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> */
94 #include <sys/utsname.h> /* for setting $HOSTNAME */
96 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
98 #include "shell_common.h"
101 #if ENABLE_HUSH_RANDOM_SUPPORT
104 # define CLEAR_RANDOM_T(rnd) ((void)0)
107 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
111 //config: bool "hush"
114 //config: hush is a small shell (25k). It handles the normal flow control
115 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
116 //config: case/esac. Redirections, here documents, $((arithmetic))
117 //config: and functions are supported.
119 //config: It will compile and work on no-mmu systems.
121 //config: It does not handle select, aliases, tilde expansion,
122 //config: &>file and >&file redirection of stdout+stderr.
124 //config:config HUSH_BASH_COMPAT
125 //config: bool "bash-compatible extensions"
127 //config: depends on HUSH
129 //config: Enable bash-compatible extensions.
131 //config:config HUSH_BRACE_EXPANSION
132 //config: bool "Brace expansion"
134 //config: depends on HUSH_BASH_COMPAT
136 //config: Enable {abc,def} extension.
138 //config:config HUSH_HELP
139 //config: bool "help builtin"
141 //config: depends on HUSH
143 //config: Enable help builtin in hush. Code size + ~1 kbyte.
145 //config:config HUSH_INTERACTIVE
146 //config: bool "Interactive mode"
148 //config: depends on HUSH
150 //config: Enable interactive mode (prompt and command editing).
151 //config: Without this, hush simply reads and executes commands
152 //config: from stdin just like a shell script from a file.
153 //config: No prompt, no PS1/PS2 magic shell variables.
155 //config:config HUSH_SAVEHISTORY
156 //config: bool "Save command history to .hush_history"
158 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
160 //config: Enable history saving in hush.
162 //config:config HUSH_JOB
163 //config: bool "Job control"
165 //config: depends on HUSH_INTERACTIVE
167 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
168 //config: command (not entire shell), fg/bg builtins work. Without this option,
169 //config: "cmd &" still works by simply spawning a process and immediately
170 //config: prompting for next command (or executing next command in a script),
171 //config: but no separate process group is formed.
173 //config:config HUSH_TICK
174 //config: bool "Process substitution"
176 //config: depends on HUSH
178 //config: Enable process substitution `command` and $(command) in hush.
180 //config:config HUSH_IF
181 //config: bool "Support if/then/elif/else/fi"
183 //config: depends on HUSH
185 //config: Enable if/then/elif/else/fi in hush.
187 //config:config HUSH_LOOPS
188 //config: bool "Support for, while and until loops"
190 //config: depends on HUSH
192 //config: Enable for, while and until loops in hush.
194 //config:config HUSH_CASE
195 //config: bool "Support case ... esac statement"
197 //config: depends on HUSH
199 //config: Enable case ... esac statement in hush. +400 bytes.
201 //config:config HUSH_FUNCTIONS
202 //config: bool "Support funcname() { commands; } syntax"
204 //config: depends on HUSH
206 //config: Enable support for shell functions in hush. +800 bytes.
208 //config:config HUSH_LOCAL
209 //config: bool "Support local builtin"
211 //config: depends on HUSH_FUNCTIONS
213 //config: Enable support for local variables in functions.
215 //config:config HUSH_RANDOM_SUPPORT
216 //config: bool "Pseudorandom generator and $RANDOM variable"
218 //config: depends on HUSH
220 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
221 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
223 //config:config HUSH_EXPORT_N
224 //config: bool "Support 'export -n' option"
226 //config: depends on HUSH
228 //config: export -n unexports variables. It is a bash extension.
230 //config:config HUSH_MODE_X
231 //config: bool "Support 'hush -x' option and 'set -x' command"
233 //config: depends on HUSH
235 //config: This instructs hush to print commands before execution.
236 //config: Adds ~300 bytes.
239 //config: bool "msh (deprecated: aliased to hush)"
241 //config: select HUSH
243 //config: msh is deprecated and will be removed, please migrate to hush.
246 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
247 //applet:IF_MSH(APPLET(msh, BB_DIR_BIN, BB_SUID_DROP))
248 //applet:IF_FEATURE_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, sh))
249 //applet:IF_FEATURE_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, bash))
251 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
252 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
254 /* -i (interactive) and -s (read stdin) are also accepted,
255 * but currently do nothing, therefore aren't shown in help.
256 * NOMMU-specific options are not meant to be used by users,
257 * therefore we don't show them either.
259 //usage:#define hush_trivial_usage
260 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
261 //usage:#define hush_full_usage "\n\n"
262 //usage: "Unix shell interpreter"
264 //usage:#define msh_trivial_usage hush_trivial_usage
265 //usage:#define msh_full_usage hush_full_usage
267 //usage:#if ENABLE_FEATURE_SH_IS_HUSH
268 //usage:# define sh_trivial_usage hush_trivial_usage
269 //usage:# define sh_full_usage hush_full_usage
271 //usage:#if ENABLE_FEATURE_BASH_IS_HUSH
272 //usage:# define bash_trivial_usage hush_trivial_usage
273 //usage:# define bash_full_usage hush_full_usage
278 #define LEAK_HUNTING 0
279 #define BUILD_AS_NOMMU 0
280 /* Enable/disable sanity checks. Ok to enable in production,
281 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
282 * Keeping 1 for now even in released versions.
285 /* Slightly bigger (+200 bytes), but faster hush.
286 * So far it only enables a trick with counting SIGCHLDs and forks,
287 * which allows us to do fewer waitpid's.
288 * (we can detect a case where neither forks were done nor SIGCHLDs happened
289 * and therefore waitpid will return the same result as last time)
291 #define ENABLE_HUSH_FAST 0
292 /* TODO: implement simplified code for users which do not need ${var%...} ops
293 * So far ${var%...} ops are always enabled:
295 #define ENABLE_HUSH_DOLLAR_OPS 1
300 # undef USE_FOR_NOMMU
303 # define USE_FOR_NOMMU(...) __VA_ARGS__
304 # define USE_FOR_MMU(...)
307 #include "NUM_APPLETS.h"
309 /* STANDALONE does not make sense, and won't compile */
310 # undef CONFIG_FEATURE_SH_STANDALONE
311 # undef ENABLE_FEATURE_SH_STANDALONE
312 # undef IF_FEATURE_SH_STANDALONE
313 # undef IF_NOT_FEATURE_SH_STANDALONE
314 # define ENABLE_FEATURE_SH_STANDALONE 0
315 # define IF_FEATURE_SH_STANDALONE(...)
316 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
319 #if !ENABLE_HUSH_INTERACTIVE
320 # undef ENABLE_FEATURE_EDITING
321 # define ENABLE_FEATURE_EDITING 0
322 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
323 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
324 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
325 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
328 /* Do we support ANY keywords? */
329 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
330 # define HAS_KEYWORDS 1
331 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
332 # define IF_HAS_NO_KEYWORDS(...)
334 # define HAS_KEYWORDS 0
335 # define IF_HAS_KEYWORDS(...)
336 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
339 /* If you comment out one of these below, it will be #defined later
340 * to perform debug printfs to stderr: */
341 #define debug_printf(...) do {} while (0)
342 /* Finer-grained debug switches */
343 #define debug_printf_parse(...) do {} while (0)
344 #define debug_print_tree(a, b) do {} while (0)
345 #define debug_printf_exec(...) do {} while (0)
346 #define debug_printf_env(...) do {} while (0)
347 #define debug_printf_jobs(...) do {} while (0)
348 #define debug_printf_expand(...) do {} while (0)
349 #define debug_printf_varexp(...) do {} while (0)
350 #define debug_printf_glob(...) do {} while (0)
351 #define debug_printf_list(...) do {} while (0)
352 #define debug_printf_subst(...) do {} while (0)
353 #define debug_printf_clean(...) do {} while (0)
355 #define ERR_PTR ((void*)(long)1)
357 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
359 #define _SPECIAL_VARS_STR "_*@$!?#"
360 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
361 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
362 #if ENABLE_HUSH_BASH_COMPAT
363 /* Support / and // replace ops */
364 /* Note that // is stored as \ in "encoded" string representation */
365 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
366 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
367 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
369 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
370 # define VAR_SUBST_OPS "%#:-=+?"
371 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
374 #define SPECIAL_VAR_SYMBOL 3
378 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
380 /* This supports saving pointers malloced in vfork child,
381 * to be freed in the parent.
384 typedef struct nommu_save_t {
386 struct variable *old_vars;
388 char **argv_from_re_execing;
401 #if ENABLE_HUSH_LOOPS
408 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
413 /* three pseudo-keywords support contrived "case" syntax: */
414 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
415 RES_MATCH , /* "word)" */
416 RES_CASE_BODY, /* "this command is inside CASE" */
423 typedef struct o_string {
425 int length; /* position where data is appended */
428 /* At least some part of the string was inside '' or "",
429 * possibly empty one: word"", wo''rd etc. */
430 smallint has_quoted_part;
431 smallint has_empty_slot;
432 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
435 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
437 /* Protect newly added chars against globbing
438 * by prepending \ to *, ?, [, \ */
439 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
442 MAYBE_ASSIGNMENT = 0,
443 DEFINITELY_ASSIGNMENT = 1,
445 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
448 /* Used for initialization: o_string foo = NULL_O_STRING; */
449 #define NULL_O_STRING { NULL }
451 #ifndef debug_printf_parse
452 static const char *const assignment_flag[] = {
454 "DEFINITELY_ASSIGNMENT",
460 typedef struct in_str {
462 /* eof_flag=1: last char in ->p is really an EOF */
463 char eof_flag; /* meaningless if ->p == NULL */
465 #if ENABLE_HUSH_INTERACTIVE
466 smallint promptmode; /* 0: PS1, 1: PS2 */
470 int (*get) (struct in_str *) FAST_FUNC;
471 int (*peek) (struct in_str *) FAST_FUNC;
473 #define i_getch(input) ((input)->get(input))
474 #define i_peek(input) ((input)->peek(input))
476 /* The descrip member of this structure is only used to make
477 * debugging output pretty */
478 static const struct {
480 signed char default_fd;
483 { O_RDONLY, 0, "<" },
484 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
485 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
486 { O_CREAT|O_RDWR, 1, "<>" },
487 { O_RDONLY, 0, "<<" },
488 /* Should not be needed. Bogus default_fd helps in debugging */
489 /* { O_RDONLY, 77, "<<" }, */
492 struct redir_struct {
493 struct redir_struct *next;
494 char *rd_filename; /* filename */
495 int rd_fd; /* fd to redirect */
496 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
498 smallint rd_type; /* (enum redir_type) */
499 /* note: for heredocs, rd_filename contains heredoc delimiter,
500 * and subsequently heredoc itself; and rd_dup is a bitmask:
501 * bit 0: do we need to trim leading tabs?
502 * bit 1: is heredoc quoted (<<'delim' syntax) ?
505 typedef enum redir_type {
507 REDIRECT_OVERWRITE = 1,
510 REDIRECT_HEREDOC = 4,
511 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
514 REDIRFD_SYNTAX_ERR = -2,
515 REDIRFD_TO_FILE = -1,
516 /* otherwise, rd_fd is redirected to rd_dup */
518 HEREDOC_SKIPTABS = 1,
524 pid_t pid; /* 0 if exited */
525 int assignment_cnt; /* how many argv[i] are assignments? */
526 smallint cmd_type; /* CMD_xxx */
528 #define CMD_SUBSHELL 1
529 #if ENABLE_HUSH_BASH_COMPAT
530 /* used for "[[ EXPR ]]" */
531 # define CMD_SINGLEWORD_NOGLOB 2
533 #if ENABLE_HUSH_FUNCTIONS
534 # define CMD_FUNCDEF 3
537 smalluint cmd_exitcode;
538 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
541 char *group_as_string;
543 #if ENABLE_HUSH_FUNCTIONS
544 struct function *child_func;
545 /* This field is used to prevent a bug here:
546 * while...do f1() {a;}; f1; f1() {b;}; f1; done
547 * When we execute "f1() {a;}" cmd, we create new function and clear
548 * cmd->group, cmd->group_as_string, cmd->argv[0].
549 * When we execute "f1() {b;}", we notice that f1 exists,
550 * and that its "parent cmd" struct is still "alive",
551 * we put those fields back into cmd->xxx
552 * (struct function has ->parent_cmd ptr to facilitate that).
553 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
554 * Without this trick, loop would execute a;b;b;b;...
555 * instead of correct sequence a;b;a;b;...
556 * When command is freed, it severs the link
557 * (sets ->child_func->parent_cmd to NULL).
560 char **argv; /* command name and arguments */
561 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
562 * and on execution these are substituted with their values.
563 * Substitution can make _several_ words out of one argv[n]!
564 * Example: argv[0]=='.^C*^C.' here: echo .$*.
565 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
567 struct redir_struct *redirects; /* I/O redirections */
569 /* Is there anything in this command at all? */
570 #define IS_NULL_CMD(cmd) \
571 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
575 int num_cmds; /* total number of commands in pipe */
576 int alive_cmds; /* number of commands running (not exited) */
577 int stopped_cmds; /* number of commands alive, but stopped */
579 int jobid; /* job number */
580 pid_t pgrp; /* process group ID for the job */
581 char *cmdtext; /* name of job */
583 struct command *cmds; /* array of commands in pipe */
584 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
585 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
586 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
588 typedef enum pipe_style {
594 /* Is there anything in this pipe at all? */
595 #define IS_NULL_PIPE(pi) \
596 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
598 /* This holds pointers to the various results of parsing */
599 struct parse_context {
600 /* linked list of pipes */
601 struct pipe *list_head;
602 /* last pipe (being constructed right now) */
604 /* last command in pipe (being constructed right now) */
605 struct command *command;
606 /* last redirect in command->redirects list */
607 struct redir_struct *pending_redirect;
613 smallint ctx_inverted; /* "! cmd | cmd" */
615 smallint ctx_dsemicolon; /* ";;" seen */
617 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
619 /* group we are enclosed in:
620 * example: "if pipe1; pipe2; then pipe3; fi"
621 * when we see "if" or "then", we malloc and copy current context,
622 * and make ->stack point to it. then we parse pipeN.
623 * when closing "then" / fi" / whatever is found,
624 * we move list_head into ->stack->command->group,
625 * copy ->stack into current context, and delete ->stack.
626 * (parsing of { list } and ( list ) doesn't use this method)
628 struct parse_context *stack;
632 /* On program start, environ points to initial environment.
633 * putenv adds new pointers into it, unsetenv removes them.
634 * Neither of these (de)allocates the strings.
635 * setenv allocates new strings in malloc space and does putenv,
636 * and thus setenv is unusable (leaky) for shell's purposes */
637 #define setenv(...) setenv_is_leaky_dont_use()
639 struct variable *next;
640 char *varstr; /* points to "name=" portion */
641 #if ENABLE_HUSH_LOCAL
642 unsigned func_nest_level;
644 int max_len; /* if > 0, name is part of initial env; else name is malloced */
645 smallint flg_export; /* putenv should be done on this var */
646 smallint flg_read_only;
654 #if ENABLE_HUSH_FUNCTIONS
656 struct function *next;
658 struct command *parent_cmd;
661 char *body_as_string;
667 /* set -/+o OPT support. (TODO: make it optional)
668 * bash supports the following opts:
679 * interactive-comments on
697 static const char o_opt_strings[] ALIGN1 =
700 #if ENABLE_HUSH_MODE_X
707 #if ENABLE_HUSH_MODE_X
714 /* "Globals" within this file */
715 /* Sorted roughly by size (smaller offsets == smaller code) */
717 /* interactive_fd != 0 means we are an interactive shell.
718 * If we are, then saved_tty_pgrp can also be != 0, meaning
719 * that controlling tty is available. With saved_tty_pgrp == 0,
720 * job control still works, but terminal signals
721 * (^C, ^Z, ^Y, ^\) won't work at all, and background
722 * process groups can only be created with "cmd &".
723 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
724 * to give tty to the foreground process group,
725 * and will take it back when the group is stopped (^Z)
728 #if ENABLE_HUSH_INTERACTIVE
729 /* 'interactive_fd' is a fd# open to ctty, if we have one
730 * _AND_ if we decided to act interactively */
734 # define G_interactive_fd (G.interactive_fd)
736 # define G_interactive_fd 0
738 #if ENABLE_FEATURE_EDITING
739 line_input_t *line_input_state;
744 #if ENABLE_HUSH_RANDOM_SUPPORT
750 pid_t saved_tty_pgrp;
751 struct pipe *job_list;
752 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
754 # define G_saved_tty_pgrp 0
756 char o_opt[NUM_OPT_O];
757 #if ENABLE_HUSH_MODE_X
758 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
762 smallint flag_SIGINT;
763 #if ENABLE_HUSH_LOOPS
764 smallint flag_break_continue;
766 #if ENABLE_HUSH_FUNCTIONS
767 /* 0: outside of a function (or sourced file)
768 * -1: inside of a function, ok to use return builtin
769 * 1: return is invoked, skip all till end of func
771 smallint flag_return_in_progress;
773 smallint exiting; /* used to prevent EXIT trap recursion */
774 /* These four support $?, $#, and $1 */
775 smalluint last_exitcode;
776 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
777 smalluint global_args_malloced;
778 /* how many non-NULL argv's we have. NB: $# + 1 */
782 char *argv0_for_re_execing;
784 #if ENABLE_HUSH_LOOPS
785 unsigned depth_break_continue;
786 unsigned depth_of_loop;
790 struct variable *top_var;
791 char **expanded_assignments;
792 #if ENABLE_HUSH_FUNCTIONS
793 struct function *top_func;
794 # if ENABLE_HUSH_LOCAL
795 struct variable **shadowed_vars_pp;
796 unsigned func_nest_level;
799 /* Signal and trap handling */
801 unsigned count_SIGCHLD;
802 unsigned handled_SIGCHLD;
803 smallint we_have_children;
805 /* Which signals have non-DFL handler (even with no traps set)?
806 * Set at the start to:
807 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
808 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
809 * The rest is cleared right before execv syscalls.
810 * Other than these two times, never modified.
812 unsigned special_sig_mask;
814 unsigned fatal_sig_mask;
815 # define G_fatal_sig_mask G.fatal_sig_mask
817 # define G_fatal_sig_mask 0
819 char **traps; /* char *traps[NSIG] */
820 sigset_t pending_set;
822 unsigned long memleak_value;
826 char user_input_buf[ENABLE_FEATURE_EDITING ? CONFIG_FEATURE_EDITING_MAX_LEN : 2];
828 #define G (*ptr_to_globals)
829 /* Not #defining name to G.name - this quickly gets unwieldy
830 * (too many defines). Also, I actually prefer to see when a variable
831 * is global, thus "G." prefix is a useful hint */
832 #define INIT_G() do { \
833 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
834 /* memset(&G.sa, 0, sizeof(G.sa)); */ \
835 sigfillset(&G.sa.sa_mask); \
836 G.sa.sa_flags = SA_RESTART; \
840 /* Function prototypes for builtins */
841 static int builtin_cd(char **argv) FAST_FUNC;
842 static int builtin_echo(char **argv) FAST_FUNC;
843 static int builtin_eval(char **argv) FAST_FUNC;
844 static int builtin_exec(char **argv) FAST_FUNC;
845 static int builtin_exit(char **argv) FAST_FUNC;
846 static int builtin_export(char **argv) FAST_FUNC;
848 static int builtin_fg_bg(char **argv) FAST_FUNC;
849 static int builtin_jobs(char **argv) FAST_FUNC;
852 static int builtin_help(char **argv) FAST_FUNC;
854 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
855 static int builtin_history(char **argv) FAST_FUNC;
857 #if ENABLE_HUSH_LOCAL
858 static int builtin_local(char **argv) FAST_FUNC;
861 static int builtin_memleak(char **argv) FAST_FUNC;
864 static int builtin_printf(char **argv) FAST_FUNC;
866 static int builtin_pwd(char **argv) FAST_FUNC;
867 static int builtin_read(char **argv) FAST_FUNC;
868 static int builtin_set(char **argv) FAST_FUNC;
869 static int builtin_shift(char **argv) FAST_FUNC;
870 static int builtin_source(char **argv) FAST_FUNC;
871 static int builtin_test(char **argv) FAST_FUNC;
872 static int builtin_trap(char **argv) FAST_FUNC;
873 static int builtin_type(char **argv) FAST_FUNC;
874 static int builtin_true(char **argv) FAST_FUNC;
875 static int builtin_umask(char **argv) FAST_FUNC;
876 static int builtin_unset(char **argv) FAST_FUNC;
877 static int builtin_wait(char **argv) FAST_FUNC;
878 #if ENABLE_HUSH_LOOPS
879 static int builtin_break(char **argv) FAST_FUNC;
880 static int builtin_continue(char **argv) FAST_FUNC;
882 #if ENABLE_HUSH_FUNCTIONS
883 static int builtin_return(char **argv) FAST_FUNC;
886 /* Table of built-in functions. They can be forked or not, depending on
887 * context: within pipes, they fork. As simple commands, they do not.
888 * When used in non-forking context, they can change global variables
889 * in the parent shell process. If forked, of course they cannot.
890 * For example, 'unset foo | whatever' will parse and run, but foo will
891 * still be set at the end. */
892 struct built_in_command {
894 int (*b_function)(char **argv) FAST_FUNC;
897 # define BLTIN(cmd, func, help) { cmd, func, help }
899 # define BLTIN(cmd, func, help) { cmd, func }
903 static const struct built_in_command bltins1[] = {
904 BLTIN("." , builtin_source , "Run commands in a file"),
905 BLTIN(":" , builtin_true , NULL),
907 BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
909 #if ENABLE_HUSH_LOOPS
910 BLTIN("break" , builtin_break , "Exit from a loop"),
912 BLTIN("cd" , builtin_cd , "Change directory"),
913 #if ENABLE_HUSH_LOOPS
914 BLTIN("continue" , builtin_continue, "Start new loop iteration"),
916 BLTIN("eval" , builtin_eval , "Construct and run shell command"),
917 BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
918 BLTIN("exit" , builtin_exit , "Exit"),
919 BLTIN("export" , builtin_export , "Set environment variables"),
921 BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
924 BLTIN("help" , builtin_help , NULL),
926 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
927 BLTIN("history" , builtin_history , "Show command history"),
930 BLTIN("jobs" , builtin_jobs , "List jobs"),
932 #if ENABLE_HUSH_LOCAL
933 BLTIN("local" , builtin_local , "Set local variables"),
936 BLTIN("memleak" , builtin_memleak , NULL),
938 BLTIN("read" , builtin_read , "Input into variable"),
939 #if ENABLE_HUSH_FUNCTIONS
940 BLTIN("return" , builtin_return , "Return from a function"),
942 BLTIN("set" , builtin_set , "Set/unset positional parameters"),
943 BLTIN("shift" , builtin_shift , "Shift positional parameters"),
944 #if ENABLE_HUSH_BASH_COMPAT
945 BLTIN("source" , builtin_source , "Run commands in a file"),
947 BLTIN("trap" , builtin_trap , "Trap signals"),
948 BLTIN("true" , builtin_true , NULL),
949 BLTIN("type" , builtin_type , "Show command type"),
950 BLTIN("ulimit" , shell_builtin_ulimit , "Control resource limits"),
951 BLTIN("umask" , builtin_umask , "Set file creation mask"),
952 BLTIN("unset" , builtin_unset , "Unset variables"),
953 BLTIN("wait" , builtin_wait , "Wait for process"),
955 /* For now, echo and test are unconditionally enabled.
956 * Maybe make it configurable? */
957 static const struct built_in_command bltins2[] = {
958 BLTIN("[" , builtin_test , NULL),
959 BLTIN("echo" , builtin_echo , NULL),
961 BLTIN("printf" , builtin_printf , NULL),
963 BLTIN("pwd" , builtin_pwd , NULL),
964 BLTIN("test" , builtin_test , NULL),
971 /* prevent disasters with G.debug_indent < 0 */
972 # define indent() fdprintf(2, "%*s", (G.debug_indent * 2) & 0xff, "")
973 # define debug_enter() (G.debug_indent++)
974 # define debug_leave() (G.debug_indent--)
976 # define indent() ((void)0)
977 # define debug_enter() ((void)0)
978 # define debug_leave() ((void)0)
982 # define debug_printf(...) (indent(), fdprintf(2, __VA_ARGS__))
985 #ifndef debug_printf_parse
986 # define debug_printf_parse(...) (indent(), fdprintf(2, __VA_ARGS__))
989 #ifndef debug_printf_exec
990 #define debug_printf_exec(...) (indent(), fdprintf(2, __VA_ARGS__))
993 #ifndef debug_printf_env
994 # define debug_printf_env(...) (indent(), fdprintf(2, __VA_ARGS__))
997 #ifndef debug_printf_jobs
998 # define debug_printf_jobs(...) (indent(), fdprintf(2, __VA_ARGS__))
999 # define DEBUG_JOBS 1
1001 # define DEBUG_JOBS 0
1004 #ifndef debug_printf_expand
1005 # define debug_printf_expand(...) (indent(), fdprintf(2, __VA_ARGS__))
1006 # define DEBUG_EXPAND 1
1008 # define DEBUG_EXPAND 0
1011 #ifndef debug_printf_varexp
1012 # define debug_printf_varexp(...) (indent(), fdprintf(2, __VA_ARGS__))
1015 #ifndef debug_printf_glob
1016 # define debug_printf_glob(...) (indent(), fdprintf(2, __VA_ARGS__))
1017 # define DEBUG_GLOB 1
1019 # define DEBUG_GLOB 0
1022 #ifndef debug_printf_list
1023 # define debug_printf_list(...) (indent(), fdprintf(2, __VA_ARGS__))
1026 #ifndef debug_printf_subst
1027 # define debug_printf_subst(...) (indent(), fdprintf(2, __VA_ARGS__))
1030 #ifndef debug_printf_clean
1031 # define debug_printf_clean(...) (indent(), fdprintf(2, __VA_ARGS__))
1032 # define DEBUG_CLEAN 1
1034 # define DEBUG_CLEAN 0
1038 static void debug_print_strings(const char *prefix, char **vv)
1041 fdprintf(2, "%s:\n", prefix);
1043 fdprintf(2, " '%s'\n", *vv++);
1046 # define debug_print_strings(prefix, vv) ((void)0)
1050 /* Leak hunting. Use hush_leaktool.sh for post-processing.
1053 static void *xxmalloc(int lineno, size_t size)
1055 void *ptr = xmalloc((size + 0xff) & ~0xff);
1056 fdprintf(2, "line %d: malloc %p\n", lineno, ptr);
1059 static void *xxrealloc(int lineno, void *ptr, size_t size)
1061 ptr = xrealloc(ptr, (size + 0xff) & ~0xff);
1062 fdprintf(2, "line %d: realloc %p\n", lineno, ptr);
1065 static char *xxstrdup(int lineno, const char *str)
1067 char *ptr = xstrdup(str);
1068 fdprintf(2, "line %d: strdup %p\n", lineno, ptr);
1071 static void xxfree(void *ptr)
1073 fdprintf(2, "free %p\n", ptr);
1076 # define xmalloc(s) xxmalloc(__LINE__, s)
1077 # define xrealloc(p, s) xxrealloc(__LINE__, p, s)
1078 # define xstrdup(s) xxstrdup(__LINE__, s)
1079 # define free(p) xxfree(p)
1083 /* Syntax and runtime errors. They always abort scripts.
1084 * In interactive use they usually discard unparsed and/or unexecuted commands
1085 * and return to the prompt.
1086 * HUSH_DEBUG >= 2 prints line number in this file where it was detected.
1089 # define die_if_script(lineno, ...) die_if_script(__VA_ARGS__)
1090 # define syntax_error(lineno, msg) syntax_error(msg)
1091 # define syntax_error_at(lineno, msg) syntax_error_at(msg)
1092 # define syntax_error_unterm_ch(lineno, ch) syntax_error_unterm_ch(ch)
1093 # define syntax_error_unterm_str(lineno, s) syntax_error_unterm_str(s)
1094 # define syntax_error_unexpected_ch(lineno, ch) syntax_error_unexpected_ch(ch)
1097 static void die_if_script(unsigned lineno, const char *fmt, ...)
1102 bb_error_msg("hush.c:%u", lineno);
1105 bb_verror_msg(fmt, p, NULL);
1107 if (!G_interactive_fd)
1111 static void syntax_error(unsigned lineno UNUSED_PARAM, const char *msg)
1114 bb_error_msg("syntax error: %s", msg);
1116 bb_error_msg("syntax error");
1119 static void syntax_error_at(unsigned lineno UNUSED_PARAM, const char *msg)
1121 bb_error_msg("syntax error at '%s'", msg);
1124 static void syntax_error_unterm_str(unsigned lineno UNUSED_PARAM, const char *s)
1126 bb_error_msg("syntax error: unterminated %s", s);
1129 static void syntax_error_unterm_ch(unsigned lineno, char ch)
1131 char msg[2] = { ch, '\0' };
1132 syntax_error_unterm_str(lineno, msg);
1135 static void syntax_error_unexpected_ch(unsigned lineno UNUSED_PARAM, int ch)
1140 bb_error_msg("syntax error: unexpected %s", ch == EOF ? "EOF" : msg);
1144 # undef die_if_script
1145 # undef syntax_error
1146 # undef syntax_error_at
1147 # undef syntax_error_unterm_ch
1148 # undef syntax_error_unterm_str
1149 # undef syntax_error_unexpected_ch
1151 # define die_if_script(...) die_if_script(__LINE__, __VA_ARGS__)
1152 # define syntax_error(msg) syntax_error(__LINE__, msg)
1153 # define syntax_error_at(msg) syntax_error_at(__LINE__, msg)
1154 # define syntax_error_unterm_ch(ch) syntax_error_unterm_ch(__LINE__, ch)
1155 # define syntax_error_unterm_str(s) syntax_error_unterm_str(__LINE__, s)
1156 # define syntax_error_unexpected_ch(ch) syntax_error_unexpected_ch(__LINE__, ch)
1160 #if ENABLE_HUSH_INTERACTIVE
1161 static void cmdedit_update_prompt(void);
1163 # define cmdedit_update_prompt() ((void)0)
1167 /* Utility functions
1169 /* Replace each \x with x in place, return ptr past NUL. */
1170 static char *unbackslash(char *src)
1172 char *dst = src = strchrnul(src, '\\');
1176 if ((*dst++ = *src++) == '\0')
1182 static char **add_strings_to_strings(char **strings, char **add, int need_to_dup)
1203 v = xrealloc(strings, (count1 + count2 + 1) * sizeof(char*));
1204 v[count1 + count2] = NULL;
1207 v[count1 + i] = (need_to_dup ? xstrdup(add[i]) : add[i]);
1211 static char **xx_add_strings_to_strings(int lineno, char **strings, char **add, int need_to_dup)
1213 char **ptr = add_strings_to_strings(strings, add, need_to_dup);
1214 fdprintf(2, "line %d: add_strings_to_strings %p\n", lineno, ptr);
1217 #define add_strings_to_strings(strings, add, need_to_dup) \
1218 xx_add_strings_to_strings(__LINE__, strings, add, need_to_dup)
1221 /* Note: takes ownership of "add" ptr (it is not strdup'ed) */
1222 static char **add_string_to_strings(char **strings, char *add)
1227 return add_strings_to_strings(strings, v, /*dup:*/ 0);
1230 static char **xx_add_string_to_strings(int lineno, char **strings, char *add)
1232 char **ptr = add_string_to_strings(strings, add);
1233 fdprintf(2, "line %d: add_string_to_strings %p\n", lineno, ptr);
1236 #define add_string_to_strings(strings, add) \
1237 xx_add_string_to_strings(__LINE__, strings, add)
1240 static void free_strings(char **strings)
1255 /* Helpers for setting new $n and restoring them back
1257 typedef struct save_arg_t {
1261 smallint sv_g_malloced;
1264 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1268 sv->sv_argv0 = argv[0];
1269 sv->sv_g_argv = G.global_argv;
1270 sv->sv_g_argc = G.global_argc;
1271 sv->sv_g_malloced = G.global_args_malloced;
1273 argv[0] = G.global_argv[0]; /* retain $0 */
1274 G.global_argv = argv;
1275 G.global_args_malloced = 0;
1283 static void restore_G_args(save_arg_t *sv, char **argv)
1287 if (G.global_args_malloced) {
1288 /* someone ran "set -- arg1 arg2 ...", undo */
1290 while (*++pp) /* note: does not free $0 */
1292 free(G.global_argv);
1294 argv[0] = sv->sv_argv0;
1295 G.global_argv = sv->sv_g_argv;
1296 G.global_argc = sv->sv_g_argc;
1297 G.global_args_malloced = sv->sv_g_malloced;
1301 /* Basic theory of signal handling in shell
1302 * ========================================
1303 * This does not describe what hush does, rather, it is current understanding
1304 * what it _should_ do. If it doesn't, it's a bug.
1305 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1307 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1308 * is finished or backgrounded. It is the same in interactive and
1309 * non-interactive shells, and is the same regardless of whether
1310 * a user trap handler is installed or a shell special one is in effect.
1311 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1312 * backgrounds (i.e. stops) or kills all members of currently running
1315 * Wait builtin is interruptible by signals for which user trap is set
1316 * or by SIGINT in interactive shell.
1318 * Trap handlers will execute even within trap handlers. (right?)
1320 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1321 * except for handlers set to '' (empty string).
1323 * If job control is off, backgrounded commands ("cmd &")
1324 * have SIGINT, SIGQUIT set to SIG_IGN.
1326 * Commands which are run in command substitution ("`cmd`")
1327 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1329 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1330 * by the shell from its parent.
1332 * Signals which differ from SIG_DFL action
1333 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1336 * SIGTERM (interactive): ignore
1337 * SIGHUP (interactive):
1338 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1339 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1340 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1341 * that all pipe members are stopped. Try this in bash:
1342 * while :; do :; done - ^Z does not background it
1343 * (while :; do :; done) - ^Z backgrounds it
1344 * SIGINT (interactive): wait for last pipe, ignore the rest
1345 * of the command line, show prompt. NB: ^C does not send SIGINT
1346 * to interactive shell while shell is waiting for a pipe,
1347 * since shell is bg'ed (is not in foreground process group).
1348 * Example 1: this waits 5 sec, but does not execute ls:
1349 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1350 * Example 2: this does not wait and does not execute ls:
1351 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1352 * Example 3: this does not wait 5 sec, but executes ls:
1353 * "sleep 5; ls -l" + press ^C
1354 * Example 4: this does not wait and does not execute ls:
1355 * "sleep 5 & wait; ls -l" + press ^C
1357 * (What happens to signals which are IGN on shell start?)
1358 * (What happens with signal mask on shell start?)
1360 * Old implementation
1361 * ==================
1362 * We use in-kernel pending signal mask to determine which signals were sent.
1363 * We block all signals which we don't want to take action immediately,
1364 * i.e. we block all signals which need to have special handling as described
1365 * above, and all signals which have traps set.
1366 * After each pipe execution, we extract any pending signals via sigtimedwait()
1369 * unsigned special_sig_mask: a mask of such "special" signals
1370 * sigset_t blocked_set: current blocked signal set
1373 * clear bit in blocked_set unless it is also in special_sig_mask
1374 * "trap 'cmd' SIGxxx":
1375 * set bit in blocked_set (even if 'cmd' is '')
1376 * after [v]fork, if we plan to be a shell:
1377 * unblock signals with special interactive handling
1378 * (child shell is not interactive),
1379 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1380 * after [v]fork, if we plan to exec:
1381 * POSIX says fork clears pending signal mask in child - no need to clear it.
1382 * Restore blocked signal set to one inherited by shell just prior to exec.
1384 * Note: as a result, we do not use signal handlers much. The only uses
1385 * are to count SIGCHLDs
1386 * and to restore tty pgrp on signal-induced exit.
1389 * Standard says "When a subshell is entered, traps that are not being ignored
1390 * are set to the default actions". bash interprets it so that traps which
1391 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1393 * Problem: the above approach makes it unwieldy to catch signals while
1394 * we are in read builtin, or while we read commands from stdin:
1395 * masked signals are not visible!
1397 * New implementation
1398 * ==================
1399 * We record each signal we are interested in by installing signal handler
1400 * for them - a bit like emulating kernel pending signal mask in userspace.
1401 * We are interested in: signals which need to have special handling
1402 * as described above, and all signals which have traps set.
1403 * Signals are recorded in pending_set.
1404 * After each pipe execution, we extract any pending signals
1407 * unsigned special_sig_mask: a mask of shell-special signals.
1408 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1409 * char *traps[sig] if trap for sig is set (even if it's '').
1410 * sigset_t pending_set: set of sigs we received.
1413 * if sig is in special_sig_mask, set handler back to:
1414 * record_pending_signo, or to IGN if it's a tty stop signal
1415 * if sig is in fatal_sig_mask, set handler back to sigexit.
1416 * else: set handler back to SIG_DFL
1417 * "trap 'cmd' SIGxxx":
1418 * set handler to record_pending_signo.
1420 * set handler to SIG_IGN.
1421 * after [v]fork, if we plan to be a shell:
1422 * set signals with special interactive handling to SIG_DFL
1423 * (because child shell is not interactive),
1424 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1425 * after [v]fork, if we plan to exec:
1426 * POSIX says fork clears pending signal mask in child - no need to clear it.
1428 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1429 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1432 * Standard says "When a subshell is entered, traps that are not being ignored
1433 * are set to the default actions". bash interprets it so that traps which
1434 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1437 SPECIAL_INTERACTIVE_SIGS = 0
1442 SPECIAL_JOBSTOP_SIGS = 0
1451 static void record_pending_signo(int sig)
1453 sigaddset(&G.pending_set, sig);
1454 #if ENABLE_HUSH_FAST
1455 if (sig == SIGCHLD) {
1457 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1462 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1464 struct sigaction old_sa;
1466 /* We could use signal() to install handlers... almost:
1467 * except that we need to mask ALL signals while handlers run.
1468 * I saw signal nesting in strace, race window isn't small.
1469 * SA_RESTART is also needed, but in Linux, signal()
1470 * sets SA_RESTART too.
1472 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1473 /* sigfillset(&G.sa.sa_mask); - already done */
1474 /* G.sa.sa_flags = SA_RESTART; - already done */
1475 G.sa.sa_handler = handler;
1476 sigaction(sig, &G.sa, &old_sa);
1477 return old_sa.sa_handler;
1482 static void xfunc_has_died(void);
1483 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1484 # define disable_restore_tty_pgrp_on_exit() (die_func = NULL)
1485 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1486 # define enable_restore_tty_pgrp_on_exit() (die_func = xfunc_has_died)
1488 /* Restores tty foreground process group, and exits.
1489 * May be called as signal handler for fatal signal
1490 * (will resend signal to itself, producing correct exit state)
1491 * or called directly with -EXITCODE.
1492 * We also call it if xfunc is exiting. */
1493 static void sigexit(int sig) NORETURN;
1494 static void sigexit(int sig)
1496 /* Careful: we can end up here after [v]fork. Do not restore
1497 * tty pgrp then, only top-level shell process does that */
1498 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1499 /* Disable all signals: job control, SIGPIPE, etc.
1500 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1502 sigprocmask_allsigs(SIG_BLOCK);
1503 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1506 /* Not a signal, just exit */
1510 kill_myself_with_sig(sig); /* does not return */
1514 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1515 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1519 static sighandler_t pick_sighandler(unsigned sig)
1521 sighandler_t handler = SIG_DFL;
1522 if (sig < sizeof(unsigned)*8) {
1523 unsigned sigmask = (1 << sig);
1527 if (G_fatal_sig_mask & sigmask)
1531 /* sig has special handling? */
1532 if (G.special_sig_mask & sigmask) {
1533 handler = record_pending_signo;
1534 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1535 * in order to ignore them: they will be raised
1536 * in an endless loop when we try to do some
1537 * terminal ioctls! We do have to _ignore_ these.
1539 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1546 /* Restores tty foreground process group, and exits. */
1547 static void hush_exit(int exitcode) NORETURN;
1548 static void hush_exit(int exitcode)
1550 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1551 save_history(G.line_input_state);
1555 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1557 /* argv[0] is unused */
1558 argv[1] = G.traps[0];
1560 G.exiting = 1; /* prevent EXIT trap recursion */
1561 /* Note: G.traps[0] is not cleared!
1562 * "trap" will still show it, if executed
1567 #if ENABLE_FEATURE_CLEAN_UP
1569 struct variable *cur_var;
1570 if (G.cwd != bb_msg_unknown)
1572 cur_var = G.top_var;
1574 struct variable *tmp = cur_var;
1575 if (!cur_var->max_len)
1576 free(cur_var->varstr);
1577 cur_var = cur_var->next;
1585 sigexit(- (exitcode & 0xff));
1591 static void xfunc_has_died(void) NORETURN;
1592 static void xfunc_has_died(void)
1594 /* xfunc has failed! die die die */
1595 /* no EXIT traps, this is an escape hatch! */
1597 hush_exit(xfunc_error_retval);
1601 //TODO: return a mask of ALL handled sigs?
1602 static int check_and_run_traps(void)
1609 if (sigisemptyset(&G.pending_set))
1614 if (sigismember(&G.pending_set, sig)) {
1615 sigdelset(&G.pending_set, sig);
1618 } while (sig < NSIG);
1621 if (G.traps && G.traps[sig]) {
1622 if (G.traps[sig][0]) {
1623 /* We have user-defined handler */
1624 smalluint save_rcode;
1626 /* argv[0] is unused */
1627 argv[1] = G.traps[sig];
1629 save_rcode = G.last_exitcode;
1631 G.last_exitcode = save_rcode;
1633 } /* else: "" trap, ignoring signal */
1636 /* not a trap: special action */
1639 /* Builtin was ^C'ed, make it look prettier: */
1647 /* bash is observed to signal whole process groups,
1648 * not individual processes */
1649 for (job = G.job_list; job; job = job->next) {
1652 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1653 if (kill(- job->pgrp, SIGHUP) == 0)
1654 kill(- job->pgrp, SIGCONT);
1659 #if ENABLE_HUSH_FAST
1662 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1664 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1665 * This simplifies wait builtin a bit.
1669 default: /* ignored: */
1670 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1672 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1673 * Example: wait is not interrupted by TERM
1674 * in interactive shell, because TERM is ignored.
1683 static const char *get_cwd(int force)
1685 if (force || G.cwd == NULL) {
1686 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1687 * we must not try to free(bb_msg_unknown) */
1688 if (G.cwd == bb_msg_unknown)
1690 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1692 G.cwd = bb_msg_unknown;
1699 * Shell and environment variable support
1701 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1703 struct variable **pp;
1704 struct variable *cur;
1707 while ((cur = *pp) != NULL) {
1708 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1715 static const char* FAST_FUNC get_local_var_value(const char *name)
1717 struct variable **vpp;
1718 unsigned len = strlen(name);
1720 if (G.expanded_assignments) {
1721 char **cpp = G.expanded_assignments;
1724 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1725 return cp + len + 1;
1730 vpp = get_ptr_to_local_var(name, len);
1732 return (*vpp)->varstr + len + 1;
1734 if (strcmp(name, "PPID") == 0)
1735 return utoa(G.root_ppid);
1736 // bash compat: UID? EUID?
1737 #if ENABLE_HUSH_RANDOM_SUPPORT
1738 if (strcmp(name, "RANDOM") == 0)
1739 return utoa(next_random(&G.random_gen));
1744 /* str holds "NAME=VAL" and is expected to be malloced.
1745 * We take ownership of it.
1747 * 0: do not change export flag
1748 * (if creating new variable, flag will be 0)
1749 * 1: set export flag and putenv the variable
1750 * -1: clear export flag and unsetenv the variable
1751 * flg_read_only is set only when we handle -R var=val
1753 #if !BB_MMU && ENABLE_HUSH_LOCAL
1754 /* all params are used */
1755 #elif BB_MMU && ENABLE_HUSH_LOCAL
1756 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1757 set_local_var(str, flg_export, local_lvl)
1758 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1759 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1760 set_local_var(str, flg_export)
1761 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1762 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1763 set_local_var(str, flg_export, flg_read_only)
1765 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1767 struct variable **var_pp;
1768 struct variable *cur;
1772 eq_sign = strchr(str, '=');
1773 if (!eq_sign) { /* not expected to ever happen? */
1778 name_len = eq_sign - str + 1; /* including '=' */
1779 var_pp = &G.top_var;
1780 while ((cur = *var_pp) != NULL) {
1781 if (strncmp(cur->varstr, str, name_len) != 0) {
1782 var_pp = &cur->next;
1785 /* We found an existing var with this name */
1786 if (cur->flg_read_only) {
1790 bb_error_msg("%s: readonly variable", str);
1794 if (flg_export == -1) { // "&& cur->flg_export" ?
1795 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1800 #if ENABLE_HUSH_LOCAL
1801 if (cur->func_nest_level < local_lvl) {
1802 /* New variable is declared as local,
1803 * and existing one is global, or local
1804 * from enclosing function.
1805 * Remove and save old one: */
1806 *var_pp = cur->next;
1807 cur->next = *G.shadowed_vars_pp;
1808 *G.shadowed_vars_pp = cur;
1809 /* bash 3.2.33(1) and exported vars:
1811 * # f() { local z=a; env | grep ^z; }
1817 if (cur->flg_export)
1822 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1827 if (cur->max_len != 0) {
1828 if (cur->max_len >= strlen(str)) {
1829 /* This one is from startup env, reuse space */
1830 strcpy(cur->varstr, str);
1834 /* max_len == 0 signifies "malloced" var, which we can
1835 * (and has to) free */
1839 goto set_str_and_exp;
1842 /* Not found - create new variable struct */
1843 cur = xzalloc(sizeof(*cur));
1844 #if ENABLE_HUSH_LOCAL
1845 cur->func_nest_level = local_lvl;
1847 cur->next = *var_pp;
1853 cur->flg_read_only = flg_read_only;
1856 if (flg_export == 1)
1857 cur->flg_export = 1;
1858 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1859 cmdedit_update_prompt();
1860 if (cur->flg_export) {
1861 if (flg_export == -1) {
1862 cur->flg_export = 0;
1863 /* unsetenv was already done */
1865 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1866 return putenv(cur->varstr);
1872 /* Used at startup and after each cd */
1873 static void set_pwd_var(int exp)
1875 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1876 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
1879 static int unset_local_var_len(const char *name, int name_len)
1881 struct variable *cur;
1882 struct variable **var_pp;
1885 return EXIT_SUCCESS;
1886 var_pp = &G.top_var;
1887 while ((cur = *var_pp) != NULL) {
1888 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
1889 if (cur->flg_read_only) {
1890 bb_error_msg("%s: readonly variable", name);
1891 return EXIT_FAILURE;
1893 *var_pp = cur->next;
1894 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
1895 bb_unsetenv(cur->varstr);
1896 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1897 cmdedit_update_prompt();
1901 return EXIT_SUCCESS;
1903 var_pp = &cur->next;
1905 return EXIT_SUCCESS;
1908 static int unset_local_var(const char *name)
1910 return unset_local_var_len(name, strlen(name));
1913 static void unset_vars(char **strings)
1921 const char *eq = strchrnul(*v, '=');
1922 unset_local_var_len(*v, (int)(eq - *v));
1928 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
1930 char *var = xasprintf("%s=%s", name, val);
1931 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
1936 * Helpers for "var1=val1 var2=val2 cmd" feature
1938 static void add_vars(struct variable *var)
1940 struct variable *next;
1944 var->next = G.top_var;
1946 if (var->flg_export) {
1947 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
1948 putenv(var->varstr);
1950 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
1956 static struct variable *set_vars_and_save_old(char **strings)
1959 struct variable *old = NULL;
1965 struct variable *var_p;
1966 struct variable **var_pp;
1969 eq = strchr(*s, '=');
1971 var_pp = get_ptr_to_local_var(*s, eq - *s);
1973 /* Remove variable from global linked list */
1975 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
1976 *var_pp = var_p->next;
1977 /* Add it to returned list */
1981 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
1992 static void reinit_unicode_for_hush(void)
1994 /* Unicode support should be activated even if LANG is set
1995 * _during_ shell execution, not only if it was set when
1996 * shell was started. Therefore, re-check LANG every time:
1998 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
1999 || ENABLE_UNICODE_USING_LOCALE
2001 const char *s = get_local_var_value("LC_ALL");
2002 if (!s) s = get_local_var_value("LC_CTYPE");
2003 if (!s) s = get_local_var_value("LANG");
2012 static int FAST_FUNC static_get(struct in_str *i)
2023 static int FAST_FUNC static_peek(struct in_str *i)
2028 #if ENABLE_HUSH_INTERACTIVE
2030 static void cmdedit_update_prompt(void)
2032 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2033 G.PS1 = get_local_var_value("PS1");
2036 G.PS2 = get_local_var_value("PS2");
2044 static const char *setup_prompt_string(int promptmode)
2046 const char *prompt_str;
2047 debug_printf("setup_prompt_string %d ", promptmode);
2048 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2049 /* Set up the prompt */
2050 if (promptmode == 0) { /* PS1 */
2052 /* bash uses $PWD value, even if it is set by user.
2053 * It uses current dir only if PWD is unset.
2054 * We always use current dir. */
2055 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2060 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2061 debug_printf("result '%s'\n", prompt_str);
2065 static void get_user_input(struct in_str *i)
2068 const char *prompt_str;
2070 prompt_str = setup_prompt_string(i->promptmode);
2071 # if ENABLE_FEATURE_EDITING
2072 /* Enable command line editing only while a command line
2073 * is actually being read */
2075 reinit_unicode_for_hush();
2077 /* buglet: SIGINT will not make new prompt to appear _at once_,
2078 * only after <Enter>. (^C will work) */
2079 r = read_line_input(G.line_input_state, prompt_str, G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1, /*timeout*/ -1);
2080 /* catch *SIGINT* etc (^C is handled by read_line_input) */
2081 check_and_run_traps();
2082 } while (r == 0 || G.flag_SIGINT); /* repeat if ^C or SIGINT */
2083 i->eof_flag = (r < 0);
2084 if (i->eof_flag) { /* EOF/error detected */
2085 G.user_input_buf[0] = EOF; /* yes, it will be truncated, it's ok */
2086 G.user_input_buf[1] = '\0';
2091 if (i->last_char == '\0' || i->last_char == '\n') {
2092 /* Why check_and_run_traps here? Try this interactively:
2093 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2094 * $ <[enter], repeatedly...>
2095 * Without check_and_run_traps, handler never runs.
2097 check_and_run_traps();
2098 fputs(prompt_str, stdout);
2101 G.user_input_buf[0] = r = fgetc(i->file);
2102 /*G.user_input_buf[1] = '\0'; - already is and never changed */
2103 } while (G.flag_SIGINT);
2104 i->eof_flag = (r == EOF);
2106 i->p = G.user_input_buf;
2109 #endif /* INTERACTIVE */
2111 /* This is the magic location that prints prompts
2112 * and gets data back from the user */
2113 static int FAST_FUNC file_get(struct in_str *i)
2117 /* If there is data waiting, eat it up */
2118 if (i->p && *i->p) {
2119 #if ENABLE_HUSH_INTERACTIVE
2123 if (i->eof_flag && !*i->p)
2125 /* note: ch is never NUL */
2127 /* need to double check i->file because we might be doing something
2128 * more complicated by now, like sourcing or substituting. */
2129 #if ENABLE_HUSH_INTERACTIVE
2130 if (G_interactive_fd && i->file == stdin) {
2133 } while (!*i->p); /* need non-empty line */
2134 i->promptmode = 1; /* PS2 */
2138 do ch = fgetc(i->file); while (ch == '\0');
2140 debug_printf("file_get: got '%c' %d\n", ch, ch);
2145 /* All callers guarantee this routine will never
2146 * be used right after a newline, so prompting is not needed.
2148 static int FAST_FUNC file_peek(struct in_str *i)
2151 if (i->p && *i->p) {
2152 if (i->eof_flag && !i->p[1])
2155 /* note: ch is never NUL */
2157 do ch = fgetc(i->file); while (ch == '\0');
2158 i->eof_flag = (ch == EOF);
2159 i->peek_buf[0] = ch;
2160 i->peek_buf[1] = '\0';
2162 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2166 static void setup_file_in_str(struct in_str *i, FILE *f)
2168 memset(i, 0, sizeof(*i));
2169 i->peek = file_peek;
2171 /* i->promptmode = 0; - PS1 (memset did it) */
2176 static void setup_string_in_str(struct in_str *i, const char *s)
2178 memset(i, 0, sizeof(*i));
2179 i->peek = static_peek;
2180 i->get = static_get;
2181 /* i->promptmode = 0; - PS1 (memset did it) */
2183 /* i->eof_flag = 0; */
2190 #define B_CHUNK (32 * sizeof(char*))
2192 static void o_reset_to_empty_unquoted(o_string *o)
2195 o->has_quoted_part = 0;
2200 static void o_free(o_string *o)
2203 memset(o, 0, sizeof(*o));
2206 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2211 static void o_grow_by(o_string *o, int len)
2213 if (o->length + len > o->maxlen) {
2214 o->maxlen += (2*len > B_CHUNK ? 2*len : B_CHUNK);
2215 o->data = xrealloc(o->data, 1 + o->maxlen);
2219 static void o_addchr(o_string *o, int ch)
2221 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2223 o->data[o->length] = ch;
2225 o->data[o->length] = '\0';
2228 static void o_addblock(o_string *o, const char *str, int len)
2231 memcpy(&o->data[o->length], str, len);
2233 o->data[o->length] = '\0';
2236 static void o_addstr(o_string *o, const char *str)
2238 o_addblock(o, str, strlen(str));
2242 static void nommu_addchr(o_string *o, int ch)
2248 # define nommu_addchr(o, str) ((void)0)
2251 static void o_addstr_with_NUL(o_string *o, const char *str)
2253 o_addblock(o, str, strlen(str) + 1);
2257 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2258 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2259 * Apparently, on unquoted $v bash still does globbing
2260 * ("v='*.txt'; echo $v" prints all .txt files),
2261 * but NOT brace expansion! Thus, there should be TWO independent
2262 * quoting mechanisms on $v expansion side: one protects
2263 * $v from brace expansion, and other additionally protects "$v" against globbing.
2264 * We have only second one.
2267 #if ENABLE_HUSH_BRACE_EXPANSION
2268 # define MAYBE_BRACES "{}"
2270 # define MAYBE_BRACES ""
2273 /* My analysis of quoting semantics tells me that state information
2274 * is associated with a destination, not a source.
2276 static void o_addqchr(o_string *o, int ch)
2279 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2284 o->data[o->length] = '\\';
2287 o->data[o->length] = ch;
2289 o->data[o->length] = '\0';
2292 static void o_addQchr(o_string *o, int ch)
2295 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2296 && strchr("*?[\\" MAYBE_BRACES, ch)
2299 o->data[o->length] = '\\';
2303 o->data[o->length] = ch;
2305 o->data[o->length] = '\0';
2308 static void o_addqblock(o_string *o, const char *str, int len)
2313 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2314 if (ordinary_cnt > len) /* paranoia */
2316 o_addblock(o, str, ordinary_cnt);
2317 if (ordinary_cnt == len)
2318 return; /* NUL is already added by o_addblock */
2319 str += ordinary_cnt;
2320 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2324 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2326 o->data[o->length] = '\\';
2330 o->data[o->length] = ch;
2333 o->data[o->length] = '\0';
2336 static void o_addQblock(o_string *o, const char *str, int len)
2338 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2339 o_addblock(o, str, len);
2342 o_addqblock(o, str, len);
2345 static void o_addQstr(o_string *o, const char *str)
2347 o_addQblock(o, str, strlen(str));
2350 /* A special kind of o_string for $VAR and `cmd` expansion.
2351 * It contains char* list[] at the beginning, which is grown in 16 element
2352 * increments. Actual string data starts at the next multiple of 16 * (char*).
2353 * list[i] contains an INDEX (int!) into this string data.
2354 * It means that if list[] needs to grow, data needs to be moved higher up
2355 * but list[i]'s need not be modified.
2356 * NB: remembering how many list[i]'s you have there is crucial.
2357 * o_finalize_list() operation post-processes this structure - calculates
2358 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2360 #if DEBUG_EXPAND || DEBUG_GLOB
2361 static void debug_print_list(const char *prefix, o_string *o, int n)
2363 char **list = (char**)o->data;
2364 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2368 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2369 prefix, list, n, string_start, o->length, o->maxlen,
2370 !!(o->o_expflags & EXP_FLAG_GLOB),
2372 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2375 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2376 o->data + (int)(uintptr_t)list[i] + string_start,
2377 o->data + (int)(uintptr_t)list[i] + string_start);
2381 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2383 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2387 # define debug_print_list(prefix, o, n) ((void)0)
2390 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2391 * in list[n] so that it points past last stored byte so far.
2392 * It returns n+1. */
2393 static int o_save_ptr_helper(o_string *o, int n)
2395 char **list = (char**)o->data;
2399 if (!o->has_empty_slot) {
2400 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2401 string_len = o->length - string_start;
2402 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2403 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2404 /* list[n] points to string_start, make space for 16 more pointers */
2405 o->maxlen += 0x10 * sizeof(list[0]);
2406 o->data = xrealloc(o->data, o->maxlen + 1);
2407 list = (char**)o->data;
2408 memmove(list + n + 0x10, list + n, string_len);
2409 o->length += 0x10 * sizeof(list[0]);
2411 debug_printf_list("list[%d]=%d string_start=%d\n",
2412 n, string_len, string_start);
2415 /* We have empty slot at list[n], reuse without growth */
2416 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2417 string_len = o->length - string_start;
2418 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2419 n, string_len, string_start);
2420 o->has_empty_slot = 0;
2422 o->has_quoted_part = 0;
2423 list[n] = (char*)(uintptr_t)string_len;
2427 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2428 static int o_get_last_ptr(o_string *o, int n)
2430 char **list = (char**)o->data;
2431 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2433 return ((int)(uintptr_t)list[n-1]) + string_start;
2436 #if ENABLE_HUSH_BRACE_EXPANSION
2437 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2438 * first, it processes even {a} (no commas), second,
2439 * I didn't manage to make it return strings when they don't match
2440 * existing files. Need to re-implement it.
2444 static int glob_needed(const char *s)
2453 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2459 /* Return pointer to next closing brace or to comma */
2460 static const char *next_brace_sub(const char *cp)
2464 while (*cp != '\0') {
2471 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2477 return *cp != '\0' ? cp : NULL;
2479 /* Recursive brace globber. Note: may garble pattern[]. */
2480 static int glob_brace(char *pattern, o_string *o, int n)
2482 char *new_pattern_buf;
2489 debug_printf_glob("glob_brace('%s')\n", pattern);
2495 if (*begin == '{') {
2496 /* Find the first sub-pattern and at the same time
2497 * find the rest after the closing brace */
2498 next = next_brace_sub(begin);
2500 /* An illegal expression */
2504 /* "{abc}" with no commas - illegal
2505 * brace expr, disregard and skip it */
2511 if (*begin == '\\' && begin[1] != '\0')
2515 debug_printf_glob("begin:%s\n", begin);
2516 debug_printf_glob("next:%s\n", next);
2518 /* Now find the end of the whole brace expression */
2520 while (*rest != '}') {
2521 rest = next_brace_sub(rest);
2523 /* An illegal expression */
2526 debug_printf_glob("rest:%s\n", rest);
2528 rest_len = strlen(++rest) + 1;
2530 /* We are sure the brace expression is well-formed */
2532 /* Allocate working buffer large enough for our work */
2533 new_pattern_buf = xmalloc(strlen(pattern));
2535 /* We have a brace expression. BEGIN points to the opening {,
2536 * NEXT points past the terminator of the first element, and REST
2537 * points past the final }. We will accumulate result names from
2538 * recursive runs for each brace alternative in the buffer using
2543 /* Construct the new glob expression */
2546 mempcpy(new_pattern_buf,
2547 /* We know the prefix for all sub-patterns */
2548 pattern, begin - pattern),
2552 /* Note: glob_brace() may garble new_pattern_buf[].
2553 * That's why we re-copy prefix every time (1st memcpy above).
2555 n = glob_brace(new_pattern_buf, o, n);
2557 /* We saw the last entry */
2561 next = next_brace_sub(next);
2563 free(new_pattern_buf);
2571 memset(&globdata, 0, sizeof(globdata));
2572 gr = glob(pattern, 0, NULL, &globdata);
2573 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2575 if (gr == GLOB_NOMATCH) {
2576 globfree(&globdata);
2577 /* NB: garbles parameter */
2578 unbackslash(pattern);
2579 o_addstr_with_NUL(o, pattern);
2580 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2581 return o_save_ptr_helper(o, n);
2583 if (gr == GLOB_NOSPACE)
2584 bb_error_msg_and_die(bb_msg_memory_exhausted);
2585 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2586 * but we didn't specify it. Paranoia again. */
2587 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2589 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2590 char **argv = globdata.gl_pathv;
2592 o_addstr_with_NUL(o, *argv);
2593 n = o_save_ptr_helper(o, n);
2599 globfree(&globdata);
2603 /* Performs globbing on last list[],
2604 * saving each result as a new list[].
2606 static int perform_glob(o_string *o, int n)
2608 char *pattern, *copy;
2610 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2612 return o_save_ptr_helper(o, n);
2613 pattern = o->data + o_get_last_ptr(o, n);
2614 debug_printf_glob("glob pattern '%s'\n", pattern);
2615 if (!glob_needed(pattern)) {
2616 /* unbackslash last string in o in place, fix length */
2617 o->length = unbackslash(pattern) - o->data;
2618 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2619 return o_save_ptr_helper(o, n);
2622 copy = xstrdup(pattern);
2623 /* "forget" pattern in o */
2624 o->length = pattern - o->data;
2625 n = glob_brace(copy, o, n);
2628 debug_print_list("perform_glob returning", o, n);
2632 #else /* !HUSH_BRACE_EXPANSION */
2635 static int glob_needed(const char *s)
2644 if (*s == '*' || *s == '[' || *s == '?')
2650 /* Performs globbing on last list[],
2651 * saving each result as a new list[].
2653 static int perform_glob(o_string *o, int n)
2659 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2661 return o_save_ptr_helper(o, n);
2662 pattern = o->data + o_get_last_ptr(o, n);
2663 debug_printf_glob("glob pattern '%s'\n", pattern);
2664 if (!glob_needed(pattern)) {
2666 /* unbackslash last string in o in place, fix length */
2667 o->length = unbackslash(pattern) - o->data;
2668 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2669 return o_save_ptr_helper(o, n);
2672 memset(&globdata, 0, sizeof(globdata));
2673 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2674 * If we glob "*.\*" and don't find anything, we need
2675 * to fall back to using literal "*.*", but GLOB_NOCHECK
2676 * will return "*.\*"!
2678 gr = glob(pattern, 0, NULL, &globdata);
2679 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2681 if (gr == GLOB_NOMATCH) {
2682 globfree(&globdata);
2685 if (gr == GLOB_NOSPACE)
2686 bb_error_msg_and_die(bb_msg_memory_exhausted);
2687 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2688 * but we didn't specify it. Paranoia again. */
2689 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2691 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2692 char **argv = globdata.gl_pathv;
2693 /* "forget" pattern in o */
2694 o->length = pattern - o->data;
2696 o_addstr_with_NUL(o, *argv);
2697 n = o_save_ptr_helper(o, n);
2703 globfree(&globdata);
2705 debug_print_list("perform_glob returning", o, n);
2709 #endif /* !HUSH_BRACE_EXPANSION */
2711 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2712 * Otherwise, just finish current list[] and start new */
2713 static int o_save_ptr(o_string *o, int n)
2715 if (o->o_expflags & EXP_FLAG_GLOB) {
2716 /* If o->has_empty_slot, list[n] was already globbed
2717 * (if it was requested back then when it was filled)
2718 * so don't do that again! */
2719 if (!o->has_empty_slot)
2720 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2722 return o_save_ptr_helper(o, n);
2725 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2726 static char **o_finalize_list(o_string *o, int n)
2731 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2733 debug_print_list("finalized", o, n);
2734 debug_printf_expand("finalized n:%d\n", n);
2735 list = (char**)o->data;
2736 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2740 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2745 static void free_pipe_list(struct pipe *pi);
2747 /* Returns pi->next - next pipe in the list */
2748 static struct pipe *free_pipe(struct pipe *pi)
2753 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2754 for (i = 0; i < pi->num_cmds; i++) {
2755 struct command *command;
2756 struct redir_struct *r, *rnext;
2758 command = &pi->cmds[i];
2759 debug_printf_clean(" command %d:\n", i);
2760 if (command->argv) {
2764 for (a = 0, p = command->argv; *p; a++, p++) {
2765 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2768 free_strings(command->argv);
2769 //command->argv = NULL;
2771 /* not "else if": on syntax error, we may have both! */
2772 if (command->group) {
2773 debug_printf_clean(" begin group (cmd_type:%d)\n",
2775 free_pipe_list(command->group);
2776 debug_printf_clean(" end group\n");
2777 //command->group = NULL;
2779 /* else is crucial here.
2780 * If group != NULL, child_func is meaningless */
2781 #if ENABLE_HUSH_FUNCTIONS
2782 else if (command->child_func) {
2783 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
2784 command->child_func->parent_cmd = NULL;
2788 free(command->group_as_string);
2789 //command->group_as_string = NULL;
2791 for (r = command->redirects; r; r = rnext) {
2792 debug_printf_clean(" redirect %d%s",
2793 r->rd_fd, redir_table[r->rd_type].descrip);
2794 /* guard against the case >$FOO, where foo is unset or blank */
2795 if (r->rd_filename) {
2796 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
2797 free(r->rd_filename);
2798 //r->rd_filename = NULL;
2800 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
2804 //command->redirects = NULL;
2806 free(pi->cmds); /* children are an array, they get freed all at once */
2810 //pi->cmdtext = NULL;
2818 static void free_pipe_list(struct pipe *pi)
2822 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
2824 debug_printf_clean("pipe followup code %d\n", pi->followup);
2830 /*** Parsing routines ***/
2832 #ifndef debug_print_tree
2833 static void debug_print_tree(struct pipe *pi, int lvl)
2835 static const char *const PIPE[] = {
2841 static const char *RES[] = {
2842 [RES_NONE ] = "NONE" ,
2845 [RES_THEN ] = "THEN" ,
2846 [RES_ELIF ] = "ELIF" ,
2847 [RES_ELSE ] = "ELSE" ,
2850 # if ENABLE_HUSH_LOOPS
2851 [RES_FOR ] = "FOR" ,
2852 [RES_WHILE] = "WHILE",
2853 [RES_UNTIL] = "UNTIL",
2855 [RES_DONE ] = "DONE" ,
2857 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
2860 # if ENABLE_HUSH_CASE
2861 [RES_CASE ] = "CASE" ,
2862 [RES_CASE_IN ] = "CASE_IN" ,
2863 [RES_MATCH] = "MATCH",
2864 [RES_CASE_BODY] = "CASE_BODY",
2865 [RES_ESAC ] = "ESAC" ,
2867 [RES_XXXX ] = "XXXX" ,
2868 [RES_SNTX ] = "SNTX" ,
2870 static const char *const CMDTYPE[] = {
2874 # if ENABLE_HUSH_FUNCTIONS
2883 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
2884 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
2886 while (prn < pi->num_cmds) {
2887 struct command *command = &pi->cmds[prn];
2888 char **argv = command->argv;
2890 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
2892 command->assignment_cnt);
2893 if (command->group) {
2894 fdprintf(2, " group %s: (argv=%p)%s%s\n",
2895 CMDTYPE[command->cmd_type],
2898 , " group_as_string:", command->group_as_string
2903 debug_print_tree(command->group, lvl+1);
2907 if (argv) while (*argv) {
2908 fdprintf(2, " '%s'", *argv);
2918 #endif /* debug_print_tree */
2920 static struct pipe *new_pipe(void)
2923 pi = xzalloc(sizeof(struct pipe));
2924 /*pi->followup = 0; - deliberately invalid value */
2925 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
2929 /* Command (member of a pipe) is complete, or we start a new pipe
2930 * if ctx->command is NULL.
2931 * No errors possible here.
2933 static int done_command(struct parse_context *ctx)
2935 /* The command is really already in the pipe structure, so
2936 * advance the pipe counter and make a new, null command. */
2937 struct pipe *pi = ctx->pipe;
2938 struct command *command = ctx->command;
2941 if (IS_NULL_CMD(command)) {
2942 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
2946 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
2947 //debug_print_tree(ctx->list_head, 20);
2949 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
2952 /* Only real trickiness here is that the uncommitted
2953 * command structure is not counted in pi->num_cmds. */
2954 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
2955 ctx->command = command = &pi->cmds[pi->num_cmds];
2957 memset(command, 0, sizeof(*command));
2958 return pi->num_cmds; /* used only for 0/nonzero check */
2961 static void done_pipe(struct parse_context *ctx, pipe_style type)
2965 debug_printf_parse("done_pipe entered, followup %d\n", type);
2966 /* Close previous command */
2967 not_null = done_command(ctx);
2968 ctx->pipe->followup = type;
2970 ctx->pipe->pi_inverted = ctx->ctx_inverted;
2971 ctx->ctx_inverted = 0;
2972 ctx->pipe->res_word = ctx->ctx_res_w;
2975 /* Without this check, even just <enter> on command line generates
2976 * tree of three NOPs (!). Which is harmless but annoying.
2977 * IOW: it is safe to do it unconditionally. */
2980 || ctx->ctx_res_w == RES_FI
2982 #if ENABLE_HUSH_LOOPS
2983 || ctx->ctx_res_w == RES_DONE
2984 || ctx->ctx_res_w == RES_FOR
2985 || ctx->ctx_res_w == RES_IN
2987 #if ENABLE_HUSH_CASE
2988 || ctx->ctx_res_w == RES_ESAC
2992 debug_printf_parse("done_pipe: adding new pipe: "
2993 "not_null:%d ctx->ctx_res_w:%d\n",
2994 not_null, ctx->ctx_res_w);
2996 ctx->pipe->next = new_p;
2998 /* RES_THEN, RES_DO etc are "sticky" -
2999 * they remain set for pipes inside if/while.
3000 * This is used to control execution.
3001 * RES_FOR and RES_IN are NOT sticky (needed to support
3002 * cases where variable or value happens to match a keyword):
3004 #if ENABLE_HUSH_LOOPS
3005 if (ctx->ctx_res_w == RES_FOR
3006 || ctx->ctx_res_w == RES_IN)
3007 ctx->ctx_res_w = RES_NONE;
3009 #if ENABLE_HUSH_CASE
3010 if (ctx->ctx_res_w == RES_MATCH)
3011 ctx->ctx_res_w = RES_CASE_BODY;
3012 if (ctx->ctx_res_w == RES_CASE)
3013 ctx->ctx_res_w = RES_CASE_IN;
3015 ctx->command = NULL; /* trick done_command below */
3016 /* Create the memory for command, roughly:
3017 * ctx->pipe->cmds = new struct command;
3018 * ctx->command = &ctx->pipe->cmds[0];
3021 //debug_print_tree(ctx->list_head, 10);
3023 debug_printf_parse("done_pipe return\n");
3026 static void initialize_context(struct parse_context *ctx)
3028 memset(ctx, 0, sizeof(*ctx));
3029 ctx->pipe = ctx->list_head = new_pipe();
3030 /* Create the memory for command, roughly:
3031 * ctx->pipe->cmds = new struct command;
3032 * ctx->command = &ctx->pipe->cmds[0];
3037 /* If a reserved word is found and processed, parse context is modified
3038 * and 1 is returned.
3041 struct reserved_combo {
3044 unsigned char assignment_flag;
3048 FLAG_END = (1 << RES_NONE ),
3050 FLAG_IF = (1 << RES_IF ),
3051 FLAG_THEN = (1 << RES_THEN ),
3052 FLAG_ELIF = (1 << RES_ELIF ),
3053 FLAG_ELSE = (1 << RES_ELSE ),
3054 FLAG_FI = (1 << RES_FI ),
3056 # if ENABLE_HUSH_LOOPS
3057 FLAG_FOR = (1 << RES_FOR ),
3058 FLAG_WHILE = (1 << RES_WHILE),
3059 FLAG_UNTIL = (1 << RES_UNTIL),
3060 FLAG_DO = (1 << RES_DO ),
3061 FLAG_DONE = (1 << RES_DONE ),
3062 FLAG_IN = (1 << RES_IN ),
3064 # if ENABLE_HUSH_CASE
3065 FLAG_MATCH = (1 << RES_MATCH),
3066 FLAG_ESAC = (1 << RES_ESAC ),
3068 FLAG_START = (1 << RES_XXXX ),
3071 static const struct reserved_combo* match_reserved_word(o_string *word)
3073 /* Mostly a list of accepted follow-up reserved words.
3074 * FLAG_END means we are done with the sequence, and are ready
3075 * to turn the compound list into a command.
3076 * FLAG_START means the word must start a new compound list.
3078 static const struct reserved_combo reserved_list[] = {
3080 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3081 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3082 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3083 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3084 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3085 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3087 # if ENABLE_HUSH_LOOPS
3088 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3089 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3090 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3091 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3092 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3093 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3095 # if ENABLE_HUSH_CASE
3096 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3097 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3100 const struct reserved_combo *r;
3102 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3103 if (strcmp(word->data, r->literal) == 0)
3108 /* Return 0: not a keyword, 1: keyword
3110 static int reserved_word(o_string *word, struct parse_context *ctx)
3112 # if ENABLE_HUSH_CASE
3113 static const struct reserved_combo reserved_match = {
3114 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3117 const struct reserved_combo *r;
3119 if (word->has_quoted_part)
3121 r = match_reserved_word(word);
3125 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3126 # if ENABLE_HUSH_CASE
3127 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3128 /* "case word IN ..." - IN part starts first MATCH part */
3129 r = &reserved_match;
3132 if (r->flag == 0) { /* '!' */
3133 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3134 syntax_error("! ! command");
3135 ctx->ctx_res_w = RES_SNTX;
3137 ctx->ctx_inverted = 1;
3140 if (r->flag & FLAG_START) {
3141 struct parse_context *old;
3143 old = xmalloc(sizeof(*old));
3144 debug_printf_parse("push stack %p\n", old);
3145 *old = *ctx; /* physical copy */
3146 initialize_context(ctx);
3148 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3149 syntax_error_at(word->data);
3150 ctx->ctx_res_w = RES_SNTX;
3153 /* "{...} fi" is ok. "{...} if" is not
3155 * if { echo foo; } then { echo bar; } fi */
3156 if (ctx->command->group)
3157 done_pipe(ctx, PIPE_SEQ);
3160 ctx->ctx_res_w = r->res;
3161 ctx->old_flag = r->flag;
3162 word->o_assignment = r->assignment_flag;
3163 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3165 if (ctx->old_flag & FLAG_END) {
3166 struct parse_context *old;
3168 done_pipe(ctx, PIPE_SEQ);
3169 debug_printf_parse("pop stack %p\n", ctx->stack);
3171 old->command->group = ctx->list_head;
3172 old->command->cmd_type = CMD_NORMAL;
3174 /* At this point, the compound command's string is in
3175 * ctx->as_string... except for the leading keyword!
3176 * Consider this example: "echo a | if true; then echo a; fi"
3177 * ctx->as_string will contain "true; then echo a; fi",
3178 * with "if " remaining in old->as_string!
3182 int len = old->as_string.length;
3183 /* Concatenate halves */
3184 o_addstr(&old->as_string, ctx->as_string.data);
3185 o_free_unsafe(&ctx->as_string);
3186 /* Find where leading keyword starts in first half */
3187 str = old->as_string.data + len;
3188 if (str > old->as_string.data)
3189 str--; /* skip whitespace after keyword */
3190 while (str > old->as_string.data && isalpha(str[-1]))
3192 /* Ugh, we're done with this horrid hack */
3193 old->command->group_as_string = xstrdup(str);
3194 debug_printf_parse("pop, remembering as:'%s'\n",
3195 old->command->group_as_string);
3198 *ctx = *old; /* physical copy */
3203 #endif /* HAS_KEYWORDS */
3205 /* Word is complete, look at it and update parsing context.
3206 * Normal return is 0. Syntax errors return 1.
3207 * Note: on return, word is reset, but not o_free'd!
3209 static int done_word(o_string *word, struct parse_context *ctx)
3211 struct command *command = ctx->command;
3213 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3214 if (word->length == 0 && !word->has_quoted_part) {
3215 debug_printf_parse("done_word return 0: true null, ignored\n");
3219 if (ctx->pending_redirect) {
3220 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3221 * only if run as "bash", not "sh" */
3222 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3224 * ...the word that follows the redirection operator
3225 * shall be subjected to tilde expansion, parameter expansion,
3226 * command substitution, arithmetic expansion, and quote
3227 * removal. Pathname expansion shall not be performed
3228 * on the word by a non-interactive shell; an interactive
3229 * shell may perform it, but shall do so only when
3230 * the expansion would result in one word."
3232 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3233 /* Cater for >\file case:
3234 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3235 * Same with heredocs:
3236 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3238 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3239 unbackslash(ctx->pending_redirect->rd_filename);
3240 /* Is it <<"HEREDOC"? */
3241 if (word->has_quoted_part) {
3242 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3245 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3246 ctx->pending_redirect = NULL;
3249 # if ENABLE_HUSH_CASE
3250 if (ctx->ctx_dsemicolon
3251 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3253 /* already done when ctx_dsemicolon was set to 1: */
3254 /* ctx->ctx_res_w = RES_MATCH; */
3255 ctx->ctx_dsemicolon = 0;
3258 if (!command->argv /* if it's the first word... */
3259 # if ENABLE_HUSH_LOOPS
3260 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3261 && ctx->ctx_res_w != RES_IN
3263 # if ENABLE_HUSH_CASE
3264 && ctx->ctx_res_w != RES_CASE
3267 int reserved = reserved_word(word, ctx);
3268 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3270 o_reset_to_empty_unquoted(word);
3271 debug_printf_parse("done_word return %d\n",
3272 (ctx->ctx_res_w == RES_SNTX));
3273 return (ctx->ctx_res_w == RES_SNTX);
3275 # if ENABLE_HUSH_BASH_COMPAT
3276 if (strcmp(word->data, "[[") == 0) {
3277 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3283 if (command->group) {
3284 /* "{ echo foo; } echo bar" - bad */
3285 syntax_error_at(word->data);
3286 debug_printf_parse("done_word return 1: syntax error, "
3287 "groups and arglists don't mix\n");
3291 /* If this word wasn't an assignment, next ones definitely
3292 * can't be assignments. Even if they look like ones. */
3293 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3294 && word->o_assignment != WORD_IS_KEYWORD
3296 word->o_assignment = NOT_ASSIGNMENT;
3298 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3299 command->assignment_cnt++;
3300 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3302 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3303 word->o_assignment = MAYBE_ASSIGNMENT;
3305 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3307 if (word->has_quoted_part
3308 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3309 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3310 /* (otherwise it's known to be not empty and is already safe) */
3312 /* exclude "$@" - it can expand to no word despite "" */
3313 char *p = word->data;
3314 while (p[0] == SPECIAL_VAR_SYMBOL
3315 && (p[1] & 0x7f) == '@'
3316 && p[2] == SPECIAL_VAR_SYMBOL
3321 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3322 debug_print_strings("word appended to argv", command->argv);
3325 #if ENABLE_HUSH_LOOPS
3326 if (ctx->ctx_res_w == RES_FOR) {
3327 if (word->has_quoted_part
3328 || !is_well_formed_var_name(command->argv[0], '\0')
3330 /* bash says just "not a valid identifier" */
3331 syntax_error("not a valid identifier in for");
3334 /* Force FOR to have just one word (variable name) */
3335 /* NB: basically, this makes hush see "for v in ..."
3336 * syntax as if it is "for v; in ...". FOR and IN become
3337 * two pipe structs in parse tree. */
3338 done_pipe(ctx, PIPE_SEQ);
3341 #if ENABLE_HUSH_CASE
3342 /* Force CASE to have just one word */
3343 if (ctx->ctx_res_w == RES_CASE) {
3344 done_pipe(ctx, PIPE_SEQ);
3348 o_reset_to_empty_unquoted(word);
3350 debug_printf_parse("done_word return 0\n");
3355 /* Peek ahead in the input to find out if we have a "&n" construct,
3356 * as in "2>&1", that represents duplicating a file descriptor.
3358 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3359 * REDIRFD_SYNTAX_ERR if syntax error,
3360 * REDIRFD_TO_FILE if no & was seen,
3361 * or the number found.
3364 #define parse_redir_right_fd(as_string, input) \
3365 parse_redir_right_fd(input)
3367 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3373 return REDIRFD_TO_FILE;
3375 ch = i_getch(input); /* get the & */
3376 nommu_addchr(as_string, ch);
3379 ch = i_getch(input);
3380 nommu_addchr(as_string, ch);
3381 return REDIRFD_CLOSE;
3385 while (ch != EOF && isdigit(ch)) {
3386 d = d*10 + (ch-'0');
3388 ch = i_getch(input);
3389 nommu_addchr(as_string, ch);
3394 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3396 bb_error_msg("ambiguous redirect");
3397 return REDIRFD_SYNTAX_ERR;
3400 /* Return code is 0 normal, 1 if a syntax error is detected
3402 static int parse_redirect(struct parse_context *ctx,
3405 struct in_str *input)
3407 struct command *command = ctx->command;
3408 struct redir_struct *redir;
3409 struct redir_struct **redirp;
3412 dup_num = REDIRFD_TO_FILE;
3413 if (style != REDIRECT_HEREDOC) {
3414 /* Check for a '>&1' type redirect */
3415 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3416 if (dup_num == REDIRFD_SYNTAX_ERR)
3419 int ch = i_peek(input);
3420 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3421 if (dup_num) { /* <<-... */
3422 ch = i_getch(input);
3423 nommu_addchr(&ctx->as_string, ch);
3428 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3429 int ch = i_peek(input);
3431 /* >|FILE redirect ("clobbering" >).
3432 * Since we do not support "set -o noclobber" yet,
3433 * >| and > are the same for now. Just eat |.
3435 ch = i_getch(input);
3436 nommu_addchr(&ctx->as_string, ch);
3440 /* Create a new redir_struct and append it to the linked list */
3441 redirp = &command->redirects;
3442 while ((redir = *redirp) != NULL) {
3443 redirp = &(redir->next);
3445 *redirp = redir = xzalloc(sizeof(*redir));
3446 /* redir->next = NULL; */
3447 /* redir->rd_filename = NULL; */
3448 redir->rd_type = style;
3449 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3451 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3452 redir_table[style].descrip);
3454 redir->rd_dup = dup_num;
3455 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3456 /* Erik had a check here that the file descriptor in question
3457 * is legit; I postpone that to "run time"
3458 * A "-" representation of "close me" shows up as a -3 here */
3459 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3460 redir->rd_fd, redir->rd_dup);
3462 /* Set ctx->pending_redirect, so we know what to do at the
3463 * end of the next parsed word. */
3464 ctx->pending_redirect = redir;
3469 /* If a redirect is immediately preceded by a number, that number is
3470 * supposed to tell which file descriptor to redirect. This routine
3471 * looks for such preceding numbers. In an ideal world this routine
3472 * needs to handle all the following classes of redirects...
3473 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3474 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3475 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3476 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3478 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3480 * ... If n is quoted, the number shall not be recognized as part of
3481 * the redirection expression. For example:
3483 * writes the character 2 into file a"
3484 * We are getting it right by setting ->has_quoted_part on any \<char>
3486 * A -1 return means no valid number was found,
3487 * the caller should use the appropriate default for this redirection.
3489 static int redirect_opt_num(o_string *o)
3493 if (o->data == NULL)
3495 num = bb_strtou(o->data, NULL, 10);
3496 if (errno || num < 0)
3498 o_reset_to_empty_unquoted(o);
3503 #define fetch_till_str(as_string, input, word, skip_tabs) \
3504 fetch_till_str(input, word, skip_tabs)
3506 static char *fetch_till_str(o_string *as_string,
3507 struct in_str *input,
3511 o_string heredoc = NULL_O_STRING;
3513 int prev = 0; /* not \ */
3519 ch = i_getch(input);
3521 nommu_addchr(as_string, ch);
3522 if ((ch == '\n' || ch == EOF)
3523 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3525 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3526 heredoc.data[past_EOL] = '\0';
3527 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3528 return heredoc.data;
3530 while (ch == '\n') {
3531 o_addchr(&heredoc, ch);
3534 past_EOL = heredoc.length;
3536 ch = i_getch(input);
3538 nommu_addchr(as_string, ch);
3539 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3543 o_free_unsafe(&heredoc);
3546 o_addchr(&heredoc, ch);
3547 nommu_addchr(as_string, ch);
3548 if (prev == '\\' && ch == '\\')
3549 /* Correctly handle foo\\<eol> (not a line cont.) */
3550 prev = 0; /* not \ */
3556 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3557 * and load them all. There should be exactly heredoc_cnt of them.
3559 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3561 struct pipe *pi = ctx->list_head;
3563 while (pi && heredoc_cnt) {
3565 struct command *cmd = pi->cmds;
3567 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3569 cmd->argv ? cmd->argv[0] : "NONE");
3570 for (i = 0; i < pi->num_cmds; i++) {
3571 struct redir_struct *redir = cmd->redirects;
3573 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3574 i, cmd->argv ? cmd->argv[0] : "NONE");
3576 if (redir->rd_type == REDIRECT_HEREDOC) {
3579 redir->rd_type = REDIRECT_HEREDOC2;
3580 /* redir->rd_dup is (ab)used to indicate <<- */
3581 p = fetch_till_str(&ctx->as_string, input,
3582 redir->rd_filename, redir->rd_dup);
3584 syntax_error("unexpected EOF in here document");
3587 free(redir->rd_filename);
3588 redir->rd_filename = p;
3591 redir = redir->next;
3598 /* Should be 0. If it isn't, it's a parse error */
3600 bb_error_msg_and_die("heredoc BUG 2");
3606 static int run_list(struct pipe *pi);
3608 #define parse_stream(pstring, input, end_trigger) \
3609 parse_stream(input, end_trigger)
3611 static struct pipe *parse_stream(char **pstring,
3612 struct in_str *input,
3616 #if !ENABLE_HUSH_FUNCTIONS
3617 #define parse_group(dest, ctx, input, ch) \
3618 parse_group(ctx, input, ch)
3620 static int parse_group(o_string *dest, struct parse_context *ctx,
3621 struct in_str *input, int ch)
3623 /* dest contains characters seen prior to ( or {.
3624 * Typically it's empty, but for function defs,
3625 * it contains function name (without '()'). */
3626 struct pipe *pipe_list;
3628 struct command *command = ctx->command;
3630 debug_printf_parse("parse_group entered\n");
3631 #if ENABLE_HUSH_FUNCTIONS
3632 if (ch == '(' && !dest->has_quoted_part) {
3634 if (done_word(dest, ctx))
3637 goto skip; /* (... */
3638 if (command->argv[1]) { /* word word ... (... */
3639 syntax_error_unexpected_ch('(');
3642 /* it is "word(..." or "word (..." */
3644 ch = i_getch(input);
3645 while (ch == ' ' || ch == '\t');
3647 syntax_error_unexpected_ch(ch);
3650 nommu_addchr(&ctx->as_string, ch);
3652 ch = i_getch(input);
3653 while (ch == ' ' || ch == '\t' || ch == '\n');
3655 syntax_error_unexpected_ch(ch);
3658 nommu_addchr(&ctx->as_string, ch);
3659 command->cmd_type = CMD_FUNCDEF;
3664 #if 0 /* Prevented by caller */
3665 if (command->argv /* word [word]{... */
3666 || dest->length /* word{... */
3667 || dest->has_quoted_part /* ""{... */
3670 debug_printf_parse("parse_group return 1: "
3671 "syntax error, groups and arglists don't mix\n");
3676 #if ENABLE_HUSH_FUNCTIONS
3682 command->cmd_type = CMD_SUBSHELL;
3684 /* bash does not allow "{echo...", requires whitespace */
3685 ch = i_getch(input);
3686 if (ch != ' ' && ch != '\t' && ch != '\n') {
3687 syntax_error_unexpected_ch(ch);
3690 nommu_addchr(&ctx->as_string, ch);
3695 # define as_string NULL
3697 char *as_string = NULL;
3699 pipe_list = parse_stream(&as_string, input, endch);
3702 o_addstr(&ctx->as_string, as_string);
3704 /* empty ()/{} or parse error? */
3705 if (!pipe_list || pipe_list == ERR_PTR) {
3706 /* parse_stream already emitted error msg */
3709 debug_printf_parse("parse_group return 1: "
3710 "parse_stream returned %p\n", pipe_list);
3713 command->group = pipe_list;
3715 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3716 command->group_as_string = as_string;
3717 debug_printf_parse("end of group, remembering as:'%s'\n",
3718 command->group_as_string);
3722 debug_printf_parse("parse_group return 0\n");
3724 /* command remains "open", available for possible redirects */
3727 #if ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS
3728 /* Subroutines for copying $(...) and `...` things */
3729 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
3731 static int add_till_single_quote(o_string *dest, struct in_str *input)
3734 int ch = i_getch(input);
3736 syntax_error_unterm_ch('\'');
3744 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
3745 static int add_till_double_quote(o_string *dest, struct in_str *input)
3748 int ch = i_getch(input);
3750 syntax_error_unterm_ch('"');
3755 if (ch == '\\') { /* \x. Copy both chars. */
3757 ch = i_getch(input);
3761 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
3766 //if (ch == '$') ...
3769 /* Process `cmd` - copy contents until "`" is seen. Complicated by
3771 * "Within the backquoted style of command substitution, backslash
3772 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
3773 * The search for the matching backquote shall be satisfied by the first
3774 * backquote found without a preceding backslash; during this search,
3775 * if a non-escaped backquote is encountered within a shell comment,
3776 * a here-document, an embedded command substitution of the $(command)
3777 * form, or a quoted string, undefined results occur. A single-quoted
3778 * or double-quoted string that begins, but does not end, within the
3779 * "`...`" sequence produces undefined results."
3781 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
3783 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
3786 int ch = i_getch(input);
3790 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
3791 ch = i_getch(input);
3795 && (!in_dquote || ch != '"')
3797 o_addchr(dest, '\\');
3801 syntax_error_unterm_ch('`');
3807 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
3808 * quoting and nested ()s.
3809 * "With the $(command) style of command substitution, all characters
3810 * following the open parenthesis to the matching closing parenthesis
3811 * constitute the command. Any valid shell script can be used for command,
3812 * except a script consisting solely of redirections which produces
3813 * unspecified results."
3815 * echo $(echo '(TEST)' BEST) (TEST) BEST
3816 * echo $(echo 'TEST)' BEST) TEST) BEST
3817 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
3819 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
3820 * can contain arbitrary constructs, just like $(cmd).
3821 * In bash compat mode, it needs to also be able to stop on ':' or '/'
3822 * for ${var:N[:M]} and ${var/P[/R]} parsing.
3824 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
3825 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
3828 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
3829 # if ENABLE_HUSH_BASH_COMPAT
3830 char end_char2 = end_ch >> 8;
3832 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
3835 ch = i_getch(input);
3837 syntax_error_unterm_ch(end_ch);
3840 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
3843 /* we look for closing )) of $((EXPR)) */
3844 if (i_peek(input) == end_ch) {
3845 i_getch(input); /* eat second ')' */
3850 if (ch == '(' || ch == '{') {
3851 ch = (ch == '(' ? ')' : '}');
3852 if (!add_till_closing_bracket(dest, input, ch))
3858 if (!add_till_single_quote(dest, input))
3864 if (!add_till_double_quote(dest, input))
3870 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
3876 /* \x. Copy verbatim. Important for \(, \) */
3877 ch = i_getch(input);
3879 syntax_error_unterm_ch(')');
3888 #endif /* ENABLE_HUSH_TICK || ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_DOLLAR_OPS */
3890 /* Return code: 0 for OK, 1 for syntax error */
3892 #define parse_dollar(as_string, dest, input, quote_mask) \
3893 parse_dollar(dest, input, quote_mask)
3894 #define as_string NULL
3896 static int parse_dollar(o_string *as_string,
3898 struct in_str *input, unsigned char quote_mask)
3900 int ch = i_peek(input); /* first character after the $ */
3902 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
3904 ch = i_getch(input);
3905 nommu_addchr(as_string, ch);
3907 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3909 debug_printf_parse(": '%c'\n", ch);
3910 o_addchr(dest, ch | quote_mask);
3913 if (!isalnum(ch) && ch != '_')
3915 ch = i_getch(input);
3916 nommu_addchr(as_string, ch);
3918 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3919 } else if (isdigit(ch)) {
3921 ch = i_getch(input);
3922 nommu_addchr(as_string, ch);
3923 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3924 debug_printf_parse(": '%c'\n", ch);
3925 o_addchr(dest, ch | quote_mask);
3926 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3927 } else switch (ch) {
3929 case '!': /* last bg pid */
3930 case '?': /* last exit code */
3931 case '#': /* number of args */
3932 case '*': /* args */
3933 case '@': /* args */
3934 goto make_one_char_var;
3936 o_addchr(dest, SPECIAL_VAR_SYMBOL);
3938 ch = i_getch(input); /* eat '{' */
3939 nommu_addchr(as_string, ch);
3941 ch = i_getch(input); /* first char after '{' */
3942 /* It should be ${?}, or ${#var},
3943 * or even ${?+subst} - operator acting on a special variable,
3944 * or the beginning of variable name.
3947 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
3950 syntax_error_unterm_str("${name}");
3951 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
3954 nommu_addchr(as_string, ch);
3957 /* It's possible to just call add_till_closing_bracket() at this point.
3958 * However, this regresses some of our testsuite cases
3959 * which check invalid constructs like ${%}.
3960 * Oh well... let's check that the var name part is fine... */
3966 debug_printf_parse(": '%c'\n", ch);
3968 ch = i_getch(input);
3969 nommu_addchr(as_string, ch);
3973 if (!isalnum(ch) && ch != '_') {
3975 unsigned char last_ch;
3976 /* handle parameter expansions
3977 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
3979 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
3980 goto bad_dollar_syntax;
3982 /* Eat everything until closing '}' (or ':') */
3984 if (ENABLE_HUSH_BASH_COMPAT
3986 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
3988 /* It's ${var:N[:M]} thing */
3989 end_ch = '}' * 0x100 + ':';
3991 if (ENABLE_HUSH_BASH_COMPAT
3994 /* It's ${var/[/]pattern[/repl]} thing */
3995 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
3997 nommu_addchr(as_string, '/');
4000 end_ch = '}' * 0x100 + '/';
4006 #if ENABLE_HUSH_DOLLAR_OPS
4007 last_ch = add_till_closing_bracket(dest, input, end_ch);
4008 if (last_ch == 0) /* error? */
4011 #error Simple code to only allow ${var} is not implemented
4014 o_addstr(as_string, dest->data + pos);
4015 o_addchr(as_string, last_ch);
4018 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4019 /* close the first block: */
4020 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4021 /* while parsing N from ${var:N[:M]}
4022 * or pattern from ${var/[/]pattern[/repl]} */
4023 if ((end_ch & 0xff) == last_ch) {
4024 /* got ':' or '/'- parse the rest */
4029 if (end_ch == '}' * 0x100 + ':') {
4030 /* it's ${var:N} - emulate :999999999 */
4031 o_addstr(dest, "999999999");
4032 } /* else: it's ${var/[/]pattern} */
4037 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4040 #if ENABLE_SH_MATH_SUPPORT || ENABLE_HUSH_TICK
4044 ch = i_getch(input);
4045 nommu_addchr(as_string, ch);
4046 # if ENABLE_SH_MATH_SUPPORT
4047 if (i_peek(input) == '(') {
4048 ch = i_getch(input);
4049 nommu_addchr(as_string, ch);
4050 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4051 o_addchr(dest, /*quote_mask |*/ '+');
4054 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4055 return 0; /* error */
4057 o_addstr(as_string, dest->data + pos);
4058 o_addchr(as_string, ')');
4059 o_addchr(as_string, ')');
4061 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4065 # if ENABLE_HUSH_TICK
4066 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4067 o_addchr(dest, quote_mask | '`');
4070 if (!add_till_closing_bracket(dest, input, ')'))
4071 return 0; /* error */
4073 o_addstr(as_string, dest->data + pos);
4074 o_addchr(as_string, ')');
4076 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4082 ch = i_getch(input);
4083 nommu_addchr(as_string, ch);
4085 if (isalnum(ch)) { /* it's $_name or $_123 */
4090 /* TODO: $_ and $-: */
4091 /* $_ Shell or shell script name; or last argument of last command
4092 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4093 * but in command's env, set to full pathname used to invoke it */
4094 /* $- Option flags set by set builtin or shell options (-i etc) */
4096 o_addQchr(dest, '$');
4098 debug_printf_parse("parse_dollar return 1 (ok)\n");
4104 # if ENABLE_HUSH_BASH_COMPAT
4105 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4106 encode_string(dest, input, dquote_end, process_bkslash)
4108 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4109 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4110 encode_string(dest, input, dquote_end)
4112 #define as_string NULL
4116 # if ENABLE_HUSH_BASH_COMPAT
4117 /* all parameters are needed, no macro tricks */
4119 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4120 encode_string(as_string, dest, input, dquote_end)
4123 static int encode_string(o_string *as_string,
4125 struct in_str *input,
4127 int process_bkslash)
4129 #if !ENABLE_HUSH_BASH_COMPAT
4130 const int process_bkslash = 1;
4136 ch = i_getch(input);
4138 nommu_addchr(as_string, ch);
4139 if (ch == dquote_end) { /* may be only '"' or EOF */
4140 debug_printf_parse("encode_string return 1 (ok)\n");
4143 /* note: can't move it above ch == dquote_end check! */
4145 syntax_error_unterm_ch('"');
4146 return 0; /* error */
4150 next = i_peek(input);
4152 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4153 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4154 if (process_bkslash && ch == '\\') {
4156 syntax_error("\\<eof>");
4160 * "The backslash retains its special meaning [in "..."]
4161 * only when followed by one of the following characters:
4162 * $, `, ", \, or <newline>. A double quote may be quoted
4163 * within double quotes by preceding it with a backslash."
4164 * NB: in (unquoted) heredoc, above does not apply to ",
4165 * therefore we check for it by "next == dquote_end" cond.
4167 if (next == dquote_end || strchr("$`\\\n", next)) {
4168 ch = i_getch(input); /* eat next */
4170 goto again; /* skip \<newline> */
4171 } /* else: ch remains == '\\', and we double it below: */
4172 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4173 nommu_addchr(as_string, ch);
4177 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4178 debug_printf_parse("encode_string return 0: "
4179 "parse_dollar returned 0 (error)\n");
4184 #if ENABLE_HUSH_TICK
4186 //unsigned pos = dest->length;
4187 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4188 o_addchr(dest, 0x80 | '`');
4189 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4190 return 0; /* error */
4191 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4192 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4196 o_addQchr(dest, ch);
4202 * Scan input until EOF or end_trigger char.
4203 * Return a list of pipes to execute, or NULL on EOF
4204 * or if end_trigger character is met.
4205 * On syntax error, exit if shell is not interactive,
4206 * reset parsing machinery and start parsing anew,
4207 * or return ERR_PTR.
4209 static struct pipe *parse_stream(char **pstring,
4210 struct in_str *input,
4213 struct parse_context ctx;
4214 o_string dest = NULL_O_STRING;
4217 /* Single-quote triggers a bypass of the main loop until its mate is
4218 * found. When recursing, quote state is passed in via dest->o_expflags.
4220 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4221 end_trigger ? end_trigger : 'X');
4224 /* If very first arg is "" or '', dest.data may end up NULL.
4225 * Preventing this: */
4226 o_addchr(&dest, '\0');
4229 /* We used to separate words on $IFS here. This was wrong.
4230 * $IFS is used only for word splitting when $var is expanded,
4231 * here we should use blank chars as separators, not $IFS
4234 if (MAYBE_ASSIGNMENT != 0)
4235 dest.o_assignment = MAYBE_ASSIGNMENT;
4236 initialize_context(&ctx);
4239 const char *is_blank;
4240 const char *is_special;
4244 redir_type redir_style;
4246 ch = i_getch(input);
4247 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4248 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4253 syntax_error_unterm_str("here document");
4256 /* end_trigger == '}' case errors out earlier,
4257 * checking only ')' */
4258 if (end_trigger == ')') {
4259 syntax_error_unterm_ch('(');
4263 if (done_word(&dest, &ctx)) {
4267 done_pipe(&ctx, PIPE_SEQ);
4269 /* If we got nothing... */
4270 /* (this makes bare "&" cmd a no-op.
4271 * bash says: "syntax error near unexpected token '&'") */
4272 if (pi->num_cmds == 0
4273 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4279 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4281 *pstring = ctx.as_string.data;
4283 o_free_unsafe(&ctx.as_string);
4286 debug_printf_parse("parse_stream return %p\n", pi);
4289 nommu_addchr(&ctx.as_string, ch);
4293 next = i_peek(input);
4295 is_special = "{}<>;&|()#'" /* special outside of "str" */
4296 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4297 /* Are { and } special here? */
4298 if (ctx.command->argv /* word [word]{... - non-special */
4299 || dest.length /* word{... - non-special */
4300 || dest.has_quoted_part /* ""{... - non-special */
4301 || (next != ';' /* }; - special */
4302 && next != ')' /* }) - special */
4303 && next != '&' /* }& and }&& ... - special */
4304 && next != '|' /* }|| ... - special */
4305 && !strchr(defifs, next) /* {word - non-special */
4308 /* They are not special, skip "{}" */
4311 is_special = strchr(is_special, ch);
4312 is_blank = strchr(defifs, ch);
4314 if (!is_special && !is_blank) { /* ordinary char */
4316 o_addQchr(&dest, ch);
4317 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4318 || dest.o_assignment == WORD_IS_KEYWORD)
4320 && is_well_formed_var_name(dest.data, '=')
4322 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4323 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4329 if (done_word(&dest, &ctx)) {
4333 /* Is this a case when newline is simply ignored?
4335 * "cmd | <newline> cmd ..."
4336 * "case ... in <newline> word) ..."
4338 if (IS_NULL_CMD(ctx.command)
4339 && dest.length == 0 && !dest.has_quoted_part
4341 /* This newline can be ignored. But...
4342 * Without check #1, interactive shell
4343 * ignores even bare <newline>,
4344 * and shows the continuation prompt:
4345 * ps1_prompt$ <enter>
4346 * ps2> _ <=== wrong, should be ps1
4347 * Without check #2, "cmd & <newline>"
4348 * is similarly mistreated.
4349 * (BTW, this makes "cmd & cmd"
4350 * and "cmd && cmd" non-orthogonal.
4351 * Really, ask yourself, why
4352 * "cmd && <newline>" doesn't start
4353 * cmd but waits for more input?
4356 struct pipe *pi = ctx.list_head;
4357 if (pi->num_cmds != 0 /* check #1 */
4358 && pi->followup != PIPE_BG /* check #2 */
4363 /* Treat newline as a command separator. */
4364 done_pipe(&ctx, PIPE_SEQ);
4365 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4367 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4372 dest.o_assignment = MAYBE_ASSIGNMENT;
4373 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4375 /* note: if (is_blank) continue;
4376 * will still trigger for us */
4380 /* "cmd}" or "cmd }..." without semicolon or &:
4381 * } is an ordinary char in this case, even inside { cmd; }
4382 * Pathological example: { ""}; } should exec "}" cmd
4385 if (!IS_NULL_CMD(ctx.command) /* cmd } */
4386 || dest.length != 0 /* word} */
4387 || dest.has_quoted_part /* ""} */
4391 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4392 goto skip_end_trigger;
4393 /* else: } does terminate a group */
4396 if (end_trigger && end_trigger == ch
4397 && (ch != ';' || heredoc_cnt == 0)
4398 #if ENABLE_HUSH_CASE
4400 || ctx.ctx_res_w != RES_MATCH
4401 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4406 /* This is technically valid:
4407 * { cat <<HERE; }; echo Ok
4411 * but we don't support this.
4412 * We require heredoc to be in enclosing {}/(),
4415 syntax_error_unterm_str("here document");
4418 if (done_word(&dest, &ctx)) {
4421 done_pipe(&ctx, PIPE_SEQ);
4422 dest.o_assignment = MAYBE_ASSIGNMENT;
4423 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4424 /* Do we sit outside of any if's, loops or case's? */
4426 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4430 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4432 *pstring = ctx.as_string.data;
4434 o_free_unsafe(&ctx.as_string);
4437 debug_printf_parse("parse_stream return %p: "
4438 "end_trigger char found\n",
4440 return ctx.list_head;
4447 /* Catch <, > before deciding whether this word is
4448 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4451 redir_fd = redirect_opt_num(&dest);
4452 if (done_word(&dest, &ctx)) {
4455 redir_style = REDIRECT_OVERWRITE;
4457 redir_style = REDIRECT_APPEND;
4458 ch = i_getch(input);
4459 nommu_addchr(&ctx.as_string, ch);
4462 else if (next == '(') {
4463 syntax_error(">(process) not supported");
4467 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4469 continue; /* back to top of while (1) */
4471 redir_fd = redirect_opt_num(&dest);
4472 if (done_word(&dest, &ctx)) {
4475 redir_style = REDIRECT_INPUT;
4477 redir_style = REDIRECT_HEREDOC;
4479 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4480 ch = i_getch(input);
4481 nommu_addchr(&ctx.as_string, ch);
4482 } else if (next == '>') {
4483 redir_style = REDIRECT_IO;
4484 ch = i_getch(input);
4485 nommu_addchr(&ctx.as_string, ch);
4488 else if (next == '(') {
4489 syntax_error("<(process) not supported");
4493 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4495 continue; /* back to top of while (1) */
4497 if (dest.length == 0 && !dest.has_quoted_part) {
4498 /* skip "#comment" */
4501 if (ch == EOF || ch == '\n')
4504 /* note: we do not add it to &ctx.as_string */
4506 nommu_addchr(&ctx.as_string, '\n');
4507 continue; /* back to top of while (1) */
4512 /* It's "\<newline>" */
4514 /* Remove trailing '\' from ctx.as_string */
4515 ctx.as_string.data[--ctx.as_string.length] = '\0';
4517 ch = i_getch(input); /* eat it */
4518 continue; /* back to top of while (1) */
4523 if (dest.o_assignment == MAYBE_ASSIGNMENT
4524 /* check that we are not in word in "a=1 2>word b=1": */
4525 && !ctx.pending_redirect
4527 /* ch is a special char and thus this word
4528 * cannot be an assignment */
4529 dest.o_assignment = NOT_ASSIGNMENT;
4530 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4533 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4536 case '#': /* non-comment #: "echo a#b" etc */
4537 o_addQchr(&dest, ch);
4541 syntax_error("\\<eof>");
4544 ch = i_getch(input);
4545 /* note: ch != '\n' (that case does not reach this place) */
4546 o_addchr(&dest, '\\');
4547 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4548 o_addchr(&dest, ch);
4549 nommu_addchr(&ctx.as_string, ch);
4550 /* Example: echo Hello \2>file
4551 * we need to know that word 2 is quoted */
4552 dest.has_quoted_part = 1;
4555 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4556 debug_printf_parse("parse_stream parse error: "
4557 "parse_dollar returned 0 (error)\n");
4562 dest.has_quoted_part = 1;
4563 if (next == '\'' && !ctx.pending_redirect) {
4564 insert_empty_quoted_str_marker:
4565 nommu_addchr(&ctx.as_string, next);
4566 i_getch(input); /* eat second ' */
4567 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4568 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4571 ch = i_getch(input);
4573 syntax_error_unterm_ch('\'');
4576 nommu_addchr(&ctx.as_string, ch);
4579 o_addqchr(&dest, ch);
4584 dest.has_quoted_part = 1;
4585 if (next == '"' && !ctx.pending_redirect)
4586 goto insert_empty_quoted_str_marker;
4587 if (dest.o_assignment == NOT_ASSIGNMENT)
4588 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4589 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4591 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4593 #if ENABLE_HUSH_TICK
4595 USE_FOR_NOMMU(unsigned pos;)
4597 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4598 o_addchr(&dest, '`');
4599 USE_FOR_NOMMU(pos = dest.length;)
4600 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4603 o_addstr(&ctx.as_string, dest.data + pos);
4604 o_addchr(&ctx.as_string, '`');
4606 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4607 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4612 #if ENABLE_HUSH_CASE
4615 if (done_word(&dest, &ctx)) {
4618 done_pipe(&ctx, PIPE_SEQ);
4619 #if ENABLE_HUSH_CASE
4620 /* Eat multiple semicolons, detect
4621 * whether it means something special */
4626 ch = i_getch(input);
4627 nommu_addchr(&ctx.as_string, ch);
4628 if (ctx.ctx_res_w == RES_CASE_BODY) {
4629 ctx.ctx_dsemicolon = 1;
4630 ctx.ctx_res_w = RES_MATCH;
4636 /* We just finished a cmd. New one may start
4637 * with an assignment */
4638 dest.o_assignment = MAYBE_ASSIGNMENT;
4639 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4642 if (done_word(&dest, &ctx)) {
4646 ch = i_getch(input);
4647 nommu_addchr(&ctx.as_string, ch);
4648 done_pipe(&ctx, PIPE_AND);
4650 done_pipe(&ctx, PIPE_BG);
4654 if (done_word(&dest, &ctx)) {
4657 #if ENABLE_HUSH_CASE
4658 if (ctx.ctx_res_w == RES_MATCH)
4659 break; /* we are in case's "word | word)" */
4661 if (next == '|') { /* || */
4662 ch = i_getch(input);
4663 nommu_addchr(&ctx.as_string, ch);
4664 done_pipe(&ctx, PIPE_OR);
4666 /* we could pick up a file descriptor choice here
4667 * with redirect_opt_num(), but bash doesn't do it.
4668 * "echo foo 2| cat" yields "foo 2". */
4673 #if ENABLE_HUSH_CASE
4674 /* "case... in [(]word)..." - skip '(' */
4675 if (ctx.ctx_res_w == RES_MATCH
4676 && ctx.command->argv == NULL /* not (word|(... */
4677 && dest.length == 0 /* not word(... */
4678 && dest.has_quoted_part == 0 /* not ""(... */
4684 if (parse_group(&dest, &ctx, input, ch) != 0) {
4689 #if ENABLE_HUSH_CASE
4690 if (ctx.ctx_res_w == RES_MATCH)
4694 /* proper use of this character is caught by end_trigger:
4695 * if we see {, we call parse_group(..., end_trigger='}')
4696 * and it will match } earlier (not here). */
4697 syntax_error_unexpected_ch(ch);
4701 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
4707 struct parse_context *pctx;
4708 IF_HAS_KEYWORDS(struct parse_context *p2;)
4710 /* Clean up allocated tree.
4711 * Sample for finding leaks on syntax error recovery path.
4712 * Run it from interactive shell, watch pmap `pidof hush`.
4713 * while if false; then false; fi; do break; fi
4714 * Samples to catch leaks at execution:
4715 * while if (true | {true;}); then echo ok; fi; do break; done
4716 * while if (true | {true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
4720 /* Update pipe/command counts,
4721 * otherwise freeing may miss some */
4722 done_pipe(pctx, PIPE_SEQ);
4723 debug_printf_clean("freeing list %p from ctx %p\n",
4724 pctx->list_head, pctx);
4725 debug_print_tree(pctx->list_head, 0);
4726 free_pipe_list(pctx->list_head);
4727 debug_printf_clean("freed list %p\n", pctx->list_head);
4729 o_free_unsafe(&pctx->as_string);
4731 IF_HAS_KEYWORDS(p2 = pctx->stack;)
4735 IF_HAS_KEYWORDS(pctx = p2;)
4736 } while (HAS_KEYWORDS && pctx);
4739 G.last_exitcode = 1;
4750 /*** Execution routines ***/
4752 /* Expansion can recurse, need forward decls: */
4753 #if !ENABLE_HUSH_BASH_COMPAT
4754 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4755 #define expand_string_to_string(str, do_unbackslash) \
4756 expand_string_to_string(str)
4758 static char *expand_string_to_string(const char *str, int do_unbackslash);
4759 #if ENABLE_HUSH_TICK
4760 static int process_command_subs(o_string *dest, const char *s);
4763 /* expand_strvec_to_strvec() takes a list of strings, expands
4764 * all variable references within and returns a pointer to
4765 * a list of expanded strings, possibly with larger number
4766 * of strings. (Think VAR="a b"; echo $VAR).
4767 * This new list is allocated as a single malloc block.
4768 * NULL-terminated list of char* pointers is at the beginning of it,
4769 * followed by strings themselves.
4770 * Caller can deallocate entire list by single free(list). */
4772 /* A horde of its helpers come first: */
4774 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
4776 while (--len >= 0) {
4779 #if ENABLE_HUSH_BRACE_EXPANSION
4780 if (c == '{' || c == '}') {
4781 /* { -> \{, } -> \} */
4783 /* And now we want to add { or } and continue:
4786 * luckily, just falling throught achieves this.
4792 /* \z -> \\\z; \<eol> -> \\<eol> */
4797 o_addchr(o, *str++);
4803 /* Store given string, finalizing the word and starting new one whenever
4804 * we encounter IFS char(s). This is used for expanding variable values.
4805 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
4806 * Return in *ended_with_ifs:
4807 * 1 - ended with IFS char, else 0 (this includes case of empty str).
4809 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
4811 int last_is_ifs = 0;
4816 if (!*str) /* EOL - do not finalize word */
4818 word_len = strcspn(str, G.ifs);
4820 /* We have WORD_LEN leading non-IFS chars */
4821 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
4822 o_addblock(output, str, word_len);
4824 /* Protect backslashes against globbing up :)
4825 * Example: "v='\*'; echo b$v" prints "b\*"
4826 * (and does not try to glob on "*")
4828 o_addblock_duplicate_backslash(output, str, word_len);
4829 /*/ Why can't we do it easier? */
4830 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
4831 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
4835 if (!*str) /* EOL - do not finalize word */
4839 /* We know str here points to at least one IFS char */
4841 str += strspn(str, G.ifs); /* skip IFS chars */
4842 if (!*str) /* EOL - do not finalize word */
4845 /* Start new word... but not always! */
4846 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
4847 if (output->has_quoted_part
4848 /* Case "v=' a'; echo $v":
4849 * here nothing precedes the space in $v expansion,
4850 * therefore we should not finish the word
4851 * (IOW: if there *is* word to finalize, only then do it):
4853 || (n > 0 && output->data[output->length - 1])
4855 o_addchr(output, '\0');
4856 debug_print_list("expand_on_ifs", output, n);
4857 n = o_save_ptr(output, n);
4862 *ended_with_ifs = last_is_ifs;
4863 debug_print_list("expand_on_ifs[1]", output, n);
4867 /* Helper to expand $((...)) and heredoc body. These act as if
4868 * they are in double quotes, with the exception that they are not :).
4869 * Just the rules are similar: "expand only $var and `cmd`"
4871 * Returns malloced string.
4872 * As an optimization, we return NULL if expansion is not needed.
4874 #if !ENABLE_HUSH_BASH_COMPAT
4875 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4876 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
4877 encode_then_expand_string(str)
4879 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
4882 struct in_str input;
4883 o_string dest = NULL_O_STRING;
4885 if (!strchr(str, '$')
4886 && !strchr(str, '\\')
4887 #if ENABLE_HUSH_TICK
4888 && !strchr(str, '`')
4894 /* We need to expand. Example:
4895 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
4897 setup_string_in_str(&input, str);
4898 encode_string(NULL, &dest, &input, EOF, process_bkslash);
4899 //TODO: error check (encode_string returns 0 on error)?
4900 //bb_error_msg("'%s' -> '%s'", str, dest.data);
4901 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
4902 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
4903 o_free_unsafe(&dest);
4907 #if ENABLE_SH_MATH_SUPPORT
4908 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
4910 arith_state_t math_state;
4914 math_state.lookupvar = get_local_var_value;
4915 math_state.setvar = set_local_var_from_halves;
4916 //math_state.endofname = endofname;
4917 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
4918 res = arith(&math_state, exp_str ? exp_str : arg);
4921 *errmsg_p = math_state.errmsg;
4922 if (math_state.errmsg)
4923 die_if_script(math_state.errmsg);
4928 #if ENABLE_HUSH_BASH_COMPAT
4929 /* ${var/[/]pattern[/repl]} helpers */
4930 static char *strstr_pattern(char *val, const char *pattern, int *size)
4933 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
4934 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
4941 /* Optimization: if "*pat" did not match the start of "string",
4942 * we know that "tring", "ring" etc will not match too:
4944 if (pattern[0] == '*')
4949 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
4951 char *result = NULL;
4952 unsigned res_len = 0;
4953 unsigned repl_len = strlen(repl);
4957 char *s = strstr_pattern(val, pattern, &size);
4961 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
4962 memcpy(result + res_len, val, s - val);
4964 strcpy(result + res_len, repl);
4965 res_len += repl_len;
4966 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
4972 if (val[0] && result) {
4973 result = xrealloc(result, res_len + strlen(val) + 1);
4974 strcpy(result + res_len, val);
4975 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
4977 debug_printf_varexp("result:'%s'\n", result);
4983 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
4985 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
4987 const char *val = NULL;
4988 char *to_be_freed = NULL;
4993 char exp_save = exp_save; /* for compiler */
4994 char *exp_saveptr; /* points to expansion operator */
4995 char *exp_word = exp_word; /* for compiler */
4998 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5000 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5002 first_char = arg[0] = arg0 & 0x7f;
5005 if (first_char == '#' /* ${#... */
5006 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5008 /* It must be length operator: ${#var} */
5012 /* Maybe handle parameter expansion */
5013 if (exp_saveptr /* if 2nd char is one of expansion operators */
5014 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5016 /* ${?:0}, ${#[:]%0} etc */
5017 exp_saveptr = var + 1;
5019 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5020 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5022 exp_op = exp_save = *exp_saveptr;
5024 exp_word = exp_saveptr + 1;
5025 if (exp_op == ':') {
5026 exp_op = *exp_word++;
5027 //TODO: try ${var:} and ${var:bogus} in non-bash config
5028 if (ENABLE_HUSH_BASH_COMPAT
5029 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5031 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5036 *exp_saveptr = '\0';
5037 } /* else: it's not an expansion op, but bare ${var} */
5040 /* Look up the variable in question */
5041 if (isdigit(var[0])) {
5042 /* parse_dollar should have vetted var for us */
5043 int n = xatoi_positive(var);
5044 if (n < G.global_argc)
5045 val = G.global_argv[n];
5046 /* else val remains NULL: $N with too big N */
5050 val = utoa(G.root_pid);
5052 case '!': /* bg pid */
5053 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5055 case '?': /* exitcode */
5056 val = utoa(G.last_exitcode);
5058 case '#': /* argc */
5059 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5062 val = get_local_var_value(var);
5066 /* Handle any expansions */
5067 if (exp_op == 'L') {
5068 reinit_unicode_for_hush();
5069 debug_printf_expand("expand: length(%s)=", val);
5070 val = utoa(val ? unicode_strlen(val) : 0);
5071 debug_printf_expand("%s\n", val);
5072 } else if (exp_op) {
5073 if (exp_op == '%' || exp_op == '#') {
5074 /* Standard-mandated substring removal ops:
5075 * ${parameter%word} - remove smallest suffix pattern
5076 * ${parameter%%word} - remove largest suffix pattern
5077 * ${parameter#word} - remove smallest prefix pattern
5078 * ${parameter##word} - remove largest prefix pattern
5080 * Word is expanded to produce a glob pattern.
5081 * Then var's value is matched to it and matching part removed.
5083 if (val && val[0]) {
5087 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5088 if (exp_op == *exp_word) /* ## or %% */
5090 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5092 exp_word = exp_exp_word;
5093 /* HACK ALERT. We depend here on the fact that
5094 * G.global_argv and results of utoa and get_local_var_value
5095 * are actually in writable memory:
5096 * scan_and_match momentarily stores NULs there. */
5098 loc = scan_and_match(t, exp_word, scan_flags);
5099 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5100 // exp_op, t, exp_word, loc);
5102 if (loc) { /* match was found */
5103 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5104 val = loc; /* take right part */
5106 val = to_be_freed = xstrndup(val, loc - val); /* left */
5110 #if ENABLE_HUSH_BASH_COMPAT
5111 else if (exp_op == '/' || exp_op == '\\') {
5112 /* It's ${var/[/]pattern[/repl]} thing.
5113 * Note that in encoded form it has TWO parts:
5114 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5115 * and if // is used, it is encoded as \:
5116 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5118 /* Empty variable always gives nothing: */
5119 // "v=''; echo ${v/*/w}" prints "", not "w"
5120 if (val && val[0]) {
5121 /* pattern uses non-standard expansion.
5122 * repl should be unbackslashed and globbed
5123 * by the usual expansion rules:
5125 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5126 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5127 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5128 * v='a bz'; echo ${v/a*z/\z} prints "z"
5129 * (note that a*z _pattern_ is never globbed!)
5131 char *pattern, *repl, *t;
5132 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5134 pattern = xstrdup(exp_word);
5135 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5136 *p++ = SPECIAL_VAR_SYMBOL;
5138 p = strchr(p, SPECIAL_VAR_SYMBOL);
5140 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5141 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5142 /* HACK ALERT. We depend here on the fact that
5143 * G.global_argv and results of utoa and get_local_var_value
5144 * are actually in writable memory:
5145 * replace_pattern momentarily stores NULs there. */
5147 to_be_freed = replace_pattern(t,
5149 (repl ? repl : exp_word),
5151 if (to_be_freed) /* at least one replace happened */
5158 else if (exp_op == ':') {
5159 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_SH_MATH_SUPPORT
5160 /* It's ${var:N[:M]} bashism.
5161 * Note that in encoded form it has TWO parts:
5162 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5167 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5170 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5171 *p++ = SPECIAL_VAR_SYMBOL;
5173 p = strchr(p, SPECIAL_VAR_SYMBOL);
5175 len = expand_and_evaluate_arith(exp_word, &errmsg);
5178 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5179 if (len >= 0) { /* bash compat: len < 0 is illegal */
5180 if (beg < 0) /* bash compat */
5182 debug_printf_varexp("from val:'%s'\n", val);
5183 if (len == 0 || !val || beg >= strlen(val)) {
5187 /* Paranoia. What if user entered 9999999999999
5188 * which fits in arith_t but not int? */
5191 val = to_be_freed = xstrndup(val + beg, len);
5193 debug_printf_varexp("val:'%s'\n", val);
5197 die_if_script("malformed ${%s:...}", var);
5200 } else { /* one of "-=+?" */
5201 /* Standard-mandated substitution ops:
5202 * ${var?word} - indicate error if unset
5203 * If var is unset, word (or a message indicating it is unset
5204 * if word is null) is written to standard error
5205 * and the shell exits with a non-zero exit status.
5206 * Otherwise, the value of var is substituted.
5207 * ${var-word} - use default value
5208 * If var is unset, word is substituted.
5209 * ${var=word} - assign and use default value
5210 * If var is unset, word is assigned to var.
5211 * In all cases, final value of var is substituted.
5212 * ${var+word} - use alternative value
5213 * If var is unset, null is substituted.
5214 * Otherwise, word is substituted.
5216 * Word is subjected to tilde expansion, parameter expansion,
5217 * command substitution, and arithmetic expansion.
5218 * If word is not needed, it is not expanded.
5220 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5221 * but also treat null var as if it is unset.
5223 int use_word = (!val || ((exp_save == ':') && !val[0]));
5225 use_word = !use_word;
5226 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5227 (exp_save == ':') ? "true" : "false", use_word);
5229 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5231 exp_word = to_be_freed;
5232 if (exp_op == '?') {
5233 /* mimic bash message */
5234 die_if_script("%s: %s",
5236 exp_word[0] ? exp_word : "parameter null or not set"
5238 //TODO: how interactive bash aborts expansion mid-command?
5243 if (exp_op == '=') {
5244 /* ${var=[word]} or ${var:=[word]} */
5245 if (isdigit(var[0]) || var[0] == '#') {
5246 /* mimic bash message */
5247 die_if_script("$%s: cannot assign in this way", var);
5250 char *new_var = xasprintf("%s=%s", var, val);
5251 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5255 } /* one of "-=+?" */
5257 *exp_saveptr = exp_save;
5263 *to_be_freed_pp = to_be_freed;
5267 /* Expand all variable references in given string, adding words to list[]
5268 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5269 * to be filled). This routine is extremely tricky: has to deal with
5270 * variables/parameters with whitespace, $* and $@, and constructs like
5271 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5272 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5274 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5275 * expansion of right-hand side of assignment == 1-element expand.
5277 char cant_be_null = 0; /* only bit 0x80 matters */
5278 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5281 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5282 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5283 debug_print_list("expand_vars_to_list", output, n);
5284 n = o_save_ptr(output, n);
5285 debug_print_list("expand_vars_to_list[0]", output, n);
5287 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5289 char *to_be_freed = NULL;
5290 const char *val = NULL;
5291 #if ENABLE_HUSH_TICK
5292 o_string subst_result = NULL_O_STRING;
5294 #if ENABLE_SH_MATH_SUPPORT
5295 char arith_buf[sizeof(arith_t)*3 + 2];
5299 o_addchr(output, '\0');
5300 n = o_save_ptr(output, n);
5304 o_addblock(output, arg, p - arg);
5305 debug_print_list("expand_vars_to_list[1]", output, n);
5307 p = strchr(p, SPECIAL_VAR_SYMBOL);
5309 /* Fetch special var name (if it is indeed one of them)
5310 * and quote bit, force the bit on if singleword expansion -
5311 * important for not getting v=$@ expand to many words. */
5312 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5314 /* Is this variable quoted and thus expansion can't be null?
5315 * "$@" is special. Even if quoted, it can still
5316 * expand to nothing (not even an empty string),
5317 * thus it is excluded. */
5318 if ((first_ch & 0x7f) != '@')
5319 cant_be_null |= first_ch;
5321 switch (first_ch & 0x7f) {
5322 /* Highest bit in first_ch indicates that var is double-quoted */
5326 if (!G.global_argv[1])
5329 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5330 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5331 while (G.global_argv[i]) {
5332 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5333 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5334 if (G.global_argv[i++][0] && G.global_argv[i]) {
5335 /* this argv[] is not empty and not last:
5336 * put terminating NUL, start new word */
5337 o_addchr(output, '\0');
5338 debug_print_list("expand_vars_to_list[2]", output, n);
5339 n = o_save_ptr(output, n);
5340 debug_print_list("expand_vars_to_list[3]", output, n);
5344 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5345 * and in this case should treat it like '$*' - see 'else...' below */
5346 if (first_ch == ('@'|0x80) /* quoted $@ */
5347 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5350 o_addQstr(output, G.global_argv[i]);
5351 if (++i >= G.global_argc)
5353 o_addchr(output, '\0');
5354 debug_print_list("expand_vars_to_list[4]", output, n);
5355 n = o_save_ptr(output, n);
5357 } else { /* quoted $* (or v="$@" case): add as one word */
5359 o_addQstr(output, G.global_argv[i]);
5360 if (!G.global_argv[++i])
5363 o_addchr(output, G.ifs[0]);
5365 output->has_quoted_part = 1;
5369 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5370 /* "Empty variable", used to make "" etc to not disappear */
5371 output->has_quoted_part = 1;
5373 cant_be_null = 0x80;
5375 #if ENABLE_HUSH_TICK
5376 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5377 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5379 /* Can't just stuff it into output o_string,
5380 * expanded result may need to be globbed
5381 * and $IFS-splitted */
5382 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5383 G.last_exitcode = process_command_subs(&subst_result, arg);
5384 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5385 val = subst_result.data;
5388 #if ENABLE_SH_MATH_SUPPORT
5389 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5392 arg++; /* skip '+' */
5393 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5394 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5395 res = expand_and_evaluate_arith(arg, NULL);
5396 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5397 sprintf(arith_buf, ARITH_FMT, res);
5403 val = expand_one_var(&to_be_freed, arg, &p);
5404 IF_HUSH_TICK(store_val:)
5405 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5406 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5407 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5408 if (val && val[0]) {
5409 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5412 } else { /* quoted $VAR, val will be appended below */
5413 output->has_quoted_part = 1;
5414 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5415 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5418 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5420 if (val && val[0]) {
5421 o_addQstr(output, val);
5425 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5426 * Do the check to avoid writing to a const string. */
5427 if (*p != SPECIAL_VAR_SYMBOL)
5428 *p = SPECIAL_VAR_SYMBOL;
5430 #if ENABLE_HUSH_TICK
5431 o_free(&subst_result);
5434 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5438 o_addchr(output, '\0');
5439 n = o_save_ptr(output, n);
5441 debug_print_list("expand_vars_to_list[a]", output, n);
5442 /* this part is literal, and it was already pre-quoted
5443 * if needed (much earlier), do not use o_addQstr here! */
5444 o_addstr_with_NUL(output, arg);
5445 debug_print_list("expand_vars_to_list[b]", output, n);
5446 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5447 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5450 /* allow to reuse list[n] later without re-growth */
5451 output->has_empty_slot = 1;
5453 o_addchr(output, '\0');
5459 static char **expand_variables(char **argv, unsigned expflags)
5463 o_string output = NULL_O_STRING;
5465 output.o_expflags = expflags;
5469 n = expand_vars_to_list(&output, n, *argv);
5472 debug_print_list("expand_variables", &output, n);
5474 /* output.data (malloced in one block) gets returned in "list" */
5475 list = o_finalize_list(&output, n);
5476 debug_print_strings("expand_variables[1]", list);
5480 static char **expand_strvec_to_strvec(char **argv)
5482 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5485 #if ENABLE_HUSH_BASH_COMPAT
5486 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5488 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5492 /* Used for expansion of right hand of assignments,
5493 * $((...)), heredocs, variable espansion parts.
5495 * NB: should NOT do globbing!
5496 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5498 static char *expand_string_to_string(const char *str, int do_unbackslash)
5500 #if !ENABLE_HUSH_BASH_COMPAT
5501 const int do_unbackslash = 1;
5503 char *argv[2], **list;
5505 debug_printf_expand("string_to_string<='%s'\n", str);
5506 /* This is generally an optimization, but it also
5507 * handles "", which otherwise trips over !list[0] check below.
5508 * (is this ever happens that we actually get str="" here?)
5510 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5511 //TODO: Can use on strings with \ too, just unbackslash() them?
5512 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5513 return xstrdup(str);
5516 argv[0] = (char*)str;
5518 list = expand_variables(argv, do_unbackslash
5519 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5520 : EXP_FLAG_SINGLEWORD
5523 if (!list[0] || list[1])
5524 bb_error_msg_and_die("BUG in varexp2");
5525 /* actually, just move string 2*sizeof(char*) bytes back */
5526 overlapping_strcpy((char*)list, list[0]);
5528 unbackslash((char*)list);
5529 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5533 /* Used for "eval" builtin */
5534 static char* expand_strvec_to_string(char **argv)
5538 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5539 /* Convert all NULs to spaces */
5544 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5545 bb_error_msg_and_die("BUG in varexp3");
5546 /* bash uses ' ' regardless of $IFS contents */
5551 overlapping_strcpy((char*)list, list[0]);
5552 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5556 static char **expand_assignments(char **argv, int count)
5561 G.expanded_assignments = p = NULL;
5562 /* Expand assignments into one string each */
5563 for (i = 0; i < count; i++) {
5564 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5566 G.expanded_assignments = NULL;
5571 static void switch_off_special_sigs(unsigned mask)
5574 while ((mask >>= 1) != 0) {
5579 if (G.traps[sig] && !G.traps[sig][0])
5580 /* trap is '', has to remain SIG_IGN */
5583 G.traps[sig] = NULL;
5585 /* We are here only if no trap or trap was not '' */
5586 install_sighandler(sig, SIG_DFL);
5592 void re_execute_shell(char ***to_free, const char *s,
5593 char *g_argv0, char **g_argv,
5594 char **builtin_argv) NORETURN;
5596 static void reset_traps_to_defaults(void)
5598 /* This function is always called in a child shell
5599 * after fork (not vfork, NOMMU doesn't use this function).
5604 /* Child shells are not interactive.
5605 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5606 * Testcase: (while :; do :; done) + ^Z should background.
5607 * Same goes for SIGTERM, SIGHUP, SIGINT.
5609 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5610 if (!G.traps && !mask)
5611 return; /* already no traps and no special sigs */
5613 /* Switch off special sigs */
5614 switch_off_special_sigs(mask);
5616 G_fatal_sig_mask = 0;
5618 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5619 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5620 * remain set in G.special_sig_mask */
5625 /* Reset all sigs to default except ones with empty traps */
5626 for (sig = 0; sig < NSIG; sig++) {
5628 continue; /* no trap: nothing to do */
5629 if (!G.traps[sig][0])
5630 continue; /* empty trap: has to remain SIG_IGN */
5631 /* sig has non-empty trap, reset it: */
5633 G.traps[sig] = NULL;
5634 /* There is no signal for trap 0 (EXIT) */
5637 install_sighandler(sig, pick_sighandler(sig));
5643 static void re_execute_shell(char ***to_free, const char *s,
5644 char *g_argv0, char **g_argv,
5645 char **builtin_argv) NORETURN;
5646 static void re_execute_shell(char ***to_free, const char *s,
5647 char *g_argv0, char **g_argv,
5648 char **builtin_argv)
5650 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5651 /* delims + 2 * (number of bytes in printed hex numbers) */
5652 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5653 char *heredoc_argv[4];
5654 struct variable *cur;
5655 # if ENABLE_HUSH_FUNCTIONS
5656 struct function *funcp;
5660 unsigned long long empty_trap_mask;
5662 if (!g_argv0) { /* heredoc */
5663 argv = heredoc_argv;
5664 argv[0] = (char *) G.argv0_for_re_execing;
5665 argv[1] = (char *) "-<";
5666 argv[2] = (char *) s;
5668 pp = &argv[3]; /* used as pointer to empty environment */
5674 if (pp) while (*pp++)
5677 empty_trap_mask = 0;
5680 for (sig = 1; sig < NSIG; sig++) {
5681 if (G.traps[sig] && !G.traps[sig][0])
5682 empty_trap_mask |= 1LL << sig;
5686 sprintf(param_buf, NOMMU_HACK_FMT
5687 , (unsigned) G.root_pid
5688 , (unsigned) G.root_ppid
5689 , (unsigned) G.last_bg_pid
5690 , (unsigned) G.last_exitcode
5693 IF_HUSH_LOOPS(, G.depth_of_loop)
5695 # undef NOMMU_HACK_FMT
5696 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5697 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
5700 for (cur = G.top_var; cur; cur = cur->next) {
5701 if (!cur->flg_export || cur->flg_read_only)
5704 # if ENABLE_HUSH_FUNCTIONS
5705 for (funcp = G.top_func; funcp; funcp = funcp->next)
5711 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
5712 *pp++ = (char *) G.argv0_for_re_execing;
5714 for (cur = G.top_var; cur; cur = cur->next) {
5715 if (strcmp(cur->varstr, hush_version_str) == 0)
5717 if (cur->flg_read_only) {
5718 *pp++ = (char *) "-R";
5719 *pp++ = cur->varstr;
5720 } else if (!cur->flg_export) {
5721 *pp++ = (char *) "-V";
5722 *pp++ = cur->varstr;
5725 # if ENABLE_HUSH_FUNCTIONS
5726 for (funcp = G.top_func; funcp; funcp = funcp->next) {
5727 *pp++ = (char *) "-F";
5728 *pp++ = funcp->name;
5729 *pp++ = funcp->body_as_string;
5732 /* We can pass activated traps here. Say, -Tnn:trap_string
5734 * However, POSIX says that subshells reset signals with traps
5736 * I tested bash-3.2 and it not only does that with true subshells
5737 * of the form ( list ), but with any forked children shells.
5738 * I set trap "echo W" WINCH; and then tried:
5740 * { echo 1; sleep 20; echo 2; } &
5741 * while true; do echo 1; sleep 20; echo 2; break; done &
5742 * true | { echo 1; sleep 20; echo 2; } | cat
5744 * In all these cases sending SIGWINCH to the child shell
5745 * did not run the trap. If I add trap "echo V" WINCH;
5746 * _inside_ group (just before echo 1), it works.
5748 * I conclude it means we don't need to pass active traps here.
5750 *pp++ = (char *) "-c";
5753 while (*++builtin_argv)
5754 *pp++ = *builtin_argv;
5755 *pp++ = (char *) "";
5760 /* *pp = NULL; - is already there */
5764 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
5765 /* Don't propagate SIG_IGN to the child */
5766 if (SPECIAL_JOBSTOP_SIGS != 0)
5767 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
5768 execve(bb_busybox_exec_path, argv, pp);
5769 /* Fallback. Useful for init=/bin/hush usage etc */
5770 if (argv[0][0] == '/')
5771 execve(argv[0], argv, pp);
5772 xfunc_error_retval = 127;
5773 bb_error_msg_and_die("can't re-execute the shell");
5775 #endif /* !BB_MMU */
5778 static int run_and_free_list(struct pipe *pi);
5780 /* Executing from string: eval, sh -c '...'
5781 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
5782 * end_trigger controls how often we stop parsing
5783 * NUL: parse all, execute, return
5784 * ';': parse till ';' or newline, execute, repeat till EOF
5786 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
5788 /* Why we need empty flag?
5789 * An obscure corner case "false; ``; echo $?":
5790 * empty command in `` should still set $? to 0.
5791 * But we can't just set $? to 0 at the start,
5792 * this breaks "false; echo `echo $?`" case.
5796 struct pipe *pipe_list;
5798 #if ENABLE_HUSH_INTERACTIVE
5799 if (end_trigger == ';')
5800 inp->promptmode = 0; /* PS1 */
5802 pipe_list = parse_stream(NULL, inp, end_trigger);
5803 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
5804 /* If we are in "big" script
5805 * (not in `cmd` or something similar)...
5807 if (pipe_list == ERR_PTR && end_trigger == ';') {
5808 /* Discard cached input (rest of line) */
5809 int ch = inp->last_char;
5810 while (ch != EOF && ch != '\n') {
5811 //bb_error_msg("Discarded:'%c'", ch);
5816 /* This stream isn't empty */
5820 if (!pipe_list && empty)
5821 G.last_exitcode = 0;
5824 debug_print_tree(pipe_list, 0);
5825 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
5826 run_and_free_list(pipe_list);
5828 #if ENABLE_HUSH_FUNCTIONS
5829 if (G.flag_return_in_progress == 1)
5835 static void parse_and_run_string(const char *s)
5837 struct in_str input;
5838 setup_string_in_str(&input, s);
5839 parse_and_run_stream(&input, '\0');
5842 static void parse_and_run_file(FILE *f)
5844 struct in_str input;
5845 setup_file_in_str(&input, f);
5846 parse_and_run_stream(&input, ';');
5849 #if ENABLE_HUSH_TICK
5850 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
5855 char **to_free = NULL;
5859 pid = BB_MMU ? xfork() : xvfork();
5860 if (pid == 0) { /* child */
5861 disable_restore_tty_pgrp_on_exit();
5862 /* Process substitution is not considered to be usual
5863 * 'command execution'.
5864 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
5871 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
5872 close(channel[0]); /* NB: close _first_, then move fd! */
5873 xmove_fd(channel[1], 1);
5874 /* Prevent it from trying to handle ctrl-z etc */
5875 IF_HUSH_JOB(G.run_list_level = 1;)
5876 /* Awful hack for `trap` or $(trap).
5878 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
5879 * contains an example where "trap" is executed in a subshell:
5881 * save_traps=$(trap)
5883 * eval "$save_traps"
5885 * Standard does not say that "trap" in subshell shall print
5886 * parent shell's traps. It only says that its output
5887 * must have suitable form, but then, in the above example
5888 * (which is not supposed to be normative), it implies that.
5890 * bash (and probably other shell) does implement it
5891 * (traps are reset to defaults, but "trap" still shows them),
5892 * but as a result, "trap" logic is hopelessly messed up:
5895 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
5896 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
5897 * # true | trap <--- trap is in subshell - no output (ditto)
5898 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
5899 * trap -- 'echo Ho' SIGWINCH
5900 * # echo `(trap)` <--- in subshell in subshell - output
5901 * trap -- 'echo Ho' SIGWINCH
5902 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
5903 * trap -- 'echo Ho' SIGWINCH
5905 * The rules when to forget and when to not forget traps
5906 * get really complex and nonsensical.
5908 * Our solution: ONLY bare $(trap) or `trap` is special.
5910 s = skip_whitespace(s);
5911 if (is_prefixed_with(s, "trap")
5912 && skip_whitespace(s + 4)[0] == '\0'
5914 static const char *const argv[] = { NULL, NULL };
5915 builtin_trap((char**)argv);
5916 exit(0); /* not _exit() - we need to fflush */
5919 reset_traps_to_defaults();
5920 parse_and_run_string(s);
5921 _exit(G.last_exitcode);
5923 /* We re-execute after vfork on NOMMU. This makes this script safe:
5924 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
5925 * huge=`cat BIG` # was blocking here forever
5928 re_execute_shell(&to_free,
5938 # if ENABLE_HUSH_FAST
5940 //bb_error_msg("[%d] fork in generate_stream_from_string:"
5941 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
5942 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
5944 enable_restore_tty_pgrp_on_exit();
5949 close_on_exec_on(channel[0]);
5950 return xfdopen_for_read(channel[0]);
5953 /* Return code is exit status of the process that is run. */
5954 static int process_command_subs(o_string *dest, const char *s)
5957 struct in_str pipe_str;
5959 int status, ch, eol_cnt;
5961 fp = generate_stream_from_string(s, &pid);
5963 /* Now send results of command back into original context */
5964 setup_file_in_str(&pipe_str, fp);
5966 while ((ch = i_getch(&pipe_str)) != EOF) {
5972 o_addchr(dest, '\n');
5975 o_addQchr(dest, ch);
5978 debug_printf("done reading from `cmd` pipe, closing it\n");
5980 /* We need to extract exitcode. Test case
5981 * "true; echo `sleep 1; false` $?"
5983 safe_waitpid(pid, &status, 0);
5984 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
5985 return WEXITSTATUS(status);
5987 #endif /* ENABLE_HUSH_TICK */
5990 static void setup_heredoc(struct redir_struct *redir)
5992 struct fd_pair pair;
5995 /* the _body_ of heredoc (misleading field name) */
5996 const char *heredoc = redir->rd_filename;
6003 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6004 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6008 len = strlen(heredoc);
6010 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6012 xmove_fd(pair.rd, redir->rd_fd);
6014 /* Try writing without forking. Newer kernels have
6015 * dynamically growing pipes. Must use non-blocking write! */
6018 written = write(pair.wr, heredoc, len);
6029 ndelay_off(pair.wr);
6031 /* Okay, pipe buffer was not big enough */
6032 /* Note: we must not create a stray child (bastard? :)
6033 * for the unsuspecting parent process. Child creates a grandchild
6034 * and exits before parent execs the process which consumes heredoc
6035 * (that exec happens after we return from this function) */
6042 disable_restore_tty_pgrp_on_exit();
6043 pid = BB_MMU ? xfork() : xvfork();
6047 close(redir->rd_fd); /* read side of the pipe */
6049 full_write(pair.wr, heredoc, len); /* may loop or block */
6052 /* Delegate blocking writes to another process */
6053 xmove_fd(pair.wr, STDOUT_FILENO);
6054 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6058 #if ENABLE_HUSH_FAST
6060 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6062 enable_restore_tty_pgrp_on_exit();
6068 wait(NULL); /* wait till child has died */
6071 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6072 * and stderr if they are redirected. */
6073 static int setup_redirects(struct command *prog, int squirrel[])
6076 struct redir_struct *redir;
6078 for (redir = prog->redirects; redir; redir = redir->next) {
6079 if (redir->rd_type == REDIRECT_HEREDOC2) {
6080 /* rd_fd<<HERE case */
6081 if (squirrel && redir->rd_fd < 3
6082 && squirrel[redir->rd_fd] < 0
6084 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6086 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6088 debug_printf_parse("set heredoc '%s'\n",
6089 redir->rd_filename);
6090 setup_heredoc(redir);
6094 if (redir->rd_dup == REDIRFD_TO_FILE) {
6095 /* rd_fd<*>file case (<*> is <,>,>>,<>) */
6097 if (redir->rd_filename == NULL) {
6098 /* Something went wrong in the parse.
6099 * Pretend it didn't happen */
6100 bb_error_msg("bug in redirect parse");
6103 mode = redir_table[redir->rd_type].mode;
6104 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6105 openfd = open_or_warn(p, mode);
6108 /* this could get lost if stderr has been redirected, but
6109 * bash and ash both lose it as well (though zsh doesn't!) */
6110 //what the above comment tries to say?
6114 /* rd_fd<*>rd_dup or rd_fd<*>- cases */
6115 openfd = redir->rd_dup;
6118 if (openfd != redir->rd_fd) {
6119 if (squirrel && redir->rd_fd < 3
6120 && squirrel[redir->rd_fd] < 0
6122 squirrel[redir->rd_fd] = dup(redir->rd_fd);
6124 if (openfd == REDIRFD_CLOSE) {
6125 /* "n>-" means "close me" */
6126 close(redir->rd_fd);
6128 xdup2(openfd, redir->rd_fd);
6129 if (redir->rd_dup == REDIRFD_TO_FILE)
6137 static void restore_redirects(int squirrel[])
6140 for (i = 0; i < 3; i++) {
6143 /* We simply die on error */
6149 static char *find_in_path(const char *arg)
6152 const char *PATH = get_local_var_value("PATH");
6158 const char *end = strchrnul(PATH, ':');
6159 int sz = end - PATH; /* must be int! */
6163 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6165 /* We have xxx::yyyy in $PATH,
6166 * it means "use current dir" */
6169 if (access(ret, F_OK) == 0)
6182 static const struct built_in_command *find_builtin_helper(const char *name,
6183 const struct built_in_command *x,
6184 const struct built_in_command *end)
6187 if (strcmp(name, x->b_cmd) != 0) {
6191 debug_printf_exec("found builtin '%s'\n", name);
6196 static const struct built_in_command *find_builtin1(const char *name)
6198 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6200 static const struct built_in_command *find_builtin(const char *name)
6202 const struct built_in_command *x = find_builtin1(name);
6205 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6208 #if ENABLE_HUSH_FUNCTIONS
6209 static struct function **find_function_slot(const char *name)
6211 struct function **funcpp = &G.top_func;
6213 if (strcmp(name, (*funcpp)->name) == 0) {
6216 funcpp = &(*funcpp)->next;
6221 static const struct function *find_function(const char *name)
6223 const struct function *funcp = *find_function_slot(name);
6225 debug_printf_exec("found function '%s'\n", name);
6229 /* Note: takes ownership on name ptr */
6230 static struct function *new_function(char *name)
6232 struct function **funcpp = find_function_slot(name);
6233 struct function *funcp = *funcpp;
6235 if (funcp != NULL) {
6236 struct command *cmd = funcp->parent_cmd;
6237 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6239 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6241 /* Note: if !funcp->body, do not free body_as_string!
6242 * This is a special case of "-F name body" function:
6243 * body_as_string was not malloced! */
6245 free_pipe_list(funcp->body);
6247 free(funcp->body_as_string);
6251 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6252 cmd->argv[0] = funcp->name;
6253 cmd->group = funcp->body;
6255 cmd->group_as_string = funcp->body_as_string;
6259 debug_printf_exec("remembering new function '%s'\n", name);
6260 funcp = *funcpp = xzalloc(sizeof(*funcp));
6261 /*funcp->next = NULL;*/
6268 static void unset_func(const char *name)
6270 struct function **funcpp = find_function_slot(name);
6271 struct function *funcp = *funcpp;
6273 if (funcp != NULL) {
6274 debug_printf_exec("freeing function '%s'\n", funcp->name);
6275 *funcpp = funcp->next;
6276 /* funcp is unlinked now, deleting it.
6277 * Note: if !funcp->body, the function was created by
6278 * "-F name body", do not free ->body_as_string
6279 * and ->name as they were not malloced. */
6281 free_pipe_list(funcp->body);
6284 free(funcp->body_as_string);
6292 #define exec_function(to_free, funcp, argv) \
6293 exec_function(funcp, argv)
6295 static void exec_function(char ***to_free,
6296 const struct function *funcp,
6297 char **argv) NORETURN;
6298 static void exec_function(char ***to_free,
6299 const struct function *funcp,
6305 argv[0] = G.global_argv[0];
6306 G.global_argv = argv;
6310 /* On MMU, funcp->body is always non-NULL */
6311 n = run_list(funcp->body);
6315 re_execute_shell(to_free,
6316 funcp->body_as_string,
6323 static int run_function(const struct function *funcp, char **argv)
6329 save_and_replace_G_args(&sv, argv);
6331 /* "we are in function, ok to use return" */
6332 sv_flg = G.flag_return_in_progress;
6333 G.flag_return_in_progress = -1;
6334 # if ENABLE_HUSH_LOCAL
6335 G.func_nest_level++;
6338 /* On MMU, funcp->body is always non-NULL */
6341 /* Function defined by -F */
6342 parse_and_run_string(funcp->body_as_string);
6343 rc = G.last_exitcode;
6347 rc = run_list(funcp->body);
6350 # if ENABLE_HUSH_LOCAL
6352 struct variable *var;
6353 struct variable **var_pp;
6355 var_pp = &G.top_var;
6356 while ((var = *var_pp) != NULL) {
6357 if (var->func_nest_level < G.func_nest_level) {
6358 var_pp = &var->next;
6362 if (var->flg_export)
6363 bb_unsetenv(var->varstr);
6364 /* Remove from global list */
6365 *var_pp = var->next;
6371 G.func_nest_level--;
6374 G.flag_return_in_progress = sv_flg;
6376 restore_G_args(&sv, argv);
6380 #endif /* ENABLE_HUSH_FUNCTIONS */
6384 #define exec_builtin(to_free, x, argv) \
6385 exec_builtin(x, argv)
6387 #define exec_builtin(to_free, x, argv) \
6388 exec_builtin(to_free, argv)
6390 static void exec_builtin(char ***to_free,
6391 const struct built_in_command *x,
6392 char **argv) NORETURN;
6393 static void exec_builtin(char ***to_free,
6394 const struct built_in_command *x,
6400 rcode = x->b_function(argv);
6405 /* On NOMMU, we must never block!
6406 * Example: { sleep 99 | read line; } & echo Ok
6408 re_execute_shell(to_free,
6417 static void execvp_or_die(char **argv) NORETURN;
6418 static void execvp_or_die(char **argv)
6420 debug_printf_exec("execing '%s'\n", argv[0]);
6421 /* Don't propagate SIG_IGN to the child */
6422 if (SPECIAL_JOBSTOP_SIGS != 0)
6423 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6424 execvp(argv[0], argv);
6425 bb_perror_msg("can't execute '%s'", argv[0]);
6426 _exit(127); /* bash compat */
6429 #if ENABLE_HUSH_MODE_X
6430 static void dump_cmd_in_x_mode(char **argv)
6432 if (G_x_mode && argv) {
6433 /* We want to output the line in one write op */
6441 len += strlen(argv[n++]) + 1;
6447 p += sprintf(p, " %s", argv[n++]);
6455 # define dump_cmd_in_x_mode(argv) ((void)0)
6459 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6460 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6461 #define pseudo_exec(nommu_save, command, argv_expanded) \
6462 pseudo_exec(command, argv_expanded)
6465 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6467 * Don't exit() here. If you don't exec, use _exit instead.
6468 * The at_exit handlers apparently confuse the calling process,
6469 * in particular stdin handling. Not sure why? -- because of vfork! (vda) */
6470 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6471 char **argv, int assignment_cnt,
6472 char **argv_expanded) NORETURN;
6473 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6474 char **argv, int assignment_cnt,
6475 char **argv_expanded)
6479 new_env = expand_assignments(argv, assignment_cnt);
6480 dump_cmd_in_x_mode(new_env);
6482 if (!argv[assignment_cnt]) {
6483 /* Case when we are here: ... | var=val | ...
6484 * (note that we do not exit early, i.e., do not optimize out
6485 * expand_assignments(): think about ... | var=`sleep 1` | ...
6487 free_strings(new_env);
6488 _exit(EXIT_SUCCESS);
6492 set_vars_and_save_old(new_env);
6493 free(new_env); /* optional */
6494 /* we can also destroy set_vars_and_save_old's return value,
6497 nommu_save->new_env = new_env;
6498 nommu_save->old_vars = set_vars_and_save_old(new_env);
6501 if (argv_expanded) {
6502 argv = argv_expanded;
6504 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6506 nommu_save->argv = argv;
6509 dump_cmd_in_x_mode(argv);
6511 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6512 if (strchr(argv[0], '/') != NULL)
6516 /* Check if the command matches any of the builtins.
6517 * Depending on context, this might be redundant. But it's
6518 * easier to waste a few CPU cycles than it is to figure out
6519 * if this is one of those cases.
6522 /* On NOMMU, it is more expensive to re-execute shell
6523 * just in order to run echo or test builtin.
6524 * It's better to skip it here and run corresponding
6525 * non-builtin later. */
6526 const struct built_in_command *x;
6527 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6529 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6532 #if ENABLE_HUSH_FUNCTIONS
6533 /* Check if the command matches any functions */
6535 const struct function *funcp = find_function(argv[0]);
6537 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6542 #if ENABLE_FEATURE_SH_STANDALONE
6543 /* Check if the command matches any busybox applets */
6545 int a = find_applet_by_name(argv[0]);
6547 # if BB_MMU /* see above why on NOMMU it is not allowed */
6548 if (APPLET_IS_NOEXEC(a)) {
6549 debug_printf_exec("running applet '%s'\n", argv[0]);
6550 run_applet_no_and_exit(a, argv);
6553 /* Re-exec ourselves */
6554 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6555 /* Don't propagate SIG_IGN to the child */
6556 if (SPECIAL_JOBSTOP_SIGS != 0)
6557 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6558 execv(bb_busybox_exec_path, argv);
6559 /* If they called chroot or otherwise made the binary no longer
6560 * executable, fall through */
6565 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6568 execvp_or_die(argv);
6571 /* Called after [v]fork() in run_pipe
6573 static void pseudo_exec(nommu_save_t *nommu_save,
6574 struct command *command,
6575 char **argv_expanded) NORETURN;
6576 static void pseudo_exec(nommu_save_t *nommu_save,
6577 struct command *command,
6578 char **argv_expanded)
6580 if (command->argv) {
6581 pseudo_exec_argv(nommu_save, command->argv,
6582 command->assignment_cnt, argv_expanded);
6585 if (command->group) {
6586 /* Cases when we are here:
6589 * ... | ( list ) | ...
6590 * ... | { list } | ...
6594 debug_printf_exec("pseudo_exec: run_list\n");
6595 reset_traps_to_defaults();
6596 rcode = run_list(command->group);
6597 /* OK to leak memory by not calling free_pipe_list,
6598 * since this process is about to exit */
6601 re_execute_shell(&nommu_save->argv_from_re_execing,
6602 command->group_as_string,
6609 /* Case when we are here: ... | >file */
6610 debug_printf_exec("pseudo_exec'ed null command\n");
6611 _exit(EXIT_SUCCESS);
6615 static const char *get_cmdtext(struct pipe *pi)
6621 /* This is subtle. ->cmdtext is created only on first backgrounding.
6622 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6623 * On subsequent bg argv is trashed, but we won't use it */
6626 argv = pi->cmds[0].argv;
6627 if (!argv || !argv[0]) {
6628 pi->cmdtext = xzalloc(1);
6634 len += strlen(*argv) + 1;
6638 argv = pi->cmds[0].argv;
6640 len = strlen(*argv);
6641 memcpy(p, *argv, len);
6649 static void insert_bg_job(struct pipe *pi)
6651 struct pipe *job, **jobp;
6654 /* Linear search for the ID of the job to use */
6656 for (job = G.job_list; job; job = job->next)
6657 if (job->jobid >= pi->jobid)
6658 pi->jobid = job->jobid + 1;
6660 /* Add job to the list of running jobs */
6662 while ((job = *jobp) != NULL)
6664 job = *jobp = xmalloc(sizeof(*job));
6666 *job = *pi; /* physical copy */
6668 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
6669 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
6670 for (i = 0; i < pi->num_cmds; i++) {
6671 job->cmds[i].pid = pi->cmds[i].pid;
6672 /* all other fields are not used and stay zero */
6674 job->cmdtext = xstrdup(get_cmdtext(pi));
6676 if (G_interactive_fd)
6677 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
6678 G.last_jobid = job->jobid;
6681 static void remove_bg_job(struct pipe *pi)
6683 struct pipe *prev_pipe;
6685 if (pi == G.job_list) {
6686 G.job_list = pi->next;
6688 prev_pipe = G.job_list;
6689 while (prev_pipe->next != pi)
6690 prev_pipe = prev_pipe->next;
6691 prev_pipe->next = pi->next;
6694 G.last_jobid = G.job_list->jobid;
6699 /* Remove a backgrounded job */
6700 static void delete_finished_bg_job(struct pipe *pi)
6707 /* Check to see if any processes have exited -- if they
6708 * have, figure out why and see if a job has completed */
6709 static int checkjobs(struct pipe *fg_pipe)
6719 debug_printf_jobs("checkjobs %p\n", fg_pipe);
6721 attributes = WUNTRACED;
6722 if (fg_pipe == NULL)
6723 attributes |= WNOHANG;
6726 #if ENABLE_HUSH_FAST
6727 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
6728 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
6729 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
6730 /* There was neither fork nor SIGCHLD since last waitpid */
6731 /* Avoid doing waitpid syscall if possible */
6732 if (!G.we_have_children) {
6736 if (fg_pipe == NULL) { /* is WNOHANG set? */
6737 /* We have children, but they did not exit
6738 * or stop yet (we saw no SIGCHLD) */
6741 /* else: !WNOHANG, waitpid will block, can't short-circuit */
6745 /* Do we do this right?
6746 * bash-3.00# sleep 20 | false
6748 * [3]+ Stopped sleep 20 | false
6749 * bash-3.00# echo $?
6750 * 1 <========== bg pipe is not fully done, but exitcode is already known!
6751 * [hush 1.14.0: yes we do it right]
6758 #if ENABLE_HUSH_FAST
6759 i = G.count_SIGCHLD;
6761 childpid = waitpid(-1, &status, attributes);
6762 if (childpid <= 0) {
6763 if (childpid && errno != ECHILD)
6764 bb_perror_msg("waitpid");
6765 #if ENABLE_HUSH_FAST
6766 else { /* Until next SIGCHLD, waitpid's are useless */
6767 G.we_have_children = (childpid == 0);
6768 G.handled_SIGCHLD = i;
6769 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6774 dead = WIFEXITED(status) || WIFSIGNALED(status);
6777 if (WIFSTOPPED(status))
6778 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
6779 childpid, WSTOPSIG(status), WEXITSTATUS(status));
6780 if (WIFSIGNALED(status))
6781 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
6782 childpid, WTERMSIG(status), WEXITSTATUS(status));
6783 if (WIFEXITED(status))
6784 debug_printf_jobs("pid %d exited, exitcode %d\n",
6785 childpid, WEXITSTATUS(status));
6787 /* Were we asked to wait for fg pipe? */
6789 i = fg_pipe->num_cmds;
6791 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
6792 if (fg_pipe->cmds[i].pid != childpid)
6796 fg_pipe->cmds[i].pid = 0;
6797 fg_pipe->alive_cmds--;
6798 ex = WEXITSTATUS(status);
6799 /* bash prints killer signal's name for *last*
6800 * process in pipe (prints just newline for SIGINT/SIGPIPE).
6801 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
6803 if (WIFSIGNALED(status)) {
6804 int sig = WTERMSIG(status);
6805 if (i == fg_pipe->num_cmds-1)
6806 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
6807 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
6808 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
6809 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
6810 * Maybe we need to use sig | 128? */
6813 fg_pipe->cmds[i].cmd_exitcode = ex;
6815 fg_pipe->stopped_cmds++;
6817 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
6818 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
6819 if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) {
6820 /* All processes in fg pipe have exited or stopped */
6821 i = fg_pipe->num_cmds;
6823 rcode = fg_pipe->cmds[i].cmd_exitcode;
6824 /* usually last process gives overall exitstatus,
6825 * but with "set -o pipefail", last *failed* process does */
6826 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
6829 IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;)
6830 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
6831 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
6832 * and "killall -STOP cat" */
6833 if (G_interactive_fd) {
6835 if (fg_pipe->alive_cmds != 0)
6836 insert_bg_job(fg_pipe);
6840 if (fg_pipe->alive_cmds == 0)
6843 /* There are still running processes in the fg pipe */
6844 goto wait_more; /* do waitpid again */
6846 /* it wasnt fg_pipe, look for process in bg pipes */
6850 /* We asked to wait for bg or orphaned children */
6851 /* No need to remember exitcode in this case */
6852 for (pi = G.job_list; pi; pi = pi->next) {
6853 for (i = 0; i < pi->num_cmds; i++) {
6854 if (pi->cmds[i].pid == childpid)
6855 goto found_pi_and_prognum;
6858 /* Happens when shell is used as init process (init=/bin/sh) */
6859 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
6860 continue; /* do waitpid again */
6862 found_pi_and_prognum:
6865 pi->cmds[i].pid = 0;
6867 if (!pi->alive_cmds) {
6868 if (G_interactive_fd)
6869 printf(JOB_STATUS_FORMAT, pi->jobid,
6870 "Done", pi->cmdtext);
6871 delete_finished_bg_job(pi);
6878 } /* while (waitpid succeeds)... */
6884 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
6887 int rcode = checkjobs(fg_pipe);
6888 if (G_saved_tty_pgrp) {
6889 /* Job finished, move the shell to the foreground */
6890 p = getpgrp(); /* our process group id */
6891 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
6892 tcsetpgrp(G_interactive_fd, p);
6898 /* Start all the jobs, but don't wait for anything to finish.
6901 * Return code is normally -1, when the caller has to wait for children
6902 * to finish to determine the exit status of the pipe. If the pipe
6903 * is a simple builtin command, however, the action is done by the
6904 * time run_pipe returns, and the exit code is provided as the
6907 * Returns -1 only if started some children. IOW: we have to
6908 * mask out retvals of builtins etc with 0xff!
6910 * The only case when we do not need to [v]fork is when the pipe
6911 * is single, non-backgrounded, non-subshell command. Examples:
6912 * cmd ; ... { list } ; ...
6913 * cmd && ... { list } && ...
6914 * cmd || ... { list } || ...
6915 * If it is, then we can run cmd as a builtin, NOFORK,
6916 * or (if SH_STANDALONE) an applet, and we can run the { list }
6917 * with run_list. If it isn't one of these, we fork and exec cmd.
6919 * Cases when we must fork:
6920 * non-single: cmd | cmd
6921 * backgrounded: cmd & { list } &
6922 * subshell: ( list ) [&]
6924 #if !ENABLE_HUSH_MODE_X
6925 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
6926 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
6928 static int redirect_and_varexp_helper(char ***new_env_p,
6929 struct variable **old_vars_p,
6930 struct command *command,
6932 char **argv_expanded)
6934 /* setup_redirects acts on file descriptors, not FILEs.
6935 * This is perfect for work that comes after exec().
6936 * Is it really safe for inline use? Experimentally,
6937 * things seem to work. */
6938 int rcode = setup_redirects(command, squirrel);
6940 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
6941 *new_env_p = new_env;
6942 dump_cmd_in_x_mode(new_env);
6943 dump_cmd_in_x_mode(argv_expanded);
6945 *old_vars_p = set_vars_and_save_old(new_env);
6949 static NOINLINE int run_pipe(struct pipe *pi)
6951 static const char *const null_ptr = NULL;
6955 struct command *command;
6956 char **argv_expanded;
6958 /* it is not always needed, but we aim to smaller code */
6959 int squirrel[] = { -1, -1, -1 };
6962 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
6965 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
6966 * Result should be 3 lines: q w e, qwe, q w e
6968 G.ifs = get_local_var_value("IFS");
6972 IF_HUSH_JOB(pi->pgrp = -1;)
6973 pi->stopped_cmds = 0;
6974 command = &pi->cmds[0];
6975 argv_expanded = NULL;
6977 if (pi->num_cmds != 1
6978 || pi->followup == PIPE_BG
6979 || command->cmd_type == CMD_SUBSHELL
6986 debug_printf_exec(": group:%p argv:'%s'\n",
6987 command->group, command->argv ? command->argv[0] : "NONE");
6989 if (command->group) {
6990 #if ENABLE_HUSH_FUNCTIONS
6991 if (command->cmd_type == CMD_FUNCDEF) {
6992 /* "executing" func () { list } */
6993 struct function *funcp;
6995 funcp = new_function(command->argv[0]);
6996 /* funcp->name is already set to argv[0] */
6997 funcp->body = command->group;
6999 funcp->body_as_string = command->group_as_string;
7000 command->group_as_string = NULL;
7002 command->group = NULL;
7003 command->argv[0] = NULL;
7004 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7005 funcp->parent_cmd = command;
7006 command->child_func = funcp;
7008 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7010 return EXIT_SUCCESS;
7014 debug_printf("non-subshell group\n");
7015 rcode = 1; /* exitcode if redir failed */
7016 if (setup_redirects(command, squirrel) == 0) {
7017 debug_printf_exec(": run_list\n");
7018 rcode = run_list(command->group) & 0xff;
7020 restore_redirects(squirrel);
7021 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7023 debug_printf_exec("run_pipe: return %d\n", rcode);
7027 argv = command->argv ? command->argv : (char **) &null_ptr;
7029 const struct built_in_command *x;
7030 #if ENABLE_HUSH_FUNCTIONS
7031 const struct function *funcp;
7035 char **new_env = NULL;
7036 struct variable *old_vars = NULL;
7038 if (argv[command->assignment_cnt] == NULL) {
7039 /* Assignments, but no command */
7040 /* Ensure redirects take effect (that is, create files).
7041 * Try "a=t >file" */
7042 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7043 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7044 /* Set shell variables */
7048 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7049 /* Do we need to flag set_local_var() errors?
7050 * "assignment to readonly var" and "putenv error"
7055 /* Redirect error sets $? to 1. Otherwise,
7056 * if evaluating assignment value set $?, retain it.
7057 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7059 rcode = G.last_exitcode;
7060 /* Exit, _skipping_ variable restoring code: */
7061 goto clean_up_and_ret0;
7063 #else /* Older, bigger, but more correct code */
7065 rcode = setup_redirects(command, squirrel);
7066 restore_redirects(squirrel);
7067 /* Set shell variables */
7069 bb_putchar_stderr('+');
7071 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7073 fprintf(stderr, " %s", p);
7074 debug_printf_exec("set shell var:'%s'->'%s'\n",
7076 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7077 /* Do we need to flag set_local_var() errors?
7078 * "assignment to readonly var" and "putenv error"
7083 bb_putchar_stderr('\n');
7084 /* Redirect error sets $? to 1. Otherwise,
7085 * if evaluating assignment value set $?, retain it.
7086 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7088 rcode = G.last_exitcode;
7089 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7091 debug_printf_exec("run_pipe: return %d\n", rcode);
7096 /* Expand the rest into (possibly) many strings each */
7097 #if ENABLE_HUSH_BASH_COMPAT
7098 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7099 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7103 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7106 /* if someone gives us an empty string: `cmd with empty output` */
7107 if (!argv_expanded[0]) {
7108 free(argv_expanded);
7110 return G.last_exitcode;
7113 x = find_builtin(argv_expanded[0]);
7114 #if ENABLE_HUSH_FUNCTIONS
7117 funcp = find_function(argv_expanded[0]);
7121 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7122 debug_printf("exec with redirects only\n");
7123 rcode = setup_redirects(command, NULL);
7124 goto clean_up_and_ret1;
7127 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7130 debug_printf_exec(": builtin '%s' '%s'...\n",
7131 x->b_cmd, argv_expanded[1]);
7133 rcode = x->b_function(argv_expanded) & 0xff;
7136 #if ENABLE_HUSH_FUNCTIONS
7138 # if ENABLE_HUSH_LOCAL
7139 struct variable **sv;
7140 sv = G.shadowed_vars_pp;
7141 G.shadowed_vars_pp = &old_vars;
7143 debug_printf_exec(": function '%s' '%s'...\n",
7144 funcp->name, argv_expanded[1]);
7145 rcode = run_function(funcp, argv_expanded) & 0xff;
7146 # if ENABLE_HUSH_LOCAL
7147 G.shadowed_vars_pp = sv;
7153 unset_vars(new_env);
7155 /* clean_up_and_ret0: */
7156 restore_redirects(squirrel);
7158 free(argv_expanded);
7159 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7161 debug_printf_exec("run_pipe return %d\n", rcode);
7165 if (ENABLE_FEATURE_SH_NOFORK) {
7166 int n = find_applet_by_name(argv_expanded[0]);
7167 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7168 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7170 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7171 argv_expanded[0], argv_expanded[1]);
7172 rcode = run_nofork_applet(n, argv_expanded);
7174 goto clean_up_and_ret;
7177 /* It is neither builtin nor applet. We must fork. */
7181 /* NB: argv_expanded may already be created, and that
7182 * might include `cmd` runs! Do not rerun it! We *must*
7183 * use argv_expanded if it's non-NULL */
7185 /* Going to fork a child per each pipe member */
7190 while (cmd_no < pi->num_cmds) {
7191 struct fd_pair pipefds;
7193 volatile nommu_save_t nommu_save;
7194 nommu_save.new_env = NULL;
7195 nommu_save.old_vars = NULL;
7196 nommu_save.argv = NULL;
7197 nommu_save.argv_from_re_execing = NULL;
7199 command = &pi->cmds[cmd_no];
7201 if (command->argv) {
7202 debug_printf_exec(": pipe member '%s' '%s'...\n",
7203 command->argv[0], command->argv[1]);
7205 debug_printf_exec(": pipe member with no argv\n");
7208 /* pipes are inserted between pairs of commands */
7211 if (cmd_no < pi->num_cmds)
7212 xpiped_pair(pipefds);
7214 command->pid = BB_MMU ? fork() : vfork();
7215 if (!command->pid) { /* child */
7217 disable_restore_tty_pgrp_on_exit();
7218 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7220 /* Every child adds itself to new process group
7221 * with pgid == pid_of_first_child_in_pipe */
7222 if (G.run_list_level == 1 && G_interactive_fd) {
7225 if (pgrp < 0) /* true for 1st process only */
7227 if (setpgid(0, pgrp) == 0
7228 && pi->followup != PIPE_BG
7229 && G_saved_tty_pgrp /* we have ctty */
7231 /* We do it in *every* child, not just first,
7233 tcsetpgrp(G_interactive_fd, pgrp);
7237 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7238 /* 1st cmd in backgrounded pipe
7239 * should have its stdin /dev/null'ed */
7241 if (open(bb_dev_null, O_RDONLY))
7242 xopen("/", O_RDONLY);
7244 xmove_fd(next_infd, 0);
7246 xmove_fd(pipefds.wr, 1);
7249 /* Like bash, explicit redirects override pipes,
7250 * and the pipe fd is available for dup'ing. */
7251 if (setup_redirects(command, NULL))
7254 /* Stores to nommu_save list of env vars putenv'ed
7255 * (NOMMU, on MMU we don't need that) */
7256 /* cast away volatility... */
7257 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7258 /* pseudo_exec() does not return */
7261 /* parent or error */
7262 #if ENABLE_HUSH_FAST
7264 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7266 enable_restore_tty_pgrp_on_exit();
7268 /* Clean up after vforked child */
7269 free(nommu_save.argv);
7270 free(nommu_save.argv_from_re_execing);
7271 unset_vars(nommu_save.new_env);
7272 add_vars(nommu_save.old_vars);
7274 free(argv_expanded);
7275 argv_expanded = NULL;
7276 if (command->pid < 0) { /* [v]fork failed */
7277 /* Clearly indicate, was it fork or vfork */
7278 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7282 /* Second and next children need to know pid of first one */
7284 pi->pgrp = command->pid;
7290 if (cmd_no < pi->num_cmds)
7292 /* Pass read (output) pipe end to next iteration */
7293 next_infd = pipefds.rd;
7296 if (!pi->alive_cmds) {
7298 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7303 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7307 /* NB: called by pseudo_exec, and therefore must not modify any
7308 * global data until exec/_exit (we can be a child after vfork!) */
7309 static int run_list(struct pipe *pi)
7311 #if ENABLE_HUSH_CASE
7312 char *case_word = NULL;
7314 #if ENABLE_HUSH_LOOPS
7315 struct pipe *loop_top = NULL;
7316 char **for_lcur = NULL;
7317 char **for_list = NULL;
7319 smallint last_followup;
7321 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7322 smalluint cond_code = 0;
7324 enum { cond_code = 0 };
7327 smallint rword; /* RES_foo */
7328 smallint last_rword; /* ditto */
7331 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7334 #if ENABLE_HUSH_LOOPS
7335 /* Check syntax for "for" */
7338 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7339 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7341 /* current word is FOR or IN (BOLD in comments below) */
7342 if (cpipe->next == NULL) {
7343 syntax_error("malformed for");
7345 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7348 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7349 if (cpipe->next->res_word == RES_DO)
7351 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7352 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7353 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7355 syntax_error("malformed for");
7357 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7364 /* Past this point, all code paths should jump to ret: label
7365 * in order to return, no direct "return" statements please.
7366 * This helps to ensure that no memory is leaked. */
7374 last_rword = RES_XXXX;
7376 last_followup = PIPE_SEQ;
7377 rcode = G.last_exitcode;
7379 /* Go through list of pipes, (maybe) executing them. */
7380 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7384 IF_HAS_KEYWORDS(rword = pi->res_word;)
7385 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7386 rword, cond_code, last_rword);
7387 #if ENABLE_HUSH_LOOPS
7388 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7389 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7391 /* start of a loop: remember where loop starts */
7396 /* Still in the same "if...", "then..." or "do..." branch? */
7397 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7398 if ((rcode == 0 && last_followup == PIPE_OR)
7399 || (rcode != 0 && last_followup == PIPE_AND)
7401 /* It is "<true> || CMD" or "<false> && CMD"
7402 * and we should not execute CMD */
7403 debug_printf_exec("skipped cmd because of || or &&\n");
7404 last_followup = pi->followup;
7405 goto dont_check_jobs_but_continue;
7408 last_followup = pi->followup;
7409 IF_HAS_KEYWORDS(last_rword = rword;)
7412 if (rword == RES_THEN) {
7413 /* if false; then ... fi has exitcode 0! */
7414 G.last_exitcode = rcode = EXIT_SUCCESS;
7415 /* "if <false> THEN cmd": skip cmd */
7419 if (rword == RES_ELSE || rword == RES_ELIF) {
7420 /* "if <true> then ... ELSE/ELIF cmd":
7421 * skip cmd and all following ones */
7426 #if ENABLE_HUSH_LOOPS
7427 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7429 /* first loop through for */
7431 static const char encoded_dollar_at[] ALIGN1 = {
7432 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7433 }; /* encoded representation of "$@" */
7434 static const char *const encoded_dollar_at_argv[] = {
7435 encoded_dollar_at, NULL
7436 }; /* argv list with one element: "$@" */
7439 vals = (char**)encoded_dollar_at_argv;
7440 if (pi->next->res_word == RES_IN) {
7441 /* if no variable values after "in" we skip "for" */
7442 if (!pi->next->cmds[0].argv) {
7443 G.last_exitcode = rcode = EXIT_SUCCESS;
7444 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7447 vals = pi->next->cmds[0].argv;
7448 } /* else: "for var; do..." -> assume "$@" list */
7449 /* create list of variable values */
7450 debug_print_strings("for_list made from", vals);
7451 for_list = expand_strvec_to_strvec(vals);
7452 for_lcur = for_list;
7453 debug_print_strings("for_list", for_list);
7456 /* "for" loop is over, clean up */
7462 /* Insert next value from for_lcur */
7463 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7464 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7467 if (rword == RES_IN) {
7468 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7470 if (rword == RES_DONE) {
7471 continue; /* "done" has no cmds too */
7474 #if ENABLE_HUSH_CASE
7475 if (rword == RES_CASE) {
7476 case_word = expand_strvec_to_string(pi->cmds->argv);
7479 if (rword == RES_MATCH) {
7482 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7484 /* all prev words didn't match, does this one match? */
7485 argv = pi->cmds->argv;
7487 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7488 /* TODO: which FNM_xxx flags to use? */
7489 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7491 if (cond_code == 0) { /* match! we will execute this branch */
7492 free(case_word); /* make future "word)" stop */
7500 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7502 continue; /* not matched yet, skip this pipe */
7505 /* Just pressing <enter> in shell should check for jobs.
7506 * OTOH, in non-interactive shell this is useless
7507 * and only leads to extra job checks */
7508 if (pi->num_cmds == 0) {
7509 if (G_interactive_fd)
7510 goto check_jobs_and_continue;
7514 /* After analyzing all keywords and conditions, we decided
7515 * to execute this pipe. NB: have to do checkjobs(NULL)
7516 * after run_pipe to collect any background children,
7517 * even if list execution is to be stopped. */
7518 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7521 #if ENABLE_HUSH_LOOPS
7522 G.flag_break_continue = 0;
7524 rcode = r = run_pipe(pi); /* NB: rcode is a smallint */
7526 /* We ran a builtin, function, or group.
7527 * rcode is already known
7528 * and we don't need to wait for anything. */
7529 G.last_exitcode = rcode;
7530 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7531 check_and_run_traps();
7532 #if ENABLE_HUSH_LOOPS
7533 /* Was it "break" or "continue"? */
7534 if (G.flag_break_continue) {
7535 smallint fbc = G.flag_break_continue;
7536 /* We might fall into outer *loop*,
7537 * don't want to break it too */
7539 G.depth_break_continue--;
7540 if (G.depth_break_continue == 0)
7541 G.flag_break_continue = 0;
7542 /* else: e.g. "continue 2" should *break* once, *then* continue */
7543 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7544 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7548 /* "continue": simulate end of loop */
7553 #if ENABLE_HUSH_FUNCTIONS
7554 if (G.flag_return_in_progress == 1) {
7559 } else if (pi->followup == PIPE_BG) {
7560 /* What does bash do with attempts to background builtins? */
7561 /* even bash 3.2 doesn't do that well with nested bg:
7562 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
7563 * I'm NOT treating inner &'s as jobs */
7564 check_and_run_traps();
7566 if (G.run_list_level == 1)
7569 /* Last command's pid goes to $! */
7570 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
7571 G.last_exitcode = rcode = EXIT_SUCCESS;
7572 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
7575 if (G.run_list_level == 1 && G_interactive_fd) {
7576 /* Waits for completion, then fg's main shell */
7577 rcode = checkjobs_and_fg_shell(pi);
7578 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
7579 check_and_run_traps();
7582 { /* This one just waits for completion */
7583 rcode = checkjobs(pi);
7584 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
7585 check_and_run_traps();
7587 G.last_exitcode = rcode;
7591 /* Analyze how result affects subsequent commands */
7593 if (rword == RES_IF || rword == RES_ELIF)
7596 check_jobs_and_continue:
7598 dont_check_jobs_but_continue: ;
7599 #if ENABLE_HUSH_LOOPS
7600 /* Beware of "while false; true; do ..."! */
7602 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
7603 /* check for RES_DONE is needed for "while ...; do \n done" case */
7605 if (rword == RES_WHILE) {
7607 /* "while false; do...done" - exitcode 0 */
7608 G.last_exitcode = rcode = EXIT_SUCCESS;
7609 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
7613 if (rword == RES_UNTIL) {
7615 debug_printf_exec(": until expr is true: breaking\n");
7626 #if ENABLE_HUSH_LOOPS
7631 #if ENABLE_HUSH_CASE
7635 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
7639 /* Select which version we will use */
7640 static int run_and_free_list(struct pipe *pi)
7643 debug_printf_exec("run_and_free_list entered\n");
7644 if (!G.o_opt[OPT_O_NOEXEC]) {
7645 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
7646 rcode = run_list(pi);
7648 /* free_pipe_list has the side effect of clearing memory.
7649 * In the long run that function can be merged with run_list,
7650 * but doing that now would hobble the debugging effort. */
7652 debug_printf_exec("run_and_free_list return %d\n", rcode);
7657 static void install_sighandlers(unsigned mask)
7659 sighandler_t old_handler;
7661 while ((mask >>= 1) != 0) {
7665 old_handler = install_sighandler(sig, pick_sighandler(sig));
7666 /* POSIX allows shell to re-enable SIGCHLD
7667 * even if it was SIG_IGN on entry.
7668 * Therefore we skip IGN check for it:
7672 if (old_handler == SIG_IGN) {
7673 /* oops... restore back to IGN, and record this fact */
7674 install_sighandler(sig, old_handler);
7676 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7678 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7683 /* Called a few times only (or even once if "sh -c") */
7684 static void install_special_sighandlers(void)
7688 /* Which signals are shell-special? */
7689 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
7690 if (G_interactive_fd) {
7691 mask |= SPECIAL_INTERACTIVE_SIGS;
7692 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
7693 mask |= SPECIAL_JOBSTOP_SIGS;
7695 /* Careful, do not re-install handlers we already installed */
7696 if (G.special_sig_mask != mask) {
7697 unsigned diff = mask & ~G.special_sig_mask;
7698 G.special_sig_mask = mask;
7699 install_sighandlers(diff);
7705 /* Set handlers to restore tty pgrp and exit */
7706 static void install_fatal_sighandlers(void)
7710 /* We will restore tty pgrp on these signals */
7712 + (1 << SIGILL ) * HUSH_DEBUG
7713 + (1 << SIGFPE ) * HUSH_DEBUG
7714 + (1 << SIGBUS ) * HUSH_DEBUG
7715 + (1 << SIGSEGV) * HUSH_DEBUG
7716 + (1 << SIGTRAP) * HUSH_DEBUG
7718 /* bash 3.2 seems to handle these just like 'fatal' ones */
7721 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
7722 * if we aren't interactive... but in this case
7723 * we never want to restore pgrp on exit, and this fn is not called
7725 /*+ (1 << SIGHUP )*/
7726 /*+ (1 << SIGTERM)*/
7727 /*+ (1 << SIGINT )*/
7729 G_fatal_sig_mask = mask;
7731 install_sighandlers(mask);
7735 static int set_mode(int state, char mode, const char *o_opt)
7740 G.o_opt[OPT_O_NOEXEC] = state;
7743 IF_HUSH_MODE_X(G_x_mode = state;)
7747 /* "set -+o" without parameter.
7748 * in bash, set -o produces this output:
7752 * We always use the second form.
7754 const char *p = o_opt_strings;
7757 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
7763 idx = index_in_strings(o_opt_strings, o_opt);
7765 G.o_opt[idx] = state;
7769 return EXIT_FAILURE;
7771 return EXIT_SUCCESS;
7774 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
7775 int hush_main(int argc, char **argv)
7778 OPT_login = (1 << 0),
7782 unsigned builtin_argc;
7784 struct variable *cur_var;
7785 struct variable *shell_ver;
7788 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
7789 G.last_exitcode = EXIT_SUCCESS;
7790 #if ENABLE_HUSH_FAST
7791 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
7794 G.argv0_for_re_execing = argv[0];
7796 /* Deal with HUSH_VERSION */
7797 shell_ver = xzalloc(sizeof(*shell_ver));
7798 shell_ver->flg_export = 1;
7799 shell_ver->flg_read_only = 1;
7800 /* Code which handles ${var<op>...} needs writable values for all variables,
7801 * therefore we xstrdup: */
7802 shell_ver->varstr = xstrdup(hush_version_str);
7803 /* Create shell local variables from the values
7804 * currently living in the environment */
7805 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
7806 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
7807 G.top_var = shell_ver;
7808 cur_var = G.top_var;
7811 char *value = strchr(*e, '=');
7812 if (value) { /* paranoia */
7813 cur_var->next = xzalloc(sizeof(*cur_var));
7814 cur_var = cur_var->next;
7815 cur_var->varstr = *e;
7816 cur_var->max_len = strlen(*e);
7817 cur_var->flg_export = 1;
7821 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
7822 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
7823 putenv(shell_ver->varstr);
7826 set_pwd_var(/*exp:*/ 1);
7828 #if ENABLE_HUSH_BASH_COMPAT
7829 /* Set (but not export) HOSTNAME unless already set */
7830 if (!get_local_var_value("HOSTNAME")) {
7833 set_local_var_from_halves("HOSTNAME", uts.nodename);
7835 /* bash also exports SHLVL and _,
7836 * and sets (but doesn't export) the following variables:
7838 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
7839 * BASH_VERSION='3.2.0(1)-release'
7841 * MACHTYPE=i386-pc-linux-gnu
7843 * PPID=<NNNNN> - we also do it elsewhere
7854 * PIPESTATUS=([0]="0")
7855 * HISTFILE=/<xxx>/.bash_history
7859 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
7861 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
7872 #if ENABLE_FEATURE_EDITING
7873 G.line_input_state = new_line_input_t(FOR_SHELL);
7876 /* Initialize some more globals to non-zero values */
7877 cmdedit_update_prompt();
7879 die_func = xfunc_has_died;
7881 /* Shell is non-interactive at first. We need to call
7882 * install_special_sighandlers() if we are going to execute "sh <script>",
7883 * "sh -c <cmds>" or login shell's /etc/profile and friends.
7884 * If we later decide that we are interactive, we run install_special_sighandlers()
7885 * in order to intercept (more) signals.
7889 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
7890 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
7893 opt = getopt(argc, argv, "+c:xinsl"
7896 # if ENABLE_HUSH_FUNCTIONS
7906 * sh ... -c 'script'
7907 * sh ... -c 'script' ARG0 [ARG1...]
7908 * On NOMMU, if builtin_argc != 0,
7909 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
7910 * "" needs to be replaced with NULL
7911 * and BARGV vector fed to builtin function.
7912 * Note: the form without ARG0 never happens:
7913 * sh ... -c 'builtin' BARGV... ""
7916 G.root_pid = getpid();
7917 G.root_ppid = getppid();
7919 G.global_argv = argv + optind;
7920 G.global_argc = argc - optind;
7922 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
7923 const struct built_in_command *x;
7925 install_special_sighandlers();
7926 x = find_builtin(optarg);
7927 if (x) { /* paranoia */
7928 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
7929 G.global_argv += builtin_argc;
7930 G.global_argv[-1] = NULL; /* replace "" */
7932 G.last_exitcode = x->b_function(argv + optind - 1);
7936 if (!G.global_argv[0]) {
7937 /* -c 'script' (no params): prevent empty $0 */
7938 G.global_argv--; /* points to argv[i] of 'script' */
7939 G.global_argv[0] = argv[0];
7941 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
7942 install_special_sighandlers();
7943 parse_and_run_string(optarg);
7946 /* Well, we cannot just declare interactiveness,
7947 * we have to have some stuff (ctty, etc) */
7948 /* G_interactive_fd++; */
7951 /* "-s" means "read from stdin", but this is how we always
7952 * operate, so simply do nothing here. */
7958 case '<': /* "big heredoc" support */
7959 full_write1_str(optarg);
7962 unsigned long long empty_trap_mask;
7964 G.root_pid = bb_strtou(optarg, &optarg, 16);
7966 G.root_ppid = bb_strtou(optarg, &optarg, 16);
7968 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
7970 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
7972 builtin_argc = bb_strtou(optarg, &optarg, 16);
7974 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
7975 if (empty_trap_mask != 0) {
7977 install_special_sighandlers();
7978 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
7979 for (sig = 1; sig < NSIG; sig++) {
7980 if (empty_trap_mask & (1LL << sig)) {
7981 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
7982 install_sighandler(sig, SIG_IGN);
7986 # if ENABLE_HUSH_LOOPS
7988 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
7994 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
7996 # if ENABLE_HUSH_FUNCTIONS
7998 struct function *funcp = new_function(optarg);
7999 /* funcp->name is already set to optarg */
8000 /* funcp->body is set to NULL. It's a special case. */
8001 funcp->body_as_string = argv[optind];
8009 if (set_mode(1, opt, NULL) == 0) /* no error */
8013 fprintf(stderr, "Usage: sh [FILE]...\n"
8014 " or: sh -c command [args]...\n\n");
8020 } /* option parsing loop */
8022 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8023 G.global_argc = argc - (optind - 1);
8024 G.global_argv = argv + (optind - 1);
8025 G.global_argv[0] = argv[0];
8028 G.root_pid = getpid();
8029 G.root_ppid = getppid();
8032 /* If we are login shell... */
8033 if (flags & OPT_login) {
8035 debug_printf("sourcing /etc/profile\n");
8036 input = fopen_for_read("/etc/profile");
8037 if (input != NULL) {
8038 close_on_exec_on(fileno(input));
8039 install_special_sighandlers();
8040 parse_and_run_file(input);
8043 /* bash: after sourcing /etc/profile,
8044 * tries to source (in the given order):
8045 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8046 * stopping on first found. --noprofile turns this off.
8047 * bash also sources ~/.bash_logout on exit.
8048 * If called as sh, skips .bash_XXX files.
8052 if (G.global_argv[1]) {
8055 * "bash <script>" (which is never interactive (unless -i?))
8056 * sources $BASH_ENV here (without scanning $PATH).
8057 * If called as sh, does the same but with $ENV.
8061 debug_printf("running script '%s'\n", G.global_argv[0]);
8062 input = xfopen_for_read(G.global_argv[0]);
8063 close_on_exec_on(fileno(input));
8064 install_special_sighandlers();
8065 parse_and_run_file(input);
8066 #if ENABLE_FEATURE_CLEAN_UP
8072 /* Up to here, shell was non-interactive. Now it may become one.
8073 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8076 /* A shell is interactive if the '-i' flag was given,
8077 * or if all of the following conditions are met:
8079 * no arguments remaining or the -s flag given
8080 * standard input is a terminal
8081 * standard output is a terminal
8082 * Refer to Posix.2, the description of the 'sh' utility.
8085 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8086 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8087 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8088 if (G_saved_tty_pgrp < 0)
8089 G_saved_tty_pgrp = 0;
8091 /* try to dup stdin to high fd#, >= 255 */
8092 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8093 if (G_interactive_fd < 0) {
8094 /* try to dup to any fd */
8095 G_interactive_fd = dup(STDIN_FILENO);
8096 if (G_interactive_fd < 0) {
8098 G_interactive_fd = 0;
8099 G_saved_tty_pgrp = 0;
8102 // TODO: track & disallow any attempts of user
8103 // to (inadvertently) close/redirect G_interactive_fd
8105 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8106 if (G_interactive_fd) {
8107 close_on_exec_on(G_interactive_fd);
8109 if (G_saved_tty_pgrp) {
8110 /* If we were run as 'hush &', sleep until we are
8111 * in the foreground (tty pgrp == our pgrp).
8112 * If we get started under a job aware app (like bash),
8113 * make sure we are now in charge so we don't fight over
8114 * who gets the foreground */
8116 pid_t shell_pgrp = getpgrp();
8117 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8118 if (G_saved_tty_pgrp == shell_pgrp)
8120 /* send TTIN to ourself (should stop us) */
8121 kill(- shell_pgrp, SIGTTIN);
8125 /* Install more signal handlers */
8126 install_special_sighandlers();
8128 if (G_saved_tty_pgrp) {
8129 /* Set other signals to restore saved_tty_pgrp */
8130 install_fatal_sighandlers();
8131 /* Put ourselves in our own process group
8132 * (bash, too, does this only if ctty is available) */
8133 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8134 /* Grab control of the terminal */
8135 tcsetpgrp(G_interactive_fd, getpid());
8137 enable_restore_tty_pgrp_on_exit();
8139 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8141 const char *hp = get_local_var_value("HISTFILE");
8143 hp = get_local_var_value("HOME");
8145 hp = concat_path_file(hp, ".hush_history");
8150 G.line_input_state->hist_file = hp;
8151 //set_local_var(xasprintf("HISTFILE=%s", ...));
8153 # if ENABLE_FEATURE_SH_HISTFILESIZE
8154 hp = get_local_var_value("HISTFILESIZE");
8155 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8160 install_special_sighandlers();
8162 #elif ENABLE_HUSH_INTERACTIVE
8163 /* No job control compiled in, only prompt/line editing */
8164 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8165 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8166 if (G_interactive_fd < 0) {
8167 /* try to dup to any fd */
8168 G_interactive_fd = dup(STDIN_FILENO);
8169 if (G_interactive_fd < 0)
8171 G_interactive_fd = 0;
8174 if (G_interactive_fd) {
8175 close_on_exec_on(G_interactive_fd);
8177 install_special_sighandlers();
8179 /* We have interactiveness code disabled */
8180 install_special_sighandlers();
8183 * if interactive but not a login shell, sources ~/.bashrc
8184 * (--norc turns this off, --rcfile <file> overrides)
8187 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8188 /* note: ash and hush share this string */
8189 printf("\n\n%s %s\n"
8190 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8193 "hush - the humble shell"
8197 parse_and_run_file(stdin);
8200 hush_exit(G.last_exitcode);
8205 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8206 int msh_main(int argc, char **argv)
8208 //bb_error_msg("msh is deprecated, please use hush instead");
8209 return hush_main(argc, argv);
8217 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8222 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8229 return applet_main_func(argc, argv - argc);
8232 static int FAST_FUNC builtin_test(char **argv)
8234 return run_applet_main(argv, test_main);
8237 static int FAST_FUNC builtin_echo(char **argv)
8239 return run_applet_main(argv, echo_main);
8243 static int FAST_FUNC builtin_printf(char **argv)
8245 return run_applet_main(argv, printf_main);
8249 static char **skip_dash_dash(char **argv)
8252 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8257 static int FAST_FUNC builtin_eval(char **argv)
8259 int rcode = EXIT_SUCCESS;
8261 argv = skip_dash_dash(argv);
8263 char *str = expand_strvec_to_string(argv);
8265 * eval "echo Hi; done" ("done" is syntax error):
8266 * "echo Hi" will not execute too.
8268 parse_and_run_string(str);
8270 rcode = G.last_exitcode;
8275 static int FAST_FUNC builtin_cd(char **argv)
8279 argv = skip_dash_dash(argv);
8281 if (newdir == NULL) {
8282 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8283 * bash says "bash: cd: HOME not set" and does nothing
8286 const char *home = get_local_var_value("HOME");
8287 newdir = home ? home : "/";
8289 if (chdir(newdir)) {
8290 /* Mimic bash message exactly */
8291 bb_perror_msg("cd: %s", newdir);
8292 return EXIT_FAILURE;
8294 /* Read current dir (get_cwd(1) is inside) and set PWD.
8295 * Note: do not enforce exporting. If PWD was unset or unexported,
8296 * set it again, but do not export. bash does the same.
8298 set_pwd_var(/*exp:*/ 0);
8299 return EXIT_SUCCESS;
8302 static int FAST_FUNC builtin_exec(char **argv)
8304 argv = skip_dash_dash(argv);
8305 if (argv[0] == NULL)
8306 return EXIT_SUCCESS; /* bash does this */
8308 /* Careful: we can end up here after [v]fork. Do not restore
8309 * tty pgrp then, only top-level shell process does that */
8310 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8311 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8313 /* TODO: if exec fails, bash does NOT exit! We do.
8314 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8315 * and tcsetpgrp, and this is inherently racy.
8317 execvp_or_die(argv);
8320 static int FAST_FUNC builtin_exit(char **argv)
8322 debug_printf_exec("%s()\n", __func__);
8324 /* interactive bash:
8325 * # trap "echo EEE" EXIT
8328 * There are stopped jobs.
8329 * (if there are _stopped_ jobs, running ones don't count)
8332 * EEE (then bash exits)
8334 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8337 /* note: EXIT trap is run by hush_exit */
8338 argv = skip_dash_dash(argv);
8339 if (argv[0] == NULL)
8340 hush_exit(G.last_exitcode);
8341 /* mimic bash: exit 123abc == exit 255 + error msg */
8342 xfunc_error_retval = 255;
8343 /* bash: exit -2 == exit 254, no error msg */
8344 hush_exit(xatoi(argv[0]) & 0xff);
8347 static void print_escaped(const char *s)
8352 const char *p = strchrnul(s, '\'');
8353 /* print 'xxxx', possibly just '' */
8354 printf("'%.*s'", (int)(p - s), s);
8359 /* s points to '; print "'''...'''" */
8361 do putchar('\''); while (*++s == '\'');
8366 #if !ENABLE_HUSH_LOCAL
8367 #define helper_export_local(argv, exp, lvl) \
8368 helper_export_local(argv, exp)
8370 static void helper_export_local(char **argv, int exp, int lvl)
8374 char *name_end = strchrnul(name, '=');
8376 /* So far we do not check that name is valid (TODO?) */
8378 if (*name_end == '\0') {
8379 struct variable *var, **vpp;
8381 vpp = get_ptr_to_local_var(name, name_end - name);
8382 var = vpp ? *vpp : NULL;
8384 if (exp == -1) { /* unexporting? */
8385 /* export -n NAME (without =VALUE) */
8387 var->flg_export = 0;
8388 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8390 } /* else: export -n NOT_EXISTING_VAR: no-op */
8393 if (exp == 1) { /* exporting? */
8394 /* export NAME (without =VALUE) */
8396 var->flg_export = 1;
8397 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8398 putenv(var->varstr);
8402 /* Exporting non-existing variable.
8403 * bash does not put it in environment,
8404 * but remembers that it is exported,
8405 * and does put it in env when it is set later.
8406 * We just set it to "" and export. */
8407 /* Or, it's "local NAME" (without =VALUE).
8408 * bash sets the value to "". */
8409 name = xasprintf("%s=", name);
8411 /* (Un)exporting/making local NAME=VALUE */
8412 name = xstrdup(name);
8414 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8418 static int FAST_FUNC builtin_export(char **argv)
8420 unsigned opt_unexport;
8422 #if ENABLE_HUSH_EXPORT_N
8423 /* "!": do not abort on errors */
8424 opt_unexport = getopt32(argv, "!n");
8425 if (opt_unexport == (uint32_t)-1)
8426 return EXIT_FAILURE;
8433 if (argv[0] == NULL) {
8440 /* ash emits: export VAR='VAL'
8441 * bash: declare -x VAR="VAL"
8442 * we follow ash example */
8443 const char *s = *e++;
8444 const char *p = strchr(s, '=');
8446 if (!p) /* wtf? take next variable */
8449 printf("export %.*s", (int)(p - s) + 1, s);
8450 print_escaped(p + 1);
8454 /*fflush_all(); - done after each builtin anyway */
8456 return EXIT_SUCCESS;
8459 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8461 return EXIT_SUCCESS;
8464 #if ENABLE_HUSH_LOCAL
8465 static int FAST_FUNC builtin_local(char **argv)
8467 if (G.func_nest_level == 0) {
8468 bb_error_msg("%s: not in a function", argv[0]);
8469 return EXIT_FAILURE; /* bash compat */
8471 helper_export_local(argv, 0, G.func_nest_level);
8472 return EXIT_SUCCESS;
8476 static int FAST_FUNC builtin_trap(char **argv)
8482 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8487 /* No args: print all trapped */
8488 for (i = 0; i < NSIG; ++i) {
8491 print_escaped(G.traps[i]);
8492 /* note: bash adds "SIG", but only if invoked
8493 * as "bash". If called as "sh", or if set -o posix,
8494 * then it prints short signal names.
8495 * We are printing short names: */
8496 printf(" %s\n", get_signame(i));
8499 /*fflush_all(); - done after each builtin anyway */
8500 return EXIT_SUCCESS;
8504 /* If first arg is a number: reset all specified signals */
8505 sig = bb_strtou(*argv, NULL, 10);
8511 sighandler_t handler;
8513 sig = get_signum(*argv++);
8514 if (sig < 0 || sig >= NSIG) {
8516 /* Mimic bash message exactly */
8517 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
8522 G.traps[sig] = xstrdup(new_cmd);
8524 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
8525 get_signame(sig), sig, G.traps[sig]);
8527 /* There is no signal for 0 (EXIT) */
8532 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
8534 /* We are removing trap handler */
8535 handler = pick_sighandler(sig);
8536 install_sighandler(sig, handler);
8541 if (!argv[1]) { /* no second arg */
8542 bb_error_msg("trap: invalid arguments");
8543 return EXIT_FAILURE;
8546 /* First arg is "-": reset all specified to default */
8547 /* First arg is "--": skip it, the rest is "handler SIGs..." */
8548 /* Everything else: set arg as signal handler
8549 * (includes "" case, which ignores signal) */
8550 if (argv[0][0] == '-') {
8551 if (argv[0][1] == '\0') { /* "-" */
8552 /* new_cmd remains NULL: "reset these sigs" */
8555 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
8558 /* else: "-something", no special meaning */
8563 goto process_sig_list;
8566 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
8567 static int FAST_FUNC builtin_type(char **argv)
8569 int ret = EXIT_SUCCESS;
8575 if (0) {} /* make conditional compile easier below */
8576 /*else if (find_alias(*argv))
8577 type = "an alias";*/
8578 #if ENABLE_HUSH_FUNCTIONS
8579 else if (find_function(*argv))
8580 type = "a function";
8582 else if (find_builtin(*argv))
8583 type = "a shell builtin";
8584 else if ((path = find_in_path(*argv)) != NULL)
8587 bb_error_msg("type: %s: not found", *argv);
8592 printf("%s is %s\n", *argv, type);
8600 /* built-in 'fg' and 'bg' handler */
8601 static int FAST_FUNC builtin_fg_bg(char **argv)
8606 if (!G_interactive_fd)
8607 return EXIT_FAILURE;
8609 /* If they gave us no args, assume they want the last backgrounded task */
8611 for (pi = G.job_list; pi; pi = pi->next) {
8612 if (pi->jobid == G.last_jobid) {
8616 bb_error_msg("%s: no current job", argv[0]);
8617 return EXIT_FAILURE;
8619 if (sscanf(argv[1], "%%%d", &jobnum) != 1) {
8620 bb_error_msg("%s: bad argument '%s'", argv[0], argv[1]);
8621 return EXIT_FAILURE;
8623 for (pi = G.job_list; pi; pi = pi->next) {
8624 if (pi->jobid == jobnum) {
8628 bb_error_msg("%s: %d: no such job", argv[0], jobnum);
8629 return EXIT_FAILURE;
8631 /* TODO: bash prints a string representation
8632 * of job being foregrounded (like "sleep 1 | cat") */
8633 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
8634 /* Put the job into the foreground. */
8635 tcsetpgrp(G_interactive_fd, pi->pgrp);
8638 /* Restart the processes in the job */
8639 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
8640 for (i = 0; i < pi->num_cmds; i++) {
8641 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
8643 pi->stopped_cmds = 0;
8645 i = kill(- pi->pgrp, SIGCONT);
8647 if (errno == ESRCH) {
8648 delete_finished_bg_job(pi);
8649 return EXIT_SUCCESS;
8651 bb_perror_msg("kill (SIGCONT)");
8654 if (argv[0][0] == 'f') {
8656 return checkjobs_and_fg_shell(pi);
8658 return EXIT_SUCCESS;
8662 #if ENABLE_HUSH_HELP
8663 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
8665 const struct built_in_command *x;
8668 "Built-in commands:\n"
8669 "------------------\n");
8670 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
8672 printf("%-10s%s\n", x->b_cmd, x->b_descr);
8675 return EXIT_SUCCESS;
8679 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
8680 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
8682 show_history(G.line_input_state);
8683 return EXIT_SUCCESS;
8688 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
8691 const char *status_string;
8693 for (job = G.job_list; job; job = job->next) {
8694 if (job->alive_cmds == job->stopped_cmds)
8695 status_string = "Stopped";
8697 status_string = "Running";
8699 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
8701 return EXIT_SUCCESS;
8706 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
8711 # ifdef M_TRIM_THRESHOLD
8712 /* Optional. Reduces probability of false positives */
8715 /* Crude attempt to find where "free memory" starts,
8716 * sans fragmentation. */
8718 l = (unsigned long)p;
8721 if (l < (unsigned long)p) l = (unsigned long)p;
8724 if (!G.memleak_value)
8725 G.memleak_value = l;
8727 l -= G.memleak_value;
8734 /* Exitcode is "how many kilobytes we leaked since 1st call" */
8739 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
8742 return EXIT_SUCCESS;
8745 /* Interruptibility of read builtin in bash
8746 * (tested on bash-4.2.8 by sending signals (not by ^C)):
8748 * Empty trap makes read ignore corresponding signal, for any signal.
8751 * - terminates non-interactive shell;
8752 * - interrupts read in interactive shell;
8753 * if it has non-empty trap:
8754 * - executes trap and returns to command prompt in interactive shell;
8755 * - executes trap and returns to read in non-interactive shell;
8757 * - is ignored (does not interrupt) read in interactive shell;
8758 * - terminates non-interactive shell;
8759 * if it has non-empty trap:
8760 * - executes trap and returns to read;
8762 * - terminates shell (regardless of interactivity);
8763 * if it has non-empty trap:
8764 * - executes trap and returns to read;
8766 static int FAST_FUNC builtin_read(char **argv)
8776 /* "!": do not abort on errors.
8777 * Option string must start with "sr" to match BUILTIN_READ_xxx
8779 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
8780 if (read_flags == (uint32_t)-1)
8781 return EXIT_FAILURE;
8783 ifs = get_local_var_value("IFS"); /* can be NULL */
8786 r = shell_builtin_read(set_local_var_from_halves,
8796 if ((uintptr_t)r == 1 && errno == EINTR) {
8797 unsigned sig = check_and_run_traps();
8798 if (sig && sig != SIGINT)
8802 if ((uintptr_t)r > 1) {
8803 bb_error_msg("%s", r);
8804 r = (char*)(uintptr_t)1;
8807 return (uintptr_t)r;
8810 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8811 * built-in 'set' handler
8813 * set [-abCefhmnuvx] [-o option] [argument...]
8814 * set [+abCefhmnuvx] [+o option] [argument...]
8815 * set -- [argument...]
8818 * Implementations shall support the options in both their hyphen and
8819 * plus-sign forms. These options can also be specified as options to sh.
8821 * Write out all variables and their values: set
8822 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8823 * Turn on the -x and -v options: set -xv
8824 * Unset all positional parameters: set --
8825 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8826 * Set the positional parameters to the expansion of x, even if x expands
8827 * with a leading '-' or '+': set -- $x
8829 * So far, we only support "set -- [argument...]" and some of the short names.
8831 static int FAST_FUNC builtin_set(char **argv)
8834 char **pp, **g_argv;
8835 char *arg = *++argv;
8839 for (e = G.top_var; e; e = e->next)
8841 return EXIT_SUCCESS;
8845 if (strcmp(arg, "--") == 0) {
8849 if (arg[0] != '+' && arg[0] != '-')
8851 for (n = 1; arg[n]; ++n) {
8852 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
8854 if (arg[n] == 'o' && argv[1])
8857 } while ((arg = *++argv) != NULL);
8858 /* Now argv[0] is 1st argument */
8861 return EXIT_SUCCESS;
8864 /* NB: G.global_argv[0] ($0) is never freed/changed */
8865 g_argv = G.global_argv;
8866 if (G.global_args_malloced) {
8872 G.global_args_malloced = 1;
8873 pp = xzalloc(sizeof(pp[0]) * 2);
8874 pp[0] = g_argv[0]; /* retain $0 */
8877 /* This realloc's G.global_argv */
8878 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
8885 return EXIT_SUCCESS;
8887 /* Nothing known, so abort */
8889 bb_error_msg("set: %s: invalid option", arg);
8890 return EXIT_FAILURE;
8893 static int FAST_FUNC builtin_shift(char **argv)
8896 argv = skip_dash_dash(argv);
8900 if (n >= 0 && n < G.global_argc) {
8901 if (G.global_args_malloced) {
8904 free(G.global_argv[m++]);
8907 memmove(&G.global_argv[1], &G.global_argv[n+1],
8908 G.global_argc * sizeof(G.global_argv[0]));
8909 return EXIT_SUCCESS;
8911 return EXIT_FAILURE;
8914 static int FAST_FUNC builtin_source(char **argv)
8916 char *arg_path, *filename;
8919 #if ENABLE_HUSH_FUNCTIONS
8923 argv = skip_dash_dash(argv);
8926 /* bash says: "bash: .: filename argument required" */
8927 return 2; /* bash compat */
8930 if (!strchr(filename, '/')) {
8931 arg_path = find_in_path(filename);
8933 filename = arg_path;
8935 input = fopen_or_warn(filename, "r");
8938 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
8939 /* POSIX: non-interactive shell should abort here,
8940 * not merely fail. So far no one complained :)
8942 return EXIT_FAILURE;
8944 close_on_exec_on(fileno(input));
8946 #if ENABLE_HUSH_FUNCTIONS
8947 sv_flg = G.flag_return_in_progress;
8948 /* "we are inside sourced file, ok to use return" */
8949 G.flag_return_in_progress = -1;
8952 save_and_replace_G_args(&sv, argv);
8954 parse_and_run_file(input);
8958 restore_G_args(&sv, argv);
8959 #if ENABLE_HUSH_FUNCTIONS
8960 G.flag_return_in_progress = sv_flg;
8963 return G.last_exitcode;
8966 static int FAST_FUNC builtin_umask(char **argv)
8973 argv = skip_dash_dash(argv);
8975 mode_t old_mask = mask;
8977 /* numeric umasks are taken as-is */
8978 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
8979 if (!isdigit(argv[0][0]))
8981 mask = bb_parse_mode(argv[0], mask);
8982 if (!isdigit(argv[0][0]))
8984 if ((unsigned)mask > 0777) {
8987 * bash: umask: 'q': invalid symbolic mode operator
8988 * bash: umask: 999: octal number out of range
8990 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
8995 printf("%04o\n", (unsigned) mask);
8996 /* fall through and restore mask which we set to 0 */
9000 return !rc; /* rc != 0 - success */
9003 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
9004 static int FAST_FUNC builtin_unset(char **argv)
9009 /* "!": do not abort on errors */
9010 /* "+": stop at 1st non-option */
9011 opts = getopt32(argv, "!+vf");
9012 if (opts == (unsigned)-1)
9013 return EXIT_FAILURE;
9015 bb_error_msg("unset: -v and -f are exclusive");
9016 return EXIT_FAILURE;
9022 if (!(opts & 2)) { /* not -f */
9023 if (unset_local_var(*argv)) {
9024 /* unset <nonexistent_var> doesn't fail.
9025 * Error is when one tries to unset RO var.
9026 * Message was printed by unset_local_var. */
9030 #if ENABLE_HUSH_FUNCTIONS
9040 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9041 static int FAST_FUNC builtin_wait(char **argv)
9043 int ret = EXIT_SUCCESS;
9046 argv = skip_dash_dash(argv);
9047 if (argv[0] == NULL) {
9048 /* Don't care about wait results */
9049 /* Note 1: must wait until there are no more children */
9050 /* Note 2: must be interruptible */
9052 * $ sleep 3 & sleep 6 & wait
9057 * $ sleep 3 & sleep 6 & wait
9061 * ^C <-- after ~4 sec from keyboard
9066 sigset_t oldset, allsigs;
9068 /* waitpid is not interruptible by SA_RESTARTed
9069 * signals which we use. Thus, this ugly dance:
9072 /* Make sure possible SIGCHLD is stored in kernel's
9073 * pending signal mask before we call waitpid.
9074 * Or else we may race with SIGCHLD, lose it,
9075 * and get stuck in sigwaitinfo...
9077 sigfillset(&allsigs);
9078 sigprocmask(SIG_SETMASK, &allsigs, &oldset);
9080 if (!sigisemptyset(&G.pending_set)) {
9081 /* Crap! we raced with some signal! */
9086 checkjobs(NULL); /* waitpid(WNOHANG) inside */
9087 if (errno == ECHILD) {
9088 sigprocmask(SIG_SETMASK, &oldset, NULL);
9092 /* Wait for SIGCHLD or any other signal */
9093 //sig = sigwaitinfo(&allsigs, NULL);
9094 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9095 /* Note: sigsuspend invokes signal handler */
9096 sigsuspend(&oldset);
9098 sigprocmask(SIG_SETMASK, &oldset, NULL);
9100 /* So, did we get a signal? */
9102 // raise(sig); /* run handler */
9103 sig = check_and_run_traps();
9104 if (sig /*&& sig != SIGCHLD - always true */) {
9109 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9114 /* This is probably buggy wrt interruptible-ness */
9116 pid_t pid = bb_strtou(*argv, NULL, 10);
9118 /* mimic bash message */
9119 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9120 return EXIT_FAILURE;
9122 if (waitpid(pid, &status, 0) == pid) {
9123 if (WIFSIGNALED(status))
9124 ret = 128 + WTERMSIG(status);
9125 else if (WIFEXITED(status))
9126 ret = WEXITSTATUS(status);
9130 bb_perror_msg("wait %s", *argv);
9139 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9140 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9143 def = bb_strtou(argv[1], NULL, 10);
9144 if (errno || def < def_min || argv[2]) {
9145 bb_error_msg("%s: bad arguments", argv[0]);
9153 #if ENABLE_HUSH_LOOPS
9154 static int FAST_FUNC builtin_break(char **argv)
9157 if (G.depth_of_loop == 0) {
9158 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9159 return EXIT_SUCCESS; /* bash compat */
9161 G.flag_break_continue++; /* BC_BREAK = 1 */
9163 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9164 if (depth == UINT_MAX)
9165 G.flag_break_continue = BC_BREAK;
9166 if (G.depth_of_loop < depth)
9167 G.depth_break_continue = G.depth_of_loop;
9169 return EXIT_SUCCESS;
9172 static int FAST_FUNC builtin_continue(char **argv)
9174 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9175 return builtin_break(argv);
9179 #if ENABLE_HUSH_FUNCTIONS
9180 static int FAST_FUNC builtin_return(char **argv)
9184 if (G.flag_return_in_progress != -1) {
9185 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9186 return EXIT_FAILURE; /* bash compat */
9189 G.flag_return_in_progress = 1;
9192 * out of range: wraps around at 256, does not error out
9193 * non-numeric param:
9194 * f() { false; return qwe; }; f; echo $?
9195 * bash: return: qwe: numeric argument required <== we do this
9196 * 255 <== we also do this
9198 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);