1 /* vi: set sw=4 ts=4: */
3 * A prototype Bourne shell grammar parser.
4 * Intended to follow the original Thompson and Ritchie
5 * "small and simple is beautiful" philosophy, which
6 * incidentally is a good match to today's BusyBox.
8 * Copyright (C) 2000,2001 Larry Doolittle <larry@doolittle.boa.org>
9 * Copyright (C) 2008,2009 Denys Vlasenko <vda.linux@googlemail.com>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 * The parser routines proper are all original material, first
15 * written Dec 2000 and Jan 2001 by Larry Doolittle. The
16 * execution engine, the builtins, and much of the underlying
17 * support has been adapted from busybox-0.49pre's lash, which is
18 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
19 * written by Erik Andersen <andersen@codepoet.org>. That, in turn,
20 * is based in part on ladsh.c, by Michael K. Johnson and Erik W.
21 * Troan, which they placed in the public domain. I don't know
22 * how much of the Johnson/Troan code has survived the repeated
26 * o_addchr derived from similar w_addchar function in glibc-2.2.
27 * parse_redirect, redirect_opt_num, and big chunks of main
28 * and many builtins derived from contributions by Erik Andersen.
29 * Miscellaneous bugfixes from Matt Kraai.
31 * There are two big (and related) architecture differences between
32 * this parser and the lash parser. One is that this version is
33 * actually designed from the ground up to understand nearly all
34 * of the Bourne grammar. The second, consequential change is that
35 * the parser and input reader have been turned inside out. Now,
36 * the parser is in control, and asks for input as needed. The old
37 * way had the input reader in control, and it asked for parsing to
38 * take place as needed. The new way makes it much easier to properly
39 * handle the recursion implicit in the various substitutions, especially
40 * across continuation lines.
43 * grep for "TODO" and fix (some of them are easy)
44 * special variables (done: PWD, PPID, RANDOM)
47 * follow IFS rules more precisely, including update semantics
48 * builtins mandated by standards we don't support:
49 * [un]alias, command, fc, getopts, newgrp, readonly, times
50 * make complex ${var%...} constructs support optional
51 * make here documents optional
54 * redirection of stdout+stderr: &> and >&
55 * reserved words: function select
56 * advanced test: [[ ]]
57 * process substitution: <(list) and >(list)
60 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
61 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
62 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
64 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
65 * This is exactly equivalent to let "EXPR".
66 * $[EXPR]: synonym for $((EXPR))
69 * In bash, export builtin is special, its arguments are assignments
70 * and therefore expansion of them should be "one-word" expansion:
71 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
73 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
74 * ls: cannot access i=a: No such file or directory
75 * ls: cannot access b: No such file or directory
76 * Note1: same applies to local builtin.
77 * Note2: bash 3.2.33(1) does this only if export word itself
79 * $ export i=`echo 'aaa bbb'`; echo "$i"
81 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
84 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
85 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
86 || defined(__APPLE__) \
88 # include <malloc.h> /* for malloc_trim */
91 /* #include <dmalloc.h> */
96 #include "shell_common.h"
99 #if ENABLE_HUSH_RANDOM_SUPPORT
102 # define CLEAR_RANDOM_T(rnd) ((void)0)
105 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
108 //applet:IF_HUSH(APPLET(hush, _BB_DIR_BIN, _BB_SUID_DROP))
109 //applet:IF_MSH(APPLET(msh, _BB_DIR_BIN, _BB_SUID_DROP))
110 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, _BB_DIR_BIN, _BB_SUID_DROP, sh))
111 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, _BB_DIR_BIN, _BB_SUID_DROP, bash))
113 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
114 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
117 //config: bool "hush"
120 //config: hush is a small shell (25k). It handles the normal flow control
121 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
122 //config: case/esac. Redirections, here documents, $((arithmetic))
123 //config: and functions are supported.
125 //config: It will compile and work on no-mmu systems.
127 //config: It does not handle select, aliases, tilde expansion,
128 //config: &>file and >&file redirection of stdout+stderr.
130 //config:config HUSH_BASH_COMPAT
131 //config: bool "bash-compatible extensions"
133 //config: depends on HUSH
135 //config: Enable bash-compatible extensions.
137 //config:config HUSH_BRACE_EXPANSION
138 //config: bool "Brace expansion"
140 //config: depends on HUSH_BASH_COMPAT
142 //config: Enable {abc,def} extension.
144 //config:config HUSH_HELP
145 //config: bool "help builtin"
147 //config: depends on HUSH
149 //config: Enable help builtin in hush. Code size + ~1 kbyte.
151 //config:config HUSH_INTERACTIVE
152 //config: bool "Interactive mode"
154 //config: depends on HUSH
156 //config: Enable interactive mode (prompt and command editing).
157 //config: Without this, hush simply reads and executes commands
158 //config: from stdin just like a shell script from a file.
159 //config: No prompt, no PS1/PS2 magic shell variables.
161 //config:config HUSH_SAVEHISTORY
162 //config: bool "Save command history to .hush_history"
164 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
166 //config: Enable history saving in hush.
168 //config:config HUSH_JOB
169 //config: bool "Job control"
171 //config: depends on HUSH_INTERACTIVE
173 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
174 //config: command (not entire shell), fg/bg builtins work. Without this option,
175 //config: "cmd &" still works by simply spawning a process and immediately
176 //config: prompting for next command (or executing next command in a script),
177 //config: but no separate process group is formed.
179 //config:config HUSH_TICK
180 //config: bool "Process substitution"
182 //config: depends on HUSH
184 //config: Enable process substitution `command` and $(command) in hush.
186 //config:config HUSH_IF
187 //config: bool "Support if/then/elif/else/fi"
189 //config: depends on HUSH
191 //config: Enable if/then/elif/else/fi in hush.
193 //config:config HUSH_LOOPS
194 //config: bool "Support for, while and until loops"
196 //config: depends on HUSH
198 //config: Enable for, while and until loops in hush.
200 //config:config HUSH_CASE
201 //config: bool "Support case ... esac statement"
203 //config: depends on HUSH
205 //config: Enable case ... esac statement in hush. +400 bytes.
207 //config:config HUSH_FUNCTIONS
208 //config: bool "Support funcname() { commands; } syntax"
210 //config: depends on HUSH
212 //config: Enable support for shell functions in hush. +800 bytes.
214 //config:config HUSH_LOCAL
215 //config: bool "Support local builtin"
217 //config: depends on HUSH_FUNCTIONS
219 //config: Enable support for local variables in functions.
221 //config:config HUSH_RANDOM_SUPPORT
222 //config: bool "Pseudorandom generator and $RANDOM variable"
224 //config: depends on HUSH
226 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
227 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
229 //config:config HUSH_EXPORT_N
230 //config: bool "Support 'export -n' option"
232 //config: depends on HUSH
234 //config: export -n unexports variables. It is a bash extension.
236 //config:config HUSH_MODE_X
237 //config: bool "Support 'hush -x' option and 'set -x' command"
239 //config: depends on HUSH
241 //config: This instructs hush to print commands before execution.
242 //config: Adds ~300 bytes.
245 //config: bool "msh (deprecated: aliased to hush)"
247 //config: select HUSH
249 //config: msh is deprecated and will be removed, please migrate to hush.
252 /* -i (interactive) and -s (read stdin) are also accepted,
253 * but currently do nothing, therefore aren't shown in help.
254 * NOMMU-specific options are not meant to be used by users,
255 * therefore we don't show them either.
257 //usage:#define hush_trivial_usage
258 //usage: "[-nx] [-c SCRIPT]"
259 //usage:#define hush_full_usage ""
260 //usage:#define msh_trivial_usage hush_trivial_usage
261 //usage:#define msh_full_usage ""
262 //usage:#define sh_trivial_usage NOUSAGE_STR
263 //usage:#define sh_full_usage ""
264 //usage:#define bash_trivial_usage NOUSAGE_STR
265 //usage:#define bash_full_usage ""
269 #define LEAK_HUNTING 0
270 #define BUILD_AS_NOMMU 0
271 /* Enable/disable sanity checks. Ok to enable in production,
272 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
273 * Keeping 1 for now even in released versions.
276 /* Slightly bigger (+200 bytes), but faster hush.
277 * So far it only enables a trick with counting SIGCHLDs and forks,
278 * which allows us to do fewer waitpid's.
279 * (we can detect a case where neither forks were done nor SIGCHLDs happened
280 * and therefore waitpid will return the same result as last time)
282 #define ENABLE_HUSH_FAST 0
283 /* TODO: implement simplified code for users which do not need ${var%...} ops
284 * So far ${var%...} ops are always enabled:
286 #define ENABLE_HUSH_DOLLAR_OPS 1
291 # undef USE_FOR_NOMMU
294 # define USE_FOR_NOMMU(...) __VA_ARGS__
295 # define USE_FOR_MMU(...)
298 #include "NUM_APPLETS.h"
300 /* STANDALONE does not make sense, and won't compile */
301 # undef CONFIG_FEATURE_SH_STANDALONE
302 # undef ENABLE_FEATURE_SH_STANDALONE
303 # undef IF_FEATURE_SH_STANDALONE
304 # undef IF_NOT_FEATURE_SH_STANDALONE
305 # define ENABLE_FEATURE_SH_STANDALONE 0
306 # define IF_FEATURE_SH_STANDALONE(...)
307 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
310 #if !ENABLE_HUSH_INTERACTIVE
311 # undef ENABLE_FEATURE_EDITING
312 # define ENABLE_FEATURE_EDITING 0
313 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
314 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
317 /* Do we support ANY keywords? */
318 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
319 # define HAS_KEYWORDS 1
320 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
321 # define IF_HAS_NO_KEYWORDS(...)
323 # define HAS_KEYWORDS 0
324 # define IF_HAS_KEYWORDS(...)
325 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
328 /* If you comment out one of these below, it will be #defined later
329 * to perform debug printfs to stderr: */
330 #define debug_printf(...) do {} while (0)
331 /* Finer-grained debug switches */
332 #define debug_printf_parse(...) do {} while (0)
333 #define debug_print_tree(a, b) do {} while (0)
334 #define debug_printf_exec(...) do {} while (0)
335 #define debug_printf_env(...) do {} while (0)
336 #define debug_printf_jobs(...) do {} while (0)
337 #define debug_printf_expand(...) do {} while (0)
338 #define debug_printf_varexp(...) do {} while (0)
339 #define debug_printf_glob(...) do {} while (0)
340 #define debug_printf_list(...) do {} while (0)
341 #define debug_printf_subst(...) do {} while (0)
342 #define debug_printf_clean(...) do {} while (0)
344 #define ERR_PTR ((void*)(long)1)
346 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
348 #define _SPECIAL_VARS_STR "_*@$!?#"
349 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
350 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
351 #if ENABLE_HUSH_BASH_COMPAT
352 /* Support / and // replace ops */
353 /* Note that // is stored as \ in "encoded" string representation */
354 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
355 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
356 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
358 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
359 # define VAR_SUBST_OPS "%#:-=+?"
360 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
363 #define SPECIAL_VAR_SYMBOL 3
367 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
369 /* This supports saving pointers malloced in vfork child,
370 * to be freed in the parent.
373 typedef struct nommu_save_t {
375 struct variable *old_vars;
377 char **argv_from_re_execing;
390 #if ENABLE_HUSH_LOOPS
397 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
402 /* three pseudo-keywords support contrived "case" syntax: */
403 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
404 RES_MATCH , /* "word)" */
405 RES_CASE_BODY, /* "this command is inside CASE" */
412 typedef struct o_string {
414 int length; /* position where data is appended */
417 /* At least some part of the string was inside '' or "",
418 * possibly empty one: word"", wo''rd etc. */
419 smallint has_quoted_part;
420 smallint has_empty_slot;
421 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
424 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
426 /* Protect newly added chars against globbing
427 * by prepending \ to *, ?, [, \ */
428 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
431 MAYBE_ASSIGNMENT = 0,
432 DEFINITELY_ASSIGNMENT = 1,
434 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
437 /* Used for initialization: o_string foo = NULL_O_STRING; */
438 #define NULL_O_STRING { NULL }
440 /* I can almost use ordinary FILE*. Is open_memstream() universally
441 * available? Where is it documented? */
442 typedef struct in_str {
444 /* eof_flag=1: last char in ->p is really an EOF */
445 char eof_flag; /* meaningless if ->p == NULL */
447 #if ENABLE_HUSH_INTERACTIVE
449 smallint promptmode; /* 0: PS1, 1: PS2 */
452 int (*get) (struct in_str *) FAST_FUNC;
453 int (*peek) (struct in_str *) FAST_FUNC;
455 #define i_getch(input) ((input)->get(input))
456 #define i_peek(input) ((input)->peek(input))
458 /* The descrip member of this structure is only used to make
459 * debugging output pretty */
460 static const struct {
462 signed char default_fd;
465 { O_RDONLY, 0, "<" },
466 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
467 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
468 { O_CREAT|O_RDWR, 1, "<>" },
469 { O_RDONLY, 0, "<<" },
470 /* Should not be needed. Bogus default_fd helps in debugging */
471 /* { O_RDONLY, 77, "<<" }, */
474 struct redir_struct {
475 struct redir_struct *next;
476 char *rd_filename; /* filename */
477 int rd_fd; /* fd to redirect */
478 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
480 smallint rd_type; /* (enum redir_type) */
481 /* note: for heredocs, rd_filename contains heredoc delimiter,
482 * and subsequently heredoc itself; and rd_dup is a bitmask:
483 * bit 0: do we need to trim leading tabs?
484 * bit 1: is heredoc quoted (<<'delim' syntax) ?
487 typedef enum redir_type {
489 REDIRECT_OVERWRITE = 1,
492 REDIRECT_HEREDOC = 4,
493 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
496 REDIRFD_SYNTAX_ERR = -2,
497 REDIRFD_TO_FILE = -1,
498 /* otherwise, rd_fd is redirected to rd_dup */
500 HEREDOC_SKIPTABS = 1,
506 pid_t pid; /* 0 if exited */
507 int assignment_cnt; /* how many argv[i] are assignments? */
508 smallint is_stopped; /* is the command currently running? */
509 smallint cmd_type; /* CMD_xxx */
511 #define CMD_SUBSHELL 1
512 #if ENABLE_HUSH_BASH_COMPAT
513 /* used for "[[ EXPR ]]" */
514 # define CMD_SINGLEWORD_NOGLOB 2
516 #if ENABLE_HUSH_FUNCTIONS
517 # define CMD_FUNCDEF 3
520 smalluint cmd_exitcode;
521 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
524 char *group_as_string;
526 #if ENABLE_HUSH_FUNCTIONS
527 struct function *child_func;
528 /* This field is used to prevent a bug here:
529 * while...do f1() {a;}; f1; f1() {b;}; f1; done
530 * When we execute "f1() {a;}" cmd, we create new function and clear
531 * cmd->group, cmd->group_as_string, cmd->argv[0].
532 * When we execute "f1() {b;}", we notice that f1 exists,
533 * and that its "parent cmd" struct is still "alive",
534 * we put those fields back into cmd->xxx
535 * (struct function has ->parent_cmd ptr to facilitate that).
536 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
537 * Without this trick, loop would execute a;b;b;b;...
538 * instead of correct sequence a;b;a;b;...
539 * When command is freed, it severs the link
540 * (sets ->child_func->parent_cmd to NULL).
543 char **argv; /* command name and arguments */
544 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
545 * and on execution these are substituted with their values.
546 * Substitution can make _several_ words out of one argv[n]!
547 * Example: argv[0]=='.^C*^C.' here: echo .$*.
548 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
550 struct redir_struct *redirects; /* I/O redirections */
552 /* Is there anything in this command at all? */
553 #define IS_NULL_CMD(cmd) \
554 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
558 int num_cmds; /* total number of commands in pipe */
559 int alive_cmds; /* number of commands running (not exited) */
560 int stopped_cmds; /* number of commands alive, but stopped */
562 int jobid; /* job number */
563 pid_t pgrp; /* process group ID for the job */
564 char *cmdtext; /* name of job */
566 struct command *cmds; /* array of commands in pipe */
567 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
568 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
569 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
571 typedef enum pipe_style {
577 /* Is there anything in this pipe at all? */
578 #define IS_NULL_PIPE(pi) \
579 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
581 /* This holds pointers to the various results of parsing */
582 struct parse_context {
583 /* linked list of pipes */
584 struct pipe *list_head;
585 /* last pipe (being constructed right now) */
587 /* last command in pipe (being constructed right now) */
588 struct command *command;
589 /* last redirect in command->redirects list */
590 struct redir_struct *pending_redirect;
596 smallint ctx_inverted; /* "! cmd | cmd" */
598 smallint ctx_dsemicolon; /* ";;" seen */
600 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
602 /* group we are enclosed in:
603 * example: "if pipe1; pipe2; then pipe3; fi"
604 * when we see "if" or "then", we malloc and copy current context,
605 * and make ->stack point to it. then we parse pipeN.
606 * when closing "then" / fi" / whatever is found,
607 * we move list_head into ->stack->command->group,
608 * copy ->stack into current context, and delete ->stack.
609 * (parsing of { list } and ( list ) doesn't use this method)
611 struct parse_context *stack;
615 /* On program start, environ points to initial environment.
616 * putenv adds new pointers into it, unsetenv removes them.
617 * Neither of these (de)allocates the strings.
618 * setenv allocates new strings in malloc space and does putenv,
619 * and thus setenv is unusable (leaky) for shell's purposes */
620 #define setenv(...) setenv_is_leaky_dont_use()
622 struct variable *next;
623 char *varstr; /* points to "name=" portion */
624 #if ENABLE_HUSH_LOCAL
625 unsigned func_nest_level;
627 int max_len; /* if > 0, name is part of initial env; else name is malloced */
628 smallint flg_export; /* putenv should be done on this var */
629 smallint flg_read_only;
637 #if ENABLE_HUSH_FUNCTIONS
639 struct function *next;
641 struct command *parent_cmd;
644 char *body_as_string;
650 /* set -/+o OPT support. (TODO: make it optional)
651 * bash supports the following opts:
662 * interactive-comments on
680 static const char o_opt_strings[] ALIGN1 =
683 #if ENABLE_HUSH_MODE_X
690 #if ENABLE_HUSH_MODE_X
697 /* "Globals" within this file */
698 /* Sorted roughly by size (smaller offsets == smaller code) */
700 /* interactive_fd != 0 means we are an interactive shell.
701 * If we are, then saved_tty_pgrp can also be != 0, meaning
702 * that controlling tty is available. With saved_tty_pgrp == 0,
703 * job control still works, but terminal signals
704 * (^C, ^Z, ^Y, ^\) won't work at all, and background
705 * process groups can only be created with "cmd &".
706 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
707 * to give tty to the foreground process group,
708 * and will take it back when the group is stopped (^Z)
711 #if ENABLE_HUSH_INTERACTIVE
712 /* 'interactive_fd' is a fd# open to ctty, if we have one
713 * _AND_ if we decided to act interactively */
717 # define G_interactive_fd (G.interactive_fd)
719 # define G_interactive_fd 0
721 #if ENABLE_FEATURE_EDITING
722 line_input_t *line_input_state;
727 #if ENABLE_HUSH_RANDOM_SUPPORT
733 pid_t saved_tty_pgrp;
734 struct pipe *job_list;
735 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
737 # define G_saved_tty_pgrp 0
739 char o_opt[NUM_OPT_O];
740 #if ENABLE_HUSH_MODE_X
741 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
745 smallint flag_SIGINT;
746 #if ENABLE_HUSH_LOOPS
747 smallint flag_break_continue;
749 #if ENABLE_HUSH_FUNCTIONS
750 /* 0: outside of a function (or sourced file)
751 * -1: inside of a function, ok to use return builtin
752 * 1: return is invoked, skip all till end of func
754 smallint flag_return_in_progress;
756 smallint exiting; /* used to prevent EXIT trap recursion */
757 /* These four support $?, $#, and $1 */
758 smalluint last_exitcode;
759 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
760 smalluint global_args_malloced;
761 smalluint inherited_set_is_saved;
762 /* how many non-NULL argv's we have. NB: $# + 1 */
766 char *argv0_for_re_execing;
768 #if ENABLE_HUSH_LOOPS
769 unsigned depth_break_continue;
770 unsigned depth_of_loop;
774 struct variable *top_var;
775 char **expanded_assignments;
776 #if ENABLE_HUSH_FUNCTIONS
777 struct function *top_func;
778 # if ENABLE_HUSH_LOCAL
779 struct variable **shadowed_vars_pp;
780 unsigned func_nest_level;
783 /* Signal and trap handling */
785 unsigned count_SIGCHLD;
786 unsigned handled_SIGCHLD;
787 smallint we_have_children;
789 /* which signals have non-DFL handler (even with no traps set)? */
790 unsigned non_DFL_mask;
791 char **traps; /* char *traps[NSIG] */
792 sigset_t blocked_set;
793 sigset_t inherited_set;
795 unsigned long memleak_value;
798 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
800 #define G (*ptr_to_globals)
801 /* Not #defining name to G.name - this quickly gets unwieldy
802 * (too many defines). Also, I actually prefer to see when a variable
803 * is global, thus "G." prefix is a useful hint */
804 #define INIT_G() do { \
805 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
809 /* Function prototypes for builtins */
810 static int builtin_cd(char **argv) FAST_FUNC;
811 static int builtin_echo(char **argv) FAST_FUNC;
812 static int builtin_eval(char **argv) FAST_FUNC;
813 static int builtin_exec(char **argv) FAST_FUNC;
814 static int builtin_exit(char **argv) FAST_FUNC;
815 static int builtin_export(char **argv) FAST_FUNC;
817 static int builtin_fg_bg(char **argv) FAST_FUNC;
818 static int builtin_jobs(char **argv) FAST_FUNC;
821 static int builtin_help(char **argv) FAST_FUNC;
823 #if ENABLE_HUSH_LOCAL
824 static int builtin_local(char **argv) FAST_FUNC;
827 static int builtin_memleak(char **argv) FAST_FUNC;
830 static int builtin_printf(char **argv) FAST_FUNC;
832 static int builtin_pwd(char **argv) FAST_FUNC;
833 static int builtin_read(char **argv) FAST_FUNC;
834 static int builtin_set(char **argv) FAST_FUNC;
835 static int builtin_shift(char **argv) FAST_FUNC;
836 static int builtin_source(char **argv) FAST_FUNC;
837 static int builtin_test(char **argv) FAST_FUNC;
838 static int builtin_trap(char **argv) FAST_FUNC;
839 static int builtin_type(char **argv) FAST_FUNC;
840 static int builtin_true(char **argv) FAST_FUNC;
841 static int builtin_umask(char **argv) FAST_FUNC;
842 static int builtin_unset(char **argv) FAST_FUNC;
843 static int builtin_wait(char **argv) FAST_FUNC;
844 #if ENABLE_HUSH_LOOPS
845 static int builtin_break(char **argv) FAST_FUNC;
846 static int builtin_continue(char **argv) FAST_FUNC;
848 #if ENABLE_HUSH_FUNCTIONS
849 static int builtin_return(char **argv) FAST_FUNC;
852 /* Table of built-in functions. They can be forked or not, depending on
853 * context: within pipes, they fork. As simple commands, they do not.
854 * When used in non-forking context, they can change global variables
855 * in the parent shell process. If forked, of course they cannot.
856 * For example, 'unset foo | whatever' will parse and run, but foo will
857 * still be set at the end. */
858 struct built_in_command {
860 int (*b_function)(char **argv) FAST_FUNC;
863 # define BLTIN(cmd, func, help) { cmd, func, help }
865 # define BLTIN(cmd, func, help) { cmd, func }
869 static const struct built_in_command bltins1[] = {
870 BLTIN("." , builtin_source , "Run commands in a file"),
871 BLTIN(":" , builtin_true , NULL),
873 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
875 #if ENABLE_HUSH_LOOPS
876 BLTIN("break" , builtin_break , "Exit from a loop"),
878 BLTIN("cd" , builtin_cd , "Change directory"),
879 #if ENABLE_HUSH_LOOPS
880 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
882 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
883 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
884 BLTIN("exit" , builtin_exit , "Exit"),
885 BLTIN("export" , builtin_export , "Set environment variables"),
887 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
890 BLTIN("help" , builtin_help , NULL),
893 BLTIN("jobs" , builtin_jobs , "List jobs"),
895 #if ENABLE_HUSH_LOCAL
896 BLTIN("local" , builtin_local , "Set local variables"),
899 BLTIN("memleak" , builtin_memleak , NULL),
901 BLTIN("read" , builtin_read , "Input into variable"),
902 #if ENABLE_HUSH_FUNCTIONS
903 BLTIN("return" , builtin_return , "Return from a function"),
905 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
906 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
907 #if ENABLE_HUSH_BASH_COMPAT
908 BLTIN("source" , builtin_source , "Run commands in a file"),
910 BLTIN("trap" , builtin_trap , "Trap signals"),
911 BLTIN("type" , builtin_type , "Show command type"),
912 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
913 BLTIN("umask" , builtin_umask , "Set file creation mask"),
914 BLTIN("unset" , builtin_unset , "Unset variables"),
915 BLTIN("wait" , builtin_wait , "Wait for process"),
917 /* For now, echo and test are unconditionally enabled.
918 * Maybe make it configurable? */
919 static const struct built_in_command bltins2[] = {
920 BLTIN("[" , builtin_test , NULL),
921 BLTIN("echo" , builtin_echo , NULL),
923 BLTIN("printf" , builtin_printf , NULL),
925 BLTIN("pwd" , builtin_pwd , NULL),
926 BLTIN("test" , builtin_test , NULL),
933 /* prevent disasters with G.debug_indent < 0 */
934 # define indent() fprintf(stderr, "%*s", (G.debug_indent * 2) & 0xff, "")
935 # define debug_enter() (G.debug_indent++)
936 # define debug_leave() (G.debug_indent--)
938 # define indent() ((void)0)
939 # define debug_enter() ((void)0)
940 # define debug_leave() ((void)0)
944 # define debug_printf(...) (indent(), fprintf(stderr, __VA_ARGS__))
947 #ifndef debug_printf_parse
948 # define debug_printf_parse(...) (indent(), fprintf(stderr, __VA_ARGS__))
951 #ifndef debug_printf_exec
952 #define debug_printf_exec(...) (indent(), fprintf(stderr, __VA_ARGS__))
955 #ifndef debug_printf_env
956 # define debug_printf_env(...) (indent(), fprintf(stderr, __VA_ARGS__))
959 #ifndef debug_printf_jobs
960 # define debug_printf_jobs(...) (indent(), fprintf(stderr, __VA_ARGS__))
961 # define DEBUG_JOBS 1
963 # define DEBUG_JOBS 0
966 #ifndef debug_printf_expand
967 # define debug_printf_expand(...) (indent(), fprintf(stderr, __VA_ARGS__))
968 # define DEBUG_EXPAND 1
970 # define DEBUG_EXPAND 0
973 #ifndef debug_printf_varexp
974 # define debug_printf_varexp(...) (indent(), fprintf(stderr, __VA_ARGS__))
977 #ifndef debug_printf_glob
978 # define debug_printf_glob(...) (indent(), fprintf(stderr, __VA_ARGS__))
979 # define DEBUG_GLOB 1
981 # define DEBUG_GLOB 0
984 #ifndef debug_printf_list
985 # define debug_printf_list(...) (indent(), fprintf(stderr, __VA_ARGS__))
988 #ifndef debug_printf_subst
989 # define debug_printf_subst(...) (indent(), fprintf(stderr, __VA_ARGS__))
992 #ifndef debug_printf_clean
993 # define debug_printf_clean(...) (indent(), fprintf(stderr, __VA_ARGS__))
994 # define DEBUG_CLEAN 1
996 # define DEBUG_CLEAN 0
1000 static void debug_print_strings(const char *prefix, char **vv)
1003 fprintf(stderr, "%s:\n", prefix);
1005 fprintf(stderr, " '%s'\n", *vv++);
1008 # define debug_print_strings(prefix, vv) ((void)0)
1012 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1015 static void *xxmalloc(int lineno, size_t size)
1017 void *ptr = xmalloc((size + 0xff) & ~0xff);
1018 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1021 static void *xxrealloc(int lineno, void *ptr, size_t size)
1023 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1024 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1027 static char *xxstrdup(int lineno, const char *str)
1029 char *ptr = xstrdup(str);
1030 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1033 static void xxfree(void *ptr)
1035 fdprintf(2, "free %p\n", ptr);
1038 # define xmalloc(s) xxmalloc(__LINE__, s)
1039 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1040 # define xstrdup(s) xxstrdup(__LINE__, s)
1041 # define free(p) xxfree(p)
1045 /* Syntax and runtime errors. They always abort scripts.
1046 * In interactive use they usually discard unparsed and/or unexecuted commands
1047 * and return to the prompt.
1048 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1051 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1052 # define syntax_error(lineno, msg) syntax_error(msg)
1053 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1054 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1055 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1056 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1059 static void die_if_script(unsigned lineno, const char *fmt, ...)
1064 bb_error_msg("hush.c:%u", lineno);
1067 bb_verror_msg(fmt, p, NULL);
1069 if (!G_interactive_fd)
1073 static void syntax_error(unsigned lineno, const char *msg)
1076 die_if_script(lineno, "syntax error: %s", msg);
1078 die_if_script(lineno, "syntax error", NULL);
1081 static void syntax_error_at(unsigned lineno, const char *msg)
1083 die_if_script(lineno, "syntax error at '%s'", msg);
1086 static void syntax_error_unterm_str(unsigned lineno, const char *s)
1088 die_if_script(lineno, "syntax error: unterminated %s", s);
1091 /* It so happens that all such cases are totally fatal
1092 * even if shell is interactive: EOF while looking for closing
1093 * delimiter. There is nowhere to read stuff from after that,
1094 * it's EOF! The only choice is to terminate.
1096 static void syntax_error_unterm_ch(unsigned lineno, char ch) NORETURN;
1097 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1099 char msg[2] = { ch, '\0' };
1100 syntax_error_unterm_str(lineno, msg);
1104 static void syntax_error_unexpected_ch(unsigned lineno, int ch)
1109 die_if_script(lineno, "syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1113 # undef die_if_script
1114 # undef syntax_error
1115 # undef syntax_error_at
1116 # undef syntax_error_unterm_ch
1117 # undef syntax_error_unterm_str
1118 # undef syntax_error_unexpected_ch
1120 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1121 # define syntax_error(msg) syntax_error(__LINE__, msg)
1122 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1123 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1124 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1125 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1129 #if ENABLE_HUSH_INTERACTIVE
1130 static void cmdedit_update_prompt(void);
1132 # define cmdedit_update_prompt() ((void)0)
1136 /* Utility functions
1138 /* Replace each \x with x in place, return ptr past NUL. */
1139 static char *unbackslash(char *src)
1141 char *dst = src = strchrnul(src, '\\');
1145 if ((*dst++ = *src++) == '\0')
1151 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1172 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1173 v[count1 + count2] = NULL;
1176 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1180 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1182 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1183 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1186 #define add_strings_to_strings(strings, add, need_to_dup) \
1187 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1190 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1191 static char **add_string_to_strings(char **strings, char *add)
1196 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1199 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1201 char **ptr = add_string_to_strings(strings, add);
1202 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1205 #define add_string_to_strings(strings, add) \
1206 xx_add_string_to_strings(__LINE__, strings, add)
1209 static void free_strings(char **strings)
1224 /* Helpers for setting new $n and restoring them back
1226 typedef struct save_arg_t {
1230 smallint sv_g_malloced;
1233 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1237 sv->sv_argv0 = argv[0];
1238 sv->sv_g_argv = G.global_argv;
1239 sv->sv_g_argc = G.global_argc;
1240 sv->sv_g_malloced = G.global_args_malloced;
1242 argv[0] = G.global_argv[0]; /* retain $0 */
1243 G.global_argv = argv;
1244 G.global_args_malloced = 0;
1252 static void restore_G_args(save_arg_t *sv, char **argv)
1256 if (G.global_args_malloced) {
1257 /* someone ran "set -- arg1 arg2 ...", undo */
1259 while (*++pp) /* note: does not free $0 */
1261 free(G.global_argv);
1263 argv[0] = sv->sv_argv0;
1264 G.global_argv = sv->sv_g_argv;
1265 G.global_argc = sv->sv_g_argc;
1266 G.global_args_malloced = sv->sv_g_malloced;
1270 /* Basic theory of signal handling in shell
1271 * ========================================
1272 * This does not describe what hush does, rather, it is current understanding
1273 * what it _should_ do. If it doesn't, it's a bug.
1274 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1276 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1277 * is finished or backgrounded. It is the same in interactive and
1278 * non-interactive shells, and is the same regardless of whether
1279 * a user trap handler is installed or a shell special one is in effect.
1280 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1281 * backgrounds (i.e. stops) or kills all members of currently running
1284 * Wait builtin in interruptible by signals for which user trap is set
1285 * or by SIGINT in interactive shell.
1287 * Trap handlers will execute even within trap handlers. (right?)
1289 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1290 * except for handlers set to '' (empty string).
1292 * If job control is off, backgrounded commands ("cmd &")
1293 * have SIGINT, SIGQUIT set to SIG_IGN.
1295 * Commands which are run in command substitution ("`cmd`")
1296 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1298 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1299 * by the shell from its parent.
1301 * Signals which differ from SIG_DFL action
1302 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1305 * SIGTERM (interactive): ignore
1306 * SIGHUP (interactive):
1307 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1308 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1309 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1310 * that all pipe members are stopped. Try this in bash:
1311 * while :; do :; done - ^Z does not background it
1312 * (while :; do :; done) - ^Z backgrounds it
1313 * SIGINT (interactive): wait for last pipe, ignore the rest
1314 * of the command line, show prompt. NB: ^C does not send SIGINT
1315 * to interactive shell while shell is waiting for a pipe,
1316 * since shell is bg'ed (is not in foreground process group).
1317 * Example 1: this waits 5 sec, but does not execute ls:
1318 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1319 * Example 2: this does not wait and does not execute ls:
1320 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1321 * Example 3: this does not wait 5 sec, but executes ls:
1322 * "sleep 5; ls -l" + press ^C
1324 * (What happens to signals which are IGN on shell start?)
1325 * (What happens with signal mask on shell start?)
1327 * Implementation in hush
1328 * ======================
1329 * We use in-kernel pending signal mask to determine which signals were sent.
1330 * We block all signals which we don't want to take action immediately,
1331 * i.e. we block all signals which need to have special handling as described
1332 * above, and all signals which have traps set.
1333 * After each pipe execution, we extract any pending signals via sigtimedwait()
1336 * unsigned non_DFL_mask: a mask of such "special" signals
1337 * sigset_t blocked_set: current blocked signal set
1340 * clear bit in blocked_set unless it is also in non_DFL_mask
1341 * "trap 'cmd' SIGxxx":
1342 * set bit in blocked_set (even if 'cmd' is '')
1343 * after [v]fork, if we plan to be a shell:
1344 * unblock signals with special interactive handling
1345 * (child shell is not interactive),
1346 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1347 * after [v]fork, if we plan to exec:
1348 * POSIX says fork clears pending signal mask in child - no need to clear it.
1349 * Restore blocked signal set to one inherited by shell just prior to exec.
1351 * Note: as a result, we do not use signal handlers much. The only uses
1352 * are to count SIGCHLDs
1353 * and to restore tty pgrp on signal-induced exit.
1356 * Standard says "When a subshell is entered, traps that are not being ignored
1357 * are set to the default actions". bash interprets it so that traps which
1358 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1361 SPECIAL_INTERACTIVE_SIGS = 0
1366 SPECIAL_JOB_SIGS = 0
1374 #if ENABLE_HUSH_FAST
1375 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1378 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1384 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1385 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1386 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1387 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1389 /* Restores tty foreground process group, and exits.
1390 * May be called as signal handler for fatal signal
1391 * (will resend signal to itself, producing correct exit state)
1392 * or called directly with -EXITCODE.
1393 * We also call it if xfunc is exiting. */
1394 static void sigexit(int sig) NORETURN;
1395 static void sigexit(int sig)
1397 /* Disable all signals: job control, SIGPIPE, etc. */
1398 sigprocmask_allsigs(SIG_BLOCK);
1400 /* Careful: we can end up here after [v]fork. Do not restore
1401 * tty pgrp then, only top-level shell process does that */
1402 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1403 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1405 /* Not a signal, just exit */
1409 kill_myself_with_sig(sig); /* does not return */
1413 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1414 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1418 /* Restores tty foreground process group, and exits. */
1419 static void hush_exit(int exitcode) NORETURN;
1420 static void hush_exit(int exitcode)
1422 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1423 /* Prevent recursion:
1424 * trap "echo Hi; exit" EXIT; exit
1427 /* argv[0] is unused */
1428 argv[1] = G.traps[0];
1430 G.exiting = 1; /* prevent EXIT trap recursion */
1431 /* Note: G.traps[0] is not cleared!
1432 * "trap" will still show it, if executed
1439 sigexit(- (exitcode & 0xff));
1446 static int check_and_run_traps(int sig)
1448 /* I want it in rodata, not in bss.
1449 * gcc 4.2.1 puts it in rodata only if it has { 0, 0 }
1450 * initializer. But other compilers may still use bss.
1451 * TODO: find more portable solution.
1453 static const struct timespec zero_timespec = { 0, 0 };
1454 smalluint save_rcode;
1460 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1465 if (G.traps && G.traps[sig]) {
1466 if (G.traps[sig][0]) {
1467 /* We have user-defined handler */
1469 /* argv[0] is unused */
1470 argv[1] = G.traps[sig];
1472 save_rcode = G.last_exitcode;
1474 G.last_exitcode = save_rcode;
1475 } /* else: "" trap, ignoring signal */
1478 /* not a trap: special action */
1480 #if ENABLE_HUSH_FAST
1483 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1487 /* Builtin was ^C'ed, make it look prettier: */
1494 /* bash is observed to signal whole process groups,
1495 * not individual processes */
1496 for (job = G.job_list; job; job = job->next) {
1499 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1500 if (kill(- job->pgrp, SIGHUP) == 0)
1501 kill(- job->pgrp, SIGCONT);
1506 default: /* ignored: */
1507 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1515 static const char *get_cwd(int force)
1517 if (force || G.cwd == NULL) {
1518 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1519 * we must not try to free(bb_msg_unknown) */
1520 if (G.cwd == bb_msg_unknown)
1522 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1524 G.cwd = bb_msg_unknown;
1531 * Shell and environment variable support
1533 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1535 struct variable **pp;
1536 struct variable *cur;
1539 while ((cur = *pp) != NULL) {
1540 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1547 static const char* FAST_FUNC get_local_var_value(const char *name)
1549 struct variable **vpp;
1550 unsigned len = strlen(name);
1552 if (G.expanded_assignments) {
1553 char **cpp = G.expanded_assignments;
1556 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1557 return cp + len + 1;
1562 vpp = get_ptr_to_local_var(name, len);
1564 return (*vpp)->varstr + len + 1;
1566 if (strcmp(name, "PPID") == 0)
1567 return utoa(G.root_ppid);
1568 // bash compat: UID? EUID?
1569 #if ENABLE_HUSH_RANDOM_SUPPORT
1570 if (strcmp(name, "RANDOM") == 0)
1571 return utoa(next_random(&G.random_gen));
1576 /* str holds "NAME=VAL" and is expected to be malloced.
1577 * We take ownership of it.
1579 * 0: do not change export flag
1580 * (if creating new variable, flag will be 0)
1581 * 1: set export flag and putenv the variable
1582 * -1: clear export flag and unsetenv the variable
1583 * flg_read_only is set only when we handle -R var=val
1585 #if !BB_MMU && ENABLE_HUSH_LOCAL
1586 /* all params are used */
1587 #elif BB_MMU && ENABLE_HUSH_LOCAL
1588 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1589 set_local_var(str, flg_export, local_lvl)
1590 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1591 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1592 set_local_var(str, flg_export)
1593 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1594 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1595 set_local_var(str, flg_export, flg_read_only)
1597 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1599 struct variable **var_pp;
1600 struct variable *cur;
1604 eq_sign = strchr(str, '=');
1605 if (!eq_sign) { /* not expected to ever happen? */
1610 name_len = eq_sign - str + 1; /* including '=' */
1611 var_pp = &G.top_var;
1612 while ((cur = *var_pp) != NULL) {
1613 if (strncmp(cur->varstr, str, name_len) != 0) {
1614 var_pp = &cur->next;
1617 /* We found an existing var with this name */
1618 if (cur->flg_read_only) {
1622 bb_error_msg("%s: readonly variable", str);
1626 if (flg_export == -1) { // "&& cur->flg_export" ?
1627 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1632 #if ENABLE_HUSH_LOCAL
1633 if (cur->func_nest_level < local_lvl) {
1634 /* New variable is declared as local,
1635 * and existing one is global, or local
1636 * from enclosing function.
1637 * Remove and save old one: */
1638 *var_pp = cur->next;
1639 cur->next = *G.shadowed_vars_pp;
1640 *G.shadowed_vars_pp = cur;
1641 /* bash 3.2.33(1) and exported vars:
1643 * # f() { local z=a; env | grep ^z; }
1649 if (cur->flg_export)
1654 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1659 if (cur->max_len != 0) {
1660 if (cur->max_len >= strlen(str)) {
1661 /* This one is from startup env, reuse space */
1662 strcpy(cur->varstr, str);
1666 /* max_len == 0 signifies "malloced" var, which we can
1667 * (and has to) free */
1671 goto set_str_and_exp;
1674 /* Not found - create new variable struct */
1675 cur = xzalloc(sizeof(*cur));
1676 #if ENABLE_HUSH_LOCAL
1677 cur->func_nest_level = local_lvl;
1679 cur->next = *var_pp;
1685 cur->flg_read_only = flg_read_only;
1688 if (flg_export == 1)
1689 cur->flg_export = 1;
1690 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1691 cmdedit_update_prompt();
1692 if (cur->flg_export) {
1693 if (flg_export == -1) {
1694 cur->flg_export = 0;
1695 /* unsetenv was already done */
1697 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1698 return putenv(cur->varstr);
1704 /* Used at startup and after each cd */
1705 static void set_pwd_var(int exp)
1707 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1708 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1711 static int unset_local_var_len(const char *name, int name_len)
1713 struct variable *cur;
1714 struct variable **var_pp;
1717 return EXIT_SUCCESS;
1718 var_pp = &G.top_var;
1719 while ((cur = *var_pp) != NULL) {
1720 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1721 if (cur->flg_read_only) {
1722 bb_error_msg("%s: readonly variable", name);
1723 return EXIT_FAILURE;
1725 *var_pp = cur->next;
1726 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1727 bb_unsetenv(cur->varstr);
1728 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1729 cmdedit_update_prompt();
1733 return EXIT_SUCCESS;
1735 var_pp = &cur->next;
1737 return EXIT_SUCCESS;
1740 static int unset_local_var(const char *name)
1742 return unset_local_var_len(name, strlen(name));
1745 static void unset_vars(char **strings)
1753 const char *eq = strchrnul(*v, '=');
1754 unset_local_var_len(*v, (int)(eq - *v));
1760 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1762 char *var = xasprintf("%s=%s", name, val);
1763 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1768 * Helpers for "var1=val1 var2=val2 cmd" feature
1770 static void add_vars(struct variable *var)
1772 struct variable *next;
1776 var->next = G.top_var;
1778 if (var->flg_export) {
1779 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1780 putenv(var->varstr);
1782 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1788 static struct variable *set_vars_and_save_old(char **strings)
1791 struct variable *old = NULL;
1797 struct variable *var_p;
1798 struct variable **var_pp;
1801 eq = strchr(*s, '=');
1803 var_pp = get_ptr_to_local_var(*s, eq - *s);
1805 /* Remove variable from global linked list */
1807 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1808 *var_pp = var_p->next;
1809 /* Add it to returned list */
1813 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1824 static int FAST_FUNC static_get(struct in_str *i)
1834 static int FAST_FUNC static_peek(struct in_str *i)
1839 #if ENABLE_HUSH_INTERACTIVE
1841 static void cmdedit_update_prompt(void)
1843 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1844 G.PS1 = get_local_var_value("PS1");
1847 G.PS2 = get_local_var_value("PS2");
1855 static const char *setup_prompt_string(int promptmode)
1857 const char *prompt_str;
1858 debug_printf("setup_prompt_string %d ", promptmode);
1859 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1860 /* Set up the prompt */
1861 if (promptmode == 0) { /* PS1 */
1863 /* bash uses $PWD value, even if it is set by user.
1864 * It uses current dir only if PWD is unset.
1865 * We always use current dir. */
1866 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1871 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1872 debug_printf("result '%s'\n", prompt_str);
1876 static void get_user_input(struct in_str *i)
1879 const char *prompt_str;
1881 prompt_str = setup_prompt_string(i->promptmode);
1882 # if ENABLE_FEATURE_EDITING
1883 /* Enable command line editing only while a command line
1884 * is actually being read */
1887 /* buglet: SIGINT will not make new prompt to appear _at once_,
1888 * only after <Enter>. (^C will work) */
1889 r = read_line_input(prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, G.line_input_state);
1890 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1891 check_and_run_traps(0);
1892 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1893 i->eof_flag = (r < 0);
1894 if (i->eof_flag) { /* EOF/error detected */
1895 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1896 G.user_input_buf[1] = '\0';
1901 fputs(prompt_str, stdout);
1903 G.user_input_buf[0] = r = fgetc(i->file);
1904 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1905 //do we need check_and_run_traps(0)? (maybe only if stdin)
1906 } while (G.flag_SIGINT);
1907 i->eof_flag = (r == EOF);
1909 i->p = G.user_input_buf;
1912 #endif /* INTERACTIVE */
1914 /* This is the magic location that prints prompts
1915 * and gets data back from the user */
1916 static int FAST_FUNC file_get(struct in_str *i)
1920 /* If there is data waiting, eat it up */
1921 if (i->p && *i->p) {
1922 #if ENABLE_HUSH_INTERACTIVE
1926 if (i->eof_flag && !*i->p)
1928 /* note: ch is never NUL */
1930 /* need to double check i->file because we might be doing something
1931 * more complicated by now, like sourcing or substituting. */
1932 #if ENABLE_HUSH_INTERACTIVE
1933 if (G_interactive_fd && i->promptme && i->file == stdin) {
1936 } while (!*i->p); /* need non-empty line */
1937 i->promptmode = 1; /* PS2 */
1942 do ch = fgetc(i->file); while (ch == '\0');
1944 debug_printf("file_get: got '%c' %d\n", ch, ch);
1945 #if ENABLE_HUSH_INTERACTIVE
1952 /* All callers guarantee this routine will never
1953 * be used right after a newline, so prompting is not needed.
1955 static int FAST_FUNC file_peek(struct in_str *i)
1958 if (i->p && *i->p) {
1959 if (i->eof_flag && !i->p[1])
1962 /* note: ch is never NUL */
1964 do ch = fgetc(i->file); while (ch == '\0');
1965 i->eof_flag = (ch == EOF);
1966 i->peek_buf[0] = ch;
1967 i->peek_buf[1] = '\0';
1969 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1973 static void setup_file_in_str(struct in_str *i, FILE *f)
1975 i->peek = file_peek;
1977 #if ENABLE_HUSH_INTERACTIVE
1979 i->promptmode = 0; /* PS1 */
1985 static void setup_string_in_str(struct in_str *i, const char *s)
1987 i->peek = static_peek;
1988 i->get = static_get;
1989 #if ENABLE_HUSH_INTERACTIVE
1991 i->promptmode = 0; /* PS1 */
2001 #define B_CHUNK (32 * sizeof(char*))
2003 static void o_reset_to_empty_unquoted(o_string *o)
2006 o->has_quoted_part = 0;
2011 static void o_free(o_string *o)
2014 memset(o, 0, sizeof(*o));
2017 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2022 static void o_grow_by(o_string *o, int len)
2024 if (o->length + len > o->maxlen) {
2025 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2026 o->data = xrealloc(o->data, 1 + o->maxlen);
2030 static void o_addchr(o_string *o, int ch)
2032 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2034 o->data[o->length] = ch;
2036 o->data[o->length] = '\0';
2039 static void o_addblock(o_string *o, const char *str, int len)
2042 memcpy(&o->data[o->length], str, len);
2044 o->data[o->length] = '\0';
2047 static void o_addstr(o_string *o, const char *str)
2049 o_addblock(o, str, strlen(str));
2053 static void nommu_addchr(o_string *o, int ch)
2059 # define nommu_addchr(o, str) ((void)0)
2062 static void o_addstr_with_NUL(o_string *o, const char *str)
2064 o_addblock(o, str, strlen(str) + 1);
2068 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2069 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2070 * Apparently, on unquoted $v bash still does globbing
2071 * ("v='*.txt'; echo $v" prints all .txt files),
2072 * but NOT brace expansion! Thus, there should be TWO independent
2073 * quoting mechanisms on $v expansion side: one protects
2074 * $v from brace expansion, and other additionally protects "$v" against globbing.
2075 * We have only second one.
2078 #if ENABLE_HUSH_BRACE_EXPANSION
2079 # define MAYBE_BRACES "{}"
2081 # define MAYBE_BRACES ""
2084 /* My analysis of quoting semantics tells me that state information
2085 * is associated with a destination, not a source.
2087 static void o_addqchr(o_string *o, int ch)
2090 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2095 o->data[o->length] = '\\';
2098 o->data[o->length] = ch;
2100 o->data[o->length] = '\0';
2103 static void o_addQchr(o_string *o, int ch)
2106 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2107 && strchr("*?[\\" MAYBE_BRACES, ch)
2110 o->data[o->length] = '\\';
2114 o->data[o->length] = ch;
2116 o->data[o->length] = '\0';
2119 static void o_addqblock(o_string *o, const char *str, int len)
2124 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2125 if (ordinary_cnt > len) /* paranoia */
2127 o_addblock(o, str, ordinary_cnt);
2128 if (ordinary_cnt == len)
2130 str += ordinary_cnt;
2131 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2135 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2137 o->data[o->length] = '\\';
2141 o->data[o->length] = ch;
2143 o->data[o->length] = '\0';
2147 static void o_addQblock(o_string *o, const char *str, int len)
2149 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2150 o_addblock(o, str, len);
2153 o_addqblock(o, str, len);
2156 static void o_addQstr(o_string *o, const char *str)
2158 o_addQblock(o, str, strlen(str));
2161 /* A special kind of o_string for $VAR and `cmd` expansion.
2162 * It contains char* list[] at the beginning, which is grown in 16 element
2163 * increments. Actual string data starts at the next multiple of 16 * (char*).
2164 * list[i] contains an INDEX (int!) into this string data.
2165 * It means that if list[] needs to grow, data needs to be moved higher up
2166 * but list[i]'s need not be modified.
2167 * NB: remembering how many list[i]'s you have there is crucial.
2168 * o_finalize_list() operation post-processes this structure - calculates
2169 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2171 #if DEBUG_EXPAND || DEBUG_GLOB
2172 static void debug_print_list(const char *prefix, o_string *o, int n)
2174 char **list = (char**)o->data;
2175 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2179 fprintf(stderr, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2180 prefix, list, n, string_start, o->length, o->maxlen,
2181 !!(o->o_expflags & EXP_FLAG_GLOB),
2183 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2186 fprintf(stderr, " list[%d]=%d '%s' %p\n", i, (int)list[i],
2187 o->data + (int)list[i] + string_start,
2188 o->data + (int)list[i] + string_start);
2192 const char *p = o->data + (int)list[n - 1] + string_start;
2194 fprintf(stderr, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2198 # define debug_print_list(prefix, o, n) ((void)0)
2201 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2202 * in list[n] so that it points past last stored byte so far.
2203 * It returns n+1. */
2204 static int o_save_ptr_helper(o_string *o, int n)
2206 char **list = (char**)o->data;
2210 if (!o->has_empty_slot) {
2211 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2212 string_len = o->length - string_start;
2213 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2214 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2215 /* list[n] points to string_start, make space for 16 more pointers */
2216 o->maxlen += 0x10 * sizeof(list[0]);
2217 o->data = xrealloc(o->data, o->maxlen + 1);
2218 list = (char**)o->data;
2219 memmove(list + n + 0x10, list + n, string_len);
2220 o->length += 0x10 * sizeof(list[0]);
2222 debug_printf_list("list[%d]=%d string_start=%d\n",
2223 n, string_len, string_start);
2226 /* We have empty slot at list[n], reuse without growth */
2227 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2228 string_len = o->length - string_start;
2229 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2230 n, string_len, string_start);
2231 o->has_empty_slot = 0;
2233 list[n] = (char*)(uintptr_t)string_len;
2237 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2238 static int o_get_last_ptr(o_string *o, int n)
2240 char **list = (char**)o->data;
2241 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2243 return ((int)(uintptr_t)list[n-1]) + string_start;
2246 #if ENABLE_HUSH_BRACE_EXPANSION
2247 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2248 * first, it processes even {a} (no commas), second,
2249 * I didn't manage to make it return strings when they don't match
2250 * existing files. Need to re-implement it.
2254 static int glob_needed(const char *s)
2263 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2269 /* Return pointer to next closing brace or to comma */
2270 static const char *next_brace_sub(const char *cp)
2274 while (*cp != '\0') {
2281 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2287 return *cp != '\0' ? cp : NULL;
2289 /* Recursive brace globber. Note: may garble pattern[]. */
2290 static int glob_brace(char *pattern, o_string *o, int n)
2292 char *new_pattern_buf;
2299 debug_printf_glob("glob_brace('%s')\n", pattern);
2305 if (*begin == '{') {
2306 /* Find the first sub-pattern and at the same time
2307 * find the rest after the closing brace */
2308 next = next_brace_sub(begin);
2310 /* An illegal expression */
2314 /* "{abc}" with no commas - illegal
2315 * brace expr, disregard and skip it */
2321 if (*begin == '\\' && begin[1] != '\0')
2325 debug_printf_glob("begin:%s\n", begin);
2326 debug_printf_glob("next:%s\n", next);
2328 /* Now find the end of the whole brace expression */
2330 while (*rest != '}') {
2331 rest = next_brace_sub(rest);
2333 /* An illegal expression */
2336 debug_printf_glob("rest:%s\n", rest);
2338 rest_len = strlen(++rest) + 1;
2340 /* We are sure the brace expression is well-formed */
2342 /* Allocate working buffer large enough for our work */
2343 new_pattern_buf = xmalloc(strlen(pattern));
2345 /* We have a brace expression. BEGIN points to the opening {,
2346 * NEXT points past the terminator of the first element, and REST
2347 * points past the final }. We will accumulate result names from
2348 * recursive runs for each brace alternative in the buffer using
2353 /* Construct the new glob expression */
2356 mempcpy(new_pattern_buf,
2357 /* We know the prefix for all sub-patterns */
2358 pattern, begin - pattern),
2362 /* Note: glob_brace() may garble new_pattern_buf[].
2363 * That's why we re-copy prefix every time (1st memcpy above).
2365 n = glob_brace(new_pattern_buf, o, n);
2367 /* We saw the last entry */
2371 next = next_brace_sub(next);
2373 free(new_pattern_buf);
2381 memset(&globdata, 0, sizeof(globdata));
2382 gr = glob(pattern, 0, NULL, &globdata);
2383 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2385 if (gr == GLOB_NOMATCH) {
2386 globfree(&globdata);
2387 /* NB: garbles parameter */
2388 unbackslash(pattern);
2389 o_addstr_with_NUL(o, pattern);
2390 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2391 return o_save_ptr_helper(o, n);
2393 if (gr == GLOB_NOSPACE)
2394 bb_error_msg_and_die(bb_msg_memory_exhausted);
2395 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2396 * but we didn't specify it. Paranoia again. */
2397 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2399 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2400 char **argv = globdata.gl_pathv;
2402 o_addstr_with_NUL(o, *argv);
2403 n = o_save_ptr_helper(o, n);
2409 globfree(&globdata);
2413 /* Performs globbing on last list[],
2414 * saving each result as a new list[].
2416 static int perform_glob(o_string *o, int n)
2418 char *pattern, *copy;
2420 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2422 return o_save_ptr_helper(o, n);
2423 pattern = o->data + o_get_last_ptr(o, n);
2424 debug_printf_glob("glob pattern '%s'\n", pattern);
2425 if (!glob_needed(pattern)) {
2426 /* unbackslash last string in o in place, fix length */
2427 o->length = unbackslash(pattern) - o->data;
2428 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2429 return o_save_ptr_helper(o, n);
2432 copy = xstrdup(pattern);
2433 /* "forget" pattern in o */
2434 o->length = pattern - o->data;
2435 n = glob_brace(copy, o, n);
2438 debug_print_list("perform_glob returning", o, n);
2442 #else /* !HUSH_BRACE_EXPANSION */
2445 static int glob_needed(const char *s)
2454 if (*s == '*' || *s == '[' || *s == '?')
2460 /* Performs globbing on last list[],
2461 * saving each result as a new list[].
2463 static int perform_glob(o_string *o, int n)
2469 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2471 return o_save_ptr_helper(o, n);
2472 pattern = o->data + o_get_last_ptr(o, n);
2473 debug_printf_glob("glob pattern '%s'\n", pattern);
2474 if (!glob_needed(pattern)) {
2476 /* unbackslash last string in o in place, fix length */
2477 o->length = unbackslash(pattern) - o->data;
2478 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2479 return o_save_ptr_helper(o, n);
2482 memset(&globdata, 0, sizeof(globdata));
2483 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2484 * If we glob "*.\*" and don't find anything, we need
2485 * to fall back to using literal "*.*", but GLOB_NOCHECK
2486 * will return "*.\*"!
2488 gr = glob(pattern, 0, NULL, &globdata);
2489 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2491 if (gr == GLOB_NOMATCH) {
2492 globfree(&globdata);
2495 if (gr == GLOB_NOSPACE)
2496 bb_error_msg_and_die(bb_msg_memory_exhausted);
2497 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2498 * but we didn't specify it. Paranoia again. */
2499 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2501 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2502 char **argv = globdata.gl_pathv;
2503 /* "forget" pattern in o */
2504 o->length = pattern - o->data;
2506 o_addstr_with_NUL(o, *argv);
2507 n = o_save_ptr_helper(o, n);
2513 globfree(&globdata);
2515 debug_print_list("perform_glob returning", o, n);
2519 #endif /* !HUSH_BRACE_EXPANSION */
2521 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2522 * Otherwise, just finish current list[] and start new */
2523 static int o_save_ptr(o_string *o, int n)
2525 if (o->o_expflags & EXP_FLAG_GLOB) {
2526 /* If o->has_empty_slot, list[n] was already globbed
2527 * (if it was requested back then when it was filled)
2528 * so don't do that again! */
2529 if (!o->has_empty_slot)
2530 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2532 return o_save_ptr_helper(o, n);
2535 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2536 static char **o_finalize_list(o_string *o, int n)
2541 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2543 debug_print_list("finalized", o, n);
2544 debug_printf_expand("finalized n:%d\n", n);
2545 list = (char**)o->data;
2546 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2550 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2555 static void free_pipe_list(struct pipe *pi);
2557 /* Returns pi->next - next pipe in the list */
2558 static struct pipe *free_pipe(struct pipe *pi)
2563 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2564 for (i = 0; i < pi->num_cmds; i++) {
2565 struct command *command;
2566 struct redir_struct *r, *rnext;
2568 command = &pi->cmds[i];
2569 debug_printf_clean(" command %d:\n", i);
2570 if (command->argv) {
2574 for (a = 0, p = command->argv; *p; a++, p++) {
2575 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2578 free_strings(command->argv);
2579 //command->argv = NULL;
2581 /* not "else if": on syntax error, we may have both! */
2582 if (command->group) {
2583 debug_printf_clean(" begin group (cmd_type:%d)\n",
2585 free_pipe_list(command->group);
2586 debug_printf_clean(" end group\n");
2587 //command->group = NULL;
2589 /* else is crucial here.
2590 * If group != NULL, child_func is meaningless */
2591 #if ENABLE_HUSH_FUNCTIONS
2592 else if (command->child_func) {
2593 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2594 command->child_func->parent_cmd = NULL;
2598 free(command->group_as_string);
2599 //command->group_as_string = NULL;
2601 for (r = command->redirects; r; r = rnext) {
2602 debug_printf_clean(" redirect %d%s",
2603 r->rd_fd, redir_table[r->rd_type].descrip);
2604 /* guard against the case >$FOO, where foo is unset or blank */
2605 if (r->rd_filename) {
2606 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2607 free(r->rd_filename);
2608 //r->rd_filename = NULL;
2610 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2614 //command->redirects = NULL;
2616 free(pi->cmds); /* children are an array, they get freed all at once */
2620 //pi->cmdtext = NULL;
2628 static void free_pipe_list(struct pipe *pi)
2632 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2634 debug_printf_clean("pipe followup code %d\n", pi->followup);
2640 /*** Parsing routines ***/
2642 #ifndef debug_print_tree
2643 static void debug_print_tree(struct pipe *pi, int lvl)
2645 static const char *const PIPE[] = {
2651 static const char *RES[] = {
2652 [RES_NONE ] = "NONE" ,
2655 [RES_THEN ] = "THEN" ,
2656 [RES_ELIF ] = "ELIF" ,
2657 [RES_ELSE ] = "ELSE" ,
2660 # if ENABLE_HUSH_LOOPS
2661 [RES_FOR ] = "FOR" ,
2662 [RES_WHILE] = "WHILE",
2663 [RES_UNTIL] = "UNTIL",
2665 [RES_DONE ] = "DONE" ,
2667 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2670 # if ENABLE_HUSH_CASE
2671 [RES_CASE ] = "CASE" ,
2672 [RES_CASE_IN ] = "CASE_IN" ,
2673 [RES_MATCH] = "MATCH",
2674 [RES_CASE_BODY] = "CASE_BODY",
2675 [RES_ESAC ] = "ESAC" ,
2677 [RES_XXXX ] = "XXXX" ,
2678 [RES_SNTX ] = "SNTX" ,
2680 static const char *const CMDTYPE[] = {
2684 # if ENABLE_HUSH_FUNCTIONS
2693 fprintf(stderr, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2694 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2696 while (prn < pi->num_cmds) {
2697 struct command *command = &pi->cmds[prn];
2698 char **argv = command->argv;
2700 fprintf(stderr, "%*s cmd %d assignment_cnt:%d",
2702 command->assignment_cnt);
2703 if (command->group) {
2704 fprintf(stderr, " group %s: (argv=%p)%s%s\n",
2705 CMDTYPE[command->cmd_type],
2708 , " group_as_string:", command->group_as_string
2713 debug_print_tree(command->group, lvl+1);
2717 if (argv) while (*argv) {
2718 fprintf(stderr, " '%s'", *argv);
2721 fprintf(stderr, "\n");
2728 #endif /* debug_print_tree */
2730 static struct pipe *new_pipe(void)
2733 pi = xzalloc(sizeof(struct pipe));
2734 /*pi->followup = 0; - deliberately invalid value */
2735 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2739 /* Command (member of a pipe) is complete, or we start a new pipe
2740 * if ctx->command is NULL.
2741 * No errors possible here.
2743 static int done_command(struct parse_context *ctx)
2745 /* The command is really already in the pipe structure, so
2746 * advance the pipe counter and make a new, null command. */
2747 struct pipe *pi = ctx->pipe;
2748 struct command *command = ctx->command;
2751 if (IS_NULL_CMD(command)) {
2752 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2756 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2757 //debug_print_tree(ctx->list_head, 20);
2759 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2762 /* Only real trickiness here is that the uncommitted
2763 * command structure is not counted in pi->num_cmds. */
2764 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2765 ctx->command = command = &pi->cmds[pi->num_cmds];
2767 memset(command, 0, sizeof(*command));
2768 return pi->num_cmds; /* used only for 0/nonzero check */
2771 static void done_pipe(struct parse_context *ctx, pipe_style type)
2775 debug_printf_parse("done_pipe entered, followup %d\n", type);
2776 /* Close previous command */
2777 not_null = done_command(ctx);
2778 ctx->pipe->followup = type;
2780 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2781 ctx->ctx_inverted = 0;
2782 ctx->pipe->res_word = ctx->ctx_res_w;
2785 /* Without this check, even just <enter> on command line generates
2786 * tree of three NOPs (!). Which is harmless but annoying.
2787 * IOW: it is safe to do it unconditionally. */
2790 || ctx->ctx_res_w == RES_FI
2792 #if ENABLE_HUSH_LOOPS
2793 || ctx->ctx_res_w == RES_DONE
2794 || ctx->ctx_res_w == RES_FOR
2795 || ctx->ctx_res_w == RES_IN
2797 #if ENABLE_HUSH_CASE
2798 || ctx->ctx_res_w == RES_ESAC
2802 debug_printf_parse("done_pipe: adding new pipe: "
2803 "not_null:%d ctx->ctx_res_w:%d\n",
2804 not_null, ctx->ctx_res_w);
2806 ctx->pipe->next = new_p;
2808 /* RES_THEN, RES_DO etc are "sticky" -
2809 * they remain set for pipes inside if/while.
2810 * This is used to control execution.
2811 * RES_FOR and RES_IN are NOT sticky (needed to support
2812 * cases where variable or value happens to match a keyword):
2814 #if ENABLE_HUSH_LOOPS
2815 if (ctx->ctx_res_w == RES_FOR
2816 || ctx->ctx_res_w == RES_IN)
2817 ctx->ctx_res_w = RES_NONE;
2819 #if ENABLE_HUSH_CASE
2820 if (ctx->ctx_res_w == RES_MATCH)
2821 ctx->ctx_res_w = RES_CASE_BODY;
2822 if (ctx->ctx_res_w == RES_CASE)
2823 ctx->ctx_res_w = RES_CASE_IN;
2825 ctx->command = NULL; /* trick done_command below */
2826 /* Create the memory for command, roughly:
2827 * ctx->pipe->cmds = new struct command;
2828 * ctx->command = &ctx->pipe->cmds[0];
2831 //debug_print_tree(ctx->list_head, 10);
2833 debug_printf_parse("done_pipe return\n");
2836 static void initialize_context(struct parse_context *ctx)
2838 memset(ctx, 0, sizeof(*ctx));
2839 ctx->pipe = ctx->list_head = new_pipe();
2840 /* Create the memory for command, roughly:
2841 * ctx->pipe->cmds = new struct command;
2842 * ctx->command = &ctx->pipe->cmds[0];
2847 /* If a reserved word is found and processed, parse context is modified
2848 * and 1 is returned.
2851 struct reserved_combo {
2854 unsigned char assignment_flag;
2858 FLAG_END = (1 << RES_NONE ),
2860 FLAG_IF = (1 << RES_IF ),
2861 FLAG_THEN = (1 << RES_THEN ),
2862 FLAG_ELIF = (1 << RES_ELIF ),
2863 FLAG_ELSE = (1 << RES_ELSE ),
2864 FLAG_FI = (1 << RES_FI ),
2866 # if ENABLE_HUSH_LOOPS
2867 FLAG_FOR = (1 << RES_FOR ),
2868 FLAG_WHILE = (1 << RES_WHILE),
2869 FLAG_UNTIL = (1 << RES_UNTIL),
2870 FLAG_DO = (1 << RES_DO ),
2871 FLAG_DONE = (1 << RES_DONE ),
2872 FLAG_IN = (1 << RES_IN ),
2874 # if ENABLE_HUSH_CASE
2875 FLAG_MATCH = (1 << RES_MATCH),
2876 FLAG_ESAC = (1 << RES_ESAC ),
2878 FLAG_START = (1 << RES_XXXX ),
2881 static const struct reserved_combo* match_reserved_word(o_string *word)
2883 /* Mostly a list of accepted follow-up reserved words.
2884 * FLAG_END means we are done with the sequence, and are ready
2885 * to turn the compound list into a command.
2886 * FLAG_START means the word must start a new compound list.
2888 static const struct reserved_combo reserved_list[] = {
2890 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2891 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2892 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2893 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2894 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2895 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2897 # if ENABLE_HUSH_LOOPS
2898 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2899 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2900 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2901 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2902 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2903 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2905 # if ENABLE_HUSH_CASE
2906 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2907 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2910 const struct reserved_combo *r;
2912 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2913 if (strcmp(word->data, r->literal) == 0)
2918 /* Return 0: not a keyword, 1: keyword
2920 static int reserved_word(o_string *word, struct parse_context *ctx)
2922 # if ENABLE_HUSH_CASE
2923 static const struct reserved_combo reserved_match = {
2924 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2927 const struct reserved_combo *r;
2929 if (word->has_quoted_part)
2931 r = match_reserved_word(word);
2935 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2936 # if ENABLE_HUSH_CASE
2937 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2938 /* "case word IN ..." - IN part starts first MATCH part */
2939 r = &reserved_match;
2942 if (r->flag == 0) { /* '!' */
2943 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2944 syntax_error("! ! command");
2945 ctx->ctx_res_w = RES_SNTX;
2947 ctx->ctx_inverted = 1;
2950 if (r->flag & FLAG_START) {
2951 struct parse_context *old;
2953 old = xmalloc(sizeof(*old));
2954 debug_printf_parse("push stack %p\n", old);
2955 *old = *ctx; /* physical copy */
2956 initialize_context(ctx);
2958 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2959 syntax_error_at(word->data);
2960 ctx->ctx_res_w = RES_SNTX;
2963 /* "{...} fi" is ok. "{...} if" is not
2965 * if { echo foo; } then { echo bar; } fi */
2966 if (ctx->command->group)
2967 done_pipe(ctx, PIPE_SEQ);
2970 ctx->ctx_res_w = r->res;
2971 ctx->old_flag = r->flag;
2972 word->o_assignment = r->assignment_flag;
2974 if (ctx->old_flag & FLAG_END) {
2975 struct parse_context *old;
2977 done_pipe(ctx, PIPE_SEQ);
2978 debug_printf_parse("pop stack %p\n", ctx->stack);
2980 old->command->group = ctx->list_head;
2981 old->command->cmd_type = CMD_NORMAL;
2983 o_addstr(&old->as_string, ctx->as_string.data);
2984 o_free_unsafe(&ctx->as_string);
2985 old->command->group_as_string = xstrdup(old->as_string.data);
2986 debug_printf_parse("pop, remembering as:'%s'\n",
2987 old->command->group_as_string);
2989 *ctx = *old; /* physical copy */
2994 #endif /* HAS_KEYWORDS */
2996 /* Word is complete, look at it and update parsing context.
2997 * Normal return is 0. Syntax errors return 1.
2998 * Note: on return, word is reset, but not o_free'd!
3000 static int done_word(o_string *word, struct parse_context *ctx)
3002 struct command *command = ctx->command;
3004 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3005 if (word->length == 0 && !word->has_quoted_part) {
3006 debug_printf_parse("done_word return 0: true null, ignored\n");
3010 if (ctx->pending_redirect) {
3011 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3012 * only if run as "bash", not "sh" */
3013 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3015 * ...the word that follows the redirection operator
3016 * shall be subjected to tilde expansion, parameter expansion,
3017 * command substitution, arithmetic expansion, and quote
3018 * removal. Pathname expansion shall not be performed
3019 * on the word by a non-interactive shell; an interactive
3020 * shell may perform it, but shall do so only when
3021 * the expansion would result in one word."
3023 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3024 /* Cater for >\file case:
3025 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3026 * Same with heredocs:
3027 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3029 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3030 unbackslash(ctx->pending_redirect->rd_filename);
3031 /* Is it <<"HEREDOC"? */
3032 if (word->has_quoted_part) {
3033 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3036 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3037 ctx->pending_redirect = NULL;
3039 /* If this word wasn't an assignment, next ones definitely
3040 * can't be assignments. Even if they look like ones. */
3041 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3042 && word->o_assignment != WORD_IS_KEYWORD
3044 word->o_assignment = NOT_ASSIGNMENT;
3046 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3047 command->assignment_cnt++;
3048 word->o_assignment = MAYBE_ASSIGNMENT;
3052 # if ENABLE_HUSH_CASE
3053 if (ctx->ctx_dsemicolon
3054 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3056 /* already done when ctx_dsemicolon was set to 1: */
3057 /* ctx->ctx_res_w = RES_MATCH; */
3058 ctx->ctx_dsemicolon = 0;
3061 if (!command->argv /* if it's the first word... */
3062 # if ENABLE_HUSH_LOOPS
3063 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3064 && ctx->ctx_res_w != RES_IN
3066 # if ENABLE_HUSH_CASE
3067 && ctx->ctx_res_w != RES_CASE
3070 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
3071 if (reserved_word(word, ctx)) {
3072 o_reset_to_empty_unquoted(word);
3073 debug_printf_parse("done_word return %d\n",
3074 (ctx->ctx_res_w == RES_SNTX));
3075 return (ctx->ctx_res_w == RES_SNTX);
3077 # if ENABLE_HUSH_BASH_COMPAT
3078 if (strcmp(word->data, "[[") == 0) {
3079 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3085 if (command->group) {
3086 /* "{ echo foo; } echo bar" - bad */
3087 syntax_error_at(word->data);
3088 debug_printf_parse("done_word return 1: syntax error, "
3089 "groups and arglists don't mix\n");
3092 if (word->has_quoted_part
3093 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3094 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3095 /* (otherwise it's known to be not empty and is already safe) */
3097 /* exclude "$@" - it can expand to no word despite "" */
3098 char *p = word->data;
3099 while (p[0] == SPECIAL_VAR_SYMBOL
3100 && (p[1] & 0x7f) == '@'
3101 && p[2] == SPECIAL_VAR_SYMBOL
3105 if (p == word->data || p[0] != '\0') {
3106 /* saw no "$@", or not only "$@" but some
3107 * real text is there too */
3108 /* insert "empty variable" reference, this makes
3109 * e.g. "", $empty"" etc to not disappear */
3110 o_addchr(word, SPECIAL_VAR_SYMBOL);
3111 o_addchr(word, SPECIAL_VAR_SYMBOL);
3114 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3115 debug_print_strings("word appended to argv", command->argv);
3118 #if ENABLE_HUSH_LOOPS
3119 if (ctx->ctx_res_w == RES_FOR) {
3120 if (word->has_quoted_part
3121 || !is_well_formed_var_name(command->argv[0], '\0')
3123 /* bash says just "not a valid identifier" */
3124 syntax_error("not a valid identifier in for");
3127 /* Force FOR to have just one word (variable name) */
3128 /* NB: basically, this makes hush see "for v in ..."
3129 * syntax as if it is "for v; in ...". FOR and IN become
3130 * two pipe structs in parse tree. */
3131 done_pipe(ctx, PIPE_SEQ);
3134 #if ENABLE_HUSH_CASE
3135 /* Force CASE to have just one word */
3136 if (ctx->ctx_res_w == RES_CASE) {
3137 done_pipe(ctx, PIPE_SEQ);
3141 o_reset_to_empty_unquoted(word);
3143 debug_printf_parse("done_word return 0\n");
3148 /* Peek ahead in the input to find out if we have a "&n" construct,
3149 * as in "2>&1", that represents duplicating a file descriptor.
3151 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3152 * REDIRFD_SYNTAX_ERR if syntax error,
3153 * REDIRFD_TO_FILE if no & was seen,
3154 * or the number found.
3157 #define parse_redir_right_fd(as_string, input) \
3158 parse_redir_right_fd(input)
3160 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3166 return REDIRFD_TO_FILE;
3168 ch = i_getch(input); /* get the & */
3169 nommu_addchr(as_string, ch);
3172 ch = i_getch(input);
3173 nommu_addchr(as_string, ch);
3174 return REDIRFD_CLOSE;
3178 while (ch != EOF && isdigit(ch)) {
3179 d = d*10 + (ch-'0');
3181 ch = i_getch(input);
3182 nommu_addchr(as_string, ch);
3187 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3189 bb_error_msg("ambiguous redirect");
3190 return REDIRFD_SYNTAX_ERR;
3193 /* Return code is 0 normal, 1 if a syntax error is detected
3195 static int parse_redirect(struct parse_context *ctx,
3198 struct in_str *input)
3200 struct command *command = ctx->command;
3201 struct redir_struct *redir;
3202 struct redir_struct **redirp;
3205 dup_num = REDIRFD_TO_FILE;
3206 if (style != REDIRECT_HEREDOC) {
3207 /* Check for a '>&1' type redirect */
3208 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3209 if (dup_num == REDIRFD_SYNTAX_ERR)
3212 int ch = i_peek(input);
3213 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3214 if (dup_num) { /* <<-... */
3215 ch = i_getch(input);
3216 nommu_addchr(&ctx->as_string, ch);
3221 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3222 int ch = i_peek(input);
3224 /* >|FILE redirect ("clobbering" >).
3225 * Since we do not support "set -o noclobber" yet,
3226 * >| and > are the same for now. Just eat |.
3228 ch = i_getch(input);
3229 nommu_addchr(&ctx->as_string, ch);
3233 /* Create a new redir_struct and append it to the linked list */
3234 redirp = &command->redirects;
3235 while ((redir = *redirp) != NULL) {
3236 redirp = &(redir->next);
3238 *redirp = redir = xzalloc(sizeof(*redir));
3239 /* redir->next = NULL; */
3240 /* redir->rd_filename = NULL; */
3241 redir->rd_type = style;
3242 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3244 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3245 redir_table[style].descrip);
3247 redir->rd_dup = dup_num;
3248 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3249 /* Erik had a check here that the file descriptor in question
3250 * is legit; I postpone that to "run time"
3251 * A "-" representation of "close me" shows up as a -3 here */
3252 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3253 redir->rd_fd, redir->rd_dup);
3255 /* Set ctx->pending_redirect, so we know what to do at the
3256 * end of the next parsed word. */
3257 ctx->pending_redirect = redir;
3262 /* If a redirect is immediately preceded by a number, that number is
3263 * supposed to tell which file descriptor to redirect. This routine
3264 * looks for such preceding numbers. In an ideal world this routine
3265 * needs to handle all the following classes of redirects...
3266 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3267 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3268 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3269 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3271 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3273 * ... If n is quoted, the number shall not be recognized as part of
3274 * the redirection expression. For example:
3276 * writes the character 2 into file a"
3277 * We are getting it right by setting ->has_quoted_part on any \<char>
3279 * A -1 return means no valid number was found,
3280 * the caller should use the appropriate default for this redirection.
3282 static int redirect_opt_num(o_string *o)
3286 if (o->data == NULL)
3288 num = bb_strtou(o->data, NULL, 10);
3289 if (errno || num < 0)
3291 o_reset_to_empty_unquoted(o);
3296 #define fetch_till_str(as_string, input, word, skip_tabs) \
3297 fetch_till_str(input, word, skip_tabs)
3299 static char *fetch_till_str(o_string *as_string,
3300 struct in_str *input,
3304 o_string heredoc = NULL_O_STRING;
3306 int prev = 0; /* not \ */
3311 ch = i_getch(input);
3313 nommu_addchr(as_string, ch);
3314 if ((ch == '\n' || ch == EOF)
3315 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3317 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3318 heredoc.data[past_EOL] = '\0';
3319 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3320 return heredoc.data;
3322 while (ch == '\n') {
3323 o_addchr(&heredoc, ch);
3326 past_EOL = heredoc.length;
3328 ch = i_getch(input);
3330 nommu_addchr(as_string, ch);
3331 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3335 o_free_unsafe(&heredoc);
3338 o_addchr(&heredoc, ch);
3339 nommu_addchr(as_string, ch);
3340 if (prev == '\\' && ch == '\\')
3341 /* Correctly handle foo\\<eol> (not a line cont.) */
3342 prev = 0; /* not \ */
3348 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3349 * and load them all. There should be exactly heredoc_cnt of them.
3351 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3353 struct pipe *pi = ctx->list_head;
3355 while (pi && heredoc_cnt) {
3357 struct command *cmd = pi->cmds;
3359 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3361 cmd->argv ? cmd->argv[0] : "NONE");
3362 for (i = 0; i < pi->num_cmds; i++) {
3363 struct redir_struct *redir = cmd->redirects;
3365 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3366 i, cmd->argv ? cmd->argv[0] : "NONE");
3368 if (redir->rd_type == REDIRECT_HEREDOC) {
3371 redir->rd_type = REDIRECT_HEREDOC2;
3372 /* redir->rd_dup is (ab)used to indicate <<- */
3373 p = fetch_till_str(&ctx->as_string, input,
3374 redir->rd_filename, redir->rd_dup);
3376 syntax_error("unexpected EOF in here document");
3379 free(redir->rd_filename);
3380 redir->rd_filename = p;
3383 redir = redir->next;
3390 /* Should be 0. If it isn't, it's a parse error */
3392 bb_error_msg_and_die("heredoc BUG 2");
3398 static int run_list(struct pipe *pi);
3400 #define parse_stream(pstring, input, end_trigger) \
3401 parse_stream(input, end_trigger)
3403 static struct pipe *parse_stream(char **pstring,
3404 struct in_str *input,
3408 #if !ENABLE_HUSH_FUNCTIONS
3409 #define parse_group(dest, ctx, input, ch) \
3410 parse_group(ctx, input, ch)
3412 static int parse_group(o_string *dest, struct parse_context *ctx,
3413 struct in_str *input, int ch)
3415 /* dest contains characters seen prior to ( or {.
3416 * Typically it's empty, but for function defs,
3417 * it contains function name (without '()'). */
3418 struct pipe *pipe_list;
3420 struct command *command = ctx->command;
3422 debug_printf_parse("parse_group entered\n");
3423 #if ENABLE_HUSH_FUNCTIONS
3424 if (ch == '(' && !dest->has_quoted_part) {
3426 if (done_word(dest, ctx))
3429 goto skip; /* (... */
3430 if (command->argv[1]) { /* word word ... (... */
3431 syntax_error_unexpected_ch('(');
3434 /* it is "word(..." or "word (..." */
3436 ch = i_getch(input);
3437 while (ch == ' ' || ch == '\t');
3439 syntax_error_unexpected_ch(ch);
3442 nommu_addchr(&ctx->as_string, ch);
3444 ch = i_getch(input);
3445 while (ch == ' ' || ch == '\t' || ch == '\n');
3447 syntax_error_unexpected_ch(ch);
3450 nommu_addchr(&ctx->as_string, ch);
3451 command->cmd_type = CMD_FUNCDEF;
3456 #if 0 /* Prevented by caller */
3457 if (command->argv /* word [word]{... */
3458 || dest->length /* word{... */
3459 || dest->has_quoted_part /* ""{... */
3462 debug_printf_parse("parse_group return 1: "
3463 "syntax error, groups and arglists don't mix\n");
3468 #if ENABLE_HUSH_FUNCTIONS
3474 command->cmd_type = CMD_SUBSHELL;
3476 /* bash does not allow "{echo...", requires whitespace */
3477 ch = i_getch(input);
3478 if (ch != ' ' && ch != '\t' && ch != '\n') {
3479 syntax_error_unexpected_ch(ch);
3482 nommu_addchr(&ctx->as_string, ch);
3487 # define as_string NULL
3489 char *as_string = NULL;
3491 pipe_list = parse_stream(&as_string, input, endch);
3494 o_addstr(&ctx->as_string, as_string);
3496 /* empty ()/{} or parse error? */
3497 if (!pipe_list || pipe_list == ERR_PTR) {
3498 /* parse_stream already emitted error msg */
3501 debug_printf_parse("parse_group return 1: "
3502 "parse_stream returned %p\n", pipe_list);
3505 command->group = pipe_list;
3507 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3508 command->group_as_string = as_string;
3509 debug_printf_parse("end of group, remembering as:'%s'\n",
3510 command->group_as_string);
3514 debug_printf_parse("parse_group return 0\n");
3516 /* command remains "open", available for possible redirects */
3519 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3520 /* Subroutines for copying $(...) and `...` things */
3521 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3523 static void add_till_single_quote(o_string *dest, struct in_str *input)
3526 int ch = i_getch(input);
3528 syntax_error_unterm_ch('\'');
3529 /*xfunc_die(); - redundant */
3536 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3537 static void add_till_double_quote(o_string *dest, struct in_str *input)
3540 int ch = i_getch(input);
3542 syntax_error_unterm_ch('"');
3543 /*xfunc_die(); - redundant */
3547 if (ch == '\\') { /* \x. Copy both chars. */
3549 ch = i_getch(input);
3553 add_till_backquote(dest, input, /*in_dquote:*/ 1);
3557 //if (ch == '$') ...
3560 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3562 * "Within the backquoted style of command substitution, backslash
3563 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3564 * The search for the matching backquote shall be satisfied by the first
3565 * backquote found without a preceding backslash; during this search,
3566 * if a non-escaped backquote is encountered within a shell comment,
3567 * a here-document, an embedded command substitution of the $(command)
3568 * form, or a quoted string, undefined results occur. A single-quoted
3569 * or double-quoted string that begins, but does not end, within the
3570 * "`...`" sequence produces undefined results."
3572 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3574 static void add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3577 int ch = i_getch(input);
3581 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3582 ch = i_getch(input);
3586 && (!in_dquote || ch != '"')
3588 o_addchr(dest, '\\');
3592 syntax_error_unterm_ch('`');
3593 /*xfunc_die(); - redundant */
3598 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3599 * quoting and nested ()s.
3600 * "With the $(command) style of command substitution, all characters
3601 * following the open parenthesis to the matching closing parenthesis
3602 * constitute the command. Any valid shell script can be used for command,
3603 * except a script consisting solely of redirections which produces
3604 * unspecified results."
3606 * echo $(echo '(TEST)' BEST) (TEST) BEST
3607 * echo $(echo 'TEST)' BEST) TEST) BEST
3608 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3610 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3611 * can contain arbitrary constructs, just like $(cmd).
3612 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3613 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3615 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3616 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3619 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3620 # if ENABLE_HUSH_BASH_COMPAT
3621 char end_char2 = end_ch >> 8;
3623 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3626 ch = i_getch(input);
3628 syntax_error_unterm_ch(end_ch);
3629 /*xfunc_die(); - redundant */
3631 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3634 /* we look for closing )) of $((EXPR)) */
3635 if (i_peek(input) == end_ch) {
3636 i_getch(input); /* eat second ')' */
3641 if (ch == '(' || ch == '{') {
3642 ch = (ch == '(' ? ')' : '}');
3643 add_till_closing_bracket(dest, input, ch);
3648 add_till_single_quote(dest, input);
3653 add_till_double_quote(dest, input);
3658 add_till_backquote(dest, input, /*in_dquote:*/ 0);
3663 /* \x. Copy verbatim. Important for \(, \) */
3664 ch = i_getch(input);
3666 syntax_error_unterm_ch(')');
3667 /*xfunc_die(); - redundant */
3675 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3677 /* Return code: 0 for OK, 1 for syntax error */
3679 #define parse_dollar(as_string, dest, input, quote_mask) \
3680 parse_dollar(dest, input, quote_mask)
3681 #define as_string NULL
3683 static int parse_dollar(o_string *as_string,
3685 struct in_str *input, unsigned char quote_mask)
3687 int ch = i_peek(input); /* first character after the $ */
3689 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3691 ch = i_getch(input);
3692 nommu_addchr(as_string, ch);
3694 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3696 debug_printf_parse(": '%c'\n", ch);
3697 o_addchr(dest, ch | quote_mask);
3700 if (!isalnum(ch) && ch != '_')
3702 ch = i_getch(input);
3703 nommu_addchr(as_string, ch);
3705 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3706 } else if (isdigit(ch)) {
3708 ch = i_getch(input);
3709 nommu_addchr(as_string, ch);
3710 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3711 debug_printf_parse(": '%c'\n", ch);
3712 o_addchr(dest, ch | quote_mask);
3713 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3714 } else switch (ch) {
3716 case '!': /* last bg pid */
3717 case '?': /* last exit code */
3718 case '#': /* number of args */
3719 case '*': /* args */
3720 case '@': /* args */
3721 goto make_one_char_var;
3723 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3725 ch = i_getch(input); /* eat '{' */
3726 nommu_addchr(as_string, ch);
3728 ch = i_getch(input); /* first char after '{' */
3729 /* It should be ${?}, or ${#var},
3730 * or even ${?+subst} - operator acting on a special variable,
3731 * or the beginning of variable name.
3734 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3737 syntax_error_unterm_str("${name}");
3738 debug_printf_parse("parse_dollar return 1: unterminated ${name}\n");
3741 nommu_addchr(as_string, ch);
3744 /* It's possible to just call add_till_closing_bracket() at this point.
3745 * However, this regresses some of our testsuite cases
3746 * which check invalid constructs like ${%}.
3747 * Oh well... let's check that the var name part is fine... */
3753 debug_printf_parse(": '%c'\n", ch);
3755 ch = i_getch(input);
3756 nommu_addchr(as_string, ch);
3760 if (!isalnum(ch) && ch != '_') {
3762 unsigned char last_ch;
3763 /* handle parameter expansions
3764 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3766 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3767 goto bad_dollar_syntax;
3769 /* Eat everything until closing '}' (or ':') */
3771 if (ENABLE_HUSH_BASH_COMPAT
3773 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3775 /* It's ${var:N[:M]} thing */
3776 end_ch = '}' * 0x100 + ':';
3778 if (ENABLE_HUSH_BASH_COMPAT
3781 /* It's ${var/[/]pattern[/repl]} thing */
3782 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3784 nommu_addchr(as_string, '/');
3787 end_ch = '}' * 0x100 + '/';
3793 #if ENABLE_HUSH_DOLLAR_OPS
3794 last_ch = add_till_closing_bracket(dest, input, end_ch);
3796 #error Simple code to only allow ${var} is not implemented
3799 o_addstr(as_string, dest->data + pos);
3800 o_addchr(as_string, last_ch);
3803 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3804 /* close the first block: */
3805 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3806 /* while parsing N from ${var:N[:M]}
3807 * or pattern from ${var/[/]pattern[/repl]} */
3808 if ((end_ch & 0xff) == last_ch) {
3809 /* got ':' or '/'- parse the rest */
3814 if (end_ch == '}' * 0x100 + ':') {
3815 /* it's ${var:N} - emulate :999999999 */
3816 o_addstr(dest, "999999999");
3817 } /* else: it's ${var/[/]pattern} */
3822 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3825 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3829 ch = i_getch(input);
3830 nommu_addchr(as_string, ch);
3831 # if ENABLE_SH_MATH_SUPPORT
3832 if (i_peek(input) == '(') {
3833 ch = i_getch(input);
3834 nommu_addchr(as_string, ch);
3835 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3836 o_addchr(dest, /*quote_mask |*/ '+');
3839 add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG);
3841 o_addstr(as_string, dest->data + pos);
3842 o_addchr(as_string, ')');
3843 o_addchr(as_string, ')');
3845 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3849 # if ENABLE_HUSH_TICK
3850 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3851 o_addchr(dest, quote_mask | '`');
3854 add_till_closing_bracket(dest, input, ')');
3856 o_addstr(as_string, dest->data + pos);
3857 o_addchr(as_string, ')');
3859 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3865 ch = i_getch(input);
3866 nommu_addchr(as_string, ch);
3868 if (isalnum(ch)) { /* it's $_name or $_123 */
3873 /* TODO: $_ and $-: */
3874 /* $_ Shell or shell script name; or last argument of last command
3875 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3876 * but in command's env, set to full pathname used to invoke it */
3877 /* $- Option flags set by set builtin or shell options (-i etc) */
3879 o_addQchr(dest, '$');
3881 debug_printf_parse("parse_dollar return 0\n");
3887 # if ENABLE_HUSH_BASH_COMPAT
3888 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3889 encode_string(dest, input, dquote_end, process_bkslash)
3891 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
3892 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3893 encode_string(dest, input, dquote_end)
3895 #define as_string NULL
3899 # if ENABLE_HUSH_BASH_COMPAT
3900 /* all parameters are needed, no macro tricks */
3902 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3903 encode_string(as_string, dest, input, dquote_end)
3906 static int encode_string(o_string *as_string,
3908 struct in_str *input,
3910 int process_bkslash)
3912 #if !ENABLE_HUSH_BASH_COMPAT
3913 const int process_bkslash = 1;
3919 ch = i_getch(input);
3921 nommu_addchr(as_string, ch);
3922 if (ch == dquote_end) { /* may be only '"' or EOF */
3923 debug_printf_parse("encode_string return 0\n");
3926 /* note: can't move it above ch == dquote_end check! */
3928 syntax_error_unterm_ch('"');
3929 /*xfunc_die(); - redundant */
3933 next = i_peek(input);
3935 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3936 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3937 if (process_bkslash && ch == '\\') {
3939 syntax_error("\\<eof>");
3943 * "The backslash retains its special meaning [in "..."]
3944 * only when followed by one of the following characters:
3945 * $, `, ", \, or <newline>. A double quote may be quoted
3946 * within double quotes by preceding it with a backslash."
3947 * NB: in (unquoted) heredoc, above does not apply to ",
3948 * therefore we check for it by "next == dquote_end" cond.
3950 if (next == dquote_end || strchr("$`\\\n", next)) {
3951 ch = i_getch(input); /* eat next */
3953 goto again; /* skip \<newline> */
3954 } /* else: ch remains == '\\', and we double it below: */
3955 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
3956 nommu_addchr(as_string, ch);
3960 if (parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80) != 0) {
3961 debug_printf_parse("encode_string return 1: "
3962 "parse_dollar returned non-0\n");
3967 #if ENABLE_HUSH_TICK
3969 //unsigned pos = dest->length;
3970 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3971 o_addchr(dest, 0x80 | '`');
3972 add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"');
3973 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3974 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
3978 o_addQchr(dest, ch);
3984 * Scan input until EOF or end_trigger char.
3985 * Return a list of pipes to execute, or NULL on EOF
3986 * or if end_trigger character is met.
3987 * On syntax error, exit is shell is not interactive,
3988 * reset parsing machinery and start parsing anew,
3989 * or return ERR_PTR.
3991 static struct pipe *parse_stream(char **pstring,
3992 struct in_str *input,
3995 struct parse_context ctx;
3996 o_string dest = NULL_O_STRING;
3999 /* Single-quote triggers a bypass of the main loop until its mate is
4000 * found. When recursing, quote state is passed in via dest->o_expflags.
4002 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4003 end_trigger ? end_trigger : 'X');
4006 /* If very first arg is "" or '', dest.data may end up NULL.
4007 * Preventing this: */
4008 o_addchr(&dest, '\0');
4011 /* We used to separate words on $IFS here. This was wrong.
4012 * $IFS is used only for word splitting when $var is expanded,
4013 * here we should use blank chars as separators, not $IFS
4016 reset: /* we come back here only on syntax errors in interactive shell */
4018 #if ENABLE_HUSH_INTERACTIVE
4019 input->promptmode = 0; /* PS1 */
4021 if (MAYBE_ASSIGNMENT != 0)
4022 dest.o_assignment = MAYBE_ASSIGNMENT;
4023 initialize_context(&ctx);
4026 const char *is_blank;
4027 const char *is_special;
4031 redir_type redir_style;
4033 ch = i_getch(input);
4034 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4035 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4040 syntax_error_unterm_str("here document");
4043 /* end_trigger == '}' case errors out earlier,
4044 * checking only ')' */
4045 if (end_trigger == ')') {
4046 syntax_error_unterm_ch('('); /* exits */
4047 /* goto parse_error; */
4050 if (done_word(&dest, &ctx)) {
4054 done_pipe(&ctx, PIPE_SEQ);
4056 /* If we got nothing... */
4057 /* (this makes bare "&" cmd a no-op.
4058 * bash says: "syntax error near unexpected token '&'") */
4059 if (pi->num_cmds == 0
4060 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4066 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4068 *pstring = ctx.as_string.data;
4070 o_free_unsafe(&ctx.as_string);
4073 debug_printf_parse("parse_stream return %p\n", pi);
4076 nommu_addchr(&ctx.as_string, ch);
4080 next = i_peek(input);
4082 is_special = "{}<>;&|()#'" /* special outside of "str" */
4083 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4084 /* Are { and } special here? */
4085 if (ctx.command->argv /* word [word]{... - non-special */
4086 || dest.length /* word{... - non-special */
4087 || dest.has_quoted_part /* ""{... - non-special */
4088 || (next != ';' /* }; - special */
4089 && next != ')' /* }) - special */
4090 && next != '&' /* }& and }&& ... - special */
4091 && next != '|' /* }|| ... - special */
4092 && !strchr(defifs, next) /* {word - non-special */
4095 /* They are not special, skip "{}" */
4098 is_special = strchr(is_special, ch);
4099 is_blank = strchr(defifs, ch);
4101 if (!is_special && !is_blank) { /* ordinary char */
4103 o_addQchr(&dest, ch);
4104 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4105 || dest.o_assignment == WORD_IS_KEYWORD)
4107 && is_well_formed_var_name(dest.data, '=')
4109 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4115 if (done_word(&dest, &ctx)) {
4119 /* Is this a case when newline is simply ignored?
4121 * "cmd | <newline> cmd ..."
4122 * "case ... in <newline> word) ..."
4124 if (IS_NULL_CMD(ctx.command)
4125 && dest.length == 0 && !dest.has_quoted_part
4129 /* Treat newline as a command separator. */
4130 done_pipe(&ctx, PIPE_SEQ);
4131 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4133 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4138 dest.o_assignment = MAYBE_ASSIGNMENT;
4140 /* note: if (is_blank) continue;
4141 * will still trigger for us */
4145 /* "cmd}" or "cmd }..." without semicolon or &:
4146 * } is an ordinary char in this case, even inside { cmd; }
4147 * Pathological example: { ""}; } should exec "}" cmd
4150 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4151 || dest.length != 0 /* word} */
4152 || dest.has_quoted_part /* ""} */
4156 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4157 goto skip_end_trigger;
4158 /* else: } does terminate a group */
4161 if (end_trigger && end_trigger == ch
4162 && (ch != ';' || heredoc_cnt == 0)
4163 #if ENABLE_HUSH_CASE
4165 || ctx.ctx_res_w != RES_MATCH
4166 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4171 /* This is technically valid:
4172 * { cat <<HERE; }; echo Ok
4176 * but we don't support this.
4177 * We require heredoc to be in enclosing {}/(),
4180 syntax_error_unterm_str("here document");
4183 if (done_word(&dest, &ctx)) {
4186 done_pipe(&ctx, PIPE_SEQ);
4187 dest.o_assignment = MAYBE_ASSIGNMENT;
4188 /* Do we sit outside of any if's, loops or case's? */
4190 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4194 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4196 *pstring = ctx.as_string.data;
4198 o_free_unsafe(&ctx.as_string);
4201 debug_printf_parse("parse_stream return %p: "
4202 "end_trigger char found\n",
4204 return ctx.list_head;
4211 /* Catch <, > before deciding whether this word is
4212 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4215 redir_fd = redirect_opt_num(&dest);
4216 if (done_word(&dest, &ctx)) {
4219 redir_style = REDIRECT_OVERWRITE;
4221 redir_style = REDIRECT_APPEND;
4222 ch = i_getch(input);
4223 nommu_addchr(&ctx.as_string, ch);
4226 else if (next == '(') {
4227 syntax_error(">(process) not supported");
4231 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4233 continue; /* back to top of while (1) */
4235 redir_fd = redirect_opt_num(&dest);
4236 if (done_word(&dest, &ctx)) {
4239 redir_style = REDIRECT_INPUT;
4241 redir_style = REDIRECT_HEREDOC;
4243 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4244 ch = i_getch(input);
4245 nommu_addchr(&ctx.as_string, ch);
4246 } else if (next == '>') {
4247 redir_style = REDIRECT_IO;
4248 ch = i_getch(input);
4249 nommu_addchr(&ctx.as_string, ch);
4252 else if (next == '(') {
4253 syntax_error("<(process) not supported");
4257 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4259 continue; /* back to top of while (1) */
4261 if (dest.length == 0 && !dest.has_quoted_part) {
4262 /* skip "#comment" */
4265 if (ch == EOF || ch == '\n')
4268 /* note: we do not add it to &ctx.as_string */
4270 nommu_addchr(&ctx.as_string, '\n');
4271 continue; /* back to top of while (1) */
4276 /* It's "\<newline>" */
4278 /* Remove trailing '\' from ctx.as_string */
4279 ctx.as_string.data[--ctx.as_string.length] = '\0';
4281 ch = i_getch(input); /* eat it */
4282 continue; /* back to top of while (1) */
4287 if (dest.o_assignment == MAYBE_ASSIGNMENT
4288 /* check that we are not in word in "a=1 2>word b=1": */
4289 && !ctx.pending_redirect
4291 /* ch is a special char and thus this word
4292 * cannot be an assignment */
4293 dest.o_assignment = NOT_ASSIGNMENT;
4296 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4299 case '#': /* non-comment #: "echo a#b" etc */
4300 o_addQchr(&dest, ch);
4304 syntax_error("\\<eof>");
4307 ch = i_getch(input);
4308 /* note: ch != '\n' (that case does not reach this place) */
4309 o_addchr(&dest, '\\');
4310 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4311 o_addchr(&dest, ch);
4312 nommu_addchr(&ctx.as_string, ch);
4313 /* Example: echo Hello \2>file
4314 * we need to know that word 2 is quoted */
4315 dest.has_quoted_part = 1;
4318 if (parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0) != 0) {
4319 debug_printf_parse("parse_stream parse error: "
4320 "parse_dollar returned non-0\n");
4325 dest.has_quoted_part = 1;
4327 ch = i_getch(input);
4329 syntax_error_unterm_ch('\'');
4330 /*xfunc_die(); - redundant */
4332 nommu_addchr(&ctx.as_string, ch);
4335 o_addqchr(&dest, ch);
4339 dest.has_quoted_part = 1;
4340 if (dest.o_assignment == NOT_ASSIGNMENT)
4341 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4342 if (encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4344 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4346 #if ENABLE_HUSH_TICK
4350 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4351 o_addchr(&dest, '`');
4353 add_till_backquote(&dest, input, /*in_dquote:*/ 0);
4355 o_addstr(&ctx.as_string, dest.data + pos);
4356 o_addchr(&ctx.as_string, '`');
4358 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4359 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4364 #if ENABLE_HUSH_CASE
4367 if (done_word(&dest, &ctx)) {
4370 done_pipe(&ctx, PIPE_SEQ);
4371 #if ENABLE_HUSH_CASE
4372 /* Eat multiple semicolons, detect
4373 * whether it means something special */
4378 ch = i_getch(input);
4379 nommu_addchr(&ctx.as_string, ch);
4380 if (ctx.ctx_res_w == RES_CASE_BODY) {
4381 ctx.ctx_dsemicolon = 1;
4382 ctx.ctx_res_w = RES_MATCH;
4388 /* We just finished a cmd. New one may start
4389 * with an assignment */
4390 dest.o_assignment = MAYBE_ASSIGNMENT;
4393 if (done_word(&dest, &ctx)) {
4397 ch = i_getch(input);
4398 nommu_addchr(&ctx.as_string, ch);
4399 done_pipe(&ctx, PIPE_AND);
4401 done_pipe(&ctx, PIPE_BG);
4405 if (done_word(&dest, &ctx)) {
4408 #if ENABLE_HUSH_CASE
4409 if (ctx.ctx_res_w == RES_MATCH)
4410 break; /* we are in case's "word | word)" */
4412 if (next == '|') { /* || */
4413 ch = i_getch(input);
4414 nommu_addchr(&ctx.as_string, ch);
4415 done_pipe(&ctx, PIPE_OR);
4417 /* we could pick up a file descriptor choice here
4418 * with redirect_opt_num(), but bash doesn't do it.
4419 * "echo foo 2| cat" yields "foo 2". */
4422 o_reset_to_empty_unquoted(&ctx.as_string);
4427 #if ENABLE_HUSH_CASE
4428 /* "case... in [(]word)..." - skip '(' */
4429 if (ctx.ctx_res_w == RES_MATCH
4430 && ctx.command->argv == NULL /* not (word|(... */
4431 && dest.length == 0 /* not word(... */
4432 && dest.has_quoted_part == 0 /* not ""(... */
4438 if (parse_group(&dest, &ctx, input, ch) != 0) {
4443 #if ENABLE_HUSH_CASE
4444 if (ctx.ctx_res_w == RES_MATCH)
4448 /* proper use of this character is caught by end_trigger:
4449 * if we see {, we call parse_group(..., end_trigger='}')
4450 * and it will match } earlier (not here). */
4451 syntax_error_unexpected_ch(ch);
4455 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4461 struct parse_context *pctx;
4462 IF_HAS_KEYWORDS(struct parse_context *p2;)
4464 /* Clean up allocated tree.
4465 * Sample for finding leaks on syntax error recovery path.
4466 * Run it from interactive shell, watch pmap `pidof hush`.
4467 * while if false; then false; fi; do break; fi
4468 * Samples to catch leaks at execution:
4469 * while if (true | {true;}); then echo ok; fi; do break; done
4470 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4474 /* Update pipe/command counts,
4475 * otherwise freeing may miss some */
4476 done_pipe(pctx, PIPE_SEQ);
4477 debug_printf_clean("freeing list %p from ctx %p\n",
4478 pctx->list_head, pctx);
4479 debug_print_tree(pctx->list_head, 0);
4480 free_pipe_list(pctx->list_head);
4481 debug_printf_clean("freed list %p\n", pctx->list_head);
4483 o_free_unsafe(&pctx->as_string);
4485 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4489 IF_HAS_KEYWORDS(pctx = p2;)
4490 } while (HAS_KEYWORDS && pctx);
4491 /* Free text, clear all dest fields */
4493 /* If we are not in top-level parse, we return,
4494 * our caller will propagate error.
4496 if (end_trigger != ';') {
4504 /* Discard cached input, force prompt */
4506 IF_HUSH_INTERACTIVE(input->promptme = 1;)
4512 /*** Execution routines ***/
4514 /* Expansion can recurse, need forward decls: */
4515 #if !ENABLE_HUSH_BASH_COMPAT
4516 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4517 #define expand_string_to_string(str, do_unbackslash) \
4518 expand_string_to_string(str)
4520 static char *expand_string_to_string(const char *str, int do_unbackslash);
4521 #if ENABLE_HUSH_TICK
4522 static int process_command_subs(o_string *dest, const char *s);
4525 /* expand_strvec_to_strvec() takes a list of strings, expands
4526 * all variable references within and returns a pointer to
4527 * a list of expanded strings, possibly with larger number
4528 * of strings. (Think VAR="a b"; echo $VAR).
4529 * This new list is allocated as a single malloc block.
4530 * NULL-terminated list of char* pointers is at the beginning of it,
4531 * followed by strings themselves.
4532 * Caller can deallocate entire list by single free(list). */
4534 /* A horde of its helpers come first: */
4536 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4538 while (--len >= 0) {
4541 #if ENABLE_HUSH_BRACE_EXPANSION
4542 if (c == '{' || c == '}') {
4543 /* { -> \{, } -> \} */
4545 /* And now we want to add { or } and continue:
4548 * luckily, just falling throught achieves this.
4554 /* \z -> \\\z; \<eol> -> \\<eol> */
4559 o_addchr(o, *str++);
4565 /* Store given string, finalizing the word and starting new one whenever
4566 * we encounter IFS char(s). This is used for expanding variable values.
4567 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4568 static int expand_on_ifs(o_string *output, int n, const char *str)
4571 int word_len = strcspn(str, G.ifs);
4573 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4574 o_addblock(output, str, word_len);
4576 /* Protect backslashes against globbing up :)
4577 * Example: "v='\*'; echo b$v" prints "b\*"
4578 * (and does not try to glob on "*")
4580 o_addblock_duplicate_backslash(output, str, word_len);
4581 /*/ Why can't we do it easier? */
4582 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4583 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4587 if (!*str) /* EOL - do not finalize word */
4589 o_addchr(output, '\0');
4590 debug_print_list("expand_on_ifs", output, n);
4591 n = o_save_ptr(output, n);
4592 str += strspn(str, G.ifs); /* skip ifs chars */
4594 debug_print_list("expand_on_ifs[1]", output, n);
4598 /* Helper to expand $((...)) and heredoc body. These act as if
4599 * they are in double quotes, with the exception that they are not :).
4600 * Just the rules are similar: "expand only $var and `cmd`"
4602 * Returns malloced string.
4603 * As an optimization, we return NULL if expansion is not needed.
4605 #if !ENABLE_HUSH_BASH_COMPAT
4606 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4607 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4608 encode_then_expand_string(str)
4610 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4613 struct in_str input;
4614 o_string dest = NULL_O_STRING;
4616 if (!strchr(str, '$')
4617 && !strchr(str, '\\')
4618 #if ENABLE_HUSH_TICK
4619 && !strchr(str, '`')
4625 /* We need to expand. Example:
4626 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4628 setup_string_in_str(&input, str);
4629 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4630 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4631 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4632 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4633 o_free_unsafe(&dest);
4637 #if ENABLE_SH_MATH_SUPPORT
4638 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4640 arith_state_t math_state;
4644 math_state.lookupvar = get_local_var_value;
4645 math_state.setvar = set_local_var_from_halves;
4646 //math_state.endofname = endofname;
4647 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4648 res = arith(&math_state, exp_str ? exp_str : arg);
4651 *errmsg_p = math_state.errmsg;
4652 if (math_state.errmsg)
4653 die_if_script(math_state.errmsg);
4658 #if ENABLE_HUSH_BASH_COMPAT
4659 /* ${var/[/]pattern[/repl]} helpers */
4660 static char *strstr_pattern(char *val, const char *pattern, int *size)
4663 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4664 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4671 /* Optimization: if "*pat" did not match the start of "string",
4672 * we know that "tring", "ring" etc will not match too:
4674 if (pattern[0] == '*')
4679 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4681 char *result = NULL;
4682 unsigned res_len = 0;
4683 unsigned repl_len = strlen(repl);
4687 char *s = strstr_pattern(val, pattern, &size);
4691 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4692 memcpy(result + res_len, val, s - val);
4694 strcpy(result + res_len, repl);
4695 res_len += repl_len;
4696 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4702 if (val[0] && result) {
4703 result = xrealloc(result, res_len + strlen(val) + 1);
4704 strcpy(result + res_len, val);
4705 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4707 debug_printf_varexp("result:'%s'\n", result);
4713 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4715 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4717 const char *val = NULL;
4718 char *to_be_freed = NULL;
4723 char exp_save = exp_save; /* for compiler */
4724 char *exp_saveptr; /* points to expansion operator */
4725 char *exp_word = exp_word; /* for compiler */
4728 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4730 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4732 first_char = arg[0] = arg0 & 0x7f;
4735 if (first_char == '#' /* ${#... */
4736 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4738 /* It must be length operator: ${#var} */
4742 /* Maybe handle parameter expansion */
4743 if (exp_saveptr /* if 2nd char is one of expansion operators */
4744 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4746 /* ${?:0}, ${#[:]%0} etc */
4747 exp_saveptr = var + 1;
4749 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4750 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4752 exp_op = exp_save = *exp_saveptr;
4754 exp_word = exp_saveptr + 1;
4755 if (exp_op == ':') {
4756 exp_op = *exp_word++;
4757 //TODO: try ${var:} and ${var:bogus} in non-bash config
4758 if (ENABLE_HUSH_BASH_COMPAT
4759 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4761 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4766 *exp_saveptr = '\0';
4767 } /* else: it's not an expansion op, but bare ${var} */
4770 /* Look up the variable in question */
4771 if (isdigit(var[0])) {
4772 /* parse_dollar should have vetted var for us */
4773 int n = xatoi_positive(var);
4774 if (n < G.global_argc)
4775 val = G.global_argv[n];
4776 /* else val remains NULL: $N with too big N */
4780 val = utoa(G.root_pid);
4782 case '!': /* bg pid */
4783 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4785 case '?': /* exitcode */
4786 val = utoa(G.last_exitcode);
4788 case '#': /* argc */
4789 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4792 val = get_local_var_value(var);
4796 /* Handle any expansions */
4797 if (exp_op == 'L') {
4798 debug_printf_expand("expand: length(%s)=", val);
4799 val = utoa(val ? strlen(val) : 0);
4800 debug_printf_expand("%s\n", val);
4801 } else if (exp_op) {
4802 if (exp_op == '%' || exp_op == '#') {
4803 /* Standard-mandated substring removal ops:
4804 * ${parameter%word} - remove smallest suffix pattern
4805 * ${parameter%%word} - remove largest suffix pattern
4806 * ${parameter#word} - remove smallest prefix pattern
4807 * ${parameter##word} - remove largest prefix pattern
4809 * Word is expanded to produce a glob pattern.
4810 * Then var's value is matched to it and matching part removed.
4812 if (val && val[0]) {
4816 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4817 if (exp_op == *exp_word) /* ## or %% */
4819 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4821 exp_word = exp_exp_word;
4822 /* HACK ALERT. We depend here on the fact that
4823 * G.global_argv and results of utoa and get_local_var_value
4824 * are actually in writable memory:
4825 * scan_and_match momentarily stores NULs there. */
4827 loc = scan_and_match(t, exp_word, scan_flags);
4828 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4829 // exp_op, t, exp_word, loc);
4831 if (loc) { /* match was found */
4832 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4833 val = loc; /* take right part */
4835 val = to_be_freed = xstrndup(val, loc - val); /* left */
4839 #if ENABLE_HUSH_BASH_COMPAT
4840 else if (exp_op == '/' || exp_op == '\\') {
4841 /* It's ${var/[/]pattern[/repl]} thing.
4842 * Note that in encoded form it has TWO parts:
4843 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4844 * and if // is used, it is encoded as \:
4845 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4847 /* Empty variable always gives nothing: */
4848 // "v=''; echo ${v/*/w}" prints "", not "w"
4849 if (val && val[0]) {
4850 /* pattern uses non-standard expansion.
4851 * repl should be unbackslashed and globbed
4852 * by the usual expansion rules:
4854 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4855 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4856 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4857 * v='a bz'; echo ${v/a*z/\z} prints "z"
4858 * (note that a*z _pattern_ is never globbed!)
4860 char *pattern, *repl, *t;
4861 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
4863 pattern = xstrdup(exp_word);
4864 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4865 *p++ = SPECIAL_VAR_SYMBOL;
4867 p = strchr(p, SPECIAL_VAR_SYMBOL);
4869 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4870 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4871 /* HACK ALERT. We depend here on the fact that
4872 * G.global_argv and results of utoa and get_local_var_value
4873 * are actually in writable memory:
4874 * replace_pattern momentarily stores NULs there. */
4876 to_be_freed = replace_pattern(t,
4878 (repl ? repl : exp_word),
4880 if (to_be_freed) /* at least one replace happened */
4887 else if (exp_op == ':') {
4888 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4889 /* It's ${var:N[:M]} bashism.
4890 * Note that in encoded form it has TWO parts:
4891 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4896 beg = expand_and_evaluate_arith(exp_word, &errmsg);
4899 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4900 *p++ = SPECIAL_VAR_SYMBOL;
4902 p = strchr(p, SPECIAL_VAR_SYMBOL);
4904 len = expand_and_evaluate_arith(exp_word, &errmsg);
4907 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4908 if (len >= 0) { /* bash compat: len < 0 is illegal */
4909 if (beg < 0) /* bash compat */
4911 debug_printf_varexp("from val:'%s'\n", val);
4912 if (len == 0 || !val || beg >= strlen(val)) {
4916 /* Paranoia. What if user entered 9999999999999
4917 * which fits in arith_t but not int? */
4920 val = to_be_freed = xstrndup(val + beg, len);
4922 debug_printf_varexp("val:'%s'\n", val);
4926 die_if_script("malformed ${%s:...}", var);
4929 } else { /* one of "-=+?" */
4930 /* Standard-mandated substitution ops:
4931 * ${var?word} - indicate error if unset
4932 * If var is unset, word (or a message indicating it is unset
4933 * if word is null) is written to standard error
4934 * and the shell exits with a non-zero exit status.
4935 * Otherwise, the value of var is substituted.
4936 * ${var-word} - use default value
4937 * If var is unset, word is substituted.
4938 * ${var=word} - assign and use default value
4939 * If var is unset, word is assigned to var.
4940 * In all cases, final value of var is substituted.
4941 * ${var+word} - use alternative value
4942 * If var is unset, null is substituted.
4943 * Otherwise, word is substituted.
4945 * Word is subjected to tilde expansion, parameter expansion,
4946 * command substitution, and arithmetic expansion.
4947 * If word is not needed, it is not expanded.
4949 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4950 * but also treat null var as if it is unset.
4952 int use_word = (!val || ((exp_save == ':') && !val[0]));
4954 use_word = !use_word;
4955 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4956 (exp_save == ':') ? "true" : "false", use_word);
4958 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4960 exp_word = to_be_freed;
4961 if (exp_op == '?') {
4962 /* mimic bash message */
4963 die_if_script("%s: %s",
4965 exp_word[0] ? exp_word : "parameter null or not set"
4967 //TODO: how interactive bash aborts expansion mid-command?
4972 if (exp_op == '=') {
4973 /* ${var=[word]} or ${var:=[word]} */
4974 if (isdigit(var[0]) || var[0] == '#') {
4975 /* mimic bash message */
4976 die_if_script("$%s: cannot assign in this way", var);
4979 char *new_var = xasprintf("%s=%s", var, val);
4980 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
4984 } /* one of "-=+?" */
4986 *exp_saveptr = exp_save;
4992 *to_be_freed_pp = to_be_freed;
4996 /* Expand all variable references in given string, adding words to list[]
4997 * at n, n+1,... positions. Return updated n (so that list[n] is next one
4998 * to be filled). This routine is extremely tricky: has to deal with
4999 * variables/parameters with whitespace, $* and $@, and constructs like
5000 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5001 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5003 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5004 * expansion of right-hand side of assignment == 1-element expand.
5006 char cant_be_null = 0; /* only bit 0x80 matters */
5009 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5010 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5011 debug_print_list("expand_vars_to_list", output, n);
5012 n = o_save_ptr(output, n);
5013 debug_print_list("expand_vars_to_list[0]", output, n);
5015 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5017 char *to_be_freed = NULL;
5018 const char *val = NULL;
5019 #if ENABLE_HUSH_TICK
5020 o_string subst_result = NULL_O_STRING;
5022 #if ENABLE_SH_MATH_SUPPORT
5023 char arith_buf[sizeof(arith_t)*3 + 2];
5025 o_addblock(output, arg, p - arg);
5026 debug_print_list("expand_vars_to_list[1]", output, n);
5028 p = strchr(p, SPECIAL_VAR_SYMBOL);
5030 /* Fetch special var name (if it is indeed one of them)
5031 * and quote bit, force the bit on if singleword expansion -
5032 * important for not getting v=$@ expand to many words. */
5033 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5035 /* Is this variable quoted and thus expansion can't be null?
5036 * "$@" is special. Even if quoted, it can still
5037 * expand to nothing (not even an empty string),
5038 * thus it is excluded. */
5039 if ((first_ch & 0x7f) != '@')
5040 cant_be_null |= first_ch;
5042 switch (first_ch & 0x7f) {
5043 /* Highest bit in first_ch indicates that var is double-quoted */
5047 if (!G.global_argv[1])
5050 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5051 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5052 while (G.global_argv[i]) {
5053 n = expand_on_ifs(output, n, G.global_argv[i]);
5054 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5055 if (G.global_argv[i++][0] && G.global_argv[i]) {
5056 /* this argv[] is not empty and not last:
5057 * put terminating NUL, start new word */
5058 o_addchr(output, '\0');
5059 debug_print_list("expand_vars_to_list[2]", output, n);
5060 n = o_save_ptr(output, n);
5061 debug_print_list("expand_vars_to_list[3]", output, n);
5065 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5066 * and in this case should treat it like '$*' - see 'else...' below */
5067 if (first_ch == ('@'|0x80) /* quoted $@ */
5068 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5071 o_addQstr(output, G.global_argv[i]);
5072 if (++i >= G.global_argc)
5074 o_addchr(output, '\0');
5075 debug_print_list("expand_vars_to_list[4]", output, n);
5076 n = o_save_ptr(output, n);
5078 } else { /* quoted $* (or v="$@" case): add as one word */
5080 o_addQstr(output, G.global_argv[i]);
5081 if (!G.global_argv[++i])
5084 o_addchr(output, G.ifs[0]);
5089 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5090 /* "Empty variable", used to make "" etc to not disappear */
5092 cant_be_null = 0x80;
5094 #if ENABLE_HUSH_TICK
5095 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5096 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5098 /* Can't just stuff it into output o_string,
5099 * expanded result may need to be globbed
5100 * and $IFS-splitted */
5101 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5102 G.last_exitcode = process_command_subs(&subst_result, arg);
5103 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5104 val = subst_result.data;
5107 #if ENABLE_SH_MATH_SUPPORT
5108 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5111 arg++; /* skip '+' */
5112 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5113 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5114 res = expand_and_evaluate_arith(arg, NULL);
5115 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5116 sprintf(arith_buf, ARITH_FMT, res);
5122 val = expand_one_var(&to_be_freed, arg, &p);
5123 IF_HUSH_TICK(store_val:)
5124 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5125 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5126 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5127 if (val && val[0]) {
5128 n = expand_on_ifs(output, n, val);
5131 } else { /* quoted $VAR, val will be appended below */
5132 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5133 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5137 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5139 if (val && val[0]) {
5140 o_addQstr(output, val);
5144 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5145 * Do the check to avoid writing to a const string. */
5146 if (*p != SPECIAL_VAR_SYMBOL)
5147 *p = SPECIAL_VAR_SYMBOL;
5149 #if ENABLE_HUSH_TICK
5150 o_free(&subst_result);
5153 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5156 debug_print_list("expand_vars_to_list[a]", output, n);
5157 /* this part is literal, and it was already pre-quoted
5158 * if needed (much earlier), do not use o_addQstr here! */
5159 o_addstr_with_NUL(output, arg);
5160 debug_print_list("expand_vars_to_list[b]", output, n);
5161 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5162 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5165 /* allow to reuse list[n] later without re-growth */
5166 output->has_empty_slot = 1;
5168 o_addchr(output, '\0');
5174 static char **expand_variables(char **argv, unsigned expflags)
5178 o_string output = NULL_O_STRING;
5180 output.o_expflags = expflags;
5184 n = expand_vars_to_list(&output, n, *argv);
5187 debug_print_list("expand_variables", &output, n);
5189 /* output.data (malloced in one block) gets returned in "list" */
5190 list = o_finalize_list(&output, n);
5191 debug_print_strings("expand_variables[1]", list);
5195 static char **expand_strvec_to_strvec(char **argv)
5197 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5200 #if ENABLE_HUSH_BASH_COMPAT
5201 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5203 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5207 /* Used for expansion of right hand of assignments,
5208 * $((...)), heredocs, variable espansion parts.
5210 * NB: should NOT do globbing!
5211 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5213 static char *expand_string_to_string(const char *str, int do_unbackslash)
5215 #if !ENABLE_HUSH_BASH_COMPAT
5216 const int do_unbackslash = 1;
5218 char *argv[2], **list;
5220 debug_printf_expand("string_to_string<='%s'\n", str);
5221 /* This is generally an optimization, but it also
5222 * handles "", which otherwise trips over !list[0] check below.
5223 * (is this ever happens that we actually get str="" here?)
5225 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5226 //TODO: Can use on strings with \ too, just unbackslash() them?
5227 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5228 return xstrdup(str);
5231 argv[0] = (char*)str;
5233 list = expand_variables(argv, do_unbackslash
5234 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5235 : EXP_FLAG_SINGLEWORD
5238 if (!list[0] || list[1])
5239 bb_error_msg_and_die("BUG in varexp2");
5240 /* actually, just move string 2*sizeof(char*) bytes back */
5241 overlapping_strcpy((char*)list, list[0]);
5243 unbackslash((char*)list);
5244 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5248 /* Used for "eval" builtin */
5249 static char* expand_strvec_to_string(char **argv)
5253 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5254 /* Convert all NULs to spaces */
5259 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5260 bb_error_msg_and_die("BUG in varexp3");
5261 /* bash uses ' ' regardless of $IFS contents */
5266 overlapping_strcpy((char*)list, list[0]);
5267 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5271 static char **expand_assignments(char **argv, int count)
5276 G.expanded_assignments = p = NULL;
5277 /* Expand assignments into one string each */
5278 for (i = 0; i < count; i++) {
5279 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5281 G.expanded_assignments = NULL;
5288 void re_execute_shell(char ***to_free, const char *s,
5289 char *g_argv0, char **g_argv,
5290 char **builtin_argv) NORETURN;
5292 static void reset_traps_to_defaults(void)
5294 /* This function is always called in a child shell
5295 * after fork (not vfork, NOMMU doesn't use this function).
5300 /* Child shells are not interactive.
5301 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5302 * Testcase: (while :; do :; done) + ^Z should background.
5303 * Same goes for SIGTERM, SIGHUP, SIGINT.
5305 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5306 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5308 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5309 * Stupid. It can be done with *single* &= op, but we can't use
5310 * the fact that G.blocked_set is implemented as a bitmask
5312 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5316 /* Careful. Only if no trap or trap is not "" */
5317 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5318 sigdelset(&G.blocked_set, sig);
5325 /* Our homegrown sig mask is saner to work with :) */
5326 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5328 /* Resetting all traps to default except empty ones */
5329 mask = G.non_DFL_mask;
5330 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5331 if (!G.traps[sig] || !G.traps[sig][0])
5334 G.traps[sig] = NULL;
5335 /* There is no signal for 0 (EXIT) */
5338 /* There was a trap handler, we just removed it.
5339 * But if sig still has non-DFL handling,
5340 * we should not unblock the sig. */
5343 sigdelset(&G.blocked_set, sig);
5345 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5350 static void re_execute_shell(char ***to_free, const char *s,
5351 char *g_argv0, char **g_argv,
5352 char **builtin_argv) NORETURN;
5353 static void re_execute_shell(char ***to_free, const char *s,
5354 char *g_argv0, char **g_argv,
5355 char **builtin_argv)
5357 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5358 /* delims + 2 * (number of bytes in printed hex numbers) */
5359 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5360 char *heredoc_argv[4];
5361 struct variable *cur;
5362 # if ENABLE_HUSH_FUNCTIONS
5363 struct function *funcp;
5367 unsigned long long empty_trap_mask;
5369 if (!g_argv0) { /* heredoc */
5370 argv = heredoc_argv;
5371 argv[0] = (char *) G.argv0_for_re_execing;
5372 argv[1] = (char *) "-<";
5373 argv[2] = (char *) s;
5375 pp = &argv[3]; /* used as pointer to empty environment */
5381 if (pp) while (*pp++)
5384 empty_trap_mask = 0;
5387 for (sig = 1; sig < NSIG; sig++) {
5388 if (G.traps[sig] && !G.traps[sig][0])
5389 empty_trap_mask |= 1LL << sig;
5393 sprintf(param_buf, NOMMU_HACK_FMT
5394 , (unsigned) G.root_pid
5395 , (unsigned) G.root_ppid
5396 , (unsigned) G.last_bg_pid
5397 , (unsigned) G.last_exitcode
5400 IF_HUSH_LOOPS(, G.depth_of_loop)
5402 # undef NOMMU_HACK_FMT
5403 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5404 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5407 for (cur = G.top_var; cur; cur = cur->next) {
5408 if (!cur->flg_export || cur->flg_read_only)
5411 # if ENABLE_HUSH_FUNCTIONS
5412 for (funcp = G.top_func; funcp; funcp = funcp->next)
5418 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5419 *pp++ = (char *) G.argv0_for_re_execing;
5421 for (cur = G.top_var; cur; cur = cur->next) {
5422 if (strcmp(cur->varstr, hush_version_str) == 0)
5424 if (cur->flg_read_only) {
5425 *pp++ = (char *) "-R";
5426 *pp++ = cur->varstr;
5427 } else if (!cur->flg_export) {
5428 *pp++ = (char *) "-V";
5429 *pp++ = cur->varstr;
5432 # if ENABLE_HUSH_FUNCTIONS
5433 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5434 *pp++ = (char *) "-F";
5435 *pp++ = funcp->name;
5436 *pp++ = funcp->body_as_string;
5439 /* We can pass activated traps here. Say, -Tnn:trap_string
5441 * However, POSIX says that subshells reset signals with traps
5443 * I tested bash-3.2 and it not only does that with true subshells
5444 * of the form ( list ), but with any forked children shells.
5445 * I set trap "echo W" WINCH; and then tried:
5447 * { echo 1; sleep 20; echo 2; } &
5448 * while true; do echo 1; sleep 20; echo 2; break; done &
5449 * true | { echo 1; sleep 20; echo 2; } | cat
5451 * In all these cases sending SIGWINCH to the child shell
5452 * did not run the trap. If I add trap "echo V" WINCH;
5453 * _inside_ group (just before echo 1), it works.
5455 * I conclude it means we don't need to pass active traps here.
5456 * Even if we would use signal handlers instead of signal masking
5457 * in order to implement trap handling,
5458 * exec syscall below resets signals to SIG_DFL for us.
5460 *pp++ = (char *) "-c";
5463 while (*++builtin_argv)
5464 *pp++ = *builtin_argv;
5465 *pp++ = (char *) "";
5470 /* *pp = NULL; - is already there */
5474 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5475 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5476 execve(bb_busybox_exec_path, argv, pp);
5477 /* Fallback. Useful for init=/bin/hush usage etc */
5478 if (argv[0][0] == '/')
5479 execve(argv[0], argv, pp);
5480 xfunc_error_retval = 127;
5481 bb_error_msg_and_die("can't re-execute the shell");
5483 #endif /* !BB_MMU */
5486 static int run_and_free_list(struct pipe *pi);
5488 /* Executing from string: eval, sh -c '...'
5489 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5490 * end_trigger controls how often we stop parsing
5491 * NUL: parse all, execute, return
5492 * ';': parse till ';' or newline, execute, repeat till EOF
5494 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5496 /* Why we need empty flag?
5497 * An obscure corner case "false; ``; echo $?":
5498 * empty command in `` should still set $? to 0.
5499 * But we can't just set $? to 0 at the start,
5500 * this breaks "false; echo `echo $?`" case.
5504 struct pipe *pipe_list;
5506 pipe_list = parse_stream(NULL, inp, end_trigger);
5507 if (!pipe_list) { /* EOF */
5509 G.last_exitcode = 0;
5512 debug_print_tree(pipe_list, 0);
5513 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5514 run_and_free_list(pipe_list);
5519 static void parse_and_run_string(const char *s)
5521 struct in_str input;
5522 setup_string_in_str(&input, s);
5523 parse_and_run_stream(&input, '\0');
5526 static void parse_and_run_file(FILE *f)
5528 struct in_str input;
5529 setup_file_in_str(&input, f);
5530 parse_and_run_stream(&input, ';');
5533 #if ENABLE_HUSH_TICK
5534 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5539 char **to_free = NULL;
5543 pid = BB_MMU ? xfork() : xvfork();
5544 if (pid == 0) { /* child */
5545 disable_restore_tty_pgrp_on_exit();
5546 /* Process substitution is not considered to be usual
5547 * 'command execution'.
5548 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5555 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5556 close(channel[0]); /* NB: close _first_, then move fd! */
5557 xmove_fd(channel[1], 1);
5558 /* Prevent it from trying to handle ctrl-z etc */
5559 IF_HUSH_JOB(G.run_list_level = 1;)
5560 /* Awful hack for `trap` or $(trap).
5562 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5563 * contains an example where "trap" is executed in a subshell:
5565 * save_traps=$(trap)
5567 * eval "$save_traps"
5569 * Standard does not say that "trap" in subshell shall print
5570 * parent shell's traps. It only says that its output
5571 * must have suitable form, but then, in the above example
5572 * (which is not supposed to be normative), it implies that.
5574 * bash (and probably other shell) does implement it
5575 * (traps are reset to defaults, but "trap" still shows them),
5576 * but as a result, "trap" logic is hopelessly messed up:
5579 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5580 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5581 * # true | trap <--- trap is in subshell - no output (ditto)
5582 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5583 * trap -- 'echo Ho' SIGWINCH
5584 * # echo `(trap)` <--- in subshell in subshell - output
5585 * trap -- 'echo Ho' SIGWINCH
5586 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5587 * trap -- 'echo Ho' SIGWINCH
5589 * The rules when to forget and when to not forget traps
5590 * get really complex and nonsensical.
5592 * Our solution: ONLY bare $(trap) or `trap` is special.
5594 s = skip_whitespace(s);
5595 if (strncmp(s, "trap", 4) == 0
5596 && skip_whitespace(s + 4)[0] == '\0'
5598 static const char *const argv[] = { NULL, NULL };
5599 builtin_trap((char**)argv);
5600 exit(0); /* not _exit() - we need to fflush */
5603 reset_traps_to_defaults();
5604 parse_and_run_string(s);
5605 _exit(G.last_exitcode);
5607 /* We re-execute after vfork on NOMMU. This makes this script safe:
5608 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5609 * huge=`cat BIG` # was blocking here forever
5612 re_execute_shell(&to_free,
5622 # if ENABLE_HUSH_FAST
5624 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5625 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5626 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5628 enable_restore_tty_pgrp_on_exit();
5633 close_on_exec_on(channel[0]);
5634 return xfdopen_for_read(channel[0]);
5637 /* Return code is exit status of the process that is run. */
5638 static int process_command_subs(o_string *dest, const char *s)
5641 struct in_str pipe_str;
5643 int status, ch, eol_cnt;
5645 fp = generate_stream_from_string(s, &pid);
5647 /* Now send results of command back into original context */
5648 setup_file_in_str(&pipe_str, fp);
5650 while ((ch = i_getch(&pipe_str)) != EOF) {
5656 o_addchr(dest, '\n');
5659 o_addQchr(dest, ch);
5662 debug_printf("done reading from `cmd` pipe, closing it\n");
5664 /* We need to extract exitcode. Test case
5665 * "true; echo `sleep 1; false` $?"
5667 safe_waitpid(pid, &status, 0);
5668 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5669 return WEXITSTATUS(status);
5671 #endif /* ENABLE_HUSH_TICK */
5674 static void setup_heredoc(struct redir_struct *redir)
5676 struct fd_pair pair;
5679 /* the _body_ of heredoc (misleading field name) */
5680 const char *heredoc = redir->rd_filename;
5687 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5688 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5692 len = strlen(heredoc);
5694 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5696 xmove_fd(pair.rd, redir->rd_fd);
5698 /* Try writing without forking. Newer kernels have
5699 * dynamically growing pipes. Must use non-blocking write! */
5702 written = write(pair.wr, heredoc, len);
5713 ndelay_off(pair.wr);
5715 /* Okay, pipe buffer was not big enough */
5716 /* Note: we must not create a stray child (bastard? :)
5717 * for the unsuspecting parent process. Child creates a grandchild
5718 * and exits before parent execs the process which consumes heredoc
5719 * (that exec happens after we return from this function) */
5726 disable_restore_tty_pgrp_on_exit();
5727 pid = BB_MMU ? xfork() : xvfork();
5731 close(redir->rd_fd); /* read side of the pipe */
5733 full_write(pair.wr, heredoc, len); /* may loop or block */
5736 /* Delegate blocking writes to another process */
5737 xmove_fd(pair.wr, STDOUT_FILENO);
5738 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5742 #if ENABLE_HUSH_FAST
5744 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5746 enable_restore_tty_pgrp_on_exit();
5752 wait(NULL); /* wait till child has died */
5755 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5756 * and stderr if they are redirected. */
5757 static int setup_redirects(struct command *prog, int squirrel[])
5760 struct redir_struct *redir;
5762 for (redir = prog->redirects; redir; redir = redir->next) {
5763 if (redir->rd_type == REDIRECT_HEREDOC2) {
5764 /* rd_fd<<HERE case */
5765 if (squirrel && redir->rd_fd < 3
5766 && squirrel[redir->rd_fd] < 0
5768 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5770 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5772 debug_printf_parse("set heredoc '%s'\n",
5773 redir->rd_filename);
5774 setup_heredoc(redir);
5778 if (redir->rd_dup == REDIRFD_TO_FILE) {
5779 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5781 if (redir->rd_filename == NULL) {
5782 /* Something went wrong in the parse.
5783 * Pretend it didn't happen */
5784 bb_error_msg("bug in redirect parse");
5787 mode = redir_table[redir->rd_type].mode;
5788 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5789 openfd = open_or_warn(p, mode);
5792 /* this could get lost if stderr has been redirected, but
5793 * bash and ash both lose it as well (though zsh doesn't!) */
5794 //what the above comment tries to say?
5798 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5799 openfd = redir->rd_dup;
5802 if (openfd != redir->rd_fd) {
5803 if (squirrel && redir->rd_fd < 3
5804 && squirrel[redir->rd_fd] < 0
5806 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5808 if (openfd == REDIRFD_CLOSE) {
5809 /* "n>-" means "close me" */
5810 close(redir->rd_fd);
5812 xdup2(openfd, redir->rd_fd);
5813 if (redir->rd_dup == REDIRFD_TO_FILE)
5821 static void restore_redirects(int squirrel[])
5824 for (i = 0; i < 3; i++) {
5827 /* We simply die on error */
5833 static char *find_in_path(const char *arg)
5836 const char *PATH = get_local_var_value("PATH");
5842 const char *end = strchrnul(PATH, ':');
5843 int sz = end - PATH; /* must be int! */
5847 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5849 /* We have xxx::yyyy in $PATH,
5850 * it means "use current dir" */
5853 if (access(ret, F_OK) == 0)
5866 static const struct built_in_command *find_builtin_helper(const char *name,
5867 const struct built_in_command *x,
5868 const struct built_in_command *end)
5871 if (strcmp(name, x->b_cmd) != 0) {
5875 debug_printf_exec("found builtin '%s'\n", name);
5880 static const struct built_in_command *find_builtin1(const char *name)
5882 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5884 static const struct built_in_command *find_builtin(const char *name)
5886 const struct built_in_command *x = find_builtin1(name);
5889 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5892 #if ENABLE_HUSH_FUNCTIONS
5893 static struct function **find_function_slot(const char *name)
5895 struct function **funcpp = &G.top_func;
5897 if (strcmp(name, (*funcpp)->name) == 0) {
5900 funcpp = &(*funcpp)->next;
5905 static const struct function *find_function(const char *name)
5907 const struct function *funcp = *find_function_slot(name);
5909 debug_printf_exec("found function '%s'\n", name);
5913 /* Note: takes ownership on name ptr */
5914 static struct function *new_function(char *name)
5916 struct function **funcpp = find_function_slot(name);
5917 struct function *funcp = *funcpp;
5919 if (funcp != NULL) {
5920 struct command *cmd = funcp->parent_cmd;
5921 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5923 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5925 /* Note: if !funcp->body, do not free body_as_string!
5926 * This is a special case of "-F name body" function:
5927 * body_as_string was not malloced! */
5929 free_pipe_list(funcp->body);
5931 free(funcp->body_as_string);
5935 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5936 cmd->argv[0] = funcp->name;
5937 cmd->group = funcp->body;
5939 cmd->group_as_string = funcp->body_as_string;
5943 debug_printf_exec("remembering new function '%s'\n", name);
5944 funcp = *funcpp = xzalloc(sizeof(*funcp));
5945 /*funcp->next = NULL;*/
5952 static void unset_func(const char *name)
5954 struct function **funcpp = find_function_slot(name);
5955 struct function *funcp = *funcpp;
5957 if (funcp != NULL) {
5958 debug_printf_exec("freeing function '%s'\n", funcp->name);
5959 *funcpp = funcp->next;
5960 /* funcp is unlinked now, deleting it.
5961 * Note: if !funcp->body, the function was created by
5962 * "-F name body", do not free ->body_as_string
5963 * and ->name as they were not malloced. */
5965 free_pipe_list(funcp->body);
5968 free(funcp->body_as_string);
5976 #define exec_function(to_free, funcp, argv) \
5977 exec_function(funcp, argv)
5979 static void exec_function(char ***to_free,
5980 const struct function *funcp,
5981 char **argv) NORETURN;
5982 static void exec_function(char ***to_free,
5983 const struct function *funcp,
5989 argv[0] = G.global_argv[0];
5990 G.global_argv = argv;
5994 /* On MMU, funcp->body is always non-NULL */
5995 n = run_list(funcp->body);
5999 re_execute_shell(to_free,
6000 funcp->body_as_string,
6007 static int run_function(const struct function *funcp, char **argv)
6013 save_and_replace_G_args(&sv, argv);
6015 /* "we are in function, ok to use return" */
6016 sv_flg = G.flag_return_in_progress;
6017 G.flag_return_in_progress = -1;
6018 # if ENABLE_HUSH_LOCAL
6019 G.func_nest_level++;
6022 /* On MMU, funcp->body is always non-NULL */
6025 /* Function defined by -F */
6026 parse_and_run_string(funcp->body_as_string);
6027 rc = G.last_exitcode;
6031 rc = run_list(funcp->body);
6034 # if ENABLE_HUSH_LOCAL
6036 struct variable *var;
6037 struct variable **var_pp;
6039 var_pp = &G.top_var;
6040 while ((var = *var_pp) != NULL) {
6041 if (var->func_nest_level < G.func_nest_level) {
6042 var_pp = &var->next;
6046 if (var->flg_export)
6047 bb_unsetenv(var->varstr);
6048 /* Remove from global list */
6049 *var_pp = var->next;
6055 G.func_nest_level--;
6058 G.flag_return_in_progress = sv_flg;
6060 restore_G_args(&sv, argv);
6064 #endif /* ENABLE_HUSH_FUNCTIONS */
6068 #define exec_builtin(to_free, x, argv) \
6069 exec_builtin(x, argv)
6071 #define exec_builtin(to_free, x, argv) \
6072 exec_builtin(to_free, argv)
6074 static void exec_builtin(char ***to_free,
6075 const struct built_in_command *x,
6076 char **argv) NORETURN;
6077 static void exec_builtin(char ***to_free,
6078 const struct built_in_command *x,
6082 int rcode = x->b_function(argv);
6086 /* On NOMMU, we must never block!
6087 * Example: { sleep 99 | read line; } & echo Ok
6089 re_execute_shell(to_free,
6098 static void execvp_or_die(char **argv) NORETURN;
6099 static void execvp_or_die(char **argv)
6101 debug_printf_exec("execing '%s'\n", argv[0]);
6102 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6103 execvp(argv[0], argv);
6104 bb_perror_msg("can't execute '%s'", argv[0]);
6105 _exit(127); /* bash compat */
6108 #if ENABLE_HUSH_MODE_X
6109 static void dump_cmd_in_x_mode(char **argv)
6111 if (G_x_mode && argv) {
6112 /* We want to output the line in one write op */
6120 len += strlen(argv[n++]) + 1;
6126 p += sprintf(p, " %s", argv[n++]);
6134 # define dump_cmd_in_x_mode(argv) ((void)0)
6138 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6139 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6140 #define pseudo_exec(nommu_save, command, argv_expanded) \
6141 pseudo_exec(command, argv_expanded)
6144 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6146 * Don't exit() here. If you don't exec, use _exit instead.
6147 * The at_exit handlers apparently confuse the calling process,
6148 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6149 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6150 char **argv, int assignment_cnt,
6151 char **argv_expanded) NORETURN;
6152 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6153 char **argv, int assignment_cnt,
6154 char **argv_expanded)
6158 new_env = expand_assignments(argv, assignment_cnt);
6159 dump_cmd_in_x_mode(new_env);
6161 if (!argv[assignment_cnt]) {
6162 /* Case when we are here: ... | var=val | ...
6163 * (note that we do not exit early, i.e., do not optimize out
6164 * expand_assignments(): think about ... | var=`sleep 1` | ...
6166 free_strings(new_env);
6167 _exit(EXIT_SUCCESS);
6171 set_vars_and_save_old(new_env);
6172 free(new_env); /* optional */
6173 /* we can also destroy set_vars_and_save_old's return value,
6176 nommu_save->new_env = new_env;
6177 nommu_save->old_vars = set_vars_and_save_old(new_env);
6180 if (argv_expanded) {
6181 argv = argv_expanded;
6183 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6185 nommu_save->argv = argv;
6188 dump_cmd_in_x_mode(argv);
6190 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6191 if (strchr(argv[0], '/') != NULL)
6195 /* Check if the command matches any of the builtins.
6196 * Depending on context, this might be redundant. But it's
6197 * easier to waste a few CPU cycles than it is to figure out
6198 * if this is one of those cases.
6201 /* On NOMMU, it is more expensive to re-execute shell
6202 * just in order to run echo or test builtin.
6203 * It's better to skip it here and run corresponding
6204 * non-builtin later. */
6205 const struct built_in_command *x;
6206 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6208 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6211 #if ENABLE_HUSH_FUNCTIONS
6212 /* Check if the command matches any functions */
6214 const struct function *funcp = find_function(argv[0]);
6216 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6221 #if ENABLE_FEATURE_SH_STANDALONE
6222 /* Check if the command matches any busybox applets */
6224 int a = find_applet_by_name(argv[0]);
6226 # if BB_MMU /* see above why on NOMMU it is not allowed */
6227 if (APPLET_IS_NOEXEC(a)) {
6228 debug_printf_exec("running applet '%s'\n", argv[0]);
6229 run_applet_no_and_exit(a, argv);
6232 /* Re-exec ourselves */
6233 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6234 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6235 execv(bb_busybox_exec_path, argv);
6236 /* If they called chroot or otherwise made the binary no longer
6237 * executable, fall through */
6242 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6245 execvp_or_die(argv);
6248 /* Called after [v]fork() in run_pipe
6250 static void pseudo_exec(nommu_save_t *nommu_save,
6251 struct command *command,
6252 char **argv_expanded) NORETURN;
6253 static void pseudo_exec(nommu_save_t *nommu_save,
6254 struct command *command,
6255 char **argv_expanded)
6257 if (command->argv) {
6258 pseudo_exec_argv(nommu_save, command->argv,
6259 command->assignment_cnt, argv_expanded);
6262 if (command->group) {
6263 /* Cases when we are here:
6266 * ... | ( list ) | ...
6267 * ... | { list } | ...
6271 debug_printf_exec("pseudo_exec: run_list\n");
6272 reset_traps_to_defaults();
6273 rcode = run_list(command->group);
6274 /* OK to leak memory by not calling free_pipe_list,
6275 * since this process is about to exit */
6278 re_execute_shell(&nommu_save->argv_from_re_execing,
6279 command->group_as_string,
6286 /* Case when we are here: ... | >file */
6287 debug_printf_exec("pseudo_exec'ed null command\n");
6288 _exit(EXIT_SUCCESS);
6292 static const char *get_cmdtext(struct pipe *pi)
6298 /* This is subtle. ->cmdtext is created only on first backgrounding.
6299 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6300 * On subsequent bg argv is trashed, but we won't use it */
6303 argv = pi->cmds[0].argv;
6304 if (!argv || !argv[0]) {
6305 pi->cmdtext = xzalloc(1);
6311 len += strlen(*argv) + 1;
6315 argv = pi->cmds[0].argv;
6317 len = strlen(*argv);
6318 memcpy(p, *argv, len);
6326 static void insert_bg_job(struct pipe *pi)
6328 struct pipe *job, **jobp;
6331 /* Linear search for the ID of the job to use */
6333 for (job = G.job_list; job; job = job->next)
6334 if (job->jobid >= pi->jobid)
6335 pi->jobid = job->jobid + 1;
6337 /* Add job to the list of running jobs */
6339 while ((job = *jobp) != NULL)
6341 job = *jobp = xmalloc(sizeof(*job));
6343 *job = *pi; /* physical copy */
6345 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6346 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6347 for (i = 0; i < pi->num_cmds; i++) {
6348 job->cmds[i].pid = pi->cmds[i].pid;
6349 /* all other fields are not used and stay zero */
6351 job->cmdtext = xstrdup(get_cmdtext(pi));
6353 if (G_interactive_fd)
6354 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6355 G.last_jobid = job->jobid;
6358 static void remove_bg_job(struct pipe *pi)
6360 struct pipe *prev_pipe;
6362 if (pi == G.job_list) {
6363 G.job_list = pi->next;
6365 prev_pipe = G.job_list;
6366 while (prev_pipe->next != pi)
6367 prev_pipe = prev_pipe->next;
6368 prev_pipe->next = pi->next;
6371 G.last_jobid = G.job_list->jobid;
6376 /* Remove a backgrounded job */
6377 static void delete_finished_bg_job(struct pipe *pi)
6384 /* Check to see if any processes have exited -- if they
6385 * have, figure out why and see if a job has completed */
6386 static int checkjobs(struct pipe *fg_pipe)
6396 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6398 attributes = WUNTRACED;
6399 if (fg_pipe == NULL)
6400 attributes |= WNOHANG;
6403 #if ENABLE_HUSH_FAST
6404 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6405 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6406 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6407 /* There was neither fork nor SIGCHLD since last waitpid */
6408 /* Avoid doing waitpid syscall if possible */
6409 if (!G.we_have_children) {
6413 if (fg_pipe == NULL) { /* is WNOHANG set? */
6414 /* We have children, but they did not exit
6415 * or stop yet (we saw no SIGCHLD) */
6418 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6422 /* Do we do this right?
6423 * bash-3.00# sleep 20 | false
6425 * [3]+ Stopped sleep 20 | false
6426 * bash-3.00# echo $?
6427 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6428 * [hush 1.14.0: yes we do it right]
6435 #if ENABLE_HUSH_FAST
6436 i = G.count_SIGCHLD;
6438 childpid = waitpid(-1, &status, attributes);
6439 if (childpid <= 0) {
6440 if (childpid && errno != ECHILD)
6441 bb_perror_msg("waitpid");
6442 #if ENABLE_HUSH_FAST
6443 else { /* Until next SIGCHLD, waitpid's are useless */
6444 G.we_have_children = (childpid == 0);
6445 G.handled_SIGCHLD = i;
6446 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6451 dead = WIFEXITED(status) || WIFSIGNALED(status);
6454 if (WIFSTOPPED(status))
6455 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6456 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6457 if (WIFSIGNALED(status))
6458 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6459 childpid, WTERMSIG(status), WEXITSTATUS(status));
6460 if (WIFEXITED(status))
6461 debug_printf_jobs("pid %d exited, exitcode %d\n",
6462 childpid, WEXITSTATUS(status));
6464 /* Were we asked to wait for fg pipe? */
6466 i = fg_pipe->num_cmds;
6468 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6469 if (fg_pipe->cmds[i].pid != childpid)
6473 fg_pipe->cmds[i].pid = 0;
6474 fg_pipe->alive_cmds--;
6475 ex = WEXITSTATUS(status);
6476 /* bash prints killer signal's name for *last*
6477 * process in pipe (prints just newline for SIGINT).
6478 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6480 if (WIFSIGNALED(status)) {
6481 int sig = WTERMSIG(status);
6482 if (i == fg_pipe->num_cmds-1)
6483 printf("%s\n", sig == SIGINT ? "" : get_signame(sig));
6484 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6485 * Maybe we need to use sig | 128? */
6488 fg_pipe->cmds[i].cmd_exitcode = ex;
6490 fg_pipe->cmds[i].is_stopped = 1;
6491 fg_pipe->stopped_cmds++;
6493 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6494 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6495 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6496 /* All processes in fg pipe have exited or stopped */
6497 i = fg_pipe->num_cmds;
6499 rcode = fg_pipe->cmds[i].cmd_exitcode;
6500 /* usually last process gives overall exitstatus,
6501 * but with "set -o pipefail", last *failed* process does */
6502 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6505 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6506 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6507 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6508 * and "killall -STOP cat" */
6509 if (G_interactive_fd) {
6511 if (fg_pipe->alive_cmds != 0)
6512 insert_bg_job(fg_pipe);
6516 if (fg_pipe->alive_cmds == 0)
6519 /* There are still running processes in the fg pipe */
6520 goto wait_more; /* do waitpid again */
6522 /* it wasnt fg_pipe, look for process in bg pipes */
6526 /* We asked to wait for bg or orphaned children */
6527 /* No need to remember exitcode in this case */
6528 for (pi = G.job_list; pi; pi = pi->next) {
6529 for (i = 0; i < pi->num_cmds; i++) {
6530 if (pi->cmds[i].pid == childpid)
6531 goto found_pi_and_prognum;
6534 /* Happens when shell is used as init process (init=/bin/sh) */
6535 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6536 continue; /* do waitpid again */
6538 found_pi_and_prognum:
6541 pi->cmds[i].pid = 0;
6543 if (!pi->alive_cmds) {
6544 if (G_interactive_fd)
6545 printf(JOB_STATUS_FORMAT, pi->jobid,
6546 "Done", pi->cmdtext);
6547 delete_finished_bg_job(pi);
6551 pi->cmds[i].is_stopped = 1;
6555 } /* while (waitpid succeeds)... */
6561 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6564 int rcode = checkjobs(fg_pipe);
6565 if (G_saved_tty_pgrp) {
6566 /* Job finished, move the shell to the foreground */
6567 p = getpgrp(); /* our process group id */
6568 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6569 tcsetpgrp(G_interactive_fd, p);
6575 /* Start all the jobs, but don't wait for anything to finish.
6578 * Return code is normally -1, when the caller has to wait for children
6579 * to finish to determine the exit status of the pipe. If the pipe
6580 * is a simple builtin command, however, the action is done by the
6581 * time run_pipe returns, and the exit code is provided as the
6584 * Returns -1 only if started some children. IOW: we have to
6585 * mask out retvals of builtins etc with 0xff!
6587 * The only case when we do not need to [v]fork is when the pipe
6588 * is single, non-backgrounded, non-subshell command. Examples:
6589 * cmd ; ... { list } ; ...
6590 * cmd && ... { list } && ...
6591 * cmd || ... { list } || ...
6592 * If it is, then we can run cmd as a builtin, NOFORK [do we do this?],
6593 * or (if SH_STANDALONE) an applet, and we can run the { list }
6594 * with run_list. If it isn't one of these, we fork and exec cmd.
6596 * Cases when we must fork:
6597 * non-single: cmd | cmd
6598 * backgrounded: cmd & { list } &
6599 * subshell: ( list ) [&]
6601 #if !ENABLE_HUSH_MODE_X
6602 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6603 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6605 static int redirect_and_varexp_helper(char ***new_env_p,
6606 struct variable **old_vars_p,
6607 struct command *command,
6609 char **argv_expanded)
6611 /* setup_redirects acts on file descriptors, not FILEs.
6612 * This is perfect for work that comes after exec().
6613 * Is it really safe for inline use? Experimentally,
6614 * things seem to work. */
6615 int rcode = setup_redirects(command, squirrel);
6617 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6618 *new_env_p = new_env;
6619 dump_cmd_in_x_mode(new_env);
6620 dump_cmd_in_x_mode(argv_expanded);
6622 *old_vars_p = set_vars_and_save_old(new_env);
6626 static NOINLINE int run_pipe(struct pipe *pi)
6628 static const char *const null_ptr = NULL;
6632 struct command *command;
6633 char **argv_expanded;
6635 /* it is not always needed, but we aim to smaller code */
6636 int squirrel[] = { -1, -1, -1 };
6639 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6642 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6643 * Result should be 3 lines: q w e, qwe, q w e
6645 G.ifs = get_local_var_value("IFS");
6649 IF_HUSH_JOB(pi->pgrp = -1;)
6650 pi->stopped_cmds = 0;
6651 command = &pi->cmds[0];
6652 argv_expanded = NULL;
6654 if (pi->num_cmds != 1
6655 || pi->followup == PIPE_BG
6656 || command->cmd_type == CMD_SUBSHELL
6663 debug_printf_exec(": group:%p argv:'%s'\n",
6664 command->group, command->argv ? command->argv[0] : "NONE");
6666 if (command->group) {
6667 #if ENABLE_HUSH_FUNCTIONS
6668 if (command->cmd_type == CMD_FUNCDEF) {
6669 /* "executing" func () { list } */
6670 struct function *funcp;
6672 funcp = new_function(command->argv[0]);
6673 /* funcp->name is already set to argv[0] */
6674 funcp->body = command->group;
6676 funcp->body_as_string = command->group_as_string;
6677 command->group_as_string = NULL;
6679 command->group = NULL;
6680 command->argv[0] = NULL;
6681 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6682 funcp->parent_cmd = command;
6683 command->child_func = funcp;
6685 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6687 return EXIT_SUCCESS;
6691 debug_printf("non-subshell group\n");
6692 rcode = 1; /* exitcode if redir failed */
6693 if (setup_redirects(command, squirrel) == 0) {
6694 debug_printf_exec(": run_list\n");
6695 rcode = run_list(command->group) & 0xff;
6697 restore_redirects(squirrel);
6698 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6700 debug_printf_exec("run_pipe: return %d\n", rcode);
6704 argv = command->argv ? command->argv : (char **) &null_ptr;
6706 const struct built_in_command *x;
6707 #if ENABLE_HUSH_FUNCTIONS
6708 const struct function *funcp;
6712 char **new_env = NULL;
6713 struct variable *old_vars = NULL;
6715 if (argv[command->assignment_cnt] == NULL) {
6716 /* Assignments, but no command */
6717 /* Ensure redirects take effect (that is, create files).
6718 * Try "a=t >file" */
6719 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6720 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6721 /* Set shell variables */
6725 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6726 /* Do we need to flag set_local_var() errors?
6727 * "assignment to readonly var" and "putenv error"
6732 /* Redirect error sets $? to 1. Otherwise,
6733 * if evaluating assignment value set $?, retain it.
6734 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6736 rcode = G.last_exitcode;
6737 /* Exit, _skipping_ variable restoring code: */
6738 goto clean_up_and_ret0;
6740 #else /* Older, bigger, but more correct code */
6742 rcode = setup_redirects(command, squirrel);
6743 restore_redirects(squirrel);
6744 /* Set shell variables */
6746 bb_putchar_stderr('+');
6748 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6750 fprintf(stderr, " %s", p);
6751 debug_printf_exec("set shell var:'%s'->'%s'\n",
6753 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6754 /* Do we need to flag set_local_var() errors?
6755 * "assignment to readonly var" and "putenv error"
6760 bb_putchar_stderr('\n');
6761 /* Redirect error sets $? to 1. Otherwise,
6762 * if evaluating assignment value set $?, retain it.
6763 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6765 rcode = G.last_exitcode;
6766 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6768 debug_printf_exec("run_pipe: return %d\n", rcode);
6773 /* Expand the rest into (possibly) many strings each */
6775 #if ENABLE_HUSH_BASH_COMPAT
6776 else if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6777 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6781 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6784 /* if someone gives us an empty string: `cmd with empty output` */
6785 if (!argv_expanded[0]) {
6786 free(argv_expanded);
6788 return G.last_exitcode;
6791 x = find_builtin(argv_expanded[0]);
6792 #if ENABLE_HUSH_FUNCTIONS
6795 funcp = find_function(argv_expanded[0]);
6799 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6800 debug_printf("exec with redirects only\n");
6801 rcode = setup_redirects(command, NULL);
6802 goto clean_up_and_ret1;
6805 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6808 debug_printf_exec(": builtin '%s' '%s'...\n",
6809 x->b_cmd, argv_expanded[1]);
6810 rcode = x->b_function(argv_expanded) & 0xff;
6813 #if ENABLE_HUSH_FUNCTIONS
6815 # if ENABLE_HUSH_LOCAL
6816 struct variable **sv;
6817 sv = G.shadowed_vars_pp;
6818 G.shadowed_vars_pp = &old_vars;
6820 debug_printf_exec(": function '%s' '%s'...\n",
6821 funcp->name, argv_expanded[1]);
6822 rcode = run_function(funcp, argv_expanded) & 0xff;
6823 # if ENABLE_HUSH_LOCAL
6824 G.shadowed_vars_pp = sv;
6830 unset_vars(new_env);
6832 /* clean_up_and_ret0: */
6833 restore_redirects(squirrel);
6835 free(argv_expanded);
6836 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6838 debug_printf_exec("run_pipe return %d\n", rcode);
6842 if (ENABLE_FEATURE_SH_STANDALONE) {
6843 int n = find_applet_by_name(argv_expanded[0]);
6844 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6845 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6847 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6848 argv_expanded[0], argv_expanded[1]);
6849 rcode = run_nofork_applet(n, argv_expanded);
6851 goto clean_up_and_ret;
6854 /* It is neither builtin nor applet. We must fork. */
6858 /* NB: argv_expanded may already be created, and that
6859 * might include `cmd` runs! Do not rerun it! We *must*
6860 * use argv_expanded if it's non-NULL */
6862 /* Going to fork a child per each pipe member */
6867 while (cmd_no < pi->num_cmds) {
6868 struct fd_pair pipefds;
6870 volatile nommu_save_t nommu_save;
6871 nommu_save.new_env = NULL;
6872 nommu_save.old_vars = NULL;
6873 nommu_save.argv = NULL;
6874 nommu_save.argv_from_re_execing = NULL;
6876 command = &pi->cmds[cmd_no];
6878 if (command->argv) {
6879 debug_printf_exec(": pipe member '%s' '%s'...\n",
6880 command->argv[0], command->argv[1]);
6882 debug_printf_exec(": pipe member with no argv\n");
6885 /* pipes are inserted between pairs of commands */
6888 if (cmd_no < pi->num_cmds)
6889 xpiped_pair(pipefds);
6891 command->pid = BB_MMU ? fork() : vfork();
6892 if (!command->pid) { /* child */
6894 disable_restore_tty_pgrp_on_exit();
6895 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6897 /* Every child adds itself to new process group
6898 * with pgid == pid_of_first_child_in_pipe */
6899 if (G.run_list_level == 1 && G_interactive_fd) {
6902 if (pgrp < 0) /* true for 1st process only */
6904 if (setpgid(0, pgrp) == 0
6905 && pi->followup != PIPE_BG
6906 && G_saved_tty_pgrp /* we have ctty */
6908 /* We do it in *every* child, not just first,
6910 tcsetpgrp(G_interactive_fd, pgrp);
6914 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6915 /* 1st cmd in backgrounded pipe
6916 * should have its stdin /dev/null'ed */
6918 if (open(bb_dev_null, O_RDONLY))
6919 xopen("/", O_RDONLY);
6921 xmove_fd(next_infd, 0);
6923 xmove_fd(pipefds.wr, 1);
6926 /* Like bash, explicit redirects override pipes,
6927 * and the pipe fd is available for dup'ing. */
6928 if (setup_redirects(command, NULL))
6931 /* Restore default handlers just prior to exec */
6932 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
6934 /* Stores to nommu_save list of env vars putenv'ed
6935 * (NOMMU, on MMU we don't need that) */
6936 /* cast away volatility... */
6937 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
6938 /* pseudo_exec() does not return */
6941 /* parent or error */
6942 #if ENABLE_HUSH_FAST
6944 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6946 enable_restore_tty_pgrp_on_exit();
6948 /* Clean up after vforked child */
6949 free(nommu_save.argv);
6950 free(nommu_save.argv_from_re_execing);
6951 unset_vars(nommu_save.new_env);
6952 add_vars(nommu_save.old_vars);
6954 free(argv_expanded);
6955 argv_expanded = NULL;
6956 if (command->pid < 0) { /* [v]fork failed */
6957 /* Clearly indicate, was it fork or vfork */
6958 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
6962 /* Second and next children need to know pid of first one */
6964 pi->pgrp = command->pid;
6970 if (cmd_no < pi->num_cmds)
6972 /* Pass read (output) pipe end to next iteration */
6973 next_infd = pipefds.rd;
6976 if (!pi->alive_cmds) {
6978 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
6983 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
6987 /* NB: called by pseudo_exec, and therefore must not modify any
6988 * global data until exec/_exit (we can be a child after vfork!) */
6989 static int run_list(struct pipe *pi)
6991 #if ENABLE_HUSH_CASE
6992 char *case_word = NULL;
6994 #if ENABLE_HUSH_LOOPS
6995 struct pipe *loop_top = NULL;
6996 char **for_lcur = NULL;
6997 char **for_list = NULL;
6999 smallint last_followup;
7001 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7002 smalluint cond_code = 0;
7004 enum { cond_code = 0 };
7007 smallint rword; /* RES_foo */
7008 smallint last_rword; /* ditto */
7011 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7014 #if ENABLE_HUSH_LOOPS
7015 /* Check syntax for "for" */
7016 for (struct pipe *cpipe = pi; cpipe; cpipe = cpipe->next) {
7017 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7019 /* current word is FOR or IN (BOLD in comments below) */
7020 if (cpipe->next == NULL) {
7021 syntax_error("malformed for");
7023 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7026 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7027 if (cpipe->next->res_word == RES_DO)
7029 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7030 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7031 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7033 syntax_error("malformed for");
7035 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7041 /* Past this point, all code paths should jump to ret: label
7042 * in order to return, no direct "return" statements please.
7043 * This helps to ensure that no memory is leaked. */
7051 last_rword = RES_XXXX;
7053 last_followup = PIPE_SEQ;
7054 rcode = G.last_exitcode;
7056 /* Go through list of pipes, (maybe) executing them. */
7057 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7061 IF_HAS_KEYWORDS(rword = pi->res_word;)
7062 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7063 rword, cond_code, last_rword);
7064 #if ENABLE_HUSH_LOOPS
7065 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7066 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7068 /* start of a loop: remember where loop starts */
7073 /* Still in the same "if...", "then..." or "do..." branch? */
7074 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7075 if ((rcode == 0 && last_followup == PIPE_OR)
7076 || (rcode != 0 && last_followup == PIPE_AND)
7078 /* It is "<true> || CMD" or "<false> && CMD"
7079 * and we should not execute CMD */
7080 debug_printf_exec("skipped cmd because of || or &&\n");
7081 last_followup = pi->followup;
7085 last_followup = pi->followup;
7086 IF_HAS_KEYWORDS(last_rword = rword;)
7089 if (rword == RES_THEN) {
7090 /* if false; then ... fi has exitcode 0! */
7091 G.last_exitcode = rcode = EXIT_SUCCESS;
7092 /* "if <false> THEN cmd": skip cmd */
7096 if (rword == RES_ELSE || rword == RES_ELIF) {
7097 /* "if <true> then ... ELSE/ELIF cmd":
7098 * skip cmd and all following ones */
7103 #if ENABLE_HUSH_LOOPS
7104 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7106 /* first loop through for */
7108 static const char encoded_dollar_at[] ALIGN1 = {
7109 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7110 }; /* encoded representation of "$@" */
7111 static const char *const encoded_dollar_at_argv[] = {
7112 encoded_dollar_at, NULL
7113 }; /* argv list with one element: "$@" */
7116 vals = (char**)encoded_dollar_at_argv;
7117 if (pi->next->res_word == RES_IN) {
7118 /* if no variable values after "in" we skip "for" */
7119 if (!pi->next->cmds[0].argv) {
7120 G.last_exitcode = rcode = EXIT_SUCCESS;
7121 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7124 vals = pi->next->cmds[0].argv;
7125 } /* else: "for var; do..." -> assume "$@" list */
7126 /* create list of variable values */
7127 debug_print_strings("for_list made from", vals);
7128 for_list = expand_strvec_to_strvec(vals);
7129 for_lcur = for_list;
7130 debug_print_strings("for_list", for_list);
7133 /* "for" loop is over, clean up */
7139 /* Insert next value from for_lcur */
7140 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7141 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7144 if (rword == RES_IN) {
7145 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7147 if (rword == RES_DONE) {
7148 continue; /* "done" has no cmds too */
7151 #if ENABLE_HUSH_CASE
7152 if (rword == RES_CASE) {
7153 case_word = expand_strvec_to_string(pi->cmds->argv);
7156 if (rword == RES_MATCH) {
7159 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7161 /* all prev words didn't match, does this one match? */
7162 argv = pi->cmds->argv;
7164 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7165 /* TODO: which FNM_xxx flags to use? */
7166 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7168 if (cond_code == 0) { /* match! we will execute this branch */
7169 free(case_word); /* make future "word)" stop */
7177 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7179 continue; /* not matched yet, skip this pipe */
7182 /* Just pressing <enter> in shell should check for jobs.
7183 * OTOH, in non-interactive shell this is useless
7184 * and only leads to extra job checks */
7185 if (pi->num_cmds == 0) {
7186 if (G_interactive_fd)
7187 goto check_jobs_and_continue;
7191 /* After analyzing all keywords and conditions, we decided
7192 * to execute this pipe. NB: have to do checkjobs(NULL)
7193 * after run_pipe to collect any background children,
7194 * even if list execution is to be stopped. */
7195 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7198 #if ENABLE_HUSH_LOOPS
7199 G.flag_break_continue = 0;
7201 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7203 /* We ran a builtin, function, or group.
7204 * rcode is already known
7205 * and we don't need to wait for anything. */
7206 G.last_exitcode = rcode;
7207 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7208 check_and_run_traps(0);
7209 #if ENABLE_HUSH_LOOPS
7210 /* Was it "break" or "continue"? */
7211 if (G.flag_break_continue) {
7212 smallint fbc = G.flag_break_continue;
7213 /* We might fall into outer *loop*,
7214 * don't want to break it too */
7216 G.depth_break_continue--;
7217 if (G.depth_break_continue == 0)
7218 G.flag_break_continue = 0;
7219 /* else: e.g. "continue 2" should *break* once, *then* continue */
7220 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7221 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7222 goto check_jobs_and_break;
7223 /* "continue": simulate end of loop */
7228 #if ENABLE_HUSH_FUNCTIONS
7229 if (G.flag_return_in_progress == 1) {
7230 /* same as "goto check_jobs_and_break" */
7235 } else if (pi->followup == PIPE_BG) {
7236 /* What does bash do with attempts to background builtins? */
7237 /* even bash 3.2 doesn't do that well with nested bg:
7238 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7239 * I'm NOT treating inner &'s as jobs */
7240 check_and_run_traps(0);
7242 if (G.run_list_level == 1)
7245 /* Last command's pid goes to $! */
7246 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7247 G.last_exitcode = rcode = EXIT_SUCCESS;
7248 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7251 if (G.run_list_level == 1 && G_interactive_fd) {
7252 /* Waits for completion, then fg's main shell */
7253 rcode = checkjobs_and_fg_shell(pi);
7254 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7255 check_and_run_traps(0);
7258 { /* This one just waits for completion */
7259 rcode = checkjobs(pi);
7260 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7261 check_and_run_traps(0);
7263 G.last_exitcode = rcode;
7267 /* Analyze how result affects subsequent commands */
7269 if (rword == RES_IF || rword == RES_ELIF)
7272 #if ENABLE_HUSH_LOOPS
7273 /* Beware of "while false; true; do ..."! */
7274 if (pi->next && pi->next->res_word == RES_DO) {
7275 if (rword == RES_WHILE) {
7277 /* "while false; do...done" - exitcode 0 */
7278 G.last_exitcode = rcode = EXIT_SUCCESS;
7279 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7280 goto check_jobs_and_break;
7283 if (rword == RES_UNTIL) {
7285 debug_printf_exec(": until expr is true: breaking\n");
7286 check_jobs_and_break:
7294 check_jobs_and_continue:
7301 #if ENABLE_HUSH_LOOPS
7306 #if ENABLE_HUSH_CASE
7310 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7314 /* Select which version we will use */
7315 static int run_and_free_list(struct pipe *pi)
7318 debug_printf_exec("run_and_free_list entered\n");
7319 if (!G.o_opt[OPT_O_NOEXEC]) {
7320 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7321 rcode = run_list(pi);
7323 /* free_pipe_list has the side effect of clearing memory.
7324 * In the long run that function can be merged with run_list,
7325 * but doing that now would hobble the debugging effort. */
7327 debug_printf_exec("run_and_free_list return %d\n", rcode);
7332 /* Called a few times only (or even once if "sh -c") */
7333 static void init_sigmasks(void)
7337 sigset_t old_blocked_set;
7339 if (!G.inherited_set_is_saved) {
7340 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7341 G.inherited_set = G.blocked_set;
7343 old_blocked_set = G.blocked_set;
7345 mask = (1 << SIGQUIT);
7346 if (G_interactive_fd) {
7347 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7348 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7349 mask |= SPECIAL_JOB_SIGS;
7351 G.non_DFL_mask = mask;
7356 sigaddset(&G.blocked_set, sig);
7360 sigdelset(&G.blocked_set, SIGCHLD);
7362 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7363 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7365 /* POSIX allows shell to re-enable SIGCHLD
7366 * even if it was SIG_IGN on entry */
7367 #if ENABLE_HUSH_FAST
7368 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7369 if (!G.inherited_set_is_saved)
7370 signal(SIGCHLD, SIGCHLD_handler);
7372 if (!G.inherited_set_is_saved)
7373 signal(SIGCHLD, SIG_DFL);
7376 G.inherited_set_is_saved = 1;
7381 static void maybe_set_to_sigexit(int sig)
7383 void (*handler)(int);
7384 /* non_DFL_mask'ed signals are, well, masked,
7385 * no need to set handler for them.
7387 if (!((G.non_DFL_mask >> sig) & 1)) {
7388 handler = signal(sig, sigexit);
7389 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7390 signal(sig, handler);
7393 /* Set handlers to restore tty pgrp and exit */
7394 static void set_fatal_handlers(void)
7396 /* We _must_ restore tty pgrp on fatal signals */
7398 maybe_set_to_sigexit(SIGILL );
7399 maybe_set_to_sigexit(SIGFPE );
7400 maybe_set_to_sigexit(SIGBUS );
7401 maybe_set_to_sigexit(SIGSEGV);
7402 maybe_set_to_sigexit(SIGTRAP);
7403 } /* else: hush is perfect. what SEGV? */
7404 maybe_set_to_sigexit(SIGABRT);
7405 /* bash 3.2 seems to handle these just like 'fatal' ones */
7406 maybe_set_to_sigexit(SIGPIPE);
7407 maybe_set_to_sigexit(SIGALRM);
7408 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7409 * if we aren't interactive... but in this case
7410 * we never want to restore pgrp on exit, and this fn is not called */
7411 /*maybe_set_to_sigexit(SIGHUP );*/
7412 /*maybe_set_to_sigexit(SIGTERM);*/
7413 /*maybe_set_to_sigexit(SIGINT );*/
7417 static int set_mode(int state, char mode, const char *o_opt)
7422 G.o_opt[OPT_O_NOEXEC] = state;
7425 IF_HUSH_MODE_X(G_x_mode = state;)
7429 /* "set -+o" without parameter.
7430 * in bash, set -o produces this output:
7434 * We always use the second form.
7436 const char *p = o_opt_strings;
7439 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7445 idx = index_in_strings(o_opt_strings, o_opt);
7447 G.o_opt[idx] = state;
7451 return EXIT_FAILURE;
7453 return EXIT_SUCCESS;
7456 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7457 int hush_main(int argc, char **argv)
7460 unsigned builtin_argc;
7462 struct variable *cur_var;
7463 struct variable shell_ver;
7466 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7467 G.last_exitcode = EXIT_SUCCESS;
7469 G.argv0_for_re_execing = argv[0];
7471 /* Deal with HUSH_VERSION */
7472 memset(&shell_ver, 0, sizeof(shell_ver));
7473 shell_ver.flg_export = 1;
7474 shell_ver.flg_read_only = 1;
7475 /* Code which handles ${var<op>...} needs writable values for all variables,
7476 * therefore we xstrdup: */
7477 shell_ver.varstr = xstrdup(hush_version_str),
7478 G.top_var = &shell_ver;
7479 /* Create shell local variables from the values
7480 * currently living in the environment */
7481 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7482 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7483 cur_var = G.top_var;
7486 char *value = strchr(*e, '=');
7487 if (value) { /* paranoia */
7488 cur_var->next = xzalloc(sizeof(*cur_var));
7489 cur_var = cur_var->next;
7490 cur_var->varstr = *e;
7491 cur_var->max_len = strlen(*e);
7492 cur_var->flg_export = 1;
7496 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7497 debug_printf_env("putenv '%s'\n", shell_ver.varstr);
7498 putenv(shell_ver.varstr);
7501 set_pwd_var(/*exp:*/ 1);
7502 /* bash also exports SHLVL and _,
7503 * and sets (but doesn't export) the following variables:
7505 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7506 * BASH_VERSION='3.2.0(1)-release'
7508 * MACHTYPE=i386-pc-linux-gnu
7510 * HOSTNAME=<xxxxxxxxxx>
7511 * PPID=<NNNNN> - we also do it elsewhere
7522 * PIPESTATUS=([0]="0")
7523 * HISTFILE=/<xxx>/.bash_history
7527 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7529 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7539 #if ENABLE_FEATURE_EDITING
7540 G.line_input_state = new_line_input_t(FOR_SHELL);
7541 # if defined MAX_HISTORY && MAX_HISTORY > 0 && ENABLE_HUSH_SAVEHISTORY
7543 const char *hp = get_local_var_value("HISTFILE");
7545 hp = get_local_var_value("HOME");
7547 G.line_input_state->hist_file = concat_path_file(hp, ".hush_history");
7548 //set_local_var(xasprintf("HISTFILE=%s", ...));
7555 G.global_argc = argc;
7556 G.global_argv = argv;
7557 /* Initialize some more globals to non-zero values */
7558 cmdedit_update_prompt();
7560 if (setjmp(die_jmp)) {
7561 /* xfunc has failed! die die die */
7562 /* no EXIT traps, this is an escape hatch! */
7564 hush_exit(xfunc_error_retval);
7567 /* Shell is non-interactive at first. We need to call
7568 * init_sigmasks() if we are going to execute "sh <script>",
7569 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7570 * If we later decide that we are interactive, we run init_sigmasks()
7571 * in order to intercept (more) signals.
7575 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7578 opt = getopt(argc, argv, "+c:xins"
7581 # if ENABLE_HUSH_FUNCTIONS
7591 * sh ... -c 'script'
7592 * sh ... -c 'script' ARG0 [ARG1...]
7593 * On NOMMU, if builtin_argc != 0,
7594 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7595 * "" needs to be replaced with NULL
7596 * and BARGV vector fed to builtin function.
7597 * Note: the form without ARG0 never happens:
7598 * sh ... -c 'builtin' BARGV... ""
7601 G.root_pid = getpid();
7602 G.root_ppid = getppid();
7604 G.global_argv = argv + optind;
7605 G.global_argc = argc - optind;
7607 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7608 const struct built_in_command *x;
7611 x = find_builtin(optarg);
7612 if (x) { /* paranoia */
7613 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7614 G.global_argv += builtin_argc;
7615 G.global_argv[-1] = NULL; /* replace "" */
7616 G.last_exitcode = x->b_function(argv + optind - 1);
7620 if (!G.global_argv[0]) {
7621 /* -c 'script' (no params): prevent empty $0 */
7622 G.global_argv--; /* points to argv[i] of 'script' */
7623 G.global_argv[0] = argv[0];
7625 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7627 parse_and_run_string(optarg);
7630 /* Well, we cannot just declare interactiveness,
7631 * we have to have some stuff (ctty, etc) */
7632 /* G_interactive_fd++; */
7635 /* "-s" means "read from stdin", but this is how we always
7636 * operate, so simply do nothing here. */
7639 case '<': /* "big heredoc" support */
7640 full_write1_str(optarg);
7643 unsigned long long empty_trap_mask;
7645 G.root_pid = bb_strtou(optarg, &optarg, 16);
7647 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7649 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7651 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7653 builtin_argc = bb_strtou(optarg, &optarg, 16);
7655 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7656 if (empty_trap_mask != 0) {
7659 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7660 for (sig = 1; sig < NSIG; sig++) {
7661 if (empty_trap_mask & (1LL << sig)) {
7662 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7663 sigaddset(&G.blocked_set, sig);
7666 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7668 # if ENABLE_HUSH_LOOPS
7670 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7676 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7678 # if ENABLE_HUSH_FUNCTIONS
7680 struct function *funcp = new_function(optarg);
7681 /* funcp->name is already set to optarg */
7682 /* funcp->body is set to NULL. It's a special case. */
7683 funcp->body_as_string = argv[optind];
7691 if (set_mode(1, opt, NULL) == 0) /* no error */
7695 fprintf(stderr, "Usage: sh [FILE]...\n"
7696 " or: sh -c command [args]...\n\n");
7702 } /* option parsing loop */
7705 G.root_pid = getpid();
7706 G.root_ppid = getppid();
7709 /* If we are login shell... */
7710 if (argv[0] && argv[0][0] == '-') {
7712 debug_printf("sourcing /etc/profile\n");
7713 input = fopen_for_read("/etc/profile");
7714 if (input != NULL) {
7715 close_on_exec_on(fileno(input));
7717 parse_and_run_file(input);
7720 /* bash: after sourcing /etc/profile,
7721 * tries to source (in the given order):
7722 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7723 * stopping on first found. --noprofile turns this off.
7724 * bash also sources ~/.bash_logout on exit.
7725 * If called as sh, skips .bash_XXX files.
7732 * "bash <script>" (which is never interactive (unless -i?))
7733 * sources $BASH_ENV here (without scanning $PATH).
7734 * If called as sh, does the same but with $ENV.
7736 debug_printf("running script '%s'\n", argv[optind]);
7737 G.global_argv = argv + optind;
7738 G.global_argc = argc - optind;
7739 input = xfopen_for_read(argv[optind]);
7740 close_on_exec_on(fileno(input));
7742 parse_and_run_file(input);
7743 #if ENABLE_FEATURE_CLEAN_UP
7749 /* Up to here, shell was non-interactive. Now it may become one.
7750 * NB: don't forget to (re)run init_sigmasks() as needed.
7753 /* A shell is interactive if the '-i' flag was given,
7754 * or if all of the following conditions are met:
7756 * no arguments remaining or the -s flag given
7757 * standard input is a terminal
7758 * standard output is a terminal
7759 * Refer to Posix.2, the description of the 'sh' utility.
7762 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7763 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7764 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7765 if (G_saved_tty_pgrp < 0)
7766 G_saved_tty_pgrp = 0;
7768 /* try to dup stdin to high fd#, >= 255 */
7769 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7770 if (G_interactive_fd < 0) {
7771 /* try to dup to any fd */
7772 G_interactive_fd = dup(STDIN_FILENO);
7773 if (G_interactive_fd < 0) {
7775 G_interactive_fd = 0;
7776 G_saved_tty_pgrp = 0;
7779 // TODO: track & disallow any attempts of user
7780 // to (inadvertently) close/redirect G_interactive_fd
7782 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7783 if (G_interactive_fd) {
7784 close_on_exec_on(G_interactive_fd);
7786 if (G_saved_tty_pgrp) {
7787 /* If we were run as 'hush &', sleep until we are
7788 * in the foreground (tty pgrp == our pgrp).
7789 * If we get started under a job aware app (like bash),
7790 * make sure we are now in charge so we don't fight over
7791 * who gets the foreground */
7793 pid_t shell_pgrp = getpgrp();
7794 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7795 if (G_saved_tty_pgrp == shell_pgrp)
7797 /* send TTIN to ourself (should stop us) */
7798 kill(- shell_pgrp, SIGTTIN);
7802 /* Block some signals */
7805 if (G_saved_tty_pgrp) {
7806 /* Set other signals to restore saved_tty_pgrp */
7807 set_fatal_handlers();
7808 /* Put ourselves in our own process group
7809 * (bash, too, does this only if ctty is available) */
7810 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7811 /* Grab control of the terminal */
7812 tcsetpgrp(G_interactive_fd, getpid());
7814 /* -1 is special - makes xfuncs longjmp, not exit
7815 * (we reset die_sleep = 0 whereever we [v]fork) */
7816 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7820 #elif ENABLE_HUSH_INTERACTIVE
7821 /* No job control compiled in, only prompt/line editing */
7822 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7823 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7824 if (G_interactive_fd < 0) {
7825 /* try to dup to any fd */
7826 G_interactive_fd = dup(STDIN_FILENO);
7827 if (G_interactive_fd < 0)
7829 G_interactive_fd = 0;
7832 if (G_interactive_fd) {
7833 close_on_exec_on(G_interactive_fd);
7837 /* We have interactiveness code disabled */
7841 * if interactive but not a login shell, sources ~/.bashrc
7842 * (--norc turns this off, --rcfile <file> overrides)
7845 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7846 /* note: ash and hush share this string */
7847 printf("\n\n%s %s\n"
7848 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7851 "hush - the humble shell"
7855 parse_and_run_file(stdin);
7858 #if ENABLE_FEATURE_CLEAN_UP
7859 if (G.cwd != bb_msg_unknown)
7861 cur_var = G.top_var->next;
7863 struct variable *tmp = cur_var;
7864 if (!cur_var->max_len)
7865 free(cur_var->varstr);
7866 cur_var = cur_var->next;
7870 hush_exit(G.last_exitcode);
7875 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7876 int msh_main(int argc, char **argv)
7878 //bb_error_msg("msh is deprecated, please use hush instead");
7879 return hush_main(argc, argv);
7887 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7892 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7899 return applet_main_func(argc, argv - argc);
7902 static int FAST_FUNC builtin_test(char **argv)
7904 return run_applet_main(argv, test_main);
7907 static int FAST_FUNC builtin_echo(char **argv)
7909 return run_applet_main(argv, echo_main);
7913 static int FAST_FUNC builtin_printf(char **argv)
7915 return run_applet_main(argv, printf_main);
7919 static char **skip_dash_dash(char **argv)
7922 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7927 static int FAST_FUNC builtin_eval(char **argv)
7929 int rcode = EXIT_SUCCESS;
7931 argv = skip_dash_dash(argv);
7933 char *str = expand_strvec_to_string(argv);
7935 * eval "echo Hi; done" ("done" is syntax error):
7936 * "echo Hi" will not execute too.
7938 parse_and_run_string(str);
7940 rcode = G.last_exitcode;
7945 static int FAST_FUNC builtin_cd(char **argv)
7949 argv = skip_dash_dash(argv);
7951 if (newdir == NULL) {
7952 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
7953 * bash says "bash: cd: HOME not set" and does nothing
7956 const char *home = get_local_var_value("HOME");
7957 newdir = home ? home : "/";
7959 if (chdir(newdir)) {
7960 /* Mimic bash message exactly */
7961 bb_perror_msg("cd: %s", newdir);
7962 return EXIT_FAILURE;
7964 /* Read current dir (get_cwd(1) is inside) and set PWD.
7965 * Note: do not enforce exporting. If PWD was unset or unexported,
7966 * set it again, but do not export. bash does the same.
7968 set_pwd_var(/*exp:*/ 0);
7969 return EXIT_SUCCESS;
7972 static int FAST_FUNC builtin_exec(char **argv)
7974 argv = skip_dash_dash(argv);
7975 if (argv[0] == NULL)
7976 return EXIT_SUCCESS; /* bash does this */
7978 /* Careful: we can end up here after [v]fork. Do not restore
7979 * tty pgrp then, only top-level shell process does that */
7980 if (G_saved_tty_pgrp && getpid() == G.root_pid)
7981 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
7983 /* TODO: if exec fails, bash does NOT exit! We do.
7984 * We'll need to undo sigprocmask (it's inside execvp_or_die)
7985 * and tcsetpgrp, and this is inherently racy.
7987 execvp_or_die(argv);
7990 static int FAST_FUNC builtin_exit(char **argv)
7992 debug_printf_exec("%s()\n", __func__);
7994 /* interactive bash:
7995 * # trap "echo EEE" EXIT
7998 * There are stopped jobs.
7999 * (if there are _stopped_ jobs, running ones don't count)
8002 # EEE (then bash exits)
8004 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8007 /* note: EXIT trap is run by hush_exit */
8008 argv = skip_dash_dash(argv);
8009 if (argv[0] == NULL)
8010 hush_exit(G.last_exitcode);
8011 /* mimic bash: exit 123abc == exit 255 + error msg */
8012 xfunc_error_retval = 255;
8013 /* bash: exit -2 == exit 254, no error msg */
8014 hush_exit(xatoi(argv[0]) & 0xff);
8017 static void print_escaped(const char *s)
8022 const char *p = strchrnul(s, '\'');
8023 /* print 'xxxx', possibly just '' */
8024 printf("'%.*s'", (int)(p - s), s);
8029 /* s points to '; print "'''...'''" */
8031 do putchar('\''); while (*++s == '\'');
8036 #if !ENABLE_HUSH_LOCAL
8037 #define helper_export_local(argv, exp, lvl) \
8038 helper_export_local(argv, exp)
8040 static void helper_export_local(char **argv, int exp, int lvl)
8044 char *name_end = strchrnul(name, '=');
8046 /* So far we do not check that name is valid (TODO?) */
8048 if (*name_end == '\0') {
8049 struct variable *var, **vpp;
8051 vpp = get_ptr_to_local_var(name, name_end - name);
8052 var = vpp ? *vpp : NULL;
8054 if (exp == -1) { /* unexporting? */
8055 /* export -n NAME (without =VALUE) */
8057 var->flg_export = 0;
8058 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8060 } /* else: export -n NOT_EXISTING_VAR: no-op */
8063 if (exp == 1) { /* exporting? */
8064 /* export NAME (without =VALUE) */
8066 var->flg_export = 1;
8067 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8068 putenv(var->varstr);
8072 /* Exporting non-existing variable.
8073 * bash does not put it in environment,
8074 * but remembers that it is exported,
8075 * and does put it in env when it is set later.
8076 * We just set it to "" and export. */
8077 /* Or, it's "local NAME" (without =VALUE).
8078 * bash sets the value to "". */
8079 name = xasprintf("%s=", name);
8081 /* (Un)exporting/making local NAME=VALUE */
8082 name = xstrdup(name);
8084 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8088 static int FAST_FUNC builtin_export(char **argv)
8090 unsigned opt_unexport;
8092 #if ENABLE_HUSH_EXPORT_N
8093 /* "!": do not abort on errors */
8094 opt_unexport = getopt32(argv, "!n");
8095 if (opt_unexport == (uint32_t)-1)
8096 return EXIT_FAILURE;
8103 if (argv[0] == NULL) {
8110 /* ash emits: export VAR='VAL'
8111 * bash: declare -x VAR="VAL"
8112 * we follow ash example */
8113 const char *s = *e++;
8114 const char *p = strchr(s, '=');
8116 if (!p) /* wtf? take next variable */
8119 printf("export %.*s", (int)(p - s) + 1, s);
8120 print_escaped(p + 1);
8124 /*fflush_all(); - done after each builtin anyway */
8126 return EXIT_SUCCESS;
8129 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8131 return EXIT_SUCCESS;
8134 #if ENABLE_HUSH_LOCAL
8135 static int FAST_FUNC builtin_local(char **argv)
8137 if (G.func_nest_level == 0) {
8138 bb_error_msg("%s: not in a function", argv[0]);
8139 return EXIT_FAILURE; /* bash compat */
8141 helper_export_local(argv, 0, G.func_nest_level);
8142 return EXIT_SUCCESS;
8146 static int FAST_FUNC builtin_trap(char **argv)
8152 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8157 /* No args: print all trapped */
8158 for (i = 0; i < NSIG; ++i) {
8161 print_escaped(G.traps[i]);
8162 /* note: bash adds "SIG", but only if invoked
8163 * as "bash". If called as "sh", or if set -o posix,
8164 * then it prints short signal names.
8165 * We are printing short names: */
8166 printf(" %s\n", get_signame(i));
8169 /*fflush_all(); - done after each builtin anyway */
8170 return EXIT_SUCCESS;
8174 /* If first arg is a number: reset all specified signals */
8175 sig = bb_strtou(*argv, NULL, 10);
8181 sig = get_signum(*argv++);
8182 if (sig < 0 || sig >= NSIG) {
8184 /* Mimic bash message exactly */
8185 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8190 G.traps[sig] = xstrdup(new_cmd);
8192 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8193 get_signame(sig), sig, G.traps[sig]);
8195 /* There is no signal for 0 (EXIT) */
8200 sigaddset(&G.blocked_set, sig);
8202 /* There was a trap handler, we are removing it
8203 * (if sig has non-DFL handling,
8204 * we don't need to do anything) */
8205 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8207 sigdelset(&G.blocked_set, sig);
8210 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8214 if (!argv[1]) { /* no second arg */
8215 bb_error_msg("trap: invalid arguments");
8216 return EXIT_FAILURE;
8219 /* First arg is "-": reset all specified to default */
8220 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8221 /* Everything else: set arg as signal handler
8222 * (includes "" case, which ignores signal) */
8223 if (argv[0][0] == '-') {
8224 if (argv[0][1] == '\0') { /* "-" */
8225 /* new_cmd remains NULL: "reset these sigs" */
8228 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8231 /* else: "-something", no special meaning */
8236 goto process_sig_list;
8239 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8240 static int FAST_FUNC builtin_type(char **argv)
8242 int ret = EXIT_SUCCESS;
8248 if (0) {} /* make conditional compile easier below */
8249 /*else if (find_alias(*argv))
8250 type = "an alias";*/
8251 #if ENABLE_HUSH_FUNCTIONS
8252 else if (find_function(*argv))
8253 type = "a function";
8255 else if (find_builtin(*argv))
8256 type = "a shell builtin";
8257 else if ((path = find_in_path(*argv)) != NULL)
8260 bb_error_msg("type: %s: not found", *argv);
8265 printf("%s is %s\n", *argv, type);
8273 /* built-in 'fg' and 'bg' handler */
8274 static int FAST_FUNC builtin_fg_bg(char **argv)
8279 if (!G_interactive_fd)
8280 return EXIT_FAILURE;
8282 /* If they gave us no args, assume they want the last backgrounded task */
8284 for (pi = G.job_list; pi; pi = pi->next) {
8285 if (pi->jobid == G.last_jobid) {
8289 bb_error_msg("%s: no current job", argv[0]);
8290 return EXIT_FAILURE;
8292 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8293 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8294 return EXIT_FAILURE;
8296 for (pi = G.job_list; pi; pi = pi->next) {
8297 if (pi->jobid == jobnum) {
8301 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8302 return EXIT_FAILURE;
8304 /* TODO: bash prints a string representation
8305 * of job being foregrounded (like "sleep 1 | cat") */
8306 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8307 /* Put the job into the foreground. */
8308 tcsetpgrp(G_interactive_fd, pi->pgrp);
8311 /* Restart the processes in the job */
8312 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8313 for (i = 0; i < pi->num_cmds; i++) {
8314 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8315 pi->cmds[i].is_stopped = 0;
8317 pi->stopped_cmds = 0;
8319 i = kill(- pi->pgrp, SIGCONT);
8321 if (errno == ESRCH) {
8322 delete_finished_bg_job(pi);
8323 return EXIT_SUCCESS;
8325 bb_perror_msg("kill (SIGCONT)");
8328 if (argv[0][0] == 'f') {
8330 return checkjobs_and_fg_shell(pi);
8332 return EXIT_SUCCESS;
8336 #if ENABLE_HUSH_HELP
8337 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8339 const struct built_in_command *x;
8342 "Built-in commands:\n"
8343 "------------------\n");
8344 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8346 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8349 return EXIT_SUCCESS;
8354 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8357 const char *status_string;
8359 for (job = G.job_list; job; job = job->next) {
8360 if (job->alive_cmds == job->stopped_cmds)
8361 status_string = "Stopped";
8363 status_string = "Running";
8365 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8367 return EXIT_SUCCESS;
8372 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8377 # ifdef M_TRIM_THRESHOLD
8378 /* Optional. Reduces probability of false positives */
8381 /* Crude attempt to find where "free memory" starts,
8382 * sans fragmentation. */
8384 l = (unsigned long)p;
8387 if (l < (unsigned long)p) l = (unsigned long)p;
8390 if (!G.memleak_value)
8391 G.memleak_value = l;
8393 l -= G.memleak_value;
8400 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8405 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8408 return EXIT_SUCCESS;
8411 static int FAST_FUNC builtin_read(char **argv)
8420 /* "!": do not abort on errors.
8421 * Option string must start with "sr" to match BUILTIN_READ_xxx
8423 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8424 if (read_flags == (uint32_t)-1)
8425 return EXIT_FAILURE;
8428 r = shell_builtin_read(set_local_var_from_halves,
8430 get_local_var_value("IFS"), /* can be NULL */
8438 if ((uintptr_t)r > 1) {
8439 bb_error_msg("%s", r);
8440 r = (char*)(uintptr_t)1;
8443 return (uintptr_t)r;
8446 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8447 * built-in 'set' handler
8449 * set [-abCefhmnuvx] [-o option] [argument...]
8450 * set [+abCefhmnuvx] [+o option] [argument...]
8451 * set -- [argument...]
8454 * Implementations shall support the options in both their hyphen and
8455 * plus-sign forms. These options can also be specified as options to sh.
8457 * Write out all variables and their values: set
8458 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8459 * Turn on the -x and -v options: set -xv
8460 * Unset all positional parameters: set --
8461 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8462 * Set the positional parameters to the expansion of x, even if x expands
8463 * with a leading '-' or '+': set -- $x
8465 * So far, we only support "set -- [argument...]" and some of the short names.
8467 static int FAST_FUNC builtin_set(char **argv)
8470 char **pp, **g_argv;
8471 char *arg = *++argv;
8475 for (e = G.top_var; e; e = e->next)
8477 return EXIT_SUCCESS;
8481 if (strcmp(arg, "--") == 0) {
8485 if (arg[0] != '+' && arg[0] != '-')
8487 for (n = 1; arg[n]; ++n) {
8488 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8490 if (arg[n] == 'o' && argv[1])
8493 } while ((arg = *++argv) != NULL);
8494 /* Now argv[0] is 1st argument */
8497 return EXIT_SUCCESS;
8500 /* NB: G.global_argv[0] ($0) is never freed/changed */
8501 g_argv = G.global_argv;
8502 if (G.global_args_malloced) {
8508 G.global_args_malloced = 1;
8509 pp = xzalloc(sizeof(pp[0]) * 2);
8510 pp[0] = g_argv[0]; /* retain $0 */
8513 /* This realloc's G.global_argv */
8514 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8521 return EXIT_SUCCESS;
8523 /* Nothing known, so abort */
8525 bb_error_msg("set: %s: invalid option", arg);
8526 return EXIT_FAILURE;
8529 static int FAST_FUNC builtin_shift(char **argv)
8532 argv = skip_dash_dash(argv);
8536 if (n >= 0 && n < G.global_argc) {
8537 if (G.global_args_malloced) {
8540 free(G.global_argv[m++]);
8543 memmove(&G.global_argv[1], &G.global_argv[n+1],
8544 G.global_argc * sizeof(G.global_argv[0]));
8545 return EXIT_SUCCESS;
8547 return EXIT_FAILURE;
8550 static int FAST_FUNC builtin_source(char **argv)
8552 char *arg_path, *filename;
8555 #if ENABLE_HUSH_FUNCTIONS
8559 argv = skip_dash_dash(argv);
8562 /* bash says: "bash: .: filename argument required" */
8563 return 2; /* bash compat */
8566 if (!strchr(filename, '/')) {
8567 arg_path = find_in_path(filename);
8569 filename = arg_path;
8571 input = fopen_or_warn(filename, "r");
8574 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8575 return EXIT_FAILURE;
8577 close_on_exec_on(fileno(input));
8579 #if ENABLE_HUSH_FUNCTIONS
8580 sv_flg = G.flag_return_in_progress;
8581 /* "we are inside sourced file, ok to use return" */
8582 G.flag_return_in_progress = -1;
8584 save_and_replace_G_args(&sv, argv);
8586 parse_and_run_file(input);
8589 restore_G_args(&sv, argv);
8590 #if ENABLE_HUSH_FUNCTIONS
8591 G.flag_return_in_progress = sv_flg;
8594 return G.last_exitcode;
8597 static int FAST_FUNC builtin_umask(char **argv)
8603 argv = skip_dash_dash(argv);
8605 mode_t old_mask = mask;
8608 rc = bb_parse_mode(argv[0], &mask);
8613 * bash: umask: 'q': invalid symbolic mode operator
8614 * bash: umask: 999: octal number out of range
8616 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8621 printf("%04o\n", (unsigned) mask);
8622 /* fall through and restore mask which we set to 0 */
8626 return !rc; /* rc != 0 - success */
8629 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8630 static int FAST_FUNC builtin_unset(char **argv)
8635 /* "!": do not abort on errors */
8636 /* "+": stop at 1st non-option */
8637 opts = getopt32(argv, "!+vf");
8638 if (opts == (unsigned)-1)
8639 return EXIT_FAILURE;
8641 bb_error_msg("unset: -v and -f are exclusive");
8642 return EXIT_FAILURE;
8648 if (!(opts & 2)) { /* not -f */
8649 if (unset_local_var(*argv)) {
8650 /* unset <nonexistent_var> doesn't fail.
8651 * Error is when one tries to unset RO var.
8652 * Message was printed by unset_local_var. */
8656 #if ENABLE_HUSH_FUNCTIONS
8666 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8667 static int FAST_FUNC builtin_wait(char **argv)
8669 int ret = EXIT_SUCCESS;
8672 argv = skip_dash_dash(argv);
8673 if (argv[0] == NULL) {
8674 /* Don't care about wait results */
8675 /* Note 1: must wait until there are no more children */
8676 /* Note 2: must be interruptible */
8678 * $ sleep 3 & sleep 6 & wait
8683 * $ sleep 3 & sleep 6 & wait
8687 * ^C <-- after ~4 sec from keyboard
8690 sigaddset(&G.blocked_set, SIGCHLD);
8691 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8694 if (errno == ECHILD)
8696 /* Wait for SIGCHLD or any other signal of interest */
8697 /* sigtimedwait with infinite timeout: */
8698 sig = sigwaitinfo(&G.blocked_set, NULL);
8700 sig = check_and_run_traps(sig);
8701 if (sig && sig != SIGCHLD) { /* see note 2 */
8707 sigdelset(&G.blocked_set, SIGCHLD);
8708 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8712 /* This is probably buggy wrt interruptible-ness */
8714 pid_t pid = bb_strtou(*argv, NULL, 10);
8716 /* mimic bash message */
8717 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8718 return EXIT_FAILURE;
8720 if (waitpid(pid, &status, 0) == pid) {
8721 if (WIFSIGNALED(status))
8722 ret = 128 + WTERMSIG(status);
8723 else if (WIFEXITED(status))
8724 ret = WEXITSTATUS(status);
8728 bb_perror_msg("wait %s", *argv);
8737 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8738 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8741 def = bb_strtou(argv[1], NULL, 10);
8742 if (errno || def < def_min || argv[2]) {
8743 bb_error_msg("%s: bad arguments", argv[0]);
8751 #if ENABLE_HUSH_LOOPS
8752 static int FAST_FUNC builtin_break(char **argv)
8755 if (G.depth_of_loop == 0) {
8756 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8757 return EXIT_SUCCESS; /* bash compat */
8759 G.flag_break_continue++; /* BC_BREAK = 1 */
8761 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8762 if (depth == UINT_MAX)
8763 G.flag_break_continue = BC_BREAK;
8764 if (G.depth_of_loop < depth)
8765 G.depth_break_continue = G.depth_of_loop;
8767 return EXIT_SUCCESS;
8770 static int FAST_FUNC builtin_continue(char **argv)
8772 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8773 return builtin_break(argv);
8777 #if ENABLE_HUSH_FUNCTIONS
8778 static int FAST_FUNC builtin_return(char **argv)
8782 if (G.flag_return_in_progress != -1) {
8783 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8784 return EXIT_FAILURE; /* bash compat */
8787 G.flag_return_in_progress = 1;
8790 * out of range: wraps around at 256, does not error out
8791 * non-numeric param:
8792 * f() { false; return qwe; }; f; echo $?
8793 * bash: return: qwe: numeric argument required <== we do this
8794 * 255 <== we also do this
8796 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);