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 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
85 || defined(__APPLE__) \
87 # include <malloc.h> /* for malloc_trim */
90 /* #include <dmalloc.h> */
95 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
97 #include "shell_common.h"
100 #if ENABLE_HUSH_RANDOM_SUPPORT
103 # define CLEAR_RANDOM_T(rnd) ((void)0)
106 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
110 //config: bool "hush"
113 //config: hush is a small shell (25k). It handles the normal flow control
114 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
115 //config: case/esac. Redirections, here documents, $((arithmetic))
116 //config: and functions are supported.
118 //config: It will compile and work on no-mmu systems.
120 //config: It does not handle select, aliases, tilde expansion,
121 //config: &>file and >&file redirection of stdout+stderr.
123 //config:config HUSH_BASH_COMPAT
124 //config: bool "bash-compatible extensions"
126 //config: depends on HUSH
128 //config: Enable bash-compatible extensions.
130 //config:config HUSH_BRACE_EXPANSION
131 //config: bool "Brace expansion"
133 //config: depends on HUSH_BASH_COMPAT
135 //config: Enable {abc,def} extension.
137 //config:config HUSH_HELP
138 //config: bool "help builtin"
140 //config: depends on HUSH
142 //config: Enable help builtin in hush. Code size + ~1 kbyte.
144 //config:config HUSH_INTERACTIVE
145 //config: bool "Interactive mode"
147 //config: depends on HUSH
149 //config: Enable interactive mode (prompt and command editing).
150 //config: Without this, hush simply reads and executes commands
151 //config: from stdin just like a shell script from a file.
152 //config: No prompt, no PS1/PS2 magic shell variables.
154 //config:config HUSH_SAVEHISTORY
155 //config: bool "Save command history to .hush_history"
157 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
159 //config: Enable history saving in hush.
161 //config:config HUSH_JOB
162 //config: bool "Job control"
164 //config: depends on HUSH_INTERACTIVE
166 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
167 //config: command (not entire shell), fg/bg builtins work. Without this option,
168 //config: "cmd &" still works by simply spawning a process and immediately
169 //config: prompting for next command (or executing next command in a script),
170 //config: but no separate process group is formed.
172 //config:config HUSH_TICK
173 //config: bool "Process substitution"
175 //config: depends on HUSH
177 //config: Enable process substitution `command` and $(command) in hush.
179 //config:config HUSH_IF
180 //config: bool "Support if/then/elif/else/fi"
182 //config: depends on HUSH
184 //config: Enable if/then/elif/else/fi in hush.
186 //config:config HUSH_LOOPS
187 //config: bool "Support for, while and until loops"
189 //config: depends on HUSH
191 //config: Enable for, while and until loops in hush.
193 //config:config HUSH_CASE
194 //config: bool "Support case ... esac statement"
196 //config: depends on HUSH
198 //config: Enable case ... esac statement in hush. +400 bytes.
200 //config:config HUSH_FUNCTIONS
201 //config: bool "Support funcname() { commands; } syntax"
203 //config: depends on HUSH
205 //config: Enable support for shell functions in hush. +800 bytes.
207 //config:config HUSH_LOCAL
208 //config: bool "Support local builtin"
210 //config: depends on HUSH_FUNCTIONS
212 //config: Enable support for local variables in functions.
214 //config:config HUSH_RANDOM_SUPPORT
215 //config: bool "Pseudorandom generator and $RANDOM variable"
217 //config: depends on HUSH
219 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
220 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
222 //config:config HUSH_EXPORT_N
223 //config: bool "Support 'export -n' option"
225 //config: depends on HUSH
227 //config: export -n unexports variables. It is a bash extension.
229 //config:config HUSH_MODE_X
230 //config: bool "Support 'hush -x' option and 'set -x' command"
232 //config: depends on HUSH
234 //config: This instructs hush to print commands before execution.
235 //config: Adds ~300 bytes.
238 //config: bool "msh (deprecated: aliased to hush)"
240 //config: select HUSH
242 //config: msh is deprecated and will be removed, please migrate to hush.
245 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
246 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
247 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
248 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
250 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
251 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
253 /* -i (interactive) and -s (read stdin) are also accepted,
254 * but currently do nothing, therefore aren't shown in help.
255 * NOMMU-specific options are not meant to be used by users,
256 * therefore we don't show them either.
258 //usage:#define hush_trivial_usage
259 //usage: "[-nx] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
260 //usage:#define hush_full_usage "\n\n"
261 //usage: "Unix shell interpreter"
263 //usage:#define msh_trivial_usage hush_trivial_usage
264 //usage:#define msh_full_usage hush_full_usage
266 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
267 //usage:# define sh_trivial_usage hush_trivial_usage
268 //usage:# define sh_full_usage hush_full_usage
270 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
271 //usage:# define bash_trivial_usage hush_trivial_usage
272 //usage:# define bash_full_usage hush_full_usage
277 #define LEAK_HUNTING 0
278 #define BUILD_AS_NOMMU 0
279 /* Enable/disable sanity checks. Ok to enable in production,
280 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
281 * Keeping 1 for now even in released versions.
284 /* Slightly bigger (+200 bytes), but faster hush.
285 * So far it only enables a trick with counting SIGCHLDs and forks,
286 * which allows us to do fewer waitpid's.
287 * (we can detect a case where neither forks were done nor SIGCHLDs happened
288 * and therefore waitpid will return the same result as last time)
290 #define ENABLE_HUSH_FAST 0
291 /* TODO: implement simplified code for users which do not need ${var%...} ops
292 * So far ${var%...} ops are always enabled:
294 #define ENABLE_HUSH_DOLLAR_OPS 1
299 # undef USE_FOR_NOMMU
302 # define USE_FOR_NOMMU(...) __VA_ARGS__
303 # define USE_FOR_MMU(...)
306 #include "NUM_APPLETS.h"
308 /* STANDALONE does not make sense, and won't compile */
309 # undef CONFIG_FEATURE_SH_STANDALONE
310 # undef ENABLE_FEATURE_SH_STANDALONE
311 # undef IF_FEATURE_SH_STANDALONE
312 # undef IF_NOT_FEATURE_SH_STANDALONE
313 # define ENABLE_FEATURE_SH_STANDALONE 0
314 # define IF_FEATURE_SH_STANDALONE(...)
315 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
318 #if !ENABLE_HUSH_INTERACTIVE
319 # undef ENABLE_FEATURE_EDITING
320 # define ENABLE_FEATURE_EDITING 0
321 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
322 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
325 /* Do we support ANY keywords? */
326 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
327 # define HAS_KEYWORDS 1
328 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
329 # define IF_HAS_NO_KEYWORDS(...)
331 # define HAS_KEYWORDS 0
332 # define IF_HAS_KEYWORDS(...)
333 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
336 /* If you comment out one of these below, it will be #defined later
337 * to perform debug printfs to stderr: */
338 #define debug_printf(...) do {} while (0)
339 /* Finer-grained debug switches */
340 #define debug_printf_parse(...) do {} while (0)
341 #define debug_print_tree(a, b) do {} while (0)
342 #define debug_printf_exec(...) do {} while (0)
343 #define debug_printf_env(...) do {} while (0)
344 #define debug_printf_jobs(...) do {} while (0)
345 #define debug_printf_expand(...) do {} while (0)
346 #define debug_printf_varexp(...) do {} while (0)
347 #define debug_printf_glob(...) do {} while (0)
348 #define debug_printf_list(...) do {} while (0)
349 #define debug_printf_subst(...) do {} while (0)
350 #define debug_printf_clean(...) do {} while (0)
352 #define ERR_PTR ((void*)(long)1)
354 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
356 #define _SPECIAL_VARS_STR "_*@$!?#"
357 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
358 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
359 #if ENABLE_HUSH_BASH_COMPAT
360 /* Support / and // replace ops */
361 /* Note that // is stored as \ in "encoded" string representation */
362 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
363 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
364 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
366 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
367 # define VAR_SUBST_OPS "%#:-=+?"
368 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
371 #define SPECIAL_VAR_SYMBOL 3
375 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
377 /* This supports saving pointers malloced in vfork child,
378 * to be freed in the parent.
381 typedef struct nommu_save_t {
383 struct variable *old_vars;
385 char **argv_from_re_execing;
398 #if ENABLE_HUSH_LOOPS
405 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
410 /* three pseudo-keywords support contrived "case" syntax: */
411 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
412 RES_MATCH , /* "word)" */
413 RES_CASE_BODY, /* "this command is inside CASE" */
420 typedef struct o_string {
422 int length; /* position where data is appended */
425 /* At least some part of the string was inside '' or "",
426 * possibly empty one: word"", wo''rd etc. */
427 smallint has_quoted_part;
428 smallint has_empty_slot;
429 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
432 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
434 /* Protect newly added chars against globbing
435 * by prepending \ to *, ?, [, \ */
436 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
439 MAYBE_ASSIGNMENT = 0,
440 DEFINITELY_ASSIGNMENT = 1,
442 /* Not an assigment, but next word may be: "if v=xyz cmd;" */
445 /* Used for initialization: o_string foo = NULL_O_STRING; */
446 #define NULL_O_STRING { NULL }
448 typedef struct in_str {
450 /* eof_flag=1: last char in ->p is really an EOF */
451 char eof_flag; /* meaningless if ->p == NULL */
453 #if ENABLE_HUSH_INTERACTIVE
454 smallint promptmode; /* 0: PS1, 1: PS2 */
458 int (*get) (struct in_str *) FAST_FUNC;
459 int (*peek) (struct in_str *) FAST_FUNC;
461 #define i_getch(input) ((input)->get(input))
462 #define i_peek(input) ((input)->peek(input))
464 /* The descrip member of this structure is only used to make
465 * debugging output pretty */
466 static const struct {
468 signed char default_fd;
471 { O_RDONLY, 0, "<" },
472 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
473 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
474 { O_CREAT|O_RDWR, 1, "<>" },
475 { O_RDONLY, 0, "<<" },
476 /* Should not be needed. Bogus default_fd helps in debugging */
477 /* { O_RDONLY, 77, "<<" }, */
480 struct redir_struct {
481 struct redir_struct *next;
482 char *rd_filename; /* filename */
483 int rd_fd; /* fd to redirect */
484 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
486 smallint rd_type; /* (enum redir_type) */
487 /* note: for heredocs, rd_filename contains heredoc delimiter,
488 * and subsequently heredoc itself; and rd_dup is a bitmask:
489 * bit 0: do we need to trim leading tabs?
490 * bit 1: is heredoc quoted (<<'delim' syntax) ?
493 typedef enum redir_type {
495 REDIRECT_OVERWRITE = 1,
498 REDIRECT_HEREDOC = 4,
499 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
502 REDIRFD_SYNTAX_ERR = -2,
503 REDIRFD_TO_FILE = -1,
504 /* otherwise, rd_fd is redirected to rd_dup */
506 HEREDOC_SKIPTABS = 1,
512 pid_t pid; /* 0 if exited */
513 int assignment_cnt; /* how many argv[i] are assignments? */
514 smallint is_stopped; /* is the command currently running? */
515 smallint cmd_type; /* CMD_xxx */
517 #define CMD_SUBSHELL 1
518 #if ENABLE_HUSH_BASH_COMPAT
519 /* used for "[[ EXPR ]]" */
520 # define CMD_SINGLEWORD_NOGLOB 2
522 #if ENABLE_HUSH_FUNCTIONS
523 # define CMD_FUNCDEF 3
526 smalluint cmd_exitcode;
527 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
530 char *group_as_string;
532 #if ENABLE_HUSH_FUNCTIONS
533 struct function *child_func;
534 /* This field is used to prevent a bug here:
535 * while...do f1() {a;}; f1; f1() {b;}; f1; done
536 * When we execute "f1() {a;}" cmd, we create new function and clear
537 * cmd->group, cmd->group_as_string, cmd->argv[0].
538 * When we execute "f1() {b;}", we notice that f1 exists,
539 * and that its "parent cmd" struct is still "alive",
540 * we put those fields back into cmd->xxx
541 * (struct function has ->parent_cmd ptr to facilitate that).
542 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
543 * Without this trick, loop would execute a;b;b;b;...
544 * instead of correct sequence a;b;a;b;...
545 * When command is freed, it severs the link
546 * (sets ->child_func->parent_cmd to NULL).
549 char **argv; /* command name and arguments */
550 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
551 * and on execution these are substituted with their values.
552 * Substitution can make _several_ words out of one argv[n]!
553 * Example: argv[0]=='.^C*^C.' here: echo .$*.
554 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
556 struct redir_struct *redirects; /* I/O redirections */
558 /* Is there anything in this command at all? */
559 #define IS_NULL_CMD(cmd) \
560 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
564 int num_cmds; /* total number of commands in pipe */
565 int alive_cmds; /* number of commands running (not exited) */
566 int stopped_cmds; /* number of commands alive, but stopped */
568 int jobid; /* job number */
569 pid_t pgrp; /* process group ID for the job */
570 char *cmdtext; /* name of job */
572 struct command *cmds; /* array of commands in pipe */
573 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
574 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
575 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
577 typedef enum pipe_style {
583 /* Is there anything in this pipe at all? */
584 #define IS_NULL_PIPE(pi) \
585 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
587 /* This holds pointers to the various results of parsing */
588 struct parse_context {
589 /* linked list of pipes */
590 struct pipe *list_head;
591 /* last pipe (being constructed right now) */
593 /* last command in pipe (being constructed right now) */
594 struct command *command;
595 /* last redirect in command->redirects list */
596 struct redir_struct *pending_redirect;
602 smallint ctx_inverted; /* "! cmd | cmd" */
604 smallint ctx_dsemicolon; /* ";;" seen */
606 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
608 /* group we are enclosed in:
609 * example: "if pipe1; pipe2; then pipe3; fi"
610 * when we see "if" or "then", we malloc and copy current context,
611 * and make ->stack point to it. then we parse pipeN.
612 * when closing "then" / fi" / whatever is found,
613 * we move list_head into ->stack->command->group,
614 * copy ->stack into current context, and delete ->stack.
615 * (parsing of { list } and ( list ) doesn't use this method)
617 struct parse_context *stack;
621 /* On program start, environ points to initial environment.
622 * putenv adds new pointers into it, unsetenv removes them.
623 * Neither of these (de)allocates the strings.
624 * setenv allocates new strings in malloc space and does putenv,
625 * and thus setenv is unusable (leaky) for shell's purposes */
626 #define setenv(...) setenv_is_leaky_dont_use()
628 struct variable *next;
629 char *varstr; /* points to "name=" portion */
630 #if ENABLE_HUSH_LOCAL
631 unsigned func_nest_level;
633 int max_len; /* if > 0, name is part of initial env; else name is malloced */
634 smallint flg_export; /* putenv should be done on this var */
635 smallint flg_read_only;
643 #if ENABLE_HUSH_FUNCTIONS
645 struct function *next;
647 struct command *parent_cmd;
650 char *body_as_string;
656 /* set -/+o OPT support. (TODO: make it optional)
657 * bash supports the following opts:
668 * interactive-comments on
686 static const char o_opt_strings[] ALIGN1 =
689 #if ENABLE_HUSH_MODE_X
696 #if ENABLE_HUSH_MODE_X
703 /* "Globals" within this file */
704 /* Sorted roughly by size (smaller offsets == smaller code) */
706 /* interactive_fd != 0 means we are an interactive shell.
707 * If we are, then saved_tty_pgrp can also be != 0, meaning
708 * that controlling tty is available. With saved_tty_pgrp == 0,
709 * job control still works, but terminal signals
710 * (^C, ^Z, ^Y, ^\) won't work at all, and background
711 * process groups can only be created with "cmd &".
712 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
713 * to give tty to the foreground process group,
714 * and will take it back when the group is stopped (^Z)
717 #if ENABLE_HUSH_INTERACTIVE
718 /* 'interactive_fd' is a fd# open to ctty, if we have one
719 * _AND_ if we decided to act interactively */
723 # define G_interactive_fd (G.interactive_fd)
725 # define G_interactive_fd 0
727 #if ENABLE_FEATURE_EDITING
728 line_input_t *line_input_state;
733 #if ENABLE_HUSH_RANDOM_SUPPORT
739 pid_t saved_tty_pgrp;
740 struct pipe *job_list;
741 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
743 # define G_saved_tty_pgrp 0
745 char o_opt[NUM_OPT_O];
746 #if ENABLE_HUSH_MODE_X
747 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
751 smallint flag_SIGINT;
752 #if ENABLE_HUSH_LOOPS
753 smallint flag_break_continue;
755 #if ENABLE_HUSH_FUNCTIONS
756 /* 0: outside of a function (or sourced file)
757 * -1: inside of a function, ok to use return builtin
758 * 1: return is invoked, skip all till end of func
760 smallint flag_return_in_progress;
762 smallint exiting; /* used to prevent EXIT trap recursion */
763 /* These four support $?, $#, and $1 */
764 smalluint last_exitcode;
765 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
766 smalluint global_args_malloced;
767 smalluint inherited_set_is_saved;
768 /* how many non-NULL argv's we have. NB: $# + 1 */
772 char *argv0_for_re_execing;
774 #if ENABLE_HUSH_LOOPS
775 unsigned depth_break_continue;
776 unsigned depth_of_loop;
780 struct variable *top_var;
781 char **expanded_assignments;
782 #if ENABLE_HUSH_FUNCTIONS
783 struct function *top_func;
784 # if ENABLE_HUSH_LOCAL
785 struct variable **shadowed_vars_pp;
786 unsigned func_nest_level;
789 /* Signal and trap handling */
791 unsigned count_SIGCHLD;
792 unsigned handled_SIGCHLD;
793 smallint we_have_children;
795 /* which signals have non-DFL handler (even with no traps set)? */
796 unsigned non_DFL_mask;
797 char **traps; /* char *traps[NSIG] */
798 sigset_t blocked_set;
799 sigset_t inherited_set;
801 unsigned long memleak_value;
804 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
806 #define G (*ptr_to_globals)
807 /* Not #defining name to G.name - this quickly gets unwieldy
808 * (too many defines). Also, I actually prefer to see when a variable
809 * is global, thus "G." prefix is a useful hint */
810 #define INIT_G() do { \
811 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
815 /* Function prototypes for builtins */
816 static int builtin_cd(char **argv) FAST_FUNC;
817 static int builtin_echo(char **argv) FAST_FUNC;
818 static int builtin_eval(char **argv) FAST_FUNC;
819 static int builtin_exec(char **argv) FAST_FUNC;
820 static int builtin_exit(char **argv) FAST_FUNC;
821 static int builtin_export(char **argv) FAST_FUNC;
823 static int builtin_fg_bg(char **argv) FAST_FUNC;
824 static int builtin_jobs(char **argv) FAST_FUNC;
827 static int builtin_help(char **argv) FAST_FUNC;
829 #if ENABLE_HUSH_LOCAL
830 static int builtin_local(char **argv) FAST_FUNC;
833 static int builtin_memleak(char **argv) FAST_FUNC;
836 static int builtin_printf(char **argv) FAST_FUNC;
838 static int builtin_pwd(char **argv) FAST_FUNC;
839 static int builtin_read(char **argv) FAST_FUNC;
840 static int builtin_set(char **argv) FAST_FUNC;
841 static int builtin_shift(char **argv) FAST_FUNC;
842 static int builtin_source(char **argv) FAST_FUNC;
843 static int builtin_test(char **argv) FAST_FUNC;
844 static int builtin_trap(char **argv) FAST_FUNC;
845 static int builtin_type(char **argv) FAST_FUNC;
846 static int builtin_true(char **argv) FAST_FUNC;
847 static int builtin_umask(char **argv) FAST_FUNC;
848 static int builtin_unset(char **argv) FAST_FUNC;
849 static int builtin_wait(char **argv) FAST_FUNC;
850 #if ENABLE_HUSH_LOOPS
851 static int builtin_break(char **argv) FAST_FUNC;
852 static int builtin_continue(char **argv) FAST_FUNC;
854 #if ENABLE_HUSH_FUNCTIONS
855 static int builtin_return(char **argv) FAST_FUNC;
858 /* Table of built-in functions. They can be forked or not, depending on
859 * context: within pipes, they fork. As simple commands, they do not.
860 * When used in non-forking context, they can change global variables
861 * in the parent shell process. If forked, of course they cannot.
862 * For example, 'unset foo | whatever' will parse and run, but foo will
863 * still be set at the end. */
864 struct built_in_command {
866 int (*b_function)(char **argv) FAST_FUNC;
869 # define BLTIN(cmd, func, help) { cmd, func, help }
871 # define BLTIN(cmd, func, help) { cmd, func }
875 static const struct built_in_command bltins1[] = {
876 BLTIN("." , builtin_source , "Run commands in a file"),
877 BLTIN(":" , builtin_true , NULL),
879 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
881 #if ENABLE_HUSH_LOOPS
882 BLTIN("break" , builtin_break , "Exit from a loop"),
884 BLTIN("cd" , builtin_cd , "Change directory"),
885 #if ENABLE_HUSH_LOOPS
886 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
888 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
889 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
890 BLTIN("exit" , builtin_exit , "Exit"),
891 BLTIN("export" , builtin_export , "Set environment variables"),
893 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
896 BLTIN("help" , builtin_help , NULL),
899 BLTIN("jobs" , builtin_jobs , "List jobs"),
901 #if ENABLE_HUSH_LOCAL
902 BLTIN("local" , builtin_local , "Set local variables"),
905 BLTIN("memleak" , builtin_memleak , NULL),
907 BLTIN("read" , builtin_read , "Input into variable"),
908 #if ENABLE_HUSH_FUNCTIONS
909 BLTIN("return" , builtin_return , "Return from a function"),
911 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
912 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
913 #if ENABLE_HUSH_BASH_COMPAT
914 BLTIN("source" , builtin_source , "Run commands in a file"),
916 BLTIN("trap" , builtin_trap , "Trap signals"),
917 BLTIN("type" , builtin_type , "Show command type"),
918 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
919 BLTIN("umask" , builtin_umask , "Set file creation mask"),
920 BLTIN("unset" , builtin_unset , "Unset variables"),
921 BLTIN("wait" , builtin_wait , "Wait for process"),
923 /* For now, echo and test are unconditionally enabled.
924 * Maybe make it configurable? */
925 static const struct built_in_command bltins2[] = {
926 BLTIN("[" , builtin_test , NULL),
927 BLTIN("echo" , builtin_echo , NULL),
929 BLTIN("printf" , builtin_printf , NULL),
931 BLTIN("pwd" , builtin_pwd , NULL),
932 BLTIN("test" , builtin_test , NULL),
939 /* prevent disasters with G.debug_indent < 0 */
940 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
941 # define debug_enter() (G.debug_indent++)
942 # define debug_leave() (G.debug_indent--)
944 # define indent() ((void)0)
945 # define debug_enter() ((void)0)
946 # define debug_leave() ((void)0)
950 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
953 #ifndef debug_printf_parse
954 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
957 #ifndef debug_printf_exec
958 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
961 #ifndef debug_printf_env
962 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
965 #ifndef debug_printf_jobs
966 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
967 # define DEBUG_JOBS 1
969 # define DEBUG_JOBS 0
972 #ifndef debug_printf_expand
973 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
974 # define DEBUG_EXPAND 1
976 # define DEBUG_EXPAND 0
979 #ifndef debug_printf_varexp
980 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
983 #ifndef debug_printf_glob
984 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
985 # define DEBUG_GLOB 1
987 # define DEBUG_GLOB 0
990 #ifndef debug_printf_list
991 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
994 #ifndef debug_printf_subst
995 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
998 #ifndef debug_printf_clean
999 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1000 # define DEBUG_CLEAN 1
1002 # define DEBUG_CLEAN 0
1006 static void debug_print_strings(const char *prefix, char **vv)
1009 fdprintf(2, "%s:\n", prefix);
1011 fdprintf(2, " '%s'\n", *vv++);
1014 # define debug_print_strings(prefix, vv) ((void)0)
1018 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1021 static void *xxmalloc(int lineno, size_t size)
1023 void *ptr = xmalloc((size + 0xff) & ~0xff);
1024 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1027 static void *xxrealloc(int lineno, void *ptr, size_t size)
1029 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1030 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1033 static char *xxstrdup(int lineno, const char *str)
1035 char *ptr = xstrdup(str);
1036 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1039 static void xxfree(void *ptr)
1041 fdprintf(2, "free %p\n", ptr);
1044 # define xmalloc(s) xxmalloc(__LINE__, s)
1045 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1046 # define xstrdup(s) xxstrdup(__LINE__, s)
1047 # define free(p) xxfree(p)
1051 /* Syntax and runtime errors. They always abort scripts.
1052 * In interactive use they usually discard unparsed and/or unexecuted commands
1053 * and return to the prompt.
1054 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1057 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1058 # define syntax_error(lineno, msg) syntax_error(msg)
1059 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1060 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1061 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1062 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1065 static void die_if_script(unsigned lineno, const char *fmt, ...)
1070 bb_error_msg("hush.c:%u", lineno);
1073 bb_verror_msg(fmt, p, NULL);
1075 if (!G_interactive_fd)
1079 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1082 bb_error_msg("syntax error: %s", msg);
1084 bb_error_msg("syntax error");
1087 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1089 bb_error_msg("syntax error at '%s'", msg);
1092 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1094 bb_error_msg("syntax error: unterminated %s", s);
1097 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1099 char msg[2] = { ch, '\0' };
1100 syntax_error_unterm_str(lineno, msg);
1103 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1108 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1112 # undef die_if_script
1113 # undef syntax_error
1114 # undef syntax_error_at
1115 # undef syntax_error_unterm_ch
1116 # undef syntax_error_unterm_str
1117 # undef syntax_error_unexpected_ch
1119 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1120 # define syntax_error(msg) syntax_error(__LINE__, msg)
1121 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1122 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1123 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1124 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1128 #if ENABLE_HUSH_INTERACTIVE
1129 static void cmdedit_update_prompt(void);
1131 # define cmdedit_update_prompt() ((void)0)
1135 /* Utility functions
1137 /* Replace each \x with x in place, return ptr past NUL. */
1138 static char *unbackslash(char *src)
1140 char *dst = src = strchrnul(src, '\\');
1144 if ((*dst++ = *src++) == '\0')
1150 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1171 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1172 v[count1 + count2] = NULL;
1175 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1179 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1181 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1182 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1185 #define add_strings_to_strings(strings, add, need_to_dup) \
1186 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1189 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1190 static char **add_string_to_strings(char **strings, char *add)
1195 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1198 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1200 char **ptr = add_string_to_strings(strings, add);
1201 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1204 #define add_string_to_strings(strings, add) \
1205 xx_add_string_to_strings(__LINE__, strings, add)
1208 static void free_strings(char **strings)
1223 /* Helpers for setting new $n and restoring them back
1225 typedef struct save_arg_t {
1229 smallint sv_g_malloced;
1232 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1236 sv->sv_argv0 = argv[0];
1237 sv->sv_g_argv = G.global_argv;
1238 sv->sv_g_argc = G.global_argc;
1239 sv->sv_g_malloced = G.global_args_malloced;
1241 argv[0] = G.global_argv[0]; /* retain $0 */
1242 G.global_argv = argv;
1243 G.global_args_malloced = 0;
1251 static void restore_G_args(save_arg_t *sv, char **argv)
1255 if (G.global_args_malloced) {
1256 /* someone ran "set -- arg1 arg2 ...", undo */
1258 while (*++pp) /* note: does not free $0 */
1260 free(G.global_argv);
1262 argv[0] = sv->sv_argv0;
1263 G.global_argv = sv->sv_g_argv;
1264 G.global_argc = sv->sv_g_argc;
1265 G.global_args_malloced = sv->sv_g_malloced;
1269 /* Basic theory of signal handling in shell
1270 * ========================================
1271 * This does not describe what hush does, rather, it is current understanding
1272 * what it _should_ do. If it doesn't, it's a bug.
1273 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1275 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1276 * is finished or backgrounded. It is the same in interactive and
1277 * non-interactive shells, and is the same regardless of whether
1278 * a user trap handler is installed or a shell special one is in effect.
1279 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1280 * backgrounds (i.e. stops) or kills all members of currently running
1283 * Wait builtin in interruptible by signals for which user trap is set
1284 * or by SIGINT in interactive shell.
1286 * Trap handlers will execute even within trap handlers. (right?)
1288 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1289 * except for handlers set to '' (empty string).
1291 * If job control is off, backgrounded commands ("cmd &")
1292 * have SIGINT, SIGQUIT set to SIG_IGN.
1294 * Commands which are run in command substitution ("`cmd`")
1295 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1297 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1298 * by the shell from its parent.
1300 * Signals which differ from SIG_DFL action
1301 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1304 * SIGTERM (interactive): ignore
1305 * SIGHUP (interactive):
1306 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1307 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1308 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1309 * that all pipe members are stopped. Try this in bash:
1310 * while :; do :; done - ^Z does not background it
1311 * (while :; do :; done) - ^Z backgrounds it
1312 * SIGINT (interactive): wait for last pipe, ignore the rest
1313 * of the command line, show prompt. NB: ^C does not send SIGINT
1314 * to interactive shell while shell is waiting for a pipe,
1315 * since shell is bg'ed (is not in foreground process group).
1316 * Example 1: this waits 5 sec, but does not execute ls:
1317 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1318 * Example 2: this does not wait and does not execute ls:
1319 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1320 * Example 3: this does not wait 5 sec, but executes ls:
1321 * "sleep 5; ls -l" + press ^C
1323 * (What happens to signals which are IGN on shell start?)
1324 * (What happens with signal mask on shell start?)
1326 * Implementation in hush
1327 * ======================
1328 * We use in-kernel pending signal mask to determine which signals were sent.
1329 * We block all signals which we don't want to take action immediately,
1330 * i.e. we block all signals which need to have special handling as described
1331 * above, and all signals which have traps set.
1332 * After each pipe execution, we extract any pending signals via sigtimedwait()
1335 * unsigned non_DFL_mask: a mask of such "special" signals
1336 * sigset_t blocked_set: current blocked signal set
1339 * clear bit in blocked_set unless it is also in non_DFL_mask
1340 * "trap 'cmd' SIGxxx":
1341 * set bit in blocked_set (even if 'cmd' is '')
1342 * after [v]fork, if we plan to be a shell:
1343 * unblock signals with special interactive handling
1344 * (child shell is not interactive),
1345 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1346 * after [v]fork, if we plan to exec:
1347 * POSIX says fork clears pending signal mask in child - no need to clear it.
1348 * Restore blocked signal set to one inherited by shell just prior to exec.
1350 * Note: as a result, we do not use signal handlers much. The only uses
1351 * are to count SIGCHLDs
1352 * and to restore tty pgrp on signal-induced exit.
1355 * Standard says "When a subshell is entered, traps that are not being ignored
1356 * are set to the default actions". bash interprets it so that traps which
1357 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1360 SPECIAL_INTERACTIVE_SIGS = 0
1365 SPECIAL_JOB_SIGS = 0
1373 #if ENABLE_HUSH_FAST
1374 static void SIGCHLD_handler(int sig UNUSED_PARAM)
1377 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1383 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1384 # define disable_restore_tty_pgrp_on_exit() (die_sleep = 0)
1385 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1386 # define enable_restore_tty_pgrp_on_exit() (die_sleep = -1)
1388 /* Restores tty foreground process group, and exits.
1389 * May be called as signal handler for fatal signal
1390 * (will resend signal to itself, producing correct exit state)
1391 * or called directly with -EXITCODE.
1392 * We also call it if xfunc is exiting. */
1393 static void sigexit(int sig) NORETURN;
1394 static void sigexit(int sig)
1396 /* Disable all signals: job control, SIGPIPE, etc. */
1397 sigprocmask_allsigs(SIG_BLOCK);
1399 /* Careful: we can end up here after [v]fork. Do not restore
1400 * tty pgrp then, only top-level shell process does that */
1401 if (G_saved_tty_pgrp && getpid() == G.root_pid)
1402 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1404 /* Not a signal, just exit */
1408 kill_myself_with_sig(sig); /* does not return */
1412 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1413 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1417 /* Restores tty foreground process group, and exits. */
1418 static void hush_exit(int exitcode) NORETURN;
1419 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
1437 #if ENABLE_FEATURE_CLEAN_UP
1439 struct variable *cur_var;
1440 if (G.cwd != bb_msg_unknown)
1442 cur_var = G.top_var;
1444 struct variable *tmp = cur_var;
1445 if (!cur_var->max_len)
1446 free(cur_var->varstr);
1447 cur_var = cur_var->next;
1455 sigexit(- (exitcode & 0xff));
1462 static int check_and_run_traps(int sig)
1464 /* I want it in rodata, not in bss.
1465 * gcc 4.2.1 puts it in rodata only if it has { 0, 0 }
1466 * initializer. But other compilers may still use bss.
1467 * TODO: find more portable solution.
1469 static const struct timespec zero_timespec = { 0, 0 };
1470 smalluint save_rcode;
1476 sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec);
1481 if (G.traps && G.traps[sig]) {
1482 if (G.traps[sig][0]) {
1483 /* We have user-defined handler */
1485 /* argv[0] is unused */
1486 argv[1] = G.traps[sig];
1488 save_rcode = G.last_exitcode;
1490 G.last_exitcode = save_rcode;
1491 } /* else: "" trap, ignoring signal */
1494 /* not a trap: special action */
1496 #if ENABLE_HUSH_FAST
1499 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1503 /* Builtin was ^C'ed, make it look prettier: */
1510 /* bash is observed to signal whole process groups,
1511 * not individual processes */
1512 for (job = G.job_list; job; job = job->next) {
1515 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1516 if (kill(- job->pgrp, SIGHUP) == 0)
1517 kill(- job->pgrp, SIGCONT);
1522 default: /* ignored: */
1523 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1531 static const char *get_cwd(int force)
1533 if (force || G.cwd == NULL) {
1534 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1535 * we must not try to free(bb_msg_unknown) */
1536 if (G.cwd == bb_msg_unknown)
1538 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1540 G.cwd = bb_msg_unknown;
1547 * Shell and environment variable support
1549 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1551 struct variable **pp;
1552 struct variable *cur;
1555 while ((cur = *pp) != NULL) {
1556 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1563 static const char* FAST_FUNC get_local_var_value(const char *name)
1565 struct variable **vpp;
1566 unsigned len = strlen(name);
1568 if (G.expanded_assignments) {
1569 char **cpp = G.expanded_assignments;
1572 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1573 return cp + len + 1;
1578 vpp = get_ptr_to_local_var(name, len);
1580 return (*vpp)->varstr + len + 1;
1582 if (strcmp(name, "PPID") == 0)
1583 return utoa(G.root_ppid);
1584 // bash compat: UID? EUID?
1585 #if ENABLE_HUSH_RANDOM_SUPPORT
1586 if (strcmp(name, "RANDOM") == 0)
1587 return utoa(next_random(&G.random_gen));
1592 /* str holds "NAME=VAL" and is expected to be malloced.
1593 * We take ownership of it.
1595 * 0: do not change export flag
1596 * (if creating new variable, flag will be 0)
1597 * 1: set export flag and putenv the variable
1598 * -1: clear export flag and unsetenv the variable
1599 * flg_read_only is set only when we handle -R var=val
1601 #if !BB_MMU && ENABLE_HUSH_LOCAL
1602 /* all params are used */
1603 #elif BB_MMU && ENABLE_HUSH_LOCAL
1604 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1605 set_local_var(str, flg_export, local_lvl)
1606 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1607 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1608 set_local_var(str, flg_export)
1609 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1610 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1611 set_local_var(str, flg_export, flg_read_only)
1613 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1615 struct variable **var_pp;
1616 struct variable *cur;
1620 eq_sign = strchr(str, '=');
1621 if (!eq_sign) { /* not expected to ever happen? */
1626 name_len = eq_sign - str + 1; /* including '=' */
1627 var_pp = &G.top_var;
1628 while ((cur = *var_pp) != NULL) {
1629 if (strncmp(cur->varstr, str, name_len) != 0) {
1630 var_pp = &cur->next;
1633 /* We found an existing var with this name */
1634 if (cur->flg_read_only) {
1638 bb_error_msg("%s: readonly variable", str);
1642 if (flg_export == -1) { // "&& cur->flg_export" ?
1643 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1648 #if ENABLE_HUSH_LOCAL
1649 if (cur->func_nest_level < local_lvl) {
1650 /* New variable is declared as local,
1651 * and existing one is global, or local
1652 * from enclosing function.
1653 * Remove and save old one: */
1654 *var_pp = cur->next;
1655 cur->next = *G.shadowed_vars_pp;
1656 *G.shadowed_vars_pp = cur;
1657 /* bash 3.2.33(1) and exported vars:
1659 * # f() { local z=a; env | grep ^z; }
1665 if (cur->flg_export)
1670 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1675 if (cur->max_len != 0) {
1676 if (cur->max_len >= strlen(str)) {
1677 /* This one is from startup env, reuse space */
1678 strcpy(cur->varstr, str);
1682 /* max_len == 0 signifies "malloced" var, which we can
1683 * (and has to) free */
1687 goto set_str_and_exp;
1690 /* Not found - create new variable struct */
1691 cur = xzalloc(sizeof(*cur));
1692 #if ENABLE_HUSH_LOCAL
1693 cur->func_nest_level = local_lvl;
1695 cur->next = *var_pp;
1701 cur->flg_read_only = flg_read_only;
1704 if (flg_export == 1)
1705 cur->flg_export = 1;
1706 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1707 cmdedit_update_prompt();
1708 if (cur->flg_export) {
1709 if (flg_export == -1) {
1710 cur->flg_export = 0;
1711 /* unsetenv was already done */
1713 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1714 return putenv(cur->varstr);
1720 /* Used at startup and after each cd */
1721 static void set_pwd_var(int exp)
1723 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1724 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1727 static int unset_local_var_len(const char *name, int name_len)
1729 struct variable *cur;
1730 struct variable **var_pp;
1733 return EXIT_SUCCESS;
1734 var_pp = &G.top_var;
1735 while ((cur = *var_pp) != NULL) {
1736 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1737 if (cur->flg_read_only) {
1738 bb_error_msg("%s: readonly variable", name);
1739 return EXIT_FAILURE;
1741 *var_pp = cur->next;
1742 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1743 bb_unsetenv(cur->varstr);
1744 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1745 cmdedit_update_prompt();
1749 return EXIT_SUCCESS;
1751 var_pp = &cur->next;
1753 return EXIT_SUCCESS;
1756 static int unset_local_var(const char *name)
1758 return unset_local_var_len(name, strlen(name));
1761 static void unset_vars(char **strings)
1769 const char *eq = strchrnul(*v, '=');
1770 unset_local_var_len(*v, (int)(eq - *v));
1776 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1778 char *var = xasprintf("%s=%s", name, val);
1779 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1784 * Helpers for "var1=val1 var2=val2 cmd" feature
1786 static void add_vars(struct variable *var)
1788 struct variable *next;
1792 var->next = G.top_var;
1794 if (var->flg_export) {
1795 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1796 putenv(var->varstr);
1798 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1804 static struct variable *set_vars_and_save_old(char **strings)
1807 struct variable *old = NULL;
1813 struct variable *var_p;
1814 struct variable **var_pp;
1817 eq = strchr(*s, '=');
1819 var_pp = get_ptr_to_local_var(*s, eq - *s);
1821 /* Remove variable from global linked list */
1823 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1824 *var_pp = var_p->next;
1825 /* Add it to returned list */
1829 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1840 static int FAST_FUNC static_get(struct in_str *i)
1851 static int FAST_FUNC static_peek(struct in_str *i)
1856 #if ENABLE_HUSH_INTERACTIVE
1858 static void cmdedit_update_prompt(void)
1860 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1861 G.PS1 = get_local_var_value("PS1");
1864 G.PS2 = get_local_var_value("PS2");
1872 static const char *setup_prompt_string(int promptmode)
1874 const char *prompt_str;
1875 debug_printf("setup_prompt_string %d ", promptmode);
1876 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
1877 /* Set up the prompt */
1878 if (promptmode == 0) { /* PS1 */
1880 /* bash uses $PWD value, even if it is set by user.
1881 * It uses current dir only if PWD is unset.
1882 * We always use current dir. */
1883 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
1888 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
1889 debug_printf("result '%s'\n", prompt_str);
1893 static void get_user_input(struct in_str *i)
1896 const char *prompt_str;
1898 prompt_str = setup_prompt_string(i->promptmode);
1899 # if ENABLE_FEATURE_EDITING
1900 /* Enable command line editing only while a command line
1901 * is actually being read */
1903 /* Unicode support should be activated even if LANG is set
1904 * _during_ shell execution, not only if it was set when
1905 * shell was started. Therefore, re-check LANG every time:
1907 reinit_unicode(get_local_var_value("LANG"));
1910 /* buglet: SIGINT will not make new prompt to appear _at once_,
1911 * only after <Enter>. (^C will work) */
1912 r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
1913 /* catch *SIGINT* etc (^C is handled by read_line_input) */
1914 check_and_run_traps(0);
1915 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
1916 i->eof_flag = (r < 0);
1917 if (i->eof_flag) { /* EOF/error detected */
1918 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
1919 G.user_input_buf[1] = '\0';
1924 fputs(prompt_str, stdout);
1926 G.user_input_buf[0] = r = fgetc(i->file);
1927 /*G.user_input_buf[1] = '\0'; - already is and never changed */
1928 //do we need check_and_run_traps(0)? (maybe only if stdin)
1929 } while (G.flag_SIGINT);
1930 i->eof_flag = (r == EOF);
1932 i->p = G.user_input_buf;
1935 #endif /* INTERACTIVE */
1937 /* This is the magic location that prints prompts
1938 * and gets data back from the user */
1939 static int FAST_FUNC file_get(struct in_str *i)
1943 /* If there is data waiting, eat it up */
1944 if (i->p && *i->p) {
1945 #if ENABLE_HUSH_INTERACTIVE
1949 if (i->eof_flag && !*i->p)
1951 /* note: ch is never NUL */
1953 /* need to double check i->file because we might be doing something
1954 * more complicated by now, like sourcing or substituting. */
1955 #if ENABLE_HUSH_INTERACTIVE
1956 if (G_interactive_fd && i->file == stdin) {
1959 } while (!*i->p); /* need non-empty line */
1960 i->promptmode = 1; /* PS2 */
1964 do ch = fgetc(i->file); while (ch == '\0');
1966 debug_printf("file_get: got '%c' %d\n", ch, ch);
1971 /* All callers guarantee this routine will never
1972 * be used right after a newline, so prompting is not needed.
1974 static int FAST_FUNC file_peek(struct in_str *i)
1977 if (i->p && *i->p) {
1978 if (i->eof_flag && !i->p[1])
1981 /* note: ch is never NUL */
1983 do ch = fgetc(i->file); while (ch == '\0');
1984 i->eof_flag = (ch == EOF);
1985 i->peek_buf[0] = ch;
1986 i->peek_buf[1] = '\0';
1988 debug_printf("file_peek: got '%c' %d\n", ch, ch);
1992 static void setup_file_in_str(struct in_str *i, FILE *f)
1994 memset(i, 0, sizeof(*i));
1995 i->peek = file_peek;
1997 /* i->promptmode = 0; - PS1 (memset did it) */
2002 static void setup_string_in_str(struct in_str *i, const char *s)
2004 memset(i, 0, sizeof(*i));
2005 i->peek = static_peek;
2006 i->get = static_get;
2007 /* i->promptmode = 0; - PS1 (memset did it) */
2009 /* i->eof_flag = 0; */
2016 #define B_CHUNK (32 * sizeof(char*))
2018 static void o_reset_to_empty_unquoted(o_string *o)
2021 o->has_quoted_part = 0;
2026 static void o_free(o_string *o)
2029 memset(o, 0, sizeof(*o));
2032 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2037 static void o_grow_by(o_string *o, int len)
2039 if (o->length + len > o->maxlen) {
2040 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2041 o->data = xrealloc(o->data, 1 + o->maxlen);
2045 static void o_addchr(o_string *o, int ch)
2047 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2049 o->data[o->length] = ch;
2051 o->data[o->length] = '\0';
2054 static void o_addblock(o_string *o, const char *str, int len)
2057 memcpy(&o->data[o->length], str, len);
2059 o->data[o->length] = '\0';
2062 static void o_addstr(o_string *o, const char *str)
2064 o_addblock(o, str, strlen(str));
2068 static void nommu_addchr(o_string *o, int ch)
2074 # define nommu_addchr(o, str) ((void)0)
2077 static void o_addstr_with_NUL(o_string *o, const char *str)
2079 o_addblock(o, str, strlen(str) + 1);
2083 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2084 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2085 * Apparently, on unquoted $v bash still does globbing
2086 * ("v='*.txt'; echo $v" prints all .txt files),
2087 * but NOT brace expansion! Thus, there should be TWO independent
2088 * quoting mechanisms on $v expansion side: one protects
2089 * $v from brace expansion, and other additionally protects "$v" against globbing.
2090 * We have only second one.
2093 #if ENABLE_HUSH_BRACE_EXPANSION
2094 # define MAYBE_BRACES "{}"
2096 # define MAYBE_BRACES ""
2099 /* My analysis of quoting semantics tells me that state information
2100 * is associated with a destination, not a source.
2102 static void o_addqchr(o_string *o, int ch)
2105 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2110 o->data[o->length] = '\\';
2113 o->data[o->length] = ch;
2115 o->data[o->length] = '\0';
2118 static void o_addQchr(o_string *o, int ch)
2121 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2122 && strchr("*?[\\" MAYBE_BRACES, ch)
2125 o->data[o->length] = '\\';
2129 o->data[o->length] = ch;
2131 o->data[o->length] = '\0';
2134 static void o_addqblock(o_string *o, const char *str, int len)
2139 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2140 if (ordinary_cnt > len) /* paranoia */
2142 o_addblock(o, str, ordinary_cnt);
2143 if (ordinary_cnt == len)
2145 str += ordinary_cnt;
2146 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2150 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2152 o->data[o->length] = '\\';
2156 o->data[o->length] = ch;
2158 o->data[o->length] = '\0';
2162 static void o_addQblock(o_string *o, const char *str, int len)
2164 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2165 o_addblock(o, str, len);
2168 o_addqblock(o, str, len);
2171 static void o_addQstr(o_string *o, const char *str)
2173 o_addQblock(o, str, strlen(str));
2176 /* A special kind of o_string for $VAR and `cmd` expansion.
2177 * It contains char* list[] at the beginning, which is grown in 16 element
2178 * increments. Actual string data starts at the next multiple of 16 * (char*).
2179 * list[i] contains an INDEX (int!) into this string data.
2180 * It means that if list[] needs to grow, data needs to be moved higher up
2181 * but list[i]'s need not be modified.
2182 * NB: remembering how many list[i]'s you have there is crucial.
2183 * o_finalize_list() operation post-processes this structure - calculates
2184 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2186 #if DEBUG_EXPAND || DEBUG_GLOB
2187 static void debug_print_list(const char *prefix, o_string *o, int n)
2189 char **list = (char**)o->data;
2190 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2194 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2195 prefix, list, n, string_start, o->length, o->maxlen,
2196 !!(o->o_expflags & EXP_FLAG_GLOB),
2198 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2201 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2202 o->data + (int)(uintptr_t)list[i] + string_start,
2203 o->data + (int)(uintptr_t)list[i] + string_start);
2207 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2209 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2213 # define debug_print_list(prefix, o, n) ((void)0)
2216 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2217 * in list[n] so that it points past last stored byte so far.
2218 * It returns n+1. */
2219 static int o_save_ptr_helper(o_string *o, int n)
2221 char **list = (char**)o->data;
2225 if (!o->has_empty_slot) {
2226 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2227 string_len = o->length - string_start;
2228 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2229 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2230 /* list[n] points to string_start, make space for 16 more pointers */
2231 o->maxlen += 0x10 * sizeof(list[0]);
2232 o->data = xrealloc(o->data, o->maxlen + 1);
2233 list = (char**)o->data;
2234 memmove(list + n + 0x10, list + n, string_len);
2235 o->length += 0x10 * sizeof(list[0]);
2237 debug_printf_list("list[%d]=%d string_start=%d\n",
2238 n, string_len, string_start);
2241 /* We have empty slot at list[n], reuse without growth */
2242 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2243 string_len = o->length - string_start;
2244 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2245 n, string_len, string_start);
2246 o->has_empty_slot = 0;
2248 list[n] = (char*)(uintptr_t)string_len;
2252 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2253 static int o_get_last_ptr(o_string *o, int n)
2255 char **list = (char**)o->data;
2256 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2258 return ((int)(uintptr_t)list[n-1]) + string_start;
2261 #if ENABLE_HUSH_BRACE_EXPANSION
2262 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2263 * first, it processes even {a} (no commas), second,
2264 * I didn't manage to make it return strings when they don't match
2265 * existing files. Need to re-implement it.
2269 static int glob_needed(const char *s)
2278 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2284 /* Return pointer to next closing brace or to comma */
2285 static const char *next_brace_sub(const char *cp)
2289 while (*cp != '\0') {
2296 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2302 return *cp != '\0' ? cp : NULL;
2304 /* Recursive brace globber. Note: may garble pattern[]. */
2305 static int glob_brace(char *pattern, o_string *o, int n)
2307 char *new_pattern_buf;
2314 debug_printf_glob("glob_brace('%s')\n", pattern);
2320 if (*begin == '{') {
2321 /* Find the first sub-pattern and at the same time
2322 * find the rest after the closing brace */
2323 next = next_brace_sub(begin);
2325 /* An illegal expression */
2329 /* "{abc}" with no commas - illegal
2330 * brace expr, disregard and skip it */
2336 if (*begin == '\\' && begin[1] != '\0')
2340 debug_printf_glob("begin:%s\n", begin);
2341 debug_printf_glob("next:%s\n", next);
2343 /* Now find the end of the whole brace expression */
2345 while (*rest != '}') {
2346 rest = next_brace_sub(rest);
2348 /* An illegal expression */
2351 debug_printf_glob("rest:%s\n", rest);
2353 rest_len = strlen(++rest) + 1;
2355 /* We are sure the brace expression is well-formed */
2357 /* Allocate working buffer large enough for our work */
2358 new_pattern_buf = xmalloc(strlen(pattern));
2360 /* We have a brace expression. BEGIN points to the opening {,
2361 * NEXT points past the terminator of the first element, and REST
2362 * points past the final }. We will accumulate result names from
2363 * recursive runs for each brace alternative in the buffer using
2368 /* Construct the new glob expression */
2371 mempcpy(new_pattern_buf,
2372 /* We know the prefix for all sub-patterns */
2373 pattern, begin - pattern),
2377 /* Note: glob_brace() may garble new_pattern_buf[].
2378 * That's why we re-copy prefix every time (1st memcpy above).
2380 n = glob_brace(new_pattern_buf, o, n);
2382 /* We saw the last entry */
2386 next = next_brace_sub(next);
2388 free(new_pattern_buf);
2396 memset(&globdata, 0, sizeof(globdata));
2397 gr = glob(pattern, 0, NULL, &globdata);
2398 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2400 if (gr == GLOB_NOMATCH) {
2401 globfree(&globdata);
2402 /* NB: garbles parameter */
2403 unbackslash(pattern);
2404 o_addstr_with_NUL(o, pattern);
2405 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2406 return o_save_ptr_helper(o, n);
2408 if (gr == GLOB_NOSPACE)
2409 bb_error_msg_and_die(bb_msg_memory_exhausted);
2410 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2411 * but we didn't specify it. Paranoia again. */
2412 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2414 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2415 char **argv = globdata.gl_pathv;
2417 o_addstr_with_NUL(o, *argv);
2418 n = o_save_ptr_helper(o, n);
2424 globfree(&globdata);
2428 /* Performs globbing on last list[],
2429 * saving each result as a new list[].
2431 static int perform_glob(o_string *o, int n)
2433 char *pattern, *copy;
2435 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2437 return o_save_ptr_helper(o, n);
2438 pattern = o->data + o_get_last_ptr(o, n);
2439 debug_printf_glob("glob pattern '%s'\n", pattern);
2440 if (!glob_needed(pattern)) {
2441 /* unbackslash last string in o in place, fix length */
2442 o->length = unbackslash(pattern) - o->data;
2443 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2444 return o_save_ptr_helper(o, n);
2447 copy = xstrdup(pattern);
2448 /* "forget" pattern in o */
2449 o->length = pattern - o->data;
2450 n = glob_brace(copy, o, n);
2453 debug_print_list("perform_glob returning", o, n);
2457 #else /* !HUSH_BRACE_EXPANSION */
2460 static int glob_needed(const char *s)
2469 if (*s == '*' || *s == '[' || *s == '?')
2475 /* Performs globbing on last list[],
2476 * saving each result as a new list[].
2478 static int perform_glob(o_string *o, int n)
2484 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2486 return o_save_ptr_helper(o, n);
2487 pattern = o->data + o_get_last_ptr(o, n);
2488 debug_printf_glob("glob pattern '%s'\n", pattern);
2489 if (!glob_needed(pattern)) {
2491 /* unbackslash last string in o in place, fix length */
2492 o->length = unbackslash(pattern) - o->data;
2493 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2494 return o_save_ptr_helper(o, n);
2497 memset(&globdata, 0, sizeof(globdata));
2498 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2499 * If we glob "*.\*" and don't find anything, we need
2500 * to fall back to using literal "*.*", but GLOB_NOCHECK
2501 * will return "*.\*"!
2503 gr = glob(pattern, 0, NULL, &globdata);
2504 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2506 if (gr == GLOB_NOMATCH) {
2507 globfree(&globdata);
2510 if (gr == GLOB_NOSPACE)
2511 bb_error_msg_and_die(bb_msg_memory_exhausted);
2512 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2513 * but we didn't specify it. Paranoia again. */
2514 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2516 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2517 char **argv = globdata.gl_pathv;
2518 /* "forget" pattern in o */
2519 o->length = pattern - o->data;
2521 o_addstr_with_NUL(o, *argv);
2522 n = o_save_ptr_helper(o, n);
2528 globfree(&globdata);
2530 debug_print_list("perform_glob returning", o, n);
2534 #endif /* !HUSH_BRACE_EXPANSION */
2536 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2537 * Otherwise, just finish current list[] and start new */
2538 static int o_save_ptr(o_string *o, int n)
2540 if (o->o_expflags & EXP_FLAG_GLOB) {
2541 /* If o->has_empty_slot, list[n] was already globbed
2542 * (if it was requested back then when it was filled)
2543 * so don't do that again! */
2544 if (!o->has_empty_slot)
2545 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2547 return o_save_ptr_helper(o, n);
2550 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2551 static char **o_finalize_list(o_string *o, int n)
2556 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2558 debug_print_list("finalized", o, n);
2559 debug_printf_expand("finalized n:%d\n", n);
2560 list = (char**)o->data;
2561 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2565 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2570 static void free_pipe_list(struct pipe *pi);
2572 /* Returns pi->next - next pipe in the list */
2573 static struct pipe *free_pipe(struct pipe *pi)
2578 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2579 for (i = 0; i < pi->num_cmds; i++) {
2580 struct command *command;
2581 struct redir_struct *r, *rnext;
2583 command = &pi->cmds[i];
2584 debug_printf_clean(" command %d:\n", i);
2585 if (command->argv) {
2589 for (a = 0, p = command->argv; *p; a++, p++) {
2590 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2593 free_strings(command->argv);
2594 //command->argv = NULL;
2596 /* not "else if": on syntax error, we may have both! */
2597 if (command->group) {
2598 debug_printf_clean(" begin group (cmd_type:%d)\n",
2600 free_pipe_list(command->group);
2601 debug_printf_clean(" end group\n");
2602 //command->group = NULL;
2604 /* else is crucial here.
2605 * If group != NULL, child_func is meaningless */
2606 #if ENABLE_HUSH_FUNCTIONS
2607 else if (command->child_func) {
2608 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2609 command->child_func->parent_cmd = NULL;
2613 free(command->group_as_string);
2614 //command->group_as_string = NULL;
2616 for (r = command->redirects; r; r = rnext) {
2617 debug_printf_clean(" redirect %d%s",
2618 r->rd_fd, redir_table[r->rd_type].descrip);
2619 /* guard against the case >$FOO, where foo is unset or blank */
2620 if (r->rd_filename) {
2621 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2622 free(r->rd_filename);
2623 //r->rd_filename = NULL;
2625 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2629 //command->redirects = NULL;
2631 free(pi->cmds); /* children are an array, they get freed all at once */
2635 //pi->cmdtext = NULL;
2643 static void free_pipe_list(struct pipe *pi)
2647 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2649 debug_printf_clean("pipe followup code %d\n", pi->followup);
2655 /*** Parsing routines ***/
2657 #ifndef debug_print_tree
2658 static void debug_print_tree(struct pipe *pi, int lvl)
2660 static const char *const PIPE[] = {
2666 static const char *RES[] = {
2667 [RES_NONE ] = "NONE" ,
2670 [RES_THEN ] = "THEN" ,
2671 [RES_ELIF ] = "ELIF" ,
2672 [RES_ELSE ] = "ELSE" ,
2675 # if ENABLE_HUSH_LOOPS
2676 [RES_FOR ] = "FOR" ,
2677 [RES_WHILE] = "WHILE",
2678 [RES_UNTIL] = "UNTIL",
2680 [RES_DONE ] = "DONE" ,
2682 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2685 # if ENABLE_HUSH_CASE
2686 [RES_CASE ] = "CASE" ,
2687 [RES_CASE_IN ] = "CASE_IN" ,
2688 [RES_MATCH] = "MATCH",
2689 [RES_CASE_BODY] = "CASE_BODY",
2690 [RES_ESAC ] = "ESAC" ,
2692 [RES_XXXX ] = "XXXX" ,
2693 [RES_SNTX ] = "SNTX" ,
2695 static const char *const CMDTYPE[] = {
2699 # if ENABLE_HUSH_FUNCTIONS
2708 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2709 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2711 while (prn < pi->num_cmds) {
2712 struct command *command = &pi->cmds[prn];
2713 char **argv = command->argv;
2715 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
2717 command->assignment_cnt);
2718 if (command->group) {
2719 fdprintf(2, " group %s: (argv=%p)%s%s\n",
2720 CMDTYPE[command->cmd_type],
2723 , " group_as_string:", command->group_as_string
2728 debug_print_tree(command->group, lvl+1);
2732 if (argv) while (*argv) {
2733 fdprintf(2, " '%s'", *argv);
2743 #endif /* debug_print_tree */
2745 static struct pipe *new_pipe(void)
2748 pi = xzalloc(sizeof(struct pipe));
2749 /*pi->followup = 0; - deliberately invalid value */
2750 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2754 /* Command (member of a pipe) is complete, or we start a new pipe
2755 * if ctx->command is NULL.
2756 * No errors possible here.
2758 static int done_command(struct parse_context *ctx)
2760 /* The command is really already in the pipe structure, so
2761 * advance the pipe counter and make a new, null command. */
2762 struct pipe *pi = ctx->pipe;
2763 struct command *command = ctx->command;
2766 if (IS_NULL_CMD(command)) {
2767 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2771 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2772 //debug_print_tree(ctx->list_head, 20);
2774 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2777 /* Only real trickiness here is that the uncommitted
2778 * command structure is not counted in pi->num_cmds. */
2779 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2780 ctx->command = command = &pi->cmds[pi->num_cmds];
2782 memset(command, 0, sizeof(*command));
2783 return pi->num_cmds; /* used only for 0/nonzero check */
2786 static void done_pipe(struct parse_context *ctx, pipe_style type)
2790 debug_printf_parse("done_pipe entered, followup %d\n", type);
2791 /* Close previous command */
2792 not_null = done_command(ctx);
2793 ctx->pipe->followup = type;
2795 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2796 ctx->ctx_inverted = 0;
2797 ctx->pipe->res_word = ctx->ctx_res_w;
2800 /* Without this check, even just <enter> on command line generates
2801 * tree of three NOPs (!). Which is harmless but annoying.
2802 * IOW: it is safe to do it unconditionally. */
2805 || ctx->ctx_res_w == RES_FI
2807 #if ENABLE_HUSH_LOOPS
2808 || ctx->ctx_res_w == RES_DONE
2809 || ctx->ctx_res_w == RES_FOR
2810 || ctx->ctx_res_w == RES_IN
2812 #if ENABLE_HUSH_CASE
2813 || ctx->ctx_res_w == RES_ESAC
2817 debug_printf_parse("done_pipe: adding new pipe: "
2818 "not_null:%d ctx->ctx_res_w:%d\n",
2819 not_null, ctx->ctx_res_w);
2821 ctx->pipe->next = new_p;
2823 /* RES_THEN, RES_DO etc are "sticky" -
2824 * they remain set for pipes inside if/while.
2825 * This is used to control execution.
2826 * RES_FOR and RES_IN are NOT sticky (needed to support
2827 * cases where variable or value happens to match a keyword):
2829 #if ENABLE_HUSH_LOOPS
2830 if (ctx->ctx_res_w == RES_FOR
2831 || ctx->ctx_res_w == RES_IN)
2832 ctx->ctx_res_w = RES_NONE;
2834 #if ENABLE_HUSH_CASE
2835 if (ctx->ctx_res_w == RES_MATCH)
2836 ctx->ctx_res_w = RES_CASE_BODY;
2837 if (ctx->ctx_res_w == RES_CASE)
2838 ctx->ctx_res_w = RES_CASE_IN;
2840 ctx->command = NULL; /* trick done_command below */
2841 /* Create the memory for command, roughly:
2842 * ctx->pipe->cmds = new struct command;
2843 * ctx->command = &ctx->pipe->cmds[0];
2846 //debug_print_tree(ctx->list_head, 10);
2848 debug_printf_parse("done_pipe return\n");
2851 static void initialize_context(struct parse_context *ctx)
2853 memset(ctx, 0, sizeof(*ctx));
2854 ctx->pipe = ctx->list_head = new_pipe();
2855 /* Create the memory for command, roughly:
2856 * ctx->pipe->cmds = new struct command;
2857 * ctx->command = &ctx->pipe->cmds[0];
2862 /* If a reserved word is found and processed, parse context is modified
2863 * and 1 is returned.
2866 struct reserved_combo {
2869 unsigned char assignment_flag;
2873 FLAG_END = (1 << RES_NONE ),
2875 FLAG_IF = (1 << RES_IF ),
2876 FLAG_THEN = (1 << RES_THEN ),
2877 FLAG_ELIF = (1 << RES_ELIF ),
2878 FLAG_ELSE = (1 << RES_ELSE ),
2879 FLAG_FI = (1 << RES_FI ),
2881 # if ENABLE_HUSH_LOOPS
2882 FLAG_FOR = (1 << RES_FOR ),
2883 FLAG_WHILE = (1 << RES_WHILE),
2884 FLAG_UNTIL = (1 << RES_UNTIL),
2885 FLAG_DO = (1 << RES_DO ),
2886 FLAG_DONE = (1 << RES_DONE ),
2887 FLAG_IN = (1 << RES_IN ),
2889 # if ENABLE_HUSH_CASE
2890 FLAG_MATCH = (1 << RES_MATCH),
2891 FLAG_ESAC = (1 << RES_ESAC ),
2893 FLAG_START = (1 << RES_XXXX ),
2896 static const struct reserved_combo* match_reserved_word(o_string *word)
2898 /* Mostly a list of accepted follow-up reserved words.
2899 * FLAG_END means we are done with the sequence, and are ready
2900 * to turn the compound list into a command.
2901 * FLAG_START means the word must start a new compound list.
2903 static const struct reserved_combo reserved_list[] = {
2905 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
2906 { "if", RES_IF, WORD_IS_KEYWORD, FLAG_THEN | FLAG_START },
2907 { "then", RES_THEN, WORD_IS_KEYWORD, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
2908 { "elif", RES_ELIF, WORD_IS_KEYWORD, FLAG_THEN },
2909 { "else", RES_ELSE, WORD_IS_KEYWORD, FLAG_FI },
2910 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
2912 # if ENABLE_HUSH_LOOPS
2913 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
2914 { "while", RES_WHILE, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2915 { "until", RES_UNTIL, WORD_IS_KEYWORD, FLAG_DO | FLAG_START },
2916 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
2917 { "do", RES_DO, WORD_IS_KEYWORD, FLAG_DONE },
2918 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
2920 # if ENABLE_HUSH_CASE
2921 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
2922 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
2925 const struct reserved_combo *r;
2927 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
2928 if (strcmp(word->data, r->literal) == 0)
2933 /* Return 0: not a keyword, 1: keyword
2935 static int reserved_word(o_string *word, struct parse_context *ctx)
2937 # if ENABLE_HUSH_CASE
2938 static const struct reserved_combo reserved_match = {
2939 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
2942 const struct reserved_combo *r;
2944 if (word->has_quoted_part)
2946 r = match_reserved_word(word);
2950 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
2951 # if ENABLE_HUSH_CASE
2952 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
2953 /* "case word IN ..." - IN part starts first MATCH part */
2954 r = &reserved_match;
2957 if (r->flag == 0) { /* '!' */
2958 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
2959 syntax_error("! ! command");
2960 ctx->ctx_res_w = RES_SNTX;
2962 ctx->ctx_inverted = 1;
2965 if (r->flag & FLAG_START) {
2966 struct parse_context *old;
2968 old = xmalloc(sizeof(*old));
2969 debug_printf_parse("push stack %p\n", old);
2970 *old = *ctx; /* physical copy */
2971 initialize_context(ctx);
2973 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
2974 syntax_error_at(word->data);
2975 ctx->ctx_res_w = RES_SNTX;
2978 /* "{...} fi" is ok. "{...} if" is not
2980 * if { echo foo; } then { echo bar; } fi */
2981 if (ctx->command->group)
2982 done_pipe(ctx, PIPE_SEQ);
2985 ctx->ctx_res_w = r->res;
2986 ctx->old_flag = r->flag;
2987 word->o_assignment = r->assignment_flag;
2989 if (ctx->old_flag & FLAG_END) {
2990 struct parse_context *old;
2992 done_pipe(ctx, PIPE_SEQ);
2993 debug_printf_parse("pop stack %p\n", ctx->stack);
2995 old->command->group = ctx->list_head;
2996 old->command->cmd_type = CMD_NORMAL;
2998 o_addstr(&old->as_string, ctx->as_string.data);
2999 o_free_unsafe(&ctx->as_string);
3000 old->command->group_as_string = xstrdup(old->as_string.data);
3001 debug_printf_parse("pop, remembering as:'%s'\n",
3002 old->command->group_as_string);
3004 *ctx = *old; /* physical copy */
3009 #endif /* HAS_KEYWORDS */
3011 /* Word is complete, look at it and update parsing context.
3012 * Normal return is 0. Syntax errors return 1.
3013 * Note: on return, word is reset, but not o_free'd!
3015 static int done_word(o_string *word, struct parse_context *ctx)
3017 struct command *command = ctx->command;
3019 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3020 if (word->length == 0 && !word->has_quoted_part) {
3021 debug_printf_parse("done_word return 0: true null, ignored\n");
3025 if (ctx->pending_redirect) {
3026 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3027 * only if run as "bash", not "sh" */
3028 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3030 * ...the word that follows the redirection operator
3031 * shall be subjected to tilde expansion, parameter expansion,
3032 * command substitution, arithmetic expansion, and quote
3033 * removal. Pathname expansion shall not be performed
3034 * on the word by a non-interactive shell; an interactive
3035 * shell may perform it, but shall do so only when
3036 * the expansion would result in one word."
3038 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3039 /* Cater for >\file case:
3040 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3041 * Same with heredocs:
3042 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3044 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3045 unbackslash(ctx->pending_redirect->rd_filename);
3046 /* Is it <<"HEREDOC"? */
3047 if (word->has_quoted_part) {
3048 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3051 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3052 ctx->pending_redirect = NULL;
3054 /* If this word wasn't an assignment, next ones definitely
3055 * can't be assignments. Even if they look like ones. */
3056 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3057 && word->o_assignment != WORD_IS_KEYWORD
3059 word->o_assignment = NOT_ASSIGNMENT;
3061 if (word->o_assignment == DEFINITELY_ASSIGNMENT)
3062 command->assignment_cnt++;
3063 word->o_assignment = MAYBE_ASSIGNMENT;
3067 # if ENABLE_HUSH_CASE
3068 if (ctx->ctx_dsemicolon
3069 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3071 /* already done when ctx_dsemicolon was set to 1: */
3072 /* ctx->ctx_res_w = RES_MATCH; */
3073 ctx->ctx_dsemicolon = 0;
3076 if (!command->argv /* if it's the first word... */
3077 # if ENABLE_HUSH_LOOPS
3078 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3079 && ctx->ctx_res_w != RES_IN
3081 # if ENABLE_HUSH_CASE
3082 && ctx->ctx_res_w != RES_CASE
3085 debug_printf_parse("checking '%s' for reserved-ness\n", word->data);
3086 if (reserved_word(word, ctx)) {
3087 o_reset_to_empty_unquoted(word);
3088 debug_printf_parse("done_word return %d\n",
3089 (ctx->ctx_res_w == RES_SNTX));
3090 return (ctx->ctx_res_w == RES_SNTX);
3092 # if ENABLE_HUSH_BASH_COMPAT
3093 if (strcmp(word->data, "[[") == 0) {
3094 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3100 if (command->group) {
3101 /* "{ echo foo; } echo bar" - bad */
3102 syntax_error_at(word->data);
3103 debug_printf_parse("done_word return 1: syntax error, "
3104 "groups and arglists don't mix\n");
3107 if (word->has_quoted_part
3108 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3109 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3110 /* (otherwise it's known to be not empty and is already safe) */
3112 /* exclude "$@" - it can expand to no word despite "" */
3113 char *p = word->data;
3114 while (p[0] == SPECIAL_VAR_SYMBOL
3115 && (p[1] & 0x7f) == '@'
3116 && p[2] == SPECIAL_VAR_SYMBOL
3120 if (p == word->data || p[0] != '\0') {
3121 /* saw no "$@", or not only "$@" but some
3122 * real text is there too */
3123 /* insert "empty variable" reference, this makes
3124 * e.g. "", $empty"" etc to not disappear */
3125 o_addchr(word, SPECIAL_VAR_SYMBOL);
3126 o_addchr(word, SPECIAL_VAR_SYMBOL);
3129 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3130 debug_print_strings("word appended to argv", command->argv);
3133 #if ENABLE_HUSH_LOOPS
3134 if (ctx->ctx_res_w == RES_FOR) {
3135 if (word->has_quoted_part
3136 || !is_well_formed_var_name(command->argv[0], '\0')
3138 /* bash says just "not a valid identifier" */
3139 syntax_error("not a valid identifier in for");
3142 /* Force FOR to have just one word (variable name) */
3143 /* NB: basically, this makes hush see "for v in ..."
3144 * syntax as if it is "for v; in ...". FOR and IN become
3145 * two pipe structs in parse tree. */
3146 done_pipe(ctx, PIPE_SEQ);
3149 #if ENABLE_HUSH_CASE
3150 /* Force CASE to have just one word */
3151 if (ctx->ctx_res_w == RES_CASE) {
3152 done_pipe(ctx, PIPE_SEQ);
3156 o_reset_to_empty_unquoted(word);
3158 debug_printf_parse("done_word return 0\n");
3163 /* Peek ahead in the input to find out if we have a "&n" construct,
3164 * as in "2>&1", that represents duplicating a file descriptor.
3166 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3167 * REDIRFD_SYNTAX_ERR if syntax error,
3168 * REDIRFD_TO_FILE if no & was seen,
3169 * or the number found.
3172 #define parse_redir_right_fd(as_string, input) \
3173 parse_redir_right_fd(input)
3175 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3181 return REDIRFD_TO_FILE;
3183 ch = i_getch(input); /* get the & */
3184 nommu_addchr(as_string, ch);
3187 ch = i_getch(input);
3188 nommu_addchr(as_string, ch);
3189 return REDIRFD_CLOSE;
3193 while (ch != EOF && isdigit(ch)) {
3194 d = d*10 + (ch-'0');
3196 ch = i_getch(input);
3197 nommu_addchr(as_string, ch);
3202 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3204 bb_error_msg("ambiguous redirect");
3205 return REDIRFD_SYNTAX_ERR;
3208 /* Return code is 0 normal, 1 if a syntax error is detected
3210 static int parse_redirect(struct parse_context *ctx,
3213 struct in_str *input)
3215 struct command *command = ctx->command;
3216 struct redir_struct *redir;
3217 struct redir_struct **redirp;
3220 dup_num = REDIRFD_TO_FILE;
3221 if (style != REDIRECT_HEREDOC) {
3222 /* Check for a '>&1' type redirect */
3223 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3224 if (dup_num == REDIRFD_SYNTAX_ERR)
3227 int ch = i_peek(input);
3228 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3229 if (dup_num) { /* <<-... */
3230 ch = i_getch(input);
3231 nommu_addchr(&ctx->as_string, ch);
3236 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3237 int ch = i_peek(input);
3239 /* >|FILE redirect ("clobbering" >).
3240 * Since we do not support "set -o noclobber" yet,
3241 * >| and > are the same for now. Just eat |.
3243 ch = i_getch(input);
3244 nommu_addchr(&ctx->as_string, ch);
3248 /* Create a new redir_struct and append it to the linked list */
3249 redirp = &command->redirects;
3250 while ((redir = *redirp) != NULL) {
3251 redirp = &(redir->next);
3253 *redirp = redir = xzalloc(sizeof(*redir));
3254 /* redir->next = NULL; */
3255 /* redir->rd_filename = NULL; */
3256 redir->rd_type = style;
3257 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3259 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3260 redir_table[style].descrip);
3262 redir->rd_dup = dup_num;
3263 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3264 /* Erik had a check here that the file descriptor in question
3265 * is legit; I postpone that to "run time"
3266 * A "-" representation of "close me" shows up as a -3 here */
3267 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3268 redir->rd_fd, redir->rd_dup);
3270 /* Set ctx->pending_redirect, so we know what to do at the
3271 * end of the next parsed word. */
3272 ctx->pending_redirect = redir;
3277 /* If a redirect is immediately preceded by a number, that number is
3278 * supposed to tell which file descriptor to redirect. This routine
3279 * looks for such preceding numbers. In an ideal world this routine
3280 * needs to handle all the following classes of redirects...
3281 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3282 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3283 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3284 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3286 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3288 * ... If n is quoted, the number shall not be recognized as part of
3289 * the redirection expression. For example:
3291 * writes the character 2 into file a"
3292 * We are getting it right by setting ->has_quoted_part on any \<char>
3294 * A -1 return means no valid number was found,
3295 * the caller should use the appropriate default for this redirection.
3297 static int redirect_opt_num(o_string *o)
3301 if (o->data == NULL)
3303 num = bb_strtou(o->data, NULL, 10);
3304 if (errno || num < 0)
3306 o_reset_to_empty_unquoted(o);
3311 #define fetch_till_str(as_string, input, word, skip_tabs) \
3312 fetch_till_str(input, word, skip_tabs)
3314 static char *fetch_till_str(o_string *as_string,
3315 struct in_str *input,
3319 o_string heredoc = NULL_O_STRING;
3321 int prev = 0; /* not \ */
3326 ch = i_getch(input);
3328 nommu_addchr(as_string, ch);
3329 if ((ch == '\n' || ch == EOF)
3330 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3332 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3333 heredoc.data[past_EOL] = '\0';
3334 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3335 return heredoc.data;
3337 while (ch == '\n') {
3338 o_addchr(&heredoc, ch);
3341 past_EOL = heredoc.length;
3343 ch = i_getch(input);
3345 nommu_addchr(as_string, ch);
3346 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3350 o_free_unsafe(&heredoc);
3353 o_addchr(&heredoc, ch);
3354 nommu_addchr(as_string, ch);
3355 if (prev == '\\' && ch == '\\')
3356 /* Correctly handle foo\\<eol> (not a line cont.) */
3357 prev = 0; /* not \ */
3363 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3364 * and load them all. There should be exactly heredoc_cnt of them.
3366 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3368 struct pipe *pi = ctx->list_head;
3370 while (pi && heredoc_cnt) {
3372 struct command *cmd = pi->cmds;
3374 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3376 cmd->argv ? cmd->argv[0] : "NONE");
3377 for (i = 0; i < pi->num_cmds; i++) {
3378 struct redir_struct *redir = cmd->redirects;
3380 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3381 i, cmd->argv ? cmd->argv[0] : "NONE");
3383 if (redir->rd_type == REDIRECT_HEREDOC) {
3386 redir->rd_type = REDIRECT_HEREDOC2;
3387 /* redir->rd_dup is (ab)used to indicate <<- */
3388 p = fetch_till_str(&ctx->as_string, input,
3389 redir->rd_filename, redir->rd_dup);
3391 syntax_error("unexpected EOF in here document");
3394 free(redir->rd_filename);
3395 redir->rd_filename = p;
3398 redir = redir->next;
3405 /* Should be 0. If it isn't, it's a parse error */
3407 bb_error_msg_and_die("heredoc BUG 2");
3413 static int run_list(struct pipe *pi);
3415 #define parse_stream(pstring, input, end_trigger) \
3416 parse_stream(input, end_trigger)
3418 static struct pipe *parse_stream(char **pstring,
3419 struct in_str *input,
3423 #if !ENABLE_HUSH_FUNCTIONS
3424 #define parse_group(dest, ctx, input, ch) \
3425 parse_group(ctx, input, ch)
3427 static int parse_group(o_string *dest, struct parse_context *ctx,
3428 struct in_str *input, int ch)
3430 /* dest contains characters seen prior to ( or {.
3431 * Typically it's empty, but for function defs,
3432 * it contains function name (without '()'). */
3433 struct pipe *pipe_list;
3435 struct command *command = ctx->command;
3437 debug_printf_parse("parse_group entered\n");
3438 #if ENABLE_HUSH_FUNCTIONS
3439 if (ch == '(' && !dest->has_quoted_part) {
3441 if (done_word(dest, ctx))
3444 goto skip; /* (... */
3445 if (command->argv[1]) { /* word word ... (... */
3446 syntax_error_unexpected_ch('(');
3449 /* it is "word(..." or "word (..." */
3451 ch = i_getch(input);
3452 while (ch == ' ' || ch == '\t');
3454 syntax_error_unexpected_ch(ch);
3457 nommu_addchr(&ctx->as_string, ch);
3459 ch = i_getch(input);
3460 while (ch == ' ' || ch == '\t' || ch == '\n');
3462 syntax_error_unexpected_ch(ch);
3465 nommu_addchr(&ctx->as_string, ch);
3466 command->cmd_type = CMD_FUNCDEF;
3471 #if 0 /* Prevented by caller */
3472 if (command->argv /* word [word]{... */
3473 || dest->length /* word{... */
3474 || dest->has_quoted_part /* ""{... */
3477 debug_printf_parse("parse_group return 1: "
3478 "syntax error, groups and arglists don't mix\n");
3483 #if ENABLE_HUSH_FUNCTIONS
3489 command->cmd_type = CMD_SUBSHELL;
3491 /* bash does not allow "{echo...", requires whitespace */
3492 ch = i_getch(input);
3493 if (ch != ' ' && ch != '\t' && ch != '\n') {
3494 syntax_error_unexpected_ch(ch);
3497 nommu_addchr(&ctx->as_string, ch);
3502 # define as_string NULL
3504 char *as_string = NULL;
3506 pipe_list = parse_stream(&as_string, input, endch);
3509 o_addstr(&ctx->as_string, as_string);
3511 /* empty ()/{} or parse error? */
3512 if (!pipe_list || pipe_list == ERR_PTR) {
3513 /* parse_stream already emitted error msg */
3516 debug_printf_parse("parse_group return 1: "
3517 "parse_stream returned %p\n", pipe_list);
3520 command->group = pipe_list;
3522 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3523 command->group_as_string = as_string;
3524 debug_printf_parse("end of group, remembering as:'%s'\n",
3525 command->group_as_string);
3529 debug_printf_parse("parse_group return 0\n");
3531 /* command remains "open", available for possible redirects */
3534 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3535 /* Subroutines for copying $(...) and `...` things */
3536 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3538 static int add_till_single_quote(o_string *dest, struct in_str *input)
3541 int ch = i_getch(input);
3543 syntax_error_unterm_ch('\'');
3551 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3552 static int add_till_double_quote(o_string *dest, struct in_str *input)
3555 int ch = i_getch(input);
3557 syntax_error_unterm_ch('"');
3562 if (ch == '\\') { /* \x. Copy both chars. */
3564 ch = i_getch(input);
3568 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
3573 //if (ch == '$') ...
3576 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3578 * "Within the backquoted style of command substitution, backslash
3579 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3580 * The search for the matching backquote shall be satisfied by the first
3581 * backquote found without a preceding backslash; during this search,
3582 * if a non-escaped backquote is encountered within a shell comment,
3583 * a here-document, an embedded command substitution of the $(command)
3584 * form, or a quoted string, undefined results occur. A single-quoted
3585 * or double-quoted string that begins, but does not end, within the
3586 * "`...`" sequence produces undefined results."
3588 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3590 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3593 int ch = i_getch(input);
3597 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3598 ch = i_getch(input);
3602 && (!in_dquote || ch != '"')
3604 o_addchr(dest, '\\');
3608 syntax_error_unterm_ch('`');
3614 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3615 * quoting and nested ()s.
3616 * "With the $(command) style of command substitution, all characters
3617 * following the open parenthesis to the matching closing parenthesis
3618 * constitute the command. Any valid shell script can be used for command,
3619 * except a script consisting solely of redirections which produces
3620 * unspecified results."
3622 * echo $(echo '(TEST)' BEST) (TEST) BEST
3623 * echo $(echo 'TEST)' BEST) TEST) BEST
3624 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3626 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3627 * can contain arbitrary constructs, just like $(cmd).
3628 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3629 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3631 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3632 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3635 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3636 # if ENABLE_HUSH_BASH_COMPAT
3637 char end_char2 = end_ch >> 8;
3639 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3642 ch = i_getch(input);
3644 syntax_error_unterm_ch(end_ch);
3647 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3650 /* we look for closing )) of $((EXPR)) */
3651 if (i_peek(input) == end_ch) {
3652 i_getch(input); /* eat second ')' */
3657 if (ch == '(' || ch == '{') {
3658 ch = (ch == '(' ? ')' : '}');
3659 if (!add_till_closing_bracket(dest, input, ch))
3665 if (!add_till_single_quote(dest, input))
3671 if (!add_till_double_quote(dest, input))
3677 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
3683 /* \x. Copy verbatim. Important for \(, \) */
3684 ch = i_getch(input);
3686 syntax_error_unterm_ch(')');
3695 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3697 /* Return code: 0 for OK, 1 for syntax error */
3699 #define parse_dollar(as_string, dest, input, quote_mask) \
3700 parse_dollar(dest, input, quote_mask)
3701 #define as_string NULL
3703 static int parse_dollar(o_string *as_string,
3705 struct in_str *input, unsigned char quote_mask)
3707 int ch = i_peek(input); /* first character after the $ */
3709 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3711 ch = i_getch(input);
3712 nommu_addchr(as_string, ch);
3714 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3716 debug_printf_parse(": '%c'\n", ch);
3717 o_addchr(dest, ch | quote_mask);
3720 if (!isalnum(ch) && ch != '_')
3722 ch = i_getch(input);
3723 nommu_addchr(as_string, ch);
3725 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3726 } else if (isdigit(ch)) {
3728 ch = i_getch(input);
3729 nommu_addchr(as_string, ch);
3730 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3731 debug_printf_parse(": '%c'\n", ch);
3732 o_addchr(dest, ch | quote_mask);
3733 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3734 } else switch (ch) {
3736 case '!': /* last bg pid */
3737 case '?': /* last exit code */
3738 case '#': /* number of args */
3739 case '*': /* args */
3740 case '@': /* args */
3741 goto make_one_char_var;
3743 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3745 ch = i_getch(input); /* eat '{' */
3746 nommu_addchr(as_string, ch);
3748 ch = i_getch(input); /* first char after '{' */
3749 /* It should be ${?}, or ${#var},
3750 * or even ${?+subst} - operator acting on a special variable,
3751 * or the beginning of variable name.
3754 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3757 syntax_error_unterm_str("${name}");
3758 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
3761 nommu_addchr(as_string, ch);
3764 /* It's possible to just call add_till_closing_bracket() at this point.
3765 * However, this regresses some of our testsuite cases
3766 * which check invalid constructs like ${%}.
3767 * Oh well... let's check that the var name part is fine... */
3773 debug_printf_parse(": '%c'\n", ch);
3775 ch = i_getch(input);
3776 nommu_addchr(as_string, ch);
3780 if (!isalnum(ch) && ch != '_') {
3782 unsigned char last_ch;
3783 /* handle parameter expansions
3784 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3786 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3787 goto bad_dollar_syntax;
3789 /* Eat everything until closing '}' (or ':') */
3791 if (ENABLE_HUSH_BASH_COMPAT
3793 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3795 /* It's ${var:N[:M]} thing */
3796 end_ch = '}' * 0x100 + ':';
3798 if (ENABLE_HUSH_BASH_COMPAT
3801 /* It's ${var/[/]pattern[/repl]} thing */
3802 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3804 nommu_addchr(as_string, '/');
3807 end_ch = '}' * 0x100 + '/';
3813 #if ENABLE_HUSH_DOLLAR_OPS
3814 last_ch = add_till_closing_bracket(dest, input, end_ch);
3815 if (last_ch == 0) /* error? */
3818 #error Simple code to only allow ${var} is not implemented
3821 o_addstr(as_string, dest->data + pos);
3822 o_addchr(as_string, last_ch);
3825 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
3826 /* close the first block: */
3827 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3828 /* while parsing N from ${var:N[:M]}
3829 * or pattern from ${var/[/]pattern[/repl]} */
3830 if ((end_ch & 0xff) == last_ch) {
3831 /* got ':' or '/'- parse the rest */
3836 if (end_ch == '}' * 0x100 + ':') {
3837 /* it's ${var:N} - emulate :999999999 */
3838 o_addstr(dest, "999999999");
3839 } /* else: it's ${var/[/]pattern} */
3844 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3847 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
3851 ch = i_getch(input);
3852 nommu_addchr(as_string, ch);
3853 # if ENABLE_SH_MATH_SUPPORT
3854 if (i_peek(input) == '(') {
3855 ch = i_getch(input);
3856 nommu_addchr(as_string, ch);
3857 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3858 o_addchr(dest, /*quote_mask |*/ '+');
3861 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
3862 return 0; /* error */
3864 o_addstr(as_string, dest->data + pos);
3865 o_addchr(as_string, ')');
3866 o_addchr(as_string, ')');
3868 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3872 # if ENABLE_HUSH_TICK
3873 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3874 o_addchr(dest, quote_mask | '`');
3877 if (!add_till_closing_bracket(dest, input, ')'))
3878 return 0; /* error */
3880 o_addstr(as_string, dest->data + pos);
3881 o_addchr(as_string, ')');
3883 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3889 ch = i_getch(input);
3890 nommu_addchr(as_string, ch);
3892 if (isalnum(ch)) { /* it's $_name or $_123 */
3897 /* TODO: $_ and $-: */
3898 /* $_ Shell or shell script name; or last argument of last command
3899 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
3900 * but in command's env, set to full pathname used to invoke it */
3901 /* $- Option flags set by set builtin or shell options (-i etc) */
3903 o_addQchr(dest, '$');
3905 debug_printf_parse("parse_dollar return 1 (ok)\n");
3911 # if ENABLE_HUSH_BASH_COMPAT
3912 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3913 encode_string(dest, input, dquote_end, process_bkslash)
3915 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
3916 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3917 encode_string(dest, input, dquote_end)
3919 #define as_string NULL
3923 # if ENABLE_HUSH_BASH_COMPAT
3924 /* all parameters are needed, no macro tricks */
3926 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
3927 encode_string(as_string, dest, input, dquote_end)
3930 static int encode_string(o_string *as_string,
3932 struct in_str *input,
3934 int process_bkslash)
3936 #if !ENABLE_HUSH_BASH_COMPAT
3937 const int process_bkslash = 1;
3943 ch = i_getch(input);
3945 nommu_addchr(as_string, ch);
3946 if (ch == dquote_end) { /* may be only '"' or EOF */
3947 debug_printf_parse("encode_string return 1 (ok)\n");
3950 /* note: can't move it above ch == dquote_end check! */
3952 syntax_error_unterm_ch('"');
3953 return 0; /* error */
3957 next = i_peek(input);
3959 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
3960 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
3961 if (process_bkslash && ch == '\\') {
3963 syntax_error("\\<eof>");
3967 * "The backslash retains its special meaning [in "..."]
3968 * only when followed by one of the following characters:
3969 * $, `, ", \, or <newline>. A double quote may be quoted
3970 * within double quotes by preceding it with a backslash."
3971 * NB: in (unquoted) heredoc, above does not apply to ",
3972 * therefore we check for it by "next == dquote_end" cond.
3974 if (next == dquote_end || strchr("$`\\\n", next)) {
3975 ch = i_getch(input); /* eat next */
3977 goto again; /* skip \<newline> */
3978 } /* else: ch remains == '\\', and we double it below: */
3979 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
3980 nommu_addchr(as_string, ch);
3984 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
3985 debug_printf_parse("encode_string return 0: "
3986 "parse_dollar returned 0 (error)\n");
3991 #if ENABLE_HUSH_TICK
3993 //unsigned pos = dest->length;
3994 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3995 o_addchr(dest, 0x80 | '`');
3996 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
3997 return 0; /* error */
3998 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3999 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4003 o_addQchr(dest, ch);
4009 * Scan input until EOF or end_trigger char.
4010 * Return a list of pipes to execute, or NULL on EOF
4011 * or if end_trigger character is met.
4012 * On syntax error, exit if shell is not interactive,
4013 * reset parsing machinery and start parsing anew,
4014 * or return ERR_PTR.
4016 static struct pipe *parse_stream(char **pstring,
4017 struct in_str *input,
4020 struct parse_context ctx;
4021 o_string dest = NULL_O_STRING;
4024 /* Single-quote triggers a bypass of the main loop until its mate is
4025 * found. When recursing, quote state is passed in via dest->o_expflags.
4027 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4028 end_trigger ? end_trigger : 'X');
4031 /* If very first arg is "" or '', dest.data may end up NULL.
4032 * Preventing this: */
4033 o_addchr(&dest, '\0');
4036 /* We used to separate words on $IFS here. This was wrong.
4037 * $IFS is used only for word splitting when $var is expanded,
4038 * here we should use blank chars as separators, not $IFS
4041 if (MAYBE_ASSIGNMENT != 0)
4042 dest.o_assignment = MAYBE_ASSIGNMENT;
4043 initialize_context(&ctx);
4046 const char *is_blank;
4047 const char *is_special;
4051 redir_type redir_style;
4053 ch = i_getch(input);
4054 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4055 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4060 syntax_error_unterm_str("here document");
4063 /* end_trigger == '}' case errors out earlier,
4064 * checking only ')' */
4065 if (end_trigger == ')') {
4066 syntax_error_unterm_ch('(');
4070 if (done_word(&dest, &ctx)) {
4074 done_pipe(&ctx, PIPE_SEQ);
4076 /* If we got nothing... */
4077 /* (this makes bare "&" cmd a no-op.
4078 * bash says: "syntax error near unexpected token '&'") */
4079 if (pi->num_cmds == 0
4080 IF_HAS_KEYWORDS( && pi->res_word == RES_NONE)
4086 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4088 *pstring = ctx.as_string.data;
4090 o_free_unsafe(&ctx.as_string);
4093 debug_printf_parse("parse_stream return %p\n", pi);
4096 nommu_addchr(&ctx.as_string, ch);
4100 next = i_peek(input);
4102 is_special = "{}<>;&|()#'" /* special outside of "str" */
4103 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4104 /* Are { and } special here? */
4105 if (ctx.command->argv /* word [word]{... - non-special */
4106 || dest.length /* word{... - non-special */
4107 || dest.has_quoted_part /* ""{... - non-special */
4108 || (next != ';' /* }; - special */
4109 && next != ')' /* }) - special */
4110 && next != '&' /* }& and }&& ... - special */
4111 && next != '|' /* }|| ... - special */
4112 && !strchr(defifs, next) /* {word - non-special */
4115 /* They are not special, skip "{}" */
4118 is_special = strchr(is_special, ch);
4119 is_blank = strchr(defifs, ch);
4121 if (!is_special && !is_blank) { /* ordinary char */
4123 o_addQchr(&dest, ch);
4124 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4125 || dest.o_assignment == WORD_IS_KEYWORD)
4127 && is_well_formed_var_name(dest.data, '=')
4129 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4135 if (done_word(&dest, &ctx)) {
4139 /* Is this a case when newline is simply ignored?
4141 * "cmd | <newline> cmd ..."
4142 * "case ... in <newline> word) ..."
4144 if (IS_NULL_CMD(ctx.command)
4145 && dest.length == 0 && !dest.has_quoted_part
4147 /* This newline can be ignored. But...
4148 * Without check #1, interactive shell
4149 * ignores even bare <newline>,
4150 * and shows the continuation prompt:
4151 * ps1_prompt$ <enter>
4152 * ps2> _ <=== wrong, should be ps1
4153 * Without check #2, "cmd & <newline>"
4154 * is similarly mistreated.
4155 * (BTW, this makes "cmd & cmd"
4156 * and "cmd && cmd" non-orthogonal.
4157 * Really, ask yourself, why
4158 * "cmd && <newline>" doesn't start
4159 * cmd but waits for more input?
4162 struct pipe *pi = ctx.list_head;
4163 if (pi->num_cmds != 0 /* check #1 */
4164 && pi->followup != PIPE_BG /* check #2 */
4169 /* Treat newline as a command separator. */
4170 done_pipe(&ctx, PIPE_SEQ);
4171 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4173 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4178 dest.o_assignment = MAYBE_ASSIGNMENT;
4180 /* note: if (is_blank) continue;
4181 * will still trigger for us */
4185 /* "cmd}" or "cmd }..." without semicolon or &:
4186 * } is an ordinary char in this case, even inside { cmd; }
4187 * Pathological example: { ""}; } should exec "}" cmd
4190 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4191 || dest.length != 0 /* word} */
4192 || dest.has_quoted_part /* ""} */
4196 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4197 goto skip_end_trigger;
4198 /* else: } does terminate a group */
4201 if (end_trigger && end_trigger == ch
4202 && (ch != ';' || heredoc_cnt == 0)
4203 #if ENABLE_HUSH_CASE
4205 || ctx.ctx_res_w != RES_MATCH
4206 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4211 /* This is technically valid:
4212 * { cat <<HERE; }; echo Ok
4216 * but we don't support this.
4217 * We require heredoc to be in enclosing {}/(),
4220 syntax_error_unterm_str("here document");
4223 if (done_word(&dest, &ctx)) {
4226 done_pipe(&ctx, PIPE_SEQ);
4227 dest.o_assignment = MAYBE_ASSIGNMENT;
4228 /* Do we sit outside of any if's, loops or case's? */
4230 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4234 debug_printf_parse("as_string '%s'\n", ctx.as_string.data);
4236 *pstring = ctx.as_string.data;
4238 o_free_unsafe(&ctx.as_string);
4241 debug_printf_parse("parse_stream return %p: "
4242 "end_trigger char found\n",
4244 return ctx.list_head;
4251 /* Catch <, > before deciding whether this word is
4252 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4255 redir_fd = redirect_opt_num(&dest);
4256 if (done_word(&dest, &ctx)) {
4259 redir_style = REDIRECT_OVERWRITE;
4261 redir_style = REDIRECT_APPEND;
4262 ch = i_getch(input);
4263 nommu_addchr(&ctx.as_string, ch);
4266 else if (next == '(') {
4267 syntax_error(">(process) not supported");
4271 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4273 continue; /* back to top of while (1) */
4275 redir_fd = redirect_opt_num(&dest);
4276 if (done_word(&dest, &ctx)) {
4279 redir_style = REDIRECT_INPUT;
4281 redir_style = REDIRECT_HEREDOC;
4283 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4284 ch = i_getch(input);
4285 nommu_addchr(&ctx.as_string, ch);
4286 } else if (next == '>') {
4287 redir_style = REDIRECT_IO;
4288 ch = i_getch(input);
4289 nommu_addchr(&ctx.as_string, ch);
4292 else if (next == '(') {
4293 syntax_error("<(process) not supported");
4297 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4299 continue; /* back to top of while (1) */
4301 if (dest.length == 0 && !dest.has_quoted_part) {
4302 /* skip "#comment" */
4305 if (ch == EOF || ch == '\n')
4308 /* note: we do not add it to &ctx.as_string */
4310 nommu_addchr(&ctx.as_string, '\n');
4311 continue; /* back to top of while (1) */
4316 /* It's "\<newline>" */
4318 /* Remove trailing '\' from ctx.as_string */
4319 ctx.as_string.data[--ctx.as_string.length] = '\0';
4321 ch = i_getch(input); /* eat it */
4322 continue; /* back to top of while (1) */
4327 if (dest.o_assignment == MAYBE_ASSIGNMENT
4328 /* check that we are not in word in "a=1 2>word b=1": */
4329 && !ctx.pending_redirect
4331 /* ch is a special char and thus this word
4332 * cannot be an assignment */
4333 dest.o_assignment = NOT_ASSIGNMENT;
4336 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4339 case '#': /* non-comment #: "echo a#b" etc */
4340 o_addQchr(&dest, ch);
4344 syntax_error("\\<eof>");
4347 ch = i_getch(input);
4348 /* note: ch != '\n' (that case does not reach this place) */
4349 o_addchr(&dest, '\\');
4350 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4351 o_addchr(&dest, ch);
4352 nommu_addchr(&ctx.as_string, ch);
4353 /* Example: echo Hello \2>file
4354 * we need to know that word 2 is quoted */
4355 dest.has_quoted_part = 1;
4358 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4359 debug_printf_parse("parse_stream parse error: "
4360 "parse_dollar returned 0 (error)\n");
4365 dest.has_quoted_part = 1;
4367 ch = i_getch(input);
4369 syntax_error_unterm_ch('\'');
4372 nommu_addchr(&ctx.as_string, ch);
4375 o_addqchr(&dest, ch);
4379 dest.has_quoted_part = 1;
4380 if (dest.o_assignment == NOT_ASSIGNMENT)
4381 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4382 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4384 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4386 #if ENABLE_HUSH_TICK
4390 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4391 o_addchr(&dest, '`');
4393 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4396 o_addstr(&ctx.as_string, dest.data + pos);
4397 o_addchr(&ctx.as_string, '`');
4399 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4400 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4405 #if ENABLE_HUSH_CASE
4408 if (done_word(&dest, &ctx)) {
4411 done_pipe(&ctx, PIPE_SEQ);
4412 #if ENABLE_HUSH_CASE
4413 /* Eat multiple semicolons, detect
4414 * whether it means something special */
4419 ch = i_getch(input);
4420 nommu_addchr(&ctx.as_string, ch);
4421 if (ctx.ctx_res_w == RES_CASE_BODY) {
4422 ctx.ctx_dsemicolon = 1;
4423 ctx.ctx_res_w = RES_MATCH;
4429 /* We just finished a cmd. New one may start
4430 * with an assignment */
4431 dest.o_assignment = MAYBE_ASSIGNMENT;
4434 if (done_word(&dest, &ctx)) {
4438 ch = i_getch(input);
4439 nommu_addchr(&ctx.as_string, ch);
4440 done_pipe(&ctx, PIPE_AND);
4442 done_pipe(&ctx, PIPE_BG);
4446 if (done_word(&dest, &ctx)) {
4449 #if ENABLE_HUSH_CASE
4450 if (ctx.ctx_res_w == RES_MATCH)
4451 break; /* we are in case's "word | word)" */
4453 if (next == '|') { /* || */
4454 ch = i_getch(input);
4455 nommu_addchr(&ctx.as_string, ch);
4456 done_pipe(&ctx, PIPE_OR);
4458 /* we could pick up a file descriptor choice here
4459 * with redirect_opt_num(), but bash doesn't do it.
4460 * "echo foo 2| cat" yields "foo 2". */
4463 o_reset_to_empty_unquoted(&ctx.as_string);
4468 #if ENABLE_HUSH_CASE
4469 /* "case... in [(]word)..." - skip '(' */
4470 if (ctx.ctx_res_w == RES_MATCH
4471 && ctx.command->argv == NULL /* not (word|(... */
4472 && dest.length == 0 /* not word(... */
4473 && dest.has_quoted_part == 0 /* not ""(... */
4479 if (parse_group(&dest, &ctx, input, ch) != 0) {
4484 #if ENABLE_HUSH_CASE
4485 if (ctx.ctx_res_w == RES_MATCH)
4489 /* proper use of this character is caught by end_trigger:
4490 * if we see {, we call parse_group(..., end_trigger='}')
4491 * and it will match } earlier (not here). */
4492 syntax_error_unexpected_ch(ch);
4496 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4502 struct parse_context *pctx;
4503 IF_HAS_KEYWORDS(struct parse_context *p2;)
4505 /* Clean up allocated tree.
4506 * Sample for finding leaks on syntax error recovery path.
4507 * Run it from interactive shell, watch pmap `pidof hush`.
4508 * while if false; then false; fi; do break; fi
4509 * Samples to catch leaks at execution:
4510 * while if (true | {true;}); then echo ok; fi; do break; done
4511 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4515 /* Update pipe/command counts,
4516 * otherwise freeing may miss some */
4517 done_pipe(pctx, PIPE_SEQ);
4518 debug_printf_clean("freeing list %p from ctx %p\n",
4519 pctx->list_head, pctx);
4520 debug_print_tree(pctx->list_head, 0);
4521 free_pipe_list(pctx->list_head);
4522 debug_printf_clean("freed list %p\n", pctx->list_head);
4524 o_free_unsafe(&pctx->as_string);
4526 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4530 IF_HAS_KEYWORDS(pctx = p2;)
4531 } while (HAS_KEYWORDS && pctx);
4532 /* Free text, clear all dest fields */
4535 G.last_exitcode = 1;
4536 /* If we are not in top-level parse, we return,
4537 * our caller will propagate error.
4549 /*** Execution routines ***/
4551 /* Expansion can recurse, need forward decls: */
4552 #if !ENABLE_HUSH_BASH_COMPAT
4553 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4554 #define expand_string_to_string(str, do_unbackslash) \
4555 expand_string_to_string(str)
4557 static char *expand_string_to_string(const char *str, int do_unbackslash);
4558 #if ENABLE_HUSH_TICK
4559 static int process_command_subs(o_string *dest, const char *s);
4562 /* expand_strvec_to_strvec() takes a list of strings, expands
4563 * all variable references within and returns a pointer to
4564 * a list of expanded strings, possibly with larger number
4565 * of strings. (Think VAR="a b"; echo $VAR).
4566 * This new list is allocated as a single malloc block.
4567 * NULL-terminated list of char* pointers is at the beginning of it,
4568 * followed by strings themselves.
4569 * Caller can deallocate entire list by single free(list). */
4571 /* A horde of its helpers come first: */
4573 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4575 while (--len >= 0) {
4578 #if ENABLE_HUSH_BRACE_EXPANSION
4579 if (c == '{' || c == '}') {
4580 /* { -> \{, } -> \} */
4582 /* And now we want to add { or } and continue:
4585 * luckily, just falling throught achieves this.
4591 /* \z -> \\\z; \<eol> -> \\<eol> */
4596 o_addchr(o, *str++);
4602 /* Store given string, finalizing the word and starting new one whenever
4603 * we encounter IFS char(s). This is used for expanding variable values.
4604 * End-of-string does NOT finalize word: think about 'echo -$VAR-' */
4605 static int expand_on_ifs(o_string *output, int n, const char *str)
4608 int word_len = strcspn(str, G.ifs);
4610 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4611 o_addblock(output, str, word_len);
4613 /* Protect backslashes against globbing up :)
4614 * Example: "v='\*'; echo b$v" prints "b\*"
4615 * (and does not try to glob on "*")
4617 o_addblock_duplicate_backslash(output, str, word_len);
4618 /*/ Why can't we do it easier? */
4619 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4620 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4624 if (!*str) /* EOL - do not finalize word */
4626 o_addchr(output, '\0');
4627 debug_print_list("expand_on_ifs", output, n);
4628 n = o_save_ptr(output, n);
4629 str += strspn(str, G.ifs); /* skip ifs chars */
4631 debug_print_list("expand_on_ifs[1]", output, n);
4635 /* Helper to expand $((...)) and heredoc body. These act as if
4636 * they are in double quotes, with the exception that they are not :).
4637 * Just the rules are similar: "expand only $var and `cmd`"
4639 * Returns malloced string.
4640 * As an optimization, we return NULL if expansion is not needed.
4642 #if !ENABLE_HUSH_BASH_COMPAT
4643 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4644 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4645 encode_then_expand_string(str)
4647 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4650 struct in_str input;
4651 o_string dest = NULL_O_STRING;
4653 if (!strchr(str, '$')
4654 && !strchr(str, '\\')
4655 #if ENABLE_HUSH_TICK
4656 && !strchr(str, '`')
4662 /* We need to expand. Example:
4663 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4665 setup_string_in_str(&input, str);
4666 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4667 //TODO: error check (encode_string returns 0 on error)?
4668 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4669 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4670 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4671 o_free_unsafe(&dest);
4675 #if ENABLE_SH_MATH_SUPPORT
4676 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4678 arith_state_t math_state;
4682 math_state.lookupvar = get_local_var_value;
4683 math_state.setvar = set_local_var_from_halves;
4684 //math_state.endofname = endofname;
4685 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4686 res = arith(&math_state, exp_str ? exp_str : arg);
4689 *errmsg_p = math_state.errmsg;
4690 if (math_state.errmsg)
4691 die_if_script(math_state.errmsg);
4696 #if ENABLE_HUSH_BASH_COMPAT
4697 /* ${var/[/]pattern[/repl]} helpers */
4698 static char *strstr_pattern(char *val, const char *pattern, int *size)
4701 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4702 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4709 /* Optimization: if "*pat" did not match the start of "string",
4710 * we know that "tring", "ring" etc will not match too:
4712 if (pattern[0] == '*')
4717 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4719 char *result = NULL;
4720 unsigned res_len = 0;
4721 unsigned repl_len = strlen(repl);
4725 char *s = strstr_pattern(val, pattern, &size);
4729 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4730 memcpy(result + res_len, val, s - val);
4732 strcpy(result + res_len, repl);
4733 res_len += repl_len;
4734 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4740 if (val[0] && result) {
4741 result = xrealloc(result, res_len + strlen(val) + 1);
4742 strcpy(result + res_len, val);
4743 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4745 debug_printf_varexp("result:'%s'\n", result);
4751 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4753 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4755 const char *val = NULL;
4756 char *to_be_freed = NULL;
4761 char exp_save = exp_save; /* for compiler */
4762 char *exp_saveptr; /* points to expansion operator */
4763 char *exp_word = exp_word; /* for compiler */
4766 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
4768 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
4770 first_char = arg[0] = arg0 & 0x7f;
4773 if (first_char == '#' /* ${#... */
4774 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
4776 /* It must be length operator: ${#var} */
4780 /* Maybe handle parameter expansion */
4781 if (exp_saveptr /* if 2nd char is one of expansion operators */
4782 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
4784 /* ${?:0}, ${#[:]%0} etc */
4785 exp_saveptr = var + 1;
4787 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
4788 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
4790 exp_op = exp_save = *exp_saveptr;
4792 exp_word = exp_saveptr + 1;
4793 if (exp_op == ':') {
4794 exp_op = *exp_word++;
4795 //TODO: try ${var:} and ${var:bogus} in non-bash config
4796 if (ENABLE_HUSH_BASH_COMPAT
4797 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
4799 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
4804 *exp_saveptr = '\0';
4805 } /* else: it's not an expansion op, but bare ${var} */
4808 /* Look up the variable in question */
4809 if (isdigit(var[0])) {
4810 /* parse_dollar should have vetted var for us */
4811 int n = xatoi_positive(var);
4812 if (n < G.global_argc)
4813 val = G.global_argv[n];
4814 /* else val remains NULL: $N with too big N */
4818 val = utoa(G.root_pid);
4820 case '!': /* bg pid */
4821 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
4823 case '?': /* exitcode */
4824 val = utoa(G.last_exitcode);
4826 case '#': /* argc */
4827 val = utoa(G.global_argc ? G.global_argc-1 : 0);
4830 val = get_local_var_value(var);
4834 /* Handle any expansions */
4835 if (exp_op == 'L') {
4836 debug_printf_expand("expand: length(%s)=", val);
4837 val = utoa(val ? strlen(val) : 0);
4838 debug_printf_expand("%s\n", val);
4839 } else if (exp_op) {
4840 if (exp_op == '%' || exp_op == '#') {
4841 /* Standard-mandated substring removal ops:
4842 * ${parameter%word} - remove smallest suffix pattern
4843 * ${parameter%%word} - remove largest suffix pattern
4844 * ${parameter#word} - remove smallest prefix pattern
4845 * ${parameter##word} - remove largest prefix pattern
4847 * Word is expanded to produce a glob pattern.
4848 * Then var's value is matched to it and matching part removed.
4850 if (val && val[0]) {
4854 unsigned scan_flags = pick_scan(exp_op, *exp_word);
4855 if (exp_op == *exp_word) /* ## or %% */
4857 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4859 exp_word = exp_exp_word;
4860 /* HACK ALERT. We depend here on the fact that
4861 * G.global_argv and results of utoa and get_local_var_value
4862 * are actually in writable memory:
4863 * scan_and_match momentarily stores NULs there. */
4865 loc = scan_and_match(t, exp_word, scan_flags);
4866 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
4867 // exp_op, t, exp_word, loc);
4869 if (loc) { /* match was found */
4870 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
4871 val = loc; /* take right part */
4873 val = to_be_freed = xstrndup(val, loc - val); /* left */
4877 #if ENABLE_HUSH_BASH_COMPAT
4878 else if (exp_op == '/' || exp_op == '\\') {
4879 /* It's ${var/[/]pattern[/repl]} thing.
4880 * Note that in encoded form it has TWO parts:
4881 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4882 * and if // is used, it is encoded as \:
4883 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
4885 /* Empty variable always gives nothing: */
4886 // "v=''; echo ${v/*/w}" prints "", not "w"
4887 if (val && val[0]) {
4888 /* pattern uses non-standard expansion.
4889 * repl should be unbackslashed and globbed
4890 * by the usual expansion rules:
4892 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
4893 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
4894 * v='a bz'; echo ${v/a*z/a*z} prints "az"
4895 * v='a bz'; echo ${v/a*z/\z} prints "z"
4896 * (note that a*z _pattern_ is never globbed!)
4898 char *pattern, *repl, *t;
4899 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
4901 pattern = xstrdup(exp_word);
4902 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
4903 *p++ = SPECIAL_VAR_SYMBOL;
4905 p = strchr(p, SPECIAL_VAR_SYMBOL);
4907 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
4908 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
4909 /* HACK ALERT. We depend here on the fact that
4910 * G.global_argv and results of utoa and get_local_var_value
4911 * are actually in writable memory:
4912 * replace_pattern momentarily stores NULs there. */
4914 to_be_freed = replace_pattern(t,
4916 (repl ? repl : exp_word),
4918 if (to_be_freed) /* at least one replace happened */
4925 else if (exp_op == ':') {
4926 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
4927 /* It's ${var:N[:M]} bashism.
4928 * Note that in encoded form it has TWO parts:
4929 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
4934 beg = expand_and_evaluate_arith(exp_word, &errmsg);
4937 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
4938 *p++ = SPECIAL_VAR_SYMBOL;
4940 p = strchr(p, SPECIAL_VAR_SYMBOL);
4942 len = expand_and_evaluate_arith(exp_word, &errmsg);
4945 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
4946 if (len >= 0) { /* bash compat: len < 0 is illegal */
4947 if (beg < 0) /* bash compat */
4949 debug_printf_varexp("from val:'%s'\n", val);
4950 if (len == 0 || !val || beg >= strlen(val)) {
4954 /* Paranoia. What if user entered 9999999999999
4955 * which fits in arith_t but not int? */
4958 val = to_be_freed = xstrndup(val + beg, len);
4960 debug_printf_varexp("val:'%s'\n", val);
4964 die_if_script("malformed ${%s:...}", var);
4967 } else { /* one of "-=+?" */
4968 /* Standard-mandated substitution ops:
4969 * ${var?word} - indicate error if unset
4970 * If var is unset, word (or a message indicating it is unset
4971 * if word is null) is written to standard error
4972 * and the shell exits with a non-zero exit status.
4973 * Otherwise, the value of var is substituted.
4974 * ${var-word} - use default value
4975 * If var is unset, word is substituted.
4976 * ${var=word} - assign and use default value
4977 * If var is unset, word is assigned to var.
4978 * In all cases, final value of var is substituted.
4979 * ${var+word} - use alternative value
4980 * If var is unset, null is substituted.
4981 * Otherwise, word is substituted.
4983 * Word is subjected to tilde expansion, parameter expansion,
4984 * command substitution, and arithmetic expansion.
4985 * If word is not needed, it is not expanded.
4987 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
4988 * but also treat null var as if it is unset.
4990 int use_word = (!val || ((exp_save == ':') && !val[0]));
4992 use_word = !use_word;
4993 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
4994 (exp_save == ':') ? "true" : "false", use_word);
4996 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4998 exp_word = to_be_freed;
4999 if (exp_op == '?') {
5000 /* mimic bash message */
5001 die_if_script("%s: %s",
5003 exp_word[0] ? exp_word : "parameter null or not set"
5005 //TODO: how interactive bash aborts expansion mid-command?
5010 if (exp_op == '=') {
5011 /* ${var=[word]} or ${var:=[word]} */
5012 if (isdigit(var[0]) || var[0] == '#') {
5013 /* mimic bash message */
5014 die_if_script("$%s: cannot assign in this way", var);
5017 char *new_var = xasprintf("%s=%s", var, val);
5018 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5022 } /* one of "-=+?" */
5024 *exp_saveptr = exp_save;
5030 *to_be_freed_pp = to_be_freed;
5034 /* Expand all variable references in given string, adding words to list[]
5035 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5036 * to be filled). This routine is extremely tricky: has to deal with
5037 * variables/parameters with whitespace, $* and $@, and constructs like
5038 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5039 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5041 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5042 * expansion of right-hand side of assignment == 1-element expand.
5044 char cant_be_null = 0; /* only bit 0x80 matters */
5047 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5048 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5049 debug_print_list("expand_vars_to_list", output, n);
5050 n = o_save_ptr(output, n);
5051 debug_print_list("expand_vars_to_list[0]", output, n);
5053 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5055 char *to_be_freed = NULL;
5056 const char *val = NULL;
5057 #if ENABLE_HUSH_TICK
5058 o_string subst_result = NULL_O_STRING;
5060 #if ENABLE_SH_MATH_SUPPORT
5061 char arith_buf[sizeof(arith_t)*3 + 2];
5063 o_addblock(output, arg, p - arg);
5064 debug_print_list("expand_vars_to_list[1]", output, n);
5066 p = strchr(p, SPECIAL_VAR_SYMBOL);
5068 /* Fetch special var name (if it is indeed one of them)
5069 * and quote bit, force the bit on if singleword expansion -
5070 * important for not getting v=$@ expand to many words. */
5071 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5073 /* Is this variable quoted and thus expansion can't be null?
5074 * "$@" is special. Even if quoted, it can still
5075 * expand to nothing (not even an empty string),
5076 * thus it is excluded. */
5077 if ((first_ch & 0x7f) != '@')
5078 cant_be_null |= first_ch;
5080 switch (first_ch & 0x7f) {
5081 /* Highest bit in first_ch indicates that var is double-quoted */
5085 if (!G.global_argv[1])
5088 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5089 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5090 while (G.global_argv[i]) {
5091 n = expand_on_ifs(output, n, G.global_argv[i]);
5092 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5093 if (G.global_argv[i++][0] && G.global_argv[i]) {
5094 /* this argv[] is not empty and not last:
5095 * put terminating NUL, start new word */
5096 o_addchr(output, '\0');
5097 debug_print_list("expand_vars_to_list[2]", output, n);
5098 n = o_save_ptr(output, n);
5099 debug_print_list("expand_vars_to_list[3]", output, n);
5103 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5104 * and in this case should treat it like '$*' - see 'else...' below */
5105 if (first_ch == ('@'|0x80) /* quoted $@ */
5106 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5109 o_addQstr(output, G.global_argv[i]);
5110 if (++i >= G.global_argc)
5112 o_addchr(output, '\0');
5113 debug_print_list("expand_vars_to_list[4]", output, n);
5114 n = o_save_ptr(output, n);
5116 } else { /* quoted $* (or v="$@" case): add as one word */
5118 o_addQstr(output, G.global_argv[i]);
5119 if (!G.global_argv[++i])
5122 o_addchr(output, G.ifs[0]);
5127 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5128 /* "Empty variable", used to make "" etc to not disappear */
5130 cant_be_null = 0x80;
5132 #if ENABLE_HUSH_TICK
5133 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5134 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5136 /* Can't just stuff it into output o_string,
5137 * expanded result may need to be globbed
5138 * and $IFS-splitted */
5139 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5140 G.last_exitcode = process_command_subs(&subst_result, arg);
5141 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5142 val = subst_result.data;
5145 #if ENABLE_SH_MATH_SUPPORT
5146 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5149 arg++; /* skip '+' */
5150 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5151 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5152 res = expand_and_evaluate_arith(arg, NULL);
5153 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5154 sprintf(arith_buf, ARITH_FMT, res);
5160 val = expand_one_var(&to_be_freed, arg, &p);
5161 IF_HUSH_TICK(store_val:)
5162 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5163 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5164 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5165 if (val && val[0]) {
5166 n = expand_on_ifs(output, n, val);
5169 } else { /* quoted $VAR, val will be appended below */
5170 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5171 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5175 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5177 if (val && val[0]) {
5178 o_addQstr(output, val);
5182 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5183 * Do the check to avoid writing to a const string. */
5184 if (*p != SPECIAL_VAR_SYMBOL)
5185 *p = SPECIAL_VAR_SYMBOL;
5187 #if ENABLE_HUSH_TICK
5188 o_free(&subst_result);
5191 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5194 debug_print_list("expand_vars_to_list[a]", output, n);
5195 /* this part is literal, and it was already pre-quoted
5196 * if needed (much earlier), do not use o_addQstr here! */
5197 o_addstr_with_NUL(output, arg);
5198 debug_print_list("expand_vars_to_list[b]", output, n);
5199 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5200 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5203 /* allow to reuse list[n] later without re-growth */
5204 output->has_empty_slot = 1;
5206 o_addchr(output, '\0');
5212 static char **expand_variables(char **argv, unsigned expflags)
5216 o_string output = NULL_O_STRING;
5218 output.o_expflags = expflags;
5222 n = expand_vars_to_list(&output, n, *argv);
5225 debug_print_list("expand_variables", &output, n);
5227 /* output.data (malloced in one block) gets returned in "list" */
5228 list = o_finalize_list(&output, n);
5229 debug_print_strings("expand_variables[1]", list);
5233 static char **expand_strvec_to_strvec(char **argv)
5235 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5238 #if ENABLE_HUSH_BASH_COMPAT
5239 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5241 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5245 /* Used for expansion of right hand of assignments,
5246 * $((...)), heredocs, variable espansion parts.
5248 * NB: should NOT do globbing!
5249 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5251 static char *expand_string_to_string(const char *str, int do_unbackslash)
5253 #if !ENABLE_HUSH_BASH_COMPAT
5254 const int do_unbackslash = 1;
5256 char *argv[2], **list;
5258 debug_printf_expand("string_to_string<='%s'\n", str);
5259 /* This is generally an optimization, but it also
5260 * handles "", which otherwise trips over !list[0] check below.
5261 * (is this ever happens that we actually get str="" here?)
5263 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5264 //TODO: Can use on strings with \ too, just unbackslash() them?
5265 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5266 return xstrdup(str);
5269 argv[0] = (char*)str;
5271 list = expand_variables(argv, do_unbackslash
5272 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5273 : EXP_FLAG_SINGLEWORD
5276 if (!list[0] || list[1])
5277 bb_error_msg_and_die("BUG in varexp2");
5278 /* actually, just move string 2*sizeof(char*) bytes back */
5279 overlapping_strcpy((char*)list, list[0]);
5281 unbackslash((char*)list);
5282 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5286 /* Used for "eval" builtin */
5287 static char* expand_strvec_to_string(char **argv)
5291 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5292 /* Convert all NULs to spaces */
5297 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5298 bb_error_msg_and_die("BUG in varexp3");
5299 /* bash uses ' ' regardless of $IFS contents */
5304 overlapping_strcpy((char*)list, list[0]);
5305 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5309 static char **expand_assignments(char **argv, int count)
5314 G.expanded_assignments = p = NULL;
5315 /* Expand assignments into one string each */
5316 for (i = 0; i < count; i++) {
5317 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5319 G.expanded_assignments = NULL;
5326 void re_execute_shell(char ***to_free, const char *s,
5327 char *g_argv0, char **g_argv,
5328 char **builtin_argv) NORETURN;
5330 static void reset_traps_to_defaults(void)
5332 /* This function is always called in a child shell
5333 * after fork (not vfork, NOMMU doesn't use this function).
5338 /* Child shells are not interactive.
5339 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5340 * Testcase: (while :; do :; done) + ^Z should background.
5341 * Same goes for SIGTERM, SIGHUP, SIGINT.
5343 if (!G.traps && !(G.non_DFL_mask & SPECIAL_INTERACTIVE_SIGS))
5344 return; /* already no traps and no SPECIAL_INTERACTIVE_SIGS */
5346 /* Switching off SPECIAL_INTERACTIVE_SIGS.
5347 * Stupid. It can be done with *single* &= op, but we can't use
5348 * the fact that G.blocked_set is implemented as a bitmask
5350 mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
5354 /* Careful. Only if no trap or trap is not "" */
5355 if (!G.traps || !G.traps[sig] || G.traps[sig][0])
5356 sigdelset(&G.blocked_set, sig);
5363 /* Our homegrown sig mask is saner to work with :) */
5364 G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5366 /* Resetting all traps to default except empty ones */
5367 mask = G.non_DFL_mask;
5368 if (G.traps) for (sig = 0; sig < NSIG; sig++, mask >>= 1) {
5369 if (!G.traps[sig] || !G.traps[sig][0])
5372 G.traps[sig] = NULL;
5373 /* There is no signal for 0 (EXIT) */
5376 /* There was a trap handler, we just removed it.
5377 * But if sig still has non-DFL handling,
5378 * we should not unblock the sig. */
5381 sigdelset(&G.blocked_set, sig);
5383 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
5388 static void re_execute_shell(char ***to_free, const char *s,
5389 char *g_argv0, char **g_argv,
5390 char **builtin_argv) NORETURN;
5391 static void re_execute_shell(char ***to_free, const char *s,
5392 char *g_argv0, char **g_argv,
5393 char **builtin_argv)
5395 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5396 /* delims + 2 * (number of bytes in printed hex numbers) */
5397 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5398 char *heredoc_argv[4];
5399 struct variable *cur;
5400 # if ENABLE_HUSH_FUNCTIONS
5401 struct function *funcp;
5405 unsigned long long empty_trap_mask;
5407 if (!g_argv0) { /* heredoc */
5408 argv = heredoc_argv;
5409 argv[0] = (char *) G.argv0_for_re_execing;
5410 argv[1] = (char *) "-<";
5411 argv[2] = (char *) s;
5413 pp = &argv[3]; /* used as pointer to empty environment */
5419 if (pp) while (*pp++)
5422 empty_trap_mask = 0;
5425 for (sig = 1; sig < NSIG; sig++) {
5426 if (G.traps[sig] && !G.traps[sig][0])
5427 empty_trap_mask |= 1LL << sig;
5431 sprintf(param_buf, NOMMU_HACK_FMT
5432 , (unsigned) G.root_pid
5433 , (unsigned) G.root_ppid
5434 , (unsigned) G.last_bg_pid
5435 , (unsigned) G.last_exitcode
5438 IF_HUSH_LOOPS(, G.depth_of_loop)
5440 # undef NOMMU_HACK_FMT
5441 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5442 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5445 for (cur = G.top_var; cur; cur = cur->next) {
5446 if (!cur->flg_export || cur->flg_read_only)
5449 # if ENABLE_HUSH_FUNCTIONS
5450 for (funcp = G.top_func; funcp; funcp = funcp->next)
5456 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5457 *pp++ = (char *) G.argv0_for_re_execing;
5459 for (cur = G.top_var; cur; cur = cur->next) {
5460 if (strcmp(cur->varstr, hush_version_str) == 0)
5462 if (cur->flg_read_only) {
5463 *pp++ = (char *) "-R";
5464 *pp++ = cur->varstr;
5465 } else if (!cur->flg_export) {
5466 *pp++ = (char *) "-V";
5467 *pp++ = cur->varstr;
5470 # if ENABLE_HUSH_FUNCTIONS
5471 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5472 *pp++ = (char *) "-F";
5473 *pp++ = funcp->name;
5474 *pp++ = funcp->body_as_string;
5477 /* We can pass activated traps here. Say, -Tnn:trap_string
5479 * However, POSIX says that subshells reset signals with traps
5481 * I tested bash-3.2 and it not only does that with true subshells
5482 * of the form ( list ), but with any forked children shells.
5483 * I set trap "echo W" WINCH; and then tried:
5485 * { echo 1; sleep 20; echo 2; } &
5486 * while true; do echo 1; sleep 20; echo 2; break; done &
5487 * true | { echo 1; sleep 20; echo 2; } | cat
5489 * In all these cases sending SIGWINCH to the child shell
5490 * did not run the trap. If I add trap "echo V" WINCH;
5491 * _inside_ group (just before echo 1), it works.
5493 * I conclude it means we don't need to pass active traps here.
5494 * Even if we would use signal handlers instead of signal masking
5495 * in order to implement trap handling,
5496 * exec syscall below resets signals to SIG_DFL for us.
5498 *pp++ = (char *) "-c";
5501 while (*++builtin_argv)
5502 *pp++ = *builtin_argv;
5503 *pp++ = (char *) "";
5508 /* *pp = NULL; - is already there */
5512 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5513 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
5514 execve(bb_busybox_exec_path, argv, pp);
5515 /* Fallback. Useful for init=/bin/hush usage etc */
5516 if (argv[0][0] == '/')
5517 execve(argv[0], argv, pp);
5518 xfunc_error_retval = 127;
5519 bb_error_msg_and_die("can't re-execute the shell");
5521 #endif /* !BB_MMU */
5524 static int run_and_free_list(struct pipe *pi);
5526 /* Executing from string: eval, sh -c '...'
5527 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5528 * end_trigger controls how often we stop parsing
5529 * NUL: parse all, execute, return
5530 * ';': parse till ';' or newline, execute, repeat till EOF
5532 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5534 /* Why we need empty flag?
5535 * An obscure corner case "false; ``; echo $?":
5536 * empty command in `` should still set $? to 0.
5537 * But we can't just set $? to 0 at the start,
5538 * this breaks "false; echo `echo $?`" case.
5542 struct pipe *pipe_list;
5544 #if ENABLE_HUSH_INTERACTIVE
5545 if (end_trigger == ';')
5546 inp->promptmode = 0; /* PS1 */
5548 pipe_list = parse_stream(NULL, inp, end_trigger);
5549 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
5550 /* If we are in "big" script
5551 * (not in `cmd` or something similar)...
5553 if (pipe_list == ERR_PTR && end_trigger == ';') {
5554 /* Discard cached input (rest of line) */
5555 int ch = inp->last_char;
5556 while (ch != EOF && ch != '\n') {
5557 //bb_error_msg("Discarded:'%c'", ch);
5562 /* This stream isn't empty */
5566 if (!pipe_list && empty)
5567 G.last_exitcode = 0;
5570 debug_print_tree(pipe_list, 0);
5571 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5572 run_and_free_list(pipe_list);
5574 #if ENABLE_HUSH_FUNCTIONS
5575 if (G.flag_return_in_progress == 1)
5581 static void parse_and_run_string(const char *s)
5583 struct in_str input;
5584 setup_string_in_str(&input, s);
5585 parse_and_run_stream(&input, '\0');
5588 static void parse_and_run_file(FILE *f)
5590 struct in_str input;
5591 setup_file_in_str(&input, f);
5592 parse_and_run_stream(&input, ';');
5595 #if ENABLE_HUSH_TICK
5596 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5601 char **to_free = NULL;
5605 pid = BB_MMU ? xfork() : xvfork();
5606 if (pid == 0) { /* child */
5607 disable_restore_tty_pgrp_on_exit();
5608 /* Process substitution is not considered to be usual
5609 * 'command execution'.
5610 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5617 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5618 close(channel[0]); /* NB: close _first_, then move fd! */
5619 xmove_fd(channel[1], 1);
5620 /* Prevent it from trying to handle ctrl-z etc */
5621 IF_HUSH_JOB(G.run_list_level = 1;)
5622 /* Awful hack for `trap` or $(trap).
5624 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5625 * contains an example where "trap" is executed in a subshell:
5627 * save_traps=$(trap)
5629 * eval "$save_traps"
5631 * Standard does not say that "trap" in subshell shall print
5632 * parent shell's traps. It only says that its output
5633 * must have suitable form, but then, in the above example
5634 * (which is not supposed to be normative), it implies that.
5636 * bash (and probably other shell) does implement it
5637 * (traps are reset to defaults, but "trap" still shows them),
5638 * but as a result, "trap" logic is hopelessly messed up:
5641 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5642 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5643 * # true | trap <--- trap is in subshell - no output (ditto)
5644 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5645 * trap -- 'echo Ho' SIGWINCH
5646 * # echo `(trap)` <--- in subshell in subshell - output
5647 * trap -- 'echo Ho' SIGWINCH
5648 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5649 * trap -- 'echo Ho' SIGWINCH
5651 * The rules when to forget and when to not forget traps
5652 * get really complex and nonsensical.
5654 * Our solution: ONLY bare $(trap) or `trap` is special.
5656 s = skip_whitespace(s);
5657 if (strncmp(s, "trap", 4) == 0
5658 && skip_whitespace(s + 4)[0] == '\0'
5660 static const char *const argv[] = { NULL, NULL };
5661 builtin_trap((char**)argv);
5662 exit(0); /* not _exit() - we need to fflush */
5665 reset_traps_to_defaults();
5666 parse_and_run_string(s);
5667 _exit(G.last_exitcode);
5669 /* We re-execute after vfork on NOMMU. This makes this script safe:
5670 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5671 * huge=`cat BIG` # was blocking here forever
5674 re_execute_shell(&to_free,
5684 # if ENABLE_HUSH_FAST
5686 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5687 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5688 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5690 enable_restore_tty_pgrp_on_exit();
5695 close_on_exec_on(channel[0]);
5696 return xfdopen_for_read(channel[0]);
5699 /* Return code is exit status of the process that is run. */
5700 static int process_command_subs(o_string *dest, const char *s)
5703 struct in_str pipe_str;
5705 int status, ch, eol_cnt;
5707 fp = generate_stream_from_string(s, &pid);
5709 /* Now send results of command back into original context */
5710 setup_file_in_str(&pipe_str, fp);
5712 while ((ch = i_getch(&pipe_str)) != EOF) {
5718 o_addchr(dest, '\n');
5721 o_addQchr(dest, ch);
5724 debug_printf("done reading from `cmd` pipe, closing it\n");
5726 /* We need to extract exitcode. Test case
5727 * "true; echo `sleep 1; false` $?"
5729 safe_waitpid(pid, &status, 0);
5730 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5731 return WEXITSTATUS(status);
5733 #endif /* ENABLE_HUSH_TICK */
5736 static void setup_heredoc(struct redir_struct *redir)
5738 struct fd_pair pair;
5741 /* the _body_ of heredoc (misleading field name) */
5742 const char *heredoc = redir->rd_filename;
5749 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
5750 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5754 len = strlen(heredoc);
5756 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
5758 xmove_fd(pair.rd, redir->rd_fd);
5760 /* Try writing without forking. Newer kernels have
5761 * dynamically growing pipes. Must use non-blocking write! */
5764 written = write(pair.wr, heredoc, len);
5775 ndelay_off(pair.wr);
5777 /* Okay, pipe buffer was not big enough */
5778 /* Note: we must not create a stray child (bastard? :)
5779 * for the unsuspecting parent process. Child creates a grandchild
5780 * and exits before parent execs the process which consumes heredoc
5781 * (that exec happens after we return from this function) */
5788 disable_restore_tty_pgrp_on_exit();
5789 pid = BB_MMU ? xfork() : xvfork();
5793 close(redir->rd_fd); /* read side of the pipe */
5795 full_write(pair.wr, heredoc, len); /* may loop or block */
5798 /* Delegate blocking writes to another process */
5799 xmove_fd(pair.wr, STDOUT_FILENO);
5800 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
5804 #if ENABLE_HUSH_FAST
5806 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5808 enable_restore_tty_pgrp_on_exit();
5814 wait(NULL); /* wait till child has died */
5817 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
5818 * and stderr if they are redirected. */
5819 static int setup_redirects(struct command *prog, int squirrel[])
5822 struct redir_struct *redir;
5824 for (redir = prog->redirects; redir; redir = redir->next) {
5825 if (redir->rd_type == REDIRECT_HEREDOC2) {
5826 /* rd_fd<<HERE case */
5827 if (squirrel && redir->rd_fd < 3
5828 && squirrel[redir->rd_fd] < 0
5830 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5832 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
5834 debug_printf_parse("set heredoc '%s'\n",
5835 redir->rd_filename);
5836 setup_heredoc(redir);
5840 if (redir->rd_dup == REDIRFD_TO_FILE) {
5841 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
5843 if (redir->rd_filename == NULL) {
5844 /* Something went wrong in the parse.
5845 * Pretend it didn't happen */
5846 bb_error_msg("bug in redirect parse");
5849 mode = redir_table[redir->rd_type].mode;
5850 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
5851 openfd = open_or_warn(p, mode);
5854 /* this could get lost if stderr has been redirected, but
5855 * bash and ash both lose it as well (though zsh doesn't!) */
5856 //what the above comment tries to say?
5860 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
5861 openfd = redir->rd_dup;
5864 if (openfd != redir->rd_fd) {
5865 if (squirrel && redir->rd_fd < 3
5866 && squirrel[redir->rd_fd] < 0
5868 squirrel[redir->rd_fd] = dup(redir->rd_fd);
5870 if (openfd == REDIRFD_CLOSE) {
5871 /* "n>-" means "close me" */
5872 close(redir->rd_fd);
5874 xdup2(openfd, redir->rd_fd);
5875 if (redir->rd_dup == REDIRFD_TO_FILE)
5883 static void restore_redirects(int squirrel[])
5886 for (i = 0; i < 3; i++) {
5889 /* We simply die on error */
5895 static char *find_in_path(const char *arg)
5898 const char *PATH = get_local_var_value("PATH");
5904 const char *end = strchrnul(PATH, ':');
5905 int sz = end - PATH; /* must be int! */
5909 ret = xasprintf("%.*s/%s", sz, PATH, arg);
5911 /* We have xxx::yyyy in $PATH,
5912 * it means "use current dir" */
5915 if (access(ret, F_OK) == 0)
5928 static const struct built_in_command *find_builtin_helper(const char *name,
5929 const struct built_in_command *x,
5930 const struct built_in_command *end)
5933 if (strcmp(name, x->b_cmd) != 0) {
5937 debug_printf_exec("found builtin '%s'\n", name);
5942 static const struct built_in_command *find_builtin1(const char *name)
5944 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
5946 static const struct built_in_command *find_builtin(const char *name)
5948 const struct built_in_command *x = find_builtin1(name);
5951 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
5954 #if ENABLE_HUSH_FUNCTIONS
5955 static struct function **find_function_slot(const char *name)
5957 struct function **funcpp = &G.top_func;
5959 if (strcmp(name, (*funcpp)->name) == 0) {
5962 funcpp = &(*funcpp)->next;
5967 static const struct function *find_function(const char *name)
5969 const struct function *funcp = *find_function_slot(name);
5971 debug_printf_exec("found function '%s'\n", name);
5975 /* Note: takes ownership on name ptr */
5976 static struct function *new_function(char *name)
5978 struct function **funcpp = find_function_slot(name);
5979 struct function *funcp = *funcpp;
5981 if (funcp != NULL) {
5982 struct command *cmd = funcp->parent_cmd;
5983 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
5985 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
5987 /* Note: if !funcp->body, do not free body_as_string!
5988 * This is a special case of "-F name body" function:
5989 * body_as_string was not malloced! */
5991 free_pipe_list(funcp->body);
5993 free(funcp->body_as_string);
5997 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
5998 cmd->argv[0] = funcp->name;
5999 cmd->group = funcp->body;
6001 cmd->group_as_string = funcp->body_as_string;
6005 debug_printf_exec("remembering new function '%s'\n", name);
6006 funcp = *funcpp = xzalloc(sizeof(*funcp));
6007 /*funcp->next = NULL;*/
6014 static void unset_func(const char *name)
6016 struct function **funcpp = find_function_slot(name);
6017 struct function *funcp = *funcpp;
6019 if (funcp != NULL) {
6020 debug_printf_exec("freeing function '%s'\n", funcp->name);
6021 *funcpp = funcp->next;
6022 /* funcp is unlinked now, deleting it.
6023 * Note: if !funcp->body, the function was created by
6024 * "-F name body", do not free ->body_as_string
6025 * and ->name as they were not malloced. */
6027 free_pipe_list(funcp->body);
6030 free(funcp->body_as_string);
6038 #define exec_function(to_free, funcp, argv) \
6039 exec_function(funcp, argv)
6041 static void exec_function(char ***to_free,
6042 const struct function *funcp,
6043 char **argv) NORETURN;
6044 static void exec_function(char ***to_free,
6045 const struct function *funcp,
6051 argv[0] = G.global_argv[0];
6052 G.global_argv = argv;
6056 /* On MMU, funcp->body is always non-NULL */
6057 n = run_list(funcp->body);
6061 re_execute_shell(to_free,
6062 funcp->body_as_string,
6069 static int run_function(const struct function *funcp, char **argv)
6075 save_and_replace_G_args(&sv, argv);
6077 /* "we are in function, ok to use return" */
6078 sv_flg = G.flag_return_in_progress;
6079 G.flag_return_in_progress = -1;
6080 # if ENABLE_HUSH_LOCAL
6081 G.func_nest_level++;
6084 /* On MMU, funcp->body is always non-NULL */
6087 /* Function defined by -F */
6088 parse_and_run_string(funcp->body_as_string);
6089 rc = G.last_exitcode;
6093 rc = run_list(funcp->body);
6096 # if ENABLE_HUSH_LOCAL
6098 struct variable *var;
6099 struct variable **var_pp;
6101 var_pp = &G.top_var;
6102 while ((var = *var_pp) != NULL) {
6103 if (var->func_nest_level < G.func_nest_level) {
6104 var_pp = &var->next;
6108 if (var->flg_export)
6109 bb_unsetenv(var->varstr);
6110 /* Remove from global list */
6111 *var_pp = var->next;
6117 G.func_nest_level--;
6120 G.flag_return_in_progress = sv_flg;
6122 restore_G_args(&sv, argv);
6126 #endif /* ENABLE_HUSH_FUNCTIONS */
6130 #define exec_builtin(to_free, x, argv) \
6131 exec_builtin(x, argv)
6133 #define exec_builtin(to_free, x, argv) \
6134 exec_builtin(to_free, argv)
6136 static void exec_builtin(char ***to_free,
6137 const struct built_in_command *x,
6138 char **argv) NORETURN;
6139 static void exec_builtin(char ***to_free,
6140 const struct built_in_command *x,
6146 rcode = x->b_function(argv);
6151 /* On NOMMU, we must never block!
6152 * Example: { sleep 99 | read line; } & echo Ok
6154 re_execute_shell(to_free,
6163 static void execvp_or_die(char **argv) NORETURN;
6164 static void execvp_or_die(char **argv)
6166 debug_printf_exec("execing '%s'\n", argv[0]);
6167 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6168 execvp(argv[0], argv);
6169 bb_perror_msg("can't execute '%s'", argv[0]);
6170 _exit(127); /* bash compat */
6173 #if ENABLE_HUSH_MODE_X
6174 static void dump_cmd_in_x_mode(char **argv)
6176 if (G_x_mode && argv) {
6177 /* We want to output the line in one write op */
6185 len += strlen(argv[n++]) + 1;
6191 p += sprintf(p, " %s", argv[n++]);
6199 # define dump_cmd_in_x_mode(argv) ((void)0)
6203 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6204 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6205 #define pseudo_exec(nommu_save, command, argv_expanded) \
6206 pseudo_exec(command, argv_expanded)
6209 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6211 * Don't exit() here. If you don't exec, use _exit instead.
6212 * The at_exit handlers apparently confuse the calling process,
6213 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6214 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6215 char **argv, int assignment_cnt,
6216 char **argv_expanded) NORETURN;
6217 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6218 char **argv, int assignment_cnt,
6219 char **argv_expanded)
6223 new_env = expand_assignments(argv, assignment_cnt);
6224 dump_cmd_in_x_mode(new_env);
6226 if (!argv[assignment_cnt]) {
6227 /* Case when we are here: ... | var=val | ...
6228 * (note that we do not exit early, i.e., do not optimize out
6229 * expand_assignments(): think about ... | var=`sleep 1` | ...
6231 free_strings(new_env);
6232 _exit(EXIT_SUCCESS);
6236 set_vars_and_save_old(new_env);
6237 free(new_env); /* optional */
6238 /* we can also destroy set_vars_and_save_old's return value,
6241 nommu_save->new_env = new_env;
6242 nommu_save->old_vars = set_vars_and_save_old(new_env);
6245 if (argv_expanded) {
6246 argv = argv_expanded;
6248 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6250 nommu_save->argv = argv;
6253 dump_cmd_in_x_mode(argv);
6255 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6256 if (strchr(argv[0], '/') != NULL)
6260 /* Check if the command matches any of the builtins.
6261 * Depending on context, this might be redundant. But it's
6262 * easier to waste a few CPU cycles than it is to figure out
6263 * if this is one of those cases.
6266 /* On NOMMU, it is more expensive to re-execute shell
6267 * just in order to run echo or test builtin.
6268 * It's better to skip it here and run corresponding
6269 * non-builtin later. */
6270 const struct built_in_command *x;
6271 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6273 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6276 #if ENABLE_HUSH_FUNCTIONS
6277 /* Check if the command matches any functions */
6279 const struct function *funcp = find_function(argv[0]);
6281 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6286 #if ENABLE_FEATURE_SH_STANDALONE
6287 /* Check if the command matches any busybox applets */
6289 int a = find_applet_by_name(argv[0]);
6291 # if BB_MMU /* see above why on NOMMU it is not allowed */
6292 if (APPLET_IS_NOEXEC(a)) {
6293 debug_printf_exec("running applet '%s'\n", argv[0]);
6294 run_applet_no_and_exit(a, argv);
6297 /* Re-exec ourselves */
6298 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6299 sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
6300 execv(bb_busybox_exec_path, argv);
6301 /* If they called chroot or otherwise made the binary no longer
6302 * executable, fall through */
6307 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6310 execvp_or_die(argv);
6313 /* Called after [v]fork() in run_pipe
6315 static void pseudo_exec(nommu_save_t *nommu_save,
6316 struct command *command,
6317 char **argv_expanded) NORETURN;
6318 static void pseudo_exec(nommu_save_t *nommu_save,
6319 struct command *command,
6320 char **argv_expanded)
6322 if (command->argv) {
6323 pseudo_exec_argv(nommu_save, command->argv,
6324 command->assignment_cnt, argv_expanded);
6327 if (command->group) {
6328 /* Cases when we are here:
6331 * ... | ( list ) | ...
6332 * ... | { list } | ...
6336 debug_printf_exec("pseudo_exec: run_list\n");
6337 reset_traps_to_defaults();
6338 rcode = run_list(command->group);
6339 /* OK to leak memory by not calling free_pipe_list,
6340 * since this process is about to exit */
6343 re_execute_shell(&nommu_save->argv_from_re_execing,
6344 command->group_as_string,
6351 /* Case when we are here: ... | >file */
6352 debug_printf_exec("pseudo_exec'ed null command\n");
6353 _exit(EXIT_SUCCESS);
6357 static const char *get_cmdtext(struct pipe *pi)
6363 /* This is subtle. ->cmdtext is created only on first backgrounding.
6364 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6365 * On subsequent bg argv is trashed, but we won't use it */
6368 argv = pi->cmds[0].argv;
6369 if (!argv || !argv[0]) {
6370 pi->cmdtext = xzalloc(1);
6376 len += strlen(*argv) + 1;
6380 argv = pi->cmds[0].argv;
6382 len = strlen(*argv);
6383 memcpy(p, *argv, len);
6391 static void insert_bg_job(struct pipe *pi)
6393 struct pipe *job, **jobp;
6396 /* Linear search for the ID of the job to use */
6398 for (job = G.job_list; job; job = job->next)
6399 if (job->jobid >= pi->jobid)
6400 pi->jobid = job->jobid + 1;
6402 /* Add job to the list of running jobs */
6404 while ((job = *jobp) != NULL)
6406 job = *jobp = xmalloc(sizeof(*job));
6408 *job = *pi; /* physical copy */
6410 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6411 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6412 for (i = 0; i < pi->num_cmds; i++) {
6413 job->cmds[i].pid = pi->cmds[i].pid;
6414 /* all other fields are not used and stay zero */
6416 job->cmdtext = xstrdup(get_cmdtext(pi));
6418 if (G_interactive_fd)
6419 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6420 G.last_jobid = job->jobid;
6423 static void remove_bg_job(struct pipe *pi)
6425 struct pipe *prev_pipe;
6427 if (pi == G.job_list) {
6428 G.job_list = pi->next;
6430 prev_pipe = G.job_list;
6431 while (prev_pipe->next != pi)
6432 prev_pipe = prev_pipe->next;
6433 prev_pipe->next = pi->next;
6436 G.last_jobid = G.job_list->jobid;
6441 /* Remove a backgrounded job */
6442 static void delete_finished_bg_job(struct pipe *pi)
6449 /* Check to see if any processes have exited -- if they
6450 * have, figure out why and see if a job has completed */
6451 static int checkjobs(struct pipe *fg_pipe)
6461 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6463 attributes = WUNTRACED;
6464 if (fg_pipe == NULL)
6465 attributes |= WNOHANG;
6468 #if ENABLE_HUSH_FAST
6469 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6470 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6471 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6472 /* There was neither fork nor SIGCHLD since last waitpid */
6473 /* Avoid doing waitpid syscall if possible */
6474 if (!G.we_have_children) {
6478 if (fg_pipe == NULL) { /* is WNOHANG set? */
6479 /* We have children, but they did not exit
6480 * or stop yet (we saw no SIGCHLD) */
6483 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6487 /* Do we do this right?
6488 * bash-3.00# sleep 20 | false
6490 * [3]+ Stopped sleep 20 | false
6491 * bash-3.00# echo $?
6492 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6493 * [hush 1.14.0: yes we do it right]
6500 #if ENABLE_HUSH_FAST
6501 i = G.count_SIGCHLD;
6503 childpid = waitpid(-1, &status, attributes);
6504 if (childpid <= 0) {
6505 if (childpid && errno != ECHILD)
6506 bb_perror_msg("waitpid");
6507 #if ENABLE_HUSH_FAST
6508 else { /* Until next SIGCHLD, waitpid's are useless */
6509 G.we_have_children = (childpid == 0);
6510 G.handled_SIGCHLD = i;
6511 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6516 dead = WIFEXITED(status) || WIFSIGNALED(status);
6519 if (WIFSTOPPED(status))
6520 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6521 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6522 if (WIFSIGNALED(status))
6523 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6524 childpid, WTERMSIG(status), WEXITSTATUS(status));
6525 if (WIFEXITED(status))
6526 debug_printf_jobs("pid %d exited, exitcode %d\n",
6527 childpid, WEXITSTATUS(status));
6529 /* Were we asked to wait for fg pipe? */
6531 i = fg_pipe->num_cmds;
6533 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6534 if (fg_pipe->cmds[i].pid != childpid)
6538 fg_pipe->cmds[i].pid = 0;
6539 fg_pipe->alive_cmds--;
6540 ex = WEXITSTATUS(status);
6541 /* bash prints killer signal's name for *last*
6542 * process in pipe (prints just newline for SIGINT/SIGPIPE).
6543 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6545 if (WIFSIGNALED(status)) {
6546 int sig = WTERMSIG(status);
6547 if (i == fg_pipe->num_cmds-1)
6548 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
6549 printf("%s\n", sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
6550 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
6551 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6552 * Maybe we need to use sig | 128? */
6555 fg_pipe->cmds[i].cmd_exitcode = ex;
6557 fg_pipe->cmds[i].is_stopped = 1;
6558 fg_pipe->stopped_cmds++;
6560 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6561 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6562 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6563 /* All processes in fg pipe have exited or stopped */
6564 i = fg_pipe->num_cmds;
6566 rcode = fg_pipe->cmds[i].cmd_exitcode;
6567 /* usually last process gives overall exitstatus,
6568 * but with "set -o pipefail", last *failed* process does */
6569 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6572 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6573 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6574 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6575 * and "killall -STOP cat" */
6576 if (G_interactive_fd) {
6578 if (fg_pipe->alive_cmds != 0)
6579 insert_bg_job(fg_pipe);
6583 if (fg_pipe->alive_cmds == 0)
6586 /* There are still running processes in the fg pipe */
6587 goto wait_more; /* do waitpid again */
6589 /* it wasnt fg_pipe, look for process in bg pipes */
6593 /* We asked to wait for bg or orphaned children */
6594 /* No need to remember exitcode in this case */
6595 for (pi = G.job_list; pi; pi = pi->next) {
6596 for (i = 0; i < pi->num_cmds; i++) {
6597 if (pi->cmds[i].pid == childpid)
6598 goto found_pi_and_prognum;
6601 /* Happens when shell is used as init process (init=/bin/sh) */
6602 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6603 continue; /* do waitpid again */
6605 found_pi_and_prognum:
6608 pi->cmds[i].pid = 0;
6610 if (!pi->alive_cmds) {
6611 if (G_interactive_fd)
6612 printf(JOB_STATUS_FORMAT, pi->jobid,
6613 "Done", pi->cmdtext);
6614 delete_finished_bg_job(pi);
6618 pi->cmds[i].is_stopped = 1;
6622 } /* while (waitpid succeeds)... */
6628 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6631 int rcode = checkjobs(fg_pipe);
6632 if (G_saved_tty_pgrp) {
6633 /* Job finished, move the shell to the foreground */
6634 p = getpgrp(); /* our process group id */
6635 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6636 tcsetpgrp(G_interactive_fd, p);
6642 /* Start all the jobs, but don't wait for anything to finish.
6645 * Return code is normally -1, when the caller has to wait for children
6646 * to finish to determine the exit status of the pipe. If the pipe
6647 * is a simple builtin command, however, the action is done by the
6648 * time run_pipe returns, and the exit code is provided as the
6651 * Returns -1 only if started some children. IOW: we have to
6652 * mask out retvals of builtins etc with 0xff!
6654 * The only case when we do not need to [v]fork is when the pipe
6655 * is single, non-backgrounded, non-subshell command. Examples:
6656 * cmd ; ... { list } ; ...
6657 * cmd && ... { list } && ...
6658 * cmd || ... { list } || ...
6659 * If it is, then we can run cmd as a builtin, NOFORK,
6660 * or (if SH_STANDALONE) an applet, and we can run the { list }
6661 * with run_list. If it isn't one of these, we fork and exec cmd.
6663 * Cases when we must fork:
6664 * non-single: cmd | cmd
6665 * backgrounded: cmd & { list } &
6666 * subshell: ( list ) [&]
6668 #if !ENABLE_HUSH_MODE_X
6669 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6670 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6672 static int redirect_and_varexp_helper(char ***new_env_p,
6673 struct variable **old_vars_p,
6674 struct command *command,
6676 char **argv_expanded)
6678 /* setup_redirects acts on file descriptors, not FILEs.
6679 * This is perfect for work that comes after exec().
6680 * Is it really safe for inline use? Experimentally,
6681 * things seem to work. */
6682 int rcode = setup_redirects(command, squirrel);
6684 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6685 *new_env_p = new_env;
6686 dump_cmd_in_x_mode(new_env);
6687 dump_cmd_in_x_mode(argv_expanded);
6689 *old_vars_p = set_vars_and_save_old(new_env);
6693 static NOINLINE int run_pipe(struct pipe *pi)
6695 static const char *const null_ptr = NULL;
6699 struct command *command;
6700 char **argv_expanded;
6702 /* it is not always needed, but we aim to smaller code */
6703 int squirrel[] = { -1, -1, -1 };
6706 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6709 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6710 * Result should be 3 lines: q w e, qwe, q w e
6712 G.ifs = get_local_var_value("IFS");
6716 IF_HUSH_JOB(pi->pgrp = -1;)
6717 pi->stopped_cmds = 0;
6718 command = &pi->cmds[0];
6719 argv_expanded = NULL;
6721 if (pi->num_cmds != 1
6722 || pi->followup == PIPE_BG
6723 || command->cmd_type == CMD_SUBSHELL
6730 debug_printf_exec(": group:%p argv:'%s'\n",
6731 command->group, command->argv ? command->argv[0] : "NONE");
6733 if (command->group) {
6734 #if ENABLE_HUSH_FUNCTIONS
6735 if (command->cmd_type == CMD_FUNCDEF) {
6736 /* "executing" func () { list } */
6737 struct function *funcp;
6739 funcp = new_function(command->argv[0]);
6740 /* funcp->name is already set to argv[0] */
6741 funcp->body = command->group;
6743 funcp->body_as_string = command->group_as_string;
6744 command->group_as_string = NULL;
6746 command->group = NULL;
6747 command->argv[0] = NULL;
6748 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
6749 funcp->parent_cmd = command;
6750 command->child_func = funcp;
6752 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
6754 return EXIT_SUCCESS;
6758 debug_printf("non-subshell group\n");
6759 rcode = 1; /* exitcode if redir failed */
6760 if (setup_redirects(command, squirrel) == 0) {
6761 debug_printf_exec(": run_list\n");
6762 rcode = run_list(command->group) & 0xff;
6764 restore_redirects(squirrel);
6765 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6767 debug_printf_exec("run_pipe: return %d\n", rcode);
6771 argv = command->argv ? command->argv : (char **) &null_ptr;
6773 const struct built_in_command *x;
6774 #if ENABLE_HUSH_FUNCTIONS
6775 const struct function *funcp;
6779 char **new_env = NULL;
6780 struct variable *old_vars = NULL;
6782 if (argv[command->assignment_cnt] == NULL) {
6783 /* Assignments, but no command */
6784 /* Ensure redirects take effect (that is, create files).
6785 * Try "a=t >file" */
6786 #if 0 /* A few cases in testsuite fail with this code. FIXME */
6787 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
6788 /* Set shell variables */
6792 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6793 /* Do we need to flag set_local_var() errors?
6794 * "assignment to readonly var" and "putenv error"
6799 /* Redirect error sets $? to 1. Otherwise,
6800 * if evaluating assignment value set $?, retain it.
6801 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6803 rcode = G.last_exitcode;
6804 /* Exit, _skipping_ variable restoring code: */
6805 goto clean_up_and_ret0;
6807 #else /* Older, bigger, but more correct code */
6809 rcode = setup_redirects(command, squirrel);
6810 restore_redirects(squirrel);
6811 /* Set shell variables */
6813 bb_putchar_stderr('+');
6815 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
6817 fprintf(stderr, " %s", p);
6818 debug_printf_exec("set shell var:'%s'->'%s'\n",
6820 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
6821 /* Do we need to flag set_local_var() errors?
6822 * "assignment to readonly var" and "putenv error"
6827 bb_putchar_stderr('\n');
6828 /* Redirect error sets $? to 1. Otherwise,
6829 * if evaluating assignment value set $?, retain it.
6830 * Try "false; q=`exit 2`; echo $?" - should print 2: */
6832 rcode = G.last_exitcode;
6833 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6835 debug_printf_exec("run_pipe: return %d\n", rcode);
6840 /* Expand the rest into (possibly) many strings each */
6841 #if ENABLE_HUSH_BASH_COMPAT
6842 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
6843 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
6847 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
6850 /* if someone gives us an empty string: `cmd with empty output` */
6851 if (!argv_expanded[0]) {
6852 free(argv_expanded);
6854 return G.last_exitcode;
6857 x = find_builtin(argv_expanded[0]);
6858 #if ENABLE_HUSH_FUNCTIONS
6861 funcp = find_function(argv_expanded[0]);
6865 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
6866 debug_printf("exec with redirects only\n");
6867 rcode = setup_redirects(command, NULL);
6868 goto clean_up_and_ret1;
6871 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6874 debug_printf_exec(": builtin '%s' '%s'...\n",
6875 x->b_cmd, argv_expanded[1]);
6877 rcode = x->b_function(argv_expanded) & 0xff;
6880 #if ENABLE_HUSH_FUNCTIONS
6882 # if ENABLE_HUSH_LOCAL
6883 struct variable **sv;
6884 sv = G.shadowed_vars_pp;
6885 G.shadowed_vars_pp = &old_vars;
6887 debug_printf_exec(": function '%s' '%s'...\n",
6888 funcp->name, argv_expanded[1]);
6889 rcode = run_function(funcp, argv_expanded) & 0xff;
6890 # if ENABLE_HUSH_LOCAL
6891 G.shadowed_vars_pp = sv;
6897 unset_vars(new_env);
6899 /* clean_up_and_ret0: */
6900 restore_redirects(squirrel);
6902 free(argv_expanded);
6903 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
6905 debug_printf_exec("run_pipe return %d\n", rcode);
6909 if (ENABLE_FEATURE_SH_NOFORK) {
6910 int n = find_applet_by_name(argv_expanded[0]);
6911 if (n >= 0 && APPLET_IS_NOFORK(n)) {
6912 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
6914 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
6915 argv_expanded[0], argv_expanded[1]);
6916 rcode = run_nofork_applet(n, argv_expanded);
6918 goto clean_up_and_ret;
6921 /* It is neither builtin nor applet. We must fork. */
6925 /* NB: argv_expanded may already be created, and that
6926 * might include `cmd` runs! Do not rerun it! We *must*
6927 * use argv_expanded if it's non-NULL */
6929 /* Going to fork a child per each pipe member */
6934 while (cmd_no < pi->num_cmds) {
6935 struct fd_pair pipefds;
6937 volatile nommu_save_t nommu_save;
6938 nommu_save.new_env = NULL;
6939 nommu_save.old_vars = NULL;
6940 nommu_save.argv = NULL;
6941 nommu_save.argv_from_re_execing = NULL;
6943 command = &pi->cmds[cmd_no];
6945 if (command->argv) {
6946 debug_printf_exec(": pipe member '%s' '%s'...\n",
6947 command->argv[0], command->argv[1]);
6949 debug_printf_exec(": pipe member with no argv\n");
6952 /* pipes are inserted between pairs of commands */
6955 if (cmd_no < pi->num_cmds)
6956 xpiped_pair(pipefds);
6958 command->pid = BB_MMU ? fork() : vfork();
6959 if (!command->pid) { /* child */
6961 disable_restore_tty_pgrp_on_exit();
6962 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6964 /* Every child adds itself to new process group
6965 * with pgid == pid_of_first_child_in_pipe */
6966 if (G.run_list_level == 1 && G_interactive_fd) {
6969 if (pgrp < 0) /* true for 1st process only */
6971 if (setpgid(0, pgrp) == 0
6972 && pi->followup != PIPE_BG
6973 && G_saved_tty_pgrp /* we have ctty */
6975 /* We do it in *every* child, not just first,
6977 tcsetpgrp(G_interactive_fd, pgrp);
6981 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
6982 /* 1st cmd in backgrounded pipe
6983 * should have its stdin /dev/null'ed */
6985 if (open(bb_dev_null, O_RDONLY))
6986 xopen("/", O_RDONLY);
6988 xmove_fd(next_infd, 0);
6990 xmove_fd(pipefds.wr, 1);
6993 /* Like bash, explicit redirects override pipes,
6994 * and the pipe fd is available for dup'ing. */
6995 if (setup_redirects(command, NULL))
6998 /* Restore default handlers just prior to exec */
6999 /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
7001 /* Stores to nommu_save list of env vars putenv'ed
7002 * (NOMMU, on MMU we don't need that) */
7003 /* cast away volatility... */
7004 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7005 /* pseudo_exec() does not return */
7008 /* parent or error */
7009 #if ENABLE_HUSH_FAST
7011 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7013 enable_restore_tty_pgrp_on_exit();
7015 /* Clean up after vforked child */
7016 free(nommu_save.argv);
7017 free(nommu_save.argv_from_re_execing);
7018 unset_vars(nommu_save.new_env);
7019 add_vars(nommu_save.old_vars);
7021 free(argv_expanded);
7022 argv_expanded = NULL;
7023 if (command->pid < 0) { /* [v]fork failed */
7024 /* Clearly indicate, was it fork or vfork */
7025 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7029 /* Second and next children need to know pid of first one */
7031 pi->pgrp = command->pid;
7037 if (cmd_no < pi->num_cmds)
7039 /* Pass read (output) pipe end to next iteration */
7040 next_infd = pipefds.rd;
7043 if (!pi->alive_cmds) {
7045 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7050 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7054 /* NB: called by pseudo_exec, and therefore must not modify any
7055 * global data until exec/_exit (we can be a child after vfork!) */
7056 static int run_list(struct pipe *pi)
7058 #if ENABLE_HUSH_CASE
7059 char *case_word = NULL;
7061 #if ENABLE_HUSH_LOOPS
7062 struct pipe *loop_top = NULL;
7063 char **for_lcur = NULL;
7064 char **for_list = NULL;
7066 smallint last_followup;
7068 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7069 smalluint cond_code = 0;
7071 enum { cond_code = 0 };
7074 smallint rword; /* RES_foo */
7075 smallint last_rword; /* ditto */
7078 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7081 #if ENABLE_HUSH_LOOPS
7082 /* Check syntax for "for" */
7085 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7086 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7088 /* current word is FOR or IN (BOLD in comments below) */
7089 if (cpipe->next == NULL) {
7090 syntax_error("malformed for");
7092 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7095 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7096 if (cpipe->next->res_word == RES_DO)
7098 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7099 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7100 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7102 syntax_error("malformed for");
7104 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7111 /* Past this point, all code paths should jump to ret: label
7112 * in order to return, no direct "return" statements please.
7113 * This helps to ensure that no memory is leaked. */
7121 last_rword = RES_XXXX;
7123 last_followup = PIPE_SEQ;
7124 rcode = G.last_exitcode;
7126 /* Go through list of pipes, (maybe) executing them. */
7127 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7131 IF_HAS_KEYWORDS(rword = pi->res_word;)
7132 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7133 rword, cond_code, last_rword);
7134 #if ENABLE_HUSH_LOOPS
7135 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7136 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7138 /* start of a loop: remember where loop starts */
7143 /* Still in the same "if...", "then..." or "do..." branch? */
7144 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7145 if ((rcode == 0 && last_followup == PIPE_OR)
7146 || (rcode != 0 && last_followup == PIPE_AND)
7148 /* It is "<true> || CMD" or "<false> && CMD"
7149 * and we should not execute CMD */
7150 debug_printf_exec("skipped cmd because of || or &&\n");
7151 last_followup = pi->followup;
7155 last_followup = pi->followup;
7156 IF_HAS_KEYWORDS(last_rword = rword;)
7159 if (rword == RES_THEN) {
7160 /* if false; then ... fi has exitcode 0! */
7161 G.last_exitcode = rcode = EXIT_SUCCESS;
7162 /* "if <false> THEN cmd": skip cmd */
7166 if (rword == RES_ELSE || rword == RES_ELIF) {
7167 /* "if <true> then ... ELSE/ELIF cmd":
7168 * skip cmd and all following ones */
7173 #if ENABLE_HUSH_LOOPS
7174 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7176 /* first loop through for */
7178 static const char encoded_dollar_at[] ALIGN1 = {
7179 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7180 }; /* encoded representation of "$@" */
7181 static const char *const encoded_dollar_at_argv[] = {
7182 encoded_dollar_at, NULL
7183 }; /* argv list with one element: "$@" */
7186 vals = (char**)encoded_dollar_at_argv;
7187 if (pi->next->res_word == RES_IN) {
7188 /* if no variable values after "in" we skip "for" */
7189 if (!pi->next->cmds[0].argv) {
7190 G.last_exitcode = rcode = EXIT_SUCCESS;
7191 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7194 vals = pi->next->cmds[0].argv;
7195 } /* else: "for var; do..." -> assume "$@" list */
7196 /* create list of variable values */
7197 debug_print_strings("for_list made from", vals);
7198 for_list = expand_strvec_to_strvec(vals);
7199 for_lcur = for_list;
7200 debug_print_strings("for_list", for_list);
7203 /* "for" loop is over, clean up */
7209 /* Insert next value from for_lcur */
7210 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7211 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7214 if (rword == RES_IN) {
7215 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7217 if (rword == RES_DONE) {
7218 continue; /* "done" has no cmds too */
7221 #if ENABLE_HUSH_CASE
7222 if (rword == RES_CASE) {
7223 case_word = expand_strvec_to_string(pi->cmds->argv);
7226 if (rword == RES_MATCH) {
7229 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7231 /* all prev words didn't match, does this one match? */
7232 argv = pi->cmds->argv;
7234 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7235 /* TODO: which FNM_xxx flags to use? */
7236 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7238 if (cond_code == 0) { /* match! we will execute this branch */
7239 free(case_word); /* make future "word)" stop */
7247 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7249 continue; /* not matched yet, skip this pipe */
7252 /* Just pressing <enter> in shell should check for jobs.
7253 * OTOH, in non-interactive shell this is useless
7254 * and only leads to extra job checks */
7255 if (pi->num_cmds == 0) {
7256 if (G_interactive_fd)
7257 goto check_jobs_and_continue;
7261 /* After analyzing all keywords and conditions, we decided
7262 * to execute this pipe. NB: have to do checkjobs(NULL)
7263 * after run_pipe to collect any background children,
7264 * even if list execution is to be stopped. */
7265 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7268 #if ENABLE_HUSH_LOOPS
7269 G.flag_break_continue = 0;
7271 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7273 /* We ran a builtin, function, or group.
7274 * rcode is already known
7275 * and we don't need to wait for anything. */
7276 G.last_exitcode = rcode;
7277 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7278 check_and_run_traps(0);
7279 #if ENABLE_HUSH_LOOPS
7280 /* Was it "break" or "continue"? */
7281 if (G.flag_break_continue) {
7282 smallint fbc = G.flag_break_continue;
7283 /* We might fall into outer *loop*,
7284 * don't want to break it too */
7286 G.depth_break_continue--;
7287 if (G.depth_break_continue == 0)
7288 G.flag_break_continue = 0;
7289 /* else: e.g. "continue 2" should *break* once, *then* continue */
7290 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7291 if (G.depth_break_continue != 0 || fbc == BC_BREAK)
7292 goto check_jobs_and_break;
7293 /* "continue": simulate end of loop */
7298 #if ENABLE_HUSH_FUNCTIONS
7299 if (G.flag_return_in_progress == 1) {
7300 /* same as "goto check_jobs_and_break" */
7305 } else if (pi->followup == PIPE_BG) {
7306 /* What does bash do with attempts to background builtins? */
7307 /* even bash 3.2 doesn't do that well with nested bg:
7308 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7309 * I'm NOT treating inner &'s as jobs */
7310 check_and_run_traps(0);
7312 if (G.run_list_level == 1)
7315 /* Last command's pid goes to $! */
7316 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7317 G.last_exitcode = rcode = EXIT_SUCCESS;
7318 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7321 if (G.run_list_level == 1 && G_interactive_fd) {
7322 /* Waits for completion, then fg's main shell */
7323 rcode = checkjobs_and_fg_shell(pi);
7324 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7325 check_and_run_traps(0);
7328 { /* This one just waits for completion */
7329 rcode = checkjobs(pi);
7330 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7331 check_and_run_traps(0);
7333 G.last_exitcode = rcode;
7337 /* Analyze how result affects subsequent commands */
7339 if (rword == RES_IF || rword == RES_ELIF)
7342 #if ENABLE_HUSH_LOOPS
7343 /* Beware of "while false; true; do ..."! */
7344 if (pi->next && pi->next->res_word == RES_DO) {
7345 if (rword == RES_WHILE) {
7347 /* "while false; do...done" - exitcode 0 */
7348 G.last_exitcode = rcode = EXIT_SUCCESS;
7349 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7350 goto check_jobs_and_break;
7353 if (rword == RES_UNTIL) {
7355 debug_printf_exec(": until expr is true: breaking\n");
7356 check_jobs_and_break:
7364 check_jobs_and_continue:
7371 #if ENABLE_HUSH_LOOPS
7376 #if ENABLE_HUSH_CASE
7380 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7384 /* Select which version we will use */
7385 static int run_and_free_list(struct pipe *pi)
7388 debug_printf_exec("run_and_free_list entered\n");
7389 if (!G.o_opt[OPT_O_NOEXEC]) {
7390 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7391 rcode = run_list(pi);
7393 /* free_pipe_list has the side effect of clearing memory.
7394 * In the long run that function can be merged with run_list,
7395 * but doing that now would hobble the debugging effort. */
7397 debug_printf_exec("run_and_free_list return %d\n", rcode);
7402 /* Called a few times only (or even once if "sh -c") */
7403 static void init_sigmasks(void)
7407 sigset_t old_blocked_set;
7409 if (!G.inherited_set_is_saved) {
7410 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
7411 G.inherited_set = G.blocked_set;
7413 old_blocked_set = G.blocked_set;
7415 mask = (1 << SIGQUIT);
7416 if (G_interactive_fd) {
7417 mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
7418 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7419 mask |= SPECIAL_JOB_SIGS;
7421 G.non_DFL_mask = mask;
7426 sigaddset(&G.blocked_set, sig);
7430 sigdelset(&G.blocked_set, SIGCHLD);
7432 if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
7433 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7435 /* POSIX allows shell to re-enable SIGCHLD
7436 * even if it was SIG_IGN on entry */
7437 #if ENABLE_HUSH_FAST
7438 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7439 if (!G.inherited_set_is_saved)
7440 signal(SIGCHLD, SIGCHLD_handler);
7442 if (!G.inherited_set_is_saved)
7443 signal(SIGCHLD, SIG_DFL);
7446 G.inherited_set_is_saved = 1;
7451 static void maybe_set_to_sigexit(int sig)
7453 void (*handler)(int);
7454 /* non_DFL_mask'ed signals are, well, masked,
7455 * no need to set handler for them.
7457 if (!((G.non_DFL_mask >> sig) & 1)) {
7458 handler = signal(sig, sigexit);
7459 if (handler == SIG_IGN) /* oops... restore back to IGN! */
7460 signal(sig, handler);
7463 /* Set handlers to restore tty pgrp and exit */
7464 static void set_fatal_handlers(void)
7466 /* We _must_ restore tty pgrp on fatal signals */
7468 maybe_set_to_sigexit(SIGILL );
7469 maybe_set_to_sigexit(SIGFPE );
7470 maybe_set_to_sigexit(SIGBUS );
7471 maybe_set_to_sigexit(SIGSEGV);
7472 maybe_set_to_sigexit(SIGTRAP);
7473 } /* else: hush is perfect. what SEGV? */
7474 maybe_set_to_sigexit(SIGABRT);
7475 /* bash 3.2 seems to handle these just like 'fatal' ones */
7476 maybe_set_to_sigexit(SIGPIPE);
7477 maybe_set_to_sigexit(SIGALRM);
7478 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
7479 * if we aren't interactive... but in this case
7480 * we never want to restore pgrp on exit, and this fn is not called */
7481 /*maybe_set_to_sigexit(SIGHUP );*/
7482 /*maybe_set_to_sigexit(SIGTERM);*/
7483 /*maybe_set_to_sigexit(SIGINT );*/
7487 static int set_mode(int state, char mode, const char *o_opt)
7492 G.o_opt[OPT_O_NOEXEC] = state;
7495 IF_HUSH_MODE_X(G_x_mode = state;)
7499 /* "set -+o" without parameter.
7500 * in bash, set -o produces this output:
7504 * We always use the second form.
7506 const char *p = o_opt_strings;
7509 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7515 idx = index_in_strings(o_opt_strings, o_opt);
7517 G.o_opt[idx] = state;
7521 return EXIT_FAILURE;
7523 return EXIT_SUCCESS;
7526 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7527 int hush_main(int argc, char **argv)
7530 unsigned builtin_argc;
7532 struct variable *cur_var;
7533 struct variable *shell_ver;
7536 if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, it is already done */
7537 G.last_exitcode = EXIT_SUCCESS;
7539 G.argv0_for_re_execing = argv[0];
7541 /* Deal with HUSH_VERSION */
7542 shell_ver = xzalloc(sizeof(*shell_ver));
7543 shell_ver->flg_export = 1;
7544 shell_ver->flg_read_only = 1;
7545 /* Code which handles ${var<op>...} needs writable values for all variables,
7546 * therefore we xstrdup: */
7547 shell_ver->varstr = xstrdup(hush_version_str);
7548 /* Create shell local variables from the values
7549 * currently living in the environment */
7550 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7551 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7552 G.top_var = shell_ver;
7553 cur_var = G.top_var;
7556 char *value = strchr(*e, '=');
7557 if (value) { /* paranoia */
7558 cur_var->next = xzalloc(sizeof(*cur_var));
7559 cur_var = cur_var->next;
7560 cur_var->varstr = *e;
7561 cur_var->max_len = strlen(*e);
7562 cur_var->flg_export = 1;
7566 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7567 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
7568 putenv(shell_ver->varstr);
7571 set_pwd_var(/*exp:*/ 1);
7572 /* bash also exports SHLVL and _,
7573 * and sets (but doesn't export) the following variables:
7575 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7576 * BASH_VERSION='3.2.0(1)-release'
7578 * MACHTYPE=i386-pc-linux-gnu
7580 * HOSTNAME=<xxxxxxxxxx>
7581 * PPID=<NNNNN> - we also do it elsewhere
7592 * PIPESTATUS=([0]="0")
7593 * HISTFILE=/<xxx>/.bash_history
7597 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7599 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7609 #if ENABLE_FEATURE_EDITING
7610 G.line_input_state = new_line_input_t(FOR_SHELL);
7611 # if defined MAX_HISTORY && MAX_HISTORY > 0 && ENABLE_HUSH_SAVEHISTORY
7613 const char *hp = get_local_var_value("HISTFILE");
7615 hp = get_local_var_value("HOME");
7617 G.line_input_state->hist_file = concat_path_file(hp, ".hush_history");
7618 //set_local_var(xasprintf("HISTFILE=%s", ...));
7625 G.global_argc = argc;
7626 G.global_argv = argv;
7627 /* Initialize some more globals to non-zero values */
7628 cmdedit_update_prompt();
7630 if (setjmp(die_jmp)) {
7631 /* xfunc has failed! die die die */
7632 /* no EXIT traps, this is an escape hatch! */
7634 hush_exit(xfunc_error_retval);
7637 /* Shell is non-interactive at first. We need to call
7638 * init_sigmasks() if we are going to execute "sh <script>",
7639 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7640 * If we later decide that we are interactive, we run init_sigmasks()
7641 * in order to intercept (more) signals.
7645 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7648 opt = getopt(argc, argv, "+c:xins"
7651 # if ENABLE_HUSH_FUNCTIONS
7661 * sh ... -c 'script'
7662 * sh ... -c 'script' ARG0 [ARG1...]
7663 * On NOMMU, if builtin_argc != 0,
7664 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7665 * "" needs to be replaced with NULL
7666 * and BARGV vector fed to builtin function.
7667 * Note: the form without ARG0 never happens:
7668 * sh ... -c 'builtin' BARGV... ""
7671 G.root_pid = getpid();
7672 G.root_ppid = getppid();
7674 G.global_argv = argv + optind;
7675 G.global_argc = argc - optind;
7677 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7678 const struct built_in_command *x;
7681 x = find_builtin(optarg);
7682 if (x) { /* paranoia */
7683 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7684 G.global_argv += builtin_argc;
7685 G.global_argv[-1] = NULL; /* replace "" */
7687 G.last_exitcode = x->b_function(argv + optind - 1);
7691 if (!G.global_argv[0]) {
7692 /* -c 'script' (no params): prevent empty $0 */
7693 G.global_argv--; /* points to argv[i] of 'script' */
7694 G.global_argv[0] = argv[0];
7696 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7698 parse_and_run_string(optarg);
7701 /* Well, we cannot just declare interactiveness,
7702 * we have to have some stuff (ctty, etc) */
7703 /* G_interactive_fd++; */
7706 /* "-s" means "read from stdin", but this is how we always
7707 * operate, so simply do nothing here. */
7710 case '<': /* "big heredoc" support */
7711 full_write1_str(optarg);
7714 unsigned long long empty_trap_mask;
7716 G.root_pid = bb_strtou(optarg, &optarg, 16);
7718 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7720 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7722 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7724 builtin_argc = bb_strtou(optarg, &optarg, 16);
7726 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7727 if (empty_trap_mask != 0) {
7730 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7731 for (sig = 1; sig < NSIG; sig++) {
7732 if (empty_trap_mask & (1LL << sig)) {
7733 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7734 sigaddset(&G.blocked_set, sig);
7737 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
7739 # if ENABLE_HUSH_LOOPS
7741 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7747 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7749 # if ENABLE_HUSH_FUNCTIONS
7751 struct function *funcp = new_function(optarg);
7752 /* funcp->name is already set to optarg */
7753 /* funcp->body is set to NULL. It's a special case. */
7754 funcp->body_as_string = argv[optind];
7762 if (set_mode(1, opt, NULL) == 0) /* no error */
7766 fprintf(stderr, "Usage: sh [FILE]...\n"
7767 " or: sh -c command [args]...\n\n");
7773 } /* option parsing loop */
7776 G.root_pid = getpid();
7777 G.root_ppid = getppid();
7780 /* If we are login shell... */
7781 if (argv[0] && argv[0][0] == '-') {
7783 debug_printf("sourcing /etc/profile\n");
7784 input = fopen_for_read("/etc/profile");
7785 if (input != NULL) {
7786 close_on_exec_on(fileno(input));
7788 parse_and_run_file(input);
7791 /* bash: after sourcing /etc/profile,
7792 * tries to source (in the given order):
7793 * ~/.bash_profile, ~/.bash_login, ~/.profile,
7794 * stopping on first found. --noprofile turns this off.
7795 * bash also sources ~/.bash_logout on exit.
7796 * If called as sh, skips .bash_XXX files.
7803 * "bash <script>" (which is never interactive (unless -i?))
7804 * sources $BASH_ENV here (without scanning $PATH).
7805 * If called as sh, does the same but with $ENV.
7807 debug_printf("running script '%s'\n", argv[optind]);
7808 G.global_argv = argv + optind;
7809 G.global_argc = argc - optind;
7810 input = xfopen_for_read(argv[optind]);
7811 close_on_exec_on(fileno(input));
7813 parse_and_run_file(input);
7814 #if ENABLE_FEATURE_CLEAN_UP
7820 /* Up to here, shell was non-interactive. Now it may become one.
7821 * NB: don't forget to (re)run init_sigmasks() as needed.
7824 /* A shell is interactive if the '-i' flag was given,
7825 * or if all of the following conditions are met:
7827 * no arguments remaining or the -s flag given
7828 * standard input is a terminal
7829 * standard output is a terminal
7830 * Refer to Posix.2, the description of the 'sh' utility.
7833 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7834 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
7835 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
7836 if (G_saved_tty_pgrp < 0)
7837 G_saved_tty_pgrp = 0;
7839 /* try to dup stdin to high fd#, >= 255 */
7840 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7841 if (G_interactive_fd < 0) {
7842 /* try to dup to any fd */
7843 G_interactive_fd = dup(STDIN_FILENO);
7844 if (G_interactive_fd < 0) {
7846 G_interactive_fd = 0;
7847 G_saved_tty_pgrp = 0;
7850 // TODO: track & disallow any attempts of user
7851 // to (inadvertently) close/redirect G_interactive_fd
7853 debug_printf("interactive_fd:%d\n", G_interactive_fd);
7854 if (G_interactive_fd) {
7855 close_on_exec_on(G_interactive_fd);
7857 if (G_saved_tty_pgrp) {
7858 /* If we were run as 'hush &', sleep until we are
7859 * in the foreground (tty pgrp == our pgrp).
7860 * If we get started under a job aware app (like bash),
7861 * make sure we are now in charge so we don't fight over
7862 * who gets the foreground */
7864 pid_t shell_pgrp = getpgrp();
7865 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
7866 if (G_saved_tty_pgrp == shell_pgrp)
7868 /* send TTIN to ourself (should stop us) */
7869 kill(- shell_pgrp, SIGTTIN);
7873 /* Block some signals */
7876 if (G_saved_tty_pgrp) {
7877 /* Set other signals to restore saved_tty_pgrp */
7878 set_fatal_handlers();
7879 /* Put ourselves in our own process group
7880 * (bash, too, does this only if ctty is available) */
7881 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
7882 /* Grab control of the terminal */
7883 tcsetpgrp(G_interactive_fd, getpid());
7885 /* -1 is special - makes xfuncs longjmp, not exit
7886 * (we reset die_sleep = 0 whereever we [v]fork) */
7887 enable_restore_tty_pgrp_on_exit(); /* sets die_sleep = -1 */
7891 #elif ENABLE_HUSH_INTERACTIVE
7892 /* No job control compiled in, only prompt/line editing */
7893 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
7894 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
7895 if (G_interactive_fd < 0) {
7896 /* try to dup to any fd */
7897 G_interactive_fd = dup(STDIN_FILENO);
7898 if (G_interactive_fd < 0)
7900 G_interactive_fd = 0;
7903 if (G_interactive_fd) {
7904 close_on_exec_on(G_interactive_fd);
7908 /* We have interactiveness code disabled */
7912 * if interactive but not a login shell, sources ~/.bashrc
7913 * (--norc turns this off, --rcfile <file> overrides)
7916 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
7917 /* note: ash and hush share this string */
7918 printf("\n\n%s %s\n"
7919 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
7922 "hush - the humble shell"
7926 parse_and_run_file(stdin);
7929 hush_exit(G.last_exitcode);
7934 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7935 int msh_main(int argc, char **argv)
7937 //bb_error_msg("msh is deprecated, please use hush instead");
7938 return hush_main(argc, argv);
7946 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
7951 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
7958 return applet_main_func(argc, argv - argc);
7961 static int FAST_FUNC builtin_test(char **argv)
7963 return run_applet_main(argv, test_main);
7966 static int FAST_FUNC builtin_echo(char **argv)
7968 return run_applet_main(argv, echo_main);
7972 static int FAST_FUNC builtin_printf(char **argv)
7974 return run_applet_main(argv, printf_main);
7978 static char **skip_dash_dash(char **argv)
7981 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
7986 static int FAST_FUNC builtin_eval(char **argv)
7988 int rcode = EXIT_SUCCESS;
7990 argv = skip_dash_dash(argv);
7992 char *str = expand_strvec_to_string(argv);
7994 * eval "echo Hi; done" ("done" is syntax error):
7995 * "echo Hi" will not execute too.
7997 parse_and_run_string(str);
7999 rcode = G.last_exitcode;
8004 static int FAST_FUNC builtin_cd(char **argv)
8008 argv = skip_dash_dash(argv);
8010 if (newdir == NULL) {
8011 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8012 * bash says "bash: cd: HOME not set" and does nothing
8015 const char *home = get_local_var_value("HOME");
8016 newdir = home ? home : "/";
8018 if (chdir(newdir)) {
8019 /* Mimic bash message exactly */
8020 bb_perror_msg("cd: %s", newdir);
8021 return EXIT_FAILURE;
8023 /* Read current dir (get_cwd(1) is inside) and set PWD.
8024 * Note: do not enforce exporting. If PWD was unset or unexported,
8025 * set it again, but do not export. bash does the same.
8027 set_pwd_var(/*exp:*/ 0);
8028 return EXIT_SUCCESS;
8031 static int FAST_FUNC builtin_exec(char **argv)
8033 argv = skip_dash_dash(argv);
8034 if (argv[0] == NULL)
8035 return EXIT_SUCCESS; /* bash does this */
8037 /* Careful: we can end up here after [v]fork. Do not restore
8038 * tty pgrp then, only top-level shell process does that */
8039 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8040 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8042 /* TODO: if exec fails, bash does NOT exit! We do.
8043 * We'll need to undo sigprocmask (it's inside execvp_or_die)
8044 * and tcsetpgrp, and this is inherently racy.
8046 execvp_or_die(argv);
8049 static int FAST_FUNC builtin_exit(char **argv)
8051 debug_printf_exec("%s()\n", __func__);
8053 /* interactive bash:
8054 * # trap "echo EEE" EXIT
8057 * There are stopped jobs.
8058 * (if there are _stopped_ jobs, running ones don't count)
8061 # EEE (then bash exits)
8063 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8066 /* note: EXIT trap is run by hush_exit */
8067 argv = skip_dash_dash(argv);
8068 if (argv[0] == NULL)
8069 hush_exit(G.last_exitcode);
8070 /* mimic bash: exit 123abc == exit 255 + error msg */
8071 xfunc_error_retval = 255;
8072 /* bash: exit -2 == exit 254, no error msg */
8073 hush_exit(xatoi(argv[0]) & 0xff);
8076 static void print_escaped(const char *s)
8081 const char *p = strchrnul(s, '\'');
8082 /* print 'xxxx', possibly just '' */
8083 printf("'%.*s'", (int)(p - s), s);
8088 /* s points to '; print "'''...'''" */
8090 do putchar('\''); while (*++s == '\'');
8095 #if !ENABLE_HUSH_LOCAL
8096 #define helper_export_local(argv, exp, lvl) \
8097 helper_export_local(argv, exp)
8099 static void helper_export_local(char **argv, int exp, int lvl)
8103 char *name_end = strchrnul(name, '=');
8105 /* So far we do not check that name is valid (TODO?) */
8107 if (*name_end == '\0') {
8108 struct variable *var, **vpp;
8110 vpp = get_ptr_to_local_var(name, name_end - name);
8111 var = vpp ? *vpp : NULL;
8113 if (exp == -1) { /* unexporting? */
8114 /* export -n NAME (without =VALUE) */
8116 var->flg_export = 0;
8117 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8119 } /* else: export -n NOT_EXISTING_VAR: no-op */
8122 if (exp == 1) { /* exporting? */
8123 /* export NAME (without =VALUE) */
8125 var->flg_export = 1;
8126 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8127 putenv(var->varstr);
8131 /* Exporting non-existing variable.
8132 * bash does not put it in environment,
8133 * but remembers that it is exported,
8134 * and does put it in env when it is set later.
8135 * We just set it to "" and export. */
8136 /* Or, it's "local NAME" (without =VALUE).
8137 * bash sets the value to "". */
8138 name = xasprintf("%s=", name);
8140 /* (Un)exporting/making local NAME=VALUE */
8141 name = xstrdup(name);
8143 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8147 static int FAST_FUNC builtin_export(char **argv)
8149 unsigned opt_unexport;
8151 #if ENABLE_HUSH_EXPORT_N
8152 /* "!": do not abort on errors */
8153 opt_unexport = getopt32(argv, "!n");
8154 if (opt_unexport == (uint32_t)-1)
8155 return EXIT_FAILURE;
8162 if (argv[0] == NULL) {
8169 /* ash emits: export VAR='VAL'
8170 * bash: declare -x VAR="VAL"
8171 * we follow ash example */
8172 const char *s = *e++;
8173 const char *p = strchr(s, '=');
8175 if (!p) /* wtf? take next variable */
8178 printf("export %.*s", (int)(p - s) + 1, s);
8179 print_escaped(p + 1);
8183 /*fflush_all(); - done after each builtin anyway */
8185 return EXIT_SUCCESS;
8188 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8190 return EXIT_SUCCESS;
8193 #if ENABLE_HUSH_LOCAL
8194 static int FAST_FUNC builtin_local(char **argv)
8196 if (G.func_nest_level == 0) {
8197 bb_error_msg("%s: not in a function", argv[0]);
8198 return EXIT_FAILURE; /* bash compat */
8200 helper_export_local(argv, 0, G.func_nest_level);
8201 return EXIT_SUCCESS;
8205 static int FAST_FUNC builtin_trap(char **argv)
8211 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8216 /* No args: print all trapped */
8217 for (i = 0; i < NSIG; ++i) {
8220 print_escaped(G.traps[i]);
8221 /* note: bash adds "SIG", but only if invoked
8222 * as "bash". If called as "sh", or if set -o posix,
8223 * then it prints short signal names.
8224 * We are printing short names: */
8225 printf(" %s\n", get_signame(i));
8228 /*fflush_all(); - done after each builtin anyway */
8229 return EXIT_SUCCESS;
8233 /* If first arg is a number: reset all specified signals */
8234 sig = bb_strtou(*argv, NULL, 10);
8240 sig = get_signum(*argv++);
8241 if (sig < 0 || sig >= NSIG) {
8243 /* Mimic bash message exactly */
8244 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8249 G.traps[sig] = xstrdup(new_cmd);
8251 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8252 get_signame(sig), sig, G.traps[sig]);
8254 /* There is no signal for 0 (EXIT) */
8259 sigaddset(&G.blocked_set, sig);
8261 /* There was a trap handler, we are removing it
8262 * (if sig has non-DFL handling,
8263 * we don't need to do anything) */
8264 if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
8266 sigdelset(&G.blocked_set, sig);
8269 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8273 if (!argv[1]) { /* no second arg */
8274 bb_error_msg("trap: invalid arguments");
8275 return EXIT_FAILURE;
8278 /* First arg is "-": reset all specified to default */
8279 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8280 /* Everything else: set arg as signal handler
8281 * (includes "" case, which ignores signal) */
8282 if (argv[0][0] == '-') {
8283 if (argv[0][1] == '\0') { /* "-" */
8284 /* new_cmd remains NULL: "reset these sigs" */
8287 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8290 /* else: "-something", no special meaning */
8295 goto process_sig_list;
8298 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8299 static int FAST_FUNC builtin_type(char **argv)
8301 int ret = EXIT_SUCCESS;
8307 if (0) {} /* make conditional compile easier below */
8308 /*else if (find_alias(*argv))
8309 type = "an alias";*/
8310 #if ENABLE_HUSH_FUNCTIONS
8311 else if (find_function(*argv))
8312 type = "a function";
8314 else if (find_builtin(*argv))
8315 type = "a shell builtin";
8316 else if ((path = find_in_path(*argv)) != NULL)
8319 bb_error_msg("type: %s: not found", *argv);
8324 printf("%s is %s\n", *argv, type);
8332 /* built-in 'fg' and 'bg' handler */
8333 static int FAST_FUNC builtin_fg_bg(char **argv)
8338 if (!G_interactive_fd)
8339 return EXIT_FAILURE;
8341 /* If they gave us no args, assume they want the last backgrounded task */
8343 for (pi = G.job_list; pi; pi = pi->next) {
8344 if (pi->jobid == G.last_jobid) {
8348 bb_error_msg("%s: no current job", argv[0]);
8349 return EXIT_FAILURE;
8351 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8352 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8353 return EXIT_FAILURE;
8355 for (pi = G.job_list; pi; pi = pi->next) {
8356 if (pi->jobid == jobnum) {
8360 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8361 return EXIT_FAILURE;
8363 /* TODO: bash prints a string representation
8364 * of job being foregrounded (like "sleep 1 | cat") */
8365 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8366 /* Put the job into the foreground. */
8367 tcsetpgrp(G_interactive_fd, pi->pgrp);
8370 /* Restart the processes in the job */
8371 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8372 for (i = 0; i < pi->num_cmds; i++) {
8373 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8374 pi->cmds[i].is_stopped = 0;
8376 pi->stopped_cmds = 0;
8378 i = kill(- pi->pgrp, SIGCONT);
8380 if (errno == ESRCH) {
8381 delete_finished_bg_job(pi);
8382 return EXIT_SUCCESS;
8384 bb_perror_msg("kill (SIGCONT)");
8387 if (argv[0][0] == 'f') {
8389 return checkjobs_and_fg_shell(pi);
8391 return EXIT_SUCCESS;
8395 #if ENABLE_HUSH_HELP
8396 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8398 const struct built_in_command *x;
8401 "Built-in commands:\n"
8402 "------------------\n");
8403 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8405 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8408 return EXIT_SUCCESS;
8413 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8416 const char *status_string;
8418 for (job = G.job_list; job; job = job->next) {
8419 if (job->alive_cmds == job->stopped_cmds)
8420 status_string = "Stopped";
8422 status_string = "Running";
8424 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8426 return EXIT_SUCCESS;
8431 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8436 # ifdef M_TRIM_THRESHOLD
8437 /* Optional. Reduces probability of false positives */
8440 /* Crude attempt to find where "free memory" starts,
8441 * sans fragmentation. */
8443 l = (unsigned long)p;
8446 if (l < (unsigned long)p) l = (unsigned long)p;
8449 if (!G.memleak_value)
8450 G.memleak_value = l;
8452 l -= G.memleak_value;
8459 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8464 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8467 return EXIT_SUCCESS;
8470 static int FAST_FUNC builtin_read(char **argv)
8479 /* "!": do not abort on errors.
8480 * Option string must start with "sr" to match BUILTIN_READ_xxx
8482 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8483 if (read_flags == (uint32_t)-1)
8484 return EXIT_FAILURE;
8487 r = shell_builtin_read(set_local_var_from_halves,
8489 get_local_var_value("IFS"), /* can be NULL */
8497 if ((uintptr_t)r > 1) {
8498 bb_error_msg("%s", r);
8499 r = (char*)(uintptr_t)1;
8502 return (uintptr_t)r;
8505 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8506 * built-in 'set' handler
8508 * set [-abCefhmnuvx] [-o option] [argument...]
8509 * set [+abCefhmnuvx] [+o option] [argument...]
8510 * set -- [argument...]
8513 * Implementations shall support the options in both their hyphen and
8514 * plus-sign forms. These options can also be specified as options to sh.
8516 * Write out all variables and their values: set
8517 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8518 * Turn on the -x and -v options: set -xv
8519 * Unset all positional parameters: set --
8520 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8521 * Set the positional parameters to the expansion of x, even if x expands
8522 * with a leading '-' or '+': set -- $x
8524 * So far, we only support "set -- [argument...]" and some of the short names.
8526 static int FAST_FUNC builtin_set(char **argv)
8529 char **pp, **g_argv;
8530 char *arg = *++argv;
8534 for (e = G.top_var; e; e = e->next)
8536 return EXIT_SUCCESS;
8540 if (strcmp(arg, "--") == 0) {
8544 if (arg[0] != '+' && arg[0] != '-')
8546 for (n = 1; arg[n]; ++n) {
8547 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8549 if (arg[n] == 'o' && argv[1])
8552 } while ((arg = *++argv) != NULL);
8553 /* Now argv[0] is 1st argument */
8556 return EXIT_SUCCESS;
8559 /* NB: G.global_argv[0] ($0) is never freed/changed */
8560 g_argv = G.global_argv;
8561 if (G.global_args_malloced) {
8567 G.global_args_malloced = 1;
8568 pp = xzalloc(sizeof(pp[0]) * 2);
8569 pp[0] = g_argv[0]; /* retain $0 */
8572 /* This realloc's G.global_argv */
8573 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8580 return EXIT_SUCCESS;
8582 /* Nothing known, so abort */
8584 bb_error_msg("set: %s: invalid option", arg);
8585 return EXIT_FAILURE;
8588 static int FAST_FUNC builtin_shift(char **argv)
8591 argv = skip_dash_dash(argv);
8595 if (n >= 0 && n < G.global_argc) {
8596 if (G.global_args_malloced) {
8599 free(G.global_argv[m++]);
8602 memmove(&G.global_argv[1], &G.global_argv[n+1],
8603 G.global_argc * sizeof(G.global_argv[0]));
8604 return EXIT_SUCCESS;
8606 return EXIT_FAILURE;
8609 static int FAST_FUNC builtin_source(char **argv)
8611 char *arg_path, *filename;
8614 #if ENABLE_HUSH_FUNCTIONS
8618 argv = skip_dash_dash(argv);
8621 /* bash says: "bash: .: filename argument required" */
8622 return 2; /* bash compat */
8625 if (!strchr(filename, '/')) {
8626 arg_path = find_in_path(filename);
8628 filename = arg_path;
8630 input = fopen_or_warn(filename, "r");
8633 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8634 return EXIT_FAILURE;
8636 close_on_exec_on(fileno(input));
8638 #if ENABLE_HUSH_FUNCTIONS
8639 sv_flg = G.flag_return_in_progress;
8640 /* "we are inside sourced file, ok to use return" */
8641 G.flag_return_in_progress = -1;
8643 save_and_replace_G_args(&sv, argv);
8645 parse_and_run_file(input);
8648 restore_G_args(&sv, argv);
8649 #if ENABLE_HUSH_FUNCTIONS
8650 G.flag_return_in_progress = sv_flg;
8653 return G.last_exitcode;
8656 static int FAST_FUNC builtin_umask(char **argv)
8662 argv = skip_dash_dash(argv);
8664 mode_t old_mask = mask;
8667 rc = bb_parse_mode(argv[0], &mask);
8672 * bash: umask: 'q': invalid symbolic mode operator
8673 * bash: umask: 999: octal number out of range
8675 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8680 printf("%04o\n", (unsigned) mask);
8681 /* fall through and restore mask which we set to 0 */
8685 return !rc; /* rc != 0 - success */
8688 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8689 static int FAST_FUNC builtin_unset(char **argv)
8694 /* "!": do not abort on errors */
8695 /* "+": stop at 1st non-option */
8696 opts = getopt32(argv, "!+vf");
8697 if (opts == (unsigned)-1)
8698 return EXIT_FAILURE;
8700 bb_error_msg("unset: -v and -f are exclusive");
8701 return EXIT_FAILURE;
8707 if (!(opts & 2)) { /* not -f */
8708 if (unset_local_var(*argv)) {
8709 /* unset <nonexistent_var> doesn't fail.
8710 * Error is when one tries to unset RO var.
8711 * Message was printed by unset_local_var. */
8715 #if ENABLE_HUSH_FUNCTIONS
8725 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
8726 static int FAST_FUNC builtin_wait(char **argv)
8728 int ret = EXIT_SUCCESS;
8731 argv = skip_dash_dash(argv);
8732 if (argv[0] == NULL) {
8733 /* Don't care about wait results */
8734 /* Note 1: must wait until there are no more children */
8735 /* Note 2: must be interruptible */
8737 * $ sleep 3 & sleep 6 & wait
8742 * $ sleep 3 & sleep 6 & wait
8746 * ^C <-- after ~4 sec from keyboard
8749 sigaddset(&G.blocked_set, SIGCHLD);
8750 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8753 if (errno == ECHILD)
8755 /* Wait for SIGCHLD or any other signal of interest */
8756 /* sigtimedwait with infinite timeout: */
8757 sig = sigwaitinfo(&G.blocked_set, NULL);
8759 sig = check_and_run_traps(sig);
8760 if (sig && sig != SIGCHLD) { /* see note 2 */
8766 sigdelset(&G.blocked_set, SIGCHLD);
8767 sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
8771 /* This is probably buggy wrt interruptible-ness */
8773 pid_t pid = bb_strtou(*argv, NULL, 10);
8775 /* mimic bash message */
8776 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
8777 return EXIT_FAILURE;
8779 if (waitpid(pid, &status, 0) == pid) {
8780 if (WIFSIGNALED(status))
8781 ret = 128 + WTERMSIG(status);
8782 else if (WIFEXITED(status))
8783 ret = WEXITSTATUS(status);
8787 bb_perror_msg("wait %s", *argv);
8796 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
8797 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
8800 def = bb_strtou(argv[1], NULL, 10);
8801 if (errno || def < def_min || argv[2]) {
8802 bb_error_msg("%s: bad arguments", argv[0]);
8810 #if ENABLE_HUSH_LOOPS
8811 static int FAST_FUNC builtin_break(char **argv)
8814 if (G.depth_of_loop == 0) {
8815 bb_error_msg("%s: only meaningful in a loop", argv[0]);
8816 return EXIT_SUCCESS; /* bash compat */
8818 G.flag_break_continue++; /* BC_BREAK = 1 */
8820 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
8821 if (depth == UINT_MAX)
8822 G.flag_break_continue = BC_BREAK;
8823 if (G.depth_of_loop < depth)
8824 G.depth_break_continue = G.depth_of_loop;
8826 return EXIT_SUCCESS;
8829 static int FAST_FUNC builtin_continue(char **argv)
8831 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
8832 return builtin_break(argv);
8836 #if ENABLE_HUSH_FUNCTIONS
8837 static int FAST_FUNC builtin_return(char **argv)
8841 if (G.flag_return_in_progress != -1) {
8842 bb_error_msg("%s: not in a function or sourced script", argv[0]);
8843 return EXIT_FAILURE; /* bash compat */
8846 G.flag_return_in_progress = 1;
8849 * out of range: wraps around at 256, does not error out
8850 * non-numeric param:
8851 * f() { false; return qwe; }; f; echo $?
8852 * bash: return: qwe: numeric argument required <== we do this
8853 * 255 <== we also do this
8855 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);