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)
48 * follow IFS rules more precisely, including update semantics
49 * builtins mandated by standards we don't support:
50 * [un]alias, command, fc, getopts, newgrp, readonly, times
51 * make complex ${var%...} constructs support optional
52 * make here documents optional
55 * redirection of stdout+stderr: &> and >&
56 * reserved words: function select
57 * advanced test: [[ ]]
58 * process substitution: <(list) and >(list)
61 * Each EXPR is an arithmetic expression (ARITHMETIC EVALUATION)
62 * If the last arg evaluates to 0, let returns 1; 0 otherwise.
63 * NB: let `echo 'a=a + 1'` - error (IOW: multi-word expansion is used)
65 * The EXPR is evaluated according to ARITHMETIC EVALUATION.
66 * This is exactly equivalent to let "EXPR".
67 * $[EXPR]: synonym for $((EXPR))
70 * In bash, export builtin is special, its arguments are assignments
71 * and therefore expansion of them should be "one-word" expansion:
72 * $ export i=`echo 'a b'` # export has one arg: "i=a b"
74 * $ ls i=`echo 'a b'` # ls has two args: "i=a" and "b"
75 * ls: cannot access i=a: No such file or directory
76 * ls: cannot access b: No such file or directory
77 * Note1: same applies to local builtin.
78 * Note2: bash 3.2.33(1) does this only if export word itself
80 * $ export i=`echo 'aaa bbb'`; echo "$i"
82 * $ "export" i=`echo 'aaa bbb'`; echo "$i"
89 //config: hush is a small shell (25k). It handles the normal flow control
90 //config: constructs such as if/then/elif/else/fi, for/in/do/done, while loops,
91 //config: case/esac. Redirections, here documents, $((arithmetic))
92 //config: and functions are supported.
94 //config: It will compile and work on no-mmu systems.
96 //config: It does not handle select, aliases, tilde expansion,
97 //config: &>file and >&file redirection of stdout+stderr.
99 //config:config HUSH_BASH_COMPAT
100 //config: bool "bash-compatible extensions"
102 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
104 //config: Enable bash-compatible extensions.
106 //config:config HUSH_BRACE_EXPANSION
107 //config: bool "Brace expansion"
109 //config: depends on HUSH_BASH_COMPAT
111 //config: Enable {abc,def} extension.
113 //config:config HUSH_HELP
114 //config: bool "help builtin"
116 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
118 //config: Enable help builtin in hush. Code size + ~1 kbyte.
120 //config:config HUSH_INTERACTIVE
121 //config: bool "Interactive mode"
123 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
125 //config: Enable interactive mode (prompt and command editing).
126 //config: Without this, hush simply reads and executes commands
127 //config: from stdin just like a shell script from a file.
128 //config: No prompt, no PS1/PS2 magic shell variables.
130 //config:config HUSH_SAVEHISTORY
131 //config: bool "Save command history to .hush_history"
133 //config: depends on HUSH_INTERACTIVE && FEATURE_EDITING_SAVEHISTORY
135 //config: Enable history saving in hush.
137 //config:config HUSH_JOB
138 //config: bool "Job control"
140 //config: depends on HUSH_INTERACTIVE
142 //config: Enable job control: Ctrl-Z backgrounds, Ctrl-C interrupts current
143 //config: command (not entire shell), fg/bg builtins work. Without this option,
144 //config: "cmd &" still works by simply spawning a process and immediately
145 //config: prompting for next command (or executing next command in a script),
146 //config: but no separate process group is formed.
148 //config:config HUSH_TICK
149 //config: bool "Process substitution"
151 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
153 //config: Enable process substitution `command` and $(command) in hush.
155 //config:config HUSH_IF
156 //config: bool "Support if/then/elif/else/fi"
158 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
160 //config: Enable if/then/elif/else/fi in hush.
162 //config:config HUSH_LOOPS
163 //config: bool "Support for, while and until loops"
165 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
167 //config: Enable for, while and until loops in hush.
169 //config:config HUSH_CASE
170 //config: bool "Support case ... esac statement"
172 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
174 //config: Enable case ... esac statement in hush. +400 bytes.
176 //config:config HUSH_FUNCTIONS
177 //config: bool "Support funcname() { commands; } syntax"
179 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
181 //config: Enable support for shell functions in hush. +800 bytes.
183 //config:config HUSH_LOCAL
184 //config: bool "Support local builtin"
186 //config: depends on HUSH_FUNCTIONS
188 //config: Enable support for local variables in functions.
190 //config:config HUSH_RANDOM_SUPPORT
191 //config: bool "Pseudorandom generator and $RANDOM variable"
193 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
195 //config: Enable pseudorandom generator and dynamic variable "$RANDOM".
196 //config: Each read of "$RANDOM" will generate a new pseudorandom value.
198 //config:config HUSH_EXPORT_N
199 //config: bool "Support 'export -n' option"
201 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
203 //config: export -n unexports variables. It is a bash extension.
205 //config:config HUSH_MODE_X
206 //config: bool "Support 'hush -x' option and 'set -x' command"
208 //config: depends on HUSH || SH_IS_HUSH || BASH_IS_HUSH
210 //config: This instructs hush to print commands before execution.
211 //config: Adds ~300 bytes.
214 //config: bool "msh (deprecated: aliased to hush)"
216 //config: select HUSH
218 //config: msh is deprecated and will be removed, please migrate to hush.
220 //applet:IF_HUSH(APPLET(hush, BB_DIR_BIN, BB_SUID_DROP))
221 //applet:IF_MSH(APPLET_ODDNAME(msh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
222 //applet:IF_SH_IS_HUSH(APPLET_ODDNAME(sh, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
223 //applet:IF_BASH_IS_HUSH(APPLET_ODDNAME(bash, hush, BB_DIR_BIN, BB_SUID_DROP, hush))
225 //kbuild:lib-$(CONFIG_HUSH) += hush.o match.o shell_common.o
226 //kbuild:lib-$(CONFIG_SH_IS_HUSH) += hush.o match.o shell_common.o
227 //kbuild:lib-$(CONFIG_BASH_IS_HUSH) += hush.o match.o shell_common.o
228 //kbuild:lib-$(CONFIG_HUSH_RANDOM_SUPPORT) += random.o
230 /* -i (interactive) and -s (read stdin) are also accepted,
231 * but currently do nothing, therefore aren't shown in help.
232 * NOMMU-specific options are not meant to be used by users,
233 * therefore we don't show them either.
235 //usage:#define hush_trivial_usage
236 //usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
237 //usage:#define hush_full_usage "\n\n"
238 //usage: "Unix shell interpreter"
240 #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
241 || defined(__APPLE__) \
243 # include <malloc.h> /* for malloc_trim */
246 /* #include <dmalloc.h> */
248 # include <fnmatch.h>
250 #include <sys/utsname.h> /* for setting $HOSTNAME */
252 #include "busybox.h" /* for APPLET_IS_NOFORK/NOEXEC */
254 #include "shell_common.h"
257 #if ENABLE_HUSH_RANDOM_SUPPORT
260 # define CLEAR_RANDOM_T(rnd) ((void)0)
262 #ifndef F_DUPFD_CLOEXEC
263 # define F_DUPFD_CLOEXEC F_DUPFD
266 # define PIPE_BUF 4096 /* amount of buffering in a pipe */
271 #define LEAK_HUNTING 0
272 #define BUILD_AS_NOMMU 0
273 /* Enable/disable sanity checks. Ok to enable in production,
274 * only adds a bit of bloat. Set to >1 to get non-production level verbosity.
275 * Keeping 1 for now even in released versions.
278 /* Slightly bigger (+200 bytes), but faster hush.
279 * So far it only enables a trick with counting SIGCHLDs and forks,
280 * which allows us to do fewer waitpid's.
281 * (we can detect a case where neither forks were done nor SIGCHLDs happened
282 * and therefore waitpid will return the same result as last time)
284 #define ENABLE_HUSH_FAST 0
285 /* TODO: implement simplified code for users which do not need ${var%...} ops
286 * So far ${var%...} ops are always enabled:
288 #define ENABLE_HUSH_DOLLAR_OPS 1
293 # undef USE_FOR_NOMMU
296 # define USE_FOR_NOMMU(...) __VA_ARGS__
297 # define USE_FOR_MMU(...)
300 #include "NUM_APPLETS.h"
302 /* STANDALONE does not make sense, and won't compile */
303 # undef CONFIG_FEATURE_SH_STANDALONE
304 # undef ENABLE_FEATURE_SH_STANDALONE
305 # undef IF_FEATURE_SH_STANDALONE
306 # undef IF_NOT_FEATURE_SH_STANDALONE
307 # define ENABLE_FEATURE_SH_STANDALONE 0
308 # define IF_FEATURE_SH_STANDALONE(...)
309 # define IF_NOT_FEATURE_SH_STANDALONE(...) __VA_ARGS__
312 #if !ENABLE_HUSH_INTERACTIVE
313 # undef ENABLE_FEATURE_EDITING
314 # define ENABLE_FEATURE_EDITING 0
315 # undef ENABLE_FEATURE_EDITING_FANCY_PROMPT
316 # define ENABLE_FEATURE_EDITING_FANCY_PROMPT 0
317 # undef ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
318 # define ENABLE_FEATURE_EDITING_SAVE_ON_EXIT 0
321 /* Do we support ANY keywords? */
322 #if ENABLE_HUSH_IF || ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
323 # define HAS_KEYWORDS 1
324 # define IF_HAS_KEYWORDS(...) __VA_ARGS__
325 # define IF_HAS_NO_KEYWORDS(...)
327 # define HAS_KEYWORDS 0
328 # define IF_HAS_KEYWORDS(...)
329 # define IF_HAS_NO_KEYWORDS(...) __VA_ARGS__
332 /* If you comment out one of these below, it will be #defined later
333 * to perform debug printfs to stderr: */
334 #define debug_printf(...) do {} while (0)
335 /* Finer-grained debug switches */
336 #define debug_printf_parse(...) do {} while (0)
337 #define debug_print_tree(a, b) do {} while (0)
338 #define debug_printf_exec(...) do {} while (0)
339 #define debug_printf_env(...) do {} while (0)
340 #define debug_printf_jobs(...) do {} while (0)
341 #define debug_printf_expand(...) do {} while (0)
342 #define debug_printf_varexp(...) do {} while (0)
343 #define debug_printf_glob(...) do {} while (0)
344 #define debug_printf_list(...) do {} while (0)
345 #define debug_printf_subst(...) do {} while (0)
346 #define debug_printf_clean(...) do {} while (0)
348 #define ERR_PTR ((void*)(long)1)
350 #define JOB_STATUS_FORMAT "[%d] %-22s %.40s\n"
352 #define _SPECIAL_VARS_STR "_*@$!?#"
353 #define SPECIAL_VARS_STR ("_*@$!?#" + 1)
354 #define NUMERIC_SPECVARS_STR ("_*@$!?#" + 3)
355 #if ENABLE_HUSH_BASH_COMPAT
356 /* Support / and // replace ops */
357 /* Note that // is stored as \ in "encoded" string representation */
358 # define VAR_ENCODED_SUBST_OPS "\\/%#:-=+?"
359 # define VAR_SUBST_OPS ("\\/%#:-=+?" + 1)
360 # define MINUS_PLUS_EQUAL_QUESTION ("\\/%#:-=+?" + 5)
362 # define VAR_ENCODED_SUBST_OPS "%#:-=+?"
363 # define VAR_SUBST_OPS "%#:-=+?"
364 # define MINUS_PLUS_EQUAL_QUESTION ("%#:-=+?" + 3)
367 #define SPECIAL_VAR_SYMBOL 3
371 static const char hush_version_str[] ALIGN1 = "HUSH_VERSION="BB_VER;
373 /* This supports saving pointers malloced in vfork child,
374 * to be freed in the parent.
377 typedef struct nommu_save_t {
379 struct variable *old_vars;
381 char **argv_from_re_execing;
394 #if ENABLE_HUSH_LOOPS
401 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
406 /* three pseudo-keywords support contrived "case" syntax: */
407 RES_CASE_IN, /* "case ... IN", turns into RES_MATCH when IN is observed */
408 RES_MATCH , /* "word)" */
409 RES_CASE_BODY, /* "this command is inside CASE" */
416 typedef struct o_string {
418 int length; /* position where data is appended */
421 /* At least some part of the string was inside '' or "",
422 * possibly empty one: word"", wo''rd etc. */
423 smallint has_quoted_part;
424 smallint has_empty_slot;
425 smallint o_assignment; /* 0:maybe, 1:yes, 2:no */
428 EXP_FLAG_SINGLEWORD = 0x80, /* must be 0x80 */
430 /* Protect newly added chars against globbing
431 * by prepending \ to *, ?, [, \ */
432 EXP_FLAG_ESC_GLOB_CHARS = 0x1,
435 MAYBE_ASSIGNMENT = 0,
436 DEFINITELY_ASSIGNMENT = 1,
438 /* Not an assignment, but next word may be: "if v=xyz cmd;" */
441 /* Used for initialization: o_string foo = NULL_O_STRING; */
442 #define NULL_O_STRING { NULL }
444 #ifndef debug_printf_parse
445 static const char *const assignment_flag[] = {
447 "DEFINITELY_ASSIGNMENT",
453 typedef struct in_str {
455 #if ENABLE_HUSH_INTERACTIVE
456 smallint promptmode; /* 0: PS1, 1: PS2 */
463 /* The descrip member of this structure is only used to make
464 * debugging output pretty */
465 static const struct {
467 signed char default_fd;
470 { O_RDONLY, 0, "<" },
471 { O_CREAT|O_TRUNC|O_WRONLY, 1, ">" },
472 { O_CREAT|O_APPEND|O_WRONLY, 1, ">>" },
473 { O_CREAT|O_RDWR, 1, "<>" },
474 { O_RDONLY, 0, "<<" },
475 /* Should not be needed. Bogus default_fd helps in debugging */
476 /* { O_RDONLY, 77, "<<" }, */
479 struct redir_struct {
480 struct redir_struct *next;
481 char *rd_filename; /* filename */
482 int rd_fd; /* fd to redirect */
483 /* fd to redirect to, or -3 if rd_fd is to be closed (n>&-) */
485 smallint rd_type; /* (enum redir_type) */
486 /* note: for heredocs, rd_filename contains heredoc delimiter,
487 * and subsequently heredoc itself; and rd_dup is a bitmask:
488 * bit 0: do we need to trim leading tabs?
489 * bit 1: is heredoc quoted (<<'delim' syntax) ?
492 typedef enum redir_type {
494 REDIRECT_OVERWRITE = 1,
497 REDIRECT_HEREDOC = 4,
498 REDIRECT_HEREDOC2 = 5, /* REDIRECT_HEREDOC after heredoc is loaded */
501 REDIRFD_SYNTAX_ERR = -2,
502 REDIRFD_TO_FILE = -1,
503 /* otherwise, rd_fd is redirected to rd_dup */
505 HEREDOC_SKIPTABS = 1,
511 pid_t pid; /* 0 if exited */
512 int assignment_cnt; /* how many argv[i] are assignments? */
513 smallint cmd_type; /* CMD_xxx */
515 #define CMD_SUBSHELL 1
516 #if ENABLE_HUSH_BASH_COMPAT
517 /* used for "[[ EXPR ]]" */
518 # define CMD_SINGLEWORD_NOGLOB 2
520 #if ENABLE_HUSH_FUNCTIONS
521 # define CMD_FUNCDEF 3
524 smalluint cmd_exitcode;
525 /* if non-NULL, this "command" is { list }, ( list ), or a compound statement */
528 char *group_as_string;
530 #if ENABLE_HUSH_FUNCTIONS
531 struct function *child_func;
532 /* This field is used to prevent a bug here:
533 * while...do f1() {a;}; f1; f1() {b;}; f1; done
534 * When we execute "f1() {a;}" cmd, we create new function and clear
535 * cmd->group, cmd->group_as_string, cmd->argv[0].
536 * When we execute "f1() {b;}", we notice that f1 exists,
537 * and that its "parent cmd" struct is still "alive",
538 * we put those fields back into cmd->xxx
539 * (struct function has ->parent_cmd ptr to facilitate that).
540 * When we loop back, we can execute "f1() {a;}" again and set f1 correctly.
541 * Without this trick, loop would execute a;b;b;b;...
542 * instead of correct sequence a;b;a;b;...
543 * When command is freed, it severs the link
544 * (sets ->child_func->parent_cmd to NULL).
547 char **argv; /* command name and arguments */
548 /* argv vector may contain variable references (^Cvar^C, ^C0^C etc)
549 * and on execution these are substituted with their values.
550 * Substitution can make _several_ words out of one argv[n]!
551 * Example: argv[0]=='.^C*^C.' here: echo .$*.
552 * References of the form ^C`cmd arg^C are `cmd arg` substitutions.
554 struct redir_struct *redirects; /* I/O redirections */
556 /* Is there anything in this command at all? */
557 #define IS_NULL_CMD(cmd) \
558 (!(cmd)->group && !(cmd)->argv && !(cmd)->redirects)
562 int num_cmds; /* total number of commands in pipe */
563 int alive_cmds; /* number of commands running (not exited) */
564 int stopped_cmds; /* number of commands alive, but stopped */
566 int jobid; /* job number */
567 pid_t pgrp; /* process group ID for the job */
568 char *cmdtext; /* name of job */
570 struct command *cmds; /* array of commands in pipe */
571 smallint followup; /* PIPE_BG, PIPE_SEQ, PIPE_OR, PIPE_AND */
572 IF_HAS_KEYWORDS(smallint pi_inverted;) /* "! cmd | cmd" */
573 IF_HAS_KEYWORDS(smallint res_word;) /* needed for if, for, while, until... */
575 typedef enum pipe_style {
581 /* Is there anything in this pipe at all? */
582 #define IS_NULL_PIPE(pi) \
583 ((pi)->num_cmds == 0 IF_HAS_KEYWORDS( && (pi)->res_word == RES_NONE))
585 /* This holds pointers to the various results of parsing */
586 struct parse_context {
587 /* linked list of pipes */
588 struct pipe *list_head;
589 /* last pipe (being constructed right now) */
591 /* last command in pipe (being constructed right now) */
592 struct command *command;
593 /* last redirect in command->redirects list */
594 struct redir_struct *pending_redirect;
600 smallint ctx_inverted; /* "! cmd | cmd" */
602 smallint ctx_dsemicolon; /* ";;" seen */
604 /* bitmask of FLAG_xxx, for figuring out valid reserved words */
606 /* group we are enclosed in:
607 * example: "if pipe1; pipe2; then pipe3; fi"
608 * when we see "if" or "then", we malloc and copy current context,
609 * and make ->stack point to it. then we parse pipeN.
610 * when closing "then" / fi" / whatever is found,
611 * we move list_head into ->stack->command->group,
612 * copy ->stack into current context, and delete ->stack.
613 * (parsing of { list } and ( list ) doesn't use this method)
615 struct parse_context *stack;
619 /* On program start, environ points to initial environment.
620 * putenv adds new pointers into it, unsetenv removes them.
621 * Neither of these (de)allocates the strings.
622 * setenv allocates new strings in malloc space and does putenv,
623 * and thus setenv is unusable (leaky) for shell's purposes */
624 #define setenv(...) setenv_is_leaky_dont_use()
626 struct variable *next;
627 char *varstr; /* points to "name=" portion */
628 #if ENABLE_HUSH_LOCAL
629 unsigned func_nest_level;
631 int max_len; /* if > 0, name is part of initial env; else name is malloced */
632 smallint flg_export; /* putenv should be done on this var */
633 smallint flg_read_only;
641 #if ENABLE_HUSH_FUNCTIONS
643 struct function *next;
645 struct command *parent_cmd;
648 char *body_as_string;
654 /* set -/+o OPT support. (TODO: make it optional)
655 * bash supports the following opts:
666 * interactive-comments on
684 static const char o_opt_strings[] ALIGN1 =
687 #if ENABLE_HUSH_MODE_X
694 #if ENABLE_HUSH_MODE_X
702 struct FILE_list *next;
708 /* "Globals" within this file */
709 /* Sorted roughly by size (smaller offsets == smaller code) */
711 /* interactive_fd != 0 means we are an interactive shell.
712 * If we are, then saved_tty_pgrp can also be != 0, meaning
713 * that controlling tty is available. With saved_tty_pgrp == 0,
714 * job control still works, but terminal signals
715 * (^C, ^Z, ^Y, ^\) won't work at all, and background
716 * process groups can only be created with "cmd &".
717 * With saved_tty_pgrp != 0, hush will use tcsetpgrp()
718 * to give tty to the foreground process group,
719 * and will take it back when the group is stopped (^Z)
722 #if ENABLE_HUSH_INTERACTIVE
723 /* 'interactive_fd' is a fd# open to ctty, if we have one
724 * _AND_ if we decided to act interactively */
728 # define G_interactive_fd (G.interactive_fd)
730 # define G_interactive_fd 0
732 #if ENABLE_FEATURE_EDITING
733 line_input_t *line_input_state;
738 #if ENABLE_HUSH_RANDOM_SUPPORT
744 pid_t saved_tty_pgrp;
745 struct pipe *job_list;
746 # define G_saved_tty_pgrp (G.saved_tty_pgrp)
748 # define G_saved_tty_pgrp 0
750 char o_opt[NUM_OPT_O];
751 #if ENABLE_HUSH_MODE_X
752 # define G_x_mode (G.o_opt[OPT_O_XTRACE])
756 smallint flag_SIGINT;
757 #if ENABLE_HUSH_LOOPS
758 smallint flag_break_continue;
760 #if ENABLE_HUSH_FUNCTIONS
761 /* 0: outside of a function (or sourced file)
762 * -1: inside of a function, ok to use return builtin
763 * 1: return is invoked, skip all till end of func
765 smallint flag_return_in_progress;
766 # define G_flag_return_in_progress (G.flag_return_in_progress)
768 # define G_flag_return_in_progress 0
770 smallint exiting; /* used to prevent EXIT trap recursion */
771 /* These four support $?, $#, and $1 */
772 smalluint last_exitcode;
773 /* are global_argv and global_argv[1..n] malloced? (note: not [0]) */
774 smalluint global_args_malloced;
775 /* how many non-NULL argv's we have. NB: $# + 1 */
779 char *argv0_for_re_execing;
781 #if ENABLE_HUSH_LOOPS
782 unsigned depth_break_continue;
783 unsigned depth_of_loop;
787 struct variable *top_var;
788 char **expanded_assignments;
789 #if ENABLE_HUSH_FUNCTIONS
790 struct function *top_func;
791 # if ENABLE_HUSH_LOCAL
792 struct variable **shadowed_vars_pp;
793 unsigned func_nest_level;
796 /* Signal and trap handling */
798 unsigned count_SIGCHLD;
799 unsigned handled_SIGCHLD;
800 smallint we_have_children;
802 struct FILE_list *FILE_list;
803 /* Which signals have non-DFL handler (even with no traps set)?
804 * Set at the start to:
805 * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS)
806 * SPECIAL_INTERACTIVE_SIGS are cleared after fork.
807 * The rest is cleared right before execv syscalls.
808 * Other than these two times, never modified.
810 unsigned special_sig_mask;
812 unsigned fatal_sig_mask;
813 # define G_fatal_sig_mask G.fatal_sig_mask
815 # define G_fatal_sig_mask 0
817 char **traps; /* char *traps[NSIG] */
818 sigset_t pending_set;
820 unsigned long memleak_value;
824 #if ENABLE_FEATURE_EDITING
825 char user_input_buf[CONFIG_FEATURE_EDITING_MAX_LEN];
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 static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC)
1257 /* We avoid taking stdio fds. Mimicking ash: use fds above 9 */
1258 int newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, 10);
1260 /* fd was not open? */
1270 /* Manipulating the list of open FILEs */
1271 static FILE *remember_FILE(FILE *fp)
1274 struct FILE_list *n = xmalloc(sizeof(*n));
1275 n->next = G.FILE_list;
1279 close_on_exec_on(n->fd);
1283 static void fclose_and_forget(FILE *fp)
1285 struct FILE_list **pp = &G.FILE_list;
1287 struct FILE_list *cur = *pp;
1288 if (cur->fp == fp) {
1297 static int save_FILEs_on_redirect(int fd)
1299 struct FILE_list *fl = G.FILE_list;
1302 /* We use it only on script files, they are all CLOEXEC */
1303 fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC);
1310 static void restore_redirected_FILEs(void)
1312 struct FILE_list *fl = G.FILE_list;
1314 int should_be = fileno(fl->fp);
1315 if (fl->fd != should_be) {
1316 xmove_fd(fl->fd, should_be);
1322 #if ENABLE_FEATURE_SH_STANDALONE
1323 static void close_all_FILE_list(void)
1325 struct FILE_list *fl = G.FILE_list;
1327 /* fclose would also free FILE object.
1328 * It is disastrous if we share memory with a vforked parent.
1329 * I'm not sure we never come here after vfork.
1330 * Therefore just close fd, nothing more.
1332 /*fclose(fl->fp); - unsafe */
1340 /* Helpers for setting new $n and restoring them back
1342 typedef struct save_arg_t {
1346 smallint sv_g_malloced;
1349 static void save_and_replace_G_args(save_arg_t *sv, char **argv)
1353 sv->sv_argv0 = argv[0];
1354 sv->sv_g_argv = G.global_argv;
1355 sv->sv_g_argc = G.global_argc;
1356 sv->sv_g_malloced = G.global_args_malloced;
1358 argv[0] = G.global_argv[0]; /* retain $0 */
1359 G.global_argv = argv;
1360 G.global_args_malloced = 0;
1368 static void restore_G_args(save_arg_t *sv, char **argv)
1372 if (G.global_args_malloced) {
1373 /* someone ran "set -- arg1 arg2 ...", undo */
1375 while (*++pp) /* note: does not free $0 */
1377 free(G.global_argv);
1379 argv[0] = sv->sv_argv0;
1380 G.global_argv = sv->sv_g_argv;
1381 G.global_argc = sv->sv_g_argc;
1382 G.global_args_malloced = sv->sv_g_malloced;
1386 /* Basic theory of signal handling in shell
1387 * ========================================
1388 * This does not describe what hush does, rather, it is current understanding
1389 * what it _should_ do. If it doesn't, it's a bug.
1390 * http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
1392 * Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
1393 * is finished or backgrounded. It is the same in interactive and
1394 * non-interactive shells, and is the same regardless of whether
1395 * a user trap handler is installed or a shell special one is in effect.
1396 * ^C or ^Z from keyboard seems to execute "at once" because it usually
1397 * backgrounds (i.e. stops) or kills all members of currently running
1400 * Wait builtin is interruptible by signals for which user trap is set
1401 * or by SIGINT in interactive shell.
1403 * Trap handlers will execute even within trap handlers. (right?)
1405 * User trap handlers are forgotten when subshell ("(cmd)") is entered,
1406 * except for handlers set to '' (empty string).
1408 * If job control is off, backgrounded commands ("cmd &")
1409 * have SIGINT, SIGQUIT set to SIG_IGN.
1411 * Commands which are run in command substitution ("`cmd`")
1412 * have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
1414 * Ordinary commands have signals set to SIG_IGN/DFL as inherited
1415 * by the shell from its parent.
1417 * Signals which differ from SIG_DFL action
1418 * (note: child (i.e., [v]forked) shell is not an interactive shell):
1421 * SIGTERM (interactive): ignore
1422 * SIGHUP (interactive):
1423 * send SIGCONT to stopped jobs, send SIGHUP to all jobs and exit
1424 * SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
1425 * Note that ^Z is handled not by trapping SIGTSTP, but by seeing
1426 * that all pipe members are stopped. Try this in bash:
1427 * while :; do :; done - ^Z does not background it
1428 * (while :; do :; done) - ^Z backgrounds it
1429 * SIGINT (interactive): wait for last pipe, ignore the rest
1430 * of the command line, show prompt. NB: ^C does not send SIGINT
1431 * to interactive shell while shell is waiting for a pipe,
1432 * since shell is bg'ed (is not in foreground process group).
1433 * Example 1: this waits 5 sec, but does not execute ls:
1434 * "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
1435 * Example 2: this does not wait and does not execute ls:
1436 * "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
1437 * Example 3: this does not wait 5 sec, but executes ls:
1438 * "sleep 5; ls -l" + press ^C
1439 * Example 4: this does not wait and does not execute ls:
1440 * "sleep 5 & wait; ls -l" + press ^C
1442 * (What happens to signals which are IGN on shell start?)
1443 * (What happens with signal mask on shell start?)
1445 * Old implementation
1446 * ==================
1447 * We use in-kernel pending signal mask to determine which signals were sent.
1448 * We block all signals which we don't want to take action immediately,
1449 * i.e. we block all signals which need to have special handling as described
1450 * above, and all signals which have traps set.
1451 * After each pipe execution, we extract any pending signals via sigtimedwait()
1454 * unsigned special_sig_mask: a mask of such "special" signals
1455 * sigset_t blocked_set: current blocked signal set
1458 * clear bit in blocked_set unless it is also in special_sig_mask
1459 * "trap 'cmd' SIGxxx":
1460 * set bit in blocked_set (even if 'cmd' is '')
1461 * after [v]fork, if we plan to be a shell:
1462 * unblock signals with special interactive handling
1463 * (child shell is not interactive),
1464 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1465 * after [v]fork, if we plan to exec:
1466 * POSIX says fork clears pending signal mask in child - no need to clear it.
1467 * Restore blocked signal set to one inherited by shell just prior to exec.
1469 * Note: as a result, we do not use signal handlers much. The only uses
1470 * are to count SIGCHLDs
1471 * and to restore tty pgrp on signal-induced exit.
1474 * Standard says "When a subshell is entered, traps that are not being ignored
1475 * are set to the default actions". bash interprets it so that traps which
1476 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1478 * Problem: the above approach makes it unwieldy to catch signals while
1479 * we are in read builtin, or while we read commands from stdin:
1480 * masked signals are not visible!
1482 * New implementation
1483 * ==================
1484 * We record each signal we are interested in by installing signal handler
1485 * for them - a bit like emulating kernel pending signal mask in userspace.
1486 * We are interested in: signals which need to have special handling
1487 * as described above, and all signals which have traps set.
1488 * Signals are recorded in pending_set.
1489 * After each pipe execution, we extract any pending signals
1492 * unsigned special_sig_mask: a mask of shell-special signals.
1493 * unsigned fatal_sig_mask: a mask of signals on which we restore tty pgrp.
1494 * char *traps[sig] if trap for sig is set (even if it's '').
1495 * sigset_t pending_set: set of sigs we received.
1498 * if sig is in special_sig_mask, set handler back to:
1499 * record_pending_signo, or to IGN if it's a tty stop signal
1500 * if sig is in fatal_sig_mask, set handler back to sigexit.
1501 * else: set handler back to SIG_DFL
1502 * "trap 'cmd' SIGxxx":
1503 * set handler to record_pending_signo.
1505 * set handler to SIG_IGN.
1506 * after [v]fork, if we plan to be a shell:
1507 * set signals with special interactive handling to SIG_DFL
1508 * (because child shell is not interactive),
1509 * unset all traps except '' (note: regardless of child shell's type - {}, (), etc)
1510 * after [v]fork, if we plan to exec:
1511 * POSIX says fork clears pending signal mask in child - no need to clear it.
1513 * To make wait builtin interruptible, we handle SIGCHLD as special signal,
1514 * otherwise (if we leave it SIG_DFL) sigsuspend in wait builtin will not wake up on it.
1517 * Standard says "When a subshell is entered, traps that are not being ignored
1518 * are set to the default actions". bash interprets it so that traps which
1519 * are set to '' (ignore) are NOT reset to defaults. We do the same.
1522 SPECIAL_INTERACTIVE_SIGS = 0
1527 SPECIAL_JOBSTOP_SIGS = 0
1536 static void record_pending_signo(int sig)
1538 sigaddset(&G.pending_set, sig);
1539 #if ENABLE_HUSH_FAST
1540 if (sig == SIGCHLD) {
1542 //bb_error_msg("[%d] SIGCHLD_handler: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1547 static sighandler_t install_sighandler(int sig, sighandler_t handler)
1549 struct sigaction old_sa;
1551 /* We could use signal() to install handlers... almost:
1552 * except that we need to mask ALL signals while handlers run.
1553 * I saw signal nesting in strace, race window isn't small.
1554 * SA_RESTART is also needed, but in Linux, signal()
1555 * sets SA_RESTART too.
1557 /* memset(&G.sa, 0, sizeof(G.sa)); - already done */
1558 /* sigfillset(&G.sa.sa_mask); - already done */
1559 /* G.sa.sa_flags = SA_RESTART; - already done */
1560 G.sa.sa_handler = handler;
1561 sigaction(sig, &G.sa, &old_sa);
1562 return old_sa.sa_handler;
1565 static void hush_exit(int exitcode) NORETURN;
1567 static void restore_ttypgrp_and__exit(void) NORETURN;
1568 static void restore_ttypgrp_and__exit(void)
1570 /* xfunc has failed! die die die */
1571 /* no EXIT traps, this is an escape hatch! */
1573 hush_exit(xfunc_error_retval);
1578 /* Needed only on some libc:
1579 * It was observed that on exit(), fgetc'ed buffered data
1580 * gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
1581 * With the net effect that even after fork(), not vfork(),
1582 * exit() in NOEXECed applet in "sh SCRIPT":
1583 * noexec_applet_here
1584 * echo END_OF_SCRIPT
1585 * lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
1586 * This makes "echo END_OF_SCRIPT" executed twice.
1587 * Similar problems can be seen with die_if_script() -> xfunc_die()
1588 * and in `cmd` handling.
1589 * If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
1591 static void fflush_and__exit(void) NORETURN;
1592 static void fflush_and__exit(void)
1595 _exit(xfunc_error_retval);
1598 /* After [v]fork, in child: do not restore tty pgrp on xfunc death */
1599 # define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
1600 /* After [v]fork, in parent: restore tty pgrp on xfunc death */
1601 # define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
1603 /* Restores tty foreground process group, and exits.
1604 * May be called as signal handler for fatal signal
1605 * (will resend signal to itself, producing correct exit state)
1606 * or called directly with -EXITCODE.
1607 * We also call it if xfunc is exiting.
1609 static void sigexit(int sig) NORETURN;
1610 static void sigexit(int sig)
1612 /* Careful: we can end up here after [v]fork. Do not restore
1613 * tty pgrp then, only top-level shell process does that */
1614 if (G_saved_tty_pgrp && getpid() == G.root_pid) {
1615 /* Disable all signals: job control, SIGPIPE, etc.
1616 * Mostly paranoid measure, to prevent infinite SIGTTOU.
1618 sigprocmask_allsigs(SIG_BLOCK);
1619 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
1622 /* Not a signal, just exit */
1626 kill_myself_with_sig(sig); /* does not return */
1630 # define disable_restore_tty_pgrp_on_exit() ((void)0)
1631 # define enable_restore_tty_pgrp_on_exit() ((void)0)
1635 static sighandler_t pick_sighandler(unsigned sig)
1637 sighandler_t handler = SIG_DFL;
1638 if (sig < sizeof(unsigned)*8) {
1639 unsigned sigmask = (1 << sig);
1643 if (G_fatal_sig_mask & sigmask)
1647 /* sig has special handling? */
1648 if (G.special_sig_mask & sigmask) {
1649 handler = record_pending_signo;
1650 /* TTIN/TTOU/TSTP can't be set to record_pending_signo
1651 * in order to ignore them: they will be raised
1652 * in an endless loop when we try to do some
1653 * terminal ioctls! We do have to _ignore_ these.
1655 if (SPECIAL_JOBSTOP_SIGS & sigmask)
1662 /* Restores tty foreground process group, and exits. */
1663 static void hush_exit(int exitcode)
1665 #if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
1666 save_history(G.line_input_state);
1670 if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
1672 /* argv[0] is unused */
1673 argv[1] = G.traps[0];
1675 G.exiting = 1; /* prevent EXIT trap recursion */
1676 /* Note: G.traps[0] is not cleared!
1677 * "trap" will still show it, if executed
1682 #if ENABLE_FEATURE_CLEAN_UP
1684 struct variable *cur_var;
1685 if (G.cwd != bb_msg_unknown)
1687 cur_var = G.top_var;
1689 struct variable *tmp = cur_var;
1690 if (!cur_var->max_len)
1691 free(cur_var->varstr);
1692 cur_var = cur_var->next;
1700 sigexit(- (exitcode & 0xff));
1707 //TODO: return a mask of ALL handled sigs?
1708 static int check_and_run_traps(void)
1715 if (sigisemptyset(&G.pending_set))
1720 if (sigismember(&G.pending_set, sig)) {
1721 sigdelset(&G.pending_set, sig);
1724 } while (sig < NSIG);
1727 if (G.traps && G.traps[sig]) {
1728 debug_printf_exec("%s: sig:%d handler:'%s'\n", __func__, sig, G.traps[sig]);
1729 if (G.traps[sig][0]) {
1730 /* We have user-defined handler */
1731 smalluint save_rcode;
1733 /* argv[0] is unused */
1734 argv[1] = G.traps[sig];
1736 save_rcode = G.last_exitcode;
1738 //FIXME: shouldn't it be set to 128 + sig instead?
1739 G.last_exitcode = save_rcode;
1741 } /* else: "" trap, ignoring signal */
1744 /* not a trap: special action */
1747 debug_printf_exec("%s: sig:%d default SIGINT handler\n", __func__, sig);
1754 debug_printf_exec("%s: sig:%d default SIGHUP handler\n", __func__, sig);
1755 /* bash is observed to signal whole process groups,
1756 * not individual processes */
1757 for (job = G.job_list; job; job = job->next) {
1760 debug_printf_exec("HUPing pgrp %d\n", job->pgrp);
1761 if (kill(- job->pgrp, SIGHUP) == 0)
1762 kill(- job->pgrp, SIGCONT);
1767 #if ENABLE_HUSH_FAST
1769 debug_printf_exec("%s: sig:%d default SIGCHLD handler\n", __func__, sig);
1771 //bb_error_msg("[%d] check_and_run_traps: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
1773 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1774 * This simplifies wait builtin a bit.
1778 default: /* ignored: */
1779 debug_printf_exec("%s: sig:%d default handling is to ignore\n", __func__, sig);
1780 /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
1782 * We dont do 'last_sig = sig' here -> NOT returning this sig.
1783 * Example: wait is not interrupted by TERM
1784 * in interactive shell, because TERM is ignored.
1793 static const char *get_cwd(int force)
1795 if (force || G.cwd == NULL) {
1796 /* xrealloc_getcwd_or_warn(arg) calls free(arg),
1797 * we must not try to free(bb_msg_unknown) */
1798 if (G.cwd == bb_msg_unknown)
1800 G.cwd = xrealloc_getcwd_or_warn((char *)G.cwd);
1802 G.cwd = bb_msg_unknown;
1809 * Shell and environment variable support
1811 static struct variable **get_ptr_to_local_var(const char *name, unsigned len)
1813 struct variable **pp;
1814 struct variable *cur;
1817 while ((cur = *pp) != NULL) {
1818 if (strncmp(cur->varstr, name, len) == 0 && cur->varstr[len] == '=')
1825 static const char* FAST_FUNC get_local_var_value(const char *name)
1827 struct variable **vpp;
1828 unsigned len = strlen(name);
1830 if (G.expanded_assignments) {
1831 char **cpp = G.expanded_assignments;
1834 if (strncmp(cp, name, len) == 0 && cp[len] == '=')
1835 return cp + len + 1;
1840 vpp = get_ptr_to_local_var(name, len);
1842 return (*vpp)->varstr + len + 1;
1844 if (strcmp(name, "PPID") == 0)
1845 return utoa(G.root_ppid);
1846 // bash compat: UID? EUID?
1847 #if ENABLE_HUSH_RANDOM_SUPPORT
1848 if (strcmp(name, "RANDOM") == 0)
1849 return utoa(next_random(&G.random_gen));
1854 /* str holds "NAME=VAL" and is expected to be malloced.
1855 * We take ownership of it.
1857 * 0: do not change export flag
1858 * (if creating new variable, flag will be 0)
1859 * 1: set export flag and putenv the variable
1860 * -1: clear export flag and unsetenv the variable
1861 * flg_read_only is set only when we handle -R var=val
1863 #if !BB_MMU && ENABLE_HUSH_LOCAL
1864 /* all params are used */
1865 #elif BB_MMU && ENABLE_HUSH_LOCAL
1866 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1867 set_local_var(str, flg_export, local_lvl)
1868 #elif BB_MMU && !ENABLE_HUSH_LOCAL
1869 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1870 set_local_var(str, flg_export)
1871 #elif !BB_MMU && !ENABLE_HUSH_LOCAL
1872 #define set_local_var(str, flg_export, local_lvl, flg_read_only) \
1873 set_local_var(str, flg_export, flg_read_only)
1875 static int set_local_var(char *str, int flg_export, int local_lvl, int flg_read_only)
1877 struct variable **var_pp;
1878 struct variable *cur;
1879 char *free_me = NULL;
1883 eq_sign = strchr(str, '=');
1884 if (!eq_sign) { /* not expected to ever happen? */
1889 name_len = eq_sign - str + 1; /* including '=' */
1890 var_pp = &G.top_var;
1891 while ((cur = *var_pp) != NULL) {
1892 if (strncmp(cur->varstr, str, name_len) != 0) {
1893 var_pp = &cur->next;
1897 /* We found an existing var with this name */
1898 if (cur->flg_read_only) {
1902 bb_error_msg("%s: readonly variable", str);
1906 if (flg_export == -1) { // "&& cur->flg_export" ?
1907 debug_printf_env("%s: unsetenv '%s'\n", __func__, str);
1912 #if ENABLE_HUSH_LOCAL
1913 if (cur->func_nest_level < local_lvl) {
1914 /* New variable is declared as local,
1915 * and existing one is global, or local
1916 * from enclosing function.
1917 * Remove and save old one: */
1918 *var_pp = cur->next;
1919 cur->next = *G.shadowed_vars_pp;
1920 *G.shadowed_vars_pp = cur;
1921 /* bash 3.2.33(1) and exported vars:
1923 * # f() { local z=a; env | grep ^z; }
1929 if (cur->flg_export)
1934 if (strcmp(cur->varstr + name_len, eq_sign + 1) == 0) {
1939 if (cur->max_len != 0) {
1940 if (cur->max_len >= strlen(str)) {
1941 /* This one is from startup env, reuse space */
1942 strcpy(cur->varstr, str);
1947 goto set_str_and_exp;
1949 /* max_len == 0 signifies "malloced" var, which we can
1950 * (and have to) free. But we can't free(cur->varstr) here:
1951 * if cur->flg_export is 1, it is in the environment.
1952 * We should either unsetenv+free, or wait until putenv,
1953 * then putenv(new)+free(old).
1955 free_me = cur->varstr;
1956 goto set_str_and_exp;
1959 /* Not found - create new variable struct */
1960 cur = xzalloc(sizeof(*cur));
1961 #if ENABLE_HUSH_LOCAL
1962 cur->func_nest_level = local_lvl;
1964 cur->next = *var_pp;
1970 cur->flg_read_only = flg_read_only;
1973 if (flg_export == 1)
1974 cur->flg_export = 1;
1975 if (name_len == 4 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
1976 cmdedit_update_prompt();
1977 if (cur->flg_export) {
1978 if (flg_export == -1) {
1979 cur->flg_export = 0;
1980 /* unsetenv was already done */
1983 debug_printf_env("%s: putenv '%s'\n", __func__, cur->varstr);
1984 i = putenv(cur->varstr);
1985 /* only now we can free old exported malloced string */
1994 /* Used at startup and after each cd */
1995 static void set_pwd_var(int exp)
1997 set_local_var(xasprintf("PWD=%s", get_cwd(/*force:*/ 1)),
1998 /*exp:*/ exp, /*lvl:*/ 0, /*ro:*/ 0);
2001 static int unset_local_var_len(const char *name, int name_len)
2003 struct variable *cur;
2004 struct variable **var_pp;
2007 return EXIT_SUCCESS;
2008 var_pp = &G.top_var;
2009 while ((cur = *var_pp) != NULL) {
2010 if (strncmp(cur->varstr, name, name_len) == 0 && cur->varstr[name_len] == '=') {
2011 if (cur->flg_read_only) {
2012 bb_error_msg("%s: readonly variable", name);
2013 return EXIT_FAILURE;
2015 *var_pp = cur->next;
2016 debug_printf_env("%s: unsetenv '%s'\n", __func__, cur->varstr);
2017 bb_unsetenv(cur->varstr);
2018 if (name_len == 3 && cur->varstr[0] == 'P' && cur->varstr[1] == 'S')
2019 cmdedit_update_prompt();
2023 return EXIT_SUCCESS;
2025 var_pp = &cur->next;
2027 return EXIT_SUCCESS;
2030 static int unset_local_var(const char *name)
2032 return unset_local_var_len(name, strlen(name));
2035 static void unset_vars(char **strings)
2043 const char *eq = strchrnul(*v, '=');
2044 unset_local_var_len(*v, (int)(eq - *v));
2050 static void FAST_FUNC set_local_var_from_halves(const char *name, const char *val)
2052 char *var = xasprintf("%s=%s", name, val);
2053 set_local_var(var, /*flags:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
2058 * Helpers for "var1=val1 var2=val2 cmd" feature
2060 static void add_vars(struct variable *var)
2062 struct variable *next;
2066 var->next = G.top_var;
2068 if (var->flg_export) {
2069 debug_printf_env("%s: restoring exported '%s'\n", __func__, var->varstr);
2070 putenv(var->varstr);
2072 debug_printf_env("%s: restoring variable '%s'\n", __func__, var->varstr);
2078 static struct variable *set_vars_and_save_old(char **strings)
2081 struct variable *old = NULL;
2087 struct variable *var_p;
2088 struct variable **var_pp;
2091 eq = strchr(*s, '=');
2093 var_pp = get_ptr_to_local_var(*s, eq - *s);
2095 /* Remove variable from global linked list */
2097 debug_printf_env("%s: removing '%s'\n", __func__, var_p->varstr);
2098 *var_pp = var_p->next;
2099 /* Add it to returned list */
2103 set_local_var(*s, /*exp:*/ 1, /*lvl:*/ 0, /*ro:*/ 0);
2114 static void reinit_unicode_for_hush(void)
2116 /* Unicode support should be activated even if LANG is set
2117 * _during_ shell execution, not only if it was set when
2118 * shell was started. Therefore, re-check LANG every time:
2120 if (ENABLE_FEATURE_CHECK_UNICODE_IN_ENV
2121 || ENABLE_UNICODE_USING_LOCALE
2123 const char *s = get_local_var_value("LC_ALL");
2124 if (!s) s = get_local_var_value("LC_CTYPE");
2125 if (!s) s = get_local_var_value("LANG");
2131 * in_str support (strings, and "strings" read from files).
2134 #if ENABLE_HUSH_INTERACTIVE
2135 /* To test correct lineedit/interactive behavior, type from command line:
2141 * It excercises a lot of corner cases.
2143 static void cmdedit_update_prompt(void)
2145 if (ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2146 G.PS1 = get_local_var_value("PS1");
2149 G.PS2 = get_local_var_value("PS2");
2156 static const char *setup_prompt_string(int promptmode)
2158 const char *prompt_str;
2159 debug_printf("setup_prompt_string %d ", promptmode);
2160 if (!ENABLE_FEATURE_EDITING_FANCY_PROMPT) {
2161 /* Set up the prompt */
2162 if (promptmode == 0) { /* PS1 */
2164 /* bash uses $PWD value, even if it is set by user.
2165 * It uses current dir only if PWD is unset.
2166 * We always use current dir. */
2167 G.PS1 = xasprintf("%s %c ", get_cwd(0), (geteuid() != 0) ? '$' : '#');
2172 prompt_str = (promptmode == 0) ? G.PS1 : G.PS2;
2173 debug_printf("prompt_str '%s'\n", prompt_str);
2176 static int get_user_input(struct in_str *i)
2179 const char *prompt_str;
2181 prompt_str = setup_prompt_string(i->promptmode);
2182 # if ENABLE_FEATURE_EDITING
2184 reinit_unicode_for_hush();
2185 if (G.flag_SIGINT) {
2186 /* There was ^C'ed, make it look prettier: */
2190 /* buglet: SIGINT will not make new prompt to appear _at once_,
2191 * only after <Enter>. (^C works immediately) */
2192 r = read_line_input(G.line_input_state, prompt_str,
2193 G.user_input_buf, CONFIG_FEATURE_EDITING_MAX_LEN-1,
2196 /* read_line_input intercepts ^C, "convert" it to SIGINT */
2198 write(STDOUT_FILENO, "^C", 2);
2201 check_and_run_traps();
2202 if (r != 0 && !G.flag_SIGINT)
2204 /* ^C or SIGINT: repeat */
2205 G.last_exitcode = 128 + SIGINT;
2208 /* EOF/error detected */
2210 i->peek_buf[0] = r = EOF;
2213 i->p = G.user_input_buf;
2214 return (unsigned char)*i->p++;
2218 if (i->last_char == '\0' || i->last_char == '\n') {
2219 /* Why check_and_run_traps here? Try this interactively:
2220 * $ trap 'echo INT' INT; (sleep 2; kill -INT $$) &
2221 * $ <[enter], repeatedly...>
2222 * Without check_and_run_traps, handler never runs.
2224 check_and_run_traps();
2225 fputs(prompt_str, stdout);
2228 //FIXME: here ^C or SIGINT will have effect only after <Enter>
2230 /* In !ENABLE_FEATURE_EDITING we don't use read_line_input,
2231 * no ^C masking happens during fgetc, no special code for ^C:
2232 * it generates SIGINT as usual.
2234 check_and_run_traps();
2236 G.last_exitcode = 128 + SIGINT;
2243 /* This is the magic location that prints prompts
2244 * and gets data back from the user */
2245 static int fgetc_interactive(struct in_str *i)
2248 /* If it's interactive stdin, get new line. */
2249 if (G_interactive_fd && i->file == stdin) {
2250 /* Returns first char (or EOF), the rest is in i->p[] */
2251 ch = get_user_input(i);
2252 i->promptmode = 1; /* PS2 */
2254 /* Not stdin: script file, sourced file, etc */
2255 do ch = fgetc(i->file); while (ch == '\0');
2260 static inline int fgetc_interactive(struct in_str *i)
2263 do ch = fgetc(i->file); while (ch == '\0');
2266 #endif /* INTERACTIVE */
2268 static int i_getch(struct in_str *i)
2273 /* string-based in_str */
2274 ch = (unsigned char)*i->p;
2283 /* FILE-based in_str */
2285 #if ENABLE_FEATURE_EDITING
2286 /* This can be stdin, check line editing char[] buffer */
2287 if (i->p && *i->p != '\0') {
2288 ch = (unsigned char)*i->p++;
2292 /* peek_buf[] is an int array, not char. Can contain EOF. */
2293 ch = i->peek_buf[0];
2295 int ch2 = i->peek_buf[1];
2296 i->peek_buf[0] = ch2;
2297 if (ch2 == 0) /* very likely, avoid redundant write */
2303 ch = fgetc_interactive(i);
2305 debug_printf("file_get: got '%c' %d\n", ch, ch);
2310 static int i_peek(struct in_str *i)
2315 /* string-based in_str */
2316 /* Doesn't report EOF on NUL. None of the callers care. */
2317 return (unsigned char)*i->p;
2320 /* FILE-based in_str */
2322 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2323 /* This can be stdin, check line editing char[] buffer */
2324 if (i->p && *i->p != '\0')
2325 return (unsigned char)*i->p;
2327 /* peek_buf[] is an int array, not char. Can contain EOF. */
2328 ch = i->peek_buf[0];
2332 /* Need to get a new char */
2333 ch = fgetc_interactive(i);
2334 debug_printf("file_peek: got '%c' %d\n", ch, ch);
2336 /* Save it by either rolling back line editing buffer, or in i->peek_buf[0] */
2337 #if ENABLE_FEATURE_EDITING && ENABLE_HUSH_INTERACTIVE
2343 i->peek_buf[0] = ch;
2344 /*i->peek_buf[1] = 0; - already is */
2348 /* Only ever called if i_peek() was called, and did not return EOF.
2349 * IOW: we know the previous peek saw an ordinary char, not EOF, not NUL,
2350 * not end-of-line. Therefore we never need to read a new editing line here.
2352 static int i_peek2(struct in_str *i)
2356 /* There are two cases when i->p[] buffer exists.
2357 * (1) it's a string in_str.
2358 * (2) It's a file, and we have a saved line editing buffer.
2359 * In both cases, we know that i->p[0] exists and not NUL, and
2360 * the peek2 result is in i->p[1].
2363 return (unsigned char)i->p[1];
2365 /* Now we know it is a file-based in_str. */
2367 /* peek_buf[] is an int array, not char. Can contain EOF. */
2368 /* Is there 2nd char? */
2369 ch = i->peek_buf[1];
2371 /* We did not read it yet, get it now */
2372 do ch = fgetc(i->file); while (ch == '\0');
2373 i->peek_buf[1] = ch;
2376 debug_printf("file_peek2: got '%c' %d\n", ch, ch);
2380 static void setup_file_in_str(struct in_str *i, FILE *f)
2382 memset(i, 0, sizeof(*i));
2383 /* i->promptmode = 0; - PS1 (memset did it) */
2388 static void setup_string_in_str(struct in_str *i, const char *s)
2390 memset(i, 0, sizeof(*i));
2391 /* i->promptmode = 0; - PS1 (memset did it) */
2392 /*i->file = NULL */;
2400 #define B_CHUNK (32 * sizeof(char*))
2402 static void o_reset_to_empty_unquoted(o_string *o)
2405 o->has_quoted_part = 0;
2410 static void o_free(o_string *o)
2413 memset(o, 0, sizeof(*o));
2416 static ALWAYS_INLINE void o_free_unsafe(o_string *o)
2421 static void o_grow_by(o_string *o, int len)
2423 if (o->length + len > o->maxlen) {
2424 o->maxlen += (2 * len) | (B_CHUNK-1);
2425 o->data = xrealloc(o->data, 1 + o->maxlen);
2429 static void o_addchr(o_string *o, int ch)
2431 debug_printf("o_addchr: '%c' o->length=%d o=%p\n", ch, o->length, o);
2432 if (o->length < o->maxlen) {
2433 /* likely. avoid o_grow_by() call */
2435 o->data[o->length] = ch;
2437 o->data[o->length] = '\0';
2445 /* Valid only if we know o_string is not empty */
2446 static void o_delchr(o_string *o)
2449 o->data[o->length] = '\0';
2453 static void o_addblock(o_string *o, const char *str, int len)
2456 memcpy(&o->data[o->length], str, len);
2458 o->data[o->length] = '\0';
2461 static void o_addstr(o_string *o, const char *str)
2463 o_addblock(o, str, strlen(str));
2467 static void nommu_addchr(o_string *o, int ch)
2473 # define nommu_addchr(o, str) ((void)0)
2476 static void o_addstr_with_NUL(o_string *o, const char *str)
2478 o_addblock(o, str, strlen(str) + 1);
2482 * HUSH_BRACE_EXPANSION code needs corresponding quoting on variable expansion side.
2483 * Currently, "v='{q,w}'; echo $v" erroneously expands braces in $v.
2484 * Apparently, on unquoted $v bash still does globbing
2485 * ("v='*.txt'; echo $v" prints all .txt files),
2486 * but NOT brace expansion! Thus, there should be TWO independent
2487 * quoting mechanisms on $v expansion side: one protects
2488 * $v from brace expansion, and other additionally protects "$v" against globbing.
2489 * We have only second one.
2492 #if ENABLE_HUSH_BRACE_EXPANSION
2493 # define MAYBE_BRACES "{}"
2495 # define MAYBE_BRACES ""
2498 /* My analysis of quoting semantics tells me that state information
2499 * is associated with a destination, not a source.
2501 static void o_addqchr(o_string *o, int ch)
2504 char *found = strchr("*?[\\" MAYBE_BRACES, ch);
2509 o->data[o->length] = '\\';
2512 o->data[o->length] = ch;
2514 o->data[o->length] = '\0';
2517 static void o_addQchr(o_string *o, int ch)
2520 if ((o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)
2521 && strchr("*?[\\" MAYBE_BRACES, ch)
2524 o->data[o->length] = '\\';
2528 o->data[o->length] = ch;
2530 o->data[o->length] = '\0';
2533 static void o_addqblock(o_string *o, const char *str, int len)
2538 int ordinary_cnt = strcspn(str, "*?[\\" MAYBE_BRACES);
2539 if (ordinary_cnt > len) /* paranoia */
2541 o_addblock(o, str, ordinary_cnt);
2542 if (ordinary_cnt == len)
2543 return; /* NUL is already added by o_addblock */
2544 str += ordinary_cnt;
2545 len -= ordinary_cnt + 1; /* we are processing + 1 char below */
2549 if (ch) { /* it is necessarily one of "*?[\\" MAYBE_BRACES */
2551 o->data[o->length] = '\\';
2555 o->data[o->length] = ch;
2558 o->data[o->length] = '\0';
2561 static void o_addQblock(o_string *o, const char *str, int len)
2563 if (!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS)) {
2564 o_addblock(o, str, len);
2567 o_addqblock(o, str, len);
2570 static void o_addQstr(o_string *o, const char *str)
2572 o_addQblock(o, str, strlen(str));
2575 /* A special kind of o_string for $VAR and `cmd` expansion.
2576 * It contains char* list[] at the beginning, which is grown in 16 element
2577 * increments. Actual string data starts at the next multiple of 16 * (char*).
2578 * list[i] contains an INDEX (int!) into this string data.
2579 * It means that if list[] needs to grow, data needs to be moved higher up
2580 * but list[i]'s need not be modified.
2581 * NB: remembering how many list[i]'s you have there is crucial.
2582 * o_finalize_list() operation post-processes this structure - calculates
2583 * and stores actual char* ptrs in list[]. Oh, it NULL terminates it as well.
2585 #if DEBUG_EXPAND || DEBUG_GLOB
2586 static void debug_print_list(const char *prefix, o_string *o, int n)
2588 char **list = (char**)o->data;
2589 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2593 fdprintf(2, "%s: list:%p n:%d string_start:%d length:%d maxlen:%d glob:%d quoted:%d escape:%d\n",
2594 prefix, list, n, string_start, o->length, o->maxlen,
2595 !!(o->o_expflags & EXP_FLAG_GLOB),
2597 !!(o->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
2600 fdprintf(2, " list[%d]=%d '%s' %p\n", i, (int)(uintptr_t)list[i],
2601 o->data + (int)(uintptr_t)list[i] + string_start,
2602 o->data + (int)(uintptr_t)list[i] + string_start);
2606 const char *p = o->data + (int)(uintptr_t)list[n - 1] + string_start;
2608 fdprintf(2, " total_sz:%ld\n", (long)((p + strlen(p) + 1) - o->data));
2612 # define debug_print_list(prefix, o, n) ((void)0)
2615 /* n = o_save_ptr_helper(str, n) "starts new string" by storing an index value
2616 * in list[n] so that it points past last stored byte so far.
2617 * It returns n+1. */
2618 static int o_save_ptr_helper(o_string *o, int n)
2620 char **list = (char**)o->data;
2624 if (!o->has_empty_slot) {
2625 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2626 string_len = o->length - string_start;
2627 if (!(n & 0xf)) { /* 0, 0x10, 0x20...? */
2628 debug_printf_list("list[%d]=%d string_start=%d (growing)\n", n, string_len, string_start);
2629 /* list[n] points to string_start, make space for 16 more pointers */
2630 o->maxlen += 0x10 * sizeof(list[0]);
2631 o->data = xrealloc(o->data, o->maxlen + 1);
2632 list = (char**)o->data;
2633 memmove(list + n + 0x10, list + n, string_len);
2634 o->length += 0x10 * sizeof(list[0]);
2636 debug_printf_list("list[%d]=%d string_start=%d\n",
2637 n, string_len, string_start);
2640 /* We have empty slot at list[n], reuse without growth */
2641 string_start = ((n+1 + 0xf) & ~0xf) * sizeof(list[0]); /* NB: n+1! */
2642 string_len = o->length - string_start;
2643 debug_printf_list("list[%d]=%d string_start=%d (empty slot)\n",
2644 n, string_len, string_start);
2645 o->has_empty_slot = 0;
2647 o->has_quoted_part = 0;
2648 list[n] = (char*)(uintptr_t)string_len;
2652 /* "What was our last o_save_ptr'ed position (byte offset relative o->data)?" */
2653 static int o_get_last_ptr(o_string *o, int n)
2655 char **list = (char**)o->data;
2656 int string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2658 return ((int)(uintptr_t)list[n-1]) + string_start;
2661 #if ENABLE_HUSH_BRACE_EXPANSION
2662 /* There in a GNU extension, GLOB_BRACE, but it is not usable:
2663 * first, it processes even {a} (no commas), second,
2664 * I didn't manage to make it return strings when they don't match
2665 * existing files. Need to re-implement it.
2669 static int glob_needed(const char *s)
2678 if (*s == '*' || *s == '[' || *s == '?' || *s == '{')
2684 /* Return pointer to next closing brace or to comma */
2685 static const char *next_brace_sub(const char *cp)
2689 while (*cp != '\0') {
2696 if ((*cp == '}' && depth-- == 0) || (*cp == ',' && depth == 0))
2702 return *cp != '\0' ? cp : NULL;
2704 /* Recursive brace globber. Note: may garble pattern[]. */
2705 static int glob_brace(char *pattern, o_string *o, int n)
2707 char *new_pattern_buf;
2714 debug_printf_glob("glob_brace('%s')\n", pattern);
2720 if (*begin == '{') {
2721 /* Find the first sub-pattern and at the same time
2722 * find the rest after the closing brace */
2723 next = next_brace_sub(begin);
2725 /* An illegal expression */
2729 /* "{abc}" with no commas - illegal
2730 * brace expr, disregard and skip it */
2736 if (*begin == '\\' && begin[1] != '\0')
2740 debug_printf_glob("begin:%s\n", begin);
2741 debug_printf_glob("next:%s\n", next);
2743 /* Now find the end of the whole brace expression */
2745 while (*rest != '}') {
2746 rest = next_brace_sub(rest);
2748 /* An illegal expression */
2751 debug_printf_glob("rest:%s\n", rest);
2753 rest_len = strlen(++rest) + 1;
2755 /* We are sure the brace expression is well-formed */
2757 /* Allocate working buffer large enough for our work */
2758 new_pattern_buf = xmalloc(strlen(pattern));
2760 /* We have a brace expression. BEGIN points to the opening {,
2761 * NEXT points past the terminator of the first element, and REST
2762 * points past the final }. We will accumulate result names from
2763 * recursive runs for each brace alternative in the buffer using
2768 /* Construct the new glob expression */
2771 mempcpy(new_pattern_buf,
2772 /* We know the prefix for all sub-patterns */
2773 pattern, begin - pattern),
2777 /* Note: glob_brace() may garble new_pattern_buf[].
2778 * That's why we re-copy prefix every time (1st memcpy above).
2780 n = glob_brace(new_pattern_buf, o, n);
2782 /* We saw the last entry */
2786 next = next_brace_sub(next);
2788 free(new_pattern_buf);
2796 memset(&globdata, 0, sizeof(globdata));
2797 gr = glob(pattern, 0, NULL, &globdata);
2798 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2800 if (gr == GLOB_NOMATCH) {
2801 globfree(&globdata);
2802 /* NB: garbles parameter */
2803 unbackslash(pattern);
2804 o_addstr_with_NUL(o, pattern);
2805 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2806 return o_save_ptr_helper(o, n);
2808 if (gr == GLOB_NOSPACE)
2809 bb_error_msg_and_die(bb_msg_memory_exhausted);
2810 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2811 * but we didn't specify it. Paranoia again. */
2812 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2814 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2815 char **argv = globdata.gl_pathv;
2817 o_addstr_with_NUL(o, *argv);
2818 n = o_save_ptr_helper(o, n);
2824 globfree(&globdata);
2828 /* Performs globbing on last list[],
2829 * saving each result as a new list[].
2831 static int perform_glob(o_string *o, int n)
2833 char *pattern, *copy;
2835 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2837 return o_save_ptr_helper(o, n);
2838 pattern = o->data + o_get_last_ptr(o, n);
2839 debug_printf_glob("glob pattern '%s'\n", pattern);
2840 if (!glob_needed(pattern)) {
2841 /* unbackslash last string in o in place, fix length */
2842 o->length = unbackslash(pattern) - o->data;
2843 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2844 return o_save_ptr_helper(o, n);
2847 copy = xstrdup(pattern);
2848 /* "forget" pattern in o */
2849 o->length = pattern - o->data;
2850 n = glob_brace(copy, o, n);
2853 debug_print_list("perform_glob returning", o, n);
2857 #else /* !HUSH_BRACE_EXPANSION */
2860 static int glob_needed(const char *s)
2869 if (*s == '*' || *s == '[' || *s == '?')
2875 /* Performs globbing on last list[],
2876 * saving each result as a new list[].
2878 static int perform_glob(o_string *o, int n)
2884 debug_printf_glob("start perform_glob: n:%d o->data:%p\n", n, o->data);
2886 return o_save_ptr_helper(o, n);
2887 pattern = o->data + o_get_last_ptr(o, n);
2888 debug_printf_glob("glob pattern '%s'\n", pattern);
2889 if (!glob_needed(pattern)) {
2891 /* unbackslash last string in o in place, fix length */
2892 o->length = unbackslash(pattern) - o->data;
2893 debug_printf_glob("glob pattern '%s' is literal\n", pattern);
2894 return o_save_ptr_helper(o, n);
2897 memset(&globdata, 0, sizeof(globdata));
2898 /* Can't use GLOB_NOCHECK: it does not unescape the string.
2899 * If we glob "*.\*" and don't find anything, we need
2900 * to fall back to using literal "*.*", but GLOB_NOCHECK
2901 * will return "*.\*"!
2903 gr = glob(pattern, 0, NULL, &globdata);
2904 debug_printf_glob("glob('%s'):%d\n", pattern, gr);
2906 if (gr == GLOB_NOMATCH) {
2907 globfree(&globdata);
2910 if (gr == GLOB_NOSPACE)
2911 bb_error_msg_and_die(bb_msg_memory_exhausted);
2912 /* GLOB_ABORTED? Only happens with GLOB_ERR flag,
2913 * but we didn't specify it. Paranoia again. */
2914 bb_error_msg_and_die("glob error %d on '%s'", gr, pattern);
2916 if (globdata.gl_pathv && globdata.gl_pathv[0]) {
2917 char **argv = globdata.gl_pathv;
2918 /* "forget" pattern in o */
2919 o->length = pattern - o->data;
2921 o_addstr_with_NUL(o, *argv);
2922 n = o_save_ptr_helper(o, n);
2928 globfree(&globdata);
2930 debug_print_list("perform_glob returning", o, n);
2934 #endif /* !HUSH_BRACE_EXPANSION */
2936 /* If o->o_expflags & EXP_FLAG_GLOB, glob the string so far remembered.
2937 * Otherwise, just finish current list[] and start new */
2938 static int o_save_ptr(o_string *o, int n)
2940 if (o->o_expflags & EXP_FLAG_GLOB) {
2941 /* If o->has_empty_slot, list[n] was already globbed
2942 * (if it was requested back then when it was filled)
2943 * so don't do that again! */
2944 if (!o->has_empty_slot)
2945 return perform_glob(o, n); /* o_save_ptr_helper is inside */
2947 return o_save_ptr_helper(o, n);
2950 /* "Please convert list[n] to real char* ptrs, and NULL terminate it." */
2951 static char **o_finalize_list(o_string *o, int n)
2956 n = o_save_ptr(o, n); /* force growth for list[n] if necessary */
2958 debug_print_list("finalized", o, n);
2959 debug_printf_expand("finalized n:%d\n", n);
2960 list = (char**)o->data;
2961 string_start = ((n + 0xf) & ~0xf) * sizeof(list[0]);
2965 list[n] = o->data + (int)(uintptr_t)list[n] + string_start;
2970 static void free_pipe_list(struct pipe *pi);
2972 /* Returns pi->next - next pipe in the list */
2973 static struct pipe *free_pipe(struct pipe *pi)
2978 debug_printf_clean("free_pipe (pid %d)\n", getpid());
2979 for (i = 0; i < pi->num_cmds; i++) {
2980 struct command *command;
2981 struct redir_struct *r, *rnext;
2983 command = &pi->cmds[i];
2984 debug_printf_clean(" command %d:\n", i);
2985 if (command->argv) {
2989 for (a = 0, p = command->argv; *p; a++, p++) {
2990 debug_printf_clean(" argv[%d] = %s\n", a, *p);
2993 free_strings(command->argv);
2994 //command->argv = NULL;
2996 /* not "else if": on syntax error, we may have both! */
2997 if (command->group) {
2998 debug_printf_clean(" begin group (cmd_type:%d)\n",
3000 free_pipe_list(command->group);
3001 debug_printf_clean(" end group\n");
3002 //command->group = NULL;
3004 /* else is crucial here.
3005 * If group != NULL, child_func is meaningless */
3006 #if ENABLE_HUSH_FUNCTIONS
3007 else if (command->child_func) {
3008 debug_printf_exec("cmd %p releases child func at %p\n", command, command->child_func);
3009 command->child_func->parent_cmd = NULL;
3013 free(command->group_as_string);
3014 //command->group_as_string = NULL;
3016 for (r = command->redirects; r; r = rnext) {
3017 debug_printf_clean(" redirect %d%s",
3018 r->rd_fd, redir_table[r->rd_type].descrip);
3019 /* guard against the case >$FOO, where foo is unset or blank */
3020 if (r->rd_filename) {
3021 debug_printf_clean(" fname:'%s'\n", r->rd_filename);
3022 free(r->rd_filename);
3023 //r->rd_filename = NULL;
3025 debug_printf_clean(" rd_dup:%d\n", r->rd_dup);
3029 //command->redirects = NULL;
3031 free(pi->cmds); /* children are an array, they get freed all at once */
3035 //pi->cmdtext = NULL;
3043 static void free_pipe_list(struct pipe *pi)
3047 debug_printf_clean("pipe reserved word %d\n", pi->res_word);
3049 debug_printf_clean("pipe followup code %d\n", pi->followup);
3055 /*** Parsing routines ***/
3057 #ifndef debug_print_tree
3058 static void debug_print_tree(struct pipe *pi, int lvl)
3060 static const char *const PIPE[] = {
3066 static const char *RES[] = {
3067 [RES_NONE ] = "NONE" ,
3070 [RES_THEN ] = "THEN" ,
3071 [RES_ELIF ] = "ELIF" ,
3072 [RES_ELSE ] = "ELSE" ,
3075 # if ENABLE_HUSH_LOOPS
3076 [RES_FOR ] = "FOR" ,
3077 [RES_WHILE] = "WHILE",
3078 [RES_UNTIL] = "UNTIL",
3080 [RES_DONE ] = "DONE" ,
3082 # if ENABLE_HUSH_LOOPS || ENABLE_HUSH_CASE
3085 # if ENABLE_HUSH_CASE
3086 [RES_CASE ] = "CASE" ,
3087 [RES_CASE_IN ] = "CASE_IN" ,
3088 [RES_MATCH] = "MATCH",
3089 [RES_CASE_BODY] = "CASE_BODY",
3090 [RES_ESAC ] = "ESAC" ,
3092 [RES_XXXX ] = "XXXX" ,
3093 [RES_SNTX ] = "SNTX" ,
3095 static const char *const CMDTYPE[] = {
3099 # if ENABLE_HUSH_FUNCTIONS
3108 fdprintf(2, "%*spipe %d res_word=%s followup=%d %s\n", lvl*2, "",
3109 pin, RES[pi->res_word], pi->followup, PIPE[pi->followup]);
3111 while (prn < pi->num_cmds) {
3112 struct command *command = &pi->cmds[prn];
3113 char **argv = command->argv;
3115 fdprintf(2, "%*s cmd %d assignment_cnt:%d",
3117 command->assignment_cnt);
3118 if (command->group) {
3119 fdprintf(2, " group %s: (argv=%p)%s%s\n",
3120 CMDTYPE[command->cmd_type],
3123 , " group_as_string:", command->group_as_string
3128 debug_print_tree(command->group, lvl+1);
3132 if (argv) while (*argv) {
3133 fdprintf(2, " '%s'", *argv);
3143 #endif /* debug_print_tree */
3145 static struct pipe *new_pipe(void)
3148 pi = xzalloc(sizeof(struct pipe));
3149 /*pi->res_word = RES_NONE; - RES_NONE is 0 anyway */
3153 /* Command (member of a pipe) is complete, or we start a new pipe
3154 * if ctx->command is NULL.
3155 * No errors possible here.
3157 static int done_command(struct parse_context *ctx)
3159 /* The command is really already in the pipe structure, so
3160 * advance the pipe counter and make a new, null command. */
3161 struct pipe *pi = ctx->pipe;
3162 struct command *command = ctx->command;
3164 #if 0 /* Instead we emit error message at run time */
3165 if (ctx->pending_redirect) {
3166 /* For example, "cmd >" (no filename to redirect to) */
3167 die_if_script("syntax error: %s", "invalid redirect");
3168 ctx->pending_redirect = NULL;
3173 if (IS_NULL_CMD(command)) {
3174 debug_printf_parse("done_command: skipping null cmd, num_cmds=%d\n", pi->num_cmds);
3178 debug_printf_parse("done_command: ++num_cmds=%d\n", pi->num_cmds);
3179 //debug_print_tree(ctx->list_head, 20);
3181 debug_printf_parse("done_command: initializing, num_cmds=%d\n", pi->num_cmds);
3184 /* Only real trickiness here is that the uncommitted
3185 * command structure is not counted in pi->num_cmds. */
3186 pi->cmds = xrealloc(pi->cmds, sizeof(*pi->cmds) * (pi->num_cmds+1));
3187 ctx->command = command = &pi->cmds[pi->num_cmds];
3189 memset(command, 0, sizeof(*command));
3190 return pi->num_cmds; /* used only for 0/nonzero check */
3193 static void done_pipe(struct parse_context *ctx, pipe_style type)
3197 debug_printf_parse("done_pipe entered, followup %d\n", type);
3198 /* Close previous command */
3199 not_null = done_command(ctx);
3200 ctx->pipe->followup = type;
3202 ctx->pipe->pi_inverted = ctx->ctx_inverted;
3203 ctx->ctx_inverted = 0;
3204 ctx->pipe->res_word = ctx->ctx_res_w;
3207 /* Without this check, even just <enter> on command line generates
3208 * tree of three NOPs (!). Which is harmless but annoying.
3209 * IOW: it is safe to do it unconditionally. */
3212 || ctx->ctx_res_w == RES_FI
3214 #if ENABLE_HUSH_LOOPS
3215 || ctx->ctx_res_w == RES_DONE
3216 || ctx->ctx_res_w == RES_FOR
3217 || ctx->ctx_res_w == RES_IN
3219 #if ENABLE_HUSH_CASE
3220 || ctx->ctx_res_w == RES_ESAC
3224 debug_printf_parse("done_pipe: adding new pipe: "
3225 "not_null:%d ctx->ctx_res_w:%d\n",
3226 not_null, ctx->ctx_res_w);
3228 ctx->pipe->next = new_p;
3230 /* RES_THEN, RES_DO etc are "sticky" -
3231 * they remain set for pipes inside if/while.
3232 * This is used to control execution.
3233 * RES_FOR and RES_IN are NOT sticky (needed to support
3234 * cases where variable or value happens to match a keyword):
3236 #if ENABLE_HUSH_LOOPS
3237 if (ctx->ctx_res_w == RES_FOR
3238 || ctx->ctx_res_w == RES_IN)
3239 ctx->ctx_res_w = RES_NONE;
3241 #if ENABLE_HUSH_CASE
3242 if (ctx->ctx_res_w == RES_MATCH)
3243 ctx->ctx_res_w = RES_CASE_BODY;
3244 if (ctx->ctx_res_w == RES_CASE)
3245 ctx->ctx_res_w = RES_CASE_IN;
3247 ctx->command = NULL; /* trick done_command below */
3248 /* Create the memory for command, roughly:
3249 * ctx->pipe->cmds = new struct command;
3250 * ctx->command = &ctx->pipe->cmds[0];
3253 //debug_print_tree(ctx->list_head, 10);
3255 debug_printf_parse("done_pipe return\n");
3258 static void initialize_context(struct parse_context *ctx)
3260 memset(ctx, 0, sizeof(*ctx));
3261 ctx->pipe = ctx->list_head = new_pipe();
3262 /* Create the memory for command, roughly:
3263 * ctx->pipe->cmds = new struct command;
3264 * ctx->command = &ctx->pipe->cmds[0];
3269 /* If a reserved word is found and processed, parse context is modified
3270 * and 1 is returned.
3273 struct reserved_combo {
3276 unsigned char assignment_flag;
3280 FLAG_END = (1 << RES_NONE ),
3282 FLAG_IF = (1 << RES_IF ),
3283 FLAG_THEN = (1 << RES_THEN ),
3284 FLAG_ELIF = (1 << RES_ELIF ),
3285 FLAG_ELSE = (1 << RES_ELSE ),
3286 FLAG_FI = (1 << RES_FI ),
3288 # if ENABLE_HUSH_LOOPS
3289 FLAG_FOR = (1 << RES_FOR ),
3290 FLAG_WHILE = (1 << RES_WHILE),
3291 FLAG_UNTIL = (1 << RES_UNTIL),
3292 FLAG_DO = (1 << RES_DO ),
3293 FLAG_DONE = (1 << RES_DONE ),
3294 FLAG_IN = (1 << RES_IN ),
3296 # if ENABLE_HUSH_CASE
3297 FLAG_MATCH = (1 << RES_MATCH),
3298 FLAG_ESAC = (1 << RES_ESAC ),
3300 FLAG_START = (1 << RES_XXXX ),
3303 static const struct reserved_combo* match_reserved_word(o_string *word)
3305 /* Mostly a list of accepted follow-up reserved words.
3306 * FLAG_END means we are done with the sequence, and are ready
3307 * to turn the compound list into a command.
3308 * FLAG_START means the word must start a new compound list.
3310 static const struct reserved_combo reserved_list[] = {
3312 { "!", RES_NONE, NOT_ASSIGNMENT , 0 },
3313 { "if", RES_IF, MAYBE_ASSIGNMENT, FLAG_THEN | FLAG_START },
3314 { "then", RES_THEN, MAYBE_ASSIGNMENT, FLAG_ELIF | FLAG_ELSE | FLAG_FI },
3315 { "elif", RES_ELIF, MAYBE_ASSIGNMENT, FLAG_THEN },
3316 { "else", RES_ELSE, MAYBE_ASSIGNMENT, FLAG_FI },
3317 { "fi", RES_FI, NOT_ASSIGNMENT , FLAG_END },
3319 # if ENABLE_HUSH_LOOPS
3320 { "for", RES_FOR, NOT_ASSIGNMENT , FLAG_IN | FLAG_DO | FLAG_START },
3321 { "while", RES_WHILE, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3322 { "until", RES_UNTIL, MAYBE_ASSIGNMENT, FLAG_DO | FLAG_START },
3323 { "in", RES_IN, NOT_ASSIGNMENT , FLAG_DO },
3324 { "do", RES_DO, MAYBE_ASSIGNMENT, FLAG_DONE },
3325 { "done", RES_DONE, NOT_ASSIGNMENT , FLAG_END },
3327 # if ENABLE_HUSH_CASE
3328 { "case", RES_CASE, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_START },
3329 { "esac", RES_ESAC, NOT_ASSIGNMENT , FLAG_END },
3332 const struct reserved_combo *r;
3334 for (r = reserved_list; r < reserved_list + ARRAY_SIZE(reserved_list); r++) {
3335 if (strcmp(word->data, r->literal) == 0)
3340 /* Return 0: not a keyword, 1: keyword
3342 static int reserved_word(o_string *word, struct parse_context *ctx)
3344 # if ENABLE_HUSH_CASE
3345 static const struct reserved_combo reserved_match = {
3346 "", RES_MATCH, NOT_ASSIGNMENT , FLAG_MATCH | FLAG_ESAC
3349 const struct reserved_combo *r;
3351 if (word->has_quoted_part)
3353 r = match_reserved_word(word);
3357 debug_printf("found reserved word %s, res %d\n", r->literal, r->res);
3358 # if ENABLE_HUSH_CASE
3359 if (r->res == RES_IN && ctx->ctx_res_w == RES_CASE_IN) {
3360 /* "case word IN ..." - IN part starts first MATCH part */
3361 r = &reserved_match;
3364 if (r->flag == 0) { /* '!' */
3365 if (ctx->ctx_inverted) { /* bash doesn't accept '! ! true' */
3366 syntax_error("! ! command");
3367 ctx->ctx_res_w = RES_SNTX;
3369 ctx->ctx_inverted = 1;
3372 if (r->flag & FLAG_START) {
3373 struct parse_context *old;
3375 old = xmalloc(sizeof(*old));
3376 debug_printf_parse("push stack %p\n", old);
3377 *old = *ctx; /* physical copy */
3378 initialize_context(ctx);
3380 } else if (/*ctx->ctx_res_w == RES_NONE ||*/ !(ctx->old_flag & (1 << r->res))) {
3381 syntax_error_at(word->data);
3382 ctx->ctx_res_w = RES_SNTX;
3385 /* "{...} fi" is ok. "{...} if" is not
3387 * if { echo foo; } then { echo bar; } fi */
3388 if (ctx->command->group)
3389 done_pipe(ctx, PIPE_SEQ);
3392 ctx->ctx_res_w = r->res;
3393 ctx->old_flag = r->flag;
3394 word->o_assignment = r->assignment_flag;
3395 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3397 if (ctx->old_flag & FLAG_END) {
3398 struct parse_context *old;
3400 done_pipe(ctx, PIPE_SEQ);
3401 debug_printf_parse("pop stack %p\n", ctx->stack);
3403 old->command->group = ctx->list_head;
3404 old->command->cmd_type = CMD_NORMAL;
3406 /* At this point, the compound command's string is in
3407 * ctx->as_string... except for the leading keyword!
3408 * Consider this example: "echo a | if true; then echo a; fi"
3409 * ctx->as_string will contain "true; then echo a; fi",
3410 * with "if " remaining in old->as_string!
3414 int len = old->as_string.length;
3415 /* Concatenate halves */
3416 o_addstr(&old->as_string, ctx->as_string.data);
3417 o_free_unsafe(&ctx->as_string);
3418 /* Find where leading keyword starts in first half */
3419 str = old->as_string.data + len;
3420 if (str > old->as_string.data)
3421 str--; /* skip whitespace after keyword */
3422 while (str > old->as_string.data && isalpha(str[-1]))
3424 /* Ugh, we're done with this horrid hack */
3425 old->command->group_as_string = xstrdup(str);
3426 debug_printf_parse("pop, remembering as:'%s'\n",
3427 old->command->group_as_string);
3430 *ctx = *old; /* physical copy */
3435 #endif /* HAS_KEYWORDS */
3437 /* Word is complete, look at it and update parsing context.
3438 * Normal return is 0. Syntax errors return 1.
3439 * Note: on return, word is reset, but not o_free'd!
3441 static int done_word(o_string *word, struct parse_context *ctx)
3443 struct command *command = ctx->command;
3445 debug_printf_parse("done_word entered: '%s' %p\n", word->data, command);
3446 if (word->length == 0 && !word->has_quoted_part) {
3447 debug_printf_parse("done_word return 0: true null, ignored\n");
3451 if (ctx->pending_redirect) {
3452 /* We do not glob in e.g. >*.tmp case. bash seems to glob here
3453 * only if run as "bash", not "sh" */
3454 /* http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3456 * ...the word that follows the redirection operator
3457 * shall be subjected to tilde expansion, parameter expansion,
3458 * command substitution, arithmetic expansion, and quote
3459 * removal. Pathname expansion shall not be performed
3460 * on the word by a non-interactive shell; an interactive
3461 * shell may perform it, but shall do so only when
3462 * the expansion would result in one word."
3464 ctx->pending_redirect->rd_filename = xstrdup(word->data);
3465 /* Cater for >\file case:
3466 * >\a creates file a; >\\a, >"\a", >"\\a" create file \a
3467 * Same with heredocs:
3468 * for <<\H delim is H; <<\\H, <<"\H", <<"\\H" - \H
3470 if (ctx->pending_redirect->rd_type == REDIRECT_HEREDOC) {
3471 unbackslash(ctx->pending_redirect->rd_filename);
3472 /* Is it <<"HEREDOC"? */
3473 if (word->has_quoted_part) {
3474 ctx->pending_redirect->rd_dup |= HEREDOC_QUOTED;
3477 debug_printf_parse("word stored in rd_filename: '%s'\n", word->data);
3478 ctx->pending_redirect = NULL;
3481 # if ENABLE_HUSH_CASE
3482 if (ctx->ctx_dsemicolon
3483 && strcmp(word->data, "esac") != 0 /* not "... pattern) cmd;; esac" */
3485 /* already done when ctx_dsemicolon was set to 1: */
3486 /* ctx->ctx_res_w = RES_MATCH; */
3487 ctx->ctx_dsemicolon = 0;
3490 if (!command->argv /* if it's the first word... */
3491 # if ENABLE_HUSH_LOOPS
3492 && ctx->ctx_res_w != RES_FOR /* ...not after FOR or IN */
3493 && ctx->ctx_res_w != RES_IN
3495 # if ENABLE_HUSH_CASE
3496 && ctx->ctx_res_w != RES_CASE
3499 int reserved = reserved_word(word, ctx);
3500 debug_printf_parse("checking for reserved-ness: %d\n", reserved);
3502 o_reset_to_empty_unquoted(word);
3503 debug_printf_parse("done_word return %d\n",
3504 (ctx->ctx_res_w == RES_SNTX));
3505 return (ctx->ctx_res_w == RES_SNTX);
3507 # if ENABLE_HUSH_BASH_COMPAT
3508 if (strcmp(word->data, "[[") == 0) {
3509 command->cmd_type = CMD_SINGLEWORD_NOGLOB;
3515 if (command->group) {
3516 /* "{ echo foo; } echo bar" - bad */
3517 syntax_error_at(word->data);
3518 debug_printf_parse("done_word return 1: syntax error, "
3519 "groups and arglists don't mix\n");
3523 /* If this word wasn't an assignment, next ones definitely
3524 * can't be assignments. Even if they look like ones. */
3525 if (word->o_assignment != DEFINITELY_ASSIGNMENT
3526 && word->o_assignment != WORD_IS_KEYWORD
3528 word->o_assignment = NOT_ASSIGNMENT;
3530 if (word->o_assignment == DEFINITELY_ASSIGNMENT) {
3531 command->assignment_cnt++;
3532 debug_printf_parse("++assignment_cnt=%d\n", command->assignment_cnt);
3534 debug_printf_parse("word->o_assignment was:'%s'\n", assignment_flag[word->o_assignment]);
3535 word->o_assignment = MAYBE_ASSIGNMENT;
3537 debug_printf_parse("word->o_assignment='%s'\n", assignment_flag[word->o_assignment]);
3539 if (word->has_quoted_part
3540 /* optimization: and if it's ("" or '') or ($v... or `cmd`...): */
3541 && (word->data[0] == '\0' || word->data[0] == SPECIAL_VAR_SYMBOL)
3542 /* (otherwise it's known to be not empty and is already safe) */
3544 /* exclude "$@" - it can expand to no word despite "" */
3545 char *p = word->data;
3546 while (p[0] == SPECIAL_VAR_SYMBOL
3547 && (p[1] & 0x7f) == '@'
3548 && p[2] == SPECIAL_VAR_SYMBOL
3553 command->argv = add_string_to_strings(command->argv, xstrdup(word->data));
3554 debug_print_strings("word appended to argv", command->argv);
3557 #if ENABLE_HUSH_LOOPS
3558 if (ctx->ctx_res_w == RES_FOR) {
3559 if (word->has_quoted_part
3560 || !is_well_formed_var_name(command->argv[0], '\0')
3562 /* bash says just "not a valid identifier" */
3563 syntax_error("not a valid identifier in for");
3566 /* Force FOR to have just one word (variable name) */
3567 /* NB: basically, this makes hush see "for v in ..."
3568 * syntax as if it is "for v; in ...". FOR and IN become
3569 * two pipe structs in parse tree. */
3570 done_pipe(ctx, PIPE_SEQ);
3573 #if ENABLE_HUSH_CASE
3574 /* Force CASE to have just one word */
3575 if (ctx->ctx_res_w == RES_CASE) {
3576 done_pipe(ctx, PIPE_SEQ);
3580 o_reset_to_empty_unquoted(word);
3582 debug_printf_parse("done_word return 0\n");
3587 /* Peek ahead in the input to find out if we have a "&n" construct,
3588 * as in "2>&1", that represents duplicating a file descriptor.
3590 * REDIRFD_CLOSE if >&- "close fd" construct is seen,
3591 * REDIRFD_SYNTAX_ERR if syntax error,
3592 * REDIRFD_TO_FILE if no & was seen,
3593 * or the number found.
3596 #define parse_redir_right_fd(as_string, input) \
3597 parse_redir_right_fd(input)
3599 static int parse_redir_right_fd(o_string *as_string, struct in_str *input)
3605 return REDIRFD_TO_FILE;
3607 ch = i_getch(input); /* get the & */
3608 nommu_addchr(as_string, ch);
3611 ch = i_getch(input);
3612 nommu_addchr(as_string, ch);
3613 return REDIRFD_CLOSE;
3617 while (ch != EOF && isdigit(ch)) {
3618 d = d*10 + (ch-'0');
3620 ch = i_getch(input);
3621 nommu_addchr(as_string, ch);
3626 //TODO: this is the place to catch ">&file" bashism (redirect both fd 1 and 2)
3628 bb_error_msg("ambiguous redirect");
3629 return REDIRFD_SYNTAX_ERR;
3632 /* Return code is 0 normal, 1 if a syntax error is detected
3634 static int parse_redirect(struct parse_context *ctx,
3637 struct in_str *input)
3639 struct command *command = ctx->command;
3640 struct redir_struct *redir;
3641 struct redir_struct **redirp;
3644 dup_num = REDIRFD_TO_FILE;
3645 if (style != REDIRECT_HEREDOC) {
3646 /* Check for a '>&1' type redirect */
3647 dup_num = parse_redir_right_fd(&ctx->as_string, input);
3648 if (dup_num == REDIRFD_SYNTAX_ERR)
3651 int ch = i_peek(input);
3652 dup_num = (ch == '-'); /* HEREDOC_SKIPTABS bit is 1 */
3653 if (dup_num) { /* <<-... */
3654 ch = i_getch(input);
3655 nommu_addchr(&ctx->as_string, ch);
3660 if (style == REDIRECT_OVERWRITE && dup_num == REDIRFD_TO_FILE) {
3661 int ch = i_peek(input);
3663 /* >|FILE redirect ("clobbering" >).
3664 * Since we do not support "set -o noclobber" yet,
3665 * >| and > are the same for now. Just eat |.
3667 ch = i_getch(input);
3668 nommu_addchr(&ctx->as_string, ch);
3672 /* Create a new redir_struct and append it to the linked list */
3673 redirp = &command->redirects;
3674 while ((redir = *redirp) != NULL) {
3675 redirp = &(redir->next);
3677 *redirp = redir = xzalloc(sizeof(*redir));
3678 /* redir->next = NULL; */
3679 /* redir->rd_filename = NULL; */
3680 redir->rd_type = style;
3681 redir->rd_fd = (fd == -1) ? redir_table[style].default_fd : fd;
3683 debug_printf_parse("redirect type %d %s\n", redir->rd_fd,
3684 redir_table[style].descrip);
3686 redir->rd_dup = dup_num;
3687 if (style != REDIRECT_HEREDOC && dup_num != REDIRFD_TO_FILE) {
3688 /* Erik had a check here that the file descriptor in question
3689 * is legit; I postpone that to "run time"
3690 * A "-" representation of "close me" shows up as a -3 here */
3691 debug_printf_parse("duplicating redirect '%d>&%d'\n",
3692 redir->rd_fd, redir->rd_dup);
3694 #if 0 /* Instead we emit error message at run time */
3695 if (ctx->pending_redirect) {
3696 /* For example, "cmd > <file" */
3697 die_if_script("syntax error: %s", "invalid redirect");
3700 /* Set ctx->pending_redirect, so we know what to do at the
3701 * end of the next parsed word. */
3702 ctx->pending_redirect = redir;
3707 /* If a redirect is immediately preceded by a number, that number is
3708 * supposed to tell which file descriptor to redirect. This routine
3709 * looks for such preceding numbers. In an ideal world this routine
3710 * needs to handle all the following classes of redirects...
3711 * echo 2>foo # redirects fd 2 to file "foo", nothing passed to echo
3712 * echo 49>foo # redirects fd 49 to file "foo", nothing passed to echo
3713 * echo -2>foo # redirects fd 1 to file "foo", "-2" passed to echo
3714 * echo 49x>foo # redirects fd 1 to file "foo", "49x" passed to echo
3716 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html
3718 * ... If n is quoted, the number shall not be recognized as part of
3719 * the redirection expression. For example:
3721 * writes the character 2 into file a"
3722 * We are getting it right by setting ->has_quoted_part on any \<char>
3724 * A -1 return means no valid number was found,
3725 * the caller should use the appropriate default for this redirection.
3727 static int redirect_opt_num(o_string *o)
3731 if (o->data == NULL)
3733 num = bb_strtou(o->data, NULL, 10);
3734 if (errno || num < 0)
3736 o_reset_to_empty_unquoted(o);
3741 #define fetch_till_str(as_string, input, word, skip_tabs) \
3742 fetch_till_str(input, word, skip_tabs)
3744 static char *fetch_till_str(o_string *as_string,
3745 struct in_str *input,
3749 o_string heredoc = NULL_O_STRING;
3751 int prev = 0; /* not \ */
3757 ch = i_getch(input);
3759 nommu_addchr(as_string, ch);
3760 if ((ch == '\n' || ch == EOF)
3761 && ((heredoc_flags & HEREDOC_QUOTED) || prev != '\\')
3763 if (strcmp(heredoc.data + past_EOL, word) == 0) {
3764 heredoc.data[past_EOL] = '\0';
3765 debug_printf_parse("parsed heredoc '%s'\n", heredoc.data);
3766 return heredoc.data;
3768 while (ch == '\n') {
3769 o_addchr(&heredoc, ch);
3772 past_EOL = heredoc.length;
3774 ch = i_getch(input);
3776 nommu_addchr(as_string, ch);
3777 } while ((heredoc_flags & HEREDOC_SKIPTABS) && ch == '\t');
3781 o_free_unsafe(&heredoc);
3784 o_addchr(&heredoc, ch);
3785 nommu_addchr(as_string, ch);
3786 if (prev == '\\' && ch == '\\')
3787 /* Correctly handle foo\\<eol> (not a line cont.) */
3788 prev = 0; /* not \ */
3794 /* Look at entire parse tree for not-yet-loaded REDIRECT_HEREDOCs
3795 * and load them all. There should be exactly heredoc_cnt of them.
3797 static int fetch_heredocs(int heredoc_cnt, struct parse_context *ctx, struct in_str *input)
3799 struct pipe *pi = ctx->list_head;
3801 while (pi && heredoc_cnt) {
3803 struct command *cmd = pi->cmds;
3805 debug_printf_parse("fetch_heredocs: num_cmds:%d cmd argv0:'%s'\n",
3807 cmd->argv ? cmd->argv[0] : "NONE");
3808 for (i = 0; i < pi->num_cmds; i++) {
3809 struct redir_struct *redir = cmd->redirects;
3811 debug_printf_parse("fetch_heredocs: %d cmd argv0:'%s'\n",
3812 i, cmd->argv ? cmd->argv[0] : "NONE");
3814 if (redir->rd_type == REDIRECT_HEREDOC) {
3817 redir->rd_type = REDIRECT_HEREDOC2;
3818 /* redir->rd_dup is (ab)used to indicate <<- */
3819 p = fetch_till_str(&ctx->as_string, input,
3820 redir->rd_filename, redir->rd_dup);
3822 syntax_error("unexpected EOF in here document");
3825 free(redir->rd_filename);
3826 redir->rd_filename = p;
3829 redir = redir->next;
3836 /* Should be 0. If it isn't, it's a parse error */
3838 bb_error_msg_and_die("heredoc BUG 2");
3844 static int run_list(struct pipe *pi);
3846 #define parse_stream(pstring, input, end_trigger) \
3847 parse_stream(input, end_trigger)
3849 static struct pipe *parse_stream(char **pstring,
3850 struct in_str *input,
3854 #if !ENABLE_HUSH_FUNCTIONS
3855 #define parse_group(dest, ctx, input, ch) \
3856 parse_group(ctx, input, ch)
3858 static int parse_group(o_string *dest, struct parse_context *ctx,
3859 struct in_str *input, int ch)
3861 /* dest contains characters seen prior to ( or {.
3862 * Typically it's empty, but for function defs,
3863 * it contains function name (without '()'). */
3864 struct pipe *pipe_list;
3866 struct command *command = ctx->command;
3868 debug_printf_parse("parse_group entered\n");
3869 #if ENABLE_HUSH_FUNCTIONS
3870 if (ch == '(' && !dest->has_quoted_part) {
3872 if (done_word(dest, ctx))
3875 goto skip; /* (... */
3876 if (command->argv[1]) { /* word word ... (... */
3877 syntax_error_unexpected_ch('(');
3880 /* it is "word(..." or "word (..." */
3882 ch = i_getch(input);
3883 while (ch == ' ' || ch == '\t');
3885 syntax_error_unexpected_ch(ch);
3888 nommu_addchr(&ctx->as_string, ch);
3890 ch = i_getch(input);
3891 while (ch == ' ' || ch == '\t' || ch == '\n');
3893 syntax_error_unexpected_ch(ch);
3896 nommu_addchr(&ctx->as_string, ch);
3897 command->cmd_type = CMD_FUNCDEF;
3902 #if 0 /* Prevented by caller */
3903 if (command->argv /* word [word]{... */
3904 || dest->length /* word{... */
3905 || dest->has_quoted_part /* ""{... */
3908 debug_printf_parse("parse_group return 1: "
3909 "syntax error, groups and arglists don't mix\n");
3914 #if ENABLE_HUSH_FUNCTIONS
3920 command->cmd_type = CMD_SUBSHELL;
3922 /* bash does not allow "{echo...", requires whitespace */
3924 if (ch != ' ' && ch != '\t' && ch != '\n'
3925 && ch != '(' /* but "{(..." is allowed (without whitespace) */
3927 syntax_error_unexpected_ch(ch);
3931 ch = i_getch(input);
3932 nommu_addchr(&ctx->as_string, ch);
3938 # define as_string NULL
3940 char *as_string = NULL;
3942 pipe_list = parse_stream(&as_string, input, endch);
3945 o_addstr(&ctx->as_string, as_string);
3947 /* empty ()/{} or parse error? */
3948 if (!pipe_list || pipe_list == ERR_PTR) {
3949 /* parse_stream already emitted error msg */
3952 debug_printf_parse("parse_group return 1: "
3953 "parse_stream returned %p\n", pipe_list);
3956 command->group = pipe_list;
3958 as_string[strlen(as_string) - 1] = '\0'; /* plink ')' or '}' */
3959 command->group_as_string = as_string;
3960 debug_printf_parse("end of group, remembering as:'%s'\n",
3961 command->group_as_string);
3965 debug_printf_parse("parse_group return 0\n");
3967 /* command remains "open", available for possible redirects */
3970 static int i_getch_and_eat_bkslash_nl(struct in_str *input)
3975 ch = i_getch(input);
3978 ch2 = i_peek(input);
3981 /* backslash+newline, skip it */
3986 static int i_peek_and_eat_bkslash_nl(struct in_str *input)
3994 ch2 = i_peek2(input);
3997 /* backslash+newline, skip it */
4003 #if ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS
4004 /* Subroutines for copying $(...) and `...` things */
4005 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote);
4007 static int add_till_single_quote(o_string *dest, struct in_str *input)
4010 int ch = i_getch(input);
4012 syntax_error_unterm_ch('\'');
4020 /* "...\"...`..`...." - do we need to handle "...$(..)..." too? */
4021 static int add_till_double_quote(o_string *dest, struct in_str *input)
4024 int ch = i_getch(input);
4026 syntax_error_unterm_ch('"');
4031 if (ch == '\\') { /* \x. Copy both chars. */
4033 ch = i_getch(input);
4037 if (!add_till_backquote(dest, input, /*in_dquote:*/ 1))
4042 //if (ch == '$') ...
4045 /* Process `cmd` - copy contents until "`" is seen. Complicated by
4047 * "Within the backquoted style of command substitution, backslash
4048 * shall retain its literal meaning, except when followed by: '$', '`', or '\'.
4049 * The search for the matching backquote shall be satisfied by the first
4050 * backquote found without a preceding backslash; during this search,
4051 * if a non-escaped backquote is encountered within a shell comment,
4052 * a here-document, an embedded command substitution of the $(command)
4053 * form, or a quoted string, undefined results occur. A single-quoted
4054 * or double-quoted string that begins, but does not end, within the
4055 * "`...`" sequence produces undefined results."
4057 * echo `echo '\'TEST\`echo ZZ\`BEST` \TESTZZBEST
4059 static int add_till_backquote(o_string *dest, struct in_str *input, int in_dquote)
4062 int ch = i_getch(input);
4066 /* \x. Copy both unless it is \`, \$, \\ and maybe \" */
4067 ch = i_getch(input);
4071 && (!in_dquote || ch != '"')
4073 o_addchr(dest, '\\');
4077 syntax_error_unterm_ch('`');
4083 /* Process $(cmd) - copy contents until ")" is seen. Complicated by
4084 * quoting and nested ()s.
4085 * "With the $(command) style of command substitution, all characters
4086 * following the open parenthesis to the matching closing parenthesis
4087 * constitute the command. Any valid shell script can be used for command,
4088 * except a script consisting solely of redirections which produces
4089 * unspecified results."
4091 * echo $(echo '(TEST)' BEST) (TEST) BEST
4092 * echo $(echo 'TEST)' BEST) TEST) BEST
4093 * echo $(echo \(\(TEST\) BEST) ((TEST) BEST
4095 * Also adapted to eat ${var%...} and $((...)) constructs, since ... part
4096 * can contain arbitrary constructs, just like $(cmd).
4097 * In bash compat mode, it needs to also be able to stop on ':' or '/'
4098 * for ${var:N[:M]} and ${var/P[/R]} parsing.
4100 #define DOUBLE_CLOSE_CHAR_FLAG 0x80
4101 static int add_till_closing_bracket(o_string *dest, struct in_str *input, unsigned end_ch)
4104 char dbl = end_ch & DOUBLE_CLOSE_CHAR_FLAG;
4105 # if ENABLE_HUSH_BASH_COMPAT
4106 char end_char2 = end_ch >> 8;
4108 end_ch &= (DOUBLE_CLOSE_CHAR_FLAG - 1);
4111 ch = i_getch(input);
4113 syntax_error_unterm_ch(end_ch);
4116 if (ch == end_ch IF_HUSH_BASH_COMPAT( || ch == end_char2)) {
4119 /* we look for closing )) of $((EXPR)) */
4120 if (i_peek_and_eat_bkslash_nl(input) == end_ch) {
4121 i_getch(input); /* eat second ')' */
4126 if (ch == '(' || ch == '{') {
4127 ch = (ch == '(' ? ')' : '}');
4128 if (!add_till_closing_bracket(dest, input, ch))
4134 if (!add_till_single_quote(dest, input))
4140 if (!add_till_double_quote(dest, input))
4146 if (!add_till_backquote(dest, input, /*in_dquote:*/ 0))
4152 /* \x. Copy verbatim. Important for \(, \) */
4153 ch = i_getch(input);
4155 syntax_error_unterm_ch(')');
4160 /* "backslash+newline", ignore both */
4161 o_delchr(dest); /* undo insertion of '\' */
4171 #endif /* ENABLE_HUSH_TICK || ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_DOLLAR_OPS */
4173 /* Return code: 0 for OK, 1 for syntax error */
4175 #define parse_dollar(as_string, dest, input, quote_mask) \
4176 parse_dollar(dest, input, quote_mask)
4177 #define as_string NULL
4179 static int parse_dollar(o_string *as_string,
4181 struct in_str *input, unsigned char quote_mask)
4183 int ch = i_peek_and_eat_bkslash_nl(input); /* first character after the $ */
4185 debug_printf_parse("parse_dollar entered: ch='%c'\n", ch);
4187 ch = i_getch(input);
4188 nommu_addchr(as_string, ch);
4190 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4192 debug_printf_parse(": '%c'\n", ch);
4193 o_addchr(dest, ch | quote_mask);
4195 ch = i_peek_and_eat_bkslash_nl(input);
4196 if (!isalnum(ch) && ch != '_') {
4197 /* End of variable name reached */
4200 ch = i_getch(input);
4201 nommu_addchr(as_string, ch);
4203 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4204 } else if (isdigit(ch)) {
4206 ch = i_getch(input);
4207 nommu_addchr(as_string, ch);
4208 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4209 debug_printf_parse(": '%c'\n", ch);
4210 o_addchr(dest, ch | quote_mask);
4211 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4212 } else switch (ch) {
4214 case '!': /* last bg pid */
4215 case '?': /* last exit code */
4216 case '#': /* number of args */
4217 case '*': /* args */
4218 case '@': /* args */
4219 goto make_one_char_var;
4221 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4223 ch = i_getch(input); /* eat '{' */
4224 nommu_addchr(as_string, ch);
4226 ch = i_getch_and_eat_bkslash_nl(input); /* first char after '{' */
4227 /* It should be ${?}, or ${#var},
4228 * or even ${?+subst} - operator acting on a special variable,
4229 * or the beginning of variable name.
4232 || (!strchr(_SPECIAL_VARS_STR, ch) && !isalnum(ch)) /* not one of those */
4235 syntax_error_unterm_str("${name}");
4236 debug_printf_parse("parse_dollar return 0: unterminated ${name}\n");
4239 nommu_addchr(as_string, ch);
4242 /* It's possible to just call add_till_closing_bracket() at this point.
4243 * However, this regresses some of our testsuite cases
4244 * which check invalid constructs like ${%}.
4245 * Oh well... let's check that the var name part is fine... */
4251 debug_printf_parse(": '%c'\n", ch);
4253 ch = i_getch(input);
4254 nommu_addchr(as_string, ch);
4258 if (!isalnum(ch) && ch != '_') {
4260 unsigned char last_ch;
4261 /* handle parameter expansions
4262 * http://www.opengroup.org/onlinepubs/009695399/utilities/xcu_chap02.html#tag_02_06_02
4264 if (!strchr(VAR_SUBST_OPS, ch)) /* ${var<bad_char>... */
4265 goto bad_dollar_syntax;
4267 /* Eat everything until closing '}' (or ':') */
4269 if (ENABLE_HUSH_BASH_COMPAT
4271 && !strchr(MINUS_PLUS_EQUAL_QUESTION, i_peek(input))
4273 /* It's ${var:N[:M]} thing */
4274 end_ch = '}' * 0x100 + ':';
4276 if (ENABLE_HUSH_BASH_COMPAT
4279 /* It's ${var/[/]pattern[/repl]} thing */
4280 if (i_peek(input) == '/') { /* ${var//pattern[/repl]}? */
4282 nommu_addchr(as_string, '/');
4285 end_ch = '}' * 0x100 + '/';
4291 #if ENABLE_HUSH_DOLLAR_OPS
4292 last_ch = add_till_closing_bracket(dest, input, end_ch);
4293 if (last_ch == 0) /* error? */
4296 #error Simple code to only allow ${var} is not implemented
4299 o_addstr(as_string, dest->data + pos);
4300 o_addchr(as_string, last_ch);
4303 if (ENABLE_HUSH_BASH_COMPAT && (end_ch & 0xff00)) {
4304 /* close the first block: */
4305 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4306 /* while parsing N from ${var:N[:M]}
4307 * or pattern from ${var/[/]pattern[/repl]} */
4308 if ((end_ch & 0xff) == last_ch) {
4309 /* got ':' or '/'- parse the rest */
4314 if (end_ch == '}' * 0x100 + ':') {
4315 /* it's ${var:N} - emulate :999999999 */
4316 o_addstr(dest, "999999999");
4317 } /* else: it's ${var/[/]pattern} */
4322 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4325 #if ENABLE_FEATURE_SH_MATH || ENABLE_HUSH_TICK
4329 ch = i_getch(input);
4330 nommu_addchr(as_string, ch);
4331 # if ENABLE_FEATURE_SH_MATH
4332 if (i_peek_and_eat_bkslash_nl(input) == '(') {
4333 ch = i_getch(input);
4334 nommu_addchr(as_string, ch);
4335 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4336 o_addchr(dest, /*quote_mask |*/ '+');
4339 if (!add_till_closing_bracket(dest, input, ')' | DOUBLE_CLOSE_CHAR_FLAG))
4340 return 0; /* error */
4342 o_addstr(as_string, dest->data + pos);
4343 o_addchr(as_string, ')');
4344 o_addchr(as_string, ')');
4346 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4350 # if ENABLE_HUSH_TICK
4351 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4352 o_addchr(dest, quote_mask | '`');
4355 if (!add_till_closing_bracket(dest, input, ')'))
4356 return 0; /* error */
4358 o_addstr(as_string, dest->data + pos);
4359 o_addchr(as_string, ')');
4361 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4367 ch = i_getch(input);
4368 nommu_addchr(as_string, ch);
4369 ch = i_peek_and_eat_bkslash_nl(input);
4370 if (isalnum(ch)) { /* it's $_name or $_123 */
4375 /* TODO: $_ and $-: */
4376 /* $_ Shell or shell script name; or last argument of last command
4377 * (if last command wasn't a pipe; if it was, bash sets $_ to "");
4378 * but in command's env, set to full pathname used to invoke it */
4379 /* $- Option flags set by set builtin or shell options (-i etc) */
4381 o_addQchr(dest, '$');
4383 debug_printf_parse("parse_dollar return 1 (ok)\n");
4389 # if ENABLE_HUSH_BASH_COMPAT
4390 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4391 encode_string(dest, input, dquote_end, process_bkslash)
4393 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
4394 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4395 encode_string(dest, input, dquote_end)
4397 #define as_string NULL
4401 # if ENABLE_HUSH_BASH_COMPAT
4402 /* all parameters are needed, no macro tricks */
4404 #define encode_string(as_string, dest, input, dquote_end, process_bkslash) \
4405 encode_string(as_string, dest, input, dquote_end)
4408 static int encode_string(o_string *as_string,
4410 struct in_str *input,
4412 int process_bkslash)
4414 #if !ENABLE_HUSH_BASH_COMPAT
4415 const int process_bkslash = 1;
4421 ch = i_getch(input);
4423 nommu_addchr(as_string, ch);
4424 if (ch == dquote_end) { /* may be only '"' or EOF */
4425 debug_printf_parse("encode_string return 1 (ok)\n");
4428 /* note: can't move it above ch == dquote_end check! */
4430 syntax_error_unterm_ch('"');
4431 return 0; /* error */
4435 next = i_peek(input);
4437 debug_printf_parse("\" ch=%c (%d) escape=%d\n",
4438 ch, ch, !!(dest->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4439 if (process_bkslash && ch == '\\') {
4441 syntax_error("\\<eof>");
4445 * "The backslash retains its special meaning [in "..."]
4446 * only when followed by one of the following characters:
4447 * $, `, ", \, or <newline>. A double quote may be quoted
4448 * within double quotes by preceding it with a backslash."
4449 * NB: in (unquoted) heredoc, above does not apply to ",
4450 * therefore we check for it by "next == dquote_end" cond.
4452 if (next == dquote_end || strchr("$`\\\n", next)) {
4453 ch = i_getch(input); /* eat next */
4455 goto again; /* skip \<newline> */
4456 } /* else: ch remains == '\\', and we double it below: */
4457 o_addqchr(dest, ch); /* \c if c is a glob char, else just c */
4458 nommu_addchr(as_string, ch);
4462 if (!parse_dollar(as_string, dest, input, /*quote_mask:*/ 0x80)) {
4463 debug_printf_parse("encode_string return 0: "
4464 "parse_dollar returned 0 (error)\n");
4469 #if ENABLE_HUSH_TICK
4471 //unsigned pos = dest->length;
4472 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4473 o_addchr(dest, 0x80 | '`');
4474 if (!add_till_backquote(dest, input, /*in_dquote:*/ dquote_end == '"'))
4475 return 0; /* error */
4476 o_addchr(dest, SPECIAL_VAR_SYMBOL);
4477 //debug_printf_subst("SUBST RES3 '%s'\n", dest->data + pos);
4481 o_addQchr(dest, ch);
4487 * Scan input until EOF or end_trigger char.
4488 * Return a list of pipes to execute, or NULL on EOF
4489 * or if end_trigger character is met.
4490 * On syntax error, exit if shell is not interactive,
4491 * reset parsing machinery and start parsing anew,
4492 * or return ERR_PTR.
4494 static struct pipe *parse_stream(char **pstring,
4495 struct in_str *input,
4498 struct parse_context ctx;
4499 o_string dest = NULL_O_STRING;
4502 /* Single-quote triggers a bypass of the main loop until its mate is
4503 * found. When recursing, quote state is passed in via dest->o_expflags.
4505 debug_printf_parse("parse_stream entered, end_trigger='%c'\n",
4506 end_trigger ? end_trigger : 'X');
4509 /* If very first arg is "" or '', dest.data may end up NULL.
4510 * Preventing this: */
4511 o_addchr(&dest, '\0');
4514 /* We used to separate words on $IFS here. This was wrong.
4515 * $IFS is used only for word splitting when $var is expanded,
4516 * here we should use blank chars as separators, not $IFS
4519 if (MAYBE_ASSIGNMENT != 0)
4520 dest.o_assignment = MAYBE_ASSIGNMENT;
4521 initialize_context(&ctx);
4524 const char *is_blank;
4525 const char *is_special;
4529 redir_type redir_style;
4531 ch = i_getch(input);
4532 debug_printf_parse(": ch=%c (%d) escape=%d\n",
4533 ch, ch, !!(dest.o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
4538 syntax_error_unterm_str("here document");
4541 if (end_trigger == ')') {
4542 syntax_error_unterm_ch('(');
4545 if (end_trigger == '}') {
4546 syntax_error_unterm_ch('{');
4550 if (done_word(&dest, &ctx)) {
4554 done_pipe(&ctx, PIPE_SEQ);
4556 /* If we got nothing... */
4557 /* (this makes bare "&" cmd a no-op.
4558 * bash says: "syntax error near unexpected token '&'") */
4559 if (pi->num_cmds == 0
4560 IF_HAS_KEYWORDS(&& pi->res_word == RES_NONE)
4566 debug_printf_parse("as_string1 '%s'\n", ctx.as_string.data);
4568 *pstring = ctx.as_string.data;
4570 o_free_unsafe(&ctx.as_string);
4573 debug_printf_parse("parse_stream return %p\n", pi);
4576 nommu_addchr(&ctx.as_string, ch);
4580 next = i_peek(input);
4582 is_special = "{}<>;&|()#'" /* special outside of "str" */
4583 "\\$\"" IF_HUSH_TICK("`"); /* always special */
4584 /* Are { and } special here? */
4585 if (ctx.command->argv /* word [word]{... - non-special */
4586 || dest.length /* word{... - non-special */
4587 || dest.has_quoted_part /* ""{... - non-special */
4588 || (next != ';' /* }; - special */
4589 && next != ')' /* }) - special */
4590 && next != '(' /* {( - special */
4591 && next != '&' /* }& and }&& ... - special */
4592 && next != '|' /* }|| ... - special */
4593 && !strchr(defifs, next) /* {word - non-special */
4596 /* They are not special, skip "{}" */
4599 is_special = strchr(is_special, ch);
4600 is_blank = strchr(defifs, ch);
4602 if (!is_special && !is_blank) { /* ordinary char */
4604 o_addQchr(&dest, ch);
4605 if ((dest.o_assignment == MAYBE_ASSIGNMENT
4606 || dest.o_assignment == WORD_IS_KEYWORD)
4608 && is_well_formed_var_name(dest.data, '=')
4610 dest.o_assignment = DEFINITELY_ASSIGNMENT;
4611 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4617 if (done_word(&dest, &ctx)) {
4621 /* Is this a case when newline is simply ignored?
4623 * "cmd | <newline> cmd ..."
4624 * "case ... in <newline> word) ..."
4626 if (IS_NULL_CMD(ctx.command)
4627 && dest.length == 0 && !dest.has_quoted_part
4629 /* This newline can be ignored. But...
4630 * Without check #1, interactive shell
4631 * ignores even bare <newline>,
4632 * and shows the continuation prompt:
4633 * ps1_prompt$ <enter>
4634 * ps2> _ <=== wrong, should be ps1
4635 * Without check #2, "cmd & <newline>"
4636 * is similarly mistreated.
4637 * (BTW, this makes "cmd & cmd"
4638 * and "cmd && cmd" non-orthogonal.
4639 * Really, ask yourself, why
4640 * "cmd && <newline>" doesn't start
4641 * cmd but waits for more input?
4644 struct pipe *pi = ctx.list_head;
4645 if (pi->num_cmds != 0 /* check #1 */
4646 && pi->followup != PIPE_BG /* check #2 */
4651 /* Treat newline as a command separator. */
4652 done_pipe(&ctx, PIPE_SEQ);
4653 debug_printf_parse("heredoc_cnt:%d\n", heredoc_cnt);
4655 if (fetch_heredocs(heredoc_cnt, &ctx, input)) {
4660 dest.o_assignment = MAYBE_ASSIGNMENT;
4661 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4663 /* note: if (is_blank) continue;
4664 * will still trigger for us */
4668 /* "cmd}" or "cmd }..." without semicolon or &:
4669 * } is an ordinary char in this case, even inside { cmd; }
4670 * Pathological example: { ""}; } should exec "}" cmd
4673 if (dest.length != 0 /* word} */
4674 || dest.has_quoted_part /* ""} */
4678 if (!IS_NULL_CMD(ctx.command)) { /* cmd } */
4679 /* Generally, there should be semicolon: "cmd; }"
4680 * However, bash allows to omit it if "cmd" is
4681 * a group. Examples:
4684 * { echo 0 >&2 | { echo 1; } }
4685 * { while false; do :; done }
4686 * { case a in b) ;; esac }
4688 if (ctx.command->group)
4692 if (!IS_NULL_PIPE(ctx.pipe)) /* cmd | } */
4693 /* Can't be an end of {cmd}, skip the check */
4694 goto skip_end_trigger;
4695 /* else: } does terminate a group */
4698 if (end_trigger && end_trigger == ch
4699 && (ch != ';' || heredoc_cnt == 0)
4700 #if ENABLE_HUSH_CASE
4702 || ctx.ctx_res_w != RES_MATCH
4703 || (!dest.has_quoted_part && strcmp(dest.data, "esac") == 0)
4708 /* This is technically valid:
4709 * { cat <<HERE; }; echo Ok
4713 * but we don't support this.
4714 * We require heredoc to be in enclosing {}/(),
4717 syntax_error_unterm_str("here document");
4720 if (done_word(&dest, &ctx)) {
4723 done_pipe(&ctx, PIPE_SEQ);
4724 dest.o_assignment = MAYBE_ASSIGNMENT;
4725 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4726 /* Do we sit outside of any if's, loops or case's? */
4728 IF_HAS_KEYWORDS(|| (ctx.ctx_res_w == RES_NONE && ctx.old_flag == 0))
4732 debug_printf_parse("as_string2 '%s'\n", ctx.as_string.data);
4734 *pstring = ctx.as_string.data;
4736 o_free_unsafe(&ctx.as_string);
4739 debug_printf_parse("parse_stream return %p: "
4740 "end_trigger char found\n",
4742 return ctx.list_head;
4749 /* Catch <, > before deciding whether this word is
4750 * an assignment. a=1 2>z b=2: b=2 is still assignment */
4753 redir_fd = redirect_opt_num(&dest);
4754 if (done_word(&dest, &ctx)) {
4757 redir_style = REDIRECT_OVERWRITE;
4759 redir_style = REDIRECT_APPEND;
4760 ch = i_getch(input);
4761 nommu_addchr(&ctx.as_string, ch);
4764 else if (next == '(') {
4765 syntax_error(">(process) not supported");
4769 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4771 continue; /* back to top of while (1) */
4773 redir_fd = redirect_opt_num(&dest);
4774 if (done_word(&dest, &ctx)) {
4777 redir_style = REDIRECT_INPUT;
4779 redir_style = REDIRECT_HEREDOC;
4781 debug_printf_parse("++heredoc_cnt=%d\n", heredoc_cnt);
4782 ch = i_getch(input);
4783 nommu_addchr(&ctx.as_string, ch);
4784 } else if (next == '>') {
4785 redir_style = REDIRECT_IO;
4786 ch = i_getch(input);
4787 nommu_addchr(&ctx.as_string, ch);
4790 else if (next == '(') {
4791 syntax_error("<(process) not supported");
4795 if (parse_redirect(&ctx, redir_fd, redir_style, input))
4797 continue; /* back to top of while (1) */
4799 if (dest.length == 0 && !dest.has_quoted_part) {
4800 /* skip "#comment" */
4803 if (ch == EOF || ch == '\n')
4806 /* note: we do not add it to &ctx.as_string */
4808 nommu_addchr(&ctx.as_string, '\n');
4809 continue; /* back to top of while (1) */
4814 /* It's "\<newline>" */
4816 /* Remove trailing '\' from ctx.as_string */
4817 ctx.as_string.data[--ctx.as_string.length] = '\0';
4819 ch = i_getch(input); /* eat it */
4820 continue; /* back to top of while (1) */
4825 if (dest.o_assignment == MAYBE_ASSIGNMENT
4826 /* check that we are not in word in "a=1 2>word b=1": */
4827 && !ctx.pending_redirect
4829 /* ch is a special char and thus this word
4830 * cannot be an assignment */
4831 dest.o_assignment = NOT_ASSIGNMENT;
4832 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4835 /* Note: nommu_addchr(&ctx.as_string, ch) is already done */
4838 case '#': /* non-comment #: "echo a#b" etc */
4839 o_addQchr(&dest, ch);
4843 syntax_error("\\<eof>");
4846 ch = i_getch(input);
4847 /* note: ch != '\n' (that case does not reach this place) */
4848 o_addchr(&dest, '\\');
4849 /*nommu_addchr(&ctx.as_string, '\\'); - already done */
4850 o_addchr(&dest, ch);
4851 nommu_addchr(&ctx.as_string, ch);
4852 /* Example: echo Hello \2>file
4853 * we need to know that word 2 is quoted */
4854 dest.has_quoted_part = 1;
4857 if (!parse_dollar(&ctx.as_string, &dest, input, /*quote_mask:*/ 0)) {
4858 debug_printf_parse("parse_stream parse error: "
4859 "parse_dollar returned 0 (error)\n");
4864 dest.has_quoted_part = 1;
4865 if (next == '\'' && !ctx.pending_redirect) {
4866 insert_empty_quoted_str_marker:
4867 nommu_addchr(&ctx.as_string, next);
4868 i_getch(input); /* eat second ' */
4869 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4870 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4873 ch = i_getch(input);
4875 syntax_error_unterm_ch('\'');
4878 nommu_addchr(&ctx.as_string, ch);
4881 o_addqchr(&dest, ch);
4886 dest.has_quoted_part = 1;
4887 if (next == '"' && !ctx.pending_redirect)
4888 goto insert_empty_quoted_str_marker;
4889 if (dest.o_assignment == NOT_ASSIGNMENT)
4890 dest.o_expflags |= EXP_FLAG_ESC_GLOB_CHARS;
4891 if (!encode_string(&ctx.as_string, &dest, input, '"', /*process_bkslash:*/ 1))
4893 dest.o_expflags &= ~EXP_FLAG_ESC_GLOB_CHARS;
4895 #if ENABLE_HUSH_TICK
4897 USE_FOR_NOMMU(unsigned pos;)
4899 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4900 o_addchr(&dest, '`');
4901 USE_FOR_NOMMU(pos = dest.length;)
4902 if (!add_till_backquote(&dest, input, /*in_dquote:*/ 0))
4905 o_addstr(&ctx.as_string, dest.data + pos);
4906 o_addchr(&ctx.as_string, '`');
4908 o_addchr(&dest, SPECIAL_VAR_SYMBOL);
4909 //debug_printf_subst("SUBST RES3 '%s'\n", dest.data + pos);
4914 #if ENABLE_HUSH_CASE
4917 if (done_word(&dest, &ctx)) {
4920 done_pipe(&ctx, PIPE_SEQ);
4921 #if ENABLE_HUSH_CASE
4922 /* Eat multiple semicolons, detect
4923 * whether it means something special */
4928 ch = i_getch(input);
4929 nommu_addchr(&ctx.as_string, ch);
4930 if (ctx.ctx_res_w == RES_CASE_BODY) {
4931 ctx.ctx_dsemicolon = 1;
4932 ctx.ctx_res_w = RES_MATCH;
4938 /* We just finished a cmd. New one may start
4939 * with an assignment */
4940 dest.o_assignment = MAYBE_ASSIGNMENT;
4941 debug_printf_parse("dest.o_assignment='%s'\n", assignment_flag[dest.o_assignment]);
4944 if (done_word(&dest, &ctx)) {
4948 ch = i_getch(input);
4949 nommu_addchr(&ctx.as_string, ch);
4950 done_pipe(&ctx, PIPE_AND);
4952 done_pipe(&ctx, PIPE_BG);
4956 if (done_word(&dest, &ctx)) {
4959 #if ENABLE_HUSH_CASE
4960 if (ctx.ctx_res_w == RES_MATCH)
4961 break; /* we are in case's "word | word)" */
4963 if (next == '|') { /* || */
4964 ch = i_getch(input);
4965 nommu_addchr(&ctx.as_string, ch);
4966 done_pipe(&ctx, PIPE_OR);
4968 /* we could pick up a file descriptor choice here
4969 * with redirect_opt_num(), but bash doesn't do it.
4970 * "echo foo 2| cat" yields "foo 2". */
4975 #if ENABLE_HUSH_CASE
4976 /* "case... in [(]word)..." - skip '(' */
4977 if (ctx.ctx_res_w == RES_MATCH
4978 && ctx.command->argv == NULL /* not (word|(... */
4979 && dest.length == 0 /* not word(... */
4980 && dest.has_quoted_part == 0 /* not ""(... */
4986 if (parse_group(&dest, &ctx, input, ch) != 0) {
4991 #if ENABLE_HUSH_CASE
4992 if (ctx.ctx_res_w == RES_MATCH)
4996 /* proper use of this character is caught by end_trigger:
4997 * if we see {, we call parse_group(..., end_trigger='}')
4998 * and it will match } earlier (not here). */
4999 syntax_error_unexpected_ch(ch);
5003 bb_error_msg_and_die("BUG: unexpected %c\n", ch);
5009 struct parse_context *pctx;
5010 IF_HAS_KEYWORDS(struct parse_context *p2;)
5012 /* Clean up allocated tree.
5013 * Sample for finding leaks on syntax error recovery path.
5014 * Run it from interactive shell, watch pmap `pidof hush`.
5015 * while if false; then false; fi; do break; fi
5016 * Samples to catch leaks at execution:
5017 * while if (true | { true;}); then echo ok; fi; do break; done
5018 * while if (true | { true;}); then echo ok; fi; do (if echo ok; break; then :; fi) | cat; break; done
5022 /* Update pipe/command counts,
5023 * otherwise freeing may miss some */
5024 done_pipe(pctx, PIPE_SEQ);
5025 debug_printf_clean("freeing list %p from ctx %p\n",
5026 pctx->list_head, pctx);
5027 debug_print_tree(pctx->list_head, 0);
5028 free_pipe_list(pctx->list_head);
5029 debug_printf_clean("freed list %p\n", pctx->list_head);
5031 o_free_unsafe(&pctx->as_string);
5033 IF_HAS_KEYWORDS(p2 = pctx->stack;)
5037 IF_HAS_KEYWORDS(pctx = p2;)
5038 } while (HAS_KEYWORDS && pctx);
5041 G.last_exitcode = 1;
5052 /*** Execution routines ***/
5054 /* Expansion can recurse, need forward decls: */
5055 #if !ENABLE_HUSH_BASH_COMPAT
5056 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5057 #define expand_string_to_string(str, do_unbackslash) \
5058 expand_string_to_string(str)
5060 static char *expand_string_to_string(const char *str, int do_unbackslash);
5061 #if ENABLE_HUSH_TICK
5062 static int process_command_subs(o_string *dest, const char *s);
5065 /* expand_strvec_to_strvec() takes a list of strings, expands
5066 * all variable references within and returns a pointer to
5067 * a list of expanded strings, possibly with larger number
5068 * of strings. (Think VAR="a b"; echo $VAR).
5069 * This new list is allocated as a single malloc block.
5070 * NULL-terminated list of char* pointers is at the beginning of it,
5071 * followed by strings themselves.
5072 * Caller can deallocate entire list by single free(list). */
5074 /* A horde of its helpers come first: */
5076 static void o_addblock_duplicate_backslash(o_string *o, const char *str, int len)
5078 while (--len >= 0) {
5081 #if ENABLE_HUSH_BRACE_EXPANSION
5082 if (c == '{' || c == '}') {
5083 /* { -> \{, } -> \} */
5085 /* And now we want to add { or } and continue:
5088 * luckily, just falling throught achieves this.
5094 /* \z -> \\\z; \<eol> -> \\<eol> */
5099 o_addchr(o, *str++);
5105 /* Store given string, finalizing the word and starting new one whenever
5106 * we encounter IFS char(s). This is used for expanding variable values.
5107 * End-of-string does NOT finalize word: think about 'echo -$VAR-'.
5108 * Return in *ended_with_ifs:
5109 * 1 - ended with IFS char, else 0 (this includes case of empty str).
5111 static int expand_on_ifs(int *ended_with_ifs, o_string *output, int n, const char *str)
5113 int last_is_ifs = 0;
5118 if (!*str) /* EOL - do not finalize word */
5120 word_len = strcspn(str, G.ifs);
5122 /* We have WORD_LEN leading non-IFS chars */
5123 if (!(output->o_expflags & EXP_FLAG_GLOB)) {
5124 o_addblock(output, str, word_len);
5126 /* Protect backslashes against globbing up :)
5127 * Example: "v='\*'; echo b$v" prints "b\*"
5128 * (and does not try to glob on "*")
5130 o_addblock_duplicate_backslash(output, str, word_len);
5131 /*/ Why can't we do it easier? */
5132 /*o_addblock(output, str, word_len); - WRONG: "v='\*'; echo Z$v" prints "Z*" instead of "Z\*" */
5133 /*o_addqblock(output, str, word_len); - WRONG: "v='*'; echo Z$v" prints "Z*" instead of Z* files */
5137 if (!*str) /* EOL - do not finalize word */
5141 /* We know str here points to at least one IFS char */
5143 str += strspn(str, G.ifs); /* skip IFS chars */
5144 if (!*str) /* EOL - do not finalize word */
5147 /* Start new word... but not always! */
5148 /* Case "v=' a'; echo ''$v": we do need to finalize empty word: */
5149 if (output->has_quoted_part
5150 /* Case "v=' a'; echo $v":
5151 * here nothing precedes the space in $v expansion,
5152 * therefore we should not finish the word
5153 * (IOW: if there *is* word to finalize, only then do it):
5155 || (n > 0 && output->data[output->length - 1])
5157 o_addchr(output, '\0');
5158 debug_print_list("expand_on_ifs", output, n);
5159 n = o_save_ptr(output, n);
5164 *ended_with_ifs = last_is_ifs;
5165 debug_print_list("expand_on_ifs[1]", output, n);
5169 /* Helper to expand $((...)) and heredoc body. These act as if
5170 * they are in double quotes, with the exception that they are not :).
5171 * Just the rules are similar: "expand only $var and `cmd`"
5173 * Returns malloced string.
5174 * As an optimization, we return NULL if expansion is not needed.
5176 #if !ENABLE_HUSH_BASH_COMPAT
5177 /* only ${var/pattern/repl} (its pattern part) needs additional mode */
5178 #define encode_then_expand_string(str, process_bkslash, do_unbackslash) \
5179 encode_then_expand_string(str)
5181 static char *encode_then_expand_string(const char *str, int process_bkslash, int do_unbackslash)
5184 struct in_str input;
5185 o_string dest = NULL_O_STRING;
5187 if (!strchr(str, '$')
5188 && !strchr(str, '\\')
5189 #if ENABLE_HUSH_TICK
5190 && !strchr(str, '`')
5196 /* We need to expand. Example:
5197 * echo $(($a + `echo 1`)) $((1 + $((2)) ))
5199 setup_string_in_str(&input, str);
5200 encode_string(NULL, &dest, &input, EOF, process_bkslash);
5201 //TODO: error check (encode_string returns 0 on error)?
5202 //bb_error_msg("'%s' -> '%s'", str, dest.data);
5203 exp_str = expand_string_to_string(dest.data, /*unbackslash:*/ do_unbackslash);
5204 //bb_error_msg("'%s' -> '%s'", dest.data, exp_str);
5205 o_free_unsafe(&dest);
5209 #if ENABLE_FEATURE_SH_MATH
5210 static arith_t expand_and_evaluate_arith(const char *arg, const char **errmsg_p)
5212 arith_state_t math_state;
5216 math_state.lookupvar = get_local_var_value;
5217 math_state.setvar = set_local_var_from_halves;
5218 //math_state.endofname = endofname;
5219 exp_str = encode_then_expand_string(arg, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5220 res = arith(&math_state, exp_str ? exp_str : arg);
5223 *errmsg_p = math_state.errmsg;
5224 if (math_state.errmsg)
5225 die_if_script(math_state.errmsg);
5230 #if ENABLE_HUSH_BASH_COMPAT
5231 /* ${var/[/]pattern[/repl]} helpers */
5232 static char *strstr_pattern(char *val, const char *pattern, int *size)
5235 char *end = scan_and_match(val, pattern, SCAN_MOVE_FROM_RIGHT + SCAN_MATCH_LEFT_HALF);
5236 debug_printf_varexp("val:'%s' pattern:'%s' end:'%s'\n", val, pattern, end);
5243 /* Optimization: if "*pat" did not match the start of "string",
5244 * we know that "tring", "ring" etc will not match too:
5246 if (pattern[0] == '*')
5251 static char *replace_pattern(char *val, const char *pattern, const char *repl, char exp_op)
5253 char *result = NULL;
5254 unsigned res_len = 0;
5255 unsigned repl_len = strlen(repl);
5259 char *s = strstr_pattern(val, pattern, &size);
5263 result = xrealloc(result, res_len + (s - val) + repl_len + 1);
5264 memcpy(result + res_len, val, s - val);
5266 strcpy(result + res_len, repl);
5267 res_len += repl_len;
5268 debug_printf_varexp("val:'%s' s:'%s' result:'%s'\n", val, s, result);
5274 if (val[0] && result) {
5275 result = xrealloc(result, res_len + strlen(val) + 1);
5276 strcpy(result + res_len, val);
5277 debug_printf_varexp("val:'%s' result:'%s'\n", val, result);
5279 debug_printf_varexp("result:'%s'\n", result);
5285 * Handles <SPECIAL_VAR_SYMBOL>varname...<SPECIAL_VAR_SYMBOL> construct.
5287 static NOINLINE const char *expand_one_var(char **to_be_freed_pp, char *arg, char **pp)
5289 const char *val = NULL;
5290 char *to_be_freed = NULL;
5295 char exp_save = exp_save; /* for compiler */
5296 char *exp_saveptr; /* points to expansion operator */
5297 char *exp_word = exp_word; /* for compiler */
5300 *p = '\0'; /* replace trailing SPECIAL_VAR_SYMBOL */
5302 exp_saveptr = arg[1] ? strchr(VAR_ENCODED_SUBST_OPS, arg[1]) : NULL;
5304 first_char = arg[0] = arg0 & 0x7f;
5307 if (first_char == '#' /* ${#... */
5308 && arg[1] && !exp_saveptr /* not ${#} and not ${#<op_char>...} */
5310 /* It must be length operator: ${#var} */
5314 /* Maybe handle parameter expansion */
5315 if (exp_saveptr /* if 2nd char is one of expansion operators */
5316 && strchr(NUMERIC_SPECVARS_STR, first_char) /* 1st char is special variable */
5318 /* ${?:0}, ${#[:]%0} etc */
5319 exp_saveptr = var + 1;
5321 /* ${?}, ${var}, ${var:0}, ${var[:]%0} etc */
5322 exp_saveptr = var+1 + strcspn(var+1, VAR_ENCODED_SUBST_OPS);
5324 exp_op = exp_save = *exp_saveptr;
5326 exp_word = exp_saveptr + 1;
5327 if (exp_op == ':') {
5328 exp_op = *exp_word++;
5329 //TODO: try ${var:} and ${var:bogus} in non-bash config
5330 if (ENABLE_HUSH_BASH_COMPAT
5331 && (!exp_op || !strchr(MINUS_PLUS_EQUAL_QUESTION, exp_op))
5333 /* oops... it's ${var:N[:M]}, not ${var:?xxx} or some such */
5338 *exp_saveptr = '\0';
5339 } /* else: it's not an expansion op, but bare ${var} */
5342 /* Look up the variable in question */
5343 if (isdigit(var[0])) {
5344 /* parse_dollar should have vetted var for us */
5345 int n = xatoi_positive(var);
5346 if (n < G.global_argc)
5347 val = G.global_argv[n];
5348 /* else val remains NULL: $N with too big N */
5352 val = utoa(G.root_pid);
5354 case '!': /* bg pid */
5355 val = G.last_bg_pid ? utoa(G.last_bg_pid) : "";
5357 case '?': /* exitcode */
5358 val = utoa(G.last_exitcode);
5360 case '#': /* argc */
5361 val = utoa(G.global_argc ? G.global_argc-1 : 0);
5364 val = get_local_var_value(var);
5368 /* Handle any expansions */
5369 if (exp_op == 'L') {
5370 reinit_unicode_for_hush();
5371 debug_printf_expand("expand: length(%s)=", val);
5372 val = utoa(val ? unicode_strlen(val) : 0);
5373 debug_printf_expand("%s\n", val);
5374 } else if (exp_op) {
5375 if (exp_op == '%' || exp_op == '#') {
5376 /* Standard-mandated substring removal ops:
5377 * ${parameter%word} - remove smallest suffix pattern
5378 * ${parameter%%word} - remove largest suffix pattern
5379 * ${parameter#word} - remove smallest prefix pattern
5380 * ${parameter##word} - remove largest prefix pattern
5382 * Word is expanded to produce a glob pattern.
5383 * Then var's value is matched to it and matching part removed.
5385 if (val && val[0]) {
5389 unsigned scan_flags = pick_scan(exp_op, *exp_word);
5390 if (exp_op == *exp_word) /* ## or %% */
5392 exp_exp_word = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5394 exp_word = exp_exp_word;
5395 /* HACK ALERT. We depend here on the fact that
5396 * G.global_argv and results of utoa and get_local_var_value
5397 * are actually in writable memory:
5398 * scan_and_match momentarily stores NULs there. */
5400 loc = scan_and_match(t, exp_word, scan_flags);
5401 //bb_error_msg("op:%c str:'%s' pat:'%s' res:'%s'",
5402 // exp_op, t, exp_word, loc);
5404 if (loc) { /* match was found */
5405 if (scan_flags & SCAN_MATCH_LEFT_HALF) /* #[#] */
5406 val = loc; /* take right part */
5408 val = to_be_freed = xstrndup(val, loc - val); /* left */
5412 #if ENABLE_HUSH_BASH_COMPAT
5413 else if (exp_op == '/' || exp_op == '\\') {
5414 /* It's ${var/[/]pattern[/repl]} thing.
5415 * Note that in encoded form it has TWO parts:
5416 * var/pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5417 * and if // is used, it is encoded as \:
5418 * var\pattern<SPECIAL_VAR_SYMBOL>repl<SPECIAL_VAR_SYMBOL>
5420 /* Empty variable always gives nothing: */
5421 // "v=''; echo ${v/*/w}" prints "", not "w"
5422 if (val && val[0]) {
5423 /* pattern uses non-standard expansion.
5424 * repl should be unbackslashed and globbed
5425 * by the usual expansion rules:
5427 * v='a bz'; echo "${v/a*z/a*z}" prints "a*z"
5428 * v='a bz'; echo "${v/a*z/\z}" prints "\z"
5429 * v='a bz'; echo ${v/a*z/a*z} prints "az"
5430 * v='a bz'; echo ${v/a*z/\z} prints "z"
5431 * (note that a*z _pattern_ is never globbed!)
5433 char *pattern, *repl, *t;
5434 pattern = encode_then_expand_string(exp_word, /*process_bkslash:*/ 0, /*unbackslash:*/ 0);
5436 pattern = xstrdup(exp_word);
5437 debug_printf_varexp("pattern:'%s'->'%s'\n", exp_word, pattern);
5438 *p++ = SPECIAL_VAR_SYMBOL;
5440 p = strchr(p, SPECIAL_VAR_SYMBOL);
5442 repl = encode_then_expand_string(exp_word, /*process_bkslash:*/ arg0 & 0x80, /*unbackslash:*/ 1);
5443 debug_printf_varexp("repl:'%s'->'%s'\n", exp_word, repl);
5444 /* HACK ALERT. We depend here on the fact that
5445 * G.global_argv and results of utoa and get_local_var_value
5446 * are actually in writable memory:
5447 * replace_pattern momentarily stores NULs there. */
5449 to_be_freed = replace_pattern(t,
5451 (repl ? repl : exp_word),
5453 if (to_be_freed) /* at least one replace happened */
5460 else if (exp_op == ':') {
5461 #if ENABLE_HUSH_BASH_COMPAT && ENABLE_FEATURE_SH_MATH
5462 /* It's ${var:N[:M]} bashism.
5463 * Note that in encoded form it has TWO parts:
5464 * var:N<SPECIAL_VAR_SYMBOL>M<SPECIAL_VAR_SYMBOL>
5469 beg = expand_and_evaluate_arith(exp_word, &errmsg);
5472 debug_printf_varexp("beg:'%s'=%lld\n", exp_word, (long long)beg);
5473 *p++ = SPECIAL_VAR_SYMBOL;
5475 p = strchr(p, SPECIAL_VAR_SYMBOL);
5477 len = expand_and_evaluate_arith(exp_word, &errmsg);
5480 debug_printf_varexp("len:'%s'=%lld\n", exp_word, (long long)len);
5481 if (len >= 0) { /* bash compat: len < 0 is illegal */
5482 if (beg < 0) /* bash compat */
5484 debug_printf_varexp("from val:'%s'\n", val);
5485 if (len == 0 || !val || beg >= strlen(val)) {
5489 /* Paranoia. What if user entered 9999999999999
5490 * which fits in arith_t but not int? */
5493 val = to_be_freed = xstrndup(val + beg, len);
5495 debug_printf_varexp("val:'%s'\n", val);
5499 die_if_script("malformed ${%s:...}", var);
5502 } else { /* one of "-=+?" */
5503 /* Standard-mandated substitution ops:
5504 * ${var?word} - indicate error if unset
5505 * If var is unset, word (or a message indicating it is unset
5506 * if word is null) is written to standard error
5507 * and the shell exits with a non-zero exit status.
5508 * Otherwise, the value of var is substituted.
5509 * ${var-word} - use default value
5510 * If var is unset, word is substituted.
5511 * ${var=word} - assign and use default value
5512 * If var is unset, word is assigned to var.
5513 * In all cases, final value of var is substituted.
5514 * ${var+word} - use alternative value
5515 * If var is unset, null is substituted.
5516 * Otherwise, word is substituted.
5518 * Word is subjected to tilde expansion, parameter expansion,
5519 * command substitution, and arithmetic expansion.
5520 * If word is not needed, it is not expanded.
5522 * Colon forms (${var:-word}, ${var:=word} etc) do the same,
5523 * but also treat null var as if it is unset.
5525 int use_word = (!val || ((exp_save == ':') && !val[0]));
5527 use_word = !use_word;
5528 debug_printf_expand("expand: op:%c (null:%s) test:%i\n", exp_op,
5529 (exp_save == ':') ? "true" : "false", use_word);
5531 to_be_freed = encode_then_expand_string(exp_word, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
5533 exp_word = to_be_freed;
5534 if (exp_op == '?') {
5535 /* mimic bash message */
5536 die_if_script("%s: %s",
5538 exp_word[0] ? exp_word : "parameter null or not set"
5540 //TODO: how interactive bash aborts expansion mid-command?
5545 if (exp_op == '=') {
5546 /* ${var=[word]} or ${var:=[word]} */
5547 if (isdigit(var[0]) || var[0] == '#') {
5548 /* mimic bash message */
5549 die_if_script("$%s: cannot assign in this way", var);
5552 char *new_var = xasprintf("%s=%s", var, val);
5553 set_local_var(new_var, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
5557 } /* one of "-=+?" */
5559 *exp_saveptr = exp_save;
5565 *to_be_freed_pp = to_be_freed;
5569 /* Expand all variable references in given string, adding words to list[]
5570 * at n, n+1,... positions. Return updated n (so that list[n] is next one
5571 * to be filled). This routine is extremely tricky: has to deal with
5572 * variables/parameters with whitespace, $* and $@, and constructs like
5573 * 'echo -$*-'. If you play here, you must run testsuite afterwards! */
5574 static NOINLINE int expand_vars_to_list(o_string *output, int n, char *arg)
5576 /* output->o_expflags & EXP_FLAG_SINGLEWORD (0x80) if we are in
5577 * expansion of right-hand side of assignment == 1-element expand.
5579 char cant_be_null = 0; /* only bit 0x80 matters */
5580 int ended_in_ifs = 0; /* did last unquoted expansion end with IFS chars? */
5583 debug_printf_expand("expand_vars_to_list: arg:'%s' singleword:%x\n", arg,
5584 !!(output->o_expflags & EXP_FLAG_SINGLEWORD));
5585 debug_print_list("expand_vars_to_list", output, n);
5586 n = o_save_ptr(output, n);
5587 debug_print_list("expand_vars_to_list[0]", output, n);
5589 while ((p = strchr(arg, SPECIAL_VAR_SYMBOL)) != NULL) {
5591 char *to_be_freed = NULL;
5592 const char *val = NULL;
5593 #if ENABLE_HUSH_TICK
5594 o_string subst_result = NULL_O_STRING;
5596 #if ENABLE_FEATURE_SH_MATH
5597 char arith_buf[sizeof(arith_t)*3 + 2];
5601 o_addchr(output, '\0');
5602 n = o_save_ptr(output, n);
5606 o_addblock(output, arg, p - arg);
5607 debug_print_list("expand_vars_to_list[1]", output, n);
5609 p = strchr(p, SPECIAL_VAR_SYMBOL);
5611 /* Fetch special var name (if it is indeed one of them)
5612 * and quote bit, force the bit on if singleword expansion -
5613 * important for not getting v=$@ expand to many words. */
5614 first_ch = arg[0] | (output->o_expflags & EXP_FLAG_SINGLEWORD);
5616 /* Is this variable quoted and thus expansion can't be null?
5617 * "$@" is special. Even if quoted, it can still
5618 * expand to nothing (not even an empty string),
5619 * thus it is excluded. */
5620 if ((first_ch & 0x7f) != '@')
5621 cant_be_null |= first_ch;
5623 switch (first_ch & 0x7f) {
5624 /* Highest bit in first_ch indicates that var is double-quoted */
5628 if (!G.global_argv[1])
5631 cant_be_null |= first_ch; /* do it for "$@" _now_, when we know it's not empty */
5632 if (!(first_ch & 0x80)) { /* unquoted $* or $@ */
5633 while (G.global_argv[i]) {
5634 n = expand_on_ifs(NULL, output, n, G.global_argv[i]);
5635 debug_printf_expand("expand_vars_to_list: argv %d (last %d)\n", i, G.global_argc - 1);
5636 if (G.global_argv[i++][0] && G.global_argv[i]) {
5637 /* this argv[] is not empty and not last:
5638 * put terminating NUL, start new word */
5639 o_addchr(output, '\0');
5640 debug_print_list("expand_vars_to_list[2]", output, n);
5641 n = o_save_ptr(output, n);
5642 debug_print_list("expand_vars_to_list[3]", output, n);
5646 /* If EXP_FLAG_SINGLEWORD, we handle assignment 'a=....$@.....'
5647 * and in this case should treat it like '$*' - see 'else...' below */
5648 if (first_ch == ('@'|0x80) /* quoted $@ */
5649 && !(output->o_expflags & EXP_FLAG_SINGLEWORD) /* not v="$@" case */
5652 o_addQstr(output, G.global_argv[i]);
5653 if (++i >= G.global_argc)
5655 o_addchr(output, '\0');
5656 debug_print_list("expand_vars_to_list[4]", output, n);
5657 n = o_save_ptr(output, n);
5659 } else { /* quoted $* (or v="$@" case): add as one word */
5661 o_addQstr(output, G.global_argv[i]);
5662 if (!G.global_argv[++i])
5665 o_addchr(output, G.ifs[0]);
5667 output->has_quoted_part = 1;
5671 case SPECIAL_VAR_SYMBOL: /* <SPECIAL_VAR_SYMBOL><SPECIAL_VAR_SYMBOL> */
5672 /* "Empty variable", used to make "" etc to not disappear */
5673 output->has_quoted_part = 1;
5675 cant_be_null = 0x80;
5677 #if ENABLE_HUSH_TICK
5678 case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */
5679 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5681 /* Can't just stuff it into output o_string,
5682 * expanded result may need to be globbed
5683 * and $IFS-splitted */
5684 debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch);
5685 G.last_exitcode = process_command_subs(&subst_result, arg);
5686 debug_printf_subst("SUBST RES:%d '%s'\n", G.last_exitcode, subst_result.data);
5687 val = subst_result.data;
5690 #if ENABLE_FEATURE_SH_MATH
5691 case '+': { /* <SPECIAL_VAR_SYMBOL>+cmd<SPECIAL_VAR_SYMBOL> */
5694 arg++; /* skip '+' */
5695 *p = '\0'; /* replace trailing <SPECIAL_VAR_SYMBOL> */
5696 debug_printf_subst("ARITH '%s' first_ch %x\n", arg, first_ch);
5697 res = expand_and_evaluate_arith(arg, NULL);
5698 debug_printf_subst("ARITH RES '"ARITH_FMT"'\n", res);
5699 sprintf(arith_buf, ARITH_FMT, res);
5705 val = expand_one_var(&to_be_freed, arg, &p);
5706 IF_HUSH_TICK(store_val:)
5707 if (!(first_ch & 0x80)) { /* unquoted $VAR */
5708 debug_printf_expand("unquoted '%s', output->o_escape:%d\n", val,
5709 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5710 if (val && val[0]) {
5711 n = expand_on_ifs(&ended_in_ifs, output, n, val);
5714 } else { /* quoted $VAR, val will be appended below */
5715 output->has_quoted_part = 1;
5716 debug_printf_expand("quoted '%s', output->o_escape:%d\n", val,
5717 !!(output->o_expflags & EXP_FLAG_ESC_GLOB_CHARS));
5720 } /* switch (char after <SPECIAL_VAR_SYMBOL>) */
5722 if (val && val[0]) {
5723 o_addQstr(output, val);
5727 /* Restore NULL'ed SPECIAL_VAR_SYMBOL.
5728 * Do the check to avoid writing to a const string. */
5729 if (*p != SPECIAL_VAR_SYMBOL)
5730 *p = SPECIAL_VAR_SYMBOL;
5732 #if ENABLE_HUSH_TICK
5733 o_free(&subst_result);
5736 } /* end of "while (SPECIAL_VAR_SYMBOL is found) ..." */
5740 o_addchr(output, '\0');
5741 n = o_save_ptr(output, n);
5743 debug_print_list("expand_vars_to_list[a]", output, n);
5744 /* this part is literal, and it was already pre-quoted
5745 * if needed (much earlier), do not use o_addQstr here! */
5746 o_addstr_with_NUL(output, arg);
5747 debug_print_list("expand_vars_to_list[b]", output, n);
5748 } else if (output->length == o_get_last_ptr(output, n) /* expansion is empty */
5749 && !(cant_be_null & 0x80) /* and all vars were not quoted. */
5752 /* allow to reuse list[n] later without re-growth */
5753 output->has_empty_slot = 1;
5755 o_addchr(output, '\0');
5761 static char **expand_variables(char **argv, unsigned expflags)
5765 o_string output = NULL_O_STRING;
5767 output.o_expflags = expflags;
5771 n = expand_vars_to_list(&output, n, *argv);
5774 debug_print_list("expand_variables", &output, n);
5776 /* output.data (malloced in one block) gets returned in "list" */
5777 list = o_finalize_list(&output, n);
5778 debug_print_strings("expand_variables[1]", list);
5782 static char **expand_strvec_to_strvec(char **argv)
5784 return expand_variables(argv, EXP_FLAG_GLOB | EXP_FLAG_ESC_GLOB_CHARS);
5787 #if ENABLE_HUSH_BASH_COMPAT
5788 static char **expand_strvec_to_strvec_singleword_noglob(char **argv)
5790 return expand_variables(argv, EXP_FLAG_SINGLEWORD);
5794 /* Used for expansion of right hand of assignments,
5795 * $((...)), heredocs, variable espansion parts.
5797 * NB: should NOT do globbing!
5798 * "export v=/bin/c*; env | grep ^v=" outputs "v=/bin/c*"
5800 static char *expand_string_to_string(const char *str, int do_unbackslash)
5802 #if !ENABLE_HUSH_BASH_COMPAT
5803 const int do_unbackslash = 1;
5805 char *argv[2], **list;
5807 debug_printf_expand("string_to_string<='%s'\n", str);
5808 /* This is generally an optimization, but it also
5809 * handles "", which otherwise trips over !list[0] check below.
5810 * (is this ever happens that we actually get str="" here?)
5812 if (!strchr(str, SPECIAL_VAR_SYMBOL) && !strchr(str, '\\')) {
5813 //TODO: Can use on strings with \ too, just unbackslash() them?
5814 debug_printf_expand("string_to_string(fast)=>'%s'\n", str);
5815 return xstrdup(str);
5818 argv[0] = (char*)str;
5820 list = expand_variables(argv, do_unbackslash
5821 ? EXP_FLAG_ESC_GLOB_CHARS | EXP_FLAG_SINGLEWORD
5822 : EXP_FLAG_SINGLEWORD
5825 if (!list[0] || list[1])
5826 bb_error_msg_and_die("BUG in varexp2");
5827 /* actually, just move string 2*sizeof(char*) bytes back */
5828 overlapping_strcpy((char*)list, list[0]);
5830 unbackslash((char*)list);
5831 debug_printf_expand("string_to_string=>'%s'\n", (char*)list);
5835 /* Used for "eval" builtin */
5836 static char* expand_strvec_to_string(char **argv)
5840 list = expand_variables(argv, EXP_FLAG_SINGLEWORD);
5841 /* Convert all NULs to spaces */
5846 if (list[n-1] + strlen(list[n-1]) + 1 != list[n])
5847 bb_error_msg_and_die("BUG in varexp3");
5848 /* bash uses ' ' regardless of $IFS contents */
5853 overlapping_strcpy((char*)list, list[0] ? list[0] : "");
5854 debug_printf_expand("strvec_to_string='%s'\n", (char*)list);
5858 static char **expand_assignments(char **argv, int count)
5863 G.expanded_assignments = p = NULL;
5864 /* Expand assignments into one string each */
5865 for (i = 0; i < count; i++) {
5866 G.expanded_assignments = p = add_string_to_strings(p, expand_string_to_string(argv[i], /*unbackslash:*/ 1));
5868 G.expanded_assignments = NULL;
5873 static void switch_off_special_sigs(unsigned mask)
5876 while ((mask >>= 1) != 0) {
5881 if (G.traps[sig] && !G.traps[sig][0])
5882 /* trap is '', has to remain SIG_IGN */
5885 G.traps[sig] = NULL;
5887 /* We are here only if no trap or trap was not '' */
5888 install_sighandler(sig, SIG_DFL);
5894 void re_execute_shell(char ***to_free, const char *s,
5895 char *g_argv0, char **g_argv,
5896 char **builtin_argv) NORETURN;
5898 static void reset_traps_to_defaults(void)
5900 /* This function is always called in a child shell
5901 * after fork (not vfork, NOMMU doesn't use this function).
5906 /* Child shells are not interactive.
5907 * SIGTTIN/SIGTTOU/SIGTSTP should not have special handling.
5908 * Testcase: (while :; do :; done) + ^Z should background.
5909 * Same goes for SIGTERM, SIGHUP, SIGINT.
5911 mask = (G.special_sig_mask & SPECIAL_INTERACTIVE_SIGS) | G_fatal_sig_mask;
5912 if (!G.traps && !mask)
5913 return; /* already no traps and no special sigs */
5915 /* Switch off special sigs */
5916 switch_off_special_sigs(mask);
5918 G_fatal_sig_mask = 0;
5920 G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
5921 /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
5922 * remain set in G.special_sig_mask */
5927 /* Reset all sigs to default except ones with empty traps */
5928 for (sig = 0; sig < NSIG; sig++) {
5930 continue; /* no trap: nothing to do */
5931 if (!G.traps[sig][0])
5932 continue; /* empty trap: has to remain SIG_IGN */
5933 /* sig has non-empty trap, reset it: */
5935 G.traps[sig] = NULL;
5936 /* There is no signal for trap 0 (EXIT) */
5939 install_sighandler(sig, pick_sighandler(sig));
5945 static void re_execute_shell(char ***to_free, const char *s,
5946 char *g_argv0, char **g_argv,
5947 char **builtin_argv) NORETURN;
5948 static void re_execute_shell(char ***to_free, const char *s,
5949 char *g_argv0, char **g_argv,
5950 char **builtin_argv)
5952 # define NOMMU_HACK_FMT ("-$%x:%x:%x:%x:%x:%llx" IF_HUSH_LOOPS(":%x"))
5953 /* delims + 2 * (number of bytes in printed hex numbers) */
5954 char param_buf[sizeof(NOMMU_HACK_FMT) + 2 * (sizeof(int)*6 + sizeof(long long)*1)];
5955 char *heredoc_argv[4];
5956 struct variable *cur;
5957 # if ENABLE_HUSH_FUNCTIONS
5958 struct function *funcp;
5962 unsigned long long empty_trap_mask;
5964 if (!g_argv0) { /* heredoc */
5965 argv = heredoc_argv;
5966 argv[0] = (char *) G.argv0_for_re_execing;
5967 argv[1] = (char *) "-<";
5968 argv[2] = (char *) s;
5970 pp = &argv[3]; /* used as pointer to empty environment */
5976 if (pp) while (*pp++)
5979 empty_trap_mask = 0;
5982 for (sig = 1; sig < NSIG; sig++) {
5983 if (G.traps[sig] && !G.traps[sig][0])
5984 empty_trap_mask |= 1LL << sig;
5988 sprintf(param_buf, NOMMU_HACK_FMT
5989 , (unsigned) G.root_pid
5990 , (unsigned) G.root_ppid
5991 , (unsigned) G.last_bg_pid
5992 , (unsigned) G.last_exitcode
5995 IF_HUSH_LOOPS(, G.depth_of_loop)
5997 # undef NOMMU_HACK_FMT
5998 /* 1:hush 2:-$<pid>:<pid>:<exitcode>:<etc...> <vars...> <funcs...>
5999 * 3:-c 4:<cmd> 5:<arg0> <argN...> 6:NULL
6002 for (cur = G.top_var; cur; cur = cur->next) {
6003 if (!cur->flg_export || cur->flg_read_only)
6006 # if ENABLE_HUSH_FUNCTIONS
6007 for (funcp = G.top_func; funcp; funcp = funcp->next)
6013 *to_free = argv = pp = xzalloc(sizeof(argv[0]) * cnt);
6014 *pp++ = (char *) G.argv0_for_re_execing;
6016 for (cur = G.top_var; cur; cur = cur->next) {
6017 if (strcmp(cur->varstr, hush_version_str) == 0)
6019 if (cur->flg_read_only) {
6020 *pp++ = (char *) "-R";
6021 *pp++ = cur->varstr;
6022 } else if (!cur->flg_export) {
6023 *pp++ = (char *) "-V";
6024 *pp++ = cur->varstr;
6027 # if ENABLE_HUSH_FUNCTIONS
6028 for (funcp = G.top_func; funcp; funcp = funcp->next) {
6029 *pp++ = (char *) "-F";
6030 *pp++ = funcp->name;
6031 *pp++ = funcp->body_as_string;
6034 /* We can pass activated traps here. Say, -Tnn:trap_string
6036 * However, POSIX says that subshells reset signals with traps
6038 * I tested bash-3.2 and it not only does that with true subshells
6039 * of the form ( list ), but with any forked children shells.
6040 * I set trap "echo W" WINCH; and then tried:
6042 * { echo 1; sleep 20; echo 2; } &
6043 * while true; do echo 1; sleep 20; echo 2; break; done &
6044 * true | { echo 1; sleep 20; echo 2; } | cat
6046 * In all these cases sending SIGWINCH to the child shell
6047 * did not run the trap. If I add trap "echo V" WINCH;
6048 * _inside_ group (just before echo 1), it works.
6050 * I conclude it means we don't need to pass active traps here.
6052 *pp++ = (char *) "-c";
6055 while (*++builtin_argv)
6056 *pp++ = *builtin_argv;
6057 *pp++ = (char *) "";
6062 /* *pp = NULL; - is already there */
6066 debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
6067 /* Don't propagate SIG_IGN to the child */
6068 if (SPECIAL_JOBSTOP_SIGS != 0)
6069 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6070 execve(bb_busybox_exec_path, argv, pp);
6071 /* Fallback. Useful for init=/bin/hush usage etc */
6072 if (argv[0][0] == '/')
6073 execve(argv[0], argv, pp);
6074 xfunc_error_retval = 127;
6075 bb_error_msg_and_die("can't re-execute the shell");
6077 #endif /* !BB_MMU */
6080 static int run_and_free_list(struct pipe *pi);
6082 /* Executing from string: eval, sh -c '...'
6083 * or from file: /etc/profile, . file, sh <script>, sh (intereactive)
6084 * end_trigger controls how often we stop parsing
6085 * NUL: parse all, execute, return
6086 * ';': parse till ';' or newline, execute, repeat till EOF
6088 static void parse_and_run_stream(struct in_str *inp, int end_trigger)
6090 /* Why we need empty flag?
6091 * An obscure corner case "false; ``; echo $?":
6092 * empty command in `` should still set $? to 0.
6093 * But we can't just set $? to 0 at the start,
6094 * this breaks "false; echo `echo $?`" case.
6098 struct pipe *pipe_list;
6100 #if ENABLE_HUSH_INTERACTIVE
6101 if (end_trigger == ';')
6102 inp->promptmode = 0; /* PS1 */
6104 pipe_list = parse_stream(NULL, inp, end_trigger);
6105 if (!pipe_list || pipe_list == ERR_PTR) { /* EOF/error */
6106 /* If we are in "big" script
6107 * (not in `cmd` or something similar)...
6109 if (pipe_list == ERR_PTR && end_trigger == ';') {
6110 /* Discard cached input (rest of line) */
6111 int ch = inp->last_char;
6112 while (ch != EOF && ch != '\n') {
6113 //bb_error_msg("Discarded:'%c'", ch);
6118 /* This stream isn't empty */
6122 if (!pipe_list && empty)
6123 G.last_exitcode = 0;
6126 debug_print_tree(pipe_list, 0);
6127 debug_printf_exec("parse_and_run_stream: run_and_free_list\n");
6128 run_and_free_list(pipe_list);
6130 if (G_flag_return_in_progress == 1)
6135 static void parse_and_run_string(const char *s)
6137 struct in_str input;
6138 setup_string_in_str(&input, s);
6139 parse_and_run_stream(&input, '\0');
6142 static void parse_and_run_file(FILE *f)
6144 struct in_str input;
6145 setup_file_in_str(&input, f);
6146 parse_and_run_stream(&input, ';');
6149 #if ENABLE_HUSH_TICK
6150 static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
6155 char **to_free = NULL;
6159 pid = BB_MMU ? xfork() : xvfork();
6160 if (pid == 0) { /* child */
6161 disable_restore_tty_pgrp_on_exit();
6162 /* Process substitution is not considered to be usual
6163 * 'command execution'.
6164 * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
6171 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
6172 close(channel[0]); /* NB: close _first_, then move fd! */
6173 xmove_fd(channel[1], 1);
6174 /* Prevent it from trying to handle ctrl-z etc */
6175 IF_HUSH_JOB(G.run_list_level = 1;)
6176 /* Awful hack for `trap` or $(trap).
6178 * http://www.opengroup.org/onlinepubs/009695399/utilities/trap.html
6179 * contains an example where "trap" is executed in a subshell:
6181 * save_traps=$(trap)
6183 * eval "$save_traps"
6185 * Standard does not say that "trap" in subshell shall print
6186 * parent shell's traps. It only says that its output
6187 * must have suitable form, but then, in the above example
6188 * (which is not supposed to be normative), it implies that.
6190 * bash (and probably other shell) does implement it
6191 * (traps are reset to defaults, but "trap" still shows them),
6192 * but as a result, "trap" logic is hopelessly messed up:
6195 * trap -- 'echo Ho' SIGWINCH <--- we have a handler
6196 * # (trap) <--- trap is in subshell - no output (correct, traps are reset)
6197 * # true | trap <--- trap is in subshell - no output (ditto)
6198 * # echo `true | trap` <--- in subshell - output (but traps are reset!)
6199 * trap -- 'echo Ho' SIGWINCH
6200 * # echo `(trap)` <--- in subshell in subshell - output
6201 * trap -- 'echo Ho' SIGWINCH
6202 * # echo `true | (trap)` <--- in subshell in subshell in subshell - output!
6203 * trap -- 'echo Ho' SIGWINCH
6205 * The rules when to forget and when to not forget traps
6206 * get really complex and nonsensical.
6208 * Our solution: ONLY bare $(trap) or `trap` is special.
6210 s = skip_whitespace(s);
6211 if (is_prefixed_with(s, "trap")
6212 && skip_whitespace(s + 4)[0] == '\0'
6214 static const char *const argv[] = { NULL, NULL };
6215 builtin_trap((char**)argv);
6216 fflush_all(); /* important */
6220 reset_traps_to_defaults();
6221 parse_and_run_string(s);
6222 _exit(G.last_exitcode);
6224 /* We re-execute after vfork on NOMMU. This makes this script safe:
6225 * yes "0123456789012345678901234567890" | dd bs=32 count=64k >BIG
6226 * huge=`cat BIG` # was blocking here forever
6229 re_execute_shell(&to_free,
6239 # if ENABLE_HUSH_FAST
6241 //bb_error_msg("[%d] fork in generate_stream_from_string:"
6242 // " G.count_SIGCHLD:%d G.handled_SIGCHLD:%d",
6243 // getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6245 enable_restore_tty_pgrp_on_exit();
6250 return remember_FILE(xfdopen_for_read(channel[0]));
6253 /* Return code is exit status of the process that is run. */
6254 static int process_command_subs(o_string *dest, const char *s)
6257 struct in_str pipe_str;
6259 int status, ch, eol_cnt;
6261 fp = generate_stream_from_string(s, &pid);
6263 /* Now send results of command back into original context */
6264 setup_file_in_str(&pipe_str, fp);
6266 while ((ch = i_getch(&pipe_str)) != EOF) {
6272 o_addchr(dest, '\n');
6275 o_addQchr(dest, ch);
6278 debug_printf("done reading from `cmd` pipe, closing it\n");
6279 fclose_and_forget(fp);
6280 /* We need to extract exitcode. Test case
6281 * "true; echo `sleep 1; false` $?"
6283 safe_waitpid(pid, &status, 0);
6284 debug_printf("child exited. returning its exitcode:%d\n", WEXITSTATUS(status));
6285 return WEXITSTATUS(status);
6287 #endif /* ENABLE_HUSH_TICK */
6290 static void setup_heredoc(struct redir_struct *redir)
6292 struct fd_pair pair;
6295 /* the _body_ of heredoc (misleading field name) */
6296 const char *heredoc = redir->rd_filename;
6303 if (!(redir->rd_dup & HEREDOC_QUOTED)) {
6304 expanded = encode_then_expand_string(heredoc, /*process_bkslash:*/ 1, /*unbackslash:*/ 1);
6308 len = strlen(heredoc);
6310 close(redir->rd_fd); /* often saves dup2+close in xmove_fd */
6312 xmove_fd(pair.rd, redir->rd_fd);
6314 /* Try writing without forking. Newer kernels have
6315 * dynamically growing pipes. Must use non-blocking write! */
6318 written = write(pair.wr, heredoc, len);
6329 ndelay_off(pair.wr);
6331 /* Okay, pipe buffer was not big enough */
6332 /* Note: we must not create a stray child (bastard? :)
6333 * for the unsuspecting parent process. Child creates a grandchild
6334 * and exits before parent execs the process which consumes heredoc
6335 * (that exec happens after we return from this function) */
6342 disable_restore_tty_pgrp_on_exit();
6343 pid = BB_MMU ? xfork() : xvfork();
6347 close(redir->rd_fd); /* read side of the pipe */
6349 full_write(pair.wr, heredoc, len); /* may loop or block */
6352 /* Delegate blocking writes to another process */
6353 xmove_fd(pair.wr, STDOUT_FILENO);
6354 re_execute_shell(&to_free, heredoc, NULL, NULL, NULL);
6358 #if ENABLE_HUSH_FAST
6360 //bb_error_msg("[%d] fork in setup_heredoc: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
6362 enable_restore_tty_pgrp_on_exit();
6368 wait(NULL); /* wait till child has died */
6371 /* fd: redirect wants this fd to be used (e.g. 3>file).
6372 * Move all conflicting internally used fds,
6373 * and remember them so that we can restore them later.
6375 static int save_fds_on_redirect(int fd, int squirrel[3])
6378 /* Handle redirects of fds 0,1,2 */
6380 /* If we collide with an already moved stdio fd... */
6381 if (fd == squirrel[0]) {
6382 squirrel[0] = xdup_and_close(squirrel[0], F_DUPFD);
6385 if (fd == squirrel[1]) {
6386 squirrel[1] = xdup_and_close(squirrel[1], F_DUPFD);
6389 if (fd == squirrel[2]) {
6390 squirrel[2] = xdup_and_close(squirrel[2], F_DUPFD);
6393 /* If we are about to redirect stdio fd, and did not yet move it... */
6394 if (fd <= 2 && squirrel[fd] < 0) {
6395 /* We avoid taking stdio fds */
6396 squirrel[fd] = fcntl(fd, F_DUPFD, 10);
6397 if (squirrel[fd] < 0 && errno != EBADF)
6399 return 0; /* "we did not close fd" */
6403 #if ENABLE_HUSH_INTERACTIVE
6404 if (fd != 0 && fd == G.interactive_fd) {
6405 G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC);
6410 /* Are we called from setup_redirects(squirrel==NULL)? Two cases:
6411 * (1) Redirect in a forked child. No need to save FILEs' fds,
6412 * we aren't going to use them anymore, ok to trash.
6413 * (2) "exec 3>FILE". Bummer. We can save FILEs' fds,
6414 * but how are we doing to use them?
6415 * "fileno(fd) = new_fd" can't be done.
6420 return save_FILEs_on_redirect(fd);
6423 static void restore_redirects(int squirrel[3])
6426 for (i = 0; i <= 2; i++) {
6429 /* We simply die on error */
6434 /* Moved G.interactive_fd stays on new fd, not doing anything for it */
6436 restore_redirected_FILEs();
6439 /* squirrel != NULL means we squirrel away copies of stdin, stdout,
6440 * and stderr if they are redirected. */
6441 static int setup_redirects(struct command *prog, int squirrel[])
6444 struct redir_struct *redir;
6446 for (redir = prog->redirects; redir; redir = redir->next) {
6447 if (redir->rd_type == REDIRECT_HEREDOC2) {
6448 /* "rd_fd<<HERE" case */
6449 save_fds_on_redirect(redir->rd_fd, squirrel);
6450 /* for REDIRECT_HEREDOC2, rd_filename holds _contents_
6452 debug_printf_parse("set heredoc '%s'\n",
6453 redir->rd_filename);
6454 setup_heredoc(redir);
6458 if (redir->rd_dup == REDIRFD_TO_FILE) {
6459 /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */
6461 if (redir->rd_filename == NULL) {
6464 * "cmd >" (no filename)
6465 * "cmd > <file" (2nd redirect starts too early)
6467 die_if_script("syntax error: %s", "invalid redirect");
6470 mode = redir_table[redir->rd_type].mode;
6471 p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1);
6472 openfd = open_or_warn(p, mode);
6475 /* Error message from open_or_warn can be lost
6476 * if stderr has been redirected, but bash
6477 * and ash both lose it as well
6478 * (though zsh doesn't!)
6483 /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */
6484 openfd = redir->rd_dup;
6487 if (openfd != redir->rd_fd) {
6488 int closed = save_fds_on_redirect(redir->rd_fd, squirrel);
6489 if (openfd == REDIRFD_CLOSE) {
6490 /* "rd_fd >&-" means "close me" */
6492 /* ^^^ optimization: saving may already
6493 * have closed it. If not... */
6494 close(redir->rd_fd);
6497 xdup2(openfd, redir->rd_fd);
6498 if (redir->rd_dup == REDIRFD_TO_FILE)
6499 /* "rd_fd > FILE" */
6501 /* else: "rd_fd > rd_dup" */
6508 static char *find_in_path(const char *arg)
6511 const char *PATH = get_local_var_value("PATH");
6517 const char *end = strchrnul(PATH, ':');
6518 int sz = end - PATH; /* must be int! */
6522 ret = xasprintf("%.*s/%s", sz, PATH, arg);
6524 /* We have xxx::yyyy in $PATH,
6525 * it means "use current dir" */
6528 if (access(ret, F_OK) == 0)
6541 static const struct built_in_command *find_builtin_helper(const char *name,
6542 const struct built_in_command *x,
6543 const struct built_in_command *end)
6546 if (strcmp(name, x->b_cmd) != 0) {
6550 debug_printf_exec("found builtin '%s'\n", name);
6555 static const struct built_in_command *find_builtin1(const char *name)
6557 return find_builtin_helper(name, bltins1, &bltins1[ARRAY_SIZE(bltins1)]);
6559 static const struct built_in_command *find_builtin(const char *name)
6561 const struct built_in_command *x = find_builtin1(name);
6564 return find_builtin_helper(name, bltins2, &bltins2[ARRAY_SIZE(bltins2)]);
6567 #if ENABLE_HUSH_FUNCTIONS
6568 static struct function **find_function_slot(const char *name)
6570 struct function **funcpp = &G.top_func;
6572 if (strcmp(name, (*funcpp)->name) == 0) {
6575 funcpp = &(*funcpp)->next;
6580 static const struct function *find_function(const char *name)
6582 const struct function *funcp = *find_function_slot(name);
6584 debug_printf_exec("found function '%s'\n", name);
6588 /* Note: takes ownership on name ptr */
6589 static struct function *new_function(char *name)
6591 struct function **funcpp = find_function_slot(name);
6592 struct function *funcp = *funcpp;
6594 if (funcp != NULL) {
6595 struct command *cmd = funcp->parent_cmd;
6596 debug_printf_exec("func %p parent_cmd %p\n", funcp, cmd);
6598 debug_printf_exec("freeing & replacing function '%s'\n", funcp->name);
6600 /* Note: if !funcp->body, do not free body_as_string!
6601 * This is a special case of "-F name body" function:
6602 * body_as_string was not malloced! */
6604 free_pipe_list(funcp->body);
6606 free(funcp->body_as_string);
6610 debug_printf_exec("reinserting in tree & replacing function '%s'\n", funcp->name);
6611 cmd->argv[0] = funcp->name;
6612 cmd->group = funcp->body;
6614 cmd->group_as_string = funcp->body_as_string;
6618 debug_printf_exec("remembering new function '%s'\n", name);
6619 funcp = *funcpp = xzalloc(sizeof(*funcp));
6620 /*funcp->next = NULL;*/
6627 static void unset_func(const char *name)
6629 struct function **funcpp = find_function_slot(name);
6630 struct function *funcp = *funcpp;
6632 if (funcp != NULL) {
6633 debug_printf_exec("freeing function '%s'\n", funcp->name);
6634 *funcpp = funcp->next;
6635 /* funcp is unlinked now, deleting it.
6636 * Note: if !funcp->body, the function was created by
6637 * "-F name body", do not free ->body_as_string
6638 * and ->name as they were not malloced. */
6640 free_pipe_list(funcp->body);
6643 free(funcp->body_as_string);
6651 #define exec_function(to_free, funcp, argv) \
6652 exec_function(funcp, argv)
6654 static void exec_function(char ***to_free,
6655 const struct function *funcp,
6656 char **argv) NORETURN;
6657 static void exec_function(char ***to_free,
6658 const struct function *funcp,
6664 argv[0] = G.global_argv[0];
6665 G.global_argv = argv;
6669 /* On MMU, funcp->body is always non-NULL */
6670 n = run_list(funcp->body);
6674 re_execute_shell(to_free,
6675 funcp->body_as_string,
6682 static int run_function(const struct function *funcp, char **argv)
6688 save_and_replace_G_args(&sv, argv);
6690 /* "we are in function, ok to use return" */
6691 sv_flg = G_flag_return_in_progress;
6692 G_flag_return_in_progress = -1;
6693 # if ENABLE_HUSH_LOCAL
6694 G.func_nest_level++;
6697 /* On MMU, funcp->body is always non-NULL */
6700 /* Function defined by -F */
6701 parse_and_run_string(funcp->body_as_string);
6702 rc = G.last_exitcode;
6706 rc = run_list(funcp->body);
6709 # if ENABLE_HUSH_LOCAL
6711 struct variable *var;
6712 struct variable **var_pp;
6714 var_pp = &G.top_var;
6715 while ((var = *var_pp) != NULL) {
6716 if (var->func_nest_level < G.func_nest_level) {
6717 var_pp = &var->next;
6721 if (var->flg_export)
6722 bb_unsetenv(var->varstr);
6723 /* Remove from global list */
6724 *var_pp = var->next;
6730 G.func_nest_level--;
6733 G_flag_return_in_progress = sv_flg;
6735 restore_G_args(&sv, argv);
6739 #endif /* ENABLE_HUSH_FUNCTIONS */
6743 #define exec_builtin(to_free, x, argv) \
6744 exec_builtin(x, argv)
6746 #define exec_builtin(to_free, x, argv) \
6747 exec_builtin(to_free, argv)
6749 static void exec_builtin(char ***to_free,
6750 const struct built_in_command *x,
6751 char **argv) NORETURN;
6752 static void exec_builtin(char ***to_free,
6753 const struct built_in_command *x,
6759 rcode = x->b_function(argv);
6764 /* On NOMMU, we must never block!
6765 * Example: { sleep 99 | read line; } & echo Ok
6767 re_execute_shell(to_free,
6776 static void execvp_or_die(char **argv) NORETURN;
6777 static void execvp_or_die(char **argv)
6780 debug_printf_exec("execing '%s'\n", argv[0]);
6781 /* Don't propagate SIG_IGN to the child */
6782 if (SPECIAL_JOBSTOP_SIGS != 0)
6783 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6784 execvp(argv[0], argv);
6786 if (errno == EACCES) e = 126;
6787 if (errno == ENOENT) e = 127;
6788 bb_perror_msg("can't execute '%s'", argv[0]);
6792 #if ENABLE_HUSH_MODE_X
6793 static void dump_cmd_in_x_mode(char **argv)
6795 if (G_x_mode && argv) {
6796 /* We want to output the line in one write op */
6804 len += strlen(argv[n++]) + 1;
6810 p += sprintf(p, " %s", argv[n++]);
6818 # define dump_cmd_in_x_mode(argv) ((void)0)
6822 #define pseudo_exec_argv(nommu_save, argv, assignment_cnt, argv_expanded) \
6823 pseudo_exec_argv(argv, assignment_cnt, argv_expanded)
6824 #define pseudo_exec(nommu_save, command, argv_expanded) \
6825 pseudo_exec(command, argv_expanded)
6828 /* Called after [v]fork() in run_pipe, or from builtin_exec.
6830 * Don't exit() here. If you don't exec, use _exit instead.
6831 * The at_exit handlers apparently confuse the calling process,
6832 * in particular stdin handling. Not sure why? -- because of vfork! (vda)
6834 static void pseudo_exec_argv(nommu_save_t *nommu_save,
6835 char **argv, int assignment_cnt,
6836 char **argv_expanded) NORETURN;
6837 static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
6838 char **argv, int assignment_cnt,
6839 char **argv_expanded)
6843 new_env = expand_assignments(argv, assignment_cnt);
6844 dump_cmd_in_x_mode(new_env);
6846 if (!argv[assignment_cnt]) {
6847 /* Case when we are here: ... | var=val | ...
6848 * (note that we do not exit early, i.e., do not optimize out
6849 * expand_assignments(): think about ... | var=`sleep 1` | ...
6851 free_strings(new_env);
6852 _exit(EXIT_SUCCESS);
6856 set_vars_and_save_old(new_env);
6857 free(new_env); /* optional */
6858 /* we can also destroy set_vars_and_save_old's return value,
6861 nommu_save->new_env = new_env;
6862 nommu_save->old_vars = set_vars_and_save_old(new_env);
6865 if (argv_expanded) {
6866 argv = argv_expanded;
6868 argv = expand_strvec_to_strvec(argv + assignment_cnt);
6870 nommu_save->argv = argv;
6873 dump_cmd_in_x_mode(argv);
6875 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6876 if (strchr(argv[0], '/') != NULL)
6880 /* Check if the command matches any of the builtins.
6881 * Depending on context, this might be redundant. But it's
6882 * easier to waste a few CPU cycles than it is to figure out
6883 * if this is one of those cases.
6886 /* On NOMMU, it is more expensive to re-execute shell
6887 * just in order to run echo or test builtin.
6888 * It's better to skip it here and run corresponding
6889 * non-builtin later. */
6890 const struct built_in_command *x;
6891 x = BB_MMU ? find_builtin(argv[0]) : find_builtin1(argv[0]);
6893 exec_builtin(&nommu_save->argv_from_re_execing, x, argv);
6896 #if ENABLE_HUSH_FUNCTIONS
6897 /* Check if the command matches any functions */
6899 const struct function *funcp = find_function(argv[0]);
6901 exec_function(&nommu_save->argv_from_re_execing, funcp, argv);
6906 #if ENABLE_FEATURE_SH_STANDALONE
6907 /* Check if the command matches any busybox applets */
6909 int a = find_applet_by_name(argv[0]);
6911 # if BB_MMU /* see above why on NOMMU it is not allowed */
6912 if (APPLET_IS_NOEXEC(a)) {
6913 /* Do not leak open fds from opened script files etc */
6914 close_all_FILE_list();
6915 debug_printf_exec("running applet '%s'\n", argv[0]);
6916 run_applet_no_and_exit(a, argv);
6919 /* Re-exec ourselves */
6920 debug_printf_exec("re-execing applet '%s'\n", argv[0]);
6921 /* Don't propagate SIG_IGN to the child */
6922 if (SPECIAL_JOBSTOP_SIGS != 0)
6923 switch_off_special_sigs(G.special_sig_mask & SPECIAL_JOBSTOP_SIGS);
6924 execv(bb_busybox_exec_path, argv);
6925 /* If they called chroot or otherwise made the binary no longer
6926 * executable, fall through */
6931 #if ENABLE_FEATURE_SH_STANDALONE || BB_MMU
6934 execvp_or_die(argv);
6937 /* Called after [v]fork() in run_pipe
6939 static void pseudo_exec(nommu_save_t *nommu_save,
6940 struct command *command,
6941 char **argv_expanded) NORETURN;
6942 static void pseudo_exec(nommu_save_t *nommu_save,
6943 struct command *command,
6944 char **argv_expanded)
6946 if (command->argv) {
6947 pseudo_exec_argv(nommu_save, command->argv,
6948 command->assignment_cnt, argv_expanded);
6951 if (command->group) {
6952 /* Cases when we are here:
6955 * ... | ( list ) | ...
6956 * ... | { list } | ...
6960 debug_printf_exec("pseudo_exec: run_list\n");
6961 reset_traps_to_defaults();
6962 rcode = run_list(command->group);
6963 /* OK to leak memory by not calling free_pipe_list,
6964 * since this process is about to exit */
6967 re_execute_shell(&nommu_save->argv_from_re_execing,
6968 command->group_as_string,
6975 /* Case when we are here: ... | >file */
6976 debug_printf_exec("pseudo_exec'ed null command\n");
6977 _exit(EXIT_SUCCESS);
6981 static const char *get_cmdtext(struct pipe *pi)
6987 /* This is subtle. ->cmdtext is created only on first backgrounding.
6988 * (Think "cat, <ctrl-z>, fg, <ctrl-z>, fg, <ctrl-z>...." here...)
6989 * On subsequent bg argv is trashed, but we won't use it */
6993 argv = pi->cmds[0].argv;
6995 pi->cmdtext = xzalloc(1);
7000 len += strlen(*argv) + 1;
7004 argv = pi->cmds[0].argv;
7006 p = stpcpy(p, *argv);
7013 static void insert_bg_job(struct pipe *pi)
7015 struct pipe *job, **jobp;
7018 /* Linear search for the ID of the job to use */
7020 for (job = G.job_list; job; job = job->next)
7021 if (job->jobid >= pi->jobid)
7022 pi->jobid = job->jobid + 1;
7024 /* Add job to the list of running jobs */
7026 while ((job = *jobp) != NULL)
7028 job = *jobp = xmalloc(sizeof(*job));
7030 *job = *pi; /* physical copy */
7032 job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds);
7033 /* Cannot copy entire pi->cmds[] vector! This causes double frees */
7034 for (i = 0; i < pi->num_cmds; i++) {
7035 job->cmds[i].pid = pi->cmds[i].pid;
7036 /* all other fields are not used and stay zero */
7038 job->cmdtext = xstrdup(get_cmdtext(pi));
7040 if (G_interactive_fd)
7041 printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext);
7042 G.last_jobid = job->jobid;
7045 static void remove_bg_job(struct pipe *pi)
7047 struct pipe *prev_pipe;
7049 if (pi == G.job_list) {
7050 G.job_list = pi->next;
7052 prev_pipe = G.job_list;
7053 while (prev_pipe->next != pi)
7054 prev_pipe = prev_pipe->next;
7055 prev_pipe->next = pi->next;
7058 G.last_jobid = G.job_list->jobid;
7063 /* Remove a backgrounded job */
7064 static void delete_finished_bg_job(struct pipe *pi)
7071 static int job_exited_or_stopped(struct pipe *pi)
7075 if (pi->alive_cmds != pi->stopped_cmds)
7078 /* All processes in fg pipe have exited or stopped */
7082 rcode = pi->cmds[i].cmd_exitcode;
7083 /* usually last process gives overall exitstatus,
7084 * but with "set -o pipefail", last *failed* process does */
7085 if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0)
7088 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7092 static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status)
7099 dead = WIFEXITED(status) || WIFSIGNALED(status);
7102 if (WIFSTOPPED(status))
7103 debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n",
7104 childpid, WSTOPSIG(status), WEXITSTATUS(status));
7105 if (WIFSIGNALED(status))
7106 debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n",
7107 childpid, WTERMSIG(status), WEXITSTATUS(status));
7108 if (WIFEXITED(status))
7109 debug_printf_jobs("pid %d exited, exitcode %d\n",
7110 childpid, WEXITSTATUS(status));
7112 /* Were we asked to wait for a fg pipe? */
7114 i = fg_pipe->num_cmds;
7119 debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid);
7120 if (fg_pipe->cmds[i].pid != childpid)
7124 fg_pipe->cmds[i].pid = 0;
7125 fg_pipe->alive_cmds--;
7126 ex = WEXITSTATUS(status);
7127 /* bash prints killer signal's name for *last*
7128 * process in pipe (prints just newline for SIGINT/SIGPIPE).
7129 * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT)
7131 if (WIFSIGNALED(status)) {
7132 int sig = WTERMSIG(status);
7133 if (i == fg_pipe->num_cmds-1)
7134 /* TODO: use strsignal() instead for bash compat? but that's bloat... */
7135 puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig));
7136 /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */
7137 /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here?
7138 * Maybe we need to use sig | 128? */
7141 fg_pipe->cmds[i].cmd_exitcode = ex;
7143 fg_pipe->stopped_cmds++;
7145 debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n",
7146 fg_pipe->alive_cmds, fg_pipe->stopped_cmds);
7147 rcode = job_exited_or_stopped(fg_pipe);
7149 /* Note: *non-interactive* bash does not continue if all processes in fg pipe
7150 * are stopped. Testcase: "cat | cat" in a script (not on command line!)
7151 * and "killall -STOP cat" */
7152 if (G_interactive_fd) {
7154 if (fg_pipe->alive_cmds != 0)
7155 insert_bg_job(fg_pipe);
7159 if (fg_pipe->alive_cmds == 0)
7162 /* There are still running processes in the fg_pipe */
7165 /* It wasnt in fg_pipe, look for process in bg pipes */
7169 /* We were asked to wait for bg or orphaned children */
7170 /* No need to remember exitcode in this case */
7171 for (pi = G.job_list; pi; pi = pi->next) {
7172 for (i = 0; i < pi->num_cmds; i++) {
7173 if (pi->cmds[i].pid == childpid)
7174 goto found_pi_and_prognum;
7177 /* Happens when shell is used as init process (init=/bin/sh) */
7178 debug_printf("checkjobs: pid %d was not in our list!\n", childpid);
7179 return -1; /* this wasn't a process from fg_pipe */
7181 found_pi_and_prognum:
7184 pi->cmds[i].pid = 0;
7185 pi->cmds[i].cmd_exitcode = WEXITSTATUS(status);
7186 if (WIFSIGNALED(status))
7187 pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status);
7189 if (!pi->alive_cmds) {
7190 if (G_interactive_fd)
7191 printf(JOB_STATUS_FORMAT, pi->jobid,
7192 "Done", pi->cmdtext);
7193 delete_finished_bg_job(pi);
7200 return -1; /* this wasn't a process from fg_pipe */
7203 /* Check to see if any processes have exited -- if they have,
7204 * figure out why and see if a job has completed.
7206 * If non-NULL fg_pipe: wait for its completion or stop.
7207 * Return its exitcode or zero if stopped.
7209 * Alternatively (fg_pipe == NULL, waitfor_pid != 0):
7210 * waitpid(WNOHANG), if waitfor_pid exits or stops, return exitcode+1,
7211 * else return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7212 * or 0 if no children changed status.
7214 * Alternatively (fg_pipe == NULL, waitfor_pid == 0),
7215 * return <0 if waitpid errors out (e.g. ECHILD: nothing to wait for)
7216 * or 0 if no children changed status.
7218 static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid)
7224 debug_printf_jobs("checkjobs %p\n", fg_pipe);
7226 attributes = WUNTRACED;
7227 if (fg_pipe == NULL)
7228 attributes |= WNOHANG;
7231 #if ENABLE_HUSH_FAST
7232 if (G.handled_SIGCHLD == G.count_SIGCHLD) {
7233 //bb_error_msg("[%d] checkjobs: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d children?:%d fg_pipe:%p",
7234 //getpid(), G.count_SIGCHLD, G.handled_SIGCHLD, G.we_have_children, fg_pipe);
7235 /* There was neither fork nor SIGCHLD since last waitpid */
7236 /* Avoid doing waitpid syscall if possible */
7237 if (!G.we_have_children) {
7241 if (fg_pipe == NULL) { /* is WNOHANG set? */
7242 /* We have children, but they did not exit
7243 * or stop yet (we saw no SIGCHLD) */
7246 /* else: !WNOHANG, waitpid will block, can't short-circuit */
7250 /* Do we do this right?
7251 * bash-3.00# sleep 20 | false
7253 * [3]+ Stopped sleep 20 | false
7254 * bash-3.00# echo $?
7255 * 1 <========== bg pipe is not fully done, but exitcode is already known!
7256 * [hush 1.14.0: yes we do it right]
7260 #if ENABLE_HUSH_FAST
7262 i = G.count_SIGCHLD;
7264 childpid = waitpid(-1, &status, attributes);
7265 if (childpid <= 0) {
7266 if (childpid && errno != ECHILD)
7267 bb_perror_msg("waitpid");
7268 #if ENABLE_HUSH_FAST
7269 else { /* Until next SIGCHLD, waitpid's are useless */
7270 G.we_have_children = (childpid == 0);
7271 G.handled_SIGCHLD = i;
7272 //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7275 /* ECHILD (no children), or 0 (no change in children status) */
7279 rcode = process_wait_result(fg_pipe, childpid, status);
7281 /* fg_pipe exited or stopped */
7284 if (childpid == waitfor_pid) {
7285 debug_printf_exec("childpid==waitfor_pid:%d status:0x%08x\n", childpid, status);
7286 rcode = WEXITSTATUS(status);
7287 if (WIFSIGNALED(status))
7288 rcode = 128 + WTERMSIG(status);
7289 if (WIFSTOPPED(status))
7290 /* bash: "cmd & wait $!" and cmd stops: $? = 128 + stopsig */
7291 rcode = 128 + WSTOPSIG(status);
7293 break; /* "wait PID" called us, give it exitcode+1 */
7295 /* This wasn't one of our processes, or */
7296 /* fg_pipe still has running processes, do waitpid again */
7297 } /* while (waitpid succeeds)... */
7303 static int checkjobs_and_fg_shell(struct pipe *fg_pipe)
7306 int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/);
7307 if (G_saved_tty_pgrp) {
7308 /* Job finished, move the shell to the foreground */
7309 p = getpgrp(); /* our process group id */
7310 debug_printf_jobs("fg'ing ourself: getpgrp()=%d\n", (int)p);
7311 tcsetpgrp(G_interactive_fd, p);
7317 /* Start all the jobs, but don't wait for anything to finish.
7320 * Return code is normally -1, when the caller has to wait for children
7321 * to finish to determine the exit status of the pipe. If the pipe
7322 * is a simple builtin command, however, the action is done by the
7323 * time run_pipe returns, and the exit code is provided as the
7326 * Returns -1 only if started some children. IOW: we have to
7327 * mask out retvals of builtins etc with 0xff!
7329 * The only case when we do not need to [v]fork is when the pipe
7330 * is single, non-backgrounded, non-subshell command. Examples:
7331 * cmd ; ... { list } ; ...
7332 * cmd && ... { list } && ...
7333 * cmd || ... { list } || ...
7334 * If it is, then we can run cmd as a builtin, NOFORK,
7335 * or (if SH_STANDALONE) an applet, and we can run the { list }
7336 * with run_list. If it isn't one of these, we fork and exec cmd.
7338 * Cases when we must fork:
7339 * non-single: cmd | cmd
7340 * backgrounded: cmd & { list } &
7341 * subshell: ( list ) [&]
7343 #if !ENABLE_HUSH_MODE_X
7344 #define redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel, argv_expanded) \
7345 redirect_and_varexp_helper(new_env_p, old_vars_p, command, squirrel)
7347 static int redirect_and_varexp_helper(char ***new_env_p,
7348 struct variable **old_vars_p,
7349 struct command *command,
7351 char **argv_expanded)
7353 /* setup_redirects acts on file descriptors, not FILEs.
7354 * This is perfect for work that comes after exec().
7355 * Is it really safe for inline use? Experimentally,
7356 * things seem to work. */
7357 int rcode = setup_redirects(command, squirrel);
7359 char **new_env = expand_assignments(command->argv, command->assignment_cnt);
7360 *new_env_p = new_env;
7361 dump_cmd_in_x_mode(new_env);
7362 dump_cmd_in_x_mode(argv_expanded);
7364 *old_vars_p = set_vars_and_save_old(new_env);
7368 static NOINLINE int run_pipe(struct pipe *pi)
7370 static const char *const null_ptr = NULL;
7374 struct command *command;
7375 char **argv_expanded;
7377 /* it is not always needed, but we aim to smaller code */
7378 int squirrel[] = { -1, -1, -1 };
7381 debug_printf_exec("run_pipe start: members:%d\n", pi->num_cmds);
7384 /* Testcase: set -- q w e; (IFS='' echo "$*"; IFS=''; echo "$*"); echo "$*"
7385 * Result should be 3 lines: q w e, qwe, q w e
7387 G.ifs = get_local_var_value("IFS");
7391 IF_HUSH_JOB(pi->pgrp = -1;)
7392 pi->stopped_cmds = 0;
7393 command = &pi->cmds[0];
7394 argv_expanded = NULL;
7396 if (pi->num_cmds != 1
7397 || pi->followup == PIPE_BG
7398 || command->cmd_type == CMD_SUBSHELL
7405 debug_printf_exec(": group:%p argv:'%s'\n",
7406 command->group, command->argv ? command->argv[0] : "NONE");
7408 if (command->group) {
7409 #if ENABLE_HUSH_FUNCTIONS
7410 if (command->cmd_type == CMD_FUNCDEF) {
7411 /* "executing" func () { list } */
7412 struct function *funcp;
7414 funcp = new_function(command->argv[0]);
7415 /* funcp->name is already set to argv[0] */
7416 funcp->body = command->group;
7418 funcp->body_as_string = command->group_as_string;
7419 command->group_as_string = NULL;
7421 command->group = NULL;
7422 command->argv[0] = NULL;
7423 debug_printf_exec("cmd %p has child func at %p\n", command, funcp);
7424 funcp->parent_cmd = command;
7425 command->child_func = funcp;
7427 debug_printf_exec("run_pipe: return EXIT_SUCCESS\n");
7429 return EXIT_SUCCESS;
7433 debug_printf("non-subshell group\n");
7434 rcode = 1; /* exitcode if redir failed */
7435 if (setup_redirects(command, squirrel) == 0) {
7436 debug_printf_exec(": run_list\n");
7437 rcode = run_list(command->group) & 0xff;
7439 restore_redirects(squirrel);
7440 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7442 debug_printf_exec("run_pipe: return %d\n", rcode);
7446 argv = command->argv ? command->argv : (char **) &null_ptr;
7448 const struct built_in_command *x;
7449 #if ENABLE_HUSH_FUNCTIONS
7450 const struct function *funcp;
7454 char **new_env = NULL;
7455 struct variable *old_vars = NULL;
7457 if (argv[command->assignment_cnt] == NULL) {
7458 /* Assignments, but no command */
7459 /* Ensure redirects take effect (that is, create files).
7460 * Try "a=t >file" */
7461 #if 0 /* A few cases in testsuite fail with this code. FIXME */
7462 rcode = redirect_and_varexp_helper(&new_env, /*old_vars:*/ NULL, command, squirrel, /*argv_expanded:*/ NULL);
7463 /* Set shell variables */
7467 set_local_var(*argv, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7468 /* Do we need to flag set_local_var() errors?
7469 * "assignment to readonly var" and "putenv error"
7474 /* Redirect error sets $? to 1. Otherwise,
7475 * if evaluating assignment value set $?, retain it.
7476 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7478 rcode = G.last_exitcode;
7479 /* Exit, _skipping_ variable restoring code: */
7480 goto clean_up_and_ret0;
7482 #else /* Older, bigger, but more correct code */
7484 rcode = setup_redirects(command, squirrel);
7485 restore_redirects(squirrel);
7486 /* Set shell variables */
7488 bb_putchar_stderr('+');
7490 char *p = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7492 fprintf(stderr, " %s", p);
7493 debug_printf_exec("set shell var:'%s'->'%s'\n",
7495 set_local_var(p, /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7496 /* Do we need to flag set_local_var() errors?
7497 * "assignment to readonly var" and "putenv error"
7502 bb_putchar_stderr('\n');
7503 /* Redirect error sets $? to 1. Otherwise,
7504 * if evaluating assignment value set $?, retain it.
7505 * Try "false; q=`exit 2`; echo $?" - should print 2: */
7507 rcode = G.last_exitcode;
7508 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7510 debug_printf_exec("run_pipe: return %d\n", rcode);
7515 /* Expand the rest into (possibly) many strings each */
7516 #if ENABLE_HUSH_BASH_COMPAT
7517 if (command->cmd_type == CMD_SINGLEWORD_NOGLOB) {
7518 argv_expanded = expand_strvec_to_strvec_singleword_noglob(argv + command->assignment_cnt);
7522 argv_expanded = expand_strvec_to_strvec(argv + command->assignment_cnt);
7525 /* if someone gives us an empty string: `cmd with empty output` */
7526 if (!argv_expanded[0]) {
7527 free(argv_expanded);
7529 return G.last_exitcode;
7532 x = find_builtin(argv_expanded[0]);
7533 #if ENABLE_HUSH_FUNCTIONS
7536 funcp = find_function(argv_expanded[0]);
7540 if (x->b_function == builtin_exec && argv_expanded[1] == NULL) {
7541 debug_printf("exec with redirects only\n");
7542 rcode = setup_redirects(command, NULL);
7543 /* rcode=1 can be if redir file can't be opened */
7544 goto clean_up_and_ret1;
7547 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7550 debug_printf_exec(": builtin '%s' '%s'...\n",
7551 x->b_cmd, argv_expanded[1]);
7553 rcode = x->b_function(argv_expanded) & 0xff;
7556 #if ENABLE_HUSH_FUNCTIONS
7558 # if ENABLE_HUSH_LOCAL
7559 struct variable **sv;
7560 sv = G.shadowed_vars_pp;
7561 G.shadowed_vars_pp = &old_vars;
7563 debug_printf_exec(": function '%s' '%s'...\n",
7564 funcp->name, argv_expanded[1]);
7565 rcode = run_function(funcp, argv_expanded) & 0xff;
7566 # if ENABLE_HUSH_LOCAL
7567 G.shadowed_vars_pp = sv;
7573 unset_vars(new_env);
7575 /* clean_up_and_ret0: */
7576 restore_redirects(squirrel);
7578 free(argv_expanded);
7579 IF_HAS_KEYWORDS(if (pi->pi_inverted) rcode = !rcode;)
7581 debug_printf_exec("run_pipe return %d\n", rcode);
7585 if (ENABLE_FEATURE_SH_NOFORK) {
7586 int n = find_applet_by_name(argv_expanded[0]);
7587 if (n >= 0 && APPLET_IS_NOFORK(n)) {
7588 rcode = redirect_and_varexp_helper(&new_env, &old_vars, command, squirrel, argv_expanded);
7590 debug_printf_exec(": run_nofork_applet '%s' '%s'...\n",
7591 argv_expanded[0], argv_expanded[1]);
7592 rcode = run_nofork_applet(n, argv_expanded);
7594 goto clean_up_and_ret;
7597 /* It is neither builtin nor applet. We must fork. */
7601 /* NB: argv_expanded may already be created, and that
7602 * might include `cmd` runs! Do not rerun it! We *must*
7603 * use argv_expanded if it's non-NULL */
7605 /* Going to fork a child per each pipe member */
7610 while (cmd_no < pi->num_cmds) {
7611 struct fd_pair pipefds;
7613 volatile nommu_save_t nommu_save;
7614 nommu_save.new_env = NULL;
7615 nommu_save.old_vars = NULL;
7616 nommu_save.argv = NULL;
7617 nommu_save.argv_from_re_execing = NULL;
7619 command = &pi->cmds[cmd_no];
7621 if (command->argv) {
7622 debug_printf_exec(": pipe member '%s' '%s'...\n",
7623 command->argv[0], command->argv[1]);
7625 debug_printf_exec(": pipe member with no argv\n");
7628 /* pipes are inserted between pairs of commands */
7631 if (cmd_no < pi->num_cmds)
7632 xpiped_pair(pipefds);
7634 command->pid = BB_MMU ? fork() : vfork();
7635 if (!command->pid) { /* child */
7637 disable_restore_tty_pgrp_on_exit();
7638 CLEAR_RANDOM_T(&G.random_gen); /* or else $RANDOM repeats in child */
7640 /* Every child adds itself to new process group
7641 * with pgid == pid_of_first_child_in_pipe */
7642 if (G.run_list_level == 1 && G_interactive_fd) {
7645 if (pgrp < 0) /* true for 1st process only */
7647 if (setpgid(0, pgrp) == 0
7648 && pi->followup != PIPE_BG
7649 && G_saved_tty_pgrp /* we have ctty */
7651 /* We do it in *every* child, not just first,
7653 tcsetpgrp(G_interactive_fd, pgrp);
7657 if (pi->alive_cmds == 0 && pi->followup == PIPE_BG) {
7658 /* 1st cmd in backgrounded pipe
7659 * should have its stdin /dev/null'ed */
7661 if (open(bb_dev_null, O_RDONLY))
7662 xopen("/", O_RDONLY);
7664 xmove_fd(next_infd, 0);
7666 xmove_fd(pipefds.wr, 1);
7669 /* Like bash, explicit redirects override pipes,
7670 * and the pipe fd (fd#1) is available for dup'ing:
7671 * "cmd1 2>&1 | cmd2": fd#1 is duped to fd#2, thus stderr
7672 * of cmd1 goes into pipe.
7674 if (setup_redirects(command, NULL)) {
7675 /* Happens when redir file can't be opened:
7676 * $ hush -c 'echo FOO >&2 | echo BAR 3>/qwe/rty; echo BAZ'
7678 * hush: can't open '/qwe/rty': No such file or directory
7680 * (echo BAR is not executed, it hits _exit(1) below)
7685 /* Stores to nommu_save list of env vars putenv'ed
7686 * (NOMMU, on MMU we don't need that) */
7687 /* cast away volatility... */
7688 pseudo_exec((nommu_save_t*) &nommu_save, command, argv_expanded);
7689 /* pseudo_exec() does not return */
7692 /* parent or error */
7693 #if ENABLE_HUSH_FAST
7695 //bb_error_msg("[%d] fork in run_pipe: G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD);
7697 enable_restore_tty_pgrp_on_exit();
7699 /* Clean up after vforked child */
7700 free(nommu_save.argv);
7701 free(nommu_save.argv_from_re_execing);
7702 unset_vars(nommu_save.new_env);
7703 add_vars(nommu_save.old_vars);
7705 free(argv_expanded);
7706 argv_expanded = NULL;
7707 if (command->pid < 0) { /* [v]fork failed */
7708 /* Clearly indicate, was it fork or vfork */
7709 bb_perror_msg(BB_MMU ? "vfork"+1 : "vfork");
7713 /* Second and next children need to know pid of first one */
7715 pi->pgrp = command->pid;
7721 if (cmd_no < pi->num_cmds)
7723 /* Pass read (output) pipe end to next iteration */
7724 next_infd = pipefds.rd;
7727 if (!pi->alive_cmds) {
7729 debug_printf_exec("run_pipe return 1 (all forks failed, no children)\n");
7734 debug_printf_exec("run_pipe return -1 (%u children started)\n", pi->alive_cmds);
7738 /* NB: called by pseudo_exec, and therefore must not modify any
7739 * global data until exec/_exit (we can be a child after vfork!) */
7740 static int run_list(struct pipe *pi)
7742 #if ENABLE_HUSH_CASE
7743 char *case_word = NULL;
7745 #if ENABLE_HUSH_LOOPS
7746 struct pipe *loop_top = NULL;
7747 char **for_lcur = NULL;
7748 char **for_list = NULL;
7750 smallint last_followup;
7752 #if ENABLE_HUSH_IF || ENABLE_HUSH_CASE
7753 smalluint cond_code = 0;
7755 enum { cond_code = 0 };
7758 smallint rword; /* RES_foo */
7759 smallint last_rword; /* ditto */
7762 debug_printf_exec("run_list start lvl %d\n", G.run_list_level);
7765 #if ENABLE_HUSH_LOOPS
7766 /* Check syntax for "for" */
7769 for (cpipe = pi; cpipe; cpipe = cpipe->next) {
7770 if (cpipe->res_word != RES_FOR && cpipe->res_word != RES_IN)
7772 /* current word is FOR or IN (BOLD in comments below) */
7773 if (cpipe->next == NULL) {
7774 syntax_error("malformed for");
7776 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7779 /* "FOR v; do ..." and "for v IN a b; do..." are ok */
7780 if (cpipe->next->res_word == RES_DO)
7782 /* next word is not "do". It must be "in" then ("FOR v in ...") */
7783 if (cpipe->res_word == RES_IN /* "for v IN a b; not_do..."? */
7784 || cpipe->next->res_word != RES_IN /* FOR v not_do_and_not_in..."? */
7786 syntax_error("malformed for");
7788 debug_printf_exec("run_list lvl %d return 1\n", G.run_list_level);
7795 /* Past this point, all code paths should jump to ret: label
7796 * in order to return, no direct "return" statements please.
7797 * This helps to ensure that no memory is leaked. */
7805 last_rword = RES_XXXX;
7807 last_followup = PIPE_SEQ;
7808 rcode = G.last_exitcode;
7810 /* Go through list of pipes, (maybe) executing them. */
7811 for (; pi; pi = IF_HUSH_LOOPS(rword == RES_DONE ? loop_top : ) pi->next) {
7816 if (G_flag_return_in_progress == 1)
7819 IF_HAS_KEYWORDS(rword = pi->res_word;)
7820 debug_printf_exec(": rword=%d cond_code=%d last_rword=%d\n",
7821 rword, cond_code, last_rword);
7822 #if ENABLE_HUSH_LOOPS
7823 if ((rword == RES_WHILE || rword == RES_UNTIL || rword == RES_FOR)
7824 && loop_top == NULL /* avoid bumping G.depth_of_loop twice */
7826 /* start of a loop: remember where loop starts */
7831 /* Still in the same "if...", "then..." or "do..." branch? */
7832 if (IF_HAS_KEYWORDS(rword == last_rword &&) 1) {
7833 if ((rcode == 0 && last_followup == PIPE_OR)
7834 || (rcode != 0 && last_followup == PIPE_AND)
7836 /* It is "<true> || CMD" or "<false> && CMD"
7837 * and we should not execute CMD */
7838 debug_printf_exec("skipped cmd because of || or &&\n");
7839 last_followup = pi->followup;
7840 goto dont_check_jobs_but_continue;
7843 last_followup = pi->followup;
7844 IF_HAS_KEYWORDS(last_rword = rword;)
7847 if (rword == RES_THEN) {
7848 /* if false; then ... fi has exitcode 0! */
7849 G.last_exitcode = rcode = EXIT_SUCCESS;
7850 /* "if <false> THEN cmd": skip cmd */
7854 if (rword == RES_ELSE || rword == RES_ELIF) {
7855 /* "if <true> then ... ELSE/ELIF cmd":
7856 * skip cmd and all following ones */
7861 #if ENABLE_HUSH_LOOPS
7862 if (rword == RES_FOR) { /* && pi->num_cmds - always == 1 */
7864 /* first loop through for */
7866 static const char encoded_dollar_at[] ALIGN1 = {
7867 SPECIAL_VAR_SYMBOL, '@' | 0x80, SPECIAL_VAR_SYMBOL, '\0'
7868 }; /* encoded representation of "$@" */
7869 static const char *const encoded_dollar_at_argv[] = {
7870 encoded_dollar_at, NULL
7871 }; /* argv list with one element: "$@" */
7874 vals = (char**)encoded_dollar_at_argv;
7875 if (pi->next->res_word == RES_IN) {
7876 /* if no variable values after "in" we skip "for" */
7877 if (!pi->next->cmds[0].argv) {
7878 G.last_exitcode = rcode = EXIT_SUCCESS;
7879 debug_printf_exec(": null FOR: exitcode EXIT_SUCCESS\n");
7882 vals = pi->next->cmds[0].argv;
7883 } /* else: "for var; do..." -> assume "$@" list */
7884 /* create list of variable values */
7885 debug_print_strings("for_list made from", vals);
7886 for_list = expand_strvec_to_strvec(vals);
7887 for_lcur = for_list;
7888 debug_print_strings("for_list", for_list);
7891 /* "for" loop is over, clean up */
7897 /* Insert next value from for_lcur */
7898 /* note: *for_lcur already has quotes removed, $var expanded, etc */
7899 set_local_var(xasprintf("%s=%s", pi->cmds[0].argv[0], *for_lcur++), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ 0);
7902 if (rword == RES_IN) {
7903 continue; /* "for v IN list;..." - "in" has no cmds anyway */
7905 if (rword == RES_DONE) {
7906 continue; /* "done" has no cmds too */
7909 #if ENABLE_HUSH_CASE
7910 if (rword == RES_CASE) {
7911 debug_printf_exec("CASE cond_code:%d\n", cond_code);
7912 case_word = expand_strvec_to_string(pi->cmds->argv);
7915 if (rword == RES_MATCH) {
7918 debug_printf_exec("MATCH cond_code:%d\n", cond_code);
7919 if (!case_word) /* "case ... matched_word) ... WORD)": we executed selected branch, stop */
7921 /* all prev words didn't match, does this one match? */
7922 argv = pi->cmds->argv;
7924 char *pattern = expand_string_to_string(*argv, /*unbackslash:*/ 1);
7925 /* TODO: which FNM_xxx flags to use? */
7926 cond_code = (fnmatch(pattern, case_word, /*flags:*/ 0) != 0);
7928 if (cond_code == 0) { /* match! we will execute this branch */
7930 case_word = NULL; /* make future "word)" stop */
7937 if (rword == RES_CASE_BODY) { /* inside of a case branch */
7938 debug_printf_exec("CASE_BODY cond_code:%d\n", cond_code);
7940 continue; /* not matched yet, skip this pipe */
7942 if (rword == RES_ESAC) {
7943 debug_printf_exec("ESAC cond_code:%d\n", cond_code);
7945 /* "case" did not match anything: still set $? (to 0) */
7946 G.last_exitcode = rcode = EXIT_SUCCESS;
7950 /* Just pressing <enter> in shell should check for jobs.
7951 * OTOH, in non-interactive shell this is useless
7952 * and only leads to extra job checks */
7953 if (pi->num_cmds == 0) {
7954 if (G_interactive_fd)
7955 goto check_jobs_and_continue;
7959 /* After analyzing all keywords and conditions, we decided
7960 * to execute this pipe. NB: have to do checkjobs(NULL)
7961 * after run_pipe to collect any background children,
7962 * even if list execution is to be stopped. */
7963 debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
7964 #if ENABLE_HUSH_LOOPS
7965 G.flag_break_continue = 0;
7967 rcode = r = run_pipe(pi); /* NB: rcode is a smalluint, r is int */
7969 /* We ran a builtin, function, or group.
7970 * rcode is already known
7971 * and we don't need to wait for anything. */
7972 debug_printf_exec(": builtin/func exitcode %d\n", rcode);
7973 G.last_exitcode = rcode;
7974 check_and_run_traps();
7975 #if ENABLE_HUSH_LOOPS
7976 /* Was it "break" or "continue"? */
7977 if (G.flag_break_continue) {
7978 smallint fbc = G.flag_break_continue;
7979 /* We might fall into outer *loop*,
7980 * don't want to break it too */
7982 G.depth_break_continue--;
7983 if (G.depth_break_continue == 0)
7984 G.flag_break_continue = 0;
7985 /* else: e.g. "continue 2" should *break* once, *then* continue */
7986 } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */
7987 if (G.depth_break_continue != 0 || fbc == BC_BREAK) {
7988 checkjobs(NULL, 0 /*(no pid to wait for)*/);
7991 /* "continue": simulate end of loop */
7996 if (G_flag_return_in_progress == 1) {
7997 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8000 } else if (pi->followup == PIPE_BG) {
8001 /* What does bash do with attempts to background builtins? */
8002 /* even bash 3.2 doesn't do that well with nested bg:
8003 * try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
8004 * I'm NOT treating inner &'s as jobs */
8006 if (G.run_list_level == 1)
8009 /* Last command's pid goes to $! */
8010 G.last_bg_pid = pi->cmds[pi->num_cmds - 1].pid;
8011 debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n");
8012 /* Check pi->pi_inverted? "! sleep 1 & echo $?": bash says 1. dash and ash says 0 */
8013 rcode = EXIT_SUCCESS;
8017 if (G.run_list_level == 1 && G_interactive_fd) {
8018 /* Waits for completion, then fg's main shell */
8019 rcode = checkjobs_and_fg_shell(pi);
8020 debug_printf_exec(": checkjobs_and_fg_shell exitcode %d\n", rcode);
8024 /* This one just waits for completion */
8025 rcode = checkjobs(pi, 0 /*(no pid to wait for)*/);
8026 debug_printf_exec(": checkjobs exitcode %d\n", rcode);
8028 G.last_exitcode = rcode;
8029 check_and_run_traps();
8032 /* Analyze how result affects subsequent commands */
8034 if (rword == RES_IF || rword == RES_ELIF)
8037 check_jobs_and_continue:
8038 checkjobs(NULL, 0 /*(no pid to wait for)*/);
8039 dont_check_jobs_but_continue: ;
8040 #if ENABLE_HUSH_LOOPS
8041 /* Beware of "while false; true; do ..."! */
8043 && (pi->next->res_word == RES_DO || pi->next->res_word == RES_DONE)
8044 /* check for RES_DONE is needed for "while ...; do \n done" case */
8046 if (rword == RES_WHILE) {
8048 /* "while false; do...done" - exitcode 0 */
8049 G.last_exitcode = rcode = EXIT_SUCCESS;
8050 debug_printf_exec(": while expr is false: breaking (exitcode:EXIT_SUCCESS)\n");
8054 if (rword == RES_UNTIL) {
8056 debug_printf_exec(": until expr is true: breaking\n");
8067 #if ENABLE_HUSH_LOOPS
8072 #if ENABLE_HUSH_CASE
8076 debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
8080 /* Select which version we will use */
8081 static int run_and_free_list(struct pipe *pi)
8084 debug_printf_exec("run_and_free_list entered\n");
8085 if (!G.o_opt[OPT_O_NOEXEC]) {
8086 debug_printf_exec(": run_list: 1st pipe with %d cmds\n", pi->num_cmds);
8087 rcode = run_list(pi);
8089 /* free_pipe_list has the side effect of clearing memory.
8090 * In the long run that function can be merged with run_list,
8091 * but doing that now would hobble the debugging effort. */
8093 debug_printf_exec("run_and_free_list return %d\n", rcode);
8098 static void install_sighandlers(unsigned mask)
8100 sighandler_t old_handler;
8102 while ((mask >>= 1) != 0) {
8106 old_handler = install_sighandler(sig, pick_sighandler(sig));
8107 /* POSIX allows shell to re-enable SIGCHLD
8108 * even if it was SIG_IGN on entry.
8109 * Therefore we skip IGN check for it:
8113 if (old_handler == SIG_IGN) {
8114 /* oops... restore back to IGN, and record this fact */
8115 install_sighandler(sig, old_handler);
8117 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8119 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8124 /* Called a few times only (or even once if "sh -c") */
8125 static void install_special_sighandlers(void)
8129 /* Which signals are shell-special? */
8130 mask = (1 << SIGQUIT) | (1 << SIGCHLD);
8131 if (G_interactive_fd) {
8132 mask |= SPECIAL_INTERACTIVE_SIGS;
8133 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
8134 mask |= SPECIAL_JOBSTOP_SIGS;
8136 /* Careful, do not re-install handlers we already installed */
8137 if (G.special_sig_mask != mask) {
8138 unsigned diff = mask & ~G.special_sig_mask;
8139 G.special_sig_mask = mask;
8140 install_sighandlers(diff);
8146 /* Set handlers to restore tty pgrp and exit */
8147 static void install_fatal_sighandlers(void)
8151 /* We will restore tty pgrp on these signals */
8153 /*+ (1 << SIGILL ) * HUSH_DEBUG*/
8154 /*+ (1 << SIGFPE ) * HUSH_DEBUG*/
8155 + (1 << SIGBUS ) * HUSH_DEBUG
8156 + (1 << SIGSEGV) * HUSH_DEBUG
8157 /*+ (1 << SIGTRAP) * HUSH_DEBUG*/
8159 /* bash 3.2 seems to handle these just like 'fatal' ones */
8162 /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
8163 * if we aren't interactive... but in this case
8164 * we never want to restore pgrp on exit, and this fn is not called
8166 /*+ (1 << SIGHUP )*/
8167 /*+ (1 << SIGTERM)*/
8168 /*+ (1 << SIGINT )*/
8170 G_fatal_sig_mask = mask;
8172 install_sighandlers(mask);
8176 static int set_mode(int state, char mode, const char *o_opt)
8181 G.o_opt[OPT_O_NOEXEC] = state;
8184 IF_HUSH_MODE_X(G_x_mode = state;)
8188 /* "set -+o" without parameter.
8189 * in bash, set -o produces this output:
8193 * We always use the second form.
8195 const char *p = o_opt_strings;
8198 printf("set %co %s\n", (G.o_opt[idx] ? '-' : '+'), p);
8204 idx = index_in_strings(o_opt_strings, o_opt);
8206 G.o_opt[idx] = state;
8210 return EXIT_FAILURE;
8212 return EXIT_SUCCESS;
8215 int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8216 int hush_main(int argc, char **argv)
8219 OPT_login = (1 << 0),
8223 unsigned builtin_argc;
8225 struct variable *cur_var;
8226 struct variable *shell_ver;
8229 if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
8230 G.last_exitcode = EXIT_SUCCESS;
8232 #if ENABLE_HUSH_FAST
8233 G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
8236 G.argv0_for_re_execing = argv[0];
8238 /* Deal with HUSH_VERSION */
8239 shell_ver = xzalloc(sizeof(*shell_ver));
8240 shell_ver->flg_export = 1;
8241 shell_ver->flg_read_only = 1;
8242 /* Code which handles ${var<op>...} needs writable values for all variables,
8243 * therefore we xstrdup: */
8244 shell_ver->varstr = xstrdup(hush_version_str);
8245 /* Create shell local variables from the values
8246 * currently living in the environment */
8247 debug_printf_env("unsetenv '%s'\n", "HUSH_VERSION");
8248 unsetenv("HUSH_VERSION"); /* in case it exists in initial env */
8249 G.top_var = shell_ver;
8250 cur_var = G.top_var;
8253 char *value = strchr(*e, '=');
8254 if (value) { /* paranoia */
8255 cur_var->next = xzalloc(sizeof(*cur_var));
8256 cur_var = cur_var->next;
8257 cur_var->varstr = *e;
8258 cur_var->max_len = strlen(*e);
8259 cur_var->flg_export = 1;
8263 /* (Re)insert HUSH_VERSION into env (AFTER we scanned the env!) */
8264 debug_printf_env("putenv '%s'\n", shell_ver->varstr);
8265 putenv(shell_ver->varstr);
8268 set_pwd_var(/*exp:*/ 1);
8270 #if ENABLE_HUSH_BASH_COMPAT
8271 /* Set (but not export) HOSTNAME unless already set */
8272 if (!get_local_var_value("HOSTNAME")) {
8275 set_local_var_from_halves("HOSTNAME", uts.nodename);
8277 /* bash also exports SHLVL and _,
8278 * and sets (but doesn't export) the following variables:
8280 * BASH_VERSINFO=([0]="3" [1]="2" [2]="0" [3]="1" [4]="release" [5]="i386-pc-linux-gnu")
8281 * BASH_VERSION='3.2.0(1)-release'
8283 * MACHTYPE=i386-pc-linux-gnu
8285 * PPID=<NNNNN> - we also do it elsewhere
8296 * PIPESTATUS=([0]="0")
8297 * HISTFILE=/<xxx>/.bash_history
8301 * PATH=/usr/gnu/bin:/usr/local/bin:/bin:/usr/bin:.
8303 * SHELLOPTS=braceexpand:emacs:hashall:histexpand:history:interactive-comments:monitor
8314 #if ENABLE_FEATURE_EDITING
8315 G.line_input_state = new_line_input_t(FOR_SHELL);
8318 /* Initialize some more globals to non-zero values */
8319 cmdedit_update_prompt();
8321 die_func = restore_ttypgrp_and__exit;
8323 /* Shell is non-interactive at first. We need to call
8324 * install_special_sighandlers() if we are going to execute "sh <script>",
8325 * "sh -c <cmds>" or login shell's /etc/profile and friends.
8326 * If we later decide that we are interactive, we run install_special_sighandlers()
8327 * in order to intercept (more) signals.
8331 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
8332 flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
8335 opt = getopt(argc, argv, "+c:xinsl"
8338 # if ENABLE_HUSH_FUNCTIONS
8348 * sh ... -c 'script'
8349 * sh ... -c 'script' ARG0 [ARG1...]
8350 * On NOMMU, if builtin_argc != 0,
8351 * sh ... -c 'builtin' BARGV... "" ARG0 [ARG1...]
8352 * "" needs to be replaced with NULL
8353 * and BARGV vector fed to builtin function.
8354 * Note: the form without ARG0 never happens:
8355 * sh ... -c 'builtin' BARGV... ""
8358 G.root_pid = getpid();
8359 G.root_ppid = getppid();
8361 G.global_argv = argv + optind;
8362 G.global_argc = argc - optind;
8364 /* -c 'builtin' [BARGV...] "" ARG0 [ARG1...] */
8365 const struct built_in_command *x;
8367 install_special_sighandlers();
8368 x = find_builtin(optarg);
8369 if (x) { /* paranoia */
8370 G.global_argc -= builtin_argc; /* skip [BARGV...] "" */
8371 G.global_argv += builtin_argc;
8372 G.global_argv[-1] = NULL; /* replace "" */
8374 G.last_exitcode = x->b_function(argv + optind - 1);
8378 if (!G.global_argv[0]) {
8379 /* -c 'script' (no params): prevent empty $0 */
8380 G.global_argv--; /* points to argv[i] of 'script' */
8381 G.global_argv[0] = argv[0];
8383 } /* else -c 'script' ARG0 [ARG1...]: $0 is ARG0 */
8384 install_special_sighandlers();
8385 parse_and_run_string(optarg);
8388 /* Well, we cannot just declare interactiveness,
8389 * we have to have some stuff (ctty, etc) */
8390 /* G_interactive_fd++; */
8393 /* "-s" means "read from stdin", but this is how we always
8394 * operate, so simply do nothing here. */
8400 case '<': /* "big heredoc" support */
8401 full_write1_str(optarg);
8404 unsigned long long empty_trap_mask;
8406 G.root_pid = bb_strtou(optarg, &optarg, 16);
8408 G.root_ppid = bb_strtou(optarg, &optarg, 16);
8410 G.last_bg_pid = bb_strtou(optarg, &optarg, 16);
8412 G.last_exitcode = bb_strtou(optarg, &optarg, 16);
8414 builtin_argc = bb_strtou(optarg, &optarg, 16);
8416 empty_trap_mask = bb_strtoull(optarg, &optarg, 16);
8417 if (empty_trap_mask != 0) {
8419 install_special_sighandlers();
8420 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
8421 for (sig = 1; sig < NSIG; sig++) {
8422 if (empty_trap_mask & (1LL << sig)) {
8423 G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
8424 install_sighandler(sig, SIG_IGN);
8428 # if ENABLE_HUSH_LOOPS
8430 G.depth_of_loop = bb_strtou(optarg, &optarg, 16);
8436 set_local_var(xstrdup(optarg), /*exp:*/ 0, /*lvl:*/ 0, /*ro:*/ opt == 'R');
8438 # if ENABLE_HUSH_FUNCTIONS
8440 struct function *funcp = new_function(optarg);
8441 /* funcp->name is already set to optarg */
8442 /* funcp->body is set to NULL. It's a special case. */
8443 funcp->body_as_string = argv[optind];
8451 if (set_mode(1, opt, NULL) == 0) /* no error */
8455 fprintf(stderr, "Usage: sh [FILE]...\n"
8456 " or: sh -c command [args]...\n\n");
8462 } /* option parsing loop */
8464 /* Skip options. Try "hush -l": $1 should not be "-l"! */
8465 G.global_argc = argc - (optind - 1);
8466 G.global_argv = argv + (optind - 1);
8467 G.global_argv[0] = argv[0];
8470 G.root_pid = getpid();
8471 G.root_ppid = getppid();
8474 /* If we are login shell... */
8475 if (flags & OPT_login) {
8477 debug_printf("sourcing /etc/profile\n");
8478 input = fopen_for_read("/etc/profile");
8479 if (input != NULL) {
8480 remember_FILE(input);
8481 install_special_sighandlers();
8482 parse_and_run_file(input);
8483 fclose_and_forget(input);
8485 /* bash: after sourcing /etc/profile,
8486 * tries to source (in the given order):
8487 * ~/.bash_profile, ~/.bash_login, ~/.profile,
8488 * stopping on first found. --noprofile turns this off.
8489 * bash also sources ~/.bash_logout on exit.
8490 * If called as sh, skips .bash_XXX files.
8494 if (G.global_argv[1]) {
8497 * "bash <script>" (which is never interactive (unless -i?))
8498 * sources $BASH_ENV here (without scanning $PATH).
8499 * If called as sh, does the same but with $ENV.
8500 * Also NB, per POSIX, $ENV should undergo parameter expansion.
8504 debug_printf("running script '%s'\n", G.global_argv[0]);
8505 xfunc_error_retval = 127; /* for "hush /does/not/exist" case */
8506 input = xfopen_for_read(G.global_argv[0]);
8507 xfunc_error_retval = 1;
8508 remember_FILE(input);
8509 install_special_sighandlers();
8510 parse_and_run_file(input);
8511 #if ENABLE_FEATURE_CLEAN_UP
8512 fclose_and_forget(input);
8517 /* Up to here, shell was non-interactive. Now it may become one.
8518 * NB: don't forget to (re)run install_special_sighandlers() as needed.
8521 /* A shell is interactive if the '-i' flag was given,
8522 * or if all of the following conditions are met:
8524 * no arguments remaining or the -s flag given
8525 * standard input is a terminal
8526 * standard output is a terminal
8527 * Refer to Posix.2, the description of the 'sh' utility.
8530 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8531 G_saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
8532 debug_printf("saved_tty_pgrp:%d\n", G_saved_tty_pgrp);
8533 if (G_saved_tty_pgrp < 0)
8534 G_saved_tty_pgrp = 0;
8536 /* try to dup stdin to high fd#, >= 255 */
8537 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8538 if (G_interactive_fd < 0) {
8539 /* try to dup to any fd */
8540 G_interactive_fd = dup(STDIN_FILENO);
8541 if (G_interactive_fd < 0) {
8543 G_interactive_fd = 0;
8544 G_saved_tty_pgrp = 0;
8547 // TODO: track & disallow any attempts of user
8548 // to (inadvertently) close/redirect G_interactive_fd
8550 debug_printf("interactive_fd:%d\n", G_interactive_fd);
8551 if (G_interactive_fd) {
8552 close_on_exec_on(G_interactive_fd);
8554 if (G_saved_tty_pgrp) {
8555 /* If we were run as 'hush &', sleep until we are
8556 * in the foreground (tty pgrp == our pgrp).
8557 * If we get started under a job aware app (like bash),
8558 * make sure we are now in charge so we don't fight over
8559 * who gets the foreground */
8561 pid_t shell_pgrp = getpgrp();
8562 G_saved_tty_pgrp = tcgetpgrp(G_interactive_fd);
8563 if (G_saved_tty_pgrp == shell_pgrp)
8565 /* send TTIN to ourself (should stop us) */
8566 kill(- shell_pgrp, SIGTTIN);
8570 /* Install more signal handlers */
8571 install_special_sighandlers();
8573 if (G_saved_tty_pgrp) {
8574 /* Set other signals to restore saved_tty_pgrp */
8575 install_fatal_sighandlers();
8576 /* Put ourselves in our own process group
8577 * (bash, too, does this only if ctty is available) */
8578 bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
8579 /* Grab control of the terminal */
8580 tcsetpgrp(G_interactive_fd, getpid());
8582 enable_restore_tty_pgrp_on_exit();
8584 # if ENABLE_HUSH_SAVEHISTORY && MAX_HISTORY > 0
8586 const char *hp = get_local_var_value("HISTFILE");
8588 hp = get_local_var_value("HOME");
8590 hp = concat_path_file(hp, ".hush_history");
8595 G.line_input_state->hist_file = hp;
8596 //set_local_var(xasprintf("HISTFILE=%s", ...));
8598 # if ENABLE_FEATURE_SH_HISTFILESIZE
8599 hp = get_local_var_value("HISTFILESIZE");
8600 G.line_input_state->max_history = size_from_HISTFILESIZE(hp);
8605 install_special_sighandlers();
8607 #elif ENABLE_HUSH_INTERACTIVE
8608 /* No job control compiled in, only prompt/line editing */
8609 if (isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)) {
8610 G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
8611 if (G_interactive_fd < 0) {
8612 /* try to dup to any fd */
8613 G_interactive_fd = dup(STDIN_FILENO);
8614 if (G_interactive_fd < 0)
8616 G_interactive_fd = 0;
8619 if (G_interactive_fd) {
8620 close_on_exec_on(G_interactive_fd);
8622 install_special_sighandlers();
8624 /* We have interactiveness code disabled */
8625 install_special_sighandlers();
8628 * if interactive but not a login shell, sources ~/.bashrc
8629 * (--norc turns this off, --rcfile <file> overrides)
8632 if (!ENABLE_FEATURE_SH_EXTRA_QUIET && G_interactive_fd) {
8633 /* note: ash and hush share this string */
8634 printf("\n\n%s %s\n"
8635 IF_HUSH_HELP("Enter 'help' for a list of built-in commands.\n")
8638 "hush - the humble shell"
8642 parse_and_run_file(stdin);
8645 hush_exit(G.last_exitcode);
8650 int msh_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
8651 int msh_main(int argc, char **argv)
8653 bb_error_msg("msh is deprecated, please use hush instead");
8654 return hush_main(argc, argv);
8662 static int FAST_FUNC builtin_true(char **argv UNUSED_PARAM)
8667 static int run_applet_main(char **argv, int (*applet_main_func)(int argc, char **argv))
8674 return applet_main_func(argc, argv - argc);
8677 static int FAST_FUNC builtin_test(char **argv)
8679 return run_applet_main(argv, test_main);
8682 static int FAST_FUNC builtin_echo(char **argv)
8684 return run_applet_main(argv, echo_main);
8688 static int FAST_FUNC builtin_printf(char **argv)
8690 return run_applet_main(argv, printf_main);
8694 static char **skip_dash_dash(char **argv)
8697 if (argv[0] && argv[0][0] == '-' && argv[0][1] == '-' && argv[0][2] == '\0')
8702 static int FAST_FUNC builtin_eval(char **argv)
8704 int rcode = EXIT_SUCCESS;
8706 argv = skip_dash_dash(argv);
8708 char *str = expand_strvec_to_string(argv);
8710 * eval "echo Hi; done" ("done" is syntax error):
8711 * "echo Hi" will not execute too.
8713 parse_and_run_string(str);
8715 rcode = G.last_exitcode;
8720 static int FAST_FUNC builtin_cd(char **argv)
8724 argv = skip_dash_dash(argv);
8726 if (newdir == NULL) {
8727 /* bash does nothing (exitcode 0) if HOME is ""; if it's unset,
8728 * bash says "bash: cd: HOME not set" and does nothing
8731 const char *home = get_local_var_value("HOME");
8732 newdir = home ? home : "/";
8734 if (chdir(newdir)) {
8735 /* Mimic bash message exactly */
8736 bb_perror_msg("cd: %s", newdir);
8737 return EXIT_FAILURE;
8739 /* Read current dir (get_cwd(1) is inside) and set PWD.
8740 * Note: do not enforce exporting. If PWD was unset or unexported,
8741 * set it again, but do not export. bash does the same.
8743 set_pwd_var(/*exp:*/ 0);
8744 return EXIT_SUCCESS;
8747 static int FAST_FUNC builtin_exec(char **argv)
8749 argv = skip_dash_dash(argv);
8750 if (argv[0] == NULL)
8751 return EXIT_SUCCESS; /* bash does this */
8753 /* Careful: we can end up here after [v]fork. Do not restore
8754 * tty pgrp then, only top-level shell process does that */
8755 if (G_saved_tty_pgrp && getpid() == G.root_pid)
8756 tcsetpgrp(G_interactive_fd, G_saved_tty_pgrp);
8758 /* TODO: if exec fails, bash does NOT exit! We do.
8759 * We'll need to undo trap cleanup (it's inside execvp_or_die)
8760 * and tcsetpgrp, and this is inherently racy.
8762 execvp_or_die(argv);
8765 static int FAST_FUNC builtin_exit(char **argv)
8767 debug_printf_exec("%s()\n", __func__);
8769 /* interactive bash:
8770 * # trap "echo EEE" EXIT
8773 * There are stopped jobs.
8774 * (if there are _stopped_ jobs, running ones don't count)
8777 * EEE (then bash exits)
8779 * TODO: we can use G.exiting = -1 as indicator "last cmd was exit"
8782 /* note: EXIT trap is run by hush_exit */
8783 argv = skip_dash_dash(argv);
8784 if (argv[0] == NULL)
8785 hush_exit(G.last_exitcode);
8786 /* mimic bash: exit 123abc == exit 255 + error msg */
8787 xfunc_error_retval = 255;
8788 /* bash: exit -2 == exit 254, no error msg */
8789 hush_exit(xatoi(argv[0]) & 0xff);
8792 static void print_escaped(const char *s)
8797 const char *p = strchrnul(s, '\'');
8798 /* print 'xxxx', possibly just '' */
8799 printf("'%.*s'", (int)(p - s), s);
8804 /* s points to '; print "'''...'''" */
8806 do putchar('\''); while (*++s == '\'');
8811 #if !ENABLE_HUSH_LOCAL
8812 #define helper_export_local(argv, exp, lvl) \
8813 helper_export_local(argv, exp)
8815 static void helper_export_local(char **argv, int exp, int lvl)
8819 char *name_end = strchrnul(name, '=');
8821 /* So far we do not check that name is valid (TODO?) */
8823 if (*name_end == '\0') {
8824 struct variable *var, **vpp;
8826 vpp = get_ptr_to_local_var(name, name_end - name);
8827 var = vpp ? *vpp : NULL;
8829 if (exp == -1) { /* unexporting? */
8830 /* export -n NAME (without =VALUE) */
8832 var->flg_export = 0;
8833 debug_printf_env("%s: unsetenv '%s'\n", __func__, name);
8835 } /* else: export -n NOT_EXISTING_VAR: no-op */
8838 if (exp == 1) { /* exporting? */
8839 /* export NAME (without =VALUE) */
8841 var->flg_export = 1;
8842 debug_printf_env("%s: putenv '%s'\n", __func__, var->varstr);
8843 putenv(var->varstr);
8847 #if ENABLE_HUSH_LOCAL
8848 if (exp == 0 /* local? */
8849 && var && var->func_nest_level == lvl
8851 /* "local x=abc; ...; local x" - ignore second local decl */
8855 /* Exporting non-existing variable.
8856 * bash does not put it in environment,
8857 * but remembers that it is exported,
8858 * and does put it in env when it is set later.
8859 * We just set it to "" and export. */
8860 /* Or, it's "local NAME" (without =VALUE).
8861 * bash sets the value to "". */
8862 name = xasprintf("%s=", name);
8864 /* (Un)exporting/making local NAME=VALUE */
8865 name = xstrdup(name);
8867 set_local_var(name, /*exp:*/ exp, /*lvl:*/ lvl, /*ro:*/ 0);
8871 static int FAST_FUNC builtin_export(char **argv)
8873 unsigned opt_unexport;
8875 #if ENABLE_HUSH_EXPORT_N
8876 /* "!": do not abort on errors */
8877 opt_unexport = getopt32(argv, "!n");
8878 if (opt_unexport == (uint32_t)-1)
8879 return EXIT_FAILURE;
8886 if (argv[0] == NULL) {
8893 /* ash emits: export VAR='VAL'
8894 * bash: declare -x VAR="VAL"
8895 * we follow ash example */
8896 const char *s = *e++;
8897 const char *p = strchr(s, '=');
8899 if (!p) /* wtf? take next variable */
8902 printf("export %.*s", (int)(p - s) + 1, s);
8903 print_escaped(p + 1);
8907 /*fflush_all(); - done after each builtin anyway */
8909 return EXIT_SUCCESS;
8912 helper_export_local(argv, (opt_unexport ? -1 : 1), 0);
8914 return EXIT_SUCCESS;
8917 #if ENABLE_HUSH_LOCAL
8918 static int FAST_FUNC builtin_local(char **argv)
8920 if (G.func_nest_level == 0) {
8921 bb_error_msg("%s: not in a function", argv[0]);
8922 return EXIT_FAILURE; /* bash compat */
8924 helper_export_local(argv, 0, G.func_nest_level);
8925 return EXIT_SUCCESS;
8929 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#unset */
8930 static int FAST_FUNC builtin_unset(char **argv)
8935 /* "!": do not abort on errors */
8936 /* "+": stop at 1st non-option */
8937 opts = getopt32(argv, "!+vf");
8938 if (opts == (unsigned)-1)
8939 return EXIT_FAILURE;
8941 bb_error_msg("unset: -v and -f are exclusive");
8942 return EXIT_FAILURE;
8948 if (!(opts & 2)) { /* not -f */
8949 if (unset_local_var(*argv)) {
8950 /* unset <nonexistent_var> doesn't fail.
8951 * Error is when one tries to unset RO var.
8952 * Message was printed by unset_local_var. */
8956 #if ENABLE_HUSH_FUNCTIONS
8966 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#set
8967 * built-in 'set' handler
8969 * set [-abCefhmnuvx] [-o option] [argument...]
8970 * set [+abCefhmnuvx] [+o option] [argument...]
8971 * set -- [argument...]
8974 * Implementations shall support the options in both their hyphen and
8975 * plus-sign forms. These options can also be specified as options to sh.
8977 * Write out all variables and their values: set
8978 * Set $1, $2, and $3 and set "$#" to 3: set c a b
8979 * Turn on the -x and -v options: set -xv
8980 * Unset all positional parameters: set --
8981 * Set $1 to the value of x, even if it begins with '-' or '+': set -- "$x"
8982 * Set the positional parameters to the expansion of x, even if x expands
8983 * with a leading '-' or '+': set -- $x
8985 * So far, we only support "set -- [argument...]" and some of the short names.
8987 static int FAST_FUNC builtin_set(char **argv)
8990 char **pp, **g_argv;
8991 char *arg = *++argv;
8995 for (e = G.top_var; e; e = e->next)
8997 return EXIT_SUCCESS;
9001 if (strcmp(arg, "--") == 0) {
9005 if (arg[0] != '+' && arg[0] != '-')
9007 for (n = 1; arg[n]; ++n) {
9008 if (set_mode((arg[0] == '-'), arg[n], argv[1]))
9010 if (arg[n] == 'o' && argv[1])
9013 } while ((arg = *++argv) != NULL);
9014 /* Now argv[0] is 1st argument */
9017 return EXIT_SUCCESS;
9020 /* NB: G.global_argv[0] ($0) is never freed/changed */
9021 g_argv = G.global_argv;
9022 if (G.global_args_malloced) {
9028 G.global_args_malloced = 1;
9029 pp = xzalloc(sizeof(pp[0]) * 2);
9030 pp[0] = g_argv[0]; /* retain $0 */
9033 /* This realloc's G.global_argv */
9034 G.global_argv = pp = add_strings_to_strings(g_argv, argv, /*dup:*/ 1);
9041 return EXIT_SUCCESS;
9043 /* Nothing known, so abort */
9045 bb_error_msg("set: %s: invalid option", arg);
9046 return EXIT_FAILURE;
9049 static int FAST_FUNC builtin_shift(char **argv)
9052 argv = skip_dash_dash(argv);
9056 if (n >= 0 && n < G.global_argc) {
9057 if (G.global_args_malloced) {
9060 free(G.global_argv[m++]);
9063 memmove(&G.global_argv[1], &G.global_argv[n+1],
9064 G.global_argc * sizeof(G.global_argv[0]));
9065 return EXIT_SUCCESS;
9067 return EXIT_FAILURE;
9070 /* Interruptibility of read builtin in bash
9071 * (tested on bash-4.2.8 by sending signals (not by ^C)):
9073 * Empty trap makes read ignore corresponding signal, for any signal.
9076 * - terminates non-interactive shell;
9077 * - interrupts read in interactive shell;
9078 * if it has non-empty trap:
9079 * - executes trap and returns to command prompt in interactive shell;
9080 * - executes trap and returns to read in non-interactive shell;
9082 * - is ignored (does not interrupt) read in interactive shell;
9083 * - terminates non-interactive shell;
9084 * if it has non-empty trap:
9085 * - executes trap and returns to read;
9087 * - terminates shell (regardless of interactivity);
9088 * if it has non-empty trap:
9089 * - executes trap and returns to read;
9091 static int FAST_FUNC builtin_read(char **argv)
9101 /* "!": do not abort on errors.
9102 * Option string must start with "sr" to match BUILTIN_READ_xxx
9104 read_flags = getopt32(argv, "!srn:p:t:u:", &opt_n, &opt_p, &opt_t, &opt_u);
9105 if (read_flags == (uint32_t)-1)
9106 return EXIT_FAILURE;
9108 ifs = get_local_var_value("IFS"); /* can be NULL */
9111 r = shell_builtin_read(set_local_var_from_halves,
9121 if ((uintptr_t)r == 1 && errno == EINTR) {
9122 unsigned sig = check_and_run_traps();
9123 if (sig && sig != SIGINT)
9127 if ((uintptr_t)r > 1) {
9128 bb_error_msg("%s", r);
9129 r = (char*)(uintptr_t)1;
9132 return (uintptr_t)r;
9135 static int FAST_FUNC builtin_trap(char **argv)
9141 G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
9146 /* No args: print all trapped */
9147 for (i = 0; i < NSIG; ++i) {
9150 print_escaped(G.traps[i]);
9151 /* note: bash adds "SIG", but only if invoked
9152 * as "bash". If called as "sh", or if set -o posix,
9153 * then it prints short signal names.
9154 * We are printing short names: */
9155 printf(" %s\n", get_signame(i));
9158 /*fflush_all(); - done after each builtin anyway */
9159 return EXIT_SUCCESS;
9163 /* If first arg is a number: reset all specified signals */
9164 sig = bb_strtou(*argv, NULL, 10);
9170 sighandler_t handler;
9172 sig = get_signum(*argv++);
9173 if (sig < 0 || sig >= NSIG) {
9175 /* Mimic bash message exactly */
9176 bb_perror_msg("trap: %s: invalid signal specification", argv[-1]);
9181 G.traps[sig] = xstrdup(new_cmd);
9183 debug_printf("trap: setting SIG%s (%i) to '%s'\n",
9184 get_signame(sig), sig, G.traps[sig]);
9186 /* There is no signal for 0 (EXIT) */
9191 handler = (new_cmd[0] ? record_pending_signo : SIG_IGN);
9193 /* We are removing trap handler */
9194 handler = pick_sighandler(sig);
9195 install_sighandler(sig, handler);
9200 if (!argv[1]) { /* no second arg */
9201 bb_error_msg("trap: invalid arguments");
9202 return EXIT_FAILURE;
9205 /* First arg is "-": reset all specified to default */
9206 /* First arg is "--": skip it, the rest is "handler SIGs..." */
9207 /* Everything else: set arg as signal handler
9208 * (includes "" case, which ignores signal) */
9209 if (argv[0][0] == '-') {
9210 if (argv[0][1] == '\0') { /* "-" */
9211 /* new_cmd remains NULL: "reset these sigs" */
9214 if (argv[0][1] == '-' && argv[0][2] == '\0') { /* "--" */
9217 /* else: "-something", no special meaning */
9222 goto process_sig_list;
9225 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/type.html */
9226 static int FAST_FUNC builtin_type(char **argv)
9228 int ret = EXIT_SUCCESS;
9234 if (0) {} /* make conditional compile easier below */
9235 /*else if (find_alias(*argv))
9236 type = "an alias";*/
9237 #if ENABLE_HUSH_FUNCTIONS
9238 else if (find_function(*argv))
9239 type = "a function";
9241 else if (find_builtin(*argv))
9242 type = "a shell builtin";
9243 else if ((path = find_in_path(*argv)) != NULL)
9246 bb_error_msg("type: %s: not found", *argv);
9251 printf("%s is %s\n", *argv, type);
9259 static struct pipe *parse_jobspec(const char *str)
9264 if (sscanf(str, "%%%d", &jobnum) != 1) {
9265 bb_error_msg("bad argument '%s'", str);
9268 for (pi = G.job_list; pi; pi = pi->next) {
9269 if (pi->jobid == jobnum) {
9273 bb_error_msg("%d: no such job", jobnum);
9277 /* built-in 'fg' and 'bg' handler */
9278 static int FAST_FUNC builtin_fg_bg(char **argv)
9283 if (!G_interactive_fd)
9284 return EXIT_FAILURE;
9286 /* If they gave us no args, assume they want the last backgrounded task */
9288 for (pi = G.job_list; pi; pi = pi->next) {
9289 if (pi->jobid == G.last_jobid) {
9293 bb_error_msg("%s: no current job", argv[0]);
9294 return EXIT_FAILURE;
9297 pi = parse_jobspec(argv[1]);
9299 return EXIT_FAILURE;
9301 /* TODO: bash prints a string representation
9302 * of job being foregrounded (like "sleep 1 | cat") */
9303 if (argv[0][0] == 'f' && G_saved_tty_pgrp) {
9304 /* Put the job into the foreground. */
9305 tcsetpgrp(G_interactive_fd, pi->pgrp);
9308 /* Restart the processes in the job */
9309 debug_printf_jobs("reviving %d procs, pgrp %d\n", pi->num_cmds, pi->pgrp);
9310 for (i = 0; i < pi->num_cmds; i++) {
9311 debug_printf_jobs("reviving pid %d\n", pi->cmds[i].pid);
9313 pi->stopped_cmds = 0;
9315 i = kill(- pi->pgrp, SIGCONT);
9317 if (errno == ESRCH) {
9318 delete_finished_bg_job(pi);
9319 return EXIT_SUCCESS;
9321 bb_perror_msg("kill (SIGCONT)");
9324 if (argv[0][0] == 'f') {
9326 return checkjobs_and_fg_shell(pi);
9328 return EXIT_SUCCESS;
9332 #if ENABLE_HUSH_HELP
9333 static int FAST_FUNC builtin_help(char **argv UNUSED_PARAM)
9335 const struct built_in_command *x;
9338 "Built-in commands:\n"
9339 "------------------\n");
9340 for (x = bltins1; x != &bltins1[ARRAY_SIZE(bltins1)]; x++) {
9342 printf("%-10s%s\n", x->b_cmd, x->b_descr);
9344 return EXIT_SUCCESS;
9348 #if MAX_HISTORY && ENABLE_FEATURE_EDITING
9349 static int FAST_FUNC builtin_history(char **argv UNUSED_PARAM)
9351 show_history(G.line_input_state);
9352 return EXIT_SUCCESS;
9357 static int FAST_FUNC builtin_jobs(char **argv UNUSED_PARAM)
9360 const char *status_string;
9362 checkjobs(NULL, 0 /*(no pid to wait for)*/);
9363 for (job = G.job_list; job; job = job->next) {
9364 if (job->alive_cmds == job->stopped_cmds)
9365 status_string = "Stopped";
9367 status_string = "Running";
9369 printf(JOB_STATUS_FORMAT, job->jobid, status_string, job->cmdtext);
9371 return EXIT_SUCCESS;
9376 static int FAST_FUNC builtin_memleak(char **argv UNUSED_PARAM)
9381 # ifdef M_TRIM_THRESHOLD
9382 /* Optional. Reduces probability of false positives */
9385 /* Crude attempt to find where "free memory" starts,
9386 * sans fragmentation. */
9388 l = (unsigned long)p;
9391 if (l < (unsigned long)p) l = (unsigned long)p;
9397 struct mallinfo mi = mallinfo();
9398 printf("top alloc:0x%lx malloced:%d+%d=%d\n", l,
9399 mi.arena, mi.hblkhd, mi.arena + mi.hblkhd);
9403 if (!G.memleak_value)
9404 G.memleak_value = l;
9406 l -= G.memleak_value;
9413 /* Exitcode is "how many kilobytes we leaked since 1st call" */
9418 static int FAST_FUNC builtin_pwd(char **argv UNUSED_PARAM)
9421 return EXIT_SUCCESS;
9424 static int FAST_FUNC builtin_source(char **argv)
9426 char *arg_path, *filename;
9429 #if ENABLE_HUSH_FUNCTIONS
9433 argv = skip_dash_dash(argv);
9436 /* bash says: "bash: .: filename argument required" */
9437 return 2; /* bash compat */
9440 if (!strchr(filename, '/')) {
9441 arg_path = find_in_path(filename);
9443 filename = arg_path;
9445 input = remember_FILE(fopen_or_warn(filename, "r"));
9448 /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */
9449 /* POSIX: non-interactive shell should abort here,
9450 * not merely fail. So far no one complained :)
9452 return EXIT_FAILURE;
9455 #if ENABLE_HUSH_FUNCTIONS
9456 sv_flg = G_flag_return_in_progress;
9457 /* "we are inside sourced file, ok to use return" */
9458 G_flag_return_in_progress = -1;
9461 save_and_replace_G_args(&sv, argv);
9463 /* "false; . ./empty_line; echo Zero:$?" should print 0 */
9464 G.last_exitcode = 0;
9465 parse_and_run_file(input);
9466 fclose_and_forget(input);
9469 restore_G_args(&sv, argv);
9470 #if ENABLE_HUSH_FUNCTIONS
9471 G_flag_return_in_progress = sv_flg;
9474 return G.last_exitcode;
9477 static int FAST_FUNC builtin_umask(char **argv)
9484 argv = skip_dash_dash(argv);
9486 mode_t old_mask = mask;
9488 /* numeric umasks are taken as-is */
9489 /* symbolic umasks are inverted: "umask a=rx" calls umask(222) */
9490 if (!isdigit(argv[0][0]))
9492 mask = bb_parse_mode(argv[0], mask);
9493 if (!isdigit(argv[0][0]))
9495 if ((unsigned)mask > 0777) {
9498 * bash: umask: 'q': invalid symbolic mode operator
9499 * bash: umask: 999: octal number out of range
9501 bb_error_msg("%s: invalid mode '%s'", "umask", argv[0]);
9506 printf("%04o\n", (unsigned) mask);
9507 /* fall through and restore mask which we set to 0 */
9511 return !rc; /* rc != 0 - success */
9514 /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */
9515 #if !ENABLE_HUSH_JOB
9516 # define wait_for_child_or_signal(pipe,pid) wait_for_child_or_signal(pid)
9518 static int wait_for_child_or_signal(struct pipe *waitfor_pipe, pid_t waitfor_pid)
9525 if (!sigisemptyset(&G.pending_set))
9528 /* waitpid is not interruptible by SA_RESTARTed
9529 * signals which we use. Thus, this ugly dance:
9532 /* Make sure possible SIGCHLD is stored in kernel's
9533 * pending signal mask before we call waitpid.
9534 * Or else we may race with SIGCHLD, lose it,
9535 * and get stuck in sigsuspend...
9537 sigfillset(&oldset); /* block all signals, remember old set */
9538 sigprocmask(SIG_SETMASK, &oldset, &oldset);
9540 if (!sigisemptyset(&G.pending_set)) {
9541 /* Crap! we raced with some signal! */
9545 /*errno = 0; - checkjobs does this */
9546 /* Can't pass waitfor_pipe into checkjobs(): it won't be interruptible */
9547 ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */
9548 debug_printf_exec("checkjobs:%d\n", ret);
9551 int rcode = job_exited_or_stopped(waitfor_pipe);
9552 debug_printf_exec("job_exited_or_stopped:%d\n", rcode);
9555 sigprocmask(SIG_SETMASK, &oldset, NULL);
9560 /* if ECHILD, there are no children (ret is -1 or 0) */
9561 /* if ret == 0, no children changed state */
9562 /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */
9563 if (errno == ECHILD || ret) {
9565 if (ret < 0) /* if ECHILD, may need to fix "ret" */
9567 sigprocmask(SIG_SETMASK, &oldset, NULL);
9570 /* Wait for SIGCHLD or any other signal */
9571 /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */
9572 /* Note: sigsuspend invokes signal handler */
9573 sigsuspend(&oldset);
9575 sigprocmask(SIG_SETMASK, &oldset, NULL);
9577 /* So, did we get a signal? */
9578 sig = check_and_run_traps();
9579 if (sig /*&& sig != SIGCHLD - always true */) {
9583 /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */
9588 static int FAST_FUNC builtin_wait(char **argv)
9593 argv = skip_dash_dash(argv);
9594 if (argv[0] == NULL) {
9595 /* Don't care about wait results */
9596 /* Note 1: must wait until there are no more children */
9597 /* Note 2: must be interruptible */
9599 * $ sleep 3 & sleep 6 & wait
9604 * $ sleep 3 & sleep 6 & wait
9608 * ^C <-- after ~4 sec from keyboard
9611 return wait_for_child_or_signal(NULL, 0 /*(no job and no pid to wait for)*/);
9615 pid_t pid = bb_strtou(*argv, NULL, 10);
9616 if (errno || pid <= 0) {
9618 if (argv[0][0] == '%') {
9619 struct pipe *wait_pipe;
9620 wait_pipe = parse_jobspec(*argv);
9622 ret = job_exited_or_stopped(wait_pipe);
9624 ret = wait_for_child_or_signal(wait_pipe, 0);
9629 /* mimic bash message */
9630 bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
9632 continue; /* bash checks all argv[] */
9635 /* Do we have such child? */
9636 ret = waitpid(pid, &status, WNOHANG);
9639 if (errno == ECHILD) {
9640 if (G.last_bg_pid > 0 && pid == G.last_bg_pid) {
9641 /* "wait $!" but last bg task has already exited. Try:
9642 * (sleep 1; exit 3) & sleep 2; echo $?; wait $!; echo $?
9643 * In bash it prints exitcode 0, then 3.
9644 * In dash, it is 127.
9646 /* ret = G.last_bg_pid_exitstatus - FIXME */
9648 /* Example: "wait 1". mimic bash message */
9649 bb_error_msg("wait: pid %d is not a child of this shell", (int)pid);
9653 bb_perror_msg("wait %s", *argv);
9656 continue; /* bash checks all argv[] */
9659 /* Yes, and it still runs */
9660 ret = wait_for_child_or_signal(NULL, pid);
9662 /* Yes, and it just exited */
9663 process_wait_result(NULL, pid, status);
9664 ret = WEXITSTATUS(status);
9665 if (WIFSIGNALED(status))
9666 ret = 128 + WTERMSIG(status);
9673 #if ENABLE_HUSH_LOOPS || ENABLE_HUSH_FUNCTIONS
9674 static unsigned parse_numeric_argv1(char **argv, unsigned def, unsigned def_min)
9677 def = bb_strtou(argv[1], NULL, 10);
9678 if (errno || def < def_min || argv[2]) {
9679 bb_error_msg("%s: bad arguments", argv[0]);
9687 #if ENABLE_HUSH_LOOPS
9688 static int FAST_FUNC builtin_break(char **argv)
9691 if (G.depth_of_loop == 0) {
9692 bb_error_msg("%s: only meaningful in a loop", argv[0]);
9693 /* if we came from builtin_continue(), need to undo "= 1" */
9694 G.flag_break_continue = 0;
9695 return EXIT_SUCCESS; /* bash compat */
9697 G.flag_break_continue++; /* BC_BREAK = 1, or BC_CONTINUE = 2 */
9699 G.depth_break_continue = depth = parse_numeric_argv1(argv, 1, 1);
9700 if (depth == UINT_MAX)
9701 G.flag_break_continue = BC_BREAK;
9702 if (G.depth_of_loop < depth)
9703 G.depth_break_continue = G.depth_of_loop;
9705 return EXIT_SUCCESS;
9708 static int FAST_FUNC builtin_continue(char **argv)
9710 G.flag_break_continue = 1; /* BC_CONTINUE = 2 = 1+1 */
9711 return builtin_break(argv);
9715 #if ENABLE_HUSH_FUNCTIONS
9716 static int FAST_FUNC builtin_return(char **argv)
9720 if (G_flag_return_in_progress != -1) {
9721 bb_error_msg("%s: not in a function or sourced script", argv[0]);
9722 return EXIT_FAILURE; /* bash compat */
9725 G_flag_return_in_progress = 1;
9728 * out of range: wraps around at 256, does not error out
9729 * non-numeric param:
9730 * f() { false; return qwe; }; f; echo $?
9731 * bash: return: qwe: numeric argument required <== we do this
9732 * 255 <== we also do this
9734 rc = parse_numeric_argv1(argv, G.last_exitcode, 0);