1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * make complex ${var%...} constructs support optional
45 * make here documents optional
46 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
50 * builtins mandated by standards we don't support:
51 * [un]alias, command, fc, getopts, times:
52 * command -v CMD: print "/path/to/CMD"
53 * prints "CMD" for builtins
54 * prints "alias ALIAS='EXPANSION'" for aliases
55 * prints nothing and sets $? to 1 if not found
56 * command -V CMD: print "CMD is /path/CMD|a shell builtin|etc"
57 * command [-p] CMD: run CMD, even if a function CMD also exists
58 * (can use this to override standalone shell as well)
59 * -p: use default $PATH
60 * command BLTIN: disables special-ness (e.g. errors do not abort)
61 * getopts: getopt() for shells
62 * times: print getrusage(SELF/CHILDREN).ru_utime/ru_stime
63 * fc -l[nr] [BEG] [END]: list range of commands in history
64 * fc [-e EDITOR] [BEG] [END]: edit/rerun range of commands
65 * fc -s [PAT=REP] [CMD]: rerun CMD, replacing PAT with REP
68 * redirection of stdout+stderr: &> and >&
69 * reserved words: function select
70 * advanced test: [[ ]]
71 * process substitution: <(list) and >(list)
74 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
75 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
76 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
78 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
79 * This is exactly equivalent to let "EXPR".
80 * $[EXPR]: synonym for $((EXPR))
81 * indirect expansion: ${!VAR}
82 * substring op on @: ${@:n:m}
85 * Some builtins mandated by standards:
86 * newgrp [GRP]: not a builtin in bash but a suid binary
87 * which spawns a new shell with new group ID
88 * In bash, export builtin is special, its arguments are assignments
89 * and therefore expansion of them should be "one-word" expansion:
90 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
92 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
93 * ls: cannot access i=a: No such file or directory
94 * ls: cannot access b: No such file or directory
95 * Note1: same applies to local builtin.
96 * Note2: bash 3.2.33(1) does this only if export word itself
98 * $ export i=`echo 'aaa bbb'`; echo "$i"
100 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
104 //config: bool "hush (64 kb)"
107 //config: hush is a small shell. It handles the normal flow control
108 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
109 //config: case/esac. Redirections, here documents, $((arithmetic))
110 //config: and functions are supported.
112 //config: It will compile and work on no-mmu systems.
114 //config: It does not handle select, aliases, tilde expansion,
115 //config: &>file and >&file redirection of stdout+stderr.
117 //config:config HUSH_BASH_COMPAT
118 //config: bool "bash-compatible extensions"
120 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
122 //config:config HUSH_BRACE_EXPANSION
123 //config: bool "Brace expansion"
125 //config: depends on HUSH_BASH_COMPAT
127 //config: Enable {abc,def} extension.
129 //config:config HUSH_INTERACTIVE
130 //config: bool "Interactive mode"
132 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
134 //config: Enable interactive mode (prompt and command editing).
135 //config: Without this, hush simply reads and executes commands
136 //config: from stdin just like a shell script from a file.
137 //config: No prompt, no PS1/PS2 magic shell variables.
139 //config:config HUSH_SAVEHISTORY
140 //config: bool "Save command history to .hush_history"
142 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
144 //config:config HUSH_JOB
145 //config: bool "Job control"
147 //config: depends on HUSH_INTERACTIVE
149 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
150 //config: command (not entire shell), fg/bg builtins work. Without this option,
151 //config: "cmd &" still works by simply spawning a process and immediately
152 //config: prompting for next command (or executing next command in a script),
153 //config: but no separate process group is formed.
155 //config:config HUSH_TICK
156 //config: bool "Support process substitution"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable `command` and $(command).
162 //config:config HUSH_IF
163 //config: bool "Support if/then/elif/else/fi"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config:config HUSH_LOOPS
168 //config: bool "Support for, while and until loops"
170 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
172 //config:config HUSH_CASE
173 //config: bool "Support case ... esac statement"
175 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
177 //config: Enable case ... esac statement. +400 bytes.
179 //config:config HUSH_FUNCTIONS
180 //config: bool "Support funcname() { commands; } syntax"
182 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
184 //config: Enable support for shell functions. +800 bytes.
186 //config:config HUSH_LOCAL
187 //config: bool "local builtin"
189 //config: depends on HUSH_FUNCTIONS
191 //config: Enable support for local variables in functions.
193 //config:config HUSH_RANDOM_SUPPORT
194 //config: bool "Pseudorandom generator and $RANDOM variable"
196 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
198 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
199 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
201 //config:config HUSH_MODE_X
202 //config: bool "Support 'hush -x' option and 'set -x' command"
204 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
206 //config: This instructs hush to print commands before execution.
207 //config: Adds ~300 bytes.
209 //config:config HUSH_ECHO
210 //config: bool "echo builtin"
212 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
214 //config:config HUSH_PRINTF
215 //config: bool "printf builtin"
217 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
219 //config:config HUSH_TEST
220 //config: bool "test builtin"
222 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
224 //config:config HUSH_HELP
225 //config: bool "help builtin"
227 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
229 //config:config HUSH_EXPORT
230 //config: bool "export builtin"
232 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
234 //config:config HUSH_EXPORT_N
235 //config: bool "Support 'export -n' option"
237 //config: depends on HUSH_EXPORT
239 //config: export -n unexports variables. It is a bash extension.
241 //config:config HUSH_READONLY
242 //config: bool "readonly builtin"
244 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
246 //config: Enable support for read-only variables.
248 //config:config HUSH_KILL
249 //config: bool "kill builtin (supports kill %jobspec)"
251 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
253 //config:config HUSH_WAIT
254 //config: bool "wait builtin"
256 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
258 //config:config HUSH_TRAP
259 //config: bool "trap builtin"
261 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
263 //config:config HUSH_TYPE
264 //config: bool "type builtin"
266 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
268 //config:config HUSH_READ
269 //config: bool "read builtin"
271 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
273 //config:config HUSH_SET
274 //config: bool "set builtin"
276 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
278 //config:config HUSH_UNSET
279 //config: bool "unset builtin"
281 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
283 //config:config HUSH_ULIMIT
284 //config: bool "ulimit builtin"
286 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
288 //config:config HUSH_UMASK
289 //config: bool "umask builtin"
291 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
293 //config:config HUSH_MEMLEAK
294 //config: bool "memleak builtin (debugging)"
296 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
298 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
299 // APPLET_ODDNAME:name main location suid_type help
300 //applet:IF_SH_IS_HUSH( APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
301 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
303 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
304 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
305 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
306 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
308 /* -i (interactive) and -s (read stdin) are also accepted,
309 * but currently do nothing, therefore aren't shown in help.
310 * NOMMU-specific options are not meant to be used by users,
311 * therefore we don't show them either.
313 //usage:#define hush_trivial_usage
314 //usage: "[-enxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
315 //usage:#define hush_full_usage "\n\n"
316 //usage: "Unix shell interpreter"
318 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
319 || defined(__APPLE__) \
321 # include <malloc.h> /* for malloc_trim */
324 /* #include <dmalloc.h> */
326 # include <fnmatch.h>
328 #include <sys/utsname.h> /* for setting $HOSTNAME */
330 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
332 #include "shell_common.h"
335 #if ENABLE_HUSH_RANDOM_SUPPORT
338 # define CLEAR_RANDOM_T(rnd) ((void)0)
340 #ifndef F_DUPFD_CLOEXEC
341 # define F_DUPFD_CLOEXEC F_DUPFD
344 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
348 /* So far, all bash compat is controlled by one config option */
349 /* Separate defines document which part of code implements what */
350 #define BASH_PATTERN_SUBST ENABLE_HUSH_BASH_COMPAT
351 #define BASH_SUBSTR ENABLE_HUSH_BASH_COMPAT
352 #define BASH_SOURCE ENABLE_HUSH_BASH_COMPAT
353 #define BASH_HOSTNAME_VAR ENABLE_HUSH_BASH_COMPAT
354 #define BASH_TEST2 (ENABLE_HUSH_BASH_COMPAT && ENABLE_HUSH_TEST)
358 #define LEAK_HUNTING 0
359 #define BUILD_AS_NOMMU 0
360 /* Enable/disable sanity checks. Ok to enable in production,
361 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
362 * Keeping 1 for now even in released versions.
365 /* Slightly bigger (+200 bytes), but faster hush.
366 * So far it only enables a trick with counting SIGCHLDs and forks,
367 * which allows us to do fewer waitpid's.
368 * (we can detect a case where neither forks were done nor SIGCHLDs happened
369 * and therefore waitpid will return the same result as last time)
371 #define ENABLE_HUSH_FAST 0
372 /* TODO: implement simplified code for users which do not need ${var%...} ops
373 * So far ${var%...} ops are always enabled:
375 #define ENABLE_HUSH_DOLLAR_OPS 1
380 # undef USE_FOR_NOMMU
383 # define USE_FOR_NOMMU(...) __VA_ARGS__
384 # define USE_FOR_MMU(...)
387 #include "NUM_APPLETS.h"
389 /* STANDALONE does not make sense, and won't compile */
390 # undef CONFIG_FEATURE_SH_STANDALONE
391 # undef ENABLE_FEATURE_SH_STANDALONE
392 # undef IF_FEATURE_SH_STANDALONE
393 # undef IF_NOT_FEATURE_SH_STANDALONE
394 # define ENABLE_FEATURE_SH_STANDALONE 0
395 # define IF_FEATURE_SH_STANDALONE(...)
396 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
399 #if !ENABLE_HUSH_INTERACTIVE
400 # undef ENABLE_FEATURE_EDITING
401 # define ENABLE_FEATURE_EDITING 0
402 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
403 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
404 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
405 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
408 /* Do we support ANY keywords? */
409 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 # define HAS_KEYWORDS 1
411 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
412 # define IF_HAS_NO_KEYWORDS(...)
414 # define HAS_KEYWORDS 0
415 # define IF_HAS_KEYWORDS(...)
416 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
419 /* If you comment out one of these below, it will be #defined later
420 * to perform debug printfs to stderr: */
421 #define debug_printf(...) do {} while (0)
422 /* Finer-grained debug switches */
423 #define debug_printf_parse(...) do {} while (0)
424 #define debug_print_tree(a, b) do {} while (0)
425 #define debug_printf_exec(...) do {} while (0)
426 #define debug_printf_env(...) do {} while (0)
427 #define debug_printf_jobs(...) do {} while (0)
428 #define debug_printf_expand(...) do {} while (0)
429 #define debug_printf_varexp(...) do {} while (0)
430 #define debug_printf_glob(...) do {} while (0)
431 #define debug_printf_redir(...) do {} while (0)
432 #define debug_printf_list(...) do {} while (0)
433 #define debug_printf_subst(...) do {} while (0)
434 #define debug_printf_clean(...) do {} while (0)
436 #define ERR_PTR ((void*)(long)1)
438 #define JOB_STATUS_FORMAT "[%u] %-22s %.40s\n"
440 #define _SPECIAL_VARS_STR "_*@$!?#"
441 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
442 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
443 #if BASH_PATTERN_SUBST
444 /* Support / and // replace ops */
445 /* Note that // is stored as \ in "encoded" string representation */
446 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
447 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
448 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
450 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
451 # define VAR_SUBST_OPS "%#:-=+?"
452 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
455 #define SPECIAL_VAR_SYMBOL 3
459 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
461 /* This supports saving pointers malloced in vfork child,
462 * to be freed in the parent.
465 typedef struct nommu_save_t {
467 struct variable *old_vars;
469 char **argv_from_re_execing;
482 #if ENABLE_HUSH_LOOPS
489 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
494 /* three pseudo-keywords support contrived "case" syntax: */
495 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
496 RES_MATCH , /* "word)" */
497 RES_CASE_BODY, /* "this command is inside CASE" */
504 typedef struct o_string {
506 int length; /* position where data is appended */
509 /* At least some part of the string was inside '' or "",
510 * possibly empty one: word"", wo''rd etc. */
511 smallint has_quoted_part;
512 smallint has_empty_slot;
513 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
516 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
518 /* Protect newly added chars against globbing
519 * by prepending \ to *, ?, [, \ */
520 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
523 MAYBE_ASSIGNMENT = 0,
524 DEFINITELY_ASSIGNMENT = 1,
526 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
529 /* Used for initialization: o_string foo = NULL_O_STRING; */
530 #define NULL_O_STRING { NULL }
532 #ifndef debug_printf_parse
533 static const char *const assignment_flag[] = {
535 "DEFINITELY_ASSIGNMENT",
541 typedef struct in_str {
543 #if ENABLE_HUSH_INTERACTIVE
544 smallint promptmode; /* 0: PS1, 1: PS2 */
551 /* The descrip member of this structure is only used to make
552 * debugging output pretty */
553 static const struct {
555 signed char default_fd;
558 { O_RDONLY, 0, "<" },
559 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
560 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
561 { O_CREAT|O_RDWR, 1, "<>" },
562 { O_RDONLY, 0, "<<" },
563 /* Should not be needed. Bogus default_fd helps in debugging */
564 /* { O_RDONLY, 77, "<<" }, */
567 struct redir_struct {
568 struct redir_struct *next;
569 char *rd_filename; /* filename */
570 int rd_fd; /* fd to redirect */
571 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
573 smallint rd_type; /* (enum redir_type) */
574 /* note: for heredocs, rd_filename contains heredoc delimiter,
575 * and subsequently heredoc itself; and rd_dup is a bitmask:
576 * bit 0: do we need to trim leading tabs?
577 * bit 1: is heredoc quoted (<<'delim' syntax) ?
580 typedef enum redir_type {
582 REDIRECT_OVERWRITE = 1,
585 REDIRECT_HEREDOC = 4,
586 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
589 REDIRFD_SYNTAX_ERR = -2,
590 REDIRFD_TO_FILE = -1,
591 /* otherwise, rd_fd is redirected to rd_dup */
593 HEREDOC_SKIPTABS = 1,
599 pid_t pid; /* 0 if exited */
600 int assignment_cnt; /* how many argv[i] are assignments? */
601 smallint cmd_type; /* CMD_xxx */
603 #define CMD_SUBSHELL 1
605 /* used for "[[ EXPR ]]" */
606 # define CMD_SINGLEWORD_NOGLOB 2
608 #if ENABLE_HUSH_FUNCTIONS
609 # define CMD_FUNCDEF 3
612 smalluint cmd_exitcode;
613 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
616 char *group_as_string;
618 #if ENABLE_HUSH_FUNCTIONS
619 struct function *child_func;
620 /* This field is used to prevent a bug here:
621 * while...do f1() {a;}; f1; f1() {b;}; f1; done
622 * When we execute "f1() {a;}" cmd, we create new function and clear
623 * cmd->group, cmd->group_as_string, cmd->argv[0].
624 * When we execute "f1() {b;}", we notice that f1 exists,
625 * and that its "parent cmd" struct is still "alive",
626 * we put those fields back into cmd->xxx
627 * (struct function has ->parent_cmd ptr to facilitate that).
628 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
629 * Without this trick, loop would execute a;b;b;b;...
630 * instead of correct sequence a;b;a;b;...
631 * When command is freed, it severs the link
632 * (sets ->child_func->parent_cmd to NULL).
635 char **argv; /* command name and arguments */
636 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
637 * and on execution these are substituted with their values.
638 * Substitution can make _several_ words out of one argv[n]!
639 * Example: argv[0]=='.^C*^C.' here: echo .$*.
640 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
642 struct redir_struct *redirects; /* I/O redirections */
644 /* Is there anything in this command at all? */
645 #define IS_NULL_CMD(cmd) \
646 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
650 int num_cmds; /* total number of commands in pipe */
651 int alive_cmds; /* number of commands running (not exited) */
652 int stopped_cmds; /* number of commands alive, but stopped */
654 unsigned jobid; /* job number */
655 pid_t pgrp; /* process group ID for the job */
656 char *cmdtext; /* name of job */
658 struct command *cmds; /* array of commands in pipe */
659 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
660 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
661 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
663 typedef enum pipe_style {
669 /* Is there anything in this pipe at all? */
670 #define IS_NULL_PIPE(pi) \
671 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
673 /* This holds pointers to the various results of parsing */
674 struct parse_context {
675 /* linked list of pipes */
676 struct pipe *list_head;
677 /* last pipe (being constructed right now) */
679 /* last command in pipe (being constructed right now) */
680 struct command *command;
681 /* last redirect in command->redirects list */
682 struct redir_struct *pending_redirect;
688 smallint ctx_inverted; /* "! cmd | cmd" */
690 smallint ctx_dsemicolon; /* ";;" seen */
692 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
694 /* group we are enclosed in:
695 * example: "if pipe1; pipe2; then pipe3; fi"
696 * when we see "if" or "then", we malloc and copy current context,
697 * and make ->stack point to it. then we parse pipeN.
698 * when closing "then" / fi" / whatever is found,
699 * we move list_head into ->stack->command->group,
700 * copy ->stack into current context, and delete ->stack.
701 * (parsing of { list } and ( list ) doesn't use this method)
703 struct parse_context *stack;
707 /* On program start, environ points to initial environment.
708 * putenv adds new pointers into it, unsetenv removes them.
709 * Neither of these (de)allocates the strings.
710 * setenv allocates new strings in malloc space and does putenv,
711 * and thus setenv is unusable (leaky) for shell's purposes */
712 #define setenv(...) setenv_is_leaky_dont_use()
714 struct variable *next;
715 char *varstr; /* points to "name=" portion */
716 #if ENABLE_HUSH_LOCAL
717 unsigned func_nest_level;
719 int max_len; /* if > 0, name is part of initial env; else name is malloced */
720 smallint flg_export; /* putenv should be done on this var */
721 smallint flg_read_only;
729 #if ENABLE_HUSH_FUNCTIONS
731 struct function *next;
733 struct command *parent_cmd;
736 char *body_as_string;
742 /* set -/+o OPT support. (TODO: make it optional)
743 * bash supports the following opts:
754 * interactive-comments on
772 static const char o_opt_strings[] ALIGN1 =
776 #if ENABLE_HUSH_MODE_X
784 #if ENABLE_HUSH_MODE_X
792 struct FILE_list *next;
798 /* "Globals" within this file */
799 /* Sorted roughly by size (smaller offsets == smaller code) */
801 /* interactive_fd != 0 means we are an interactive shell.
802 * If we are, then saved_tty_pgrp can also be != 0, meaning
803 * that controlling tty is available. With saved_tty_pgrp == 0,
804 * job control still works, but terminal signals
805 * (^C, ^Z, ^Y, ^\) won't work at all, and background
806 * process groups can only be created with "cmd &".
807 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
808 * to give tty to the foreground process group,
809 * and will take it back when the group is stopped (^Z)
812 #if ENABLE_HUSH_INTERACTIVE
813 /* 'interactive_fd' is a fd# open to ctty, if we have one
814 * _AND_ if we decided to act interactively */
818 # define G_interactive_fd (G.interactive_fd)
820 # define G_interactive_fd 0
822 #if ENABLE_FEATURE_EDITING
823 line_input_t *line_input_state;
828 #if ENABLE_HUSH_RANDOM_SUPPORT
834 pid_t saved_tty_pgrp;
835 struct pipe *job_list;
836 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
838 # define G_saved_tty_pgrp 0
840 /* How deeply are we in context where "set -e" is ignored */
842 /* "set -e" rules (do we follow them correctly?):
843 * Exit if pipe, list, or compound command exits with a non-zero status.
844 * Shell does not exit if failed command is part of condition in
845 * if/while, part of && or || list except the last command, any command
846 * in a pipe but the last, or if the command's return value is being
847 * inverted with !. If a compound command other than a subshell returns a
848 * non-zero status because a command failed while -e was being ignored, the
849 * shell does not exit. A trap on ERR, if set, is executed before the shell
850 * exits [ERR is a bashism].
852 * If a compound command or function executes in a context where -e is
853 * ignored, none of the commands executed within are affected by the -e
854 * setting. If a compound command or function sets -e while executing in a
855 * context where -e is ignored, that setting does not have any effect until
856 * the compound command or the command containing the function call completes.
859 char o_opt[NUM_OPT_O];
860 #if ENABLE_HUSH_MODE_X
861 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
865 smallint flag_SIGINT;
866 #if ENABLE_HUSH_LOOPS
867 smallint flag_break_continue;
869 #if ENABLE_HUSH_FUNCTIONS
870 /* 0: outside of a function (or sourced file)
871 * -1: inside of a function, ok to use return builtin
872 * 1: return is invoked, skip all till end of func
874 smallint flag_return_in_progress;
875 # define G_flag_return_in_progress (G.flag_return_in_progress)
877 # define G_flag_return_in_progress 0
879 smallint exiting; /* used to prevent EXIT trap recursion */
880 /* These four support $?, $#, and $1 */
881 smalluint last_exitcode;
882 smalluint last_bg_pid_exitcode;
884 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
885 smalluint global_args_malloced;
886 # define G_global_args_malloced (G.global_args_malloced)
888 # define G_global_args_malloced 0
890 /* how many non-NULL argv's we have. NB: $# + 1 */
894 char *argv0_for_re_execing;
896 #if ENABLE_HUSH_LOOPS
897 unsigned depth_break_continue;
898 unsigned depth_of_loop;
902 struct variable *top_var;
903 char **expanded_assignments;
904 #if ENABLE_HUSH_FUNCTIONS
905 struct function *top_func;
906 # if ENABLE_HUSH_LOCAL
907 struct variable **shadowed_vars_pp;
908 unsigned func_nest_level;
911 /* Signal and trap handling */
913 unsigned count_SIGCHLD;
914 unsigned handled_SIGCHLD;
915 smallint we_have_children;
917 struct FILE_list *FILE_list;
918 /* Which signals have non-DFL handler (even with no traps set)?
919 * Set at the start to:
920 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
921 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
922 * The rest is cleared right before execv syscalls.
923 * Other than these two times, never modified.
925 unsigned special_sig_mask;
927 unsigned fatal_sig_mask;
928 # define G_fatal_sig_mask (G.fatal_sig_mask)
930 # define G_fatal_sig_mask 0
933 char **traps; /* char *traps[NSIG] */
934 # define G_traps G.traps
936 # define G_traps ((char**)NULL)
938 sigset_t pending_set;
939 #if ENABLE_HUSH_MEMLEAK
940 unsigned long memleak_value;
946 #if ENABLE_FEATURE_EDITING
947 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
950 #define G (*ptr_to_globals)
951 /* Not #defining name to G.name - this quickly gets unwieldy
952 * (too many defines). Also, I actually prefer to see when a variable
953 * is global, thus "G." prefix is a useful hint */
954 #define INIT_G() do { \
955 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
956 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
957 sigfillset(&G.sa.sa_mask); \
958 G.sa.sa_flags = SA_RESTART; \
962 /* Function prototypes for builtins */
963 static int builtin_cd(char **argv) FAST_FUNC;
965 static int builtin_echo(char **argv) FAST_FUNC;
967 static int builtin_eval(char **argv) FAST_FUNC;
968 static int builtin_exec(char **argv) FAST_FUNC;
969 static int builtin_exit(char **argv) FAST_FUNC;
970 #if ENABLE_HUSH_EXPORT
971 static int builtin_export(char **argv) FAST_FUNC;
973 #if ENABLE_HUSH_READONLY
974 static int builtin_readonly(char **argv) FAST_FUNC;
977 static int builtin_fg_bg(char **argv) FAST_FUNC;
978 static int builtin_jobs(char **argv) FAST_FUNC;
981 static int builtin_help(char **argv) FAST_FUNC;
983 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
984 static int builtin_history(char **argv) FAST_FUNC;
986 #if ENABLE_HUSH_LOCAL
987 static int builtin_local(char **argv) FAST_FUNC;
989 #if ENABLE_HUSH_MEMLEAK
990 static int builtin_memleak(char **argv) FAST_FUNC;
992 #if ENABLE_HUSH_PRINTF
993 static int builtin_printf(char **argv) FAST_FUNC;
995 static int builtin_pwd(char **argv) FAST_FUNC;
997 static int builtin_read(char **argv) FAST_FUNC;
1000 static int builtin_set(char **argv) FAST_FUNC;
1002 static int builtin_shift(char **argv) FAST_FUNC;
1003 static int builtin_source(char **argv) FAST_FUNC;
1004 #if ENABLE_HUSH_TEST || BASH_TEST2
1005 static int builtin_test(char **argv) FAST_FUNC;
1007 #if ENABLE_HUSH_TRAP
1008 static int builtin_trap(char **argv) FAST_FUNC;
1010 #if ENABLE_HUSH_TYPE
1011 static int builtin_type(char **argv) FAST_FUNC;
1013 static int builtin_true(char **argv) FAST_FUNC;
1014 #if ENABLE_HUSH_UMASK
1015 static int builtin_umask(char **argv) FAST_FUNC;
1017 #if ENABLE_HUSH_UNSET
1018 static int builtin_unset(char **argv) FAST_FUNC;
1020 #if ENABLE_HUSH_KILL
1021 static int builtin_kill(char **argv) FAST_FUNC;
1023 #if ENABLE_HUSH_WAIT
1024 static int builtin_wait(char **argv) FAST_FUNC;
1026 #if ENABLE_HUSH_LOOPS
1027 static int builtin_break(char **argv) FAST_FUNC;
1028 static int builtin_continue(char **argv) FAST_FUNC;
1030 #if ENABLE_HUSH_FUNCTIONS
1031 static int builtin_return(char **argv) FAST_FUNC;
1034 /* Table of built-in functions. They can be forked or not, depending on
1035 * context: within pipes, they fork. As simple commands, they do not.
1036 * When used in non-forking context, they can change global variables
1037 * in the parent shell process. If forked, of course they cannot.
1038 * For example, 'unset foo | whatever' will parse and run, but foo will
1039 * still be set at the end. */
1040 struct built_in_command {
1042 int (*b_function)(char **argv) FAST_FUNC;
1043 #if ENABLE_HUSH_HELP
1044 const char *b_descr;
1045 # define BLTIN(cmd, func, help) { cmd, func, help }
1047 # define BLTIN(cmd, func, help) { cmd, func }
1051 static const struct built_in_command bltins1[] = {
1052 BLTIN("." , builtin_source , "Run commands in file"),
1053 BLTIN(":" , builtin_true , NULL),
1055 BLTIN("bg" , builtin_fg_bg , "Resume job in background"),
1057 #if ENABLE_HUSH_LOOPS
1058 BLTIN("break" , builtin_break , "Exit loop"),
1060 BLTIN("cd" , builtin_cd , "Change directory"),
1061 #if ENABLE_HUSH_LOOPS
1062 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
1064 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
1065 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
1066 BLTIN("exit" , builtin_exit , NULL),
1067 #if ENABLE_HUSH_EXPORT
1068 BLTIN("export" , builtin_export , "Set environment variables"),
1071 BLTIN("fg" , builtin_fg_bg , "Bring job to foreground"),
1073 #if ENABLE_HUSH_HELP
1074 BLTIN("help" , builtin_help , NULL),
1076 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
1077 BLTIN("history" , builtin_history , "Show history"),
1080 BLTIN("jobs" , builtin_jobs , "List jobs"),
1082 #if ENABLE_HUSH_KILL
1083 BLTIN("kill" , builtin_kill , "Send signals to processes"),
1085 #if ENABLE_HUSH_LOCAL
1086 BLTIN("local" , builtin_local , "Set local variables"),
1088 #if ENABLE_HUSH_MEMLEAK
1089 BLTIN("memleak" , builtin_memleak , NULL),
1091 #if ENABLE_HUSH_READ
1092 BLTIN("read" , builtin_read , "Input into variable"),
1094 #if ENABLE_HUSH_READONLY
1095 BLTIN("readonly" , builtin_readonly, "Make variables read-only"),
1097 #if ENABLE_HUSH_FUNCTIONS
1098 BLTIN("return" , builtin_return , "Return from function"),
1101 BLTIN("set" , builtin_set , "Set positional parameters"),
1103 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
1105 BLTIN("source" , builtin_source , NULL),
1107 #if ENABLE_HUSH_TRAP
1108 BLTIN("trap" , builtin_trap , "Trap signals"),
1110 BLTIN("true" , builtin_true , NULL),
1111 #if ENABLE_HUSH_TYPE
1112 BLTIN("type" , builtin_type , "Show command type"),
1114 #if ENABLE_HUSH_ULIMIT
1115 BLTIN("ulimit" , shell_builtin_ulimit, "Control resource limits"),
1117 #if ENABLE_HUSH_UMASK
1118 BLTIN("umask" , builtin_umask , "Set file creation mask"),
1120 #if ENABLE_HUSH_UNSET
1121 BLTIN("unset" , builtin_unset , "Unset variables"),
1123 #if ENABLE_HUSH_WAIT
1124 BLTIN("wait" , builtin_wait , "Wait for process to finish"),
1127 /* These builtins won't be used if we are on NOMMU and need to re-exec
1128 * (it's cheaper to run an external program in this case):
1130 static const struct built_in_command bltins2[] = {
1131 #if ENABLE_HUSH_TEST
1132 BLTIN("[" , builtin_test , NULL),
1135 BLTIN("[[" , builtin_test , NULL),
1137 #if ENABLE_HUSH_ECHO
1138 BLTIN("echo" , builtin_echo , NULL),
1140 #if ENABLE_HUSH_PRINTF
1141 BLTIN("printf" , builtin_printf , NULL),
1143 BLTIN("pwd" , builtin_pwd , NULL),
1144 #if ENABLE_HUSH_TEST
1145 BLTIN("test" , builtin_test , NULL),
1153 /* prevent disasters with G.debug_indent < 0 */
1154 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
1155 # define debug_enter() (G.debug_indent++)
1156 # define debug_leave() (G.debug_indent--)
1158 # define indent() ((void)0)
1159 # define debug_enter() ((void)0)
1160 # define debug_leave() ((void)0)
1163 #ifndef debug_printf
1164 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
1167 #ifndef debug_printf_parse
1168 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
1171 #ifndef debug_printf_exec
1172 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
1175 #ifndef debug_printf_env
1176 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
1179 #ifndef debug_printf_jobs
1180 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
1181 # define DEBUG_JOBS 1
1183 # define DEBUG_JOBS 0
1186 #ifndef debug_printf_expand
1187 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1188 # define DEBUG_EXPAND 1
1190 # define DEBUG_EXPAND 0
1193 #ifndef debug_printf_varexp
1194 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1197 #ifndef debug_printf_glob
1198 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1199 # define DEBUG_GLOB 1
1201 # define DEBUG_GLOB 0
1204 #ifndef debug_printf_redir
1205 # define debug_printf_redir(...) (indent(), fdprintf(2, __VA_ARGS__))
1208 #ifndef debug_printf_list
1209 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1212 #ifndef debug_printf_subst
1213 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1216 #ifndef debug_printf_clean
1217 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1218 # define DEBUG_CLEAN 1
1220 # define DEBUG_CLEAN 0
1224 static void debug_print_strings(const char *prefix, char **vv)
1227 fdprintf(2, "%s:\n", prefix);
1229 fdprintf(2, " '%s'\n", *vv++);
1232 # define debug_print_strings(prefix, vv) ((void)0)
1236 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1239 static void *xxmalloc(int lineno, size_t size)
1241 void *ptr = xmalloc((size + 0xff) & ~0xff);
1242 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1245 static void *xxrealloc(int lineno, void *ptr, size_t size)
1247 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1248 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1251 static char *xxstrdup(int lineno, const char *str)
1253 char *ptr = xstrdup(str);
1254 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1257 static void xxfree(void *ptr)
1259 fdprintf(2, "free %p\n", ptr);
1262 # define xmalloc(s) xxmalloc(__LINE__, s)
1263 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1264 # define xstrdup(s) xxstrdup(__LINE__, s)
1265 # define free(p) xxfree(p)
1269 /* Syntax and runtime errors. They always abort scripts.
1270 * In interactive use they usually discard unparsed and/or unexecuted commands
1271 * and return to the prompt.
1272 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1275 # define msg_and_die_if_script(lineno, ...) msg_and_die_if_script(__VA_ARGS__)
1276 # define syntax_error(lineno, msg) syntax_error(msg)
1277 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1278 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1279 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1280 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1283 static void die_if_script(void)
1285 if (!G_interactive_fd) {
1286 if (G.last_exitcode) /* sometines it's 2, not 1 (bash compat) */
1287 xfunc_error_retval = G.last_exitcode;
1292 static void msg_and_die_if_script(unsigned lineno, const char *fmt, ...)
1297 bb_error_msg("hush.c:%u", lineno);
1300 bb_verror_msg(fmt, p, NULL);
1305 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1308 bb_error_msg("syntax error: %s", msg);
1310 bb_error_msg("syntax error");
1314 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1316 bb_error_msg("syntax error at '%s'", msg);
1320 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1322 bb_error_msg("syntax error: unterminated %s", s);
1323 //? source4.tests fails: in bash, echo ${^} in script does not terminate the script
1327 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1329 char msg[2] = { ch, '\0' };
1330 syntax_error_unterm_str(lineno, msg);
1333 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1339 bb_error_msg("hush.c:%u", lineno);
1341 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1346 # undef msg_and_die_if_script
1347 # undef syntax_error
1348 # undef syntax_error_at
1349 # undef syntax_error_unterm_ch
1350 # undef syntax_error_unterm_str
1351 # undef syntax_error_unexpected_ch
1353 # define msg_and_die_if_script(...) msg_and_die_if_script(__LINE__, __VA_ARGS__)
1354 # define syntax_error(msg) syntax_error(__LINE__, msg)
1355 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1356 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1357 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1358 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1362 #if ENABLE_HUSH_INTERACTIVE
1363 static void cmdedit_update_prompt(void);
1365 # define cmdedit_update_prompt() ((void)0)
1369 /* Utility functions
1371 /* Replace each \x with x in place, return ptr past NUL. */
1372 static char *unbackslash(char *src)
1374 char *dst = src = strchrnul(src, '\\');
1378 if ((*dst++ = *src++) == '\0')
1384 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1405 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1406 v[count1 + count2] = NULL;
1409 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1413 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1415 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1416 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1419 #define add_strings_to_strings(strings, add, need_to_dup) \
1420 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1423 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1424 static char **add_string_to_strings(char **strings, char *add)
1429 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1432 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1434 char **ptr = add_string_to_strings(strings, add);
1435 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1438 #define add_string_to_strings(strings, add) \
1439 xx_add_string_to_strings(__LINE__, strings, add)
1442 static void free_strings(char **strings)
1456 static int fcntl_F_DUPFD(int fd, int avoid_fd)
1460 newfd = fcntl(fd, F_DUPFD, avoid_fd + 1);
1470 static int xdup_CLOEXEC_and_close(int fd, int avoid_fd)
1474 newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1);
1480 /* fd was not open? */
1485 if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */
1486 fcntl(newfd, F_SETFD, FD_CLOEXEC);
1492 /* Manipulating the list of open FILEs */
1493 static FILE *remember_FILE(FILE *fp)
1496 struct FILE_list *n = xmalloc(sizeof(*n));
1497 n->next = G.FILE_list;
1501 close_on_exec_on(n->fd);
1505 static void fclose_and_forget(FILE *fp)
1507 struct FILE_list **pp = &G.FILE_list;
1509 struct FILE_list *cur = *pp;
1510 if (cur->fp == fp) {
1519 static int save_FILEs_on_redirect(int fd, int avoid_fd)
1521 struct FILE_list *fl = G.FILE_list;
1524 /* We use it only on script files, they are all CLOEXEC */
1525 fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd);
1526 debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd);
1533 static void restore_redirected_FILEs(void)
1535 struct FILE_list *fl = G.FILE_list;
1537 int should_be = fileno(fl->fp);
1538 if (fl->fd != should_be) {
1539 debug_printf_redir("restoring script fd from %d to %d\n", fl->fd, should_be);
1540 xmove_fd(fl->fd, should_be);
1546 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
1547 static void close_all_FILE_list(void)
1549 struct FILE_list *fl = G.FILE_list;
1551 /* fclose would also free FILE object.
1552 * It is disastrous if we share memory with a vforked parent.
1553 * I'm not sure we never come here after vfork.
1554 * Therefore just close fd, nothing more.
1556 /*fclose(fl->fp); - unsafe */
1562 static int fd_in_FILEs(int fd)
1564 struct FILE_list *fl = G.FILE_list;
1574 /* Helpers for setting new $n and restoring them back
1576 typedef struct save_arg_t {
1580 IF_HUSH_SET(smallint sv_g_malloced;)
1583 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1585 sv->sv_argv0 = argv[0];
1586 sv->sv_g_argv = G.global_argv;
1587 sv->sv_g_argc = G.global_argc;
1588 IF_HUSH_SET(sv->sv_g_malloced = G.global_args_malloced;)
1590 argv[0] = G.global_argv[0]; /* retain $0 */
1591 G.global_argv = argv;
1592 IF_HUSH_SET(G.global_args_malloced = 0;)
1594 G.global_argc = 1 + string_array_len(argv + 1);
1597 static void restore_G_args(save_arg_t *sv, char **argv)
1600 if (G.global_args_malloced) {
1601 /* someone ran "set -- arg1 arg2 ...", undo */
1602 char **pp = G.global_argv;
1603 while (*++pp) /* note: does not free $0 */
1605 free(G.global_argv);
1608 argv[0] = sv->sv_argv0;
1609 G.global_argv = sv->sv_g_argv;
1610 G.global_argc = sv->sv_g_argc;
1611 IF_HUSH_SET(G.global_args_malloced = sv->sv_g_malloced;)
1615 /* Basic theory of signal handling in shell
1616 * ========================================
1617 * This does not describe what hush does, rather, it is current understanding
1618 * what it _should_ do. If it doesn't, it's a bug.
1619 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1621 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1622 * is finished or backgrounded. It is the same in interactive and
1623 * non-interactive shells, and is the same regardless of whether
1624 * a user trap handler is installed or a shell special one is in effect.
1625 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1626 * backgrounds (i.e. stops) or kills all members of currently running
1629 * Wait builtin is interruptible by signals for which user trap is set
1630 * or by SIGINT in interactive shell.
1632 * Trap handlers will execute even within trap handlers. (right?)
1634 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1635 * except for handlers set to '' (empty string).
1637 * If job control is off, backgrounded commands ("cmd &")
1638 * have SIGINT, SIGQUIT set to SIG_IGN.
1640 * Commands which are run in command substitution ("`cmd`")
1641 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1643 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1644 * by the shell from its parent.
1646 * Signals which differ from SIG_DFL action
1647 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1650 * SIGTERM (interactive): ignore
1651 * SIGHUP (interactive):
1652 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1653 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1654 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1655 * that all pipe members are stopped. Try this in bash:
1656 * while :; do :; done - ^Z does not background it
1657 * (while :; do :; done) - ^Z backgrounds it
1658 * SIGINT (interactive): wait for last pipe, ignore the rest
1659 * of the command line, show prompt. NB: ^C does not send SIGINT
1660 * to interactive shell while shell is waiting for a pipe,
1661 * since shell is bg'ed (is not in foreground process group).
1662 * Example 1: this waits 5 sec, but does not execute ls:
1663 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1664 * Example 2: this does not wait and does not execute ls:
1665 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1666 * Example 3: this does not wait 5 sec, but executes ls:
1667 * "sleep 5; ls -l" + press ^C
1668 * Example 4: this does not wait and does not execute ls:
1669 * "sleep 5 & wait; ls -l" + press ^C
1671 * (What happens to signals which are IGN on shell start?)
1672 * (What happens with signal mask on shell start?)
1674 * Old implementation
1675 * ==================
1676 * We use in-kernel pending signal mask to determine which signals were sent.
1677 * We block all signals which we don't want to take action immediately,
1678 * i.e. we block all signals which need to have special handling as described
1679 * above, and all signals which have traps set.
1680 * After each pipe execution, we extract any pending signals via sigtimedwait()
1683 * unsigned special_sig_mask: a mask of such "special" signals
1684 * sigset_t blocked_set: current blocked signal set
1687 * clear bit in blocked_set unless it is also in special_sig_mask
1688 * "trap 'cmd' SIGxxx":
1689 * set bit in blocked_set (even if 'cmd' is '')
1690 * after [v]fork, if we plan to be a shell:
1691 * unblock signals with special interactive handling
1692 * (child shell is not interactive),
1693 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1694 * after [v]fork, if we plan to exec:
1695 * POSIX says fork clears pending signal mask in child - no need to clear it.
1696 * Restore blocked signal set to one inherited by shell just prior to exec.
1698 * Note: as a result, we do not use signal handlers much. The only uses
1699 * are to count SIGCHLDs
1700 * and to restore tty pgrp on signal-induced exit.
1703 * Standard says "When a subshell is entered, traps that are not being ignored
1704 * are set to the default actions". bash interprets it so that traps which
1705 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1707 * Problem: the above approach makes it unwieldy to catch signals while
1708 * we are in read builtin, or while we read commands from stdin:
1709 * masked signals are not visible!
1711 * New implementation
1712 * ==================
1713 * We record each signal we are interested in by installing signal handler
1714 * for them - a bit like emulating kernel pending signal mask in userspace.
1715 * We are interested in: signals which need to have special handling
1716 * as described above, and all signals which have traps set.
1717 * Signals are recorded in pending_set.
1718 * After each pipe execution, we extract any pending signals
1721 * unsigned special_sig_mask: a mask of shell-special signals.
1722 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1723 * char *traps[sig] if trap for sig is set (even if it's '').
1724 * sigset_t pending_set: set of sigs we received.
1727 * if sig is in special_sig_mask, set handler back to:
1728 * record_pending_signo, or to IGN if it's a tty stop signal
1729 * if sig is in fatal_sig_mask, set handler back to sigexit.
1730 * else: set handler back to SIG_DFL
1731 * "trap 'cmd' SIGxxx":
1732 * set handler to record_pending_signo.
1734 * set handler to SIG_IGN.
1735 * after [v]fork, if we plan to be a shell:
1736 * set signals with special interactive handling to SIG_DFL
1737 * (because child shell is not interactive),
1738 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1739 * after [v]fork, if we plan to exec:
1740 * POSIX says fork clears pending signal mask in child - no need to clear it.
1742 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1743 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1746 * Standard says "When a subshell is entered, traps that are not being ignored
1747 * are set to the default actions". bash interprets it so that traps which
1748 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1751 SPECIAL_INTERACTIVE_SIGS = 0
1756 SPECIAL_JOBSTOP_SIGS = 0
1765 static void record_pending_signo(int sig)
1767 sigaddset(&G.pending_set, sig);
1768 #if ENABLE_HUSH_FAST
1769 if (sig == SIGCHLD) {
1771 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1776 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1778 struct sigaction old_sa;
1780 /* We could use signal() to install handlers... almost:
1781 * except that we need to mask ALL signals while handlers run.
1782 * I saw signal nesting in strace, race window isn't small.
1783 * SA_RESTART is also needed, but in Linux, signal()
1784 * sets SA_RESTART too.
1786 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1787 /* sigfillset(&G.sa.sa_mask); - already done */
1788 /* G.sa.sa_flags = SA_RESTART; - already done */
1789 G.sa.sa_handler = handler;
1790 sigaction(sig, &G.sa, &old_sa);
1791 return old_sa.sa_handler;
1794 static void hush_exit(int exitcode) NORETURN;
1796 static void restore_ttypgrp_and__exit(void) NORETURN;
1797 static void restore_ttypgrp_and__exit(void)
1799 /* xfunc has failed! die die die */
1800 /* no EXIT traps, this is an escape hatch! */
1802 hush_exit(xfunc_error_retval);
1807 /* Needed only on some libc:
1808 * It was observed that on exit(), fgetc'ed buffered data
1809 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1810 * With the net effect that even after fork(), not vfork(),
1811 * exit() in NOEXECed applet in "sh SCRIPT":
1812 * noexec_applet_here
1813 * echo END_OF_SCRIPT
1814 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1815 * This makes "echo END_OF_SCRIPT" executed twice.
1816 * Similar problems can be seen with msg_and_die_if_script() -> xfunc_die()
1817 * and in `cmd` handling.
1818 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1820 static void fflush_and__exit(void) NORETURN;
1821 static void fflush_and__exit(void)
1824 _exit(xfunc_error_retval);
1827 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1828 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1829 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1830 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1832 /* Restores tty foreground process group, and exits.
1833 * May be called as signal handler for fatal signal
1834 * (will resend signal to itself, producing correct exit state)
1835 * or called directly with -EXITCODE.
1836 * We also call it if xfunc is exiting.
1838 static void sigexit(int sig) NORETURN;
1839 static void sigexit(int sig)
1841 /* Careful: we can end up here after [v]fork. Do not restore
1842 * tty pgrp then, only top-level shell process does that */
1843 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1844 /* Disable all signals: job control, SIGPIPE, etc.
1845 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1847 sigprocmask_allsigs(SIG_BLOCK);
1848 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1851 /* Not a signal, just exit */
1855 kill_myself_with_sig(sig); /* does not return */
1859 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1860 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1864 static sighandler_t pick_sighandler(unsigned sig)
1866 sighandler_t handler = SIG_DFL;
1867 if (sig < sizeof(unsigned)*8) {
1868 unsigned sigmask = (1 << sig);
1872 if (G_fatal_sig_mask & sigmask)
1876 /* sig has special handling? */
1877 if (G.special_sig_mask & sigmask) {
1878 handler = record_pending_signo;
1879 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1880 * in order to ignore them: they will be raised
1881 * in an endless loop when we try to do some
1882 * terminal ioctls! We do have to _ignore_ these.
1884 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1891 /* Restores tty foreground process group, and exits. */
1892 static void hush_exit(int exitcode)
1894 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1895 save_history(G.line_input_state);
1899 if (G.exiting <= 0 && G_traps && G_traps[0] && G_traps[0][0]) {
1901 /* argv[0] is unused */
1902 argv[1] = G_traps[0];
1904 G.exiting = 1; /* prevent EXIT trap recursion */
1905 /* Note: G_traps[0] is not cleared!
1906 * "trap" will still show it, if executed
1911 #if ENABLE_FEATURE_CLEAN_UP
1913 struct variable *cur_var;
1914 if (G.cwd != bb_msg_unknown)
1916 cur_var = G.top_var;
1918 struct variable *tmp = cur_var;
1919 if (!cur_var->max_len)
1920 free(cur_var->varstr);
1921 cur_var = cur_var->next;
1929 sigexit(- (exitcode & 0xff));
1936 //TODO: return a mask of ALL handled sigs?
1937 static int check_and_run_traps(void)
1944 if (sigisemptyset(&G.pending_set))
1949 if (sigismember(&G.pending_set, sig)) {
1950 sigdelset(&G.pending_set, sig);
1953 } while (sig < NSIG);
1956 if (G_traps && G_traps[sig]) {
1957 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1958 if (G_traps[sig][0]) {
1959 /* We have user-defined handler */
1960 smalluint save_rcode;
1962 /* argv[0] is unused */
1963 argv[1] = G_traps[sig];
1965 save_rcode = G.last_exitcode;
1967 //FIXME: shouldn't it be set to 128 + sig instead?
1968 G.last_exitcode = save_rcode;
1970 } /* else: "" trap, ignoring signal */
1973 /* not a trap: special action */
1976 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1983 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1984 /* bash is observed to signal whole process groups,
1985 * not individual processes */
1986 for (job = G.job_list; job; job = job->next) {
1989 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1990 if (kill(- job->pgrp, SIGHUP) == 0)
1991 kill(- job->pgrp, SIGCONT);
1996 #if ENABLE_HUSH_FAST
1998 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
2000 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
2002 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2003 * This simplifies wait builtin a bit.
2007 default: /* ignored: */
2008 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
2009 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
2011 * We don't do 'last_sig = sig' here -> NOT returning this sig.
2012 * Example: wait is not interrupted by TERM
2013 * in interactive shell, because TERM is ignored.
2022 static const char *get_cwd(int force)
2024 if (force || G.cwd == NULL) {
2025 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
2026 * we must not try to free(bb_msg_unknown) */
2027 if (G.cwd == bb_msg_unknown)
2029 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
2031 G.cwd = bb_msg_unknown;
2038 * Shell and environment variable support
2040 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
2042 struct variable **pp;
2043 struct variable *cur;
2046 while ((cur = *pp) != NULL) {
2047 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
2054 static const char* FAST_FUNC get_local_var_value(const char *name)
2056 struct variable **vpp;
2057 unsigned len = strlen(name);
2059 if (G.expanded_assignments) {
2060 char **cpp = G.expanded_assignments;
2063 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
2064 return cp + len + 1;
2069 vpp = get_ptr_to_local_var(name, len);
2071 return (*vpp)->varstr + len + 1;
2073 if (strcmp(name, "PPID") == 0)
2074 return utoa(G.root_ppid);
2075 // bash compat: UID? EUID?
2076 #if ENABLE_HUSH_RANDOM_SUPPORT
2077 if (strcmp(name, "RANDOM") == 0)
2078 return utoa(next_random(&G.random_gen));
2083 /* str holds "NAME=VAL" and is expected to be malloced.
2084 * We take ownership of it.
2086 #define SETFLAG_EXPORT (1 << 0)
2087 #define SETFLAG_UNEXPORT (1 << 1)
2088 #define SETFLAG_MAKE_RO (1 << 2)
2089 #define SETFLAG_LOCAL_SHIFT 3
2090 static int set_local_var(char *str, unsigned flags)
2092 struct variable **var_pp;
2093 struct variable *cur;
2094 char *free_me = NULL;
2097 IF_HUSH_LOCAL(unsigned local_lvl = (flags >> SETFLAG_LOCAL_SHIFT);)
2099 eq_sign = strchr(str, '=');
2100 if (!eq_sign) { /* not expected to ever happen? */
2105 name_len = eq_sign - str + 1; /* including '=' */
2106 var_pp = &G.top_var;
2107 while ((cur = *var_pp) != NULL) {
2108 if (strncmp(cur->varstr, str, name_len) != 0) {
2109 var_pp = &cur->next;
2113 /* We found an existing var with this name */
2114 if (cur->flg_read_only) {
2115 bb_error_msg("%s: readonly variable", str);
2117 //NOTE: in bash, assignment in "export READONLY_VAR=Z" fails, and sets $?=1,
2118 //but export per se succeeds (does put the var in env). We don't mimic that.
2121 if (flags & SETFLAG_UNEXPORT) { // && cur->flg_export ?
2122 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
2127 #if ENABLE_HUSH_LOCAL
2128 if (cur->func_nest_level < local_lvl) {
2129 /* New variable is declared as local,
2130 * and existing one is global, or local
2131 * from enclosing function.
2132 * Remove and save old one: */
2133 *var_pp = cur->next;
2134 cur->next = *G.shadowed_vars_pp;
2135 *G.shadowed_vars_pp = cur;
2136 /* bash 3.2.33(1) and exported vars:
2138 * # f() { local z=a; env | grep ^z; }
2144 if (cur->flg_export)
2145 flags |= SETFLAG_EXPORT;
2149 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
2154 if (cur->max_len != 0) {
2155 if (cur->max_len >= strlen(str)) {
2156 /* This one is from startup env, reuse space */
2157 strcpy(cur->varstr, str);
2162 goto set_str_and_exp;
2164 /* max_len == 0 signifies "malloced" var, which we can
2165 * (and have to) free. But we can't free(cur->varstr) here:
2166 * if cur->flg_export is 1, it is in the environment.
2167 * We should either unsetenv+free, or wait until putenv,
2168 * then putenv(new)+free(old).
2170 free_me = cur->varstr;
2171 goto set_str_and_exp;
2174 /* Not found - create new variable struct */
2175 cur = xzalloc(sizeof(*cur));
2176 IF_HUSH_LOCAL(cur->func_nest_level = local_lvl;)
2177 cur->next = *var_pp;
2183 #if !BB_MMU || ENABLE_HUSH_READONLY
2184 if (flags & SETFLAG_MAKE_RO) {
2185 cur->flg_read_only = 1;
2188 if (flags & SETFLAG_EXPORT)
2189 cur->flg_export = 1;
2190 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2191 cmdedit_update_prompt();
2192 if (cur->flg_export) {
2193 if (flags & SETFLAG_UNEXPORT) {
2194 cur->flg_export = 0;
2195 /* unsetenv was already done */
2198 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
2199 i = putenv(cur->varstr);
2200 /* only now we can free old exported malloced string */
2209 /* Used at startup and after each cd */
2210 static void set_pwd_var(unsigned flag)
2212 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)), flag);
2215 static int unset_local_var_len(const char *name, int name_len)
2217 struct variable *cur;
2218 struct variable **var_pp;
2221 return EXIT_SUCCESS;
2222 var_pp = &G.top_var;
2223 while ((cur = *var_pp) != NULL) {
2224 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2225 if (cur->flg_read_only) {
2226 bb_error_msg("%s: readonly variable", name);
2227 return EXIT_FAILURE;
2229 *var_pp = cur->next;
2230 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2231 bb_unsetenv(cur->varstr);
2232 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2233 cmdedit_update_prompt();
2237 return EXIT_SUCCESS;
2239 var_pp = &cur->next;
2241 return EXIT_SUCCESS;
2244 #if ENABLE_HUSH_UNSET
2245 static int unset_local_var(const char *name)
2247 return unset_local_var_len(name, strlen(name));
2251 static void unset_vars(char **strings)
2259 const char *eq = strchrnul(*v, '=');
2260 unset_local_var_len(*v, (int)(eq - *v));
2266 #if BASH_HOSTNAME_VAR || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_READ
2267 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2269 char *var = xasprintf("%s=%s", name, val);
2270 set_local_var(var, /*flag:*/ 0);
2276 * Helpers for "var1=val1 var2=val2 cmd" feature
2278 static void add_vars(struct variable *var)
2280 struct variable *next;
2284 var->next = G.top_var;
2286 if (var->flg_export) {
2287 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2288 putenv(var->varstr);
2290 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2296 static struct variable *set_vars_and_save_old(char **strings)
2299 struct variable *old = NULL;
2305 struct variable *var_p;
2306 struct variable **var_pp;
2309 eq = strchr(*s, '=');
2311 var_pp = get_ptr_to_local_var(*s, eq - *s);
2314 if (var_p->flg_read_only) {
2316 bb_error_msg("%s: readonly variable", *s);
2318 * "VAR=V BLTIN" unsets VARs after BLTIN completes.
2319 * If VAR is readonly, leaving it in the list
2320 * after asssignment error (msg above)
2321 * causes doubled error message later, on unset.
2323 debug_printf_env("removing/freeing '%s' element\n", *s);
2326 do { *p = p[1]; p++; } while (*p);
2329 /* Remove variable from global linked list */
2330 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2331 *var_pp = var_p->next;
2332 /* Add it to returned list */
2336 set_local_var(*s, SETFLAG_EXPORT);
2348 static void reinit_unicode_for_hush(void)
2350 /* Unicode support should be activated even if LANG is set
2351 * _during_ shell execution, not only if it was set when
2352 * shell was started. Therefore, re-check LANG every time:
2354 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2355 || ENABLE_UNICODE_USING_LOCALE
2357 const char *s = get_local_var_value("LC_ALL");
2358 if (!s) s = get_local_var_value("LC_CTYPE");
2359 if (!s) s = get_local_var_value("LANG");
2365 * in_str support (strings, and "strings" read from files).
2368 #if ENABLE_HUSH_INTERACTIVE
2369 /* To test correct lineedit/interactive behavior, type from command line:
2375 * It exercises a lot of corner cases.
2377 static void cmdedit_update_prompt(void)
2379 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2380 G.PS1 = get_local_var_value("PS1");
2383 G.PS2 = get_local_var_value("PS2");
2390 static const char *setup_prompt_string(int promptmode)
2392 const char *prompt_str;
2393 debug_printf("setup_prompt_string %d ", promptmode);
2394 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2395 /* Set up the prompt */
2396 if (promptmode == 0) { /* PS1 */
2398 /* bash uses $PWD value, even if it is set by user.
2399 * It uses current dir only if PWD is unset.
2400 * We always use current dir. */
2401 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2406 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2407 debug_printf("prompt_str '%s'\n", prompt_str);
2410 static int get_user_input(struct in_str *i)
2413 const char *prompt_str;
2415 prompt_str = setup_prompt_string(i->promptmode);
2416 # if ENABLE_FEATURE_EDITING
2418 reinit_unicode_for_hush();
2419 if (G.flag_SIGINT) {
2420 /* There was ^C'ed, make it look prettier: */
2424 /* buglet: SIGINT will not make new prompt to appear _at once_,
2425 * only after <Enter>. (^C works immediately) */
2426 r = read_line_input(G.line_input_state, prompt_str,
2427 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1
2429 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2432 check_and_run_traps();
2433 if (r != 0 && !G.flag_SIGINT)
2435 /* ^C or SIGINT: repeat */
2436 /* bash prints ^C even on real SIGINT (non-kbd generated) */
2437 write(STDOUT_FILENO, "^C", 2);
2438 G.last_exitcode = 128 + SIGINT;
2441 /* EOF/error detected */
2443 i->peek_buf[0] = r = EOF;
2446 i->p = G.user_input_buf;
2447 return (unsigned char)*i->p++;
2451 if (i->last_char == '\0' || i->last_char == '\n') {
2452 /* Why check_and_run_traps here? Try this interactively:
2453 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2454 * $ <[enter], repeatedly...>
2455 * Without check_and_run_traps, handler never runs.
2457 check_and_run_traps();
2458 fputs(prompt_str, stdout);
2461 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2463 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2464 * no ^C masking happens during fgetc, no special code for ^C:
2465 * it generates SIGINT as usual.
2467 check_and_run_traps();
2469 G.last_exitcode = 128 + SIGINT;
2476 /* This is the magic location that prints prompts
2477 * and gets data back from the user */
2478 static int fgetc_interactive(struct in_str *i)
2481 /* If it's interactive stdin, get new line. */
2482 if (G_interactive_fd && i->file == stdin) {
2483 /* Returns first char (or EOF), the rest is in i->p[] */
2484 ch = get_user_input(i);
2485 i->promptmode = 1; /* PS2 */
2487 /* Not stdin: script file, sourced file, etc */
2488 do ch = fgetc(i->file); while (ch == '\0');
2493 static inline int fgetc_interactive(struct in_str *i)
2496 do ch = fgetc(i->file); while (ch == '\0');
2499 #endif /* INTERACTIVE */
2501 static int i_getch(struct in_str *i)
2506 /* string-based in_str */
2507 ch = (unsigned char)*i->p;
2516 /* FILE-based in_str */
2518 #if ENABLE_FEATURE_EDITING
2519 /* This can be stdin, check line editing char[] buffer */
2520 if (i->p && *i->p != '\0') {
2521 ch = (unsigned char)*i->p++;
2525 /* peek_buf[] is an int array, not char. Can contain EOF. */
2526 ch = i->peek_buf[0];
2528 int ch2 = i->peek_buf[1];
2529 i->peek_buf[0] = ch2;
2530 if (ch2 == 0) /* very likely, avoid redundant write */
2536 ch = fgetc_interactive(i);
2538 debug_printf("file_get: got '%c' %d\n", ch, ch);
2543 static int i_peek(struct in_str *i)
2548 /* string-based in_str */
2549 /* Doesn't report EOF on NUL. None of the callers care. */
2550 return (unsigned char)*i->p;
2553 /* FILE-based in_str */
2555 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2556 /* This can be stdin, check line editing char[] buffer */
2557 if (i->p && *i->p != '\0')
2558 return (unsigned char)*i->p;
2560 /* peek_buf[] is an int array, not char. Can contain EOF. */
2561 ch = i->peek_buf[0];
2565 /* Need to get a new char */
2566 ch = fgetc_interactive(i);
2567 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2569 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2570 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2576 i->peek_buf[0] = ch;
2577 /*i->peek_buf[1] = 0; - already is */
2581 /* Only ever called if i_peek() was called, and did not return EOF.
2582 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2583 * not end-of-line. Therefore we never need to read a new editing line here.
2585 static int i_peek2(struct in_str *i)
2589 /* There are two cases when i->p[] buffer exists.
2590 * (1) it's a string in_str.
2591 * (2) It's a file, and we have a saved line editing buffer.
2592 * In both cases, we know that i->p[0] exists and not NUL, and
2593 * the peek2 result is in i->p[1].
2596 return (unsigned char)i->p[1];
2598 /* Now we know it is a file-based in_str. */
2600 /* peek_buf[] is an int array, not char. Can contain EOF. */
2601 /* Is there 2nd char? */
2602 ch = i->peek_buf[1];
2604 /* We did not read it yet, get it now */
2605 do ch = fgetc(i->file); while (ch == '\0');
2606 i->peek_buf[1] = ch;
2609 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2613 static void setup_file_in_str(struct in_str *i, FILE *f)
2615 memset(i, 0, sizeof(*i));
2616 /* i->promptmode = 0; - PS1 (memset did it) */
2621 static void setup_string_in_str(struct in_str *i, const char *s)
2623 memset(i, 0, sizeof(*i));
2624 /* i->promptmode = 0; - PS1 (memset did it) */
2625 /*i->file = NULL */;
2633 #define B_CHUNK (32 * sizeof(char*))
2635 static void o_reset_to_empty_unquoted(o_string *o)
2638 o->has_quoted_part = 0;
2643 static void o_free(o_string *o)
2646 memset(o, 0, sizeof(*o));
2649 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2654 static void o_grow_by(o_string *o, int len)
2656 if (o->length + len > o->maxlen) {
2657 o->maxlen += (2 * len) | (B_CHUNK-1);
2658 o->data = xrealloc(o->data, 1 + o->maxlen);
2662 static void o_addchr(o_string *o, int ch)
2664 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2665 if (o->length < o->maxlen) {
2666 /* likely. avoid o_grow_by() call */
2668 o->data[o->length] = ch;
2670 o->data[o->length] = '\0';
2678 /* Valid only if we know o_string is not empty */
2679 static void o_delchr(o_string *o)
2682 o->data[o->length] = '\0';
2686 static void o_addblock(o_string *o, const char *str, int len)
2689 ((char*)mempcpy(&o->data[o->length], str, len))[0] = '\0';
2693 static void o_addstr(o_string *o, const char *str)
2695 o_addblock(o, str, strlen(str));
2699 static void nommu_addchr(o_string *o, int ch)
2705 # define nommu_addchr(o, str) ((void)0)
2708 static void o_addstr_with_NUL(o_string *o, const char *str)
2710 o_addblock(o, str, strlen(str) + 1);
2714 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2715 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2716 * Apparently, on unquoted $v bash still does globbing
2717 * ("v='*.txt'; echo $v" prints all .txt files),
2718 * but NOT brace expansion! Thus, there should be TWO independent
2719 * quoting mechanisms on $v expansion side: one protects
2720 * $v from brace expansion, and other additionally protects "$v" against globbing.
2721 * We have only second one.
2724 #if ENABLE_HUSH_BRACE_EXPANSION
2725 # define MAYBE_BRACES "{}"
2727 # define MAYBE_BRACES ""
2730 /* My analysis of quoting semantics tells me that state information
2731 * is associated with a destination, not a source.
2733 static void o_addqchr(o_string *o, int ch)
2736 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2741 o->data[o->length] = '\\';
2744 o->data[o->length] = ch;
2746 o->data[o->length] = '\0';
2749 static void o_addQchr(o_string *o, int ch)
2752 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2753 && strchr("*?[\\" MAYBE_BRACES, ch)
2756 o->data[o->length] = '\\';
2760 o->data[o->length] = ch;
2762 o->data[o->length] = '\0';
2765 static void o_addqblock(o_string *o, const char *str, int len)
2770 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2771 if (ordinary_cnt > len) /* paranoia */
2773 o_addblock(o, str, ordinary_cnt);
2774 if (ordinary_cnt == len)
2775 return; /* NUL is already added by o_addblock */
2776 str += ordinary_cnt;
2777 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2781 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2783 o->data[o->length] = '\\';
2787 o->data[o->length] = ch;
2790 o->data[o->length] = '\0';
2793 static void o_addQblock(o_string *o, const char *str, int len)
2795 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2796 o_addblock(o, str, len);
2799 o_addqblock(o, str, len);
2802 static void o_addQstr(o_string *o, const char *str)
2804 o_addQblock(o, str, strlen(str));
2807 /* A special kind of o_string for $VAR and `cmd` expansion.
2808 * It contains char* list[] at the beginning, which is grown in 16 element
2809 * increments. Actual string data starts at the next multiple of 16 * (char*).
2810 * list[i] contains an INDEX (int!) into this string data.
2811 * It means that if list[] needs to grow, data needs to be moved higher up
2812 * but list[i]'s need not be modified.
2813 * NB: remembering how many list[i]'s you have there is crucial.
2814 * o_finalize_list() operation post-processes this structure - calculates
2815 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2817 #if DEBUG_EXPAND || DEBUG_GLOB
2818 static void debug_print_list(const char *prefix, o_string *o, int n)
2820 char **list = (char**)o->data;
2821 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2825 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2826 prefix, list, n, string_start, o->length, o->maxlen,
2827 !!(o->o_expflags & EXP_FLAG_GLOB),
2829 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2832 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2833 o->data + (int)(uintptr_t)list[i] + string_start,
2834 o->data + (int)(uintptr_t)list[i] + string_start);
2838 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2840 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2844 # define debug_print_list(prefix, o, n) ((void)0)
2847 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2848 * in list[n] so that it points past last stored byte so far.
2849 * It returns n+1. */
2850 static int o_save_ptr_helper(o_string *o, int n)
2852 char **list = (char**)o->data;
2856 if (!o->has_empty_slot) {
2857 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2858 string_len = o->length - string_start;
2859 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2860 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2861 /* list[n] points to string_start, make space for 16 more pointers */
2862 o->maxlen += 0x10 * sizeof(list[0]);
2863 o->data = xrealloc(o->data, o->maxlen + 1);
2864 list = (char**)o->data;
2865 memmove(list + n + 0x10, list + n, string_len);
2866 o->length += 0x10 * sizeof(list[0]);
2868 debug_printf_list("list[%d]=%d string_start=%d\n",
2869 n, string_len, string_start);
2872 /* We have empty slot at list[n], reuse without growth */
2873 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2874 string_len = o->length - string_start;
2875 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2876 n, string_len, string_start);
2877 o->has_empty_slot = 0;
2879 o->has_quoted_part = 0;
2880 list[n] = (char*)(uintptr_t)string_len;
2884 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2885 static int o_get_last_ptr(o_string *o, int n)
2887 char **list = (char**)o->data;
2888 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2890 return ((int)(uintptr_t)list[n-1]) + string_start;
2893 #if ENABLE_HUSH_BRACE_EXPANSION
2894 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2895 * first, it processes even {a} (no commas), second,
2896 * I didn't manage to make it return strings when they don't match
2897 * existing files. Need to re-implement it.
2901 static int glob_needed(const char *s)
2910 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2916 /* Return pointer to next closing brace or to comma */
2917 static const char *next_brace_sub(const char *cp)
2921 while (*cp != '\0') {
2928 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2934 return *cp != '\0' ? cp : NULL;
2936 /* Recursive brace globber. Note: may garble pattern[]. */
2937 static int glob_brace(char *pattern, o_string *o, int n)
2939 char *new_pattern_buf;
2946 debug_printf_glob("glob_brace('%s')\n", pattern);
2952 if (*begin == '{') {
2953 /* Find the first sub-pattern and at the same time
2954 * find the rest after the closing brace */
2955 next = next_brace_sub(begin);
2957 /* An illegal expression */
2961 /* "{abc}" with no commas - illegal
2962 * brace expr, disregard and skip it */
2968 if (*begin == '\\' && begin[1] != '\0')
2972 debug_printf_glob("begin:%s\n", begin);
2973 debug_printf_glob("next:%s\n", next);
2975 /* Now find the end of the whole brace expression */
2977 while (*rest != '}') {
2978 rest = next_brace_sub(rest);
2980 /* An illegal expression */
2983 debug_printf_glob("rest:%s\n", rest);
2985 rest_len = strlen(++rest) + 1;
2987 /* We are sure the brace expression is well-formed */
2989 /* Allocate working buffer large enough for our work */
2990 new_pattern_buf = xmalloc(strlen(pattern));
2992 /* We have a brace expression. BEGIN points to the opening {,
2993 * NEXT points past the terminator of the first element, and REST
2994 * points past the final }. We will accumulate result names from
2995 * recursive runs for each brace alternative in the buffer using
3000 /* Construct the new glob expression */
3003 mempcpy(new_pattern_buf,
3004 /* We know the prefix for all sub-patterns */
3005 pattern, begin - pattern),
3009 /* Note: glob_brace() may garble new_pattern_buf[].
3010 * That's why we re-copy prefix every time (1st memcpy above).
3012 n = glob_brace(new_pattern_buf, o, n);
3014 /* We saw the last entry */
3018 next = next_brace_sub(next);
3020 free(new_pattern_buf);
3028 memset(&globdata, 0, sizeof(globdata));
3029 gr = glob(pattern, 0, NULL, &globdata);
3030 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3032 if (gr == GLOB_NOMATCH) {
3033 globfree(&globdata);
3034 /* NB: garbles parameter */
3035 unbackslash(pattern);
3036 o_addstr_with_NUL(o, pattern);
3037 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3038 return o_save_ptr_helper(o, n);
3040 if (gr == GLOB_NOSPACE)
3041 bb_error_msg_and_die(bb_msg_memory_exhausted);
3042 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3043 * but we didn't specify it. Paranoia again. */
3044 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3046 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3047 char **argv = globdata.gl_pathv;
3049 o_addstr_with_NUL(o, *argv);
3050 n = o_save_ptr_helper(o, n);
3056 globfree(&globdata);
3060 /* Performs globbing on last list[],
3061 * saving each result as a new list[].
3063 static int perform_glob(o_string *o, int n)
3065 char *pattern, *copy;
3067 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3069 return o_save_ptr_helper(o, n);
3070 pattern = o->data + o_get_last_ptr(o, n);
3071 debug_printf_glob("glob pattern '%s'\n", pattern);
3072 if (!glob_needed(pattern)) {
3073 /* unbackslash last string in o in place, fix length */
3074 o->length = unbackslash(pattern) - o->data;
3075 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3076 return o_save_ptr_helper(o, n);
3079 copy = xstrdup(pattern);
3080 /* "forget" pattern in o */
3081 o->length = pattern - o->data;
3082 n = glob_brace(copy, o, n);
3085 debug_print_list("perform_glob returning", o, n);
3089 #else /* !HUSH_BRACE_EXPANSION */
3092 static int glob_needed(const char *s)
3101 if (*s == '*' || *s == '[' || *s == '?')
3107 /* Performs globbing on last list[],
3108 * saving each result as a new list[].
3110 static int perform_glob(o_string *o, int n)
3116 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
3118 return o_save_ptr_helper(o, n);
3119 pattern = o->data + o_get_last_ptr(o, n);
3120 debug_printf_glob("glob pattern '%s'\n", pattern);
3121 if (!glob_needed(pattern)) {
3123 /* unbackslash last string in o in place, fix length */
3124 o->length = unbackslash(pattern) - o->data;
3125 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
3126 return o_save_ptr_helper(o, n);
3129 memset(&globdata, 0, sizeof(globdata));
3130 /* Can't use GLOB_NOCHECK: it does not unescape the string.
3131 * If we glob "*.\*" and don't find anything, we need
3132 * to fall back to using literal "*.*", but GLOB_NOCHECK
3133 * will return "*.\*"!
3135 gr = glob(pattern, 0, NULL, &globdata);
3136 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
3138 if (gr == GLOB_NOMATCH) {
3139 globfree(&globdata);
3142 if (gr == GLOB_NOSPACE)
3143 bb_error_msg_and_die(bb_msg_memory_exhausted);
3144 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
3145 * but we didn't specify it. Paranoia again. */
3146 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
3148 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
3149 char **argv = globdata.gl_pathv;
3150 /* "forget" pattern in o */
3151 o->length = pattern - o->data;
3153 o_addstr_with_NUL(o, *argv);
3154 n = o_save_ptr_helper(o, n);
3160 globfree(&globdata);
3162 debug_print_list("perform_glob returning", o, n);
3166 #endif /* !HUSH_BRACE_EXPANSION */
3168 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
3169 * Otherwise, just finish current list[] and start new */
3170 static int o_save_ptr(o_string *o, int n)
3172 if (o->o_expflags & EXP_FLAG_GLOB) {
3173 /* If o->has_empty_slot, list[n] was already globbed
3174 * (if it was requested back then when it was filled)
3175 * so don't do that again! */
3176 if (!o->has_empty_slot)
3177 return perform_glob(o, n); /* o_save_ptr_helper is inside */
3179 return o_save_ptr_helper(o, n);
3182 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
3183 static char **o_finalize_list(o_string *o, int n)
3188 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
3190 debug_print_list("finalized", o, n);
3191 debug_printf_expand("finalized n:%d\n", n);
3192 list = (char**)o->data;
3193 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
3197 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
3202 static void free_pipe_list(struct pipe *pi);
3204 /* Returns pi->next - next pipe in the list */
3205 static struct pipe *free_pipe(struct pipe *pi)
3210 debug_printf_clean("free_pipe (pid %d)\n", getpid());
3211 for (i = 0; i < pi->num_cmds; i++) {
3212 struct command *command;
3213 struct redir_struct *r, *rnext;
3215 command = &pi->cmds[i];
3216 debug_printf_clean(" command %d:\n", i);
3217 if (command->argv) {
3221 for (a = 0, p = command->argv; *p; a++, p++) {
3222 debug_printf_clean(" argv[%d] = %s\n", a, *p);
3225 free_strings(command->argv);
3226 //command->argv = NULL;
3228 /* not "else if": on syntax error, we may have both! */
3229 if (command->group) {
3230 debug_printf_clean(" begin group (cmd_type:%d)\n",
3232 free_pipe_list(command->group);
3233 debug_printf_clean(" end group\n");
3234 //command->group = NULL;
3236 /* else is crucial here.
3237 * If group != NULL, child_func is meaningless */
3238 #if ENABLE_HUSH_FUNCTIONS
3239 else if (command->child_func) {
3240 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3241 command->child_func->parent_cmd = NULL;
3245 free(command->group_as_string);
3246 //command->group_as_string = NULL;
3248 for (r = command->redirects; r; r = rnext) {
3249 debug_printf_clean(" redirect %d%s",
3250 r->rd_fd, redir_table[r->rd_type].descrip);
3251 /* guard against the case >$FOO, where foo is unset or blank */
3252 if (r->rd_filename) {
3253 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3254 free(r->rd_filename);
3255 //r->rd_filename = NULL;
3257 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3261 //command->redirects = NULL;
3263 free(pi->cmds); /* children are an array, they get freed all at once */
3267 //pi->cmdtext = NULL;
3275 static void free_pipe_list(struct pipe *pi)
3279 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3281 debug_printf_clean("pipe followup code %d\n", pi->followup);
3287 /*** Parsing routines ***/
3289 #ifndef debug_print_tree
3290 static void debug_print_tree(struct pipe *pi, int lvl)
3292 static const char *const PIPE[] = {
3298 static const char *RES[] = {
3299 [RES_NONE ] = "NONE" ,
3302 [RES_THEN ] = "THEN" ,
3303 [RES_ELIF ] = "ELIF" ,
3304 [RES_ELSE ] = "ELSE" ,
3307 # if ENABLE_HUSH_LOOPS
3308 [RES_FOR ] = "FOR" ,
3309 [RES_WHILE] = "WHILE",
3310 [RES_UNTIL] = "UNTIL",
3312 [RES_DONE ] = "DONE" ,
3314 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3317 # if ENABLE_HUSH_CASE
3318 [RES_CASE ] = "CASE" ,
3319 [RES_CASE_IN ] = "CASE_IN" ,
3320 [RES_MATCH] = "MATCH",
3321 [RES_CASE_BODY] = "CASE_BODY",
3322 [RES_ESAC ] = "ESAC" ,
3324 [RES_XXXX ] = "XXXX" ,
3325 [RES_SNTX ] = "SNTX" ,
3327 static const char *const CMDTYPE[] = {
3331 # if ENABLE_HUSH_FUNCTIONS
3340 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3341 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3343 while (prn < pi->num_cmds) {
3344 struct command *command = &pi->cmds[prn];
3345 char **argv = command->argv;
3347 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3349 command->assignment_cnt);
3350 if (command->group) {
3351 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3352 CMDTYPE[command->cmd_type],
3355 , " group_as_string:", command->group_as_string
3360 debug_print_tree(command->group, lvl+1);
3364 if (argv) while (*argv) {
3365 fdprintf(2, " '%s'", *argv);
3375 #endif /* debug_print_tree */
3377 static struct pipe *new_pipe(void)
3380 pi = xzalloc(sizeof(struct pipe));
3381 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3385 /* Command (member of a pipe) is complete, or we start a new pipe
3386 * if ctx->command is NULL.
3387 * No errors possible here.
3389 static int done_command(struct parse_context *ctx)
3391 /* The command is really already in the pipe structure, so
3392 * advance the pipe counter and make a new, null command. */
3393 struct pipe *pi = ctx->pipe;
3394 struct command *command = ctx->command;
3396 #if 0 /* Instead we emit error message at run time */
3397 if (ctx->pending_redirect) {
3398 /* For example, "cmd >" (no filename to redirect to) */
3399 syntax_error("invalid redirect");
3400 ctx->pending_redirect = NULL;
3405 if (IS_NULL_CMD(command)) {
3406 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3410 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3411 //debug_print_tree(ctx->list_head, 20);
3413 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3416 /* Only real trickiness here is that the uncommitted
3417 * command structure is not counted in pi->num_cmds. */
3418 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3419 ctx->command = command = &pi->cmds[pi->num_cmds];
3421 memset(command, 0, sizeof(*command));
3422 return pi->num_cmds; /* used only for 0/nonzero check */
3425 static void done_pipe(struct parse_context *ctx, pipe_style type)
3429 debug_printf_parse("done_pipe entered, followup %d\n", type);
3430 /* Close previous command */
3431 not_null = done_command(ctx);
3433 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3434 ctx->ctx_inverted = 0;
3435 ctx->pipe->res_word = ctx->ctx_res_w;
3437 if (type == PIPE_BG && ctx->list_head != ctx->pipe) {
3438 /* Necessary since && and || have precedence over &:
3439 * "cmd1 && cmd2 &" must spawn both cmds, not only cmd2,
3440 * in a backgrounded subshell.
3443 struct command *command;
3445 /* Is this actually this construct, all pipes end with && or ||? */
3446 pi = ctx->list_head;
3447 while (pi != ctx->pipe) {
3448 if (pi->followup != PIPE_AND && pi->followup != PIPE_OR)
3453 debug_printf_parse("BG with more than one pipe, converting to { p1 &&...pN; } &\n");
3454 pi->followup = PIPE_SEQ; /* close pN _not_ with "&"! */
3455 pi = xzalloc(sizeof(*pi));
3456 pi->followup = PIPE_BG;
3458 pi->cmds = xzalloc(sizeof(pi->cmds[0]));
3459 command = &pi->cmds[0];
3460 if (CMD_NORMAL != 0) /* "if xzalloc didn't do that already" */
3461 command->cmd_type = CMD_NORMAL;
3462 command->group = ctx->list_head;
3464 command->group_as_string = xstrndup(
3465 ctx->as_string.data,
3466 ctx->as_string.length - 1 /* do not copy last char, "&" */
3469 /* Replace all pipes in ctx with one newly created */
3470 ctx->list_head = ctx->pipe = pi;
3473 ctx->pipe->followup = type;
3476 /* Without this check, even just <enter> on command line generates
3477 * tree of three NOPs (!). Which is harmless but annoying.
3478 * IOW: it is safe to do it unconditionally. */
3481 || ctx->ctx_res_w == RES_FI
3483 #if ENABLE_HUSH_LOOPS
3484 || ctx->ctx_res_w == RES_DONE
3485 || ctx->ctx_res_w == RES_FOR
3486 || ctx->ctx_res_w == RES_IN
3488 #if ENABLE_HUSH_CASE
3489 || ctx->ctx_res_w == RES_ESAC
3493 debug_printf_parse("done_pipe: adding new pipe: "
3494 "not_null:%d ctx->ctx_res_w:%d\n",
3495 not_null, ctx->ctx_res_w);
3497 ctx->pipe->next = new_p;
3499 /* RES_THEN, RES_DO etc are "sticky" -
3500 * they remain set for pipes inside if/while.
3501 * This is used to control execution.
3502 * RES_FOR and RES_IN are NOT sticky (needed to support
3503 * cases where variable or value happens to match a keyword):
3505 #if ENABLE_HUSH_LOOPS
3506 if (ctx->ctx_res_w == RES_FOR
3507 || ctx->ctx_res_w == RES_IN)
3508 ctx->ctx_res_w = RES_NONE;
3510 #if ENABLE_HUSH_CASE
3511 if (ctx->ctx_res_w == RES_MATCH)
3512 ctx->ctx_res_w = RES_CASE_BODY;
3513 if (ctx->ctx_res_w == RES_CASE)
3514 ctx->ctx_res_w = RES_CASE_IN;
3516 ctx->command = NULL; /* trick done_command below */
3517 /* Create the memory for command, roughly:
3518 * ctx->pipe->cmds = new struct command;
3519 * ctx->command = &ctx->pipe->cmds[0];
3522 //debug_print_tree(ctx->list_head, 10);
3524 debug_printf_parse("done_pipe return\n");
3527 static void initialize_context(struct parse_context *ctx)
3529 memset(ctx, 0, sizeof(*ctx));
3530 ctx->pipe = ctx->list_head = new_pipe();
3531 /* Create the memory for command, roughly:
3532 * ctx->pipe->cmds = new struct command;
3533 * ctx->command = &ctx->pipe->cmds[0];
3538 /* If a reserved word is found and processed, parse context is modified
3539 * and 1 is returned.
3542 struct reserved_combo {
3545 unsigned char assignment_flag;
3549 FLAG_END = (1 << RES_NONE ),
3551 FLAG_IF = (1 << RES_IF ),
3552 FLAG_THEN = (1 << RES_THEN ),
3553 FLAG_ELIF = (1 << RES_ELIF ),
3554 FLAG_ELSE = (1 << RES_ELSE ),
3555 FLAG_FI = (1 << RES_FI ),
3557 # if ENABLE_HUSH_LOOPS
3558 FLAG_FOR = (1 << RES_FOR ),
3559 FLAG_WHILE = (1 << RES_WHILE),
3560 FLAG_UNTIL = (1 << RES_UNTIL),
3561 FLAG_DO = (1 << RES_DO ),
3562 FLAG_DONE = (1 << RES_DONE ),
3563 FLAG_IN = (1 << RES_IN ),
3565 # if ENABLE_HUSH_CASE
3566 FLAG_MATCH = (1 << RES_MATCH),
3567 FLAG_ESAC = (1 << RES_ESAC ),
3569 FLAG_START = (1 << RES_XXXX ),
3572 static const struct reserved_combo* match_reserved_word(o_string *word)
3574 /* Mostly a list of accepted follow-up reserved words.
3575 * FLAG_END means we are done with the sequence, and are ready
3576 * to turn the compound list into a command.
3577 * FLAG_START means the word must start a new compound list.
3579 static const struct reserved_combo reserved_list[] = {
3581 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3582 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3583 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3584 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3585 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3586 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3588 # if ENABLE_HUSH_LOOPS
3589 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3590 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3591 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3592 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3593 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3594 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3596 # if ENABLE_HUSH_CASE
3597 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3598 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3601 const struct reserved_combo *r;
3603 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3604 if (strcmp(word->data, r->literal) == 0)
3609 /* Return 0: not a keyword, 1: keyword
3611 static int reserved_word(o_string *word, struct parse_context *ctx)
3613 # if ENABLE_HUSH_CASE
3614 static const struct reserved_combo reserved_match = {
3615 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3618 const struct reserved_combo *r;
3620 if (word->has_quoted_part)
3622 r = match_reserved_word(word);
3626 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3627 # if ENABLE_HUSH_CASE
3628 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3629 /* "case word IN ..." - IN part starts first MATCH part */
3630 r = &reserved_match;
3633 if (r->flag == 0) { /* '!' */
3634 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3635 syntax_error("! ! command");
3636 ctx->ctx_res_w = RES_SNTX;
3638 ctx->ctx_inverted = 1;
3641 if (r->flag & FLAG_START) {
3642 struct parse_context *old;
3644 old = xmemdup(ctx, sizeof(*ctx));
3645 debug_printf_parse("push stack %p\n", old);
3646 initialize_context(ctx);
3648 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3649 syntax_error_at(word->data);
3650 ctx->ctx_res_w = RES_SNTX;
3653 /* "{...} fi" is ok. "{...} if" is not
3655 * if { echo foo; } then { echo bar; } fi */
3656 if (ctx->command->group)
3657 done_pipe(ctx, PIPE_SEQ);
3660 ctx->ctx_res_w = r->res;
3661 ctx->old_flag = r->flag;
3662 word->o_assignment = r->assignment_flag;
3663 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3665 if (ctx->old_flag & FLAG_END) {
3666 struct parse_context *old;
3668 done_pipe(ctx, PIPE_SEQ);
3669 debug_printf_parse("pop stack %p\n", ctx->stack);
3671 old->command->group = ctx->list_head;
3672 old->command->cmd_type = CMD_NORMAL;
3674 /* At this point, the compound command's string is in
3675 * ctx->as_string... except for the leading keyword!
3676 * Consider this example: "echo a | if true; then echo a; fi"
3677 * ctx->as_string will contain "true; then echo a; fi",
3678 * with "if " remaining in old->as_string!
3682 int len = old->as_string.length;
3683 /* Concatenate halves */
3684 o_addstr(&old->as_string, ctx->as_string.data);
3685 o_free_unsafe(&ctx->as_string);
3686 /* Find where leading keyword starts in first half */
3687 str = old->as_string.data + len;
3688 if (str > old->as_string.data)
3689 str--; /* skip whitespace after keyword */
3690 while (str > old->as_string.data && isalpha(str[-1]))
3692 /* Ugh, we're done with this horrid hack */
3693 old->command->group_as_string = xstrdup(str);
3694 debug_printf_parse("pop, remembering as:'%s'\n",
3695 old->command->group_as_string);
3698 *ctx = *old; /* physical copy */
3703 #endif /* HAS_KEYWORDS */
3705 /* Word is complete, look at it and update parsing context.
3706 * Normal return is 0. Syntax errors return 1.
3707 * Note: on return, word is reset, but not o_free'd!
3709 static int done_word(o_string *word, struct parse_context *ctx)
3711 struct command *command = ctx->command;
3713 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3714 if (word->length == 0 && !word->has_quoted_part) {
3715 debug_printf_parse("done_word return 0: true null, ignored\n");
3719 if (ctx->pending_redirect) {
3720 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3721 * only if run as "bash", not "sh" */
3722 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3724 * ...the word that follows the redirection operator
3725 * shall be subjected to tilde expansion, parameter expansion,
3726 * command substitution, arithmetic expansion, and quote
3727 * removal. Pathname expansion shall not be performed
3728 * on the word by a non-interactive shell; an interactive
3729 * shell may perform it, but shall do so only when
3730 * the expansion would result in one word."
3732 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3733 /* Cater for >\file case:
3734 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3735 * Same with heredocs:
3736 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3738 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3739 unbackslash(ctx->pending_redirect->rd_filename);
3740 /* Is it <<"HEREDOC"? */
3741 if (word->has_quoted_part) {
3742 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3745 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3746 ctx->pending_redirect = NULL;
3749 # if ENABLE_HUSH_CASE
3750 if (ctx->ctx_dsemicolon
3751 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3753 /* already done when ctx_dsemicolon was set to 1: */
3754 /* ctx->ctx_res_w = RES_MATCH; */
3755 ctx->ctx_dsemicolon = 0;
3758 if (!command->argv /* if it's the first word... */
3759 # if ENABLE_HUSH_LOOPS
3760 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3761 && ctx->ctx_res_w != RES_IN
3763 # if ENABLE_HUSH_CASE
3764 && ctx->ctx_res_w != RES_CASE
3767 int reserved = reserved_word(word, ctx);
3768 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3770 o_reset_to_empty_unquoted(word);
3771 debug_printf_parse("done_word return %d\n",
3772 (ctx->ctx_res_w == RES_SNTX));
3773 return (ctx->ctx_res_w == RES_SNTX);
3776 if (strcmp(word->data, "[[") == 0) {
3777 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3783 if (command->group) {
3784 /* "{ echo foo; } echo bar" - bad */
3785 syntax_error_at(word->data);
3786 debug_printf_parse("done_word return 1: syntax error, "
3787 "groups and arglists don't mix\n");
3791 /* If this word wasn't an assignment, next ones definitely
3792 * can't be assignments. Even if they look like ones. */
3793 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3794 && word->o_assignment != WORD_IS_KEYWORD
3796 word->o_assignment = NOT_ASSIGNMENT;
3798 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3799 command->assignment_cnt++;
3800 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3802 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3803 word->o_assignment = MAYBE_ASSIGNMENT;
3805 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3807 if (word->has_quoted_part
3808 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3809 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3810 /* (otherwise it's known to be not empty and is already safe) */
3812 /* exclude "$@" - it can expand to no word despite "" */
3813 char *p = word->data;
3814 while (p[0] == SPECIAL_VAR_SYMBOL
3815 && (p[1] & 0x7f) == '@'
3816 && p[2] == SPECIAL_VAR_SYMBOL
3821 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3822 debug_print_strings("word appended to argv", command->argv);
3825 #if ENABLE_HUSH_LOOPS
3826 if (ctx->ctx_res_w == RES_FOR) {
3827 if (word->has_quoted_part
3828 || !is_well_formed_var_name(command->argv[0], '\0')
3830 /* bash says just "not a valid identifier" */
3831 syntax_error("not a valid identifier in for");
3834 /* Force FOR to have just one word (variable name) */
3835 /* NB: basically, this makes hush see "for v in ..."
3836 * syntax as if it is "for v; in ...". FOR and IN become
3837 * two pipe structs in parse tree. */
3838 done_pipe(ctx, PIPE_SEQ);
3841 #if ENABLE_HUSH_CASE
3842 /* Force CASE to have just one word */
3843 if (ctx->ctx_res_w == RES_CASE) {
3844 done_pipe(ctx, PIPE_SEQ);
3848 o_reset_to_empty_unquoted(word);
3850 debug_printf_parse("done_word return 0\n");
3855 /* Peek ahead in the input to find out if we have a "&n" construct,
3856 * as in "2>&1", that represents duplicating a file descriptor.
3858 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3859 * REDIRFD_SYNTAX_ERR if syntax error,
3860 * REDIRFD_TO_FILE if no & was seen,
3861 * or the number found.
3864 #define parse_redir_right_fd(as_string, input) \
3865 parse_redir_right_fd(input)
3867 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3873 return REDIRFD_TO_FILE;
3875 ch = i_getch(input); /* get the & */
3876 nommu_addchr(as_string, ch);
3879 ch = i_getch(input);
3880 nommu_addchr(as_string, ch);
3881 return REDIRFD_CLOSE;
3885 while (ch != EOF && isdigit(ch)) {
3886 d = d*10 + (ch-'0');
3888 ch = i_getch(input);
3889 nommu_addchr(as_string, ch);
3894 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3896 bb_error_msg("ambiguous redirect");
3897 return REDIRFD_SYNTAX_ERR;
3900 /* Return code is 0 normal, 1 if a syntax error is detected
3902 static int parse_redirect(struct parse_context *ctx,
3905 struct in_str *input)
3907 struct command *command = ctx->command;
3908 struct redir_struct *redir;
3909 struct redir_struct **redirp;
3912 dup_num = REDIRFD_TO_FILE;
3913 if (style != REDIRECT_HEREDOC) {
3914 /* Check for a '>&1' type redirect */
3915 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3916 if (dup_num == REDIRFD_SYNTAX_ERR)
3919 int ch = i_peek(input);
3920 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3921 if (dup_num) { /* <<-... */
3922 ch = i_getch(input);
3923 nommu_addchr(&ctx->as_string, ch);
3928 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3929 int ch = i_peek(input);
3931 /* >|FILE redirect ("clobbering" >).
3932 * Since we do not support "set -o noclobber" yet,
3933 * >| and > are the same for now. Just eat |.
3935 ch = i_getch(input);
3936 nommu_addchr(&ctx->as_string, ch);
3940 /* Create a new redir_struct and append it to the linked list */
3941 redirp = &command->redirects;
3942 while ((redir = *redirp) != NULL) {
3943 redirp = &(redir->next);
3945 *redirp = redir = xzalloc(sizeof(*redir));
3946 /* redir->next = NULL; */
3947 /* redir->rd_filename = NULL; */
3948 redir->rd_type = style;
3949 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3951 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3952 redir_table[style].descrip);
3954 redir->rd_dup = dup_num;
3955 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3956 /* Erik had a check here that the file descriptor in question
3957 * is legit; I postpone that to "run time"
3958 * A "-" representation of "close me" shows up as a -3 here */
3959 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3960 redir->rd_fd, redir->rd_dup);
3962 #if 0 /* Instead we emit error message at run time */
3963 if (ctx->pending_redirect) {
3964 /* For example, "cmd > <file" */
3965 syntax_error("invalid redirect");
3968 /* Set ctx->pending_redirect, so we know what to do at the
3969 * end of the next parsed word. */
3970 ctx->pending_redirect = redir;
3975 /* If a redirect is immediately preceded by a number, that number is
3976 * supposed to tell which file descriptor to redirect. This routine
3977 * looks for such preceding numbers. In an ideal world this routine
3978 * needs to handle all the following classes of redirects...
3979 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3980 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3981 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3982 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3984 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3986 * ... If n is quoted, the number shall not be recognized as part of
3987 * the redirection expression. For example:
3989 * writes the character 2 into file a"
3990 * We are getting it right by setting ->has_quoted_part on any \<char>
3992 * A -1 return means no valid number was found,
3993 * the caller should use the appropriate default for this redirection.
3995 static int redirect_opt_num(o_string *o)
3999 if (o->data == NULL)
4001 num = bb_strtou(o->data, NULL, 10);
4002 if (errno || num < 0)
4004 o_reset_to_empty_unquoted(o);
4009 #define fetch_till_str(as_string, input, word, skip_tabs) \
4010 fetch_till_str(input, word, skip_tabs)
4012 static char *fetch_till_str(o_string *as_string,
4013 struct in_str *input,
4017 o_string heredoc = NULL_O_STRING;
4019 int prev = 0; /* not \ */
4025 ch = i_getch(input);
4027 nommu_addchr(as_string, ch);
4028 if (ch == '\n' || ch == EOF) {
4030 if ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\') {
4031 if (strcmp(heredoc.data + past_EOL, word) == 0) {
4032 heredoc.data[past_EOL] = '\0';
4033 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
4034 return heredoc.data;
4037 /* This is a new line.
4038 * Remember position and backslash-escaping status.
4040 o_addchr(&heredoc, ch);
4043 past_EOL = heredoc.length;
4044 /* Get 1st char of next line, possibly skipping leading tabs */
4046 ch = i_getch(input);
4048 nommu_addchr(as_string, ch);
4049 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
4050 /* If this immediately ended the line,
4051 * go back to end-of-line checks.
4054 goto check_heredoc_end;
4059 o_free_unsafe(&heredoc);
4062 o_addchr(&heredoc, ch);
4063 nommu_addchr(as_string, ch);
4064 if (prev == '\\' && ch == '\\')
4065 /* Correctly handle foo\\<eol> (not a line cont.) */
4066 prev = 0; /* not \ */
4072 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
4073 * and load them all. There should be exactly heredoc_cnt of them.
4075 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
4077 struct pipe *pi = ctx->list_head;
4079 while (pi && heredoc_cnt) {
4081 struct command *cmd = pi->cmds;
4083 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
4085 cmd->argv ? cmd->argv[0] : "NONE");
4086 for (i = 0; i < pi->num_cmds; i++) {
4087 struct redir_struct *redir = cmd->redirects;
4089 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
4090 i, cmd->argv ? cmd->argv[0] : "NONE");
4092 if (redir->rd_type == REDIRECT_HEREDOC) {
4095 redir->rd_type = REDIRECT_HEREDOC2;
4096 /* redir->rd_dup is (ab)used to indicate <<- */
4097 p = fetch_till_str(&ctx->as_string, input,
4098 redir->rd_filename, redir->rd_dup);
4100 syntax_error("unexpected EOF in here document");
4103 free(redir->rd_filename);
4104 redir->rd_filename = p;
4107 redir = redir->next;
4114 /* Should be 0. If it isn't, it's a parse error */
4116 bb_error_msg_and_die("heredoc BUG 2");
4122 static int run_list(struct pipe *pi);
4124 #define parse_stream(pstring, input, end_trigger) \
4125 parse_stream(input, end_trigger)
4127 static struct pipe *parse_stream(char **pstring,
4128 struct in_str *input,
4132 #if !ENABLE_HUSH_FUNCTIONS
4133 #define parse_group(dest, ctx, input, ch) \
4134 parse_group(ctx, input, ch)
4136 static int parse_group(o_string *dest, struct parse_context *ctx,
4137 struct in_str *input, int ch)
4139 /* dest contains characters seen prior to ( or {.
4140 * Typically it's empty, but for function defs,
4141 * it contains function name (without '()'). */
4142 struct pipe *pipe_list;
4144 struct command *command = ctx->command;
4146 debug_printf_parse("parse_group entered\n");
4147 #if ENABLE_HUSH_FUNCTIONS
4148 if (ch == '(' && !dest->has_quoted_part) {
4150 if (done_word(dest, ctx))
4153 goto skip; /* (... */
4154 if (command->argv[1]) { /* word word ... (... */
4155 syntax_error_unexpected_ch('(');
4158 /* it is "word(..." or "word (..." */
4160 ch = i_getch(input);
4161 while (ch == ' ' || ch == '\t');
4163 syntax_error_unexpected_ch(ch);
4166 nommu_addchr(&ctx->as_string, ch);
4168 ch = i_getch(input);
4169 while (ch == ' ' || ch == '\t' || ch == '\n');
4171 syntax_error_unexpected_ch(ch);
4174 nommu_addchr(&ctx->as_string, ch);
4175 command->cmd_type = CMD_FUNCDEF;
4180 #if 0 /* Prevented by caller */
4181 if (command->argv /* word [word]{... */
4182 || dest->length /* word{... */
4183 || dest->has_quoted_part /* ""{... */
4186 debug_printf_parse("parse_group return 1: "
4187 "syntax error, groups and arglists don't mix\n");
4192 #if ENABLE_HUSH_FUNCTIONS
4198 command->cmd_type = CMD_SUBSHELL;
4200 /* bash does not allow "{echo...", requires whitespace */
4202 if (ch != ' ' && ch != '\t' && ch != '\n'
4203 && ch != '(' /* but "{(..." is allowed (without whitespace) */
4205 syntax_error_unexpected_ch(ch);
4209 ch = i_getch(input);
4210 nommu_addchr(&ctx->as_string, ch);
4216 # define as_string NULL
4218 char *as_string = NULL;
4220 pipe_list = parse_stream(&as_string, input, endch);
4223 o_addstr(&ctx->as_string, as_string);
4225 /* empty ()/{} or parse error? */
4226 if (!pipe_list || pipe_list == ERR_PTR) {
4227 /* parse_stream already emitted error msg */
4230 debug_printf_parse("parse_group return 1: "
4231 "parse_stream returned %p\n", pipe_list);
4234 command->group = pipe_list;
4236 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
4237 command->group_as_string = as_string;
4238 debug_printf_parse("end of group, remembering as:'%s'\n",
4239 command->group_as_string);
4243 debug_printf_parse("parse_group return 0\n");
4245 /* command remains "open", available for possible redirects */
4248 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
4253 ch = i_getch(input);
4256 ch2 = i_peek(input);
4259 /* backslash+newline, skip it */
4264 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
4272 ch2 = i_peek2(input);
4275 /* backslash+newline, skip it */
4281 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4282 /* Subroutines for copying $(...) and `...` things */
4283 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4285 static int add_till_single_quote(o_string *dest, struct in_str *input)
4288 int ch = i_getch(input);
4290 syntax_error_unterm_ch('\'');
4298 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4299 static int add_till_double_quote(o_string *dest, struct in_str *input)
4302 int ch = i_getch(input);
4304 syntax_error_unterm_ch('"');
4309 if (ch == '\\') { /* \x. Copy both chars. */
4311 ch = i_getch(input);
4315 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4320 //if (ch == '$') ...
4323 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4325 * "Within the backquoted style of command substitution, backslash
4326 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4327 * The search for the matching backquote shall be satisfied by the first
4328 * backquote found without a preceding backslash; during this search,
4329 * if a non-escaped backquote is encountered within a shell comment,
4330 * a here-document, an embedded command substitution of the $(command)
4331 * form, or a quoted string, undefined results occur. A single-quoted
4332 * or double-quoted string that begins, but does not end, within the
4333 * "`...`" sequence produces undefined results."
4335 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4337 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4340 int ch = i_getch(input);
4344 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4345 ch = i_getch(input);
4349 && (!in_dquote || ch != '"')
4351 o_addchr(dest, '\\');
4355 syntax_error_unterm_ch('`');
4361 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4362 * quoting and nested ()s.
4363 * "With the $(command) style of command substitution, all characters
4364 * following the open parenthesis to the matching closing parenthesis
4365 * constitute the command. Any valid shell script can be used for command,
4366 * except a script consisting solely of redirections which produces
4367 * unspecified results."
4369 * echo $(echo '(TEST)' BEST) (TEST) BEST
4370 * echo $(echo 'TEST)' BEST) TEST) BEST
4371 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4373 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4374 * can contain arbitrary constructs, just like $(cmd).
4375 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4376 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4378 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4379 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4382 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4383 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4384 char end_char2 = end_ch >> 8;
4386 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4389 ch = i_getch(input);
4391 syntax_error_unterm_ch(end_ch);
4395 # if BASH_SUBSTR || BASH_PATTERN_SUBST
4401 /* we look for closing )) of $((EXPR)) */
4402 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4403 i_getch(input); /* eat second ')' */
4408 if (ch == '(' || ch == '{') {
4409 ch = (ch == '(' ? ')' : '}');
4410 if (!add_till_closing_bracket(dest, input, ch))
4416 if (!add_till_single_quote(dest, input))
4422 if (!add_till_double_quote(dest, input))
4428 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4434 /* \x. Copy verbatim. Important for \(, \) */
4435 ch = i_getch(input);
4437 syntax_error_unterm_ch(')');
4442 /* "backslash+newline", ignore both */
4443 o_delchr(dest); /* undo insertion of '\' */
4453 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4455 /* Return code: 0 for OK, 1 for syntax error */
4457 #define parse_dollar(as_string, dest, input, quote_mask) \
4458 parse_dollar(dest, input, quote_mask)
4459 #define as_string NULL
4461 static int parse_dollar(o_string *as_string,
4463 struct in_str *input, unsigned char quote_mask)
4465 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4467 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4469 ch = i_getch(input);
4470 nommu_addchr(as_string, ch);
4472 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4474 debug_printf_parse(": '%c'\n", ch);
4475 o_addchr(dest, ch | quote_mask);
4477 ch = i_peek_and_eat_bkslash_nl(input);
4478 if (!isalnum(ch) && ch != '_') {
4479 /* End of variable name reached */
4482 ch = i_getch(input);
4483 nommu_addchr(as_string, ch);
4485 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4486 } else if (isdigit(ch)) {
4488 ch = i_getch(input);
4489 nommu_addchr(as_string, ch);
4490 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4491 debug_printf_parse(": '%c'\n", ch);
4492 o_addchr(dest, ch | quote_mask);
4493 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4494 } else switch (ch) {
4496 case '!': /* last bg pid */
4497 case '?': /* last exit code */
4498 case '#': /* number of args */
4499 case '*': /* args */
4500 case '@': /* args */
4501 goto make_one_char_var;
4505 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4507 ch = i_getch(input); /* eat '{' */
4508 nommu_addchr(as_string, ch);
4510 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4511 /* It should be ${?}, or ${#var},
4512 * or even ${?+subst} - operator acting on a special variable,
4513 * or the beginning of variable name.
4516 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4519 syntax_error_unterm_str("${name}");
4520 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4523 nommu_addchr(as_string, ch);
4527 /* It's possible to just call add_till_closing_bracket() at this point.
4528 * However, this regresses some of our testsuite cases
4529 * which check invalid constructs like ${%}.
4530 * Oh well... let's check that the var name part is fine... */
4536 debug_printf_parse(": '%c'\n", ch);
4538 ch = i_getch(input);
4539 nommu_addchr(as_string, ch);
4543 if (!isalnum(ch) && ch != '_') {
4545 unsigned char last_ch;
4546 /* handle parameter expansions
4547 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4549 if (!strchr(VAR_SUBST_OPS, ch)) { /* ${var<bad_char>... */
4550 if (len_single_ch != '#'
4551 /*|| !strchr(SPECIAL_VARS_STR, ch) - disallow errors like ${#+} ? */
4552 || i_peek(input) != '}'
4554 goto bad_dollar_syntax;
4556 /* else: it's "length of C" ${#C} op,
4557 * where C is a single char
4558 * special var name, e.g. ${#!}.
4561 /* Eat everything until closing '}' (or ':') */
4565 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4567 /* It's ${var:N[:M]} thing */
4568 end_ch = '}' * 0x100 + ':';
4570 if (BASH_PATTERN_SUBST
4573 /* It's ${var/[/]pattern[/repl]} thing */
4574 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4576 nommu_addchr(as_string, '/');
4579 end_ch = '}' * 0x100 + '/';
4585 #if ENABLE_HUSH_DOLLAR_OPS
4586 last_ch = add_till_closing_bracket(dest, input, end_ch);
4587 if (last_ch == 0) /* error? */
4590 #error Simple code to only allow ${var} is not implemented
4593 o_addstr(as_string, dest->data + pos);
4594 o_addchr(as_string, last_ch);
4597 if ((BASH_SUBSTR || BASH_PATTERN_SUBST)
4598 && (end_ch & 0xff00)
4600 /* close the first block: */
4601 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4602 /* while parsing N from ${var:N[:M]}
4603 * or pattern from ${var/[/]pattern[/repl]} */
4604 if ((end_ch & 0xff) == last_ch) {
4605 /* got ':' or '/'- parse the rest */
4610 if (BASH_SUBSTR && end_ch == '}' * 0x100 + ':') {
4611 /* it's ${var:N} - emulate :999999999 */
4612 o_addstr(dest, "999999999");
4613 } /* else: it's ${var/[/]pattern} */
4617 len_single_ch = 0; /* it can't be ${#C} op */
4619 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4622 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4626 ch = i_getch(input);
4627 nommu_addchr(as_string, ch);
4628 # if ENABLE_FEATURE_SH_MATH
4629 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4630 ch = i_getch(input);
4631 nommu_addchr(as_string, ch);
4632 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4633 o_addchr(dest, /*quote_mask |*/ '+');
4636 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4637 return 0; /* error */
4639 o_addstr(as_string, dest->data + pos);
4640 o_addchr(as_string, ')');
4641 o_addchr(as_string, ')');
4643 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4647 # if ENABLE_HUSH_TICK
4648 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4649 o_addchr(dest, quote_mask | '`');
4652 if (!add_till_closing_bracket(dest, input, ')'))
4653 return 0; /* error */
4655 o_addstr(as_string, dest->data + pos);
4656 o_addchr(as_string, ')');
4658 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4664 ch = i_getch(input);
4665 nommu_addchr(as_string, ch);
4666 ch = i_peek_and_eat_bkslash_nl(input);
4667 if (isalnum(ch)) { /* it's $_name or $_123 */
4672 /* TODO: $_ and $-: */
4673 /* $_ Shell or shell script name; or last argument of last command
4674 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4675 * but in command's env, set to full pathname used to invoke it */
4676 /* $- Option flags set by set builtin or shell options (-i etc) */
4678 o_addQchr(dest, '$');
4680 debug_printf_parse("parse_dollar return 1 (ok)\n");
4686 # if BASH_PATTERN_SUBST
4687 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4688 encode_string(dest, input, dquote_end, process_bkslash)
4690 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4691 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4692 encode_string(dest, input, dquote_end)
4694 #define as_string NULL
4698 # if BASH_PATTERN_SUBST
4699 /* all parameters are needed, no macro tricks */
4701 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4702 encode_string(as_string, dest, input, dquote_end)
4705 static int encode_string(o_string *as_string,
4707 struct in_str *input,
4709 int process_bkslash)
4711 #if !BASH_PATTERN_SUBST
4712 const int process_bkslash = 1;
4718 ch = i_getch(input);
4720 nommu_addchr(as_string, ch);
4721 if (ch == dquote_end) { /* may be only '"' or EOF */
4722 debug_printf_parse("encode_string return 1 (ok)\n");
4725 /* note: can't move it above ch == dquote_end check! */
4727 syntax_error_unterm_ch('"');
4728 return 0; /* error */
4732 next = i_peek(input);
4734 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4735 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4736 if (process_bkslash && ch == '\\') {
4738 syntax_error("\\<eof>");
4742 * "The backslash retains its special meaning [in "..."]
4743 * only when followed by one of the following characters:
4744 * $, `, ", \, or <newline>. A double quote may be quoted
4745 * within double quotes by preceding it with a backslash."
4746 * NB: in (unquoted) heredoc, above does not apply to ",
4747 * therefore we check for it by "next == dquote_end" cond.
4749 if (next == dquote_end || strchr("$`\\\n", next)) {
4750 ch = i_getch(input); /* eat next */
4752 goto again; /* skip \<newline> */
4753 } /* else: ch remains == '\\', and we double it below: */
4754 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4755 nommu_addchr(as_string, ch);
4759 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4760 debug_printf_parse("encode_string return 0: "
4761 "parse_dollar returned 0 (error)\n");
4766 #if ENABLE_HUSH_TICK
4768 //unsigned pos = dest->length;
4769 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4770 o_addchr(dest, 0x80 | '`');
4771 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4772 return 0; /* error */
4773 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4774 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4778 o_addQchr(dest, ch);
4784 * Scan input until EOF or end_trigger char.
4785 * Return a list of pipes to execute, or NULL on EOF
4786 * or if end_trigger character is met.
4787 * On syntax error, exit if shell is not interactive,
4788 * reset parsing machinery and start parsing anew,
4789 * or return ERR_PTR.
4791 static struct pipe *parse_stream(char **pstring,
4792 struct in_str *input,
4795 struct parse_context ctx;
4796 o_string dest = NULL_O_STRING;
4799 /* Single-quote triggers a bypass of the main loop until its mate is
4800 * found. When recursing, quote state is passed in via dest->o_expflags.
4802 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4803 end_trigger ? end_trigger : 'X');
4806 /* If very first arg is "" or '', dest.data may end up NULL.
4807 * Preventing this: */
4808 o_addchr(&dest, '\0');
4811 /* We used to separate words on $IFS here. This was wrong.
4812 * $IFS is used only for word splitting when $var is expanded,
4813 * here we should use blank chars as separators, not $IFS
4816 if (MAYBE_ASSIGNMENT != 0)
4817 dest.o_assignment = MAYBE_ASSIGNMENT;
4818 initialize_context(&ctx);
4821 const char *is_blank;
4822 const char *is_special;
4826 redir_type redir_style;
4828 ch = i_getch(input);
4829 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4830 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4835 syntax_error_unterm_str("here document");
4838 if (end_trigger == ')') {
4839 syntax_error_unterm_ch('(');
4842 if (end_trigger == '}') {
4843 syntax_error_unterm_ch('{');
4847 if (done_word(&dest, &ctx)) {
4851 done_pipe(&ctx, PIPE_SEQ);
4853 /* If we got nothing... */
4854 /* (this makes bare "&" cmd a no-op.
4855 * bash says: "syntax error near unexpected token '&'") */
4856 if (pi->num_cmds == 0
4857 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4863 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4865 *pstring = ctx.as_string.data;
4867 o_free_unsafe(&ctx.as_string);
4870 debug_printf_parse("parse_stream return %p\n", pi);
4873 nommu_addchr(&ctx.as_string, ch);
4877 next = i_peek(input);
4879 is_special = "{}<>;&|()#'" /* special outside of "str" */
4880 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4881 /* Are { and } special here? */
4882 if (ctx.command->argv /* word [word]{... - non-special */
4883 || dest.length /* word{... - non-special */
4884 || dest.has_quoted_part /* ""{... - non-special */
4885 || (next != ';' /* }; - special */
4886 && next != ')' /* }) - special */
4887 && next != '(' /* {( - special */
4888 && next != '&' /* }& and }&& ... - special */
4889 && next != '|' /* }|| ... - special */
4890 && !strchr(defifs, next) /* {word - non-special */
4893 /* They are not special, skip "{}" */
4896 is_special = strchr(is_special, ch);
4897 is_blank = strchr(defifs, ch);
4899 if (!is_special && !is_blank) { /* ordinary char */
4901 o_addQchr(&dest, ch);
4902 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4903 || dest.o_assignment == WORD_IS_KEYWORD)
4905 && is_well_formed_var_name(dest.data, '=')
4907 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4908 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4914 if (done_word(&dest, &ctx)) {
4918 /* Is this a case when newline is simply ignored?
4920 * "cmd | <newline> cmd ..."
4921 * "case ... in <newline> word) ..."
4923 if (IS_NULL_CMD(ctx.command)
4924 && dest.length == 0 && !dest.has_quoted_part
4926 /* This newline can be ignored. But...
4927 * Without check #1, interactive shell
4928 * ignores even bare <newline>,
4929 * and shows the continuation prompt:
4930 * ps1_prompt$ <enter>
4931 * ps2> _ <=== wrong, should be ps1
4932 * Without check #2, "cmd & <newline>"
4933 * is similarly mistreated.
4934 * (BTW, this makes "cmd & cmd"
4935 * and "cmd && cmd" non-orthogonal.
4936 * Really, ask yourself, why
4937 * "cmd && <newline>" doesn't start
4938 * cmd but waits for more input?
4939 * The only reason is that it might be
4940 * a "cmd1 && <nl> cmd2 &" construct,
4941 * cmd1 may need to run in BG).
4943 struct pipe *pi = ctx.list_head;
4944 if (pi->num_cmds != 0 /* check #1 */
4945 && pi->followup != PIPE_BG /* check #2 */
4950 /* Treat newline as a command separator. */
4951 done_pipe(&ctx, PIPE_SEQ);
4952 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4954 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4959 dest.o_assignment = MAYBE_ASSIGNMENT;
4960 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4962 /* note: if (is_blank) continue;
4963 * will still trigger for us */
4967 /* "cmd}" or "cmd }..." without semicolon or &:
4968 * } is an ordinary char in this case, even inside { cmd; }
4969 * Pathological example: { ""}; } should exec "}" cmd
4972 if (dest.length != 0 /* word} */
4973 || dest.has_quoted_part /* ""} */
4977 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4978 /* Generally, there should be semicolon: "cmd; }"
4979 * However, bash allows to omit it if "cmd" is
4980 * a group. Examples:
4983 * { echo 0 >&2 | { echo 1; } }
4984 * { while false; do :; done }
4985 * { case a in b) ;; esac }
4987 if (ctx.command->group)
4991 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4992 /* Can't be an end of {cmd}, skip the check */
4993 goto skip_end_trigger;
4994 /* else: } does terminate a group */
4997 if (end_trigger && end_trigger == ch
4998 && (ch != ';' || heredoc_cnt == 0)
4999 #if ENABLE_HUSH_CASE
5001 || ctx.ctx_res_w != RES_MATCH
5002 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
5007 /* This is technically valid:
5008 * { cat <<HERE; }; echo Ok
5012 * but we don't support this.
5013 * We require heredoc to be in enclosing {}/(),
5016 syntax_error_unterm_str("here document");
5019 if (done_word(&dest, &ctx)) {
5022 done_pipe(&ctx, PIPE_SEQ);
5023 dest.o_assignment = MAYBE_ASSIGNMENT;
5024 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5025 /* Do we sit outside of any if's, loops or case's? */
5027 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
5031 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
5033 *pstring = ctx.as_string.data;
5035 o_free_unsafe(&ctx.as_string);
5037 if (ch != ';' && IS_NULL_PIPE(ctx.list_head)) {
5038 /* Example: bare "{ }", "()" */
5039 G.last_exitcode = 2; /* bash compat */
5040 syntax_error_unexpected_ch(ch);
5043 debug_printf_parse("parse_stream return %p: "
5044 "end_trigger char found\n",
5047 return ctx.list_head;
5054 /* Catch <, > before deciding whether this word is
5055 * an assignment. a=1 2>z b=2: b=2 is still assignment */
5058 redir_fd = redirect_opt_num(&dest);
5059 if (done_word(&dest, &ctx)) {
5062 redir_style = REDIRECT_OVERWRITE;
5064 redir_style = REDIRECT_APPEND;
5065 ch = i_getch(input);
5066 nommu_addchr(&ctx.as_string, ch);
5069 else if (next == '(') {
5070 syntax_error(">(process) not supported");
5074 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5076 continue; /* back to top of while (1) */
5078 redir_fd = redirect_opt_num(&dest);
5079 if (done_word(&dest, &ctx)) {
5082 redir_style = REDIRECT_INPUT;
5084 redir_style = REDIRECT_HEREDOC;
5086 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
5087 ch = i_getch(input);
5088 nommu_addchr(&ctx.as_string, ch);
5089 } else if (next == '>') {
5090 redir_style = REDIRECT_IO;
5091 ch = i_getch(input);
5092 nommu_addchr(&ctx.as_string, ch);
5095 else if (next == '(') {
5096 syntax_error("<(process) not supported");
5100 if (parse_redirect(&ctx, redir_fd, redir_style, input))
5102 continue; /* back to top of while (1) */
5104 if (dest.length == 0 && !dest.has_quoted_part) {
5105 /* skip "#comment" */
5108 if (ch == EOF || ch == '\n')
5111 /* note: we do not add it to &ctx.as_string */
5113 nommu_addchr(&ctx.as_string, '\n');
5114 continue; /* back to top of while (1) */
5119 /* It's "\<newline>" */
5121 /* Remove trailing '\' from ctx.as_string */
5122 ctx.as_string.data[--ctx.as_string.length] = '\0';
5124 ch = i_getch(input); /* eat it */
5125 continue; /* back to top of while (1) */
5130 if (dest.o_assignment == MAYBE_ASSIGNMENT
5131 /* check that we are not in word in "a=1 2>word b=1": */
5132 && !ctx.pending_redirect
5134 /* ch is a special char and thus this word
5135 * cannot be an assignment */
5136 dest.o_assignment = NOT_ASSIGNMENT;
5137 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5140 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
5143 case '#': /* non-comment #: "echo a#b" etc */
5144 o_addQchr(&dest, ch);
5148 syntax_error("\\<eof>");
5151 ch = i_getch(input);
5152 /* note: ch != '\n' (that case does not reach this place) */
5153 o_addchr(&dest, '\\');
5154 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
5155 o_addchr(&dest, ch);
5156 nommu_addchr(&ctx.as_string, ch);
5157 /* Example: echo Hello \2>file
5158 * we need to know that word 2 is quoted */
5159 dest.has_quoted_part = 1;
5162 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
5163 debug_printf_parse("parse_stream parse error: "
5164 "parse_dollar returned 0 (error)\n");
5169 dest.has_quoted_part = 1;
5170 if (next == '\'' && !ctx.pending_redirect) {
5171 insert_empty_quoted_str_marker:
5172 nommu_addchr(&ctx.as_string, next);
5173 i_getch(input); /* eat second ' */
5174 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5175 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5178 ch = i_getch(input);
5180 syntax_error_unterm_ch('\'');
5183 nommu_addchr(&ctx.as_string, ch);
5186 o_addqchr(&dest, ch);
5191 dest.has_quoted_part = 1;
5192 if (next == '"' && !ctx.pending_redirect)
5193 goto insert_empty_quoted_str_marker;
5194 if (dest.o_assignment == NOT_ASSIGNMENT)
5195 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
5196 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
5198 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
5200 #if ENABLE_HUSH_TICK
5202 USE_FOR_NOMMU(unsigned pos;)
5204 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5205 o_addchr(&dest, '`');
5206 USE_FOR_NOMMU(pos = dest.length;)
5207 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
5210 o_addstr(&ctx.as_string, dest.data + pos);
5211 o_addchr(&ctx.as_string, '`');
5213 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
5214 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
5219 #if ENABLE_HUSH_CASE
5222 if (done_word(&dest, &ctx)) {
5225 done_pipe(&ctx, PIPE_SEQ);
5226 #if ENABLE_HUSH_CASE
5227 /* Eat multiple semicolons, detect
5228 * whether it means something special */
5233 ch = i_getch(input);
5234 nommu_addchr(&ctx.as_string, ch);
5235 if (ctx.ctx_res_w == RES_CASE_BODY) {
5236 ctx.ctx_dsemicolon = 1;
5237 ctx.ctx_res_w = RES_MATCH;
5243 /* We just finished a cmd. New one may start
5244 * with an assignment */
5245 dest.o_assignment = MAYBE_ASSIGNMENT;
5246 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
5249 if (done_word(&dest, &ctx)) {
5253 ch = i_getch(input);
5254 nommu_addchr(&ctx.as_string, ch);
5255 done_pipe(&ctx, PIPE_AND);
5257 done_pipe(&ctx, PIPE_BG);
5261 if (done_word(&dest, &ctx)) {
5264 #if ENABLE_HUSH_CASE
5265 if (ctx.ctx_res_w == RES_MATCH)
5266 break; /* we are in case's "word | word)" */
5268 if (next == '|') { /* || */
5269 ch = i_getch(input);
5270 nommu_addchr(&ctx.as_string, ch);
5271 done_pipe(&ctx, PIPE_OR);
5273 /* we could pick up a file descriptor choice here
5274 * with redirect_opt_num(), but bash doesn't do it.
5275 * "echo foo 2| cat" yields "foo 2". */
5280 #if ENABLE_HUSH_CASE
5281 /* "case... in [(]word)..." - skip '(' */
5282 if (ctx.ctx_res_w == RES_MATCH
5283 && ctx.command->argv == NULL /* not (word|(... */
5284 && dest.length == 0 /* not word(... */
5285 && dest.has_quoted_part == 0 /* not ""(... */
5291 if (parse_group(&dest, &ctx, input, ch) != 0) {
5296 #if ENABLE_HUSH_CASE
5297 if (ctx.ctx_res_w == RES_MATCH)
5301 /* proper use of this character is caught by end_trigger:
5302 * if we see {, we call parse_group(..., end_trigger='}')
5303 * and it will match } earlier (not here). */
5304 G.last_exitcode = 2;
5305 syntax_error_unexpected_ch(ch);
5309 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5314 G.last_exitcode = 1;
5317 struct parse_context *pctx;
5318 IF_HAS_KEYWORDS(struct parse_context *p2;)
5320 /* Clean up allocated tree.
5321 * Sample for finding leaks on syntax error recovery path.
5322 * Run it from interactive shell, watch pmap `pidof hush`.
5323 * while if false; then false; fi; do break; fi
5324 * Samples to catch leaks at execution:
5325 * while if (true | { true;}); then echo ok; fi; do break; done
5326 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5330 /* Update pipe/command counts,
5331 * otherwise freeing may miss some */
5332 done_pipe(pctx, PIPE_SEQ);
5333 debug_printf_clean("freeing list %p from ctx %p\n",
5334 pctx->list_head, pctx);
5335 debug_print_tree(pctx->list_head, 0);
5336 free_pipe_list(pctx->list_head);
5337 debug_printf_clean("freed list %p\n", pctx->list_head);
5339 o_free_unsafe(&pctx->as_string);
5341 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5345 IF_HAS_KEYWORDS(pctx = p2;)
5346 } while (HAS_KEYWORDS && pctx);
5359 /*** Execution routines ***/
5361 /* Expansion can recurse, need forward decls: */
5362 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
5363 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5364 #define expand_string_to_string(str, do_unbackslash) \
5365 expand_string_to_string(str)
5367 static char *expand_string_to_string(const char *str, int do_unbackslash);
5368 #if ENABLE_HUSH_TICK
5369 static int process_command_subs(o_string *dest, const char *s);
5372 /* expand_strvec_to_strvec() takes a list of strings, expands
5373 * all variable references within and returns a pointer to
5374 * a list of expanded strings, possibly with larger number
5375 * of strings. (Think VAR="a b"; echo $VAR).
5376 * This new list is allocated as a single malloc block.
5377 * NULL-terminated list of char* pointers is at the beginning of it,
5378 * followed by strings themselves.
5379 * Caller can deallocate entire list by single free(list). */
5381 /* A horde of its helpers come first: */
5383 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5385 while (--len >= 0) {
5388 #if ENABLE_HUSH_BRACE_EXPANSION
5389 if (c == '{' || c == '}') {
5390 /* { -> \{, } -> \} */
5392 /* And now we want to add { or } and continue:
5395 * luckily, just falling through achieves this.
5401 /* \z -> \\\z; \<eol> -> \\<eol> */
5406 o_addchr(o, *str++);
5412 /* Store given string, finalizing the word and starting new one whenever
5413 * we encounter IFS char(s). This is used for expanding variable values.
5414 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5415 * Return in *ended_with_ifs:
5416 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5418 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5420 int last_is_ifs = 0;
5425 if (!*str) /* EOL - do not finalize word */
5427 word_len = strcspn(str, G.ifs);
5429 /* We have WORD_LEN leading non-IFS chars */
5430 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5431 o_addblock(output, str, word_len);
5433 /* Protect backslashes against globbing up :)
5434 * Example: "v='\*'; echo b$v" prints "b\*"
5435 * (and does not try to glob on "*")
5437 o_addblock_duplicate_backslash(output, str, word_len);
5438 /*/ Why can't we do it easier? */
5439 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5440 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5444 if (!*str) /* EOL - do not finalize word */
5448 /* We know str here points to at least one IFS char */
5450 str += strspn(str, G.ifs); /* skip IFS chars */
5451 if (!*str) /* EOL - do not finalize word */
5454 /* Start new word... but not always! */
5455 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5456 if (output->has_quoted_part
5457 /* Case "v=' a'; echo $v":
5458 * here nothing precedes the space in $v expansion,
5459 * therefore we should not finish the word
5460 * (IOW: if there *is* word to finalize, only then do it):
5462 || (n > 0 && output->data[output->length - 1])
5464 o_addchr(output, '\0');
5465 debug_print_list("expand_on_ifs", output, n);
5466 n = o_save_ptr(output, n);
5471 *ended_with_ifs = last_is_ifs;
5472 debug_print_list("expand_on_ifs[1]", output, n);
5476 /* Helper to expand $((...)) and heredoc body. These act as if
5477 * they are in double quotes, with the exception that they are not :).
5478 * Just the rules are similar: "expand only $var and `cmd`"
5480 * Returns malloced string.
5481 * As an optimization, we return NULL if expansion is not needed.
5483 #if !BASH_PATTERN_SUBST
5484 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5485 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5486 encode_then_expand_string(str)
5488 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5490 #if !BASH_PATTERN_SUBST
5491 const int do_unbackslash = 1;
5494 struct in_str input;
5495 o_string dest = NULL_O_STRING;
5497 if (!strchr(str, '$')
5498 && !strchr(str, '\\')
5499 #if ENABLE_HUSH_TICK
5500 && !strchr(str, '`')
5506 /* We need to expand. Example:
5507 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5509 setup_string_in_str(&input, str);
5510 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5511 //TODO: error check (encode_string returns 0 on error)?
5512 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5513 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5514 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5515 o_free_unsafe(&dest);
5519 #if ENABLE_FEATURE_SH_MATH
5520 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5522 arith_state_t math_state;
5526 math_state.lookupvar = get_local_var_value;
5527 math_state.setvar = set_local_var_from_halves;
5528 //math_state.endofname = endofname;
5529 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5530 res = arith(&math_state, exp_str ? exp_str : arg);
5533 *errmsg_p = math_state.errmsg;
5534 if (math_state.errmsg)
5535 msg_and_die_if_script(math_state.errmsg);
5540 #if BASH_PATTERN_SUBST
5541 /* ${var/[/]pattern[/repl]} helpers */
5542 static char *strstr_pattern(char *val, const char *pattern, int *size)
5545 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5546 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5553 /* Optimization: if "*pat" did not match the start of "string",
5554 * we know that "tring", "ring" etc will not match too:
5556 if (pattern[0] == '*')
5561 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5563 char *result = NULL;
5564 unsigned res_len = 0;
5565 unsigned repl_len = strlen(repl);
5569 char *s = strstr_pattern(val, pattern, &size);
5573 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5574 strcpy(mempcpy(result + res_len, val, s - val), repl);
5575 res_len += (s - val) + repl_len;
5576 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5582 if (*val && result) {
5583 result = xrealloc(result, res_len + strlen(val) + 1);
5584 strcpy(result + res_len, val);
5585 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5587 debug_printf_varexp("result:'%s'\n", result);
5590 #endif /* BASH_PATTERN_SUBST */
5593 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5595 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5597 const char *val = NULL;
5598 char *to_be_freed = NULL;
5603 char exp_save = exp_save; /* for compiler */
5604 char *exp_saveptr; /* points to expansion operator */
5605 char *exp_word = exp_word; /* for compiler */
5608 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5610 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5612 first_char = arg[0] = arg0 & 0x7f;
5615 if (first_char == '#' && arg[1] /* ${#...} but not ${#} */
5616 && (!exp_saveptr /* and ( not(${#<op_char>...}) */
5617 || (arg[2] == '\0' && strchr(SPECIAL_VARS_STR, arg[1])) /* or ${#C} "len of $C" ) */
5618 ) /* NB: skipping ^^^specvar check mishandles ${#::2} */
5620 /* It must be length operator: ${#var} */
5624 /* Maybe handle parameter expansion */
5625 if (exp_saveptr /* if 2nd char is one of expansion operators */
5626 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5628 /* ${?:0}, ${#[:]%0} etc */
5629 exp_saveptr = var + 1;
5631 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5632 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5634 exp_op = exp_save = *exp_saveptr;
5636 exp_word = exp_saveptr + 1;
5637 if (exp_op == ':') {
5638 exp_op = *exp_word++;
5639 //TODO: try ${var:} and ${var:bogus} in non-bash config
5641 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5643 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5648 *exp_saveptr = '\0';
5649 } /* else: it's not an expansion op, but bare ${var} */
5652 /* Look up the variable in question */
5653 if (isdigit(var[0])) {
5654 /* parse_dollar should have vetted var for us */
5655 int n = xatoi_positive(var);
5656 if (n < G.global_argc)
5657 val = G.global_argv[n];
5658 /* else val remains NULL: $N with too big N */
5662 val = utoa(G.root_pid);
5664 case '!': /* bg pid */
5665 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5667 case '?': /* exitcode */
5668 val = utoa(G.last_exitcode);
5670 case '#': /* argc */
5671 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5674 val = get_local_var_value(var);
5678 /* Handle any expansions */
5679 if (exp_op == 'L') {
5680 reinit_unicode_for_hush();
5681 debug_printf_expand("expand: length(%s)=", val);
5682 val = utoa(val ? unicode_strlen(val) : 0);
5683 debug_printf_expand("%s\n", val);
5684 } else if (exp_op) {
5685 if (exp_op == '%' || exp_op == '#') {
5686 /* Standard-mandated substring removal ops:
5687 * ${parameter%word} - remove smallest suffix pattern
5688 * ${parameter%%word} - remove largest suffix pattern
5689 * ${parameter#word} - remove smallest prefix pattern
5690 * ${parameter##word} - remove largest prefix pattern
5692 * Word is expanded to produce a glob pattern.
5693 * Then var's value is matched to it and matching part removed.
5695 if (val && val[0]) {
5699 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5700 if (exp_op == *exp_word) /* ## or %% */
5702 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5704 exp_word = exp_exp_word;
5705 /* HACK ALERT. We depend here on the fact that
5706 * G.global_argv and results of utoa and get_local_var_value
5707 * are actually in writable memory:
5708 * scan_and_match momentarily stores NULs there. */
5710 loc = scan_and_match(t, exp_word, scan_flags);
5711 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5712 // exp_op, t, exp_word, loc);
5714 if (loc) { /* match was found */
5715 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5716 val = loc; /* take right part */
5718 val = to_be_freed = xstrndup(val, loc - val); /* left */
5722 #if BASH_PATTERN_SUBST
5723 else if (exp_op == '/' || exp_op == '\\') {
5724 /* It's ${var/[/]pattern[/repl]} thing.
5725 * Note that in encoded form it has TWO parts:
5726 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5727 * and if // is used, it is encoded as \:
5728 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5730 /* Empty variable always gives nothing: */
5731 // "v=''; echo ${v/*/w}" prints "", not "w"
5732 if (val && val[0]) {
5733 /* pattern uses non-standard expansion.
5734 * repl should be unbackslashed and globbed
5735 * by the usual expansion rules:
5737 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5738 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5739 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5740 * v='a bz'; echo ${v/a*z/\z} prints "z"
5741 * (note that a*z _pattern_ is never globbed!)
5743 char *pattern, *repl, *t;
5744 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5746 pattern = xstrdup(exp_word);
5747 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5748 *p++ = SPECIAL_VAR_SYMBOL;
5750 p = strchr(p, SPECIAL_VAR_SYMBOL);
5752 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5753 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5754 /* HACK ALERT. We depend here on the fact that
5755 * G.global_argv and results of utoa and get_local_var_value
5756 * are actually in writable memory:
5757 * replace_pattern momentarily stores NULs there. */
5759 to_be_freed = replace_pattern(t,
5761 (repl ? repl : exp_word),
5763 if (to_be_freed) /* at least one replace happened */
5769 #endif /* BASH_PATTERN_SUBST */
5770 else if (exp_op == ':') {
5771 #if BASH_SUBSTR && ENABLE_FEATURE_SH_MATH
5772 /* It's ${var:N[:M]} bashism.
5773 * Note that in encoded form it has TWO parts:
5774 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5779 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5782 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5783 *p++ = SPECIAL_VAR_SYMBOL;
5785 p = strchr(p, SPECIAL_VAR_SYMBOL);
5787 len = expand_and_evaluate_arith(exp_word, &errmsg);
5790 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5792 /* negative beg counts from the end */
5793 beg = (arith_t)strlen(val) + beg;
5794 if (beg < 0) /* ${v: -999999} is "" */
5797 debug_printf_varexp("from val:'%s'\n", val);
5799 /* in bash, len=-n means strlen()-n */
5800 len = (arith_t)strlen(val) - beg + len;
5801 if (len < 0) /* bash compat */
5802 msg_and_die_if_script("%s: substring expression < 0", var);
5804 if (len <= 0 || !val || beg >= strlen(val)) {
5808 /* Paranoia. What if user entered 9999999999999
5809 * which fits in arith_t but not int? */
5812 val = to_be_freed = xstrndup(val + beg, len);
5814 debug_printf_varexp("val:'%s'\n", val);
5815 #else /* not (HUSH_SUBSTR_EXPANSION && FEATURE_SH_MATH) */
5816 msg_and_die_if_script("malformed ${%s:...}", var);
5819 } else { /* one of "-=+?" */
5820 /* Standard-mandated substitution ops:
5821 * ${var?word} - indicate error if unset
5822 * If var is unset, word (or a message indicating it is unset
5823 * if word is null) is written to standard error
5824 * and the shell exits with a non-zero exit status.
5825 * Otherwise, the value of var is substituted.
5826 * ${var-word} - use default value
5827 * If var is unset, word is substituted.
5828 * ${var=word} - assign and use default value
5829 * If var is unset, word is assigned to var.
5830 * In all cases, final value of var is substituted.
5831 * ${var+word} - use alternative value
5832 * If var is unset, null is substituted.
5833 * Otherwise, word is substituted.
5835 * Word is subjected to tilde expansion, parameter expansion,
5836 * command substitution, and arithmetic expansion.
5837 * If word is not needed, it is not expanded.
5839 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5840 * but also treat null var as if it is unset.
5842 int use_word = (!val || ((exp_save == ':') && !val[0]));
5844 use_word = !use_word;
5845 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5846 (exp_save == ':') ? "true" : "false", use_word);
5848 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5850 exp_word = to_be_freed;
5851 if (exp_op == '?') {
5852 /* mimic bash message */
5853 msg_and_die_if_script("%s: %s",
5857 : "parameter null or not set"
5858 /* ash has more specific messages, a-la: */
5859 /*: (exp_save == ':' ? "parameter null or not set" : "parameter not set")*/
5861 //TODO: how interactive bash aborts expansion mid-command?
5866 if (exp_op == '=') {
5867 /* ${var=[word]} or ${var:=[word]} */
5868 if (isdigit(var[0]) || var[0] == '#') {
5869 /* mimic bash message */
5870 msg_and_die_if_script("$%s: cannot assign in this way", var);
5873 char *new_var = xasprintf("%s=%s", var, val);
5874 set_local_var(new_var, /*flag:*/ 0);
5878 } /* one of "-=+?" */
5880 *exp_saveptr = exp_save;
5886 *to_be_freed_pp = to_be_freed;
5890 /* Expand all variable references in given string, adding words to list[]
5891 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5892 * to be filled). This routine is extremely tricky: has to deal with
5893 * variables/parameters with whitespace, $* and $@, and constructs like
5894 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5895 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5897 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5898 * expansion of right-hand side of assignment == 1-element expand.
5900 char cant_be_null = 0; /* only bit 0x80 matters */
5901 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5904 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5905 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5906 debug_print_list("expand_vars_to_list", output, n);
5907 n = o_save_ptr(output, n);
5908 debug_print_list("expand_vars_to_list[0]", output, n);
5910 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5912 char *to_be_freed = NULL;
5913 const char *val = NULL;
5914 #if ENABLE_HUSH_TICK
5915 o_string subst_result = NULL_O_STRING;
5917 #if ENABLE_FEATURE_SH_MATH
5918 char arith_buf[sizeof(arith_t)*3 + 2];
5922 o_addchr(output, '\0');
5923 n = o_save_ptr(output, n);
5927 o_addblock(output, arg, p - arg);
5928 debug_print_list("expand_vars_to_list[1]", output, n);
5930 p = strchr(p, SPECIAL_VAR_SYMBOL);
5932 /* Fetch special var name (if it is indeed one of them)
5933 * and quote bit, force the bit on if singleword expansion -
5934 * important for not getting v=$@ expand to many words. */
5935 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5937 /* Is this variable quoted and thus expansion can't be null?
5938 * "$@" is special. Even if quoted, it can still
5939 * expand to nothing (not even an empty string),
5940 * thus it is excluded. */
5941 if ((first_ch & 0x7f) != '@')
5942 cant_be_null |= first_ch;
5944 switch (first_ch & 0x7f) {
5945 /* Highest bit in first_ch indicates that var is double-quoted */
5949 if (!G.global_argv[1])
5952 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5953 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5954 while (G.global_argv[i]) {
5955 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5956 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5957 if (G.global_argv[i++][0] && G.global_argv[i]) {
5958 /* this argv[] is not empty and not last:
5959 * put terminating NUL, start new word */
5960 o_addchr(output, '\0');
5961 debug_print_list("expand_vars_to_list[2]", output, n);
5962 n = o_save_ptr(output, n);
5963 debug_print_list("expand_vars_to_list[3]", output, n);
5967 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5968 * and in this case should treat it like '$*' - see 'else...' below */
5969 if (first_ch == ('@'|0x80) /* quoted $@ */
5970 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5973 o_addQstr(output, G.global_argv[i]);
5974 if (++i >= G.global_argc)
5976 o_addchr(output, '\0');
5977 debug_print_list("expand_vars_to_list[4]", output, n);
5978 n = o_save_ptr(output, n);
5980 } else { /* quoted $* (or v="$@" case): add as one word */
5982 o_addQstr(output, G.global_argv[i]);
5983 if (!G.global_argv[++i])
5986 o_addchr(output, G.ifs[0]);
5988 output->has_quoted_part = 1;
5992 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5993 /* "Empty variable", used to make "" etc to not disappear */
5994 output->has_quoted_part = 1;
5996 cant_be_null = 0x80;
5998 #if ENABLE_HUSH_TICK
5999 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
6000 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6002 /* Can't just stuff it into output o_string,
6003 * expanded result may need to be globbed
6005 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
6006 G.last_exitcode = process_command_subs(&subst_result, arg);
6007 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
6008 val = subst_result.data;
6011 #if ENABLE_FEATURE_SH_MATH
6012 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
6015 arg++; /* skip '+' */
6016 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
6017 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
6018 res = expand_and_evaluate_arith(arg, NULL);
6019 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
6020 sprintf(arith_buf, ARITH_FMT, res);
6026 val = expand_one_var(&to_be_freed, arg, &p);
6027 IF_HUSH_TICK(store_val:)
6028 if (!(first_ch & 0x80)) { /* unquoted $VAR */
6029 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
6030 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6031 if (val && val[0]) {
6032 n = expand_on_ifs(&ended_in_ifs, output, n, val);
6035 } else { /* quoted $VAR, val will be appended below */
6036 output->has_quoted_part = 1;
6037 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
6038 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
6041 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
6043 if (val && val[0]) {
6044 o_addQstr(output, val);
6048 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
6049 * Do the check to avoid writing to a const string. */
6050 if (*p != SPECIAL_VAR_SYMBOL)
6051 *p = SPECIAL_VAR_SYMBOL;
6053 #if ENABLE_HUSH_TICK
6054 o_free(&subst_result);
6057 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
6061 o_addchr(output, '\0');
6062 n = o_save_ptr(output, n);
6064 debug_print_list("expand_vars_to_list[a]", output, n);
6065 /* this part is literal, and it was already pre-quoted
6066 * if needed (much earlier), do not use o_addQstr here! */
6067 o_addstr_with_NUL(output, arg);
6068 debug_print_list("expand_vars_to_list[b]", output, n);
6069 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
6070 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
6073 /* allow to reuse list[n] later without re-growth */
6074 output->has_empty_slot = 1;
6076 o_addchr(output, '\0');
6082 static char **expand_variables(char **argv, unsigned expflags)
6086 o_string output = NULL_O_STRING;
6088 output.o_expflags = expflags;
6092 n = expand_vars_to_list(&output, n, *argv);
6095 debug_print_list("expand_variables", &output, n);
6097 /* output.data (malloced in one block) gets returned in "list" */
6098 list = o_finalize_list(&output, n);
6099 debug_print_strings("expand_variables[1]", list);
6103 static char **expand_strvec_to_strvec(char **argv)
6105 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
6109 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
6111 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
6115 /* Used for expansion of right hand of assignments,
6116 * $((...)), heredocs, variable espansion parts.
6118 * NB: should NOT do globbing!
6119 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
6121 static char *expand_string_to_string(const char *str, int do_unbackslash)
6123 #if !BASH_PATTERN_SUBST && !ENABLE_HUSH_CASE
6124 const int do_unbackslash = 1;
6126 char *argv[2], **list;
6128 debug_printf_expand("string_to_string<='%s'\n", str);
6129 /* This is generally an optimization, but it also
6130 * handles "", which otherwise trips over !list[0] check below.
6131 * (is this ever happens that we actually get str="" here?)
6133 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
6134 //TODO: Can use on strings with \ too, just unbackslash() them?
6135 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
6136 return xstrdup(str);
6139 argv[0] = (char*)str;
6141 list = expand_variables(argv, do_unbackslash
6142 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
6143 : EXP_FLAG_SINGLEWORD
6146 if (!list[0] || list[1])
6147 bb_error_msg_and_die("BUG in varexp2");
6148 /* actually, just move string 2*sizeof(char*) bytes back */
6149 overlapping_strcpy((char*)list, list[0]);
6151 unbackslash((char*)list);
6152 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
6156 /* Used for "eval" builtin and case string */
6157 static char* expand_strvec_to_string(char **argv)
6161 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
6162 /* Convert all NULs to spaces */
6167 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
6168 bb_error_msg_and_die("BUG in varexp3");
6169 /* bash uses ' ' regardless of $IFS contents */
6174 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
6175 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
6179 static char **expand_assignments(char **argv, int count)
6184 G.expanded_assignments = p = NULL;
6185 /* Expand assignments into one string each */
6186 for (i = 0; i < count; i++) {
6187 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
6189 G.expanded_assignments = NULL;
6194 static void switch_off_special_sigs(unsigned mask)
6197 while ((mask >>= 1) != 0) {
6201 #if ENABLE_HUSH_TRAP
6203 if (G_traps[sig] && !G_traps[sig][0])
6204 /* trap is '', has to remain SIG_IGN */
6207 G_traps[sig] = NULL;
6210 /* We are here only if no trap or trap was not '' */
6211 install_sighandler(sig, SIG_DFL);
6217 void re_execute_shell(char ***to_free, const char *s,
6218 char *g_argv0, char **g_argv,
6219 char **builtin_argv) NORETURN;
6221 static void reset_traps_to_defaults(void)
6223 /* This function is always called in a child shell
6224 * after fork (not vfork, NOMMU doesn't use this function).
6226 IF_HUSH_TRAP(unsigned sig;)
6229 /* Child shells are not interactive.
6230 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
6231 * Testcase: (while :; do :; done) + ^Z should background.
6232 * Same goes for SIGTERM, SIGHUP, SIGINT.
6234 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
6235 if (!G_traps && !mask)
6236 return; /* already no traps and no special sigs */
6238 /* Switch off special sigs */
6239 switch_off_special_sigs(mask);
6240 # if ENABLE_HUSH_JOB
6241 G_fatal_sig_mask = 0;
6243 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
6244 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
6245 * remain set in G.special_sig_mask */
6247 # if ENABLE_HUSH_TRAP
6251 /* Reset all sigs to default except ones with empty traps */
6252 for (sig = 0; sig < NSIG; sig++) {
6254 continue; /* no trap: nothing to do */
6255 if (!G_traps[sig][0])
6256 continue; /* empty trap: has to remain SIG_IGN */
6257 /* sig has non-empty trap, reset it: */
6259 G_traps[sig] = NULL;
6260 /* There is no signal for trap 0 (EXIT) */
6263 install_sighandler(sig, pick_sighandler(sig));
6270 static void re_execute_shell(char ***to_free, const char *s,
6271 char *g_argv0, char **g_argv,
6272 char **builtin_argv) NORETURN;
6273 static void re_execute_shell(char ***to_free, const char *s,
6274 char *g_argv0, char **g_argv,
6275 char **builtin_argv)
6277 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
6278 /* delims + 2 * (number of bytes in printed hex numbers) */
6279 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
6280 char *heredoc_argv[4];
6281 struct variable *cur;
6282 # if ENABLE_HUSH_FUNCTIONS
6283 struct function *funcp;
6287 unsigned long long empty_trap_mask;
6289 if (!g_argv0) { /* heredoc */
6290 argv = heredoc_argv;
6291 argv[0] = (char *) G.argv0_for_re_execing;
6292 argv[1] = (char *) "-<";
6293 argv[2] = (char *) s;
6295 pp = &argv[3]; /* used as pointer to empty environment */
6301 if (pp) while (*pp++)
6304 empty_trap_mask = 0;
6307 for (sig = 1; sig < NSIG; sig++) {
6308 if (G_traps[sig] && !G_traps[sig][0])
6309 empty_trap_mask |= 1LL << sig;
6313 sprintf(param_buf, NOMMU_HACK_FMT
6314 , (unsigned) G.root_pid
6315 , (unsigned) G.root_ppid
6316 , (unsigned) G.last_bg_pid
6317 , (unsigned) G.last_exitcode
6320 IF_HUSH_LOOPS(, G.depth_of_loop)
6322 # undef NOMMU_HACK_FMT
6323 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
6324 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6327 for (cur = G.top_var; cur; cur = cur->next) {
6328 if (!cur->flg_export || cur->flg_read_only)
6331 # if ENABLE_HUSH_FUNCTIONS
6332 for (funcp = G.top_func; funcp; funcp = funcp->next)
6338 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6339 *pp++ = (char *) G.argv0_for_re_execing;
6341 for (cur = G.top_var; cur; cur = cur->next) {
6342 if (strcmp(cur->varstr, hush_version_str) == 0)
6344 if (cur->flg_read_only) {
6345 *pp++ = (char *) "-R";
6346 *pp++ = cur->varstr;
6347 } else if (!cur->flg_export) {
6348 *pp++ = (char *) "-V";
6349 *pp++ = cur->varstr;
6352 # if ENABLE_HUSH_FUNCTIONS
6353 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6354 *pp++ = (char *) "-F";
6355 *pp++ = funcp->name;
6356 *pp++ = funcp->body_as_string;
6359 /* We can pass activated traps here. Say, -Tnn:trap_string
6361 * However, POSIX says that subshells reset signals with traps
6363 * I tested bash-3.2 and it not only does that with true subshells
6364 * of the form ( list ), but with any forked children shells.
6365 * I set trap "echo W" WINCH; and then tried:
6367 * { echo 1; sleep 20; echo 2; } &
6368 * while true; do echo 1; sleep 20; echo 2; break; done &
6369 * true | { echo 1; sleep 20; echo 2; } | cat
6371 * In all these cases sending SIGWINCH to the child shell
6372 * did not run the trap. If I add trap "echo V" WINCH;
6373 * _inside_ group (just before echo 1), it works.
6375 * I conclude it means we don't need to pass active traps here.
6377 *pp++ = (char *) "-c";
6380 while (*++builtin_argv)
6381 *pp++ = *builtin_argv;
6382 *pp++ = (char *) "";
6387 /* *pp = NULL; - is already there */
6391 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6392 /* Don't propagate SIG_IGN to the child */
6393 if (SPECIAL_JOBSTOP_SIGS != 0)
6394 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6395 execve(bb_busybox_exec_path, argv, pp);
6396 /* Fallback. Useful for init=/bin/hush usage etc */
6397 if (argv[0][0] == '/')
6398 execve(argv[0], argv, pp);
6399 xfunc_error_retval = 127;
6400 bb_error_msg_and_die("can't re-execute the shell");
6402 #endif /* !BB_MMU */
6405 static int run_and_free_list(struct pipe *pi);
6407 /* Executing from string: eval, sh -c '...'
6408 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6409 * end_trigger controls how often we stop parsing
6410 * NUL: parse all, execute, return
6411 * ';': parse till ';' or newline, execute, repeat till EOF
6413 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6415 /* Why we need empty flag?
6416 * An obscure corner case "false; ``; echo $?":
6417 * empty command in `` should still set $? to 0.
6418 * But we can't just set $? to 0 at the start,
6419 * this breaks "false; echo `echo $?`" case.
6423 struct pipe *pipe_list;
6425 #if ENABLE_HUSH_INTERACTIVE
6426 if (end_trigger == ';')
6427 inp->promptmode = 0; /* PS1 */
6429 pipe_list = parse_stream(NULL, inp, end_trigger);
6430 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6431 /* If we are in "big" script
6432 * (not in `cmd` or something similar)...
6434 if (pipe_list == ERR_PTR && end_trigger == ';') {
6435 /* Discard cached input (rest of line) */
6436 int ch = inp->last_char;
6437 while (ch != EOF && ch != '\n') {
6438 //bb_error_msg("Discarded:'%c'", ch);
6443 /* This stream isn't empty */
6447 if (!pipe_list && empty)
6448 G.last_exitcode = 0;
6451 debug_print_tree(pipe_list, 0);
6452 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6453 run_and_free_list(pipe_list);
6455 if (G_flag_return_in_progress == 1)
6460 static void parse_and_run_string(const char *s)
6462 struct in_str input;
6463 setup_string_in_str(&input, s);
6464 parse_and_run_stream(&input, '\0');
6467 static void parse_and_run_file(FILE *f)
6469 struct in_str input;
6470 setup_file_in_str(&input, f);
6471 parse_and_run_stream(&input, ';');
6474 #if ENABLE_HUSH_TICK
6475 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6480 char **to_free = NULL;
6484 pid = BB_MMU ? xfork() : xvfork();
6485 if (pid == 0) { /* child */
6486 disable_restore_tty_pgrp_on_exit();
6487 /* Process substitution is not considered to be usual
6488 * 'command execution'.
6489 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6496 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6497 close(channel[0]); /* NB: close _first_, then move fd! */
6498 xmove_fd(channel[1], 1);
6499 /* Prevent it from trying to handle ctrl-z etc */
6500 IF_HUSH_JOB(G.run_list_level = 1;)
6501 # if ENABLE_HUSH_TRAP
6502 /* Awful hack for `trap` or $(trap).
6504 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6505 * contains an example where "trap" is executed in a subshell:
6507 * save_traps=$(trap)
6509 * eval "$save_traps"
6511 * Standard does not say that "trap" in subshell shall print
6512 * parent shell's traps. It only says that its output
6513 * must have suitable form, but then, in the above example
6514 * (which is not supposed to be normative), it implies that.
6516 * bash (and probably other shell) does implement it
6517 * (traps are reset to defaults, but "trap" still shows them),
6518 * but as a result, "trap" logic is hopelessly messed up:
6521 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6522 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6523 * # true | trap <--- trap is in subshell - no output (ditto)
6524 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6525 * trap -- 'echo Ho' SIGWINCH
6526 * # echo `(trap)` <--- in subshell in subshell - output
6527 * trap -- 'echo Ho' SIGWINCH
6528 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6529 * trap -- 'echo Ho' SIGWINCH
6531 * The rules when to forget and when to not forget traps
6532 * get really complex and nonsensical.
6534 * Our solution: ONLY bare $(trap) or `trap` is special.
6536 s = skip_whitespace(s);
6537 if (is_prefixed_with(s, "trap")
6538 && skip_whitespace(s + 4)[0] == '\0'
6540 static const char *const argv[] = { NULL, NULL };
6541 builtin_trap((char**)argv);
6542 fflush_all(); /* important */
6547 reset_traps_to_defaults();
6548 parse_and_run_string(s);
6549 _exit(G.last_exitcode);
6551 /* We re-execute after vfork on NOMMU. This makes this script safe:
6552 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6553 * huge=`cat BIG` # was blocking here forever
6556 re_execute_shell(&to_free,
6566 # if ENABLE_HUSH_FAST
6568 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6569 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6570 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6572 enable_restore_tty_pgrp_on_exit();
6577 return remember_FILE(xfdopen_for_read(channel[0]));
6580 /* Return code is exit status of the process that is run. */
6581 static int process_command_subs(o_string *dest, const char *s)
6584 struct in_str pipe_str;
6586 int status, ch, eol_cnt;
6588 fp = generate_stream_from_string(s, &pid);
6590 /* Now send results of command back into original context */
6591 setup_file_in_str(&pipe_str, fp);
6593 while ((ch = i_getch(&pipe_str)) != EOF) {
6599 o_addchr(dest, '\n');
6602 o_addQchr(dest, ch);
6605 debug_printf("done reading from `cmd` pipe, closing it\n");
6606 fclose_and_forget(fp);
6607 /* We need to extract exitcode. Test case
6608 * "true; echo `sleep 1; false` $?"
6610 safe_waitpid(pid, &status, 0);
6611 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6612 return WEXITSTATUS(status);
6614 #endif /* ENABLE_HUSH_TICK */
6617 static void setup_heredoc(struct redir_struct *redir)
6619 struct fd_pair pair;
6622 /* the _body_ of heredoc (misleading field name) */
6623 const char *heredoc = redir->rd_filename;
6630 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6631 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6635 len = strlen(heredoc);
6637 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6639 xmove_fd(pair.rd, redir->rd_fd);
6641 /* Try writing without forking. Newer kernels have
6642 * dynamically growing pipes. Must use non-blocking write! */
6645 written = write(pair.wr, heredoc, len);
6656 ndelay_off(pair.wr);
6658 /* Okay, pipe buffer was not big enough */
6659 /* Note: we must not create a stray child (bastard? :)
6660 * for the unsuspecting parent process. Child creates a grandchild
6661 * and exits before parent execs the process which consumes heredoc
6662 * (that exec happens after we return from this function) */
6669 disable_restore_tty_pgrp_on_exit();
6670 pid = BB_MMU ? xfork() : xvfork();
6674 close(redir->rd_fd); /* read side of the pipe */
6676 full_write(pair.wr, heredoc, len); /* may loop or block */
6679 /* Delegate blocking writes to another process */
6680 xmove_fd(pair.wr, STDOUT_FILENO);
6681 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6685 #if ENABLE_HUSH_FAST
6687 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6689 enable_restore_tty_pgrp_on_exit();
6695 wait(NULL); /* wait till child has died */
6701 /* moved_to = n: fd was moved to n; restore back to orig_fd after redir */
6702 /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */
6705 static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved)
6707 sq = xrealloc(sq, (i + 2) * sizeof(sq[0]));
6708 sq[i].orig_fd = orig;
6709 sq[i].moved_to = moved;
6710 sq[i+1].orig_fd = -1; /* end marker */
6714 static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd)
6719 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6720 /* If we collide with an already moved fd... */
6721 if (fd == sq[i].moved_to) {
6722 sq[i].moved_to = fcntl_F_DUPFD(sq[i].moved_to, avoid_fd);
6723 debug_printf_redir("redirect_fd %d: already busy, moving to %d\n", fd, sq[i].moved_to);
6724 if (sq[i].moved_to < 0) /* what? */
6728 if (fd == sq[i].orig_fd) {
6729 /* Example: echo Hello >/dev/null 1>&2 */
6730 debug_printf_redir("redirect_fd %d: already moved\n", fd);
6735 /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */
6736 moved_to = fcntl_F_DUPFD(fd, avoid_fd);
6737 debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to);
6738 if (moved_to < 0 && errno != EBADF)
6740 return append_squirrel(sq, i, fd, moved_to);
6743 static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd)
6747 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6748 /* If we collide with an already moved fd... */
6749 if (fd == sq[i].orig_fd) {
6751 * "echo 3>FILE 3>&- 3>FILE"
6752 * "echo 3>&- 3>FILE"
6753 * No need for last redirect to insert
6754 * another "need to close 3" indicator.
6756 debug_printf_redir("redirect_fd %d: already moved or closed\n", fd);
6761 debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd);
6762 return append_squirrel(sq, i, fd, -1);
6765 /* fd: redirect wants this fd to be used (e.g. 3>file).
6766 * Move all conflicting internally used fds,
6767 * and remember them so that we can restore them later.
6769 static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp)
6771 if (avoid_fd < 9) /* the important case here is that it can be -1 */
6774 #if ENABLE_HUSH_INTERACTIVE
6775 if (fd == G.interactive_fd) {
6776 /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */
6777 G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd);
6778 debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd);
6779 return 1; /* "we closed fd" */
6782 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6783 * (1) Redirect in a forked child. No need to save FILEs' fds,
6784 * we aren't going to use them anymore, ok to trash.
6785 * (2) "exec 3>FILE". Bummer. We can save script FILEs' fds,
6786 * but how are we doing to restore them?
6787 * "fileno(fd) = new_fd" can't be done.
6792 /* If this one of script's fds? */
6793 if (save_FILEs_on_redirect(fd, avoid_fd))
6794 return 1; /* yes. "we closed fd" */
6796 /* Check whether it collides with any open fds (e.g. stdio), save fds as needed */
6797 *sqp = add_squirrel(*sqp, fd, avoid_fd);
6798 return 0; /* "we did not close fd" */
6801 static void restore_redirects(struct squirrel *sq)
6805 for (i = 0; sq[i].orig_fd >= 0; i++) {
6806 if (sq[i].moved_to >= 0) {
6807 /* We simply die on error */
6808 debug_printf_redir("restoring redirected fd from %d to %d\n", sq[i].moved_to, sq[i].orig_fd);
6809 xmove_fd(sq[i].moved_to, sq[i].orig_fd);
6811 /* cmd1 9>FILE; cmd2_should_see_fd9_closed */
6812 debug_printf_redir("restoring redirected fd %d: closing it\n", sq[i].orig_fd);
6813 close(sq[i].orig_fd);
6819 /* If moved, G.interactive_fd stays on new fd, not restoring it */
6821 restore_redirected_FILEs();
6824 #if ENABLE_FEATURE_SH_STANDALONE && BB_MMU
6825 static void close_saved_fds_and_FILE_fds(void)
6827 if (G_interactive_fd)
6828 close(G_interactive_fd);
6829 close_all_FILE_list();
6833 static int internally_opened_fd(int fd, struct squirrel *sq)
6837 #if ENABLE_HUSH_INTERACTIVE
6838 if (fd == G.interactive_fd)
6841 /* If this one of script's fds? */
6842 if (fd_in_FILEs(fd))
6845 if (sq) for (i = 0; sq[i].orig_fd >= 0; i++) {
6846 if (fd == sq[i].moved_to)
6852 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6853 * and stderr if they are redirected. */
6854 static int setup_redirects(struct command *prog, struct squirrel **sqp)
6856 struct redir_struct *redir;
6858 for (redir = prog->redirects; redir; redir = redir->next) {
6862 if (redir->rd_type == REDIRECT_HEREDOC2) {
6863 /* "rd_fd<<HERE" case */
6864 save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp);
6865 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6867 debug_printf_parse("set heredoc '%s'\n",
6868 redir->rd_filename);
6869 setup_heredoc(redir);
6873 if (redir->rd_dup == REDIRFD_TO_FILE) {
6874 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6878 if (redir->rd_filename == NULL) {
6881 * "cmd >" (no filename)
6882 * "cmd > <file" (2nd redirect starts too early)
6884 syntax_error("invalid redirect");
6887 mode = redir_table[redir->rd_type].mode;
6888 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6889 newfd = open_or_warn(p, mode);
6892 /* Error message from open_or_warn can be lost
6893 * if stderr has been redirected, but bash
6894 * and ash both lose it as well
6895 * (though zsh doesn't!)
6899 if (newfd == redir->rd_fd && sqp) {
6900 /* open() gave us precisely the fd we wanted.
6901 * This means that this fd was not busy
6902 * (not opened to anywhere).
6903 * Remember to close it on restore:
6905 *sqp = add_squirrel_closed(*sqp, newfd);
6906 debug_printf_redir("redir to previously closed fd %d\n", newfd);
6909 /* "rd_fd>&rd_dup" or "rd_fd>&-" case */
6910 newfd = redir->rd_dup;
6913 if (newfd == redir->rd_fd)
6916 /* if "N>FILE": move newfd to redir->rd_fd */
6917 /* if "N>&M": dup newfd to redir->rd_fd */
6918 /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */
6920 closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp);
6921 if (newfd == REDIRFD_CLOSE) {
6922 /* "N>&-" means "close me" */
6924 /* ^^^ optimization: saving may already
6925 * have closed it. If not... */
6926 close(redir->rd_fd);
6928 /* Sometimes we do another close on restore, getting EBADF.
6929 * Consider "echo 3>FILE 3>&-"
6930 * first redirect remembers "need to close 3",
6931 * and second redirect closes 3! Restore code then closes 3 again.
6934 /* if newfd is a script fd or saved fd, simulate EBADF */
6935 if (internally_opened_fd(newfd, sqp ? *sqp : NULL)) {
6937 //bb_perror_msg_and_die("can't duplicate file descriptor");
6938 newfd = -1; /* same effect as code above */
6940 xdup2(newfd, redir->rd_fd);
6941 if (redir->rd_dup == REDIRFD_TO_FILE)
6942 /* "rd_fd > FILE" */
6944 /* else: "rd_fd > rd_dup" */
6950 static char *find_in_path(const char *arg)
6953 const char *PATH = get_local_var_value("PATH");
6959 const char *end = strchrnul(PATH, ':');
6960 int sz = end - PATH; /* must be int! */
6964 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6966 /* We have xxx::yyyy in $PATH,
6967 * it means "use current dir" */
6970 if (access(ret, F_OK) == 0)
6983 static const struct built_in_command *find_builtin_helper(const char *name,
6984 const struct built_in_command *x,
6985 const struct built_in_command *end)
6988 if (strcmp(name, x->b_cmd) != 0) {
6992 debug_printf_exec("found builtin '%s'\n", name);
6997 static const struct built_in_command *find_builtin1(const char *name)
6999 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
7001 static const struct built_in_command *find_builtin(const char *name)
7003 const struct built_in_command *x = find_builtin1(name);
7006 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
7009 #if ENABLE_HUSH_FUNCTIONS
7010 static struct function **find_function_slot(const char *name)
7012 struct function **funcpp = &G.top_func;
7014 if (strcmp(name, (*funcpp)->name) == 0) {
7017 funcpp = &(*funcpp)->next;
7022 static const struct function *find_function(const char *name)
7024 const struct function *funcp = *find_function_slot(name);
7026 debug_printf_exec("found function '%s'\n", name);
7030 /* Note: takes ownership on name ptr */
7031 static struct function *new_function(char *name)
7033 struct function **funcpp = find_function_slot(name);
7034 struct function *funcp = *funcpp;
7036 if (funcp != NULL) {
7037 struct command *cmd = funcp->parent_cmd;
7038 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
7040 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
7042 /* Note: if !funcp->body, do not free body_as_string!
7043 * This is a special case of "-F name body" function:
7044 * body_as_string was not malloced! */
7046 free_pipe_list(funcp->body);
7048 free(funcp->body_as_string);
7052 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
7053 cmd->argv[0] = funcp->name;
7054 cmd->group = funcp->body;
7056 cmd->group_as_string = funcp->body_as_string;
7060 debug_printf_exec("remembering new function '%s'\n", name);
7061 funcp = *funcpp = xzalloc(sizeof(*funcp));
7062 /*funcp->next = NULL;*/
7069 # if ENABLE_HUSH_UNSET
7070 static void unset_func(const char *name)
7072 struct function **funcpp = find_function_slot(name);
7073 struct function *funcp = *funcpp;
7075 if (funcp != NULL) {
7076 debug_printf_exec("freeing function '%s'\n", funcp->name);
7077 *funcpp = funcp->next;
7078 /* funcp is unlinked now, deleting it.
7079 * Note: if !funcp->body, the function was created by
7080 * "-F name body", do not free ->body_as_string
7081 * and ->name as they were not malloced. */
7083 free_pipe_list(funcp->body);
7086 free(funcp->body_as_string);
7095 #define exec_function(to_free, funcp, argv) \
7096 exec_function(funcp, argv)
7098 static void exec_function(char ***to_free,
7099 const struct function *funcp,
7100 char **argv) NORETURN;
7101 static void exec_function(char ***to_free,
7102 const struct function *funcp,
7108 argv[0] = G.global_argv[0];
7109 G.global_argv = argv;
7110 G.global_argc = n = 1 + string_array_len(argv + 1);
7112 // Example when we are here: "cmd | func"
7113 // func will run with saved-redirect fds open.
7114 // $ f() { echo /proc/self/fd/*; }
7116 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3
7117 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ DIR fd for glob
7120 // /proc/self/fd/0 /proc/self/fd/1 /proc/self/fd/2 /proc/self/fd/255 /proc/self/fd/3 /proc/self/fd/4
7121 // stdio^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ G_interactive_fd^ opened ./SCRIPT DIR fd for glob
7122 // They are CLOEXEC so external programs won't see them, but
7123 // for "more correctness" we might want to close those extra fds here:
7124 //? close_saved_fds_and_FILE_fds();
7126 /* "we are in function, ok to use return" */
7127 G_flag_return_in_progress = -1;
7128 IF_HUSH_LOCAL(G.func_nest_level++;)
7130 /* On MMU, funcp->body is always non-NULL */
7131 n = run_list(funcp->body);
7135 //? close_saved_fds_and_FILE_fds();
7137 //TODO: check whether "true | func_with_return" works
7139 re_execute_shell(to_free,
7140 funcp->body_as_string,
7147 static int run_function(const struct function *funcp, char **argv)
7153 save_and_replace_G_args(&sv, argv);
7155 /* "we are in function, ok to use return" */
7156 sv_flg = G_flag_return_in_progress;
7157 G_flag_return_in_progress = -1;
7158 IF_HUSH_LOCAL(G.func_nest_level++;)
7160 /* On MMU, funcp->body is always non-NULL */
7163 /* Function defined by -F */
7164 parse_and_run_string(funcp->body_as_string);
7165 rc = G.last_exitcode;
7169 rc = run_list(funcp->body);
7172 # if ENABLE_HUSH_LOCAL
7174 struct variable *var;
7175 struct variable **var_pp;
7177 var_pp = &G.top_var;
7178 while ((var = *var_pp) != NULL) {
7179 if (var->func_nest_level < G.func_nest_level) {
7180 var_pp = &var->next;
7184 if (var->flg_export)
7185 bb_unsetenv(var->varstr);
7186 /* Remove from global list */
7187 *var_pp = var->next;
7193 G.func_nest_level--;
7196 G_flag_return_in_progress = sv_flg;
7198 restore_G_args(&sv, argv);
7202 #endif /* ENABLE_HUSH_FUNCTIONS */
7206 #define exec_builtin(to_free, x, argv) \
7207 exec_builtin(x, argv)
7209 #define exec_builtin(to_free, x, argv) \
7210 exec_builtin(to_free, argv)
7212 static void exec_builtin(char ***to_free,
7213 const struct built_in_command *x,
7214 char **argv) NORETURN;
7215 static void exec_builtin(char ***to_free,
7216 const struct built_in_command *x,
7222 //? close_saved_fds_and_FILE_fds();
7223 rcode = x->b_function(argv);
7228 /* On NOMMU, we must never block!
7229 * Example: { sleep 99 | read line; } & echo Ok
7231 re_execute_shell(to_free,
7240 static void execvp_or_die(char **argv) NORETURN;
7241 static void execvp_or_die(char **argv)
7244 debug_printf_exec("execing '%s'\n", argv[0]);
7245 /* Don't propagate SIG_IGN to the child */
7246 if (SPECIAL_JOBSTOP_SIGS != 0)
7247 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7248 execvp(argv[0], argv);
7250 if (errno == EACCES) e = 126;
7251 if (errno == ENOENT) e = 127;
7252 bb_perror_msg("can't execute '%s'", argv[0]);
7256 #if ENABLE_HUSH_MODE_X
7257 static void dump_cmd_in_x_mode(char **argv)
7259 if (G_x_mode && argv) {
7260 /* We want to output the line in one write op */
7268 len += strlen(argv[n++]) + 1;
7274 p += sprintf(p, " %s", argv[n++]);
7282 # define dump_cmd_in_x_mode(argv) ((void)0)
7286 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
7287 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
7288 #define pseudo_exec(nommu_save, command, argv_expanded) \
7289 pseudo_exec(command, argv_expanded)
7292 /* Called after [v]fork() in run_pipe, or from builtin_exec.
7294 * Don't exit() here. If you don't exec, use _exit instead.
7295 * The at_exit handlers apparently confuse the calling process,
7296 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
7298 static void pseudo_exec_argv(nommu_save_t *nommu_save,
7299 char **argv, int assignment_cnt,
7300 char **argv_expanded) NORETURN;
7301 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
7302 char **argv, int assignment_cnt,
7303 char **argv_expanded)
7307 new_env = expand_assignments(argv, assignment_cnt);
7308 dump_cmd_in_x_mode(new_env);
7310 if (!argv[assignment_cnt]) {
7311 /* Case when we are here: ... | var=val | ...
7312 * (note that we do not exit early, i.e., do not optimize out
7313 * expand_assignments(): think about ... | var=`sleep 1` | ...
7315 free_strings(new_env);
7316 _exit(EXIT_SUCCESS);
7320 set_vars_and_save_old(new_env);
7321 free(new_env); /* optional */
7322 /* we can also destroy set_vars_and_save_old's return value,
7325 nommu_save->new_env = new_env;
7326 nommu_save->old_vars = set_vars_and_save_old(new_env);
7329 if (argv_expanded) {
7330 argv = argv_expanded;
7332 argv = expand_strvec_to_strvec(argv + assignment_cnt);
7334 nommu_save->argv = argv;
7337 dump_cmd_in_x_mode(argv);
7339 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7340 if (strchr(argv[0], '/') != NULL)
7344 #if ENABLE_HUSH_FUNCTIONS
7345 /* Check if the command matches any functions (this goes before bltins) */
7347 const struct function *funcp = find_function(argv[0]);
7349 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
7354 /* Check if the command matches any of the builtins.
7355 * Depending on context, this might be redundant. But it's
7356 * easier to waste a few CPU cycles than it is to figure out
7357 * if this is one of those cases.
7360 /* On NOMMU, it is more expensive to re-execute shell
7361 * just in order to run echo or test builtin.
7362 * It's better to skip it here and run corresponding
7363 * non-builtin later. */
7364 const struct built_in_command *x;
7365 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
7367 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
7371 #if ENABLE_FEATURE_SH_STANDALONE
7372 /* Check if the command matches any busybox applets */
7374 int a = find_applet_by_name(argv[0]);
7376 # if BB_MMU /* see above why on NOMMU it is not allowed */
7377 if (APPLET_IS_NOEXEC(a)) {
7378 /* Do not leak open fds from opened script files etc.
7379 * Testcase: interactive "ls -l /proc/self/fd"
7380 * should not show tty fd open.
7382 close_saved_fds_and_FILE_fds();
7383 //FIXME: should also close saved redir fds
7384 /* Without this, "rm -i FILE" can't be ^C'ed: */
7385 switch_off_special_sigs(G.special_sig_mask);
7386 debug_printf_exec("running applet '%s'\n", argv[0]);
7387 run_applet_no_and_exit(a, argv[0], argv);
7390 /* Re-exec ourselves */
7391 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
7392 /* Don't propagate SIG_IGN to the child */
7393 if (SPECIAL_JOBSTOP_SIGS != 0)
7394 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
7395 execv(bb_busybox_exec_path, argv);
7396 /* If they called chroot or otherwise made the binary no longer
7397 * executable, fall through */
7402 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
7405 execvp_or_die(argv);
7408 /* Called after [v]fork() in run_pipe
7410 static void pseudo_exec(nommu_save_t *nommu_save,
7411 struct command *command,
7412 char **argv_expanded) NORETURN;
7413 static void pseudo_exec(nommu_save_t *nommu_save,
7414 struct command *command,
7415 char **argv_expanded)
7417 if (command->argv) {
7418 pseudo_exec_argv(nommu_save, command->argv,
7419 command->assignment_cnt, argv_expanded);
7422 if (command->group) {
7423 /* Cases when we are here:
7426 * ... | ( list ) | ...
7427 * ... | { list } | ...
7431 debug_printf_exec("pseudo_exec: run_list\n");
7432 reset_traps_to_defaults();
7433 rcode = run_list(command->group);
7434 /* OK to leak memory by not calling free_pipe_list,
7435 * since this process is about to exit */
7438 re_execute_shell(&nommu_save->argv_from_re_execing,
7439 command->group_as_string,
7446 /* Case when we are here: ... | >file */
7447 debug_printf_exec("pseudo_exec'ed null command\n");
7448 _exit(EXIT_SUCCESS);
7452 static const char *get_cmdtext(struct pipe *pi)
7458 /* This is subtle. ->cmdtext is created only on first backgrounding.
7459 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
7460 * On subsequent bg argv is trashed, but we won't use it */
7464 argv = pi->cmds[0].argv;
7466 pi->cmdtext = xzalloc(1);
7471 len += strlen(*argv) + 1;
7475 argv = pi->cmds[0].argv;
7477 p = stpcpy(p, *argv);
7484 static void remove_job_from_table(struct pipe *pi)
7486 struct pipe *prev_pipe;
7488 if (pi == G.job_list) {
7489 G.job_list = pi->next;
7491 prev_pipe = G.job_list;
7492 while (prev_pipe->next != pi)
7493 prev_pipe = prev_pipe->next;
7494 prev_pipe->next = pi->next;
7498 G.last_jobid = G.job_list->jobid;
7501 static void delete_finished_job(struct pipe *pi)
7503 remove_job_from_table(pi);
7507 static void clean_up_last_dead_job(void)
7509 if (G.job_list && !G.job_list->alive_cmds)
7510 delete_finished_job(G.job_list);
7513 static void insert_job_into_table(struct pipe *pi)
7515 struct pipe *job, **jobp;
7518 clean_up_last_dead_job();
7520 /* Find the end of the list, and find next job ID to use */
7523 while ((job = *jobp) != NULL) {
7530 /* Create a new job struct at the end */
7531 job = *jobp = xmemdup(pi, sizeof(*pi));
7533 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7534 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7535 for (i = 0; i < pi->num_cmds; i++) {
7536 job->cmds[i].pid = pi->cmds[i].pid;
7537 /* all other fields are not used and stay zero */
7539 job->cmdtext = xstrdup(get_cmdtext(pi));
7541 if (G_interactive_fd)
7542 printf("[%u] %u %s\n", job->jobid, (unsigned)job->cmds[0].pid, job->cmdtext);
7543 G.last_jobid = job->jobid;
7547 static int job_exited_or_stopped(struct pipe *pi)
7551 if (pi->alive_cmds != pi->stopped_cmds)
7554 /* All processes in fg pipe have exited or stopped */
7558 rcode = pi->cmds[i].cmd_exitcode;
7559 /* usually last process gives overall exitstatus,
7560 * but with "set -o pipefail", last *failed* process does */
7561 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7564 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7568 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7575 dead = WIFEXITED(status) || WIFSIGNALED(status);
7578 if (WIFSTOPPED(status))
7579 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7580 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7581 if (WIFSIGNALED(status))
7582 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7583 childpid, WTERMSIG(status), WEXITSTATUS(status));
7584 if (WIFEXITED(status))
7585 debug_printf_jobs("pid %d exited, exitcode %d\n",
7586 childpid, WEXITSTATUS(status));
7588 /* Were we asked to wait for a fg pipe? */
7590 i = fg_pipe->num_cmds;
7595 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7596 if (fg_pipe->cmds[i].pid != childpid)
7600 fg_pipe->cmds[i].pid = 0;
7601 fg_pipe->alive_cmds--;
7602 ex = WEXITSTATUS(status);
7603 /* bash prints killer signal's name for *last*
7604 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7605 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7607 if (WIFSIGNALED(status)) {
7608 int sig = WTERMSIG(status);
7609 if (i == fg_pipe->num_cmds-1)
7610 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7611 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7612 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7613 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7614 * Maybe we need to use sig | 128? */
7617 fg_pipe->cmds[i].cmd_exitcode = ex;
7619 fg_pipe->stopped_cmds++;
7621 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7622 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7623 rcode = job_exited_or_stopped(fg_pipe);
7625 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7626 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7627 * and "killall -STOP cat" */
7628 if (G_interactive_fd) {
7630 if (fg_pipe->alive_cmds != 0)
7631 insert_job_into_table(fg_pipe);
7635 if (fg_pipe->alive_cmds == 0)
7638 /* There are still running processes in the fg_pipe */
7641 /* It wasn't in fg_pipe, look for process in bg pipes */
7645 /* We were asked to wait for bg or orphaned children */
7646 /* No need to remember exitcode in this case */
7647 for (pi = G.job_list; pi; pi = pi->next) {
7648 for (i = 0; i < pi->num_cmds; i++) {
7649 if (pi->cmds[i].pid == childpid)
7650 goto found_pi_and_prognum;
7653 /* Happens when shell is used as init process (init=/bin/sh) */
7654 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7655 return -1; /* this wasn't a process from fg_pipe */
7657 found_pi_and_prognum:
7660 int rcode = WEXITSTATUS(status);
7661 if (WIFSIGNALED(status))
7662 rcode = 128 + WTERMSIG(status);
7663 pi->cmds[i].cmd_exitcode = rcode;
7664 if (G.last_bg_pid == pi->cmds[i].pid)
7665 G.last_bg_pid_exitcode = rcode;
7666 pi->cmds[i].pid = 0;
7668 if (!pi->alive_cmds) {
7669 if (G_interactive_fd) {
7670 printf(JOB_STATUS_FORMAT, pi->jobid,
7671 "Done", pi->cmdtext);
7672 delete_finished_job(pi);
7675 * bash deletes finished jobs from job table only in interactive mode,
7676 * after "jobs" cmd, or if pid of a new process matches one of the old ones
7677 * (see cleanup_dead_jobs(), delete_old_job(), J_NOTIFIED in bash source).
7678 * Testcase script: "(exit 3) & sleep 1; wait %1; echo $?" prints 3 in bash.
7679 * We only retain one "dead" job, if it's the single job on the list.
7680 * This covers most of real-world scenarios where this is useful.
7682 if (pi != G.job_list)
7683 delete_finished_job(pi);
7691 return -1; /* this wasn't a process from fg_pipe */
7694 /* Check to see if any processes have exited -- if they have,
7695 * figure out why and see if a job has completed.
7697 * If non-NULL fg_pipe: wait for its completion or stop.
7698 * Return its exitcode or zero if stopped.
7700 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7701 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7702 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7703 * or 0 if no children changed status.
7705 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7706 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7707 * or 0 if no children changed status.
7709 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7715 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7717 attributes = WUNTRACED;
7718 if (fg_pipe == NULL)
7719 attributes |= WNOHANG;
7722 #if ENABLE_HUSH_FAST
7723 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7724 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7725 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7726 /* There was neither fork nor SIGCHLD since last waitpid */
7727 /* Avoid doing waitpid syscall if possible */
7728 if (!G.we_have_children) {
7732 if (fg_pipe == NULL) { /* is WNOHANG set? */
7733 /* We have children, but they did not exit
7734 * or stop yet (we saw no SIGCHLD) */
7737 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7741 /* Do we do this right?
7742 * bash-3.00# sleep 20 | false
7744 * [3]+ Stopped sleep 20 | false
7745 * bash-3.00# echo $?
7746 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7747 * [hush 1.14.0: yes we do it right]
7751 #if ENABLE_HUSH_FAST
7753 i = G.count_SIGCHLD;
7755 childpid = waitpid(-1, &status, attributes);
7756 if (childpid <= 0) {
7757 if (childpid && errno != ECHILD)
7758 bb_perror_msg("waitpid");
7759 #if ENABLE_HUSH_FAST
7760 else { /* Until next SIGCHLD, waitpid's are useless */
7761 G.we_have_children = (childpid == 0);
7762 G.handled_SIGCHLD = i;
7763 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7766 /* ECHILD (no children), or 0 (no change in children status) */
7770 rcode = process_wait_result(fg_pipe, childpid, status);
7772 /* fg_pipe exited or stopped */
7775 if (childpid == waitfor_pid) {
7776 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7777 rcode = WEXITSTATUS(status);
7778 if (WIFSIGNALED(status))
7779 rcode = 128 + WTERMSIG(status);
7780 if (WIFSTOPPED(status))
7781 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7782 rcode = 128 + WSTOPSIG(status);
7784 break; /* "wait PID" called us, give it exitcode+1 */
7786 /* This wasn't one of our processes, or */
7787 /* fg_pipe still has running processes, do waitpid again */
7788 } /* while (waitpid succeeds)... */
7794 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7797 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7798 if (G_saved_tty_pgrp) {
7799 /* Job finished, move the shell to the foreground */
7800 p = getpgrp(); /* our process group id */
7801 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7802 tcsetpgrp(G_interactive_fd, p);
7808 /* Start all the jobs, but don't wait for anything to finish.
7811 * Return code is normally -1, when the caller has to wait for children
7812 * to finish to determine the exit status of the pipe. If the pipe
7813 * is a simple builtin command, however, the action is done by the
7814 * time run_pipe returns, and the exit code is provided as the
7817 * Returns -1 only if started some children. IOW: we have to
7818 * mask out retvals of builtins etc with 0xff!
7820 * The only case when we do not need to [v]fork is when the pipe
7821 * is single, non-backgrounded, non-subshell command. Examples:
7822 * cmd ; ... { list } ; ...
7823 * cmd && ... { list } && ...
7824 * cmd || ... { list } || ...
7825 * If it is, then we can run cmd as a builtin, NOFORK,
7826 * or (if SH_STANDALONE) an applet, and we can run the { list }
7827 * with run_list. If it isn't one of these, we fork and exec cmd.
7829 * Cases when we must fork:
7830 * non-single: cmd | cmd
7831 * backgrounded: cmd & { list } &
7832 * subshell: ( list ) [&]
7834 #if !ENABLE_HUSH_MODE_X
7835 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7836 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7838 static int redirect_and_varexp_helper(char ***new_env_p,
7839 struct variable **old_vars_p,
7840 struct command *command,
7841 struct squirrel **sqp,
7842 char **argv_expanded)
7844 /* setup_redirects acts on file descriptors, not FILEs.
7845 * This is perfect for work that comes after exec().
7846 * Is it really safe for inline use? Experimentally,
7847 * things seem to work. */
7848 int rcode = setup_redirects(command, sqp);
7850 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7851 *new_env_p = new_env;
7852 dump_cmd_in_x_mode(new_env);
7853 dump_cmd_in_x_mode(argv_expanded);
7855 *old_vars_p = set_vars_and_save_old(new_env);
7859 static NOINLINE int run_pipe(struct pipe *pi)
7861 static const char *const null_ptr = NULL;
7865 struct command *command;
7866 char **argv_expanded;
7868 struct squirrel *squirrel = NULL;
7871 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7874 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7875 * Result should be 3 lines: q w e, qwe, q w e
7877 G.ifs = get_local_var_value("IFS");
7881 IF_HUSH_JOB(pi->pgrp = -1;)
7882 pi->stopped_cmds = 0;
7883 command = &pi->cmds[0];
7884 argv_expanded = NULL;
7886 if (pi->num_cmds != 1
7887 || pi->followup == PIPE_BG
7888 || command->cmd_type == CMD_SUBSHELL
7895 debug_printf_exec(": group:%p argv:'%s'\n",
7896 command->group, command->argv ? command->argv[0] : "NONE");
7898 if (command->group) {
7899 #if ENABLE_HUSH_FUNCTIONS
7900 if (command->cmd_type == CMD_FUNCDEF) {
7901 /* "executing" func () { list } */
7902 struct function *funcp;
7904 funcp = new_function(command->argv[0]);
7905 /* funcp->name is already set to argv[0] */
7906 funcp->body = command->group;
7908 funcp->body_as_string = command->group_as_string;
7909 command->group_as_string = NULL;
7911 command->group = NULL;
7912 command->argv[0] = NULL;
7913 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7914 funcp->parent_cmd = command;
7915 command->child_func = funcp;
7917 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7919 return EXIT_SUCCESS;
7923 debug_printf("non-subshell group\n");
7924 rcode = 1; /* exitcode if redir failed */
7925 if (setup_redirects(command, &squirrel) == 0) {
7926 debug_printf_exec(": run_list\n");
7927 rcode = run_list(command->group) & 0xff;
7929 restore_redirects(squirrel);
7930 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7932 debug_printf_exec("run_pipe: return %d\n", rcode);
7936 argv = command->argv ? command->argv : (char **) &null_ptr;
7938 const struct built_in_command *x;
7939 #if ENABLE_HUSH_FUNCTIONS
7940 const struct function *funcp;
7944 char **new_env = NULL;
7945 struct variable *old_vars = NULL;
7947 if (argv[command->assignment_cnt] == NULL) {
7948 /* Assignments, but no command */
7949 /* Ensure redirects take effect (that is, create files).
7950 * Try "a=t >file" */
7951 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7952 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, &squirrel, /*argv_expanded:*/ NULL);
7953 /* Set shell variables */
7957 if (set_local_var(*argv, /*flag:*/ 0)) {
7958 /* assignment to readonly var / putenv error? */
7964 /* Redirect error sets $? to 1. Otherwise,
7965 * if evaluating assignment value set $?, retain it.
7966 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7968 rcode = G.last_exitcode;
7969 /* Exit, _skipping_ variable restoring code: */
7970 goto clean_up_and_ret0;
7972 #else /* Older, bigger, but more correct code */
7974 rcode = setup_redirects(command, &squirrel);
7975 restore_redirects(squirrel);
7976 /* Set shell variables */
7978 bb_putchar_stderr('+');
7980 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7982 fprintf(stderr, " %s", p);
7983 debug_printf_exec("set shell var:'%s'->'%s'\n",
7985 if (set_local_var(p, /*flag:*/ 0)) {
7986 /* assignment to readonly var / putenv error? */
7992 bb_putchar_stderr('\n');
7993 /* Redirect error sets $? to 1. Otherwise,
7994 * if evaluating assignment value set $?, retain it.
7995 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7997 rcode = G.last_exitcode;
7998 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8000 debug_printf_exec("run_pipe: return %d\n", rcode);
8005 /* Expand the rest into (possibly) many strings each */
8007 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
8008 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
8012 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
8015 /* if someone gives us an empty string: `cmd with empty output` */
8016 if (!argv_expanded[0]) {
8017 free(argv_expanded);
8019 return G.last_exitcode;
8022 #if ENABLE_HUSH_FUNCTIONS
8023 /* Check if argv[0] matches any functions (this goes before bltins) */
8024 funcp = find_function(argv_expanded[0]);
8028 x = find_builtin(argv_expanded[0]);
8031 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
8032 debug_printf("exec with redirects only\n");
8033 rcode = setup_redirects(command, NULL);
8034 /* rcode=1 can be if redir file can't be opened */
8035 goto clean_up_and_ret1;
8038 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8041 debug_printf_exec(": builtin '%s' '%s'...\n",
8042 x->b_cmd, argv_expanded[1]);
8044 rcode = x->b_function(argv_expanded) & 0xff;
8047 #if ENABLE_HUSH_FUNCTIONS
8049 # if ENABLE_HUSH_LOCAL
8050 struct variable **sv;
8051 sv = G.shadowed_vars_pp;
8052 G.shadowed_vars_pp = &old_vars;
8054 debug_printf_exec(": function '%s' '%s'...\n",
8055 funcp->name, argv_expanded[1]);
8056 rcode = run_function(funcp, argv_expanded) & 0xff;
8057 # if ENABLE_HUSH_LOCAL
8058 G.shadowed_vars_pp = sv;
8064 unset_vars(new_env);
8066 /* clean_up_and_ret0: */
8067 restore_redirects(squirrel);
8069 * Try "usleep 99999999" + ^C + "echo $?"
8070 * with FEATURE_SH_NOFORK=y.
8073 /* It was builtin or nofork.
8074 * if this would be a real fork/execed program,
8075 * it should have died if a fatal sig was received.
8076 * But OTOH, there was no separate process,
8077 * the sig was sent to _shell_, not to non-existing
8079 * Let's just handle ^C only, this one is obvious:
8080 * we aren't ok with exitcode 0 when ^C was pressed
8081 * during builtin/nofork.
8083 if (sigismember(&G.pending_set, SIGINT))
8084 rcode = 128 + SIGINT;
8087 free(argv_expanded);
8088 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
8090 debug_printf_exec("run_pipe return %d\n", rcode);
8094 if (ENABLE_FEATURE_SH_NOFORK) {
8095 int n = find_applet_by_name(argv_expanded[0]);
8096 if (n >= 0 && APPLET_IS_NOFORK(n)) {
8097 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, &squirrel, argv_expanded);
8099 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
8100 argv_expanded[0], argv_expanded[1]);
8102 * Note: signals (^C) can't interrupt here.
8103 * We remember them and they will be acted upon
8104 * after applet returns.
8105 * This makes applets which can run for a long time
8106 * and/or wait for user input ineligible for NOFORK:
8107 * for example, "yes" or "rm" (rm -i waits for input).
8109 rcode = run_nofork_applet(n, argv_expanded);
8111 goto clean_up_and_ret;
8114 /* It is neither builtin nor applet. We must fork. */
8118 /* NB: argv_expanded may already be created, and that
8119 * might include `cmd` runs! Do not rerun it! We *must*
8120 * use argv_expanded if it's non-NULL */
8122 /* Going to fork a child per each pipe member */
8127 while (cmd_no < pi->num_cmds) {
8128 struct fd_pair pipefds;
8130 volatile nommu_save_t nommu_save;
8131 nommu_save.new_env = NULL;
8132 nommu_save.old_vars = NULL;
8133 nommu_save.argv = NULL;
8134 nommu_save.argv_from_re_execing = NULL;
8136 command = &pi->cmds[cmd_no];
8138 if (command->argv) {
8139 debug_printf_exec(": pipe member '%s' '%s'...\n",
8140 command->argv[0], command->argv[1]);
8142 debug_printf_exec(": pipe member with no argv\n");
8145 /* pipes are inserted between pairs of commands */
8148 if (cmd_no < pi->num_cmds)
8149 xpiped_pair(pipefds);
8151 command->pid = BB_MMU ? fork() : vfork();
8152 if (!command->pid) { /* child */
8154 disable_restore_tty_pgrp_on_exit();
8155 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
8157 /* Every child adds itself to new process group
8158 * with pgid == pid_of_first_child_in_pipe */
8159 if (G.run_list_level == 1 && G_interactive_fd) {
8162 if (pgrp < 0) /* true for 1st process only */
8164 if (setpgid(0, pgrp) == 0
8165 && pi->followup != PIPE_BG
8166 && G_saved_tty_pgrp /* we have ctty */
8168 /* We do it in *every* child, not just first,
8170 tcsetpgrp(G_interactive_fd, pgrp);
8174 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
8175 /* 1st cmd in backgrounded pipe
8176 * should have its stdin /dev/null'ed */
8178 if (open(bb_dev_null, O_RDONLY))
8179 xopen("/", O_RDONLY);
8181 xmove_fd(next_infd, 0);
8183 xmove_fd(pipefds.wr, 1);
8186 /* Like bash, explicit redirects override pipes,
8187 * and the pipe fd (fd#1) is available for dup'ing:
8188 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
8189 * of cmd1 goes into pipe.
8191 if (setup_redirects(command, NULL)) {
8192 /* Happens when redir file can't be opened:
8193 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
8195 * hush: can't open '/qwe/rty': No such file or directory
8197 * (echo BAR is not executed, it hits _exit(1) below)
8202 /* Stores to nommu_save list of env vars putenv'ed
8203 * (NOMMU, on MMU we don't need that) */
8204 /* cast away volatility... */
8205 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
8206 /* pseudo_exec() does not return */
8209 /* parent or error */
8210 #if ENABLE_HUSH_FAST
8212 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
8214 enable_restore_tty_pgrp_on_exit();
8216 /* Clean up after vforked child */
8217 free(nommu_save.argv);
8218 free(nommu_save.argv_from_re_execing);
8219 unset_vars(nommu_save.new_env);
8220 add_vars(nommu_save.old_vars);
8222 free(argv_expanded);
8223 argv_expanded = NULL;
8224 if (command->pid < 0) { /* [v]fork failed */
8225 /* Clearly indicate, was it fork or vfork */
8226 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
8230 /* Second and next children need to know pid of first one */
8232 pi->pgrp = command->pid;
8238 if (cmd_no < pi->num_cmds)
8240 /* Pass read (output) pipe end to next iteration */
8241 next_infd = pipefds.rd;
8244 if (!pi->alive_cmds) {
8246 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
8251 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
8255 /* NB: called by pseudo_exec, and therefore must not modify any
8256 * global data until exec/_exit (we can be a child after vfork!) */
8257 static int run_list(struct pipe *pi)
8259 #if ENABLE_HUSH_CASE
8260 char *case_word = NULL;
8262 #if ENABLE_HUSH_LOOPS
8263 struct pipe *loop_top = NULL;
8264 char **for_lcur = NULL;
8265 char **for_list = NULL;
8267 smallint last_followup;
8269 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
8270 smalluint cond_code = 0;
8272 enum { cond_code = 0 };
8275 smallint rword; /* RES_foo */
8276 smallint last_rword; /* ditto */
8279 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
8282 #if ENABLE_HUSH_LOOPS
8283 /* Check syntax for "for" */
8286 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
8287 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
8289 /* current word is FOR or IN (BOLD in comments below) */
8290 if (cpipe->next == NULL) {
8291 syntax_error("malformed for");
8293 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8296 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
8297 if (cpipe->next->res_word == RES_DO)
8299 /* next word is not "do". It must be "in" then ("FOR v in ...") */
8300 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
8301 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
8303 syntax_error("malformed for");
8305 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
8312 /* Past this point, all code paths should jump to ret: label
8313 * in order to return, no direct "return" statements please.
8314 * This helps to ensure that no memory is leaked. */
8322 last_rword = RES_XXXX;
8324 last_followup = PIPE_SEQ;
8325 rcode = G.last_exitcode;
8327 /* Go through list of pipes, (maybe) executing them. */
8328 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
8330 int sv_errexit_depth;
8334 if (G_flag_return_in_progress == 1)
8337 IF_HAS_KEYWORDS(rword = pi->res_word;)
8338 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
8339 rword, cond_code, last_rword);
8341 sv_errexit_depth = G.errexit_depth;
8342 if (IF_HAS_KEYWORDS(rword == RES_IF || rword == RES_ELIF ||)
8343 pi->followup != PIPE_SEQ
8347 #if ENABLE_HUSH_LOOPS
8348 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
8349 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
8351 /* start of a loop: remember where loop starts */
8356 /* Still in the same "if...", "then..." or "do..." branch? */
8357 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
8358 if ((rcode == 0 && last_followup == PIPE_OR)
8359 || (rcode != 0 && last_followup == PIPE_AND)
8361 /* It is "<true> || CMD" or "<false> && CMD"
8362 * and we should not execute CMD */
8363 debug_printf_exec("skipped cmd because of || or &&\n");
8364 last_followup = pi->followup;
8365 goto dont_check_jobs_but_continue;
8368 last_followup = pi->followup;
8369 IF_HAS_KEYWORDS(last_rword = rword;)
8372 if (rword == RES_THEN) {
8373 /* if false; then ... fi has exitcode 0! */
8374 G.last_exitcode = rcode = EXIT_SUCCESS;
8375 /* "if <false> THEN cmd": skip cmd */
8379 if (rword == RES_ELSE || rword == RES_ELIF) {
8380 /* "if <true> then ... ELSE/ELIF cmd":
8381 * skip cmd and all following ones */
8386 #if ENABLE_HUSH_LOOPS
8387 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
8389 /* first loop through for */
8391 static const char encoded_dollar_at[] ALIGN1 = {
8392 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
8393 }; /* encoded representation of "$@" */
8394 static const char *const encoded_dollar_at_argv[] = {
8395 encoded_dollar_at, NULL
8396 }; /* argv list with one element: "$@" */
8399 vals = (char**)encoded_dollar_at_argv;
8400 if (pi->next->res_word == RES_IN) {
8401 /* if no variable values after "in" we skip "for" */
8402 if (!pi->next->cmds[0].argv) {
8403 G.last_exitcode = rcode = EXIT_SUCCESS;
8404 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
8407 vals = pi->next->cmds[0].argv;
8408 } /* else: "for var; do..." -> assume "$@" list */
8409 /* create list of variable values */
8410 debug_print_strings("for_list made from", vals);
8411 for_list = expand_strvec_to_strvec(vals);
8412 for_lcur = for_list;
8413 debug_print_strings("for_list", for_list);
8416 /* "for" loop is over, clean up */
8422 /* Insert next value from for_lcur */
8423 /* note: *for_lcur already has quotes removed, $var expanded, etc */
8424 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*flag:*/ 0);
8427 if (rword == RES_IN) {
8428 continue; /* "for v IN list;..." - "in" has no cmds anyway */
8430 if (rword == RES_DONE) {
8431 continue; /* "done" has no cmds too */
8434 #if ENABLE_HUSH_CASE
8435 if (rword == RES_CASE) {
8436 debug_printf_exec("CASE cond_code:%d\n", cond_code);
8437 case_word = expand_strvec_to_string(pi->cmds->argv);
8438 unbackslash(case_word);
8441 if (rword == RES_MATCH) {
8444 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
8445 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
8447 /* all prev words didn't match, does this one match? */
8448 argv = pi->cmds->argv;
8450 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 0);
8451 /* TODO: which FNM_xxx flags to use? */
8452 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
8453 debug_printf_exec("fnmatch(pattern:'%s',str:'%s'):%d\n", pattern, case_word, cond_code);
8455 if (cond_code == 0) { /* match! we will execute this branch */
8457 case_word = NULL; /* make future "word)" stop */
8464 if (rword == RES_CASE_BODY) { /* inside of a case branch */
8465 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
8467 continue; /* not matched yet, skip this pipe */
8469 if (rword == RES_ESAC) {
8470 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
8472 /* "case" did not match anything: still set $? (to 0) */
8473 G.last_exitcode = rcode = EXIT_SUCCESS;
8477 /* Just pressing <enter> in shell should check for jobs.
8478 * OTOH, in non-interactive shell this is useless
8479 * and only leads to extra job checks */
8480 if (pi->num_cmds == 0) {
8481 if (G_interactive_fd)
8482 goto check_jobs_and_continue;
8486 /* After analyzing all keywords and conditions, we decided
8487 * to execute this pipe. NB: have to do checkjobs(NULL)
8488 * after run_pipe to collect any background children,
8489 * even if list execution is to be stopped. */
8490 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
8491 #if ENABLE_HUSH_LOOPS
8492 G.flag_break_continue = 0;
8494 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
8496 /* We ran a builtin, function, or group.
8497 * rcode is already known
8498 * and we don't need to wait for anything. */
8499 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
8500 G.last_exitcode = rcode;
8501 check_and_run_traps();
8502 #if ENABLE_HUSH_LOOPS
8503 /* Was it "break" or "continue"? */
8504 if (G.flag_break_continue) {
8505 smallint fbc = G.flag_break_continue;
8506 /* We might fall into outer *loop*,
8507 * don't want to break it too */
8509 G.depth_break_continue--;
8510 if (G.depth_break_continue == 0)
8511 G.flag_break_continue = 0;
8512 /* else: e.g. "continue 2" should *break* once, *then* continue */
8513 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
8514 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
8515 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8518 /* "continue": simulate end of loop */
8523 if (G_flag_return_in_progress == 1) {
8524 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8527 } else if (pi->followup == PIPE_BG) {
8528 /* What does bash do with attempts to background builtins? */
8529 /* even bash 3.2 doesn't do that well with nested bg:
8530 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8531 * I'm NOT treating inner &'s as jobs */
8533 if (G.run_list_level == 1)
8534 insert_job_into_table(pi);
8536 /* Last command's pid goes to $! */
8537 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8538 G.last_bg_pid_exitcode = 0;
8539 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8540 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash say 0 */
8541 rcode = EXIT_SUCCESS;
8545 if (G.run_list_level == 1 && G_interactive_fd) {
8546 /* Waits for completion, then fg's main shell */
8547 rcode = checkjobs_and_fg_shell(pi);
8548 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8552 /* This one just waits for completion */
8553 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8554 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8556 G.last_exitcode = rcode;
8557 check_and_run_traps();
8560 /* Handle "set -e" */
8561 if (rcode != 0 && G.o_opt[OPT_O_ERREXIT]) {
8562 debug_printf_exec("ERREXIT:1 errexit_depth:%d\n", G.errexit_depth);
8563 if (G.errexit_depth == 0)
8566 G.errexit_depth = sv_errexit_depth;
8568 /* Analyze how result affects subsequent commands */
8570 if (rword == RES_IF || rword == RES_ELIF)
8573 check_jobs_and_continue:
8574 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8575 dont_check_jobs_but_continue: ;
8576 #if ENABLE_HUSH_LOOPS
8577 /* Beware of "while false; true; do ..."! */
8579 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8580 /* check for RES_DONE is needed for "while ...; do \n done" case */
8582 if (rword == RES_WHILE) {
8584 /* "while false; do...done" - exitcode 0 */
8585 G.last_exitcode = rcode = EXIT_SUCCESS;
8586 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8590 if (rword == RES_UNTIL) {
8592 debug_printf_exec(": until expr is true: breaking\n");
8603 #if ENABLE_HUSH_LOOPS
8608 #if ENABLE_HUSH_CASE
8612 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8616 /* Select which version we will use */
8617 static int run_and_free_list(struct pipe *pi)
8620 debug_printf_exec("run_and_free_list entered\n");
8621 if (!G.o_opt[OPT_O_NOEXEC]) {
8622 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8623 rcode = run_list(pi);
8625 /* free_pipe_list has the side effect of clearing memory.
8626 * In the long run that function can be merged with run_list,
8627 * but doing that now would hobble the debugging effort. */
8629 debug_printf_exec("run_and_free_list return %d\n", rcode);
8634 static void install_sighandlers(unsigned mask)
8636 sighandler_t old_handler;
8638 while ((mask >>= 1) != 0) {
8642 old_handler = install_sighandler(sig, pick_sighandler(sig));
8643 /* POSIX allows shell to re-enable SIGCHLD
8644 * even if it was SIG_IGN on entry.
8645 * Therefore we skip IGN check for it:
8649 if (old_handler == SIG_IGN) {
8650 /* oops... restore back to IGN, and record this fact */
8651 install_sighandler(sig, old_handler);
8652 #if ENABLE_HUSH_TRAP
8654 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8656 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8662 /* Called a few times only (or even once if "sh -c") */
8663 static void install_special_sighandlers(void)
8667 /* Which signals are shell-special? */
8668 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8669 if (G_interactive_fd) {
8670 mask |= SPECIAL_INTERACTIVE_SIGS;
8671 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8672 mask |= SPECIAL_JOBSTOP_SIGS;
8674 /* Careful, do not re-install handlers we already installed */
8675 if (G.special_sig_mask != mask) {
8676 unsigned diff = mask & ~G.special_sig_mask;
8677 G.special_sig_mask = mask;
8678 install_sighandlers(diff);
8684 /* Set handlers to restore tty pgrp and exit */
8685 static void install_fatal_sighandlers(void)
8689 /* We will restore tty pgrp on these signals */
8691 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8692 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8693 + (1 << SIGBUS ) * HUSH_DEBUG
8694 + (1 << SIGSEGV) * HUSH_DEBUG
8695 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8697 /* bash 3.2 seems to handle these just like 'fatal' ones */
8700 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8701 * if we aren't interactive... but in this case
8702 * we never want to restore pgrp on exit, and this fn is not called
8704 /*+ (1 << SIGHUP )*/
8705 /*+ (1 << SIGTERM)*/
8706 /*+ (1 << SIGINT )*/
8708 G_fatal_sig_mask = mask;
8710 install_sighandlers(mask);
8714 static int set_mode(int state, char mode, const char *o_opt)
8719 G.o_opt[OPT_O_NOEXEC] = state;
8722 IF_HUSH_MODE_X(G_x_mode = state;)
8726 /* "set -+o" without parameter.
8727 * in bash, set -o produces this output:
8731 * We always use the second form.
8733 const char *p = o_opt_strings;
8736 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8742 idx = index_in_strings(o_opt_strings, o_opt);
8744 G.o_opt[idx] = state;
8748 G.o_opt[OPT_O_ERREXIT] = state;
8751 return EXIT_FAILURE;
8753 return EXIT_SUCCESS;
8756 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8757 int hush_main(int argc, char **argv)
8760 OPT_login = (1 << 0),
8764 unsigned builtin_argc;
8766 struct variable *cur_var;
8767 struct variable *shell_ver;
8770 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8771 G.last_exitcode = EXIT_SUCCESS;
8773 #if ENABLE_HUSH_FAST
8774 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8777 G.argv0_for_re_execing = argv[0];
8779 /* Deal with HUSH_VERSION */
8780 shell_ver = xzalloc(sizeof(*shell_ver));
8781 shell_ver->flg_export = 1;
8782 shell_ver->flg_read_only = 1;
8783 /* Code which handles ${var<op>...} needs writable values for all variables,
8784 * therefore we xstrdup: */
8785 shell_ver->varstr = xstrdup(hush_version_str);
8786 /* Create shell local variables from the values
8787 * currently living in the environment */
8788 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8789 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8790 G.top_var = shell_ver;
8791 cur_var = G.top_var;
8794 char *value = strchr(*e, '=');
8795 if (value) { /* paranoia */
8796 cur_var->next = xzalloc(sizeof(*cur_var));
8797 cur_var = cur_var->next;
8798 cur_var->varstr = *e;
8799 cur_var->max_len = strlen(*e);
8800 cur_var->flg_export = 1;
8804 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8805 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8806 putenv(shell_ver->varstr);
8809 set_pwd_var(SETFLAG_EXPORT);
8811 #if BASH_HOSTNAME_VAR
8812 /* Set (but not export) HOSTNAME unless already set */
8813 if (!get_local_var_value("HOSTNAME")) {
8816 set_local_var_from_halves("HOSTNAME", uts.nodename);
8818 /* bash also exports SHLVL and _,
8819 * and sets (but doesn't export) the following variables:
8821 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8822 * BASH_VERSION='3.2.0(1)-release'
8824 * MACHTYPE=i386-pc-linux-gnu
8826 * PPID=<NNNNN> - we also do it elsewhere
8837 * PIPESTATUS=([0]="0")
8838 * HISTFILE=/<xxx>/.bash_history
8842 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8844 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8855 #if ENABLE_FEATURE_EDITING
8856 G.line_input_state = new_line_input_t(FOR_SHELL);
8859 /* Initialize some more globals to non-zero values */
8860 cmdedit_update_prompt();
8862 die_func = restore_ttypgrp_and__exit;
8864 /* Shell is non-interactive at first. We need to call
8865 * install_special_sighandlers() if we are going to execute "sh <script>",
8866 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8867 * If we later decide that we are interactive, we run install_special_sighandlers()
8868 * in order to intercept (more) signals.
8872 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8873 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8876 opt = getopt(argc, argv, "+c:exinsl"
8879 # if ENABLE_HUSH_FUNCTIONS
8889 * sh ... -c 'script'
8890 * sh ... -c 'script' ARG0 [ARG1...]
8891 * On NOMMU, if builtin_argc != 0,
8892 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8893 * "" needs to be replaced with NULL
8894 * and BARGV vector fed to builtin function.
8895 * Note: the form without ARG0 never happens:
8896 * sh ... -c 'builtin' BARGV... ""
8899 G.root_pid = getpid();
8900 G.root_ppid = getppid();
8902 G.global_argv = argv + optind;
8903 G.global_argc = argc - optind;
8905 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8906 const struct built_in_command *x;
8908 install_special_sighandlers();
8909 x = find_builtin(optarg);
8910 if (x) { /* paranoia */
8911 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8912 G.global_argv += builtin_argc;
8913 G.global_argv[-1] = NULL; /* replace "" */
8915 G.last_exitcode = x->b_function(argv + optind - 1);
8919 if (!G.global_argv[0]) {
8920 /* -c 'script' (no params): prevent empty $0 */
8921 G.global_argv--; /* points to argv[i] of 'script' */
8922 G.global_argv[0] = argv[0];
8924 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8925 install_special_sighandlers();
8926 parse_and_run_string(optarg);
8929 /* Well, we cannot just declare interactiveness,
8930 * we have to have some stuff (ctty, etc) */
8931 /* G_interactive_fd++; */
8934 /* "-s" means "read from stdin", but this is how we always
8935 * operate, so simply do nothing here. */
8941 case '<': /* "big heredoc" support */
8942 full_write1_str(optarg);
8945 unsigned long long empty_trap_mask;
8947 G.root_pid = bb_strtou(optarg, &optarg, 16);
8949 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8951 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8953 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8955 builtin_argc = bb_strtou(optarg, &optarg, 16);
8957 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8958 if (empty_trap_mask != 0) {
8959 IF_HUSH_TRAP(int sig;)
8960 install_special_sighandlers();
8961 # if ENABLE_HUSH_TRAP
8962 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
8963 for (sig = 1; sig < NSIG; sig++) {
8964 if (empty_trap_mask & (1LL << sig)) {
8965 G_traps[sig] = xzalloc(1); /* == xstrdup(""); */
8966 install_sighandler(sig, SIG_IGN);
8971 # if ENABLE_HUSH_LOOPS
8973 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8979 set_local_var(xstrdup(optarg), opt == 'R' ? SETFLAG_MAKE_RO : 0);
8981 # if ENABLE_HUSH_FUNCTIONS
8983 struct function *funcp = new_function(optarg);
8984 /* funcp->name is already set to optarg */
8985 /* funcp->body is set to NULL. It's a special case. */
8986 funcp->body_as_string = argv[optind];
8995 if (set_mode(1, opt, NULL) == 0) /* no error */
8999 fprintf(stderr, "Usage: sh [FILE]...\n"
9000 " or: sh -c command [args]...\n\n");
9006 } /* option parsing loop */
9008 /* Skip options. Try "hush -l": $1 should not be "-l"! */
9009 G.global_argc = argc - (optind - 1);
9010 G.global_argv = argv + (optind - 1);
9011 G.global_argv[0] = argv[0];
9014 G.root_pid = getpid();
9015 G.root_ppid = getppid();
9018 /* If we are login shell... */
9019 if (flags & OPT_login) {
9021 debug_printf("sourcing /etc/profile\n");
9022 input = fopen_for_read("/etc/profile");
9023 if (input != NULL) {
9024 remember_FILE(input);
9025 install_special_sighandlers();
9026 parse_and_run_file(input);
9027 fclose_and_forget(input);
9029 /* bash: after sourcing /etc/profile,
9030 * tries to source (in the given order):
9031 * ~/.bash_profile, ~/.bash_login, ~/.profile,
9032 * stopping on first found. --noprofile turns this off.
9033 * bash also sources ~/.bash_logout on exit.
9034 * If called as sh, skips .bash_XXX files.
9038 if (G.global_argv[1]) {
9041 * "bash <script>" (which is never interactive (unless -i?))
9042 * sources $BASH_ENV here (without scanning $PATH).
9043 * If called as sh, does the same but with $ENV.
9044 * Also NB, per POSIX, $ENV should undergo parameter expansion.
9048 debug_printf("running script '%s'\n", G.global_argv[0]);
9049 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
9050 input = xfopen_for_read(G.global_argv[0]);
9051 xfunc_error_retval = 1;
9052 remember_FILE(input);
9053 install_special_sighandlers();
9054 parse_and_run_file(input);
9055 #if ENABLE_FEATURE_CLEAN_UP
9056 fclose_and_forget(input);
9061 /* Up to here, shell was non-interactive. Now it may become one.
9062 * NB: don't forget to (re)run install_special_sighandlers() as needed.
9065 /* A shell is interactive if the '-i' flag was given,
9066 * or if all of the following conditions are met:
9068 * no arguments remaining or the -s flag given
9069 * standard input is a terminal
9070 * standard output is a terminal
9071 * Refer to Posix.2, the description of the 'sh' utility.
9074 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9075 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
9076 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
9077 if (G_saved_tty_pgrp < 0)
9078 G_saved_tty_pgrp = 0;
9080 /* try to dup stdin to high fd#, >= 255 */
9081 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9082 if (G_interactive_fd < 0) {
9083 /* try to dup to any fd */
9084 G_interactive_fd = dup(STDIN_FILENO);
9085 if (G_interactive_fd < 0) {
9087 G_interactive_fd = 0;
9088 G_saved_tty_pgrp = 0;
9091 // TODO: track & disallow any attempts of user
9092 // to (inadvertently) close/redirect G_interactive_fd
9094 debug_printf("interactive_fd:%d\n", G_interactive_fd);
9095 if (G_interactive_fd) {
9096 close_on_exec_on(G_interactive_fd);
9098 if (G_saved_tty_pgrp) {
9099 /* If we were run as 'hush &', sleep until we are
9100 * in the foreground (tty pgrp == our pgrp).
9101 * If we get started under a job aware app (like bash),
9102 * make sure we are now in charge so we don't fight over
9103 * who gets the foreground */
9105 pid_t shell_pgrp = getpgrp();
9106 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
9107 if (G_saved_tty_pgrp == shell_pgrp)
9109 /* send TTIN to ourself (should stop us) */
9110 kill(- shell_pgrp, SIGTTIN);
9114 /* Install more signal handlers */
9115 install_special_sighandlers();
9117 if (G_saved_tty_pgrp) {
9118 /* Set other signals to restore saved_tty_pgrp */
9119 install_fatal_sighandlers();
9120 /* Put ourselves in our own process group
9121 * (bash, too, does this only if ctty is available) */
9122 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
9123 /* Grab control of the terminal */
9124 tcsetpgrp(G_interactive_fd, getpid());
9126 enable_restore_tty_pgrp_on_exit();
9128 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
9130 const char *hp = get_local_var_value("HISTFILE");
9132 hp = get_local_var_value("HOME");
9134 hp = concat_path_file(hp, ".hush_history");
9139 G.line_input_state->hist_file = hp;
9140 //set_local_var(xasprintf("HISTFILE=%s", ...));
9142 # if ENABLE_FEATURE_SH_HISTFILESIZE
9143 hp = get_local_var_value("HISTFILESIZE");
9144 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
9149 install_special_sighandlers();
9151 #elif ENABLE_HUSH_INTERACTIVE
9152 /* No job control compiled in, only prompt/line editing */
9153 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
9154 G_interactive_fd = fcntl_F_DUPFD(STDIN_FILENO, 254);
9155 if (G_interactive_fd < 0) {
9156 /* try to dup to any fd */
9157 G_interactive_fd = dup(STDIN_FILENO);
9158 if (G_interactive_fd < 0)
9160 G_interactive_fd = 0;
9163 if (G_interactive_fd) {
9164 close_on_exec_on(G_interactive_fd);
9166 install_special_sighandlers();
9168 /* We have interactiveness code disabled */
9169 install_special_sighandlers();
9172 * if interactive but not a login shell, sources ~/.bashrc
9173 * (--norc turns this off, --rcfile <file> overrides)
9176 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
9177 /* note: ash and hush share this string */
9178 printf("\n\n%s %s\n"
9179 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
9182 "hush - the humble shell"
9186 parse_and_run_file(stdin);
9189 hush_exit(G.last_exitcode);
9196 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
9201 #if ENABLE_HUSH_TEST || ENABLE_HUSH_ECHO || ENABLE_HUSH_PRINTF || ENABLE_HUSH_KILL
9202 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
9204 int argc = string_array_len(argv);
9205 return applet_main_func(argc, argv);
9208 #if ENABLE_HUSH_TEST || BASH_TEST2
9209 static int FAST_FUNC builtin_test(char **argv)
9211 return run_applet_main(argv, test_main);
9214 #if ENABLE_HUSH_ECHO
9215 static int FAST_FUNC builtin_echo(char **argv)
9217 return run_applet_main(argv, echo_main);
9220 #if ENABLE_HUSH_PRINTF
9221 static int FAST_FUNC builtin_printf(char **argv)
9223 return run_applet_main(argv, printf_main);
9227 #if ENABLE_HUSH_HELP
9228 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9230 const struct built_in_command *x;
9233 "Built-in commands:\n"
9234 "------------------\n");
9235 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9237 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9239 return EXIT_SUCCESS;
9243 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9244 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9246 show_history(G.line_input_state);
9247 return EXIT_SUCCESS;
9251 static char **skip_dash_dash(char **argv)
9254 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
9259 static int FAST_FUNC builtin_cd(char **argv)
9263 argv = skip_dash_dash(argv);
9265 if (newdir == NULL) {
9266 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
9267 * bash says "bash: cd: HOME not set" and does nothing
9270 const char *home = get_local_var_value("HOME");
9271 newdir = home ? home : "/";
9273 if (chdir(newdir)) {
9274 /* Mimic bash message exactly */
9275 bb_perror_msg("cd: %s", newdir);
9276 return EXIT_FAILURE;
9278 /* Read current dir (get_cwd(1) is inside) and set PWD.
9279 * Note: do not enforce exporting. If PWD was unset or unexported,
9280 * set it again, but do not export. bash does the same.
9282 set_pwd_var(/*flag:*/ 0);
9283 return EXIT_SUCCESS;
9286 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9289 return EXIT_SUCCESS;
9292 static int FAST_FUNC builtin_eval(char **argv)
9294 int rcode = EXIT_SUCCESS;
9296 argv = skip_dash_dash(argv);
9298 char *str = expand_strvec_to_string(argv);
9300 * eval "echo Hi; done" ("done" is syntax error):
9301 * "echo Hi" will not execute too.
9303 parse_and_run_string(str);
9305 rcode = G.last_exitcode;
9310 static int FAST_FUNC builtin_exec(char **argv)
9312 argv = skip_dash_dash(argv);
9313 if (argv[0] == NULL)
9314 return EXIT_SUCCESS; /* bash does this */
9316 /* Careful: we can end up here after [v]fork. Do not restore
9317 * tty pgrp then, only top-level shell process does that */
9318 if (G_saved_tty_pgrp && getpid() == G.root_pid)
9319 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
9321 /* Saved-redirect fds, script fds and G_interactive_fd are still
9322 * open here. However, they are all CLOEXEC, and execv below
9323 * closes them. Try interactive "exec ls -l /proc/self/fd",
9324 * it should show no extra open fds in the "ls" process.
9325 * If we'd try to run builtins/NOEXECs, this would need improving.
9327 //close_saved_fds_and_FILE_fds();
9329 /* TODO: if exec fails, bash does NOT exit! We do.
9330 * We'll need to undo trap cleanup (it's inside execvp_or_die)
9331 * and tcsetpgrp, and this is inherently racy.
9333 execvp_or_die(argv);
9336 static int FAST_FUNC builtin_exit(char **argv)
9338 debug_printf_exec("%s()\n", __func__);
9340 /* interactive bash:
9341 * # trap "echo EEE" EXIT
9344 * There are stopped jobs.
9345 * (if there are _stopped_ jobs, running ones don't count)
9348 * EEE (then bash exits)
9350 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
9353 /* note: EXIT trap is run by hush_exit */
9354 argv = skip_dash_dash(argv);
9355 if (argv[0] == NULL)
9356 hush_exit(G.last_exitcode);
9357 /* mimic bash: exit 123abc == exit 255 + error msg */
9358 xfunc_error_retval = 255;
9359 /* bash: exit -2 == exit 254, no error msg */
9360 hush_exit(xatoi(argv[0]) & 0xff);
9363 #if ENABLE_HUSH_TYPE
9364 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9365 static int FAST_FUNC builtin_type(char **argv)
9367 int ret = EXIT_SUCCESS;
9373 if (0) {} /* make conditional compile easier below */
9374 /*else if (find_alias(*argv))
9375 type = "an alias";*/
9376 #if ENABLE_HUSH_FUNCTIONS
9377 else if (find_function(*argv))
9378 type = "a function";
9380 else if (find_builtin(*argv))
9381 type = "a shell builtin";
9382 else if ((path = find_in_path(*argv)) != NULL)
9385 bb_error_msg("type: %s: not found", *argv);
9390 printf("%s is %s\n", *argv, type);
9398 #if ENABLE_HUSH_READ
9399 /* Interruptibility of read builtin in bash
9400 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9402 * Empty trap makes read ignore corresponding signal, for any signal.
9405 * - terminates non-interactive shell;
9406 * - interrupts read in interactive shell;
9407 * if it has non-empty trap:
9408 * - executes trap and returns to command prompt in interactive shell;
9409 * - executes trap and returns to read in non-interactive shell;
9411 * - is ignored (does not interrupt) read in interactive shell;
9412 * - terminates non-interactive shell;
9413 * if it has non-empty trap:
9414 * - executes trap and returns to read;
9416 * - terminates shell (regardless of interactivity);
9417 * if it has non-empty trap:
9418 * - executes trap and returns to read;
9419 * SIGCHLD from children:
9420 * - does not interrupt read regardless of interactivity:
9421 * try: sleep 1 & read x; echo $x
9423 static int FAST_FUNC builtin_read(char **argv)
9433 /* "!": do not abort on errors.
9434 * Option string must start with "sr" to match BUILTIN_READ_xxx
9436 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9437 if (read_flags == (uint32_t)-1)
9438 return EXIT_FAILURE;
9440 ifs = get_local_var_value("IFS"); /* can be NULL */
9443 r = shell_builtin_read(set_local_var_from_halves,
9453 if ((uintptr_t)r == 1 && errno == EINTR) {
9454 unsigned sig = check_and_run_traps();
9459 if ((uintptr_t)r > 1) {
9460 bb_error_msg("%s", r);
9461 r = (char*)(uintptr_t)1;
9464 return (uintptr_t)r;
9468 #if ENABLE_HUSH_UMASK
9469 static int FAST_FUNC builtin_umask(char **argv)
9476 argv = skip_dash_dash(argv);
9478 mode_t old_mask = mask;
9480 /* numeric umasks are taken as-is */
9481 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9482 if (!isdigit(argv[0][0]))
9484 mask = bb_parse_mode(argv[0], mask);
9485 if (!isdigit(argv[0][0]))
9487 if ((unsigned)mask > 0777) {
9490 * bash: umask: 'q': invalid symbolic mode operator
9491 * bash: umask: 999: octal number out of range
9493 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9498 printf("%04o\n", (unsigned) mask);
9499 /* fall through and restore mask which we set to 0 */
9503 return !rc; /* rc != 0 - success */
9507 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_TRAP
9508 static void print_escaped(const char *s)
9513 const char *p = strchrnul(s, '\'');
9514 /* print 'xxxx', possibly just '' */
9515 printf("'%.*s'", (int)(p - s), s);
9520 /* s points to '; print "'''...'''" */
9522 do putchar('\''); while (*++s == '\'');
9528 #if ENABLE_HUSH_EXPORT || ENABLE_HUSH_LOCAL || ENABLE_HUSH_READONLY
9529 static int helper_export_local(char **argv, unsigned flags)
9533 char *name_end = strchrnul(name, '=');
9535 /* So far we do not check that name is valid (TODO?) */
9537 if (*name_end == '\0') {
9538 struct variable *var, **vpp;
9540 vpp = get_ptr_to_local_var(name, name_end - name);
9541 var = vpp ? *vpp : NULL;
9543 if (flags & SETFLAG_UNEXPORT) {
9544 /* export -n NAME (without =VALUE) */
9546 var->flg_export = 0;
9547 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
9549 } /* else: export -n NOT_EXISTING_VAR: no-op */
9552 if (flags & SETFLAG_EXPORT) {
9553 /* export NAME (without =VALUE) */
9555 var->flg_export = 1;
9556 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
9557 putenv(var->varstr);
9561 if (flags & SETFLAG_MAKE_RO) {
9562 /* readonly NAME (without =VALUE) */
9564 var->flg_read_only = 1;
9568 # if ENABLE_HUSH_LOCAL
9569 /* Is this "local" bltin? */
9570 if (!(flags & (SETFLAG_EXPORT|SETFLAG_UNEXPORT|SETFLAG_MAKE_RO))) {
9571 unsigned lvl = flags >> SETFLAG_LOCAL_SHIFT;
9572 if (var && var->func_nest_level == lvl) {
9573 /* "local x=abc; ...; local x" - ignore second local decl */
9578 /* Exporting non-existing variable.
9579 * bash does not put it in environment,
9580 * but remembers that it is exported,
9581 * and does put it in env when it is set later.
9582 * We just set it to "" and export.
9584 /* Or, it's "local NAME" (without =VALUE).
9585 * bash sets the value to "".
9587 /* Or, it's "readonly NAME" (without =VALUE).
9588 * bash remembers NAME and disallows its creation
9591 name = xasprintf("%s=", name);
9593 /* (Un)exporting/making local NAME=VALUE */
9594 name = xstrdup(name);
9596 if (set_local_var(name, flags))
9597 return EXIT_FAILURE;
9599 return EXIT_SUCCESS;
9603 #if ENABLE_HUSH_EXPORT
9604 static int FAST_FUNC builtin_export(char **argv)
9606 unsigned opt_unexport;
9608 #if ENABLE_HUSH_EXPORT_N
9609 /* "!": do not abort on errors */
9610 opt_unexport = getopt32(argv, "!n");
9611 if (opt_unexport == (uint32_t)-1)
9612 return EXIT_FAILURE;
9619 if (argv[0] == NULL) {
9626 /* ash emits: export VAR='VAL'
9627 * bash: declare -x VAR="VAL"
9628 * we follow ash example */
9629 const char *s = *e++;
9630 const char *p = strchr(s, '=');
9632 if (!p) /* wtf? take next variable */
9635 printf("export %.*s", (int)(p - s) + 1, s);
9636 print_escaped(p + 1);
9640 /*fflush_all(); - done after each builtin anyway */
9642 return EXIT_SUCCESS;
9645 return helper_export_local(argv, opt_unexport ? SETFLAG_UNEXPORT : SETFLAG_EXPORT);
9649 #if ENABLE_HUSH_LOCAL
9650 static int FAST_FUNC builtin_local(char **argv)
9652 if (G.func_nest_level == 0) {
9653 bb_error_msg("%s: not in a function", argv[0]);
9654 return EXIT_FAILURE; /* bash compat */
9657 return helper_export_local(argv, G.func_nest_level << SETFLAG_LOCAL_SHIFT);
9661 #if ENABLE_HUSH_READONLY
9662 static int FAST_FUNC builtin_readonly(char **argv)
9665 if (*argv == NULL) {
9666 /* bash: readonly [-p]: list all readonly VARs
9667 * (-p has no effect in bash)
9670 for (e = G.top_var; e; e = e->next) {
9671 if (e->flg_read_only) {
9672 //TODO: quote value: readonly VAR='VAL'
9673 printf("readonly %s\n", e->varstr);
9676 return EXIT_SUCCESS;
9678 return helper_export_local(argv, SETFLAG_MAKE_RO);
9682 #if ENABLE_HUSH_UNSET
9683 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9684 static int FAST_FUNC builtin_unset(char **argv)
9689 /* "!": do not abort on errors */
9690 /* "+": stop at 1st non-option */
9691 opts = getopt32(argv, "!+vf");
9692 if (opts == (unsigned)-1)
9693 return EXIT_FAILURE;
9695 bb_error_msg("unset: -v and -f are exclusive");
9696 return EXIT_FAILURE;
9702 if (!(opts & 2)) { /* not -f */
9703 if (unset_local_var(*argv)) {
9704 /* unset <nonexistent_var> doesn't fail.
9705 * Error is when one tries to unset RO var.
9706 * Message was printed by unset_local_var. */
9710 # if ENABLE_HUSH_FUNCTIONS
9722 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
9723 * built-in 'set' handler
9725 * set [-abCefhmnuvx] [-o option] [argument...]
9726 * set [+abCefhmnuvx] [+o option] [argument...]
9727 * set -- [argument...]
9730 * Implementations shall support the options in both their hyphen and
9731 * plus-sign forms. These options can also be specified as options to sh.
9733 * Write out all variables and their values: set
9734 * Set $1, $2, and $3 and set "$#" to 3: set c a b
9735 * Turn on the -x and -v options: set -xv
9736 * Unset all positional parameters: set --
9737 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
9738 * Set the positional parameters to the expansion of x, even if x expands
9739 * with a leading '-' or '+': set -- $x
9741 * So far, we only support "set -- [argument...]" and some of the short names.
9743 static int FAST_FUNC builtin_set(char **argv)
9746 char **pp, **g_argv;
9747 char *arg = *++argv;
9751 for (e = G.top_var; e; e = e->next)
9753 return EXIT_SUCCESS;
9757 if (strcmp(arg, "--") == 0) {
9761 if (arg[0] != '+' && arg[0] != '-')
9763 for (n = 1; arg[n]; ++n) {
9764 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9766 if (arg[n] == 'o' && argv[1])
9769 } while ((arg = *++argv) != NULL);
9770 /* Now argv[0] is 1st argument */
9773 return EXIT_SUCCESS;
9776 /* NB: G.global_argv[0] ($0) is never freed/changed */
9777 g_argv = G.global_argv;
9778 if (G.global_args_malloced) {
9784 G.global_args_malloced = 1;
9785 pp = xzalloc(sizeof(pp[0]) * 2);
9786 pp[0] = g_argv[0]; /* retain $0 */
9789 /* This realloc's G.global_argv */
9790 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9792 G.global_argc = 1 + string_array_len(pp + 1);
9794 return EXIT_SUCCESS;
9796 /* Nothing known, so abort */
9798 bb_error_msg("set: %s: invalid option", arg);
9799 return EXIT_FAILURE;
9803 static int FAST_FUNC builtin_shift(char **argv)
9806 argv = skip_dash_dash(argv);
9808 n = bb_strtou(argv[0], NULL, 10);
9809 if (errno || n < 0) {
9810 /* shared string with ash.c */
9811 bb_error_msg("Illegal number: %s", argv[0]);
9813 * ash aborts in this case.
9814 * bash prints error message and set $? to 1.
9815 * Interestingly, for "shift 99999" bash does not
9816 * print error message, but does set $? to 1
9817 * (and does no shifting at all).
9821 if (n >= 0 && n < G.global_argc) {
9822 if (G_global_args_malloced) {
9825 free(G.global_argv[m++]);
9828 memmove(&G.global_argv[1], &G.global_argv[n+1],
9829 G.global_argc * sizeof(G.global_argv[0]));
9830 return EXIT_SUCCESS;
9832 return EXIT_FAILURE;
9835 static int FAST_FUNC builtin_source(char **argv)
9837 char *arg_path, *filename;
9840 char *args_need_save;
9841 #if ENABLE_HUSH_FUNCTIONS
9845 argv = skip_dash_dash(argv);
9848 /* bash says: "bash: .: filename argument required" */
9849 return 2; /* bash compat */
9852 if (!strchr(filename, '/')) {
9853 arg_path = find_in_path(filename);
9855 filename = arg_path;
9857 input = remember_FILE(fopen_or_warn(filename, "r"));
9860 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9861 /* POSIX: non-interactive shell should abort here,
9862 * not merely fail. So far no one complained :)
9864 return EXIT_FAILURE;
9867 #if ENABLE_HUSH_FUNCTIONS
9868 sv_flg = G_flag_return_in_progress;
9869 /* "we are inside sourced file, ok to use return" */
9870 G_flag_return_in_progress = -1;
9872 args_need_save = argv[1]; /* used as a boolean variable */
9874 save_and_replace_G_args(&sv, argv);
9876 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9877 G.last_exitcode = 0;
9878 parse_and_run_file(input);
9879 fclose_and_forget(input);
9881 if (args_need_save) /* can't use argv[1] instead: "shift" can mangle it */
9882 restore_G_args(&sv, argv);
9883 #if ENABLE_HUSH_FUNCTIONS
9884 G_flag_return_in_progress = sv_flg;
9887 return G.last_exitcode;
9890 #if ENABLE_HUSH_TRAP
9891 static int FAST_FUNC builtin_trap(char **argv)
9897 G_traps = xzalloc(sizeof(G_traps[0]) * NSIG);
9902 /* No args: print all trapped */
9903 for (i = 0; i < NSIG; ++i) {
9906 print_escaped(G_traps[i]);
9907 /* note: bash adds "SIG", but only if invoked
9908 * as "bash". If called as "sh", or if set -o posix,
9909 * then it prints short signal names.
9910 * We are printing short names: */
9911 printf(" %s\n", get_signame(i));
9914 /*fflush_all(); - done after each builtin anyway */
9915 return EXIT_SUCCESS;
9919 /* If first arg is a number: reset all specified signals */
9920 sig = bb_strtou(*argv, NULL, 10);
9926 sighandler_t handler;
9928 sig = get_signum(*argv++);
9931 /* Mimic bash message exactly */
9932 bb_error_msg("trap: %s: invalid signal specification", argv[-1]);
9937 G_traps[sig] = xstrdup(new_cmd);
9939 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9940 get_signame(sig), sig, G_traps[sig]);
9942 /* There is no signal for 0 (EXIT) */
9947 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9949 /* We are removing trap handler */
9950 handler = pick_sighandler(sig);
9951 install_sighandler(sig, handler);
9956 if (!argv[1]) { /* no second arg */
9957 bb_error_msg("trap: invalid arguments");
9958 return EXIT_FAILURE;
9961 /* First arg is "-": reset all specified to default */
9962 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9963 /* Everything else: set arg as signal handler
9964 * (includes "" case, which ignores signal) */
9965 if (argv[0][0] == '-') {
9966 if (argv[0][1] == '\0') { /* "-" */
9967 /* new_cmd remains NULL: "reset these sigs" */
9970 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9973 /* else: "-something", no special meaning */
9978 goto process_sig_list;
9983 static struct pipe *parse_jobspec(const char *str)
9988 if (sscanf(str, "%%%u", &jobnum) != 1) {
9990 || (str[1] != '%' && str[1] != '+' && str[1] != '\0')
9992 bb_error_msg("bad argument '%s'", str);
9995 /* It is "%%", "%+" or "%" - current job */
9996 jobnum = G.last_jobid;
9998 bb_error_msg("no current job");
10002 for (pi = G.job_list; pi; pi = pi->next) {
10003 if (pi->jobid == jobnum) {
10007 bb_error_msg("%u: no such job", jobnum);
10011 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
10014 const char *status_string;
10016 checkjobs(NULL, 0 /*(no pid to wait for)*/);
10017 for (job = G.job_list; job; job = job->next) {
10018 if (job->alive_cmds == job->stopped_cmds)
10019 status_string = "Stopped";
10021 status_string = "Running";
10023 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
10026 clean_up_last_dead_job();
10028 return EXIT_SUCCESS;
10031 /* built-in 'fg' and 'bg' handler */
10032 static int FAST_FUNC builtin_fg_bg(char **argv)
10037 if (!G_interactive_fd)
10038 return EXIT_FAILURE;
10040 /* If they gave us no args, assume they want the last backgrounded task */
10042 for (pi = G.job_list; pi; pi = pi->next) {
10043 if (pi->jobid == G.last_jobid) {
10047 bb_error_msg("%s: no current job", argv[0]);
10048 return EXIT_FAILURE;
10051 pi = parse_jobspec(argv[1]);
10053 return EXIT_FAILURE;
10055 /* TODO: bash prints a string representation
10056 * of job being foregrounded (like "sleep 1 | cat") */
10057 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
10058 /* Put the job into the foreground. */
10059 tcsetpgrp(G_interactive_fd, pi->pgrp);
10062 /* Restart the processes in the job */
10063 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
10064 for (i = 0; i < pi->num_cmds; i++) {
10065 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
10067 pi->stopped_cmds = 0;
10069 i = kill(- pi->pgrp, SIGCONT);
10071 if (errno == ESRCH) {
10072 delete_finished_job(pi);
10073 return EXIT_SUCCESS;
10075 bb_perror_msg("kill (SIGCONT)");
10078 if (argv[0][0] == 'f') {
10079 remove_job_from_table(pi); /* FG job shouldn't be in job table */
10080 return checkjobs_and_fg_shell(pi);
10082 return EXIT_SUCCESS;
10086 #if ENABLE_HUSH_KILL
10087 static int FAST_FUNC builtin_kill(char **argv)
10091 # if ENABLE_HUSH_JOB
10092 if (argv[1] && strcmp(argv[1], "-l") != 0) {
10100 if (argv[i][0] != '%')
10103 * "kill %N" - job kill
10104 * Converting to pgrp / pid kill
10106 pi = parse_jobspec(argv[i]);
10108 /* Eat bad jobspec */
10112 argv[j - 1] = argv[j];
10119 * In jobs started under job control, we signal
10120 * entire process group by kill -PGRP_ID.
10121 * This happens, f.e., in interactive shell.
10123 * Otherwise, we signal each child via
10124 * kill PID1 PID2 PID3.
10126 * sh -c 'sleep 1|sleep 1 & kill %1'
10127 * sh -c 'true|sleep 2 & sleep 1; kill %1'
10128 * sh -c 'true|sleep 1 & sleep 2; kill %1'
10130 n = G_interactive_fd ? 1 : pi->num_cmds;
10131 dst = alloca(n * sizeof(int)*4);
10133 if (G_interactive_fd)
10134 dst += sprintf(dst, " -%u", (int)pi->pgrp);
10135 else for (j = 0; j < n; j++) {
10136 struct command *cmd = &pi->cmds[j];
10137 /* Skip exited members of the job */
10141 * kill_main has matching code to expect
10142 * leading space. Needed to not confuse
10143 * negative pids with "kill -SIGNAL_NO" syntax
10145 dst += sprintf(dst, " %u", (int)cmd->pid);
10148 } while (argv[++i]);
10152 if (argv[1] || ret == 0) {
10153 ret = run_applet_main(argv, kill_main);
10155 /* else: ret = 1, "kill %bad_jobspec" case */
10160 #if ENABLE_HUSH_WAIT
10161 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
10162 #if !ENABLE_HUSH_JOB
10163 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
10165 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
10172 if (!sigisemptyset(&G.pending_set))
10175 /* waitpid is not interruptible by SA_RESTARTed
10176 * signals which we use. Thus, this ugly dance:
10179 /* Make sure possible SIGCHLD is stored in kernel's
10180 * pending signal mask before we call waitpid.
10181 * Or else we may race with SIGCHLD, lose it,
10182 * and get stuck in sigsuspend...
10184 sigfillset(&oldset); /* block all signals, remember old set */
10185 sigprocmask(SIG_SETMASK, &oldset, &oldset);
10187 if (!sigisemptyset(&G.pending_set)) {
10188 /* Crap! we raced with some signal! */
10192 /*errno = 0; - checkjobs does this */
10193 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
10194 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
10195 debug_printf_exec("checkjobs:%d\n", ret);
10196 #if ENABLE_HUSH_JOB
10197 if (waitfor_pipe) {
10198 int rcode = job_exited_or_stopped(waitfor_pipe);
10199 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
10202 sigprocmask(SIG_SETMASK, &oldset, NULL);
10207 /* if ECHILD, there are no children (ret is -1 or 0) */
10208 /* if ret == 0, no children changed state */
10209 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
10210 if (errno == ECHILD || ret) {
10212 if (ret < 0) /* if ECHILD, may need to fix "ret" */
10214 sigprocmask(SIG_SETMASK, &oldset, NULL);
10217 /* Wait for SIGCHLD or any other signal */
10218 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
10219 /* Note: sigsuspend invokes signal handler */
10220 sigsuspend(&oldset);
10222 sigprocmask(SIG_SETMASK, &oldset, NULL);
10224 /* So, did we get a signal? */
10225 sig = check_and_run_traps();
10226 if (sig /*&& sig != SIGCHLD - always true */) {
10227 /* Do this for any (non-ignored) signal, not only for ^C */
10231 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
10236 static int FAST_FUNC builtin_wait(char **argv)
10241 argv = skip_dash_dash(argv);
10242 if (argv[0] == NULL) {
10243 /* Don't care about wait results */
10244 /* Note 1: must wait until there are no more children */
10245 /* Note 2: must be interruptible */
10247 * $ sleep 3 & sleep 6 & wait
10248 * [1] 30934 sleep 3
10249 * [2] 30935 sleep 6
10252 * $ sleep 3 & sleep 6 & wait
10253 * [1] 30936 sleep 3
10254 * [2] 30937 sleep 6
10256 * ^C <-- after ~4 sec from keyboard
10259 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
10263 pid_t pid = bb_strtou(*argv, NULL, 10);
10264 if (errno || pid <= 0) {
10265 #if ENABLE_HUSH_JOB
10266 if (argv[0][0] == '%') {
10267 struct pipe *wait_pipe;
10268 ret = 127; /* bash compat for bad jobspecs */
10269 wait_pipe = parse_jobspec(*argv);
10271 ret = job_exited_or_stopped(wait_pipe);
10273 ret = wait_for_child_or_signal(wait_pipe, 0);
10275 /* waiting on "last dead job" removes it */
10276 clean_up_last_dead_job();
10279 /* else: parse_jobspec() already emitted error msg */
10283 /* mimic bash message */
10284 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
10285 ret = EXIT_FAILURE;
10286 continue; /* bash checks all argv[] */
10289 /* Do we have such child? */
10290 ret = waitpid(pid, &status, WNOHANG);
10294 if (errno == ECHILD) {
10295 if (pid == G.last_bg_pid) {
10296 /* "wait $!" but last bg task has already exited. Try:
10297 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
10298 * In bash it prints exitcode 0, then 3.
10299 * In dash, it is 127.
10301 ret = G.last_bg_pid_exitcode;
10303 /* Example: "wait 1". mimic bash message */
10304 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
10308 bb_perror_msg("wait %s", *argv);
10310 continue; /* bash checks all argv[] */
10313 /* Yes, and it still runs */
10314 ret = wait_for_child_or_signal(NULL, pid);
10316 /* Yes, and it just exited */
10317 process_wait_result(NULL, pid, status);
10318 ret = WEXITSTATUS(status);
10319 if (WIFSIGNALED(status))
10320 ret = 128 + WTERMSIG(status);
10328 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
10329 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
10332 def = bb_strtou(argv[1], NULL, 10);
10333 if (errno || def < def_min || argv[2]) {
10334 bb_error_msg("%s: bad arguments", argv[0]);
10342 #if ENABLE_HUSH_LOOPS
10343 static int FAST_FUNC builtin_break(char **argv)
10346 if (G.depth_of_loop == 0) {
10347 bb_error_msg("%s: only meaningful in a loop", argv[0]);
10348 /* if we came from builtin_continue(), need to undo "= 1" */
10349 G.flag_break_continue = 0;
10350 return EXIT_SUCCESS; /* bash compat */
10352 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
10354 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
10355 if (depth == UINT_MAX)
10356 G.flag_break_continue = BC_BREAK;
10357 if (G.depth_of_loop < depth)
10358 G.depth_break_continue = G.depth_of_loop;
10360 return EXIT_SUCCESS;
10363 static int FAST_FUNC builtin_continue(char **argv)
10365 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
10366 return builtin_break(argv);
10370 #if ENABLE_HUSH_FUNCTIONS
10371 static int FAST_FUNC builtin_return(char **argv)
10375 if (G_flag_return_in_progress != -1) {
10376 bb_error_msg("%s: not in a function or sourced script", argv[0]);
10377 return EXIT_FAILURE; /* bash compat */
10380 G_flag_return_in_progress = 1;
10383 * out of range: wraps around at 256, does not error out
10384 * non-numeric param:
10385 * f() { false; return qwe; }; f; echo $?
10386 * bash: return: qwe: numeric argument required <== we do this
10387 * 255 <== we also do this
10389 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);
10394 #if ENABLE_HUSH_MEMLEAK
10395 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
10400 # ifdef M_TRIM_THRESHOLD
10401 /* Optional. Reduces probability of false positives */
10404 /* Crude attempt to find where "free memory" starts,
10405 * sans fragmentation. */
10407 l = (unsigned long)p;
10410 if (l < (unsigned long)p) l = (unsigned long)p;
10416 struct mallinfo mi = mallinfo();
10417 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
10418 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
10422 if (!G.memleak_value)
10423 G.memleak_value = l;
10425 l -= G.memleak_value;
10432 /* Exitcode is "how many kilobytes we leaked since 1st call" */