1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * fc -l[nr] [BEG] [END]: list range of commands in history
62 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
63 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
66 * redirection of stdout+stderr: &> and >&
67 * reserved words: function select
68 * advanced test: [[ ]]
69 * process substitution: <(list) and >(list)
72 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
73 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
74 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
76 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
77 * This is exactly equivalent to let "EXPR".
78 * $[EXPR]: synonym for $((EXPR))
79 * indirect expansion: ${!VAR}
80 * substring op on @: ${@:n:m}
83 * Some builtins mandated by standards:
84 * newgrp [GRP]: not a builtin in bash but a suid binary
85 * which spawns a new shell with new group ID
86 * In bash, export builtin is special, its arguments are assignments
87 * and therefore expansion of them should be "one-word" expansion:
88 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
90 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
91 * ls: cannot access i=a: No such file or directory
92 * ls: cannot access b: No such file or directory
93 * Note1: same applies to local builtin.
94 * Note2: bash 3.2.33(1) does this only if export word itself
96 * $ export i=`echo 'aaa bbb'`; echo "$i"
98 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
102 //config: bool "hush (64 kb)"
105 //config: hush is a small shell. It handles the normal flow control
106 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
107 //config: case/esac. Redirections, here documents, $((arithmetic))
108 //config: and functions are supported.
110 //config: It will compile and work on no-mmu systems.
112 //config: It does not handle select, aliases, tilde expansion,
113 //config: &>file and >&file redirection of stdout+stderr.
115 //config:config HUSH_BASH_COMPAT
116 //config: bool "bash-compatible extensions"
118 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
120 //config:config HUSH_BRACE_EXPANSION
121 //config: bool "Brace expansion"
123 //config: depends on HUSH_BASH_COMPAT
125 //config: Enable {abc,def} extension.
127 //config:config HUSH_INTERACTIVE
128 //config: bool "Interactive mode"
130 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
132 //config: Enable interactive mode (prompt and command editing).
133 //config: Without this, hush simply reads and executes commands
134 //config: from stdin just like a shell script from a file.
135 //config: No prompt, no PS1/PS2 magic shell variables.
137 //config:config HUSH_SAVEHISTORY
138 //config: bool "Save command history to .hush_history"
140 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
142 //config:config HUSH_JOB
143 //config: bool "Job control"
145 //config: depends on HUSH_INTERACTIVE
147 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
148 //config: command (not entire shell), fg/bg builtins work. Without this option,
149 //config: "cmd &" still works by simply spawning a process and immediately
150 //config: prompting for next command (or executing next command in a script),
151 //config: but no separate process group is formed.
153 //config:config HUSH_TICK
154 //config: bool "Support process substitution"
156 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
158 //config: Enable `command` and $(command).
160 //config:config HUSH_IF
161 //config: bool "Support if/then/elif/else/fi"
163 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
165 //config:config HUSH_LOOPS
166 //config: bool "Support for, while and until loops"
168 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
170 //config:config HUSH_CASE
171 //config: bool "Support case ... esac statement"
173 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
175 //config: Enable case ... esac statement. +400 bytes.
177 //config:config HUSH_FUNCTIONS
178 //config: bool "Support funcname() { commands; } syntax"
180 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
182 //config: Enable support for shell functions. +800 bytes.
184 //config:config HUSH_LOCAL
185 //config: bool "local builtin"
187 //config: depends on HUSH_FUNCTIONS
189 //config: Enable support for local variables in functions.
191 //config:config HUSH_RANDOM_SUPPORT
192 //config: bool "Pseudorandom generator and $RANDOM variable"
194 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
196 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
197 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
199 //config:config HUSH_MODE_X
200 //config: bool "Support 'hush -x' option and 'set -x' command"
202 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
204 //config: This instructs hush to print commands before execution.
205 //config: Adds ~300 bytes.
207 //config:config HUSH_ECHO
208 //config: bool "echo builtin"
210 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
212 //config:config HUSH_PRINTF
213 //config: bool "printf builtin"
215 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
217 //config:config HUSH_TEST
218 //config: bool "test builtin"
220 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
222 //config:config HUSH_HELP
223 //config: bool "help builtin"
225 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
227 //config:config HUSH_EXPORT
228 //config: bool "export builtin"
230 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
232 //config:config HUSH_EXPORT_N
233 //config: bool "Support 'export -n' option"
235 //config: depends on HUSH_EXPORT
237 //config: export -n unexports variables. It is a bash extension.
239 //config:config HUSH_READONLY
240 //config: bool "readonly builtin"
242 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
244 //config: Enable support for read-only variables.
246 //config:config HUSH_KILL
247 //config: bool "kill builtin (supports kill %jobspec)"
249 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
251 //config:config HUSH_WAIT
252 //config: bool "wait builtin"
254 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
256 //config:config HUSH_TRAP
257 //config: bool "trap builtin"
259 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
261 //config:config HUSH_TYPE
262 //config: bool "type builtin"
264 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
266 //config:config HUSH_TIMES
267 //config: bool "times builtin"
269 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
271 //config:config HUSH_READ
272 //config: bool "read builtin"
274 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
276 //config:config HUSH_SET
277 //config: bool "set builtin"
279 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
281 //config:config HUSH_UNSET
282 //config: bool "unset builtin"
284 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
286 //config:config HUSH_ULIMIT
287 //config: bool "ulimit builtin"
289 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
291 //config:config HUSH_UMASK
292 //config: bool "umask builtin"
294 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
296 //config:config HUSH_GETOPTS
297 //config: bool "getopts builtin"
299 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
301 //config:config HUSH_MEMLEAK
302 //config: bool "memleak builtin (debugging)"
304 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
306 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
307 // APPLET_ODDNAME:name main location suid_type help
308 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
309 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
311 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
312 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
313 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
314 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
316 /* -i (interactive) and -s (read stdin) are also accepted,
317 * but currently do nothing, therefore aren't shown in help.
318 * NOMMU-specific options are not meant to be used by users,
319 * therefore we don't show them either.
321 //usage:#define hush_trivial_usage
322 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
323 //usage:#define hush_full_usage "\n\n"
324 //usage: "Unix shell interpreter"
326 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
327 || defined(__APPLE__) \
329 # include <malloc.h> /* for malloc_trim */
332 /* #include <dmalloc.h> */
334 # include <fnmatch.h>
336 #include <sys/times.h>
337 #include <sys/utsname.h> /* for setting $HOSTNAME */
339 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
341 #include "shell_common.h"
344 #if ENABLE_HUSH_RANDOM_SUPPORT
347 # define CLEAR_RANDOM_T(rnd) ((void)0)
349 #ifndef F_DUPFD_CLOEXEC
350 # define F_DUPFD_CLOEXEC F_DUPFD
353 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
357 /* So far, all bash compat is controlled by one config option */
358 /* Separate defines document which part of code implements what */
359 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
360 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
361 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
362 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
363 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
364 #define BASH_READ_D ENABLE_HUSH_BASH_COMPAT
368 #define LEAK_HUNTING 0
369 #define BUILD_AS_NOMMU 0
370 /* Enable/disable sanity checks. Ok to enable in production,
371 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
372 * Keeping 1 for now even in released versions.
375 /* Slightly bigger (+200 bytes), but faster hush.
376 * So far it only enables a trick with counting SIGCHLDs and forks,
377 * which allows us to do fewer waitpid's.
378 * (we can detect a case where neither forks were done nor SIGCHLDs happened
379 * and therefore waitpid will return the same result as last time)
381 #define ENABLE_HUSH_FAST 0
382 /* TODO: implement simplified code for users which do not need ${var%...} ops
383 * So far ${var%...} ops are always enabled:
385 #define ENABLE_HUSH_DOLLAR_OPS 1
390 # undef USE_FOR_NOMMU
393 # define USE_FOR_NOMMU(...) __VA_ARGS__
394 # define USE_FOR_MMU(...)
397 #include "NUM_APPLETS.h"
399 /* STANDALONE does not make sense, and won't compile */
400 # undef CONFIG_FEATURE_SH_STANDALONE
401 # undef ENABLE_FEATURE_SH_STANDALONE
402 # undef IF_FEATURE_SH_STANDALONE
403 # undef IF_NOT_FEATURE_SH_STANDALONE
404 # define ENABLE_FEATURE_SH_STANDALONE 0
405 # define IF_FEATURE_SH_STANDALONE(...)
406 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
409 #if !ENABLE_HUSH_INTERACTIVE
410 # undef ENABLE_FEATURE_EDITING
411 # define ENABLE_FEATURE_EDITING 0
412 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
413 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
414 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
415 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
418 /* Do we support ANY keywords? */
419 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
420 # define HAS_KEYWORDS 1
421 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
422 # define IF_HAS_NO_KEYWORDS(...)
424 # define HAS_KEYWORDS 0
425 # define IF_HAS_KEYWORDS(...)
426 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
429 /* If you comment out one of these below, it will be #defined later
430 * to perform debug printfs to stderr: */
431 #define debug_printf(...) do {} while (0)
432 /* Finer-grained debug switches */
433 #define debug_printf_parse(...) do {} while (0)
434 #define debug_print_tree(a, b) do {} while (0)
435 #define debug_printf_exec(...) do {} while (0)
436 #define debug_printf_env(...) do {} while (0)
437 #define debug_printf_jobs(...) do {} while (0)
438 #define debug_printf_expand(...) do {} while (0)
439 #define debug_printf_varexp(...) do {} while (0)
440 #define debug_printf_glob(...) do {} while (0)
441 #define debug_printf_redir(...) do {} while (0)
442 #define debug_printf_list(...) do {} while (0)
443 #define debug_printf_subst(...) do {} while (0)
444 #define debug_printf_clean(...) do {} while (0)
446 #define ERR_PTR ((void*)(long)1)
448 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
450 #define _SPECIAL_VARS_STR "_*@$!?#"
451 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
452 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
453 #if BASH_PATTERN_SUBST
454 /* Support / and // replace ops */
455 /* Note that // is stored as \ in "encoded" string representation */
456 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
457 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
458 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
460 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
461 # define VAR_SUBST_OPS "%#:-=+?"
462 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
465 #define SPECIAL_VAR_SYMBOL 3
469 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
471 /* This supports saving pointers malloced in vfork child,
472 * to be freed in the parent.
475 typedef struct nommu_save_t {
477 struct variable *old_vars;
479 char **argv_from_re_execing;
492 #if ENABLE_HUSH_LOOPS
499 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
504 /* three pseudo-keywords support contrived "case" syntax: */
505 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
506 RES_MATCH , /* "word)" */
507 RES_CASE_BODY, /* "this command is inside CASE" */
514 typedef struct o_string {
516 int length; /* position where data is appended */
519 /* At least some part of the string was inside '' or "",
520 * possibly empty one: word"", wo''rd etc. */
521 smallint has_quoted_part;
522 smallint has_empty_slot;
523 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
526 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
528 /* Protect newly added chars against globbing
529 * by prepending \ to *, ?, [, \ */
530 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
533 MAYBE_ASSIGNMENT = 0,
534 DEFINITELY_ASSIGNMENT = 1,
536 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
539 /* Used for initialization: o_string foo = NULL_O_STRING; */
540 #define NULL_O_STRING { NULL }
542 #ifndef debug_printf_parse
543 static const char *const assignment_flag[] = {
545 "DEFINITELY_ASSIGNMENT",
551 typedef struct in_str {
553 #if ENABLE_HUSH_INTERACTIVE
554 smallint promptmode; /* 0: PS1, 1: PS2 */
561 /* The descrip member of this structure is only used to make
562 * debugging output pretty */
563 static const struct {
565 signed char default_fd;
568 { O_RDONLY, 0, "<" },
569 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
570 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
571 { O_CREAT|O_RDWR, 1, "<>" },
572 { O_RDONLY, 0, "<<" },
573 /* Should not be needed. Bogus default_fd helps in debugging */
574 /* { O_RDONLY, 77, "<<" }, */
577 struct redir_struct {
578 struct redir_struct *next;
579 char *rd_filename; /* filename */
580 int rd_fd; /* fd to redirect */
581 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
583 smallint rd_type; /* (enum redir_type) */
584 /* note: for heredocs, rd_filename contains heredoc delimiter,
585 * and subsequently heredoc itself; and rd_dup is a bitmask:
586 * bit 0: do we need to trim leading tabs?
587 * bit 1: is heredoc quoted (<<'delim' syntax) ?
590 typedef enum redir_type {
592 REDIRECT_OVERWRITE = 1,
595 REDIRECT_HEREDOC = 4,
596 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
599 REDIRFD_SYNTAX_ERR = -2,
600 REDIRFD_TO_FILE = -1,
601 /* otherwise, rd_fd is redirected to rd_dup */
603 HEREDOC_SKIPTABS = 1,
609 pid_t pid; /* 0 if exited */
610 int assignment_cnt; /* how many argv[i] are assignments? */
611 smallint cmd_type; /* CMD_xxx */
613 #define CMD_SUBSHELL 1
615 /* used for "[[ EXPR ]]" */
616 # define CMD_SINGLEWORD_NOGLOB 2
618 #if ENABLE_HUSH_FUNCTIONS
619 # define CMD_FUNCDEF 3
622 smalluint cmd_exitcode;
623 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
626 char *group_as_string;
628 #if ENABLE_HUSH_FUNCTIONS
629 struct function *child_func;
630 /* This field is used to prevent a bug here:
631 * while...do f1() {a;}; f1; f1() {b;}; f1; done
632 * When we execute "f1() {a;}" cmd, we create new function and clear
633 * cmd->group, cmd->group_as_string, cmd->argv[0].
634 * When we execute "f1() {b;}", we notice that f1 exists,
635 * and that its "parent cmd" struct is still "alive",
636 * we put those fields back into cmd->xxx
637 * (struct function has ->parent_cmd ptr to facilitate that).
638 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
639 * Without this trick, loop would execute a;b;b;b;...
640 * instead of correct sequence a;b;a;b;...
641 * When command is freed, it severs the link
642 * (sets ->child_func->parent_cmd to NULL).
645 char **argv; /* command name and arguments */
646 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
647 * and on execution these are substituted with their values.
648 * Substitution can make _several_ words out of one argv[n]!
649 * Example: argv[0]=='.^C*^C.' here: echo .$*.
650 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
652 struct redir_struct *redirects; /* I/O redirections */
654 /* Is there anything in this command at all? */
655 #define IS_NULL_CMD(cmd) \
656 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
660 int num_cmds; /* total number of commands in pipe */
661 int alive_cmds; /* number of commands running (not exited) */
662 int stopped_cmds; /* number of commands alive, but stopped */
664 unsigned jobid; /* job number */
665 pid_t pgrp; /* process group ID for the job */
666 char *cmdtext; /* name of job */
668 struct command *cmds; /* array of commands in pipe */
669 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
670 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
671 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
673 typedef enum pipe_style {
679 /* Is there anything in this pipe at all? */
680 #define IS_NULL_PIPE(pi) \
681 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
683 /* This holds pointers to the various results of parsing */
684 struct parse_context {
685 /* linked list of pipes */
686 struct pipe *list_head;
687 /* last pipe (being constructed right now) */
689 /* last command in pipe (being constructed right now) */
690 struct command *command;
691 /* last redirect in command->redirects list */
692 struct redir_struct *pending_redirect;
698 smallint ctx_inverted; /* "! cmd | cmd" */
700 smallint ctx_dsemicolon; /* ";;" seen */
702 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
704 /* group we are enclosed in:
705 * example: "if pipe1; pipe2; then pipe3; fi"
706 * when we see "if" or "then", we malloc and copy current context,
707 * and make ->stack point to it. then we parse pipeN.
708 * when closing "then" / fi" / whatever is found,
709 * we move list_head into ->stack->command->group,
710 * copy ->stack into current context, and delete ->stack.
711 * (parsing of { list } and ( list ) doesn't use this method)
713 struct parse_context *stack;
717 /* On program start, environ points to initial environment.
718 * putenv adds new pointers into it, unsetenv removes them.
719 * Neither of these (de)allocates the strings.
720 * setenv allocates new strings in malloc space and does putenv,
721 * and thus setenv is unusable (leaky) for shell's purposes */
722 #define setenv(...) setenv_is_leaky_dont_use()
724 struct variable *next;
725 char *varstr; /* points to "name=" portion */
726 #if ENABLE_HUSH_LOCAL
727 unsigned func_nest_level;
729 int max_len; /* if > 0, name is part of initial env; else name is malloced */
730 smallint flg_export; /* putenv should be done on this var */
731 smallint flg_read_only;
739 #if ENABLE_HUSH_FUNCTIONS
741 struct function *next;
743 struct command *parent_cmd;
746 char *body_as_string;
752 /* set -/+o OPT support. (TODO: make it optional)
753 * bash supports the following opts:
764 * interactive-comments on
782 static const char o_opt_strings[] ALIGN1 =
786 #if ENABLE_HUSH_MODE_X
794 #if ENABLE_HUSH_MODE_X
802 struct FILE_list *next;
808 /* "Globals" within this file */
809 /* Sorted roughly by size (smaller offsets == smaller code) */
811 /* interactive_fd != 0 means we are an interactive shell.
812 * If we are, then saved_tty_pgrp can also be != 0, meaning
813 * that controlling tty is available. With saved_tty_pgrp == 0,
814 * job control still works, but terminal signals
815 * (^C, ^Z, ^Y, ^\) won't work at all, and background
816 * process groups can only be created with "cmd &".
817 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
818 * to give tty to the foreground process group,
819 * and will take it back when the group is stopped (^Z)
822 #if ENABLE_HUSH_INTERACTIVE
823 /* 'interactive_fd' is a fd# open to ctty, if we have one
824 * _AND_ if we decided to act interactively */
828 # define G_interactive_fd (G.interactive_fd)
830 # define G_interactive_fd 0
832 #if ENABLE_FEATURE_EDITING
833 line_input_t *line_input_state;
838 #if ENABLE_HUSH_RANDOM_SUPPORT
844 pid_t saved_tty_pgrp;
845 struct pipe *job_list;
846 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
848 # define G_saved_tty_pgrp 0
850 /* How deeply are we in context where "set -e" is ignored */
852 /* "set -e" rules (do we follow them correctly?):
853 * Exit if pipe, list, or compound command exits with a non-zero status.
854 * Shell does not exit if failed command is part of condition in
855 * if/while, part of && or || list except the last command, any command
856 * in a pipe but the last, or if the command's return value is being
857 * inverted with !. If a compound command other than a subshell returns a
858 * non-zero status because a command failed while -e was being ignored, the
859 * shell does not exit. A trap on ERR, if set, is executed before the shell
860 * exits [ERR is a bashism].
862 * If a compound command or function executes in a context where -e is
863 * ignored, none of the commands executed within are affected by the -e
864 * setting. If a compound command or function sets -e while executing in a
865 * context where -e is ignored, that setting does not have any effect until
866 * the compound command or the command containing the function call completes.
869 char o_opt[NUM_OPT_O];
870 #if ENABLE_HUSH_MODE_X
871 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
875 smallint flag_SIGINT;
876 #if ENABLE_HUSH_LOOPS
877 smallint flag_break_continue;
879 #if ENABLE_HUSH_FUNCTIONS
880 /* 0: outside of a function (or sourced file)
881 * -1: inside of a function, ok to use return builtin
882 * 1: return is invoked, skip all till end of func
884 smallint flag_return_in_progress;
885 # define G_flag_return_in_progress (G.flag_return_in_progress)
887 # define G_flag_return_in_progress 0
889 smallint exiting; /* used to prevent EXIT trap recursion */
890 /* These four support $?, $#, and $1 */
891 smalluint last_exitcode;
892 smalluint last_bg_pid_exitcode;
894 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
895 smalluint global_args_malloced;
896 # define G_global_args_malloced (G.global_args_malloced)
898 # define G_global_args_malloced 0
900 /* how many non-NULL argv's we have. NB: $# + 1 */
904 char *argv0_for_re_execing;
906 #if ENABLE_HUSH_LOOPS
907 unsigned depth_break_continue;
908 unsigned depth_of_loop;
910 #if ENABLE_HUSH_GETOPTS
911 unsigned getopt_count;
915 struct variable *top_var;
916 char **expanded_assignments;
917 #if ENABLE_HUSH_FUNCTIONS
918 struct function *top_func;
919 # if ENABLE_HUSH_LOCAL
920 struct variable **shadowed_vars_pp;
921 unsigned func_nest_level;
924 /* Signal and trap handling */
926 unsigned count_SIGCHLD;
927 unsigned handled_SIGCHLD;
928 smallint we_have_children;
930 struct FILE_list *FILE_list;
931 /* Which signals have non-DFL handler (even with no traps set)?
932 * Set at the start to:
933 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
934 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
935 * The rest is cleared right before execv syscalls.
936 * Other than these two times, never modified.
938 unsigned special_sig_mask;
940 unsigned fatal_sig_mask;
941 # define G_fatal_sig_mask (G.fatal_sig_mask)
943 # define G_fatal_sig_mask 0
946 char **traps; /* char *traps[NSIG] */
947 # define G_traps G.traps
949 # define G_traps ((char**)NULL)
951 sigset_t pending_set;
952 #if ENABLE_HUSH_MEMLEAK
953 unsigned long memleak_value;
959 #if ENABLE_FEATURE_EDITING
960 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
963 #define G (*ptr_to_globals)
964 /* Not #defining name to G.name - this quickly gets unwieldy
965 * (too many defines). Also, I actually prefer to see when a variable
966 * is global, thus "G." prefix is a useful hint */
967 #define INIT_G() do { \
968 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
969 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
970 sigfillset(&G.sa.sa_mask); \
971 G.sa.sa_flags = SA_RESTART; \
975 /* Function prototypes for builtins */
976 static int builtin_cd(char **argv) FAST_FUNC;
978 static int builtin_echo(char **argv) FAST_FUNC;
980 static int builtin_eval(char **argv) FAST_FUNC;
981 static int builtin_exec(char **argv) FAST_FUNC;
982 static int builtin_exit(char **argv) FAST_FUNC;
983 #if ENABLE_HUSH_EXPORT
984 static int builtin_export(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_READONLY
987 static int builtin_readonly(char **argv) FAST_FUNC;
990 static int builtin_fg_bg(char **argv) FAST_FUNC;
991 static int builtin_jobs(char **argv) FAST_FUNC;
993 #if ENABLE_HUSH_GETOPTS
994 static int builtin_getopts(char **argv) FAST_FUNC;
997 static int builtin_help(char **argv) FAST_FUNC;
999 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1000 static int builtin_history(char **argv) FAST_FUNC;
1002 #if ENABLE_HUSH_LOCAL
1003 static int builtin_local(char **argv) FAST_FUNC;
1005 #if ENABLE_HUSH_MEMLEAK
1006 static int builtin_memleak(char **argv) FAST_FUNC;
1008 #if ENABLE_HUSH_PRINTF
1009 static int builtin_printf(char **argv) FAST_FUNC;
1011 static int builtin_pwd(char **argv) FAST_FUNC;
1012 #if ENABLE_HUSH_READ
1013 static int builtin_read(char **argv) FAST_FUNC;
1016 static int builtin_set(char **argv) FAST_FUNC;
1018 static int builtin_shift(char **argv) FAST_FUNC;
1019 static int builtin_source(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_TEST || BASH_TEST2
1021 static int builtin_test(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_TRAP
1024 static int builtin_trap(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_TYPE
1027 static int builtin_type(char **argv) FAST_FUNC;
1029 #if ENABLE_HUSH_TIMES
1030 static int builtin_times(char **argv) FAST_FUNC;
1032 static int builtin_true(char **argv) FAST_FUNC;
1033 #if ENABLE_HUSH_UMASK
1034 static int builtin_umask(char **argv) FAST_FUNC;
1036 #if ENABLE_HUSH_UNSET
1037 static int builtin_unset(char **argv) FAST_FUNC;
1039 #if ENABLE_HUSH_KILL
1040 static int builtin_kill(char **argv) FAST_FUNC;
1042 #if ENABLE_HUSH_WAIT
1043 static int builtin_wait(char **argv) FAST_FUNC;
1045 #if ENABLE_HUSH_LOOPS
1046 static int builtin_break(char **argv) FAST_FUNC;
1047 static int builtin_continue(char **argv) FAST_FUNC;
1049 #if ENABLE_HUSH_FUNCTIONS
1050 static int builtin_return(char **argv) FAST_FUNC;
1053 /* Table of built-in functions. They can be forked or not, depending on
1054 * context: within pipes, they fork. As simple commands, they do not.
1055 * When used in non-forking context, they can change global variables
1056 * in the parent shell process. If forked, of course they cannot.
1057 * For example, 'unset foo | whatever' will parse and run, but foo will
1058 * still be set at the end. */
1059 struct built_in_command {
1061 int (*b_function)(char **argv) FAST_FUNC;
1062 #if ENABLE_HUSH_HELP
1063 const char *b_descr;
1064 # define BLTIN(cmd, func, help) { cmd, func, help }
1066 # define BLTIN(cmd, func, help) { cmd, func }
1070 static const struct built_in_command bltins1[] = {
1071 BLTIN("." , builtin_source , "Run commands in file"),
1072 BLTIN(":" , builtin_true , NULL),
1074 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1076 #if ENABLE_HUSH_LOOPS
1077 BLTIN("break" , builtin_break , "Exit loop"),
1079 BLTIN("cd" , builtin_cd , "Change directory"),
1080 #if ENABLE_HUSH_LOOPS
1081 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1083 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1084 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1085 BLTIN("exit" , builtin_exit , NULL),
1086 #if ENABLE_HUSH_EXPORT
1087 BLTIN("export" , builtin_export , "Set environment variables"),
1090 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1092 #if ENABLE_HUSH_GETOPTS
1093 BLTIN("getopts" , builtin_getopts , NULL),
1095 #if ENABLE_HUSH_HELP
1096 BLTIN("help" , builtin_help , NULL),
1098 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1099 BLTIN("history" , builtin_history , "Show history"),
1102 BLTIN("jobs" , builtin_jobs , "List jobs"),
1104 #if ENABLE_HUSH_KILL
1105 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1107 #if ENABLE_HUSH_LOCAL
1108 BLTIN("local" , builtin_local , "Set local variables"),
1110 #if ENABLE_HUSH_MEMLEAK
1111 BLTIN("memleak" , builtin_memleak , NULL),
1113 #if ENABLE_HUSH_READ
1114 BLTIN("read" , builtin_read , "Input into variable"),
1116 #if ENABLE_HUSH_READONLY
1117 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1119 #if ENABLE_HUSH_FUNCTIONS
1120 BLTIN("return" , builtin_return , "Return from function"),
1123 BLTIN("set" , builtin_set , "Set positional parameters"),
1125 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1127 BLTIN("source" , builtin_source , NULL),
1129 #if ENABLE_HUSH_TIMES
1130 BLTIN("times" , builtin_times , NULL),
1132 #if ENABLE_HUSH_TRAP
1133 BLTIN("trap" , builtin_trap , "Trap signals"),
1135 BLTIN("true" , builtin_true , NULL),
1136 #if ENABLE_HUSH_TYPE
1137 BLTIN("type" , builtin_type , "Show command type"),
1139 #if ENABLE_HUSH_ULIMIT
1140 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1142 #if ENABLE_HUSH_UMASK
1143 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1145 #if ENABLE_HUSH_UNSET
1146 BLTIN("unset" , builtin_unset , "Unset variables"),
1148 #if ENABLE_HUSH_WAIT
1149 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1152 /* These builtins won't be used if we are on NOMMU and need to re-exec
1153 * (it's cheaper to run an external program in this case):
1155 static const struct built_in_command bltins2[] = {
1156 #if ENABLE_HUSH_TEST
1157 BLTIN("[" , builtin_test , NULL),
1160 BLTIN("[[" , builtin_test , NULL),
1162 #if ENABLE_HUSH_ECHO
1163 BLTIN("echo" , builtin_echo , NULL),
1165 #if ENABLE_HUSH_PRINTF
1166 BLTIN("printf" , builtin_printf , NULL),
1168 BLTIN("pwd" , builtin_pwd , NULL),
1169 #if ENABLE_HUSH_TEST
1170 BLTIN("test" , builtin_test , NULL),
1178 /* prevent disasters with G.debug_indent < 0 */
1179 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1180 # define debug_enter() (G.debug_indent++)
1181 # define debug_leave() (G.debug_indent--)
1183 # define indent() ((void)0)
1184 # define debug_enter() ((void)0)
1185 # define debug_leave() ((void)0)
1188 #ifndef debug_printf
1189 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1192 #ifndef debug_printf_parse
1193 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1196 #ifndef debug_printf_exec
1197 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1200 #ifndef debug_printf_env
1201 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1204 #ifndef debug_printf_jobs
1205 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1206 # define DEBUG_JOBS 1
1208 # define DEBUG_JOBS 0
1211 #ifndef debug_printf_expand
1212 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1213 # define DEBUG_EXPAND 1
1215 # define DEBUG_EXPAND 0
1218 #ifndef debug_printf_varexp
1219 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1222 #ifndef debug_printf_glob
1223 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1224 # define DEBUG_GLOB 1
1226 # define DEBUG_GLOB 0
1229 #ifndef debug_printf_redir
1230 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1233 #ifndef debug_printf_list
1234 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1237 #ifndef debug_printf_subst
1238 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1241 #ifndef debug_printf_clean
1242 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1243 # define DEBUG_CLEAN 1
1245 # define DEBUG_CLEAN 0
1249 static void debug_print_strings(const char *prefix, char **vv)
1252 fdprintf(2, "%s:\n", prefix);
1254 fdprintf(2, " '%s'\n", *vv++);
1257 # define debug_print_strings(prefix, vv) ((void)0)
1261 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1264 static void *xxmalloc(int lineno, size_t size)
1266 void *ptr = xmalloc((size + 0xff) & ~0xff);
1267 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1270 static void *xxrealloc(int lineno, void *ptr, size_t size)
1272 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1273 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1276 static char *xxstrdup(int lineno, const char *str)
1278 char *ptr = xstrdup(str);
1279 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1282 static void xxfree(void *ptr)
1284 fdprintf(2, "free %p\n", ptr);
1287 # define xmalloc(s) xxmalloc(__LINE__, s)
1288 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1289 # define xstrdup(s) xxstrdup(__LINE__, s)
1290 # define free(p) xxfree(p)
1294 /* Syntax and runtime errors. They always abort scripts.
1295 * In interactive use they usually discard unparsed and/or unexecuted commands
1296 * and return to the prompt.
1297 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1300 # define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__)
1301 # define syntax_error(lineno, msg) syntax_error(msg)
1302 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1303 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1304 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1305 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1308 static void die_if_script(void)
1310 if (!G_interactive_fd) {
1311 if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
1312 xfunc_error_retval = G.last_exitcode;
1317 static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
1322 bb_error_msg("hush.c:%u", lineno);
1325 bb_verror_msg(fmt, p, NULL);
1330 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1333 bb_error_msg("syntax error: %s", msg);
1335 bb_error_msg("syntax error");
1339 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1341 bb_error_msg("syntax error at '%s'", msg);
1345 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1347 bb_error_msg("syntax error: unterminated %s", s);
1348 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
1352 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1354 char msg[2] = { ch, '\0' };
1355 syntax_error_unterm_str(lineno, msg);
1358 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1364 bb_error_msg("hush.c:%u", lineno);
1366 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1371 # undef msg_and_die_if_script
1372 # undef syntax_error
1373 # undef syntax_error_at
1374 # undef syntax_error_unterm_ch
1375 # undef syntax_error_unterm_str
1376 # undef syntax_error_unexpected_ch
1378 # define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
1379 # define syntax_error(msg) syntax_error(__LINE__, msg)
1380 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1381 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1382 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1383 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1387 #if ENABLE_HUSH_INTERACTIVE
1388 static void cmdedit_update_prompt(void);
1390 # define cmdedit_update_prompt() ((void)0)
1394 /* Utility functions
1396 /* Replace each \x with x in place, return ptr past NUL. */
1397 static char *unbackslash(char *src)
1399 char *dst = src = strchrnul(src, '\\');
1403 if ((*dst++ = *src++) == '\0')
1409 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1430 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1431 v[count1 + count2] = NULL;
1434 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1438 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1440 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1441 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1444 #define add_strings_to_strings(strings, add, need_to_dup) \
1445 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1448 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1449 static char **add_string_to_strings(char **strings, char *add)
1454 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1457 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1459 char **ptr = add_string_to_strings(strings, add);
1460 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1463 #define add_string_to_strings(strings, add) \
1464 xx_add_string_to_strings(__LINE__, strings, add)
1467 static void free_strings(char **strings)
1481 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1485 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1495 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1499 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1505 /* fd was not open? */
1510 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1511 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1517 /* Manipulating the list of open FILEs */
1518 static FILE *remember_FILE(FILE *fp)
1521 struct FILE_list *n = xmalloc(sizeof(*n));
1522 n->next = G.FILE_list;
1526 close_on_exec_on(n->fd);
1530 static void fclose_and_forget(FILE *fp)
1532 struct FILE_list **pp = &G.FILE_list;
1534 struct FILE_list *cur = *pp;
1535 if (cur->fp == fp) {
1544 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1546 struct FILE_list *fl = G.FILE_list;
1549 /* We use it only on script files, they are all CLOEXEC */
1550 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1551 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1558 static void restore_redirected_FILEs(void)
1560 struct FILE_list *fl = G.FILE_list;
1562 int should_be = fileno(fl->fp);
1563 if (fl->fd != should_be) {
1564 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1565 xmove_fd(fl->fd, should_be);
1571 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1572 static void close_all_FILE_list(void)
1574 struct FILE_list *fl = G.FILE_list;
1576 /* fclose would also free FILE object.
1577 * It is disastrous if we share memory with a vforked parent.
1578 * I'm not sure we never come here after vfork.
1579 * Therefore just close fd, nothing more.
1581 /*fclose(fl->fp); - unsafe */
1587 static int fd_in_FILEs(int fd)
1589 struct FILE_list *fl = G.FILE_list;
1599 /* Helpers for setting new $n and restoring them back
1601 typedef struct save_arg_t {
1605 IF_HUSH_SET(smallint sv_g_malloced;)
1608 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1610 sv->sv_argv0 = argv[0];
1611 sv->sv_g_argv = G.global_argv;
1612 sv->sv_g_argc = G.global_argc;
1613 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1615 argv[0] = G.global_argv[0]; /* retain $0 */
1616 G.global_argv = argv;
1617 IF_HUSH_SET(G.global_args_malloced = 0;)
1619 G.global_argc = 1 + string_array_len(argv + 1);
1622 static void restore_G_args(save_arg_t *sv, char **argv)
1625 if (G.global_args_malloced) {
1626 /* someone ran "set -- arg1 arg2 ...", undo */
1627 char **pp = G.global_argv;
1628 while (*++pp) /* note: does not free $0 */
1630 free(G.global_argv);
1633 argv[0] = sv->sv_argv0;
1634 G.global_argv = sv->sv_g_argv;
1635 G.global_argc = sv->sv_g_argc;
1636 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1640 /* Basic theory of signal handling in shell
1641 * ========================================
1642 * This does not describe what hush does, rather, it is current understanding
1643 * what it _should_ do. If it doesn't, it's a bug.
1644 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1646 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1647 * is finished or backgrounded. It is the same in interactive and
1648 * non-interactive shells, and is the same regardless of whether
1649 * a user trap handler is installed or a shell special one is in effect.
1650 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1651 * backgrounds (i.e. stops) or kills all members of currently running
1654 * Wait builtin is interruptible by signals for which user trap is set
1655 * or by SIGINT in interactive shell.
1657 * Trap handlers will execute even within trap handlers. (right?)
1659 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1660 * except for handlers set to '' (empty string).
1662 * If job control is off, backgrounded commands ("cmd &")
1663 * have SIGINT, SIGQUIT set to SIG_IGN.
1665 * Commands which are run in command substitution ("`cmd`")
1666 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1668 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1669 * by the shell from its parent.
1671 * Signals which differ from SIG_DFL action
1672 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1675 * SIGTERM (interactive): ignore
1676 * SIGHUP (interactive):
1677 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1678 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1679 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1680 * that all pipe members are stopped. Try this in bash:
1681 * while :; do :; done - ^Z does not background it
1682 * (while :; do :; done) - ^Z backgrounds it
1683 * SIGINT (interactive): wait for last pipe, ignore the rest
1684 * of the command line, show prompt. NB: ^C does not send SIGINT
1685 * to interactive shell while shell is waiting for a pipe,
1686 * since shell is bg'ed (is not in foreground process group).
1687 * Example 1: this waits 5 sec, but does not execute ls:
1688 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1689 * Example 2: this does not wait and does not execute ls:
1690 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1691 * Example 3: this does not wait 5 sec, but executes ls:
1692 * "sleep 5; ls -l" + press ^C
1693 * Example 4: this does not wait and does not execute ls:
1694 * "sleep 5 & wait; ls -l" + press ^C
1696 * (What happens to signals which are IGN on shell start?)
1697 * (What happens with signal mask on shell start?)
1699 * Old implementation
1700 * ==================
1701 * We use in-kernel pending signal mask to determine which signals were sent.
1702 * We block all signals which we don't want to take action immediately,
1703 * i.e. we block all signals which need to have special handling as described
1704 * above, and all signals which have traps set.
1705 * After each pipe execution, we extract any pending signals via sigtimedwait()
1708 * unsigned special_sig_mask: a mask of such "special" signals
1709 * sigset_t blocked_set: current blocked signal set
1712 * clear bit in blocked_set unless it is also in special_sig_mask
1713 * "trap 'cmd' SIGxxx":
1714 * set bit in blocked_set (even if 'cmd' is '')
1715 * after [v]fork, if we plan to be a shell:
1716 * unblock signals with special interactive handling
1717 * (child shell is not interactive),
1718 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1719 * after [v]fork, if we plan to exec:
1720 * POSIX says fork clears pending signal mask in child - no need to clear it.
1721 * Restore blocked signal set to one inherited by shell just prior to exec.
1723 * Note: as a result, we do not use signal handlers much. The only uses
1724 * are to count SIGCHLDs
1725 * and to restore tty pgrp on signal-induced exit.
1728 * Standard says "When a subshell is entered, traps that are not being ignored
1729 * are set to the default actions". bash interprets it so that traps which
1730 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1732 * Problem: the above approach makes it unwieldy to catch signals while
1733 * we are in read builtin, or while we read commands from stdin:
1734 * masked signals are not visible!
1736 * New implementation
1737 * ==================
1738 * We record each signal we are interested in by installing signal handler
1739 * for them - a bit like emulating kernel pending signal mask in userspace.
1740 * We are interested in: signals which need to have special handling
1741 * as described above, and all signals which have traps set.
1742 * Signals are recorded in pending_set.
1743 * After each pipe execution, we extract any pending signals
1746 * unsigned special_sig_mask: a mask of shell-special signals.
1747 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1748 * char *traps[sig] if trap for sig is set (even if it's '').
1749 * sigset_t pending_set: set of sigs we received.
1752 * if sig is in special_sig_mask, set handler back to:
1753 * record_pending_signo, or to IGN if it's a tty stop signal
1754 * if sig is in fatal_sig_mask, set handler back to sigexit.
1755 * else: set handler back to SIG_DFL
1756 * "trap 'cmd' SIGxxx":
1757 * set handler to record_pending_signo.
1759 * set handler to SIG_IGN.
1760 * after [v]fork, if we plan to be a shell:
1761 * set signals with special interactive handling to SIG_DFL
1762 * (because child shell is not interactive),
1763 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1764 * after [v]fork, if we plan to exec:
1765 * POSIX says fork clears pending signal mask in child - no need to clear it.
1767 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1768 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1771 * Standard says "When a subshell is entered, traps that are not being ignored
1772 * are set to the default actions". bash interprets it so that traps which
1773 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1776 SPECIAL_INTERACTIVE_SIGS = 0
1781 SPECIAL_JOBSTOP_SIGS = 0
1790 static void record_pending_signo(int sig)
1792 sigaddset(&G.pending_set, sig);
1793 #if ENABLE_HUSH_FAST
1794 if (sig == SIGCHLD) {
1796 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1801 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1803 struct sigaction old_sa;
1805 /* We could use signal() to install handlers... almost:
1806 * except that we need to mask ALL signals while handlers run.
1807 * I saw signal nesting in strace, race window isn't small.
1808 * SA_RESTART is also needed, but in Linux, signal()
1809 * sets SA_RESTART too.
1811 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1812 /* sigfillset(&G.sa.sa_mask); - already done */
1813 /* G.sa.sa_flags = SA_RESTART; - already done */
1814 G.sa.sa_handler = handler;
1815 sigaction(sig, &G.sa, &old_sa);
1816 return old_sa.sa_handler;
1819 static void hush_exit(int exitcode) NORETURN;
1821 static void restore_ttypgrp_and__exit(void) NORETURN;
1822 static void restore_ttypgrp_and__exit(void)
1824 /* xfunc has failed! die die die */
1825 /* no EXIT traps, this is an escape hatch! */
1827 hush_exit(xfunc_error_retval);
1832 /* Needed only on some libc:
1833 * It was observed that on exit(), fgetc'ed buffered data
1834 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1835 * With the net effect that even after fork(), not vfork(),
1836 * exit() in NOEXECed applet in "sh SCRIPT":
1837 * noexec_applet_here
1838 * echo END_OF_SCRIPT
1839 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1840 * This makes "echo END_OF_SCRIPT" executed twice.
1841 * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
1842 * and in `cmd` handling.
1843 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1845 static void fflush_and__exit(void) NORETURN;
1846 static void fflush_and__exit(void)
1849 _exit(xfunc_error_retval);
1852 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1853 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1854 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1855 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1857 /* Restores tty foreground process group, and exits.
1858 * May be called as signal handler for fatal signal
1859 * (will resend signal to itself, producing correct exit state)
1860 * or called directly with -EXITCODE.
1861 * We also call it if xfunc is exiting.
1863 static void sigexit(int sig) NORETURN;
1864 static void sigexit(int sig)
1866 /* Careful: we can end up here after [v]fork. Do not restore
1867 * tty pgrp then, only top-level shell process does that */
1868 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1869 /* Disable all signals: job control, SIGPIPE, etc.
1870 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1872 sigprocmask_allsigs(SIG_BLOCK);
1873 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1876 /* Not a signal, just exit */
1880 kill_myself_with_sig(sig); /* does not return */
1884 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1885 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1889 static sighandler_t pick_sighandler(unsigned sig)
1891 sighandler_t handler = SIG_DFL;
1892 if (sig < sizeof(unsigned)*8) {
1893 unsigned sigmask = (1 << sig);
1897 if (G_fatal_sig_mask & sigmask)
1901 /* sig has special handling? */
1902 if (G.special_sig_mask & sigmask) {
1903 handler = record_pending_signo;
1904 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1905 * in order to ignore them: they will be raised
1906 * in an endless loop when we try to do some
1907 * terminal ioctls! We do have to _ignore_ these.
1909 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1916 /* Restores tty foreground process group, and exits. */
1917 static void hush_exit(int exitcode)
1919 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1920 save_history(G.line_input_state);
1924 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1926 /* argv[0] is unused */
1927 argv[1] = G_traps[0];
1929 G.exiting = 1; /* prevent EXIT trap recursion */
1930 /* Note: G_traps[0] is not cleared!
1931 * "trap" will still show it, if executed
1936 #if ENABLE_FEATURE_CLEAN_UP
1938 struct variable *cur_var;
1939 if (G.cwd != bb_msg_unknown)
1941 cur_var = G.top_var;
1943 struct variable *tmp = cur_var;
1944 if (!cur_var->max_len)
1945 free(cur_var->varstr);
1946 cur_var = cur_var->next;
1954 sigexit(- (exitcode & 0xff));
1961 //TODO: return a mask of ALL handled sigs?
1962 static int check_and_run_traps(void)
1969 if (sigisemptyset(&G.pending_set))
1974 if (sigismember(&G.pending_set, sig)) {
1975 sigdelset(&G.pending_set, sig);
1978 } while (sig < NSIG);
1981 if (G_traps && G_traps[sig]) {
1982 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1983 if (G_traps[sig][0]) {
1984 /* We have user-defined handler */
1985 smalluint save_rcode;
1987 /* argv[0] is unused */
1988 argv[1] = G_traps[sig];
1990 save_rcode = G.last_exitcode;
1992 //FIXME: shouldn't it be set to 128 + sig instead?
1993 G.last_exitcode = save_rcode;
1995 } /* else: "" trap, ignoring signal */
1998 /* not a trap: special action */
2001 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
2007 //TODO: why are we doing this? ash and dash don't do this,
2008 //they have no handler for SIGHUP at all,
2009 //they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
2011 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
2012 /* bash is observed to signal whole process groups,
2013 * not individual processes */
2014 for (job = G.job_list; job; job = job->next) {
2017 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
2018 if (kill(- job->pgrp, SIGHUP) == 0)
2019 kill(- job->pgrp, SIGCONT);
2024 #if ENABLE_HUSH_FAST
2026 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
2028 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2030 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2031 * This simplifies wait builtin a bit.
2035 default: /* ignored: */
2036 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
2037 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
2039 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2040 * Example: wait is not interrupted by TERM
2041 * in interactive shell, because TERM is ignored.
2050 static const char *get_cwd(int force)
2052 if (force || G.cwd == NULL) {
2053 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2054 * we must not try to free(bb_msg_unknown) */
2055 if (G.cwd == bb_msg_unknown)
2057 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2059 G.cwd = bb_msg_unknown;
2066 * Shell and environment variable support
2068 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2070 struct variable **pp;
2071 struct variable *cur;
2074 while ((cur = *pp) != NULL) {
2075 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2082 static const char* FAST_FUNC get_local_var_value(const char *name)
2084 struct variable **vpp;
2085 unsigned len = strlen(name);
2087 if (G.expanded_assignments) {
2088 char **cpp = G.expanded_assignments;
2091 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2092 return cp + len + 1;
2097 vpp = get_ptr_to_local_var(name, len);
2099 return (*vpp)->varstr + len + 1;
2101 if (strcmp(name, "PPID") == 0)
2102 return utoa(G.root_ppid);
2103 // bash compat: UID? EUID?
2104 #if ENABLE_HUSH_RANDOM_SUPPORT
2105 if (strcmp(name, "RANDOM") == 0)
2106 return utoa(next_random(&G.random_gen));
2111 /* str holds "NAME=VAL" and is expected to be malloced.
2112 * We take ownership of it.
2114 #define SETFLAG_EXPORT (1 << 0)
2115 #define SETFLAG_UNEXPORT (1 << 1)
2116 #define SETFLAG_MAKE_RO (1 << 2)
2117 #define SETFLAG_LOCAL_SHIFT 3
2118 static int set_local_var(char *str, unsigned flags)
2120 struct variable **var_pp;
2121 struct variable *cur;
2122 char *free_me = NULL;
2125 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2127 eq_sign = strchr(str, '=');
2128 if (!eq_sign) { /* not expected to ever happen? */
2133 name_len = eq_sign - str + 1; /* including '=' */
2134 var_pp = &G.top_var;
2135 while ((cur = *var_pp) != NULL) {
2136 if (strncmp(cur->varstr, str, name_len) != 0) {
2137 var_pp = &cur->next;
2141 /* We found an existing var with this name */
2142 if (cur->flg_read_only) {
2143 bb_error_msg("%s: readonly variable", str);
2145 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2146 //but export per se succeeds (does put the var in env). We don't mimic that.
2149 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2150 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2155 #if ENABLE_HUSH_LOCAL
2156 if (cur->func_nest_level < local_lvl) {
2157 /* New variable is declared as local,
2158 * and existing one is global, or local
2159 * from enclosing function.
2160 * Remove and save old one: */
2161 *var_pp = cur->next;
2162 cur->next = *G.shadowed_vars_pp;
2163 *G.shadowed_vars_pp = cur;
2164 /* bash 3.2.33(1) and exported vars:
2166 * # f() { local z=a; env | grep ^z; }
2172 if (cur->flg_export)
2173 flags |= SETFLAG_EXPORT;
2177 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2182 if (cur->max_len != 0) {
2183 if (cur->max_len >= strlen(str)) {
2184 /* This one is from startup env, reuse space */
2185 strcpy(cur->varstr, str);
2190 goto set_str_and_exp;
2192 /* max_len == 0 signifies "malloced" var, which we can
2193 * (and have to) free. But we can't free(cur->varstr) here:
2194 * if cur->flg_export is 1, it is in the environment.
2195 * We should either unsetenv+free, or wait until putenv,
2196 * then putenv(new)+free(old).
2198 free_me = cur->varstr;
2199 goto set_str_and_exp;
2202 /* Not found - create new variable struct */
2203 cur = xzalloc(sizeof(*cur));
2204 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2205 cur->next = *var_pp;
2211 #if !BB_MMU || ENABLE_HUSH_READONLY
2212 if (flags & SETFLAG_MAKE_RO) {
2213 cur->flg_read_only = 1;
2216 if (flags & SETFLAG_EXPORT)
2217 cur->flg_export = 1;
2218 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2219 cmdedit_update_prompt();
2220 #if ENABLE_HUSH_GETOPTS
2221 /* defoptindvar is a "OPTIND=..." constant string */
2222 if (strncmp(cur->varstr, defoptindvar, 7) == 0)
2225 if (cur->flg_export) {
2226 if (flags & SETFLAG_UNEXPORT) {
2227 cur->flg_export = 0;
2228 /* unsetenv was already done */
2231 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2232 i = putenv(cur->varstr);
2233 /* only now we can free old exported malloced string */
2242 /* Used at startup and after each cd */
2243 static void set_pwd_var(unsigned flag)
2245 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2248 static int unset_local_var_len(const char *name, int name_len)
2250 struct variable *cur;
2251 struct variable **var_pp;
2254 return EXIT_SUCCESS;
2255 #if ENABLE_HUSH_GETOPTS
2256 if (name_len == 6 && strncmp(name, "OPTIND", 6) == 0)
2259 var_pp = &G.top_var;
2260 while ((cur = *var_pp) != NULL) {
2261 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2262 if (cur->flg_read_only) {
2263 bb_error_msg("%s: readonly variable", name);
2264 return EXIT_FAILURE;
2266 *var_pp = cur->next;
2267 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2268 bb_unsetenv(cur->varstr);
2269 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2270 cmdedit_update_prompt();
2274 return EXIT_SUCCESS;
2276 var_pp = &cur->next;
2278 return EXIT_SUCCESS;
2281 #if ENABLE_HUSH_UNSET || ENABLE_HUSH_GETOPTS
2282 static int unset_local_var(const char *name)
2284 return unset_local_var_len(name, strlen(name));
2288 static void unset_vars(char **strings)
2296 const char *eq = strchrnul(*v, '=');
2297 unset_local_var_len(*v, (int)(eq - *v));
2303 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ || ENABLE_HUSH_GETOPTS
2304 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2306 char *var = xasprintf("%s=%s", name, val);
2307 set_local_var(var, /*flag:*/ 0);
2313 * Helpers for "var1=val1 var2=val2 cmd" feature
2315 static void add_vars(struct variable *var)
2317 struct variable *next;
2321 var->next = G.top_var;
2323 if (var->flg_export) {
2324 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2325 putenv(var->varstr);
2327 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2333 static struct variable *set_vars_and_save_old(char **strings)
2336 struct variable *old = NULL;
2342 struct variable *var_p;
2343 struct variable **var_pp;
2346 eq = strchr(*s, '=');
2348 var_pp = get_ptr_to_local_var(*s, eq - *s);
2351 if (var_p->flg_read_only) {
2353 bb_error_msg("%s: readonly variable", *s);
2355 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2356 * If VAR is readonly, leaving it in the list
2357 * after asssignment error (msg above)
2358 * causes doubled error message later, on unset.
2360 debug_printf_env("removing/freeing '%s' element\n", *s);
2363 do { *p = p[1]; p++; } while (*p);
2366 /* Remove variable from global linked list */
2367 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2368 *var_pp = var_p->next;
2369 /* Add it to returned list */
2373 set_local_var(*s, SETFLAG_EXPORT);
2385 static void reinit_unicode_for_hush(void)
2387 /* Unicode support should be activated even if LANG is set
2388 * _during_ shell execution, not only if it was set when
2389 * shell was started. Therefore, re-check LANG every time:
2391 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2392 || ENABLE_UNICODE_USING_LOCALE
2394 const char *s = get_local_var_value("LC_ALL");
2395 if (!s) s = get_local_var_value("LC_CTYPE");
2396 if (!s) s = get_local_var_value("LANG");
2402 * in_str support (strings, and "strings" read from files).
2405 #if ENABLE_HUSH_INTERACTIVE
2406 /* To test correct lineedit/interactive behavior, type from command line:
2412 * It exercises a lot of corner cases.
2414 static void cmdedit_update_prompt(void)
2416 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2417 G.PS1 = get_local_var_value("PS1");
2420 G.PS2 = get_local_var_value("PS2");
2427 static const char *setup_prompt_string(int promptmode)
2429 const char *prompt_str;
2430 debug_printf("setup_prompt_string %d ", promptmode);
2431 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2432 /* Set up the prompt */
2433 if (promptmode == 0) { /* PS1 */
2435 /* bash uses $PWD value, even if it is set by user.
2436 * It uses current dir only if PWD is unset.
2437 * We always use current dir. */
2438 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2443 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2444 debug_printf("prompt_str '%s'\n", prompt_str);
2447 static int get_user_input(struct in_str *i)
2450 const char *prompt_str;
2452 prompt_str = setup_prompt_string(i->promptmode);
2453 # if ENABLE_FEATURE_EDITING
2455 reinit_unicode_for_hush();
2456 if (G.flag_SIGINT) {
2457 /* There was ^C'ed, make it look prettier: */
2461 /* buglet: SIGINT will not make new prompt to appear _at once_,
2462 * only after <Enter>. (^C works immediately) */
2463 r = read_line_input(G.line_input_state, prompt_str,
2464 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
2466 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2469 check_and_run_traps();
2470 if (r != 0 && !G.flag_SIGINT)
2472 /* ^C or SIGINT: repeat */
2473 /* bash prints ^C even on real SIGINT (non-kbd generated) */
2474 write(STDOUT_FILENO, "^C", 2);
2475 G.last_exitcode = 128 + SIGINT;
2478 /* EOF/error detected */
2480 i->peek_buf[0] = r = EOF;
2483 i->p = G.user_input_buf;
2484 return (unsigned char)*i->p++;
2488 if (i->last_char == '\0' || i->last_char == '\n') {
2489 /* Why check_and_run_traps here? Try this interactively:
2490 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2491 * $ <[enter], repeatedly...>
2492 * Without check_and_run_traps, handler never runs.
2494 check_and_run_traps();
2495 fputs(prompt_str, stdout);
2498 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2500 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2501 * no ^C masking happens during fgetc, no special code for ^C:
2502 * it generates SIGINT as usual.
2504 check_and_run_traps();
2506 G.last_exitcode = 128 + SIGINT;
2513 /* This is the magic location that prints prompts
2514 * and gets data back from the user */
2515 static int fgetc_interactive(struct in_str *i)
2518 /* If it's interactive stdin, get new line. */
2519 if (G_interactive_fd && i->file == stdin) {
2520 /* Returns first char (or EOF), the rest is in i->p[] */
2521 ch = get_user_input(i);
2522 i->promptmode = 1; /* PS2 */
2524 /* Not stdin: script file, sourced file, etc */
2525 do ch = fgetc(i->file); while (ch == '\0');
2530 static inline int fgetc_interactive(struct in_str *i)
2533 do ch = fgetc(i->file); while (ch == '\0');
2536 #endif /* INTERACTIVE */
2538 static int i_getch(struct in_str *i)
2543 /* string-based in_str */
2544 ch = (unsigned char)*i->p;
2553 /* FILE-based in_str */
2555 #if ENABLE_FEATURE_EDITING
2556 /* This can be stdin, check line editing char[] buffer */
2557 if (i->p && *i->p != '\0') {
2558 ch = (unsigned char)*i->p++;
2562 /* peek_buf[] is an int array, not char. Can contain EOF. */
2563 ch = i->peek_buf[0];
2565 int ch2 = i->peek_buf[1];
2566 i->peek_buf[0] = ch2;
2567 if (ch2 == 0) /* very likely, avoid redundant write */
2573 ch = fgetc_interactive(i);
2575 debug_printf("file_get: got '%c' %d\n", ch, ch);
2580 static int i_peek(struct in_str *i)
2585 /* string-based in_str */
2586 /* Doesn't report EOF on NUL. None of the callers care. */
2587 return (unsigned char)*i->p;
2590 /* FILE-based in_str */
2592 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2593 /* This can be stdin, check line editing char[] buffer */
2594 if (i->p && *i->p != '\0')
2595 return (unsigned char)*i->p;
2597 /* peek_buf[] is an int array, not char. Can contain EOF. */
2598 ch = i->peek_buf[0];
2602 /* Need to get a new char */
2603 ch = fgetc_interactive(i);
2604 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2606 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2607 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2613 i->peek_buf[0] = ch;
2614 /*i->peek_buf[1] = 0; - already is */
2618 /* Only ever called if i_peek() was called, and did not return EOF.
2619 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2620 * not end-of-line. Therefore we never need to read a new editing line here.
2622 static int i_peek2(struct in_str *i)
2626 /* There are two cases when i->p[] buffer exists.
2627 * (1) it's a string in_str.
2628 * (2) It's a file, and we have a saved line editing buffer.
2629 * In both cases, we know that i->p[0] exists and not NUL, and
2630 * the peek2 result is in i->p[1].
2633 return (unsigned char)i->p[1];
2635 /* Now we know it is a file-based in_str. */
2637 /* peek_buf[] is an int array, not char. Can contain EOF. */
2638 /* Is there 2nd char? */
2639 ch = i->peek_buf[1];
2641 /* We did not read it yet, get it now */
2642 do ch = fgetc(i->file); while (ch == '\0');
2643 i->peek_buf[1] = ch;
2646 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2650 static void setup_file_in_str(struct in_str *i, FILE *f)
2652 memset(i, 0, sizeof(*i));
2653 /* i->promptmode = 0; - PS1 (memset did it) */
2658 static void setup_string_in_str(struct in_str *i, const char *s)
2660 memset(i, 0, sizeof(*i));
2661 /* i->promptmode = 0; - PS1 (memset did it) */
2662 /*i->file = NULL */;
2670 #define B_CHUNK (32 * sizeof(char*))
2672 static void o_reset_to_empty_unquoted(o_string *o)
2675 o->has_quoted_part = 0;
2680 static void o_free(o_string *o)
2683 memset(o, 0, sizeof(*o));
2686 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2691 static void o_grow_by(o_string *o, int len)
2693 if (o->length + len > o->maxlen) {
2694 o->maxlen += (2 * len) | (B_CHUNK-1);
2695 o->data = xrealloc(o->data, 1 + o->maxlen);
2699 static void o_addchr(o_string *o, int ch)
2701 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2702 if (o->length < o->maxlen) {
2703 /* likely. avoid o_grow_by() call */
2705 o->data[o->length] = ch;
2707 o->data[o->length] = '\0';
2715 /* Valid only if we know o_string is not empty */
2716 static void o_delchr(o_string *o)
2719 o->data[o->length] = '\0';
2723 static void o_addblock(o_string *o, const char *str, int len)
2726 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2730 static void o_addstr(o_string *o, const char *str)
2732 o_addblock(o, str, strlen(str));
2736 static void nommu_addchr(o_string *o, int ch)
2742 # define nommu_addchr(o, str) ((void)0)
2745 static void o_addstr_with_NUL(o_string *o, const char *str)
2747 o_addblock(o, str, strlen(str) + 1);
2751 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2752 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2753 * Apparently, on unquoted $v bash still does globbing
2754 * ("v='*.txt'; echo $v" prints all .txt files),
2755 * but NOT brace expansion! Thus, there should be TWO independent
2756 * quoting mechanisms on $v expansion side: one protects
2757 * $v from brace expansion, and other additionally protects "$v" against globbing.
2758 * We have only second one.
2761 #if ENABLE_HUSH_BRACE_EXPANSION
2762 # define MAYBE_BRACES "{}"
2764 # define MAYBE_BRACES ""
2767 /* My analysis of quoting semantics tells me that state information
2768 * is associated with a destination, not a source.
2770 static void o_addqchr(o_string *o, int ch)
2773 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2778 o->data[o->length] = '\\';
2781 o->data[o->length] = ch;
2783 o->data[o->length] = '\0';
2786 static void o_addQchr(o_string *o, int ch)
2789 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2790 && strchr("*?[\\" MAYBE_BRACES, ch)
2793 o->data[o->length] = '\\';
2797 o->data[o->length] = ch;
2799 o->data[o->length] = '\0';
2802 static void o_addqblock(o_string *o, const char *str, int len)
2807 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2808 if (ordinary_cnt > len) /* paranoia */
2810 o_addblock(o, str, ordinary_cnt);
2811 if (ordinary_cnt == len)
2812 return; /* NUL is already added by o_addblock */
2813 str += ordinary_cnt;
2814 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2818 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2820 o->data[o->length] = '\\';
2824 o->data[o->length] = ch;
2827 o->data[o->length] = '\0';
2830 static void o_addQblock(o_string *o, const char *str, int len)
2832 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2833 o_addblock(o, str, len);
2836 o_addqblock(o, str, len);
2839 static void o_addQstr(o_string *o, const char *str)
2841 o_addQblock(o, str, strlen(str));
2844 /* A special kind of o_string for $VAR and `cmd` expansion.
2845 * It contains char* list[] at the beginning, which is grown in 16 element
2846 * increments. Actual string data starts at the next multiple of 16 * (char*).
2847 * list[i] contains an INDEX (int!) into this string data.
2848 * It means that if list[] needs to grow, data needs to be moved higher up
2849 * but list[i]'s need not be modified.
2850 * NB: remembering how many list[i]'s you have there is crucial.
2851 * o_finalize_list() operation post-processes this structure - calculates
2852 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2854 #if DEBUG_EXPAND || DEBUG_GLOB
2855 static void debug_print_list(const char *prefix, o_string *o, int n)
2857 char **list = (char**)o->data;
2858 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2862 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2863 prefix, list, n, string_start, o->length, o->maxlen,
2864 !!(o->o_expflags & EXP_FLAG_GLOB),
2866 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2869 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2870 o->data + (int)(uintptr_t)list[i] + string_start,
2871 o->data + (int)(uintptr_t)list[i] + string_start);
2875 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2877 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2881 # define debug_print_list(prefix, o, n) ((void)0)
2884 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2885 * in list[n] so that it points past last stored byte so far.
2886 * It returns n+1. */
2887 static int o_save_ptr_helper(o_string *o, int n)
2889 char **list = (char**)o->data;
2893 if (!o->has_empty_slot) {
2894 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2895 string_len = o->length - string_start;
2896 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2897 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2898 /* list[n] points to string_start, make space for 16 more pointers */
2899 o->maxlen += 0x10 * sizeof(list[0]);
2900 o->data = xrealloc(o->data, o->maxlen + 1);
2901 list = (char**)o->data;
2902 memmove(list + n + 0x10, list + n, string_len);
2903 o->length += 0x10 * sizeof(list[0]);
2905 debug_printf_list("list[%d]=%d string_start=%d\n",
2906 n, string_len, string_start);
2909 /* We have empty slot at list[n], reuse without growth */
2910 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2911 string_len = o->length - string_start;
2912 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2913 n, string_len, string_start);
2914 o->has_empty_slot = 0;
2916 o->has_quoted_part = 0;
2917 list[n] = (char*)(uintptr_t)string_len;
2921 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2922 static int o_get_last_ptr(o_string *o, int n)
2924 char **list = (char**)o->data;
2925 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2927 return ((int)(uintptr_t)list[n-1]) + string_start;
2930 #if ENABLE_HUSH_BRACE_EXPANSION
2931 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2932 * first, it processes even {a} (no commas), second,
2933 * I didn't manage to make it return strings when they don't match
2934 * existing files. Need to re-implement it.
2938 static int glob_needed(const char *s)
2947 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2953 /* Return pointer to next closing brace or to comma */
2954 static const char *next_brace_sub(const char *cp)
2958 while (*cp != '\0') {
2965 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2971 return *cp != '\0' ? cp : NULL;
2973 /* Recursive brace globber. Note: may garble pattern[]. */
2974 static int glob_brace(char *pattern, o_string *o, int n)
2976 char *new_pattern_buf;
2983 debug_printf_glob("glob_brace('%s')\n", pattern);
2989 if (*begin == '{') {
2990 /* Find the first sub-pattern and at the same time
2991 * find the rest after the closing brace */
2992 next = next_brace_sub(begin);
2994 /* An illegal expression */
2998 /* "{abc}" with no commas - illegal
2999 * brace expr, disregard and skip it */
3005 if (*begin == '\\' && begin[1] != '\0')
3009 debug_printf_glob("begin:%s\n", begin);
3010 debug_printf_glob("next:%s\n", next);
3012 /* Now find the end of the whole brace expression */
3014 while (*rest != '}') {
3015 rest = next_brace_sub(rest);
3017 /* An illegal expression */
3020 debug_printf_glob("rest:%s\n", rest);
3022 rest_len = strlen(++rest) + 1;
3024 /* We are sure the brace expression is well-formed */
3026 /* Allocate working buffer large enough for our work */
3027 new_pattern_buf = xmalloc(strlen(pattern));
3029 /* We have a brace expression. BEGIN points to the opening {,
3030 * NEXT points past the terminator of the first element, and REST
3031 * points past the final }. We will accumulate result names from
3032 * recursive runs for each brace alternative in the buffer using
3037 /* Construct the new glob expression */
3040 mempcpy(new_pattern_buf,
3041 /* We know the prefix for all sub-patterns */
3042 pattern, begin - pattern),
3046 /* Note: glob_brace() may garble new_pattern_buf[].
3047 * That's why we re-copy prefix every time (1st memcpy above).
3049 n = glob_brace(new_pattern_buf, o, n);
3051 /* We saw the last entry */
3055 next = next_brace_sub(next);
3057 free(new_pattern_buf);
3065 memset(&globdata, 0, sizeof(globdata));
3066 gr = glob(pattern, 0, NULL, &globdata);
3067 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3069 if (gr == GLOB_NOMATCH) {
3070 globfree(&globdata);
3071 /* NB: garbles parameter */
3072 unbackslash(pattern);
3073 o_addstr_with_NUL(o, pattern);
3074 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3075 return o_save_ptr_helper(o, n);
3077 if (gr == GLOB_NOSPACE)
3078 bb_error_msg_and_die(bb_msg_memory_exhausted);
3079 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3080 * but we didn't specify it. Paranoia again. */
3081 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3083 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3084 char **argv = globdata.gl_pathv;
3086 o_addstr_with_NUL(o, *argv);
3087 n = o_save_ptr_helper(o, n);
3093 globfree(&globdata);
3097 /* Performs globbing on last list[],
3098 * saving each result as a new list[].
3100 static int perform_glob(o_string *o, int n)
3102 char *pattern, *copy;
3104 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3106 return o_save_ptr_helper(o, n);
3107 pattern = o->data + o_get_last_ptr(o, n);
3108 debug_printf_glob("glob pattern '%s'\n", pattern);
3109 if (!glob_needed(pattern)) {
3110 /* unbackslash last string in o in place, fix length */
3111 o->length = unbackslash(pattern) - o->data;
3112 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3113 return o_save_ptr_helper(o, n);
3116 copy = xstrdup(pattern);
3117 /* "forget" pattern in o */
3118 o->length = pattern - o->data;
3119 n = glob_brace(copy, o, n);
3122 debug_print_list("perform_glob returning", o, n);
3126 #else /* !HUSH_BRACE_EXPANSION */
3129 static int glob_needed(const char *s)
3138 if (*s == '*' || *s == '[' || *s == '?')
3144 /* Performs globbing on last list[],
3145 * saving each result as a new list[].
3147 static int perform_glob(o_string *o, int n)
3153 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3155 return o_save_ptr_helper(o, n);
3156 pattern = o->data + o_get_last_ptr(o, n);
3157 debug_printf_glob("glob pattern '%s'\n", pattern);
3158 if (!glob_needed(pattern)) {
3160 /* unbackslash last string in o in place, fix length */
3161 o->length = unbackslash(pattern) - o->data;
3162 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3163 return o_save_ptr_helper(o, n);
3166 memset(&globdata, 0, sizeof(globdata));
3167 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3168 * If we glob "*.\*" and don't find anything, we need
3169 * to fall back to using literal "*.*", but GLOB_NOCHECK
3170 * will return "*.\*"!
3172 gr = glob(pattern, 0, NULL, &globdata);
3173 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3175 if (gr == GLOB_NOMATCH) {
3176 globfree(&globdata);
3179 if (gr == GLOB_NOSPACE)
3180 bb_error_msg_and_die(bb_msg_memory_exhausted);
3181 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3182 * but we didn't specify it. Paranoia again. */
3183 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3185 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3186 char **argv = globdata.gl_pathv;
3187 /* "forget" pattern in o */
3188 o->length = pattern - o->data;
3190 o_addstr_with_NUL(o, *argv);
3191 n = o_save_ptr_helper(o, n);
3197 globfree(&globdata);
3199 debug_print_list("perform_glob returning", o, n);
3203 #endif /* !HUSH_BRACE_EXPANSION */
3205 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3206 * Otherwise, just finish current list[] and start new */
3207 static int o_save_ptr(o_string *o, int n)
3209 if (o->o_expflags & EXP_FLAG_GLOB) {
3210 /* If o->has_empty_slot, list[n] was already globbed
3211 * (if it was requested back then when it was filled)
3212 * so don't do that again! */
3213 if (!o->has_empty_slot)
3214 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3216 return o_save_ptr_helper(o, n);
3219 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3220 static char **o_finalize_list(o_string *o, int n)
3225 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3227 debug_print_list("finalized", o, n);
3228 debug_printf_expand("finalized n:%d\n", n);
3229 list = (char**)o->data;
3230 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3234 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3239 static void free_pipe_list(struct pipe *pi);
3241 /* Returns pi->next - next pipe in the list */
3242 static struct pipe *free_pipe(struct pipe *pi)
3247 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3248 for (i = 0; i < pi->num_cmds; i++) {
3249 struct command *command;
3250 struct redir_struct *r, *rnext;
3252 command = &pi->cmds[i];
3253 debug_printf_clean(" command %d:\n", i);
3254 if (command->argv) {
3258 for (a = 0, p = command->argv; *p; a++, p++) {
3259 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3262 free_strings(command->argv);
3263 //command->argv = NULL;
3265 /* not "else if": on syntax error, we may have both! */
3266 if (command->group) {
3267 debug_printf_clean(" begin group (cmd_type:%d)\n",
3269 free_pipe_list(command->group);
3270 debug_printf_clean(" end group\n");
3271 //command->group = NULL;
3273 /* else is crucial here.
3274 * If group != NULL, child_func is meaningless */
3275 #if ENABLE_HUSH_FUNCTIONS
3276 else if (command->child_func) {
3277 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3278 command->child_func->parent_cmd = NULL;
3282 free(command->group_as_string);
3283 //command->group_as_string = NULL;
3285 for (r = command->redirects; r; r = rnext) {
3286 debug_printf_clean(" redirect %d%s",
3287 r->rd_fd, redir_table[r->rd_type].descrip);
3288 /* guard against the case >$FOO, where foo is unset or blank */
3289 if (r->rd_filename) {
3290 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3291 free(r->rd_filename);
3292 //r->rd_filename = NULL;
3294 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3298 //command->redirects = NULL;
3300 free(pi->cmds); /* children are an array, they get freed all at once */
3304 //pi->cmdtext = NULL;
3312 static void free_pipe_list(struct pipe *pi)
3316 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3318 debug_printf_clean("pipe followup code %d\n", pi->followup);
3324 /*** Parsing routines ***/
3326 #ifndef debug_print_tree
3327 static void debug_print_tree(struct pipe *pi, int lvl)
3329 static const char *const PIPE[] = {
3335 static const char *RES[] = {
3336 [RES_NONE ] = "NONE" ,
3339 [RES_THEN ] = "THEN" ,
3340 [RES_ELIF ] = "ELIF" ,
3341 [RES_ELSE ] = "ELSE" ,
3344 # if ENABLE_HUSH_LOOPS
3345 [RES_FOR ] = "FOR" ,
3346 [RES_WHILE] = "WHILE",
3347 [RES_UNTIL] = "UNTIL",
3349 [RES_DONE ] = "DONE" ,
3351 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3354 # if ENABLE_HUSH_CASE
3355 [RES_CASE ] = "CASE" ,
3356 [RES_CASE_IN ] = "CASE_IN" ,
3357 [RES_MATCH] = "MATCH",
3358 [RES_CASE_BODY] = "CASE_BODY",
3359 [RES_ESAC ] = "ESAC" ,
3361 [RES_XXXX ] = "XXXX" ,
3362 [RES_SNTX ] = "SNTX" ,
3364 static const char *const CMDTYPE[] = {
3368 # if ENABLE_HUSH_FUNCTIONS
3377 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3378 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3380 while (prn < pi->num_cmds) {
3381 struct command *command = &pi->cmds[prn];
3382 char **argv = command->argv;
3384 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3386 command->assignment_cnt);
3387 if (command->group) {
3388 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3389 CMDTYPE[command->cmd_type],
3392 , " group_as_string:", command->group_as_string
3397 debug_print_tree(command->group, lvl+1);
3401 if (argv) while (*argv) {
3402 fdprintf(2, " '%s'", *argv);
3412 #endif /* debug_print_tree */
3414 static struct pipe *new_pipe(void)
3417 pi = xzalloc(sizeof(struct pipe));
3418 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3422 /* Command (member of a pipe) is complete, or we start a new pipe
3423 * if ctx->command is NULL.
3424 * No errors possible here.
3426 static int done_command(struct parse_context *ctx)
3428 /* The command is really already in the pipe structure, so
3429 * advance the pipe counter and make a new, null command. */
3430 struct pipe *pi = ctx->pipe;
3431 struct command *command = ctx->command;
3433 #if 0 /* Instead we emit error message at run time */
3434 if (ctx->pending_redirect) {
3435 /* For example, "cmd >" (no filename to redirect to) */
3436 syntax_error("invalid redirect");
3437 ctx->pending_redirect = NULL;
3442 if (IS_NULL_CMD(command)) {
3443 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3447 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3448 //debug_print_tree(ctx->list_head, 20);
3450 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3453 /* Only real trickiness here is that the uncommitted
3454 * command structure is not counted in pi->num_cmds. */
3455 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3456 ctx->command = command = &pi->cmds[pi->num_cmds];
3458 memset(command, 0, sizeof(*command));
3459 return pi->num_cmds; /* used only for 0/nonzero check */
3462 static void done_pipe(struct parse_context *ctx, pipe_style type)
3466 debug_printf_parse("done_pipe entered, followup %d\n", type);
3467 /* Close previous command */
3468 not_null = done_command(ctx);
3470 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3471 ctx->ctx_inverted = 0;
3472 ctx->pipe->res_word = ctx->ctx_res_w;
3474 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3475 /* Necessary since && and || have precedence over &:
3476 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3477 * in a backgrounded subshell.
3480 struct command *command;
3482 /* Is this actually this construct, all pipes end with && or ||? */
3483 pi = ctx->list_head;
3484 while (pi != ctx->pipe) {
3485 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3490 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3491 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3492 pi = xzalloc(sizeof(*pi));
3493 pi->followup = PIPE_BG;
3495 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3496 command = &pi->cmds[0];
3497 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3498 command->cmd_type = CMD_NORMAL;
3499 command->group = ctx->list_head;
3501 command->group_as_string = xstrndup(
3502 ctx->as_string.data,
3503 ctx->as_string.length - 1 /* do not copy last char, "&" */
3506 /* Replace all pipes in ctx with one newly created */
3507 ctx->list_head = ctx->pipe = pi;
3510 ctx->pipe->followup = type;
3513 /* Without this check, even just <enter> on command line generates
3514 * tree of three NOPs (!). Which is harmless but annoying.
3515 * IOW: it is safe to do it unconditionally. */
3518 || ctx->ctx_res_w == RES_FI
3520 #if ENABLE_HUSH_LOOPS
3521 || ctx->ctx_res_w == RES_DONE
3522 || ctx->ctx_res_w == RES_FOR
3523 || ctx->ctx_res_w == RES_IN
3525 #if ENABLE_HUSH_CASE
3526 || ctx->ctx_res_w == RES_ESAC
3530 debug_printf_parse("done_pipe: adding new pipe: "
3531 "not_null:%d ctx->ctx_res_w:%d\n",
3532 not_null, ctx->ctx_res_w);
3534 ctx->pipe->next = new_p;
3536 /* RES_THEN, RES_DO etc are "sticky" -
3537 * they remain set for pipes inside if/while.
3538 * This is used to control execution.
3539 * RES_FOR and RES_IN are NOT sticky (needed to support
3540 * cases where variable or value happens to match a keyword):
3542 #if ENABLE_HUSH_LOOPS
3543 if (ctx->ctx_res_w == RES_FOR
3544 || ctx->ctx_res_w == RES_IN)
3545 ctx->ctx_res_w = RES_NONE;
3547 #if ENABLE_HUSH_CASE
3548 if (ctx->ctx_res_w == RES_MATCH)
3549 ctx->ctx_res_w = RES_CASE_BODY;
3550 if (ctx->ctx_res_w == RES_CASE)
3551 ctx->ctx_res_w = RES_CASE_IN;
3553 ctx->command = NULL; /* trick done_command below */
3554 /* Create the memory for command, roughly:
3555 * ctx->pipe->cmds = new struct command;
3556 * ctx->command = &ctx->pipe->cmds[0];
3559 //debug_print_tree(ctx->list_head, 10);
3561 debug_printf_parse("done_pipe return\n");
3564 static void initialize_context(struct parse_context *ctx)
3566 memset(ctx, 0, sizeof(*ctx));
3567 ctx->pipe = ctx->list_head = new_pipe();
3568 /* Create the memory for command, roughly:
3569 * ctx->pipe->cmds = new struct command;
3570 * ctx->command = &ctx->pipe->cmds[0];
3575 /* If a reserved word is found and processed, parse context is modified
3576 * and 1 is returned.
3579 struct reserved_combo {
3582 unsigned char assignment_flag;
3586 FLAG_END = (1 << RES_NONE ),
3588 FLAG_IF = (1 << RES_IF ),
3589 FLAG_THEN = (1 << RES_THEN ),
3590 FLAG_ELIF = (1 << RES_ELIF ),
3591 FLAG_ELSE = (1 << RES_ELSE ),
3592 FLAG_FI = (1 << RES_FI ),
3594 # if ENABLE_HUSH_LOOPS
3595 FLAG_FOR = (1 << RES_FOR ),
3596 FLAG_WHILE = (1 << RES_WHILE),
3597 FLAG_UNTIL = (1 << RES_UNTIL),
3598 FLAG_DO = (1 << RES_DO ),
3599 FLAG_DONE = (1 << RES_DONE ),
3600 FLAG_IN = (1 << RES_IN ),
3602 # if ENABLE_HUSH_CASE
3603 FLAG_MATCH = (1 << RES_MATCH),
3604 FLAG_ESAC = (1 << RES_ESAC ),
3606 FLAG_START = (1 << RES_XXXX ),
3609 static const struct reserved_combo* match_reserved_word(o_string *word)
3611 /* Mostly a list of accepted follow-up reserved words.
3612 * FLAG_END means we are done with the sequence, and are ready
3613 * to turn the compound list into a command.
3614 * FLAG_START means the word must start a new compound list.
3616 static const struct reserved_combo reserved_list[] = {
3618 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3619 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3620 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3621 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3622 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3623 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3625 # if ENABLE_HUSH_LOOPS
3626 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3627 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3628 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3629 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3630 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3631 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3633 # if ENABLE_HUSH_CASE
3634 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3635 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3638 const struct reserved_combo *r;
3640 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3641 if (strcmp(word->data, r->literal) == 0)
3646 /* Return 0: not a keyword, 1: keyword
3648 static int reserved_word(o_string *word, struct parse_context *ctx)
3650 # if ENABLE_HUSH_CASE
3651 static const struct reserved_combo reserved_match = {
3652 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3655 const struct reserved_combo *r;
3657 if (word->has_quoted_part)
3659 r = match_reserved_word(word);
3663 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3664 # if ENABLE_HUSH_CASE
3665 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3666 /* "case word IN ..." - IN part starts first MATCH part */
3667 r = &reserved_match;
3670 if (r->flag == 0) { /* '!' */
3671 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3672 syntax_error("! ! command");
3673 ctx->ctx_res_w = RES_SNTX;
3675 ctx->ctx_inverted = 1;
3678 if (r->flag & FLAG_START) {
3679 struct parse_context *old;
3681 old = xmemdup(ctx, sizeof(*ctx));
3682 debug_printf_parse("push stack %p\n", old);
3683 initialize_context(ctx);
3685 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3686 syntax_error_at(word->data);
3687 ctx->ctx_res_w = RES_SNTX;
3690 /* "{...} fi" is ok. "{...} if" is not
3692 * if { echo foo; } then { echo bar; } fi */
3693 if (ctx->command->group)
3694 done_pipe(ctx, PIPE_SEQ);
3697 ctx->ctx_res_w = r->res;
3698 ctx->old_flag = r->flag;
3699 word->o_assignment = r->assignment_flag;
3700 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3702 if (ctx->old_flag & FLAG_END) {
3703 struct parse_context *old;
3705 done_pipe(ctx, PIPE_SEQ);
3706 debug_printf_parse("pop stack %p\n", ctx->stack);
3708 old->command->group = ctx->list_head;
3709 old->command->cmd_type = CMD_NORMAL;
3711 /* At this point, the compound command's string is in
3712 * ctx->as_string... except for the leading keyword!
3713 * Consider this example: "echo a | if true; then echo a; fi"
3714 * ctx->as_string will contain "true; then echo a; fi",
3715 * with "if " remaining in old->as_string!
3719 int len = old->as_string.length;
3720 /* Concatenate halves */
3721 o_addstr(&old->as_string, ctx->as_string.data);
3722 o_free_unsafe(&ctx->as_string);
3723 /* Find where leading keyword starts in first half */
3724 str = old->as_string.data + len;
3725 if (str > old->as_string.data)
3726 str--; /* skip whitespace after keyword */
3727 while (str > old->as_string.data && isalpha(str[-1]))
3729 /* Ugh, we're done with this horrid hack */
3730 old->command->group_as_string = xstrdup(str);
3731 debug_printf_parse("pop, remembering as:'%s'\n",
3732 old->command->group_as_string);
3735 *ctx = *old; /* physical copy */
3740 #endif /* HAS_KEYWORDS */
3742 /* Word is complete, look at it and update parsing context.
3743 * Normal return is 0. Syntax errors return 1.
3744 * Note: on return, word is reset, but not o_free'd!
3746 static int done_word(o_string *word, struct parse_context *ctx)
3748 struct command *command = ctx->command;
3750 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3751 if (word->length == 0 && !word->has_quoted_part) {
3752 debug_printf_parse("done_word return 0: true null, ignored\n");
3756 if (ctx->pending_redirect) {
3757 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3758 * only if run as "bash", not "sh" */
3759 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3761 * ...the word that follows the redirection operator
3762 * shall be subjected to tilde expansion, parameter expansion,
3763 * command substitution, arithmetic expansion, and quote
3764 * removal. Pathname expansion shall not be performed
3765 * on the word by a non-interactive shell; an interactive
3766 * shell may perform it, but shall do so only when
3767 * the expansion would result in one word."
3769 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3770 /* Cater for >\file case:
3771 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3772 * Same with heredocs:
3773 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3775 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3776 unbackslash(ctx->pending_redirect->rd_filename);
3777 /* Is it <<"HEREDOC"? */
3778 if (word->has_quoted_part) {
3779 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3782 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3783 ctx->pending_redirect = NULL;
3786 # if ENABLE_HUSH_CASE
3787 if (ctx->ctx_dsemicolon
3788 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3790 /* already done when ctx_dsemicolon was set to 1: */
3791 /* ctx->ctx_res_w = RES_MATCH; */
3792 ctx->ctx_dsemicolon = 0;
3795 if (!command->argv /* if it's the first word... */
3796 # if ENABLE_HUSH_LOOPS
3797 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3798 && ctx->ctx_res_w != RES_IN
3800 # if ENABLE_HUSH_CASE
3801 && ctx->ctx_res_w != RES_CASE
3804 int reserved = reserved_word(word, ctx);
3805 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3807 o_reset_to_empty_unquoted(word);
3808 debug_printf_parse("done_word return %d\n",
3809 (ctx->ctx_res_w == RES_SNTX));
3810 return (ctx->ctx_res_w == RES_SNTX);
3813 if (strcmp(word->data, "[[") == 0) {
3814 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3820 if (command->group) {
3821 /* "{ echo foo; } echo bar" - bad */
3822 syntax_error_at(word->data);
3823 debug_printf_parse("done_word return 1: syntax error, "
3824 "groups and arglists don't mix\n");
3828 /* If this word wasn't an assignment, next ones definitely
3829 * can't be assignments. Even if they look like ones. */
3830 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3831 && word->o_assignment != WORD_IS_KEYWORD
3833 word->o_assignment = NOT_ASSIGNMENT;
3835 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3836 command->assignment_cnt++;
3837 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3839 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3840 word->o_assignment = MAYBE_ASSIGNMENT;
3842 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3843 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3844 debug_print_strings("word appended to argv", command->argv);
3847 #if ENABLE_HUSH_LOOPS
3848 if (ctx->ctx_res_w == RES_FOR) {
3849 if (word->has_quoted_part
3850 || !is_well_formed_var_name(command->argv[0], '\0')
3852 /* bash says just "not a valid identifier" */
3853 syntax_error("not a valid identifier in for");
3856 /* Force FOR to have just one word (variable name) */
3857 /* NB: basically, this makes hush see "for v in ..."
3858 * syntax as if it is "for v; in ...". FOR and IN become
3859 * two pipe structs in parse tree. */
3860 done_pipe(ctx, PIPE_SEQ);
3863 #if ENABLE_HUSH_CASE
3864 /* Force CASE to have just one word */
3865 if (ctx->ctx_res_w == RES_CASE) {
3866 done_pipe(ctx, PIPE_SEQ);
3870 o_reset_to_empty_unquoted(word);
3872 debug_printf_parse("done_word return 0\n");
3877 /* Peek ahead in the input to find out if we have a "&n" construct,
3878 * as in "2>&1", that represents duplicating a file descriptor.
3880 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3881 * REDIRFD_SYNTAX_ERR if syntax error,
3882 * REDIRFD_TO_FILE if no & was seen,
3883 * or the number found.
3886 #define parse_redir_right_fd(as_string, input) \
3887 parse_redir_right_fd(input)
3889 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3895 return REDIRFD_TO_FILE;
3897 ch = i_getch(input); /* get the & */
3898 nommu_addchr(as_string, ch);
3901 ch = i_getch(input);
3902 nommu_addchr(as_string, ch);
3903 return REDIRFD_CLOSE;
3907 while (ch != EOF && isdigit(ch)) {
3908 d = d*10 + (ch-'0');
3910 ch = i_getch(input);
3911 nommu_addchr(as_string, ch);
3916 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3918 bb_error_msg("ambiguous redirect");
3919 return REDIRFD_SYNTAX_ERR;
3922 /* Return code is 0 normal, 1 if a syntax error is detected
3924 static int parse_redirect(struct parse_context *ctx,
3927 struct in_str *input)
3929 struct command *command = ctx->command;
3930 struct redir_struct *redir;
3931 struct redir_struct **redirp;
3934 dup_num = REDIRFD_TO_FILE;
3935 if (style != REDIRECT_HEREDOC) {
3936 /* Check for a '>&1' type redirect */
3937 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3938 if (dup_num == REDIRFD_SYNTAX_ERR)
3941 int ch = i_peek(input);
3942 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3943 if (dup_num) { /* <<-... */
3944 ch = i_getch(input);
3945 nommu_addchr(&ctx->as_string, ch);
3950 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3951 int ch = i_peek(input);
3953 /* >|FILE redirect ("clobbering" >).
3954 * Since we do not support "set -o noclobber" yet,
3955 * >| and > are the same for now. Just eat |.
3957 ch = i_getch(input);
3958 nommu_addchr(&ctx->as_string, ch);
3962 /* Create a new redir_struct and append it to the linked list */
3963 redirp = &command->redirects;
3964 while ((redir = *redirp) != NULL) {
3965 redirp = &(redir->next);
3967 *redirp = redir = xzalloc(sizeof(*redir));
3968 /* redir->next = NULL; */
3969 /* redir->rd_filename = NULL; */
3970 redir->rd_type = style;
3971 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3973 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3974 redir_table[style].descrip);
3976 redir->rd_dup = dup_num;
3977 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3978 /* Erik had a check here that the file descriptor in question
3979 * is legit; I postpone that to "run time"
3980 * A "-" representation of "close me" shows up as a -3 here */
3981 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3982 redir->rd_fd, redir->rd_dup);
3984 #if 0 /* Instead we emit error message at run time */
3985 if (ctx->pending_redirect) {
3986 /* For example, "cmd > <file" */
3987 syntax_error("invalid redirect");
3990 /* Set ctx->pending_redirect, so we know what to do at the
3991 * end of the next parsed word. */
3992 ctx->pending_redirect = redir;
3997 /* If a redirect is immediately preceded by a number, that number is
3998 * supposed to tell which file descriptor to redirect. This routine
3999 * looks for such preceding numbers. In an ideal world this routine
4000 * needs to handle all the following classes of redirects...
4001 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4002 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4003 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4004 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4006 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4008 * ... If n is quoted, the number shall not be recognized as part of
4009 * the redirection expression. For example:
4011 * writes the character 2 into file a"
4012 * We are getting it right by setting ->has_quoted_part on any \<char>
4014 * A -1 return means no valid number was found,
4015 * the caller should use the appropriate default for this redirection.
4017 static int redirect_opt_num(o_string *o)
4021 if (o->data == NULL)
4023 num = bb_strtou(o->data, NULL, 10);
4024 if (errno || num < 0)
4026 o_reset_to_empty_unquoted(o);
4031 #define fetch_till_str(as_string, input, word, skip_tabs) \
4032 fetch_till_str(input, word, skip_tabs)
4034 static char *fetch_till_str(o_string *as_string,
4035 struct in_str *input,
4039 o_string heredoc = NULL_O_STRING;
4041 int prev = 0; /* not \ */
4047 ch = i_getch(input);
4049 nommu_addchr(as_string, ch);
4050 if (ch == '\n' || ch == EOF) {
4052 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4053 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4054 heredoc.data[past_EOL] = '\0';
4055 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4056 return heredoc.data;
4059 /* This is a new line.
4060 * Remember position and backslash-escaping status.
4062 o_addchr(&heredoc, ch);
4065 past_EOL = heredoc.length;
4066 /* Get 1st char of next line, possibly skipping leading tabs */
4068 ch = i_getch(input);
4070 nommu_addchr(as_string, ch);
4071 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4072 /* If this immediately ended the line,
4073 * go back to end-of-line checks.
4076 goto check_heredoc_end;
4081 o_free_unsafe(&heredoc);
4084 o_addchr(&heredoc, ch);
4085 nommu_addchr(as_string, ch);
4086 if (prev == '\\' && ch == '\\')
4087 /* Correctly handle foo\\<eol> (not a line cont.) */
4088 prev = 0; /* not \ */
4094 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4095 * and load them all. There should be exactly heredoc_cnt of them.
4097 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4099 struct pipe *pi = ctx->list_head;
4101 while (pi && heredoc_cnt) {
4103 struct command *cmd = pi->cmds;
4105 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4107 cmd->argv ? cmd->argv[0] : "NONE");
4108 for (i = 0; i < pi->num_cmds; i++) {
4109 struct redir_struct *redir = cmd->redirects;
4111 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4112 i, cmd->argv ? cmd->argv[0] : "NONE");
4114 if (redir->rd_type == REDIRECT_HEREDOC) {
4117 redir->rd_type = REDIRECT_HEREDOC2;
4118 /* redir->rd_dup is (ab)used to indicate <<- */
4119 p = fetch_till_str(&ctx->as_string, input,
4120 redir->rd_filename, redir->rd_dup);
4122 syntax_error("unexpected EOF in here document");
4125 free(redir->rd_filename);
4126 redir->rd_filename = p;
4129 redir = redir->next;
4136 /* Should be 0. If it isn't, it's a parse error */
4138 bb_error_msg_and_die("heredoc BUG 2");
4144 static int run_list(struct pipe *pi);
4146 #define parse_stream(pstring, input, end_trigger) \
4147 parse_stream(input, end_trigger)
4149 static struct pipe *parse_stream(char **pstring,
4150 struct in_str *input,
4154 #if !ENABLE_HUSH_FUNCTIONS
4155 #define parse_group(dest, ctx, input, ch) \
4156 parse_group(ctx, input, ch)
4158 static int parse_group(o_string *dest, struct parse_context *ctx,
4159 struct in_str *input, int ch)
4161 /* dest contains characters seen prior to ( or {.
4162 * Typically it's empty, but for function defs,
4163 * it contains function name (without '()'). */
4164 struct pipe *pipe_list;
4166 struct command *command = ctx->command;
4168 debug_printf_parse("parse_group entered\n");
4169 #if ENABLE_HUSH_FUNCTIONS
4170 if (ch == '(' && !dest->has_quoted_part) {
4172 if (done_word(dest, ctx))
4175 goto skip; /* (... */
4176 if (command->argv[1]) { /* word word ... (... */
4177 syntax_error_unexpected_ch('(');
4180 /* it is "word(..." or "word (..." */
4182 ch = i_getch(input);
4183 while (ch == ' ' || ch == '\t');
4185 syntax_error_unexpected_ch(ch);
4188 nommu_addchr(&ctx->as_string, ch);
4190 ch = i_getch(input);
4191 while (ch == ' ' || ch == '\t' || ch == '\n');
4193 syntax_error_unexpected_ch(ch);
4196 nommu_addchr(&ctx->as_string, ch);
4197 command->cmd_type = CMD_FUNCDEF;
4202 #if 0 /* Prevented by caller */
4203 if (command->argv /* word [word]{... */
4204 || dest->length /* word{... */
4205 || dest->has_quoted_part /* ""{... */
4208 debug_printf_parse("parse_group return 1: "
4209 "syntax error, groups and arglists don't mix\n");
4214 #if ENABLE_HUSH_FUNCTIONS
4220 command->cmd_type = CMD_SUBSHELL;
4222 /* bash does not allow "{echo...", requires whitespace */
4224 if (ch != ' ' && ch != '\t' && ch != '\n'
4225 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4227 syntax_error_unexpected_ch(ch);
4231 ch = i_getch(input);
4232 nommu_addchr(&ctx->as_string, ch);
4238 # define as_string NULL
4240 char *as_string = NULL;
4242 pipe_list = parse_stream(&as_string, input, endch);
4245 o_addstr(&ctx->as_string, as_string);
4247 /* empty ()/{} or parse error? */
4248 if (!pipe_list || pipe_list == ERR_PTR) {
4249 /* parse_stream already emitted error msg */
4252 debug_printf_parse("parse_group return 1: "
4253 "parse_stream returned %p\n", pipe_list);
4256 command->group = pipe_list;
4258 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4259 command->group_as_string = as_string;
4260 debug_printf_parse("end of group, remembering as:'%s'\n",
4261 command->group_as_string);
4265 debug_printf_parse("parse_group return 0\n");
4267 /* command remains "open", available for possible redirects */
4270 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4275 ch = i_getch(input);
4278 ch2 = i_peek(input);
4281 /* backslash+newline, skip it */
4286 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4294 ch2 = i_peek2(input);
4297 /* backslash+newline, skip it */
4303 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4304 /* Subroutines for copying $(...) and `...` things */
4305 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4307 static int add_till_single_quote(o_string *dest, struct in_str *input)
4310 int ch = i_getch(input);
4312 syntax_error_unterm_ch('\'');
4320 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4321 static int add_till_double_quote(o_string *dest, struct in_str *input)
4324 int ch = i_getch(input);
4326 syntax_error_unterm_ch('"');
4331 if (ch == '\\') { /* \x. Copy both chars. */
4333 ch = i_getch(input);
4337 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4342 //if (ch == '$') ...
4345 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4347 * "Within the backquoted style of command substitution, backslash
4348 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4349 * The search for the matching backquote shall be satisfied by the first
4350 * backquote found without a preceding backslash; during this search,
4351 * if a non-escaped backquote is encountered within a shell comment,
4352 * a here-document, an embedded command substitution of the $(command)
4353 * form, or a quoted string, undefined results occur. A single-quoted
4354 * or double-quoted string that begins, but does not end, within the
4355 * "`...`" sequence produces undefined results."
4357 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4359 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4362 int ch = i_getch(input);
4366 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4367 ch = i_getch(input);
4371 && (!in_dquote || ch != '"')
4373 o_addchr(dest, '\\');
4377 syntax_error_unterm_ch('`');
4383 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4384 * quoting and nested ()s.
4385 * "With the $(command) style of command substitution, all characters
4386 * following the open parenthesis to the matching closing parenthesis
4387 * constitute the command. Any valid shell script can be used for command,
4388 * except a script consisting solely of redirections which produces
4389 * unspecified results."
4391 * echo $(echo '(TEST)' BEST) (TEST) BEST
4392 * echo $(echo 'TEST)' BEST) TEST) BEST
4393 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4395 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4396 * can contain arbitrary constructs, just like $(cmd).
4397 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4398 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4400 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4401 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4404 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4405 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4406 char end_char2 = end_ch >> 8;
4408 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4411 ch = i_getch(input);
4413 syntax_error_unterm_ch(end_ch);
4417 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4423 /* we look for closing )) of $((EXPR)) */
4424 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4425 i_getch(input); /* eat second ')' */
4430 if (ch == '(' || ch == '{') {
4431 ch = (ch == '(' ? ')' : '}');
4432 if (!add_till_closing_bracket(dest, input, ch))
4438 if (!add_till_single_quote(dest, input))
4444 if (!add_till_double_quote(dest, input))
4450 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4456 /* \x. Copy verbatim. Important for \(, \) */
4457 ch = i_getch(input);
4459 syntax_error_unterm_ch(')');
4464 /* "backslash+newline", ignore both */
4465 o_delchr(dest); /* undo insertion of '\' */
4475 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4477 /* Return code: 0 for OK, 1 for syntax error */
4479 #define parse_dollar(as_string, dest, input, quote_mask) \
4480 parse_dollar(dest, input, quote_mask)
4481 #define as_string NULL
4483 static int parse_dollar(o_string *as_string,
4485 struct in_str *input, unsigned char quote_mask)
4487 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4489 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4491 ch = i_getch(input);
4492 nommu_addchr(as_string, ch);
4494 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4496 debug_printf_parse(": '%c'\n", ch);
4497 o_addchr(dest, ch | quote_mask);
4499 ch = i_peek_and_eat_bkslash_nl(input);
4500 if (!isalnum(ch) && ch != '_') {
4501 /* End of variable name reached */
4504 ch = i_getch(input);
4505 nommu_addchr(as_string, ch);
4507 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4508 } else if (isdigit(ch)) {
4510 ch = i_getch(input);
4511 nommu_addchr(as_string, ch);
4512 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4513 debug_printf_parse(": '%c'\n", ch);
4514 o_addchr(dest, ch | quote_mask);
4515 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4516 } else switch (ch) {
4518 case '!': /* last bg pid */
4519 case '?': /* last exit code */
4520 case '#': /* number of args */
4521 case '*': /* args */
4522 case '@': /* args */
4523 goto make_one_char_var;
4527 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4529 ch = i_getch(input); /* eat '{' */
4530 nommu_addchr(as_string, ch);
4532 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4533 /* It should be ${?}, or ${#var},
4534 * or even ${?+subst} - operator acting on a special variable,
4535 * or the beginning of variable name.
4538 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4541 syntax_error_unterm_str("${name}");
4542 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4545 nommu_addchr(as_string, ch);
4549 /* It's possible to just call add_till_closing_bracket() at this point.
4550 * However, this regresses some of our testsuite cases
4551 * which check invalid constructs like ${%}.
4552 * Oh well... let's check that the var name part is fine... */
4558 debug_printf_parse(": '%c'\n", ch);
4560 ch = i_getch(input);
4561 nommu_addchr(as_string, ch);
4565 if (!isalnum(ch) && ch != '_') {
4567 unsigned char last_ch;
4568 /* handle parameter expansions
4569 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4571 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4572 if (len_single_ch != '#'
4573 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4574 || i_peek(input) != '}'
4576 goto bad_dollar_syntax;
4578 /* else: it's "length of C" ${#C} op,
4579 * where C is a single char
4580 * special var name, e.g. ${#!}.
4583 /* Eat everything until closing '}' (or ':') */
4587 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4589 /* It's ${var:N[:M]} thing */
4590 end_ch = '}' * 0x100 + ':';
4592 if (BASH_PATTERN_SUBST
4595 /* It's ${var/[/]pattern[/repl]} thing */
4596 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4598 nommu_addchr(as_string, '/');
4601 end_ch = '}' * 0x100 + '/';
4607 #if ENABLE_HUSH_DOLLAR_OPS
4608 last_ch = add_till_closing_bracket(dest, input, end_ch);
4609 if (last_ch == 0) /* error? */
4612 #error Simple code to only allow ${var} is not implemented
4615 o_addstr(as_string, dest->data + pos);
4616 o_addchr(as_string, last_ch);
4619 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4620 && (end_ch & 0xff00)
4622 /* close the first block: */
4623 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4624 /* while parsing N from ${var:N[:M]}
4625 * or pattern from ${var/[/]pattern[/repl]} */
4626 if ((end_ch & 0xff) == last_ch) {
4627 /* got ':' or '/'- parse the rest */
4632 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4633 /* it's ${var:N} - emulate :999999999 */
4634 o_addstr(dest, "999999999");
4635 } /* else: it's ${var/[/]pattern} */
4639 len_single_ch = 0; /* it can't be ${#C} op */
4641 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4644 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4648 ch = i_getch(input);
4649 nommu_addchr(as_string, ch);
4650 # if ENABLE_FEATURE_SH_MATH
4651 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4652 ch = i_getch(input);
4653 nommu_addchr(as_string, ch);
4654 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4655 o_addchr(dest, /*quote_mask |*/ '+');
4658 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4659 return 0; /* error */
4661 o_addstr(as_string, dest->data + pos);
4662 o_addchr(as_string, ')');
4663 o_addchr(as_string, ')');
4665 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4669 # if ENABLE_HUSH_TICK
4670 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4671 o_addchr(dest, quote_mask | '`');
4674 if (!add_till_closing_bracket(dest, input, ')'))
4675 return 0; /* error */
4677 o_addstr(as_string, dest->data + pos);
4678 o_addchr(as_string, ')');
4680 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4686 ch = i_getch(input);
4687 nommu_addchr(as_string, ch);
4688 ch = i_peek_and_eat_bkslash_nl(input);
4689 if (isalnum(ch)) { /* it's $_name or $_123 */
4694 /* TODO: $_ and $-: */
4695 /* $_ Shell or shell script name; or last argument of last command
4696 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4697 * but in command's env, set to full pathname used to invoke it */
4698 /* $- Option flags set by set builtin or shell options (-i etc) */
4700 o_addQchr(dest, '$');
4702 debug_printf_parse("parse_dollar return 1 (ok)\n");
4708 # if BASH_PATTERN_SUBST
4709 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4710 encode_string(dest, input, dquote_end, process_bkslash)
4712 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4713 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4714 encode_string(dest, input, dquote_end)
4716 #define as_string NULL
4720 # if BASH_PATTERN_SUBST
4721 /* all parameters are needed, no macro tricks */
4723 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4724 encode_string(as_string, dest, input, dquote_end)
4727 static int encode_string(o_string *as_string,
4729 struct in_str *input,
4731 int process_bkslash)
4733 #if !BASH_PATTERN_SUBST
4734 const int process_bkslash = 1;
4740 ch = i_getch(input);
4742 nommu_addchr(as_string, ch);
4743 if (ch == dquote_end) { /* may be only '"' or EOF */
4744 debug_printf_parse("encode_string return 1 (ok)\n");
4747 /* note: can't move it above ch == dquote_end check! */
4749 syntax_error_unterm_ch('"');
4750 return 0; /* error */
4754 next = i_peek(input);
4756 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4757 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4758 if (process_bkslash && ch == '\\') {
4760 syntax_error("\\<eof>");
4764 * "The backslash retains its special meaning [in "..."]
4765 * only when followed by one of the following characters:
4766 * $, `, ", \, or <newline>. A double quote may be quoted
4767 * within double quotes by preceding it with a backslash."
4768 * NB: in (unquoted) heredoc, above does not apply to ",
4769 * therefore we check for it by "next == dquote_end" cond.
4771 if (next == dquote_end || strchr("$`\\\n", next)) {
4772 ch = i_getch(input); /* eat next */
4774 goto again; /* skip \<newline> */
4775 } /* else: ch remains == '\\', and we double it below: */
4776 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4777 nommu_addchr(as_string, ch);
4781 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4782 debug_printf_parse("encode_string return 0: "
4783 "parse_dollar returned 0 (error)\n");
4788 #if ENABLE_HUSH_TICK
4790 //unsigned pos = dest->length;
4791 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4792 o_addchr(dest, 0x80 | '`');
4793 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4794 return 0; /* error */
4795 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4796 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4800 o_addQchr(dest, ch);
4806 * Scan input until EOF or end_trigger char.
4807 * Return a list of pipes to execute, or NULL on EOF
4808 * or if end_trigger character is met.
4809 * On syntax error, exit if shell is not interactive,
4810 * reset parsing machinery and start parsing anew,
4811 * or return ERR_PTR.
4813 static struct pipe *parse_stream(char **pstring,
4814 struct in_str *input,
4817 struct parse_context ctx;
4818 o_string dest = NULL_O_STRING;
4821 /* Single-quote triggers a bypass of the main loop until its mate is
4822 * found. When recursing, quote state is passed in via dest->o_expflags.
4824 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4825 end_trigger ? end_trigger : 'X');
4828 /* If very first arg is "" or '', dest.data may end up NULL.
4829 * Preventing this: */
4830 o_addchr(&dest, '\0');
4833 /* We used to separate words on $IFS here. This was wrong.
4834 * $IFS is used only for word splitting when $var is expanded,
4835 * here we should use blank chars as separators, not $IFS
4838 if (MAYBE_ASSIGNMENT != 0)
4839 dest.o_assignment = MAYBE_ASSIGNMENT;
4840 initialize_context(&ctx);
4843 const char *is_blank;
4844 const char *is_special;
4848 redir_type redir_style;
4850 ch = i_getch(input);
4851 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4852 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4857 syntax_error_unterm_str("here document");
4860 if (end_trigger == ')') {
4861 syntax_error_unterm_ch('(');
4864 if (end_trigger == '}') {
4865 syntax_error_unterm_ch('{');
4869 if (done_word(&dest, &ctx)) {
4873 done_pipe(&ctx, PIPE_SEQ);
4875 /* If we got nothing... */
4876 /* (this makes bare "&" cmd a no-op.
4877 * bash says: "syntax error near unexpected token '&'") */
4878 if (pi->num_cmds == 0
4879 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4885 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4887 *pstring = ctx.as_string.data;
4889 o_free_unsafe(&ctx.as_string);
4892 debug_printf_parse("parse_stream return %p\n", pi);
4895 nommu_addchr(&ctx.as_string, ch);
4899 next = i_peek(input);
4901 is_special = "{}<>;&|()#'" /* special outside of "str" */
4902 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4903 /* Are { and } special here? */
4904 if (ctx.command->argv /* word [word]{... - non-special */
4905 || dest.length /* word{... - non-special */
4906 || dest.has_quoted_part /* ""{... - non-special */
4907 || (next != ';' /* }; - special */
4908 && next != ')' /* }) - special */
4909 && next != '(' /* {( - special */
4910 && next != '&' /* }& and }&& ... - special */
4911 && next != '|' /* }|| ... - special */
4912 && !strchr(defifs, next) /* {word - non-special */
4915 /* They are not special, skip "{}" */
4918 is_special = strchr(is_special, ch);
4919 is_blank = strchr(defifs, ch);
4921 if (!is_special && !is_blank) { /* ordinary char */
4923 o_addQchr(&dest, ch);
4924 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4925 || dest.o_assignment == WORD_IS_KEYWORD)
4927 && is_well_formed_var_name(dest.data, '=')
4929 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4930 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4936 if (done_word(&dest, &ctx)) {
4940 /* Is this a case when newline is simply ignored?
4942 * "cmd | <newline> cmd ..."
4943 * "case ... in <newline> word) ..."
4945 if (IS_NULL_CMD(ctx.command)
4946 && dest.length == 0 && !dest.has_quoted_part
4948 /* This newline can be ignored. But...
4949 * Without check #1, interactive shell
4950 * ignores even bare <newline>,
4951 * and shows the continuation prompt:
4952 * ps1_prompt$ <enter>
4953 * ps2> _ <=== wrong, should be ps1
4954 * Without check #2, "cmd & <newline>"
4955 * is similarly mistreated.
4956 * (BTW, this makes "cmd & cmd"
4957 * and "cmd && cmd" non-orthogonal.
4958 * Really, ask yourself, why
4959 * "cmd && <newline>" doesn't start
4960 * cmd but waits for more input?
4961 * The only reason is that it might be
4962 * a "cmd1 && <nl> cmd2 &" construct,
4963 * cmd1 may need to run in BG).
4965 struct pipe *pi = ctx.list_head;
4966 if (pi->num_cmds != 0 /* check #1 */
4967 && pi->followup != PIPE_BG /* check #2 */
4972 /* Treat newline as a command separator. */
4973 done_pipe(&ctx, PIPE_SEQ);
4974 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4976 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4981 dest.o_assignment = MAYBE_ASSIGNMENT;
4982 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4984 /* note: if (is_blank) continue;
4985 * will still trigger for us */
4989 /* "cmd}" or "cmd }..." without semicolon or &:
4990 * } is an ordinary char in this case, even inside { cmd; }
4991 * Pathological example: { ""}; } should exec "}" cmd
4994 if (dest.length != 0 /* word} */
4995 || dest.has_quoted_part /* ""} */
4999 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
5000 /* Generally, there should be semicolon: "cmd; }"
5001 * However, bash allows to omit it if "cmd" is
5002 * a group. Examples:
5005 * { echo 0 >&2 | { echo 1; } }
5006 * { while false; do :; done }
5007 * { case a in b) ;; esac }
5009 if (ctx.command->group)
5013 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5014 /* Can't be an end of {cmd}, skip the check */
5015 goto skip_end_trigger;
5016 /* else: } does terminate a group */
5019 if (end_trigger && end_trigger == ch
5020 && (ch != ';' || heredoc_cnt == 0)
5021 #if ENABLE_HUSH_CASE
5023 || ctx.ctx_res_w != RES_MATCH
5024 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5029 /* This is technically valid:
5030 * { cat <<HERE; }; echo Ok
5034 * but we don't support this.
5035 * We require heredoc to be in enclosing {}/(),
5038 syntax_error_unterm_str("here document");
5041 if (done_word(&dest, &ctx)) {
5044 done_pipe(&ctx, PIPE_SEQ);
5045 dest.o_assignment = MAYBE_ASSIGNMENT;
5046 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5047 /* Do we sit outside of any if's, loops or case's? */
5049 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5053 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5055 *pstring = ctx.as_string.data;
5057 o_free_unsafe(&ctx.as_string);
5059 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5060 /* Example: bare "{ }", "()" */
5061 G.last_exitcode = 2; /* bash compat */
5062 syntax_error_unexpected_ch(ch);
5065 debug_printf_parse("parse_stream return %p: "
5066 "end_trigger char found\n",
5069 return ctx.list_head;
5076 /* Catch <, > before deciding whether this word is
5077 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5080 redir_fd = redirect_opt_num(&dest);
5081 if (done_word(&dest, &ctx)) {
5084 redir_style = REDIRECT_OVERWRITE;
5086 redir_style = REDIRECT_APPEND;
5087 ch = i_getch(input);
5088 nommu_addchr(&ctx.as_string, ch);
5091 else if (next == '(') {
5092 syntax_error(">(process) not supported");
5096 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5098 continue; /* back to top of while (1) */
5100 redir_fd = redirect_opt_num(&dest);
5101 if (done_word(&dest, &ctx)) {
5104 redir_style = REDIRECT_INPUT;
5106 redir_style = REDIRECT_HEREDOC;
5108 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5109 ch = i_getch(input);
5110 nommu_addchr(&ctx.as_string, ch);
5111 } else if (next == '>') {
5112 redir_style = REDIRECT_IO;
5113 ch = i_getch(input);
5114 nommu_addchr(&ctx.as_string, ch);
5117 else if (next == '(') {
5118 syntax_error("<(process) not supported");
5122 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5124 continue; /* back to top of while (1) */
5126 if (dest.length == 0 && !dest.has_quoted_part) {
5127 /* skip "#comment" */
5128 /* note: we do not add it to &ctx.as_string */
5130 * comment inside $() goes to the next \n, even inside quoted string (!):
5131 * cmd "$(cmd2 #comment)" - syntax error
5132 * cmd "`cmd2 #comment`" - ok
5133 * We accept both (comment ends where command subst ends, in both cases).
5138 nommu_addchr(&ctx.as_string, '\n');
5141 ch = i_getch(input);
5145 continue; /* back to top of while (1) */
5150 /* It's "\<newline>" */
5152 /* Remove trailing '\' from ctx.as_string */
5153 ctx.as_string.data[--ctx.as_string.length] = '\0';
5155 ch = i_getch(input); /* eat it */
5156 continue; /* back to top of while (1) */
5161 if (dest.o_assignment == MAYBE_ASSIGNMENT
5162 /* check that we are not in word in "a=1 2>word b=1": */
5163 && !ctx.pending_redirect
5165 /* ch is a special char and thus this word
5166 * cannot be an assignment */
5167 dest.o_assignment = NOT_ASSIGNMENT;
5168 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5171 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5174 case '#': /* non-comment #: "echo a#b" etc */
5175 o_addQchr(&dest, ch);
5179 syntax_error("\\<eof>");
5182 ch = i_getch(input);
5183 /* note: ch != '\n' (that case does not reach this place) */
5184 o_addchr(&dest, '\\');
5185 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5186 o_addchr(&dest, ch);
5187 nommu_addchr(&ctx.as_string, ch);
5188 /* Example: echo Hello \2>file
5189 * we need to know that word 2 is quoted */
5190 dest.has_quoted_part = 1;
5193 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5194 debug_printf_parse("parse_stream parse error: "
5195 "parse_dollar returned 0 (error)\n");
5200 dest.has_quoted_part = 1;
5201 if (next == '\'' && !ctx.pending_redirect) {
5202 insert_empty_quoted_str_marker:
5203 nommu_addchr(&ctx.as_string, next);
5204 i_getch(input); /* eat second ' */
5205 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5206 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5209 ch = i_getch(input);
5211 syntax_error_unterm_ch('\'');
5214 nommu_addchr(&ctx.as_string, ch);
5217 o_addqchr(&dest, ch);
5222 dest.has_quoted_part = 1;
5223 if (next == '"' && !ctx.pending_redirect)
5224 goto insert_empty_quoted_str_marker;
5225 if (dest.o_assignment == NOT_ASSIGNMENT)
5226 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5227 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5229 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5231 #if ENABLE_HUSH_TICK
5233 USE_FOR_NOMMU(unsigned pos;)
5235 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5236 o_addchr(&dest, '`');
5237 USE_FOR_NOMMU(pos = dest.length;)
5238 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5241 o_addstr(&ctx.as_string, dest.data + pos);
5242 o_addchr(&ctx.as_string, '`');
5244 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5245 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5250 #if ENABLE_HUSH_CASE
5253 if (done_word(&dest, &ctx)) {
5256 done_pipe(&ctx, PIPE_SEQ);
5257 #if ENABLE_HUSH_CASE
5258 /* Eat multiple semicolons, detect
5259 * whether it means something special */
5264 ch = i_getch(input);
5265 nommu_addchr(&ctx.as_string, ch);
5266 if (ctx.ctx_res_w == RES_CASE_BODY) {
5267 ctx.ctx_dsemicolon = 1;
5268 ctx.ctx_res_w = RES_MATCH;
5274 /* We just finished a cmd. New one may start
5275 * with an assignment */
5276 dest.o_assignment = MAYBE_ASSIGNMENT;
5277 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5280 if (done_word(&dest, &ctx)) {
5284 ch = i_getch(input);
5285 nommu_addchr(&ctx.as_string, ch);
5286 done_pipe(&ctx, PIPE_AND);
5288 done_pipe(&ctx, PIPE_BG);
5292 if (done_word(&dest, &ctx)) {
5295 #if ENABLE_HUSH_CASE
5296 if (ctx.ctx_res_w == RES_MATCH)
5297 break; /* we are in case's "word | word)" */
5299 if (next == '|') { /* || */
5300 ch = i_getch(input);
5301 nommu_addchr(&ctx.as_string, ch);
5302 done_pipe(&ctx, PIPE_OR);
5304 /* we could pick up a file descriptor choice here
5305 * with redirect_opt_num(), but bash doesn't do it.
5306 * "echo foo 2| cat" yields "foo 2". */
5311 #if ENABLE_HUSH_CASE
5312 /* "case... in [(]word)..." - skip '(' */
5313 if (ctx.ctx_res_w == RES_MATCH
5314 && ctx.command->argv == NULL /* not (word|(... */
5315 && dest.length == 0 /* not word(... */
5316 && dest.has_quoted_part == 0 /* not ""(... */
5322 if (parse_group(&dest, &ctx, input, ch) != 0) {
5327 #if ENABLE_HUSH_CASE
5328 if (ctx.ctx_res_w == RES_MATCH)
5332 /* proper use of this character is caught by end_trigger:
5333 * if we see {, we call parse_group(..., end_trigger='}')
5334 * and it will match } earlier (not here). */
5335 G.last_exitcode = 2;
5336 syntax_error_unexpected_ch(ch);
5340 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5345 G.last_exitcode = 1;
5348 struct parse_context *pctx;
5349 IF_HAS_KEYWORDS(struct parse_context *p2;)
5351 /* Clean up allocated tree.
5352 * Sample for finding leaks on syntax error recovery path.
5353 * Run it from interactive shell, watch pmap `pidof hush`.
5354 * while if false; then false; fi; do break; fi
5355 * Samples to catch leaks at execution:
5356 * while if (true | { true;}); then echo ok; fi; do break; done
5357 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5361 /* Update pipe/command counts,
5362 * otherwise freeing may miss some */
5363 done_pipe(pctx, PIPE_SEQ);
5364 debug_printf_clean("freeing list %p from ctx %p\n",
5365 pctx->list_head, pctx);
5366 debug_print_tree(pctx->list_head, 0);
5367 free_pipe_list(pctx->list_head);
5368 debug_printf_clean("freed list %p\n", pctx->list_head);
5370 o_free_unsafe(&pctx->as_string);
5372 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5376 IF_HAS_KEYWORDS(pctx = p2;)
5377 } while (HAS_KEYWORDS && pctx);
5390 /*** Execution routines ***/
5392 /* Expansion can recurse, need forward decls: */
5393 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5394 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5395 #define expand_string_to_string(str, do_unbackslash) \
5396 expand_string_to_string(str)
5398 static char *expand_string_to_string(const char *str, int do_unbackslash);
5399 #if ENABLE_HUSH_TICK
5400 static int process_command_subs(o_string *dest, const char *s);
5403 /* expand_strvec_to_strvec() takes a list of strings, expands
5404 * all variable references within and returns a pointer to
5405 * a list of expanded strings, possibly with larger number
5406 * of strings. (Think VAR="a b"; echo $VAR).
5407 * This new list is allocated as a single malloc block.
5408 * NULL-terminated list of char* pointers is at the beginning of it,
5409 * followed by strings themselves.
5410 * Caller can deallocate entire list by single free(list). */
5412 /* A horde of its helpers come first: */
5414 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5416 while (--len >= 0) {
5419 #if ENABLE_HUSH_BRACE_EXPANSION
5420 if (c == '{' || c == '}') {
5421 /* { -> \{, } -> \} */
5423 /* And now we want to add { or } and continue:
5426 * luckily, just falling through achieves this.
5432 /* \z -> \\\z; \<eol> -> \\<eol> */
5437 o_addchr(o, *str++);
5443 /* Store given string, finalizing the word and starting new one whenever
5444 * we encounter IFS char(s). This is used for expanding variable values.
5445 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5446 * Return in *ended_with_ifs:
5447 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5449 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5451 int last_is_ifs = 0;
5456 if (!*str) /* EOL - do not finalize word */
5458 word_len = strcspn(str, G.ifs);
5460 /* We have WORD_LEN leading non-IFS chars */
5461 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5462 o_addblock(output, str, word_len);
5464 /* Protect backslashes against globbing up :)
5465 * Example: "v='\*'; echo b$v" prints "b\*"
5466 * (and does not try to glob on "*")
5468 o_addblock_duplicate_backslash(output, str, word_len);
5469 /*/ Why can't we do it easier? */
5470 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5471 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5475 if (!*str) /* EOL - do not finalize word */
5479 /* We know str here points to at least one IFS char */
5481 str += strspn(str, G.ifs); /* skip IFS chars */
5482 if (!*str) /* EOL - do not finalize word */
5485 /* Start new word... but not always! */
5486 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5487 if (output->has_quoted_part
5488 /* Case "v=' a'; echo $v":
5489 * here nothing precedes the space in $v expansion,
5490 * therefore we should not finish the word
5491 * (IOW: if there *is* word to finalize, only then do it):
5493 || (n > 0 && output->data[output->length - 1])
5495 o_addchr(output, '\0');
5496 debug_print_list("expand_on_ifs", output, n);
5497 n = o_save_ptr(output, n);
5502 *ended_with_ifs = last_is_ifs;
5503 debug_print_list("expand_on_ifs[1]", output, n);
5507 /* Helper to expand $((...)) and heredoc body. These act as if
5508 * they are in double quotes, with the exception that they are not :).
5509 * Just the rules are similar: "expand only $var and `cmd`"
5511 * Returns malloced string.
5512 * As an optimization, we return NULL if expansion is not needed.
5514 #if !BASH_PATTERN_SUBST
5515 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5516 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5517 encode_then_expand_string(str)
5519 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5521 #if !BASH_PATTERN_SUBST
5522 enum { do_unbackslash = 1 };
5525 struct in_str input;
5526 o_string dest = NULL_O_STRING;
5528 if (!strchr(str, '$')
5529 && !strchr(str, '\\')
5530 #if ENABLE_HUSH_TICK
5531 && !strchr(str, '`')
5537 /* We need to expand. Example:
5538 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5540 setup_string_in_str(&input, str);
5541 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5542 //TODO: error check (encode_string returns 0 on error)?
5543 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5544 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5545 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5546 o_free_unsafe(&dest);
5550 #if ENABLE_FEATURE_SH_MATH
5551 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5553 arith_state_t math_state;
5557 math_state.lookupvar = get_local_var_value;
5558 math_state.setvar = set_local_var_from_halves;
5559 //math_state.endofname = endofname;
5560 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5561 res = arith(&math_state, exp_str ? exp_str : arg);
5564 *errmsg_p = math_state.errmsg;
5565 if (math_state.errmsg)
5566 msg_and_die_if_script(math_state.errmsg);
5571 #if BASH_PATTERN_SUBST
5572 /* ${var/[/]pattern[/repl]} helpers */
5573 static char *strstr_pattern(char *val, const char *pattern, int *size)
5576 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5577 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5584 /* Optimization: if "*pat" did not match the start of "string",
5585 * we know that "tring", "ring" etc will not match too:
5587 if (pattern[0] == '*')
5592 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5594 char *result = NULL;
5595 unsigned res_len = 0;
5596 unsigned repl_len = strlen(repl);
5600 char *s = strstr_pattern(val, pattern, &size);
5604 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5605 strcpy(mempcpy(result + res_len, val, s - val), repl);
5606 res_len += (s - val) + repl_len;
5607 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5613 if (*val && result) {
5614 result = xrealloc(result, res_len + strlen(val) + 1);
5615 strcpy(result + res_len, val);
5616 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5618 debug_printf_varexp("result:'%s'\n", result);
5621 #endif /* BASH_PATTERN_SUBST */
5624 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5626 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5628 const char *val = NULL;
5629 char *to_be_freed = NULL;
5634 char exp_save = exp_save; /* for compiler */
5635 char *exp_saveptr; /* points to expansion operator */
5636 char *exp_word = exp_word; /* for compiler */
5639 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5641 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5643 first_char = arg[0] = arg0 & 0x7f;
5646 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5647 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5648 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5649 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5651 /* It must be length operator: ${#var} */
5655 /* Maybe handle parameter expansion */
5656 if (exp_saveptr /* if 2nd char is one of expansion operators */
5657 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5659 /* ${?:0}, ${#[:]%0} etc */
5660 exp_saveptr = var + 1;
5662 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5663 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5665 exp_op = exp_save = *exp_saveptr;
5667 exp_word = exp_saveptr + 1;
5668 if (exp_op == ':') {
5669 exp_op = *exp_word++;
5670 //TODO: try ${var:} and ${var:bogus} in non-bash config
5672 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5674 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5679 *exp_saveptr = '\0';
5680 } /* else: it's not an expansion op, but bare ${var} */
5683 /* Look up the variable in question */
5684 if (isdigit(var[0])) {
5685 /* parse_dollar should have vetted var for us */
5686 int n = xatoi_positive(var);
5687 if (n < G.global_argc)
5688 val = G.global_argv[n];
5689 /* else val remains NULL: $N with too big N */
5693 val = utoa(G.root_pid);
5695 case '!': /* bg pid */
5696 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5698 case '?': /* exitcode */
5699 val = utoa(G.last_exitcode);
5701 case '#': /* argc */
5702 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5705 val = get_local_var_value(var);
5709 /* Handle any expansions */
5710 if (exp_op == 'L') {
5711 reinit_unicode_for_hush();
5712 debug_printf_expand("expand: length(%s)=", val);
5713 val = utoa(val ? unicode_strlen(val) : 0);
5714 debug_printf_expand("%s\n", val);
5715 } else if (exp_op) {
5716 if (exp_op == '%' || exp_op == '#') {
5717 /* Standard-mandated substring removal ops:
5718 * ${parameter%word} - remove smallest suffix pattern
5719 * ${parameter%%word} - remove largest suffix pattern
5720 * ${parameter#word} - remove smallest prefix pattern
5721 * ${parameter##word} - remove largest prefix pattern
5723 * Word is expanded to produce a glob pattern.
5724 * Then var's value is matched to it and matching part removed.
5726 if (val && val[0]) {
5730 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5731 if (exp_op == *exp_word) /* ## or %% */
5733 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5735 exp_word = exp_exp_word;
5736 /* HACK ALERT. We depend here on the fact that
5737 * G.global_argv and results of utoa and get_local_var_value
5738 * are actually in writable memory:
5739 * scan_and_match momentarily stores NULs there. */
5741 loc = scan_and_match(t, exp_word, scan_flags);
5742 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5743 // exp_op, t, exp_word, loc);
5745 if (loc) { /* match was found */
5746 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5747 val = loc; /* take right part */
5749 val = to_be_freed = xstrndup(val, loc - val); /* left */
5753 #if BASH_PATTERN_SUBST
5754 else if (exp_op == '/' || exp_op == '\\') {
5755 /* It's ${var/[/]pattern[/repl]} thing.
5756 * Note that in encoded form it has TWO parts:
5757 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5758 * and if // is used, it is encoded as \:
5759 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5761 /* Empty variable always gives nothing: */
5762 // "v=''; echo ${v/*/w}" prints "", not "w"
5763 if (val && val[0]) {
5764 /* pattern uses non-standard expansion.
5765 * repl should be unbackslashed and globbed
5766 * by the usual expansion rules:
5768 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5769 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5770 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5771 * v='a bz'; echo ${v/a*z/\z} prints "z"
5772 * (note that a*z _pattern_ is never globbed!)
5774 char *pattern, *repl, *t;
5775 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5777 pattern = xstrdup(exp_word);
5778 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5779 *p++ = SPECIAL_VAR_SYMBOL;
5781 p = strchr(p, SPECIAL_VAR_SYMBOL);
5783 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5784 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5785 /* HACK ALERT. We depend here on the fact that
5786 * G.global_argv and results of utoa and get_local_var_value
5787 * are actually in writable memory:
5788 * replace_pattern momentarily stores NULs there. */
5790 to_be_freed = replace_pattern(t,
5792 (repl ? repl : exp_word),
5794 if (to_be_freed) /* at least one replace happened */
5800 #endif /* BASH_PATTERN_SUBST */
5801 else if (exp_op == ':') {
5802 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5803 /* It's ${var:N[:M]} bashism.
5804 * Note that in encoded form it has TWO parts:
5805 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5810 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5813 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5814 *p++ = SPECIAL_VAR_SYMBOL;
5816 p = strchr(p, SPECIAL_VAR_SYMBOL);
5818 len = expand_and_evaluate_arith(exp_word, &errmsg);
5821 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5823 /* negative beg counts from the end */
5824 beg = (arith_t)strlen(val) + beg;
5825 if (beg < 0) /* ${v: -999999} is "" */
5828 debug_printf_varexp("from val:'%s'\n", val);
5830 /* in bash, len=-n means strlen()-n */
5831 len = (arith_t)strlen(val) - beg + len;
5832 if (len < 0) /* bash compat */
5833 msg_and_die_if_script("%s: substring expression < 0", var);
5835 if (len <= 0 || !val || beg >= strlen(val)) {
5839 /* Paranoia. What if user entered 9999999999999
5840 * which fits in arith_t but not int? */
5843 val = to_be_freed = xstrndup(val + beg, len);
5845 debug_printf_varexp("val:'%s'\n", val);
5846 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5847 msg_and_die_if_script("malformed ${%s:...}", var);
5850 } else { /* one of "-=+?" */
5851 /* Standard-mandated substitution ops:
5852 * ${var?word} - indicate error if unset
5853 * If var is unset, word (or a message indicating it is unset
5854 * if word is null) is written to standard error
5855 * and the shell exits with a non-zero exit status.
5856 * Otherwise, the value of var is substituted.
5857 * ${var-word} - use default value
5858 * If var is unset, word is substituted.
5859 * ${var=word} - assign and use default value
5860 * If var is unset, word is assigned to var.
5861 * In all cases, final value of var is substituted.
5862 * ${var+word} - use alternative value
5863 * If var is unset, null is substituted.
5864 * Otherwise, word is substituted.
5866 * Word is subjected to tilde expansion, parameter expansion,
5867 * command substitution, and arithmetic expansion.
5868 * If word is not needed, it is not expanded.
5870 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5871 * but also treat null var as if it is unset.
5873 int use_word = (!val || ((exp_save == ':') && !val[0]));
5875 use_word = !use_word;
5876 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5877 (exp_save == ':') ? "true" : "false", use_word);
5879 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5881 exp_word = to_be_freed;
5882 if (exp_op == '?') {
5883 /* mimic bash message */
5884 msg_and_die_if_script("%s: %s",
5888 : "parameter null or not set"
5889 /* ash has more specific messages, a-la: */
5890 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5892 //TODO: how interactive bash aborts expansion mid-command?
5897 if (exp_op == '=') {
5898 /* ${var=[word]} or ${var:=[word]} */
5899 if (isdigit(var[0]) || var[0] == '#') {
5900 /* mimic bash message */
5901 msg_and_die_if_script("$%s: cannot assign in this way", var);
5904 char *new_var = xasprintf("%s=%s", var, val);
5905 set_local_var(new_var, /*flag:*/ 0);
5909 } /* one of "-=+?" */
5911 *exp_saveptr = exp_save;
5917 *to_be_freed_pp = to_be_freed;
5921 /* Expand all variable references in given string, adding words to list[]
5922 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5923 * to be filled). This routine is extremely tricky: has to deal with
5924 * variables/parameters with whitespace, $* and $@, and constructs like
5925 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5926 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5928 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5929 * expansion of right-hand side of assignment == 1-element expand.
5931 char cant_be_null = 0; /* only bit 0x80 matters */
5932 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5935 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5936 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5937 debug_print_list("expand_vars_to_list", output, n);
5938 n = o_save_ptr(output, n);
5939 debug_print_list("expand_vars_to_list[0]", output, n);
5941 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5943 char *to_be_freed = NULL;
5944 const char *val = NULL;
5945 #if ENABLE_HUSH_TICK
5946 o_string subst_result = NULL_O_STRING;
5948 #if ENABLE_FEATURE_SH_MATH
5949 char arith_buf[sizeof(arith_t)*3 + 2];
5953 o_addchr(output, '\0');
5954 n = o_save_ptr(output, n);
5958 o_addblock(output, arg, p - arg);
5959 debug_print_list("expand_vars_to_list[1]", output, n);
5961 p = strchr(p, SPECIAL_VAR_SYMBOL);
5963 /* Fetch special var name (if it is indeed one of them)
5964 * and quote bit, force the bit on if singleword expansion -
5965 * important for not getting v=$@ expand to many words. */
5966 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5968 /* Is this variable quoted and thus expansion can't be null?
5969 * "$@" is special. Even if quoted, it can still
5970 * expand to nothing (not even an empty string),
5971 * thus it is excluded. */
5972 if ((first_ch & 0x7f) != '@')
5973 cant_be_null |= first_ch;
5975 switch (first_ch & 0x7f) {
5976 /* Highest bit in first_ch indicates that var is double-quoted */
5980 if (!G.global_argv[1])
5983 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5984 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5985 while (G.global_argv[i]) {
5986 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5987 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5988 if (G.global_argv[i++][0] && G.global_argv[i]) {
5989 /* this argv[] is not empty and not last:
5990 * put terminating NUL, start new word */
5991 o_addchr(output, '\0');
5992 debug_print_list("expand_vars_to_list[2]", output, n);
5993 n = o_save_ptr(output, n);
5994 debug_print_list("expand_vars_to_list[3]", output, n);
5998 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5999 * and in this case should treat it like '$*' - see 'else...' below */
6000 if (first_ch == ('@'|0x80) /* quoted $@ */
6001 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
6004 o_addQstr(output, G.global_argv[i]);
6005 if (++i >= G.global_argc)
6007 o_addchr(output, '\0');
6008 debug_print_list("expand_vars_to_list[4]", output, n);
6009 n = o_save_ptr(output, n);
6011 } else { /* quoted $* (or v="$@" case): add as one word */
6013 o_addQstr(output, G.global_argv[i]);
6014 if (!G.global_argv[++i])
6017 o_addchr(output, G.ifs[0]);
6019 output->has_quoted_part = 1;
6023 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
6024 /* "Empty variable", used to make "" etc to not disappear */
6025 output->has_quoted_part = 1;
6027 cant_be_null = 0x80;
6029 #if ENABLE_HUSH_TICK
6030 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6031 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6033 /* Can't just stuff it into output o_string,
6034 * expanded result may need to be globbed
6036 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6037 G.last_exitcode = process_command_subs(&subst_result, arg);
6038 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6039 val = subst_result.data;
6042 #if ENABLE_FEATURE_SH_MATH
6043 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6046 arg++; /* skip '+' */
6047 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6048 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6049 res = expand_and_evaluate_arith(arg, NULL);
6050 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6051 sprintf(arith_buf, ARITH_FMT, res);
6057 val = expand_one_var(&to_be_freed, arg, &p);
6058 IF_HUSH_TICK(store_val:)
6059 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6060 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6061 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6062 if (val && val[0]) {
6063 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6066 } else { /* quoted $VAR, val will be appended below */
6067 output->has_quoted_part = 1;
6068 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6069 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6072 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6074 if (val && val[0]) {
6075 o_addQstr(output, val);
6079 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6080 * Do the check to avoid writing to a const string. */
6081 if (*p != SPECIAL_VAR_SYMBOL)
6082 *p = SPECIAL_VAR_SYMBOL;
6084 #if ENABLE_HUSH_TICK
6085 o_free(&subst_result);
6088 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6092 o_addchr(output, '\0');
6093 n = o_save_ptr(output, n);
6095 debug_print_list("expand_vars_to_list[a]", output, n);
6096 /* this part is literal, and it was already pre-quoted
6097 * if needed (much earlier), do not use o_addQstr here! */
6098 o_addstr_with_NUL(output, arg);
6099 debug_print_list("expand_vars_to_list[b]", output, n);
6100 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6101 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6104 /* allow to reuse list[n] later without re-growth */
6105 output->has_empty_slot = 1;
6107 o_addchr(output, '\0');
6113 static char **expand_variables(char **argv, unsigned expflags)
6117 o_string output = NULL_O_STRING;
6119 output.o_expflags = expflags;
6123 n = expand_vars_to_list(&output, n, *argv);
6126 debug_print_list("expand_variables", &output, n);
6128 /* output.data (malloced in one block) gets returned in "list" */
6129 list = o_finalize_list(&output, n);
6130 debug_print_strings("expand_variables[1]", list);
6134 static char **expand_strvec_to_strvec(char **argv)
6136 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6140 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6142 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6146 /* Used for expansion of right hand of assignments,
6147 * $((...)), heredocs, variable espansion parts.
6149 * NB: should NOT do globbing!
6150 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6152 static char *expand_string_to_string(const char *str, int do_unbackslash)
6154 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6155 const int do_unbackslash = 1;
6157 char *argv[2], **list;
6159 debug_printf_expand("string_to_string<='%s'\n", str);
6160 /* This is generally an optimization, but it also
6161 * handles "", which otherwise trips over !list[0] check below.
6162 * (is this ever happens that we actually get str="" here?)
6164 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6165 //TODO: Can use on strings with \ too, just unbackslash() them?
6166 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6167 return xstrdup(str);
6170 argv[0] = (char*)str;
6172 list = expand_variables(argv, do_unbackslash
6173 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6174 : EXP_FLAG_SINGLEWORD
6177 if (!list[0] || list[1])
6178 bb_error_msg_and_die("BUG in varexp2");
6179 /* actually, just move string 2*sizeof(char*) bytes back */
6180 overlapping_strcpy((char*)list, list[0]);
6182 unbackslash((char*)list);
6183 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6187 /* Used for "eval" builtin and case string */
6188 static char* expand_strvec_to_string(char **argv)
6192 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6193 /* Convert all NULs to spaces */
6198 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6199 bb_error_msg_and_die("BUG in varexp3");
6200 /* bash uses ' ' regardless of $IFS contents */
6205 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6206 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6210 static char **expand_assignments(char **argv, int count)
6215 G.expanded_assignments = p = NULL;
6216 /* Expand assignments into one string each */
6217 for (i = 0; i < count; i++) {
6218 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6220 G.expanded_assignments = NULL;
6225 static void switch_off_special_sigs(unsigned mask)
6228 while ((mask >>= 1) != 0) {
6232 #if ENABLE_HUSH_TRAP
6234 if (G_traps[sig] && !G_traps[sig][0])
6235 /* trap is '', has to remain SIG_IGN */
6238 G_traps[sig] = NULL;
6241 /* We are here only if no trap or trap was not '' */
6242 install_sighandler(sig, SIG_DFL);
6248 void re_execute_shell(char ***to_free, const char *s,
6249 char *g_argv0, char **g_argv,
6250 char **builtin_argv) NORETURN;
6252 static void reset_traps_to_defaults(void)
6254 /* This function is always called in a child shell
6255 * after fork (not vfork, NOMMU doesn't use this function).
6257 IF_HUSH_TRAP(unsigned sig;)
6260 /* Child shells are not interactive.
6261 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6262 * Testcase: (while :; do :; done) + ^Z should background.
6263 * Same goes for SIGTERM, SIGHUP, SIGINT.
6265 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6266 if (!G_traps && !mask)
6267 return; /* already no traps and no special sigs */
6269 /* Switch off special sigs */
6270 switch_off_special_sigs(mask);
6271 # if ENABLE_HUSH_JOB
6272 G_fatal_sig_mask = 0;
6274 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6275 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6276 * remain set in G.special_sig_mask */
6278 # if ENABLE_HUSH_TRAP
6282 /* Reset all sigs to default except ones with empty traps */
6283 for (sig = 0; sig < NSIG; sig++) {
6285 continue; /* no trap: nothing to do */
6286 if (!G_traps[sig][0])
6287 continue; /* empty trap: has to remain SIG_IGN */
6288 /* sig has non-empty trap, reset it: */
6290 G_traps[sig] = NULL;
6291 /* There is no signal for trap 0 (EXIT) */
6294 install_sighandler(sig, pick_sighandler(sig));
6301 static void re_execute_shell(char ***to_free, const char *s,
6302 char *g_argv0, char **g_argv,
6303 char **builtin_argv) NORETURN;
6304 static void re_execute_shell(char ***to_free, const char *s,
6305 char *g_argv0, char **g_argv,
6306 char **builtin_argv)
6308 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6309 /* delims + 2 * (number of bytes in printed hex numbers) */
6310 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6311 char *heredoc_argv[4];
6312 struct variable *cur;
6313 # if ENABLE_HUSH_FUNCTIONS
6314 struct function *funcp;
6318 unsigned long long empty_trap_mask;
6320 if (!g_argv0) { /* heredoc */
6321 argv = heredoc_argv;
6322 argv[0] = (char *) G.argv0_for_re_execing;
6323 argv[1] = (char *) "-<";
6324 argv[2] = (char *) s;
6326 pp = &argv[3]; /* used as pointer to empty environment */
6332 if (pp) while (*pp++)
6335 empty_trap_mask = 0;
6338 for (sig = 1; sig < NSIG; sig++) {
6339 if (G_traps[sig] && !G_traps[sig][0])
6340 empty_trap_mask |= 1LL << sig;
6344 sprintf(param_buf, NOMMU_HACK_FMT
6345 , (unsigned) G.root_pid
6346 , (unsigned) G.root_ppid
6347 , (unsigned) G.last_bg_pid
6348 , (unsigned) G.last_exitcode
6351 IF_HUSH_LOOPS(, G.depth_of_loop)
6353 # undef NOMMU_HACK_FMT
6354 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6355 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6358 for (cur = G.top_var; cur; cur = cur->next) {
6359 if (!cur->flg_export || cur->flg_read_only)
6362 # if ENABLE_HUSH_FUNCTIONS
6363 for (funcp = G.top_func; funcp; funcp = funcp->next)
6369 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6370 *pp++ = (char *) G.argv0_for_re_execing;
6372 for (cur = G.top_var; cur; cur = cur->next) {
6373 if (strcmp(cur->varstr, hush_version_str) == 0)
6375 if (cur->flg_read_only) {
6376 *pp++ = (char *) "-R";
6377 *pp++ = cur->varstr;
6378 } else if (!cur->flg_export) {
6379 *pp++ = (char *) "-V";
6380 *pp++ = cur->varstr;
6383 # if ENABLE_HUSH_FUNCTIONS
6384 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6385 *pp++ = (char *) "-F";
6386 *pp++ = funcp->name;
6387 *pp++ = funcp->body_as_string;
6390 /* We can pass activated traps here. Say, -Tnn:trap_string
6392 * However, POSIX says that subshells reset signals with traps
6394 * I tested bash-3.2 and it not only does that with true subshells
6395 * of the form ( list ), but with any forked children shells.
6396 * I set trap "echo W" WINCH; and then tried:
6398 * { echo 1; sleep 20; echo 2; } &
6399 * while true; do echo 1; sleep 20; echo 2; break; done &
6400 * true | { echo 1; sleep 20; echo 2; } | cat
6402 * In all these cases sending SIGWINCH to the child shell
6403 * did not run the trap. If I add trap "echo V" WINCH;
6404 * _inside_ group (just before echo 1), it works.
6406 * I conclude it means we don't need to pass active traps here.
6408 *pp++ = (char *) "-c";
6411 while (*++builtin_argv)
6412 *pp++ = *builtin_argv;
6413 *pp++ = (char *) "";
6418 /* *pp = NULL; - is already there */
6422 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6423 /* Don't propagate SIG_IGN to the child */
6424 if (SPECIAL_JOBSTOP_SIGS != 0)
6425 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6426 execve(bb_busybox_exec_path, argv, pp);
6427 /* Fallback. Useful for init=/bin/hush usage etc */
6428 if (argv[0][0] == '/')
6429 execve(argv[0], argv, pp);
6430 xfunc_error_retval = 127;
6431 bb_error_msg_and_die("can't re-execute the shell");
6433 #endif /* !BB_MMU */
6436 static int run_and_free_list(struct pipe *pi);
6438 /* Executing from string: eval, sh -c '...'
6439 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6440 * end_trigger controls how often we stop parsing
6441 * NUL: parse all, execute, return
6442 * ';': parse till ';' or newline, execute, repeat till EOF
6444 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6446 /* Why we need empty flag?
6447 * An obscure corner case "false; ``; echo $?":
6448 * empty command in `` should still set $? to 0.
6449 * But we can't just set $? to 0 at the start,
6450 * this breaks "false; echo `echo $?`" case.
6454 struct pipe *pipe_list;
6456 #if ENABLE_HUSH_INTERACTIVE
6457 if (end_trigger == ';')
6458 inp->promptmode = 0; /* PS1 */
6460 pipe_list = parse_stream(NULL, inp, end_trigger);
6461 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6462 /* If we are in "big" script
6463 * (not in `cmd` or something similar)...
6465 if (pipe_list == ERR_PTR && end_trigger == ';') {
6466 /* Discard cached input (rest of line) */
6467 int ch = inp->last_char;
6468 while (ch != EOF && ch != '\n') {
6469 //bb_error_msg("Discarded:'%c'", ch);
6474 /* This stream isn't empty */
6478 if (!pipe_list && empty)
6479 G.last_exitcode = 0;
6482 debug_print_tree(pipe_list, 0);
6483 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6484 run_and_free_list(pipe_list);
6486 if (G_flag_return_in_progress == 1)
6491 static void parse_and_run_string(const char *s)
6493 struct in_str input;
6494 setup_string_in_str(&input, s);
6495 parse_and_run_stream(&input, '\0');
6498 static void parse_and_run_file(FILE *f)
6500 struct in_str input;
6501 setup_file_in_str(&input, f);
6502 parse_and_run_stream(&input, ';');
6505 #if ENABLE_HUSH_TICK
6506 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6511 char **to_free = NULL;
6515 pid = BB_MMU ? xfork() : xvfork();
6516 if (pid == 0) { /* child */
6517 disable_restore_tty_pgrp_on_exit();
6518 /* Process substitution is not considered to be usual
6519 * 'command execution'.
6520 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6527 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6528 close(channel[0]); /* NB: close _first_, then move fd! */
6529 xmove_fd(channel[1], 1);
6530 /* Prevent it from trying to handle ctrl-z etc */
6531 IF_HUSH_JOB(G.run_list_level = 1;)
6532 # if ENABLE_HUSH_TRAP
6533 /* Awful hack for `trap` or $(trap).
6535 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6536 * contains an example where "trap" is executed in a subshell:
6538 * save_traps=$(trap)
6540 * eval "$save_traps"
6542 * Standard does not say that "trap" in subshell shall print
6543 * parent shell's traps. It only says that its output
6544 * must have suitable form, but then, in the above example
6545 * (which is not supposed to be normative), it implies that.
6547 * bash (and probably other shell) does implement it
6548 * (traps are reset to defaults, but "trap" still shows them),
6549 * but as a result, "trap" logic is hopelessly messed up:
6552 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6553 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6554 * # true | trap <--- trap is in subshell - no output (ditto)
6555 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6556 * trap -- 'echo Ho' SIGWINCH
6557 * # echo `(trap)` <--- in subshell in subshell - output
6558 * trap -- 'echo Ho' SIGWINCH
6559 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6560 * trap -- 'echo Ho' SIGWINCH
6562 * The rules when to forget and when to not forget traps
6563 * get really complex and nonsensical.
6565 * Our solution: ONLY bare $(trap) or `trap` is special.
6567 s = skip_whitespace(s);
6568 if (is_prefixed_with(s, "trap")
6569 && skip_whitespace(s + 4)[0] == '\0'
6571 static const char *const argv[] = { NULL, NULL };
6572 builtin_trap((char**)argv);
6573 fflush_all(); /* important */
6578 reset_traps_to_defaults();
6579 parse_and_run_string(s);
6580 _exit(G.last_exitcode);
6582 /* We re-execute after vfork on NOMMU. This makes this script safe:
6583 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6584 * huge=`cat BIG` # was blocking here forever
6587 re_execute_shell(&to_free,
6597 # if ENABLE_HUSH_FAST
6599 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6600 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6601 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6603 enable_restore_tty_pgrp_on_exit();
6608 return remember_FILE(xfdopen_for_read(channel[0]));
6611 /* Return code is exit status of the process that is run. */
6612 static int process_command_subs(o_string *dest, const char *s)
6615 struct in_str pipe_str;
6617 int status, ch, eol_cnt;
6619 fp = generate_stream_from_string(s, &pid);
6621 /* Now send results of command back into original context */
6622 setup_file_in_str(&pipe_str, fp);
6624 while ((ch = i_getch(&pipe_str)) != EOF) {
6630 o_addchr(dest, '\n');
6633 o_addQchr(dest, ch);
6636 debug_printf("done reading from `cmd` pipe, closing it\n");
6637 fclose_and_forget(fp);
6638 /* We need to extract exitcode. Test case
6639 * "true; echo `sleep 1; false` $?"
6641 safe_waitpid(pid, &status, 0);
6642 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6643 return WEXITSTATUS(status);
6645 #endif /* ENABLE_HUSH_TICK */
6648 static void setup_heredoc(struct redir_struct *redir)
6650 struct fd_pair pair;
6653 /* the _body_ of heredoc (misleading field name) */
6654 const char *heredoc = redir->rd_filename;
6661 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6662 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6666 len = strlen(heredoc);
6668 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6670 xmove_fd(pair.rd, redir->rd_fd);
6672 /* Try writing without forking. Newer kernels have
6673 * dynamically growing pipes. Must use non-blocking write! */
6676 written = write(pair.wr, heredoc, len);
6687 ndelay_off(pair.wr);
6689 /* Okay, pipe buffer was not big enough */
6690 /* Note: we must not create a stray child (bastard? :)
6691 * for the unsuspecting parent process. Child creates a grandchild
6692 * and exits before parent execs the process which consumes heredoc
6693 * (that exec happens after we return from this function) */
6700 disable_restore_tty_pgrp_on_exit();
6701 pid = BB_MMU ? xfork() : xvfork();
6705 close(redir->rd_fd); /* read side of the pipe */
6707 full_write(pair.wr, heredoc, len); /* may loop or block */
6710 /* Delegate blocking writes to another process */
6711 xmove_fd(pair.wr, STDOUT_FILENO);
6712 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6716 #if ENABLE_HUSH_FAST
6718 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6720 enable_restore_tty_pgrp_on_exit();
6726 wait(NULL); /* wait till child has died */
6732 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6733 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6736 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6738 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6739 sq[i].orig_fd = orig;
6740 sq[i].moved_to = moved;
6741 sq[i+1].orig_fd = -1; /* end marker */
6745 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6751 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6752 /* If we collide with an already moved fd... */
6753 if (fd == sq[i].moved_to) {
6754 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6755 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6756 if (sq[i].moved_to < 0) /* what? */
6760 if (fd == sq[i].orig_fd) {
6761 /* Example: echo Hello >/dev/null 1>&2 */
6762 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6767 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6768 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6769 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6770 if (moved_to < 0 && errno != EBADF)
6772 return append_squirrel(sq, i, fd, moved_to);
6775 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6780 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6781 /* If we collide with an already moved fd... */
6782 if (fd == sq[i].orig_fd) {
6784 * "echo 3>FILE 3>&- 3>FILE"
6785 * "echo 3>&- 3>FILE"
6786 * No need for last redirect to insert
6787 * another "need to close 3" indicator.
6789 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6794 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6795 return append_squirrel(sq, i, fd, -1);
6798 /* fd: redirect wants this fd to be used (e.g. 3>file).
6799 * Move all conflicting internally used fds,
6800 * and remember them so that we can restore them later.
6802 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6804 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6807 #if ENABLE_HUSH_INTERACTIVE
6808 if (fd == G.interactive_fd) {
6809 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6810 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6811 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6812 return 1; /* "we closed fd" */
6815 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6816 * (1) Redirect in a forked child. No need to save FILEs' fds,
6817 * we aren't going to use them anymore, ok to trash.
6818 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6819 * but how are we doing to restore them?
6820 * "fileno(fd) = new_fd" can't be done.
6825 /* If this one of script's fds? */
6826 if (save_FILEs_on_redirect(fd, avoid_fd))
6827 return 1; /* yes. "we closed fd" */
6829 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6830 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6831 return 0; /* "we did not close fd" */
6834 static void restore_redirects(struct squirrel *sq)
6838 for (i = 0; sq[i].orig_fd >= 0; i++) {
6839 if (sq[i].moved_to >= 0) {
6840 /* We simply die on error */
6841 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6842 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6844 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6845 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6846 close(sq[i].orig_fd);
6852 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6854 restore_redirected_FILEs();
6857 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6858 static void close_saved_fds_and_FILE_fds(void)
6860 if (G_interactive_fd)
6861 close(G_interactive_fd);
6862 close_all_FILE_list();
6866 static int internally_opened_fd(int fd, struct squirrel *sq)
6870 #if ENABLE_HUSH_INTERACTIVE
6871 if (fd == G.interactive_fd)
6874 /* If this one of script's fds? */
6875 if (fd_in_FILEs(fd))
6878 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6879 if (fd == sq[i].moved_to)
6885 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6886 * and stderr if they are redirected. */
6887 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6889 struct redir_struct *redir;
6891 for (redir = prog->redirects; redir; redir = redir->next) {
6895 if (redir->rd_type == REDIRECT_HEREDOC2) {
6896 /* "rd_fd<<HERE" case */
6897 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6898 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6900 debug_printf_parse("set heredoc '%s'\n",
6901 redir->rd_filename);
6902 setup_heredoc(redir);
6906 if (redir->rd_dup == REDIRFD_TO_FILE) {
6907 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6911 if (redir->rd_filename == NULL) {
6914 * "cmd >" (no filename)
6915 * "cmd > <file" (2nd redirect starts too early)
6917 syntax_error("invalid redirect");
6920 mode = redir_table[redir->rd_type].mode;
6921 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6922 newfd = open_or_warn(p, mode);
6925 /* Error message from open_or_warn can be lost
6926 * if stderr has been redirected, but bash
6927 * and ash both lose it as well
6928 * (though zsh doesn't!)
6932 if (newfd == redir->rd_fd && sqp) {
6933 /* open() gave us precisely the fd we wanted.
6934 * This means that this fd was not busy
6935 * (not opened to anywhere).
6936 * Remember to close it on restore:
6938 *sqp = add_squirrel_closed(*sqp, newfd);
6939 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6942 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6943 newfd = redir->rd_dup;
6946 if (newfd == redir->rd_fd)
6949 /* if "N>FILE": move newfd to redir->rd_fd */
6950 /* if "N>&M": dup newfd to redir->rd_fd */
6951 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6953 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6954 if (newfd == REDIRFD_CLOSE) {
6955 /* "N>&-" means "close me" */
6957 /* ^^^ optimization: saving may already
6958 * have closed it. If not... */
6959 close(redir->rd_fd);
6961 /* Sometimes we do another close on restore, getting EBADF.
6962 * Consider "echo 3>FILE 3>&-"
6963 * first redirect remembers "need to close 3",
6964 * and second redirect closes 3! Restore code then closes 3 again.
6967 /* if newfd is a script fd or saved fd, simulate EBADF */
6968 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6970 //bb_perror_msg_and_die("can't duplicate file descriptor");
6971 newfd = -1; /* same effect as code above */
6973 xdup2(newfd, redir->rd_fd);
6974 if (redir->rd_dup == REDIRFD_TO_FILE)
6975 /* "rd_fd > FILE" */
6977 /* else: "rd_fd > rd_dup" */
6983 static char *find_in_path(const char *arg)
6986 const char *PATH = get_local_var_value("PATH");
6992 const char *end = strchrnul(PATH, ':');
6993 int sz = end - PATH; /* must be int! */
6997 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6999 /* We have xxx::yyyy in $PATH,
7000 * it means "use current dir" */
7003 if (access(ret, F_OK) == 0)
7016 static const struct built_in_command *find_builtin_helper(const char *name,
7017 const struct built_in_command *x,
7018 const struct built_in_command *end)
7021 if (strcmp(name, x->b_cmd) != 0) {
7025 debug_printf_exec("found builtin '%s'\n", name);
7030 static const struct built_in_command *find_builtin1(const char *name)
7032 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7034 static const struct built_in_command *find_builtin(const char *name)
7036 const struct built_in_command *x = find_builtin1(name);
7039 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7042 #if ENABLE_HUSH_FUNCTIONS
7043 static struct function **find_function_slot(const char *name)
7045 struct function **funcpp = &G.top_func;
7047 if (strcmp(name, (*funcpp)->name) == 0) {
7050 funcpp = &(*funcpp)->next;
7055 static const struct function *find_function(const char *name)
7057 const struct function *funcp = *find_function_slot(name);
7059 debug_printf_exec("found function '%s'\n", name);
7063 /* Note: takes ownership on name ptr */
7064 static struct function *new_function(char *name)
7066 struct function **funcpp = find_function_slot(name);
7067 struct function *funcp = *funcpp;
7069 if (funcp != NULL) {
7070 struct command *cmd = funcp->parent_cmd;
7071 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7073 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7075 /* Note: if !funcp->body, do not free body_as_string!
7076 * This is a special case of "-F name body" function:
7077 * body_as_string was not malloced! */
7079 free_pipe_list(funcp->body);
7081 free(funcp->body_as_string);
7085 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7086 cmd->argv[0] = funcp->name;
7087 cmd->group = funcp->body;
7089 cmd->group_as_string = funcp->body_as_string;
7093 debug_printf_exec("remembering new function '%s'\n", name);
7094 funcp = *funcpp = xzalloc(sizeof(*funcp));
7095 /*funcp->next = NULL;*/
7102 # if ENABLE_HUSH_UNSET
7103 static void unset_func(const char *name)
7105 struct function **funcpp = find_function_slot(name);
7106 struct function *funcp = *funcpp;
7108 if (funcp != NULL) {
7109 debug_printf_exec("freeing function '%s'\n", funcp->name);
7110 *funcpp = funcp->next;
7111 /* funcp is unlinked now, deleting it.
7112 * Note: if !funcp->body, the function was created by
7113 * "-F name body", do not free ->body_as_string
7114 * and ->name as they were not malloced. */
7116 free_pipe_list(funcp->body);
7119 free(funcp->body_as_string);
7128 #define exec_function(to_free, funcp, argv) \
7129 exec_function(funcp, argv)
7131 static void exec_function(char ***to_free,
7132 const struct function *funcp,
7133 char **argv) NORETURN;
7134 static void exec_function(char ***to_free,
7135 const struct function *funcp,
7141 argv[0] = G.global_argv[0];
7142 G.global_argv = argv;
7143 G.global_argc = n = 1 + string_array_len(argv + 1);
7145 // Example when we are here: "cmd | func"
7146 // func will run with saved-redirect fds open.
7147 // $ f() { echo /proc/self/fd/*; }
7149 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7150 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7153 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7154 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7155 // They are CLOEXEC so external programs won't see them, but
7156 // for "more correctness" we might want to close those extra fds here:
7157 //? close_saved_fds_and_FILE_fds();
7159 /* "we are in function, ok to use return" */
7160 G_flag_return_in_progress = -1;
7161 IF_HUSH_LOCAL(G.func_nest_level++;)
7163 /* On MMU, funcp->body is always non-NULL */
7164 n = run_list(funcp->body);
7168 //? close_saved_fds_and_FILE_fds();
7170 //TODO: check whether "true | func_with_return" works
7172 re_execute_shell(to_free,
7173 funcp->body_as_string,
7180 static int run_function(const struct function *funcp, char **argv)
7186 save_and_replace_G_args(&sv, argv);
7188 /* "we are in function, ok to use return" */
7189 sv_flg = G_flag_return_in_progress;
7190 G_flag_return_in_progress = -1;
7191 IF_HUSH_LOCAL(G.func_nest_level++;)
7193 /* On MMU, funcp->body is always non-NULL */
7196 /* Function defined by -F */
7197 parse_and_run_string(funcp->body_as_string);
7198 rc = G.last_exitcode;
7202 rc = run_list(funcp->body);
7205 # if ENABLE_HUSH_LOCAL
7207 struct variable *var;
7208 struct variable **var_pp;
7210 var_pp = &G.top_var;
7211 while ((var = *var_pp) != NULL) {
7212 if (var->func_nest_level < G.func_nest_level) {
7213 var_pp = &var->next;
7217 if (var->flg_export)
7218 bb_unsetenv(var->varstr);
7219 /* Remove from global list */
7220 *var_pp = var->next;
7226 G.func_nest_level--;
7229 G_flag_return_in_progress = sv_flg;
7231 restore_G_args(&sv, argv);
7235 #endif /* ENABLE_HUSH_FUNCTIONS */
7239 #define exec_builtin(to_free, x, argv) \
7240 exec_builtin(x, argv)
7242 #define exec_builtin(to_free, x, argv) \
7243 exec_builtin(to_free, argv)
7245 static void exec_builtin(char ***to_free,
7246 const struct built_in_command *x,
7247 char **argv) NORETURN;
7248 static void exec_builtin(char ***to_free,
7249 const struct built_in_command *x,
7255 //? close_saved_fds_and_FILE_fds();
7256 rcode = x->b_function(argv);
7261 /* On NOMMU, we must never block!
7262 * Example: { sleep 99 | read line; } & echo Ok
7264 re_execute_shell(to_free,
7273 static void execvp_or_die(char **argv) NORETURN;
7274 static void execvp_or_die(char **argv)
7277 debug_printf_exec("execing '%s'\n", argv[0]);
7278 /* Don't propagate SIG_IGN to the child */
7279 if (SPECIAL_JOBSTOP_SIGS != 0)
7280 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7281 execvp(argv[0], argv);
7283 if (errno == EACCES) e = 126;
7284 if (errno == ENOENT) e = 127;
7285 bb_perror_msg("can't execute '%s'", argv[0]);
7289 #if ENABLE_HUSH_MODE_X
7290 static void dump_cmd_in_x_mode(char **argv)
7292 if (G_x_mode && argv) {
7293 /* We want to output the line in one write op */
7301 len += strlen(argv[n++]) + 1;
7307 p += sprintf(p, " %s", argv[n++]);
7315 # define dump_cmd_in_x_mode(argv) ((void)0)
7319 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7320 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7321 #define pseudo_exec(nommu_save, command, argv_expanded) \
7322 pseudo_exec(command, argv_expanded)
7325 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7327 * Don't exit() here. If you don't exec, use _exit instead.
7328 * The at_exit handlers apparently confuse the calling process,
7329 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7331 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7332 char **argv, int assignment_cnt,
7333 char **argv_expanded) NORETURN;
7334 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7335 char **argv, int assignment_cnt,
7336 char **argv_expanded)
7340 new_env = expand_assignments(argv, assignment_cnt);
7341 dump_cmd_in_x_mode(new_env);
7343 if (!argv[assignment_cnt]) {
7344 /* Case when we are here: ... | var=val | ...
7345 * (note that we do not exit early, i.e., do not optimize out
7346 * expand_assignments(): think about ... | var=`sleep 1` | ...
7348 free_strings(new_env);
7349 _exit(EXIT_SUCCESS);
7353 set_vars_and_save_old(new_env);
7354 free(new_env); /* optional */
7355 /* we can also destroy set_vars_and_save_old's return value,
7358 nommu_save->new_env = new_env;
7359 nommu_save->old_vars = set_vars_and_save_old(new_env);
7362 if (argv_expanded) {
7363 argv = argv_expanded;
7365 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7367 nommu_save->argv = argv;
7370 dump_cmd_in_x_mode(argv);
7372 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7373 if (strchr(argv[0], '/') != NULL)
7377 #if ENABLE_HUSH_FUNCTIONS
7378 /* Check if the command matches any functions (this goes before bltins) */
7380 const struct function *funcp = find_function(argv[0]);
7382 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7387 /* Check if the command matches any of the builtins.
7388 * Depending on context, this might be redundant. But it's
7389 * easier to waste a few CPU cycles than it is to figure out
7390 * if this is one of those cases.
7393 /* On NOMMU, it is more expensive to re-execute shell
7394 * just in order to run echo or test builtin.
7395 * It's better to skip it here and run corresponding
7396 * non-builtin later. */
7397 const struct built_in_command *x;
7398 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7400 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7404 #if ENABLE_FEATURE_SH_STANDALONE
7405 /* Check if the command matches any busybox applets */
7407 int a = find_applet_by_name(argv[0]);
7409 # if BB_MMU /* see above why on NOMMU it is not allowed */
7410 if (APPLET_IS_NOEXEC(a)) {
7411 /* Do not leak open fds from opened script files etc.
7412 * Testcase: interactive "ls -l /proc/self/fd"
7413 * should not show tty fd open.
7415 close_saved_fds_and_FILE_fds();
7416 //FIXME: should also close saved redir fds
7417 /* Without this, "rm -i FILE" can't be ^C'ed: */
7418 switch_off_special_sigs(G.special_sig_mask);
7419 debug_printf_exec("running applet '%s'\n", argv[0]);
7420 run_noexec_applet_and_exit(a, argv[0], argv);
7423 /* Re-exec ourselves */
7424 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7425 /* Don't propagate SIG_IGN to the child */
7426 if (SPECIAL_JOBSTOP_SIGS != 0)
7427 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7428 execv(bb_busybox_exec_path, argv);
7429 /* If they called chroot or otherwise made the binary no longer
7430 * executable, fall through */
7435 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7438 execvp_or_die(argv);
7441 /* Called after [v]fork() in run_pipe
7443 static void pseudo_exec(nommu_save_t *nommu_save,
7444 struct command *command,
7445 char **argv_expanded) NORETURN;
7446 static void pseudo_exec(nommu_save_t *nommu_save,
7447 struct command *command,
7448 char **argv_expanded)
7450 if (command->argv) {
7451 pseudo_exec_argv(nommu_save, command->argv,
7452 command->assignment_cnt, argv_expanded);
7455 if (command->group) {
7456 /* Cases when we are here:
7459 * ... | ( list ) | ...
7460 * ... | { list } | ...
7464 debug_printf_exec("pseudo_exec: run_list\n");
7465 reset_traps_to_defaults();
7466 rcode = run_list(command->group);
7467 /* OK to leak memory by not calling free_pipe_list,
7468 * since this process is about to exit */
7471 re_execute_shell(&nommu_save->argv_from_re_execing,
7472 command->group_as_string,
7479 /* Case when we are here: ... | >file */
7480 debug_printf_exec("pseudo_exec'ed null command\n");
7481 _exit(EXIT_SUCCESS);
7485 static const char *get_cmdtext(struct pipe *pi)
7491 /* This is subtle. ->cmdtext is created only on first backgrounding.
7492 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7493 * On subsequent bg argv is trashed, but we won't use it */
7497 argv = pi->cmds[0].argv;
7499 pi->cmdtext = xzalloc(1);
7504 len += strlen(*argv) + 1;
7508 argv = pi->cmds[0].argv;
7510 p = stpcpy(p, *argv);
7517 static void remove_job_from_table(struct pipe *pi)
7519 struct pipe *prev_pipe;
7521 if (pi == G.job_list) {
7522 G.job_list = pi->next;
7524 prev_pipe = G.job_list;
7525 while (prev_pipe->next != pi)
7526 prev_pipe = prev_pipe->next;
7527 prev_pipe->next = pi->next;
7531 G.last_jobid = G.job_list->jobid;
7534 static void delete_finished_job(struct pipe *pi)
7536 remove_job_from_table(pi);
7540 static void clean_up_last_dead_job(void)
7542 if (G.job_list && !G.job_list->alive_cmds)
7543 delete_finished_job(G.job_list);
7546 static void insert_job_into_table(struct pipe *pi)
7548 struct pipe *job, **jobp;
7551 clean_up_last_dead_job();
7553 /* Find the end of the list, and find next job ID to use */
7556 while ((job = *jobp) != NULL) {
7563 /* Create a new job struct at the end */
7564 job = *jobp = xmemdup(pi, sizeof(*pi));
7566 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7567 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7568 for (i = 0; i < pi->num_cmds; i++) {
7569 job->cmds[i].pid = pi->cmds[i].pid;
7570 /* all other fields are not used and stay zero */
7572 job->cmdtext = xstrdup(get_cmdtext(pi));
7574 if (G_interactive_fd)
7575 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7576 G.last_jobid = job->jobid;
7580 static int job_exited_or_stopped(struct pipe *pi)
7584 if (pi->alive_cmds != pi->stopped_cmds)
7587 /* All processes in fg pipe have exited or stopped */
7591 rcode = pi->cmds[i].cmd_exitcode;
7592 /* usually last process gives overall exitstatus,
7593 * but with "set -o pipefail", last *failed* process does */
7594 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7597 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7601 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7608 dead = WIFEXITED(status) || WIFSIGNALED(status);
7611 if (WIFSTOPPED(status))
7612 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7613 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7614 if (WIFSIGNALED(status))
7615 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7616 childpid, WTERMSIG(status), WEXITSTATUS(status));
7617 if (WIFEXITED(status))
7618 debug_printf_jobs("pid %d exited, exitcode %d\n",
7619 childpid, WEXITSTATUS(status));
7621 /* Were we asked to wait for a fg pipe? */
7623 i = fg_pipe->num_cmds;
7628 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7629 if (fg_pipe->cmds[i].pid != childpid)
7633 fg_pipe->cmds[i].pid = 0;
7634 fg_pipe->alive_cmds--;
7635 ex = WEXITSTATUS(status);
7636 /* bash prints killer signal's name for *last*
7637 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7638 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7640 if (WIFSIGNALED(status)) {
7641 int sig = WTERMSIG(status);
7642 if (i == fg_pipe->num_cmds-1)
7643 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7644 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7645 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7646 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7647 * Maybe we need to use sig | 128? */
7650 fg_pipe->cmds[i].cmd_exitcode = ex;
7652 fg_pipe->stopped_cmds++;
7654 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7655 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7656 rcode = job_exited_or_stopped(fg_pipe);
7658 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7659 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7660 * and "killall -STOP cat" */
7661 if (G_interactive_fd) {
7663 if (fg_pipe->alive_cmds != 0)
7664 insert_job_into_table(fg_pipe);
7668 if (fg_pipe->alive_cmds == 0)
7671 /* There are still running processes in the fg_pipe */
7674 /* It wasn't in fg_pipe, look for process in bg pipes */
7678 /* We were asked to wait for bg or orphaned children */
7679 /* No need to remember exitcode in this case */
7680 for (pi = G.job_list; pi; pi = pi->next) {
7681 for (i = 0; i < pi->num_cmds; i++) {
7682 if (pi->cmds[i].pid == childpid)
7683 goto found_pi_and_prognum;
7686 /* Happens when shell is used as init process (init=/bin/sh) */
7687 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7688 return -1; /* this wasn't a process from fg_pipe */
7690 found_pi_and_prognum:
7693 int rcode = WEXITSTATUS(status);
7694 if (WIFSIGNALED(status))
7695 rcode = 128 + WTERMSIG(status);
7696 pi->cmds[i].cmd_exitcode = rcode;
7697 if (G.last_bg_pid == pi->cmds[i].pid)
7698 G.last_bg_pid_exitcode = rcode;
7699 pi->cmds[i].pid = 0;
7701 if (!pi->alive_cmds) {
7702 if (G_interactive_fd) {
7703 printf(JOB_STATUS_FORMAT, pi->jobid,
7704 "Done", pi->cmdtext);
7705 delete_finished_job(pi);
7708 * bash deletes finished jobs from job table only in interactive mode,
7709 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7710 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7711 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7712 * We only retain one "dead" job, if it's the single job on the list.
7713 * This covers most of real-world scenarios where this is useful.
7715 if (pi != G.job_list)
7716 delete_finished_job(pi);
7724 return -1; /* this wasn't a process from fg_pipe */
7727 /* Check to see if any processes have exited -- if they have,
7728 * figure out why and see if a job has completed.
7730 * If non-NULL fg_pipe: wait for its completion or stop.
7731 * Return its exitcode or zero if stopped.
7733 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7734 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7735 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7736 * or 0 if no children changed status.
7738 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7739 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7740 * or 0 if no children changed status.
7742 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7748 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7750 attributes = WUNTRACED;
7751 if (fg_pipe == NULL)
7752 attributes |= WNOHANG;
7755 #if ENABLE_HUSH_FAST
7756 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7757 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7758 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7759 /* There was neither fork nor SIGCHLD since last waitpid */
7760 /* Avoid doing waitpid syscall if possible */
7761 if (!G.we_have_children) {
7765 if (fg_pipe == NULL) { /* is WNOHANG set? */
7766 /* We have children, but they did not exit
7767 * or stop yet (we saw no SIGCHLD) */
7770 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7774 /* Do we do this right?
7775 * bash-3.00# sleep 20 | false
7777 * [3]+ Stopped sleep 20 | false
7778 * bash-3.00# echo $?
7779 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7780 * [hush 1.14.0: yes we do it right]
7784 #if ENABLE_HUSH_FAST
7786 i = G.count_SIGCHLD;
7788 childpid = waitpid(-1, &status, attributes);
7789 if (childpid <= 0) {
7790 if (childpid && errno != ECHILD)
7791 bb_perror_msg("waitpid");
7792 #if ENABLE_HUSH_FAST
7793 else { /* Until next SIGCHLD, waitpid's are useless */
7794 G.we_have_children = (childpid == 0);
7795 G.handled_SIGCHLD = i;
7796 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7799 /* ECHILD (no children), or 0 (no change in children status) */
7803 rcode = process_wait_result(fg_pipe, childpid, status);
7805 /* fg_pipe exited or stopped */
7808 if (childpid == waitfor_pid) {
7809 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7810 rcode = WEXITSTATUS(status);
7811 if (WIFSIGNALED(status))
7812 rcode = 128 + WTERMSIG(status);
7813 if (WIFSTOPPED(status))
7814 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7815 rcode = 128 + WSTOPSIG(status);
7817 break; /* "wait PID" called us, give it exitcode+1 */
7819 /* This wasn't one of our processes, or */
7820 /* fg_pipe still has running processes, do waitpid again */
7821 } /* while (waitpid succeeds)... */
7827 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7830 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7831 if (G_saved_tty_pgrp) {
7832 /* Job finished, move the shell to the foreground */
7833 p = getpgrp(); /* our process group id */
7834 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7835 tcsetpgrp(G_interactive_fd, p);
7841 /* Start all the jobs, but don't wait for anything to finish.
7844 * Return code is normally -1, when the caller has to wait for children
7845 * to finish to determine the exit status of the pipe. If the pipe
7846 * is a simple builtin command, however, the action is done by the
7847 * time run_pipe returns, and the exit code is provided as the
7850 * Returns -1 only if started some children. IOW: we have to
7851 * mask out retvals of builtins etc with 0xff!
7853 * The only case when we do not need to [v]fork is when the pipe
7854 * is single, non-backgrounded, non-subshell command. Examples:
7855 * cmd ; ... { list } ; ...
7856 * cmd && ... { list } && ...
7857 * cmd || ... { list } || ...
7858 * If it is, then we can run cmd as a builtin, NOFORK,
7859 * or (if SH_STANDALONE) an applet, and we can run the { list }
7860 * with run_list. If it isn't one of these, we fork and exec cmd.
7862 * Cases when we must fork:
7863 * non-single: cmd | cmd
7864 * backgrounded: cmd & { list } &
7865 * subshell: ( list ) [&]
7867 #if !ENABLE_HUSH_MODE_X
7868 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7869 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7871 static int redirect_and_varexp_helper(char ***new_env_p,
7872 struct variable **old_vars_p,
7873 struct command *command,
7874 struct squirrel **sqp,
7875 char **argv_expanded)
7877 /* setup_redirects acts on file descriptors, not FILEs.
7878 * This is perfect for work that comes after exec().
7879 * Is it really safe for inline use? Experimentally,
7880 * things seem to work. */
7881 int rcode = setup_redirects(command, sqp);
7883 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7884 *new_env_p = new_env;
7885 dump_cmd_in_x_mode(new_env);
7886 dump_cmd_in_x_mode(argv_expanded);
7888 *old_vars_p = set_vars_and_save_old(new_env);
7892 static NOINLINE int run_pipe(struct pipe *pi)
7894 static const char *const null_ptr = NULL;
7898 struct command *command;
7899 char **argv_expanded;
7901 struct squirrel *squirrel = NULL;
7904 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7907 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7908 * Result should be 3 lines: q w e, qwe, q w e
7910 G.ifs = get_local_var_value("IFS");
7914 IF_HUSH_JOB(pi->pgrp = -1;)
7915 pi->stopped_cmds = 0;
7916 command = &pi->cmds[0];
7917 argv_expanded = NULL;
7919 if (pi->num_cmds != 1
7920 || pi->followup == PIPE_BG
7921 || command->cmd_type == CMD_SUBSHELL
7928 debug_printf_exec(": group:%p argv:'%s'\n",
7929 command->group, command->argv ? command->argv[0] : "NONE");
7931 if (command->group) {
7932 #if ENABLE_HUSH_FUNCTIONS
7933 if (command->cmd_type == CMD_FUNCDEF) {
7934 /* "executing" func () { list } */
7935 struct function *funcp;
7937 funcp = new_function(command->argv[0]);
7938 /* funcp->name is already set to argv[0] */
7939 funcp->body = command->group;
7941 funcp->body_as_string = command->group_as_string;
7942 command->group_as_string = NULL;
7944 command->group = NULL;
7945 command->argv[0] = NULL;
7946 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7947 funcp->parent_cmd = command;
7948 command->child_func = funcp;
7950 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7952 return EXIT_SUCCESS;
7956 debug_printf("non-subshell group\n");
7957 rcode = 1; /* exitcode if redir failed */
7958 if (setup_redirects(command, &squirrel) == 0) {
7959 debug_printf_exec(": run_list\n");
7960 rcode = run_list(command->group) & 0xff;
7962 restore_redirects(squirrel);
7963 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7965 debug_printf_exec("run_pipe: return %d\n", rcode);
7969 argv = command->argv ? command->argv : (char **) &null_ptr;
7971 const struct built_in_command *x;
7972 #if ENABLE_HUSH_FUNCTIONS
7973 const struct function *funcp;
7977 char **new_env = NULL;
7978 struct variable *old_vars = NULL;
7980 if (argv[command->assignment_cnt] == NULL) {
7981 /* Assignments, but no command */
7982 /* Ensure redirects take effect (that is, create files).
7983 * Try "a=t >file" */
7984 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7985 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7986 /* Set shell variables */
7990 if (set_local_var(*argv, /*flag:*/ 0)) {
7991 /* assignment to readonly var / putenv error? */
7997 /* Redirect error sets $? to 1. Otherwise,
7998 * if evaluating assignment value set $?, retain it.
7999 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8001 rcode = G.last_exitcode;
8002 /* Exit, _skipping_ variable restoring code: */
8003 goto clean_up_and_ret0;
8005 #else /* Older, bigger, but more correct code */
8007 rcode = setup_redirects(command, &squirrel);
8008 restore_redirects(squirrel);
8009 /* Set shell variables */
8011 bb_putchar_stderr('+');
8013 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8015 fprintf(stderr, " %s", p);
8016 debug_printf_exec("set shell var:'%s'->'%s'\n",
8018 if (set_local_var(p, /*flag:*/ 0)) {
8019 /* assignment to readonly var / putenv error? */
8025 bb_putchar_stderr('\n');
8026 /* Redirect error sets $? to 1. Otherwise,
8027 * if evaluating assignment value set $?, retain it.
8028 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8030 rcode = G.last_exitcode;
8031 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8033 debug_printf_exec("run_pipe: return %d\n", rcode);
8038 /* Expand the rest into (possibly) many strings each */
8040 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8041 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8045 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8048 /* if someone gives us an empty string: `cmd with empty output` */
8049 if (!argv_expanded[0]) {
8050 free(argv_expanded);
8052 return G.last_exitcode;
8055 #if ENABLE_HUSH_FUNCTIONS
8056 /* Check if argv[0] matches any functions (this goes before bltins) */
8057 funcp = find_function(argv_expanded[0]);
8061 x = find_builtin(argv_expanded[0]);
8064 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8065 debug_printf("exec with redirects only\n");
8066 rcode = setup_redirects(command, NULL);
8067 /* rcode=1 can be if redir file can't be opened */
8068 goto clean_up_and_ret1;
8071 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8074 debug_printf_exec(": builtin '%s' '%s'...\n",
8075 x->b_cmd, argv_expanded[1]);
8077 rcode = x->b_function(argv_expanded) & 0xff;
8080 #if ENABLE_HUSH_FUNCTIONS
8082 # if ENABLE_HUSH_LOCAL
8083 struct variable **sv;
8084 sv = G.shadowed_vars_pp;
8085 G.shadowed_vars_pp = &old_vars;
8087 debug_printf_exec(": function '%s' '%s'...\n",
8088 funcp->name, argv_expanded[1]);
8089 rcode = run_function(funcp, argv_expanded) & 0xff;
8090 # if ENABLE_HUSH_LOCAL
8091 G.shadowed_vars_pp = sv;
8097 unset_vars(new_env);
8099 /* clean_up_and_ret0: */
8100 restore_redirects(squirrel);
8102 * Try "usleep 99999999" + ^C + "echo $?"
8103 * with FEATURE_SH_NOFORK=y.
8106 /* It was builtin or nofork.
8107 * if this would be a real fork/execed program,
8108 * it should have died if a fatal sig was received.
8109 * But OTOH, there was no separate process,
8110 * the sig was sent to _shell_, not to non-existing
8112 * Let's just handle ^C only, this one is obvious:
8113 * we aren't ok with exitcode 0 when ^C was pressed
8114 * during builtin/nofork.
8116 if (sigismember(&G.pending_set, SIGINT))
8117 rcode = 128 + SIGINT;
8120 free(argv_expanded);
8121 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8123 debug_printf_exec("run_pipe return %d\n", rcode);
8127 if (ENABLE_FEATURE_SH_NOFORK && NUM_APPLETS > 1) {
8128 int n = find_applet_by_name(argv_expanded[0]);
8129 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8130 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8132 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8133 argv_expanded[0], argv_expanded[1]);
8135 * Note: signals (^C) can't interrupt here.
8136 * We remember them and they will be acted upon
8137 * after applet returns.
8138 * This makes applets which can run for a long time
8139 * and/or wait for user input ineligible for NOFORK:
8140 * for example, "yes" or "rm" (rm -i waits for input).
8142 rcode = run_nofork_applet(n, argv_expanded);
8144 goto clean_up_and_ret;
8147 /* It is neither builtin nor applet. We must fork. */
8151 /* NB: argv_expanded may already be created, and that
8152 * might include `cmd` runs! Do not rerun it! We *must*
8153 * use argv_expanded if it's non-NULL */
8155 /* Going to fork a child per each pipe member */
8160 while (cmd_no < pi->num_cmds) {
8161 struct fd_pair pipefds;
8163 volatile nommu_save_t nommu_save;
8164 nommu_save.new_env = NULL;
8165 nommu_save.old_vars = NULL;
8166 nommu_save.argv = NULL;
8167 nommu_save.argv_from_re_execing = NULL;
8169 command = &pi->cmds[cmd_no];
8171 if (command->argv) {
8172 debug_printf_exec(": pipe member '%s' '%s'...\n",
8173 command->argv[0], command->argv[1]);
8175 debug_printf_exec(": pipe member with no argv\n");
8178 /* pipes are inserted between pairs of commands */
8181 if (cmd_no < pi->num_cmds)
8182 xpiped_pair(pipefds);
8184 command->pid = BB_MMU ? fork() : vfork();
8185 if (!command->pid) { /* child */
8187 disable_restore_tty_pgrp_on_exit();
8188 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8190 /* Every child adds itself to new process group
8191 * with pgid == pid_of_first_child_in_pipe */
8192 if (G.run_list_level == 1 && G_interactive_fd) {
8195 if (pgrp < 0) /* true for 1st process only */
8197 if (setpgid(0, pgrp) == 0
8198 && pi->followup != PIPE_BG
8199 && G_saved_tty_pgrp /* we have ctty */
8201 /* We do it in *every* child, not just first,
8203 tcsetpgrp(G_interactive_fd, pgrp);
8207 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8208 /* 1st cmd in backgrounded pipe
8209 * should have its stdin /dev/null'ed */
8211 if (open(bb_dev_null, O_RDONLY))
8212 xopen("/", O_RDONLY);
8214 xmove_fd(next_infd, 0);
8216 xmove_fd(pipefds.wr, 1);
8219 /* Like bash, explicit redirects override pipes,
8220 * and the pipe fd (fd#1) is available for dup'ing:
8221 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8222 * of cmd1 goes into pipe.
8224 if (setup_redirects(command, NULL)) {
8225 /* Happens when redir file can't be opened:
8226 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8228 * hush: can't open '/qwe/rty': No such file or directory
8230 * (echo BAR is not executed, it hits _exit(1) below)
8235 /* Stores to nommu_save list of env vars putenv'ed
8236 * (NOMMU, on MMU we don't need that) */
8237 /* cast away volatility... */
8238 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8239 /* pseudo_exec() does not return */
8242 /* parent or error */
8243 #if ENABLE_HUSH_FAST
8245 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8247 enable_restore_tty_pgrp_on_exit();
8249 /* Clean up after vforked child */
8250 free(nommu_save.argv);
8251 free(nommu_save.argv_from_re_execing);
8252 unset_vars(nommu_save.new_env);
8253 add_vars(nommu_save.old_vars);
8255 free(argv_expanded);
8256 argv_expanded = NULL;
8257 if (command->pid < 0) { /* [v]fork failed */
8258 /* Clearly indicate, was it fork or vfork */
8259 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8263 /* Second and next children need to know pid of first one */
8265 pi->pgrp = command->pid;
8271 if (cmd_no < pi->num_cmds)
8273 /* Pass read (output) pipe end to next iteration */
8274 next_infd = pipefds.rd;
8277 if (!pi->alive_cmds) {
8279 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8284 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8288 /* NB: called by pseudo_exec, and therefore must not modify any
8289 * global data until exec/_exit (we can be a child after vfork!) */
8290 static int run_list(struct pipe *pi)
8292 #if ENABLE_HUSH_CASE
8293 char *case_word = NULL;
8295 #if ENABLE_HUSH_LOOPS
8296 struct pipe *loop_top = NULL;
8297 char **for_lcur = NULL;
8298 char **for_list = NULL;
8300 smallint last_followup;
8302 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8303 smalluint cond_code = 0;
8305 enum { cond_code = 0 };
8308 smallint rword; /* RES_foo */
8309 smallint last_rword; /* ditto */
8312 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8315 #if ENABLE_HUSH_LOOPS
8316 /* Check syntax for "for" */
8319 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8320 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8322 /* current word is FOR or IN (BOLD in comments below) */
8323 if (cpipe->next == NULL) {
8324 syntax_error("malformed for");
8326 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8329 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8330 if (cpipe->next->res_word == RES_DO)
8332 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8333 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8334 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8336 syntax_error("malformed for");
8338 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8345 /* Past this point, all code paths should jump to ret: label
8346 * in order to return, no direct "return" statements please.
8347 * This helps to ensure that no memory is leaked. */
8355 last_rword = RES_XXXX;
8357 last_followup = PIPE_SEQ;
8358 rcode = G.last_exitcode;
8360 /* Go through list of pipes, (maybe) executing them. */
8361 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8363 int sv_errexit_depth;
8367 if (G_flag_return_in_progress == 1)
8370 IF_HAS_KEYWORDS(rword = pi->res_word;)
8371 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8372 rword, cond_code, last_rword);
8374 sv_errexit_depth = G.errexit_depth;
8377 rword == RES_IF || rword == RES_ELIF ||
8379 pi->followup != PIPE_SEQ
8383 #if ENABLE_HUSH_LOOPS
8384 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8385 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8387 /* start of a loop: remember where loop starts */
8392 /* Still in the same "if...", "then..." or "do..." branch? */
8393 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8394 if ((rcode == 0 && last_followup == PIPE_OR)
8395 || (rcode != 0 && last_followup == PIPE_AND)
8397 /* It is "<true> || CMD" or "<false> && CMD"
8398 * and we should not execute CMD */
8399 debug_printf_exec("skipped cmd because of || or &&\n");
8400 last_followup = pi->followup;
8401 goto dont_check_jobs_but_continue;
8404 last_followup = pi->followup;
8405 IF_HAS_KEYWORDS(last_rword = rword;)
8408 if (rword == RES_THEN) {
8409 /* if false; then ... fi has exitcode 0! */
8410 G.last_exitcode = rcode = EXIT_SUCCESS;
8411 /* "if <false> THEN cmd": skip cmd */
8415 if (rword == RES_ELSE || rword == RES_ELIF) {
8416 /* "if <true> then ... ELSE/ELIF cmd":
8417 * skip cmd and all following ones */
8422 #if ENABLE_HUSH_LOOPS
8423 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8425 /* first loop through for */
8427 static const char encoded_dollar_at[] ALIGN1 = {
8428 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8429 }; /* encoded representation of "$@" */
8430 static const char *const encoded_dollar_at_argv[] = {
8431 encoded_dollar_at, NULL
8432 }; /* argv list with one element: "$@" */
8435 vals = (char**)encoded_dollar_at_argv;
8436 if (pi->next->res_word == RES_IN) {
8437 /* if no variable values after "in" we skip "for" */
8438 if (!pi->next->cmds[0].argv) {
8439 G.last_exitcode = rcode = EXIT_SUCCESS;
8440 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8443 vals = pi->next->cmds[0].argv;
8444 } /* else: "for var; do..." -> assume "$@" list */
8445 /* create list of variable values */
8446 debug_print_strings("for_list made from", vals);
8447 for_list = expand_strvec_to_strvec(vals);
8448 for_lcur = for_list;
8449 debug_print_strings("for_list", for_list);
8452 /* "for" loop is over, clean up */
8458 /* Insert next value from for_lcur */
8459 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8460 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8463 if (rword == RES_IN) {
8464 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8466 if (rword == RES_DONE) {
8467 continue; /* "done" has no cmds too */
8470 #if ENABLE_HUSH_CASE
8471 if (rword == RES_CASE) {
8472 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8473 case_word = expand_strvec_to_string(pi->cmds->argv);
8474 unbackslash(case_word);
8477 if (rword == RES_MATCH) {
8480 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8481 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8483 /* all prev words didn't match, does this one match? */
8484 argv = pi->cmds->argv;
8486 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8487 /* TODO: which FNM_xxx flags to use? */
8488 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8489 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8491 if (cond_code == 0) { /* match! we will execute this branch */
8493 case_word = NULL; /* make future "word)" stop */
8500 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8501 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8503 continue; /* not matched yet, skip this pipe */
8505 if (rword == RES_ESAC) {
8506 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8508 /* "case" did not match anything: still set $? (to 0) */
8509 G.last_exitcode = rcode = EXIT_SUCCESS;
8513 /* Just pressing <enter> in shell should check for jobs.
8514 * OTOH, in non-interactive shell this is useless
8515 * and only leads to extra job checks */
8516 if (pi->num_cmds == 0) {
8517 if (G_interactive_fd)
8518 goto check_jobs_and_continue;
8522 /* After analyzing all keywords and conditions, we decided
8523 * to execute this pipe. NB: have to do checkjobs(NULL)
8524 * after run_pipe to collect any background children,
8525 * even if list execution is to be stopped. */
8526 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8527 #if ENABLE_HUSH_LOOPS
8528 G.flag_break_continue = 0;
8530 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8532 /* We ran a builtin, function, or group.
8533 * rcode is already known
8534 * and we don't need to wait for anything. */
8535 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8536 G.last_exitcode = rcode;
8537 check_and_run_traps();
8538 #if ENABLE_HUSH_LOOPS
8539 /* Was it "break" or "continue"? */
8540 if (G.flag_break_continue) {
8541 smallint fbc = G.flag_break_continue;
8542 /* We might fall into outer *loop*,
8543 * don't want to break it too */
8545 G.depth_break_continue--;
8546 if (G.depth_break_continue == 0)
8547 G.flag_break_continue = 0;
8548 /* else: e.g. "continue 2" should *break* once, *then* continue */
8549 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8550 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8551 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8554 /* "continue": simulate end of loop */
8559 if (G_flag_return_in_progress == 1) {
8560 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8563 } else if (pi->followup == PIPE_BG) {
8564 /* What does bash do with attempts to background builtins? */
8565 /* even bash 3.2 doesn't do that well with nested bg:
8566 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8567 * I'm NOT treating inner &'s as jobs */
8569 if (G.run_list_level == 1)
8570 insert_job_into_table(pi);
8572 /* Last command's pid goes to $! */
8573 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8574 G.last_bg_pid_exitcode = 0;
8575 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8576 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8577 rcode = EXIT_SUCCESS;
8581 if (G.run_list_level == 1 && G_interactive_fd) {
8582 /* Waits for completion, then fg's main shell */
8583 rcode = checkjobs_and_fg_shell(pi);
8584 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8588 /* This one just waits for completion */
8589 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8590 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8592 G.last_exitcode = rcode;
8593 check_and_run_traps();
8596 /* Handle "set -e" */
8597 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8598 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8599 if (G.errexit_depth == 0)
8602 G.errexit_depth = sv_errexit_depth;
8604 /* Analyze how result affects subsequent commands */
8606 if (rword == RES_IF || rword == RES_ELIF)
8609 check_jobs_and_continue:
8610 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8611 dont_check_jobs_but_continue: ;
8612 #if ENABLE_HUSH_LOOPS
8613 /* Beware of "while false; true; do ..."! */
8615 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8616 /* check for RES_DONE is needed for "while ...; do \n done" case */
8618 if (rword == RES_WHILE) {
8620 /* "while false; do...done" - exitcode 0 */
8621 G.last_exitcode = rcode = EXIT_SUCCESS;
8622 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8626 if (rword == RES_UNTIL) {
8628 debug_printf_exec(": until expr is true: breaking\n");
8639 #if ENABLE_HUSH_LOOPS
8644 #if ENABLE_HUSH_CASE
8648 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8652 /* Select which version we will use */
8653 static int run_and_free_list(struct pipe *pi)
8656 debug_printf_exec("run_and_free_list entered\n");
8657 if (!G.o_opt[OPT_O_NOEXEC]) {
8658 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8659 rcode = run_list(pi);
8661 /* free_pipe_list has the side effect of clearing memory.
8662 * In the long run that function can be merged with run_list,
8663 * but doing that now would hobble the debugging effort. */
8665 debug_printf_exec("run_and_free_list return %d\n", rcode);
8670 static void install_sighandlers(unsigned mask)
8672 sighandler_t old_handler;
8674 while ((mask >>= 1) != 0) {
8678 old_handler = install_sighandler(sig, pick_sighandler(sig));
8679 /* POSIX allows shell to re-enable SIGCHLD
8680 * even if it was SIG_IGN on entry.
8681 * Therefore we skip IGN check for it:
8685 /* bash re-enables SIGHUP which is SIG_IGNed on entry.
8686 * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
8688 //if (sig == SIGHUP) continue; - TODO?
8689 if (old_handler == SIG_IGN) {
8690 /* oops... restore back to IGN, and record this fact */
8691 install_sighandler(sig, old_handler);
8692 #if ENABLE_HUSH_TRAP
8694 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8696 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8702 /* Called a few times only (or even once if "sh -c") */
8703 static void install_special_sighandlers(void)
8707 /* Which signals are shell-special? */
8708 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8709 if (G_interactive_fd) {
8710 mask |= SPECIAL_INTERACTIVE_SIGS;
8711 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8712 mask |= SPECIAL_JOBSTOP_SIGS;
8714 /* Careful, do not re-install handlers we already installed */
8715 if (G.special_sig_mask != mask) {
8716 unsigned diff = mask & ~G.special_sig_mask;
8717 G.special_sig_mask = mask;
8718 install_sighandlers(diff);
8724 /* Set handlers to restore tty pgrp and exit */
8725 static void install_fatal_sighandlers(void)
8729 /* We will restore tty pgrp on these signals */
8731 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8732 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8733 + (1 << SIGBUS ) * HUSH_DEBUG
8734 + (1 << SIGSEGV) * HUSH_DEBUG
8735 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8737 /* bash 3.2 seems to handle these just like 'fatal' ones */
8740 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8741 * if we aren't interactive... but in this case
8742 * we never want to restore pgrp on exit, and this fn is not called
8744 /*+ (1 << SIGHUP )*/
8745 /*+ (1 << SIGTERM)*/
8746 /*+ (1 << SIGINT )*/
8748 G_fatal_sig_mask = mask;
8750 install_sighandlers(mask);
8754 static int set_mode(int state, char mode, const char *o_opt)
8759 G.o_opt[OPT_O_NOEXEC] = state;
8762 IF_HUSH_MODE_X(G_x_mode = state;)
8766 /* "set -+o" without parameter.
8767 * in bash, set -o produces this output:
8771 * We always use the second form.
8773 const char *p = o_opt_strings;
8776 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8782 idx = index_in_strings(o_opt_strings, o_opt);
8784 G.o_opt[idx] = state;
8788 G.o_opt[OPT_O_ERREXIT] = state;
8791 return EXIT_FAILURE;
8793 return EXIT_SUCCESS;
8796 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8797 int hush_main(int argc, char **argv)
8800 OPT_login = (1 << 0),
8804 unsigned builtin_argc;
8806 struct variable *cur_var;
8807 struct variable *shell_ver;
8810 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8811 G.last_exitcode = EXIT_SUCCESS;
8813 #if ENABLE_HUSH_FAST
8814 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8817 G.argv0_for_re_execing = argv[0];
8819 /* Deal with HUSH_VERSION */
8820 shell_ver = xzalloc(sizeof(*shell_ver));
8821 shell_ver->flg_export = 1;
8822 shell_ver->flg_read_only = 1;
8823 /* Code which handles ${var<op>...} needs writable values for all variables,
8824 * therefore we xstrdup: */
8825 shell_ver->varstr = xstrdup(hush_version_str);
8826 /* Create shell local variables from the values
8827 * currently living in the environment */
8828 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8829 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8830 G.top_var = shell_ver;
8831 cur_var = G.top_var;
8834 char *value = strchr(*e, '=');
8835 if (value) { /* paranoia */
8836 cur_var->next = xzalloc(sizeof(*cur_var));
8837 cur_var = cur_var->next;
8838 cur_var->varstr = *e;
8839 cur_var->max_len = strlen(*e);
8840 cur_var->flg_export = 1;
8844 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8845 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8846 putenv(shell_ver->varstr);
8849 set_pwd_var(SETFLAG_EXPORT);
8851 #if BASH_HOSTNAME_VAR
8852 /* Set (but not export) HOSTNAME unless already set */
8853 if (!get_local_var_value("HOSTNAME")) {
8856 set_local_var_from_halves("HOSTNAME", uts.nodename);
8858 /* bash also exports SHLVL and _,
8859 * and sets (but doesn't export) the following variables:
8861 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8862 * BASH_VERSION='3.2.0(1)-release'
8864 * MACHTYPE=i386-pc-linux-gnu
8866 * PPID=<NNNNN> - we also do it elsewhere
8877 * PIPESTATUS=([0]="0")
8878 * HISTFILE=/<xxx>/.bash_history
8882 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8884 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8895 #if ENABLE_FEATURE_EDITING
8896 G.line_input_state = new_line_input_t(FOR_SHELL);
8899 /* Initialize some more globals to non-zero values */
8900 cmdedit_update_prompt();
8902 die_func = restore_ttypgrp_and__exit;
8904 /* Shell is non-interactive at first. We need to call
8905 * install_special_sighandlers() if we are going to execute "sh <script>",
8906 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8907 * If we later decide that we are interactive, we run install_special_sighandlers()
8908 * in order to intercept (more) signals.
8912 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8913 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8916 opt = getopt(argc, argv, "+c:exinsl"
8919 # if ENABLE_HUSH_FUNCTIONS
8929 * sh ... -c 'script'
8930 * sh ... -c 'script' ARG0 [ARG1...]
8931 * On NOMMU, if builtin_argc != 0,
8932 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8933 * "" needs to be replaced with NULL
8934 * and BARGV vector fed to builtin function.
8935 * Note: the form without ARG0 never happens:
8936 * sh ... -c 'builtin' BARGV... ""
8939 G.root_pid = getpid();
8940 G.root_ppid = getppid();
8942 G.global_argv = argv + optind;
8943 G.global_argc = argc - optind;
8945 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8946 const struct built_in_command *x;
8948 install_special_sighandlers();
8949 x = find_builtin(optarg);
8950 if (x) { /* paranoia */
8951 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8952 G.global_argv += builtin_argc;
8953 G.global_argv[-1] = NULL; /* replace "" */
8955 G.last_exitcode = x->b_function(argv + optind - 1);
8959 if (!G.global_argv[0]) {
8960 /* -c 'script' (no params): prevent empty $0 */
8961 G.global_argv--; /* points to argv[i] of 'script' */
8962 G.global_argv[0] = argv[0];
8964 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8965 install_special_sighandlers();
8966 parse_and_run_string(optarg);
8969 /* Well, we cannot just declare interactiveness,
8970 * we have to have some stuff (ctty, etc) */
8971 /* G_interactive_fd++; */
8974 /* "-s" means "read from stdin", but this is how we always
8975 * operate, so simply do nothing here. */
8981 case '<': /* "big heredoc" support */
8982 full_write1_str(optarg);
8985 unsigned long long empty_trap_mask;
8987 G.root_pid = bb_strtou(optarg, &optarg, 16);
8989 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8991 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8993 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8995 builtin_argc = bb_strtou(optarg, &optarg, 16);
8997 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8998 if (empty_trap_mask != 0) {
8999 IF_HUSH_TRAP(int sig;)
9000 install_special_sighandlers();
9001 # if ENABLE_HUSH_TRAP
9002 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9003 for (sig = 1; sig < NSIG; sig++) {
9004 if (empty_trap_mask & (1LL << sig)) {
9005 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
9006 install_sighandler(sig, SIG_IGN);
9011 # if ENABLE_HUSH_LOOPS
9013 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
9019 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
9021 # if ENABLE_HUSH_FUNCTIONS
9023 struct function *funcp = new_function(optarg);
9024 /* funcp->name is already set to optarg */
9025 /* funcp->body is set to NULL. It's a special case. */
9026 funcp->body_as_string = argv[optind];
9035 if (set_mode(1, opt, NULL) == 0) /* no error */
9039 fprintf(stderr, "Usage: sh [FILE]...\n"
9040 " or: sh -c command [args]...\n\n");
9046 } /* option parsing loop */
9048 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9049 G.global_argc = argc - (optind - 1);
9050 G.global_argv = argv + (optind - 1);
9051 G.global_argv[0] = argv[0];
9054 G.root_pid = getpid();
9055 G.root_ppid = getppid();
9058 /* If we are login shell... */
9059 if (flags & OPT_login) {
9061 debug_printf("sourcing /etc/profile\n");
9062 input = fopen_for_read("/etc/profile");
9063 if (input != NULL) {
9064 remember_FILE(input);
9065 install_special_sighandlers();
9066 parse_and_run_file(input);
9067 fclose_and_forget(input);
9069 /* bash: after sourcing /etc/profile,
9070 * tries to source (in the given order):
9071 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9072 * stopping on first found. --noprofile turns this off.
9073 * bash also sources ~/.bash_logout on exit.
9074 * If called as sh, skips .bash_XXX files.
9078 if (G.global_argv[1]) {
9081 * "bash <script>" (which is never interactive (unless -i?))
9082 * sources $BASH_ENV here (without scanning $PATH).
9083 * If called as sh, does the same but with $ENV.
9084 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9088 debug_printf("running script '%s'\n", G.global_argv[0]);
9089 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9090 input = xfopen_for_read(G.global_argv[0]);
9091 xfunc_error_retval = 1;
9092 remember_FILE(input);
9093 install_special_sighandlers();
9094 parse_and_run_file(input);
9095 #if ENABLE_FEATURE_CLEAN_UP
9096 fclose_and_forget(input);
9101 /* Up to here, shell was non-interactive. Now it may become one.
9102 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9105 /* A shell is interactive if the '-i' flag was given,
9106 * or if all of the following conditions are met:
9108 * no arguments remaining or the -s flag given
9109 * standard input is a terminal
9110 * standard output is a terminal
9111 * Refer to Posix.2, the description of the 'sh' utility.
9114 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9115 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9116 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9117 if (G_saved_tty_pgrp < 0)
9118 G_saved_tty_pgrp = 0;
9120 /* try to dup stdin to high fd#, >= 255 */
9121 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9122 if (G_interactive_fd < 0) {
9123 /* try to dup to any fd */
9124 G_interactive_fd = dup(STDIN_FILENO);
9125 if (G_interactive_fd < 0) {
9127 G_interactive_fd = 0;
9128 G_saved_tty_pgrp = 0;
9131 // TODO: track & disallow any attempts of user
9132 // to (inadvertently) close/redirect G_interactive_fd
9134 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9135 if (G_interactive_fd) {
9136 close_on_exec_on(G_interactive_fd);
9138 if (G_saved_tty_pgrp) {
9139 /* If we were run as 'hush &', sleep until we are
9140 * in the foreground (tty pgrp == our pgrp).
9141 * If we get started under a job aware app (like bash),
9142 * make sure we are now in charge so we don't fight over
9143 * who gets the foreground */
9145 pid_t shell_pgrp = getpgrp();
9146 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9147 if (G_saved_tty_pgrp == shell_pgrp)
9149 /* send TTIN to ourself (should stop us) */
9150 kill(- shell_pgrp, SIGTTIN);
9154 /* Install more signal handlers */
9155 install_special_sighandlers();
9157 if (G_saved_tty_pgrp) {
9158 /* Set other signals to restore saved_tty_pgrp */
9159 install_fatal_sighandlers();
9160 /* Put ourselves in our own process group
9161 * (bash, too, does this only if ctty is available) */
9162 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9163 /* Grab control of the terminal */
9164 tcsetpgrp(G_interactive_fd, getpid());
9166 enable_restore_tty_pgrp_on_exit();
9168 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9170 const char *hp = get_local_var_value("HISTFILE");
9172 hp = get_local_var_value("HOME");
9174 hp = concat_path_file(hp, ".hush_history");
9179 G.line_input_state->hist_file = hp;
9180 //set_local_var(xasprintf("HISTFILE=%s", ...));
9182 # if ENABLE_FEATURE_SH_HISTFILESIZE
9183 hp = get_local_var_value("HISTFILESIZE");
9184 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9189 install_special_sighandlers();
9191 #elif ENABLE_HUSH_INTERACTIVE
9192 /* No job control compiled in, only prompt/line editing */
9193 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9194 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9195 if (G_interactive_fd < 0) {
9196 /* try to dup to any fd */
9197 G_interactive_fd = dup(STDIN_FILENO);
9198 if (G_interactive_fd < 0)
9200 G_interactive_fd = 0;
9203 if (G_interactive_fd) {
9204 close_on_exec_on(G_interactive_fd);
9206 install_special_sighandlers();
9208 /* We have interactiveness code disabled */
9209 install_special_sighandlers();
9212 * if interactive but not a login shell, sources ~/.bashrc
9213 * (--norc turns this off, --rcfile <file> overrides)
9216 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9217 /* note: ash and hush share this string */
9218 printf("\n\n%s %s\n"
9219 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9222 "hush - the humble shell"
9226 parse_and_run_file(stdin);
9229 hush_exit(G.last_exitcode);
9236 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9241 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9242 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9244 int argc = string_array_len(argv);
9245 return applet_main_func(argc, argv);
9248 #if ENABLE_HUSH_TEST || BASH_TEST2
9249 static int FAST_FUNC builtin_test(char **argv)
9251 return run_applet_main(argv, test_main);
9254 #if ENABLE_HUSH_ECHO
9255 static int FAST_FUNC builtin_echo(char **argv)
9257 return run_applet_main(argv, echo_main);
9260 #if ENABLE_HUSH_PRINTF
9261 static int FAST_FUNC builtin_printf(char **argv)
9263 return run_applet_main(argv, printf_main);
9267 #if ENABLE_HUSH_HELP
9268 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9270 const struct built_in_command *x;
9273 "Built-in commands:\n"
9274 "------------------\n");
9275 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9277 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9279 return EXIT_SUCCESS;
9283 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9284 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9286 show_history(G.line_input_state);
9287 return EXIT_SUCCESS;
9291 static char **skip_dash_dash(char **argv)
9294 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9299 static int FAST_FUNC builtin_cd(char **argv)
9303 argv = skip_dash_dash(argv);
9305 if (newdir == NULL) {
9306 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9307 * bash says "bash: cd: HOME not set" and does nothing
9310 const char *home = get_local_var_value("HOME");
9311 newdir = home ? home : "/";
9313 if (chdir(newdir)) {
9314 /* Mimic bash message exactly */
9315 bb_perror_msg("cd: %s", newdir);
9316 return EXIT_FAILURE;
9318 /* Read current dir (get_cwd(1) is inside) and set PWD.
9319 * Note: do not enforce exporting. If PWD was unset or unexported,
9320 * set it again, but do not export. bash does the same.
9322 set_pwd_var(/*flag:*/ 0);
9323 return EXIT_SUCCESS;
9326 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9329 return EXIT_SUCCESS;
9332 static int FAST_FUNC builtin_eval(char **argv)
9334 int rcode = EXIT_SUCCESS;
9336 argv = skip_dash_dash(argv);
9338 char *str = expand_strvec_to_string(argv);
9340 * eval "echo Hi; done" ("done" is syntax error):
9341 * "echo Hi" will not execute too.
9343 parse_and_run_string(str);
9345 rcode = G.last_exitcode;
9350 static int FAST_FUNC builtin_exec(char **argv)
9352 argv = skip_dash_dash(argv);
9353 if (argv[0] == NULL)
9354 return EXIT_SUCCESS; /* bash does this */
9356 /* Careful: we can end up here after [v]fork. Do not restore
9357 * tty pgrp then, only top-level shell process does that */
9358 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9359 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9361 /* Saved-redirect fds, script fds and G_interactive_fd are still
9362 * open here. However, they are all CLOEXEC, and execv below
9363 * closes them. Try interactive "exec ls -l /proc/self/fd",
9364 * it should show no extra open fds in the "ls" process.
9365 * If we'd try to run builtins/NOEXECs, this would need improving.
9367 //close_saved_fds_and_FILE_fds();
9369 /* TODO: if exec fails, bash does NOT exit! We do.
9370 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9371 * and tcsetpgrp, and this is inherently racy.
9373 execvp_or_die(argv);
9376 static int FAST_FUNC builtin_exit(char **argv)
9378 debug_printf_exec("%s()\n", __func__);
9380 /* interactive bash:
9381 * # trap "echo EEE" EXIT
9384 * There are stopped jobs.
9385 * (if there are _stopped_ jobs, running ones don't count)
9388 * EEE (then bash exits)
9390 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9393 /* note: EXIT trap is run by hush_exit */
9394 argv = skip_dash_dash(argv);
9395 if (argv[0] == NULL)
9396 hush_exit(G.last_exitcode);
9397 /* mimic bash: exit 123abc == exit 255 + error msg */
9398 xfunc_error_retval = 255;
9399 /* bash: exit -2 == exit 254, no error msg */
9400 hush_exit(xatoi(argv[0]) & 0xff);
9403 #if ENABLE_HUSH_TYPE
9404 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9405 static int FAST_FUNC builtin_type(char **argv)
9407 int ret = EXIT_SUCCESS;
9413 if (0) {} /* make conditional compile easier below */
9414 /*else if (find_alias(*argv))
9415 type = "an alias";*/
9416 #if ENABLE_HUSH_FUNCTIONS
9417 else if (find_function(*argv))
9418 type = "a function";
9420 else if (find_builtin(*argv))
9421 type = "a shell builtin";
9422 else if ((path = find_in_path(*argv)) != NULL)
9425 bb_error_msg("type: %s: not found", *argv);
9430 printf("%s is %s\n", *argv, type);
9438 #if ENABLE_HUSH_READ
9439 /* Interruptibility of read builtin in bash
9440 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9442 * Empty trap makes read ignore corresponding signal, for any signal.
9445 * - terminates non-interactive shell;
9446 * - interrupts read in interactive shell;
9447 * if it has non-empty trap:
9448 * - executes trap and returns to command prompt in interactive shell;
9449 * - executes trap and returns to read in non-interactive shell;
9451 * - is ignored (does not interrupt) read in interactive shell;
9452 * - terminates non-interactive shell;
9453 * if it has non-empty trap:
9454 * - executes trap and returns to read;
9456 * - terminates shell (regardless of interactivity);
9457 * if it has non-empty trap:
9458 * - executes trap and returns to read;
9459 * SIGCHLD from children:
9460 * - does not interrupt read regardless of interactivity:
9461 * try: sleep 1 & read x; echo $x
9463 static int FAST_FUNC builtin_read(char **argv)
9470 char *opt_d = NULL; /* optimized out if !BASH */
9474 /* "!": do not abort on errors.
9475 * Option string must start with "sr" to match BUILTIN_READ_xxx
9477 read_flags = getopt32(argv,
9479 "!srn:p:t:u:d:", &opt_n, &opt_p, &opt_t, &opt_u, &opt_d
9481 "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u
9484 if (read_flags == (uint32_t)-1)
9485 return EXIT_FAILURE;
9487 ifs = get_local_var_value("IFS"); /* can be NULL */
9490 r = shell_builtin_read(set_local_var_from_halves,
9501 if ((uintptr_t)r == 1 && errno == EINTR) {
9502 unsigned sig = check_and_run_traps();
9507 if ((uintptr_t)r > 1) {
9508 bb_error_msg("%s", r);
9509 r = (char*)(uintptr_t)1;
9512 return (uintptr_t)r;
9516 #if ENABLE_HUSH_UMASK
9517 static int FAST_FUNC builtin_umask(char **argv)
9524 argv = skip_dash_dash(argv);
9526 mode_t old_mask = mask;
9528 /* numeric umasks are taken as-is */
9529 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9530 if (!isdigit(argv[0][0]))
9532 mask = bb_parse_mode(argv[0], mask);
9533 if (!isdigit(argv[0][0]))
9535 if ((unsigned)mask > 0777) {
9538 * bash: umask: 'q': invalid symbolic mode operator
9539 * bash: umask: 999: octal number out of range
9541 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9546 printf("%04o\n", (unsigned) mask);
9547 /* fall through and restore mask which we set to 0 */
9551 return !rc; /* rc != 0 - success */
9555 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9556 static void print_escaped(const char *s)
9561 const char *p = strchrnul(s, '\'');
9562 /* print 'xxxx', possibly just '' */
9563 printf("'%.*s'", (int)(p - s), s);
9568 /* s points to '; print "'''...'''" */
9570 do putchar('\''); while (*++s == '\'');
9576 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9577 static int helper_export_local(char **argv, unsigned flags)
9581 char *name_end = strchrnul(name, '=');
9583 /* So far we do not check that name is valid (TODO?) */
9585 if (*name_end == '\0') {
9586 struct variable *var, **vpp;
9588 vpp = get_ptr_to_local_var(name, name_end - name);
9589 var = vpp ? *vpp : NULL;
9591 if (flags & SETFLAG_UNEXPORT) {
9592 /* export -n NAME (without =VALUE) */
9594 var->flg_export = 0;
9595 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9597 } /* else: export -n NOT_EXISTING_VAR: no-op */
9600 if (flags & SETFLAG_EXPORT) {
9601 /* export NAME (without =VALUE) */
9603 var->flg_export = 1;
9604 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9605 putenv(var->varstr);
9609 if (flags & SETFLAG_MAKE_RO) {
9610 /* readonly NAME (without =VALUE) */
9612 var->flg_read_only = 1;
9616 # if ENABLE_HUSH_LOCAL
9617 /* Is this "local" bltin? */
9618 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9619 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9620 if (var && var->func_nest_level == lvl) {
9621 /* "local x=abc; ...; local x" - ignore second local decl */
9626 /* Exporting non-existing variable.
9627 * bash does not put it in environment,
9628 * but remembers that it is exported,
9629 * and does put it in env when it is set later.
9630 * We just set it to "" and export.
9632 /* Or, it's "local NAME" (without =VALUE).
9633 * bash sets the value to "".
9635 /* Or, it's "readonly NAME" (without =VALUE).
9636 * bash remembers NAME and disallows its creation
9639 name = xasprintf("%s=", name);
9641 /* (Un)exporting/making local NAME=VALUE */
9642 name = xstrdup(name);
9644 if (set_local_var(name, flags))
9645 return EXIT_FAILURE;
9647 return EXIT_SUCCESS;
9651 #if ENABLE_HUSH_EXPORT
9652 static int FAST_FUNC builtin_export(char **argv)
9654 unsigned opt_unexport;
9656 #if ENABLE_HUSH_EXPORT_N
9657 /* "!": do not abort on errors */
9658 opt_unexport = getopt32(argv, "!n");
9659 if (opt_unexport == (uint32_t)-1)
9660 return EXIT_FAILURE;
9667 if (argv[0] == NULL) {
9674 /* ash emits: export VAR='VAL'
9675 * bash: declare -x VAR="VAL"
9676 * we follow ash example */
9677 const char *s = *e++;
9678 const char *p = strchr(s, '=');
9680 if (!p) /* wtf? take next variable */
9683 printf("export %.*s", (int)(p - s) + 1, s);
9684 print_escaped(p + 1);
9688 /*fflush_all(); - done after each builtin anyway */
9690 return EXIT_SUCCESS;
9693 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9697 #if ENABLE_HUSH_LOCAL
9698 static int FAST_FUNC builtin_local(char **argv)
9700 if (G.func_nest_level == 0) {
9701 bb_error_msg("%s: not in a function", argv[0]);
9702 return EXIT_FAILURE; /* bash compat */
9705 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9709 #if ENABLE_HUSH_READONLY
9710 static int FAST_FUNC builtin_readonly(char **argv)
9713 if (*argv == NULL) {
9714 /* bash: readonly [-p]: list all readonly VARs
9715 * (-p has no effect in bash)
9718 for (e = G.top_var; e; e = e->next) {
9719 if (e->flg_read_only) {
9720 //TODO: quote value: readonly VAR='VAL'
9721 printf("readonly %s\n", e->varstr);
9724 return EXIT_SUCCESS;
9726 return helper_export_local(argv, SETFLAG_MAKE_RO);
9730 #if ENABLE_HUSH_UNSET
9731 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9732 static int FAST_FUNC builtin_unset(char **argv)
9737 /* "!": do not abort on errors */
9738 /* "+": stop at 1st non-option */
9739 opts = getopt32(argv, "!+vf");
9740 if (opts == (unsigned)-1)
9741 return EXIT_FAILURE;
9743 bb_error_msg("unset: -v and -f are exclusive");
9744 return EXIT_FAILURE;
9750 if (!(opts & 2)) { /* not -f */
9751 if (unset_local_var(*argv)) {
9752 /* unset <nonexistent_var> doesn't fail.
9753 * Error is when one tries to unset RO var.
9754 * Message was printed by unset_local_var. */
9758 # if ENABLE_HUSH_FUNCTIONS
9770 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9771 * built-in 'set' handler
9773 * set [-abCefhmnuvx] [-o option] [argument...]
9774 * set [+abCefhmnuvx] [+o option] [argument...]
9775 * set -- [argument...]
9778 * Implementations shall support the options in both their hyphen and
9779 * plus-sign forms. These options can also be specified as options to sh.
9781 * Write out all variables and their values: set
9782 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9783 * Turn on the -x and -v options: set -xv
9784 * Unset all positional parameters: set --
9785 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9786 * Set the positional parameters to the expansion of x, even if x expands
9787 * with a leading '-' or '+': set -- $x
9789 * So far, we only support "set -- [argument...]" and some of the short names.
9791 static int FAST_FUNC builtin_set(char **argv)
9794 char **pp, **g_argv;
9795 char *arg = *++argv;
9799 for (e = G.top_var; e; e = e->next)
9801 return EXIT_SUCCESS;
9805 if (strcmp(arg, "--") == 0) {
9809 if (arg[0] != '+' && arg[0] != '-')
9811 for (n = 1; arg[n]; ++n) {
9812 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9814 if (arg[n] == 'o' && argv[1])
9817 } while ((arg = *++argv) != NULL);
9818 /* Now argv[0] is 1st argument */
9821 return EXIT_SUCCESS;
9824 /* NB: G.global_argv[0] ($0) is never freed/changed */
9825 g_argv = G.global_argv;
9826 if (G.global_args_malloced) {
9832 G.global_args_malloced = 1;
9833 pp = xzalloc(sizeof(pp[0]) * 2);
9834 pp[0] = g_argv[0]; /* retain $0 */
9837 /* This realloc's G.global_argv */
9838 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9840 G.global_argc = 1 + string_array_len(pp + 1);
9842 return EXIT_SUCCESS;
9844 /* Nothing known, so abort */
9846 bb_error_msg("set: %s: invalid option", arg);
9847 return EXIT_FAILURE;
9851 static int FAST_FUNC builtin_shift(char **argv)
9854 argv = skip_dash_dash(argv);
9856 n = bb_strtou(argv[0], NULL, 10);
9857 if (errno || n < 0) {
9858 /* shared string with ash.c */
9859 bb_error_msg("Illegal number: %s", argv[0]);
9861 * ash aborts in this case.
9862 * bash prints error message and set $? to 1.
9863 * Interestingly, for "shift 99999" bash does not
9864 * print error message, but does set $? to 1
9865 * (and does no shifting at all).
9869 if (n >= 0 && n < G.global_argc) {
9870 if (G_global_args_malloced) {
9873 free(G.global_argv[m++]);
9876 memmove(&G.global_argv[1], &G.global_argv[n+1],
9877 G.global_argc * sizeof(G.global_argv[0]));
9878 return EXIT_SUCCESS;
9880 return EXIT_FAILURE;
9883 #if ENABLE_HUSH_GETOPTS
9884 static int FAST_FUNC builtin_getopts(char **argv)
9886 /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
9889 If a required argument is not found, and getopts is not silent,
9890 a question mark (?) is placed in VAR, OPTARG is unset, and a
9891 diagnostic message is printed. If getopts is silent, then a
9892 colon (:) is placed in VAR and OPTARG is set to the option
9895 Test that VAR is a valid variable name?
9897 "Whenever the shell is invoked, OPTIND shall be initialized to 1"
9900 const char *cp, *optstring, *var;
9901 int c, n, exitcode, my_opterr;
9904 optstring = *++argv;
9905 if (!optstring || !(var = *++argv)) {
9906 bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
9907 return EXIT_FAILURE;
9911 argv[0] = G.global_argv[0]; /* for error messages in getopt() */
9913 argv = G.global_argv;
9917 if (optstring[0] != ':') {
9918 cp = get_local_var_value("OPTERR");
9919 /* 0 if "OPTERR=0", 1 otherwise */
9920 my_opterr = (!cp || NOT_LONE_CHAR(cp, '0'));
9923 /* getopts stops on first non-option. Add "+" to force that */
9924 /*if (optstring[0] != '+')*/ {
9925 char *s = alloca(strlen(optstring) + 2);
9926 sprintf(s, "+%s", optstring);
9930 /* Naively, now we should just
9931 * cp = get_local_var_value("OPTIND");
9932 * optind = cp ? atoi(cp) : 0;
9934 * opterr = my_opterr;
9935 * c = getopt(string_array_len(argv), argv, optstring);
9936 * and be done? Not so fast...
9937 * Unlike normal getopt() usage in C programs, here
9938 * each successive call will (usually) have the same argv[] CONTENTS,
9939 * but not the ADDRESSES. Worse yet, it's possible that between
9940 * invocations of "getopts", there will be calls to shell builtins
9941 * which use getopt() internally. Example:
9942 * while getopts "abc" RES -a -bc -abc de; do
9945 * This would not work correctly: getopt() call inside "unset"
9946 * modifies internal libc state which is tracking position in
9947 * multi-option strings ("-abc"). At best, it can skip options
9948 * or return the same option infinitely. With glibc implementation
9949 * of getopt(), it would use outright invalid pointers and return
9950 * garbage even _without_ "unset" mangling internal state.
9952 * We resort to resetting getopt() state and calling it N times,
9953 * until we get Nth result (or failure).
9954 * (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set).
9958 n = string_array_len(argv);
9961 opterr = (count < G.getopt_count) ? 0 : my_opterr;
9962 c = getopt(n, argv, optstring);
9966 } while (count <= G.getopt_count);
9968 /* Set OPTIND. Prevent resetting of the magic counter! */
9969 set_local_var_from_halves("OPTIND", utoa(optind));
9970 G.getopt_count = count; /* "next time, give me N+1'th result" */
9971 GETOPT_RESET(); /* just in case */
9974 /* Always set or unset, never left as-is, even on exit/error:
9975 * "If no option was found, or if the option that was found
9976 * does not have an option-argument, OPTARG shall be unset."
9980 /* If ":optstring" and unknown option is seen,
9981 * it is stored to OPTARG.
9983 if (optstring[1] == ':') {
9989 set_local_var_from_halves("OPTARG", cp);
9991 unset_local_var("OPTARG");
9993 /* Convert -1 to "?" */
9994 exitcode = EXIT_SUCCESS;
9995 if (c < 0) { /* -1: end of options */
9996 exitcode = EXIT_FAILURE;
10002 set_local_var_from_halves(var, cbuf);
10008 static int FAST_FUNC builtin_source(char **argv)
10010 char *arg_path, *filename;
10013 char *args_need_save;
10014 #if ENABLE_HUSH_FUNCTIONS
10018 argv = skip_dash_dash(argv);
10019 filename = argv[0];
10021 /* bash says: "bash: .: filename argument required" */
10022 return 2; /* bash compat */
10025 if (!strchr(filename, '/')) {
10026 arg_path = find_in_path(filename);
10028 filename = arg_path;
10030 input = remember_FILE(fopen_or_warn(filename, "r"));
10033 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
10034 /* POSIX: non-interactive shell should abort here,
10035 * not merely fail. So far no one complained :)
10037 return EXIT_FAILURE;
10040 #if ENABLE_HUSH_FUNCTIONS
10041 sv_flg = G_flag_return_in_progress;
10042 /* "we are inside sourced file, ok to use return" */
10043 G_flag_return_in_progress = -1;
10045 args_need_save = argv[1]; /* used as a boolean variable */
10046 if (args_need_save)
10047 save_and_replace_G_args(&sv, argv);
10049 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
10050 G.last_exitcode = 0;
10051 parse_and_run_file(input);
10052 fclose_and_forget(input);
10054 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
10055 restore_G_args(&sv, argv);
10056 #if ENABLE_HUSH_FUNCTIONS
10057 G_flag_return_in_progress = sv_flg;
10060 return G.last_exitcode;
10063 #if ENABLE_HUSH_TRAP
10064 static int FAST_FUNC builtin_trap(char **argv)
10070 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
10075 /* No args: print all trapped */
10076 for (i = 0; i < NSIG; ++i) {
10078 printf("trap -- ");
10079 print_escaped(G_traps[i]);
10080 /* note: bash adds "SIG", but only if invoked
10081 * as "bash". If called as "sh", or if set -o posix,
10082 * then it prints short signal names.
10083 * We are printing short names: */
10084 printf(" %s\n", get_signame(i));
10087 /*fflush_all(); - done after each builtin anyway */
10088 return EXIT_SUCCESS;
10092 /* If first arg is a number: reset all specified signals */
10093 sig = bb_strtou(*argv, NULL, 10);
10097 ret = EXIT_SUCCESS;
10099 sighandler_t handler;
10101 sig = get_signum(*argv++);
10103 ret = EXIT_FAILURE;
10104 /* Mimic bash message exactly */
10105 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
10109 free(G_traps[sig]);
10110 G_traps[sig] = xstrdup(new_cmd);
10112 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
10113 get_signame(sig), sig, G_traps[sig]);
10115 /* There is no signal for 0 (EXIT) */
10120 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
10122 /* We are removing trap handler */
10123 handler = pick_sighandler(sig);
10124 install_sighandler(sig, handler);
10129 if (!argv[1]) { /* no second arg */
10130 bb_error_msg("trap: invalid arguments");
10131 return EXIT_FAILURE;
10134 /* First arg is "-": reset all specified to default */
10135 /* First arg is "--": skip it, the rest is "handler SIGs..." */
10136 /* Everything else: set arg as signal handler
10137 * (includes "" case, which ignores signal) */
10138 if (argv[0][0] == '-') {
10139 if (argv[0][1] == '\0') { /* "-" */
10140 /* new_cmd remains NULL: "reset these sigs" */
10143 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
10146 /* else: "-something", no special meaning */
10151 goto process_sig_list;
10155 #if ENABLE_HUSH_JOB
10156 static struct pipe *parse_jobspec(const char *str)
10161 if (sscanf(str, "%%%u", &jobnum) != 1) {
10163 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
10165 bb_error_msg("bad argument '%s'", str);
10168 /* It is "%%", "%+" or "%" - current job */
10169 jobnum = G.last_jobid;
10171 bb_error_msg("no current job");
10175 for (pi = G.job_list; pi; pi = pi->next) {
10176 if (pi->jobid == jobnum) {
10180 bb_error_msg("%u: no such job", jobnum);
10184 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10187 const char *status_string;
10189 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10190 for (job = G.job_list; job; job = job->next) {
10191 if (job->alive_cmds == job->stopped_cmds)
10192 status_string = "Stopped";
10194 status_string = "Running";
10196 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10199 clean_up_last_dead_job();
10201 return EXIT_SUCCESS;
10204 /* built-in 'fg' and 'bg' handler */
10205 static int FAST_FUNC builtin_fg_bg(char **argv)
10210 if (!G_interactive_fd)
10211 return EXIT_FAILURE;
10213 /* If they gave us no args, assume they want the last backgrounded task */
10215 for (pi = G.job_list; pi; pi = pi->next) {
10216 if (pi->jobid == G.last_jobid) {
10220 bb_error_msg("%s: no current job", argv[0]);
10221 return EXIT_FAILURE;
10224 pi = parse_jobspec(argv[1]);
10226 return EXIT_FAILURE;
10228 /* TODO: bash prints a string representation
10229 * of job being foregrounded (like "sleep 1 | cat") */
10230 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10231 /* Put the job into the foreground. */
10232 tcsetpgrp(G_interactive_fd, pi->pgrp);
10235 /* Restart the processes in the job */
10236 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10237 for (i = 0; i < pi->num_cmds; i++) {
10238 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10240 pi->stopped_cmds = 0;
10242 i = kill(- pi->pgrp, SIGCONT);
10244 if (errno == ESRCH) {
10245 delete_finished_job(pi);
10246 return EXIT_SUCCESS;
10248 bb_perror_msg("kill (SIGCONT)");
10251 if (argv[0][0] == 'f') {
10252 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10253 return checkjobs_and_fg_shell(pi);
10255 return EXIT_SUCCESS;
10259 #if ENABLE_HUSH_KILL
10260 static int FAST_FUNC builtin_kill(char **argv)
10264 # if ENABLE_HUSH_JOB
10265 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10273 if (argv[i][0] != '%')
10276 * "kill %N" - job kill
10277 * Converting to pgrp / pid kill
10279 pi = parse_jobspec(argv[i]);
10281 /* Eat bad jobspec */
10285 argv[j - 1] = argv[j];
10292 * In jobs started under job control, we signal
10293 * entire process group by kill -PGRP_ID.
10294 * This happens, f.e., in interactive shell.
10296 * Otherwise, we signal each child via
10297 * kill PID1 PID2 PID3.
10299 * sh -c 'sleep 1|sleep 1 & kill %1'
10300 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10301 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10303 n = G_interactive_fd ? 1 : pi->num_cmds;
10304 dst = alloca(n * sizeof(int)*4);
10306 if (G_interactive_fd)
10307 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10308 else for (j = 0; j < n; j++) {
10309 struct command *cmd = &pi->cmds[j];
10310 /* Skip exited members of the job */
10314 * kill_main has matching code to expect
10315 * leading space. Needed to not confuse
10316 * negative pids with "kill -SIGNAL_NO" syntax
10318 dst += sprintf(dst, " %u", (int)cmd->pid);
10321 } while (argv[++i]);
10325 if (argv[1] || ret == 0) {
10326 ret = run_applet_main(argv, kill_main);
10328 /* else: ret = 1, "kill %bad_jobspec" case */
10333 #if ENABLE_HUSH_WAIT
10334 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10335 #if !ENABLE_HUSH_JOB
10336 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10338 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10345 if (!sigisemptyset(&G.pending_set))
10348 /* waitpid is not interruptible by SA_RESTARTed
10349 * signals which we use. Thus, this ugly dance:
10352 /* Make sure possible SIGCHLD is stored in kernel's
10353 * pending signal mask before we call waitpid.
10354 * Or else we may race with SIGCHLD, lose it,
10355 * and get stuck in sigsuspend...
10357 sigfillset(&oldset); /* block all signals, remember old set */
10358 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10360 if (!sigisemptyset(&G.pending_set)) {
10361 /* Crap! we raced with some signal! */
10365 /*errno = 0; - checkjobs does this */
10366 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10367 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10368 debug_printf_exec("checkjobs:%d\n", ret);
10369 #if ENABLE_HUSH_JOB
10370 if (waitfor_pipe) {
10371 int rcode = job_exited_or_stopped(waitfor_pipe);
10372 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10375 sigprocmask(SIG_SETMASK, &oldset, NULL);
10380 /* if ECHILD, there are no children (ret is -1 or 0) */
10381 /* if ret == 0, no children changed state */
10382 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10383 if (errno == ECHILD || ret) {
10385 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10387 sigprocmask(SIG_SETMASK, &oldset, NULL);
10390 /* Wait for SIGCHLD or any other signal */
10391 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10392 /* Note: sigsuspend invokes signal handler */
10393 sigsuspend(&oldset);
10395 sigprocmask(SIG_SETMASK, &oldset, NULL);
10397 /* So, did we get a signal? */
10398 sig = check_and_run_traps();
10399 if (sig /*&& sig != SIGCHLD - always true */) {
10400 /* Do this for any (non-ignored) signal, not only for ^C */
10404 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10409 static int FAST_FUNC builtin_wait(char **argv)
10414 argv = skip_dash_dash(argv);
10415 if (argv[0] == NULL) {
10416 /* Don't care about wait results */
10417 /* Note 1: must wait until there are no more children */
10418 /* Note 2: must be interruptible */
10420 * $ sleep 3 & sleep 6 & wait
10421 * [1] 30934 sleep 3
10422 * [2] 30935 sleep 6
10425 * $ sleep 3 & sleep 6 & wait
10426 * [1] 30936 sleep 3
10427 * [2] 30937 sleep 6
10429 * ^C <-- after ~4 sec from keyboard
10432 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10436 pid_t pid = bb_strtou(*argv, NULL, 10);
10437 if (errno || pid <= 0) {
10438 #if ENABLE_HUSH_JOB
10439 if (argv[0][0] == '%') {
10440 struct pipe *wait_pipe;
10441 ret = 127; /* bash compat for bad jobspecs */
10442 wait_pipe = parse_jobspec(*argv);
10444 ret = job_exited_or_stopped(wait_pipe);
10446 ret = wait_for_child_or_signal(wait_pipe, 0);
10448 /* waiting on "last dead job" removes it */
10449 clean_up_last_dead_job();
10452 /* else: parse_jobspec() already emitted error msg */
10456 /* mimic bash message */
10457 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10458 ret = EXIT_FAILURE;
10459 continue; /* bash checks all argv[] */
10462 /* Do we have such child? */
10463 ret = waitpid(pid, &status, WNOHANG);
10467 if (errno == ECHILD) {
10468 if (pid == G.last_bg_pid) {
10469 /* "wait $!" but last bg task has already exited. Try:
10470 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10471 * In bash it prints exitcode 0, then 3.
10472 * In dash, it is 127.
10474 ret = G.last_bg_pid_exitcode;
10476 /* Example: "wait 1". mimic bash message */
10477 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10481 bb_perror_msg("wait %s", *argv);
10483 continue; /* bash checks all argv[] */
10486 /* Yes, and it still runs */
10487 ret = wait_for_child_or_signal(NULL, pid);
10489 /* Yes, and it just exited */
10490 process_wait_result(NULL, pid, status);
10491 ret = WEXITSTATUS(status);
10492 if (WIFSIGNALED(status))
10493 ret = 128 + WTERMSIG(status);
10501 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10502 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10505 def = bb_strtou(argv[1], NULL, 10);
10506 if (errno || def < def_min || argv[2]) {
10507 bb_error_msg("%s: bad arguments", argv[0]);
10515 #if ENABLE_HUSH_LOOPS
10516 static int FAST_FUNC builtin_break(char **argv)
10519 if (G.depth_of_loop == 0) {
10520 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10521 /* if we came from builtin_continue(), need to undo "= 1" */
10522 G.flag_break_continue = 0;
10523 return EXIT_SUCCESS; /* bash compat */
10525 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10527 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10528 if (depth == UINT_MAX)
10529 G.flag_break_continue = BC_BREAK;
10530 if (G.depth_of_loop < depth)
10531 G.depth_break_continue = G.depth_of_loop;
10533 return EXIT_SUCCESS;
10536 static int FAST_FUNC builtin_continue(char **argv)
10538 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10539 return builtin_break(argv);
10543 #if ENABLE_HUSH_FUNCTIONS
10544 static int FAST_FUNC builtin_return(char **argv)
10548 if (G_flag_return_in_progress != -1) {
10549 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10550 return EXIT_FAILURE; /* bash compat */
10553 G_flag_return_in_progress = 1;
10556 * out of range: wraps around at 256, does not error out
10557 * non-numeric param:
10558 * f() { false; return qwe; }; f; echo $?
10559 * bash: return: qwe: numeric argument required <== we do this
10560 * 255 <== we also do this
10562 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10567 #if ENABLE_HUSH_TIMES
10568 static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
10570 static const uint8_t times_tbl[] ALIGN1 = {
10571 ' ', offsetof(struct tms, tms_utime),
10572 '\n', offsetof(struct tms, tms_stime),
10573 ' ', offsetof(struct tms, tms_cutime),
10574 '\n', offsetof(struct tms, tms_cstime),
10581 clk_tck = bb_clk_tck();
10586 unsigned sec, frac;
10588 t = *(clock_t *)(((char *) &buf) + p[1]);
10590 frac = t % clk_tck;
10591 printf("%um%u.%03us%c",
10592 sec / 60, sec % 60,
10593 (frac * 1000) / clk_tck,
10598 return EXIT_SUCCESS;
10602 #if ENABLE_HUSH_MEMLEAK
10603 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10608 # ifdef M_TRIM_THRESHOLD
10609 /* Optional. Reduces probability of false positives */
10612 /* Crude attempt to find where "free memory" starts,
10613 * sans fragmentation. */
10615 l = (unsigned long)p;
10618 if (l < (unsigned long)p) l = (unsigned long)p;
10624 struct mallinfo mi = mallinfo();
10625 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10626 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10630 if (!G.memleak_value)
10631 G.memleak_value = l;
10633 l -= G.memleak_value;
10640 /* Exitcode is "how many kilobytes we leaked since 1st call" */