULL; /* replace "" */
8526 G.last_exitcode = x->b_function(argv + optind - 1);
8530 if (!G.global_argv[0]) {
8531 /* -c 'script' (no params): prevent empty $0 */
8532 G.global_argv--; /* points to argv[i] of 'script' */
8533 G.global_argv[0] = argv[0];
8535 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8536 install_special_sighandlers();
8537 parse_and_run_string(optarg);
8540 /* Well, we cannot just declare interactiveness,
8541 * we have to have some stuff (ctty, etc) */
8542 /* G_interactive_fd++; */
8545 /* "-s" means "read from stdin", but this is how we always
8546 * operate, so simply do nothing here. */
8552 case '<': /* "big heredoc" support */
8553 full_write1_str(optarg);
8556 unsigned long long empty_trap_mask;
8558 G.root_pid = bb_strtou(optarg, &optarg, 16);
8560 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8562 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8564 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8566 builtin_argc = bb_strtou(optarg, &optarg, 16);
8568 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8569 if (empty_trap_mask != 0) {
8570 IF_HUSH_TRAP(int sig;)
8571 install_special_sighandlers();
8572 # if ENABLE_HUSH_TRAP
8573 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8574 for (sig = 1; sig < NSIG; sig++) {
8575 if (empty_trap_mask & (1LL << sig)) {
8576 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8577 install_sighandler(sig, SIG_IGN);
8582 # if ENABLE_HUSH_LOOPS
8584 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8590 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8592 # if ENABLE_HUSH_FUNCTIONS
8594 struct function *funcp = new_function(optarg);
8595 /* funcp->name is already set to optarg */
8596 /* funcp->body is set to NULL. It's a special case. */
8597 funcp->body_as_string = argv[optind];
8605 if (set_mode(1, opt, NULL) == 0) /* no error */
8609 fprintf(stderr, "Usage: sh [FILE]...\n"
8610 " or: sh -c command [args]...\n\n");
8616 } /* option parsing loop */
8618 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8619 G.global_argc = argc - (optind - 1);
8620 G.global_argv = argv + (optind - 1);
8621 G.global_argv[0] = argv[0];
8624 G.root_pid = getpid();
8625 G.root_ppid = getppid();
8628 /* If we are login shell... */
8629 if (flags & OPT_login) {
8631 debug_printf("sourcing /etc/profile\n");
8632 input = fopen_for_read("/etc/profile");
8633 if (input != NULL) {
8634 remember_FILE(input);
8635 install_special_sighandlers();
8636 parse_and_run_file(input);
8637 fclose_and_forget(input);
8639 /* bash: after sourcing /etc/profile,
8640 * tries to source (in the given order):
8641 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8642 * stopping on first found. --noprofile turns this off.
8643 * bash also sources ~/.bash_logout on exit.
8644 * If called as sh, skips .bash_XXX files.
8648 if (G.global_argv[1]) {
8651 * "bash <script>" (which is never interactive (unless -i?))
8652 * sources $BASH_ENV here (without scanning $PATH).
8653 * If called as sh, does the same but with $ENV.
8654 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8658 debug_printf("running script '%s'\n", G.global_argv[0]);
8659 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8660 input = xfopen_for_read(G.global_argv[0]);
8661 xfunc_error_retval = 1;
8662 remember_FILE(input);
8663 install_special_sighandlers();
8664 parse_and_run_file(input);
8665 #if ENABLE_FEATURE_CLEAN_UP
8666 fclose_and_forget(input);
8671 /* Up to here, shell was non-interactive. Now it may become one.
8672 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8675 /* A shell is interactive if the '-i' flag was given,
8676 * or if all of the following conditions are met:
8678 * no arguments remaining or the -s flag given
8679 * standard input is a terminal
8680 * standard output is a terminal
8681 * Refer to Posix.2, the description of the 'sh' utility.
8684 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8685 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8686 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8687 if (G_saved_tty_pgrp < 0)
8688 G_saved_tty_pgrp = 0;
8690 /* try to dup stdin to high fd#, >= 255 */
8691 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8692 if (G_interactive_fd < 0) {
8693 /* try to dup to any fd */
8694 G_interactive_fd = dup(STDIN_FILENO);
8695 if (G_interactive_fd < 0) {
8697 G_interactive_fd = 0;
8698 G_saved_tty_pgrp = 0;
8701 // TODO: track & disallow any attempts of user
8702 // to (inadvertently) close/redirect G_interactive_fd
8704 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8705 if (G_interactive_fd) {
8706 close_on_exec_on(G_interactive_fd);
8708 if (G_saved_tty_pgrp) {
8709 /* If we were run as 'hush &', sleep until we are
8710 * in the foreground (tty pgrp == our pgrp).
8711 * If we get started under a job aware app (like bash),
8712 * make sure we are now in charge so we don't fight over
8713 * who gets the foreground */
8715 pid_t shell_pgrp = getpgrp();
8716 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8717 if (G_saved_tty_pgrp == shell_pgrp)
8719 /* send TTIN to ourself (should stop us) */
8720 kill(- shell_pgrp, SIGTTIN);
8724 /* Install more signal handlers */
8725 install_special_sighandlers();
8727 if (G_saved_tty_pgrp) {
8728 /* Set other signals to restore saved_tty_pgrp */
8729 install_fatal_sighandlers();
8730 /* Put ourselves in our own process group
8731 * (bash, too, does this only if ctty is available) */
8732 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8733 /* Grab control of the terminal */
8734 tcsetpgrp(G_interactive_fd, getpid());
8736 enable_restore_tty_pgrp_on_exit();
8738 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8740 const char *hp = get_local_var_value("HISTFILE");
8742 hp = get_local_var_value("HOME");
8744 hp = concat_path_file(hp, ".hush_history");
8749 G.line_input_state->hist_file = hp;
8750 //set_local_var(xasprintf("HISTFILE=%s", ...));
8752 # if ENABLE_FEATURE_SH_HISTFILESIZE
8753 hp = get_local_var_value("HISTFILESIZE");
8754 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8759 install_special_sighandlers();
8761 #elif ENABLE_HUSH_INTERACTIVE
8762 /* No job control compiled in, only prompt/line editing */
8763 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8764 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8765 if (G_interactive_fd < 0) {
8766 /* try to dup to any fd */
8767 G_interactive_fd = dup(STDIN_FILENO);
8768 if (G_interactive_fd < 0)
8770 G_interactive_fd = 0;
8773 if (G_interactive_fd) {
8774 close_on_exec_on(G_interactive_fd);
8776 install_special_sighandlers();
8778 /* We have interactiveness code disabled */
8779 install_special_sighandlers();
8782 * if interactive but not a login shell, sources ~/.bashrc
8783 * (--norc turns this off, --rcfile <file> overrides)
8786 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8787 /* note: ash and hush share this string */
8788 printf("\n\n%s %s\n"
8789 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8792 "hush - the humble shell"
8796 parse_and_run_file(stdin);
8799 hush_exit(G.last_exitcode);
8806 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8811 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8812 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8819 return applet_main_func(argc, argv - argc);
8822 #if ENABLE_HUSH_TEST || BASH_TEST2
8823 static int FAST_FUNC builtin_test(char **argv)
8825 return run_applet_main(argv, test_main);
8828 #if ENABLE_HUSH_ECHO
8829 static int FAST_FUNC builtin_echo(char **argv)
8831 return run_applet_main(argv, echo_main);
8834 #if ENABLE_HUSH_PRINTF
8835 static int FAST_FUNC builtin_printf(char **argv)
8837 return run_applet_main(argv, printf_main);
8841 #if ENABLE_HUSH_HELP
8842 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8844 const struct built_in_command *x;
8847 "Built-in commands:\n"
8848 "------------------\n");
8849 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8851 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8853 return EXIT_SUCCESS;
8857 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8858 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8860 show_history(G.line_input_state);
8861 return EXIT_SUCCESS;
8865 static char **skip_dash_dash(char **argv)
8868 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8873 static int FAST_FUNC builtin_cd(char **argv)
8877 argv = skip_dash_dash(argv);
8879 if (newdir == NULL) {
8880 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8881 * bash says "bash: cd: HOME not set" and does nothing
8884 const char *home = get_local_var_value("HOME");
8885 newdir = home ? home : "/";
8887 if (chdir(newdir)) {
8888 /* Mimic bash message exactly */
8889 bb_perror_msg("cd: %s", newdir);
8890 return EXIT_FAILURE;
8892 /* Read current dir (get_cwd(1) is inside) and set PWD.
8893 * Note: do not enforce exporting. If PWD was unset or unexported,
8894 * set it again, but do not export. bash does the same.
8896 set_pwd_var(/*exp:*/ 0);
8897 return EXIT_SUCCESS;
8900 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8903 return EXIT_SUCCESS;
8906 static int FAST_FUNC builtin_eval(char **argv)
8908 int rcode = EXIT_SUCCESS;
8910 argv = skip_dash_dash(argv);
8912 char *str = expand_strvec_to_string(argv);
8914 * eval "echo Hi; done" ("done" is syntax error):
8915 * "echo Hi" will not execute too.
8917 parse_and_run_string(str);
8919 rcode = G.last_exitcode;
8924 static int FAST_FUNC builtin_exec(char **argv)
8926 argv = skip_dash_dash(argv);
8927 if (argv[0] == NULL)
8928 return EXIT_SUCCESS; /* bash does this */
8930 /* Careful: we can end up here after [v]fork. Do not restore
8931 * tty pgrp then, only top-level shell process does that */
8932 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8933 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8935 /* TODO: if exec fails, bash does NOT exit! We do.
8936 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8937 * and tcsetpgrp, and this is inherently racy.
8939 execvp_or_die(argv);
8942 static int FAST_FUNC builtin_exit(char **argv)
8944 debug_printf_exec("%s()\n", __func__);
8946 /* interactive bash:
8947 * # trap "echo EEE" EXIT
8950 * There are stopped jobs.
8951 * (if there are _stopped_ jobs, running ones don't count)
8954 * EEE (then bash exits)
8956 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8959 /* note: EXIT trap is run by hush_exit */
8960 argv = skip_dash_dash(argv);
8961 if (argv[0] == NULL)
8962 hush_exit(G.last_exitcode);
8963 /* mimic bash: exit 123abc == exit 255 + error msg */
8964 xfunc_error_retval = 255;
8965 /* bash: exit -2 == exit 254, no error msg */
8966 hush_exit(xatoi(argv[0]) & 0xff);
8969 #if ENABLE_HUSH_TYPE
8970 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8971 static int FAST_FUNC builtin_type(char **argv)
8973 int ret = EXIT_SUCCESS;
8979 if (0) {} /* make conditional compile easier below */
8980 /*else if (find_alias(*argv))
8981 type = "an alias";*/
8982 #if ENABLE_HUSH_FUNCTIONS
8983 else if (find_function(*argv))
8984 type = "a function";
8986 else if (find_builtin(*argv))
8987 type = "a shell builtin";
8988 else if ((path = find_in_path(*argv)) != NULL)
8991 bb_error_msg("type: %s: not found", *argv);
8996 printf("%s is %s\n", *argv, type);
9004 #if ENABLE_HUSH_READ
9005 /* Interruptibility of read builtin in bash
9006 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9008 * Empty trap makes read ignore corresponding signal, for any signal.
9011 * - terminates non-interactive shell;
9012 * - interrupts read in interactive shell;
9013 * if it has non-empty trap:
9014 * - executes trap and returns to command prompt in interactive shell;
9015 * - executes trap and returns to read in non-interactive shell;
9017 * - is ignored (does not interrupt) read in interactive shell;
9018 * - terminates non-interactive shell;
9019 * if it has non-empty trap:
9020 * - executes trap and returns to read;
9022 * - terminates shell (regardless of interactivity);
9023 * if it has non-empty trap:
9024 * - executes trap and returns to read;
9025 * SIGCHLD from children:
9026 * - does not interrupt read regardless of interactivity:
9027 * try: sleep 1 & read x; echo $x
9029 static int FAST_FUNC builtin_read(char **argv)
9039 /* "!": do not abort on errors.
9040 * Option string must start with "sr" to match BUILTIN_READ_xxx
9042 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9043 if (read_flags == (uint32_t)-1)
9044 return EXIT_FAILURE;
9046 ifs = get_local_var_value("IFS"); /* can be NULL */
9049 r = shell_builtin_read(set_local_var_from_halves,
9059 if ((uintptr_t)r == 1 && errno == EINTR) {
9060 unsigned sig = check_and_run_traps();
9065 if ((uintptr_t)r > 1) {
9066 bb_error_msg("%s", r);
9067 r = (char*)(uintptr_t)1;
9070 return (uintptr_t)r;
9074 #if ENABLE_HUSH_UMASK
9075 static int FAST_FUNC builtin_umask(char **argv)
9082 argv = skip_dash_dash(argv);
9084 mode_t old_mask = mask;
9086 /* numeric umasks are taken as-is */
9087 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9088 if (!isdigit(argv[0][0]))
9090 mask = bb_parse_mode(argv[0], mask);
9091 if (!isdigit(argv[0][0]))
9093 if ((unsigned)mask > 0777) {
9096 * bash: umask: 'q': invalid symbolic mode operator
9097 * bash: umask: 999: octal number out of range
9099 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9104 printf("%04o\n", (unsigned) mask);
9105 /* fall through and restore mask which we set to 0 */
9109 return !rc; /* rc != 0 - success */
9113 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9114 static void print_escaped(const char *s)
9119 const char *p = strchrnul(s, '\'');
9120 /* print 'xxxx', possibly just '' */
9121 printf("'%.*s'", (int)(p - s), s);
9126 /* s points to '; print "'''...'''" */
9128 do putchar('\''); while (*++s == '\'');
9134 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9135 # if !ENABLE_HUSH_LOCAL
9136 #define helper_export_local(argv, exp, lvl) \
9137 helper_export_local(argv, exp)
9139 static void helper_export_local(char **argv, int exp, int lvl)
9143 char *name_end = strchrnul(name, '=');
9145 /* So far we do not check that name is valid (TODO?) */
9147 if (*name_end == '\0') {
9148 struct variable *var, **vpp;
9150 vpp = get_ptr_to_local_var(name, name_end - name);
9151 var = vpp ? *vpp : NULL;
9153 if (exp == -1) { /* unexporting? */
9154 /* export -n NAME (without =VALUE) */
9156 var->flg_export = 0;
9157 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9159 } /* else: export -n NOT_EXISTING_VAR: no-op */
9162 if (exp == 1) { /* exporting? */
9163 /* export NAME (without =VALUE) */
9165 var->flg_export = 1;
9166 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9167 putenv(var->varstr);
9171 # if ENABLE_HUSH_LOCAL
9172 if (exp == 0 /* local? */
9173 && var && var->func_nest_level == lvl
9175 /* "local x=abc; ...; local x" - ignore second local decl */
9179 /* Exporting non-existing variable.
9180 * bash does not put it in environment,
9181 * but remembers that it is exported,
9182 * and does put it in env when it is set later.
9183 * We just set it to "" and export. */
9184 /* Or, it's "local NAME" (without =VALUE).
9185 * bash sets the value to "". */
9186 name = xasprintf("%s=", name);
9188 /* (Un)exporting/making local NAME=VALUE */
9189 name = xstrdup(name);
9191 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9196 #if ENABLE_HUSH_EXPORT
9197 static int FAST_FUNC builtin_export(char **argv)
9199 unsigned opt_unexport;
9201 #if ENABLE_HUSH_EXPORT_N
9202 /* "!": do not abort on errors */
9203 opt_unexport = getopt32(argv, "!n");
9204 if (opt_unexport == (uint32_t)-1)
9205 return EXIT_FAILURE;
9212 if (argv[0] == NULL) {
9219 /* ash emits: export VAR='VAL'
9220 * bash: declare -x VAR="VAL"
9221 * we follow ash example */
9222 const char *s = *e++;
9223 const char *p = strchr(s, '=');
9225 if (!p) /* wtf? take next variable */
9228 printf("export %.*s", (int)(p - s) + 1, s);
9229 print_escaped(p + 1);
9233 /*fflush_all(); - done after each builtin anyway */
9235 return EXIT_SUCCESS;
9238 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9240 return EXIT_SUCCESS;
9244 #if ENABLE_HUSH_LOCAL
9245 static int FAST_FUNC builtin_local(char **argv)
9247 if (G.func_nest_level == 0) {
9248 bb_error_msg("%s: not in a function", argv[0]);
9249 return EXIT_FAILURE; /* bash compat */
9251 helper_export_local(argv, 0, G.func_nest_level);
9252 return EXIT_SUCCESS;
9256 #if ENABLE_HUSH_UNSET
9257 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9258 static int FAST_FUNC builtin_unset(char **argv)
9263 /* "!": do not abort on errors */
9264 /* "+": stop at 1st non-option */
9265 opts = getopt32(argv, "!+vf");
9266 if (opts == (unsigned)-1)
9267 return EXIT_FAILURE;
9269 bb_error_msg("unset: -v and -f are exclusive");
9270 return EXIT_FAILURE;
9276 if (!(opts & 2)) { /* not -f */
9277 if (unset_local_var(*argv)) {
9278 /* unset <nonexistent_var> doesn't fail.
9279 * Error is when one tries to unset RO var.
9280 * Message was printed by unset_local_var. */
9284 # if ENABLE_HUSH_FUNCTIONS
9296 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9297 * built-in 'set' handler
9299 * set [-abCefhmnuvx] [-o option] [argument...]
9300 * set [+abCefhmnuvx] [+o option] [argument...]
9301 * set -- [argument...]
9304 * Implementations shall support the options in both their hyphen and
9305 * plus-sign forms. These options can also be specified as options to sh.
9307 * Write out all variables and their values: set
9308 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9309 * Turn on the -x and -v options: set -xv
9310 * Unset all positional parameters: set --
9311 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9312 * Set the positional parameters to the expansion of x, even if x expands
9313 * with a leading '-' or '+': set -- $x
9315 * So far, we only support "set -- [argument...]" and some of the short names.
9317 static int FAST_FUNC builtin_set(char **argv)
9320 char **pp, **g_argv;
9321 char *arg = *++argv;
9325 for (e = G.top_var; e; e = e->next)
9327 return EXIT_SUCCESS;
9331 if (strcmp(arg, "--") == 0) {
9335 if (arg[0] != '+' && arg[0] != '-')
9337 for (n = 1; arg[n]; ++n) {
9338 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9340 if (arg[n] == 'o' && argv[1])
9343 } while ((arg = *++argv) != NULL);
9344 /* Now argv[0] is 1st argument */
9347 return EXIT_SUCCESS;
9350 /* NB: G.global_argv[0] ($0) is never freed/changed */
9351 g_argv = G.global_argv;
9352 if (G.global_args_malloced) {
9358 G.global_args_malloced = 1;
9359 pp = xzalloc(sizeof(pp[0]) * 2);
9360 pp[0] = g_argv[0]; /* retain $0 */
9363 /* This realloc's G.global_argv */
9364 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9371 return EXIT_SUCCESS;
9373 /* Nothing known, so abort */
9375 bb_error_msg("set: %s: invalid option", arg);
9376 return EXIT_FAILURE;
9380 static int FAST_FUNC builtin_shift(char **argv)
9383 argv = skip_dash_dash(argv);
9387 if (n >= 0 && n < G.global_argc) {
9388 if (G_global_args_malloced) {
9391 free(G.global_argv[m++]);
9394 memmove(&G.global_argv[1], &G.global_argv[n+1],
9395 G.global_argc * sizeof(G.global_argv[0]));
9396 return EXIT_SUCCESS;
9398 return EXIT_FAILURE;
9401 static int FAST_FUNC builtin_source(char **argv)
9403 char *arg_path, *filename;
9406 char *args_need_save;
9407 #if ENABLE_HUSH_FUNCTIONS
9411 argv = skip_dash_dash(argv);
9414 /* bash says: "bash: .: filename argument required" */
9415 return 2; /* bash compat */
9418 if (!strchr(filename, '/')) {
9419 arg_path = find_in_path(filename);
9421 filename = arg_path;
9423 input = remember_FILE(fopen_or_warn(filename, "r"));
9426 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9427 /* POSIX: non-interactive shell should abort here,
9428 * not merely fail. So far no one complained :)
9430 return EXIT_FAILURE;
9433 #if ENABLE_HUSH_FUNCTIONS
9434 sv_flg = G_flag_return_in_progress;
9435 /* "we are inside sourced file, ok to use return" */
9436 G_flag_return_in_progress = -1;
9438 args_need_save = argv[1]; /* used as a boolean variable */
9440 save_and_replace_G_args(&sv, argv);
9442 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9443 G.last_exitcode = 0;
9444 parse_and_run_file(input);
9445 fclose_and_forget(input);
9447 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9448 restore_G_args(&sv, argv);
9449 #if ENABLE_HUSH_FUNCTIONS
9450 G_flag_return_in_progress = sv_flg;
9453 return G.last_exitcode;
9456 #if ENABLE_HUSH_TRAP
9457 static int FAST_FUNC builtin_trap(char **argv)
9463 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9468 /* No args: print all trapped */
9469 for (i = 0; i < NSIG; ++i) {
9472 print_escaped(G_traps[i]);
9473 /* note: bash adds "SIG", but only if invoked
9474 * as "bash". If called as "sh", or if set -o posix,
9475 * then it prints short signal names.
9476 * We are printing short names: */
9477 printf(" %s\n", get_signame(i));
9480 /*fflush_all(); - done after each builtin anyway */
9481 return EXIT_SUCCESS;
9485 /* If first arg is a number: reset all specified signals */
9486 sig = bb_strtou(*argv, NULL, 10);
9492 sighandler_t handler;
9494 sig = get_signum(*argv++);
9495 if (sig < 0 || sig >= NSIG) {
9497 /* Mimic bash message exactly */
9498 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9503 G_traps[sig] = xstrdup(new_cmd);
9505 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9506 get_signame(sig), sig, G_traps[sig]);
9508 /* There is no signal for 0 (EXIT) */
9513 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9515 /* We are removing trap handler */
9516 handler = pick_sighandler(sig);
9517 install_sighandler(sig, handler);
9522 if (!argv[1]) { /* no second arg */
9523 bb_error_msg("trap: invalid arguments");
9524 return EXIT_FAILURE;
9527 /* First arg is "-": reset all specified to default */
9528 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9529 /* Everything else: set arg as signal handler
9530 * (includes "" case, which ignores signal) */
9531 if (argv[0][0] == '-') {
9532 if (argv[0][1] == '\0') { /* "-" */
9533 /* new_cmd remains NULL: "reset these sigs" */
9536 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9539 /* else: "-something", no special meaning */
9544 goto process_sig_list;
9549 static struct pipe *parse_jobspec(const char *str)
9554 if (sscanf(str, "%%%u", &jobnum) != 1) {
9556 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9558 bb_error_msg("bad argument '%s'", str);
9561 /* It is "%%", "%+" or "%" - current job */
9562 jobnum = G.last_jobid;
9564 bb_error_msg("no current job");
9568 for (pi = G.job_list; pi; pi = pi->next) {
9569 if (pi->jobid == jobnum) {
9573 bb_error_msg("%u: no such job", jobnum);
9577 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9580 const char *status_string;
9582 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9583 for (job = G.job_list; job; job = job->next) {
9584 if (job->alive_cmds == job->stopped_cmds)
9585 status_string = "Stopped";
9587 status_string = "Running";
9589 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9591 return EXIT_SUCCESS;
9594 /* built-in 'fg' and 'bg' handler */
9595 static int FAST_FUNC builtin_fg_bg(char **argv)
9600 if (!G_interactive_fd)
9601 return EXIT_FAILURE;
9603 /* If they gave us no args, assume they want the last backgrounded task */
9605 for (pi = G.job_list; pi; pi = pi->next) {
9606 if (pi->jobid == G.last_jobid) {
9610 bb_error_msg("%s: no current job", argv[0]);
9611 return EXIT_FAILURE;
9614 pi = parse_jobspec(argv[1]);
9616 return EXIT_FAILURE;
9618 /* TODO: bash prints a string representation
9619 * of job being foregrounded (like "sleep 1 | cat") */
9620 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9621 /* Put the job into the foreground. */
9622 tcsetpgrp(G_interactive_fd, pi->pgrp);
9625 /* Restart the processes in the job */
9626 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9627 for (i = 0; i < pi->num_cmds; i++) {
9628 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9630 pi->stopped_cmds = 0;
9632 i = kill(- pi->pgrp, SIGCONT);
9634 if (errno == ESRCH) {
9635 delete_finished_bg_job(pi);
9636 return EXIT_SUCCESS;
9638 bb_perror_msg("kill (SIGCONT)");
9641 if (argv[0][0] == 'f') {
9643 return checkjobs_and_fg_shell(pi);
9645 return EXIT_SUCCESS;
9649 #if ENABLE_HUSH_KILL
9650 static int FAST_FUNC builtin_kill(char **argv)
9654 # if ENABLE_HUSH_JOB
9655 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9663 if (argv[i][0] != '%')
9666 * "kill %N" - job kill
9667 * Converting to pgrp / pid kill
9669 pi = parse_jobspec(argv[i]);
9671 /* Eat bad jobspec */
9675 argv[j - 1] = argv[j];
9682 * In jobs started under job control, we signal
9683 * entire process group by kill -PGRP_ID.
9684 * This happens, f.e., in interactive shell.
9686 * Otherwise, we signal each child via
9687 * kill PID1 PID2 PID3.
9689 * sh -c 'sleep 1|sleep 1 & kill %1'
9690 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9691 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9693 n = G_interactive_fd ? 1 : pi->num_cmds;
9694 dst = alloca(n * sizeof(int)*4);
9696 if (G_interactive_fd)
9697 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9698 else for (j = 0; j < n; j++) {
9699 struct command *cmd = &pi->cmds[j];
9700 /* Skip exited members of the job */
9704 * kill_main has matching code to expect
9705 * leading space. Needed to not confuse
9706 * negative pids with "kill -SIGNAL_NO" syntax
9708 dst += sprintf(dst, " %u", (int)cmd->pid);
9711 } while (argv[++i]);
9715 if (argv[1] || ret == 0) {
9716 ret = run_applet_main(argv, kill_main);
9718 /* else: ret = 1, "kill %bad_jobspec" case */
9723 #if ENABLE_HUSH_WAIT
9724 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9725 #if !ENABLE_HUSH_JOB
9726 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9728 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9735 if (!sigisemptyset(&G.pending_set))
9738 /* waitpid is not interruptible by SA_RESTARTed
9739 * signals which we use. Thus, this ugly dance:
9742 /* Make sure possible SIGCHLD is stored in kernel's
9743 * pending signal mask before we call waitpid.
9744 * Or else we may race with SIGCHLD, lose it,
9745 * and get stuck in sigsuspend...
9747 sigfillset(&oldset); /* block all signals, remember old set */
9748 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9750 if (!sigisemptyset(&G.pending_set)) {
9751 /* Crap! we raced with some signal! */
9755 /*errno = 0; - checkjobs does this */
9756 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9757 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9758 debug_printf_exec("checkjobs:%d\n", ret);
9761 int rcode = job_exited_or_stopped(waitfor_pipe);
9762 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9765 sigprocmask(SIG_SETMASK, &oldset, NULL);
9770 /* if ECHILD, there are no children (ret is -1 or 0) */
9771 /* if ret == 0, no children changed state */
9772 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9773 if (errno == ECHILD || ret) {
9775 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9777 sigprocmask(SIG_SETMASK, &oldset, NULL);
9780 /* Wait for SIGCHLD or any other signal */
9781 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9782 /* Note: sigsuspend invokes signal handler */
9783 sigsuspend(&oldset);
9785 sigprocmask(SIG_SETMASK, &oldset, NULL);
9787 /* So, did we get a signal? */
9788 sig = check_and_run_traps();
9789 if (sig /*&& sig != SIGCHLD - always true */) {
9793 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9798 static int FAST_FUNC builtin_wait(char **argv)
9803 argv = skip_dash_dash(argv);
9804 if (argv[0] == NULL) {
9805 /* Don't care about wait results */
9806 /* Note 1: must wait until there are no more children */
9807 /* Note 2: must be interruptible */
9809 * $ sleep 3 & sleep 6 & wait
9814 * $ sleep 3 & sleep 6 & wait
9818 * ^C <-- after ~4 sec from keyboard
9821 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9825 pid_t pid = bb_strtou(*argv, NULL, 10);
9826 if (errno || pid <= 0) {
9828 if (argv[0][0] == '%') {
9829 struct pipe *wait_pipe;
9830 ret = 127; /* bash compat for bad jobspecs */
9831 wait_pipe = parse_jobspec(*argv);
9833 ret = job_exited_or_stopped(wait_pipe);
9835 ret = wait_for_child_or_signal(wait_pipe, 0);
9837 /* else: parse_jobspec() already emitted error msg */
9841 /* mimic bash message */
9842 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9844 continue; /* bash checks all argv[] */
9847 /* Do we have such child? */
9848 ret = waitpid(pid, &status, WNOHANG);
9851 if (errno == ECHILD) {
9852 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9853 /* "wait $!" but last bg task has already exited. Try:
9854 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9855 * In bash it prints exitcode 0, then 3.
9856 * In dash, it is 127.
9858 /* ret = G.last_bg_pid_exitstatus - FIXME */
9860 /* Example: "wait 1". mimic bash message */
9861 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9865 bb_perror_msg("wait %s", *argv);
9868 continue; /* bash checks all argv[] */
9871 /* Yes, and it still runs */
9872 ret = wait_for_child_or_signal(NULL, pid);
9874 /* Yes, and it just exited */
9875 process_wait_result(NULL, pid, status);
9876 ret = WEXITSTATUS(status);
9877 if (WIFSIGNALED(status))
9878 ret = 128 + WTERMSIG(status);
9886 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9887 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9890 def = bb_strtou(argv[1], NULL, 10);
9891 if (errno || def < def_min || argv[2]) {
9892 bb_error_msg("%s: bad arguments", argv[0]);
9900 #if ENABLE_HUSH_LOOPS
9901 static int FAST_FUNC builtin_break(char **argv)
9904 if (G.depth_of_loop == 0) {
9905 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9906 /* if we came from builtin_continue(), need to undo "= 1" */
9907 G.flag_break_continue = 0;
9908 return EXIT_SUCCESS; /* bash compat */
9910 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9912 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9913 if (depth == UINT_MAX)
9914 G.flag_break_continue = BC_BREAK;
9915 if (G.depth_of_loop < depth)
9916 G.depth_break_continue = G.depth_of_loop;
9918 return EXIT_SUCCESS;
9921 static int FAST_FUNC builtin_continue(char **argv)
9923 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9924 return builtin_break(argv);
9928 #if ENABLE_HUSH_FUNCTIONS
9929 static int FAST_FUNC builtin_return(char **argv)
9933 if (G_flag_return_in_progress != -1) {
9934 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9935 return EXIT_FAILURE; /* bash compat */
9938 G_flag_return_in_progress = 1;
9941 * out of range: wraps around at 256, does not error out
9942 * non-numeric param:
9943 * f() { false; return qwe; }; f; echo $?
9944 * bash: return: qwe: numeric argument required <== we do this
9945 * 255 <== we also do this
9947 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
9952 #if ENABLE_HUSH_MEMLEAK
9953 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9958 # ifdef M_TRIM_THRESHOLD
9959 /* Optional. Reduces probability of false positives */
9962 /* Crude attempt to find where "free memory" starts,
9963 * sans fragmentation. */
9965 l = (unsigned long)p;
9968 if (l < (unsigned long)p) l = (unsigned long)p;
9974 struct mallinfo mi = mallinfo();
9975 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9976 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9980 if (!G.memleak_value)
9981 G.memleak_value = l;
9983 l -= G.memleak_value;
9990 /* Exitcode is "how many kilobytes we leaked since 1st call" */