1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
88 //config: hush is a small shell (25k). It handles the normal flow control
89 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
90 //config: case/esac. Redirections, here documents, $((arithmetic))
91 //config: and functions are supported.
93 //config: It will compile and work on no-mmu systems.
95 //config: It does not handle select, aliases, tilde expansion,
96 //config: &>file and >&file redirection of stdout+stderr.
98 //config:config HUSH_BASH_COMPAT
99 //config: bool "bash-compatible extensions"
101 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
103 //config:config HUSH_BRACE_EXPANSION
104 //config: bool "Brace expansion"
106 //config: depends on HUSH_BASH_COMPAT
108 //config: Enable {abc,def} extension.
110 //config:config HUSH_INTERACTIVE
111 //config: bool "Interactive mode"
113 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
115 //config: Enable interactive mode (prompt and command editing).
116 //config: Without this, hush simply reads and executes commands
117 //config: from stdin just like a shell script from a file.
118 //config: No prompt, no PS1/PS2 magic shell variables.
120 //config:config HUSH_SAVEHISTORY
121 //config: bool "Save command history to .hush_history"
123 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
125 //config:config HUSH_JOB
126 //config: bool "Job control"
128 //config: depends on HUSH_INTERACTIVE
130 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
131 //config: command (not entire shell), fg/bg builtins work. Without this option,
132 //config: "cmd &" still works by simply spawning a process and immediately
133 //config: prompting for next command (or executing next command in a script),
134 //config: but no separate process group is formed.
136 //config:config HUSH_TICK
137 //config: bool "Support process substitution"
139 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
141 //config: Enable `command` and $(command).
143 //config:config HUSH_IF
144 //config: bool "Support if/then/elif/else/fi"
146 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
148 //config:config HUSH_LOOPS
149 //config: bool "Support for, while and until loops"
151 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
153 //config:config HUSH_CASE
154 //config: bool "Support case ... esac statement"
156 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
158 //config: Enable case ... esac statement. +400 bytes.
160 //config:config HUSH_FUNCTIONS
161 //config: bool "Support funcname() { commands; } syntax"
163 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
165 //config: Enable support for shell functions. +800 bytes.
167 //config:config HUSH_LOCAL
168 //config: bool "local builtin"
170 //config: depends on HUSH_FUNCTIONS
172 //config: Enable support for local variables in functions.
174 //config:config HUSH_RANDOM_SUPPORT
175 //config: bool "Pseudorandom generator and $RANDOM variable"
177 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
179 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
180 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
182 //config:config HUSH_MODE_X
183 //config: bool "Support 'hush -x' option and 'set -x' command"
185 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
187 //config: This instructs hush to print commands before execution.
188 //config: Adds ~300 bytes.
190 //config:config HUSH_ECHO
191 //config: bool "echo builtin"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config:config HUSH_PRINTF
196 //config: bool "printf builtin"
198 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
200 //config:config HUSH_TEST
201 //config: bool "test builtin"
203 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
205 //config:config HUSH_HELP
206 //config: bool "help builtin"
208 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
210 //config:config HUSH_EXPORT
211 //config: bool "export builtin"
213 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
215 //config:config HUSH_EXPORT_N
216 //config: bool "Support 'export -n' option"
218 //config: depends on HUSH_EXPORT
220 //config: export -n unexports variables. It is a bash extension.
222 //config:config HUSH_KILL
223 //config: bool "kill builtin (supports kill %jobspec)"
225 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
227 //config:config HUSH_WAIT
228 //config: bool "wait builtin"
230 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
232 //config:config HUSH_TRAP
233 //config: bool "trap builtin"
235 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
237 //config:config HUSH_TYPE
238 //config: bool "type builtin"
240 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
242 //config:config HUSH_READ
243 //config: bool "read builtin"
245 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
247 //config:config HUSH_SET
248 //config: bool "set builtin"
250 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
252 //config:config HUSH_UNSET
253 //config: bool "unset builtin"
255 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
257 //config:config HUSH_ULIMIT
258 //config: bool "ulimit builtin"
260 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
262 //config:config HUSH_UMASK
263 //config: bool "umask builtin"
265 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
267 //config:config HUSH_MEMLEAK
268 //config: bool "memleak builtin (debugging)"
270 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config: bool "msh (deprecated: aliased to hush)"
275 //config: select HUSH
277 //config: msh is deprecated and will be removed, please migrate to hush.
279 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
280 //applet:IF_MSH(APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
281 //applet:IF_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
282 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
284 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
285 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
286 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
287 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
289 /* -i (interactive) and -s (read stdin) are also accepted,
290 * but currently do nothing, therefore aren't shown in help.
291 * NOMMU-specific options are not meant to be used by users,
292 * therefore we don't show them either.
294 //usage:#define hush_trivial_usage
295 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
296 //usage:#define hush_full_usage "\n\n"
297 //usage: "Unix shell interpreter"
299 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
300 || defined(__APPLE__) \
302 # include <malloc.h> /* for malloc_trim */
305 /* #include <dmalloc.h> */
307 # include <fnmatch.h>
309 #include <sys/utsname.h> /* for setting $HOSTNAME */
311 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
313 #include "shell_common.h"
316 #if ENABLE_HUSH_RANDOM_SUPPORT
319 # define CLEAR_RANDOM_T(rnd) ((void)0)
321 #ifndef F_DUPFD_CLOEXEC
322 # define F_DUPFD_CLOEXEC F_DUPFD
325 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
329 /* So far, all bash compat is controlled by one config option */
330 /* Separate defines document which part of code implements what */
331 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
332 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
333 #define BASH_TEST2 ENABLE_HUSH_BASH_COMPAT
334 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
335 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
339 #define LEAK_HUNTING 0
340 #define BUILD_AS_NOMMU 0
341 /* Enable/disable sanity checks. Ok to enable in production,
342 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
343 * Keeping 1 for now even in released versions.
346 /* Slightly bigger (+200 bytes), but faster hush.
347 * So far it only enables a trick with counting SIGCHLDs and forks,
348 * which allows us to do fewer waitpid's.
349 * (we can detect a case where neither forks were done nor SIGCHLDs happened
350 * and therefore waitpid will return the same result as last time)
352 #define ENABLE_HUSH_FAST 0
353 /* TODO: implement simplified code for users which do not need ${var%...} ops
354 * So far ${var%...} ops are always enabled:
356 #define ENABLE_HUSH_DOLLAR_OPS 1
361 # undef USE_FOR_NOMMU
364 # define USE_FOR_NOMMU(...) __VA_ARGS__
365 # define USE_FOR_MMU(...)
368 #include "NUM_APPLETS.h"
370 /* STANDALONE does not make sense, and won't compile */
371 # undef CONFIG_FEATURE_SH_STANDALONE
372 # undef ENABLE_FEATURE_SH_STANDALONE
373 # undef IF_FEATURE_SH_STANDALONE
374 # undef IF_NOT_FEATURE_SH_STANDALONE
375 # define ENABLE_FEATURE_SH_STANDALONE 0
376 # define IF_FEATURE_SH_STANDALONE(...)
377 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
380 #if !ENABLE_HUSH_INTERACTIVE
381 # undef ENABLE_FEATURE_EDITING
382 # define ENABLE_FEATURE_EDITING 0
383 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
384 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
385 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
386 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
389 /* Do we support ANY keywords? */
390 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
391 # define HAS_KEYWORDS 1
392 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
393 # define IF_HAS_NO_KEYWORDS(...)
395 # define HAS_KEYWORDS 0
396 # define IF_HAS_KEYWORDS(...)
397 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
400 /* If you comment out one of these below, it will be #defined later
401 * to perform debug printfs to stderr: */
402 #define debug_printf(...) do {} while (0)
403 /* Finer-grained debug switches */
404 #define debug_printf_parse(...) do {} while (0)
405 #define debug_print_tree(a, b) do {} while (0)
406 #define debug_printf_exec(...) do {} while (0)
407 #define debug_printf_env(...) do {} while (0)
408 #define debug_printf_jobs(...) do {} while (0)
409 #define debug_printf_expand(...) do {} while (0)
410 #define debug_printf_varexp(...) do {} while (0)
411 #define debug_printf_glob(...) do {} while (0)
412 #define debug_printf_list(...) do {} while (0)
413 #define debug_printf_subst(...) do {} while (0)
414 #define debug_printf_clean(...) do {} while (0)
416 #define ERR_PTR ((void*)(long)1)
418 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
420 #define _SPECIAL_VARS_STR "_*@$!?#"
421 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
422 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
423 #if BASH_PATTERN_SUBST
424 /* Support / and // replace ops */
425 /* Note that // is stored as \ in "encoded" string representation */
426 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
427 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
428 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
430 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
431 # define VAR_SUBST_OPS "%#:-=+?"
432 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
435 #define SPECIAL_VAR_SYMBOL 3
439 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
441 /* This supports saving pointers malloced in vfork child,
442 * to be freed in the parent.
445 typedef struct nommu_save_t {
447 struct variable *old_vars;
449 char **argv_from_re_execing;
462 #if ENABLE_HUSH_LOOPS
469 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
474 /* three pseudo-keywords support contrived "case" syntax: */
475 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
476 RES_MATCH , /* "word)" */
477 RES_CASE_BODY, /* "this command is inside CASE" */
484 typedef struct o_string {
486 int length; /* position where data is appended */
489 /* At least some part of the string was inside '' or "",
490 * possibly empty one: word"", wo''rd etc. */
491 smallint has_quoted_part;
492 smallint has_empty_slot;
493 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
496 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
498 /* Protect newly added chars against globbing
499 * by prepending \ to *, ?, [, \ */
500 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
503 MAYBE_ASSIGNMENT = 0,
504 DEFINITELY_ASSIGNMENT = 1,
506 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
509 /* Used for initialization: o_string foo = NULL_O_STRING; */
510 #define NULL_O_STRING { NULL }
512 #ifndef debug_printf_parse
513 static const char *const assignment_flag[] = {
515 "DEFINITELY_ASSIGNMENT",
521 typedef struct in_str {
523 #if ENABLE_HUSH_INTERACTIVE
524 smallint promptmode; /* 0: PS1, 1: PS2 */
531 /* The descrip member of this structure is only used to make
532 * debugging output pretty */
533 static const struct {
535 signed char default_fd;
538 { O_RDONLY, 0, "<" },
539 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
540 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
541 { O_CREAT|O_RDWR, 1, "<>" },
542 { O_RDONLY, 0, "<<" },
543 /* Should not be needed. Bogus default_fd helps in debugging */
544 /* { O_RDONLY, 77, "<<" }, */
547 struct redir_struct {
548 struct redir_struct *next;
549 char *rd_filename; /* filename */
550 int rd_fd; /* fd to redirect */
551 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
553 smallint rd_type; /* (enum redir_type) */
554 /* note: for heredocs, rd_filename contains heredoc delimiter,
555 * and subsequently heredoc itself; and rd_dup is a bitmask:
556 * bit 0: do we need to trim leading tabs?
557 * bit 1: is heredoc quoted (<<'delim' syntax) ?
560 typedef enum redir_type {
562 REDIRECT_OVERWRITE = 1,
565 REDIRECT_HEREDOC = 4,
566 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
569 REDIRFD_SYNTAX_ERR = -2,
570 REDIRFD_TO_FILE = -1,
571 /* otherwise, rd_fd is redirected to rd_dup */
573 HEREDOC_SKIPTABS = 1,
579 pid_t pid; /* 0 if exited */
580 int assignment_cnt; /* how many argv[i] are assignments? */
581 smallint cmd_type; /* CMD_xxx */
583 #define CMD_SUBSHELL 1
585 /* used for "[[ EXPR ]]" */
586 # define CMD_SINGLEWORD_NOGLOB 2
588 #if ENABLE_HUSH_FUNCTIONS
589 # define CMD_FUNCDEF 3
592 smalluint cmd_exitcode;
593 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
596 char *group_as_string;
598 #if ENABLE_HUSH_FUNCTIONS
599 struct function *child_func;
600 /* This field is used to prevent a bug here:
601 * while...do f1() {a;}; f1; f1() {b;}; f1; done
602 * When we execute "f1() {a;}" cmd, we create new function and clear
603 * cmd->group, cmd->group_as_string, cmd->argv[0].
604 * When we execute "f1() {b;}", we notice that f1 exists,
605 * and that its "parent cmd" struct is still "alive",
606 * we put those fields back into cmd->xxx
607 * (struct function has ->parent_cmd ptr to facilitate that).
608 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
609 * Without this trick, loop would execute a;b;b;b;...
610 * instead of correct sequence a;b;a;b;...
611 * When command is freed, it severs the link
612 * (sets ->child_func->parent_cmd to NULL).
615 char **argv; /* command name and arguments */
616 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
617 * and on execution these are substituted with their values.
618 * Substitution can make _several_ words out of one argv[n]!
619 * Example: argv[0]=='.^C*^C.' here: echo .$*.
620 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
622 struct redir_struct *redirects; /* I/O redirections */
624 /* Is there anything in this command at all? */
625 #define IS_NULL_CMD(cmd) \
626 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
630 int num_cmds; /* total number of commands in pipe */
631 int alive_cmds; /* number of commands running (not exited) */
632 int stopped_cmds; /* number of commands alive, but stopped */
634 unsigned jobid; /* job number */
635 pid_t pgrp; /* process group ID for the job */
636 char *cmdtext; /* name of job */
638 struct command *cmds; /* array of commands in pipe */
639 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
640 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
641 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
643 typedef enum pipe_style {
649 /* Is there anything in this pipe at all? */
650 #define IS_NULL_PIPE(pi) \
651 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
653 /* This holds pointers to the various results of parsing */
654 struct parse_context {
655 /* linked list of pipes */
656 struct pipe *list_head;
657 /* last pipe (being constructed right now) */
659 /* last command in pipe (being constructed right now) */
660 struct command *command;
661 /* last redirect in command->redirects list */
662 struct redir_struct *pending_redirect;
668 smallint ctx_inverted; /* "! cmd | cmd" */
670 smallint ctx_dsemicolon; /* ";;" seen */
672 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
674 /* group we are enclosed in:
675 * example: "if pipe1; pipe2; then pipe3; fi"
676 * when we see "if" or "then", we malloc and copy current context,
677 * and make ->stack point to it. then we parse pipeN.
678 * when closing "then" / fi" / whatever is found,
679 * we move list_head into ->stack->command->group,
680 * copy ->stack into current context, and delete ->stack.
681 * (parsing of { list } and ( list ) doesn't use this method)
683 struct parse_context *stack;
687 /* On program start, environ points to initial environment.
688 * putenv adds new pointers into it, unsetenv removes them.
689 * Neither of these (de)allocates the strings.
690 * setenv allocates new strings in malloc space and does putenv,
691 * and thus setenv is unusable (leaky) for shell's purposes */
692 #define setenv(...) setenv_is_leaky_dont_use()
694 struct variable *next;
695 char *varstr; /* points to "name=" portion */
696 #if ENABLE_HUSH_LOCAL
697 unsigned func_nest_level;
699 int max_len; /* if > 0, name is part of initial env; else name is malloced */
700 smallint flg_export; /* putenv should be done on this var */
701 smallint flg_read_only;
709 #if ENABLE_HUSH_FUNCTIONS
711 struct function *next;
713 struct command *parent_cmd;
716 char *body_as_string;
722 /* set -/+o OPT support. (TODO: make it optional)
723 * bash supports the following opts:
734 * interactive-comments on
752 static const char o_opt_strings[] ALIGN1 =
755 #if ENABLE_HUSH_MODE_X
762 #if ENABLE_HUSH_MODE_X
770 struct FILE_list *next;
776 /* "Globals" within this file */
777 /* Sorted roughly by size (smaller offsets == smaller code) */
779 /* interactive_fd != 0 means we are an interactive shell.
780 * If we are, then saved_tty_pgrp can also be != 0, meaning
781 * that controlling tty is available. With saved_tty_pgrp == 0,
782 * job control still works, but terminal signals
783 * (^C, ^Z, ^Y, ^\) won't work at all, and background
784 * process groups can only be created with "cmd &".
785 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
786 * to give tty to the foreground process group,
787 * and will take it back when the group is stopped (^Z)
790 #if ENABLE_HUSH_INTERACTIVE
791 /* 'interactive_fd' is a fd# open to ctty, if we have one
792 * _AND_ if we decided to act interactively */
796 # define G_interactive_fd (G.interactive_fd)
798 # define G_interactive_fd 0
800 #if ENABLE_FEATURE_EDITING
801 line_input_t *line_input_state;
806 #if ENABLE_HUSH_RANDOM_SUPPORT
812 pid_t saved_tty_pgrp;
813 struct pipe *job_list;
814 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
816 # define G_saved_tty_pgrp 0
818 char o_opt[NUM_OPT_O];
819 #if ENABLE_HUSH_MODE_X
820 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
824 smallint flag_SIGINT;
825 #if ENABLE_HUSH_LOOPS
826 smallint flag_break_continue;
828 #if ENABLE_HUSH_FUNCTIONS
829 /* 0: outside of a function (or sourced file)
830 * -1: inside of a function, ok to use return builtin
831 * 1: return is invoked, skip all till end of func
833 smallint flag_return_in_progress;
834 # define G_flag_return_in_progress (G.flag_return_in_progress)
836 # define G_flag_return_in_progress 0
838 smallint exiting; /* used to prevent EXIT trap recursion */
839 /* These four support $?, $#, and $1 */
840 smalluint last_exitcode;
842 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
843 smalluint global_args_malloced;
844 # define G_global_args_malloced (G.global_args_malloced)
846 # define G_global_args_malloced 0
848 /* how many non-NULL argv's we have. NB: $# + 1 */
852 char *argv0_for_re_execing;
854 #if ENABLE_HUSH_LOOPS
855 unsigned depth_break_continue;
856 unsigned depth_of_loop;
860 struct variable *top_var;
861 char **expanded_assignments;
862 #if ENABLE_HUSH_FUNCTIONS
863 struct function *top_func;
864 # if ENABLE_HUSH_LOCAL
865 struct variable **shadowed_vars_pp;
866 unsigned func_nest_level;
869 /* Signal and trap handling */
871 unsigned count_SIGCHLD;
872 unsigned handled_SIGCHLD;
873 smallint we_have_children;
875 struct FILE_list *FILE_list;
876 /* Which signals have non-DFL handler (even with no traps set)?
877 * Set at the start to:
878 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
879 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
880 * The rest is cleared right before execv syscalls.
881 * Other than these two times, never modified.
883 unsigned special_sig_mask;
885 unsigned fatal_sig_mask;
886 # define G_fatal_sig_mask (G.fatal_sig_mask)
888 # define G_fatal_sig_mask 0
891 char **traps; /* char *traps[NSIG] */
892 # define G_traps G.traps
894 # define G_traps ((char**)NULL)
896 sigset_t pending_set;
897 #if ENABLE_HUSH_MEMLEAK
898 unsigned long memleak_value;
904 #if ENABLE_FEATURE_EDITING
905 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
908 #define G (*ptr_to_globals)
909 /* Not #defining name to G.name - this quickly gets unwieldy
910 * (too many defines). Also, I actually prefer to see when a variable
911 * is global, thus "G." prefix is a useful hint */
912 #define INIT_G() do { \
913 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
914 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
915 sigfillset(&G.sa.sa_mask); \
916 G.sa.sa_flags = SA_RESTART; \
920 /* Function prototypes for builtins */
921 static int builtin_cd(char **argv) FAST_FUNC;
923 static int builtin_echo(char **argv) FAST_FUNC;
925 static int builtin_eval(char **argv) FAST_FUNC;
926 static int builtin_exec(char **argv) FAST_FUNC;
927 static int builtin_exit(char **argv) FAST_FUNC;
928 #if ENABLE_HUSH_EXPORT
929 static int builtin_export(char **argv) FAST_FUNC;
932 static int builtin_fg_bg(char **argv) FAST_FUNC;
933 static int builtin_jobs(char **argv) FAST_FUNC;
936 static int builtin_help(char **argv) FAST_FUNC;
938 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
939 static int builtin_history(char **argv) FAST_FUNC;
941 #if ENABLE_HUSH_LOCAL
942 static int builtin_local(char **argv) FAST_FUNC;
944 #if ENABLE_HUSH_MEMLEAK
945 static int builtin_memleak(char **argv) FAST_FUNC;
947 #if ENABLE_HUSH_PRINTF
948 static int builtin_printf(char **argv) FAST_FUNC;
950 static int builtin_pwd(char **argv) FAST_FUNC;
952 static int builtin_read(char **argv) FAST_FUNC;
955 static int builtin_set(char **argv) FAST_FUNC;
957 static int builtin_shift(char **argv) FAST_FUNC;
958 static int builtin_source(char **argv) FAST_FUNC;
959 #if ENABLE_HUSH_TEST || BASH_TEST2
960 static int builtin_test(char **argv) FAST_FUNC;
963 static int builtin_trap(char **argv) FAST_FUNC;
966 static int builtin_type(char **argv) FAST_FUNC;
968 static int builtin_true(char **argv) FAST_FUNC;
969 #if ENABLE_HUSH_UMASK
970 static int builtin_umask(char **argv) FAST_FUNC;
972 #if ENABLE_HUSH_UNSET
973 static int builtin_unset(char **argv) FAST_FUNC;
976 static int builtin_kill(char **argv) FAST_FUNC;
979 static int builtin_wait(char **argv) FAST_FUNC;
981 #if ENABLE_HUSH_LOOPS
982 static int builtin_break(char **argv) FAST_FUNC;
983 static int builtin_continue(char **argv) FAST_FUNC;
985 #if ENABLE_HUSH_FUNCTIONS
986 static int builtin_return(char **argv) FAST_FUNC;
989 /* Table of built-in functions. They can be forked or not, depending on
990 * context: within pipes, they fork. As simple commands, they do not.
991 * When used in non-forking context, they can change global variables
992 * in the parent shell process. If forked, of course they cannot.
993 * For example, 'unset foo | whatever' will parse and run, but foo will
994 * still be set at the end. */
995 struct built_in_command {
997 int (*b_function)(char **argv) FAST_FUNC;
1000 # define BLTIN(cmd, func, help) { cmd, func, help }
1002 # define BLTIN(cmd, func, help) { cmd, func }
1006 static const struct built_in_command bltins1[] = {
1007 BLTIN("." , builtin_source , "Run commands in file"),
1008 BLTIN(":" , builtin_true , NULL),
1010 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1012 #if ENABLE_HUSH_LOOPS
1013 BLTIN("break" , builtin_break , "Exit loop"),
1015 BLTIN("cd" , builtin_cd , "Change directory"),
1016 #if ENABLE_HUSH_LOOPS
1017 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1019 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1020 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1021 BLTIN("exit" , builtin_exit , NULL),
1022 #if ENABLE_HUSH_EXPORT
1023 BLTIN("export" , builtin_export , "Set environment variables"),
1026 BLTIN("fg" , builtin_fg_bg , "Bring job into foreground"),
1028 #if ENABLE_HUSH_HELP
1029 BLTIN("help" , builtin_help , NULL),
1031 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1032 BLTIN("history" , builtin_history , "Show history"),
1035 BLTIN("jobs" , builtin_jobs , "List jobs"),
1037 #if ENABLE_HUSH_KILL
1038 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1040 #if ENABLE_HUSH_LOCAL
1041 BLTIN("local" , builtin_local , "Set local variables"),
1043 #if ENABLE_HUSH_MEMLEAK
1044 BLTIN("memleak" , builtin_memleak , NULL),
1046 #if ENABLE_HUSH_READ
1047 BLTIN("read" , builtin_read , "Input into variable"),
1049 #if ENABLE_HUSH_FUNCTIONS
1050 BLTIN("return" , builtin_return , "Return from function"),
1053 BLTIN("set" , builtin_set , "Set positional parameters"),
1055 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1057 BLTIN("source" , builtin_source , NULL),
1059 #if ENABLE_HUSH_TRAP
1060 BLTIN("trap" , builtin_trap , "Trap signals"),
1062 BLTIN("true" , builtin_true , NULL),
1063 #if ENABLE_HUSH_TYPE
1064 BLTIN("type" , builtin_type , "Show command type"),
1066 #if ENABLE_HUSH_ULIMIT
1067 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1069 #if ENABLE_HUSH_UMASK
1070 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1072 #if ENABLE_HUSH_UNSET
1073 BLTIN("unset" , builtin_unset , "Unset variables"),
1075 #if ENABLE_HUSH_WAIT
1076 BLTIN("wait" , builtin_wait , "Wait for process"),
1079 /* These builtins won't be used if we are on NOMMU and need to re-exec
1080 * (it's cheaper to run an external program in this case):
1082 static const struct built_in_command bltins2[] = {
1083 #if ENABLE_HUSH_TEST
1084 BLTIN("[" , builtin_test , NULL),
1086 #if ENABLE_HUSH_ECHO
1087 BLTIN("echo" , builtin_echo , NULL),
1089 #if ENABLE_HUSH_PRINTF
1090 BLTIN("printf" , builtin_printf , NULL),
1092 BLTIN("pwd" , builtin_pwd , NULL),
1093 #if ENABLE_HUSH_TEST
1094 BLTIN("test" , builtin_test , NULL),
1102 /* prevent disasters with G.debug_indent < 0 */
1103 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1104 # define debug_enter() (G.debug_indent++)
1105 # define debug_leave() (G.debug_indent--)
1107 # define indent() ((void)0)
1108 # define debug_enter() ((void)0)
1109 # define debug_leave() ((void)0)
1112 #ifndef debug_printf
1113 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1116 #ifndef debug_printf_parse
1117 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1120 #ifndef debug_printf_exec
1121 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1124 #ifndef debug_printf_env
1125 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1128 #ifndef debug_printf_jobs
1129 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1130 # define DEBUG_JOBS 1
1132 # define DEBUG_JOBS 0
1135 #ifndef debug_printf_expand
1136 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1137 # define DEBUG_EXPAND 1
1139 # define DEBUG_EXPAND 0
1142 #ifndef debug_printf_varexp
1143 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1146 #ifndef debug_printf_glob
1147 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1148 # define DEBUG_GLOB 1
1150 # define DEBUG_GLOB 0
1153 #ifndef debug_printf_list
1154 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1157 #ifndef debug_printf_subst
1158 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1161 #ifndef debug_printf_clean
1162 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1163 # define DEBUG_CLEAN 1
1165 # define DEBUG_CLEAN 0
1169 static void debug_print_strings(const char *prefix, char **vv)
1172 fdprintf(2, "%s:\n", prefix);
1174 fdprintf(2, " '%s'\n", *vv++);
1177 # define debug_print_strings(prefix, vv) ((void)0)
1181 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1184 static void *xxmalloc(int lineno, size_t size)
1186 void *ptr = xmalloc((size + 0xff) & ~0xff);
1187 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1190 static void *xxrealloc(int lineno, void *ptr, size_t size)
1192 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1193 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1196 static char *xxstrdup(int lineno, const char *str)
1198 char *ptr = xstrdup(str);
1199 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1202 static void xxfree(void *ptr)
1204 fdprintf(2, "free %p\n", ptr);
1207 # define xmalloc(s) xxmalloc(__LINE__, s)
1208 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1209 # define xstrdup(s) xxstrdup(__LINE__, s)
1210 # define free(p) xxfree(p)
1214 /* Syntax and runtime errors. They always abort scripts.
1215 * In interactive use they usually discard unparsed and/or unexecuted commands
1216 * and return to the prompt.
1217 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1220 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1221 # define syntax_error(lineno, msg) syntax_error(msg)
1222 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1223 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1224 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1225 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1228 static void die_if_script(unsigned lineno, const char *fmt, ...)
1233 bb_error_msg("hush.c:%u", lineno);
1236 bb_verror_msg(fmt, p, NULL);
1238 if (!G_interactive_fd)
1242 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1245 bb_error_msg("syntax error: %s", msg);
1247 bb_error_msg("syntax error");
1250 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1252 bb_error_msg("syntax error at '%s'", msg);
1255 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1257 bb_error_msg("syntax error: unterminated %s", s);
1260 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1262 char msg[2] = { ch, '\0' };
1263 syntax_error_unterm_str(lineno, msg);
1266 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1272 bb_error_msg("hush.c:%u", lineno);
1274 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1278 # undef die_if_script
1279 # undef syntax_error
1280 # undef syntax_error_at
1281 # undef syntax_error_unterm_ch
1282 # undef syntax_error_unterm_str
1283 # undef syntax_error_unexpected_ch
1285 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1286 # define syntax_error(msg) syntax_error(__LINE__, msg)
1287 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1288 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1289 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1290 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1294 #if ENABLE_HUSH_INTERACTIVE
1295 static void cmdedit_update_prompt(void);
1297 # define cmdedit_update_prompt() ((void)0)
1301 /* Utility functions
1303 /* Replace each \x with x in place, return ptr past NUL. */
1304 static char *unbackslash(char *src)
1306 char *dst = src = strchrnul(src, '\\');
1310 if ((*dst++ = *src++) == '\0')
1316 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1337 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1338 v[count1 + count2] = NULL;
1341 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1345 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1347 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1348 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1351 #define add_strings_to_strings(strings, add, need_to_dup) \
1352 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1355 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1356 static char **add_string_to_strings(char **strings, char *add)
1361 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1364 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1366 char **ptr = add_string_to_strings(strings, add);
1367 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1370 #define add_string_to_strings(strings, add) \
1371 xx_add_string_to_strings(__LINE__, strings, add)
1374 static void free_strings(char **strings)
1389 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1391 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1392 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1394 /* fd was not open? */
1404 /* Manipulating the list of open FILEs */
1405 static FILE *remember_FILE(FILE *fp)
1408 struct FILE_list *n = xmalloc(sizeof(*n));
1409 n->next = G.FILE_list;
1413 close_on_exec_on(n->fd);
1417 static void fclose_and_forget(FILE *fp)
1419 struct FILE_list **pp = &G.FILE_list;
1421 struct FILE_list *cur = *pp;
1422 if (cur->fp == fp) {
1431 static int save_FILEs_on_redirect(int fd)
1433 struct FILE_list *fl = G.FILE_list;
1436 /* We use it only on script files, they are all CLOEXEC */
1437 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1444 static void restore_redirected_FILEs(void)
1446 struct FILE_list *fl = G.FILE_list;
1448 int should_be = fileno(fl->fp);
1449 if (fl->fd != should_be) {
1450 xmove_fd(fl->fd, should_be);
1456 #if ENABLE_FEATURE_SH_STANDALONE
1457 static void close_all_FILE_list(void)
1459 struct FILE_list *fl = G.FILE_list;
1461 /* fclose would also free FILE object.
1462 * It is disastrous if we share memory with a vforked parent.
1463 * I'm not sure we never come here after vfork.
1464 * Therefore just close fd, nothing more.
1466 /*fclose(fl->fp); - unsafe */
1474 /* Helpers for setting new $n and restoring them back
1476 typedef struct save_arg_t {
1480 IF_HUSH_SET(smallint sv_g_malloced;)
1483 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1487 sv->sv_argv0 = argv[0];
1488 sv->sv_g_argv = G.global_argv;
1489 sv->sv_g_argc = G.global_argc;
1490 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1492 argv[0] = G.global_argv[0]; /* retain $0 */
1493 G.global_argv = argv;
1494 IF_HUSH_SET(G.global_args_malloced = 0;)
1502 static void restore_G_args(save_arg_t *sv, char **argv)
1505 if (G.global_args_malloced) {
1506 /* someone ran "set -- arg1 arg2 ...", undo */
1507 char **pp = G.global_argv;
1508 while (*++pp) /* note: does not free $0 */
1510 free(G.global_argv);
1513 argv[0] = sv->sv_argv0;
1514 G.global_argv = sv->sv_g_argv;
1515 G.global_argc = sv->sv_g_argc;
1516 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1520 /* Basic theory of signal handling in shell
1521 * ========================================
1522 * This does not describe what hush does, rather, it is current understanding
1523 * what it _should_ do. If it doesn't, it's a bug.
1524 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1526 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1527 * is finished or backgrounded. It is the same in interactive and
1528 * non-interactive shells, and is the same regardless of whether
1529 * a user trap handler is installed or a shell special one is in effect.
1530 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1531 * backgrounds (i.e. stops) or kills all members of currently running
1534 * Wait builtin is interruptible by signals for which user trap is set
1535 * or by SIGINT in interactive shell.
1537 * Trap handlers will execute even within trap handlers. (right?)
1539 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1540 * except for handlers set to '' (empty string).
1542 * If job control is off, backgrounded commands ("cmd &")
1543 * have SIGINT, SIGQUIT set to SIG_IGN.
1545 * Commands which are run in command substitution ("`cmd`")
1546 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1548 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1549 * by the shell from its parent.
1551 * Signals which differ from SIG_DFL action
1552 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1555 * SIGTERM (interactive): ignore
1556 * SIGHUP (interactive):
1557 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1558 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1559 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1560 * that all pipe members are stopped. Try this in bash:
1561 * while :; do :; done - ^Z does not background it
1562 * (while :; do :; done) - ^Z backgrounds it
1563 * SIGINT (interactive): wait for last pipe, ignore the rest
1564 * of the command line, show prompt. NB: ^C does not send SIGINT
1565 * to interactive shell while shell is waiting for a pipe,
1566 * since shell is bg'ed (is not in foreground process group).
1567 * Example 1: this waits 5 sec, but does not execute ls:
1568 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1569 * Example 2: this does not wait and does not execute ls:
1570 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1571 * Example 3: this does not wait 5 sec, but executes ls:
1572 * "sleep 5; ls -l" + press ^C
1573 * Example 4: this does not wait and does not execute ls:
1574 * "sleep 5 & wait; ls -l" + press ^C
1576 * (What happens to signals which are IGN on shell start?)
1577 * (What happens with signal mask on shell start?)
1579 * Old implementation
1580 * ==================
1581 * We use in-kernel pending signal mask to determine which signals were sent.
1582 * We block all signals which we don't want to take action immediately,
1583 * i.e. we block all signals which need to have special handling as described
1584 * above, and all signals which have traps set.
1585 * After each pipe execution, we extract any pending signals via sigtimedwait()
1588 * unsigned special_sig_mask: a mask of such "special" signals
1589 * sigset_t blocked_set: current blocked signal set
1592 * clear bit in blocked_set unless it is also in special_sig_mask
1593 * "trap 'cmd' SIGxxx":
1594 * set bit in blocked_set (even if 'cmd' is '')
1595 * after [v]fork, if we plan to be a shell:
1596 * unblock signals with special interactive handling
1597 * (child shell is not interactive),
1598 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1599 * after [v]fork, if we plan to exec:
1600 * POSIX says fork clears pending signal mask in child - no need to clear it.
1601 * Restore blocked signal set to one inherited by shell just prior to exec.
1603 * Note: as a result, we do not use signal handlers much. The only uses
1604 * are to count SIGCHLDs
1605 * and to restore tty pgrp on signal-induced exit.
1608 * Standard says "When a subshell is entered, traps that are not being ignored
1609 * are set to the default actions". bash interprets it so that traps which
1610 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1612 * Problem: the above approach makes it unwieldy to catch signals while
1613 * we are in read builtin, or while we read commands from stdin:
1614 * masked signals are not visible!
1616 * New implementation
1617 * ==================
1618 * We record each signal we are interested in by installing signal handler
1619 * for them - a bit like emulating kernel pending signal mask in userspace.
1620 * We are interested in: signals which need to have special handling
1621 * as described above, and all signals which have traps set.
1622 * Signals are recorded in pending_set.
1623 * After each pipe execution, we extract any pending signals
1626 * unsigned special_sig_mask: a mask of shell-special signals.
1627 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1628 * char *traps[sig] if trap for sig is set (even if it's '').
1629 * sigset_t pending_set: set of sigs we received.
1632 * if sig is in special_sig_mask, set handler back to:
1633 * record_pending_signo, or to IGN if it's a tty stop signal
1634 * if sig is in fatal_sig_mask, set handler back to sigexit.
1635 * else: set handler back to SIG_DFL
1636 * "trap 'cmd' SIGxxx":
1637 * set handler to record_pending_signo.
1639 * set handler to SIG_IGN.
1640 * after [v]fork, if we plan to be a shell:
1641 * set signals with special interactive handling to SIG_DFL
1642 * (because child shell is not interactive),
1643 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1644 * after [v]fork, if we plan to exec:
1645 * POSIX says fork clears pending signal mask in child - no need to clear it.
1647 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1648 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1651 * Standard says "When a subshell is entered, traps that are not being ignored
1652 * are set to the default actions". bash interprets it so that traps which
1653 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1656 SPECIAL_INTERACTIVE_SIGS = 0
1661 SPECIAL_JOBSTOP_SIGS = 0
1670 static void record_pending_signo(int sig)
1672 sigaddset(&G.pending_set, sig);
1673 #if ENABLE_HUSH_FAST
1674 if (sig == SIGCHLD) {
1676 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1681 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1683 struct sigaction old_sa;
1685 /* We could use signal() to install handlers... almost:
1686 * except that we need to mask ALL signals while handlers run.
1687 * I saw signal nesting in strace, race window isn't small.
1688 * SA_RESTART is also needed, but in Linux, signal()
1689 * sets SA_RESTART too.
1691 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1692 /* sigfillset(&G.sa.sa_mask); - already done */
1693 /* G.sa.sa_flags = SA_RESTART; - already done */
1694 G.sa.sa_handler = handler;
1695 sigaction(sig, &G.sa, &old_sa);
1696 return old_sa.sa_handler;
1699 static void hush_exit(int exitcode) NORETURN;
1701 static void restore_ttypgrp_and__exit(void) NORETURN;
1702 static void restore_ttypgrp_and__exit(void)
1704 /* xfunc has failed! die die die */
1705 /* no EXIT traps, this is an escape hatch! */
1707 hush_exit(xfunc_error_retval);
1712 /* Needed only on some libc:
1713 * It was observed that on exit(), fgetc'ed buffered data
1714 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1715 * With the net effect that even after fork(), not vfork(),
1716 * exit() in NOEXECed applet in "sh SCRIPT":
1717 * noexec_applet_here
1718 * echo END_OF_SCRIPT
1719 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1720 * This makes "echo END_OF_SCRIPT" executed twice.
1721 * Similar problems can be seen with die_if_script() -> xfunc_die()
1722 * and in `cmd` handling.
1723 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1725 static void fflush_and__exit(void) NORETURN;
1726 static void fflush_and__exit(void)
1729 _exit(xfunc_error_retval);
1732 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1733 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1734 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1735 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1737 /* Restores tty foreground process group, and exits.
1738 * May be called as signal handler for fatal signal
1739 * (will resend signal to itself, producing correct exit state)
1740 * or called directly with -EXITCODE.
1741 * We also call it if xfunc is exiting.
1743 static void sigexit(int sig) NORETURN;
1744 static void sigexit(int sig)
1746 /* Careful: we can end up here after [v]fork. Do not restore
1747 * tty pgrp then, only top-level shell process does that */
1748 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1749 /* Disable all signals: job control, SIGPIPE, etc.
1750 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1752 sigprocmask_allsigs(SIG_BLOCK);
1753 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1756 /* Not a signal, just exit */
1760 kill_myself_with_sig(sig); /* does not return */
1764 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1765 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1769 static sighandler_t pick_sighandler(unsigned sig)
1771 sighandler_t handler = SIG_DFL;
1772 if (sig < sizeof(unsigned)*8) {
1773 unsigned sigmask = (1 << sig);
1777 if (G_fatal_sig_mask & sigmask)
1781 /* sig has special handling? */
1782 if (G.special_sig_mask & sigmask) {
1783 handler = record_pending_signo;
1784 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1785 * in order to ignore them: they will be raised
1786 * in an endless loop when we try to do some
1787 * terminal ioctls! We do have to _ignore_ these.
1789 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1796 /* Restores tty foreground process group, and exits. */
1797 static void hush_exit(int exitcode)
1799 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1800 save_history(G.line_input_state);
1804 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1806 /* argv[0] is unused */
1807 argv[1] = G_traps[0];
1809 G.exiting = 1; /* prevent EXIT trap recursion */
1810 /* Note: G_traps[0] is not cleared!
1811 * "trap" will still show it, if executed
1816 #if ENABLE_FEATURE_CLEAN_UP
1818 struct variable *cur_var;
1819 if (G.cwd != bb_msg_unknown)
1821 cur_var = G.top_var;
1823 struct variable *tmp = cur_var;
1824 if (!cur_var->max_len)
1825 free(cur_var->varstr);
1826 cur_var = cur_var->next;
1834 sigexit(- (exitcode & 0xff));
1841 //TODO: return a mask of ALL handled sigs?
1842 static int check_and_run_traps(void)
1849 if (sigisemptyset(&G.pending_set))
1854 if (sigismember(&G.pending_set, sig)) {
1855 sigdelset(&G.pending_set, sig);
1858 } while (sig < NSIG);
1861 if (G_traps && G_traps[sig]) {
1862 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1863 if (G_traps[sig][0]) {
1864 /* We have user-defined handler */
1865 smalluint save_rcode;
1867 /* argv[0] is unused */
1868 argv[1] = G_traps[sig];
1870 save_rcode = G.last_exitcode;
1872 //FIXME: shouldn't it be set to 128 + sig instead?
1873 G.last_exitcode = save_rcode;
1875 } /* else: "" trap, ignoring signal */
1878 /* not a trap: special action */
1881 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1888 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1889 /* bash is observed to signal whole process groups,
1890 * not individual processes */
1891 for (job = G.job_list; job; job = job->next) {
1894 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1895 if (kill(- job->pgrp, SIGHUP) == 0)
1896 kill(- job->pgrp, SIGCONT);
1901 #if ENABLE_HUSH_FAST
1903 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1905 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1907 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1908 * This simplifies wait builtin a bit.
1912 default: /* ignored: */
1913 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1914 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1916 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1917 * Example: wait is not interrupted by TERM
1918 * in interactive shell, because TERM is ignored.
1927 static const char *get_cwd(int force)
1929 if (force || G.cwd == NULL) {
1930 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1931 * we must not try to free(bb_msg_unknown) */
1932 if (G.cwd == bb_msg_unknown)
1934 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1936 G.cwd = bb_msg_unknown;
1943 * Shell and environment variable support
1945 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1947 struct variable **pp;
1948 struct variable *cur;
1951 while ((cur = *pp) != NULL) {
1952 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1959 static const char* FAST_FUNC get_local_var_value(const char *name)
1961 struct variable **vpp;
1962 unsigned len = strlen(name);
1964 if (G.expanded_assignments) {
1965 char **cpp = G.expanded_assignments;
1968 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1969 return cp + len + 1;
1974 vpp = get_ptr_to_local_var(name, len);
1976 return (*vpp)->varstr + len + 1;
1978 if (strcmp(name, "PPID") == 0)
1979 return utoa(G.root_ppid);
1980 // bash compat: UID? EUID?
1981 #if ENABLE_HUSH_RANDOM_SUPPORT
1982 if (strcmp(name, "RANDOM") == 0)
1983 return utoa(next_random(&G.random_gen));
1988 /* str holds "NAME=VAL" and is expected to be malloced.
1989 * We take ownership of it.
1991 * 0: do not change export flag
1992 * (if creating new variable, flag will be 0)
1993 * 1: set export flag and putenv the variable
1994 * -1: clear export flag and unsetenv the variable
1995 * flg_read_only is set only when we handle -R var=val
1997 #if !BB_MMU && ENABLE_HUSH_LOCAL
1998 /* all params are used */
1999 #elif BB_MMU && ENABLE_HUSH_LOCAL
2000 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2001 set_local_var(str, flg_export, local_lvl)
2002 #elif BB_MMU && !ENABLE_HUSH_LOCAL
2003 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2004 set_local_var(str, flg_export)
2005 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
2006 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
2007 set_local_var(str, flg_export, flg_read_only)
2009 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
2011 struct variable **var_pp;
2012 struct variable *cur;
2013 char *free_me = NULL;
2017 eq_sign = strchr(str, '=');
2018 if (!eq_sign) { /* not expected to ever happen? */
2023 name_len = eq_sign - str + 1; /* including '=' */
2024 var_pp = &G.top_var;
2025 while ((cur = *var_pp) != NULL) {
2026 if (strncmp(cur->varstr, str, name_len) != 0) {
2027 var_pp = &cur->next;
2031 /* We found an existing var with this name */
2032 if (cur->flg_read_only) {
2036 bb_error_msg("%s: readonly variable", str);
2040 if (flg_export == -1) { // "&& cur->flg_export" ?
2041 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2046 #if ENABLE_HUSH_LOCAL
2047 if (cur->func_nest_level < local_lvl) {
2048 /* New variable is declared as local,
2049 * and existing one is global, or local
2050 * from enclosing function.
2051 * Remove and save old one: */
2052 *var_pp = cur->next;
2053 cur->next = *G.shadowed_vars_pp;
2054 *G.shadowed_vars_pp = cur;
2055 /* bash 3.2.33(1) and exported vars:
2057 * # f() { local z=a; env | grep ^z; }
2063 if (cur->flg_export)
2068 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2073 if (cur->max_len != 0) {
2074 if (cur->max_len >= strlen(str)) {
2075 /* This one is from startup env, reuse space */
2076 strcpy(cur->varstr, str);
2081 goto set_str_and_exp;
2083 /* max_len == 0 signifies "malloced" var, which we can
2084 * (and have to) free. But we can't free(cur->varstr) here:
2085 * if cur->flg_export is 1, it is in the environment.
2086 * We should either unsetenv+free, or wait until putenv,
2087 * then putenv(new)+free(old).
2089 free_me = cur->varstr;
2090 goto set_str_and_exp;
2093 /* Not found - create new variable struct */
2094 cur = xzalloc(sizeof(*cur));
2095 #if ENABLE_HUSH_LOCAL
2096 cur->func_nest_level = local_lvl;
2098 cur->next = *var_pp;
2104 cur->flg_read_only = flg_read_only;
2107 if (flg_export == 1)
2108 cur->flg_export = 1;
2109 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2110 cmdedit_update_prompt();
2111 if (cur->flg_export) {
2112 if (flg_export == -1) {
2113 cur->flg_export = 0;
2114 /* unsetenv was already done */
2117 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2118 i = putenv(cur->varstr);
2119 /* only now we can free old exported malloced string */
2128 /* Used at startup and after each cd */
2129 static void set_pwd_var(int exp)
2131 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
2132 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2135 static int unset_local_var_len(const char *name, int name_len)
2137 struct variable *cur;
2138 struct variable **var_pp;
2141 return EXIT_SUCCESS;
2142 var_pp = &G.top_var;
2143 while ((cur = *var_pp) != NULL) {
2144 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2145 if (cur->flg_read_only) {
2146 bb_error_msg("%s: readonly variable", name);
2147 return EXIT_FAILURE;
2149 *var_pp = cur->next;
2150 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2151 bb_unsetenv(cur->varstr);
2152 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2153 cmdedit_update_prompt();
2157 return EXIT_SUCCESS;
2159 var_pp = &cur->next;
2161 return EXIT_SUCCESS;
2164 #if ENABLE_HUSH_UNSET
2165 static int unset_local_var(const char *name)
2167 return unset_local_var_len(name, strlen(name));
2171 static void unset_vars(char **strings)
2179 const char *eq = strchrnul(*v, '=');
2180 unset_local_var_len(*v, (int)(eq - *v));
2186 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2187 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2189 char *var = xasprintf("%s=%s", name, val);
2190 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2196 * Helpers for "var1=val1 var2=val2 cmd" feature
2198 static void add_vars(struct variable *var)
2200 struct variable *next;
2204 var->next = G.top_var;
2206 if (var->flg_export) {
2207 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2208 putenv(var->varstr);
2210 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2216 static struct variable *set_vars_and_save_old(char **strings)
2219 struct variable *old = NULL;
2225 struct variable *var_p;
2226 struct variable **var_pp;
2229 eq = strchr(*s, '=');
2231 var_pp = get_ptr_to_local_var(*s, eq - *s);
2233 /* Remove variable from global linked list */
2235 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2236 *var_pp = var_p->next;
2237 /* Add it to returned list */
2241 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2252 static void reinit_unicode_for_hush(void)
2254 /* Unicode support should be activated even if LANG is set
2255 * _during_ shell execution, not only if it was set when
2256 * shell was started. Therefore, re-check LANG every time:
2258 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2259 || ENABLE_UNICODE_USING_LOCALE
2261 const char *s = get_local_var_value("LC_ALL");
2262 if (!s) s = get_local_var_value("LC_CTYPE");
2263 if (!s) s = get_local_var_value("LANG");
2269 * in_str support (strings, and "strings" read from files).
2272 #if ENABLE_HUSH_INTERACTIVE
2273 /* To test correct lineedit/interactive behavior, type from command line:
2279 * It excercises a lot of corner cases.
2281 static void cmdedit_update_prompt(void)
2283 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2284 G.PS1 = get_local_var_value("PS1");
2287 G.PS2 = get_local_var_value("PS2");
2294 static const char *setup_prompt_string(int promptmode)
2296 const char *prompt_str;
2297 debug_printf("setup_prompt_string %d ", promptmode);
2298 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2299 /* Set up the prompt */
2300 if (promptmode == 0) { /* PS1 */
2302 /* bash uses $PWD value, even if it is set by user.
2303 * It uses current dir only if PWD is unset.
2304 * We always use current dir. */
2305 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2310 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2311 debug_printf("prompt_str '%s'\n", prompt_str);
2314 static int get_user_input(struct in_str *i)
2317 const char *prompt_str;
2319 prompt_str = setup_prompt_string(i->promptmode);
2320 # if ENABLE_FEATURE_EDITING
2322 reinit_unicode_for_hush();
2323 if (G.flag_SIGINT) {
2324 /* There was ^C'ed, make it look prettier: */
2328 /* buglet: SIGINT will not make new prompt to appear _at once_,
2329 * only after <Enter>. (^C works immediately) */
2330 r = read_line_input(G.line_input_state, prompt_str,
2331 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2334 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2336 write(STDOUT_FILENO, "^C", 2);
2339 check_and_run_traps();
2340 if (r != 0 && !G.flag_SIGINT)
2342 /* ^C or SIGINT: repeat */
2343 G.last_exitcode = 128 + SIGINT;
2346 /* EOF/error detected */
2348 i->peek_buf[0] = r = EOF;
2351 i->p = G.user_input_buf;
2352 return (unsigned char)*i->p++;
2356 if (i->last_char == '\0' || i->last_char == '\n') {
2357 /* Why check_and_run_traps here? Try this interactively:
2358 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2359 * $ <[enter], repeatedly...>
2360 * Without check_and_run_traps, handler never runs.
2362 check_and_run_traps();
2363 fputs(prompt_str, stdout);
2366 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2368 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2369 * no ^C masking happens during fgetc, no special code for ^C:
2370 * it generates SIGINT as usual.
2372 check_and_run_traps();
2374 G.last_exitcode = 128 + SIGINT;
2381 /* This is the magic location that prints prompts
2382 * and gets data back from the user */
2383 static int fgetc_interactive(struct in_str *i)
2386 /* If it's interactive stdin, get new line. */
2387 if (G_interactive_fd && i->file == stdin) {
2388 /* Returns first char (or EOF), the rest is in i->p[] */
2389 ch = get_user_input(i);
2390 i->promptmode = 1; /* PS2 */
2392 /* Not stdin: script file, sourced file, etc */
2393 do ch = fgetc(i->file); while (ch == '\0');
2398 static inline int fgetc_interactive(struct in_str *i)
2401 do ch = fgetc(i->file); while (ch == '\0');
2404 #endif /* INTERACTIVE */
2406 static int i_getch(struct in_str *i)
2411 /* string-based in_str */
2412 ch = (unsigned char)*i->p;
2421 /* FILE-based in_str */
2423 #if ENABLE_FEATURE_EDITING
2424 /* This can be stdin, check line editing char[] buffer */
2425 if (i->p && *i->p != '\0') {
2426 ch = (unsigned char)*i->p++;
2430 /* peek_buf[] is an int array, not char. Can contain EOF. */
2431 ch = i->peek_buf[0];
2433 int ch2 = i->peek_buf[1];
2434 i->peek_buf[0] = ch2;
2435 if (ch2 == 0) /* very likely, avoid redundant write */
2441 ch = fgetc_interactive(i);
2443 debug_printf("file_get: got '%c' %d\n", ch, ch);
2448 static int i_peek(struct in_str *i)
2453 /* string-based in_str */
2454 /* Doesn't report EOF on NUL. None of the callers care. */
2455 return (unsigned char)*i->p;
2458 /* FILE-based in_str */
2460 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2461 /* This can be stdin, check line editing char[] buffer */
2462 if (i->p && *i->p != '\0')
2463 return (unsigned char)*i->p;
2465 /* peek_buf[] is an int array, not char. Can contain EOF. */
2466 ch = i->peek_buf[0];
2470 /* Need to get a new char */
2471 ch = fgetc_interactive(i);
2472 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2474 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2475 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2481 i->peek_buf[0] = ch;
2482 /*i->peek_buf[1] = 0; - already is */
2486 /* Only ever called if i_peek() was called, and did not return EOF.
2487 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2488 * not end-of-line. Therefore we never need to read a new editing line here.
2490 static int i_peek2(struct in_str *i)
2494 /* There are two cases when i->p[] buffer exists.
2495 * (1) it's a string in_str.
2496 * (2) It's a file, and we have a saved line editing buffer.
2497 * In both cases, we know that i->p[0] exists and not NUL, and
2498 * the peek2 result is in i->p[1].
2501 return (unsigned char)i->p[1];
2503 /* Now we know it is a file-based in_str. */
2505 /* peek_buf[] is an int array, not char. Can contain EOF. */
2506 /* Is there 2nd char? */
2507 ch = i->peek_buf[1];
2509 /* We did not read it yet, get it now */
2510 do ch = fgetc(i->file); while (ch == '\0');
2511 i->peek_buf[1] = ch;
2514 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2518 static void setup_file_in_str(struct in_str *i, FILE *f)
2520 memset(i, 0, sizeof(*i));
2521 /* i->promptmode = 0; - PS1 (memset did it) */
2526 static void setup_string_in_str(struct in_str *i, const char *s)
2528 memset(i, 0, sizeof(*i));
2529 /* i->promptmode = 0; - PS1 (memset did it) */
2530 /*i->file = NULL */;
2538 #define B_CHUNK (32 * sizeof(char*))
2540 static void o_reset_to_empty_unquoted(o_string *o)
2543 o->has_quoted_part = 0;
2548 static void o_free(o_string *o)
2551 memset(o, 0, sizeof(*o));
2554 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2559 static void o_grow_by(o_string *o, int len)
2561 if (o->length + len > o->maxlen) {
2562 o->maxlen += (2 * len) | (B_CHUNK-1);
2563 o->data = xrealloc(o->data, 1 + o->maxlen);
2567 static void o_addchr(o_string *o, int ch)
2569 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2570 if (o->length < o->maxlen) {
2571 /* likely. avoid o_grow_by() call */
2573 o->data[o->length] = ch;
2575 o->data[o->length] = '\0';
2583 /* Valid only if we know o_string is not empty */
2584 static void o_delchr(o_string *o)
2587 o->data[o->length] = '\0';
2591 static void o_addblock(o_string *o, const char *str, int len)
2594 memcpy(&o->data[o->length], str, len);
2596 o->data[o->length] = '\0';
2599 static void o_addstr(o_string *o, const char *str)
2601 o_addblock(o, str, strlen(str));
2605 static void nommu_addchr(o_string *o, int ch)
2611 # define nommu_addchr(o, str) ((void)0)
2614 static void o_addstr_with_NUL(o_string *o, const char *str)
2616 o_addblock(o, str, strlen(str) + 1);
2620 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2621 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2622 * Apparently, on unquoted $v bash still does globbing
2623 * ("v='*.txt'; echo $v" prints all .txt files),
2624 * but NOT brace expansion! Thus, there should be TWO independent
2625 * quoting mechanisms on $v expansion side: one protects
2626 * $v from brace expansion, and other additionally protects "$v" against globbing.
2627 * We have only second one.
2630 #if ENABLE_HUSH_BRACE_EXPANSION
2631 # define MAYBE_BRACES "{}"
2633 # define MAYBE_BRACES ""
2636 /* My analysis of quoting semantics tells me that state information
2637 * is associated with a destination, not a source.
2639 static void o_addqchr(o_string *o, int ch)
2642 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2647 o->data[o->length] = '\\';
2650 o->data[o->length] = ch;
2652 o->data[o->length] = '\0';
2655 static void o_addQchr(o_string *o, int ch)
2658 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2659 && strchr("*?[\\" MAYBE_BRACES, ch)
2662 o->data[o->length] = '\\';
2666 o->data[o->length] = ch;
2668 o->data[o->length] = '\0';
2671 static void o_addqblock(o_string *o, const char *str, int len)
2676 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2677 if (ordinary_cnt > len) /* paranoia */
2679 o_addblock(o, str, ordinary_cnt);
2680 if (ordinary_cnt == len)
2681 return; /* NUL is already added by o_addblock */
2682 str += ordinary_cnt;
2683 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2687 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2689 o->data[o->length] = '\\';
2693 o->data[o->length] = ch;
2696 o->data[o->length] = '\0';
2699 static void o_addQblock(o_string *o, const char *str, int len)
2701 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2702 o_addblock(o, str, len);
2705 o_addqblock(o, str, len);
2708 static void o_addQstr(o_string *o, const char *str)
2710 o_addQblock(o, str, strlen(str));
2713 /* A special kind of o_string for $VAR and `cmd` expansion.
2714 * It contains char* list[] at the beginning, which is grown in 16 element
2715 * increments. Actual string data starts at the next multiple of 16 * (char*).
2716 * list[i] contains an INDEX (int!) into this string data.
2717 * It means that if list[] needs to grow, data needs to be moved higher up
2718 * but list[i]'s need not be modified.
2719 * NB: remembering how many list[i]'s you have there is crucial.
2720 * o_finalize_list() operation post-processes this structure - calculates
2721 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2723 #if DEBUG_EXPAND || DEBUG_GLOB
2724 static void debug_print_list(const char *prefix, o_string *o, int n)
2726 char **list = (char**)o->data;
2727 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2731 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2732 prefix, list, n, string_start, o->length, o->maxlen,
2733 !!(o->o_expflags & EXP_FLAG_GLOB),
2735 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2738 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2739 o->data + (int)(uintptr_t)list[i] + string_start,
2740 o->data + (int)(uintptr_t)list[i] + string_start);
2744 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2746 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2750 # define debug_print_list(prefix, o, n) ((void)0)
2753 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2754 * in list[n] so that it points past last stored byte so far.
2755 * It returns n+1. */
2756 static int o_save_ptr_helper(o_string *o, int n)
2758 char **list = (char**)o->data;
2762 if (!o->has_empty_slot) {
2763 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2764 string_len = o->length - string_start;
2765 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2766 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2767 /* list[n] points to string_start, make space for 16 more pointers */
2768 o->maxlen += 0x10 * sizeof(list[0]);
2769 o->data = xrealloc(o->data, o->maxlen + 1);
2770 list = (char**)o->data;
2771 memmove(list + n + 0x10, list + n, string_len);
2772 o->length += 0x10 * sizeof(list[0]);
2774 debug_printf_list("list[%d]=%d string_start=%d\n",
2775 n, string_len, string_start);
2778 /* We have empty slot at list[n], reuse without growth */
2779 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2780 string_len = o->length - string_start;
2781 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2782 n, string_len, string_start);
2783 o->has_empty_slot = 0;
2785 o->has_quoted_part = 0;
2786 list[n] = (char*)(uintptr_t)string_len;
2790 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2791 static int o_get_last_ptr(o_string *o, int n)
2793 char **list = (char**)o->data;
2794 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2796 return ((int)(uintptr_t)list[n-1]) + string_start;
2799 #if ENABLE_HUSH_BRACE_EXPANSION
2800 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2801 * first, it processes even {a} (no commas), second,
2802 * I didn't manage to make it return strings when they don't match
2803 * existing files. Need to re-implement it.
2807 static int glob_needed(const char *s)
2816 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2822 /* Return pointer to next closing brace or to comma */
2823 static const char *next_brace_sub(const char *cp)
2827 while (*cp != '\0') {
2834 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2840 return *cp != '\0' ? cp : NULL;
2842 /* Recursive brace globber. Note: may garble pattern[]. */
2843 static int glob_brace(char *pattern, o_string *o, int n)
2845 char *new_pattern_buf;
2852 debug_printf_glob("glob_brace('%s')\n", pattern);
2858 if (*begin == '{') {
2859 /* Find the first sub-pattern and at the same time
2860 * find the rest after the closing brace */
2861 next = next_brace_sub(begin);
2863 /* An illegal expression */
2867 /* "{abc}" with no commas - illegal
2868 * brace expr, disregard and skip it */
2874 if (*begin == '\\' && begin[1] != '\0')
2878 debug_printf_glob("begin:%s\n", begin);
2879 debug_printf_glob("next:%s\n", next);
2881 /* Now find the end of the whole brace expression */
2883 while (*rest != '}') {
2884 rest = next_brace_sub(rest);
2886 /* An illegal expression */
2889 debug_printf_glob("rest:%s\n", rest);
2891 rest_len = strlen(++rest) + 1;
2893 /* We are sure the brace expression is well-formed */
2895 /* Allocate working buffer large enough for our work */
2896 new_pattern_buf = xmalloc(strlen(pattern));
2898 /* We have a brace expression. BEGIN points to the opening {,
2899 * NEXT points past the terminator of the first element, and REST
2900 * points past the final }. We will accumulate result names from
2901 * recursive runs for each brace alternative in the buffer using
2906 /* Construct the new glob expression */
2909 mempcpy(new_pattern_buf,
2910 /* We know the prefix for all sub-patterns */
2911 pattern, begin - pattern),
2915 /* Note: glob_brace() may garble new_pattern_buf[].
2916 * That's why we re-copy prefix every time (1st memcpy above).
2918 n = glob_brace(new_pattern_buf, o, n);
2920 /* We saw the last entry */
2924 next = next_brace_sub(next);
2926 free(new_pattern_buf);
2934 memset(&globdata, 0, sizeof(globdata));
2935 gr = glob(pattern, 0, NULL, &globdata);
2936 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2938 if (gr == GLOB_NOMATCH) {
2939 globfree(&globdata);
2940 /* NB: garbles parameter */
2941 unbackslash(pattern);
2942 o_addstr_with_NUL(o, pattern);
2943 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2944 return o_save_ptr_helper(o, n);
2946 if (gr == GLOB_NOSPACE)
2947 bb_error_msg_and_die(bb_msg_memory_exhausted);
2948 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2949 * but we didn't specify it. Paranoia again. */
2950 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2952 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2953 char **argv = globdata.gl_pathv;
2955 o_addstr_with_NUL(o, *argv);
2956 n = o_save_ptr_helper(o, n);
2962 globfree(&globdata);
2966 /* Performs globbing on last list[],
2967 * saving each result as a new list[].
2969 static int perform_glob(o_string *o, int n)
2971 char *pattern, *copy;
2973 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2975 return o_save_ptr_helper(o, n);
2976 pattern = o->data + o_get_last_ptr(o, n);
2977 debug_printf_glob("glob pattern '%s'\n", pattern);
2978 if (!glob_needed(pattern)) {
2979 /* unbackslash last string in o in place, fix length */
2980 o->length = unbackslash(pattern) - o->data;
2981 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2982 return o_save_ptr_helper(o, n);
2985 copy = xstrdup(pattern);
2986 /* "forget" pattern in o */
2987 o->length = pattern - o->data;
2988 n = glob_brace(copy, o, n);
2991 debug_print_list("perform_glob returning", o, n);
2995 #else /* !HUSH_BRACE_EXPANSION */
2998 static int glob_needed(const char *s)
3007 if (*s == '*' || *s == '[' || *s == '?')
3013 /* Performs globbing on last list[],
3014 * saving each result as a new list[].
3016 static int perform_glob(o_string *o, int n)
3022 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3024 return o_save_ptr_helper(o, n);
3025 pattern = o->data + o_get_last_ptr(o, n);
3026 debug_printf_glob("glob pattern '%s'\n", pattern);
3027 if (!glob_needed(pattern)) {
3029 /* unbackslash last string in o in place, fix length */
3030 o->length = unbackslash(pattern) - o->data;
3031 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3032 return o_save_ptr_helper(o, n);
3035 memset(&globdata, 0, sizeof(globdata));
3036 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3037 * If we glob "*.\*" and don't find anything, we need
3038 * to fall back to using literal "*.*", but GLOB_NOCHECK
3039 * will return "*.\*"!
3041 gr = glob(pattern, 0, NULL, &globdata);
3042 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3044 if (gr == GLOB_NOMATCH) {
3045 globfree(&globdata);
3048 if (gr == GLOB_NOSPACE)
3049 bb_error_msg_and_die(bb_msg_memory_exhausted);
3050 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3051 * but we didn't specify it. Paranoia again. */
3052 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3054 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3055 char **argv = globdata.gl_pathv;
3056 /* "forget" pattern in o */
3057 o->length = pattern - o->data;
3059 o_addstr_with_NUL(o, *argv);
3060 n = o_save_ptr_helper(o, n);
3066 globfree(&globdata);
3068 debug_print_list("perform_glob returning", o, n);
3072 #endif /* !HUSH_BRACE_EXPANSION */
3074 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3075 * Otherwise, just finish current list[] and start new */
3076 static int o_save_ptr(o_string *o, int n)
3078 if (o->o_expflags & EXP_FLAG_GLOB) {
3079 /* If o->has_empty_slot, list[n] was already globbed
3080 * (if it was requested back then when it was filled)
3081 * so don't do that again! */
3082 if (!o->has_empty_slot)
3083 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3085 return o_save_ptr_helper(o, n);
3088 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3089 static char **o_finalize_list(o_string *o, int n)
3094 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3096 debug_print_list("finalized", o, n);
3097 debug_printf_expand("finalized n:%d\n", n);
3098 list = (char**)o->data;
3099 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3103 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3108 static void free_pipe_list(struct pipe *pi);
3110 /* Returns pi->next - next pipe in the list */
3111 static struct pipe *free_pipe(struct pipe *pi)
3116 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3117 for (i = 0; i < pi->num_cmds; i++) {
3118 struct command *command;
3119 struct redir_struct *r, *rnext;
3121 command = &pi->cmds[i];
3122 debug_printf_clean(" command %d:\n", i);
3123 if (command->argv) {
3127 for (a = 0, p = command->argv; *p; a++, p++) {
3128 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3131 free_strings(command->argv);
3132 //command->argv = NULL;
3134 /* not "else if": on syntax error, we may have both! */
3135 if (command->group) {
3136 debug_printf_clean(" begin group (cmd_type:%d)\n",
3138 free_pipe_list(command->group);
3139 debug_printf_clean(" end group\n");
3140 //command->group = NULL;
3142 /* else is crucial here.
3143 * If group != NULL, child_func is meaningless */
3144 #if ENABLE_HUSH_FUNCTIONS
3145 else if (command->child_func) {
3146 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3147 command->child_func->parent_cmd = NULL;
3151 free(command->group_as_string);
3152 //command->group_as_string = NULL;
3154 for (r = command->redirects; r; r = rnext) {
3155 debug_printf_clean(" redirect %d%s",
3156 r->rd_fd, redir_table[r->rd_type].descrip);
3157 /* guard against the case >$FOO, where foo is unset or blank */
3158 if (r->rd_filename) {
3159 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3160 free(r->rd_filename);
3161 //r->rd_filename = NULL;
3163 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3167 //command->redirects = NULL;
3169 free(pi->cmds); /* children are an array, they get freed all at once */
3173 //pi->cmdtext = NULL;
3181 static void free_pipe_list(struct pipe *pi)
3185 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3187 debug_printf_clean("pipe followup code %d\n", pi->followup);
3193 /*** Parsing routines ***/
3195 #ifndef debug_print_tree
3196 static void debug_print_tree(struct pipe *pi, int lvl)
3198 static const char *const PIPE[] = {
3204 static const char *RES[] = {
3205 [RES_NONE ] = "NONE" ,
3208 [RES_THEN ] = "THEN" ,
3209 [RES_ELIF ] = "ELIF" ,
3210 [RES_ELSE ] = "ELSE" ,
3213 # if ENABLE_HUSH_LOOPS
3214 [RES_FOR ] = "FOR" ,
3215 [RES_WHILE] = "WHILE",
3216 [RES_UNTIL] = "UNTIL",
3218 [RES_DONE ] = "DONE" ,
3220 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3223 # if ENABLE_HUSH_CASE
3224 [RES_CASE ] = "CASE" ,
3225 [RES_CASE_IN ] = "CASE_IN" ,
3226 [RES_MATCH] = "MATCH",
3227 [RES_CASE_BODY] = "CASE_BODY",
3228 [RES_ESAC ] = "ESAC" ,
3230 [RES_XXXX ] = "XXXX" ,
3231 [RES_SNTX ] = "SNTX" ,
3233 static const char *const CMDTYPE[] = {
3237 # if ENABLE_HUSH_FUNCTIONS
3246 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3247 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3249 while (prn < pi->num_cmds) {
3250 struct command *command = &pi->cmds[prn];
3251 char **argv = command->argv;
3253 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3255 command->assignment_cnt);
3256 if (command->group) {
3257 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3258 CMDTYPE[command->cmd_type],
3261 , " group_as_string:", command->group_as_string
3266 debug_print_tree(command->group, lvl+1);
3270 if (argv) while (*argv) {
3271 fdprintf(2, " '%s'", *argv);
3281 #endif /* debug_print_tree */
3283 static struct pipe *new_pipe(void)
3286 pi = xzalloc(sizeof(struct pipe));
3287 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3291 /* Command (member of a pipe) is complete, or we start a new pipe
3292 * if ctx->command is NULL.
3293 * No errors possible here.
3295 static int done_command(struct parse_context *ctx)
3297 /* The command is really already in the pipe structure, so
3298 * advance the pipe counter and make a new, null command. */
3299 struct pipe *pi = ctx->pipe;
3300 struct command *command = ctx->command;
3302 #if 0 /* Instead we emit error message at run time */
3303 if (ctx->pending_redirect) {
3304 /* For example, "cmd >" (no filename to redirect to) */
3305 die_if_script("syntax error: %s", "invalid redirect");
3306 ctx->pending_redirect = NULL;
3311 if (IS_NULL_CMD(command)) {
3312 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3316 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3317 //debug_print_tree(ctx->list_head, 20);
3319 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3322 /* Only real trickiness here is that the uncommitted
3323 * command structure is not counted in pi->num_cmds. */
3324 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3325 ctx->command = command = &pi->cmds[pi->num_cmds];
3327 memset(command, 0, sizeof(*command));
3328 return pi->num_cmds; /* used only for 0/nonzero check */
3331 static void done_pipe(struct parse_context *ctx, pipe_style type)
3335 debug_printf_parse("done_pipe entered, followup %d\n", type);
3336 /* Close previous command */
3337 not_null = done_command(ctx);
3338 ctx->pipe->followup = type;
3340 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3341 ctx->ctx_inverted = 0;
3342 ctx->pipe->res_word = ctx->ctx_res_w;
3345 /* Without this check, even just <enter> on command line generates
3346 * tree of three NOPs (!). Which is harmless but annoying.
3347 * IOW: it is safe to do it unconditionally. */
3350 || ctx->ctx_res_w == RES_FI
3352 #if ENABLE_HUSH_LOOPS
3353 || ctx->ctx_res_w == RES_DONE
3354 || ctx->ctx_res_w == RES_FOR
3355 || ctx->ctx_res_w == RES_IN
3357 #if ENABLE_HUSH_CASE
3358 || ctx->ctx_res_w == RES_ESAC
3362 debug_printf_parse("done_pipe: adding new pipe: "
3363 "not_null:%d ctx->ctx_res_w:%d\n",
3364 not_null, ctx->ctx_res_w);
3366 ctx->pipe->next = new_p;
3368 /* RES_THEN, RES_DO etc are "sticky" -
3369 * they remain set for pipes inside if/while.
3370 * This is used to control execution.
3371 * RES_FOR and RES_IN are NOT sticky (needed to support
3372 * cases where variable or value happens to match a keyword):
3374 #if ENABLE_HUSH_LOOPS
3375 if (ctx->ctx_res_w == RES_FOR
3376 || ctx->ctx_res_w == RES_IN)
3377 ctx->ctx_res_w = RES_NONE;
3379 #if ENABLE_HUSH_CASE
3380 if (ctx->ctx_res_w == RES_MATCH)
3381 ctx->ctx_res_w = RES_CASE_BODY;
3382 if (ctx->ctx_res_w == RES_CASE)
3383 ctx->ctx_res_w = RES_CASE_IN;
3385 ctx->command = NULL; /* trick done_command below */
3386 /* Create the memory for command, roughly:
3387 * ctx->pipe->cmds = new struct command;
3388 * ctx->command = &ctx->pipe->cmds[0];
3391 //debug_print_tree(ctx->list_head, 10);
3393 debug_printf_parse("done_pipe return\n");
3396 static void initialize_context(struct parse_context *ctx)
3398 memset(ctx, 0, sizeof(*ctx));
3399 ctx->pipe = ctx->list_head = new_pipe();
3400 /* Create the memory for command, roughly:
3401 * ctx->pipe->cmds = new struct command;
3402 * ctx->command = &ctx->pipe->cmds[0];
3407 /* If a reserved word is found and processed, parse context is modified
3408 * and 1 is returned.
3411 struct reserved_combo {
3414 unsigned char assignment_flag;
3418 FLAG_END = (1 << RES_NONE ),
3420 FLAG_IF = (1 << RES_IF ),
3421 FLAG_THEN = (1 << RES_THEN ),
3422 FLAG_ELIF = (1 << RES_ELIF ),
3423 FLAG_ELSE = (1 << RES_ELSE ),
3424 FLAG_FI = (1 << RES_FI ),
3426 # if ENABLE_HUSH_LOOPS
3427 FLAG_FOR = (1 << RES_FOR ),
3428 FLAG_WHILE = (1 << RES_WHILE),
3429 FLAG_UNTIL = (1 << RES_UNTIL),
3430 FLAG_DO = (1 << RES_DO ),
3431 FLAG_DONE = (1 << RES_DONE ),
3432 FLAG_IN = (1 << RES_IN ),
3434 # if ENABLE_HUSH_CASE
3435 FLAG_MATCH = (1 << RES_MATCH),
3436 FLAG_ESAC = (1 << RES_ESAC ),
3438 FLAG_START = (1 << RES_XXXX ),
3441 static const struct reserved_combo* match_reserved_word(o_string *word)
3443 /* Mostly a list of accepted follow-up reserved words.
3444 * FLAG_END means we are done with the sequence, and are ready
3445 * to turn the compound list into a command.
3446 * FLAG_START means the word must start a new compound list.
3448 static const struct reserved_combo reserved_list[] = {
3450 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3451 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3452 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3453 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3454 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3455 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3457 # if ENABLE_HUSH_LOOPS
3458 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3459 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3460 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3461 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3462 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3463 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3465 # if ENABLE_HUSH_CASE
3466 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3467 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3470 const struct reserved_combo *r;
3472 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3473 if (strcmp(word->data, r->literal) == 0)
3478 /* Return 0: not a keyword, 1: keyword
3480 static int reserved_word(o_string *word, struct parse_context *ctx)
3482 # if ENABLE_HUSH_CASE
3483 static const struct reserved_combo reserved_match = {
3484 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3487 const struct reserved_combo *r;
3489 if (word->has_quoted_part)
3491 r = match_reserved_word(word);
3495 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3496 # if ENABLE_HUSH_CASE
3497 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3498 /* "case word IN ..." - IN part starts first MATCH part */
3499 r = &reserved_match;
3502 if (r->flag == 0) { /* '!' */
3503 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3504 syntax_error("! ! command");
3505 ctx->ctx_res_w = RES_SNTX;
3507 ctx->ctx_inverted = 1;
3510 if (r->flag & FLAG_START) {
3511 struct parse_context *old;
3513 old = xmalloc(sizeof(*old));
3514 debug_printf_parse("push stack %p\n", old);
3515 *old = *ctx; /* physical copy */
3516 initialize_context(ctx);
3518 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3519 syntax_error_at(word->data);
3520 ctx->ctx_res_w = RES_SNTX;
3523 /* "{...} fi" is ok. "{...} if" is not
3525 * if { echo foo; } then { echo bar; } fi */
3526 if (ctx->command->group)
3527 done_pipe(ctx, PIPE_SEQ);
3530 ctx->ctx_res_w = r->res;
3531 ctx->old_flag = r->flag;
3532 word->o_assignment = r->assignment_flag;
3533 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3535 if (ctx->old_flag & FLAG_END) {
3536 struct parse_context *old;
3538 done_pipe(ctx, PIPE_SEQ);
3539 debug_printf_parse("pop stack %p\n", ctx->stack);
3541 old->command->group = ctx->list_head;
3542 old->command->cmd_type = CMD_NORMAL;
3544 /* At this point, the compound command's string is in
3545 * ctx->as_string... except for the leading keyword!
3546 * Consider this example: "echo a | if true; then echo a; fi"
3547 * ctx->as_string will contain "true; then echo a; fi",
3548 * with "if " remaining in old->as_string!
3552 int len = old->as_string.length;
3553 /* Concatenate halves */
3554 o_addstr(&old->as_string, ctx->as_string.data);
3555 o_free_unsafe(&ctx->as_string);
3556 /* Find where leading keyword starts in first half */
3557 str = old->as_string.data + len;
3558 if (str > old->as_string.data)
3559 str--; /* skip whitespace after keyword */
3560 while (str > old->as_string.data && isalpha(str[-1]))
3562 /* Ugh, we're done with this horrid hack */
3563 old->command->group_as_string = xstrdup(str);
3564 debug_printf_parse("pop, remembering as:'%s'\n",
3565 old->command->group_as_string);
3568 *ctx = *old; /* physical copy */
3573 #endif /* HAS_KEYWORDS */
3575 /* Word is complete, look at it and update parsing context.
3576 * Normal return is 0. Syntax errors return 1.
3577 * Note: on return, word is reset, but not o_free'd!
3579 static int done_word(o_string *word, struct parse_context *ctx)
3581 struct command *command = ctx->command;
3583 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3584 if (word->length == 0 && !word->has_quoted_part) {
3585 debug_printf_parse("done_word return 0: true null, ignored\n");
3589 if (ctx->pending_redirect) {
3590 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3591 * only if run as "bash", not "sh" */
3592 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3594 * ...the word that follows the redirection operator
3595 * shall be subjected to tilde expansion, parameter expansion,
3596 * command substitution, arithmetic expansion, and quote
3597 * removal. Pathname expansion shall not be performed
3598 * on the word by a non-interactive shell; an interactive
3599 * shell may perform it, but shall do so only when
3600 * the expansion would result in one word."
3602 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3603 /* Cater for >\file case:
3604 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3605 * Same with heredocs:
3606 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3608 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3609 unbackslash(ctx->pending_redirect->rd_filename);
3610 /* Is it <<"HEREDOC"? */
3611 if (word->has_quoted_part) {
3612 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3615 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3616 ctx->pending_redirect = NULL;
3619 # if ENABLE_HUSH_CASE
3620 if (ctx->ctx_dsemicolon
3621 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3623 /* already done when ctx_dsemicolon was set to 1: */
3624 /* ctx->ctx_res_w = RES_MATCH; */
3625 ctx->ctx_dsemicolon = 0;
3628 if (!command->argv /* if it's the first word... */
3629 # if ENABLE_HUSH_LOOPS
3630 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3631 && ctx->ctx_res_w != RES_IN
3633 # if ENABLE_HUSH_CASE
3634 && ctx->ctx_res_w != RES_CASE
3637 int reserved = reserved_word(word, ctx);
3638 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3640 o_reset_to_empty_unquoted(word);
3641 debug_printf_parse("done_word return %d\n",
3642 (ctx->ctx_res_w == RES_SNTX));
3643 return (ctx->ctx_res_w == RES_SNTX);
3646 if (strcmp(word->data, "[[") == 0) {
3647 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3653 if (command->group) {
3654 /* "{ echo foo; } echo bar" - bad */
3655 syntax_error_at(word->data);
3656 debug_printf_parse("done_word return 1: syntax error, "
3657 "groups and arglists don't mix\n");
3661 /* If this word wasn't an assignment, next ones definitely
3662 * can't be assignments. Even if they look like ones. */
3663 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3664 && word->o_assignment != WORD_IS_KEYWORD
3666 word->o_assignment = NOT_ASSIGNMENT;
3668 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3669 command->assignment_cnt++;
3670 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3672 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3673 word->o_assignment = MAYBE_ASSIGNMENT;
3675 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3677 if (word->has_quoted_part
3678 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3679 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3680 /* (otherwise it's known to be not empty and is already safe) */
3682 /* exclude "$@" - it can expand to no word despite "" */
3683 char *p = word->data;
3684 while (p[0] == SPECIAL_VAR_SYMBOL
3685 && (p[1] & 0x7f) == '@'
3686 && p[2] == SPECIAL_VAR_SYMBOL
3691 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3692 debug_print_strings("word appended to argv", command->argv);
3695 #if ENABLE_HUSH_LOOPS
3696 if (ctx->ctx_res_w == RES_FOR) {
3697 if (word->has_quoted_part
3698 || !is_well_formed_var_name(command->argv[0], '\0')
3700 /* bash says just "not a valid identifier" */
3701 syntax_error("not a valid identifier in for");
3704 /* Force FOR to have just one word (variable name) */
3705 /* NB: basically, this makes hush see "for v in ..."
3706 * syntax as if it is "for v; in ...". FOR and IN become
3707 * two pipe structs in parse tree. */
3708 done_pipe(ctx, PIPE_SEQ);
3711 #if ENABLE_HUSH_CASE
3712 /* Force CASE to have just one word */
3713 if (ctx->ctx_res_w == RES_CASE) {
3714 done_pipe(ctx, PIPE_SEQ);
3718 o_reset_to_empty_unquoted(word);
3720 debug_printf_parse("done_word return 0\n");
3725 /* Peek ahead in the input to find out if we have a "&n" construct,
3726 * as in "2>&1", that represents duplicating a file descriptor.
3728 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3729 * REDIRFD_SYNTAX_ERR if syntax error,
3730 * REDIRFD_TO_FILE if no & was seen,
3731 * or the number found.
3734 #define parse_redir_right_fd(as_string, input) \
3735 parse_redir_right_fd(input)
3737 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3743 return REDIRFD_TO_FILE;
3745 ch = i_getch(input); /* get the & */
3746 nommu_addchr(as_string, ch);
3749 ch = i_getch(input);
3750 nommu_addchr(as_string, ch);
3751 return REDIRFD_CLOSE;
3755 while (ch != EOF && isdigit(ch)) {
3756 d = d*10 + (ch-'0');
3758 ch = i_getch(input);
3759 nommu_addchr(as_string, ch);
3764 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3766 bb_error_msg("ambiguous redirect");
3767 return REDIRFD_SYNTAX_ERR;
3770 /* Return code is 0 normal, 1 if a syntax error is detected
3772 static int parse_redirect(struct parse_context *ctx,
3775 struct in_str *input)
3777 struct command *command = ctx->command;
3778 struct redir_struct *redir;
3779 struct redir_struct **redirp;
3782 dup_num = REDIRFD_TO_FILE;
3783 if (style != REDIRECT_HEREDOC) {
3784 /* Check for a '>&1' type redirect */
3785 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3786 if (dup_num == REDIRFD_SYNTAX_ERR)
3789 int ch = i_peek(input);
3790 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3791 if (dup_num) { /* <<-... */
3792 ch = i_getch(input);
3793 nommu_addchr(&ctx->as_string, ch);
3798 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3799 int ch = i_peek(input);
3801 /* >|FILE redirect ("clobbering" >).
3802 * Since we do not support "set -o noclobber" yet,
3803 * >| and > are the same for now. Just eat |.
3805 ch = i_getch(input);
3806 nommu_addchr(&ctx->as_string, ch);
3810 /* Create a new redir_struct and append it to the linked list */
3811 redirp = &command->redirects;
3812 while ((redir = *redirp) != NULL) {
3813 redirp = &(redir->next);
3815 *redirp = redir = xzalloc(sizeof(*redir));
3816 /* redir->next = NULL; */
3817 /* redir->rd_filename = NULL; */
3818 redir->rd_type = style;
3819 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3821 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3822 redir_table[style].descrip);
3824 redir->rd_dup = dup_num;
3825 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3826 /* Erik had a check here that the file descriptor in question
3827 * is legit; I postpone that to "run time"
3828 * A "-" representation of "close me" shows up as a -3 here */
3829 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3830 redir->rd_fd, redir->rd_dup);
3832 #if 0 /* Instead we emit error message at run time */
3833 if (ctx->pending_redirect) {
3834 /* For example, "cmd > <file" */
3835 die_if_script("syntax error: %s", "invalid redirect");
3838 /* Set ctx->pending_redirect, so we know what to do at the
3839 * end of the next parsed word. */
3840 ctx->pending_redirect = redir;
3845 /* If a redirect is immediately preceded by a number, that number is
3846 * supposed to tell which file descriptor to redirect. This routine
3847 * looks for such preceding numbers. In an ideal world this routine
3848 * needs to handle all the following classes of redirects...
3849 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3850 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3851 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3852 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3854 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3856 * ... If n is quoted, the number shall not be recognized as part of
3857 * the redirection expression. For example:
3859 * writes the character 2 into file a"
3860 * We are getting it right by setting ->has_quoted_part on any \<char>
3862 * A -1 return means no valid number was found,
3863 * the caller should use the appropriate default for this redirection.
3865 static int redirect_opt_num(o_string *o)
3869 if (o->data == NULL)
3871 num = bb_strtou(o->data, NULL, 10);
3872 if (errno || num < 0)
3874 o_reset_to_empty_unquoted(o);
3879 #define fetch_till_str(as_string, input, word, skip_tabs) \
3880 fetch_till_str(input, word, skip_tabs)
3882 static char *fetch_till_str(o_string *as_string,
3883 struct in_str *input,
3887 o_string heredoc = NULL_O_STRING;
3889 int prev = 0; /* not \ */
3895 ch = i_getch(input);
3897 nommu_addchr(as_string, ch);
3898 if ((ch == '\n' || ch == EOF)
3899 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3901 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3902 heredoc.data[past_EOL] = '\0';
3903 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3904 return heredoc.data;
3906 while (ch == '\n') {
3907 o_addchr(&heredoc, ch);
3910 past_EOL = heredoc.length;
3912 ch = i_getch(input);
3914 nommu_addchr(as_string, ch);
3915 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3919 o_free_unsafe(&heredoc);
3922 o_addchr(&heredoc, ch);
3923 nommu_addchr(as_string, ch);
3924 if (prev == '\\' && ch == '\\')
3925 /* Correctly handle foo\\<eol> (not a line cont.) */
3926 prev = 0; /* not \ */
3932 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3933 * and load them all. There should be exactly heredoc_cnt of them.
3935 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3937 struct pipe *pi = ctx->list_head;
3939 while (pi && heredoc_cnt) {
3941 struct command *cmd = pi->cmds;
3943 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3945 cmd->argv ? cmd->argv[0] : "NONE");
3946 for (i = 0; i < pi->num_cmds; i++) {
3947 struct redir_struct *redir = cmd->redirects;
3949 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3950 i, cmd->argv ? cmd->argv[0] : "NONE");
3952 if (redir->rd_type == REDIRECT_HEREDOC) {
3955 redir->rd_type = REDIRECT_HEREDOC2;
3956 /* redir->rd_dup is (ab)used to indicate <<- */
3957 p = fetch_till_str(&ctx->as_string, input,
3958 redir->rd_filename, redir->rd_dup);
3960 syntax_error("unexpected EOF in here document");
3963 free(redir->rd_filename);
3964 redir->rd_filename = p;
3967 redir = redir->next;
3974 /* Should be 0. If it isn't, it's a parse error */
3976 bb_error_msg_and_die("heredoc BUG 2");
3982 static int run_list(struct pipe *pi);
3984 #define parse_stream(pstring, input, end_trigger) \
3985 parse_stream(input, end_trigger)
3987 static struct pipe *parse_stream(char **pstring,
3988 struct in_str *input,
3992 #if !ENABLE_HUSH_FUNCTIONS
3993 #define parse_group(dest, ctx, input, ch) \
3994 parse_group(ctx, input, ch)
3996 static int parse_group(o_string *dest, struct parse_context *ctx,
3997 struct in_str *input, int ch)
3999 /* dest contains characters seen prior to ( or {.
4000 * Typically it's empty, but for function defs,
4001 * it contains function name (without '()'). */
4002 struct pipe *pipe_list;
4004 struct command *command = ctx->command;
4006 debug_printf_parse("parse_group entered\n");
4007 #if ENABLE_HUSH_FUNCTIONS
4008 if (ch == '(' && !dest->has_quoted_part) {
4010 if (done_word(dest, ctx))
4013 goto skip; /* (... */
4014 if (command->argv[1]) { /* word word ... (... */
4015 syntax_error_unexpected_ch('(');
4018 /* it is "word(..." or "word (..." */
4020 ch = i_getch(input);
4021 while (ch == ' ' || ch == '\t');
4023 syntax_error_unexpected_ch(ch);
4026 nommu_addchr(&ctx->as_string, ch);
4028 ch = i_getch(input);
4029 while (ch == ' ' || ch == '\t' || ch == '\n');
4031 syntax_error_unexpected_ch(ch);
4034 nommu_addchr(&ctx->as_string, ch);
4035 command->cmd_type = CMD_FUNCDEF;
4040 #if 0 /* Prevented by caller */
4041 if (command->argv /* word [word]{... */
4042 || dest->length /* word{... */
4043 || dest->has_quoted_part /* ""{... */
4046 debug_printf_parse("parse_group return 1: "
4047 "syntax error, groups and arglists don't mix\n");
4052 #if ENABLE_HUSH_FUNCTIONS
4058 command->cmd_type = CMD_SUBSHELL;
4060 /* bash does not allow "{echo...", requires whitespace */
4062 if (ch != ' ' && ch != '\t' && ch != '\n'
4063 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4065 syntax_error_unexpected_ch(ch);
4069 ch = i_getch(input);
4070 nommu_addchr(&ctx->as_string, ch);
4076 # define as_string NULL
4078 char *as_string = NULL;
4080 pipe_list = parse_stream(&as_string, input, endch);
4083 o_addstr(&ctx->as_string, as_string);
4085 /* empty ()/{} or parse error? */
4086 if (!pipe_list || pipe_list == ERR_PTR) {
4087 /* parse_stream already emitted error msg */
4090 debug_printf_parse("parse_group return 1: "
4091 "parse_stream returned %p\n", pipe_list);
4094 command->group = pipe_list;
4096 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4097 command->group_as_string = as_string;
4098 debug_printf_parse("end of group, remembering as:'%s'\n",
4099 command->group_as_string);
4103 debug_printf_parse("parse_group return 0\n");
4105 /* command remains "open", available for possible redirects */
4108 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4113 ch = i_getch(input);
4116 ch2 = i_peek(input);
4119 /* backslash+newline, skip it */
4124 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4132 ch2 = i_peek2(input);
4135 /* backslash+newline, skip it */
4141 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4142 /* Subroutines for copying $(...) and `...` things */
4143 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4145 static int add_till_single_quote(o_string *dest, struct in_str *input)
4148 int ch = i_getch(input);
4150 syntax_error_unterm_ch('\'');
4158 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4159 static int add_till_double_quote(o_string *dest, struct in_str *input)
4162 int ch = i_getch(input);
4164 syntax_error_unterm_ch('"');
4169 if (ch == '\\') { /* \x. Copy both chars. */
4171 ch = i_getch(input);
4175 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4180 //if (ch == '$') ...
4183 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4185 * "Within the backquoted style of command substitution, backslash
4186 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4187 * The search for the matching backquote shall be satisfied by the first
4188 * backquote found without a preceding backslash; during this search,
4189 * if a non-escaped backquote is encountered within a shell comment,
4190 * a here-document, an embedded command substitution of the $(command)
4191 * form, or a quoted string, undefined results occur. A single-quoted
4192 * or double-quoted string that begins, but does not end, within the
4193 * "`...`" sequence produces undefined results."
4195 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4197 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4200 int ch = i_getch(input);
4204 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4205 ch = i_getch(input);
4209 && (!in_dquote || ch != '"')
4211 o_addchr(dest, '\\');
4215 syntax_error_unterm_ch('`');
4221 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4222 * quoting and nested ()s.
4223 * "With the $(command) style of command substitution, all characters
4224 * following the open parenthesis to the matching closing parenthesis
4225 * constitute the command. Any valid shell script can be used for command,
4226 * except a script consisting solely of redirections which produces
4227 * unspecified results."
4229 * echo $(echo '(TEST)' BEST) (TEST) BEST
4230 * echo $(echo 'TEST)' BEST) TEST) BEST
4231 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4233 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4234 * can contain arbitrary constructs, just like $(cmd).
4235 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4236 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4238 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4239 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4242 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4243 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4244 char end_char2 = end_ch >> 8;
4246 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4249 ch = i_getch(input);
4251 syntax_error_unterm_ch(end_ch);
4255 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4261 /* we look for closing )) of $((EXPR)) */
4262 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4263 i_getch(input); /* eat second ')' */
4268 if (ch == '(' || ch == '{') {
4269 ch = (ch == '(' ? ')' : '}');
4270 if (!add_till_closing_bracket(dest, input, ch))
4276 if (!add_till_single_quote(dest, input))
4282 if (!add_till_double_quote(dest, input))
4288 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4294 /* \x. Copy verbatim. Important for \(, \) */
4295 ch = i_getch(input);
4297 syntax_error_unterm_ch(')');
4302 /* "backslash+newline", ignore both */
4303 o_delchr(dest); /* undo insertion of '\' */
4313 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4315 /* Return code: 0 for OK, 1 for syntax error */
4317 #define parse_dollar(as_string, dest, input, quote_mask) \
4318 parse_dollar(dest, input, quote_mask)
4319 #define as_string NULL
4321 static int parse_dollar(o_string *as_string,
4323 struct in_str *input, unsigned char quote_mask)
4325 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4327 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4329 ch = i_getch(input);
4330 nommu_addchr(as_string, ch);
4332 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4334 debug_printf_parse(": '%c'\n", ch);
4335 o_addchr(dest, ch | quote_mask);
4337 ch = i_peek_and_eat_bkslash_nl(input);
4338 if (!isalnum(ch) && ch != '_') {
4339 /* End of variable name reached */
4342 ch = i_getch(input);
4343 nommu_addchr(as_string, ch);
4345 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4346 } else if (isdigit(ch)) {
4348 ch = i_getch(input);
4349 nommu_addchr(as_string, ch);
4350 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4351 debug_printf_parse(": '%c'\n", ch);
4352 o_addchr(dest, ch | quote_mask);
4353 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4354 } else switch (ch) {
4356 case '!': /* last bg pid */
4357 case '?': /* last exit code */
4358 case '#': /* number of args */
4359 case '*': /* args */
4360 case '@': /* args */
4361 goto make_one_char_var;
4363 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4365 ch = i_getch(input); /* eat '{' */
4366 nommu_addchr(as_string, ch);
4368 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4369 /* It should be ${?}, or ${#var},
4370 * or even ${?+subst} - operator acting on a special variable,
4371 * or the beginning of variable name.
4374 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4377 syntax_error_unterm_str("${name}");
4378 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4381 nommu_addchr(as_string, ch);
4384 /* It's possible to just call add_till_closing_bracket() at this point.
4385 * However, this regresses some of our testsuite cases
4386 * which check invalid constructs like ${%}.
4387 * Oh well... let's check that the var name part is fine... */
4393 debug_printf_parse(": '%c'\n", ch);
4395 ch = i_getch(input);
4396 nommu_addchr(as_string, ch);
4400 if (!isalnum(ch) && ch != '_') {
4402 unsigned char last_ch;
4403 /* handle parameter expansions
4404 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4406 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4407 goto bad_dollar_syntax;
4409 /* Eat everything until closing '}' (or ':') */
4413 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4415 /* It's ${var:N[:M]} thing */
4416 end_ch = '}' * 0x100 + ':';
4418 if (BASH_PATTERN_SUBST
4421 /* It's ${var/[/]pattern[/repl]} thing */
4422 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4424 nommu_addchr(as_string, '/');
4427 end_ch = '}' * 0x100 + '/';
4433 #if ENABLE_HUSH_DOLLAR_OPS
4434 last_ch = add_till_closing_bracket(dest, input, end_ch);
4435 if (last_ch == 0) /* error? */
4438 #error Simple code to only allow ${var} is not implemented
4441 o_addstr(as_string, dest->data + pos);
4442 o_addchr(as_string, last_ch);
4445 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4446 && (end_ch & 0xff00)
4448 /* close the first block: */
4449 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4450 /* while parsing N from ${var:N[:M]}
4451 * or pattern from ${var/[/]pattern[/repl]} */
4452 if ((end_ch & 0xff) == last_ch) {
4453 /* got ':' or '/'- parse the rest */
4458 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4459 /* it's ${var:N} - emulate :999999999 */
4460 o_addstr(dest, "999999999");
4461 } /* else: it's ${var/[/]pattern} */
4466 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4469 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4473 ch = i_getch(input);
4474 nommu_addchr(as_string, ch);
4475 # if ENABLE_FEATURE_SH_MATH
4476 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4477 ch = i_getch(input);
4478 nommu_addchr(as_string, ch);
4479 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4480 o_addchr(dest, /*quote_mask |*/ '+');
4483 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4484 return 0; /* error */
4486 o_addstr(as_string, dest->data + pos);
4487 o_addchr(as_string, ')');
4488 o_addchr(as_string, ')');
4490 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4494 # if ENABLE_HUSH_TICK
4495 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4496 o_addchr(dest, quote_mask | '`');
4499 if (!add_till_closing_bracket(dest, input, ')'))
4500 return 0; /* error */
4502 o_addstr(as_string, dest->data + pos);
4503 o_addchr(as_string, ')');
4505 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4511 ch = i_getch(input);
4512 nommu_addchr(as_string, ch);
4513 ch = i_peek_and_eat_bkslash_nl(input);
4514 if (isalnum(ch)) { /* it's $_name or $_123 */
4519 /* TODO: $_ and $-: */
4520 /* $_ Shell or shell script name; or last argument of last command
4521 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4522 * but in command's env, set to full pathname used to invoke it */
4523 /* $- Option flags set by set builtin or shell options (-i etc) */
4525 o_addQchr(dest, '$');
4527 debug_printf_parse("parse_dollar return 1 (ok)\n");
4533 # if BASH_PATTERN_SUBST
4534 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4535 encode_string(dest, input, dquote_end, process_bkslash)
4537 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4538 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4539 encode_string(dest, input, dquote_end)
4541 #define as_string NULL
4545 # if BASH_PATTERN_SUBST
4546 /* all parameters are needed, no macro tricks */
4548 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4549 encode_string(as_string, dest, input, dquote_end)
4552 static int encode_string(o_string *as_string,
4554 struct in_str *input,
4556 int process_bkslash)
4558 #if !BASH_PATTERN_SUBST
4559 const int process_bkslash = 1;
4565 ch = i_getch(input);
4567 nommu_addchr(as_string, ch);
4568 if (ch == dquote_end) { /* may be only '"' or EOF */
4569 debug_printf_parse("encode_string return 1 (ok)\n");
4572 /* note: can't move it above ch == dquote_end check! */
4574 syntax_error_unterm_ch('"');
4575 return 0; /* error */
4579 next = i_peek(input);
4581 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4582 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4583 if (process_bkslash && ch == '\\') {
4585 syntax_error("\\<eof>");
4589 * "The backslash retains its special meaning [in "..."]
4590 * only when followed by one of the following characters:
4591 * $, `, ", \, or <newline>. A double quote may be quoted
4592 * within double quotes by preceding it with a backslash."
4593 * NB: in (unquoted) heredoc, above does not apply to ",
4594 * therefore we check for it by "next == dquote_end" cond.
4596 if (next == dquote_end || strchr("$`\\\n", next)) {
4597 ch = i_getch(input); /* eat next */
4599 goto again; /* skip \<newline> */
4600 } /* else: ch remains == '\\', and we double it below: */
4601 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4602 nommu_addchr(as_string, ch);
4606 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4607 debug_printf_parse("encode_string return 0: "
4608 "parse_dollar returned 0 (error)\n");
4613 #if ENABLE_HUSH_TICK
4615 //unsigned pos = dest->length;
4616 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4617 o_addchr(dest, 0x80 | '`');
4618 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4619 return 0; /* error */
4620 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4621 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4625 o_addQchr(dest, ch);
4631 * Scan input until EOF or end_trigger char.
4632 * Return a list of pipes to execute, or NULL on EOF
4633 * or if end_trigger character is met.
4634 * On syntax error, exit if shell is not interactive,
4635 * reset parsing machinery and start parsing anew,
4636 * or return ERR_PTR.
4638 static struct pipe *parse_stream(char **pstring,
4639 struct in_str *input,
4642 struct parse_context ctx;
4643 o_string dest = NULL_O_STRING;
4646 /* Single-quote triggers a bypass of the main loop until its mate is
4647 * found. When recursing, quote state is passed in via dest->o_expflags.
4649 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4650 end_trigger ? end_trigger : 'X');
4653 /* If very first arg is "" or '', dest.data may end up NULL.
4654 * Preventing this: */
4655 o_addchr(&dest, '\0');
4658 /* We used to separate words on $IFS here. This was wrong.
4659 * $IFS is used only for word splitting when $var is expanded,
4660 * here we should use blank chars as separators, not $IFS
4663 if (MAYBE_ASSIGNMENT != 0)
4664 dest.o_assignment = MAYBE_ASSIGNMENT;
4665 initialize_context(&ctx);
4668 const char *is_blank;
4669 const char *is_special;
4673 redir_type redir_style;
4675 ch = i_getch(input);
4676 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4677 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4682 syntax_error_unterm_str("here document");
4685 if (end_trigger == ')') {
4686 syntax_error_unterm_ch('(');
4689 if (end_trigger == '}') {
4690 syntax_error_unterm_ch('{');
4694 if (done_word(&dest, &ctx)) {
4698 done_pipe(&ctx, PIPE_SEQ);
4700 /* If we got nothing... */
4701 /* (this makes bare "&" cmd a no-op.
4702 * bash says: "syntax error near unexpected token '&'") */
4703 if (pi->num_cmds == 0
4704 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4710 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4712 *pstring = ctx.as_string.data;
4714 o_free_unsafe(&ctx.as_string);
4717 debug_printf_parse("parse_stream return %p\n", pi);
4720 nommu_addchr(&ctx.as_string, ch);
4724 next = i_peek(input);
4726 is_special = "{}<>;&|()#'" /* special outside of "str" */
4727 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4728 /* Are { and } special here? */
4729 if (ctx.command->argv /* word [word]{... - non-special */
4730 || dest.length /* word{... - non-special */
4731 || dest.has_quoted_part /* ""{... - non-special */
4732 || (next != ';' /* }; - special */
4733 && next != ')' /* }) - special */
4734 && next != '(' /* {( - special */
4735 && next != '&' /* }& and }&& ... - special */
4736 && next != '|' /* }|| ... - special */
4737 && !strchr(defifs, next) /* {word - non-special */
4740 /* They are not special, skip "{}" */
4743 is_special = strchr(is_special, ch);
4744 is_blank = strchr(defifs, ch);
4746 if (!is_special && !is_blank) { /* ordinary char */
4748 o_addQchr(&dest, ch);
4749 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4750 || dest.o_assignment == WORD_IS_KEYWORD)
4752 && is_well_formed_var_name(dest.data, '=')
4754 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4755 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4761 if (done_word(&dest, &ctx)) {
4765 /* Is this a case when newline is simply ignored?
4767 * "cmd | <newline> cmd ..."
4768 * "case ... in <newline> word) ..."
4770 if (IS_NULL_CMD(ctx.command)
4771 && dest.length == 0 && !dest.has_quoted_part
4773 /* This newline can be ignored. But...
4774 * Without check #1, interactive shell
4775 * ignores even bare <newline>,
4776 * and shows the continuation prompt:
4777 * ps1_prompt$ <enter>
4778 * ps2> _ <=== wrong, should be ps1
4779 * Without check #2, "cmd & <newline>"
4780 * is similarly mistreated.
4781 * (BTW, this makes "cmd & cmd"
4782 * and "cmd && cmd" non-orthogonal.
4783 * Really, ask yourself, why
4784 * "cmd && <newline>" doesn't start
4785 * cmd but waits for more input?
4788 struct pipe *pi = ctx.list_head;
4789 if (pi->num_cmds != 0 /* check #1 */
4790 && pi->followup != PIPE_BG /* check #2 */
4795 /* Treat newline as a command separator. */
4796 done_pipe(&ctx, PIPE_SEQ);
4797 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4799 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4804 dest.o_assignment = MAYBE_ASSIGNMENT;
4805 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4807 /* note: if (is_blank) continue;
4808 * will still trigger for us */
4812 /* "cmd}" or "cmd }..." without semicolon or &:
4813 * } is an ordinary char in this case, even inside { cmd; }
4814 * Pathological example: { ""}; } should exec "}" cmd
4817 if (dest.length != 0 /* word} */
4818 || dest.has_quoted_part /* ""} */
4822 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4823 /* Generally, there should be semicolon: "cmd; }"
4824 * However, bash allows to omit it if "cmd" is
4825 * a group. Examples:
4828 * { echo 0 >&2 | { echo 1; } }
4829 * { while false; do :; done }
4830 * { case a in b) ;; esac }
4832 if (ctx.command->group)
4836 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4837 /* Can't be an end of {cmd}, skip the check */
4838 goto skip_end_trigger;
4839 /* else: } does terminate a group */
4842 if (end_trigger && end_trigger == ch
4843 && (ch != ';' || heredoc_cnt == 0)
4844 #if ENABLE_HUSH_CASE
4846 || ctx.ctx_res_w != RES_MATCH
4847 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4852 /* This is technically valid:
4853 * { cat <<HERE; }; echo Ok
4857 * but we don't support this.
4858 * We require heredoc to be in enclosing {}/(),
4861 syntax_error_unterm_str("here document");
4864 if (done_word(&dest, &ctx)) {
4867 done_pipe(&ctx, PIPE_SEQ);
4868 dest.o_assignment = MAYBE_ASSIGNMENT;
4869 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4870 /* Do we sit outside of any if's, loops or case's? */
4872 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4876 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4878 *pstring = ctx.as_string.data;
4880 o_free_unsafe(&ctx.as_string);
4883 debug_printf_parse("parse_stream return %p: "
4884 "end_trigger char found\n",
4886 return ctx.list_head;
4893 /* Catch <, > before deciding whether this word is
4894 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4897 redir_fd = redirect_opt_num(&dest);
4898 if (done_word(&dest, &ctx)) {
4901 redir_style = REDIRECT_OVERWRITE;
4903 redir_style = REDIRECT_APPEND;
4904 ch = i_getch(input);
4905 nommu_addchr(&ctx.as_string, ch);
4908 else if (next == '(') {
4909 syntax_error(">(process) not supported");
4913 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4915 continue; /* back to top of while (1) */
4917 redir_fd = redirect_opt_num(&dest);
4918 if (done_word(&dest, &ctx)) {
4921 redir_style = REDIRECT_INPUT;
4923 redir_style = REDIRECT_HEREDOC;
4925 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4926 ch = i_getch(input);
4927 nommu_addchr(&ctx.as_string, ch);
4928 } else if (next == '>') {
4929 redir_style = REDIRECT_IO;
4930 ch = i_getch(input);
4931 nommu_addchr(&ctx.as_string, ch);
4934 else if (next == '(') {
4935 syntax_error("<(process) not supported");
4939 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4941 continue; /* back to top of while (1) */
4943 if (dest.length == 0 && !dest.has_quoted_part) {
4944 /* skip "#comment" */
4947 if (ch == EOF || ch == '\n')
4950 /* note: we do not add it to &ctx.as_string */
4952 nommu_addchr(&ctx.as_string, '\n');
4953 continue; /* back to top of while (1) */
4958 /* It's "\<newline>" */
4960 /* Remove trailing '\' from ctx.as_string */
4961 ctx.as_string.data[--ctx.as_string.length] = '\0';
4963 ch = i_getch(input); /* eat it */
4964 continue; /* back to top of while (1) */
4969 if (dest.o_assignment == MAYBE_ASSIGNMENT
4970 /* check that we are not in word in "a=1 2>word b=1": */
4971 && !ctx.pending_redirect
4973 /* ch is a special char and thus this word
4974 * cannot be an assignment */
4975 dest.o_assignment = NOT_ASSIGNMENT;
4976 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4979 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4982 case '#': /* non-comment #: "echo a#b" etc */
4983 o_addQchr(&dest, ch);
4987 syntax_error("\\<eof>");
4990 ch = i_getch(input);
4991 /* note: ch != '\n' (that case does not reach this place) */
4992 o_addchr(&dest, '\\');
4993 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4994 o_addchr(&dest, ch);
4995 nommu_addchr(&ctx.as_string, ch);
4996 /* Example: echo Hello \2>file
4997 * we need to know that word 2 is quoted */
4998 dest.has_quoted_part = 1;
5001 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5002 debug_printf_parse("parse_stream parse error: "
5003 "parse_dollar returned 0 (error)\n");
5008 dest.has_quoted_part = 1;
5009 if (next == '\'' && !ctx.pending_redirect) {
5010 insert_empty_quoted_str_marker:
5011 nommu_addchr(&ctx.as_string, next);
5012 i_getch(input); /* eat second ' */
5013 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5014 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5017 ch = i_getch(input);
5019 syntax_error_unterm_ch('\'');
5022 nommu_addchr(&ctx.as_string, ch);
5025 o_addqchr(&dest, ch);
5030 dest.has_quoted_part = 1;
5031 if (next == '"' && !ctx.pending_redirect)
5032 goto insert_empty_quoted_str_marker;
5033 if (dest.o_assignment == NOT_ASSIGNMENT)
5034 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5035 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5037 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5039 #if ENABLE_HUSH_TICK
5041 USE_FOR_NOMMU(unsigned pos;)
5043 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5044 o_addchr(&dest, '`');
5045 USE_FOR_NOMMU(pos = dest.length;)
5046 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5049 o_addstr(&ctx.as_string, dest.data + pos);
5050 o_addchr(&ctx.as_string, '`');
5052 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5053 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5058 #if ENABLE_HUSH_CASE
5061 if (done_word(&dest, &ctx)) {
5064 done_pipe(&ctx, PIPE_SEQ);
5065 #if ENABLE_HUSH_CASE
5066 /* Eat multiple semicolons, detect
5067 * whether it means something special */
5072 ch = i_getch(input);
5073 nommu_addchr(&ctx.as_string, ch);
5074 if (ctx.ctx_res_w == RES_CASE_BODY) {
5075 ctx.ctx_dsemicolon = 1;
5076 ctx.ctx_res_w = RES_MATCH;
5082 /* We just finished a cmd. New one may start
5083 * with an assignment */
5084 dest.o_assignment = MAYBE_ASSIGNMENT;
5085 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5088 if (done_word(&dest, &ctx)) {
5092 ch = i_getch(input);
5093 nommu_addchr(&ctx.as_string, ch);
5094 done_pipe(&ctx, PIPE_AND);
5096 done_pipe(&ctx, PIPE_BG);
5100 if (done_word(&dest, &ctx)) {
5103 #if ENABLE_HUSH_CASE
5104 if (ctx.ctx_res_w == RES_MATCH)
5105 break; /* we are in case's "word | word)" */
5107 if (next == '|') { /* || */
5108 ch = i_getch(input);
5109 nommu_addchr(&ctx.as_string, ch);
5110 done_pipe(&ctx, PIPE_OR);
5112 /* we could pick up a file descriptor choice here
5113 * with redirect_opt_num(), but bash doesn't do it.
5114 * "echo foo 2| cat" yields "foo 2". */
5119 #if ENABLE_HUSH_CASE
5120 /* "case... in [(]word)..." - skip '(' */
5121 if (ctx.ctx_res_w == RES_MATCH
5122 && ctx.command->argv == NULL /* not (word|(... */
5123 && dest.length == 0 /* not word(... */
5124 && dest.has_quoted_part == 0 /* not ""(... */
5130 if (parse_group(&dest, &ctx, input, ch) != 0) {
5135 #if ENABLE_HUSH_CASE
5136 if (ctx.ctx_res_w == RES_MATCH)
5140 /* proper use of this character is caught by end_trigger:
5141 * if we see {, we call parse_group(..., end_trigger='}')
5142 * and it will match } earlier (not here). */
5143 syntax_error_unexpected_ch(ch);
5144 G.last_exitcode = 2;
5148 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5153 G.last_exitcode = 1;
5156 struct parse_context *pctx;
5157 IF_HAS_KEYWORDS(struct parse_context *p2;)
5159 /* Clean up allocated tree.
5160 * Sample for finding leaks on syntax error recovery path.
5161 * Run it from interactive shell, watch pmap `pidof hush`.
5162 * while if false; then false; fi; do break; fi
5163 * Samples to catch leaks at execution:
5164 * while if (true | { true;}); then echo ok; fi; do break; done
5165 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5169 /* Update pipe/command counts,
5170 * otherwise freeing may miss some */
5171 done_pipe(pctx, PIPE_SEQ);
5172 debug_printf_clean("freeing list %p from ctx %p\n",
5173 pctx->list_head, pctx);
5174 debug_print_tree(pctx->list_head, 0);
5175 free_pipe_list(pctx->list_head);
5176 debug_printf_clean("freed list %p\n", pctx->list_head);
5178 o_free_unsafe(&pctx->as_string);
5180 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5184 IF_HAS_KEYWORDS(pctx = p2;)
5185 } while (HAS_KEYWORDS && pctx);
5198 /*** Execution routines ***/
5200 /* Expansion can recurse, need forward decls: */
5201 #if !BASH_PATTERN_SUBST
5202 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5203 #define expand_string_to_string(str, do_unbackslash) \
5204 expand_string_to_string(str)
5206 static char *expand_string_to_string(const char *str, int do_unbackslash);
5207 #if ENABLE_HUSH_TICK
5208 static int process_command_subs(o_string *dest, const char *s);
5211 /* expand_strvec_to_strvec() takes a list of strings, expands
5212 * all variable references within and returns a pointer to
5213 * a list of expanded strings, possibly with larger number
5214 * of strings. (Think VAR="a b"; echo $VAR).
5215 * This new list is allocated as a single malloc block.
5216 * NULL-terminated list of char* pointers is at the beginning of it,
5217 * followed by strings themselves.
5218 * Caller can deallocate entire list by single free(list). */
5220 /* A horde of its helpers come first: */
5222 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5224 while (--len >= 0) {
5227 #if ENABLE_HUSH_BRACE_EXPANSION
5228 if (c == '{' || c == '}') {
5229 /* { -> \{, } -> \} */
5231 /* And now we want to add { or } and continue:
5234 * luckily, just falling throught achieves this.
5240 /* \z -> \\\z; \<eol> -> \\<eol> */
5245 o_addchr(o, *str++);
5251 /* Store given string, finalizing the word and starting new one whenever
5252 * we encounter IFS char(s). This is used for expanding variable values.
5253 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5254 * Return in *ended_with_ifs:
5255 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5257 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5259 int last_is_ifs = 0;
5264 if (!*str) /* EOL - do not finalize word */
5266 word_len = strcspn(str, G.ifs);
5268 /* We have WORD_LEN leading non-IFS chars */
5269 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5270 o_addblock(output, str, word_len);
5272 /* Protect backslashes against globbing up :)
5273 * Example: "v='\*'; echo b$v" prints "b\*"
5274 * (and does not try to glob on "*")
5276 o_addblock_duplicate_backslash(output, str, word_len);
5277 /*/ Why can't we do it easier? */
5278 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5279 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5283 if (!*str) /* EOL - do not finalize word */
5287 /* We know str here points to at least one IFS char */
5289 str += strspn(str, G.ifs); /* skip IFS chars */
5290 if (!*str) /* EOL - do not finalize word */
5293 /* Start new word... but not always! */
5294 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5295 if (output->has_quoted_part
5296 /* Case "v=' a'; echo $v":
5297 * here nothing precedes the space in $v expansion,
5298 * therefore we should not finish the word
5299 * (IOW: if there *is* word to finalize, only then do it):
5301 || (n > 0 && output->data[output->length - 1])
5303 o_addchr(output, '\0');
5304 debug_print_list("expand_on_ifs", output, n);
5305 n = o_save_ptr(output, n);
5310 *ended_with_ifs = last_is_ifs;
5311 debug_print_list("expand_on_ifs[1]", output, n);
5315 /* Helper to expand $((...)) and heredoc body. These act as if
5316 * they are in double quotes, with the exception that they are not :).
5317 * Just the rules are similar: "expand only $var and `cmd`"
5319 * Returns malloced string.
5320 * As an optimization, we return NULL if expansion is not needed.
5322 #if !BASH_PATTERN_SUBST
5323 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5324 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5325 encode_then_expand_string(str)
5327 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5330 struct in_str input;
5331 o_string dest = NULL_O_STRING;
5333 if (!strchr(str, '$')
5334 && !strchr(str, '\\')
5335 #if ENABLE_HUSH_TICK
5336 && !strchr(str, '`')
5342 /* We need to expand. Example:
5343 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5345 setup_string_in_str(&input, str);
5346 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5347 //TODO: error check (encode_string returns 0 on error)?
5348 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5349 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5350 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5351 o_free_unsafe(&dest);
5355 #if ENABLE_FEATURE_SH_MATH
5356 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5358 arith_state_t math_state;
5362 math_state.lookupvar = get_local_var_value;
5363 math_state.setvar = set_local_var_from_halves;
5364 //math_state.endofname = endofname;
5365 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5366 res = arith(&math_state, exp_str ? exp_str : arg);
5369 *errmsg_p = math_state.errmsg;
5370 if (math_state.errmsg)
5371 die_if_script(math_state.errmsg);
5376 #if BASH_PATTERN_SUBST
5377 /* ${var/[/]pattern[/repl]} helpers */
5378 static char *strstr_pattern(char *val, const char *pattern, int *size)
5381 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5382 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5389 /* Optimization: if "*pat" did not match the start of "string",
5390 * we know that "tring", "ring" etc will not match too:
5392 if (pattern[0] == '*')
5397 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5399 char *result = NULL;
5400 unsigned res_len = 0;
5401 unsigned repl_len = strlen(repl);
5405 char *s = strstr_pattern(val, pattern, &size);
5409 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5410 memcpy(result + res_len, val, s - val);
5412 strcpy(result + res_len, repl);
5413 res_len += repl_len;
5414 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5420 if (val[0] && result) {
5421 result = xrealloc(result, res_len + strlen(val) + 1);
5422 strcpy(result + res_len, val);
5423 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5425 debug_printf_varexp("result:'%s'\n", result);
5428 #endif /* BASH_PATTERN_SUBST */
5431 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5433 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5435 const char *val = NULL;
5436 char *to_be_freed = NULL;
5441 char exp_save = exp_save; /* for compiler */
5442 char *exp_saveptr; /* points to expansion operator */
5443 char *exp_word = exp_word; /* for compiler */
5446 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5448 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5450 first_char = arg[0] = arg0 & 0x7f;
5453 if (first_char == '#' /* ${#... */
5454 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5456 /* It must be length operator: ${#var} */
5460 /* Maybe handle parameter expansion */
5461 if (exp_saveptr /* if 2nd char is one of expansion operators */
5462 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5464 /* ${?:0}, ${#[:]%0} etc */
5465 exp_saveptr = var + 1;
5467 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5468 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5470 exp_op = exp_save = *exp_saveptr;
5472 exp_word = exp_saveptr + 1;
5473 if (exp_op == ':') {
5474 exp_op = *exp_word++;
5475 //TODO: try ${var:} and ${var:bogus} in non-bash config
5477 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5479 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5484 *exp_saveptr = '\0';
5485 } /* else: it's not an expansion op, but bare ${var} */
5488 /* Look up the variable in question */
5489 if (isdigit(var[0])) {
5490 /* parse_dollar should have vetted var for us */
5491 int n = xatoi_positive(var);
5492 if (n < G.global_argc)
5493 val = G.global_argv[n];
5494 /* else val remains NULL: $N with too big N */
5498 val = utoa(G.root_pid);
5500 case '!': /* bg pid */
5501 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5503 case '?': /* exitcode */
5504 val = utoa(G.last_exitcode);
5506 case '#': /* argc */
5507 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5510 val = get_local_var_value(var);
5514 /* Handle any expansions */
5515 if (exp_op == 'L') {
5516 reinit_unicode_for_hush();
5517 debug_printf_expand("expand: length(%s)=", val);
5518 val = utoa(val ? unicode_strlen(val) : 0);
5519 debug_printf_expand("%s\n", val);
5520 } else if (exp_op) {
5521 if (exp_op == '%' || exp_op == '#') {
5522 /* Standard-mandated substring removal ops:
5523 * ${parameter%word} - remove smallest suffix pattern
5524 * ${parameter%%word} - remove largest suffix pattern
5525 * ${parameter#word} - remove smallest prefix pattern
5526 * ${parameter##word} - remove largest prefix pattern
5528 * Word is expanded to produce a glob pattern.
5529 * Then var's value is matched to it and matching part removed.
5531 if (val && val[0]) {
5535 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5536 if (exp_op == *exp_word) /* ## or %% */
5538 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5540 exp_word = exp_exp_word;
5541 /* HACK ALERT. We depend here on the fact that
5542 * G.global_argv and results of utoa and get_local_var_value
5543 * are actually in writable memory:
5544 * scan_and_match momentarily stores NULs there. */
5546 loc = scan_and_match(t, exp_word, scan_flags);
5547 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5548 // exp_op, t, exp_word, loc);
5550 if (loc) { /* match was found */
5551 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5552 val = loc; /* take right part */
5554 val = to_be_freed = xstrndup(val, loc - val); /* left */
5558 #if BASH_PATTERN_SUBST
5559 else if (exp_op == '/' || exp_op == '\\') {
5560 /* It's ${var/[/]pattern[/repl]} thing.
5561 * Note that in encoded form it has TWO parts:
5562 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5563 * and if // is used, it is encoded as \:
5564 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5566 /* Empty variable always gives nothing: */
5567 // "v=''; echo ${v/*/w}" prints "", not "w"
5568 if (val && val[0]) {
5569 /* pattern uses non-standard expansion.
5570 * repl should be unbackslashed and globbed
5571 * by the usual expansion rules:
5573 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5574 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5575 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5576 * v='a bz'; echo ${v/a*z/\z} prints "z"
5577 * (note that a*z _pattern_ is never globbed!)
5579 char *pattern, *repl, *t;
5580 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5582 pattern = xstrdup(exp_word);
5583 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5584 *p++ = SPECIAL_VAR_SYMBOL;
5586 p = strchr(p, SPECIAL_VAR_SYMBOL);
5588 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5589 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5590 /* HACK ALERT. We depend here on the fact that
5591 * G.global_argv and results of utoa and get_local_var_value
5592 * are actually in writable memory:
5593 * replace_pattern momentarily stores NULs there. */
5595 to_be_freed = replace_pattern(t,
5597 (repl ? repl : exp_word),
5599 if (to_be_freed) /* at least one replace happened */
5605 #endif /* BASH_PATTERN_SUBST */
5606 else if (exp_op == ':') {
5607 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5608 /* It's ${var:N[:M]} bashism.
5609 * Note that in encoded form it has TWO parts:
5610 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5615 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5618 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5619 *p++ = SPECIAL_VAR_SYMBOL;
5621 p = strchr(p, SPECIAL_VAR_SYMBOL);
5623 len = expand_and_evaluate_arith(exp_word, &errmsg);
5626 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5627 if (len >= 0) { /* bash compat: len < 0 is illegal */
5628 if (beg < 0) /* bash compat */
5630 debug_printf_varexp("from val:'%s'\n", val);
5631 if (len == 0 || !val || beg >= strlen(val)) {
5635 /* Paranoia. What if user entered 9999999999999
5636 * which fits in arith_t but not int? */
5639 val = to_be_freed = xstrndup(val + beg, len);
5641 debug_printf_varexp("val:'%s'\n", val);
5643 #endif /* HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH */
5645 die_if_script("malformed ${%s:...}", var);
5648 } else { /* one of "-=+?" */
5649 /* Standard-mandated substitution ops:
5650 * ${var?word} - indicate error if unset
5651 * If var is unset, word (or a message indicating it is unset
5652 * if word is null) is written to standard error
5653 * and the shell exits with a non-zero exit status.
5654 * Otherwise, the value of var is substituted.
5655 * ${var-word} - use default value
5656 * If var is unset, word is substituted.
5657 * ${var=word} - assign and use default value
5658 * If var is unset, word is assigned to var.
5659 * In all cases, final value of var is substituted.
5660 * ${var+word} - use alternative value
5661 * If var is unset, null is substituted.
5662 * Otherwise, word is substituted.
5664 * Word is subjected to tilde expansion, parameter expansion,
5665 * command substitution, and arithmetic expansion.
5666 * If word is not needed, it is not expanded.
5668 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5669 * but also treat null var as if it is unset.
5671 int use_word = (!val || ((exp_save == ':') && !val[0]));
5673 use_word = !use_word;
5674 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5675 (exp_save == ':') ? "true" : "false", use_word);
5677 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5679 exp_word = to_be_freed;
5680 if (exp_op == '?') {
5681 /* mimic bash message */
5682 die_if_script("%s: %s",
5684 exp_word[0] ? exp_word : "parameter null or not set"
5686 //TODO: how interactive bash aborts expansion mid-command?
5691 if (exp_op == '=') {
5692 /* ${var=[word]} or ${var:=[word]} */
5693 if (isdigit(var[0]) || var[0] == '#') {
5694 /* mimic bash message */
5695 die_if_script("$%s: cannot assign in this way", var);
5698 char *new_var = xasprintf("%s=%s", var, val);
5699 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5703 } /* one of "-=+?" */
5705 *exp_saveptr = exp_save;
5711 *to_be_freed_pp = to_be_freed;
5715 /* Expand all variable references in given string, adding words to list[]
5716 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5717 * to be filled). This routine is extremely tricky: has to deal with
5718 * variables/parameters with whitespace, $* and $@, and constructs like
5719 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5720 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5722 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5723 * expansion of right-hand side of assignment == 1-element expand.
5725 char cant_be_null = 0; /* only bit 0x80 matters */
5726 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5729 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5730 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5731 debug_print_list("expand_vars_to_list", output, n);
5732 n = o_save_ptr(output, n);
5733 debug_print_list("expand_vars_to_list[0]", output, n);
5735 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5737 char *to_be_freed = NULL;
5738 const char *val = NULL;
5739 #if ENABLE_HUSH_TICK
5740 o_string subst_result = NULL_O_STRING;
5742 #if ENABLE_FEATURE_SH_MATH
5743 char arith_buf[sizeof(arith_t)*3 + 2];
5747 o_addchr(output, '\0');
5748 n = o_save_ptr(output, n);
5752 o_addblock(output, arg, p - arg);
5753 debug_print_list("expand_vars_to_list[1]", output, n);
5755 p = strchr(p, SPECIAL_VAR_SYMBOL);
5757 /* Fetch special var name (if it is indeed one of them)
5758 * and quote bit, force the bit on if singleword expansion -
5759 * important for not getting v=$@ expand to many words. */
5760 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5762 /* Is this variable quoted and thus expansion can't be null?
5763 * "$@" is special. Even if quoted, it can still
5764 * expand to nothing (not even an empty string),
5765 * thus it is excluded. */
5766 if ((first_ch & 0x7f) != '@')
5767 cant_be_null |= first_ch;
5769 switch (first_ch & 0x7f) {
5770 /* Highest bit in first_ch indicates that var is double-quoted */
5774 if (!G.global_argv[1])
5777 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5778 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5779 while (G.global_argv[i]) {
5780 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5781 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5782 if (G.global_argv[i++][0] && G.global_argv[i]) {
5783 /* this argv[] is not empty and not last:
5784 * put terminating NUL, start new word */
5785 o_addchr(output, '\0');
5786 debug_print_list("expand_vars_to_list[2]", output, n);
5787 n = o_save_ptr(output, n);
5788 debug_print_list("expand_vars_to_list[3]", output, n);
5792 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5793 * and in this case should treat it like '$*' - see 'else...' below */
5794 if (first_ch == ('@'|0x80) /* quoted $@ */
5795 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5798 o_addQstr(output, G.global_argv[i]);
5799 if (++i >= G.global_argc)
5801 o_addchr(output, '\0');
5802 debug_print_list("expand_vars_to_list[4]", output, n);
5803 n = o_save_ptr(output, n);
5805 } else { /* quoted $* (or v="$@" case): add as one word */
5807 o_addQstr(output, G.global_argv[i]);
5808 if (!G.global_argv[++i])
5811 o_addchr(output, G.ifs[0]);
5813 output->has_quoted_part = 1;
5817 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5818 /* "Empty variable", used to make "" etc to not disappear */
5819 output->has_quoted_part = 1;
5821 cant_be_null = 0x80;
5823 #if ENABLE_HUSH_TICK
5824 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5825 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5827 /* Can't just stuff it into output o_string,
5828 * expanded result may need to be globbed
5829 * and $IFS-splitted */
5830 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5831 G.last_exitcode = process_command_subs(&subst_result, arg);
5832 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5833 val = subst_result.data;
5836 #if ENABLE_FEATURE_SH_MATH
5837 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5840 arg++; /* skip '+' */
5841 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5842 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5843 res = expand_and_evaluate_arith(arg, NULL);
5844 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5845 sprintf(arith_buf, ARITH_FMT, res);
5851 val = expand_one_var(&to_be_freed, arg, &p);
5852 IF_HUSH_TICK(store_val:)
5853 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5854 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5855 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5856 if (val && val[0]) {
5857 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5860 } else { /* quoted $VAR, val will be appended below */
5861 output->has_quoted_part = 1;
5862 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5863 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5866 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5868 if (val && val[0]) {
5869 o_addQstr(output, val);
5873 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5874 * Do the check to avoid writing to a const string. */
5875 if (*p != SPECIAL_VAR_SYMBOL)
5876 *p = SPECIAL_VAR_SYMBOL;
5878 #if ENABLE_HUSH_TICK
5879 o_free(&subst_result);
5882 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5886 o_addchr(output, '\0');
5887 n = o_save_ptr(output, n);
5889 debug_print_list("expand_vars_to_list[a]", output, n);
5890 /* this part is literal, and it was already pre-quoted
5891 * if needed (much earlier), do not use o_addQstr here! */
5892 o_addstr_with_NUL(output, arg);
5893 debug_print_list("expand_vars_to_list[b]", output, n);
5894 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5895 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5898 /* allow to reuse list[n] later without re-growth */
5899 output->has_empty_slot = 1;
5901 o_addchr(output, '\0');
5907 static char **expand_variables(char **argv, unsigned expflags)
5911 o_string output = NULL_O_STRING;
5913 output.o_expflags = expflags;
5917 n = expand_vars_to_list(&output, n, *argv);
5920 debug_print_list("expand_variables", &output, n);
5922 /* output.data (malloced in one block) gets returned in "list" */
5923 list = o_finalize_list(&output, n);
5924 debug_print_strings("expand_variables[1]", list);
5928 static char **expand_strvec_to_strvec(char **argv)
5930 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5934 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5936 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5940 /* Used for expansion of right hand of assignments,
5941 * $((...)), heredocs, variable espansion parts.
5943 * NB: should NOT do globbing!
5944 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5946 static char *expand_string_to_string(const char *str, int do_unbackslash)
5948 #if !BASH_PATTERN_SUBST
5949 const int do_unbackslash = 1;
5951 char *argv[2], **list;
5953 debug_printf_expand("string_to_string<='%s'\n", str);
5954 /* This is generally an optimization, but it also
5955 * handles "", which otherwise trips over !list[0] check below.
5956 * (is this ever happens that we actually get str="" here?)
5958 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5959 //TODO: Can use on strings with \ too, just unbackslash() them?
5960 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5961 return xstrdup(str);
5964 argv[0] = (char*)str;
5966 list = expand_variables(argv, do_unbackslash
5967 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5968 : EXP_FLAG_SINGLEWORD
5971 if (!list[0] || list[1])
5972 bb_error_msg_and_die("BUG in varexp2");
5973 /* actually, just move string 2*sizeof(char*) bytes back */
5974 overlapping_strcpy((char*)list, list[0]);
5976 unbackslash((char*)list);
5977 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5981 /* Used for "eval" builtin */
5982 static char* expand_strvec_to_string(char **argv)
5986 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5987 /* Convert all NULs to spaces */
5992 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5993 bb_error_msg_and_die("BUG in varexp3");
5994 /* bash uses ' ' regardless of $IFS contents */
5999 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6000 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6004 static char **expand_assignments(char **argv, int count)
6009 G.expanded_assignments = p = NULL;
6010 /* Expand assignments into one string each */
6011 for (i = 0; i < count; i++) {
6012 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6014 G.expanded_assignments = NULL;
6019 static void switch_off_special_sigs(unsigned mask)
6022 while ((mask >>= 1) != 0) {
6026 #if ENABLE_HUSH_TRAP
6028 if (G_traps[sig] && !G_traps[sig][0])
6029 /* trap is '', has to remain SIG_IGN */
6032 G_traps[sig] = NULL;
6035 /* We are here only if no trap or trap was not '' */
6036 install_sighandler(sig, SIG_DFL);
6042 void re_execute_shell(char ***to_free, const char *s,
6043 char *g_argv0, char **g_argv,
6044 char **builtin_argv) NORETURN;
6046 static void reset_traps_to_defaults(void)
6048 /* This function is always called in a child shell
6049 * after fork (not vfork, NOMMU doesn't use this function).
6051 IF_HUSH_TRAP(unsigned sig;)
6054 /* Child shells are not interactive.
6055 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6056 * Testcase: (while :; do :; done) + ^Z should background.
6057 * Same goes for SIGTERM, SIGHUP, SIGINT.
6059 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6060 if (!G_traps && !mask)
6061 return; /* already no traps and no special sigs */
6063 /* Switch off special sigs */
6064 switch_off_special_sigs(mask);
6065 # if ENABLE_HUSH_JOB
6066 G_fatal_sig_mask = 0;
6068 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6069 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6070 * remain set in G.special_sig_mask */
6072 # if ENABLE_HUSH_TRAP
6076 /* Reset all sigs to default except ones with empty traps */
6077 for (sig = 0; sig < NSIG; sig++) {
6079 continue; /* no trap: nothing to do */
6080 if (!G_traps[sig][0])
6081 continue; /* empty trap: has to remain SIG_IGN */
6082 /* sig has non-empty trap, reset it: */
6084 G_traps[sig] = NULL;
6085 /* There is no signal for trap 0 (EXIT) */
6088 install_sighandler(sig, pick_sighandler(sig));
6095 static void re_execute_shell(char ***to_free, const char *s,
6096 char *g_argv0, char **g_argv,
6097 char **builtin_argv) NORETURN;
6098 static void re_execute_shell(char ***to_free, const char *s,
6099 char *g_argv0, char **g_argv,
6100 char **builtin_argv)
6102 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6103 /* delims + 2 * (number of bytes in printed hex numbers) */
6104 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6105 char *heredoc_argv[4];
6106 struct variable *cur;
6107 # if ENABLE_HUSH_FUNCTIONS
6108 struct function *funcp;
6112 unsigned long long empty_trap_mask;
6114 if (!g_argv0) { /* heredoc */
6115 argv = heredoc_argv;
6116 argv[0] = (char *) G.argv0_for_re_execing;
6117 argv[1] = (char *) "-<";
6118 argv[2] = (char *) s;
6120 pp = &argv[3]; /* used as pointer to empty environment */
6126 if (pp) while (*pp++)
6129 empty_trap_mask = 0;
6132 for (sig = 1; sig < NSIG; sig++) {
6133 if (G_traps[sig] && !G_traps[sig][0])
6134 empty_trap_mask |= 1LL << sig;
6138 sprintf(param_buf, NOMMU_HACK_FMT
6139 , (unsigned) G.root_pid
6140 , (unsigned) G.root_ppid
6141 , (unsigned) G.last_bg_pid
6142 , (unsigned) G.last_exitcode
6145 IF_HUSH_LOOPS(, G.depth_of_loop)
6147 # undef NOMMU_HACK_FMT
6148 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6149 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6152 for (cur = G.top_var; cur; cur = cur->next) {
6153 if (!cur->flg_export || cur->flg_read_only)
6156 # if ENABLE_HUSH_FUNCTIONS
6157 for (funcp = G.top_func; funcp; funcp = funcp->next)
6163 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6164 *pp++ = (char *) G.argv0_for_re_execing;
6166 for (cur = G.top_var; cur; cur = cur->next) {
6167 if (strcmp(cur->varstr, hush_version_str) == 0)
6169 if (cur->flg_read_only) {
6170 *pp++ = (char *) "-R";
6171 *pp++ = cur->varstr;
6172 } else if (!cur->flg_export) {
6173 *pp++ = (char *) "-V";
6174 *pp++ = cur->varstr;
6177 # if ENABLE_HUSH_FUNCTIONS
6178 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6179 *pp++ = (char *) "-F";
6180 *pp++ = funcp->name;
6181 *pp++ = funcp->body_as_string;
6184 /* We can pass activated traps here. Say, -Tnn:trap_string
6186 * However, POSIX says that subshells reset signals with traps
6188 * I tested bash-3.2 and it not only does that with true subshells
6189 * of the form ( list ), but with any forked children shells.
6190 * I set trap "echo W" WINCH; and then tried:
6192 * { echo 1; sleep 20; echo 2; } &
6193 * while true; do echo 1; sleep 20; echo 2; break; done &
6194 * true | { echo 1; sleep 20; echo 2; } | cat
6196 * In all these cases sending SIGWINCH to the child shell
6197 * did not run the trap. If I add trap "echo V" WINCH;
6198 * _inside_ group (just before echo 1), it works.
6200 * I conclude it means we don't need to pass active traps here.
6202 *pp++ = (char *) "-c";
6205 while (*++builtin_argv)
6206 *pp++ = *builtin_argv;
6207 *pp++ = (char *) "";
6212 /* *pp = NULL; - is already there */
6216 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6217 /* Don't propagate SIG_IGN to the child */
6218 if (SPECIAL_JOBSTOP_SIGS != 0)
6219 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6220 execve(bb_busybox_exec_path, argv, pp);
6221 /* Fallback. Useful for init=/bin/hush usage etc */
6222 if (argv[0][0] == '/')
6223 execve(argv[0], argv, pp);
6224 xfunc_error_retval = 127;
6225 bb_error_msg_and_die("can't re-execute the shell");
6227 #endif /* !BB_MMU */
6230 static int run_and_free_list(struct pipe *pi);
6232 /* Executing from string: eval, sh -c '...'
6233 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6234 * end_trigger controls how often we stop parsing
6235 * NUL: parse all, execute, return
6236 * ';': parse till ';' or newline, execute, repeat till EOF
6238 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6240 /* Why we need empty flag?
6241 * An obscure corner case "false; ``; echo $?":
6242 * empty command in `` should still set $? to 0.
6243 * But we can't just set $? to 0 at the start,
6244 * this breaks "false; echo `echo $?`" case.
6248 struct pipe *pipe_list;
6250 #if ENABLE_HUSH_INTERACTIVE
6251 if (end_trigger == ';')
6252 inp->promptmode = 0; /* PS1 */
6254 pipe_list = parse_stream(NULL, inp, end_trigger);
6255 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6256 /* If we are in "big" script
6257 * (not in `cmd` or something similar)...
6259 if (pipe_list == ERR_PTR && end_trigger == ';') {
6260 /* Discard cached input (rest of line) */
6261 int ch = inp->last_char;
6262 while (ch != EOF && ch != '\n') {
6263 //bb_error_msg("Discarded:'%c'", ch);
6268 /* This stream isn't empty */
6272 if (!pipe_list && empty)
6273 G.last_exitcode = 0;
6276 debug_print_tree(pipe_list, 0);
6277 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6278 run_and_free_list(pipe_list);
6280 if (G_flag_return_in_progress == 1)
6285 static void parse_and_run_string(const char *s)
6287 struct in_str input;
6288 setup_string_in_str(&input, s);
6289 parse_and_run_stream(&input, '\0');
6292 static void parse_and_run_file(FILE *f)
6294 struct in_str input;
6295 setup_file_in_str(&input, f);
6296 parse_and_run_stream(&input, ';');
6299 #if ENABLE_HUSH_TICK
6300 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6305 char **to_free = NULL;
6309 pid = BB_MMU ? xfork() : xvfork();
6310 if (pid == 0) { /* child */
6311 disable_restore_tty_pgrp_on_exit();
6312 /* Process substitution is not considered to be usual
6313 * 'command execution'.
6314 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6321 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6322 close(channel[0]); /* NB: close _first_, then move fd! */
6323 xmove_fd(channel[1], 1);
6324 /* Prevent it from trying to handle ctrl-z etc */
6325 IF_HUSH_JOB(G.run_list_level = 1;)
6326 # if ENABLE_HUSH_TRAP
6327 /* Awful hack for `trap` or $(trap).
6329 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6330 * contains an example where "trap" is executed in a subshell:
6332 * save_traps=$(trap)
6334 * eval "$save_traps"
6336 * Standard does not say that "trap" in subshell shall print
6337 * parent shell's traps. It only says that its output
6338 * must have suitable form, but then, in the above example
6339 * (which is not supposed to be normative), it implies that.
6341 * bash (and probably other shell) does implement it
6342 * (traps are reset to defaults, but "trap" still shows them),
6343 * but as a result, "trap" logic is hopelessly messed up:
6346 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6347 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6348 * # true | trap <--- trap is in subshell - no output (ditto)
6349 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6350 * trap -- 'echo Ho' SIGWINCH
6351 * # echo `(trap)` <--- in subshell in subshell - output
6352 * trap -- 'echo Ho' SIGWINCH
6353 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6354 * trap -- 'echo Ho' SIGWINCH
6356 * The rules when to forget and when to not forget traps
6357 * get really complex and nonsensical.
6359 * Our solution: ONLY bare $(trap) or `trap` is special.
6361 s = skip_whitespace(s);
6362 if (is_prefixed_with(s, "trap")
6363 && skip_whitespace(s + 4)[0] == '\0'
6365 static const char *const argv[] = { NULL, NULL };
6366 builtin_trap((char**)argv);
6367 fflush_all(); /* important */
6372 reset_traps_to_defaults();
6373 parse_and_run_string(s);
6374 _exit(G.last_exitcode);
6376 /* We re-execute after vfork on NOMMU. This makes this script safe:
6377 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6378 * huge=`cat BIG` # was blocking here forever
6381 re_execute_shell(&to_free,
6391 # if ENABLE_HUSH_FAST
6393 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6394 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6395 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6397 enable_restore_tty_pgrp_on_exit();
6402 return remember_FILE(xfdopen_for_read(channel[0]));
6405 /* Return code is exit status of the process that is run. */
6406 static int process_command_subs(o_string *dest, const char *s)
6409 struct in_str pipe_str;
6411 int status, ch, eol_cnt;
6413 fp = generate_stream_from_string(s, &pid);
6415 /* Now send results of command back into original context */
6416 setup_file_in_str(&pipe_str, fp);
6418 while ((ch = i_getch(&pipe_str)) != EOF) {
6424 o_addchr(dest, '\n');
6427 o_addQchr(dest, ch);
6430 debug_printf("done reading from `cmd` pipe, closing it\n");
6431 fclose_and_forget(fp);
6432 /* We need to extract exitcode. Test case
6433 * "true; echo `sleep 1; false` $?"
6435 safe_waitpid(pid, &status, 0);
6436 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6437 return WEXITSTATUS(status);
6439 #endif /* ENABLE_HUSH_TICK */
6442 static void setup_heredoc(struct redir_struct *redir)
6444 struct fd_pair pair;
6447 /* the _body_ of heredoc (misleading field name) */
6448 const char *heredoc = redir->rd_filename;
6455 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6456 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6460 len = strlen(heredoc);
6462 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6464 xmove_fd(pair.rd, redir->rd_fd);
6466 /* Try writing without forking. Newer kernels have
6467 * dynamically growing pipes. Must use non-blocking write! */
6470 written = write(pair.wr, heredoc, len);
6481 ndelay_off(pair.wr);
6483 /* Okay, pipe buffer was not big enough */
6484 /* Note: we must not create a stray child (bastard? :)
6485 * for the unsuspecting parent process. Child creates a grandchild
6486 * and exits before parent execs the process which consumes heredoc
6487 * (that exec happens after we return from this function) */
6494 disable_restore_tty_pgrp_on_exit();
6495 pid = BB_MMU ? xfork() : xvfork();
6499 close(redir->rd_fd); /* read side of the pipe */
6501 full_write(pair.wr, heredoc, len); /* may loop or block */
6504 /* Delegate blocking writes to another process */
6505 xmove_fd(pair.wr, STDOUT_FILENO);
6506 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6510 #if ENABLE_HUSH_FAST
6512 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6514 enable_restore_tty_pgrp_on_exit();
6520 wait(NULL); /* wait till child has died */
6523 /* fd: redirect wants this fd to be used (e.g. 3>file).
6524 * Move all conflicting internally used fds,
6525 * and remember them so that we can restore them later.
6527 static int save_fds_on_redirect(int fd, int squirrel[3])
6530 /* Handle redirects of fds 0,1,2 */
6532 /* If we collide with an already moved stdio fd... */
6533 if (fd == squirrel[0]) {
6534 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6537 if (fd == squirrel[1]) {
6538 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6541 if (fd == squirrel[2]) {
6542 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6545 /* If we are about to redirect stdio fd, and did not yet move it... */
6546 if (fd <= 2 && squirrel[fd] < 0) {
6547 /* We avoid taking stdio fds */
6548 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6549 if (squirrel[fd] < 0 && errno != EBADF)
6551 return 0; /* "we did not close fd" */
6555 #if ENABLE_HUSH_INTERACTIVE
6556 if (fd != 0 && fd == G.interactive_fd) {
6557 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6562 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6563 * (1) Redirect in a forked child. No need to save FILEs' fds,
6564 * we aren't going to use them anymore, ok to trash.
6565 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6566 * but how are we doing to use them?
6567 * "fileno(fd) = new_fd" can't be done.
6572 return save_FILEs_on_redirect(fd);
6575 static void restore_redirects(int squirrel[3])
6578 for (i = 0; i <= 2; i++) {
6581 /* We simply die on error */
6586 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6588 restore_redirected_FILEs();
6591 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6592 * and stderr if they are redirected. */
6593 static int setup_redirects(struct command *prog, int squirrel[])
6596 struct redir_struct *redir;
6598 for (redir = prog->redirects; redir; redir = redir->next) {
6599 if (redir->rd_type == REDIRECT_HEREDOC2) {
6600 /* "rd_fd<<HERE" case */
6601 save_fds_on_redirect(redir->rd_fd, squirrel);
6602 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6604 debug_printf_parse("set heredoc '%s'\n",
6605 redir->rd_filename);
6606 setup_heredoc(redir);
6610 if (redir->rd_dup == REDIRFD_TO_FILE) {
6611 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6613 if (redir->rd_filename == NULL) {
6616 * "cmd >" (no filename)
6617 * "cmd > <file" (2nd redirect starts too early)
6619 die_if_script("syntax error: %s", "invalid redirect");
6622 mode = redir_table[redir->rd_type].mode;
6623 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6624 openfd = open_or_warn(p, mode);
6627 /* Error message from open_or_warn can be lost
6628 * if stderr has been redirected, but bash
6629 * and ash both lose it as well
6630 * (though zsh doesn't!)
6635 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6636 openfd = redir->rd_dup;
6639 if (openfd != redir->rd_fd) {
6640 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6641 if (openfd == REDIRFD_CLOSE) {
6642 /* "rd_fd >&-" means "close me" */
6644 /* ^^^ optimization: saving may already
6645 * have closed it. If not... */
6646 close(redir->rd_fd);
6649 xdup2(openfd, redir->rd_fd);
6650 if (redir->rd_dup == REDIRFD_TO_FILE)
6651 /* "rd_fd > FILE" */
6653 /* else: "rd_fd > rd_dup" */
6660 static char *find_in_path(const char *arg)
6663 const char *PATH = get_local_var_value("PATH");
6669 const char *end = strchrnul(PATH, ':');
6670 int sz = end - PATH; /* must be int! */
6674 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6676 /* We have xxx::yyyy in $PATH,
6677 * it means "use current dir" */
6680 if (access(ret, F_OK) == 0)
6693 static const struct built_in_command *find_builtin_helper(const char *name,
6694 const struct built_in_command *x,
6695 const struct built_in_command *end)
6698 if (strcmp(name, x->b_cmd) != 0) {
6702 debug_printf_exec("found builtin '%s'\n", name);
6707 static const struct built_in_command *find_builtin1(const char *name)
6709 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6711 static const struct built_in_command *find_builtin(const char *name)
6713 const struct built_in_command *x = find_builtin1(name);
6716 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6719 #if ENABLE_HUSH_FUNCTIONS
6720 static struct function **find_function_slot(const char *name)
6722 struct function **funcpp = &G.top_func;
6724 if (strcmp(name, (*funcpp)->name) == 0) {
6727 funcpp = &(*funcpp)->next;
6732 static const struct function *find_function(const char *name)
6734 const struct function *funcp = *find_function_slot(name);
6736 debug_printf_exec("found function '%s'\n", name);
6740 /* Note: takes ownership on name ptr */
6741 static struct function *new_function(char *name)
6743 struct function **funcpp = find_function_slot(name);
6744 struct function *funcp = *funcpp;
6746 if (funcp != NULL) {
6747 struct command *cmd = funcp->parent_cmd;
6748 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6750 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6752 /* Note: if !funcp->body, do not free body_as_string!
6753 * This is a special case of "-F name body" function:
6754 * body_as_string was not malloced! */
6756 free_pipe_list(funcp->body);
6758 free(funcp->body_as_string);
6762 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6763 cmd->argv[0] = funcp->name;
6764 cmd->group = funcp->body;
6766 cmd->group_as_string = funcp->body_as_string;
6770 debug_printf_exec("remembering new function '%s'\n", name);
6771 funcp = *funcpp = xzalloc(sizeof(*funcp));
6772 /*funcp->next = NULL;*/
6779 # if ENABLE_HUSH_UNSET
6780 static void unset_func(const char *name)
6782 struct function **funcpp = find_function_slot(name);
6783 struct function *funcp = *funcpp;
6785 if (funcp != NULL) {
6786 debug_printf_exec("freeing function '%s'\n", funcp->name);
6787 *funcpp = funcp->next;
6788 /* funcp is unlinked now, deleting it.
6789 * Note: if !funcp->body, the function was created by
6790 * "-F name body", do not free ->body_as_string
6791 * and ->name as they were not malloced. */
6793 free_pipe_list(funcp->body);
6796 free(funcp->body_as_string);
6805 #define exec_function(to_free, funcp, argv) \
6806 exec_function(funcp, argv)
6808 static void exec_function(char ***to_free,
6809 const struct function *funcp,
6810 char **argv) NORETURN;
6811 static void exec_function(char ***to_free,
6812 const struct function *funcp,
6818 argv[0] = G.global_argv[0];
6819 G.global_argv = argv;
6823 /* On MMU, funcp->body is always non-NULL */
6824 n = run_list(funcp->body);
6828 re_execute_shell(to_free,
6829 funcp->body_as_string,
6836 static int run_function(const struct function *funcp, char **argv)
6842 save_and_replace_G_args(&sv, argv);
6844 /* "we are in function, ok to use return" */
6845 sv_flg = G_flag_return_in_progress;
6846 G_flag_return_in_progress = -1;
6847 # if ENABLE_HUSH_LOCAL
6848 G.func_nest_level++;
6851 /* On MMU, funcp->body is always non-NULL */
6854 /* Function defined by -F */
6855 parse_and_run_string(funcp->body_as_string);
6856 rc = G.last_exitcode;
6860 rc = run_list(funcp->body);
6863 # if ENABLE_HUSH_LOCAL
6865 struct variable *var;
6866 struct variable **var_pp;
6868 var_pp = &G.top_var;
6869 while ((var = *var_pp) != NULL) {
6870 if (var->func_nest_level < G.func_nest_level) {
6871 var_pp = &var->next;
6875 if (var->flg_export)
6876 bb_unsetenv(var->varstr);
6877 /* Remove from global list */
6878 *var_pp = var->next;
6884 G.func_nest_level--;
6887 G_flag_return_in_progress = sv_flg;
6889 restore_G_args(&sv, argv);
6893 #endif /* ENABLE_HUSH_FUNCTIONS */
6897 #define exec_builtin(to_free, x, argv) \
6898 exec_builtin(x, argv)
6900 #define exec_builtin(to_free, x, argv) \
6901 exec_builtin(to_free, argv)
6903 static void exec_builtin(char ***to_free,
6904 const struct built_in_command *x,
6905 char **argv) NORETURN;
6906 static void exec_builtin(char ***to_free,
6907 const struct built_in_command *x,
6913 rcode = x->b_function(argv);
6918 /* On NOMMU, we must never block!
6919 * Example: { sleep 99 | read line; } & echo Ok
6921 re_execute_shell(to_free,
6930 static void execvp_or_die(char **argv) NORETURN;
6931 static void execvp_or_die(char **argv)
6934 debug_printf_exec("execing '%s'\n", argv[0]);
6935 /* Don't propagate SIG_IGN to the child */
6936 if (SPECIAL_JOBSTOP_SIGS != 0)
6937 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6938 execvp(argv[0], argv);
6940 if (errno == EACCES) e = 126;
6941 if (errno == ENOENT) e = 127;
6942 bb_perror_msg("can't execute '%s'", argv[0]);
6946 #if ENABLE_HUSH_MODE_X
6947 static void dump_cmd_in_x_mode(char **argv)
6949 if (G_x_mode && argv) {
6950 /* We want to output the line in one write op */
6958 len += strlen(argv[n++]) + 1;
6964 p += sprintf(p, " %s", argv[n++]);
6972 # define dump_cmd_in_x_mode(argv) ((void)0)
6976 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6977 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6978 #define pseudo_exec(nommu_save, command, argv_expanded) \
6979 pseudo_exec(command, argv_expanded)
6982 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6984 * Don't exit() here. If you don't exec, use _exit instead.
6985 * The at_exit handlers apparently confuse the calling process,
6986 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6988 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6989 char **argv, int assignment_cnt,
6990 char **argv_expanded) NORETURN;
6991 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6992 char **argv, int assignment_cnt,
6993 char **argv_expanded)
6997 new_env = expand_assignments(argv, assignment_cnt);
6998 dump_cmd_in_x_mode(new_env);
7000 if (!argv[assignment_cnt]) {
7001 /* Case when we are here: ... | var=val | ...
7002 * (note that we do not exit early, i.e., do not optimize out
7003 * expand_assignments(): think about ... | var=`sleep 1` | ...
7005 free_strings(new_env);
7006 _exit(EXIT_SUCCESS);
7010 set_vars_and_save_old(new_env);
7011 free(new_env); /* optional */
7012 /* we can also destroy set_vars_and_save_old's return value,
7015 nommu_save->new_env = new_env;
7016 nommu_save->old_vars = set_vars_and_save_old(new_env);
7019 if (argv_expanded) {
7020 argv = argv_expanded;
7022 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7024 nommu_save->argv = argv;
7027 dump_cmd_in_x_mode(argv);
7029 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7030 if (strchr(argv[0], '/') != NULL)
7034 /* Check if the command matches any of the builtins.
7035 * Depending on context, this might be redundant. But it's
7036 * easier to waste a few CPU cycles than it is to figure out
7037 * if this is one of those cases.
7040 /* On NOMMU, it is more expensive to re-execute shell
7041 * just in order to run echo or test builtin.
7042 * It's better to skip it here and run corresponding
7043 * non-builtin later. */
7044 const struct built_in_command *x;
7045 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7047 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7050 #if ENABLE_HUSH_FUNCTIONS
7051 /* Check if the command matches any functions */
7053 const struct function *funcp = find_function(argv[0]);
7055 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7060 #if ENABLE_FEATURE_SH_STANDALONE
7061 /* Check if the command matches any busybox applets */
7063 int a = find_applet_by_name(argv[0]);
7065 # if BB_MMU /* see above why on NOMMU it is not allowed */
7066 if (APPLET_IS_NOEXEC(a)) {
7067 /* Do not leak open fds from opened script files etc */
7068 close_all_FILE_list();
7069 debug_printf_exec("running applet '%s'\n", argv[0]);
7070 run_applet_no_and_exit(a, argv);
7073 /* Re-exec ourselves */
7074 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7075 /* Don't propagate SIG_IGN to the child */
7076 if (SPECIAL_JOBSTOP_SIGS != 0)
7077 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7078 execv(bb_busybox_exec_path, argv);
7079 /* If they called chroot or otherwise made the binary no longer
7080 * executable, fall through */
7085 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7088 execvp_or_die(argv);
7091 /* Called after [v]fork() in run_pipe
7093 static void pseudo_exec(nommu_save_t *nommu_save,
7094 struct command *command,
7095 char **argv_expanded) NORETURN;
7096 static void pseudo_exec(nommu_save_t *nommu_save,
7097 struct command *command,
7098 char **argv_expanded)
7100 if (command->argv) {
7101 pseudo_exec_argv(nommu_save, command->argv,
7102 command->assignment_cnt, argv_expanded);
7105 if (command->group) {
7106 /* Cases when we are here:
7109 * ... | ( list ) | ...
7110 * ... | { list } | ...
7114 debug_printf_exec("pseudo_exec: run_list\n");
7115 reset_traps_to_defaults();
7116 rcode = run_list(command->group);
7117 /* OK to leak memory by not calling free_pipe_list,
7118 * since this process is about to exit */
7121 re_execute_shell(&nommu_save->argv_from_re_execing,
7122 command->group_as_string,
7129 /* Case when we are here: ... | >file */
7130 debug_printf_exec("pseudo_exec'ed null command\n");
7131 _exit(EXIT_SUCCESS);
7135 static const char *get_cmdtext(struct pipe *pi)
7141 /* This is subtle. ->cmdtext is created only on first backgrounding.
7142 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7143 * On subsequent bg argv is trashed, but we won't use it */
7147 argv = pi->cmds[0].argv;
7149 pi->cmdtext = xzalloc(1);
7154 len += strlen(*argv) + 1;
7158 argv = pi->cmds[0].argv;
7160 p = stpcpy(p, *argv);
7167 static void insert_bg_job(struct pipe *pi)
7169 struct pipe *job, **jobp;
7172 /* Linear search for the ID of the job to use */
7174 for (job = G.job_list; job; job = job->next)
7175 if (job->jobid >= pi->jobid)
7176 pi->jobid = job->jobid + 1;
7178 /* Add job to the list of running jobs */
7180 while ((job = *jobp) != NULL)
7182 job = *jobp = xmalloc(sizeof(*job));
7184 *job = *pi; /* physical copy */
7186 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7187 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7188 for (i = 0; i < pi->num_cmds; i++) {
7189 job->cmds[i].pid = pi->cmds[i].pid;
7190 /* all other fields are not used and stay zero */
7192 job->cmdtext = xstrdup(get_cmdtext(pi));
7194 if (G_interactive_fd)
7195 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7196 G.last_jobid = job->jobid;
7199 static void remove_bg_job(struct pipe *pi)
7201 struct pipe *prev_pipe;
7203 if (pi == G.job_list) {
7204 G.job_list = pi->next;
7206 prev_pipe = G.job_list;
7207 while (prev_pipe->next != pi)
7208 prev_pipe = prev_pipe->next;
7209 prev_pipe->next = pi->next;
7212 G.last_jobid = G.job_list->jobid;
7217 /* Remove a backgrounded job */
7218 static void delete_finished_bg_job(struct pipe *pi)
7225 static int job_exited_or_stopped(struct pipe *pi)
7229 if (pi->alive_cmds != pi->stopped_cmds)
7232 /* All processes in fg pipe have exited or stopped */
7236 rcode = pi->cmds[i].cmd_exitcode;
7237 /* usually last process gives overall exitstatus,
7238 * but with "set -o pipefail", last *failed* process does */
7239 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7242 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7246 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7253 dead = WIFEXITED(status) || WIFSIGNALED(status);
7256 if (WIFSTOPPED(status))
7257 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7258 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7259 if (WIFSIGNALED(status))
7260 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7261 childpid, WTERMSIG(status), WEXITSTATUS(status));
7262 if (WIFEXITED(status))
7263 debug_printf_jobs("pid %d exited, exitcode %d\n",
7264 childpid, WEXITSTATUS(status));
7266 /* Were we asked to wait for a fg pipe? */
7268 i = fg_pipe->num_cmds;
7273 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7274 if (fg_pipe->cmds[i].pid != childpid)
7278 fg_pipe->cmds[i].pid = 0;
7279 fg_pipe->alive_cmds--;
7280 ex = WEXITSTATUS(status);
7281 /* bash prints killer signal's name for *last*
7282 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7283 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7285 if (WIFSIGNALED(status)) {
7286 int sig = WTERMSIG(status);
7287 if (i == fg_pipe->num_cmds-1)
7288 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7289 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7290 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7291 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7292 * Maybe we need to use sig | 128? */
7295 fg_pipe->cmds[i].cmd_exitcode = ex;
7297 fg_pipe->stopped_cmds++;
7299 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7300 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7301 rcode = job_exited_or_stopped(fg_pipe);
7303 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7304 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7305 * and "killall -STOP cat" */
7306 if (G_interactive_fd) {
7308 if (fg_pipe->alive_cmds != 0)
7309 insert_bg_job(fg_pipe);
7313 if (fg_pipe->alive_cmds == 0)
7316 /* There are still running processes in the fg_pipe */
7319 /* It wasnt in fg_pipe, look for process in bg pipes */
7323 /* We were asked to wait for bg or orphaned children */
7324 /* No need to remember exitcode in this case */
7325 for (pi = G.job_list; pi; pi = pi->next) {
7326 for (i = 0; i < pi->num_cmds; i++) {
7327 if (pi->cmds[i].pid == childpid)
7328 goto found_pi_and_prognum;
7331 /* Happens when shell is used as init process (init=/bin/sh) */
7332 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7333 return -1; /* this wasn't a process from fg_pipe */
7335 found_pi_and_prognum:
7338 pi->cmds[i].pid = 0;
7339 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7340 if (WIFSIGNALED(status))
7341 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7343 if (!pi->alive_cmds) {
7344 if (G_interactive_fd)
7345 printf(JOB_STATUS_FORMAT, pi->jobid,
7346 "Done", pi->cmdtext);
7347 delete_finished_bg_job(pi);
7354 return -1; /* this wasn't a process from fg_pipe */
7357 /* Check to see if any processes have exited -- if they have,
7358 * figure out why and see if a job has completed.
7360 * If non-NULL fg_pipe: wait for its completion or stop.
7361 * Return its exitcode or zero if stopped.
7363 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7364 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7365 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7366 * or 0 if no children changed status.
7368 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7369 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7370 * or 0 if no children changed status.
7372 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7378 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7380 attributes = WUNTRACED;
7381 if (fg_pipe == NULL)
7382 attributes |= WNOHANG;
7385 #if ENABLE_HUSH_FAST
7386 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7387 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7388 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7389 /* There was neither fork nor SIGCHLD since last waitpid */
7390 /* Avoid doing waitpid syscall if possible */
7391 if (!G.we_have_children) {
7395 if (fg_pipe == NULL) { /* is WNOHANG set? */
7396 /* We have children, but they did not exit
7397 * or stop yet (we saw no SIGCHLD) */
7400 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7404 /* Do we do this right?
7405 * bash-3.00# sleep 20 | false
7407 * [3]+ Stopped sleep 20 | false
7408 * bash-3.00# echo $?
7409 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7410 * [hush 1.14.0: yes we do it right]
7414 #if ENABLE_HUSH_FAST
7416 i = G.count_SIGCHLD;
7418 childpid = waitpid(-1, &status, attributes);
7419 if (childpid <= 0) {
7420 if (childpid && errno != ECHILD)
7421 bb_perror_msg("waitpid");
7422 #if ENABLE_HUSH_FAST
7423 else { /* Until next SIGCHLD, waitpid's are useless */
7424 G.we_have_children = (childpid == 0);
7425 G.handled_SIGCHLD = i;
7426 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7429 /* ECHILD (no children), or 0 (no change in children status) */
7433 rcode = process_wait_result(fg_pipe, childpid, status);
7435 /* fg_pipe exited or stopped */
7438 if (childpid == waitfor_pid) {
7439 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7440 rcode = WEXITSTATUS(status);
7441 if (WIFSIGNALED(status))
7442 rcode = 128 + WTERMSIG(status);
7443 if (WIFSTOPPED(status))
7444 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7445 rcode = 128 + WSTOPSIG(status);
7447 break; /* "wait PID" called us, give it exitcode+1 */
7449 /* This wasn't one of our processes, or */
7450 /* fg_pipe still has running processes, do waitpid again */
7451 } /* while (waitpid succeeds)... */
7457 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7460 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7461 if (G_saved_tty_pgrp) {
7462 /* Job finished, move the shell to the foreground */
7463 p = getpgrp(); /* our process group id */
7464 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7465 tcsetpgrp(G_interactive_fd, p);
7471 /* Start all the jobs, but don't wait for anything to finish.
7474 * Return code is normally -1, when the caller has to wait for children
7475 * to finish to determine the exit status of the pipe. If the pipe
7476 * is a simple builtin command, however, the action is done by the
7477 * time run_pipe returns, and the exit code is provided as the
7480 * Returns -1 only if started some children. IOW: we have to
7481 * mask out retvals of builtins etc with 0xff!
7483 * The only case when we do not need to [v]fork is when the pipe
7484 * is single, non-backgrounded, non-subshell command. Examples:
7485 * cmd ; ... { list } ; ...
7486 * cmd && ... { list } && ...
7487 * cmd || ... { list } || ...
7488 * If it is, then we can run cmd as a builtin, NOFORK,
7489 * or (if SH_STANDALONE) an applet, and we can run the { list }
7490 * with run_list. If it isn't one of these, we fork and exec cmd.
7492 * Cases when we must fork:
7493 * non-single: cmd | cmd
7494 * backgrounded: cmd & { list } &
7495 * subshell: ( list ) [&]
7497 #if !ENABLE_HUSH_MODE_X
7498 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7499 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7501 static int redirect_and_varexp_helper(char ***new_env_p,
7502 struct variable **old_vars_p,
7503 struct command *command,
7505 char **argv_expanded)
7507 /* setup_redirects acts on file descriptors, not FILEs.
7508 * This is perfect for work that comes after exec().
7509 * Is it really safe for inline use? Experimentally,
7510 * things seem to work. */
7511 int rcode = setup_redirects(command, squirrel);
7513 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7514 *new_env_p = new_env;
7515 dump_cmd_in_x_mode(new_env);
7516 dump_cmd_in_x_mode(argv_expanded);
7518 *old_vars_p = set_vars_and_save_old(new_env);
7522 static NOINLINE int run_pipe(struct pipe *pi)
7524 static const char *const null_ptr = NULL;
7528 struct command *command;
7529 char **argv_expanded;
7531 /* it is not always needed, but we aim to smaller code */
7532 int squirrel[] = { -1, -1, -1 };
7535 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7538 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7539 * Result should be 3 lines: q w e, qwe, q w e
7541 G.ifs = get_local_var_value("IFS");
7545 IF_HUSH_JOB(pi->pgrp = -1;)
7546 pi->stopped_cmds = 0;
7547 command = &pi->cmds[0];
7548 argv_expanded = NULL;
7550 if (pi->num_cmds != 1
7551 || pi->followup == PIPE_BG
7552 || command->cmd_type == CMD_SUBSHELL
7559 debug_printf_exec(": group:%p argv:'%s'\n",
7560 command->group, command->argv ? command->argv[0] : "NONE");
7562 if (command->group) {
7563 #if ENABLE_HUSH_FUNCTIONS
7564 if (command->cmd_type == CMD_FUNCDEF) {
7565 /* "executing" func () { list } */
7566 struct function *funcp;
7568 funcp = new_function(command->argv[0]);
7569 /* funcp->name is already set to argv[0] */
7570 funcp->body = command->group;
7572 funcp->body_as_string = command->group_as_string;
7573 command->group_as_string = NULL;
7575 command->group = NULL;
7576 command->argv[0] = NULL;
7577 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7578 funcp->parent_cmd = command;
7579 command->child_func = funcp;
7581 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7583 return EXIT_SUCCESS;
7587 debug_printf("non-subshell group\n");
7588 rcode = 1; /* exitcode if redir failed */
7589 if (setup_redirects(command, squirrel) == 0) {
7590 debug_printf_exec(": run_list\n");
7591 rcode = run_list(command->group) & 0xff;
7593 restore_redirects(squirrel);
7594 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7596 debug_printf_exec("run_pipe: return %d\n", rcode);
7600 argv = command->argv ? command->argv : (char **) &null_ptr;
7602 const struct built_in_command *x;
7603 #if ENABLE_HUSH_FUNCTIONS
7604 const struct function *funcp;
7608 char **new_env = NULL;
7609 struct variable *old_vars = NULL;
7611 if (argv[command->assignment_cnt] == NULL) {
7612 /* Assignments, but no command */
7613 /* Ensure redirects take effect (that is, create files).
7614 * Try "a=t >file" */
7615 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7616 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7617 /* Set shell variables */
7621 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7622 /* Do we need to flag set_local_var() errors?
7623 * "assignment to readonly var" and "putenv error"
7628 /* Redirect error sets $? to 1. Otherwise,
7629 * if evaluating assignment value set $?, retain it.
7630 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7632 rcode = G.last_exitcode;
7633 /* Exit, _skipping_ variable restoring code: */
7634 goto clean_up_and_ret0;
7636 #else /* Older, bigger, but more correct code */
7638 rcode = setup_redirects(command, squirrel);
7639 restore_redirects(squirrel);
7640 /* Set shell variables */
7642 bb_putchar_stderr('+');
7644 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7646 fprintf(stderr, " %s", p);
7647 debug_printf_exec("set shell var:'%s'->'%s'\n",
7649 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7650 /* Do we need to flag set_local_var() errors?
7651 * "assignment to readonly var" and "putenv error"
7656 bb_putchar_stderr('\n');
7657 /* Redirect error sets $? to 1. Otherwise,
7658 * if evaluating assignment value set $?, retain it.
7659 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7661 rcode = G.last_exitcode;
7662 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7664 debug_printf_exec("run_pipe: return %d\n", rcode);
7669 /* Expand the rest into (possibly) many strings each */
7671 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7672 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7676 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7679 /* if someone gives us an empty string: `cmd with empty output` */
7680 if (!argv_expanded[0]) {
7681 free(argv_expanded);
7683 return G.last_exitcode;
7686 x = find_builtin(argv_expanded[0]);
7687 #if ENABLE_HUSH_FUNCTIONS
7690 funcp = find_function(argv_expanded[0]);
7694 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7695 debug_printf("exec with redirects only\n");
7696 rcode = setup_redirects(command, NULL);
7697 /* rcode=1 can be if redir file can't be opened */
7698 goto clean_up_and_ret1;
7701 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7704 debug_printf_exec(": builtin '%s' '%s'...\n",
7705 x->b_cmd, argv_expanded[1]);
7707 rcode = x->b_function(argv_expanded) & 0xff;
7710 #if ENABLE_HUSH_FUNCTIONS
7712 # if ENABLE_HUSH_LOCAL
7713 struct variable **sv;
7714 sv = G.shadowed_vars_pp;
7715 G.shadowed_vars_pp = &old_vars;
7717 debug_printf_exec(": function '%s' '%s'...\n",
7718 funcp->name, argv_expanded[1]);
7719 rcode = run_function(funcp, argv_expanded) & 0xff;
7720 # if ENABLE_HUSH_LOCAL
7721 G.shadowed_vars_pp = sv;
7727 unset_vars(new_env);
7729 /* clean_up_and_ret0: */
7730 restore_redirects(squirrel);
7732 free(argv_expanded);
7733 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7735 debug_printf_exec("run_pipe return %d\n", rcode);
7739 if (ENABLE_FEATURE_SH_NOFORK) {
7740 int n = find_applet_by_name(argv_expanded[0]);
7741 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7742 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7744 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7745 argv_expanded[0], argv_expanded[1]);
7746 rcode = run_nofork_applet(n, argv_expanded);
7748 goto clean_up_and_ret;
7751 /* It is neither builtin nor applet. We must fork. */
7755 /* NB: argv_expanded may already be created, and that
7756 * might include `cmd` runs! Do not rerun it! We *must*
7757 * use argv_expanded if it's non-NULL */
7759 /* Going to fork a child per each pipe member */
7764 while (cmd_no < pi->num_cmds) {
7765 struct fd_pair pipefds;
7767 volatile nommu_save_t nommu_save;
7768 nommu_save.new_env = NULL;
7769 nommu_save.old_vars = NULL;
7770 nommu_save.argv = NULL;
7771 nommu_save.argv_from_re_execing = NULL;
7773 command = &pi->cmds[cmd_no];
7775 if (command->argv) {
7776 debug_printf_exec(": pipe member '%s' '%s'...\n",
7777 command->argv[0], command->argv[1]);
7779 debug_printf_exec(": pipe member with no argv\n");
7782 /* pipes are inserted between pairs of commands */
7785 if (cmd_no < pi->num_cmds)
7786 xpiped_pair(pipefds);
7788 command->pid = BB_MMU ? fork() : vfork();
7789 if (!command->pid) { /* child */
7791 disable_restore_tty_pgrp_on_exit();
7792 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7794 /* Every child adds itself to new process group
7795 * with pgid == pid_of_first_child_in_pipe */
7796 if (G.run_list_level == 1 && G_interactive_fd) {
7799 if (pgrp < 0) /* true for 1st process only */
7801 if (setpgid(0, pgrp) == 0
7802 && pi->followup != PIPE_BG
7803 && G_saved_tty_pgrp /* we have ctty */
7805 /* We do it in *every* child, not just first,
7807 tcsetpgrp(G_interactive_fd, pgrp);
7811 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7812 /* 1st cmd in backgrounded pipe
7813 * should have its stdin /dev/null'ed */
7815 if (open(bb_dev_null, O_RDONLY))
7816 xopen("/", O_RDONLY);
7818 xmove_fd(next_infd, 0);
7820 xmove_fd(pipefds.wr, 1);
7823 /* Like bash, explicit redirects override pipes,
7824 * and the pipe fd (fd#1) is available for dup'ing:
7825 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7826 * of cmd1 goes into pipe.
7828 if (setup_redirects(command, NULL)) {
7829 /* Happens when redir file can't be opened:
7830 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7832 * hush: can't open '/qwe/rty': No such file or directory
7834 * (echo BAR is not executed, it hits _exit(1) below)
7839 /* Stores to nommu_save list of env vars putenv'ed
7840 * (NOMMU, on MMU we don't need that) */
7841 /* cast away volatility... */
7842 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7843 /* pseudo_exec() does not return */
7846 /* parent or error */
7847 #if ENABLE_HUSH_FAST
7849 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7851 enable_restore_tty_pgrp_on_exit();
7853 /* Clean up after vforked child */
7854 free(nommu_save.argv);
7855 free(nommu_save.argv_from_re_execing);
7856 unset_vars(nommu_save.new_env);
7857 add_vars(nommu_save.old_vars);
7859 free(argv_expanded);
7860 argv_expanded = NULL;
7861 if (command->pid < 0) { /* [v]fork failed */
7862 /* Clearly indicate, was it fork or vfork */
7863 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7867 /* Second and next children need to know pid of first one */
7869 pi->pgrp = command->pid;
7875 if (cmd_no < pi->num_cmds)
7877 /* Pass read (output) pipe end to next iteration */
7878 next_infd = pipefds.rd;
7881 if (!pi->alive_cmds) {
7883 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7888 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7892 /* NB: called by pseudo_exec, and therefore must not modify any
7893 * global data until exec/_exit (we can be a child after vfork!) */
7894 static int run_list(struct pipe *pi)
7896 #if ENABLE_HUSH_CASE
7897 char *case_word = NULL;
7899 #if ENABLE_HUSH_LOOPS
7900 struct pipe *loop_top = NULL;
7901 char **for_lcur = NULL;
7902 char **for_list = NULL;
7904 smallint last_followup;
7906 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7907 smalluint cond_code = 0;
7909 enum { cond_code = 0 };
7912 smallint rword; /* RES_foo */
7913 smallint last_rword; /* ditto */
7916 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7919 #if ENABLE_HUSH_LOOPS
7920 /* Check syntax for "for" */
7923 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7924 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7926 /* current word is FOR or IN (BOLD in comments below) */
7927 if (cpipe->next == NULL) {
7928 syntax_error("malformed for");
7930 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7933 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7934 if (cpipe->next->res_word == RES_DO)
7936 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7937 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7938 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7940 syntax_error("malformed for");
7942 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7949 /* Past this point, all code paths should jump to ret: label
7950 * in order to return, no direct "return" statements please.
7951 * This helps to ensure that no memory is leaked. */
7959 last_rword = RES_XXXX;
7961 last_followup = PIPE_SEQ;
7962 rcode = G.last_exitcode;
7964 /* Go through list of pipes, (maybe) executing them. */
7965 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7970 if (G_flag_return_in_progress == 1)
7973 IF_HAS_KEYWORDS(rword = pi->res_word;)
7974 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7975 rword, cond_code, last_rword);
7976 #if ENABLE_HUSH_LOOPS
7977 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7978 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7980 /* start of a loop: remember where loop starts */
7985 /* Still in the same "if...", "then..." or "do..." branch? */
7986 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7987 if ((rcode == 0 && last_followup == PIPE_OR)
7988 || (rcode != 0 && last_followup == PIPE_AND)
7990 /* It is "<true> || CMD" or "<false> && CMD"
7991 * and we should not execute CMD */
7992 debug_printf_exec("skipped cmd because of || or &&\n");
7993 last_followup = pi->followup;
7994 goto dont_check_jobs_but_continue;
7997 last_followup = pi->followup;
7998 IF_HAS_KEYWORDS(last_rword = rword;)
8001 if (rword == RES_THEN) {
8002 /* if false; then ... fi has exitcode 0! */
8003 G.last_exitcode = rcode = EXIT_SUCCESS;
8004 /* "if <false> THEN cmd": skip cmd */
8008 if (rword == RES_ELSE || rword == RES_ELIF) {
8009 /* "if <true> then ... ELSE/ELIF cmd":
8010 * skip cmd and all following ones */
8015 #if ENABLE_HUSH_LOOPS
8016 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8018 /* first loop through for */
8020 static const char encoded_dollar_at[] ALIGN1 = {
8021 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8022 }; /* encoded representation of "$@" */
8023 static const char *const encoded_dollar_at_argv[] = {
8024 encoded_dollar_at, NULL
8025 }; /* argv list with one element: "$@" */
8028 vals = (char**)encoded_dollar_at_argv;
8029 if (pi->next->res_word == RES_IN) {
8030 /* if no variable values after "in" we skip "for" */
8031 if (!pi->next->cmds[0].argv) {
8032 G.last_exitcode = rcode = EXIT_SUCCESS;
8033 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8036 vals = pi->next->cmds[0].argv;
8037 } /* else: "for var; do..." -> assume "$@" list */
8038 /* create list of variable values */
8039 debug_print_strings("for_list made from", vals);
8040 for_list = expand_strvec_to_strvec(vals);
8041 for_lcur = for_list;
8042 debug_print_strings("for_list", for_list);
8045 /* "for" loop is over, clean up */
8051 /* Insert next value from for_lcur */
8052 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8053 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
8056 if (rword == RES_IN) {
8057 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8059 if (rword == RES_DONE) {
8060 continue; /* "done" has no cmds too */
8063 #if ENABLE_HUSH_CASE
8064 if (rword == RES_CASE) {
8065 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8066 case_word = expand_strvec_to_string(pi->cmds->argv);
8069 if (rword == RES_MATCH) {
8072 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8073 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8075 /* all prev words didn't match, does this one match? */
8076 argv = pi->cmds->argv;
8078 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
8079 /* TODO: which FNM_xxx flags to use? */
8080 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8082 if (cond_code == 0) { /* match! we will execute this branch */
8084 case_word = NULL; /* make future "word)" stop */
8091 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8092 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8094 continue; /* not matched yet, skip this pipe */
8096 if (rword == RES_ESAC) {
8097 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8099 /* "case" did not match anything: still set $? (to 0) */
8100 G.last_exitcode = rcode = EXIT_SUCCESS;
8104 /* Just pressing <enter> in shell should check for jobs.
8105 * OTOH, in non-interactive shell this is useless
8106 * and only leads to extra job checks */
8107 if (pi->num_cmds == 0) {
8108 if (G_interactive_fd)
8109 goto check_jobs_and_continue;
8113 /* After analyzing all keywords and conditions, we decided
8114 * to execute this pipe. NB: have to do checkjobs(NULL)
8115 * after run_pipe to collect any background children,
8116 * even if list execution is to be stopped. */
8117 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8118 #if ENABLE_HUSH_LOOPS
8119 G.flag_break_continue = 0;
8121 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8123 /* We ran a builtin, function, or group.
8124 * rcode is already known
8125 * and we don't need to wait for anything. */
8126 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8127 G.last_exitcode = rcode;
8128 check_and_run_traps();
8129 #if ENABLE_HUSH_LOOPS
8130 /* Was it "break" or "continue"? */
8131 if (G.flag_break_continue) {
8132 smallint fbc = G.flag_break_continue;
8133 /* We might fall into outer *loop*,
8134 * don't want to break it too */
8136 G.depth_break_continue--;
8137 if (G.depth_break_continue == 0)
8138 G.flag_break_continue = 0;
8139 /* else: e.g. "continue 2" should *break* once, *then* continue */
8140 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8141 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8142 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8145 /* "continue": simulate end of loop */
8150 if (G_flag_return_in_progress == 1) {
8151 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8154 } else if (pi->followup == PIPE_BG) {
8155 /* What does bash do with attempts to background builtins? */
8156 /* even bash 3.2 doesn't do that well with nested bg:
8157 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8158 * I'm NOT treating inner &'s as jobs */
8160 if (G.run_list_level == 1)
8163 /* Last command's pid goes to $! */
8164 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8165 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8166 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8167 rcode = EXIT_SUCCESS;
8171 if (G.run_list_level == 1 && G_interactive_fd) {
8172 /* Waits for completion, then fg's main shell */
8173 rcode = checkjobs_and_fg_shell(pi);
8174 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8178 /* This one just waits for completion */
8179 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8180 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8182 G.last_exitcode = rcode;
8183 check_and_run_traps();
8186 /* Analyze how result affects subsequent commands */
8188 if (rword == RES_IF || rword == RES_ELIF)
8191 check_jobs_and_continue:
8192 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8193 dont_check_jobs_but_continue: ;
8194 #if ENABLE_HUSH_LOOPS
8195 /* Beware of "while false; true; do ..."! */
8197 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8198 /* check for RES_DONE is needed for "while ...; do \n done" case */
8200 if (rword == RES_WHILE) {
8202 /* "while false; do...done" - exitcode 0 */
8203 G.last_exitcode = rcode = EXIT_SUCCESS;
8204 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8208 if (rword == RES_UNTIL) {
8210 debug_printf_exec(": until expr is true: breaking\n");
8221 #if ENABLE_HUSH_LOOPS
8226 #if ENABLE_HUSH_CASE
8230 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8234 /* Select which version we will use */
8235 static int run_and_free_list(struct pipe *pi)
8238 debug_printf_exec("run_and_free_list entered\n");
8239 if (!G.o_opt[OPT_O_NOEXEC]) {
8240 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8241 rcode = run_list(pi);
8243 /* free_pipe_list has the side effect of clearing memory.
8244 * In the long run that function can be merged with run_list,
8245 * but doing that now would hobble the debugging effort. */
8247 debug_printf_exec("run_and_free_list return %d\n", rcode);
8252 static void install_sighandlers(unsigned mask)
8254 sighandler_t old_handler;
8256 while ((mask >>= 1) != 0) {
8260 old_handler = install_sighandler(sig, pick_sighandler(sig));
8261 /* POSIX allows shell to re-enable SIGCHLD
8262 * even if it was SIG_IGN on entry.
8263 * Therefore we skip IGN check for it:
8267 if (old_handler == SIG_IGN) {
8268 /* oops... restore back to IGN, and record this fact */
8269 install_sighandler(sig, old_handler);
8270 #if ENABLE_HUSH_TRAP
8272 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8274 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8280 /* Called a few times only (or even once if "sh -c") */
8281 static void install_special_sighandlers(void)
8285 /* Which signals are shell-special? */
8286 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8287 if (G_interactive_fd) {
8288 mask |= SPECIAL_INTERACTIVE_SIGS;
8289 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8290 mask |= SPECIAL_JOBSTOP_SIGS;
8292 /* Careful, do not re-install handlers we already installed */
8293 if (G.special_sig_mask != mask) {
8294 unsigned diff = mask & ~G.special_sig_mask;
8295 G.special_sig_mask = mask;
8296 install_sighandlers(diff);
8302 /* Set handlers to restore tty pgrp and exit */
8303 static void install_fatal_sighandlers(void)
8307 /* We will restore tty pgrp on these signals */
8309 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8310 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8311 + (1 << SIGBUS ) * HUSH_DEBUG
8312 + (1 << SIGSEGV) * HUSH_DEBUG
8313 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8315 /* bash 3.2 seems to handle these just like 'fatal' ones */
8318 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8319 * if we aren't interactive... but in this case
8320 * we never want to restore pgrp on exit, and this fn is not called
8322 /*+ (1 << SIGHUP )*/
8323 /*+ (1 << SIGTERM)*/
8324 /*+ (1 << SIGINT )*/
8326 G_fatal_sig_mask = mask;
8328 install_sighandlers(mask);
8332 static int set_mode(int state, char mode, const char *o_opt)
8337 G.o_opt[OPT_O_NOEXEC] = state;
8340 IF_HUSH_MODE_X(G_x_mode = state;)
8344 /* "set -+o" without parameter.
8345 * in bash, set -o produces this output:
8349 * We always use the second form.
8351 const char *p = o_opt_strings;
8354 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8360 idx = index_in_strings(o_opt_strings, o_opt);
8362 G.o_opt[idx] = state;
8366 return EXIT_FAILURE;
8368 return EXIT_SUCCESS;
8371 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8372 int hush_main(int argc, char **argv)
8375 OPT_login = (1 << 0),
8379 unsigned builtin_argc;
8381 struct variable *cur_var;
8382 struct variable *shell_ver;
8385 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8386 G.last_exitcode = EXIT_SUCCESS;
8388 #if ENABLE_HUSH_FAST
8389 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8392 G.argv0_for_re_execing = argv[0];
8394 /* Deal with HUSH_VERSION */
8395 shell_ver = xzalloc(sizeof(*shell_ver));
8396 shell_ver->flg_export = 1;
8397 shell_ver->flg_read_only = 1;
8398 /* Code which handles ${var<op>...} needs writable values for all variables,
8399 * therefore we xstrdup: */
8400 shell_ver->varstr = xstrdup(hush_version_str);
8401 /* Create shell local variables from the values
8402 * currently living in the environment */
8403 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8404 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8405 G.top_var = shell_ver;
8406 cur_var = G.top_var;
8409 char *value = strchr(*e, '=');
8410 if (value) { /* paranoia */
8411 cur_var->next = xzalloc(sizeof(*cur_var));
8412 cur_var = cur_var->next;
8413 cur_var->varstr = *e;
8414 cur_var->max_len = strlen(*e);
8415 cur_var->flg_export = 1;
8419 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8420 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8421 putenv(shell_ver->varstr);
8424 set_pwd_var(/*exp:*/ 1);
8426 #if BASH_HOSTNAME_VAR
8427 /* Set (but not export) HOSTNAME unless already set */
8428 if (!get_local_var_value("HOSTNAME")) {
8431 set_local_var_from_halves("HOSTNAME", uts.nodename);
8433 /* bash also exports SHLVL and _,
8434 * and sets (but doesn't export) the following variables:
8436 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8437 * BASH_VERSION='3.2.0(1)-release'
8439 * MACHTYPE=i386-pc-linux-gnu
8441 * PPID=<NNNNN> - we also do it elsewhere
8452 * PIPESTATUS=([0]="0")
8453 * HISTFILE=/<xxx>/.bash_history
8457 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8459 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8470 #if ENABLE_FEATURE_EDITING
8471 G.line_input_state = new_line_input_t(FOR_SHELL);
8474 /* Initialize some more globals to non-zero values */
8475 cmdedit_update_prompt();
8477 die_func = restore_ttypgrp_and__exit;
8479 /* Shell is non-interactive at first. We need to call
8480 * install_special_sighandlers() if we are going to execute "sh <script>",
8481 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8482 * If we later decide that we are interactive, we run install_special_sighandlers()
8483 * in order to intercept (more) signals.
8487 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8488 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8491 opt = getopt(argc, argv, "+c:xinsl"
8494 # if ENABLE_HUSH_FUNCTIONS
8504 * sh ... -c 'script'
8505 * sh ... -c 'script' ARG0 [ARG1...]
8506 * On NOMMU, if builtin_argc != 0,
8507 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8508 * "" needs to be replaced with NULL
8509 * and BARGV vector fed to builtin function.
8510 * Note: the form without ARG0 never happens:
8511 * sh ... -c 'builtin' BARGV... ""
8514 G.root_pid = getpid();
8515 G.root_ppid = getppid();
8517 G.global_argv = argv + optind;
8518 G.global_argc = argc - optind;
8520 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8521 const struct built_in_command *x;
8523 install_special_sighandlers();
8524 x = find_builtin(optarg);
8525 if (x) { /* paranoia */
8526 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8527 G.global_argv += builtin_argc;
8528 G.global_argv[-1] = NULL; /* replace "" */
8530 G.last_exitcode = x->b_function(argv + optind - 1);
8534 if (!G.global_argv[0]) {
8535 /* -c 'script' (no params): prevent empty $0 */
8536 G.global_argv--; /* points to argv[i] of 'script' */
8537 G.global_argv[0] = argv[0];
8539 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8540 install_special_sighandlers();
8541 parse_and_run_string(optarg);
8544 /* Well, we cannot just declare interactiveness,
8545 * we have to have some stuff (ctty, etc) */
8546 /* G_interactive_fd++; */
8549 /* "-s" means "read from stdin", but this is how we always
8550 * operate, so simply do nothing here. */
8556 case '<': /* "big heredoc" support */
8557 full_write1_str(optarg);
8560 unsigned long long empty_trap_mask;
8562 G.root_pid = bb_strtou(optarg, &optarg, 16);
8564 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8566 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8568 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8570 builtin_argc = bb_strtou(optarg, &optarg, 16);
8572 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8573 if (empty_trap_mask != 0) {
8575 install_special_sighandlers();
8576 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8577 for (sig = 1; sig < NSIG; sig++) {
8578 if (empty_trap_mask & (1LL << sig)) {
8579 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8580 install_sighandler(sig, SIG_IGN);
8584 # if ENABLE_HUSH_LOOPS
8586 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8592 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8594 # if ENABLE_HUSH_FUNCTIONS
8596 struct function *funcp = new_function(optarg);
8597 /* funcp->name is already set to optarg */
8598 /* funcp->body is set to NULL. It's a special case. */
8599 funcp->body_as_string = argv[optind];
8607 if (set_mode(1, opt, NULL) == 0) /* no error */
8611 fprintf(stderr, "Usage: sh [FILE]...\n"
8612 " or: sh -c command [args]...\n\n");
8618 } /* option parsing loop */
8620 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8621 G.global_argc = argc - (optind - 1);
8622 G.global_argv = argv + (optind - 1);
8623 G.global_argv[0] = argv[0];
8626 G.root_pid = getpid();
8627 G.root_ppid = getppid();
8630 /* If we are login shell... */
8631 if (flags & OPT_login) {
8633 debug_printf("sourcing /etc/profile\n");
8634 input = fopen_for_read("/etc/profile");
8635 if (input != NULL) {
8636 remember_FILE(input);
8637 install_special_sighandlers();
8638 parse_and_run_file(input);
8639 fclose_and_forget(input);
8641 /* bash: after sourcing /etc/profile,
8642 * tries to source (in the given order):
8643 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8644 * stopping on first found. --noprofile turns this off.
8645 * bash also sources ~/.bash_logout on exit.
8646 * If called as sh, skips .bash_XXX files.
8650 if (G.global_argv[1]) {
8653 * "bash <script>" (which is never interactive (unless -i?))
8654 * sources $BASH_ENV here (without scanning $PATH).
8655 * If called as sh, does the same but with $ENV.
8656 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8660 debug_printf("running script '%s'\n", G.global_argv[0]);
8661 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8662 input = xfopen_for_read(G.global_argv[0]);
8663 xfunc_error_retval = 1;
8664 remember_FILE(input);
8665 install_special_sighandlers();
8666 parse_and_run_file(input);
8667 #if ENABLE_FEATURE_CLEAN_UP
8668 fclose_and_forget(input);
8673 /* Up to here, shell was non-interactive. Now it may become one.
8674 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8677 /* A shell is interactive if the '-i' flag was given,
8678 * or if all of the following conditions are met:
8680 * no arguments remaining or the -s flag given
8681 * standard input is a terminal
8682 * standard output is a terminal
8683 * Refer to Posix.2, the description of the 'sh' utility.
8686 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8687 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8688 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8689 if (G_saved_tty_pgrp < 0)
8690 G_saved_tty_pgrp = 0;
8692 /* try to dup stdin to high fd#, >= 255 */
8693 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8694 if (G_interactive_fd < 0) {
8695 /* try to dup to any fd */
8696 G_interactive_fd = dup(STDIN_FILENO);
8697 if (G_interactive_fd < 0) {
8699 G_interactive_fd = 0;
8700 G_saved_tty_pgrp = 0;
8703 // TODO: track & disallow any attempts of user
8704 // to (inadvertently) close/redirect G_interactive_fd
8706 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8707 if (G_interactive_fd) {
8708 close_on_exec_on(G_interactive_fd);
8710 if (G_saved_tty_pgrp) {
8711 /* If we were run as 'hush &', sleep until we are
8712 * in the foreground (tty pgrp == our pgrp).
8713 * If we get started under a job aware app (like bash),
8714 * make sure we are now in charge so we don't fight over
8715 * who gets the foreground */
8717 pid_t shell_pgrp = getpgrp();
8718 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8719 if (G_saved_tty_pgrp == shell_pgrp)
8721 /* send TTIN to ourself (should stop us) */
8722 kill(- shell_pgrp, SIGTTIN);
8726 /* Install more signal handlers */
8727 install_special_sighandlers();
8729 if (G_saved_tty_pgrp) {
8730 /* Set other signals to restore saved_tty_pgrp */
8731 install_fatal_sighandlers();
8732 /* Put ourselves in our own process group
8733 * (bash, too, does this only if ctty is available) */
8734 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8735 /* Grab control of the terminal */
8736 tcsetpgrp(G_interactive_fd, getpid());
8738 enable_restore_tty_pgrp_on_exit();
8740 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8742 const char *hp = get_local_var_value("HISTFILE");
8744 hp = get_local_var_value("HOME");
8746 hp = concat_path_file(hp, ".hush_history");
8751 G.line_input_state->hist_file = hp;
8752 //set_local_var(xasprintf("HISTFILE=%s", ...));
8754 # if ENABLE_FEATURE_SH_HISTFILESIZE
8755 hp = get_local_var_value("HISTFILESIZE");
8756 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8761 install_special_sighandlers();
8763 #elif ENABLE_HUSH_INTERACTIVE
8764 /* No job control compiled in, only prompt/line editing */
8765 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8766 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8767 if (G_interactive_fd < 0) {
8768 /* try to dup to any fd */
8769 G_interactive_fd = dup(STDIN_FILENO);
8770 if (G_interactive_fd < 0)
8772 G_interactive_fd = 0;
8775 if (G_interactive_fd) {
8776 close_on_exec_on(G_interactive_fd);
8778 install_special_sighandlers();
8780 /* We have interactiveness code disabled */
8781 install_special_sighandlers();
8784 * if interactive but not a login shell, sources ~/.bashrc
8785 * (--norc turns this off, --rcfile <file> overrides)
8788 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8789 /* note: ash and hush share this string */
8790 printf("\n\n%s %s\n"
8791 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8794 "hush - the humble shell"
8798 parse_and_run_file(stdin);
8801 hush_exit(G.last_exitcode);
8806 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8807 int msh_main(int argc, char **argv)
8809 bb_error_msg("msh is deprecated, please use hush instead");
8810 return hush_main(argc, argv);
8818 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8823 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
8824 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8831 return applet_main_func(argc, argv - argc);
8834 #if ENABLE_HUSH_TEST || BASH_TEST2
8835 static int FAST_FUNC builtin_test(char **argv)
8837 return run_applet_main(argv, test_main);
8840 #if ENABLE_HUSH_ECHO
8841 static int FAST_FUNC builtin_echo(char **argv)
8843 return run_applet_main(argv, echo_main);
8846 #if ENABLE_HUSH_PRINTF
8847 static int FAST_FUNC builtin_printf(char **argv)
8849 return run_applet_main(argv, printf_main);
8853 #if ENABLE_HUSH_HELP
8854 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8856 const struct built_in_command *x;
8859 "Built-in commands:\n"
8860 "------------------\n");
8861 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8863 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8865 return EXIT_SUCCESS;
8869 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8870 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8872 show_history(G.line_input_state);
8873 return EXIT_SUCCESS;
8877 static char **skip_dash_dash(char **argv)
8880 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8885 static int FAST_FUNC builtin_cd(char **argv)
8889 argv = skip_dash_dash(argv);
8891 if (newdir == NULL) {
8892 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8893 * bash says "bash: cd: HOME not set" and does nothing
8896 const char *home = get_local_var_value("HOME");
8897 newdir = home ? home : "/";
8899 if (chdir(newdir)) {
8900 /* Mimic bash message exactly */
8901 bb_perror_msg("cd: %s", newdir);
8902 return EXIT_FAILURE;
8904 /* Read current dir (get_cwd(1) is inside) and set PWD.
8905 * Note: do not enforce exporting. If PWD was unset or unexported,
8906 * set it again, but do not export. bash does the same.
8908 set_pwd_var(/*exp:*/ 0);
8909 return EXIT_SUCCESS;
8912 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8915 return EXIT_SUCCESS;
8918 static int FAST_FUNC builtin_eval(char **argv)
8920 int rcode = EXIT_SUCCESS;
8922 argv = skip_dash_dash(argv);
8924 char *str = expand_strvec_to_string(argv);
8926 * eval "echo Hi; done" ("done" is syntax error):
8927 * "echo Hi" will not execute too.
8929 parse_and_run_string(str);
8931 rcode = G.last_exitcode;
8936 static int FAST_FUNC builtin_exec(char **argv)
8938 argv = skip_dash_dash(argv);
8939 if (argv[0] == NULL)
8940 return EXIT_SUCCESS; /* bash does this */
8942 /* Careful: we can end up here after [v]fork. Do not restore
8943 * tty pgrp then, only top-level shell process does that */
8944 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8945 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8947 /* TODO: if exec fails, bash does NOT exit! We do.
8948 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8949 * and tcsetpgrp, and this is inherently racy.
8951 execvp_or_die(argv);
8954 static int FAST_FUNC builtin_exit(char **argv)
8956 debug_printf_exec("%s()\n", __func__);
8958 /* interactive bash:
8959 * # trap "echo EEE" EXIT
8962 * There are stopped jobs.
8963 * (if there are _stopped_ jobs, running ones don't count)
8966 * EEE (then bash exits)
8968 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8971 /* note: EXIT trap is run by hush_exit */
8972 argv = skip_dash_dash(argv);
8973 if (argv[0] == NULL)
8974 hush_exit(G.last_exitcode);
8975 /* mimic bash: exit 123abc == exit 255 + error msg */
8976 xfunc_error_retval = 255;
8977 /* bash: exit -2 == exit 254, no error msg */
8978 hush_exit(xatoi(argv[0]) & 0xff);
8981 #if ENABLE_HUSH_TYPE
8982 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8983 static int FAST_FUNC builtin_type(char **argv)
8985 int ret = EXIT_SUCCESS;
8991 if (0) {} /* make conditional compile easier below */
8992 /*else if (find_alias(*argv))
8993 type = "an alias";*/
8994 #if ENABLE_HUSH_FUNCTIONS
8995 else if (find_function(*argv))
8996 type = "a function";
8998 else if (find_builtin(*argv))
8999 type = "a shell builtin";
9000 else if ((path = find_in_path(*argv)) != NULL)
9003 bb_error_msg("type: %s: not found", *argv);
9008 printf("%s is %s\n", *argv, type);
9016 #if ENABLE_HUSH_READ
9017 /* Interruptibility of read builtin in bash
9018 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9020 * Empty trap makes read ignore corresponding signal, for any signal.
9023 * - terminates non-interactive shell;
9024 * - interrupts read in interactive shell;
9025 * if it has non-empty trap:
9026 * - executes trap and returns to command prompt in interactive shell;
9027 * - executes trap and returns to read in non-interactive shell;
9029 * - is ignored (does not interrupt) read in interactive shell;
9030 * - terminates non-interactive shell;
9031 * if it has non-empty trap:
9032 * - executes trap and returns to read;
9034 * - terminates shell (regardless of interactivity);
9035 * if it has non-empty trap:
9036 * - executes trap and returns to read;
9038 static int FAST_FUNC builtin_read(char **argv)
9048 /* "!": do not abort on errors.
9049 * Option string must start with "sr" to match BUILTIN_READ_xxx
9051 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9052 if (read_flags == (uint32_t)-1)
9053 return EXIT_FAILURE;
9055 ifs = get_local_var_value("IFS"); /* can be NULL */
9058 r = shell_builtin_read(set_local_var_from_halves,
9068 if ((uintptr_t)r == 1 && errno == EINTR) {
9069 unsigned sig = check_and_run_traps();
9070 if (sig && sig != SIGINT)
9074 if ((uintptr_t)r > 1) {
9075 bb_error_msg("%s", r);
9076 r = (char*)(uintptr_t)1;
9079 return (uintptr_t)r;
9083 #if ENABLE_HUSH_UMASK
9084 static int FAST_FUNC builtin_umask(char **argv)
9091 argv = skip_dash_dash(argv);
9093 mode_t old_mask = mask;
9095 /* numeric umasks are taken as-is */
9096 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9097 if (!isdigit(argv[0][0]))
9099 mask = bb_parse_mode(argv[0], mask);
9100 if (!isdigit(argv[0][0]))
9102 if ((unsigned)mask > 0777) {
9105 * bash: umask: 'q': invalid symbolic mode operator
9106 * bash: umask: 999: octal number out of range
9108 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9113 printf("%04o\n", (unsigned) mask);
9114 /* fall through and restore mask which we set to 0 */
9118 return !rc; /* rc != 0 - success */
9122 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9123 static void print_escaped(const char *s)
9128 const char *p = strchrnul(s, '\'');
9129 /* print 'xxxx', possibly just '' */
9130 printf("'%.*s'", (int)(p - s), s);
9135 /* s points to '; print "'''...'''" */
9137 do putchar('\''); while (*++s == '\'');
9143 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL
9144 # if !ENABLE_HUSH_LOCAL
9145 #define helper_export_local(argv, exp, lvl) \
9146 helper_export_local(argv, exp)
9148 static void helper_export_local(char **argv, int exp, int lvl)
9152 char *name_end = strchrnul(name, '=');
9154 /* So far we do not check that name is valid (TODO?) */
9156 if (*name_end == '\0') {
9157 struct variable *var, **vpp;
9159 vpp = get_ptr_to_local_var(name, name_end - name);
9160 var = vpp ? *vpp : NULL;
9162 if (exp == -1) { /* unexporting? */
9163 /* export -n NAME (without =VALUE) */
9165 var->flg_export = 0;
9166 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9168 } /* else: export -n NOT_EXISTING_VAR: no-op */
9171 if (exp == 1) { /* exporting? */
9172 /* export NAME (without =VALUE) */
9174 var->flg_export = 1;
9175 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9176 putenv(var->varstr);
9180 # if ENABLE_HUSH_LOCAL
9181 if (exp == 0 /* local? */
9182 && var && var->func_nest_level == lvl
9184 /* "local x=abc; ...; local x" - ignore second local decl */
9188 /* Exporting non-existing variable.
9189 * bash does not put it in environment,
9190 * but remembers that it is exported,
9191 * and does put it in env when it is set later.
9192 * We just set it to "" and export. */
9193 /* Or, it's "local NAME" (without =VALUE).
9194 * bash sets the value to "". */
9195 name = xasprintf("%s=", name);
9197 /* (Un)exporting/making local NAME=VALUE */
9198 name = xstrdup(name);
9200 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
9205 #if ENABLE_HUSH_EXPORT
9206 static int FAST_FUNC builtin_export(char **argv)
9208 unsigned opt_unexport;
9210 #if ENABLE_HUSH_EXPORT_N
9211 /* "!": do not abort on errors */
9212 opt_unexport = getopt32(argv, "!n");
9213 if (opt_unexport == (uint32_t)-1)
9214 return EXIT_FAILURE;
9221 if (argv[0] == NULL) {
9228 /* ash emits: export VAR='VAL'
9229 * bash: declare -x VAR="VAL"
9230 * we follow ash example */
9231 const char *s = *e++;
9232 const char *p = strchr(s, '=');
9234 if (!p) /* wtf? take next variable */
9237 printf("export %.*s", (int)(p - s) + 1, s);
9238 print_escaped(p + 1);
9242 /*fflush_all(); - done after each builtin anyway */
9244 return EXIT_SUCCESS;
9247 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
9249 return EXIT_SUCCESS;
9253 #if ENABLE_HUSH_LOCAL
9254 static int FAST_FUNC builtin_local(char **argv)
9256 if (G.func_nest_level == 0) {
9257 bb_error_msg("%s: not in a function", argv[0]);
9258 return EXIT_FAILURE; /* bash compat */
9260 helper_export_local(argv, 0, G.func_nest_level);
9261 return EXIT_SUCCESS;
9265 #if ENABLE_HUSH_UNSET
9266 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9267 static int FAST_FUNC builtin_unset(char **argv)
9272 /* "!": do not abort on errors */
9273 /* "+": stop at 1st non-option */
9274 opts = getopt32(argv, "!+vf");
9275 if (opts == (unsigned)-1)
9276 return EXIT_FAILURE;
9278 bb_error_msg("unset: -v and -f are exclusive");
9279 return EXIT_FAILURE;
9285 if (!(opts & 2)) { /* not -f */
9286 if (unset_local_var(*argv)) {
9287 /* unset <nonexistent_var> doesn't fail.
9288 * Error is when one tries to unset RO var.
9289 * Message was printed by unset_local_var. */
9293 # if ENABLE_HUSH_FUNCTIONS
9305 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9306 * built-in 'set' handler
9308 * set [-abCefhmnuvx] [-o option] [argument...]
9309 * set [+abCefhmnuvx] [+o option] [argument...]
9310 * set -- [argument...]
9313 * Implementations shall support the options in both their hyphen and
9314 * plus-sign forms. These options can also be specified as options to sh.
9316 * Write out all variables and their values: set
9317 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9318 * Turn on the -x and -v options: set -xv
9319 * Unset all positional parameters: set --
9320 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9321 * Set the positional parameters to the expansion of x, even if x expands
9322 * with a leading '-' or '+': set -- $x
9324 * So far, we only support "set -- [argument...]" and some of the short names.
9326 static int FAST_FUNC builtin_set(char **argv)
9329 char **pp, **g_argv;
9330 char *arg = *++argv;
9334 for (e = G.top_var; e; e = e->next)
9336 return EXIT_SUCCESS;
9340 if (strcmp(arg, "--") == 0) {
9344 if (arg[0] != '+' && arg[0] != '-')
9346 for (n = 1; arg[n]; ++n) {
9347 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9349 if (arg[n] == 'o' && argv[1])
9352 } while ((arg = *++argv) != NULL);
9353 /* Now argv[0] is 1st argument */
9356 return EXIT_SUCCESS;
9359 /* NB: G.global_argv[0] ($0) is never freed/changed */
9360 g_argv = G.global_argv;
9361 if (G.global_args_malloced) {
9367 G.global_args_malloced = 1;
9368 pp = xzalloc(sizeof(pp[0]) * 2);
9369 pp[0] = g_argv[0]; /* retain $0 */
9372 /* This realloc's G.global_argv */
9373 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9380 return EXIT_SUCCESS;
9382 /* Nothing known, so abort */
9384 bb_error_msg("set: %s: invalid option", arg);
9385 return EXIT_FAILURE;
9389 static int FAST_FUNC builtin_shift(char **argv)
9392 argv = skip_dash_dash(argv);
9396 if (n >= 0 && n < G.global_argc) {
9397 if (G_global_args_malloced) {
9400 free(G.global_argv[m++]);
9403 memmove(&G.global_argv[1], &G.global_argv[n+1],
9404 G.global_argc * sizeof(G.global_argv[0]));
9405 return EXIT_SUCCESS;
9407 return EXIT_FAILURE;
9410 static int FAST_FUNC builtin_source(char **argv)
9412 char *arg_path, *filename;
9415 char *args_need_save;
9416 #if ENABLE_HUSH_FUNCTIONS
9420 argv = skip_dash_dash(argv);
9423 /* bash says: "bash: .: filename argument required" */
9424 return 2; /* bash compat */
9427 if (!strchr(filename, '/')) {
9428 arg_path = find_in_path(filename);
9430 filename = arg_path;
9432 input = remember_FILE(fopen_or_warn(filename, "r"));
9435 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9436 /* POSIX: non-interactive shell should abort here,
9437 * not merely fail. So far no one complained :)
9439 return EXIT_FAILURE;
9442 #if ENABLE_HUSH_FUNCTIONS
9443 sv_flg = G_flag_return_in_progress;
9444 /* "we are inside sourced file, ok to use return" */
9445 G_flag_return_in_progress = -1;
9447 args_need_save = argv[1]; /* used as a boolean variable */
9449 save_and_replace_G_args(&sv, argv);
9451 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9452 G.last_exitcode = 0;
9453 parse_and_run_file(input);
9454 fclose_and_forget(input);
9456 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9457 restore_G_args(&sv, argv);
9458 #if ENABLE_HUSH_FUNCTIONS
9459 G_flag_return_in_progress = sv_flg;
9462 return G.last_exitcode;
9465 #if ENABLE_HUSH_TRAP
9466 static int FAST_FUNC builtin_trap(char **argv)
9472 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9477 /* No args: print all trapped */
9478 for (i = 0; i < NSIG; ++i) {
9481 print_escaped(G_traps[i]);
9482 /* note: bash adds "SIG", but only if invoked
9483 * as "bash". If called as "sh", or if set -o posix,
9484 * then it prints short signal names.
9485 * We are printing short names: */
9486 printf(" %s\n", get_signame(i));
9489 /*fflush_all(); - done after each builtin anyway */
9490 return EXIT_SUCCESS;
9494 /* If first arg is a number: reset all specified signals */
9495 sig = bb_strtou(*argv, NULL, 10);
9501 sighandler_t handler;
9503 sig = get_signum(*argv++);
9504 if (sig < 0 || sig >= NSIG) {
9506 /* Mimic bash message exactly */
9507 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9512 G_traps[sig] = xstrdup(new_cmd);
9514 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9515 get_signame(sig), sig, G_traps[sig]);
9517 /* There is no signal for 0 (EXIT) */
9522 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9524 /* We are removing trap handler */
9525 handler = pick_sighandler(sig);
9526 install_sighandler(sig, handler);
9531 if (!argv[1]) { /* no second arg */
9532 bb_error_msg("trap: invalid arguments");
9533 return EXIT_FAILURE;
9536 /* First arg is "-": reset all specified to default */
9537 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9538 /* Everything else: set arg as signal handler
9539 * (includes "" case, which ignores signal) */
9540 if (argv[0][0] == '-') {
9541 if (argv[0][1] == '\0') { /* "-" */
9542 /* new_cmd remains NULL: "reset these sigs" */
9545 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9548 /* else: "-something", no special meaning */
9553 goto process_sig_list;
9558 static struct pipe *parse_jobspec(const char *str)
9563 if (sscanf(str, "%%%u", &jobnum) != 1) {
9565 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9567 bb_error_msg("bad argument '%s'", str);
9570 /* It is "%%", "%+" or "%" - current job */
9571 jobnum = G.last_jobid;
9573 bb_error_msg("no current job");
9577 for (pi = G.job_list; pi; pi = pi->next) {
9578 if (pi->jobid == jobnum) {
9582 bb_error_msg("%u: no such job", jobnum);
9586 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9589 const char *status_string;
9591 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9592 for (job = G.job_list; job; job = job->next) {
9593 if (job->alive_cmds == job->stopped_cmds)
9594 status_string = "Stopped";
9596 status_string = "Running";
9598 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9600 return EXIT_SUCCESS;
9603 /* built-in 'fg' and 'bg' handler */
9604 static int FAST_FUNC builtin_fg_bg(char **argv)
9609 if (!G_interactive_fd)
9610 return EXIT_FAILURE;
9612 /* If they gave us no args, assume they want the last backgrounded task */
9614 for (pi = G.job_list; pi; pi = pi->next) {
9615 if (pi->jobid == G.last_jobid) {
9619 bb_error_msg("%s: no current job", argv[0]);
9620 return EXIT_FAILURE;
9623 pi = parse_jobspec(argv[1]);
9625 return EXIT_FAILURE;
9627 /* TODO: bash prints a string representation
9628 * of job being foregrounded (like "sleep 1 | cat") */
9629 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9630 /* Put the job into the foreground. */
9631 tcsetpgrp(G_interactive_fd, pi->pgrp);
9634 /* Restart the processes in the job */
9635 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9636 for (i = 0; i < pi->num_cmds; i++) {
9637 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9639 pi->stopped_cmds = 0;
9641 i = kill(- pi->pgrp, SIGCONT);
9643 if (errno == ESRCH) {
9644 delete_finished_bg_job(pi);
9645 return EXIT_SUCCESS;
9647 bb_perror_msg("kill (SIGCONT)");
9650 if (argv[0][0] == 'f') {
9652 return checkjobs_and_fg_shell(pi);
9654 return EXIT_SUCCESS;
9658 #if ENABLE_HUSH_KILL
9659 static int FAST_FUNC builtin_kill(char **argv)
9663 # if ENABLE_HUSH_JOB
9664 if (argv[1] && strcmp(argv[1], "-l") != 0) {
9672 if (argv[i][0] != '%')
9675 * "kill %N" - job kill
9676 * Converting to pgrp / pid kill
9678 pi = parse_jobspec(argv[i]);
9680 /* Eat bad jobspec */
9684 argv[j - 1] = argv[j];
9691 * In jobs started under job control, we signal
9692 * entire process group by kill -PGRP_ID.
9693 * This happens, f.e., in interactive shell.
9695 * Otherwise, we signal each child via
9696 * kill PID1 PID2 PID3.
9698 * sh -c 'sleep 1|sleep 1 & kill %1'
9699 * sh -c 'true|sleep 2 & sleep 1; kill %1'
9700 * sh -c 'true|sleep 1 & sleep 2; kill %1'
9702 n = G_interactive_fd ? 1 : pi->num_cmds;
9703 dst = alloca(n * sizeof(int)*4);
9705 if (G_interactive_fd)
9706 dst += sprintf(dst, " -%u", (int)pi->pgrp);
9707 else for (j = 0; j < n; j++) {
9708 struct command *cmd = &pi->cmds[j];
9709 /* Skip exited members of the job */
9713 * kill_main has matching code to expect
9714 * leading space. Needed to not confuse
9715 * negative pids with "kill -SIGNAL_NO" syntax
9717 dst += sprintf(dst, " %u", (int)cmd->pid);
9720 } while (argv[++i]);
9724 if (argv[1] || ret == 0) {
9725 ret = run_applet_main(argv, kill_main);
9727 /* else: ret = 1, "kill %bad_jobspec" case */
9732 #if ENABLE_HUSH_WAIT
9733 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9734 #if !ENABLE_HUSH_JOB
9735 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9737 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9744 if (!sigisemptyset(&G.pending_set))
9747 /* waitpid is not interruptible by SA_RESTARTed
9748 * signals which we use. Thus, this ugly dance:
9751 /* Make sure possible SIGCHLD is stored in kernel's
9752 * pending signal mask before we call waitpid.
9753 * Or else we may race with SIGCHLD, lose it,
9754 * and get stuck in sigsuspend...
9756 sigfillset(&oldset); /* block all signals, remember old set */
9757 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9759 if (!sigisemptyset(&G.pending_set)) {
9760 /* Crap! we raced with some signal! */
9764 /*errno = 0; - checkjobs does this */
9765 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9766 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9767 debug_printf_exec("checkjobs:%d\n", ret);
9770 int rcode = job_exited_or_stopped(waitfor_pipe);
9771 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9774 sigprocmask(SIG_SETMASK, &oldset, NULL);
9779 /* if ECHILD, there are no children (ret is -1 or 0) */
9780 /* if ret == 0, no children changed state */
9781 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9782 if (errno == ECHILD || ret) {
9784 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9786 sigprocmask(SIG_SETMASK, &oldset, NULL);
9789 /* Wait for SIGCHLD or any other signal */
9790 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9791 /* Note: sigsuspend invokes signal handler */
9792 sigsuspend(&oldset);
9794 sigprocmask(SIG_SETMASK, &oldset, NULL);
9796 /* So, did we get a signal? */
9797 sig = check_and_run_traps();
9798 if (sig /*&& sig != SIGCHLD - always true */) {
9802 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9807 static int FAST_FUNC builtin_wait(char **argv)
9812 argv = skip_dash_dash(argv);
9813 if (argv[0] == NULL) {
9814 /* Don't care about wait results */
9815 /* Note 1: must wait until there are no more children */
9816 /* Note 2: must be interruptible */
9818 * $ sleep 3 & sleep 6 & wait
9823 * $ sleep 3 & sleep 6 & wait
9827 * ^C <-- after ~4 sec from keyboard
9830 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9834 pid_t pid = bb_strtou(*argv, NULL, 10);
9835 if (errno || pid <= 0) {
9837 if (argv[0][0] == '%') {
9838 struct pipe *wait_pipe;
9839 ret = 127; /* bash compat for bad jobspecs */
9840 wait_pipe = parse_jobspec(*argv);
9842 ret = job_exited_or_stopped(wait_pipe);
9844 ret = wait_for_child_or_signal(wait_pipe, 0);
9846 /* else: parse_jobspec() already emitted error msg */
9850 /* mimic bash message */
9851 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9853 continue; /* bash checks all argv[] */
9856 /* Do we have such child? */
9857 ret = waitpid(pid, &status, WNOHANG);
9860 if (errno == ECHILD) {
9861 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9862 /* "wait $!" but last bg task has already exited. Try:
9863 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9864 * In bash it prints exitcode 0, then 3.
9865 * In dash, it is 127.
9867 /* ret = G.last_bg_pid_exitstatus - FIXME */
9869 /* Example: "wait 1". mimic bash message */
9870 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9874 bb_perror_msg("wait %s", *argv);
9877 continue; /* bash checks all argv[] */
9880 /* Yes, and it still runs */
9881 ret = wait_for_child_or_signal(NULL, pid);
9883 /* Yes, and it just exited */
9884 process_wait_result(NULL, pid, status);
9885 ret = WEXITSTATUS(status);
9886 if (WIFSIGNALED(status))
9887 ret = 128 + WTERMSIG(status);
9895 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9896 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9899 def = bb_strtou(argv[1], NULL, 10);
9900 if (errno || def < def_min || argv[2]) {
9901 bb_error_msg("%s: bad arguments", argv[0]);
9909 #if ENABLE_HUSH_LOOPS
9910 static int FAST_FUNC builtin_break(char **argv)
9913 if (G.depth_of_loop == 0) {
9914 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9915 /* if we came from builtin_continue(), need to undo "= 1" */
9916 G.flag_break_continue = 0;
9917 return EXIT_SUCCESS; /* bash compat */
9919 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9921 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9922 if (depth == UINT_MAX)
9923 G.flag_break_continue = BC_BREAK;
9924 if (G.depth_of_loop < depth)
9925 G.depth_break_continue = G.depth_of_loop;
9927 return EXIT_SUCCESS;
9930 static int FAST_FUNC builtin_continue(char **argv)
9932 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9933 return builtin_break(argv);
9937 #if ENABLE_HUSH_FUNCTIONS
9938 static int FAST_FUNC builtin_return(char **argv)
9942 if (G_flag_return_in_progress != -1) {
9943 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9944 return EXIT_FAILURE; /* bash compat */
9947 G_flag_return_in_progress = 1;
9950 * out of range: wraps around at 256, does not error out
9951 * non-numeric param:
9952 * f() { false; return qwe; }; f; echo $?
9953 * bash: return: qwe: numeric argument required <== we do this
9954 * 255 <== we also do this
9956 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
9961 #if ENABLE_HUSH_MEMLEAK
9962 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9967 # ifdef M_TRIM_THRESHOLD
9968 /* Optional. Reduces probability of false positives */
9971 /* Crude attempt to find where "free memory" starts,
9972 * sans fragmentation. */
9974 l = (unsigned long)p;
9977 if (l < (unsigned long)p) l = (unsigned long)p;
9983 struct mallinfo mi = mallinfo();
9984 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9985 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9989 if (!G.memleak_value)
9990 G.memleak_value = l;
9992 l -= G.memleak_value;
9999 /* Exitcode is "how many kilobytes we leaked since 1st call" */