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
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
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]);
3844 if (word->has_quoted_part
3845 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3846 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3847 /* (otherwise it's known to be not empty and is already safe) */
3849 /* exclude "$@" - it can expand to no word despite "" */
3850 char *p = word->data;
3851 while (p[0] == SPECIAL_VAR_SYMBOL
3852 && (p[1] & 0x7f) == '@'
3853 && p[2] == SPECIAL_VAR_SYMBOL
3858 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3859 debug_print_strings("word appended to argv", command->argv);
3862 #if ENABLE_HUSH_LOOPS
3863 if (ctx->ctx_res_w == RES_FOR) {
3864 if (word->has_quoted_part
3865 || !is_well_formed_var_name(command->argv[0], '\0')
3867 /* bash says just "not a valid identifier" */
3868 syntax_error("not a valid identifier in for");
3871 /* Force FOR to have just one word (variable name) */
3872 /* NB: basically, this makes hush see "for v in ..."
3873 * syntax as if it is "for v; in ...". FOR and IN become
3874 * two pipe structs in parse tree. */
3875 done_pipe(ctx, PIPE_SEQ);
3878 #if ENABLE_HUSH_CASE
3879 /* Force CASE to have just one word */
3880 if (ctx->ctx_res_w == RES_CASE) {
3881 done_pipe(ctx, PIPE_SEQ);
3885 o_reset_to_empty_unquoted(word);
3887 debug_printf_parse("done_word return 0\n");
3892 /* Peek ahead in the input to find out if we have a "&n" construct,
3893 * as in "2>&1", that represents duplicating a file descriptor.
3895 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3896 * REDIRFD_SYNTAX_ERR if syntax error,
3897 * REDIRFD_TO_FILE if no & was seen,
3898 * or the number found.
3901 #define parse_redir_right_fd(as_string, input) \
3902 parse_redir_right_fd(input)
3904 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3910 return REDIRFD_TO_FILE;
3912 ch = i_getch(input); /* get the & */
3913 nommu_addchr(as_string, ch);
3916 ch = i_getch(input);
3917 nommu_addchr(as_string, ch);
3918 return REDIRFD_CLOSE;
3922 while (ch != EOF && isdigit(ch)) {
3923 d = d*10 + (ch-'0');
3925 ch = i_getch(input);
3926 nommu_addchr(as_string, ch);
3931 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3933 bb_error_msg("ambiguous redirect");
3934 return REDIRFD_SYNTAX_ERR;
3937 /* Return code is 0 normal, 1 if a syntax error is detected
3939 static int parse_redirect(struct parse_context *ctx,
3942 struct in_str *input)
3944 struct command *command = ctx->command;
3945 struct redir_struct *redir;
3946 struct redir_struct **redirp;
3949 dup_num = REDIRFD_TO_FILE;
3950 if (style != REDIRECT_HEREDOC) {
3951 /* Check for a '>&1' type redirect */
3952 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3953 if (dup_num == REDIRFD_SYNTAX_ERR)
3956 int ch = i_peek(input);
3957 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3958 if (dup_num) { /* <<-... */
3959 ch = i_getch(input);
3960 nommu_addchr(&ctx->as_string, ch);
3965 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3966 int ch = i_peek(input);
3968 /* >|FILE redirect ("clobbering" >).
3969 * Since we do not support "set -o noclobber" yet,
3970 * >| and > are the same for now. Just eat |.
3972 ch = i_getch(input);
3973 nommu_addchr(&ctx->as_string, ch);
3977 /* Create a new redir_struct and append it to the linked list */
3978 redirp = &command->redirects;
3979 while ((redir = *redirp) != NULL) {
3980 redirp = &(redir->next);
3982 *redirp = redir = xzalloc(sizeof(*redir));
3983 /* redir->next = NULL; */
3984 /* redir->rd_filename = NULL; */
3985 redir->rd_type = style;
3986 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3988 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3989 redir_table[style].descrip);
3991 redir->rd_dup = dup_num;
3992 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3993 /* Erik had a check here that the file descriptor in question
3994 * is legit; I postpone that to "run time"
3995 * A "-" representation of "close me" shows up as a -3 here */
3996 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3997 redir->rd_fd, redir->rd_dup);
3999 #if 0 /* Instead we emit error message at run time */
4000 if (ctx->pending_redirect) {
4001 /* For example, "cmd > <file" */
4002 syntax_error("invalid redirect");
4005 /* Set ctx->pending_redirect, so we know what to do at the
4006 * end of the next parsed word. */
4007 ctx->pending_redirect = redir;
4012 /* If a redirect is immediately preceded by a number, that number is
4013 * supposed to tell which file descriptor to redirect. This routine
4014 * looks for such preceding numbers. In an ideal world this routine
4015 * needs to handle all the following classes of redirects...
4016 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4017 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4018 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4019 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4021 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4023 * ... If n is quoted, the number shall not be recognized as part of
4024 * the redirection expression. For example:
4026 * writes the character 2 into file a"
4027 * We are getting it right by setting ->has_quoted_part on any \<char>
4029 * A -1 return means no valid number was found,
4030 * the caller should use the appropriate default for this redirection.
4032 static int redirect_opt_num(o_string *o)
4036 if (o->data == NULL)
4038 num = bb_strtou(o->data, NULL, 10);
4039 if (errno || num < 0)
4041 o_reset_to_empty_unquoted(o);
4046 #define fetch_till_str(as_string, input, word, skip_tabs) \
4047 fetch_till_str(input, word, skip_tabs)
4049 static char *fetch_till_str(o_string *as_string,
4050 struct in_str *input,
4054 o_string heredoc = NULL_O_STRING;
4056 int prev = 0; /* not \ */
4062 ch = i_getch(input);
4064 nommu_addchr(as_string, ch);
4065 if (ch == '\n' || ch == EOF) {
4067 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4068 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4069 heredoc.data[past_EOL] = '\0';
4070 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4071 return heredoc.data;
4074 /* This is a new line.
4075 * Remember position and backslash-escaping status.
4077 o_addchr(&heredoc, ch);
4080 past_EOL = heredoc.length;
4081 /* Get 1st char of next line, possibly skipping leading tabs */
4083 ch = i_getch(input);
4085 nommu_addchr(as_string, ch);
4086 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4087 /* If this immediately ended the line,
4088 * go back to end-of-line checks.
4091 goto check_heredoc_end;
4096 o_free_unsafe(&heredoc);
4099 o_addchr(&heredoc, ch);
4100 nommu_addchr(as_string, ch);
4101 if (prev == '\\' && ch == '\\')
4102 /* Correctly handle foo\\<eol> (not a line cont.) */
4103 prev = 0; /* not \ */
4109 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4110 * and load them all. There should be exactly heredoc_cnt of them.
4112 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4114 struct pipe *pi = ctx->list_head;
4116 while (pi && heredoc_cnt) {
4118 struct command *cmd = pi->cmds;
4120 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4122 cmd->argv ? cmd->argv[0] : "NONE");
4123 for (i = 0; i < pi->num_cmds; i++) {
4124 struct redir_struct *redir = cmd->redirects;
4126 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4127 i, cmd->argv ? cmd->argv[0] : "NONE");
4129 if (redir->rd_type == REDIRECT_HEREDOC) {
4132 redir->rd_type = REDIRECT_HEREDOC2;
4133 /* redir->rd_dup is (ab)used to indicate <<- */
4134 p = fetch_till_str(&ctx->as_string, input,
4135 redir->rd_filename, redir->rd_dup);
4137 syntax_error("unexpected EOF in here document");
4140 free(redir->rd_filename);
4141 redir->rd_filename = p;
4144 redir = redir->next;
4151 /* Should be 0. If it isn't, it's a parse error */
4153 bb_error_msg_and_die("heredoc BUG 2");
4159 static int run_list(struct pipe *pi);
4161 #define parse_stream(pstring, input, end_trigger) \
4162 parse_stream(input, end_trigger)
4164 static struct pipe *parse_stream(char **pstring,
4165 struct in_str *input,
4169 #if !ENABLE_HUSH_FUNCTIONS
4170 #define parse_group(dest, ctx, input, ch) \
4171 parse_group(ctx, input, ch)
4173 static int parse_group(o_string *dest, struct parse_context *ctx,
4174 struct in_str *input, int ch)
4176 /* dest contains characters seen prior to ( or {.
4177 * Typically it's empty, but for function defs,
4178 * it contains function name (without '()'). */
4179 struct pipe *pipe_list;
4181 struct command *command = ctx->command;
4183 debug_printf_parse("parse_group entered\n");
4184 #if ENABLE_HUSH_FUNCTIONS
4185 if (ch == '(' && !dest->has_quoted_part) {
4187 if (done_word(dest, ctx))
4190 goto skip; /* (... */
4191 if (command->argv[1]) { /* word word ... (... */
4192 syntax_error_unexpected_ch('(');
4195 /* it is "word(..." or "word (..." */
4197 ch = i_getch(input);
4198 while (ch == ' ' || ch == '\t');
4200 syntax_error_unexpected_ch(ch);
4203 nommu_addchr(&ctx->as_string, ch);
4205 ch = i_getch(input);
4206 while (ch == ' ' || ch == '\t' || ch == '\n');
4208 syntax_error_unexpected_ch(ch);
4211 nommu_addchr(&ctx->as_string, ch);
4212 command->cmd_type = CMD_FUNCDEF;
4217 #if 0 /* Prevented by caller */
4218 if (command->argv /* word [word]{... */
4219 || dest->length /* word{... */
4220 || dest->has_quoted_part /* ""{... */
4223 debug_printf_parse("parse_group return 1: "
4224 "syntax error, groups and arglists don't mix\n");
4229 #if ENABLE_HUSH_FUNCTIONS
4235 command->cmd_type = CMD_SUBSHELL;
4237 /* bash does not allow "{echo...", requires whitespace */
4239 if (ch != ' ' && ch != '\t' && ch != '\n'
4240 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4242 syntax_error_unexpected_ch(ch);
4246 ch = i_getch(input);
4247 nommu_addchr(&ctx->as_string, ch);
4253 # define as_string NULL
4255 char *as_string = NULL;
4257 pipe_list = parse_stream(&as_string, input, endch);
4260 o_addstr(&ctx->as_string, as_string);
4262 /* empty ()/{} or parse error? */
4263 if (!pipe_list || pipe_list == ERR_PTR) {
4264 /* parse_stream already emitted error msg */
4267 debug_printf_parse("parse_group return 1: "
4268 "parse_stream returned %p\n", pipe_list);
4271 command->group = pipe_list;
4273 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4274 command->group_as_string = as_string;
4275 debug_printf_parse("end of group, remembering as:'%s'\n",
4276 command->group_as_string);
4280 debug_printf_parse("parse_group return 0\n");
4282 /* command remains "open", available for possible redirects */
4285 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4290 ch = i_getch(input);
4293 ch2 = i_peek(input);
4296 /* backslash+newline, skip it */
4301 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4309 ch2 = i_peek2(input);
4312 /* backslash+newline, skip it */
4318 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4319 /* Subroutines for copying $(...) and `...` things */
4320 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4322 static int add_till_single_quote(o_string *dest, struct in_str *input)
4325 int ch = i_getch(input);
4327 syntax_error_unterm_ch('\'');
4335 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4336 static int add_till_double_quote(o_string *dest, struct in_str *input)
4339 int ch = i_getch(input);
4341 syntax_error_unterm_ch('"');
4346 if (ch == '\\') { /* \x. Copy both chars. */
4348 ch = i_getch(input);
4352 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4357 //if (ch == '$') ...
4360 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4362 * "Within the backquoted style of command substitution, backslash
4363 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4364 * The search for the matching backquote shall be satisfied by the first
4365 * backquote found without a preceding backslash; during this search,
4366 * if a non-escaped backquote is encountered within a shell comment,
4367 * a here-document, an embedded command substitution of the $(command)
4368 * form, or a quoted string, undefined results occur. A single-quoted
4369 * or double-quoted string that begins, but does not end, within the
4370 * "`...`" sequence produces undefined results."
4372 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4374 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4377 int ch = i_getch(input);
4381 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4382 ch = i_getch(input);
4386 && (!in_dquote || ch != '"')
4388 o_addchr(dest, '\\');
4392 syntax_error_unterm_ch('`');
4398 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4399 * quoting and nested ()s.
4400 * "With the $(command) style of command substitution, all characters
4401 * following the open parenthesis to the matching closing parenthesis
4402 * constitute the command. Any valid shell script can be used for command,
4403 * except a script consisting solely of redirections which produces
4404 * unspecified results."
4406 * echo $(echo '(TEST)' BEST) (TEST) BEST
4407 * echo $(echo 'TEST)' BEST) TEST) BEST
4408 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4410 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4411 * can contain arbitrary constructs, just like $(cmd).
4412 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4413 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4415 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4416 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4419 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4420 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4421 char end_char2 = end_ch >> 8;
4423 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4426 ch = i_getch(input);
4428 syntax_error_unterm_ch(end_ch);
4432 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4438 /* we look for closing )) of $((EXPR)) */
4439 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4440 i_getch(input); /* eat second ')' */
4445 if (ch == '(' || ch == '{') {
4446 ch = (ch == '(' ? ')' : '}');
4447 if (!add_till_closing_bracket(dest, input, ch))
4453 if (!add_till_single_quote(dest, input))
4459 if (!add_till_double_quote(dest, input))
4465 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4471 /* \x. Copy verbatim. Important for \(, \) */
4472 ch = i_getch(input);
4474 syntax_error_unterm_ch(')');
4479 /* "backslash+newline", ignore both */
4480 o_delchr(dest); /* undo insertion of '\' */
4490 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4492 /* Return code: 0 for OK, 1 for syntax error */
4494 #define parse_dollar(as_string, dest, input, quote_mask) \
4495 parse_dollar(dest, input, quote_mask)
4496 #define as_string NULL
4498 static int parse_dollar(o_string *as_string,
4500 struct in_str *input, unsigned char quote_mask)
4502 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4504 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4506 ch = i_getch(input);
4507 nommu_addchr(as_string, ch);
4509 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4511 debug_printf_parse(": '%c'\n", ch);
4512 o_addchr(dest, ch | quote_mask);
4514 ch = i_peek_and_eat_bkslash_nl(input);
4515 if (!isalnum(ch) && ch != '_') {
4516 /* End of variable name reached */
4519 ch = i_getch(input);
4520 nommu_addchr(as_string, ch);
4522 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4523 } else if (isdigit(ch)) {
4525 ch = i_getch(input);
4526 nommu_addchr(as_string, ch);
4527 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4528 debug_printf_parse(": '%c'\n", ch);
4529 o_addchr(dest, ch | quote_mask);
4530 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4531 } else switch (ch) {
4533 case '!': /* last bg pid */
4534 case '?': /* last exit code */
4535 case '#': /* number of args */
4536 case '*': /* args */
4537 case '@': /* args */
4538 goto make_one_char_var;
4542 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4544 ch = i_getch(input); /* eat '{' */
4545 nommu_addchr(as_string, ch);
4547 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4548 /* It should be ${?}, or ${#var},
4549 * or even ${?+subst} - operator acting on a special variable,
4550 * or the beginning of variable name.
4553 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4556 syntax_error_unterm_str("${name}");
4557 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4560 nommu_addchr(as_string, ch);
4564 /* It's possible to just call add_till_closing_bracket() at this point.
4565 * However, this regresses some of our testsuite cases
4566 * which check invalid constructs like ${%}.
4567 * Oh well... let's check that the var name part is fine... */
4573 debug_printf_parse(": '%c'\n", ch);
4575 ch = i_getch(input);
4576 nommu_addchr(as_string, ch);
4580 if (!isalnum(ch) && ch != '_') {
4582 unsigned char last_ch;
4583 /* handle parameter expansions
4584 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4586 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4587 if (len_single_ch != '#'
4588 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4589 || i_peek(input) != '}'
4591 goto bad_dollar_syntax;
4593 /* else: it's "length of C" ${#C} op,
4594 * where C is a single char
4595 * special var name, e.g. ${#!}.
4598 /* Eat everything until closing '}' (or ':') */
4602 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4604 /* It's ${var:N[:M]} thing */
4605 end_ch = '}' * 0x100 + ':';
4607 if (BASH_PATTERN_SUBST
4610 /* It's ${var/[/]pattern[/repl]} thing */
4611 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4613 nommu_addchr(as_string, '/');
4616 end_ch = '}' * 0x100 + '/';
4622 #if ENABLE_HUSH_DOLLAR_OPS
4623 last_ch = add_till_closing_bracket(dest, input, end_ch);
4624 if (last_ch == 0) /* error? */
4627 #error Simple code to only allow ${var} is not implemented
4630 o_addstr(as_string, dest->data + pos);
4631 o_addchr(as_string, last_ch);
4634 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4635 && (end_ch & 0xff00)
4637 /* close the first block: */
4638 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4639 /* while parsing N from ${var:N[:M]}
4640 * or pattern from ${var/[/]pattern[/repl]} */
4641 if ((end_ch & 0xff) == last_ch) {
4642 /* got ':' or '/'- parse the rest */
4647 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4648 /* it's ${var:N} - emulate :999999999 */
4649 o_addstr(dest, "999999999");
4650 } /* else: it's ${var/[/]pattern} */
4654 len_single_ch = 0; /* it can't be ${#C} op */
4656 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4659 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4663 ch = i_getch(input);
4664 nommu_addchr(as_string, ch);
4665 # if ENABLE_FEATURE_SH_MATH
4666 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4667 ch = i_getch(input);
4668 nommu_addchr(as_string, ch);
4669 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4670 o_addchr(dest, /*quote_mask |*/ '+');
4673 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4674 return 0; /* error */
4676 o_addstr(as_string, dest->data + pos);
4677 o_addchr(as_string, ')');
4678 o_addchr(as_string, ')');
4680 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4684 # if ENABLE_HUSH_TICK
4685 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4686 o_addchr(dest, quote_mask | '`');
4689 if (!add_till_closing_bracket(dest, input, ')'))
4690 return 0; /* error */
4692 o_addstr(as_string, dest->data + pos);
4693 o_addchr(as_string, ')');
4695 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4701 ch = i_getch(input);
4702 nommu_addchr(as_string, ch);
4703 ch = i_peek_and_eat_bkslash_nl(input);
4704 if (isalnum(ch)) { /* it's $_name or $_123 */
4709 /* TODO: $_ and $-: */
4710 /* $_ Shell or shell script name; or last argument of last command
4711 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4712 * but in command's env, set to full pathname used to invoke it */
4713 /* $- Option flags set by set builtin or shell options (-i etc) */
4715 o_addQchr(dest, '$');
4717 debug_printf_parse("parse_dollar return 1 (ok)\n");
4723 # if BASH_PATTERN_SUBST
4724 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4725 encode_string(dest, input, dquote_end, process_bkslash)
4727 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4728 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4729 encode_string(dest, input, dquote_end)
4731 #define as_string NULL
4735 # if BASH_PATTERN_SUBST
4736 /* all parameters are needed, no macro tricks */
4738 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4739 encode_string(as_string, dest, input, dquote_end)
4742 static int encode_string(o_string *as_string,
4744 struct in_str *input,
4746 int process_bkslash)
4748 #if !BASH_PATTERN_SUBST
4749 const int process_bkslash = 1;
4755 ch = i_getch(input);
4757 nommu_addchr(as_string, ch);
4758 if (ch == dquote_end) { /* may be only '"' or EOF */
4759 debug_printf_parse("encode_string return 1 (ok)\n");
4762 /* note: can't move it above ch == dquote_end check! */
4764 syntax_error_unterm_ch('"');
4765 return 0; /* error */
4769 next = i_peek(input);
4771 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4772 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4773 if (process_bkslash && ch == '\\') {
4775 syntax_error("\\<eof>");
4779 * "The backslash retains its special meaning [in "..."]
4780 * only when followed by one of the following characters:
4781 * $, `, ", \, or <newline>. A double quote may be quoted
4782 * within double quotes by preceding it with a backslash."
4783 * NB: in (unquoted) heredoc, above does not apply to ",
4784 * therefore we check for it by "next == dquote_end" cond.
4786 if (next == dquote_end || strchr("$`\\\n", next)) {
4787 ch = i_getch(input); /* eat next */
4789 goto again; /* skip \<newline> */
4790 } /* else: ch remains == '\\', and we double it below: */
4791 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4792 nommu_addchr(as_string, ch);
4796 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4797 debug_printf_parse("encode_string return 0: "
4798 "parse_dollar returned 0 (error)\n");
4803 #if ENABLE_HUSH_TICK
4805 //unsigned pos = dest->length;
4806 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4807 o_addchr(dest, 0x80 | '`');
4808 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4809 return 0; /* error */
4810 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4811 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4815 o_addQchr(dest, ch);
4821 * Scan input until EOF or end_trigger char.
4822 * Return a list of pipes to execute, or NULL on EOF
4823 * or if end_trigger character is met.
4824 * On syntax error, exit if shell is not interactive,
4825 * reset parsing machinery and start parsing anew,
4826 * or return ERR_PTR.
4828 static struct pipe *parse_stream(char **pstring,
4829 struct in_str *input,
4832 struct parse_context ctx;
4833 o_string dest = NULL_O_STRING;
4836 /* Single-quote triggers a bypass of the main loop until its mate is
4837 * found. When recursing, quote state is passed in via dest->o_expflags.
4839 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4840 end_trigger ? end_trigger : 'X');
4843 /* If very first arg is "" or '', dest.data may end up NULL.
4844 * Preventing this: */
4845 o_addchr(&dest, '\0');
4848 /* We used to separate words on $IFS here. This was wrong.
4849 * $IFS is used only for word splitting when $var is expanded,
4850 * here we should use blank chars as separators, not $IFS
4853 if (MAYBE_ASSIGNMENT != 0)
4854 dest.o_assignment = MAYBE_ASSIGNMENT;
4855 initialize_context(&ctx);
4858 const char *is_blank;
4859 const char *is_special;
4863 redir_type redir_style;
4865 ch = i_getch(input);
4866 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4867 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4872 syntax_error_unterm_str("here document");
4875 if (end_trigger == ')') {
4876 syntax_error_unterm_ch('(');
4879 if (end_trigger == '}') {
4880 syntax_error_unterm_ch('{');
4884 if (done_word(&dest, &ctx)) {
4888 done_pipe(&ctx, PIPE_SEQ);
4890 /* If we got nothing... */
4891 /* (this makes bare "&" cmd a no-op.
4892 * bash says: "syntax error near unexpected token '&'") */
4893 if (pi->num_cmds == 0
4894 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4900 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4902 *pstring = ctx.as_string.data;
4904 o_free_unsafe(&ctx.as_string);
4907 debug_printf_parse("parse_stream return %p\n", pi);
4910 nommu_addchr(&ctx.as_string, ch);
4914 next = i_peek(input);
4916 is_special = "{}<>;&|()#'" /* special outside of "str" */
4917 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4918 /* Are { and } special here? */
4919 if (ctx.command->argv /* word [word]{... - non-special */
4920 || dest.length /* word{... - non-special */
4921 || dest.has_quoted_part /* ""{... - non-special */
4922 || (next != ';' /* }; - special */
4923 && next != ')' /* }) - special */
4924 && next != '(' /* {( - special */
4925 && next != '&' /* }& and }&& ... - special */
4926 && next != '|' /* }|| ... - special */
4927 && !strchr(defifs, next) /* {word - non-special */
4930 /* They are not special, skip "{}" */
4933 is_special = strchr(is_special, ch);
4934 is_blank = strchr(defifs, ch);
4936 if (!is_special && !is_blank) { /* ordinary char */
4938 o_addQchr(&dest, ch);
4939 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4940 || dest.o_assignment == WORD_IS_KEYWORD)
4942 && is_well_formed_var_name(dest.data, '=')
4944 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4945 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4951 if (done_word(&dest, &ctx)) {
4955 /* Is this a case when newline is simply ignored?
4957 * "cmd | <newline> cmd ..."
4958 * "case ... in <newline> word) ..."
4960 if (IS_NULL_CMD(ctx.command)
4961 && dest.length == 0 && !dest.has_quoted_part
4963 /* This newline can be ignored. But...
4964 * Without check #1, interactive shell
4965 * ignores even bare <newline>,
4966 * and shows the continuation prompt:
4967 * ps1_prompt$ <enter>
4968 * ps2> _ <=== wrong, should be ps1
4969 * Without check #2, "cmd & <newline>"
4970 * is similarly mistreated.
4971 * (BTW, this makes "cmd & cmd"
4972 * and "cmd && cmd" non-orthogonal.
4973 * Really, ask yourself, why
4974 * "cmd && <newline>" doesn't start
4975 * cmd but waits for more input?
4976 * The only reason is that it might be
4977 * a "cmd1 && <nl> cmd2 &" construct,
4978 * cmd1 may need to run in BG).
4980 struct pipe *pi = ctx.list_head;
4981 if (pi->num_cmds != 0 /* check #1 */
4982 && pi->followup != PIPE_BG /* check #2 */
4987 /* Treat newline as a command separator. */
4988 done_pipe(&ctx, PIPE_SEQ);
4989 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4991 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4996 dest.o_assignment = MAYBE_ASSIGNMENT;
4997 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4999 /* note: if (is_blank) continue;
5000 * will still trigger for us */
5004 /* "cmd}" or "cmd }..." without semicolon or &:
5005 * } is an ordinary char in this case, even inside { cmd; }
5006 * Pathological example: { ""}; } should exec "}" cmd
5009 if (dest.length != 0 /* word} */
5010 || dest.has_quoted_part /* ""} */
5014 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
5015 /* Generally, there should be semicolon: "cmd; }"
5016 * However, bash allows to omit it if "cmd" is
5017 * a group. Examples:
5020 * { echo 0 >&2 | { echo 1; } }
5021 * { while false; do :; done }
5022 * { case a in b) ;; esac }
5024 if (ctx.command->group)
5028 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5029 /* Can't be an end of {cmd}, skip the check */
5030 goto skip_end_trigger;
5031 /* else: } does terminate a group */
5034 if (end_trigger && end_trigger == ch
5035 && (ch != ';' || heredoc_cnt == 0)
5036 #if ENABLE_HUSH_CASE
5038 || ctx.ctx_res_w != RES_MATCH
5039 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5044 /* This is technically valid:
5045 * { cat <<HERE; }; echo Ok
5049 * but we don't support this.
5050 * We require heredoc to be in enclosing {}/(),
5053 syntax_error_unterm_str("here document");
5056 if (done_word(&dest, &ctx)) {
5059 done_pipe(&ctx, PIPE_SEQ);
5060 dest.o_assignment = MAYBE_ASSIGNMENT;
5061 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5062 /* Do we sit outside of any if's, loops or case's? */
5064 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5068 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5070 *pstring = ctx.as_string.data;
5072 o_free_unsafe(&ctx.as_string);
5074 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5075 /* Example: bare "{ }", "()" */
5076 G.last_exitcode = 2; /* bash compat */
5077 syntax_error_unexpected_ch(ch);
5080 debug_printf_parse("parse_stream return %p: "
5081 "end_trigger char found\n",
5084 return ctx.list_head;
5091 /* Catch <, > before deciding whether this word is
5092 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5095 redir_fd = redirect_opt_num(&dest);
5096 if (done_word(&dest, &ctx)) {
5099 redir_style = REDIRECT_OVERWRITE;
5101 redir_style = REDIRECT_APPEND;
5102 ch = i_getch(input);
5103 nommu_addchr(&ctx.as_string, ch);
5106 else if (next == '(') {
5107 syntax_error(">(process) not supported");
5111 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5113 continue; /* back to top of while (1) */
5115 redir_fd = redirect_opt_num(&dest);
5116 if (done_word(&dest, &ctx)) {
5119 redir_style = REDIRECT_INPUT;
5121 redir_style = REDIRECT_HEREDOC;
5123 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5124 ch = i_getch(input);
5125 nommu_addchr(&ctx.as_string, ch);
5126 } else if (next == '>') {
5127 redir_style = REDIRECT_IO;
5128 ch = i_getch(input);
5129 nommu_addchr(&ctx.as_string, ch);
5132 else if (next == '(') {
5133 syntax_error("<(process) not supported");
5137 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5139 continue; /* back to top of while (1) */
5141 if (dest.length == 0 && !dest.has_quoted_part) {
5142 /* skip "#comment" */
5145 if (ch == EOF || ch == '\n')
5148 /* note: we do not add it to &ctx.as_string */
5150 nommu_addchr(&ctx.as_string, '\n');
5151 continue; /* back to top of while (1) */
5156 /* It's "\<newline>" */
5158 /* Remove trailing '\' from ctx.as_string */
5159 ctx.as_string.data[--ctx.as_string.length] = '\0';
5161 ch = i_getch(input); /* eat it */
5162 continue; /* back to top of while (1) */
5167 if (dest.o_assignment == MAYBE_ASSIGNMENT
5168 /* check that we are not in word in "a=1 2>word b=1": */
5169 && !ctx.pending_redirect
5171 /* ch is a special char and thus this word
5172 * cannot be an assignment */
5173 dest.o_assignment = NOT_ASSIGNMENT;
5174 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5177 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5180 case '#': /* non-comment #: "echo a#b" etc */
5181 o_addQchr(&dest, ch);
5185 syntax_error("\\<eof>");
5188 ch = i_getch(input);
5189 /* note: ch != '\n' (that case does not reach this place) */
5190 o_addchr(&dest, '\\');
5191 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5192 o_addchr(&dest, ch);
5193 nommu_addchr(&ctx.as_string, ch);
5194 /* Example: echo Hello \2>file
5195 * we need to know that word 2 is quoted */
5196 dest.has_quoted_part = 1;
5199 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5200 debug_printf_parse("parse_stream parse error: "
5201 "parse_dollar returned 0 (error)\n");
5206 dest.has_quoted_part = 1;
5207 if (next == '\'' && !ctx.pending_redirect) {
5208 insert_empty_quoted_str_marker:
5209 nommu_addchr(&ctx.as_string, next);
5210 i_getch(input); /* eat second ' */
5211 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5212 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5215 ch = i_getch(input);
5217 syntax_error_unterm_ch('\'');
5220 nommu_addchr(&ctx.as_string, ch);
5223 o_addqchr(&dest, ch);
5228 dest.has_quoted_part = 1;
5229 if (next == '"' && !ctx.pending_redirect)
5230 goto insert_empty_quoted_str_marker;
5231 if (dest.o_assignment == NOT_ASSIGNMENT)
5232 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5233 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5235 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5237 #if ENABLE_HUSH_TICK
5239 USE_FOR_NOMMU(unsigned pos;)
5241 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5242 o_addchr(&dest, '`');
5243 USE_FOR_NOMMU(pos = dest.length;)
5244 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5247 o_addstr(&ctx.as_string, dest.data + pos);
5248 o_addchr(&ctx.as_string, '`');
5250 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5251 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5256 #if ENABLE_HUSH_CASE
5259 if (done_word(&dest, &ctx)) {
5262 done_pipe(&ctx, PIPE_SEQ);
5263 #if ENABLE_HUSH_CASE
5264 /* Eat multiple semicolons, detect
5265 * whether it means something special */
5270 ch = i_getch(input);
5271 nommu_addchr(&ctx.as_string, ch);
5272 if (ctx.ctx_res_w == RES_CASE_BODY) {
5273 ctx.ctx_dsemicolon = 1;
5274 ctx.ctx_res_w = RES_MATCH;
5280 /* We just finished a cmd. New one may start
5281 * with an assignment */
5282 dest.o_assignment = MAYBE_ASSIGNMENT;
5283 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5286 if (done_word(&dest, &ctx)) {
5290 ch = i_getch(input);
5291 nommu_addchr(&ctx.as_string, ch);
5292 done_pipe(&ctx, PIPE_AND);
5294 done_pipe(&ctx, PIPE_BG);
5298 if (done_word(&dest, &ctx)) {
5301 #if ENABLE_HUSH_CASE
5302 if (ctx.ctx_res_w == RES_MATCH)
5303 break; /* we are in case's "word | word)" */
5305 if (next == '|') { /* || */
5306 ch = i_getch(input);
5307 nommu_addchr(&ctx.as_string, ch);
5308 done_pipe(&ctx, PIPE_OR);
5310 /* we could pick up a file descriptor choice here
5311 * with redirect_opt_num(), but bash doesn't do it.
5312 * "echo foo 2| cat" yields "foo 2". */
5317 #if ENABLE_HUSH_CASE
5318 /* "case... in [(]word)..." - skip '(' */
5319 if (ctx.ctx_res_w == RES_MATCH
5320 && ctx.command->argv == NULL /* not (word|(... */
5321 && dest.length == 0 /* not word(... */
5322 && dest.has_quoted_part == 0 /* not ""(... */
5328 if (parse_group(&dest, &ctx, input, ch) != 0) {
5333 #if ENABLE_HUSH_CASE
5334 if (ctx.ctx_res_w == RES_MATCH)
5338 /* proper use of this character is caught by end_trigger:
5339 * if we see {, we call parse_group(..., end_trigger='}')
5340 * and it will match } earlier (not here). */
5341 G.last_exitcode = 2;
5342 syntax_error_unexpected_ch(ch);
5346 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5351 G.last_exitcode = 1;
5354 struct parse_context *pctx;
5355 IF_HAS_KEYWORDS(struct parse_context *p2;)
5357 /* Clean up allocated tree.
5358 * Sample for finding leaks on syntax error recovery path.
5359 * Run it from interactive shell, watch pmap `pidof hush`.
5360 * while if false; then false; fi; do break; fi
5361 * Samples to catch leaks at execution:
5362 * while if (true | { true;}); then echo ok; fi; do break; done
5363 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5367 /* Update pipe/command counts,
5368 * otherwise freeing may miss some */
5369 done_pipe(pctx, PIPE_SEQ);
5370 debug_printf_clean("freeing list %p from ctx %p\n",
5371 pctx->list_head, pctx);
5372 debug_print_tree(pctx->list_head, 0);
5373 free_pipe_list(pctx->list_head);
5374 debug_printf_clean("freed list %p\n", pctx->list_head);
5376 o_free_unsafe(&pctx->as_string);
5378 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5382 IF_HAS_KEYWORDS(pctx = p2;)
5383 } while (HAS_KEYWORDS && pctx);
5396 /*** Execution routines ***/
5398 /* Expansion can recurse, need forward decls: */
5399 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5400 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5401 #define expand_string_to_string(str, do_unbackslash) \
5402 expand_string_to_string(str)
5404 static char *expand_string_to_string(const char *str, int do_unbackslash);
5405 #if ENABLE_HUSH_TICK
5406 static int process_command_subs(o_string *dest, const char *s);
5409 /* expand_strvec_to_strvec() takes a list of strings, expands
5410 * all variable references within and returns a pointer to
5411 * a list of expanded strings, possibly with larger number
5412 * of strings. (Think VAR="a b"; echo $VAR).
5413 * This new list is allocated as a single malloc block.
5414 * NULL-terminated list of char* pointers is at the beginning of it,
5415 * followed by strings themselves.
5416 * Caller can deallocate entire list by single free(list). */
5418 /* A horde of its helpers come first: */
5420 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5422 while (--len >= 0) {
5425 #if ENABLE_HUSH_BRACE_EXPANSION
5426 if (c == '{' || c == '}') {
5427 /* { -> \{, } -> \} */
5429 /* And now we want to add { or } and continue:
5432 * luckily, just falling through achieves this.
5438 /* \z -> \\\z; \<eol> -> \\<eol> */
5443 o_addchr(o, *str++);
5449 /* Store given string, finalizing the word and starting new one whenever
5450 * we encounter IFS char(s). This is used for expanding variable values.
5451 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5452 * Return in *ended_with_ifs:
5453 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5455 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5457 int last_is_ifs = 0;
5462 if (!*str) /* EOL - do not finalize word */
5464 word_len = strcspn(str, G.ifs);
5466 /* We have WORD_LEN leading non-IFS chars */
5467 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5468 o_addblock(output, str, word_len);
5470 /* Protect backslashes against globbing up :)
5471 * Example: "v='\*'; echo b$v" prints "b\*"
5472 * (and does not try to glob on "*")
5474 o_addblock_duplicate_backslash(output, str, word_len);
5475 /*/ Why can't we do it easier? */
5476 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5477 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5481 if (!*str) /* EOL - do not finalize word */
5485 /* We know str here points to at least one IFS char */
5487 str += strspn(str, G.ifs); /* skip IFS chars */
5488 if (!*str) /* EOL - do not finalize word */
5491 /* Start new word... but not always! */
5492 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5493 if (output->has_quoted_part
5494 /* Case "v=' a'; echo $v":
5495 * here nothing precedes the space in $v expansion,
5496 * therefore we should not finish the word
5497 * (IOW: if there *is* word to finalize, only then do it):
5499 || (n > 0 && output->data[output->length - 1])
5501 o_addchr(output, '\0');
5502 debug_print_list("expand_on_ifs", output, n);
5503 n = o_save_ptr(output, n);
5508 *ended_with_ifs = last_is_ifs;
5509 debug_print_list("expand_on_ifs[1]", output, n);
5513 /* Helper to expand $((...)) and heredoc body. These act as if
5514 * they are in double quotes, with the exception that they are not :).
5515 * Just the rules are similar: "expand only $var and `cmd`"
5517 * Returns malloced string.
5518 * As an optimization, we return NULL if expansion is not needed.
5520 #if !BASH_PATTERN_SUBST
5521 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5522 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5523 encode_then_expand_string(str)
5525 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5527 #if !BASH_PATTERN_SUBST
5528 const int do_unbackslash = 1;
5531 struct in_str input;
5532 o_string dest = NULL_O_STRING;
5534 if (!strchr(str, '$')
5535 && !strchr(str, '\\')
5536 #if ENABLE_HUSH_TICK
5537 && !strchr(str, '`')
5543 /* We need to expand. Example:
5544 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5546 setup_string_in_str(&input, str);
5547 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5548 //TODO: error check (encode_string returns 0 on error)?
5549 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5550 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5551 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5552 o_free_unsafe(&dest);
5556 #if ENABLE_FEATURE_SH_MATH
5557 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5559 arith_state_t math_state;
5563 math_state.lookupvar = get_local_var_value;
5564 math_state.setvar = set_local_var_from_halves;
5565 //math_state.endofname = endofname;
5566 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5567 res = arith(&math_state, exp_str ? exp_str : arg);
5570 *errmsg_p = math_state.errmsg;
5571 if (math_state.errmsg)
5572 msg_and_die_if_script(math_state.errmsg);
5577 #if BASH_PATTERN_SUBST
5578 /* ${var/[/]pattern[/repl]} helpers */
5579 static char *strstr_pattern(char *val, const char *pattern, int *size)
5582 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5583 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5590 /* Optimization: if "*pat" did not match the start of "string",
5591 * we know that "tring", "ring" etc will not match too:
5593 if (pattern[0] == '*')
5598 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5600 char *result = NULL;
5601 unsigned res_len = 0;
5602 unsigned repl_len = strlen(repl);
5606 char *s = strstr_pattern(val, pattern, &size);
5610 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5611 strcpy(mempcpy(result + res_len, val, s - val), repl);
5612 res_len += (s - val) + repl_len;
5613 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5619 if (*val && result) {
5620 result = xrealloc(result, res_len + strlen(val) + 1);
5621 strcpy(result + res_len, val);
5622 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5624 debug_printf_varexp("result:'%s'\n", result);
5627 #endif /* BASH_PATTERN_SUBST */
5630 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5632 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5634 const char *val = NULL;
5635 char *to_be_freed = NULL;
5640 char exp_save = exp_save; /* for compiler */
5641 char *exp_saveptr; /* points to expansion operator */
5642 char *exp_word = exp_word; /* for compiler */
5645 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5647 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5649 first_char = arg[0] = arg0 & 0x7f;
5652 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5653 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5654 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5655 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5657 /* It must be length operator: ${#var} */
5661 /* Maybe handle parameter expansion */
5662 if (exp_saveptr /* if 2nd char is one of expansion operators */
5663 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5665 /* ${?:0}, ${#[:]%0} etc */
5666 exp_saveptr = var + 1;
5668 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5669 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5671 exp_op = exp_save = *exp_saveptr;
5673 exp_word = exp_saveptr + 1;
5674 if (exp_op == ':') {
5675 exp_op = *exp_word++;
5676 //TODO: try ${var:} and ${var:bogus} in non-bash config
5678 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5680 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5685 *exp_saveptr = '\0';
5686 } /* else: it's not an expansion op, but bare ${var} */
5689 /* Look up the variable in question */
5690 if (isdigit(var[0])) {
5691 /* parse_dollar should have vetted var for us */
5692 int n = xatoi_positive(var);
5693 if (n < G.global_argc)
5694 val = G.global_argv[n];
5695 /* else val remains NULL: $N with too big N */
5699 val = utoa(G.root_pid);
5701 case '!': /* bg pid */
5702 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5704 case '?': /* exitcode */
5705 val = utoa(G.last_exitcode);
5707 case '#': /* argc */
5708 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5711 val = get_local_var_value(var);
5715 /* Handle any expansions */
5716 if (exp_op == 'L') {
5717 reinit_unicode_for_hush();
5718 debug_printf_expand("expand: length(%s)=", val);
5719 val = utoa(val ? unicode_strlen(val) : 0);
5720 debug_printf_expand("%s\n", val);
5721 } else if (exp_op) {
5722 if (exp_op == '%' || exp_op == '#') {
5723 /* Standard-mandated substring removal ops:
5724 * ${parameter%word} - remove smallest suffix pattern
5725 * ${parameter%%word} - remove largest suffix pattern
5726 * ${parameter#word} - remove smallest prefix pattern
5727 * ${parameter##word} - remove largest prefix pattern
5729 * Word is expanded to produce a glob pattern.
5730 * Then var's value is matched to it and matching part removed.
5732 if (val && val[0]) {
5736 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5737 if (exp_op == *exp_word) /* ## or %% */
5739 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5741 exp_word = exp_exp_word;
5742 /* HACK ALERT. We depend here on the fact that
5743 * G.global_argv and results of utoa and get_local_var_value
5744 * are actually in writable memory:
5745 * scan_and_match momentarily stores NULs there. */
5747 loc = scan_and_match(t, exp_word, scan_flags);
5748 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5749 // exp_op, t, exp_word, loc);
5751 if (loc) { /* match was found */
5752 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5753 val = loc; /* take right part */
5755 val = to_be_freed = xstrndup(val, loc - val); /* left */
5759 #if BASH_PATTERN_SUBST
5760 else if (exp_op == '/' || exp_op == '\\') {
5761 /* It's ${var/[/]pattern[/repl]} thing.
5762 * Note that in encoded form it has TWO parts:
5763 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5764 * and if // is used, it is encoded as \:
5765 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5767 /* Empty variable always gives nothing: */
5768 // "v=''; echo ${v/*/w}" prints "", not "w"
5769 if (val && val[0]) {
5770 /* pattern uses non-standard expansion.
5771 * repl should be unbackslashed and globbed
5772 * by the usual expansion rules:
5774 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5775 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5776 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5777 * v='a bz'; echo ${v/a*z/\z} prints "z"
5778 * (note that a*z _pattern_ is never globbed!)
5780 char *pattern, *repl, *t;
5781 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5783 pattern = xstrdup(exp_word);
5784 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5785 *p++ = SPECIAL_VAR_SYMBOL;
5787 p = strchr(p, SPECIAL_VAR_SYMBOL);
5789 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5790 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5791 /* HACK ALERT. We depend here on the fact that
5792 * G.global_argv and results of utoa and get_local_var_value
5793 * are actually in writable memory:
5794 * replace_pattern momentarily stores NULs there. */
5796 to_be_freed = replace_pattern(t,
5798 (repl ? repl : exp_word),
5800 if (to_be_freed) /* at least one replace happened */
5806 #endif /* BASH_PATTERN_SUBST */
5807 else if (exp_op == ':') {
5808 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5809 /* It's ${var:N[:M]} bashism.
5810 * Note that in encoded form it has TWO parts:
5811 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5816 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5819 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5820 *p++ = SPECIAL_VAR_SYMBOL;
5822 p = strchr(p, SPECIAL_VAR_SYMBOL);
5824 len = expand_and_evaluate_arith(exp_word, &errmsg);
5827 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5829 /* negative beg counts from the end */
5830 beg = (arith_t)strlen(val) + beg;
5831 if (beg < 0) /* ${v: -999999} is "" */
5834 debug_printf_varexp("from val:'%s'\n", val);
5836 /* in bash, len=-n means strlen()-n */
5837 len = (arith_t)strlen(val) - beg + len;
5838 if (len < 0) /* bash compat */
5839 msg_and_die_if_script("%s: substring expression < 0", var);
5841 if (len <= 0 || !val || beg >= strlen(val)) {
5845 /* Paranoia. What if user entered 9999999999999
5846 * which fits in arith_t but not int? */
5849 val = to_be_freed = xstrndup(val + beg, len);
5851 debug_printf_varexp("val:'%s'\n", val);
5852 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5853 msg_and_die_if_script("malformed ${%s:...}", var);
5856 } else { /* one of "-=+?" */
5857 /* Standard-mandated substitution ops:
5858 * ${var?word} - indicate error if unset
5859 * If var is unset, word (or a message indicating it is unset
5860 * if word is null) is written to standard error
5861 * and the shell exits with a non-zero exit status.
5862 * Otherwise, the value of var is substituted.
5863 * ${var-word} - use default value
5864 * If var is unset, word is substituted.
5865 * ${var=word} - assign and use default value
5866 * If var is unset, word is assigned to var.
5867 * In all cases, final value of var is substituted.
5868 * ${var+word} - use alternative value
5869 * If var is unset, null is substituted.
5870 * Otherwise, word is substituted.
5872 * Word is subjected to tilde expansion, parameter expansion,
5873 * command substitution, and arithmetic expansion.
5874 * If word is not needed, it is not expanded.
5876 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5877 * but also treat null var as if it is unset.
5879 int use_word = (!val || ((exp_save == ':') && !val[0]));
5881 use_word = !use_word;
5882 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5883 (exp_save == ':') ? "true" : "false", use_word);
5885 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5887 exp_word = to_be_freed;
5888 if (exp_op == '?') {
5889 /* mimic bash message */
5890 msg_and_die_if_script("%s: %s",
5894 : "parameter null or not set"
5895 /* ash has more specific messages, a-la: */
5896 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5898 //TODO: how interactive bash aborts expansion mid-command?
5903 if (exp_op == '=') {
5904 /* ${var=[word]} or ${var:=[word]} */
5905 if (isdigit(var[0]) || var[0] == '#') {
5906 /* mimic bash message */
5907 msg_and_die_if_script("$%s: cannot assign in this way", var);
5910 char *new_var = xasprintf("%s=%s", var, val);
5911 set_local_var(new_var, /*flag:*/ 0);
5915 } /* one of "-=+?" */
5917 *exp_saveptr = exp_save;
5923 *to_be_freed_pp = to_be_freed;
5927 /* Expand all variable references in given string, adding words to list[]
5928 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5929 * to be filled). This routine is extremely tricky: has to deal with
5930 * variables/parameters with whitespace, $* and $@, and constructs like
5931 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5932 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5934 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5935 * expansion of right-hand side of assignment == 1-element expand.
5937 char cant_be_null = 0; /* only bit 0x80 matters */
5938 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5941 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5942 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5943 debug_print_list("expand_vars_to_list", output, n);
5944 n = o_save_ptr(output, n);
5945 debug_print_list("expand_vars_to_list[0]", output, n);
5947 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5949 char *to_be_freed = NULL;
5950 const char *val = NULL;
5951 #if ENABLE_HUSH_TICK
5952 o_string subst_result = NULL_O_STRING;
5954 #if ENABLE_FEATURE_SH_MATH
5955 char arith_buf[sizeof(arith_t)*3 + 2];
5959 o_addchr(output, '\0');
5960 n = o_save_ptr(output, n);
5964 o_addblock(output, arg, p - arg);
5965 debug_print_list("expand_vars_to_list[1]", output, n);
5967 p = strchr(p, SPECIAL_VAR_SYMBOL);
5969 /* Fetch special var name (if it is indeed one of them)
5970 * and quote bit, force the bit on if singleword expansion -
5971 * important for not getting v=$@ expand to many words. */
5972 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5974 /* Is this variable quoted and thus expansion can't be null?
5975 * "$@" is special. Even if quoted, it can still
5976 * expand to nothing (not even an empty string),
5977 * thus it is excluded. */
5978 if ((first_ch & 0x7f) != '@')
5979 cant_be_null |= first_ch;
5981 switch (first_ch & 0x7f) {
5982 /* Highest bit in first_ch indicates that var is double-quoted */
5986 if (!G.global_argv[1])
5989 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5990 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5991 while (G.global_argv[i]) {
5992 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5993 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5994 if (G.global_argv[i++][0] && G.global_argv[i]) {
5995 /* this argv[] is not empty and not last:
5996 * put terminating NUL, start new word */
5997 o_addchr(output, '\0');
5998 debug_print_list("expand_vars_to_list[2]", output, n);
5999 n = o_save_ptr(output, n);
6000 debug_print_list("expand_vars_to_list[3]", output, n);
6004 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
6005 * and in this case should treat it like '$*' - see 'else...' below */
6006 if (first_ch == ('@'|0x80) /* quoted $@ */
6007 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
6010 o_addQstr(output, G.global_argv[i]);
6011 if (++i >= G.global_argc)
6013 o_addchr(output, '\0');
6014 debug_print_list("expand_vars_to_list[4]", output, n);
6015 n = o_save_ptr(output, n);
6017 } else { /* quoted $* (or v="$@" case): add as one word */
6019 o_addQstr(output, G.global_argv[i]);
6020 if (!G.global_argv[++i])
6023 o_addchr(output, G.ifs[0]);
6025 output->has_quoted_part = 1;
6029 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
6030 /* "Empty variable", used to make "" etc to not disappear */
6031 output->has_quoted_part = 1;
6033 cant_be_null = 0x80;
6035 #if ENABLE_HUSH_TICK
6036 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6037 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6039 /* Can't just stuff it into output o_string,
6040 * expanded result may need to be globbed
6042 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6043 G.last_exitcode = process_command_subs(&subst_result, arg);
6044 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6045 val = subst_result.data;
6048 #if ENABLE_FEATURE_SH_MATH
6049 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6052 arg++; /* skip '+' */
6053 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6054 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6055 res = expand_and_evaluate_arith(arg, NULL);
6056 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6057 sprintf(arith_buf, ARITH_FMT, res);
6063 val = expand_one_var(&to_be_freed, arg, &p);
6064 IF_HUSH_TICK(store_val:)
6065 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6066 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6067 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6068 if (val && val[0]) {
6069 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6072 } else { /* quoted $VAR, val will be appended below */
6073 output->has_quoted_part = 1;
6074 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6075 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6078 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6080 if (val && val[0]) {
6081 o_addQstr(output, val);
6085 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6086 * Do the check to avoid writing to a const string. */
6087 if (*p != SPECIAL_VAR_SYMBOL)
6088 *p = SPECIAL_VAR_SYMBOL;
6090 #if ENABLE_HUSH_TICK
6091 o_free(&subst_result);
6094 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6098 o_addchr(output, '\0');
6099 n = o_save_ptr(output, n);
6101 debug_print_list("expand_vars_to_list[a]", output, n);
6102 /* this part is literal, and it was already pre-quoted
6103 * if needed (much earlier), do not use o_addQstr here! */
6104 o_addstr_with_NUL(output, arg);
6105 debug_print_list("expand_vars_to_list[b]", output, n);
6106 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6107 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6110 /* allow to reuse list[n] later without re-growth */
6111 output->has_empty_slot = 1;
6113 o_addchr(output, '\0');
6119 static char **expand_variables(char **argv, unsigned expflags)
6123 o_string output = NULL_O_STRING;
6125 output.o_expflags = expflags;
6129 n = expand_vars_to_list(&output, n, *argv);
6132 debug_print_list("expand_variables", &output, n);
6134 /* output.data (malloced in one block) gets returned in "list" */
6135 list = o_finalize_list(&output, n);
6136 debug_print_strings("expand_variables[1]", list);
6140 static char **expand_strvec_to_strvec(char **argv)
6142 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6146 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6148 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6152 /* Used for expansion of right hand of assignments,
6153 * $((...)), heredocs, variable espansion parts.
6155 * NB: should NOT do globbing!
6156 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6158 static char *expand_string_to_string(const char *str, int do_unbackslash)
6160 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6161 const int do_unbackslash = 1;
6163 char *argv[2], **list;
6165 debug_printf_expand("string_to_string<='%s'\n", str);
6166 /* This is generally an optimization, but it also
6167 * handles "", which otherwise trips over !list[0] check below.
6168 * (is this ever happens that we actually get str="" here?)
6170 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6171 //TODO: Can use on strings with \ too, just unbackslash() them?
6172 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6173 return xstrdup(str);
6176 argv[0] = (char*)str;
6178 list = expand_variables(argv, do_unbackslash
6179 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6180 : EXP_FLAG_SINGLEWORD
6183 if (!list[0] || list[1])
6184 bb_error_msg_and_die("BUG in varexp2");
6185 /* actually, just move string 2*sizeof(char*) bytes back */
6186 overlapping_strcpy((char*)list, list[0]);
6188 unbackslash((char*)list);
6189 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6193 /* Used for "eval" builtin and case string */
6194 static char* expand_strvec_to_string(char **argv)
6198 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6199 /* Convert all NULs to spaces */
6204 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6205 bb_error_msg_and_die("BUG in varexp3");
6206 /* bash uses ' ' regardless of $IFS contents */
6211 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6212 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6216 static char **expand_assignments(char **argv, int count)
6221 G.expanded_assignments = p = NULL;
6222 /* Expand assignments into one string each */
6223 for (i = 0; i < count; i++) {
6224 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6226 G.expanded_assignments = NULL;
6231 static void switch_off_special_sigs(unsigned mask)
6234 while ((mask >>= 1) != 0) {
6238 #if ENABLE_HUSH_TRAP
6240 if (G_traps[sig] && !G_traps[sig][0])
6241 /* trap is '', has to remain SIG_IGN */
6244 G_traps[sig] = NULL;
6247 /* We are here only if no trap or trap was not '' */
6248 install_sighandler(sig, SIG_DFL);
6254 void re_execute_shell(char ***to_free, const char *s,
6255 char *g_argv0, char **g_argv,
6256 char **builtin_argv) NORETURN;
6258 static void reset_traps_to_defaults(void)
6260 /* This function is always called in a child shell
6261 * after fork (not vfork, NOMMU doesn't use this function).
6263 IF_HUSH_TRAP(unsigned sig;)
6266 /* Child shells are not interactive.
6267 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6268 * Testcase: (while :; do :; done) + ^Z should background.
6269 * Same goes for SIGTERM, SIGHUP, SIGINT.
6271 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6272 if (!G_traps && !mask)
6273 return; /* already no traps and no special sigs */
6275 /* Switch off special sigs */
6276 switch_off_special_sigs(mask);
6277 # if ENABLE_HUSH_JOB
6278 G_fatal_sig_mask = 0;
6280 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6281 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6282 * remain set in G.special_sig_mask */
6284 # if ENABLE_HUSH_TRAP
6288 /* Reset all sigs to default except ones with empty traps */
6289 for (sig = 0; sig < NSIG; sig++) {
6291 continue; /* no trap: nothing to do */
6292 if (!G_traps[sig][0])
6293 continue; /* empty trap: has to remain SIG_IGN */
6294 /* sig has non-empty trap, reset it: */
6296 G_traps[sig] = NULL;
6297 /* There is no signal for trap 0 (EXIT) */
6300 install_sighandler(sig, pick_sighandler(sig));
6307 static void re_execute_shell(char ***to_free, const char *s,
6308 char *g_argv0, char **g_argv,
6309 char **builtin_argv) NORETURN;
6310 static void re_execute_shell(char ***to_free, const char *s,
6311 char *g_argv0, char **g_argv,
6312 char **builtin_argv)
6314 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6315 /* delims + 2 * (number of bytes in printed hex numbers) */
6316 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6317 char *heredoc_argv[4];
6318 struct variable *cur;
6319 # if ENABLE_HUSH_FUNCTIONS
6320 struct function *funcp;
6324 unsigned long long empty_trap_mask;
6326 if (!g_argv0) { /* heredoc */
6327 argv = heredoc_argv;
6328 argv[0] = (char *) G.argv0_for_re_execing;
6329 argv[1] = (char *) "-<";
6330 argv[2] = (char *) s;
6332 pp = &argv[3]; /* used as pointer to empty environment */
6338 if (pp) while (*pp++)
6341 empty_trap_mask = 0;
6344 for (sig = 1; sig < NSIG; sig++) {
6345 if (G_traps[sig] && !G_traps[sig][0])
6346 empty_trap_mask |= 1LL << sig;
6350 sprintf(param_buf, NOMMU_HACK_FMT
6351 , (unsigned) G.root_pid
6352 , (unsigned) G.root_ppid
6353 , (unsigned) G.last_bg_pid
6354 , (unsigned) G.last_exitcode
6357 IF_HUSH_LOOPS(, G.depth_of_loop)
6359 # undef NOMMU_HACK_FMT
6360 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6361 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6364 for (cur = G.top_var; cur; cur = cur->next) {
6365 if (!cur->flg_export || cur->flg_read_only)
6368 # if ENABLE_HUSH_FUNCTIONS
6369 for (funcp = G.top_func; funcp; funcp = funcp->next)
6375 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6376 *pp++ = (char *) G.argv0_for_re_execing;
6378 for (cur = G.top_var; cur; cur = cur->next) {
6379 if (strcmp(cur->varstr, hush_version_str) == 0)
6381 if (cur->flg_read_only) {
6382 *pp++ = (char *) "-R";
6383 *pp++ = cur->varstr;
6384 } else if (!cur->flg_export) {
6385 *pp++ = (char *) "-V";
6386 *pp++ = cur->varstr;
6389 # if ENABLE_HUSH_FUNCTIONS
6390 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6391 *pp++ = (char *) "-F";
6392 *pp++ = funcp->name;
6393 *pp++ = funcp->body_as_string;
6396 /* We can pass activated traps here. Say, -Tnn:trap_string
6398 * However, POSIX says that subshells reset signals with traps
6400 * I tested bash-3.2 and it not only does that with true subshells
6401 * of the form ( list ), but with any forked children shells.
6402 * I set trap "echo W" WINCH; and then tried:
6404 * { echo 1; sleep 20; echo 2; } &
6405 * while true; do echo 1; sleep 20; echo 2; break; done &
6406 * true | { echo 1; sleep 20; echo 2; } | cat
6408 * In all these cases sending SIGWINCH to the child shell
6409 * did not run the trap. If I add trap "echo V" WINCH;
6410 * _inside_ group (just before echo 1), it works.
6412 * I conclude it means we don't need to pass active traps here.
6414 *pp++ = (char *) "-c";
6417 while (*++builtin_argv)
6418 *pp++ = *builtin_argv;
6419 *pp++ = (char *) "";
6424 /* *pp = NULL; - is already there */
6428 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6429 /* Don't propagate SIG_IGN to the child */
6430 if (SPECIAL_JOBSTOP_SIGS != 0)
6431 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6432 execve(bb_busybox_exec_path, argv, pp);
6433 /* Fallback. Useful for init=/bin/hush usage etc */
6434 if (argv[0][0] == '/')
6435 execve(argv[0], argv, pp);
6436 xfunc_error_retval = 127;
6437 bb_error_msg_and_die("can't re-execute the shell");
6439 #endif /* !BB_MMU */
6442 static int run_and_free_list(struct pipe *pi);
6444 /* Executing from string: eval, sh -c '...'
6445 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6446 * end_trigger controls how often we stop parsing
6447 * NUL: parse all, execute, return
6448 * ';': parse till ';' or newline, execute, repeat till EOF
6450 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6452 /* Why we need empty flag?
6453 * An obscure corner case "false; ``; echo $?":
6454 * empty command in `` should still set $? to 0.
6455 * But we can't just set $? to 0 at the start,
6456 * this breaks "false; echo `echo $?`" case.
6460 struct pipe *pipe_list;
6462 #if ENABLE_HUSH_INTERACTIVE
6463 if (end_trigger == ';')
6464 inp->promptmode = 0; /* PS1 */
6466 pipe_list = parse_stream(NULL, inp, end_trigger);
6467 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6468 /* If we are in "big" script
6469 * (not in `cmd` or something similar)...
6471 if (pipe_list == ERR_PTR && end_trigger == ';') {
6472 /* Discard cached input (rest of line) */
6473 int ch = inp->last_char;
6474 while (ch != EOF && ch != '\n') {
6475 //bb_error_msg("Discarded:'%c'", ch);
6480 /* This stream isn't empty */
6484 if (!pipe_list && empty)
6485 G.last_exitcode = 0;
6488 debug_print_tree(pipe_list, 0);
6489 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6490 run_and_free_list(pipe_list);
6492 if (G_flag_return_in_progress == 1)
6497 static void parse_and_run_string(const char *s)
6499 struct in_str input;
6500 setup_string_in_str(&input, s);
6501 parse_and_run_stream(&input, '\0');
6504 static void parse_and_run_file(FILE *f)
6506 struct in_str input;
6507 setup_file_in_str(&input, f);
6508 parse_and_run_stream(&input, ';');
6511 #if ENABLE_HUSH_TICK
6512 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6517 char **to_free = NULL;
6521 pid = BB_MMU ? xfork() : xvfork();
6522 if (pid == 0) { /* child */
6523 disable_restore_tty_pgrp_on_exit();
6524 /* Process substitution is not considered to be usual
6525 * 'command execution'.
6526 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6533 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6534 close(channel[0]); /* NB: close _first_, then move fd! */
6535 xmove_fd(channel[1], 1);
6536 /* Prevent it from trying to handle ctrl-z etc */
6537 IF_HUSH_JOB(G.run_list_level = 1;)
6538 # if ENABLE_HUSH_TRAP
6539 /* Awful hack for `trap` or $(trap).
6541 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6542 * contains an example where "trap" is executed in a subshell:
6544 * save_traps=$(trap)
6546 * eval "$save_traps"
6548 * Standard does not say that "trap" in subshell shall print
6549 * parent shell's traps. It only says that its output
6550 * must have suitable form, but then, in the above example
6551 * (which is not supposed to be normative), it implies that.
6553 * bash (and probably other shell) does implement it
6554 * (traps are reset to defaults, but "trap" still shows them),
6555 * but as a result, "trap" logic is hopelessly messed up:
6558 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6559 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6560 * # true | trap <--- trap is in subshell - no output (ditto)
6561 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6562 * trap -- 'echo Ho' SIGWINCH
6563 * # echo `(trap)` <--- in subshell in subshell - output
6564 * trap -- 'echo Ho' SIGWINCH
6565 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6566 * trap -- 'echo Ho' SIGWINCH
6568 * The rules when to forget and when to not forget traps
6569 * get really complex and nonsensical.
6571 * Our solution: ONLY bare $(trap) or `trap` is special.
6573 s = skip_whitespace(s);
6574 if (is_prefixed_with(s, "trap")
6575 && skip_whitespace(s + 4)[0] == '\0'
6577 static const char *const argv[] = { NULL, NULL };
6578 builtin_trap((char**)argv);
6579 fflush_all(); /* important */
6584 reset_traps_to_defaults();
6585 parse_and_run_string(s);
6586 _exit(G.last_exitcode);
6588 /* We re-execute after vfork on NOMMU. This makes this script safe:
6589 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6590 * huge=`cat BIG` # was blocking here forever
6593 re_execute_shell(&to_free,
6603 # if ENABLE_HUSH_FAST
6605 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6606 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6607 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6609 enable_restore_tty_pgrp_on_exit();
6614 return remember_FILE(xfdopen_for_read(channel[0]));
6617 /* Return code is exit status of the process that is run. */
6618 static int process_command_subs(o_string *dest, const char *s)
6621 struct in_str pipe_str;
6623 int status, ch, eol_cnt;
6625 fp = generate_stream_from_string(s, &pid);
6627 /* Now send results of command back into original context */
6628 setup_file_in_str(&pipe_str, fp);
6630 while ((ch = i_getch(&pipe_str)) != EOF) {
6636 o_addchr(dest, '\n');
6639 o_addQchr(dest, ch);
6642 debug_printf("done reading from `cmd` pipe, closing it\n");
6643 fclose_and_forget(fp);
6644 /* We need to extract exitcode. Test case
6645 * "true; echo `sleep 1; false` $?"
6647 safe_waitpid(pid, &status, 0);
6648 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6649 return WEXITSTATUS(status);
6651 #endif /* ENABLE_HUSH_TICK */
6654 static void setup_heredoc(struct redir_struct *redir)
6656 struct fd_pair pair;
6659 /* the _body_ of heredoc (misleading field name) */
6660 const char *heredoc = redir->rd_filename;
6667 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6668 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6672 len = strlen(heredoc);
6674 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6676 xmove_fd(pair.rd, redir->rd_fd);
6678 /* Try writing without forking. Newer kernels have
6679 * dynamically growing pipes. Must use non-blocking write! */
6682 written = write(pair.wr, heredoc, len);
6693 ndelay_off(pair.wr);
6695 /* Okay, pipe buffer was not big enough */
6696 /* Note: we must not create a stray child (bastard? :)
6697 * for the unsuspecting parent process. Child creates a grandchild
6698 * and exits before parent execs the process which consumes heredoc
6699 * (that exec happens after we return from this function) */
6706 disable_restore_tty_pgrp_on_exit();
6707 pid = BB_MMU ? xfork() : xvfork();
6711 close(redir->rd_fd); /* read side of the pipe */
6713 full_write(pair.wr, heredoc, len); /* may loop or block */
6716 /* Delegate blocking writes to another process */
6717 xmove_fd(pair.wr, STDOUT_FILENO);
6718 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6722 #if ENABLE_HUSH_FAST
6724 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6726 enable_restore_tty_pgrp_on_exit();
6732 wait(NULL); /* wait till child has died */
6738 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6739 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6742 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6744 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6745 sq[i].orig_fd = orig;
6746 sq[i].moved_to = moved;
6747 sq[i+1].orig_fd = -1; /* end marker */
6751 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6757 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6758 /* If we collide with an already moved fd... */
6759 if (fd == sq[i].moved_to) {
6760 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6761 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6762 if (sq[i].moved_to < 0) /* what? */
6766 if (fd == sq[i].orig_fd) {
6767 /* Example: echo Hello >/dev/null 1>&2 */
6768 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6773 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6774 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6775 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6776 if (moved_to < 0 && errno != EBADF)
6778 return append_squirrel(sq, i, fd, moved_to);
6781 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6786 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6787 /* If we collide with an already moved fd... */
6788 if (fd == sq[i].orig_fd) {
6790 * "echo 3>FILE 3>&- 3>FILE"
6791 * "echo 3>&- 3>FILE"
6792 * No need for last redirect to insert
6793 * another "need to close 3" indicator.
6795 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6800 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6801 return append_squirrel(sq, i, fd, -1);
6804 /* fd: redirect wants this fd to be used (e.g. 3>file).
6805 * Move all conflicting internally used fds,
6806 * and remember them so that we can restore them later.
6808 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6810 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6813 #if ENABLE_HUSH_INTERACTIVE
6814 if (fd == G.interactive_fd) {
6815 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6816 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6817 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6818 return 1; /* "we closed fd" */
6821 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6822 * (1) Redirect in a forked child. No need to save FILEs' fds,
6823 * we aren't going to use them anymore, ok to trash.
6824 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6825 * but how are we doing to restore them?
6826 * "fileno(fd) = new_fd" can't be done.
6831 /* If this one of script's fds? */
6832 if (save_FILEs_on_redirect(fd, avoid_fd))
6833 return 1; /* yes. "we closed fd" */
6835 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6836 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6837 return 0; /* "we did not close fd" */
6840 static void restore_redirects(struct squirrel *sq)
6844 for (i = 0; sq[i].orig_fd >= 0; i++) {
6845 if (sq[i].moved_to >= 0) {
6846 /* We simply die on error */
6847 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6848 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6850 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6851 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6852 close(sq[i].orig_fd);
6858 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6860 restore_redirected_FILEs();
6863 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6864 static void close_saved_fds_and_FILE_fds(void)
6866 if (G_interactive_fd)
6867 close(G_interactive_fd);
6868 close_all_FILE_list();
6872 static int internally_opened_fd(int fd, struct squirrel *sq)
6876 #if ENABLE_HUSH_INTERACTIVE
6877 if (fd == G.interactive_fd)
6880 /* If this one of script's fds? */
6881 if (fd_in_FILEs(fd))
6884 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6885 if (fd == sq[i].moved_to)
6891 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6892 * and stderr if they are redirected. */
6893 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6895 struct redir_struct *redir;
6897 for (redir = prog->redirects; redir; redir = redir->next) {
6901 if (redir->rd_type == REDIRECT_HEREDOC2) {
6902 /* "rd_fd<<HERE" case */
6903 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6904 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6906 debug_printf_parse("set heredoc '%s'\n",
6907 redir->rd_filename);
6908 setup_heredoc(redir);
6912 if (redir->rd_dup == REDIRFD_TO_FILE) {
6913 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6917 if (redir->rd_filename == NULL) {
6920 * "cmd >" (no filename)
6921 * "cmd > <file" (2nd redirect starts too early)
6923 syntax_error("invalid redirect");
6926 mode = redir_table[redir->rd_type].mode;
6927 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6928 newfd = open_or_warn(p, mode);
6931 /* Error message from open_or_warn can be lost
6932 * if stderr has been redirected, but bash
6933 * and ash both lose it as well
6934 * (though zsh doesn't!)
6938 if (newfd == redir->rd_fd && sqp) {
6939 /* open() gave us precisely the fd we wanted.
6940 * This means that this fd was not busy
6941 * (not opened to anywhere).
6942 * Remember to close it on restore:
6944 *sqp = add_squirrel_closed(*sqp, newfd);
6945 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6948 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6949 newfd = redir->rd_dup;
6952 if (newfd == redir->rd_fd)
6955 /* if "N>FILE": move newfd to redir->rd_fd */
6956 /* if "N>&M": dup newfd to redir->rd_fd */
6957 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6959 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6960 if (newfd == REDIRFD_CLOSE) {
6961 /* "N>&-" means "close me" */
6963 /* ^^^ optimization: saving may already
6964 * have closed it. If not... */
6965 close(redir->rd_fd);
6967 /* Sometimes we do another close on restore, getting EBADF.
6968 * Consider "echo 3>FILE 3>&-"
6969 * first redirect remembers "need to close 3",
6970 * and second redirect closes 3! Restore code then closes 3 again.
6973 /* if newfd is a script fd or saved fd, simulate EBADF */
6974 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6976 //bb_perror_msg_and_die("can't duplicate file descriptor");
6977 newfd = -1; /* same effect as code above */
6979 xdup2(newfd, redir->rd_fd);
6980 if (redir->rd_dup == REDIRFD_TO_FILE)
6981 /* "rd_fd > FILE" */
6983 /* else: "rd_fd > rd_dup" */
6989 static char *find_in_path(const char *arg)
6992 const char *PATH = get_local_var_value("PATH");
6998 const char *end = strchrnul(PATH, ':');
6999 int sz = end - PATH; /* must be int! */
7003 ret = xasprintf("%.*s/%s", sz, PATH, arg);
7005 /* We have xxx::yyyy in $PATH,
7006 * it means "use current dir" */
7009 if (access(ret, F_OK) == 0)
7022 static const struct built_in_command *find_builtin_helper(const char *name,
7023 const struct built_in_command *x,
7024 const struct built_in_command *end)
7027 if (strcmp(name, x->b_cmd) != 0) {
7031 debug_printf_exec("found builtin '%s'\n", name);
7036 static const struct built_in_command *find_builtin1(const char *name)
7038 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7040 static const struct built_in_command *find_builtin(const char *name)
7042 const struct built_in_command *x = find_builtin1(name);
7045 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7048 #if ENABLE_HUSH_FUNCTIONS
7049 static struct function **find_function_slot(const char *name)
7051 struct function **funcpp = &G.top_func;
7053 if (strcmp(name, (*funcpp)->name) == 0) {
7056 funcpp = &(*funcpp)->next;
7061 static const struct function *find_function(const char *name)
7063 const struct function *funcp = *find_function_slot(name);
7065 debug_printf_exec("found function '%s'\n", name);
7069 /* Note: takes ownership on name ptr */
7070 static struct function *new_function(char *name)
7072 struct function **funcpp = find_function_slot(name);
7073 struct function *funcp = *funcpp;
7075 if (funcp != NULL) {
7076 struct command *cmd = funcp->parent_cmd;
7077 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7079 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7081 /* Note: if !funcp->body, do not free body_as_string!
7082 * This is a special case of "-F name body" function:
7083 * body_as_string was not malloced! */
7085 free_pipe_list(funcp->body);
7087 free(funcp->body_as_string);
7091 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7092 cmd->argv[0] = funcp->name;
7093 cmd->group = funcp->body;
7095 cmd->group_as_string = funcp->body_as_string;
7099 debug_printf_exec("remembering new function '%s'\n", name);
7100 funcp = *funcpp = xzalloc(sizeof(*funcp));
7101 /*funcp->next = NULL;*/
7108 # if ENABLE_HUSH_UNSET
7109 static void unset_func(const char *name)
7111 struct function **funcpp = find_function_slot(name);
7112 struct function *funcp = *funcpp;
7114 if (funcp != NULL) {
7115 debug_printf_exec("freeing function '%s'\n", funcp->name);
7116 *funcpp = funcp->next;
7117 /* funcp is unlinked now, deleting it.
7118 * Note: if !funcp->body, the function was created by
7119 * "-F name body", do not free ->body_as_string
7120 * and ->name as they were not malloced. */
7122 free_pipe_list(funcp->body);
7125 free(funcp->body_as_string);
7134 #define exec_function(to_free, funcp, argv) \
7135 exec_function(funcp, argv)
7137 static void exec_function(char ***to_free,
7138 const struct function *funcp,
7139 char **argv) NORETURN;
7140 static void exec_function(char ***to_free,
7141 const struct function *funcp,
7147 argv[0] = G.global_argv[0];
7148 G.global_argv = argv;
7149 G.global_argc = n = 1 + string_array_len(argv + 1);
7151 // Example when we are here: "cmd | func"
7152 // func will run with saved-redirect fds open.
7153 // $ f() { echo /proc/self/fd/*; }
7155 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7156 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7159 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7160 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7161 // They are CLOEXEC so external programs won't see them, but
7162 // for "more correctness" we might want to close those extra fds here:
7163 //? close_saved_fds_and_FILE_fds();
7165 /* "we are in function, ok to use return" */
7166 G_flag_return_in_progress = -1;
7167 IF_HUSH_LOCAL(G.func_nest_level++;)
7169 /* On MMU, funcp->body is always non-NULL */
7170 n = run_list(funcp->body);
7174 //? close_saved_fds_and_FILE_fds();
7176 //TODO: check whether "true | func_with_return" works
7178 re_execute_shell(to_free,
7179 funcp->body_as_string,
7186 static int run_function(const struct function *funcp, char **argv)
7192 save_and_replace_G_args(&sv, argv);
7194 /* "we are in function, ok to use return" */
7195 sv_flg = G_flag_return_in_progress;
7196 G_flag_return_in_progress = -1;
7197 IF_HUSH_LOCAL(G.func_nest_level++;)
7199 /* On MMU, funcp->body is always non-NULL */
7202 /* Function defined by -F */
7203 parse_and_run_string(funcp->body_as_string);
7204 rc = G.last_exitcode;
7208 rc = run_list(funcp->body);
7211 # if ENABLE_HUSH_LOCAL
7213 struct variable *var;
7214 struct variable **var_pp;
7216 var_pp = &G.top_var;
7217 while ((var = *var_pp) != NULL) {
7218 if (var->func_nest_level < G.func_nest_level) {
7219 var_pp = &var->next;
7223 if (var->flg_export)
7224 bb_unsetenv(var->varstr);
7225 /* Remove from global list */
7226 *var_pp = var->next;
7232 G.func_nest_level--;
7235 G_flag_return_in_progress = sv_flg;
7237 restore_G_args(&sv, argv);
7241 #endif /* ENABLE_HUSH_FUNCTIONS */
7245 #define exec_builtin(to_free, x, argv) \
7246 exec_builtin(x, argv)
7248 #define exec_builtin(to_free, x, argv) \
7249 exec_builtin(to_free, argv)
7251 static void exec_builtin(char ***to_free,
7252 const struct built_in_command *x,
7253 char **argv) NORETURN;
7254 static void exec_builtin(char ***to_free,
7255 const struct built_in_command *x,
7261 //? close_saved_fds_and_FILE_fds();
7262 rcode = x->b_function(argv);
7267 /* On NOMMU, we must never block!
7268 * Example: { sleep 99 | read line; } & echo Ok
7270 re_execute_shell(to_free,
7279 static void execvp_or_die(char **argv) NORETURN;
7280 static void execvp_or_die(char **argv)
7283 debug_printf_exec("execing '%s'\n", argv[0]);
7284 /* Don't propagate SIG_IGN to the child */
7285 if (SPECIAL_JOBSTOP_SIGS != 0)
7286 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7287 execvp(argv[0], argv);
7289 if (errno == EACCES) e = 126;
7290 if (errno == ENOENT) e = 127;
7291 bb_perror_msg("can't execute '%s'", argv[0]);
7295 #if ENABLE_HUSH_MODE_X
7296 static void dump_cmd_in_x_mode(char **argv)
7298 if (G_x_mode && argv) {
7299 /* We want to output the line in one write op */
7307 len += strlen(argv[n++]) + 1;
7313 p += sprintf(p, " %s", argv[n++]);
7321 # define dump_cmd_in_x_mode(argv) ((void)0)
7325 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7326 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7327 #define pseudo_exec(nommu_save, command, argv_expanded) \
7328 pseudo_exec(command, argv_expanded)
7331 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7333 * Don't exit() here. If you don't exec, use _exit instead.
7334 * The at_exit handlers apparently confuse the calling process,
7335 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7337 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7338 char **argv, int assignment_cnt,
7339 char **argv_expanded) NORETURN;
7340 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7341 char **argv, int assignment_cnt,
7342 char **argv_expanded)
7346 new_env = expand_assignments(argv, assignment_cnt);
7347 dump_cmd_in_x_mode(new_env);
7349 if (!argv[assignment_cnt]) {
7350 /* Case when we are here: ... | var=val | ...
7351 * (note that we do not exit early, i.e., do not optimize out
7352 * expand_assignments(): think about ... | var=`sleep 1` | ...
7354 free_strings(new_env);
7355 _exit(EXIT_SUCCESS);
7359 set_vars_and_save_old(new_env);
7360 free(new_env); /* optional */
7361 /* we can also destroy set_vars_and_save_old's return value,
7364 nommu_save->new_env = new_env;
7365 nommu_save->old_vars = set_vars_and_save_old(new_env);
7368 if (argv_expanded) {
7369 argv = argv_expanded;
7371 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7373 nommu_save->argv = argv;
7376 dump_cmd_in_x_mode(argv);
7378 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7379 if (strchr(argv[0], '/') != NULL)
7383 #if ENABLE_HUSH_FUNCTIONS
7384 /* Check if the command matches any functions (this goes before bltins) */
7386 const struct function *funcp = find_function(argv[0]);
7388 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7393 /* Check if the command matches any of the builtins.
7394 * Depending on context, this might be redundant. But it's
7395 * easier to waste a few CPU cycles than it is to figure out
7396 * if this is one of those cases.
7399 /* On NOMMU, it is more expensive to re-execute shell
7400 * just in order to run echo or test builtin.
7401 * It's better to skip it here and run corresponding
7402 * non-builtin later. */
7403 const struct built_in_command *x;
7404 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7406 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7410 #if ENABLE_FEATURE_SH_STANDALONE
7411 /* Check if the command matches any busybox applets */
7413 int a = find_applet_by_name(argv[0]);
7415 # if BB_MMU /* see above why on NOMMU it is not allowed */
7416 if (APPLET_IS_NOEXEC(a)) {
7417 /* Do not leak open fds from opened script files etc.
7418 * Testcase: interactive "ls -l /proc/self/fd"
7419 * should not show tty fd open.
7421 close_saved_fds_and_FILE_fds();
7422 //FIXME: should also close saved redir fds
7423 /* Without this, "rm -i FILE" can't be ^C'ed: */
7424 switch_off_special_sigs(G.special_sig_mask);
7425 debug_printf_exec("running applet '%s'\n", argv[0]);
7426 run_noexec_applet_and_exit(a, argv[0], argv);
7429 /* Re-exec ourselves */
7430 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7431 /* Don't propagate SIG_IGN to the child */
7432 if (SPECIAL_JOBSTOP_SIGS != 0)
7433 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7434 execv(bb_busybox_exec_path, argv);
7435 /* If they called chroot or otherwise made the binary no longer
7436 * executable, fall through */
7441 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7444 execvp_or_die(argv);
7447 /* Called after [v]fork() in run_pipe
7449 static void pseudo_exec(nommu_save_t *nommu_save,
7450 struct command *command,
7451 char **argv_expanded) NORETURN;
7452 static void pseudo_exec(nommu_save_t *nommu_save,
7453 struct command *command,
7454 char **argv_expanded)
7456 if (command->argv) {
7457 pseudo_exec_argv(nommu_save, command->argv,
7458 command->assignment_cnt, argv_expanded);
7461 if (command->group) {
7462 /* Cases when we are here:
7465 * ... | ( list ) | ...
7466 * ... | { list } | ...
7470 debug_printf_exec("pseudo_exec: run_list\n");
7471 reset_traps_to_defaults();
7472 rcode = run_list(command->group);
7473 /* OK to leak memory by not calling free_pipe_list,
7474 * since this process is about to exit */
7477 re_execute_shell(&nommu_save->argv_from_re_execing,
7478 command->group_as_string,
7485 /* Case when we are here: ... | >file */
7486 debug_printf_exec("pseudo_exec'ed null command\n");
7487 _exit(EXIT_SUCCESS);
7491 static const char *get_cmdtext(struct pipe *pi)
7497 /* This is subtle. ->cmdtext is created only on first backgrounding.
7498 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7499 * On subsequent bg argv is trashed, but we won't use it */
7503 argv = pi->cmds[0].argv;
7505 pi->cmdtext = xzalloc(1);
7510 len += strlen(*argv) + 1;
7514 argv = pi->cmds[0].argv;
7516 p = stpcpy(p, *argv);
7523 static void remove_job_from_table(struct pipe *pi)
7525 struct pipe *prev_pipe;
7527 if (pi == G.job_list) {
7528 G.job_list = pi->next;
7530 prev_pipe = G.job_list;
7531 while (prev_pipe->next != pi)
7532 prev_pipe = prev_pipe->next;
7533 prev_pipe->next = pi->next;
7537 G.last_jobid = G.job_list->jobid;
7540 static void delete_finished_job(struct pipe *pi)
7542 remove_job_from_table(pi);
7546 static void clean_up_last_dead_job(void)
7548 if (G.job_list && !G.job_list->alive_cmds)
7549 delete_finished_job(G.job_list);
7552 static void insert_job_into_table(struct pipe *pi)
7554 struct pipe *job, **jobp;
7557 clean_up_last_dead_job();
7559 /* Find the end of the list, and find next job ID to use */
7562 while ((job = *jobp) != NULL) {
7569 /* Create a new job struct at the end */
7570 job = *jobp = xmemdup(pi, sizeof(*pi));
7572 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7573 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7574 for (i = 0; i < pi->num_cmds; i++) {
7575 job->cmds[i].pid = pi->cmds[i].pid;
7576 /* all other fields are not used and stay zero */
7578 job->cmdtext = xstrdup(get_cmdtext(pi));
7580 if (G_interactive_fd)
7581 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7582 G.last_jobid = job->jobid;
7586 static int job_exited_or_stopped(struct pipe *pi)
7590 if (pi->alive_cmds != pi->stopped_cmds)
7593 /* All processes in fg pipe have exited or stopped */
7597 rcode = pi->cmds[i].cmd_exitcode;
7598 /* usually last process gives overall exitstatus,
7599 * but with "set -o pipefail", last *failed* process does */
7600 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7603 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7607 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7614 dead = WIFEXITED(status) || WIFSIGNALED(status);
7617 if (WIFSTOPPED(status))
7618 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7619 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7620 if (WIFSIGNALED(status))
7621 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7622 childpid, WTERMSIG(status), WEXITSTATUS(status));
7623 if (WIFEXITED(status))
7624 debug_printf_jobs("pid %d exited, exitcode %d\n",
7625 childpid, WEXITSTATUS(status));
7627 /* Were we asked to wait for a fg pipe? */
7629 i = fg_pipe->num_cmds;
7634 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7635 if (fg_pipe->cmds[i].pid != childpid)
7639 fg_pipe->cmds[i].pid = 0;
7640 fg_pipe->alive_cmds--;
7641 ex = WEXITSTATUS(status);
7642 /* bash prints killer signal's name for *last*
7643 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7644 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7646 if (WIFSIGNALED(status)) {
7647 int sig = WTERMSIG(status);
7648 if (i == fg_pipe->num_cmds-1)
7649 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7650 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7651 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7652 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7653 * Maybe we need to use sig | 128? */
7656 fg_pipe->cmds[i].cmd_exitcode = ex;
7658 fg_pipe->stopped_cmds++;
7660 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7661 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7662 rcode = job_exited_or_stopped(fg_pipe);
7664 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7665 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7666 * and "killall -STOP cat" */
7667 if (G_interactive_fd) {
7669 if (fg_pipe->alive_cmds != 0)
7670 insert_job_into_table(fg_pipe);
7674 if (fg_pipe->alive_cmds == 0)
7677 /* There are still running processes in the fg_pipe */
7680 /* It wasn't in fg_pipe, look for process in bg pipes */
7684 /* We were asked to wait for bg or orphaned children */
7685 /* No need to remember exitcode in this case */
7686 for (pi = G.job_list; pi; pi = pi->next) {
7687 for (i = 0; i < pi->num_cmds; i++) {
7688 if (pi->cmds[i].pid == childpid)
7689 goto found_pi_and_prognum;
7692 /* Happens when shell is used as init process (init=/bin/sh) */
7693 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7694 return -1; /* this wasn't a process from fg_pipe */
7696 found_pi_and_prognum:
7699 int rcode = WEXITSTATUS(status);
7700 if (WIFSIGNALED(status))
7701 rcode = 128 + WTERMSIG(status);
7702 pi->cmds[i].cmd_exitcode = rcode;
7703 if (G.last_bg_pid == pi->cmds[i].pid)
7704 G.last_bg_pid_exitcode = rcode;
7705 pi->cmds[i].pid = 0;
7707 if (!pi->alive_cmds) {
7708 if (G_interactive_fd) {
7709 printf(JOB_STATUS_FORMAT, pi->jobid,
7710 "Done", pi->cmdtext);
7711 delete_finished_job(pi);
7714 * bash deletes finished jobs from job table only in interactive mode,
7715 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7716 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7717 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7718 * We only retain one "dead" job, if it's the single job on the list.
7719 * This covers most of real-world scenarios where this is useful.
7721 if (pi != G.job_list)
7722 delete_finished_job(pi);
7730 return -1; /* this wasn't a process from fg_pipe */
7733 /* Check to see if any processes have exited -- if they have,
7734 * figure out why and see if a job has completed.
7736 * If non-NULL fg_pipe: wait for its completion or stop.
7737 * Return its exitcode or zero if stopped.
7739 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7740 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7741 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7742 * or 0 if no children changed status.
7744 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7745 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7746 * or 0 if no children changed status.
7748 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7754 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7756 attributes = WUNTRACED;
7757 if (fg_pipe == NULL)
7758 attributes |= WNOHANG;
7761 #if ENABLE_HUSH_FAST
7762 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7763 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7764 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7765 /* There was neither fork nor SIGCHLD since last waitpid */
7766 /* Avoid doing waitpid syscall if possible */
7767 if (!G.we_have_children) {
7771 if (fg_pipe == NULL) { /* is WNOHANG set? */
7772 /* We have children, but they did not exit
7773 * or stop yet (we saw no SIGCHLD) */
7776 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7780 /* Do we do this right?
7781 * bash-3.00# sleep 20 | false
7783 * [3]+ Stopped sleep 20 | false
7784 * bash-3.00# echo $?
7785 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7786 * [hush 1.14.0: yes we do it right]
7790 #if ENABLE_HUSH_FAST
7792 i = G.count_SIGCHLD;
7794 childpid = waitpid(-1, &status, attributes);
7795 if (childpid <= 0) {
7796 if (childpid && errno != ECHILD)
7797 bb_perror_msg("waitpid");
7798 #if ENABLE_HUSH_FAST
7799 else { /* Until next SIGCHLD, waitpid's are useless */
7800 G.we_have_children = (childpid == 0);
7801 G.handled_SIGCHLD = i;
7802 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7805 /* ECHILD (no children), or 0 (no change in children status) */
7809 rcode = process_wait_result(fg_pipe, childpid, status);
7811 /* fg_pipe exited or stopped */
7814 if (childpid == waitfor_pid) {
7815 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7816 rcode = WEXITSTATUS(status);
7817 if (WIFSIGNALED(status))
7818 rcode = 128 + WTERMSIG(status);
7819 if (WIFSTOPPED(status))
7820 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7821 rcode = 128 + WSTOPSIG(status);
7823 break; /* "wait PID" called us, give it exitcode+1 */
7825 /* This wasn't one of our processes, or */
7826 /* fg_pipe still has running processes, do waitpid again */
7827 } /* while (waitpid succeeds)... */
7833 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7836 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7837 if (G_saved_tty_pgrp) {
7838 /* Job finished, move the shell to the foreground */
7839 p = getpgrp(); /* our process group id */
7840 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7841 tcsetpgrp(G_interactive_fd, p);
7847 /* Start all the jobs, but don't wait for anything to finish.
7850 * Return code is normally -1, when the caller has to wait for children
7851 * to finish to determine the exit status of the pipe. If the pipe
7852 * is a simple builtin command, however, the action is done by the
7853 * time run_pipe returns, and the exit code is provided as the
7856 * Returns -1 only if started some children. IOW: we have to
7857 * mask out retvals of builtins etc with 0xff!
7859 * The only case when we do not need to [v]fork is when the pipe
7860 * is single, non-backgrounded, non-subshell command. Examples:
7861 * cmd ; ... { list } ; ...
7862 * cmd && ... { list } && ...
7863 * cmd || ... { list } || ...
7864 * If it is, then we can run cmd as a builtin, NOFORK,
7865 * or (if SH_STANDALONE) an applet, and we can run the { list }
7866 * with run_list. If it isn't one of these, we fork and exec cmd.
7868 * Cases when we must fork:
7869 * non-single: cmd | cmd
7870 * backgrounded: cmd & { list } &
7871 * subshell: ( list ) [&]
7873 #if !ENABLE_HUSH_MODE_X
7874 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7875 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7877 static int redirect_and_varexp_helper(char ***new_env_p,
7878 struct variable **old_vars_p,
7879 struct command *command,
7880 struct squirrel **sqp,
7881 char **argv_expanded)
7883 /* setup_redirects acts on file descriptors, not FILEs.
7884 * This is perfect for work that comes after exec().
7885 * Is it really safe for inline use? Experimentally,
7886 * things seem to work. */
7887 int rcode = setup_redirects(command, sqp);
7889 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7890 *new_env_p = new_env;
7891 dump_cmd_in_x_mode(new_env);
7892 dump_cmd_in_x_mode(argv_expanded);
7894 *old_vars_p = set_vars_and_save_old(new_env);
7898 static NOINLINE int run_pipe(struct pipe *pi)
7900 static const char *const null_ptr = NULL;
7904 struct command *command;
7905 char **argv_expanded;
7907 struct squirrel *squirrel = NULL;
7910 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7913 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7914 * Result should be 3 lines: q w e, qwe, q w e
7916 G.ifs = get_local_var_value("IFS");
7920 IF_HUSH_JOB(pi->pgrp = -1;)
7921 pi->stopped_cmds = 0;
7922 command = &pi->cmds[0];
7923 argv_expanded = NULL;
7925 if (pi->num_cmds != 1
7926 || pi->followup == PIPE_BG
7927 || command->cmd_type == CMD_SUBSHELL
7934 debug_printf_exec(": group:%p argv:'%s'\n",
7935 command->group, command->argv ? command->argv[0] : "NONE");
7937 if (command->group) {
7938 #if ENABLE_HUSH_FUNCTIONS
7939 if (command->cmd_type == CMD_FUNCDEF) {
7940 /* "executing" func () { list } */
7941 struct function *funcp;
7943 funcp = new_function(command->argv[0]);
7944 /* funcp->name is already set to argv[0] */
7945 funcp->body = command->group;
7947 funcp->body_as_string = command->group_as_string;
7948 command->group_as_string = NULL;
7950 command->group = NULL;
7951 command->argv[0] = NULL;
7952 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7953 funcp->parent_cmd = command;
7954 command->child_func = funcp;
7956 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7958 return EXIT_SUCCESS;
7962 debug_printf("non-subshell group\n");
7963 rcode = 1; /* exitcode if redir failed */
7964 if (setup_redirects(command, &squirrel) == 0) {
7965 debug_printf_exec(": run_list\n");
7966 rcode = run_list(command->group) & 0xff;
7968 restore_redirects(squirrel);
7969 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7971 debug_printf_exec("run_pipe: return %d\n", rcode);
7975 argv = command->argv ? command->argv : (char **) &null_ptr;
7977 const struct built_in_command *x;
7978 #if ENABLE_HUSH_FUNCTIONS
7979 const struct function *funcp;
7983 char **new_env = NULL;
7984 struct variable *old_vars = NULL;
7986 if (argv[command->assignment_cnt] == NULL) {
7987 /* Assignments, but no command */
7988 /* Ensure redirects take effect (that is, create files).
7989 * Try "a=t >file" */
7990 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7991 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7992 /* Set shell variables */
7996 if (set_local_var(*argv, /*flag:*/ 0)) {
7997 /* assignment to readonly var / putenv error? */
8003 /* Redirect error sets $? to 1. Otherwise,
8004 * if evaluating assignment value set $?, retain it.
8005 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8007 rcode = G.last_exitcode;
8008 /* Exit, _skipping_ variable restoring code: */
8009 goto clean_up_and_ret0;
8011 #else /* Older, bigger, but more correct code */
8013 rcode = setup_redirects(command, &squirrel);
8014 restore_redirects(squirrel);
8015 /* Set shell variables */
8017 bb_putchar_stderr('+');
8019 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8021 fprintf(stderr, " %s", p);
8022 debug_printf_exec("set shell var:'%s'->'%s'\n",
8024 if (set_local_var(p, /*flag:*/ 0)) {
8025 /* assignment to readonly var / putenv error? */
8031 bb_putchar_stderr('\n');
8032 /* Redirect error sets $? to 1. Otherwise,
8033 * if evaluating assignment value set $?, retain it.
8034 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8036 rcode = G.last_exitcode;
8037 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8039 debug_printf_exec("run_pipe: return %d\n", rcode);
8044 /* Expand the rest into (possibly) many strings each */
8046 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8047 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8051 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8054 /* if someone gives us an empty string: `cmd with empty output` */
8055 if (!argv_expanded[0]) {
8056 free(argv_expanded);
8058 return G.last_exitcode;
8061 #if ENABLE_HUSH_FUNCTIONS
8062 /* Check if argv[0] matches any functions (this goes before bltins) */
8063 funcp = find_function(argv_expanded[0]);
8067 x = find_builtin(argv_expanded[0]);
8070 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8071 debug_printf("exec with redirects only\n");
8072 rcode = setup_redirects(command, NULL);
8073 /* rcode=1 can be if redir file can't be opened */
8074 goto clean_up_and_ret1;
8077 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8080 debug_printf_exec(": builtin '%s' '%s'...\n",
8081 x->b_cmd, argv_expanded[1]);
8083 rcode = x->b_function(argv_expanded) & 0xff;
8086 #if ENABLE_HUSH_FUNCTIONS
8088 # if ENABLE_HUSH_LOCAL
8089 struct variable **sv;
8090 sv = G.shadowed_vars_pp;
8091 G.shadowed_vars_pp = &old_vars;
8093 debug_printf_exec(": function '%s' '%s'...\n",
8094 funcp->name, argv_expanded[1]);
8095 rcode = run_function(funcp, argv_expanded) & 0xff;
8096 # if ENABLE_HUSH_LOCAL
8097 G.shadowed_vars_pp = sv;
8103 unset_vars(new_env);
8105 /* clean_up_and_ret0: */
8106 restore_redirects(squirrel);
8108 * Try "usleep 99999999" + ^C + "echo $?"
8109 * with FEATURE_SH_NOFORK=y.
8112 /* It was builtin or nofork.
8113 * if this would be a real fork/execed program,
8114 * it should have died if a fatal sig was received.
8115 * But OTOH, there was no separate process,
8116 * the sig was sent to _shell_, not to non-existing
8118 * Let's just handle ^C only, this one is obvious:
8119 * we aren't ok with exitcode 0 when ^C was pressed
8120 * during builtin/nofork.
8122 if (sigismember(&G.pending_set, SIGINT))
8123 rcode = 128 + SIGINT;
8126 free(argv_expanded);
8127 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8129 debug_printf_exec("run_pipe return %d\n", rcode);
8133 if (ENABLE_FEATURE_SH_NOFORK) {
8134 int n = find_applet_by_name(argv_expanded[0]);
8135 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8136 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8138 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8139 argv_expanded[0], argv_expanded[1]);
8141 * Note: signals (^C) can't interrupt here.
8142 * We remember them and they will be acted upon
8143 * after applet returns.
8144 * This makes applets which can run for a long time
8145 * and/or wait for user input ineligible for NOFORK:
8146 * for example, "yes" or "rm" (rm -i waits for input).
8148 rcode = run_nofork_applet(n, argv_expanded);
8150 goto clean_up_and_ret;
8153 /* It is neither builtin nor applet. We must fork. */
8157 /* NB: argv_expanded may already be created, and that
8158 * might include `cmd` runs! Do not rerun it! We *must*
8159 * use argv_expanded if it's non-NULL */
8161 /* Going to fork a child per each pipe member */
8166 while (cmd_no < pi->num_cmds) {
8167 struct fd_pair pipefds;
8169 volatile nommu_save_t nommu_save;
8170 nommu_save.new_env = NULL;
8171 nommu_save.old_vars = NULL;
8172 nommu_save.argv = NULL;
8173 nommu_save.argv_from_re_execing = NULL;
8175 command = &pi->cmds[cmd_no];
8177 if (command->argv) {
8178 debug_printf_exec(": pipe member '%s' '%s'...\n",
8179 command->argv[0], command->argv[1]);
8181 debug_printf_exec(": pipe member with no argv\n");
8184 /* pipes are inserted between pairs of commands */
8187 if (cmd_no < pi->num_cmds)
8188 xpiped_pair(pipefds);
8190 command->pid = BB_MMU ? fork() : vfork();
8191 if (!command->pid) { /* child */
8193 disable_restore_tty_pgrp_on_exit();
8194 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8196 /* Every child adds itself to new process group
8197 * with pgid == pid_of_first_child_in_pipe */
8198 if (G.run_list_level == 1 && G_interactive_fd) {
8201 if (pgrp < 0) /* true for 1st process only */
8203 if (setpgid(0, pgrp) == 0
8204 && pi->followup != PIPE_BG
8205 && G_saved_tty_pgrp /* we have ctty */
8207 /* We do it in *every* child, not just first,
8209 tcsetpgrp(G_interactive_fd, pgrp);
8213 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8214 /* 1st cmd in backgrounded pipe
8215 * should have its stdin /dev/null'ed */
8217 if (open(bb_dev_null, O_RDONLY))
8218 xopen("/", O_RDONLY);
8220 xmove_fd(next_infd, 0);
8222 xmove_fd(pipefds.wr, 1);
8225 /* Like bash, explicit redirects override pipes,
8226 * and the pipe fd (fd#1) is available for dup'ing:
8227 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8228 * of cmd1 goes into pipe.
8230 if (setup_redirects(command, NULL)) {
8231 /* Happens when redir file can't be opened:
8232 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8234 * hush: can't open '/qwe/rty': No such file or directory
8236 * (echo BAR is not executed, it hits _exit(1) below)
8241 /* Stores to nommu_save list of env vars putenv'ed
8242 * (NOMMU, on MMU we don't need that) */
8243 /* cast away volatility... */
8244 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8245 /* pseudo_exec() does not return */
8248 /* parent or error */
8249 #if ENABLE_HUSH_FAST
8251 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8253 enable_restore_tty_pgrp_on_exit();
8255 /* Clean up after vforked child */
8256 free(nommu_save.argv);
8257 free(nommu_save.argv_from_re_execing);
8258 unset_vars(nommu_save.new_env);
8259 add_vars(nommu_save.old_vars);
8261 free(argv_expanded);
8262 argv_expanded = NULL;
8263 if (command->pid < 0) { /* [v]fork failed */
8264 /* Clearly indicate, was it fork or vfork */
8265 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8269 /* Second and next children need to know pid of first one */
8271 pi->pgrp = command->pid;
8277 if (cmd_no < pi->num_cmds)
8279 /* Pass read (output) pipe end to next iteration */
8280 next_infd = pipefds.rd;
8283 if (!pi->alive_cmds) {
8285 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8290 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8294 /* NB: called by pseudo_exec, and therefore must not modify any
8295 * global data until exec/_exit (we can be a child after vfork!) */
8296 static int run_list(struct pipe *pi)
8298 #if ENABLE_HUSH_CASE
8299 char *case_word = NULL;
8301 #if ENABLE_HUSH_LOOPS
8302 struct pipe *loop_top = NULL;
8303 char **for_lcur = NULL;
8304 char **for_list = NULL;
8306 smallint last_followup;
8308 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8309 smalluint cond_code = 0;
8311 enum { cond_code = 0 };
8314 smallint rword; /* RES_foo */
8315 smallint last_rword; /* ditto */
8318 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8321 #if ENABLE_HUSH_LOOPS
8322 /* Check syntax for "for" */
8325 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8326 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8328 /* current word is FOR or IN (BOLD in comments below) */
8329 if (cpipe->next == NULL) {
8330 syntax_error("malformed for");
8332 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8335 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8336 if (cpipe->next->res_word == RES_DO)
8338 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8339 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8340 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8342 syntax_error("malformed for");
8344 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8351 /* Past this point, all code paths should jump to ret: label
8352 * in order to return, no direct "return" statements please.
8353 * This helps to ensure that no memory is leaked. */
8361 last_rword = RES_XXXX;
8363 last_followup = PIPE_SEQ;
8364 rcode = G.last_exitcode;
8366 /* Go through list of pipes, (maybe) executing them. */
8367 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8369 int sv_errexit_depth;
8373 if (G_flag_return_in_progress == 1)
8376 IF_HAS_KEYWORDS(rword = pi->res_word;)
8377 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8378 rword, cond_code, last_rword);
8380 sv_errexit_depth = G.errexit_depth;
8381 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8382 pi->followup != PIPE_SEQ
8386 #if ENABLE_HUSH_LOOPS
8387 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8388 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8390 /* start of a loop: remember where loop starts */
8395 /* Still in the same "if...", "then..." or "do..." branch? */
8396 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8397 if ((rcode == 0 && last_followup == PIPE_OR)
8398 || (rcode != 0 && last_followup == PIPE_AND)
8400 /* It is "<true> || CMD" or "<false> && CMD"
8401 * and we should not execute CMD */
8402 debug_printf_exec("skipped cmd because of || or &&\n");
8403 last_followup = pi->followup;
8404 goto dont_check_jobs_but_continue;
8407 last_followup = pi->followup;
8408 IF_HAS_KEYWORDS(last_rword = rword;)
8411 if (rword == RES_THEN) {
8412 /* if false; then ... fi has exitcode 0! */
8413 G.last_exitcode = rcode = EXIT_SUCCESS;
8414 /* "if <false> THEN cmd": skip cmd */
8418 if (rword == RES_ELSE || rword == RES_ELIF) {
8419 /* "if <true> then ... ELSE/ELIF cmd":
8420 * skip cmd and all following ones */
8425 #if ENABLE_HUSH_LOOPS
8426 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8428 /* first loop through for */
8430 static const char encoded_dollar_at[] ALIGN1 = {
8431 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8432 }; /* encoded representation of "$@" */
8433 static const char *const encoded_dollar_at_argv[] = {
8434 encoded_dollar_at, NULL
8435 }; /* argv list with one element: "$@" */
8438 vals = (char**)encoded_dollar_at_argv;
8439 if (pi->next->res_word == RES_IN) {
8440 /* if no variable values after "in" we skip "for" */
8441 if (!pi->next->cmds[0].argv) {
8442 G.last_exitcode = rcode = EXIT_SUCCESS;
8443 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8446 vals = pi->next->cmds[0].argv;
8447 } /* else: "for var; do..." -> assume "$@" list */
8448 /* create list of variable values */
8449 debug_print_strings("for_list made from", vals);
8450 for_list = expand_strvec_to_strvec(vals);
8451 for_lcur = for_list;
8452 debug_print_strings("for_list", for_list);
8455 /* "for" loop is over, clean up */
8461 /* Insert next value from for_lcur */
8462 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8463 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8466 if (rword == RES_IN) {
8467 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8469 if (rword == RES_DONE) {
8470 continue; /* "done" has no cmds too */
8473 #if ENABLE_HUSH_CASE
8474 if (rword == RES_CASE) {
8475 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8476 case_word = expand_strvec_to_string(pi->cmds->argv);
8477 unbackslash(case_word);
8480 if (rword == RES_MATCH) {
8483 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8484 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8486 /* all prev words didn't match, does this one match? */
8487 argv = pi->cmds->argv;
8489 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8490 /* TODO: which FNM_xxx flags to use? */
8491 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8492 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8494 if (cond_code == 0) { /* match! we will execute this branch */
8496 case_word = NULL; /* make future "word)" stop */
8503 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8504 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8506 continue; /* not matched yet, skip this pipe */
8508 if (rword == RES_ESAC) {
8509 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8511 /* "case" did not match anything: still set $? (to 0) */
8512 G.last_exitcode = rcode = EXIT_SUCCESS;
8516 /* Just pressing <enter> in shell should check for jobs.
8517 * OTOH, in non-interactive shell this is useless
8518 * and only leads to extra job checks */
8519 if (pi->num_cmds == 0) {
8520 if (G_interactive_fd)
8521 goto check_jobs_and_continue;
8525 /* After analyzing all keywords and conditions, we decided
8526 * to execute this pipe. NB: have to do checkjobs(NULL)
8527 * after run_pipe to collect any background children,
8528 * even if list execution is to be stopped. */
8529 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8530 #if ENABLE_HUSH_LOOPS
8531 G.flag_break_continue = 0;
8533 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8535 /* We ran a builtin, function, or group.
8536 * rcode is already known
8537 * and we don't need to wait for anything. */
8538 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8539 G.last_exitcode = rcode;
8540 check_and_run_traps();
8541 #if ENABLE_HUSH_LOOPS
8542 /* Was it "break" or "continue"? */
8543 if (G.flag_break_continue) {
8544 smallint fbc = G.flag_break_continue;
8545 /* We might fall into outer *loop*,
8546 * don't want to break it too */
8548 G.depth_break_continue--;
8549 if (G.depth_break_continue == 0)
8550 G.flag_break_continue = 0;
8551 /* else: e.g. "continue 2" should *break* once, *then* continue */
8552 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8553 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8554 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8557 /* "continue": simulate end of loop */
8562 if (G_flag_return_in_progress == 1) {
8563 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8566 } else if (pi->followup == PIPE_BG) {
8567 /* What does bash do with attempts to background builtins? */
8568 /* even bash 3.2 doesn't do that well with nested bg:
8569 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8570 * I'm NOT treating inner &'s as jobs */
8572 if (G.run_list_level == 1)
8573 insert_job_into_table(pi);
8575 /* Last command's pid goes to $! */
8576 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8577 G.last_bg_pid_exitcode = 0;
8578 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8579 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8580 rcode = EXIT_SUCCESS;
8584 if (G.run_list_level == 1 && G_interactive_fd) {
8585 /* Waits for completion, then fg's main shell */
8586 rcode = checkjobs_and_fg_shell(pi);
8587 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8591 /* This one just waits for completion */
8592 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8593 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8595 G.last_exitcode = rcode;
8596 check_and_run_traps();
8599 /* Handle "set -e" */
8600 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8601 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8602 if (G.errexit_depth == 0)
8605 G.errexit_depth = sv_errexit_depth;
8607 /* Analyze how result affects subsequent commands */
8609 if (rword == RES_IF || rword == RES_ELIF)
8612 check_jobs_and_continue:
8613 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8614 dont_check_jobs_but_continue: ;
8615 #if ENABLE_HUSH_LOOPS
8616 /* Beware of "while false; true; do ..."! */
8618 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8619 /* check for RES_DONE is needed for "while ...; do \n done" case */
8621 if (rword == RES_WHILE) {
8623 /* "while false; do...done" - exitcode 0 */
8624 G.last_exitcode = rcode = EXIT_SUCCESS;
8625 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8629 if (rword == RES_UNTIL) {
8631 debug_printf_exec(": until expr is true: breaking\n");
8642 #if ENABLE_HUSH_LOOPS
8647 #if ENABLE_HUSH_CASE
8651 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8655 /* Select which version we will use */
8656 static int run_and_free_list(struct pipe *pi)
8659 debug_printf_exec("run_and_free_list entered\n");
8660 if (!G.o_opt[OPT_O_NOEXEC]) {
8661 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8662 rcode = run_list(pi);
8664 /* free_pipe_list has the side effect of clearing memory.
8665 * In the long run that function can be merged with run_list,
8666 * but doing that now would hobble the debugging effort. */
8668 debug_printf_exec("run_and_free_list return %d\n", rcode);
8673 static void install_sighandlers(unsigned mask)
8675 sighandler_t old_handler;
8677 while ((mask >>= 1) != 0) {
8681 old_handler = install_sighandler(sig, pick_sighandler(sig));
8682 /* POSIX allows shell to re-enable SIGCHLD
8683 * even if it was SIG_IGN on entry.
8684 * Therefore we skip IGN check for it:
8688 /* bash re-enables SIGHUP which is SIG_IGNed on entry.
8689 * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
8691 //if (sig == SIGHUP) continue; - TODO?
8692 if (old_handler == SIG_IGN) {
8693 /* oops... restore back to IGN, and record this fact */
8694 install_sighandler(sig, old_handler);
8695 #if ENABLE_HUSH_TRAP
8697 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8699 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8705 /* Called a few times only (or even once if "sh -c") */
8706 static void install_special_sighandlers(void)
8710 /* Which signals are shell-special? */
8711 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8712 if (G_interactive_fd) {
8713 mask |= SPECIAL_INTERACTIVE_SIGS;
8714 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8715 mask |= SPECIAL_JOBSTOP_SIGS;
8717 /* Careful, do not re-install handlers we already installed */
8718 if (G.special_sig_mask != mask) {
8719 unsigned diff = mask & ~G.special_sig_mask;
8720 G.special_sig_mask = mask;
8721 install_sighandlers(diff);
8727 /* Set handlers to restore tty pgrp and exit */
8728 static void install_fatal_sighandlers(void)
8732 /* We will restore tty pgrp on these signals */
8734 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8735 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8736 + (1 << SIGBUS ) * HUSH_DEBUG
8737 + (1 << SIGSEGV) * HUSH_DEBUG
8738 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8740 /* bash 3.2 seems to handle these just like 'fatal' ones */
8743 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8744 * if we aren't interactive... but in this case
8745 * we never want to restore pgrp on exit, and this fn is not called
8747 /*+ (1 << SIGHUP )*/
8748 /*+ (1 << SIGTERM)*/
8749 /*+ (1 << SIGINT )*/
8751 G_fatal_sig_mask = mask;
8753 install_sighandlers(mask);
8757 static int set_mode(int state, char mode, const char *o_opt)
8762 G.o_opt[OPT_O_NOEXEC] = state;
8765 IF_HUSH_MODE_X(G_x_mode = state;)
8769 /* "set -+o" without parameter.
8770 * in bash, set -o produces this output:
8774 * We always use the second form.
8776 const char *p = o_opt_strings;
8779 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8785 idx = index_in_strings(o_opt_strings, o_opt);
8787 G.o_opt[idx] = state;
8791 G.o_opt[OPT_O_ERREXIT] = state;
8794 return EXIT_FAILURE;
8796 return EXIT_SUCCESS;
8799 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8800 int hush_main(int argc, char **argv)
8803 OPT_login = (1 << 0),
8807 unsigned builtin_argc;
8809 struct variable *cur_var;
8810 struct variable *shell_ver;
8813 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8814 G.last_exitcode = EXIT_SUCCESS;
8816 #if ENABLE_HUSH_FAST
8817 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8820 G.argv0_for_re_execing = argv[0];
8822 /* Deal with HUSH_VERSION */
8823 shell_ver = xzalloc(sizeof(*shell_ver));
8824 shell_ver->flg_export = 1;
8825 shell_ver->flg_read_only = 1;
8826 /* Code which handles ${var<op>...} needs writable values for all variables,
8827 * therefore we xstrdup: */
8828 shell_ver->varstr = xstrdup(hush_version_str);
8829 /* Create shell local variables from the values
8830 * currently living in the environment */
8831 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8832 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8833 G.top_var = shell_ver;
8834 cur_var = G.top_var;
8837 char *value = strchr(*e, '=');
8838 if (value) { /* paranoia */
8839 cur_var->next = xzalloc(sizeof(*cur_var));
8840 cur_var = cur_var->next;
8841 cur_var->varstr = *e;
8842 cur_var->max_len = strlen(*e);
8843 cur_var->flg_export = 1;
8847 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8848 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8849 putenv(shell_ver->varstr);
8852 set_pwd_var(SETFLAG_EXPORT);
8854 #if BASH_HOSTNAME_VAR
8855 /* Set (but not export) HOSTNAME unless already set */
8856 if (!get_local_var_value("HOSTNAME")) {
8859 set_local_var_from_halves("HOSTNAME", uts.nodename);
8861 /* bash also exports SHLVL and _,
8862 * and sets (but doesn't export) the following variables:
8864 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8865 * BASH_VERSION='3.2.0(1)-release'
8867 * MACHTYPE=i386-pc-linux-gnu
8869 * PPID=<NNNNN> - we also do it elsewhere
8880 * PIPESTATUS=([0]="0")
8881 * HISTFILE=/<xxx>/.bash_history
8885 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8887 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8898 #if ENABLE_FEATURE_EDITING
8899 G.line_input_state = new_line_input_t(FOR_SHELL);
8902 /* Initialize some more globals to non-zero values */
8903 cmdedit_update_prompt();
8905 die_func = restore_ttypgrp_and__exit;
8907 /* Shell is non-interactive at first. We need to call
8908 * install_special_sighandlers() if we are going to execute "sh <script>",
8909 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8910 * If we later decide that we are interactive, we run install_special_sighandlers()
8911 * in order to intercept (more) signals.
8915 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8916 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8919 opt = getopt(argc, argv, "+c:exinsl"
8922 # if ENABLE_HUSH_FUNCTIONS
8932 * sh ... -c 'script'
8933 * sh ... -c 'script' ARG0 [ARG1...]
8934 * On NOMMU, if builtin_argc != 0,
8935 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8936 * "" needs to be replaced with NULL
8937 * and BARGV vector fed to builtin function.
8938 * Note: the form without ARG0 never happens:
8939 * sh ... -c 'builtin' BARGV... ""
8942 G.root_pid = getpid();
8943 G.root_ppid = getppid();
8945 G.global_argv = argv + optind;
8946 G.global_argc = argc - optind;
8948 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8949 const struct built_in_command *x;
8951 install_special_sighandlers();
8952 x = find_builtin(optarg);
8953 if (x) { /* paranoia */
8954 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8955 G.global_argv += builtin_argc;
8956 G.global_argv[-1] = NULL; /* replace "" */
8958 G.last_exitcode = x->b_function(argv + optind - 1);
8962 if (!G.global_argv[0]) {
8963 /* -c 'script' (no params): prevent empty $0 */
8964 G.global_argv--; /* points to argv[i] of 'script' */
8965 G.global_argv[0] = argv[0];
8967 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8968 install_special_sighandlers();
8969 parse_and_run_string(optarg);
8972 /* Well, we cannot just declare interactiveness,
8973 * we have to have some stuff (ctty, etc) */
8974 /* G_interactive_fd++; */
8977 /* "-s" means "read from stdin", but this is how we always
8978 * operate, so simply do nothing here. */
8984 case '<': /* "big heredoc" support */
8985 full_write1_str(optarg);
8988 unsigned long long empty_trap_mask;
8990 G.root_pid = bb_strtou(optarg, &optarg, 16);
8992 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8994 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8996 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8998 builtin_argc = bb_strtou(optarg, &optarg, 16);
9000 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
9001 if (empty_trap_mask != 0) {
9002 IF_HUSH_TRAP(int sig;)
9003 install_special_sighandlers();
9004 # if ENABLE_HUSH_TRAP
9005 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9006 for (sig = 1; sig < NSIG; sig++) {
9007 if (empty_trap_mask & (1LL << sig)) {
9008 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
9009 install_sighandler(sig, SIG_IGN);
9014 # if ENABLE_HUSH_LOOPS
9016 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
9022 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
9024 # if ENABLE_HUSH_FUNCTIONS
9026 struct function *funcp = new_function(optarg);
9027 /* funcp->name is already set to optarg */
9028 /* funcp->body is set to NULL. It's a special case. */
9029 funcp->body_as_string = argv[optind];
9038 if (set_mode(1, opt, NULL) == 0) /* no error */
9042 fprintf(stderr, "Usage: sh [FILE]...\n"
9043 " or: sh -c command [args]...\n\n");
9049 } /* option parsing loop */
9051 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9052 G.global_argc = argc - (optind - 1);
9053 G.global_argv = argv + (optind - 1);
9054 G.global_argv[0] = argv[0];
9057 G.root_pid = getpid();
9058 G.root_ppid = getppid();
9061 /* If we are login shell... */
9062 if (flags & OPT_login) {
9064 debug_printf("sourcing /etc/profile\n");
9065 input = fopen_for_read("/etc/profile");
9066 if (input != NULL) {
9067 remember_FILE(input);
9068 install_special_sighandlers();
9069 parse_and_run_file(input);
9070 fclose_and_forget(input);
9072 /* bash: after sourcing /etc/profile,
9073 * tries to source (in the given order):
9074 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9075 * stopping on first found. --noprofile turns this off.
9076 * bash also sources ~/.bash_logout on exit.
9077 * If called as sh, skips .bash_XXX files.
9081 if (G.global_argv[1]) {
9084 * "bash <script>" (which is never interactive (unless -i?))
9085 * sources $BASH_ENV here (without scanning $PATH).
9086 * If called as sh, does the same but with $ENV.
9087 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9091 debug_printf("running script '%s'\n", G.global_argv[0]);
9092 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9093 input = xfopen_for_read(G.global_argv[0]);
9094 xfunc_error_retval = 1;
9095 remember_FILE(input);
9096 install_special_sighandlers();
9097 parse_and_run_file(input);
9098 #if ENABLE_FEATURE_CLEAN_UP
9099 fclose_and_forget(input);
9104 /* Up to here, shell was non-interactive. Now it may become one.
9105 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9108 /* A shell is interactive if the '-i' flag was given,
9109 * or if all of the following conditions are met:
9111 * no arguments remaining or the -s flag given
9112 * standard input is a terminal
9113 * standard output is a terminal
9114 * Refer to Posix.2, the description of the 'sh' utility.
9117 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9118 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9119 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9120 if (G_saved_tty_pgrp < 0)
9121 G_saved_tty_pgrp = 0;
9123 /* try to dup stdin to high fd#, >= 255 */
9124 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9125 if (G_interactive_fd < 0) {
9126 /* try to dup to any fd */
9127 G_interactive_fd = dup(STDIN_FILENO);
9128 if (G_interactive_fd < 0) {
9130 G_interactive_fd = 0;
9131 G_saved_tty_pgrp = 0;
9134 // TODO: track & disallow any attempts of user
9135 // to (inadvertently) close/redirect G_interactive_fd
9137 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9138 if (G_interactive_fd) {
9139 close_on_exec_on(G_interactive_fd);
9141 if (G_saved_tty_pgrp) {
9142 /* If we were run as 'hush &', sleep until we are
9143 * in the foreground (tty pgrp == our pgrp).
9144 * If we get started under a job aware app (like bash),
9145 * make sure we are now in charge so we don't fight over
9146 * who gets the foreground */
9148 pid_t shell_pgrp = getpgrp();
9149 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9150 if (G_saved_tty_pgrp == shell_pgrp)
9152 /* send TTIN to ourself (should stop us) */
9153 kill(- shell_pgrp, SIGTTIN);
9157 /* Install more signal handlers */
9158 install_special_sighandlers();
9160 if (G_saved_tty_pgrp) {
9161 /* Set other signals to restore saved_tty_pgrp */
9162 install_fatal_sighandlers();
9163 /* Put ourselves in our own process group
9164 * (bash, too, does this only if ctty is available) */
9165 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9166 /* Grab control of the terminal */
9167 tcsetpgrp(G_interactive_fd, getpid());
9169 enable_restore_tty_pgrp_on_exit();
9171 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9173 const char *hp = get_local_var_value("HISTFILE");
9175 hp = get_local_var_value("HOME");
9177 hp = concat_path_file(hp, ".hush_history");
9182 G.line_input_state->hist_file = hp;
9183 //set_local_var(xasprintf("HISTFILE=%s", ...));
9185 # if ENABLE_FEATURE_SH_HISTFILESIZE
9186 hp = get_local_var_value("HISTFILESIZE");
9187 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9192 install_special_sighandlers();
9194 #elif ENABLE_HUSH_INTERACTIVE
9195 /* No job control compiled in, only prompt/line editing */
9196 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9197 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9198 if (G_interactive_fd < 0) {
9199 /* try to dup to any fd */
9200 G_interactive_fd = dup(STDIN_FILENO);
9201 if (G_interactive_fd < 0)
9203 G_interactive_fd = 0;
9206 if (G_interactive_fd) {
9207 close_on_exec_on(G_interactive_fd);
9209 install_special_sighandlers();
9211 /* We have interactiveness code disabled */
9212 install_special_sighandlers();
9215 * if interactive but not a login shell, sources ~/.bashrc
9216 * (--norc turns this off, --rcfile <file> overrides)
9219 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9220 /* note: ash and hush share this string */
9221 printf("\n\n%s %s\n"
9222 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9225 "hush - the humble shell"
9229 parse_and_run_file(stdin);
9232 hush_exit(G.last_exitcode);
9239 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9244 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9245 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9247 int argc = string_array_len(argv);
9248 return applet_main_func(argc, argv);
9251 #if ENABLE_HUSH_TEST || BASH_TEST2
9252 static int FAST_FUNC builtin_test(char **argv)
9254 return run_applet_main(argv, test_main);
9257 #if ENABLE_HUSH_ECHO
9258 static int FAST_FUNC builtin_echo(char **argv)
9260 return run_applet_main(argv, echo_main);
9263 #if ENABLE_HUSH_PRINTF
9264 static int FAST_FUNC builtin_printf(char **argv)
9266 return run_applet_main(argv, printf_main);
9270 #if ENABLE_HUSH_HELP
9271 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9273 const struct built_in_command *x;
9276 "Built-in commands:\n"
9277 "------------------\n");
9278 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9280 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9282 return EXIT_SUCCESS;
9286 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9287 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9289 show_history(G.line_input_state);
9290 return EXIT_SUCCESS;
9294 static char **skip_dash_dash(char **argv)
9297 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9302 static int FAST_FUNC builtin_cd(char **argv)
9306 argv = skip_dash_dash(argv);
9308 if (newdir == NULL) {
9309 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9310 * bash says "bash: cd: HOME not set" and does nothing
9313 const char *home = get_local_var_value("HOME");
9314 newdir = home ? home : "/";
9316 if (chdir(newdir)) {
9317 /* Mimic bash message exactly */
9318 bb_perror_msg("cd: %s", newdir);
9319 return EXIT_FAILURE;
9321 /* Read current dir (get_cwd(1) is inside) and set PWD.
9322 * Note: do not enforce exporting. If PWD was unset or unexported,
9323 * set it again, but do not export. bash does the same.
9325 set_pwd_var(/*flag:*/ 0);
9326 return EXIT_SUCCESS;
9329 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9332 return EXIT_SUCCESS;
9335 static int FAST_FUNC builtin_eval(char **argv)
9337 int rcode = EXIT_SUCCESS;
9339 argv = skip_dash_dash(argv);
9341 char *str = expand_strvec_to_string(argv);
9343 * eval "echo Hi; done" ("done" is syntax error):
9344 * "echo Hi" will not execute too.
9346 parse_and_run_string(str);
9348 rcode = G.last_exitcode;
9353 static int FAST_FUNC builtin_exec(char **argv)
9355 argv = skip_dash_dash(argv);
9356 if (argv[0] == NULL)
9357 return EXIT_SUCCESS; /* bash does this */
9359 /* Careful: we can end up here after [v]fork. Do not restore
9360 * tty pgrp then, only top-level shell process does that */
9361 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9362 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9364 /* Saved-redirect fds, script fds and G_interactive_fd are still
9365 * open here. However, they are all CLOEXEC, and execv below
9366 * closes them. Try interactive "exec ls -l /proc/self/fd",
9367 * it should show no extra open fds in the "ls" process.
9368 * If we'd try to run builtins/NOEXECs, this would need improving.
9370 //close_saved_fds_and_FILE_fds();
9372 /* TODO: if exec fails, bash does NOT exit! We do.
9373 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9374 * and tcsetpgrp, and this is inherently racy.
9376 execvp_or_die(argv);
9379 static int FAST_FUNC builtin_exit(char **argv)
9381 debug_printf_exec("%s()\n", __func__);
9383 /* interactive bash:
9384 * # trap "echo EEE" EXIT
9387 * There are stopped jobs.
9388 * (if there are _stopped_ jobs, running ones don't count)
9391 * EEE (then bash exits)
9393 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9396 /* note: EXIT trap is run by hush_exit */
9397 argv = skip_dash_dash(argv);
9398 if (argv[0] == NULL)
9399 hush_exit(G.last_exitcode);
9400 /* mimic bash: exit 123abc == exit 255 + error msg */
9401 xfunc_error_retval = 255;
9402 /* bash: exit -2 == exit 254, no error msg */
9403 hush_exit(xatoi(argv[0]) & 0xff);
9406 #if ENABLE_HUSH_TYPE
9407 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9408 static int FAST_FUNC builtin_type(char **argv)
9410 int ret = EXIT_SUCCESS;
9416 if (0) {} /* make conditional compile easier below */
9417 /*else if (find_alias(*argv))
9418 type = "an alias";*/
9419 #if ENABLE_HUSH_FUNCTIONS
9420 else if (find_function(*argv))
9421 type = "a function";
9423 else if (find_builtin(*argv))
9424 type = "a shell builtin";
9425 else if ((path = find_in_path(*argv)) != NULL)
9428 bb_error_msg("type: %s: not found", *argv);
9433 printf("%s is %s\n", *argv, type);
9441 #if ENABLE_HUSH_READ
9442 /* Interruptibility of read builtin in bash
9443 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9445 * Empty trap makes read ignore corresponding signal, for any signal.
9448 * - terminates non-interactive shell;
9449 * - interrupts read in interactive shell;
9450 * if it has non-empty trap:
9451 * - executes trap and returns to command prompt in interactive shell;
9452 * - executes trap and returns to read in non-interactive shell;
9454 * - is ignored (does not interrupt) read in interactive shell;
9455 * - terminates non-interactive shell;
9456 * if it has non-empty trap:
9457 * - executes trap and returns to read;
9459 * - terminates shell (regardless of interactivity);
9460 * if it has non-empty trap:
9461 * - executes trap and returns to read;
9462 * SIGCHLD from children:
9463 * - does not interrupt read regardless of interactivity:
9464 * try: sleep 1 & read x; echo $x
9466 static int FAST_FUNC builtin_read(char **argv)
9473 char *opt_d = NULL; /* optimized out if !BASH */
9477 /* "!": do not abort on errors.
9478 * Option string must start with "sr" to match BUILTIN_READ_xxx
9480 read_flags = getopt32(argv,
9482 "!srn:p:t:u:d:", &opt_n, &opt_p, &opt_t, &opt_u, &opt_d
9484 "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u
9487 if (read_flags == (uint32_t)-1)
9488 return EXIT_FAILURE;
9490 ifs = get_local_var_value("IFS"); /* can be NULL */
9493 r = shell_builtin_read(set_local_var_from_halves,
9504 if ((uintptr_t)r == 1 && errno == EINTR) {
9505 unsigned sig = check_and_run_traps();
9510 if ((uintptr_t)r > 1) {
9511 bb_error_msg("%s", r);
9512 r = (char*)(uintptr_t)1;
9515 return (uintptr_t)r;
9519 #if ENABLE_HUSH_UMASK
9520 static int FAST_FUNC builtin_umask(char **argv)
9527 argv = skip_dash_dash(argv);
9529 mode_t old_mask = mask;
9531 /* numeric umasks are taken as-is */
9532 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9533 if (!isdigit(argv[0][0]))
9535 mask = bb_parse_mode(argv[0], mask);
9536 if (!isdigit(argv[0][0]))
9538 if ((unsigned)mask > 0777) {
9541 * bash: umask: 'q': invalid symbolic mode operator
9542 * bash: umask: 999: octal number out of range
9544 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9549 printf("%04o\n", (unsigned) mask);
9550 /* fall through and restore mask which we set to 0 */
9554 return !rc; /* rc != 0 - success */
9558 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9559 static void print_escaped(const char *s)
9564 const char *p = strchrnul(s, '\'');
9565 /* print 'xxxx', possibly just '' */
9566 printf("'%.*s'", (int)(p - s), s);
9571 /* s points to '; print "'''...'''" */
9573 do putchar('\''); while (*++s == '\'');
9579 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9580 static int helper_export_local(char **argv, unsigned flags)
9584 char *name_end = strchrnul(name, '=');
9586 /* So far we do not check that name is valid (TODO?) */
9588 if (*name_end == '\0') {
9589 struct variable *var, **vpp;
9591 vpp = get_ptr_to_local_var(name, name_end - name);
9592 var = vpp ? *vpp : NULL;
9594 if (flags & SETFLAG_UNEXPORT) {
9595 /* export -n NAME (without =VALUE) */
9597 var->flg_export = 0;
9598 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9600 } /* else: export -n NOT_EXISTING_VAR: no-op */
9603 if (flags & SETFLAG_EXPORT) {
9604 /* export NAME (without =VALUE) */
9606 var->flg_export = 1;
9607 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9608 putenv(var->varstr);
9612 if (flags & SETFLAG_MAKE_RO) {
9613 /* readonly NAME (without =VALUE) */
9615 var->flg_read_only = 1;
9619 # if ENABLE_HUSH_LOCAL
9620 /* Is this "local" bltin? */
9621 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9622 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9623 if (var && var->func_nest_level == lvl) {
9624 /* "local x=abc; ...; local x" - ignore second local decl */
9629 /* Exporting non-existing variable.
9630 * bash does not put it in environment,
9631 * but remembers that it is exported,
9632 * and does put it in env when it is set later.
9633 * We just set it to "" and export.
9635 /* Or, it's "local NAME" (without =VALUE).
9636 * bash sets the value to "".
9638 /* Or, it's "readonly NAME" (without =VALUE).
9639 * bash remembers NAME and disallows its creation
9642 name = xasprintf("%s=", name);
9644 /* (Un)exporting/making local NAME=VALUE */
9645 name = xstrdup(name);
9647 if (set_local_var(name, flags))
9648 return EXIT_FAILURE;
9650 return EXIT_SUCCESS;
9654 #if ENABLE_HUSH_EXPORT
9655 static int FAST_FUNC builtin_export(char **argv)
9657 unsigned opt_unexport;
9659 #if ENABLE_HUSH_EXPORT_N
9660 /* "!": do not abort on errors */
9661 opt_unexport = getopt32(argv, "!n");
9662 if (opt_unexport == (uint32_t)-1)
9663 return EXIT_FAILURE;
9670 if (argv[0] == NULL) {
9677 /* ash emits: export VAR='VAL'
9678 * bash: declare -x VAR="VAL"
9679 * we follow ash example */
9680 const char *s = *e++;
9681 const char *p = strchr(s, '=');
9683 if (!p) /* wtf? take next variable */
9686 printf("export %.*s", (int)(p - s) + 1, s);
9687 print_escaped(p + 1);
9691 /*fflush_all(); - done after each builtin anyway */
9693 return EXIT_SUCCESS;
9696 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9700 #if ENABLE_HUSH_LOCAL
9701 static int FAST_FUNC builtin_local(char **argv)
9703 if (G.func_nest_level == 0) {
9704 bb_error_msg("%s: not in a function", argv[0]);
9705 return EXIT_FAILURE; /* bash compat */
9708 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9712 #if ENABLE_HUSH_READONLY
9713 static int FAST_FUNC builtin_readonly(char **argv)
9716 if (*argv == NULL) {
9717 /* bash: readonly [-p]: list all readonly VARs
9718 * (-p has no effect in bash)
9721 for (e = G.top_var; e; e = e->next) {
9722 if (e->flg_read_only) {
9723 //TODO: quote value: readonly VAR='VAL'
9724 printf("readonly %s\n", e->varstr);
9727 return EXIT_SUCCESS;
9729 return helper_export_local(argv, SETFLAG_MAKE_RO);
9733 #if ENABLE_HUSH_UNSET
9734 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9735 static int FAST_FUNC builtin_unset(char **argv)
9740 /* "!": do not abort on errors */
9741 /* "+": stop at 1st non-option */
9742 opts = getopt32(argv, "!+vf");
9743 if (opts == (unsigned)-1)
9744 return EXIT_FAILURE;
9746 bb_error_msg("unset: -v and -f are exclusive");
9747 return EXIT_FAILURE;
9753 if (!(opts & 2)) { /* not -f */
9754 if (unset_local_var(*argv)) {
9755 /* unset <nonexistent_var> doesn't fail.
9756 * Error is when one tries to unset RO var.
9757 * Message was printed by unset_local_var. */
9761 # if ENABLE_HUSH_FUNCTIONS
9773 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9774 * built-in 'set' handler
9776 * set [-abCefhmnuvx] [-o option] [argument...]
9777 * set [+abCefhmnuvx] [+o option] [argument...]
9778 * set -- [argument...]
9781 * Implementations shall support the options in both their hyphen and
9782 * plus-sign forms. These options can also be specified as options to sh.
9784 * Write out all variables and their values: set
9785 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9786 * Turn on the -x and -v options: set -xv
9787 * Unset all positional parameters: set --
9788 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9789 * Set the positional parameters to the expansion of x, even if x expands
9790 * with a leading '-' or '+': set -- $x
9792 * So far, we only support "set -- [argument...]" and some of the short names.
9794 static int FAST_FUNC builtin_set(char **argv)
9797 char **pp, **g_argv;
9798 char *arg = *++argv;
9802 for (e = G.top_var; e; e = e->next)
9804 return EXIT_SUCCESS;
9808 if (strcmp(arg, "--") == 0) {
9812 if (arg[0] != '+' && arg[0] != '-')
9814 for (n = 1; arg[n]; ++n) {
9815 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9817 if (arg[n] == 'o' && argv[1])
9820 } while ((arg = *++argv) != NULL);
9821 /* Now argv[0] is 1st argument */
9824 return EXIT_SUCCESS;
9827 /* NB: G.global_argv[0] ($0) is never freed/changed */
9828 g_argv = G.global_argv;
9829 if (G.global_args_malloced) {
9835 G.global_args_malloced = 1;
9836 pp = xzalloc(sizeof(pp[0]) * 2);
9837 pp[0] = g_argv[0]; /* retain $0 */
9840 /* This realloc's G.global_argv */
9841 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9843 G.global_argc = 1 + string_array_len(pp + 1);
9845 return EXIT_SUCCESS;
9847 /* Nothing known, so abort */
9849 bb_error_msg("set: %s: invalid option", arg);
9850 return EXIT_FAILURE;
9854 static int FAST_FUNC builtin_shift(char **argv)
9857 argv = skip_dash_dash(argv);
9859 n = bb_strtou(argv[0], NULL, 10);
9860 if (errno || n < 0) {
9861 /* shared string with ash.c */
9862 bb_error_msg("Illegal number: %s", argv[0]);
9864 * ash aborts in this case.
9865 * bash prints error message and set $? to 1.
9866 * Interestingly, for "shift 99999" bash does not
9867 * print error message, but does set $? to 1
9868 * (and does no shifting at all).
9872 if (n >= 0 && n < G.global_argc) {
9873 if (G_global_args_malloced) {
9876 free(G.global_argv[m++]);
9879 memmove(&G.global_argv[1], &G.global_argv[n+1],
9880 G.global_argc * sizeof(G.global_argv[0]));
9881 return EXIT_SUCCESS;
9883 return EXIT_FAILURE;
9886 #if ENABLE_HUSH_GETOPTS
9887 static int FAST_FUNC builtin_getopts(char **argv)
9889 /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
9892 If a required argument is not found, and getopts is not silent,
9893 a question mark (?) is placed in VAR, OPTARG is unset, and a
9894 diagnostic message is printed. If getopts is silent, then a
9895 colon (:) is placed in VAR and OPTARG is set to the option
9898 Test that VAR is a valid variable name?
9900 "Whenever the shell is invoked, OPTIND shall be initialized to 1"
9903 const char *cp, *optstring, *var;
9904 int c, n, exitcode, my_opterr;
9907 optstring = *++argv;
9908 if (!optstring || !(var = *++argv)) {
9909 bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
9910 return EXIT_FAILURE;
9914 argv[0] = G.global_argv[0]; /* for error messages in getopt() */
9916 argv = G.global_argv;
9920 if (optstring[0] != ':') {
9921 cp = get_local_var_value("OPTERR");
9922 /* 0 if "OPTERR=0", 1 otherwise */
9923 my_opterr = (!cp || NOT_LONE_CHAR(cp, '0'));
9926 /* getopts stops on first non-option. Add "+" to force that */
9927 /*if (optstring[0] != '+')*/ {
9928 char *s = alloca(strlen(optstring) + 2);
9929 sprintf(s, "+%s", optstring);
9933 /* Naively, now we should just
9934 * cp = get_local_var_value("OPTIND");
9935 * optind = cp ? atoi(cp) : 0;
9937 * opterr = my_opterr;
9938 * c = getopt(string_array_len(argv), argv, optstring);
9939 * and be done? Not so fast...
9940 * Unlike normal getopt() usage in C programs, here
9941 * each successive call will (usually) have the same argv[] CONTENTS,
9942 * but not the ADDRESSES. Worse yet, it's possible that between
9943 * invocations of "getopts", there will be calls to shell builtins
9944 * which use getopt() internally. Example:
9945 * while getopts "abc" RES -a -bc -abc de; do
9948 * This would not work correctly: getopt() call inside "unset"
9949 * modifies internal libc state which is tracking position in
9950 * multi-option strings ("-abc"). At best, it can skip options
9951 * or return the same option infinitely. With glibc implementation
9952 * of getopt(), it would use outright invalid pointers and return
9953 * garbage even _without_ "unset" mangling internal state.
9955 * We resort to resetting getopt() state and calling it N times,
9956 * until we get Nth result (or failure).
9957 * (N == G.getopt_count is reset to 0 whenever OPTIND is [un]set).
9959 optind = 0; /* reset getopt() state */
9961 n = string_array_len(argv);
9964 opterr = (count < G.getopt_count) ? 0 : my_opterr;
9965 c = getopt(n, argv, optstring);
9969 } while (count <= G.getopt_count);
9971 /* Set OPTIND. Prevent resetting of the magic counter! */
9972 set_local_var_from_halves("OPTIND", utoa(optind));
9973 G.getopt_count = count; /* "next time, give me N+1'th result" */
9976 /* Always set or unset, never left as-is, even on exit/error:
9977 * "If no option was found, or if the option that was found
9978 * does not have an option-argument, OPTARG shall be unset."
9982 /* If ":optstring" and unknown option is seen,
9983 * it is stored to OPTARG.
9985 if (optstring[1] == ':') {
9991 set_local_var_from_halves("OPTARG", cp);
9993 unset_local_var("OPTARG");
9995 /* Convert -1 to "?" */
9996 exitcode = EXIT_SUCCESS;
9997 if (c < 0) { /* -1: end of options */
9998 exitcode = EXIT_FAILURE;
10004 set_local_var_from_halves(var, cbuf);
10010 static int FAST_FUNC builtin_source(char **argv)
10012 char *arg_path, *filename;
10015 char *args_need_save;
10016 #if ENABLE_HUSH_FUNCTIONS
10020 argv = skip_dash_dash(argv);
10021 filename = argv[0];
10023 /* bash says: "bash: .: filename argument required" */
10024 return 2; /* bash compat */
10027 if (!strchr(filename, '/')) {
10028 arg_path = find_in_path(filename);
10030 filename = arg_path;
10032 input = remember_FILE(fopen_or_warn(filename, "r"));
10035 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
10036 /* POSIX: non-interactive shell should abort here,
10037 * not merely fail. So far no one complained :)
10039 return EXIT_FAILURE;
10042 #if ENABLE_HUSH_FUNCTIONS
10043 sv_flg = G_flag_return_in_progress;
10044 /* "we are inside sourced file, ok to use return" */
10045 G_flag_return_in_progress = -1;
10047 args_need_save = argv[1]; /* used as a boolean variable */
10048 if (args_need_save)
10049 save_and_replace_G_args(&sv, argv);
10051 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
10052 G.last_exitcode = 0;
10053 parse_and_run_file(input);
10054 fclose_and_forget(input);
10056 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
10057 restore_G_args(&sv, argv);
10058 #if ENABLE_HUSH_FUNCTIONS
10059 G_flag_return_in_progress = sv_flg;
10062 return G.last_exitcode;
10065 #if ENABLE_HUSH_TRAP
10066 static int FAST_FUNC builtin_trap(char **argv)
10072 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
10077 /* No args: print all trapped */
10078 for (i = 0; i < NSIG; ++i) {
10080 printf("trap -- ");
10081 print_escaped(G_traps[i]);
10082 /* note: bash adds "SIG", but only if invoked
10083 * as "bash". If called as "sh", or if set -o posix,
10084 * then it prints short signal names.
10085 * We are printing short names: */
10086 printf(" %s\n", get_signame(i));
10089 /*fflush_all(); - done after each builtin anyway */
10090 return EXIT_SUCCESS;
10094 /* If first arg is a number: reset all specified signals */
10095 sig = bb_strtou(*argv, NULL, 10);
10099 ret = EXIT_SUCCESS;
10101 sighandler_t handler;
10103 sig = get_signum(*argv++);
10105 ret = EXIT_FAILURE;
10106 /* Mimic bash message exactly */
10107 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
10111 free(G_traps[sig]);
10112 G_traps[sig] = xstrdup(new_cmd);
10114 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
10115 get_signame(sig), sig, G_traps[sig]);
10117 /* There is no signal for 0 (EXIT) */
10122 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
10124 /* We are removing trap handler */
10125 handler = pick_sighandler(sig);
10126 install_sighandler(sig, handler);
10131 if (!argv[1]) { /* no second arg */
10132 bb_error_msg("trap: invalid arguments");
10133 return EXIT_FAILURE;
10136 /* First arg is "-": reset all specified to default */
10137 /* First arg is "--": skip it, the rest is "handler SIGs..." */
10138 /* Everything else: set arg as signal handler
10139 * (includes "" case, which ignores signal) */
10140 if (argv[0][0] == '-') {
10141 if (argv[0][1] == '\0') { /* "-" */
10142 /* new_cmd remains NULL: "reset these sigs" */
10145 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
10148 /* else: "-something", no special meaning */
10153 goto process_sig_list;
10157 #if ENABLE_HUSH_JOB
10158 static struct pipe *parse_jobspec(const char *str)
10163 if (sscanf(str, "%%%u", &jobnum) != 1) {
10165 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
10167 bb_error_msg("bad argument '%s'", str);
10170 /* It is "%%", "%+" or "%" - current job */
10171 jobnum = G.last_jobid;
10173 bb_error_msg("no current job");
10177 for (pi = G.job_list; pi; pi = pi->next) {
10178 if (pi->jobid == jobnum) {
10182 bb_error_msg("%u: no such job", jobnum);
10186 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10189 const char *status_string;
10191 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10192 for (job = G.job_list; job; job = job->next) {
10193 if (job->alive_cmds == job->stopped_cmds)
10194 status_string = "Stopped";
10196 status_string = "Running";
10198 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10201 clean_up_last_dead_job();
10203 return EXIT_SUCCESS;
10206 /* built-in 'fg' and 'bg' handler */
10207 static int FAST_FUNC builtin_fg_bg(char **argv)
10212 if (!G_interactive_fd)
10213 return EXIT_FAILURE;
10215 /* If they gave us no args, assume they want the last backgrounded task */
10217 for (pi = G.job_list; pi; pi = pi->next) {
10218 if (pi->jobid == G.last_jobid) {
10222 bb_error_msg("%s: no current job", argv[0]);
10223 return EXIT_FAILURE;
10226 pi = parse_jobspec(argv[1]);
10228 return EXIT_FAILURE;
10230 /* TODO: bash prints a string representation
10231 * of job being foregrounded (like "sleep 1 | cat") */
10232 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10233 /* Put the job into the foreground. */
10234 tcsetpgrp(G_interactive_fd, pi->pgrp);
10237 /* Restart the processes in the job */
10238 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10239 for (i = 0; i < pi->num_cmds; i++) {
10240 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10242 pi->stopped_cmds = 0;
10244 i = kill(- pi->pgrp, SIGCONT);
10246 if (errno == ESRCH) {
10247 delete_finished_job(pi);
10248 return EXIT_SUCCESS;
10250 bb_perror_msg("kill (SIGCONT)");
10253 if (argv[0][0] == 'f') {
10254 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10255 return checkjobs_and_fg_shell(pi);
10257 return EXIT_SUCCESS;
10261 #if ENABLE_HUSH_KILL
10262 static int FAST_FUNC builtin_kill(char **argv)
10266 # if ENABLE_HUSH_JOB
10267 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10275 if (argv[i][0] != '%')
10278 * "kill %N" - job kill
10279 * Converting to pgrp / pid kill
10281 pi = parse_jobspec(argv[i]);
10283 /* Eat bad jobspec */
10287 argv[j - 1] = argv[j];
10294 * In jobs started under job control, we signal
10295 * entire process group by kill -PGRP_ID.
10296 * This happens, f.e., in interactive shell.
10298 * Otherwise, we signal each child via
10299 * kill PID1 PID2 PID3.
10301 * sh -c 'sleep 1|sleep 1 & kill %1'
10302 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10303 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10305 n = G_interactive_fd ? 1 : pi->num_cmds;
10306 dst = alloca(n * sizeof(int)*4);
10308 if (G_interactive_fd)
10309 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10310 else for (j = 0; j < n; j++) {
10311 struct command *cmd = &pi->cmds[j];
10312 /* Skip exited members of the job */
10316 * kill_main has matching code to expect
10317 * leading space. Needed to not confuse
10318 * negative pids with "kill -SIGNAL_NO" syntax
10320 dst += sprintf(dst, " %u", (int)cmd->pid);
10323 } while (argv[++i]);
10327 if (argv[1] || ret == 0) {
10328 ret = run_applet_main(argv, kill_main);
10330 /* else: ret = 1, "kill %bad_jobspec" case */
10335 #if ENABLE_HUSH_WAIT
10336 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10337 #if !ENABLE_HUSH_JOB
10338 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10340 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10347 if (!sigisemptyset(&G.pending_set))
10350 /* waitpid is not interruptible by SA_RESTARTed
10351 * signals which we use. Thus, this ugly dance:
10354 /* Make sure possible SIGCHLD is stored in kernel's
10355 * pending signal mask before we call waitpid.
10356 * Or else we may race with SIGCHLD, lose it,
10357 * and get stuck in sigsuspend...
10359 sigfillset(&oldset); /* block all signals, remember old set */
10360 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10362 if (!sigisemptyset(&G.pending_set)) {
10363 /* Crap! we raced with some signal! */
10367 /*errno = 0; - checkjobs does this */
10368 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10369 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10370 debug_printf_exec("checkjobs:%d\n", ret);
10371 #if ENABLE_HUSH_JOB
10372 if (waitfor_pipe) {
10373 int rcode = job_exited_or_stopped(waitfor_pipe);
10374 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10377 sigprocmask(SIG_SETMASK, &oldset, NULL);
10382 /* if ECHILD, there are no children (ret is -1 or 0) */
10383 /* if ret == 0, no children changed state */
10384 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10385 if (errno == ECHILD || ret) {
10387 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10389 sigprocmask(SIG_SETMASK, &oldset, NULL);
10392 /* Wait for SIGCHLD or any other signal */
10393 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10394 /* Note: sigsuspend invokes signal handler */
10395 sigsuspend(&oldset);
10397 sigprocmask(SIG_SETMASK, &oldset, NULL);
10399 /* So, did we get a signal? */
10400 sig = check_and_run_traps();
10401 if (sig /*&& sig != SIGCHLD - always true */) {
10402 /* Do this for any (non-ignored) signal, not only for ^C */
10406 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10411 static int FAST_FUNC builtin_wait(char **argv)
10416 argv = skip_dash_dash(argv);
10417 if (argv[0] == NULL) {
10418 /* Don't care about wait results */
10419 /* Note 1: must wait until there are no more children */
10420 /* Note 2: must be interruptible */
10422 * $ sleep 3 & sleep 6 & wait
10423 * [1] 30934 sleep 3
10424 * [2] 30935 sleep 6
10427 * $ sleep 3 & sleep 6 & wait
10428 * [1] 30936 sleep 3
10429 * [2] 30937 sleep 6
10431 * ^C <-- after ~4 sec from keyboard
10434 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10438 pid_t pid = bb_strtou(*argv, NULL, 10);
10439 if (errno || pid <= 0) {
10440 #if ENABLE_HUSH_JOB
10441 if (argv[0][0] == '%') {
10442 struct pipe *wait_pipe;
10443 ret = 127; /* bash compat for bad jobspecs */
10444 wait_pipe = parse_jobspec(*argv);
10446 ret = job_exited_or_stopped(wait_pipe);
10448 ret = wait_for_child_or_signal(wait_pipe, 0);
10450 /* waiting on "last dead job" removes it */
10451 clean_up_last_dead_job();
10454 /* else: parse_jobspec() already emitted error msg */
10458 /* mimic bash message */
10459 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10460 ret = EXIT_FAILURE;
10461 continue; /* bash checks all argv[] */
10464 /* Do we have such child? */
10465 ret = waitpid(pid, &status, WNOHANG);
10469 if (errno == ECHILD) {
10470 if (pid == G.last_bg_pid) {
10471 /* "wait $!" but last bg task has already exited. Try:
10472 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10473 * In bash it prints exitcode 0, then 3.
10474 * In dash, it is 127.
10476 ret = G.last_bg_pid_exitcode;
10478 /* Example: "wait 1". mimic bash message */
10479 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10483 bb_perror_msg("wait %s", *argv);
10485 continue; /* bash checks all argv[] */
10488 /* Yes, and it still runs */
10489 ret = wait_for_child_or_signal(NULL, pid);
10491 /* Yes, and it just exited */
10492 process_wait_result(NULL, pid, status);
10493 ret = WEXITSTATUS(status);
10494 if (WIFSIGNALED(status))
10495 ret = 128 + WTERMSIG(status);
10503 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10504 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10507 def = bb_strtou(argv[1], NULL, 10);
10508 if (errno || def < def_min || argv[2]) {
10509 bb_error_msg("%s: bad arguments", argv[0]);
10517 #if ENABLE_HUSH_LOOPS
10518 static int FAST_FUNC builtin_break(char **argv)
10521 if (G.depth_of_loop == 0) {
10522 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10523 /* if we came from builtin_continue(), need to undo "= 1" */
10524 G.flag_break_continue = 0;
10525 return EXIT_SUCCESS; /* bash compat */
10527 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10529 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10530 if (depth == UINT_MAX)
10531 G.flag_break_continue = BC_BREAK;
10532 if (G.depth_of_loop < depth)
10533 G.depth_break_continue = G.depth_of_loop;
10535 return EXIT_SUCCESS;
10538 static int FAST_FUNC builtin_continue(char **argv)
10540 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10541 return builtin_break(argv);
10545 #if ENABLE_HUSH_FUNCTIONS
10546 static int FAST_FUNC builtin_return(char **argv)
10550 if (G_flag_return_in_progress != -1) {
10551 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10552 return EXIT_FAILURE; /* bash compat */
10555 G_flag_return_in_progress = 1;
10558 * out of range: wraps around at 256, does not error out
10559 * non-numeric param:
10560 * f() { false; return qwe; }; f; echo $?
10561 * bash: return: qwe: numeric argument required <== we do this
10562 * 255 <== we also do this
10564 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10569 #if ENABLE_HUSH_TIMES
10570 static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
10572 static const uint8_t times_tbl[] ALIGN1 = {
10573 ' ', offsetof(struct tms, tms_utime),
10574 '\n', offsetof(struct tms, tms_stime),
10575 ' ', offsetof(struct tms, tms_cutime),
10576 '\n', offsetof(struct tms, tms_cstime),
10583 clk_tck = bb_clk_tck();
10588 unsigned sec, frac;
10590 t = *(clock_t *)(((char *) &buf) + p[1]);
10592 frac = t % clk_tck;
10593 printf("%um%u.%03us%c",
10594 sec / 60, sec % 60,
10595 (frac * 1000) / clk_tck,
10600 return EXIT_SUCCESS;
10604 #if ENABLE_HUSH_MEMLEAK
10605 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10610 # ifdef M_TRIM_THRESHOLD
10611 /* Optional. Reduces probability of false positives */
10614 /* Crude attempt to find where "free memory" starts,
10615 * sans fragmentation. */
10617 l = (unsigned long)p;
10620 if (l < (unsigned long)p) l = (unsigned long)p;
10626 struct mallinfo mi = mallinfo();
10627 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10628 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10632 if (!G.memleak_value)
10633 G.memleak_value = l;
10635 l -= G.memleak_value;
10642 /* Exitcode is "how many kilobytes we leaked since 1st call" */