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;
912 struct variable *top_var;
913 char **expanded_assignments;
914 #if ENABLE_HUSH_FUNCTIONS
915 struct function *top_func;
916 # if ENABLE_HUSH_LOCAL
917 struct variable **shadowed_vars_pp;
918 unsigned func_nest_level;
921 /* Signal and trap handling */
923 unsigned count_SIGCHLD;
924 unsigned handled_SIGCHLD;
925 smallint we_have_children;
927 struct FILE_list *FILE_list;
928 /* Which signals have non-DFL handler (even with no traps set)?
929 * Set at the start to:
930 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
931 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
932 * The rest is cleared right before execv syscalls.
933 * Other than these two times, never modified.
935 unsigned special_sig_mask;
937 unsigned fatal_sig_mask;
938 # define G_fatal_sig_mask (G.fatal_sig_mask)
940 # define G_fatal_sig_mask 0
943 char **traps; /* char *traps[NSIG] */
944 # define G_traps G.traps
946 # define G_traps ((char**)NULL)
948 sigset_t pending_set;
949 #if ENABLE_HUSH_MEMLEAK
950 unsigned long memleak_value;
956 #if ENABLE_FEATURE_EDITING
957 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
960 #define G (*ptr_to_globals)
961 /* Not #defining name to G.name - this quickly gets unwieldy
962 * (too many defines). Also, I actually prefer to see when a variable
963 * is global, thus "G." prefix is a useful hint */
964 #define INIT_G() do { \
965 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
966 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
967 sigfillset(&G.sa.sa_mask); \
968 G.sa.sa_flags = SA_RESTART; \
972 /* Function prototypes for builtins */
973 static int builtin_cd(char **argv) FAST_FUNC;
975 static int builtin_echo(char **argv) FAST_FUNC;
977 static int builtin_eval(char **argv) FAST_FUNC;
978 static int builtin_exec(char **argv) FAST_FUNC;
979 static int builtin_exit(char **argv) FAST_FUNC;
980 #if ENABLE_HUSH_EXPORT
981 static int builtin_export(char **argv) FAST_FUNC;
983 #if ENABLE_HUSH_READONLY
984 static int builtin_readonly(char **argv) FAST_FUNC;
987 static int builtin_fg_bg(char **argv) FAST_FUNC;
988 static int builtin_jobs(char **argv) FAST_FUNC;
990 #if ENABLE_HUSH_GETOPTS
991 static int builtin_getopts(char **argv) FAST_FUNC;
994 static int builtin_help(char **argv) FAST_FUNC;
996 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
997 static int builtin_history(char **argv) FAST_FUNC;
999 #if ENABLE_HUSH_LOCAL
1000 static int builtin_local(char **argv) FAST_FUNC;
1002 #if ENABLE_HUSH_MEMLEAK
1003 static int builtin_memleak(char **argv) FAST_FUNC;
1005 #if ENABLE_HUSH_PRINTF
1006 static int builtin_printf(char **argv) FAST_FUNC;
1008 static int builtin_pwd(char **argv) FAST_FUNC;
1009 #if ENABLE_HUSH_READ
1010 static int builtin_read(char **argv) FAST_FUNC;
1013 static int builtin_set(char **argv) FAST_FUNC;
1015 static int builtin_shift(char **argv) FAST_FUNC;
1016 static int builtin_source(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_TEST || BASH_TEST2
1018 static int builtin_test(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_TRAP
1021 static int builtin_trap(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_TYPE
1024 static int builtin_type(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_TIMES
1027 static int builtin_times(char **argv) FAST_FUNC;
1029 static int builtin_true(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_UMASK
1031 static int builtin_umask(char **argv) FAST_FUNC;
1033 #if ENABLE_HUSH_UNSET
1034 static int builtin_unset(char **argv) FAST_FUNC;
1036 #if ENABLE_HUSH_KILL
1037 static int builtin_kill(char **argv) FAST_FUNC;
1039 #if ENABLE_HUSH_WAIT
1040 static int builtin_wait(char **argv) FAST_FUNC;
1042 #if ENABLE_HUSH_LOOPS
1043 static int builtin_break(char **argv) FAST_FUNC;
1044 static int builtin_continue(char **argv) FAST_FUNC;
1046 #if ENABLE_HUSH_FUNCTIONS
1047 static int builtin_return(char **argv) FAST_FUNC;
1050 /* Table of built-in functions. They can be forked or not, depending on
1051 * context: within pipes, they fork. As simple commands, they do not.
1052 * When used in non-forking context, they can change global variables
1053 * in the parent shell process. If forked, of course they cannot.
1054 * For example, 'unset foo | whatever' will parse and run, but foo will
1055 * still be set at the end. */
1056 struct built_in_command {
1058 int (*b_function)(char **argv) FAST_FUNC;
1059 #if ENABLE_HUSH_HELP
1060 const char *b_descr;
1061 # define BLTIN(cmd, func, help) { cmd, func, help }
1063 # define BLTIN(cmd, func, help) { cmd, func }
1067 static const struct built_in_command bltins1[] = {
1068 BLTIN("." , builtin_source , "Run commands in file"),
1069 BLTIN(":" , builtin_true , NULL),
1071 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1073 #if ENABLE_HUSH_LOOPS
1074 BLTIN("break" , builtin_break , "Exit loop"),
1076 BLTIN("cd" , builtin_cd , "Change directory"),
1077 #if ENABLE_HUSH_LOOPS
1078 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1080 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1081 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1082 BLTIN("exit" , builtin_exit , NULL),
1083 #if ENABLE_HUSH_EXPORT
1084 BLTIN("export" , builtin_export , "Set environment variables"),
1087 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1089 #if ENABLE_HUSH_GETOPTS
1090 BLTIN("getopts" , builtin_getopts , NULL),
1092 #if ENABLE_HUSH_HELP
1093 BLTIN("help" , builtin_help , NULL),
1095 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1096 BLTIN("history" , builtin_history , "Show history"),
1099 BLTIN("jobs" , builtin_jobs , "List jobs"),
1101 #if ENABLE_HUSH_KILL
1102 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1104 #if ENABLE_HUSH_LOCAL
1105 BLTIN("local" , builtin_local , "Set local variables"),
1107 #if ENABLE_HUSH_MEMLEAK
1108 BLTIN("memleak" , builtin_memleak , NULL),
1110 #if ENABLE_HUSH_READ
1111 BLTIN("read" , builtin_read , "Input into variable"),
1113 #if ENABLE_HUSH_READONLY
1114 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1116 #if ENABLE_HUSH_FUNCTIONS
1117 BLTIN("return" , builtin_return , "Return from function"),
1120 BLTIN("set" , builtin_set , "Set positional parameters"),
1122 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1124 BLTIN("source" , builtin_source , NULL),
1126 #if ENABLE_HUSH_TIMES
1127 BLTIN("times" , builtin_times , NULL),
1129 #if ENABLE_HUSH_TRAP
1130 BLTIN("trap" , builtin_trap , "Trap signals"),
1132 BLTIN("true" , builtin_true , NULL),
1133 #if ENABLE_HUSH_TYPE
1134 BLTIN("type" , builtin_type , "Show command type"),
1136 #if ENABLE_HUSH_ULIMIT
1137 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1139 #if ENABLE_HUSH_UMASK
1140 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1142 #if ENABLE_HUSH_UNSET
1143 BLTIN("unset" , builtin_unset , "Unset variables"),
1145 #if ENABLE_HUSH_WAIT
1146 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1149 /* These builtins won't be used if we are on NOMMU and need to re-exec
1150 * (it's cheaper to run an external program in this case):
1152 static const struct built_in_command bltins2[] = {
1153 #if ENABLE_HUSH_TEST
1154 BLTIN("[" , builtin_test , NULL),
1157 BLTIN("[[" , builtin_test , NULL),
1159 #if ENABLE_HUSH_ECHO
1160 BLTIN("echo" , builtin_echo , NULL),
1162 #if ENABLE_HUSH_PRINTF
1163 BLTIN("printf" , builtin_printf , NULL),
1165 BLTIN("pwd" , builtin_pwd , NULL),
1166 #if ENABLE_HUSH_TEST
1167 BLTIN("test" , builtin_test , NULL),
1175 /* prevent disasters with G.debug_indent < 0 */
1176 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1177 # define debug_enter() (G.debug_indent++)
1178 # define debug_leave() (G.debug_indent--)
1180 # define indent() ((void)0)
1181 # define debug_enter() ((void)0)
1182 # define debug_leave() ((void)0)
1185 #ifndef debug_printf
1186 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1189 #ifndef debug_printf_parse
1190 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1193 #ifndef debug_printf_exec
1194 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_env
1198 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1201 #ifndef debug_printf_jobs
1202 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1203 # define DEBUG_JOBS 1
1205 # define DEBUG_JOBS 0
1208 #ifndef debug_printf_expand
1209 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1210 # define DEBUG_EXPAND 1
1212 # define DEBUG_EXPAND 0
1215 #ifndef debug_printf_varexp
1216 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1219 #ifndef debug_printf_glob
1220 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1221 # define DEBUG_GLOB 1
1223 # define DEBUG_GLOB 0
1226 #ifndef debug_printf_redir
1227 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1230 #ifndef debug_printf_list
1231 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1234 #ifndef debug_printf_subst
1235 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1238 #ifndef debug_printf_clean
1239 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1240 # define DEBUG_CLEAN 1
1242 # define DEBUG_CLEAN 0
1246 static void debug_print_strings(const char *prefix, char **vv)
1249 fdprintf(2, "%s:\n", prefix);
1251 fdprintf(2, " '%s'\n", *vv++);
1254 # define debug_print_strings(prefix, vv) ((void)0)
1258 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1261 static void *xxmalloc(int lineno, size_t size)
1263 void *ptr = xmalloc((size + 0xff) & ~0xff);
1264 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1267 static void *xxrealloc(int lineno, void *ptr, size_t size)
1269 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1270 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1273 static char *xxstrdup(int lineno, const char *str)
1275 char *ptr = xstrdup(str);
1276 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1279 static void xxfree(void *ptr)
1281 fdprintf(2, "free %p\n", ptr);
1284 # define xmalloc(s) xxmalloc(__LINE__, s)
1285 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1286 # define xstrdup(s) xxstrdup(__LINE__, s)
1287 # define free(p) xxfree(p)
1291 /* Syntax and runtime errors. They always abort scripts.
1292 * In interactive use they usually discard unparsed and/or unexecuted commands
1293 * and return to the prompt.
1294 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1297 # define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__)
1298 # define syntax_error(lineno, msg) syntax_error(msg)
1299 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1300 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1301 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1302 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1305 static void die_if_script(void)
1307 if (!G_interactive_fd) {
1308 if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
1309 xfunc_error_retval = G.last_exitcode;
1314 static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
1319 bb_error_msg("hush.c:%u", lineno);
1322 bb_verror_msg(fmt, p, NULL);
1327 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1330 bb_error_msg("syntax error: %s", msg);
1332 bb_error_msg("syntax error");
1336 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1338 bb_error_msg("syntax error at '%s'", msg);
1342 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1344 bb_error_msg("syntax error: unterminated %s", s);
1345 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
1349 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1351 char msg[2] = { ch, '\0' };
1352 syntax_error_unterm_str(lineno, msg);
1355 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1361 bb_error_msg("hush.c:%u", lineno);
1363 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1368 # undef msg_and_die_if_script
1369 # undef syntax_error
1370 # undef syntax_error_at
1371 # undef syntax_error_unterm_ch
1372 # undef syntax_error_unterm_str
1373 # undef syntax_error_unexpected_ch
1375 # define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
1376 # define syntax_error(msg) syntax_error(__LINE__, msg)
1377 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1378 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1379 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1380 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1384 #if ENABLE_HUSH_INTERACTIVE
1385 static void cmdedit_update_prompt(void);
1387 # define cmdedit_update_prompt() ((void)0)
1391 /* Utility functions
1393 /* Replace each \x with x in place, return ptr past NUL. */
1394 static char *unbackslash(char *src)
1396 char *dst = src = strchrnul(src, '\\');
1400 if ((*dst++ = *src++) == '\0')
1406 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1427 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1428 v[count1 + count2] = NULL;
1431 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1435 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1437 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1438 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1441 #define add_strings_to_strings(strings, add, need_to_dup) \
1442 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1445 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1446 static char **add_string_to_strings(char **strings, char *add)
1451 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1454 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1456 char **ptr = add_string_to_strings(strings, add);
1457 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1460 #define add_string_to_strings(strings, add) \
1461 xx_add_string_to_strings(__LINE__, strings, add)
1464 static void free_strings(char **strings)
1478 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1482 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1492 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1496 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1502 /* fd was not open? */
1507 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1508 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1514 /* Manipulating the list of open FILEs */
1515 static FILE *remember_FILE(FILE *fp)
1518 struct FILE_list *n = xmalloc(sizeof(*n));
1519 n->next = G.FILE_list;
1523 close_on_exec_on(n->fd);
1527 static void fclose_and_forget(FILE *fp)
1529 struct FILE_list **pp = &G.FILE_list;
1531 struct FILE_list *cur = *pp;
1532 if (cur->fp == fp) {
1541 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1543 struct FILE_list *fl = G.FILE_list;
1546 /* We use it only on script files, they are all CLOEXEC */
1547 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1548 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1555 static void restore_redirected_FILEs(void)
1557 struct FILE_list *fl = G.FILE_list;
1559 int should_be = fileno(fl->fp);
1560 if (fl->fd != should_be) {
1561 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1562 xmove_fd(fl->fd, should_be);
1568 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1569 static void close_all_FILE_list(void)
1571 struct FILE_list *fl = G.FILE_list;
1573 /* fclose would also free FILE object.
1574 * It is disastrous if we share memory with a vforked parent.
1575 * I'm not sure we never come here after vfork.
1576 * Therefore just close fd, nothing more.
1578 /*fclose(fl->fp); - unsafe */
1584 static int fd_in_FILEs(int fd)
1586 struct FILE_list *fl = G.FILE_list;
1596 /* Helpers for setting new $n and restoring them back
1598 typedef struct save_arg_t {
1602 IF_HUSH_SET(smallint sv_g_malloced;)
1605 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1607 sv->sv_argv0 = argv[0];
1608 sv->sv_g_argv = G.global_argv;
1609 sv->sv_g_argc = G.global_argc;
1610 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1612 argv[0] = G.global_argv[0]; /* retain $0 */
1613 G.global_argv = argv;
1614 IF_HUSH_SET(G.global_args_malloced = 0;)
1616 G.global_argc = 1 + string_array_len(argv + 1);
1619 static void restore_G_args(save_arg_t *sv, char **argv)
1622 if (G.global_args_malloced) {
1623 /* someone ran "set -- arg1 arg2 ...", undo */
1624 char **pp = G.global_argv;
1625 while (*++pp) /* note: does not free $0 */
1627 free(G.global_argv);
1630 argv[0] = sv->sv_argv0;
1631 G.global_argv = sv->sv_g_argv;
1632 G.global_argc = sv->sv_g_argc;
1633 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1637 /* Basic theory of signal handling in shell
1638 * ========================================
1639 * This does not describe what hush does, rather, it is current understanding
1640 * what it _should_ do. If it doesn't, it's a bug.
1641 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1643 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1644 * is finished or backgrounded. It is the same in interactive and
1645 * non-interactive shells, and is the same regardless of whether
1646 * a user trap handler is installed or a shell special one is in effect.
1647 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1648 * backgrounds (i.e. stops) or kills all members of currently running
1651 * Wait builtin is interruptible by signals for which user trap is set
1652 * or by SIGINT in interactive shell.
1654 * Trap handlers will execute even within trap handlers. (right?)
1656 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1657 * except for handlers set to '' (empty string).
1659 * If job control is off, backgrounded commands ("cmd &")
1660 * have SIGINT, SIGQUIT set to SIG_IGN.
1662 * Commands which are run in command substitution ("`cmd`")
1663 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1665 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1666 * by the shell from its parent.
1668 * Signals which differ from SIG_DFL action
1669 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1672 * SIGTERM (interactive): ignore
1673 * SIGHUP (interactive):
1674 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1675 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1676 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1677 * that all pipe members are stopped. Try this in bash:
1678 * while :; do :; done - ^Z does not background it
1679 * (while :; do :; done) - ^Z backgrounds it
1680 * SIGINT (interactive): wait for last pipe, ignore the rest
1681 * of the command line, show prompt. NB: ^C does not send SIGINT
1682 * to interactive shell while shell is waiting for a pipe,
1683 * since shell is bg'ed (is not in foreground process group).
1684 * Example 1: this waits 5 sec, but does not execute ls:
1685 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1686 * Example 2: this does not wait and does not execute ls:
1687 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1688 * Example 3: this does not wait 5 sec, but executes ls:
1689 * "sleep 5; ls -l" + press ^C
1690 * Example 4: this does not wait and does not execute ls:
1691 * "sleep 5 & wait; ls -l" + press ^C
1693 * (What happens to signals which are IGN on shell start?)
1694 * (What happens with signal mask on shell start?)
1696 * Old implementation
1697 * ==================
1698 * We use in-kernel pending signal mask to determine which signals were sent.
1699 * We block all signals which we don't want to take action immediately,
1700 * i.e. we block all signals which need to have special handling as described
1701 * above, and all signals which have traps set.
1702 * After each pipe execution, we extract any pending signals via sigtimedwait()
1705 * unsigned special_sig_mask: a mask of such "special" signals
1706 * sigset_t blocked_set: current blocked signal set
1709 * clear bit in blocked_set unless it is also in special_sig_mask
1710 * "trap 'cmd' SIGxxx":
1711 * set bit in blocked_set (even if 'cmd' is '')
1712 * after [v]fork, if we plan to be a shell:
1713 * unblock signals with special interactive handling
1714 * (child shell is not interactive),
1715 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1716 * after [v]fork, if we plan to exec:
1717 * POSIX says fork clears pending signal mask in child - no need to clear it.
1718 * Restore blocked signal set to one inherited by shell just prior to exec.
1720 * Note: as a result, we do not use signal handlers much. The only uses
1721 * are to count SIGCHLDs
1722 * and to restore tty pgrp on signal-induced exit.
1725 * Standard says "When a subshell is entered, traps that are not being ignored
1726 * are set to the default actions". bash interprets it so that traps which
1727 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1729 * Problem: the above approach makes it unwieldy to catch signals while
1730 * we are in read builtin, or while we read commands from stdin:
1731 * masked signals are not visible!
1733 * New implementation
1734 * ==================
1735 * We record each signal we are interested in by installing signal handler
1736 * for them - a bit like emulating kernel pending signal mask in userspace.
1737 * We are interested in: signals which need to have special handling
1738 * as described above, and all signals which have traps set.
1739 * Signals are recorded in pending_set.
1740 * After each pipe execution, we extract any pending signals
1743 * unsigned special_sig_mask: a mask of shell-special signals.
1744 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1745 * char *traps[sig] if trap for sig is set (even if it's '').
1746 * sigset_t pending_set: set of sigs we received.
1749 * if sig is in special_sig_mask, set handler back to:
1750 * record_pending_signo, or to IGN if it's a tty stop signal
1751 * if sig is in fatal_sig_mask, set handler back to sigexit.
1752 * else: set handler back to SIG_DFL
1753 * "trap 'cmd' SIGxxx":
1754 * set handler to record_pending_signo.
1756 * set handler to SIG_IGN.
1757 * after [v]fork, if we plan to be a shell:
1758 * set signals with special interactive handling to SIG_DFL
1759 * (because child shell is not interactive),
1760 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1761 * after [v]fork, if we plan to exec:
1762 * POSIX says fork clears pending signal mask in child - no need to clear it.
1764 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1765 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1768 * Standard says "When a subshell is entered, traps that are not being ignored
1769 * are set to the default actions". bash interprets it so that traps which
1770 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1773 SPECIAL_INTERACTIVE_SIGS = 0
1778 SPECIAL_JOBSTOP_SIGS = 0
1787 static void record_pending_signo(int sig)
1789 sigaddset(&G.pending_set, sig);
1790 #if ENABLE_HUSH_FAST
1791 if (sig == SIGCHLD) {
1793 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1798 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1800 struct sigaction old_sa;
1802 /* We could use signal() to install handlers... almost:
1803 * except that we need to mask ALL signals while handlers run.
1804 * I saw signal nesting in strace, race window isn't small.
1805 * SA_RESTART is also needed, but in Linux, signal()
1806 * sets SA_RESTART too.
1808 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1809 /* sigfillset(&G.sa.sa_mask); - already done */
1810 /* G.sa.sa_flags = SA_RESTART; - already done */
1811 G.sa.sa_handler = handler;
1812 sigaction(sig, &G.sa, &old_sa);
1813 return old_sa.sa_handler;
1816 static void hush_exit(int exitcode) NORETURN;
1818 static void restore_ttypgrp_and__exit(void) NORETURN;
1819 static void restore_ttypgrp_and__exit(void)
1821 /* xfunc has failed! die die die */
1822 /* no EXIT traps, this is an escape hatch! */
1824 hush_exit(xfunc_error_retval);
1829 /* Needed only on some libc:
1830 * It was observed that on exit(), fgetc'ed buffered data
1831 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1832 * With the net effect that even after fork(), not vfork(),
1833 * exit() in NOEXECed applet in "sh SCRIPT":
1834 * noexec_applet_here
1835 * echo END_OF_SCRIPT
1836 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1837 * This makes "echo END_OF_SCRIPT" executed twice.
1838 * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
1839 * and in `cmd` handling.
1840 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1842 static void fflush_and__exit(void) NORETURN;
1843 static void fflush_and__exit(void)
1846 _exit(xfunc_error_retval);
1849 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1850 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1851 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1852 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1854 /* Restores tty foreground process group, and exits.
1855 * May be called as signal handler for fatal signal
1856 * (will resend signal to itself, producing correct exit state)
1857 * or called directly with -EXITCODE.
1858 * We also call it if xfunc is exiting.
1860 static void sigexit(int sig) NORETURN;
1861 static void sigexit(int sig)
1863 /* Careful: we can end up here after [v]fork. Do not restore
1864 * tty pgrp then, only top-level shell process does that */
1865 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1866 /* Disable all signals: job control, SIGPIPE, etc.
1867 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1869 sigprocmask_allsigs(SIG_BLOCK);
1870 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1873 /* Not a signal, just exit */
1877 kill_myself_with_sig(sig); /* does not return */
1881 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1882 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1886 static sighandler_t pick_sighandler(unsigned sig)
1888 sighandler_t handler = SIG_DFL;
1889 if (sig < sizeof(unsigned)*8) {
1890 unsigned sigmask = (1 << sig);
1894 if (G_fatal_sig_mask & sigmask)
1898 /* sig has special handling? */
1899 if (G.special_sig_mask & sigmask) {
1900 handler = record_pending_signo;
1901 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1902 * in order to ignore them: they will be raised
1903 * in an endless loop when we try to do some
1904 * terminal ioctls! We do have to _ignore_ these.
1906 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1913 /* Restores tty foreground process group, and exits. */
1914 static void hush_exit(int exitcode)
1916 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1917 save_history(G.line_input_state);
1921 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1923 /* argv[0] is unused */
1924 argv[1] = G_traps[0];
1926 G.exiting = 1; /* prevent EXIT trap recursion */
1927 /* Note: G_traps[0] is not cleared!
1928 * "trap" will still show it, if executed
1933 #if ENABLE_FEATURE_CLEAN_UP
1935 struct variable *cur_var;
1936 if (G.cwd != bb_msg_unknown)
1938 cur_var = G.top_var;
1940 struct variable *tmp = cur_var;
1941 if (!cur_var->max_len)
1942 free(cur_var->varstr);
1943 cur_var = cur_var->next;
1951 sigexit(- (exitcode & 0xff));
1958 //TODO: return a mask of ALL handled sigs?
1959 static int check_and_run_traps(void)
1966 if (sigisemptyset(&G.pending_set))
1971 if (sigismember(&G.pending_set, sig)) {
1972 sigdelset(&G.pending_set, sig);
1975 } while (sig < NSIG);
1978 if (G_traps && G_traps[sig]) {
1979 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1980 if (G_traps[sig][0]) {
1981 /* We have user-defined handler */
1982 smalluint save_rcode;
1984 /* argv[0] is unused */
1985 argv[1] = G_traps[sig];
1987 save_rcode = G.last_exitcode;
1989 //FIXME: shouldn't it be set to 128 + sig instead?
1990 G.last_exitcode = save_rcode;
1992 } /* else: "" trap, ignoring signal */
1995 /* not a trap: special action */
1998 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
2004 //TODO: why are we doing this? ash and dash don't do this,
2005 //they have no handler for SIGHUP at all,
2006 //they rely on kernel to send SIGHUP+SIGCONT to orphaned process groups
2008 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
2009 /* bash is observed to signal whole process groups,
2010 * not individual processes */
2011 for (job = G.job_list; job; job = job->next) {
2014 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
2015 if (kill(- job->pgrp, SIGHUP) == 0)
2016 kill(- job->pgrp, SIGCONT);
2021 #if ENABLE_HUSH_FAST
2023 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
2025 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2027 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2028 * This simplifies wait builtin a bit.
2032 default: /* ignored: */
2033 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
2034 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
2036 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2037 * Example: wait is not interrupted by TERM
2038 * in interactive shell, because TERM is ignored.
2047 static const char *get_cwd(int force)
2049 if (force || G.cwd == NULL) {
2050 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2051 * we must not try to free(bb_msg_unknown) */
2052 if (G.cwd == bb_msg_unknown)
2054 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2056 G.cwd = bb_msg_unknown;
2063 * Shell and environment variable support
2065 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2067 struct variable **pp;
2068 struct variable *cur;
2071 while ((cur = *pp) != NULL) {
2072 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2079 static const char* FAST_FUNC get_local_var_value(const char *name)
2081 struct variable **vpp;
2082 unsigned len = strlen(name);
2084 if (G.expanded_assignments) {
2085 char **cpp = G.expanded_assignments;
2088 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2089 return cp + len + 1;
2094 vpp = get_ptr_to_local_var(name, len);
2096 return (*vpp)->varstr + len + 1;
2098 if (strcmp(name, "PPID") == 0)
2099 return utoa(G.root_ppid);
2100 // bash compat: UID? EUID?
2101 #if ENABLE_HUSH_RANDOM_SUPPORT
2102 if (strcmp(name, "RANDOM") == 0)
2103 return utoa(next_random(&G.random_gen));
2108 /* str holds "NAME=VAL" and is expected to be malloced.
2109 * We take ownership of it.
2111 #define SETFLAG_EXPORT (1 << 0)
2112 #define SETFLAG_UNEXPORT (1 << 1)
2113 #define SETFLAG_MAKE_RO (1 << 2)
2114 #define SETFLAG_LOCAL_SHIFT 3
2115 static int set_local_var(char *str, unsigned flags)
2117 struct variable **var_pp;
2118 struct variable *cur;
2119 char *free_me = NULL;
2122 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2124 eq_sign = strchr(str, '=');
2125 if (!eq_sign) { /* not expected to ever happen? */
2130 name_len = eq_sign - str + 1; /* including '=' */
2131 var_pp = &G.top_var;
2132 while ((cur = *var_pp) != NULL) {
2133 if (strncmp(cur->varstr, str, name_len) != 0) {
2134 var_pp = &cur->next;
2138 /* We found an existing var with this name */
2139 if (cur->flg_read_only) {
2140 bb_error_msg("%s: readonly variable", str);
2142 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2143 //but export per se succeeds (does put the var in env). We don't mimic that.
2146 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2147 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2152 #if ENABLE_HUSH_LOCAL
2153 if (cur->func_nest_level < local_lvl) {
2154 /* New variable is declared as local,
2155 * and existing one is global, or local
2156 * from enclosing function.
2157 * Remove and save old one: */
2158 *var_pp = cur->next;
2159 cur->next = *G.shadowed_vars_pp;
2160 *G.shadowed_vars_pp = cur;
2161 /* bash 3.2.33(1) and exported vars:
2163 * # f() { local z=a; env | grep ^z; }
2169 if (cur->flg_export)
2170 flags |= SETFLAG_EXPORT;
2174 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2179 if (cur->max_len != 0) {
2180 if (cur->max_len >= strlen(str)) {
2181 /* This one is from startup env, reuse space */
2182 strcpy(cur->varstr, str);
2187 goto set_str_and_exp;
2189 /* max_len == 0 signifies "malloced" var, which we can
2190 * (and have to) free. But we can't free(cur->varstr) here:
2191 * if cur->flg_export is 1, it is in the environment.
2192 * We should either unsetenv+free, or wait until putenv,
2193 * then putenv(new)+free(old).
2195 free_me = cur->varstr;
2196 goto set_str_and_exp;
2199 /* Not found - create new variable struct */
2200 cur = xzalloc(sizeof(*cur));
2201 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2202 cur->next = *var_pp;
2208 #if !BB_MMU || ENABLE_HUSH_READONLY
2209 if (flags & SETFLAG_MAKE_RO) {
2210 cur->flg_read_only = 1;
2213 if (flags & SETFLAG_EXPORT)
2214 cur->flg_export = 1;
2215 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2216 cmdedit_update_prompt();
2217 if (cur->flg_export) {
2218 if (flags & SETFLAG_UNEXPORT) {
2219 cur->flg_export = 0;
2220 /* unsetenv was already done */
2223 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2224 i = putenv(cur->varstr);
2225 /* only now we can free old exported malloced string */
2234 /* Used at startup and after each cd */
2235 static void set_pwd_var(unsigned flag)
2237 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2240 static int unset_local_var_len(const char *name, int name_len)
2242 struct variable *cur;
2243 struct variable **var_pp;
2246 return EXIT_SUCCESS;
2247 var_pp = &G.top_var;
2248 while ((cur = *var_pp) != NULL) {
2249 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2250 if (cur->flg_read_only) {
2251 bb_error_msg("%s: readonly variable", name);
2252 return EXIT_FAILURE;
2254 *var_pp = cur->next;
2255 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2256 bb_unsetenv(cur->varstr);
2257 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2258 cmdedit_update_prompt();
2262 return EXIT_SUCCESS;
2264 var_pp = &cur->next;
2266 return EXIT_SUCCESS;
2269 #if ENABLE_HUSH_UNSET
2270 static int unset_local_var(const char *name)
2272 return unset_local_var_len(name, strlen(name));
2276 static void unset_vars(char **strings)
2284 const char *eq = strchrnul(*v, '=');
2285 unset_local_var_len(*v, (int)(eq - *v));
2291 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2292 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2294 char *var = xasprintf("%s=%s", name, val);
2295 set_local_var(var, /*flag:*/ 0);
2301 * Helpers for "var1=val1 var2=val2 cmd" feature
2303 static void add_vars(struct variable *var)
2305 struct variable *next;
2309 var->next = G.top_var;
2311 if (var->flg_export) {
2312 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2313 putenv(var->varstr);
2315 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2321 static struct variable *set_vars_and_save_old(char **strings)
2324 struct variable *old = NULL;
2330 struct variable *var_p;
2331 struct variable **var_pp;
2334 eq = strchr(*s, '=');
2336 var_pp = get_ptr_to_local_var(*s, eq - *s);
2339 if (var_p->flg_read_only) {
2341 bb_error_msg("%s: readonly variable", *s);
2343 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2344 * If VAR is readonly, leaving it in the list
2345 * after asssignment error (msg above)
2346 * causes doubled error message later, on unset.
2348 debug_printf_env("removing/freeing '%s' element\n", *s);
2351 do { *p = p[1]; p++; } while (*p);
2354 /* Remove variable from global linked list */
2355 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2356 *var_pp = var_p->next;
2357 /* Add it to returned list */
2361 set_local_var(*s, SETFLAG_EXPORT);
2373 static void reinit_unicode_for_hush(void)
2375 /* Unicode support should be activated even if LANG is set
2376 * _during_ shell execution, not only if it was set when
2377 * shell was started. Therefore, re-check LANG every time:
2379 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2380 || ENABLE_UNICODE_USING_LOCALE
2382 const char *s = get_local_var_value("LC_ALL");
2383 if (!s) s = get_local_var_value("LC_CTYPE");
2384 if (!s) s = get_local_var_value("LANG");
2390 * in_str support (strings, and "strings" read from files).
2393 #if ENABLE_HUSH_INTERACTIVE
2394 /* To test correct lineedit/interactive behavior, type from command line:
2400 * It exercises a lot of corner cases.
2402 static void cmdedit_update_prompt(void)
2404 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2405 G.PS1 = get_local_var_value("PS1");
2408 G.PS2 = get_local_var_value("PS2");
2415 static const char *setup_prompt_string(int promptmode)
2417 const char *prompt_str;
2418 debug_printf("setup_prompt_string %d ", promptmode);
2419 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2420 /* Set up the prompt */
2421 if (promptmode == 0) { /* PS1 */
2423 /* bash uses $PWD value, even if it is set by user.
2424 * It uses current dir only if PWD is unset.
2425 * We always use current dir. */
2426 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2431 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2432 debug_printf("prompt_str '%s'\n", prompt_str);
2435 static int get_user_input(struct in_str *i)
2438 const char *prompt_str;
2440 prompt_str = setup_prompt_string(i->promptmode);
2441 # if ENABLE_FEATURE_EDITING
2443 reinit_unicode_for_hush();
2444 if (G.flag_SIGINT) {
2445 /* There was ^C'ed, make it look prettier: */
2449 /* buglet: SIGINT will not make new prompt to appear _at once_,
2450 * only after <Enter>. (^C works immediately) */
2451 r = read_line_input(G.line_input_state, prompt_str,
2452 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
2454 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2457 check_and_run_traps();
2458 if (r != 0 && !G.flag_SIGINT)
2460 /* ^C or SIGINT: repeat */
2461 /* bash prints ^C even on real SIGINT (non-kbd generated) */
2462 write(STDOUT_FILENO, "^C", 2);
2463 G.last_exitcode = 128 + SIGINT;
2466 /* EOF/error detected */
2468 i->peek_buf[0] = r = EOF;
2471 i->p = G.user_input_buf;
2472 return (unsigned char)*i->p++;
2476 if (i->last_char == '\0' || i->last_char == '\n') {
2477 /* Why check_and_run_traps here? Try this interactively:
2478 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2479 * $ <[enter], repeatedly...>
2480 * Without check_and_run_traps, handler never runs.
2482 check_and_run_traps();
2483 fputs(prompt_str, stdout);
2486 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2488 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2489 * no ^C masking happens during fgetc, no special code for ^C:
2490 * it generates SIGINT as usual.
2492 check_and_run_traps();
2494 G.last_exitcode = 128 + SIGINT;
2501 /* This is the magic location that prints prompts
2502 * and gets data back from the user */
2503 static int fgetc_interactive(struct in_str *i)
2506 /* If it's interactive stdin, get new line. */
2507 if (G_interactive_fd && i->file == stdin) {
2508 /* Returns first char (or EOF), the rest is in i->p[] */
2509 ch = get_user_input(i);
2510 i->promptmode = 1; /* PS2 */
2512 /* Not stdin: script file, sourced file, etc */
2513 do ch = fgetc(i->file); while (ch == '\0');
2518 static inline int fgetc_interactive(struct in_str *i)
2521 do ch = fgetc(i->file); while (ch == '\0');
2524 #endif /* INTERACTIVE */
2526 static int i_getch(struct in_str *i)
2531 /* string-based in_str */
2532 ch = (unsigned char)*i->p;
2541 /* FILE-based in_str */
2543 #if ENABLE_FEATURE_EDITING
2544 /* This can be stdin, check line editing char[] buffer */
2545 if (i->p && *i->p != '\0') {
2546 ch = (unsigned char)*i->p++;
2550 /* peek_buf[] is an int array, not char. Can contain EOF. */
2551 ch = i->peek_buf[0];
2553 int ch2 = i->peek_buf[1];
2554 i->peek_buf[0] = ch2;
2555 if (ch2 == 0) /* very likely, avoid redundant write */
2561 ch = fgetc_interactive(i);
2563 debug_printf("file_get: got '%c' %d\n", ch, ch);
2568 static int i_peek(struct in_str *i)
2573 /* string-based in_str */
2574 /* Doesn't report EOF on NUL. None of the callers care. */
2575 return (unsigned char)*i->p;
2578 /* FILE-based in_str */
2580 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2581 /* This can be stdin, check line editing char[] buffer */
2582 if (i->p && *i->p != '\0')
2583 return (unsigned char)*i->p;
2585 /* peek_buf[] is an int array, not char. Can contain EOF. */
2586 ch = i->peek_buf[0];
2590 /* Need to get a new char */
2591 ch = fgetc_interactive(i);
2592 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2594 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2595 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2601 i->peek_buf[0] = ch;
2602 /*i->peek_buf[1] = 0; - already is */
2606 /* Only ever called if i_peek() was called, and did not return EOF.
2607 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2608 * not end-of-line. Therefore we never need to read a new editing line here.
2610 static int i_peek2(struct in_str *i)
2614 /* There are two cases when i->p[] buffer exists.
2615 * (1) it's a string in_str.
2616 * (2) It's a file, and we have a saved line editing buffer.
2617 * In both cases, we know that i->p[0] exists and not NUL, and
2618 * the peek2 result is in i->p[1].
2621 return (unsigned char)i->p[1];
2623 /* Now we know it is a file-based in_str. */
2625 /* peek_buf[] is an int array, not char. Can contain EOF. */
2626 /* Is there 2nd char? */
2627 ch = i->peek_buf[1];
2629 /* We did not read it yet, get it now */
2630 do ch = fgetc(i->file); while (ch == '\0');
2631 i->peek_buf[1] = ch;
2634 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2638 static void setup_file_in_str(struct in_str *i, FILE *f)
2640 memset(i, 0, sizeof(*i));
2641 /* i->promptmode = 0; - PS1 (memset did it) */
2646 static void setup_string_in_str(struct in_str *i, const char *s)
2648 memset(i, 0, sizeof(*i));
2649 /* i->promptmode = 0; - PS1 (memset did it) */
2650 /*i->file = NULL */;
2658 #define B_CHUNK (32 * sizeof(char*))
2660 static void o_reset_to_empty_unquoted(o_string *o)
2663 o->has_quoted_part = 0;
2668 static void o_free(o_string *o)
2671 memset(o, 0, sizeof(*o));
2674 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2679 static void o_grow_by(o_string *o, int len)
2681 if (o->length + len > o->maxlen) {
2682 o->maxlen += (2 * len) | (B_CHUNK-1);
2683 o->data = xrealloc(o->data, 1 + o->maxlen);
2687 static void o_addchr(o_string *o, int ch)
2689 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2690 if (o->length < o->maxlen) {
2691 /* likely. avoid o_grow_by() call */
2693 o->data[o->length] = ch;
2695 o->data[o->length] = '\0';
2703 /* Valid only if we know o_string is not empty */
2704 static void o_delchr(o_string *o)
2707 o->data[o->length] = '\0';
2711 static void o_addblock(o_string *o, const char *str, int len)
2714 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2718 static void o_addstr(o_string *o, const char *str)
2720 o_addblock(o, str, strlen(str));
2724 static void nommu_addchr(o_string *o, int ch)
2730 # define nommu_addchr(o, str) ((void)0)
2733 static void o_addstr_with_NUL(o_string *o, const char *str)
2735 o_addblock(o, str, strlen(str) + 1);
2739 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2740 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2741 * Apparently, on unquoted $v bash still does globbing
2742 * ("v='*.txt'; echo $v" prints all .txt files),
2743 * but NOT brace expansion! Thus, there should be TWO independent
2744 * quoting mechanisms on $v expansion side: one protects
2745 * $v from brace expansion, and other additionally protects "$v" against globbing.
2746 * We have only second one.
2749 #if ENABLE_HUSH_BRACE_EXPANSION
2750 # define MAYBE_BRACES "{}"
2752 # define MAYBE_BRACES ""
2755 /* My analysis of quoting semantics tells me that state information
2756 * is associated with a destination, not a source.
2758 static void o_addqchr(o_string *o, int ch)
2761 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2766 o->data[o->length] = '\\';
2769 o->data[o->length] = ch;
2771 o->data[o->length] = '\0';
2774 static void o_addQchr(o_string *o, int ch)
2777 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2778 && strchr("*?[\\" MAYBE_BRACES, ch)
2781 o->data[o->length] = '\\';
2785 o->data[o->length] = ch;
2787 o->data[o->length] = '\0';
2790 static void o_addqblock(o_string *o, const char *str, int len)
2795 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2796 if (ordinary_cnt > len) /* paranoia */
2798 o_addblock(o, str, ordinary_cnt);
2799 if (ordinary_cnt == len)
2800 return; /* NUL is already added by o_addblock */
2801 str += ordinary_cnt;
2802 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2806 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2808 o->data[o->length] = '\\';
2812 o->data[o->length] = ch;
2815 o->data[o->length] = '\0';
2818 static void o_addQblock(o_string *o, const char *str, int len)
2820 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2821 o_addblock(o, str, len);
2824 o_addqblock(o, str, len);
2827 static void o_addQstr(o_string *o, const char *str)
2829 o_addQblock(o, str, strlen(str));
2832 /* A special kind of o_string for $VAR and `cmd` expansion.
2833 * It contains char* list[] at the beginning, which is grown in 16 element
2834 * increments. Actual string data starts at the next multiple of 16 * (char*).
2835 * list[i] contains an INDEX (int!) into this string data.
2836 * It means that if list[] needs to grow, data needs to be moved higher up
2837 * but list[i]'s need not be modified.
2838 * NB: remembering how many list[i]'s you have there is crucial.
2839 * o_finalize_list() operation post-processes this structure - calculates
2840 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2842 #if DEBUG_EXPAND || DEBUG_GLOB
2843 static void debug_print_list(const char *prefix, o_string *o, int n)
2845 char **list = (char**)o->data;
2846 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2850 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2851 prefix, list, n, string_start, o->length, o->maxlen,
2852 !!(o->o_expflags & EXP_FLAG_GLOB),
2854 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2857 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2858 o->data + (int)(uintptr_t)list[i] + string_start,
2859 o->data + (int)(uintptr_t)list[i] + string_start);
2863 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2865 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2869 # define debug_print_list(prefix, o, n) ((void)0)
2872 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2873 * in list[n] so that it points past last stored byte so far.
2874 * It returns n+1. */
2875 static int o_save_ptr_helper(o_string *o, int n)
2877 char **list = (char**)o->data;
2881 if (!o->has_empty_slot) {
2882 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2883 string_len = o->length - string_start;
2884 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2885 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2886 /* list[n] points to string_start, make space for 16 more pointers */
2887 o->maxlen += 0x10 * sizeof(list[0]);
2888 o->data = xrealloc(o->data, o->maxlen + 1);
2889 list = (char**)o->data;
2890 memmove(list + n + 0x10, list + n, string_len);
2891 o->length += 0x10 * sizeof(list[0]);
2893 debug_printf_list("list[%d]=%d string_start=%d\n",
2894 n, string_len, string_start);
2897 /* We have empty slot at list[n], reuse without growth */
2898 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2899 string_len = o->length - string_start;
2900 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2901 n, string_len, string_start);
2902 o->has_empty_slot = 0;
2904 o->has_quoted_part = 0;
2905 list[n] = (char*)(uintptr_t)string_len;
2909 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2910 static int o_get_last_ptr(o_string *o, int n)
2912 char **list = (char**)o->data;
2913 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2915 return ((int)(uintptr_t)list[n-1]) + string_start;
2918 #if ENABLE_HUSH_BRACE_EXPANSION
2919 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2920 * first, it processes even {a} (no commas), second,
2921 * I didn't manage to make it return strings when they don't match
2922 * existing files. Need to re-implement it.
2926 static int glob_needed(const char *s)
2935 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2941 /* Return pointer to next closing brace or to comma */
2942 static const char *next_brace_sub(const char *cp)
2946 while (*cp != '\0') {
2953 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2959 return *cp != '\0' ? cp : NULL;
2961 /* Recursive brace globber. Note: may garble pattern[]. */
2962 static int glob_brace(char *pattern, o_string *o, int n)
2964 char *new_pattern_buf;
2971 debug_printf_glob("glob_brace('%s')\n", pattern);
2977 if (*begin == '{') {
2978 /* Find the first sub-pattern and at the same time
2979 * find the rest after the closing brace */
2980 next = next_brace_sub(begin);
2982 /* An illegal expression */
2986 /* "{abc}" with no commas - illegal
2987 * brace expr, disregard and skip it */
2993 if (*begin == '\\' && begin[1] != '\0')
2997 debug_printf_glob("begin:%s\n", begin);
2998 debug_printf_glob("next:%s\n", next);
3000 /* Now find the end of the whole brace expression */
3002 while (*rest != '}') {
3003 rest = next_brace_sub(rest);
3005 /* An illegal expression */
3008 debug_printf_glob("rest:%s\n", rest);
3010 rest_len = strlen(++rest) + 1;
3012 /* We are sure the brace expression is well-formed */
3014 /* Allocate working buffer large enough for our work */
3015 new_pattern_buf = xmalloc(strlen(pattern));
3017 /* We have a brace expression. BEGIN points to the opening {,
3018 * NEXT points past the terminator of the first element, and REST
3019 * points past the final }. We will accumulate result names from
3020 * recursive runs for each brace alternative in the buffer using
3025 /* Construct the new glob expression */
3028 mempcpy(new_pattern_buf,
3029 /* We know the prefix for all sub-patterns */
3030 pattern, begin - pattern),
3034 /* Note: glob_brace() may garble new_pattern_buf[].
3035 * That's why we re-copy prefix every time (1st memcpy above).
3037 n = glob_brace(new_pattern_buf, o, n);
3039 /* We saw the last entry */
3043 next = next_brace_sub(next);
3045 free(new_pattern_buf);
3053 memset(&globdata, 0, sizeof(globdata));
3054 gr = glob(pattern, 0, NULL, &globdata);
3055 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3057 if (gr == GLOB_NOMATCH) {
3058 globfree(&globdata);
3059 /* NB: garbles parameter */
3060 unbackslash(pattern);
3061 o_addstr_with_NUL(o, pattern);
3062 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3063 return o_save_ptr_helper(o, n);
3065 if (gr == GLOB_NOSPACE)
3066 bb_error_msg_and_die(bb_msg_memory_exhausted);
3067 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3068 * but we didn't specify it. Paranoia again. */
3069 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3071 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3072 char **argv = globdata.gl_pathv;
3074 o_addstr_with_NUL(o, *argv);
3075 n = o_save_ptr_helper(o, n);
3081 globfree(&globdata);
3085 /* Performs globbing on last list[],
3086 * saving each result as a new list[].
3088 static int perform_glob(o_string *o, int n)
3090 char *pattern, *copy;
3092 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3094 return o_save_ptr_helper(o, n);
3095 pattern = o->data + o_get_last_ptr(o, n);
3096 debug_printf_glob("glob pattern '%s'\n", pattern);
3097 if (!glob_needed(pattern)) {
3098 /* unbackslash last string in o in place, fix length */
3099 o->length = unbackslash(pattern) - o->data;
3100 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3101 return o_save_ptr_helper(o, n);
3104 copy = xstrdup(pattern);
3105 /* "forget" pattern in o */
3106 o->length = pattern - o->data;
3107 n = glob_brace(copy, o, n);
3110 debug_print_list("perform_glob returning", o, n);
3114 #else /* !HUSH_BRACE_EXPANSION */
3117 static int glob_needed(const char *s)
3126 if (*s == '*' || *s == '[' || *s == '?')
3132 /* Performs globbing on last list[],
3133 * saving each result as a new list[].
3135 static int perform_glob(o_string *o, int n)
3141 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3143 return o_save_ptr_helper(o, n);
3144 pattern = o->data + o_get_last_ptr(o, n);
3145 debug_printf_glob("glob pattern '%s'\n", pattern);
3146 if (!glob_needed(pattern)) {
3148 /* unbackslash last string in o in place, fix length */
3149 o->length = unbackslash(pattern) - o->data;
3150 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3151 return o_save_ptr_helper(o, n);
3154 memset(&globdata, 0, sizeof(globdata));
3155 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3156 * If we glob "*.\*" and don't find anything, we need
3157 * to fall back to using literal "*.*", but GLOB_NOCHECK
3158 * will return "*.\*"!
3160 gr = glob(pattern, 0, NULL, &globdata);
3161 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3163 if (gr == GLOB_NOMATCH) {
3164 globfree(&globdata);
3167 if (gr == GLOB_NOSPACE)
3168 bb_error_msg_and_die(bb_msg_memory_exhausted);
3169 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3170 * but we didn't specify it. Paranoia again. */
3171 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3173 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3174 char **argv = globdata.gl_pathv;
3175 /* "forget" pattern in o */
3176 o->length = pattern - o->data;
3178 o_addstr_with_NUL(o, *argv);
3179 n = o_save_ptr_helper(o, n);
3185 globfree(&globdata);
3187 debug_print_list("perform_glob returning", o, n);
3191 #endif /* !HUSH_BRACE_EXPANSION */
3193 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3194 * Otherwise, just finish current list[] and start new */
3195 static int o_save_ptr(o_string *o, int n)
3197 if (o->o_expflags & EXP_FLAG_GLOB) {
3198 /* If o->has_empty_slot, list[n] was already globbed
3199 * (if it was requested back then when it was filled)
3200 * so don't do that again! */
3201 if (!o->has_empty_slot)
3202 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3204 return o_save_ptr_helper(o, n);
3207 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3208 static char **o_finalize_list(o_string *o, int n)
3213 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3215 debug_print_list("finalized", o, n);
3216 debug_printf_expand("finalized n:%d\n", n);
3217 list = (char**)o->data;
3218 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3222 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3227 static void free_pipe_list(struct pipe *pi);
3229 /* Returns pi->next - next pipe in the list */
3230 static struct pipe *free_pipe(struct pipe *pi)
3235 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3236 for (i = 0; i < pi->num_cmds; i++) {
3237 struct command *command;
3238 struct redir_struct *r, *rnext;
3240 command = &pi->cmds[i];
3241 debug_printf_clean(" command %d:\n", i);
3242 if (command->argv) {
3246 for (a = 0, p = command->argv; *p; a++, p++) {
3247 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3250 free_strings(command->argv);
3251 //command->argv = NULL;
3253 /* not "else if": on syntax error, we may have both! */
3254 if (command->group) {
3255 debug_printf_clean(" begin group (cmd_type:%d)\n",
3257 free_pipe_list(command->group);
3258 debug_printf_clean(" end group\n");
3259 //command->group = NULL;
3261 /* else is crucial here.
3262 * If group != NULL, child_func is meaningless */
3263 #if ENABLE_HUSH_FUNCTIONS
3264 else if (command->child_func) {
3265 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3266 command->child_func->parent_cmd = NULL;
3270 free(command->group_as_string);
3271 //command->group_as_string = NULL;
3273 for (r = command->redirects; r; r = rnext) {
3274 debug_printf_clean(" redirect %d%s",
3275 r->rd_fd, redir_table[r->rd_type].descrip);
3276 /* guard against the case >$FOO, where foo is unset or blank */
3277 if (r->rd_filename) {
3278 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3279 free(r->rd_filename);
3280 //r->rd_filename = NULL;
3282 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3286 //command->redirects = NULL;
3288 free(pi->cmds); /* children are an array, they get freed all at once */
3292 //pi->cmdtext = NULL;
3300 static void free_pipe_list(struct pipe *pi)
3304 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3306 debug_printf_clean("pipe followup code %d\n", pi->followup);
3312 /*** Parsing routines ***/
3314 #ifndef debug_print_tree
3315 static void debug_print_tree(struct pipe *pi, int lvl)
3317 static const char *const PIPE[] = {
3323 static const char *RES[] = {
3324 [RES_NONE ] = "NONE" ,
3327 [RES_THEN ] = "THEN" ,
3328 [RES_ELIF ] = "ELIF" ,
3329 [RES_ELSE ] = "ELSE" ,
3332 # if ENABLE_HUSH_LOOPS
3333 [RES_FOR ] = "FOR" ,
3334 [RES_WHILE] = "WHILE",
3335 [RES_UNTIL] = "UNTIL",
3337 [RES_DONE ] = "DONE" ,
3339 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3342 # if ENABLE_HUSH_CASE
3343 [RES_CASE ] = "CASE" ,
3344 [RES_CASE_IN ] = "CASE_IN" ,
3345 [RES_MATCH] = "MATCH",
3346 [RES_CASE_BODY] = "CASE_BODY",
3347 [RES_ESAC ] = "ESAC" ,
3349 [RES_XXXX ] = "XXXX" ,
3350 [RES_SNTX ] = "SNTX" ,
3352 static const char *const CMDTYPE[] = {
3356 # if ENABLE_HUSH_FUNCTIONS
3365 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3366 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3368 while (prn < pi->num_cmds) {
3369 struct command *command = &pi->cmds[prn];
3370 char **argv = command->argv;
3372 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3374 command->assignment_cnt);
3375 if (command->group) {
3376 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3377 CMDTYPE[command->cmd_type],
3380 , " group_as_string:", command->group_as_string
3385 debug_print_tree(command->group, lvl+1);
3389 if (argv) while (*argv) {
3390 fdprintf(2, " '%s'", *argv);
3400 #endif /* debug_print_tree */
3402 static struct pipe *new_pipe(void)
3405 pi = xzalloc(sizeof(struct pipe));
3406 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3410 /* Command (member of a pipe) is complete, or we start a new pipe
3411 * if ctx->command is NULL.
3412 * No errors possible here.
3414 static int done_command(struct parse_context *ctx)
3416 /* The command is really already in the pipe structure, so
3417 * advance the pipe counter and make a new, null command. */
3418 struct pipe *pi = ctx->pipe;
3419 struct command *command = ctx->command;
3421 #if 0 /* Instead we emit error message at run time */
3422 if (ctx->pending_redirect) {
3423 /* For example, "cmd >" (no filename to redirect to) */
3424 syntax_error("invalid redirect");
3425 ctx->pending_redirect = NULL;
3430 if (IS_NULL_CMD(command)) {
3431 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3435 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3436 //debug_print_tree(ctx->list_head, 20);
3438 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3441 /* Only real trickiness here is that the uncommitted
3442 * command structure is not counted in pi->num_cmds. */
3443 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3444 ctx->command = command = &pi->cmds[pi->num_cmds];
3446 memset(command, 0, sizeof(*command));
3447 return pi->num_cmds; /* used only for 0/nonzero check */
3450 static void done_pipe(struct parse_context *ctx, pipe_style type)
3454 debug_printf_parse("done_pipe entered, followup %d\n", type);
3455 /* Close previous command */
3456 not_null = done_command(ctx);
3458 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3459 ctx->ctx_inverted = 0;
3460 ctx->pipe->res_word = ctx->ctx_res_w;
3462 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3463 /* Necessary since && and || have precedence over &:
3464 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3465 * in a backgrounded subshell.
3468 struct command *command;
3470 /* Is this actually this construct, all pipes end with && or ||? */
3471 pi = ctx->list_head;
3472 while (pi != ctx->pipe) {
3473 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3478 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3479 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3480 pi = xzalloc(sizeof(*pi));
3481 pi->followup = PIPE_BG;
3483 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3484 command = &pi->cmds[0];
3485 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3486 command->cmd_type = CMD_NORMAL;
3487 command->group = ctx->list_head;
3489 command->group_as_string = xstrndup(
3490 ctx->as_string.data,
3491 ctx->as_string.length - 1 /* do not copy last char, "&" */
3494 /* Replace all pipes in ctx with one newly created */
3495 ctx->list_head = ctx->pipe = pi;
3498 ctx->pipe->followup = type;
3501 /* Without this check, even just <enter> on command line generates
3502 * tree of three NOPs (!). Which is harmless but annoying.
3503 * IOW: it is safe to do it unconditionally. */
3506 || ctx->ctx_res_w == RES_FI
3508 #if ENABLE_HUSH_LOOPS
3509 || ctx->ctx_res_w == RES_DONE
3510 || ctx->ctx_res_w == RES_FOR
3511 || ctx->ctx_res_w == RES_IN
3513 #if ENABLE_HUSH_CASE
3514 || ctx->ctx_res_w == RES_ESAC
3518 debug_printf_parse("done_pipe: adding new pipe: "
3519 "not_null:%d ctx->ctx_res_w:%d\n",
3520 not_null, ctx->ctx_res_w);
3522 ctx->pipe->next = new_p;
3524 /* RES_THEN, RES_DO etc are "sticky" -
3525 * they remain set for pipes inside if/while.
3526 * This is used to control execution.
3527 * RES_FOR and RES_IN are NOT sticky (needed to support
3528 * cases where variable or value happens to match a keyword):
3530 #if ENABLE_HUSH_LOOPS
3531 if (ctx->ctx_res_w == RES_FOR
3532 || ctx->ctx_res_w == RES_IN)
3533 ctx->ctx_res_w = RES_NONE;
3535 #if ENABLE_HUSH_CASE
3536 if (ctx->ctx_res_w == RES_MATCH)
3537 ctx->ctx_res_w = RES_CASE_BODY;
3538 if (ctx->ctx_res_w == RES_CASE)
3539 ctx->ctx_res_w = RES_CASE_IN;
3541 ctx->command = NULL; /* trick done_command below */
3542 /* Create the memory for command, roughly:
3543 * ctx->pipe->cmds = new struct command;
3544 * ctx->command = &ctx->pipe->cmds[0];
3547 //debug_print_tree(ctx->list_head, 10);
3549 debug_printf_parse("done_pipe return\n");
3552 static void initialize_context(struct parse_context *ctx)
3554 memset(ctx, 0, sizeof(*ctx));
3555 ctx->pipe = ctx->list_head = new_pipe();
3556 /* Create the memory for command, roughly:
3557 * ctx->pipe->cmds = new struct command;
3558 * ctx->command = &ctx->pipe->cmds[0];
3563 /* If a reserved word is found and processed, parse context is modified
3564 * and 1 is returned.
3567 struct reserved_combo {
3570 unsigned char assignment_flag;
3574 FLAG_END = (1 << RES_NONE ),
3576 FLAG_IF = (1 << RES_IF ),
3577 FLAG_THEN = (1 << RES_THEN ),
3578 FLAG_ELIF = (1 << RES_ELIF ),
3579 FLAG_ELSE = (1 << RES_ELSE ),
3580 FLAG_FI = (1 << RES_FI ),
3582 # if ENABLE_HUSH_LOOPS
3583 FLAG_FOR = (1 << RES_FOR ),
3584 FLAG_WHILE = (1 << RES_WHILE),
3585 FLAG_UNTIL = (1 << RES_UNTIL),
3586 FLAG_DO = (1 << RES_DO ),
3587 FLAG_DONE = (1 << RES_DONE ),
3588 FLAG_IN = (1 << RES_IN ),
3590 # if ENABLE_HUSH_CASE
3591 FLAG_MATCH = (1 << RES_MATCH),
3592 FLAG_ESAC = (1 << RES_ESAC ),
3594 FLAG_START = (1 << RES_XXXX ),
3597 static const struct reserved_combo* match_reserved_word(o_string *word)
3599 /* Mostly a list of accepted follow-up reserved words.
3600 * FLAG_END means we are done with the sequence, and are ready
3601 * to turn the compound list into a command.
3602 * FLAG_START means the word must start a new compound list.
3604 static const struct reserved_combo reserved_list[] = {
3606 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3607 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3608 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3609 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3610 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3611 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3613 # if ENABLE_HUSH_LOOPS
3614 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3615 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3616 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3617 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3618 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3619 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3621 # if ENABLE_HUSH_CASE
3622 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3623 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3626 const struct reserved_combo *r;
3628 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3629 if (strcmp(word->data, r->literal) == 0)
3634 /* Return 0: not a keyword, 1: keyword
3636 static int reserved_word(o_string *word, struct parse_context *ctx)
3638 # if ENABLE_HUSH_CASE
3639 static const struct reserved_combo reserved_match = {
3640 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3643 const struct reserved_combo *r;
3645 if (word->has_quoted_part)
3647 r = match_reserved_word(word);
3651 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3652 # if ENABLE_HUSH_CASE
3653 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3654 /* "case word IN ..." - IN part starts first MATCH part */
3655 r = &reserved_match;
3658 if (r->flag == 0) { /* '!' */
3659 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3660 syntax_error("! ! command");
3661 ctx->ctx_res_w = RES_SNTX;
3663 ctx->ctx_inverted = 1;
3666 if (r->flag & FLAG_START) {
3667 struct parse_context *old;
3669 old = xmemdup(ctx, sizeof(*ctx));
3670 debug_printf_parse("push stack %p\n", old);
3671 initialize_context(ctx);
3673 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3674 syntax_error_at(word->data);
3675 ctx->ctx_res_w = RES_SNTX;
3678 /* "{...} fi" is ok. "{...} if" is not
3680 * if { echo foo; } then { echo bar; } fi */
3681 if (ctx->command->group)
3682 done_pipe(ctx, PIPE_SEQ);
3685 ctx->ctx_res_w = r->res;
3686 ctx->old_flag = r->flag;
3687 word->o_assignment = r->assignment_flag;
3688 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3690 if (ctx->old_flag & FLAG_END) {
3691 struct parse_context *old;
3693 done_pipe(ctx, PIPE_SEQ);
3694 debug_printf_parse("pop stack %p\n", ctx->stack);
3696 old->command->group = ctx->list_head;
3697 old->command->cmd_type = CMD_NORMAL;
3699 /* At this point, the compound command's string is in
3700 * ctx->as_string... except for the leading keyword!
3701 * Consider this example: "echo a | if true; then echo a; fi"
3702 * ctx->as_string will contain "true; then echo a; fi",
3703 * with "if " remaining in old->as_string!
3707 int len = old->as_string.length;
3708 /* Concatenate halves */
3709 o_addstr(&old->as_string, ctx->as_string.data);
3710 o_free_unsafe(&ctx->as_string);
3711 /* Find where leading keyword starts in first half */
3712 str = old->as_string.data + len;
3713 if (str > old->as_string.data)
3714 str--; /* skip whitespace after keyword */
3715 while (str > old->as_string.data && isalpha(str[-1]))
3717 /* Ugh, we're done with this horrid hack */
3718 old->command->group_as_string = xstrdup(str);
3719 debug_printf_parse("pop, remembering as:'%s'\n",
3720 old->command->group_as_string);
3723 *ctx = *old; /* physical copy */
3728 #endif /* HAS_KEYWORDS */
3730 /* Word is complete, look at it and update parsing context.
3731 * Normal return is 0. Syntax errors return 1.
3732 * Note: on return, word is reset, but not o_free'd!
3734 static int done_word(o_string *word, struct parse_context *ctx)
3736 struct command *command = ctx->command;
3738 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3739 if (word->length == 0 && !word->has_quoted_part) {
3740 debug_printf_parse("done_word return 0: true null, ignored\n");
3744 if (ctx->pending_redirect) {
3745 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3746 * only if run as "bash", not "sh" */
3747 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3749 * ...the word that follows the redirection operator
3750 * shall be subjected to tilde expansion, parameter expansion,
3751 * command substitution, arithmetic expansion, and quote
3752 * removal. Pathname expansion shall not be performed
3753 * on the word by a non-interactive shell; an interactive
3754 * shell may perform it, but shall do so only when
3755 * the expansion would result in one word."
3757 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3758 /* Cater for >\file case:
3759 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3760 * Same with heredocs:
3761 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3763 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3764 unbackslash(ctx->pending_redirect->rd_filename);
3765 /* Is it <<"HEREDOC"? */
3766 if (word->has_quoted_part) {
3767 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3770 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3771 ctx->pending_redirect = NULL;
3774 # if ENABLE_HUSH_CASE
3775 if (ctx->ctx_dsemicolon
3776 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3778 /* already done when ctx_dsemicolon was set to 1: */
3779 /* ctx->ctx_res_w = RES_MATCH; */
3780 ctx->ctx_dsemicolon = 0;
3783 if (!command->argv /* if it's the first word... */
3784 # if ENABLE_HUSH_LOOPS
3785 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3786 && ctx->ctx_res_w != RES_IN
3788 # if ENABLE_HUSH_CASE
3789 && ctx->ctx_res_w != RES_CASE
3792 int reserved = reserved_word(word, ctx);
3793 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3795 o_reset_to_empty_unquoted(word);
3796 debug_printf_parse("done_word return %d\n",
3797 (ctx->ctx_res_w == RES_SNTX));
3798 return (ctx->ctx_res_w == RES_SNTX);
3801 if (strcmp(word->data, "[[") == 0) {
3802 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3808 if (command->group) {
3809 /* "{ echo foo; } echo bar" - bad */
3810 syntax_error_at(word->data);
3811 debug_printf_parse("done_word return 1: syntax error, "
3812 "groups and arglists don't mix\n");
3816 /* If this word wasn't an assignment, next ones definitely
3817 * can't be assignments. Even if they look like ones. */
3818 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3819 && word->o_assignment != WORD_IS_KEYWORD
3821 word->o_assignment = NOT_ASSIGNMENT;
3823 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3824 command->assignment_cnt++;
3825 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3827 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3828 word->o_assignment = MAYBE_ASSIGNMENT;
3830 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3832 if (word->has_quoted_part
3833 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3834 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3835 /* (otherwise it's known to be not empty and is already safe) */
3837 /* exclude "$@" - it can expand to no word despite "" */
3838 char *p = word->data;
3839 while (p[0] == SPECIAL_VAR_SYMBOL
3840 && (p[1] & 0x7f) == '@'
3841 && p[2] == SPECIAL_VAR_SYMBOL
3846 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3847 debug_print_strings("word appended to argv", command->argv);
3850 #if ENABLE_HUSH_LOOPS
3851 if (ctx->ctx_res_w == RES_FOR) {
3852 if (word->has_quoted_part
3853 || !is_well_formed_var_name(command->argv[0], '\0')
3855 /* bash says just "not a valid identifier" */
3856 syntax_error("not a valid identifier in for");
3859 /* Force FOR to have just one word (variable name) */
3860 /* NB: basically, this makes hush see "for v in ..."
3861 * syntax as if it is "for v; in ...". FOR and IN become
3862 * two pipe structs in parse tree. */
3863 done_pipe(ctx, PIPE_SEQ);
3866 #if ENABLE_HUSH_CASE
3867 /* Force CASE to have just one word */
3868 if (ctx->ctx_res_w == RES_CASE) {
3869 done_pipe(ctx, PIPE_SEQ);
3873 o_reset_to_empty_unquoted(word);
3875 debug_printf_parse("done_word return 0\n");
3880 /* Peek ahead in the input to find out if we have a "&n" construct,
3881 * as in "2>&1", that represents duplicating a file descriptor.
3883 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3884 * REDIRFD_SYNTAX_ERR if syntax error,
3885 * REDIRFD_TO_FILE if no & was seen,
3886 * or the number found.
3889 #define parse_redir_right_fd(as_string, input) \
3890 parse_redir_right_fd(input)
3892 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3898 return REDIRFD_TO_FILE;
3900 ch = i_getch(input); /* get the & */
3901 nommu_addchr(as_string, ch);
3904 ch = i_getch(input);
3905 nommu_addchr(as_string, ch);
3906 return REDIRFD_CLOSE;
3910 while (ch != EOF && isdigit(ch)) {
3911 d = d*10 + (ch-'0');
3913 ch = i_getch(input);
3914 nommu_addchr(as_string, ch);
3919 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3921 bb_error_msg("ambiguous redirect");
3922 return REDIRFD_SYNTAX_ERR;
3925 /* Return code is 0 normal, 1 if a syntax error is detected
3927 static int parse_redirect(struct parse_context *ctx,
3930 struct in_str *input)
3932 struct command *command = ctx->command;
3933 struct redir_struct *redir;
3934 struct redir_struct **redirp;
3937 dup_num = REDIRFD_TO_FILE;
3938 if (style != REDIRECT_HEREDOC) {
3939 /* Check for a '>&1' type redirect */
3940 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3941 if (dup_num == REDIRFD_SYNTAX_ERR)
3944 int ch = i_peek(input);
3945 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3946 if (dup_num) { /* <<-... */
3947 ch = i_getch(input);
3948 nommu_addchr(&ctx->as_string, ch);
3953 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3954 int ch = i_peek(input);
3956 /* >|FILE redirect ("clobbering" >).
3957 * Since we do not support "set -o noclobber" yet,
3958 * >| and > are the same for now. Just eat |.
3960 ch = i_getch(input);
3961 nommu_addchr(&ctx->as_string, ch);
3965 /* Create a new redir_struct and append it to the linked list */
3966 redirp = &command->redirects;
3967 while ((redir = *redirp) != NULL) {
3968 redirp = &(redir->next);
3970 *redirp = redir = xzalloc(sizeof(*redir));
3971 /* redir->next = NULL; */
3972 /* redir->rd_filename = NULL; */
3973 redir->rd_type = style;
3974 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3976 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3977 redir_table[style].descrip);
3979 redir->rd_dup = dup_num;
3980 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3981 /* Erik had a check here that the file descriptor in question
3982 * is legit; I postpone that to "run time"
3983 * A "-" representation of "close me" shows up as a -3 here */
3984 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3985 redir->rd_fd, redir->rd_dup);
3987 #if 0 /* Instead we emit error message at run time */
3988 if (ctx->pending_redirect) {
3989 /* For example, "cmd > <file" */
3990 syntax_error("invalid redirect");
3993 /* Set ctx->pending_redirect, so we know what to do at the
3994 * end of the next parsed word. */
3995 ctx->pending_redirect = redir;
4000 /* If a redirect is immediately preceded by a number, that number is
4001 * supposed to tell which file descriptor to redirect. This routine
4002 * looks for such preceding numbers. In an ideal world this routine
4003 * needs to handle all the following classes of redirects...
4004 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
4005 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
4006 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
4007 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
4009 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
4011 * ... If n is quoted, the number shall not be recognized as part of
4012 * the redirection expression. For example:
4014 * writes the character 2 into file a"
4015 * We are getting it right by setting ->has_quoted_part on any \<char>
4017 * A -1 return means no valid number was found,
4018 * the caller should use the appropriate default for this redirection.
4020 static int redirect_opt_num(o_string *o)
4024 if (o->data == NULL)
4026 num = bb_strtou(o->data, NULL, 10);
4027 if (errno || num < 0)
4029 o_reset_to_empty_unquoted(o);
4034 #define fetch_till_str(as_string, input, word, skip_tabs) \
4035 fetch_till_str(input, word, skip_tabs)
4037 static char *fetch_till_str(o_string *as_string,
4038 struct in_str *input,
4042 o_string heredoc = NULL_O_STRING;
4044 int prev = 0; /* not \ */
4050 ch = i_getch(input);
4052 nommu_addchr(as_string, ch);
4053 if (ch == '\n' || ch == EOF) {
4055 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4056 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4057 heredoc.data[past_EOL] = '\0';
4058 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4059 return heredoc.data;
4062 /* This is a new line.
4063 * Remember position and backslash-escaping status.
4065 o_addchr(&heredoc, ch);
4068 past_EOL = heredoc.length;
4069 /* Get 1st char of next line, possibly skipping leading tabs */
4071 ch = i_getch(input);
4073 nommu_addchr(as_string, ch);
4074 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4075 /* If this immediately ended the line,
4076 * go back to end-of-line checks.
4079 goto check_heredoc_end;
4084 o_free_unsafe(&heredoc);
4087 o_addchr(&heredoc, ch);
4088 nommu_addchr(as_string, ch);
4089 if (prev == '\\' && ch == '\\')
4090 /* Correctly handle foo\\<eol> (not a line cont.) */
4091 prev = 0; /* not \ */
4097 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4098 * and load them all. There should be exactly heredoc_cnt of them.
4100 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4102 struct pipe *pi = ctx->list_head;
4104 while (pi && heredoc_cnt) {
4106 struct command *cmd = pi->cmds;
4108 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4110 cmd->argv ? cmd->argv[0] : "NONE");
4111 for (i = 0; i < pi->num_cmds; i++) {
4112 struct redir_struct *redir = cmd->redirects;
4114 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4115 i, cmd->argv ? cmd->argv[0] : "NONE");
4117 if (redir->rd_type == REDIRECT_HEREDOC) {
4120 redir->rd_type = REDIRECT_HEREDOC2;
4121 /* redir->rd_dup is (ab)used to indicate <<- */
4122 p = fetch_till_str(&ctx->as_string, input,
4123 redir->rd_filename, redir->rd_dup);
4125 syntax_error("unexpected EOF in here document");
4128 free(redir->rd_filename);
4129 redir->rd_filename = p;
4132 redir = redir->next;
4139 /* Should be 0. If it isn't, it's a parse error */
4141 bb_error_msg_and_die("heredoc BUG 2");
4147 static int run_list(struct pipe *pi);
4149 #define parse_stream(pstring, input, end_trigger) \
4150 parse_stream(input, end_trigger)
4152 static struct pipe *parse_stream(char **pstring,
4153 struct in_str *input,
4157 #if !ENABLE_HUSH_FUNCTIONS
4158 #define parse_group(dest, ctx, input, ch) \
4159 parse_group(ctx, input, ch)
4161 static int parse_group(o_string *dest, struct parse_context *ctx,
4162 struct in_str *input, int ch)
4164 /* dest contains characters seen prior to ( or {.
4165 * Typically it's empty, but for function defs,
4166 * it contains function name (without '()'). */
4167 struct pipe *pipe_list;
4169 struct command *command = ctx->command;
4171 debug_printf_parse("parse_group entered\n");
4172 #if ENABLE_HUSH_FUNCTIONS
4173 if (ch == '(' && !dest->has_quoted_part) {
4175 if (done_word(dest, ctx))
4178 goto skip; /* (... */
4179 if (command->argv[1]) { /* word word ... (... */
4180 syntax_error_unexpected_ch('(');
4183 /* it is "word(..." or "word (..." */
4185 ch = i_getch(input);
4186 while (ch == ' ' || ch == '\t');
4188 syntax_error_unexpected_ch(ch);
4191 nommu_addchr(&ctx->as_string, ch);
4193 ch = i_getch(input);
4194 while (ch == ' ' || ch == '\t' || ch == '\n');
4196 syntax_error_unexpected_ch(ch);
4199 nommu_addchr(&ctx->as_string, ch);
4200 command->cmd_type = CMD_FUNCDEF;
4205 #if 0 /* Prevented by caller */
4206 if (command->argv /* word [word]{... */
4207 || dest->length /* word{... */
4208 || dest->has_quoted_part /* ""{... */
4211 debug_printf_parse("parse_group return 1: "
4212 "syntax error, groups and arglists don't mix\n");
4217 #if ENABLE_HUSH_FUNCTIONS
4223 command->cmd_type = CMD_SUBSHELL;
4225 /* bash does not allow "{echo...", requires whitespace */
4227 if (ch != ' ' && ch != '\t' && ch != '\n'
4228 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4230 syntax_error_unexpected_ch(ch);
4234 ch = i_getch(input);
4235 nommu_addchr(&ctx->as_string, ch);
4241 # define as_string NULL
4243 char *as_string = NULL;
4245 pipe_list = parse_stream(&as_string, input, endch);
4248 o_addstr(&ctx->as_string, as_string);
4250 /* empty ()/{} or parse error? */
4251 if (!pipe_list || pipe_list == ERR_PTR) {
4252 /* parse_stream already emitted error msg */
4255 debug_printf_parse("parse_group return 1: "
4256 "parse_stream returned %p\n", pipe_list);
4259 command->group = pipe_list;
4261 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4262 command->group_as_string = as_string;
4263 debug_printf_parse("end of group, remembering as:'%s'\n",
4264 command->group_as_string);
4268 debug_printf_parse("parse_group return 0\n");
4270 /* command remains "open", available for possible redirects */
4273 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4278 ch = i_getch(input);
4281 ch2 = i_peek(input);
4284 /* backslash+newline, skip it */
4289 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4297 ch2 = i_peek2(input);
4300 /* backslash+newline, skip it */
4306 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4307 /* Subroutines for copying $(...) and `...` things */
4308 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4310 static int add_till_single_quote(o_string *dest, struct in_str *input)
4313 int ch = i_getch(input);
4315 syntax_error_unterm_ch('\'');
4323 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4324 static int add_till_double_quote(o_string *dest, struct in_str *input)
4327 int ch = i_getch(input);
4329 syntax_error_unterm_ch('"');
4334 if (ch == '\\') { /* \x. Copy both chars. */
4336 ch = i_getch(input);
4340 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4345 //if (ch == '$') ...
4348 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4350 * "Within the backquoted style of command substitution, backslash
4351 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4352 * The search for the matching backquote shall be satisfied by the first
4353 * backquote found without a preceding backslash; during this search,
4354 * if a non-escaped backquote is encountered within a shell comment,
4355 * a here-document, an embedded command substitution of the $(command)
4356 * form, or a quoted string, undefined results occur. A single-quoted
4357 * or double-quoted string that begins, but does not end, within the
4358 * "`...`" sequence produces undefined results."
4360 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4362 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4365 int ch = i_getch(input);
4369 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4370 ch = i_getch(input);
4374 && (!in_dquote || ch != '"')
4376 o_addchr(dest, '\\');
4380 syntax_error_unterm_ch('`');
4386 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4387 * quoting and nested ()s.
4388 * "With the $(command) style of command substitution, all characters
4389 * following the open parenthesis to the matching closing parenthesis
4390 * constitute the command. Any valid shell script can be used for command,
4391 * except a script consisting solely of redirections which produces
4392 * unspecified results."
4394 * echo $(echo '(TEST)' BEST) (TEST) BEST
4395 * echo $(echo 'TEST)' BEST) TEST) BEST
4396 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4398 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4399 * can contain arbitrary constructs, just like $(cmd).
4400 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4401 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4403 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4404 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4407 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4408 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4409 char end_char2 = end_ch >> 8;
4411 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4414 ch = i_getch(input);
4416 syntax_error_unterm_ch(end_ch);
4420 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4426 /* we look for closing )) of $((EXPR)) */
4427 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4428 i_getch(input); /* eat second ')' */
4433 if (ch == '(' || ch == '{') {
4434 ch = (ch == '(' ? ')' : '}');
4435 if (!add_till_closing_bracket(dest, input, ch))
4441 if (!add_till_single_quote(dest, input))
4447 if (!add_till_double_quote(dest, input))
4453 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4459 /* \x. Copy verbatim. Important for \(, \) */
4460 ch = i_getch(input);
4462 syntax_error_unterm_ch(')');
4467 /* "backslash+newline", ignore both */
4468 o_delchr(dest); /* undo insertion of '\' */
4478 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4480 /* Return code: 0 for OK, 1 for syntax error */
4482 #define parse_dollar(as_string, dest, input, quote_mask) \
4483 parse_dollar(dest, input, quote_mask)
4484 #define as_string NULL
4486 static int parse_dollar(o_string *as_string,
4488 struct in_str *input, unsigned char quote_mask)
4490 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4492 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4494 ch = i_getch(input);
4495 nommu_addchr(as_string, ch);
4497 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4499 debug_printf_parse(": '%c'\n", ch);
4500 o_addchr(dest, ch | quote_mask);
4502 ch = i_peek_and_eat_bkslash_nl(input);
4503 if (!isalnum(ch) && ch != '_') {
4504 /* End of variable name reached */
4507 ch = i_getch(input);
4508 nommu_addchr(as_string, ch);
4510 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4511 } else if (isdigit(ch)) {
4513 ch = i_getch(input);
4514 nommu_addchr(as_string, ch);
4515 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4516 debug_printf_parse(": '%c'\n", ch);
4517 o_addchr(dest, ch | quote_mask);
4518 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4519 } else switch (ch) {
4521 case '!': /* last bg pid */
4522 case '?': /* last exit code */
4523 case '#': /* number of args */
4524 case '*': /* args */
4525 case '@': /* args */
4526 goto make_one_char_var;
4530 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4532 ch = i_getch(input); /* eat '{' */
4533 nommu_addchr(as_string, ch);
4535 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4536 /* It should be ${?}, or ${#var},
4537 * or even ${?+subst} - operator acting on a special variable,
4538 * or the beginning of variable name.
4541 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4544 syntax_error_unterm_str("${name}");
4545 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4548 nommu_addchr(as_string, ch);
4552 /* It's possible to just call add_till_closing_bracket() at this point.
4553 * However, this regresses some of our testsuite cases
4554 * which check invalid constructs like ${%}.
4555 * Oh well... let's check that the var name part is fine... */
4561 debug_printf_parse(": '%c'\n", ch);
4563 ch = i_getch(input);
4564 nommu_addchr(as_string, ch);
4568 if (!isalnum(ch) && ch != '_') {
4570 unsigned char last_ch;
4571 /* handle parameter expansions
4572 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4574 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4575 if (len_single_ch != '#'
4576 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4577 || i_peek(input) != '}'
4579 goto bad_dollar_syntax;
4581 /* else: it's "length of C" ${#C} op,
4582 * where C is a single char
4583 * special var name, e.g. ${#!}.
4586 /* Eat everything until closing '}' (or ':') */
4590 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4592 /* It's ${var:N[:M]} thing */
4593 end_ch = '}' * 0x100 + ':';
4595 if (BASH_PATTERN_SUBST
4598 /* It's ${var/[/]pattern[/repl]} thing */
4599 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4601 nommu_addchr(as_string, '/');
4604 end_ch = '}' * 0x100 + '/';
4610 #if ENABLE_HUSH_DOLLAR_OPS
4611 last_ch = add_till_closing_bracket(dest, input, end_ch);
4612 if (last_ch == 0) /* error? */
4615 #error Simple code to only allow ${var} is not implemented
4618 o_addstr(as_string, dest->data + pos);
4619 o_addchr(as_string, last_ch);
4622 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4623 && (end_ch & 0xff00)
4625 /* close the first block: */
4626 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4627 /* while parsing N from ${var:N[:M]}
4628 * or pattern from ${var/[/]pattern[/repl]} */
4629 if ((end_ch & 0xff) == last_ch) {
4630 /* got ':' or '/'- parse the rest */
4635 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4636 /* it's ${var:N} - emulate :999999999 */
4637 o_addstr(dest, "999999999");
4638 } /* else: it's ${var/[/]pattern} */
4642 len_single_ch = 0; /* it can't be ${#C} op */
4644 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4647 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4651 ch = i_getch(input);
4652 nommu_addchr(as_string, ch);
4653 # if ENABLE_FEATURE_SH_MATH
4654 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4655 ch = i_getch(input);
4656 nommu_addchr(as_string, ch);
4657 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4658 o_addchr(dest, /*quote_mask |*/ '+');
4661 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4662 return 0; /* error */
4664 o_addstr(as_string, dest->data + pos);
4665 o_addchr(as_string, ')');
4666 o_addchr(as_string, ')');
4668 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4672 # if ENABLE_HUSH_TICK
4673 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4674 o_addchr(dest, quote_mask | '`');
4677 if (!add_till_closing_bracket(dest, input, ')'))
4678 return 0; /* error */
4680 o_addstr(as_string, dest->data + pos);
4681 o_addchr(as_string, ')');
4683 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4689 ch = i_getch(input);
4690 nommu_addchr(as_string, ch);
4691 ch = i_peek_and_eat_bkslash_nl(input);
4692 if (isalnum(ch)) { /* it's $_name or $_123 */
4697 /* TODO: $_ and $-: */
4698 /* $_ Shell or shell script name; or last argument of last command
4699 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4700 * but in command's env, set to full pathname used to invoke it */
4701 /* $- Option flags set by set builtin or shell options (-i etc) */
4703 o_addQchr(dest, '$');
4705 debug_printf_parse("parse_dollar return 1 (ok)\n");
4711 # if BASH_PATTERN_SUBST
4712 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4713 encode_string(dest, input, dquote_end, process_bkslash)
4715 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4716 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4717 encode_string(dest, input, dquote_end)
4719 #define as_string NULL
4723 # if BASH_PATTERN_SUBST
4724 /* all parameters are needed, no macro tricks */
4726 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4727 encode_string(as_string, dest, input, dquote_end)
4730 static int encode_string(o_string *as_string,
4732 struct in_str *input,
4734 int process_bkslash)
4736 #if !BASH_PATTERN_SUBST
4737 const int process_bkslash = 1;
4743 ch = i_getch(input);
4745 nommu_addchr(as_string, ch);
4746 if (ch == dquote_end) { /* may be only '"' or EOF */
4747 debug_printf_parse("encode_string return 1 (ok)\n");
4750 /* note: can't move it above ch == dquote_end check! */
4752 syntax_error_unterm_ch('"');
4753 return 0; /* error */
4757 next = i_peek(input);
4759 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4760 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4761 if (process_bkslash && ch == '\\') {
4763 syntax_error("\\<eof>");
4767 * "The backslash retains its special meaning [in "..."]
4768 * only when followed by one of the following characters:
4769 * $, `, ", \, or <newline>. A double quote may be quoted
4770 * within double quotes by preceding it with a backslash."
4771 * NB: in (unquoted) heredoc, above does not apply to ",
4772 * therefore we check for it by "next == dquote_end" cond.
4774 if (next == dquote_end || strchr("$`\\\n", next)) {
4775 ch = i_getch(input); /* eat next */
4777 goto again; /* skip \<newline> */
4778 } /* else: ch remains == '\\', and we double it below: */
4779 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4780 nommu_addchr(as_string, ch);
4784 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4785 debug_printf_parse("encode_string return 0: "
4786 "parse_dollar returned 0 (error)\n");
4791 #if ENABLE_HUSH_TICK
4793 //unsigned pos = dest->length;
4794 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4795 o_addchr(dest, 0x80 | '`');
4796 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4797 return 0; /* error */
4798 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4799 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4803 o_addQchr(dest, ch);
4809 * Scan input until EOF or end_trigger char.
4810 * Return a list of pipes to execute, or NULL on EOF
4811 * or if end_trigger character is met.
4812 * On syntax error, exit if shell is not interactive,
4813 * reset parsing machinery and start parsing anew,
4814 * or return ERR_PTR.
4816 static struct pipe *parse_stream(char **pstring,
4817 struct in_str *input,
4820 struct parse_context ctx;
4821 o_string dest = NULL_O_STRING;
4824 /* Single-quote triggers a bypass of the main loop until its mate is
4825 * found. When recursing, quote state is passed in via dest->o_expflags.
4827 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4828 end_trigger ? end_trigger : 'X');
4831 /* If very first arg is "" or '', dest.data may end up NULL.
4832 * Preventing this: */
4833 o_addchr(&dest, '\0');
4836 /* We used to separate words on $IFS here. This was wrong.
4837 * $IFS is used only for word splitting when $var is expanded,
4838 * here we should use blank chars as separators, not $IFS
4841 if (MAYBE_ASSIGNMENT != 0)
4842 dest.o_assignment = MAYBE_ASSIGNMENT;
4843 initialize_context(&ctx);
4846 const char *is_blank;
4847 const char *is_special;
4851 redir_type redir_style;
4853 ch = i_getch(input);
4854 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4855 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4860 syntax_error_unterm_str("here document");
4863 if (end_trigger == ')') {
4864 syntax_error_unterm_ch('(');
4867 if (end_trigger == '}') {
4868 syntax_error_unterm_ch('{');
4872 if (done_word(&dest, &ctx)) {
4876 done_pipe(&ctx, PIPE_SEQ);
4878 /* If we got nothing... */
4879 /* (this makes bare "&" cmd a no-op.
4880 * bash says: "syntax error near unexpected token '&'") */
4881 if (pi->num_cmds == 0
4882 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4888 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4890 *pstring = ctx.as_string.data;
4892 o_free_unsafe(&ctx.as_string);
4895 debug_printf_parse("parse_stream return %p\n", pi);
4898 nommu_addchr(&ctx.as_string, ch);
4902 next = i_peek(input);
4904 is_special = "{}<>;&|()#'" /* special outside of "str" */
4905 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4906 /* Are { and } special here? */
4907 if (ctx.command->argv /* word [word]{... - non-special */
4908 || dest.length /* word{... - non-special */
4909 || dest.has_quoted_part /* ""{... - non-special */
4910 || (next != ';' /* }; - special */
4911 && next != ')' /* }) - special */
4912 && next != '(' /* {( - special */
4913 && next != '&' /* }& and }&& ... - special */
4914 && next != '|' /* }|| ... - special */
4915 && !strchr(defifs, next) /* {word - non-special */
4918 /* They are not special, skip "{}" */
4921 is_special = strchr(is_special, ch);
4922 is_blank = strchr(defifs, ch);
4924 if (!is_special && !is_blank) { /* ordinary char */
4926 o_addQchr(&dest, ch);
4927 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4928 || dest.o_assignment == WORD_IS_KEYWORD)
4930 && is_well_formed_var_name(dest.data, '=')
4932 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4933 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4939 if (done_word(&dest, &ctx)) {
4943 /* Is this a case when newline is simply ignored?
4945 * "cmd | <newline> cmd ..."
4946 * "case ... in <newline> word) ..."
4948 if (IS_NULL_CMD(ctx.command)
4949 && dest.length == 0 && !dest.has_quoted_part
4951 /* This newline can be ignored. But...
4952 * Without check #1, interactive shell
4953 * ignores even bare <newline>,
4954 * and shows the continuation prompt:
4955 * ps1_prompt$ <enter>
4956 * ps2> _ <=== wrong, should be ps1
4957 * Without check #2, "cmd & <newline>"
4958 * is similarly mistreated.
4959 * (BTW, this makes "cmd & cmd"
4960 * and "cmd && cmd" non-orthogonal.
4961 * Really, ask yourself, why
4962 * "cmd && <newline>" doesn't start
4963 * cmd but waits for more input?
4964 * The only reason is that it might be
4965 * a "cmd1 && <nl> cmd2 &" construct,
4966 * cmd1 may need to run in BG).
4968 struct pipe *pi = ctx.list_head;
4969 if (pi->num_cmds != 0 /* check #1 */
4970 && pi->followup != PIPE_BG /* check #2 */
4975 /* Treat newline as a command separator. */
4976 done_pipe(&ctx, PIPE_SEQ);
4977 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4979 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4984 dest.o_assignment = MAYBE_ASSIGNMENT;
4985 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4987 /* note: if (is_blank) continue;
4988 * will still trigger for us */
4992 /* "cmd}" or "cmd }..." without semicolon or &:
4993 * } is an ordinary char in this case, even inside { cmd; }
4994 * Pathological example: { ""}; } should exec "}" cmd
4997 if (dest.length != 0 /* word} */
4998 || dest.has_quoted_part /* ""} */
5002 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
5003 /* Generally, there should be semicolon: "cmd; }"
5004 * However, bash allows to omit it if "cmd" is
5005 * a group. Examples:
5008 * { echo 0 >&2 | { echo 1; } }
5009 * { while false; do :; done }
5010 * { case a in b) ;; esac }
5012 if (ctx.command->group)
5016 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
5017 /* Can't be an end of {cmd}, skip the check */
5018 goto skip_end_trigger;
5019 /* else: } does terminate a group */
5022 if (end_trigger && end_trigger == ch
5023 && (ch != ';' || heredoc_cnt == 0)
5024 #if ENABLE_HUSH_CASE
5026 || ctx.ctx_res_w != RES_MATCH
5027 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5032 /* This is technically valid:
5033 * { cat <<HERE; }; echo Ok
5037 * but we don't support this.
5038 * We require heredoc to be in enclosing {}/(),
5041 syntax_error_unterm_str("here document");
5044 if (done_word(&dest, &ctx)) {
5047 done_pipe(&ctx, PIPE_SEQ);
5048 dest.o_assignment = MAYBE_ASSIGNMENT;
5049 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5050 /* Do we sit outside of any if's, loops or case's? */
5052 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5056 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5058 *pstring = ctx.as_string.data;
5060 o_free_unsafe(&ctx.as_string);
5062 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5063 /* Example: bare "{ }", "()" */
5064 G.last_exitcode = 2; /* bash compat */
5065 syntax_error_unexpected_ch(ch);
5068 debug_printf_parse("parse_stream return %p: "
5069 "end_trigger char found\n",
5072 return ctx.list_head;
5079 /* Catch <, > before deciding whether this word is
5080 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5083 redir_fd = redirect_opt_num(&dest);
5084 if (done_word(&dest, &ctx)) {
5087 redir_style = REDIRECT_OVERWRITE;
5089 redir_style = REDIRECT_APPEND;
5090 ch = i_getch(input);
5091 nommu_addchr(&ctx.as_string, ch);
5094 else if (next == '(') {
5095 syntax_error(">(process) not supported");
5099 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5101 continue; /* back to top of while (1) */
5103 redir_fd = redirect_opt_num(&dest);
5104 if (done_word(&dest, &ctx)) {
5107 redir_style = REDIRECT_INPUT;
5109 redir_style = REDIRECT_HEREDOC;
5111 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5112 ch = i_getch(input);
5113 nommu_addchr(&ctx.as_string, ch);
5114 } else if (next == '>') {
5115 redir_style = REDIRECT_IO;
5116 ch = i_getch(input);
5117 nommu_addchr(&ctx.as_string, ch);
5120 else if (next == '(') {
5121 syntax_error("<(process) not supported");
5125 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5127 continue; /* back to top of while (1) */
5129 if (dest.length == 0 && !dest.has_quoted_part) {
5130 /* skip "#comment" */
5133 if (ch == EOF || ch == '\n')
5136 /* note: we do not add it to &ctx.as_string */
5138 nommu_addchr(&ctx.as_string, '\n');
5139 continue; /* back to top of while (1) */
5144 /* It's "\<newline>" */
5146 /* Remove trailing '\' from ctx.as_string */
5147 ctx.as_string.data[--ctx.as_string.length] = '\0';
5149 ch = i_getch(input); /* eat it */
5150 continue; /* back to top of while (1) */
5155 if (dest.o_assignment == MAYBE_ASSIGNMENT
5156 /* check that we are not in word in "a=1 2>word b=1": */
5157 && !ctx.pending_redirect
5159 /* ch is a special char and thus this word
5160 * cannot be an assignment */
5161 dest.o_assignment = NOT_ASSIGNMENT;
5162 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5165 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5168 case '#': /* non-comment #: "echo a#b" etc */
5169 o_addQchr(&dest, ch);
5173 syntax_error("\\<eof>");
5176 ch = i_getch(input);
5177 /* note: ch != '\n' (that case does not reach this place) */
5178 o_addchr(&dest, '\\');
5179 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5180 o_addchr(&dest, ch);
5181 nommu_addchr(&ctx.as_string, ch);
5182 /* Example: echo Hello \2>file
5183 * we need to know that word 2 is quoted */
5184 dest.has_quoted_part = 1;
5187 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5188 debug_printf_parse("parse_stream parse error: "
5189 "parse_dollar returned 0 (error)\n");
5194 dest.has_quoted_part = 1;
5195 if (next == '\'' && !ctx.pending_redirect) {
5196 insert_empty_quoted_str_marker:
5197 nommu_addchr(&ctx.as_string, next);
5198 i_getch(input); /* eat second ' */
5199 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5200 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5203 ch = i_getch(input);
5205 syntax_error_unterm_ch('\'');
5208 nommu_addchr(&ctx.as_string, ch);
5211 o_addqchr(&dest, ch);
5216 dest.has_quoted_part = 1;
5217 if (next == '"' && !ctx.pending_redirect)
5218 goto insert_empty_quoted_str_marker;
5219 if (dest.o_assignment == NOT_ASSIGNMENT)
5220 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5221 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5223 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5225 #if ENABLE_HUSH_TICK
5227 USE_FOR_NOMMU(unsigned pos;)
5229 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5230 o_addchr(&dest, '`');
5231 USE_FOR_NOMMU(pos = dest.length;)
5232 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5235 o_addstr(&ctx.as_string, dest.data + pos);
5236 o_addchr(&ctx.as_string, '`');
5238 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5239 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5244 #if ENABLE_HUSH_CASE
5247 if (done_word(&dest, &ctx)) {
5250 done_pipe(&ctx, PIPE_SEQ);
5251 #if ENABLE_HUSH_CASE
5252 /* Eat multiple semicolons, detect
5253 * whether it means something special */
5258 ch = i_getch(input);
5259 nommu_addchr(&ctx.as_string, ch);
5260 if (ctx.ctx_res_w == RES_CASE_BODY) {
5261 ctx.ctx_dsemicolon = 1;
5262 ctx.ctx_res_w = RES_MATCH;
5268 /* We just finished a cmd. New one may start
5269 * with an assignment */
5270 dest.o_assignment = MAYBE_ASSIGNMENT;
5271 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5274 if (done_word(&dest, &ctx)) {
5278 ch = i_getch(input);
5279 nommu_addchr(&ctx.as_string, ch);
5280 done_pipe(&ctx, PIPE_AND);
5282 done_pipe(&ctx, PIPE_BG);
5286 if (done_word(&dest, &ctx)) {
5289 #if ENABLE_HUSH_CASE
5290 if (ctx.ctx_res_w == RES_MATCH)
5291 break; /* we are in case's "word | word)" */
5293 if (next == '|') { /* || */
5294 ch = i_getch(input);
5295 nommu_addchr(&ctx.as_string, ch);
5296 done_pipe(&ctx, PIPE_OR);
5298 /* we could pick up a file descriptor choice here
5299 * with redirect_opt_num(), but bash doesn't do it.
5300 * "echo foo 2| cat" yields "foo 2". */
5305 #if ENABLE_HUSH_CASE
5306 /* "case... in [(]word)..." - skip '(' */
5307 if (ctx.ctx_res_w == RES_MATCH
5308 && ctx.command->argv == NULL /* not (word|(... */
5309 && dest.length == 0 /* not word(... */
5310 && dest.has_quoted_part == 0 /* not ""(... */
5316 if (parse_group(&dest, &ctx, input, ch) != 0) {
5321 #if ENABLE_HUSH_CASE
5322 if (ctx.ctx_res_w == RES_MATCH)
5326 /* proper use of this character is caught by end_trigger:
5327 * if we see {, we call parse_group(..., end_trigger='}')
5328 * and it will match } earlier (not here). */
5329 G.last_exitcode = 2;
5330 syntax_error_unexpected_ch(ch);
5334 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5339 G.last_exitcode = 1;
5342 struct parse_context *pctx;
5343 IF_HAS_KEYWORDS(struct parse_context *p2;)
5345 /* Clean up allocated tree.
5346 * Sample for finding leaks on syntax error recovery path.
5347 * Run it from interactive shell, watch pmap `pidof hush`.
5348 * while if false; then false; fi; do break; fi
5349 * Samples to catch leaks at execution:
5350 * while if (true | { true;}); then echo ok; fi; do break; done
5351 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5355 /* Update pipe/command counts,
5356 * otherwise freeing may miss some */
5357 done_pipe(pctx, PIPE_SEQ);
5358 debug_printf_clean("freeing list %p from ctx %p\n",
5359 pctx->list_head, pctx);
5360 debug_print_tree(pctx->list_head, 0);
5361 free_pipe_list(pctx->list_head);
5362 debug_printf_clean("freed list %p\n", pctx->list_head);
5364 o_free_unsafe(&pctx->as_string);
5366 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5370 IF_HAS_KEYWORDS(pctx = p2;)
5371 } while (HAS_KEYWORDS && pctx);
5384 /*** Execution routines ***/
5386 /* Expansion can recurse, need forward decls: */
5387 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5388 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5389 #define expand_string_to_string(str, do_unbackslash) \
5390 expand_string_to_string(str)
5392 static char *expand_string_to_string(const char *str, int do_unbackslash);
5393 #if ENABLE_HUSH_TICK
5394 static int process_command_subs(o_string *dest, const char *s);
5397 /* expand_strvec_to_strvec() takes a list of strings, expands
5398 * all variable references within and returns a pointer to
5399 * a list of expanded strings, possibly with larger number
5400 * of strings. (Think VAR="a b"; echo $VAR).
5401 * This new list is allocated as a single malloc block.
5402 * NULL-terminated list of char* pointers is at the beginning of it,
5403 * followed by strings themselves.
5404 * Caller can deallocate entire list by single free(list). */
5406 /* A horde of its helpers come first: */
5408 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5410 while (--len >= 0) {
5413 #if ENABLE_HUSH_BRACE_EXPANSION
5414 if (c == '{' || c == '}') {
5415 /* { -> \{, } -> \} */
5417 /* And now we want to add { or } and continue:
5420 * luckily, just falling through achieves this.
5426 /* \z -> \\\z; \<eol> -> \\<eol> */
5431 o_addchr(o, *str++);
5437 /* Store given string, finalizing the word and starting new one whenever
5438 * we encounter IFS char(s). This is used for expanding variable values.
5439 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5440 * Return in *ended_with_ifs:
5441 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5443 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5445 int last_is_ifs = 0;
5450 if (!*str) /* EOL - do not finalize word */
5452 word_len = strcspn(str, G.ifs);
5454 /* We have WORD_LEN leading non-IFS chars */
5455 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5456 o_addblock(output, str, word_len);
5458 /* Protect backslashes against globbing up :)
5459 * Example: "v='\*'; echo b$v" prints "b\*"
5460 * (and does not try to glob on "*")
5462 o_addblock_duplicate_backslash(output, str, word_len);
5463 /*/ Why can't we do it easier? */
5464 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5465 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5469 if (!*str) /* EOL - do not finalize word */
5473 /* We know str here points to at least one IFS char */
5475 str += strspn(str, G.ifs); /* skip IFS chars */
5476 if (!*str) /* EOL - do not finalize word */
5479 /* Start new word... but not always! */
5480 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5481 if (output->has_quoted_part
5482 /* Case "v=' a'; echo $v":
5483 * here nothing precedes the space in $v expansion,
5484 * therefore we should not finish the word
5485 * (IOW: if there *is* word to finalize, only then do it):
5487 || (n > 0 && output->data[output->length - 1])
5489 o_addchr(output, '\0');
5490 debug_print_list("expand_on_ifs", output, n);
5491 n = o_save_ptr(output, n);
5496 *ended_with_ifs = last_is_ifs;
5497 debug_print_list("expand_on_ifs[1]", output, n);
5501 /* Helper to expand $((...)) and heredoc body. These act as if
5502 * they are in double quotes, with the exception that they are not :).
5503 * Just the rules are similar: "expand only $var and `cmd`"
5505 * Returns malloced string.
5506 * As an optimization, we return NULL if expansion is not needed.
5508 #if !BASH_PATTERN_SUBST
5509 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5510 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5511 encode_then_expand_string(str)
5513 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5515 #if !BASH_PATTERN_SUBST
5516 const int do_unbackslash = 1;
5519 struct in_str input;
5520 o_string dest = NULL_O_STRING;
5522 if (!strchr(str, '$')
5523 && !strchr(str, '\\')
5524 #if ENABLE_HUSH_TICK
5525 && !strchr(str, '`')
5531 /* We need to expand. Example:
5532 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5534 setup_string_in_str(&input, str);
5535 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5536 //TODO: error check (encode_string returns 0 on error)?
5537 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5538 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5539 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5540 o_free_unsafe(&dest);
5544 #if ENABLE_FEATURE_SH_MATH
5545 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5547 arith_state_t math_state;
5551 math_state.lookupvar = get_local_var_value;
5552 math_state.setvar = set_local_var_from_halves;
5553 //math_state.endofname = endofname;
5554 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5555 res = arith(&math_state, exp_str ? exp_str : arg);
5558 *errmsg_p = math_state.errmsg;
5559 if (math_state.errmsg)
5560 msg_and_die_if_script(math_state.errmsg);
5565 #if BASH_PATTERN_SUBST
5566 /* ${var/[/]pattern[/repl]} helpers */
5567 static char *strstr_pattern(char *val, const char *pattern, int *size)
5570 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5571 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5578 /* Optimization: if "*pat" did not match the start of "string",
5579 * we know that "tring", "ring" etc will not match too:
5581 if (pattern[0] == '*')
5586 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5588 char *result = NULL;
5589 unsigned res_len = 0;
5590 unsigned repl_len = strlen(repl);
5594 char *s = strstr_pattern(val, pattern, &size);
5598 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5599 strcpy(mempcpy(result + res_len, val, s - val), repl);
5600 res_len += (s - val) + repl_len;
5601 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5607 if (*val && result) {
5608 result = xrealloc(result, res_len + strlen(val) + 1);
5609 strcpy(result + res_len, val);
5610 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5612 debug_printf_varexp("result:'%s'\n", result);
5615 #endif /* BASH_PATTERN_SUBST */
5618 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5620 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5622 const char *val = NULL;
5623 char *to_be_freed = NULL;
5628 char exp_save = exp_save; /* for compiler */
5629 char *exp_saveptr; /* points to expansion operator */
5630 char *exp_word = exp_word; /* for compiler */
5633 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5635 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5637 first_char = arg[0] = arg0 & 0x7f;
5640 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5641 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5642 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5643 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5645 /* It must be length operator: ${#var} */
5649 /* Maybe handle parameter expansion */
5650 if (exp_saveptr /* if 2nd char is one of expansion operators */
5651 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5653 /* ${?:0}, ${#[:]%0} etc */
5654 exp_saveptr = var + 1;
5656 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5657 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5659 exp_op = exp_save = *exp_saveptr;
5661 exp_word = exp_saveptr + 1;
5662 if (exp_op == ':') {
5663 exp_op = *exp_word++;
5664 //TODO: try ${var:} and ${var:bogus} in non-bash config
5666 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5668 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5673 *exp_saveptr = '\0';
5674 } /* else: it's not an expansion op, but bare ${var} */
5677 /* Look up the variable in question */
5678 if (isdigit(var[0])) {
5679 /* parse_dollar should have vetted var for us */
5680 int n = xatoi_positive(var);
5681 if (n < G.global_argc)
5682 val = G.global_argv[n];
5683 /* else val remains NULL: $N with too big N */
5687 val = utoa(G.root_pid);
5689 case '!': /* bg pid */
5690 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5692 case '?': /* exitcode */
5693 val = utoa(G.last_exitcode);
5695 case '#': /* argc */
5696 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5699 val = get_local_var_value(var);
5703 /* Handle any expansions */
5704 if (exp_op == 'L') {
5705 reinit_unicode_for_hush();
5706 debug_printf_expand("expand: length(%s)=", val);
5707 val = utoa(val ? unicode_strlen(val) : 0);
5708 debug_printf_expand("%s\n", val);
5709 } else if (exp_op) {
5710 if (exp_op == '%' || exp_op == '#') {
5711 /* Standard-mandated substring removal ops:
5712 * ${parameter%word} - remove smallest suffix pattern
5713 * ${parameter%%word} - remove largest suffix pattern
5714 * ${parameter#word} - remove smallest prefix pattern
5715 * ${parameter##word} - remove largest prefix pattern
5717 * Word is expanded to produce a glob pattern.
5718 * Then var's value is matched to it and matching part removed.
5720 if (val && val[0]) {
5724 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5725 if (exp_op == *exp_word) /* ## or %% */
5727 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5729 exp_word = exp_exp_word;
5730 /* HACK ALERT. We depend here on the fact that
5731 * G.global_argv and results of utoa and get_local_var_value
5732 * are actually in writable memory:
5733 * scan_and_match momentarily stores NULs there. */
5735 loc = scan_and_match(t, exp_word, scan_flags);
5736 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5737 // exp_op, t, exp_word, loc);
5739 if (loc) { /* match was found */
5740 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5741 val = loc; /* take right part */
5743 val = to_be_freed = xstrndup(val, loc - val); /* left */
5747 #if BASH_PATTERN_SUBST
5748 else if (exp_op == '/' || exp_op == '\\') {
5749 /* It's ${var/[/]pattern[/repl]} thing.
5750 * Note that in encoded form it has TWO parts:
5751 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5752 * and if // is used, it is encoded as \:
5753 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5755 /* Empty variable always gives nothing: */
5756 // "v=''; echo ${v/*/w}" prints "", not "w"
5757 if (val && val[0]) {
5758 /* pattern uses non-standard expansion.
5759 * repl should be unbackslashed and globbed
5760 * by the usual expansion rules:
5762 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5763 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5764 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5765 * v='a bz'; echo ${v/a*z/\z} prints "z"
5766 * (note that a*z _pattern_ is never globbed!)
5768 char *pattern, *repl, *t;
5769 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5771 pattern = xstrdup(exp_word);
5772 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5773 *p++ = SPECIAL_VAR_SYMBOL;
5775 p = strchr(p, SPECIAL_VAR_SYMBOL);
5777 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5778 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5779 /* HACK ALERT. We depend here on the fact that
5780 * G.global_argv and results of utoa and get_local_var_value
5781 * are actually in writable memory:
5782 * replace_pattern momentarily stores NULs there. */
5784 to_be_freed = replace_pattern(t,
5786 (repl ? repl : exp_word),
5788 if (to_be_freed) /* at least one replace happened */
5794 #endif /* BASH_PATTERN_SUBST */
5795 else if (exp_op == ':') {
5796 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5797 /* It's ${var:N[:M]} bashism.
5798 * Note that in encoded form it has TWO parts:
5799 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5804 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5807 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5808 *p++ = SPECIAL_VAR_SYMBOL;
5810 p = strchr(p, SPECIAL_VAR_SYMBOL);
5812 len = expand_and_evaluate_arith(exp_word, &errmsg);
5815 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5817 /* negative beg counts from the end */
5818 beg = (arith_t)strlen(val) + beg;
5819 if (beg < 0) /* ${v: -999999} is "" */
5822 debug_printf_varexp("from val:'%s'\n", val);
5824 /* in bash, len=-n means strlen()-n */
5825 len = (arith_t)strlen(val) - beg + len;
5826 if (len < 0) /* bash compat */
5827 msg_and_die_if_script("%s: substring expression < 0", var);
5829 if (len <= 0 || !val || beg >= strlen(val)) {
5833 /* Paranoia. What if user entered 9999999999999
5834 * which fits in arith_t but not int? */
5837 val = to_be_freed = xstrndup(val + beg, len);
5839 debug_printf_varexp("val:'%s'\n", val);
5840 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5841 msg_and_die_if_script("malformed ${%s:...}", var);
5844 } else { /* one of "-=+?" */
5845 /* Standard-mandated substitution ops:
5846 * ${var?word} - indicate error if unset
5847 * If var is unset, word (or a message indicating it is unset
5848 * if word is null) is written to standard error
5849 * and the shell exits with a non-zero exit status.
5850 * Otherwise, the value of var is substituted.
5851 * ${var-word} - use default value
5852 * If var is unset, word is substituted.
5853 * ${var=word} - assign and use default value
5854 * If var is unset, word is assigned to var.
5855 * In all cases, final value of var is substituted.
5856 * ${var+word} - use alternative value
5857 * If var is unset, null is substituted.
5858 * Otherwise, word is substituted.
5860 * Word is subjected to tilde expansion, parameter expansion,
5861 * command substitution, and arithmetic expansion.
5862 * If word is not needed, it is not expanded.
5864 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5865 * but also treat null var as if it is unset.
5867 int use_word = (!val || ((exp_save == ':') && !val[0]));
5869 use_word = !use_word;
5870 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5871 (exp_save == ':') ? "true" : "false", use_word);
5873 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5875 exp_word = to_be_freed;
5876 if (exp_op == '?') {
5877 /* mimic bash message */
5878 msg_and_die_if_script("%s: %s",
5882 : "parameter null or not set"
5883 /* ash has more specific messages, a-la: */
5884 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5886 //TODO: how interactive bash aborts expansion mid-command?
5891 if (exp_op == '=') {
5892 /* ${var=[word]} or ${var:=[word]} */
5893 if (isdigit(var[0]) || var[0] == '#') {
5894 /* mimic bash message */
5895 msg_and_die_if_script("$%s: cannot assign in this way", var);
5898 char *new_var = xasprintf("%s=%s", var, val);
5899 set_local_var(new_var, /*flag:*/ 0);
5903 } /* one of "-=+?" */
5905 *exp_saveptr = exp_save;
5911 *to_be_freed_pp = to_be_freed;
5915 /* Expand all variable references in given string, adding words to list[]
5916 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5917 * to be filled). This routine is extremely tricky: has to deal with
5918 * variables/parameters with whitespace, $* and $@, and constructs like
5919 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5920 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5922 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5923 * expansion of right-hand side of assignment == 1-element expand.
5925 char cant_be_null = 0; /* only bit 0x80 matters */
5926 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5929 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5930 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5931 debug_print_list("expand_vars_to_list", output, n);
5932 n = o_save_ptr(output, n);
5933 debug_print_list("expand_vars_to_list[0]", output, n);
5935 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5937 char *to_be_freed = NULL;
5938 const char *val = NULL;
5939 #if ENABLE_HUSH_TICK
5940 o_string subst_result = NULL_O_STRING;
5942 #if ENABLE_FEATURE_SH_MATH
5943 char arith_buf[sizeof(arith_t)*3 + 2];
5947 o_addchr(output, '\0');
5948 n = o_save_ptr(output, n);
5952 o_addblock(output, arg, p - arg);
5953 debug_print_list("expand_vars_to_list[1]", output, n);
5955 p = strchr(p, SPECIAL_VAR_SYMBOL);
5957 /* Fetch special var name (if it is indeed one of them)
5958 * and quote bit, force the bit on if singleword expansion -
5959 * important for not getting v=$@ expand to many words. */
5960 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5962 /* Is this variable quoted and thus expansion can't be null?
5963 * "$@" is special. Even if quoted, it can still
5964 * expand to nothing (not even an empty string),
5965 * thus it is excluded. */
5966 if ((first_ch & 0x7f) != '@')
5967 cant_be_null |= first_ch;
5969 switch (first_ch & 0x7f) {
5970 /* Highest bit in first_ch indicates that var is double-quoted */
5974 if (!G.global_argv[1])
5977 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5978 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5979 while (G.global_argv[i]) {
5980 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5981 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5982 if (G.global_argv[i++][0] && G.global_argv[i]) {
5983 /* this argv[] is not empty and not last:
5984 * put terminating NUL, start new word */
5985 o_addchr(output, '\0');
5986 debug_print_list("expand_vars_to_list[2]", output, n);
5987 n = o_save_ptr(output, n);
5988 debug_print_list("expand_vars_to_list[3]", output, n);
5992 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5993 * and in this case should treat it like '$*' - see 'else...' below */
5994 if (first_ch == ('@'|0x80) /* quoted $@ */
5995 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5998 o_addQstr(output, G.global_argv[i]);
5999 if (++i >= G.global_argc)
6001 o_addchr(output, '\0');
6002 debug_print_list("expand_vars_to_list[4]", output, n);
6003 n = o_save_ptr(output, n);
6005 } else { /* quoted $* (or v="$@" case): add as one word */
6007 o_addQstr(output, G.global_argv[i]);
6008 if (!G.global_argv[++i])
6011 o_addchr(output, G.ifs[0]);
6013 output->has_quoted_part = 1;
6017 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
6018 /* "Empty variable", used to make "" etc to not disappear */
6019 output->has_quoted_part = 1;
6021 cant_be_null = 0x80;
6023 #if ENABLE_HUSH_TICK
6024 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6025 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6027 /* Can't just stuff it into output o_string,
6028 * expanded result may need to be globbed
6030 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6031 G.last_exitcode = process_command_subs(&subst_result, arg);
6032 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6033 val = subst_result.data;
6036 #if ENABLE_FEATURE_SH_MATH
6037 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6040 arg++; /* skip '+' */
6041 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6042 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6043 res = expand_and_evaluate_arith(arg, NULL);
6044 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6045 sprintf(arith_buf, ARITH_FMT, res);
6051 val = expand_one_var(&to_be_freed, arg, &p);
6052 IF_HUSH_TICK(store_val:)
6053 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6054 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6055 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6056 if (val && val[0]) {
6057 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6060 } else { /* quoted $VAR, val will be appended below */
6061 output->has_quoted_part = 1;
6062 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6063 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6066 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6068 if (val && val[0]) {
6069 o_addQstr(output, val);
6073 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6074 * Do the check to avoid writing to a const string. */
6075 if (*p != SPECIAL_VAR_SYMBOL)
6076 *p = SPECIAL_VAR_SYMBOL;
6078 #if ENABLE_HUSH_TICK
6079 o_free(&subst_result);
6082 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6086 o_addchr(output, '\0');
6087 n = o_save_ptr(output, n);
6089 debug_print_list("expand_vars_to_list[a]", output, n);
6090 /* this part is literal, and it was already pre-quoted
6091 * if needed (much earlier), do not use o_addQstr here! */
6092 o_addstr_with_NUL(output, arg);
6093 debug_print_list("expand_vars_to_list[b]", output, n);
6094 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6095 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6098 /* allow to reuse list[n] later without re-growth */
6099 output->has_empty_slot = 1;
6101 o_addchr(output, '\0');
6107 static char **expand_variables(char **argv, unsigned expflags)
6111 o_string output = NULL_O_STRING;
6113 output.o_expflags = expflags;
6117 n = expand_vars_to_list(&output, n, *argv);
6120 debug_print_list("expand_variables", &output, n);
6122 /* output.data (malloced in one block) gets returned in "list" */
6123 list = o_finalize_list(&output, n);
6124 debug_print_strings("expand_variables[1]", list);
6128 static char **expand_strvec_to_strvec(char **argv)
6130 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6134 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6136 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6140 /* Used for expansion of right hand of assignments,
6141 * $((...)), heredocs, variable espansion parts.
6143 * NB: should NOT do globbing!
6144 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6146 static char *expand_string_to_string(const char *str, int do_unbackslash)
6148 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6149 const int do_unbackslash = 1;
6151 char *argv[2], **list;
6153 debug_printf_expand("string_to_string<='%s'\n", str);
6154 /* This is generally an optimization, but it also
6155 * handles "", which otherwise trips over !list[0] check below.
6156 * (is this ever happens that we actually get str="" here?)
6158 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6159 //TODO: Can use on strings with \ too, just unbackslash() them?
6160 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6161 return xstrdup(str);
6164 argv[0] = (char*)str;
6166 list = expand_variables(argv, do_unbackslash
6167 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6168 : EXP_FLAG_SINGLEWORD
6171 if (!list[0] || list[1])
6172 bb_error_msg_and_die("BUG in varexp2");
6173 /* actually, just move string 2*sizeof(char*) bytes back */
6174 overlapping_strcpy((char*)list, list[0]);
6176 unbackslash((char*)list);
6177 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6181 /* Used for "eval" builtin and case string */
6182 static char* expand_strvec_to_string(char **argv)
6186 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6187 /* Convert all NULs to spaces */
6192 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6193 bb_error_msg_and_die("BUG in varexp3");
6194 /* bash uses ' ' regardless of $IFS contents */
6199 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6200 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6204 static char **expand_assignments(char **argv, int count)
6209 G.expanded_assignments = p = NULL;
6210 /* Expand assignments into one string each */
6211 for (i = 0; i < count; i++) {
6212 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6214 G.expanded_assignments = NULL;
6219 static void switch_off_special_sigs(unsigned mask)
6222 while ((mask >>= 1) != 0) {
6226 #if ENABLE_HUSH_TRAP
6228 if (G_traps[sig] && !G_traps[sig][0])
6229 /* trap is '', has to remain SIG_IGN */
6232 G_traps[sig] = NULL;
6235 /* We are here only if no trap or trap was not '' */
6236 install_sighandler(sig, SIG_DFL);
6242 void re_execute_shell(char ***to_free, const char *s,
6243 char *g_argv0, char **g_argv,
6244 char **builtin_argv) NORETURN;
6246 static void reset_traps_to_defaults(void)
6248 /* This function is always called in a child shell
6249 * after fork (not vfork, NOMMU doesn't use this function).
6251 IF_HUSH_TRAP(unsigned sig;)
6254 /* Child shells are not interactive.
6255 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6256 * Testcase: (while :; do :; done) + ^Z should background.
6257 * Same goes for SIGTERM, SIGHUP, SIGINT.
6259 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6260 if (!G_traps && !mask)
6261 return; /* already no traps and no special sigs */
6263 /* Switch off special sigs */
6264 switch_off_special_sigs(mask);
6265 # if ENABLE_HUSH_JOB
6266 G_fatal_sig_mask = 0;
6268 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6269 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6270 * remain set in G.special_sig_mask */
6272 # if ENABLE_HUSH_TRAP
6276 /* Reset all sigs to default except ones with empty traps */
6277 for (sig = 0; sig < NSIG; sig++) {
6279 continue; /* no trap: nothing to do */
6280 if (!G_traps[sig][0])
6281 continue; /* empty trap: has to remain SIG_IGN */
6282 /* sig has non-empty trap, reset it: */
6284 G_traps[sig] = NULL;
6285 /* There is no signal for trap 0 (EXIT) */
6288 install_sighandler(sig, pick_sighandler(sig));
6295 static void re_execute_shell(char ***to_free, const char *s,
6296 char *g_argv0, char **g_argv,
6297 char **builtin_argv) NORETURN;
6298 static void re_execute_shell(char ***to_free, const char *s,
6299 char *g_argv0, char **g_argv,
6300 char **builtin_argv)
6302 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6303 /* delims + 2 * (number of bytes in printed hex numbers) */
6304 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6305 char *heredoc_argv[4];
6306 struct variable *cur;
6307 # if ENABLE_HUSH_FUNCTIONS
6308 struct function *funcp;
6312 unsigned long long empty_trap_mask;
6314 if (!g_argv0) { /* heredoc */
6315 argv = heredoc_argv;
6316 argv[0] = (char *) G.argv0_for_re_execing;
6317 argv[1] = (char *) "-<";
6318 argv[2] = (char *) s;
6320 pp = &argv[3]; /* used as pointer to empty environment */
6326 if (pp) while (*pp++)
6329 empty_trap_mask = 0;
6332 for (sig = 1; sig < NSIG; sig++) {
6333 if (G_traps[sig] && !G_traps[sig][0])
6334 empty_trap_mask |= 1LL << sig;
6338 sprintf(param_buf, NOMMU_HACK_FMT
6339 , (unsigned) G.root_pid
6340 , (unsigned) G.root_ppid
6341 , (unsigned) G.last_bg_pid
6342 , (unsigned) G.last_exitcode
6345 IF_HUSH_LOOPS(, G.depth_of_loop)
6347 # undef NOMMU_HACK_FMT
6348 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6349 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6352 for (cur = G.top_var; cur; cur = cur->next) {
6353 if (!cur->flg_export || cur->flg_read_only)
6356 # if ENABLE_HUSH_FUNCTIONS
6357 for (funcp = G.top_func; funcp; funcp = funcp->next)
6363 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6364 *pp++ = (char *) G.argv0_for_re_execing;
6366 for (cur = G.top_var; cur; cur = cur->next) {
6367 if (strcmp(cur->varstr, hush_version_str) == 0)
6369 if (cur->flg_read_only) {
6370 *pp++ = (char *) "-R";
6371 *pp++ = cur->varstr;
6372 } else if (!cur->flg_export) {
6373 *pp++ = (char *) "-V";
6374 *pp++ = cur->varstr;
6377 # if ENABLE_HUSH_FUNCTIONS
6378 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6379 *pp++ = (char *) "-F";
6380 *pp++ = funcp->name;
6381 *pp++ = funcp->body_as_string;
6384 /* We can pass activated traps here. Say, -Tnn:trap_string
6386 * However, POSIX says that subshells reset signals with traps
6388 * I tested bash-3.2 and it not only does that with true subshells
6389 * of the form ( list ), but with any forked children shells.
6390 * I set trap "echo W" WINCH; and then tried:
6392 * { echo 1; sleep 20; echo 2; } &
6393 * while true; do echo 1; sleep 20; echo 2; break; done &
6394 * true | { echo 1; sleep 20; echo 2; } | cat
6396 * In all these cases sending SIGWINCH to the child shell
6397 * did not run the trap. If I add trap "echo V" WINCH;
6398 * _inside_ group (just before echo 1), it works.
6400 * I conclude it means we don't need to pass active traps here.
6402 *pp++ = (char *) "-c";
6405 while (*++builtin_argv)
6406 *pp++ = *builtin_argv;
6407 *pp++ = (char *) "";
6412 /* *pp = NULL; - is already there */
6416 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6417 /* Don't propagate SIG_IGN to the child */
6418 if (SPECIAL_JOBSTOP_SIGS != 0)
6419 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6420 execve(bb_busybox_exec_path, argv, pp);
6421 /* Fallback. Useful for init=/bin/hush usage etc */
6422 if (argv[0][0] == '/')
6423 execve(argv[0], argv, pp);
6424 xfunc_error_retval = 127;
6425 bb_error_msg_and_die("can't re-execute the shell");
6427 #endif /* !BB_MMU */
6430 static int run_and_free_list(struct pipe *pi);
6432 /* Executing from string: eval, sh -c '...'
6433 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6434 * end_trigger controls how often we stop parsing
6435 * NUL: parse all, execute, return
6436 * ';': parse till ';' or newline, execute, repeat till EOF
6438 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6440 /* Why we need empty flag?
6441 * An obscure corner case "false; ``; echo $?":
6442 * empty command in `` should still set $? to 0.
6443 * But we can't just set $? to 0 at the start,
6444 * this breaks "false; echo `echo $?`" case.
6448 struct pipe *pipe_list;
6450 #if ENABLE_HUSH_INTERACTIVE
6451 if (end_trigger == ';')
6452 inp->promptmode = 0; /* PS1 */
6454 pipe_list = parse_stream(NULL, inp, end_trigger);
6455 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6456 /* If we are in "big" script
6457 * (not in `cmd` or something similar)...
6459 if (pipe_list == ERR_PTR && end_trigger == ';') {
6460 /* Discard cached input (rest of line) */
6461 int ch = inp->last_char;
6462 while (ch != EOF && ch != '\n') {
6463 //bb_error_msg("Discarded:'%c'", ch);
6468 /* This stream isn't empty */
6472 if (!pipe_list && empty)
6473 G.last_exitcode = 0;
6476 debug_print_tree(pipe_list, 0);
6477 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6478 run_and_free_list(pipe_list);
6480 if (G_flag_return_in_progress == 1)
6485 static void parse_and_run_string(const char *s)
6487 struct in_str input;
6488 setup_string_in_str(&input, s);
6489 parse_and_run_stream(&input, '\0');
6492 static void parse_and_run_file(FILE *f)
6494 struct in_str input;
6495 setup_file_in_str(&input, f);
6496 parse_and_run_stream(&input, ';');
6499 #if ENABLE_HUSH_TICK
6500 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6505 char **to_free = NULL;
6509 pid = BB_MMU ? xfork() : xvfork();
6510 if (pid == 0) { /* child */
6511 disable_restore_tty_pgrp_on_exit();
6512 /* Process substitution is not considered to be usual
6513 * 'command execution'.
6514 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6521 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6522 close(channel[0]); /* NB: close _first_, then move fd! */
6523 xmove_fd(channel[1], 1);
6524 /* Prevent it from trying to handle ctrl-z etc */
6525 IF_HUSH_JOB(G.run_list_level = 1;)
6526 # if ENABLE_HUSH_TRAP
6527 /* Awful hack for `trap` or $(trap).
6529 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6530 * contains an example where "trap" is executed in a subshell:
6532 * save_traps=$(trap)
6534 * eval "$save_traps"
6536 * Standard does not say that "trap" in subshell shall print
6537 * parent shell's traps. It only says that its output
6538 * must have suitable form, but then, in the above example
6539 * (which is not supposed to be normative), it implies that.
6541 * bash (and probably other shell) does implement it
6542 * (traps are reset to defaults, but "trap" still shows them),
6543 * but as a result, "trap" logic is hopelessly messed up:
6546 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6547 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6548 * # true | trap <--- trap is in subshell - no output (ditto)
6549 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6550 * trap -- 'echo Ho' SIGWINCH
6551 * # echo `(trap)` <--- in subshell in subshell - output
6552 * trap -- 'echo Ho' SIGWINCH
6553 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6554 * trap -- 'echo Ho' SIGWINCH
6556 * The rules when to forget and when to not forget traps
6557 * get really complex and nonsensical.
6559 * Our solution: ONLY bare $(trap) or `trap` is special.
6561 s = skip_whitespace(s);
6562 if (is_prefixed_with(s, "trap")
6563 && skip_whitespace(s + 4)[0] == '\0'
6565 static const char *const argv[] = { NULL, NULL };
6566 builtin_trap((char**)argv);
6567 fflush_all(); /* important */
6572 reset_traps_to_defaults();
6573 parse_and_run_string(s);
6574 _exit(G.last_exitcode);
6576 /* We re-execute after vfork on NOMMU. This makes this script safe:
6577 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6578 * huge=`cat BIG` # was blocking here forever
6581 re_execute_shell(&to_free,
6591 # if ENABLE_HUSH_FAST
6593 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6594 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6595 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6597 enable_restore_tty_pgrp_on_exit();
6602 return remember_FILE(xfdopen_for_read(channel[0]));
6605 /* Return code is exit status of the process that is run. */
6606 static int process_command_subs(o_string *dest, const char *s)
6609 struct in_str pipe_str;
6611 int status, ch, eol_cnt;
6613 fp = generate_stream_from_string(s, &pid);
6615 /* Now send results of command back into original context */
6616 setup_file_in_str(&pipe_str, fp);
6618 while ((ch = i_getch(&pipe_str)) != EOF) {
6624 o_addchr(dest, '\n');
6627 o_addQchr(dest, ch);
6630 debug_printf("done reading from `cmd` pipe, closing it\n");
6631 fclose_and_forget(fp);
6632 /* We need to extract exitcode. Test case
6633 * "true; echo `sleep 1; false` $?"
6635 safe_waitpid(pid, &status, 0);
6636 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6637 return WEXITSTATUS(status);
6639 #endif /* ENABLE_HUSH_TICK */
6642 static void setup_heredoc(struct redir_struct *redir)
6644 struct fd_pair pair;
6647 /* the _body_ of heredoc (misleading field name) */
6648 const char *heredoc = redir->rd_filename;
6655 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6656 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6660 len = strlen(heredoc);
6662 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6664 xmove_fd(pair.rd, redir->rd_fd);
6666 /* Try writing without forking. Newer kernels have
6667 * dynamically growing pipes. Must use non-blocking write! */
6670 written = write(pair.wr, heredoc, len);
6681 ndelay_off(pair.wr);
6683 /* Okay, pipe buffer was not big enough */
6684 /* Note: we must not create a stray child (bastard? :)
6685 * for the unsuspecting parent process. Child creates a grandchild
6686 * and exits before parent execs the process which consumes heredoc
6687 * (that exec happens after we return from this function) */
6694 disable_restore_tty_pgrp_on_exit();
6695 pid = BB_MMU ? xfork() : xvfork();
6699 close(redir->rd_fd); /* read side of the pipe */
6701 full_write(pair.wr, heredoc, len); /* may loop or block */
6704 /* Delegate blocking writes to another process */
6705 xmove_fd(pair.wr, STDOUT_FILENO);
6706 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6710 #if ENABLE_HUSH_FAST
6712 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6714 enable_restore_tty_pgrp_on_exit();
6720 wait(NULL); /* wait till child has died */
6726 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6727 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6730 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6732 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6733 sq[i].orig_fd = orig;
6734 sq[i].moved_to = moved;
6735 sq[i+1].orig_fd = -1; /* end marker */
6739 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6745 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6746 /* If we collide with an already moved fd... */
6747 if (fd == sq[i].moved_to) {
6748 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6749 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6750 if (sq[i].moved_to < 0) /* what? */
6754 if (fd == sq[i].orig_fd) {
6755 /* Example: echo Hello >/dev/null 1>&2 */
6756 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6761 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6762 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6763 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6764 if (moved_to < 0 && errno != EBADF)
6766 return append_squirrel(sq, i, fd, moved_to);
6769 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6774 if (sq) for (; sq[i].orig_fd >= 0; i++) {
6775 /* If we collide with an already moved fd... */
6776 if (fd == sq[i].orig_fd) {
6778 * "echo 3>FILE 3>&- 3>FILE"
6779 * "echo 3>&- 3>FILE"
6780 * No need for last redirect to insert
6781 * another "need to close 3" indicator.
6783 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6788 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6789 return append_squirrel(sq, i, fd, -1);
6792 /* fd: redirect wants this fd to be used (e.g. 3>file).
6793 * Move all conflicting internally used fds,
6794 * and remember them so that we can restore them later.
6796 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6798 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6801 #if ENABLE_HUSH_INTERACTIVE
6802 if (fd == G.interactive_fd) {
6803 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6804 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6805 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6806 return 1; /* "we closed fd" */
6809 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6810 * (1) Redirect in a forked child. No need to save FILEs' fds,
6811 * we aren't going to use them anymore, ok to trash.
6812 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6813 * but how are we doing to restore them?
6814 * "fileno(fd) = new_fd" can't be done.
6819 /* If this one of script's fds? */
6820 if (save_FILEs_on_redirect(fd, avoid_fd))
6821 return 1; /* yes. "we closed fd" */
6823 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6824 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6825 return 0; /* "we did not close fd" */
6828 static void restore_redirects(struct squirrel *sq)
6832 for (i = 0; sq[i].orig_fd >= 0; i++) {
6833 if (sq[i].moved_to >= 0) {
6834 /* We simply die on error */
6835 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6836 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6838 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6839 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6840 close(sq[i].orig_fd);
6846 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6848 restore_redirected_FILEs();
6851 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6852 static void close_saved_fds_and_FILE_fds(void)
6854 if (G_interactive_fd)
6855 close(G_interactive_fd);
6856 close_all_FILE_list();
6860 static int internally_opened_fd(int fd, struct squirrel *sq)
6864 #if ENABLE_HUSH_INTERACTIVE
6865 if (fd == G.interactive_fd)
6868 /* If this one of script's fds? */
6869 if (fd_in_FILEs(fd))
6872 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6873 if (fd == sq[i].moved_to)
6879 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6880 * and stderr if they are redirected. */
6881 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6883 struct redir_struct *redir;
6885 for (redir = prog->redirects; redir; redir = redir->next) {
6889 if (redir->rd_type == REDIRECT_HEREDOC2) {
6890 /* "rd_fd<<HERE" case */
6891 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6892 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6894 debug_printf_parse("set heredoc '%s'\n",
6895 redir->rd_filename);
6896 setup_heredoc(redir);
6900 if (redir->rd_dup == REDIRFD_TO_FILE) {
6901 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6905 if (redir->rd_filename == NULL) {
6908 * "cmd >" (no filename)
6909 * "cmd > <file" (2nd redirect starts too early)
6911 syntax_error("invalid redirect");
6914 mode = redir_table[redir->rd_type].mode;
6915 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6916 newfd = open_or_warn(p, mode);
6919 /* Error message from open_or_warn can be lost
6920 * if stderr has been redirected, but bash
6921 * and ash both lose it as well
6922 * (though zsh doesn't!)
6926 if (newfd == redir->rd_fd && sqp) {
6927 /* open() gave us precisely the fd we wanted.
6928 * This means that this fd was not busy
6929 * (not opened to anywhere).
6930 * Remember to close it on restore:
6932 *sqp = add_squirrel_closed(*sqp, newfd);
6933 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6936 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6937 newfd = redir->rd_dup;
6940 if (newfd == redir->rd_fd)
6943 /* if "N>FILE": move newfd to redir->rd_fd */
6944 /* if "N>&M": dup newfd to redir->rd_fd */
6945 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6947 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6948 if (newfd == REDIRFD_CLOSE) {
6949 /* "N>&-" means "close me" */
6951 /* ^^^ optimization: saving may already
6952 * have closed it. If not... */
6953 close(redir->rd_fd);
6955 /* Sometimes we do another close on restore, getting EBADF.
6956 * Consider "echo 3>FILE 3>&-"
6957 * first redirect remembers "need to close 3",
6958 * and second redirect closes 3! Restore code then closes 3 again.
6961 /* if newfd is a script fd or saved fd, simulate EBADF */
6962 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6964 //bb_perror_msg_and_die("can't duplicate file descriptor");
6965 newfd = -1; /* same effect as code above */
6967 xdup2(newfd, redir->rd_fd);
6968 if (redir->rd_dup == REDIRFD_TO_FILE)
6969 /* "rd_fd > FILE" */
6971 /* else: "rd_fd > rd_dup" */
6977 static char *find_in_path(const char *arg)
6980 const char *PATH = get_local_var_value("PATH");
6986 const char *end = strchrnul(PATH, ':');
6987 int sz = end - PATH; /* must be int! */
6991 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6993 /* We have xxx::yyyy in $PATH,
6994 * it means "use current dir" */
6997 if (access(ret, F_OK) == 0)
7010 static const struct built_in_command *find_builtin_helper(const char *name,
7011 const struct built_in_command *x,
7012 const struct built_in_command *end)
7015 if (strcmp(name, x->b_cmd) != 0) {
7019 debug_printf_exec("found builtin '%s'\n", name);
7024 static const struct built_in_command *find_builtin1(const char *name)
7026 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7028 static const struct built_in_command *find_builtin(const char *name)
7030 const struct built_in_command *x = find_builtin1(name);
7033 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7036 #if ENABLE_HUSH_FUNCTIONS
7037 static struct function **find_function_slot(const char *name)
7039 struct function **funcpp = &G.top_func;
7041 if (strcmp(name, (*funcpp)->name) == 0) {
7044 funcpp = &(*funcpp)->next;
7049 static const struct function *find_function(const char *name)
7051 const struct function *funcp = *find_function_slot(name);
7053 debug_printf_exec("found function '%s'\n", name);
7057 /* Note: takes ownership on name ptr */
7058 static struct function *new_function(char *name)
7060 struct function **funcpp = find_function_slot(name);
7061 struct function *funcp = *funcpp;
7063 if (funcp != NULL) {
7064 struct command *cmd = funcp->parent_cmd;
7065 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7067 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7069 /* Note: if !funcp->body, do not free body_as_string!
7070 * This is a special case of "-F name body" function:
7071 * body_as_string was not malloced! */
7073 free_pipe_list(funcp->body);
7075 free(funcp->body_as_string);
7079 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7080 cmd->argv[0] = funcp->name;
7081 cmd->group = funcp->body;
7083 cmd->group_as_string = funcp->body_as_string;
7087 debug_printf_exec("remembering new function '%s'\n", name);
7088 funcp = *funcpp = xzalloc(sizeof(*funcp));
7089 /*funcp->next = NULL;*/
7096 # if ENABLE_HUSH_UNSET
7097 static void unset_func(const char *name)
7099 struct function **funcpp = find_function_slot(name);
7100 struct function *funcp = *funcpp;
7102 if (funcp != NULL) {
7103 debug_printf_exec("freeing function '%s'\n", funcp->name);
7104 *funcpp = funcp->next;
7105 /* funcp is unlinked now, deleting it.
7106 * Note: if !funcp->body, the function was created by
7107 * "-F name body", do not free ->body_as_string
7108 * and ->name as they were not malloced. */
7110 free_pipe_list(funcp->body);
7113 free(funcp->body_as_string);
7122 #define exec_function(to_free, funcp, argv) \
7123 exec_function(funcp, argv)
7125 static void exec_function(char ***to_free,
7126 const struct function *funcp,
7127 char **argv) NORETURN;
7128 static void exec_function(char ***to_free,
7129 const struct function *funcp,
7135 argv[0] = G.global_argv[0];
7136 G.global_argv = argv;
7137 G.global_argc = n = 1 + string_array_len(argv + 1);
7139 // Example when we are here: "cmd | func"
7140 // func will run with saved-redirect fds open.
7141 // $ f() { echo /proc/self/fd/*; }
7143 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7144 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7147 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7148 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7149 // They are CLOEXEC so external programs won't see them, but
7150 // for "more correctness" we might want to close those extra fds here:
7151 //? close_saved_fds_and_FILE_fds();
7153 /* "we are in function, ok to use return" */
7154 G_flag_return_in_progress = -1;
7155 IF_HUSH_LOCAL(G.func_nest_level++;)
7157 /* On MMU, funcp->body is always non-NULL */
7158 n = run_list(funcp->body);
7162 //? close_saved_fds_and_FILE_fds();
7164 //TODO: check whether "true | func_with_return" works
7166 re_execute_shell(to_free,
7167 funcp->body_as_string,
7174 static int run_function(const struct function *funcp, char **argv)
7180 save_and_replace_G_args(&sv, argv);
7182 /* "we are in function, ok to use return" */
7183 sv_flg = G_flag_return_in_progress;
7184 G_flag_return_in_progress = -1;
7185 IF_HUSH_LOCAL(G.func_nest_level++;)
7187 /* On MMU, funcp->body is always non-NULL */
7190 /* Function defined by -F */
7191 parse_and_run_string(funcp->body_as_string);
7192 rc = G.last_exitcode;
7196 rc = run_list(funcp->body);
7199 # if ENABLE_HUSH_LOCAL
7201 struct variable *var;
7202 struct variable **var_pp;
7204 var_pp = &G.top_var;
7205 while ((var = *var_pp) != NULL) {
7206 if (var->func_nest_level < G.func_nest_level) {
7207 var_pp = &var->next;
7211 if (var->flg_export)
7212 bb_unsetenv(var->varstr);
7213 /* Remove from global list */
7214 *var_pp = var->next;
7220 G.func_nest_level--;
7223 G_flag_return_in_progress = sv_flg;
7225 restore_G_args(&sv, argv);
7229 #endif /* ENABLE_HUSH_FUNCTIONS */
7233 #define exec_builtin(to_free, x, argv) \
7234 exec_builtin(x, argv)
7236 #define exec_builtin(to_free, x, argv) \
7237 exec_builtin(to_free, argv)
7239 static void exec_builtin(char ***to_free,
7240 const struct built_in_command *x,
7241 char **argv) NORETURN;
7242 static void exec_builtin(char ***to_free,
7243 const struct built_in_command *x,
7249 //? close_saved_fds_and_FILE_fds();
7250 rcode = x->b_function(argv);
7255 /* On NOMMU, we must never block!
7256 * Example: { sleep 99 | read line; } & echo Ok
7258 re_execute_shell(to_free,
7267 static void execvp_or_die(char **argv) NORETURN;
7268 static void execvp_or_die(char **argv)
7271 debug_printf_exec("execing '%s'\n", argv[0]);
7272 /* Don't propagate SIG_IGN to the child */
7273 if (SPECIAL_JOBSTOP_SIGS != 0)
7274 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7275 execvp(argv[0], argv);
7277 if (errno == EACCES) e = 126;
7278 if (errno == ENOENT) e = 127;
7279 bb_perror_msg("can't execute '%s'", argv[0]);
7283 #if ENABLE_HUSH_MODE_X
7284 static void dump_cmd_in_x_mode(char **argv)
7286 if (G_x_mode && argv) {
7287 /* We want to output the line in one write op */
7295 len += strlen(argv[n++]) + 1;
7301 p += sprintf(p, " %s", argv[n++]);
7309 # define dump_cmd_in_x_mode(argv) ((void)0)
7313 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7314 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7315 #define pseudo_exec(nommu_save, command, argv_expanded) \
7316 pseudo_exec(command, argv_expanded)
7319 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7321 * Don't exit() here. If you don't exec, use _exit instead.
7322 * The at_exit handlers apparently confuse the calling process,
7323 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7325 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7326 char **argv, int assignment_cnt,
7327 char **argv_expanded) NORETURN;
7328 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7329 char **argv, int assignment_cnt,
7330 char **argv_expanded)
7334 new_env = expand_assignments(argv, assignment_cnt);
7335 dump_cmd_in_x_mode(new_env);
7337 if (!argv[assignment_cnt]) {
7338 /* Case when we are here: ... | var=val | ...
7339 * (note that we do not exit early, i.e., do not optimize out
7340 * expand_assignments(): think about ... | var=`sleep 1` | ...
7342 free_strings(new_env);
7343 _exit(EXIT_SUCCESS);
7347 set_vars_and_save_old(new_env);
7348 free(new_env); /* optional */
7349 /* we can also destroy set_vars_and_save_old's return value,
7352 nommu_save->new_env = new_env;
7353 nommu_save->old_vars = set_vars_and_save_old(new_env);
7356 if (argv_expanded) {
7357 argv = argv_expanded;
7359 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7361 nommu_save->argv = argv;
7364 dump_cmd_in_x_mode(argv);
7366 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7367 if (strchr(argv[0], '/') != NULL)
7371 #if ENABLE_HUSH_FUNCTIONS
7372 /* Check if the command matches any functions (this goes before bltins) */
7374 const struct function *funcp = find_function(argv[0]);
7376 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7381 /* Check if the command matches any of the builtins.
7382 * Depending on context, this might be redundant. But it's
7383 * easier to waste a few CPU cycles than it is to figure out
7384 * if this is one of those cases.
7387 /* On NOMMU, it is more expensive to re-execute shell
7388 * just in order to run echo or test builtin.
7389 * It's better to skip it here and run corresponding
7390 * non-builtin later. */
7391 const struct built_in_command *x;
7392 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7394 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7398 #if ENABLE_FEATURE_SH_STANDALONE
7399 /* Check if the command matches any busybox applets */
7401 int a = find_applet_by_name(argv[0]);
7403 # if BB_MMU /* see above why on NOMMU it is not allowed */
7404 if (APPLET_IS_NOEXEC(a)) {
7405 /* Do not leak open fds from opened script files etc.
7406 * Testcase: interactive "ls -l /proc/self/fd"
7407 * should not show tty fd open.
7409 close_saved_fds_and_FILE_fds();
7410 //FIXME: should also close saved redir fds
7411 /* Without this, "rm -i FILE" can't be ^C'ed: */
7412 switch_off_special_sigs(G.special_sig_mask);
7413 debug_printf_exec("running applet '%s'\n", argv[0]);
7414 run_noexec_applet_and_exit(a, argv[0], argv);
7417 /* Re-exec ourselves */
7418 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7419 /* Don't propagate SIG_IGN to the child */
7420 if (SPECIAL_JOBSTOP_SIGS != 0)
7421 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7422 execv(bb_busybox_exec_path, argv);
7423 /* If they called chroot or otherwise made the binary no longer
7424 * executable, fall through */
7429 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7432 execvp_or_die(argv);
7435 /* Called after [v]fork() in run_pipe
7437 static void pseudo_exec(nommu_save_t *nommu_save,
7438 struct command *command,
7439 char **argv_expanded) NORETURN;
7440 static void pseudo_exec(nommu_save_t *nommu_save,
7441 struct command *command,
7442 char **argv_expanded)
7444 if (command->argv) {
7445 pseudo_exec_argv(nommu_save, command->argv,
7446 command->assignment_cnt, argv_expanded);
7449 if (command->group) {
7450 /* Cases when we are here:
7453 * ... | ( list ) | ...
7454 * ... | { list } | ...
7458 debug_printf_exec("pseudo_exec: run_list\n");
7459 reset_traps_to_defaults();
7460 rcode = run_list(command->group);
7461 /* OK to leak memory by not calling free_pipe_list,
7462 * since this process is about to exit */
7465 re_execute_shell(&nommu_save->argv_from_re_execing,
7466 command->group_as_string,
7473 /* Case when we are here: ... | >file */
7474 debug_printf_exec("pseudo_exec'ed null command\n");
7475 _exit(EXIT_SUCCESS);
7479 static const char *get_cmdtext(struct pipe *pi)
7485 /* This is subtle. ->cmdtext is created only on first backgrounding.
7486 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7487 * On subsequent bg argv is trashed, but we won't use it */
7491 argv = pi->cmds[0].argv;
7493 pi->cmdtext = xzalloc(1);
7498 len += strlen(*argv) + 1;
7502 argv = pi->cmds[0].argv;
7504 p = stpcpy(p, *argv);
7511 static void remove_job_from_table(struct pipe *pi)
7513 struct pipe *prev_pipe;
7515 if (pi == G.job_list) {
7516 G.job_list = pi->next;
7518 prev_pipe = G.job_list;
7519 while (prev_pipe->next != pi)
7520 prev_pipe = prev_pipe->next;
7521 prev_pipe->next = pi->next;
7525 G.last_jobid = G.job_list->jobid;
7528 static void delete_finished_job(struct pipe *pi)
7530 remove_job_from_table(pi);
7534 static void clean_up_last_dead_job(void)
7536 if (G.job_list && !G.job_list->alive_cmds)
7537 delete_finished_job(G.job_list);
7540 static void insert_job_into_table(struct pipe *pi)
7542 struct pipe *job, **jobp;
7545 clean_up_last_dead_job();
7547 /* Find the end of the list, and find next job ID to use */
7550 while ((job = *jobp) != NULL) {
7557 /* Create a new job struct at the end */
7558 job = *jobp = xmemdup(pi, sizeof(*pi));
7560 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7561 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7562 for (i = 0; i < pi->num_cmds; i++) {
7563 job->cmds[i].pid = pi->cmds[i].pid;
7564 /* all other fields are not used and stay zero */
7566 job->cmdtext = xstrdup(get_cmdtext(pi));
7568 if (G_interactive_fd)
7569 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7570 G.last_jobid = job->jobid;
7574 static int job_exited_or_stopped(struct pipe *pi)
7578 if (pi->alive_cmds != pi->stopped_cmds)
7581 /* All processes in fg pipe have exited or stopped */
7585 rcode = pi->cmds[i].cmd_exitcode;
7586 /* usually last process gives overall exitstatus,
7587 * but with "set -o pipefail", last *failed* process does */
7588 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7591 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7595 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7602 dead = WIFEXITED(status) || WIFSIGNALED(status);
7605 if (WIFSTOPPED(status))
7606 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7607 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7608 if (WIFSIGNALED(status))
7609 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7610 childpid, WTERMSIG(status), WEXITSTATUS(status));
7611 if (WIFEXITED(status))
7612 debug_printf_jobs("pid %d exited, exitcode %d\n",
7613 childpid, WEXITSTATUS(status));
7615 /* Were we asked to wait for a fg pipe? */
7617 i = fg_pipe->num_cmds;
7622 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7623 if (fg_pipe->cmds[i].pid != childpid)
7627 fg_pipe->cmds[i].pid = 0;
7628 fg_pipe->alive_cmds--;
7629 ex = WEXITSTATUS(status);
7630 /* bash prints killer signal's name for *last*
7631 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7632 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7634 if (WIFSIGNALED(status)) {
7635 int sig = WTERMSIG(status);
7636 if (i == fg_pipe->num_cmds-1)
7637 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7638 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7639 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7640 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7641 * Maybe we need to use sig | 128? */
7644 fg_pipe->cmds[i].cmd_exitcode = ex;
7646 fg_pipe->stopped_cmds++;
7648 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7649 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7650 rcode = job_exited_or_stopped(fg_pipe);
7652 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7653 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7654 * and "killall -STOP cat" */
7655 if (G_interactive_fd) {
7657 if (fg_pipe->alive_cmds != 0)
7658 insert_job_into_table(fg_pipe);
7662 if (fg_pipe->alive_cmds == 0)
7665 /* There are still running processes in the fg_pipe */
7668 /* It wasn't in fg_pipe, look for process in bg pipes */
7672 /* We were asked to wait for bg or orphaned children */
7673 /* No need to remember exitcode in this case */
7674 for (pi = G.job_list; pi; pi = pi->next) {
7675 for (i = 0; i < pi->num_cmds; i++) {
7676 if (pi->cmds[i].pid == childpid)
7677 goto found_pi_and_prognum;
7680 /* Happens when shell is used as init process (init=/bin/sh) */
7681 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7682 return -1; /* this wasn't a process from fg_pipe */
7684 found_pi_and_prognum:
7687 int rcode = WEXITSTATUS(status);
7688 if (WIFSIGNALED(status))
7689 rcode = 128 + WTERMSIG(status);
7690 pi->cmds[i].cmd_exitcode = rcode;
7691 if (G.last_bg_pid == pi->cmds[i].pid)
7692 G.last_bg_pid_exitcode = rcode;
7693 pi->cmds[i].pid = 0;
7695 if (!pi->alive_cmds) {
7696 if (G_interactive_fd) {
7697 printf(JOB_STATUS_FORMAT, pi->jobid,
7698 "Done", pi->cmdtext);
7699 delete_finished_job(pi);
7702 * bash deletes finished jobs from job table only in interactive mode,
7703 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7704 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7705 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7706 * We only retain one "dead" job, if it's the single job on the list.
7707 * This covers most of real-world scenarios where this is useful.
7709 if (pi != G.job_list)
7710 delete_finished_job(pi);
7718 return -1; /* this wasn't a process from fg_pipe */
7721 /* Check to see if any processes have exited -- if they have,
7722 * figure out why and see if a job has completed.
7724 * If non-NULL fg_pipe: wait for its completion or stop.
7725 * Return its exitcode or zero if stopped.
7727 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7728 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7729 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7730 * or 0 if no children changed status.
7732 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7733 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7734 * or 0 if no children changed status.
7736 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7742 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7744 attributes = WUNTRACED;
7745 if (fg_pipe == NULL)
7746 attributes |= WNOHANG;
7749 #if ENABLE_HUSH_FAST
7750 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7751 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7752 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7753 /* There was neither fork nor SIGCHLD since last waitpid */
7754 /* Avoid doing waitpid syscall if possible */
7755 if (!G.we_have_children) {
7759 if (fg_pipe == NULL) { /* is WNOHANG set? */
7760 /* We have children, but they did not exit
7761 * or stop yet (we saw no SIGCHLD) */
7764 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7768 /* Do we do this right?
7769 * bash-3.00# sleep 20 | false
7771 * [3]+ Stopped sleep 20 | false
7772 * bash-3.00# echo $?
7773 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7774 * [hush 1.14.0: yes we do it right]
7778 #if ENABLE_HUSH_FAST
7780 i = G.count_SIGCHLD;
7782 childpid = waitpid(-1, &status, attributes);
7783 if (childpid <= 0) {
7784 if (childpid && errno != ECHILD)
7785 bb_perror_msg("waitpid");
7786 #if ENABLE_HUSH_FAST
7787 else { /* Until next SIGCHLD, waitpid's are useless */
7788 G.we_have_children = (childpid == 0);
7789 G.handled_SIGCHLD = i;
7790 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7793 /* ECHILD (no children), or 0 (no change in children status) */
7797 rcode = process_wait_result(fg_pipe, childpid, status);
7799 /* fg_pipe exited or stopped */
7802 if (childpid == waitfor_pid) {
7803 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7804 rcode = WEXITSTATUS(status);
7805 if (WIFSIGNALED(status))
7806 rcode = 128 + WTERMSIG(status);
7807 if (WIFSTOPPED(status))
7808 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7809 rcode = 128 + WSTOPSIG(status);
7811 break; /* "wait PID" called us, give it exitcode+1 */
7813 /* This wasn't one of our processes, or */
7814 /* fg_pipe still has running processes, do waitpid again */
7815 } /* while (waitpid succeeds)... */
7821 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7824 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7825 if (G_saved_tty_pgrp) {
7826 /* Job finished, move the shell to the foreground */
7827 p = getpgrp(); /* our process group id */
7828 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7829 tcsetpgrp(G_interactive_fd, p);
7835 /* Start all the jobs, but don't wait for anything to finish.
7838 * Return code is normally -1, when the caller has to wait for children
7839 * to finish to determine the exit status of the pipe. If the pipe
7840 * is a simple builtin command, however, the action is done by the
7841 * time run_pipe returns, and the exit code is provided as the
7844 * Returns -1 only if started some children. IOW: we have to
7845 * mask out retvals of builtins etc with 0xff!
7847 * The only case when we do not need to [v]fork is when the pipe
7848 * is single, non-backgrounded, non-subshell command. Examples:
7849 * cmd ; ... { list } ; ...
7850 * cmd && ... { list } && ...
7851 * cmd || ... { list } || ...
7852 * If it is, then we can run cmd as a builtin, NOFORK,
7853 * or (if SH_STANDALONE) an applet, and we can run the { list }
7854 * with run_list. If it isn't one of these, we fork and exec cmd.
7856 * Cases when we must fork:
7857 * non-single: cmd | cmd
7858 * backgrounded: cmd & { list } &
7859 * subshell: ( list ) [&]
7861 #if !ENABLE_HUSH_MODE_X
7862 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7863 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7865 static int redirect_and_varexp_helper(char ***new_env_p,
7866 struct variable **old_vars_p,
7867 struct command *command,
7868 struct squirrel **sqp,
7869 char **argv_expanded)
7871 /* setup_redirects acts on file descriptors, not FILEs.
7872 * This is perfect for work that comes after exec().
7873 * Is it really safe for inline use? Experimentally,
7874 * things seem to work. */
7875 int rcode = setup_redirects(command, sqp);
7877 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7878 *new_env_p = new_env;
7879 dump_cmd_in_x_mode(new_env);
7880 dump_cmd_in_x_mode(argv_expanded);
7882 *old_vars_p = set_vars_and_save_old(new_env);
7886 static NOINLINE int run_pipe(struct pipe *pi)
7888 static const char *const null_ptr = NULL;
7892 struct command *command;
7893 char **argv_expanded;
7895 struct squirrel *squirrel = NULL;
7898 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7901 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7902 * Result should be 3 lines: q w e, qwe, q w e
7904 G.ifs = get_local_var_value("IFS");
7908 IF_HUSH_JOB(pi->pgrp = -1;)
7909 pi->stopped_cmds = 0;
7910 command = &pi->cmds[0];
7911 argv_expanded = NULL;
7913 if (pi->num_cmds != 1
7914 || pi->followup == PIPE_BG
7915 || command->cmd_type == CMD_SUBSHELL
7922 debug_printf_exec(": group:%p argv:'%s'\n",
7923 command->group, command->argv ? command->argv[0] : "NONE");
7925 if (command->group) {
7926 #if ENABLE_HUSH_FUNCTIONS
7927 if (command->cmd_type == CMD_FUNCDEF) {
7928 /* "executing" func () { list } */
7929 struct function *funcp;
7931 funcp = new_function(command->argv[0]);
7932 /* funcp->name is already set to argv[0] */
7933 funcp->body = command->group;
7935 funcp->body_as_string = command->group_as_string;
7936 command->group_as_string = NULL;
7938 command->group = NULL;
7939 command->argv[0] = NULL;
7940 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7941 funcp->parent_cmd = command;
7942 command->child_func = funcp;
7944 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7946 return EXIT_SUCCESS;
7950 debug_printf("non-subshell group\n");
7951 rcode = 1; /* exitcode if redir failed */
7952 if (setup_redirects(command, &squirrel) == 0) {
7953 debug_printf_exec(": run_list\n");
7954 rcode = run_list(command->group) & 0xff;
7956 restore_redirects(squirrel);
7957 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7959 debug_printf_exec("run_pipe: return %d\n", rcode);
7963 argv = command->argv ? command->argv : (char **) &null_ptr;
7965 const struct built_in_command *x;
7966 #if ENABLE_HUSH_FUNCTIONS
7967 const struct function *funcp;
7971 char **new_env = NULL;
7972 struct variable *old_vars = NULL;
7974 if (argv[command->assignment_cnt] == NULL) {
7975 /* Assignments, but no command */
7976 /* Ensure redirects take effect (that is, create files).
7977 * Try "a=t >file" */
7978 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7979 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7980 /* Set shell variables */
7984 if (set_local_var(*argv, /*flag:*/ 0)) {
7985 /* assignment to readonly var / putenv error? */
7991 /* Redirect error sets $? to 1. Otherwise,
7992 * if evaluating assignment value set $?, retain it.
7993 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7995 rcode = G.last_exitcode;
7996 /* Exit, _skipping_ variable restoring code: */
7997 goto clean_up_and_ret0;
7999 #else /* Older, bigger, but more correct code */
8001 rcode = setup_redirects(command, &squirrel);
8002 restore_redirects(squirrel);
8003 /* Set shell variables */
8005 bb_putchar_stderr('+');
8007 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8009 fprintf(stderr, " %s", p);
8010 debug_printf_exec("set shell var:'%s'->'%s'\n",
8012 if (set_local_var(p, /*flag:*/ 0)) {
8013 /* assignment to readonly var / putenv error? */
8019 bb_putchar_stderr('\n');
8020 /* Redirect error sets $? to 1. Otherwise,
8021 * if evaluating assignment value set $?, retain it.
8022 * Try "false; q=`exit 2`; echo $?" - should print 2: */
8024 rcode = G.last_exitcode;
8025 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8027 debug_printf_exec("run_pipe: return %d\n", rcode);
8032 /* Expand the rest into (possibly) many strings each */
8034 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8035 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8039 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8042 /* if someone gives us an empty string: `cmd with empty output` */
8043 if (!argv_expanded[0]) {
8044 free(argv_expanded);
8046 return G.last_exitcode;
8049 #if ENABLE_HUSH_FUNCTIONS
8050 /* Check if argv[0] matches any functions (this goes before bltins) */
8051 funcp = find_function(argv_expanded[0]);
8055 x = find_builtin(argv_expanded[0]);
8058 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8059 debug_printf("exec with redirects only\n");
8060 rcode = setup_redirects(command, NULL);
8061 /* rcode=1 can be if redir file can't be opened */
8062 goto clean_up_and_ret1;
8065 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8068 debug_printf_exec(": builtin '%s' '%s'...\n",
8069 x->b_cmd, argv_expanded[1]);
8071 rcode = x->b_function(argv_expanded) & 0xff;
8074 #if ENABLE_HUSH_FUNCTIONS
8076 # if ENABLE_HUSH_LOCAL
8077 struct variable **sv;
8078 sv = G.shadowed_vars_pp;
8079 G.shadowed_vars_pp = &old_vars;
8081 debug_printf_exec(": function '%s' '%s'...\n",
8082 funcp->name, argv_expanded[1]);
8083 rcode = run_function(funcp, argv_expanded) & 0xff;
8084 # if ENABLE_HUSH_LOCAL
8085 G.shadowed_vars_pp = sv;
8091 unset_vars(new_env);
8093 /* clean_up_and_ret0: */
8094 restore_redirects(squirrel);
8096 * Try "usleep 99999999" + ^C + "echo $?"
8097 * with FEATURE_SH_NOFORK=y.
8100 /* It was builtin or nofork.
8101 * if this would be a real fork/execed program,
8102 * it should have died if a fatal sig was received.
8103 * But OTOH, there was no separate process,
8104 * the sig was sent to _shell_, not to non-existing
8106 * Let's just handle ^C only, this one is obvious:
8107 * we aren't ok with exitcode 0 when ^C was pressed
8108 * during builtin/nofork.
8110 if (sigismember(&G.pending_set, SIGINT))
8111 rcode = 128 + SIGINT;
8114 free(argv_expanded);
8115 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8117 debug_printf_exec("run_pipe return %d\n", rcode);
8121 if (ENABLE_FEATURE_SH_NOFORK) {
8122 int n = find_applet_by_name(argv_expanded[0]);
8123 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8124 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8126 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8127 argv_expanded[0], argv_expanded[1]);
8129 * Note: signals (^C) can't interrupt here.
8130 * We remember them and they will be acted upon
8131 * after applet returns.
8132 * This makes applets which can run for a long time
8133 * and/or wait for user input ineligible for NOFORK:
8134 * for example, "yes" or "rm" (rm -i waits for input).
8136 rcode = run_nofork_applet(n, argv_expanded);
8138 goto clean_up_and_ret;
8141 /* It is neither builtin nor applet. We must fork. */
8145 /* NB: argv_expanded may already be created, and that
8146 * might include `cmd` runs! Do not rerun it! We *must*
8147 * use argv_expanded if it's non-NULL */
8149 /* Going to fork a child per each pipe member */
8154 while (cmd_no < pi->num_cmds) {
8155 struct fd_pair pipefds;
8157 volatile nommu_save_t nommu_save;
8158 nommu_save.new_env = NULL;
8159 nommu_save.old_vars = NULL;
8160 nommu_save.argv = NULL;
8161 nommu_save.argv_from_re_execing = NULL;
8163 command = &pi->cmds[cmd_no];
8165 if (command->argv) {
8166 debug_printf_exec(": pipe member '%s' '%s'...\n",
8167 command->argv[0], command->argv[1]);
8169 debug_printf_exec(": pipe member with no argv\n");
8172 /* pipes are inserted between pairs of commands */
8175 if (cmd_no < pi->num_cmds)
8176 xpiped_pair(pipefds);
8178 command->pid = BB_MMU ? fork() : vfork();
8179 if (!command->pid) { /* child */
8181 disable_restore_tty_pgrp_on_exit();
8182 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8184 /* Every child adds itself to new process group
8185 * with pgid == pid_of_first_child_in_pipe */
8186 if (G.run_list_level == 1 && G_interactive_fd) {
8189 if (pgrp < 0) /* true for 1st process only */
8191 if (setpgid(0, pgrp) == 0
8192 && pi->followup != PIPE_BG
8193 && G_saved_tty_pgrp /* we have ctty */
8195 /* We do it in *every* child, not just first,
8197 tcsetpgrp(G_interactive_fd, pgrp);
8201 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8202 /* 1st cmd in backgrounded pipe
8203 * should have its stdin /dev/null'ed */
8205 if (open(bb_dev_null, O_RDONLY))
8206 xopen("/", O_RDONLY);
8208 xmove_fd(next_infd, 0);
8210 xmove_fd(pipefds.wr, 1);
8213 /* Like bash, explicit redirects override pipes,
8214 * and the pipe fd (fd#1) is available for dup'ing:
8215 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8216 * of cmd1 goes into pipe.
8218 if (setup_redirects(command, NULL)) {
8219 /* Happens when redir file can't be opened:
8220 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8222 * hush: can't open '/qwe/rty': No such file or directory
8224 * (echo BAR is not executed, it hits _exit(1) below)
8229 /* Stores to nommu_save list of env vars putenv'ed
8230 * (NOMMU, on MMU we don't need that) */
8231 /* cast away volatility... */
8232 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8233 /* pseudo_exec() does not return */
8236 /* parent or error */
8237 #if ENABLE_HUSH_FAST
8239 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8241 enable_restore_tty_pgrp_on_exit();
8243 /* Clean up after vforked child */
8244 free(nommu_save.argv);
8245 free(nommu_save.argv_from_re_execing);
8246 unset_vars(nommu_save.new_env);
8247 add_vars(nommu_save.old_vars);
8249 free(argv_expanded);
8250 argv_expanded = NULL;
8251 if (command->pid < 0) { /* [v]fork failed */
8252 /* Clearly indicate, was it fork or vfork */
8253 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8257 /* Second and next children need to know pid of first one */
8259 pi->pgrp = command->pid;
8265 if (cmd_no < pi->num_cmds)
8267 /* Pass read (output) pipe end to next iteration */
8268 next_infd = pipefds.rd;
8271 if (!pi->alive_cmds) {
8273 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8278 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8282 /* NB: called by pseudo_exec, and therefore must not modify any
8283 * global data until exec/_exit (we can be a child after vfork!) */
8284 static int run_list(struct pipe *pi)
8286 #if ENABLE_HUSH_CASE
8287 char *case_word = NULL;
8289 #if ENABLE_HUSH_LOOPS
8290 struct pipe *loop_top = NULL;
8291 char **for_lcur = NULL;
8292 char **for_list = NULL;
8294 smallint last_followup;
8296 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8297 smalluint cond_code = 0;
8299 enum { cond_code = 0 };
8302 smallint rword; /* RES_foo */
8303 smallint last_rword; /* ditto */
8306 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8309 #if ENABLE_HUSH_LOOPS
8310 /* Check syntax for "for" */
8313 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8314 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8316 /* current word is FOR or IN (BOLD in comments below) */
8317 if (cpipe->next == NULL) {
8318 syntax_error("malformed for");
8320 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8323 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8324 if (cpipe->next->res_word == RES_DO)
8326 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8327 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8328 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8330 syntax_error("malformed for");
8332 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8339 /* Past this point, all code paths should jump to ret: label
8340 * in order to return, no direct "return" statements please.
8341 * This helps to ensure that no memory is leaked. */
8349 last_rword = RES_XXXX;
8351 last_followup = PIPE_SEQ;
8352 rcode = G.last_exitcode;
8354 /* Go through list of pipes, (maybe) executing them. */
8355 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8357 int sv_errexit_depth;
8361 if (G_flag_return_in_progress == 1)
8364 IF_HAS_KEYWORDS(rword = pi->res_word;)
8365 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8366 rword, cond_code, last_rword);
8368 sv_errexit_depth = G.errexit_depth;
8369 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8370 pi->followup != PIPE_SEQ
8374 #if ENABLE_HUSH_LOOPS
8375 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8376 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8378 /* start of a loop: remember where loop starts */
8383 /* Still in the same "if...", "then..." or "do..." branch? */
8384 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8385 if ((rcode == 0 && last_followup == PIPE_OR)
8386 || (rcode != 0 && last_followup == PIPE_AND)
8388 /* It is "<true> || CMD" or "<false> && CMD"
8389 * and we should not execute CMD */
8390 debug_printf_exec("skipped cmd because of || or &&\n");
8391 last_followup = pi->followup;
8392 goto dont_check_jobs_but_continue;
8395 last_followup = pi->followup;
8396 IF_HAS_KEYWORDS(last_rword = rword;)
8399 if (rword == RES_THEN) {
8400 /* if false; then ... fi has exitcode 0! */
8401 G.last_exitcode = rcode = EXIT_SUCCESS;
8402 /* "if <false> THEN cmd": skip cmd */
8406 if (rword == RES_ELSE || rword == RES_ELIF) {
8407 /* "if <true> then ... ELSE/ELIF cmd":
8408 * skip cmd and all following ones */
8413 #if ENABLE_HUSH_LOOPS
8414 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8416 /* first loop through for */
8418 static const char encoded_dollar_at[] ALIGN1 = {
8419 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8420 }; /* encoded representation of "$@" */
8421 static const char *const encoded_dollar_at_argv[] = {
8422 encoded_dollar_at, NULL
8423 }; /* argv list with one element: "$@" */
8426 vals = (char**)encoded_dollar_at_argv;
8427 if (pi->next->res_word == RES_IN) {
8428 /* if no variable values after "in" we skip "for" */
8429 if (!pi->next->cmds[0].argv) {
8430 G.last_exitcode = rcode = EXIT_SUCCESS;
8431 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8434 vals = pi->next->cmds[0].argv;
8435 } /* else: "for var; do..." -> assume "$@" list */
8436 /* create list of variable values */
8437 debug_print_strings("for_list made from", vals);
8438 for_list = expand_strvec_to_strvec(vals);
8439 for_lcur = for_list;
8440 debug_print_strings("for_list", for_list);
8443 /* "for" loop is over, clean up */
8449 /* Insert next value from for_lcur */
8450 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8451 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8454 if (rword == RES_IN) {
8455 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8457 if (rword == RES_DONE) {
8458 continue; /* "done" has no cmds too */
8461 #if ENABLE_HUSH_CASE
8462 if (rword == RES_CASE) {
8463 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8464 case_word = expand_strvec_to_string(pi->cmds->argv);
8465 unbackslash(case_word);
8468 if (rword == RES_MATCH) {
8471 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8472 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8474 /* all prev words didn't match, does this one match? */
8475 argv = pi->cmds->argv;
8477 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8478 /* TODO: which FNM_xxx flags to use? */
8479 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8480 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8482 if (cond_code == 0) { /* match! we will execute this branch */
8484 case_word = NULL; /* make future "word)" stop */
8491 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8492 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8494 continue; /* not matched yet, skip this pipe */
8496 if (rword == RES_ESAC) {
8497 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8499 /* "case" did not match anything: still set $? (to 0) */
8500 G.last_exitcode = rcode = EXIT_SUCCESS;
8504 /* Just pressing <enter> in shell should check for jobs.
8505 * OTOH, in non-interactive shell this is useless
8506 * and only leads to extra job checks */
8507 if (pi->num_cmds == 0) {
8508 if (G_interactive_fd)
8509 goto check_jobs_and_continue;
8513 /* After analyzing all keywords and conditions, we decided
8514 * to execute this pipe. NB: have to do checkjobs(NULL)
8515 * after run_pipe to collect any background children,
8516 * even if list execution is to be stopped. */
8517 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8518 #if ENABLE_HUSH_LOOPS
8519 G.flag_break_continue = 0;
8521 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8523 /* We ran a builtin, function, or group.
8524 * rcode is already known
8525 * and we don't need to wait for anything. */
8526 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8527 G.last_exitcode = rcode;
8528 check_and_run_traps();
8529 #if ENABLE_HUSH_LOOPS
8530 /* Was it "break" or "continue"? */
8531 if (G.flag_break_continue) {
8532 smallint fbc = G.flag_break_continue;
8533 /* We might fall into outer *loop*,
8534 * don't want to break it too */
8536 G.depth_break_continue--;
8537 if (G.depth_break_continue == 0)
8538 G.flag_break_continue = 0;
8539 /* else: e.g. "continue 2" should *break* once, *then* continue */
8540 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8541 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8542 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8545 /* "continue": simulate end of loop */
8550 if (G_flag_return_in_progress == 1) {
8551 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8554 } else if (pi->followup == PIPE_BG) {
8555 /* What does bash do with attempts to background builtins? */
8556 /* even bash 3.2 doesn't do that well with nested bg:
8557 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8558 * I'm NOT treating inner &'s as jobs */
8560 if (G.run_list_level == 1)
8561 insert_job_into_table(pi);
8563 /* Last command's pid goes to $! */
8564 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8565 G.last_bg_pid_exitcode = 0;
8566 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8567 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8568 rcode = EXIT_SUCCESS;
8572 if (G.run_list_level == 1 && G_interactive_fd) {
8573 /* Waits for completion, then fg's main shell */
8574 rcode = checkjobs_and_fg_shell(pi);
8575 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8579 /* This one just waits for completion */
8580 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8581 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8583 G.last_exitcode = rcode;
8584 check_and_run_traps();
8587 /* Handle "set -e" */
8588 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8589 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8590 if (G.errexit_depth == 0)
8593 G.errexit_depth = sv_errexit_depth;
8595 /* Analyze how result affects subsequent commands */
8597 if (rword == RES_IF || rword == RES_ELIF)
8600 check_jobs_and_continue:
8601 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8602 dont_check_jobs_but_continue: ;
8603 #if ENABLE_HUSH_LOOPS
8604 /* Beware of "while false; true; do ..."! */
8606 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8607 /* check for RES_DONE is needed for "while ...; do \n done" case */
8609 if (rword == RES_WHILE) {
8611 /* "while false; do...done" - exitcode 0 */
8612 G.last_exitcode = rcode = EXIT_SUCCESS;
8613 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8617 if (rword == RES_UNTIL) {
8619 debug_printf_exec(": until expr is true: breaking\n");
8630 #if ENABLE_HUSH_LOOPS
8635 #if ENABLE_HUSH_CASE
8639 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8643 /* Select which version we will use */
8644 static int run_and_free_list(struct pipe *pi)
8647 debug_printf_exec("run_and_free_list entered\n");
8648 if (!G.o_opt[OPT_O_NOEXEC]) {
8649 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8650 rcode = run_list(pi);
8652 /* free_pipe_list has the side effect of clearing memory.
8653 * In the long run that function can be merged with run_list,
8654 * but doing that now would hobble the debugging effort. */
8656 debug_printf_exec("run_and_free_list return %d\n", rcode);
8661 static void install_sighandlers(unsigned mask)
8663 sighandler_t old_handler;
8665 while ((mask >>= 1) != 0) {
8669 old_handler = install_sighandler(sig, pick_sighandler(sig));
8670 /* POSIX allows shell to re-enable SIGCHLD
8671 * even if it was SIG_IGN on entry.
8672 * Therefore we skip IGN check for it:
8676 /* bash re-enables SIGHUP which is SIG_IGNed on entry.
8677 * Try: "trap '' HUP; bash; echo RET" and type "kill -HUP $$"
8679 //if (sig == SIGHUP) continue; - TODO?
8680 if (old_handler == SIG_IGN) {
8681 /* oops... restore back to IGN, and record this fact */
8682 install_sighandler(sig, old_handler);
8683 #if ENABLE_HUSH_TRAP
8685 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8687 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8693 /* Called a few times only (or even once if "sh -c") */
8694 static void install_special_sighandlers(void)
8698 /* Which signals are shell-special? */
8699 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8700 if (G_interactive_fd) {
8701 mask |= SPECIAL_INTERACTIVE_SIGS;
8702 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8703 mask |= SPECIAL_JOBSTOP_SIGS;
8705 /* Careful, do not re-install handlers we already installed */
8706 if (G.special_sig_mask != mask) {
8707 unsigned diff = mask & ~G.special_sig_mask;
8708 G.special_sig_mask = mask;
8709 install_sighandlers(diff);
8715 /* Set handlers to restore tty pgrp and exit */
8716 static void install_fatal_sighandlers(void)
8720 /* We will restore tty pgrp on these signals */
8722 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8723 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8724 + (1 << SIGBUS ) * HUSH_DEBUG
8725 + (1 << SIGSEGV) * HUSH_DEBUG
8726 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8728 /* bash 3.2 seems to handle these just like 'fatal' ones */
8731 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8732 * if we aren't interactive... but in this case
8733 * we never want to restore pgrp on exit, and this fn is not called
8735 /*+ (1 << SIGHUP )*/
8736 /*+ (1 << SIGTERM)*/
8737 /*+ (1 << SIGINT )*/
8739 G_fatal_sig_mask = mask;
8741 install_sighandlers(mask);
8745 static int set_mode(int state, char mode, const char *o_opt)
8750 G.o_opt[OPT_O_NOEXEC] = state;
8753 IF_HUSH_MODE_X(G_x_mode = state;)
8757 /* "set -+o" without parameter.
8758 * in bash, set -o produces this output:
8762 * We always use the second form.
8764 const char *p = o_opt_strings;
8767 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8773 idx = index_in_strings(o_opt_strings, o_opt);
8775 G.o_opt[idx] = state;
8779 G.o_opt[OPT_O_ERREXIT] = state;
8782 return EXIT_FAILURE;
8784 return EXIT_SUCCESS;
8787 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8788 int hush_main(int argc, char **argv)
8791 OPT_login = (1 << 0),
8795 unsigned builtin_argc;
8797 struct variable *cur_var;
8798 struct variable *shell_ver;
8801 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8802 G.last_exitcode = EXIT_SUCCESS;
8804 #if ENABLE_HUSH_FAST
8805 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8808 G.argv0_for_re_execing = argv[0];
8810 /* Deal with HUSH_VERSION */
8811 shell_ver = xzalloc(sizeof(*shell_ver));
8812 shell_ver->flg_export = 1;
8813 shell_ver->flg_read_only = 1;
8814 /* Code which handles ${var<op>...} needs writable values for all variables,
8815 * therefore we xstrdup: */
8816 shell_ver->varstr = xstrdup(hush_version_str);
8817 /* Create shell local variables from the values
8818 * currently living in the environment */
8819 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8820 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8821 G.top_var = shell_ver;
8822 cur_var = G.top_var;
8825 char *value = strchr(*e, '=');
8826 if (value) { /* paranoia */
8827 cur_var->next = xzalloc(sizeof(*cur_var));
8828 cur_var = cur_var->next;
8829 cur_var->varstr = *e;
8830 cur_var->max_len = strlen(*e);
8831 cur_var->flg_export = 1;
8835 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8836 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8837 putenv(shell_ver->varstr);
8840 set_pwd_var(SETFLAG_EXPORT);
8842 #if BASH_HOSTNAME_VAR
8843 /* Set (but not export) HOSTNAME unless already set */
8844 if (!get_local_var_value("HOSTNAME")) {
8847 set_local_var_from_halves("HOSTNAME", uts.nodename);
8849 /* bash also exports SHLVL and _,
8850 * and sets (but doesn't export) the following variables:
8852 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8853 * BASH_VERSION='3.2.0(1)-release'
8855 * MACHTYPE=i386-pc-linux-gnu
8857 * PPID=<NNNNN> - we also do it elsewhere
8868 * PIPESTATUS=([0]="0")
8869 * HISTFILE=/<xxx>/.bash_history
8873 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8875 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8886 #if ENABLE_FEATURE_EDITING
8887 G.line_input_state = new_line_input_t(FOR_SHELL);
8890 /* Initialize some more globals to non-zero values */
8891 cmdedit_update_prompt();
8893 die_func = restore_ttypgrp_and__exit;
8895 /* Shell is non-interactive at first. We need to call
8896 * install_special_sighandlers() if we are going to execute "sh <script>",
8897 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8898 * If we later decide that we are interactive, we run install_special_sighandlers()
8899 * in order to intercept (more) signals.
8903 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8904 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8907 opt = getopt(argc, argv, "+c:exinsl"
8910 # if ENABLE_HUSH_FUNCTIONS
8920 * sh ... -c 'script'
8921 * sh ... -c 'script' ARG0 [ARG1...]
8922 * On NOMMU, if builtin_argc != 0,
8923 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8924 * "" needs to be replaced with NULL
8925 * and BARGV vector fed to builtin function.
8926 * Note: the form without ARG0 never happens:
8927 * sh ... -c 'builtin' BARGV... ""
8930 G.root_pid = getpid();
8931 G.root_ppid = getppid();
8933 G.global_argv = argv + optind;
8934 G.global_argc = argc - optind;
8936 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8937 const struct built_in_command *x;
8939 install_special_sighandlers();
8940 x = find_builtin(optarg);
8941 if (x) { /* paranoia */
8942 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8943 G.global_argv += builtin_argc;
8944 G.global_argv[-1] = NULL; /* replace "" */
8946 G.last_exitcode = x->b_function(argv + optind - 1);
8950 if (!G.global_argv[0]) {
8951 /* -c 'script' (no params): prevent empty $0 */
8952 G.global_argv--; /* points to argv[i] of 'script' */
8953 G.global_argv[0] = argv[0];
8955 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8956 install_special_sighandlers();
8957 parse_and_run_string(optarg);
8960 /* Well, we cannot just declare interactiveness,
8961 * we have to have some stuff (ctty, etc) */
8962 /* G_interactive_fd++; */
8965 /* "-s" means "read from stdin", but this is how we always
8966 * operate, so simply do nothing here. */
8972 case '<': /* "big heredoc" support */
8973 full_write1_str(optarg);
8976 unsigned long long empty_trap_mask;
8978 G.root_pid = bb_strtou(optarg, &optarg, 16);
8980 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8982 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8984 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8986 builtin_argc = bb_strtou(optarg, &optarg, 16);
8988 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8989 if (empty_trap_mask != 0) {
8990 IF_HUSH_TRAP(int sig;)
8991 install_special_sighandlers();
8992 # if ENABLE_HUSH_TRAP
8993 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8994 for (sig = 1; sig < NSIG; sig++) {
8995 if (empty_trap_mask & (1LL << sig)) {
8996 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8997 install_sighandler(sig, SIG_IGN);
9002 # if ENABLE_HUSH_LOOPS
9004 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
9010 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
9012 # if ENABLE_HUSH_FUNCTIONS
9014 struct function *funcp = new_function(optarg);
9015 /* funcp->name is already set to optarg */
9016 /* funcp->body is set to NULL. It's a special case. */
9017 funcp->body_as_string = argv[optind];
9026 if (set_mode(1, opt, NULL) == 0) /* no error */
9030 fprintf(stderr, "Usage: sh [FILE]...\n"
9031 " or: sh -c command [args]...\n\n");
9037 } /* option parsing loop */
9039 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9040 G.global_argc = argc - (optind - 1);
9041 G.global_argv = argv + (optind - 1);
9042 G.global_argv[0] = argv[0];
9045 G.root_pid = getpid();
9046 G.root_ppid = getppid();
9049 /* If we are login shell... */
9050 if (flags & OPT_login) {
9052 debug_printf("sourcing /etc/profile\n");
9053 input = fopen_for_read("/etc/profile");
9054 if (input != NULL) {
9055 remember_FILE(input);
9056 install_special_sighandlers();
9057 parse_and_run_file(input);
9058 fclose_and_forget(input);
9060 /* bash: after sourcing /etc/profile,
9061 * tries to source (in the given order):
9062 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9063 * stopping on first found. --noprofile turns this off.
9064 * bash also sources ~/.bash_logout on exit.
9065 * If called as sh, skips .bash_XXX files.
9069 if (G.global_argv[1]) {
9072 * "bash <script>" (which is never interactive (unless -i?))
9073 * sources $BASH_ENV here (without scanning $PATH).
9074 * If called as sh, does the same but with $ENV.
9075 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9079 debug_printf("running script '%s'\n", G.global_argv[0]);
9080 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9081 input = xfopen_for_read(G.global_argv[0]);
9082 xfunc_error_retval = 1;
9083 remember_FILE(input);
9084 install_special_sighandlers();
9085 parse_and_run_file(input);
9086 #if ENABLE_FEATURE_CLEAN_UP
9087 fclose_and_forget(input);
9092 /* Up to here, shell was non-interactive. Now it may become one.
9093 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9096 /* A shell is interactive if the '-i' flag was given,
9097 * or if all of the following conditions are met:
9099 * no arguments remaining or the -s flag given
9100 * standard input is a terminal
9101 * standard output is a terminal
9102 * Refer to Posix.2, the description of the 'sh' utility.
9105 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9106 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9107 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9108 if (G_saved_tty_pgrp < 0)
9109 G_saved_tty_pgrp = 0;
9111 /* try to dup stdin to high fd#, >= 255 */
9112 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9113 if (G_interactive_fd < 0) {
9114 /* try to dup to any fd */
9115 G_interactive_fd = dup(STDIN_FILENO);
9116 if (G_interactive_fd < 0) {
9118 G_interactive_fd = 0;
9119 G_saved_tty_pgrp = 0;
9122 // TODO: track & disallow any attempts of user
9123 // to (inadvertently) close/redirect G_interactive_fd
9125 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9126 if (G_interactive_fd) {
9127 close_on_exec_on(G_interactive_fd);
9129 if (G_saved_tty_pgrp) {
9130 /* If we were run as 'hush &', sleep until we are
9131 * in the foreground (tty pgrp == our pgrp).
9132 * If we get started under a job aware app (like bash),
9133 * make sure we are now in charge so we don't fight over
9134 * who gets the foreground */
9136 pid_t shell_pgrp = getpgrp();
9137 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9138 if (G_saved_tty_pgrp == shell_pgrp)
9140 /* send TTIN to ourself (should stop us) */
9141 kill(- shell_pgrp, SIGTTIN);
9145 /* Install more signal handlers */
9146 install_special_sighandlers();
9148 if (G_saved_tty_pgrp) {
9149 /* Set other signals to restore saved_tty_pgrp */
9150 install_fatal_sighandlers();
9151 /* Put ourselves in our own process group
9152 * (bash, too, does this only if ctty is available) */
9153 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9154 /* Grab control of the terminal */
9155 tcsetpgrp(G_interactive_fd, getpid());
9157 enable_restore_tty_pgrp_on_exit();
9159 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9161 const char *hp = get_local_var_value("HISTFILE");
9163 hp = get_local_var_value("HOME");
9165 hp = concat_path_file(hp, ".hush_history");
9170 G.line_input_state->hist_file = hp;
9171 //set_local_var(xasprintf("HISTFILE=%s", ...));
9173 # if ENABLE_FEATURE_SH_HISTFILESIZE
9174 hp = get_local_var_value("HISTFILESIZE");
9175 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9180 install_special_sighandlers();
9182 #elif ENABLE_HUSH_INTERACTIVE
9183 /* No job control compiled in, only prompt/line editing */
9184 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9185 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9186 if (G_interactive_fd < 0) {
9187 /* try to dup to any fd */
9188 G_interactive_fd = dup(STDIN_FILENO);
9189 if (G_interactive_fd < 0)
9191 G_interactive_fd = 0;
9194 if (G_interactive_fd) {
9195 close_on_exec_on(G_interactive_fd);
9197 install_special_sighandlers();
9199 /* We have interactiveness code disabled */
9200 install_special_sighandlers();
9203 * if interactive but not a login shell, sources ~/.bashrc
9204 * (--norc turns this off, --rcfile <file> overrides)
9207 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9208 /* note: ash and hush share this string */
9209 printf("\n\n%s %s\n"
9210 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9213 "hush - the humble shell"
9217 parse_and_run_file(stdin);
9220 hush_exit(G.last_exitcode);
9227 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9232 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9233 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9235 int argc = string_array_len(argv);
9236 return applet_main_func(argc, argv);
9239 #if ENABLE_HUSH_TEST || BASH_TEST2
9240 static int FAST_FUNC builtin_test(char **argv)
9242 return run_applet_main(argv, test_main);
9245 #if ENABLE_HUSH_ECHO
9246 static int FAST_FUNC builtin_echo(char **argv)
9248 return run_applet_main(argv, echo_main);
9251 #if ENABLE_HUSH_PRINTF
9252 static int FAST_FUNC builtin_printf(char **argv)
9254 return run_applet_main(argv, printf_main);
9258 #if ENABLE_HUSH_HELP
9259 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9261 const struct built_in_command *x;
9264 "Built-in commands:\n"
9265 "------------------\n");
9266 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9268 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9270 return EXIT_SUCCESS;
9274 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9275 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9277 show_history(G.line_input_state);
9278 return EXIT_SUCCESS;
9282 static char **skip_dash_dash(char **argv)
9285 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9290 static int FAST_FUNC builtin_cd(char **argv)
9294 argv = skip_dash_dash(argv);
9296 if (newdir == NULL) {
9297 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9298 * bash says "bash: cd: HOME not set" and does nothing
9301 const char *home = get_local_var_value("HOME");
9302 newdir = home ? home : "/";
9304 if (chdir(newdir)) {
9305 /* Mimic bash message exactly */
9306 bb_perror_msg("cd: %s", newdir);
9307 return EXIT_FAILURE;
9309 /* Read current dir (get_cwd(1) is inside) and set PWD.
9310 * Note: do not enforce exporting. If PWD was unset or unexported,
9311 * set it again, but do not export. bash does the same.
9313 set_pwd_var(/*flag:*/ 0);
9314 return EXIT_SUCCESS;
9317 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9320 return EXIT_SUCCESS;
9323 static int FAST_FUNC builtin_eval(char **argv)
9325 int rcode = EXIT_SUCCESS;
9327 argv = skip_dash_dash(argv);
9329 char *str = expand_strvec_to_string(argv);
9331 * eval "echo Hi; done" ("done" is syntax error):
9332 * "echo Hi" will not execute too.
9334 parse_and_run_string(str);
9336 rcode = G.last_exitcode;
9341 static int FAST_FUNC builtin_exec(char **argv)
9343 argv = skip_dash_dash(argv);
9344 if (argv[0] == NULL)
9345 return EXIT_SUCCESS; /* bash does this */
9347 /* Careful: we can end up here after [v]fork. Do not restore
9348 * tty pgrp then, only top-level shell process does that */
9349 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9350 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9352 /* Saved-redirect fds, script fds and G_interactive_fd are still
9353 * open here. However, they are all CLOEXEC, and execv below
9354 * closes them. Try interactive "exec ls -l /proc/self/fd",
9355 * it should show no extra open fds in the "ls" process.
9356 * If we'd try to run builtins/NOEXECs, this would need improving.
9358 //close_saved_fds_and_FILE_fds();
9360 /* TODO: if exec fails, bash does NOT exit! We do.
9361 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9362 * and tcsetpgrp, and this is inherently racy.
9364 execvp_or_die(argv);
9367 static int FAST_FUNC builtin_exit(char **argv)
9369 debug_printf_exec("%s()\n", __func__);
9371 /* interactive bash:
9372 * # trap "echo EEE" EXIT
9375 * There are stopped jobs.
9376 * (if there are _stopped_ jobs, running ones don't count)
9379 * EEE (then bash exits)
9381 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9384 /* note: EXIT trap is run by hush_exit */
9385 argv = skip_dash_dash(argv);
9386 if (argv[0] == NULL)
9387 hush_exit(G.last_exitcode);
9388 /* mimic bash: exit 123abc == exit 255 + error msg */
9389 xfunc_error_retval = 255;
9390 /* bash: exit -2 == exit 254, no error msg */
9391 hush_exit(xatoi(argv[0]) & 0xff);
9394 #if ENABLE_HUSH_TYPE
9395 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9396 static int FAST_FUNC builtin_type(char **argv)
9398 int ret = EXIT_SUCCESS;
9404 if (0) {} /* make conditional compile easier below */
9405 /*else if (find_alias(*argv))
9406 type = "an alias";*/
9407 #if ENABLE_HUSH_FUNCTIONS
9408 else if (find_function(*argv))
9409 type = "a function";
9411 else if (find_builtin(*argv))
9412 type = "a shell builtin";
9413 else if ((path = find_in_path(*argv)) != NULL)
9416 bb_error_msg("type: %s: not found", *argv);
9421 printf("%s is %s\n", *argv, type);
9429 #if ENABLE_HUSH_READ
9430 /* Interruptibility of read builtin in bash
9431 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9433 * Empty trap makes read ignore corresponding signal, for any signal.
9436 * - terminates non-interactive shell;
9437 * - interrupts read in interactive shell;
9438 * if it has non-empty trap:
9439 * - executes trap and returns to command prompt in interactive shell;
9440 * - executes trap and returns to read in non-interactive shell;
9442 * - is ignored (does not interrupt) read in interactive shell;
9443 * - terminates non-interactive shell;
9444 * if it has non-empty trap:
9445 * - executes trap and returns to read;
9447 * - terminates shell (regardless of interactivity);
9448 * if it has non-empty trap:
9449 * - executes trap and returns to read;
9450 * SIGCHLD from children:
9451 * - does not interrupt read regardless of interactivity:
9452 * try: sleep 1 & read x; echo $x
9454 static int FAST_FUNC builtin_read(char **argv)
9461 char *opt_d = NULL; /* optimized out if !BASH */
9465 /* "!": do not abort on errors.
9466 * Option string must start with "sr" to match BUILTIN_READ_xxx
9468 read_flags = getopt32(argv,
9470 "!srn:p:t:u:d:", &opt_n, &opt_p, &opt_t, &opt_u, &opt_d
9472 "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u
9475 if (read_flags == (uint32_t)-1)
9476 return EXIT_FAILURE;
9478 ifs = get_local_var_value("IFS"); /* can be NULL */
9481 r = shell_builtin_read(set_local_var_from_halves,
9492 if ((uintptr_t)r == 1 && errno == EINTR) {
9493 unsigned sig = check_and_run_traps();
9498 if ((uintptr_t)r > 1) {
9499 bb_error_msg("%s", r);
9500 r = (char*)(uintptr_t)1;
9503 return (uintptr_t)r;
9507 #if ENABLE_HUSH_UMASK
9508 static int FAST_FUNC builtin_umask(char **argv)
9515 argv = skip_dash_dash(argv);
9517 mode_t old_mask = mask;
9519 /* numeric umasks are taken as-is */
9520 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9521 if (!isdigit(argv[0][0]))
9523 mask = bb_parse_mode(argv[0], mask);
9524 if (!isdigit(argv[0][0]))
9526 if ((unsigned)mask > 0777) {
9529 * bash: umask: 'q': invalid symbolic mode operator
9530 * bash: umask: 999: octal number out of range
9532 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9537 printf("%04o\n", (unsigned) mask);
9538 /* fall through and restore mask which we set to 0 */
9542 return !rc; /* rc != 0 - success */
9546 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9547 static void print_escaped(const char *s)
9552 const char *p = strchrnul(s, '\'');
9553 /* print 'xxxx', possibly just '' */
9554 printf("'%.*s'", (int)(p - s), s);
9559 /* s points to '; print "'''...'''" */
9561 do putchar('\''); while (*++s == '\'');
9567 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9568 static int helper_export_local(char **argv, unsigned flags)
9572 char *name_end = strchrnul(name, '=');
9574 /* So far we do not check that name is valid (TODO?) */
9576 if (*name_end == '\0') {
9577 struct variable *var, **vpp;
9579 vpp = get_ptr_to_local_var(name, name_end - name);
9580 var = vpp ? *vpp : NULL;
9582 if (flags & SETFLAG_UNEXPORT) {
9583 /* export -n NAME (without =VALUE) */
9585 var->flg_export = 0;
9586 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9588 } /* else: export -n NOT_EXISTING_VAR: no-op */
9591 if (flags & SETFLAG_EXPORT) {
9592 /* export NAME (without =VALUE) */
9594 var->flg_export = 1;
9595 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9596 putenv(var->varstr);
9600 if (flags & SETFLAG_MAKE_RO) {
9601 /* readonly NAME (without =VALUE) */
9603 var->flg_read_only = 1;
9607 # if ENABLE_HUSH_LOCAL
9608 /* Is this "local" bltin? */
9609 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9610 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9611 if (var && var->func_nest_level == lvl) {
9612 /* "local x=abc; ...; local x" - ignore second local decl */
9617 /* Exporting non-existing variable.
9618 * bash does not put it in environment,
9619 * but remembers that it is exported,
9620 * and does put it in env when it is set later.
9621 * We just set it to "" and export.
9623 /* Or, it's "local NAME" (without =VALUE).
9624 * bash sets the value to "".
9626 /* Or, it's "readonly NAME" (without =VALUE).
9627 * bash remembers NAME and disallows its creation
9630 name = xasprintf("%s=", name);
9632 /* (Un)exporting/making local NAME=VALUE */
9633 name = xstrdup(name);
9635 if (set_local_var(name, flags))
9636 return EXIT_FAILURE;
9638 return EXIT_SUCCESS;
9642 #if ENABLE_HUSH_EXPORT
9643 static int FAST_FUNC builtin_export(char **argv)
9645 unsigned opt_unexport;
9647 #if ENABLE_HUSH_EXPORT_N
9648 /* "!": do not abort on errors */
9649 opt_unexport = getopt32(argv, "!n");
9650 if (opt_unexport == (uint32_t)-1)
9651 return EXIT_FAILURE;
9658 if (argv[0] == NULL) {
9665 /* ash emits: export VAR='VAL'
9666 * bash: declare -x VAR="VAL"
9667 * we follow ash example */
9668 const char *s = *e++;
9669 const char *p = strchr(s, '=');
9671 if (!p) /* wtf? take next variable */
9674 printf("export %.*s", (int)(p - s) + 1, s);
9675 print_escaped(p + 1);
9679 /*fflush_all(); - done after each builtin anyway */
9681 return EXIT_SUCCESS;
9684 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9688 #if ENABLE_HUSH_LOCAL
9689 static int FAST_FUNC builtin_local(char **argv)
9691 if (G.func_nest_level == 0) {
9692 bb_error_msg("%s: not in a function", argv[0]);
9693 return EXIT_FAILURE; /* bash compat */
9696 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9700 #if ENABLE_HUSH_READONLY
9701 static int FAST_FUNC builtin_readonly(char **argv)
9704 if (*argv == NULL) {
9705 /* bash: readonly [-p]: list all readonly VARs
9706 * (-p has no effect in bash)
9709 for (e = G.top_var; e; e = e->next) {
9710 if (e->flg_read_only) {
9711 //TODO: quote value: readonly VAR='VAL'
9712 printf("readonly %s\n", e->varstr);
9715 return EXIT_SUCCESS;
9717 return helper_export_local(argv, SETFLAG_MAKE_RO);
9721 #if ENABLE_HUSH_UNSET
9722 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9723 static int FAST_FUNC builtin_unset(char **argv)
9728 /* "!": do not abort on errors */
9729 /* "+": stop at 1st non-option */
9730 opts = getopt32(argv, "!+vf");
9731 if (opts == (unsigned)-1)
9732 return EXIT_FAILURE;
9734 bb_error_msg("unset: -v and -f are exclusive");
9735 return EXIT_FAILURE;
9741 if (!(opts & 2)) { /* not -f */
9742 if (unset_local_var(*argv)) {
9743 /* unset <nonexistent_var> doesn't fail.
9744 * Error is when one tries to unset RO var.
9745 * Message was printed by unset_local_var. */
9749 # if ENABLE_HUSH_FUNCTIONS
9761 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9762 * built-in 'set' handler
9764 * set [-abCefhmnuvx] [-o option] [argument...]
9765 * set [+abCefhmnuvx] [+o option] [argument...]
9766 * set -- [argument...]
9769 * Implementations shall support the options in both their hyphen and
9770 * plus-sign forms. These options can also be specified as options to sh.
9772 * Write out all variables and their values: set
9773 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9774 * Turn on the -x and -v options: set -xv
9775 * Unset all positional parameters: set --
9776 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9777 * Set the positional parameters to the expansion of x, even if x expands
9778 * with a leading '-' or '+': set -- $x
9780 * So far, we only support "set -- [argument...]" and some of the short names.
9782 static int FAST_FUNC builtin_set(char **argv)
9785 char **pp, **g_argv;
9786 char *arg = *++argv;
9790 for (e = G.top_var; e; e = e->next)
9792 return EXIT_SUCCESS;
9796 if (strcmp(arg, "--") == 0) {
9800 if (arg[0] != '+' && arg[0] != '-')
9802 for (n = 1; arg[n]; ++n) {
9803 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9805 if (arg[n] == 'o' && argv[1])
9808 } while ((arg = *++argv) != NULL);
9809 /* Now argv[0] is 1st argument */
9812 return EXIT_SUCCESS;
9815 /* NB: G.global_argv[0] ($0) is never freed/changed */
9816 g_argv = G.global_argv;
9817 if (G.global_args_malloced) {
9823 G.global_args_malloced = 1;
9824 pp = xzalloc(sizeof(pp[0]) * 2);
9825 pp[0] = g_argv[0]; /* retain $0 */
9828 /* This realloc's G.global_argv */
9829 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9831 G.global_argc = 1 + string_array_len(pp + 1);
9833 return EXIT_SUCCESS;
9835 /* Nothing known, so abort */
9837 bb_error_msg("set: %s: invalid option", arg);
9838 return EXIT_FAILURE;
9842 static int FAST_FUNC builtin_shift(char **argv)
9845 argv = skip_dash_dash(argv);
9847 n = bb_strtou(argv[0], NULL, 10);
9848 if (errno || n < 0) {
9849 /* shared string with ash.c */
9850 bb_error_msg("Illegal number: %s", argv[0]);
9852 * ash aborts in this case.
9853 * bash prints error message and set $? to 1.
9854 * Interestingly, for "shift 99999" bash does not
9855 * print error message, but does set $? to 1
9856 * (and does no shifting at all).
9860 if (n >= 0 && n < G.global_argc) {
9861 if (G_global_args_malloced) {
9864 free(G.global_argv[m++]);
9867 memmove(&G.global_argv[1], &G.global_argv[n+1],
9868 G.global_argc * sizeof(G.global_argv[0]));
9869 return EXIT_SUCCESS;
9871 return EXIT_FAILURE;
9874 #if ENABLE_HUSH_GETOPTS
9875 static int FAST_FUNC builtin_getopts(char **argv)
9877 /* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/getopts.html
9880 If a required argument is not found, and getopts is not silent,
9881 a question mark (?) is placed in VAR, OPTARG is unset, and a
9882 diagnostic message is printed. If getopts is silent, then a
9883 colon (:) is placed in VAR and OPTARG is set to the option
9886 Test that VAR is a valid variable name?
9888 "Whenever the shell is invoked, OPTIND shall be initialized to 1"
9891 const char *cp, *optstring, *var;
9894 optstring = *++argv;
9895 if (!optstring || !(var = *++argv)) {
9896 bb_error_msg("usage: getopts OPTSTRING VAR [ARGS]");
9897 return EXIT_FAILURE;
9900 if (optstring[0] == ':') {
9903 cp = get_local_var_value("OPTERR");
9904 opterr = cp ? atoi(cp) : 1;
9906 cp = get_local_var_value("OPTIND");
9907 optind = cp ? atoi(cp) : 0;
9911 /* getopts stops on first non-option. Add "+" to force that */
9912 /*if (optstring[0] != '+')*/ {
9913 char *s = alloca(strlen(optstring) + 2);
9914 sprintf(s, "+%s", optstring);
9919 argv[0] = G.global_argv[0]; /* for error messages */
9921 argv = G.global_argv;
9922 c = getopt(string_array_len(argv), argv, optstring);
9925 /* Always set or unset, never left as-is, even on exit/error:
9926 * "If no option was found, or if the option that was found
9927 * does not have an option-argument, OPTARG shall be unset."
9931 /* If ":optstring" and unknown option is seen,
9932 * it is stored to OPTARG.
9934 if (optstring[1] == ':') {
9940 set_local_var_from_halves("OPTARG", cp);
9942 unset_local_var("OPTARG");
9944 /* Convert -1 to "?" */
9945 exitcode = EXIT_SUCCESS;
9946 if (c < 0) { /* -1: end of options */
9947 exitcode = EXIT_FAILURE;
9951 /* Set VAR and OPTIND */
9953 set_local_var_from_halves(var, cbuf);
9954 set_local_var_from_halves("OPTIND", utoa(optind));
9960 static int FAST_FUNC builtin_source(char **argv)
9962 char *arg_path, *filename;
9965 char *args_need_save;
9966 #if ENABLE_HUSH_FUNCTIONS
9970 argv = skip_dash_dash(argv);
9973 /* bash says: "bash: .: filename argument required" */
9974 return 2; /* bash compat */
9977 if (!strchr(filename, '/')) {
9978 arg_path = find_in_path(filename);
9980 filename = arg_path;
9982 input = remember_FILE(fopen_or_warn(filename, "r"));
9985 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9986 /* POSIX: non-interactive shell should abort here,
9987 * not merely fail. So far no one complained :)
9989 return EXIT_FAILURE;
9992 #if ENABLE_HUSH_FUNCTIONS
9993 sv_flg = G_flag_return_in_progress;
9994 /* "we are inside sourced file, ok to use return" */
9995 G_flag_return_in_progress = -1;
9997 args_need_save = argv[1]; /* used as a boolean variable */
9999 save_and_replace_G_args(&sv, argv);
10001 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
10002 G.last_exitcode = 0;
10003 parse_and_run_file(input);
10004 fclose_and_forget(input);
10006 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
10007 restore_G_args(&sv, argv);
10008 #if ENABLE_HUSH_FUNCTIONS
10009 G_flag_return_in_progress = sv_flg;
10012 return G.last_exitcode;
10015 #if ENABLE_HUSH_TRAP
10016 static int FAST_FUNC builtin_trap(char **argv)
10022 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
10027 /* No args: print all trapped */
10028 for (i = 0; i < NSIG; ++i) {
10030 printf("trap -- ");
10031 print_escaped(G_traps[i]);
10032 /* note: bash adds "SIG", but only if invoked
10033 * as "bash". If called as "sh", or if set -o posix,
10034 * then it prints short signal names.
10035 * We are printing short names: */
10036 printf(" %s\n", get_signame(i));
10039 /*fflush_all(); - done after each builtin anyway */
10040 return EXIT_SUCCESS;
10044 /* If first arg is a number: reset all specified signals */
10045 sig = bb_strtou(*argv, NULL, 10);
10049 ret = EXIT_SUCCESS;
10051 sighandler_t handler;
10053 sig = get_signum(*argv++);
10055 ret = EXIT_FAILURE;
10056 /* Mimic bash message exactly */
10057 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
10061 free(G_traps[sig]);
10062 G_traps[sig] = xstrdup(new_cmd);
10064 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
10065 get_signame(sig), sig, G_traps[sig]);
10067 /* There is no signal for 0 (EXIT) */
10072 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
10074 /* We are removing trap handler */
10075 handler = pick_sighandler(sig);
10076 install_sighandler(sig, handler);
10081 if (!argv[1]) { /* no second arg */
10082 bb_error_msg("trap: invalid arguments");
10083 return EXIT_FAILURE;
10086 /* First arg is "-": reset all specified to default */
10087 /* First arg is "--": skip it, the rest is "handler SIGs..." */
10088 /* Everything else: set arg as signal handler
10089 * (includes "" case, which ignores signal) */
10090 if (argv[0][0] == '-') {
10091 if (argv[0][1] == '\0') { /* "-" */
10092 /* new_cmd remains NULL: "reset these sigs" */
10095 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
10098 /* else: "-something", no special meaning */
10103 goto process_sig_list;
10107 #if ENABLE_HUSH_JOB
10108 static struct pipe *parse_jobspec(const char *str)
10113 if (sscanf(str, "%%%u", &jobnum) != 1) {
10115 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
10117 bb_error_msg("bad argument '%s'", str);
10120 /* It is "%%", "%+" or "%" - current job */
10121 jobnum = G.last_jobid;
10123 bb_error_msg("no current job");
10127 for (pi = G.job_list; pi; pi = pi->next) {
10128 if (pi->jobid == jobnum) {
10132 bb_error_msg("%u: no such job", jobnum);
10136 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10139 const char *status_string;
10141 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10142 for (job = G.job_list; job; job = job->next) {
10143 if (job->alive_cmds == job->stopped_cmds)
10144 status_string = "Stopped";
10146 status_string = "Running";
10148 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10151 clean_up_last_dead_job();
10153 return EXIT_SUCCESS;
10156 /* built-in 'fg' and 'bg' handler */
10157 static int FAST_FUNC builtin_fg_bg(char **argv)
10162 if (!G_interactive_fd)
10163 return EXIT_FAILURE;
10165 /* If they gave us no args, assume they want the last backgrounded task */
10167 for (pi = G.job_list; pi; pi = pi->next) {
10168 if (pi->jobid == G.last_jobid) {
10172 bb_error_msg("%s: no current job", argv[0]);
10173 return EXIT_FAILURE;
10176 pi = parse_jobspec(argv[1]);
10178 return EXIT_FAILURE;
10180 /* TODO: bash prints a string representation
10181 * of job being foregrounded (like "sleep 1 | cat") */
10182 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10183 /* Put the job into the foreground. */
10184 tcsetpgrp(G_interactive_fd, pi->pgrp);
10187 /* Restart the processes in the job */
10188 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10189 for (i = 0; i < pi->num_cmds; i++) {
10190 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10192 pi->stopped_cmds = 0;
10194 i = kill(- pi->pgrp, SIGCONT);
10196 if (errno == ESRCH) {
10197 delete_finished_job(pi);
10198 return EXIT_SUCCESS;
10200 bb_perror_msg("kill (SIGCONT)");
10203 if (argv[0][0] == 'f') {
10204 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10205 return checkjobs_and_fg_shell(pi);
10207 return EXIT_SUCCESS;
10211 #if ENABLE_HUSH_KILL
10212 static int FAST_FUNC builtin_kill(char **argv)
10216 # if ENABLE_HUSH_JOB
10217 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10225 if (argv[i][0] != '%')
10228 * "kill %N" - job kill
10229 * Converting to pgrp / pid kill
10231 pi = parse_jobspec(argv[i]);
10233 /* Eat bad jobspec */
10237 argv[j - 1] = argv[j];
10244 * In jobs started under job control, we signal
10245 * entire process group by kill -PGRP_ID.
10246 * This happens, f.e., in interactive shell.
10248 * Otherwise, we signal each child via
10249 * kill PID1 PID2 PID3.
10251 * sh -c 'sleep 1|sleep 1 & kill %1'
10252 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10253 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10255 n = G_interactive_fd ? 1 : pi->num_cmds;
10256 dst = alloca(n * sizeof(int)*4);
10258 if (G_interactive_fd)
10259 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10260 else for (j = 0; j < n; j++) {
10261 struct command *cmd = &pi->cmds[j];
10262 /* Skip exited members of the job */
10266 * kill_main has matching code to expect
10267 * leading space. Needed to not confuse
10268 * negative pids with "kill -SIGNAL_NO" syntax
10270 dst += sprintf(dst, " %u", (int)cmd->pid);
10273 } while (argv[++i]);
10277 if (argv[1] || ret == 0) {
10278 ret = run_applet_main(argv, kill_main);
10280 /* else: ret = 1, "kill %bad_jobspec" case */
10285 #if ENABLE_HUSH_WAIT
10286 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10287 #if !ENABLE_HUSH_JOB
10288 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10290 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10297 if (!sigisemptyset(&G.pending_set))
10300 /* waitpid is not interruptible by SA_RESTARTed
10301 * signals which we use. Thus, this ugly dance:
10304 /* Make sure possible SIGCHLD is stored in kernel's
10305 * pending signal mask before we call waitpid.
10306 * Or else we may race with SIGCHLD, lose it,
10307 * and get stuck in sigsuspend...
10309 sigfillset(&oldset); /* block all signals, remember old set */
10310 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10312 if (!sigisemptyset(&G.pending_set)) {
10313 /* Crap! we raced with some signal! */
10317 /*errno = 0; - checkjobs does this */
10318 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10319 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10320 debug_printf_exec("checkjobs:%d\n", ret);
10321 #if ENABLE_HUSH_JOB
10322 if (waitfor_pipe) {
10323 int rcode = job_exited_or_stopped(waitfor_pipe);
10324 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10327 sigprocmask(SIG_SETMASK, &oldset, NULL);
10332 /* if ECHILD, there are no children (ret is -1 or 0) */
10333 /* if ret == 0, no children changed state */
10334 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10335 if (errno == ECHILD || ret) {
10337 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10339 sigprocmask(SIG_SETMASK, &oldset, NULL);
10342 /* Wait for SIGCHLD or any other signal */
10343 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10344 /* Note: sigsuspend invokes signal handler */
10345 sigsuspend(&oldset);
10347 sigprocmask(SIG_SETMASK, &oldset, NULL);
10349 /* So, did we get a signal? */
10350 sig = check_and_run_traps();
10351 if (sig /*&& sig != SIGCHLD - always true */) {
10352 /* Do this for any (non-ignored) signal, not only for ^C */
10356 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10361 static int FAST_FUNC builtin_wait(char **argv)
10366 argv = skip_dash_dash(argv);
10367 if (argv[0] == NULL) {
10368 /* Don't care about wait results */
10369 /* Note 1: must wait until there are no more children */
10370 /* Note 2: must be interruptible */
10372 * $ sleep 3 & sleep 6 & wait
10373 * [1] 30934 sleep 3
10374 * [2] 30935 sleep 6
10377 * $ sleep 3 & sleep 6 & wait
10378 * [1] 30936 sleep 3
10379 * [2] 30937 sleep 6
10381 * ^C <-- after ~4 sec from keyboard
10384 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10388 pid_t pid = bb_strtou(*argv, NULL, 10);
10389 if (errno || pid <= 0) {
10390 #if ENABLE_HUSH_JOB
10391 if (argv[0][0] == '%') {
10392 struct pipe *wait_pipe;
10393 ret = 127; /* bash compat for bad jobspecs */
10394 wait_pipe = parse_jobspec(*argv);
10396 ret = job_exited_or_stopped(wait_pipe);
10398 ret = wait_for_child_or_signal(wait_pipe, 0);
10400 /* waiting on "last dead job" removes it */
10401 clean_up_last_dead_job();
10404 /* else: parse_jobspec() already emitted error msg */
10408 /* mimic bash message */
10409 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10410 ret = EXIT_FAILURE;
10411 continue; /* bash checks all argv[] */
10414 /* Do we have such child? */
10415 ret = waitpid(pid, &status, WNOHANG);
10419 if (errno == ECHILD) {
10420 if (pid == G.last_bg_pid) {
10421 /* "wait $!" but last bg task has already exited. Try:
10422 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10423 * In bash it prints exitcode 0, then 3.
10424 * In dash, it is 127.
10426 ret = G.last_bg_pid_exitcode;
10428 /* Example: "wait 1". mimic bash message */
10429 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10433 bb_perror_msg("wait %s", *argv);
10435 continue; /* bash checks all argv[] */
10438 /* Yes, and it still runs */
10439 ret = wait_for_child_or_signal(NULL, pid);
10441 /* Yes, and it just exited */
10442 process_wait_result(NULL, pid, status);
10443 ret = WEXITSTATUS(status);
10444 if (WIFSIGNALED(status))
10445 ret = 128 + WTERMSIG(status);
10453 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10454 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10457 def = bb_strtou(argv[1], NULL, 10);
10458 if (errno || def < def_min || argv[2]) {
10459 bb_error_msg("%s: bad arguments", argv[0]);
10467 #if ENABLE_HUSH_LOOPS
10468 static int FAST_FUNC builtin_break(char **argv)
10471 if (G.depth_of_loop == 0) {
10472 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10473 /* if we came from builtin_continue(), need to undo "= 1" */
10474 G.flag_break_continue = 0;
10475 return EXIT_SUCCESS; /* bash compat */
10477 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10479 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10480 if (depth == UINT_MAX)
10481 G.flag_break_continue = BC_BREAK;
10482 if (G.depth_of_loop < depth)
10483 G.depth_break_continue = G.depth_of_loop;
10485 return EXIT_SUCCESS;
10488 static int FAST_FUNC builtin_continue(char **argv)
10490 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10491 return builtin_break(argv);
10495 #if ENABLE_HUSH_FUNCTIONS
10496 static int FAST_FUNC builtin_return(char **argv)
10500 if (G_flag_return_in_progress != -1) {
10501 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10502 return EXIT_FAILURE; /* bash compat */
10505 G_flag_return_in_progress = 1;
10508 * out of range: wraps around at 256, does not error out
10509 * non-numeric param:
10510 * f() { false; return qwe; }; f; echo $?
10511 * bash: return: qwe: numeric argument required <== we do this
10512 * 255 <== we also do this
10514 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10519 #if ENABLE_HUSH_TIMES
10520 static int FAST_FUNC builtin_times(char **argv UNUSED_PARAM)
10522 static const uint8_t times_tbl[] ALIGN1 = {
10523 ' ', offsetof(struct tms, tms_utime),
10524 '\n', offsetof(struct tms, tms_stime),
10525 ' ', offsetof(struct tms, tms_cutime),
10526 '\n', offsetof(struct tms, tms_cstime),
10533 clk_tck = bb_clk_tck();
10538 unsigned sec, frac;
10540 t = *(clock_t *)(((char *) &buf) + p[1]);
10542 frac = t % clk_tck;
10543 printf("%um%u.%03us%c",
10544 sec / 60, sec % 60,
10545 (frac * 1000) / clk_tck,
10550 return EXIT_SUCCESS;
10554 #if ENABLE_HUSH_MEMLEAK
10555 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10560 # ifdef M_TRIM_THRESHOLD
10561 /* Optional. Reduces probability of false positives */
10564 /* Crude attempt to find where "free memory" starts,
10565 * sans fragmentation. */
10567 l = (unsigned long)p;
10570 if (l < (unsigned long)p) l = (unsigned long)p;
10576 struct mallinfo mi = mallinfo();
10577 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10578 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10582 if (!G.memleak_value)
10583 G.memleak_value = l;
10585 l -= G.memleak_value;
10592 /* Exitcode is "how many kilobytes we leaked since 1st call" */